DE1054656B - Process for the production of threads or fibers from polyacrylonitrile and / or its copolymers with good fiber properties - Google Patents

Description

The invention relates to a method for producing fibers or threads based on polyacrylonitrile with good dyeing behavior either towards acetate dyes or basic dyes and acidic dyes, which are used after the dyeing process with monovalent copper ion.

It is known that, in general, polyacrylonitrile fibers have a low absorption capacity for dyes and that various proposals have been made to increase this capacity.

It is also known that the usual methods usually lead to the formation of fibers that are not too are afflicted with underestimating disadvantages, e.g. B. low heat resistance, insufficient serimetric Properties, poor color fastness, etc.

It has been found that when in the polyacrylonitrile or its copolymers, sufficient amounts Starch cyano ethyl ether, which is insoluble in water, but in organic solvents, such as in dimethylformamide, are to be incorporated, it is possible to obtain fibers that can easily be with either Acetate dyes or with basic or acidic dyes using the copper (I) ion method permit. Starch cyano ethyl ether of the formula

RO CH ₂ -CH ₂ C N-

in which R is a starch radical, are known to be compounds formed by reaction between starch and Acrylonitrile can be obtained.

The inventive method consists essentially in that polyacrylonitrile and relatively small amounts of starch cyanoethyl ether in dimethylformamide or in such organic solvents be solved, which can dissolve both the polyacrylonitrile and the starch cyanoethyl ether, and the Solution is then spun.

In the practical application of the new process it was found that the best results achieved with 10 parts by weight of water-insoluble starch cyanoethyl ether and 90 parts by weight of polyacrylonitrile will. With smaller weight ratios: starch cyanoethyl ethers give insignificant results achieved.

The new process achieves a number of advantages, such as

1. the chromatic stabilization of the spinning solution, even with prolonged exposure to heat,

Method of making threads
or polyacrylonitrile fibers
and / or its copolymers with good coloring properties

Applicant:
Montecatini, Societä Generale
per rindustria Mineraria e Chimica,
Milan (Italy)

Representative:

Dipl.-Ing. Dipl.-Chem. Dr. phil. Dr. techn. J. Reitstötter, patent attorney,
Munich 15, Haydnstr. 5

Claimed priority:
Italy from February 15, 1956

Domenica Maragliano and Enrico Cernia,
Milan (Italy),
have been named as inventors

2. a better spinning ability of the spinning solution,

3. Easier stretchability of the threads, the serimetric properties of which are quite satisfactory are.

4. less embrittlement of the

Fibers or threads compared to other methods.

example

IOkg of a water-insoluble starch cyano ethyl ether become 400 ^! kg of dimethylformamide dissolved at 40 to 60 ° C. After cooling, 90 kg of polyacrylonitrile (molecular weight 73,000) and 400 g of matting titanium dioxide are dispersed in this solution. This dispersion is conveyed through a dissolving device with a tube bundle heat exchanger, where it is transformed into a spinning solution at 100 to 120 ° C, which is then spun dry at 80 ° C.

The threads obtained in this way are then at 150 to 180 ° C in a steam atmosphere (draw ratio 1: 5) stretched, treated with hot water, mechanically puckered, im Autoclave steamed at 100 to 105 ° C, sized,

809 789/489 '

Claims (1)

cut and dried. The mechanical characteristics of these fibers are: Strength 3.17 g / deh . Elongation 22.0% Shrinkage at 100 ° C ......... 3 to 4% After repeated bending in technical bending test devices, these fibers failed after 5 to 6 minutes, while other known polyacrylonitrile fibers in the same bending test after 15 to 20 seconds broke T: The fibers thus obtained were experimentally dyed. - - 20 g of staple fibers were placed in a 55- to 60-degree dye bath containing 1 g of malachite green (Schultz dye table no. 754) Krist. contained in 400ecm of water. The bath was brought to boiling temperature and the dyeing was continued at the boil for 1 to IV2 hours. Then 3 g / l of a soaping agent, which is a sulfonation product of higher fatty alcohols, was soaped for 20 minutes and then rinsed. The fibers had turned an intense green. The fastness properties of the dye, according to the international norms for the fastness properties assessed, resulted in: Fastness to light (natural light) ... 6 to 7 Fastness to washing, damp, bed 70 ° C 5 : Fastness to washing, dry (tridhlorethylene) 5 Fastness to perspiration 5 Rubbing fastness 5 "'When dyeing under the above working conditions with 5% Setylvierlett B" Color Index "(2nd edition No. 62 030 a deeply colored fiber material with the following fastness properties is obtained: Light fastness (natural exposure) .... Fastness to washing, damp, at 70 ° C Fastness to washing, dry (trichlorethylene) Fastness to perspiration Rubbishness 15 "The serimetric properties are not affected by the dyeing process. Claim, - Process for the production of threads or fibers from polyacrylonitrile and / or its copolymers with good coloring properties, characterized in that a solution can be used becomes ,, besides polyacrylonitrile and / or its copolymers, starch cyanoethyl ether which is insoluble in water but soluble in organic solvents.