US2335582A

US2335582A - Fabric and finish

Info

Publication number: US2335582A
Application number: US363571A
Authority: US
Inventors: Coffman Donald Drake
Original assignee: EI Du Pont de Nemours and Co
Current assignee: EIDP Inc
Priority date: 1940-10-30
Filing date: 1940-10-30
Publication date: 1943-11-30
Anticipated expiration: 1960-11-30

Description

Patented Nov. 30, 1943 UNITED STATES PATENT OFFICE FABRIC AND FINISH Ne Drawing. Application October so, 1940, Serial No. 363,571

15 Claims.

This invention relates to processes for water repellent finishes for textiles and to water repellent textiles therefrom.

Unmodified synthetic or natural textile fibers as a whole are not water-repellent, and water repellency is an unnatural but desirable property for them. Fabrics or yarns have, for many years, been rendered water-repellent by treatment with waxy materials, but fabrics prepared according to older processes have, in general, suffered from lack of resistance to laundering or dry-cleaning. The new water-repellent agents and treatments that have been developed in recent years give fabrics whose water-repellent properties are resistant to laundering, but many of thes processes are based on expensive chemicals and/or involved or complicated treatments.

This invention has as an object the provision of a simple process whereby readily accessible chemicals are employed to give fabrics whose water-repellent properties are durable toward laundering- Another object is the provision of a process for altering the hand of fabrics. Another object is the provision of a process for giving a permanent softening effect. A further object comprises the water-repellent textile thus obtained. Other objects will appear hereinafter.

These objects are accomplished by the following invention wherein a textile material is impregnated with a copolymer of a polymerizable vinyl or vinylidene compound with an organic compound containing an ethylenic double bond and an --NCX group, X being an element of the sixth group of the periodic system having an atomic weight less than 33, said NCX group being removed from a carbon bearing the ethylenic double bond by not more than one intermediate carbon atom, which, when present, has its remaining valences satisfied by one oxygen atom and curing the impregnated textile at an elevated temperature.

In its preferred form, the invention is carried out by first impregnating the fabric with a solution containing the selected copolymer as above defined preferably a copolymer of a l-alkenyl isocyanate or an alpha,"beta-unsaturated acyl isothiocyanate with a, polymerizable vinyl or vinylidene compound, removing the solvent by drying, and subsequently heating the fabric to effect reaction. The selected copolymer in solution form is introduced into the fabric by impregnation followed by squeezing with pressure rolls or by centrifugal wringing or by air drying, or a solution of the copolymer can be sprayed into the fabric at a controlled rate using a fine. spray. In addition to its application from solution, it can be applied in liquid form provided the copolymer melts below the temperature of -application usually therefore below 100 C. Since only'a small amount of the copolymer is required to effect water repellence, the application by solution method is favored because small amounts of the agent can be uniformly distributed throughout the fabric. The fabric should b thoroughly dried before treatment with the selected copoly-- mer, which is applied from solution in an unreactive, nonhydroxylated, anhydrous solvent, e. g., benzene, toluene, or carbon tetrachloride. This minimizes loss of reagent due to side reactions. The agent can also be applied in undiluted form at temperatures slightly above its melting temperature, but this requires a wasteful excess of the reagent, as noted above, and when such a method is used, it is preferable to operate at temperatures less than 150 C. to avoid damage to the fabric. The excess agent can be satisfactorily removed by the same means that were employed in the removal of the excess solution of the agent.

Copolymers of l-alkenyl isocyanates with polymerizable vinyl or vinylidene compounds may be synthesized as described in the copending applications of Donald D. Coffman, Serial Number 355,412, filed September 4, 1940, and Serial Number 355,411, filed September 4, 1940. Copolymers of alpha, beta-unsaturated acyl isothiocyanates with polymerizable vinyl or vinylidene compounds may be synthesized as described in the copending application of Van V. Alderman and and baked for 5 minutes at 150 C. Tests show Donald D. Coifman, Serial Number 326,786, filed March 29, 1940.

The more detailed practice of the invention is illustrated by the following examples, wherein parts given are by weight. There are of course many forms of the invention other than these specific embodiments.

Example I 'A piece of cotton jean cloth is dipped into a 4% benzene solution of 5% methacrylyl isothiocyanate-95% styrene copolymer softening at 101 C. and having a Pfund hardness of 320 which is prepared by heating 5 parts of methacrylyl isothiocyanate, 95 parts of styrene and one part of benzoyl peroxide to 70 C. The cloth is air dried that the cloth has an initial repellency of and a repellency of 40 after laundering. A repetition of the experiment using a 2% benzene solution of the methacrylyl isothiocyanate-styrene copol- 1 will, when inclined at a 45 angle, completely re- P 1 250 cc. of water at F. sprayed from a height of 6 inches directly above the fabric, and

none of the water will stick to the fabric. A repellency 0f indicates that few drops of water cling to the cloth but can be completely removed by shaking. A repellency of 50 means'that the upper surface of the cloth is wetted under the experimental conditions, but the water does not penetrate the cloth. These are taken as reference points in appraising water repellency. The laundering treatment consists in boiling the sample in a 0.1 per cent neutral soap solution for one hour, rinsing thoroughly and drying.

