| abstract |
PURPOSE: To prepare the title compsn. excellent in transparency, crack resistance, etc., and hardly undergoing degradation in luminance by mixing a bisphenol epoxy resin, an alicyclic epoxy resin, an epoxidized 1,2-polybutadiene, and a phthalic anhydride. n CONSTITUTION: A bisphenol epoxy resin (e.g. a bisphenol A epoxy resin), an alicyclic epoxy resin [e.g. Celloxide 2021 (a trade name)], an epoxidized 1,2- polybutadiene (e.g. a compd. of the formula wherein (n) is about 5), and a phthalic anhydride (e.g. hexahydrophthalic anhydride) are mixed as essential components to give the title compsn. A curing accelerator, a reductive discoloration preventive, etc., may further be added to the compsn. The epoxidized 1,2- polybutadiene mixed with the bisphenol epoxy resin as above lowers the stress in the compsn. n COPYRIGHT: (C)1992,JPO&Japio |