| abstract |
The hydrophobe-containing alkali soluble or swellable copolymer thickener provides aqueous compositions with constant or increased viscosity at temperatures approaching 120oC. The copolymer comprises an emulsion polymerization product of: (A) 0.1 to 25 weight percent of an ethylenically unsaturated copolymerizable surfactant monomer of formula (I) M(EO)x(PO)y(BO)zOR1 having a cloud point of 65 to 95oC; (B) 20 to 70 weight percent of an a,b-ethylenically unsaturated monocarboxylic acid monomer of formula CH2=C(R2)-COOH (C) 10 to 70 weight percent of a nonionic a,b-ethylenically unsaturated monomer of formula CH2 = CR4R5 In the above formulae: M is a residue of an ethylenically unsaturated carboxylic acid, ethylenically unsaturated dicarboxylic acid or a copolymerizable isocyanate; EO is an ethylene oxide unit; PO is a propylene oxide unit; BO is a butylene oxide unit; x is from 10 to 45; y is from 0 to 35; z is from 0 to 35; provided that x + y + z is from 20 to 45; R1 is alkyl, alkylene, cycloalkyl, cycloalkylene or arylalkyl group wherein the alkyl group has 1 to 30 carbon atoms; R2 is hydrogen, an alkyl group having 1 to 4 carbon atoms or -CH2COOR3; R3 is hydrogen or an alkyl group having 1 to 4 carbon atoms; R4 is hydrogen, methyl or Cl; R5 is CN, Cl, -COOR6, -C6H4R7, -CH=CH2, -OC(O)R" or -C(O)-NH2; R6 is hydrogen, Cl, Br or an alkyl group having 1 to 4 carbon atoms; R7 is an alkyl group having 1 to 12 carbon atoms or a hydroxyalkyl group having 2 to 8 carbon atoms and R8 is an alkyl group having 1 to 8 carbon atoms. |