US3719547A

US3719547A - Flame retardant pile fabric

Info

Publication number: US3719547A
Authority: US
Inventors: D Durant; R Bryan; D Martin; D Holmer; J Saunders; W Black
Original assignee: Monsanto Co
Current assignee: Monsanto Co
Priority date: 1970-12-09
Filing date: 1970-12-09
Publication date: 1973-03-06
Anticipated expiration: 1990-03-06

Abstract

A FLAME RETARDANT PILE FABRIC IS PROVIDED. A FIBROUS LAYER COMPOSED OF COMBUSTIBLE FILAMENTS OR FIBERS EXTENDS FROM THE TOP SURFACE OF A FIBROUS BACKING TO PRESENT A PILE SURFACE. A COATING OF A FILM FORMING HALOGEN-CONTAINING POLYMER AND A WATER-INSOLUBLE ORGANO-PHOPHOROUS COMPOUND IS PPLIED TO AND CONFINED ESSENTIALLY TO THE TOP SURFACE

OF THE BACKING. WHERE THE BACKING IS MADE IN THE MAIN OF A THERMOPLASTIC MATERIAL, A COATING OF THE HALOGEN-CONTAINING POLYMER WITHOUT THE ORGANO-PHOSPHOROUS COMPOUND RENDERS THE FABRIC SUFFICIENTLY FLAME RETARDANT.

Description

'March 6, 1973 D. H. MARTIN ,1 9,

FLAME RETARDANT PILE FABRIC Filed D60. 9, 1970 INVENTORS DONALD H. MARTIN DONALD A. HOLMER DENNIS J. DURANT ROLAND J. BRYAN, JR.

JAMES H. SAUNDERS WILLIAM B. BLACK BY ,dm p 2. 7m

ATTORNEY United States Patent O 3,719,547 FLAME RETARDANT PILE FABRIC Donald H. Martin, Gulf Breeze, and Donald A. Holmer, Dennis J. Durant, Roland J. Bryan, Jr., James H. Saunders, and William B. Black, Pensacola, Fla., assignors to Monsanto Company, St. Louis, Mo.

Filed Dec. 9, 1970, Ser. No. 96,403 Int. Cl. D03d 27/00; D04h 11/00 US. Cl. 161-67 5 Claims ABSTRACT OF THE DISCLOSURE A flame retardant pile fabric is provided. A fibrous layer composed of combustible filaments or fibers extends from the top surface of a fibrous backing to present a pile surface. A coating of a film forming halogen-containing polymer and a water-insoluble organo-phosphorous compound is applied to and confined essentially to the top surface of the backing. Where the backing is made in the main of a thermoplastic material, a coating of the halogen-containing polymer without the organo-phosphorous compound renders the fabric sufliciently flame retardant.

BACKGROUND OF THE INVENTION The reduction of the flammability of pile fabrics prepared from cellulosic and synthetic filaments and fibers has long been the subject of much research effort. Continuing search is made for ways to render such fabrics less flammable. Many improvements toward this end have been made. However, two recent innovations in pile fabric have increased the flammability thereof such that prior procedures for reducing the flammability are no longer entirely suitable. In one instance there is a recent increased consumer demand for carpets of shag construction. The

long, coarse nap on the surface of a shag carpet provides an environment for flame propagation. Also, to render carpets having a pile of synthetic fibers antistatic and soil resistant, it is common practice in most recent times to incorporate relatively large amounts of polyalkoxylated compounds. These additives are wax-like and per se are flammable. A fire hazard exists where a shag carpet is made of pile fibers having polyalkoxylated compounds to reduce the static build-up and soiling.

Surprisingly, the present invention provides a flame-retardant carpet even in most shag constructions wherein the pile filaments or fibers have anti-static quantities of polyalkoxylated compounds incorporated therein.

SUMMARY OF THE INVENTION The flame-retardant pile fabric structure described herein is composed of a fibrous layer composed of normally combustible filaments or fibers made from synthetic polymers or cellulose based materials including cotton, rayon, cellulose acetate and the like. This layer may be a yarn pile preferably made of a synthetic polymer including polyester, polyamide, modacrylic and polyolefins. Most preferably, the pile yarn is made of polyamide (particularly nylon-66 or nylon-6) and contains an antistatic quantity of a combustible wax-like substance. The pile yarn is secured in a primary backing by tufting, flocking, weaving, or the like. On the pile side of the backing there is applied a thin coating composed of an intimate mixture of a filmforming halogen-containing polymer and a Water-insoluble organo-phosphorous compound. The phosphorous compound is a plasticizer of polyvinyl chloride and of polyvinylidene chloride. The coating is essentially confined to the top surface of the backing. Optionally, the pile fabric structure has a secondary backing of conventional construction. For backing made of thermoplastic material an 3,719,547 Patented Mar. 6, 1973 "ice application of a halogen-containing polymer alone will suffice. The structure has a high degree of resistance to ignition and burning and has a low level of flammability or flame spread. A method of making the pile fabric structure is provided.

DESCRIPTION OF THE DRAWING DETAILED DESCRIPTION OF THE INVENTION The primary carpet backing is made from suitable material. It is be a conventional woven jute construction. Also, the backing may be made of a non-woven fibrous mass made of cellulosic or non-cellulosic material including nylon, polyester, and polyolefin. Backing constructed from twistless flat ribbons of synthetic filaments or ribbon-like materials can be used. Other fabric backing structures likewise can be used.

