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. 25, 1999
Filed:
Jun. 02, 1997
Applicant:
Inventors:
Assignee:
Mitsubishi Chemical Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
560 91 ; 560198 ; 560240 ; 560252 ; 568617 ; 528408 ; 528409 ; 528417 ;
Abstract
The present invention provides a process for the production of an ester of polyoxyalkylene glycol on an industrially favorable basis which comprises the ring opening polymerization of a cyclic ether in the presence of a carboxylic anhydride and a solid acid polymerization catalyst to obtain a polymer esterified at some or all of the ends thereof, wherein the water content in the reaction system is maintained at not more than 30 ppm by weight during the polymerization reaction.