JP2007224064A - Method for producing antimicrobial resin molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a transparent antibacterial resin molded product suitable for a liquid feeding hose, etc., for a food beverage and having minimum eluted materials and excellent antibacterial properties. <P>SOLUTION: The method for producing the antibacterial resin molded product is characterized by exposing the surface of a resin molded product in which a resin composed of a repeating unit of ethylene vinyl alcohol is contained in the surface to radiation. The surface of the resin composed of the repeating unit of the ethylene vinyl alcohol in such a state as to contact water containing a ≤3C alcohol is exposed to the radiation during the exposure thereto. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a resin molded article having excellent antibacterial properties. Specifically, the present invention relates to a method for producing an antibacterial resin molded article that can be applied as an antibacterial material with very little eluate in both transparent and opaque resins, and is particularly suitable for use as a tube. .

  Conventionally, products that can prevent the occurrence of mold and bacteria in parts that require a sanitary environment such as indoor water circulation and hot and humid places have been demanded.

  In addition, there are technologies that specifically control the growth of harmful microorganisms by incorporating antibacterial substances into various polymer materials such as food packaging, construction, clothing, sanitary goods, kitchenware, and water treatment equipment. Pre-existing.

  In particular, in the case of food packaging materials and water treatment devices, it has been common to use silver ion-substituted zeolite, which is an inorganic compound, as the main antibacterial substance from the viewpoint of safety to humans. Among metal ions, silver ions have the strongest antibacterial properties, and silver nitrate solutions have a history of being used as disinfectants for medical and military purposes. However, silver-containing antibacterial agents have excellent antibacterial activity among inorganic compounds, but have problems such as discoloration due to high temperature or light irradiation, and loss of transparency, and the antibacterial performance decreases with time. There are also challenges. As antibacterial substances, not only inorganic compounds but also natural products are attracting attention from the viewpoint of safety, but there is a problem that natural products have low antibacterial performance.

  Organic compounds generally have better antibacterial performance than natural products and inorganic compounds, but are easily dissolved in water, organic solvents, and the like, and are easy to volatilize and separate. In addition, organic compounds tend to be avoided because of their toxicity. Therefore, organic compounds are not suitable for applications that require antibacterial performance for a long period of time, such as clothes, daily necessities, furniture, or building materials.

  Under such circumstances, recently, an insoluble, non-toxic immobilized antibacterial material in which an organic antibacterial agent is ionically or covalently bonded to a polymer material has been developed.

Specifically, an antibacterial material mainly composed of a polymer substance including an antibacterial component having a quaternary ammonium base ion-bonded with an acidic group such as a carboxyl group or a sulfonic acid group has been proposed (see Patent Document 1). . In addition, as inventions in which phosphonium salts are fixed to a polymer substance and attempted to expand the application, a proposal for an antibacterial agent of a phosphonium salt vinyl polymer (see Patent Document 2) and a vinylbenzylphosphonium salt vinyl polymer In addition, a proposal for an antibacterial agent (see Patent Document 3) and a proposal for an antibacterial resin composition containing a high molecular weight antibacterial agent and a hydrophilic vinyl polymer (see Patent Document 4) have been made. Yes.
JP 54-86584 A JP-A-4-814365 JP-A-5-310820 JP 2001-055518 A

  However, in the kneading of the silver-substituted zeolite into the plastic sheet, the silver ions used are only a small amount of the silver-substituted zeolite exposed on the surface, which means that the utilization efficiency of expensive silver is very high. It is low. In addition, when the antibacterial sheet is used in the presence of a nutrient source, the antibacterial property is determined by the competitive relationship between the ability of silver ions to inhibit the growth of microorganisms and the growth rate of microorganisms. It is necessary to increase. However, in the conventional kneading method of silver-substituted zeolite, the maximum content of zeolite is 5% in terms of weight ratio due to continuous productivity and a decrease in barrier properties due to pinholes, and the silver ion concentration on the surface is very high. There was a problem that it could only be changed within a limited range. In addition, it becomes cloudy by kneading silver ions even with transparent resins, and problems such as changes in contents cannot be visually observed in food packaging applications and water treatment equipment applications, and there are limits to the useful life There is also.

  In addition, for antibacterial resin compositions containing a high molecular weight antibacterial agent and a phosphonium salt vinyl polymer, for example, for food applications, the phosphonium salt vinyl polymer is eluted in foods, and has an antibacterial effect. Problems such as not lasting. In addition, when a resin molded product containing a phosphonium salt vinyl polymer is exposed to a temperature of 150 ° C. or higher during melt molding, the phosphonium salt vinyl polymer that is a hydrophilic polymer is easily decomposed, and coloring, strength reduction, etc. There is a problem.

  Accordingly, an object of the present invention is to solve the above-mentioned problems, have antibacterial properties better than silver ions, can maintain transparency even when used in transparent materials, and can be used for food applications. An object of the present invention is to provide a method for producing a conductive resin molding.

  The method for producing an antibacterial resin molded body of the present invention comprises irradiating a resin molded body containing a resin comprising a repeating unit of ethylene vinyl alcohol represented by the following chemical structural formula (1) on its surface with an antibacterial It is a manufacturing method of a conductive resin molding.

(Wherein the ratio of m to n is 0.1: 99.9 to 99.9: 0.1)
According to the preferable aspect of the manufacturing method of the antibacterial resin molding of this invention, the said radiation is an electron beam and / or a gamma ray.

  According to a preferred embodiment of the method for producing an antibacterial resin molded body of the present invention, the antibacterial resin molded body obtained by the method for producing an antibacterial resin molded body of the present invention can be used as a water purifier or a water purifier for a food and beverage. Can be installed in a beer server.

