JPH0386730A - Ion-exchanging porous material and its production - Google Patents

Abstract

PURPOSE:To improve the dimensional stability, permeabilities, etc., by supplying a monomer having (a structure convertible to) an ionizing group to a porous substrate material in a gas phase, then supplying a substance capable of forming a salt with the monomer to the substrate material, and reacting the monomer with the substance. CONSTITUTION:A porous substrate material pref. having a thickness of 5mum to 5mm and a pore content of 10-90% is supplied with a monomer having (a structure convertible to) an ionizing group, if necessary with another monomer copolymerizable therewith, to thereby cause the substrate material to carry a high-molecular compd. comprising the monomer, if necessary with said another monomer, and is then supplied with a substance capable of forming a salt with the monomer, and thus the monomer and the substance are reacted to give an ion-exchanging porous material having a thickness of 5mum to 5mm, a water permeability (FG) of 1.0ml/min.m<2>.mmHg or higher, a pore content of 10-90%, and a ratio of the water permeability of the substrate material (FB) to FG of 0.7 or higher.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an ion-exchange porous material and a method for producing the same. Specifically, the present invention provides an excellent ion-exchangeable porous body that exhibits various functions based on ion-exchange groups introduced into a porous substrate, such as selective separation ability due to electrostatic interaction, and a method for producing the same. It is related to.

(Prior Art) Porous bodies exhibiting ion exchange properties are used in various applications as functional materials such as materials for selective separation and materials for cell culture.

By the way, as a method for producing such an ion-exchangeable porous body, conventional methods include (a) a method of molding a porous body using a substance with ion-exchangeability as a constituent component (for example, Japanese Patent Laid-Open No. 6
0-7856), (b) a method of attaching a substance having ion exchange properties to a porous membrane substrate (for example, JP-A No. 6
(Refer to No. 2-57613, JP-A-64-80402)
, and (c) a method of graft polymerizing a monomer having ion exchange properties onto a porous membrane substrate (for example, JP-A-61-2
No. 20705, JP-A No. 62-83006), etc. are known.

(Problem to be solved by the invention a) However, the ion-exchangeable porous body obtained by the method (a) of forming a porous body using a substance having ion-exchange properties as a constituent component has a porous membrane base material. Because it is made with an ionically dissociable group, it easily absorbs water and swells in an aqueous solution.

In addition, (b) a method of attaching a substance that has ion exchange properties to a porous membrane base material or C) a method of graft polymerizing a monomer having ion exchange properties to a porous membrane base material has conventionally been used.
In both cases, the reaction proceeded in a liquid phase using a solvent. As described above, using a solvent during the reaction has problems in terms of operability, economy, safety, etc.
Furthermore, since the base material is porous, during graft polymerization or ionization reactions in a solvent, the diffusion of reagents into the pores is slow, making it difficult to provide high ion exchange properties and permeability. Ta.

Therefore, an object of the present invention is to provide a novel ion-exchange porous body and a method for producing the same. The present invention also provides an ion-exchangeable porous material that has excellent dimensional stability, permeability, etc., and that exhibits various functions including high ion-exchange ability based on ion-exchange groups introduced into the porous base material. The purpose of this invention is to provide a manufacturing method thereof. A further object of the present invention is to provide a method for producing an ion-exchange porous material that is excellent in operability, economic efficiency, and stability.

(Means for Solving the Problems) The above-mentioned solution includes supplying an ion-dissociable group or a monomer having a structure convertible to an ion-dissociable group as at least one component in a gas phase to the porous substrate. , characterized in that a polymer compound having at least one component of the monomer is held in a porous base material, and then a substance capable of forming a salt with the monomer is supplied in a gas phase and reacted with the polymer compound. This is achieved by using an ion exchange porous material.

The present invention also has a thickness of 5 μm to 5 mm and a water permeation rate of 1 ml.
/min-m2 ・mmHg or more, porosity 10-90
%. The present invention further provides that the relationship between the water permeation rate (F B) of the porous base material and the water permeation rate (F G) of the porous body after imparting ion exchange properties is F B/F Ga4.7.
This shows the ion exchange porous material. The present invention also provides an ion exchange method in which the combination of a monomer having an ion-dissociable group or a structure convertible to an ion-dissociable group and a substance capable of forming a salt with the monomer is a nitrogen-containing compound and a halide. This indicates a porous material.

In some aspects of the above, at least one component of a monomer having an ion-dissociable group or a monomer having a structure convertible into an ion-dissociable group is supplied to the porous substrate, and at least one of the monomers is supplied to the porous substrate in a gas phase. An ion-exchangeable pore characterized by comprising a step of holding a polymer compound as a constituent component in a porous base material, and a step of supplying and reacting a substance capable of forming a salt with the monomer in a gas phase. The present invention, which is also achieved by a method for producing a polymeric body, also includes a step of generating a polymerization initiation point on the surface of a porous substrate, and a monomer that has an ionically dissociable group or a structure that can be converted into an ionically dissociable group. is supplied as at least one component, and a step of growing a graft chain having at least one component of the monomer from the polymerization initiation point, and a step of supplying and reacting a substance capable of forming a salt with the monomer. This shows a method for producing an ion-exchangeable porous material, characterized in that each step is carried out in a series of dry processes under reduced pressure.

(Function) In this way, in the present invention, the ion dissociative group is not introduced into the porous substrate itself, but is introduced into the surface thereof, so that it does not swell significantly in an aqueous solution. °Legal quality is excellent.

Furthermore, the present invention provides a monomer composition comprising at least one component of a monomer having an ionically dissociable group or a monomer having a structure convertible to an ionically dissociable group, and a substance capable of forming a salt with the monomer. Since they are each supplied in a gas phase and reacted to impart ion exchange properties, salt-type ion exchange groups are efficiently imparted to the pore surfaces inside the porous body.

In addition, since ion exchange groups are efficiently imparted to the pore surfaces inside the porous body in this way, for example, the water permeation rate (F B) of the porous base material and the porous body after imparting ion exchange properties The relationship between FB/FG and water permeation rate (FG) is FB/FG≧0.
7, the permeation performance of the porous base material is maintained at a high level.

Furthermore, a monomer having an ion-dissociable group or a structure convertible to an ion-dissociable group is supplied as at least one component in the gas phase, and a polymer compound having at least one component of the monomer is formed into a porous structure. By separately providing a step of holding the monomer in a solid base material and a step of supplying and reacting a substance capable of forming a salt with the monomer in a gas phase, it is possible to form a salt such as a tetraalkylammonium structure. This makes it possible to easily introduce type ion exchange groups onto the surface of the porous substrate. In other words, monomers having salt-type ion exchange groups generally have large molecular weights and low vapor pressures, so it is difficult to supply them in the gas phase and carry out graft polymerization or plasma polymerization. This is because it is difficult to directly introduce a salt-type ion-exchange group onto the surface of a porous substrate using a monomer that forms the salt-type ion-exchange group.

Hereinafter, the present invention will be explained in more detail based on embodiments.

The ion-exchangeable porous material of the present invention is produced by supplying an ion-dissociable group or a monomer having a structure convertible to an ion-dissociable group as at least one component in a gas phase to a porous base material. The method is characterized in that a polymer compound having at least one component of the monomer is held in a porous base material, and then a substance capable of forming a salt with the monomer is supplied in a gas phase and reacted with the polymer compound. It is something to do.

The porous base material used in the present invention is not particularly limited in shape as long as it has a porous structure. Porous substrates may be in the form of lumps or particles such as However, in order to ensure sufficient physical strength and ion exchange ability, the thickness should be 5 μm to 5 mm, more preferably 10 μm to 1 mm,
It is desired that the porosity is 10 to 90%, more preferably 30 to 85%. Further, the material thereof is not particularly limited, and various materials can be used, but it is preferably a material that does not swell with water. In other words, if such a base material that does not swell with water is used, there is a risk of problems such as swelling with water during use, opening the flow path, and reducing water permeability. This is because there are few. Note that for water,
A "non-swellable" base material refers to a base material whose dimensional change (swelling) rate in the longitudinal direction is 5% or less when a strip-shaped sample of 1xlOcm is immersed in distilled water for 24 hours. Examples of such base materials include cellulose derivatives, polyethylene, polypropylene, polystyrene, polymethyl methacrylate, polycarbonate, polyurethane, polyvinyl chloride, polyvinyl bromide, polyethylene terephthalate, polyamide, polytetrafluoroethylene, polyvinylidene chloride, polysulfone, etc. These include thermoplastic resins, copolymers, and blends thereof. Among these, base materials whose main components are polyolefins with excellent mechanical strength and chemical resistance and polyolefins in which some or all of the hydrogen has been replaced with halogens are particularly preferred.

The combination of an ion-dissociable group or a monomer having a structure convertible to an ion-dissociable group and a substance capable of forming a salt with the monomer that can be used in the present invention includes the ion exchange to be obtained. Various types can be used depending on the type of group, that is, strong basic anion salt type, weak basic anion salt type, strong acid cation salt type, weak acid cation salt type, etc. For example, when trying to form a strongly basic anion salt type ion exchange group, secondary to tertiary
Examples include a combination of a primary amine nitrogen-containing compound monomer and a halide, or conversely a combination of a halogen-containing monomer and a tertiary amine.

In these combinations, the imino group or nitrogen atom of the secondary or tertiary amine easily reacts with the halogen,
It becomes a strongly basic quaternary ammonium salt.

As the secondary to tertiary amine nitrogen-containing compound monomer, monomers having a nitrogen-containing heterocycle in the molecule are particularly preferred, and specific examples include vinylpyridine, vinylpyrimidine, and vinylpyrazole. , vinylpyrazoline, vinylimidazole, vinylimidacillin, vinylpyrrolidone, vinyloxazoline, vinylpiperidone, vinylacridine, N-vinyl-N,N'-)rimethyleneurea, vinyluracil, vinylthymine, vinylquinoline, vinylacridine, vinyladenine, Examples include vinylhyboxanthin, vinylguanine, 5-methyl-2-vinylimidacylindyl, N-vinylthymine, imide, and N-vinylsuccinimide.

In addition, halides that react with these include benzyl chloride, benzyl bromide, butyl bromide,
Examples include butyl chloride.

Furthermore, examples of the halogen-containing monomer include chloromethylstyrene, bromomethylstyrene, chlorobutyl methacrylate, etc., while tertiary amines that react with these halogen-containing monomers include trimethylamine, triethylamine, etc. , pyridine, pyrimidine, pyrazine, triazine, quinoline, acridine and the like.

However, the present invention is not limited to these exemplified compounds, but includes secondary to tertiary compounds.
aminic nitrogen-containing compound monomers and halides,
Alternatively, as the halogen-containing monomer and tertiary amine, it is of course possible to use various other monomers other than these.

Furthermore, in the ion-exchangeable porous material of the present invention, the above-mentioned ion-dissociable group or a monomer having a structure convertible to an ion-dissociable group is supplied as at least one component in a gas phase. In bonding a polymer compound having at least one constituent component to a porous substrate surface, the polymer compound is a monomer having an ion-dissociable group or a structure convertible to an ion-dissociable group as described above. Even if it is a homopolymer based on the ion-dissociable group or a monomer having a structure that can be converted into an ion-dissociable group or an ion-dissociable group, it is possible to convert into these ion-dissociable groups or ion-dissociable groups. It may be a random or block copolymer formed by combining a monomer having a similar structure with a plurality of other copolymerizable monomers.

Other monomers that can be copolymerized with these ionically dissociable groups or monomers having structures convertible to ionically dissociative groups include, for example, acrylic acid, methyl acrylate, ethyl acrylate, isopropyl acrylate, and butyl acrylate. methacrylic acid, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, butyl methacrylates, 2-hydroxyethyl acrylate, 2-hydroxy methacrylate, acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, vinyl acetate, styrene, etc. Of course, it is not limited to these.

In the ion-exchangeable porous material of the present invention, a monomer composition containing at least one component of a monomer having an ion-dissociable group or a monomer having a structure convertible to an ion-dissociable group, and Substances that can form salts with the porous body are supplied in the gas phase and reacted to impart ion exchange properties, so salt-type ion exchange groups are efficiently imparted to the pore surfaces inside the porous body. As a result, high water permeability can be obtained, but when considering the application to various scale filters such as microorganism trapping materials, the water permeation rate is 1.
0 ml/min-m2*mmHg mmHg]-1 or 100 ml/min-m2-mmHg or more is desired as an indicator of permeability. Furthermore, between the water permeation rate (F B) of the porous base material and the water permeation rate (FG) of the porous body after imparting ion exchange properties, FB/FG≧
0.7, more preferably FB/FG≧0.8.

The method for producing an ion-exchangeable porous material of the present invention includes adding at least one component of an ion-dissociable group or a monomer having a structure that can be converted into an ion-dissociable group to a porous base material in a gas phase. a step of supplying a substance capable of forming a salt with the monomer in a gas phase to cause the porous substrate to hold a polymer compound having at least one constituent component of the monomer; and a step of supplying a substance capable of forming a salt with the monomer in a gas phase to react It is characterized by having the following. The manufacturing method of the present invention may include such two steps, and there is no problem even if there are other steps such as a pre-treatment step or a post-treatment step before and after the two steps.

In the method for producing an ion-exchangeable porous material of the present invention, at least one constituent component is added to the surface of a porous base material, such as the above-mentioned ion-dissociable group or a monomer having a structure convertible to an ion-dissociable group. The method for retaining the polymer compound is not particularly limited as long as these monomer components can be supplied in the gas phase.
Preferred examples include plasma surface graft polymerization and plasma polymerization.

Furthermore, the method for producing an ion-exchange porous material of the present invention includes a step of generating a polymerization initiation point on the surface of a porous substrate, and a step of forming an ion-dissociable group or a structure convertible into an ion-dissociable group.
a step of supplying a monomer as at least one component and growing a graft chain having the monomer as at least one component starting from the polymerization initiation point, and forming a salt with the monomer. Preferably, each step is performed in a series of dry processes under reduced pressure. In addition, such a polymerization initiation point capable of graft polymerization can be used to generate polymer radicals on the surface of a porous substrate if the monomer has a double bond in the molecule and is capable of radical polymerization. Bye. Methods for generating polymer radicals include electron beams, gamma rays, ultraviolet rays, plasma, ozone, and radical generating agents (hydrogen abstracting agents). A series of steps in which a substance capable of forming a salt with the monomer is supplied in a gaseous state to proceed with surface graft polymerization by solid-gas phase polymerization, and a salt is formed by a solid-gas phase reaction in a series of steps. This is dangerous because the dry process becomes more viable for containers.

(Example) Hereinafter, the present invention will be explained in more detail with reference to Examples.

Examples 1-4 Melt flow index (M, 1.) is 30 and 0
．． 3 polypropylene (mixture of weight ratio 100:60)
Per 100 parts by weight, liquid paraffin (
1. As a number average molecular weight ff1324)435 and a crystal nucleating agent. 3. 2゜0.2 parts by weight of 4-bis(p-ethyldibenzylidene) sorbitol was added to a twin-screw extruder (
(manufactured by Ikedada Tekko Co., Ltd.) to form a pellet, melt it at 150 to 200°C using the extruder described above, push it into the air through a T-die with a slit width of 0.6 m + m, and extrude it.
The guide roller of the cooling liquid phase placed directly below the T-die rotates to lead to the cooling solidification liquid Φ, which is cooled and solidified, and then wound up.

The wound film material was cut to a certain length, fixed in both vertical and horizontal axes, and placed in 1,1,2-)lichloro-1,2,2-)lifluoroethane for 10 minutes for a total of 41 minutes! d immersion to extract liquid paraffin, and then in air at 135°C for 2 hours.
The maximum pore diameter was 0.45 μm and the membrane was 480 μm.
A polypropylene porous body having a porosity of 66% and a water permeation rate of 21 ml/min was obtained.

The polypropylene porous body thus obtained was placed in a vacuum reaction vessel and heated with low temperature plasma (Ar O, 1t
orr) for 15 seconds, a monomer raw material containing at least one component an ion-dissociable group or a monomer having a structure convertible to an ion-dissociable group shown in Table 1 was added to the gaseous state (Gas 1). The surface graft polymerization was carried out at a temperature of 288 °C for 10 minutes. Subsequently, after removing unreacted monomers, a substance capable of forming a salt with the ionically dissociable group or the monomer having a structure convertible to an ionically dissociable group is added in gaseous form (gas 2). The mixture was supplied and reacted under reduced pressure for 20 minutes to obtain a quaternary ammonium salt type ion exchange porous material.

Regarding the ion exchange porous body obtained in this way,
The water permeation rate and microbial trapping ability were investigated. Second result
Shown in the table.

Example 5 A polypropylene porous body similar to that used in Example 1 was placed in a vacuum reaction vessel, and plasma polymerization was performed for 5 minutes under reduced pressure using vinylpyridine as a monomer. Subsequently, unreacted monomers were removed under reduced pressure, and then benzyl chloride was supplied in gaseous form and reacted at 5.0 torr for 10 minutes to obtain a quaternary ammonium salt type ion exchange porous material.

Regarding the ion exchange porous body obtained in this way,
The water permeation rate and microbial trapping ability were examined in the same manner as in Example 1. The results are shown in Table 2.

Example 6 A polyvinylidene fluoride porous membrane having a pore diameter of 0.45 μm, a film thickness of 80 μm, and a porosity of 72% was surface graft-polymerized with 2-vinylpyridine in the same manner as in Example 1, and then quaternized with benzyl chloride. A quaternary ammonium salt type ion-exchange porous material was obtained.

Regarding the ion exchange porous body obtained in this way,
The water permeation rate and microbial trapping ability were examined in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 1 A polypropylene porous body similar to that used in Example 1 was subjected to surface graft polymerization of methoxyethyl acrylate using the same method as in Example 1.

Regarding the surface-grafted porous body thus obtained, the water permeation rate and microbial trapping ability were examined in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 2 A polyvinylidene fluoride porous membrane similar to that used in Example 6 was coated with 2% by weight water-methanol (1 :1 [volume ratio] After 2 minutes of immersion in the solution, the water permeation rate and microbial trapping ability were examined in the same manner as in Example 1. The results are shown in Table 2.

Table 1 Table 2 Water permeation rate 8 Bacteriophage removal rate (%).

As is clear from the results shown in Table 2, all of the ion-exchange porous materials according to the present invention (Examples 1 to 6) exhibit excellent dimensional stability without swelling even when immersed in water. In addition, the water permeation rate was comparable to that of the porous base material (01).In addition, the ion exchange porous materials according to the present invention (Examples 1 to 6) ,
By forming and introducing a quaternary ammonium salt type ion exchange group, the ion dissociation property was enhanced and the material was converted into a hydrophilic porous material that was easily wetted with water. Furthermore, the ion-exchange porous materials according to the present invention (Examples 1 to 6) were also excellent in removing microorganisms, and all removed 99.99% or more of bacteriophages.

In addition, each characteristic value mentioned in this specification was measured as follows.

(1) Thickness Measured using a micrometer.

(2) Porosity (%) The pores of the porous body are hydrated with distilled water (if the porous body is hydrophobic, hydrated using alcohol-water displacement), and the weight when hydrated is determined. (Ww) is measured. When the dry weight is Wd and the density of the polymer is P [g/ml], the porosity (P) is calculated by the following formula.

After punching out the porous body to a diameter of 43 mm and fixing it in a holder, water at 25°C was permeated under a pressure of 0.7 [kg/cm2], and the water permeation rate per unit time was FW [ml/mi].
nm2·mmHg] was calculated.

(4) Bacteriophage removal rate (microbial capture ability) A porous body was punched out to a diameter of 25 mm, and a solution containing bacteriophages (approximately 105 cells/ml) was filtered through this porous body, and then the filtrate was collected using the plaque method. The bacteriophage contained was quantified and the removal rate was calculated.

Removal rate (%) = (1-'in liquid+D7y-'number)X10
00,000τ Kamoka Tamari ``In addition, we conducted experiments using bacteriophages T4 and T7 as bacteriophages.

