Method for finishing leather and leather substitutes

Abstract

A process for finishing leather and leather-like material which comprises applying a foamable latex to low grade leather and leather substitutes, drying and foaming the latex coated substrate, crushing the foam coating then treating the crushed foam coated low grade leather or leather-like material with a finish coat which results in the preparation of leather and leather substitutes having improved properties over leather and leather substitutes coated in the conventional manner.

Description

This invention relates to a novel process for finishing leather splits, low grade corrected and full grain leathers, non-woven webs and other artifical webs applicable to manufacture of synthetic leathers especially for shoe upper end use, pigskins, sheepskins, and other leather-like materials which yields a finished product possessing the aesthetics required by the leather trade while dramatically reducing the number of steps required in achieving the finished product. In addition, the resulting product maintains or improves the properties required of a leather or leather-like material used in the manufacture of shoes, purses, garments, belts, upholstery, wallets and the like; namely, flexibility, abrasion resistance, adhesion, water vapor permeability, scuff resistance, hand or temper, and leather-like aesthetics, a balance of properties not obtainable, coating by other available procedures.

This invention is especially applicable to finishing leather and leather substitutes which possess irregular surface defects or which have an initial appearance that does not resemble a piece of finished leather because this process introduces a uniform artifical leather-like grain surface to the substrate in question.

In the art of finishing leather and leather substitutes means for upgrading low grade or damaged materials are still being sought. Also, the search continues for attractive low cost alternatives to the microporous urethane laminate presently used to surface the essentially nonwoven base web of poromeric materials.

Textile fabrics have been successfully coated with polymeric compositions or formable polymeric compositions which foam on the textile (U.S. Pat. No. 3,527,654). This procedure has not been successfully adaptable to the nonwoven substrates, such as the leather finishing arts, because of the balance of properties required for leather and leather substitutes which is different and more difficult to achieve than with conventional textile fabrics.

It has been found that the properties of the crushed foam coated grain side or flesh side of leather splits, when prepared according to the teachings of this invention, are superior in appearance to those prepared by conventional techniques. The softness of hand of the leather and leather substitutes prepared by this invention is greatly improved over material which has been treated with conventional finishes. By this process, outstanding hiding is assured by a one coat application whereas in conventional techniques the application of one coat would usually not provide adequate masking of the imperfections or details on the substrate.

In addition, this process eliminates many steps of the conventional processes providing an economical process for upgrading leather and leather substitutes. Still another advantage is the controlled build-up of the coating which eliminates "photographing" of the underlying substrate.

By the instant process one is able to utilize in addition to ordinary leather substitutes poor quality leather which previously was not considered suitable for finishing. Leather which contains pronounced hair follicles or other undesirable skin features such as brand marks, scars, tick marks and the like may now be converted by this invention into useable and desirable material. For example, tanned pig skin can be coated by the instant process to provide an excellent finished leather. This process is especially applicable to leather splits. By this process, leather splits achieve a higher level of aesthetics and physical performance than is currently possible with conventional split finishing techniques.

This process also eliminates the necessity for impregnating the leather substrate, though we have found that in certain situations a better product may be obtained when impregnating is done.

The overall properties of the system are controlled by the properties of the foamable latex which allows one to obtain a soft, flexible, water vapor permeable coat and together with a finish coat of a durable resin system one obtains the desired abrasion and scuff resistance properties without detracting from the flexibility and water vapor permeability characteristic of the latex grain layer which has been introduced as the foam coat. Both the foam coat and finish coat determine the ultimate properties and performance of the system.

This invention also embraces the coating of leather substitutes to afford material rivalling that of high grade leather. The term "leather substitutes" is as defined in U.S. Pat. Nos. 3,537,883; 3,100,721 and 3,000,757.

A crushed foam coating means a coating which after obtaining a cellular structure is compressed by crushing or embossing.

This invention provides a novel process for preparing finished leather and finished leather substitutes which comprises treating various substrates including grain leather, upper leather, leather splits, reconstituted leather, leather substitutes, non-woven webs possessing extensibility and recovery, resilency and other properties resembling leather and the like in the following manner:

a. applying a coating of polymeric latex, containing a blowing agent, to leather or leather substitutes which coating is foamed on the substrates by a blowing agent selected from

1. a solvent having a boiling point in the range of from about -50.degree.F. to about 220.degree.F. in which the uncrosslinked polymer exhibits a swell ratio in the range of from 1 to about 7 or

2. a chemical blowing agent;

b. drying and foaming the latex coated substrate at a temperature in the range of from about 120.degree. to about 400.degree.F.;

c. crushing, embossing and curing the coated substrate at a pressure in the range of from about 5 to about 2500 psi at a temperature in the range of from about 150.degree. to about 400.degree.F., and

d. applying a finish coat to the crushed foam coated substrate.

A preferred embodiment of the invention comprises:

a. applying a coating of a polymeric latex which coating is foamed on the substrate by the use of a blowing agent selected from

1. a solvent having a boiling point in the range of from about 75.degree. to about 220.degree.F. and in which the uncrosslinked polymer exhibits a swell ratio in the range of from 1 to about 7 or

2. ammonium bicarbonate;

b. drying and foaming the latex coated substrate at a temperature in the range of from about 150.degree. to about 390.degree.F.;

c. crushing, embossing and curing the foam coated substrate at a pressure in the range of from about 5 to about 2500 psi at a temperature in the range of from about 150.degree. to 325.degree.F., and

d. applying a finish coat to the crushed foam coated substrate wherein the finish coat is selected from compositions containing melamine resins, urea-formaldehyde condensates, nitrocellulose, urethanes, polyvinyl chlorides, acrylics, cellulose acetate butyrates, nitrocellulose, modified urethanes or mixtures thereof.

Due to the inherent differences between leather and leather substitutes, there is a slight variation in the preferred method for finishing these particular substrates. For example, when leather such a full grain leather, leather splits or reconstituted leather is the desired substrate, the preferred method comprises:

a. spraying a coating of a polymeric latex on the leather which coating is foamed on the leather by a solvent blowing agent having a boiling point in the range of from about 75.degree. to about 220.degree.F., in which the uncrosslinked polymer exhibits a swell ratio in the range of from about 1 to about 6;

b. drying and foaming the latex coated leather at a temperature in the range of from about 180.degree. to about 325.degree.F.;

c. crushing, embossing and curing the foam coated leather at a pressure in the range of from about 15 to 1200 psi at a temperature generally in the range of from about 150.degree. to 300.degree.F. but preferably at a temperature in the range of 180.degree. to about 270.degree.F., and

d. applying to the crushed foam coated leather a finish coat composition containing nitrocellulose and an isocyanate terminated prepolymer of an organic polyisocyanate with a polyester or polyether polyol or cellulose acetate butyrate.

When it is desired to coat a leather substitute, the following is the preferred method and comprises:

a. spraying a coating of the polymeric latex on a leather substitute which coating is foamed on the leather substitute by a solvent blowing agent having a boiling point in the range of from about 75.degree. to about 220.degree.F. in which the uncrosslinked polymer exhibits a swell ratio in the range of from 1 to about 6;

b. drying the foam coated leather substitute at a temperature in the range of from about 120.degree. to about 4002 F.;

c. crushing, embossing and curing the crushed foam coated leather substitute at a pressure in the range of from about 5 to about 2500 psi and, preferably, at a pressure in the range of from about 50 to 1000 psi at a temperature in the range of from about 150.degree. to about 400.degree.F., and, preferably, at a temperature in the range of from about 275.degree. to about 325.degree.F., and

d. applying to the crushed foam coated leather substitute a finish coat composition containing nitrocellulose and an isocyanate terminated prepolymer of an organic polyisocyanate with polyester or polyether polyol or cellulose acetate butyrate.

The use of lower pressures and higher temperatures is preferred for the leather substitutes since it will result in better adhesion of the coating to the substrate. Many of the synthetic and artificial leather-like materials are not as demanding of temperature and can be produced at lower temperatures and pressures.

These temperatures and pressures apply to embossing with a flat hydraulic or mechanical press where time in contact with the bed is easily determined. For embossing with rotary embossing equipment actual time that the material is in contact with the roll and contact pressure are more difficult to define. Some deviations from those conditions including temperature of embossing therefore would be expected. The times for conducting the crushing, embossing and curing will usually vary from 0.5 to 10 seconds. For leather, the time period is preferably from about 2 to about 6 seconds. For the leather substitutes, the preferred times are from 0.5 to 2 seconds.

Crushed foam coating as currently practiced in the textile industry uses mechanically generated foam which is knifed onto a continuous roll of fabric. Knife coating is an unacceptable technique for finishing leather as it results in excessive wastage of the coating material also an even coating cannot be applied to leather which leather is often of nonuniform thickness. Mechanically generated foam can be applied by spray, but collapse of the foam during spraying, and the high volumetric throughput of low density foam required to achieve reasonable coating add-ons makes this a decidely unattractive prospect. Spray application of the unfoamed mixture provides inadequate surface coverage and hiding.

Depending upon volatility of the blowing agent, foaming can be made to occur as the coating emerges from the spray gun since it is possible to employ solvent blowing agents with a boiling point below ambient temperatures or upon oven drying of the coated substrate. Since the coating penetration will generally give better adhesion but stiffer temper, control over the final properties of the coating is now possible through selection of blowing agents having the required characteristics disclosed below.

It is known to generate a stable cellular foam structure from a latex acrylic copolymer. (See for example U.S. Pat. No. 3,640,916). However, it has been found that knowing only the volatility of the solvent is insufficient to control the quality and structure of the foam. Consideration must also be given to the interaction of the solvent with the polymer since there is a direct relationship between the swell ratio and solvent available for foaming the polymer. By employing solvents for which the swell ratio falls within the specified swell ratio requirement, it is now possible to consistently duplicate the desired foaming. If the solvent is dissolved in the polymer, it may no longer be available to foam the latex.

Conceivably, the solvent might be able to foam the polymer if it were still in the polymer after the water has been driven off and more heat is applied. There is a distinction between foaming the latex and foaming the polymer. The process of generating a cellular structure by internal gas or vapor generation in a continuous polymer phase is quite different and will possess different requirements from generating a foam from a latex where the continuous (water) phase is the expanded structure which must be stabilized as a cellular network by having latex particles on the surface of the bubbles form films or struts which remain after the continuous phase has evaporated.

It has been found that solvents falling within a narrow range of swell ratio afford products having an even coating of crushed foam and which, when crushed, is able to mask any undesirable defects. The swell ratio is defined as the volume of the swollen polymer network in a given solvent divided by the volume of the polymer sample before solvent treatment. These numbers can be readily obtained in the laboratory by numerous methods with the most expeditious being a gravimetric procedure by which the polymer is weighed before and after equilibrium treatment with the solvents in question and then by using the appropriate densities of the polymer and solvent the volumetric swell ratio can be ascertained. Examples of these solvents include dichlorodifluoromethane, carbon tetrafluoride, trichlorotrifluoroethane, pentane, hexane, cyclohexane, trichlorofluoromethane, monochlorotrifluoromethane, monobromotrifluoromethane, monochlorodifluoromethane, octafluorocyclobutane and isomers thereof.

The amount of blowing agent solvent employed may vary from about 3 to about 20 percent by weight of the total weight of the formulation. In general, the solvent chosen is from about 7 to 12 percent by weight of the weight of the formulation.

In addition to the employment of solvents as blowing agents, there may also be employed chemical blowing agents including the organic and inorganic chemical blowing agents. Examples of the organic chemical blowing agents include azo compounds such as azobisformamide, azobisisobutyronitrile, diazoaminobenzene and the like, N-nitroso compounds, such as N,N'-dimethyl-N,N'-dinitrosoterephthalamide, N,N'-dinitrosopentamethylenetetramine and the like and sulfonyl hydrazides such as benzenesulfonylhydrazide, p-toluenesulfonylhydrazide, 4,4'-oxybis(benzenesulfonylhydrazide) and the like. Examples of the inorganic chemical blowing agents include ammonium bicarbonate, sodium bicarbonate, sodium carbonate, hydrogen peroxide, ammonium nitrate, malonic acid and the like with ammonium bicarbonate being the preferred chemical blowing agent.

The quantity of foam applied will depend on the nature of the substrate and the type of print desired. A 15-30 gm./sq. ft. wet add-on would be recommended for a finely buffed impregnated split using a hair cell print since impregnation helps to seal the surface and hold out the foam system. A 30-60 gm./sq. ft. wet add-on might be required on an unimpregnated nappy split with a deep lizard print. Add-ons in the 60 gm. range should be generally avoided except for exceptionally deep prints. The above wet add-ons are predicated on the foam being applied from a formulation containing about 50-55% polymer and will vary with polymer content.

The drying step is conducted at a temperature in the range of from about 120.degree. to about 400.degree.F. Some crosslinking occurs during this step and it is necessary to prevent a large amount of cross-linking which, if it occurred at this stage would interfere with embossibility. Generally, drying temperature and time are determined by varying one then the other until the desired properties are obtained.

