Matt composite film with high heat sealability

Abstract

The invention belongs to the technical field of shell packaging, and particularly relates to a matte composite film with high heat sealability. The matte composite film comprises a plain foil layer, a protective layer is arranged on the matte surface of the plain foil layer, the protective layer is made of a metal surface treating agent, a film is arranged on the protective layer, and the film and the protective layer are connected through a modified polyurethane adhesive; a special protective layer is arranged on the bright surface of the plain foil layer, an improved surface film-forming agent is adopted in the special protective layer, a multifunctional inner layer is arranged on the protective layer, and the overall thickness of the aluminum-plastic film is 111-155 [mu]m. By manufacturing the special protective layer, corrosion of a low-molecular-weight strong solvent in the electrolyte can be blocked, and the composite strength of the inner layer is improved. And due to the use of the swelling-resistant modified polypropylene or polyethylene, the heat-sealed bonding structure does not have great structural change in a strong solvent soaking environment of electrolyte, so that the heat sealing performance and the chemical resistance of the heat-sealed bonding structure are improved.

Description

technical field [0001] The invention belongs to the technical field of packaging, in particular to a matte composite film with strong heat sealing performance. Background technique [0002] With the development of the new energy industry, especially the market demand for large-capacity energy storage and high-power discharge is gradually increasing. Become one of the mainstream needs of the market. At present, the main material for the packaging of soft-pack lithium power batteries is aluminum-plastic composite film, but the matte composite film with strong aluminum heat sealing performance at this stage has insufficient stamping and forming performance. After the battery is made, the heat sealing performance drops significantly, and the surface The layer generates heat during the long-term charging and discharging of the matte composite film, which causes long-term stress concentration at the interface of the composite layer, which may cause the surface layer to fall off, ...

AI Technical Summary

Problems solved by technology

At present, the main material for the packaging of soft-pack lithium power batteries is aluminum-plastic composite film, but the matte composite film with strong aluminum heat sealing performance at this stage has insufficient stamping and forming performance. After the battery is made, the heat sealing performance drops significantly, and the surface The layer generates heat during long-term charging and discharging of the matte composite film, which causes long-term stress concentration at the interface of the composite layer, which may cause the surface layer to fall off, and there is a certain safety risk.