US2873668A

US2873668A - Azo dye duplicating process

Info

Publication number: US2873668A
Application number: US348584A
Authority: US
Inventors: Robert J Klimkowski; Robert T Florence
Original assignee: AB Dick Co
Current assignee: AB Dick Co
Priority date: 1952-10-25
Filing date: 1953-04-13
Publication date: 1959-02-17
Anticipated expiration: 1976-02-17
Also published as: US2795504A

Description

xaWLHEZF I copy sheet fof rea ies with'the essential dye fo A-ZO DYE DUPLICATING PROCESS Robert J. Klimkowski, Chicago, and Robert T. Florence, Park Ridge, 111., assignors to A. B. Dick Company, Niles, III., a corporation of Illinois No Drawing. Application April 13, 1953 Serial No. 348,584

Claims. (Cl; 101+14'9A) This invention re1ate's to a copy' process, andjmere tion is made of a new and improved copy process of the duplicating type which eliminates many of the objecti'onable features" of the present spirit duplicating prdc ess. The improved process retains the simplicity and ease of operation ch'ar'acteristic of the spirit duplicating system' 'but eliminates its objectionable's'oiling characteristicsre'sulti'n'gfrorn' the use of a highly water soluble' dye in theicompositionQof the imaging material. In stead'of making use, of a highly water and alcohol-soluble dye; the-imaging compositi'oii'of the inventions" described ,in' the' 'copending applications embodies a dye-forming component which is substantially free o'f any dye'color and'which is soluble in thefluid applied to the surface of'the-impression paper and is thereby leached for transferbfrom the' imaged masterto' the jmpressionpapen In the inipression paper, the dye forrni'ng component com bines with other materials nec'essary for reaction to form the dyestuff in the full development of the image.

In the diazo dye system described, 'the-dia'iocoi'npound I may be provided in the imaging material with which-the carbon sheet is formed'lan'd with which; the master is aged, while the coupler may be suppliedin the'fiuidor in the copy sheet for reactionwith the diazo' to form'the dyestuffs. In the alternative, the coupler may be pipvided as the essential component in-tlie'ima'ging material 50 I r i the form of an aromatic amine in a sufl icrently ac1d1fied and the diazo supplied in the fluid:orin the impression aper for reaction Witli' nie coupler upon transfer from theimageti areas: of the master sheet to form the azo avenue"; Insteadthe c' apier andniej diazo, stabilized against re on' with: the couplen may beprpvided'i'n high concentifat'ionih' the imaging material for reaction tofo'rin the aid dyestulf upontrerisferto the-im pr'e'ssiofnf paper in'r espbnse to the adjustment of the pH:

with materials'coiita ned' a's a'riielinentin the" iluid wayof still rnnn'er meeifieatieanie base of the'coupler or'thedi'a'zo adapted to e supplied in the' fluid or in the co mence n mfthe" image of: therha's'ter may be supplied in second t me tar wetting the impre se pane i b qu a'tft 6min h h image The" dirtines and staining char iicteristicsf of the spi duplicating process heretofore) employed has" been sub-[ stantially completely eliminated by the processes described without loss of simplicityjorfle'ase of operation characteristic of the spirit duplicatingrsystcm as ithas been known up to the present date. [It i s belije production of multiple tes Patent 2,873,668 were? Fee-13 5 ice I the cost of the ingredients and to increase the stability of the ingredients to light and heat so as to provide for the production of uniform copies at less cost and without limitation as to the life of the im'agingmaterial or the conditions of storage of the various elements.

Improvements arealso believed possible by way of modification to enable use of materials, which are less corrosive to duplicator parts and whichv would enable a wider selection of compounds to. increase the color range of the copy and with particularattenti'on to the possible development of a. more intense and complete black, which is not available now in duplicating systems of the type described. Q

I It is an object of this inventiouto provide still further improvements in a copy process of the type described, and it is a related object to produce various compositions and elements for use in same. 1

Another object is to produce a new and improved com position for use in the production of copy by a spirit duplicating process wherein the imaging material is free of dye color but in which the dye color is developed fullyv in the impression paper in response to transfer of dye-' forming components from the material forming the image in the master upon contact.

- I It is-a related object to produce a new and improved imaging composition in the form'of an ink, ribbon or transfer sheet and to produce a new and improved master, e ac h of which are substantially free of dyecolor but which may be used'jn a conventional spirit duplicating 1 machine for the production of copy of good quality, and

it is a related object to produce a n-ew and improved duplicatingprocess which makes use of the same.

