US3919451A

US3919451A - Method for finishing leather and leather substitutes

Info

Publication number: US3919451A
Application number: US377885A
Authority: US
Inventors: Jerome F Levy; Hugo A Alps; Michael L Alderman; David A Templer
Original assignee: Rohm and Haas Co
Current assignee: Rohm and Haas Co
Priority date: 1973-07-09
Filing date: 1973-07-09
Publication date: 1975-11-11
Anticipated expiration: 1992-11-11
Also published as: GB1465618A; PL103078B1; FR2236941A1; AU6972174A; JPS5036603A; IT1015669B; SU582777A3; IN141916B; IE39788B1; ES427247A1; JPS5713600B2; CA1027813A; IE39788L; AR199844A1; BE817430A; DE2425553A1; FR2236941B1

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

United States Patent [1 1 Levy et al.

[ 1 NOV. 11, 1975 1 1 METHOD FOR FINISHING LEATHER AND LEATHER SUBSTITUTES [75] inventors: Jerome F. Levy, Dresher; Hugo A.

Alps, Huntingdon Valley; Michael L. Alderman, Broomall', David A. Templer, Huntingdon Valley, all of Pa.

[73] Assignee: Rohm & Haas Company,

Philadelphia, Pa.

[511 int. CL C14C 11/00 158] Field of Search 117/11. 76 R, 44.80, 83, 117/86.105.3,142,105.4.163,161UT.161 UZ. 66, 65.2. 98. 90; 69/175. 21; 156/77, 78. 79, 83; 264/321, 47; 8/9421; 161/226. 160; 260/25 R; 36/45, 47

[56] References Cited UNITED STATES PATENTS 2.549.985 4/1951 Normington 69/21 3.103.447 9/1963 Lowell et al. 117/142 3.355.535 11/1967 Hain et al. 264/321 3.361.695 1/1968 Wolf et a1. 117/76 R 3.527.654 9/1970 Jones et a1. 117/66 3.537.947 11/1970 Brazdzionis 156/78 3.574.154 4/1971 Shaw et al. 260/16 3.607.341 9/1971 Goins et a1 117/11 3,640,916 2/1972 Dill 260/296 TA 3,649,731 3/1972 Cronin 156/77 3.713.868 1/1973 Gordon et a1 117/163 3.763.061 10/1973 Lewis et a1 260/13 3.788.882 1/1974 Noone 117/98 3.788.887 1/1974 Traubel et al. 1. 6/77 3.817.880 6/1974 Kreider 260/25 R FOREIGN PATENTS OR APPLICATIONS 1.147.677 4/1969 United Kingdom. 117/76 R 949.859 2/1964 United Kingdom 117/11 928.901 6/1963 United Kingdom 733.024 4/1966 Canada 264/321 811.631 4/1969 Canada 8/9421 Primary Examiner-Douglas J. Drummond Assistant E.\'aminerJ. J. Gallagher {57] 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.

23 Claims, N0 Drawings METHOD FOR FINISHING LEAIHER ANI) LIiA'IIIICR SIIBSII'IITES 'lhis invention relates to a no\ cl process for line-thing leather splits. low grade corrected and full grain leathers. nonwovcn \icbs and other artifical webs applica ble 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 \vhilc dramaticalh reducing the number of steps to quired in achiciing the finished product. in addition. the resulting product maintains or impro. es the proper tics required of a leather or leather-like nratciml used in the manufacture of shoes. purses. garments. belts. upholstery. wallets and the like; namely. lle\ibilit abrasion resistance. adhesion. water \apor pcrmcal ilit scuff resistance. hand or temper. and leather-like aesthetics. a balance of properties not obtainable. coat ing by other available procedures.

This imention is cspecialh applicable to finishing leather and leather substitutes uhich posscss 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 lcatbci likc 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 altcrnath es to the nricroporous urethane laminate presently used to surface tlic essentially nomvoven base web of poromcric materials.

Textile fabrics have been successfully coated with polymeric compositions or formablc polymeric compo sitions which foam on the textile (US, Pat. No. 3.517.654). This procedure has not been successfully adaptable to the nonwoven substrates. such as the leather finishing arts. because of the l'lalancc of proper ties required for leather and leather substitutes which is different and more difficult to achieve than with con ventional 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. Ihc softness of hand of the leather and leather substitutes prepared by this invcin tion is greatly improved over material which has been treated with conventional finishes. By this process. out standing hiding is assured by a one coat irpplitation 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 pro cess for upgrading leather and leather substitutes. Still another advantage is the controlled buildup of thc coating which eliminates photographing.:" of the underlying substrate.

