WO2025253986A1 - Antiviral resin composition, masterbatch for synthetic resin molding, and viral infection–inhibiting molded body - Google Patents

Abstract

The present invention provides an antiviral resin composition that makes it possible to maintain excellent viral infection inhibition effects even after wiping with water. This antiviral resin composition includes magnesium oxide, an auxiliary agent, and a synthetic resin. The auxiliary agent includes a nonionic surfactant or polyoxyalkylene glycol and therefore has excellent water resistance. A synthetic resin molded body that includes this antiviral resin composition maintains excellent viral infection inhibition effects even after contact with water caused by cleaning by wiping with water or the like or contact with a human hand or the like.

Description

Antiviral resin composition, synthetic resin molding masterbatch, and virus infection-preventing molded article

The present invention relates to an antiviral resin composition, a masterbatch for synthetic resin molding, and a molded article that prevents viral infection.

In recent years, in addition to seasonal influenza virus outbreaks, the novel coronavirus (COVID-19) has become a global pandemic.

Furthermore, highly pathogenic avian influenza viruses have mutated and been confirmed to be infecting humans, and there are also concerns about the SARS virus, which has an extremely high mortality rate, so anxiety about viruses is only increasing.

To address these issues, Patent Document 1 discloses an antiviral material that contains a metal oxide powder and hydroxide, which enables the generation of hydroxyl radicals that inactivate viruses.

Patent Document 2 discloses an antiviral agent containing oxide and/or hydroxide powder.

Furthermore, synthetic resin molded products are used in a variety of applications today, and as a countermeasure against viruses, antiviral properties are imparted to synthetic resin molded products by incorporating antiviral agents into them.

WO2009/098786 WO2005/013695

However, when a synthetic resin molded product is produced by incorporating the antiviral agents described in Patent Documents 1 and 2 into a synthetic resin, the problem arises that when the surface of the synthetic resin molded product is brought into contact with water, such as by wiping with water, the antiviral properties (effectiveness in preventing viral infection) of the synthetic resin molded product are reduced due to its low water resistance.

The present invention provides an antiviral resin composition that maintains excellent viral infection-preventing effects even after wiping with water, as well as a synthetic resin molding masterbatch and a viral infection-preventing molded article that use the antiviral resin composition.

The antiviral resin composition of the present invention contains magnesium oxide, an auxiliary agent, and a synthetic resin, and the auxiliary agent contains a nonionic surfactant or polyoxyalkylene glycol.

The synthetic resin molding masterbatch of the present invention is characterized by containing the above-mentioned antiviral resin composition.

The viral infection-blocking molded article of the present invention is characterized by containing the above-mentioned antiviral resin composition.

The antiviral resin composition of the present invention contains magnesium oxide, the above-mentioned auxiliary agent, and a synthetic resin, and the antiviral resin composition has excellent water resistance. Therefore, a synthetic resin molded article containing the antiviral resin composition of the present invention maintains excellent virus infection prevention effect (hereinafter referred to as "water-resistant virus infection prevention effect") even after coming into contact with water due to cleaning such as wiping with water or contact with human hands.

The antiviral resin composition of the present invention contains magnesium oxide, an auxiliary agent, and a synthetic resin, and the auxiliary agent contains a nonionic surfactant or polyoxyalkylene glycol.

In the antiviral resin composition, the total content of magnesium oxide, the above-mentioned auxiliary agent, and synthetic resin is preferably 50% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, more preferably 90% by mass or more, more preferably 95% by mass or more, and more preferably 99% by mass or more.

[Magnesium oxide]
The antiviral resin composition contains magnesium oxide. The magnesium oxide may be used alone or in combination of two or more types.

Magnesium oxide improves the water-resistant viral infection prevention effect of the antiviral resin composition, so it is preferable to include at least one type of magnesium oxide selected from the group consisting of light-burned magnesium oxide, heavy-burned magnesium oxide, and electro-fused magnesium oxide, and it is preferable to include light-burned magnesium oxide or electro-fused magnesium oxide, and it is more preferable to include light-burned magnesium oxide.

The content of light-burned magnesium oxide in the magnesium oxide is preferably 50% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, more preferably 90% by mass or more, more preferably 95% by mass or more, more preferably 99% by mass or more, and more preferably 100% by mass.

