JPH04252186A - Microorganism adsorbing membrane - Google Patents

Abstract

PURPOSE:To obtain the title adsorbing membrane useful for collecting viruses, etc., having excellent adsorbability by adhesively bonding a water-insoluble vinyl copolymer containing a specific functional group to the surface of porous membrane. CONSTITUTION:A water-soluble or slightly water-soluble vinyl-based copolymer containing a functional group shown by the formula (R1 is benzyl, 4-16C alkyl or pentafluorophenylmethyl; X is halogen), for example, obtained by copolymerizing 4-vinylpyridine with a monovinyl monomer and treating with a halide is adhesively bonded to the surface of a porous membrane (preferably 0.1-10mum average pore diameter and 110-160mu membrane thickness) such as cellulose acetate to give the objective adsorbing membrane. The amount of the vinyl copolymer added is preferably 0.01-20wt.% based on the adsorbing membrane.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microbial adsorption membrane. More specifically, the present invention relates to a microbial adsorption membrane whose microbial adsorption capacity is dramatically improved by attaching a vinyl copolymer having an excellent microbial adsorption capacity to the surface of the porous membrane.

0002

[Prior Art] Conventionally, materials that can filter various solutions and gases and collect microorganisms such as bacteria, mold, algae, and protozoa present in liquids include polyolefin, polytetrafluoroethylene, and nylon. 66, a porous membrane made of resin such as cellulose and having pores with a pore diameter of 0.1 to 10 μm has been known.

0003

[Problems to be Solved by the Invention] However, the porous membrane described above has almost no bacteria or fungi in the liquid or gas.
Although it is possible to collect 0.00%, 0.001 to 0.00% can be collected.
It was difficult to collect viruses with a size of 1 μm.

[0004] Furthermore, since the above-mentioned porous membrane only allows microorganisms to adhere to it through physical adsorption, the microorganisms are not chemically adsorbed and retained, but are once collected on the porous membrane. There was a problem in that the microorganisms that were removed easily fell off.

The present invention was made in view of these problems, and by improving the above-mentioned porous membrane, even microscopic microorganisms such as viruses can be efficiently collected. The object of the present invention is to provide a microorganism adsorption membrane having excellent microorganism adsorption ability and capable of adsorbing and retaining microorganisms and preventing them from falling off easily.

[0006]

[Means and operations for solving the problem] In order to achieve the above object, the invention as claimed in claim 1 is as follows.

[0007]

[Chemical formula 2] (wherein, R1 is a benzyl group, a C4 to C16 alkyl group, or a pentafluorophenylmethyl group, and X is a halogen atom) Water-insoluble or poorly water-soluble vinyl copolymer The gist of the project is ``a microbial adsorption membrane characterized by a microorganism adsorbed on the surface of a porous membrane.''

[0008] The invention according to claim 2 also provides a microorganism adsorption membrane according to claim 1, characterized in that the porous membrane is composed of a hydrophilic resin such as cellulose acetate or nitrocellulose. ” was its gist.

The porous membrane used in the present invention is not particularly limited, and may be a porous membrane conventionally used as a membrane filter, that is, an average pore diameter of 0.1 to 10.
.mu.m, and a film having a thickness in the range of 110 to 160 .mu.m is preferably used. In addition, when collecting particularly minute viruses is required, the average pore size should be 0.005 to 0.
．． A 2 μm ultrafiltration membrane may be used.

[0010] The porous membrane may be made of hydrophilic resin such as cellulose, nitrocellulose, or cellulose acetate, or may be made of polyolefin, polyamide,
Even if the film is made of a hydrophobic resin such as polyacrylonitrile, the following examples are made hydrophilic by surface treatments such as sulfonation treatment, fluorine treatment, ultraviolet rays or radiation irradiation, corona discharge treatment, plasma treatment, or coating with hydrophilic resin. It is preferable in this respect. In other words, the vinyl copolymer described below, or the 4-vinylpyridine and crosslinkable divinyl monomer constituting the vinyl copolymer, are dissolved in an organic solvent such as alcohol and applied to the surface of the porous membrane. granted to. Therefore, by using a porous membrane made of a hydrophilic resin, the porous membrane has good affinity with the solution containing the vinyl copolymer or the 4-vinylpyridine or monovinyl monomer that constitutes the vinyl copolymer. Become,
The solution will spread to every corner of the porous membrane. Moreover, the affinity with the vinyl pyridine units constituting the vinyl copolymer is improved, and the adhesive strength of the vinyl copolymer is improved. Furthermore, by using a porous membrane made of a hydrophilic resin, the vinyl copolymer applied to the porous membrane moves to the surface part of the porous membrane as it dries.
In other words, the so-called migration phenomenon of the vinyl copolymer, in which the vinyl copolymer moves in the direction of drying, is also prevented. Note that the pore diameter, porosity, shape, size, weight, etc. of the porous membrane can be freely selected depending on the purpose and usage conditions. A vinyl copolymer is attached to the surface of this porous membrane.

