DE2411715A1 - ANTISTATIC POLYAMIDE FIBER AND METHOD FOR MANUFACTURING IT - Google Patents

Description

ALLIED CHEMICAL CORPORATION, Morristown, N.J. (UNITED STATES.)

Antistatic polyamide fiber and process for its manufacture

The invention relates to a method for the melt spinning of a fiber or thread-like structure from a synthetic polyamide polymer, particularly a method for making improved antistatic fibers, Threads or filaments, yarns or the like. by melt spinning a synthetic, linear, fiber-forming polyamide .

It has already been proposed to increase the utility value of synthetic fibers and their properties, in particular to improve their antistatic properties by using a polyalkylene ether with a high molecular weight is incorporated into the polymer. In particular, in U.S. U.S. Patent 3,475,898, for to use poly (ethylene propylene) ether glycols for this purpose. Somewhat later it was disclosed in US Pat. No. 3,657,386, that certain propylene oxide-ethylene oxide copolymers based on ethylene diamine for the production of an antistatic Polyamide fibers are advantageous.

It has also been proposed to increase the utility value of synthetic fibers made of polyamide by dispersing a to increase the antistatic compound in the polyamide, the antistatic compound being a reaction product from a compound of the general formula

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«Ν
CH-

, 3 j 3

H (OCH ₂ CH ₂ ) _y (OCHCH.) _C (CH ₂ CHO) _a (CH ₂ CH ₂ O) _χ Η

CH, N-Ä-N CH ₃ H (OCH ₂ CH ₂ J ₂ (OCHCH ₂ ) _d fCH ₂ CH0) _b (CH ₂ CH ₂ O) H '

where a, b, c, d, w, x, y and ζ are each an integer and A is a difunctional radical of a hydrocarbon having 1 to 13 carbon atoms, this tetroi compound having a molecular weight between about h, 000 and about 50,000 , and at least one compound from the group of diepoxides and compounds which have the following divalent radicals:

0 0

»Ir

-C-R'-C-, and 0 .0

. ■:. fi η η ι »

-. . . -CNR ¹ -NC-

form, wherein R ^{1 is} a difunctional radical of a hydrocarbon having 1 to 30 carbon atoms.

However, the frequent occurrence of so-called "knobs ^11" in the fibers has resulted in serious difficulties in melt-spinning such fibers.

The term "knobs ¹¹ is used in the usual sense and means here thickened sections of the thread which are not more than several thread diameters in length.

Pimples can be caused by a foreign, non-orientable substance that causes normal fiber stretching in one short section disturbs, and leads to a thickening there.

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Foreign substances suspected to be present in the present If they contribute to the formation of pimples, include carbonized polymers from the front area of the extrusion opening and spinneret and gels formed in the polymer. Gels seem to be the main cause, i.e., the nubs may be caused by a non-orientable gel made of cross-linked polymer. Thermal degradation of the polymer can be an important triggering factor.

The thermal degradation of a polyamide with A content of polyalkylene ether additives occurring reactions are not fully researched. It can be assumed, that a decomposition product is formed by the thermal degradation, which crosslinking members between AmIdgruppen and adjacent polymer chains. The decomposition reaction is slow and eventually builds up a three-dimensional network of molecules, which can be referred to as a polymer gel and optionally a Reach stage where they form an infusible coating on the walls of the reactor and other equipment.

A serious difficulty arising from the formation of such a polymer gel on the inner walls of facilities results, is that from time to time pieces break off and get into the flowing polymer stream where they can cause damage to the spinning device.

The greatest difficulty, however, is caused by that polymer gel, which, although up to the stage of three-dimensional Structure has advanced but has not yet reached the infusible stage. Such a thing Polymer gel is easily carried along with the stream of flowing polymer. As long as it is still melted or at least is soft, it goes through the pump and even the filter system and only shows up as an irregularity or as a difference in viscosity in the spun fiber or

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In the thread. If these strands or threads are then cold-drawn, the imperfections can cause fiber or thread breaks, so that either the entire thread or the yarn (twist) breaks or fuzz forms, which are a quality-reducing defect in the end product or the end product. finished yarn must be scored.