The content of electrofused magnesium oxide in the magnesium oxide is preferably 50% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, more preferably 90% by mass or more, more preferably 95% by mass or more, more preferably 99% by mass or more, and more preferably 100% by mass.

The content of burnt magnesium oxide in the magnesium oxide is preferably 50% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, more preferably 90% by mass or more, more preferably 95% by mass or more, more preferably 99% by mass or more, and more preferably 100% by mass.

Lightly burned magnesium oxide is magnesium oxide obtained by burning a mineral whose main components are at least one of magnesium carbonate and magnesium hydroxide at 600 to 1000°C.

The MgO content in the light-burned magnesium oxide is preferably 80% by mass or more, more preferably 85% by mass or more, and even more preferably 90% by mass or more. The MgO content in the light-burned magnesium oxide is preferably 99.9% by mass or less. When the MgO content in the light-burned magnesium oxide is within the above range, the water-resistant viral infection prevention effect of the antiviral resin composition is improved.

The CaO content in the light-burned magnesium oxide is preferably 0 to 3 mass%, more preferably 0 to 2.5 mass%, more preferably 0 to 2 mass%, more preferably 0.01 to 2 mass%, and even more preferably 0.01 to 1 mass%. When the CaO content in the light-burned magnesium oxide is within the above range, the water-resistant viral infection prevention effect of the antiviral resin composition is improved. In the present invention, a content of compound A of 0 mass% means that compound A is not contained.

The _SiO2 content in the light-burned magnesium oxide is preferably 0 to 5 mass%, more preferably 0 to 3 mass%, and even more preferably 0 to 2 mass%. When the _SiO2 content in the light-burned magnesium oxide is within the above range, the water-resistant viral infection-preventing effect of the antiviral resin composition is improved.

The content of _Fe2O3 in the light-burned magnesium oxide is preferably 0 to 1 mass%, more preferably 0 to 0.5 mass%, more preferably 0 to 0.4 mass%, more preferably _0.0001 to 0.1 mass%, and more preferably 0.0005 to 0.05 mass%. When the content of _Fe2O3 in the light-burned magnesium _oxide is within the above range, the water-resistant viral infection prevention effect of the antiviral resin composition is improved.

The contents of MgO, CaO, _SiO2 , _{and Fe2O3} in magnesium oxide can be measured by the Fundamental Parameter (FP) method using an energy dispersive X-ray fluorescence analyzer. For example, an energy dispersive X-ray fluorescence analyzer commercially available from PHILIPS under the trade name "PW1404" can be used.

Burned magnesium oxide is magnesium oxide obtained by burning a mineral whose main components are at least one of magnesium carbonate and magnesium hydroxide at a temperature of 1500°C or higher.

Electrofused magnesium oxide is produced by electro-melting magnesium oxide or magnesium compounds such as magnesium hydroxide and magnesium carbonate to produce a molten and solidified magnesium oxide, which is then crushed as needed.

The MgO content in the electro-fused magnesium oxide is preferably 85% by mass or more, more preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably 96% by mass or more. The MgO content in the electro-fused magnesium oxide is preferably 99.9% by mass or less, and more preferably 99.0% by mass or less. When the MgO content in the electro-fused magnesium oxide is within the above range, the water-resistant viral infection prevention effect of the anti-viral resin composition is improved.

The CaO content in the electrofused magnesium oxide is preferably 0 to 3 mass%, more preferably 0.001 to 2.5 mass%, more preferably 0.002 to 2 mass%, more preferably 0.005 to 1.5 mass%, more preferably 0.01 to 1 mass%, and more preferably 0.05 to 0.8 mass%. When the CaO content in the electrofused magnesium oxide is within the above range, the water-resistant viral infection prevention effect of the antiviral resin composition is improved.

The _SiO2 content in the electro-fused magnesium oxide is preferably 0 to 5 mass%, more preferably 0.02 to 2 mass%, more preferably 0.03 to 1 mass%, and even more preferably 0.04 to 0.5 mass%. When the _SiO2 content in the electro-fused magnesium oxide is within the above range, the water-resistant viral infection prevention effect of the antiviral resin composition is improved.

