WO2006057290A1

WO2006057290A1 - Inkjet recording medium and method for producing same

Info

Publication number: WO2006057290A1
Application number: PCT/JP2005/021567
Authority: WO
Inventors: Hiroyuki Nemoto; Nobuhisa Dano; Shinichi Asano; Tomoyuki Hisaoka
Original assignee: Oji Paper Co., Ltd.
Priority date: 2004-11-24
Filing date: 2005-11-24
Publication date: 2006-06-01
Also published as: JP2006142748A

Abstract

Disclosed is a method for producing an inkjet recording medium which is characterized by forming an ink receiving layer on a support or at least one undercoat layer formed on the support, and forming a surface layer on the ink receiving layer by applying a coating material for surface layer, which contains colloidal particles and an ink fixing agent, over the ink receiving layer. The method is further characterized in that the ink receiving layer contains at least one material selected from silica, alumina and alumina hydrates as a pigment, while further containing a binder and a crosslinking agent for the binder.

Description

Specification

Ink jet recording body and method for producing the same

Technical field

TECHNICAL FIELD [0001] The present invention relates to an ink jet recording body, and in particular, is an ink jet recording body with high glossiness and high print density suitable for photographic image output, which has excellent ink absorbability and also has pigment ink fixing properties. It relates to the record.

This application claims priority based on Japanese Patent Application No. 2004-338712 filed on November 24, 2004, the contents of which are incorporated herein by reference.

Background art

[0002] An ink jet recording method in which an aqueous ink is ejected from a fine nozzle to form an image is easy to be full-colored, capable of high-speed recording, and is less expensive than other printing apparatuses by printing a small number of copies. For some reason, it is widely used in terminal printers, facsimiles, plotters, and form printing.

[0003] In recent years, printers have been rapidly spread, and high definition and high speed have been progressing. As a result, ink jet recording media have been required to have higher ink absorption speed than ever before. Realization of high image quality comparable to silver halide photography is strongly demanded for recorded images. Further, in order to bring the quality of the printed image closer to that of a photograph, further improvement in the color density and glossiness of the printed image is desired.

[0004] On the other hand, improvement of the ink itself has been proposed in order to realize image storage stability equivalent to that of silver halide photography! Along with water-based dye inks (hereinafter referred to as dye inks) that use a highly hydrophilic and colorant that dominates conventional inks for inkjet recording, hydrophobic color pigments with excellent water resistance and light resistance are used as colorants. Ink containing ink (hereinafter referred to as pigment ink) is often used!

Colored pigments in pigment inks have been provided so far that they can easily stay on the coated surface, and in high-gloss inkjet recording media that are compatible with dye inks, the fixability and scratching properties of pigment inks are inferior. There is a strong demand for recording media that can print with high image quality for both dye and pigment ink. [0005] To achieve this, a fine pigment is used in the ink receiving layer, and the peak in the pore diameter distribution curve of the coating layer is almost 0. In other words, the roundness of the dots is controlled by controlling cracks in the coating film. Technology to achieve higher ink absorption speed and gloss while reproducing the above is essential.

[0006] For example, in JP-A-11-115308 (see Patent Document 1) and JP-A-2001-246832 (see Patent Document 2), inorganic pigment fine particles having an average primary particle diameter of 20 nm or less and a binder in an ink recording layer Inkjet recording sheets composed of polybulal alcohol have been proposed. This is high while suppressing cracking of the coating film by utilizing the cross-linking reaction between borax or boric acid and poly (bull alcohol) to cause the coating to gel before the recording layer exhibits a reduced drying rate. A coating amount can be imparted. As a result, the roundness of the dots can be reproduced, and excellent image quality can be obtained with dye inks. However, the surface gloss is improved because the surface layer of the recording sheet is formed of fine pigments and polybulal alcohol. In addition, the ink absorptivity was not sufficient for pigment inks.

In Japanese Unexamined Patent Publication No. 2001-246832 (see Patent Document 2), boric acid or a boron compound is coated on the support between the support and the ink recording layer in an amount of at least 0.1 lgZm ² per one surface of the support. The polybutyl alcohol in the recording layer is cross-linked by the boric acid or boron compound of the undercoat, and the coating gels before the recording layer exhibits a reduced drying rate, thereby causing cracks in the coating film. Suppressed. However, the surface gloss of the recording material obtained by this method was not yet satisfactory.

[0007] In addition, in Japanese Patent Application Laid-Open No. 2000-301828 (see Patent Document 3), the first porous layer is applied to a non-water-absorbing support and dried, or before the end of drying. There has been proposed an ink jet recording sheet which is coated and does not generate bubbles on the film surface. By this method, an ink recording layer free from bubbles and cracks still has insufficient gloss and ink absorption speed.

[0008] Japanese Patent Application Laid-Open No. 5-104848 (see Patent Document 4), Japanese Patent Publication No. 7-37175 (see Patent Document 5) discloses an ink jet recording paper manufacturing method using a water-absorbing base paper as a support. Are listed. Japanese Patent Application Laid-Open No. 5-104848 discloses borax or boron on the surface of a piece of paper. The force that the acid treatment layer and the ink receiving layer are sequentially provided Since wet silica having an average particle diameter of 1 m or more is used for the ink receiving layer, the gloss and the image density were not improved.

Japanese Examined Patent Publication No. 7-37175 discloses a base paper coated with borax or boric acid in an amount of at least 0.1 lgZm ² per side, and an ink receiving layer of 5 to ²⁰ gZm ² on one side of the base paper. The power for disclosing the ink jet recording material to be provided Since wet silica having an average particle diameter of 1 μm or more is also used for the ink receiving layer, high gloss and image density could not be obtained.

[0009] Japanese Patent No. 3322980 (see Patent Document 6) discloses a method for producing a fabric for an inkjet printer by boric acid or borate supported on a fabric and then applying a boehmite sol containing polybutyl alcohol. Proposed. This method involves impregnating a cotton fabric with a sodium orthoborate aqueous solution and drying it, and then applying a boehmite sol, and relates to a method for producing a fabric that can provide a high-definition image with an inkjet printer. .

[0010] In addition, as a technique for imparting gloss, JP-A-7-101142 (see Patent Document 7) contains a colloidal particle and a polymer latex on a recording layer mainly composed of a micron order pigment. There have been attempts to provide a glossy layer. In such a configuration, a certain amount of light is obtained, but since the dye in the ink is fixed on the recording layer of the micron order, the image density is low and the uniformity of the image is also poor. In addition, the peak distribution in the pore distribution curve of the glossy layer was larger than L m, that is, the glossy layer was cracked, so the visual gloss was low, and the fixability of the pigment ink was also poor.

In order to further increase the gloss, Japanese Patent Application Laid-Open No. 7-117335 (see Patent Document 8) discloses a method in which a gloss developing layer is pressed against a heated mirror drum while it is wet and the mirror surface is copied. was suggested. Although a certain level of gloss can be obtained by this method, the glossy layer has cracks, so the uniformity of the image is poor, and the problems of image density and pigment ink suitability have not been solved.

[0012] Japanese Patent Application Laid-Open No. 2001-10220 (see Patent Document 9) has an outermost layer using an aggregate pigment in which two or more recording layers are provided on a substrate and an average particle diameter is 1 μm or less. Out of the wet state Attempts were made to solve the problems such as gloss, image density, and ink absorbency by pressure bonding to a heated mirror drum and casting. However, the peak in the pore diameter distribution curve of the outermost layer is not less than 0.1 m, that is, the cracks in the outermost layer are not controlled, so the dots after printing lack roundness and the image The density was insufficient and the uniformity of the image was low. In addition, with recent high-definition and high-speed printers, the ink absorbency is insufficient, and when pigment ink is used, a large amount of colored pigment is absorbed in the cracked portion of the coating film, resulting in unevenness in the image. Was unsuitable.

[0013] Patent Document 1: JP-A-11-115308 (pages 3-6)

Patent Document 2: JP 2001-246832 A (Pages 3-6)

Patent Document 3: JP 2000-301828 (pages 5-6)

Patent Document 4: Japanese Patent Laid-Open No. 5-104848 (pages 2 to 3)

Patent Document 5: Japanese Patent Publication No. 7-37175 (Pages 2-3)

Patent Document 6: Japanese Patent No. 3322980 (Page 2)

Patent Document 7: Japanese Patent Laid-Open No. 7-101142 (pages 4 and 9 to 10)

Patent Document 8: JP-A-7-117335 (Page 4)

Patent Document 9: Japanese Patent Application Laid-Open No. 2001-10220 (3rd and 9th: L0 page)

Disclosure of the invention

Problems to be solved by the invention

[0014] The present invention solves the above problems, and provides an ink jet recording medium having good ink absorbability, capable of high-speed recording, high density suitable for output of a photograph image, and extremely good gloss. Therefore, the present invention intends to provide an ink jet recording medium for both dye and pigment ink, which can obtain the same high image quality as that of a silver salt photograph in pigment ink.

Means for solving the problem

The present invention has been made in view of the above circumstances, and a specific ink receiving layer is formed on a support or an undercoat layer formed as necessary, and a specific surface layer is formed on the ink receiving layer. It was found that this can be achieved by forming an ink fixing agent and applying the ink fixing agent mainly by a coating solution for the surface layer. [0016] (1) The present invention provides a support or at least one undercoat layer formed on the support.

In addition, silica, alumina, and alumina hydrate as pigments are formed, and an ink receiving layer containing at least one selected from binders, a binder, and a crosslinking agent for the binder is formed, and colloidal particles and an ink fixing agent are formed on the ink receiving layer. A method for producing an ink jet recording material, comprising forming a surface layer by applying a surface layer coating solution containing

[0017] (2) The method for producing an ink jet recording material according to (1), which is applied by a surface layer coating liquid of 75% by mass or more of the total ink fixing agent contained in the ink receiving layer surface of the ink jet recording material. It is.

(3) The ink fixing agent contained in the surface layer coating liquid is diallyldimethylammonium chloride polymer, diallyldimethylammonium chloride acrylamide copolymer, hydrochloride of allylamide diallylamine copolymer, The method for producing an ink jet recording material according to (1) or (2), comprising at least one selected from the group force consisting of dicyandiamide, a polyethyleneamine copolymer, and a cationic coffin having a 5-membered ring amidine structure It is.

[0018] (4) Colloidal particle force contained in the surface layer coating liquid Monodispersed colloidal pigment having an average primary particle size of 3 nm to 100 nm, alumina having an average secondary particle size of 1 μm or less, and an average secondary particle size Group force consisting of alumina hydrate of 1 μm or less, gas phase method silica having an average secondary particle size of 0.7 m or less, wet gel method silica having an average secondary particle size of 0.5 μm or less The method for producing an ink jet recording material according to any one of (1) to (3), which is one type.

(5) The method for producing an ink jet recording material according to any one of (1) to (4), wherein the colloidal particle force contained in the surface layer coating liquid is cationic colloidal silica.

(6) The surface layer is formed by pressure-bonding to a heated mirror-finished metal surface while the surface layer coating liquid is in a wet state. (1) to (5) A method for producing an ink jet recording material according to any one of the above.

[0019] (7) The method for producing an ink jet recording material according to any one of (1) to (6), wherein the support is a gas-permeable support.

(8) A coating liquid for an ink-receiving layer containing a fine pigment having an average particle size of 0.01 to 1 m and a hydrophilic binder is applied onto a support or an undercoat layer, dried, and simultaneously with the application, Yeah! In the case of tanning, before the coating liquid at the time of drying shows a decreasing rate of drying, the applied coating liquid is thickened or gelled with a crosslinking agent to form an ink receiving layer, and the ink receiving layer is reduced. Any one of (1) to (7), wherein the surface layer is formed by applying the surface layer coating liquid on the ink-receiving layer after the drying rate is exhibited. A method for producing an inkjet recording material according to 1.