The film-forming polymer ingredient of the topside applied emulsion, plastisol, solution, or latex is composed in the main of a halogen-containing polymer which includes polymeric vinyl halide, polymeric vinylidene halide or c0- polymers thereof. An additional and particularly convenient form in which to apply plastisols is a foamed product. By film forming is meant the ability to form films by air drying a deposited coating or by coalescing or agglomerating the polymer latex with subsequent fusion. Minor amounts of other monoethylenically unsaturated compounds such as vinyl acetate, acrylonitrile, and the like may be copolymerized with vinyl halide and/ or vinylidene halide to provide a suitable film-forming polymer. The amount of the non-halide comonomer is variable depending on the particular monomers employed and on the fabric structure However, increasing the amount of nonhalide comonomer results in reducing the flame retardant properties. Therefore, selection is made with regard to flame retarding properties of the polymer produced and the fabric structure desired. Especially useful are polymeric vinyl chloride, polymeric vinylidene chloride, and copolymers thereof. A very useful range of copolymers are those containing from 10 to 20 percent of vinyl chloride copolymerized with 90 to percent vinylidene chloride. Chlorine-containing polymers derived from dienes, e.g. polychloroprene, chlorinated rubber and rubber hydrochloride are suitable but to a lesser degree. In place of the chlorine compounds described, there may be used the corresponding bromine or iodine compounds, as well as co polymers thereof, provided they are film-forming.

The polyvinyl chloride plasticizers incorporated into the film-forming material applied to the topside of the primary backing may be any suitable organo-phosphorous compound. Preferred are phosphate esters of three general classes: trialkyl phosphates, triaryl phosphates, and mixed alkyl aryl pohsphates. These orthophosphate esters conform to the formula wherein R R and R are the same or different monovalent radicals selected from the group consisting of an aliphatic radical of 1-24 carbon atoms, an alicyclic radical and an aromatic radical. R R and R may or may not be halogenated. Preferably R is a branched chain alkyl radical terminating with a CH group and containing at least 6 and not more than 15 carbon atoms and R and R are phenyl radicals. Among the triaryl esters are tricresyl phosphate, triphenyl phosphate, diphenyl cresyl phosphate, diphenyl xylyl phosphate, tritolyl phosphate. Among the trialkyl phosphate esters are tri(n-octyl)phosphate, tri(2-ethylhexyl)phosphate, triethyl phosphate, tributyl phosphate, tri(dichloropropyl)phosphate, trichloroethyl phosphate, tributoxyethyl phosphate. The preferred orthophosphate esters are triaryl phosphates and alkyl diaryl phosphate, the latter class of phosphates being preferred. Among the dialkyl monoaryl phosphates are di- (2-ethylhexyl)phenyl phosphate, di(n-butyl)cresyl phosphate, etc. Among the alkyl diaryl phosphates are methyl diphenyl phosphate, ethyl diphenyl phosphate, propyl diphenyl phosphate, n-butyl diphenyl phosphate, Z-methylpropyl diphenyl phosphate, 2,2-di-methylpropyl diphenyl phosphate, n-hexyl diphenyl phosphate, n-heptyl diphenyl phosphate, n-octyl diphenyl phosphate, 6-methylheptyl diphenyl phosphate, Z-ethylhexyl diphenyl phosphate, 3,5,5- trimethylhexyl diphenyl phosphate, ethyl ditolyl phosphate, n-hexyl ditolyl phosphate, 2-methylpentyl ditolyl phosphate, 2-ethylbutyl ditolyl phosphate, n-octyl ditolyl phosphate, 2-ethylhexyl ditolyl phosphate, 3,5,5-trimethylhexyl ditolyl phosphate, n-decyl ditolyl phosphate, 2-ethy1hexyl phenyl cresyl phosphate, lauryl phenyl cresyl phosphate, 2-butylhexyl ditolyl phosphate, n-dodecyl ditolyl phosphate and 2-butyloctyl ditolyl phosphate. The preferred of the above-mentioned compounds is 2-ethylhexyl diphenyl phosphate.

The selected film-forming halogen-containing polymer and the organo-phosphorous compound are compounded by conventional methods into a solution, organosol, latex, comprising about 35% to about 70% non-volatiles or plastisol. For example, an emulsion of the plasticizer in water is prepared and subsequently stirred into the latex by high speed agitation. A suitable emulsifying agent may be employed to promote emulsification of the two immiscible phases. Although the proportion of plasticizer to be used will vary somewhat with the effectiveness thereof, preferably, the organo-phosphorous compounds constitute about 15% to about 60% b weight of the two nonvolatile materials. When a solution of film-forming halide polymer is employed, the amount of polymer will normally constitute about 15-35% by weight thereof.

The coating material (latex, plastisol, organosol, or solution) is applied to the topside of the carpet backing. Care is taken that the coating material is uniformly spread by conventional techniques in the form of a thin film in sufficient amount that on a dry basis or more accurately on a non-volatile content basis the add-on weight is about 1.5 to 10 ounces per square yard of backing. After the backing has been properly coated, it is cured by known procedures, preferably in an oven by the application of heat. The coating material should be viscous to give a proper coating on the backing without penetrating the backing to an undesirable extent. Thickening agents may be added if needed. If desired, the coating of the filmforming, halogen-containing polymer may also be applied by suitable techniques, e.g. by spreading an organosol coating, by heat sealing or glueing a suitable plasticized film onto the backing, by solution application, spreading a foamed or unfoamed plastisol, and the like.

