CN101374894A - Hydrophilic composite microporous membrane and method for producing same - Google Patents

Abstract

Disclosed is a hydrophilic composite microporous membrane having an anion-exchange group and a cation-exchange group on either the surface or the inner surfaces of the micropores of a thermoplastic resin microporous membrane base. The hydrophilic composite microporous membrane is excellent in water permeability, mechanical strength, particle removal capability, anion removal capability and cation removal capability.

Description

Hydrophilic composite microporous membrane and manufacture method thereof

Technical field

The present invention relates to hydrophilic composite microporous membrane and manufacture method thereof, particularly have the hydrophilic composite microporous membrane and the manufacture method thereof of anion exchange groups and cation exchange group.

Background technology

Clean in the ultrapure water manufacturing system use etc. at semi-conductor,, use osmosis filtration film, ultra-filtration membrane, secondary filter film etc. in order to remove impurity.Generally speaking, the ultrapure water manufacturing system is made of preprocessing system, primary pure water system and second pure water system (subsystem).In the preprocessing system,, remove suspended matter or colloidalmaterial in anhydrating by flocculation sediment, secondary filter, ultrafiltration etc.The water that has carried out pre-treatment is fed in the primary pure water system that possesses reverse osmosis membrane separation device, ion exchange unit, de-gassing vessel etc., removes most ion component and total organic carbon (TOC).Be fed to the water in the subsystem, micro-TOC oxygenolysis in ultraviolet oxidation unit is removed this decomposition composition in ion exchange unit, and the micro particles composition that is not removed in ion exchange unit is removed in the ultra-filtration membrane tripping device.

Like this ultrapure water of Zhi Zaoing be fed to the cleaning of carrying out semi-conductor etc. with in the water spot.But in recent years along with semi-conductive integrated level rapidly improves, the dimension of picture microminiaturization can not be ignored small pollution, the pipe arrangement from subsystem to the usefulness water spot and the small pollution the equipment in subsystem.So, proposed before with water spot, to remove micro-ion component and particulate composition.

For example, Japanese kokai publication hei 8-89954 number proposition has: the module that will be filled with the hollow fiber micro-porous film is arranged on the modular system before the water spot, and described micro-porous film forms the macromolecular chain with ion-exchange group.But the hollow fiber micro-porous film of the document only has anion exchange groups, cation exchange group or inner complex and forms in the group any as ion-exchange group.Be denier with the impurity in the water spot, but its particular difficulties, therefore,, also may not removing whole impurity even use the modular system of Japanese kokai publication hei 8-89954 number.

Therefore, Japanese kokai publication hei 9-141262 number a kind of filter system has been proposed, the composition that its cooperation will be removed, contain film, cation group from anion exchange groups and contain film, inner complex cation exchange groups and contain and suit film and the ultra-filtration membrane to select, be arranged on before the water spot being filled with the module of independent film, the module that is filled with the module of stacked film or the is filled with independent film module that forms that is connected in series.

But, in particular difficulties with the impurity before the water spot.The filter system that the use Japanese kokai publication hei is 9-141262 number in order to remove all impurity, needs to use the module of the duplexer that is filled with above-mentioned whole films, perhaps will be filled with a plurality of connection of module of independent film.Thus, the problem that exists water-permeable to reduce significantly.In order to deal with this problem, have the method for using again boosting pump, but owing to produce once more and pollute, therefore not preferred.

Summary of the invention

Therefore, the object of the present invention is to provide water-permeable, physical strength, particulate to remove ability, negatively charged ion and remove hydrophilic composite microporous membrane and the manufacture method thereof that ability and positively charged ion are removed the ability excellence.

The inventor carries out extensive and deep research in view of above-mentioned purpose, found that: if on arbitrary surface of the surface of thermoplastic resin micro-porous film system base material and pore internal surface, introduce anion exchange groups and cation exchange group, obtain then that water-permeable, physical strength, particulate are removed ability, negatively charged ion removes ability and positively charged ion is removed the hydrophilic composite microporous membrane of ability excellence, thereby finish the present invention.

That is, hydrophilic composite microporous membrane of the present invention is characterized in that, has anion exchange groups and cation exchange group on any of the surface of thermoplastic resin micro-porous film system base material and pore internal surface.

As above-mentioned anion exchange groups, be preferably the amino in primary～season and in the assorted cyclic amine residue any, more preferably season amino.As above-mentioned cation exchange group, be preferably in sulfonic group and the carboxyl any.

The manufacture method of first hydrophilic composite microporous membrane of the present invention, it is characterized in that, after making unsaturated glycidyl compound carry out graft polymerization on the thermoplastic resin micro-porous film system base material, on the epoxy group(ing) of resulting polymkeric substance, introduce anion exchange groups and cation exchange group.In the preferred example of first method, the part of epoxy group(ing) of the graftomer of amine or ammonia and above-mentioned unsaturated glycidyl compound is reacted, make the reaction of vitriol and/or sulphite and unreacted epoxy groups.

The manufacture method of second hydrophilic composite microporous membrane of the present invention is characterized in that, makes the unsaturated monomer that contains anion exchange groups and the unsaturated monomer and the thermoplastic resin micro-porous film system base material that contain cation exchange group carry out graft polymerization.In the preferred example of second method, after making the unsaturated monomer that contains anion exchange groups carry out graft polymerization on the above-mentioned base material, make the unsaturated monomer that contains cation exchange group carry out graft polymerization.

The manufacture method of the 3rd hydrophilic composite microporous membrane of the present invention, it is characterized in that, (i) on thermoplastic resin micro-porous film system base material, make unsaturated glycidyl compound carry out graft polymerization, and on the epoxy group(ing) of resulting polymkeric substance, introduce on the base material that is containing anion exchange groups after the anion exchange groups and make the unsaturated monomer that contains cation exchange group carry out graft polymerization; Or (ii) make unsaturated glycidyl compound and the unsaturated monomer and the thermoplastic resin micro-porous film system base material that contain cation exchange group carry out graft polymerization, and on the epoxy group(ing) of resulting polymkeric substance, introduce anion exchange groups.

The manufacture method of the 4th hydrophilic composite microporous membrane of the present invention, it is characterized in that, (i) make unsaturated glycidyl compound and the unsaturated monomer and the thermoplastic resin micro-porous film system base material that contain anion exchange groups carry out graft polymerization, and on the epoxy group(ing) of resulting polymkeric substance, introduce cation exchange group; Or (ii) on thermoplastic resin micro-porous film system base material, make unsaturated glycidyl compound carry out graft polymerization, on the epoxy group(ing) of resulting polymkeric substance, introduce cation exchange group, make the unsaturated monomer that contains anion exchange groups carry out graft polymerization on the base material of cation exchange group containing afterwards.

The manufacture method of the 5th hydrophilic composite microporous membrane of the present invention, it is characterized in that, on thermoplastic resin micro-porous film system base material, make unsaturated glycidyl compound carry out graft polymerization, and on the epoxy group(ing) of resulting polymkeric substance, introduce anion exchange groups, afterwards base material enforcement plasma gas processing or the Corona discharge Treatment that contains anion exchange groups formed carboxyl.

The manufacture method of one's kin's water-based composite microporous film of the present invention, it is characterized in that, on thermoplastic resin micro-porous film system base material, make the unsaturated monomer that contains anion exchange groups carry out graft polymerization, and resulting base material enforcement plasma gas processing or the Corona discharge Treatment that contains anion exchange groups formed carboxyl.

Hydrophilic composite microporous membrane of the present invention, its water-permeable, physical strength, particulate are removed ability, negatively charged ion removes ability and positively charged ion is removed the ability excellence, are suitable for osmosis filtration film that water treatment uses, ultra-filtration membrane, secondary filter film etc.According to the manufacture method of hydrophilic composite microporous membrane of the present invention, can on the surface of thermoplastic resin micro-porous film system base material and pore internal surface, balancedly introduce anion exchange groups and cation exchange group.

Embodiment

[1] base material

The base material of hydrophilic composite microporous membrane is a thermoplastic resin micro-porous film.

(1) thermoplastic resin

As thermoplastic resin, can list: polyolefin resin, alkene halogenated olefins copolymer resin, fluorine resin, polysulfone resin, polycarbonate resin, vibrin, polyamide resin, polyarylether resin, polyarylene sulfide resin etc.Wherein be preferably polyolefin resin, alkene halogenated olefins copolymer resin and fluorine resin.

