[1]Uni'ted States Pateftt Office 3,169,033 TEXTURED FOAM SURFACE COVERING Paul C. Wetterau, Mountain Lalies, N.J., as.Rigiier to Can-olcum-Nairn, Inc., Kearny, N.J., a corporation of N,,iv@York 5 original application Nov. 18, 1957, Ser. No. 697,226, row Patent No. 2,918,702, dated Dec. 29, 1959. and this @)pplication Aug. 6, 1959, Ser. No. 832,017 3 Claims. (C]. 161-114) 10 Ti'iis invention r@Jates to flexible surface coverings which have a plastic decorative wear layer applied to a resilient foam back and particularly to a method of producing such coverings. This application is a division of my copending applica- 15 tion ffied November 18, 1957, and Vnic'n isstied D-,cember 29, 1959, as United States Patent 2,918,702. In accordance with present cominercial practice, flexible plastic surface coveriiigs having a wear layer containin,a a thermoplastic synthetic resinous binder, plasti- 20 cizers, piaments and fillers are widelv used as coverings for iloors, walls, vehicle interiors and the like in the form of sheets or tiles. Vinyl resins sucli as polyvinyl cY!orid-- and its copolymers, particularly vinyl chloride copolymerized with vinyl acetate, are most commonly used in 25 formulatin.- syntbetic resinous binder.s tised in the produc't,'on of such plastic surface coverings. NVhen resins are blended wifh plasticizers, pigments, fillers and the like and sheeted, products with excelle-nt wearing - properties and resistance to attack by ordinary household chemi- 30 cals are produced. These products have an unusual clarity a,-id brilliance of color, and the relatively low cost of vinyl resins make them ideally suited for productioi of surface coverings havin.- a lirge market. A major soarce of competition for products of this type 35 in the residential floor covering field is fron-i soft surface woven and tufl@ed carpeting, Carpeting has the desirable attribute of being soft and comfortable under foot. Plastic surface coverings of the type described above are hi.-hly fexibl@e and appreciably softer than wood or stone 40 Piooring materials, but they st-.Il do not pos8ess@the sbft- 1 ness and comfort of carpeting. Conseqaently, considerable work has been done in an attempt to impart to i'l"xible plastic surface cover.ings a high degree'of resili-,n6e. 41 A backing of felted fibers can improve the resilieiice of a plastic surface covering, but the de.-ree of ii-nprovement is mipimized when the felt is impregnated with waterproofing and stren.-thening saturan@s. Impregnation is reqiiired to inipart to the felt suiticienr, strength to withstand processing and to improve di-rnensional stab-ility in 50 the prese-@ic@ of nioisture. Felt backed surface - coverin,-s also have the disadvantage that they tend to become permanently deformed when subjected to heavy loads due to tl-ie poor recovery properties of the felt. Products with . gr6atly improved resilience have - b.I.In r)5 made by the aD licatioii of a 'thin foam rubber layer to @ -P the back of a flcxible plastic siirface coverirg. This product is convention,ally niade by the application of a foamed rubber latex to the felt backing of the felt-backed plastic 6C) surface covering. Since this product has an intermediate felt layer, it tends to suffer from the inherent disadvantage of all f@-lL-backed products, thtt is, poor recovery afterr-@iiioval of a heavy load. Also, the presence of an interinediate felt layer presents a potential area of sus- 65 co tib; @p Iity to delamination. A plastic surface covering can be directly laniinated to thin foam rubber by means of a@l adhesive to produce a highly resilient product, but this product also has the weakness of being susceptible tb delamination at the adhesive bond. 70 A further desirable attribute of ca'rpeting is its threediniensional textured appearance. The conventional flexPatented Feb. 9, 1965 ible plastic surface covering has a smooth glossy appearance. Such a product is highly desirable installed in certaiii locations but there are areas and decorating styles that are suite@ to the iise of a textured-surface product for both floors and walls. The imparting of texture to a flexible plastic surface covering has been attempted by @,e varioiis techniques of embossing, but these, in general, have not proved too satisfactory and reqi-iire the use of expensive embossing ro]Js. It is an object of the invention to produce a plastic surface covering having resilience under foot coupled with a textured appearance. Another object of the Invention is to produce a highly resilient textured-surfaced plastic product having resistance to delamination. In accordance with the invention a decorative textured resilie@it plastic product is produced by applying a decorative plastic I-,tyer to a gelled founalole plastisol compositioii base and thereafter heating the mass to foam the plastisol and 'LlIse the resins iii both layers into an integral u@iitary sheet. The invention is illustr,-Lted o@i the accompanying drawings wherein F-,ZGURES 1, 3 a-@id 5 show schematic representations of three embodiments of the production of a textured resilient plastic surface covering iq accordance with the inve@at,:on and Fl;-3URES 2 and 4 are enlarged views of the product produced by t.'qe niethods illustrated in FIGURES 1, 3 and 5. With reference to FIGURE 1, a thin endless carr,er belt 1--a is drive of foa' n around rolls 12, 13. A mass mable plastisol coi,-Position 14 is forilic@l i-,ito a layer 15 haviiig contr6i'led thickness by means of a doctor blade 16, The forn-ed lay@-r is ca.Ti@-d by the motion of the e,.idiess belt through a hot air'oveq 17 @vhereiri th-, i)lastis6i is -@elled. A mass of foanable resinous compo-sition 13 is fornied ir@to a layer 20 ofcontroiled ti'll-,knc,-s ori top of the gelled plastisol -layer by m,-ans of a doctor blade 21 and the r,-sulting con7iposite r,,- @ass is passed throu,oh a hot air fusion ovei 22 wherein the gelled plastisol layer foams aiid the resins in both layers fuse, tliere-. by bonding both layers together. A foariied plast7@sol layer 24 forms the resilient bac@'cing for the T)rodtict 26 and gas niigratio-,i i,.it6 the tipper iayer imparts texttire Lhereto, form@ ing an upper textured layer 25, as illusL@-,ited in greate@- detail in FIGURE 2. The upper layer is cracked and discontinuous in areas, expos;.ig the to-,ver fopnied layer to view. In the embodiment illustrated in FIGURE 3, a two layer sheet is forined as des@ribed above in referetice to FIGURE 1. The temperature in the fusion olen 22 is controlled so that the resins ii the product fuse ard the gelled plastisol layer partially-but not compleiely foams. The product bearing a decorative layer 29 fornied and fused on a partially foamed backing layer 27 is inverted so that the decorative layer is car,,ied on ari endless cprrier bel,t 30 driven by rolls 31, 32. The co mposite sheet passes throu-h an oven 33 maintained at a '@emr,@-rattire sufticient to coniplp-te the foaming of the layer 27. A composite product 36 bearing a plain loamed layer 34 and a decorative layer 35 having a sli,,htly textured appearance leaves the oven 33 and passes to storape. As illustrated in FIGUP@E 41 the decorative layer has a slight three-diniensional appearance in the form of small protuberances extending above its surface, but is not cracked and ilssured as is the product illustrated in FIGURE 2. In the embodiment illustratcd in FIGURE 5, the decorati-,re layer is @applied by pri@iting on the @elled plastisol de,?)osited on the belt in the same inanner as recited above for FIGURE 1. A IOOP 40 between rolls 41, 42 creates slack in the systein so that continuotis sheet moti(n tlirough the oven 17 is converted to interinittent motion ne@,essary for the printing operatioii. Printing blocks 43, 44, 45 apply a decorative layer,46 to the gelled plastisol