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

0012

embedded image In the formula, R1 is a benzyl group, a C4 to C16 alkyl group, or a pentafluorophenylmethyl group, R2 is a hydrogen atom or a C1 to C3 alkyl group, X is a halogen atom, Y is a hydrogen atom, and C1 to It is a C3 alkyl group, benzyl group, ether group, carboxyl group, carboxylic acid ester group, or aryl group. Further, this vinyl copolymer is a random copolymer or a block copolymer.

This vinyl copolymer is a cross-linked polyvinylpyridinium halide (Japanese Patent Publication No. 62
Although it has the same excellent ability to adsorb microorganisms (described in Publication No. 41641), it is insoluble or poorly soluble in water, but soluble in organic solvents, and it is difficult to make it into a solution. This makes it possible to perform processes such as impregnation and coating on other substrates (porous membranes), which were not possible with conventional cross-linked polyvinylpyridinium halide.

Monovinyl monomers used in the copolymerization include monoolefins such as ethylene, propylene, butene, styrene, vinyl acetate, acrylic acid, acrylic esters, methacrylic acid, methacrylic esters, aliphatic vinyl esters, acrylonitrile, and these. There are derivatives such as, but the present invention is not limited to these, and various derivatives can be used alone or in combination. However, if a monovinyl monomer having a highly hydrophilic functional group is used, the resulting copolymer may become water-soluble depending on the degree of polymerization, which is not desirable.

The ratio of 4-vinylpyridine to monovinyl monomer, that is, the ratio n:m, varies depending on the type of monovinyl monomer used and the degree of polymerization, but is approximately 10:90 to 90:10. Preferably within range. If the proportion of 4-vinylpyridine is less than this range, sufficient microbial adsorption ability will not be obtained, and if it is greater than this, the resulting copolymer will be highly water-soluble. Further, the degree of polymerization of the vinyl copolymer is at least 30
It is desirable that the degree of polymerization is 0 or more, and if the degree of polymerization is lower than this, the resulting copolymer will have high water solubility.

A copolymer of a monovinyl monomer and 4-vinylpyridine is produced by quaternizing pyridine by reacting it with a halide such as an alkyl halide, a benzyl halide, or a pentafluorophenylmethyl halide. form the pyridinium group represented.

[0017]

[Image Omitted] It is thought that this pyridinium group plays a major role in adsorbing microorganisms while keeping them in an active state. The mechanism for this is not clear, but since this pyridinium group is positively charged and the cell surface of microorganisms is generally negatively charged, it is assumed that electrostatic interaction is an important factor. Ru.

The vinyl copolymer thus obtained is substantially insoluble or sparingly soluble in water, but soluble in organic solvents. Taking advantage of this property, the vinyl copolymer is dissolved in an organic solvent to form a solvent solution. As this organic solvent, alcohols, esters, phenols, ethers, aromatic hydrocarbons, etc. can be used, but from the viewpoint of ease of handling, it is preferable to use alcohols.

A solution in which the vinyl copolymer is dissolved is applied to the porous membrane by means such as impregnation or coating. Thereafter, the vinyl copolymer is adhered to the surface of the porous membrane through a drying process.

The amount of vinyl copolymer adhering to the porous membrane is not particularly limited, but if the amount of vinyl copolymer adhering to the microorganism adsorption membrane is in the range of 0.01 to 20 wt%, microorganism adsorption is possible. It is powerful and economical. 2
If a large amount of vinyl copolymer exceeding 0 wt % is deposited, the adsorption effect will not increase even though the amount of vinyl copolymer used increases, resulting in uneconomical results.

[0021] In addition to the vinyl copolymer described above, the vinyl copolymer of the present invention may also be prepared by copolymerizing 4-vinylpyridine and a crosslinkable divinyl monomer as shown below on a porous membrane. , those quaternized with halides can also be used.