[0020] (9) At least one selected from the base material, or at least one subbing layer formed on the base material, and silica, alumina, and alumina hydrate strength as a pigment, and a binder, and An ink jet recording material comprising: an ink receiving layer containing a binder crosslinking agent; and a surface layer formed on the ink receiving layer and containing colloidal particles and an ink fixing agent.

(10) The ink receiving layer further contains an ink fixing agent, and the ink fixing agent is distributed so that the concentration gradually decreases toward the support side, which is more on the surface layer side. The inkjet recording medium described in 1.

(11) The ink jet recording material according to (9) or (10), wherein the colloidal particles are gas phase method aluminate or cationic colloidal silica.

The invention's effect

[0021] The ink jet recording material produced by the method for producing an ink jet recording material of the present invention has high gloss, and is excellent in printing density and printing bleeding when recorded with dye ink, ink dot roundness, and the like. Therefore, it is possible to print a high-definition image and has excellent recording suitability for pigment inks, so that it is extremely practical.

BEST MODE FOR CARRYING OUT THE INVENTION

[0022] The first invention includes at least one selected from silica, alumina, and alumina hydrate as a pigment on the support or at least one undercoat layer formed on the support. Further, an ink receiving layer containing a binder and a crosslinking agent for the binder is formed, and a surface layer coating liquid containing colloidal particles and an ink fixing agent is applied on the ink receiving layer to form a surface layer. It is a manufacturing method of an ink jet recording body characterized by forming.

[0023] When the ink jet recording material obtained by this production method is printed with a dye-type ink jet ink, an image with a clear print color can be obtained due to high print density. it can.

The reason for this is not necessarily clear, but by applying the ink fixing agent with the surface layer coating liquid, a large amount of the ink fixing agent is present near the surface of the recording material on the ink receiving side, and from the surface side. It can be present in the layer so that its density gradually decreases in the thickness direction. When printing with dye-type ink-jet ink, most of the supplied ink dye S Surface of the ink receiving layer It seems to be held nearby. In particular, when 75% by mass or more of the total ink fixing agent on the ink receiving layer surface is applied by the surface layer treatment liquid, this effect is remarkable and more preferable.

By forming at least one selected from silica, alumina, and alumina hydrate as a pigment, and forming a binder and an ink receiving layer containing a crosslinking agent for the binder, a microporous layer is formed. The balance between ink absorption speed and ink absorption capacity is the layer structure.

Further, by applying a coating solution for the surface layer containing colloidal particles on the ink receiving layer, an effect of forming a surface layer excellent in transparency and smoothness can be obtained, and the coating surface having a high reflectance can be obtained. Seems to be able to get. By combining these effects of obtaining a highly reflective coating surface with the effect of retaining most of the ink dye near the surface of the coating layer, a high print density can be achieved and the color of the printed image is vivid. It is estimated that The ink jet recording body having such a structure is prepared by, for example, applying an ink receiving layer coating liquid containing a fine pigment having an average particle diameter of 0.01 to 1 μm and a hydrophilic binder onto a support or an undercoat layer. The ink-receiving layer is dried and then thickened or gelled with a cross-linking agent at the same time as the application or before the coating liquid at the time of drying reaches a reduced rate of drying. After the ink receptive layer has reached a reduced drying rate, a surface layer coating liquid having colloidal particles and an ink fixing agent is applied onto the ink receptive layer. It is good to form.

The obtained ink jet recording material has high gloss, print density when printed with dye ink, printing bleeding, excellent ink dot roundness, etc., and can print high-definition images. Since it has excellent recordability for ink, it is extremely useful. Furthermore, the surface layer is heated while the surface layer coating solution is in a wet state. When it is formed by press-bonding to a mirror-finished metal surface, the glossiness is particularly improved.

[0025] The constituent elements of the present invention will be exemplified below.

[0026] "Support"

The support is not particularly limited as long as it is a known sheet-like substrate that can be used for an ink jet recording material, and both a permeable support and a non-permeable support can be used.

[0027] (About air-permeable support)

Examples of the air-permeable support include high-quality paper, art paper, coated paper, cast coated paper, foil paper, craft paper, baryta paper, paperboard, impregnated paper, vapor-deposited paper, water-soluble paper, or general coated paper. Paper base materials such as acid paper used for printing etc., or coated paper base paper such as neutral paper are used as appropriate. Moreover, air-permeable rosin sheets can also be used.

[0028] Examples of the paper base material include wood pulp composed mainly of wood pulp, and optionally containing additives such as fillers and various auxiliaries.

As the wood pulp, various chemical pulps, mechanical pulps, regenerated pulps and the like can be used. These pulps can be beaten with a beater to adjust paper strength, papermaking suitability, and the like. The beating degree (freeness) of the pulp is not particularly limited, but is generally about 250 to 550 ml (CSF: JIS—P-8121). In order to improve smoothness, it is desirable to increase the beating degree. However, when recording on paper, the blurring of the paper caused by the moisture in the ink and the blurring of the recorded image are better when the refining is not advanced. There are many V ,. Therefore, the freeness is preferably about 300-500ml! /.

[0029] The filler is blended for the purpose of imparting opacity or the like, or adjusting the ink absorbability, and carbonated lucium, calcined kaolin, silica, titanium oxide, and the like can be used. In particular, calcium carbonate is preferable because it becomes a paper substrate having high whiteness and the glossiness of the ink jet recording material is enhanced. If the content (ash content) of the filler in the paper substrate is about 1 to 20% by mass, the paper strength may decrease. If the amount is too small, the air permeability of the paper base material is deteriorated, so the preferable filler content is 7 to 20% by mass. Within this range, smoothness, air permeability, and paper strength are balanced, and as a result, an ink jet recording material excellent in glossiness and image sharpness can be easily obtained.

[0030] For the paper base material, sizing agent, fixing agent, paper strength enhancer, cationizing agent, yield ratio as auxiliary agents. Additives, dyes, fluorescent brighteners and the like can be added. As the paper strength enhancer, a paper strength enhancer such as polyamide epichlorohydrin coconut resin, N bureformamide buramine copolymer or the like can be used by internal addition, coating or impregnation. In particular, polyamide 1 chlorohydrin resin has the effect of improving the dimensional stability of paper when wet.

Are preferably used.

[0031] The paper base material can be further impregnated and impregnated with starch, polyvinyl alcohol, cationic resin, etc. in the size press process of the paper machine, and the surface strength, sizing degree, etc. can be adjusted. The sizing of the material (as lOOgZm ² paper) is preferably about 1 to 200 seconds. If the sizing degree is low, it may cause operational problems such as wrinkling during coating, and if it is high, the ink absorption may be reduced, and curling and cockling after printing may be remarkable. A more preferred range of sizing is 4 to 120 seconds. The basis weight of the paper substrate is not particularly limited, but is about ²⁰ to 400 gZm ² .

[0032] As the air permeability of the air-permeable support, the Oken air permeability is preferably 10 to 350 seconds. Incidentally, by setting it to 10 seconds or more, it is possible to prevent the coating liquid from penetrating into the support or the undercoat layer formed as necessary. By setting it to 350 seconds or less, it is possible to suppress the problem that the operability is inferior when performing the pressure-bonding process using a mirror surface, which will be described later. The preferred Oken air permeability is 10 to 200 seconds, more preferably 20 to 100 seconds.

[0033] (Non-permeable support)

On the other hand, as a non-permeable support, cellophane, polyethylene, polypropylene, soft polyvinyl chloride, hard polyvinyl chloride, polyester, etc., resin coated paper (for example, polyethylene laminated paper), metal oil, metal Sheet base materials such as foil, synthetic paper, and nonwoven fabric are appropriately used. Moreover, the bonding sheet | seat which bonded the film etc. on the air-permeable support body can also be used as a non-air-permeable support body. Of these, a resin film or a resin-coated paper is preferred because it has a texture close to the image quality of a silver salt photograph.

[0034] Examples of the resin film include polyester resin, which is thermoplastic resin, polyolefin resin, nylon film, and the like. Polyester resin includes polyethylene terephthalate, polybutylene terephthalate and polycyclohexene terephthalate, etc. Examples of the polyolefin resin include polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-butyl acetate copolymer, and those having these as a main component. In addition, one or more of these thermoplastic resins can be appropriately selected and used, and other thermoplastic resins can be used by mixing polystyrene, acrylate ester copolymer, and the like.

[0035] Films formed by stretching these thermoplastic resins in the machine direction and the Z or transverse direction can also be used. In addition, a film may be formed by mixing inorganic fine powder in this thermoplastic resin, and forming a film by, for example, uniaxial stretching treatment or biaxial stretching treatment. In the present invention, a multilayer film obtained by laminating a plurality of such films is used as a support. For example, a base material layer and a paper layer on both sides or one side are provided. A layer film or a 3-5 layer film in which a surface layer is formed on at least one paper-like layer may be used. Such a paper layer made of thermoplastic resin is generally known as synthetic paper.

[0036] Examples of the resin-coated paper include paper obtained by extrusion lamination of thermoplastic resin, and examples of the thermoplastic resin include polyolefin resins such as polypropylene and polyethylene, and polyester resins. In the thermoplastic resin, pigments such as titanium dioxide and dyes, ultraviolet absorbers, dispersion aids, and acid prevention agents can be appropriately blended.

[0037] In the case of a non-permeable support, as will be described later, in the case of gloss finishing with a mirror roll, it is necessary to dry after the mirror roll force is also peeled off.

[0038] (Other support)

Depending on the method of forming the coating layer (undercoat layer, ink receiving layer, surface layer) formed thereon or the application used, the support is appropriately selected from the above exemplified supports Can be used. Of course, it is possible to form a layer for adjusting the color with a fluorescent dye, fluorescent pigment, etc. on the surface of the support, or to apply a corona treatment or the like to form an antistatic layer, an anchor layer or a noble layer. . Also, to prevent curling during printing, adjust friction, improve printer transportability, and adjust touch, texture, etc., provide a back layer containing grease and, if necessary, pigments and dyes. Can do. A backside treatment layer can also be provided for the purpose of transporting the backside layer with a printer. [0039] "Undercoat layer"

An undercoat layer can be formed on the support, if necessary. By forming the undercoat layer, it is possible to suitably adjust the ink absorbency when printing with an ink jet printer, and the printability such as print density, print bleeding, and solid uniformity tends to be improved. The undercoat layer is a layer having a function of quickly absorbing the solvent component of the ink, and preferably contains a pigment and an adhesive.

[0040] (About pigments)

Examples of pigments to be mixed in the undercoat layer include kaolin, clay, calcined clay, amorphous silica (also referred to as amorphous silica), synthetic amorphous silica, zinc oxide, aluminum oxide, titanium oxide, aluminum hydroxide, Calcium carbonate, satin white, aluminum silicate, alumina, colloidal silica, zeolite, synthetic zeolite, sepiolite, smectite, synthetic smectite, magnesium silicate, magnesium carbonate, magnesium oxide, diatomaceous earth, styrene plastic pigment, hydrated talcite, urea resin One or more of various publicly known pigments in the general coated paper manufacturing field, such as plastic pigments and benzoguanamine plastic pigments, can be used in combination. Of these, zinc oxide, titanium oxide, and plastic pigments are preferable because they can prevent yellowing of the white paper portion. Amorphous silica, alumina, and zeolite are highly ink-absorbing and are preferably included as the main component.