  According to the present invention, it is possible to obtain a transparent antibacterial resin molded article having excellent antibacterial properties by using a transparent resin material from the beginning, and it is eluted in water even if it contains a repeating unit having a hydrophilic group. An antibacterial resin molded product having an extremely small amount can be obtained. The antibacterial resin molding of the present invention has better antibacterial properties than silver ions, and can be suitably used for food and beverage applications and water purifier applications.

  The method for producing an antibacterial resin molded body of the present invention comprises irradiating a resin molded body containing a resin comprising a repeating unit of ethylene vinyl alcohol represented by the following chemical structural formula (1) on its surface with an antibacterial It is a manufacturing method of a conductive resin molding.

  In the present invention, a resin (EVOH resin) composed of repeating units of ethylene and vinyl alcohol is used as a resin that must be contained in at least a part of the molded body. The preferred number average molecular weight of this resin is 100 to 10000000. The ethylene content is preferably from 0.01 to 99.99 mol%, most preferably from 15 to 80 mol%.

  Conventionally, resins consisting of repeating units of ethylene and vinyl alcohol have been used for packaging materials for various applications because of their excellent gas barrier properties, and used for film applications such as ham and sausage, and bottle applications such as mayonnaise and ketchup. It has been. The resin composed of repeating units of ethylene and vinyl alcohol has a characteristic that since the vinyl alcohol has a hydrophilic group, it absorbs moisture when the humidity is high and the gas barrier property is greatly reduced. Therefore, even in the above-mentioned film use and bottle use, a resin composed of repeating units of ethylene and vinyl alcohol maintains high gas barrier properties, so that nylon, low density polyethylene, high density polyethylene, polyethylene terephthalate, polypropylene, polycarbonate, vinyl acetate- It is used by being laminated and covered with a resin such as an ethylene copolymer so as not to absorb moisture from the surface.

  In the present invention, antibacterial properties can be exhibited by coating the surface of the molded body with a resin composed of repeating units of ethylene and vinyl alcohol having a hydrophilic group and irradiating the resin with at least part of the surface.

  Examples of commercial products of ethylene vinyl alcohol resin include “EVAL” (registered trademark) L101, F101, H101, E101, G101 (manufactured by Kuraray Eval Company), and “Soarnol” (registered trademark) V2603, D2908, AT4403. , A4412, and H4815 (manufactured by Nippon Synthetic Chemical Co., Ltd.).

  Further, it may be copolymerized with another monomer other than the ethylene vinyl alcohol resin of the present invention, or may be a blend with other resin, as long as the effect of the present invention is not hindered. The amount of other copolymerization monomer or blend resin added is not particularly limited, but is preferably 90% by weight or less, more preferably 60% by weight or less, and 40% by weight or less. More preferably, it is most preferably 20% by weight or less.

  When blending resins, the compatibility of the ethylene vinyl alcohol resin and other resins affects the transparency of the molded product. For example, when the compatibility is good, the thin-walled molded product can maintain transparency, and when the compatibility is poor, it becomes an opaque molded product and a resin to be blended must be selected depending on the application.

  As the resin blended with the ethylene vinyl alcohol resin of the present invention, a general-purpose thermoplastic resin resin, thermosetting resin, rubber or the like can be used, and is not particularly limited.

  Although not limited to the following for such resins, specific examples include polyolefin, polystyrene, polyvinyl, polyacryl, polyhaloolefin, polydiene, polyether, polyester, polyamide, polyurethane, polyurea, polyimide, polyanhydride, polycarbonate, Polyimine, polysiloxane, polyphosphazene, polyketone, polysulfone, polyethersulfone, polyphenylene, phenol resin, urea resin, melamine resin, diallyl phthalate resin, silicon resin, vinyl chloride, vinylidene chloride, vinyl acetate, polyvinyl alcohol, polyvinyl acetal, polystyrene , AS resin (copolymer of styrene and acrylonitrile), ABS resin, ACS resin (chlorinated polyethylene with acrylonitrile and styrene graph Polymerized), methacrylic resin, polyethylene, EVA resin (ethylene and vinyl acetate copolymer), polypropylene resin, polybutene resin, polybutylene resin, methylpentene resin, polybutadiene resin, fluororesin, (polytetrafluoroethylene, polychlorotriethylene) Fluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-ethylene copolymer), polyamide, polyacetal, saturated Polyester, polyphenylene ether, polyphenylene sulfide, polyarylate, polyether ether ketone, liquid crystal plastic, cellulosic polymer, heatable Sex elastomers, artificial rubber, natural rubber, and the like.

  Examples of the resin preferably used in the present invention include radiation such as polyethylene, polypropylene, polystyrene, polymethylpentene, polysulfone, polyethersulfone, polyacrylate, polyacrylamide, polyvinyl chloride, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, and polyvinylpyrrolidone. There are cross-linked resins, copolymer resins, and thermoplastic resins.

  In the case of a radiation-disintegrating resin such as polyisobutylene or polyvinylidene chloride even with a similar vinyl type monomer, it is preferable to carry out the reaction with an extremely reduced radiation dose. Since these distinctions are affected by conditions such as temperature and atmosphere at the time of radiation irradiation, depending on the conditions, not only polyolefin resin but also nylon or polydimethylsiloxane can be used.

  Moreover, it is also possible to use a photosensitizer for resin which comprises the antibacterial resin molding of this invention. When a photosensitizer is used, photons are absorbed and excited, hydrogen is extracted from the resin, and radical active sites can be formed in the resin. Examples of such photosensitizers include benzophenone, 3,3 ′, 4,4′-benzophenone tetracarboxylic anhydride, 4,4′-dimethoxybenzophenone, 4-chlorobenzophenone, 2 , 4-dichlorobenzophenone, 4,4′-dichlorobenzophenone, 4-fluorobenzophenone, 4-trifluoromethylbenzophenone, 4-methoxybenzophenone, 4-methylbenzophenone, 4, Benzophenone photosensitizers such as 4′-dimethylbenzophenone, 4-cyanobenzophenone and o-benzoylbenzophenone, benzyl photosensitizers such as benzyl and dibenzylketone, 2-methylthioxanthone, 2 -Thioxanthone photosensitizers such as ethylthioxanthone, thioxanthone, 2-isopropylthioxanthone, anthraquinone, 2-ethylanthone Anthraquinone photosensitizers such as laquinone, 2-chloroanthraquinone and 2-t-butylanthraquinone, benzaldehyde photosensitizers such as benzaldehyde, 4-methoxybenzaldehyde, 4-methylbenzaldehyde and 1-naphthaldehyde, 2,3 -Dione photosensitizers such as butanedione, 2,3-pentanedione, dibenzosuberone, methyl-o-benzoylbenzoate, 9-fluorenone, 3,4-benzofluorene, 1-acetylnaphthalene, benzanthrone, 9, Examples thereof include 10-phenanthrenequinone, 2-benzoylnaphthalene, 3,5-dimethylacetophenone, and 4-bromoacetophenone.

  In the resin used in the present invention, additives and the like may be mixed as long as the effects of the present invention are not hindered. The addition amount of the additive is not particularly limited, but is preferably 10% by weight or less.

  The antibacterial resin molded body of the present invention can be irradiated with radiation in any shape such as plate, rod, sheet, tube, film, fiber, bead, powder, and hollow fiber. If you can, you can basically do it. For the antibacterial resin molding of the present invention, a known molding method such as stretch molding, injection molding, extrusion molding or the like can be used.

  In the present invention, formation of a graft layer by irradiation with radiation such as α-rays, β-rays, γ-rays, electron beams and X-rays, or ultraviolet rays is preferable, and among them irradiation with any of γ-rays, electron beams and ultraviolet rays is preferable. Most preferably, γ rays and electron beams are used.

  As described above, the radiation is particularly preferably an electron beam and a γ-ray, and as an electron beam characteristic, the acceleration voltage is preferably at least 10 Kv or more from the viewpoint of transmission power and activation efficiency. For example, an electro curtain system, a scanning type, a double scanning type, a bandegraph, a cold cathode, or the like is used. In the case of γ rays, the irradiation dose is preferably 10 kGy or more, more preferably 20 kGy or more, and most preferably 25 kGy or more. The reason is that the effect of reducing the eluate and the antibacterial properties are not sufficient.

  During irradiation, replacement with an inert gas such as nitrogen or helium is performed because high concentrations of oxygen can cause the deactivation of graft active species (mainly free radicals) or can lead to resin degradation due to oxidation reactions. It is preferable to reduce the oxygen concentration. However, this is not the case when a peroxide is used as the graft active species. The grafting reaction can be achieved by reacting with a monomer directly or using a solvent after irradiation or reacting with a vaporized monomer. In general, a monomer alone often has a slow reaction rate, and thus a reaction in a solution system using a solvent is advantageous. In order to prevent homopolymerization of the monomer alone, a radical polymerization inhibitor such as a mole salt, a redox additive such as metallic copper and cuprous chloride, and a polymerization inhibitor such as hydroquinone monomethyl ether are used in combination. Also good.

  The grafting reaction by irradiation with radiation has an advantage that the reaction is fast because it has a high dose rate, it can be performed at a low temperature, and the amount of grafting is large. In addition, there is an advantage that the antibacterial resin molded body can be pre-sterilized by irradiation. In addition, when starting the reaction, grafting is possible without using a polymerization initiator that leaves harmful and offensive odor decomposition products in the graft layer even after the completion of the reaction. .

  When performing radiation irradiation, polypropylene, polytetrafluoroethylene, and the like are likely to deteriorate with age and cause deterioration in physical properties when extremely intense radiation is irradiated. In addition, although polyvinyl chloride is a cross-linked resin, it undergoes a dehydrochlorination reaction by radiation and is colored. The degree of coloring varies depending on the radiation dose, and the color turns amber at a low dose and turns brown at a high dose, but the degree and color of the coloring also change depending on the additive. Therefore, when irradiating these resin moldings with radiation, the radiation dose is adjusted with attention to changes in physical properties.

  In the present invention, the radiation irradiation treatment used is effective in developing antibacterial properties on the surface of the resin molding. At this time, the absorbed dose can be measured by attaching a dose measurement label to the surface of the molded body.

  The treatment method for radiation irradiation of the present invention is not particularly limited. Also, the atmosphere during radiation irradiation is not particularly limited, and among them, the whole or at least part of the resin molding is selected from air, inert gas, active gas, water, organic solvent, monomer solution, polymer solution. It is preferable to irradiate with radiation while being in contact with at least one medium. Among them, in consideration of cost, safety and handling, a state where air or water is in contact with the whole or at least a part of the resin molded body It is more preferable to irradiate with radiation, and it is most preferable to irradiate the resin molded body with water in a state where it is in contact with water (wet state).

