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:
Jun. 29, 1999
Filed:
Aug. 26, 1997
Mitsui Chemicals, Inc., Tokyo, JP;
Abstract
The invention relates to a preparation process of aliphatic polyester, comprising using an ion exchange resin as a drying agent and after the dehydration polycondensation reaction, regenerating and drying the used ion exchange resin and repeatedly using said ion exchange resin in the next dehydration polycondensation reaction, in a process for preparing aliphatic polyester from one or more aliphatic compound (A) by heating in an organic solvent in the presence of a catalyst, distilling a generated water containing organic solvent out of the reaction system, treating the distilled organic solvent with a drying agent, and returning the treated solvent to the reaction system to progress a dehydration polycondensation reaction. The process of the invention enables one to steadily and efficiently prepare in industry an aliphatic polyester having an excellent color tone, high molecular weight and high quality.