Heat-resistant prepreg and method for production thereof
AssigneeShowa Electric Wire & Cable Co., Ltd.
InventorsEtsuo Hosokawa, Hiroshi Hashimoto
Life of this patent
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Abstract
A heat-resistant prepreg uses at a substrate a heat-resistant material made of heat-resistant organic fibers, inorganic fibers, etc. and as a matrix a heat-resistant mixture containing at least 10% by weight of a borosiloxane resin composition. This heat-resistant prepreg is obtained by impregnating the substrate at a temperature in the range of 200.degree. to 300.degree. C. to such an extent that at least 20% of the amount of phenyl groups bonded to silicon atoms in the aforementioned borosiloxane resin composition prior to the impregnating and drying steps will remain after the heat treatment.
Claims6
A heat-resistant prepreg comprising a heat-resistant substrate impregnated with a heat-resistant mixture, the heat-resistant mixture comprising at least 10% by weight of a borosiloxane resin composition and a heat-resistant resin in an amount to make up 100% by weight, at least 20% of the amount of phenyl groups bonded to silicon atoms in said borosiloxane resin composition prior to impregnating and drying being still present after heat treatment at a temperature of not less than 200.degree. C. and not more than 300.degree. C.
A method for the production of a heat-resistant prepreg, comprising the steps of
- (a) impregnating a heat-resistant substrate with a heat-resistant mixture composed of at least 10% by weight of a borosiloxane resin composition and a heat-resistant resin in an amount to make up 100% by weight, and
- (b) drying by heating the resulting impregnated substrate at a temperature of not less than 200.degree. C. and not more than 300.degree. C. to such an extent that at least 20% of the amount of phenyl groups bonded to the silicon atoms in said borosiloxane resin composition prior to the impregnating and drying steps remain after said heat treatment.
Dependencies are inferred from the claim text.