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Publication numberUS3912449 A
Publication typeGrant
Publication date14 Oct 1975
Filing date31 Jan 1973
Priority date31 Jan 1973
Publication numberUS 3912449 A, US 3912449A, US-A-3912449, US3912449 A, US3912449A
InventorsTrinidad Mares, Jr Jett C Arthur
Original AssigneeTrinidad Mares, Jr Jett C Arthur
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Process for preparing water repellent cotton textiles and the product
US 3912449 A
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Description  (OCR text may contain errors)

United States Patent [191 Mares et al.

[ 1 Oct.14, 1975 PROCESS FOR PREPARING WATER REPELLENT CO'ITON TEXTILES AND THE PRODUCT [76] Inventors: Trinidad Mares, 6416 Cummins St., Metairie, La. 70003; Jett C. Arthur, Jr., 3013 Ridgeway Drive, Metairie, La. 70002 [22] Filed: Jan. 31, 1973 21 Appl. No: 328,198

[56] References Cited UNITED STATES PATENTS 3,504,000 3/1970 Pittman et al 8/1 16 R 3,606,993 9/1971 Arthur et al. 8/1 16 R 3,698,856 10/1972 Pittman et al 8/116 R Primary Examiner-Stephen J. Lechert, Jr.

[ ABSTRACT Cotton and other cellulosic textiles have been reacted with hexafluoroisopropyl acrylate (6F1PA) in a freeradicalinitiated graft-copolymerization process to form durable cellulosic-copolymer products which have imparted water repellency and find utility in rainwear, tents, awnings, sails and the like goods. The imparted water repellency is durable to laundering and normal weathering.

2Claims, N0 Drawings PROCESS FUR PREPARING WATER REPELLENT COTTON TEXTILES AND-THE PRODUCT A non-exclusive, irrevocable,"rQyaIty freelicense in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America. g

This invention relates to a process for imparting to cotton and other cellulosic textiles the quality of water repellency. More specifically, this invention relates to a chemical process comprising the use of irradiation of the cellulosic textile with a radioactive source to form a free radical, then reacting with hexafltioroiso propyl acrylate to form a graft copolymerwith water 'repel-.

lency properties. Obviously, these cellulosic textiles find utility in the garment industry for use in rain wear, tents, awnings, sails, etc. The imparted water repellency has been found durable to weathering as well as ordinary laundering. I

. H HEXAFLUOROISOPROPYLA FgC-C-CF,

ACRYLATE l (6F1PA) (I) i c=cH 1-1 The uses of cotton in both personal and industrial out-of-dooruses have been limited due to the low degree of water repellency of the cotton textile products. Usually, the water repellency properties of cotton textile products have been improved by weaving of heavier and more densely or tightly fitted cotton fabrics or by coating cotton fabric, which is normally woven, with materials which have water repellent properties. Weaving of a heavier and more densely or tightlyfitted cotton fabric greatly increases the cost of the textile product thereby restricting its usage to only high cost items. Coating of less expensive cotton fabrics, which are normally woven, with water repellent materials gives products with limited uses due to the often drastic reduction in desired natural textile properties, such as breaking and tearing strengths, and to the loss of the coating material during normal usage, thereby limiting the duration of time of useful value of coated cotton products which retain water repellent properties.

The instant invention defines a distinct improvement in the textile properties of water repellent cotton textiles, in both printcloth and sateen fabrics, by reaction of. radiation-activated cotton fabrics with hexa- .sociation of Textile ,Chemists andColOl l'ists for spray ratings, on a scale from O to 100, is greaterthan that for unmodified cotton fabrics which norrrially have spray ratings of O. The water repellency ofthe cotton copolymer fabrics is further increased when they areheated or cured at elevated temperatures. Wehave alsoifoun d that cottoncopolymer-fabrics prepated by the method of this invention retain a high percentage .of desirable natural properties of cotton fabrics and in many cases,

proved as compared with the desirable natural properties of unmodified cotton fabrics. For example, we have found by the method of this invention that the flex and flat abrasion resistance of the cotton copolymer fabrics are as good-as, or in most cases, better than those of unmodified cotton fabrics. The breaking strenghts of the cotton copolymer fabrics are equal to or greater than the breaking strengths of unmodified cotton fabrics. I The tearing strengths of the cotton copolymer fabrics are about percent or greater of those properties of unmodified cotton fabrics. The instant invention therefore defines a distinct improvement in permanently adding the property of water repellency to cotton textile fabrics with little or no loss of, and in most cases,

improvement of the desirable natural textile properties of cotton fabrics.

Samples of cotton fabrics used were either printcloth (about 3.4 ounces per square yard, 84 X 77 thread count) or sateen (about 7.5 ounces per square yard) and were commercial grey cloths which had been enzymatically desized, alkali scoured, and peroxide bleached on a pilot plant scale. Samples of the cotton fabrics were dried overnight at 50C to a moisture contentof about 0.5% and then irradiated with cobalt-6O gamma radiation to a dosage of about one megarad at ambient temperature (about 25C) in a nitrogen atmosphere in sealed glass tubes thereby producing longlived free radicals on the cellulose molecules of-cotton.

Radiation-activated cotton fabric (about 1 part) was immersed at 25C in a solution (about 6 parts) of hexafluoroisopropyl acrylate (about 9 volume-%),-methanol (about 73 volume-%), and water (about 18 volumewhich had been purged with nitrogen for the reaction time to give the desired poly(hexafluoroisopropyl acrylate) add-on. After the desired reaction time, the

cotton copolymer fabrics were washed with water, extracted with a solution of methanol (about by volume) and water (about 20% by volume) to remove the unreacted material, again washed with water, and then air-dried at 25C. The grafted poly(hexafluoroisopropyl acrylate) add-on of the cotton copolymer fabric was determined as the increase in weight of the cotton copolymer fabric over that of unmodified cotton fabric. Typical reaction times and percentages of poly(hexafluoroisopropyl acrylate) add-ons of the cotton copolymer sateen fabrics are as follows: 15 minutes, 6%; 60 minutes, 11%; minutes, 17%; minutes, 22%; minutes, 28%; and 240 minutes, 32%. For cotton copolymer printcloth fabrics, a typical reaction time is 8 hours for 57-58% add-0n.

The graft copolymer fabrics prepared by the process of this invention were evaluated in this manner. The

water repellency was determined by spray ratings of AATCC Method 22-1967; breaking strength was determined by ASTM Method D 1682-64; tearing strength was determined was ASTM Method D 1424-63; and flex and flat abrasion resistance were determined respectively by Paragraph 14 and 7 of ASTM Method D 1175-6.

In preliminary investigation it was determined that a quantity of oil-repellency was noted in some of the treated fabric samples but it was felt that further experimentation would be required.

The following examples are provided to facilitate the comprehension of the invention and should not be construed as limiting the invention in any manner whatsoever.

EXAMPLES To illustrate the effect of add-on of the graft copolymers samples were selected from two groups of fabrics, sateen and printcloth samples. The selected samples of grafted poly(hexafluoroisopropyl acrylate) include add-ons of to 58%. Example 1 of the tabulated data was included for comparative purposes. These selected samples are presented specifically to illustrate the effects of the chemical modification with respect to physical properties.

These copolymers were prepared by first activating the cotton cellulose with about l megarad of cobalt 60 gamma radiation, then reacting the activated cellulose at room temperature (about 25C) and controlling the degree of reaction by varying the time. The hexafluoroisopropyl acrylate (6F1PA) was reacted in methanol: water, 80:20 volume ratios. It was necessary in some instances to vary the concentration as well as the time in order to achieve the desired degree of add-on.