[2]layer. The printing blocks ,,re associated with p,,iint pots 47, 43, 49 which a-pply a iilm to the printin.- blocks prior to priiitin,-. A loop between rofls 52, 53 creates slack so that interw@ittent sheet motion duritig printing is coiiverted to continuolis sbeet motion throu.-h ti-ie fusion 5 oven 2'@'. A product 56 cor-iprisin.- a printed decorative textured sur'ace layer 55 and a foam backinleaves t@ie fusion oven and passes to storag--. The decorative ltyer is cracked in the sam@- Pianr@er as the product of FIGURE 2, difierin.- only in being nralti-colored in the form 10 of a printed desi.ati. In operation, the belt is driven continuously by roll 4,1 and interfaittently by roll 52, @vilh loops 40 and 51 providin-. means for converting the sh-.et motion. Wlien the sheet is in mo'cion in the pr,@'nting section, the paint 15 pots reciproca@le lo,.igitlidiiially beneatli the printing blocks I and deposit a film of paint on the printing sur'aces of the blocks. The shea motion stops and the prin,in, blocks are depressed orto the gelled plastisol, thereby depositing a decorat'@'ve film thereon. Each blociz Prints 20 a difterent color in the conventional maniier of a fl,tt bed priiiting machine. The carrier belt upon which the foamable composilioil is kdllid in acco@-dance with the invention preferably has ona smooch polished surface. It can be coated with a c 25 ve-@itional re"easi-@ig iluid, such as a silicone, a wax, heavy metal salt oi a high n-iolecular weiglit falty acid, such as alurniiium stearate, zinc pairritate and the like. Altern,,itely, a 'chin layer of -,I release paper, that is a paper sheet impregnated witl-i a release fluid, can be placed on 30 ",'le carrier surface and the foamable cor@iposition applied t'ilereto. In some cases, @io releasing medir@m need be used ii !he carrier sarface is thorouehly cooled prior to the stripping of Vii-. product therefroin at the end of the process. 35 The carrier surface can be in the form of an endless belt as showii on the drawin-, where a surface covering is 1)roduced in a continuous pro-,ess. The carrier surface can aiso be in the form of a slab or other appropriate configuration if desired. Metal is th-. preferred material 40 since a metal carrier is strong and durable, yet flexible. The carrier can also be f6rmed of other miterials, such as plastic, rubb--r and the like. The carrier must be able to withstand temperatures iip to about 450' F. without being deforrr@ed and should be flexible for a continuous 4ti process. The base layer wbich is initially applied to the carrier belt is a layer of foamable res-'@nous compositioli. Suitable foamable compositions comprise a thermoplas*lic resir,ous b-inder and a substance which is decomposed by 50 lieat to yield a foam producing -,as. Tne resinous binder must be one that is coalesced or fused into a continuoil-s filra by the appli catio,-i of heat, The preferred resinous binders are the vinyl resins, but other thermoplastic resins can be used such as polyiiiers and copolyrners of acrylic 55 acid and methaerylic acid and their derivatives, polystyrene, polymetized methyl styrene, polybiitadiene and the like. The foai-nable resiiious con-iposition is most conveiii-,ii',Iy appliecl. as a Jiquid wliic@h is doctored o@- otherwise Ljplied to the carr,'@er in a controlled tliickncss film, 60 ,is illustrated iti FIGURES 1, 3 and 5. For liquid applicatio@i, the resinous bincl.-.r and blo@vina,-ent are dispersed in a dispersion inedium. The resinous binder and blowing age-@it can be dispersed in water io form an aqtieous latex, but the preferred dispersion medium is a fluid 65 plasticizer for the therm(@,niastic resin. Si-ich a dispersion oi' res;-ii in a plastic@@zer is conventionally terined a plistiSol. A plaf@tisol is a uniform dispersion in a pi,- tsticizer 2of 70 a ther-inoplas,ic resin iri the form of fine partiel@-s. Sriall aiiiounts of pi.