PROBLEM TO BE SOLVED: To obtain an amphoteric hollow polymer particle having good opacity, whiteness, water absorbency, ink transfer properties, etc., and esp. useful for a paper coating compsn. by forming an at least three-layer-structured particle which has a core polymer formed from an acid-group-contg. monomer and contg. voids and a surface layer polymer having functional groups exhibiting cationic properties at a specified pH. ;SOLUTION: This particle comprises a core polymer formed by copolymerizing 10-50 wt.% acid-group-contg. monomer (A) and 90-50 wt.% monoethylenically unsatd. monomer copolymerizable therewith (B), an intermediate layer polymer formed by homopolymerizing monomer B or copolymerizing 88 wt.% or higher monomer B and 12 wt.% or lower monomer A, and an outer layer polymer formed by homopolymerizing monomer B or copolymerizing 97 wt.% or higher monomer B and 3 wt.% or lower monomer A, contains voids formed by partially neutralizing the acid groups of the core polymer, and has functional groups exhibiting cationic properties at a pH of 3-8 on the particle surface.;COPYRIGHT: (C)1998,JPO
展开▼
