WO2007119508A1 - ポリテトラフルオロエチレン多孔質膜の製造方法とフィルター濾材ならびにフィルターユニット - Google Patents
ポリテトラフルオロエチレン多孔質膜の製造方法とフィルター濾材ならびにフィルターユニット Download PDFInfo
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- WO2007119508A1 WO2007119508A1 PCT/JP2007/056093 JP2007056093W WO2007119508A1 WO 2007119508 A1 WO2007119508 A1 WO 2007119508A1 JP 2007056093 W JP2007056093 W JP 2007056093W WO 2007119508 A1 WO2007119508 A1 WO 2007119508A1
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- porous membrane
- ptfe
- polytetrafluoroethylene
- sheet
- filter medium
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C55/00—Shaping by stretching, e.g. drawing through a die; Apparatus therefor
- B29C55/005—Shaping by stretching, e.g. drawing through a die; Apparatus therefor characterised by the choice of materials
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C55/00—Shaping by stretching, e.g. drawing through a die; Apparatus therefor
- B29C55/02—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets
- B29C55/10—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial
- B29C55/12—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial biaxial
- B29C55/14—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial biaxial successively
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D39/00—Filtering material for liquid or gaseous fluids
- B01D39/14—Other self-supporting filtering material ; Other filtering material
- B01D39/16—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D39/00—Filtering material for liquid or gaseous fluids
- B01D39/14—Other self-supporting filtering material ; Other filtering material
- B01D39/16—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres
- B01D39/1692—Other shaped material, e.g. perforated or porous sheets
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/22—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by diffusion
- B01D53/228—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by diffusion characterised by specific membranes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
- B01D67/0002—Organic membrane manufacture
- B01D67/0023—Organic membrane manufacture by inducing porosity into non porous precursor membranes
- B01D67/0025—Organic membrane manufacture by inducing porosity into non porous precursor membranes by mechanical treatment, e.g. pore-stretching
- B01D67/0027—Organic membrane manufacture by inducing porosity into non porous precursor membranes by mechanical treatment, e.g. pore-stretching by stretching
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- 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
- B01D71/30—Polyalkenyl halides
- B01D71/32—Polyalkenyl halides containing fluorine atoms
- B01D71/36—Polytetrafluoroethene
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C55/00—Shaping by stretching, e.g. drawing through a die; Apparatus therefor
- B29C55/02—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets
- B29C55/10—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial
- B29C55/12—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial biaxial
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
- C08J5/18—Manufacture of films or sheets
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2325/00—Details relating to properties of membranes
- B01D2325/04—Characteristic thickness
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2027/00—Use of polyvinylhalogenides or derivatives thereof as moulding material
- B29K2027/12—Use of polyvinylhalogenides or derivatives thereof as moulding material containing fluorine
- B29K2027/18—PTFE, i.e. polytetrafluorethene, e.g. ePTFE, i.e. expanded polytetrafluorethene
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
- B29K2105/04—Condition, form or state of moulded material or of the material to be shaped cellular or porous
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
- B29K2995/0037—Other properties
- B29K2995/0065—Permeability to gases
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
- B29L2007/00—Flat articles, e.g. films or sheets
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2327/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers
- C08J2327/02—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment
- C08J2327/12—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment containing fluorine atoms
- C08J2327/18—Homopolymers or copolymers of tetrafluoroethylene
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- 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
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S55/00—Gas separation
- Y10S55/05—Methods of making filter
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- 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
- Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
- Y10T428/24479—Structurally defined web or sheet [e.g., overall dimension, etc.] including variation in thickness
- Y10T428/24496—Foamed or cellular component
- Y10T428/24504—Component comprises a polymer [e.g., rubber, 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
- Y10T428/249921—Web or sheet containing structurally defined element or component
- Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
- Y10T428/249962—Void-containing component has a continuous matrix of fibers only [e.g., porous paper, etc.]
- Y10T428/249964—Fibers of defined composition
-
- 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.]
- Y10T428/249978—Voids specified as micro
Definitions
- the present invention relates to a method for producing a polytetrafluoroethylene porous membrane.
- the present invention also relates to a filter medium having a polytetrafluoroethylene porous membrane obtained by the production method and a filter unit.
- electrostatic filter media including synthetic fiber nonwoven fabrics such as polypropylene, or mechanical filter media based on glass fibers are known. ing.
- these filter media there is a problem with the filter media that can suppress deterioration with time of the collection efficiency of particles contained in the gas that passes through the filter media.
- self-generated dust may be generated due to small fibers existing in the filter media or bending, and electrostatic performance is degraded by oil mist in the gas, resulting in increased collection efficiency. May decrease.
- a mechanical filter medium using glass fiber as a base material it has been difficult to avoid an increase in pressure loss in order to achieve high collection efficiency.
- a filter medium having a polytetrafluoroethylene (PTFE) porous membrane has attracted attention as a filter medium that can solve these problems.
- PTFE porous membrane is generally obtained by stretching an unfired PTFE sheet. It is formed.
- PTFE porous membranes produce little self-dusting even during bending, and have a high collection efficiency by making their average pore diameter fine (usually 0. or less) and thin (usually less). Compatibility with low pressure loss is possible.
- a fine average pore diameter, thinness, and film thickness are realized by biaxially stretching an unfired PTFE sheet at a temperature below the melting point of PTFE.
- the PTFE porous membrane disclosed in Document 2 has high collection efficiency and low pressure. Since the balance with the loss is realized by the fine average pore diameter and the thin film thickness, the strength as the film cannot be secured sufficiently, and defects such as pin holes may occur.
- the present invention provides a PTFE porous membrane that has both a high trapping efficiency and a low pressure loss while having a larger average pore diameter and a larger thickness than those of the conventional PTFE porous membrane.
- the purpose is to provide a manufacturing method.
- an unsintered PTFE sheet is stretched 5 to 30 times in a predetermined direction at a temperature equal to or higher than the melting point of PTFE, and the stretched sheet is less than the melting point. Then, the film is further stretched 5 to 40 times in a direction different from the predetermined direction, and then heated to a temperature equal to or higher than the melting point.
- the filter medium of the present invention is a filter medium that collects particles contained in the gas to be filtered, and includes the PTFE porous membrane obtained by the production method of the present invention.
- the filter unit of the present invention is a filter unit comprising a filter medium that collects particles contained in the gas to be filtered, and a support frame that supports the filter medium. This is a filter medium.
- an unsintered PTFE sheet is stretched at a temperature not lower than the melting point (327 ° C) of PTFE (stretching A), and then the stretched sheet is less than the melting point. After further stretching at the same temperature (stretching B), heating to a temperature equal to or higher than the above melting point makes the average pore diameter larger and the film thickness larger than before, but with high collection efficiency and low pressure loss. It is possible to form a porous PTFE membrane that balances
- Such a porous PTFE membrane is also excellent in strength and can suppress the occurrence of defects such as pinholes, and is therefore suitable for use as a filter medium!
- FIG. 1 is a perspective view schematically showing an example of a filter unit of the present invention.
- FIG. 2 is a view showing the structure of a PTFE porous membrane sample (Example 1) produced in the example.
- FIG. 3 is a view showing the structure of a PTFE porous membrane sample (Comparative Example 1) produced in the example.
- the specific method is not particularly limited.
- an unsintered PTFE sheet may be stretched in a heating furnace maintained at a temperature higher than the melting point. At this time, the PTFE sheet can be stretched at a temperature equal to or higher than the melting point by appropriately setting the time during which the PTFE sheet is positioned in the heating furnace.
- the direction of stretch A is not particularly limited, but may be, for example, the longitudinal direction when the unfired PTFE sheet has a strip shape.
- the stretch A ratio is preferably about 5 to 25 times.
- the temperature at which the stretching A is carried out is usually about 327 to 400 ° C, preferably 350 ° C or higher.
- stretching A it is considered that fibrils extending in the stretching direction are formed in the PTFE sheet, and nodes in which PTFE is partially aggregated are formed. Moreover, since it extends at a temperature higher than the melting point of PTFE, excessive thinning of the PTFE sheet can be suppressed.
- stretching B the specific method is not particularly limited as long as the PTFE sheet subjected to stretching A is stretched 5 to 40 times in a direction different from the direction of stretching A at a temperature lower than the melting point of PTFE.
- a PTFE sheet subjected to stretching A may be stretched in a heating furnace maintained at a temperature lower than the melting point. At this time, the PTFE sheet can be stretched at a temperature lower than the melting point by appropriately setting the time for which the PTFE sheet is located in the heating furnace.
- the direction of stretch B is not particularly limited as long as it is different from the direction of stretch A.
- the direction of stretch B may be any direction as long as it is perpendicular to the direction of stretch A in the plane of the PTFE sheet.
- the PTFE sheet has a strip shape, it may be in the width direction.
- the stretch B ratio is preferably about 5 to 30 times.
- the area stretch ratio indicated by the product of the stretch A ratio and the stretch B ratio is preferably 300 times or less.
- the area stretch ratio exceeds 300 times, the average pore diameter in the formed PTFE porous membrane increases. The trapping efficiency may be excessively reduced.
- the area stretch ratio is preferably 250 times or less, more preferably 150 times or less.
- the temperature at which the stretching B is carried out is usually 25 ° C or more, preferably about 40 to 200 ° C, more preferably about 100 to 200 ° C.
- Stretching B may be performed continuously following stretching A.
- the stretched PTFE sheet is heated to a temperature equal to or higher than the melting point of PTFE and heat-treated.
- the specific method of heat treatment is not particularly limited.
- the stretched PTFE sheet may be stored in a heating furnace maintained at a temperature equal to or higher than the melting point. At this time, the PTFE sheet can be heat-treated at a temperature equal to or higher than the melting point by appropriately setting the time during which the PTFE sheet is accommodated in the heating furnace.
- the heat treatment is preferably tool that temperature be carried out in the state of fixing the size of the PTFE sheet, 350 ⁇ 400 o C about force preferably! / ⁇ .
- the heat treatment may be performed continuously following the stretching B.
- the inventors of the present invention have made the PTFE porous membrane larger in average pore diameter and thicker by using the above-described manufacturing method, and have high collection efficiency and low pressure loss. And found that both can be achieved.
- the fibrils are not made finer than before, for example, the area of the nodes is 1 ⁇ m 2 or more, and the distance between the nodes is several tens to 100.
- a porous PTFE membrane of about m can be formed.
- the method for forming the unfired PTFE sheet used in the production method of the present invention is not particularly limited.
- a mixture of PTFE fine powder (fine powder) and a liquid lubricant may be selected for extrusion and rolling force. It may be formed into a sheet by at least one method.
- the type of PTFE fine powder is not particularly limited, and a commercially available product may be used.
- Examples of commercially available PTF E fine powders include Polyflon F-104 (Daikin Industries), Fullon CD-123 (Asahi ICI Fluoropolymers), Teflon 6J (Mitsui's DuPont Fluorochemicals), and the like. .
- the liquid lubricant is a substance that can wet the surface of the PTFE fine powder and can be removed by means such as evaporation or extraction after the mixture is formed into a sheet.
- the liquid lubricant various alcohols, ketones, esters and the like may be used in addition to hydrocarbon oils such as liquid paraffin, naphtha, white oil, toluene, and xylene.
- the mixing ratio of the PTFE fine powder and the liquid lubricant may be appropriately adjusted according to the type of the PTFE fine powder and the liquid lubricant, or the molding method of the PTFE sheet.
- the liquid lubricant is about 5 to 50 parts by weight with respect to 100 parts by weight.
- Specific methods of extrusion and Z or rolling are not particularly limited.
- the mixture is extruded into a rod shape
- the obtained rod-shaped formed body is rolled with a pair of rolls to form a sheet. You may shape
- the mixture may be extruded into a sheet as it is, or may be further rolled after being extruded into a sheet.
- the thickness of the unsintered PTFE sheet is usually about 0.05 to 0.5 mm as long as it is appropriately adjusted depending on the thickness of the porous PTFE membrane to be obtained.
- the liquid lubricant is preferably heated before being subjected to the above stretching A! /, And is preferably removed from the PTFE sheet by a technique such as extraction.
- a PTFE porous film having the following characteristics can be formed.
- a PTFE porous membrane having an average pore diameter of 1 to 5 ⁇ m can be formed.
- the average pore diameter can be controlled mainly by adjusting the ratio of stretching A and B. When the ratio is increased, the average pore diameter of the obtained PTFE porous membrane can be increased.
- the thickness is 5 ⁇ m or more and 35 ⁇ m or less, preferably more than 10 ⁇ m.
- the pressure loss that occurs when gas is permeated at a flow rate of 5.3 cmZsec is 1 m or less.
- a PTFE porous film of OOPa or less can be formed.
- a PTFE porous membrane having a thickness of more than 35 m and not more than 50 m and a pressure loss generated when gas is permeated at a flow rate of 5.3 cmZS is not more than 200 Pa. Can be formed.
- a PTFE porous membrane that collects 89% or more of the particles is collected. Can be formed. 90% or more of the particles are mainly adjusted by adjusting the draw ratios A and B.
- PTFE porous membrane 99% or more, or 99.97% or more of PTFE porous membrane can be formed.
- a PTFE porous membrane that collects 99.97% or more of the particles can be used as a so-called HEPA filter.
- a PTFE porous film having a needle penetration strength of 0.2 N / mm 2 or more, preferably 0.3 NZmm 2 or more can be formed in a predetermined needle penetration test. Details of the needle penetration test will be described later in Examples.
- the filter medium of the present invention is provided with the PTFE porous membrane (PTFE porous membrane of the present invention) obtained by the production method of the present invention, and has both high collection efficiency and low pressure loss. It can be.
- the collection efficiency and pressure loss in the filter medium of the present invention basically depend on the collection efficiency and pressure loss in the PTFE porous membrane of the present invention described above, although it depends on the type and number of layers of the filter medium. It is the same.
- the filter medium of the present invention may include a layer other than the PTFE porous membrane of the present invention.
- the filter medium may include a breathable support material that supports the porous membrane. In this case, the strength and life of the filter medium can be further improved.
- the filter medium of the present invention includes a PTFE porous membrane and a breathable support material
- the two may be simply overlapped, or may be integrated by a technique such as adhesive lamination or thermal lamination. May be.
- the material and structure of the breathable support material are not particularly limited as long as the breathable support material is more breathable than the PTFE porous membrane of the present invention.
- the structure of the breathable support material may be, for example, felt, non-woven fabric, woven fabric, or mesh (mesh-like sheet).
- a breathable support made of a nonwoven fabric is preferred because of its strength, flexibility, and workability in the manufacturing process.
- at least some of the fibers constituting the nonwoven fabric have a so-called core-sheath structure. It may be a composite fiber.
- the melting point of the core component is higher than the melting point of the sheath component, it becomes easier to heat and press the breathable support material and the PTFE porous membrane in the production of the filter medium.
- the number of folding pitches can be increased when performing a bending force such as h.
- polyolefin polyethylene, polypropylene, etc.
- polyester polyamide (nylon, etc.)
- aromatic polyamide polyamide
- a composite material thereof may be used.
- fluorine-based resin such as PFA (tetrafluoroethylene Z perfluoroalkyl butyl ether copolymer), FEP (tetrafluoroethylene Z hexafluoropropylene copolymer), Alternatively, use a porous PTFE membrane.
- FIG. 1 shows an example of the filter unit of the present invention.
- a filter unit 1 shown in FIG. 1 is a filter unit that includes a filter medium 2 that collects particles contained in a gas to be filtered, and a support frame 3 that supports the filter medium 2. It is the filter medium of this invention.
- the filter unit 1 can achieve both high collection efficiency and low pressure loss.
- the filter media 2 is pleated, and the filter media 2 may be pleated!
- the shape of the support frame 3 may be arbitrarily set by using a general material for the filter unit.
- the support method of the filter medium 2 in the support frame 3 is the same as that of a general filter unit.
- the mean flow pore size of the porous membrane sample was defined as the mean flow pore size measured with a porous material palm porometer on the porous membrane sample.
- the thickness of the porous membrane sample was determined using a SM-1201 type dial gauge manufactured by Teclock. More specifically, the thickness of the laminated body obtained by laminating 12 porous membrane samples was measured with the above dial gauge, and the value obtained by dividing the measured value by the number of laminated samples 12 was the thickness of the porous membrane sample. Say it.
- the pressure loss of the porous membrane sample is measured by placing the sample in a circular holder with an effective ventilation area of 100 cm 2 and creating a pressure difference on both sides of the set sample to allow gas to pass through. (Pressure permeation: 31.8 LZmin), and the pressure loss when the flow velocity of the permeating gas was 5.3 cmZsec was measured by a pressure gauge (manometer).
- PTFE fine powder (Asahi 'ICI Fluoropolymers, Fullon CD-123) 100 parts by weight and liquid paraffin 20 parts by weight as liquid lubricant are uniformly mixed, PTFE fine powder and liquid lubricant A PTFE paste that is a mixture of Next, the formed PTFE paste was extruded into a rod shape at a pressure of 2 MPa (20 kgZcm 2 ), and further rolled with a pair of metal rolls to form a strip-shaped PTFE sheet (thickness 0.2 mm). . Next, liquid paraffin was removed from the formed PTFE sheet by an extraction method using trichlene, and the removed PTFE sheet was wound around a tubular core in a roll shape.
- the PTFE sheet thus formed is uniaxially stretched in the longitudinal direction while continuously supplying the core force, and then uniaxially stretched in the width direction, and further, if necessary.
- Heat treatment was performed to prepare each PTFE porous membrane sample (Examples 1 to 6, Comparative Examples 1 to 4). It was. The uniaxial stretching in the longitudinal direction and the width direction, and the heat treatment were performed inside a heating furnace maintained at each temperature shown in Table 1 below. At this time, the PTFE sheet was sufficiently stretched or heat-treated in a state where it reached each of the above temperatures, so that sufficient time was allowed for the PTFE sheet to be positioned in the calothermal furnace.
- Table 1 below shows the stretching conditions in each porous membrane sample, the presence or absence of heat treatment, and the conditions.
- the needle penetration strength was higher than in Comparative Examples 1, 2, and 4, and a PTFE porous membrane excellent in strength could be formed.
- the needle penetration strength is greatly increased 400Pa and at greater Natsuta force pressure loss thickness 50 m compared to 6NZmm 2 the real ⁇ 1-6.
- Example 1 Apart from the evaluation of the above characteristics, the structures of the porous membrane samples of Example 1 and Comparative Example 1 were evaluated by a scanning electron microscope (SEM).
- SEM scanning electron microscope
- FIG. 2 The SEM image of Example 1 is shown in FIG. 2
- Comparative Example 1 is a sample obtained by performing stretching at a temperature lower than the melting point of PTFE in the longitudinal direction and the width direction of the strip-shaped PTFE sheet, and then performing heat treatment at a temperature higher than the melting point of PTFE.
- Example 1 there are many clear nodes in which the degree of fibril miniaturization is smaller than that in Comparative Example 1, and the area of the nodes exceeds 1 m 2. Had.
- a PTFE porous membrane having both a high collection efficiency and a low pressure loss while having a larger average pore diameter and a thicker film than conventional PTFE porous membranes.
- a manufacturing method can be provided.
- the PTFE porous membrane obtained by the production method of the present invention is suitable for use as a filter medium and a filter unit for collecting particles contained in the gas to be filtered.
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Materials Engineering (AREA)
- Analytical Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
- Filtering Materials (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
Abstract
Description
Claims
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR1020087026175A KR101353726B1 (ko) | 2006-03-28 | 2007-03-23 | 폴리테트라플루오로에틸렌 다공질막의 제조 방법과 필터 여과재 및 필터 유닛 |
US12/225,023 US7846238B2 (en) | 2006-03-28 | 2007-03-23 | Method of manufacturing porous polytetrafluoroethylene membrane, filter medium, and filter unit |
AT07739534T ATE523551T1 (de) | 2006-03-28 | 2007-03-23 | Verfahren zur herstellung einer porösen polytetrafluorethylen-membran, filtermedium und filtereinheit |
EP20070739534 EP2000499B1 (en) | 2006-03-28 | 2007-03-23 | Process for production of polytetrafluoroethylene porous membrane, filter medium and filter unit |
CN2007800118285A CN101415756B (zh) | 2006-03-28 | 2007-03-23 | 聚四氟乙烯多孔膜的制造方法、过滤器滤材及过滤器单元 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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JP2006-088175 | 2006-03-28 | ||
JP2006088175A JP4963185B2 (ja) | 2006-03-28 | 2006-03-28 | ポリテトラフルオロエチレン多孔質膜の製造方法とフィルター濾材ならびにフィルターユニット |
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WO2007119508A1 true WO2007119508A1 (ja) | 2007-10-25 |
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PCT/JP2007/056093 WO2007119508A1 (ja) | 2006-03-28 | 2007-03-23 | ポリテトラフルオロエチレン多孔質膜の製造方法とフィルター濾材ならびにフィルターユニット |
Country Status (7)
Country | Link |
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US (1) | US7846238B2 (ja) |
EP (1) | EP2000499B1 (ja) |
JP (1) | JP4963185B2 (ja) |
KR (1) | KR101353726B1 (ja) |
CN (1) | CN101415756B (ja) |
AT (1) | ATE523551T1 (ja) |
WO (1) | WO2007119508A1 (ja) |
Cited By (1)
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US8105411B2 (en) | 2008-08-28 | 2012-01-31 | Illinois Tool Works Inc. | Fluid filter system and method |
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EP1750493B1 (en) * | 2005-07-14 | 2011-03-16 | W.L.Gore & Associates Gmbh | Fan cooling unit for cooling electronic components |
JP5658860B2 (ja) * | 2008-05-12 | 2015-01-28 | 日東電工株式会社 | ポリテトラフルオロエチレン多孔質膜およびその製造方法ならびに濾材 |
JP2011105895A (ja) * | 2009-11-20 | 2011-06-02 | Nitto Denko Corp | ポリテトラフルオロエチレン多孔質膜の製造方法とフィルタ濾材ならびに集塵機用のフィルタユニット |
US8092768B2 (en) | 2010-02-11 | 2012-01-10 | Energy & Environmental Research Center Foundation | Advanced particulate matter control apparatus and methods |
JP5012990B2 (ja) | 2010-06-17 | 2012-08-29 | ダイキン工業株式会社 | 多孔膜を備える濾材、その製造方法、フィルタパック、ならびにフィルタユニット |
JP2013022547A (ja) * | 2011-07-25 | 2013-02-04 | Nitto Denko Corp | フィルタユニットおよびそれを備えた掃除機 |
US20140231341A1 (en) * | 2013-02-15 | 2014-08-21 | Pall Corporation | Ptfe membrane |
JP6411826B2 (ja) * | 2013-09-12 | 2018-10-24 | 日東電工株式会社 | 充填材含有フッ素樹脂シートの製造方法 |
KR102527125B1 (ko) * | 2015-05-07 | 2023-04-27 | 닛토덴코 가부시키가이샤 | 필터 여과재 및 필터 유닛 |
JP6816938B2 (ja) * | 2015-07-27 | 2021-01-20 | 日東電工株式会社 | 撥油性が付与された通気フィルタ |
CN110088179B (zh) * | 2016-12-19 | 2022-08-05 | 日东电工株式会社 | 聚四氟乙烯多孔膜和使用该聚四氟乙烯多孔膜的防水透气膜以及防水透气构件 |
CN108807786B (zh) * | 2017-05-04 | 2020-05-15 | 宁波昌祺微滤膜科技有限公司 | 一种用于电池隔离的增强膜及其制备方法 |
KR102390248B1 (ko) * | 2017-09-22 | 2022-04-22 | 닛토덴코 가부시키가이샤 | 에어 필터 여과재, 필터 플리트 팩 및 에어 필터 유닛 |
KR102160201B1 (ko) * | 2017-10-26 | 2020-09-25 | 주식회사 엘지화학 | 불소계 수지 다공성 막 및 그 제조방법 |
EP3812026A4 (en) * | 2018-06-01 | 2022-03-16 | Nitto Denko Corporation | FILTERING MEDIUM AND FILTER UNIT EQUIPPED THEREOF |
US20220040614A1 (en) * | 2018-09-28 | 2022-02-10 | Daikin Industries, Ltd. | Air filter medium, filter pack, air filter unit, and method for producing the same |
WO2021112197A1 (ja) * | 2019-12-05 | 2021-06-10 | 日東電工株式会社 | ポリテトラフルオロエチレン延伸多孔質膜とこれを用いた通気濾材及びフィルター部材 |
US20230019449A1 (en) * | 2019-12-05 | 2023-01-19 | Nitto Denko Corporation | Stretched porous polytetrafluoroethylene membrane, air-permeable medium using the same, and filter member using the same |
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2006
- 2006-03-28 JP JP2006088175A patent/JP4963185B2/ja active Active
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2007
- 2007-03-23 US US12/225,023 patent/US7846238B2/en not_active Expired - Fee Related
- 2007-03-23 WO PCT/JP2007/056093 patent/WO2007119508A1/ja active Application Filing
- 2007-03-23 CN CN2007800118285A patent/CN101415756B/zh active Active
- 2007-03-23 KR KR1020087026175A patent/KR101353726B1/ko not_active IP Right Cessation
- 2007-03-23 AT AT07739534T patent/ATE523551T1/de not_active IP Right Cessation
- 2007-03-23 EP EP20070739534 patent/EP2000499B1/en not_active Not-in-force
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Also Published As
Publication number | Publication date |
---|---|
JP2007260547A (ja) | 2007-10-11 |
EP2000499A2 (en) | 2008-12-10 |
KR20090017488A (ko) | 2009-02-18 |
ATE523551T1 (de) | 2011-09-15 |
EP2000499A4 (en) | 2010-04-14 |
KR101353726B1 (ko) | 2014-01-20 |
CN101415756B (zh) | 2011-08-03 |
JP4963185B2 (ja) | 2012-06-27 |
US20090071339A1 (en) | 2009-03-19 |
CN101415756A (zh) | 2009-04-22 |
EP2000499B1 (en) | 2011-09-07 |
US7846238B2 (en) | 2010-12-07 |
EP2000499A9 (en) | 2009-03-25 |
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