Daicel Chemical Industries, Ltd.

Yutaka Fukuda

Tatsuya Kanno

Yasuhiro Oshino

Takaaki Kuwana

Tsutomu Yamato

Yoshimichi Okano

Yoshihiro Iguchi

Kenichi Sasaki

Michiyo Tanigawa

Ikuo Takahashi

Yoshiro Iguchi

Tsutomu Yamamoto

A process for preparing a substantially chloride-ion-free, high-molecular-weight, colorless and transparent polycarbonate by melt-polycondensing a dihydric phenol with a carbonic diester, which comprises using a carbonic diester which is substantially free from (A) phenyl salicylate, o-phenoxybenzoic acid and phenyl o-phenoxybenzoate, (B) tin ion, (C) methyl phenyl carbonate or (D) phenyl salicylate and o-phenoxybenzoic acid. A process for preparing a thermally stable polycarbonate by melt-polycondensing a dihydric phenol with a carbonic diester, which comprises using a borate or, a compound selected from the group consisting of electron-donative amines and salts thereof as a catalyst, and optionally an acidic substance.

Preparation of a polycarbonate by melt-polycondensation of a dihydric

In a process for producing a polycarbonate by subjecting a dihydroxy compound and a diester of carbonic acid to melt polycondensation through transesterification, after a polycarbonate prepolymer is prepared in the first-stage reaction, polycondensation is conducted as the second-stage reaction in a residence time in the range of from 15 to less than 60 min or through the use of at least one paddle-type self-cleaning twin-screw extruder This process enables a colorless, transparent polycarbonate having a high molecular weight to be produced at a high efficiency on an industrial scale.

Process for producing polycarbonate

A polycarbonate is produced by transesterification from a dihydroxy compound such as 2,2-bis(4-hydroxyphenyl)propane and a diester of carbonic acid such as bisphenyl carbonate in a reactor made of stainless steel and treated by electropolishing or acid pickling or buffed on a surface part thereof which contacts the reactants. As the transesterification catalyst, (a) a nitrogen-containing, electron-donating compound and (b) a nitrogen-containing, electron-donating compound and an alkali metal compound or an alkaline earth metal compound are preferably used.

A polycarbonate is produced by transesterification from a dihydroxy compound such as 2,2-bis(4-hydroxyphenyl)propane and a diester of carbonic acid such as bisphenyl carbonate in the presence of a substance which contains iron in an amount of 50% by weight or less and contacts the reactants. Alternatively, a polycarbonate is produced by transesterification from a dihydroxy compound and a diester of carbonic acid in a reactor made of stainless steel and treated by electropolishing or acid pickling or buffed on a surface part thereof which contacts the reactants. As the transesterification catalyst, (a) a nitrogen-containing, electron-donating compound and (b) a nitrogen-containing, electron-donating compound and an alkali metal compound or an alkaline earth metal compound are preferably used.

A (co)polycarbonate composition mainly comprising a (co)polycarbonate having a limiting viscosity number [.eta.] of 0.2 to 1.0 dl/g and terminal hydroxyl groups in an amount of 20 mole % or below, based on all the terminal groups of the (co)polycarbonate, and is substantially free from any branched structure which might otherwise be formed by a side reaction. The (co)polycarbonate contains chlorine (causasive of discoloration) in an amount of 10 ppm or below and an alkali metal ion and/or an alkaline earth metal ion in an amount of 1 ppm or below. A process for preparing the above (co)polycarbonate composition by the melt transesterification process involves the reaction of a dihydroxy compound such as bisphenol A and a carbonic diester such as diphenyl carbonate with a nitrogen-containing basic compound (a), and/or, a compound (b) containing an element selected from the group consisting of elements belonging to Groups I, II, IV and V of the periodic table as a catalyst.

(CO) polycarbonate composition and process for preparing the same

Process for the preparation of polycarbonate

A polycarbonate is produced by transesterification from a dihydroxy compound such as 2,2-bis(4-hydroxyphenyl)propane and a diester of carbonic acid such as bisphenyl carbonate in the presence of a substance containing iron in an amount of 50% by weight or less to contact the reactants. Also, a polycarbonate is produced by transesterification from a dihydroxy compound and a diester of carbonic acid in a reactor made of stainless steel and treated by electropolishing or acid pickling or buffed on a surface part thereof to contact the reactants. As the transesterification catalyst, (a) a nitrogen-containing, electron-donating compound and (b) a nitrogen-containing, electron-donating compound and an alkali metal compound or an alkaline earth metal compound are preferably used.

A process for the preparation of a substantially chlorine-free, high-molecular-weight, colorless and transparent (co)polycarbonate by melt-polycondensing a dihydroxy compound with a carbonic diester, which comprises using a carbonic diester which satisfies at lease one factor selected from the group consisting of:

Process for the preparation of (co)polycarbonate

In a process for producing a polycarbonate by subjecting a dihydroxy compound and a diester of carbonic acid to melt polycondensation through transesterification, after a polycarbonate prepolymer is prepared in the first-stage reaction, polycondensation is conducted as the second-stage reaction at a residence time in the range of from 15 to less than 60 min or through the use of at least one paddle-type self-cleaning twin-screw extruder. This process enables a colorless, transparent polycarbonate having a high molecular weight to be produced at a high efficiency on an industrial scale.

A process for producing a (co)polycarbonate or a (co)polyestercarbonate having a high molecular weight and excellent hue, heat stability and mechanical properties by reacting a dihydroxyl compound with a diester of carbonic acid and/or a diester of dicarbonic acid in the presence of a transesterification catalyst, wherein at least part of the reaction process is conducted in the presence of a specified organic phosphorus compound, or, in the presence of a specified organic phosphorus compound and a hindered phenol compound. A (co)polycarbonate or (co)polyester-carbonate composition having excellent hue, heat stability and mechanical properties, comprising a (co)polycarbonate and/or a (co)polyestercarbonate and, a specified organic phosphorus compound, or, a specified organic phosphorus compound and a hindered phenol compound.

Process for producing (co)polycarbonate and (co)polycarbonate composition

Process for producing (co)polycarbonate with transesterification

An optical disk of the invention comprises a substrate of an aromatic polycarbonate obtained by polymerizing one or two monomers polymerized through carbonate linkages and a recording layer coated thereon, said recording layer being recordable and readable by a laser beam,

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Hyogo, Japan

Yutaka Fukuda