Title:
VINYLPYRROLIDONE-BASED POLYMER AND METHOD FOR PRODUCING THE SAME
Document Type and Number:
Japanese Patent JP2008063493
Kind Code:
A
Abstract:
To provide a vinylpyrrolidone-based polymer having a reduced change of K value in an alkaline solution and a method for producing the same.
In a method for producing the vinylpyrrolidone-based polymer by polymerizing a vinylpyrrolidone monomer in a solution using a radical polymerization initiator, a solution containing the vinylpyrrolidone monomer and a sulfite is prepared and the polymerization is performed by continuously or intermittently adding an azo-based initiator having 60C 10-hour half-time temperature to the solution. By the method, a vinylpyrrolidone-based polymer expressing 3% rate of change in K value after 3 months preservation at 50C is produced.
Inventors:
YOSHIDA YUJI
Application Number:
JP2006244501A
Publication Date:
March 21, 2008
Filing Date:
September 08, 2006
Export Citation:
Assignee:
DAI ICHI KOGYO SEIYAKU CO LTD
International Classes:
C08F26/10; C08F2/04; C08F4/04
Attorney, Agent or Firm:
Tamako Tsutada
Masato Tsuda
Tetsuji Nakamura
Katsuyuki Tomita
Husband
Masato Tsuda
Tetsuji Nakamura
Katsuyuki Tomita
Husband