  In the present invention, as long as the resin molded body is in a water-containing state, radiation can be preferably irradiated even in a state where there is no medium on the surface of the resin molded body. The water content at that time is preferably 0.01% by weight or more, more preferably 1% by weight or more, and most preferably 3% by weight or more. As an example of the water-containing method for the resin molded body, there is a method in which the entire or part of the resin molded body is taken out after being immersed in water and then irradiated with radiation in a water-containing state.

  The absorbed dose of radiation to the resin molding is preferably about 10 to 50 kGy in a wet state. When a dose exceeding 20 kGy is irradiated, sterilization can be performed simultaneously. At this time, the absorbed dose can be measured by attaching a dose measurement label to the surface of the molded body.

  Here, when radiation irradiation in the case where the resin molding is a tube is exemplified, strong antibacterial properties are imparted to the wet portion by immersing the tube in water and irradiating the radiation in a wet state. The Thereafter, the tube-shaped resin molded body obtained may be washed as necessary. In addition, when antibacterial properties are imparted to only a part of a resin molded body, for example, the inside of a tube that is a resin molded body, the inside of the tube is filled with water, and both ends of the tube are sealed (caps). May be irradiated. Thereafter, the inside of the tube may be washed by passing tap water or the like.

  In the present invention, the strength of antibacterial properties can be more preferably controlled by adding alcohol to water. Specific examples of alcohols include methanol, ethanol, propanol, isopropyl alcohol, benzyl alcohol, ethylene glycol monophenyl ether, 2-methoxyethanol, carbitol monoethyl ether, diethylene glycol monohexyl ether, diethylene glycol mono-2-ethylhexyl ether, triethylene. Glycol monoethyl ether, dipropylene glycol monomethyl ether, polyethylene glycol monomethyl ether, diethylene glycol, triethylene glycol, dipropylene glycol, polypropylene glycol, 1,3-butanediol, 1,4-butanediol, and the like. The following alcohols: methanol, ethanol, propanol Isopropyl alcohol may be used most suitably.

  In addition, the amount of alcohol to be added must be controlled appropriately depending on the antibacterial properties and applications. The alcohol addition amount is not particularly limited, but can be used in the range of 1 ppt to 50% by weight in the aqueous antimicrobial polymer solution, preferably 1 ppm to 5% by weight, more preferably 1 ppm to 1% by weight, and more. Preferably it is used in the range of 10 ppm to 0.8% by weight, most preferably in the range of 50 ppm to 5000 ppm.

  In the present invention, the tube-shaped antibacterial resin molded body can be used alone, but it can also be used as a multilayer tube formed by laminating a plurality of tube-shaped resin molded bodies. In the case of using a plurality of layers depending on usage, internal pressure, external pressure, and the like, any number of tubes is possible, but practically, a single-layer to 20-layer tube is preferable.

  Since the antibacterial resin molded article of the present invention has antibacterial properties, when it is used as a multilayer tube, a resin composed of repeating units of ethylene vinyl alcohol is contained in all or part of the innermost layer and / or outermost layer. In this case, the antibacterial effect is exerted on the tube surface, and it is preferably used, and the innermost layer most preferably contains a resin composed of repeating units of ethylene vinyl alcohol.

  When the present invention is used for a multilayer tube, other layers other than the ethylene vinyl alcohol resin layer can use known different materials and are not particularly limited, but polyolefin, polystyrene, polyvinyl, polyacryl, polyhaloolefin, polydiene, Polyether, polyester, polyamide, polyurethane, polyurea, polyimide, polyanhydride, polycarbonate, polyimine, polysiloxane, polyphosphazene, polyketone, polysulfone, polyethersulfone, polyphenylene, phenol resin, urea resin, melamine resin, diallyl phthalate Resin, silicon resin, vinyl chloride, vinylidene chloride, vinyl acetate, polyvinyl alcohol, polyvinyl acetal, polystyrene, AS resin (a copolymer of styrene and acrylonitrile), A S resin, ACS resin (grafted acrylonitrile and styrene on chlorinated polyethylene), methacrylic resin, polyethylene, EVA resin (ethylene and vinyl acetate copolymer), polypropylene resin, polybutene resin, polybutylene resin, methylpentene resin, Polybutadiene resin, fluororesin (polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, Tetrafluoroethylene-ethylene copolymer), polyamide, polyacetal, saturated polyester, polyphenylene ether, polyphenylene sulfide, polyarylene , Porieterue - Teruketon, liquid crystal plastics, can be used cellulosic polymer, thermoplastic elastomer, silicone rubber, artificial rubber, resin selected from one or more of natural rubber.

  When the antibacterial resin molding of the present invention is a multilayer tube, if there is a problem in the interlayer adhesion of the outer layer and / or the tube adjacent to the inner layer made of ethylene vinyl alcohol resin, peeling may be observed when the multilayer tube is cut. If it is bent slightly, delamination may occur. It is effective to improve adhesion between layers as a means for suppressing delamination, and a method in which an adhesive layer made of an adhesive resin is interposed in at least a part between an outer layer tube and an adjacent inner layer tube, or an adjacent outer layer tube And / or by containing adhesive resin in at least one part of an inner layer tube, the adhesive force of an outer layer and an inner layer can be improved, and delamination can be suppressed. Further, delamination can be suppressed even when the molding method is multilayer simultaneous molding or multilayer sequential molding. When the adhesive resin is contained in at least a part of the outer layer tube and / or the inner layer tube, the adhesive resin can be used in the range of 0.01% to 100 wt%.

  Similarly, when an adhesive layer is provided between the outer layer and the inner layer, the adhesive layer can be used in the range of 0.01% to 100% by weight. There are no particular limitations on the number of layers that the adhesive resin contains in the multilayer tube. The multilayer tube obtained in this way is useful because it does not peel off during cutting and the bending radius can be reduced.