-m@iits and stdbilizers can b@- p,res-- nt. A pl-,stisol has appreciabl-, -@qui(lity at nor@mal rooin t-.mpcrq@tures but is converted by licat into a flexible, bard i r Lhe mop I lastic, mas's. This ultimate -result is brought about 75 by the pi-oce@ss of fusion ticized and solvated by the plaslic'izer. @ I PolYmers of vinyl chloride have been found t6 be pirticularly effective il foi-nitila;tina pla&tlsol compositions for use in 'he invention. The vinyl chlorid-e pojyiiiers can either be simple, unmixed homopblyiiers of vir@yl chloi-ide orco,3oiyrrers therof in @which ;the CISsential polynieric s,trllctur' of POIYvinyl c'nlorld-, is interspersed at intervals with @the residues of othe,.r et,ayienic,@lly unsatiirated ebr@ipOLinds copolymerized therewi,h. Ttie ess--ntial properties of the polyin,-ric stricture of polyv@Inyl clilorid,- viill be i-etained if not mi ore tha.Ti 40 percent of another monorier is copolymeriz,-d fa,rein. Suitable monomers include, for instance, vinyl esters on the order of vinyl bromide, vinyl fluoride, vinyl acettt-., vitiyl chloroacetate, vinyl butyrate, o@tlier fatty acid vinyl esters, vinyl alkyl sulfonates, trichloroetbyle ne lpd the like; vinyl etli@zrs .- ,,ich as vinyl ethyl ester, vinyl isoPropyl ethers, vinyl chloro@-tliyl ether and the like; cycl@ic unsaturated compounds such as styrene, th,- mono- and polychlorostyre-les, coiir,,@7@iaron@-, indene, vinyl naphthaleiies, vinyl pyridines ' @inyl pyrrole, ard the lik-,; acryee acid ard its doi-ivatives such as -,tl,@yl ar-ryla'.,e, methyl -riietliacrylate, ethy-I 1-nethaerylate, ethyl c,@loroacrylqte, acrylonitiile, m.-thacrylonitTil.-, diethx, I ir@alF-@at@-, diathyl fliniarate and the like; vinylidetie compoun ds on &,e order oj' vinylidene chloride, vinylidene bromid-,, vinylidene fluorochloride and the, like; unsaturated hydrocarbons such as ethylene, propylene, i,sobute@le and ,he lile; allyl @coiipound@. such as al]Yl acetate, ally! chloride, -@ll]Yl etliyl either and the like; and coniugat-,d and crossconjugated ethylenictily unsaturated comp6unds slch as butadier,.e, isoprene, cliloroprene, 2,3- dirnethylbutadicne1,3, piperylene, divinyl ketone and the like. Resins adaptable for use in formulatin@ vin3il chl 0- Tide plastisols are com'monly referred @to as disi,,-@rsion gr'@ide Si-ich res:ins are available havina parlicle sizes Of from 0.02 to about 2 m I icrons in contra,,t to calender grade vinyl chloride reslls which are avaiiabl@e in partiCIes ran,@ing up to 35 microis in size. D,1',sper-ion grad.- resins are usually of high,,r molecul-r w--iabt than calender grad,- resins a-lid bave parti@le surfaces of a. bard, horny nature. @Polymers of vin@,l chlo,ride having specific viscosities above abolit 0.17 and preferably between 0.17 and 0.31 as n-icastired in a solution bf 0.2 gram of rf-,si,,i ii loo r@lilliliters of ni-trobenzere at 20- C. %,e particularly effec,'.ive. In the determinatio-@l of spp_ciic viscosities the sample of resin in n;trobenzene soltition main@Lained at a t,-m'perature of 20' C. is allow@-d to flow btween two ca-librated i-narks in a Pil)ette and tirne reqlaired -is recoxded. This time ' is compared with the time requi@red for a control Of Plire nitrobenzene solvent to pass between the same tivo rnark-s, also at a temperature of 20' C. the spe@-jill-, viscosity is determined as the samt)le flow 'Lim d@ivicled minis 1. The specific viscosi,ty is an effective ineasure of @relative molec uiir wei,@ht of the polymer, the higher th.- specific viscosity@ the iiigher being the molectilar @vei,@"It. lu ithe f(rfli@lation bf plastisol compositions for use ill the invention, tl-ie fine particle size resin is unifortnly dispersed in liqliid plasticizer. The fluidity of plastisois is influencffd in patt by the.par@ticular Tesin @sel@@cted b,.lt is also a function of @the ratio of plasticizer to resin. Plastisols b,-cO'rP- less flziid as the ratio, of plasticl'zer is reduced. Plastisols, for tise in the inv tion conlain froni aboiit 50 to ib6tit 150 part@ plasticizer per 100 parts resin. Tlle fluidity Of Plalstisols can also b-,- controlled by the addition of small amounts of a vola-lile diltient not exceeding abOLt 10 Pe-rcent o't the corlpositioti by weight. '-@Liitable plastisol conipositions for the preparati,-ii of bas,,3 layers for use in the inventio-@i have a vis-@osi@ty of about 200 to about 25,000 Conti 'Isured with POises as me, the resin bacomes plasby,the cont@o@l flow tim.e . e