The drying time is dependent on many factors but in general dwell time in an oven ranges from 2 to 8 minutes. The major concern in drying is to control the drying conditions to avoid excessive skinning of the foam which yields poorer results, and also necessitates longer drying times since it insulates and seals off the wet foam underneath. The important variables which play a role in drying are temperature, residence time, add-on of foam and airflow in the oven. The airflow in the oven is an important variable which can be regulated by adjusting the baffles in most ovens and in certain ovens by variation of the blower speed. It is recommended that high air velocities, while beneficial for rapid drying, do not impinge directly on the foam because this can lead to severe turbulence and skinning problems. The exact degree of drying is determined subjectively. It should be dry enough so that when one runs his finger along the foam, it does not feel "squishy" and not too dry so that the material fails to accept a good print pattern. Laboratory data indicate that a large latitude in drying time is available between under drying and over-drying. For example, if 3 minutes is judged as the best drying time for a specific piece of equipment, 1.5 minutes would probably yield an acceptable result with the only deficiency being somewhat poorer release from the plate after embossing, while a 5 minute drying interval would probably show only a slight decrease in print definition but would otherwise yield acceptable results. Print definition is exceedingly important for without it the finish will not have the authentic appearance of leather.

The next step comprises the single step of crushing, embossing and curing the foam coated substrate. By subjecting the foamed coated substrate to a pressure in the range of from about 5 to about 2500 psi and preferably at a pressure in the range of 15 to 1200 psi at a temperature in the range of from about 150.degree. to about 400.degree.F. and preferably, at a temperature in the range of 150.degree.to 325.degree.F. The necessity for carrying out separate crushing, embossing and curing process steps has been eliminated.

After the drying step, the coated substrate may be subjected to some minimal pressure (e.g. 5 psi) if it is necessary to handle the coated substrates. At this point in the process, the coating is slightly tacky and may delaminate if the coating is brought into contact with some other material; or piled face to face with other foam coated substrates; however, even minimal pressure will assure sufficient adhesion of the coatings.

The final step in the process for preparing the finished leather and finished leather substitutes comprises applying to the crushed foam coated leather substitutes a finish coat composition which is extensible and flexible containing one of the following ingredients: nitrocellulose, urethanes, polyvinyl chlorides, acrylics, cellulose acetate butyrates or a composition containing nitrocellulose and an isocyanate terminated prepolymer of an organic polyisocyanate with a polyester or polyether polyol or mixtures thereof with or without plasticizers. The preferred finish coats are the coating compositions which contain nitrocellulose and an isocyanate terminated prepolymer of an organic polyisocyanate with a polyester or polyether polyol or contain cellulose acetate butyrate. These preferred coating compositions provide finish coats on leather and leather substitutes which have better flexibility and better wear properties than those previously obtainable by using other finishes. The cellulose acetate butyrates are described in U.S. Pat. No. 3,574,154 which is hereby incorporated by reference.

The amount of nitrocellulose present in one of the preferred compositions is preferably in the range of from about 15% to about 55% based on the total solids of the composition. These preferred coating compositions are further described in the U.S. patent application Ser. No. 161,987, now U.S. Pat. No. 3,763,061 which application is hereby incorporated by reference. The finish coat should be applied so that there is approximately 1.0 gm. of solid top coat per sq. ft. of substrate in order to yield the best balance of physical properties in terms of flexibility and abrasion resistance. The finish coat add-on can be controlled by the solids of the formulation, machine settings, conveyor speeds and the number of coats applied. The top coat should be formulated at a urethane/nitrocellulose ratio of 55/45 to give the best balance of properties in terms of flex, abrasion resistance and tack. This urethane/nitrocellulose ratio can be varied if necessary from 50/50 to 65/35 to obtain a particular result on a specific leather but if changes are made, flex, abrasion resistance and tack should be followed. Generally, the latex coatings employed in this invention should contain a latex polymer, clay, titanium dioxide or other inert fillers and a foam stabilizer and may contain an additive for crosslinking the polymer.

The latex compositions that produce the foams used in the present invention are prepared from at least two of the following monomers of which at least one is a monomer which contains functional groups capable of crosslinking:

a. an .alpha.,.beta.-ethylenically unsaturated acid which includes acrylic acid, methacrylic acid, ethacrylic acid, itaconic acid, aconitic acid, crotonic acid, citraconic acid, maleic acid, fumaric acid, .alpha.-chloroacrylic acid, cinnamic acid, mesaconic acid, and the like. Mixtures of these acids can also be used;

b. a monomer of the formula ##EQU1## wherein R is hydrogen or alkyl, for example, lower alkyl of from 1-4 carbon atoms and R.sup.1 is a straight, branched or cyclic chain alkyl, alkoxyalkyl or alkylthioalkyl radical having from 1 to 20 carbon atoms, or cycloalkyl having from 5-6 carbon atoms, such as methyl, ethyl, propyl, n-butyl, 2-ethylhexyl, heptyl, hexyl, octyl, 2-methylbutyl, 1-methylbutyl, butoxybutyl, 2-methylpentyl, methoxymethyl, ethoxyethyl, cyclopentyl, cyclohexyl, isobutyl, ethylthioethyl, methylthioethyl, ethylthiopropyl, 6-methylnonyl, decyl, dodecyl, tetradecyl, pentadecyl and the like; R.sup.1 is also ureido, hydroxy lower alkyl of from 1 to 5 carbon atoms such as hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, hydroxypentyl, and the like; 2,3-epoxypropyl, amino lower alkyl or mono- or di- lower alkyl or hydroxy lower alkyl substituted amino lower alkyl;

c. a monomer of the formula ##EQU2## wherein R.sup.2 is hydrogen or methyl and R.sup.3 is halo such as chloro and the like; lower alkanoyloxy such as acetoxy and the like, cyano, formyl, phenyl, carbamoyl, N-hydroxymethyl, tolyl, methoxylethyl, 2,4-diamino-s-triazinyl lower alkyl, and epoxy;

d. ##EQU3## wherein R.sup.4 is hydrogen or methyl; R.sup.5 and R.sup.6 are lower alkoxy such as methoxy, ethoxy and the like or lower alkanoyloxy such as acetoxy and the like.

