| 摘要 |
PURPOSE:To obtain the titled fine particles excellent in uniformity of a particle size, exactness of sphericity and solvent resistance, by polymerizing a specified monomer mixture absorbed by crosslinked fine polymer particles in the presence of a water-soluble protective colloid. CONSTITUTION:A monomer mixture of 99-99.95wt% noncrosslinking monomer and 1-0.05wt% crosslinking monomer and, optionally, an emulsifier are dispersed in water and polymerized in the presence of a water-soluble polymerization initiator to obtain fine polymer particles (A) having a standard deviation of a particle diameter distribution <=0.5mum, a degree of swelling of 8-100 and a low crosslinking density. 100pts.wt. component A in an aqueous dispersion containing 2-50pts.wt. water-soluble high- molecular protective colloid (e.g., PVA of a degree of saponification of 70-90%) is allowed to absorb 100-3,000pts.wt. mixture of 10-50wt% hardly water-soluble crosslinking monomer (B) and 90-50wt% hardly water soluble noncrosslinking monomer (C), and the absorbed monomer mixture is polymerized in the presence of 0.1-3wt% oil-soluble polymerization initiator to obtain the titled fine particles of a particle diameter of 0.1-30mum and a standard deviation of a particle diameter distribution <=1mum.
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