| 摘要 |
A biaxially-oriented polypropylene film for an ultra-thin capacitor that has superior heat resistance, withstand voltage performance and long-term durability. The film has a stereoregularity in which mesopentad fraction (mmmm) as determined by measurement of high temperature nuclear magnetic resonance (high temperature NMR) is between 94% and 98%, a weight average molecular weight (Mw) of 250,000 to 450,000, a molecular weight distribution (Mw/Mn) of 4 to 7, and on a molecular weight distribution curve, a difference determined by subtracting the differential distribution value when the logarithm of molecular weight Log(M)=6 from the differential distribution value when Log(M)=4.5 that is 9% to 15%. The film is fabricated using a polypropylene raw material resin in which the composition of the aforementioned molecular weight distribution has been adjusted by peroxidative decomposition treatment of a polypropylene resin. |
