US3390009A - Process for rendering hydrophobic fibers containing textile antistatic and the treating composition - Google Patents

Description

United States Patent 3,390,009 PROCESS FOR RENDERING HYDROPHOEIC FI- BERS CONTAINING TEXTILE ANTISTATIC AND THE TREATING COMPOSITION Emery I. Valko, Belmont, Mass., assignor to Standard Chemical Products, Inc., Hoboken, N.J., a corporation of New Jersey No Drawing. Filed Aug. 21, 1964, Ser. No. 391,283 2 laims. (Cl. 117-1395) ABSTRACT OF THE DISCLOSURE This invention relates to a process for rendering synthetic fibers antistatic, which comprises impregnating textile materials containing a substantial portion of hydrophobic fibers, to give a total dry weight add-on of between O.4% and 8% by weight, based on the weight of said textile material, with an aqueous acidic solution of a mixture of Z-carbamoylethyl derivatives of polyoxyethylene amines and their N-methylol derivatives, with a polyethylene glycol and an acidic catalyst, removing the water from said impregnated textile material and heating said dried impregnated textile material to cure the impregnating mixture. The invention also relates to the impregnating compositions.

Textile materials (fibers, filaments, yarns, fabrics and the like) based on synthetic polymers, such as polyamides, polyesters, acrylics, modacrylics, polyolefins and the like, exhibit a tendency to accumulate electrostatic charges when processed or used under ordinary conditions. In order to reduce this bothersome tendency which causes difiicuties in processing and is objectionable in use, processes have been proposed to coat the fiber surface with a suitable polymeric material insolubilized with the aid of alkaline catalysts. Most of these prior art processes have serious shortcomings such as high cost, discoloration during the high temperature exposure required for the insolubilization, the necessity of removing the catalyst by afterwash, and incompatibility with other desirable finishing agents.

It is, therefore, an object of this invention to provide a process and composition for treating textile materials for rendering them antistatic.

A further object is to provide an antistatic textile composition which is relatively inexpensive and does not discolor under conditions of textile processing.

Another object is to provide an antistatic textile composition which is compatible with other conventional textile treating agents and requires no afterwash.

These and other objects of my invention will become apparent as the description thereof proceeds.

The present invention makes it possible to avoid these shortcomings of the prior art and to provide durable antistatic finishes for synthetic textile materials with the aid of acidic or acidic-acting catalysts. For this purpose compounds are applied containing at least two carbamoylethyl groups attached to basic nitrogen atoms in admixture with aldehydes, preferably formaldehyde, together with the catalyst.

The carbamoylethyl compounds can be represented by the general formulas in which R represents a monovalent organic radical, R and R represent monovalent organic radicals or hydrogen atoms and R, a bivalent organic radical. The organic radicals may contain additional carbamoylethyl groups attached to basic nitrogen atoms. Particularly efiicient are compounds having a polyoxyethylene chain in the organic radicals. Such a polyoxyethylene chain has the formula (C'I-I CH O) wherein n represents a number between 3 and These carbamoylethyl compounds are conveniently prepared by the addition of acrylamide to primary and secondary amines of the general formula 1 HN\ and IITH-Ra-NH Formula III Formula IV wherein R R R and R represent the same groups as in the above Formulas I and II.

The preferred aldehyde is formaldehyde and the preferred catalysts are magnesium chloride, zinc nitrate, Zinc chloride and alkanolamine hydrochlorides.

Instead of applying formaldehyde and the carbamoylethyl compound as separate compounds they can be precondensed to form methylol compounds and applied in this form with a catalyst to be condensed by a curing process, that is, by exposure to high temperature, to insoluble methylene compounds.

Since the amide group of the carbamoyl group contains two replaceable hydrogen atoms, each carbamoyl group can add two aldehyde molecules or groups. It is, however, advantageous to use only one aldehyde group per carbamoyl group. If such a ratio is used and the carbamoylethyl compounds contain only two carbamoylethyl groups in the molecule, the curing results in the formation of a linear polymer. Such a polymer is in general soluble either in water or in organic solvents or in both. A finish consisting of such linear polymer would have, in general, low resistance to water and solvents, and therefore poor fastness to laundering and dry cleaning. In order to improve the fastness properties, it is necessary to produce crosslinked polymers. This is achieved by using compounds containing more than two carbamoylethyl groups in the molecule. In accordance with the laws of polymer science, it is possible to achieve these results also by using mixture of compounds containing two carbamoylethyl groups and compounds containing three or more carbamoylethyl groups. In such mixture the molar ratio of the compounds containing only two carbamoylethyl groups must be kept under a certain limit depending how many carbamoylethyl groups are present in the other compounds used. Another method to achieve crosslinking is by use of dialdehyde or polyaldehyde instead of formaldehyde, i.e. glyoxal or glutaraldehyde. Most of the carbamoylethyl compounds and their methylol derivatives are water soluble either in form of the free bases or in form of their salts. Such salts are easily produced by neutralizing the free amine groups with such organic acids as formic, acetic, lactic, glycolic acids or inorganic acids such as hydrochloric or nitric acid.

The textile materials are provided with the required finish in three steps: (1) impregnation with an aqueous solution containing the reactants and the catalyst, (2) removal of the solvent water and (3) heat-curing. The impregnation can be accomplished by padding followed by squeezing. The removal of water can be accomplished by evaporation at elevated temperature. The curing can be done by exposure to a temperature of 100 C. to 200 C. The exposure time varies between a few seconds and a few minutes. The conventional time-temperature relation prevails: the higher the temperature, the shorter is the time required to complete the condensation leading to the formation of the insoluble polymer.

I found that in order to obtain an efiicient antistatic finish, the polymer should preferably contain a chain of oxyethylene (OCH- CH groups. There are several ways to introduce these groups. For example, as mentioned above, a polyoxyethylene compound containing one or two amino groups can be used as the primary or secondary amine of Formulas III and IV. Such a compound is commercially available under the trade name Polyetherdiamine from the Union Carbide Corporation. Polyglycols containing reactive chlorine such as obtained by reaction of polyglycols with thionylchloride or by addition of epichlorohydrin in presence of a suitable catalyst to polyglycols, can be reacted with excess of polyamines such as ethylene diamine or diethylenetriamine to obtain mixtures of primary and secondary amines containing suitable polyoxyethylene chains in the molecule. Furthermore, such compounds can also be obtained by reacting mixtures of polyglycols and compounds of Formulas I and II with formaldehyde or with other reactive aldehydes. This reaction can be carried out concurrently with the heat curing process.

The amount of finish required to obtain varies with the nature of the textile material and with the degree of antistatic protection desired. For most purposes a total add-n between 0.4 percent and 8 percent by weight on the weight of the textile appears a suitable amount.

The following specific examples are presented to illustrate the invention and to enable persons skilled in the art to better understand and practice the invention and are not intended to be limitative.

EXAMPLE I A. Preparation of carbamoylethyl compounds For the preparation of tris(2-carbamoylethyl)amine (Compound I) 24.08 grams (0.34 mole) of acrylamide were dissolved in 50 grams distilled water. To this solution were added 50 grams of 28% NH OH (0.825 mole NH;.,) and the reaction mixture was left standing at room temperature overnight. After evaporation of the water at 20 mm. Hg and 65 C., the solution became very viscous.

Upon cooling, the mixture solidified to a white crystal. 25.70 grams of tris(2-carbamoylethyl)amine (98%) were obtained. Titration for the presence of double bond indicated that the reaction had proceeded to over 98% completion.

EXAMPLE II For the preparation of tris(N-methylol-Z-carbamoylethyl)amine (Compound II) 13.60 grams (0.0592 mole) of tris(2-carbamoylethyl)amine were dissolved in 26 grams distilled water and 14.4 grams 'of 37% formaldehyde solution were mixed with the solution. The solution was left standing at room temperature overnight. This ratio of reagents gave 3 moles HCHO for each mole of amine. The solution was 35% active of tris(N-methylol-2- carbamoylethyl) amine.

EXAMPLE III For the preparation of tetra(2-carbamoylethyl)ethylene diamine (Compound III) 6.540 grams (0.1 mole) of 92% ethylene diamine were dissolved in 100 ml. CH OH.

To this solution were added 28.40 grams (0.4 mole) of acrylamide. The reaction mixture was left standing at room temperature for three days. The product was a white crystal adhering to the bottom of the flask. After recrystallization with acetone, the product was dried under vacuum for 2 hours. Yield of the reaction was 25.50 grams Analysis for the presence of double bond indicated the reaction had proceeded over 98% to completion.

EXAMPLE IV For the preparation of tetra(N methylol-Z-carbamoylethyl)ethylene diamine (Compound IV) 8.80 grams (0.0256 mole) of tetra(2-carboylethyl)ethylene diamine were dissolved in 50 grams distilled water. T 0 this solution were added 8.32 grams of 37% formaldehyde solution. This ratio of reagents gave 4 mole HCHO per mole of amine. The solution was left standing at room temperature overnight. The solution was 20.8% active of tetra- (N-methylol-2-carhamoylethyl)ethylene diamine.

EXAMPLE V For the preparation of tetra(2-carba-moylethyl)1,3 diamino propane (Compound V) 7.413 grams (0.10 mole) of 1,3 diamino propane were dissolved in 100 ml. CH OH. To this solution were added 28.4 grams (0.40 mole) of acrylamide. The reaction mixture was left standing at room temperature for three days. The solvent was evaporated under vacuum at room temperature. The product was a white solid which was dried under vacuum for 2 hours. Analysis for the presence of double bond indicated the addition reaction had completed over 98%.

EXAMPLE VI For the preparation of tetra(N-rnethylol-Z-carbamoylethyl)l,3 diamino propane (Compound VI) 6.45 grams (0.018 mole) of tetra(2-carbamoylethyl)1,3 diamino propane were dissolved in 50 grams distilled water. To this solution were added 5.85 grams of 37% HCHO solution. The solution mixture was left standing at room temperature overnight. The ratio of reagents gave 4.0 mole HCHO per mole of amine. The solution was 13.5% active of tetra(N-methylol-Z-carbamoylethyl)1,3 diamino propane.

EXAMPLE VII For the preparation of penta(Z-carbamoylethyl) imino bis propylamine (Compound VII) 13.123 grams (0.10 mole) of imino-bis-propylamine were dissolved in 100 ml. CH OH. To this slightly exothermic mixture were added slowly 35.5 grams (0.5 mole) of acrylamide. The reaction mixture was left standing at room temperature for three days. After evaporation of the CH OH under vacuum at room temperature, the product was viscous pale yellow liquid. Titration of the double bond indicated the reaction had proceeded over 98%.

EXAMPLE VIII For the preparation of penta(N-methylol-Z-carbamoylethyl)imino bis propylamine (Compound VIII) 38.88 grams (0.08 mole) of penta(Z-carbamoylethyl)imino bis propylamine were placed into 32.5 grams of 37% HCHO solution. The high viscosity of penta(2-carbamoylethyl) imino bis propylamine delayed the formation of a homogenous solution upon stirring. The mixture became homogenous after 3 days. The product was 66.5% active of penta(N-methylol 2 carbamolyethyl)imino bis propylamine.

EXAMPLE IX For the preparation of penta(Z-carbamoylethyl)bis hexamethylenetriarnine (Compound IX) 43.0 grams (0.2 mole) of bis hexamethylenetriamine were dissolved in 250 ml. CH OH with some stirring. To this solution were added 71.0 grams (1.0 mole) of acrylamine. Again some stirring was required to form a homogenous solution. The reaction mixture was left standing over a week. After the solvent was stripped off under vacuum at room temperature, analysis of the presence of double bond indicated over 98% of addition had completed.

EXAMPLE X For the preparation of penta(N-methylol-Z-carbamoylethyl)bis hexamethylene triamine (Compound X) 57.04 grams (0.1 mole) of penta(2-carbamoylethyl)bis hexamethylenetriamine were dissolved in 40.5 grams of 37% HCHO solution. Only after three days the solution became homogenous. The product was 73.6% active of penta(N-methylol 2 carbamoylethyl)bis hexamethylene triamine.

EXAMPLE XI For the preparation of tetra(2-carbamoylethyl)1,4- cyclohexane bis(methylamine) (Compound XI) 14.2 grams (0.10 mole) of 1,4 cyclohexane bis(methylamine) were dissolved in 100 ml. CH OH. The reaction mixture was left standing for three days. The product, after the solvent was driven off under vacuum at room temperature, was not soluble in water.

EXAMPLE XII For the preparation of tetra(N-methylol-2-carbamoylethyl)l,4 cyclohexane bis(methylamine) (Compound XII) 26.92 grams (0.0632 mole) of tetra(2-carbamoylethyl)l,4 cyclohexane bis(methylamine) were dissolved in 100 ml. 0.6 N HCl. To this solution were added 20.5 grams 37 HCHO solution. This ratio of reagents gave 4 moles HCHO per mole of amine. The product was 23.4% active of tetra(N-rnethylol-Z-carbamoylethyl)1,4 cyclohexane bis(methylamine) EXAMPLE XIII For the preparation of tetra(2-carbamoylethy1)polyglycol diamine H221 (Compound XIII) 22.1 grams (0.1 mole) of polyglycol diamine H221 were dissolved in 125 ml. CH OH. To this solution were added slowly 28.4 grams (0.4 mole) of acrylamide. The reaction mixture was left standing for 8 days. Analysis of the presence of double bond indicated over 99% completion of addition had occurred.

EXAMPLE XIV For the preparation of tetra(N-methylol-2-carbamoylethyl)polyglycol diamine H221 (Compound XIV) 25.25 grams (0.05 mole) of tetra(2-carbamoylethy1)polyglycol diamine H221 were dissolved in 32.60 grams of 37% HCHO solution. This ratio of reagents gave 4 moles HCHO per mole of diamine. The product was 65.2% active of tetra(N-methylol-2-carbamoylethyl)polyglycol diamine H221.

EXAMPLE XV For the preparation of tetra(2-carbamoylethyl)polyether diamine L1000 (Compound XV) 100 grams (0.1 mole) of polyether diamine L1000 were dissolved in 200 ml. CH OH. To this solution were added 28.4 grams (0.4 mole) of acrylamide. The reaction mixture was left standing for three days. After the solvent was stripped off under vacuum, analysis of the presence of the double bond indicated 98% reaction had completed.

EXAMPLE XVI For the preparation of tetra(N-methylol-Z-carbamoylethyl)polyether diamine Ll-000 (Compound XVI) 119.5 grams (0.093 mole) of tetra(2-carbamoylethy1)polyether diamine L1000 were mixed with 30.40 grams of 37% HCHO solution. The ratio of reagents gave 4 moles I-ICHO per mole diamine. The product was 82.5% active of tetra(N-methylol-Z-carbamoylethyl)polyether diamine Ll000.

EXAMPLE XVII For the preparation of tetra(2-carbamoylethyl)polyether diamine L2000 (Compound XVII) 200 grams (0.1 mole) of polyether diamine L2000 were dissolved in 500 EXAMPLE XVIII For the preparation of tetra(N-methylol-Z-carbamoylethyl) polyether diamine L2000 (Compound XVIII) 178.70 grams (0.078'2 mole) of tetra(2-carbamoylethyl) polyether diamine L2000 were mixed with 25.40 grams of 37% I-ICHO solution. This ratio gave 4 moles HCHO per mole diamine. The product was 92.3% of tetra(N- methylol-2-carbamoylethyl) polyether diamine L2000.

B. Preparation of impregnating liquor The above listed compounds were used in the preparation of the solutions for impregnation of fabrics. Three sets of experiments were carried out.

In the first set Polyethylene Glycol 600 (a commercial brand of the compound HO(CH CH O H of the average molecular weight 600) and one of the methylol compounds were dissolved in water. The molar ratio of these compounds was 0.88 mole Compound II, 0.66 mole Compound IV, 0.66 mole Compound VI, 0.53 mole Compound VIH, 0.53 mole Compound X, 0.66 mole Compound XII, 0.66 mole Compound XIV, 0.66 mole Compound XVI and 0.66 mole Compound XVIII to 1 mole Polyethylene Glycol 600.

In the second set each of 0.75 mole Compound XIV, 0.75 mole Compound XVI or 1 mole Compound XVIII was mixed with 1 mole of Compound I.

In the third set the following pairs of compounds were dissolved in equimolar quantities: Compound III and Compound IV; Compound V and Compound VI; and Compound III and Compound VI; Compound V and Compound IV.

The aqueous solutions were diluted to contain 12.5 grams of solids consisting of the above mixtures in 100 ml. The solution was adjusted to a pH value of 2 to 2.5 by addition of dilute hydrochloric acid. In addition, the catalyst, 4 to 15 grams of MgCl .6H 'O per 100 ml. solution was added.

C. Impregnation and drying of fabric In each of the above described solutions, a plain weave, desized Dacron polyester fabric, using a separate piece for each of the solutions, was saturated by immersing it into the solution and leading it between rolls of a laboratory pudding machine. It was found that the fabric had retained approximately 40 percent of its own weight of solution containing aproximately 5 percent finishing compounds on the weight of the fabric. The fabric pieces were dried for 7 minutes in an oven at to C.

D. Heat curing The dried fabric pieces were placed in a hot-air oven of to C. and kept there for 5 minutes.

E. Behavior of the finished fabric After removal of the unreacted finish and the catalyst by rinsing with water, the fabrics were investigated for their tendency to accumulate electrostatic changes. Whereas the unfinished fabric attracted cigarette ash if rubbed against worsted fabric and then rapidly placed at a height of 0.5 inch over the ash, all of the treated fabrics remained free of ash if tested identically. Fora quantitative test, the electrical resistance values of the fabrics were determined. It is known that electrical charges are dissipated rapidly if the surface area resistivity (SAR) is below 10 ohms (log SAR 12). Whereas the untreated fabric has shown a surface area resistivity higher than 10 ohms, the finished fabrics have surface area resistivities below 10 ohms. Specifically, the results were as shown in Tables I, II and III.

7 TABLE 1 (Set I) Polyethylene Glycol 600 and Examples: Log SAR XIX Compound II 9.3 XX, Compound IV 8.6 XXI, Compound VI 9.0 XXII, Compound VIII 8.6 XXIII, Compound X 8.6 XXIV, Compound XII 9.4 XXV, Compound XIV 8.5 XXVI, Compound XVI 8.4 XXVII, Compound XVIII 8.6

TABLE II (Set II) Examples: Log SAR XXVIII, Compound I with Compound XIV 9.9 XXD(, Compound I with Compound XVI 10.1 XXX, Compound I with Compound XVIII 9.8

TABLE III (Set III) Examples: Log SAR XXXI, Compound III with Compound IV 10.1 XXXII, Compound V with Compound VI 10.6

XXXIII, Compound III with Compound VI 10.5 XXXIV, Compound V with Compound IV 11.4

It is to be noted that the finishes of Set III while still possessing antistatic properties are less efficient than the finishes of the first two sets, which contain polyoxyethylene chains.

Further tests which were conducted 'have shown that the antistatic protection was maintained after several washings and dry cleanings.

Although the above examples are carried out with a woven fabric, textile materials in other form, such as fiber, filaments, tow, yarn, knitted fabric as well as non-woven structures, flocked and Itufted fabrics can be likewise treated.

In addition to hydrophobic textile materials made of synthetic fibers such as nylon, polyester, cellulose triacetate, acrylics, modacrylics, polyvinylchloride, polyolefins, those made of wool have also tendency to accumulate electrostatic oharges and therefore need antistatic finsh. Blends made of hydrophobic fibers and hydrophilic fibers, such as rayon and cotton likewise require antistatic protection if the ratio of the hydrophobic fibers is substantial.

In order to increase the antistatic efficiency, the amine groups of the carbamoylethyl compounds can be partially or completely converted into quaternary ammonium compounds. For this purpose, the carbamoylethyl complied as free bases in order to maintain their reactivity towards the alkylating agents.

The antistatic finish described can be combined with other finishing agents. Particularly convenient is the com- 'bination with other finishes based on nitrogenous resins (urea/formaldehyde, melamine/formaldehyde and the like). These finishes require catalysts and heat-curing of the same kind as the antistatic finish and therefore can be applied simultaneously with it, making additional steps superfluous. Particularly desirable are such combinations in the finishing of textile materials of blends. Softeners, lubricants, water repellents, stain repellents, anti-bacterial agents, dyes and pigments can be like-wise combined with the antistatic finish.

While certain specific examples and preferred modes of practice of the invention have been set forth it will be understood that this is solely for the purpose of illustration and that various changes and modifications may be made without departing from the spirit of the disclosure and the scope of the appended claims.

I claim:

1. A process of reducing the tendency of textile materials containing a substantial portion of hydrophobic fibers to accumulate electrostatic charges which comprises impregnating said textile material, to give a total dry weight add-on of between 0.4% and 8% by weight based on the weight of said textile material, with an aqueous acidic solution of -(A) a mixture of Z-carbamoylethyl compounds and their N-methylol derivatives selected from the group consisting of (1) 0.75 mole to 1 mole of a water-soluble compound of the formula CH --CH CONHCH OH 2 where R, is a bivalent organic radical containing a polyoxyethylene chain of the formula (CH CH O) where n is an integer from 3 to 80, with about 1 mole of a. water soluble compound of the formulae selected from the group consisting of (NI-I COCH CH 3EN and where p is an integer from 2 to 6 and R is selected from the group consisting of R and where m is 0, and (2) 0.53 mole to 0.88 mole of a watersoluble compound of the formulae selected from the group consisting of and pounds are treated with alkylating agents, such as diethylsulfate, dimethylsulfate, elthylbromide, ethylenechlorhydrin, 'benzylchloride or ethyliodide, before or afiter reacted with formaldehyde. Quaternization can also be carried out on the textile materials during or after curing. For this purpose, it is convenient to use non-volatile watersoluble alkylating agents, such as polyethyleneglycol diiodide (I(CH CH O) CH CH I) in which x is a number between 5 and 40, preferably between 12 and 15. These agents can be dissolved in the impregnating solution containing the resin forming components and the catalyst. The use of amine catalyst in this case must be avoided and the carbamoylethyl compounds not neutralized but apwherein R, R R and m have the above-assigned values, with about 1 mole of a polyethylene glycol having from 3 to oxyethylene units, and (B) an acidic catalyst, removing the water from said impregnated textile material and exposing said dried, impregnated textile material to a temperature between C. and 200 C. for a time sufiicient to cure said mixture.

2. A composition for treating textile materials containing a substantial position of hydrophobic fibers consisting essentially of an aqueous acidic solution of (A) a mixture of Z-carbamoylethyl compounds and their 'N-methylol derivatives selected from the group consisting of (1) 0.75 mole to 1 mole of a water-soluble compound soluble compound of the formulae selected from the group of the formula (HO CH NH-C OCHz-CH2)2=NR4N=(CHg-CHg-C o-NH-ornoH where R; is a bivalent organic radical containing a polyconsisting of oxyethylene chain of the formula (CH CI-I O) where n wherein R, R R and m have the above-assigned values, is an integer from 3 to 80, with about 1 mole of a water with about 1 mole of a polyethylene glycol having from soluble compound of the formulae selected from the 3 to 80 oxyethylene units, and (B) an acidic catalyst. group consisting of and z-C 0-CH2C 2)2= 1-N=( 2C 2C 0-NH2): CHrCHr-C O-NHgJ where m is an integer from 0 to 1, R is (CH where References Cited p is an integer from 2 to 6 and R is selected from the 30 UNITED STATES PATENTS group consisting of R and 2,663,733 12/1953 Subluskey 1l7--139.4 X 3,167,384 1/1965 Andrews et a1. 117161 CH 3,168,415 2/1965 Goldstein et al. 117-139.4 2 5 35 3,202,473 8/1965 Andrews et al. 117-143 Ami-cg CH-CHT" 3,247,018 4/1966 Hagge et a1. 117139.5 cm-ofi, 3,258,305 6/1966 Andrews et a1. 117-161 WILLIAM D. MARTIN, Primary Examiner.

when m is 0, and (2) 0.53 mole to 0.88 mole of a water- 40 T. G. DAVIS, Assistant Examiner.