Borealis Ag

Franciscus Jacobs

Dietrich Gloger

Hermann Braun

Davide Tranchida

Johannes Wolfschwenger

Antonios Gitsas

Wolfram Stadlbauer

Guido Boelaers

Thomas Horill

Gregory Potter

Antonis Gitsas

Matthew Parkinson

Paul Allemeersch

Werner Verwimp

Marc Verheijen

Lodewijk Hendrickx

Erwin Vanzeir

Helmut Rinnerthaler

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.

Biaxially oriented polypropylene film with improved breakdown strength

The present invention refers to a structure comprising a biaxially oriented polypropylene (BOPP) film having at least one layer comprising a homopolymer of propylene which layer is in contact with an oil phase, the homopolymer of propylene has a) a content of isotactic pentads in the range from 95% to 98%, and b) a content of ash of not more than 30 ppm, based on the total weight of the homopolymer of propylene, characterized in that the oil phase has an absorbance value of &#x2264;0.1, relative to the pure oil, as determined spectrophotometrically at a wavelength of 860 nm by the reduction of transmitted light intensity. The present invention further refers to the use of a biaxially oriented polypropylene (BOPP) film for making capacitors comprising said structure, wherein the oil phase has an absorbance value of &#x2264;0.1, relative to the pure oil, as determined spectrophotometrically at a wavelength of 860 nm by the reduction of transmitted light intensity as well as the use of the homopolymer of propylene for increasing the life time of a capacitor.

Polypropylene film structure having increased life time

The present invention is biaxially oriented film comprising a layer comprising a propylene polymer composition comprising a high isotactic homopolymer of propylene and a polymeric &#x3b1;-nucleating agent. The composition may also comprise other propylene polymers.

Biaxially oriented films made of propylene polymer compositions

The present invention is a structure comprising a biaxially oriented film having a layer comprising a homopolymer of propylene which layer is in contact with oil, characterised in that the homopolymer of propylene has a content of isotactic pentads of from 95% to 98% and a content of ash of not more than 30 ppm.

Polypropylene film structure

The present invention relates to a new biaxially oriented polypropylene (BOPP) film, a process for the preparation of such film as well as the use of a polypropylene for the preparation of such film and an article comprising such film.

BOPP film with improved stiffness/toughness balance

Growing community of inventors

Evergem, Belgium

Franciscus Jacobs