Temperature-resistant insulating mica powder / polypropylene composite film and preparation method thereof

By introducing olefin polymerization catalytic active centers and ultra-high molecular weight polypropylene onto the surface of mica powder, a copolymer shell and viscosity gradient are formed, which solves the insulation and thermal stability problems of polypropylene films under electrothermal fields and improves the insulation and thermal stability of composite films.

CN121801200APending Publication Date: 2026-04-07ANHUI SHISONG NEW MATERIAL TECH CO LTD
1 Cites 0 Cited by

Patent Information

Application Number
CN202610067468.5
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2026-01-19
Publication Date
2026-04-07

AI Technical Summary

Technical Problem

Existing polypropylene films are prone to molecular chain breakage under the combined action of electro-thermal fields, leading to insulation failure. Furthermore, inorganic particle doping can easily form agglomerates, reducing breakdown field strength and thermal stability.

Method used

By introducing olefin polymerization catalytic active centers on the surface of mica powder particles to form a propylene/α-olefin copolymer shell, and introducing ultra-high molecular weight polypropylene with molecular weights of 500,000-1.5 million and 2,000,000-4.5 million, a viscosity gradient is constructed to improve interfacial compatibility and molecular entanglement density.

Benefits of technology

It significantly improves the insulation and thermal stability of the composite film, with a transverse and longitudinal thermal shrinkage rate of 0.98-1.51% and a breakdown strength of 573.28-589.31kV/mm, making it suitable for capacitors, power batteries and high-voltage DC transmission systems.

✦ Generated by Eureka AI based on patent content.
Patent Text Reader

Abstract

The invention discloses a temperature-resistant insulating mica powder / polypropylene composite film and a preparation method thereof, and belongs to the field of polymer film processing. The preparation method of the composite film comprises the following steps: (1) loading an olefin polymerization catalyst on the surfaces of mica powder particles, and carrying out in-situ polymerization on the prepared particles loaded with the olefin polymerization catalyst in a mixed component of alpha-olefin and propylene to prepare polypropylene / mica powder composite particles; and (2) blending polypropylene resin, the polypropylene / mica powder composite particles, a viscosity modifier and an auxiliary agent, granulating, and calendaring to obtain the polypropylene composite material. A firm polypropylene shell layer is formed on the surface of the mica powder, so that the interfacial compatibility of the mica powder and polypropylene is enhanced, good dispersion is realized, and the insulativity of the polypropylene is remarkably improved; meanwhile, the melt viscosity of polypropylene matched with the viscosity modifier is constructed, the molecular entanglement density of a composite system is remarkably improved, the movement of a polypropylene molecular chain is effectively limited, and the thermal stability of the composite film is improved.
Need to check novelty before this filing date? Find Prior Art