[0041] The average particle size of the pigment (in the case of an aggregated pigment, the aggregated particle size) is preferably about 1 to 12 m, more preferably 2 to 10 μm, and even more preferably 2 to 6 μm. By setting it to 1 μm or more, an effect of improving the ink absorption rate can be obtained, and by setting it to 12 m or less, it is possible to prevent the smoothness and gloss of the ink receiving layer from being lowered. It is also possible to use pigments having different average particle sizes in combination.

[0042] Further, for the purpose of adjusting the ink absorbency or controlling the penetration of the coating liquid to be applied onto the undercoat layer, the minor component has a small average particle size, for example, the average particle size is less than 1 μm. Can be added. Examples of such pigments include colloidal silica and alumina sol, and colloidal silica is particularly preferable.

[0043] Colloidal silica (colloidal silica (a)) blended as an accessory component is ethylenically unsaturated. It is preferably blended in combination with a polymer resin (b) obtained by polymerizing a monomer having a sum bond.

That is, the undercoat layer contains colloidal silica (a) and a polymer resin _(b) obtained by polymerizing a monomer having an ethylenically unsaturated bond, or colloidal silica (a) and It is preferable to contain a complex (c) with a polymer resin (b). This further improves the surface gloss. Furthermore, the reason is unknown, but in order to finish the recording body with a high gloss, when the surface layer is wet, it is pressed onto a heated mirror-finished metal surface, preferably pressed and dried. There is a tendency to improve the releasability of mirror surface finish metal surface force.

The reason why the gloss is exhibited more clearly is not necessarily clear, but the presence of colloidal silica (a) and polymer resin (b), or composite (c) maintains the ink absorbency of the undercoat layer while maintaining the ink absorption. This is presumed to prevent the coating liquid for forming the receiving layer from penetrating into the undercoat layer.

[0044] There are two types of colloidal silica ( _a ), alkaline type and acidic type, which can be used, but it is necessary to use them appropriately according to the physical properties such as pH of the coating solution for the undercoat layer. As the particle shape of colloidal silica, both spherical colloidal silica and non-spherical colloidal silica can be used. Non-spherical colloidal silica is colloidal silica in which spherical colloidal silica is connected in series or partially branched. Spherical colloidal silica is superior in terms of ease of glossiness, and nonspherical colloidal silica is superior in terms of ink absorbability. It is important to select one of these according to the purpose or to use a mixture of both.

The particle size of colloidal silica is preferably in the range of 4 to 200 nm, more preferably 10 to 60 nm.

The amount of colloidal silica _(a) is against the 100 parts by weight of the pigment other than the colloidal silica _(a), preferably 1 to 30 parts by weight, more preferably 1 to: be adjusted in the range of LO parts by mass.

Examples of the polymer resin (b) obtained by polymerizing a monomer having an ethylenically unsaturated bond include, for example, methyl acrylate, ethyl acetate, butyl acrylate, 2-ethyl hexyl acrylate, lauryl Atarylate, 2-hydroxyethyl arylate, glycidyla Acrylic acid esters such as tarylate, methyl methacrylate, ethyl methacrylate, 2-hydroxymethyryl methacrylate, 2-hydroxypropyl methacrylate, glycidino methacrylate, styrene , _a - methylstyrene, Bulle toluene, Atari port - tolyl, vinyl chloride, bi chloride - isopropylidene, vinyl acetate, propionate Bulle, acrylic amide, N- methylol acrylamide, ethylene, obtained by polymerizing the ethylenic monomers such as butadiene And polymers that can be used. The polymer resin (b) may be a copolymer using two or more kinds of ethylenic monomers in combination, if necessary, and may be a polymer or a substituted derivative of the copolymer. . Incidentally, examples of the substituted derivative include those obtained by carboxylation or those obtained by making the carboxyl group alkali-reactive.

The blending amount of the polymer resin (b) is preferably adjusted in the range of 1 to 20 parts by mass, more preferably 1 to 5 parts by mass with respect to 100 parts by mass of the pigment other than the colloidal silica ( _a ).

Composite (c) is a composite of colloidal silica ( _a ) and polymer resin (b), and a composite of colloidal silica ( _a ) and polymer resin (b). (I) The above-mentioned ethylenic monomer is polymerized in the presence of a silane coupling agent and colloidal silica, and a complex (c) is formed by Si—O—R bond (R: polymer component). (Π) React the polymer resin (b) modified with a silanol group, etc., if necessary, and colloidal silica ( _a ) to form a Si — O—R bond (R: polymer component) ) To give a composite (c). The glass transition point (Tg) of the polymer component (polymer resin (b)) of the composite (c) is preferably 40 ° C or higher, more preferably in the range of 50-100 ° C. When the glass transition point is 40 ° C. or higher, the ink is absorbed too quickly when the film is dried, and ink bleeding tends to be difficult to occur.

Furthermore, the reason for this is not necessarily clear, but when the glass transition point is 40 ° C or higher, in order to achieve a high gloss finish on the recording paper, it is pressed against a mirror-finished metal surface while the surface layer is wet. Preferably, when crimping and drying, the releasability of the mirror drum force tends to be improved.

The amount of the composite (c) is preferably adjusted in the range of 1 to 40 parts by mass, more preferably 1 to 15 parts by mass with respect to 100 parts by mass of the pigment other than the colloidal silica (a). The ratio (mass ratio) of the colloidal silica ( _a ) and the polymer resin (b) in the composite (c) is preferably 95: 5-50: 50, more preferably 80: 20-60. : 40.

[0047] (About adhesive)

Adhesives to be mixed in the undercoat layer include proteins such as casein, soy protein, and synthetic protein, various starches such as starch and oxidized starch, polybulur alcohol, cationic polybulal alcohol, and silyl-modified polybulal alcohol. Polybulu alcohols including polybulu alcohol, cellulose derivatives such as carboxymethylcellulose and methylcellulose, styrene butadiene copolymer, conjugation polymer latex of methyl methacrylate-butadiene copolymer, acrylic polymer latex, ethylene-vinegar Conventionally known adhesives generally used for coated paper, such as vinyl polymer latex such as vinyl acid copolymer, aqueous polyurethane resin, aqueous polyester resin, etc. are used alone or in combination. .

The aqueous polyurethane resin is also commonly called urethane emulsion, urethane latex, polyurethane latex and the like. In addition, the polyurethane resin can obtain a reaction force between the polyisocyanate compound and the active hydrogen-containing compound. It is a polymer compound containing a relatively large number of urethane bonds and urea bonds.

[0048] Although the blending ratio of the pigment and the adhesive depends on the kind thereof, it is generally adjusted in the range of 1 to L00 parts by mass of the adhesive, preferably 2 to 50 parts by mass with respect to 100 parts by mass of the pigment.

[0049] (About other undercoat layers)

In the undercoat layer, various auxiliary agents such as a dispersant, a thickener, an antifoaming agent, an antistatic agent, and an antiseptic used in the production of general coated paper are appropriately added. In addition, a fluorescent dye and a colorant can be added to the undercoat layer.

[0050] (Regarding formation of undercoat layer)

The undercoat layer can be formed by applying an undercoat layer coating solution composed of the above material onto a support and drying it. The coating solution for the undercoat layer is applied after adjusting the solid content concentration to about 5 to 50% by mass.

The coating amount of the undercoat layer coating solution is, in terms of dry mass, preferably ² to 60 gZm ² , more preferably about ² to 30 gZm ² , and further preferably about 4 to ²⁰ gZm ² . Coating amount 2gZm ^{2 or more} By setting it above, the ink absorption improvement effect can be obtained sufficiently, and excellent glossiness can be obtained when the ink receiving layer is provided, and by setting it to 60 gZm ² or less, the print density can be increased or the coating can be applied. There is a tendency that the strength of the layer is improved, and powder falls and scratches are attached.

[0051] For coating of the undercoat layer coating liquid, a blade coater, an air knife coater, a roll coater

~ "Data '~", blanking Chico ¹ ~ "data'~", champlex ^co-1 ~ ~ data '~ "Bruno ¹ to" ^co-1 to "data'~", 1J Ppuko ¹ ~ "data '~", Various publicly known coating devices such as a gravure coater, curtain coater, slot die coater, and slide coater can be used.

Further, after forming the undercoat layer, a smoothing treatment such as super calendering or brushing can be further performed as necessary. The undercoat layer may be formed in two or more layers.

[Ink-Receptive Layer]

The ink receiving layer is a layer formed for the purpose of absorbing and fixing a dye or a solvent component in the ink that cannot pass through the surface layer and cannot be absorbed. For this reason, a balance between the ink absorption speed and the ink absorption capacity is required. Further, in order to increase the glossiness of the surface layer, the ink receiving layer is required to have smoothness and film formability. However, excessive film formation impairs ink absorbability.

The ink receiving layer of the present invention is an ink receiving layer containing at least one selected from silica, alumina, and alumina hydrate as a pigment, and further containing a binder and a crosslinking agent for the binder.

Preferably, such a layer is formed by applying and drying an ink-receiving layer coating solution containing a pigment and a hydrophilic binder, and at the same time as or after applying the coating layer. Before the ink-receiving layer becomes a reduced rate drying part (indicating a reduced rate drying rate), it is thickened or gelled by a crosslinking agent (for example, the coating liquid is thickened or gelled by a crosslinking agent such as a boron compound). A method of forming them can be exemplified. In this method, by thickening or gelling the paint in the early stage of drying, the coating layer can be prevented from cracking due to hot air during drying, and a great effect of preventing the paint from penetrating into the support can be obtained.

[0054] (About pigment)

Examples of pigments used in the ink receiving layer include silica, alumina, and alumina hydrate. Use at least one selected. Among these, it is preferable to use a fine pigment having an average particle size of lOnm or more and ΙΟΟΟηm or less, preferably 700 nm or less. When the average particle size is larger than lOOOnm, the transparency of the ink receiving layer is lowered, and the color development property of the colorant fixed in the ink receiving layer is lowered during ink jet recording, and a desired print density cannot be obtained. Occurs. Further, by setting the average particle diameter to 1 Onm or more, it is possible to suppress the tendency that the ink absorbability is lowered, bleeding or the like occurs, and a desired image quality cannot be obtained.

[0055] The average particle diameter of primary particles constituting the fine pigment is preferably 3 nm or more and 40 nm or less. More preferably, they are 5 nm or more and 30 nm or less, More preferably, they are 7 nm or more and 20 nm or less. If the average primary particle size is smaller than 3 nm, the voids between the primary particles are remarkably reduced, the ability to absorb the solvent and colorant in the ink is lowered, and the desired image quality tends not to be obtained. On the other hand, if the average primary particle diameter is larger than 40 nm, the aggregated secondary particles become large, the transparency of the ink receiving layer is lowered, and the color developability of the colorant fixed on the ink receiving layer during ink jet recording is reduced. There is a tendency that the desired print density cannot be obtained.

[0056] Fine pigments having an average particle size of lOOOnm or less can be obtained by, for example, mechanical strength, force, a so-called breaking down method (a method of subdividing a bulk material). The mechanical means include ultrasonic homogenizer, pressure homogenizer, liquid collision homogenizer, high-speed rotary mill, roller mill, container drive medium mill, medium agitation mill, jet mill, mortar, disintegrator (bowl-shaped A device for grinding and kneading the material to be ground in a container with a bowl-shaped stir bar), a sand grinder, and the like. In order to reduce the particle size, classification and repeated pulverization can be performed.

[0057] The average particle diameter in the present invention is determined by adjusting 200 g of an aqueous dispersion of 3% pigment, which is a powder or slurry, and then stirring and dispersing for 30 minutes with a commercially available homomixer. After that, the particle size was observed immediately with an electron microscope (SEM and TEM) (taken by an electron microscope at a magnification of 10,000 to 400,000 times, and measured and averaged the diameter of a 5 cm square particle. "See Asakura Shoten, p52, 1991).