By the instant process one is able to ntili/c in to ordinary lcathcr substitutes poor quality which previously was not considered suitalih i" finish ing. 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 proiide an excellent finished leather. This process is especially applicable to leather splits. By this process. leather splits achic\e a higher level of aesthetics and physical pcrlormance than is currently possible uith comentional split finishing techniques.

fhis process also eliminates the ncccssity for impregnating the leather substrate. though we haic found that in certain situations a better product may be obtained hen impregnating is done the owrall properties ofthc sy stem are controlled by the properties of the foamable latex which allo\\s one to obtain a soft. flexible. water vapor permeable coat and together nith a llnish coat of a durable resin system one obtains the desired abrasion and scuff resistance t'tl't |!ct'llL\ without detracting from the flexibility and water vapor permeability characteristic of the latert grain lay er uhich has been introduced as the foam coat. Both the foam coat and finish coat determine the tiltimate properties and performance of the s stem.

'l'his imention also embraces the coating of leather substitutes to afftrrd material ritalling that of high grade leather llic tcrni leather substitutes" is as de lined in IRS. Pat, Nos. 1 537.883; 3.100.721 and .llllll.7fi7

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

thi inrcntion prrnidcs a novel process for preparing finished leather and finished leather substitutes which coinpriscs treating various substrates including grain leather. upper leather. leather splits. reconstituted leather. leather substitutes. nonavoven webs possessing extensibility and recovery. resilcncy 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 b. to about 2Z(tF. in which the uncrosslinked polymer exhibits a swell ratio in the range of from l to about 7 or 1. a chemical blowing agent:

b. drying and foaming the latex coated substrate at a temperature in the range of from about 120 to about ttlttli.

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 l5 l to about -llltl"l and d. applying a linish coat to the crushed foam coated substrate.

A preferred embodiment of the imcntion 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 I. a solicnt having a boiling point in the range of from about 75 to about ZZII F. and in which the nut rosslinkcd polymer exhibits a swell ratio in the range of from 1 to about 7 or Tl. ammonium bicarbonate;

b. drying and foaming the latex coated substrate at a temperature in the range of from about I50 to about WWI";

c. crushing. embossing and curing the foam coated ubstrate at a pressure in the range of from about 5 to about ZStltt psi at a temperature in the range of from 3 about 150 to 325F.. 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. ce lulose acetate butyrates. nitrocellulose. modified urcthancs 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 to about 220F.. 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 to about 325F.'.

c. crushing. embossing and curing the foam coated leather at a pressure in the range of from about to 1200 psi at a temperature generally in the range of from about 150 to 300F. but preferably at a temperature in the range of 180 to about 270F.. 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 to about 220F. 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 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 to about 400F.. and. preferably. at a temperature in the range of from about 275 to about 325F.. 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 doviations from those conditions including temperature 4 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. 1f 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 dichlorodifiuoromethane. carbon tetrafluoride. trichlorotrifiuoroethane, pentane. hexane. cyclohexane. trichlorofluoromcthane. monochlorotrifluoromethane. monobromotrifluoromethane. monochlorodifluoromethane. octafiuorocyclobutane and isomers thereof.

The amount of blowing agent solvent employed may vary from about 3 to about percent by weight of the total weight of the formulation. In general. the solvent chosen is from about 7 to l2 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-NN'dinitrosoterephthalamide. N.N'-dinitrosopentamethylenetetraminc and the like and sulfonyl hydrazides such as benzenesulfonylhydrazide. ptoluencsulfonylhydrazide, 4,4 '-oxybis( benzene'sulfonylhydrazide) 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 60 gni./sq. ft. wet addon 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 to about 400F. Some crosslinking occurs during this step and it is necessary to prevent a large amount of crosslinking 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. l.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 l to about 400F. and preferably. at a temperature in the range of l50to 325F. 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 (eg 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 US. 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 based on the total solids of the composition. These preferred coating compositions are further described in the US. patent application Ser. No. l6l.987 now US. 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 7 of 55M? to give the best balance of properties in terms of tlex. abrasion resistance and tack. This urethane/nitrocellulose ratio can be aried if necessary from 50.50 to 65;"35 to obtain a particular result on a specific leather but if changes are made. ties. abrasion resis tance and tack should be followed. Generally. the latex coatings employed in this invention should contain a latex polymer. clay. titanium dioxide or other inert tillers and a foam stabilizer and may contain an additive for erosslinking 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 rufi-ethylcnically unsaturated acid which ineludes acrylic acid. methacrylic acid. ethacrylic acid. itaconic acid. aconitic acid. crotonic acid. citraconic acid. maleic acid. fumaric acid, rt chloroacrylic acid. cinnamic acid. mesaconie acid. and the like. Mixtures of these acids can also be used;

