Kabushiki Kaisha Sanko Kaihatsu Kagaku Kenkyusho

Sekisui Kagaku Kogyo Kabushiki Kaisha

Sanko Co., Ltd.

Sanko Kaihatsu Kagaku Kenkyusho

Sekisui Chemical Co., Ltd.

Nicca Chemical Co., Ltd.

Daishiro Kishimoto

Toranosuke Saito

Hiroki Tsunomachi

Kazuo Doyama

Akihiro Niki

Makoto Yamaguchi

Makoto Ohsuga

Toshio Uesaka

Shigeru Oda

Juji Uchida

Toru Makino

Katsuya Okumura

Yoichi Umeki

Disclosed herein is a method of preparing a high-melting point flame retardant crystal, comprising the steps of: reacting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide with 1,4-naphthoquinone in an inert solvent having a dielectric constant of 10 or less to reduce a content of by-products, thereby obtaining a reaction composition; and dissolving the reaction composition in any one solvent selected from the group consisting of ethyleneglycol, propyleneglycol, diethyleneglycol, cyclohexanone, benzyl alcohol, acetate ester, benzoate ester and a mixture thereof to recrystallize and refine the reaction composition, thereby obtaining high-melting point retardant crystal, represented by Formula 1, having a start melting point of 280&#xb0; C. or more and a melting point of 291&#xb0; C. or more, which are measured by differential thermogravimetric analysis.

High melting point flame retardant crystal and method for manufacturing the same, epoxy resin composition containing the flame retardant, and prepreg and flame retardant laminate using the composition

A flame-retardant synthetic resin composition characterized by comprising 1-40 parts by weight of at least one type of organic phosphorus compound represented by the following general formula (1): (wherein Rrepresents alkyl, aralkyl, etc.) with respect to 100 parts by weight of a synthetic resin.

Flame resistant synthetic resin composition

A method for preparing a sulfone represented by the following formula: ##STR1## wherein R' represents a lower alkyl group, an aryl group or an aryl group whose nucleus has at least one substituent selected from the group consisting of a halogen atom, nitro group, a lower alkyl group, phenyl group and a phenyl group substituted with a halogen atom, or an alkali metal salt thereof. A sulfonic acid ester of 4-hydroxybiphenyl is condensed at a temperature of 0.degree. to 200.degree. C. in a presence of a Lewis acid or a super-strong acid with a sulfonyl chloride represented by the formula R'SO.sub.2 Cl, wherein R' is the same as that defined above.

Method for preparing sulfones

An engineering plastic composition with excellent flowability, heat stability, and desirable mechanical properties is provided. The composition contains an engineering plastic material and an aliphatic polyester.

Engineering plastic composition and articles made of the same

A method for preparing a sulfone represented by the following formula: ##STR1## wherein R and R' each represent a lower alkyl group, an aryl group or an aryl group whose nucleus has at least one substituent selected from the group consisting of a halogen atom, nitro group, a lower alkyl group, phenyl group and a phenyl group substituted with a halogen atom, comprises the step of condensing a sulfonic acid ester of 4-hydroxybiphenyl represented by the following formula: ##STR2## with a sulfonyl chloride of R'SO.sub.2 Cl at a temperature of 0.degree. to 200.degree. C. in the presence of a Lewis acid or a superstrong acid.

A polyester is provided that comprises as main monomer components thereof a dicarboxylic acid and a diol, including a p-quaterphenyl derivative of specific formula. The use of appropriate kinds of dicarboxylic acid for the polyester makes it possible to obtain a thermoplastic elastomer or an engineering platic material (i.e., liquid-crystal polymer).

Polyester and an article made of the same

A polyester is provided that comprises as main monomer components thereof a dicarboxylic acid and a diol, including a p-quaterphenyl derivative of specific formula. The use of appropriate kinds of dicarboxylic acid for the polyester makes it possible to obtain a thermoplastic elastomer or an engineering plastic material (i.e., liquid-crystal polymer).

Polyester and an article made of the same comprising a p-quaterphenyl

An engineering plastic composition with excellent flowability, heat stability, and desirable mechanical properties is provided. The composition comprises an engineering plastic material and at least one p-quaterphenyl derivative of specific formula.

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Ibaraki, Japan

Daishiro Kishimoto