Aqueous dispersion of multistage acrylic microspheres

A composition comprising an aqueous dispersion of polymeric microspheres comprising a shell and a core, wherein:

• a) the polymeric microspheres have a D50 particle size in the range of from 8 μm to 15 μm, and wherein the microspheres have a coefficient of variation in the range of from 30% to 60%;
• b) the shell comprises at least 90% by weight structural units of methyl methacrylate, and has a surface Young's modulus at 25° C. in the range of from 750 MPa to 1250 MPa, wherein the shell has a Tg, in the range of from 95° C. and 110° C.;
• c) the core comprises i) from 0.5 to 20 weight percent structural units of a hydrophobic monomer which is 2-ethylhexyl acrylate, lauryl methacrylate, stearyl methacrylate, or behenyl methacrylate;
• ii) from 1 to 6 weight percent structural units of allyl methacrylate;
• iii) from 80 to 98 weight percent structural units of n-butyl acrylate;
• and iv) less than 4.5 weight percent structural units of a carboxylic acid monomer;
• wherein the core has a Young's modulus at 25° C. in the range of from 1 MPa to less than 20 MPa;
• d) the weight-to-weight ratio of the core to the shell is in the range of from 8.5:1.5 to 7.5:2.5;
• and
• e) the shell thickness of the polymeric microspheres is in the range of from 0.2 μm to 1.0 μm.