b. a monomer of the formula R ll (life 0 Ant wherein R is hydrogen or alkyl. for example. lower alkyl of from [4 carbon atoms and R is a straight. branched or cyclic chain alltyl. alltosyalkyl or alkylthioalkyl radical haying from i to 20 carbon atoms. or cycloalkyl having from 5-6 carbon atoms. such as methyl. ethyl. propyl. irbutyl. lethylhexyl. heptyl. hexyl. octyl. Z-methylhutyl. l-methylbutyl. butoxybutyl. lmethyh pcntyl. methoxyrnethyl. ethosyethyl. cyclopentyl. cy clohexyl. isobutyl. ethylthioethyl. methylthioethyl. ethylthiopropyl. 6-methylnonyi. decyl. dodecyl. tetradecyl. pentadecyl and the like; R is also ureido. hy droxy lower alkyl of from l to 5 carbon atoms such as i *0] I. all.

hydroxymethyl. hydrosyethyi. hydroxypropyl. hydroty'butyl, hydroxypcntyl. and the like; 2.3epoxypropyl. amino lower alkyl or monoor dilower alkyl or by droxy lower alkyl substituted amino lower alkyl;

c. a monomer of the formula wherein R is hydrogen or methyl and R is halo such as chloro and the like; lower alkanoyloxy such as acetoxy and the like. cyano. formyl. phenyl. carbamoyl. l\'- hydroxymethyl. tolyl. methosylethyl. Z.-ldiamino-striazinyl lower alkyl. and epoxy;

8 wherein R is hydrogen or methyl: R and R are lower alkoxy such as methoxy. ethoxy and the like or lower alkanoyloxy such as acetoxy and the like.

Examples ofthe specific monomers described in sub paragraphs (b) and (c) and (d) which may be employed are: methyl methacrylate. ethylmethacrylate. propyl methacrylate. isopropyl methacrylate. n-huty'l methacrylate. isobutyl methacrylate. secbutyl methacrylate. tert-butyl methacrylatc. pentyl methacrylate. isopentyl methacrylate. tert pentyl methacrylate. hexyl methacrylate. cyelohcxyl methacrylate, lethylbutyl mcthacrylate. E-ethylhexyl methacrylate. octyl methac rylate. deeyl methacrylate. lauryl methacrylate. myristyl methacrylate. cetyl methacrylate. stearyl mcthacrylate. methyl acrylate. ethyl acrylate. propyl acrylate. isopropyl acrylate. butyl acrylate. isobutyl aeryiate. sec-butyl acrylate. tert-butyl acrylate. amyl acrylate, isoamyl acrylate. tertamyl acrylate. hexyl acrylate. octyl acrylate. Z-ethylhexyl acrylatc. inyl acetate. tetradecyl acrylate. acrylamide. pcntadecyl acrylatc. styrene. pentadecyl methacrylatc. inyl toluene. rnethacrylamide. N-methylolacrylamide and the lilte. glycidyl methacrylate. methylaminoethyl mcthacrylate. tertbutylaminoethyl methacrylate. FM. lbutenyl )-Z .4- diamino-s triazine. hydroxypropyl methacrylate. hydrosyethyl methacrylate. methacrylonitrile. methox ymethyl methacrylamide. Nanethylol methacrylamide. acrolein. methacrolein. 3.4-epoxyl-butene. acrolein diethyl acetal. acrolein dimethyl acetal. allyiidcne 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. diearboxylic 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 polymeri/able unsaturated monomers have reactive polar groups selected from Such groups may be included as are mutually or selfcrosslinkable. or separate crosslinking compounds such as triazineformaldehyde resin may be added.

