US2358871A - Textile treatment - Google Patents

Description

Patented Sept. 26, 1944 'mx'rmr: murmur Robert William Maxwell, Wilmington, DeL, as-

signor to E. I. du Pont de Nemours & Company, Wilmington, Del., a corporation of Delaware No Drawing. Application May 20, 1940, Serial No. 336,313

7 Claims.

This invention relates to the treatment of textiles and more particularly to the waterproofing of textiles.

This invention has as an object the treatment of textiles. A further object is the provision of a process for waterproofing textiles. Other obiects will appear hereinafter.

These objects are accomplished by the following invention wherein a fabric, particularly a cellulosic fabric, is treated with a lower monobasic monocarboxylic acid ester of an N-monomethylolamide of a higher monobasic monocarboxylic acid, and subsequently baked at a temperature above 70 C.

The following examples wherein the parts are by weight and the temperatures are in'degrees centigrade illustrate the preparation of the agents whereby the fabric is to be treated.

Example A Ten parts of a mixture of methylolamides melting at 105, derived from commercial stearamide and containing approximately equal proportions of methylolstearamide and methylolpalmitamide is mixed with 30 parts of acetic anhydride. At room temperature no sign of reaction occurs. The mixture is then heated at 70 for two hours. The methylolamide soon dissolves. Upon cooling, the reaction mixture forms a white crystalline pulp. The crystals are filtered oil and washed with cold benzene. The product is much more soluble in benzene and ethyl alcohol than the original mixture of methylolamides. It consists of plates melting at 87". Found: C, 69.7; H, 11.8 Calculated for an equimolar mixture of palmitamidomethyl acetate and stearamidomethyl acetate; C, 69.7; H, 11.4. Saponification number found, 158.5; calculated 164.2.

A mixture of equal parts of acetic acid and acetic anhydride may be used in place of the acetic anhydride. The product obtained is identical in its properties.

The methylolstearamide is prepared by mixing 255 parts of commercial stearamide with 1150 parts of ethanol at room temperature, heating the mixture to 50, adding 116 parts of 37% aqueous formaldehyde and thereafter 30 parts of 31% aqueous sodium hydroxide, heating the mixture for 1 hour at 50, cooling and filtering. The product melts at 104. Paraformaldehyde may be used in place of the formalin but the latter is preferred. Other alkaline catalysts, e. g. NazCOa may be employed.

action between the formaldehyde, amide and acylating agent simultaneously.

Example B Ten parts of methylolstearamide is heated with 30 parts of acetic acid containing 2 parts of concentrated sulfuric acid at for two hours. The product obtained is the same as that produced by Example A but several recrystallizations from benzene are necessary in order to obtain the same melting point.

The process of the above examples yields the acetate of the methylol derivative of commercial stearamide which is a mixture consisting essentially of stearamide and palmitamide with small and, for the purposes of the invention, negligible amounts of other long chain amides.

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 Fourteen parts of methylolstearamide prepared from commercial stearamide iS heated on a steam bath for 4 hours with 50 parts of glacial acetic acid. Two pieces of unfinished mercerized cotton broadcloth are steeped in the acid reaction mixture for two minutes, wrung out thoroughly, and dried. The fabrics are then heated in an oven at for 30 and 60 minutes respectively. The fabrics are very water repellent and retain a high proportion of their water repellence even after thorough washing with benzene.

Example II Ten parts of stearamide is heated on a steam bath with ten parts of acetic anhydride of 90% strength and 2 parts of paraformaldehyde for 16 hours. The resulting product, which is very soluble in benzene, is diluted with benzene to a concentration of 5% based on the stearamide. Four samples of unfinished mercerized cotton broadcloth are impregnated with this solution, after which they are dried at room temperature. The samples are then heated at for 10, 30, 55, and 80 minutes, respectively. The samples are washed quickly in warm dilute soap solution and after thorough rinsing with water are tested for water repellency. The sample heated for 10 minutes shows moderate water repellency, the sample heated for 30 minutes shows good water repellency, while the samples heated for 55 and In some instances it is possible to efiect re- 55 80 minutes are of excellent water repellency, the

55 minutes sample being about as good as that prepared by heating for 80 minutes.

Example III A reaction mixture is prepared in the manner described in Example 11. The hot reaction mixture is emulsified by pouring it, with very vigorous agitation, into 250 parts of a 0.5% aqueous solution of sodium dodecylsulfate at the boiling point. Six pieces of unfinished mercerized cotton broadcloth are steeped in the emulsion for 5. minutes. They are then wrung through a wringer and dried at room temperature after which three are heated at 170 for 5, 10, and 20 minutes, respectively, and the remaining three are heated at 130 for 20, 55 and 105 minutes, respectively. The fabrics; after bakingare agitated vigorously for 3 minutes in a .2% soap solution at 160 F. after which they are rinsed well and ironed. All the samples possess an excellent degree of water repellence. The fabrics are laundered by boiling for 2 hours with a .4% soap solution containing .2% soda ash, after which they are rinsed thoroughly and ironed again. The water repellence is only very slightly lowered by the treatment. The laundered samples are found to possess a high degree of water repellence even after extraction with benzene.

Example IV A 5% solution in benzene is made from the acetyl derivative of methylolstearamide. Pieces of mercerize-d unfinished cotton broadcloth, previously impregnated with 1% of lactic acid and dried, are impregnated with the solution, wrung until the weight of fabric plus solution equaled u R CO being the acyl radical of a monobasic monocarboxylic acid having a monovalent aliphatic hydrocarbon open chain of at least seven carbon atoms and R being a monovalent aliphatic hydrocarbon radical of not more than three carbon atoms. Thus R may be heptyl, nonyl, cyclohexyldodecyl, a-brocmostearoyl, a-methoxylauryl, decenyl, heptadecenyl, decyl, undecyl, tridecyl, heptadecenyl, heptadecyl, henneadecyl, 0- and p-dodecylphenyl, o-stearoxyphenyl and their halogen substitution products and R may be methyl, ethyl, propyl and isopropyl. In the preferred class R is an aliphatic hydrocarbon radical and R. is methyl.

Esters of methylolamides derived from shorter chain acids 'but which also contain an aliphatic chain of at least seven carbon atoms may be employed, for example, that obtained by reacting acetic anhydride with octadecyl N-methylolcarbamate. This compoundis an ester of the methylolamide of octadecyloxyformic acid and illustrates the use of esters of methylolannides of acids wherein the carboxyl is separated from the long aliphatic chain by an intervening group.

The methylolaimides from which the esters involved in the present invention may be derived may be aliphatic or aromatic. cyclic or acyclic, homocyclic qr heterocyclic, saturated or unsaturated in the alkyl or acyl chain, straight or branched chain, and substituted or not by inert groups such as halogen, ether, ketone, ester, sulflde, nitrile, and other groups. Mixtures of two or more of any of these types of methylolamide esters may be and frequently are used to advantage because they are often obtained as mixtures which are difiicultto separate.

The process of Shipp Serial Number 245,931 filed December 15, 1938, now Patent No. 2,232,485, is of particular value in preparing the treating agents.

While the process of the present invention is of particular value in the treatment of cellulosic textiles, it is generically applicable to any organic fibrous material, including cotton, linen, leather, silk, wool, jute, hemp, coir, sisal, paper, hair, ramie, flax, straw, alpaca, wood, and the like. The fibrous material may be in the raw state, or in some processed bulk state in which its fibrous nature is retained, such as wood pulp, or in the form of a manufacture, such as cord, thread, fibers, paper, felt, fabrics, and especially textiles. Particularly significant results are obtained with cellulosic materials, 1. e., materials having a substituted or unsubstituted cellulosic nucleus, including linen, cotton, cellulose acetate rayon, viscose rayon, and cuprammonium rayon, including rayon staple. The cellulose nucleus preferably should be unsubstituted as is the case with cellulosic fabrics made from cotton, linen, and the rayons obtained by the viscose and cuprammonium processes.

The heating of the fabric after impregnation with the amide ester may be conducted at 70 to 225 C. but ordinarily is done at -175 C. with preferred results being obtained at l00-160 C. The time of heating will depend upon the activity of the particular agent employed. Times of reaction up to 30 minutes have been found satisfactory. Times of reaction up to one hour are permissible with reagents which react slowly.

, The heating should always be carried out within such intervals as are not too great to harm the fibrous material seriously, i. e., impair its fibrous structure. This is at most a matter of simple test.

