WO2021224115A1 - Filtre à base d'un matériau composite non tissé - Google Patents

Filtre à base d'un matériau composite non tissé Download PDF

Info

Publication number
WO2021224115A1
WO2021224115A1 PCT/EP2021/061335 EP2021061335W WO2021224115A1 WO 2021224115 A1 WO2021224115 A1 WO 2021224115A1 EP 2021061335 W EP2021061335 W EP 2021061335W WO 2021224115 A1 WO2021224115 A1 WO 2021224115A1
Authority
WO
WIPO (PCT)
Prior art keywords
layer
polymer
range
nonwoven
filter
Prior art date
Application number
PCT/EP2021/061335
Other languages
German (de)
English (en)
Inventor
Juergen Ahlers
Original Assignee
Basf Se
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Basf Se filed Critical Basf Se
Publication of WO2021224115A1 publication Critical patent/WO2021224115A1/fr

Links

Classifications

    • 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
    • B01D39/1607—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being fibrous
    • B01D39/1623—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being fibrous of synthetic origin
    • A—HUMAN NECESSITIES
    • A41—WEARING APPAREL
    • A41D—OUTERWEAR; PROTECTIVE GARMENTS; ACCESSORIES
    • A41D13/00—Professional, industrial or sporting protective garments, e.g. surgeons' gowns or garments protecting against blows or punches
    • A41D13/05—Professional, industrial or sporting protective garments, e.g. surgeons' gowns or garments protecting against blows or punches protecting only a particular body part
    • A41D13/11—Protective face masks, e.g. for surgical use, or for use in foul atmospheres
    • A—HUMAN NECESSITIES
    • A62—LIFE-SAVING; FIRE-FIGHTING
    • A62B—DEVICES, APPARATUS OR METHODS FOR LIFE-SAVING
    • A62B23/00—Filters for breathing-protection purposes
    • A62B23/02—Filters for breathing-protection purposes for respirators
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
    • B01D2239/02—Types of fibres, filaments or particles, self-supporting or supported materials
    • B01D2239/025—Types of fibres, filaments or particles, self-supporting or supported materials comprising nanofibres
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
    • B01D2239/06—Filter cloth, e.g. knitted, woven non-woven; self-supported material
    • B01D2239/0604—Arrangement of the fibres in the filtering material
    • B01D2239/0622—Melt-blown
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
    • B01D2239/06—Filter cloth, e.g. knitted, woven non-woven; self-supported material
    • B01D2239/0604—Arrangement of the fibres in the filtering material
    • B01D2239/0631—Electro-spun
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
    • B01D2239/06—Filter cloth, e.g. knitted, woven non-woven; self-supported material
    • B01D2239/065—More than one layer present in the filtering material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
    • B01D2239/06—Filter cloth, e.g. knitted, woven non-woven; self-supported material
    • B01D2239/065—More than one layer present in the filtering material
    • B01D2239/0668—The layers being joined by heat or melt-bonding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
    • B01D2239/06—Filter cloth, e.g. knitted, woven non-woven; self-supported material
    • B01D2239/065—More than one layer present in the filtering material
    • B01D2239/0681—The layers being joined by gluing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
    • B01D2239/10—Filtering material manufacturing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
    • B01D2239/12—Special parameters characterising the filtering material
    • B01D2239/1216—Pore size
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
    • B01D2239/12—Special parameters characterising the filtering material
    • B01D2239/1233—Fibre diameter

