CA1060282A

CA1060282A - Decorative sheet material formed from plastic layer containing chips and blowing agent

Info

Publication number: CA1060282A
Application number: CA237,170A
Authority: CA
Inventors: Edward R. Erb; David L. Leyfert; Kenneth J. Faust
Original assignee: GAF Corp
Current assignee: GAF Corp
Priority date: 1974-12-30
Filing date: 1975-10-07
Publication date: 1979-08-14
Also published as: DE2551163A1; JPS5180380A; AU8564175A; IE41914B1; GB1525108A; NL7515170A; IT1043717B; IE41914L; FR2296540A1

Abstract

ABSTRACT OF THE DISCLOSURE

Decorative sheet-type covering material having a textured surface is prepared by first forming on a substrate a layer of wet polyvinyl chloride plastisol or organosol. Non-foamable chips or foamable chips containing blowing agent are embedded in the wet plastic layer which is then heated to a temperature sufficient to cure the plastic and decompose the blowing agent, to thereby foam the chips and impart a textured surface to the plastic layer. Polyvinyl chloride plastisol or organosol is the preferred plastic and a conventional topcoat or wear layer of polyvinyl chloride or polyurethane may be used. The textured surface has a height variation due to the chips of at least 4 mils.

Description

This invention relates to a decorative sheet-type convering material having a textured surface and to a method for preparing such material.
Decorative sheet-type covering materials such as vinyl floor coverings are well known in the art and various attempts have previously been made to impart three-dimensional textured characteristics to the surface of such materials. A
number of processes have been suggested for this purpose. For instances, United States 3,458,337 to Rugg suggests a method for producing a textured surface by employing a resin layer contain-ing a catalyst activated foaming agent and then applying in selected/ipattern areas an agent for suppressing the catalytic action of the catalyst. United States 3,293,094 to Nairn et al also makes use of a chemical inhibitor to control the extent of foaming which takes place on various portions of the material.
United States 3,585,099 to Van Buskirk discloses the possibility of partially embedding foamed granules into a vinyl layer and the spraying the granules with a thin layer of plastisol. Mechan-ical embossing has also been used to obtain three-dimension~l tex-tured surfaces.
Unfortunately, none of the prior art techniques described above has proven entirely satisfactory. ~echanical embossing, for instance, does not easily achieve the fine texture which is desired because of the tendency for the entire layer of foamed material to be crushed. Likewise, the various '' - 106~Z8~' chemical techniques previously proposed have failed to produce textured material of the desired quality. The tendency usually is for large areas of the surface to be affected and more precise results such as a sharp, pebbled appearance with a wear layer of adequate thickness have been difficult to obtain.
In accordance with one aspect of the invention, a decorative sheet-type covering material is provided which as a textured surface and comprises a substrate, a cured plastic layer comprising cured PVC plastisol or organosol, said plastic layer having foamed chips comprising gelled, plasticized vinyl composition embedded therein; and a cured, textured wear layer comprising polyurethane or cured PVC plastisol or organosol over said plastic layer, said wear layer being a minimum of about 4 mils thick and the surface of the wear layer having a height variation due to the foamed chips of at least 4 mils.
According to another aspect of the invention, a decorative sheet-type covering material having a textured surface comprises a substrate, a cured, foamed plastic layer adhered to said substrate, said plastic layer having non-foamable chips embedded therein; and a clear, cured, textured plastic wear layer over said foamed plastic layer, said wear layer having depressions in the surface thereof corresponding to the location of the non-foamable chips within the foamed plastic layer and said wear layer having a minimum thickness of about 4 mils and a height variation of at least4 mils due to the presence of the chips.
According to one aspect, the method of the invention consists of a process for making a decorative sheet-type covering material having a textured surface characterized by forming a layer of wet non-foamable plastic on a substrate, said layer having foamable chips containing blowing agent embedded therein; and heating said layer to a temperature sufficient to cure same and decompose said blowing agent, thereby foaming said chips and imparting a textured surface to the material, the textured surface having a height variation due to the chips of at least 4 mils.

