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High-temperature extrusion method for preparing polyolefin microporous films

A microporous diaphragm and extruder technology, which is applied in the field of preparation of polyolefin microporous films, can solve the problems of few crystal points and high puncture strength of microporous diaphragms, achieve excellent puncture strength, mature process technology, and reduce melt jitter. Effect

Inactive Publication Date: 2016-01-13
SHENZHEN SENIOR TECH MATERIAL
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The prepared microporous diaphragm has the characteristics of less crystal points and high puncture strength, and solves the phenomenon of melt jitter in the casting process

Method used

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  • High-temperature extrusion method for preparing polyolefin microporous films
  • High-temperature extrusion method for preparing polyolefin microporous films
  • High-temperature extrusion method for preparing polyolefin microporous films

Examples

Experimental program
Comparison scheme
Effect test

preparation Embodiment 1

[0038] Preparation Example 1 steps are as follows:

[0039] a. High-temperature casting: the polypropylene particles are passed through the extruder, plasticized at a higher temperature to form a polypropylene melt, and then extruded from the die, and cast into a 14.8μ sheet polypropylene base The film is obtained as a sheet-shaped polypropylene base film, which is harvested in a roll shape with a length of 1000 m.

[0040] b. Annealing treatment: put the rolled base film into an oven to improve the polypropylene sheet crystal structure.

[0041] c. Uniaxial stretching: After the annealed polyolefin base film is compounded, stretched in cold state, stretched in hot state, set at high temperature, and cooled, a 25μ microporous diaphragm can be obtained.

[0042] The polypropylene adopts isotactic polypropylene with isotacticity ≥ 90%, and the average molecular weight is 1×10 6 ~5×10 6 , The melt index is 2.1g / 10min.

[0043] In the step a, the working temperature of the ext...

preparation Embodiment 2

[0047] Preparation Example 2 steps are as follows:

[0048] a. High-temperature casting: the polypropylene particles are passed through the extruder, plasticized at a higher temperature to form a polypropylene melt, and then extruded from the die, and cast into a 19μ sheet polypropylene base film by a cooling roll , to obtain a sheet-like polypropylene base film, harvested in a roll, with a length of 1000m.

[0049]b. Annealing treatment: put the rolled base film into an oven to improve the polypropylene sheet crystal structure.

[0050] c. Uniaxial stretching: After the annealed polyolefin base film is compounded, stretched in cold state, stretched in hot state, set at high temperature, and cooled, a 16μ microporous diaphragm can be obtained.

[0051] The polypropylene adopts isotactic polypropylene with isotacticity ≥ 90%, and the average molecular weight is 1×10 6 ~5×10 6 , The melt index is 2.1g / 10min.

[0052] In the step a, the working temperature of the extruder is ...

preparation Embodiment 3

[0056] Preparation Example 3 steps are as follows:

[0057] a. High-temperature casting: the polypropylene particles are passed through the extruder, plasticized at a higher temperature to form a polypropylene melt, then extruded from the die, and cast into a 24μ sheet polypropylene base film by a cooling roll , to obtain a sheet-like polypropylene base film, harvested in a roll, with a length of 1000m.

[0058] b. Annealing treatment: put the rolled base film into an oven to improve the polypropylene sheet crystal structure.

[0059] c. Uniaxial stretching: After the annealed polyolefin base film is compounded, stretched in cold state, stretched in hot state, set at high temperature, and cooled, a 20μ microporous diaphragm can be obtained.

[0060] The polypropylene adopts isotactic polypropylene with isotacticity ≥ 90%, and the average molecular weight is 1×10 6 ~5×10 6 , The melt index is 2.1g / 10min.

[0061] In the step a, the working temperature of the extruder is 220...

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Abstract

A traditional extrusion casting preparation method has the problems that the number of fish eyes is large and melt shaking is prone to occurring, and the capacity improvement of separation films is restricted seriously. Currently, many domestic separation film manufacturers prepare preforms of microporous films through a low-temperature extrusion casting method which has the defects of being uneven in plasticization and poor in melt strength. According to a high-temperature extrusion method for preparing polypropylene cast films, the polypropylene microporous films are obtained by conducting uniaxial tension through a dry method. Production equipment / a process technique adopting the method is mature, and by means of the procedures including high-temperature extrusion, casting, annealing treatment and the uniaxial tension, efficient continuous large-scale production can be achieved; the prepared microporous films have the advantages that the number of the fish eyes is small and the puncture strength is high, and the problem of melt shaking during casting is solved.

Description

technical field [0001] The invention belongs to the field of preparation of lithium battery separators, in particular to a preparation method of polyolefin microporous membranes. Background technique [0002] Traditional fuel vehicles are currently one of the main sources of air pollution. Improving emission standards and other means can only alleviate the degree of pollution, but cannot fundamentally eliminate the source of pollution. The new energy automobile industry has always been an industry that the automobile industry and even governments of various countries are keen to invest in. The lithium battery industry report predicts that the output of electric vehicles will reach 13.14 million in 2020, which is 5.5 times that of 2010. Among them, the output of plug-in hybrid electric vehicles will increase by 35 times to 1.4 million, and the output of pure electric vehicles will reach 750,000, an increase of 75 times. [0003] Lithium batteries have the characteristics of ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B29C69/00B29C47/92B29C55/04B29K23/00B29L7/00B29C48/92
Inventor 李泽涛刘孟权陈秀峰
Owner SHENZHEN SENIOR TECH MATERIAL