  Although it does not specifically limit with adhesive resin said by this invention, For example, polyolefin resin, maleic anhydride resin, polyester resin etc. can be used suitably as adhesive resin.

  The polyolefin-based adhesive resin is not particularly limited. For example, the ethylene-based polymer is modified with an ethylene-based polymer and / or an unsaturated carboxylic acid or a derivative thereof, and the content thereof is 0.01 to 10% by weight. (Component A), a pressure-sensitive adhesive (Component B), and a block copolymer having at least one polymer block mainly composed of a vinyl aromatic compound and at least one polymer block mainly composed of a conjugated diene compound. A polymer or a hydrogenated product thereof (component C), and component A is 35 to 98% by weight, component B is 0.5 to 62% by weight, and component per total amount of component A, component B and component C Resin in which C is 0.5 to 62% by weight. Other examples include a modified polyolefin resin in which an alkaline compound and an organic acid or an acid anhydride thereof are blended with an olefin resin containing a component modified with an unsaturated carboxylic acid or an acid anhydride thereof.

  For example, as specific products, “MODIC-AP” (registered trademark) HDPE grades H511, H503, LDPE grades L112A, L502, L553, L504, EVA grades A543, A515, PP grade P502 , P604V, P565, special grades such as F502, F532, and F534A (manufactured by Mitsubishi Chemical Corporation) can be used.

  The maleic anhydride-based adhesive resin is not particularly limited, but for example, ethylene-α, β-unsaturated carboxylic acid alkyl ester-maleic anhydride terpolymer has an ethylene unit of 40 to 90% by weight, α, Hydrogenation of a copolymer comprising 55 to 5% by weight of β-unsaturated carboxylic acid alkyl ester unit and 0.1 to 10% by weight of maleic anhydride unit, as well as hydrogenation of styrene / conjugated diene / styrene block copolymer Examples thereof include a resin comprising a modified block copolymer obtained by graft-polymerizing maleic anhydride to a product.

  For example, as specific products, polyolefin resins and the like listed in “Bondaine” (registered trademark) LX4110, HX8210, TX8030, HX8290, HX8140, AX8390 (manufactured by Arkema) and the like can be used.

  The polyester-based adhesive resin is not particularly limited. For example, the ethylene-based polymer is modified with an ethylene polymer and / or an unsaturated carboxylic acid or a derivative thereof, and the content thereof is 0.01 to 10% by weight. (Component D), a pressure-sensitive adhesive (Component E), and a block copolymer having at least one polymer block mainly composed of a vinyl aromatic compound and at least one polymer block mainly composed of a conjugated diene compound. Containing polymer or hydrogenated product thereof (component F), component D is 35 to 98% by weight, component E is 0.5 to 62% by weight and component per total amount of component D, component E and component F Examples thereof include resins having F of 0.2 to 80% by weight. For example, specific products include “Primalloy-AP” (registered trademark) A1500N, A1600N, A1700N, A180. N, A1900N, B1902N, B1900N, B1903N, B1910N, B1920, B1922N, B1932N, B1942N, A1606C, A1706C, A1602N, A1704N, A1610N, A1710N, B1600N, B1700N, B1800N, B1921N A resin or the like can be used.

  The antibacterial resin molded article of the present invention can also be obtained by irradiating a dry normal or wet raw material pellet with radiation and molding the irradiated pellet.

  That is, various shapes can be obtained by using stretch molding, injection molding, extrusion molding, cast film forming method, wet coagulation method and the like. For example, it can shape | mold into forms, such as a tube shape, a bead, a knitted fabric, a nonwoven fabric, a cut fiber, a flat membrane, a hollow fiber membrane, a film, and a sheet | seat.

  The content ratio of the resin having a repeating unit of ethylene vinyl alcohol in the antibacterial molded article of the present invention is preferably in the range of 0.1% by weight to 100% by weight, more preferably 50% by weight with respect to the weight of the molded article. % To 100% by weight, most preferably 80% to 100% by weight.

  Also in these other aspects of the present invention, the resin comprising the repeating unit of ethylene vinyl alcohol represented by the following chemical structural formula (1) described in the above-mentioned one aspect, the resin constituting the resin, and the use ratio thereof Radiation irradiation, a molding method, and the like can be applied as they are.

  The present invention exhibits an excellent antibacterial effect against various bacteria. For example, it has excellent antibacterial effects against Escherichia coli, Staphylococcus aureus, Vibrio parahaemolyticus, MRSA (methicillin-resistant Staphylococcus aureus), Neisseria pneumoniae (Legionella), lactic acid bacteria, acetic acid bacteria, etc. Excellent antibacterial properties. Therefore, the antibacterial material of the present invention can be used as a constituent material in places where the growth and growth of these bacteria and the like need to be sterilized.

The antibacterial test is conducted according to JIS Z2801, and the antibacterial activity is expressed by the magnitude of the antibacterial activity value. The antibacterial activity value is represented by the following mathematical formula (2),
Antibacterial activity value = log (B / C) (2)
B: Average value of the number of viable bacteria after 24 hours of the unprocessed test piece (PE film) C: The average value of each of the number of viable bacteria after 24 hours of the sample was inoculated into the sample film and the PE film. The number of bacteria after 24 hours is measured and then logarithmized. In JIS, an antibacterial activity value of 2 or more is defined as an antibacterial material. In the present invention, an antibacterial material is determined to have an antibacterial activity value of 0.5 or more from the viewpoint of inhibiting the growth of bacteria.

