Low opacity paper packaging material

Abstract

Paper products and products comprising such paper products, such as packaging paper, are provided that are made from a fibrous web containing highly refined cellulose fibers. A paper product comprises a fibrous web comprising cellulose fibers, a transparency agent in contact with the fibrous web and comprising a bio-based was or oil and a heat-sealable composition in contact with the fibrous web and comprising a polymer comprising a polyester, a protein, a polysaccharide, a polysaccharide ester, a polysaccharide ether, or a polysaccharide ether ester. The cellulose fibers may have a Schopper-Riegler freeness value in the range of from about 60° SR to about 95° SR. The resulting product has a relatively low basis weight and a relatively low opacity.

What is claimed is: 
     
         1 . A paper product comprising:
 a fibrous web comprising cellulose fibers; and   a transparency agent in contact with the fibrous web and comprising a bio-based was or oil; and   a heat-sealable composition in contact with the fibrous web and comprising a polymer comprising a polyester, a protein, a polysaccharide, a polysaccharide ester, a polysaccharide ether, or a polysaccharide ether ester.   
     
     
         2 . The paper product of  claim 1 , wherein the transparency agent comprises a first coating in contact with a first or second surface of the fibrous web and the heat-sealable composition comprises a second coating in contact with a first or second surface of the fibrous web. 
     
     
         3 . The paper product of  claim 1 , wherein the transparency agent is in contact with the first surface and the heat-sealable composition is in contact with the second surface. 
     
     
         4 . The paper product of  claim 1 , wherein the cellulose fibers have a Schopper-Riegler freeness value in the range of from about 60° SR to about 95° SR. 
     
     
         5 . The paper product of  claim 1 , wherein the cellulose fibers have a Schopper-Riegler freeness value in the range of about 70° SR to about 90° SR. 
     
     
         6 . The paper product of  claim 1 , wherein the paper product has an opacity of less than or equal to about 32%. 
     
     
         7 . The paper product of  claim 1 , wherein the fibrous web has a basis weight of less than or equal to about 38 g/m 2 . 
     
     
         8 . The paper product of  claim 7 , wherein the basis weight is less than about 24 g/m 2  and greater than or equal to about 10 g/m 2 . 
     
     
         9 . The paper product of  claim 1 , wherein the bio-based wax or oil is a plant-based wax or oil, which has a melting point of from about 25° C. to about 75° C. 
     
     
         10 . The paper product of  claim 1 , wherein the bio-based wax or oil is a coconut-based wax, a palm-based wax, a soy-based wax, a rice-based wax, or mixtures thereof. 
     
     
         11 . The paper product of  claim 1 , wherein the polymer contained in the heat sealable composition comprises a thermoplastic starch. 
     
     
         12 . The paper product of  claim 1 , wherein the bio-based wax or oil is a plant derived wax or oil, which has a melting point of from about 25° C. to about 75° C. 
     
     
         13 . The paper product of  claim 1 , wherein polymer contained in the heat sealable composition comprises a protein, such as a whey protein, a soy protein, casein, or mixtures thereof. 
     
     
         14 . The paper product of  claim 2 , wherein a basis weight of the coating containing the heat-sealable composition is from about 1 g/m 2  to about 35 g/m 2 . 
     
     
         15 . The paper product of  claim 1 , wherein the wherein the paper product is substantially devoid of paraffins, polyolefin polymers, mineral oil, or hydrocarbon oils. 
     
     
         16 . The paper product of  claim 1 , wherein the fibrous web comprises wood pulp fibers, bast fibers or a combination thereof. 
     
     
         17 . The paper product of  claim 1 , wherein the paper product has a thickness of less than about 80 μm. 
     
     
         18 . The paper product of  claim 1 , wherein the transparency agent is present in the paper product in an amount greater than or equal to about 2% by weight and less than or equal to about 25% by weight.