CN101387014B - Polymer, polymer microfiber is tieed up, polymer nanofiber and the purposes comprising filtration device structure - Google Patents

Abstract

The invention provides polymer, polymer microfiber is tieed up, polymer nanofiber and the purposes comprising filtration device structure.Disclose a kind of polymeric material of improvement.Further disclose the microfiber material of micrometer fibers and the nanofibrous structures obtained by the polymeric material improved.Micrometer fibers and nanofibrous structures can be used for the various useful purposes comprising shaped filtration material.The invention provides a kind of fine fibre, described fine fibre comprises the resin-like additive component that condensation polymer and crosslinking agent or molecular weight are about 500-3000, described condensation polymer is not the copolymer of cyclic lactam and C6-10 diamine monomer or C6-10 diacid monomer, the diameter of described fiber is 0.01-5 micron, expose 1-6 hour in the air of 140 °F and 100% humidity after, the fiber of at least 30% remains unchanged substantially, and comprises the fibrage of this fiber.

Description

Polymer, polymer microfiber is tieed up, polymer nanofiber and the purposes comprising filtration device structure

Patent application of the present invention is the divisional application of No. 200510116222.0 Chinese invention patent application, this application is international application no is PCT/US 01/24948, international filing date is August 9 calendar year 2001, the application number entering National Phase in China is 01815165.5, denomination of invention be " polymer; polymer microfiber is tieed up, polymer nanofiber and comprise filtration device structure purposes " the divisional application of application for a patent for invention.

The application is the pct international patent application submitted to the name of Donaldson limited company (the said firm is u s company and resident) August 9 calendar year 2001, specify the All Countries except the U.S., and require the U.S. Serial No.60/230 that on September 5th, 2000 submits to, 138 and May 31 calendar year 2001 submit to U.S. SerialNo.09/871, the priority of 590.

Technical field

The present invention relates to the polymeric material manufacturing and there is the environmental stability that improve heat, humidity, reactive materials and mechanical stress.These materials can be used to be formed has the stability of improvement and the fine fibre of intensity, as micrometer fibers and nanofiber.Along with the reduction of fiber size, the durability of material becomes a problem day by day.These fine fibres can be used for various uses.In one application, filtration device structure can use this fine fiber technology to prepare.The present invention relates to polymer, polymer composition, fiber, filter, filtration device structure and filter method.Application of the present invention in particular to from fluid stream, such as, in air stream and liquid (such as non-water and water) stream filtering particle.The technology described relates to the structure in filter medium with one or more layers fine fibre.The size of composition and fiber will be selected in conjunction with its performance and durability.

Background technology

The present invention relates to the polymer composition of the performance with improvement, it can be used for various uses, comprises and forms fiber, micrometer fibers, nanofiber, fabric, fiber mat, permeable structure as film, coating or film.Polymeric material of the present invention is the composition with certain physical property, and it allows the polymeric material in various physical form and form, has the metamorphism that can tolerate moisture, heat, air-flow, chemical reagent and mechanical stress or impact.The invention still further relates to for filter fluid comprise gaseous state and liquid filter medium field.Filter medium comprises the micrometer fibers or nano fabrics layer that the base material at least in the filtration device structure of mechanically stable is combined.When fluid passes through filter medium as gas or liquid, these layers together provide efficiency when excellent filtration, high granule capturing ability and minimum discharge limit.Base material can be arranged in before fluid, below or at interior layer.In recent years, use filter medium be used for filter, namely from fluid as gas or liquid remove the attention that unwanted particle has caused each industry.Customary filtration methods be from fluid comprise air stream or other air-flow or from liquid stream as hydraulic fluid, lubricating oil, fuel oil, current and other fluid except degranulation.Such filter method is to micrometer fibers and base material requires mechanical strength, chemistry and physical stability.Filter medium can be in the temperature conditions of wide region, humidity, mechanical oscillation and impact, and the reactivity of carrying secretly in a fluid or non-reacted, in wearing and tearing or non-abrasion particle.And filter medium often requires that filter medium can be in the ability of carrying out auto purification in inverse pressure pulse (surface coating of of short duration adverse current in order to form except degranulation of fluid), or other can remove the mechanism of entrained particles from filter media surface.Pressure differential after reverse purification like this can cause significantly reduction pulse cleaning.Pulse cleaning rear particle capture efficiency generally can not improve, but, pulse cleaningly can reduce pressure differential, save the energy consumption of filter operation.Such filter can remove down from use operation, purifies in water-based or non-aqueous cleansing composition.Then such medium generally forms micrometer fibers on porous substrate intersection fabric by extracting fine fibre out manufactures.Such material filter form of then making needs is as cartridge type, tray type, box, flat, packet mode and pocket type.In these structures, medium is pleated, is rolled into volume, or is placed in supporting construction.

In the non-woven fine fiber filter media of manufacture, employ the various material comprising glass fibre, metal, pottery and many kinds of polymer compositions.For manufacturing the little micron of diameter and nanofiber, employ various technology.A kind of method comprise make in molten state or the material be in the solution that carries out subsequently evaporating through tiny capillary or perforate.Also can be usually used in by use " spinneret " manufactured as the synthetic fiber of nylon and form fiber.The known electrostatic that also can use reels off raw silk from cocoons technology.This technology relates to use hypodermic needle, nozzle, capillary or removable transmitter.These structures can provide polymer liquid liquid solution, then can be attracted to a collecting zone in high-voltage electrostatic field.Penetrate from transmitter due to these materials and accelerate in electrostatic field, can fibre structure be formed by evaporating solvent, and fiber being very thin.

Due to the application of the harshness being more used for filter medium can be envisioned, require that performance significantly improved material can stand 100 ~ 250 °F, be up to that high flow rate and standing that the high temperature of 300 °F, 10 ~ 90% is up to the high humility of 100%RH, gas and liquid filters micron and submicron particles (more than about 0.01 ~ 10 micron), removing grinding and non-abrasive and rigors that is active and non-active particles from fluid.

Therefore, really need high performance polymer material, micron and nano-fiber material and filtration, be used for filtering high temperature, high humility, high flow rate there is the fluid of described micron and submicron particles material.

Summary of the invention

The invention provides a kind of polymeric material of improvement.This polymer has the physics and chemistry stability that improve.This polymeric fine fibers (micrometer fibers and nanofiber) can be made into useful product form.Nanofiber is that diameter is less than the 200 nanometers i.e. fiber of 0.2 micron.Micrometer fibers is that diameter is greater than 0.2 micron, but is not more than the fiber of 10 microns.These fine fibres can be made into the form of the multilayer microfiltration dielectric structure of improvement.Fine fiber layer of the present invention comprises the random combining the fine fibre forming intersection fabric.Mainly due to fine fiber barrier particle path and can strainability be obtained.Thin fine paper base material combined thereon is had to provide rigidity, intensity and pleated property.Fine fibre crossover network has a key property, i.e. have relatively little space between the fine fibre of micrometer fibers or form of nanofibers.Such fiber gap is usually between about 0.01-25 micron, or about 0.1-10 micron.The filter product comprising fine fiber layer and cellulose layer and the suitable base material selected is very thin.The filter medium gross thickness that fine fibre makes fine fibre add base material adds less than 1 micron.In using, the particle contained by filter can stop by fine fiber layer, and can reach the area load amount of significant arrested particles.Dust or other particles containedly form rapidly dust filter cake at filter surfaces, and keep high initial and overall particle removing efficiency.

The polymeric material disclosed at this significantly improves heat, humidity, high flow rate, reverse pulse purification, operational wear, submicron particles, the purification of use middle filtrator and the tolerance of other harsh conditions detrimental effect.Improve the result that micrometer fibers and nanofiber performance are the improvement the characteristic of the polymeric material forming micrometer fibers or nanofiber.And, use the filter medium of the present invention of the polymeric material of improvement of the present invention to provide many advantages, comprise efficient, low discharge restriction, high-durability (with stress or environmental correclation) under abrasion particles existence condition and there is no the smooth outer surface of loose fiber.The general structure of filtering material provides the medium of overall thin, is improved the media area of unit volume, is decreased through the speed of medium, improves medium efficiency and reduces flow restriction.

A better mode of the present invention is polymeric blends, comprise the first polymer and the second polymer, described two kinds of polymer are the different polymer (different in polymer type, molecular weight or physical property) at high temperature through adjustment or process.Described polymer mixture can react and forms single chemical substance or be blended into mixed composition by annealing process physics.Annealing means physical change, as the change in degree of crystallinity, stress relaxation or orientation.Good material energy chemical reaction becomes one matter, and making to disclose through the analysis of differential scanning calorimeter is single polymer material.When mixing with preferred additive material, this material can be formed in the additive surface coating on micrometer fibers, can provide the stability of oleophobic property, hydrophobicity or other relevant raising when being in high temperature, high humility and difficult operating condition.The diameter of this kind of fine fibre be 2 microns to being less than 0.01 micron.This fine fibre can have the smooth surface comprising the different layer of additive material or additive material outer covering layer, described additive material be partly dissolved in form alloy on polymer surfaces or in polymer surfaces or two kinds all have.Preferred material for mixed polymeric system comprises nylon 6, nylon66 fiber, NYLON610, nylon (6-66-610) copolymer and other linear aliphatic nylon composite.A kind of molecular weight of preferably nylon multipolymer resins (SVP-651) is analyzed with terminal group titration.(J.E.Walz and Taylor, determination ofthe molecular weight of nylon, Anal.Chem.Vol.19, Number7, pp448-450 (1947)).Its number-average molecular weight (M _n) be 21,500 ~ 24,800.Nylon 6 with about 45%, the nylon66 fiber of about 20% and about 25% the melting temperature phasor of these three kinds of component nylon of NYLON610 d estimate described composition.(the 286th page, Nylon Plastic Handbook, Melvin Kohan ed.Hanser Publisher, NewYork (1995)).

The physical property of SVP-651 is:

Hydrolysis degree is that the polyvinyl alcohol of 87.0 ~ 99.9+% may be used for this polymeric system.These systems should be cross-linked and and the oleophobic property of significant quantity and hydrophobic additive material mix.

Another preferred mode of the present invention relates to the mixed single polymers material having compositions of additives, and this additive is used to the service life or the operating characteristics that improve fiber.This one side of the present invention preferred polymers used comprises nylon polymer, polyvinylidene chloride polymers, polyvinylidene fluoride polymer, polyvinyl alcohol polymer, and especially listed can make micrometer fibers or nanofiber have those materials of formation coating in its surface when they mix with strong oleophobic property and hydrophobic additive.And the mixture of mixture as these nylon, these polyvinyl chloride, these polyvinylidene fluoride of these polymer is very useful in the present invention.And the present invention also can imagine the mixture or alloy that use different polymer.In this respect, the compatible blend of polymer is very useful in formation microfiber material of the present invention.The compositions of additives as fluorosurfactant, nonionic surfactant, low-molecular-weight resin (tertiary butylphenol resin that such as molecular weight is less than 3000) can be used.Described resin with the oligomeric bonding under the existence condition not having methylene bridge bond group between phenol core for feature.Hydroxyl and the tert-butyl group can random sites around ring.Bonding between phenol core occurs by hydroxyl usually, instead of random.Similarly, described polymeric material can mix with the non-linear polymerized resin formed by bisphenol-A dissolving in alcohol.This material type is similar to above-mentioned tert-butyl phenol, it does not exist any bridge bond group as sub-alkene or methylene condition under utilize oligomeric key to be directly connected on aromatic rings by aromatic rings to be formed.

