CN1763274B - Polymer, polymer microfiber, polymer nanofiber and applications including filter structures - Google Patents

Abstract

The invention discloses an improved polymer material. The invention also discloses a micro-fiber and a micro-fiber material of a nano-fiber structure which are prepared by the improved polymer material. The micro-fiber and the nano-fiber structures can be used in various useful purposes which include the formation of filter material.

Description

Polymer, polymer micron/nanofiber and the purposes that comprises filtration device structure

Patent application of the present invention is that international application no is PCT/US01/24948, international filing date is August 9 calendar year 2001, the application number that enters the China national stage is 01815165.5, denomination of invention be " polymer; polymer microfiber dimension, polymer nanofiber and comprise filtration device structure purposes " the dividing an application of application for a patent for invention.

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

Technical field

The present invention relates to manufacture and there is the polymeric material having improved the environmental stability of heat, humidity, reactive materials and mechanical stress.These materials can be used to form the fine fibre of stability and the intensity with improvement, as micrometer fibers and nanofiber.Along with reducing of fiber size, the durability of material becomes a problem day by day.These fine fibres can be used for various uses.In an application, filtration device structure can be prepared by this fine fibre technology.The present invention relates to polymer, polymer composition, fiber, filter, filtration device structure and filter method.Application of the present invention is particularly related to from fluid stream, for example for example, in air stream and liquid (non-water and water) stream filtering particle.The technology of describing 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 polymer composition that the present invention relates to have the performance of 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 and is the polymeric material of various physical forms 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 at least micrometer fibers or the nano fabrics layer that the base material in the filtration device structure with mechanically stable is combined.When fluid is as gas or liquid during by filter medium, efficiency when these layers provide good filtration, high granule capturing ability and minimum discharge restriction together.Base material can be arranged in before fluid, below or at interior layer.In recent years, use filter medium for filtering, from fluid, remove unwanted as gas or liquid

Particle has caused the attention of each industry.Conventional filtration method is comprise air stream or other air-flow or flow as removed degranulation hydraulic fluid, lubricating oil, fuel oil, current and other fluid from liquid from fluid.Such filter method is to micrometer fibers and base material requires mechanical strength, chemistry and physical stability.Filter medium can be in wide region temperature conditions, humidity, mechanical oscillation and impact, and be entrained in reactive or non-reacted in fluid, in wearing and tearing or non-abrasion particle.And filter medium often requires filter medium to press the ability of carrying out auto purification in pulse (surface coating of the of short duration adverse current of fluid in order to form except degranulation) in contrary, or other can remove from filter medium surface the mechanism of entrained particles.Reverse purification like this can cause significantly reducing the pressure differential after pulse purifies.After pulse purifies, granule capturing efficiency generally can not improve, yet pulse purifies and can reduce pressure differential, saves the energy consumption of filter operation.Such filter can remove down from use operation, in water-based or non-aqueous cleansing composition, purifies.Then such medium generally forms the intersection fabric of micrometer fibers and manufactures on porous substrate by extracting fine fibre out.Then such material makes the filter form that needs 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 manufacturing non-woven fine fiber filter media, the various materials that comprise glass fibre, metal, pottery and many kinds of polymer compositions have been used.For manufacturing micron and the nanofiber that diameter is little, various technology have been used.A kind of method comprises that the material that makes to be in molten state or the solution in evaporating is subsequently through tiny capillary or perforate.Also can be usually used in manufacturing by use and form fiber as " spinneret " of the synthetic fiber of nylon.The known static technology of reeling off raw silk from cocoons of also can using.This technology relates to uses hypodermic needle, nozzle, capillary or removable transmitter.These structures can provide polymer liquid liquid solution, then in Ke high-voltage electrostatic field, are attracted to a collecting zone.Because these materials penetrate and accelerate from transmitter, by evaporating solvent, can form fibre structure, and fiber is very thin in electrostatic field.

Owing to can envisioning the harsh application that is more used for filter medium, require the significantly improved material of performance can stand 100～250 ℉, the high temperature, 10～90% that is up to 300 ℉ be up to 100%RH high humility, gas and liquid high flow rate and can stand to filter micron and submicron particles (more than approximately 0.01～10 micron), from fluid, remove and grind and the strict test of non-abrasiveness and active and nonactive particle.

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 and there is described micron and the fluid of submicron particles material.

Summary of the invention

The invention provides a kind of improved polymeric material.This polymer has the physics and chemistry stability having improved.This polymeric fine fibers (micrometer fibers and nanofiber) can be made into useful product form.Nanofiber is that diameter is less than the i.e. fiber of 0.2 micron of 200 nanometers.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 improved multilayer microfiltration dielectric structure.Fine fiber layer of the present invention comprises in conjunction with the random that forms the fine fibre of intersection fabric.Be mainly due to fine fiber barrier particle path and can obtain strainability.There is thin fine paper base material combined thereon that rigidity, intensity and pleated property are provided.Fine fibre crossover network has a key property, between the fine fibre of micrometer fibers or form of nanofibers, has relative little space.Such fiber gap is conventionally between about 0.01-25 micron, or about 0.1-10 micron.The filter product of the base material that comprises fine fiber layer and cellulose layer and suitably select is very thin.The filter medium gross thickness that fine fibre makes fine fibre add base material has increased less than 1 micron.In use, filter can stop contained particle by fine fiber layer, and can reach the area load amount of significant trapping particle.Dust or other particles containedly form rapidly dust filter cake at filter surfaces, and keep high initial and overall particle to remove efficiency.

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

A better mode of the present invention is polymeric blends, comprises the first polymer and the second polymer, and described two kinds of polymer are at high temperature through the different polymer of adjusting or process (different in polymer type, molecular weight or physical property).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 variation in degree of crystallinity, stress relaxation or orientation.Material energy chemical reaction becomes one matter preferably, and making to disclose through the analysis of poor formula scanning calorimeter is single polymer material.When mixing with preferred additive material, this material can be formed on the additive surface coating on micrometer fibers, and the stability of oleophobic property, hydrophobicity or other relevant raising can be provided when in high temperature, high humility and difficult operating condition.The diameter of this class fine fibre be 2 microns to being less than 0.01 micron.This fine fibre can have and comprises additive material different layer or the smooth surface of additive material outer covering layer, and described additive material is partly dissolved in and on polymer surfaces or in polymer surfaces, forms alloy or two kinds and all have.Preferred material for mixed polymeric system comprises nylon 6, nylon 66, NYLON610, nylon (6-66-610) copolymer and other line style aliphatic nylon composite.With terminal group titration, analyzed the molecular weight of a kind of preferred nylon multipolymer resins (SVP-651).(J.E.Walz and Taylor, determination ofthe molecular weight of nylon, Anal.Chem.Vol.19, Number7, pp448-450 (1947)).Its number-average molecular weight (Mn) is 21,500～24,800.The melting temperature phasor of the nylon 6 with approximately 45%, approximately 20% nylon 66 and these three kinds of component nylon of NYLON610 d of approximately 25% is estimated 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+% can be for this polymeric system.These systems should be cross-linked also and the oleophobic property of significant quantity and the mixing of hydrophobic additive material.

Another preferred mode of the present invention relates to the mixed single polymers material that has compositions of additives, and this additive is for improving service life or the operating characteristics of fiber.The present invention this on the one hand preferred polymers used comprise nylon polymer, polyvinylidene chloride polymer, polyvinylidene fluoride polymer, polyvinyl alcohol polymer, especially listed those materials that can make micrometer fibers or nanofiber have to be formed on its lip-deep coating when they and strong oleophobic property and hydrophobic additive mix.And, the mixture of these polymer as the mixture of these nylon, these polyvinyl chloride, these polyvinylidene fluoride in the present invention of great use.And the present invention also can imagine mixture or the alloy that uses different polymer.In this respect, the compatible blend of polymer in forming micrometer fibers material of the present invention of great use.For example can use, as the compositions of additives of fluorosurfactant, non-ionic surface activator, low-molecular-weight resin (the tert-butyl benzene phenol resin that molecular weight is less than 3000).It is feature that described resin be take the oligomeric bonding between phenol core under the existence condition that there is no methylene bridged bond group.Hydroxyl and the tert-butyl group can be at the random sites of the surrounding encircling.Bonding between phenol core occurs by hydroxyl conventionally, rather than random.Similarly, described polymeric material can be mixed with the non-linearity polymer resin being formed by bisphenol-A that dissolves in alcohol.This materials similar is in above-mentioned tert-butyl phenol, and it does not exist any bridge bond group to utilize oligomeric key directly aromatic rings to be connected on aromatic rings and to be formed under as sub-alkene or methylene condition.

The especially preferred material of the present invention is that diameter is about the micrometer fibers material of 0.01～2 micron.Preferred fibre diameter is 0.05～0.5 micron.This fiber with preferred size can provide good strainability, is easy to reverse pulse and purifies 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 mode, described polymer raw material must be attached on base material always, can stand to be equivalent to the pulse catharsis power of the conventional filtration condition of process filtration except reverse simultaneously.When fiber contacts with base material or during with fiber on heat or pressure post processing base material, this adhesive force is from fibroplastic solubility effect.But, the characteristic of polymer, the polymer formulators that is for example similar to the above or following polymer occurring of specific chemical interaction, Tg of hydrogen bond and the contact between base material and comprises additive plays an important role when determining adhesive force.When bonding, with the polymer of solvent or water vapour plasticising, can improve its bonding force.

Important aspect of the present invention is to utilize this micrometer fibers or nanofiber to form filtration.In this structure, fine fibre material of the present invention is formed on filtering substrate and is attached on filtering substrate.Can use natural fabric and synthetic fiber base material as the fabric of the supatex fabric of nonwoven fabric, synthetic fiber and the supatex fabric of being manufactured by the mixture of cellulose, synthetic fiber and glass fibre, non-woven and woven glass fibre, plasticity textile material is as extruded and the material of punching and the UF of organic polymer and MF film.Then flat substrates or cellulose nonwoven fabric are made to filtration, be placed in the fluid that comprises air stream or liquid stream and be used for removing the particle that suspends or carry secretly in fluid.The shape of described filtering material and structure will conform with design engineer's requirement.An important parameter after filter element forms is that it is to heat, humidity or both tolerances.The Yi Ge aspect of filter medium of the present invention is the test that tolerance is immersed in the ability in hot water for a long time to filtering material.Submergence test can provide valuable and tolerate wet heat condition and tolerate the information that filtering material stands the ability of purification in the aqueous solution that mainly contains strong purification surfactant and overbased materials about fine fibre.Preferably, fine fibre material of the present invention can be immersed in hot water, and still retains at least 50% the fine fibre that is formed at substrate surface.The retention of fine fibre at least 50% can keep enough fiber efficiency, does not lose filtration capacity simultaneously or increases back pressure.Best is at least to retain 75%.

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

We think that the key property of fiber and micrometer fibers is relevant with temperature tolerance, humidity or moisture tolerance and solvent tolerance in filtration, especially when micrometer fibers contacts with wet environment or solvent at rising temperature.And the second key property of material of the present invention relates to the attached property seen of material and matrix structure.The tack of micrometer fibers layer is a key property of filtering material, can make the material manufactured not can with base material layering, micrometer fibers layer adds that base material can be processed into and comprises fold, roll and other structure, and there is no remarkable layering.Find, in the heating steps of manufacture process, temperature rises to a kind of melting temperature of polymeric material or approaches or just lower than this temperature, be usually less than minimum melting temperature, can obviously improve fiber each other and fiber and base material between adhesive force.Fine fibre can be lost its fibre structure at fusing point or higher than melting temperature.Control firing rate also very important.If fruit fiber is over a long time in its crystallization temperature, also can lose its fibre structure.Careful heat treatment also can improve polymer property, and this is due to the cause that moves to surface when additive materials and form external additive layer when fiber surface shows hydrophobicity or oleophobic property group.

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

Fine fibre material of the present invention can be used for various filtration applications, comprise that filter that pulse purification and non-pulse purified is for the collection of dust, gas turbine and engine air import or induction system, heavy-duty engine air intlet or induction system, light-duty vehicle engine intake or induction system; Zee filter, compartment air, air in offroad vehicle compartment air, disc driver, photographic copying-toner is removed; HAVA filter in business filtration application or resident's filtration application.

In a preferred embodiment of the present invention, described resin-like additive comprises the oligomer containing dihydroxybiphenyl base.

In a preferred embodiment of the present invention, the thickness of described coating is less than approximately 100

In a preferred embodiment of the present invention, described fiber comprises polyvinyl alcohol and crosslinking agent, and the amount of described crosslinking agent is about 5-50 % by weight in described polyvinyl alcohol polymer.

In a preferred embodiment of the present invention, described crosslinking agent comprises homopolymers and acid catalyst, and described homopolymers comprises acrylic acid units and molecular weight is about 1000-5000.

In a preferred embodiment of the present invention, when exposing, be greater than approximately 50% fiber survival over 16 hours in approximately 140 °F, the air stream of relative humidity approximately 100%.

In a preferred embodiment of the present invention, in the air of 140 °F and 100% humidity, expose after 3 hours, it is substantially constant that at least 50% fiber keeps.

In a preferred embodiment of the present invention, described additive comprises at least one that is selected from following component: the oligomer that comprises tert-butyl phenol, the oligomer that comprises bisphenol-A, the oligomer that comprises dihydroxybiphenyl base and fluorochemical.

In a preferred embodiment of the present invention, described fibre diameter is about 0.1-0.5 micron.

Brief Description Of Drawings

Fig. 1 has shown the static transmitter drive unit that typical production fine fibre of the present invention is used.

Fig. 2 has shown in the technology of fine fibre formation shown in Fig. 1 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, has shown the typical internal structure of backing material and has shown separately fine fibre material of the present invention.

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

Figure 12 has shown in the embodiment of the present invention 5 stability of the micrometer fibers material of 0.23 micron and 0.45 micron.

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

Figure 17～20 proved two kinds of copolymers, a kind of nylon homopolymer and a kind of nylon copolymers mixture heat treatment and and additive mixed after, just form one-component material, this material do not present two kinds of polymeric materials can recognition feature but show be cross-linked 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 fibre filter course is about approximately 1～100 times of fibre diameter, and basis weight range is about 0.01～240 micro-gram per centimeter ².

Fluid is as conventionally carried particulate matter in air and air-flow.Need to remove some or all particulate matters in fluid.For example, enter the air stream of motor vehicle cabin, the air in computer disk driver, HVAC air, the ventilating air in clean room is used the purposes of filter bag, barrier fabric, woven material, enters air automobile-used or generating equipment use engine; Enter the air-flow of gas turbine and enter the air stream in various combustion furnaces, these air-flows often comprise particulate matter.During Dang Wei compartment air cleaner, in order to make passenger comfortable and/or attractive in appearance, should remove particulate matter.As for the air stream and the air-flow that enter in engine, gas turbine and combustion furnace, require to remove particulate matter, be because particle can produce substantial infringement to internal workpiece because of various relevant mechanism.In other cases, from the output gas of industrial process or engine or discharge in gas and contain particulate matter.Can or should be by upstream device by this gas discharging to before atmosphere, require fully to remove the particulate matter in these fluids.

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

Conventionally define according to selected filter limiting pressure " service life " of filter.The pressure of filter increases and will be limited to application service life or design in the level limiting.Because this pressure increase is the result of load, concerning the system of same efficiency, longer service life, common and higher capacity had direct relation.The tendency that efficiency is characterizing capture medium particle rather than allowing particle pass through.Conventionally, the efficiency that filter medium is removed the particle in air-flow is higher, and in general described filter medium just approaches the pressure drop (supposing that other variable keeps constant) in " service life " sooner.In this application, term " filter effect is constant " refers to the efficiency that keeps particle in enough removal fluids necessary for selected purposes.

Stationery filter element is the surface loading form of medium 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 is made generally in and can makes air-flow see through, and has fully tiny pore-size and suitable porosity, and the particle that is greater than selected size to stop passes through.When gas (fluid) is when the filter paper, filter paper by spreading and interception operates, traps and retains the particle of selected size in air-flow (fluid) in face of air-flow face.Particle is collected and is filter cake on filter paper surface.After certain hour, filter cake also starts to operate as filter, has improved efficiency.This is called " timeliness (seasoning) " sometimes, and efficiency develops into and is greater than initial efficiency.

Simple design for filtration elements existence at least two class problems as described above.The first, the relatively simple defect of paper, breaking of paper can cause thrashing.The second, at filter, in face of particulate matter on the face of air-flow, pile up rapidly for thin filter cake or layer, increased pressure drop.Adopted the whole bag of tricks to increase surface loading filtration system as " life-span " of filter paper.Method is to provide a medium for pleated structure, makes the medium that meets with air-flow larger with respect 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 medium 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, conventionally at approximately 10 feet per minute clocks or the less order of magnitude.Herein, term " speed " is the average speed (being volume flow/media area) by medium.

Generally, when the air velocity of the paper medium by fold improves, filter life is with square decline pro rata with flow velocity.Therefore, the surface loading filtration system of paper of using fold when requiring the large system of air mass flow, needs larger filter medium surface area as particulate filter.For example, the diameter of the conventional cylinder fold paper filter parts of the diesel truck travelling on highway is about 9-15 inch, long 12-24 inch, and 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.For example, the medium of 2-3% solid content is the approximately 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 that characterizes depth media is fibre diameter.If solid content remains unchanged, and fibre diameter (size) reduces, and the space between aperture or fiber reduces, and filter becomes more effective, can more effectively trap less particle.

The conventional depth media filter of typical case is dark, the medium of relatively constant (or consistent) density, and the solids content of depth media keeps substantially constant on its thickness." substantially constant " is herein if refer to that it is only also quite little fluctuation that entire depth upper density at medium changes.Such variation is for example to produce the cause of slight extruding by the outer surface of placing the container of filter medium.

After deliberation the device of depth media of gradient density, for example United States Patent (USP) 4,082, described some such devices in 476,5,238,474 and 5,363,456.Generally, the device of depth media can be designed to provide " load " of the basic granular materials in its whole volume or the degree of depth.Therefore, such device is designed to when reaching the entire life of filter, with respect to the surface loading system more substantial granular materials of loading.Gradient 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 medium as " modifying (the polish) " filter in this sampling device.

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

Can comprise that addition polymers and condensation polymer are as polyolefin, polyacetals, polyamide, polyester, cellulose ether and ester, polyalkylene sulfide, polyoxygenated arylene (polyaryleneoxide), polysulfones, modification polysulfones and their mixture for the polymeric material of polymer composition of the present invention.The preferred material that belongs to these classifications comprises being cross-linked and non-crosslinked form the polyethylene, polypropylene, polyvinyl chloride, polymethyl methacrylate (with other acrylic resin), polystyrene and their copolymer (comprising ABA block polymer) that with various hydrolysis degrees (87～99.5%), exist, polyvinylidene fluoride, the sub-ethene of poly-dichloro and polyvinyl alcohol.Preferred addition polymers is (Tg is higher than the room temperature) of glassy state normally.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.Conventionally, " nylon " term is the common name of all long-chain synthesizing polyamides.Conventionally, nylon nomenclature comprises that a series of numerals are as nylon 66, 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 made by epsilon-caprolactams polycondensation reaction under a small amount of water existence condition.It is the nylon 6 (being made by the cyclic lactames that is called episilon amino caproic acid) of linear polyamide that this reaction forms.And, also can use nylon copolymer.Copolymer can be mixed various diamine compounds, various diacid compounds and various cyclic lactames structure in reactant mixture, then forms the nylon with randomly located monomer material in polyamide structure.For example, 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, the 10th, by copolymerization episilon amino caproic acid, hexamethylene diamine and C ₆, C ₁₀the nylon that diacid mixture material makes.

Block copolymer also can be for method of the present invention.For this copolymer, the selection of solvent swell agent is just very important.Selected solvent is that two kinds of blocks can be dissolved in solvent wherein.An example is ABA (styrene-EP-styrene) or AB (styrene-EP) polymer in dichloromethane solvent.If be insoluble to a solvent, it will form gel.The example of this block copolymer is

type styrene-b-butadiene and styrene-b-hydrogenated butadiene (vinyl propylene (ethylene propylene)),

type e-caprolactam-b-oxirane,

the polyurethane of polyester-b-oxirane and oxirane and isocyanates.

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

Find, will contain the remarkable advantage of the mixed polymer composition of two or more polymeric materials, alloy form or cross-linking chemistry bonding structure.We think that this polymer composition can be by changing polymer property as improved pliability or chain activity, the raising bulk molecule amount of polymer chain and strengthening to improve its physical property by forming polymeric material network.

In an embodiment of this idea, for obtaining useful performance, can mix two kinds of relevant polymeric materials.For example, high molecular weight pvc and low molecular weight polyvinyl chloride is mixed.Similarly, can high molecular weight nylon material and low molecular weight nylon material is mixed.And, can mix different types of conventional polymer material.For example, high molecular weight styrene can be mixed with the polystyrene of low molecular weight, high-impact.Nylon 6 material can be with nylon copolymer as nylon 6; 6,6; 6,10 copolymers are mixed.And, the polyvinyl alcohol of low in hydrolysis degree as the polyvinyl alcohol of 87% hydrolysis can with degree of hydrolysis be 98～99.9% and higher completely or the polyvinyl alcohol of super hydrolysis mix.In mixture, these all materials can utilize suitable mechanism of crosslinking to be cross-linked.Nylon can be used the crosslinking agent of the nitrogen-atoms reaction in energy and amido link to be cross-linked.Polyvinyl alcohol material can be used hydroxyl activity material as single aldehydes, and for example 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 therein also forms covalent bond between polymer chain, greatly improves molecular weight, chemical resistance, bulk strength and resistance to mechanical degradation performance.

Find, additive material can significantly improve the performance of fine fibre 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 micrometer fibers material of the present invention, described additive material can improve its oleophobic property, hydrophobicity and seem helpful to improving materials chemistry stability.We think because these additives can form protection coating, ablated surface or infiltrate the character that surperficial certain depth improves 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 is to have the strong-hydrophobicity group also with fuel shedding quality simultaneously.Strong-hydrophobicity group comprises fluorohydrocarbon group, hydrophobic hydrocarbon based surfactants or block and is mainly the oligomeric composition of hydrocarbon.These materials are made to the composition with the part energy molecule compatible with described polymeric material; described molecule forms physical bond or associated with polymer conventionally; while is associated because of additive and polymer; described strong-hydrophobicity or oleophobic property group, form and be positioned at lip-deep protection top layer or become alloy or mixed with polymeric surface layer.Concerning having 0.2 micrometer fibers of 10% additive capacity, if additive moves to surface, surface thickness calculates and is about 50

.Due to the incompatibility of oleophobic property in integral material or hydrophobic group, think that migration is to occur.50 thickness to protection coating be rational thickness.To diameter, be the fiber of 0.05 micron, 50 thickness correspond to 20 quality %.Fiber to 2 micron thick, 50 thickness correspond to 2 quality %.The consumption of described additive material is preferably approximately 2～25 % by weight.The oligomer additive using together with polymeric material of the present invention comprises that molecular weight is about the oligomer of 500-3000, should be fluorochemical, nonionic surface active agent and low-molecular-weight resin or oligomer.

The present invention's fluorine-containing organic wetting agent used is the organic molecule being expressed from the next:

R _f-G

In formula, R _ffor fluorine-containing aliphatic free radical, G contains at least one hydrophilic radical as the group of CATION, anion, nonionic or amphiprotic group.Preferred non-ionic material.R _fbe at least contain two carbon atoms fluoridize unit price aliphatic organic free radical.It is preferably saturated perfluor aliphatic unit price organic free radical.But hydrogen atom or chlorine atom can be used as substituting group and exist in skeletal chain.Although the free radical that contains many carbon atoms can fully work, preferably contain the compound that is no more than 20 carbon atoms, because compare short skeletal chain, the utilization ratio of the fluorine of large free radical is lower.R _fshould contain 2～8 carbon atoms.

In the present invention, can comprise can oxygen-free atom (for example ,-NH for useful cation group in fluorine-containing organic reagent used ₂) or the amine or the quaternary ammonium salt cationic group that contain oxygen atom (for example, amine oxide).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 useful anionic group in fluorine-containing organic wetting agent used comprises the group that can 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) ⁺, R wherein 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 have-COOM of anionic group of preferred fluorine-containing organic wetting agent and-SO ₃the general formula of M.The organic wetting agent of anion fluoride-containing comprises anionic polymer material, and it is made by the ethylene linkage unsaturated monocarboxylic and the diacid monomer that contain fluorohydrocarbon side group on it conventionally.This material comprises the surfactant that is called FC-430 and FC-431 that Cong3M company obtains.

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

The useful non-ionic group in fluorine-containing organic wetting agent that the present invention is used, comprises hydrophilic but can Ionized group under the pH condition of normal agricultural use.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 that 2～8, m is 0～20.

