The present invention relates to a composition comprising an aqueous dispersion of multiphase polymer particles comprising first polymer particles having a Tg of less than 30° C. and second polymer particles having a Tg in the range of from 100° C. to 110° C., wherein the second polymer particles are phase separated from and occluded within the first polymer particles; wherein the number average molecular weight (Mn) of the multiphase polymer particles is in the range of from 9,000 to 25,000 g/mole; and wherein the second polymer particles comprise at least 95 weight percent methyl methacrylate. The composition of the present invention is useful in a formulation that can be used to prepare a water-resistant blister free LASD coating with little or no surface defects.