The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 27, 1996
Filed:
Jun. 01, 1995
Daicel Chemical Industries, Ltd., Osaka, JP;
Abstract
A processes for producing a (co)polycarbonate having a low terminal hydroxyl group concentration and being excellent in heat resistance and hue, which comprises melt-polycondensing a dihydroxy compound with a carbonic diester in the presence of a catalyst for transesterification selected from the group consisting of a nitrogen-containing basic compound, an alkali metal borate and an alkaline earth metal borate and in the presence of a specific ester compound. A process for producing a linear, high-molecular weight (co)polycarbonate being excellent in heat resistance, hydrolysis resistance, hue and impact resistance which comprises melt-polycondensing a dihydroxy compound with a carbonic diester in the presence of a catalyst for transesterification selected from the group consisting of specific borates. A process for producing a (co)polycarbonate being excellent in heat resistance, hydrolysis resistance, hue and impact resistance which comprises melt-polycondensing a dihydroxy compound with a carbonic diester in the presence of boric acid and/or ammonium hydrogenphosphite.