US2944921A - Process for the production of water-repellent finishes on textiles and composition therefor - Google Patents

Description

TOSITION THEREFOR Leonard 'Ha'rrison Groves, John Alwyn Hall, and James .ZWilliam Roberts, Manchester, England, assignors to Imperial Chemical Industries Limited, London, England, a corporation of Great Britain NoDi-awing. Filed Mar. 24, 1958,'Ser'. No. 723,091

" ,rii 'f iflicit'iod Great Britain Mar; 27, 1957 8"Clainis. .(Cl. 117-161 \T his invention relates. to new and improved compositions'of matter of value for thetreatment of textile materials in. order to render them water-repellent.

It has jbeen proposed to use compositions containing methylolamides of fatty acids, for example methylolstearam'ide, for. the-production of water-repellent finishes on textile materials. The methylolamides to be used for thisipui-pose have been made by reaction of fatty acid amides with formaldehyde, paraformaldehyde and the like, for example by melting stearamide with paraformaldehyde or by heating aqueous mixtures containing formaldehyde and'stearamide. 'The fatty acid amides as'available in commerce comprise a mixture of the amides of a number of fatty acids of different molecular weight together with a proportion, usually about but sometimes 8% or more, of free fatty acids, and accordingly, the methylolamides as prepared by prior art processes for'use in the production of water-repellent finishes on textile materials contain considerable proportions of free fatty acids.

The compositions and processes hitherto proposed have not been entirely satisfactory, particularly in respect of the fastness of the water-repellent finishes to washing.

, We havenow found that the presence of free fatty acids in methylolamide compositions has a very considerable eifect on the degree of water repellency obtainable when the compositions are applied to textile materials, and that by reducing the proportion of free fatty acid in the composition there may beobtained compositions which give superior results when applied to textile materials.

,, [The term ffree fatty acid as used in. this specification refers to the portion of the fatty acids that is present at any stage during the manufacture of the methylolamides but is not converted to the amide or methylolamide. This free fatty acid may bepresent in the form of the "acid as such or a salt thereof, since the acid and salt will be converted into one another in varying proportions as the pH of the medium containing them is varied.

. Thus according to our invention we provide new and improved compositions useful for the production of water-repellent finishes on textile materials, containing a methylolamide of afatty acid containing at least 14 carbon atoms in the molecule, characterised in that the composition contains less than 4.0%, and preferably less than 2%, by weight of free fatty acids by weight of the said methylolamide.

If desired, the compositions of'our invention may also be used in conjunction with 'a resin precondensate for example a f urea formaldehy'de or melamine-formaldehyde precondensate. This is mostconveniently carried out by using the methylolamide of-a fatty acid and theresin precondensate' together'in the pad bath. When such a resin precondensate 'is'u'sed, however, we find that the methylolamideshould contain less than 2.5%, and prefmenin eal-[120% by weight, of free fatty acid in atent 2 order to obtain optimum improvement in the final Waterrepellent finish.

The compositions of our invention may conveniently be in theform of powders, dispersible powders, or aqueous pastes, dispersions or emulsions, but alternatively they may be in the form of non-aqueous pastes or solu tions if desired. Thus for example a dilute (O=.5-2.0%) solution of the methylolamide may be made using a suitable solvent suchas benzene -or trichloroethylene and this *solution may be used directly for application'to textiles. i

i It is preferred that the compositions be in the form of aqueous pastes or dispersions 'containing an anionic'surface active agent asthe dispersing agent, preferably in the proportion not more than 6% by weight of the methylolamide.

The compositions of our invention may be made by known methods, using as starting materials "fatty acid amides or methylolamides of such a quality that the content of free fatty acid in the final product is Within the limits specified above. In those of the prior art processes employing a dispersing agent, the amount of dispersing agent should not exceed'about 6% by weight of the methylolamide, since the use of greater amounts than this may result in the'improvements in water-repellency due to the selected quality of methylolamide being reduced by the adverse effect of the dispersing agent.

The methylolamides suitable for use in the process and compositions of our invention may be made from fatty acid amides by the prior art processes, onlyusing as starting materials fatty acid amides which have been treated to remove the undesirable fatty acids contained therein. Thus for example, the fatty acid amides may be treated by recrystallisation from a solvent which will preferentially retain the fatty acid in solution, for example benzene, toluene or trichloroethylene.

If desired, the purification of the fatty acid amide as a separate step may be avoided by carrying out the preparation of the methylolamide from fatty acid amide and formaldehyde, or a substance yielding formaldehyde, in the presence of a solvent which will preferentially retain the fatty acid in solution, for example benzene or toluene.

As examples of methylolamides of fatty acids which may be used in the compositions of our invention there may be mentioned those derived from the amides of palmitic acid, behenic acid, and mixtures containing them, and preferably from stearic acid and mixtures thereof. Mixed fatty acid amides are more readily available commercially than the pure compounds, and such commercial mixtures are satisfactory starting materials for the manufacture of the compositions of our invention.

For the purposes of economy and storage it is preferred that the compositions of our invention contain at least 20% of methylolamide, but if desired they may be sufliciently dilute for direct use. H

For use in the production of water-repellent finishes on textile materials ,thecompositions of our invention mayibe diluted as necessary, conveniently by adding sufficient water to give an emulsion or dispersion contain; ing fapp'r oximat'ely 0.5-5% of the methylolamide by weight,'together with an acid or-an acid-generating catalyst, and impregnating the textile material with the resultant emulsion or dispersion and thereafter drying and baking the textile material. If desired, the impregnating and drying may becarfried out at higher temperatures.

According to a further feature of our invention "we provide a process for the productionof water-repellent finishes on textilematerials which comprises applying to thetextilematerials acomposition of our invention, in

conjunction with an acid or an acid-generating catalyst, and thereafter heating the treated textile materials.

The acid catalyst may be for example acetic, lactic, tartaric or citric acid. The acid-generating catalyst may be any substance which develops acidity duringthe final heating stage, for example ammonium salts such' as diammonium hydrogen phosphate,ammonium chloride, ammonium dihydrogen phosphate and ammonium thiocyanate, or metal salts such as aluminium sulphate and zinc nitrate, and the like. The proportion of acid oriacid-gencrating catalyst used maybe between 5% and 20%, preferably about of the weight of the methylolamide.

The textile materials which may be treated by the process of our invention include those made from natural and i regenerated cellulose fibres, and synthetic polyamide and polyester fibres, and may be in the form. of loose fibre, yarn'or piece goods and the like.

j The application of the composition to the textile material may be carried out by impregnating, for example by padding, drying and baking, or by impregnating and high temperature drying, The heating'may be at any temperature above 120 C. which does not harm the textile material, preferably between 140 C. and 160 C. j

The composition of our invention is preferably one contaiuing methylolsteararnide and a salt of a sulphated fatty alcohol, for example sodium oleyl/cetyl sulphate. The quantity of composition to be used should be such as to provide between 0.5% and 10%, preferably 0.5% to 5% by weight of the methylolamide and the dry fabric.

The invention is illustrated but not limited by the following examples in which the parts and percentages are by weight:

, EXAMPLE 1 A mixture of 500 parts of stearamide, (a commercial grade, containing 7% of stearic acid), 60.5 parts of paraformaldehyde and 1820 parts of toluene is heated at a temperature between 70 and'75" C. for 8 hours and is then cooled, with stirring, to room temperature. The suspension of methylolstearamide so formed is then filmud and the solid is washed twice with portions, each of 170 parts, of toluene. The solid is then dried, and ground through a 60 mesh sieve in a heater mill, whereby 470 parts of methylolstearamide are obtained as a white powder, melting point 1 09-111 C., containing 1.5 of free stearic acid as determined by titration of a weighed sample of the product dissolved in warm ethanol with a standard solution of sodium hydroxide, using phenolphthalein as indicator.

To 350 parts of the methylolstearamide prepared as described above is added a'solution of 46.5 parts of a 30% aqueous paste of sodium oleyl/cetyl sulphate in 117 parts of water at 65 C. The mass is mixed for 4 hours, and then 52.5 parts of isopropanol are added. A further 309 parts of water are then added during 1 hour, while mixing is continued. The product comprises 870 parts of a methylolstearamide dispersion containing of methylolstearamide, in the form of a pourable, creamy fluid.

EXAMPLE 2 465 parts of methylolstearamide prepared as described in Example 1 are added during 1% hours, with stirring, to a solution of 58.1 parts of sodium cetyl/oleyl sulphate in 1782 parts of water at 40 C. The mixture is stirred for 20 minutes more, and is then allowed to stand for 30 minutes. The mixture is then gravel-milled for 24 hours. The product is separated from the gravel, and comprises 2150 par-ts of a fluid dispersion containing 20% of methwater is heated to 98-100 C. and agitated rapidly at this temperature for 10 minutes. The mixture is cooled with agitation over V. hour to -83 C. and then a concentrated aqueous solution containing 0.2 part of sodium hydroxide is added. Agitation is maintained at 80-83 C. for 2 hours, and the mixture is cooled to room temperature with agitation over 6 hours. The pH of the mixture is then adjusted to about 7.5 by addition of hydrochloric acid. The product comprises 333 parts of a creamy paste containing about 33% of methylolstearamide.

The steara'mide used in Examples .1, 2 and 3 is a commercial grade containing'about equal parts of stearamide and palmitarnide. f g

' EXAMPLE 4 matures 500. of stea'ramide (a technical quality containing about 6% -ofstearic .acid and with a C 5 C fatty chain length ratio of 1:9), 59.2 partsof paraforrnaldehyde, andi-l820iparts of toluene is stirred at a temperature of 75 to 80 C. for 8 hours and then cooled with stirring to r'oom temperature. The suspended methylolstearamide is filtered and the solid washed with 170 parts of toluene and dried. It is then ground through a 60 mesh sieve in a beater mill, whereby 465 parts of methylolstearamide are obtained as a whitepowder, 111.

A mixture of 630 parts of myristamide (technical quality, containing 6.0% of mystic acid), 100,parts of paraformaldehyde and 1800 parts of toluene is stirred at a temperature between 70 and 75 C. for 8 hours and is then cooled with stirring to room temperature. The suspension of methylohnyristamide so formed is then filtered and the solid is washed with toluene in three separate portions each of parts. The solid is then dried and ground through a 60 mesh sieve in a heater mill, whereby 532 parts of methylolmyristamide are obtained as a white powder, melting point 116-118 C., containing 0.5% of myristic acid.

A mixture of 50 parts of the methylolmyn'stamide prepared as described above, 6.8 parts of a 30% aqueous paste of sodium oleyl/cetyl sulphate and 193 parts of water is gravel milled for 36 hours. The product is separated from the gravel and comprises 242 parts of a fluid dispersion containing 20%of methylolmyristamide.

EXAMPLE 6 A cotton gaberdine fabric is immersed in an aqueous dispersion containing 7.5 parts of the dispersion prepared as described in Example 1, 0.3 part of diammonium hydrogen phosphate and 92.2 parts of water. The fabric is squeezed until the amount of dispersion retained is 50% of the weight of the, dry fabric, and is dried at 60-100 C. and then heated for 4 minutes at C; The fabric thus treated possesses a high degree of water repellency which has good durability to washing and dry-cleaning treatments.

EXAMPLE 7 Pieces of a cotton gaberdine fabric are treated with aqueous dispersions of methylolstearamide according to the method described in Example 6', the dispersions being made by the method described in Example 1 from samples of methylol stearamide having stearic acid contents ranging from 1.5% to 10.0%. The water-repellencies of the pieces of treated fabric, measured before and after washing, show that an increase in stearic content of the methylol stearamide does not impair the water repellency of the treated fabric before washing, but that there is a decrease in water-repellency after washing. Water-repellency test results illustrating these effects are tabulated below:

Water-repellency results obtained by the spray rating method Initial Water Re- Percentage Stearic Acid content of methylol Water pellency stearamide Repelafter lency washing EXAMPLE 8 EXAMPLE 9 A cotton poplin fabric is immersed in an aqueous dispersion containing 7.5 parts of the dispersion prepared as described in Example 1, 2 parts of a melamine-formaldehyde condensate containing 90% solids, 0.3 part diammonium hydrogen phosphate and 92.7 parts of water.

, The fabric is squeezed until the amount of dispersion retained by the fabric is 70% of the weight of dry fabric,

and is then dried at 60-100 C. and finally is heated for 4 minutes at 150 C. The fabric thus treated possesses a high degree of water repellency and which has good durability to Washing and dry-cleaning treatments.

EXAMPLE 10 Pieces of cotton gaberdine fabric are treated with aqueous dispersions of methylol stearamide according to the methods described in Examples 8 and 9, the dispersions being made by the method described in Example 1 from samples of methylol stearamide having stearic acid contents ranging from 1.5% to 4.1%. The Water repellencies of the pieces of treated fabric measured before and water washing show that an increase in the stearic acid content of the methylol stearamide causes a decrease in water-repellency after washing when no melamine resin is present, and a decrease in initial repellency when melamine resin is present. Water repellency test results illustrating these effects are tabulated below:

Water-repellency results obtained by the Bundesinann test method.