Of course, atensensitnc 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 SEV eral monomers in the proper proportions. Conventional emulsion polymerization techniques are described in US. Pat. Nos. 2.754.280 and 2.795.654. 'l'hus. 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 polymeri/atinn initiator ol the tree radical type. such as am inoniurn or potassium persull'ate. may be used alone or in conjunction itith an accelerator. such as potassium nietahisullite. or sodium thiosuilate. l'rganic peroxides. such as hen /oyl peroxide and terthutyl hydropertWlitii. are also uschil initiators. lhe initiator and accel erator. commonly rettiiied to as catalyst. may he used in proportions irllti percent to Hi percent each based on the tie; it ol monomers to he eopolynicrized. 'l he amount. as indicated above. may be adjusted to control the intrinsic \ist'osity ot the polymer. lhe temperature may he l'roni l i lit temperature to about l4tl i 'lhe tollouing is a list ot eopolyiners uliieh may be employed in lltlr-l inwiition'. llie copolyiners haic th l'ollo ving monomer compositions, Jo .IiSAl lltL .SAA; ti'itii thilytttA. 94h 5 AIAL" AtltlJAA.

the use ol' a hater soluhie suilactant or a coniliina tion or sin'l'actants inciewses the dispersion ol the latex emulsion and acts as a foaming aid and foam stabilizer.

lhcse suilaetants include the alkali metal. amino ninm or amine salts. such as the monw. di or tricthanol amines ol' the aliphatic carhoxylic acids having from 1:1 to Ill carbon atoms including iileic acid. stearic acid and the like. ior eerniple. sodium. potassium or ammo nium stearate. sodium potassium or ammonium olcate and the like titlirr surfactants which may he employ ed together tvith those described ahove include the alkali metal salts ol aiiphatic or aikylaryl sullonic acids. such as sodium iauryl sulfate. sotliu ii dodecylhenyene sulfo natc and the like as ,'i ell a nonionic surfactants such as the poiyethyiene midi; condensates ol the aikyl phe nols or higher l rtt altaihols. I ir example. tertoctylphen l condensed with than 5 to about il) ethylene oxide units. illtll' yll|.lt.'l llt1 condensed with l ftllll to it! ethylene oxide llilll\ or similarly ethylene oxide con densities oi long chain niercaptans. liitty acids. amines and the like Although ilitct itriiaosct or thermoplastic resin:-

niay l c t'nipioytal in this process. the prch rrcd res n are the therniosrt ones since the foam generated at" fords leather and leather substitute products more dc sirahlc in the inan lhieture ot'aud snltsetpien use tith a ni not tilitrtt". for example. dieihylene int. i rlia'in' t th lilo. are employed It ruine t pe resins ate used to ttttf nl; the |)1.:l}'r'7ltlt.-; containing ii rlro ind amino functions Other ross ma we employed and sa d agent; are

iilletl in the alt.

iilll5" l"\|iii-'ii l."i Q lil riLil' l Lilli! linking agtnh in I. in. r

iinisi":

.rui.*cpiunii iis i-i lit. :ptniiing {r n the l l i .n itsthctii pialitit; a l .ue iupli g t tutwh h an he used in hnli. i.

l uzuir iinciy il lllli ti i nliinmrt iilain' ii ti itlctl no. t: Iill'llil lill ll and th ijtiit' l and iiiiahniu fit 10 sold by Dow (.orning and identified as DC-lfit). FCZT. Syl-Ott 'lJl together with a metal organic salt catalyst. for example. dihutyl tin laurate. zinc octoate and the like. lhcse tun chemicals further improve abrasion resistance and tactile aesthetics.

'l'hc finish coat compositions can he applied to the crushed foam coated substrates by any of the tech nit ues wellknoyyn in the art. including brushing. stvahhing. spraying. cuitain coating iflou' coating). or dip coating. Among the useful techniques are those described in US. Pat. Nos. 1126.321 and 2.884.34tl. One or more coats can he applied as desired. the thickness ot 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. (ienerally. the finish coat is applied so as to provide a deposit ol troni about til to about 5% mils dry film thickness and. preferably. from about 0.3 to about 05 mils dry tilin ll'liLiilitf.\%. After application. the coating can be cured by drying to a tack-tree state at room temperature for about Bil minutes to one hour. or by heating at a temperature ol up to ahout ltlllT. until the desired degree ot cure is effected.