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According to another aspect, the method of the invention consists of a process for making decorative sheet-type covering material having a textured surface which comprises: forming a foamable plastic layer on a substrate, said layer containing blowing agent and having non-foamable chips embedded therein; and heating said layer to a temperature sufficient to cure same and decompose said blowing agent, thereby foaming said layer and impart-ing a textured surface to the material due to the effect of the non-foamable chips, said textured surface having a height variation due to the chips of at least 4 mils.
In a preferred embodiment of the invention~ the plastic layer containing the non-foamable or foamable chips is gelled and a clear wear layer applied before the plastic is curedO The wear layer may preferably comprise polyurethane or PVCO
In the drawings, Figures la and lb are fragmentary sectional views through a pre-ferred floor covering material of the inventionO In these views it is not intended that the thicknesses of the various layers of the products shown are precisely represented. Rather, the various layers are represented on a considerably large scale and without showing precise relationships between thicknesses of the layersO
Figure 2 is a flow sheet diagram representing a preferred process for making the product depicted in Figures la and lb.
Figures 3a and 3b are fragmentary sectional views through a pre-ferred floor covering material of the invention.
Figure 4 is a flow sheet diagram representing a preferred process for making the product depicted in Figures 3a and 3b.
As mentioned above, the product of the invention is a decorative sheet-type covering material having a textured surface and comprising a substrate, a cured plastic layer adhered to the substrate and having foamed , chips embedded therein and a textured wear layer over the plastic layer containing foamed chips. The substrate may include any suitable supporting material such as an asbestos sheet, a nonwoven fibrous web, a woven fibrous web, a plastisol layer, a plastisol layer on felt backing, etc. As an alternative the preferred product of the invention is a decorative sheet-type covering material having a textured surface and comprising a substrate, a cured, foamed plastic layer adhered to the substrate and having non-foamable chips embedded therein and a textured wear layer over the plastic layer containing such chips. The surface of the product material has sur-face depressions corresponding to the location of the chips. The substrate may include any suitable supporting material such as an asbestos sheet, a nonwoven fibrous web, a woven fibrous web, a plastisol layer, a plastisol layer on felt backing etc. ~hile almost any flexible base substrate may be used, the preferred substrate is felt, most advantageously an impregnated asbestos felt or a resin impregnated cellulose or other organic felt or, with suitable sealing coats, an asphalt-saturated organic feltO While felt is preferred, paper sheet, cloth or even metal foil may be used for some purposes such as wall coveringsO
The use of a sealing or priming coat is not considered essential but is preferred, especially where a felt base is used. Where used, the sealing or priming coat may be made up of a latex, for example a latex con-taining an acrylic polymer with or without pigments or fillers such as the prime coat described in United States Patent 3,458,337 to Rugg.
The cured plastic layer adhered to the substrate is, as mentioned above, preferably a cured PVC plastisol or organosol and has non-foamable or foamed chips embedded therein. Such PVC plastic may be any of the various PVC resin materials normally used in connection with coating of decorative sheet materials and may specifically include but is not limited to those described in the above-mentioned United States Patent 3,458,3370 -The foamed chips used in the product of the invention may be formed as described in more detail below and may be opaquely or translucently pigmented. The chips may be uniformly distributed throughout the plastic layer or may be distributed in patterns to produce desired effects of tex-ture on only some parts of the sheet. Where a wear layer over the sheet of plastic containing the chips is used as described herein, the chips serve to provide a textured surface to the wear layer which may have surface depressions corresponding to the location of the chips. The product of the invention is thus a sheet material having a textured surface, whether the surface be a wear layer or a layer of plastic containing the chips. In t order to provide the desired degree of texture and appearance it is neces-sary that the textured surface of the product material have a height var-iation due to the foamed chips of at least 4 mils. Greater variations such as about between about 5 and about 20 mils are preferred. By height variation is meant the difference in height above the substrate (with the material positioned horizontally as on a floor) between the lowest points on the surface and the highest points on the surface of the finished pro-ducto Such variation is~ of course~ in addition to any effects created by mechanical means such as embossing or chemical means such as previously known in the prior art described above3 In an~embodiment of the invention ~;
the desired surface effect is more readily obtained by including blowing suppressant in at least some of the chips.
For most applications, especially for use as flooring, the products of the invention should include a cured wc~r layer, over the plastic layer containing the chips. To provide necessary protection on flooring material, the wear layer should have a minimum thickness of about 4 mils, preferably at least about 7 mils and, depending upon the degree of protec-tion desired, may be substantially thicker, such as up to about 15 or 20 mils or more.

