HEAT-EXPANDABLE MICROCAPSULES

摘要

The invention aims at providing heat-expandable microcapsules capable of being expanded at low temperature and giving expanded microcapsules which little shrink even at high temperature. The invention relates to heat-expandable microcapsules comprising a shell polymer and a volatile expanding agent component which gasifies at a temperature not higher than the softening point of the shell polymer, wherein the shell polymer comprises at least 70 wt% of a nitrile monomer component with the acrylonitrile content of the nitrile monomer component ranging from 40 to 85 wt%, and the volatile expanding agent component contains at least 30 wt% of a volatile expanding agent having a branched-chain structure or a cyclic structure.