An adutntage of the nitrocellulose/urethane finish coat is that it forms a coating which has outstanding elastic recovery and [leohility and yet is tough enough to he used as a wear layer when applied to leather or leather substitute in luggage or upholstery. and in garments such as shoe: jackets and the like. These characteristics of flexibility and elastic recoycry make the nitrocelluloschirethane finish coat compositions extremely valuable in the coating of thick flexible suhstrates. and particularly with those substrates having a thickness of from about 3i! mils to about ltlt) 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. eg. in ethylene glycol. ether. xylene. ethylene glycol mononiethyl ether and the like by \tc'll'kli WIi conventional means such as tree-radical initiation vii .li henzoyl peroxide or the like are also Luzeiu Solu ion polymers useful in the inven titan prel nial ly l a t' a molecular Weight oi hetivccn lillillli and i li ll llltli l the iiiimulation oi the crushed toani coating is capahlc ml a. wide ariation. The following table illustrates the comptviems of he io rnulation which may be enipli a. tt l:

Pat is li Ti -l nniue ltcsnr.

be understood that other ingredients can be incorptn tvd into the [train coating iorrnulation. in pan titular. till-as. olorants and waxes are added to the iorinulation 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 pig ments 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 I Formulation 1 Charge Parts by Weight Copoly mcr com posed of MBA/HAN/IAQ'ZAA 100 China (lay l Ammonium Stearate (33 i I 7.0 Diethylenetriamine on Ammonium Hydro\ide (26%| 20 Primal Non-Bleeding Red Colorant 15.0

EXAMPLE I Formulation Z Copoly rncr composed of KZ5BAHIJANJl5Ac/3AA 500.0 Clay 75.0 Ammonium Stcaratc 35.0 Diethylenctriaminc 3.5 Ammonia (28'; 10.0 Primal llroun Colorant 750 Water (155 EXAMPLE 3 Formulation 3 Copoly mer composed of XoEAllUAN/JMOA 565.5 Clay 75.0 Ammonium Stearate 35.0 Aqueous melamine formaldehyde resin l [.5 Ammonia (3)") I 10.0 Primal White Zo-l Colorant 75.0

EXAMPLE 4 Formulation 4 Charge Parts by Weight H. 65.5 NH 12W) loo Clay 75.0 Primal Blk. 1H) 75.0 Copolymer composed of 9hEAl3MOA105AA 500.0 Ammonium Stcarate 35.0

EXAMPLE 5 Formulation 5 Primal Blk. Ill) 75.0 NH (INK 1' I l0.0 Clay 75.0 Copoly mer composed of 9hEA/3MOA/05AA 565.5 Ammonium Stcarate 35.0 Aqueous melamine formaldehyde resin l l.5

EXAMPLE 6 Formulation h Primal Ochre Yellon 75.0 NH 12x 1) nu) (lay 75.0 (opolymer composed of )hEABMOAJ05AA 565.0 Ammonium Stcarate 35.0 Melamine ll.5

The components of Examples 1 to 6 are added to the mix in the order given (the NH:; 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 mel amine formaldehyde. After mixing. the formulated mix is covered to prevent skinning over.

EXAMPLE 7 Formulation 7 (hargc Parts by Weight Copoly mcr composed of K3llAfl-lAl\/lAcr2AA 410.5 Ammonium Stearate 15.8 Octylphenoxy polyethoxy ethanol ll.5 Acme WW Clay 7.5 Primal Black ll0 41.7 NH. (15'1') 7.0 Polyethylene Wax 23.9 Dicthylenc triaminc ll hll().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 mesh). This material is now ready to be employed with an appropriate blowing agent. By substituting for the colorant. Primal Black H0. 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 g). and dichlorodifluoromethane (40 g.) are charged to a six ounce aerosol can with a nonbreakup nozzle. The can is shaken and the contents sprayed onto l 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 190F.. 30 tons. 3 seconds). Density of the foam sprayed is approximately 0.007 gms./cubic centimeter.

By employing a charge of 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. l5 pounds pot pressure). The mixture is sprayed onto leather at approximately L3 to 1.5 ounces wet add-on per square foot. The mixture foams slightly at room temperature but upon drying at 280F. the coating foams up well. Crushing. embossing and curing are accomplished simultaneously on a Watson Stillman Press at lF.. 30 tons. for 3 seconds.

EXAMPLE l0 Spray Gun The experiment of Example 9 is repeated using trichlorotrifluoroethane except that the leather split employed is heated for several minutes at 280F. before applying the coating. The coating when applied to the 13 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 l l Foaming Properties of Acrylic Emulsion Polymers Using Triehlorotrifluoroethanc 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; (28% 5.0 g.; colorant 537.5 g. and trichlorotrifluoro ethane 35 g. The formulations are sprayed with pot pressure spray equipment at l5 lbs. pot pressure and 80 lbs. line pressure. The substrate used is a white cardborad paper panel l4/2 inches X 11 /2 inches. After spraying, the coating is air dried for l minute and then dried for five minutes in a forced draft oven at 280F.

