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. 04, 2006
Filed:
Dec. 11, 2003
Masaki Kato, Kurashiki, JP;
Kazuyuki Somemiya, Niigata, JP;
Syunji Tago, Niigata, JP;
Yoshiko Sho, Legal Representative, Kurashiki, JP;
Yukiko Sho, Legal Representative, Kurashiki, JP;
Masako Katayama, Kurashiki, JP;
Yoko Nakano, Kurashiki, JP;
Masaki Kato, Kurashiki, JP;
Kazuyuki Somemiya, Niigata, JP;
Syunji Tago, Niigata, JP;
Yoshiko Sho, legal representative, Kurashiki, JP;
Yukiko Sho, legal representative, Kurashiki, JP;
Masako Katayama, Kurashiki, JP;
Yoko Nakano, Kurashiki, JP;
Kuraray Co., Ltd., Kurashiki, JP;
Abstract
The present invention provides a new dispersion stabilizer that satisfies, at a high level, the performances required for a dispersion stabilizer used for suspension polymerization. A method of producing a dispersion stabilizer that is useable for suspension polymerization of a vinyl compound and contains a vinyl alcohol polymer (A) includes producing the vinyl alcohol polymer (A) by heat-treating a vinyl alcohol polymer (B) at a temperature of 90 to 180° C. for 0.5 to 20 hours in an atmosphere in which an oxygen concentration is 8000 ppm or lower. The vinyl alcohol polymer (B) has a saponification degree of at least 60 mol % and contains a residual acetic acid group whose block character is in the range of 0.3 to 0.6.