Method for producing a crystallized aromatic polycarbonate, and a crystallized aromatic polycarbonate obtained thereby
CA 1305579 C · Owner: Watanabe, Tomonari · Inventors: Dozono, Tetsuro; Fukuoka, Shinsuke; Watanabe, Tomonari
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A crystallized aromatic polycarbonate having a weight average molecular weight of from 6,000 to 200,000 and having a terminal hydroxyl group content of not greater than 0.03 % by weight based on the weight of the polycarbonate is effectively produced by first heating a mixture of a dihydroxydiaryl compound comprising at least 85 mole % of a dihydroxydiaryl alkane with a diaryl carbonate to prepare a prepolymer having a weight average molecular weight of from 2,000 to 20,000 and having terminal aryl carbonate groups in an amount of greater than 50 mole %, based on the total number of moles of all the terminal groups of the prepolymer secondly crystallizing the prepolymer and finally …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted July 21, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 21, 2009.
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Timeline
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Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.