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

l. 96EA/3.5AM/0.5AA 96EA/4MOA 94EA/55ALACAC/05AA 94.5EA/5HEMA/05AA 66EA/327MMA/L3MAA lEA . 83EA/l5MMA/2AA(Na) .83BA/lAN/lAC/1AA 65EA/25.5BA/4.5AN/3.5AM/l.5lA

l l. Butadiene rubber (Hycar l57l EA ethylacrylate; BA butylacrylate; MMA mcthylmethacrylate;

AA I acrylic acid. MMA methacrylic acid; lA itaconic acid;

HEMA hydroxyethyl methacrylate; AN acrylonitrile; AC acrolein. ALACAC ally'l acetoacetate. MOA acrylamide/methylol acrylamide l:l and AM 2 acrylamide.

'i of Solvent h.p. in l00 Pts. Snell Solient C. Formulation Foam Ratio l. (H- Cl- 39.7 5% No Foam |9.hl CH Cl 39.7 lll i No Foam 19.6] I. CHCL, (ill 5" No Foam 44.74 (HCl, 62.] I09 Slight Foam 44.74 3. C(l Cl-L. 47.3 5' l Lniform Foam 2.53 CCI CF 47.3 lll'T i Uniform Foam 2.53 4. CCl F 23.8 5". r' Lniform Foam 5.57 (Cl F 23.6 10? Uniform Foam 5.57 5. Pentane 64 5'71 Uniform Foam I.Zl Pentane 64 10") Uniform Foam 1.11 6. Hexane (18.7 5% Uniform Foam L07 Hcvanc (18.7 l0v' 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 l540). The pressure is reduced to 5l mm. of Hg and the tem perature raised to 70C. while agitating the mixture. The distillate. 45.5 g.. is collected and the temperature reduced to 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 75C. for l6 hours. The isocyanate content is determined and the product cooled to room temperature. The prepolymer has the following properties:

7( Solids 74.2]; Meq. NCO/g. solution 0.834; G. H.. Viscosity T+'. Residual TDI l.l7.

Step 8 Preparation of Finish Coat Composition The finish coat composition is prepared by mixing RESU LTS Foam Add-on Applied Brookfield Polymer Rating (g./sq.ft. I Solids pH \"isc. (cps) Hue 1 Good 44.3 9.4 High Bluish Black I Fair-Good l4.4 44.3 9.9 336 Bluish Black 3 Fair'Uood l4.4 44.3 8.6 168 Bluish Black 4 Fair-(jootl 21.6 44.3 9.8 6-43 Bluish Black 5 Good-Yer) Good 144 43.5 10.] 660 Bluish Black 6 Fair-Good lol 44.3 l0.0 4X (ireenish Cast 7 Fair(iooil l0.2\ 37.5 10.: I636 Bluish Black 8 Fair-Good Ill 44.3 9.7 88 Green 9 (iootl l4.0 44.3 9.7 l l 300 Green 10 (iootl 19.8 44.3 9.4 360 Bluish ll \'cr (jood 8.5 38.3 |0.l 40 Bluish Black S c \N EXAMPLE [2 the follow mg ingredient (parts by eight). prepolymtr Evaluation of Solvent Blowing Agents of Step A (110). nitrocellulose (177). nitrocellulose plus a dulling agent black pigment. plasticizer and nitrocellulose (200). butyl acetate. xylene and 2- ethoxyethyl acetate (413 parts in a ratio of 50140110). a silicone rubber polymer (25. "Dow Corning I60") 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 15 that about I .0 g, of solids per square foot of substrate is obtained.

By substituting other prepolymers for the prepolymers employed in Example 12, Step 8. by substituting other pigments or dyes for the black pigment employ ed other pigments and by employing other silicone rubber and prepoly mers and catalysts other similar finish coat compositions can be prepared.

