Method of continuously preparing poly terephthaloyl-p-phenylene diamine fibre

Abstract

The invention discloses a method for continuously preparing p-phenylene terephthalamide (PPTA) fiber, including the steps of: (1) continuously adding 98-100% oil of vitriol and PPTA with specific logarithmic viscosity of 4.0-8.5 dl / g to an double spiral extruder, where the weight percent of PPTA is 14-24% and the mixing temperature is 50-100 deg.C; (2) fully mixing and entering in the other extruder, where the adjusting temperature is 50-100 deg.C and the staying time is 10-60 min, fully mixing, adjusting temperature and defoaming and then extruding them; (3) after measuring and filtering spinning solution, obtaining the invention by the routine steps, such as dry spraying-wet spinning. The advantages are short time for mixing materials, adjusting temperature and defoaming high mixing uniformity of materials able to implement continuous, stable filature in a short time, raising the production efficiency.

Description

technical field [0001] The invention relates to a method for preparing fibers, in particular to a method for continuously preparing poly(p-phenylene terephthalamide) fibers. Background technique [0002] As we all know, poly-p-phenylene terephthalamide fiber is a typical aromatic polyamide fiber, also known as aramid 1414 or PPTA fiber, which has excellent properties such as high strength, high modulus, and high temperature resistance. The fastest-growing high-tech fiber in fiber materials is mainly used in industrial textiles, especially in the occasions where many products require lightweight and high performance, only polyparaphenylene terephthalamide (PPTA) can be used. )fiber. [0003] In the early 1970s, Yumi was DuPont who first invented PPTA / H 2 SO 4 The method of dry spraying-wet spinning of liquid crystal solution has produced this kind of high-strength and high-modulus PPTA fiber, but there are still PPTA / H 2 SO 4 In the preparation process of the spinning li...

AI Technical Summary

Problems solved by technology

[0003] In the early 1970s, Yumi was DuPont who first invented PPTA / H 2 SO 4 The method of dry spraying-wet spinning of liquid crystal solution has produced this kind of high-strength and high-modulus PPTA fiber, but there are still PPTA / H 2 SO 4 In the preparation process of the spinning liquid crystal solution, the stirring and defoaming of the high-viscosity solution are difficult technical problems. Usually, the PPTA resin is dissolved in 99-100% sulfuric acid at 80-90°C, and it takes at least 3 hours, while PPTA / H 2 SO 4 The defoaming of spinning liquid crystal solution often takes longer time, up to tens of hours to dozens of hours, which is not only unfavorable for continuous industrial production, but also PPTA is prone to degradation during the long-term dissolution and defoaming process, thus affecting Strength of PPTA fiber

[0004] Chinese invention patent 200310109240 discloses a semi-continuous method for preparing poly(p-phenylene terephthalamide) fibers, adding poly(p-phenylene terephthalamide) resin and concentrated sulfuric acid into a mixing cylinder and mixing them with twin-screw The extruder solves the problems of long dissolving time of poly-p-phenylene terephthalamide resin in concentrated sulfuric acid and difficult defoaming of spinning solution, but for industrial production, there are still difficulties in stirring during the mixing process and Difficult to mix evenly