The especially preferred material of the present invention is the microfiber material that diameter is about 0.01 ~ 2 micron.Preferred fibre diameter is 0.05 ~ 0.5 micron.This fiber with preferred size can provide excellent strainability, is easy to reverse pulse purification and other side.The preferred polymeric system of the present invention has attachment characteristic, when contacting with fibrous substrate, can be attached on base material with enough intensity, and can resist the delamination effect of reverse pulse purification techniques and other mechanical stress.In this fashion, described polymer raw material must be attached on base material always, can stand to be equivalent to except inverse outwardly through the pulse cleaning active force of the conventional filtration condition of filtration simultaneously.During when fiber and substrate contact or with fiber on heat or pressure post processing base material, this adhesive force is from fibroplastic solubility effect.Such as, but the characteristic of polymer, being similar to the specified chemical interaction of hydrogen bond, more than Tg or the contact between the polymer occurred below and base material and comprising the polymer formulators of additive, playing an important role when determining adhesive force.When bonding, the polymer of solvent or water vapour plasticising can improve its bonding force.

The important aspect of the present invention one utilizes this micrometer fibers or nanofiber to form filtration.In such an embodiment, fine fiber material of the present invention to be formed on filtering substrate and to be attached on filtering substrate.Natural fabric and synthetic fiber base material can be used as the fabric of the supatex fabric of nonwoven fabric, synthetic fiber and the supatex fabric manufactured by the mixture of cellulose, synthetic fiber and glass fibre, non-woven and woven glass fibre, and plasticity textile material is as extruded UF and the MF film with the material of punching and organic polymer.Then flat substrates or cellulose nonwoven fabric are made filtration, be placed in the fluid comprising air stream or liquid stream the particle being used for removing in fluid and suspending or carry secretly.The shape of described filtering material and structure will conform with the requirement of design engineer.An important parameter after filter element is formed is that it is to heat, humidity or both tolerances.An aspect of filter medium of the present invention is test filtering material being tolerated to long-time submergence ability in the hot water.Submergence test can provide valuable and contain main the information standing the ability purified in the aqueous solution of strong purification surfactant and overbased materials about fine fibre tolerance wet heat condition and tolerance filtering material.Preferably, fine fiber material of the present invention can submergence in the hot water, and still retain the fine fibre being formed at substrate surface of at least 50%.The retention of fine fibre at least 50% can keep enough fiber efficiency, does not lose filtration capacity simultaneously or increases back pressure.It is preferred that at least retain 75%.

Fine fiber filter structure comprises two-layer or sandwich construction, and filter comprises one or more layers fine fiber layer, and fine fiber layer is combined with one or more layers synthetic fiber, cellulose fibre or mixed goods or is separated by it.

We think that fiber is relevant with temperature tolerance, humidity or moisture tolerance and solvent tolerance with the key property of micrometer fibers in filtration, especially when micrometer fibers is at elevated temperature with wet environment or solvent contacts.And the second key property of material of the present invention relates to the tack of material and matrix structure.The tack of microfiber layer is a key property of filtering material, can make manufacture material can not with base material layering, microfiber layer adds that base material can be processed into and comprises fold, roll and other structure, and does not have remarkable layering.Find, in the heating steps of manufacture process, to rise to a kind of melting temperature of polymeric material close or proper lower than this temperature for temperature, is usually less than minimum melting temperature, can significantly improves the adhesive force of fiber each other and between fiber and base material.Fine fibre can lose its fibre structure at fusing point or higher than melting temperature.Control firing rate also very important.As fruit fiber is in its crystallization temperature over a long time, also its fibre structure can be lost.Careful heat treatment also can improve polymer property, and this is owing to moving to surface when additive materials and forming the cause of external additive layer when fiber surface display hydrophobicity or oleophobic group.

The standard of performance is that material can be remained valid at various operating temperatures, namely according to final purpose, keeps 1 hour or 3 hours effectively, keep the filter efficiency of 30%, 50%, 80% or 90% simultaneously 140 °F, 160 °F, 270 °F and 300 °F.That material can be remained valid at various operating temperatures to another standard of performance, namely according to final purpose, keep 1 hour or 3 hours effectively 140 °F, 160 °F, 270 °F and 300 °F, in filter course, keep effective fine fibre of 30%, 50%, 80% or 90% simultaneously.Can remain valid at these tem-peratures to very important in the water of low humidity, high humility and saturated air.Micrometer fibers of the present invention and filtering material are considered to have resistance to moisture, and material is still remained valid after can being immersed in the water higher than 160 °F, efficiency can be kept to grow to about more than 5 minutes simultaneously.Equally, to be longer than as ethanol, hydrocarbon, hydraulic fluid or aromatic solvent contact with 70 °F of solvents and still to remain valid for about 5 minutes, keep the material of 50% efficiency simultaneously, the solvent tolerance of microfiber material of the present invention and filtering material can be reached.

Fine fiber material of the present invention can be used for various filtration applications, comprise the collection of pulse cleaning and that non-pulse is cleaned filter for dust, gas turbine and engine air inlets or induction system, heavy-duty engine air intlet or induction system, light-duty vehicle engine intake or induction system; Zee filter, cabin air, air in offroad vehicle cabin air, disc driver, photographic copying-toner removing; HAVA filter in commercial filter application or resident's filtration application.

Brief Description Of Drawings

Fig. 1 shows the electrostatic transmitter drive unit of typical production fine fibre of the present invention.

Fig. 2 shows in the formation of fine fibre shown in Fig. 1 technology for fine fibre being guided to the device on filtering substrate.

Fig. 3 compares the small i.e. particulate matter of 2 and 5 microns, shows the typical internal structure of backing material and shows fine fiber material of the present invention separately.

Fig. 4 ~ 11 are the esca analysis spectrum relevant with embodiment 13.

Figure 12 to show in the embodiment of the present invention 5 stability of the microfiber material of 0.23 micron and 0.45 micron.

Figure 13 ~ 16 show compares unmodified nylon copolymer solvent soluble polyamide, the high temperature of embodiment 5 and 6 material and the stability of high humility.

Figure 17 ~ 20 demonstrate two kinds of copolymers, a kind of nylon homopolymer and a kind of nylon copolymer mixture heat treatment and and additive mixed after, just form one-component material, this material do not present the identifiable design feature of two kinds of polymeric materials but display be crosslinked or other modes chemically combined single-phase.

Detailed description of the Invention

Fine fibre in micron of the present invention or nanofiber layer can be that diameter is about 0.001 ~ 2 micron, is preferably the fiber of 0.05 ~ 0.5 micron.The thickness of typical case's fine fiber filter layer is about about 1 ~ 100 times of fibre diameter, and basis weight range is about 0.01 ~ 240 micro-gram per centimeter ².

Fluid is as usually carried particulate matter in air and air-flow.Need to remove some in fluid or all particulate matters.Such as, the air stream of ingress engine motor train compartment, the air in computer disk driver, HVAC air, the ventilating air in clean room uses the purposes of filter bag, barrier fabric, Woven, enters air that is automobile-used or generating equipment engine; The air-flow entering gas turbine and the air stream entered in various combustion furnace, these air-flows often comprise particulate matter.When for cabin air filters, in order to make occupant comfort and/or attractive in appearance, particulate matter should be removed.As for the air stream entered in engine, gas turbine and combustion furnace and air-flow, requiring removing particulate matter, is because particle can produce substantial infringement because of various relevant mechanism to internal workpiece.In other cases, from industrial process or engine output gas or discharge in gas containing particulate matter.Can or should by upstream device by this gas discharging to air before, require the particulate matter in abundant these fluids of removing.

By considering following filter medium: surface loading media and depth media, the general understanding of some general principles in air filter design and problem can be obtained.These media types have been done deep research and have been widely used.Such as, at U.S. patent Nos.5,082,476,5,238,474 and 5,364, describe some principles relevant with them in 456.The content of the announcement of described three patents is in full with reference to being incorporated into this.

" service life " of filter defines according to selected filter limiting pressure usually.The pressure of filter increases and is limited to application service life or designs in the level that limits.Due to the result that this pressure increase is load, concerning the system of same efficiency, the capacity that longer service life is usual and higher has direct relation.The tendency that efficiency characterizes capture medium particle instead of allows particle pass through.Usually, the efficiency of the particle in filter medium removing air-flow is higher, the described filter medium in general faster pressure drop close to " service life " (assuming that other variable keeps constant).In this application, term " filter effect is constant " refers to and keeps the enough efficiency for particle in removal fluid necessary selected purposes.

Stationery filter element is the surface loading media form of extensive use.Generally, stationery parts comprise the intensive pad of cellulose, synthetic fiber or other fiber, and these fibers are identical with the air-flow orientation of particulate matter.Paper be made generally in can make air-flow through, and there is fully tiny pore-size and suitable porosity, to stop that the particle being greater than selected size passes through.When gas (fluid) is by filter paper, filter paper by spread and interception operates, traps and retains the particle of selected size in air-flow (fluid) in face of air-flow face.Particle is collected in filter cake on its surface.After certain hour, filter cake also starts to operate as filter, improves efficiency.This is called sometimes " timeliness (seasoning) ", and namely efficiency develops into and is greater than initial efficiency.

Simple design for filtration elements existence at least two as described above class problem.The first, the relatively simple defect of paper, namely breaking of paper can cause thrashing.The second, on the face of filter in face of air-flow, particulate matter is piled up rapidly for thin filter cake or layer, adds pressure drop.Adopt various method to increase " life-span " of surface loading filtration system as filter paper.Method is to provide a medium for pleated structure, makes the medium that meets with air-flow larger relative to flat its surface area of corrugationless structure.Though this method can increase the life-span, but still is restricted.Due to this reason, surface loading media is mainly used in by the relatively slow application of the speed of filter medium, is generally not more than about 20-30 feet per minute clock, usually at about 10 feet per minute clocks or the less order of magnitude.Herein, term " speed " is the average speed (i.e. volume flow/media area) by medium.

Generally, when the air velocity by the paper medium of fold improves, filter life with square the declining pro rata of flow velocity.Therefore, use fold paper surface loading filtration system as particulate filter for require air mass flow large system time, need larger filtration media surface area.Such as, the diameter travelling the conventional cylinder fold paper filter parts of the diesel truck on highway is about 9-15 inch, and long 12-24 inch, it is dark that fold is about 1-2 inch.Therefore, the filter table area (simultaneously) of medium is generally 30-300 foot ².

Many application especially relate to those application of quite high flow, use the filter medium of another kind of type, are sometimes called " degree of depth " medium.Typical depth media comprises thicker entangled fiber material.Depth media generally characterizes with its porosity, density or percent solids.Such as, the medium of 2-3% solid content is the about 2-3% that fibrous material (solid) accounts for cumulative volume, and all the other are depth media pads of the fiber of air or the gas compartment.

Another the useful parameter characterizing depth media is fibre diameter.If solid content remains unchanged, and fibre diameter (size) reduces, and the space between aperture or fiber reduces, and namely filter becomes more effective, can more effectively trap less particle.

The depth media filter that typical case commonly uses is dark, and the medium of relative constancy (or consistent) density, namely the solids content of depth media keeps substantially constant on its thickness." substantially constant " is herein if refer to that changing in the entire depth upper density of medium is also only quite little fluctuation.Such change case is produced the cause of slight extruding in this way by the outer surface of the container placing filter medium.