[3]a Brookfleld viscoi-i@,ter Lisip..- a number 6 spindle at 10 r.p.m. Plastisols within this viscosity range can be formed into a controlled thekness film by means of a doc,tor blade. Plastisols having higher viscosities can be used although the high viscosi-ty neressitates the use of a technique such as calendering for film formation. The selection of the plasticizer is important in determining the strength and flexibility of the wearin.- Surface of the product and also in influencing the viscosity and viscosity stability of the plastisol. Esters of strai.-ht and branched chain alcohols with aliphatic acids impart low viscosity and good viscosity stability to a plastisol. Typical plasticizers of this type include dibiityl sebaa@ate, dioctyl sebacate, diogtyl adipate, didecyl adipate, dioetyl azelate, triethylen,- glycol di(2-ethylhexanoate), diethylene glycol dipelargorate, triethylene glycol dicaprylate and the like. Plasticizers of the aromatic type, -su,ch as est,ers of aliphatic alcohols and aromatic acids or aromatic alcohols and aliphatic acids or aromatic alcohols and aromatic. acids can be used although the use Of hi,@hly aromatic plasticizers is limit--d by thoir tendency to yield plastisols of high viscosity. Typical plas;ticizers of tMs typ,e include dibutyl phthalate, dicapryl phthalate, diactyl phthalate, dibutoxy ethyl phthalalte, dipropylene glycol dibenzoate, butyl benzyl sebacate, dibenzyl se-bacate, dibenzyl phthalate and the like. Other types of plasticizers, such as esters of inorganic acids, including trieresyl phosphate, octyl diphenyl phosphate and the like, alkyd derivatives of rosin, chlorinated paraffine, hi,-h molecular weight aromatic hydrocarbon condensates and the like can also be used. Th-- plasticizer or blend of plasticizers is chosen to yield a plastisol of the desired viscosity and foamin,@ characteristics. In addition, the plasticizer should have a low vapor pressure at the temperattires required to fuse the resin. A vapor pressure of 2 millimeters of mercury or less at 400' F. is satisfactory. Minor amounts of stabilizers which are incorporated to reduce the effects of degradation by light and heat ,ire present in the composition. Suitable light st,,ibilizers include resorcinol disalicylate, resorcinol dibenzoate, phenyl phthalate, phenyl benzoate, o-tolyl benzoate, eugenol, guaiacol, onitrophenol, o-nitraniline, triethylene glycol salic@late, and organic phosphates apd otlier complexes of such metals as barium, cadmium, strontium 1 lead, tin and the like. Stiitable heat stabilizers include sulfides and sulfites of aluminum, silver, calcium, cadinium, magnesium, cerium, sodium strbntrium and the like, glycerine, leucine, alanine, 0- and p-amino benzoic and sulfanilic acids, hexamethylene tetramine, weik acid radicals including oleates, recinoleates, abietates, salicylates and the like. Normally, the plastisol contains from 0.5 to 5 parts stabilizer per 100 parts resin@ The particular slabilizers chosen shoiild not , impart excessive viscosity to the printing composition. The foamable plastisol composition for use in the invention contains an effective amount of a blowing agent. The larger the amount of blowing agent within practical limits used the greater is the expansion of the foam. Foam densities of froni 10 percent to 50 percent of the density of the unblown plastisol can be readily attained. Such results are attainable with from about'l to about 20 parts blowing agent per 100 parts resin with from 2 to 10 parts blowing agent per 100 Parts resin being particularly effective L'Or the production of foams Of a density which are most desirable for use in producing surface coverin.-s in accordance with the invention. Complex organic compounds which when heated decompose io yield a-@i inert gas and have residues which are compatible with the resins in the plastisol are used as blowing agents. Such materials have the property 6f complete dec6mposition over a narr6w temperature range 'which is particularly desirable for obtaining a good foam structure. Co-mpounds h@ving the >N-N< and - N=iN- linkages decompose at elevated temperatures 3,169,088 to yield an inert gas high in nitrogen. Typical compounds include substituted nitroso compounds, substituted hydrazides, substituted azo comrounds and the like, such as are tabulated below. 