Examples of the specific monomers described in subparagraphs (b) and (c) and (d) which may be employed are: methyl methacrylate, ethylmethacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, pentyl methacrylate, isopentyl methacrylate, tert-pentyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, 2-ethylbutyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, decyl methacrylate, lauryl methacrylate, myristyl methacrylate, cetyl methacrylate, stearyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate, amyl acrylate, isoamyl acrylate, tert-amyl acrylate, hexyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, vinyl acetate, tetradecyl acrylate, acrylamide, pentadecyl acrylate, styrene, pentadecyl methacrylate, vinyl toluene, methacrylamide, N-methylolacrylamide and the like, glycidyl methacrylate, methylaminoethyl methacrylate, tert-butylaminoethyl methacrylate, 6-(3-butenyl)-2,4-diamino-s-triazine, hydroxypropyl methacrylate, hydroxyethyl methacrylate, methacrylonitrile, methoxymethyl methacrylamide, N-methylol methacrylamide, acrolein, methacrolein, 3,4-epoxy-1-butene, acrolein diethyl acetal, acrolein dimethyl acetal, allylidene diacetate, methallylidene diacetate, the analogs of the above methacrylic acid derivatives with other unsaturated acids such as acrylic acid and itaconic acid, such acids themselves, dicarboxylic acids such as maleic acid and half esters and half amides thereof, vinyl ethers of glycols such as ethylene glycol are also included.

As may be seen, the crosslinkable addition polymerizable unsaturated monomers have reactive polar groups selected from ##EQU4## Such groups may be included as are mutually or self-crosslinkable, or separate crosslinking compounds such as triazineformaldehyde resin may be added.

Of course, water-sensitive materials such as isocyanates should not be used in aqueous systems unless they are blocked by reaction with a phenol group which protects the isocyanate groups until subsequent heating or the use of other reaction mechanisms such as the use of calcium, zinc, or tin compound catalyst conventional in the art.

The preferred emulsion copolymers have a molecular weight of between about 70,000 and 2,000,000 and preferably between about 250,000 and 1,000,000 and are made by the emulsion copolymerization of the several monomers in the proper proportions. Conventional emulsion polymerization techniques are described in U.S. Pat. Nos. 2,754,280 and 2,795,654. Thus, the monomers may be emulsified with an anionic, a cationic, or a nonionic dispersing agent, about 0.05 to 10 percent thereof ordinarily being used on the weight of the total monomers. The acid monomer and many of the other functional or polar monomers may be soluble in water so that the dispersing agent serves to emulsify the other monomer or monomers. A polymerization initiator of the free-radical type, such as ammonium or potassium persulfate, may be used alone or in conjunction with an accelerator, such as potassium metabisulfite, or sodium thiosulfate. Organic peroxides, such as benzoyl peroxide and tert-butyl hydroperoxide are also useful initiators. The initiator and accelerator, commonly referred to as catalyst, may be used in proportions of 0.1 percent to 10 percent each based on the weight of monomers to be copolymerized. The amount, as indicated above, may be adjusted to control the intrinsic viscosity of the polymer. The temperature may be from room temperature to about 240.degree.F.

The following is a list of copolymers which may be employed in this invention: The copolymers have the following monomer compositions: 96EA/3.5AM/0.5AA; 96EA/4MOA, 94EA/5.5 ALAC AC/0.5AA; 94.5EA/5HEMA/0.5AA; 66EA/32.7MMA/1.3MAA; 100EA; 83EA/15MMA/2AA(Na); 83BA/15AN/1AC/1AA; 65EA/25.5BA/4.5AN/3.5AM/1.51A; 86EA/10AN/4MOA; 83BA/14AN/1Ac/2AA; 97EA/1Ac/2AA; 68BA/28MMA/2Ac/2AN; 30BA/55EA/10MMA/3.5AN/0.5Ac/1AA; 45BA/10AN/40EA/4HEMA/1AA and the like. (The definitions of the abbreviations appear below.)

The use of a water soluble surfactant or a combination or surfactants increases the dispersion of the latex emulsion and acts as a foaming aid and foam stabilizer.

These surfactants include the alkali metal, ammonium or amine salts, such as the mono-, di- or triethanol amines of the aliphatic carboxylic acids having from 16 to 20 carbon atoms including oleic acid, stearic acid and the like; for example, sodium, potassium or ammonium stearate; sodium potassium or ammonium oleate and the like. Other surfactants which may be employed together with those described above include the alkali metal salts of aliphatic or alkylaryl sulfonic acids, such as sodium lauryl sulfate, sodium dodecylbenzene sulfonate and the like as well a nonionic surfactants such as the polyethylene oxide condensates of the alkyl phenols or higher fatty alcohols, for example, tertoctylphenol condensed with from 5 to about 40 ethylene oxide units, lauryl alcohol condensed with from 5 to 50 ethylene oxide units or similarly ethylene oxide condensates of long chain mercaptans, fatty acids, amines and the like.

Although either thermoset or thermoplastic resins may be employed in this process, the preferred resins are the thermoset ones since the foam generated affords leather and leather substitute products more desirable in the manufacture of and subsequent use of the leather and leather like goods.

To crosslink the acrolein or methacrolein containing resins, a dibasic amine, for example, diethylene triamine, hydrazine and the like are employed. The melamine type resins are used to crosslink the polymers containing hydroxy and amino functions. Other crosslinking agents may be employed and said agents are well-known to those skilled in the art.

The finish compositions can be clear or can contain dulling agents, pigments, or dyes depending upon the particular use or aesthetic qualities which are desired. Examples of pigments which can be used include clay, titanium dioxide, calcium carbonate, blanc fixe, finely divided metals such as aluminum and the like, color lakes and tinctorial oxides. Other conventional additives which can be used include fillers, slip agents and lubricants. The finish coat compositions preferably also contains a silicone rubber polymer, for example, those sold by Dow Corning and identified as DC-160, FC227, Syl-Off-291 together with a metal organic salt catalyst, for example, dibutyl tin laurate, zinc octoate and the like. These two chemicals further improve abrasion resistance and tactile aesthetics.

The finish coat compositions can be applied to the crushed foam coated substrates by any of the techniques wellknown in the art, including brushing, swabbing, spraying, curtain coating (flow coating), or dip coating. Among the useful techniques are those described in U.S. Pat. Nos. 2,126,321 and 2,884,340. One or more coats can be applied as desired. The thickness of the coating can be varied depending on the particular purposes that the coating is to serve. The amount of the finish coat applied varies according to the type of material being coated and the ultimate finish desired. Generally, the finish coat is applied so as to provide a deposit of from about 0.1 to about 8 mils dry film thickness and, preferably, from about 0.3 to about 0.5 mils dry film thickness. After application, the coating can be cured by drying to a tack-free state at room temperature for about 30 minutes to one hour, or by heating at a temperature of up to about 100.degree.C. until the desired degree of cure is effected.

An advantage of the nitrocellulose/urethane finish coat is that it forms a coating which has outstanding elastic recovery and flexibility and yet is tough enough to be used as a wear layer when applied to leather or leather substitute in luggage or upholstery, and in garments such as shoes, jackets and the like. These characteristics of flexibility and elastic recovery make the nitrocellulose/urethane finish coat compositions extremely valuable in the coating of thick flexible substrates, and particularly with those substrates having a thickness of from about 30 mils to about 100 mils, which substrates are subjected to severe bending action, for example, in the coating of leather or leather substitute used in luggage, upholstery, shoes and other garments.