As polyolefin resin, can use the homopolymer of ethene, propylene, butylene 1, amylene-1, hexene-1,4-methylpentene-1, octene, vinyl acetate between to for plastic, methyl methacrylate, vinylbenzene etc. and in the multipolymer any.As fluorine resin, can list: poly-inferior ethene, tetrafluoroethylene, tetrafluoroethylene perfluoroalkyl vinyl ether multipolymer, tetrafluoroethylene R 1216 perfluoro propyl vinyl ether copolymers, tetrafluoroethylene hexafluoropropylene copolymer, the ethylene tetrafluoroethylene copolymer etc. fluoridized.

Since the physical strength excellence, therefore, as thermoplastic resin preferred polyolefm resin, the more preferably polythylene resin of the following stated.Polythylene resin is: (a) ultrahigh molecular weight polyethylene(UHMWPE); (b) polyethylene beyond the ultrahigh molecular weight polyethylene(UHMWPE); Or (c) the poly mixture (polyethylene composition) beyond ultrahigh molecular weight polyethylene(UHMWPE) and its.The weight-average molecular weight (Mw) to polythylene resin all has no particular limits under the situation arbitrarily, but is preferably 1 * 10 ⁴～1 * 10 ⁷, more preferably 5 * 10 ⁴～15 * 10 ⁶, be preferably 1 * 10 especially ⁵～5 * 10 ⁶

(a) situation about constituting by ultrahigh molecular weight polyethylene(UHMWPE)

Ultrahigh molecular weight polyethylene(UHMWPE) has 5 * 10 ⁵Above Mw.Ultrahigh molecular weight polyethylene(UHMWPE) is not limited to the homopolymer of ethene, also can be the ethylene that contains other alpha-olefins on a small quantity.Alpha-olefin as beyond the ethene is preferably propylene, butylene-1, amylene-1, hexene-1,4-methylpentene-1, octene-1, vinyl acetate between to for plastic, methyl methacrylate and vinylbenzene.The Mw of ultrahigh molecular weight polyethylene(UHMWPE) is preferably 5 * 10 ⁵～1 * 10 ⁷, more preferably 1 * 10 ⁶～15 * 10 ⁶Scope in, particularly preferably in 1 * 10 ⁶～5 * 10 ⁶Scope in.

(b) situation about constituting by the polyethylene beyond the ultrahigh molecular weight polyethylene(UHMWPE)

Polyethylene beyond the ultrahigh molecular weight polyethylene(UHMWPE) has 1 * 10 ⁴More than～less than 5 * 10 ⁵Mw, be preferably high density polyethylene(HDPE), medium-density polyethylene, chain new LDPE (film grade) and chain new LDPE (film grade), more preferably high density polyethylene(HDPE).Mw is 1 * 10 ⁴More than～less than 5 * 10 ⁵Polyethylene, not only can be the homopolymer of ethene, also can be to contain the multipolymer that a small amount of propylene, butylene-1, hexene-1 wait other alpha-olefins.As this analog copolymer, the preferred multipolymer of making by single site catalysts.

(c) situation about constituting by polyethylene composition

Polyethylene composition is to be 5 * 10 by Mw ⁵Above ultrahigh molecular weight polyethylene(UHMWPE) and the Mw beyond it are 1 * 10 ⁴More than～less than 5 * 10 ⁵The mixture that constitutes of polyethylene (be selected from high density polyethylene(HDPE), medium-density polyethylene, a chain new LDPE (film grade) and the chain new LDPE (film grade) at least a).Ultrahigh molecular weight polyethylene(UHMWPE) and polyethylene in addition thereof can be same as described above.This polyethylene composition can easily be controlled molecular weight distribution [weight-average molecular weight/number-average molecular weight (Mw/Mn)] according to purposes.As polyethylene composition, be preferably the composition of above-mentioned ultrahigh molecular weight polyethylene(UHMWPE) and high density polyethylene(HDPE).The content of ultrahigh molecular weight polyethylene(UHMWPE) when the polyethylene composition total amount is made as 100 quality %, is preferably more than the 1 quality %, more preferably 2～50 quality %.

(d) molecular weight distribution mw/mn

Mw/Mn is the yardstick of molecular weight distribution, and this value is big more, and the amplitude of molecular weight distribution is big more.The Mw/Mn of polythylene resin is unqualified, but under the situation of polythylene resin by any formation in above-mentioned (a)～(c), all is preferably 5～300, and more preferably 10～100.The Mw/Mn of polyethylene (homopolymer or ethylene) can suitably adjust according to multi-stage polymeric.The Mw/Mn of polyethylene composition can suitably adjust according to the molecular weight and the blending ratio of each composition.

(2) rerum natura of the expectation of thermoplastic resin micro-porous film

Pore structure to thermoplastic resin micro-porous film has no particular limits, but excellent particulate is removed characteristic and ion is removed characteristic in order to obtain, and is preferably tridimensional network (the three-dimensional reticulated structure that is formed by connecting brokenly).The average pore aperture is preferably 0.005～0.5 μ m.When average pore aperture during less than 0.005 μ m, the water-permeable after the not only introducing difficulty of ion-exchange group (anion exchange groups, cation exchange group and inner complex form group), and ion-exchange group is introduced is low.On the other hand, when surpassing 0.5 μ m, the particulate composition to remove performance low.At this, the average pore aperture is tried to achieve by the pore pore size distribution curve that obtains by mercury injection apparatus mensuration pore pore size distribution.

Unqualified, but the Gas permeability (JIS P8117) when thickness conversion become 20 μ m is preferably 30～400 seconds/100mL.When being made as this Gas permeability less than 30 seconds/100mL, physical strength reduces, and perhaps the pore aperture increases, therefore, the particulate composition remove degradation.On the other hand, when surpassing 400 seconds/100mL, water-permeable and ventilation property after ion-exchange group is introduced reduce, and have problems in practical application.Unqualified, but void content is preferably 25～80%.When void content was lower than 25%, water-permeable and ventilation property after ion-exchange group is introduced reduced.On the other hand, when surpassing 80%, physical strength reduces.Unqualified, but the intensity that penetrates when thickness conversion become 20 μ m is preferably more than the 1000mN (102gf).

(3) manufacture method of thermoplastic resin micro-porous film

As the method for making above-mentioned such thermoplastic resin micro-porous film, for example can enumerate following method, it comprises: the operation of (a) above-mentioned thermoplastic resin and film forming being carried out melting mixing with solvent; (b) operation that resulting resin solution is extruded from die lip; (c) cooling is resulting is extruded into body and forms the operation of gel sheet material; (d) the gel sheet material is carried out tensile operation (one-off drawing operation); (e) film forming is removed operation with solvent; (f) drying process; (g) dried film is carried out once more tensile operation (secondary stretch operation); And (h) heat treatment step.But be not limited to this method.

(a) melting mixing operation

Melting mixing preferably carries out in forcing machine.As the melting mixing method, for example can utilize the method for record in No. the 3347835th, No. the 2132327th, Japanese Patent or the Japanese Patent.

(b) extrude operation

To extrude from touch tool by forcing machine by the resin solution that melting mixing obtains.As extrusion method, for example can utilize the method for record in No. the 2132327th, the Japanese Patent.

(c) the gel sheet material forms operation

The molding cooling that to extrude from mould forms the gel sheet material.As gel sheet material formation method, for example can utilize the method for record in No. the 2132327th, the Japanese Patent.

(d) one-off drawing operation

The gel sheet material is being stretched on the single shaft direction at least.Cause cracking between thermoplastic resin crystallizing layer lamination by stretching, the miniaturization of thermoplastic resin phase forms a plurality of protofibril.Resulting protofibril forms tridimensional network (three-dimensional is the banded reticulated structure brokenly).As drawing process, for example can utilize the method for record in No. the 2132327th, the Japanese Patent.Therefore omit detailed explanation.

(e) film forming is removed operation with solvent

Use cleaning solvent in film forming in (cleaning) with removing of solvent.As the remove method of the film forming of having used cleaning solvent, for example can utilize the method for record in the Japanese Patent No. 2132327 or TOHKEMY 2002-256099 number with solvent.

(f) drying process of film

Remove the thermoplastic resin micro-porous film that obtains by film forming with solvent, carry out drying by heat drying method, aeration drying etc.

(g) secondary stretch operation

For dried film, preferably stretching on the single shaft direction at least once more.Secondary stretch can be undertaken by tenter machine method etc. in heating film.Secondary stretch can be that uniaxial extension also can be biaxial stretch-formed.Under the biaxial stretch-formed situation, can for simultaneously biaxial stretch-formed or stretch one by one in any, be preferably simultaneously biaxial stretch-formed.