An object of the invention is therefore to avoid the difficulties described by reducing the Gel formation in the molten polyamide to a minimum. It is also an object of the invention to melt spinning the Polyamide to avoid the accumulation of polymer gel on the walls of the reactor, in the pump or in the filter device. Another object of the invention is to improve the uniformity and quality of the molten To improve polymer-made fibers or threads, in particular to largely reduce the formation of pimples in the threads. Other objects of the invention will become apparent from the following description and the attached claims.

These objects are achieved according to the invention by a A method for producing an antistatic polyamide fiber from a fiber-forming polyamide polymer, which is about 1 to 12 wt .- ^ contains an antistatic compound, consisting from a reaction product of a tetrol compound of the general formula

ι ^J ■■ · ■■■■

H (OCH ^ CH-) (0CHCH ₀ ). : · -
2.2 y ^ s5

-; CH, N-A-N

2 2 2 2'd.
where a, b, c, d, w, x, y and ζ are each an integer and A is a difunctional radical of a hydrocarbon having 1 to 13 carbon atoms, the tetrol compound having a molecular weight between about 4,000 and about 50,000 , with at least one compound from the group of Al 58 - 4 -

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Diepoxiden and compounds, like the following divalent radicals:

0 0

11 H.

- ■ · ■. '■■. ■ '' - fl H H Il

;. . : ■ -c-n-r'-n-c-

form, wherein R ^{1 is} a difunctional radical of a hydrocarbon with 1 to 30 carbon atoms, by extruding the molten polymer through a nozzle into a quenching medium or precipitating medium and then stretching the resulting threads. The process according to the invention is characterized in that, prior to extrusion, in the mass to be extruded at least about 0.5 wt. #, Preferably 0.5 to 35 wt formula

where R is an alkyl hydrocarbon group having fewer than 9 carbon atoms and R _{1 is} a tertiary alkyl group having at least 4 and at most 12 carbon atoms. Such compounds can be prepared in an economical manner and show excellent results in the process of the invention.

The present invention is an improvement over the subjects of the French patent specification 2 158 292 and the Belgian patent 797 577 Al 58 - 5 -

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(ο

which relates to an improved antistatic fiber containing a new antistatic compound predominantly branched, chain-extended (long-chain) polymer with a melt viscosity of about 800 to 50,000 cp, preferably 1,500 to 25,000 cp, at 100.degree. The ethylene oxide content is preferably about 10 to about 90% by weight, based on the molecular weight of the tetrol compound. The molar ratio of the chain extending compound to the tetroi compound is preferably between about 0.7 and 1.0.

The phenolic compounds suitable for the process according to the invention are known compounds and are commercially available available. They can be prepared as described in US Pat. No. 2,818,945.

In the method according to the invention as an antistatic Chain-extended (long-chain) tetrol compound used as an additive is described in US Pat. No. 2,979,528.

The Tetro! Connections are commercially available under the name "Tetronic" as block copolymers with molecular weights of 1 65Ο to over 26,000 available. This group varies in terms of the lengths of the poly (oxyethylene) and poly (oxypropylene) chains. 3- and 4-digit key numbers indicate the molecular composition. If four digits are indicated, the first two digits mean the average molecular weight of the hydrophobic poly (oxypropylene) chains on the alkylenediamine. When three digits are given only the first number is intended for the stated purpose. The last digit of each key number means the percentage by weight of hydrophilic poly (oxyethylene) units.

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rounded to the nearest 10 #. The ones in the examples The tetroi compounds mentioned are explained in this way.

As diamines, the basis for the Tetro! Compounds Form, in addition to ethylenediamine, diamines of hydrocarbons with 1 to 13 carbon atoms, preferably the lower alkyl diamines in which the lower alkyl radical contains 1 to 6 carbon atoms are used.

The polyepoxy compounds can be prepared according to the method described in GB-PS 793,915 »Example 1 will. The other classes of compounds can point to similar ones ¥ be prepared as described in Example 10 of US Pat. No. 3,009,884.

Typical acids and their esters for the formation of the chain-extending, difunctional radicals are the dialkylphthal, isophthalic or terephthalic acid esters, for example dimethyl terephthalate, as well as the adipin, phthal, terephthal, sebacin, Glutaric, pimelic and isocinchomeronic acids, as well as the Esters of these acids.

Typical polyepoxy compounds that are used for chain extension of the diamines-based tetrol compounds required difunctional or divalent radicals deliver, those polyepoxy compounds are described in GB-PS 793 915 »in particular in page 2, ZIn.48 to 121 are.

According to Veiters, the aromatic or aliphatic diisocyanates with an OCN-R'-NCO group, in which R ^{1 has} the meaning given above, are advantageous for the formation of chain-extending divalent radicals.

The antistatic fibers or threads according to the invention can also contain conventional fiber additives such as antioxidants, stabilizers, Contain matting agents, coloring additives and dyes.

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The invention is explained in more detail in the following examples, but is not intended to be restricted thereto. the
The "parts" quoted mean parts by weight.

Example 1: This example describes a method for Preparation of a preferred antistatic additive of the type described in French Patent 2, .1-58 292 and Belgian patent 797 577. The present chain extended polymer is made from a tetrol compound which is covered by US Pat. No. 2,979 and is commercially available under the TETRONIC 1504 camouflage is.

300 g of TETRONIC 1504 (molecular weight 12,500) were placed in a three-necked flask equipped with a thermometer, a stirrer and a funnel. That
TETRONIC 1504 was stirred and heated to 100 ⁰ C, after which 5.24 g of 4,4'-methylene-bis- (eyclohexyl) isocyanate

- CE «CH ₀ - CH,

OClT - CH CH - CH ₀ - HC CH - NCO

\ / ² V /

CH ₂ - CH ₂ CH ₂ - CH ₂

(Molecular weight 262.4) was added dropwise to the material in the flask. Stirring was continued after completion of the addition for a further 1 hour at 100-105 ⁰ C. Then was

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the product cooled to room temperature; it was a soft solid with a melt viscosity of 8,300 cp at 100 ° C, measured with the Brookfield viscometer. The viscosity of the original TETRONIC 150 ** was 200 cp at 100 ° C.

Example 2: A glass reactor equipped with a heating device and a stirrer was charged with a mixture of 1,520 g of C-caprolactam and 80 g of aminocaproic acid. The mixture was then heated at 255 ° C. under a stream of nitrogen with stirring for 1 hour at atmospheric pressure to effect polymerization. Heating and stirring were continued at atmospheric pressure and under a nitrogen stream for an additional 1 hour to complete the polymerization. During the last 30 minutes of the polymerization, 1.7 8 4,4'-butylidene-bis- (6-tert-butyl-m-cresol) and 48 g of the antistatic compound from Example 1 were added to the polycaproamide and stirring was continued. to carefully mix the additives with the polymer. Nitrogen was then introduced into the glass reactor and a low pressure was maintained while the polymer was extruded from the glass reactor in the form of a polymer tape. The polymer tape was then cooled, chopped into spheres (pellets), washed and then dried. The polymer was a white solid with a relative viscosity of about 55 to 60 as determined on a solution having a concentration of 11 g of the polymer in 100 ml of a

90 # formic acid at 25 ° C (ASTMD-789-62T). Al 58 - 9 _

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The polycaproeunid beads containing the antistatic agent and the phenolic compound were ^{melted at about 285 °} C. and then melt-extruded under an overpressure of about 105 kg / cm through a multi-hole spinning nozzle with 16 openings, each of the openings having a diameter of 0.3556 mm , and a fiber of 250 denier was obtained. The fiber was then withdrawn at a speed of about 305 m / min and was drawn to about 3-5 times its extruded length to give a 70 denier yarn. Conveniently, this yarn is referred to herein as "Yarn A". A comparative yarn containing an antistatic compound but with no further addition was made in the same manner as previously described. Appropriately, this yarn is referred to herein as "yarn B ⁿ ".

A second comparison yarn which contained neither an antistatic compound nor a phenolic compound, was prepared in the same manner as previously described. Conveniently, this yarn is referred to herein as "Yarn C".

Yarn A, Yarn B and Yarn C were processed onto conventional fabrics. Sample sections each about 76 mm wide and about 228 mm long were cut from the fabrics. The fabric samples were tested for their antistatic properties, u.zw. in accordance with the general procedure described in the "Technical Manual of the American Association of Textile Chemists and Colorists", 1969 edition, Volume 45, pages 206-207 . This test specification is called "Electrostatic Clinging of Fabrics: Fabric to Metal Test ¹¹ and has the designation AATCC II5-1969. In this test, yarn C showed low antistatic properties, ie the average time it took for the sample section to fall off completely on its own after 5 to 25 washes for more than 300 seconds

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Both Yarn A and Yarn B exhibited excellent antistatic properties, i.e., the average time to the sample sections from the metal completely fell off by themselves, after 25 vials was about 120 seconds.

Yarn A, Yarn B and Yarn C were also, as shown in Example 3 below, for the number of knobs per kg Checked yarn.

Example 3: In this example, the procedure for finding, identifying and counting the knobs per kg is used in accordance with the example 2 produced yarns A, B and C are described.

With this method, a nub is defined as a thickened point in a filament or thread, which point a length of several thread diameters is not exceeded. This method can be used for both monofilament yarns and can also be used for multifilament yarns, however not applicable to most types of crimped yarn.

In this test, the 70 denier yarn is straight out peeled off the pack by means of air suction and passed through an opening of known width, in particular 0.076 mm in width. Such an opening is usually obtained by using a ceramic cleaning gap (cleaner gap), as is well known to the person skilled in the art. The presence of a nub is shown by the fact that it obstructs the passage of the Threads through the opening. The threads are separated and the cause of the standstill of the thread is identified as a nub or a tangled end of a broken thread. For representative results approximately 75 g Thread passed through the gap or opening and counted the number of knobs. The following Table I shows the Results of a test on yarn A, yarn B and yarn C.

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Table Ii Determination of the knobs per kg of yarn

Yarn sample Number of nubs per kg of yarn

Yarn A 7.716

Yarn B 39.352

Yarn C 5.070

It should be pointed out that polyamide yarns produced without additives have a relatively low nub count of 5070fing yarn. The addition of the antistatic compound to the polyamide caused the number of nubs to increase to 39,352 / kg of yarn. In contrast, the addition of the antistatic compound and also the phenolic compound, according to the invention, reduced the number of nubs to 7,716 "/ kg of yarn.

Example kl The procedure according to Example 2 (Yarn A) was carried out, with the exception that the various additives were initially treated with the caprolactam. The nub count of the antistatic fiber was only 7 055 / kg of yarn.

Example 5 1 The procedure of Example 2 (Yarn A) was carried out with the exception that the antistatic additive was treated with the caprolactam, but no phenolic compound was added. The antistatic fiber had a high number of knots of 36 817 / kg of yarn.

Example 6: The procedure according to Example 2 (yarn A) was carried out with the exception that the antistatic additive was prepared as a reaction product of TETRONIC 150k and dimethyl terephthalate in a molar ratio of 1: 0.7. The additive had a melt viscosity of 1,600 cp at 100 ° C.

60 g of the antistatic compound were added together with 1.13 g of 4,4'-butylidene-bis- (6-tert-amyl-m-cresol) and 6 _t k g

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rsi <

added to a 50 # aqueous dispersion of TiO _{3. The} nub count of the fiber was 6,967 / kg yarn.