.Morespecifically, it is-an object of this invention to provide a new andimprovedduplicatingprocess of the compounds of a greater variety and lower cost may be:

used to produce copy in a greater range of colors, in-f cluding black,

the materials used in the'pracace of the. process-are more stable to heat and light and,

d 7 however; 7

that still further improvements are possible'in a"sys"ten1 therefore, capable of, use in the production of agreater number copies of a uniform uality With less effect from time; temperature or atmospheric conditions and which are less corrosive to duplicator parts and materials is gonna the'rewith;

It has been found that the aforementioned improvestems in the processes previously described are achieved in a: system which makes use of a diazotizabl e amine in environment for reactionto cause an alkalinitrite'to decompose into nitrous acid Whichreactsjwith the amine to' forma'diazo' compound. Thediazo formed is capable stre ms, with: a coupler; as before, to f'orm the azo' dyestuif. The coupler may be provided in the form of the amine when present in excess of that required to react with the nitrite, or it may be provided as an auxiliary compound qf the-type described in the co-pending applications. T heacidifying medium may constitute an acid in troduced as a separate component, or it may be present in the form of anacidgroup; such: as a' sulfohic acid group, or as a part of" the amine saltl' As in the process of the co-pending applications which make use only of a diazo and'coupler, with or vithout' a base for pH adjustment, numerous permutations are possible in the practice of this invention, a number off which will hereinafter be described; Since the dia zotizable amine. constitutes the more expensive of the elements, arid" since the amine sometimescauses.thedevelopment.

of background color, it is preferred to embodythe'ainine as one of the essential components in the imaging maasvaess 3 terial. It will be understood, however, that the diazotizable amine, or an amine salt, may, in the alternative, be incorporated as a component in the impression paper or may be applied as a component in the fluid applied to the impression paper in advance of contact with the image master or even in a second fluid applied to the surface of the impression paper after contact with the image master. In either event, the amine is provided in the impression paper to react with the latent image formed on the surface of the impression paper to form the dyestutf.

When, as is preferred, the diazotizable amine is embodied as an element in the imaging composition, the following combinations are possible:

A. With the amine salt in the imaging material, the nitrite, such as sodium nitrite, may be incorporated (l) in the fluid with which the surface of the impression paper is wet in advance of contact with the imaged master; (2) the sodium nitrite may be embodied in the impression paper as by a prior coating process or by providing the nitrite in the slurry from which the impression paper is prepared; or (3) the sodium nitrite may be applied from a second solution with which the surface of the impression paper is wet after contact with the imaged master.

B. With the amine salt and acid in the imaging ma terial, the disposition of the nitrite may be in either of the elements (1), (2), or (3) of A above.

C- Both the amine salt and the nitrite may be compounded as components of the imaging material and the acid for reaction with the nitrite incorporated in (1) the fluid, (2) the impression paper, or (3) in a second fluid applied to the impression paper after contact with the imaged master.

When a separate coupler is used, it may be incorporated either in the imaging material or in the fluid, or in a second fluid in each of the combinations (A), (B) and (C) previously described.-

It will be 'apparentthat a number of permutations are also possible with the nitrite in the imaging material and the amine, coupler and acids arranged together or separately in the other elements, including the fluid with which the impression paper is wet in advance of contact with the imaged master, or a second fluid applied to the surface of theimpression paper after contact with the imaged master. It is only necessary that a separation between the-respective elements be maintained as between the acid and the nitrite so as to avoid the premature formation -.of nitrous acid used to formthe diazo of the amine, and it is also essential in governing the arrangement ofelements in accordance with the practice of this invention to make use of only those components in the imaging material which are soluble in the fluid applied to the; surface of the impression paper so as to effect the desired leaching of the dye-forming components from the image of the master to the impression paper for reaction to form the dyestutf.

The following will illustrate the practice of this invention in a combination wherein the imaging material is formulated to contain the amine salt and the fluid used therewith in the production of brown copy contains the nitrite:

EXAMPLE 1 Imaging material for use in the production of a transfer carbon In the preparation of the transfer carbon, the materials are combined together to form a hot melt at a tempera ture of between 80 to 100 C. as by a milling machine '4 using heated rolls, and then coated onto a web of paper to form coating weights of about 15 to 25 lbs; per 3,000 sq. ft. of surface area. The coating formed constitutes a surface coating which is weakly bonded to the backing sheet so as to enable easy displacement onto the surface of the master in response to applied force.