Have studied the device of the depth media of Graded Density, such as United States Patent (USP) 4,082,476,5,238,474 and 5,363, in 456, describe the device that some are such.Generally, the device of depth media can be designed to provide substantially at " load " of the granular materials of its whole volume or the degree of depth.Therefore, such apparatus design becomes when reaching the entire life of filter, relative to the more substantial granular materials of surface loading system energy load.Graded Density system, as those in above-mentioned patent, has been designed to provide significant efficiency and longer life-span.In some cases, use surface loading media as " modifying (the polish) " filter in this sampling device.

Polymeric material has made non-woven and woven fabric, fiber and micrometer fibers.Described polymeric material provides the physical property required by product stability.These materials should obviously not change dimensionally, should not reduce its molecular weight, should not become pliability poor or occur stress crack or occur physical degradation under sunlight, moisture, high temperature or other negative environmental consequences.The present invention relates to running into electromagnetic radiation as the improvement polymeric material of physical property still can be kept when ambient light, heat, moisture and other physical action.

The polymeric material that can be used in Inventive polymers composition comprises addition polymers and condensation polymer as polyolefin, polyacetals, polyamide, polyester, cellulose ether and ester, polyalkylene sulfide, polyoxygenated arylene (polyaryleneoxide), polysulfones, modified polysulfone and their mixture.The preferred material belonging to these classifications comprises with crosslinked and non-crosslinked forms and the polyethylene, polypropylene, polyvinyl chloride, polymethyl methacrylate (with other acrylic resin), polystyrene and their copolymer (comprising ABA block polymer) that exist with various hydrolysis degree (87 ~ 99.5%), polyvinylidene fluoride, the sub-ethene of poly-dichloro and polyvinyl alcohol.(Tg is higher than the room temperature) of preferred addition polymers normally glassy state.This is the situation of polyvinyl chloride and polymethyl methacrylate, polyphenylacetylene combination or alloy or polyvinylidene fluoride and the low crystallization of polyvinyl alcohol material.One class of polyamide condensation polymers is nylon material.Usually, " nylon " term is the common name of all long chain synthetic polyamide.Usually, nylon nomenclature comprises a series of numeral as nylon66 fiber, and expression raw material is C ₆diamines and C ₆(first digit represents C to diacid ₆diamines, second digit represents C ₆dicarboxylic acid compound).Another kind of nylon can be obtained by epsilon-caprolactams polycondensation reaction under a small amount of water existence condition.This reaction formation is the nylon 6 (by being called that the cyclic lactames of episilon amino caproic acid obtains) of linear polyamide.And, also can use nylon copolymer.Copolymer can be mix various diamine compound, various diacid compounds and various cyclic lactames structure in the reactive mixture, then forms the nylon with randomly located monomer material in polyamide structure.Such as, nylon 6,6-6,10 materials are by hexamethylene diamine and C ₆, C ₁₀the nylon that two acid blends are made.Nylon 6-6,6-6,10 is by copolymerization episilon amino caproic acid, hexamethylene diamine and C ₆, C ₁₀the nylon that diacid mixture material is obtained.

Block copolymer also can be used for method of the present invention.For this copolymer, the selection of solvent swell agent is just very important.Selected solvent is the solvent that two kinds of blocks can be dissolved in wherein.Example is ABA (styrene-EP-styrene) in dichloromethane solvent or AB (styrene-EP) polymer.If component is insoluble to a solvent, it will form gel.The example of this block copolymer is type styrene-b-butadiene and styrene-b-hydrogenated butadiene (ethylene propylene (ethylene propylene)), type e-caprolactam-b-oxirane, the polyurethane of polyester-b-ethylene oxide and oxirane and isocyanates.

Addition polymers is as copolymer, polyvinyl alcohol, the poly-ethyl acetate of polyvinylidene fluoride, syndiotactic polystyrene, vinylidene fluoride and hexafluoropropene; Amorphous addition polymers reels off raw silk from cocoons, this is because they can dissolve under low-pressure low-temperature as the copolymer of polyacrylonitrile and it and acrylic acid and methacrylate, polystyrene, polyvinyl chloride and various copolymer, polymethyl methacrylate and its various copolymer can relatively simply carry out solution.But, if high crystallinity polymer reels off raw silk from cocoons as polyethylene and polypropylene will carry out solution, just need the solvent of High Temperature High Pressure.Therefore, polyethylene and polyacrylic solution reel off raw silk from cocoons very difficult.It is a kind of method manufacturing nanofiber and micrometer fibers that electrostatic solution is reeled off raw silk from cocoons.

Find, will the remarkable advantage of polymer composition, alloy form or cross-linking chemistry bonding structure that two or more polymeric materials mix be contained.We think this polymer composition by change polymer property as improved the pliability of polymer chain or chain activity, improve bulk molecule amount and carry out enhancing improve its physical property by forming polymeric material network.

In an embodiment of this idea, two kinds of relevant polymeric materials can be mixed for obtaining useful performance.Such as, high molecular weight pvc and low molecular weight polyvinyl chloride are mixed.Similarly, high molecular weight nylon material and low molecular weight nylon material can be mixed.And, different types of conventional polymer material can be mixed.Such as, high molecular weight styrene can mix with the polystyrene of low molecular weight, high-impact.Nylon 6 material can with nylon copolymer as nylon 6; 6,6; 6,10 copolymers mix.And the polyvinyl alcohol of Lower degrees of hydrolysis such as the polyvinyl alcohol of 87% hydrolysis can be 98 ~ 99.9% and higher completely or the polyvinyl alcohol mixing of super hydrolysis with degree of hydrolysis.These materials all in mixture can utilize suitable mechanism of crosslinking to be cross-linked.Nylon can use the crosslinking agent of the reaction of the nitrogen-atoms in energy and amido link to be cross-linked.Polyvinyl alcohol material can use hydroxyl activity material as single aldehydes, and such as formaldehyde, urea, melamine-formaldehyde resin and analog thereof, boric acid and other inorganic compound, twain-aldehyde compound, two acids, urethanes class, epoxies and other known crosslinking agent are cross-linked.Crosslinking technological is that people know, understandable phenomenon, and crosslinking agent reaction wherein also forms covalent bond between polymer chains, greatly improves molecular weight, chemical resistance, bulk strength and mechanical resistant degradation property.

Find, additive material can significantly improve the performance of fine fiber form polymeric material.The existence of additive can significantly improve its tolerance to heat, moisture, impact, mechanical stress and other Negative environment effect.We have found that when making microfiber material of the present invention, described additive material can improve its oleophobic property, hydrophobicity seem helpful to raising materials chemistry stability.We think because these additives can form protection coating, ablated surface or infiltrate surperficial certain depth to improve the character of polymeric material, can improve the fine fibre of micrometer fibers form of the present invention under these oleophobic properties and hydrophobic additive existence condition.We think that the key character of these materials there is the strong-hydrophobicity group also with fuel shedding quality simultaneously.Strong-hydrophobicity group comprises the oligomeric composition of fluorohydrocarbon group, hydrophobic hydrocarbon based surfactants or block and mainly hydrocarbon.These materials are made the composition with the part energy molecule compatible with described polymeric material; described molecule usually forms physical bond with polymer or associates; simultaneously because the associating of additive and polymer; described strong-hydrophobicity or oleophobic group, formed the protection top layer that is positioned on surface or and polymeric surface layer become alloy or mixed.Concerning 0.2 micrometer fibers with 10% additive capacity, if additive moves to surface, surface thickness calculates and is about due to the incompatibility of oleophobic property in integral material or hydrophobic group, think that migration can occur. thickness concerning protection coating be rational thickness.Be the fiber of 0.05 micron to diameter, thickness correspond to 20 quality %.To the fiber of 2 micron thickness, thickness correspond to 2 quality %.The consumption of described additive material is preferably about 2 ~ 25 % by weight.The oligomer additive used together with Inventive polymers material comprises the oligomer that molecular weight is about 500-3000, should be comparatively fluorochemical, nonionic surface active agent and low-molecular-weight resin or oligomer.

The present invention's fluorine-containing organo wetting agents used is the organic molecule be expressed from the next:

Rf-G

In formula, R _ffor fluorine-containing aliphatic radical, G is as the group of CATION, anion, nonionic or amphiprotic group containing at least one hydrophilic radical.Preferred non-ionic material.R _fbe at least containing two carbon atoms fluoridize monovalent aliphatic organic free radical.It is preferably saturated perfluorinated polyether unit price organic free radical.But hydrogen atom or chlorine atom can alternatively exist in skeletal chain by base.Although the free radical containing many carbon atoms can fully work, preferably containing the compound being no more than 20 carbon atoms, because compare short skeletal chain, the utilization ratio of the fluorine of large free radical is lower.R _f2 ~ 8 carbon atoms should be contained.

Cation group useful in fluorine-containing organic reagent used in the present invention can comprise can oxygen-free atom (such as ,-NH ₂) or containing the amine of oxygen atom (such as, amine oxide) or quaternary ammonium salt cationic group.This amine and quaternary ammonium salt cationic hydrophilic radical can have following general formula :-NH ₂,-(NH ₃) X ,-(NH (R ²) ₂) X ,-(NH (R ²) ₃) X or-N (R ²) ₂→ O, in formula, X is counter anion, as halogen ion, hydroxyl, sulfate radical, bisulfate ion or carboxylate radical, R ²for H or C _1-18alkyl, and each R ²group each other can be identical or different.R ²be preferably H or C _1-16alkyl, and X is preferably halogen ion, hydroxyl or bisulfate ion.

The present invention's anionic group useful in fluorine-containing organo wetting agents used comprises the group that can be become radical anion by ionization.Described anionic group can have following general formula :-COOM ,-SO ₃m ,-OSO ₃m ,-PO ₃hM ,-OPO ₃m ₂or-OPO ₃hM, in formula, M is H, metal ion, (NR ¹ ₄) ⁺or (SR ¹ ₄) ⁺, wherein R ¹be H or replacement or do not replace C independently of one another ₁~ C ₆alkyl.M is preferably Na ⁺or K ⁺.In the present invention, the anionic group of preferred fluorine-containing organo wetting agents has-COOM and-SO ₃the general formula of M.Anion fluoride-containing organo wetting agents comprises anionic polymer material, and it is obtained by the ethylene linkage unsaturated monocarboxylic containing fluorohydrocarbon side base on it and diacid monomer usually.This material comprises the surfactant being called FC-430 and FC-431 obtained from 3M company.

The present invention's amphiprotic group useful in fluorine-containing organo wetting agents used comprises the group containing at least one above-mentioned cation group and at least one above-mentioned anionic group.

The non-ionic group useful in fluorine-containing organo wetting agents that the present invention is used, comprises hydrophilic but can not Ionized group under the pH condition of normal agricultural purposes.Described non-ionic group can have following general formula :-O (CH ₂cH ₂) xOH (wherein x is greater than 1) ,-SO ₂nH ₂,-SO ₂nHCH ₂cH ₂oH ,-SO ₂n (CH ₂cH ₂h) ₂,-CONH ₂,-CONHCH ₂cH ₂oH or-CON (CH ₂cH ₂oH) ₂.The example of this material comprises the material of following structure:

F(CF ₂CF ₂) _n-CH ₂CH ₂O-(CH ₂CH ₂O) _m-H

In formula, n is 2 ~ 8, m is 0 ~ 20.