The impregnation of the textile may be from non-aqueous solutions of the ester amide, e. g., in benzene, toluene, xylene, ethylene dichloride, ethyl acetate, dioxan, methyl ethyl ketone, trichloroethylene, diisopropyl ether, carbon tetrachloride or other inert organic solvent or from aqueous dispersions. Any suitable dispersing agent may be employed to prepare the emulsions. for example, alkali salts of alkylsulfuric acids such as dodecylsulfuric and octadecenylsulfuric acids, of alkylnaphthalenesulfonic acids, e. g., isopropylnaphthalenesulfonic acid, quaternary ammonium salts having a long chain attached to the nitrogen, e. g., cetyltrimethylammonium bromide and laurylpyridinium bromide, and, in alkaline or neutral solution, alkali metal soaps. Acidic materials are preferably present, e. g., weak acids such as citric, lactic tartaric, phthalic, or succinic acid, acid salts, e. g., ammonium dihydrogen phosphate or acid forming salts, e. g., ammonium chloride. Treatment in neutral solution or in solutions made alkaline, e. g., with sodium carbonate, sodium hydroxide, tertiary amines, etc. is within the scope of this invention. The application of the shorter chain methylolamide esters from aqueous emulsions, while in some instances possible if manipulation is rapid, is not recommended because the compounds are more and more sensitive chemically to water as the chain length decreases. If the methylolamide ester is a solid, it may be melted and the fibrous body immersed in the melt. Similarly, if it is normally a liquid, the fibrous substance may be steeped therein in the absence of a solvent. These methods, however, are not recommended since the results are not as uniform as are obtained with solvents.

The quantity of treating mixture that may be applied to the fibrous material is usually determined by the ability of the fibers to absorb liquid. Thus, where the fibers are in loose form a weight of solution equal to as much as three times the weight of the material is easily absorbed. On the contrary, if the fibrous surface is compact, the fibrous body may absorb only a small fraction 'of its weight. This, however, is substantially immaterial since detectable efiects are obtained with amounts oi pure methylolamide ester as low as 0.1% by weight based on the fibrous material. On the other hand, as much as 20% or more may be applied by proper regulation of the concentration of the treating solution.

Following application of the methylolamide ester, the excess treating solution is preferably removed. This is most conveniently accomplished by wringing, centrifuging, or by any similar wellknown procedure. The residual solvent or dispersion medium may next be, and usually is, removed by evaporation. Where an aqueous emulsion of a higher methylolamide ester has been used, it is usually advantageous to remove the water at a temperature below 60 C. in order to prevent or minimize the action between the water and the ester during the drying step. However, preliminary drying is not necessary when the agent has been applied from an aqueous emulsion if the baking treatment is applied under such conditions that the fabric can be dried rapidly at an' elevated temperature. Where drying at elevated temperatures takes place rapidly (5 minutes or less) little reaction with the water seems to occur during this step. When the ester has been applied from an organic solvent solution, the conditions which may be used for drying need not be so carefully controlled. Fire hazards are minimized by drying at low temperatures, however, and for this reason drying temperatures of (SO-100 C. are recommended in the case of organic solvents.

The new agents may be used in conjunction with other treating agents or processes. Suitable effective combinations may be produced with resins, waxes, softening agents, sizes, formaldehyde, urea, dimethylolurea, and the like. Good effects are obtained when treatments are applied simultaneously or consecutively with creaseprooflng processes.

The process of the present invention is of advantage in afl'ordlng a convenient process for rendering textiles, particularly cellulosic textiles, waterproof.

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 of increasing the water resistance of a textile fabric which comprises impregnating the same with a dispersion of a preformed lower monobasic monocarboxylic acid ester of an N- monomethylolamide of a monobasic monocarboxylic acid of at least eight carbon atoms and baking the same.

2. Process of increasing the water resistance of a cellulosic textile fabric which comprises impregnating the same with a dispersion of-a preformed lower monobasic monocarboxylic acid ester of an N-monomethylolamide of a monobasic monocarboxylic acid of at least eight carbon atoms and baking the same.

3. Process of increasing the water resistance of a cellulosic textile fabric which comprises impregnating the same with a dispersion of a preformed lower monobasic monocarboxylic acid ester of an N-monomethylolamide of an aliphatic monobasic monocarboxylic acid of at least eight carbon atoms and baking the same.

4. Process of claim 2 wherein an acidic material is employed as a catalyst.

5. Process of claim 2 wherein the dispersion is a solution in an inert solvent.

6. Process of increasing the water resistance of a cellulosic textile fabric which comprises impregnating the same with a preformed acetate of an N-monomethylolamide of a higher aliphatic monobasic monocarboxylic acid and baking the same.

7. Process of increasing the water resistance of a cellulosic textile which comprises impregnating the same with preformed stearamidomethyl acetate and baking the same.

ROBERT WILLIAM MAXWELL.