Processing conventional papers and pulps into hydrophobic and water-resistant packaging materials and tableware

Abstract

A method of imparting hydrophobic properties to a paper product that comprises providing a paper product; immersing said paper product into a metal ion solution; and drying the paper product.

We claim: 
     
         1 . A method of imparting hydrophobic properties to a paper product, comprising:
 providing a paper product;   immersing or spraying said paper product into a metal ion solution; and   drying the paper product to produce an hydrophobic paper product.   
     
     
         2 . The method of  claim 1 , further comprising a deionized water rinsing step after the immersing or spraying step. 
     
     
         3 . The method of  claim 1 , wherein the metal ion solution has a pH of about 1 to about 5. 
     
     
         4 . The method of  claim 1 , wherein the hydrophobic paper product has increased water resistance, hydrophobicity and oleophilicity. 
     
     
         5 . The method of  claim 4 , wherein the hydrophobic paper product has a water contact angle above 100°. 
     
     
         6 . The method of  claim 5 , wherein the water contact angle is 100-150°. 
     
     
         7 . The method of  claim 4 , wherein the hydrophobic paper absorbs solvents and/or oils up to 10-50 times the paper's weight. 
     
     
         8 . The method of  claim 4 , wherein the water absorbance of the hydrophobic paper is less than 10 g/m 2 . 
     
     
         9 . The method of  claim 1 , wherein the paper product is a cellulose-based paper. 
     
     
         10 . The method of  claim 9 , wherein the paper product is a lignocellulosic fiber-based paper. 
     
     
         11 . The method of  claim 1 , wherein the paper product is chosen from A4, writing paper, Kraft packaging paper, newspaper, cardboard, or Kraft tissue paper. 
     
     
         12 . The method of  claim 1 , wherein the metal ion solution comprises at least one of Zr 4+ , Fe 3+ , Fe 2+ , Al 3+ , Y 3+ , Cu 2+ , Zn 2+ , and Co 2+ . 
     
     
         13 . The method of  claim 1 , wherein the metal ion solution comprises at least one of Zr 4+ , Fe 3+ , and Y 3+ . 
     
     
         14 . The method of  claim 1 , wherein the metal ion concentration is from about 0.1 mM to about 3 nM. 
     
     
         15 . The method of  claim 1 , wherein the metal ion concentration is from about 3 mM to about 80 nM. 
     
     
         16 . The method of  claim 1 , wherein the metal ion concentration is from about 1 mM to about 1M. 
     
     
         17 . The method of  claim 1 , wherein the immersion time is between 30 seconds to about 12 hours. 
     
     
         18 . The method of  claim 1 , wherein the immersion time is between 1 minute to about 4 hours. 
     
     
         19 . The method of  claim 1 , wherein the drying temperature of from 20-120° C. and a drying time of from 2 hours to 24 hours. 
     
     
         20 . The method of  claim 1 , wherein the metal ion solution comprises ZrOCl 2  or FeCl 3 .