Antibacterial and antiviral treatment method for resin materials, method for producing antibacterial and antiviral resin materials, and antibacterial and antiviral resin materials

Abstract

To provide an antibacterial and antiviral treatment method of a resin material which can easily impart excellent antibacterial property and antiviral property to a resin material; a method for producing an antibacterial and antiviral resin material which includes a step of performing the antibacterial and antiviral treatment method; and an antibacterial and antiviral resin material which can be easily produced by the method for producing the antibacterial and antiviral resin material and has excellent antibacterial and antiviral properties.SOLUTION: There are provided an antibacterial and antiviral treatment method of a resin material which brings the surface of a resin material into contact with aqueous solution containing silver ions or a silver complex, then irradiating the surface with ionization radiation, and carrying and fixing silver nanoparticles containing 20 mass% or more of a silver oxide onto the surface of the resin material; a method for producing an antibacterial and antiviral material which includes a step of performing the antibacterial and antiviral treatment method; and an antibacterial and antiviral resin material which can be easily and inexpensively produced by the method for producing the antibacterial and antiviral material, and has excellent antibacterial and antiviral properties.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for antibacterial and antiviral treatment of a resin material, which is characterized by supporting and fixing silver oxide nanoparticles on the surface of the resin material to impart antibacterial and antiviral properties, a method for manufacturing an antibacterial and antiviral resin material including a step of carrying out the antibacterial and antiviral treatment method, and an antibacterial and antiviral resin material that can be manufactured by the method for manufacturing the antibacterial and antiviral resin material.

Background Art

[0002] In recent years, due to the spread of infectious diseases and the like, the demand for antibacterial and antiviral properties has increased, and it is desired to impart antibacterial and antiviral properties to various articles including daily necessities. Therefore, there is a desire to develop an antibacterial and antiviral treatment method that can efficiently impart antibacterial and antiviral properties to resin materials that are widely used as materials for forming various articles.

[0003] As a method for manufacturing an antibacterial resin material, Patent Document 1 discloses a method of blending an antibacterial agent containing silver, which is known as a component having an antibacterial effect, into a general-purpose resin material such as an ABS resin. However, since this method is a method of kneading and blending the antibacterial agent during the manufacturing process of the resin material, it is not a method of antibacterial treatment of the resin material after it is manufactured.

[0004] Patent Documents 2 and 3 disclose techniques for supporting and immobilizing noble metal nanoparticles on the surface of a resin material by electron beam irradiation. That is, Patent Document 2 discloses a method for manufacturing a plated resin molded article in which a solution of ions such as palladium or silver, which is a plating catalyst, is brought into contact with the surface of a resin material having an electroless plating layer, and electron beams and / or γ-rays are irradiated to support nanoparticles of a catalytic metal on the resin surface. Patent Document 3 discloses a method in which a solution containing platinum ions is brought into contact with a carrier made of a synthetic resin or the like, and then the carrier is irradiated with an electron beam to immobilize fine particles containing platinum on the surface of the carrier. However, these methods are not antibacterial treatment methods for resin materials aimed at antibacterial treatment of the surface of resin materials.

[0005] In addition, Patent Document 4 discloses a method for antibacterial treatment of fibers, which comprises immersing fibers in an aqueous solution containing noble metal ions such as silver or noble metal complexes, and irradiating the aqueous solution with γ-rays or electron beams. It has been confirmed that by this method, fine particles of metallic silver are fixed to the fibers, and a fiber material having an antibacterial effect due to the metallic silver can be obtained. As described above, noble metals such as metallic silver are known as components having an antibacterial effect, but silver oxide is known to have a more excellent antibacterial effect than noble metals such as metallic silver (Non-Patent Document 1).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Non-Patent Documents

[0007]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] As described above, for resin materials other than fiber materials, a method of performing antibacterial treatment after the resin material is manufactured with an antibacterial noble metal has not been conventionally known. Also, for fiber materials, a method of supporting and fixing an antibacterial agent mainly composed of silver oxide, which has a more excellent antibacterial effect than antibacterial noble metals such as metallic silver, to impart antibacterial properties has not been known.

[0009] The present invention aims to provide a method for antibacterial and antiviral treatment of a resin material, which can easily and inexpensively impart excellent antibacterial and antiviral properties to the resin material by supporting and fixing silver oxide or silver fine particles mainly composed of silver oxide on the resin material. Another object of the present invention is to provide a method for producing an antibacterial and antiviral resin material, which is characterized by including a step of carrying out the antibacterial and antiviral treatment method of the resin material. Still another object of the present invention is to provide an antibacterial and antiviral resin material that can be easily and inexpensively produced by the method for producing an antibacterial and antiviral resin material and has excellent antibacterial and antiviral properties.

Means for Solving the Problems

[0010] As a result of investigations to solve the above problems, the present inventors have found that by bringing the surface of a resin material into contact with an aqueous solution containing silver ions or a silver complex and then irradiating the surface with ionizing radiation, silver nanoparticles containing silver oxide can be supported and fixed on the surface of the resin material. As a result, antibacterial and antiviral properties can be imparted to the surface of the resin material, and an antibacterial and antiviral resin material can be produced, thus completing the present invention. That is, the above problems of the present invention can be solved by the following configuration.