The temperature of secondary stretch, the crystallization dispersion temperature Tcd that is preferably the thermoplastic resin that constitutes base material is above～below the Tcd+40 ℃, more preferably more than Tcd+10 ℃～below the Tcd+40 ℃.When the temperature of this secondary stretch surpassed Tcd+40 ℃, water-permeable and ventilation property reduced, and carried out on horizontal direction (TD direction) perhaps under the tensile situation that the change of rerum natura (particularly Gas permeability) becomes big on the sheet width direction.On the other hand, when the temperature of secondary stretch is lower than Tcd, thermoplastic resin softening insufficient, rupture of membranes easily in stretching can not stretch equably.When thermoplastic resin is made of polythylene resin, make draft temperature usually in 90～140 ℃ scope, preferably in 100～130 ℃ scope.

The multiplying power of secondary stretch on the single shaft direction is preferably 1.1～2.5 times.For example, on length direction (MD direction) or TD direction, it is being 1.1～2.5 times under the situation of uniaxial extension.Under the biaxial stretch-formed situation, be respectively 1.1～2.5 times on MD direction and the TD direction.Under the biaxial stretch-formed situation, as long as each stretching ratio of MD direction and TD direction is 1.1～2.5 times, then mutually can be different on all directions, but preferably identical.This multiplying power is during less than 1.1 times, and water-permeable and ventilation property are insufficient.On the other hand, when this multiplying power surpassed 2.5 times, when the possibility of rupture of membranes improved, heat-resisting shrinkability reduced, and was therefore not preferred.More preferably 1.1～2.0 times of the multiplying powers of secondary stretch.

The speed of secondary stretch is being more than 3%/second on the tensile axis direction preferably.When uniaxial extension, be more than 3%/second on MD direction or the TD direction for example.When biaxial stretch-formed, more than 3%/second on MD direction and the TD direction.Draw speed on the tensile axis direction (%/second) is illustrated in film by in the zone of secondary stretch, the axial length of the stretching before the secondary stretch is made as the ratio of the length that be stretched per 1 second at 100% o'clock.Make this draw speed be lower than 3%/second the time, water-permeable and ventilation property reduce, perhaps the change of rerum natura (particularly Gas permeability) becomes big on the sheet width direction carrying out on the TD direction under the tensile situation.The speed of secondary stretch was preferably more than 5%/second, more than 10%/second more preferably.Under the biaxial stretch-formed situation, if each draw speed of MD direction and TD direction be 3%/second more than, then mutually can be different on MD direction and TD direction, but preferably identical.The upper limit to secondary stretch speed has no particular limits, but considers from the viewpoint that prevents to rupture, and is preferably for 50%/second.

(h) heat treatment step

Preferably the film behind the secondary stretch is heat-treated.As heat treating method, can use heat setting to handle and/or heat mitigation processing.As these methods, for example can utilize the method for record in TOHKEMY 2002-256099 number.

(i) other operations

From the gel sheet material, remove film forming with solvent before, can be provided with that heat setting treatment process, hot-rolling are handled (making the processing of contact hot-rolling at least one face of the gel sheet material after the stretching) operation and hot solvent is handled in (processing that the gel sheet material after the stretching is contacted with hot solvent) operation any.As the heat setting treatment process, can utilize known method as mentioned above.Handle as hot-rolling, for example can utilize the method for record in Japanese Patent Application 2005-271046 number.As the hot solvent treatment process, for example can utilize the method for putting down in writing among the WO2000/20493.

[2] ion-exchange group

Hydrophilic composite microporous membrane has anion exchange groups and cation exchange group on any of the surface of above-mentioned thermoplastic resin micro-porous film system base material and pore internal surface.Hydrophilic composite microporous membrane preferably all has two kinds of ion-exchange groups at the surface of base material and pore internal surface on the two.

(1) anion exchange groups

As anion exchange groups, be preferably by formula (1):

-NH ₂ …(1)

The primary amino of expression, by formula (2):

(R wherein ¹The expression alkyl) secondary amino group of expression is by formula (3):

(R wherein ²And R ³The expression alkyl) uncle's amino of expression, by formula (4):

(R wherein ⁴～R ⁶The expression alkyl) quaternary ammonium group and the assorted cyclic amine residue (pyridines, imidazoles etc. have the residue of the amine of heterocycle structure) of expression are more preferably as alkaline quaternary ammonium group.Alkyl (the R that has as the amino in the second month in a season～season ¹～R ⁶), can in alkyl, aryl and the aralkyl any.

The amount of anion exchange groups, the every 1g of preferred hydrophilic composite microporous film is more than 0.1 milliequivalent, more preferably more than 0.2 milliequivalent.When this amount was lower than 0.1 milliequivalent/g, it is insufficient that negatively charged ion is removed ability.

(2) cation exchange group

As cation exchange group, can list: sulfonic group, carboxyl, Phosphorus sour residue (for example, phosphate, phosphonate group etc.) etc. are preferably sulfonic group and carboxyl.The amount of cation exchange group, the every 1g of preferred hydrophilic composite microporous film is more than 0.1 milliequivalent, more preferably more than 0.2 milliequivalent.When this amount was lower than 0.1 milliequivalent/g, it is insufficient that positively charged ion is removed ability.

(3) ratio of anion exchange groups and cation exchange group

The ratio of anion exchange groups and cation exchange group can be according to suitable setting that become to assign to of removing, but is preferably 10/90～90/10 with molar ratio computing anion exchange groups/cation exchange group, and more preferably 20/80～80/20.

(4) inner complex forms group

Hydrophilic composite microporous membrane as required, can have inner complex and form group as the ion-exchange group beyond anion exchange groups and the cation exchange group.It is the functional group with the function that forms metal ion and inner complex that inner complex forms group.Form group as inner complex, can list: imino-diacetic acetoxy group, sulfydryl, quadrol residue etc.Inner complex forms the ratio of group, when ion-exchange group integral body is made as 100 moles of %, is preferably 20 moles below the %.

(5) total amount of ion-exchange group

The total amount of ion-exchange group (anion exchange groups, cation exchange group and inner complex form the total amount of group), the every 1g of preferred hydrophilic composite microporous film is below 10 milliequivalents, more preferably below 5 milliequivalents.When this amount surpasses 10 milliequivalents/g, might cause the pore obturation.

[3] manufacture method of hydrophilic composite microporous membrane

The method of making hydrophilic composite microporous membrane has: (1) introduces operation, (2) matting and (3) drying process of anion exchange groups and cation exchange group on above-mentioned thermoplastic resin micro-porous film system base material.In operation (1), introduce under the situation of uncle's amino, preferably carry out (4) quaternised operation afterwards in operation (1).As required, operation (1) afterwards (when carrying out operation (4), before) in operation (4) can carry out (5) inner complex and form group and introduce operation.

(1) the introducing operation of anion exchange groups and cation exchange group

(1)-1 anion exchange groups introducing method

Method as introduce anion exchange groups on base material has: (a) make the unsaturated monomer that contains anion exchange groups carry out the method (second anion exchange groups is introduced method) of graft polymerization on base material in the method (first anion exchange groups is introduced method) that unsaturated glycidyl compound is carried out amine or ammonia are reacted and (b).

(a) first anion exchange groups is introduced method

(i) make unsaturated glycidyl compound carry out the operation of graft polymerization

As on base material, making unsaturated glycidyl compound carry out the method for graft polymerization, have: make method (front irradiation method) that unsaturated glycidyl compound reacts and the method (irradiation simultaneously) that makes irradiation ionizing radiation under the unsaturated glycidyl compound state of contact on the base material behind the ionizing radiation in irradiation on the base material.Because ionizing radiation is transmitted to the inside of base material, therefore on the main chain of the thermoplastic resin of the surface of base material and pore internal surface, form the side chain that the polymkeric substance by unsaturated glycidyl compound constitutes almost evenly.As ionizing radiation, can list: alpha-ray, β ray (electron rays), gamma-rays and X ray, but on operability preferred electron ray or gamma-rays.Use under the situation of electron rays,, preferably use the front irradiation method in order to suppress the homopolymerization of unsaturated glycidyl compound.

When carrying out the electron rays processing in the front irradiation method, preferably the acceleration voltage with electron rays is made as 100～5000keV, more preferably is made as 1000～4000keV.The electron rays irradiation can be carried out under air atmosphere, but preferably carries out under atmosphere of inert gases.As the useful to irradiation of rays amount, be suitably 10～500kGy, be preferably 50～200kGy.During useful to irradiation of rays quantity not sufficient 10kGy, the grafting of unsaturated glycidyl compound is not carried out fully, when surpassing 500kGy, and base material variation sometimes.