Definitions

  • the present invention relates to a filter based on a composite of a fleece and a carrier layer (fleece composite).
  • Nonwovens have been described many times and are used for a wide variety of applications.
  • a particular challenge is to manufacture mechanically stable filters with suitable filter properties.
  • An air-permeable surface filter is described, for example, in DE 102018 100935 A1, WO2019 / 058292 or also US 2005/0235619.
  • US 2019/0160404 describes a flow composite based on polymers, including thermoplastic polyurethane, using an electrospinning process, whereby two polymers with different melting points are used for the finer-pored flow.
  • KR 2017120821 A also addresses how a polymer fleece is generated on a release paper by means of electrospinning, transferred to a first polyurethane base material and then connected to this and another polyurethane base material by the action of heat.
  • KR 2017120807 A a polymer fleece is applied to both sides of a polyurethane base material.
  • Electrospun nonwovens are interesting because they can also be used to produce narrow pore diameters. However, it is disadvantageous that these electrospun nonwovens alone do not offer sufficient strength to be used in filters.
  • the object of the present invention was therefore to provide a filter which can be easily manufactured and in which the pore diameter of the filter can be easily adjusted.
  • Another object of this invention is a method for producing the filter.
  • the invention further relates to a nonwoven composite obtained or obtainable according to this method and the use of such a nonwoven composite for the production of a filter.
  • a first embodiment of the invention is a filter containing a nonwoven composite, comprising i) a first layer, preferably a nonwoven layer, comprising strands, preferably fibers from a first polymer, preferably having meshes with a mesh size in the range from 5 mhi to 1 mm, ii ) a second non-woven layer, applied to the first non-woven layer, comprising fibers made of a second polymer, preferably having meshes with a mesh size of less than 100 mhi, preferably less than 50 mhi, preferably less than 20 mhi, the fibers of the second non-woven layer at least partially in direct contact with the fibers of the first layer, preferably the first fleece layer, and at least partially cover the mesh openings of the first layer, and the strands or fibers of the first layer with the fibers of the second fleece layer in the contact area at least partially are connected to each other.
  • the mesh size of the second nonwoven layer is 0.05 mhi to 20 mhi, more preferably in the range from 0.2 mhi to 10 mhi, and particularly preferably in the range 0.1 mhi to 5 mhi.
  • Mesh sizes of less than 100 mhi in the second fleece layer are particularly suitable for removing moisture droplets from media, preferably from gases, in particular from air.
  • Mesh sizes of less than 5 mhi are particularly suitable for removing microorganisms in aerosols from media. With a mesh size of less than 0.3 mhi, viruses can also be removed from media, for example.
  • Connected means that the strands of the first layer are intertwined, glued or welded with the fibers of the second nonwoven layer, preferably glued or welded, and particularly preferably welded.
  • a filter is understood to mean a device that can be introduced into a media flow in order to filter it.
  • Filtering means in particular unwanted components of the To prevent the medium from penetrating the filter with the fleece composite of the filter.
  • Preferred media that are filtered with the filter are gases or liquids.
  • the medium is air.
  • the filter has suitable devices and / or configurations that enable the filter to be fixed in the corresponding media flow in such a way that the filter performance primarily provided by the fleece composite is guaranteed.
  • a filter with the nonwoven composite has good mechanical properties, in particular high mechanical strength, has good filter properties and a good balance between specifically adjustable filtering capacity and high media permeability.
  • a “fleece” or a “fleece layer” means a non-woven fabric that consists entirely or to a substantial extent, ie preferably more than 90% by weight, more preferably more than 95% by weight, more preferably to more than 97% by weight, and particularly preferably to more than 99% by weight.
  • “Fiber” is preferably understood to mean a staple fiber that has emerged from an extrusion process or from an electrospinning process. Fibers are also known as filaments. Fibers preferably have a degree of slenderness, i.e. a ratio of fiber length in mm to fiber diameter in mm of at least 300.
  • Types of interconnection of the fibers in the fleece are entanglement, cohesion, adhesion, fusion, gluing or combinations of these types of interconnection. Fusion or gluing are preferred.
  • the fibers in the fleece are structured or randomly arranged, preferably randomly.
  • “Fleece composite” means a multilayer composite that contains one or more fleeces.
  • the fleece composite according to the invention comprises at least one first layer and at least one second fleece layer applied to the first layer.
  • the first layer, as well as the second fleece layer is designed in such a way that the medium to be filtered is permeable. That is to say, the layers of the filter have openings which are delimited by strands, preferably by threads.
  • the first layer is a flat structure with intersecting strands, preferably intersecting threads, more preferably selected from a grid, woven fabric, knitted fabric or fleece.
  • the first nonwoven layer is designed as a carrier layer.
  • This carrier layer is designed in such a way that it gives the second nonwoven layer sufficient mechanical strength to be able to filter the corresponding media flow.
  • These further support layers are again preferably flat structures with openings that are delimited by strands, preferably selected from lattice, fabric, Knitted fabrics or fleece. The person skilled in the art adapts the layer thickness and material properties and configuration of the carrier layer or carrier layers to the load conditions in the filter.
  • a “mesh” is an opening in the fabric, preferably the fleece, which is delimited by the strands of the fabric, in preferred embodiments by the fibers, the fabric, preferably the fleece.
  • the “mesh size” (w) is the greatest distance between two strands, in preferred embodiments two fibers, which delimit this opening in the fabric, preferably the fleece.
  • the mesh size is preferably determined with a microscope with a 90 ° view. To determine the mesh size, a total of 100 mesh sizes of openings in a layer are determined and the average is determined therefrom.
  • the mesh size of at least 10 openings located directly one behind the other on a straight line are determined by arbitrarily laid straight lines. The straight lines must be laid in such a way that different openings are always measured to determine the mesh size.
  • connection of the first layer and the second fleece layer is preferably based on cold welding.
  • the threads of the fleece layer preferably also those of the first layer, are loosened with a solvent.
  • the solvent is preferably introduced through the solvent-rich threads produced in the electrospinning process.
  • the threads softened by the solvent fuse or weld to one another and the Léemit tel is then removed or it evaporates.
  • the second nonwoven layer is applied directly to the first layer by means of electrospinning. Electrospinning is used here in such a way that cold welding takes place.
