Hitachi Chemical Company, Ltd.

Hitachi, Ltd.

Toshiyuki Fujita

Takayuki Saito

Akihiro Kobayashi

Tohru Kikuchi

Hiromasa Kawai

Toshio Akima

Hideaki Shibata

Yutaka Hosoi

Hiroshi Suzuki

Koichi Kamijima

Hidetaka Sato

Mitsumasa Kojima

Isamu Moribe

Yuugo Kumagai

A process for producing (i) a 1,3-bis(dicarboxyphenyl)disiloxane derivative represented by the general formula ##STR1## wherein Rs and R's independently of one another denote methyl or phenyl or (ii) a 1,3-bis(dicarboxyphenyl)-disiloxane derivative dianhydride represented by the general formula ##STR2## wherein Rs and R's are as defined above, the process comprising coupling a Grignard reagent of halo-o-xylene with a disubstituted halosilane represented by the general formula ##STR3## wherein R and R' are as defined above and X denotes halogen, to form a dimethylphenyl(disubstituted silane) represented by the general formula ##STR4## wherein R and R' are as defined above, hydroxylating the dimethylphenyl(disubstituted silane) to form a dimethylphenyl(disubstituted hydroxysilane) represented by the general formula ##STR5## wherein R and R' are as defined above, to form a 1,3-bis(dimethylphenyl)-disilane

Process for producing 1,3-bis(dicarboxyphenyl)-disiloxane derivative or

In a process for producing a methacrylic acid ester by subjecting methyl methacrylate and an alcohol to a transesterification reaction in the presence of a catalyst and a polymerization inhibitor, the filtration time of catalyst and the like can be shortened by making a total water content in the catalyst, alcohol and methyl methacrylate 1000 ppm or less, or the generation of large bubbles during the reaction can be prevented by adding the starting alcohol to the reaction system at the alcohol conversion of 40% or more, or high catalytic activity is obtained even if a secondary or tertiary alcohol is used as a starting material by using as a catalyst that obtained by drying lithium hydroxide monohydrate with heating, these effects being also obtained by combining individual conditions.

Process for producing methacrylic acid esters

An optical resin material comprising a polymer containing as an essential component at least one norbornyl acrylate or methacrylate or a derivative thereof is excellent in properties, particularly in moisture resistance and can be used for molding optical elements such as lenses, optical discs, etc.

Lens and optical disc base plate obtained from copolymer of norbornyl

A polyimide obtained from a polyamide-acid or polyamide-acid ester prepared by reacting dicyclohexyl-3,4,3', 4'-tetracarboxylic acid or dinanhydride with a diamine is excellent in transparency, heat resistance and mechanical properties, said polyimide being able to be obtained at a lower temperature, and particularly suitable for an orientation film used in a liquid crystal display device.

Dicyclohexyl-3,4,3',4'-tetracarboxylic acid or dianhydride thereof and

Methacrylate esters of alcohols having an ether linkage and/or an alicyclic ring can be obtained with no trouble of coloration or polymer formation during the production and for the product. An alcohol having an ether linkage and/or an alicyclic ring is treated with an alkaline substance, and the treated alcohol is caused to react with methyl methacrylate for a transesterification reaction in the presence of an alkaline substance.

Method for production of methacrylate ester

Disclosed are a para- or meta-terphenyl-3,4,3',4'-tetracarboxylic acid or a dianhydride and a process for preparing the same. The para- or meta-terphenyl-3,4,3',4'-tetracarboxylic acid or a dianhydride thereof according to the present invention is a novel compound which is useful as a raw material for a polyimide having higher heat resistance and so on.

Para- or meta-terphenyltetracarboxylic acid, dianhydride thereof and

Optical resin material

A toner for developing latent electrostatic images comprising a copolymer having as an essential component a monomer unit derived from an imido group-containing unsaturated monomer of the formula: ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 are as defined in the specification, has excellent properties such as resistance to adhesion to plasticized polyvinyl chloride, high image density, resistance to fogging, etc.

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Hitachi, Japan

Toshiyuki Fujita