The unsaturated glycidyl compound that makes gas or liquid produces free radical with the irradiation electron rays base material contacts.As unsaturated glycidyl compound, so long as have the compound of glycidyl and unsaturated group, then have no particular limits, but be preferably glycidyl (methyl) vinylformic acid.Method (gas method) as the unsaturated glycidyl compound that makes gas contacts with base material can list: postradiation base material be impregnated in the solvent, makes the unsaturated glycidyl compound that forms of gasifying carry out the method for bubbling in solvent.Method (liquid method) as the unsaturated glycidyl compound that makes liquid contacts with base material can list: postradiation base material be impregnated in the solution of unsaturated glycidyl compound or the method in the dispersion liquid.In any means, all can make water and organic solvent as solvent, but be preferably organic solvent.Preferred lower alcohol is as organic solvent.As lower alcohol, can list: methyl alcohol, ethanol, Virahol (IPA), butanols etc.As required, can in the solution of unsaturated glycidyl compound or dispersion liquid, add tensio-active agent.

The solution of unsaturated glycidyl compound or the concentration in the dispersion liquid are preferably 0.1～20 quality %, more preferably 0.5～10 quality %.When this concentration is lower than 0.1 quality %, can not make the unsaturated glycidyl compound of abundant amount and base material carry out graft polymerization.On the other hand, when surpassing 20 quality %, the control difficulty of polymerization amount.The solution of unsaturated glycidyl compound or dispersion liquid preferably carried out deoxidation before the dipping base material.As method of deoxidation, can list the method for rare gas element being carried out bubbling.As required, can in the dipping of base material, carry out bubbling to rare gas element.Dipping temperature is preferably 0～90 ℃, more preferably 20～70 ℃.Treatment time is according to dipping temperature and difference, for example 50 ℃ about 10～60 minutes down.

As required, under the linking agent coexistence, can carry out graft polymerization.As linking agent, for example can list Vinylstyrene etc.In addition, in order to prevent the homopolymerization of unsaturated glycidyl compound, polymerizations such as Mo Er salt (ferrous sulfate (II) ammonium hexahydrate), hydroquinone monomethyl ether can be forbidden agent and IPA, ethylene dichloride etc.

The percentage of grafting of unsaturated glycidyl compound when the base material before the grafting is made as 100 quality %, is preferably 5～100 quality %, more preferably 10～50 quality %.

(ii) anion exchange groups is introduced operation

On the epoxy group(ing) of the polymkeric substance (side chain) of unsaturated glycidyl compound, introduce anion exchange groups.Particularly, on epoxide group, make amine or ammonia react, form in primary～uncle amino any.The preferred amine that uses forms the second month in a season or uncle's amino.When forming quaternary ammonium group, after forming uncle's amino, carry out quaternized.Wherein, quaternized processing is preferably carried out after cation exchange group is also introduced.

As amine, can list: fatty amine, aromatic amine, ester ring type amine, aliphatic hydroxyl amine, aliphatie diamine, aromatic diamine, assorted cyclic amine etc., but consider from the viewpoint of alkaline intensity, be preferably fatty amine and assorted cyclic amine.As fatty amine, for example can list: methylamine, dimethylamine, ethamine, diethylamine, Tri N-Propyl Amine, di-n-propylamine, n-Butyl Amine 99, Di-n-Butyl Amine, n-amylamine, normal hexyl Amine, lauryl amine etc.As assorted cyclic amine, for example can list: pyridine, imidazoles etc.They can use separately, also can and have more than 2 kinds.

In order to make amine and epoxy reaction, the base material that preferably will be formed with side chain impregnated in the solution or dispersion liquid of amine.As solvent, can be in water, organic solvent and their mixed solvent any.Wherein, be preferably water lower alcohol mixed solvent.By amine concentration, dipping temperature and the treatment time in suitable regulator solution or the dispersion liquid, the introducing amount of amine is regulated.Unqualified, but preferred amines concentration is 0.5～15 quality %.Dipping temperature is preferably 0～90 ℃, more preferably 20～70 ℃.Treatment time is according to dipping temperature and difference, for example 50 ℃ about 30 minutes～2 hours down.

(b) second anion exchange groups is introduced method

In second method, on base material with above-mentioned same irradiation ionizing radiation after, make the unsaturated monomer contact that contains anion exchange groups, carry out graft polymerization.As the unsaturated monomer that contains anion exchange groups, can list: vinyl pyridine, vinyl imidazole, diallyl methylamine, allylamine, N, N-dimethyl p-aminophenyl ethene, N, N-diethyl p-aminophenyl ethene, vinyl amine, N, N-dimethylaminomethyl (methyl) acrylate, N, N-diethylamino methyl (methyl) acrylate, N, N-dimethyl aminoethyl (methyl) acrylate, N, N-diethylamino ethyl (methyl) acrylate etc.

The method that the unsaturated monomer that contains anion exchange groups is contacted with base material can be in gas method or the liquid method any.Using under the situation of liquid method, solvent, monomer concentration, dipping temperature and treatment time, can be with to make unsaturated glycidyl compound carry out the situation of graft polymerization identical.

(1)-2 cation exchange group introducing method

(a) sulfonic group introducing method

As on base material, introducing sulfonic method, have: (i) on base material, make unsaturated glycidyl compound carry out graft polymerization, make any method (first sulfonic group introducing method) of reacting with the epoxy group(ing) of resulting polymkeric substance in vitriol and the sulphite; And (ii) on base material, make the method that contains sulfonic unsaturated monomer and carry out graft polymerization (second sulfonic group is introduced method).

(i) first sulfonic group is introduced method

In first method,, after making unsaturated glycidyl compound carry out graft polymerization on the base material, any [(Asia) vitriol] in vitriol and the sulphite is reacted with the epoxy group(ing) of resulting polymkeric substance (side chain) with above-mentioned same.As vitriol, can list: sulfuric acid an alkali metal salts such as sodium sulfate, vitriolate of tartar.As sulphite, can list: alkali sulfite metal-salt (for example S-WAT, potassium sulfite etc.), magnesium sulfite, sodium bisulfite, Potassium hydrogen sulfite, ammonium sulphite etc.They can use separately, also can and have more than 2 kinds.

In order to make (Asia) vitriol and epoxy reaction, the base material that preferably will be formed with side chain impregnated in the solution or dispersion liquid of (Asia) vitriol.Solvent is identical with the situation that makes the amine reaction.(Asia) sulfate concentration in solution or the dispersion liquid is preferably 0.5～10 quality %.Dipping temperature is preferably 0～100 ℃, more preferably 20～90 ℃.Treatment time is according to dipping temperature and difference, for example 80 ℃ about 10～20 hours down.After making (Asia) vitriol and epoxy reaction, handle with hydrochloric acid etc., the exchange of basic metal plasma is become proton, thus, can obtain sulfonic group.

(ii) second sulfonic group is introduced method

In second method, with above-mentioned same, on base material, after the irradiation ionizing radiation, make and contain sulfonic unsaturated monomer contact, carry out graft polymerization.As containing sulfonic unsaturated monomer, can list: vinyl sulfonic acid, p styrene sulfonic acid, allyl sulphonic acid, methallylsulfonic acid, (methyl) vinylformic acid butyl-4-sulfonic acid, (methyl) acryloxy Phenylsulfonic acid, tertiary butyl acrylamide sulfonic acid etc.They can use separately, also can and have more than 2 kinds.

Make and contain the method that sulfonic unsaturated monomer contacts with base material, can be in gas method or the liquid method any.Using under the situation of liquid method, solvent, monomer concentration, dipping temperature and treatment time, can be with to make unsaturated glycidyl compound carry out the situation of graft polymerization identical.

(b) carboxyl introducing method

Method as introduce carboxyl on base material has: (i) on base material, make unsaturated glycidyl compound carry out graft polymerization and make fatty acid alkali metal salt and the hydroxycarboxylic acid an alkali metal salt in any method (first carboxyl introducing method) of reacting with the epoxy group(ing) of resulting polymkeric substance; And (ii) on base material, make the unsaturated monomer that contains carboxyl carry out the method (second carboxyl is introduced method) of graft polymerization; And the method (the 3rd carboxyl is introduced method) of (iii) base material being carried out plasma gas processing or Corona discharge Treatment.

