DE2213412A1 - PROCESS FOR THE PRODUCTION OF FABRICS, FIBERS AND FILMS FROM CHLORINE-CONTAINING COPOLYMERISATES OF ACRYLONITRILE - Google Patents

Description

FARBWERKE HOECHST AG. formerly Master Lucius & Brüning

File number: - HOE 72 / F 083

Date: March 17, 1972 - Dr. FK / GB

Process for the production of threads, fibers and foils
chlorine-containing copolymers of acrylonitrile

The invention relates to a process for the production of threads, fibers and films with an improved degree of Yfeißgrad from copolymers of acrylonitrile with vinyl and / or vinylidene chloride with 5 to 50 percent by weight of chlorine by adding cyanoethylated secondary or tertiary phosphines to the spinning solutions
these polymers.

The extraordinary sensitivity of the solutions of copolymers of acrylonitrile with vinyl and / or vinylidene chloride in organic solvents against the effects of heat, light and oxygen is a known problem in the processing and application of these polymers, due to their flame resistance and other preferred properties are of great technical interest. In the manufacture of threads, fibers and films, the copolymers mentioned are often exposed to elevated temperatures for a prolonged period in the dissolved state. The thermal The instability of these solutions is much more pronounced than with non-chlorine-containing copolymers of acrylonitrile and quickly leads to a yellow-brown to dark brown discoloration, which affects the products made from the solutions transmits.

It is considered certain that the mechanism of discoloration is different from that of pure polyacrylonitrile because the reaction starts at lower temperatures and because stabilizers that are successfully used in acrylonitrile copolymers with more than 80 percent by weight of acrylonitrile are generally ineffective . Likewise are the additives that the
Reduce the thermal sensitivity of polymers with a predominantly vinyl or vinylidene chloride content, both

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for example coprecipitated barium / cadmium soaps or organotin Compounds such as dibutyltin oxide or dioctyltin maleate, to stabilize copolymers of acrylonitrile with Vinyl and / or vinylidene chloride not suitable. Other stabilizers that help improve the thermal stability of the above chlorine-containing acrylonitrile copolymers have been proposed, e.g. B. zinc salts of organic and inorganic acids, cannot be satisfactory in their effectiveness. The use of the tertiary mentioned in British Patent Specification No. 855,484 Phosphines as stabilizers are greatly impaired by the fact that the more volatile representatives of this class of compounds, z. B. tributylphosphine, an unpleasant odor, great toxicity, easy flammability and mixed with air show a tendency to form explosive mixtures. The less volatile representatives of this class of compounds, e.g. B. triphenylphosphine, show a completely inadequate effectiveness. The alkylphosphines and especially the volatile compounds this class is hardly inferior in its toxicity to the extremely poisonous hydrogen phosphide (Ullmann, Encyclopadie of technical chemistry, Volume 13, page 581 f). The lethal concentration of phosphorus hydrogen for rats is given as 0.08 mg / l air (Spector, Handbook of Toxicology (1956), Saunders Company Philadelphia, London).

US Pat. No. 2,963,460 mentions bis (2-cyanoethyl) phosphine derivatives as plasticizers for acrylonitrile copolymers with a content of at least 60 percent by weight of acrylonitrile building blocks, which are present in amounts of at least 5 to over 100 % , based on the polymer, are to be used. In the production of threads, fibers and films from acrylonitrile copolymers, a content of plasticizers is undesirable, since this addition reduces the physical properties of the products produced.

It has also been proposed to use mixtures of a sulfonic acid and a reducing agent, such as. B. Tris- (2-cyanoethyl) phosphine, as a stabilizing agent for solutions of acrylic

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nitrile polymers that contain at least 80% acrylonitrile building blocks, to use.

It has now been found that the stabilization of the solutions of 'copolymers of acrylonitrile with vinyl and / or vinylidene chloride with a chlorine content of 5 to 50 percent by weight in an organic solvent simply by adding a cyanoethylated Phosphine of the following formula succeeds:

CH ₂ -CH ₂ -CN

RP RH, -CH ₂ -CH ₂ -CN or alkyl with

CH ₂ -CH ₂ -CN 1 to 10 carbon atoms

Suitable compounds of this type are, for. B. tris (2-cyanoethyl) phosphine, bis (2-cyanoethyl) phosphine. or mixtures of these compounds and the alkyl bis (2-cyanoethyl) phosphines. The compounds mentioned are easily accessible by cyanoethylation of the phosphine or by the reaction of bis (2-cyanoethyl) phosphine with alkenes (US Pat. No. 2,822,376 and German Pat. No. 1,078,574). The high boiling point enables these compounds to be handled easily and safely, especially since their toxicity is considerably lower than that of the above-mentioned phosphines. So z. B. the 50% lethal dose (LD ₅₀ ) in a mouse population for the tris (2-cyanoethyl) phosphine 2350 mg / kg body weight when administered orally, ie the compound can be described as very slightly toxic. During the processing of the spinning solutions, a larger part of this phosphine is converted into the corresponding phosphine oxide, which with an LD ₅₀ value of 15,000 mg / kg body weight (in mice) can be regarded as practically non-toxic. The use of the cyanoethylated phosphines according to the invention as stabilizers for spinning solutions is limited to amounts of 0.1 to 4%, preferably 0.5 to 3%, based on the polymer used. Particularly good stabilizing effects were observed with amounts of 0.7 to 1.5%, based on the polymer used. Additions of the cyanoäthyl ierten phosphines lead within the invention

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Quantity ranges have no plasticizing effects in the threads, fibers and films made from them. If the With a value of approx. 4% addition of cyanoethylated phosphines, a softening effect of the additives can be observed to an ever increasing extent which lead to an undesirable deterioration in the physical properties of the threads made from them, Fibers or foils leads.

In the case of copolymers of acrylonitrile with vinyl and / or vinylidene chloride cause the cyanoethylated phosphines mentioned in this patent an extraordinary stabilization against the discoloration the solutions of these copolymers in organic solvents in the heat, without the processing of the polymers in any Way to affect. In particular, the discoloration that occurs in water-based solvents is also suppressed occur very quickly, so that when using these stabilizers, moist solvents are also used for the preparation of polymer solutions can use, which is sometimes advantageous for influencing the coagulation speed during wet spinning.

The stabilizers can be added to the solvent prior to the addition of the polymer. The good solubility of the invention claimed stabilizers in the organic solvents suitable for the polymers, e.g. B. dimethylformamide, Acetonitrile or acetone makes the type of addition completely unproblematic. The most expedient seems to be the production of one concentrated stock solution, so that the desired amount of stabilizer is measured volumetrically and added to the solvent can.

The addition of p-toluenesulfonic acid surprisingly does not improve the effectiveness of the stabilizers mentioned. In contrast, with the non-chlorine-containing acrylonitrile copolymers with a content of over 80 % acrylonitrile, the addition of sulfonic acids at temperatures below 130 ° C leads to an additional improvement in the thermal stability of the spinning solutions and the whiteness of the threads, fibers and films made from them. 309839/0674

The effect of various stabilizers on the thermal stability of the polymer solutions can be tested for example by suitable polymers in dimethylformamide which is cooled to -10 ⁰ C and containing dissolved Stabxlxsatorzusätze the invention suspended. The polymer dissolves on warming to room temperature.

In the examples described below, solutions were prepared, each containing 25 percent by weight of the polymer, dissolved in dimethylformamide. These solutions were then heated to 100 ° C. in a thermostat for two hours and then judged for their discoloration by comparison with an arbitrarily set up color scale.

The scale of color numbers used for assessment is represented by the following extinction values for the specified Characterized layer thickness. The measurements were carried out using a DK-2 spectrophotometer from Beckman, Munich.

Color
number layer
thickness (cm) Extxnction at a
375 400 425 0.033 0.013 wavelength
450 475 --- from
500 (nm) 1 1.0 0.080 0.070 0.023 ■ _-.- 2 1.0 0.188 0.164 0.057 3 1.0 0.430 0.272 0.077 0.028 4th 1.0 0.678 0.230 0.070 0.033 5 0.5 0.590 0.245 0.083 0.030 0.025 6th 0.5 0.590 0.240 0.097 0.045 0.038 0.019 7th 0.5 0.602 0.275 0.113 0.057 0.052 0.028 8th 0.5 0.623 0.295 0.128 0.072 0.055 0.040 9 0.5 0.740 0.170 0.072 0.078 0.030 0.042 10 0.2 0.410 0.220 0.096 0.044 0.045 0.023 11 0.2 0.503 0.240 0.110 0.062 0.057 0.036 12th 0.2 0.520 0.235 0.120 0.075 0.068 0.047 13th 0.2 " 0.515 0.270 0.140 0.085 0.080 0.055 14th 0.2 0.534 0.290 0.173 0.103 0.107 0.068 15th 0.2 0.582 0.320 0.205 0.131 0.132 0.088 16 0.2 0.610 309839/0674 0.160 0.110

An estimate of the color number values is also possible by visual comparison with a number of color solutions, provided that one Pay attention to the same lighting and the same layer thickness.

Such a color scale can, for example, be made from aqueous solutions of potassium chromate p.a. and benzene light brown RL (manufacturer: Farbenfabriken Bayer AG.). Color solutions of the following composition are assigned to the color numbers (dissolved in distilled water):

Color number K ₂ CrO ₄ 1 0.0005 2 0.001 3 0.002 4th 0.003 5 0.005 6th 0.005 7th 0.005 8th 0.005 9 0.006 10 0.008 11 0.01 12th 0.01 13th 0.01 14th 0.01 15th 0.01 16 0.01

Benzene light brown RL -in dist. H ₂ O

0.0002
0.0005
0.0006
0.0008
0.0010
0.0015
0.0020
0.0025
0.0030 0.0040 0.0050

It It

dd dd

It

tt tt tt tt tt tt

It

tt tt tt tt

The copolymers of acrylonitrile and vinyl and / or vinylidene chloride listed in the examples were prepared by continuous suspension precipitation polymerization in an aqueous medium at 30 to 60 ° C., optionally under pressure, using the redox system potassium peroxydisulfate / sodium pyrosulfite / Mohr's salt as the catalyst became.

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Stabilxsatbr-

The following examples are intended to illustrate the effectiveness of the additives in the claimed spinning solutions. All Quantities in percent relate to percentages by weight.

example 1

25% solution of a copolyraeren made of 58% acrylonitrile and 42% Vinylidene chloride in dimethylformamide. The polymer had a chlorine content of 30.6% and a Fikentscher K value of 94.7 (definition see Cellulosechemie 13_, 58 (1932)). It became the The thermal stability of this copolymer in dimethylformamide was tested in the presence of the following additives:

additions Color numbers after 2
at 100 8th. at 25 ° greater 16 No 6th 11.5 0.5% bis (2-cyanoethyl) phosphine 6th 11 1.0% "" " 6th 11 1.5 % """ 6th 10.5 1.0 % "» ".
+ 0.25% TosH ^x; 5.0 15th 0.5% tris (2-cyanoethyl) phosphine 6th 12.5 1.0% " 8th 12.5 1.5 % "» » 9 12th 1.0% """χ
+ 0.25% TosH ^XJ 4.5 12th 1.0% n-hexyl ~ bis (2-cyanoethyl) -
phosphine 6th greater 16 20% water 9 14.5 20% water + 1.5% bis (2-cyanoethyl) -
phosphine 8 11.5 20% water + 1.5% tris (2-cyanoethyl) -
phosphine 10

TosH = p-toluenesulfonic acid

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Example 2

The effectiveness of the additives was tested on a spinning solution of a copolymer of 83% acrylonitrile and 17% vinylidene chloride. The chlorine content of the copolymer was 12.5% and the Fikentscher K value was 74.7.

additions Color numbers 25 ° 5 after 2 h
at 100 ° at 5 greater than 16 11 14th No 10, 5 12.5 0.5 ' 10, 12th 1.0 Ϊ 11 5 11.5 1.5? 10, 5 14.5 1.0 9 12th 12.5 0.5 <? 11 12th 1.0 9 11 11.5 1.5 9 10 12th ι, ο -) 11 1.0 9 ö bis (2-cyanoethyl) phosphine / it ü;: 1 if rt η f Il ii ti
+ · 0.25% TosH ^x ^ ο Tris- (2-cyanoätliyl) phosphine 'II'! ?! 1 It <■ 5 «
0 r tt -t SI
+ 0.25% TosH ^X) ο n-hexyl bis (2-cyanoethyl) -
phosphine

TosH = p-toluenesulfonic acid

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Example 3

The thermal stability of spinning solutions of a Co- was tested; polymer from 49% acrylonitrile and 51 % vinyl chloride; with a chlorine content of 29 % and a Fikentscher K value of 65.

additions

Color numbers after 2 h at 25 ° at 100 ° greater than 16 11 11.5 10.5 11 10.5 11 10.5 11 10 10.5 10.5 10.5 10.5 10.5 10.5 10.5 10 11.5 10.5

Il Il

It Il

No

0.5% bis (2-cyanoethyl) phosphine

1.0% "1.5%"

1.0% """ν + 0.25% TosH '

0.5% tris (2 ~ cyanoethyl) phosphine 1.0% ""
1.5% ""
1.0% "

Il Il

+ 0.25% TosH ^x)

1.0% n-hexyl bis (2-cyanoethyl) phosphine

x)

TosH = p-toluenesulfonic acid

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Example 4

Testing of the effectiveness of various additives to a spinning solution of a copolymer of 84% acrylonitrile, 10% vinylidene chloride and 5% methyl acrylate and 1 % methallyl sulfonate. The chlorine content of this copolymer was 7.3% and the Fikentscher K value was 84.5.

additions Color numbers after 2 h
at 100 ° at 25 ° greater than 16,
wine red No 6.0 10.5 0.5% bis (2-cyanoethyl) phosphine 7.0 10.5 1.0% "" 7.0 10.0 1.5 % " 7.5 9.5 1.0 % "» "ν
+ 0.25% TosH ^x; 6.0 10-11 0.5% tris (2-cyanoethyl) phosphine 10 10-11 1.5% " 9.5 10-11 1.0 % " ""· ν
+ 0.25 % TosH ' 8.0

TosH = p-toluenesulfonic acid

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Example 5

With the copolymer already described in Example 1), a number of spinning solutions were prepared in dimethylformamide and added for comparison with other, unclaimed phosphines. As in the previous examples it was the color number of these solutions is estimated after preparation and after storage at 100 ° C. for two hours.

additions • Color numbers after 2 h
at 100 ° 16 1.0% triphenylphosphine at 25 ° greater 16 1.5% "" approx. 9 _p
reddish greater 16 3.0 % "" approx. 9y
reddish greater 16 1.0% """^
+ 0.25% TosH ^J. approx. 9,
reddish greater 1.0% hydroxymethyl-bis- {2-eyano-
ethyl) phosphine 6th 15th 1.0% hydroxymethyl-bis- {2-cyano-
ethyl) phosphine + 0.5 % TosH ' ^$ IB
-CJ 14th 6.5

TosH = pr-toluenesulfonic acid

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Example 6

A 25% spinning solution in dimethylformamide was prepared from the copolymer described in Example 4) with the addition of 1.5% bis (2-cyanoethyl) phosphine, based on the polymer, as a stabilizer. The solution was ^{heated to 60 °} C., filtered at this temperature and degassed for 18 hours while maintaining this temperature. This spinning solution was spun through a 100-hole nozzle into a precipitation bath consisting of 65% dimethylformamide and 35 % water. The threads obtained were drawn by 300% in a subsequent water bath, washed free of solvent in further baths, after drying to a total draw of 500%, fixed at 150 ° C. and then prepared and wound up. The thread material was then shrunk without tension at 110 ° C. for 15 minutes. The whiteness of the threads spun in this way was characterized by the color values. The item emission measurements required for this were obtained with the Elrepho device (C. Zeiss, Oberkochen) according to the so-called three-range method by measuring with three special color measurement filters (FMX / C, FMY / C, FMZ / C), the reference system for the color values being the in the norm-valence system specified in DIN standard 5033 was used.

In the manner described above, further threads were produced from the same polymer, but they differed from the above Information contained no stabilizer in the spinning solution. The color values obtained are shown in the following table Comparison with indicated.

Sample titer color values dtex XY Z

Without stabilizer 483 f 100 60.0 56.4 44.4 (comparison)

With stabilizer 447 f 100 76.7 75.0 63.9

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Claims (6)

PATENT CLAIMS 1. Process for the production of threads, fibers and films from copolymers of acrylonitrile with vinyl chloride and / or Vinylidene chloride with a chlorine content of about 5 to 50 percent by weight, characterized in that the Spinning solutions of these polymers in organic solvents by adding 0.1 to 4.0 percent by weight, based on the polymer, at least one cyanoethylated phosphine of the following formula CH ₂ -CH ₂ -CN RP ^ R = -H, -CH ₂ -CH ₂ -CN or alkyl with CH ₂ -CH ₂ -CN 1 to 10 carbon atoms stabilized and from these solutions by known spinning processes Manufactures threads, fibers and foils. 2. The method according to claim 1), characterized in that the cyanoethylated phosphine is tris (2-cyanoethyl) phosphine used to stabilize the spinning solutions. 3. The method according to claim 1), characterized in that the bis (2-cyanoethyl) phosphine is used as the cyanoethylated phosphine used to stabilize the spinning solutions. 4. The method according to claim 1), characterized in that the cyanoethylated phosphine is n-hexyl-bis- (2-cyanoethyl) phosphine used to stabilize the spinning solutions. 5. The method according to claim 1), characterized in that there is a mixture of tris (2-cyanoethyl) phosphine as cyanoethylated phosphines and bis (2-cyanoethyl) phosphine used to stabilize the spinning solutions. 3 0 9 8 3 9 / Ö "6 7 4 6. The method according to claims 1) to 5), characterized in that that the cyanoethylated phosphines are added to the solvent before the addition of the polymer. 309839/0674