Patent ID: 9349538
Filing Date: 2016-05-24
CPC Classification: C08J,C08L,H01G,Y10T

Claim Text:
1. A biaxially-oriented polypropylene film for a capacitor, wherein, together with having stereoregularity in which mesopentad fraction (mmmm) as determined by measurement of high temperature nuclear magnetic resonance (high temperature NMR) is 94% or more to less than 98%, weight average molecular weight (Mw) as measured by gel permeation chromatography (GPC) is 250,000 to 450,000, molecular weight distribution (Mw/Mn) is 4 to 7, and on a molecular weight distribution curve, the difference determined by subtracting the differential distribution value when the logarithm of molecular weight Log(M)=6 from the differential distribution value when the logarithm of molecular weight Log(M)=4.5 is 9% to 15%; and, uses a polypropylene raw material resin in which the composition of the molecular weight distribution has been adjusted by peroxidative decomposition treatment of a polypropylene resin, wherein the biaxially-oriented polypropylene film contains at least one type of hindered phenol-based antioxidant having a carbonyl group, and the residual content thereof in the film is 4000 ppm (by weight) to 6000 ppm (by weight).