Other fluorine-containing organic wetting agent comprises for example 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 organic wetting agent of this both sexes comprises for example 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.The organic wetting agent of this anion fluoride-containing comprises for example 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.Can for the additive of polymer of the present invention comprise on the other hand low molecular weight propylene acid fluorohydrocarbon ester material, as there is 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, comprise that the nonionic alkylene based surfactants of lower aliphatic alcohol ethoxylate, fatty acid ethoxylate and nonyl phenol ethoxylate etc. also can be used as the additive material that the present invention use.The example of these additive materials comprises Triton X-100 and Triton N-101.

Useful materials as additive material in the present composition is tert-butyl phenol oligomer.This material aromatic series phenolic resins that molecular weight is lower often.This resin is the novolac polymer of preparing by enzymatic oxidation coupling.Do not exist methylene bridged bond to produce unique chemistry and physical stability.These phenolic resins can with various amine and epoxy crosslinked and compatible with various polymeric materials.These materials are illustrated by following general structure conventionally, it is characterized by repetitive in phenolic materials and do not have 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 be from Enzymol International Inc., Columbus, and Ohio obtains.

It should be understood that and have a variety of fiber filter medias for different purposes.Durable nanofiber 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), has good durability simultaneously.

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

Filter media construction of the present invention comprises the permeable crude fibre dielectric 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 crude fibre dielectric layer of ground floor.Preferably, in the permeable crude fibre material layer of ground floor, be that average diameter is at least the fiber of 10 microns, be better about 12 (or 14)-30 micron.Permeable coarse-fibred ground floor should be that basic weight is not more than approximately 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 crude fibre medium 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 crude fibre material ground floor is a kind of material, if tested with this material that the remainder of Frazier permeability test method pair and structure separates, 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 according to ASTM-1215-89 and with the speed of 20fpm (6.1 ms/min), measure the efficiency of gained with the air-flow of the monodisperse polystyrene spheric granules of 0.78 micron.

The fine fibre material layer being fixed on the first surface of permeable crude fibre dielectric layer is preferably nanofiber media and micrometer fibers medium, wherein the average diameter of fiber is not more than approximately 2 microns, generally be not more than approximately 1 micron, be better less than 0.5 micron, and at about 0.05-0.5 micrometer range.Be fixed on the ground floor fine fibre material on the first surface of ground floor of permeable crude fibre material, its gross thickness is better not more than approximately 30 microns, better be not more than 20 microns, preferably be not more than approximately 10 microns, be conventionally 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 to indicate in total filtration.Some preferred embodiment to such purposes comprise with cylindrical having some folds that generally extend by the longitudinal axis equidirectional of longitudinal and cylinder.To such device, can be 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 as conventional media with other type media, to improve total strainability or life-span.For example, medium of the present invention can be laminated in conventional media, with stacking form, uses; Or join in the dielectric structure that comprises one or more conventional media region.Medium of the present invention can use conventional media above to reach well loaded; And/or be applied in conventional media after, be used as efficient modified filter.

Devices more of the present invention also can be used for liquid filter system, and being needs the granular materials filtering to be loaded in a kind of liquid.The present invention also has some devices to can be used for mist collector, for example, and for filtered air mist.

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 is design and structure especially, to be conducive to better to provide the longer life-span in efficient system.

The each side of the filtration device structure of the open and claimed various designs of using filtering material in each patent.Authorize the people's such as Engel United States Patent (USP) 4,720,292 disclose a kind of design of the radial seal for filter assemblies, and this filter assemblies has cylindrical filter element design, and this filter element is with having cylindrical radial to the relatively soft rubber-like end cap seal of inner surface.The United States Patent (USP) 5,082,476 of authorizing the people such as Kahlbaugh has disclosed the design for filtration elements that uses depth media, and described depth media includes the foamed substrate with the fold parts of the micrometer fibers material combination of this patented invention.The people's such as Stifelman United States Patent (USP) 5,104,537 relate to a kind of can be for the filtration device structure of the medium of filter liquide.Liquid entrainment enters into filter housings, by filter outside, enters in inner loop core, then returns to active use in this structure.Such filter is particularly useful to filtered fluid hydraulic fluid.The people's such as Engel United States Patent (USP) 5,613,992 provides a kind of air intake filtration structure of typical diesel engine.This structure obtains air from the outside of housing, contains or do not contain the moisture of carrying secretly in air.Air is by filter, and moisture leads to housing bottom and discharges from this housing simultaneously.The people's such as Gillingham United States Patent (USP) 5,820,646 disclose a kind of Z-shaped filtration device structure, and this structure is used and related to the specific folded design for filtration elements of inaccessible passage, this passage requires fluid YiZXing path to pass through at least one deck filter medium, obtains suitable strainability.The filter medium that forms folded Z-shaped pattern can comprise the fine fibre of this invention.The people's such as Glen the disclosed bag room structure of United States Patent (USP) 5,853,442, has the filter element that comprises this invention fine fiber structure.The people's such as Berkhoel United States Patent (USP) 5,954,849 has shown for dust collection, is used for processing work in environment, to produce after a large amount of dust, processes the large typical air of dust load, and from air stream, Chalk-dust filtering is useful.Finally, U.S.'s design patent 425,189 of Gillingham discloses a kind of leaf filter that uses Z-shaped filtration device structure.

the detailed description of some accompanying drawing

Micrometer fibers in unit or nanofiber can be formed by the static method of reeling off raw silk from cocoons.Figure 1 illustrates the appropriate device that is used to form described fiber.This device comprises storage tank 80, pump 81 and the rotary-type emitter that polymer solution is pumped or the transmitter 40 that the polymer solution that forms fine fibre is wherein housed.Described transmitter 40 conventionally by swivel joint 41, comprise many offset holes 44 and for connecting the rotary part 42 of the axle 43 of preposition face component and swivel joint.Described swivel joint 41 is for guiding to preposition face component 42 by polymer solution 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 of storage tank 80 and pump 81 chargings.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.

Facing transmitter 40 but staying with it spaced is abundant flat grid, is fixed with trapping medium 70 (being substrate or hybrid radix) on it.Air can aspirate by grid.Described trapping medium 70 moves around the cylinder 71 and 72 that is fixed on grid 60 two ends.Use suitable electrostatic potential source 61 and be connected to grid 60 and transmitter 40 on line 62 and 63, 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 rotations, now liquid leaves hole 44 or extracts out from storage tank, from the outer rim of transmitter, to the trapping medium 70 being fixed on grid 60, moves.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 of extracting out to grid 60, is collected on base material 12 or effective layer 14.For the polymer in solution, when they fly to grid 60, the solvent evaporation on fiber is removed.First the fine fibre being bonded on basilar fibers encounters grid 60.Select electrostatic field intensity to guarantee that its acceleration is enough to make polymeric material to form very thin micrometer fibers or nanofibrous structures when polymeric material accelerates from transmitter to trapping medium 70.The speed that raising or reduction trapping medium move can deposit more or less fiber on formation medium, controls thus the thickness of each thin layer of deposition on it.Described rotary part 42 can have various useful positions.Described rotary part 42 can be placed on the surfaces of revolution vertical with 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 for form the schematic diagram of the apparatus and method of fine fiber layer on 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, here for carrying out line operation, is joined together at the bottom of by many segment bases.The sheet form base of the continuous length fine fibre process unit 22 that leads again, comprising the process unit that reels off raw silk from cocoons of Fig. 1, this spinning unit forms fine fibre and fine fibre is deposited on and in sheet form base, forms filter course.When form fine fiber layer in sheet form base in formation region 22 after, fine fiber layer and substrate-guided annealing device 23 carry out suitable processing.Then in efficiency monitoring device 24, test sheet form base and fine fiber layer, and if if required, in planishing device 25, planish.Then the suitable coiler device that sheet form base and fine fiber layer led, will reel on wherein suitable spindle for further processing 26 and 27.

Fig. 3 shows that diameter is about the typical dust granule of 2 and 5 microns and scanning electron microscope diagram in typical fibers medium and typical fine fiber structure mesopore size relativity.In Fig. 3 A, shown at hole and be obviously greater than 2 micron particles 31 and 5 micron particles 32 in the fiber medium 33 of typical particle diameter.In Fig. 3 B, form sharp contrast, 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.

