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

Patent metadata

Field	Value
Publication number	US-10793708-B2
Application number	US-201515315639-A
Country	US
Kind code	B2
Filing date	Jul 30, 2015
Priority date	Jul 31, 2014
Publication date	Oct 6, 2020
Grant date	Oct 6, 2020

Abstract

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.

First claim

The invention claimed is:

1. A propylene homopolymer composition for a capacitor film, comprising 50 to 99% by mass of a propylene homopolymer (A1) having characteristics (A-i) to (A-iii) below and 1 to 50% by mass of a propylene homopolymer (B1) produced using a Ziegler-Natta catalyst and having characteristics (B-i) to (B-ii) below (with a sum of the propylene homopolymer (A1) and the propylene homopolymer (B1) being 100% by mass), and having:
(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,
wherein
(A-i) a mesopentad fraction (mmmm) measured by 13 C-NMR is 0.930 or more,
(A-ii) a half width of an elution peak measured by temperature rising elution fractionation (TREF) is less than 4.0° C.,
(A-iii) a molecular weight distribution Mw/Mn measured by GPC is less than 3.0,
(B-i) a mesopentad fraction (mmmm) measured by 13 C-NMR is 0.950 or more, and
(B-ii) a molecular weight distribution Mw/Mn measured by GPC is 3.8 or more.

2. The propylene homopolymer composition for a capacitor film according to claim 1 , wherein the propylene homopolymer (A1) is produced using a metallocene catalyst.

3. A capacitor film obtained by stretching the propylene homopolymer composition for a capacitor film according to claim 1 at an area stretch ratio (area ratio of length×width) of 30 to 80.

4. The propylene homopolymer composition for a capacitor film according to claim 1 , wherein a molecular weight distribution Mw/Mn is 3.8 or more and 12.0 or less in the characteristic (B-ii).

5. A propylene homopolymer composition for a capacitor film, comprising 50 to 99% by mass of a propylene homopolymer (A1) having characteristics (A-i) to (A-iii) below and 1 to 50% by mass of a propylene homopolymer (B1) having characteristics (B-i) to (B-ii) below (with a sum of the propylene homopolymer (A1) and the propylene homopolymer (B1) being 100% by mass), and having:
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,
wherein
(A-i) a mesopentad fraction (mmmm) measured by 13 C-NMR is 0.930 or more,
(A-ii) a half width of an elution peak measured by temperature rising elution fractionation (TREF) is less than 4.0° C.,
(A-iii) a molecular weight distribution Mw/Mn measured by GPC is less than 3.0,
(B-i) a mesopentad fraction (mmmm) measured by 13 C-NMR is 0.950 or more, and (B-ii) a molecular weight distribution Mw/Mn measured by GPC is 3.8 or more.

6. A capacitor film having a thickness of 1 to 50 μm, comprising the propylene homopolymer composition for a capacitor film according to claim 1 .

7. The capacitor film according to claim 6 , having a thickness of 1 to 4 μm.

8. The capacitor film according to claim 6 , which is a capacitor separator film.

Assignees

• Mitsui Chemicals Inc
• Prime Polymer Co Ltd

Inventors

• Ohta Katsutoshi

Classifications

• H01G4/18

  of synthetic material, e.g. derivatives of cellulose (H01G4/16 takes precedence) · CPC title

• C08F4/6592

  containing at least one cyclopentadienyl ring, condensed or not, e.g. an indenyl or a fluorenyl ring · CPC title

• Y02T10/70

  Energy storage systems for electromobility, e.g. batteries · CPC title

• C08L2314/02

  Ziegler natta catalyst · CPC title

• C08L2205/025

  containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure · CPC title