Device and method for efficiently dissolving poly(p-phenytene terephthalamide) resin

Abstract

The invention discloses a device and a method for efficiently dissolving poly(p-phenytene terephthalamide) resin, belongs to the field of polymer material manufacture, and relates to a high-polymer fiber material processing technology, in particular to a technology for preparing a poly(p-phenytene terephthalamide) spinning solution. The key points are that: a preparation device is used and the method comprises the following steps of: preparing a solvent for dissolving poly(p-phenytene terephthalamide); adding the solvent and dried poly(p-phenytene terephthalamide) resin with logarithmic specific concentration viscosity of 4.0-8.5dl / g into a first twin-screen extruder; and tightening a second twin-screw extruder to obtain high-efficiency uniformly dissolved slurry. The invention has the advantages that: defects in the prior art are overcome, and a process and a device suitable for industrial continuous high-efficiency and high-quality production are realized.

Description

technical field [0001] The invention belongs to the field of polymer material manufacturing and relates to the processing technology of polymer fiber materials, specifically the technology of preparing poly(p-phenylene terephthalamide) spinning solution. Background technique [0002] Poly-p-phenylene terephthalamide fiber, commonly known as para-aramid fiber in my country, belongs to aromatic polyamide fiber. It is a fiber with high strength, high modulus, low specific gravity, chemical solvent resistance, high temperature resistance and flame retardancy High-performance materials are widely used in aerospace, military industry, electromechanical, construction, automobile, sporting goods and other fields. [0003] In the 1970s, my country began to develop poly-p-phenylene terephthalamide fibers, and made great progress, but there are still technical problems that high-viscosity poly-p-phenylene terephthalamide is difficult to dissolve and defoam. , the reason is that the poly...

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Problems solved by technology

[0003] In the 1970s, my country began to develop poly-p-phenylene terephthalamide fibers, and made great progress, but there are still technical problems that high-viscosity poly-p-phenylene terephthalamide is difficult to dissolve and defoam. , the reason is that the poly-p-phenylene terephthalamide / H2S04 solution system has a high viscosity and uneven stirring and mixing, resulting in uneven dissolution and incomplete defoaming. Furthermore, the solution system cannot stay for a long time, otherwise it will be easy Leading to the degradation of poly-p-phenylene terephthalamide during the dissolution process, it is impossible to meet the requirements of stable and continuous production. Many factors have led to the delay in the industrialization of poly-p-phenylene terephthalamide fiber in my country. one of the factors

[0004] Chinese patent CN101555631A discloses a method for dissolving poly-p-phenylene terephthalamide with solid sulfuric acid. The method uses 98-100.3% concentrated sulfuric acid at a temperature of -15°C to -5°C to make granular solids Sulfuric acid, and then mix it with poly-p-phenylene terephthalamide resin and dissolve it. The advantage of this method is that it solves the problem of metering concentrated and convenient sulfuric acid. High, the sulfuric acid in the system is unevenly distributed in the slurry, resulting in uneven dissolution and easy generation of gel particles, which still cannot solve the problem of uniform dissolution

[0005] Chinese patent CN1693543A discloses a method for continuously preparing poly-p-phenylene terephthalamide fibers. The method uses 98-100% concentrated sulfuric acid and poly-p-phenylene terephthalamide at a temperature of 50°C to 100°C. P-phenylenediamine resin is continuously added to two twin-screw extruders for dissolution. This method achieves the goal of continuous preparation, but the temperature is relatively high, and it is easy to dissolve in the mixture of concentrated sulfuric acid and poly-p-phenylene terephthalamide resin. Agglomeration occurs during the process, resulting in insufficient local dissolution and a "white core" phenomenon. At the same time, due to the limited dehydration ability of the 98-100% concentrated sulfuric acid used, it is impossible to completely remove the interpolymers in poly-p-phenylene terephthalamide. Moisture, so there is still degradation during dissolution

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