US Patent 10184062 Paper coating composition

The present invention relates to a coating composition comprising an aqueous dispersion of a binder and first and second core-shell polymer particles having aqueous neutralized acid cores, wherein the dry bulk density of the first core-shell polymer particles is in the range of 0.25 to 0.5 g/mL; and the dry bulk density of the second core-shell polymer particles is in the range of 0.30 to 0.90 g/mL. The composition of the present invention is useful as an undercoat layer for a thermosensitive recording material.