  The antibacterial activity value of the antibacterial resin molding of the present invention is preferably an antibacterial activity value of 0.5 or more, and an effect of inhibiting the growth of bacteria can be obtained, more preferably an antibacterial activity value of 1.0 or more, most preferably an antibacterial activity value of 2 Excellent antibacterial effect can be obtained at. The antibacterial activity value of the antibacterial resin molded product of the present invention can be controlled by the type of the antibacterial resin, the concentration of the antibacterial resin, the type and blending amount of the coating adjuvant, the radiation irradiation dose, etc. It can be used for convenience.

  The antibacterial resin molded body of the present invention can be made into a transparent antibacterial resin molded body by using a transparent resin or the like. For example, a tube-shaped transparent antibacterial resin molded body is easy to observe the inside, and can further suppress germs, and is therefore preferably used for a liquid feeding hose for foods and beverages. For example, in food manufacturing plants, etc., it is suitably used for soy sauce or sauce feeding hoses, etc. In beverage feeding hoses, beer servers are used in environments where the nutritional value of beverages such as beer and milk are high and bacteria are likely to grow. Since the beer server and the milker using this hose are free from germs, they are very hygienic and easy to maintain.

  The term “transparent” as used in the present invention means that the light transmittance of a film or sheet having a resin molded body thickness of 100 μm is 50% or more, preferably a light transmittance of 70% or more, and a transmittance of 85 % Or more is more preferable, and most preferably 88% or more.

  In addition, it can be used effectively for household water purifiers. In an under-sink type water purifier in which a water purifier cartridge is installed under the kitchen, a polyethylene tube, a stainless steel tube, or the like is conventionally used in the section between the card ridge under the kitchen and the faucet outlet on the kitchen. These tubes are filled with purified water dechlorinated by the cartridge. In such a state, if left untreated, bacterial growth was severe in clean water, and in severe cases, metabolites (white lumps) produced by bacterial growth were generated. With conventional polyethylene tubes and stainless steel tubes, the inside of the tube could not be observed, so it was not possible to notice any abnormalities until water was removed. By using the liquid feeding hose for beverages of the present invention, bacterial growth can be suppressed and the inside can be observed, which is very useful.

  About the amount of elution in water in the present invention, B. in the third apparatus and container packaging mentioned in the Food Sanitation Law (Ministry of Health, Labor and Welfare Notification) Notification No. 370. A leaching solution is prepared using a general test method for equipment or containers and packaging, and the amount of elution in water is measured by TOC analysis.

That is, the amount of elution in water can be measured by using a TOC (soluble organic matter) meter. The sample is thoroughly washed with ultrapure water, and a leaching solution designated at a rate of 2 ml per 1 cm ² of the surface area of the sample is used. And left at 60 ° C. for 30 minutes. After cooling, this solution is used as a test solution.

  By measuring the test solution obtained here according to JIS K 0102 22.1 (combustion oxidation-infrared TOC analysis method), the elution amount of the antibacterial resin molded product of the present invention in water is measured. be able to.

  The amount of the eluate in water is preferably 500 ppm or less, more preferably 150 ppm or less, further preferably 60 ppm or less, and most preferably the amount eluted in water is 30 ppm or less. More preferably, it is 10 ppm or less. In addition, since there is an effect on the human body in drinking water and food applications, the amount of the eluate in water is preferably 5 ppm or less, more preferably 1000 ppb or less, further preferably 500 ppb or less, and most preferably. The elution amount in water is 100 ppb or less.

  To reduce the amount of eluate in water, adopt a method that changes the insoluble matter by cross-linking with γ-rays, that is, a method that adjusts the degree of cross-linking, for example, a method that removes excess eluate that is not cross-linked by washing. can do.

Hereinafter, based on an Example, this invention is demonstrated concretely.

(Resin constituting the resin molding)
The resins that are the main components of the resin molding are listed below.

EVOH: ethylene vinyl alcohol copolymer (“SOANOL (registered trademark) D2908” manufactured by Nippon Synthetic Chemical Co., Ltd.)
EVOH2: ethylene vinyl alcohol copolymer (“SOANOL (registered trademark) A4412 manufactured by Nippon Synthetic Chemical Industry Co., Ltd.)”
Psf: Polysulfone (“Udel-P3500” (registered trademark) manufactured by Solvay)
PS: Polystyrene (“Styrene polymer” average polymerization degree 3500, manufactured by Wako Pure Chemical Industries, Ltd.)
PC: Polycarbonate (“Taflon (registered trademark) A2200” manufactured by Idemitsu Petrochemical Co., Ltd.)
EVA: ethylene-vinyl acetate copolymer (“Evaflex (registered trademark) EV460” manufactured by Mitsui DuPont Polychemical Co., Ltd.)
Polyolefin adhesive resin: ("Modic (registered trademark) -AP, grade A543" manufactured by Mitsubishi Chemical Corporation)
Maleic anhydride-based adhesive resin: ("Bondaine (registered trademark), grade TX8030" manufactured by Arkema)
(Antimicrobial test method)
The antibacterial test is conducted according to JIS Z2801.

The test bacteria described in (1) to (2) below were used.
・ Test bacteria (1) Escherichia coli NBRC 3972
(2) Staphylococcus aureus subsp. Aureus NBRC 12732
-Bacterial solution preparation: Common to each bacterium For details on pre-culture of the test bacteria (1) and (2), after culturing at 35 ° C on a normal agar medium for 16-24 hours, the obtained bacterial cells are 1/500 ordinary It was suspended in bouillon medium and prepared so that the number of bacteria per ml was about 10 ^6, and used as a bacterial solution.
Test operation of plate-like sample: common to each bacterium A plate-shaped antibacterial resin molded body cut to about 30 mm × 30 mm was lightly wiped with absorbent cotton soaked with 99.5% ethanol and allowed to air dry. After dropping 0.1 ml of the bacterial solution on the test surface of the sample, it was covered with about 20 mm × 20 mm polyethylene.