5 Blowing agent: Decomposition temperature, ' P. P,P'-oxybis-(benzenesulfonyl hydrazide) - 300-320 N ,N'-difnethyl-N,N'-dinitroso terephthalamide ---------------------------- 200-220 10 Dinitrosopentamethylenetetramine ------- 355-375 Azodiformamide --------------------- 370-390 Blowing agents for use in the invention must be decomposed at a temperature below the decomposition temperatlire of the resin used. Therefore, in the case 15 of plastisols formulated with the preferred vinyl chloride polymers, a blowing agent decomposing below 450' F. must be used. The minimum initial decomposition temperattire must be sufficiently hi.-h that no premature gas evolution occurs during formulation of the plastisol and 20 subsequent processing. Any prenature decomposition of the blowin- agent renders the application of a uniform layer to th'e carrier difficult. In addition, the minimum initial decomposition teniperature of the blowing agent should be above the temperattire at which the plastisol 25 attains some strength throu.-h gelation. In the case of the preferred vinyl chloride polymer plastisols, the minimum initial decomposition te-nperature of the blowin.auent should be at least 200' F. The use of a blowing agent which does not begin to 20 decompose until the fusion temperature of the polymer is particularly effective in the prodliction of products in accordance with the ini,ention. When a high teMDerature blowing agent of this type is used, such as a-zodiformamide, the decorative ai3d base layers of the product 35 become integrahly bonded together into a unitary sheet prior to any foaming of the base layer. This affords better control of the texture produced in the decorative layer by the evolution of gas, since the resinous compositions have attained greater strength through fusiol. 41,) In accordance with the invention, the foamable plastisol cornposition containing a blowing agent is applied to the carrier web either as a Jiquid which is doctored or otherwise coated into a thin film or as a Dreformed slieet. When a film is applied by -oating, the composition is 45 heated in order to gel the plastisol so that when subsequently cooled it will have sufficient strength and ri.-idity to permit application of a decorative layer. This gelling step is normally carried but in a conventional hot air oven rnaintained at a temderature of about 200' F. in 50 the case of a preferred vinyl chloride polymer plastisol. In the oven a rat)id flow of the hot gases around the sheet insures tha-t the entire sheet attains a uniform teniperature. Normally, residence in the hot air ove-@i from about I to about 5 mi,.iutes will insure satisfactory 5,5 gellation of the plastisol. The foaniable plastisol can also be applied to the carrier base as a preformed sheet produced by any conventional sheet forming techniques. For example, a plastisol composition contain-ing a blowing agent can be .@elled and then calendered into a smootli 6( uniform sheet. Alternately, sheet formation can take place in a press. It is iinportant that the coroposition not be subjected to excessive temperatures during sheet for@ matibn to prevent premaiure decomposition of the blowing agerit. 65 The gelled plaslisol layer is cooled and the decorative layer is then applied thereto. The decorative layer can be applied as a liquid film, as for examp]6, by printing or doctoring or can be applied in the forr@i of a preformed decorative sheet. The doctoring of a liqtiid com70 Position is a convenient method of applying a decorati've layer when a solid color eitect is desired. Printing cati be used When a more intricate decorative effect is to be created. The appJicatiOn of the decorative Jayer in the form of a preformed decorative sheet is desirable -- Aihen a 75 'relatively thick wearing surface is desired.