(i) first carboxyl is introduced method

In first method,, after making unsaturated glycidyl compound carry out graft polymerization on the base material, the epoxy group(ing) of any and resulting polymkeric substance (side chain) in fatty acid alkali metal salt and the hydroxycarboxylic acid an alkali metal salt is reacted with above-mentioned same.As fatty acid alkali metal salt, can list: sodium-acetate, Sodium Propionate, Sodium propanecarboxylate, Sodium n-caproate, Sodium octoate, Sodium decanoic acid, sodium laurate, Sodium tetradecanoate, Sodium pentadecanecarboxylate, sodium stearate etc.As the hydroxycarboxylic acid an alkali metal salt, can list: sodium glycolate, Sodium.alpha.-hydroxypropionate, sodium malate, sodium tartrate, Trisodium Citrate, Sunmorl N 60S etc.They can use separately, also can and have more than 2 kinds.

For any and epoxy group(ing) in fatty acid alkali metal salt and the hydroxycarboxylic acid an alkali metal salt are reacted, preferably will make unsaturated glycidyl compound carry out base material that graft polymerization forms and impregnated in any solution or dispersion liquid in fatty acid alkali metal salt and the hydroxycarboxylic acid an alkali metal salt.Solvent is identical with the situation that makes the amine reaction.Salt concn in solution or the dispersion liquid is preferably 0.5～10 quality %.Dipping temperature is preferably 0～100 ℃, more preferably 20～90 ℃.Treatment time is according to dipping temperature and difference, for example 80 ℃ about 10～20 hours down.After fatty acid alkali metal salt and/or hydroxycarboxylic acid an alkali metal salt and epoxy group(ing) are reacted, handle with hydrochloric acid etc., the alkalimetal ion exchange is become proton, thus, can obtain carboxyl.

(ii) second carboxyl is introduced method

In second method, with above-mentioned same, on base material, after the irradiation ionizing radiation, make the unsaturated monomer contact that contains carboxyl, carry out graft polymerization.As the unsaturated monomer that contains carboxyl, can list: (methyl) vinylformic acid, toxilic acid, fumaric acid, bridge dicyclo [2.2.1]-5-heptene-2, undersaturated list or dicarboxylic acid or their derivatives etc. such as 3-dicarboxylic acid (nadic acid), tetrahydrophthalic acid, methylene-succinic acid, citraconic acid, Ba Dousuan, iso-crotonic acid.As such derivative, for example can list: acid anhydride, acyl chlorides, acid amides, inferior acid amides, ester etc.As the object lesson of derivative, can list: maleic anhydride, chlorination toxilic acid, maleinamide, norbornene dicarboxylic anhydride, methyl acrylate, methyl methacrylate, citraconic anhydride, monomethyl maleate, dimethyl maleate etc.They can use separately, also can and have more than 2 kinds.Wherein be preferably (methyl) vinylformic acid.

The method that the unsaturated monomer that contains carboxyl is contacted with base material can be in gas method or the liquid method any.Using under the situation of liquid method, solvent, monomer concentration, dipping temperature and treatment time, can be with to make unsaturated glycidyl compound carry out the situation of graft polymerization identical.

(iii) the 3rd carboxyl is introduced method

In third party's method, handle or Corona discharge Treatment by base material being carried out plasma gas, form carboxyl.Plasma gas is handled can use known plasma gas generation device, by carrying out in the plasma gas that base material is exposed to generation.As plasma generation gas, use argon gas, helium, nitrogen, air etc.The high frequency electric power optimized frequency that plasma gas is produced is 1～30MHz, and power is preferably 1～5000W, more preferably 100～3000W.Preferably plasma gas is paid in spray on base material, and its flow is preferably 0.002～2L/min/cm ², 0.02～1.2L/min/cm more preferably ²

Corona discharge Treatment is used known Corona discharge Treatment device, by carrying out in the corona atmosphere that base material is exposed to generation.Corona discharge Treatment is preferably carried out under air atmosphere.Total discharge capacity in Corona discharge Treatment is preferably 1～5000W/m ²/ min, more preferably 100～3000W/m ²/ min.Plasma gas is handled and the pressure of Corona discharge Treatment is that normal atmosphere gets final product, and the time is preferably 1～1000 second.

(1)-3 the combination of each method

By above-mentioned anion exchange groups is introduced method, sulfonic group introduces method and carboxyl introducing method suit to make up, and can introduce in anion exchange groups, sulfonic group and the carboxyl any on base material.

(a) introduce anion exchange groups and sulfonic situation

Combination as introduce anion exchange groups and sulfonic situation on base material can list: first anion exchange groups introducing method and first sulfonic group are introduced combination B, first anion exchange groups of combination A, second anion exchange groups introducing method and second sulfonic group introducing method of method and are introduced the combination C of method and second sulfonic group introducing method and the combination D that second anion exchange groups is introduced method and first sulfonic group introducing method.Wherein be preferably combination A.

(i) combination A

Combination A has: make unsaturated glycidyl compound carry out introducing on the operation of graft polymerization and the epoxy group(ing) at resulting polymkeric substance anion exchange groups and sulfonic operation on the base material.Unqualified, but preferably introduce with anion exchange groups, sulfonic order.That is, preferably make the part reaction of epoxy group(ing) of the polymkeric substance of amine or ammonia and unsaturated glycidyl compound, (Asia) vitriol and unreacted epoxy groups are reacted, afterwards, carry out ion-exchange.Introduce sulfonic group earlier, when perhaps amine or ammonia and (Asia) vitriol are simultaneously with epoxy reaction, hinder the addition reaction of amine or ammonia, the introducing of anion exchange groups becomes difficulty.

(ii) make up B

In combination B, on base material, make the unsaturated monomer that contains anion exchange groups and contain sulfonic unsaturated monomer and carry out graft polymerization.Unqualified, but, preferably carry out graft polymerization with the unsaturated monomer that contains anion exchange groups, the order that contains sulfonic unsaturated monomer in order to make two monomers balancedly carry out graft polymerization.But, as required, can carry out graft polymerization with opposite order, also can make two monomers carry out graft polymerization.

In other operation, contain anion exchange groups unsaturated monomer graft polymerization and contain under the situation of graft polymerization of sulfonic unsaturated monomer, preferably before each graft polymerization, carry out radiation exposure.Therefore, for deterioration that suppresses base material or the decomposition that suppresses the ion-exchange group of elder generation's introducing, the irradiation quantity of X-rays X is suited to control.Particularly, preferably the useful to irradiation of rays amount is made as 50～200kGy.The acceleration voltage of electron rays can be same as described above.Below repeatedly carrying out in the combination of radiation exposure preferred setting illuminated line amount same as described above.

(iii) make up C

In combination C, on base material, make unsaturated glycidyl compound carry out graft polymerization, on the epoxy group(ing) of resulting polymkeric substance, introduce anion exchange groups, contain sulfonic unsaturated monomer and carry out graft polymerization (combination C-1) containing to make on the base material of anion exchange groups afterwards; Perhaps on base material, make unsaturated glycidyl compound and contain sulfonic unsaturated monomer and carry out graft polymerization, on the epoxy group(ing) of resulting polymkeric substance, introduce anion exchange groups (combination C-2).

In combination C-1, preferably before each graft polymerization, carry out radiation exposure.In combination C-2, can on the base material after the radiation treatment, make unsaturated glycidyl compound and contain sulfonic unsaturated monomer and carry out graft copolymerization, also can carry out graft polymerization with unsaturated glycidyl compound, the order that contains sulfonic unsaturated monomer.The former carries out the method for graft copolymerization, with only make unsaturated glycidyl compound carry out the method for graft polymerization in itself can be identical.The latter carries out under the situation of graft polymerization in turn, preferably carries out radiation exposure before the graft polymerization that contains sulfonic unsaturated monomer once more.

(iv) make up D

In combination D, on base material, make unsaturated glycidyl compound and the unsaturated monomer that contains anion exchange groups carry out graft polymerization, on the epoxy group(ing) of resulting polymkeric substance, introduce sulfonic group (combination D-1); Perhaps on base material, make unsaturated glycidyl compound carry out graft polymerization, on the epoxy group(ing) of resulting polymkeric substance, introduce sulfonic group, make the unsaturated monomer that contains anion exchange groups carry out graft polymerization (combination D-2) on the sulfonic base material containing afterwards.，

In combination D-1, the unsaturated monomer and the base material after the radiation treatment that can make unsaturated glycidyl compound and contain anion exchange groups carry out graft copolymerization, also can carry out graft polymerization with unsaturated glycidyl compound, the order that contains the unsaturated monomer of anion exchange groups.The former carries out the method for graft copolymerization, with only make unsaturated glycidyl compound carry out the method for graft polymerization in itself can be identical.The latter carries out under the situation of graft polymerization in turn, preferably carries out radiation exposure before the graft polymerization of the unsaturated monomer that contains anion exchange groups once more.In combination D-2, preferably before each graft polymerization, carry out radiation exposure.