Other fluorine-containing organo wetting agents comprises such as United States Patent(USP) Nos. 2,764,602,2,764,603,3,147,064 and 4,069, those cationic fluorochemical chemical reagent described in 158.The fluorine-containing organo wetting agents of this both sexes comprises such as United States Patent(USP) Nos. 2,764,602,4,042,522,4,069,158,4,069,244,4,090,967,4,161,590 and 4,161, the fluorine-containing chemical reagent of those both sexes described in 602.This anion fluoride-containing organo wetting agents comprises such as United States Patent(USP) Nos. 2,803,656,3,255,131,3,450,755 and 4,090, the anion fluoride-containing chemical reagent described in 967.

The example of this material is duPont Zonyl FSN and duPont Zonyl FSO non-ionic surface active agent.The another aspect that can be used for the additive in Inventive polymers comprises low molecular weight propylene acid fluorohydrocarbon ester material, as having the Scotchgard material of the 3M company of following general structure:

CF3 (CX ₂) _n-acrylic acid

In formula, X is-F or-CF ₃, n is 1 ~ 7.

And the nonionic alkylene based surfactants comprising lower aliphatic alcohol ethoxylate, fatty acid ethoxylate and nonyl phenol ethoxylate etc. also can be used as the additive material of the present invention.The example of these additive materials comprises Triton X-100 and Triton N-101.

Tert-butyl phenol oligomer as the useful materials of additive material in the present composition.This material aromatic series phenolic resins that molecular weight is lower often.This resin is the novolac polymer prepared by enzymatic oxidation coupling.There is not methylene bridged bond and produce unique chemistry and physical stability.These phenolic resins can with various amine and epoxy crosslinked and compatible with various polymeric material.These materials are illustrated by following general structure usually, it is characterized by repetitive in phenolic materials and there is not the methylene bridged bond with phenolic aldehyde and aromatic group:

In formula, n is 2 ~ 20.The example of these phenolic materials comprises Enzo-BPA, Enzo-BPA/ phenol, Enzo-COP, and other relevant phenolic material can from Enzymol International Inc., and Columbus, Ohio obtain.

It should be understood that as different purposes exists a variety of fiber filter medias.Durable nanofibers of the present invention and micrometer fibers can add in any medium.Fiber of the present invention also can be used for replacing the fibre fractionation in these known media, because its diameter is little, can have the remarkable advantage of improvement performance (raise the efficiency and/or reduce pressure drop), have good durability simultaneously.

Polymer nanofiber and micrometer fibers are known, but because it is to the fragility of mechanical stress, and due to the ratio of its surface area/volume very high and be easy to chemometamorphism, its purposes is very restricted.Fiber of the present invention solves these problems, and therefore can be used for the application different with other of various filtration, fabric, pellicle.

Filter media construction of the present invention comprises the permeable coarse fibrous media layer of ground floor or has the base material of first surface.Ground floor fine fiber media layer is fixed on the first surface of the permeable coarse fibrous media layer of ground floor.Preferably, be the fiber that average diameter is at least 10 microns in the permeable coarse fiber material layer of ground floor, be better about 12 (or 14)-30 microns.Permeable coarse-fibred ground floor should be that basic weight is not more than about 200 grams/meter ², be better about 0.5-150 gram/meter ², be preferably at least 8 grams/meter ²medium.The thickness of permeable coarse fibrous media ground floor is better at least 0.0005 inch (12 microns), is better about 0.001-0.030 inch (25-800 micron).

In preferred device, permeable coarse fiber material ground floor is a kind of material, if tested with this material that Frazier permeability test method pair and the remainder of structure separate, this material just has the permeability of at least 1 m/min, is better about 2-900 m/min.At this, when mentioning efficiency, unless otherwise indicated, refer to and carry out measuring the efficiency of gained with the speed of 20fpm (6.1 ms/min) according to the air-flow of the ASTM-1215-89 monodisperse polystyrene spheric granules of 0.78 micron.

The fine fiber material layer be fixed on the first surface of permeable coarse fibrous media layer is preferably nanofiber media and micrometer fibers medium, wherein the average diameter of fiber is not more than about 2 microns, generally be not more than about 1 micron, be better less than 0.5 micron, and at about 0.05-05 micrometer range.Be fixed on the ground floor fine fiber material on the first surface of the ground floor of permeable coarse fiber material, its gross thickness is better not more than about 30 microns, better be not more than 20 microns, preferably be not more than about 10 microns, be usually more preferably the about 1-8 times of scope (being better not more than 5 times) of this layer of fine fibre average diameter.

Some preferred embodiment of the present invention comprises filter medium, and it is generally generally indicate in total filtration.Some preferred embodiment of such purposes are comprised with cylindrical, has generally by some folds that longitudinal axis equidirectional that is namely longitudinal and cylinder extends.To such device, can as the conventional filter, medium is embedded in two end caps.To typical conventional object, if needed, such device can comprise the lining of upstream and downstream.

In some application, medium of the present invention can be combined with other type media such as conventional media, to improve total strainability or life-span.Such as, medium of the present invention can be laminated in conventional media, uses with stacking form; Or join comprise one or more conventional media region dielectric structure in.Medium of the present invention can use before conventional media to reach well loaded; And/or be applied in after conventional media, be used as efficient modified filter.

Devices more of the present invention also can be used for liquid filter system, are namely that the granular materials that need filter is loaded in a kind of liquid.The present invention also has some devices to can be used for mist collector, such as, for mist in filtered air.

The invention provides filter method.These methods relate generally to use described medium to filter preferably.From described and embodiment below, medium of the present invention can design and structure especially, to be conducive to providing the longer life-span in better efficient system.

Open and the claimed each side using the filtration device structure of the various designs of filtering material in each patent.Authorize the United States Patent (USP) 4 of the people such as Engel, 720,292 disclose a kind of radial seal design for filter assemblies, and this filter assemblies has cylindrical filter element design, this filter element relatively soft rubber-like end cap seal having cylindrical radial to inner surface.The United States Patent (USP) 5,082,476 authorizing the people such as Kahlbaugh discloses the design for filtration elements using depth media, and described depth media includes the foamed substrate of the gathering components combined with the microfiber material of this patented invention.The United States Patent (USP) 5,104,537 of the people such as Stifelman relates to a kind of filtration device structure that can be used for the medium of filter liquide.Liquid entrainment enters into filter housings, is entered in inner loop core, then return by filter outside, in the structure shown here active use.Such filter is particularly useful to filtered fluid hydraulic fluid.The United States Patent (USP) 5,613,992 of the people such as Engel provides a kind of air intake filtration structure of typical diesel engine.This structure obtains air from the outside of housing, in air containing or not containing the moisture carried secretly.Air is by filter, and moisture leads to housing bottom and discharges from this housing simultaneously.The United States Patent (USP) 5 of the people such as Gillingham, 820,646 disclose a kind of Z-shaped filtration device structure, and this structure uses and relates to the inaccessible specific folded design for filtration elements of passage, this channel requirements fluid passes through at least one deck filter medium with Z-shaped path, obtains suitable strainability.The filter medium forming folded Z-shaped pattern can comprise the fine fibre of this invention.The United States Patent (USP) 5,853 of the people such as Glen, bag room structure disclosed in 442, has the filter element comprising this invention fine fiber structure.The United States Patent (USP) 5,954,849 of the people such as Berkhoel shows as dust collection, and after being used for producing a large amount of dust in the environment to processing work, the typical air that process dust load is large, from air stream, Chalk-dust filtering is useful.Finally, the S Design Patent 425,189 of Gillingham discloses a kind of leaf filter using Z-shaped filtration device structure.

the detailed description of some accompanying drawing

Micrometer fibers in unit or nanofiber can be formed by the electrostatic method of reeling off raw silk from cocoons.Figure 1 illustrates the appropriate device for the formation of described fiber.This device comprises storage tank 80, pump 81 and the rotary type emitting device pumped by polymer solution or transmitter 40 that the polymer solution forming fine fibre is wherein housed.Described transmitter 40 usually by swivel joint 41, comprise many offset holes 44 and the rotary part 42 for the axle 43 that connects preposition face component and swivel joint.Described swivel joint 41 is for guiding to polymer solution in preposition face component 42 by quill shaft 43.Described hole 44 is along the circumferential distribution of described preposition face component 42.Described rotary part 42 can be immersed in the polymer storage tank by storage tank 80 and pump 81 charging.Then rotary part 42 obtains polymer from storage tank, and when it rotates in electrostatic field, solution droplets will as described belowly be accelerated by electrostatic field, flies on trapping medium 70.

Stay with it spaced to be fully flat grid, it to be fixed with trapping medium 70 (i.e. substrate or hybrid radix) in the face of transmitter 40.Air can be aspirated by grid.Described trapping medium 70 moves around the cylinder 71 and 72 being fixed on grid 60 two ends.Use suitable electrostatic potential source 61 and be connected to the line 62 and 63 on grid 60 and transmitter 40, between transmitter 40 and grid 60, keep high electrostatic potential.

In use, polymer solution is pumped into swivel joint 41 or storage tank from storage tank 80.Preposition face component 42 rotates, and now liquid leaves hole 44 or extracts out from storage tank, moves from the outer rim of transmitter to the trapping medium 70 be fixed on grid 60.Specifically, the electrostatic potential between grid 60 and transmitter 40 makes electric charge on material webs, causes liquid therefrom to emit as the fine fibre extracted out to grid 60, is collected in base material 12 or has in active layer 14.For the polymer in solution, when they fly to grid 60, the solvent removed by evaporation on fiber.First the fine fibre be bonded on basilar fibers encounters grid 60.Select electrostatic field intensity to guarantee when polymeric material accelerates from transmitter to trapping medium 70, its acceleration is enough to make polymeric material form very thin micrometer fibers or nanofibrous structures.The speed improving or reduce trapping medium movement can deposit more or less fiber on formation medium, controls the thickness of each thin layer of deposition on it thus.Described rotary part 42 can have various useful position.Described rotary part 42 can be placed in on the vertical surfaces of revolution in trapping medium 70 surface, or be positioned at arbitrarily angled on.Described rotating media can positioned parallel, or parallel deviate direction a little.

Fig. 2 is the schematic diagram of the apparatus and method for forming fine fiber layer in sheet form base or medium.In fig. 2, sheet form base is launched by volume on device 20.Then sheet form base 20a is directed to engagement device 21, is here joined together at the bottom of many segment bases for carrying out line operation.The sheet form base of continuous length leads fine fibre process unit 22 again, and comprising the process unit that reels off raw silk from cocoons of Fig. 1, this spinning unit forms fine fibre and is deposited in sheet form base by fine fibre and forms filter course.After form fine fiber layer in sheet form base in forming region 22, fine fiber layer and substrate-guided annealing device 23 carry out suitable process.Then in efficiency monitoring device 24, test sheet form base and fine fiber layer, and if if required, planish planishing in device 25.Then lead sheet form base and fine fiber layer suitable coiler device, reels on wherein suitable spindle for further processing 26 and 27.

Fig. 3 is that display diameter is about the typical dust granule of 2 and 5 microns and the scanning electron microscope diagram at typical fibers medium and typical fine fiber structure mesopore size comparison's relation.In figure 3 a, 2 micron particles 31 and 5 micron particles 32 be obviously greater than at hole in the fiber medium 33 of Typical particle diameter are shown.Form sharp contrast in figure 3b, 2 micron particles are approximately equal to or are greater than in fine fibre knitmesh 35 typical hole between fiber, and 5 micron particles 32 are greater than all holes in fine fibre knitmesh 35.

