| 摘要 |
The invention relates to block copolymers that are obtained by polymerizing a mixture of olefinically unsaturated monomers consisting of: a) 0 to 40 weigh t % of one or more ethylenically unsaturated ester compounds of formula (I), wherein R represents hydrogen or methyl, R1 represents a linear or branched alkyl radical having 1 to 5 carbon atoms, R2 and R3 independently represent hydrogen or a group of formula COOR', wherein R1' represents hydrogen or an alkyl group having 1 to 5 carbon atoms; b) 10 to 98 weight % of one or more ethylenically unsaturated ester compounds of formula (II), wherein R represents hydrogen or methyl, R4 represents a linear or branched alkyl radical having 6 to 15 carbon atoms, R5 and R6 independently represent hydrogen or a group of formula -COOR'', wherein R'' represents hydrogen or a n alkyl group having 6 to 15 carbon atoms, c) 0 to 80 weight % of one or more ethylenically unsaturated ester compounds of formula (III), wherein R represents hydrogen or methyl, R7 represents a linear or branched alkyl radical having 16 to 30 carbon atoms, R8 and R9 independently represent hydrogen or a group of formula -COOR''', wherein R''' represents hydrogen or an alkyl group having 16 to 30 carbon atoms, d) 0 to 50 weight % of comonomers, whereby the mixture of ethylenically unsaturated monomers is discontinuously modified during chain growth with the purpose of obtaining block copolymers whose blocks have at least 30 monomer units. The novel copolymers are used as setting point improvers.
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