The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 12, 1994
Filed:
Jun. 18, 1992
Akihiro Naka, Kyoto, JP;
Shuichi Ito, Kyoto, JP;
Shinya Akizuki, Osaka, JP;
Kiyoshi Saito, Hyogo, JP;
Dai-Ichi Kogyo Seiyaku Co., Ltd., Kyoto, JP;
Nitto Denko Corporation, Osaka, JP;
Abstract
Copolycondensation of .alpha.-naphthol and .beta.-naphthol with an aldehyde compound gives a poly-hydroxynaphthalene compound having an average molecular weight of 300 to 2,000. This compound is useful as a curing agent for epoxy resins and as a precursor of epoxy resins. Epoxy resin compositions include (1) compositions comprising an epoxy resin and the poly-hydroxynaphthalene compound as a curing agent and (2) compositions comprising an epoxy resin obtained by reacting the poly-hydroxynaphthalene compound with an epihalohydrin and a curing agent. The epoxy resin compositions of the invention are characterized in that the cured resins have a high glass transition temperature and high heat stability and high moisture resistance, scarcely allowing package cracking even in soldering treatment. Therefore the compositions are suited for use in encapsulating semiconductors.