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:
Nov. 05, 2002
Filed:
May. 26, 2000
Mitsunori Ito, Ichihara, JP;
Idemitsu Petrochemical Co., Ltd., Tokyo, JP;
Abstract
Provided are an aromatic polycarbonate copolymer and a method for producing it. An aromatic dihydroxy compound, at least one member selected from the group consisting of polyorganosiloxanes and aliphatic polyalcohols, and a dicarbonate are prepolymerized under heat to give a polycarbonate prepolymer, and the prepolymer is polymerized in a solid or swollen solid phase in the presence of a quaternary phosphonium salt serving as a catalyst to give an aromatic polycarbonate copolymer. The remaining monomer content, the acetone soluble content (that is, the low-molecular-weight substance content) and the cyclic oligomer content of the copolymer are all reduced, and the terminal hydroxyl fraction thereof is also reduced.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile