CA2408718A1 - Diffusion membrane - Google Patents
Diffusion membrane Download PDFInfo
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- CA2408718A1 CA2408718A1 CA002408718A CA2408718A CA2408718A1 CA 2408718 A1 CA2408718 A1 CA 2408718A1 CA 002408718 A CA002408718 A CA 002408718A CA 2408718 A CA2408718 A CA 2408718A CA 2408718 A1 CA2408718 A1 CA 2408718A1
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
- C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
- C08L23/04—Homopolymers or copolymers of ethene
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
- B01D71/06—Organic material
- B01D71/24—Rubbers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
- B01D71/06—Organic material
- B01D71/26—Polyalkenes
- B01D71/261—Polyethylene
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
- B01D71/06—Organic material
- B01D71/26—Polyalkenes
- B01D71/262—Polypropylene
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
- C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
- C08L23/10—Homopolymers or copolymers of propene
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
- C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
- C08L23/16—Ethylene-propylene or ethylene-propylene-diene copolymers
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/403—Manufacturing processes of separators, membranes or diaphragms
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/403—Manufacturing processes of separators, membranes or diaphragms
- H01M50/406—Moulding; Embossing; Cutting
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/411—Organic material
- H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
- H01M50/417—Polyolefins
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
- H01M50/494—Tensile strength
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2323/00—Details relating to membrane preparation
- B01D2323/12—Specific ratios of components used
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2325/00—Details relating to properties of membranes
- B01D2325/20—Specific permeability or cut-off range
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/249921—Web or sheet containing structurally defined element or component
- Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/31504—Composite [nonstructural laminate]
- Y10T428/31855—Of addition polymer from unsaturated monomers
- Y10T428/31909—Next to second addition polymer from unsaturated monomers
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/31504—Composite [nonstructural laminate]
- Y10T428/31855—Of addition polymer from unsaturated monomers
- Y10T428/31938—Polymer of monoethylenically unsaturated hydrocarbon
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Medicinal Chemistry (AREA)
- Organic Chemistry (AREA)
- Polymers & Plastics (AREA)
- Health & Medical Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Cell Separators (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
Abstract
A diffusion membrane is a microporous sheet comprising a blend of an aliphatic polyolefin and a thermoplastic olefin (TPO) elastomer. The blend comprises less than 10 percent by weight of the elastomer. The preferred polyolefins are selected from a group consisting of polyethylene, polypropylene, copolymers thereof, and blends thereof. The preferred TPO elastomers are selected from the group consisting of ethylene-propylene rubbers (EPR), ethylene-propylene-diene terpolymer rubbers (EPDM), and combinations thereof.
Description
~ 02408718 2002-10-17 Docket 2000.83 DIFFUSION MEMBRANE
Field of the Invention A diffusion membrane is made from a blend of an aliphatic polyolefin and a thermoplastic olefin elastomer.
Background of the Invention A membrane is a structure that acts as a boundary between two distinct phases and resists the movement of molecules between those two phases to a greater or lesser extent. This movement is also referred to as diffusion. Membranes may be solid, i.e., non-porous, or semipermeable, i.e., microporous. The microporous structures act as diffusion barriers, as well a highly efficient filters in the range of molecular dimensions, allowing passage of ions, water, and other solvents in very small molecules, but being almost impermeable to macromolecules, such as proteins, and colloidal particles. These membranes have been used in industrial operations, such as waste liquor recovery, desalinization, electrolysis, osmosis, and dialysis and in commercial applications, such as flow regulators in lighters, membranes in oxygenators, separators in charge storage devices (e. g., batteries and fuel cells) .
~ 02408718 2002-10-17 _ ..
One such membrane is referred to as a "Celgard"~ membrane.
The Celgard membrane has unique physical properties and is made by a unique dry stretch process in which a semi-crystalline polymer is extruded, annealed, and then stretched to form a microporous membrane. See: Kesting, R.E., Synthetic Polymeric Membranes, 2"a Edition, John Wiley & Sons, Inc., New York, NY, 1985, pp. 290-297, and Bierenbaum, H. S. et al., "Microporous Polymeric Films," Ind.
Eng. Chem., Prod. Res. Develop., Vol. 13, No. l, 1974, pp.2-9, both are incorporated herein by reference. Such membranes have been formed into hollow fibers and flat sheets. These membranes have been useful as membranes in blood oxygenators and lighters, and as separators in batteries.
While these membranes have met with great commercial success, there is a desire, not only to enhance their performance in existing applications, but also to diversify their use to additional applications that could require greater mechanical strength while maintaining the unique microporous structure of these membranes. Accordingly, there is a need to increase the mechanical strength of such microporous membranes without sacrificing the microporous structure of these membranes.
Field of the Invention A diffusion membrane is made from a blend of an aliphatic polyolefin and a thermoplastic olefin elastomer.
Background of the Invention A membrane is a structure that acts as a boundary between two distinct phases and resists the movement of molecules between those two phases to a greater or lesser extent. This movement is also referred to as diffusion. Membranes may be solid, i.e., non-porous, or semipermeable, i.e., microporous. The microporous structures act as diffusion barriers, as well a highly efficient filters in the range of molecular dimensions, allowing passage of ions, water, and other solvents in very small molecules, but being almost impermeable to macromolecules, such as proteins, and colloidal particles. These membranes have been used in industrial operations, such as waste liquor recovery, desalinization, electrolysis, osmosis, and dialysis and in commercial applications, such as flow regulators in lighters, membranes in oxygenators, separators in charge storage devices (e. g., batteries and fuel cells) .
~ 02408718 2002-10-17 _ ..
One such membrane is referred to as a "Celgard"~ membrane.
The Celgard membrane has unique physical properties and is made by a unique dry stretch process in which a semi-crystalline polymer is extruded, annealed, and then stretched to form a microporous membrane. See: Kesting, R.E., Synthetic Polymeric Membranes, 2"a Edition, John Wiley & Sons, Inc., New York, NY, 1985, pp. 290-297, and Bierenbaum, H. S. et al., "Microporous Polymeric Films," Ind.
Eng. Chem., Prod. Res. Develop., Vol. 13, No. l, 1974, pp.2-9, both are incorporated herein by reference. Such membranes have been formed into hollow fibers and flat sheets. These membranes have been useful as membranes in blood oxygenators and lighters, and as separators in batteries.
While these membranes have met with great commercial success, there is a desire, not only to enhance their performance in existing applications, but also to diversify their use to additional applications that could require greater mechanical strength while maintaining the unique microporous structure of these membranes. Accordingly, there is a need to increase the mechanical strength of such microporous membranes without sacrificing the microporous structure of these membranes.
These membranes are typically made of polyolefins, such as polypropylene and polyethylene. It is known in the film art that mechanical strength of: non-porous polypropylene films may be increased by the addition of polyisobutylene rubber and fillers, see U.S. Patent 4,911,985; non-porous packaging films may be improved by the addition of an elastomer, see U.S. Patent 5,071,686; and non-porous high density polyethylene films may be improved by addition of elastomers, see U.S. Patent 5,635,262.
None of these prior art references, however, teach or suggest how one may improve the properties of a microporous membrane while maintaining the porosity of the membrane. European Publication No.
1,153,967 discloses a microporous membrane made of a resin composition comprising an alicyclic compound and a resin selected from the group consisting of polyolefins, thermoplastic elastomers, and graft polymers.
Accordingly, there is a need in the art for a method of improving the mechanical strength of a microporous membrane while maintaining the porosity of the membrane.
Summary of the Invention A diffusion membrane is a microporous sheet comprising a blend of an aliphatic polyolefin and a thermoplastic olefin (TPO) elastomer. The blend comprises less than 10 percent by weight of the elastomer. The preferred polyolefins are selected from a group consisting of polyethylene, polypropylene, copolymers thereof, and blends thereof. The preferred TPO elastomers are selected from the group consisting of ethylene-propylene rubbers (EPR), ethylene-propylene-dime terpolymers rubbers (EPDM), and combinations thereof .
