JP3185109B2 - Microbial adsorption membrane - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microorganism adsorption membrane.
More specifically, the present invention relates to a microorganism-adsorbing film having a significantly improved microorganism-adsorbing ability by adhering a vinyl copolymer having excellent microorganism-adsorbing ability to the surface of a porous membrane.

[0002]

2. Description of the Related Art Conventionally, materials capable of filtering microorganisms such as bacteria, molds, algae, and protozoa existing in liquids and filtration of various solutions and liquids include polyolefin, polytetrafluoroethylene, and nylon. 66, a porous membrane having pores having a pore diameter of 0.1 to 10 μm and made of a resin such as cellulose has been known.

[0003]

However, the above-mentioned porous membrane has almost no bacteria and molds in a liquid or gas.
00% can be collected, but 0.001-0.
It was difficult to collect a virus having a size of 1 μm.

[0004] Further, since the above-mentioned porous membrane merely attaches microorganisms by physical adsorption force, the microorganisms are not chemically adsorbed and held, and are once collected on the porous membrane. There was a problem that the microorganisms that were removed easily dropped off.

The present invention has been made in view of such problems, and by improving the above-mentioned porous membrane, it is possible to efficiently collect even minute microorganisms such as viruses, for example. It is another object of the present invention to provide a microorganism adsorbing film having an excellent ability to adsorb microorganisms, which can adsorb and hold microorganisms so as not to easily fall off.

[0006]

In order to achieve the above-mentioned object, the invention described in claim 1 is defined as follows.

[0007]

Embedded image (Wherein, R ₁ is a benzyl group, a C ₄ -C ₁₆ alkyl group or a pentafluorophenylmethyl group, and X is a halogen atom). A water-insoluble or poorly water-soluble vinyl copolymer having a functional group represented by the following formula: But a microbial adsorption membrane characterized by being attached to the surface of a porous membrane. "

[0008] The invention according to claim 2 provides the microorganism adsorption membrane according to claim 1, wherein the porous membrane is made of a hydrophilic resin such as cellulose acetate or nitrocellulose. Was the gist.

The porous membrane in the present invention is not particularly limited, and the porous membrane conventionally used as a membrane filter, ie, having an average pore size of 0.1 to 10 is preferred.
A film having a thickness in the range of μm and a thickness in the range of 110 to 160 μm is preferably used. In particular, when collection of minute viruses is required, the average pore size is 0.005 to 0.005.
A 0.2 μm ultrafiltration membrane may be used.

The porous membrane may be made of a hydrophilic resin such as cellulose, nitrocellulose, cellulose acetate, or a polyolefin, polyamide,
Even if the membrane is made of hydrophobic resin such as polyacrylonitrile, the one that has been made hydrophilic by surface treatment such as sulfonation treatment, fluorine treatment, ultraviolet or radiation irradiation, corona discharge treatment, plasma treatment or coating with hydrophilic resin is as follows. It is preferred in terms of. That is, the vinyl copolymer described below, or the 4-vinylpyridine and the crosslinkable divinyl monomer constituting the vinyl copolymer, are coated on the surface of the porous film in the form of a solution dissolved in an organic solvent such as alcohols. Is given to For this reason, by using a porous film made of a hydrophilic resin, the affinity between the solution containing the vinyl copolymer or the 4-vinylpyridine or monovinyl monomer constituting the vinyl copolymer and the porous film is good. Become
The solution will spread all over the porous membrane.
In addition, the affinity with the vinyl pyridine unit constituting the vinyl copolymer is improved, and the adhesion strength of the vinyl copolymer is improved. Furthermore, by using a porous film made of a hydrophilic resin, the vinyl copolymer imparted to the porous film moves to the surface portion of the porous film with drying,
In other words, the so-called migration phenomenon of the vinyl copolymer in which the vinyl copolymer moves in the drying direction can be prevented. In addition, the pore diameter, porosity, shape, size, weight, etc. of the porous membrane can be freely selected according to the application and use condition. The vinyl copolymer is attached to the surface of the porous film.

The vinyl-based copolymer for the microorganism-adsorbing membrane of the present invention is obtained by copolymerizing 4-vinylpyridine with a monovinyl monomer and then reacting with a halide.
A vinyl copolymer represented by the following general formula can be used.

[0012]

Embedded image (Where R ₁ is a benzyl group, a C ₄ -C ₁₆ alkyl group or a pentafluorophenylmethyl group, R ₂ is a hydrogen atom or a C ₁ -C ₃ alkyl group, X is a halogen atom, Y is a hydrogen atom , alkyl group of C ₁ -C _3, a benzyl group, an ether group, a carboxyl group, a carboxylic acid ester group or an aryl group. in addition, the vinyl copolymer is a random copolymer or a block copolymer.

The vinyl copolymer is a conventionally known crosslinked polyvinylpyridinium halide (Japanese Patent Publication No. Sho 62).
Despite having the same excellent microorganism-adsorbing ability as described in JP-A-416441), it is insoluble or hardly soluble in water, but soluble in an organic solvent, and can be used as a solution. Since it is possible, processing such as impregnation or coating of another substrate (porous film), which is impossible with the conventional crosslinked polyvinylpyridinium halide, can be performed.

The monovinyl monomers used for the copolymerization include monoolefins such as ethylene, propylene and butene, styrene, vinyl acetate, acrylic acid, acrylic acid ester, methacrylic acid, methacrylic acid ester, aliphatic vinyl ester, acrylonitrile and the like. However, various derivatives can be used alone or in combination. However, when a monovinyl monomer having a highly hydrophilic functional group is used, the obtained copolymer becomes water-soluble depending on the degree of polymerization, which is not desirable.

Although the ratio of 4-vinylpyridine to monovinyl monomer, that is, the ratio of n: m, varies depending on the type of the monovinyl monomer used and the degree of polymerization, it is approximately 10:90 to 90:10. Desirably within the range. If the proportion of 4-vinylpyridine is smaller than this range, sufficient microorganism adsorption ability cannot be obtained, and if it is larger than this range, the obtained copolymer becomes highly water-soluble.
The vinyl copolymer has a degree of polymerization of at least 30.
Desirably, it is 0 or more. When the degree of polymerization is lower than 0, the resulting copolymer has high water solubility.

The copolymer of a monovinyl monomer and 4-vinylpyridine is reacted with a halide such as an alkyl halide, a benzyl halide, or a pentafluorophenylmethyl halide to quaternize pyridine, and represented by the following formula: Form the pyridinium group represented.

[0017]

Embedded image It is considered that the pyridinium group mainly functions to adsorb the microorganism while maintaining the active state. Although the mechanism is not clear, the pyridinium group is positively charged, and the cell surface of microorganisms is generally negatively charged. Therefore, it is estimated that electrostatic interaction is one important factor. You.

The vinyl copolymer thus obtained is substantially insoluble or hardly soluble in water and is soluble in an organic solvent. Utilizing this property, the vinyl copolymer is dissolved in an organic solvent to form a solvent solution. As the organic solvent, alcohols, esters, phenols, ethers, aromatic hydrocarbons and the like can be used, but it is preferable to use alcohols from the viewpoint of easy handling.

The solution in which the vinyl copolymer is dissolved is applied to the porous membrane by means such as impregnation and coating. After that, through a drying step, the vinyl copolymer is attached to the surface of the porous membrane.

The amount of the vinyl copolymer adhering to the porous membrane is not particularly limited. Powerful and economical. 2
When a large amount of the vinyl copolymer exceeding 0 wt% is attached, the adsorption effect is not improved even though the amount of the vinyl copolymer used is increased, which is uneconomical.

The vinyl copolymer in the present invention may be obtained by copolymerizing 4-vinylpyridine and a crosslinkable divinyl monomer on a porous film as shown below, in addition to the above vinyl copolymer. And those quaternized by halides can also be used.

The crosslinkable divinyl monomers used in this vinyl copolymer include divinylbenzene,
Examples include aromatic divinyl compounds such as divinyltoluene and divinylnaphthalene, and aliphatic divinyl compounds such as ethylene glycol diacrylate and ethylene glycol dimethacrylate. These crosslinkable divinyl monomers can be used alone or in combination of two or more.

The crosslinkable divinyl monomer and 4-vinylpyridine are applied to the porous membrane in the form of a solution. That is, a crosslinkable divinyl monomer and 4-vinylpyridine are added to an organic solvent such as alcohols, esters, phenols, ethers, and aromatic hydrocarbons to form a solution. A predetermined amount of a crosslinkable divinyl monomer and 4-vinylpyridine are applied to the surface of the porous film in a monomer state by immersing the porous film in the solution and impregnating the solution, or by coating the surface of the porous film. I do. Next, all or a part of the organic solvent is removed, and the crosslinkable divinyl monomer and 4-vinylpyridine are attached to the surface of the porous membrane. The ratio of the crosslinkable divinyl monomer to 4-vinylpyridine attached to the surface of the porous membrane is desirably 15 mol% or less, and if it exceeds this, the adsorptive power of microorganisms decreases. The amount of the vinyl copolymer adhering to the porous membrane is not particularly limited, but those having an amount of the vinyl copolymer in the range of 0.01 to 20 wt% with respect to the microorganism adsorbing film have a high microorganism adsorbing power. , And economical. Also,
Conventional radical initiators such as benzoyl peroxide and azobisisobutyronitrile are added to the solution containing each monomer. Further, a reactive vinyl monomer such as styrene or methyl methacrylate may be added to the solution containing each monomer.

The crosslinkable divinyl monomer and 4-vinylpyridine thus adhered to the surface of the porous membrane in a monomer state are copolymerized under heating. The polymerization is carried out at 50 to 100 ° C. under normal pressure or under pressure.

The resulting copolymer is reacted with a halide such as an alkyl halide, a benzyl halide or a pentafluorophenylmethyl halide to quaternize pyridine to give a vinyl copolymer having a pyridinium group. Is obtained. The amount of the halide used is appropriately determined according to the content of the 4-vinylpyridine unit in the copolymer.

The vinyl copolymer thus obtained is substantially insoluble or hardly soluble in water and an organic solvent, and the vinyl copolymer described in JP-B-62-41641 is used. Show similar properties. In addition, since the vinyl copolymer is attached to the surface of the porous membrane in the form of a monomer and is copolymerized on the porous membrane, the surface area per unit weight of the vinyl copolymer increases. However, the efficiency of adsorbing microorganisms is dramatically improved.

As described above, two preferred examples of the vinyl copolymer used for the microorganism adsorption membrane of the present invention have been described.
Having a halogenated pyridinium group in the molecule that exhibits excellent microorganism adsorption ability, water so that the vinyl copolymer is not eluted in the liquid to be collected or filtered and sterilized by microorganisms. If it is a vinyl copolymer having the requirements that it is insoluble or hardly soluble in water, and that it can be easily processed by impregnation or coating of a porous membrane, it is limited to this. is not.

The microorganisms to be adsorbed by the microorganism adsorbing membrane of the present invention include bacteria, molds, algae, viruses and the like.

The experiments by the present inventors have revealed that the vinyl copolymer of the present invention requires water in order to sufficiently exhibit the microorganism-adsorbing ability, which is a characteristic of the vinyl copolymer. . Therefore, when the microorganism adsorption membrane of the present invention is used in a gas phase, together with a vinyl copolymer, calcium chloride, alkaline earth metal salts such as magnesium chloride or lithium chloride, potassium metasilicate, titanium sulfate or the like is used. A deliquescent substance, a water-soluble polymer such as polyvinyl alcohol, polyacrylate, vinylpyrrolidone, or a humectant such as silica gel, zeolite, collagen, diphosphorus pentoxide, magnesium oxide, ethylene glycol, etc. It is attached to. As a result, the microorganism-adsorbing film exhibits excellent microorganism-adsorbing ability as in the case of an aqueous system.

When the microorganism-adsorbing film of the present invention is used only for removing microorganisms, if a bactericide is attached to the surface of the porous film together with the vinyl copolymer of the present invention, It is possible to obtain a microorganism adsorbing film having a bactericidal performance as well as a microorganism adsorbing ability. Examples of the bactericide include antibiotic polymyxin, positive surfactants such as quaternary ammonium salts, amphoteric surfactants such as alkylaminoethylglycine, chlorhexidine, piguanides such as polyhexamethylenepiguanidine, and undecylenic acid. Higher fatty acids, metals and metal ions, phenols and the like can be used. In particular, when it is desired that the bactericide be water-insoluble, an antibacterial zeolite in which zeolite is replaced with a bactericidal metal ion, a pigment such as polyvinyl, polyacrylate, polyester, or polyamide is used as a guanide or quaternary ammonium salt. And a silicone-type immobilized bactericide such as 3- (trimethoxysilyl) -propyltrimethyloctadecyl ammonium chloride.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to embodiments. Example 1 After copolymerizing 4-vinylpyridine and styrene at a ratio of 30:70 mol, the vinyl copolymer having a pyridinium group was obtained by quaternizing with 4-vinylpyridine and equimolar benzyl bromide. Obtained.

An ethanol solution in which the vinyl copolymer was dissolved was used to form a film having pores having an average pore diameter of 0.45 μm and a thickness of 1 μm.
After impregnating a porous membrane composed of 45 μm nitrocellulose, it was dried at 75 ° C. to obtain a microorganism-adsorbed membrane having an adhesion of the vinyl copolymer to the porous membrane of 0.2% by weight. After setting the microorganism adsorption membrane in an ultrafiltration apparatus having an inner diameter of 42 mm, T-4 bacterial phage was added to the apparatus in 2.79 × 10 ⁷ PFU in 0.85% sterilized saline.
/ Ml of the liquid suspended at a concentration of / ml was connected to a nitrogen cylinder, and filtration was performed while applying a pressure of 0.5 kg / cm ² . The amount of T-4 bacterial phage in the filtrate was measured by the PFU (Planck Forming Unit) method, and the removal rate was determined and is shown in Table 1. In addition, the same experiment was carried out also on a laminate of three of the above-mentioned microorganism adsorbing films, and the removal rate was obtained and shown in Table 1.

Comparative Example 1 The same procedure as in Example 1 was carried out except that the vinyl copolymer was not used, and only a porous membrane made of nitrocellulose having a pore size of 0.45 μm and a film thickness of 145 μm was used. By way of T-
Four bacterial phages were removed and the removal rates were determined and are shown in Table 1.

[0034]

[Table 1]

Example 2 3 g of 4-vinylpyridine, 0.05 of divinylbenzene
g, azobisisobutyronitrile 0.03 g and toluene 300 ml were placed in a reaction vessel. In this vessel, a porous membrane composed of cellulose acetate having pores with an average pore diameter of 0.2 μm and a film thickness of 125 μm was used. Was immersed. Thereafter, toluene is evaporated at room temperature to attach 4-vinylpyridine, divinylbenzene, and azobisisobutyronitrile to the surface of the porous film. After this, 80
It is left in a thermostat at a temperature of 5 ° C. for 5 hours to copolymerize 4-vinylpyridine and divinylbenzene on the porous membrane.

Next, the porous membrane having the copolymer adhered to the surface is placed in a reaction vessel, and benzyl bromide and toluene are added to the vessel and reacted at 80 ° C. for 6 hours for quaternization to obtain a pyridinium group. Thus, a microorganism-adsorbed film in which a vinyl-based copolymer having the above was adhered to the surface of the porous film was obtained. The adhesion rate of the vinyl copolymer to the adsorption film was 2.0% by weight. After setting this microorganism adsorption membrane in an ultrafiltration device having an inner diameter of 42 mm, 0.85% of T-4 bacterial phage was added to this device.
25 ml of a solution suspended at a concentration of 2.79 × 10 ⁷ PFU / ml in sterile sterilized saline was connected to a nitrogen cylinder, and filtration was performed while applying a pressure of 0.5 kg / cm ² . . Determine the amount of T-4 bacterial phage in the filtrate by PFU
(Planck forming unit) The removal rate was determined by the method and shown in Table 2.

COMPARATIVE EXAMPLE 2 An average pore diameter of 0.2 μm without adhering a vinyl copolymer
T-4 bacterial phage were removed in the same manner as in Example 2 using only a porous membrane made of cellulose acetate having a thickness of 125 μm and having a thickness of 125 μm. Was.

[0038]

[Table 2]

[0039]

According to the present invention, the above-mentioned structure is provided.
The microorganism adsorbing film of the described invention has a significantly improved microorganism adsorbing ability by attaching a vinyl copolymer having excellent microorganism adsorbing ability to the surface of the porous membrane, and for example, has a very small Even microorganisms can be efficiently collected.

In the microorganism-adsorbing film according to the first aspect of the present invention, the microorganism is easily adsorbed and held on the microorganism-adsorbing film by the vinyl copolymer adhered to the surface of the porous film. Never fall off.

Further, in the microorganism adsorption membrane according to the second aspect, by using a porous membrane made of a hydrophilic resin,
Vinyl copolymer or 4 constituting vinyl copolymer
-The affinity between the solution containing vinyl pyridine and monovinyl monomer and the porous membrane is improved, and the solution can be spread all over the porous membrane. Further, the affinity with the vinyl pyridine unit constituting the vinyl copolymer is improved, and the adhesion strength of the vinyl copolymer can be improved. Further, by using a porous film made of a hydrophilic resin, the migration phenomenon of the vinyl copolymer can be prevented.

Claims (2)

(57) [Claims] [Claim 1] (Wherein, R ₁ is a benzyl group, a C ₄ -C ₁₆ alkyl group or a pentafluorophenylmethyl group, and X is a halogen atom). A water-insoluble or poorly water-soluble vinyl copolymer having a functional group represented by the following formula: Is attached to the surface of a porous membrane. 2. A porous membrane microorganisms adsorbed film according to claim 1, characterized in that it is constituted by a parent aqueous resins such as cellulose acetate and nitrocellulose.