Although emulsion polymers are preferred, polymers prepared in organic solutions, e.g., in ethylene glycol, ether, xylene, ethylene glycol monomethyl ether and the like by well-known conventional means such as free-radical initiation with benzoyl peroxide or the like are also useful. Solution polymers useful in the invention preferably have a molecular weight of between 10,000 and 1,000,000.

The formulation of the crushed foam coating is capable of a wide variation. The following table illustrates the components of the formulation which may be employed:

TABLE I ______________________________________ Typical Formulations Parts by Weight ______________________________________ Resin (at 40 to 60% solids) 500-1000 Foam Stabilizer 5-80 Surfactants 0-150 Fillers 25-200 Colorants 0-150 Waxes and other auxiliaries 0-100 Ammonia (28%) 0-15 Dibasic Amines 0-25 Melamine Resins 0-25 ______________________________________

It is to be understood that other ingredients can be incorporated into the foam coating formulation. In particular, fillers, colorants and waxes are added to the formulation in various proportions to afford products having specific desired characteristics. Examples of the types of fillers which may be employed include clays, mica, calcium carbonate, bentonite, silica and the like. Examples of the colorants which may be employed include dyestuffs made from inorganic and organic pigments especially dispersions of the pigment in water with a dispersant and a protective colloid. For example, carbon black, iron oxide pigment, anatase, titanium dioxide and the like. Waxes are employed to aid in the release of the press plate. These waxes are well known to those skilled in the art and include the polyethylene waxes and the like.

The following examples are illustrative of typical formulations which may be employed:

EXAMPLE 1 - Formulation 1 Charge Parts by Weight ______________________________________ Copolymer composed of 83BA/14AN/1Ac/2AA 100 China Clay 15 Ammonium Stearate (33%) 7.0 Diethylenetriamine 0.6 Ammonium Hydroxide (26%) 2.0 Primal Non-Bleeding Red Colorant 15.0 EXAMPLE 2 - Formulation 2 Copolymer composed of 825BA/14AN/1.5Ac/2AA 500.0 Clay 75.0 Ammonium Stearate 35.0 Diethylenetriamine 3.5 Ammonia (28%) 10.0 Primal Brown Colorant 75.0 Water 65.5 EXAMPLE 3 - Formulation 3 Copolymer composed of 86EA/10AN/4MOA 565.5 Clay 75.0 Ammonium Stearate 35.0 Aqueous melamine formaldehyde resin 11.5 Ammonia (28%) 10.0 Primal White 264 Colorant 75.0 EXAMPLE 4 - Formulation 4 Charge Parts by Weight H.sub.2 O 65.5 NH.sub.3 (28%) 10.0 Clay 75.0 Primal Blk. 110 75.0 Copolymer composed of 96EA/3MOA/0.5AA 500.0 Ammonium Stearate 35.0 EXAMPLE 5 - Formulation 5 Primal Blk. 110 75.0 NH.sub.3 (28%) 10.0 Clay 75.0 Copolymer composed of 96EA/3MOA/0.5AA 565.5 Ammonium Stearate 35.0 Aqueous melamine formaldehyde resin 11.5 EXAMPLE 6 - Formulation 6 Primal Ochre Yellow 75.0 NH.sub.3 (28%) 10.0 Clay 75.0 Copolymer composed of 96EA/3MOA/0.5AA 565.0 Ammonium Stearate 35.0 Melamine 11.5 ______________________________________

The components of Examples 1 to 6 are added to the mix in the order given (the NH.sub.3 is split into two feeds; half being saved until after the melamine resin, Aerotex MW, has been added) and stirred thoroughly -- (Lightning mixer, Talboys mixer or Cowles dissolver). Any other melamine resin may be employed such as those sold under the following tradenames: Aerotex M-3, melamine-formaldahyde-methanol, methoxylated melamine formaldehyde. After mixing, the formulated mix is covered to prevent skinning over.

______________________________________ EXAMPLE 7 - Formulation 7 Charge Parts by Weight ______________________________________ Copolymer composed of 83BA/14AN/1Ac/2AA 420.5 Ammonium Stearate 25.8 Octylphenoxy polyethoxy ethanol 21.5 Acme WW Clay 57.5 Primal Black 110 41.7 NH.sub.3 (25%) 7.0 Polyethylene Wax 23.9 Diethylene triamine 2.1 600.0 ______________________________________

The latex and non-ionic surfactants are added to a Cowles dissolver and stirred slowly. To this is added the ammonium stearate. The agitation is increased while slowly adding the remaining ingredients in the order given. After a uniform suspension is obtained, the formulation is filtered through a cheese cloth or mesh screen (40 mesh). This material is now ready to be employed with an appropriate blowing agent. By substituting for the colorant, Primal Black 110, other suitable colorants, other formulations can be prepared in substantially the same manner.

EXAMPLE 8

Spraying from an Aerosol Can

The formulation of Example 3 (70 g.), trichlorofluoromethane (60 g.), and dichlorodifluoromethane (40 g.) are charged to a six ounce aerosol can with a non-breakup nozzle. The can is shaken and the contents sprayed onto (1) leather split and (2) paper. The sprayed material begins to foam upon leaving the nozzle of the spray can since the boiling point of the propellant blowing agent is below that of ambient temperature and foaming of the coating continues on the substrate. After drying, the coating on leather is simultaneously crushed, embossed and cured on a Watson Stillman Press (190.degree.F., 30 tons, 3 seconds). Density of the foam sprayed is approximately 0.007 gms./cubic centimeter.

By employing a charge of 70 g of the formulation of Example 3, trichloromethane (50 g.), dichlorodifluoromethane (50 g.), the foam has a density of approximately 0.012 gm./cubic centimeter after crushing and embossing as above.

EXAMPLE 9

Spraying with Spray Gun

The formulation of Example 7 is mixed with trichlorotrifluoroethane at room temperature. The mixture is placed in a pressure pot (vacuum feed, 60 pounds line pressure, 15 pounds pot pressure). The mixture is sprayed onto leather at approximately 1.3 to 1.5 ounces wet add-on per square foot. The mixture foams slightly at room temperature but upon drying at 280.degree.F. the coating foams up well. Crushing, embossing and curing are accomplished simultaneously on a Watson Stillman Press at 190.degree.F., 30 tons, for 3 seconds.

EXAMPLE 10

Spray Gun

The experiment of Example 9 is repeated using trichlorotrifluoroethane except that the leather split employed is heated for several minutes at 280.degree.F. before applying the coating. The coating when applied to the heated leather immediately foams and continues to foam during drying. Crushing embossing and curing, as in Example 9, affords a leather with an excellent pattern.

