Methods for preparing transparent articles from hydroquinone polycarbonate copolymers

US7528214B2 · kind B2 · utility

Assignee

• Sabic Innovative Plastics B.V. · NL

Inventors

• Gautam Chatterjee · Bengaluru, IN
• Patrick Joseph McCloskey · Watervliet, US
• Warren William Reilly · Northville, US
• William D. Richards · Cambridge, US
• Subash Scindia · Bengaluru, IN
• Gokul Srinivasan · Akron, US
• Yatin Tayalia · Bengaluru, IN

Key dates

• Filing date: Oct 28, 2005
• Grant date: May 5, 2009
• Expiry date: Aug 30, 2027

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G64/403
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A method for producing a transparent article comprises the steps of melt transesterifying a monomer mixture in the presence of a transesterification catalyst to produce a hydroquinone polycarbonate copolymer product comprising greater than 45 mole percent of structural units derived from the hydroquinone. The monomer mixture comprises a hydroquinone, at least one aromatic dihydroxy compound other than the hydroquinone, and a carbonic acid diester. The hydroquinone polycarbonate copolymer product is then heated to a highest processing temperature of 5° C. to 20° C. above a maximum melting melt temperature for the hydroquinone copolymer product for a sufficient period of time to render the hydroquinone polycarbonate copolymer product transparent upon cooling to ambient temperature; and cooling the hydroquinone polycarbonate copolymer product to produce the transparent article. The method can also be used for producing transparent hydroquinone polycarbonate copolymers, which can be used for producing the transparent articles.