[0058] The fine pigments include, in particular, gas phase method silica, mesoporous silica, colloidal material of wet method silica produced by condensing active key acid, alumina oxide, and alumina hydrate. It is preferable to use at least one selected from these. Of these, gas phase method silica and aluminate are preferably selected. Of the aluminate, gas phase process (fumed) aluminate is preferred.

[0059] The vapor phase silica preferably used is also referred to as fumed silica, and is generally produced by a flame hydrolysis method. Specifically, a method in which silicon tetrachloride is burned with hydrogen and oxygen is generally known. Instead of silicon tetrachloride, silicon silanes such as methyltrichlorosilane and trichlorosilane can be used alone or as tetrasalt. It can be used in a state mixed with silicon.

[0060] Mesoporous silica is a silica porous material having an average pore diameter of 1.5 to: LOOnm.

In addition, mesoporous silica into which aluminum, titanium, vanadium, boron, manganese atoms or the like are introduced can also be used. The physical properties of the porous material are not particularly limited, but the BET specific surface area (nitrogen adsorption specific surface area) is preferably 200 to 1500 m ² Zg, and the pore volume is preferably 0.5 to 4 ml Zg. The method for synthesizing mesoporous silica is not particularly limited, but is described in U.S. Pat. No. 3556725, using alkoxide of silica as a silica source and quaternary ammonium salt containing long-chain alkyl as a template. Method, quaternary ammonium salt or phosphonium salt having a long-chain alkyl group using amorphous silica powder or alkali silicate aqueous solution described in JP-A-5-503499 as a silica source A hydrothermal synthesis method using a template as described in JP-A-4-238810

V, a method of synthesizing a layered silicate such as kanemite as a silica source, an ion exchange method using a long-chain alkyl ammonium cation as a template, an amine such as dodecylamine, hexadecylamine, and a non-ionic surface activity And a method of synthesizing using active silica obtained by ion-exchange of water glass or the like as a silica source using an agent or the like as a template. A method of removing the template from the nanoporous silica precursor is a method of baking at a high temperature.

And extraction with an organic solvent.

[0061] The wet-processed silica colloid produced by condensing active caustic acid refers to the addition of an alkali to a colloidally dispersed silica seed solution, and then the active silicic acid aqueous solution and alkoxysilane are added to the seed solution. A secondary silica dispersion obtained by growing a silica fine particle by adding a feed solution having at least one kind of selected force little by little. It can be obtained by the method described in Japanese Patent No. 354408.

[0062] The aluminate is generally referred to as crystallized acid-alumina. Specific examples include acid cyanoremina having,,, 3, 0, 7 ?, _{/ 0} , pseudo, and α crystals. In the present invention, glossiness, ink absorptive power, vapor-phase method aluminate, and aluminate having γ, δ, and 0 crystals are preferably selected. Vapor phase alumina oxide (fumed alumina), which has a sharp particle size distribution and particularly excellent film formability, is most preferred.

[0063] The vapor phase method alumina oxide is alumina formed by high-temperature hydrolysis of gaseous aluminum trichloride, and as a result, high-purity alumina particles are formed. The primary particle size of these particles is nano-order and shows a very narrow particle size distribution (size distribution). Powerful vapor process aluminate oxide has a cationic surface charge. The use of vapor phase aluminate in ink jet coating is shown, for example, in US Pat. No. 5,171,626.

[0064] The alumina hydrate is not particularly limited, but boehmite or pseudoboehmite is preferably selected from the viewpoint of ink absorption rate and film formability. Alumina hydrate can be produced by, for example, hydrolyzing aluminum isopropoxide with water (BE Yoldas, Amer. Ceram. Soc. Bull., 54, 289 (1975), etc.) A method (Japanese Patent Laid-Open No. 06-064918).

[0065] (About adhesive)

The hydrophilic binder (adhesive) contained in the ink-receiving layer is a water-soluble material that thickens or gels at the same time as or after application of the ink-receiving layer coating liquid among known binders for inkjet recording. Any binder or water-dispersible binder can be used.

[0066] For example, in the case of thickening or gelling in combination with a crosslinking agent, a binder that causes a crosslinking reaction with the crosslinking agent is selectively used. Typical examples of binders that undergo a crosslinking reaction with a boron compound having a high crosslinking rate include polybulu alcohol, cation-modified polybutyl alcohol, silyl-modified polyvinyl alcohol, polyvinyl acetal, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, Casein, soy protein, synthetic proteins, starch, polypropylene oxide, polyethylene glycol, polybulle ether, Examples include polybutacrylamide, polybutylpyrrolidone, styrene monobutadiene copolymer, methyl methacrylate, and styrene monoacetate copolymer. Of these, polybulal alcohol is particularly preferably selected from the adhesive strength to pigments. Among these, the balance between the film-forming property and the ink absorptivity Polyvinyl alcohol having a polymerization degree of 2000 or more is more preferable than the polyvinylinoleo renore power having a polymerization degree of 3600-5000. In addition, two or more binders (for example, water-soluble resin and water-soluble resin, water-soluble resin and latex, etc.) may be used in combination in order to improve ink absorbability.

[0067] The blending ratio of the pigment and the binder is a force depending on the type thereof. Generally, the binder is adjusted in a range of 5 to L00 parts by mass, preferably 10 to 50 parts by mass with respect to 100 parts by mass of the pigment. When the blending ratio of the binder is less than 5 parts by mass, the coating film tends to crack, and when it exceeds 100 parts by mass, the ink absorption tends to be impaired.

[0068] (About crosslinking agent)

As the cross-linking agent, in addition to materials known as binder cross-linking agents, various known gelling agents for gelling noinders can also be used. For example, as a compound having a crosslinking property to polybulal alcohol, an aldehyde-based crosslinking agent such as darioxal, an epoxy-based crosslinking agent such as ethylene glycol diglycidyl ether, and a bur-based crosslinking agent such as bis-vinylsulfol methyl ether. Boron-containing compounds such as boric acid and borax

Examples thereof include glycidyl compounds, zirconium compounds, aluminum compounds, chromium compounds, etc. Among them, boron-containing compounds are particularly preferable because thickening or gelling occurs quickly.

[0069] The boron-containing compound is an oxyacid having a boron atom as a central atom and a salt thereof. Examples include orthoboric acid, metaboric acid, hypoboric acid, tetraboric acid, pentaboric acid and their sodium, potassium, and ammonium salts. Among these, orthoboric acid and disodium tetraborate are preferably used because they have an effect of moderately thickening the paint.

The content of the boron compound is preferably 0.01-2. Og / m ^{2 on} one side of the base material, although it depends on the degree of polymerization of the boron compound and polybulal alcohol. 2. If it is higher than Og / m ² , the crosslink density with the hydrophilic binder increases, and the coating film becomes hard and easily breaks. Become. On the other hand, if it is less than 0. OlgZm ^2, the gel of the paint that weakly crosslinks with the hydrophilic binder is weakened and the coating film tends to crack.

[0070] (Ink fixing agent)

In addition, an ink fixing agent may be added to the ink-receiving layer coating liquid for the purpose of improving the water resistance of the printed portion. The ink fixing agent is a component that fixes the colorant (dye and Z or colored pigment) component in the ink, and is used as necessary to improve the color development and storage stability of printing.

[0071] Examples of the ink fixing agent include various known cationic compounds. Specific examples thereof include (1) polyalkylene polyamines such as polyethylene polyamine and polypropylene polyamine or derivatives thereof, and (2) acrylic polymers having secondary or tertiary amino groups or quaternary ammonium groups. Copolymers of these acrylamides, (3) polybulamines and polybulamidines, (4) dicyandiamide-formalin copolymers represented by dicyanic cationic compounds, (5) dicyandiamide-polyethyleneamine copolymers Polyamine-based cationic compounds represented by polymers, (6) epichlorohydrin-dimethylamine copolymer, (7) diaryldimethylammonium SO polycondensate, (8) diarylamine Salt SO heavy

2 2 Condensate, (9) Diallyldimethylammonium chloride polymer, (10) Diallyldimethylammonium chloride acrylamide copolymer, (11) Copolymer of allylamine salt, (12) Dialkylaminoethyl (Meth) Atalylate quaternary salt copolymer, (13) Acrylamide-dialylamine copolymer, (14) Cationic resin having 5-membered ring amidine structure, (15) Dimethylaminopropyl acrylamide polymer, etc. Is mentioned. These can be used alone or in combination.

[0072] Among them, diallyldimethylammonium chloride polymer, diallyldimethylammonium chloride acrylamide copolymer, hydrochloric acid salt of acrylamide diallylamine copolymer, dicyandiamide-polyethyleneamine copolymer, and 5-membered ring amidine It is preferable to use at least one selected from the group consisting of a cationic rosin having a structure, since it is excellent in color developability and produces excellent printing with little bleeding and no color unevenness.

In the present invention, as will be described later, since the surface fixing force is applied to the support by the surface layer coating liquid so that the concentration is lowered, the ink receiving layer coating liquid is applied in advance. Arranged The ink fixing agent to be combined is preferably less than 25% by mass of the ink fixing agent in the total ink receiving layer. It should be noted that different ink fixing agents may be used as the ink fixing agent blended in advance and the ink fixing agent blended into the surface layer coating liquid.

[0074] Since silica that is suitably used as a pigment generally exhibits ionic properties, an aggregate may be formed when a cationic ink fixing agent is blended in the ink-receiving layer coating liquid. This is particularly noticeable with fine silica. In this case, at least a part of the ink fixing agent is added to and dispersed in commercially available amorphous silica (having a relatively large secondary particle size of several meters) and then pulverized or refined. It is preferable to take a procedure such as adding and mixing an ink fixing agent to the silica secondary particle dispersion, agglomerating, and then pulverizing again. As a result, the formation of aggregates having a large particle size can be suppressed, and the pigment can be adjusted to a desired particle size. The pigment thus treated has a characteristic that it is stabilized by exhibiting a structure in which the ink fixing agent is partially bonded, or is difficult to aggregate even if an ink fixing agent is further added.

[0075] Hereinafter, the pigment to be obtained is referred to as a cationic composite fine pigment. As the pigment used for the cationic composite fine pigment, a strong silica having an aluminosilicate or the like in addition to silica, particularly a gas phase method silica is preferable.

[0076] A mixture or aggregate of the pigment and the ink fixing agent may be dispersed! To grind, the homogenizer, pressure homogenizer, ultrasonic homogenizer, microfluidizer, optimizer, nanomizer 1. High-speed rotating mills, roller mills, container drive medium mills, medium stirring mills, jet mills, sand grinders, CLEARMIX, etc. are used.

[0077] When the average secondary particle size of the cationic composite fine pigment exceeds lOOOnm, it can be sufficiently dispersed by processing with a weak mechanical force such as a homomixer, but to grind the average secondary particle size to less than lOOOnm. It is effective to apply a stronger mechanical force, and it is preferable to use a pressure type dispersion method.

In the present invention, the pressure-type dispersion method is a method in which a slurry mixture of raw material particles is continuously passed through an orifice at a high pressure and pulverized at a high pressure, and the treatment pressure is from 19.6 × 10 ^{6 to} 343. 2 X 10 ⁶ Pa (200 to 3500 kgfZcm ² ), more preferably 49.0 X 10 ^{6 to} 245.3 3 X 10 ⁶ Pa (500 to 2500 kgf / cm ² ), more preferably 98.1 X 10 ^{6 to} 196 2 X 10 ⁶ Pa (l 000-2000 kgfZcm ² ). Good dispersion or pulverization can be achieved by the above high-pressure pulverization. Further, it is more preferable to use a dispersion or pulverization method in which the slurry-like mixture that has passed through the orifice at high pressure collides with each other. In the method of opposing collision, the dispersion is pressurized and guided to the inlet side, the dispersion is branched into two passages, and the flow path is further narrowed by an orifice to accelerate the flow velocity and cause the particles to collide with each other. Collide and crush. As a material constituting the portion where the dispersion is accelerated or collided, diamond is preferably used for reasons such as suppressing wear of the material.

[0079] As the high-pressure pulverizer, a pressure homogenizer, an ultrasonic homogenizer, a microfluidizer, and a nanomizer are used, and a microfluidizer and a nanomizer are particularly preferable as a high-speed flow collision type homogenizer.

The cationic composite fine pigment treated in this manner is generally obtained as an aqueous dispersion (slurry or colloidal particles) having a solid content concentration of about 5 to 20% by mass.

[0080] The mass ratio of the pigment and the ink fixing agent in the cationic composite fine pigment is not particularly limited, but the ink fixing agent is 1 to 30 parts by mass, particularly 3 to 20 parts by mass with respect to 100 parts by mass of the pigment. It is preferable that In addition, the ratio of the cationic composite fine pigment in the total pigment constituting the ink receiving layer is preferably 50% by mass or more because the transparency of the ink receiving layer is excellent.

[0081] (Other ink receiving layer)

Various additives such as dispersants, thickeners, antifoaming agents, antistatic agents, preservatives, fluorescent whitening agents, and coloring agents used in the production of general coated papers are used in the ink receiving layer coating liquid. Can be added. In addition, a preservation improving material as described later in the section of the surface layer coating solution can be added to the ink receiving layer coating solution, and it is preferable.

[0082] The ink receiving layer coating liquid is generally adjusted to a solid content concentration of about 5 to 50 mass%. The preferred solids concentration is 5-20% by weight. By setting the solid content concentration to 5% or more, the drying rate of the ink receiving layer is improved. Further, by setting it to 20% by mass or less, it becomes easy to set the moisture of the coating layer before the treatment with the surface layer coating liquid to 12% by mass or more which is a preferable moisture described later. The coating amount is not particularly limited, but is absolutely dry mass, preferably ² to 15 gZm ² , more preferably 2 to: L0 gZm ² , and further preferably 3 to 8 gZm ² . By setting the coating amount to ² gZm ² or more, excellent gloss and ink absorbency can be obtained, and by setting the coating amount to 15 g / m ² or less, cracking of the ink receiving layer is suppressed, and dot perfect circles during ink jet printing are suppressed. Good properties and the like.

[0083] As a method for applying the ink receiving layer coating liquid on a support or an undercoat layer provided as necessary, a blade coater, an air knife coater, a ronor coater, a brush coater, a champs can be used. Various publicly known coating devices such as Cusco coater, Nor coater, Lip coater, Gravure coater, Curtain coater, Slot die coater, Slide coater and Spray can be used. Of these, air knife coaters, lip coaters, slide coaters, curtain coaters, and slot die coaters are preferably used. When these coating apparatuses are used, the coating layer can be formed with a uniform thickness that is not easily affected by minute irregularities of the support or the undercoat layer, and thus the glossiness tends to be improved.

[0084] As the treatment liquid, water, an organic solvent or the like is used, and water is preferably used from the viewpoint of ease of use. It is preferable to add an ink fixing agent or a preservability improving agent to the treatment liquid, since the components penetrate into the support or the undercoat layer, and an effect of improving water resistance and heat and moisture bleeding is seen. In addition, auxiliary agents such as cross-linking agents such as boron compounds and zirconium compounds, pH adjusters, surfactants, antifoaming agents, and preservatives may be added. In addition, in order to delay the drying at the time of casting and obtain an ink-receiving layer having good printability, it is possible to add or use an organic solvent.

[0085] (Drying of coating liquid coating layer)

The thickened or gelled coating liquid coating layer is then dried to form an ink receiving layer. The drying method is not particularly limited, and a publicly known dryer such as a hot air dryer or an infrared heater can be preferably used. The drying conditions (moisture) are not particularly limited. After the surface layer coating liquid is applied, the coating liquid coating layer is further dried, so that the coating liquid coating layer can be dried even in a semi-dry state. I do not care.

[0086] When finishing the surface layer described later with a heated mirror roll, the moisture content of the L coating liquid coating layer varies depending on the support.

When the support is a gas-permeable support, the water content of the coating liquid coating layer should be 40% by mass or less. And force S, preferably 12 to 40% by mass. By setting the water content to 40% by mass or less, the amount of water evaporation on the heated mirror-finished metal surface is large, so that coating defects such as pinholes are likely to occur on the coated surface, resulting in a decrease in gloss. The tendency to be easy can be suppressed. Also, by applying the surface layer coating liquid in a state where the coating liquid coating layer (ink receiving layer) has a water content of 12% by mass or more, the surface layer coating power S penetrates into the ink receiving layer. This prevents power and gloss.

[0087] On the other hand, when a non-permeable support (for example, a resin-coated paper) is used as the support, the water content of the coating liquid coating layer is preferably 12% by mass or less. In the case of exceeding 12% by mass, when the surface layer coating liquid is applied, when the heated mirror surface roll is pressed, there is no escape space for moisture evaporated from the coating liquid coating layer (ink receiving layer). Vapor builds up between the support and the mirror roll, making it impossible to achieve sufficient pressure contact, and gloss tends not to be obtained.

[0088] The moisture is measured, for example, using an infrared moisture meter KJT-100 (manufactured by Kett Science Laboratory). Note that the apparatus is not limited to the above as long as an apparatus capable of measuring according to the same principle is used.

The measurement principle is that when the light of the absorption wavelength of water in the near infrared region (1.2 / ζ πι, 1.45 / ζ πι, 1.94 / zm) is applied to the coating layer, the water content in the coating layer Light is absorbed accordingly. The moisture value can also be calculated for the attenuation force. However, this measurement with only the absorption wavelength makes it difficult to perform stable measurement due to the influence of the surface condition and color of the substance.Therefore, a near infrared ray (reference wavelength) that is not easily affected by water is set separately. By alternately applying, the moisture value is calculated from the ratio of the energy of the reflected light of both wavelengths.

The moisture meter is installed on the coater just before the surface layer coating solution is applied. However, if there is a paper roll on the side of the coated paper opposite to the measurement surface (back side), an error may occur in the measured value, so it is better to measure the paper in the air.

[0089] "About the surface layer"

The surface layer is formed by applying a surface layer coating solution containing colloidal particles and an ink fixing agent on the ink receiving layer. Furthermore, you may mix | blend an adhesive agent as needed. The surface layer enhances the surface gloss and quickly fixes the dye or pigment in the ink. Is a coating layer for obtaining a uniform image. In particular, it is preferable that the surface layer is formed by gloss finishing by pressing the surface layer coating solution in a wet state after coating or by pressing the surface layer coating solution at the same time as the coating of the surface layer coating solution.

[0090] (Ink fixing agent)

As the ink fixing agent, known compounds blended in the ink jet recording body for the purpose of fixing the colorant (dye or coloring pigment) component in the ink for ink jet recording can be used, and are not particularly limited. An example is a cationic polymer compound. For example, a cationic polymer compound having a primary to tertiary amino group or a quaternary ammonium base as the cationic group is preferably used.

[0091] The constitution of the polymer compound includes a homopolymer of monomers having primary to tertiary amino groups or quaternary ammonium bases, monomers having these cationic groups, Examples thereof include a monomer copolymer that does not have a cationic group, or a hydrochloride, sulfate, nitrate, acetate, organic acid salt, etc., in which the counter ion of the basic group is substituted. For example, 1) polyalkylene polyamines such as polyethylene polyamine and polypropylene polyamine or derivatives thereof, 2) acryl polymers having secondary amino groups, tertiary amino groups and quaternary ammonium groups, 3) polybulamines and Polyburamidines, 4) dicyandiamide-cationic compounds represented by dicyandiamide-formalin copolymers, ₅ ) polyamine-based cationic compounds represented by dicyandiamide-polyethyleneamine copolymers, 6 ) Epichlorohydrin-dimethylamine copolymer, 7) Diaryldimethylammonium-SO polycondensation

2), 8) diallylamine salt-SO polycondensate, 9) diallyldimethylammonium chloride

2

Polymer, 10) diallyldimethylammonium chloride acrylamide copolymer, 11) copolymer of allylamine salt, 12) dialkylaminoethyl (meth) acrylate, quaternary salt copolymer, 13) acrylamide-diallylamine copolymer 14) Cationic compounds such as a cationic resin having a 5-membered ring amidine structure. These can be used alone or in combination.

[0092] Among them, diallyldimethylammonium chloride polymer, diallyldimethylammonium chloride acrylamide copolymer, hydrochloric acid salt of acrylamide diallylamine copolymer, dicyandiamide-polyethyleneamine copolymer and 5-membered ring amidine structure Have It is preferable to use at least one selected from the group consisting of cationic resins because the printing density is high, uniform color generation with less blurring is obtained, and a clear and high-definition image is obtained. . These polymer compounds are preferably used in combination with water-soluble polymers and water-soluble latex particles.

[0093] The molecular weight of the cationic polymer compound is preferably 2000 to 400,000 force S. By setting the molecular weight to 2000 or more, the glossiness when casted tends to be improved. Also, by setting it to 400000 or less, the surface layer coating liquid becomes soaked, and the tendency of the water resistance of the printed portion to decrease can be suppressed.

On the other hand, a low molecular weight cationic compound can also be used as the ink fixing agent. Examples of low molecular weight cationic compounds include cationic surfactants having 12 or more carbon atoms and water-soluble polyvalent metal salts. Examples of the cationic surfactant include quaternary ammonium salts such as halogenated alkyltrimethyl ammonium and halogenated alkyl pyridinium. As the water-soluble polyvalent metal salt, aluminum sulfate, zinc sulfate, magnesium chloride, magnesium nitrate, miyoban, etc. can be used. In addition, polysalt-aluminum, which is a compound containing a polyvalent metal, can also be used for this purpose.

[0095] These cationic compounds are used alone or in combination. In particular, when a cationic polymer compound is used in combination with a small amount of a low molecular weight cationic compound, a large amount of a cationic compound exists near the surface of the recording material on the ink receiving side. Then, the surface layer coating liquid can be easily penetrated so as to exist in the recording body so that the concentration gradually decreases in the direction toward the support, which is preferable.

[0096] The ink fixing agent can be blended in the undercoat layer coating solution and the ink receiving layer coating solution. Force All inks contained in the entire surface to be printed (undercoat layer, ink receiving layer and surface layer) It is preferable that 75% by mass or more of the fixing agent is applied by the surface layer coating liquid because the printing density increases.

[0097] (About colloidal particles)

As the colloidal particles contained in the surface layer, for example, colloidal particles of fine pigment exemplified in the ink receiving layer can be used, such as colloidal silica, specifically, gas phase method silica, mesoporous silica, active key. Wet silica colloids produced by condensation of acids At least one selected from the group of materials, colloidal silica, alumina oxide, and alumina hydrate. Among these, colloidal silica, gas phase method silica, and aluminate are preferable because excellent glaze can be obtained.

[0098] The form of the colloidal particles may be a monodisperse or an aggregated particle dispersion! However, in order to obtain a high print density and high gloss on the surface layer, the monodisperse or Among the aggregated particle dispersions, those having a small particle diameter are preferably used. In the case of a monodisperse (for example, colloidal silica), the average primary particle size is 3 to 10 to 80 nm, where LOOnm is preferred. In the case of an agglomerated particle dispersion, a fine pigment having an average primary particle size of 3 to 70 nm, preferably 5 to 40 nm, and an average (secondary) particle size of lOOOnm or less, preferably 700 nm or less, more preferably 500 nm or less is preferred. When a monodisperse pigment is used, a true spherical pigment is preferable.

[0099] In particular, in the present invention, a cationic fine pigment is preferred because the surface layer coating solution contains an ink fixing agent. In particular, gas phase method alumina oxide and cationic colloidal silica are preferably used. When using ergonal silica or the like as a pigment, the silica ink fixing agent aggregate particles obtained by mixing and aggregating silica and the ink fixing agent exemplified in the ink receiving layer are average particles. Cationic composite fine pigments pulverized in the diameter range can be used, and are preferably used.

[0100] The blending amount of the ink fixing agent and the colloidal particles is about 1 to 500 parts by mass, preferably 5 to 200 parts by mass, more preferably 10 to: 100 parts by mass of the colloidal particles. LOO Adjusted within the mass range. By setting the blending amount to 1 part by mass or more, it becomes easy to apply 75% by mass or more of the total ink fixing agent contained in the ink jet recording material. By setting the amount to 500 parts by mass or less, it is possible to suppress the tendency that the coating amount becomes too large and the voids in the ink receiving layer are blocked, resulting in poor ink absorbability.

[0101] (Formation of surface layer)

When colloidal silica is used as the colloidal particles, the surface layer coating liquid can be applied without containing an adhesive, but usually colloidal particles and an adhesive are blended. As the adhesive, known adhesives used in ink jet recording materials can be used. For example, polybulu alcohol, cation-modified polybutyl alcohol, silyl-modified polyvinyl Polybutyl alcohols such as alcohol, casein, soy protein, synthetic proteins, starch, cellulose derivatives such as carboxymethyl cellulose and methyl cellulose, butyl acetate polymer emulsion, styrene butadiene copolymer emulsion, ethylene butyl acetate Polymer emulsion, acrylic copolymer emulsion, styrene acrylic copolymer emulsion, water-based acrylic resin, water-based polyurethane resin, water-based polyester resin, and other various adhesives conventionally known in the field of coated paper Can be used alone or in combination. In the present invention, since the ink fixing agent is blended in the surface layer coating liquid, the adhesive is particularly preferably cationically modified.

[0102] When applying a gloss finish with a heated mirror roll after applying the surface layer, the glass transition temperature of the adhesive used is preferably 20 ° C or higher, more preferably 40 ° C or higher. More preferably, it is 60 ° C or higher. By setting the temperature to 20 ° C or higher, it is possible to suppress the tendency of the ink absorbability of the ink jet printer to be easily deteriorated. In addition, in order to achieve a high gloss finish on the ink jet recording material, it is pressed against a heated mirror-finished metal surface while the surface layer is in a wet state, preferably from the mirror-finished metal surface when pressed and dried. Releasability is likely to decrease and the tendency can be suppressed. Although there is no particular upper limit to the glass transition temperature, it is generally preferably 150 ° C or lower. If the temperature exceeds 150 ° C, the surface layer becomes brittle, so there may be a lot of dust when cutting, or the surface layer may be broken and the trouble due to insufficient strength may occur.

[0103] Combining two or more adhesives with different glass transition temperatures is often effective depending on the properties required. The reason for this is not clear, but since the adhesive with a low glass transition temperature and a high adhesive are not evenly mixed, the sea Z island structure is also formed, making the characteristics of each adhesive more effective. This is presumed to be exhibited. When two or more adhesives are combined, preferably at least one of them is a resin having a glass transition point of 20 ° C or higher.

[0104] The composition ratio (solid content mass ratio) between the adhesive and the colloidal particles in the surface layer coating liquid is preferably 100 parts by mass or less of the adhesive with respect to 100 parts by mass of the colloidal particles. More preferably, it is the range of 2-50 mass parts, More preferably, it is the range of 5-40 mass parts. By setting the ratio of the adhesive to 100 parts by mass or less, it is possible to suppress the tendency for the ink absorbency to decrease. wear.

[0105] In addition, a storage stability improving agent can be mixed with the surface layer coating liquid in order to improve the storage stability of the recorded image. Examples of the preservability improver include water-soluble polyvalent metal salts such as aluminum compounds such as polyaluminum salt aluminum, zirconium compounds such as zirconium carbonate ammonium and zirconium acetate, and bis [2- (2-hydroxyl). Compounds containing thiol) ethyl] sulfone, 2- (phenolthio) ethanol and the like, UV absorbers such as benzotriazole, and antioxidants such as vitamin C, vitamin E, dibutylhydroxytoluene and rutin can be incorporated. Of these, bis [2- (2-hydroxyethylthio) ethyl] sulfone is preferred because it improves the light resistance of an image printed with an ink jet printer. These preservability improvers can be blended in a coating solution for an undercoat layer, a coating solution for an ink receiving layer, and the like, but it is preferable to contain them in a coating solution for a surface layer because it is most effective.

[0106] Further, in the surface layer coating solution, in order to adjust the whiteness, viscosity, fluidity, etc., pigments, antifoaming agents, Various auxiliary agents such as a coloring agent, a fluorescent brightening agent, an antistatic agent, an antiseptic and a dispersing agent, and a thickening agent are appropriately added.

[0107] For coating of the surface layer coating liquid, a blade coater, an air knife coater, a roll coater

- Purashiko 'data, Chang flex co ¹ data -.. Roh ¹ ~ co ¹ ~ data ~ -.. Ritsufuko ^ data, Krabi aquo one coater, a curtain coater, a slot die coater, a slide coater, and various publicly known and used in the spray A coating device can be used. Of these, air knife coaters, lip coaters, slide coaters, curtain coaters, and slot die coaters are preferably used. When these coating devices are used, the coating layer can be formed with a uniform thickness that is less susceptible to the slight unevenness of the support, the undercoat layer, and the ink receiving layer. is there.

[0108] Further, it is preferable to apply the ink receiving layer and dry the surface layer with one apparatus, and then apply the surface layer. If this method is used, it is not necessary to wind up the sheet coated with the ink receiving layer, so the state of the ink receiving layer due to the pressure difference between the part close to the core and the part close to the surface when winding up. Since the change can be prevented, a uniform ink receiving layer and surface layer can be formed in the production flow direction. [0109] The surface layer coating solution is preferably applied with a solid content concentration adjusted to about 2 to 50% by mass.

The coating amount of the surface layer, 0. l~10g / m ² range is preferred instrument 0. 2-5 g / m ² and more preferred signaling 0. 5~3g / m ² is more preferred. By setting the coating amount to 0.1 lg / m ² or more, it is possible to suppress the tendency of the coating film to become thin and cause interference colors due to light. In addition, by setting the coating amount to 1OgZm ^{2 or} less, it is possible to suppress the tendency of the ink absorption rate to decrease.

[0110] (About mirror finish)

Further, in the present invention, in order to finish the glossy ink jet recording material, the gloss is obtained by a so-called cast method in which a heated mirror-finished metal surface (for example, a mirror roll) is pressed and dried while the surface layer is in a wet state. It is particularly preferable that the best glossiness can be obtained. For this, a known casting method such as a wet casting method, a rewetting casting method, a gelation casting method, or a precasting method can be employed. In particular, at the top of the mirror roll and press roll, a coating pool for the surface layer coating liquid is formed between the ink receiving layer surface and the mirror roll, and the surface layer is applied and heated while it is in a wet state. A coating method in which a metal surface having a mirror-finished surface is bonded is particularly preferable because it has a great effect on improving gloss.

[0111] Further, since it is dried on a mirror-finished metal surface (mirror roll), it may be pressed (two-ply) on the mirror-finished metal surface (mirror roll), then peeled off, and dried in a subsequent process. Absent. The drying method for the post-process is not particularly limited, and various conventionally known heating drying methods such as hot air drying, gas heater drying, high-frequency drying, electric heater drying, infrared heater drying, laser drying, and electron beam drying are appropriately used. used. Of these, hot air drying power S is advantageous because it is advantageous in terms of cost.

[0112] This method is suitable when a non-permeable support (for example, a resin-coated paper) is used as the support. In the normal casting method, the wet paint is brought into contact with the mirror roll and dried in the contacted state, so that moisture in the paint becomes vapor and escapes to the back surface. However, in the case of a non-permeable support, the generated vapor will be present between the support and the mirror roll without escape. At this time, the vapor that has lost its escape during contact with the mirror roll may lift the support and destroy the weakest part of the coating layer (ink-receiving layer, surface layer, undercoat layer). Alternatively, a heated mirror surface with a mirror finish When the adhesion of the paint to the screen is weak, it peels off at the interface between the coating layer and the mirror surface roll, and the mirror surface of the mirror surface mirror cannot be copied sufficiently, resulting in a phenomenon of so-called poor adhesion. Alternatively, if the undried coating layer is weaker than the adhesion between the mirror surface roll and the paint, it will break inside the coating layer, so a part of the coating layer remains on the surface of the mirror surface roll, and the mirror surface roll It will cause dirt.

In either case, it is impossible to form a beautiful cast surface, resulting in quality and operational problems. In the present invention, when a non-permeable support such as a resin-coated paper or a plastic film is used, it is preferable that the film is peeled after being pressed against a mirror surface roll and dried in a subsequent step.

[0113] Even in the case of using a gas-permeable support, if the surface layer is insufficiently dried after being pressure-bonded to the mirror surface roll, it may be dried in a subsequent step, or when the surface layer is pressure-bonded and dried. In addition, drying can be assisted by infrared rays or the like from the back side. Further, in order to correct the curl of the obtained ink jet recording material, a humidity control area may be provided after drying.

[0114] The surface temperature of a metal surface such as a mirror roll is preferably 80 to 120 ° C. If the surface temperature of the metal surface is less than 80 ° C, the drying effect may be poor and the productivity may decrease.If the surface temperature exceeds 120 ° C, the surface layer coating liquid will bump onto the metal surface, resulting in glossiness. And printability may be reduced.

[0115] In addition, in order to finish the recording body with a high gloss, when the surface layer is in a wet state, it is pressure-bonded to a heated mirror-finished metal surface (mirror roll), preferably pressure-bonded and dried. In the surface layer coating solution, it is preferable to add a release agent to the surface layer coating solution for the purpose of imparting a releasability with a mirror-finished metal surface equal force. It is also possible to apply a release agent to the mirror roll in advance.

[0116] As the mold release agent, higher fatty acid amides such as stearic acid amide and oleic acid amide, polyolefin waxes such as polyethylene wax, oxidized polyethylene wax, and polypropylene wax, calcium stearate, zinc stearate, potassium oleate, Examples include higher fatty acid alkali salts such as oleic acid, silicone compounds such as lecithin, silicone oil and silicone wax, and fluorine compounds such as polytetrafluoroethylene. It is. Of these, the use of a cationic release agent is particularly preferred.

Example

[0117] Hereinafter, the present invention will be described more specifically with reference to examples. However, the scope of the present invention is of course not limited thereto. In the examples, “parts” and “%” represent “parts by mass” and “mass%”, respectively, unless otherwise specified.

[0118] · Fabrication of support

(Preparation of support A (air-permeable support))

Wood pulp (LBKP: freeness 440mlCSF) 100 parts, filler (calcium carbonate 3: talc 1 ratio) 15 parts, commercial sizing agent (trade name: Huai Blanc 81K, manufactured by Nippon SC Co., Ltd.) 0.05 parts, sulfuric acid Using a papermaking material consisting of 0.45 parts of a band, 0.45 parts of starch, and 0.4 parts of polyamide-epoxyhydrin resin as a paper strength enhancer and a little yield improver. After obtaining a paper substrate having an amount of 188 gZm ² , a supercalender treatment was performed at a linear pressure of 150 kgZcm to obtain a paper substrate.

The resulting paper substrate has a thickness of 210 m, an air permeability of 30 seconds, and does not contain an ink fixing agent.

[0119] (Preparation of support B (non-permeable support))

The following polyolefin resin composition 1, which was subjected to corona discharge treatment on both sides of the above support A and then mixed and dispersed with a Banbury mixer, was applied to the felt side of support A so that the coating amount was 25 gZm2. Further, the polyolefin resin composition 2 was applied to the wire side of the support A with a melt extruder (melting temperature: 320 ° C.) having a T die so that the coating amount was 20 gZm ^2, and the felt surface was applied. The substrate was cooled and solidified with a cooling roll having a mirror surface and a cooling roll having a rough surface on the wire surface side to obtain a resin-coated support.

[0120] "Polyolefin resin composition 1"

Long chain type low density polyethylene resin (density 0.926 gZcm ³ , melt index 20 gZ 10 minutes) 35 parts, low density polyethylene resin (density 0.919 gZcm ³ , melt index 2 gZlO content) 50 parts, anatase type titanium dioxide ( Product name: A-220, manufactured by Ishihara Sangyo Co., Ltd.) 15 parts, zinc stearate 0.1 part, antioxidant (trade name: Irganox 1010, manufactured by Ciba Gaigi Co., Ltd.) 0.03 part, ultramarine (trade name: Blue (Russia Blue NO. 2000, manufactured by Daiichi Kasei Co., Ltd.) (Product name: UVITEX OB, manufactured by Ciba Gaigi Co., Ltd.) 0.3 part of the mixture was melt-mixed to obtain a polyolefin resin composition 1.

[0121] "Polyolefin resin composition 2"

High density polyethylene榭脂(density 0. 954gZcm ^3, melt index 20gZlO min) 65 parts, low density polyethylene榭脂(density 0. 919gZcm ^3, melt index 2gZlO min) 35 parts of melted and mixed, polyolefin榭脂composition 2 It was.

[0122] · Preparation of coating solution for each layer

(Preparation of coating solution for undercoat layer)

Undercoat layer coating solutions A to C having the following compositions and characteristics were prepared.

"Preparation of coating solution A for the undercoat layer (does not contain ink fixing agent!)"

Synthetic amorphous silica (trade name: Fineseal X-45, manufactured by Tokuyama Co., Ltd., average secondary particle size: 4.5 μη 100 parts, silyl-modified polybulal alcohol (trade name: R1130, manufactured by Kuraray Co., Ltd.) 2 5 parts , 2 parts of fluorescent dye (trade name: WhitexBPS (H), manufactured by Sumitomo Chemical Co., Ltd.) and water were mixed to prepare a solid concentration of 15%.

[0123] "Preparation of undercoat layer coating solution B (containing ink fixing agent)"

Synthetic amorphous silica (trade name: Fineseal X-45, manufactured by Tokuyama Co., Ltd., average secondary particle size: 4.5 μη 100 parts, silyl-modified polybulal alcohol (trade name: R1130, manufactured by Kuraray Co., Ltd.) 2 5 parts , Fluorescent dye (Product name: WhitexBPS (H), manufactured by Sumitomo Chemical Co., Ltd.) 2 parts, Cationic compound having a 5-membered ring amidine structure as an ink fixing agent (Product name: Himax SC-700M, NO And 3 parts of water (made by Imo Co., Ltd.) and water were mixed to prepare a solid content concentration of 15%, and the content of the ink fixing agent was 2.3% by mass of the total solid content.

[0124] "Preparation of coating liquid C for undercoat layer (containing ink fixing agent)"

Synthetic amorphous silica (trade name: Fineseal X-45, manufactured by Tokuyama Co., Ltd., average secondary particle size: 4.5 μη 100 parts, silyl-modified polybulal alcohol (trade name: R1130, manufactured by Kuraray Co., Ltd.) 2 5 parts , Fluorescent dye (trade name: WhitexBPS (H), manufactured by Sumitomo Chemical Co., Ltd.) 2 parts, diallyldimethylammonium chloride-acrylamide copolymer (trade name: PAS-J-81, Nittobo Spinning Co., Ltd.) 5 parts by water) and water were blended to prepare a solid content concentration of 15% The content of the ink fixing agent was 3.8% by mass of the total solid content. [0125] "Preparation of coating liquid D for undercoat layer (containing ink fixing agent)"

Synthetic amorphous silica (trade name: Fineseal X-45, manufactured by Tokuyama Co., Ltd., average secondary particle size: 4.5 μη 100 parts, silyl-modified polybulal alcohol (trade name: R1130, manufactured by Kuraray Co., Ltd.) 2 5 parts , Fluorescent dye (Product name: WhitexBPS (H), manufactured by Sumitomo Chemical Co., Ltd.) 2 parts, Diallyldimethylammonium chloride polymer power as an ink fixing agent (Product name: Nucens CP (102, manufactured by Senriki Co., Ltd.) and 5 parts of water were added to prepare a solid content concentration of 15%, and the content of the ink fixing agent was 3.8% by mass of the total solid content.

[0126] (Preparation of fine pigment)

Fine pigments A to F having the following compositions and characteristics were prepared.

"Preparation of fine pigment A"

Vapor phase silica (trade name: Aerosil A300, manufactured by Nippon Aerosil Co., Ltd., average primary particle: about 0.008 m) with an average particle size of 1.0 μm was dispersed with a homomixer, and the average particle size was The mixture was pulverized and dispersed with a high-speed collision type homogenizer until 0.15 / zm to prepare a 10% fine silica aqueous dispersion.

[0127] "Preparation of fine pigment B"

Vapor phase silica (trade name: Aerosil A300, manufactured by Nippon Aerosil Co., Ltd., average primary particle: about 0.008 m) with an average particle size of 1.0 μm was dispersed with a homomixer, and the average particle size was A 10% aqueous dispersion was prepared by pulverizing and dispersing with a high-speed collision type homogenizer until 0.08 m.

To 100 parts of the dispersion, 10 parts of a cationic compound having a 5-membered ring amidine structure (trade name: Himax SC-700M, manufactured by Hymo Co., Ltd.) as an ink fixing agent is added to aggregate the pigment. And the dispersion was further thickened, and further dispersed again with a high-speed collision type homogenizer to prepare a 10% cationic composite fine pigment aqueous dispersion with an average particle size of 0.15 μm. The content of the ink fixing agent was 9.1% by mass of the total solid content.

[0128] "Preparation of fine pigment C"

Using high-purity alumina with an average particle size of about 3.0 m (manufactured by Sumitomo Chemical Co., Ltd., trade name: AKP-G015, γ crystalline alumina, average primary particle size: about 0 .: m), homo After being dispersed by a mixer, it is further dispersed by a high-speed collision type homogenizer, and the average particle size is 0. The pulverization and dispersion operation was repeated with a liquid collision type homogenizer until a 10% alumina aqueous dispersion was prepared.

[0129] "Preparation of fine pigment D"

Using high-purity alumina with an average particle size of about 3.0 m (manufactured by Sumitomo Chemical Co., Ltd., trade name: AKP-G015, γ crystalline alumina, average primary particle size: about 0 .: m), homo After dispersing with a mixer, further disperse with a high-speed collision type homogenizer, and repeat the pulverization and dispersion operation with a liquid collision type homogenizer until the average particle size becomes 0.4 μηι. Prepared.

[0130] "Preparation of fine pigment cocoons"

Alumina hydrate with an average particle size of about 5 μm (catalyst chemicals, product name: AS-3) was dispersed with a homomixer, and then further dispersed with a high-speed collision type homogenizer. The average particle size was The pulverization and dispersion operation was repeated with a liquid collision type homogenizer until the thickness became 0.5 m to prepare a 10% fine alumina aqueous dispersion.

[0131] "Preparation of fine pigment F"

Repeated crushing and dispersion using commercially available gas phase silica (trade name: Leo Mouth Seal QS-30, primary particle size 0.009 ^ m, specific surface area 300 m ² / g, manufactured by Tokuyama Co.), averaged after classification A 10% silica dispersion with secondary particles of 0.008 μm was prepared.

To 100 parts of the dispersion, 10 parts of diaryldimethylammonium chloride-acrylamide copolymer (trade name: PAS-J-81, manufactured by Nitto Boseki Co., Ltd.) as an ink fixing agent was added. A silica dispersion was prepared in the same manner as in the preparation, and a 10% cationic composite fine pigment aqueous dispersion with an average particle size of 0.Ιδμηι was prepared. The content of the ink fixing agent was 9.1% by mass of the total solid content.

[0132] (Preparation of coating solution for ink receiving layer)

Ink-receiving layer coating liquids Α to Ε having the following compositions and characteristics were prepared.

"Preparation of coating liquid for ink-receiving layer"

100 parts of the above-mentioned fine pigment A (fine silica), polybull alcohol as a binder (product name: PVA-235, polymerization degree 3500, saponification degree 88.5%) 18 parts, dispersant (manufactured by Toa Gosei Co., Ltd.) , Product name: Aallon SD— 10) Prepare 0.05 part mixed water dispersion (concentration: 15%). Made.

[0133] "Preparation of coating solution B for ink receiving layer"

100 parts of the above-mentioned fine pigment B (cationic composite fine pigment), 18 parts of polyvinyl alcohol as a binder (made by KURARENE, trade name: PVA-235, polymerization degree 3500, Kenya degree 88.5%), dispersant (Toagosei) Product name: ALON SD-10), 0.05 part of a mixed water dispersion (concentration: 15%) was prepared. The content of the ink fixing agent was 7.7% by mass of the total solid content.

[Preparation of coating liquid C for ink receiving layer]

100 parts fine pigment C (fine alumina), polyvinyl alcohol as a binder (trade name: PVA-235, polymerization degree 3500, saponification degree 88.5%) 18 parts, dispersant (manufactured by Toa Gosei Co., Ltd.) Product name: AALON SD—10) 0.05 part of a mixed water dispersion (concentration: 15%) was prepared.

[0135] "Preparation of ink receiving layer coating solution D"

100 parts of the fine pigment D (fine alumina), polyvinyl alcohol as a binder (trade name: PVA-235, polymerization degree 3500, saponification degree 88.5%) 18 parts, dispersant (manufactured by Toa Gosei Co., Ltd.) Product name: AALON SD—10) 0.05 part of a mixed water dispersion (concentration: 15%) was prepared.

[Preparation of coating liquid E for ink receiving layer]

100 parts of the above fine pigment E (alumina hydrate), polybulal alcohol as a binder (manufactured by KURARENE, trade name: PVA-235, polymerization degree 3500, saponification degree 88.5%) 18 parts, dispersant (manufactured by Toa Gosei Co., Ltd.) , Trade name: Aaron SD-10) 0.05 parts of a mixed water dispersion (concentration: 15%) was prepared.

[0137] (Preparation of surface layer coating solution)

Surface layer coating liquids A to D having the following compositions and characteristics were prepared.

"Preparation of surface layer coating liquid A (does not contain ink fixing agent!)"

Anon colloidal silica with an average particle size of 0.05 μm (trade name: Snowtex OL, manufactured by Nissan Chemical Industries, Ltd.) 100 parts (colloidal particles), release agent (polyethylene wax, nonionic) 1 part. Solid concentration 15%. Ink fixing agent (cationic compound) is not included. [Preparation of surface layer coating solution B (containing ink fixing agent)]

Cationic colloidal silica with an average particle size of 0.03 μm (trade name: Snowtex AK—L, manufactured by Nissan Chemical Industries, Ltd.) 100 parts (colloidal particles), 5-membered ring amidin structure as an ink fixing agent Cationic compound (trade name: Himax SC-700M, manufactured by Hymo Co., Ltd.) 40 parts (ink fixing agent), release agent (polyethylene wax, non-ionic) 1 part. Solid concentration 15%. The content of the ink fixing agent was 28.4% by mass of the total solid content.

[0139] "Preparation of surface layer coating solution C (containing ink fixing agent)"

Said fine pigment F100 parts (colloidal particles), cationic compound which also has acrylamide-diarylamine copolymer power as an ink fixing agent (trade name: Sumirez resin 1001, manufactured by Sumitomo Chemical Co., Ltd.) 40 parts, release agent (Polyethylene wax, non-ionic) 1 part. Solid concentration 15%. The content of the ink fixing agent was 28.4% by mass of the total solid content.

[0140] "Preparation of surface layer coating liquid D (containing ink fixing agent)"

High-purity alumina with an average particle size of about 3.0 m (manufactured by Sumitomo Chemical Co., Ltd., trade name: AKP-G015, γ crystalline alumina, average primary particle size: about 0 .: L m) 100 parts by mass As an ink fixing agent, a cationic compound having a five-membered ring amidine structure (trade name: Himax SC-700 M, manufactured by NOMIMO Co., Ltd.), 40 parts, a release agent (polyethylene wax, NO- On) 1 part. Solid content 15%. The content of the ink fixing agent was 28.4% by mass of the total solid content.

[0141] Example 1

On the support A, the undercoat layer coating solution A (containing no ink fixing agent) was applied with an air knife coater so that the dry weight was 6 gZm ² and dried to form an undercoat layer. .

A 3% by weight aqueous borax solution was applied onto the undercoat layer so that the dry coating amount was 1.5 gZm ^2, and it was not dried. Then, the ink receiving layer coating solution A (containing an ink fixing agent) was used. No) was applied with a die coater so that the dry mass was 4 gZm ² and dried.

Subsequently, the surface layer coating liquid B (containing an ink fixing agent) was applied onto the ink receiving layer, and immediately pressed onto a mirror drum having a surface temperature of 100 ° C. and dried to obtain an ink jet recording material. The absolutely dry mass of the applied surface layer coating solution was ² gZm ² . The ink fixing agent was contained only in the surface layer coating solution. [0142] Example 2

An ink jet recording material was obtained in the same manner as in Example 1 except that the undercoat layer coating solution B (containing an ink fixing agent) was used. The absolutely dry mass of the applied surface layer coating solution was 2 g / m ² . The ink fixing agent was contained in the undercoat layer coating solution and the surface layer coating solution, and the contents were 20% and 80%, respectively.

[0143] Example 3

An ink jet recording material was obtained in the same manner as in Example 1 except that the undercoat layer coating liquid C (containing the ink fixing agent) was used. Absolute dry weight of the coated surface layer coating solution 2. OgZm ² der ivy. The ink fixing agent was contained in the coating solution for the undercoat layer and the coating solution for the surface layer, and the contents were 30% and 70%, respectively.

[0144] Example 4

An ink jet recording material was obtained in the same manner as in Example 1 except that the undercoat layer coating solution D (containing an ink fixing agent) was used. Absolute dry weight of the coated surface layer coating solution 2. OgZm ² der ivy. The ink fixing agent was contained in the coating solution for the undercoat layer and the coating solution for the surface layer, and the contents were 30% and 70%, respectively.

[0145] Example 5

An ink jet recording material was obtained in the same manner as in Example 1 except that the surface layer coating solution C (containing the ink fixing agent) was used. The absolutely dry mass of the applied surface layer coating solution was ² gZm ² . The ink fixing agent was contained only in the surface layer coating solution.

[0146] Example 6

Using the support B, the undercoat layer coating liquid A (not containing an ink fixing agent) was coated with an air knife coater so that the dry mass was 6 gZm ² and dried to form an undercoat layer. .

Subsequently, the surface layer coating liquid C (containing an ink fixing agent) is applied onto the ink receiving layer, immediately pressed against a mirror drum having a surface temperature of 100 ° C., and the drum force is also peeled off and dried to finish. A jet recording body was obtained. The absolutely dry mass of the applied surface layer coating solution was ² gZm ² . The force thionic compound was contained only in the surface layer coating solution.

[0147] Comparative Example 1

An ink jet recording material was obtained in the same manner as in Example 1, except that the ink receiving layer coating solution B (containing an ink fixing agent) and the surface layer coating solution A (containing no ink fixing agent) were used. It was. Absolute dry weight of the coated surface layer coating liquid was 0. lgZm ^2. The ink fixing agent was contained only in the ink receiving layer coating solution.

[0148] Comparative Example 2

An ink jet recording material was obtained in the same manner as in Example 1 except that the surface layer coating solution A (containing no ink fixing agent) was used. The absolute dry mass of the applied surface layer coating solution was 0. lgZ m ² . No ink fixing agent was contained.

[0149] Comparative Example 3

An ink jet recording material was obtained in the same manner as in Example 1 except that the surface layer coating solution D (containing an ink fixing agent) was used. Absolute dry weight of the coated surface layer coating liquid is 0. lgZm ² der ivy. The strength of the ink fixing agent contained only in the surface layer coating solution The pigment used is about 3.0 m of alumina, not colloidal particles! /.

[0150] Comparative Example 4

On the paper base A, the undercoat layer coating liquid A (not containing an ink fixing agent) is applied with an air knife coater so that the dry weight is 6 gZm ² and dried to form an undercoat layer. It was.

On the undercoat layer and the ink receiving layer coating solution A (containing no ink fixing agent) was coated with a die coater so that 4GZm ² absolute dry mass. Subsequently, the surface layer coating liquid B (containing an ink fixing agent) was applied to the coating layer, and immediately pressed onto a mirror drum having a surface temperature of 100 ° C. and dried to obtain an ink jet recording material. The absolutely dry mass of the applied surface layer coating solution was 0.6 gZm ² . The ink fixing agent was contained only in the surface layer coating solution.

[0151] Example 7

An ink jet recording material was obtained in the same manner as in Example 1 except that the ink receiving layer coating liquid C (containing no ink fixing agent) was used. The absolute dry mass of the applied surface layer coating solution is 0.1 It was gZm ^2. The ink fixing agent was contained only in the ink receiving layer coating solution.

[0152] Example 8

An ink jet recording material was obtained in the same manner as in Example 1 except that the ink receiving layer coating liquid D was used. The absolutely dry mass of the applied surface layer coating solution was 0.5 gZm ² . The ink fixing agent was contained only in the surface layer coating solution.

[0153] Example 9

An ink jet recording was obtained in the same manner as in Example 1 except that the ink receiving layer coating solution E was used. Absolute dry weight of the coated surface layer coating solution was 3. OgZm ^2. The ink fixing agent was contained only in the surface layer coating solution.

[0154] (Evaluation method and evaluation criteria)

The ink jet recording materials obtained in the above Examples and Comparative Examples were evaluated for glossiness and printability in ink jet recording according to the following criteria. The results are shown in Table 1. Table 1 also shows the content of each ink fixing agent in the undercoat layer coating solution, the ink receiving layer coating solution, and the surface layer coating solution of each inkjet recording body, the presence or absence of a crosslinking agent, The pigment particle size of the surface layer is also shown.

[0155] "Measurement of moisture"

The moisture content of the ink receiving layer was measured using an infrared moisture meter KJT-100 (manufactured by Kett Science Laboratory).

[0156] "Glossiness"

The glossiness and smoothness were visually evaluated from the lateral direction with respect to the surface of the ink jet recording medium.

A: Extremely high and glossy.

○: High gloss.

Δ: Glossy.

X: Glossiness is slightly inferior.

X X: Matte without gloss.

[0157] "Inkjet recording characteristics"

• Printer for evaluation Printer A: Commercially available dye ink type ink jet printer (trade name: PM—G800, manufactured by Seiko Epson Corporation)

Printer B: Commercially available pigment ink type ink jet printer (trade name: PX-G900, manufactured by Seiko Epson Corporation)

[0158] · Print density

Black solid printing was performed using printer A (dye ink type), and the print density was measured with a Macbeth reflection densitometer (Macbeth RD-914).

[0159] · Print blur

Using printer A (dye ink type), print with black, cyan, magenta, yellow, red, green, and blue solid colors arranged in a grid so as to touch each other. The ink bleeding at the boundary between them was visually evaluated.

There is no blurring of printing at all and is an excellent level.

◯: Slight bleeding is observed, but there is no practical problem.

Δ: Slightly blurring of printing and slightly problematic in practical use.

X: Level at which printing blurs become a serious problem in practical use.

[0160], Ink dot roundness

Using printer A (dye ink type), the ink density is low and no-tone printing is performed so that the ink droplets do not overlap, and the halftone printing area is magnified 200 times with an optical microscope. And visually evaluated whether the shape of each ink dot showed a perfect circle.

(Double-circle): The shape of an ink dot is a perfect circle and is a very favorable level.

◯: The shape of the ink dot is circular and is at a good level.

Δ: The shape of the ink dot is almost circular, but part of the shape is disordered, which is slightly poor.

X: The ink dot shape is unstable and has a bad level.

[0161] · Recordability of pigment ink

Using printer B (pigment ink type), photographic image CFIS X 9204 compliant "High-definition color digital standard image (XYZZSCID) data", image identification code: Nl, image name : Glass and female) were printed, and the uniformity of the printed part was visually evaluated.

A: The printed part is uniform and no printing unevenness is observed.

◯: Slight printing unevenness is observed, but there is no practical problem.

Δ: Slight printing unevenness, which is a slightly problematic level for practical use.

X: There is uneven printing and is a serious problem in practical use.

[table 1]

Industrial applicability

The ink jet recording material of the present invention has recording suitability suitable for dye-based and pigment-based ink jet printers aiming at photographic image quality, and since the print density is high, the color of the printed image is vivid and extremely practical. is there.

Claims

The scope of the claims

[1] On the support or at least one undercoat layer formed on the support, silica, alumina, and alumina hydrate strength as a pigment, at least one selected from a binder, and a crosslinking agent for the binder A method for producing an ink jet recording material, comprising: forming an ink receiving layer, and applying a surface layer coating liquid containing colloidal particles and an ink fixing agent on the ink receiving layer to form a surface layer.

[2] The method for producing an ink jet recording material according to [1], wherein among all the ink fixing agents contained in the ink receiving layer surface of the ink jet recording material, 75% by mass or more is applied by the surface layer coating liquid.

[3] The method for producing an ink jet recording material according to claim 1 or 2, wherein the colloidal particles contained in the surface layer coating liquid are cationic colloidal silica.

[4] The surface layer is formed by pressure-bonding to a heated mirror-finished metal surface while the surface layer coating liquid is in a wet state. The manufacturing method of the inkjet recording material as described in a term.

[5] A support, or at least one subbing layer formed on the support, and at least one selected from silica, alumina, and alumina hydrate strength as a pigment, binder

And an ink receiving layer containing a crosslinking agent of the binder, and a surface layer formed on the ink receiving layer and containing colloidal particles and an ink fixing agent.

[6] The ink receiving layer further contains an ink fixing agent, and the ink fixing agent is distributed on the surface layer side so that the concentration gradually decreases toward the support side. Item 6. The ink jet recording material according to Item 5.

7. The ink jet recording material according to claim 5 or 6, wherein the colloidal particles are gas phase method aluminate or cationic colloidal silica.