Graphene-coated paper or paperboard

Abstract

The present disclosure provides a coated paper product comprising: —a paper or paperboard substrate: —a barrier coating, wherein the barrier coating comprises graphene and a polyolefin copolymer bearing carboxylic acid moieties, wherein the polyolefin copolymer bearing carboxylic acid moieties preferably is ethylene-acrylic acid copolymer (EAA) or ethylene-methacrylic-acid-copolymer (EMAA) or maleic acid ethylene copolymer (MAE), and wherein the graphene content in the barrier coating is 0.3-3 wt %. There is also provided a coated paper product comprising high surface area graphite flakes having an average particle size of 2-7 μm instead of the graphene.

1 . A coated paper product comprising:
 a paper or paperboard substrate;   a barrier coating, wherein the barrier coating comprises graphene and a polyolefin copolymer bearing carboxylic acid moieties,   wherein the graphene content in the barrier coating is 0.3-3 wt %.   
     
     
         2 . The coated paper product of  claim 1 , wherein the coat weight of the barrier coating is at least 4 g/m 2 . 
     
     
         3 . The coated paper product of  claim 1 , wherein the coated paper product comprises a pre-coating between the substrate and the barrier coating. 
     
     
         4 . The coated paper product of  claim 3 , wherein the pre-coating comprises a polyolefin copolymer bearing carboxylic acid moieties or vinyl acetate acrylate copolymer (VAcA) or styrene-acrylate copolymer (SA) or styrene-butadiene copolymer (SB). 
     
     
         5 . The coated paper product of  claim 3 , wherein the coat weight of the pre-coating is at least 4 g/m 2 . 
     
     
         6 . The coated paper product of  claim 1 , wherein the graphene content in the barrier coating is 0.5-2 wt %, based on the dry weight of the barrier coating. 
     
     
         7 . The coated paper product of  claim 1 , wherein the water vapor transmission rate (WVTR) measured according to ISO 15106-1 at 38° C. and 90% relative humidity (RH) of the coated paper product is below 65 g/(m 2  day). 
     
     
         8 . The coated paper product of  claim 1 , wherein the paper product is heat-sealable. 
     
     
         9 . A packaging comprising the coated paper product according to  claim 1 . 
     
     
         10 . A method of producing a coated paper product comprising the steps of:
 providing a paper or paperboard substrate; and   coating the substrate with a barrier coating, wherein the barrier coating comprises graphene and a polyolefin copolymer bearing carboxylic acid moieties, wherein   wherein the graphene content in the barrier coating is 0.3-3 wt %.   
     
     
         11 . The method of  claim 10 , wherein the barrier coating is applied in-line. 
     
     
         12 . The method of  claim 10 , further comprising the step of:
 coating the substrate with a pre-coating prior to coating with the barrier coating so that the pre-coating is arranged between the substrate and the barrier coating in the coated paper product.   
     
     
         13 . The method of  claim 12  comprising drying between the pre-coating step and the barrier-coating step. 
     
     
         14 . The method of  claim 12 , wherein the pre-coating is applied in-line. 
     
     
         15 . (canceled) 
     
     
         16 . A coated paper product comprising:
 a paper or paperboard substrate;   a barrier coating, wherein the barrier coating comprises high surface area graphite flakes having an average particle size of 2-7 μm as determined by laser diffraction and a polyolefin copolymer bearing carboxylic acid moieties.   
     
     
         17 . The coated paper of  claim 16 , wherein the particle size D90 of the high surface area graphite flakes is 6-10 μm. 
     
     
         18 . The coated paper of  claim 16 , wherein the surface area of the high surface area graphite flakes is 15-70 g/m 2 . 
     
     
         19 . The coated paper of  claim 16 , wherein the content of high surface area graphite flakes in the barrier coating is 5-30 wt. %, such as 7-28 wt. %. 
     
     
         20 . The coated paper of  claim 16 , wherein the coat weight of the barrier coating is at least 4 g/m 2 . 
     
     
         21 . A packaging comprising the coated paper product according to  claim 16 . 
     
     
         22 . A method of producing a coated paper product comprising the steps of:
 providing a paper or paperboard substrate; and   coating the substrate with a barrier coating, wherein the barrier coating comprises high surface area graphite flakes having an average particle size of 2-7 μm and a polyolefin copolymer bearing carboxylic acid moieties.   
     
     
         23 . (canceled) 
     
     
         24 . The coated paper product of  claim 1 , wherein the polyolefin copolymer bearing carboxylic acid moieties is ethylene-acrylic acid copolymer (EAA) or ethylene-methacrylic-acid-copolymer (EMAA) or maleic acid ethylene copolymer (MAE). 
     
     
         25 . The method of  claim 10 , wherein the polyolefin copolymer bearing carboxylic acid moieties is ethylene-acrylic acid copolymer (EAA) or ethylene-methacrylic-acid-copolymer (EMAA) or maleic acid ethylene copolymer (MAE). 
     
     
         26 . The coated paper product of  claim 16 , wherein the polyolefin copolymer bearing carboxylic acid moieties is ethylene-acrylic acid copolymer (EAA) or ethylene-methacrylic-acid-copolymer (EMAA) or maleic acid ethylene copolymer (MAE). 
     
     
         27 . The method of  claim 22 , wherein the polyolefin copolymer bearing carboxylic acid moieties is ethylene-acrylic acid copolymer (EAA) or ethylene-methacrylic-acid-copolymer (EMAA) or maleic acid ethylene copolymer (MAE).