  • further nonwoven layers are applied, preferably by means of electrospinning, to the nonwoven composite, preferably to the side of the second nonwoven layer which faces away from the first nonwoven layer.
  • the first layer and the second nonwoven layer are produced independently of one another and then connected to one another before given to cold welding.
  • Cold welding is preferably carried out at temperatures in the region of room temperature (15 to 30 ° C).
  • Cold welding is also carried out at pressures in the range of normal pressure (approx. 1013 mbar), preferably in a pressure range from 0.6 bar to 1.4 bar, more preferably in the range from 0.8 bar to 1.2 bar, particularly preferably in a range from 0.9 bar to 1.1 bar.
  • thermoplastic polymers of the two Fleece heated to the point where it can be welded. Since the fleece can only be melted to just below the melting temperature in order not to lose its shape, pressure usually also has to be applied, for example via rollers, in order to connect the two fleeces with one another.
  • the electrospinning process according to the invention is a significantly simpler process since it comprises fewer process steps. This also reduces the risk of destroying the fleece, in particular that with the smaller mesh size. With fewer process steps, the introduction of contamination is naturally also lower, which is fundamentally an advantage for filters.
  • the second layer is applied or can be applied directly to the first nonwoven layer by means of electrospinning.
  • further fleece layers are applied to the second fleece layer, preferably by means of electrospinning.
  • Laying more than two fleece layers on top of one another in the fleece composite has the advantage that particles of different sizes are retained in different fleece layers.
  • the different fleece layers can be designed for the corresponding particle size.
  • Electroninning is understood to mean the production of very thin fibers with a fiber diameter in the range from 0.01 pm to 0.5 pm, more preferably in the range from 0.05 pm to 0.5 pm.
  • These fibers are preferably formed from polymer solutions, polymer melts or polymer reactive systems, preferably from polymer melts or solutions, particularly preferably from polymer solutions.
  • the fleece is more preferably produced by applying an electrical field, preferably at voltages in the range from 5 kV to 80 kV.
  • the polymer solution is preferably dosed at at least one electrode and drawn off from the electrode by the electric field and drawn onto a second electrode on which the fleece is formed.
  • the metering is preferably carried out by means of wires which are arranged on a cylinder around the cylinder axis and which are regularly immersed in the polymer solution, also known as the spinning solution, by a circular movement of the cylinder around this axis, which preferably runs parallel to the surface of the polymer solution, covering them with the solution. Since a voltage between 5 kV and 80 kV is applied to the spinning solution storage container in relation to the counter electrode on which the fleece is formed, this leads to the solution being sprayed off the wires. On the way to the counter electrode, at least some of the solvent contained in the spinning solution evaporates, and fibers that are still moist from the solvent are deposited as a fleece on the counter electrode at high speed.
  • the counter electrode is preferably designed to be flat.
  • the first layer is preferably located on the counter electrode or is the counter electrode, so that the fleece resulting from the electrospinning process is created directly on the first layer. Further layers can be applied in the same way.
  • the first layer is moved in such a way that the second nonwoven layer is continuously formed thereon, preferably also further layers
  • Organic solvents with a log K ow in the range from -1.5 to +1 are preferably used as solvents, preferably selected from the group of dimethylformamide (DMF, log KOW -0.85), tetrahydrofuran (THF, log Kow 0, 46), dimethyl sulfoxide (DMSO, log Kow -1, 35), N-methyl-2-pyrrolidone (NMP, log K ow-0.46), ethyl acetate (ethyl acetate, log K owO, 73), methyl ethyl ketone (MEK, log K ow 0.29), ethyl ethyl ketone (EEK, log K ow 0.99) and mixtures of two or more of these organic solvents, more preferably selected from the group of DMF, THF and mixtures of DMF and THF .
  • DMF dimethylformamide
  • THF tetrahydrofuran
  • DMSO dimethyl sulfoxide
  • NMP
  • the electrospinning is preferably carried out at temperatures in the range from 15 ° C to 30 ° C (room temperature). More preferably, the electr spinning takes place at pressures in the range of normal pressure (1013 mbar) or in a pressure range from 0.6 bar to 1.4 bar, preferably in the range from 0.8 to 1.2 bar, particularly preferably in one range 0.9 bar to 1.1 bar.
  • the first layer comprises strands, preferably fibers, made of a first polymer and the second nonwoven layer, optionally further layers, include fibers made of a second polymer.
  • the selected polymers are preferably thermoplastic.
  • the polymers are preferably selected so that they are compatible with one another. “Compatible with one another” means that the first and the second polymer are compatible in terms of chemical compatibility, with the adhesion of the second nonwoven layer, in particular produced by electrospinning, to the first layer, preferably the first nonwoven layer. is essential. The same applies in the same way, if necessary, to further layers.
  • the solvent-containing nano-web of the second non-woven layer (ii) adheres to the carrier layer by cold welding, ie a bond is formed between the first layer, preferably the first non-woven layer and the second non-woven layer.
  • the layers with suitable adhesive fabrics connected to each other. The connection of the layers with compatible polymers results, among other things, in better permeability but often also in higher strength and durability. The same applies to the other fleece layers.
  • Preferred combinations of compatible polymers in the various layers, in particular also in the first layer and in the second non-woven layer, are selected from the group consisting of thermoplastic polyurethane (TPU1) / thermoplastic polyurethane (TPU2), polyester / thermoplastic polyurethane, polyamide / thermoplastic polyurethane, Cellulose / thermoplastic polyurethane, polyester 1 / polyester 2, polyester / polyamide, cellulose / polyamide, cellulose / polyester, polyethersulphone / polyethersulphone, polyethersulphone / polysulphone, polysulphone / polysulphone, polyester / polyethersulphone, polyamide / polyethersulphone.
  • cellulose also includes paper.
  • Polyamide is preferably understood to mean polyamide 6, polyamide 6.6, polyamide 6 / 6.6 copolymer, or polyamide 6.6 / 36, as well as their mixtures or blends.
  • this blend is also compatible with the other polymer or a blend or mixture of this second polymer if the respective polymers in the blend independently of one another - at least 50% by weight, further preferably at least 60% by weight, further preferably at least 70% by weight, further preferably at least 80% by weight, further preferably at least 90% by weight, further preferably at least 95% by weight, further preferably at least 99% by weight are.
  • Thermoplastic polyurethane, polyamide or polyethersulfone is preferably contained in the second layer, if necessary also in the further layers.
  • the first layer preferably contains polyester, thermoplastic polyurethane, polyamide or cellulose.
  • the at least two layers of the filter consist of the same polymer. If there are further layers of non-woven fabric, these also preferably consist of the same polymer. Among other things, this has the advantage that such fleece composites can be produced according to type and can therefore be more easily processed and recycled.
  • TPU Thermoplastic Polyurethane
  • the at least two layers, possibly also further layers, of the nonwoven composite are preferably each made independently of one another from thermoplastic polyurethane (TPU),
  • first thermoplastic polymer and the second thermoplastic polymer are both a mutually compatible thermoplastic polyurethane (TPU), the TPU of the various nonwoven layers preferably containing the same or different structural components on the one hand.
  • the fleece layers particularly preferably have the same structural components. Construction components are the diisocyanate, the difunctional substance reactive with the isocyanate group, preferably a diol, which is also called a soft phase, and optionally a chain extender.
  • TPU Compatible thermoplastic polyurethane
  • TPU means that the soft phase of a TPU is at least 50% by weight, preferably at least 60% by weight, more preferably at least 65% by weight, more preferably at least 70% by weight preferably at least 80% by weight, more preferably at least 90% by weight, more preferably at least 95% by weight, components identical to the soft phase of the other thermoplastic polyurethane (TPU).
  • thermoplastic polyurethane of the first and the second layer is identical.
  • Identical means that the polyol consists of the same monomer units, but the isocyanate and the chain extender are also identical.
  • TPU Thermoplastic polyurethane
  • C1 Thermoplastic polyurethane
  • D1 diol
  • thermoplastic polyurethane TPU
  • the first thermoplastic polymer is a TPU1
  • the second thermoplastic polymer is a TPU2
  • both TPU1 and also TPU2 on the named components more preferably on the named components in the named quantities.
  • the molar ratio of the at least one diol (D1) to the at least one isocyanate (11) is usually in the range from 1: 3 to 3: 1.
  • the molar ratio of the at least one diol (D1) to at least one isocyanate (11) is preferably in the range from 1: 1 to 1: 2, preferably in the range from 1: 1.2 to 1: 1.8, more preferably in Range from 1: 1.4 to 1: 1.6.
  • the at least one compound (C1) can be any compound with at least two isocyanate-reactive groups.
  • the isocyanate-reactive groups are preferably hydroxyl or amino groups.
  • the at least one compound (C1) can be added to modify the properties of the TPU. Any connection can be used as long as it is suitable for producing a thermoplastic polyurethane with the mixture of the at least one diol (D1) and the at least one isocyanate (11).
  • the at least one compound (C1) can be a polyol, but also a polymer with at least two hydroxyl groups or at least two amino groups other than a polyol, for example a hydrophobic polymer or oligomer comprising silicon.
  • the at least one compound (C1) having at least two isocyanate-reactive groups is a polyol.
  • Polyols are known to the person skilled in the art and are described, for example, in "Kunststoffhandbuch, 7, Polyurethane", Carl Hanser Verlag, 3rd edition 1993, section 3.1.
  • Polyols which are preferably used are polymeric compounds which have hydrogen atoms which are reactive towards isocyanates. All suitable polyols can be used here, for example polyether polyols or polyester polyols or mixtures of two or more thereof, preferably polyether diols or polyester diols, or mixtures of two or more thereof.
  • Preferred polyether diols are polyether diols based on the monomers tetrahydrofuran (THF), ethylene oxide (EO) or propylene oxide (PO) or mixtures thereof: Such mixtures are copolymers, preferably block copolymers.
  • Other preferred polyols are polyester diols, polyester diols also including polycarbonate diols.
  • at least one polyether diol is used as at least one compound (C1), preferably selected from the group of polytetrahydrofuran (PTHF), polyethylene glycol (PEG), polypropylene glycol and mixtures thereof.
  • PTHF and PEG are particularly preferred, each of these components in turn being a single polyether diol or a mixture of two or more of the respective polyether diols.
  • PTHF preferably has a number average molecular weight Mn in the range from 500 to 3000 g / mol, preferably in the range from 1000 to 2000 g / mol
  • PEG likewise preferably has a number average molecular weight Mn in the range from 500 to 3000 g / mol, preferably in the range from 1000 to 2000 g / mol.
  • Thermoplastic polyurethanes (TPU) based on polyetherols are preferred because they are water-repellent. Droplets of hydrophilic liquids, e.g. water, are retained on the surface of the filter when the gas flows through. Filters based on this TPU also have the advantage that they have a higher hydrolysis stability and also have fewer sources than TPU based on polyester polyols,
  • the at least one isocyanate (11) is preferably at least one polyisocyanate (11).
  • Aliphatic, cycloaliphatic, araliphatic and / or aromatic polyisocyanates, preferably diisocyanates, can be used as the polyisocyanate (11).
  • aromatic diisocyanates should be mentioned by way of example: 2,4-toluene diisocyanate, mixtures of 2,4- and 2,6-toluene diisocyanate, 4,4'-, 2,4'- and / or 2,2 '-Diphenylmethane diisocyanate (MDI), mixtures of 2,4'- and 4,4'-diphenylmethane diisocyanate, urethane-modified liquid 4,4'- and / or 2,4-diphenylmethane diisocyanate, 4,4'-diisocyanatodiphenylethane, mixtures of monomers Methanediphenyl diisocyanates and other highly polycyclic homologues of methanediphenyl diisocyanate (polymeric MDI), 1,2- and 1,5-naphthylene diisocyanate.
  • MDI 2,4-toluene diisocyanate
  • Aliphatic diisocyanates are customary aliphatic and / or cycloaliphatic diisocyanates, for example tri-, tetra-, penta-, hexa-, hepta- and / or octamethylene diisocyanate, 2-methylpentamethylene-1,5-diisocyanate, 2-ethylbutylene-1,4 -diisocyanate, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 1,4- and / or 1,3-bis (isocyanatomethyl) cyclohexane (HXDI),
  • the at least one isocyanate (11) is a diisocyanate selected from the group consisting of diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI), and hexamethylene diisocyanate (HDI), dicyclohexylmethane-4,4'-diisocyanate (H12MDI), and preferably comprises at least MDI.
  • MDI diphenylmethane diisocyanate
  • TDI toluene diisocyanate
  • HDI hexamethylene diisocyanate
  • H12MDI dicyclohexylmethane-4,4'-diisocyanate
  • the polyisocyanate can be used pure or in the form of a composition, for example as an isocyanate prepolymer. Furthermore, a mixture comprising polyisocyanate and at least one solvent can be used, suitable solvents being known to the person skilled in the art.
  • Polyisocyanate prepolymers can be obtained by reacting the above-described polyisocyanates in excess, for example at temperatures in the range from 30 to 100 ° C., preferably at more than 80 ° C., with polyols to preserve the prepolymer.
  • polyisocyanates and the compound C1 are preferably used. Preference is given to polyethers, preferably produced from the monomers tetrahydrofuran, ethylene oxide and / or propylene oxide.
  • any diol can be used as the diol (D1), which functions as a chain extender (K).
  • the diol (D1) is preferably selected from the group consisting of aliphatic, araliphatic, aromatic and / or cycloaliphatic compounds with a molecular weight in the range from 0.05 kg / mol to 0.499 kg / mol, preferably difunctional compounds, for example diamines and / or alkanediols with 2 to 10 carbon atoms in the alkylene part, di-, tri-, tetra-, penta-, hexa-, hepta-, octa-, nona- and / or decaalkylene glycols with 3 to 8 carbon atoms, in particular ethylene 1,2-glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, and preferably corresponding oligo- and / or polyprop
  • the diols preferably only have primary hydroxyl groups.
  • 1,4-butanediol, 1,3-propanediol or mixtures of 1,4-butanediol and 1,3-propanediol are preferably used as diol (D1).
  • chain extenders are ethanediol, butanediol, hexanediol and monoethyl glycol, more preferably at least 1,4-butanediol or monoethylene glycol.
  • the ratio of organic polyisocyanates to polyols and chain extenders is preferably chosen so that the isocyanate prepolymer has an NCO content in the range from 2 to 30% by weight, more preferably in the range from 6 to 28% by weight, more preferably in the range from 10 to 24% by weight.
  • auxiliaries are, for example, surface-active substances, fillers, flame retardants, nucleating agents, oxidation stabilizers, lubricants and mold release aids, dyes, pigments and, optionally, stabilizers, for example to protect against hydrolysis, light, heat or discoloration, inorganic and / or organic Fillers, reinforcing agents and plasticizers.
  • Usual auxiliaries and additives can be found in the “Plastics Handbook” (“Plastics Handbook”; 7, “Polyurethane”, Carl Hanser Verlag, 1st edition 1966, pages 103-113).
  • the strands preferably those of the first layer, preferably the first nonwoven layer, and the fibers of the second nonwoven layer, each independently of one another, have a diameter in the range from 0.01 ⁇ m to 100 ⁇ m, preferably the strands, more preferably the fibers of the first nonwoven layer (i) have a diameter in the range from 1 ⁇ m to 50 ⁇ m, preferably in the range from 10 ⁇ m to 30 ⁇ m; and the fibers of the second nonwoven layer (ii) have a diameter in the range between 0.01 pm and 0.5 pm, preferably in the range between 0.05 pm and 0.5 pm, more preferably in the range between 0.08 pm and 0 , 2 pm.
  • the second fleece layer (ii) has a mesh size in the range from 0.05 ⁇ m to 20 ⁇ m, in the range from 0.2 ⁇ m to 15 ⁇ m, or in the range from 0.3 ⁇ m to 1 ⁇ m , on. These areas are particularly preferred when the filter is used in a respirator or is a respirator.
  • the mesh size of the fleece layer (i) is preferably 2 to 100 times larger than the mesh size of the fleece layer (ii), more preferably by a factor of 2 to 50, more preferably by a factor of 2 to 20, more preferably by a factor of 2 to 10, particularly preferably around the Factor 2 to 5.
  • the fleece layer (ii) is supported particularly well by the fleece layer (i).
  • this has a water tightness (LEP) of more than 0.5 bar.
  • LEP water tightness
  • the elongation at break of the nonwoven composite is preferably more than 200%, more preferably more than 250% measured according to DIN ISO 34-1, B: 2016.
  • WCD water vapor permeability
  • Humidity at least 1000g / m 2 * d.
  • a highly hydrophobic TPU is used for at least one layer.
  • Such filters are particularly suitable for use in respiratory masks or as such, since they can keep droplets away and, among other things, lead to longer filter lifetimes.
  • the hydrophobization of the TPU is achieved by preferably using polyethers in the soft phase, as described above.
  • silicones are incorporated into the TPU. Silicones are preferably embedded in the polyol or coupled to the polyol, preferably chemically coupled. Examples of hydrophobized thermoplastic polyurethanes can be found, for example, in US 2008/015328 or WO 2019/016313, which are part of this application.
  • both polyethers are used for waterproofing and silicones are incorporated into the TPU.
  • the filters of this invention are preferably part of a filter system.
  • Filter system means that further filter elements are part of such a filter system.
  • Further filters are preferably placed upstream of the filter according to the invention. These filters can filter out larger constituent parts of the medium or prevent other constituents that are not filtered by the filter according to the invention or that could destroy it.
  • the closer-meshed fleece is aligned in the direction of the media flow to be filtered, so that the wider-meshed layer only serves to support the finer fleece.
  • the wider-meshed first layer is placed in front of the narrower-meshed second nonwoven layer in the media flow to be filtered, so that the first layer itself acts as a filter for coarser constituents.
  • the invention further relates to a method for producing a filter containing a nonwoven composite, preferably according to one of the embodiments described above or a preferred embodiment, comprising the following steps: a) providing at least one first layer, preferably a nonwoven layer, comprising strands, preferably fibers a first polymer and having meshes with a mesh size in the range from 5 ⁇ m to 1 mm, b) providing a polymer solution, or a polymer melt or a polymer reactive system, preferably a polymer solution, comprising a second polymer or its structural components, the second polymer preferably being the first polymer of the first layer is compatible; c) Applying a second nonwoven layer on the first layer, preferably the first nonwoven layer, by means of electrospinning, wherein preferably the second nonwoven layer (ii) fibers from the second polymer having meshes with a mesh size of less than 100 ⁇ m, preferably less than 50 ⁇ m , more preferably less than 20 pm, more preferably less
  • At least one further nonwoven layer is applied to the second nonwoven layer.
  • this nonwoven layer with respect to the nonwoven layer with which it is in contact, the following applies accordingly to the first layer and the second nonwoven layer.
  • the electrospinning is described above in detail for the nonwoven composite, the preferred details mentioned there also apply to the manufacturing process described here; it takes place preferably at temperatures in the range of room temperature (15 to 30 ° C.) and at normal pressure, or preferably in a pressure range from 0.8 to 1.2 bar, more preferably at 0.9 to 1.1 bar.
  • a polymer reactive system means a multi-component, in particular two-component system, the components of which react to form the polymer during electrospinning.
  • the first polymer of the first layer provided according to (a) and the second polymer of the polymer solution provided according to (b) are independently selected from the group consisting of polyurethane, polyester, polyetherester, polyesterester, polyamide , Polyetheramide, po- lybutadiene styrene and ethylene vinyl acetate, polylactide, polyoxymethylene, polyethersulfone, polyetherimide, polysulfone, or mixtures or blends thereof, the first polymer and the second polymer preferably being selected so that they are compatible with each other, with further preferred the first polymer and the second Polymer, each independently of the other thermoplastic polymers, are preferably thermoplastic polyurethane (TPU).
  • TPU thermoplastic polyurethane
  • the first TPU (TPU1) is identical or different, preferably identical, to the second TPU (TPU2).
  • TPU the same applies as stated above for the nonwoven composite. If further layers are contained in the filter, the statements made for the first layer and the second non-woven layer preferably apply accordingly to these layers.
  • a polymer solution is provided in a preferred embodiment.
  • This polymer solution preferably comprises an organic solvent with a log K ow in the range from -1.5 to +1, more preferably selected from the group of dimethylformamide (DMF, log K ow -0.85), tetrahydrofuran (THF, log Kow 0.46), dimethyl sulfoxide (DMSO, log Kow -1.35), N-methyl-2-pyrrolidone (NMP, log K ow -0.46), ethyl acetate (ethyl acetate, log K owO, 73), methyl ethyl ketone ( MEK, log K ow 0.29), ethyl ethyl ketone (EEK, log K owO, 99) and mixtures of two or more of these organic solvents, more preferably selected from the group of DMF, THF and mixtures of DMF and THF.
  • DMF dimethylformamide
  • THF tetrahydro
  • the polymer solution provided according to process step (b) has a polymer concentration in the range of 3-50% by weight, preferably in the range of 5-30% by weight, more preferably in the range of 10-20% by weight, in particular if the second polymer is a TPU, in each case based on the total weight of the polymer solution of 100% by weight.
  • the strands, preferably the fibers of the first layer provided according to (a), preferably the first nonwoven layer have a diameter in the range from 0.01 ⁇ m to 100 ⁇ m, preferably in the range from 1 ⁇ m pm to 50 pm, more preferably in the range from 10 pm to 30 pm.
  • the fibers of the second nonwoven layer applied according to (c) have a diameter in the range from 0.01 ⁇ m to 2 ⁇ m, preferably in the range from 0.01 ⁇ m to 0.5 ⁇ m, more preferably in the range from 0.05 pm to 0.5 pm, more preferably in the range from 0.08 pm to 0.2 pm.
  • the invention also relates to a filter containing a nonwoven composite, obtained or obtained Lich by the method described above.
  • the invention further relates to the use of the filter containing a nonwoven composite as described above or a filter obtained or obtainable by the method described above as a media filter.
  • Preferred media are liquids or gases.
  • a particularly preferred liquid is water, and a preferred gas is air.
  • the filter is used to filter air in a breathing mask or can be used directly as a breathing mask thanks to a suitable shape and suitable fastening means.
  • Be preferred fastening means are cords that are fixed or elastic.
  • the filter is preferably shaped so that it covers the mouth and nose area of a living being.
  • Preferred living beings are people, farm animals, or pets.
  • the filter according to this invention can be optimally adjusted to constituents that are preferably to be filtered, preferably macromolecules, particles, aerosols, bacteria, or viruses, by suitable selection of the mesh sizes.
  • the filter systems can be used for very different filter systems through a suitable combination of the carrier materials, possibly applied to further, even more solid carrier materials, which are preferably placed on even wider meshed plastic or metal grids.
  • the ratio of breathing air permeability and filtration performance against e.g. aerosols, particles, viruses or bacteria can be set so that a very high permeability of breathing air can be set with a very high filter performance, since the thin nanofibers have a very high Allow the filter to pass through.
  • the use of exhalation valves in such a mask can be dispensed with, which in turn can reduce the leakage rate of the masks.
  • the wearing comfort is significantly increased compared to known constructions.
  • Mn is the number average molecular weight
  • Water vapor permeability DIN 53122 at 38 ° C and 90% humidity
  • the water vapor permeability (WDD) was determined using a cup method at 38 ° C. and 90% relative humidity in accordance with DIN 53122. High WDD values were desired and allowed high flow rates of the water vapor.
  • the liquid entry pressure (LEP) of the fleece composite was determined in accordance with DIN EN 20811 using a pressure line with a diameter of 60 mm with ultrapure water (salt-free water, filtered through a Millipore UF system) up to 4.0 bar (40,000 mm water column).
  • the liquid entry pressure LEP is defined as the pressure at which the liquid water begins to permeate the fleece composite.
  • a high LEP allows the fleece composite to withstand a high water column (liquid).
  • TPU thermoplastic polyurethanes
  • the chain extender was added to the polyols while stirring. After the solution had been heated to 80 ° C., the isocyanate and, if applicable, the additives listed in the recipes were added and the mixture was stirred until the solution was homogeneous. The reaction mixture heated and was then poured onto a heated, Teflon coated table. The casting rind was tempered at 80 ° C. for 15 hours. The material produced in this way was comminuted in a mill to give free-flowing granules, dried again and filled into aluminum-coated PE bags for further use.
  • thermoplastic polyurethane TPUs 1 to 6 shown in Tab. 3 were produced from the starting materials in accordance with the general procedure from 3.
  • composition of TPUs 1 to 6 Determination of the mechanical properties of the TPUs
  • Spunbonded nonwovens with a weight per unit area of 50 and 90 g / m 3 were produced from TPU3 and TPU6 on a meltblown pilot plant.
  • the respective TPU was melted in a twin-screw extruder, continuously conveyed into the spinning head by means of a melt pump and deposited on a conveyor belt running underneath that was covered with a separating fleece made of polypropylene.
  • the separating fleece only had the function of a separator to prevent the TPU fleece from sticking to the base and to ensure that the TPU fleeces produced could be rolled up and unrolled easily.
  • the TPU fibers within the fleece produced were firmly bonded to one another welds and cannot be separated from each other. Table 5
  • THF tetrahydrofuran
  • 100 g of the respective TPU and 800 ml of THF were placed in a 1500 ml roll glass.
  • the roller glass was continuously moved on a roller system for 10 hours until all of the TPU had dissolved.
  • the TPU solution was then drawn through a 20 ⁇ m filter and packed in a wide-necked glass with a THF-tight lid.
  • the polymer solutions obtained from 7.1 were spun in a laboratory electrospinning system to nano-TPU fibers directly onto the TPU carrier nonwovens (ie onto the first nonwoven layer (i)) at room temperature (25 ° C) and at normal pressure (1013 mbar) .
  • a laboratory electrospinning system with rotating electrode according to US 2010/0028553 A1 was used for the spinning tests.
  • the rotating electrode had wires arranged on a rotating cylinder (wire electrode).
  • the solutions were spun at 80 kV.
  • the carrier webs from 6th i.e.
  • the respective first web layer (i)) were placed on the spinning bed of the laboratory electrospinning system and continuously moved over it by means of a roller device, linear speed in the range of 0.13-1.5 m / minute.
  • the electrospinning head moved continuously horizontally over the carrier fleece.
  • the electrospun fibers of the electrospun fleece (ie the respective second fleece layer (ii)) were, due to the chemically identical materials and the solvent still present, firmly cold-welded to the TPU carrier fleece, as can be seen from electron microscope images.
  • the mean diameter of the electrospun fibers determined from scanning electron recordings was approx. 0.1 ⁇ m, the mesh size that could be achieved was approx. 1 ⁇ m.
  • the nonwoven composites thus produced were cut into pieces of a size that completely covered a person's mouth and nose. These pieces are sewn on the edge with the fleece of the larger mesh size on a cotton fabric.
  • the cotton fabric is connected on both sides with an elastic band so that the cut-out piece can be held in place over the mouth and nose when worn.
  • the fleece composite is cut out round and placed on a sieve of the same size made of stainless steel and clamped with this in a ring that contains a support for the stainless steel sieve with a counter ring.
  • the filter produced in this way can now be used in a filter system, e.g. breathing mask, air filter or water filter, depending on the mesh size.

Abstract

L'invention concerne un filtre à base d'un matériau composite non tissé et un procédé de fabrication d'un tel matériau composite non tissé par électrofilage. L'invention concerne en outre l'utilisation d'un tel filtre pour filtrer des gaz ou des liquides.
PCT/EP2021/061335 2020-05-08 2021-04-29 Filtre à base d'un matériau composite non tissé WO2021224115A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102020205839 2020-05-08
DE102020205839.3 2020-05-08

Publications (1)

Publication Number Publication Date
WO2021224115A1 true WO2021224115A1 (fr) 2021-11-11

Family

ID=75801580

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2021/061335 WO2021224115A1 (fr) 2020-05-08 2021-04-29 Filtre à base d'un matériau composite non tissé

Country Status (1)

Country Link
WO (1) WO2021224115A1 (fr)

Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050235619A1 (en) 2002-05-28 2005-10-27 Beate Heinz Filter medium
US20080015328A1 (en) 2004-08-24 2008-01-17 Basf Aktiengesellschaft Thermoplastic Polyurethane Comprising Silane Groups
EP1953286A1 (fr) * 2007-02-01 2008-08-06 Nisshinbo Industries, Inc. Tissu et masque
US20100028553A1 (en) 2007-02-12 2010-02-04 Miroslav Maly Method and device for production of a layer of nanoparticles or a layer of nanofibres from solutions or melts of polymers
US20110210059A1 (en) * 2010-02-26 2011-09-01 Clarcor Inc. Non-pleated tubular depth filter having fine fiber filtration media
KR20170120821A (ko) 2016-04-22 2017-11-01 (주)에프티이앤이 기재섬유와 나노섬유 부직포 간의 부착력이 향상된 나노섬유 적층 복합섬유 및 이를 포함하는 분리막
KR20170120818A (ko) 2016-04-22 2017-11-01 (주)에프티이앤이 기재섬유와 나노섬유 부직포 간의 부착력이 향상된 나노섬유 적층 복합섬유 및 이를 포함하는 분리막
KR20170120807A (ko) 2016-04-22 2017-11-01 (주)에프티이앤이 접착력이 향상된 기재 양면 나노섬유 웹, 이를 이용한 분리막 및 이의 제조방법
WO2019016313A1 (fr) 2017-07-20 2019-01-24 Basf Se Polyuréthane thermoplastique
WO2019058292A1 (fr) 2017-09-20 2019-03-28 Indian Institute Of Technology Delhi Milieux filtrants à base de nanofibres et leurs procédés de fabrication
DE102018100935A1 (de) 2017-11-28 2019-05-29 BLüCHER GMBH Luftdurchlässiges Flächenfiltermaterial und seine Verwendung
US20190160404A1 (en) 2017-11-30 2019-05-30 Nxtnano, Llc Durable nanofiber synthetic filter media
CZ33137U1 (cs) * 2019-07-01 2019-08-20 Univerzita Tomáše Bati ve Zlíně Filtrační materiál pro filtraci vzduchu

Patent Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050235619A1 (en) 2002-05-28 2005-10-27 Beate Heinz Filter medium
US20080015328A1 (en) 2004-08-24 2008-01-17 Basf Aktiengesellschaft Thermoplastic Polyurethane Comprising Silane Groups
EP1953286A1 (fr) * 2007-02-01 2008-08-06 Nisshinbo Industries, Inc. Tissu et masque
US20100028553A1 (en) 2007-02-12 2010-02-04 Miroslav Maly Method and device for production of a layer of nanoparticles or a layer of nanofibres from solutions or melts of polymers
US20110210059A1 (en) * 2010-02-26 2011-09-01 Clarcor Inc. Non-pleated tubular depth filter having fine fiber filtration media
KR20170120821A (ko) 2016-04-22 2017-11-01 (주)에프티이앤이 기재섬유와 나노섬유 부직포 간의 부착력이 향상된 나노섬유 적층 복합섬유 및 이를 포함하는 분리막
KR20170120818A (ko) 2016-04-22 2017-11-01 (주)에프티이앤이 기재섬유와 나노섬유 부직포 간의 부착력이 향상된 나노섬유 적층 복합섬유 및 이를 포함하는 분리막
KR20170120807A (ko) 2016-04-22 2017-11-01 (주)에프티이앤이 접착력이 향상된 기재 양면 나노섬유 웹, 이를 이용한 분리막 및 이의 제조방법
WO2019016313A1 (fr) 2017-07-20 2019-01-24 Basf Se Polyuréthane thermoplastique
WO2019058292A1 (fr) 2017-09-20 2019-03-28 Indian Institute Of Technology Delhi Milieux filtrants à base de nanofibres et leurs procédés de fabrication
DE102018100935A1 (de) 2017-11-28 2019-05-29 BLüCHER GMBH Luftdurchlässiges Flächenfiltermaterial und seine Verwendung
US20190160404A1 (en) 2017-11-30 2019-05-30 Nxtnano, Llc Durable nanofiber synthetic filter media
CZ33137U1 (cs) * 2019-07-01 2019-08-20 Univerzita Tomáše Bati ve Zlíně Filtrační materiál pro filtraci vzduchu

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
"Kunststoffhandbuch", vol. 7, 1966, CARL HANSER VERLAG, article "Polyurethane", pages: 103 - 113

Similar Documents

Publication Publication Date Title
DE112007000361B4 (de) Feinfasern und deren Verwendung in Filtrationsanwendungen
EP2121312B1 (fr) Stratifié contenant une feuille et un non-tissé à base de polyuréthane thermoplastique
EP0496848B1 (fr) Microfibres de polyurethane rigide possedant une forte proportion de segment dur, mats non tisses de ces microfibres et procede de soufflage de matiere en fusion pour la production desdites fibres
EP2197952B1 (fr) Mélange de polypropylènes
EP0827451B1 (fr) Stratifie pour retenir les vapeurs organiques, les aerosols et les substances actives biologiques
DE69729936T2 (de) Hochpräzisionsfilter
WO2008034612A2 (fr) Non-tissé léger à propriétés de barrière spéciales
EP2064381A2 (fr) Non-tissé léger à propriétés mécaniques spéciales
EP2529045B1 (fr) Tissus non tissés elastiques ayant une resistance elevée
DE19882922B4 (de) Vliesstoff umfassend schmelzgeblasene Polymerfasern, Verfahren zum Herstellen von Polymerartikeln sowie Verwendung einer Schmelzblasdüse
EP0714950A2 (fr) Films étanches perméables aux gaz à partir de mélanges de polyuréthanes thermoplastiques
DE102007035583A1 (de) Materialien mit auf einem Ende stehenden Fasern
EP2787108A1 (fr) Textile non tissé en fibres mélangées et élément filtre l'utilisant
DE4410921A1 (de) Polymermischung und daraus hergestellte Folien
WO2008049250A1 (fr) Fibres polymères électrofilées microbicides comprenant des nanoparticules de polyéthylène imine pour applications textiles
DE102011003186A1 (de) Dünne, makroporöse Polymerfolien
WO2007101808A1 (fr) Materiau non tisse a base de polyurethanne thermoplastique
DE4339475A1 (de) Knisterfreie, antistatische Polyurethanfolie mit hoher Atmungsaktivität sowie ihre Verwendung
EP0863792B1 (fr) Unite de filtration dont l'integrite peut etre controlee et comprenant des membranes hydrophiles et poreuses
WO2021224115A1 (fr) Filtre à base d'un matériau composite non tissé
EP3722476A1 (fr) Matériau composite de nanofibres et de non tissés
DE19729456C1 (de) Integral vliesverstärkte poröse Membranen
EP4021621B1 (fr) Matière composite perméable à la vapeur d'eau
DE4402857A1 (de) Verfahren zum Herstellen eines Mikrofaser-Vliesstoffs, Mikrofaser-Vliesstoff und dessen Verwendung
DE102008034658A1 (de) Verfahren zur Herstellung von Faser-auf-Ende-Materialien

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21723689

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21723689

Country of ref document: EP

Kind code of ref document: A1