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:
Jan. 04, 1994
Filed:
Sep. 04, 1990
Applicant:
Inventors:
Hendrik E Tuinstra, Midland, MI (US);
Cynthia L Rand, Sanford, MI (US);
Assignee:
The Dow Chemical Company, Midland, MI (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08G / ;
U.S. Cl.
CPC ...
528371 ; 526 67 ; 526 68 ; 528196 ; 528271 ; 528370 ;
Abstract
A process for the preparation of an aromatic carbonate or polycarbonate from a phenol or bisphenol, methanol, carbon monoxide and oxygen comprising the steps of 1) reacting phenol or bisphenol with acetic anhydride to form (bis)phenyl acetate; 2) reacting dimethyl carbonate with (bis)phenyl acetate from step 1 to produce a phenyl carbonate or polycarbonate and methyl acetate; and 3) reacting the methyl acetate with carbon monoxide to produce acetic anhydride for use in step 1. In a desirable embodiment the dimethyl carbonate may also be prepared by reaction of methanol, carbon monoxide and oxygen.