Ube Industries, Inc.

Mikio Fujimoto

Hiroshi Sato

Nobuyuki Kuroda

Toshikazu Machida

Yasuhiro Tanaka

Motozo Yoshikiyo

Mitsumasa Tsugawa

Sanae Hatakenaka

Hiroshi Itatani

Akinori Shiotani

Hiroshio Sato

A process for the production of trialkoxyhalosilanes which comprises reacting a tetrahalosilane [37] with a tetra-alkoxysilane [38] in the presence of an alcohol whose alkoxy group is the same as those of the tetraalkoxysilane to thereby obtain a trialkoxyhalosilane [39], characterized in that the alcohol is used in an amount of 5 to 50% by mole based on the total amount of Si of the tetrahalosilane and the tetraalkoxysilane: SiX[37] (wherein X is halogeno) Si(OR)[38] (wherein Ris a hydrocarbon group having 1 to 6 carbon atoms) XSi(OR)[39] (wherein X and Rare each as defined above).

Process for production of trialkoxyhalosilanes

A process for the production of trialkoxyhalosilanes which comprises reacting a tetrahalosilane [37] with a tetra-alkoxysilane [38] in the presence of an alcohol whose alkoxy group is the same as those of the tetraalkoxysilane to thereby obtain a trialkoxyhalosilane [39], characterized in that the alcohol is used in an amount of 5 to 50% by mole based on the total amount of Si of the tetrahalosilane and the tetraalkoxysilane: SiX[37] (wherein X is halogeno) Si(OR)[38] (wherein Ris a hydrocarbon group havingtocarbon atoms) XSi(OR)[39] (wherein X and Rare each as defined above).

A biphenyltetracarboxylic ester, particularly, 3,3',4,4'-biphenyltetracarboxylic tetraester, is prepared in an increased yield by first oxidative coupling, at 140.degree. C. to 260.degree. C., an o-phthalic diester with a molecular oxygen-containing gas, for example, air, in the presence of a catalyst comprising predetermined amounts of a Pd salt, a basic bidentate ligand compound, and a Cu salt to convert a portion of the o-phthalic diester to the corresponding biphenyltetracarboxylic ester and by additionally oxidative coupling in one or more steps, in each step, the remaining portion of o-phthalic diester with a molecular oxygen-containing gas at 140.degree. C. to 260.degree. C. while controlling the composition of the catalyst to an extent such that the entire molar amount of the Pd salt is 0.0001 to 0.01 time that of the o-phthalic diester, the entire molar amount of the ligand compound is 0.5 to 4 times that of the Pd salt and the entire molar amount of the Cu salt is 0.01 to 5 times that of the Pd salt.

Method for producing biphenyltetracarboxylic esters

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Yamaguchi, Japan

Mikio Fujimoto