[0011] A first aspect of the present invention is a method for antibacterial and antiviral treatment of a resin material, which comprises bringing the surface of the resin material into contact with an aqueous solution containing silver ions or a silver complex, and then irradiating the surface with ionizing radiation to support and fix silver nanoparticles containing 20% by mass or more of silver oxide on the surface of the resin material. The silver nanoparticles containing 20% by mass or more of silver oxide mean that 20% by mass or more of the silver in the silver nanoparticles is silver oxide. The same applies to the mass% of the silver oxide content shown below.

[0012] The second of the present invention is the first preferred embodiment of the present invention, wherein the resin material is acrylonitrile-butadiene-styrene resin (ABS), polycarbonate (PC), polypropylene (PP), polyethylene (PE), or polyvinyl chloride (PVC), and it is an antibacterial and antiviral treatment method for resin materials.

[0013] The third of the present invention is the first preferred embodiment of the present invention, wherein the resin material is a fluororesin, and it is an antibacterial and antiviral treatment method for resin materials. Representative fluororesins include polytetrafluoroethylene resin (PTFE).

[0014] The fourth of the present invention is the second or third preferred embodiment of the present invention, wherein the aqueous solution is an alcohol-water solution containing 8% by volume or less of a branched lower alcohol having 2 to 5 carbon atoms, and it is an antibacterial and antiviral treatment method for resin materials.

[0015] The fifth of the present invention is the first to fourth preferred embodiments of the present invention, wherein the ionizing radiation is an electron beam, and it is an antibacterial and antiviral treatment method for resin materials.

[0016] The sixth of the present invention is the first to fifth of the present invention, and it is an antibacterial and antiviral treatment method for resin materials, characterized in that it is an antibacterial treatment method.

[0017] The seventh of the present invention is the first to fifth of the present invention, and it is an antibacterial and antiviral treatment method for resin materials, characterized in that it is an antiviral treatment method.

[0018] The eighth of the present invention is a method for manufacturing an antibacterial and antiviral resin material, characterized by including the step of implementing the antibacterial and antiviral treatment method for the resin material according to the first to seventh of the present invention.

[0019] The ninth of the present invention is an antibacterial and antiviral resin material, characterized in that silver nanoparticles containing 20% by mass or more of silver oxide are fixedly supported on its surface.

[0020] The tenth aspect of the present invention is an antibacterial and antiviral resin material, characterized in that silver nanoparticles containing 60% by mass or more of silver oxide are fixedly supported on the surface thereof.

[0021] The eleventh aspect of the present invention is an antibacterial and antiviral resin material, characterized in that silver nanoparticles containing 80% by mass or more of silver oxide are fixedly supported on the surface thereof.

Effects of the Invention

[0022] By the antibacterial and antiviral treatment method of the resin materials of the first to seventh aspects of the present invention, excellent antibacterial property and / or antiviral property can be imparted to resin materials used as materials for various articles, etc. at low cost by an easy procedure. The manufacturing method of the antibacterial and antiviral resin material of the present invention is a method including a step of carrying out the above antibacterial and antiviral treatment method, and can easily and inexpensively manufacture a resin material having excellent antibacterial property and / or antiviral property. The antibacterial and antiviral resin material of the present invention that can be manufactured by the manufacturing method of the antibacterial and antiviral resin material described above exhibits antibacterial and antiviral properties superior to those of conventional resin materials, and is suitably used as a material for various articles including fiber materials and daily necessities, etc.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0024] The antibacterial and antiviral treatment method of the resin material means a method of imparting antibacterial property for suppressing the growth of bacteria or antiviral property for suppressing the growth of viruses, or antibacterial property and antiviral property to the resin material. As described above, the method for antibacterial and antiviral treatment of the resin material of the present invention is a step of bringing the surface of the resin material to be treated into contact with an aqueous solution containing silver ions or a silver complex, and after the step of bringing them into contact, it includes a step of irradiating the surface of the resin material with ionizing radiation, characterized in that the irradiation with the ionizing radiation is carried out under the condition that silver nanoparticles containing 20% by mass or more of silver oxide are supported and fixed on the surface of the resin material.

[0025] In this treatment method, as a method of bringing the surface of the resin material into contact with an aqueous solution containing silver ions or a silver complex, as long as it is a method capable of uniformly covering the entire portion of the surface of the resin material where antibacterial and antiviral properties are intended to be imparted with the aqueous solution, it is not particularly limited. For example, a method of immersing the resin material in an aqueous solution, a method of putting the resin material and the aqueous solution in a sealed container, for example, in a plastic bag, and shaking the sealed container to wet the surface of the resin material with the aqueous solution, a method of applying or spraying the aqueous solution on the surface of the resin material to wet the surface of the resin material with the aqueous solution, etc. can be mentioned. In the case where the resin material is a fiber product such as a thread, a woven fabric, or a knitted fabric, a method in which the entire surface of the fibers forming these is brought into contact with the aqueous solution is preferable. Also, when imparting antibacterial and antiviral properties only to a part of the surface of the resin material, a method in which only the said part is brought into contact with the aqueous solution may be used.

[0026] Examples of the form of the resin material to be subjected to antibacterial and antiviral treatment include a plate shape, a rod shape, a bulk shape, etc., and are not particularly limited. Also, fibrous resins, threads formed by aggregating fibrous resins in a long and thin shape, woven fabrics woven from the said threads, knitted fabrics, etc. are also included in the resin materials to be treated in the present invention.

[0027] As the resin material to which the antibacterial and antiviral treatment method of the resin material of the present invention is applied, there is no particular limitation as long as it is used as a material of an article for which imparting antibacterial and antiviral properties is desired. It may be either a thermoplastic resin or a thermosetting resin, and may be a material with a rough surface or a smooth surface. The treatment method of the present invention can also be applied to porous materials and fibrous materials as described above.