:. .. . ., . :. ' The wear layer may be any suitable material, such as polyurethane or cured PVC plastisol or organosol. Such materials are well known in the art and are described, for instance, in the above-mentioned Patent 3,458,337.
If desired, additional plastic coatirigs~and printing may be used in the manner well knolm in the art. For instance, a plain or foamed plastic layer may be included as part of the substrate on which the plastic containing chips is placed and printing may be applied either beneath or above the layer of plastic containing the foamed chips. In a preferred embodiment of the invention, a suitable pattern or printing is located between the plastic layer containing non-foamed or foamed chips and the wear layerO Also if desired, a foamed plastic layer may be located beneath the layer of plastic containing the foamed chips. Preparation of these various optional components as well as the layer containing the said chips is described in greater detail below~ Compositions, thicknesses and method used in applying these optional components, may be as conventionally known in the art including~ for instance~ but not limited to those described in the above-mentioned Patent 3,458,337~
While the products of the present invention provide a unique, pebbled textured surface appearance it should be understood that this unique appearance may be combined with other effects obtainable by the known prior art techniques, such as the mechanical and chemical techniques men-tioned above. Additional novel effects may thus be obtained since such prior art techniques tend to produce relatively larger and less well defin-ed surface appearances than the sharper textured appearance produced by the present invention~ For instance, the technique described in the above-mentioned patent 3~458,337 may readily be used to provide an overall brick design with the techniques of the present invention being used in the same material to provide a pebbled, textured appearance which may be pebbled either over the entire surface or, if desired, merely within the valleys ~:

of the basic design.
For a further appreciation of the unique structure and advantages of the material of the invention, reference may be had to the drawings and especially to Figures l(a) and l(b) thereofO Figure l(a) illustrates a section of a floor covering material of the invention before final curing of the plastic layers and foaming of the chips. As can be seen from Figure l(a) this preferred material includes a felt base, a latex prime coat, a plastic layer containing foamable chips, a pattern of printing over the plastic layer and a topcoat or wear layer which forms the outer surface of the product. Figure l(a) illustrates this product after the plastic layer containing the chips has been applied but before curing of the plastic and wear layer and foaming of the chips.
Figure l(b) illustrates the product shown in Figure l~a) after curing of the plastic and foaming of the chips. From Figure l(b) it can be seen that the foaming of the chips has resulted in protuberances and valleys being formed in the upper surface of the material with the protuberances corresponding to the location of foamed chips and that this has been accom- -plished while retaining substantially the same thickness wear layer over the chips and printingO This produces a unique pebbled texture on areas of the material in which the foamable chips are used.
As mentioned above, the basic process of the invention involves the manufacture of a decorative sheet-type covering material having a tex-tured surface by first forming a layer of wet PVC plastisol or organosol or a layer of wet polyurethane organosol on a substrate. In either case the layer has foamable chips containing blowing agent embedded therein. Also, a previously m~ntioned, PVC plastisol or organosol is preferred. Once a layer containing foamable chips embedded therein has been formed, the layer is then heated to a temperature sufficient to cure the same and decompose the blowing agent to thereby fpam the chips and impart a textured surface to the material.
As a further appreciation of the unique structure and advantages of the material of the invention, reference may be had to the drawings and especially to Figures 3a and 3b thereof. Figure 3a illustrates a section of a floor covering material of the invention before final curing and foaming of the plastic layers. As can be seen from Figure 3a this preferred material includes a felt base, a latex prime coat, a foamable plastic layer containing non-foamable chips a pattern of printing over the foamable plastic layer and a topcoat or wear layer which forms the outer surface of the productO Figure 3a illustrates this product after the foamable plastic layer containing the chips has been gelled and after the printing and wear layer have been applied but before foaming or curing of the plastic and wear layers.
Figure 3b illustrates the product shown in Figure 3a after curing of the plastic and wear layers and foaming of the foamable plastic layerO
From Figure 3b it can be seen that the presence of the chips has resulted in depressions being formed in the upper surface of the material correspond-ing to the location of the chips and that this has been accomplished while retaining substantially the same thickness wear layer over the chips and printing. This produces a unique texture on areas of the material in which the chips are used.
As mentioned above, the basic process of the invention involves the manufacture of a decorative sheet-type covering material having a textured surface by first forming a layer of foamable plastic on a substrate, the layer having non-foamable chips embedded therein. Also, as previously mentioned, PVC plastisol or organosol is the preferred plastic. Once such a layer has been formed, the layer is then heated to a temperature suffic-ient to cure the same and deccmpose the blowing agent in the layer to there-by foam the layer and impart a textured surface to the material due to the ;-presence of the non-foamable chips.
Also as mentioned above, embodiments of the invention involve the use of a separate clear wear layer over the layer of plastic containing chipso Where such a wear layer is used the plastic layer containing foam-able chips is normally gelled and the wear layer is then applied before the entire sheet is heated to a temperature sufficient to cure or foam the plastic layer and wear layer and form the chipso Where a printed pattern is used it may be applied to the gelled layer containing chips or to a plastic layer which may be used under the layer containing the chips. In any event the final curing of the sheet at temperatures sufficiently high to cure the various plastic layers and to foam the chips is not normally done until all of the layers have been applied. ;
The chips are preferably of gelled or fused plasticized vinyl composition which may contain a blowing agentO In one embodiment, at least a portion of the chips contain blowing suppressantO The chips may be opaquely or translucently pigmented. They may be prepared from extruded thin vinyl sheets, plasticized calendered sheets or sheets cast from plas-tisols, which are then chopped or diced into fine particles. Chips may conveniently be prepared using the same basic plastic composition used in forming the plastic layer in which the chips are embedded or in forming the wear layer. The chips used may include a wide variety of materials and may more specifically include both filled anf unfilled chipso For instance, the chips may be of the type described in United States Patent 3,682,741 to Elliott et al or those described in United States Patent 3,265,548 to Harkins et al with the addition of blowing agents as mentioned aboveO The term "chips" as used herein is intended to include not only chips formed ~ -as described immediately above but also other relatively small particles such as the gelled plastic particles described in United States Patent 3,345,235 to Miller or small plasticized particles. While size of chips --1~

