| 摘要 |
PURPOSE:To improve moldability, printability, moisture resistance, thermal shock resistance, etc., by compounding a random-copolymerized silicone-modified epoxy resin, a specified curing agent, a silicone copolymer, a silicon rubber and a filler. CONSTITUTION:A random-copolymerized silicone-modified epoxy resin (A) is obtd. by reacting an epoxy resin (a) of an epoxy equivalent of 150-250 and a softening point of 60-130 deg.C, contg. a small amt. of ionic impurities and having two or more epoxy groups in the molecule with an organopolysiloxane (b) having a functional group reactive with the component (a). Separately, a random-copolymerized silicone-modified phenolic resin curing agent (B) is obtd. by reacting a phenol novolak resin (c) of an OH equivalent of 80-150 and a softening point of 60-120 deg.C and contg. a small amt. of ionic impurities with an organopolysiloxane (d) having a functional group reactive with the component (c). A mixture of the components A and B, 0.1-2wt.% silicone copolymer (C) of an SP value of 7-9 based on the mixture, 1-20wt.% silicone rubber (D) of an SP value of 7-9 based on the mixture and an inorg. filler (E) are compounded together. |
