Starch-coated paper or paperboard

Abstract

There is provided a product comprising a paper substrate and a first coating provided on the substrate, wherein the first coating comprises starch and calcium carbonate pigment.

1 . A product comprising a paper substrate having a printing side and a reverse side, a first coating provided on the reverse side and a second coating provided on the printing side, wherein the first coating comprises starch and calcium carbonate pigment and the dry weight ratio of starch to calcium carbonate in the first coating is between 21:100 and 500:100. 
     
     
         2 . The product of claim  3 , wherein the dry weight ratio of starch to calcium carbonate in the first coating is between 25:100 and 500:100. 
     
     
         3 . The product of claim  4 , wherein the dry weight ratio of starch to calcium carbonate in the first coating is between 33:100 and 300:100. 
     
     
         4 . The product of claim  4 , wherein the dry weight ratio of starch to calcium carbonate in the first coating is between 50:100 and 500:100. 
     
     
         5 . The product of claim  6 , wherein the dry weight ratio of starch to calcium carbonate in the first coating is between 150:100 and 500:100. 
     
     
         6 . The product of  claim 1 , wherein starch and calcium carbonate pigment constitute at least 80% of the dry weight of the first coating. 
     
     
         7 . The product of  claim 1 , wherein the coat weight of the first coating is between 0.5 and 4.5 g/m 2 . 
     
     
         8 . The product of  claim 1 , wherein the paper substrate is a multi-layered linerboard or paperboard having a grammage according to ISO 536:2019 of 120-500 g/m 2 . 
     
     
         9 . The product of  claim 8 , wherein the paper substrate is liquid packaging board. 
     
     
         10 . The product of  claim 1 , wherein the second coating comprises pigment and a polymeric binder. 
     
     
         11 . The product of  claim 10 , wherein the dry weight ratio of polymeric binder to pigment in the second coating is between 10:100 and 20:100. 
     
     
         12 . The product of  claim 1 , wherein the coat weight of the second coating is at least 100% higher than the coat weight of the first coating. 
     
     
         13 . The product of  claim 1 , further comprising a polyolefin layer, such as a polyethylene (PE) layer, provided on the first coating. 
     
     
         14 . The product of  claim 6 , wherein starch and calcium carbonate pigment constitute at least 95% of the dry weight of the first coating. 
     
     
         15 . The product of  claim 7 , wherein the coat weight of the first coating is between 0.8 and 2.0 g/m 2 . 
     
     
         16 . The product of  claim 8 , wherein the paper substrate is a multi-layered linerboard or paperboard having a grammage according to ISO 536:2019 of 120-300 g/m 2 . 
     
     
         17 . The product of  claim 13 , wherein the polyolefin layer is a polyethylene (PE) layer.