The content of _Fe2O3 in the electrofused magnesium oxide is preferably 0 to 1 mass%, more preferably 0.01 to 0.5 mass%, more preferably 0.02 to 0.4 mass%, more preferably _0.025 to 0.3 mass%, and more preferably 0.03 to 0.1 mass%. When the content of _Fe2O3 in the electrofused magnesium _oxide is within the above range, the water-resistant viral infection prevention effect of the antiviral resin composition is improved.

The specific surface area of magnesium oxide is preferably 20 ^m2 /g or more, more preferably 22 ^m2 /g or more, more preferably 23 ^m2 /g or more, more preferably 25 ^m2 /g or more, and preferably 27 ^m2 /g or more. The specific surface area of magnesium oxide is preferably 100 ^m2 /g or less, more preferably 95 ^m2 /g or less, more preferably 90 ^m2 /g or less, and more preferably 85 ^m2 /g or less. When the specific surface area of magnesium oxide is within the above range, the magnesium oxide and the auxiliary agent described below interact appropriately, improving the water-resistant viral infection-preventing effect of the antiviral resin composition.

The specific surface area of magnesium oxide is the value measured using the BET method in accordance with ASTM D3037-93.

The D50 particle size of the magnesium oxide is preferably 0.1 μm or more, more preferably 0.2 μm or more, more preferably 0.3 μm or more, and more preferably 0.4 μm or more. The D50 particle size of the magnesium oxide is preferably 10 μm or less, more preferably 9 μm or less, more preferably 8 μm or less, more preferably 7 μm or less, preferably 6 μm or less, and more preferably 5 μm or less. When the D50 particle size of the magnesium oxide is 0.1 μm or more, aggregation of the antiviral resin composition is reduced and it can be incorporated uniformly into the substrate, improving the water-resistant virus infection-blocking effect of the virus infection-blocking molded product. When the D50 particle size of the magnesium oxide is 50 μm or less, the surface area of the antiviral resin composition increases, which tends to improve the water-resistant virus infection-blocking effect of the antiviral resin composition.

The D50 particle size of magnesium oxide is the particle size (50% cumulative particle size) at which the cumulative frequency (cumulative from smallest particles) in the volume-based particle size distribution measured by laser scattering method is 50%.

The content of magnesium oxide in the antiviral resin composition is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and more preferably 3 parts by mass or more, per 100 parts by mass of the total of magnesium oxide, auxiliary agents, and the synthetic resin described below. The content of magnesium oxide in the antiviral resin composition is preferably 10 parts by mass or less, more preferably 9 parts by mass or less, more preferably 8 parts by mass or less, and more preferably 7 parts by mass or less, per 100 parts by mass of the total of magnesium oxide, auxiliary agents, and the synthetic resin described below. When the content of magnesium oxide is 1 part by mass or more, the water-resistant viral infection prevention effect of the antiviral resin composition is improved. When the content of magnesium oxide is 10 parts by mass or less, the strength of the antiviral resin composition is more easily maintained, which is preferable.

[Auxiliary Agents]
The antiviral resin composition contains a nonionic surfactant or polyoxyalkylene glycol as an auxiliary agent. Although the reason for this has not been clearly elucidated, it is presumed that the antiviral resin composition contains the auxiliary agent, which reduces the removal of magnesium oxide by moisture or the reaction of magnesium oxide with moisture to form magnesium hydroxide, thereby imparting an excellent water-resistant viral infection prevention effect to the antiviral resin composition. The auxiliary agent may contain only one of a nonionic surfactant or a polyoxyalkylene glycol, or may contain both.

Furthermore, the nonionic surfactants and polyoxyalkylene glycols used as auxiliary agents do not contain functional groups that become anionic or cationic when dissolved in water. Because the nonionic surfactants and polyoxyalkylene glycols moderately adsorb moisture without inhibiting the mechanism by which magnesium oxide denatures viral proteins, it is presumed that the antiviral resin composition exhibits excellent water-resistant viral infection prevention effects.

In this way, the antiviral resin composition exhibits excellent water-resistant viral infection prevention effects due to the synergistic effect of the combination of magnesium oxide and the above-mentioned auxiliary agent.

Examples of polyoxyalkylene glycols include polyethylene glycol, polypropylene glycol, polybutylene glycol, and polyoxyethylene polyoxypropylene glycol. Polyethylene glycol is preferred because it provides excellent water-resistant viral infection prevention effects to the antiviral resin composition. Polyoxyalkylene glycols may be used alone or in combination of two or more types.

Nonionic surfactants are not particularly limited, and examples include polyoxyalkylene alkyl ethers, polyoxyethylene alkylphenyl ethers, fatty acid esters, polyoxyethylene distyrenated phenyl ethers, polyoxyethylene alkylamines, polyoxyethylene fatty acid amides, fatty acid alkanolamides, fatty alcohols, fatty acid alkylolamides, alkylalkanolamides, acetylene glycol, oxyethylene adducts of acetylene glycol, polyethylene glycol polypropylene glycol block copolymers, and the like. Nonionic surfactants may be used alone or in combination of two or more types.

Fatty acid esters are not particularly limited, and examples include polyalkylene glycol fatty acid esters (e.g., polyalkylene glycol mono-fatty acid esters such as polyethylene glycol monostearate and polypropylene glycol monostearate, and polyalkylene glycol di-fatty acid esters such as polyethylene glycol distearate and polypropylene glycol distearate), sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, glycol fatty acid esters (e.g., ethylene glycol fatty acid esters and propylene glycol fatty acid esters), glycerin fatty acid esters (e.g., saturated fatty acid monoglycerides, saturated fatty acid diglycerides, unsaturated fatty acid monoglycerides, unsaturated fatty acid diglycerides), polyoxyethylene glycerin fatty acid esters, polyglycerin fatty acid esters, and sucrose fatty acid esters.

Fatty acid esters are excellent in providing the antiviral resin composition with a water-resistant viral infection prevention effect, so sorbitan fatty acid esters (sorbitan saturated fatty acid esters are more preferred, and sorbitan monosaturated fatty acid esters are more preferred), glycerin fatty acid esters (fatty acid monoglycerides are preferred, and saturated fatty acid monoglycerides are more preferred), polyalkylene glycol fatty acid esters (polyalkylene glycol saturated fatty acid esters are more preferred, and polyalkylene glycol disaturated fatty acid esters are more preferred), glycol fatty acid esters (alkylene glycol saturated fatty acid esters are more preferred, and alkylene glycol monosaturated fatty acid esters are more preferred), and polyalkylene glycol fatty acid esters are more preferred.

In fatty acid esters, the total number of carbon atoms in the fatty acids used as raw materials is preferably 14 to 20, more preferably 15 to 19, and even more preferably 16 to 18, in order to provide an excellent water-resistant antiviral infection prevention effect for the antiviral resin composition.

Fatty acid esters are preferred as the raw material fatty acids, as they provide excellent water-resistant viral infection prevention effects for the antiviral resin composition.

Aliphatic alcohols include, but are not limited to, capryl alcohol (1-octanol), pelargonic alcohol (1-nonanol), capric alcohol (1-decanol), lauryl alcohol (1-dodecanol), myristyl alcohol (1-tetradecanol), cetyl alcohol (1-hexadecanol), palmitoleic alcohol (cis-9-hexadecan-1-ol), stearyl alcohol (1-octadecanol), isostearyl alcohol (16-methylheptadecan-1-ol), elaidyl alcohol (9E-octadecen-1-ol), cetostearyl alcohol (a mixture of cetearyl alcohol, cetyl alcohol, and stearyl alcohol), oleyl alcohol (cis-9-octadecen-1-ol), and linoleyl alcohol (9Z,12Z-octadecadien-1-ol).

The aliphatic alcohol preferably has a structure represented by R ¹ -OH. R ¹ is a monovalent aliphatic hydrocarbon group. The hydrogen atom of R ¹ may be substituted with another substituent. Aliphatic hydrocarbons refer to hydrocarbons that belong to compounds (aliphatic compounds) other than aromatic compounds that have aromaticity. Aliphatic hydrocarbons are a concept that includes chain aliphatic hydrocarbons in which carbon atoms are bonded in a row, branched chain aliphatic hydrocarbons with a branched structure, and alicyclic hydrocarbons in which carbon atoms are bonded in a ring. A monovalent aliphatic hydrocarbon group refers to a monovalent substituent resulting from abstracting one hydrogen atom from an aliphatic hydrocarbon.

