| abstract |
A waterborne pigmented paper or paperboard coating composition containing as pigment 50% to 100%, by weight based on pigment weight, calcium carbonate and from 1% to 25%, as dry weight based on pigment weight, of an aqueous polymeric dispersion including (a) 95-25% by weight, based on the weight of the solids of the aqueous polymeric dispersion, of a first emulsion polymer having an average particle diameter of 150 to 3000 nanometers and (b) 5-75% by weight, based on the weight of the solids of the aqueous polymeric dispersion, of a second emulsion polymer having an average particle diameter of 40 to 600 nanometers wherein the ratio of the average particle diameter of the first emulsion polymer to the average particle diameter of the second emulsion polymer is from 1.2 to 60, wherein at least the first emulsion polymer particles, when dry, contain at least one void, and wherein the first emulsion polymer is prepared in the presence of the second emulsion polymer or the second emulsion polymer is prepared in the presence of the first emulsion polymer is provided, as is a method for improving the sheet gloss of paper or paperboard coated with the coating composition. |