▎ 摘　　要

NOVELTY - Modified masterbatch comprises 1-10 pts. wt. graphene, 90-99 pts. wt. polyethylene, 0.1-0.5 pts. wt. coupling agent, and 0.2-1 pts. wt. antioxidant. USE - Modified masterbatch used for preparing polyethylene protective film (claimed). ADVANTAGE - The modified master batch has improved the thermal conductivity protection film, and solves the problem that the polyethylene protection film thermal conductivity. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) a method for preparing modified master batch, which involves (a) weighing each raw material component according to the prescription amount, and (b) uniformly mixing the graphene nano sheet, polyethylene, coupling agent, antioxidant, putting in a double-screw extruder, melting and mixing uniformly, extruding, cooling to room temperature, granulating, drying to obtain the product, preferably, each section temperature of the screw rod of the double-screw extruder is 170-185 ℃; (2) a polyethylene protective film, which comprises a base film outer layer, a base film middle layer, a base film inner layer and a coating layer; and (3) a method for preparing polyethylene protective film, which involves mixing the raw material components of the inner layer of the base film, the middle layer of the base film and the outer layer of the base film, and placing them in an extruder in the method, plasticizing extrusion, blow molding, cooling, drawing and winding, promptly obtain the inner layer of the base film, the middle layer of the base film and the outer layer of the base film, and then coat the coating layer on the inner layer of the base film to obtain the product.