Mitsubishi Gas Chemical Company, Inc.

Shin-etsu Chemical Co., Ltd.

Toshiaki Takata

Noriyoshi Ogawa

Takahiro Adachi

Satoshi Kanayama

Tadami Kinugawa

Hideo Otaki

Hironao Fujiki

Shigeki Shudo

Toshikazu Umemura

Tetsuo Tomita

Mituhiko Masumoto

Akira Matsuda

Masahiro Jono

Tatsuhide Hosomi

Yuji Mori

A process for producing a polycarbonate resin with high flowability having a viscosity average molecular weight (Mv) of 13,000 to 20,000 according to an interfacial polymerization method which comprises the steps of forming a reaction mixture while injecting phosgene into bisphenol, after the completion of injection of phosgene, adding a tetraammonium salt to the reaction mixture, then, conducting polycondensation reaction, after a viscosity average molecular weight (Mv) of a reaction mixture containing the resultant reaction products has reached to 3,000 or above and less than 6,000, adding a molecular weight modifier to the reaction mixture, further conducting polycondensation reaction, and thereby obtaining the polycarbonate resin.

Process for producing polycarbonate resin with high flowability

Disclosed are a polycarbonate resin with high flowability having a viscosity average molecular weight (Mv) of 13,000 to 20,000 and containing below 1% by weight of low molecular weight carbonate compounds having the range of molecular weight 1,000 or below and at least 10% by weight of a polycarbonate oligomer having the range of molecular weight 2,000 to 5,000 and a process for producing the same.

Polycarbonate resin with high flowability and process for producing the

A method of producing polycarbonate resin pellets containing very less residual organic solvent and low molecular weight volatile matters and having a high transparency by melt-kneading a polycarbonate resin powder in an extruder equipped with a screw having a material seal mechanism, and vents, and devolatilizing the residual organic solvent and/or the low molecular weight volatile matters at the vent portion and then extruding the molten resin. The polycarbonate resin pellets are suitable for optical grade articles and automobile lenses.

Production method of polycarbonate resin pellets

A polycarbonate derived from a novel dihydroxy compound having a triphenylamine structure, and a process for producing the polycarbonate are disclosed. The polycarbonate is obtained by reacting a dihydroxy compound having a triphenylamine structure described hereinbefore and a carbonate precursor, or by reacting the dihydroxy compound, a dihydric phenol compound and the carbonate precursor. The polycarbonate is useful as a plastic molding material or as a material for forming a polymer alloy with other resin.

Polycarbonate polymer derived from dihydroxy compound having

In a polycarbonate resin/silicone rubber integrally molded article, a polycarbonate resin having an aliphatic unsaturated group, typically an isopropenyl group is integrally joined to an addition type silicone rubber containing a tackifier component at high bond strength. It is prepared by injection molding a modified polycarbonate resin into a preform, injection molding a silicone rubber composition over the preform, and curing the composition at a temperature below the softening point of the polycarbonate resin.

Polycarbonate resin/silicone rubber integrally molded article and method

A thermoplastic resin composition comprising (a) 100 parts by weight of thermoplastic copolycarbonate comprising 0.1 to 50% by weight of structural unit of the following general formula (1) and 99.9 to 50% by weight of structural unit of the following general formula (2): ##STR1## and (b) 0.1 to 30 parts by weight of electroconductive carbon black can produce a molding product having good mechanical properties and surface smoothness with good moldability and (c) a polyester or styrenic resin.

Conductive copolycarbonate-siloxane compositions

A thermoplastic resin composition comprising (a) 100 parts by weight of thermoplastic copolycarbonate comprising 0.1 to 50% by weight of structural unit of the following general formula (1) and 99.9 to 50% by weight of structural unit of the following general formula (2): ##STR1## and (b) 0.1 to 30 parts by weight of electroconductive carbon black can produce a molding product having good mechanical properties and surface smoothness with good moldability.

Thermoplastic resin composition

A process for producing a polycarbonate resin having excellent heat stability from a dihydric phenol compound represented by the formula (1) shown below by an interfacial polymerization method wherein fatty acid represented by the formula (2), (3), (4) or (5) shown below is used as a terminator and as a polymerization catalyst, a quaternary ammonium salt is used, and after 5 to 40 minutes from the addition and emulsification of the polymerization catalyst, tertiary amine is added to cause polymerization. ##STR1## wherein all the symbols are the same as defined before.

Process for producing fatty acid-terminated polycarbonate resin

A process for the preparation of 4-hydroxy-2,4,6-trimethylcyclohexa-2,5-diene-1-one from 2,4,6-trimethylphenol is disclosed, comprising reacting 2,4,6-trimethylphenol with an aqueous solution or suspension of hypohalogenous acid or salt thereof in an aqueous medium or mixed medium of water and specific organic solvents. This process enables to prepare 4-hydroxy-2,4,6-trimethylcyclohexa-2,5-diene-1-one, which is a precursor for 2,3,5-trimethylhydroquinone, a starting material for the preparation of vitamin E, by a simplified operation, safely and at high yields.

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Osaka, Japan

Toshiaki Takata