Toray Industries, Inc.

Yuta Nakanishi

Masatoshi Ohkura

Yasuyuki Imanishi

Provided are a polypropylene film that has excellent structural stability relative to heat, is suitable for use in high-voltage capacitors or the like, and, when used in a high-voltage capacitor, has excellent long-term reliability in high-temperature environments; a metal layer laminated film that uses the polypropylene film; and a film capacitor. The polypropylene film has the sum of F5 values for the longitudinal direction and the width direction at 130° C. of at least 15 MPa and, for dielectric breakdown testing at 130° C., a dielectric breakdown voltage (B150) (V/μm) after heat treating for 1 minute at 150° C. and a dielectric breakdown voltage (B0) (V/μm) without heat treating satisfy the following relationship.(150)/(0)≥0.80

Polypropylene film, metal layer laminated film using polypropylene film, and film capacitor

A polypropylene film in which: during a heating process in thermomechanical analysis (TMA), the relationship (Ts−Tf)≤40° C. is satisfied by the temperature (Ts) (° C.) at which the film contracts by 0.1% in the longitudinal direction and the temperature (Tf) (° C.) at which the longitudinal shrink stress reaches 0.01 MPa; and the skewness (Ssk), which is the degree of bias of the protrusion shape, of at least one surface of the film is greater than −30 and less than 5. Thus provided is a polypropylene film that has excellent reliability and withstand voltage characteristics in high temperature environments when used in high voltage capacitors, that has a structure with excellent stability against heat and is suitable for applications in capacitors or the like to be used at high temperatures and high voltages, and that has excellent processability and does not wrinkle during a conveyance process including a vapor deposition process.

Polypropylene film, metal layer laminated film using same, and film capacitor

A polypropylene film has an excellent long-term operating reliability in a high temperature environment when used in a high-voltage capacitor, which is suitable for use in such capacitor applications and the like, and which has an excellent structural stability to heat; and a metal film-laminated film and a film capacitor including the same. The polypropylene film, wherein the relationship between the sum (E'135 (MD+TD)) of the storage moduli in the machine direction and the transverse direction of the film, as determined by solid viscoelasticity measurement at 135&#xb0; C., and the sum (E&#x2032;125(MD+TD)) of the storage moduli, as determined by solid viscoelasticity measurement at 125&#xb0; C., satisfies formula (1):&#x2032;135()/&#x2032;125()&#x3e;0.7&#x2003;&#x2003;(1).

Polypropylene film, metal film laminated film using same, and film capacitor

A polypropylene film exhibits a high breakdown voltage even in a high temperature environment and can exhibit a voltage resistance and reliability even in a high temperature environment when used as a capacitor, and a metal layer laminated film and a film capacitor using the polypropylene film. For the polypropylene film, at least one surface of the film has an elastic modulus of 2.6 GPa or more, measured by nanoindentation measurement, and the sum of heat shrinkage rates is in the film longitudinal and width directions 5% or less in a heat treatment at 130&#xb0; C. for ten minutes.

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Otsu, Japan

Yuta Nakanishi