▎ 摘　　要

NOVELTY - High surface tear strength mica piece comprises a mica piece main body is prepared by silicone resin and mica slurry. The mica slurry comprises 100 pts. wt. mica powder composition, 2-8 pts. wt. reinforcing filler and 80-120 pts. wt. organic solvent. The reinforcing filler comprises modified Kevlar (Para-aramid synthetic fiber) fiber vertically distributed in the mica main body composed of Kevlar (Para-aramid synthetic fiber) and modified coating coated on outer wall of Kevlar (Para-aramid synthetic fiber) . The specification of the Kevlar (Para-aramid synthetic fiber) fiber is 100-300D and length is 0.1-1 mm. The modified coating is prepared by modified coating comprising 20-25 wt.% aqueous polyurethane, 2-5 wt.% non-ionic dispersant, 0.5-3 wt.% non-silicone mineral oil de-foaming agent, 2-5 wt.% silicone substrate wetting agent, 1-3 wt.% propylene glycol phenyl ether, 0.5-2 wt.% pH regulator, 20-40 wt.% de-ionized water and 5-25 wt.% toughening filler. USE - Used as high surface tear strength mica piece. ADVANTAGE - The high surface tear strength mica piece: does not damage surface of mica products during tearing the release paper on the double-sided tape; and improves the quality of mica products. DETAILED DESCRIPTION - High surface tear strength mica piece comprises a mica piece main body is prepared by silicone resin and mica slurry. The mica slurry comprises 100 pts. wt. mica powder composition, 2-8 pts. wt. reinforcing filler and 80-120 pts. wt. organic solvent. The reinforcing filler comprises modified Kevlar (Para-aramid synthetic fiber) fiber vertically distributed in the mica main body composed of Kevlar (Para-aramid synthetic fiber) fiber and modified coating coated on the outer wall of Kevlar (Para-aramid synthetic fiber) fiber. The specification of the Kevlar (Para-aramid synthetic fiber) fiber is 100-300D and length is 0.1-1 mm. The modified coating is prepared by modified coating comprising 20-25 wt.% aqueous polyurethane, 2-5 wt.% non-ionic dispersant, 0.5-3 wt.% non-silicone mineral oil de-foaming agent, 2-5 wt.% silicone substrate wetting agent, 1-3 wt.% propylene glycol phenyl ether, 0.5-2 wt.% pH regulator, 20-40 wt.% de-ionized water and 5-25 wt.% toughening filler. The toughening filler comprises graphene. The preparation method of modified Kevlar (Para-aramid synthetic fiber) fiber comprises (a) adding Kevlar (Para-aramid synthetic fiber) fiber into 3-8% ethanol aqueous solution, carrying out conduct ultrasonic treatment for 200-400 seconds, washing with water, and drying; (b) performing plasma surface treatment to the Kevlar (Para-aramid synthetic fiber) fiber at 0-15degrees Celsius, the gas medium is oxygen for 10-15 minutes; and (c) preparing modified coating, spraying the modified coating on the outer wall of Kevlar (Para-aramid synthetic fiber) fiber, curing at 60-75degrees CelsiusC to form modified coating on the outer wall of Kevlar (Para-aramid synthetic fiber) fiber to obtain modified Kevlar (Para-aramid synthetic fiber) fiber. An INDEPENDENT CLAIM is also included for forming high surface tear strength mica piece, comprising (i) adding the mica powder composition into a 2-5 g/liter mica surfactant aqueous solution, and performing ultrasonic treatment for 5-10 minutes to obtain a modified mica mixture; (ii) mixing the modified mica mixture, the reinforcing filler and the organic solvent evenly mixed, adding the silicone resin into the material, and stirring to obtain the mica slurry; (iii) injecting the mica slurry into the forming mold, placing the forming mold between the two plates of the capacitor, the electric field direction of the capacitor is the same direction as the height of the mold for 30-60 minutes, and heating the mold during the placing process to remove the organic solvent in the mica slurry; and (iv) taking out the mold and hot pressing to form a mica product.