Sumitomo Chemical Company, Limited

Kazuo Sumiyoshi

Shuichi Kanagawa

Kunimasa Kamio

Hisao Takagishi

Yoshiya Fukuyama

Katsuo Akagane

Makoto Nakahara

An epoxy resin composition comprising a novolak type epoxy resin which is produced from a substituted-phenol novolak and epihalohydrin, and is 0.15 or less in a maximum absorbance of a 3% (W/V) dichloromethane solution of the epoxy resin, the absorbance being measured at a wave number of between 3570 and 3600 cm.sup.-1 with an infrared spectrophotometer having a cell of 2 mm length, which is useful particularly in encapsulating and laminating applications in electronic fields.

Method for producing encapsulated semiconductor from improved epoxy

Unsaturated epoxy esters with improved curability are prepared by the reaction of (1) a partial esterification compound obtained from trimellitic anhydride and/or pyromellitic anhydride and an unsaturated monoalcohol; (2) (i) a partial esterification compound obtained from a dicarboxylic anhydride and an unsaturated monoalcohol and/or ( ii) a polymerizable unsaturated monobasic acid; and (3) a compound containing at least two epoxy groups in one molecule; if desired in the presence of (4) a dicarboxylic acid or a saturated or unsaturated alkyd having carboxyl groups at both terminals and/or a saturated or unsaturated monoglycidyl compound.

Unsaturated epoxy ester resin

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Oita, Japan

Kazuo Sumiyoshi