Filtration useful to Inventive polymers material, the fine fiber material that the present invention includes micrometer fibers and nanofiber and fine fiber material of the present invention above manufactures the general remark of each side, provides understanding the present invention being operated to general technology principle.The concrete exemplary materials of the following stated is the examples of materials that can be used for manufacturing fine fiber material of the present invention, and following material discloses best pattern.Manufacture these exemplary materials, use following characteristic and operating condition.The electrostatic field that uses to improve oneself plays the electrostatic force of pull effect, and polymeric spray thing is pulled into very thin filament, obtains the electrostatic drawn fibers that diameter is less than 10 microns.Although can polymer melt be used in electrostatic drawing process, the most handy polymer solution obtains the fiber being narrower than 1 rice.When polymer form more minor diameter time, solvent evaporated away is also conducive to falling low-fiber size.Based on a variety of causes, the selection of solvent is very crucial.If solvent is dry too soon, so fiber can flatten and diameter is large.If solvent is dry too slowly, solvent can lysigenous fiber again.Therefore rate of drying and fibroplastic cooperation very crucial.When high production rate, a large amount of discharge air can prevent imflammable gas from also reducing the danger of catching fire.Non-flammable solvent is useful.In production environment, process equipment needs purification frequently.The situation that safety and low toxicity solvent can make workman be exposed to hazardous chemical is down to minimum.Electrostatic reel off raw silk from cocoons can the flow velocity of 1.5 miles per minute of every transmitter, the range of 8 inches, the transmitter voltage of 88 kilovolts, the transmitter rotating speed of 200 revs/min and 45% these conditions of relative humidity under operate.

The selection of polymer system is concerning very important given purposes.Pulse cleaning for employing, very thin microfiber layer contributes at the outer surface making provide in the very little situation of the pressure loss particle capture and release.Preferred use diameter is less than 2 microns, should be less than the fibre thin layer of 0.3 micron.Micrometer fibers or between nanofiber and its deposition substrate good tack be very important.When the compound that filter is made up of substrate and micrometer fibers and nanofiber obtains, this compound can be applicable to the excellent filtration medium of auto purification.Purify described surface by repetition pulse dorsad and just have updated filter medium.When applying noticeable effort from the teeth outwards, in substrate there is delamination due to pulse dorsad in the fine fibre of poor adhesion, and described pulse dorsad flows through micrometer fibers from filter interior by substrate.Therefore, good between micrometer fibers attachment and the successful purposes of the attachment between basilar fibers and electrostatic drawn fibers are very important.

The fiber using various polymeric material to obtain can obtain the product adapting to above-mentioned requirements.Have good adherence performance fine fibre can by such as polyvinylidene chloride, polyvinyl alcohol and containing various nylon as the polymer of nylon 6, nylon 4,6, nylon 6,6, nylon 6,10 and copolymer and their copolymer obtain.Can obtain excellent fiber by PVDF, but the fiber manufacturing diameter enough little needs chlorinated solvent.Nylon 6, nylon66 fiber and nylon 6,10 can carry out electrostatic and reel off raw silk from cocoons.But such as formic acid, m-cresols, trifluoroethanol, hexafluoroisopropanol equal solvent or very difficult operation, or very expensive.Because of its hypotoxicity, preferred solvent comprises water, ethanol, isopropyl alcohol, acetone and 1-METHYLPYRROLIDONE.The polymer compatible with this solvent system has been done to study widely.We have found that, the fiber obtained by PVC, PVDC, polystyrene, polyacrylonitrile, PMMA, PVDF needs by extra adhesive bonding method to obtain structural behaviour.We also find when polymer is water-soluble, ethanol, isopropyl alcohol, acetone, methyl alcohol and their mixture and successfully obtained fiber time, they have excellent adhesion property to substrate, can obtain the excellent filtration device being suitable for auto purification thus.When filter be used for very high dust concentration time, by air the back of the body pulse auto purification or stranded be useful.The fiber obtained by the polyamide and polyvinyl alcohol that dissolve in alcohol has been used successfully in this purposes.The polyamide example dissolving in alcohol comprises the Macromelt6238,6239 and 6900 buied from Henkle; The Elvamide 8061 and 8063 buied from duPont and the SVP 637 and 651 buied from Shakespear monofilament Company.Other one group of polyamide dissolving in alcohol is 8 type nylon, alkoxy alkyl modified nylon66 fiber (reference Nylon Plastichandbook, the 447th page, melvin Kohan etc., hanser Publisher, New York, 1995).Polyvinyl alcohol example comprises the PVA-217 buied from Kuraray, Japan, and 224 and the Vinol 540 that buys from Air Products andChemical Company.

Under having been found that filter can be in extreme environmental conditions.Filter in Saudi Arabia desert may be in up to 150 °F or higher temperature.The filter being arranged on Indonesia or U.S. Gulf Coast may be in the temperature of high humility and 100 °F being greater than 90%RH.These filters also may be in the rain.We find, below the cover of the such as mobile device of car, truck, tractor and the filter used in building equipment may be in the condition of high temperature (+200 °F), high humility and other chemical substance.We have studied method of testing to evaluate micrometer fibers system prolonged property under severe conditions.Filter Media Sample to be immersed in hot water (140 °F) 5 minutes or to be in high humility, high-temperature and air stream.

experiment

Following electrostatic drawing process condition is used to produce following material.

Revolving expeller system or capillary needle system is used to reel off raw silk from cocoons obtained following material.These two kinds of systems all can produce substantially identical fibrous material.

Described flow velocity is 1.5 miles per minute of every transmitter, and range is 8 inches, and transmitter voltage is 88 kilovolts, and relative humidity is 45%, and the rotating speed of revolving expeller is 35 revs/min.

embodiment 1: the impact of fiber size

With end group titration (J.E.Walz and G.B.Taylor work " determination of nylon molecular weight ", chemistry annual report Vol.19, Number 7,448-450 page (1947)) analyze the molecular weight of the fine fibre sample that b is prepared by nylon 6,66,610 nylon multipolymer resins (SVP-651).Number-average molecular weight is 21,500-24,800.Yynw composition by the nylon 6 of about 45%, the nylon66 fiber of about 20% and about 25% melt temperature phasor (people's work " nylon plastics handbook " the 286th page such as Melvin Kohan of three kinds of component nylon such as NYLON610, Hanser publishing house, New York (1995)) evaluate.The physical property of SVP 651 resin of report is:

Character	ASTM method	Unit	Representative value
				Proportion	D-792	-	1.08
Water imbibition (24 h immersion)	D-570	％	2.5
				Hardness	D-240	Shore D	65
Fusing point	DSC	℃(°F)	154(309)
				TENSILE STRENGTH@surrenders	D-638	MPa(kpsi)	50(7.3)
Elongation at break	D-638	％	350
				Bending modulus	D-790	MPa(kpsi)	180(26)
Specific volume resistance	D-257	Ω-cm	10 12

Be used for producing the fiber that diameter is 0.23 and 0.45 micron.Sample is immersed in the water of room temperature, air-dry and measure its efficiency.Thicker fiber needs longer time degraded, and palliating degradation degree is lower, as shown in the curve in Figure 12.Although do not wish the restriction being subject to particular theory, look that having the easier compared with fine fibre of higher surface/volume degrades due to the impact of environment., thicker fiber can not be used as effective filter medium.

embodiment 2: crosslinked and phenolic resins and the epoxy resin of nylon fiber

In order to improve the chemical resistance of fiber, test the chemical crosslinking of nylon fiber.With being called that the phenolic resins of Georgia Pacific5137 mixes aforesaid copolyamide (nylon 6,66,610) and is pumped into fiber.The melt temperature of when their mixture of nylon and phenolic resins is expressed as follows:

Composition	Melt temperature (°F)
		Polyamide: phenolic resins=100: 0	150
Polyamide: phenolic resins=80: 20	110
		Polyamide: phenolic resins=65: 35	94
Polyamide: phenolic resins=50: 50	65

We have produced comparable fiber from these mixtures.The mixture of 50: 50 is not cross-linked by heating, because can destroy fibre structure.The mixture heating 65: 35 below 90 DEG C improves the chemical resistance of gained fiber for 12 hours, suppresses its dissolving in alcohol.The mixture of polyamide and epoxy resin can be used, as derived from the Epon 828 of Shell and Epi-Rez 510.

embodiment 3: use fluorochemical additive the surface modification of waterproofing agent

The alcohol deriving from 3M company is added solvable in the forward direction polyamide reeled off raw silk from cocoons fC-430 and 431.Addition is 10% of solid.Scotchgard adds the formation not hindering fiber.The high molecular waterproofing agent that THC platform shows similar Scotchgard finally can not improve water proofing property.As manufacturing firm advised, the Scotchgard sample added be heated 10 minutes at 300 °F.

embodiment 4: with the modification of coupling agent

Polymer film carrys out castable by polyamide together with the titanate coupling agent deriving from Kenrich Petrochemicals Co., Ltd.Titanate coupling agent comprises: isopropyl three isostearoyl titanate esters (KRTTS), neopentyl (hexadiene) are oxidized three (dioctyl) titanium phosphate acid esters (LICA 12), neopentyl (hexadiene) is oxidized three (N-second diaminourea) ethyl zirconate (NZ44).The film of castable is immersed in boiling water.Do not use the control sample of coupling agent to lose intensity immediately, and the sample adding coupling agent maintain its profile until 10 minutes.Fiber (fiber of 0.2 micron) has been pumped into by these samples adding coupling agent.

embodiment 5: with the modification of low-molecular-weight p-tert-butylphenol polymer

Molecular weight is the EnzymolInternational company of oligomer purchased from Ohio state Columbus of the p-tert-butylphenol of 400-1100.These low-molecular-weight polymer being soluble solutions at alcohol, as in ethanol, isopropyl alcohol and butanols.These polymer to be added in aforementioned copolyamide and electrostatic reels off raw silk from cocoons into the fiber of 0.2 micron, there is no disadvantageous consequence.Some polymer and additive can hinder electrostatic drawing process.Different from the phenolic resins of the routine described in embodiment 2, we find that this group polymer can not disturb fiber forming process.

We find that this group additive prevents fine fibre to be subject to the impact of wet environment, as shown in the graph.Figure 13-16 show oligomer 140 °F, provide extraordinary protection under the humidity of 100%, but the performance 160 °F time is not very good.We add this additive of used polymer 5-15%.Find that they are same effective when exposing at high humidity for 140 °F to protection fiber.We also find after fiber stands a bit of time at 150 DEG C, and their performance increases.

Table 1 shows the temperature and time of exposure to the impact of the polyamide fiber containing 10% additive.

The conservation rate of the behind efficiency of table 1.140 °F immersion

This is an astonishing result.We see and use the improvement that water proofing property is had is very large of this class additive.In order to understand how this group additive works, and we use and are called that the surface analysis technique of ESCA analyzes fine fibre mat.Be 10% additive sample shown in table 1 at University of Minnesota's esca analysis, the results are shown in table 2.

