In an embodiment, a reactor for carrying out a melt transesterification reaction at a reactor temperature of 160 to 300° C. and a reactor pressure of 5 to 200 mbar, comprises a cylindrical tank comprising a top, a side, and a bottom, wherein the bottom is convex, extending away from the top; a stirring shaft disposed within the cylindrical tank along an axis thereof so that it is rotatable from outside of the cylindrical tank; a stirring blade extending from the stirring shaft in the cylindrical tank; a reactant solution inlet located on the bottom; and a reaction solution outlet located on the bottom. The reactor can be used for the polymerization of a polycarbonate oligomer.

A resin composition contains: a resin containing a constituent unit (A) represented by general formula (1); and a resin containing a constituent unit (B) represented by formula (2) and/or a constituent unit (C) represented by formula (3). (R.sub.1 represents a methyl group or an ethyl group, R.sub.2 and R.sub.3 represent a hydrogen atom or a methyl group, and n represents 0 or 1.) (R.sub.a and R.sub.b represent a hydrogen atom, etc., R.sub.h represents an aryl group of 6-20 carbons, X represents a single bond or a fluorene group, A and B represent an alkylene group of 1-4 carbons, m and n represent integers 0-6, and a and b represent integers 0-10.) (R.sub.c and R.sub.d represent a hydrogen atom, etc., Y represents a fluorene group, A and B represent an alkylene group of 1-4 carbons, p and q represent integers 0-4, and a and b represent integers 0-10.)

##STR00001##

The present invention relates to a melt transesterification process for the production of (co)polycarbonates from diaryl carbonates and cycloalkylidene diphenols, which process comprises the addition of a monohydroxyaryl compound in an amount of 5.0 to 20.0 wt.-%, based on the total mass of the reaction mixture. The invention further relates to a (co)polycarbonate obtained by the process.

The invention relates to a process for preparing an aromatic carbonate, comprising reacting a dialkyl carbonate or an alkyl aryl carbonate with an aryl alcohol or an alkyl aryl carbonate, resulting in an aromatic carbonate which is an alkyl aryl carbonate or a diaryl carbonate, wherein a composition comprising a titanium or zirconium alkoxide or aryloxide, wherein the alkoxy group in the titanium or zirconium alkoxide is a group of formula R-0˜ wherein R is an alkyl group having 1 to 4 carbon atoms and the aryloxy group in the titanium or zirconium aryloxide is a group of formula Ar-0˜ wherein Ar is an aryl group having 6 to 12 carbon atoms, and wherein the composition additionally comprises 0.1 to 50 wt. % of an alcohol, based on the total weight of the composition, is mixed with an alcohol or an organic carbonate, and the mixture thus obtained is contacted with said dialkyl carbonate or alkyl aryl carbonate and aryl alcohol or alkyl aryl carbonate to catalyze the preparation of the aromatic carbonate. Further, the invention relates to a process for making a polycarbonate from the diaryl carbonate thus prepared.

Provided is a polycarbonate resin which maintains favorable properties as an optical material while having fluidity suitable for molding. Furthermore, provided are an optical lens and an optical film that use the polycarbonate resin. The polycarbonate resin is characterized by comprising a component unit (A) expressed by general formula (1) and a component unit (B) expressed by general formula (2).

##STR00001##

##STR00002##

A polycarbonate resin having a high refractive index, a low Abbe number and a high moisture and heat resistance is provided. In an embodiment, a polycarbonate resin including a structural unit represented by general formula (1) below is provided.

##STR00001##

The invention relates to a composition comprising a titanium or zirconium alkoxide or aryloxide, wherein the alkoxy group in the titanium or zirconium alkoxide is a group of formula R-0.sup.− wherein R is an alkyl group having 1 to 4 carbon atoms and the aryloxy group in the titanium or zirconium aryloxide is a group of formula Ar-0.sup.− wherein Ar is an aryl group having 6 to 12 carbon atoms, and wherein the composition additionally comprises 0.1 to 50 wt. % of an organic carbonate, based on the total weight of the composition. Further, the invention relates to a process for preparing such composition, comprising blending such titanium or zirconium alkoxide or aryloxide with an organic carbonate in such amounts that the resulting composition comprises 0.1 to 50 wt. % of the organic carbonate, based on the total weight of the composition. Still further, the invention relates to a process for preparing an aromatic carbonate, such as a diaryl carbonate, using said composition comprising a titanium or zirconium alkoxide or aryloxide; and to a process for making a polycarbonate from the diaryl carbonate thus prepared.

The present invention relates to the use of an aromatic polycarbonate prepared by the transesterification of a bisphenol and a diaryl carbonate and having a viscosity average molecular weight, Mv, of from 22000 to 32000 g/mol, a polydispersity, defined as Mw/Mn, of from 1.8-3.2, a melt-flow index of from 3.0-10 g/10 min as determined in accordance with ASTM D 1238 (1.2 kg, 300° C.), an amount of Fries branching of from 750 to 2500 ppm, for the manufacture of bottles having a volume of at least 15 liter by means of an injection blow moulding or an extrusion blow moulding process.

In an embodiment, a melt polymerization process comprises melt polymerizing a carbonate compound and a dihydroxy compound in the presence of a catalyst composition to form a polycarbonate; and adding an end-capping agent comprising a mono-phenolic compound to the polycarbonate, wherein the adding of the end-capping agent comprises at least one of adding the end-capping agent just upstream of a final polymerization unit, adding the end-capping agent directly into the final polymerization unit, and adding the end-capping agent downstream of the final polymerization unit; wherein a molecular weight of the polycarbonate increases by less than 10% downstream of the final polymerization unit.

A polycarbonate-polyolefin block copolymer and a process to form a polycarbonate-polyolefin block copolymer by combining mono- or di-hydroxyaryl with vinyl/vinylidene terminated polyolefin to form a polyolefin hydroxyaryl moiety, and combining the polyolefin hydroxyaryl moiety with di-hydroxyaryl and di-substituted carbonyl monomers to form a polycarbonate-polyolefin block copolymer.