Process for treating fabrics and fabrics obtained therefrom
United States Patent Gregorian et al.  
 [ Apr. 29, 1975 PROCESS FOR TREATING FABRICS AND FABRICS OBTAINED TI-IEREFROM Inventors: Razmic S. Gregorian, Aiken, SC;  
 I-Ians R. Hoernle, Augusta, Ga.  
 Assignee: United Merchants and Manufacturers, Inc., New York, NY.  
 Filed: Dec. 11, 1973 Appl. No.: 423,683  
 Related U.S. Application Data Division of Ser. No. 209,456, Dec. 17, 1971, Pat. No. 3,797,996.  
 U.S. Cl 8/ll4.5; 8/130.1 Int. Cl D06m 15/20 Field of Search 8/114.5, 130.1; 156/84,  
 References Cited UNITED STATES PATENTS 3/1938 Castles 28/1 2,239,914 4/1941 Heberlein 8/114.5 X 2,245,289 6/1941 156/84 X 2,390,386 12/1945 Radford 8/l30.1 X 3,079,212 2/1963 Fountain et al 8/114.5 3,238,595 3/1966 Schwartz et al.. 156/85 X 3,553,066 1/1971 Cavalier et al.... 156/84 X 3,622,434 11/1971 Newman 156/85 X 3,692,603 9/1972 Rhodes 156/85 Primary ExaminerLeland A. Sebastian Attorney, Agent, or Firm-John P. McGann, Esq.; Jules E. Goldberg, Esq.  
 [57] ABSTRACT 8 Claims, No Drawings PROCESS FOR TREATING FABRICS AND FABRICS OBTAINED THEREFROM CROSS REFERENCE TO RELATED APPLICATIONS This application is a division of copending application Ser. No. 209,456, filed on Dec. 17, 1971, now US. Pat. No. 3,797,996.  
 BACKGROUND OF THE INVENTION 1. Field of the Invention This invention pertains to the field of finishing treatments for fabrics. More particularly, this invention concerns methods for chemically affecting unusual texturi zation and color effects in three-component fabrics having a. facing component of upstanding fibers, a backing component and a water-insoluble interlayer securing the facing component to the backing component.  
 2. Description of the Prior Art The use of chemical shrinking agents to shrink woven and non-woven fabrics is known. Techniques for applying such shrinking agents as well as the preferred shrinking agents for various types of textiles fibers are also known. (See for example Bull. Inst. Textile France No. l02, pages 871-885 (1962).  
  A type of fabric to which such chemical shrinking techniques have not normally been applied are threecomponent fabrics. Such fabrics are generally composed ofa facing component as hereinabove described, a base or backing component which provides the fabric with its structural strength and a water-insoluble interlayer, usually an adhesive substance, which interlayer secures the facing component to the backing component.  
  Because ofthe three-component nature of such laminates, the texturization processes used heretofore have been limited generally to physical methods, such as, for example, mechanically cutting, compressing or compacting areas of the upstanding fibers of the facing component. These methods, however, tend to require complicated equipment resulting in relatively high production costs.  
 SUMMARY OF THE INVENTION We have discovered a new three-component fabric comprising a facing component of upstanding fibers, a backing component; and a water-insoluble, substantially continuous interlayer disposed between the facing component and the backing component and securing the facing component to the backing component wherein either the backing component or portions thereof, the entire facing component, or both the entire facing and backing components are shrunken.  
  Additionally, we have discovered that by using a napped backing component, highly unusual and desirable effects may be achieved by using both chemical and non-chemical shrinking techniques.  
 DESCRIPTION OF THE PREFERRED EMBODIMENTS The fabrics which are subjected to the process of the present invention comprise essentially threecomponent laminates having a top or facing component, a backing component and an interlayer component anchoring the facing component to the backing component.  
  The facing component may be any type of upstanding or raised fibers, including single fibers as well as fibers in the form of loops and the like. Suitable materials for use as the facing component include rayon, cotton, nylon, polyesters, wool, mohair, silk, acrylics, modacrylics, and the like. The type of textile material used is not critical so long as it can be shrunken.  
