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:
Jul. 08, 2003
Filed:
May. 26, 2000
Daicel Chemical Industries, Ltd., Osaka, JP;
Abstract
The invented process for producing a polyester supplies a crotonaldehyde with a purity of 95% by weight or more to a reaction system in the reaction of ketene with crotonaldehyde. In this process, unreacted crotonaldehyde may be recovered from a reaction mixture obtained by the reaction of ketene with crotonaldehyde and may be recycled to the reaction system. The &agr;vinylcrotonaldehyde content of the crotonaldehyde to be supplied to the reaction system is, for example, less than 0.5% by weight, and the paraldehyde content of the crotonaldehyde to be supplied to the reaction system is, for example, less than 5% by weight. By decomposing the above-prepared polyester with, for example, hydrochloric acid, a sorbic acid having a satisfactory hue can be efficiently obtained.