Патент USA US2135151код для вставки
‘2,135,151, UNITED STATES ‘PATENT OFFICE Patented Nov. 1, 1938 .~ ‘ 2,135,151 METHOD OF MULTIPLE-COATING OR ' FINISHING \._.,Milton 0. Schnr, Berlin, N. H., assignor to Brown . Company, 'Berlin Maine N. IL, a corporation of ’ No Drawing. Application May 23, 1936, > Serial No. v81,486 9 Claims. (01. si-ts) blotchiness of surface. Evidently the rubber sol This invention relates to a method of coating or ?nishing involving more particularly the use of a rubber latex coating composition of the sort that isto be applied to sheet material or the like a number’ of times and that is designed to 'dry smoothly and with‘proper amalgamation or merger of the separately applied thicknesses. .‘ While not limited thereto, the method of the present invention may be applied advantageously vent not only softens and swells the dispersed rubber particles of the composition so as to tran‘s- . form them to a stickier or tackier state, but softens an already deposited dried layer of com 5 position so as to result in an autogenous weld between layers, each layer being in effect an in crement that contributes to the masking of sur face blemishes on'the base being coated and to the building up of an adequately thick wear 10 10 in ?nishing the surface of arti?cial leather base or sheet material of the kind comprising. a ?brous resistant structure whose integrality is perhaps base, for instance, a felted ?brous base,‘ itself im ' bestshown by "the fact that under scu?’ or abrae. pregnated with rubber'latex- or similar rubber or ’ sion tests there is no observable tendency for rubber-like composition and dried. Indeed, the ~ peeling or separation between layers such as 1,5 method hereof has been found to be of great from the serviceability of a coated 16, vutility in ?nishing arti?cial leathers intended for woulddetract arti?cial leather for such ‘uses, e. g. shoe upper Such- exacting service as shoe-upper stock and require high wet and dry scuff resistance‘. comprising a rubber-impregnated web of felted stoc_k,~as I shall now describe typical coatingv composi- ' ?bers fabricated from re?ned wood pulps on ma- _ tions answering the purposes of my invention and 20 how they were prepared. It might be remarked 20 that the compositions about to be. described were ture and evenness of surface; , prepared with a view toward being used in coat I have found that an aqueous ‘coating composi ing arti?cial leather of the general character dis tion comprising water-dispersed rubber, such as’ closed in my already-mentioned patent applica 25 rubber latex solids,and preferably also water tion- Serial No.‘ 575,164. According to that ap— soluble glue or other water-soluble, ?lm-forming plication, arti?cial leather is made by impregnat ing a ?brous base with rglycerinated latex and then drying the impregnated base. Thatv ap 30 b plication dwells in particular upon the use of a soft, highly absorbent base such as is fabricated _ _ composition lends ‘to an on machinery of the ‘paper-making type from ?ber 30 arti?cialleather a surface reminiscent in many furnishes containing largely re?ned but substan respects of the skin or, enamel side of vnatural ~ ' tially unhydrated cellulose pulp, e. g. wood pulp leather, particularly when it contains glue and of an alpha cellulose content of at least about 35 its glue content undergoes an after-tanning treat 93%. It further stresses the value of the glycer ment with formaldehyde or other ‘ ' v ine in developing the desired pliancy or mellow 35 agent that develops maximum wet scu?-resisiw ness [in the arti?cial leather without detracting ance therein and when‘ it contains‘ glycerine as a from its toughness and other leather-like qualif ?exibilizing agent that imparts a mellow or pliant‘ ties. When the coating compositions of the pres; 40 feel thereto as well asincreases its ?ex endurance ent invention are applied to such arti?cial leather, and prevents migration thereinto ofsuclr glycer- . ine as may have been introduced along with latex solids into ‘the body of the arti?cial leather in -45 the manner and for the purpose disclosed in my application Serial No. 575,164, ?led November 14, 1931. I have further found that for the multiple 50 it is desirable to'introd‘uce glycerine thereinto for the reasons already indicated. Here is the for— v mula of a typical coating composition in terms of its non-aqueous ingredients other than the rubber-swelling agent: ' _. Percent by weight coating method hereof it is most desirable to emulsify into the aqueous coating composition in. Rubber latex solids___________ __ _________ .. 