Polypropylene film, metal layer-integrated polypropylene film, film capacitor and film roll
A polypropylene film which is capable of suppressing blocking in a rolled polypropylene film. The polypropylene film has a first surface and a second surface, contains a polypropylene resin as a main component, and is configured such that: the Svk value (SvkA) of the first surface is 0.005 μm or more and 0.030 μm or less; the Spk value (SpkA) of the first surface is more than 0.035 μm and 0.080 μm or less; the Svk value (SvkB) of the second surface is 0.005 μm or more and 0.030 μm or less; and the Spk value (SpkB) of the second surface is 0.015 μm or more and 0.035 μm or less.
1. A polypropylene film having a first surface and a second surface, wherein
the polypropylene film contains a polypropylene resin as a main component;
a ratio Spk B /Spk A of a Spk value (Spk B ) of the second surface to a Spk value (Spk A ) of the first surface is 0.490 or more and 0.730 or less, and
a ratio Svk B /Svk A of a Svk value (Svk B ) of the second surface to a Svk value (Svk A ) of the first surface is 0.735 or more and 1.250 or less.
2. The polypropylene film according to claim 1 , which is biaxially stretched.
3. The polypropylene film according to claim 1 , wherein a ratio Sq B /Sq A of a Sq value (Sq B ) of the second surface to a Sq value (Sq A ) of the first surface is 0.4 to 1.0.
4. The polypropylene film according to claim 1 , wherein a ratio Sa B /Sa A of a Sa value (Sa B ) of the second surface to a Sa value (Sa A ) of the first surface is 0.6 to 1.0.
5. The polypropylene film according to claim 1 , wherein the polypropylene resin contains:
a linear polypropylene resin A having a difference of 8.0% or more attained by subtracting a differential distribution value when a logarithmic molecular weight Log (M)=6.0 from a differential distribution value when a logarithmic molecular weight Log (M)=4.5 in a molecular weight differential distribution curve;
a linear polypropylene resin B having a difference of less than 8.0% attained by subtracting a differential distribution value when a logarithmic molecular weight Log (M)=6.0 from a differential distribution value when a logarithmic molecular weight Log (M)=4.5 in a molecular weight differential distribution curve; and
a long-chain branched polypropylene resin C polymerized using a metallocene catalyst.
6. A metal layer-integrated polypropylene film comprising:
the polypropylene film according to claim 1 ; and
a metal layer stacked on either surface or both surfaces of the polypropylene film.
7. A film capacitor comprising the metal layer-integrated polypropylene film according to claim 6 that is wound or a configuration in which a plurality of the metal layer-integrated polypropylene films are stacked.
8. A film roll, wherein the polypropylene film according to claim 1 is wound into a roll.