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:
May. 02, 1989
Filed:
May. 23, 1988
Applicant:
Inventors:
Assignee:
Shell Oil Company, Houston, TX (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08G / ;
U.S. Cl.
CPC ...
528405 ; 528371 ; 528372 ;
Abstract
Process for the preparation of polycarbonates by reacting at least one epoxy compound with carbon dioxide at 40.degree. to 200.degree. C. and 2 to 40 bar in the presence of a catalytic amount of a double metal cyanide complex and (a) one or more salts composed of at least bivalent metal ions and metal-free anions having a solubility in water of at least 1 g/100 ml at 25.degree. C., and/or (b) one or more no-metal containing acids of which a 0.1 N solution in water at 25.degree. C. has a pH not exceeding 3.