' Example II A piece of cotton jean cloth is dipped into a 2% chloroform solution of the copolymer of isopropenyl isocyanate (30%) and methyl methacrylate softening at 87 and having a Moh hardness of 2.5, prepared by exposing a mixture of 30 parts of isopropenyl isocyanate, '70 parts of methyl methacrylate and 3 parts of benzoyl peroxide to the light from a mercury are for two weeks at 30 C. The cloth is immediately air dried in front of an electric fan and baked for 5 minutes at 150' C. The cloth has an initial repellency of 80 and a repellency after laundering of 80.

In none of these treatments is tendering of the fabric observed.

The process of this invention may be applied to all types of organic textile materials, and particularly to cellulosictextile materials. ,Silk and wool natural fibers, viscose rayon, acetate rayon, cuprammonium rayon, and other synthetic fibers are capable of being improved in water-repellency in the manner described in the examples. In addition to the organic textile materials named,

other materials such as cotton, linen, hair, ramie,

fiax, alpaca, and the like are improved in water repellent properties by the process of this invention. The dry fibrous material may be in either the raw state, such as wool or cotton, or in any processed state in which the fibrous nature is retained such as fabrics, threads, cords, etc. Cellulosic materials, either unsubstituted or partially substituted, such as linen, cotton, cellulose acetate rayon, viscose rayon, cuprammonium rayon, and staple rayon, react particularly well with the water-repelling agent. Best results, however, are obtained with a cellulose material, 1. e., one wherein the cellulose nucleus is unsubstituted as is found, for example, in cotton, linen, and in rayon prepared either by the viscose or cuprammonium process. The best results are obtained when the material to be treated is devoid of size, starch, and other extraneous finishing materials.

These organic fibrous materials may be-treated in the liquid phase with any copolymer of an organic compound having the NCX group as above defined, which is removed from a carbon bearing an etl'rvlenic double bond by not more than one carbon atom which, if present, has its remaining valences satisfied by one oxygen atom, with a different polymerizable organic compound, said polymerizable organic compound being free of functionalities capable of reaction with the isocyanate group.

Perhaps the most important class of polymerizable -NCX compounds which can be employed to form'copolymers is that .of the l-alkenyl isocyanates of the formula RR'C=CR."NCO in which R, R and R", either alike or different, can be hydrogen and vmonovalent organic radicals .saturated and unsaturated such as acyclic, alicyclic, alkoxy, aryl, aroxy, and heterocyclic, which obviouslyare free of embodied or substituent functionalities capable of reaction with the isocyanate group. Examples of this class are isopropenyl," l-butenyl, Z-butenyl, l-phenylvinyl,

propenyl, l-methylpropenyl, styryl, l-p-c oro- 75' aliphatic hydrocarbon residues, heterocyclic and alkoxy radicals, saturated or unsaturated, and in general any organic radical that possesses no embodied or. substituted group or groups capable of reaction with the isothiocyanate group, and more particularly that contains no reactive hydrogen atoms. Examples'of this class are acryl isocyanate and isothiocyanate, methacrylyl isocyanate and isothiocyanate, alpha-chloroacrylyl isocyanate and isothiocyanate, cinamoyl isothiocyanate, and p-nitrocinnamoyl isothiocyanate.

Any polymerizable vinyl or vinylidene compound may be employed for the copolymerization including methyl methacrylate, methacrylonitrile. methacrylamide, methyl alpha-chloroacrylate, alpha-chloroacrylonitrile, methyl acrylate,acry1onitrile, chloroprene, divinylacetylene, monoviylacetylene, butadiene, isoprene, vinyl acetate, styrene, vinyl chloride, unsymmetrical dichloroethylene, and vinyl bromide. Copolymers of the polymerizable compounds discussed above may vary from 1% of one ingredient to 99% of the same ingredient depending upon the ease of polymerization and the properties desired in the final prod uct. Y

If the repellent agent is normally liquid or is a low melting copolymer, i. e., melting below about C., the fabric may be steeped therein in the absence of a solvent and even heated without being removed. This avoids the step of removing excess of the repellent agent before curing, or the excess repellent agent can be removed by squeezing through rollers, wringing, or centrifuging before the baking step. These methods are not recommended, however, since the results are not always uniform and the expense of application is greater than when a solvent is used.

Application of the water repelling agent from solution offers several advantages, such as excluding moisture and giving uniform treatment with an adequate amount of the water repelling agent. In the general practice of this invention the material under treatment is steeped in a 5 to 10% solution of the selected copolymer in an inert solvent at room temperature. One to several minutes of soaking usually sufilces for penetration, or one or more immersions in the solution adequately wets the fabric and excess solvent is conveniently removed by wringing, centrifuging, drying in a current of air, or any other known procedure, care being observed to elimi-' to 150 C. is in general satisfactory for this purpose. At such temperatures the agent is highly effective and the fibers do not suffer serious degradation. Generally, however, the rate of reaction or curing is slow and a temperature of at least 90 C. is recommended in order that the reaction be feasible from a. time standpoint. In a few cases where the agent is rather inert, high temperatures are required to effect reaction although curing above 200 C. should nearly always be avoided unless the reaction can be carried out very rapidly. The time of heating will depend upon the reactivity of the particular water-repelling agent. A reaction time, i. e. time of heating, of minutes in a number of cases has been found to be satisfactory. Times of reaction up to one hour are permissible with agents which react slowly. The heating should never be allowed to proceed long enough to harm the fibrous materials. The temperature selected for the reaction depends primarily upon the reactivity of the agents employed, and the heat stability of the fibrous materials to be treated.

The water-repelling agents may be used in conjunction with other treating agents or processes provided there are no functionalities present in the second agent that will react with the NCX group ofthe copolymer. Such products as resins. softening agents, textile sizes, and finishing agents meeting the above restrictions can be used to advantage. Treatments may be applied simultaneously, but preferably consecutively in crease-proofing processes.

4. Process which comprises impregnating a cellulosic material with a copolymer of a l-alkenyl isocyanate with a diiferent. compound which is a member of the class consisting of polymerizable vinyl and vinylidene compounds and heating the impregnated material at 70- 200 C.

5. Process which comprises impregnating an organic textile material with a copolymer of an aliphatic alpha, beta-unsaturated acyl isothiocyanate with a' different compound which is a member of the class consisting of polymerizable The process is primarily applicable to the production of durable water repellent textiles. The use of quantities, either excessive, or too small to produce water repellency will impart to fabric a permanent alteration in hand, such as, in the latter case a permanent softening that will not be destroyed by laundering.

The above description and examples are intended to be illustrative only. Any modification of or variation therefrom which conforms to the spirit of the invention is intended to be included within the scope of the claims.

What is claimed is:

1. Process which comprises impregnating i an organic textile material with a copolymer of a member of the class consisting of polymerizable vinyl and vinylidene compounds with a member of the class consisting of l-alkenyl isocyanates, aliphatic alpha, beta-unsaturated acyl isocyanates and aliphatic alpha, beta-unsaturated acyl isothiocyanates and heating the impregnated material at 70-200 C.

2. Process which comprises impregnating a cellulosic textile material with a copolymer of methyl methacrylate with a member of the class consisting of 1-alkenyl isocyanates, aliphatic alphabets-unsaturated acyl isocyanates, and aliphatic alpha, beta-unsaturated acyl isothiocyanates, and heating the impregnated material l-alkenyl isocyanate with a different compound which is a member of the class consisting of polymerizabie vinyl and vinylidene compounds and 70' thi heating the impregnated material at'lO-QOO' C.

vinyl and vinylidene compounds and heating the impregnated material at IO-200 C.

6. Process which comprises impregnating a cellulosic material with a copolymer of an allphatic alpha, beta-unsaturated acyl isothiocyanate with a different compound which is a memberof the class consisting of polymerizable vinyl and vinylidene compounds and heating the impregnated material at -200 C.

7. Process which comprises impregnating a cellulosic material with a copolymer of isopro- D yl isocyanate' with a diiferent compound which is a member of the class consisting of polymerizable vinyl and vinylidene compounds and heating the impregnated material at 70- 200 C.

8. Process which comprises impregnating a cellulosic material with a copolymer of isopropenyl isocyanatewith methyl methacrylate and heating the impregnated material at 70-200 C.

9. Process which comprises impregnating a cellulosic material with a copolymer of methacrylyl isothiocyanate with a diiferent compound which is a member of the class consisting of polymerizable vinyl and vinylidene compounds and heating the impregnated material at 70- 200 C. 10. Process which comprises impregnating a cellulosic material with a copolymer of methacrylyl isothiocyanate with methyl methacrylate and heating the impregnated material at '10- 200 C.

11. Process which comprises impregnating a cellulosic material with a copolymer of methacrylyl isothiocyanate with styrene and heating the impregnated material at 70-200 C.

12. Process of claim 11, wherein the textile material is 'a cotton textile material.

13. Process which comprises impregnating a celluiosic textile material with a copolymer of a member of thesclass consisting of polymerizable vinyl and vinylidene compounds with a member of the class consisting of i-alkenyl isocyanates, aliphatic alpha, beta-unsaturated acyl isocyanates, and aliphatic alpha, beta-unsaturated acyl isothiocyanates, and heating the impregnated material at 70-200 C.

14. Process of claim 13, wherein the textile material is a cotton textile material.

15. A water-repellent organic textile material having incorporated at least on the surface thereof the reaction residue of a copolymer of a mem-' her or the class consisting of poiymerizable vinyl and vinylidene-compounds with a member of the class consisting of l-alkenyl isocyanates, aliphatic alpha. beta-unsaturated acyl isocyanates,

and aliphatic alpha, beta-unsaturated acyl isoocyanates.

DONALD DRAKE COFI'MAN.