Title:
PRODUCTION OF POLYMER PARTICLE HAVING GRADIENT REFRACTIVE INDEX
Document Type and Number:
Japanese Patent JP3298215
Kind Code:
B2
Abstract:
PURPOSE: To produce polymer particles in a high good productivity particularly of a particle diameter of 50-500μm whose refractive index gradually changes aling the direction from the core to the periphery.
CONSTITUTION: A polymerization process comprising suspension-polymerizing a radical-polymerizing monomer (A) in the presence of an oil-soluble polymerization initiator in an aqueous medium, substantially continuously adding a radical- polymerizable monomer (B) to the reaction system when the conversion is between 70 and 95%, and continuing and completing the polymerization without adding any fresh polymerization initiator to the system, wherein the ratio of the amount of monomer A to that of monomer B is 1/3 to 3, and the difference between the refractive indices of polymers obtained by separately polymerizing monomers A and B is 0.01 or greater.
Inventors:
Kazuhiro Yamazaki
Application Number:
JP6794793A
Publication Date:
July 02, 2002
Filing Date:
March 26, 1993
Export Citation:
Assignee:
Sumitomo Chemical Co., Ltd.
International Classes:
C08F2/18; C08L25/02; C08L33/06; G02B1/04; G02B5/00; G02B5/02; (IPC1-7): C08F2/18; G02B1/04; G02B5/00; G02B5/02
Attorney, Agent or Firm:
Takashi Kuboyama (1 person outside)