US2887408A - Method of treating textile materials - Google Patents

Description

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METHOD OF TREATHY G TEXTILE MATERIALS William Julius Van Loo, In, Middlesex, N.J., assignor to American Cyanamid Company, New York, N.Y., a corporation of Maine Continuation of application Serial No. 621,014, November 8, 1956. This application September 27, 1957, SerialNo. 686,557

11 Claims. (Cl. 117-1383) The present invention relates to the treatment of textile materials and in particular to the treatment of textile materials containing a major portion of nitrogen-containing synthetic thermoplastic hydrophobic materials, as for example, the nylons, acrylic fibers, and the like with certain stable thio compound formaldehyde reaction products. v This application is a continuation of application Serial No. 621,014, filed November 8, 1956, and now abandoned.

More particularly, the present invention relates to a process for imparting a stiff, springy hand to such textile materials without increasing their flammability.

Heretofore, in order to impart a stiff, Jspringy hand without increasing the flammability of textile materials of the type specified, various sulfonated ureaiormaldehyde resins, sulfonated urea-thiourea-formaldehyde resinous reaction products and the like have been employed. Ditficulty has been encountered with regard to the stability of these materials and in many instances it has been found that stability for periods of time of the order of two Weeks have been optimum. In addition, pad bath stability in many instances was poor. Under such "circumstances, resins of these types were greatly limited in their use.

Within limits, these problems were overcome by certain unique and inventive processes, whereby employing certain rather narrow conditions and quantities of reactants, resinous materials were produced which overcame the deficiency of stability recognized as a property of earlier similar resins. These resins, however, presented certain deficiencies of their own. Included among them is the problem of carefully maintaining the rather narrow conditions of the processes employed for the production of such resins, so as to maintain their water-soluble or hydrophilic characteristics and at the same time render them essentially stable or at least stable for such periods of time as would not significantly reduce their general utility. In addition, pad bath stability with these improved resins is only fair by normal standards.

Accordingly, it is an object of the present invention to provide a process for treating nitrogen-containing synthetic thermoplastic hydrophobic materials with a particular type of reaction product, whereby the materials so treated have an acceptably stiff, springy hand, and in addition are not more flammable than corresponding untreated samples.

, More particularly, it is an object of the present invention to provide a process whereby nylon-containing textile materials may be treated with the formaldehyde reaction products of certain thio compounds, which reaction products are at least partially water soluble, and preferably substantially water soluble, stable, and easilymanufac tured by known processes, to impart a stiff hand to the nylon-containing textile material without increasing its combustibility.

These and other objects and advantages are accomplished by a process for treating textile materials contain ing a major portion of a nitrogen containing synthetic thermoplastic hydrophobic material which comprises treating said material with an essentially aqueous medium 2,887,408 Patented, May 19, 1 959 ice StCHM nZ wherein n is from 0 to 4, and an acid acting catalyst, and thereafter curing said formaldehyde reaction product to a water-insoluble state.

Compounds included within the generic formula set forth hereinabove include specifically the following: thiobis(formamide), thiobis(acetamide), thiobis(propionamide), thiobis(butyramide) and thiobis(valer:amide).

The stable, at least partially water-soluble, formaldehyde reaction products of these compounds may readily be applied from an aqueous solution so as to impart to the fabric from about 10 to about resin solids and preferably from about 15% to about 60% resin solids based on the dry weight of said fabric.

They may be applied by any of the conventional means, as for example, by spraying, dipping, immersion, or the most commonly employed padding technique. Thereafter, preferably the fabric is run through a microset padder or other similar operating device whereby the Wet pick-up of the fabric is adjusted as desired.

In applying the formaldehyde reaction products of the present invention, a suitable acid acting catalyst is employed to provide the necessary rapid cure. Among the acid and acid acting type curing catalysts are the ammonium salts, like ammonium chloride, amine salts, like triethylamine hydrochloride, alkanolamine salts, like triethanolamine hydrochloride, metallic salts, such as magnesium chloride, zinc chloride, zinc nitrate and the like, and certain free acid catalystssuch as, for example, acetic acid, adipic acid, oxalic acid, tartaric acid, and the like. Witlrrespect to the salt catalysts, these are usually emp oyed in amounts of from between 1 and 60% based on the Weight of resin solids, and preferably employed in amounts of from between 2 and 25%, based on the amount of resin solids. With respect to the free acid type catalysts, these are generally employed in amounts sufficient to provide an application bath pH of the order of between 1 and about 3.5. These free acid catalysts readily permit a low temperature simultaneous dry and cure operation without adversely affecting the tensile strength of the textile fabric.

