Title:
METHOD FOR TREATING VINYLPYRROLIDONE-BASED POLYMER
Document Type and Number:
Japanese Patent JP3274127
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a method for treating a vinylpyrrolidone-based polymer by which changes in physical properties such as molecular weight (K value) or Hazen color index can be suppressed in all situations, e.g. in preservation for a long period, in preservation at a high temperature, further in a drying process, in a grinding process, etc.
SOLUTION: An oxygen concentration in a vapor phase brought into contact with the vinylpyrrolidone-based polymer is controlled to ≤50,000 ppm.
Inventors:
Taisei Tomihisa
Tomiyasu Ueda
Toshiaki Kuriyama
Akio Naka
Hideyuki Nishibayashi
Tomiyasu Ueda
Toshiaki Kuriyama
Akio Naka
Hideyuki Nishibayashi
Application Number:
JP2000273624A
Publication Date:
April 15, 2002
Filing Date:
September 08, 2000
Export Citation:
Assignee:
Nippon Shokubai Co., Ltd.
International Classes:
C08J3/00; (IPC1-7): C08J3/00
Domestic Patent References:
| JP11199603A |
Attorney, Agent or Firm:
Takehiko Matsumoto