Unlock instant, AI-driven research and patent intelligence for your innovation.

Defoaming method of carbon fiber spinning dope

A carbon fiber and defoaming technology, used in fiber processing, filament forming processing, textiles and papermaking, etc., can solve the problem of difficult removal of air bubbles, and achieve the effect of inhibiting decomposition reaction, good technical effect, and transparent color.

Active Publication Date: 2016-04-13
CHINA PETROLEUM & CHEM CORP +1
View PDF8 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The technical problem to be solved by the present invention is that in the prior art, when removing air bubbles in the polyacrylonitrile spinning dope for carbon fibers, the air bubbles formed by the rapid gasification of acrylonitrile due to the continuous deaeration of high vacuum are not easy to be removed. Eliminate, as well as the problem that the solvent is easily taken out together, provide a new method for degassing carbon fiber spinning dope

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] Through solution polymerization, in the stock solution obtained by copolymerization of acrylonitrile and itaconic acid, the weight ratio of acrylonitrile monomer / copolymer / DMSO is 3% / 17% / 80%, and the initiator used in the polymerization process is azobis Isobutyronitrile, the polymerization reaction temperature is 60°C, and the polymerization tank is 5L. After the reaction is finished, vacuumize and remove the singles, and the content of acrylonitrile after the singles is removed is 1500ppm. The spinning dope after de-singing is subjected to defoaming treatment, first vacuumed for 10 minutes, the pressure is -0.1MPa, and then nitrogen gas is introduced until the pressure is 0.03MPa, the nitrogen purity is 99.999% and the temperature is 55°C. After standing still for 20 hours, test the bubble content of the stock solution, the number of bubbles shown under the microscope is 3, and there is no loss of solvent.

Embodiment 2

[0019] Through solution polymerization, in the stock solution obtained by copolymerization of acrylonitrile and methyl acrylate, the weight ratio of acrylonitrile monomer / copolymer / NaSCN aqueous solution is 10% / 20% / 70%, and the initiator used in the polymerization process is azo Diisobutyronitrile, the polymerization reaction temperature is 80°C, and the polymerization tank is 5L. After the reaction is finished, vacuumize and remove the singles. After the singles are removed, the acrylonitrile content is 2000ppm. The spinning dope after de-singing is subjected to defoaming treatment, first vacuumed for 30 minutes, the pressure is -0.06MPa, and then nitrogen gas is introduced until the pressure is 0.01MPa, the nitrogen purity is 99% and the temperature is 75°C. After standing still for 28 hours, the bubble content of the stock solution was tested, and observation under the microscope showed that the number of bubbles was 0, and there was no loss of solvent.

Embodiment 3

[0023] Through solution polymerization, in the stock solution obtained by copolymerization of acrylonitrile, itaconic acid and methyl acrylate, the weight ratio of acrylonitrile monomer / copolymer / DMSO is 8% / 18% / 74%, and the initiator used in the polymerization process It is azobisisoheptanonitrile, the polymerization reaction temperature is 45°C, and the polymerization tank is 5L. After the reaction is finished, vacuumize and remove the singles. After the singles are removed, the acrylonitrile content is 1000ppm. The spinning dope after de-singling is subjected to defoaming treatment, first vacuumed for 60 minutes, the pressure is -0.08MPa, and then argon gas is introduced until the pressure is 0.15MPa, the purity of the argon gas is 97% and the temperature is 40°C. After standing still for 28 hours, the bubble content of the stock solution was tested, and observation under the microscope showed that the number of bubbles was 2, and there was no loss of solvent.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention relates to a de-bubbling method of a polyacrylonitrile spinning solution for carbon fibers, and mainly solves the problems that in the prior art, when bubbles in the polyacrylonitrile spinning solution for the carbon fibers are removed, due to a method of high-vacuum continuous de-bubbling, the bubbles caused by quick gasification of acrylonitrile are difficult to remove and solvent is prone to being brought out together with the bubbles during de-bubbling. The method includes a, placing a mixture obtained by polymerization of an acrylonitrile solution after denitriding into a container, and vacuumizing the container to be at negative pressure; b, injecting gas inactive with the solution into the container to enable pressure in the container to be normal pressure or positive pressure, and standing for de-bubbling until the number of bubbles in the test solution is smaller than 3. The carbon fiber spinning solution de-bubbling method can be used in industrial production, especially in bubble removing in the process of PAN-based carbon fiber precursor spinning.

Description

technical field [0001] The invention relates to a method for defoaming carbon fiber spinning dope. Background technique [0002] Carbon fiber can be obtained by carbonization of polyacrylonitrile fiber, pitch fiber, viscose or phenolic fiber, among which polyacrylonitrile (PAN)-based carbon fiber is the most widely used, the largest amount, the fastest growing, and occupies an absolute position in carbon fiber production. Advantage. In the preparation process of PAN-based carbon fiber precursor, like most other man-made fibers, the removal of air bubbles in the spinning solution is involved. [0003] The solution will generate bubbles during polymerization or transportation; on the other hand, since the polymerization uses azo compounds as initiators, the nitrogen generated during decomposition is also mixed in the original solution to form bubbles. The polyacrylonitrile stock solution used for carbon fiber spinning has a relatively high viscosity, and these bubbles are no...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): D01D1/10
Inventor 崔晶沈志刚王贺团史纪友
Owner CHINA PETROLEUM & CHEM CORP