EXAMPLE 2 Fluid composition for use with the imaging composition of Example 1 86.0% by weight methanol 10.0% by weight water 4.0% by weight sodium nitrite In use, the coated surface of the transfer carbon produced with the composition of Example 1 is placed in contacting relation with the surface of a master sheet. The image is formed on the master sheet by transfer of coating from the carbon in response to applied force as by a die impression, typewriter key, or by a stylus.

The master having the image in reverse is then mounted in a standard spirit duplicating machine and the impression paper is fed into contacting relation with the imaged surface of the master after the surface of the impression paper has been wet, as by means of a wick or a wiper blade, with the fluid of Example 2.- Upon contact, the solvent portion of the fluid leaches some of the amine salt from the imaged areas of the master. for transfer to the impression paper. The acidic salt causes the nitrite in the fluid on the impression paper to revert to nitrous acid, which reacts with the amine portion to form a diazo compound. The diazo couples with the remainder of the amine to form an azo dye to produce copy in the im-.

pression paper. These reactions occur substantially'simultaneously so that the formation of a dyestulf becomes apparent by the time the impression paper passes from between the printing couple of the duplicating machine,-.

but the intensity of the dyestutf increases upon standing, especially if the papers are stacked in a manner to hold in some of the fluid whichiunctions as an ionizingmedium to continue the reaction.

The following example illustrates the combination when the imaging material contains both the amine and acid as separate ingredients for reaction with a nitrite contained ina fluid as in Example 2, or in a second fluid:

EXAMPLE 3 A transfer carbon is formed as previously described from a hot melt of the above composition. When used in combination with the fluid of Example 2 to produce copy on the impression paper, a blue dyestuif is formed. In this system, the acid and the amine salt, soluble in alcohol and water, are leached from the imaged master for transfer to the impression paper upon contact with the surface of the impression paper wetted with the fluid of Example 2. There the acid reduces the nitrite to nitrous acid. The nitrous acid reacts with the amine salt to form a diazo and thenthe diazo couples with the remainder of the amine to form the blue azo dyestuif.

The following will illustrate the combination wherein a separate coupler is incorporated with the amine in the form of an acid salt" in the imaging material and the nitrite is provided either in the fluid, in'the impression paper, or in a second fluid:

EXAMPLE 4 12.0% by weight carnauba Wax 17.0% by weight microcrystalline wax 14.5% by weight lactic acid 13.0% by weight heavy mineral oil 1.5% by weight sodium oleate 21.0% by weight 2,4 diaminotoluene I t 21.0% by weight paranitroaniline hydrochloride A transfer carbon is formed as previously described, using a hot melt of the composition of Example 4. When impression paper having its surface wet with the fluid of Composition 2 is brought into surface contact with av master imaged with the composition of Example 4, the 2,4 diamino toluene and paranitroaniline hydrochloride are leached from theimage to the impression paper for reaction to transpose the nitrite into nitrous acid which reacts with the amine to produce a diazo. The diazo reacts with the coupler to produce the azo dyestuff.

The following are further modifications of the system described in which various combinations of amine salts and acid salts are formulated into the imaging material:

EXAMPLE 5 12.0% by weight carnauba wax- 17.0% by weight Cardis 262 wax 14.5% by weight heavy mineral oil 130% by weight light mineral oil 1.5 by weight sodium oleate v I v 42.0% by weight triaminotoluene trihydrochloride EXAMPLE 6 12.0% by weight carnauba wax 17.0% by weight Cardis 262 wax 14.5% by weight heavy mineral oil 13.0% by weight light mineral oil 1.5% by weight sodium oleate o 15.0% by weight m-phenylenediamine dihydrochloride' 27.0% .by weight p-amino-N,N-diethylaniline hydrochloride 1 V EXAMPLE 7 12.0% by weight carnauba wax 17.0% by Weight Cardis 2 62 wax 14.5% by weight heavy mineral oil 13.0% 'by weight light mineral oil 1.5 by weight sodiumoleate v i 42.0% by weight p-amino-N,N diethylaniline hydrochlo- .rid'e EXAMPLE 8 12.0%"by weightcarna'iiba wax 170% by weight Cardis 262 wax 1415 by weight heavy mineral oil 13.0% by weight lightrnineral oil 1.5 'by weight sodium oleate H r 15.0% by weight m-phenylenediamine dihydrochloride 27.0% by weight benzidinedihydrochloride EXAMPLE 9- 12.0% by weight carnauba wax 17.0% "by weight Cardis 262 w'ax 14.5% by weight heavy mineral oil 13.0% by weight light mineral oil 1.5 byweight sodium oleate I 20.0% by weightp-aminodiphenylamine hydrochloride 22:0 by weight rheny1-s-n1sth r5- yrazo1ene in'g; material embodying features of this -inveritio1i,-illus-" "75 trat'io'n was made of formulations for use in the preparation of a transfer carbon which is the means most often used for imaging a master. Use may also be made of other waxes such as paraflin wax, ozokerite wax, [and other natural, petroleum, coal tar or vegetable waxes, or synthetic waxes, alone or in combination with softening or fluidizing agents such as mineral oils, vegetable oils, fatty acids, fatty acid esters, hydrogenated rosin, plasticizers, and the like, in various amounts and proportions, depending on whether use is to be made to produce a transfer carbon or whether a more fluid composition is desired for use in a typing ribbon, or an ink for application by a writing pen, stylus, or the like, to image the .master.

As will be evident from the examples, the amines,

' amine saltsr or amine acid salts, may 'be selected of a large number of commercially available diazotiz able aromatic amine compounds. When incorporated as a component of the imaging material, it is important that the diazotizable amine components and the other com ponents entering into the reaction to forni the dyestufi be soluble in the fluid composition with which the impression paper is wet and the amines should be, reactive with nitrous acid to form a dye compound capable of.

reaction with the coupler to form vthe dyestuff.

When the coupler is applied as a component of the imaging material, separate and apart from the amine, it is preferred to make use of a coupler in the form of an organic compound such as an aromatic amine of the type aniline "or a substituted aniline such as dimethylaniline or With the fluid of Example 2, brown copy is produced phenolic cornpounds such as phenol, resorcinol, phloroglucinol,"2,'3 dihydr'oxy' naphthol'sulfonie acids, or thio compounds such as thiobarbituric acid, or cyano can pounds such as cyanoaeetamide, or pyrazolone, or derivatives thereof. i t I While dilute solutions" of inorganic acids may be' used as'the acidic medium when incorporated infafluid or,

when incorporated as a component in' the, imaging rn'at'e rial separate and apart: from the nitrite, it preferred make use of organic acids'of the type stearic acid, lactic acid, formic acid, propionic acid, benzoic acid, and the like. The amount of acid is unimportant, since it is only necessary to have sufiicient' acid present to cause theforrnation of nitrous acid uponreaction with alkali metal nitrite. V a

For thepr'oper production of a maximum'number or copies, it is desirable to incorporate as high concentra-f non of the diazotizable amine or other components of the dye'as is'po'ss'i ble int-o the imaging composition consi-stent'withthe ability of the composition to embody the" characteristics necessary for imaging purposes or for the manufacture of a suitable transfer carbon. Generally,- it is desirable to have a concentration of the dye-forming component presentin amounts greater than 20%; by'

Weight of the imaging composition and concentratibris up "-to by weight can'- be tolerated without interfering with the characteristics of the material for the purpose for which it was intended; Where the dye-forming components contained in- .the imaging material or the composition vfor forming the coating on the transfer carbon comprise two components such as a diazotizable amine,

a diazotizable amine and coupler, or a diazotiz'able' amine and nitrite, the concentrations are preferably reduced to an amount greater than 20% by weight but less than an amount capable of forminga total of 75% by weight of the imaging composition. In" a diazotiza ble amine-coupler system itis preferable to have more amine than coupler such as in a ratio of l- -3 to 1. Lesser concentrationsof the nitrites' are required, it being suflicient when the amount in the imaging materialis within the range of from 1-15% by weight. 7 The following examples are illustrative of other permutations which may be made with respect to the ,distrrbu'tro'n of the: Various components in the compositions used-in the pr'actice'of the duplicating process.

For example; the following willi'illust'rat e the system aa'raees.

wherein an amine salt or an amine-salt and a nitrite are formulated to be contained in the imaging material while the fluid contains the solvent or the acidic medium necessary under certain circumstances for conversion of the nitrite to nitrous acid.