72 a substantially non~separating state su?lcient Glue___~_________________________________ __ 16 water-immiscible but volatile rubber solvent to Glycerine ____________ __>_i _______________ __ 10 50 swell the dispersed rubber particles appreciably ' Remainder black dye, anti-oxidant and a wet ting-out agent. i but short of inducing their coagulation. Through such use of a rubber solvent in the composition, The composition contains additionally 75% by 55 it is possible to gain such important bene?ts as . weight of toluol, based'onall of its non-aqueous perfect ‘amalgamation orwelding or successive ingredients exclusive of the toluol. ' 'The total 55 coats even though each coat is substantially com~ water content of the ?nished composition may be adjusted so that it contains about 15% by weight j pletely dried before the next one is applied so as - to avoid otherwise existing "running" tendencies 60 in the composition and atteudant'streakiness or of all non-aqueous ingredients exclusive of the toluol: In addition to the'advantages already mentioned, it has been found that the composi 2 2,135,151 . tion deposits smoothly on the arti?cial leather ‘possessing sufficient volatility to ‘be volatilized with su?icient rapidity in a current of warm air.. In this connection, it might be noted that when solve such greasy or other surface-‘resistant im- ' arti?cial leather is repeatedly coated with the purities as would otherwise cause localized shed composition of the present invention, it is re. ding and thinning out of the aqueous composition. peatedly run through a closed chamber in which The toluol also has a preservative effect on the currents of warm air are brought to play on each‘ composition, permitting the composition to be coating to dry it quickly so that a succeeding kept longer without putrefaction than is other coating may be applied thereover. Toluol not wise the case. only gives satisfactory results in the foregoing In preparing the foregoing composition, it is coating practice, but is reasonably cheap, not too 10 preferable ?rst to deammoniate the usual am hazardous from either a ?re or health standpoint, ' mania-preserved rubber latex of commerce used and lends itself to‘easy emulsi?cation as herein as a principal raw material. Otherwise the ad before described. It is possible to reduce or in dition of rubber solvent to the rubber latex may crease the amount of toluol in the compositions cause'undue thickening and subsequent coagu 15 hereinbefore described but without any particular lation to take place. Deammoniation of the latex bene?t. In any event, sufficient rubber solvent is may be effected by aerating it until substantially used to swell the dispersed rubber particles ap all of its ammonia content has been expelled. preciably but far short of inducing their coagula Substantially complete deammoniation of the ~ tion. While the ratio between the rubber latex 20 latex may also be had with little danger of local solids and water-soluble glue in the composition . coagulation by the addition thereto of such mild is also subject to considerable variation, a com acids as citric, oleic, lactic, oxalic, etc. However, positionv intended for coating arti?cial leather deammoniation of the latex by aeration is prefer preferably contains distinctly less glue than rub able in that such practice avoids an infusion into ber latex solids and, correspondingly, contains 25 the latex of bodies that may be undesirable there» much less glycerine than rubber solvent. in even in such small amount as attends substan 'Despite the fact that the coating compositions base, probably because the toluol tends to dis tial neutralization of the ammonia content of used in the method hereof contain the very in The glycerine, dye,- and anti-oxidant may be gredients, namely,v rubber and rubber solvent that go‘ to make the viscous and extremely sticky ordinary ammonia-preservedlatex of commerce.’ 30 mixed directly into the latex.‘ To this latex mix-' ‘ . mixtures or so-called rubber cements of the prior ture is then added an aqueous solution of the glue’ art, they are very fluent and in no way resemble containing stably emulsi?edtherein thetoluol, a suitable wetting-out agent, such as “Nekal BX”, a sodium salt of a naphthalene sulphonic acid 35 with side chains, preferably being present in in outward appearance such rubber cements. It might be observed that although the, glue in gredient is primarily valued because of the quali ties that it imparts to the dried coatings yielded > slight amount to enhance the stability ofthe by the coating composition of the present inven emulsion. The desired emulsion of toluol in the tion, yet it serves additionally as a