Methods for manufacturing recyclable and repulpable packaging materials

Abstract

Polymeric formulations which contain aqueous dispersions of acrylic monomers and copolymers and modified polyethylene terephthalate resin are disclosed which are useful as a coating system or treatment for imparting water, oil and grease resistance to underlying cellulosic substrates. The formulations do not contain any fluorochemicals, polyethylene or wax. Moreover, the formulations provide water, oil and grease resistance properties that are an improvement in the art to known coatings and treatments which contain polyethylene and or wax for water, oil and grease resistance. These coatings can also impart improved anti-wicking properties over the existing art. These formulations have interest as they contain components that are permitted to come into direct contact with food products. Therefore, the formulations of the present invention are ideal for use as coatings for paper and paperboard, including paper packaging such as that utilized in food wrappers, food containers, food receptacles, etc. In addition, because these formulations do not contain fluorochemicals, polyethylene or wax the resulting paper products can be recycled and repulped.

1 . A water, oil and grease resistant material comprising a cellulosic substrate having applied to at least one surface thereof an aqueous dispersion of an acrylic monomer or copolymer and modified polyethylene terephthalate resin, wherein said dispersion comprises 20 to 65 percent by weight acrylic monomer or copolymer, and from about 35 to 80 percent by weight modified polyethylene terephthalate of the dispersion. 
     
     
         2 . The material of  claim 1 , wherein the cellulosic substrate is flexible paper. 
     
     
         3 . The material of  claim 1 , the cellulosic substrate is paperboard. 
     
     
         4 . The material of  claim 1 , where the cellulosic substrate is corrugated paper. 
     
     
         5 . The material of  claim 1 , where the cellulosic substrate is corrugated box. 
     
     
         6 . The material of  claim 1 , where the paperboard can be folded. 
     
     
         7 . The material of  claim 1 , where the cellulosic substrate is resistant to water. 
     
     
         8 . The material of  claim 1 , where the cellulosic substrate is resistant to oil and grease. 
     
     
         9 . The material of  claim 1 , where the cellulosic substrate exhibits excellent anti-wicking properties. 
     
     
         10 . The material of  claim 1 , wherein the polyethylene terephthalate is at least partially cross-linked. 
     
     
         11 . The material of  claim 1 , where the cellulosic substrate is compliant with direct food contact regulations. 
     
     
         12 . The material of  claim 1 , wherein the polyethylene terephthalate resin is at least partially cured to permit subsequent repulping and recycling of the material. 
     
     
         13 . The material of  claim 1 , wherein the dispersion is applied to the at least one surface of the cellulosic substrate at 0.80 to 2.50 pounds per 1000 square feet. 
     
     
         14 . The material of  claim 1 , wherein the modified polyethylene terephthalate resin is prepared by modifying solid polyethylene terephthalate resin with ammonium hydroxide. 
     
     
         15 . The material of  claim 1 , wherein the acrylic monomer or copolymer is a styrene acrylic. 
     
     
         16 . A water, oil and grease resistant formulation for cellulosic substrates comprising an aqueous dispersion of an acrylic monomer or copolymer and a water-dispersible polyethylene terephthalate (PET) resin wherein said dispersion comprises 35 to 80% modified polyethylene terephthalate resin by weight and 20 to 65% acrylic monomer or copolymer by weight of the formulation. 
     
     
         17 . The material of  claim 16 , wherein the water-dispersible PET is prepared by modifying solid PET resin with ammonium hydroxide. 
     
     
         18 . The material of  claim 16 , wherein the acrylic monomer or copolymer is a styrene acrylic.