PURPOSE: To provide superior fire retardancy, heat resistance, humidity resistance, electrical characteristics and punching properties and reduce expansion and shrinkage in the width direction by using a glass fiber non-woven cloth as a base and including a large amount of aluminum hydroxide or magnesium hydroxide in phenol resin.
CONSTITUTION: 50wt.% or more of aluminum hydroxide or magnesium hydroxide to resin is included in the resin of a laminate to be laminate molded by impregnating a glass fiber non-woven cloth base with phenol resin. As for the phenol resin, oil-modified phenol resin, melamine-modified phenol resin or the like used in general is properly used. Aluminum hydroxide or magnesium hydroxide is mixed with resin at the time of impregnating the base with phenol resin. When 150wt.% or more is mixed to the solid weight of resin, the base is likely to run short at the time of impregnation, which is not preferred. As aluminum hydroxide or magnesium hydroxide, gibsite crystal structure of high pyrolysis temperature is preferred, and 20μ or less of the average grain diameter is preferred.
KAMATA MITSUTOSHI
OGATA MASARU