EXAMPLE 14 Finish Coat and Application of Cellulose Acetate Buty rates Step A 97.5 parts polyt 1,3-butylene adipate} obtained by a conventional process, having a molecular weight of 5,000 and a hydroxy number of 20, is thoroughly dehy drated by sparging with nitrogen at 130 to 140C. The polyester is then cooled to 106 to 108C. and 4h parts of methylene-twist-lphenylisocyanatcl is added over a period of 15 minutes. The temperature of the reaction mixture is raised to 1 to l C. and mi ing is eontinued under a positive pressure of nitrogen for hours. The cooled product has a viscosity of about one million poises and is a light-colored stiff gum. A solution in xylene has a Gardner Holdt viscosity of Z Step B Formulation of Clear Plasticizcd Cellulose Acetate Butryate Solution A solvent mixture is prepared by blending 510 parts of toluene, 170 parts of methyl ethyl ketonc, and 320 parts ethyl alcohol. To (19 parts of this solvent mixture are added 1 5 .1 parts of 3-second viscosity cellulose acetate butyrate comprising 205' butyryl and 15% aeetyl content followed by 38 parts of a linear polyester. namely, propylene glycol sebacate having a molecular weight of 8,000 and 12. l 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 8 is mixed with parts of methyl ethyl ketone and l part ofa 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 320F. for 60 seconds with a sandblasted platen. The resulting finish has a warm brown color and possesses outstanding resistance to cracking H or dulling when flexed.

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

What is claimed:

l. 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 sub strates by said blowing agent selected from, 1) a solvent having a boiling point in the range of from 16 -50 to 20F. in which the uncrosslinlted 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 to about 400F.;

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 to about 400F., 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 ofa blowing agent selected from, 1 a solvent having a boiling point in the range of from about 75 to about 200F. and in which the uncrosslinked polymer exhibits a swell ratio in the range of from 1 to about 7 or. 7.] a chemical blowing agent selected from an azo compound, ll-nitroso compound sult'onyl hydroxide, ammonium bicarbonate. sodium bicarbonate, sodium carbonate, hydrogen peroxide, ammonium nitrate. or malonic acid,

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

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 to 320F., 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 to about 200F. in which the uncrosslinked polymer exhibits a swell ratio in the range of from 1 to about (1.0;

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

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 to about 300 b 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 -l. The process of claim 3 wherein Step C is con ducted at a temperature in the range of from about 180 to 270F.

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 to about 310F in which the uncrosslinked polymer exhibits a shell ratio in the range of from 1 to about no. Dry ing and foaming the late\ coated leather substitute at a temperature in the range of from about lZll' to about -lllll l"; c. (rushing embossing and curing the foam coated leather substitute at a pressure in the range of l'rom about 5 to about 150i! psi at a temperature in the range ol' from about lfiU to about 4uoFi and r tpply mg a finish coat to the crushed toam coated substrate (a. l he process of claim 5 wherein Step C is conducted at a pressure in the range from about St! to i000 psi at a temperature in the range from about 275 to about FIFlz 7. A method according to claim 1 wherein the poly mcric late\ comprises at least 1 of the lollowing monomers ol' whieh at least one is a monomer containing a lunctional group capable ol crosslinkingi a an Etifi illlylUlliCLEli) unsaturated acid;

Ii. A monomc: otthc formula;

Ht) ll wherein R is hydrogen or alkyl and R is a straight branched or cyclic nlkyi alkoxyalkyl or alkyl thioalkyl radical and c. A monomer oi the formula;

wherein R is hydrogen or methyl; and R is halo, alkanoyloxy cyano, phenyl lormyl carbamoyl, epoxy, N-hydrosy incthylcarbamoyl tolyl mcthoxy methyl. ZA-diaminostria/inyl lower alkyl or d. A monomer of the lormula;

wherein R is hydrogen or methyl; R" and R are lower alkoxy or lower allomoyloxy:

8. The method ofclaim 7 wherein the polymeric latex contains a monomer chosen from at least three of the following groups a ethyl acrylate or hutyl acrylate;

b. acrylonitrile,

cl acrylamiilc methylol acrylamide allyi acetoacctatc hydrmyethyl mcthacrylate. methyl methacrylate acrolcin or i'nethacrolein or d. acrylic acid or meihacrylic acid.

9. The pa occss ol claim 3 wherein the polymeric latex contams a monomer chosen from at least three of the liiliowing groups:

a ethyl acrylatc or liutyl acrylate;

h. it clyltllllll llCr c. acrylaninlc nictlnlol acrylamidc allyl acctoacetate. lndioit setlrtl methacrylate methyl methacrylate acroleiii or illCilhlCltllLZlH or d acrylic acid or methacrylic acid and also contains a lillt'i selecttd lroin clay mica calcium carbon- 18 ate 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 sol 5 \Ltll blowing agent is selected from dichlorodilluoromethane. carbon tetratluoride. trichlorotritluoroethane triehlorotluoromethanci mUHOClIlUTOIFlllUOI'OIULP thane monobromotritluoromcthane monochloroditlu oromethane octalluorocyclobutane, pentane. hexane. or cyclohexancr l l. The process of claim 3 wherein the blowing agent is selected from trichlorotluoromethane 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 substi tute wherein the crushed t'oam coating is prepared by the process of claim 1 and the polymeric acrylic latex employed is prepared from at least two ot the following monomers of which at least one is a monomer containing a functional group capable of cross-linking:

