METHOD OF MANUFACTURING THERMALLY EXPANDABLE MICROCAPSULE

摘要

PROBLEM TO BE SOLVED: To provide an efficient and simple method of manufacturing a thermally expandable microcapsule which has excellent heat resistance and solvent resistance in combination, hardly gives rise to shrinking and foam breaking even under heating conditions of a high temperature and long time and has excellent thermal inflation stability (foaming stability). SOLUTION: The method of manufacturing the thermally expandable microcapsule comprising microcapsulating a monomer component containing 55 to 75 wt.% acrylonitrile, 20 to 40 wt.% methacrylonitrile, 1 to 10 wt.% vinyl acetate, and 0.1 to 1 wt.% tetra- or higher functional crosslinking agent and a volatile inflating agent which turns to a gaseous state at a temperature below the softening point of the polymer obtained from the monomer component described above by polymerization under nitrogen pressurization.