US3503795A - Durable resinous antistatic textile finish - Google Patents

Description

United States Patent 3,503,795 DURABLE RESINOUS ANTISTATIC TEXTILE FINISH Tsai Hsiang Chao, Somerville, N.J., assignor to American Cyanamid Company, Stamford, Conn., a corporation of Maine No Drawing. Filed May 4, 1967, Ser. No. 635,999 Int. Cl. D06m 11/00 US. Cl. 117-1395 9 Claims ABSTRACT OF THE DISCLOSURE This invention relates to a durable antistatic textile finish produced by reacting a condensate of a polyamine with a halohydrin ether of a polyalkylene polyhydric alcohol with N,N'-methylenebis(acrylamide) and to the process of applying the finish to a synthetic hydrophobic textile material and to the textile material prepared by said application.

This invention relates to a durable, antistatic textile finish. More particularly it relates to a durable antistatic finish for hydrophobic textile materials, a method of applying the finish to such materials and to the materials thus treated.

In general, textile fibers, yarns and fabrics made from synthetic hydrophobic materials, as for example the nylons, the acrylic fibers, the polyester fibers, acetate fibers and the like, become electrostatically charged whenever and wherever friction is applied to them. Therefore many disadvantages are encountered during the mill processing and fabricating and more so during the end use of the materials manufactured. Aside from the discomfort to the individual wearing a garment which accumulates static electricity, there is also the serious problem of the attraction of dust and dirt particles which results in the garment having a soiled appearance. This usually causes frequent launderings or dry cleanings resulting in poor fabric life due to degradation caused by detergents and bleaches and the normal abrasion resulting from such processing.

The elimination of the static electricity in fabrics would ease the manufacturers problems, give more comfort to the consumer, and add greater life to the textile materials. It would also reduce hazardous conditions found in such places as operating rooms or in other places where ignition from static electricity could be dangerous.

Antistatic treatments of hydrophobic textile materials subject to the accumulation of static electricity are not new and have been employed by many in the past. However, many of these treatments have marked disadvantages; typical of these are the following: complicated methods of application, inability to be applied from aqueous media, incompatibility with other chemicals, poor durability and soil-retentiveness of the finish applied when subjected to washing or dry cleaning, discoloration of the fabric, and loss of fabric strength or odor problems during pressing.

Typical commercially available antistatic agents exhibit wet-soil indices of 42, 27, and 20, for example, using untreated nylon fabric as a standard index of 1.0. High wet-soiling index is a major reason why many antistatic finishes, which are otherwise satisfactory, are not presently in common commercial use.

In the ever increasing field of man-made fibers subject to the accumulation of static electricity, there is a genuine need for a good, durable antistatic treatment which when properly applied will not impart any important deleterious side effects upon the textile material finished therewith or cause discomfort to the consumer.

Accordingly, it is an object of the present invention to provide an antistatic finishing composition which, when 3,503,795 Patented Mar. 31, 1970 applied to synthetic hydrophobic textile materials subject to the accumulation of static electricity, will impart thereto a durable antistatic finish.

A further object of the invention is to provide an antistatic finish capable of application in a conventional straightforward manner from an aqueous medium and which is compatible and stable with other textile agents and auxiliaries.

It is a still further object of the present invention to provide an antistatic finish which does not discolor fabrics finished therewith, does not reduce fabric strength, and does not result in odor problems during pressing or upon completion of finishing.

Another object of this invention is to provide an antistatic finish having a high degree of durability to washing and dry cleaning, etc.

Another object is to provide an antistatic finish having a desirably low affinity for soil.

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

In my copending application Ser. No. 439,996, filed Mar. 15, 1965, now Patent No. 3,411,945 is disclosed an antistatic finish for textiles prepared by reacting a polyalkylene glycol-polyamine resin with cyanuric chloride. This finish has good antistatic properties and is durable to laundering, but is not so durable to dry cleaning. Moreover, cyanuric chloride, being an acid chloride, is unstable (hydrolyses in presence of moisture), is ditficult to handle, and has a pungent odor, thus presenting problems in the manufacture of the antistatic agent.

It has now been discovered that an improved antistatic agent for textiles can be obtained by reacting a polyalkylene glycol-polyamine resin with N,N'-methylenebis- (acrylamide) (Formula I).

The antistatic finish of this invention has good antistatic properties, is durable to laundering and dry cleaning and is free of disagreeable odor. Furthermore, the problems presented in using the unstable, odiferous cyanuric chloride as disclosed in my copending application Ser. No. 439,996, have been unexpectedly eliminated by the use of the stable, non-odiferous, N,N'-methylenebis- (acrylamide) The polyalkylene glycol-polyamine resins utilized in the reaction with N,N'-methylenebis(acrylamide) in this invention are the reaction product of one or more halo hydrin ethers reacted with one or more polyamines. Halohydrin ethers suitable as reactants include halohydrin ethers of polyalkylene polyhydric alcohols.

Halohydrin ethers with which this invention is concerned are generally prepared from polyalcohols by the use of an epihalohydrin, the process being well known. The preferred epihalohydrin is the chloro-compound epichlorohydrin. Other epihalohydrins are epibromohydrin and epiiodohydrin.

Condensation catalysts are used in reacting an epihalohydrin with a polyalcohol for the formation of a polyhalohydrin ether. Typical catalysts are those of the Lewis acid type, including anhydrous AlCl ZnCl SnCl and complexes such as the well-known BF etherates, etc., and the Bronstead acid type, including HF, H and the like. Concentration of the catalysts may be varied from 0.1 percent to 2.0 percent depending upon the individual catalysts. A reaction temperature between about 70 C. and about 80 C. is recommended when boron trifluoride etherate is used as the catalyst.

Suitable polyalcohols include the preferred polyethylene glycols with average molecular weights between about 200 [and about 2,000, but molecular weights between about 500 and about 1,000 are preferred. Although it is preferred to use about 2 moles of epihalohydrin per mole of polyethylene glycol, between 1 mole and 3 moles may be used. If 2 moles of epihalohydrin are employed, the resulting halohydrin ether is a mixture of products, but the predominant product is believed to be of the typical structural formula shown below:

OH OH XCH2-(EHCH2O(-CH2-CH2O)uCH2-( 3HGHzX where X is a halogen, and where n is an integer larger than zero.

Examples of other polyalcohols are: polypropylene glycols, and polytrimethylene glycols.

The polyamine reactant includes amines having two or more primary or secondary amino groups on separate carbon atoms, for example: trialkylenetetramines, such as triethylenetetramine; ethylenediamine; propylenediamine; hexamethylenediamine; trimethylenediamine; tetramethylene diamine; tetraethylenepentamine; 'diethylenetriamine; dipropylenetriamine; etc.

The amines suitable for use in this invention are represented by the following typical formula:

Where m and it each represent an integer larger than zero.

To form the polyalkylene glycol-polyamine antistatic resin, by reaction of halohydrin ether and amine, the reaction temperature may range from about 65 C. to about 135 C. The preferred temperature range, which gives an antistatic agent having superior antistatic properties, ranges from about 80 C. to about 100 C. Although it is not necessary to employ a solvent for the reaction of halohydrin ether and amine, it is desirable to use a solvent such as alcohol, dioxane and especially water.

In carrying out the reaction of the halohydrin ether and the polyamine, the polyamine is added to the halohydrin ether, and the exothermic reaction is controlled by the rate of addition. In the reaction of the amine with the polyhalohydrin ether, an amine-hydrohalide salt is formed. This amine salt is then desirably reacted with an inorganic alkali to neutralize the hydrogen halide. Suitable alkalies are carbonates or bicarbonates of alkali metals, for example, sodium bicarbonate, sodium carbonate, potassium carbonate, potassium bicarbonate, etc., and one equivalent, or less, of alkali per halohydrin group is generally used. Moreover, the alkali can be added at the start of the reaction.

In the reaction of a polyalkylene glycol-polyamine resin with N,N'-methylenebis(acrylamide) the reactants are mixed under essentially neutral conditions and the reaction is continued until a homogeneous composition is obtained indicating completion of the reaction.

The polyalkylene glycol-polyamine resin does not have to be isolated before reacting with N,N'-methylenebis (acrylamide). The pH of the resin is adjusted to slightly below 7.0 by adding s-ufiicient acid, such as acetic acid, to neutralize sodium carbonate present. The amount of N,N'methylenebis(acrylamide) used is between 5% and 25%, preferably between and 20%, based on the weight of the polyalkylene glycol-polyamine resin. It 'is advantageous to add the N,N-methylenebis(acrylamide) as a slurry in water. The reaction is carried out at a temperature between 50 and 90 0, preferably between 70 and 80 C. The reaction mixture may be diluted with water to the desired. content of antistatic agent. For storage stability, it is desirable to adjust the pH of the finished antistatic agent to between 5 and 6 with an acid such as acetic acid.

In the preferred process for the novel antistatic resin of this invention, polyethylene glycol with average molecular weight of 600 is reacted with 2.2 moles of epichlorhydrin per mole of polyethylene glycol in the presence of a catalytic amount of boron trifluoride-etherate. The epichlorhydrin is added slowly to the mixture of polyethylene glycol and catalyst at a temperature between about 70 C. to about 75 C., while cooling externally. To this reaction mixture, sodium'carbonate is added, and the mixture is boiled to destroy the catalyst and to remove trace amounts of the more volatile materials. About 10% of triethylenetetramine, based on the weight of the halohydrin ether product present is added slowly at a temperature of between about C. to about 100 C. Glacial acetic acid is then added to give a pH slightly below 7. After the evolution of carbon dioxide ceases, a suspension of N,N'- methylenebis(acrylamide) (about 10% based on the weight of the polyalkylene glycol polyamine component) in water is added at a temperature of about 70 C. After a further period of reaction, the homogeneous solution is treated with glacial acetic acid to obtain a pH of about 5.5. The yield of active ingredient is considered to be quantitative.

The synthetic hydrophobic textile materials which may be treated with the products of this invention include synthetic materials such as nylon, acetate rayon, acrylic fibers, and terephthalic acid-ethylene glycol condensation products, for example. Any synthetic product which characteristically accumulates static electricity is the type of material on which the antistatic agent of this invention may be advantageously applied. The materials may be in the form of woven or non-woven goods, tufted and pile fabrics, knitted goods, felted goods and fibers both staple and filament. Applications can be made by padding, spraying, or any appropriate means. The finishes are conveniently applied from an aqueous bath.

Applications for the products of this invention may be made under slightly acidic, neutral or alkaline conditions in a range between about pH 6 and about pH 11.0. The preferred pH range is between pH 9 and pH 10.

Between about 0.25% and about 5.0% O.W.F., preferably between about 0.5% and about 2.0%, of the products of this invention is applied to the fabrics. The treated textile materials are normally dried by conventional methods, e.g., at about 225 F. for 1-2 minutes. If desired, the treated textile materials can be heated at higher temperatures for short periods of time, but this is not required.

The following specific examples are Set forth to illustrate the invention and are not intended to be limitative.

In the following examples, the parts and percentages are by weight.

EXAMPLE I To an anhydrous mixture at 70-75 C. of 225 parts (0.375 mole) of polyethylene glycol (average molecular weight 600), and 0.5 part boron trifluoride catalyst, introduced as a solution in about one part of ether, there was added over a period of about one hour 77 parts (0.825 mole) of epichlorohydrin. The reaction mixture was maintained at a temperature of 7075 C. for about 2.5 hours, adding 0.5 part of boron trifluoride as a solution is about 0.5 part of ether after the first 30 minutes.

To the resulting mixture at about 55 C., there was added a solution of 20.7 parts of sodium carbonate in 47 parts of water. The solution was heated rapidly to boil and held at this temperature for 10 minutes followed by cooling to 90-95 C. There was then added dropwise 28.15 parts of triethylenetetramine in about a 15 minute period. After stirring the mixture at -97 C. for 30 minutes, 23.5 parts of glacial acetic acid was slowly added. After cooling to 70 C., a slurry of 29.6 parts of N,N'- methylenebis(acrylamide) in 210 parts of water was added. Stirring was continued at 60 C. for about 45 minutes until a homogeneous solution was obtained. Another 30 parts of glacial acetic acid was added, resulting in a pH of about 5.5 for the solution.

EXAMPLE II The antistatic agent of Example I was applied to nylon tafi'eta by standard padding procedure at 2% solids on the weight of the fabric (O.W.F.) from an aqueous pad bath of pH 9.5 (sodium carbonate). The fabric was dried L 5 at 225 F. for 1.5 minutes and then heated at 300 F. for 8 minutes.

The antistatic activity was measured by a procedure based on Standard Test Method 76-1959 of the American Association of Textile Chemists and Colorists. Before the electrical resistivity of the fabric was measured, the fabric was conditioned in the testing chamber at 70 F. and 30% relative humidity. Resistivity values below 500 10 ohms indicate good antistatic activities; resistivity values below 100x10 ohms indicate excellent antistatic activities.

The washes were carried out in a home-type automatic washing machine using a s nthetic detergent and the washing cycle recommended for delicate fabrics. After the launderings, the antistatic tests were repeated.

The dry cleanings were carried out by contacting a sample of the fabric with a commercial fabric cleaning solvent containing a dry cleaning detergent.

The results are shown in Table I.

TABLE I.-ANTISTATIO ACTIVITY [(Ohms X10 warp] Fabric Initial 10 washes 40 washes 3 dry cleanings Untreated 100 50, 000 50,000 50, 000 Treated 0. 1 0. 6 2. 6. Treated 0. 1 1. 5 2. 7 50, 000

Product of Example II of copending application Serial No. 439,996 for comparison, which is prepared as follows:

To an anhydrous mixture of 450 parts (0.75 mole) of polyethylene glycol (average molecular weight 600) and 1.0 part of boron trifiuoride catalyst, introduced as a solution in about 2 parts of ether, at 70-75 0. there was added over a period of about one hour 153 parts (1.65 moles) of epichlorohydrin. The reaction mixture was maintained at a temperature of 70-75 C. for about 2.5 hours, adding 0.5 part of boron trifiuoridc as a solution in about 1 part ether after the first 30 minutes.

To the mixture at about 5060 C. there were added about 05 parts of Water and 41.4 parts of sodium carbonate. After boiling the mixture for 10 minutes, 56.3 parts (0.385 mole) of triethylene tetramine was added over about minutes at a temperature of 90-95" C. This temperature was maintained for about 30 minutes followed immediately by the addition of 50 parts of glacial acetic acid. The product solution or dispersion was adjusted to contain about 46% of active components.

When the evolution of carbon dioxide had ceased, the reaction mixture was cooled to between 30 and 35 0., and a solution of 59.2 parts (0.325 mole) of cyanuric chloride in 110 parts of dioxane was added slowly at 30 35 C. After an additional reaction period of 30 minutes, 100 parts of water were added, followed by about 30 parts glacial acetic acid to give a pH of 4.0 or lower. The product solution or dispersion contained about 46% of active component.

EXAMPLE III The aqueous pad baths (A and B) were prepared containing the product of Example I. The pH of each of the two pad baths was adjusted by adding sodium carbonate. The baths were applied to nylon taffeta by a standard padding procedure. The fabrics, containing 2% O.W.F. of the active component of the product of Example I, were dried and then heated at 300 F. for 8 minutes.

The treated fabrics were tested for antistatic properties by allowing the fabric to remain for 4 hours in an atmosphere having 33% relative humidity. The fabrics Were then rubbed wth a wooden rod and held over an open dish containing finely divided carbon at a distance of about 1 /2" or lower. If the carbon was not attracted to the fabric, the fabric was considered to be antistatic.

6 The washes were carried out as described in Example II.

The results are shown in Table II.

Table II pH of pad bath: Antistatic durability, washes 7.0 10 9 5 20-30 The example demonstrates the superior durability of the antistatic finish when applied at a pH above 9.0.

While I have set forth certain specific examples and preferred embodiments of my invention, it will be understood that this is solely for purposes of illustration, and that various changes and modifications may be made in the invention without departing from the spirit of the disclosure or the scope of the appended claims.

I claim:

1. A process for preparing a durable antistatic resin comprising (1) reacting at least a molar equivalent of a polyamine with a halohydrin ether of a polyalkylene polyhydric alcohol at a temperature of from about to 135 C., to form a condensate and (2) reacting said condensate with from about 5 to 25% N,N-methylenebis (acrylarnide) based on the weight of said condensate, at a temperature of from about 50 to C.

2. A process according to claim 1 in which said polyalkylene polyhydric alcohol is a polyethylene glycol.

3. A process according to claim 1 wherein said halohydrin is epichlorohydrin.

4. A process according to claim 1 wherein the amount of N,N-methylenebis(acrylamide) is from about 5% to about 25% based on the weight of said condensate.

5. A process for imparting a durable antistatic finish to a synthetic hydrophobic textile material which comprises applying an aqueous solution of the resin produced by the process of claim 1 to said textile and thereafter drying said textile at elevated temperature.

6. A process according to claim 5 wherein the amount of resin applied to said textile is from about 0.25% to- References Cited UNITED STATES PATENTS 10/1963 Frotscher 11716l X 10/1964 Albrecht et al. 117-139.5

WILLIAM D. MARTIN, Primary Examiner T. G. DAVIS, Assistant Examiner US. Cl. X.R.