(Effect of the invention) As described above, the ion exchange porous body of the present invention has
A monomer containing an ion-dissociable group or a monomer that has a structure convertible to an ion-dissociable group as at least one component is supplied to the porous substrate in a gas phase to form a polymer containing the monomer as at least one component. It is characterized by the fact that a molecular compound is held in a porous base material, and then a substance that can form a salt with the monomer is supplied in a gas phase and reacted with it, so it has excellent dimensional stability and permeability. In addition to exhibiting excellent ion exchange ability based on the ion exchange groups introduced into the porous substrate, it also exhibits various functions. For example, it can be used as a selective separation phase in microorganism removal membranes and blood filters. Alternatively, it can be suitably applied as a base for bioreactors. Furthermore, in the ion exchange porous membrane of the present invention,
Polishing 5 μm ~ 5 mm, water permeation rate 1 ml/min-m2
mmHg or more, the porosity is 10 to 90%, and the water permeation rate of the porous base material (F B
) and the water permeation rate (F Become.

The present invention further provides at least one component of a monomer having an ion-dissociable group or a monomer having a structure convertible into an ion-dissociable group, which is supplied to the porous substrate in a gas phase. Ion-exchange properties characterized by comprising a step of holding a polymer compound serving as a constituent component in a porous base material, and a step of supplying and reacting a substance capable of forming a salt with the monomer in a gas phase. This is a method for producing porous materials.1-.Not only can it easily provide an ion-exchangeable porous material with the excellent properties listed below, but it is also a dry process that does not use a solvent. There is no risk of accidents due to fire or toxicity, and it is economical because each raw material is supplied in gaseous form and consumed efficiently, and it is also easy to operate because it is carried out in a series of dry processes. It is something that Furthermore, the method for producing an ion-exchangeable porous material of the present invention includes a step of generating a polymerization initiation site on the surface of a porous substrate, and a step of generating an ion-dissociable group or a monomer having a structure convertible to an ion-dissociable group. A step of supplying the monomer as at least one component and growing a graft chain having the monomer as at least one component from the polymerization initiation point, and supplying a substance capable of forming a salt with the monomer and reacting. If each step is performed in a dry process under a series of reduced pressures, the operability will be further improved.

Claims (5)

[Claims] (1) Supplying an ionically dissociable group or a monomer having a structure convertible to an ionically dissociable group as at least one component in a gas phase to a porous substrate, and supplying the monomer as at least one component. 1. An ion-exchangeable porous material characterized in that it is formed by holding a polymer compound in a porous base material, and then supplying a substance capable of forming a salt with the monomer in a gas phase to react with the monomer. (2) Thickness 5 μm to 5 mm, water permeation rate 1.0 ml/m
The ion-exchangeable porous body according to claim 1, having a porosity of in·m^2·mmHg or more and a porosity of 10 to 90%. (3) Claim 1 or 2, wherein the relationship between the water permeation rate (FB) of the porous base material and the water permeation rate (FG) of the porous body after imparting ion exchange properties is FB/FG≧0.7. 2. The ion-exchange porous body according to 2. (4) The combination of a monomer having an ionically dissociable group or a structure convertible to an ionically dissociative group and a substance capable of forming a salt with the monomer is a nitrogen-containing compound and a halide. 3. The ion exchange porous body according to any one of 3. (5) Supplying an ionically dissociable group or a monomer having a structure convertible to an ionically dissociable group as at least one component in a gas phase to the porous substrate, and supplying the monomer as at least one component. An ion-exchangeable porous body characterized by comprising a step of holding a polymer compound in a porous base material, and a step of supplying a substance capable of forming a salt with the monomer in a gas phase and reacting the same with the monomer. Production method. (6) A step of generating a polymerization initiation point on the surface of the porous substrate, and supplying as at least one component a monomer having an ion-dissociable group or a structure convertible to an ion-dissociable group, and A step of growing a graft chain having at least one constituent component from the polymerization initiation point, and a step of supplying and reacting a substance capable of forming a salt with the monomer, and each step involves a series of reduced pressure steps. Claim 5 characterized in that the process is carried out in a dry process below.
A method for producing an ion-exchangeable porous material as described in .