BIAXIALLY ORIENTED POLYPROPYLENE FILM WITH IMPROVED BREAKDOWN STRENGTH

    公开(公告)号:US20220033631A1

    公开(公告)日:2022-02-03

    申请号:US17413612

    申请日:2019-12-20

    Applicant: BOREALIS AG

    Abstract: The present invention is directed to a biaxially oriented polypropylene (BOPP) film with improved breakdown strength and to a capacitor comprising an insulation film comprising a layer of the biaxially oriented polypropylene film of the present invention. The present invention is further directed to a process for producing a biaxially oriented polypropylene film. Finally, the present invention is further directed to the use of a biaxially oriented polypropylene film of the present invention as layer of an insulation film of a capacitor. The BOPP film comprises a polypropylene composition, wherein the polypropylene composition comprises a high isotactic homopolymer of propylene and a polymeric α-nucleating agent. The BOPP film has a dielectric breakdown field strength Eb63.2 of at least 595 kV/mm. The process for producing a biaxially oriented polypropylene film comprises the steps of extruding a polypropylene composition to a flat film and orienting the flat film simultaneously in the machine direction and in the transverse direction.

    NUCLEATED PROPYLENE POLYMER COMPOSITION WITH HIGH TOUGHNESS

    公开(公告)号:US20220135714A1

    公开(公告)日:2022-05-05

    申请号:US17429230

    申请日:2020-01-20

    Applicant: BOREALIS AG

    Abstract: The present invention is directed to a propylene polymer composition comprising (a) at least 90 wt. %, based on the weight of the total propylene homopolymer composition, of a propylene homopolymer having (i) a pentad isotacticity (mmmm) of equal or more than 98.0 mol.-%, determined by quantitative 13C NMR spectroscopy, (ii) a relative amount of erythro regio-defects of not more than 0.2 mol.-%, determined by quantitative 13C NMR spectroscopy, as described herein, and (b) a nucleating agent (B) selective for the beta-modification of isotactic polypropylene in an amount of from 0.001 to 1.0 wt. %, based on the weight of the total propylene homopolymer composition, wherein said propylene homopolymer composition has a melt flow rate MFR2 (230° C., 2.16 kg) according to ISO 1133 of 0.1 to 10 g/10 min., a beta-phase content of not less than 80%, measured by wide angle x-ray scattering (WAXS). Further disclosed is a moulded propylene homopolymer product obtainable by compression moulding or extrusion of the propylene homopolymer composition.

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