Hodogaya Chemical Co., Ltd.

Masatoshi Onishi

Tsutomu Nakamura

Akira Kuroda

Susumu Jinbo

Tetsuo Sasaki

Shoichi Kohno

A phenolic resin foam having excellent mechanical strength and flame resistance is obtained by letting a resinous mixture comprising a benzylic ether type phenolic resin, a blowing agent, an aromatic sulfonic acid, a polyisocyanate compound, and water to stand at room temperature or more so as to allow the mixture to foam and solidify.

Phenolic resin foam and process for producing the same

A polyurethane-modified polyisocyanurate foam having an excellent heat-resistance and flame-resistance and a reduced smoke-generation, comprises a reaction product of a mixture containing (A) at least one polyisocyanate compounds; (B) at least one polyol compound including, benzylic ether type phenolic resin of the formula (1): ##STR1## wherein R=H, hydrocarbon, oxyhydrocarbon or halogen, X=H or methylol, the molar ratio methylol/H.gtoreq.1, m+n.gtoreq.2 and m/m.gtoreq.1; p=1.about.3, (C) a trimerization catalyst, and; (D) a blowing agent, the ratio of the isocyanate equivalent of the isocyanate compound to the hydroxyl equivalent of the polyol compound being from 1.5 t 10.

Polyurethane-modified polyisocyanurate foam and method for producing the

4,4'-Dihydroxybiphenyl is produced by hydrolyzing 4,4'-dibromobiphenyl in the presence of a copper compound catalyst in an alkaline aqueous solution; extracting by-products from the alkaline aqueous solution with an alcohol or ketone which forms an organic phase; neutralizing or acidifying the alkaline aqueous solution with an acid; extracting the reaction product with the specific solvent; and crystallizing the reaction product from the extracted solution to obtain 4,4'-dihydroxybiphenyl having high purity.

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Yokohama, Japan

Masatoshi Onishi