Abstract Porous cellulosic stock can be coated with a thermoplastic polymer coating while being impregnated with a wax by this invention. A dispersion of polymer particles in molten wax is applied to cellulosic stock at a temperature below the melting point of the polymer. This treated cellulosic stock is then heated to a temperature above the melting point of the polymer and subjected to pressure. The resulting laminated product is polymer coated-wax impregnated cellulosic stock. The polymer used must be substantially insoluble in the molten wax at a temperature below the melting point of the polymer and must be fusible below a temperature which would degrade the stock. This product has utility as a packaging material comprising a high water vapor barrier coupled with a tough, scuff-resistant, nonblocking surface.
Method according to claim 1 wherein said heterogeneous composite contains 5 to 65 parts by weight of finely divided polymer and 35 to 95 parts by weight of said wax.
Claim 2
Dependent Claim
16 words
Method according to claim 1 wherein all the finely divided polymer is finer than 100 mesh.
Claim 3
Dependent Claim
16 words
Method according to claim 1 wherein all the finely divided polymer is finer than 200 mesh.
Claim 4
Dependent Claim
12 words
Method according to claim 1 wherein the wax is a petroleum wax.
Claim 5
Dependent Claim
26 words
Method according to claim 5 wherein heterogeneous composite contains 5 to 65 parts by weight of finely divided polymer, said polymer being finer than 100 mesh.
Claim 6
Dependent Claim
34 words
Method according to claim 1 wherein the heterogeneous composite contains 5 to 65 parts by weight of finely divided polymer, said polymer being finer than 100 mesh, and the wax is a petroleum wax.
Claim 7
Dependent Claim
42 words
Method according to claim 7 wherein the thermoplastic polymer is selected from the group consisting of: polyethylene with a molecular weight in excess of 1,000,000, polypropylene with a molecular weight in excess of 100,000, polyamide, cellulosic, polystyrene, polycarbonate, rigid polyvinylchloride and acrylic.
Claim 8
Dependent Claim
29 words
Method according to claim 8 wherein said heterogeneous composite contains 10 to 55 parts by weight of finely divided polymer and 35 to 90 parts by weight of wax.