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:
Oct. 21, 2008
Filed:
Sep. 10, 2004
Hisamichi Yanai, Kurashiki, JP;
Yoshihiro Tokuda, Kurashiki, JP;
Jin Tokuyasu, Kurashiki, JP;
Kimiko Miyata, Kurashiki, JP;
Naoki Fujiwara, Osaka, JP;
Takeshi Kusudou, Kurashiki, JP;
Hisamichi Yanai, Kurashiki, JP;
Yoshihiro Tokuda, Kurashiki, JP;
Jin Tokuyasu, Kurashiki, JP;
Kimiko Miyata, Kurashiki, JP;
Naoki Fujiwara, Osaka, JP;
Takeshi Kusudou, Kurashiki, JP;
Kuraray Co., Ltd., Kurashiki-shi, JP;
Abstract
The present invention provides polyvinyl alcohol based (PVA) whose solubility in water varies with a small temperature change to a sufficiently great degree. In manufacturing a polyvinyl alcohol based polymer by: progressing a transesterification reaction of a polyvinyl ester based polymer with alcohol in a liquid reaction mixture including the polyvinyl ester based polymer, the alcohol, and a basic compound; precipitating the polyvinyl ester based polymer, at least a part of which has been transesterified with the alcohol, out of the liquid reaction mixture; and further progressing the transesterification reaction in the liquid reaction mixture including the polyvinyl ester based polymer that has precipitated, the liquid reaction mixture has a temperature of 75° C. to 150° C. when the polyvinyl ester based polymer, at least a part of which has been transesterified, starts precipitating.