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:
Dec. 21, 1982
Filed:
Jun. 24, 1981
Applicant:
Inventor:
Darold L Madigan, Elk Grove Village, IL (US);
Assignee:
PPG Industries, Inc., Pittsburgh, PA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08G / ;
U.S. Cl.
CPC ...
528371 ; 524405 ; 524409 ; 524435 ; 528372 ;
Abstract
In the preparation of a substantially linear carbonate polymer wherein carbonic dihalide is introduced to a substantially anhydrous solution comprising at least one substituted or unsubstituted 1,3-propanediol, the coproduction of cyclic carbonate is reduced by the presence in the solution of a catalytic amount of nitrogen-containing, hydrohalide salt-forming, thermally regenerable organic catalyst. The preferred carbonic dihalide is phosgene and the preferred catalyst is pyridine.