In the above table A=percent water absorbed by fabric during test, P=water passed through fabric during test measured in millilitres.

EXAMPLE 11 A cotton gaberdine is immersed inan aqueous dispersion containing 15 parts of the dispersion prepared as described in Example 2, 3 parts of a urea-formaldehyde syrup with a solids content of 0.3 part diammonium hydrogen phosphate and 85.2 parts water. The fabric is squeezed until the amount of dispersion retained by the fabric is 50% of the weight of the dry fabric and is then dried at 60100 C. and finally is heated for 4 minutes at 150 C. The fabric thus treated possesses a high degree of water repellency which has good durability to washing and dry cleaning treatments.

EXAMPLE 12 A viscose gaberdine is immersed in an aqueous dispersion containing 6 parts of the dispersion prepared as described in Example 1, 0.24 part ammonium dihydrogen phosphate and 93.76 parts of water. The fabric is squeezed until the amount of dispersion contained is 70% of the weight of the dry fabric and is then dried at 60100 C. and is finally heated for 4 minutes at 150 C. The fabric thus treated possesses a high degree of water repellency which has good durability to washing and dry cleaning.

What we claim is:

1. An aqueous composition useful for the production of water-repellent finishes on textile materials consisting essentially of a methylolamide of a fatty acid containing at least 14 carbon atoms in the molecule, less than 4.0% by weight of free fatty acids by weight of the said methylolamide, and an anionic surface active agent as dispersing agent in the proportion of not more than 6% by weight of the methylolamide.

2. A composition, according to claim 1, containing less than 2.0% by weight of free fatty acids by weight of the said methylolamide.

3. A composition according to claim 1 wherein the composition contains at least 20% of methylolamide and the anionic surface active agent is sodium oleyl/cetyl sulphate.

4. A composition according to claim 3 wherein the methylolamide is derived from a commercial stearamide which contains approximately equal parts of stearamide and palmitamide.

5. A textile material rendered water-repellent with a composition consisting essentially of a methylolamide of a fatty acid having at least 14 carbon atoms in the molecule, said composition also containing less than 4.0% by weight of free fatty acids based on the weight of said methylolamide and an anionic surface active agent as dispersing agent in the proportion of not more than 6% by weight of the methylolamide.

6. A process for the production of water-repellent finishes on textile materials which comprises applying to the textile materials a composition according to claim 1 in conjunction with a member of the group consisting of an acid and an acid generating catalyst, and thereafter heating the treated textile materials.

7. A process according to claim 6 wherein the methylolamide of the composition contains less than 2.5% by weight of stearic acid and the composition is applied to textile materials together with a resin precondensate.

8. A process according to claim 6 wherein the textile material is heated at a temperature above C.

References Cited in the file of this patent UNITED STATES PATENTS 2,393,202 Stegemeyer Jan. 15, 1946 2,491,249 Cathers et a1. Dec. 13, 1949 2,526,638 Ceepery Oct. 29, 1950 2,693,460 Gagliardi Nov. 2, 1954 2,676,936 Schofield Apr. 27, 1954 2,763,649 Albrecht Sept. 18, 1956 2,828,222 Kine et al. Mar. 25, 1958 2,861,054 Rust et a1. Nov. 18, 1958

Claims (2)

1. AN AQUEOUS COMPOSITION USEFUL FOR THE PRODUCTION OF WATER-REPELLENT FINISHES ON TEXTILE MATERIALS CONSISTING ESSENTIALLY OF A METHYLOLAMIDE OF A FATTY ACID CONTAINING AT LEAST 14 CARBON ATOMS IN THE MOLECULE, LESS THAN 4.0% BY WEIGHT OF FREE FATTY ACIDS BY WEIGHT OF THE SAID METHYLOLAMIDE, AND AN ANIONIC SURFACE ACTIVE AGENT AS DISPERSING AGENT IN THE PROPORTION OF NOT MORE THAN 6% BY WEIGHT OF THE METHYLOLAMIDE.

6. A PROCESS FOR THE PRODUCTION OF WATER-REPELLENT FINISHES ON TEXTILE MATERIALS WHICH COMPRISES APPLYING TO THE TEXTILE MATERIALS A COMPOSITION ACCORDING TO CLAIM 1 IN CONJUNCTION WITH A MEMBER OF THE GROUP CONSISTING OF AN ACID AND AN ACID GENERATING CATALYST, AND THEREAFTER HEATING THE TREATED TEXTILE MATERIALS.