[0028] Among them, the present invention is preferably applied to the antibacterial and antiviral treatment of ABS, PC, PP, PE, and PVC. In addition, the present invention is also preferably applied to the antibacterial and antiviral treatment of fluororesins such as PTFE.

[0029] As the aqueous solution containing silver ions or silver complexes, an aqueous solution obtained by dissolving a water-soluble silver salt such as silver nitrate, NH 3 added to make [Ag(NH 3 ) 2 + , diamminesilver(I) ion, an aqueous solution obtained by dissolving silver complex ions such as [Ag(S 2 O 3 ) 2 3- , and bis(thiosulfato)silver ion can be mentioned.

[0030] After bringing the surface of the resin material into contact with the aqueous solution as described above, the surface of the resin material is irradiated with ionizing radiation. By this irradiation, silver nanoparticles containing silver oxide are deposited, and the silver nanoparticles are supported and fixed on the surface of the resin material. As a result, the resin material is subjected to antibacterial and antiviral treatment. Examples of the ionizing radiation used for irradiation include high-energy electromagnetic waves such as γ-rays and charged particle beams such as electron beams. Among them, γ-rays and electron beams are preferable, and in particular, electron beams are preferably used because the devices and equipment for irradiation are relatively inexpensive and the operation and control are easy.

[0031] Ionizing radiation irradiation is performed under the condition that silver nanoparticles containing 20% by mass or more of silver oxide are supported and fixed on the surface of the resin material by irradiation. Here, silver oxide refers to AgO and Ag 2 ​​It means including any of them. That is, for the silver oxide to be supported and fixed, when it consists only of AgO, Ag 2 when it consists only of Ag₂O, AgO and Ag 2 when it consists of Ag₂O is also included. Also, the process of forming silver oxide from silver ions or silver complex ions in an aqueous solution is not particularly limited. That is, when it is formed by the reaction of silver ions or silver complex ions with water molecules, when it is formed by the reaction with oxygen in the air, when it is formed by the reaction with the resin material forming the resin material, etc., as long as silver oxide is supported and fixed on the surface of the resin material, any process may be used.

[0032] By supporting and fixing silver nanoparticles containing 20% by mass or more of silver oxide on the surface of the resin material, antibacterial and antiviral properties superior to those when supporting and fixing metal silver nanoparticles or silver nanoparticles with a silver oxide content ratio of less than 20% by mass can be obtained. When the silver nanoparticles contain 60% by mass or more of silver oxide, more excellent antibacterial and antiviral properties can be obtained, and when they contain 80% by mass or more of silver oxide, even more excellent antibacterial and antiviral properties can be obtained, so it is preferable.

[0033] By setting the concentration of silver ions or silver complex ions in the aqueous solution containing silver ions or silver complex ions to 10 mM or less, the silver nanoparticles supported and fixed on the surface of the resin material can be made to contain 20% by mass or more of silver oxide. The lower the concentration of silver ions or silver complex ions, the higher the proportion of silver oxide. Therefore, by adjusting the concentration of silver ions or silver complex ions, silver nanoparticles with a higher proportion of silver oxide can be obtained. Therefore, more preferably, the concentration of silver ions or silver complex ions is 5 mM or less, and even more preferably 3 mM or less. On the other hand, when the concentration of silver ions or silver complex ions is too low, the amount of silver nanoparticles to be supported decreases, and the desired antibacterial and antiviral effects cannot be obtained. Therefore, the concentration is 0.1 mM or more, more preferably 0.2 mM or more, and even more preferably 0.5 mM or more.

[0034] When the solvent of the aqueous solution is only water, depending on the type of resin material, it may be difficult for the aqueous solution to uniformly wet the entire surface of the resin material. Adding a water-soluble organic solvent to the aqueous solution may make it easier to wet the entire surface of the resin material, but depending on the type of organic solvent, it may be considered to inhibit the imparting of antibacterial and antiviral properties. When the organic solvent is a branched lower alcohol having 2 to 5 carbon atoms and the addition amount thereof is 8% by volume or less in the aqueous solution, it is considered preferable because there is no inhibition of antibacterial and antiviral properties. More preferably, it is 2% by volume or less.

[0035] Examples of the branched lower alcohol having 2 to 5 carbon atoms include ethanol, 2-propanol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol, 2-pentanol, 3-pentanol, methyl-1-butanol, methyl-2-butanol, ethylene glycol, glycerin, etc. Among them, primary alcohols are preferred, and 2-propanol is particularly preferred.

[0036] Examples of the bacteria whose growth is suppressed by the antibacterial and antiviral treatment method of the resin material of the present invention include both Gram-positive bacteria such as Staphylococcus aureus and Gram-negative bacteria such as Escherichia coli. Among them, Staphylococcus aureus and Escherichia coli are mentioned as the bacteria to which the treatment method of the present invention is preferably applied. In addition, examples of the virus whose growth is suppressed by the antibacterial and antiviral treatment method of the resin material of the present invention include both enveloped viruses such as influenza virus and coronavirus, and non-enveloped viruses such as feline calicivirus and norovirus.

[0037] The method for producing the antibacterial and antiviral resin material of the present invention includes the step of performing the antibacterial and antiviral treatment method of the resin material described above.

[0038] The antibacterial and antiviral resin material of the present invention is characterized in that silver nanoparticles containing 20% by mass or more of silver oxide are fixedly supported on the surface of the resin material, and it is a material having excellent antibacterial and antiviral properties. Therefore, an article manufactured using this resin material as a constituent material has excellent antibacterial and antiviral properties and is suitably used as daily necessities, clothing, building materials, etc. The antibacterial and antiviral resin material of the present invention can be manufactured by the method for manufacturing the antibacterial and antiviral resin material of the present invention described above.

Examples

[0039] Hereinafter, embodiments of the present invention will be described based on the examples described below. However, the scope of the present invention is not limited by the following examples, and it should be understood that various modifications within the same and equivalent ranges as the claims are also included.

[0040] Example 1 Antibacterial treatment of ABS resin 1) Process of antibacterial treatment An acrylonitrile-butadiene-styrene resin plate ABSN-100-3 manufactured by AS ONE Corporation, cut into a size of 50 mm in length × 50 mm in width × 3 mm in thickness (resin material: hereinafter, sometimes simply referred to as "ABS resin plate 1") was subjected to antibacterial treatment in the following process (Steps 1 to 4). The flow of the antibacterial treatment process is shown in FIG. 1.

[0041] Step 1 ((a) in FIG. 1) After washing ABS resin plate 1 with Solmix (a mixed solvent mainly composed of ethyl alcohol: Nippon Alcohol Sales Co., Ltd.) to remove deposits on the surface such as grease, it was further washed with ultrapure water. Step 2 ((b) in FIG. 1) After sealing the washed ABS resin plate 1 and 20 mL of the raw material solution 3 shown in Table 1 below in a vinyl bag 2, it was left overnight in a sealed state to wet the entire surface of ABS resin plate 1 with the raw material solution 3. Step 3 The ABS resin plate 1 and the raw material solution 3 are sealed in a vinyl bag, and electron beam irradiation is performed under the conditions of 4.8 MeV and a dose rate of 20 kGy using an electron beam irradiation device (Dynamitron type 5 MeV electron accelerator manufactured by DI). The fourth step ((c) in Fig. 1) After electron beam irradiation, the ABS resin plate 1 is taken out from the vinyl bag, washed with ultrapure water, and a sample for the following antibacterial test and antiviral test is obtained.

[0042] (Raw material solution) Silver nitrate was dissolved in water or alcohol water in which 1 vol% of 2-propanol was added to water, and the final concentration was adjusted to 1 mM (1 mmol%) to prepare the raw material solution (aqueous solution containing silver ions or silver complexes) shown in Table 1. Note that "Ag / ABS" in Table 1 indicates that silver is supported and fixed on the surface of the ABS resin plate 1. The same applies hereinafter.

[0043]

Table 1

[0044] Hereinafter, the ABS resin plate 1 that has been antibacterial treated in the above process (the first to fourth steps) using the raw material solution 1 is represented as "Ag / ABS-2p without", and the ABS resin plate 1 that has been antibacterial treated in the above process (the first to fourth steps) using the raw material solution 2 is represented as "Ag / ABS-2p with".

[0045] (ICP emission analysis) ICP emission analysis (high-frequency inductively coupled plasma optical emission spectrometry) is a method in which plasma energy is externally applied to an analysis sample to excite the contained component elements (atoms), and the emission lines (spectral lines) emitted when the excited atoms return to a lower energy level are measured, and the amount of the component elements can be determined from the measurement results. By ICP emission analysis, the amount of silver supported per 1 cm of the ABS resin plate 1 after the above antibacterial treatment is shown in Table 2 below. 2 The results of determining the silver loading amount per 1 cm of the ABS resin plate 1 after the antibacterial treatment are shown in Table 2 below.

[0046]

Table 2

[0047] (X-ray Photoelectron Spectroscopy (XPS)) For Ag / ABS-2p without, XPS measurement was performed using a scanning X-ray photoelectron spectrometer Quantum 2000 manufactured by ULVAC-PHI, Inc. The measured Ag3d spectrum showed a peak near 377.6 eV, and the silver supported on Ag / ABS-2p without was considered to be supported as silver oxide with high antibacterial properties, AgO or Ag 2 O. And from the results of this Ag3d spectrum, at least 80% by mass of the silver supported and fixed on the ABS resin plate 1 treated by the above-mentioned first to fourth steps is considered to be AgO or Ag 2 O. Also, it is considered that silver nanoparticles containing 20% by mass or more of AgO and / or Ag 2 O can be supported and fixed on the surface of the resin material by a method and conditions according to the above-mentioned first to fourth steps.

[0048] 2) Antibacterial test (Resin material to be tested (specimen)) · Polyethylene film (the same size as the ABS resin plate 1: denoted as "unprocessed test piece") · ABS resin plate 1 not subjected to antibacterial treatment (the above process: first to fourth steps) (denoted as "ABS resin plate (unprocessed)") · ABS resin plate 1 when only the first step, the third step (electron beam irradiation), and the fourth step were performed without performing the step of wetting the surface of the ABS resin plate 1 with the raw material solution (the second step) (denoted as "ABS resin plate (EB only)") · Ag / ABS-2p without · Ag / ABS-2p with

[0049] (Bacterial species to be subjected to antibacterial treatment) Staphylococcus aureus, Escherichia coli

[0050] (Method of antibacterial test) For each of the resin materials (specimens) to be tested, an antibacterial test was conducted by the film adhesion method (JIS Z 2801) to evaluate the antibacterial performance. The outline of the test process of the film adhesion method (JIS Z 2801) is shown in Figure 2. In addition, the specific test process and conditions are shown below.

