Daicel Chemical Industries, Ltd.

Tsutomu Yamato

Tatsuya Kanno

Yasuhiro Oshino

Yutaka Fukuda

Takaaki Kuwana

Yoshimichi Okano

Yoshihiro Iguchi

Michiyo Tanigawa

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.

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.

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

A polycarbonate is produced by melt-polycondensing a dihydric hydroxy compound and a bisarylcarbonate in the presence of a catalyst system comprising an electron donative amine compound and a compound selected from among alkali metal compounds and alkaline earth metal compounds. The process of the invention eliminates the use of poisonous phosgene, prevents chloride ions from being incorporated into the product polycarbonate and remains in the reaction system longer to enable the preparation of high-molecular weight polycarbonates.

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Hyogo, Japan

Tsutomu Yamato