Example 7t The procedure of Example 2 (Yarn A) was followed except that 90 g of the antistatic Compound according to Example 6 together with 1 g of 4,4'-heptylidenebis (6-tert-butyl-m-cresol) were used. The fiber produced had a low nub count of 7 15 ^ / kg of yarn.

Example 8: Polymer spheres (pellets) corresponding to Example 2 had been prepared and 90 g of the antistatic compound according to Example 1 together with 2.7 g of 4,4'-butylidene-bis- (6-tert-butyl-m-cresol) were melted at about 285 C and then under an overpressure of about 105 kg / cm through a multi-hole inner nozzle with 70 openings melt extruded, each of the openings having a diameter of 0.457, so that a fiber of about 4,500 denier was obtained. The fiber was moving at a speed withdrawn from about 305 m / min and became about 4 times their extruded hinge drawn to make about 1125 denier yarn.

This yarn is referred to herein as ⁿ Yarn D ". A comparative yarn containing neither an antistatic compound nor a phenol compound as an additive was prepared in the same manner as previously described. This yarn is referred to herein as" Yarn E ⁿ .

The yarns were textured using a steam jet and then doubled by twisting two ends with one another in the sense of a 1 1/2 S twist. The yarn was needled to a standard loop carpet (567 g), with a number of stitches of about 6.5 and a pile height of about 7 _t 2 to 7.9 mm, then dyed and provided with a layer of latex. The static charge on the carpet was determined by measuring the electrostatic charge (VoltJ

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determined on a person who walked over a piece of carpet with a series of steps, u.zw. according to the standard CRI-Valk test for static behavior (propensity) of carpets, according to AATCC 134-1969. The carpet was conditioned at 21 ^° C. and 20 ° relative humidity. The results are shown in the table below.

Carpet walk test

static charge

made with D 4.9 kV yarn

made with yarn E 14.1 kV

The untextured yarn was also checked for knobs, u.zw. using the knob counting method according to Example 3 »with the exception that the ceramic Rei inclination gap now had an opening width of 0.15. The number of pimples that of yarn D was 238 / kg while that of yarn E was 551 / kg.

Example 9: 94 parts of polyhexamethylene adipamide and 6 parts of the antistatic material of the structure according to Example 1 and 0.18 part of 4,4'-butylidene-bis- (6-tert-butyl-m-cresol) were melt blended by mixing the additive with the molten polyamide at about 285 C. The melt was extruded from a multi-hole spinning nozzle and the fibers were drawn off or drawn as described in Example 8. Carpet samples made from this fiber and tested according to Example 8 showed static electricity of 5f2 kV.

In further experiments it was determined that the molecular weight of the chain-extended for the production of a (long chain) antistatic compound used tetrol compound is preferably between about 4,000 and about 50,000 and that the ethylene oxide fractions about 10 # to about 90 #, based on the molecular weight of the compound mentioned.

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Preferably, the antfstatische fiber contains from about 2 to about 8 ° / o of the chain extended (long-chain) antistatic compound. Typically the extended chain (long chain) antistatic compound has a melt viscosity of 800 to 50,000 cp at 100 ° C. By an "antistatic ¹¹ fiber is meant a fiber that US-PS corresponds to the peel test and the Schlurftest according 3,657,386. The term" fiber "is a vielfaseriges yarn (multifilament), a monofilament (single yarn), and any known physical A "polyamide" is understood to mean polymers which are produced by the condensation of diamines with dibasic acids or by the polymerization of lactams or amino acids, whereby synthetic resinous products are formed which are characterized by the fact that they are recurring Grouping -CONH-contain.

