US3376245A - Antistatic composition containing polyepoxide resin - Google Patents

Description

United States Patent Office 3,376,245 Patented Apr. 2, 1968 3,376,245 ANTISTATIC COMPQSITION CONTAINING POLYEPOXIDE RESIN Byron A. Sample, Jr., Bertie J. Reuben, and Julian J.

Hirshfeld, Decatur, Ala., assignors to Monsanto Company, St. Louis, Mo., a corporation of Delaware No Drawing. Filed May 15, 1964, Ser. No. 367,860 9 Claims. (Cl. 260-292) ABSTRACT OF THE DISCLOSURE This invention relates to a novel composition and process of rendering antistatic protection to a synthetic textile without discoloring the same by incorporating phosphoric acid or hypophosphorus acid in an aqueous dispersion of an antistatic composition consisting of a high molecular Weight polyamine and a polyepoxide obtained as a condensation product of epichlorohydrin and a polyol.

This invention relates to compounds which, when applied to a synthetic textile fiber, have antistatic characteristics. More particularly, this invention relates to antistatic compounds which 'when applied to synthetic fibers in the presence of a phosphorus containing 'acid render an undiscolored, static free fiber.

Snythetic fibers when coming into contact with foreign objects tend to collect static electrical charges thereon which is objectionable during the manufacture and wearing thereof. The accumulation of static charges thereon prevents the finished fabrics from draping like cotton or wool and causes the same to cling uncomfortably to the wearer. The static charges also attract dust and lint to the fabric. It is well known in the art that polyamines 'are effective temporary antistatic agents and when associated with the fibers which comprise a fabric in the presence of a polyepoxide, the polyamine molecules and the polyepoxide molecules crosslink thereon and become durably attached thereto. The methods and compositions are clearly shown in US. Patent No. 3,021,232 to Pretka and US. Patent No. 2,982,751 to Anthes, respectively. However, it has been found that when a fiber is treated with a polyamine compound, a discoloration results which is undesirable and which lowers the commercial value of the fiber. An afterwash is only partially eifective for it does not remove all of the discoloration. It also is an additional operation which is objected to as being time and money consuming. It is to this problem that attention of this application will be directed.

Therefore, an object of this invention is to provide a novel process which will impart to a synthetic textile fabric antistatic properties without discoloring the same.

Another object of this invention is to provide a novel composition of matter which renders antistatic protection to a synthetic textile fabric without discoloring the same.

A further object of this invention is to provide synthetic fibers which retain their original color with an antistatic agent.

A still further object is to provide a water-soluble antistatic composition which is compatible with pH sensitive yarn-finishing ingredients.

These and other objects will become apparent in the course of the following specifications and claims.

In accordance with a preferred embodiment of the present invention, a synthetic textile fiber is provided with durable antistatic properties by continuously associating the fiber, either during the spinning thereof or when the fiber is in fabric form, with an aqueous polyamine/ epoxy resin suspension which also contains a third ingredient. This third additive controls the pH of the suspension which is tantamount to controlling the fiber whiteness and the tenacity with which the polyamine clings to the fiber. The polyamine polyepoxide solution readily polymerizes on the synthetic fiber at pH values above 7.0. However, the increase in pH increases the discoloration. Although a decrease in pH prevents to a certain degree the discoloration of the fiber due to the treatment, it decreases, at the same time, the effectiveness of the treatment. This invention discloses the art of reducing the pH for complete prevention of discoloration without any decrease of the effectiveness of the treatment.

The use of these antistatic agents, in accordance with the present invention, effects improvements in the characteristics of acrylonitrile polymers and articles produced therefrom. This invention is applicable not only to polyacrylonitrile, but also to copolymers, interpolymers and blends thereof, particularly those containing at least percent by weight of polymerized or copolymerized acrylonitrile. Such polymeric materials include acrylonitrile fiber-forming polymers wit-h readily dyeable basic copolymers the blend having 'an overall polymerized acrylonitrile content of at least 80 percent by weight.

An acrylic fiber may be formed by extruding a typical acrylonitrile-based spinning dope through a conventional spinnerette into an aqueous coagulation bath wherein the dope hardens into a filament. After the fibers were Washed and stretched as they were drawn up a hot water cascade, they are heated and partially dried on a set of drying rolls. When the moisture content of the fiber is approximately 20 percent by weight and the temperature of the filaments has reached approximately C., they are immersed in an aqueous emulsion which contains (a) 'a polyamine, (b) an epoxide resin, and (c) a lubricant.

Where the aqueous emulsion is applied to a fabric by padding, or the like, the lubricant may be eliminated for there is no problem of the fibers wrapping around the drying rolls. However, where the antistatic finish is being applied to synthetic fibers during the manufacture thereof, a lubricant is a necessary additive for the fibers have the tendency to stick to the drying and curing rolls without it. The mixture preferably contains a dispersing or emulsifying agent which insures a more homogeneous suspension ofthe several ingredients. The temperatures of the suspension is generally held at below 40 C. in order to prevent premature polymerization.

The use of polyamine compounds as antistatic agents, while being an excellent antistat, is limited to applications where the aqueous emulsion is kept at a pH of below 7. If the pH of the suspension is allowed to rise above 7, the effectiveness of the antistat is destroyed somewhat for the discoloration limits the use of the fiber. Further, the effectiveness of the antistatic finish is reduced as the pH approaches zero. By the addition of phosphorous containing acids to the suspension, the pH can be effectively reduced to the desired level without adversely affecting the antistatic properties of the treatment. The reduction of the pH destroys the discolon'ng characteristics of the polyamine thereby allowing the polyepoxide/polyamine solution to readily polymerize on the surface of the fibers. It has been found that only the phosphorus containing acids have these characteristics and of these, the most efiective ones are phosphoric acid and hypophosphorus acid. Either of these acids are added directly to the polyepoxide/polyamine suspension before the fiber is immersed therein. The acids also aid in the dye receptivity of the fiber.

4 a An example of a polyamine in accordance with the Ohromey apparatus to determine the level of static propresent invention is a polyamine having the formula: tection after selected washings. To determine the effectiveness of the phosphorus containing acids in preventing H *(D Am-qE)DflH discoloration of the synthetic fibers at lower pH levels,

when -D is a diva radical terminating in amino 5 the fabric is tested according to standards established by nitrogen, is a divalent radical Selected from the the American Association of Textile Chemists and Colorgroup consisting of ists. Such test results are then compared with emulsions which do not contain the phosphorus containing acids. H H a The examples will show that in every test run, the gray iG-O OC C- O scale rating for the treated fabrics increased from an H l; unacceptable value to an acceptable one upon the addition of the phosphorus containing acids. and a mixture of these radicals wherein -R- is a lower The following examples are cited to illustrate the ina'lkyl radical, -E- is a divalent radical selected from vention. They are not intended to limit this invention in the group of desoxy -A-- radicals (i.e., an -A- radiany way. Unless otherwise noted, parts as expressed in cal without its oxygen atom), in is a whole number from the examples indicate parts by volume. about 5 to 85 and n is a Whole number from about 1 t0 about 50. The preparation of these polyamines is dis- Examp 16 I cussed in Belgian Patent No. 554,506, granted J an. 25, A sample of acrylic fibers consisting of a copolymer of 1957 20 93 percent acryl-onitrile and 7 percent vinyl acetate in The epoxide resin referred to above can be prepared by the form of a fabric were treated y P P i condensing e ichlorohydpin i h a 1 1 1 A t i l dripping, washing and the like, with an aqueous emulsion ample is the condensation product (with elimination of h ving h f ll wing constituents: HCl) of glycerine and epichlorohydrin. The preparation Percent thereof is described in detail in British Patent No. 780,288, 5 POlYBIIIlHB 5 dated July 31, 1957. Such material is available on the Polyepoxide open market under the trademark Eponite 100. vgly l other 125 When an aqueous bath is prepared from water, a poly- Water 94-22 I f an epoxy resin f agent= is The total finish solids constituted at least 0.4 percent slmble to a thereto a msufe a of the weight of the fiber. The pH of the above aqueous thorough m xture of the respective ingredients. Sat1sfac emulsion was adjusted 65 by the addition of Phosphoric wry dlspersmg or emulslfymg agents are the amma'nc acid. Several tests were run wherein the total finish ap- Polyglycol hers, one example such being the alkyl' plied to the fiber was varied over a wide range by changing phenol polyglyco'l ether contammg 9.5 moles of ethylen the relative concentrations of the finish ingredients which oxide which can be purchased on the open market under eomprise the aqueous emulsion. Table I (immediately the trademark Y below) compares the Gray Scale Rating of the emulsion The effectiveness of the Phosphorus Containing acids in containing and not containing phosphoric acid, the highreducing discoloration was checked in the manner as set est on the Gray Scale Rating being 5 and the lowest forth below. Where the antistatic emulsion is applied to a being 1.

TABLE I Gray Scale Rating Suspension pH As Blank Basie Dispersed Received Dyed Dyeing Dyeing Polyamine/Polycpoxide 9.9 2 1-2 1 1-2 Polyarnine/Polyepoxide with Phosphoric acid 6. 5 3-4 2-3 2 2-3 tow, the finished filaments are converted into yarn and 5 Mm Blanknyemg static the yarn is knitted mm a tubular fabric shape whereupon Half Life" in seconds the fabric is blank dyed by any conventional dyeing procsuspensc'n m ess. Where the antistatic emulsion was applied to a fin- Launderings Leundcrings ished fabric, it was also blank dyed by a conventional Polyammelpolyepoxide 2 5 dyeing process. Hereinafter, the testing processes are the Poi a uneuoly m Phossame for both types of samples. The fabric is washed in p 3 4 a Kenmore washing machine at 100 F. using 0.5 percent Tide detergent for four minutes or alternatively, Examplfi H a 0.3 percent solution of tetrasodium pyrophosphate may The finish solution applied to acrylonitrile-based fiber be used as the detergent. After the tube is removed from as described in Example I was modified by substituting the washing machine, it is centrifuged to remove the exhypop'hosphorous acid for phosphoric acid and adjusting cess moisture. The steps of washing the tube in the de the pH of the emulsion therewith to 6.5. The remainder tergent for four minutes, centrifuging it and drying it in of the elements were added in the proportions of Exan air atmosphere with a relative humidity of 35 percent ample I. The samples herein disclosed were evaluated acat a temperature 72 F. are repeated a selected number of e cording to the procedure of Example I and yielded the times, whereupon the fabric is run on a Hayeck and results illustrated in Table II.

Polyaruine/Polyepoxide with Hypoplrosphorous acid 3 2-45 2 3 3 As previously described, a synthetic textile filament in the form of a tow or fabric is treated with an aqueous emulsion comprising the mixture of a polyepoxide and a polyamine, the mixture having the pH thereof adjusted by the addition of phosphorus containing acids. The concentration of the reactants in the suspension may vary widely; however, emulsions containing from about 1 percent to about 30 percent by volume of reactants are generally preferred. Such an emulsion will be able to provide a synthetic fiber with an adequate amount of antistatic protection without having the undesirable discoloration which is generally present when .a synthetic fiber is associated with a polyamine. After the fiber has been associated with the antistatic aqueous emulsion, the reactants are cured thereon by raising the temperature thereof to 145 C.

Many diiferent modifications ot the invention may be made without departing from the scope and spirit thereof. It is contemplated that variations may be made in the percentages of the compounds used without greatly altering the antistatic characteristics of the fiber; therefore, the applicant does not wish to be bound by the numbers exactly as they appear herein.

We claim:

1. An antistatic composition useful for imparting antistatic properties to a synthetic textile Without the discoloration thereof, said composition comprised of (a) a polyamine having the formula:

nitrogen, A is a divalent radical selected from the group consisting of and a mixture of these radicals wherein R is a lower alkyl radical, E is a divalent radical selected from the group consisting of H t I i? i trrec and a e H H H H H H H m is a whole number from about 5 to about and n is a whole numbe from about 1 to about 50,

(b) a polyepoxide obtained as a condensation product of epichlorohydr-in and a polyol,

(c) a phosphorus containing acid selected from the group consisting of phosphoric acid and hypophosphor-us acid, and

(d) a dispersing agent.

2. The composition of claim 1 wherein the polyepoxide is a condensation product of glycerine and epichlorohydrin.

3. The composition of claim 1 wherein the dispersing agent is an aromatic polyglycol ether.

4. The composition of claim 1 wherein said composition is comprised of:

(a) about 5.0% of the polyamine,

(b) about 0.5% of the polyepox-ide,

(0) about 0.125% of the dispersing agent,

(d) enough of the phosphorus containing acid to adjust the pH of the composition to about 6.5, and

(e) the residue water, the percent-s based on weight of the composition.

5. A process of imparting antistatic properties to a synthetic textile by treating said textile with the composition of claim 1.

6. The process of claim 5 wherein the synthetic textile is an acrylic textile.

7. A synthetic textile treated by the composition of claim 1.

8. An acrylic filament treated by the composition of claim 1.

9. An acrylic fabric treated by the composition of claim 1.

References Cited UNITED STATES PATENTS 2,965,517 12/1960 Albrecht et al. 2602 3,040,076 6/1962 Seidel et al 260-615 WILLIAM H. SHORT, Primary Exwmz'ner. T. E. PERTILLA, Assistant Examiner.