  This was stored at 35 ° C. ± 1 ° C. and a relative humidity of 90% or more, and the viable cell count of the sample was measured 24 hours after the storage.

In addition, a polyethylene film of about 30 mm × 30 mm was used as a comparative sample and tested in the same manner.
・ Test operation of tube-shaped sample: Common to each bacterium The surface cut into a semicircle in a direction perpendicular to the surface of the tube-shaped antibacterial resin molded body having an inner diameter of 5 mm × outer diameter of 7 mm and a length of 5 cm. The sample which cut | disconnected so that the innermost surface could be seen was obtained. The inner surface of the sample was lightly wiped with absorbent cotton soaked with 99.5% ethanol and allowed to air dry. After dropping 0.1 ml of the bacterial solution on the inner surface of the sample, it was covered with polyethylene of about 10 mm × 40 mm.

  This was stored at 35 ° C. ± 1 ° C. and a relative humidity of 90% or more, and the viable cell count of the sample was measured 24 hours after the storage.

Further, a polyethylene tube having an inner diameter of 5 mm, an outer diameter of 7 mm, and a length of 5 cm was used as a comparative sample and tested in the same manner.
・ Measurement of the number of viable bacteria: Common bacteria of each bacteria Survival bacteria were washed out with 10 ml of SCDLP medium (SOYBEAN-CASEIN DIGEST BROTH with LECITHIN & POLYSORBATE 80). The number of viable bacteria was measured by a plating plate culture method (35 ° C. ± 1 ° C., 2 days culture), and converted per sample.

  The antibacterial activity of the sample is determined using the antibacterial activity value defined in JIS Z2801, and the following formula (2) indicates that the antibacterial activity value of 2 or more is antibacterial, and the antibacterial activity value of less than 2 is antibacterial. Judged to be none.

Antibacterial activity value = log (B / C) (2)
B: Average value of the number of viable bacteria after 24 hours of the unprocessed test piece (PE film) C: Average value of the number of viable bacteria after 24 hours of the specimen (measurement of light transmittance)
The measurement was performed using an SM color computer SM-7-CH manufactured by Suga Test Instruments. The sample was a film molded body having a thickness of 30 μm, and the total light beam transmittance was measured in a room temperature-controlled at 25 ° C. The evaluation results are shown in Table 1.

(Measurement of elution amount in water)
1. Test method Prepare a leaching solution in accordance with “Standards for Food and Additives, Notification No. 370, Ministry of Health, Labor and Welfare No. 3 B. Equipment and Containers and Packaging”, and measure the amount of elution in water by TOC analysis. The measurement limit is 0.5 ppm or less.

2. Preparation of test solution in dissolution test Wash the sample thoroughly with ultrapure water in advance, and use the leaching solution specified at a rate of 2 ml per 1 cm ² of the surface area of the sample, and leave it for 30 minutes while maintaining at 60 ° C. After cooling, this solution is used as a test solution.

3. Analysis method Measurement method: JIS K 0102 22.1 (combustion oxidation-infrared TOC analysis method)
Device name: TOC-650 meter (manufactured by Toray Engineering)
Example 1
EVOH resin was molded by a hot press method (pressing at 230 ° C. → cooling to room temperature) to obtain a resin molded body having a thickness of 1 mm and a 3 cm square plate shape.

  The resin molded body obtained here was put into a PE (polyethylene) bag, filled with pure water, and irradiated with γ rays with a cobalt-60 radiation source to obtain a radiation-treated resin molded body. . The absorbed gamma ray dose was 25 kGy. The obtained radiation-treated resin molding was thoroughly washed with pure water, and the elution amount in water was measured by the antibacterial test method prescription and the underwater elution amount measurement prescription. As the measurement result, an average value of three measurement values was used. The results are shown in Table 1.

(Example 2)
The same treatment and evaluation as in Example 1 were performed except that the resin was changed to EVOH2. The results are shown in Table 1.

(Example 3)
The same treatment and evaluation as in Example 1 were performed except that ethanol was added at a concentration of 1000 ppm to pure water in a PE (polyethylene) bag containing the resin molding. The results are shown in Table 1.

Example 4
The same treatment and evaluation as in Example 3 were performed except that the resin was changed to EVOH2. The results are shown in Table 1. The results are shown in Table 1.

(Example 5)
Except for changing the resin molding to Soarnol (registered trademark) film A4403 (thickness 30 μm), the same treatment and evaluation as in Example 1 were performed, and the transmittance was further evaluated. The results are shown in Table 1.

(Example 6)
The multilayer tube of the present invention is produced using a known coextrusion molding machine. That is, using the first extrusion molding machine, the innermost layer resin, ethylene vinyl alcohol resin (EVOH2), and the outermost layer ethylene-vinyl acetate copolymer resin (EVA) are heated and melted and molded in the range of 180 to 230 ° C. At the same time, an inner tube made of an ethylene vinyl alcohol resin having an inner diameter of 5 mm and a wall thickness of 0.2 mm is extruded through a common head die at the same time, and at the same time, an ethylene-vinyl acetate copolymer resin (EVA) is used using a second extruder. The outer layer tube made of ethylene-vinyl acetate copolymer resin having a wall thickness of 2.3 mm is extruded through the common head die at a molding temperature in the range of 160 to 220 ° C. The two-layer laminated tube of the present invention having an inner diameter of 5 mm and an outer diameter of 10 mm was obtained by continuously heat-fusing and pressing the outer peripheral surface and bonding them together.

  This two-layer tube was cut to a length of 50 cm, sealed (cap) on one side of the tube, filled with pure water, and sealed so as not to enter air. The tube filled with pure water was irradiated with γ rays with a cobalt-60 radiation source to obtain a radiation-treated tube. The absorbed gamma ray dose was 25 kGy. The obtained radiation tube was washed with 20 L of pure water, and the antibacterial test (tube shape), measurement of the amount of elution in water, end face peeling when cutting with pruning scissors, and delamination when bent slightly were observed. In addition, the tube was cut and the adhesion between the inner layer and the outer layer was also observed. The results are shown in Table 2.

(Example 7)
A radiation-treated tube by the same production method as in Example 6 except that the outermost layer resin molded by the second extruder is a blend ratio of ethylene-vinyl acetate copolymer resin (EVA): polyolefin adhesive resin = 10: 90 Got. Evaluation was performed in the same manner as in Example 6 using the obtained radiation-treated tube. The results are shown in Table 2.

(Comparative Example 1)
A Psf resin was molded by a hot press method to obtain a resin molded body sample having a thickness of 1 mm and a 3 cm square plate shape. The resin molding obtained here was thoroughly washed with pure water, and the amount of elution in water was measured by the antibacterial test method (plate-shaped) formulation and antibacterial test and underwater elution amount measurement. The results are shown in Table 1.

(Comparative Example 2)
PS resin was molded by a hot press method to obtain a resin molded body sample having a thickness of 1 mm and a 3 cm square plate shape. Thereafter, post-treatment was performed in the same manner as in Comparative Example 1, and various evaluations were made. The results are shown in Table 1.

(Comparative Example 3)
A PC resin was molded by a hot press method to obtain a resin molded body sample having a thickness of 1 mm and a 3 cm square plate shape. Thereafter, post-treatment was performed in the same manner as in Comparative Example 1, and various evaluations were made. The results are shown in Table 1.

(Comparative Example 4)
The laminated tube of the present invention is produced using a known coextrusion molding machine. That is, using the first extrusion molding machine, the innermost layer resin polyethylene resin (PE2) and the outermost layer ethylene-vinyl acetate copolymer resin (EVA) are heated and melted at a molding temperature in the range of 180 to 230 ° C. The inner tube made of ethylene vinyl alcohol resin with an inner diameter of 5 mm and a wall thickness of 0.2 mm is extruded through a common head die, and at the same time, the ethylene-vinyl acetate copolymer resin (EVA) is heated using a second extruder. If the outer layer tube made of ethylene-vinyl acetate copolymer resin having a thickness of 2.3 mm is extruded through the common head die at a molding temperature in the range of 160 to 220 ° C., the outer peripheral surface of the inner layer tube The two-layer tube of the present invention having an inner diameter of 5 mm and an outer diameter of 10 mm was obtained by continuously heat-fusing and bonding to each other.

  The two-layer tube was cut to a length of 50 cm, sealed (cap) on one side of the tube, filled with pure water, and sealed to prevent air from entering. The tube filled with pure water was irradiated with γ rays with a cobalt-60 radiation source to obtain a radiation-treated tube. The absorbed gamma ray dose was 25 kGy. The inside of the obtained radiation-treated tube was washed with 10 L of pure water, and antibacterial tests and measurement of the amount of elution in water, end surface peeling when pruning scissors were cut, and delamination when bent slightly were observed. The results are shown in Table 2.

  When comparing the various items in Examples 1-5, Comparative Examples 1-3 in Table 1, and Examples 6, 7 and Comparative Example 4 in Table 2, Examples 1-5 in Staphylococcus aureus and Escherichia coli in the antibacterial test. In contrast, Comparative Examples 1 to 3 have antibacterial activity values of less than 2 and no antibacterial activity.

  Moreover, when Examples 6 and 7 are compared with Comparative Example 4 in a tube-shaped sample, Examples 6 and 7 have antibacterial activity values of S. aureus and Escherichia coli at 2 or more, whereas Comparative Example 4 Has an antibacterial activity value of S. aureus and Escherichia coli of less than 2 and is not antibacterial. Example 7 was a sample in which an adhesive resin was blended with the outer layer tube of Example 6, but the adhesive force between the inner layer and the outer layer became stronger.

  Since the tube of the example has a high transmittance, the contents can be confirmed even when the tube is used.

Claims (6)

A method for producing an antibacterial resin molded article, which comprises irradiating a resin molded body containing a resin comprising a repeating unit of ethylene vinyl alcohol represented by the following chemical structural formula (1) with radiation. Manufacturing method of resin molding.

(Wherein the ratio of m to n is 0.1: 99.9 to 99.9: 0.1) The method for producing an antibacterial resin molded article according to claim 1, wherein the radiation is an electron beam and / or a gamma ray. The method for producing an antibacterial resin molded article according to claim 1 or 2, wherein the irradiation with radiation is performed in a state of contact with water. The method for producing an antibacterial resin molded article according to claim 3, wherein the alcohol is contained in the water. The method for producing an antibacterial resin molded article according to claim 4, wherein the alcohol has 3 or less carbon atoms. A liquid feeding hose for food and drink, comprising an antibacterial resin molded body produced by the method for producing an antibacterial resin molded body according to claim 1.