(b) situation of introducing anion exchange groups and carboxyl

Combination as introduce the situation of anion exchange groups and carboxyl on base material can list: first anion exchange groups is introduced the combination E of method and first carboxyl introducing method, second anion exchange groups is introduced the combination F of method and second carboxyl introducing method, first anion exchange groups is introduced the combination G of method and second carboxyl introducing method, second anion exchange groups is introduced the combination H of method and first carboxyl introducing method, first anion exchange groups is introduced the combination I of method and the 3rd carboxyl introducing method, and second anion exchange groups introduce the combination J that method and the 3rd carboxyl are introduced method.Wherein be preferably combination G, I or J.

Combination E and H, except introducing carboxyl replacement sulfonic group [any replacement (Asia) vitriol and epoxy group(ing) in fatty acid alkali metal salt and the hydroxycarboxylic acid an alkali metal salt are reacted], can be identical respectively with combination A and D.

Combination F and G, except introducing carboxyl replacement sulfonic group (make the unsaturated monomer that contains carboxyl replace containing sulfonic unsaturated monomer and carry out graft polymerization), can be identical respectively with combination B and C.

Combination I has: make on the base material unsaturated glycidyl compound carry out introducing on the operation of graft polymerization, the epoxy group(ing) at resulting polymkeric substance anion exchange groups operation, containing and implementing on the base material of anion exchange groups that plasma gas is handled or Corona discharge Treatment forms the operation of carboxyl.These each operations can be as above-mentioned.

Combination J has: make the unsaturated monomer that contains anion exchange groups carry out the operation of graft polymerization on the base material and implementing on the resulting base material that contains anion exchange groups that plasma gas is handled or Corona discharge Treatment forms the operation of carboxyl.These each operations can be as above-mentioned.(c) situation of introducing anion exchange groups, sulfonic group and carboxyl

As the situation of in base material, introducing anion exchange groups, sulfonic group and carboxyl, unqualified, introduce the combination that method, first sulfonic group base introducing method and the 3rd carboxyl are introduced method but be preferably first anion exchange groups.Particularly, preferably carry out successively make unsaturated glycidyl compound carry out introducing anion exchange groups and sulfonic operation on the operation of graft polymerization, the epoxy group(ing) on the base material at resulting polymkeric substance and containing anion exchange groups and sulfonic base material on implement that plasma gas is handled or Corona discharge Treatment forms the operation of carboxyl.These each operations can be as above-mentioned.

(2) matting

Introducing there is the base material of anion exchange groups and cation exchange group in water, toluene, dimethylbenzene equal solvent, clean one day one night.

(3) drying process

Film after cleaning is carried out drying by heat drying method, aeration drying etc., obtain hydrophilic composite microporous film thus.

(4) quaternized operation

When introducing uncle's amino, before cleaning-drying, preferably be used for the quaternized of highly basicization by above-mentioned anion exchange groups introducing method.For quaternized, make the amino reaction of halogenated aryl, chloropharin, halogenated alkyl etc. and uncle.As halogenated aryl, be preferably benzyl halides such as Benzyl Chloride.As chloropharin, can list: chloroethanol, pure propyl alcohol etc.These halogen compounds can be used separately, also can and have more than 2 kinds.As quaternised method, be preferably the method that in the solution of above-mentioned halogen compounds or dispersion liquid dipping is introduced the base material that the amino and cation exchange group of uncle is arranged.Solvent is identical with the situation of the solution of preparation amine.The concentration of the halogen compounds in solution or the dispersion liquid is preferably 0.5～20 quality %.Dipping temperature is preferably 0～100 ℃, more preferably 20～90 ℃.Treatment time is according to dipping temperature and difference, for example 80 ℃ about 10～50 hours down.Be formed with the film of quaternary ammonium group and above-mentionedly clean drying equally.

(5) inner complex forms group and introduces operation

Can introduce inner complex as required and form group.On base material, introduce after anion exchange groups and the cation exchange group and form group uncle's amino being carried out introduce inner complex before quaternized.Form group in order to introduce inner complex, can prepare the solution or the dispersion liquid of imino-diacetic sodium-acetate etc., film immersion in wherein, is made the unreacted epoxy reaction of the polymkeric substance of itself and unsaturated glycidyl compound.

[4] rerum natura of hydrophilic composite microporous membrane

According to above-mentioned manufacture method, obtain a kind of hydrophilic composite microporous membrane, it balancedly all has anion exchange groups and cation exchange group on the surface of thermoplastic resin micro-porous film system base material and pore internal surface, and has tridimensional network.Hydrophilic composite microporous membrane according to preferred implementation of the present invention has following rerum natura.

The average pore aperture of (1) 0.005～0.5 μ m

When the average pore aperture was lower than 0.005 μ m, water-permeable was low.When the average pore aperture surpasses 0.5 μ m, the particulate composition to remove performance low.

(2) 30～400 seconds/100cm ³Gas permeability (being scaled thickness 20 μ m)

If thickness being converted into the Gas permeability (JIS P8117) of 20 μ m is 30～400 seconds/100cm ³, then the water-permeable during as membrane for water treatment (the osmosis filtration film used of water treatment, ultra-filtration membrane, secondary filter film etc.) is good with hydrophilic composite microporous membrane.

(3) 25～80% void content

If void content is lower than 25%, then can not obtain good water-permeable and ventilation property.On the other hand, if surpass 80%, then physical strength is low.

(4) 1000mN/20 μ m is above penetrates intensity

Be lower than 1000mN/20 μ m if penetrate intensity, the weather resistance when then hydrophilic composite microporous membrane being used as membrane for water treatment is low.

As mentioned above, the physical strength of hydrophilic composite microporous membrane and water-permeable excellence.In addition, hydrophilic composite microporous membrane is for the ability of removing of particulate (for example metal oxide microparticle etc.), for the ability of removing of negatively charged ion (for example inorganic acid ion etc.) and for the ability of the removing excellence of positively charged ion (for example metal ion etc.).Hydrophilic composite microporous membrane with such characteristic is suitable for membrane for water treatment.

If with hydrophilic composite microporous membrane be arranged on for example carry out that semi-conductor etc. cleans with before the water spot, then, therefore, can improve the yield rate in the semi-conductor manufacturing process owing to can remove the impurity of denier in the ultrapure water.In addition, even hydrophilic composite microporous membrane is arranged on before the water spot, owing to do not need boosting pump again, therefore, also do not need to change the withstand voltage mode of pipe arrangement etc., the cost of device cost is low.In the time of before being arranged on hydrophilic composite microporous membrane with water spot, the preferred flat sheet membrane that is filled with hydrophilic composite microporous membrane of using in the chassis.

Because hydrophilic composite microporous membrane also has affinity to negatively charged ion and positively charged ion, therefore, the possibility height of the characteristic of also performance excellence in purposes such as the solid polyelectrolyte membrane that fuel cell is used and the dividing plate that uses for nickel-hydrogen battery.The thickness of hydrophilic composite microporous membrane can suit to select according to purposes, but is generally 5～200 μ m, is preferably 5～100 μ m during as membrane for water treatment.

Embodiment

By following embodiment the present invention is described in more detail, but the present invention is not limited to these examples.

Embodiment 1

(1) manufacturing of microporous polyethylene film

Be 2.0 * 10 by weight-average molecular weight (Mw) ⁶And molecular weight distribution (Mw/Mn) is that 8 ultrahigh molecular weight polyethylene(UHMWPE) (UHMWPE) 20 quality % and Mw are 3.5 * 10 ⁵And Mw/Mn is that dry type is mixed four [methylene radical-3-(3,5-di-t-butyl-4-hydroxyphenyl)-propionic ester] methane 0.375 mass parts in polyethylene (PE) composition 100 mass parts that constitute of 13.5 high density polyethylene(HDPE) (HDPE) 80 quality %.The PE composition that is made of UHMWPE and HDPE is measured and the Mw/Mn that obtains is 16, and fusing point is 135 ℃, and the crystallization dispersion temperature is 100 ℃.

Under following condition, try to achieve the Mw and Mw/Mn (following identical) of UHMWPE and HDPE by gel permeation chromatography (GPC) method.

Determinator: GPC-150C that Waters Corporation makes

Chromatographic column: the Shodex UT806M that Showa Denko K. K makes

Column temperature: 135 ℃

Solvent (moving phase): orthodichlorobenzene

Solvent flow rate: 1.0ml/ branch

Sample concentration: 0.1 quality % (dissolution conditions: 135 ℃/1h)

Sample size: 500 μ l

Detector: the differential refractometer (DifferentialRefractometer) that Waters Corporation makes

Typical curve:, use the conversion constant of regulation to make by the typical curve that uses the monodisperse polystyrene standard model to obtain.