Detailed Description of the Invention The membrane disclosed herein is a microporous membrane. See Kesting, Ibid., incorporated herein by reference. The membrane has a thickness less than 2 mils (50 microns), preferably less than 1 mil (25 microns), and most preferably, in the range of 0.35 to 0.9 mils (8 to 23 microns) in thickness. The membrane will have a machine direction (MD) tensile strength (TS, ASTM D638) greater than 1,500 kg/cm2 and a puncture strength (PS, test method described below) greater than 400 g/mil. The microporous membrane will have a Gurley (ASTM-D726B) of less than 35 seconds/10 cc, preferably less than 25 secs/lOcc. These membranes may be used as, among other things, battery separators. These membranes may be made by a phase inversion method or a dry stretch method (Kesting, Ibid., pages 237-297, and Bierenbaum, Ibid., both are incorporated herein by reference), but the latter method is preferred.
None of these prior art references, however, teach or suggest how one may improve the properties of a microporous membrane while maintaining the porosity of the membrane. European Publication No.
1,153,967 discloses a microporous membrane made of a resin composition comprising an alicyclic compound and a resin selected from the group consisting of polyolefins, thermoplastic elastomers, and graft polymers.
Accordingly, there is a need in the art for a method of improving the mechanical strength of a microporous membrane while maintaining the porosity of the membrane.
Summary of the Invention A diffusion membrane is a microporous sheet comprising a blend of an aliphatic polyolefin and a thermoplastic olefin (TPO) elastomer. The blend comprises less than 10 percent by weight of the elastomer. The preferred polyolefins are selected from a group consisting of polyethylene, polypropylene, copolymers thereof, and blends thereof. The preferred TPO elastomers are selected from the group consisting of ethylene-propylene rubbers (EPR), ethylene-propylene-dime terpolymers rubbers (EPDM), and combinations thereof .
Detailed Description of the Invention The membrane disclosed herein is a microporous membrane. See Kesting, Ibid., incorporated herein by reference. The membrane has a thickness less than 2 mils (50 microns), preferably less than 1 mil (25 microns), and most preferably, in the range of 0.35 to 0.9 mils (8 to 23 microns) in thickness. The membrane will have a machine direction (MD) tensile strength (TS, ASTM D638) greater than 1,500 kg/cm2 and a puncture strength (PS, test method described below) greater than 400 g/mil. The microporous membrane will have a Gurley (ASTM-D726B) of less than 35 seconds/10 cc, preferably less than 25 secs/lOcc. These membranes may be used as, among other things, battery separators. These membranes may be made by a phase inversion method or a dry stretch method (Kesting, Ibid., pages 237-297, and Bierenbaum, Ibid., both are incorporated herein by reference), but the latter method is preferred.
The microporous membrane will consist of a blend of an aliphatic polyolefin and a thermoplastic olefin (TPO) elastomer.
The blend will consist of less than 10 percent by blend weight of the elastomer; preferably in the range of 2 to 10 percent by blend weight of the elastomer; and most preferred, 3 to 7 percent by blend weight of the elastomer.
An aliphatic polyolefin, as used herein, is directed to a class or group name for thermoplastic polymers derived from single olefins, and that are characterized by straight- or branched- chain arrangement of the constituent carbon atoms. The important ones include polyethylenes, polypropylenes, polybutenes, polyisoprenes, polymethylpentenes, and their copolymers. Preferably, they are selected from the group consisting of polyethylene, polypropylene, copolymers thereof, and blends thereof. Polyethylene refers preferably to a high-density polyethylene having a density (ASTM
D792) ranging from 0.95 to 0.96 g/cm2, and a melt flow index (MFI, ASTM D1238, 190°C per 2.16 kilograms) ranging from 0.38 to 0.42 dg/minutes. Polypropylene refers preferably to an isotactic homopolymer with a density (ASTM D1505) of about 0.905 and a MFI
(ASTM 1238, 230°C/2.16 kilograms) of 1.5.
