Patent ID: 6951642

Claim:
A stable water-in-oil emulsion comprising: a vinyl polymer comprising anionic group-containing side chains and alkyl-Y-containing side chains, wherein Y is O or NR, wherein R is hydrogen or methyl, and wherein the alkyl group of the alkyl-Y-containing side chain has at least 4 carbon atoms on average in a cyclic, branched-, or straight-chain configuration and optionally includes one or more heteroatoms; an oil phase; and a water phase; wherein the vinyl polymer is insoluble or sparingly soluble in the water phase and is derived from at least three different monomers; wherein at least one monomer has a pKa of less than 4 and has the formula: wherein: X is O or NR 5 ; R 3 and R 5 are each independently hydrogen or methyl; R∝is a linear, branched, or cyclic alkylene, arylene, or aralkylene group optionally including one or more heteroatoms; A is (SO 3 ) x M, (SO 4 ) x M, (PO 3 ) x M, (PO 4 ) x M; x is 1 or 2; and M is selected from the group consisting of H, Na, K, Li, Ca, Mg, Zn, a protonated primary amine, a protonated secondary amine, a protonated tertiary amine, a quaternary amine, and combinations thereof; and further wherein at least two monomers have the formula: wherein; R 1 is hydrogen or methyl; and in one monomer, R 2 is a linear, branched, or cyclic alkyl group having 4 to 14 carbon atoms on average, optionally including one or more heteroatoms; and in the one monomer, R 2 is a linear, branched, or cyclic alkyl group having 15 to 22 carbon atoms on average, optionally including one or more heteroatoms.