Patent ID: 8475629

Claim:
A process for making a repulpable, grease and water resistant paper selected from the group consisting of Kraft, linerboard, medium and combinations thereof, having improved wet strength, the process comprising: depositing a furnish on a wire and dewatering the furnish to form a paper selected from the group consisting of Kraft, linerboard, medium and combinations thereof, subsequently pressing the dewatered paper a number of times to further reduce the water content of the paper, adding to the pressed paper selected from the group consisting of Kraft, linerboard, medium and combinations thereof, a mixture comprising an effective amount of a methyl methacrylate containing composition, the composition consisting of at least one member selected from the group consisting of alkyl ketene dimer, alkenyl ketene dimer, alkyl succinic anhydride and alkenyl succinic anhydride, a blend of methyl methacrylate with a synthetic polyethylene, a crosslinking agent for the methyl methacrylate, and a solvent, to at least one side of the dewatered paper subsequent to a first pressing step, wherein the methyl methacrylate containing composition is applied in an amount between approximately 0.5-2.2 dry lbs methyl methacrylate containing composition per 1000 ft 2 of paper yielding an edge crush (as measured by TAPPI Test Method T 811) of at least 74.9% retention.