Other

Matsushita Electric Works, Ltd.

Tohto Kasei Co., Ltd.

Toshiharu Takata

Chiaki Asano

Masao Gunji

Hiroshi Sato

Kiyoaki Ihara

Hidetaka Kakiuchi

Takashi Sagara

Kazuo Ishihara

The present invention features phosphorus containing epoxy resin compositions useful for imparting flame retardant properties to prepregs, resin-clad metal foils, and laminate boards constructed therefrom. The phosphorus containing epoxy resin composition (a) comprises a phosphorus containing epoxy resin (A) and a hardener. The phosphorus containing epoxy resin (A) has an epoxy equivalent of 300-500 g/eq. and comprises the reaction product of a phosphorus containing organic compound (B) and at least one epoxy resin (C). Phosphorus containing compound (B) is the reaction product of organic phosphorus compounds (b) having one active hydrogen atom bonded to a phosphorus atom and a quinone compound, wherein the molar ratio of (b) to quinone is from 1.25:1 to 2:1. This molar excess of (b) yields a phosphorus containing compound (B) that comprises both the reaction product of (b) and quinone, as well as un-reacted (b). Epoxy resin (C) is selected from a group of specific aromatic-containing epoxy resins, and the content of epoxy resin (C) comprises from 20 to 45 wt. % of (A).

Epoxy resin compositions containing phosphorus, flame retardant resin sheet using said epoxy resin containing phosphorus, resin clad metal foil, prepreg and laminated board, multi layer board

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Kadoma, Japan

Toshiharu Takata