remarkably ef aqueous glue solution may readily be prepared ?ci_ent emulsifying agent for the rubber solvent by dissolving the glue and wetting-out agent in so that there is no tendency whatever for the _ 40 water, raising it to a temperature of, say, about rubber solvent to separate out from the composi 100° F., and gradually adding the toluolto the tions. ' In using the term “glue" herein and in solution with stirring. The emulsion is gradually the appended claims, it should be understood added with gentle stirring to the latex mixture. that I mean to include albuminous substances, The viscosity of the ?nal mixture slowly rises dur such as blood albumen, ‘constituting equivalents 45 ing the ?rst hour or two as therubber particles therein absorb and are swollen by the toluol and of glue.‘ _ a. ' Ihave hereinbefore indicated that the glue con then remains substantially constant. tent of the coating composition is preferably in Another typical coating composition useful in ’ solubilized or tanned in order tovacquire maxi the method hereof has substantially the following formula in terms of its non-aqueous ingredients ~ other than the rubber-swelling agent: Per cent by weight _ vRubber latex solids ____________________ .__ 66.2 Glue ____- ______ -__..__'.. ____________ __-_____ 14.5 55 Glycerine Pigment_____ 60 ___ ‘ _ 9.2 -__ 9.27 . Wetting-out agent _____________ ___ ____ __'___ 0.5 Anti-oxidant _________________ _'_ ________ __ 0.33 This composition also contains additionally ‘75% by weight of toluol, based _ on all of its non aqueous ingredients exclusive of the toluol; and the concentration of all the ‘non-aqueous in gredients other than the toluol in the ?nished 65 ‘ composition is 15% by weight of the ?nished com position. The composition may be prepared ad mum wet scuff-resistance. To this end, afterthe ,. successive coats of composition have'been dried or set on the arti?cial leather base, the coated base may be‘exposed to formaldehyde fumes or‘ vapors at elevated temperature, under which con ditionsthe glue content of the successive coats ' is tanned or insolubilized. If ‘desired, such ?lm-forming substances as viscose, waterglass, water-soluble starches, etc., which are compatiblewith rubber latex, may be used in lieu of, or together with, the water-in soluble glue so as to develop the desired hardness and smoothness in the layer or. coating deposited from the compositions employed in the method , hereof. So, too, the method hereof might be em ployed with the coating compositions hereof con taining, in lieu of glycerine,'such equivalents'of glycerine as ethylene glycol and other homo- . blogues, glucose, etc., which function to plasticize vantageously in the same way as the ?rst-named ‘ the protein and resin content of the rubber latex and/or to soften the ?ber of the base to which The formulae of the foregoing compositions are such compositions are applied and more especially subject to considerable variation. Thus, the vola ‘ a rubber-impregnated,‘ ?brous base itself contain tile rubbersolvent employed may be xylol, gaso ing glycerine or other ?ber-softening agents that line, benzol, or their equivalents. However, toluol impart thereto a'mellow or pliant feel and in has worked out well in routine production because creased ?ex endurance, as hereinbefore described. 75 composition. _ , ' ' . 75 it is not too volatile at room temperature while , ‘ ~ ‘ 3 2,185,151 So far as concerns subject matter, this applica tion'is a continuation-in-part of my application Serial No. 759,801, filed December _29, 1934, now Patent ‘No. 2,060,l29,~date_d Nov. 10, 1936. 5%. I claim: I l. A method of smoothly coating a base which comprises applying thereto as successive smooth coats a very ?uent aqueous composition containing ing water-dispersed rubber, water-soluble glue, and su?icient water-immiscible but volatile rub- " ber solvent to swell the dispersed rubber particles appreciably but short of inducing their coagula tion; and drying the coats and insolubilizing their glue content; said rubber solvent not only swelling the dispersed rubber particles and transforming them to a stickier state but softening an already water-dispersed rubberfand su?lcient water-im applied and dried coat so as to ensure a 'non 10 miscible but volatile rubber solvent to swell the dispersed rubber particles appreciably but-short of inducing their coagulation; and developing a smooth multiple coating substantially devoid of streakiness and blotchiness by drying each coat 15 before a successive coatv is applied; said rubber solvent not only swelling the dispersed rubber peeling, autogenous weld or fusion between coats. 