Process for the production of aromatic polycarbonate
AssigneeTeijin Limited
InventorsKatsushi Sasaki, Wataru Funakoshi, Masumi Hirata, Masanori Abe, Hiroaki Kaneko
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Abstract
A process for the production of an aromatic polycarbonate, which comprises polycondensing an aromatic dihydroxy compound and a diaryl carbonate in the presence, as a polycondensation catalyst, of at least one alkali metal salt selected from the group consisting of alkali metal salts of ate-complexes of a metal element, which is silicon, germanium, stannum or plumbum, and alkali metal salts of oxoacids of said metal elements. The above aromatic polycarbonate is almost free from being colored, is also almost free from a decrease in polymerization degree when molded, and is further almost free from forming branches and insolubles.
Claims23
A process for the production of an aromatic polycarbonate having an intrinsic viscosity, measured in methylene chloride at 20.degree. C., of 0.1 to 1.0, which comprises polycondensing an aromatic dihydroxy compound and a diaryl carbonate in the presence, as a polycondensation catalyst, of at least one alkali metal salt selected from the group consisting of alkali metal salts of the following formula (II):
- M.sup.1 M.sup.2 X.sup.1.sub.p (OR.sup.6).sub.q (II)
- wherein M.sup.1 is an alkali metal, M.sup.2 is silicon, germanium, stannum or plumbum, X.sup.1 is an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, R.sup.6 is an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and each of p and q is an integer of 0 or 1 to 5, provided that p+q equals 3 or 5, and alkali metal salts of oxoacids of an element selected from the group consisting of silicon, germanium, stannum and plumbum.
Dependencies are inferred from the claim text.