The table 2. surface composition ratio of additive (polymer with)

Just start, found that the surface concentration of additive is that the twice of bulk concentration seems do not have what meaning., we think that this molecular weight by additive is explained.The polymer that the molecular weight being about the additive of 600 is formed much smaller than principal fiber.Because their size is less, they can move on the solvent molecule evaporated.Like this, we just can realize the high surfaces concentration of additive.Further process adds the surface concentration of protective additive., concentration within 10 minutes, can not be made to increase 150 DEG C of exposures.So just can show, because long-chain polymer moves around if having time, can occur mixing of these two kinds of components of copolyamide and oligomer molecules.What this analysis told us is suitably select the time of post processing and temperature to improve performance, and processes the impact that the oversize time has reverse side.

We use and are called that the technology of Time of Flight (ToF) SIMS checked the micrometer fibers adding these additives further.This technology bombards object with electronics, and observation has anything to come from surface.The sample not containing additive shows has organic nitrogen material out when bombarding with electronics.This shows that polyamide materials there occurs fracture.This result also show a small amount of impurity, as the existence of sodium and silicon.Containing additive but the sample of not heat-treating (additive concentration on surface is 23%) shows section main matter at the bottom of the tert-butyl group, and observe the little of polyamide and peak clearly.Also observe the of poor quality high-quality peak for 148amu relative with tert-butyl phenol simultaneously.To the sample (learning that surface additive concentration is 50% by esca analysis) having processed 10 minutes at 150 DEG C, check.At the bottom of the display tert-butyl group, section is occupied an leading position, and has faint polyamide peak, checks do not have to show the peak relevant to whole tert-butyl phenol and polymer thereof if really had.Inspection also show and C ₂h ₃the peak that O fragment is relevant.

ToF sims analysis shows, polyamide fiber this can release pollutant in nitrogen fragment and surface that the polymer chain of exposure ruptures in time being subject to bombardment by ions.Add additive but do not heat-treat, then covering not exclusively, showing that additive does not cover in some part of surface.When this surface of ion beam strikes, complete molecule can be released together with section at the bottom of the tert-butyl group of instability.If add additive and carried out heat treatment, just impel and shown to cover completely.In addition, the arrangement of molecule in close ground makes only there is unstable fragment as the tert-butyl group, and may be that CH=CH-OH releases, and the whole molecule of tert-butyl phenol is not released.ESCA and ToF SIMS checks at the different depth place on surface.The darker position that ESCA checks is until 100 dusts, and ToF SIMS only checks 10 angstroms depths.These analyze consistent.

embodiment 6: the exploitation of surface coating copolymer

The nylon of development types 8 is in order to the solvable crosslinkable resin for the preparation of coating and attachment purposes originally.This base polymer polyamide 66 and formaldehyde and alcohol under sour existent condition react obtained (with reference to Cairns, T.L.; Foster, H.D.; Larcher, A.W.; Schneider, A.K.; Schreiber, R.S. work J.Am.Chem.Soc.1949,71,651).This base polymer can reel off raw silk from cocoons and be cross-linked by electrostatic., this polymer forms fiber and is inferior to copolyamide, and crosslinked not easily carries out.

In order to prepare the nylon of type 8, the high-pressure reactor loading 10 gallons in following ratio feeds in raw material:

Nylon66 fiber (duPont Zytel) 10 pounds

Methyl alcohol 15.1 pounds

2.0 pounds, water

12.0 pounds, formaldehyde

Then, at least 135 DEG C are heated to this reactor of nitrogen wash under stress.After reaching required temperature, add a small amount of acid as catalyst.Acid catalyst comprises: trifluoroacetic acid, formic acid, toluenesulfonic acid, maleic acid, maleic anhydride, phthalic acid, phthalic anhydride, phosphoric acid, citric acid and their mixture.Also can use polymer is as catalyst.After adding catalyst, reaction carries out 30 minutes.Viscosity homopolymers solution is defined in this stage.After the reaction time of regulation, the material in high-pressure bottle is transferred to containing methyl alcohol, water and alkali as made reaction short stopping in the bath of ammonium hydroxide or NaOH.After the abundant quenching of solution, it is precipitated in deionized water, form soft particle.Then, by polymer beads centrifugation, then vacuumize.This polymer can dissolve in the mixture of methyl alcohol, ethanol, propyl alcohol, butanols and they and water different proportion, also may be dissolved in the mixture of different alcohol.

The polyamide of the alkoxy alkyl modified type 8 formed like this is dissolved in the mixture of ethanol/water.This polymer solution is with being described in Barris U.S. Patent No. 4,650, and the method for 516 is carried out electrostatic and reeled off raw silk from cocoons.The viscosity of polymer solution increases in time.Usual known polymer viscosity has important effect to decision fiber size.So just be difficult to control commercial size quantity-produced process.In addition, at identical conditions, type 8 polyamide effectively can not form micrometer fibers as copolyamide.; acid catalyst is with the addition of when prepared by solution; as toluenesulfonic acid, maleic anhydride, trifluoromethayl sulfonic acid, citric acid, ascorbic acid etc., and carry out carefully heat treatment to mat of fibers after fibre forming, the fiber of gained has extraordinary chemical resistance (Figure 13).Carefully, fibre structure must not be destroyed at cross-linking stage.

When type 8 polyamide (polyamide B) mixes with the solvable copolyamide of alcohol, we have found an astonishing result.With the alkoxy alkyl modified polyamide 66 that the solvable copolyamide of alcohol substitutes 30 % by weight as SVP 637 or 651 (polyamide A), Elvamide 8061, find cooperative effect.The fibre forming of mixture is more effective than any one independent component.Leaching in ethanol and measure filter efficiency and show the filter efficiency conservation rate being greater than 98%, THC bench teat test show polyamide-based with independent type 8 like result.Such mixture shows, we can obtain the effective fibre forming of copolyamide and the advantage of fabulous filtering feature, and the fabulous chemical-resistant advantage of crosslinked type 8 polyamide.Alcohol soak test indicates non-crosslinked copolyamide consumingly and take part in crosslinked, is maintained the filter efficiency of 98%.

After the mixture of polymer A and B is heated to 250 DEG C (full cross-linked), their DSC (see Figure 17-20) becomes and is difficult to distinguish with independent polymer A, does not have diacritic melt temperature.This mixture indicating polymer A and B is consumingly now the complete polymer be cross-linked to form by polymer B and polymer A.

Similarly, the molten mixture of polyethylene terephthalate and polybutylene terephthalate has similar character.Carry out under the melt temperature of temperature higher than each component in the process of melting operation, ether group occurs and exchanges and form the copolymer of PET and PBT.And our crosslinking temperature is lower than arbitrary independent component.Can not expect that this base exchange occurs at low temperatures.Therefore, be cross-linked by the solution mixing of the polyamide of type A and type B and when the fusing point of temperature lower than each component, we be sure of the polyamide having found that a class is new.

When we add the tert-butyl phenol oligomer (additive 7) of 10 % by weight and carry out heat treated at crosslinked required temperature, we have found better result.We think that the hydroxy functional group of tert-butyl phenol oligomer take part in the reaction with the functional group of the nylon of type 8.We find that this component system provides good fibre forming, improve high temperature and the prolonged property of high humidity and the hydrophobicity to fine fiber layer surface.

We have prepared the mixture sample (sample 6A) of polymer A and polymer B and the mixture sample (sample 6B) of another polymer A, polymer B and additive 7.Then, we define fiber by the electrostatic method of reeling off raw silk from cocoons, and at 300 °F, mat of fibers are exposed 10 minutes and also determine surface composition with ESCA surface analysis.

Table 3: the esca analysis of sample 6A and 6b

Except hydrogen concentration can not provide, ESCA can provide the information about surface composition.It can provide the information of carbon, nitrogen and oxygen.Because additive 7 is nonnitrogenous, we are by comparing the concentration of nitrogen to estimate the ratio of nitrogenous polyamide and unazotized additive.Other qualitative information obtains by detecting the O 1s power spectrum combining energy between 535-527eV.The combination of C=O key can be the combination of about 531eV, C-O key can be 533eV.By comparing the peak height at these two peaks, the relative concentration of the additive be with the polyamide of main C=O and be only with C-O group can be estimated.Polymer B has C-O key because of modification, and the concentration of C-O key will decline when crosslinked.ESCA confirms that this reaction positively there occurs, because demonstrate the relative minimizing (Fig. 4 is the mixture of fibers of polymer A and the polymer B of not heat-treating, and Fig. 5 is the mixture of fibers of having carried out heat treated polymer A and polymer B) of C-O key.When there is point period of the day from 11 p.m. to 1 a.m of additive 7 on the surface, more C-O key can be expected to have.Situation is like this really, by Fig. 6 and 7 visible (mixture of fibers that Fig. 6 is polymer A, polymer B and additive 7 are pumped into, Fig. 7 is that polymer A, polymer B and additive 7 has carried out heat treated mixture of fibers).The concentration that Fig. 6 shows embodiment 7C-O key is improved.This result is consistent with the surface concentration that the XPS multichannel based on Fig. 8-11 is composed.

Tert-butyl group oligomer molecules is shifted to the surface of fine fibre and is formed about hydrophobic coating.The nylon of type 8 has functional group as-CH ₂oH and-CH ₂oCH ₃, we expect that their understand-OH the functional group reactions with tert-butyl phenol.Like this, just can expect to see less oligomer molecules on the fiber surface.Found that our hypothesis is incorrect, and the surface of copolymer has a thin coating.

Sample 6A, 6B and the repeat sample being described in Section 5 are exposed on 160 °F of THC platforms under 100%RH condition.In prosthomere, under sample is exposed to 140 °F and 100%RH.Under these conditions, tert-butyl phenol prevents the degraded of trimer copolyamide., if temperature is elevated to 160 °F and 100%RH, then the ability of tert-butyl phenol oligomer protection trimer copolyamide is below not good.We compare these samples at 160 °F and 100%RH.

Table 4: the conservation rate of fine fibre efficiency after being exposed under 160 °F and 100%R

Sample	After 1 hour	After 2 hours	After 3 hours
				Sample 6A	82.6	82.6	85.9
Sample 6B	82.4	88.4	91.6
				Sample 5	10.1

This shows that sample 6B contributes to preventing the impact of high temperature and high humidity.

When we are by when mat of fibers being exposed to water droplet, more surprising difference can be shown.When DI water droplet is placed on the surface of sample 6A by we, water droplet is sprawled and wet substrates paper immediately in mat of fibers.And time on surface water droplet being placed in sample 6B, this water droplet forms the globule and does not sprawl on mat surface.By adding the oligomer of p-tert-butylphenol, the surface modification of sample 16 is hydrophobicity by we.This series products can be used as water smoke arrester, because water droplet can not by the fine fiber surface layer of sample 6B.

The repeat sample of sample 6A, 6B and the 5th band is placed in the stove that temperature is set as 310 °F.Following table shows, sample 6A and 6b keeps complete, and the sample of Section 5 seriously damages.

Table 5: the retention rate being exposed to fine fibre efficiency after 310 °F

Sample	After 6 hours	After 77 hours
			Sample 6A	100％	100％
Sample 6B	100％	100％
			Sample 5	34％	33％

Although the oligomer adding separately polymer A improves the heat-resisting quantity of fine fiber layer, and what effect adding of additive 7 does not have to being exposed to high temperature.

