Coating composition and coated paper and coated paperboard

Abstract

A coating composition may include kaolin having a shape factor less than about 70 and calcium carbonate, wherein less than about 90% by weight and greater than about 60% by weight of particles of the calcium carbonate have an equivalent spherical diameter (esd) less than 2 microns. The coating composition may include a thickener present in an amount ranging from about 0.1% to about 0.9% by active dry weight of the composition. A coating composition may include kaolin having a shape factor less than about 70 and calcium carbonate having a mean particle size (d 50 ) of at least about 2.4 microns and a steepness factor of at least about 30. The coating composition may be a paper basecoat composition or a paperboard basecoat composition. A paper or paperboard product may include the coating composition on at least one surface of the paper product or paperboard product.

1 . A coating composition comprising:
 kaolin having a shape factor less than about 70; and   calcium carbonate, wherein less than about 90% by weight and greater than about 60% by weight of particles of the calcium carbonate have an esd less than 2 microns.   
     
     
         2 . The composition of  claim 2 , further comprising a thickener. 
     
     
         3 . The composition of  claim 2 , wherein the thickener is present in an amount ranging from about 0.1% to about 0.9% by active dry weight of the composition. 
     
     
         4 - 5 . (canceled) 
     
     
         6 . The composition of  claim 2 , wherein the thickener is selected from the group consisting of alkali-soluble emulsion polyacrylate thickeners, hydrophobically-modified alkali-soluble emulsion polyacrylate thickeners, and CMC (carboxymethyl celluloses) thickeners. 
     
     
         7 . The composition of  claim 1 , wherein less than about 30% by weight of the kaolin has an esd less than about 0.25 micron. 
     
     
         8 - 10 . (canceled) 
     
     
         11 . The composition of  claim 1 , wherein less than about 80% by weight of the kaolin has an esd less than about 1 micron. 
     
     
         12 . (canceled) 
     
     
         13 . The composition of  claim 1 , wherein less than about 80% by weight and greater than about 60% by weight of the particles of the calcium carbonate have an esd less than 2 microns. 
     
     
         14 - 17 . (canceled) 
     
     
         18 . A paperboard product comprising the coating composition of  claim 1  on at least one surface of the paperboard product. 
     
     
         19 . A coating composition comprising:
 kaolin having a shape factor less than about 70; and   calcium carbonate having a d 50  of at least about 2.4 microns and a steepness factor of at least about 30.   
     
     
         20 . The composition of  claim 19 , further comprising a thickener. 
     
     
         21 . The composition of  claim 20 , wherein the thickener is present in an amount ranging from about 0.1% to about 0.9% by active dry weight of the composition. 
     
     
         22 - 23 . (canceled) 
     
     
         24 . The composition of  claim 20 , wherein the thickener is selected from the group consisting of alkali-soluble emulsion polyacrylate thickeners, hydrophobically-modified alkali-soluble emulsion polyacrylate thickeners, and CMC (carboxymethyl celluloses) thickeners. 
     
     
         25 . The composition of  claim 19 , wherein less than about 30% by weight of the kaolin has an esd less than about 0.25 micron. 
     
     
         26 - 28 . (canceled) 
     
     
         29 . The composition of  claim 19 , wherein less than about 80% by weight of the kaolin has an esd less than about 1 micron. 
     
     
         30 . (canceled) 
     
     
         31 . The composition of  claim 19 , wherein the calcium carbonate has a d 50  of at least about 2.6 microns. 
     
     
         32 - 33 . (canceled) 
     
     
         34 . The composition of  claim 19 , wherein the calcium carbonate has a steepness factor of at least about 32. 
     
     
         35 - 41 . (canceled) 
     
     
         42 . A paperboard product comprising the coating composition of  claim 19  on at least one surface of the paperboard product.