▎ 摘　　要

NOVELTY - An inflatable composite film comprises outer PET film, middle adhesive layer and inner polyethylene film. The inner polyethylene film is polyethylene film toughened by core-shell particle. The mass ratio of polyethylene and core-shell particle is 1-1.5:1. The core-shell particles are particles composed of carbon nanomaterial coated with nano calcium carbonate. The nano calcium carbonate is nanoparticles processed by modified surface agent. USE - The inflatable composite film is used for packaging bag (claimed). ADVANTAGE - The method can reduce manufacturing cost of whole packaging bag by 20-30% by toughening and modifying inner layer polyethylene layer, improves mechanical property, impact resistance and toughness of polyethylene, and increases film wear resistance. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing composite film comprising: dissolving nano calcium carbonate in mixed solution of water and ethanol, using magnetic stirrer to stir to completely wet calcium carbonate, dissolving surface modifier in ethanol under the action of ultrasonic waves, and gradually adding solution to calcium carbonate suspension; reacting at 80-100degrees Celsius for 1-2hours, taking out solution after reaction, drying and storing, mixing and dispersing nano material and modified nano calcium carbonate in absolute ethanol, adding modified surface agent, stirring for 2-4 hours under the action of ultrasonic waves, standing for 2-4 hours, and quickly evaporating at 100-120degrees Celsius; and weighing polyethylene and core-shell structure particles according to mass ratio of 1-1.5:1, setting blending temperature at 180-260degrees Celsius, putting polyethylene into mixing device for mixing after reaching set temperature, adding core-shell particles for blending, adding blended material into extruder to extrude and form, coating adhesive on polyethylene film, and compounding polyethylene film and PET film.