The crosslinkable divinyl monomer used in this vinyl copolymer includes 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, the crosslinkable divinyl monomer and 4-vinylpyridine are added to an organic solvent such as alcohols, esters, phenols, ethers, aromatic hydrocarbons, etc. to form a solution. By immersing the porous membrane in this solution or by coating the surface of the porous membrane, a predetermined amount of crosslinkable divinyl monomer and 4-vinylpyridine are applied to the surface of the porous membrane in the form of monomers. do. Next, all or 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 ability to adsorb microorganisms will decrease. The amount of vinyl copolymer attached to the porous membrane is not particularly limited, but the amount of vinyl copolymer attached to the microorganism-adsorbing membrane in the range of 0.01 to 20 wt% has high microbial adsorption power. , and economical. Also,
A conventional radical initiator such as benzoyl peroxide or azobisisobutyronitrile is added to the solution containing each monomer. Furthermore, 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 attached to the surface of the porous membrane in the form of monomers are copolymerized under heating. The polymerization temperature is 50 to 100° C. under normal pressure or increased pressure.

The obtained copolymer is produced by quaternizing pyridine by reacting it with a halide such as an alkyl halide, a benzyl halide, or a pentafluorophenylmethyl halide, and producing a vinyl copolymer having a pyridinium group. is obtained. The amount of the halide to be used is appropriately determined depending on the content of 4-vinylpyridine units in the copolymer.

The vinyl copolymer thus obtained is substantially insoluble or sparingly soluble in water and organic solvents, and is different from the vinyl copolymer described in Japanese Patent Publication No. 62-41641. shows similar properties. In addition, this vinyl copolymer is attached to the surface of the porous membrane in the form of a monomer and copolymerized on this porous membrane.
The surface area per unit weight of the vinyl copolymer is increased, and its microbial adsorption efficiency is dramatically improved.

Two preferred examples of the vinyl copolymer used in the microbial adsorption membrane of the present invention have been listed above.
The vinyl copolymer has a halogenated pyridinium group in its molecule, which exhibits excellent microbial adsorption ability, and has a water-based copolymer that prevents the vinyl copolymer from eluting into the liquid to be used for collecting microorganisms or sterilizing by filtration. If it is a vinyl copolymer that meets the requirements of being insoluble or poorly soluble in water, and being easily processed such as impregnation into porous membranes and coating, it is limited to this. isn't it.

[0028] The microorganisms to be adsorbed by the microorganism adsorption membrane of the present invention include bacteria, fungi, algae, viruses, and the like.

[0029] Through experiments conducted by the present inventors, it has become clear that the vinyl copolymer of the present invention requires moisture in order to fully exhibit its characteristic microbial adsorption ability. . Therefore, when the microbial adsorption membrane of the present invention is used in an air layer, it is necessary to use alkaline earth metal salts such as calcium chloride, magnesium chloride, lithium chloride, potassium metasilicate, titanium sulfate, etc. together with the vinyl copolymer. Apply deliquescent substances, water-soluble polymers such as polyvinyl alcohol, polyacrylate, and vinyl pyrrolidone, and humectants such as silica gel, zeolite, collagen, diphosphorous pentoxide, magnesium oxide, and ethylene glycol to the surface of the porous membrane. It is attached to the surface. As a result, the microorganism adsorption membrane exhibits excellent microorganism adsorption ability as in the case of an aqueous system.

In addition, when the microorganism adsorption membrane of the present invention is used only for the purpose of removing microorganisms, if a bactericide is attached to the surface of the porous membrane together with the vinyl copolymer of the present invention, It is possible to obtain a microbial adsorption membrane that has not only microbial adsorption ability but also sterilization performance. Examples of such disinfectants include antibiotic polymyxins, positive surfactants such as quaternary ammonium salts, amphoteric surfactants such as alkylaminoethylglycine, piguanides such as chlorhexidine and polyhexamethylene piguanidine, and undecylenic acid. Higher fatty acids, metals and metal ions, phenols, etc. can be used. In particular, when it is desired that the disinfectant be water-insoluble, use antibacterial zeolite in which zeolite is substituted with metal ions having bactericidal properties, or piganide or quaternary ammonium salts in polymer chains such as polyvinyl, polyacrylate, polyester, and polyamide. Polymer-type immobilized bactericides, silicone-type immobilized bactericides such as 3-(trimethoxysilyl)-propyltrimethyloctadecyl ammonium chloride, etc. can be suitably used.

[0031]

EXAMPLES The present invention will be explained in detail below according to examples. Example 1 After copolymerizing 4-vinylpyridine and styrene in a 30:70 mole ratio, a vinyl copolymer having a pyridinium group was obtained by quaternizing with benzyl bromide in an equimolar amount to 4-vinylpyridine. Obtained.

