PURPOSE: To obtain a copper-clad laminated sheet having excellent adhesivity to copper foil and high heat-resistance, by compounding a specific polybutadiene- epoxy resin with a compound composed of a cyanic acid ester and a bismaleimide and using the obtained composition solution as an impregnation varnish.
CONSTITUTION: The objective laminated sheet can be produced by (1) reacting (i) a terminal carboxyl-modified butadiene polymer containing ≥50% 1,2-butadiene unit having double bond on side chain in the polymer chain with (ii) 1.2W15 equivalent of an epoxy compound having ≥2 epoxy groups per 1mol based on 1 equivalent of the carboxyl group of the component (i), (2) diluting (A) 100pts.(wt.) of the obtained polybutadiene-epoxy resin and (B) 10W100pts. of a compound composed of a cyanic acid ester and bismaleimide with (C) an organic solvent, (3) adding an epoxy resin hardener and a polymerization catalyst to the solution to obtain an impregnation varnish, (4) impregnating a substrate with the impregnation varnish, (5) forming a prepreg sheet from the impregnated sheet and (6) laminating and hot-pressing a copper foil to the prepreg sheet.
OKA SEIJI
DOI MAKOTO
NAKAJIMA HIROYUKI
CHIDAI HIDEKI
