Prime Polymer Co., Ltd.

Mitsui Chemicals, Inc.

Katsutoshi Ohta

Satoshi Tamura

Yoshio Yanagishita

Chikara Satou

Provided are a propylene homopolymer composition for a capacitor film, from which a thin film can be easily produced and which can provide a film with excellent high-temperature voltage resistance, a method for producing the same, and a capacitor film. The propylene homopolymer composition for a capacitor film contains 1% by mass or more and less than 50% by mass of a propylene homopolymer (A1) having predetermined characteristics and more than 50% by mass and 99% by mass or less of a propylene homopolymer (B1) having predetermined characteristics, and has (i) a melt flow rate (MFR) of 1.0 to 10.0 g/10 min and (ii) a chlorine content of 2 ppm by mass or less.

Propylene homopolymer composition for capacitor film, method for producing the same, and capacitor film

Provided are a propylene homopolymer composition for a capacitor film, which can provide a film with excellent high-temperature voltage resistance and excellent thin-film stretchability, a method for producing the same, and a capacitor film. The propylene homopolymer composition for a capacitor film contains 50 to 99% by mass of a propylene homopolymer (A1) having predetermined characteristics and 1 to 50% by mass of a propylene homopolymer (B1) having predetermined characteristics, and has (i) a melt flow rate (MFR) of 1.0 to 10.0 g/10 min and (ii) a chlorine content of 2 ppm by mass or less.

[Problem] To provide polypropylene for a microporous film having excellent heat resistance and strength. [Solution] Polypropylene for a microporous film satisfying the following requirements (1) and (2): (1) the weight-average molecular weight (Mw) value, as determined by gel permeation chromatography (GPC), is not less than 100,000 but less than 800,000, the value (Mw/Mn) obtained by dividing the weight-average molecular weight by the number-average molecular weight is more than 7.0 but not more than 12.0, and the value (Mz/Mw) obtained by dividing the Z-average molecular weight by the weight-average molecular weight is not less than 3.8 but not more than 9.0, and (2) the mesopentad fraction, as measured byC-NMR (nuclear magnetic resonance method), is not less than 95.5%.

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Ichihara, Japan

Katsutoshi Ohta