  The most well known form for the fibers in the facing component is that of a flock which comprise short fibrous or filamentry material generally less than a onefourth of an inch in length. This flock is usually deposited upon an adhesive coated base. However, as noted hereinabove, the fabrics of the present invention include those having facing components which would not necessarily be within the description of flock generally known to the skilled art worker. For example, the raised fibers may be looped, or longer than a conventional flock material. Thus, types of fabrics which are suitably within the framework of the present invention are velvet fabrics, flocked fabrics, wallcoverings, etc., carpeting or other types of three-component floor covering, etc.  
  The production of flocked fabrics are well known to the art (see for example US. Pat. No. 3,079,212 incorporated herein by reference).  
  The backing component is a flexible backing and may be made of materials, e.g., polyvinyl and urethane films; woven and non-woven fabrics, and fabrics composed of cellulose-based fibers, e.g., rayon or cotton, and synthetic and natural fibers. Particularly preferred blends are those of cellulose-based fibers, wool, mohair, silk, acrylics, modacrylics, and the like.  
  Desirably the backing component itself has upstanding fibers such as in the form of a nap or pulled loops. Such upstanding fibers are very short, generally having a length in the range from about /2 mm to 20 mm and most preferably about 1 mm to 2 mm, although fibers as long as 2-3 cm or longer may be used.  
  The use of a backing component having such raised or upstanding fibers produces particularly desirable effects when the interlayer is adjacent to it, i.e., the interlayer contacts the napped side of the backing component.  
  Suitable materials for the interlayer component include adhesives normally used to bind fibrous material to backings. Such adhesives are generally classified as water base and solvent base adhesives.  
  Water base adhesives consist of a binder, generally an emulsion polymer, and a viscosity builder. They may also contain plasticizers, thermosetting resins, curing catalysts, stabilizers and other additives well known in the art.  
  The emulsion polymers generally used include acrylic, vinyl-acrylic, vinyl, urethane and styrenebutadiene latexes. In order that the upstanding fibers be held in the desired position until the adhesive is fully cured, it is generally necessary to raise the viscosity of the latex to about 30 to 100 thousand centipoises. The viscosity is dictated by the nature of the backing and the method of contacting the upstanding fibers with the adhesive layer. For example, where the backing is a loose weave fabric and the beater bar method is employed, a viscosity of from to thousand centipoises or higher will be necessary to prevent undue penetration of adhesive into the backing which would result in a boardy hand and would leave insufficient adhesive on the surface to securely bind the fibers. On the other hand where a relatively impervious backing is used, a much lower viscosity, e.g., about 20 to 30 thousand centipoises is sufficient.  
  Suitable thickeners include water soluble polymers such as carboxymethyl cellulose, hydroxyethyl cellulose, polyoxyethylenes, and natural gums as well as alkali swellable polymers such as highly carboxylated acrylic emulsion polymers.  
  Plasticizers may be added to alter the hand of the finished goods or to improve the flow and leveling characteristics of the adhesives. Where the primary goal is the latter, fugitive plasticizers such as the phthalate esters may be employed. lf the intent is to alter the hand of the finished goods, then more permanent plasticizers such as low molecular weight polyesters may be used.  
  Thermosetting resins such as methylol-melamines, urea formaldehyde condensates or phenolformaldehyde condensates may be incorporated to improve durability or abrasion resistance of the finished goods.  
  Catalysts such as oxalic acid or diammonium phosphate can be used to increase the rate of cure of the adhesive.  
  More specialized additives include ultra-violet absorbers where the backing, such as urethane foam, is subject to photo degradation and dyes or pigments to impart a color to the adhesive layer. When a breathable film is desired, adhesives may be chemically or mechanically foamed.  