We clearly illustrate that; protecting the quality product of fine fibre under the mixture of trimer copolyamide, alkoxy alkyl modified nylon66 fiber and tert-butyl phenol oligomer can be provided in rugged environment, can productive rate be improved when manufacturing the mixture of the mixture of trimer copolyamide and tert-butyl phenol oligomer or trimer copolyamide and alkoxy alkyl modified nylon66 fiber simultaneously.The mixture of these two kinds of components also has improvement than single-component system.

embodiment 7: the compatible blend of polyamide and polymer with bis phenol A compound

The polymer that one class is new prepares (Pecora, A by the oxidative coupling of phenol ring; The United States Patent (USP) 4,900,671 (1990) of Cyrus, W. and Peroca, A; Cyrus, W.; The United States Patent (USP) 5,153,298 (1992) of Johnson, M.).Wherein, the attractive especially polymer obtained by the bisphenol-A purchased from Enzymol company.The oxidation of the soybean peroxidase catalysis of bisphenol-A can from bisphenol-A two-OH groups either side.Different from linear bisphenol-A system Merlon, such polymer with bis phenol A compound forms over-expense polymer.Due to the over-expense character of this base polymer, they can reduce the viscosity of polymeric blends.

We find that such polymer with bis phenol A compound can mix with polyamide solution.Hansen ' s solubility parameter of the nylon of report is 18.6 (the CRC publishing house of Florida state Boca Raton publishes for 1985 for " solubility parameter and other cohesion parameter handbook " the 317th page, people's works such as A.Barton).If calculate solubility parameter (" solubility parameter handbook " the 61st page), then the solubility parameter value calculated is 28.0.Because the solubility parameter of these materials is different, expect that they can not mix mutually., we find that they are very easy to mix and provide unexpected performance.

The bisphenol a resin of molecular weight 3,000 and the mixture of copolyamide of 50: 50 is obtained in ethanolic solution.Total concentration in ethanolic solution is 10%.Independent copolyamide can produce the fiber of diameter 0.2 micron.And this mixture forms the soft layer of the fiber of about 1 micron.Molecular weight 7, unstable when the bisphenol-A of 000 is together with copolyamide, easily precipitate.

The DSC of 50: 50 mixtures does not see melt temperature.The melt temperature of copolyamide is at about 150 DEG C, and bisphenol a resin is the clear glassy polymer of Tg about 100.And this mixture of these two kinds of materials does not have obvious melting phenomenon.When fiber mat is exposed to 100 DEG C, this fiber mat disappears.This mixture can be made into fabulous filter medium, and the upper serviceability temperature of this filter medium is not very high, but needs low pressure drop.This polymer system can not be cross-linked with reasonable manner.

embodiment 8: bisphenol-A is as the double action of the solvent in mixture and solid

An astonishing feature of the mixture of polymer with bis phenol A compound is that the polymer with bis phenol A compound in solution form plays similar solvent, and the polymer in solid form then plays solid effect.We find that this double action of bisphenol-A is real unique.

Obtained following formula:

Alkoxy alkyl modified PA 66: polymer B 180g

Bisphenol a resin (molecular weight 3,000): polymer C 108g

190 rank ethanol 827g

Acetone 218g

DI water 167g

Catalyst 9.3g

The viscosity that Brookfield viscosimeter records this mixture is 32.6 centipoises.Total polymer concentration is 19.2%.Containing the solution of the mixture of 19.2% polymer B, its viscosity is more than 200 centipoises.The viscosity of 12% polymer B is singly had about 60 centipoises in similar solvent.This is the obvious example that bisphenol a resin plays similar solvent action, because the viscosity of total solution is lower than the value of expection.The fibre diameter of gained is 0.157 micron.If polymer B participates in fibre forming separately, then the fiber size of expecting should be less than 0.1 micron.In other words, polymer C also participates in fibre forming.We do not know that a component has other example any of unique double action like this.After sample immerses in ethanol, measure filter efficiency and fiber size.After alcohol soaks, remain the filter efficiency of 85.6% and fiber size is constant.It is crosslinked that this shows that polymer C take part in, and plays the effect of similar polymer solids.

Another polymer solution is by following formula preparation:

Alkoxy alkyl modified PA 66: polymer B 225g

Bisphenol a resin (molecular weight 3,000): polymer C 135g

190 ° of rank ethanol 778g

Acetone 205g

DI water 15.7g

Catalyst 11.6g

The viscosity of this mixture is 90.2 centipoises.For the solid of 24%, this is a low-down viscosity number.Moreover this shows that polymer C plays similar solvent in the solution., after this solution electrostatic reels off raw silk from cocoons into fiber, fibre diameter is 0.438 micron.Singly there is 15% solution of polymer B should produce the fiber of about 0.2 micron.When final state, polymer C plays the effect expanding fiber size.Moreover this enforcement shows, such branched polymer is used as solvent in the solution, and is used as solid in final state.Immersion ethanolic solution after, retain 77.9% filter efficiency and fiber size is constant.

embodiment 9: the exploitation of the mixture of crosslinked polyamide/polymer with bis phenol A compound

By resin, alcohol and water mixing, within 2 hours, prepare different samples 60 DEG C of stirrings.Solution be cooled to room temperature and add catalyst wherein, then stirring this mixture 15 minutes.Subsequently, measure the viscosity of solution and be pumped into fiber.

Under indicate following sample:

Formula (g)	Sample 9A	Sample 9B	Sample 9C
				Polymer B	8.4	12.6	14.7
Polymer A	3.6	5.4	6.3
				Polymer C	7.2	10.8	12.6
190 rank ethanol	89.3	82.7	79.5
				Isopropyl alcohol	23.5	21.8	21.0
DI water	18.0	16.7	15.9
				Catalyst	0.45	0.58	0.79
Viscosity (cP)	22.5	73.5	134.2
				Fiber size (micron)	0.14	0.258	0.496

We find that this mixture can produce fiber effectively, and compared with the formula of polymer A, the fiber quality of generation is more than 50%.In addition, the polymer microfibers of gained more chemical resistance.After soaking in alcohol, even if intrinsic crosslinked polymer is only 44% of solid composite, the filter maintenance obtained by these fibers is greater than the filter efficiency of 90% and keeps fibre diameter constant.The terpolymer composition of this copolyamide, alkoxy alkyl modified nylon66 fiber and bisphenol-A generates fibre forming performance again chemical-resistant material.

embodiment 10: the alkoxy alkyl modified copolymer of nylon66 fiber and nylon 46

In the high-pressure reactor of 10 gallons, carry out following reaction, and analyze the polymer of gained.After reaching reaction temperature, add catalyst and react 15 minutes.Subsequently, polymer solution quenching, precipitation, cleaning is also dry.

The DSC of the polymer obtained with nylon 46 and nylon66 fiber shows wide single melt temperature, and it is lower than the melt temperature of the nylon 46 (241 DEG C) of modification or the nylon66 fiber (210 DEG C) of modification.This shows in course of reaction, and two kinds of components can distribute randomly along polymer chain.Like this, we think the random copolymer obtaining nylon 46 with alkoxy alkyl modified and nylon66 fiber.These polymer being soluble solutions are in the mixture of alcohol and alcohol and water.

Character	ASTM	Nylon 6.6	Nylon 4.6
				T m		265℃	295℃
TENSILE STRENGTH	D638	13.700	8.500
				Elongation at break	D638	15-80	60
Tensile yield strength	D638	8000-12,000
				Bending strength	D790	17,8000	11,500
Stretch modulus × 10 3psi	D638	230-550	250
				Izod ft-lb/ inch recess	D256A	0.55-1.0	17
Deflection temperature under bending load 264psi	D648	158	194

These two kinds of nylon are all high crystallization and are insoluble in common alcohol.

Source: contemporary plastics encyclopedia 1998

embodiment 11: the exploitation of the copolymer of copolyamide and alkoxy-modified nylon 46/66 copolymer and quiet the formation of electricity drawn fibers

Use said method that the sample of polymer 10B and 10D (seeing the following form) is made fiber.Successfully carry out electrostatic with alkoxy alkyl modified nylon 46/66 (polymer D) separately to reel off raw silk from cocoons.Polymer D can produce following extra benefit with mixing of polymer A: more effective fibre forming and make more crude fibre and not containing the bridging property of sacrificial polymer D, as shown in the table:

The mass ratio of fiber is multiplied by sectional area to calculate by the total length of fiber.The conservation rate of filter efficiency measures by being immersed in ethanol by fiber sample.After soaking in alcohol, fiber size is constant.

embodiment 12: the electrostatic of crosslinked PVA reels off raw silk from cocoons

PVA powder is purchased from Aldrich Chemicals company.This powder dissolution is in 50/50 mixture of water or first alcohol and water.Before electrostatic reels off raw silk from cocoons, it is made to mix with crosslinking agent and p-toluenesulfonic acid catalyst.Before being exposed to THC platform, the stove fiber mat of gained being placed in 150 DEG C is cross-linked 10 minutes.

	Sample 12A	Sample 12B	Sample 12C	Sample 12D
					PVA degree of hydrolysis	98-99	87-89	87-89	87-89
Molecular weight	31,500-50,000	31,500-50,000	31,500-50,000	31,500-50,000
					PVA concentration (%)	10	10	10	10
Solvent	Water	Mixture	Mixture (c)	Mixture (d)
					Other polymer	Nothing	Nothing	Acrylic acid	Cymel 385
Other polymer/PVA (%)	0	0	30	30
					The retention rate (%) of fiber on THC platform after 1 hour	0(a)	0(a，b)	95(b)	20(b)
The retention rate (%) of fiber on THC platform after 3 hours			90(a)

(a): temperature 160 °F, humidity 100%

(b): temperature 140 °F, humidity 100%

(c): molecular weight 2000

(d): the melamine formaldehyde resin deriving from Cytec company

embodiment 13

Use conventional cellulose air filtration media as substrate.The basic weight of this substrate is 67 pounds/3000 square feet, and the Frazier permeability of falling at 0.5 inch of water is 16 feet per minute clocks, and thickness is 0.012 inch, and LEFS efficiency is 41.6%.Described method is used the fine fiber layer that the nominal staple diameter of embodiment 1 is 0.2 micron to be added on substrate surface.The LEFS efficiency of gained compound is 63.7%, under 100% relative humidity, the sample of just substrate is exposed to the air of 140F after 1 hour, and allow sample cool and drying, its LEFS efficiency is 36.5%.Air compound being exposed to 140F under 100% relative humidity is after 1 hour, and allow sample cool and drying, then its LEFS efficiency is 39.7%.Use described mathematical formulae to calculate, the efficiency obtaining the fine fiber layer that exposure retains for 1 hour is afterwards 13%, and the effective fine fibre number of reservation is 11%.

embodiment 14

Use conventional cellulose air filtration media as substrate.The basic weight of this substrate is 67 pounds/3000 square feet, and the Frazier permeability of falling place at 0.5 inch of water is 16 feet per minute clocks, and thickness is 0.012 inch, and LEFS efficiency is 41.6%.Described method is used the fine fiber layer that the nominal staple diameter of embodiment 5 is 0.2 micron to be added on the surface.The LEFS efficiency of gained compound is 96.0%.Be exposed to by the sample of just substrate in the air of 160F after 3 hours under 100% relative humidity, allow sample cool and drying, its LEFS efficiency is 35.3%.Air compound being exposed to 160F under 100% relative humidity is after 3 hours, and allow sample cool and drying, then its LEFS efficiency is 68.0%.Use described mathematical formulae to calculate, the efficiency obtaining the fine fiber layer that exposure retains for 3 hours is afterwards 58%, and the effective fine fibre number of reservation is 29%.