[0051] First step: 0.4 mL of bacterial solution 4 (a solution containing 6.1×10 5 CFU / mL of the bacteria to be subjected to antibacterial treatment) was dropped onto the surface of the resin material (specimen) 1 to be tested (see Figure 2(a)). Second step: The surface of the specimen onto which the bacterial solution 4 was dropped was covered with an adhesion film 5 (a polyethylene film: 40 mm long × 40 mm wide) to spread the bacterial solution 4 evenly (see Figure 2(b)). Third step: After culturing the bacteria for 24 hours, the bacterial solution was collected with a dropper 6 or the like and the viable cell count was measured (see Figure 2(c)).

[0052] (Antibacterial test results) The results of the antibacterial test measured as described above are shown in Tables 3 to 5 below. Table 3 shows the antibacterial test results of the above specimens (unprocessed test pieces, ABS resin plates (unprocessed), ABS resin plates (only EB), Ag / ABS-2p present) against Staphylococcus aureus. Table 4 shows the antibacterial test results of the above specimens (unprocessed test pieces, ABS resin plates (unprocessed), ABS resin plates (only EB), Ag / ABS-2p present) against Escherichia coli. Table 5 shows the antibacterial test results of the above specimens (unprocessed test pieces, Ag / ABS-2p absent) against Escherichia coli.

[0053] In the table, the logarithmic mean value of the viable cell count ( / cm 2 ) indicates the average of the logarithmic values of the viable cell count per 1 cm 2 . For example, in the case of the unprocessed test piece for Staphylococcus aureus in Table 3, the viable cell count before culturing (immediately after contact) is 10 to the 4.19th power on average.

[0054]

Table 3

[0055]

Table 4

[0056]

Table 5

[0057] In Tables 3 to 5, the antibacterial activity value [R] is a value calculated by subtracting the logarithmic mean value At of the viable cell count after 24-hour culture of other specimens from the logarithmic mean value Ut of the viable cell count after 24-hour culture of the unprocessed test piece, that is, [R]=Ut - At, and it is a value of an index for determining the degree of antibacterial effect defined by the film adhesion method (JIS Z2801). According to the antibacterial performance standard defined by the Japan Hygienic Materials Industry Association, it is considered to have antibacterial properties when the antibacterial activity value [R]≧2.0.

[0058] In the antibacterial test results against Staphylococcus aureus shown in Table 3, in the case of Ag / ABS-2p with antibacterial treatment by the antibacterial and antiviral treatment method of the resin material of the present invention, after 24-hour culture, At < -0.20 and the antibacterial activity value [R]≒5.0, showing antibacterial performance significantly higher than the antibacterial activity value [R]≧2.0 of the antibacterial performance standard. In the case of the ABS resin plate 1 (ABS resin plate (EB only)) that only underwent electron beam irradiation without performing the step of wetting the surface of the ABS resin plate 1 with the raw material solution, after 24-hour culture, At = 0.70 and the antibacterial activity value [R]=4.1. In this case as well, it has antibacterial performance significantly higher than the antibacterial activity value [R]≧2.0 of the antibacterial performance standard. It can be said that the ABS resin plate has high antibacterial performance even without antibacterial treatment, but in the case of Ag / ABS-2p with electron beam irradiation after wetting the surface of the ABS resin plate 1 with the raw material solution, it can be said that it has more excellent antibacterial performance.

[0059] In the antibacterial test results against Escherichia coli shown in Table 4, in the case of Ag / ABS-2p with antibacterial treatment by the antibacterial and antiviral treatment method of the resin material of the present invention, after 24 hours of culture, At < -0.20 and the antibacterial activity value [R] ≧ 5.9, showing antibacterial performance significantly higher than the antibacterial activity value [R] ≧ 2.0 of the antibacterial performance standard. On the other hand, in the case of the unprocessed ABS resin plate 1 (ABS resin plate (unprocessed)), after 24 hours of culture, At = 4.23 and the antibacterial activity value [R] = 1.5. Also, in the case of the ABS resin plate 1 (ABS resin plate (EB only)) that only underwent electron beam irradiation without performing the step of wetting the surface of the ABS resin plate 1 with the raw material solution, after 24 hours of culture, At = 3.98 and the antibacterial activity value [R] = 1.7, which is smaller than the antibacterial activity value [R] ≧ 2.0 of the antibacterial performance standard. From the results shown in Table 4, it is shown that the antibacterial and antiviral treatment method of the resin material of the present invention can impart a dramatically high antibacterial performance to the resin material made of ABS resin against Escherichia coli.

[0060] In the antibacterial test results against Escherichia coli shown in Table 5, in the case of Ag / ABS-2p without antibacterial treatment by the antibacterial and antiviral treatment method of the resin material of the present invention, after 24 hours of culture, At < -0.20 and the antibacterial activity value [R] ≧ 6.3, showing antibacterial performance significantly higher than the antibacterial activity value [R] ≧ 2.0 of the antibacterial performance standard. That is, from the results of Table 5, it is shown that when imparting antibacterial performance against Escherichia coli to ABS resin by the antibacterial and antiviral treatment method of the resin material of the present invention, regardless of the presence or absence of branched lower alcohol in the raw material solution (aqueous solution containing silver ions or silver complexes), a dramatically high antibacterial performance can be obtained.