Attention is called to the increases in breaking strength when comparing the reacted samples with the untreated sample, Example l. Flex and flat abrasion is worthy of note in this comparative tabulation as well as a quantity of water repellency, for examples in Examples 2, 3, and 4. Examples and 6 illustrate the effect of curing at 160 for 5 minutes to yield spray ratings of 90 and 80, these rating indicating good water repellency imparted by the reaction. Obviously, a lighter weight fabric, as illustrated by the printcloth samples, responds favorably to the process (see Examples 8, 9, and l0).

was formed with properties as shown in Example No. 3. The copolymer fabric had a water repellency of (spray rating), breaking strength of 97 pounds, tearing strength of 5900 grams, and flex and flat abrasion resistances of 1.5 and 1.4, respectively, as compared with values for unmodified cotton sateen cloth fabric, Example No. 1.

By the method as described in the specification above, cotton copolymer sateen cloth fabric containing poly(hexafluoroisopropyl acrylate) add-on of 25% was formed and then cured at 160C for 5 minutes, Example No. 5. The cured, copolymer fabric, Example No. 5, had a water repellency of 90 (spray rating), as compared with a water repellency of 0 (spray rating) for unmodified cotton sateen cloth fabric, Example No. 1.

By the method as described in the specification above, cotton copolymer sateen cloth fabric, containing poly(hexafluoroisopropyl acrylate) add-on of 30% was formed and then cured at 160C for 5 minutes, Example No. 6. The cured, copolymer fabric, Example Textile and Water-Repellent Properties of Cotton-Poly(1-lexafluoroisopropyl Acrylate) Copolymer Fabrics Grafted Example Polymer Breaking Tearing Resistance' Spray Rating' No. Add-on Strength Strength Not 71 lb. g. Flex Flat Cured Cured" Sateen Cotton Fabrics 1 O 88 0 1.0 1.0 0 2 11 88 6050 1.6 1.2 50 3 22 97 5900 1.5 1.4 50 4 28 101 5300 0.9 1.4 50 5 25 90 6 30 80 Printcloth Cotton Fabrics "Untrcated. control cotton fabric equal 1.0. Water-repellency rated on scale from 0 to 100. "Cured at 160C for 5 minutes.

By the method as described in the specification above, cotton copolymer sateen cloth fabric, containing poly(hexafluoroisopropyl acrylate) add-on of 1 1%, was formed with properties as shown in Example No. 2. The copolymer fabric had a water repellency of 50 (spray rating), breaking strength of 88 pounds, tearing strength of 6050 grams, and flex and flat abrasion resistances of 1.6 and 1.2, respectively, as compared with values for unmodified cotton sateen cloth fabric, Example No. l, of 0% add-on, 0 spray rating, 88 pounds breaking strength, 6300 grams tearing strength, and 1.0 for both flex and flat abrasion resistances.

By the method as described in the specification above, cotton copolymer sateen cloth fabric, contain ing poly(hexafluoroisopropyl acrylate) add-on of 22% No. 6, had a water repellency of (spray rating), as compared with a water repellency of 0 (spray rating) for unmodified cotton sateen cloth fabric, Example No. 1.

By the method as described in the specification above, cotton copolymer printcloth, containing poly(hexafluoroisopropyl acrylate) add-on of 27%, was formed and then cured at C for 5 minutes, Example No. 8. The cured copolymer fabric, Example No. 8, had a water repellency of 80 (spray rating), as compared with a water repellency of 0 (spray rating) for unmodified cotton printcloth fabric, Example No. 7.

By the method as described in the specification above, cotton copolymer printcloth fabric, containing poly( hexafluoroisopropyl acrylate) add-on of 33%, was

formed and then cured at 160C for 5 minutes, Example No. 9. The cured copolymer fabric, Example No. 9, had a water repellency of 90 (spray rating), as compared with a water repellency of O (spray rating) for unmodified cotton printcloth fabric, Example No. 7.

By the method as described in the specification above, cotton copolymer printcloth fabric, containing ply(hexafluoroisopropyl acrylate) add-on of 57% was formed, Example No. 10. The copolymer fabric, Example No. 10, had a water repellency of 70 (spray rating), as compared with a water repellency of 0 (spray rating) for unmodified cotton printcloth fabric, Example No. 7.

By the method as described in the specification above, cotton copolymer printcloth fabric, containing poly(hexafluoroisopropyl acrylate) add-on of 58%, was formed, Example No. 11. The copolymer fabric, Example No. 11, had a breaking strength of 36 pounds, tearing strength of 560 grams, and flex abrasion resistance of 1.7, as compared with values for unmodified cotton printcloth fabric, Example No. 7, of 37 pounds breaking strength, 770 grams tearing strength, and 1.0 flex abrasion resistance.

We claim:

1. A process for imparting to cotton and other cellulosic textiles the desirable property of water repellency, while retaining the desirable natural properties of cotton and other cellulosic textiles, by preparation of cotton-poly(hexafluoroisopropyl acrylate) copolymer printcloth or sateen fabrics, the process comprising:

a. drying the cellulosic textile to a moisture content of about 0.5%,

b. irradiating the dry cellulosic textile with a radioactitive source, in an inert atmosphere, to a dosage of l megarad,

c. immersing the irradiated cellulosic textile in a solution computed to contain proportionately, including the cellulosic textile, about 1.0 part by weight of cellulosic textile and 6.0 parts by weight of solution, containing hexafluoroisopropyl acrylate (about 9 volume-%), methanol (about 73 volumeand water (about 18 volume-%) at room temperature for periods of about 15 minutes to 8 hours to give a polymer add-on of about from 11 weight percent to about 58 weight percent based on the weight of the untreated textile, and

cl. washing the unreacted material off the treated cellulosic textile with a solution of methanol (about volume-%) and water (about 20 volume-%),

e. drying the treated and washed cellulosic textile.

2. The water repellent cellulosic textile produced by the process of claim 1.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 1 3,912,449 DATED October 14, 1975 |NVENTOR(5 3 Trinidad Mares and Jett C. Arthur, Jr.

it is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

The following statement should appear in the heading in Assignee: The United States of America; as

represented by the Secretary of Agriculture.

Signed and Scaled this tenth Day Of February 1976 [SEAL] Arrest:

RUTH C. MASON I C. MARSHALL DANN Arresting Officer Commissioner (JVIIPGNHIS and Trademarks

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3504000 *26 Jul 196731 Mar 1970Us AgricultureFluorinated glycidyl ethers
US3606993 *18 Jul 196921 Sep 1971Us AgricultureDurable press cotton textile products produced conducting graft copolymerization process followed by cross-linking with dmdheu
US3698856 *22 Nov 196617 Oct 1972Us AgricultureTreatment of textile fibers
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US630698930 Sep 199923 Oct 2001E. I. Du Pont De Nemours And CompanySitu fluoropolymer polymerization into porous substrates
US655874330 Sep 19996 May 2003E. I. Du Pont De Nemours And CompanyIn situ fluoropolymer polymerization into porous substrates
US66770339 Aug 200113 Jan 2004E. I. Du Pont De Nemours And CompanyIn situ fluoropolymer polymerization into porous substrates
US69165495 Mar 200312 Jul 2005E. I. Du Pont De Nemours And CompanyIn situ fluoropolymer polymerization into porous substrates
EP1754547A2 *26 Oct 199921 Feb 2007E. I. du Pont de Nemours and CompanyIn situ fluoropolymer polymerization into porous substrates
WO2000024528A1 *26 Oct 19994 May 2000Du PontIn situ fluoropolymer polymerization into porous substrates
Classifications
U.S. Classification8/120, 8/DIG.180, 411/930
International ClassificationD06M14/04
Cooperative ClassificationY10S411/93, Y10S8/18, D06M14/04
European ClassificationD06M14/04