embodiment 15

Use conventional cellulose air filtration media as substrate.The basic weight of this substrate is 67 pounds/3000 square feet, and the Frazier permeability of falling at 0.5 inch of water is 16 feet per minute clocks, and thickness is 0.012 inch, and LEFS efficiency is 41.6%.Described method is used the fine fiber layer that the nominal staple diameter described in embodiment 6 is the polymer A of 0.2 micron and the mixture of polymer B to be added on the surface.The LEFS efficiency of gained compound is 92.9%.Be exposed to by the sample of just substrate in the air of 160F after 3 hours under 100% relative humidity, allow sample cool and drying, its LEFS efficiency is 35.3%.Be exposed to by compound under 100% relative humidity in the air of 160F after 3 hours, allow sample cool and drying, then its LEFS efficiency is 86.0%.Use described mathematical formulae to calculate, the efficiency obtaining the fine fiber layer that exposure retains for 3 hours is afterwards 96%, and the effective fine fibre number of reservation is 89%.

embodiment 16

Use conventional cellulose air filtration media as substrate.The basic weight of this substrate is 67 pounds/3000 square feet, and the Frazier permeability of falling at 0.5 inch of water is 16 feet per minute clocks, and thickness is 0.012 inch, and LEFS efficiency is 41.6%.Use that the nominal staple diameter described in embodiment 6 is the polymer A of 0.2 micron by described method, the fine fiber layer of the mixture of polymer B and tert-butyl phenol oligomer is added on the surface.The LEFS efficiency of the compound of gained is 90.4%.Be exposed to by the sample of just substrate in the air of 160F after 3 hours under 100% relative humidity, allow sample cool and drying, its LEFS efficiency is 35.3%.Be exposed to by compound under 100% relative humidity in the air of 160F after 3 hours, allow sample cool and drying, then its LEFS efficiency is 87.3%.Use described mathematical formulae to calculate, the efficiency obtaining the fine fiber layer that exposure retains for 3 hours is afterwards 97%, and the effective fine fibre number of reservation is 92%.

embodiment 17

Use conventional cellulose air filtration media as substrate.The basic weight of this substrate is 67 pounds/3000 square feet, and the Frazier permeability of falling at 0.5 inch of water is 16 feet per minute clocks, and thickness is 0.012 inch, and LEFS efficiency is 41.6%.Described method is used to be that the fine fiber layer with polyacrylic crosslinked PVA of 0.2 micron is added on the surface by the nominal staple diameter of embodiment 12.The LEFS efficiency of the compound of gained is 92.9%.Be exposed to by the sample of just substrate in the air of 160F after 2 hours under 100% relative humidity, allow sample cool and drying, its LEFS efficiency is 35.3%.Be exposed to by compound under 100% relative humidity in the air of 160F after 2 hours, allow sample cool and drying, then its LEFS efficiency is 83.1%.Use described mathematical formulae to calculate, the efficiency obtaining the fine fiber layer that exposure retains for 3 hours is afterwards 89%, and the effective fine fibre number of reservation is 76%.

embodiment 18

Following filter medium is obtained by the method described in embodiment 1-17.

test method

hot-water dipping test

Use filter efficiency as the measurement of the fine fibre number effectively and functionally retained in the structure, this method more feasible than other has some advantages as SEM detects.

-filtering that to measure be make an appraisal to the medium of several square inches, this can only observe zonule (being usually less than 0.0001 square inch) than SEM microphotograph can draw better mean value.

-filter to measure and can determine the fibre number keeping filtration in the structure.Though those retain, but combine in groups or otherwise in the structure changed the fiber that exists just be presented in the efficiency and function recorded.

However, in the fibre structure that filter efficiency not easily records, other method still can be used to evaluate to the fiber percentage measuring reservation relative to 50% retention criteria.

Illustrate:

This test is the accelerated test representing filter medium WATER RESISTANCE.This test uses LEFS testing stand to measure the performance change of water-immersed filter medium.Water temperature is conclusive parameter, and test period is reduced to the ability that minimum needs and test distinguish media type and selects water temperature by the durability empirical results of the medium obtained according to research institute.General water temperature is 70 °F, 140 °F or 160 °F.

Program:

Next 4 " the samples of diameter are cut from medium.Use the latex balloon of 0.8 μm as the test pollutant in the LEFS operated under 20FPM condition (about the description of LEFS test, see ASTM standard F1215-89) platform, calculate the particle capture efficiency of sample.Then, sample to be immersed in (being generally 140 °F) distilled water 5 minutes.Sample is placed in and stoving rack is allowed to condition at dry (generally spending the night) under room temperature.After samples dried, use the condition identical with initial calculation testing efficiency again on LEFS platform.Previous step is repeated to the substrate (but not having fine fibre in the above) that fine fibre supports.

The efficiency composition only caused due to fine fibre and the final loss in efficiency caused due to the destruction of water can be calculated by the above results.After determining the loss in efficiency caused due to fine fibre, the amount of the efficiency of reservation can be calculated.

Calculate:

Fine fiber layer efficiency: E _i=initial compound efficiency;

E _s=initial substrate efficiency;

F _e=fine fiber layer

F _e＝1-EXP(Ln(1-E _i)-Ln(1-E _x))

The efficiency that fine fiber layer retains: F _i=initial fine fiber layer efficiency;

F _xfine fiber layer efficiency after=leaching;

F _rthe fine fibre of=reservation

F _r＝F _x/F _i

The percentage with the reservation fine fibre of effective efficiency also can be calculated by following formula:

％＝log(1-F _x)/log(1-F _i)

Qualified/defective standard: the reservation percentage > 50% of efficiency

In the purposes of the pulse cleaning filter of most industry, if fine fibre efficiency remains at least 50%, then this filter is enough to work.

tHC platform (temperature, humidity)

Illustrate:

The object of this testing stand evaluates the temperature of fine fiber media to rising and the effect of higher humidity under hydrodynamic condition.This test objective is the operating condition simulating any one limit in industrial filter purposes, gas turbine air inlet purposes or heavy engine air admittance environment.Sample is taken out, dry and carry out LEFS test at set intervals.This system is mainly used in simulating wet heat condition, but also can be used for simulation hot/cold and dry condition.

Temperature-31 is to 390 °F

(maximum temperature under 100%RH is 160 °F to humidity 0-100%RH, at this

The longest continuous time under condition is 16 hours)

Flow velocity 1-35FPM

Program:

" the sample of diameter of cutting off one piece 4 from medium.

Use 0.8 μm of latex balloon as the test pollutant in the LEFS platform operated under 20FPM condition, be used for the particle capture efficiency of test sample.Then, sample is inserted in THC medium chuck.

Test period from a few minutes by several days, can be determined according to experimental condition.

Sample is placed on stoving rack, at room temperature dry (generally spending the night).After samples dried, use the condition identical with initial trial testing efficiency again on LEFS platform.

Repeat previous step to fine fibre support base (not having fine fibre above) to test.

The efficiency composition only caused due to fine fibre by above-mentioned test result calculations and the final loss in efficiency caused due to the destruction of soaking alcohol.

Determine the loss in efficiency of fine fibre, the amount of the efficiency of reservation can be calculated.

Qualified/defective standard: the reservation percentage > 50% of efficiency.

In the purposes of the pulse cleaning filter of most industry, if fine fibre efficiency remains at least 50%, then this filter is enough to work.

alcohol (ethanol) soak test

Illustrate:

This test uses LEFS testing stand to measure the change of the filtering medium property be immersed in the ethanol of room temperature.

Program:

" the sample of diameter of cutting off one piece 4 from medium.Use the latex balloon of 0.8 μm as the test pollutant in the LEFS platform operated under 20FPM condition, the particle capture efficiency of test sample.Then, sample to be immersed in alcohol 1 minute.

Sample is placed on stoving rack, at room temperature dry (generally spending the night).After samples dried, use the condition identical with initial trial testing efficiency again on LEFS platform.Repeat previous step to fine fibre support base (not having fine fibre above) to test.The efficiency composition only caused due to fine fibre and the final loss in efficiency caused due to the destruction of soaking alcohol can be calculated by above-mentioned test result.Determine the loss in efficiency of fine fibre, the amount of the efficiency of reservation can be calculated.

Qualified/defective standard: the reservation percentage > 50% of efficiency.

Above-mentioned explanation, embodiment and data are to invention has been elaboration.But, many changes and embodiment can be made to described the present invention.The present invention is embodied in the accompanying claims of this paper.

Claims (18)

1. a fine fibre, described fine fibre comprises the aromatic resin shape additive component that condensation polymer and molecular weight are 500-3000, described condensation polymer is not the copolymer of cyclic lactam and C6-10 diamine monomer or C6-10 diacid monomer, the diameter of described fiber is 0.01-2 micron, and described condensation polymer comprises polyamide polymer.

2. fine fibre as claimed in claim 1, is characterized in that described resin-like additive comprises the oligomer containing dihydroxybiphenyl base.

3. fine fibre as claimed in claim 1, is characterized in that described additive forms the hydrophobic coating be positioned on fine fiber surface.

4. fine fibre as claimed in claim 3, is characterized in that the thickness of described coating is less than 100 dusts.

5. fine fibre as claimed in claim 1, is characterized in that described polyamide polymer comprises at least one being selected from following component: polyamide copolymer and aromatic polyamide.

6. fine fibre as claimed in claim 1, it is characterized in that described condensation polymer comprises the first nylon polymer mixed with the second nylon polymer, described second nylon polymer is different from the first nylon polymer in molecular weight or monomer composition.

7. fine fibre as claimed in claim 6, is characterized in that described second nylon polymer comprises alkoxy alkyl modified polyamide.

8. fine fibre as claimed in claim 6, is characterized in that described first nylon polymer to be repetitive is the homopolymers of cyclic lactam.

9. fine fibre as claimed in claim 6, is characterized in that described second nylon polymer comprises nylon copolymer.

10. fine fibre as claimed in claim 6, is characterized in that described polymer carries out process and forms single polymers composition, measures display single-phase material with differential scanning calorimeter.

11. fine fibres as claimed in claim 1, is characterized in that described fine fibre also comprises aromatic resin shape additive, and described resin-like additive comprises molecular weight and is 500-3000 and the oligomer with armaticity, and described additive is miscible in described condensation polymer.

12. fine fibres as claimed in claim 1, is characterized in that described polyamide polymer comprises nylon polymer, the homopolymers of described nylon polymer to be repetitive be cyclic lactam.

13. fine fibres as claimed in claim 5, it is characterized in that described polyamide copolymer comprises the first nylon polymer mixed with the second nylon polymer, described second nylon polymer is different from described first nylon polymer in molecular weight or monomer composition.

14. fine fibres as claimed in claim 1, is characterized in that described additive comprises at least one being selected from following component: the oligomer comprising tert-butyl phenol, the oligomer comprising bisphenol-A, the oligomer comprising dihydroxybiphenyl base and fluorochemical.

15. fine fibres as claimed in claim 1, is characterized in that described fibre diameter is 0.1-0.5 micron.

16. fine fibres as claimed in claim 1, is characterized in that the diameter of described fine fibre is 0.01-0.2 micron.

17. 1 kinds of fine fiber layer comprising fine fibre described in claim 1, is characterized in that the diameter of described fine fibre is 0.01-2 micron, the thickness of described fine fiber layer be the 1-100 of described fibre diameter doubly.

18. fine fiber layer as claimed in claim 17, is characterized in that described fine fiber layer thickness is 1-8 times of described fibre diameter.