[0061] As described above, from Tables 3 to 5, when the surface of the ABS resin plate 1 is brought into contact with a raw material solution containing silver ions or silver complexes through the first to fourth steps shown in FIG. 1 and irradiated with ionizing radiation to support and fix silver nanoparticles mainly composed of silver oxide on the surface of the ABS resin plate 1, regardless of the presence or absence of branched lower alcohol in the raw material solution, viable bacteria such as Escherichia coli can be completely killed or significantly reduced, and it is shown that the general-purpose ABS resin plate 1 can be made into an ABS resin plate 1 having high antibacterial properties (bactericidal properties). Regardless of the presence or absence of branched lower alcohols in the raw material solution, since it has high antibacterial properties, it is a resin material other than ABS resin. Even when it is difficult to wet the entire surface with an aqueous solution when contacted with the aqueous solution and the addition of an organic solvent is required to wet the entire surface with the aqueous solution, it is presumed that high antibacterial properties can be obtained by adding a branched lower alcohol to the raw material solution and applying the treatment method of the present invention.

[0062] Example 2 Antibacterial treatment of PC, PP, PE, and PVC 1) Process of antibacterial treatment Resin plates of PC, PP, PE, and PVC cut into 50 mm in length × 50 mm in width × 3 mm in thickness (resin materials) were subjected to antibacterial treatment by the same process as in Example 1 (Steps 1 to 4: Figure 1). As the raw material solutions, 1 mM silver nitrate aqueous solution (raw material solution 1) and a solution in which silver nitrate was dissolved in water + 2-propanol (10 vol%) at a concentration of 1 mM (raw material solution 3) were used.

[0063] 2) Antibacterial test (Resin materials (specimens) to be tested) · Polyethylene film (the same size as ABS resin plate 1: referred to as "unprocessed test piece") · Resin plates of PC, PP, PE, and PVC that have not been subjected to antibacterial treatment (each referred to as "control PC", "control PP", "control PE", and "control PVC") · Resin plates of PC, PP, PE, and PVC that have been subjected to antibacterial treatment by the above antibacterial treatment process using raw material solution 1 (each referred to as "Ag / PC-2p without", "Ag / PP-2p without", "Ag / PE-2p without", and "Ag / PVC-2p without") · Resin plates of PC, PP, PE, and PVC that have been subjected to antibacterial treatment by the above antibacterial treatment process using raw material solution 3 (each referred to as "Ag / PC-2p with", "Ag / PP-2p with", "Ag / PE-2p with", and "Ag / PVC-2p with")

[0064] (Method of antibacterial test) For each of the resin materials (specimens) to be tested, in the same manner as in Example 1, an antibacterial test was conducted by the film adhesion method (JIS Z 2801) to evaluate the antibacterial performance. The specific conditions of the test are shown below. Test bacterial species: Escherichia coli Viable cell count of the test bacterial solution: 5.7×10 5 (CFU / mL) Bacterial solution preparation solution: 1 / 500 NB medium Inoculation amount of the test bacterial solution: 0.4 ml Purification of the test piece: After gently wiping the entire surface of the test piece with absorbent gauze soaked with ethanol with a purity of 99% or more, it was dried thoroughly.

[0065] (Antibacterial test results) The results of the antibacterial test measured as described above are shown in Table 6 below. In Table 6, the logarithmic mean value of the viable cell count ( / cm 2 ) is, in the same manner as in Tables 3 to 5, the average of the logarithmic values of the viable cell count per 1 cm 2 and indicates the average of the logarithmic values of the viable cell count per 1 cm.

[0066]

Table 6

[0067] In the antibacterial test results shown in Table 6, in the cases of Ag / PC-2p without, Ag / PP-2p without, Ag / PE-2p without, Ag / PVC-2p without, Ag / PC-2p with, Ag / PP-2p with, Ag / PE-2p with, and Ag / PVC-2p with where the resin materials of the present invention were subjected to antibacterial treatment by the antibacterial and antiviral treatment method, after 24-hour culture, At < -0.20 and the antibacterial activity value [R] ≥ 6.1, which is significantly larger than the antibacterial activity value [R] ≥ 2.0 of the antibacterial performance standard. That is, even when the resin to be treated is PC, PP, PE, or PVC, it is shown that high antibacterial performance can be obtained by subjecting the resin materials of the present invention to antibacterial treatment by the antibacterial and antiviral treatment method regardless of the presence or absence of 2-propanol in the raw material solution. On the other hand, in the case of PC, PP, PE, and PVC without antibacterial treatment (control PC, PP, PE, PVC), the At values after 24-hour culture are 5.64, 5.76, 4.80, and 5.55, respectively, and the antibacterial activity values [R] are 0.2, 0.1, 1.1, 0.3, and 0.1, respectively, which are smaller than the antibacterial activity value [R] ≥ 2.0 of the antibacterial performance standard. From the results shown in Table 6, it is shown that the antibacterial and antiviral treatment method of the resin material of the present invention can impart a dramatically high antibacterial performance against Escherichia coli to the resin materials of PC, PP, PE, and PVC, and resin materials having high antibacterial properties (bactericidal properties) can be produced from these resin materials.