The drying and curing of a treated fabric may be accomplished in separate steps or in a single operation, if this is preferred. When drying is carried out as a separate step, it may be done at temperatures ranging from about 200 F. to 250 F. for from about 3 minutes to about 1 /2 minutes, respectively. Generally speaking, the length of time required is inversely proportionalto the temperahire at which drying and/or curing is effected. Thus, somewhat longer periods of time .would be required when lower temperatures are employed and shorter periods of time would be required where higher temperatures are employed. The preferred temperature and time ranges for curing of'a dried fabric are from about 4 minutes at 275 F. to about 30 seconds at 450 F. When drying and curing are carried out in a single step, operation times of from between about 15 minutesat 250 F. to about 3 minutes at 350 F. have been found to be satisfactory.

As noted hereinabove, the present process is limited to die treatment of textile fabrics comprised of nitrogencontaining thermoplastic hydrophobic polymeric materials, important examples of which are thermoplastic polyamides and acrylic fibers; With respect to the former, the nylons are the important class: and with respect to the latter, acrylics, such as are-known commercially as Or-lon, Acrilan, and the like, are intended to be included.

While the present invention is particularly adapted and effective where the textile material being so treated is composed entirely of nitrogen-containing thermoplastic hydrophobic. polymeric materials, it is contemplated that the present process is fully applicable to textile materials where the synthetic portion of it is found in a major portion, that is, in an amount in excess of 50% thereof.

In order that the present invention may be more fully understood, the following examples are given primarily by way of illustration. No specific details therein should be construed as limitations except as they appear in the appended claims. All parts and percentages are by weight unless otherwise designated.

EXAMPLE 1 1.5-ounce nylon twill was padded through a pad bath solution containing 65.45 parts of water, 1.25 parts ofammonium chloride, and 33.3 parts of a commercial fire retardant finish for nylon which is 75% solids and contains a mixture of partially methylated thioureaformaldehyde and partially polymerized urea-formaldehyde resin.

The treated fabric was then run through a microset pneumatic padder. The treated nylon fabric contained 20% resin solids, based on the dry weight of the fabric. Thereafter, the treated fabric was dried and cured in a single operation for 6 minutes at 290 F. and thereafter hand evaluation and fire retardance was determined.

The results obtained are recordedin Table I.

Fire retardance was determined; by a so-called cigar roll test in which a portion of thetreated fabric is rolled into a cylinder and ignited with a match. Observations are made of the difficulty or ease of ignition of the treated fabric, rate of burning, and continued burning when the match is removed, in comparison to the performance of an untreated fabric tested in a similar manner. The untreated fabric is not readily ignited, burns slowly when ignited, and does not continue to burn when the match is removed. The overall performance of the treated fabric was then rated in comparison to the performance of the untreated fabric.

Hand evaluations are rendered by an operator, who compares the hand for relative stiffness of a fabric treated according to the present process and fabrics treated with other known commercial flame-retardant compositions, as well as an untreated fabric. The evaluations are recorded in terms of softness or stiffness, as compared to an untreated 1.5-ounce nylon twill sample, as will be apparent in Table I set forth hereinbelow.

EXAMPLE 2 This application was carried out in a manner similar to that described in Example 1, except that the treating solution contained 69.25 parts of water, 1.25 parts of ammonium chloride, and 29.5 parts of a partial polymer of dimethylol urea containing 85% solids. The treated nylon fabric contained 20% resin solids based on the dry weight of the fabric.

The results obtained are recorded in Table I.

EXAMPLE 3 This application was carried out in a manner similar to that described in Example 3 and on similar fabric, except that the treating solution contained 77.6 parts of water, 2.4 parts of magnesium chloride, and 20 parts of the dimethylol derivative of thiobis(acetamide) imparting 20% resin solids to the fabric.

The results obtained are evaluated hereinbelow in Table I.

