Mitsubishi Gas Chemical Company, Inc.

Shigeo Yanada

Mituhiko Masumoto

Masahiro Harada

Senzo Shimizu

Isao Nomura

Toshiaki Izumida

Susumu Taniyama

Tadami Kinugawa

Kazuyuki Akahori

Motohachi Usui

A polycarbonate resin having an improved flexibility, flowability and heat resistance, and a process for producing such polycarbonate resins are disclosed. The polycarbonate resin of this invention is particularly useful as optical articles and other precision molding materials and is produced by a solution polymerization method using a bisphenol compound and a substituted alkylenebisphenol compound.

Copolycarbonate resin from branched chain alkylene bis phenol

A transparent optical article is disclosed, which is produced by molding a branched polycarbonate resin having a viscosity average molecular weight of from 13,000 to 20,000 as prepared from at least one dihydric phenol compound in the presence of a polyfunctional organic compound having at least two phenolic hydroxyl groups as a branching agent in an amount of from 0.02 to 3 mol % based on the total amount of the dihydric phenol compound. The transparent molded optical article includes digital audio discs, video discs, memory discs and lenses used in the optical reading system. The optical article is greatly reduced in double refraction and has a high mechanical strength.

Optical articles of branched polycarbonate resin

A process for producing an aromatic polyester carbonate resin in which the molar ratio of the dihydric phenolic compound residue to aromatic dicarboxylic acid residue to carbonate bond is in the range of 2:0.5:1.5-2:1.4:0.6 and these constituent components form an alternating configuration of high regularity, said process comprising a first step wherein in producing a hydroxyl-terminated aromatic oligocarbonate by reacting a dihydric phenolic compound with a halogenated carbonyl compound in a reaction medium consisting of water and a water-immiscible solvent in the presence of a basic inorganic compound, the reaction is carried out by using the basic inorganic compound in an amount of 0.6-1.6 moles per mole of the dihydric phenolic compound and the halogenated carbonyl compound in an amount of 0.3-0.8 mole per mole of the dihydric phenolic compound to form a reaction product mixture consisting predominantly of a phenolic hydroxyl-terminated oligocarbonate of a degree of polymerization of 1-3, and a second step in which an esterification reaction is carried out by reacting the reaction product mixture obtained in the first step with an aromatic dicarboxylic acid dichloride in the presence of a basic inorganic compound in an amount at least sufficient to neutralize the free phenolic hydroxyl groups that remain in the reaction product mixture.

Process for producing aromatic polyester carbonate resin

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Osaka, Japan

Shigeo Yanada