Thermisch expandierbare Mikrokapseln, Verfahren zu ihrer Herstellung und Mikroballonen daraus hergestellt

摘要

A thermoplastic microcapsule which is softened by heat, has a good thermoexpandability, and can provide a microballoon which shows a high heat resistance after thermoexpanded comprises a shell and an expanding agent therein, said shell being made from a copolymer essentially consisting of a polymerizable monomer having two or more polymerizable double bonds and a monomer which can produce a homopolymer having a high glass transition temperature, and said expanding agent being vaporizable at a temperature lower than the softening temperature of the copolymer.