A TPO elastomer is a copolymer or terpolymer based on polyolefin monomers. For example, ethylene-propylene rubber (EPR) - 5 _ is a copolymer and ethylene-propylene-dime (EPDM) rubber refers to a terpolymer. Preferably, the EPR has a Mooney viscosity (ASTM
D1646) of about 51 with an ethylene monomer content (ASTM D3900) of about 61 percent by weight and a narrow molecular weight distribution. Preferably, the EPDM has a Mooney viscosity in the range of 45 to 52, an ethylene content of 69 to 70 percent by weight, and a dime content of 0.5 to 3.4 percent by weight, and the molecular weight distribution may be either broad or narrow.
The instant invention will be more fully appreciated with reference to the following examples.
Examples Examples 1, 3, 5, and 7 are non-porous, precursor (i.e., before stretching to induce porosity) films. Examples 2, 4, 6, and 8 are microporous membranes. All materials were blended by conventional melt blending techniques. Examples 1 and 2 are a blend of polyethylene (HDPE, density - 0.959, MFI - 0.42, medium molecular weight, narrow molecular weight distribution) and an EPDM
rubber (Mooney viscosity - 45, percent ethylene - 69, percent dime - 0.5, narrow molecular weight distribution). Examples 3 and 4 are a blend of a polypropylene (isotactic homopolymer, density - 0.905, MFI - 1.5) and an EPDM rubber (same as in Examples 1 and 2).
Examples 5 and 6 are a blend of a polypropylene (same as in 6 _ Examples 3 and 4) and an EPR rubber (Mooney viscosity - 51, percent ethylene - 61, narrow molecular weight distribution). Examples 7 and 8 are a blend of a polyethylene (HDPE, density - 0.961, MFI -0.38) and an EPDM rubber (Mooney viscosity - 52, percent ethylene -70, percent dime - 3.4, broad molecular weight distribution). The membranes were made in a conventional manner by a dry stretch process in which the blend is extruded, annealed, and then stretched to form the microporous membrane.
Test Methods All the test methods are conventional. Gurley (sec/lOcc or sec) was measured according to ASTM-D726(B). Puncture strength (PS) was measured as follows: Ten measurements are made across the width of stretched product and averaged. A MiTech Stevens LFRA
Texture Analyzer is used. The needle is 1.65 mm in diameter with a 0.5 mm radius. The rate of descent is 2 mm/sec and the amount of deflection is 6 mm. The film is held tight in the clamping device with a central hole of 11.3 mm. The displacement (in mm) of the film that was pierced by the needle was recorded against the resistance force (in gram force) developed by the film. The penetration energy (puncture strength) was defined as the product of the resistance force and the displacement at the maximum point.
Tensile strength (TS), in the machine direction, was measured _ 7 _ according to ASTM D638 using a 2-inch X 0.5-inch sample, 5 measurements were averaged and the average was reported.
TABLE Z
EXAMPLE Blend Thickness Tensile Puncture Gurley Elastomer mil (TS) (PS) sec/lOcc kg/cm2 g/mil 1 0 0.56 928 293_ NA
' 5 0.61 _ 1184 329 _ NA
10 0.45 1250 378 NA
2 0 0.44 1173 373 22 5 0.48 1837 468 23 10 0.40 1828 510 29 3 0 0.84 972 275 NA
_ 5 0.84 1049 310 NA
10 0.60 1120 352 NA
4 0 0._75 1446__ 353 19 __ 5 0.69 1580 426 22 10 0.49 1669 494 123 0 0.83 1040 311 NA
5 _0.70 1137 350 NA
10 0_.59 1420 408 NA
6 0 0.'75 -- 386 26 5 0_.65 -- 482 20 10 0.59 -- 462 68 7 0 0._88 -- 199 NA
5 0_._86 -- 263 NA
10 0.88 -- 299 NA
The blend will consist of less than 10 percent by blend weight of the elastomer; preferably in the range of 2 to 10 percent by blend weight of the elastomer; and most preferred, 3 to 7 percent by blend weight of the elastomer.
