| abstract |
Graft copolymers (I) are claimed, comprising (a) 5-95 wt.% of a copolymer of 20-60 wt.% 1,3,5-triazine deriv. of formula (II) and 40-80 wt.% other vinyl comonomes as the base, grafted with (b) 5-95 wt.% of a polymer of styrene, alpha-methylstyrene, p-methylstyrene, (meth)acrylonitrile, 1-8C alkyl (meth)acrylates, maleimides, maleic anhydride, vinyl ether, vinyl ester, ethylene, methacrylamide, (meth)acrylic acid, styrene-sulphonic acid or a mixt. thereof; R = H or 1-2C alkyl. Pref., (I) contains 10-85 wt.% (a) and 90-15 wt.% (b). (a) are produced by aq. emulsion polymerisation of (II) with at least 2 comonomers such as styrene and MMA, etc., pref. using persulphate initiator; graft copolymerisation is pref. carried out in aq. emulsion using a mixt. of AN and/or MMA contg. 90-30 wt.% styrene. |