Wet-strength corrugated fiberboard

Abstract

The present invention relates to single face or double faced corrugated fiberboard comprising one or more corrugated plies, wherein at least one of the linerboard plies or corrugated plies is a paper-film assembly comprising: i) a 30 to 600 g/m 2 grammage papery material of construction, ii) a biodegradable polymeric coating from 1 to 100 μm in thickness. More particularly, the present invention relates to single face or double faced and/or corrugated fiberboard comprising one or more corrugated plies, wherein at least one of the linerboard plies or corrugated plies is a paper-film assembly comprising: i) a 30 to 600 g/m 2 grammage papery material of construction as outer layer, ii) a biodegradable polymeric coating from 1 to 100 μm in thickness as interlayer, and iii) a 30 to 600 g/m 2 grammage papery material of construction as inner layer. The present invention further relates to methods of producing this corrugated fiberboard.

1 .- 7 . (canceled) 
     
     
         8 . A method of producing a paper film assembly for the manufacture of corrugated fiberboard that includes one or more linerboard plies and one or more corrugated plies, the method comprising laminating preheated webs of paper with a polymeric film with or without a lamination adhesive,
 wherein the paper film assembly comprises;
 i) a 30 to 600 g/m 2  grammage papery material of construction as a layer, and 
 ii) a biodegradable polymeric coating with a thickness from 1 to 100 μm. 
   
     
     
         9 . The method of  claim 8 , wherein the laminating includes the lamination adhesive. 
     
     
         10 . The method of  claim 8 , wherein the grammage papery material of construction is 50 to 150 g/m 2 , and the thickness of the biodegradable polymeric coating is from 10 to 60 μm. 
     
     
         11 . The method of  claim 8 , wherein the polymeric coating is selected from an aliphatic/aromatic polyester prepared from butanediol, terephthalic acid or one or more C 6 -C 18  dicarboxylic acids. 
     
     
         12 . The method of  claim 8 , wherein the polymeric coating is a copolymer mixture comprising:
 30% to 50% by weight of a biodegradable, aliphatic-aromatic polyester;   70% to 50% by weight of one or more polymers selected from the group consisting of polylactic acid and polyhydroxyalkanoate; and   0% to 2% by weight of an epoxy-containing poly(meth)acrylate.   
     
     
         13 . The method of  claim 8 , wherein said layer i) comprises wastepaper in the range from 10 to 100%. 
     
     
         14 . A method of producing a paper film assembly for the manufacture of corrugated fiberboard that includes one or more linerboard plies and one or more corrugated plies, the method comprising laminating preheated webs of paper with a polymeric film with or without a lamination adhesive,
 wherein the paper film assembly comprises;
 i) a 30 to 600 g/m 2  grammage papery material of construction as an outer layer, 
 ii) a biodegradable polymeric coating with a thickness from 1 to 100 μm as an interlayer, and 
 iii) a 30 to 600 g/m 2  grammage papery material of construction as an inner layer. 
   
     
     
         15 . The method of  claim 14 , wherein the laminating includes the lamination adhesive. 
     
     
         16 . The method of  claim 14 , wherein the outer layer, grammage papery material of construction is 50 to 150 g/m 2 , the thickness of the biodegradable polymeric coating is from 10 to 60 μm, and the inner layer, grammage papery material of construction is 50 to 150 g/m 2    
     
     
         17 . The method of  claim 14 , wherein the polymeric coating is selected from an aliphatic/aromatic polyester prepared from butanediol, terephthalic acid or one or more C 6 -C 18  dicarboxylic acids. 
     
     
         18 . The method of  claim 14 , wherein the polymeric coating is a copolymer mixture comprising:
 30% to 50% by weight of a biodegradable, aliphatic-aromatic polyester;   70% to 50% by weight of one or more polymers selected from the group consisting of polylactic acid and polyhydroxyalkanoate; and   0% to 2% by weight of an epoxy-containing poly(meth)acrylate.   
     
     
         19 . The method of  claim 14 , wherein said layer i) and said layer iii) comprises wastepaper in the range from 10 to 100%. 
     
     
         20 . The method of  claim 8 , wherein the biodegradable polymeric coating is applied as a hot melt with an extrusion coating. 
     
     
         21 . The method of  claim 20 , wherein the polymeric coating as a hotmelt is pumped from a stock reservoir vessel preheated to a temperature from 150 to 200° C. into a wind-slot die as the paper web travels directly past the die lip at a high rate of speed to provide coatings of from 1 to 5 g/m 2 . 
     
     
         22 . The method of  claim 14  wherein the biodegradable polymeric coating is applied as a hot melt in an extrusion coating. 
     
     
         24 . The method of  claim 22 , wherein the polymeric coating as a hotmelt is pumped from a stock reservoir vessel preheated to a temperature from 150 to 200° C. into a wind-slot die as the paper web travels directly past the die lip at a high rate of speed to provide coatings of from 1 to 5 g/m 2 .