EXAMPLE 11

Foaming Properties of Acrylic Emulsion Polymers Using Trichlorotrifluoroethane

The testing of the foaming properties of various acrylic emulsions is conducted by employing a formulation of the following composition: Latex 307.5 g; NH.sub.3 (28%), 5.0 g.; colorant 537.5 g. and trichlorotrifluoroethane 35 g. The formulations are sprayed with pot pressure spray equipment at 15 lbs. pot pressure and 80 lbs. line pressure. The substrate used is a white cardborad paper panel 141/2 inches .times. 111/2 inches. After spraying, the coating is air dried for 1 minute and then dried for five minutes in a forced draft oven at 280.degree.F.

The polymers employed were prepared from the following proportion of monomers:

1. 96EA/3.5AM/0.5AA

2. 96ea/4moa

3. 94ea/5.5alacac/0.5aa

4. 94.5ea/5hema/0.5aa

5. 66ea/32.7mma/1.3maa

6. 100ea

7. 83ea/15mma/2aa(na)

8. 83BA/15AN/1AC/1AA

9. 65ea/25.5ba/4.5an/3.5am/1.5ia

10. 86ea/10an/4moa

11. butadiene rubber (Hycar 1571)

EA = ethylacrylate; BA = butylacrylate; MMA = methylmethacrylate;

AA = acrylic acid, MMA = methacrylic acid; IA = itaconic acid;

HEMA = hydroxyethyl methacrylate; AN = acrylonitrile; AC = acrolein, ALACAC = allyl acetoacetate, MOA = acrylamide/methylol acrylamide (1:1) and AM = acrylamide.

RESULTS __________________________________________________________________________ Foam Add-on Applied Brookfield Polymer Rating (g./sq.ft.) Solids pH Visc. (cps) Hue __________________________________________________________________________ 1 Good -- 44.3 9.4 High Bluish Black 2 Fair-Good 14.4 44.3 9.9 336 Bluish Black 3 Fair-Good 14.4 44.3 8.6 268 Bluish Black 4 Fair-Good 21.6 44.3 9.8 648 Bluish Black 5 Good-Very Good 14.4 43.5 10.1 660 Bluish Black 6 Fair-Good 16.2 44.3 10.0 48 Greenish Cast 7 Fair-Good 10.8 37.5 10.2 1636 Bluish Black 8 Fair-Good 12.1 44.3 9.7 88 Green 9 Good 14.0 44.3 9.7 11300 Green 10 Good 19.8 44.3 9.4 860 Bluish 11 Very Good 8.5 38.3 10.1 40 Bluish Black __________________________________________________________________________

EXAMPLE 12

Evaluation of Solvent Blowing Agents

A variety of solvent blowing agents were evaluated using an acrylic polymer of the composition 96 ethyl acrylate/3.5 acrylamide/0.5 acrylic acid (87.8 parts by weight) with the colorant Primal Black 110 (10.7 parts by weight) and ammonia (28%; 1.5 parts by weight). The formulation was sprayed on posterboard and dried at 280.degree.F. for 5 minutes. The quality of the foam, and the swell ratio for the particular solvent employed is as follows:

% of Solvent b.p. in 100 Pts. Swell Solvent .degree.C. Formulation Foam Ratio ______________________________________ 1. CH.sub.2 Cl.sub.2 39.7 5% No Foam 19.61 CH.sub.2 Cl.sub.2 39.7 10% No Foam 19.61 2. CHCl.sub.3 62.1 5% No Foam 44.74 CHCl.sub.3 62.1 10% Slight Foam 44.74 3. CCl.sub.3 CF.sub.3 47.3 5% Uniform Foam 2.53 CCl.sub.3 CF.sub.3 47.3 10% Uniform Foam 2.53 4. CCl.sub.3 F 23.8 5% Uniform Foam 5.57 CCl.sub.3 F 23.8 10% Uniform Foam 5.57 5. Pentane 36.1 5% Uniform Foam 1.21 Pentane 36.1 10% Uniform Foam 1.21 6. Hexane 68.7 5% Uniform Foam 1.07 Hexane 68.7 10% Uniform Foam 1.07 ______________________________________

EXAMPLE 13

Finish Coat and Application Step A -- Preparation of Prepolymer

To a two liter, three-necked flask fitted with a mechanical stirrer, thermometer, distillation head, condenser, nitrogen bleed valve and vacuum source is charged 500.5 g. of a poly ether triol (MW = 1540). The pressure is reduced to 51 mm. of Hg and the temperature raised to 70.degree.C. while agitating the mixture. The distillate, 45.5 g., is collected and the temperature reduced to 30.degree.C. while the pressure is brought to 760 mm. of Hg with a nitrogen bleed. Three hundred and five grams toluene dissocyanate are added to the reaction mixture and the temperature is raised to 75.degree.C. for 16 hours. The isocyanate content is determined and the product cooled to room temperature. The prepolymer has the following properties:

% Solids -- 74.21; Meq. NCO/g. solution -- 0.834; G. H., Viscosity -- T+; Residual TDI -- 1.17.

Step B

Preparation of Finish Coat Composition

The finish coat composition is prepared by mixing the following ingredients (parts by weight); prepolymer of Step A (110), nitrocellulose (177), nitrocellulose plus a dulling agent (100), black pigment, plasticizer and nitrocellulose (200), butyl acetate, xylene and 2-ethoxyethyl acetate (413 parts in a ratio of 50:40:10), a silicone rubber polymer (25, "Dow Corning - 160") and dibutyl tin laurate (50).

Step C

Application

The composition of Step B is applied to the leather or leather-substitute using standard spray equipment such that about 1.0 g. of solids per square foot of substrate is obtained.

By substituting other prepolymers for the prepolymers employed in Example 12, Step B, by substituting other pigments or dyes for the black pigment employed other pigments and by employing other silicone rubber and prepolymers and catalysts other similar finish coat compositions can be prepared.

EXAMPLE 14

Finish Coat and Application of Cellulose Acetate Butyrates

Step A

97.5 parts poly(1,3-butylene adipate) obtained by a conventional process, having a molecular weight of 5,000 and a hydroxy number of 20, is thoroughly dehydrated by sparging with nitrogen at 130.degree. to 140.degree.C. The polyester is then cooled to 106.degree. to 108.degree.C. and 4.6 parts of methylene-bis(4-phenylisocyanate) is added over a period of 15 minutes. The temperature of the reaction mixture is raised to 110.degree. to 115.degree.C. and mixing is continued under a positive pressure of nitrogen for 30 hours. The cooled product has a viscosity of about one million poises and is a light-colored stiff gum. A 50% solution in xylene has a Gardner Holdt viscosity of Z.sub.6.

Step B

Formulation of Clear Plasticized Cellulose Acetate Butryate Solution

A solvent mixture is prepared by blending 510 parts of toluene, 170 parts of methyl ethyl ketone, and 320 parts ethyl alcohol. To 69 parts of this solvent mixture are added 15.1 parts of 3-second viscosity cellulose acetate butyrate comprising 20% butyryl and 25% acetyl content followed by 3.8 parts of a linear polyester, namely, propylene glycol sebacate having a molecular weight of 8,000 and 12.1 parts of a 50 percent solution in xylene of the extended polyester of Example A. The mixture is agitated until a homogeneous solution is obtained. The mixture is pale straw colored and has a viscosity of 2,100 centipoises.

Step C

Application

Twenty parts of the clear finish of Step B is mixed with 80 parts of methyl ethyl ketone and 1 part of a red spirit-soluble dye is added. This mixture is applied by spray-coating to a piece of crushed foam coated leather substitute at the rate of 1.0 g. solids per square foot of leather substitute. The finish is air dried and then embossed at 20 psi and 320.degree.F. for 60 seconds with a sandblasted platen. The resulting finish has a warm brown color and possesses outstanding resistance to cracking or dulling when flexed.

One skilled in the art will apppreciate that the process described above is merely illustrative and is capable of a wide variation and modification without departing from the spirit of this invention.

Claims

What is claimed:

1. A process for preparing finished leather and leather substitutes which comprises:

a. Applying a coating of a polymeric acrylic latex containing a blowing agent, to leather or leather substitutes which coating is foamed on the substrates by said blowing agent selected from, 1) a solvent having a boiling point in the range of from -50.degree. to 220.degree.F. in which the uncrosslinked polymer exhibits a swell ratio in the range from 1 to about 7 or 2) a chemical blowing agent;

b. Drying and foaming the latex coated substrate at a temperature in the range of from about 120.degree. to about 400.degree.F.;

c. Crushing, embossing and curing the coated substrate at a pressure in the range of from about 5 to about 2500 psi at a temperature in the range of from about 150.degree. to about 400.degree.F., and

d. Applying a finish coat to the crushed foam coated substrate.

2. A process according to claim 1 for preparing finished leather and leather substitutes which comprises:

a. Applying a coating of a polymeric acrylic latex which coating is foamed on the substrate by the use of a blowing agent selected from, 1) a solvent having a boiling point in the range of from about 75.degree. to about 200.degree.F. and in which the uncrosslinked polymer exhibits a swell ratio in the range of from 1 to about 7 or, 2) a chemical blowing agent selected from an azo compound, N-nitroso compound, sulfonyl hydroxide, ammonium bicarbonate, sodium bicarbonate, sodium carbonate, hydrogen peroxide, ammonium nitrate, or malonic acid;

b. Drying and foaming the latex coated substrate at a temperature in the range of from about 170.degree. to about 390.degree.F.;

c. Crushing, embossing and curing the foam coated substrate at a pressure in the range of from about 5 to about 1200 psi at a temperature in the range of from about 150.degree. to 320.degree.F., and

d. Applying a finish coat to the crushed foam coated substrate wherein the finish coat is selected from compositions containing nitrocellulose, urethane, polyvinyl chloride, acrylics, cellulose acetate butyrates or nitrocellulose modified urethanes or combinations thereof.

3. A process according to claim 2 for preparing finished leather which comprises:

a. Spraying a coating of a polymeric acrylic latex on leather which coating is foamed on the leather by a solvent blowing agent having a boiling point in the range of from about 75.degree. to about 200.degree.F. in which the uncrosslinked polymer exhibits a swell ratio in the range of from 1 to about 6.0;

b. Drying and foaming the latex coated leather at a temperature in the range of from about 120.degree. to about 400.degree.F.;

c. Crushing, embossing and curing the foam coated leather at a pressure in the range of from about 15 to 1200 psi at a temperature in the range of from about 150.degree. to about 300.degree.F. and

d. Applying to the crushed foam coated leather a finish coat composition containing nitrocellulose and an isocyanate terminated polymer of an organic poly isocyanate with a polyester or polyether polyol or cellulose acetate butyrate.

4. The process of claim 3 wherein Step C is conducted at a temperature in the range of from about 180.degree. to 270.degree.F.

5. A process according to claim 2 for preparing a finished leather substitutes which comprises:

a. Spraying a coating of a polymeric acrylic latex on a leather substitute which coating is foamed on the leather substitute by a solvent blowing agent having a boiling point in the range of from about 75.degree. to about 220.degree.F. in which the uncrosslinked polymer exhibits a swell ratio in the range of from 1 to about 6.0;

b. Drying and foaming the latex coated leather substitute at a temperature in the range of from about 120.degree. to about 400.degree.F.;

c. Crushing, embossing and curing the foam coated leather substitute at a pressure in the range of from about 5 to about 2500 psi at a temperature in the range of from about 150.degree. to about 400.degree.F., and

d. Applying a finish coat to the crushed foam coated substrate.

6. The process of claim 5 wherein Step C is conducted at a pressure in the range from about 50 to 1000 psi at a temperature in the range from about 275.degree. to about 325.degree.F.

7. A method according to claim 1 wherein the polymeric latex comprises at least 2 of the following monomers of which at least one is a monomer containing a functional group capable of crosslinking:

a. an .alpha.,.beta.-ethylenically unsaturated acid;

b. A monomer of the formula; ##EQU5## wherein R is hydrogen or alkyl and R.sup.1 is a straight, branched or cyclic alkyl, alkoxyalkyl or alkyl thioalkyl radical and

c. A monomer of the formula; ##EQU6## wherein R.sup.2 is hydrogen or methyl; and R.sup.3 is halo, alkanoyloxy, cyano, phenyl, formyl, carbamoyl, epoxy, N-hydroxy methylcarbamoyl, tolyl, methoxy methyl, 2,4-diamino-s-triazinyl lower alkyl or

d. A monomer of the formula; ##EQU7## wherein R.sup.4 is hydrogen or methyl; R.sup.5 and R.sup.6 are lower alkoxy or lower alkanoyloxy.

8. The method of claim 7 wherein the polymeric latex contains a monomer chosen from at least three of the following groups:

a. ethyl acrylate or butyl acrylate;

b. acrylonitrile;

c. acrylamide, methylol acrylamide, allyl acetoacetate, hydroxyethyl methacrylate, methyl methacrylate, acrolein or methacrolein or

d. acrylic acid or methacrylic acid.

