IL36805A - Antistatic filaments - Google Patents

Description

¾Κ»ANTISTATIC POLYAMIDE FILAMENTS & ANTISTATIC FILAMENTS ABSTRACT OF THE DISCLOSURE Synthetic melt -spun polyamide filaments are provided having uniformly admixed therein, as a separate phase, from about 1% to about 15% by weight of the polyamide of an amine of the structure wherein each R is an alkyl group, R ' is an alkylene group and n is an integer of at least 15. Yarns, fibers and fabrics made from these filaments possess permanent antistatic properties, even after numerous launderings .

ANTISTATIC FILAMENTS BACKGROUND OF THE INVENTION Synthetic polyamide fibers are widely used in the manufacture of textiles. Unfortunately, these fibers are poor conductors of electricity and as a result charges of static electricity are created and accumulated thereon. The accumulation of static charges on fibers is objectionable to the manufacturer during processing of the fibers and particularly to the user of textiles made therefrom; for example, almost everyone has witnessed the effects of the accumu- I lation of static electricity charges on the surface of wearing apparel, carpets, upholstery and the like, constructed from synthetic polyamide fibers.

Several approaches have been attempted in an effort to eliminate or at least to reduce the creation and accumulation of static electricity charges on the surface of polyamide fibers. One approach has been to apply a surface coating to the fibers to render them more conductive. These coatings however lack durability or impart an undesirable hand to fabrics. Another approach has been to modify the polyamide structure by introducing hydrophilic monomers into the polyamide molecule. However, this approach tends to adversely affect the physical properties of the fibera.

Yet another approach to providing antistatic fibers has been to admix an antistatic material with the polymer prior to shaping.

Various antistatic materials or additives have been used for this purpose, for example: poly(alkylene ethers), such as polyethylene more antistatic, the shaped articles nevertheless still accumulate noticeable charges of static electricity. In many instances fabrics constructed from fibers containing the prior art materials lose their antistatic properties after the fabric is washed or laundered.

Moreover, often a relatively large amount of the material must be used which tends to adversely affect the physical properties of the shaped article.

An object of the invention is to provide a linear synthetic polyamide filament or fiber having improved and permanent antistatic properties.

Another obj ect of the invention is to provide fabrics constructed from polyamide filaments or fibers which have good antistatic properties even , after multiple washings or launderings. ; SUMMARY OF THE INVENTION The above objects are attained by providing a melt spun synthetic polyamide filament which contains as a separate phase from about 1 % to about 15% by weight, based on the weight of the polyamide, of a tertiary amine of the structure R R— I R 'O - ^ — H wherein each R is an alkyl group having at least 8 carbon atoms, R 1 is an alkylene group having 2 to 4 carbon atoms and n is an integer of at least 15.

The filaments of the present invention are made by thoroughly blending or admixing the tertiary amine with the polyamide prior to extrusion thereof into filaments. This may be accomplished, for sufficient tertiary amine is admixed with the polyamide to provide filaments having as a separate phase between about 3% and about 8¾, based on the weight of the polyamide (o.w.p.), of the tertiary amine. The filaments have excellent antistatic properties which are retained even after multiple washings or launderings . Additionally, fabrics constructed from the filaments, such as carpeting, have good aesthetics.

DESCRIPTION OP THE PREFERRED EMBODIMENTS The following examples are given to further Illustrate the invention. In the examples fabrics knitted from various yarns identified therein were tested to determine, the static build-up on the fabric surfaces and the time, in seconds, required for the dissipation of one.r-half this build-up, i.e., charge.

Prior to the testing, the fabrics were subjected to a specific number of machine launderings wherein after each laundering, ualiiK commercially available detergent, the fabrics were tumble dried a total of 5 times and then conditioned a specified period of time at 0% relative humidity at 73°F. More specifically an electric washing machine was loaded with the test fabric and sufficient cotton fill fabric to make 4 lbs. total load. One-half cup (125 cc.) of the detergent was added and the unit set to wash for 10' minutes with 16 gallons of warm water (48°C) and for warm water rinsings.. . After the washings the fabric was tumble dried at maximum setting In an electric dryer. The ex-hauut air was about -Ui>°C., nd the total drying cycle was '15 minutes. After washing, the fabric was subjected to 5 drying cycles. The testing was carried out on a dynamic static tester similar to that described In Vol. ^O, American Dyestuff Reporter, pp;. 164-168 (1951). In brief, the test is carried out by attaching the test fabric to an aluminum cylinder which is rotated at approximately 300 rpm. The fabric ie then electrostatically charged by allowing it to rub against another similar fabric surface for one minute. Then, while continuing to rotate the cylinder at 300 rpm, the period of time (in seconds) for the static charge build-up on the fabric to dissipate to one-half its original value is measured, In these tests the shorter the time required for dissi pation of one -hal f the static charge build -up, i. e. , static half -life (t 2 ), the greater the degree of antistatic property.

EXAMPLE 1 This example illustrates the preparation of conventional poly-hexamethylehe adipamide (nylon 66) fiber.

To stainless steel, high pressure autoclave was added 150 parts of hexamethylene diammonium adipate and 50 parts of water. The autoclave was equipped with stirring means to permit the content to be iigitoted. Th

Claims (6)

1. * WHAT IS CLAIMED IS: 1. A static resistant melt spun synthetic saturated aliphatic polycarbonamide filament containing as a separate phase from 1% to 15 by weight, based on the weight of the polyamide, of an amine of the structure wherein each R is an alkyl group having at least 8 carbon atoms, R' is an alkylene group having 2 to carbon atoms and n is an integer between 15 and 0.

2. The filament of claim 1 wherein said polycarbonamide is polyhexamethylene adipamide.

3. The filament of claim 1 wherein., said polycarbonamide is polycaprolactam.

4. The filament of claim 1 wherein R' is -CH2CH2— .

5. The filament of claim 4 wherein each R is CHa(CHp'^- . . 5 - .. : ■ 17

6. The filament of claim 4 wherein each R is CH (CH- , • 5 ■ - 11 7, The filament of claim 4 wherein each R is an alkyl group having from 12 to 30 carbon atoms. 8. The filament of claim 4 wherein n is between about 30 and about 200. filament containing between about 1 and 8$ by weight, based on the weight of polyhexameth lene adipamide, of an amine of the structure wherein m is in integer between about 30 and 200. 10. The filament of claim 9 wherein m is between about 35 and 100, 11. The filament of claim 9 wherein m is between about 50 and 75.