SU1081246A1 - Polyacrylonitrile fibre - Google Patents

Abstract

METHOD FOR PREPARING POLYACRYLONITRILE FIBER by preparing a solution (.for fiber spinning) by copolymerizing acrylonitrile with methyl acrylate and itaconic acid in 51-52% aqueous 6% sodium rohanide solution with a monomer: solvent ratio of 1: 3.0-3.5 and 84-86% of sodium rohanide solution: monomer: solvent ratio 1: 3.0-3.5 and 84-86% of sodium rohanide solution: monomer: solvent ratio 1: 3.0-3.5 and 84-86% sodium rohanide solution: monomer: solvent ratio 1: 3.0-3.5 and 84-86% sodium rohanide solution: monomer: solvent ratio 1: 3.0-3.5 and 84-86% sodium rohanide solution: monomer: solvent ratio 1: 3.0-3.5 and 84-86 ° solution of sodium rohanide sodium: 1: 3.0-3.5 and 84-86 &rat;; C, by forming into a water-ordeal precipitation bath, drawing, washing and drying, characterized in that, in order to increase strength, reduce the formation of scree, and vinylacetate is additionally introduced to the reaction mass in the following ratio Yenia monomers, mA.%: Acrylonitrile 92.7-92.8 Metalacrylate 4.0-4.5 Itononic acid1.2-1.3 Vinyl acetate1.5-2.0

Description

The invention relates to a technology for producing synthetic fibers, in particular modified polyacrylonitrile fibers.

There is a known method for producing polyacrylonitrile fiber by preparing a solution for forming the fiber by copolymerization of acrylonitrile, with methyl acrylate and itaconic acid in a 51-52% aqueous solution of sodium thiocyanate with a ratio of monomer: solvent of 1: 2.9-3.1 and 84-86 ° C, molding in a water-rhodanide precipitation bath, drawing, washing and drying [1).

re at 85 ° C and with stirring: get a solution of the polymer in sodium thiocyanate. After separation of the unreacted monomers and dehydration, the solution is cleaned with solid particles on a filter press and fed to a die.

Thin trickles of polymer emerging from the die are coagulated in a precipitation bath (12% aqueous solution of sodium thiocyanate). The fiber is pulled, washed with solvent, and dried.

The fiber has the following physical and mechanical properties:

In doing so, use the following fifteen Single strength monomer composition, wt.%: fiber, HS / Tex 27.5 Acrylonitrile 92.7 Fiber strength Methyl acrylate 6.0 in loop, GS / tex 9.6 Taconic acid 1.3 Elongation,% 34.7 However, the fiber obtained 20. Shrinkage,. % 5,4 according to this method, low strength Scree content,% 0,03 single fiber (<27 Gs / tex), Example 2, Monomers in low loop strength (<7 Gs / tex) shenii, wt.%: and textile processing of this Acrylonitrile 92.8 a large amount of fiber is formed 25 Methyl acrylate 4,5 in a talus of 0.1-0.2%. Vinyl acetate 1,5 The purpose of the invention is to improve Taconic acid 1,2

reduction of the formation of scree in the corresponding solvent (51.5% aqueous

The goal is achieved in that according to the method for producing polyacrylonitrile fiber by preparing a solution (for forming the fiber) by copolymerizing acrylonitrile with methyl acrylate and itaconic acid in a 51-52% aqueous solution of sodium thiocyanate at a ratio of monomer: solvent of 1: 3.0-3.5 and 84-86 ° С, by molding in a water-rhodanide precipitation bath, by drawing, washing and drying, vinylac is additionally introduced into the reaction mass during the copolymerization. Tat in the following ratio of monomers, wt.%:

Acrylonitrile 'Methyl Acrylate

Taconic acid

Vinyl Acetate Example, Wearing, May.%:

Acrylonitrile Methyl Acrylate Vinyl Acetate

Thactonic acid 1.3 and the solvent — sodium thiocyanate (51.5% aqueous solution) in the ratio solvent: monomers 3: 1 at 25 ° C are fed by a metering device to the mixer, from where the reaction mixture is sent to the polymerization pump. In polymerizato30 and a solution of sodium thiocyanate) at a monomer: solvent ratio of 1: 3.5, it is fed to the mixer and polymerization agent under the conditions of Example 1. The technology for producing fiber is fully consistent with the technology of Example 1. The fiber has the following parameters: Single fiber strength, G / tex Fiber strength in a loop, G / tex Elongation,% Shrinkage,% Scree content,%

Example 3 (comparative).

Get fiber Nitron, using, wt.%: Acrylonitrile 92.7, methyl acrylate 6.0, itaconic acid 1.3. The technology for producing fiber corresponds to example 1. Fiber blowing indicators:

Single fiber strength, G / tex Fiber strength, G / tex Elongation,% Shrinkage,% Scree content,%

Thus, according to the proposed method receive polyacrylonitrile fiber, the strength of which increases by 10-15%, the strength of talus

31,2

10.2

40.1

6.7

0.01

92.7-92.8

4.0-4.5

1.2-1.3

1.5-2.0

1. Monomers respectively

92.7 4.0 2.0

VNIIIPI Order 1485/24 has the following

6.1 31.6

6.3

0.2 in the loop by 20-25%, the amount decreases by 7-20 times.

Circulation

441

Subscription

Branch of the PPP Patent, Uzhgorod, Project 4,

Claims (1)

METHOD FOR PRODUCING POLYACRYLONITRILE FIBER by preparing a solution (for forming the fiber) by copolymerizing acrylonitrile with methyl acrylate and itaconic acid in a 51-52% -ndn sodium thiocyanate aqueous solution at a ratio of monomer: solvent of 1: 3.0-3.5 and 84-86 ° С, molding into a water-rhodanide precipitation bath, drawing, washing and drying, characterized in that, in order to increase strength, reduce the formation of scree, and the reaction mass in the process of copolymerization is additionally introduced vip * nilacetate in the following ratio of mono measures, May.%: Acrylonitrile Metal acrylate Taconic acid Vinyl acetate 92.7-92.8 4.0-4.5 1.2-1.3 1.5-2.0