Shell Oil Comapny

Shell Internationale Research Maatschappij, B.v.

Kunquan Yu

Garo Garbis Vaporciyan

A process for producing polycarbonate comprising contacting a dihydroxy capped carbonate and a diaryl carbonate in a reaction zone in the presence of a polymerization catalyst under polymerization conditions to produce polycarbonate. The dihydroxy capped carbonate is a carbonate with a dihydroxy compound on each end, and it is formed by the reaction of a dihydroxy compound with a dialkyl carbonate. The dihydroxy compound is a dihydroxy aromatic compound.

Method for producing polycarbonate

A process for producing polycarbonate comprising: a) contacting a dialkyl carbonate with a dihydroxy compound in an oligomerization zone in the presence of an oligomerization catalyst under oligomerization conditions to form a first intermediate; and b) contacting the first intermediate with a diaryl carbonate in a polymerization zone in the presence of a polymerization catalyst under polymerization conditions to produce the polycarbonate wherein the molar ratio of dihydroxy compound to dialkyl carbonate in the oligomerization zone is at least 2:1.

Method for preparing a melt polycarbonate

A process for preparing a diaryl carbonate from a dialkyl carbonate and an aryl alcohol is disclosed. The process takes place in apparatus comprising at least two distillation columns, and at least one of the distillation columns is operated at subatmospheric pressure which is achieved using vacuum equipment.

Process for preparing a diaryl carbonate

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.

Use of composition comprising titanium or zirconium alkoxide or aryloxide in aromatic carbonate preparation process

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&#x2014;Owherein 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&#x2014;Owherein 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.

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Katy, TX, United States of America

Kunquan Yu