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used is not critical, particles averaging between about 1/64 inch and about 1/8 inch in diameter or sheets between about 1 and about 10 mils thickness chopped into particles of about this size range are preferred.
Application of the chips to the wet plastisol or other plastic material forming the plastic layer within which the chips are to be embedded can be by suitable means such as sifting, screening, vibratory feeding, etc.
It is also within the scope of the invention to premix the chips with the plastic coating composition prior to spreading the coating composition of the substrate. After application of the plastic layer and chips the plastic may be cured or foamed immediately~ but preferably is gelled printed and then covered with a wear layer prior to final curing and foaming of chipso The foaming or blowing agent incorporated in the foamable chips may be any suitable blowing agent or catalyst activated blowing agent such as is known in the art for producing foamed plastisol or organosol layers ineluding~ for instance, such blowing agents as azodicarbonamide (ABFA) Gelling of plastic layers is carried out according to normal practices whereby the plastic material is heated sufficiently to gel but is not heated sufficiently to deeompose blowing agents. When the various desired layers have been applied and gelled, the entire sheet is heated to a temperature suffieient to cure the plastie (eg. fuse PVC plastisols or organosols) and also deeompose the blowing agent used in the foamable chips as well as any blowing agent used in other plastic layers. Typical blowing agent systems have decomposition temperatures within a range between about 300 F
and about 400 F. Typical conditions forgelling without decomposing blowing agents involve exposure to temperatures of, for instance, about 250 F for times of about 2 to 4 minutes or at higher temperatures for correspondingly shorter periods of time.
The blowing suppressant used in one of the embodiments of the invention may be any suitable suppressant for the blowing agent used in the . ., : ,..--. . :
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foamable layer having the chips embedded therein. The suppressant may be a direct suppressant but more usually is an inhibitor for a catalyst used to catalyze decomposition of the blowing agent used. In either case the blowing suppressant will migrate into the wet plastic layer in which the chips containing the suppressant are embedded and will substantially inhibit foaming of the foamable layer in the vicinity of the chips containing the suppressant. Suitab]e suppressants are known in the art and include those described in the above-mentioned United States Patents 3,458,337 and 3,293,094 such as ben~otriazole and aminotriazole.
1~ Where a clear wear layer is used over the layer of plastic containing the foamable chips, it is preferred prior to application of the wear layer to smooth the plastic layer containing the chips as by pressing the solidified, gelled layer against a roll. After the wear layer has been ~
applied and the wear layer and plastic layer containing chips cured and the ~ -chips foamed, the surface of the resulting sheet product will possess an -~ ~ -overall textured embossing in which the raised protuberances correspond to the location of foamed chips beneath the surface. If one or more inks containing a chemical suppressant are used to print over the plastic con-taining the foamable chips, these areas will be embossed in register.
Alternatively, as mentioned above the invention also contemplates the use of other conventional chemical and mechanical embossing techniques to sup- ~
plement the pebbled, textured appearance obtained by the practice of the -invention O ' If desired, foamable or nonfoamable chips may be mixed with foam-able chips in practicing the invention. If a foamed undercoating is used, the use of a mixture of nonfoamable or suppressant chips and foamable chips will result in even greater contrast in texture between valleys and high points in the surface of the finished material. In any event, coverage of the sheet with non-foamable or foamable chips may vary considerably, but .. . .

, 1060;282 typically involves between about 10% and about 80% coverage if a foamable undercoat is not used and the only foaming effect is provided by the foamable chips.

This Example illustrates a suitable method of preparing a product such as that depicted in Figure 1(b). In this Example the base material may be a 32 mil thick sheet of asbestos felt onto which is doctored a latex size coating which acts as a barrier against plasticizer migration and improves adhesion of the vinyl layer, which is next applied. A clear plastic vinyl adhesive coat is then applied to the latex coated felt. This adhe-sive layer has the following compositionO
Parts by Weight PVC homopolymer dispersion resin50.0 PVC homopolymer suspension resin50.0 Dihexyl Phthalate 50.6 ~onylphenoxy poly (ethyleneoxy)ethanol oO6 This adhesive layer may be applied with a reverse roll coater at a thick-ness between 10 and 25 milsO Chips having the following composition are used in this example. -Parts by Weight ;~
PVC homopolymer dispersion resin 50 PVC homopolymer suspension resin 50 Epoxydized Soya Oil 6.o Dihexyl Phthalate 58.0 Zinc-Cadmium catalyst 2.5 Titanium dioxide 7.5 ABF~ 205 The above chips are formed in sheets as described above in a thickness of 10 to 15 mils and are broken up into pieces averaging about 1/16 of an inch --1~

106~ 2 diameter. These chips are sprinkled onto the adhesive plastic layer in amounts of about o.6 lb. Per square foot of adhesive layer surface area yielding a coverage of about 80% of such area with foamable chips. The sheet is then subjected to a temperature of about 325F for about 30 seconds in an oven to gel the adhesive layer containing the chips and the gelled layer is pressed against the chrome drum heated to 300 F while still hot to further embed the chips in the layer of plastic and smooth the surface thereof. The gelled, smoothed sheet is then printed with a suitable design via conventional printing techniques and is then covered with a topcoat 10 or wear layer of the same formulation as the adhesive layer to a thickness of 10 to 15 mils. The sheet is then subjected to a temperature of 370F
for a period of 3 minutes to completely cure the PVC and foam the embedded foamable chips by decomposing the blowing agent. The resultant product has a clear wear layer with a minimum thickness of 10 mils and a textured surface with a height variation of 15 mils between the valleys and pro-tuberances of its surface. If one or more inks are used containing a chem-ical suppressant, the areas printed with such inks will be emboised in reg-ister. Alternatively, as mentioned above the invention alsP contemplates the use of other conventional chemical and mechanical embossing techniques 20 to supplement the textured appearance obtained by the practice of the invention.
If desired, foamable chips may be mixed with non-foamable chips in practicing the invention. The use of a mixture of non-foamable chips and foamable chips will result in even greater contrast in texture between val-leys and high points in the surface of the finished material. In any event, coverage of the sheet with non-foamable may vary considerably, but typically involves between 10% and 80% coverage.