Above the useful filtration of polymeric material of the present invention, the fine fibre material that the present invention includes micrometer fibers and nanofiber and fine fibre material of the present invention is manufactured the general remark of each side, the understanding that the present invention is operated to general technology principle is provided.The concrete exemplary materials of the following stated is the examples of materials that can be used for manufacturing fine fibre material of the present invention, and following material has disclosed best pattern.Manufactured these exemplary materials, use be following characteristic and operating condition.Use the electrostatic field of improving oneself to play the electrostatic force of pull effect, polymeric spray thing is pulled into very thin filament, obtain static that diameter the is less than 10 microns fiber that reels off raw silk from cocoons.Although in static drawing process, can use polymer melt,, the most handy polymer solution makes the fiber that is narrower than 1 rice.When polymer forms more minor diameter, solvent evaporates and is conducive to fall 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 large.If solvent is dry too slowly, solvent is lysigenous fiber again.Therefore rate of drying and fibroplastic cooperation are very crucial.When high production rate, a large amount of discharge air can prevent imflammable gas and reduce 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.Static reels off raw silk from cocoons and can under 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 these conditions of relative humidity of 45%, operate.

The selection of polymer system is very important concerning given purposes.For adopting pulse to purify, micrometer fibers layer as thin as a wafer contributes at the outer surface that makes can provide in the very little situation of the pressure loss particle capture and release.Preferably use diameter to be less than 2 microns, should be less than the fibre thin layer of 0.3 micron.Between micrometer fibers or nanofiber and its deposition substrate, good tack is very important.When the compound consisting of substrate and micrometer fibers and nanofiber when filter makes, this compound can be applicable to the good filter medium of auto purification.By repetition pulse dorsad, purify described surface and just upgraded filter medium.When applying large active force from the teeth outwards, in substrate the fine fibre of poor adhesion because delamination appears in pulse dorsad, described pulse dorsad from filter interior by the substrate micrometer fibers of flowing through.Therefore, good adhere to and the successful purposes of adhering to that basilar fibers and static reel off raw silk from cocoons between fiber is very important between micrometer fibers.

Use the fiber that various polymeric materials make can obtain the product that adapts to above-mentioned requirements.The fine fibre with good adherence performance can and contain various nylon by for example polyvinylidene chloride, polyvinyl alcohol and make as the polymer of nylon 6, nylon 4,6, nylon 6,6, nylon 6,10 and copolymer and their copolymer.Can make good fiber by PVDF, but manufacturing the fiber that diameter is enough little needs chlorinated solvent.Nylon 6, nylon 66 and nylon 6,10 can carry out static and reel off raw silk from cocoons.But for example 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 done research widely.We have found that, the fiber being made by PVC, PVDC, polystyrene, polyacrylonitrile, PMMA, PVDF need to obtain structural behaviour by extra adhesive bonding method.We also find when polymer is water-soluble, ethanol, isopropyl alcohol, acetone, methyl alcohol and their mixture while successfully making fiber, and they have good adhesion property to substrate, can make thus the good filter that is suitable for auto purification.When filter is during for high dust concentration very, by air carry on the back pulse auto purification or stranded be useful.By dissolving in the polyamide of alcohol and fiber that polyvinyl alcohol makes, successfully use in this purposes.The polyamide example that dissolves in alcohol comprises the Macromelt6238,6239 and 6900 buying from Henkle; The Elvamide8061 buying from duPont and 8063 and the SVP637 and 651 that buys from Shakespear monofilament Company.Other one group of polyamide that dissolves in alcohol is 8 type nylon, alkoxyalkyl modification of nylon 66 (with reference to Nylon Plastichandbook, the 447th page, melvin Kohan etc., hanser Publisher, New York, 1995).Polyvinyl alcohol example comprises from Kuraray, the PVA-217 that Japan buys, 224 and the Vinol540 that buys from Air Products andChemical Company.

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

experiment

Use following static drawing process condition to produce following material.

Use revolving expeller system or capillary needle system to reel off raw silk from cocoons and make following material.These two kinds of systems all can be produced essentially 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 " determining of nylon molecular weight ", chemistry annual report Vol.19, Number7,448-450 page (1947)) analyze the molecular weight of the fine fibre sample that b prepared by nylon 6,66,610 nylon multipolymer resins (SVP-651).Number-average molecular weight is 21,500-24,800.The melt temperature phasor of yynw composition by three kinds of component nylon such as approximately 45% nylon 6, approximately 20% nylon 66 and approximately 25% NYLON610 (people's work " nylon plastics handbook " the 286th page such as Melvin Kohan, Hanser publishing house, New York (1995)) evaluate.The physical property of the SVP651 resin of report is:

Character	ASTM method	Unit	Representative value
				Proportion	D-792		1.08
Water imbibition (24 hours dippings)	D-570	％	2.5
				Hardness	D-240	Shore D	65
Fusing point	DSC	℃(℉)	154(309)
				TENSILE STRENGTH@surrender	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	1012

Be used for producing diameter and be the fiber of 0.23 and 0.45 micron.Sample is immersed in the water of room temperature, air-dry and measure its efficiency.Thicker fiber need to be longer time degraded, and palliating degradation degree is lower, as shown in the curve in Figure 12.Although do not wish to be subject to the restriction of particular theory, look have compared with high surface/volume compared with fine fibre more easily because the impact of environment is degraded., 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, tested the chemical crosslinking of nylon fiber.With the phenolic resins that is called Georgia Pacific5137, mix aforesaid copolyamide (nylon 6,66,610) and be pumped into fiber.The when melt temperature of their mixture of nylon and phenolic resins is expressed as follows:

Form	Melt temperature (℉)
		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 can not be cross-linked by heating, because can destroy fibre structure.The chemical resistance that has improved gained fiber at 90 ℃ of following heating mixture of 65: 35 for 12 hours, suppresses its dissolving in alcohol.Can use the mixture of polyamide and epoxy resin, as derive from the Epon828 of Shell and Epi-Rez510.

embodiment 3: use fluorochemical additive

the surface modification of waterproofing agent

Before reeling off raw silk from cocoons, to having added in polyamide, to derive from the alcohol of 3M company solvable

fC-430 and 431.Addition is 10% of solid.Scotchgard adds the formation that does not hinder fiber.The high molecular waterproofing agent that THC platform shows similar Scotchgard finally can not improve water proofing property.As manufacturing firm is advised, the Scotchgard sample adding has been heated 10 minutes at 300 ℉.

embodiment 4: with the modification of coupling agent

Polymer film carrys out castable by polyamide together with the titanate coupling agent that derives 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 (LICA12), 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 immediately intensity, and added the sample of coupling agent to maintain its profile until 10 minutes.These add the sample of coupling agent to be pumped into fiber (fiber of 0.2 micron).

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

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

We find that this group additive has prevented that fine fibre is subject to the impact of wet environment, as shown in curve.Figure 13-16 show oligomer and provide extraordinary protection under 140 ℉, 100% humidity, but the performance when 160 ℉ is not very good.We have added this additive of the polymer 5-15% that uses.Find that they are effectively same to protection fiber when 140 ℉ are exposed under high humility.We also find to stand after a bit of time at 150 ℃ when fiber, and their performance increases.

The impact of the temperature and time that table 1 shows exposure on the polyamide fiber that contains 10% additive.

The conservation rate of efficiency after table 1.140 ℉ soaks

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

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

Just start, the surface concentration of having found additive is that what meaning is the twice of bulk concentration seem not have., we think that this can explain by the molecular weight of additive.Be about the polymer that the molecular weight of 600 additive forms much smaller than principal fiber.Because their size is less, they can move on the solvent molecule evaporating.Like this, we just can realize the high surfaces concentration of additive.Further process the surface concentration that has increased protective additive., at 150 ℃, expose and within 10 minutes, can not make concentration increase.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 was told us is suitably to select the time of post processing and temperature can improve performance, and processes the impact that the oversize time has reverse side.

We use the technology that is called Time of Flight (ToF) SIMS further to check the micrometer fibers that has added these additives.This technology is to bombard object with electronics, and observation has anything to come from surface.The sample that does not contain additive shows when bombarding with electronics has organic nitrogen material out.This shows that fracture has occurred polyamide materials.This result has also shown a small amount of impurity, as the existence of sodium and silicon.The sample that contains additive but do not heat-treat (lip-deep additive concentration is 23%) shows section main matter at the bottom of the tert-butyl group, and observes the little of polyamide and peak clearly.Also observe simultaneously relative with tert-butyl phenol of poor quality be the high-quality peak of 148amu.To the sample (learning that by esca analysis surface additive concentration is 50%) of having processed 10 minutes at 150 ℃, check.At the bottom of showing the tert-butyl group, section is occupied an leading position, and has faint polyamide peak, if really had, checks there is no to show the peak relevant to whole tert-butyl phenol and polymer thereof.Check and also show and C ₂h ₃the peak that O fragment is relevant.

The demonstration of ToF sims analysis, this can emit nitrogen fragment and the lip-deep pollutant rupturing on the polymer chain of exposure polyamide fiber when being subject to bombardment by ions.Added additive but do not heat-treated, having covered not exclusively, having shown that additive does not cover in some part of surface.When this surface of ion beam strikes, complete molecule can be emitted together with section at the bottom of the unsettled tert-butyl group.If added additive and carried out heat treatment, just impelled and shown to cover completely.In addition, molecule is closely aligned and makes only to have unsettled fragment as the tert-butyl group, and may be that CH=CH-OH emits, and the whole molecule of tert-butyl phenol is not emitted.ESCA and ToF SIMS check at surperficial different depth place.The compare Shen 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-coated copolymer

The nylon of development types 8 is for for the preparation of coating with adhere to the solvable crosslinkable resin of purposes originally.This base polymer be under the condition existing in acid polyamide 66 react with formaldehyde and alcohol make (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 static., this polymer forms fiber and is inferior to copolyamide, and is crosslinkedly difficult for carrying out.

In order to prepare the nylon of type 8, reinforced in the high-pressure reactor of 10 gallons of following ratio fillings:

10 pounds of nylon 66 (duPont Zytel)

15.1 pounds of methyl alcohol

2.0 pounds, water

12.0 pounds, formaldehyde

Then, under pressure with this reactor of nitrogen wash and be heated at least 135 ℃.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 is carried out 30 minutes.In this stage, formed viscosity homopolymers solution.After the reaction time of regulation, the material in high-pressure bottle is transferred to and contained methyl alcohol, water and alkali as made to react 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 alkoxyalkyl modification type 8 forming is like this dissolved in the mixture of ethanol/water.This polymer solution carries out static by the method that is described in Barris U.S. Patent No. 4,650,516 and reels off raw silk from cocoons.The viscosity of polymer solution increases in time.Conventionally known polymer viscosity is to determining that fiber size has important effect.So just be difficult to control commercial size quantity-produced process.In addition,, under identical condition, type 8 polyamide can not effectively form micrometer fibers as copolyamide.; when prepared by solution, added acid catalyst; as toluenesulfonic acid, maleic anhydride, trifluoromethayl sulfonic acid, citric acid, ascorbic acid etc., and after fibre forming, mat of fibers is carried out to carefully heat treatment, the fiber of gained has extraordinary chemical resistance (Figure 13).At cross-linking stage, must carefully, not destroy fibre structure.

When type 8 polyamide (polyamide B) mix with the solvable copolyamide of alcohol, we have found an astonishing result.With the solvable copolyamide of alcohol, as the polyamide 66 that SVP637 or 651 (polyamide A), Elvamide8061 substitute the alkoxyalkyl modification of 30 % by weight, found cooperative effect.The fibre forming of mixture is more effective than any independent component.Be immersed in ethanol and measure filter efficiency and shown the filter efficiency conservation rate that is greater than 98%, THC bench teat test show polyamide-based with independent type 8 like result.Such mixture shows, we can obtain the advantage of effective fibre forming and the fabulous filtering feature of copolyamide, and the fabulous chemical-resistant advantage of crosslinked type 8 polyamide.It is crosslinked that alcohol soak test has shown that non-crosslinked copolyamide has participated in consumingly, kept 98% filter efficiency.

Mixture at polymer A and B is heated to 250 ℃ (full cross-linked) afterwards, and their DSC (referring to Figure 17-20) becomes and is difficult to distinguish with independent polymer A, there is no diacritic melt temperature.This has shown that the mixture of polymer A and B is now the complete polymer being cross-linked to form by polymer B and polymer A consumingly.

Similarly, the molten mixture of polyethylene terephthalate and polybutylene terephthalate has similar character.In temperature, carry out in the process of melting operation under higher than the melt temperature of each component, the copolymer that ether group exchanged and formed PET and PBT occurs.And our crosslinking temperature is lower than arbitrary independent component.Can not expect that this base exchange occurs at low temperatures.Therefore, the solution of the polyamide by type A and type B mixes and is crosslinked during lower than the fusing point of each component in temperature, and we have be sure of to find the new polyamide of a class.

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 has participated in and the reacting of the functional group of the nylon of type 8.We find that this component system provides good fibre forming, have improved prolonged property and the hydrophobicity to fine fiber layer surface to high temperature and high humidity.

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 have formed fiber by the static method of reeling off raw silk from cocoons, and at 300 ℉, mat of fibers are exposed to 10 minutes and have measured 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 of relevant surface composition.It can provide the information of carbon, nitrogen and oxygen.Because additive 7 is nonnitrogenous, we can estimate by comparing the concentration of nitrogen the ratio of nitrogenous polyamide and unazotized additive.Other qualitative information can obtain by detecting the O1s power spectrum in conjunction with energy between 535-527eV.The combination of C=O key can be 531eV left and right, and the combination of C-O key can be 533eV.By the peak height at Zhe Liangge peak relatively, can estimate with the polyamide of main C=O and only with the relative concentration of the additive of C-O group.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 has positively occurred, because demonstrate the relative minimizing (Fig. 4 is the polymer A of not heat-treating and the mixture of fibers of polymer B, and Fig. 5 is the mixture of fibers of having carried out heat treated polymer A and polymer B) of C-O key.Minute period of the day from 11 p.m. to 1 a.m that has additive 7 on surface, can expect to have more C-O key.Situation is like this really, by Fig. 6 and 7 visible (Fig. 6 is the mixture of fibers that polymer A, polymer B and additive 7 are pumped into, and Fig. 7 is that polymer A, polymer B and additive 7 have 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 approximately 50 hydrophobic coating.The nylon of type 8 has functional group as-CH ₂oH and-CH ₂oCH ₃, we expect their can with tert-butyl phenol-OH functional group reactions.Like this, just can be desirably in and on fiber surface, see less oligomer molecules.The hypothesis that found that us is incorrect, and the surface of copolymer has a thin coating.

Sample 6A, 6B and be described in the 5th joint repeat sample under 100%RH condition, be exposed on 160 ℉ THC platforms.In prosthomere, sample is exposed under 140 ℉ and 100%RH.Under these conditions, tert-butyl phenol has prevented the degraded of trimer copolyamide., if temperature is elevated to 160 ℉ and 100%RH, the ability of tert-butyl phenol oligomer protection trimer copolyamide is below not good.We have compared these samples at 160 ℉ and 100%RH.

Table 4: the conservation rate of fine fibre efficiency after being exposed under 160 ℉ 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 table shows that sample 6B contributes to prevent the impact of high temperature and high humidity.

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

The repeat sample of sample 6A, 6B and the 5th band is placed in to the stove that Temperature Setting is 310 ℉.Following table shows, it is complete that sample 6A and 6b keep, and the sample of the 5th joint seriously damages.

Table 5: the retention rate that is exposed to fine fibre efficiency after 310 ℉

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

Although add separately the heat-resisting quantity that the oligomer of polymer A has improved fine fiber layer, and adding of additive 7 do not have any effect to being exposed to high temperature.

We clearly illustrate that; the nylon 66 of trimer copolyamide, alkoxyalkyl modification and the mixture of tert-butyl phenol oligomer can provide the quality product of protecting fine fibre under rugged environment, can improve productive rate when manufacturing the mixture of trimer copolyamide and the mixture of tert-butyl phenol oligomer or the nylon 66 of trimer copolyamide and alkoxyalkyl modification 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 can be prepared (Pecora, A by the oxidative coupling of phenol ring; Cyrus, the United States Patent (USP) 4,900 of W., 671 (1990) and Peroca, A; Cyrus, W.; Johnson, the United States Patent (USP) 5,153 of M., 298 (1992)).Wherein, the attractive especially polymer being made by the bisphenol-A purchased from Enzymol company.The oxidation of the soybean peroxidase catalysis of bisphenol-A can start by the either side of two-OH group from bisphenol-A.Be that Merlon is different from linear bisphenol-A, 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 the 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 poly-parameter handbook in other " the 317th page, people's works such as A.Barton).If calculate solubility parameter (" solubility parameter handbook " the 61st page), the solubility parameter value calculating 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.