The pile is woven in, tufted through, flocked, knitted or in some other manner embedded in the cured backing material. Yarn loops on the top face of the backing may or may not be cut in whole or in part as desired. The loops may have the same height or have various heights in the pile.

The fibrous pile can be composed of any of the usual synthetic filaments or fibers or blends or mixtures thereof employed in carpet manufacture including: 1) Polyamides, also called nylon which is a. manufactured fiber of any long chain synthetic polycarbonamide having recurring amide groups as an integral part of the polymer chain; specific examples include polymeric hexamethylene adipamide (nylon-66), polymeric 6-amino caproic acid (nylon-6), polymers of 1,4-cyclohexanedimethylamine and adipic acid (CBMA-6) or dodecanedioic acid (CBMA-l2), polymers of bis(para-aminocyclohexylmethane) and azelaic acid (PACM-9) or dodecanedioic acid (PACM-l2). (2) Polyesters, made of a fiber-forming substance of any long chain synthetic polymer composed of at least by weight of an ester of a dihydric alcohol and terephthalic acid, specific dihydric alcohols including ethylene glycol, 1,4-butanediol and 1,4-cyclohexanedimethanol. (3) Modacrylics made of a fiber-forming substance composed of less than 85% but at least 35% by weight of acrylonitrile units. (4) Polyolefins made of a fiber-forming substance composed of at least 85% ethylene, propylene or other olefin units.

Materials, such as polyalkoxylated compounds, may be incorporated in the filaments or fibers to lower the propensity of buildup of static electricity thereon. The compounds will normally be finely dispersed as a separate phase in the polymer in an amount of l-15 based on the weight of the filaments or fibers. A preferred additive is a polyalkoxylated triglyceride of a saturated hydroxy fatty acid having 12-30 carbon atoms as disclosed in US. Pat. 3,388,104. The polyoxyalkylene portion of the glyceride should be in the molecular Weight range of 1000 to 30,000 and may be ethoxy, propoxy, etc. Alternatively, po1y(alky1ene ethers) may be incorporated in the pile fibrous material. These additives are ethylene oxide, propylene oxide, etc. condensation products. Also, polyalkoxylated saturated di-fatty alkyl amines wherein the polyalkoxy portion has a molecular weight of about 2000 to 22,000 and wherein the two fatty alkyl substituents have 10 to 30 carbon atoms are useful. Combination of additives are contemplated. The presence of such additives in nylon-66 yarn in antistatic quantities normally renders the yarn non-self-extinguishing to a flame, Whereas otherwise the yarn would be self-extinguishing to an applied flame.

The following examples illustrate the invention.

EXAMPLE I (a) Nylon-66 yarn containing 7.5% dispersed polyethoxylated glyceryl tri(hydroxystearate) (200 mols of ethylene oxide per mole of glyceryl trihydroxy stearate) as disclosed in US. Pat. 3,388,104 and composed of 136 filaments with a flat drawn denier of 2460 was textured by gear crimping as disclosed in US. Pat. 3,024,517. Three separate ends of this yarn were loosely plied together. The resulting ply yarn was tufted into a 10 ounce (Weight per square yard) plain weave jute carpet backing. The pile height of the yarn was 1% inch. The number of tufts per square inch averaged 7.8. A hexamethylenetetramine pellet weighing 0.15 gram was placed in the center of a 4-inch square sample of the carpet structure and was ignited. The flame ignited the pile fabric and was propagated along the pile of tufted fabric. Hence, the carpet was not flame retardant.

(b) A polyvinyl chloride latex composed of an aqueous emulsion of polyvinyl chloride and 2-ethylhexyldiphenyl phosphate was prepared. For parts by dry weight of polyvinyl chloride there were 85 parts by dry weight 2-ethylhexyldiphenyl phosphate. Together these two ingredients gave the emulsion a 58.7% non-volatile content. The latex was evenly spread along the top side of a 10 ounce plain weave jute carpet backing. The addon Weight of polyvinyl chloride and 2-ethylhexyldiphenyl phosphate on a dry basis was 3.9 ounces per square yard. This coated backing was cured in a hot air oven at C. for 25 minutes. The plied nylon-66 yarn as described above in this example was tufted into the cured backing. In like manner, the pile height of the yarn Was 1% inches and the number of tufts per square inch averaged 7.8. A hexamethylenetetramine pellet weighing 0.15 gram was placed in the center of a 4-inch square sample of the carpet structure and was ignited. After the pellet had burned, essentially no additional burning of pile fabric occurred. The charred area was confined to a small area, about inch in diameter adjacent the position of the pellet. Hence, the carpet was regarded as flame retardant.

EXAMPLE II (a) The unbacked carpet of Example I(a) was blankdyed, i.e. subjected to normal carpet dyeing conditions without the presence of a dyestuff. The blank-dyeing procedure consisted of boiling for one hour in an aqueous bath containing (on fiber weight) 2% trisodium phosphate, 2% ammonium sulfate, 1%% of surface active agent with total liquid:fiber ratio of 40:1 by Weight. The sample was then rinsed in cold water, dried in a hot air oven for 2 hours at 105 C., and desiccated over silica gel for 1 hour. The carpet was then tested using the hexamethylenetetramine pellet as described in Example 1(a). The flame ignited the fabric and propagated. Hence, the carpet was not flame-retardant.

(b) The unbacked carpet of Example I(b), where the add-on was 3.9 oz./ sq. yd. of polyvinyl chloride and 2- ethylhexyldiphenyl phosphate, after tufting was blankdyed, rinsed, dried and desiccated as in Example II(a). The carpet was then tested using the hexamethylenetetramine pellet as described in Example 1(a). The flame did not propagate along the tufts; and, the carpet was regarded as flame-retardant. Therefore, the improvement of the present invention persists even after the carpet is subjected to normal dyeing conditions.

(c) The carpet was the same as that in Example II(b) above, except that the add-on was 5.1 oz./sq. yd. of polyvinyl chloride and 2 ethylhexyldiphenylphosphate. The carpet was treated the same as that in Example II(b) above. This carpet was tested in a similar fashion including blank-dyeing and was found to be flame-retardant.

EXAMPLE III (a) Example II(a) was repeated except that instead of the jute backing a non-woven polypropylene backing reinforced with a warp of spun polyethylene terephthalate threads was employed. The backing weighed 6.5 ounces per square yard and was commercially available under the name Loktuft from Phillips Fibers. It was found that the resulting carpet structure was not flame-retardant when subjected to the pellet test.

(b) Example II(a) was repeated except that the nonwoven polypropylene backing (Loktuft) was used and the add-on weight of the polyvinyl chloride and Z-ethylhexyldiphenyl phosphate was 3.8 ounces per square yard. Again it was found that using the pellet test the resulting carpet structure was flame-retardant.

(c) When the amount of the 100/85 mixture of polyvinyl chloride and Z-ethylhexyldiphenyl phosphate was reduced below 2 ounces per square yard, the carpet of Example II(a) was found not to be flame-retardant. Specifically, Example III(b) was repeated except that the add-on of halide polymer-phosphate mixture was reduced to 1.1 ounces per square yard. At this level the carpet failed the pellet test.

EXAMPLE IV (a) A solution of grams of polyvinyl chloride copolymer containing a very minor amount of a monomer other than vinyl chloride (analysis: 47.2% Cl) and 10 grams of an organo-phosphate compound of the formula where six Xs are chlorine and four Xs are bromine was prepared. Eighty grams of chlorobenzene was used as the solvent. Nylon-66 yarn of the type described in Example I(a) was tufted into a 10 ounce plain weave jute carpet backing. Prior to tufting the polyvinyl chloride-organo-phosphate solution was added to one side of the jute fabric which then was dried to provide an add-on weight of polyvinyl chloride-organo-phosphate of 2.0 ounces per square yard on a dry basis. The pile height of the yarn was 1% inches and the number of tufts per square inch was 7.8. A hexamethylenetetramine tablet weighing 0.15 gram was placed in the center of a 7 inch square sample of the carpet structure and was ignited. The flame was not propagated and the charred area was restricted to a small area. adjacent the location of the tablet. Hence, the carpet was flame-retardant.

(b) Example IV(a) Was repeated except that the organo-phosphate compound was slightly different from a chemical structure standpoint. In this instance the phosphate compound had the following structure (M) 011201 (I? (ClCH CHzOMP OCHz--(. .O P(OCH2CH2Cl)1 When the resulting structure was subjected to the pellet test, it was again found that the flame was not propagated and the charred area was restricted to a small area adjacent the location of the pellet.

EXAMPLE V An emulsion of 65.0 grams of tris(2,3-dibromopropyl) phosphate, 1.25 grams of oleic acid, 0.35 gram NH OH (28% by weight), and 33.4 grams water was prepared with a high shear mixing device. This emulsion was added to and mixed with 252 grams of an aqueous emulsion of a polyvinyl chloride and Z-ethylhexyl diphenyl phosphate (35 weight parts of phosphate compound to weight parts of vinyl chloride polymer). A piece of 9-inch square of Loktuft carpet backing Weighing 7.3 grams was treated on the upper face side with the resulting mixture of emulsions and cured 40 minutes at 106 C. in a forced air oven to give an add-on weight of 5.3 ounces per square yard. This treated backing was tufted with the type of yarn described in Example I(a) except in this instance the yarn was a single end of 3690 total denier and the pile weight was 23.5 ounces per square yard. This carpet fabric was latexed on the underside with 26 ounces per square yard of a compounded carboxylated styrene butadiene rubber latex. The rubber latex is sold by Textile Rubber Co., under the name L-1254 latex. A secondary backing of Loktuft as applied and the resulting carpet composite was cured for 40 minutes at 106 C. As above, a small hexamethylenetetramine tablet was placed in the center of the carpet sample and was ignited. The flame was not propagated; thus, the carpet was flameretardant.

EXAMPLE VI (a) This example shows that vinylchloride polymer without an organo-phosphate compound when applied to a jute fabric will not sufficiently flame retard a nylon pile. A PVC latex consisting of 38.6% vinylchloride polymer (97% vinylchloride and 3% vinyl acetate) was applied evenly to the top surface of jute carpet backing fabric as in Example I(b) and cured at C. for 20 minutes. The add-on weight of vinyl chloride polymer on a dry basis was 5.0 ounces per square yard Nylon 66 yarn of the type described in Example I(a) was tufted into the treated jute fabric at 2.8 rows per inch and 2.8 stitches per inch, with a pile height of 1% in. A hexamethylenetetramine tablet weighing 0.15 gram was placed in the center of a 7 in. square sample of the carpet structure and was ignited. The flame was propagated along the surface of the carpet sample for a period of 9 minutes, covering a large area of the sample before it was extinguished. Hence, the carpet was not flame-retardant.

(b) A PVC latex consisting of 38.6% vinyl chloride polymer (97% vinyl chloride and 3% vinyl acetate) was applied evenly to the top surface of jute carpet backing fabric as in Example 1(b) and cured at 150 C. for 20 minutes. The add-on weight of vinyl chloride on a dry basis was increased to 11.3 ounces per square yard. Nylon 66 yarn of the type described in Example 1(a) was tufted into the treated jute at 2.8 rows per inch and 2.8 stitches per inch, with a pile height of 1 A in. A hexamethylenetetramine tablet weighing 0.15 gram was placed in the center of a 7 inch square sample of the carpet structure and was ignited. The flame was propagated along the surface of the sample for a period of 9 minutes; the burn covered a large area of the sample before it was extinguished. Hence, the carpet was not flame-retardant even though a rather large amount of vinyl chloride polymer was coated on the top side of the jute fabric.

EXAMPLE VII A piece of Loktuft carpet backing was tufted with yarn as in Example I(a) (except this yarn was a single end of 3690 total denier) at a weight of 23.5 ounces per square yard. The carpet fabric was latexed on the underside with 26 ounces per square yard of L-1254 latex (Textile Rubber Company) above-described, and a secondary backing of Loktuft was applied; the carpet sample was cured 40 minutes at 106 C. A hexamethylenetetramine tablet was placed in the center of the sample and ignited. The flame was propagated along the surface of the sample for a period of 10 /2 minutes; the burn covered a large area of the sample before it was extinguished. Hence, carpet constructed of nylon-66 pile and a nonwoven thermoplastic backing without the coating of halogencontaining polymer plus organo-phosphorous compound is not flame-retardant.

EXAMPLE VIII An aqueous emulsion latex of 35 parts of dioctyl phthalate per 100 parts of film-forming polyvinyl chloride was prepared, the percent solids in the latex being 57. Dioctyl phthalate is a conventional plasticizer for vinyl chloride polymer but contains no phosphorous. The latex was evenly spread along the top side of a 10 ounce plain weave jute carpet backing. The add-on weight of the latex solids was 4 ounces per square yard. The coated backing was cured in a hot air oven at 105 C. for 25 minutes and then cooled. The plied nylon 66 yarn as described in Example 1(a) was tufted to provide a shag construction. The carpet sample was tested for flame-retardancy using the above-described pellet ignition test. It was noted that the flame propagated along the tufts of the carpet. This shows that nylon pile shag yarn in a jute backing, the top side of which is coated with a vinyl chloride polymer but no organo-phosphate plasticizer is not flameretardant.

EXAMPLE IX (a) A 10 ounces per square yard jute fabric was tufted to the following specifications: 2.8 rows/in., 4.2 stitches/ in., 1 /2 in. pile height, 26 ounces per square yard of heat-set, 1% turn per inch (t.p.i.) twist, 3690 total denier nylon 66 yarn of three types. The three types were (1) a nylon-66 yarn containing 7 /z% dispersed polyethoxylated glyceryl tri(hydroxy stearate) as described in EX- ample I(a); (2) a nylon-66 yarn as in (1), but containing in addition a small amount of disodium-disulfobenzoic acid for cationic dyeability; and (3) a yarn of 94% nylon-66 and 6% nylon-6 copolymer containing /2% of the just-mentioned stearate. The tufted fabric was blankdyed in a standard apparatus. The fabric was first washed in a bath containing 2% sodium hydrosulfite and 1% trisodium phosphate (on fiber weight) with 40:1 liquor: fiber ratio for 15 minutes at 49 C. The fabric was rinsed and then blank-dyed for one hour at 100 C. in a bath containing 1% surfactant (on fiber weight) with monosodium phosphate added to bring pH to 6.0. The fabric was rinsed and dried in a hot air tumble dryer. It was hand-latexed with 26 ounces per square yard L-1254 latex (Textile Rubber Company) and cursed at 130 C. for 25 minutes. No secondary backing was applied.

Eight 81 square inch (9 in. x 9 in.) samples were tested according to ASTM-2859-70T; 8 of 8 failed the test, hence the carpet was not flame-retarded.

EXAMPLE X A 10 ounces per square yard jute fabric carpet backing was treated on the top side with 5.1 ounces per square yard on a dry basis of the polyvinyl chloride and 2- ethylhexyldiphenyl phosphate latex. For 100 parts by weight of polyvinyl chloride, there was 85 parts by dry weight 2-ethylhexy1diphenyl phosphate; together these two ingredients gave the emulsion a 58.7% non-volatile content. This coated jute backing was tufted as described in Example IX(a) above and then blank-dyed and dried as above; it was then hand-latexed with 26 ounces per square yard of L-1254 latex as in Example IX(a). No secondary backing was applied. Eight 81 square inch (9 in. x 9 in.) samples were tested according to ASTM- 2859-70T; 7 out of 8 passed; thus the carpet was flameretardant according to this carpet flammability test.

EXAMPLE X1 (a) A 5.5 ounces per square yard Loktuft polypropylene carpet tufting fabric was tufted to the following specification: 2.8 rows/in, 4.2 stitches/in, 25 ounces per square yard of heat-set, 1% t.p.i. twist, 3690 total denier nylon 66 yarn of the type described in Example IX(a) with a 1 /2 inch pile height. The tufted fabric was blank-dyed, and dried as described in Example IX(a). It was then hand-latexed on the back side with 26 ounces per square yard L-l254 latex (Textile Rubber Company) and cured at 120l30 C. for 25 minutes. A secondary backing of 5.5 ounces per square yard Loktuft was then applied.

1 ight 81 square inch (9 in. x 9 in.) samples were tested according to ASTM285970T; 2- of 8 failed the test, hence the carpet was not completely flame-retardant and failed to pass this particular test for carpet flammability.

(b) A polyvinyl chloride latex composed of an aqueous emulsion of polyvinyl chloride and Z-ethylhexyldiphenyl phosphate was prepared as in Example I(b); for parts by 'weight of polyvinyl chloride; there was 85 parts by dry weight 2-ethylhexyldiphenylphosphate. The latex was evenly spread on the top side of a 4.5 ounces per square yard Loktuft polypropylene carpet backing fabric. The add-on weight of polyvinyl chloride and Z-ethylhexyldiphenyl phosphate on a dry basis was 3.0 ounces per square yard. This coated Loktuft polypropylene carpet backing was tufted according to the specification given in Example XI(a) above, and this carpet was blank-dyed and dried as in Example IX(a). The carpet fabric was hand-latexed as in Example XI(a) above, and a secondary backing of 5.5 ounces Loktuft was then applied. Eight 81 square inch (9 in. x 9 in.) samples were tested according to ASTM-2859-70T; 8 passed and none failed the test; hence the carpet was sufliciently flame-retarded by the coating on the upper surface of the primary backing to permit the carpet to pass this particular test for carpet, whereas the carpet in Example XI(a) above made with the uncoated primary backing failed.

(c) A 6.5 ounces (weight per square yard) Loktuft polypropylene carpet backing fabric was treated on the top side with 7.1 ounces per square yard on a dry basis of the polyvinyl chloride and 2-ethylhexyldiphenyl phosphate latex described in Example XI(b) above. This coated Loktuft backing was tufted as described in Example XI(a) above and then blank-dyed and dried as in Example X(a). The carpet fabric was hand-latexed as in Example XI(a) above, and a secondary backing was applied as in Example XI(b) above. Eight 81 square inch (9 in. x 9 in.) samples were tested according to ASTM- 9 2859-70T; 8 out of 8 passed, sufliciently flame-retarded by the coating on the upper surface of the primary backing to permit the carpet to pass this particular test for carpet flammability, whereas the carpet made with the uncoated primary Loktuft backing failed.

EXAMPDE XII (a) A 3.4 ounces per square yard nylon 66 filament spunbonded nonwoven fabric made by Monsanto Company and named Cerex was tufted to the following specifications: 2.8 rows/in., 4.2 stitches/in, 1 /2 in. pile height, 26 ounces per square yard of heat-set, 1% t.p.i. twist yarns of the type described in Example IX(a). This carpet was washed as described in Example IX(a), blankdyed as described in Example II(a), and dried.

Eight 81 square inch (9 in. x 9 in.) samples were handlatexed with Textile Rubber Companys L-l254 latex, and secondary-backed with Cerex nonwoven product. Eight samples were then tested according to ASTM-2859- 7OT; of 8 failed. Hence, the carpet was not flameretarded.

(b) A polyvinyl chloride latex composed of an aqueous emulsion of polyvinyl chloride and Z-ethylhexyldiphenyl phosphate was prepared as in Example X. For 100 parts by dry weight of polyvinyl chloride, there was 85 parts by dry weight 2-ethylhexyldiphenyl phosphate. The latex was evenly spread along the top side of a 3.4 ounces per square yard Cerex fabric. The coated backing was cured in a hot air oven. The add-on weight of polyvinyl chloride and Z-ethylhexyldiphenyl phosphate on a dry basis was 3.5 ounces per square yard. This coated backing was tufted to the following specifications: 2.8 rows/in., 4.2 stitches/in., 1 /2 in. pile height, 26 ounces per square yard of heat-set, 1% t.p.i. twist yarns of the type described in Example IX(a). This carpet was stripped, blank-dyed, and dried as in Example XII(a).

Eight 81 square inch (9 in. x 9 in.) samples were handlatexed with Textile Rubber Companys L-l254 latex, and secondary-backed with Cerex fabric. Eight samples were then tested according to ASTM-2859-70T; 8 of 8 passed.

The charred area was confined to a small area, about 1% in. diameter adjacent to the position of the pellet. Hence, the carpet was regarded as flame-retardant.

(c) A polyvinyl chloride latex composed of an aqueous emulsion of polyvinyl chloride and 2-ethylhexyldiphenyl phosphate was prepared. For 100 parts by dry weight of polyvinyl chloride, there was 85 parts by dry weight 2- ethylhexyldiphenyl phosphate. The latex was evenly spread along the top side of a 3.4 ounces per square yard Cerex carpet backing. The coated backing was cured in a hot air oven. The add-on weight of polyvinyl chloride and 2-ethylhexyldiphenyl phosphate on a dry basis was 5 ounces per square yard. This coated backing was tufted to the following specifications: 2.8 rows/in, 4.2 stitches/ in., 1 /2 in. pile height, 26 ounces per square yard of heatset, 1% t.p.i. twist yarn of the type described in Example IX(a). This carpet was stripped, blank-dyed, and dried as in Example XII(a).

EXAMPLE XIH (a) Nylon yarn of the type described in Example I(a) was tufted into a 4 ounces per square yard Loktuft polypropylene carpet backing. The yarn was 4920 total denier and was tufted to a pile height of 1% in. The number of tufts per square inch was 7.8. The 5 in. x 5 in. square tufted area was then latexed on the under side with Textile Rubber Companys L-1254 latex at a level of 26 ounces per square yard; the latex was cured for 20 min. at 120 C. The samples were then tested according to the proposed ASTM-285970T procedure except for size of sample. In two of four samples tested, the flame ignited the pile fabric and was propagated along the pile of tufted fabric. Hence, the carpet was not flame-retardant.

(b) A 4 ounces per square yard Loktuft polypropylene carpet backing was coated on the upper side with 2.2 ounces per square yard of vinyl chloride polymer-containing latex (97% vinyl chloride plus 3% vinyl acetate). The pretreated backing was cured 20 minutes at 120 C. Nylon yarn like that used in Example XIII (a) above was tufted into the pretreated backing so that the tufts and PVC coating were face up. The pile height of the yarn was 1% in.; the number of tufts per square inch was 7.8. The 5 in. x 5 in. square tufted area was then latexed with Textile Rubber Companys L-l254 latex at a level of 26 ounces per square yard. The latex was cured for 20 minutes at 120 C. The samples were then tested according to the proposed ASTM-2859-70T procedure except for the size of the carpet samples. Eight of eight passed with an average burn time of 2 minutes 3 seconds. Thus, the polyvinyl chloride coating on the upper face side of the primary backing greatly increased the flameretardancy of this carpet wherein the backing is a thermoplastic material.

(c) A 4 ounces per square yard Loktuft polypropylene carpet backing was coated on the face side with 4.7 ounces per square yard of a latex consisting of 38.6% vinylchloride polymer (97% vinyl chloride and 3% vinyl acetate). The pretreated backing was cured for 20 minutes at 120 C. Nylon yarn like that used in Example XIII(a) above was tufted into the pretreated backing so that the tufts and PVC coating were face up. The pile height of the yarn was 1% in., the number of tufts per square inch was 7.8. The 5 in. x 5 in. square tufted area was then latexed with Textile Rubber Companys L-1254 latex at a level of 26 ounces per square yard. The latex coated structure was cured for 20 minutes at 120 C. The samples were then tested according to the proposed ASTM-2859- 7OT procedure except for the size of the carpet samples. Eight of eight passed with an average burn time of 2 minutes 11 seconds. Thus, the polyvinyl chloride coating on the upper face side of the primary backing greatly increased the flame-retardancy of this carpet.

EXAMPLE XIV A solution of 10 grams PVC copolymer (analysis: 47.2% chlorine) and 10 grams triphenyl phosphate in grams chlorobenzene was prepared and applied evenly to the top surface of jute as in Example I(b) and cured at 136 C. for 30 minutes. The add-on weight of PVC triphenyl phosphate on a dry basis was 4.2 ounces per square yard. Nylon 66 yarn of Example I(a) was tufted into the treated jute at 2.8 rows/in. and 2.8 stitches/in., and a pile height of 1% in. A hexamethylenetetramine pellet weighing 0.15 gram was placed in the center of a 5 in. square sample of the carpet structure and was ignited. The flame was not propagated and the charred area was restricted to a small area adjacent to the position of the pellet. Hence, the carpet was flame-retardant.

EXAMPLE XV A polyvinyl chloride plastisol consisting of parts vinyl chloride polymer (97% vinyl chloride and 3% vinyl acetate), 90 parts Santicizer 140 (cresyldiphenylphosphate), 3 parts epoxidized soy bean oil, 2 parts (Ba, Cd soap-heat stabilizer), and 3 parts Sb O was applied evenly to the top surface of jute, as in Example I(b), and cured at C. for 20 minutes. The add-on weight of plastisol on a dry basis was 6.8 ounces per square yard. Nylon yarn of Example I(a) was tufted into the treated jute and a hexamethylenetetramine pellet was placed on the sample and ignited as in Example XIV. The flame 1. 1 was not propagated and the charred area was restricted to a small area adjacent to the position of the pellet. Hence, the carpet was flame-retardant.

EXAMPLE XVI A 50% aqueous emulsion latex of 35 parts of tricresyl phosphate per 100 parts of a 15/ 85 vinyl chloride/ vinylidene chloride copolymer was prepared. The latex was stabilized with 2% anionic emulsifier. This latex was evenly spread along the top side of a 3.4 ounces per square yard nonwoven nylon 66 fabric (Cerex by Monsanto Company St. Louis, Mo.). The coated backing was cured in a hot air oven at 105 C. for 25 minutes and then cooled. The plied nylon 66 yarn as described in Example I(a) was tufted to provide a shag construction. The carpet sample was tested for flame-retardancy using the abovedescribed pellet ignition test. It was observed that the charred area was confined to a small area.

EXAMPLE XVII (a) A 5 inch square piece of jute carpet backing was tufted with polyethylene terephthalate polyester spun staple yarn individual denier, total denier 6984) at a weight of 30 ounces per square yard, at 2.8 roWs per inch and 4.2 stitches per inch. The sample was cured minutes at 150 C. A hexamethylenetetramine tablet was placed in the center of the sample and ignited. The flame was propagated along the surface of the sample for a period of 8 minutes before it was extinguished, burning a large area of the sample. Hence, the carpet was not flame-retardant.

(b) A 5 inch square piece of jute carpet backing was treated on the face surface as in Example I(b), with :1 solution of 10 grams vinyl chloride polymer (97% vinyl chloride, 3% vinyl acetate) and 10 grams triphenyl phosphate in 80 grams chlorobenzene, and cured at 150 C. for 20 minutes. The add-on weight of PVC/triphenyl phosphate was 4.9 ounces per square yard. The sample was tufted with polyester yarn as in Example XVII(a), cured 20 minutes at 150 C., and a hexamethylenetetramine tablet was placed in the center of the sample and ignited. The flame was not propagated and the charred area was restricted to a small area adjacent to the position of the tablet. Hence, the carpet was flameretardant.

EXAMPLE XVIII (a) A 5 inch square area of Loktuft polypropylene carpet backing was tufted with polyester yarn of the type described in 'Example XVII(a), exactly as in Example XVII(a), at a weight of ounces per square yard. A secondary Loktuft backing was latexed with 26 ounces per square yard of L-l254 latex and married to the tufted backing with hand press; the sample was then cured 40 minutes at 106 C. A hexamethylenetetramine tablet was placed in the center of the carpet sample and ignited. The flame was propagated along the surface of the sample for a period of 6 minutes before it was extinguished, burning a large area of the sample. Therefore, the carpet was not flame-retardant.

(b) A 5 inch square area of Loktuft carpet backing was treated on the face surface, as in Example I(b), with a solution of 10 grams vinyl chloride polymer (97% vinyl chloride, 3% vinyl acetate) and 10 grams triphenyl phosphate in 80 grams chlorobenzene, and cured at 106 C. for 20 minutes. The add-on weight of PVC/triphenyl phosphate was 1.3 ounce per square yard. The sample was tufted with polyester yarn and backed with a secondary backing of Loktuft, as in Example XVIII(a), and then cured 40 minutes at 106 C. A hexamethylenetetramine tablet was placed in the center of the sample and ignited. The flame was not propagated and the charred area was restricted to a small area adjacent to the position of the tablet. Therefore, the carpet was flameretardant.

12 EXAMPLE XIX (a) A 5 inch x 5 inch square area of Loktuft polypropylene carpet backing was tufted With 3690 denier nylon 66 yarn as described in Example I at a weight of 22 ounces per square yard. A secondary Loktuft backing was latexed with 26 ounces per square yard of L-1254 latex and married to the primary backing; the sample was then cured 40 minutes at 106 'C. A hexamethylene tablet was placed in the center of the sample and ignited. The flame was propagated along the surface of the sample for a period of 11 minutes before it was extinguished, burning a large area of the sample. Therefore, the carpet was not flame-retardant.

(b) A 5 inch x 5 inch square area of Loktuft carpet backing was treated on the face surface, as in Example I(b), with 15% vinyl chloride, vinylidene chloride copolymer latex and cured 40 minutes at 106 C. The add-on weight on a dry basis was 6.9 ounces per square yard. The sample was tufted with nylon 66 yarn as described in Example I and latexed with L-l254 as in Example XIX(a) and cured 40 minutes at 106 C. A hexamethylene tetramine tablet was placed in the center of the sample and ignited. The flame was not propagated and the charred area was restricted to a small area adjacent to the position of the tablet. Therefore, the carpet was flame-retardant.

EXAMPLE XX A PVC plastisol consisting of parts vinyl chloride polymer (97% vinyl chloride and 3% vinyl acetate), 60 parts n-butyl benzyl phthalate and 30 parts dioctyl phthalate, was applied evenly to the top surface of jute carpet backing fabric as in Example I(b), and cured at C. for 20 minutes. The add-on weight of the plastisol on a dry basis was 26.1 ounces per square yard. Nylon yarn of the type described in Example I(a) was tufted into the treated jute. 1A hexamethylenetetramine tablet was placed on the sample and ignited. The flame was propagated along the surface of the sample for a period of 9 minutes 36 seconds; the burn covered a large area of the sample before it was extinguished. Hence, the carpet with a jute backing even coated with vinyl chloride polymer plus an organic PVC plasticizer (not containing phosphorous) was not flame-retardant.

We claim:

1. A flame-retardant carpet structure comprising:

(a) yarn pile of synthetic filaments or fibers made of a polymer selected from the group consisting of polyester, polyamide, and polyolefins;

(b) a primary carpet backing having a top surface and an underside surface into which the pile yarn is placed to present a pile surface extending from the top surface of the said backing;

(c) a coating of a film-forming polyvinyl chloride polymer containing a water insoluble organic phosphate ester having the formula wherein R R and R are the same or different monovalent radicals selected from the group consisting of an aliphatic radical of 1-24 carbon atoms with up to three double bonds between the carbon atoms, an alicyclic radical and an aromatic radical, said phosphate ester constituting 15 to 60 percent by weight of the coating, said coating applied to and confined essentially to the top surface of the backing without substantial penetration of the yarn pile of 13 the coating, the weight of the coating being 1.5 to 10 ounces per square yard of backihg on a nonvolatile content basis.

2. The carpet as defined in claim 1 wherein the backing is selected from the group consisting of a plain weave jute structure, non-woven nylon, and non-woven polyolefin.

3. The carpet as defined in claim 1 wherein the phosphate ester is Z-ethylhexyl diphenyl phosphate.

4. The carpet as defined in claim 1 wherein the phosphate ester is triphenyl phosphate.

5. The carpet as defined in claim 1 wherein the phosphate ester is cresyl diphenyl phosphate.

14 References Cited UNITED STATES PATENTS 3,348,992 10/1967 Cochran 161-67 5 3,041,707 7/1962 Perri "161- 67 3,535,192 10/1970 Gamble 1 61-67 FOREIGN PATENTS 1,161,078 8/1969 Great Britain 161403 10 WILLIAM J. VAN BALEN, Primary Examiner US. Cl. X.R.