An aliphatic polyolefin, as used herein, is directed to a class or group name for thermoplastic polymers derived from single olefins, and that are characterized by straight- or branched- chain arrangement of the constituent carbon atoms. The important ones include polyethylenes, polypropylenes, polybutenes, polyisoprenes, polymethylpentenes, and their copolymers. Preferably, they are selected from the group consisting of polyethylene, polypropylene, copolymers thereof, and blends thereof. Polyethylene refers preferably to a high-density polyethylene having a density (ASTM
D792) ranging from 0.95 to 0.96 g/cm2, and a melt flow index (MFI, ASTM D1238, 190°C per 2.16 kilograms) ranging from 0.38 to 0.42 dg/minutes. Polypropylene refers preferably to an isotactic homopolymer with a density (ASTM D1505) of about 0.905 and a MFI
(ASTM 1238, 230°C/2.16 kilograms) of 1.5.
A TPO elastomer is a copolymer or terpolymer based on polyolefin monomers. For example, ethylene-propylene rubber (EPR) - 5 _ is a copolymer and ethylene-propylene-dime (EPDM) rubber refers to a terpolymer. Preferably, the EPR has a Mooney viscosity (ASTM
D1646) of about 51 with an ethylene monomer content (ASTM D3900) of about 61 percent by weight and a narrow molecular weight distribution. Preferably, the EPDM has a Mooney viscosity in the range of 45 to 52, an ethylene content of 69 to 70 percent by weight, and a dime content of 0.5 to 3.4 percent by weight, and the molecular weight distribution may be either broad or narrow.
The instant invention will be more fully appreciated with reference to the following examples.
Examples Examples 1, 3, 5, and 7 are non-porous, precursor (i.e., before stretching to induce porosity) films. Examples 2, 4, 6, and 8 are microporous membranes. All materials were blended by conventional melt blending techniques. Examples 1 and 2 are a blend of polyethylene (HDPE, density - 0.959, MFI - 0.42, medium molecular weight, narrow molecular weight distribution) and an EPDM
rubber (Mooney viscosity - 45, percent ethylene - 69, percent dime - 0.5, narrow molecular weight distribution). Examples 3 and 4 are a blend of a polypropylene (isotactic homopolymer, density - 0.905, MFI - 1.5) and an EPDM rubber (same as in Examples 1 and 2).
Examples 5 and 6 are a blend of a polypropylene (same as in 6 _ Examples 3 and 4) and an EPR rubber (Mooney viscosity - 51, percent ethylene - 61, narrow molecular weight distribution). Examples 7 and 8 are a blend of a polyethylene (HDPE, density - 0.961, MFI -0.38) and an EPDM rubber (Mooney viscosity - 52, percent ethylene -70, percent dime - 3.4, broad molecular weight distribution). The membranes were made in a conventional manner by a dry stretch process in which the blend is extruded, annealed, and then stretched to form the microporous membrane.
Test Methods All the test methods are conventional. Gurley (sec/lOcc or sec) was measured according to ASTM-D726(B). Puncture strength (PS) was measured as follows: Ten measurements are made across the width of stretched product and averaged. A MiTech Stevens LFRA
Texture Analyzer is used. The needle is 1.65 mm in diameter with a 0.5 mm radius. The rate of descent is 2 mm/sec and the amount of deflection is 6 mm. The film is held tight in the clamping device with a central hole of 11.3 mm. The displacement (in mm) of the film that was pierced by the needle was recorded against the resistance force (in gram force) developed by the film. The penetration energy (puncture strength) was defined as the product of the resistance force and the displacement at the maximum point.
Tensile strength (TS), in the machine direction, was measured _ 7 _ according to ASTM D638 using a 2-inch X 0.5-inch sample, 5 measurements were averaged and the average was reported.
TABLE Z
EXAMPLE Blend Thickness Tensile Puncture Gurley Elastomer mil (TS) (PS) sec/lOcc kg/cm2 g/mil 1 0 0.56 928 293_ NA
' 5 0.61 _ 1184 329 _ NA
10 0.45 1250 378 NA
2 0 0.44 1173 373 22 5 0.48 1837 468 23 10 0.40 1828 510 29 3 0 0.84 972 275 NA
_ 5 0.84 1049 310 NA
10 0.60 1120 352 NA
4 0 0._75 1446__ 353 19 __ 5 0.69 1580 426 22 10 0.49 1669 494 123 0 0.83 1040 311 NA
5 _0.70 1137 350 NA
10 0_.59 1420 408 NA
6 0 0.'75 -- 386 26 5 0_.65 -- 482 20 10 0.59 -- 462 68 7 0 0._88 -- 199 NA
5 0_._86 -- 263 NA
10 0.88 -- 299 NA
8 0 _0 _. 74 -- 28_8 25 -5 0.70 -- 327 32 10 0.70 -- 355 88 The present invention made be embodied in other forms without departing from the spirit and the central attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification, as indicated the scope of the invention.
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Claims (11)
1. A method of improving a membrane comprising the step of:
providing a microporous sheet comprising a blend of an aliphatic polyolefin and less than 10 percent by blend weight of a thermoplastic olefin elastomer selected from the group of ethylene-propylene rubbers, ethylene-propylene-diene terpolymer rubbers, and combinations thereof.
providing a microporous sheet comprising a blend of an aliphatic polyolefin and less than 10 percent by blend weight of a thermoplastic olefin elastomer selected from the group of ethylene-propylene rubbers, ethylene-propylene-diene terpolymer rubbers, and combinations thereof.
2. The method of Claim 1 wherein the elastomer comprises about 2 to 10 percent by blend weight.
3. The method of Claim 2 wherein the elastomer comprises about 3 to 7 percent by blend weight.
4. The method of Claim 1 wherein the microporous sheet has a Gurley less than 35 seconds.
5. The method of Claim 4 wherein the microporous sheet has a Gurley less than 25 seconds.
6. The method of Claim 1 wherein the polyolefins selected from polyethylene, polypropylene, copolymers thereof, and blends thereof.
7. The method of Claim 1 wherein the thermoplastic olefin elastomer is selected from the group of ethylene-propylene rubbers, ethylene-propylene-diene terpolymer rubber, and combinations thereof.
8. A method of improving a membrane comprising the step of:
providing a microporous sheet having a Gurley less than 35 seconds comprising a blend of an aliphatic polyolefin selected from the group consisting of polyethylene, polypropylene, copolymers thereof, and blends thereof, and a thermoplastic olefin elastomer being selected from the group consisting of ethylene-propylene rubbers, ethylene-propylene-diene terpolymer rubbers, and combinations thereof, and the elastomer comprising 3 to 7 percent by blend weight.
providing a microporous sheet having a Gurley less than 35 seconds comprising a blend of an aliphatic polyolefin selected from the group consisting of polyethylene, polypropylene, copolymers thereof, and blends thereof, and a thermoplastic olefin elastomer being selected from the group consisting of ethylene-propylene rubbers, ethylene-propylene-diene terpolymer rubbers, and combinations thereof, and the elastomer comprising 3 to 7 percent by blend weight.
9. A diffusion membrane comprising:
a microporous sheet comprising a blend of an aliphatic polyolefin and a thermoplastic olefin elastomer, the blend comprising less than 10 percent by blend weight of the elastomer, the polyolefin being selected from the group consisting of polyethylene, polypropylene, copolymers thereof, and blends thereof, the thermoplastic olefin elastomer being selected from the group consisting of ethylene-propylene rubbers, ethylene-propylene-diene terpolymer rubbers, and combinations thereof.
a microporous sheet comprising a blend of an aliphatic polyolefin and a thermoplastic olefin elastomer, the blend comprising less than 10 percent by blend weight of the elastomer, the polyolefin being selected from the group consisting of polyethylene, polypropylene, copolymers thereof, and blends thereof, the thermoplastic olefin elastomer being selected from the group consisting of ethylene-propylene rubbers, ethylene-propylene-diene terpolymer rubbers, and combinations thereof.
10. The membrane of Claim 9 wherein the blend comprises between 2 and 10 percent by blend weight.
11. The membrane of Claim 10 wherein the blend comprises between 3 and 7 percent by blend weight.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US10/005,846 US20030104236A1 (en) | 2001-12-03 | 2001-12-03 | Diffusion membrane |
| US10/005,846 | 2001-12-03 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2408718A1 true CA2408718A1 (en) | 2003-06-03 |
Family
ID=21718041
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002408718A Abandoned CA2408718A1 (en) | 2001-12-03 | 2002-10-17 | Diffusion membrane |
Country Status (8)
| Country | Link |
|---|---|
| US (1) | US20030104236A1 (en) |
| EP (1) | EP1316356A3 (en) |
| JP (1) | JP3711347B2 (en) |
| KR (1) | KR20030045608A (en) |
| CN (1) | CN1263795C (en) |
| CA (1) | CA2408718A1 (en) |
| SG (1) | SG112854A1 (en) |
| TW (1) | TWI228055B (en) |
Families Citing this family (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7910260B2 (en) * | 2004-11-01 | 2011-03-22 | GM Global Technology Operations LLC | Method for stabilizing polyelectrolyte membrane films used in fuel cells |
| US8053048B2 (en) | 2005-04-25 | 2011-11-08 | Baxter International Inc. | Overpouch film and container and method of making same |
| JP5539604B2 (en) * | 2005-12-13 | 2014-07-02 | 三菱樹脂株式会社 | Method for producing porous body and porous body |
| US8795565B2 (en) * | 2006-02-21 | 2014-08-05 | Celgard Llc | Biaxially oriented microporous membrane |
| US8388878B2 (en) * | 2008-03-31 | 2013-03-05 | Ppg Industries Ohio, Inc. | Method for producing microporous sheet |
| EP2130860A1 (en) * | 2008-06-06 | 2009-12-09 | Borealis Technology Oy | Polymer |
| US9976021B2 (en) | 2009-11-18 | 2018-05-22 | Exxonmobil Chemical Patents Inc. | Compositions comprising EPDM and a polyolefin elastomer, preparation and use thereof |
| HUE043797T2 (en) | 2010-12-28 | 2019-09-30 | Asahi Chemical Ind | Polyolefin-based porous film and method for producing the same |
| CN102751459B (en) | 2011-04-22 | 2016-03-23 | 天津东皋膜技术有限公司 | Rear cross-linked rubber, the micro-porous septum of composite polyolefine material nanometer and manufacture method thereof |
| CN103178227B (en) * | 2011-12-22 | 2016-05-11 | 天津东皋膜技术有限公司 | There is the micro-porous septum of polyethylene based composition of heat pressure adhesive characteristic |
| CN103184013A (en) * | 2011-12-28 | 2013-07-03 | 天津东皋膜技术有限公司 | Polyvinyl composite microporous membrane with thermocompression bonding characteristic |
| CN104245822B (en) * | 2012-03-09 | 2016-08-10 | 埃克森美孚化学专利公司 | Comprise the compositions of EPDM and polyolefin elastomer, its preparation and purposes |
| US10537856B2 (en) | 2014-08-26 | 2020-01-21 | Mitsubishi Chemical Corporation | Hollow fiber membrane and hollow fiber membrane module |
| WO2019103947A2 (en) | 2017-11-21 | 2019-05-31 | Asahi Kasei Kabushiki Kaisha | Separator for electric storage device |
| CN109888156B (en) * | 2019-03-15 | 2022-02-11 | 深圳市飞鹏新能源科技有限公司 | Composite lithium ion battery diaphragm and preparation process thereof |
| CN116615490B (en) * | 2020-10-30 | 2026-04-14 | 旭化成电池隔膜株式会社 | Microporous polyolefin membrane |
