Patent ID: 7692318
Filing Date: 2010-04-06
Classification: C08G,H01L,Y10T

Abstract:
1. A liquid epoxy resin potting composition comprising (A) a liquid epoxy resin, said liquid epoxy resin being liquid at 25° C., (B) an aromatic amine curing agent, wherein the total amount of the aromatic amine curing agent is such that the ratio of the epoxy equivalent of the liquid epoxy resin to the amine equivalent of the aromatic amine curing agent is in the range from 0.7:1 to 1.2:1, (C) from 0.5 to 20 parts by weight per 100 parts by weight of components (A) and (B) combined of microcapsules containing a phenolic hydroxy-bearing benzoic acid derivative having the general formula (2): wherein R said microcapsules employing as their shell material a member selected from the group consisting of: polymers composed of (meth)acrylic monomers, polymers composed of monofunctional monomers, and polymers composed of polyfunctional monomers; said (meth)acrylic monomers selected from the group consisting of C said phenolic hydroxyl-bearing benzoic acid derivative being enclosed within the polymer shell, wherein said microcapsules (C) have an average particle size of 0.5 to 10 μm, and wherein an amount of the phenolic hydroxy-bearing benzoic acid derivative leached out from said microcapsules with cresol at 30° C. for 15 minutes is at least 70% by weight of the total content of the phenolic hydroxy-bearing benzoic acid derivative in said microcapsules, and (D) 50 to 1,200 parts by weight per 100 parts by weight of epoxy resin (A) and aromatic amine curing agent (B) combined of an inorganic filler having an average particle size of 2 to 20 μm and a maximum particle size of up to 75 μm.