  Solvent adhesives include both fully reacted soluble polymers such as acrylic homo and copolymers, polyesters, polyamides, or polyurethanes and two package systems such as polyester polyols with diisocyanates or isocyanate prepolymers and epoxies with polyamines. The polymer or prepolymer is dissolved in a suitable solvent which is preferably low boiling, and then thickened to the proper viscosity in a manner similar to that used for the water base adhesives. Catalysts, crosslinking agents, stabilizers, pigments, or dyes may also be incorporated.  
  The texturized laminate of the present invention may be prepared by first applying a shrinking agent to the desired component of the laminate. The shrinkage agent may be applied in the form of a paste composition by printing. Methods for formulating such pastes as well as the printing thereof are well known in the art. Thus, for example, the printing may be carried out on conventional color and dye printing machines, such as, rotary screen, silk screen, rollers, etc.  
  Alternatively, the shrinkage agent may be applied by spraying, or dipping. Such spraying and clipping techniques are also conventional.  
  Many types of well known chemical shrinking agents may be used depending on the nature of the fibers comprising the component to be shrunken and the other components of the laminate. Thus, it is understood that the shrinking agent should be a material which will not chemically attack either the interlayer or the component which is not being shrunken. Moreover, in all cases, the residue of the shrinking agent should be readily removable in a back washing step, such as, for example, a mildly alkaline back wash which would be used to remove acidic agents from a facing component made of nylon.  
  Additionally, shrinking agents should be avoided which would readily diffuse through the adhesive layer or cause a weakening of the securement of the facing component to the backing component.  
  When the component to be shrunken is nylon, the shrinkage agent should be an acidic material having a dissociation constant greater than about 2 X 10*. Suitable acidic materials include strong mono and polybasic inorganic acids and organic acids having the formula R-COOH wherein R is hydrogen, lower alkyl having 1- to 5 carbon atoms or halogen substituted lower alkyl. Particularly suitable acids include acrylic acid, formic acid, monochloroacetic acid, dichloroacetic acid, alphachloropropionic acid, bromoacetic acid, tricluoroacetic acid, o-chlorobenzoic acid, 3, 5,-dinitrobenzoic acid, sulfonic acids, such as, p-toluenesulfonic acid, benzenesulfonic acid, and phenols, sich as, m-cresol, and p-chlorophenol.  
  The mineral acids, such as, hydrochloric and sulfuric acids are also suitable providing they are utilized in a sufficiently diluted form to minimize fiber degradation.  
  When the component to be shrunken is a polyacrylic material, the shrinking agent may be an acid such as defined hereinabove as being suitable for nylon; a salt formed from cations selected from the group consisting of Zn, Ag, Ni, Co, Mn, and an anion selected from the group consisting of SCN, l Br, and Cl; disubstituted amides having the formula wherein R is hydrogen or lower alkyl having from 1 to 5 carbon atoms, or lower alkyl carbonates, the alkyl portions of which contain 1 to 5 carbon atoms.  
  Particularly suitable shrinking agents for polyacrylics include alpha-chloroacetic acid, trifluoroacetic acid, hydrochloric acid, nitric acid, sulfuric acid, zinc iodide, silver iodide, ethylene carbonate, propylene carbonate and dimethyl acetamide.  
  When the component to be shrunken is a cellulosic derived material, the the shrinking agent should be a basic material. Suitable shrinking agents for cellulo&#39;sics include inorganic bases such as sodium hydroxide, potassium hydroxide, barium hydroxide, ammonia, strong organic bases having a dissociation constant greater than about 2 X 10*, such as benzyltrimethylammonium hydroxide and tetraethylammonium hydroxide, and organic amines such as, ethylamine, triethyl amine, diisopropryl amine, dibutyl amine, ethylene diamine, triethylene tetramine, and the like.  
  When the shrinking agent is applied in the form of a paste the concentration and viscosity of the shrinking agent will vary depending on the amount of shrinkage and effects desired. Although generally the shrinking agent is in an aqueous solution or mixture, it is possible depending on the laminate used and the shrinking agent to use other solvents.  