9. The process of claim 8 wherein the polymeric latex contains a monomer chosen from at least three of the following groups:

a. ethyl acrylate or butyl acrylate;

b. acrylonitrile;

c. acrylamide, methylol acrylamide, allyl acetoacetate, hydroxyethyl methacrylate, methyl methacrylate, acrolein or methacrolein or

d. acrylic acid or methacrylic acid; and also contains a filler selected from clay, mica, calcium carbonate, or silica; a foam stabilizer; a colorant and a crosslinking agent selected from ammonia, a dibasic amine or a melamine resin.

10. A process according to claim 2 wherein the solvent blowing agent is selected from dichlorodifluoromethane, carbon tetrafluoride, trichlorotrifluoroethane, trichlorofluoromethane, monochlorotrifluoromethane, monobromotrifluoromethane, monochlorodifluoromethane, octafluorocyclobutane, pentane, hexane, or cyclohexane.

11. The process of claim 3 wherein the blowing agent is selected from trichlorofluoromethane or trichlorotrifluoroethane.

12. A process according to claim 3 wherein the chemical blowing agent is ammonium bicarbonate.

13. A crushed foam coated leather or leather substitute wherein the crushed foam coating is prepared by the process of claim 1 and the polymeric acrylic latex employed is prepared from at least two of the following monomers of which at least one is a monomer containing a functional group capable of cross-linking:

a. an .alpha.,.beta.-ethylenically unsaturated acid,

b. a monomer of the formula ##EQU8## wherein R is hydrogen or alkyl and R.sup.1 is a straight, branched or cyclic alkyl, alkoxyalkyl or alkyl thioalkyl radical and

c. a monomer of the formula ##EQU9## wherein R.sup.2 is hydrogen or methyl; and R.sup.3 is halo, alkanoyloxy, cyano, phenyl, formyl, carbamoyl, epoxy, N-hydroxy methylcarbamoyl, tolyl, methoxy methyl, 2,4-diamino-s-triazinyl lower alkyl or

d. a monomer of the formula ##EQU10## wherein R.sup.4 is hydrogen or methyl; R.sup.5 and R.sup.6 are lower alkoxy or lower alkanoyloxy.

14. A crushed foam coated leather or leather substitute wherein the crushed foam coating is prepared by the process of claim 2 and the polymeric acrylic latex employed contains monomers chosen from at least three of the following groups:

a. acrylic acid or methacrylic acid;

b. ethyl acrylate, butyl acrylate or methyl methacrylate;

c. acrylonitrile and

d. acrylamide, methylol acrylamide, allyl acetoacetate, hydroxyethyl methacrylate, acrolein or methacrolein.

15. A crushed foam coated leather or leather substitute wherein the crushed foam coating is prepared by the process of claim 2 and the polymeric acrylic latex employed contains monomers from at least 3 of the following groups:

a. acrylic acid or methacrylic acid;

b. ethyl acrylate, butyl acrylate or methyl methacrylate;

c. acrylonitrile and

d. acrylamide, methylol acrylamide, allyl acetoacetate, hydroxyethyl methacrylate, acrolein or methacrolein and also contains a filler selected from clay, mica, calcium carbonate or silica, a foam stabilizer, a colorant and a cross-linking agent selected from ammonia, a dibasic amine or a melamine resin.

16. The crushed foam coated leather or leather substitute of claim 15 wherein the crushed foam coating is prepared from a copolymer having the following monomer composition: 96 ethyl acrylate/3.5 acrylamide/0.5 acrylic acid; 96 ethyl acrylate/4 acrylamide/methylol acrylamide; 94 ethyl acrylate/5.5 allyl acetoacetate/0.5 acrylic acid; 94.5 ethyl acrylate/5 hydroxyethyl methacrylate/0.5 acrylic acid; 66 ethyl acrylate/32.7 methyl methacrylate/1.3 methacrylic acid; 83 ethyl acrylate/15 methyl methacrylate/2 acrylic acid (Na); 83 butyl acrylate/15 acrylonitrile/1 acrolein/1 acrylic acid; 65 ethyl acrylate/25.5 butyl acrylate/4.5 acrylonitrile/3.5 acrylamide/1.5 itaconic acid; 86 ethyl acrylate/10 acrylonitrile/4 acrylamide/methylol acrylamide; 83 butyl acrylate/14 acrylonitrile/1 acrolein/2 acrylic acid; 97 ethyl acrylate/1 acrolein/2 acrylic acid; 68 butyl acrylate/28 methyl methacrylate/2 acrolein/2 acrylonitrile; 30 butyl acrylate/55 ethyl acrylate/10 methyl methacrylate/3.5 acrylonitrile/0.5 acrolein/1 acrylic acid or 45 butyl acrylate/10 acrylonitrile/40 ethyl acrylate/4 hydroxyethyl methacrylate/1 acrylic acid.

17. A shoe upper material comprising a crushed foam coated leather or leather substitute prepared by the process of claim 1 wherein the crushed foam coating is prepared from the polymeric latex of claim 13 and which crushed foam coated leather and leather substitute has a finish coat composition containing one of the following ingredients: nitrocellulose, urethanes, polyvinyl chlorides, acrylics, cellulose acetate butyrates or a composition containing nitrocellulose and an isocyanate terminated prepolymer of an organic polyisocyanate with a polyester or polyether polyol or mixtures thereof with or without plasticizers.

18. A shoe upper material comprising a crushed foam coated leather or leather substitute prepared by the process of claim 2 wherein the crushed foam coating is prepared from the polymeric latex of claim 14 which crushed foam coated leather and leather substitute has a finish coat composition containing cellulose acetate butyrate, nitrocellulose and/or an isocyanate terminated prepolymer of an organic polyisocyanate with a polyester or polyether polyol.

19. A shoe upper material comprising a crushed foam coated leather or leather substitute prepared by the process of claim 2 wherein the crushed foam coating is prepared from the polymeric latex of claim 15 which crushed foam coated leather and leather substitute has a finish coat composition having 15-55% nitrocellulose.

20. A shoe upper material comprising a crushed foam coated leather prepared according to claim 3 wherein the crushed foam coating is prepared from the polymeric latex of claim 16 which crushed foam coated leather has a finish coat of 0.1 to 8 mils dry film thickness of a composition having a 15-55% nitrocellulose.

21. A shoe upper material comprising a crushed foam coated leather substitute prepared according to claim 3 wherein the crushed foam coating is prepared from the polymeric latex of claim 16 which crushed foam coated leather substitute has a finish coat of 0.1 to 8 mils dry film thickness of a composition having a 15-55% nitrocellulose.

22. The shoe upper of claim 20 having a finish coat of 0.3 to 0.5 mils dry film thickness.

23. The shoe upper of claim 21 having a finish coat of 0.3 to 0.5 mils dry film thickness.