[0032] An ethanol solution in which this vinyl copolymer was dissolved was added to a film having pores with an average pore diameter of 0.45 μm and a film thickness of 1.
After impregnating a porous membrane made of nitrocellulose with a thickness of 45 μm, it was dried at 75° C. to obtain a microorganism-adsorbing membrane with a vinyl copolymer adhesion rate to the porous membrane of 0.2% by weight. After setting this microbial adsorption membrane in an ultrafiltration device with an inner diameter of 42 mm, T-4 bacterial phage was added to this device in 0.85% sterile physiological saline at 2.79 x 107 PF.
25 ml of the suspension at a concentration of U/ml was added, connected to a nitrogen cylinder, and filtered while applying a pressure of 0.5 kg/cm2. The amount of T-4 bacterial phage in the filtrate was measured by the PFU (Planck formation unit) method,
The removal rate was determined and shown in Table 1. A similar experiment was conducted using a stack of three microbial adsorption membranes, and the removal rates are 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 pores with an average pore diameter of 0.45 μm and a film thickness of 145 μm was used. T- in the way
4 bacterial phages were removed, and the removal rates are shown in Table 1.

[0034]

[Table 1]

Example 2 3 g of 4-vinylpyridine, 0.05 g of divinylbenzene
, 0.03 g of azobisisobutyronitrile and 300 ml of toluene were placed in a reaction container, and in this container, 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 placed. I put it in and soaked it. Thereafter, toluene is evaporated at room temperature to deposit 4-vinylpyridine, divinylbenzene, and azobisisobutyronitrile on the surface of the porous membrane. After this, 80℃
Leave it in a thermostat for 5 hours at a temperature of
- Copolymerizing vinylpyridine and divinylbenzene.

Next, the porous membrane with the copolymer attached to its surface was placed in a reaction vessel, and benzyl bromide and toluene were added to the vessel and reacted at 80°C for 6 hours to undergo quaternization treatment to form pyridinium groups. A microorganism-adsorbing membrane was obtained in which a vinyl copolymer having 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 with an inner diameter of 42 mm, 0.85% T-4 bacterial phage was added to this device.
25 ml of a suspension in sterilized saline at a concentration of 2.79 x 107 PFU/ml was added, connected to a nitrogen cylinder, and filtered while applying a pressure of 0.5 kg/cm2. The amount of T-4 bacterial phage in the filtrate is determined by PF.
It was measured by the U (Planck Formation Unit) method, and the removal rate was determined and shown in Table 2.

Comparative Example 2 No vinyl copolymer attached, average pore diameter 0.2 μm
T-4 bacterial phage was removed in the same manner as in Example 2 using only a porous membrane made of cellulose acetate with pores of 125 μm in thickness, and the removal rate was determined and shown in Table 2. Ta.

[0038]

[Table 2]

[0039]

[Effect of the invention] By having the above configuration, claim 1
The microbial adsorption membrane of the invention described above has a vinyl copolymer with excellent microbial adsorption ability attached to the surface of the porous membrane, so that its ability to adsorb microorganisms is dramatically improved. It is possible to efficiently collect even the most microorganisms.

Further, in the microorganism adsorption membrane of the invention as claimed in claim 1, microorganisms are adsorbed and retained on the microorganism adsorption membrane by the vinyl copolymer attached to the surface of the porous membrane, and are easily absorbed. Never falls off.

Furthermore, in the microorganism adsorption membrane according to claim 2, by using a porous membrane made of a hydrophilic resin,
Vinyl copolymer or 4 constituting the vinyl copolymer
- The solution containing vinylpyridine or monovinyl monomer has good affinity with the porous membrane, and the solution can be spread throughout the porous membrane. Furthermore, the affinity with the vinyl pyridine units constituting the vinyl copolymer is improved, and the adhesive strength of the vinyl copolymer can be improved. Furthermore, by using a porous membrane made of a hydrophilic resin, migration of the vinyl copolymer can be prevented.

Claims (2)

[Claims] Claim 1: A water-insoluble or poorly water-soluble compound having a functional group represented by the following formula: (wherein R1 is a benzyl group, a C4 to C16 alkyl group, or a pentafluorophenylmethyl group, and X is a halogen atom) A microorganism-adsorbing membrane characterized by a vinyl copolymer attached to the surface of a porous membrane. 2. The microorganism-adsorbing membrane according to claim 1, wherein the porous membrane is made of a hydrophilic resin such as cellulose acetate or nitrocellulose.