An aqueous dispersion of a multistage polymer, wherein the multistage polymer comprises: a first polymer comprising as polymerized units, based on the weight of the first polymer, from 2.1% to 10% by weight of diacetone (meth)acrylamide, a hydroxy-functional (meth)acrylic acid alkyl ester, or mixtures thereof, from 2.8% to 10% by weight of a phosphorous-containing acid monomer, from 75% to 92% by weight of a hydrophilic (meth)acrylic acid alkyl ester having a Hansch value < 2.20, and from 0 to 3.8% by weight of an α, β-ethylenically unsaturated carboxylic acid; wherein the first polymer has a number average molecular weight of from 3,000 to 100,000 as determined by Gel Permeation Chromatography analysis using a polystyrene standard; and a second polymer comprising as polymerized units, based on the weight of the second polymer, from 50% to 100% by weight of a hydrophobic (meth)acrylic acid alkyl ester having a Hansch value ≥ 2.20, from 0 to 10% by weight of a carbonyl-containing functional monomer, and from 0 to 50% by weight of a hydrophilic monomer having a Hansch value < 2.20; wherein the second polymer has a glass transition temperature at least 40°C lower than that of the first polymer, wherein the glass transition temperature is calculated using the Fox equation,; wherein Hansch values are determined by the method described by A.J. Leo in Chem. Rev., Volume 93, Issue No. 4, page 1281; and wherein the weight ratio of the first polymer to the second polymer is from 25:75 to 50:50. a first polymer comprising as polymerized units, based on the weight of the first polymer, from 2.1% to 10% by weight of diacetone (meth)acrylamide, a hydroxy-functional (meth)acrylic acid alkyl ester, or mixtures thereof, from 2.8% to 10% by weight of a phosphorous-containing acid monomer, from 75% to 92% by weight of a hydrophilic (meth)acrylic acid alkyl ester having a Hansch value < 2.20, and from 0 to 3.8% by weight of an α, β-ethylenically unsaturated carboxylic acid; wherein the first polymer has a number average molecular weight of from 3,000 to 100,000 as determined by Gel Permeation Chromatography analysis using a polystyrene standard; and from 2.1% to 10% by weight of diacetone (meth)acrylamide, a hydroxy-functional (meth)acrylic acid alkyl ester, or mixtures thereof, from 2.8% to 10% by weight of a phosphorous-containing acid monomer, from 75% to 92% by weight of a hydrophilic (meth)acrylic acid alkyl ester having a Hansch value < 2.20, and from 0 to 3.8% by weight of an α, β-ethylenically unsaturated carboxylic acid; wherein the first polymer has a number average molecular weight of from 3,000 to 100,000 as determined by Gel Permeation Chromatography analysis using a polystyrene standard; and a second polymer comprising as polymerized units, based on the weight of the second polymer, from 50% to 100% by weight of a hydrophobic (meth)acrylic acid alkyl ester having a Hansch value ≥ 2.20, from 0 to 10% by weight of a carbonyl-containing functional monomer, and from 0 to 50% by weight of a hydrophilic monomer having a Hansch value < 2.20; wherein the second polymer has a glass transition temperature at least 40°C lower than that of the first polymer, wherein the glass transition temperature is calculated using the Fox equation,; wherein Hansch values are determined by the method described by A.J. Leo in Chem. Rev., Volume 93, Issue No. 4, page 1281; and wherein the weight ratio of the first polymer to the second polymer is from 25:75 to 50:50. from 50% to 100% by weight of a hydrophobic (meth)acrylic acid alkyl ester having a Hansch value ≥ 2.20, from 0 to 10% by weight of a carbonyl-containing functional monomer, and from 0 to 50% by weight of a hydrophilic monomer having a Hansch value < 2.20; wherein the second polymer has a glass transition temperature at least 40°C lower than that of the first polymer, wherein the glass transition temperature is calculated using the Fox equation,; wherein Hansch values are determined by the method described by A.J. Leo in Chem. Rev., Volume 93, Issue No. 4, page 1281; and wherein the weight ratio of the first polymer to the second polymer is from 25:75 to 50:50.