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This example illustrates a suitable method of preparing a product --1~ , :

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such as that depicted in Figure 3b. In this example the base material may be a 32 mil thick sheet of asbestos felt onto which is doctored a latex size coating which acts as a barrier against plasticizer migration and improves adhesion of the vinyl layer, which is next applied. A foamable plastic vinyl adhesive coat is then applied to the latex coated felt using a knife coater to obtain a 15 mil thick layer. This adhesive layer has the following composition.
Parts by Weight PVC Homopolymer Dispersion Resin 50.0 PVC Homopolymer Suspension Resin 5000 Epoxidized Soya Oil 6.0 Dihexyl Phthalate Plasticizer 58.0 Zinc catalyst 2.5 Ti2 705 ABFA Blowing Agent 2.5 A mixture of plain and suppressant chips (chips containing blowing suppressant) may be used. Plain chips made from the following composition are used in this example.
Plain Chips Parts by Wei~ht PVC Homopolymer Dispersion Resin 54.0 PVC Homopolymer Suspension Resin 46.0 Dihexyl Phthalate 32.0 Calcium-Zinc Stabilizer 11.0 Mineral Spirits 3.0 SuppresSantchipsused may have the same composition as the plain chips except for the addition of 5 parts by weight benzotriazole blowing suppressant.
The above chips may be made by forming gelled sheets as described above in a thickness of 10 to 15 mils and then breaking the sheets into 10~)282 pieces averaging about 1/16 of an inch diameter. These chips are sprinkled onto the adhesive plastic layer in the ratio of about 50% plain to 50%
suppressant chips in amounts of about 0.04 lbso per square foot of adhesive layer surface area, yielding a coverage of about 50% of such area with non-foamable chips. The sheet is then subjected to a temperature of about 325 F for about 30 seconds in an oven to gel the adhesive layer containing the chips and the gelled layer is pressed against a chrome drum heated to 300 F while still hot to further embed the chips in the layer of plastic and smooth the surface thereof. The gelled, smoothed sheet is then printed with a suitable design via conventional printing techniques and is then covered to a thickness of tO to 15 mils with a topcoat or wear layer of the following formulation:
Parts by Weight PVC Homopolymer Dispersion Resin 100 `
Dihexyl Phthalate 56 Light Stabilizer 5 -Epoxidized Soya Oil 6 Mineral Spirits 3 Alkylphenylether of Polyethylene Glycol oO6 The sheet is then subjected to a temperature of 370 F for a period of 2 3/4 minutes to completely cure the PVC and foam the foamable layer by decomposing the blowing agent thereinO The resultant product has a clear wear layer with a minimum thickness of 10 mils and a textured surface with a height variation of 15 milsO

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A process for making a decorative sheet-type covering material having a textured surface characterized by (a) forming a layer of wet non-foamable plastic on a substrate, said layer having foamable chips containing blowing agent embedded therein; and (b) heating said layer to a temperature sufficient to cure same and decompose said blowing agent, thereby foaming said chips and imparting a textured surface to the material, the textured surface having a height variation due to the chips of at least 4 mils.

2. A process for making decorative sheet-type covering material having a textured surface which comprises:
(a) forming a foamable plastic layer on a substrate, said layer containing blowing agent and having non-foamable chips embedded therein; and (b) heating said layer to a temperature sufficient to cure same and decompose said blowing agent, thereby foaming said layer and imparting a textured surface to the material due to the effect of the non-foamable chips, said textured surface having a height variation due to the chips of at least 4 mils.