a. an (riti'cthylcnically unsaturated acid. b. a monomer of the formula Ill no lll wherein R is hydrogen or alkyl and R' is a straight, branched or cyclic alkyl, alkoxyalltyl or alkyl thioalkyl radical and c a monomer of the formula wherein R is hydrogen or methyl; R and R are lower alkoxy or lower alkanoyloxy 14. A crushed foam coated leather or leather substi tute wherein the crushed foam coating is prepared by the process ol 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 acrylato butyl acrylate or methyl methacrylate;

cl acrylonitriie and d. acrylamide. methylol acrylamidc allyl acetoacetate hydroxyethyl methacrylate acrolein or meth aciolein.

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 mcthacrylate;

c. acrylonitrile and d acrylamide. methylol acrylamide. allyl acctoacetate. hydroxyethyl methacrylate. acrolcin 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/35 acrylamide/(LS acrylic acid; 96 ethyl acrylate/4(l/l acrylamide/methylolacrylamide); 94 ethyl acrylate/5.5 allyl acetoacemm! 0.5 acrylic acid; 94.5 ethyl acrylate/S hydroxyethyl methacrylate/O.5 acrylic acid; 66 ethyl acrylate/32.7

methyl methacry1ate/L3 methacrylic acid; 83 ethyl acrylate/lS methyl methacrylatc/Z acrylic acid (Na); 83 butyl acrylate/lS acrylonitrile/l acrolein/l acrylic acid; 65 ethyl acrylate/25.5 butyl acrylate/4.5 acryloni trile/3.5 acrylamide/l.5 itaconic acid; 86 ethyl acrylate/IO acrylonitrile/4 acrylamide/methylol acrylamide; 83 butyl acrylate/l4 acrylonitrile/l acrolein/Z acrylic acid; 97 ethyl acrylate/l acrolein/Z acrylic acid; 68 butyl acrylate/ZS methyl methacrylate/Z acrolein/Z acrylonitrile; 3U butyl acrylate/SS ethyl acrylate/lU methyl methacrylate/3.5 acry1onitri1e/0.5 acrolein/l acrylic acid or 45 butyl acrylate/lO acrylonitrile/4O ethyl acrylate/4 hydroxyethyl methacrylate/l 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. polyvi- 20 nyl 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 of0.1 to 8 mils dry film thickness of a composition having a l5557r 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.] 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 ()3 to 0.5 mils dry film thickness.

UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT N0. 3,91o,L

I flov b ll INVENTORG) Jerome F. Levy, Hugo A. Alps, Michael L. Aldenrtan,

I and David A. Templer It rs certrfred that error appears in the above-identified patent and that sard Letters Patent are hereby corrected as shown below:

In column 3, line ll, "such a full" should be changed to read such as full In column 3, line 42, "H002" should be ehar'rgged to read MOO" In column 13, line 35, "MMA" should be changed to read MAA In column 13, line 38, "AC" should be changed to read Ac Signed and Scaled this [SEAL] fourth y of y1976 A nest:

RUTH C. MAS Anmmg 3 c. MARSHALL DANN ("mmissmw lb' and Trademarks

Claims

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 SUBSTIITUTES WHICH COATING IS FOAMED ON THE SUBSTRATES BY SAID BLOWING AGENT SELECTED FROM, 1) A SOLVENT HAVING A BOILING POINT IN THE RANGE FROM -50* TO 220*F. IN WHICH THE UNCROSSLINKED POLYMER EXHIBITS A SWELL RATIO IN THE RANGE FROM 1 TO ABOUT 7 TO 2) A CHEMICAL BLOWING AGENT; B. DRYING AND FOOAMING THE LATEX COATED SUBSTRATE AT A TEMPERATURE IN THE RANGE OF FROM ABOUT 120* TO ABOUT 400*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* TO ABOUT 400*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* to about 200*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* to about 390*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* to 320*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* to about 200*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* to about 400*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* to about 300*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* to 270*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* to about 220*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* to about 400*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* to about 400*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* to about 325*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;

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

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.

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.

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