[0068] Example 3 Antibacterial treatment of polytetrafluoroethylene resin (PTFE) 1) Antibacterial treatment process A PTFE porous membrane (Temesh S-NTF1133) with a thickness of 80 μm manufactured by Nitto Denko Corporation, cut into a size of 50 mm in length × 50 mm in width (resin material: hereinafter, sometimes simply referred to as "PTFE membrane"), was subjected to antibacterial treatment in the flow shown in FIG. 1 (the first to fourth steps) in the same manner as above. However, in the second step of immersing the washed PTFE membrane in the raw material solution and sealing it in a vinyl bag (FIG. 1(b)), the PTFE membrane was immersed in 2-propanol, 2.0 mM-(AgNO 3 ) / (60 mass% 2-propanol aqueous solution, 2.0 mM-(AgNO 3 ) / aqueous solution, in this order, and sealed in a vinyl bag. This is because if the PTFE membrane is simply immersed in the silver nitrate (AgNO 3 ) solution as the raw material solution, the entire surface cannot be wetted with the raw material solution like the above-mentioned ABS resin plate 1, and silver nanoparticles cannot be uniformly supported on the surface. Therefore, the treatment of contacting with 2-propanol as an organic solvent was performed. In addition, in the third step, electron beam irradiation was performed under the conditions of 4.8 MeV and a dose rate of 20 kGy in the same manner as in Example 1 (in the case of the ABS resin plate 1).

[0069] 2) Antibacterial test (Resin material (specimen) to be tested) · Polyethylene film (same size as the ABS resin plate 1: referred to as "unprocessed test piece") · PTFE film that has undergone the antibacterial treatment process (referred to as "antibacterial-treated PTFE film") · PTFE film that has not undergone the antibacterial treatment process (referred to as "untreated PTFE film")

[0070] (Bacterial species to be antibacterial-treated) Staphylococcus aureus, Escherichia coli

[0071] (Methods and results of antibacterial tests) Similar to Example 1 (ABS resin plate 1), antibacterial evaluation was carried out by the film adhesion method (JIS Z 2801) shown in Fig. 2. Similar to Example 1 (ABS resin plate 1), the viable cell count was measured in the steps shown in Figs. 2(a), (b), and (c), and the logarithmic mean value ( / cm 2 ) was obtained. The antibacterial activity value [R], which is the value obtained by subtracting the logarithmic mean value At of the viable cell count of other specimens after 24-hour culture from the logarithmic mean value Ut of the viable cell count of the unprocessed test piece after 24-hour culture, i.e., [R]=Ut - At, was determined. The results are shown in Table 7 below.

[0072]

Table 7

[0073] As shown in Table 7, in the case of the antibacterial-treated PTFE film, the antibacterial activity value [R] is 4.7 or more against Staphylococcus aureus and 6.4 or more against Escherichia coli. For any bacterial species, the antibacterial activity value [R] of the antibacterial performance standard is significantly larger than [R]≥2.0, indicating that the antibacterial-treated PTFE film has extremely high antibacterial performance. On the other hand, in the case of the untreated PTFE film, the antibacterial activity value [R] is 0.0 against Staphylococcus aureus and 0.2 against Escherichia coli, which is significantly smaller than the antibacterial activity value [R]≥2.0 of the antibacterial performance standard, and it can be said that it has almost no antibacterial performance.

[0074] Example 4 Antiviral Treatment of ABS Resin 1) Antiviral treatment process An antiviral treatment was performed on one ABS resin plate using the same process (the first to fourth steps) as the antibacterial treatment process in Example 1. However, as the aqueous solution (raw material solution) containing silver ions or a silver complex, silver nitrate was dissolved in water, alcohol water in which 1 vol% of 2-propanol was dissolved, or alcohol water in which 10 vol% of 2-propanol was dissolved, and the one adjusted to a final concentration of 1 mM (mmol%) was used.

[0075] The ABS resin plate 1 subjected to the antiviral treatment using water as the raw material solution is designated as "Ag / ABS-2p none", the ABS resin plate 1 subjected to the antiviral treatment using alcohol water in which 1 vol% of 2-propanol is dissolved is designated as "Ag / ABS-2p1%", and the ABS resin plate 1 subjected to the antiviral treatment using alcohol water in which 10 vol% of 2-propanol is dissolved is designated as "Ag / ABS-2p10%".

[0076] 2) Antiviral property test (Resin material (specimen) to be tested) · Polyethylene film (the same size as the ABS resin plate 1: designated as "unprocessed test piece"). · Ag / ABS-2p10% · Ag / ABS-2p1% · Ag / ABS-2p none

[0077] (Virus to be subjected to antiviral treatment) Influenza A virus (H3N2) (A / HongKong / 8 / 68; TCadapted ATCC-1679) (Test virus solution concentration) 1.2×10 7 PFU / ml (PFU: plaque forming units)

[0078] (Method for antiviral property test) The antiviral test was conducted and the antiviral performance was evaluated in accordance with ISO 21702 "Measurement of antiviral activity on plastics and other non-porous surfaces". The specific process and conditions of the ISO 21702 test are shown below.

[0079] Step 1: Infect the host cells (MDCK cells (dog kidney-derived cells)) with the virus. After culturing, remove the cell debris by centrifugation to obtain a virus suspension. Step 2: Dilute the virus suspension obtained in Step 1 10-fold with sterilized distilled water and adjust it to 1 - 5×10 7 PFU / mL to obtain a test virus suspension. Step 3: Place each specimen (the resin material to be tested) on the bottom of a sterilized petri dish with the processed surface facing up, and inoculate 0.4 mL of the test virus suspension 1. (See Fig. 2(a)) Step 4: Cover the surface of the resin material of the specimen with an adhesion film 5 (polyethylene film: 40 mm long × 40 mm wide), and gently press and cover it so that the test virus suspension 4 spreads evenly over the entire film. (See Fig. 2(b)) Step 5: Cover the petri dish with its lid, leave it standing at 25°C for 24 hours, and then add 10 mL of a washing solution (SCDLP medium) to each specimen. Step 6: After washing out the virus by rubbing the surface of each test specimen and the adhesion film, measure the virus infectious titer (PFU / cm 2 ) by the plaque measurement method. (For the unprocessed test pieces, measure also before leaving standing for 24 hours (before culturing).)

