Preparation method of nano-silica reinforced meta-aramid paper

Abstract

The invention discloses a preparation method of nano-silica reinforced meta-aramid paper. The preparation method comprises the steps of treating meta-aramid chopped fiber by using an aqueous solution of a surfactant, and then, mixing the treated meta-aramid chopped fiber and meta-aramid pulp according to a certain proportion to prepare aramid fiber pulp; then, adding nano-silica subjected to ultrasonic treatment into paper pulp to obtain a mixed suspension liquid; dehydrating the mixed suspension liquid, forming, wetly squeezing the formed product, and drying to obtain raw aramid paper; carrying out hot pressing on the raw aramid paper by using a hot press to obtain the meta-aramid paper. According to the invention, nano-silica is added in the preparation process of the aramid paper, so that the tensile strength and compressive strength of the meta-aramid paper are improved.

Description

technical field [0001] The invention relates to the field of papermaking, in particular to a method for preparing nano-silica reinforced meta-aramid paper. Background technique [0002] Due to its special paper structure and excellent mechanical, chemical, electrical and physical properties, meta-aramid paper has become a revolutionary new material, and it has been rapidly popularized and applied in military, communication, transportation, electrical and other fields. very broad. Meta-aramid paper is recognized worldwide as a high-quality insulation material. Its temperature-resistant insulation grade is Class C (220°C), and it can still maintain good electrical and mechanical properties in a high-temperature environment exceeding 200°C, enabling electromechanical products to reach Class F (155°C) and Class H (180°C). High temperature insulation grade; the breakdown voltage is higher than 20 kV / mm, and has excellent dielectric strength; it does not deform or melt under hig...

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Problems solved by technology

[0007] The Chinese invention patent with the patent publication number of 102899959 proposes "a para-aramid paper for honeycomb materials and its preparation method". Tear strength, high temperature resistance and flame retardancy, etc. However, due to the difference in performance between polyimide fiber and aramid fiber, how to choose the appropriate hot pressing temperature in the preparation process is a problem to be solved

[0008] The Chinese patent with the patent publication number 102154914A discloses "a method for making additive-type meta-aramid paper", which mainly strengthens the inter-layer by adding functional powder in the process of manufacturing meta-aramid pulp-like fibers. One aspect of the performance of aramid paper or additional performance, but whether the performance of aramid pulp can be improved after adding functional powder remains to be verified

[0009] The Chinese invention patent with the patent publication number of 1932148 proposes a kind of "aramid paper with aramid chopped fiber as raw material and its preparation method". 10%~90% of fiber analysis, 0%~60% of polyester chopped fiber, and 0%~50% of mica to prepare a synthetic aramid paper. Polyester chopped fiber is used as a bonding fiber to make the fiber However, due to the thermal shrinkage of the polyester fiber under hot pressing conditions, gaps or pinholes are formed in the position of the original polyester fiber in the paper due to the shrinkage, thereby increasing the porosity of the paper and affecting the insulation performance of the paper.

The strength of the aramid paper prepared by the above two methods is higher than that of the aramid base paper without impregnation treatment, but during the impregnation process, the absorption of the base paper to the polyimide solution is difficult to control, and the impregnated paper will be hot-pressed become brittle, resulting in a loss of strength

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