  The viscosity of the mixture or paste is usually varied by adding a thickening agent in a manner well known in the art. The preparation of such pastes are well known to the art and, of course, the rheology of the paste will depend on the thickening agent used.  
  After the application of the shrinking agent to the component, the laminate is dried. The conditions of drying will depend not only on the reactivity and the concentration of the shrinking agent, but also on the nature of the heating mechanism and the type laminate being shrunk. Thus for example, when conventional laboratory ovens are used to affect shrinkage of cellulosics, the sodium hydroxide shrinking agent concentration is preferably in the range from about 30 percent to 50 percent and the heating is preferably carried out at a temperature in the range from about 80 to 125C. When high pressure steam-heated, can dryers of the conventional type normally found in textile mills are used, the preferred concentration range for sodium hydroxide when treating a cellulosic material is from about to 25 percent.  
  When a volatile shrinking agent is used, it is generally preferable to heat the material with the shrinking agent thereon in an autoclave. Of course, if a more reactive shrinking agent is used, the drying may be carried out at a lower temperature. Thus, for example, with very reactive shrinking agents, it is possible to dry at room temperature.  
  Consequently, the drying operation can be carried out in a temperature range from about ambient to a temperature limited only by the degradation temperature of the components of the laminate. Usually, the preferable operating temperature would be in the range from about 80to 160C.  
  After the drying step, the fabric is washed to remove any remaining or residual shrinking agent. The components and pH of the backwash, will, of course, depend on the nature of the shrinking agent. Usually it is most desirable for economic reasons that the back washing solution be aqueous.  
  When the shrinking agent is an acid having a dissociation constant greater than about 2 X 10*, an aqueous wash solution containing a relatively weak base such as, for example, sodium carbonate, trisodium phosphate, or ammonia can be used. When the shrinking agent is a weak acid such as phenol, a more alkaline washing solution may be required.  
  If the shrinking agent is an alkaline material having a dissociation constant greater than about 2 X 10*, an aqueous solution containing any inorganic acid with a dissociation constant greater than about 1 X 10&#39; can be used. It is understood, of course, that the washing solution must not contain any materials which will either degrade the materials comprising the laminate or attack the adhesive interlayer.  
  It is also possible, when the shrinking agent is an organic solvent, to remove any residual shrinking agent by steaming or volatilization as by passing the laminate through ovens or over hot cans.  
  As noted hereinabove, the backing component may possess raised fibers in the form of a nap or loops. Usually, such raised fibers are most conveniently obtained by napping the backing fabric.  
  We have further discovered that when a fabric having a backing possessing raised fibers or nap as described hereinabove is used, and both the facing and the backing components are shrunken by either chemical or physical means, a highly unusual rippled effect is produced in the facing component. As noted, the shrinkage treatment in this case may be carried out either by the application of chemical shrinking agents or by physical shrinking means such as for example, heat. Typical of such physical shrinkage treatments is the application of steam, or dyeing in a hot dye bath.  
  If, however, the backing does not possess such raised fibers, an overall densification effect is produced in the facing component simulating a suede fabric.  
  Similarly, other unusual effects may be obtained by using a fabric having a backing possessing raised fibers and either shrinking only the backing component or the facing component.  
  A particularly desirable effect is obtained when a fabric having a backing component possessing raised fibers is subjected to a shrinkage treatment wherein the shrinking agent is applied only to the backing component in a pre-selected design pattern. That is to say, the entire backing component is not subjected to shrinkage, but only portions thereof are shrunken. Such treatment produces contrasting rippled and unrippled areas on the facing component.  
  In addition to the difference in sculptured effect obtained on the facing of the fabric by virtue of the foregoing processes, multi&#39;shade effects are also obtained as a result of the variation in densification of the raised fibers of the facing component.  
  The following examples illustrate our invention: (In the Examples, the adhesive used was an aqueous based acrylic binder unless otherwise noted).  
 EXAMPLE 1 A fabric comprising a woven rayon backing substrate and a 1% mm. rayon flock, with the flock anchored to the backing substrate by an adhesive was completely immersed in a 20 percent solution of sodium hydroxide for 1 minute at room temperature. Without removing the excess liquid by padding, the fabric then was washed in water (50C), rinsed in a 10 percent acetic acid solution and rinsed in water again. The fabric waspadded to remove the excess water and was then dried at C.  
  The modified fabric exhibited a natural skin-like appearance with the flock pointing into various directions thereby creating a random pattern on the flocked surface and a multi-tone effect. The multi-tone effect was enhanced by dyeing the fabric according to methods well known in the art with any type of dye or color desired.  
 EXAMPLE 2 A cotton fabric flocked with a 2 mm. rayon flock was completely immersed in a mixture of liquid ammonia and methylene chloride (50:50) for 1 minute. The excess liquid was removed from the fabric by padding. The fabric was air-dried.  
  The treated substrate resembled a seal-skin. The pile pointed into one direction and exhibited a natural sheen.  
 EXAMPLE 3 A rayon substrate flocked with a /2 mm. rayon flock was completely immersed in a 10 percent solution of sodium hydroxide for 1 minute at room temperature. Without prior padding, the fabric was washed in warm water (50C.), rinsed in an 8 percent acetic acid solution and rinsed in water again. The fabric was padded to remove excess water and was then dried at 100C.  
  A substrate with a natural suede-like character resulted.  
 EXAMPLE 4 A fabric comprising a woven rayon backing substrate and a 1 mm. nylon flock with the flock being anchored to the backing substrate by an adhesive was immersed in a 75 percent acrylic acid/water solution for 3 minutes at room temperature. The treated substrate was rinsed with water until the pH of the rinsing water was approximately 7. Excess water was removed by padding. The fabric was dried at 90C.  
  The modified substrate exhibited a refined velvet-like look.  
 EXAMPLE 5 A fabric comprising a non-woven acrylic backing material and a mm. rayon flock with the flock being anchored to the backing material by an adhesive was knife-coated on the flocked side with a paste composed of 20 percent sodium hydroxide, 5 percent carboxymethyl starch, and 75 percent water. The coated fabric was dried at 100C. for 4 minutes. The fabric was washed in warm water (50C.), rinsed in a percent acetic acid solution, and rinsed again in water. Excess water was removed by padding. The fabric was dried at 100C.  
 The treatment produced a suede-like substrate.  
 EXAMPLE 6 A heavily napped non-woven rayon substrate comprising napped fibers of approximately 1% cm. in length was coated with an aqueous based acrylic flock binder on the napped side by means of a coating knife. The coated substrate was flocked with a rayon flock, 2 mm. in length. The fabric was cured for minutes at 145C.  
  The flocked fabric then was coated on the back side with a paste composed of 40 percent sodium hydroxide, 3 percent carboxymethylated starch and 57 percent water. The paste was allowed to penetrate into the backing substrate for 5 minutes. The fabric then was dried at 140C. for 10 minutes. The fabric was washed in water of approximately 65C., rinsed in a 10 percent acetic acid solution, rinsed again in water followed by squeezing and drying of the fabric. The fabric was dyed with a sulfur dye (C.l. No. 53571) according to conventional methods.  
  The fabric exhibited a two-tone effect and a heavily rippled and crimpled flock surface with an appearance similar to Persian lamb wool or an astrochan fur.  
 EXAMPLE 7 A cotton flannel with a medium degree of napping was coated on the napped side with an aqueous based acrylic flock binder. The coated fabric was flocked with rayon flock 1 mm in length and was then cured for 10 minutes at 140C. A checkerboard pattern was printed onto the backing substrate with a paste composed of percent sodium hydroxide, 3 percent carboxymethylated starch and 77 percent water. The printed fabric was dried for 4 minutes at 140C, washed in water of 70C, rinsed in a 10 percent acetic acid solution, rinsed again in water and was then squeezed and dried. The fabric was dyed with a sulfur dye (l. C. No. -5357l) according to conventional methods.  
  The resulting fabric exhibited a quilt-like effect, in that the areas which did not come in contact with the shrinking agent puckered producing an overall threedimensional effect. In addition, the areas which were shrunk by the paste exhibited a rippled and two-toned effect.  
 EXAMPLE 8 A cotton flannel was napped in preselected areas to produce a design comprising napped and un-napped areas. The fabric was then coated overall with an aqueous based acrylic flock binder on the side which was napped in preselected areas. The coated fabric was flocked with a rayon flock 1 mm in length and cured for 15 minutes at 140C.  
  The flocked fabric was coated overall on the backside with a paste comprising 20 percent sodium hydroxide, 3 percent carboxy-methylated starch and 77 percent water. The backcoated fabric was dried for 3 minutes at 140C, washed in water having a temperature of 80C, rinsed in a 10 percent acetic acid solution and rinsed again in water. The water was removed by squeezing and the fabric was dried and dyed with a sulfur dye (C. I. No. -53571 according to standard procedures.  
  A flocked fabric resulted with areas exhibiting a three-dimensional rippled and two-toned effect and with areas exhibiting a smooth, two dimensional flock surface and a one-toned effect.  
 EXAMPLE 9 A woven and heavily napped polyester substrate was coated with an aqueous based acrylic flock binder on the napped side. The coated substrate was flocked with rayon flock 2 mm. in length. The fabric was cured for 15 minutes at C.  
  The fabric was exposed to a temperature of C. for 7 minutes. After cooling to room temperature, the fabric was dyed at 85C. for 20 minutes in a dye bath containing a dispersed dye (Disperse Red 131) and a direct dye (C. 1. No. 22120). The fabric was washed in hot water (70C), squeezed, and dried.  
  The fabric exhibited a two-tone effect and a rippled flock surface resembling Persian lambs wool.  
  Variations can, of course, be made without departing from the spirit and scope of the invention.  
  Having thus described our invention what we desire to secure and claim by Letters Patent is:  
  1. A process for making a decorative flocked fabric comprising:  
 a. coating a substrate with a flock adhesive binder wherein said substrate is a napped fabric composed of textile materials selected from the group consisting of nylon, cellulosic materials and polyacrylic materials, wherein the binder is applied to the napped side;  
 b. applying a flock selected from the group consisting of nylon, cellulosic materials, and polyacrylic materials to the coated substrate and permanently securing the flock to the substrate by curing the binder;  
 c. applying a chemical shrinkage agent directly onto the flock;  
 d. drying the fabric; and  
 e. washing the fabric.  
  2. The process of claim 1 wherein the chemical shrinkage agent is applied to selected portions of the flock.  
  3. The process of claim 1 wherein the flock is nylon and the shrinking agent is an acid having a dissociation constant greater than about 2 X 10 and is selected.  
 from the group consisting of strong mono and polybasic inorganic acids; organic acids having the formula R-&#39; COOH wherein R is hydrogen, lower alkyl having 1 to 5 carbon atoms, halogen substituted lower alkyl having 1 to 5 carbon atoms or a nucleus of the phenyl series; sulfonic acids; and phenols.  
  4. The process of claim 1 wherein the flock is a cellulosic material and the shrinking agent is a base selected from the group consisting of alkali hydroxides, alkaline earth hydroxides, ammonia, and organic bases having a dissociation constant greater than about 2 X 5. The process of claim 1 wherein the flock is polyacrylic and the shrinking agent is an acid having a dissocation constant greater than about 2 X 10&#39; and is selected from the group consisting of strong mono and polybasic inorganic acids; organic acids having the formula R-COOl-l wherein R is hydrogen, lower alkyl having 1 to 5 carbon atoms, halogen substituted lower alkyl having 1 to 5 carbon atoms; or a nucleus of the phenyl series; sulfonic acids, phenols; a salt formed from cations selected from the group consisting of Zn, Ag&#34;, Ni, Co, Mn and an anion selected from the group consisting of SCN, l, Br, and Cl; a  
 disubstituted amide having the formula the process of claim 1.