10 6. A method of smoothly coating a‘ rubber-im pregnated ?brous base, which comprises applying thereto as successive smooth coats a very ?uent aqueous composition. comprising water-dispersed rubber, water-soluble glue, a plasticizing agent ~15 for sa’d glue, and su?icient water-immiscible but particles and transforming them to a stickier state but softening an already applied and dried coat volatile rubber so vent to swell the dispersed rub ber particles ap reciably but short of inducing 20 fusion between coats. .. their coagulation; and drying the coats and tan 2. A method of smoothly coating a base which tning their glue content; said rubber solvent not 20 comprises applying thereto as successive smooth’ * only swelling the dispersed rubberparticles and transforming them to a stickier state'but soften-_ coats a very ?uent aqueous composition’ contain ing water-dispersed-rubber and sufficient water ing an already applied and dried coat/so as to ensure a non-‘peeling, autogenous weld or fusion 25 immiscible but volatile rubber solvent to swell the between coats. dispersed rubber particles appreciably but short _7. A method of smoothly coating a glycerinated,~ 25 of inducing .their ‘coagulation; and developing a. smooth multiple coating substantially devoid of rubber-impregnated ?ber base, which comprises streakiness and blotchiness by drying each coat in applying thereto as‘ successive smooth coats "a so as to ensure a non-peeling, autogenous weld or - 30 the presence of warm air before a successive coat is applied; said rubber- solvent the dispersed rubber particles very ?uent aqueous composition containing water- ' dispersed rubber, glycerine, water-soluble glue, and suilicient water-immiscible but volatile rub them to a stickier state applied and dried coat so as so, > ber solvent to swell the‘dispersed rubber par _ ‘ ticles appreciably but short of inducing their co. 35 peeling, autogenous weld or fusion between coats. . agulation; and drying the successive coats ‘and 3. A method of smoothly coating a base which comprises applying thereto as ' tanning their glue content; said rubber solvent not only swelling the dispersed‘ rubberparticles as and transforming them to a stickier state but softening an already applied and driedjcoat so as coats a very ?uent aqueous composition contain ing water-dispersed rubber, a water-soluble, ?lm to ensure‘ a non-peeling, autogenous weld or 40 forming substance compatible with the water dispersed rubber and capable of developing hard fusion between coats. ness and smoothness in said coats, and su?lcient " " 8. In- a method that involves applying a'very 40 \?uent aqueous composition containing water dispersed rubber as a succession of smooth coat 45 ‘but short of inducing their coagulation; and de veloping a smooth multiple coating substantially ings and drying the'composition between the suc cessive coatings, the practice of preventing, the peeling of the successive coatings which coni 45 prises‘ adding a water-immiscible but volatile rub ber~swelling agent to such aqueous composition containing the water-dispersed rubber in amount to swell the dispersed rubber particles appreciably but short of‘inducing their coagulation, said rube togenous weld or fusion between coats. 55 . ber-swelling agent not only swelling the dispersed 4. A method of smoothly. coating a base which rubber particles and transforming them to _ a comprises applying thereto assuccessive smooth "_stickier state but softening a previously‘ applied coating so as to ensure a _nonepeeling, autog 55 enous weld or fusiont betweenv coatings. v - 9. In a method that involves applying a very ?uent aqueous composition containing water . dispersed rubber and water-soluble glue-as a suc cession of smooth coatings and drying the com position between the successive coatings, the prac tice of preventing the peeling of the successive coatings, which comprises including in said com position in emulsi?ed form stabilized at least in 65 vpart by theglue'content of said composition a water~immiscible - but volatile rubber-swelling agent in amount to swell the dispersed rubber 70 to ensure a non-peeling, autogenous weld or fusion between coats. - particles appreciably but short of inducing their coagulation, said rubber-swelling agent not only swelling the dispersed rubber particles and trans ‘ forming them to a - 70 stickier state but softening a - 5. A method of smoothly-‘coating a base, which’ previously applied coating so as to ensure a non comprises applying thereto as‘ successive smooth peeling, autogenous weld or’ fusion between coatings. . coats a very ?uent aqueous'composition compris MILTON O.