EXAMPLE 10 Carbon-coating composition by weight carnauba wax by weight microcrystalline wax 14.5% by weight heavy mineral oil 13.5% by weight light mineral oil 1.5% by weight sodium oleate 5.0% by weight sodium nitrite 37.0% by weight m-phenylenediamine dihydrochloride EXAMPLE 11 Fluid 90% by weight methanol 10% by weight water EXAMPLE 12 45.0% by weight 1amino-2-naphthol 4-sulfonic acid 15.0% by weight sodium nitrite 5.0% by weight carnauba wax H 10.0% by weight oxidized microcrystalline wax 25.0% by weight light mineral oil EXAMPLE 13 Fluid composition for use with the imaging composition of Example 12 r 4.0% by weight l.-phenyl-3-rnethyl5-pyrazolone 2.0% by weight lactic acid 94.0% by weight methanol With the system of Examples 12 and 13 used in a copy process of'the type previously described, a red dyestuft forming the copy in the impression paper will result.

Another system similar to that of Examples 12 and 13 wherein the amine salt and nitrite are contained in the imaging material and the acid contained in the fluid, is illustrated by the following further examples:

EXAMPLE 14 Imaging composition 25.0% by weight 1 amino, Z-naphthol, 4-sulfonic acid 20.0% by weight phloroglucinol 15.0% by weight sodium nitrite 5.0% by weight carnauba wax 10.0% by weight oxidized microcrystalline wax 25.0% by weight light mineral oil EXAMPLE 15 Fluid composition for use with Example 14 3.0% by weight lactic acid 7.0% by weight water 90.0% by weight methanol When the impression paper having its surface wet with the fluid composition of Example 15 is brought into surface contact with the master imaged with the composition of Example 14, the dye-forming components transfer from the imaged areas of the master to the impression paper, where the lactic acid causes the sodium nitrite to form into nitrous acid. This forms the diaz0 compound of the l-amino, Z-naphthol, 4-sulfonic acid,

which then reacts with the phloroglucinol coupler to form the azo dyestuff.

' The following example illustrates the practice of this invention when the amine salts and coupler are contained in the imaging material and the sodium nitrite is contained, as is often desirable, in the impression paper while the fluid merely constitutes a solvent for the amine salt and coupler to effect transfer from the imaged master to the impression paper for reaction in the manner previously described.

EXAMPLE 16 Imaging composition 12.0% by weight carnauba wax 17.0% by weight rnicrocrystalline wax 14.5 by weight heavy mineral oil 13.0% by weight light mineral oil 1.5 by weight sodium oleate 27.0% by weight p-amino-N,N-dimethylaniline monohydrochloride 15.0% by weight m-phenylenediamine dihydrochloride EXAMPLE 17 Composition for coating the impression paper to introduce sodium nitrite 86.0% by weight methanol 10.0% by weight water 4.0% by weight sodium nitrite In the use of the compositions of Examples 16 and 17.,

the impression paper is first coated with the fluidsystem of Example 18 and then allowed to dry to set the sodium nitrite in the surface portion of the paper. In the production of copy, paper which has been treated with the.

composition of Example 17 is wet with methanol before being brought in contact with. the master imaged with the composition of Example 16. The methanol causes the amine salts and coupler to be leached for transfer from the imaged master to the impression paper, where reaction takes place to form nitrous acid from sodium nitrite, followed by diazotization of the amine and coupler to form the azo dyestufif.

The following will illustrate the practice of this in- ,vention wherein the nitrite is contained as the dye-forming component in the imaging material and the amine salt is contained as a component in the fluid.

EXAMPLE 18 12.0% by weight carnauba wax 17.0% by weight microcrystalline wax 14.5 by weight heavy mineral oil 13.0% by weight light mineral oil 1.5% by weight sodium oleate 42.0% by weight sodium nitrite EXAMPLE 19 Fluid for use with composition of Example 18 5.0% by weight methyl-p-phenylenediamine dihydrochloride 10.0% by weight water 85.0% by weight methyl alcohol With the system of Examples 18 and 19, intense black copy will be produced. a