[0080] (Antiviral test results) For each of the resin materials (specimens) to be tested, the virus infectious titer (PFU / cm 2The common logarithm average value of ) is shown in Table 8. The antiviral activity value [R] shown in the rightmost column of Table 8 is the number obtained by subtracting the common logarithm average value At of the virus infectivity titer after 24-hour culture of the antiviral-treated product from the common logarithm average value Ut of the virus infectivity titer after 24-hour culture of the unprocessed test piece, that is, [R]=Ut - At. Similar to the case of the antibacterial activity value [R], it is the value of the index for determining the degree of antiviral effect defined in the above ISO21702. According to the SEK mark certification standard of the Fiber Evaluation Technology Council, it is considered to have antiviral properties when the antiviral activity value 3.0>[R]≧2.0, and to have very high antiviral properties when [R]≧3.0.

[0081]

Table 8

[0082] As shown in Table 8, in the case of Ag / ABS-2p10% subjected to the above antiviral treatment using a raw material solution with a large amount of 2-propanol added to water, the antiviral activity value [R] is 1.8, which is smaller than the antiviral activity value [R]≧2.0 at which antiviral properties are recognized according to the antiviral performance standard, indicating that it does not have antiviral properties as recognized by the antiviral performance standard.

[0083] On the other hand, in the case of Ag / ABS-2p1% subjected to the above antiviral treatment using a raw material solution with a reduced amount of 2-propanol added, the antiviral activity value [R] is 2.0, satisfying the antiviral activity value [R]≧2.0 at which antiviral properties are recognized according to the antiviral performance standard. Furthermore, in the case of Ag / ABS-2p without (2-propanol added) subjected to the above antiviral treatment using a raw material solution without 2-propanol added, the antiviral activity value [R] is 3.1, satisfying the antiviral activity value [R]≧3.0 at which very high antiviral properties are recognized according to the antiviral performance standard, indicating that it has very high antiviral properties.

[0084] From the results shown in Table 8, by supporting and fixing silver nanoparticles mainly composed of silver oxide on the surface of resin materials such as ABS by the antibacterial and antiviral treatment method of the resin material of the present invention, excellent antiviral properties are imparted to the resin material, and it is shown that a resin material having excellent antiviral properties can be produced.

[0085] On the other hand, depending on the type of resin material, it may be difficult to uniformly wet the entire surface with the raw material solution. This problem can be solved by adding a branched lower alcohol having 2 to 5 carbon atoms to the raw material solution. However, from the results shown in Table 8, increasing the concentration of 2-propanol added to the raw material solution to about 10% by volume is not preferable because it reduces the antibacterial and antiviral effects. From the results shown in Table 8, the concentration of 2-propanol added to the raw material solution should be 8% by volume or less, and more preferably 2% by volume or less.

Explanation of Symbols

[0086] 1 Resin material (specimen) 2 Vinyl back 3 Raw material solution 4 Bacterial solution (or test virus suspension) 5 Adhesive film 6 Pipette

Claims

1. A method for antibacterial or antiviral treatment of a resin material, which is a resin plate of acrylonitrile-butadiene-styrene, comprising contacting the surface of the resin material with an aqueous solution containing silver ions or a silver complex, and then irradiating the surface with ionizing radiation to support and fix silver nanoparticles, in which 20% by mass or more of the silver in the particles is silver oxide, on the surface of the resin material.

2. The method for antibacterial or antiviral treatment of a resin material according to Claim 1, wherein the aqueous solution is an aqueous alcohol solution containing 8% by volume or less of ethanol and / or a branched lower alcohol having 3 to 5 carbon atoms.

3. The method for antibacterial or antiviral treatment of a resin material according to Claim 1 or Claim 2, wherein the ionizing radiation is an electron beam.

4. The method for antibacterial or antiviral treatment of a resin material according to any one of Claims 1 to 3, which is an antibacterial treatment method.

5. The method for antibacterial or antiviral treatment of a resin material according to any one of Claims 1 to 3, which is an antiviral treatment method.

6. A method for producing an antibacterial or antiviral resin material, comprising a step of performing the method for antibacterial or antiviral treatment of a resin material according to any one of Claims 1 to 5.

7. An antibacterial or antiviral resin material, which is a resin material that is a resin plate of acrylonitrile-butadiene-styrene, and silver nanoparticles, in which 20% by mass or more of the silver in the particles is silver oxide, are fixedly supported on the surface of the resin material.

8. An antibacterial or antiviral resin material, which is a resin material that is a resin plate of acrylonitrile-butadiene-styrene, and silver nanoparticles, in which 60% by mass or more of the silver in the particles is silver oxide, are fixedly supported on the surface of the resin material.

9. An antibacterial or antiviral resin material, which is a resin material that is a resin plate of acrylonitrile-butadiene-styrene, and silver nanoparticles, in which 80% by mass or more of the silver in the particles is silver oxide, are fixedly supported on the surface of the resin material.

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