An “ethylene oxide component” is to be understood as meaning a component in the chemical grouping - (CH ₀ CH _{0 O) -.}

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Claims (10)

Patent claims: 1. Method for producing an antistatic polyamide fiber from a fiber-forming polyamide polymer, which consists of about 1 to 12 wt .- $ of an antistatic compound, starting from a chain-extended reaction product of a tetrol compound of the general formula H (OCH-CH,) (OCHCHO. (CH CHO) _a (CH 2. ■ ^ y - ^ t. _s ^ CH, N-A-N CH * ι ³ \ where a _f b, c, d, w, x, y and ζ each denotes an integer and A denotes a difunctional radical of a hydrocarbon having 1 to 13 carbon atoms, the tetroi compound having a molecular weight between about 4,000 and about 50,000 , with at least one compound from the group of diepoxides and compounds which have the following divalent radicals: 0 0 I? Ii · ' ■ - .. _ -C-R'-C-, and '"■■" ■■ Π HH II ·. - ; -CN-R'-NC- ' form, wherein R ^{1 is} a difunctional radical of a hydrocarbon with 1 to 30 carbon atoms, by extruding the molten polymer through a nozzle into a quenching medium or precipitation medium and then stretching the resulting threads, characterized in that before extrusion in the to extruding mass at least about 0.5 wt .- $, based on the weight of the antistatic coating Al 58 - 16 - A09839 / 093H bond, a phenolic compound of the general form. R is an alkyl hydrocarbon group with fewer than '-> C atoms and R _{1 is} a tertiary alkyl group with at least M and at most 12 C atoms. 2. The method according to claim 1, characterized in that the ethylene oxide proportions about 10 to about $ 90, based on the molecular weight of the tetroi compound, and that the chain extended (long chain) antistatic compound has a melt viscosity of from about 800 to about 50,000 cps at 100 ° C. 3. The method according to claim 2, characterized in that the phenolic compound 4,4'-butylidene-bis- (6-tert.butylm-cresol) is used. 4. The method according to claim 2, characterized in that the phenol compound 4,4'-butylidene-bis- (6-tert.amylm-cresol) is used. 5. The method according to claim 2, characterized in that that the phenolic compound is 4,4'-heptylidene-bis- (6-tert-butylm-cresol) is used. 6. Antistatic polyamide fiber with less than 8.82 χ 10 knobs per kg fiber, which fiber about 1 to 12 Gew .- ^ contains an antistatic compound consisting of a chain-extended (long-chain) reaction product + from a tetroi compound of the general formula -.8th - 17 - 409839 / 093b CH, CH- ■ I " H (OCH ₂ CH ₂ ) _y (OCHCH ₂ ) _c ^^ li-A-N CH (CH ₂ CHO) _a (CH H (OCH ₂ CH ₂ ) (OCHCH ₂ ) (CII ₂ CHO) where a, b, c, d, w _f x _f y and ζ each denote an integer and A denotes a difunctional radical of a hydrocarbon having 1 to 13 carbon atoms, the tetrol compound having a molecular weight between about h, 000 and about 50,000 , and at least one compound from the group of diepoxides and compounds which have the following divalent radicals V 0 0. "Il K. • -C-R'-C-, and - 0 0 Il HHI! . - -CNR ¹ -NC- form, wherein R ¹ denotes a difunctional radical of a hydrocarbon with 1 to 30 carbon atoms, characterized in that they are at least about 0.5 wt .- $ _f based on the weight of the antistatic compound, a phenol compound of the general formula H. wherein R is an alkyl hydrocarbon group of less than - 18 - 9839 / 093b 9 carbon atoms and R _{1 is} a tertiary alkyl group with at least 4 and at most 12 carbon atoms. 7 · fiber according to claim 6, characterized in that the ethylene oxide fractions about 10 to about 90 96, based on the molecular weight of the tetroi compound, and that the chain extended (long chain) antistatic compound a melt viscosity of from about 800 to about 50,000 cp 100 ° C. 8. Fiber according to claim 7, characterized in that the phenolic compound 4,4'-butylidene-bis- (6-tert-butyl-mcresol) is. 9. Fiber according to claim 7 »characterized in that the phenolic compound 4,4'-butylidene-bis- (6-tert.amyl-mcresol) is. 10. Fiber according to claim 7, characterized in that the phenolic compound 4,4'-heptylidene-bis- (6-tert-butyl-mcresol) is. Al 58 - 19 - 40983 9/093 b