▎ 摘　　要

NOVELTY - A waterproof breathable film comprises a waterproof wear-resistant layer, a breathable layer, a substrate layer, and a ductile waterproof layer. The waterproof wear-resistant layer is a graphene modified polyurethane coating layer comprising polyurethane, graphene oxide, isophorone diisocyanate, hydrazine hydrate, and solvent N,N-dimethylformamide. The ductile waterproof layer is a graphene-poly(styrene-butadiene-styrene)-modified asphalt layer comprising asphalt matrix, poly(styrene-butadiene-styrene), graphene, and stabilizer. USE - Waterproof breathable film used in clothing. ADVANTAGE - The waterproof breathable film has excellent waterproof effect, and breathability, and provides comfort to user. DETAILED DESCRIPTION - A waterproof breathable film comprises a waterproof wear-resistant layer, a breathable layer, a substrate layer, and a ductile waterproof layer arranged in order from top to bottom portions. The waterproof wear-resistant layer is a graphene modified polyurethane coating layer comprising 40-60 pts. wt. polyurethane, 0.5-3 pts. wt. graphene oxide, 10-15 pts. wt. isophorone diisocyanate, 3-10 pts. wt. hydrazine hydrate, and certain amount of solvent N,N-dimethylformamide. The breathable layer is an ethylene-vinyl acetate elastic foam layer. The ductile waterproof layer is a graphene-poly(styrene-butadiene-styrene)-modified asphalt layer comprising 100-150 pts. wt. asphalt matrix, 10-20 pts. wt. poly(styrene-butadiene-styrene), 0.5-2 pts. wt. graphene, and 3-7 pts. wt. stabilizer. The substrate layer and air-permeable layer are connected with each other through an adhesive layer between substrate layer and ductile waterproof layer. An INDEPENDENT CLAIM is included for production of waterproof breathable film, which involves (i) weighing graphene oxide and 200-500 ml N,N-dimethylformamide, ultrasonically mixing, ultrasonically dispersing for 10-20 minutes, adding isophorone diisocyanate, reacting at 70-82 degrees C for 3-5 hours in a nitrogen protection atmosphere, adjusting the pH to 9-10, heating at 90-100 degrees C, reducing with hydrazine hydrate, washing the reaction product with N,N-dimethylformamide, drying to obtain functionalized graphene, uniformly mixing functionalized graphene and aqueous polyurethane, and ultrasonically processing for 20-30 minutes to obtain graphene-modified polyurethane coating, (ii) crushing poly(styrene-butadiene-styrene), mixing graphene and crushed poly(styrene-butadiene-styrene) to obtain graphene-poly(styrene-butadiene-styrene) composite modifier, adding composite modifier and asphalt matrix to a reactor, stirring at 160-180 degrees C for 30-60 minutes, transferring the mixture to a shear machine, cutting for 10-20 minutes, adding stabilizer to the mixture, stirring at 160-170 degrees C for 20-30 minutes, and cooling to obtain modified asphalt, (iii) stretching the substrate layer, coating the surface of substrate layer with an adhesive layer, adhering to the breathable layer, coating graphene modified polyurethane on the upper surface of the breathable layer, coating the lower surface of the substrate layer with an adhesive, and gluing the lower surface of graphene-poly(styrene-butadiene-styrene)-modified asphalt layer with adhesive.