Cast polypropylene film for aluminum-plastic composite film and preparation method of cast polypropylene film

Abstract

The invention relates to a cast polypropylene film for an aluminum-plastic composite film and a preparation method of the cast polypropylene film. The three-layer co-extruded cast polypropylene film is obtained by adopting a three-layer co-extrusion method for casting through three extruder heads of a melt extruder, and in turn comprises a plasma treatment layer, a core layer and a heat seal layer, wherein the plasma treatment layer is mainly made of random copolymer polypropylene, maleic anhydride modified polypropylene and an polyolefin elastomer, the core layer is mainly made of homopolypropylene, organically modified nano silica and an polyolefin elastomer, and the heat seal layer is mainly made of random or block copolymer polypropylene, a polyolefin elastomer and a slip agent. Due tothe high thermal conductivity and flexibility of a CPP film, the aluminum-plastic composite film formed by compounding through a thermal process is better resistant to deep drawing molding, easier for heat sealing, and more resistant to electrolytes, and the service life and use of the composite aluminum-plastic film are enhanced.

Description

Technical field [0001] The invention relates to the technical field of aluminum-plastic composite film production, in particular to a cast polypropylene film for aluminum-plastic composite film and a preparation method thereof. Background technique [0002] Lithium battery flexible packaging has now become a more and more widely used packaging method. Its main structure is composed of three-layer film materials. From the outside to the inside, there are a protective layer, an aluminum foil layer and a heat seal layer. The protective layer is usually Biaxially stretched nylon film, the heat seal layer is cast polypropylene (CPP). The electrolyte of a lithium battery contains a variety of organic solvents and lithium salts, and the lithium salt will quickly produce highly corrosive hydrofluoric acid when exposed to water. Once it corrodes the CPP or even destroys the inner bonding layer of the aluminum-plastic composite film, and damage The surface of the aluminum foil will make t...

AI Technical Summary

Problems solved by technology

For example, during deep forming, the CPP film with poor toughness and strength is prone to stress whitening and even breaks through; high temperature treatment will change the smoothing agent on the surface of the CPP film, and the gap between the CPP surface of the heat seal layer and the deep drawing mold The coefficient of friction is not easy to control, which also affects the drawing and forming of the aluminum-plastic composite film. During heat sealing, the heat sealing effect between the CPP films will also be poor, which affects the electrolyte resistance of the aluminum-plastic composite film.

Images