[4]NVhen the decorltive layer is applied as a liquid film, it can be in the for,,n of either a pigrnented plastisol or organosol compos-ition. The coiiiposition should be compatible with the gelled plastisol base and accord,ngly, it is preferred that the resinous binc'@er ii the decoralive 5 layer be a polymer or copolymer of vi-@iyi cl-iloride as described in connection with the pl-,istisol compositio,,i -ibove. -i A compos;f on adaptable for applic,@ition as a llqtiid film w@41 normally have a viscosity at 25' C. o" from aboiit 200 to 25,000 cen,ipoises as measuced with 10 a Brookfield viscometer using a No. 6 spiyidle @ill O A suitoble plastisol compri8es from 50 to 150 parts plasticizer per 100 parts resin. @lasticizers a-@id mixttites Of pla@tl@izers as describdd in connection witli tile plastiso@l ba@e layer are useful in formillatir@g a plastisol 15 decotative, composition. The composition @,lso @Ont,iins he.it and light stabilizers as desd.-ibed abov.- ard is p4@,amented in accordance with the particular celbr O@esirod. Any of the orga-@iie and inorganic pigmer@ts which are normally used in connection with pi.ornerited resinous 2( compositions are uset'Lil in i'Orming a decbrat,',Vc plasL:Isol. A decorative fltiid film can also be formlilated as an organosol, which is similar in na,Urc to a pl,,tstisol exc,-r)t that a portion of the plaslicizer is replaced wit'@a a volatile organ@@c solven". The resin in an organosof is pr,-sent in 25 the form of finely divided particles uniformly dispersed throughout th-- coinposition in the same manr@er as the resin is present in a plastisol. In formulating an organosol for use as a d-,corative I-,iyer ii accordane-@ with @the iiivention, it is preferred 30 that the resin be a polyner or 1 copolymer of vinyl chloride as described ii, connection witn the plastisol base layer. This insures max-imum con-ipatibility alid adhesion between the layers in the iinish-,d product. Useful organosols contain from about 2(@ to 15 about 150 parts plasticizer per 100 parts of resin, aiad 0 any of the plasti-.izers or mixtures of plasticizers described in connection with the plastisol base layer are useful. The organosol con-iposition also contains from about '. to tbout 80 paris of volatile organic solvent per 40 100 parts of resin with the amount chosen in accordance with the particular viscosity desired. Such solvents as xy,lene, tolu.-ne, c3rclohexanone, methyl ethyl ketone, methyl isobutyl ketone and the like are useful. The organosol also contains minor amounts of heat and light stabilizers as described in coinection with the plastisoi 45 bp@se layer and contains sti;table pigments in accordanc@ with the particular color desired, The organosol or plastisol decorativ,- layer can be appl;ed either by a doctor blade or o,h-@r conveitionell coating ecillipment or by any of the conventional tech50 niques of printing. When a multicolored decoration is applied by prin,ing, a separate batch of fluid plastisol or organosol composition must be formulaled in each bf the colors to be used. Prinling can b-. by eilher flat bed or rotary printing techniques. When a flat bed prtrt55 in-, niachine is used of the type well known for the manufacture bf enamel surface printed felt base floor coverings, the contintious sheet motion necessary before and after the printing operation must be converted to the (30 intermitt-,nt motion required dtiring printing. Continuous motion be.fore and after is requir,-d iii order that the plastisol gelling and product fusing and foaming operations can be ad@-quately co@-itrolled. Variotis slack loops or festooning systems can be used in I order to make ttiis conversion. 65 Whe-@l a relatively thick decorative layer is desired in the finished product, it is vsually preferable to apply it in the form of a preforn-ied sheet oj' resinous composition. The preform-,d sheet can be fornied by any of Viae TO convention,d techniques of plastic sheet formation, such as calendering, pressing and th-- like. Alternately, a fluid film@ , as for e--ampl@-, a plastisol or organosol, can be cast upon a surface and then gelled in order to attaiii suff,cien.t m.elc4ani.cal strength to be handled as @a sl@l,et- 75 8 When a resinoiis compc,.-ifior ;s ',o be ai)plied as a d--corative 1,,iyer in the form of a prefor-.iied s@ec',, it is preferred that the resiiious binder b-, a polymer or copolymer of vinyl chloride as describ,-d in corne,-tion with the plastisol base cor@iposition. N),7hen the sheet is to be formed by calendering or press-.ng, a pi.-mented viscoiis plasti-.ol can b@- used or a filled vinyl plastic co@mposition of the type disclosed in Pat-@iit 21558,378, which ist,,ed to Robert K. Petry on Jur@e 26, 1951. The composi'Le sheet compr@'Sing the gelled plastisol base a@n.'t the decoralive layer applied thereto is 12eated in order to foam the plastisol base and i.Use the compositions of ihe two layers into a un-itary sheet. It is necessary that the product b,- heated to the fusion tem-oerature of the resinous compositions used and also to, a sui--iiciei-itly h,'@gh temperature tiiat the blowidg age-@it in t-@l-.e plast;sol base is decomt)osed. Dep-- nding on t'iie decomposit;on temperature of @'he partictilar blowin,a agent used foaniing can either occur befor-- fusion, simultaneously witli fusion or alt.-r fu8;on. It has been found particularly desirable to use a high temperature blowing a-ent in the plastisof base compos@@'tion for opt-I.-lum control of foam structure ind prodilict texti@re. Under these cotditions, fo,,iming does not occir until the resino-,.js corl@lpositions hlve beer@ substaTitial'.,y coi-@ipletely fased. in accordance with one embodiment of the invention, th-, composite sheet can be passed dir,-ctly to the fusion oven after the application of the decorative layer. The temperattire in the oven can be controlle,d so that complet@- deconiposition o'l the blo,ving agt@lit occurs. In another embodiment of the invention, the tei-nperature in the oven is controlled so that fusion is comuleted but only sli.-ht or no decomposition of the blowing agent is effected. The ftised product is then removed from the carrier belt, inverted and placed on a second mov@ng carrier belt with the gelled and ftised plastisol base layer facin.@ upward. The sheet in this condition is then passed through a second ove-@i wherein the blowing agent is coftipletely decomposed. In accordar@ce wilh the first ew@bodiment, the gas liberated by the decomposition of the blowiii., agent not o-iily expands and foam3 the b,,ise plastisol layer but also migrates into the decorative layer imparting a textured effect thereto. When an organosol having a relatively low proportion of plaslicizer to resin is used, the decorative layer can actually crack to form fissures tlirou.-h which portions of the base foamed layer protrudes, giving a most unusual appearance in the product. In accordance with the seco-@id embodim-ent of the invention, decomposit@.on of the blowing agent liberates gas dir@_ctly idto the udward facing layer Vnich is actually to be the base layer of the filiished product. Thus, only a minor amount of gas is effective in the downward facing decorative lay.-r so that the textured effect in the prodlct is miniinized. The textured effect in the second embodiment is limi,ed to a plurality of small protuberances extending above the surface of the decorative layer. The following examples are given for T)urDoses of illustration: Example I A foamable plastisol was formulated by grindin.- the following formulation on a conventional three-roll mill: Parts Vinylidene chloride-vinyl chloride copolymer ------ 40 Polyvinyl chloride ----------------------------- 60 D@'decyl adipate ------------------------------- 60 St,,tbilizer ------------------------------------ 3 Finely divided titanium dioxide ----------------- 2 Azodiformai-nide blowing a.@ent ------------------ 3 This composition was applied to a polished metal surface as a film 0.006 inch in thickr@ess. The film was placed ill an oven at 225' F. for 2 minutes to gel the plastisol and the sheet was cooled to room tfrhperature by exposure to the atmosphere.