To strong mixed milling type twin screw extruder (internal diameter 58mm, L/D=42) drop into resulting PE composition 25 mass parts in, supply with the whiteruss of 75 mass parts from the side feed opening (side feeder) of twin screw extruder, under the condition of 210 ℃ and 200rpm, carry out melting mixing, in forcing machine, prepare polyethylene solution.This polyethylene solution being supplied to the T mould from twin screw extruder, make it be extruded as the sheet material that thickness is 2.0mm, is 40 ℃ cooling roller when drawing with temperature regulation, forms the gel sheet material.

To resulting gel sheet material, use the continous way drawing machine, it is biaxial stretch-formed to carry out the while under 119.5 ℃, makes it all reach 5 times in MD direction and TD direction.It is in 25 ℃ the rinse bath of methylene dichloride that stretching gel sheet material be impregnated in temperature regulation, cleans continuously.Film after cleaning is at room temperature air-dry, be wound into reel.Resulting film once more by the continous way drawing machine, to stretch for 15%/second, is made in the TD direction to reach 1.4 times under 110 ℃ temperature.Will be again stretched film be fixed on the tenter machine, handle and make microporous polyethylene film 30 seconds by under 110 ℃, carrying out heat setting.The rerum natura of resulting microporous polyethylene film is: average film thickness is 31.0 μ m, and Gas permeability is 85 seconds/100mL/20 μ m, and void content is 63.5%, and the average pore aperture is 0.085 μ m, and penetrating intensity is 240gf/20 μ m.The assay method of each rerum natura following (following identical).

(a) average film thickness (μ m)

In the width range of the 30cm of micro-porous film, with the length direction of 5mm at interval, measure thickness by the contact thickness gauge, the measured value of thickness is averaged.

(b) Gas permeability (sec/100cm ³/ 20 μ m)

Will be to thickness T ₁Micro-porous film measure the Gas permeability P that obtains according to JIS P8117 ₁, according to formula: P ₂=(P ₁* 20)/T ₁, the Gas permeability P when being converted into thickness and being 20 μ m ₂

(c) void content (%)

Measure by mass method.

(d) penetrate intensity (mN/20 μ m)

To with front end being sphere (radius of curvature R: the pin of diameter 1mm 0.5mm), penetrate thickness T with the speed of 2mm/ second ₁Micro-porous film the time maximum load measure.According to formula: L _b=(L _a* 20)/T ₁, with the measured value L of maximum load _aMaximum load L when being converted into thickness and being 20 μ m _b, obtain penetrating intensity.

(2) graft polymerization of glycidyl methacrylic acid

Resulting microporous polyethylene film is fixed on the deckle board (size: 30cm * 30cm, aluminum), cleans drying by impregnated in the hexane.The use rumbatron (acceleration voltage: 3.0MeV, electron rays electric current: 5mA), at the electron rays that under nitrogen atmosphere, shines 80kGy on the exsiccant film.Film directly is fixed on the deckle board, impregnated in the 1 quality % methanol solution of the glycidyl methacrylic acid that has carried out deoxidation in advance, carried out graft polymerization 30 minutes under 50 ℃, use washed with methanol, drying.By the percentage of grafting that the quality change of the film per unit area before and after the graft polymerization calculates, when the microporous polyethylene film before the grafting is made as 100 quality %, be 20 quality %.This amount is scaled 1.4 milliequivalents/g with glycidyl.

(3) the introducing operation of uncle's amino

Directly be fixed on the film that makes the glycidyl methacrylic acid carry out graft polymerization and obtain on the frame, under 50 ℃ temperature, impregnated in the IPA/ water mixed solvent (mass ratio: in the solution (concentration 10 quality %) of IPA/ water=11.1/88.9) 1 hour of dimethylamine, after the amine addition reaction on carrying out epoxy group(ing), clean with pure water.The part of this film be impregnated in the sodium hydroxide of 1N, dimethylamino is made the OH type, clean with pure water, after the drying, make the hydrochloric acid reaction of 1N, the HCl amount that consumes is carried out neutralization titration with alkali, thus, try to achieve the amine amount of introducing, the result is scaled 0.5 milliequivalent/g with glycidyl.

(4) sulfonic introducing operation

Introducing there is the film of dimethylamino under 80 ℃ temperature, impregnated in the IPA/ water mixed solvent solution of S-WAT 15 minutes, S-WAT and unreacted epoxy groups are reacted.Resulting film is cleaned with pure water, impregnated in the hydrochloric acid of 1N sodium is carried out ion-exchange, thus, form the sulfonic group of H type, clean drying with pure water.By measuring the infrared spectra of resulting film, confirm to have introduced sulfonic group.If introduce sulfonic group fully on the unreacted epoxy group(ing), then sulfonic introducing amount is scaled 0.9 milliequivalent/g with glycidyl.

(5) to the conversion reaction operation of quaternary ammonium group

There are dimethylamino and sulfonic microporous polyethylene film under 80 ℃ temperature, to impregnated in the IPA solution (concentration 10 quality %) of Benzyl Chloride 15 minutes introducing, carry out dimethylamino quaternized.Resulting film is fully cleaned in pure water, and drying obtains having quaternary ammonium group and sulfonic hydrophilic composite microporous membrane.

(6) rerum natura

The average film thickness of resulting hydrophilic composite microporous membrane is 32.3 μ m, and Gas permeability is 110 seconds/100mL/20 μ m, and void content is 59.5%, and penetrating intensity is 220gf/20 μ m.

Comparative example 1

Except only introducing on the microporous polyethylene film the sulfonic group, hydrophilic composite microporous membrane is made in operation similarly to Example 1.

Comparative example 2

Except only introducing on the microporous polyethylene film the quaternary ammonium group, hydrophilic composite microporous membrane is made in operation similarly to Example 1.

Comparative example 3

Making is laminated with the hydrophilic composite microporous membrane of the film of comparative example 1 and 2.

Be produced on and be filled with the hydrophilic composite microporous membrane that obtains by embodiment 1 and comparative example 1～3 (flat sheet membrane of 5cm * 5cm) in the chassis respectively, use has the water of the composition shown in the table 1, according to following method water-permeable and filtering feature (for the characteristic of removing of silicon dioxide microparticle, negatively charged ion and metal ion) is measured.Show the result in table 2.

(a) permeable speed is (L/ hour/m ²/ atm)

Under the pressure condition of room temperature and 50.54kPa (380mmHg), make the water of 1L see through flat sheet membrane, measure the time that needs that sees through, according to formula: permeable speed (L/ hour/m ²/ atm)=permeable amount (L)/time (hour)/film size (m ²)/pressure (atm) is tried to achieve.

(b) mensuration of silicon dioxide microparticle concentration

Make water see through flat sheet membrane under these conditions, the silicon dioxide microparticle concentration of the water before and after filtering by particle collector mensuration (individual/mL).

(c) mensuration of anion concentration

Make water see through flat sheet membrane under these conditions, after the water before and after filtering is concentrated respectively, according to ICP-Ms (inductively coupled plasma mass spectrometry) method negatively charged ion is carried out qualitatively and quantitative, be converted into concentrated preceding concentration and try to achieve anion concentration (ppb).

(d) mensuration of concentration of metal ions

Make water see through flat sheet membrane under these conditions, according to the ICP-Ms method metal ion of the water before and after filtering is carried out qualitatively and quantitative, try to achieve concentration of metal ions (ppb).

Table 1

Annotate: (1) particle diameter less than 0.1 μ m.

(2) concentration is tried to achieve by particle collector.

(3) water is concentrated after, undertaken qualitative and quantitative by ion chromatography.

(4) carry out according to the ICP-Ms method qualitative and quantitative.

Table 2

Annotate: (1) measured value.Glycidyl converts.

(2) theoretical value.Glycidyl converts.

(3) particle diameter is less than 0.1 μ m.

(4) concentration is tried to achieve by particle collector.

(5) filtered water is concentrated after, undertaken qualitative and quantitative by ion chromatography.

(6) carry out according to the ICP-Ms method qualitative and quantitative.

As shown in Table 2, the hydrophilic composite microporous membrane of embodiment 1 is the thickness of 32.3 μ m, penetrates intensity, water-permeable, particulate simultaneously and removes ability, negatively charged ion and remove ability and positively charged ion to remove ability all excellent.Relative therewith, therefore the film of comparative example 1 does not have negatively charged ion to remove ability owing to do not have in the amino in primary～season any.Therefore the film of comparative example 2 does not have positively charged ion to remove ability owing to do not have sulfonic group.The film of comparative example 3, because thickness is almost 2 times of film of embodiment 1, so water-permeable is poorer.

Embodiment 2

(1) graft polymerization of glycidyl methacrylic acid

Microporous polyethylene film for similarly to Example 1 cleans similarly to Example 1, drying.The irradiation electron rays.For resulting irradiation film, except will being made as in the treatment time 15 minutes, the graft polymerization of GMA has been used in operation similarly to Example 1.Cut the part of resulting film, clean with methyl alcohol, drying calculates percentage of grafting by the quality change of the per unit area before and after the graft polymerization, and the result is 11 quality % when the microporous polyethylene film before the grafting is made as 100 quality %.This amount is scaled 0.77 milliequivalent/g with glycidyl.

(2) graft polymerization of methacrylic acid

With making GMA carry out film immersion that graft polymerization forms in the methanol solution (concentration 1 quality %) of methacrylic acid, under 50 ℃, carry out graft polymerization 40 minutes.Cut the part of resulting film, clean with methyl alcohol, drying is calculated the percentage of grafting of methacrylic acid by the quality change of the per unit area before and after the graft polymerization, the result is 11 quality % when the microporous polyethylene film before the grafting is made as 100 quality %.This amount is scaled 0.83 milliequivalent/g with carboxyl.

(3) the introducing operation of uncle's amino

Introducing there is the film of carboxyl under 50 ℃ temperature, impregnated in the IPA/ water mixed solvent (mass ratio: in the solution (concentration 10 quality %) of IPA/ water=11.1/88.9) 1 hour of dimethylamine, after the amine addition reaction on carrying out epoxy group(ing), clean with pure water.The part of this film be impregnated in the sodium hydroxide of 1N, dimethylamino is made the OH type, clean with pure water, after the drying, make the hydrochloric acid reaction of 1N, the HCl amount that consumes is carried out neutralization titration with alkali, thus, try to achieve the amine amount of introducing, the result is scaled 0.70 milliequivalent/g with dimethylamino.

(4) to the conversion reaction operation of quaternary ammonium group

Introducing there is the microporous polyethylene film of dimethylamino and carboxyl under 80 ℃ temperature, impregnated in the IPA solution (concentration 10 quality %) of Benzyl Chloride 15 minutes, carries out quaternized.Resulting film is cleaned with pure water, and drying obtains having the hydrophilic composite microporous membrane of quaternary ammonium group and carboxyl.

(5) average film thickness of resulting hydrophilic composite microporous membrane is 33.5 μ m, and Gas permeability is 120 seconds/100mL/20 μ m, and void content is 58.5%, and penetrating intensity is 225gf/20 μ m.

Embodiment 3

Except methacrylic acid is carried out the graft polymerization, operation similarly to Example 2, (with the quaternary ammonium base unit weight: dimethylamino is scaled 0.68 milliequivalent/g) to make microporous polyethylene film with quaternary ammonium group.The resulting microporous polyethylene film that contains quaternary ammonium group is carried with 0.3m/ minute speed with roller, and the power with 1.5kW is exposed in the plasma gas of generation under argon atmosphere simultaneously, forms carboxyl, obtains hydrophilic composite microporous membrane.Infrared spectra to resulting hydrophilic composite microporous membrane is measured, and the result is at 1720cm ^-1The place detects absorption peak, confirms to have introduced carboxyl.

Comparative example 4

Except only introducing on the microporous polyethylene film the carboxyl, hydrophilic composite microporous membrane is made in operation similarly to Example 2.

Comparative example 5

Except only introducing on the microporous polyethylene film the quaternary ammonium group, hydrophilic composite microporous membrane is made in operation similarly to Example 2.

Comparative example 6

Making is laminated with the hydrophilic composite microporous membrane of the film of comparative example 4 and 5.

Be produced on and be filled with the hydrophilic composite microporous membrane that obtains by embodiment 2,3 and comparative example 4～6 (flat sheet membrane of 5cm * 5cm) in the chassis respectively, use has the water of the composition shown in the table 3, in addition, under condition same as described above, carry out permeability test and filtration test.Show the result in table 4.

Table 3

Annotate: (1)～(4) are identical with table 1.

Table 4

Table 4 (continuing)

Annotate: (1) measured value.Dimethylamino converts.

(2) theoretical value.Carboxyl converts.

(3) by infrared measurement, at 1720cm ^-1The place detects absorption peak.

(4) particle diameter is less than 0.1 μ m.

(5) concentration is tried to achieve by particle collector.

(6) filtered water is concentrated after, undertaken qualitative and quantitative by ion chromatography.

(7) carry out according to the ICP-Ms method qualitative and quantitative.

As shown in Table 4, the hydrophilic composite microporous membrane of embodiment 2 is the thickness of 33.5 μ m, penetrates excellent strength simultaneously.In addition, embodiment 2 and 3 hydrophilic composite microporous membrane, its water-permeable, particulate are removed ability, negatively charged ion and are removed ability and positively charged ion to remove ability all excellent.Relative therewith, therefore the film of comparative example 4 does not have negatively charged ion to remove ability owing to do not have in the amino in primary～season any.Therefore the film of comparative example 5 does not have positively charged ion to remove ability owing to do not have carboxyl.The film of comparative example 6, because thickness is almost 2 times of film of embodiment 2 and 3, so water-permeable is poorer.

Claims (9)

1. a hydrophilic composite microporous membrane is characterized in that, has anion exchange groups and cation exchange group on arbitrary surface of the surface of thermoplastic resin micro-porous film system base material and pore internal surface.

2. hydrophilic composite microporous membrane according to claim 1, wherein, described anion exchange groups is the amino in primary～season and in the assorted cyclic amine residue any.

3. hydrophilic composite microporous membrane according to claim 1 and 2, wherein, described cation exchange group is any in sulfonic group and the carboxyl.

4. the manufacture method of each the described hydrophilic composite microporous membrane in the claim 1～3, it is characterized in that, after making unsaturated glycidyl compound carry out graft polymerization on the thermoplastic resin micro-porous film system base material, in the epoxy group(ing) of resulting polymkeric substance, introduce anion exchange groups and cation exchange group.

5. the manufacture method of each the described hydrophilic composite microporous membrane in the claim 1～3, it is characterized in that, make the unsaturated monomer that contains anion exchange groups and the unsaturated monomer and the thermoplastic resin micro-porous film system base material that contain cation exchange group carry out graft polymerization.

6. the manufacture method of each the described hydrophilic composite microporous membrane in the claim 1～3, it is characterized in that, (i) on thermoplastic resin micro-porous film system base material, make unsaturated glycidyl compound carry out graft polymerization, and in the epoxy group(ing) of resulting polymkeric substance, introduce after the anion exchange groups, make the unsaturated monomer that contains cation exchange group carry out graft polymerization on the base material of anion exchange groups containing; Or (ii) on thermoplastic resin micro-porous film system base material, make unsaturated glycidyl compound and the unsaturated monomer that contains cation exchange group carry out graft polymerization, and in the epoxy group(ing) of resulting polymkeric substance, introduce anion exchange groups.

7. the manufacture method of each the described hydrophilic composite microporous membrane in the claim 1～3, it is characterized in that, (i) on thermoplastic resin micro-porous film system base material, make unsaturated glycidyl compound and the unsaturated monomer that contains anion exchange groups carry out graft polymerization, and in the epoxy group(ing) of resulting polymkeric substance, introduce cation exchange group; Or (ii) on thermoplastic resin micro-porous film system base material, make unsaturated glycidyl compound carry out graft polymerization, and in the epoxy group(ing) of resulting polymkeric substance, introduce after the cation exchange group, make the unsaturated monomer that contains anion exchange groups carry out graft polymerization on the base material of cation exchange group containing.

8. the manufacture method of each the described hydrophilic composite microporous membrane in the claim 1～3, it is characterized in that, on thermoplastic resin micro-porous film system base material, make unsaturated glycidyl compound carry out graft polymerization, and in the epoxy group(ing) of resulting polymkeric substance, introduce after the anion exchange groups, base material enforcement plasma gas processing or the Corona discharge Treatment that contains anion exchange groups formed carboxyl.

9. the manufacture method of each the described hydrophilic composite microporous membrane in the claim 1～3, it is characterized in that, on thermoplastic resin micro-porous film system base material, make the unsaturated monomer that contains anion exchange groups carry out graft polymerization, and resulting base material enforcement plasma gas processing or the Corona discharge Treatment that contains anion exchange groups formed carboxyl.