MICRO SPHERES Russian patent published in 2011 - IPC B01J13/14 D06N3/00 D21H21/54 

FIELD: process engineering.

SUBSTANCE: invention relates to thermally expanding thermoplastic microspheres and their application. Said microspheres comprise polymer shell made from ethylenically unsaturated monomers that encapsulate propellent. Ethylenically unsaturated monomers comprise up to 40-70 wt % of acrylonitrile and 5-40 wt % methylacrylonitrile, and 10-50 wt % of monomers selected from the group including acrylates, methacrylic esters and mixes thereof. Said propellent comprises at least one agent selected from the group including methane, ethane, propane, isobutene, n-butane and neopentane.

EFFECT: higher foaming capacity, expansivity and chemical resistance, absence of halogen-containing monomers.

21 cl, 6 tbl, 25 ex