EXAMPLE 5 This application was carried out in a manner similar to that described in Example 3 and on similar fabric, except that the treating solution contained 78.8. parts of water, "1.2 parts of 2-amino-2-methyl-propan0l-l-hydrochloride, and 20 parts of the dimethylol derivative of thiobis(valeramide), imparting 20% resin solids to the fabric.

The results obtained are evaluated hereinbelow in Table I. EXAMPLE 6 Medium weight plain weave fabric of acrylic fibers commercially known as Orlon was treated in a manner similar to that described in Example 3, except that the treating solution contained 78.8 parts of water, 1.2 parts of triethylamine hydrochloride, and 20 parts of the dimethylol derivative of thiobis(propionamide), imparting 20% resin solids to the fabric.

The results obtained are evaluated hereinbelow in Table I.

EXAMPLE 7 This application was carried out in a manner similar to that described in Example 6, and on the same type fabric, except'thatthe treating-solution contained 79 parts of water, 1 part'of oxalic acid, and20 parts of thedimethylol derivative of thiobis(propionamide). The bath pH was 2.6 and 20% resin solids were imparted to the fabric.

This application was carried out in a manner-similar to that described in Example 3 and on similar fabric, except that the treating solution contained 397.0 parts of water, 3.0 parts of ammonium sulfate, and 200 parts of the dimethylol derivative of thiobis(propionamide) containing 30% solids. This treatment resulted in an application of 10% resin solids based on the weight of the fabric.

The results obtained with respect to hand and fire retardancy when compared with the untreated fabric, both before and after washing, are summarized in Table II, set forth hereinbelow. The wash reported therein was for 10 minutes in a 0.1% neutral soap at 100 F. in an agitator washer, followed by rinsing in water at 100 F. and drying in a circulating hot air oven for 15 minutes at 225 F.

Table II Test Example8 Untreated 1 m 1 it n a Stl S i. Washed S S fii.

FireIRfiitaii-dance:

n a E al..-.. St d W h Egii l st iid i As the above examples clearly point out, the application'of the formaldehyde reaction products ofthio compounds 'of this invention results in substantially stiffening the hand of the treated fabric without increasing its flammability or combustibility, and further that this treatment is durable. The impartation of this property to nitrogencontaining synthetic fiber-containing textile materials is of the greatest importance in certain of the applications where a stiff fabric is highly desirable commercially. Thus, for example, fabrics ,of the type referred to herein and more specifically nylon, find considerable usage in ladies evening wear, such as net wraps, petticoats, and the like.

While stiffness may be imparted to nylon fabrics and garments of the class described by the application thereto of conventional thermosetting resins, as for example, certain aminoplast resins, such as urea-formaldehyde, includ ing the cyclic ureas such as ethylene urea, 1,2-propylene urea, 1,3-propylene urea and the guanamines and melamine-formaldehyde reaction products, including the alkylated derivatives of these species, the resultant fabric is found to be more highly flammable than the untreated. (See Example 2, Table 1.) However, it should be noted that these and other conventional aminoplast resins may be employed in combination with the formaldehyde reaction products of the compounds of the present invention, so long as the quantities used do not increase the flammability of treated material.

While the fabrics treated with the resinous materials of the present invention are classifiable as non-flammable, nettings treated with conventional aminoplast resins are classifiable as those subject to rapid and intense burning, within the meaning of Public Law No. 88--83rd Congress, The Flammable Fabrics Act.

The thio compounds which are reacted with formaldehyde according to the present invention are a preferred group of thio compounds, because of the high degree of water solubility which they possess and their excellent stability in storage or in pad bath over reasonably long periods of time. This is in sharp distinction over conventional stiffening so-called flame retardant finishes referred to hereinabove. The formaldehyde reaction products of these compounds may be prepared according to conventional methylolation processes, which are well known to those skilled in the art.

Thus, for example, a suitable thio compound contemplated by the present invention and formaldehyde or formaldehyde engendering material may be co-reacted on the alkaline side in mole ratios of from 1:2-4 or more, respectively, until the solution clears and the suitable methylol compound is formed. Preferably, these formaldehyde reaction products are essentially monomeric in characteristic in that as such their hydrophilic or watersoluble characteristics and stability are enhanced. However, partial polymeric materials, that is, materials which have not become hydrophobic or become Water insoluble, and which possess some water solubility, are contemplated.

In the preferred water-soluble essentially monomeric form, these thio compounds should have from between 1 and 2 moles of combined formaldehyde. Usually, when the amount of combined formaldehyde is of the order of 1.7, 1.8 or greater, the material is referred to as a dimethylol compound or dimethylol derivative.

While no particular advantage has been observed when the dimethylol derivatives of the present invention are alkylated or etherified, in certain instances this may be desirable, particularly where the dimethylol derivative is partially polymerized when applied, or when the thiobisdiamide is either butyramide or valeramide. In so doing, they may be alkylated with saturated aliphatic alcohols containing from 1 to 4 carbon atoms and preferably 1 and 2 carbon atoms so as to fully alkylate the methylol groups attached thereto or partially alkylate these groups. This may be done by reacting 1 mole of dimethylol derivative with from 2 to emoles ofa'satuihted aliphatic alcohol containing :from Ito 4 carbon atoms on the acid side, in accordance with procedures well-known to those skilled in the art. It should be noted that by theterm formaldehyde reaction product as the term is used herein that both methylol and alkylated methylol compounds are contemplated.

If the alkylated derivative is preferred, it is employed in the present process in a manner similar to 'tliafdescribed hereinabove.

I claim:

1. A process for treating textile materials containing a major portion of nitrogen-containing synthetic thermoplastic hydrophobic material, which comprises treating said material with an essentially aqueous medium comprising an at least partially water-soluble formaldehyde reaction product of a compound havingthe following general formula:

wherein n is from O to 4 and an acid acting catalyst, and thereafter curing said formaldehyde reaction product to a water-insoluble state.

2. A process for treating textile materials containing a major portion of a thermoplastic polyamide, which comprises treating said material with an essentially aqueous medium comprising an at least partially water-soluble formaldehyde reaction product of a compound having the following general formula:

wherein n is from O to 4 and an acid acting catalyst, and thereafter curing said formaldehyde reaction product to a water-insoluble state.

3. A process for treating textile materials containing a major portion of nylon, which comprises treating said material with an essentially aqueous medium comprising an at least partially water-soluble formaldehyde reaction product of a compound having the following general formula:

SlCH cONH l wherein n is from 0 to 4 and an acid acting catalyst, and thereafter curing said formaldehyde reaction product to a water-insoluble state.

4. A process according to claim 3 wherein the formaldehyde reaction product is essentially monomeric.

5. A process according to claim 3 wherein the compound is thiobis (formamide) 6. A process according to claim 3 wherein the compound is thiobis(acetamide).

7. A process according to claim 3 wherein the com pound is thiobis (propionamide).

8. A process according to claim 3 wherein the compound is thiobis(butyramide).

9. A process for treating textile materials containing a major portion of nylon, which comprises treating said material with an essentially aqueous medium comprising a water-soluble, essentially monomeric formaldehyde reaction product of a compound having the following general formula:

wherein n is from 0 to 4 and an acid acting curing catalyst in an amount sufiicient to apply from between 15 and 60% resin solids on the nylon, based on the weight of said material, and thereafter curing said formaldehyde reaction product to a water-insoluble state.

10. A textile material containing a major portion of nylon, which is impregnated with from 15 to 60% of a heat-cured formaldehyde reaction product of a compound having the following general formula:

8 ECH CONH J 3 wherein n is from 0 to 4.

sesame 2499986 Dickey et a1 May 7, 1940 8 v Hurwitz et a1 Oct. 7, 1952 I-Iurwit'z et a1; Oct. 7, 1952 Reibnitz et a1 Jan. 17, 1956 FOREIGN PATENTS Canada Aug. 22, 1950

Claims (1)

1. 3. A PROCESS FOR TREATING TEXTILE MATERIALS CONTAINING A MAJOR PORTION OF NYLON, WHICH COMPRISES TREATING SAID MATERIAL WITH AN ESSENTIALLY AQUEOUS MEDIUM COMPRISING AN AT LEAST PARTIALLY WATER-SOLUBLE FORMALDEHYDE REACTION PRODUCT OF A COMPOUND HAVING THE FOLLOWING GENERAL FORMULA: