DE2305619A1 - PROCESS FOR THE MANUFACTURING OF FIBERS, FIBERS AND FILMS FROM POLYACRYLNITRILE AND MODACRYLNITRILE POLYMERS - Google Patents

Description

FARBWERKE HOECHST AKTIENGESELLSCHAFT
formerly Master Lucius & Brüning

File number: HOE 73 / F 035

Date: February 5, 1973 Dr. FK / Fk

"Process for the production of threads, fibers and films from polyacrylonitrile and modacrylonitrile polymers"

Addendum to patent ... (patent application P 22 13 411.8)

Subject of the main patent .... (patent application P 22 13 411 «8) is a process for the production of threads, fibers and films with improved whiteness from polyacrylonitrile and modacrylonitrile polymers by adding 0.05 to 4.0 percent by weight, based on the polymer, of at least one cyanoethyl-based phosphine the formula

CH ₂ - CH ₂ - CN

^ - CN

where R = H, -alkyl with 1 to 10 carbon atoms or -CHp-CH-CN

to the spinning solutions of these polymers. The known dipolar, aprotic solvents such as dimethylformamide or dime thylsulf oxide.

409833/0884 / ₂

HOE 73 / F 035

It has now been observed - this is what the present invention is concerned with - that the effectiveness of the stabilizers specified above is heavily dependent on the basic impurity content of the solvent. Particularly in the case of the hydrolyzable solvents, N, N-dimethylformamide and N, N-dimethylacetamide It is only possible with considerable technical effort to reduce the dimethylamine content in the recovered solvents to about 3 to h ppm or less when regenerating the spinning and ash baths For example, a dimethylformamide could be used, which has only been purified by a simple distillation and therefore still contains dimethylamine in large quantities.

It has now been found that the cyanoethylated phosphines mentioned even with a solvent content of over 100 ppm of dimethylamine can still be used as stabilizers, if in addition 0.01 to 0.1 percent by weight, based on the Polymers on trisoxymethylphosphine (hereinafter referred to as "TOMP" for short) can be added.

The use of TOMP as a stabilizer for acrylonitrile copolymers is known from JA-AS 37-17 ^ (reported in Chemical Abstracts, Vol. 59 (1963), column 6569) . However, technical use of this compound was hindered by its relative toxicity and the triggering of skin irritations. According to our measurements, the LD value of TOMP is 180 mg / kg body weight (determined on mice). Another disadvantage of this compound is the decomposition at temperatures above room temperature, one of the decomposition products being the highly toxic hydrogen phosphide.

It has now been found that trisoxymethylphosphine is already essential amounts smaller than the optimal 0.4 to 0.5 weight percent according to the Japanese application can be effective, if it is used together with a cyanoethylated phosphine according to the main patent. /

. 409833AO884 ^{/ J}

HOE 73 / F 035 - 3 -

With an addition of 0.01 to 0.1 percent by weight TOMP, the thermostabilization achieved is when solvents are used with basic impurities alone is not sufficient. The same applies to the sole addition of e.g. triscyanoethylphosphine in accordance with the main patent. A mixture of these two However, a noticeably less discoloration of the spinning solutions under the influence of temperature is observed than with the products Samples that only contained the individual components on their own »The synergistic effect is also evident from the following Examples can be seen.

In contrast, when the amounts of TOMP according to the invention are used in addition to the approximately 10 times as large quantities according to the Japanese registration, a hazard or nuisance to the operating personnel not given, even with a dry spinning process, the amount of hydrogen phosphide is through Decomposition so little that the maximum permissible workplace concentrations are never reached. By the influence of atmospheric oxygen in the aftertreatment of threads, fibers or TOMP residues are quantitatively oxidized to compounds that are practically non-toxic and none at all Produce skin irritation.

The examples described below are intended to further illustrate the invention. All quantities are, if not otherwise described, based on weight units.

409833 / Q884

HOE 73 / F 03

Examples;

¥ ie the parent application described in Example 1, the effectiveness of the various additives was as stabilizers at 28 followed by solutions of a copolymer of 93.5 parts of acrylonitrile, 5J8 parts methyl acrylate and 0.7 parts of sodium Methalylsulfonat tested in Diinethylformamid. Defined amounts of dimethylamine were added to the solvent in order to test the effectiveness of the stabilizers in the presence of this impurity.

Dimethylamine content in dimethylformamide

Additions based on Amount of polymer

Color numbers after thermal test for 60 min
80 ⁰ C

TRIS = tris (2-cyanoethyl) phosphine TOMP = tris (oxymethyl) phosphine

409833/0884

10 min at 135 ° C

1 0 ppm i 150 ppm without additive 10.5 11.5 0.1.9 ¹ o TRIS 9, o 10.5 0, 02 fo TOMP 10.5 Ί1, o 0.08 fo TRIS + 7, o 0.02 fo TOMP 300 ppm without additive 11.5- 12.0 0.1 fo TRIS 11.0 11.0 0.02 fo TOMP 10.5 11.0 0.08 fo TRIS + 10.0 10.0 0.02 fo TOMP without additive i4, o 14.0 . 0.1 fo TRIS 13.0 13.0 0.02 fo TOMP 12.0 13.0 0.08 fo TRIS + 11.0 11.0 0.02 fo TOMP

HOE 73 / F 035 - 5 -

The determination of the color numbers and the implementation of the thermal tests was carried out in accordance with the information in the main patent.

The dependence of the degree of whiteness of the formed structures produced on the color numbers of the spinning solutions used could be confirmed again in the case of test spinning.

/ 6 409833/0884

Claims (1)

HOE 73 / P 03 5 Claim: Process for the production of threads, fibers and foils Acrylonitrile and Modacrylhitrilpolmeren according to the method of the patent .... (patent application P 22 13 411.8), thereby characterized that the spinning solutions of these polymers in organic solvents by the addition of a) 0.05 to h weight percent, based on the polymer, of at least one cyanoethylated phosphine of the following formula: - CH ₂ - CN - CN CH ₂ CH ₂ RP R = -H, -alkyl with 1 to 10 carbon atoms or -CH ₂ - CH ₂ - CN and b) 0.01 to 0.1 percent by weight, based on the polymer, to Trxsoxymethylphosphxn stabilized and from these solutions by known Spinnver drive threads, fibers and films are made. 409833/0884