In ethanolic solution, make the bisphenol a resin of molecular weight 3,000 and the mixture of copolyamide of 50: 50.Total concentration in ethanolic solution is 10%.With copolyamide, can produce separately the fiber of 0.2 micron of diameter.And this mixture forms the soft layer of the fiber of approximately 1 micron.The bisphenol-A of molecular weight 7,000 is unstable together with copolyamide time, easily precipitation.

On the DSC of 50: 50 mixtures, do not see melt temperature.The melt temperature of copolyamide is 150 ℃ of left and right, and bisphenol a resin is the nature of glass polymer of Tg approximately 100.And this mixture of these two kinds of materials does not have obvious melting phenomenon.When fiber mat is exposed to 100 ℃, 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 that is solution form plays similar solvent, and the polymer that is solid form plays solid effect.We find that this double action of bisphenol-A is real unique.

Make following formula:

The PA66 of alkoxyalkyl modification: 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%.The solution that contains the mixture of 19.2% polymer B, its viscosity surpasses 200 centipoises.The viscosity that singly has 12% polymer B in similar solvent is in 60 centipoises left and right.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 separately fibre forming, the fiber size of expection 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 any other example of unique double action like this.After sample immerses in ethanol, measure filter efficiency and fiber size.After alcohol soaks, 85.6% filter efficiency and fiber size have been retained constant.It is crosslinked that this shows that polymer C has participated in, and plays the effect of similar polymer solids.

Another polymer solution is prepared by following formula:

The PA66 of alkoxyalkyl modification: polymer B 225g

Bisphenol a resin (molecular weight 3,000): polymer C135g

190 ° of rank ethanol 778g

Acetone 205g

DI water 15.7g

Catalyst 11.6g

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

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

Resin, alcohol and water are mixed, at 60 ℃, stir and within 2 hours, prepared different samples.Solution is cooled to room temperature and adds wherein catalyst, then stir this mixture 15 minutes.Subsequently, measure the viscosity of solution and be pumped into fiber.

Following table shows 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, compare with the formula of polymer A, and the fiber quality of generation is more than 50%.In addition, the polymer microfibers of gained chemical resistance more.After soaking in alcohol, even if intrinsic crosslinked polymer is only 44% of solid composite, the filter being made by these fibers keeps being greater than 90% filter efficiency and keeping fibre diameter constant.The nylon 66 of this copolyamide, alkoxyalkyl modification and the terpolymer composition of bisphenol-A have generated fibre forming performance again chemical-resistant material.

embodiment 10: the copolymer of the alkoxyalkyl modification of nylon 66 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, by polymer solution quenching, precipitation, cleaning dry.

The DSC of the polymer making with nylon 46 and nylon 66 has shown wide single melt temperature, and it is lower than the melt temperature of the nylon 46 (241 ℃) of modification or the nylon 66 (210 ℃) of modification.This shows in course of reaction, and two kinds of components can distribute randomly along polymer chain.Like this, we think and have obtained with the nylon 46 of alkoxyalkyl modification and the random copolymer of nylon 66.These polymer may be dissolved in the mixture of alcohol and alcohol and water.

Character	ASTM	Nylon 6.6	Nylon 4.6
				Tm		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 be all high crystallization and be insoluble in common alcohol.

Source: contemporary plastics encyclopedia 1998

embodiment 11: the reel off raw silk from cocoons formation of fiber of the exploitation of the copolymer of copolyamide and alkoxy-modified nylon 46/66 copolymer and static

Use said method that the sample of polymer 10B and 10D (seeing the following form) is made to fiber.With nylon 46/66 (polymer D) of alkoxyalkyl modification, successfully having carried out static separately reels off raw silk from cocoons.Polymer D can produce following extra benefit with mixing of polymer A: more effective fibre forming and make crude fibre more and not containing the bridging property of sacrificial polymer D, as shown in the table:

the total length of the mass ratio of fiber by fiber is multiplied by sectional area and calculates.The conservation rate of filter efficiency is by immersing fiber sample in ethanol and measure.After soaking in alcohol, fiber size is constant.

embodiment 12: the static 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 static reels off raw silk from cocoons, make itself and crosslinking agent and toluenesulfonic acid catalyst mix.Before being exposed to THC platform, the stove that the fiber mat of gained is placed in to 150 ℃ 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 ℉, humidity 100%

(b): temperature 140 ℉, humidity 100%

(c): molecular weight 2000

(d): the melamine formaldehyde resin that derives 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 hydraulic pressure is 16 feet per minute clocks, and thickness is 0.012 inch, and LEFS efficiency is 41.6%.Use the fine fiber layer that described method is 0.2 micron by the nominal fibre diameter of embodiment 1 to be added on substrate surface.The LEFS efficiency of gained compound is 63.7%, and the air that under 100% relative humidity, the sample of just substrate is exposed to 140F, after 1 hour, makes sample cooling and dry, and its LEFS efficiency is 36.5%.Compound is exposed to the air of 140F under 100% relative humidity after 1 hour, makes sample cooling and dry, its LEFS efficiency is 39.7%.Use described mathematical formulae to calculate, the efficiency that obtains exposing the fine fiber layer retaining after 1 hour is 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 hydraulic pressure is 16 feet per minute clocks, and thickness is 0.012 inch, and LEFS efficiency is 41.6%.Use the fine fiber layer that described method is 0.2 micron by the nominal fibre diameter of embodiment 5 to be added on surface.The LEFS efficiency of gained compound is 96.0%.Under 100% relative humidity, the sample of just substrate is exposed in the air of 160F after 3 hours, makes sample cooling and dry, its LEFS efficiency is 35.3%.Compound is exposed to the air of 160F under 100% relative humidity after 3 hours, makes sample cooling and dry, its LEFS efficiency is 68.0%.Use described mathematical formulae to calculate, the efficiency that obtains exposing the fine fiber layer retaining after 3 hours is 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 hydraulic pressure is 16 feet per minute clocks, and thickness is 0.012 inch, and LEFS efficiency is 41.6%.Use the fine fiber layer that described method is the mixture of the polymer A of 0.2 micron and polymer B by the nominal fibre diameter described in embodiment 6 to be added on surface.The LEFS efficiency of gained compound is 92.9%.Under 100% relative humidity, the sample of just substrate is exposed in the air of 160F after 3 hours, makes sample cooling and dry, its LEFS efficiency is 35.3%.Under 100% relative humidity, compound is exposed in the air of 160F after 3 hours, makes sample cooling and dry, its LEFS efficiency is 86.0%.Use described mathematical formulae to calculate, the efficiency that obtains exposing the fine fiber layer retaining after 3 hours is 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 hydraulic pressure is 16 feet per minute clocks, and thickness is 0.012 inch, and LEFS efficiency is 41.6%.Using described method is that the fine fiber layer of mixture of polymer A, polymer B and the tert-butyl phenol oligomer of 0.2 micron is added on surface by the nominal fibre diameter described in embodiment 6.The LEFS efficiency of the compound of gained is 90.4%.Under 100% relative humidity, the sample of just substrate is exposed in the air of 160F after 3 hours, makes sample cooling and dry, its LEFS efficiency is 35.3%.Under 100% relative humidity, compound is exposed in the air of 160F after 3 hours, makes sample cooling and dry, its LEFS efficiency is 87.3%.Use described mathematical formulae to calculate, the efficiency that obtains exposing the fine fiber layer retaining after 3 hours is 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 hydraulic pressure is 16 feet per minute clocks, and thickness is 0.012 inch, and LEFS efficiency is 41.6%.Use the fine fiber layer with polyacrylic crosslinked PVA that described method is 0.2 micron by the nominal fibre diameter of embodiment 12 to be added on surface.The LEFS efficiency of the compound of gained is 92.9%.Under 100% relative humidity, the sample of just substrate is exposed in the air of 160F after 2 hours, makes sample cooling and dry, its LEFS efficiency is 35.3%.Under 100% relative humidity, compound is exposed in the air of 160F after 2 hours, makes sample cooling and dry, its LEFS efficiency is 83.1%.Use described mathematical formulae to calculate, the efficiency that obtains exposing the fine fiber layer retaining after 3 hours is 89%, and the effective fine fibre number of reservation is 76%.

embodiment 18

By the method described in embodiment 1-17, make following filter medium.

test method

hot-water soak test

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

It is that the medium of several square inches is made an appraisal that-filtration is measured, and this can only observe zonule (being conventionally less than 0.0001 square inch) than SEM microphotograph can draw better mean value.

