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:
Mar. 22, 2011
Filed:
Nov. 02, 2005
Kazuhiro Okamura, Sanda, JP;
Norihiro Wakao, Yokohama, JP;
Keiji Watanabe, Jyoetsu, JP;
Keiichi Fujise, Kusatsu, JP;
Kazuhiro Okamura, Sanda, JP;
Norihiro Wakao, Yokohama, JP;
Keiji Watanabe, Jyoetsu, JP;
Keiichi Fujise, Kusatsu, JP;
Nippon Shokubai Co., Ltd., Osaka, JP;
Dai-Ichi Kogyo Sei Yaku Co., Ltd., Kyoto, JP;
Abstract
The present invention is a powder of a vinylpyrrolidone polymer having a K value of smaller than 50, characterized in that a content of particles having a particle diameter of 106 μm or smaller is 10% by mass or less and a content of particles having a particle diameter of greater than 1,000 μm is 5% by mass or lower. A process for production of a powder of a vinylpyrrolidone polymer according to the present invention is characterized in that a vinylpyrrolidone polymer having a K value of smaller than 50 is formed into a solution having a concentration from 30% to 70% by mass, and the solution is dried by using a hot surface adhesion-type dryer, followed by pulverization so that a content of particles having a particle diameter of 106 μm or smaller is 10% by mass or lower and a content of particles having a particle diameter of greater than 1,000 μm is 5% by mass or lower. Thus, there is provided a powder of a vinylpyrrolidone polymer, which has excellent solubility in spite of having a low K value determined by a Fikentscher method and can be made into solution with favorable handleability without dust rising, and a process for production of the same.