Method to reduce back trap offset print mottle

Abstract

A paper and paperboard material comprising a paper or paperboard substrate, a basecoat layer on at least one surface of substrate and topcoat on a surface of the basecoat, said topcoat comprising one or more pigments dispersed in one or more binders and said basecoat comprising low density thermoplastic particles dispersed in one or more binders. The basecoat is compressible which reduces back trap print mottle in offset printed images.

1 . A paper and paperboard material comprising a paper or paperboard substrate, a basecoat layer on at least one surface of substrate and topcoat on a surface of the basecoat, said topcoat comprising one or more pigments dispersed in one or more binders and said basecoat comprising low density thermoplastic particles dispersed in one or more binders.  
   
   
       2 . The material of  claim 1 , wherein the low density thermoplastic particles are hollow particles or binders having a particle size that is at least about 175 nm.  
   
   
       3 . The material of  claim 1 , wherein the low density thermoplastic particles are binders having a particle size that at least about 175 nm.  
   
   
       4 . The material of  claim 2 , wherein the low density thermoplastic particles are hollow polymer plastic pigments.  
   
   
       5 . The material of  claim 1 , wherein the low density thermoplastic particles are present in an amount from about 3 to about 30% by weight of the basecoat composition.  
   
   
       6 . The material of  claim 3 , wherein the low density thermoplastic particles are present in an amount from about 3 to about 20% by weight of the basecoat composition.  
   
   
       7 . The material of  claim 6 , wherein the low density thermoplastic particles are present in an amount from about 3 to about 15% by weight of the basecoat composition.  
   
   
       8 . The material of  claim 7 , wherein the low density thermoplastic particles are present in an amount from about 4 to about 7% by weight of the basecoat composition.  
   
   
       9 . The material of  claim 3 , wherein the binder has a particle size that is at least about 175 nm.  
   
   
       10 . The material of  claim 1 , wherein the binder has a particle size from about 175 to about 300 nm.  
   
   
       11 . The material of  claim 1 , wherein the binder has a particle size that is from about 185 nm to about 300 nm.  
   
   
       12 . The material of  claim 2 , wherein the low density thermoplastic particles are present in an amount from about 3 to about 30% by weight of the basecoat composition.  
   
   
       13 . The material of  claim 10 , wherein the low density thermoplastic particles are present in an amount from about 3 to about 20% by weight of the basecoat composition.  
   
   
       14 . The material of  claim 11 , wherein the low density thermoplastic particles are present in an amount from about 3 to about 15% by weight of the basecoat composition.  
   
   
       15 . The material of  claim 12 , wherein the low density thermoplastic particles are present in an amount from about 4 to about 7% by weight of the basecoat composition.  
   
   
       16 . The material of  claim 1 , wherein the basecoat further comprises an inorganic pigment having a rosette structure.  
   
   
       17 . The material of  claim 12 , wherein the low density thermoplastic particles are present in an amount from about 3 to about 30% by weight of the basecoat composition, and the inorganic pigment is present in an amount from about 5 to about 50% by weight of the basecoat composition.  
   
   
       18 . The material of  claim 12 , wherein the binder has a particle size that is at least 175 nm.  
   
   
       19 . The material of  claim 1  having 2 nd  cyan scanner mottle which is about 20% less than the 2 nd  cyan scanner mottle of a similar material having the same characteristics except for the presence of low density thermoplastic particles in the basecoat.  
   
   
       20 . The material of  claim 17  having 2 nd  cyan scanner mottle which is about 40% less than the 2 nd  cyan scanner mottle of a similar material having the same characteristics except for the presence of low density thermoplastic particles in the basecoat.  
   
   
       21 . The material of  claim 18  having 2 nd  cyan scanner mottle which is about 60% less than the 2 nd  cyan scanner mottle of a similar material having the same characteristics except for the presence of low density thermoplastic particles in the basecoat.  
   
   
       22 . The material of  claim 1  having 2 nd  Cyan Tobias mottle which is about 5% less than the 2 nd  Cyan Tobias mottle of a similar material having the same characteristics except for the presence of low density thermoplastic particles in the basecoat.  
   
   
       23 . The material of  claim 20  having 2 nd  Cyan Tobias mottle which is about 10% less than the 2 nd  Cyan Tobias mottle of a similar material having the same characteristics except for the presence of low density thermoplastic particles in the basecoat.  
   
   
       24 . The material of  claim 21  having 2 nd  Cyan Tobias mottle which is about 15% less than the 2 nd  Cyan Tobias mottle of a similar material having the same characteristics except for the presence of low density thermoplastic particles in the basecoat.  
   
   
       25 . The material of  claim 1  having Parker print Surface which is about 10% less than the Parker Print Surface of a similar material having the same characteristics except for the presence of low density thermoplastic particles in the basecoat.  
   
   
       26 . The material of  claim 23  having Parker print Surface which is about 20% less than the Parker Print Surface of a similar material having the same characteristics except for the presence of low density thermoplastic particles in the basecoat.  
   
   
       27 . The material of  claim 24  having Parker print Surface which is about 30% less than the Parker Print Surface of a similar material having the same characteristics except for the presence of low density thermoplastic particles in the basecoat.  
   
   
       28 . A method comprising: 
 a) applying a basecoat composition to a paper substrate, wherein the basecoat comprises a binder and low density thermoplastic particles, and    b) applying a topcoat composition comprising one or more pigments dispersed in one or more binders over the basecoat.