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

FIELD: technological processes.

SUBSTANCE: invention relates to thermoplastic thermally expanding microspheres and their application. Microspheres contain a polymer shell made of monomers with ethylene unsaturation that encapsulates a propellant. Monomers with ethylene unsaturation contain from 20 to 80 wt % of acrylonitrile, from 20 to 80 wt % of monomers selected from the group that consists of acrylic acid ethers, from 0 to 10 wt % of methacrylonitrile, from 0 to 40 wt % of monomers selected from the group that consists of methacrylic acid ethers. The total quantity of acrylonitrile and acrylic acid ethers makes from 50 to 100 wt % as monomers with ethylene unsaturation. The propellant contains at least one representative selected from the group of methane, ethane, propane, isobutane, n-butane and isopentane.

EFFECT: microspheres have high ability of foaming, low T_start without high quantities of halogen-containing monomers, resistance to chemicals and high transparency.

22 cl, 8 tbl, 28 ex