-filter to measure and can determine the fibre number that keeps filtration in structure.Though those retain, but in groups in conjunction with or the fiber that otherwise exists in the structure changing be just presented in the efficiency and function recording.

However, in the fibre structure that is difficult for recording in filter efficiency, still can with respect to 50% retention criteria, evaluate with the fiber percentage that other method is measured reservation.

Illustrate:

This test means the accelerated test of filter medium WATER RESISTANCE.The performance variation of water-immersed filter medium is measured in this test with LEFS testing stand.Water temperature is conclusive parameter, and the durability experience result of the medium obtaining according to research institute reduces to minimum needs and test by test period and distinguishes the ability of media type and select water temperature.General water temperature is 70 ℉, 140 ℉ or 160 ℉.

Program:

From medium, cut the next 4 " samples of diameter.Use the latex balloon of 0.8 μ m as the test pollutant in the LEFS operating under 20FPM condition (about the description of LEFS test, referring to ASTM standard F1215-89) platform, calculate the particle capture efficiency of sample.Then, sample is immersed in (being generally 140 ℉) distilled water to 5 minutes.Sample is placed in and on 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.The substrate (but there is no fine fibre in the above) of fine fibre being supported to use repeats previous step.

The final loss in efficiency that only can calculate the efficiency composition that causes due to fine fibre and cause due to the destruction of water by the above results.Determined after the loss in efficiency causing due to fine fibre, can calculate the amount of the efficiency of reservation.

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 _x=fine fiber layer efficiency after soaking;

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 of efficiency > 50%

In the purposes of most industry pulse polishing filter, if fine fibre efficiency has retained at least 50%, this filter is enough to work.

tHC platform (temperature, humidity)

Illustrate:

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

Temperature-31 are to 390 ℉

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

Be 16 hours the longest continuous time under condition)

Flow velocity 1-35FPM

Program:

From medium, cut off the one 4 " sample of diameter.

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

Test period can, from a few minutes by several days, 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.

Fine fibre support base (there is no fine fibre above) is repeated to previous step tests.

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

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

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

In the purposes of most industry pulse polishing filter, if fine fibre efficiency has retained at least 50%, this filter is enough to work.

alcohol (ethanol) soak test

Illustrate:

This test is used LEFS testing stand to measure the variation of the filtering medium property in the ethanol that is immersed in room temperature.

Program:

From medium, cut off the one 4 " sample of diameter.Use the latex balloon of 0.8 μ m as the test pollutant in the LEFS platform operating under 20FPM condition, the particle capture efficiency of test sample.Then, sample is immersed in alcohol to 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.Fine fibre support base (there is no fine fibre above) is repeated to previous step tests.By above-mentioned test result, only can calculate the efficiency composition that causes due to fine fibre and due to the final loss in efficiency that soaks the destruction of alcohol and cause.Determine the loss in efficiency of fine fibre, can calculate the amount of the efficiency of reservation.

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

Above-mentioned explanation, embodiment and data are set forth the present invention.But, to described the present invention, can make many variations and embodiment.The present invention is embodied in the accompanying claims of this paper.

Claims (32)

1. a fine fibre, described fine fibre comprises the additive of addition polymer and 2-25 % by weight, and described additive comprises that molecular weight is 500-3000 and the resin-like material with armaticity, and described additive is miscible in described polymer; The diameter of described fiber is 0.1-0.5 micron, in the air of 140 °F and 100% humidity, expose after 3 hours, at least 30% fiber remains unchanged to filter substantially, and described addition polymer is selected from polyolefin, polyvinyl chloride, polymethyl methacrylate, polystyrene and their copolymer, polyvinylidene fluoride, the sub-ethene of poly-dichloro and polyvinyl alcohol.

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 addition polymer comprises polyvinyl alcohol.

4. fine fibre as claimed in claim 1, is characterized in that described fiber comprises the product of polyvinyl alcohol and crosslinking agent, and the amount of described crosslinking agent is counted 1-40 % by weight with described polyvinyl alcohol polymer.

5. fine fibre as claimed in claim 4, is characterized in that described crosslinking agent comprises melamino-formaldehyde resin.

6. fine fibre as claimed in claim 1, is characterized in that described additive is to be positioned at the lip-deep hydrophobic coating of fine fibre.

7. fine fibre as claimed in claim 6, is characterized in that the thickness of described coating is less than

8. fine fibre as claimed in claim 4, is characterized in that described crosslinking agent comprises homopolymers and acid catalyst, and described homopolymers comprises acrylic acid and molecular weight is 1000-5000.

9. fine fibre as claimed in claim 1, is characterized in that described fine fibre comprises the product of addition polymer and crosslinking agent.

10. fine fibre as claimed in claim 1, is characterized in that when exposing in 140 °F, the air stream of relative humidity 100%, is greater than 50% fiber survival over 16 hours.

11. fine fibres as claimed in claim 1, is characterized in that described fine fibre comprises the fiber containing the product of polyvinyl alcohol polymer and crosslinking agent.

12. fine fibres as claimed in claim 4, is characterized in that described polyvinyl alcohol complete hydrolysis.

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

14. fine fibres as claimed in claim 1, is characterized in that described addition polymer comprises polyethylene.

15. fine fibres as claimed in claim 1, is characterized in that described addition polymer comprises polypropylene.

16. 1 kinds of fine fiber layer that comprise fiber, described fiber comprises the additive of addition polymer and 2-25 % by weight, and described additive comprises that molecular weight is 500-3000 and the resin-like material with armaticity, and described additive is miscible in described polymer; Described layer comprises the fiber of random, the diameter of described fiber is 0.1-0.5 micron, in the air of 140 °F and 100% humidity, expose after 3 hours, at least 30% fiber remains unchanged to filter substantially, and described addition polymer is selected from polyolefin, polyvinyl chloride, polymethyl methacrylate, polystyrene and their copolymer, polyvinylidene fluoride, the sub-ethene of poly-dichloro and polyvinyl alcohol.

17. fine fiber layer as claimed in claim 16, is characterized in that described resin-like additive comprises the oligomer containing dihydroxybiphenyl base.

18. fine fiber layer as claimed in claim 16, is characterized in that described addition polymer comprises polyvinyl alcohol.

19. fine fiber layer as claimed in claim 16, is characterized in that described fiber comprises the product of polyvinyl alcohol and crosslinking agent, and the amount of described crosslinking agent is counted 1-40 % by weight with described polyvinyl alcohol polymer.

20. fine fiber layer as claimed in claim 19, is characterized in that described crosslinking agent comprises melamino-formaldehyde resin.

21. fine fiber layer as claimed in claim 16, is characterized in that described additive is to be positioned at the lip-deep hydrophobic coating of fine fibre.

22. fine fiber layer as claimed in claim 21, is characterized in that the thickness of described coating is less than

23. fine fiber layer as claimed in claim 19, is characterized in that described crosslinking agent comprises homopolymers and acid catalyst, and described homopolymers comprises acrylic acid and molecular weight is 1000-5000.

24. fine fiber layer as claimed in claim 16, is characterized in that described fine fibre comprises the product of addition polymer and crosslinking agent.

25. fine fiber layer as claimed in claim 16, is characterized in that when exposing in 140 °F, the air stream of relative humidity 100%, are greater than 50% fiber survival over 16 hours.

26. fine fiber layer as claimed in claim 16, is characterized in that described fine fiber layer comprises fiber, and described fiber comprises the product of addition polymer and crosslinking agent, and described layer comprises the fine fibre of the formation intersection fabric of random.

27. fine fiber layer as claimed in claim 16, is characterized in that described addition polymer is the polyvinyl alcohol of complete hydrolysis.

28. fine fiber layer as claimed in claim 16, is characterized in that described additive comprises at least one that is selected from following component: the oligomer that comprises tert-butyl phenol, the oligomer that comprises bisphenol-A, the oligomer that comprises dihydroxybiphenyl base and fluorochemical.

29. fine fiber layer as claimed in claim 16, the 1-100 that the thickness that it is characterized in that described layer is described fibre diameter doubly.

30. fine fiber layer as claimed in claim 29, is characterized in that described layer thickness is 1-8 times of described fibre diameter.

31. fine fibres as claimed in claim 16, is characterized in that described addition polymer comprises polyethylene.

32. fine fibres as claimed in claim 16, is characterized in that described addition polymer comprises polypropylene.

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