SU964032A1 - Method of producing modified fibre - Google Patents

Description

The invention relates to the chemical industry, in particular, to the technology of producing synthetic fibers, and three production of full-colored cryonitrile fiber can be used.

Polyacrylonitrile fiber "Nitron is obtained from a solution of a sololymer of nitrile of acrylic acid, methyl acrylate and itaconic acid in rhodane with sodium.

The solvent-extracted, freshly formed nitron fiber is non-uniform in structure both in length and in the width of the tow, which is confirmed by fluctuations in the pH of the fiber in the length and width of the tow from 4 to 8.5.

The heterogeneity of the fiber structure causes one to change the strength characteristics, such as the strength of the fiber on ipasipbie, and also causes the appearance of raznoton when dyeing the fiber with cationic dyes, especially noticeable when dyeing in dark tones.

A known method for producing modified polyacrylonitrile P-fiber by polyvial polymerization of an alkaline salt of Taconic acid at 50-230 ° C. 1. In addition to improving some consumer properties of the fiber, there is a tendency to shrink in hot water.

In addition, the process of graft polymerization on molded products is long, associated with the use of a large number of reagents, and requires special equipment.

The closest to the proposed method is a method of obtaining a modified fiber based on a copolymer of acrylic acid nitrile, methylate-chrylate

10 II itaconic acid by extracting freshly formed fiber, washing from solvent, processing with a modifying agent (formaldehyde in the presence of sulfuric acid) and drying 2.

15 Such a method is rather complicated in hardware design and connected with the use of reagents corroding equipment. In addition, the application of this method does not increase the susceptibility of the fiber to cationic dyes, which are the main dyes for nitron fiber; the strength and uniformity of color of the fibers is not high enough.

25 The purpose of the invention is to increase the strength of the fiber, dyeing, uniformity of color.

The goal is achieved by the fact that in a known production method (modified

30 nitrile copolymer based fibers

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of acrylic acid, methyl acrylate to itaconic acid by extracting overformed fiber, washing from solvent, treating with a modifying agent and drying as a modifying agent and using a 1.5-3% aqueous solution of an alkaline salt of itaconic acid and processing is carried out at 50-60 ° C within 1-2 seconds.

Claims (3)

Example 1. A bundle of freshly formed polyacryloitrile fiber "Nitron 1 m long after stretching and washing K1I from solution | Ittel is divided into 5 equal lengths and the fiber strength and pH are measured at each length. Then, a freshly packaged fiber tow, treated for 2 with 5% sodium itacont sodium solution at 50 ° C, 1 m long, is taken and also Hia 5 equal lengths are separated. Fiber strength and pH are measured at each section. Thus, the application of the proposed method of processing polyacrylonitrile fiber nitron allows one to increase the strength of the fiber while at the same time improving its dyeing with cationic dyes and the absence of different colors. Claim 30 A method for producing modified fiber based on a copolymer of nitrile acrylic acid, methyl acrylate and ifaconic acid by stretching 35 noth fiber, washed from the solvent. The results are shown in Table. one. Example 2. Everything, as in measure 1, but the harness is processed for 2 with a 5% solution of Itakonata Kaly. The results are shown in Table. one. Example 3. Four equal lengths of polyacrylonitrile fiber nitron for 2 seconds at 60 ° C are treated with a solution of sodium itaconate of different concentrations. Fifth such segment was left unprocessed. Then all 5 segments are dyed in a dye bath for 2 s in blue with a cationic dye “Blue-612. After dyeing, the strength of the fiber webs, pH and pCrNT are measured (the maximum difference in the light spore inside the face on the FKTSShM device). The results of pr: willow; 2 Table 2 by treatment with a modifying agent and drying, characterized in that, in order to increase the fiber density, dyeing, color uniformity, a 1.5-3% aqueous solution of an alkaline salt of itaconic acid is used as a multiplying agent and treatment is carried out at 50 -60 ° C for 1-2 seconds. Sources of information taken into account in the examination: 1. US patent number 4065256, cl. 8-115.5, pub. 1977. 2. The patent of Great Britain No. 1033141, cl. In 5 In, pub. 1966 (program).