PURPOSE: The title composition having improved mechanical properties, crack resistance, and moldability, without degrading the fluidity, comprising surface treated mica or its mixture with a filler.
CONSTITUTION: A composition comprising (A) a thermosetting resin, (B) 0.1W80 wt.%, preferably 1W50 wt.% of natural mica, e.g. phlogopite, or synthetic one, e.g. fluophlogopite, having a maximum particle size ≤10 mesh, preferably ≤100 mesh, prepared by immersing 100 parts by wt. of mica powder in a solution containing 0.1W50 parts by wt., preferably 1.0W10 parts by wt., of a surface treatment in water or an organic solvent, and by removing the water or solvent, or its mixture with another filler. A silane coupling agent, organic monocarboxylic acid, surfactant, or solicone resin, may be cited as the treatment.
YASUDA KAZUO
SHIBAYAMA KIYOUICHI