When a two-fluid system is used to produce copy, the essential component for completion of the reaction may be incorporated in a second fluid applied to the surface 'of the impression paper after the latter has been in contact with the imaged master and contains a latent image,

est-sees formed fliereim' For example, the sodium nitrite of Example 2 may be; deleted from the solution and incorporated in a corresponding concentration in a separate aqueous system. In use, the master imaged-with the compositions of either Examplesl and 3' to 9 is first contacted with the impression paper having-its surface wet with a solvent such as methanol and water. The amine salts, and acid when present, and coupler when present; will be extracted by the solvent for transfer from the imaged master to the impression medium to form a latent image therein. When the surface of the impression paper is subsequently wet with a solution containing the nitrite, the acid will function to convert the nitrite to nitrous acid which will react then with the amine to form the diazo, which then couples to form the respective azo dyestuff in the development of copy. I

The acid may be separated from'the fluid of compositions 13 and 14 for incorporation in a second fluid as described for use in a two-fluid system with a master imaged with the composition of either Example 12 or Example 14, respectively.

Itw'ill be apparent from the description that the process described herein provides for further improvements in a duplicating system which has the simplicity of the present' spirit duplicating process without the handicap of dye transfer and stain during the manufacture of imaging material or in the handling thereof to produce a transfer ribbon or a transfer carbon or in the use thereof in the preparation of an imaged master and the use thereof to produce copies. A system of the type described enables the production of a greater range of colors in the formation of copy and it permits the formation of copy from a dyestuff which is relatively insoluble and, therefore, incapable of being destroyed in response to moisture or high humidity. The elimination of a diazo as a component of the described system also permits the utilization of lower cost of materials in the copy process and the production of elements for use in the multiple copy process which are substantially free of color and substantially devoid of the development of any background color when incorporated into the impression paper.

It will be understood that a system of the type described may be employed when the essential dye-forming components in the imaging material are substantially soluble in water in the copy process heretofore referred to as the process of hectographic duplication.

It will be understood that changes may be made in the details of construction, formulation and application without departing from the spirit of the invention, especially as defined inthe following claims.

We claim? 1. The method of producing copy with a master imaged with a composition containing an acidic medium and an amine compound capable of diazotizatiomcomprising the steps of wetting the surface of an impression paper with a fluid containing a solvent for the diazotizable amine and acid and also containing a nitrite and a coupler, and contacting the imaged surface of the master with the wetted surface of the impression paper, whereby some of the diazotiza'ble amine compound transfers from the imaged portion of the master to the impression paper for reaction to form the azo dyestuif.

2. The method of producing copy with a master imaged with a composition containing an alkali metal nitrite and a diazotizable amine compound present in a concentration ranging from -75% by weight of the composition and capable of coupling reaction to form an azo dyestutf, comprising the steps of wetting the surface of an impression paper with a fluid containing a solvent for the amine compound and the nitrite and also containing an acid and coupler for reaction to form nitrous acid of the nitrite, and contacting the imaged surface of the master with' the wetted surface of the impression paper, whereby some of the diazotizable amine compound and nitrite transfers from the imaged portion of the master to the impression.

paper for reaction to form the azo dyestuif.

3. The method of producing copy with a 'master imaged with a composition containing a diazotizable amine compound present in an amount within the range of 20-75%; by weight of the composition and an acidic medium for reaction to form nitrous acid of a metal nitrite, comprising the steps of wetting the surface of an impressionpaperwith a fluid containing a solvent for the diazotiza'ble amine compound and the acidic medium and which also contains the diazotized amine, comprising the steps of wetting the surface of an impression paper with a fluid containing a' solvent for the diazotizable amine and coupler and which also contains a nitrite and anacidic medium for reaction" Withthe diazotizable aminecompound in'the presence of nitrous acid, and contacting the imaged surfa'ce of the master with the wetted surface of the impressionfp'aper, whereby some of the diazotizable amine and coupler is" leached for transfer from the imaged portion of the master to the impression paper and reacts with the nitrite to form an azo dyestuff.

5. The method of producing copy with a master imaged with a composition containing a diazotizable amine compound capable of reaction with a coupler to form an azo dyestuif, a coupler and an acidic medium, comprising the steps of wetting the surface of an impression paper with a fluid containing a solvent for the diazotizable amine, coupler and acidic medium and which also contains a nitrite, and contacting the imaged surface of the master with the wetted surface of the impression paper, whereby some of each of the dye-forming components in the imaged portion of the master are leached for transfer to the impression paper for reaction to form the dyestuif.

