Process for preparing a thermo-expandable microspheres
AssigneeMatsumoto Yushi-Seiyaku Co., Ltd.
InventorsNobukazu Nakayama, Sueo Kida
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Abstract
Microspheres, the blowing agent of which is microencapsulated with a thermoplastics having an acrylonitrile moiety, are prepared. Acrylonitrile monomer remaining therein is eliminated from the microspheres by cyanoethylation. The microspheres have an excellent solvent-resistance and an expansibility hardly changeable with time but no harmfulness attributed to the acrylonitrile monomer.
Claims5
A process for preparing a thermo-expandable microsphere substantially free of acrylonitrile monomer which comprises microencapsulating a blowing agent with a thermoplastic polymer having an acrylonitrile moiety as one of ingredients, wherein the blowing agent becomes gaseous below a softening temperature of the thermoplastic polymer, and subjecting the microencapsulated product to cyanoethylation to eliminate the acrylonitrile monomer remaining in the microencapsulated product.
Dependencies are inferred from the claim text.