| CN115473009A (en) * | 2021-06-10 | 2022-12-13 | 恒大新能源技术(深圳)有限公司 | Battery diaphragm, preparation method thereof and secondary battery |
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| FR1544807A (en) * | 1967-09-27 | 1968-11-08 | Celanese Corp | Open cell film |
| US3679540A (en) * | 1970-11-27 | 1972-07-25 | Celanese Corp | Reinforced microporous film |
| JPS60109666A (en) * | 1983-11-16 | 1985-06-15 | Mitsubishi Plastics Ind Ltd | Diaphragm in filter press |
| US5071686A (en) * | 1985-11-29 | 1991-12-10 | Genske Roger P | Films of polypropylene blends and polyethylene blends and articles made therewith |
| US4722961A (en) * | 1986-06-16 | 1988-02-02 | Union Carbide Corporation | Roofing membranes |
| JP2602016B2 (en) * | 1986-09-01 | 1997-04-23 | 日東電工株式会社 | Reinforced porous sheet |
| JPS63309251A (en) * | 1987-06-09 | 1988-12-16 | Molten Corp | Denture base having elastic lining material and its preparation |
| IT1217394B (en) * | 1988-04-07 | 1990-03-22 | Ausimont Spa | BITUMEN BASED WATERPROOFING MEMBRANES |
| JPH0220531A (en) * | 1988-07-07 | 1990-01-24 | Nitto Denko Corp | Preparation of hydrophilic porous film |
| US4923650A (en) * | 1988-07-27 | 1990-05-08 | Hercules Incorporated | Breathable microporous film and methods for making it |
| US4911985A (en) * | 1989-02-21 | 1990-03-27 | Allied-Signal Inc. | High density polyethylene compositions containing polyisobutylene rubber and filler |
| US4975469A (en) * | 1989-03-20 | 1990-12-04 | Amoco Corporation | Oriented porous polypropylene films |
| JPH06163023A (en) * | 1992-09-03 | 1994-06-10 | Asahi Chem Ind Co Ltd | Battery separator |
| US5938874A (en) * | 1994-02-11 | 1999-08-17 | Allegiance Corporation | Process of making microporous film |
| JP3449656B2 (en) * | 1994-11-11 | 2003-09-22 | 旭化成株式会社 | Battery separator |
| US5635262A (en) * | 1994-12-12 | 1997-06-03 | Exxon Chemical Patents Inc. | High molecular weight high density polyethylene with improved tear resistance |
| US6096213A (en) * | 1998-08-14 | 2000-08-01 | 3M Innovative Properties Company | Puncture-resistant polyolefin membranes |
| US6602593B1 (en) * | 1999-08-30 | 2003-08-05 | Celgard Inc. | Battery separators with reduced splitting propensity |
-
2001
- 2001-12-03 US US10/005,846 patent/US20030104236A1/en not_active Abandoned
-
2002
- 2002-10-17 CA CA002408718A patent/CA2408718A1/en not_active Abandoned
- 2002-10-18 SG SG200206361A patent/SG112854A1/en unknown
- 2002-10-25 TW TW091125050A patent/TWI228055B/en not_active IP Right Cessation
- 2002-11-09 EP EP02025147A patent/EP1316356A3/en not_active Withdrawn
- 2002-11-28 CN CNB021524440A patent/CN1263795C/en not_active Expired - Fee Related
- 2002-11-30 KR KR1020020075638A patent/KR20030045608A/en not_active Ceased
- 2002-12-03 JP JP2002351500A patent/JP3711347B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| EP1316356A2 (en) | 2003-06-04 |
| US20030104236A1 (en) | 2003-06-05 |
| CN1263795C (en) | 2006-07-12 |
| CN1424348A (en) | 2003-06-18 |
| JP2003192814A (en) | 2003-07-09 |
| TWI228055B (en) | 2005-02-21 |
| EP1316356A3 (en) | 2005-02-23 |
| JP3711347B2 (en) | 2005-11-02 |
| SG112854A1 (en) | 2005-07-28 |
| KR20030045608A (en) | 2003-06-11 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |