Unlock instant, AI-driven research and patent intelligence for your innovation.

Polyolefin microporous membrane

A technology of microporous membrane and polyolefin, which is applied in structural parts, battery pack parts, electrochemical generators, etc., to reduce the film thickness, increase the number of windings and stacks, and reduce the puncture strength.

Pending Publication Date: 2022-05-27
ASAHI KASEI KK
View PDF18 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, Patent Document 5 presents a film design in which the strength is suppressed in order to suppress the thermal shrinkage rate, and there is still room for improvement regarding the safety of the battery.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Polyolefin microporous membrane
  • Polyolefin microporous membrane
  • Polyolefin microporous membrane

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0264] (A) 45 mass % of high-density polyethylene (PE5) with Mv of 700,000 and polydispersity (Mw / Mn) of 7.9, Mv of 250,000 and polydispersity (Mw / Mn) of 45% by mass using a rotary drum blender ) was 7.2 high-density polyethylene (PE2) 45 mass %, Mv was 400,000, and polydispersity (Mw / Mn) was 4.5 The homopolypropylene (PP1) 10 mass % was dry-blended to obtain a raw resin mixture. 32 mass % of raw material resin mixture, 68 mass % of liquid paraffin, and 0.1 mass % of antioxidant were blended to obtain a polyolefin composition. Next, the polyolefin composition was put into a twin-screw extruder, melted at a distance between casting rolls of 900 μm, and the polyolefin composition thus obtained was extruded to form a gel-like sheet, which was cooled with casting rolls cured.

[0265] (B) Using a simultaneous biaxial stretching machine, under the conditions of a set temperature of 119° C. and an area magnification of 64 times (the stretch magnification in the longitudinal directi...

Embodiment 2～21 and comparative example 1～21

[0271] A polyolefin microporous membrane was obtained by the same method as Example 1 except that the production conditions shown in Table 1 and Table 2 were used, and the evaluation was performed. The evaluation results are shown in Tables 1 and 2 below. However, in Comparative Example 18, the relaxation operation was not performed in the step (D). In Comparative Example 3 and Comparative Example 13, MD microstretching was not performed in the step (E).

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
thicknessaaaaaaaaaa
strengthaaaaaaaaaa
strengthaaaaaaaaaa
Login to View More

Abstract

Provided is a polyolefin microporous film having a film thickness of 1.0-17.0 [mu] m (inclusive), a bending coefficient of 0.3-1.5 ([mu] gf * cm2 / cm) / [mu] m3 (inclusive) in terms of weight per unit area, the bending coefficient being a value obtained by dividing the bending stiffness (gf * cm2 / cm) in the longitudinal direction (MD) by the cube of the film thickness ([mu] m), and a puncture strength of 70-160 gf / (g / m < 2 >) in terms of weight per unit area.

Description

technical field [0001] The present invention relates to polyolefin microporous membranes. Background technique [0002] Polyolefin microporous membranes exhibit excellent electrical insulating properties and ion permeability, and therefore, are used in battery separators, capacitor separators, fuel cell materials, fine filtration membranes, etc., especially as lithium ion secondary Separator for batteries. [0003] In recent years, lithium ion secondary batteries have also been used in small electronic devices such as cellular phones and notebook personal computers, and in electric vehicles such as electric vehicles and small electric bicycles. Separators for lithium ion secondary batteries are not only required to have mechanical properties and ion permeability, but also high safety against impact tests, and moderately low rigidity is required in the manufacturing process of prismatic batteries. In addition, recently, with regard to its production method, it has been stud...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): C08L23/06C08L23/12C08J5/22H01M50/417H01M10/0525
CPCC08J5/2275H01M50/417H01M10/0525C08J2323/06C08J2423/06C08J2423/12C08L23/0815C08J5/18C08J2323/08B29C48/0018B29C55/16B29C61/06B29C48/08B29C48/92Y02E60/10C08L23/12C08J9/26C08F210/16C08F210/06C08L23/06C08L2203/20C08L2205/02C08L2207/062
Inventor 川知真奈宫泽博关口学久光伸弥小田佳辉
Owner ASAHI KASEI KK