6. The method of producing copy with a master imaged with a composition containing an alkali metal nitrite present in a connection within the range of 115% by weight of the composition, comprising the steps of wetting the surface of an impression paper with a fluid containing a solvent for the nitrite and which also contains an acidic medium and a diazotizable amine salt capable also of acting as a coupler to form an azo dyestuif, contacting the image surface of the master with the wetted surface of the impression paper, whereby some of the nitrite is leached for transfer from the imaged portion of the master to the impression paper for reaction to form an azo dyestufli.

7. The method of producing copy with a master imaged with a composition containing an alkali metal nitrite present in a concentration within the range of 1-15% by weight, comprising the steps of wetting the surface of an impression paper with a fluid containing a solvent for the nitrite and also containing a diazotizable amine compound, a coupler, and an acid, and contacting the imaged surface of the master with the wetted surface of the impression paper, whereby some of the nitrite is leached for transfer from the imaged portion of the master to the impression paper for reaction to form the dyestuif.

8. The method of producing copy with a master imaged with a composition containing an alkali metal nitrite and a coupler capable of reaction with a diazo compound to form an azo dyestufr", comprising the steps of wetting the surface of an impression paper with a fluid containing a solvent for the nitrite and coupler and which also contains a diazotiza'ble amine compound and an acid, and contacting the imaged surface of the master with the wetted surface of the copy sheet, whereby some of the nitrite and coupler is leached for transfer from the imaged portion of the master to the impression paper for reaction to form an azo dyestuif.

. 9. The method of producing copy with a master imaged with a composition containing an acidic medium and an amine compound capable of diazotization, comprising the steps of contacting the imaged surface of the master with an impression paper, wetting the surface of the impression paper, prior to contact with the imaged master and again subsequent to contact with the imaged master, with fluids, the first of which contains a solvent for the diazotizable amine compound and the acidic medium and the second of which contains a nitrite and a coupler for reaction with the diazotizable amine compound, to form an azo dyestutt.

10. The method of producing copy with a master imaged with a composition containing an alkali metal nitrite and a diazotizable amine compound present in an amount within the range of 20-75% by weight of the composition and capable of coupling reaction to form an azo dyestuif, comprising the steps of contacting the imaged surface ofthe master with an impression paper, and wetting the surface of the impression paper before and after contact with the imaged master with fluids, the first of which contains a solvent for the diazotizable amine compound and nitrite, and the second of which contains an acid and a coupler.

References Cited'in the file of this patent UNITED STATES PATENTS 831,582 Thorpe Sept. 25, 1906 1,514,222 Murray Nov. 4, 1924 1,571,320 Clavel Feb. 2, 1926 1,646,296 Kircheisen Oct. 18, 1927 1,825,342 Dreyfus et a1 Sept. 29, 1931 2,146,976 Neidich Feb. 14, 1939' 2,217,349 Neidich Oct. 8, 1940 2,364,359 Kienle et al Dec. 5, 1944 2,526,995 Clark Oct. 24, 1950 2,554,909 Holik May 29, 1951 2,596,756 Yutzy et a1 May 13, 1952 2,634,677 Klimkowski et a1. Apr. 14, 1953 FOREIGN PATENTS 193,646 Great Britain Mar. 1, 1923 OTHER REFERENCES Diserens: The Chemical Technology of Printing and Dyeing, 1948, Reinhold Pub. Co., N. Y. Only pp. 266 to 269.

Saunders: The Armatic Diazo Compounds, 2nd edition, 1949, Arnold & Co., London. Only pp. 95, 96 and 97.

Claims

1. THE METHOD OF PRODUCING COPY WITH A MASTER IMAGED WITH A COMPOSITION CONTAINING AN ACIDIC MEDIUM AND AN AMINE COMPOUND CAPABLE OF DIAZOTIZATION, COMPRISING THE STEPS OF WETTING THE SURFACE OF AN IMPRESSION PAPER WITH A FLUID CONTAINING A SOLVENT FOR THE DIAZITIZABLE AMINE AND ACID AND ALSO CONTAINING A NITRITE AND A COUPLER, AND CONTRACTING THE IMAGE SURFACE OF THE MASTER WITH THE WETTED SURFACE OF THE IMPRESSION PAPER, WHEREBY SOME OF THE DIAZOTIZABLE AMINE COMPOUND TRANSFERS FROM THE IMAGED PORTION OF THE MASTER TO THE IMPRESSION PAPER FOR REACTION TO FORM THE AZO DYESTUFF.