3. The process according to claim 2 in which at least a portion of the chips contain blowing suppressant.

4. The process according to any one of claims 1 to 3 in which the layer is formed of PVC plastisol or organosol.

5. The process according to claim 1 or claim 2 in which the layer is formed by coating the substrate with wet plastisol or organosol and then embedding the chips in the plastisol or organosol.

6. The process according to claim 1 or 2 in which the layer is formed by first mixing the chips with the organosol or plastisol and then applying the resulting mixture to the substrate.

7. The process according to claim 1 or 2 in which the chips comprise a gelled plasticized vinyl composition.

8. The process according to claim 1 in which, prior to step (b) of claim 1 the layer of step (a) is gelled and a clear wear layer is applied over the layer of step (a), said wear layer comprising a layer of polyure-thane or a layer of PVC plastisol or organosol and said wear layer being cured during step (b) of claim 1.

9. The process according to claim 1 or 2 in which the substrate comprises felt coated with latex.

10. The process according to claim 8 in which printing is applied to the layer of step (a) after said layer is gelled and before application of the clear wear layer.

11. The process according to claim 1 in which the layer containing embedded foamable chips also contains non-foamable chips.

12. The process according to claim 2 in which the foamable layer having embedded chips containing blowing suppressant also contains chips not containing blowing suppressant.

13. The process according to claim 1 in which the substrate includes a gelled layer of PVC plastisol or organosol containing blowing agent, the blowing agent being decomposed in step (b) to form a foamed, cured layer under the cured layer containing the foamed chips.

14. The process according to claim 8 in which the cured wear layer has a minimum thickness of at least about 4 mils.

15. A decorative sheet-type covering material having a textured surface and comprising:
(a) a substrate;
(b) a non-foamable plastic layer comprising cured PVC plastisol or organosol, said plastic layer having foamed chips comprising gelled, plasticized vinyl composition embedded therein; and (c) a cured, textured wear layer comprising polyurethane or cured PVC plastisol or organosol over said plastic layer, said wear layer being a minimum of about 4 mils thick and the surface of the wear layer having a height variation due to the foamed chips of at least 4 mils.

16. Decorative sheet-type covering material having a textured surface and comprising:
(a) a substrate;
(b) a cured, foamed plastic layer adhered to said substrate, said plastic layer having non-foamable chips embedded therein; and (c) a clear, cured, textured plastic wear layer over said foamed plastic layer, said wear layer having depressions in the surface thereof corresponding to the location of the non-foamable chips within the foamed plastic layer and said wear layer having a minimum thickness of about 4 mils and a height variation of at least 4 mils due to the presence of the chips.

17. The material of claim 16 in which the plastic layer adhered to the substrate comprises cured PVC plastisol or organosol and the wear layer comprises polyurethane or cured PVC plastisol or organosol.

18. The material according to claim 17, in which the chips comprise gelled plasticized vinyl composition.

19. The material according to claim 15 in which at least a portion of the chips contain blowing suppressant.

20. The material according to claim 19 in which the chips are complete-ly embedded in the plastic layer.

21. The material according to claim 19 including printing applied to the plastic layer containing the embedded chips under the wear layer.

22. The material according to claim 19 including a layer of foamed PVC

plastisol or organosol between the coated substrate and the plastic layer containing the foamed chips.

23. The material according to claim 15 in which the plastic layer containing the foamed chips also contains unfoamed chips.

24. The material according to claim 16 in which the foamed plastic layer adhered to the substrate comprises cured PVC plastisol or organosol and the wear layer comprises, polyurethane or cured PVC plastisol or organosol.

25. The material according to claim 24 in which the chips comprise gelled plasticized vinyl composition.

26. The material according to claim 16 in which the chips are completely embedded in the foamed layer.

27. The material according to claim 24 including printing applied to the layer containing the embedded chips under the wear layer.

28. The material according to claim 16 in which the foamed layer also contains chips not having blowing suppressant contained therein.

29. Material according to claim 24 in which at least a portion of the chips contain blowing suppressant.

30. The material according to any one of claims 15 to 17 in which the substrate comprises felt coated with latex.