| 摘要 |
PROBLEM TO BE SOLVED: To provide expandable microspheres with high expansion capability and low expansion start temperature, which do not include a high amount of halogen-containing monomers and which preferably have high resistance to chemicals.SOLUTION: Thermally expandable thermoplastic microspheres comprise a polymer shell made from ethylenically unsaturated monomers encapsulating a propellant such as propane. In the thermally expandable thermoplastic microspheres, the ethylenically unsaturated monomers comprise 20 to 80 wt.% of acrylonitrile and 1 to 70 wt.% of a vinyl ether having only one carbon-to-carbon double bond, in which the total amount of acrylonitrile and the vinyl ether having only one carbon-to-carbon double bond is 30 to 100 wt.% of the ethylenically unsaturated monomers, and in which the vinyl ether is an alkyl vinyl ether.SELECTED DRAWING: None |