Aliphatic alcohols have excellent water-resistant viral infection prevention effects in antiviral resin compositions, so the number of carbon atoms in the aliphatic alcohol is preferably 14 to 20, more preferably 15 to 19, and even more preferably 16 to 18.

The polyoxyalkylene alkyl ether is not particularly limited, and examples include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene oleyl cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, and polyoxyethylene polyoxypropylene lauryl ether; and polyoxypropylene alkyl ethers such as polyoxypropylene cetyl ether, polyoxypropylene isocetyl ether, polyoxypropylene stearyl ether, and polyoxypropylene oleyl ether.

Fatty acid alkanolamides are not particularly limited, but examples include coconut fatty acid alkanolamides such as lauric acid diethanolamide, coconut fatty acid dimethanolamide, coconut fatty acid diethanolamide, and coconut fatty acid dipropanolamide.

The nonionic surfactant preferably contains a fatty acid ester, a fatty alcohol, or an aliphatic compound having a polyoxyalkylene structure in the molecule, as this improves the water-resistant viral infection prevention effect of the antiviral resin composition.

In this specification, "fatty acid esters having a polyoxyalkylene structure" are treated as fatty acid esters. "fatty alcohols having a polyoxyalkylene structure" are treated as aliphatic alcohols. Therefore, "aliphatic compounds having a polyoxyalkylene structure within the molecule" do not have an ester structure, alcoholic hydroxyl group, or phenolic hydroxyl group within the molecule.

"Aliphatic compound" refers to compounds other than those having an aromatic ring structure. An aromatic ring structure is a structure in which carbon atoms are bonded in a ring and have aromatic properties. In other words, an aromatic ring structure is a ring structure that follows Hückel's rule and has (4n + 2) π electrons (n is a natural number). Examples of aromatic ring structures include a benzene ring structure and a naphthalene ring structure.

The content of fatty acid ester in the nonionic surfactant is preferably 50% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, more preferably 90% by mass or more, and more preferably 95% by mass or more.

The content of aliphatic alcohol in the nonionic surfactant is preferably 50% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, more preferably 90% by mass or more, and more preferably 95% by mass or more.

In the nonionic surfactant, the content of the aliphatic compound having a polyoxyalkylene structure in the molecule is preferably 50% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, more preferably 90% by mass or more, and more preferably 95% by mass or more.

The polyoxyalkylene structure means a repeating unit represented by the following general formula:
-(R ² -O)p-
(In the formula, ^R2 represents an alkylene group having 1 to 14 carbon atoms, and p represents the number of repeating units and is a natural number of 2 or more.)

In the present invention, an alkylene group is a divalent atomic group formed by removing two hydrogen atoms bonded to two different carbon atoms in an aliphatic saturated hydrocarbon, and includes both linear and branched atomic groups. Note that branched includes cases where one carbon (methyl group) is bonded as a side chain.

Examples of the alkylene group include a methylene group [ _-CH2- ], an ethylene group [ _-CH2 - _CH2- ], a propylene group [-CH( _CH3 ) _-CH2- ], a trimethylene group [ _-CH2 - _CH2 - _CH2- ], a butylene group, an amylene group [-( _CH2 ) _5- ], and a hexylene group, with an ethylene group and a propylene group being preferred, and an ethylene group being more preferred.

The fatty acid ester and/or fatty alcohol preferably contains a polyoxyalkylene structure in the molecule. When the fatty acid ester and/or fatty alcohol contains a polyoxyalkylene structure, the polyoxyalkylene structure more effectively controls moisture adsorption and release, making the magnesium oxide more effective at preventing water-resistant viral infections.

Furthermore, aliphatic nonionic surfactants that have a polyoxyalkylene structure within their molecules are more likely to segregate (bleed out) on the surface of synthetic resins. Therefore, even if the antiviral resin composition present on the surface of a synthetic resin molded product is removed by cleaning such as wiping with water or by contact with human hands, it can be more effectively segregated (bleed out) on the surface of the synthetic resin molded product, more reliably imparting excellent water-resistant viral infection prevention effects to the synthetic resin molded product.

The HLB value of the nonionic surfactant is preferably 15 or more, more preferably 16 or more, more preferably 17 or more, and even more preferably 18 or more. When the HLB value of the dispersant is 15 or more, the interaction between magnesium oxide and viruses can be improved, and the water-resistant viral infection-preventing effect of the antiviral resin composition can be improved. In addition, the antiviral resin composition can be more effectively bled out onto the surface of the synthetic resin molded article, and the excellent water-resistant viral infection-preventing effect can be more stably imparted to the synthetic resin molded article. The HLB value of the nonionic surfactant is a value calculated according to the Griffin method based on the following formula.
HLB value = 20 x sum of formula weights of hydrophilic parts / molecular weight

The melting point of the auxiliary agent is preferably 30°C or higher, more preferably 35°C or higher, and even more preferably 40°C or higher. The melting point of the auxiliary agent is preferably 80°C or lower, more preferably 75°C or lower, and even more preferably 70°C or lower. A melting point of the auxiliary agent of 30°C or higher is preferred because it improves the shape retention of the antiviral resin composition at room temperature. A melting point of the auxiliary agent of 80°C or lower is preferred because it melts during processing of the antiviral resin composition, allowing the compounds that make up the antiviral resin composition to mix uniformly. The melting point of the auxiliary agent is the value measured by differential scanning calorimetry in accordance with JIS K7121-1987.

The molecular weight of the auxiliary agent is preferably 200 or more, more preferably 250 or more. The molecular weight of the auxiliary agent is preferably 50,000 or less, more preferably 45,000 or less, more preferably 40,000 or less, more preferably 35,000 or less, more preferably 30,000 or less, and more preferably 25,000 or less. When the molecular weight of the auxiliary agent is within the above range, the water-resistant viral infection inhibitory effect of the virus infection inhibitor is improved. Note that when the auxiliary agent is an oligomer or polymer, the molecular weight of the auxiliary agent means the weight-average molecular weight.

In the present invention, the weight-average molecular weight of oligomers and polymers is a polystyrene-equivalent value measured by GPC (gel permeation chromatography).

For example, the measurement can be performed using the following measurement device and under the following measurement conditions.
Gel permeation chromatograph: Waters Corporation, product name "2690 Separations Model"
Column: Showa Denko K.K. product name "GPCKF-806L"
Detector: differential refractometer Sample flow rate: 1 mL/min
Column temperature: 40°C
Eluent: THF

The content of the auxiliary agent in the antiviral resin composition is preferably 0.1 parts by mass or more, more preferably 0.2 parts by mass or more, more preferably 0.3 parts by mass or more, more preferably 0.4 parts by mass or more, more preferably 0.5 parts by mass or more, more preferably 0.6 parts by mass or more, and more preferably 0.7 parts by mass or more, per 100 parts by mass of the total of the magnesium oxide, auxiliary agent, and synthetic resin described below. The content of the auxiliary agent in the antiviral resin composition is preferably 1.8 parts by mass or less, more preferably 1.7 parts by mass or less, more preferably 1.6 parts by mass or less, more preferably 1.5 parts by mass or less, and more preferably 1.4 parts by mass or less, per 100 parts by mass of the total of the magnesium oxide, auxiliary agent, and synthetic resin described below. When the content of the auxiliary agent is 0.1 parts by mass or more, the water-resistant viral infection prevention effect of the antiviral resin composition is improved. When the content of the auxiliary agent is 1.8 parts by mass or less, the strength of the antiviral resin composition is more easily maintained.

The mass ratio of the auxiliary agent content to the magnesium oxide content (auxiliary agent content/magnesium oxide content) is preferably 0.1 or more, more preferably 0.12 or more, more preferably 0.15 or more, more preferably 0.18 or more, and more preferably 0.19 or more. The mass ratio of the auxiliary agent content to the magnesium oxide content (auxiliary agent content/magnesium oxide content) is preferably 2.2 or less, more preferably 2.0 or less, more preferably 1.5 or less, more preferably 1.3 or less, more preferably 1.0 or less, more preferably 0.8 or less, more preferably 0.6 or less, and more preferably 0.4 or less. When the mass ratio of the auxiliary agent content to the magnesium oxide content (auxiliary agent content/magnesium oxide content) is 0.1 or more, it is possible to reduce the inactivation of magnesium oxide due to moisture and reduce the outflow of the antiviral resin composition due to water, as well as improve the inactivation of viruses by magnesium oxide. When the mass ratio of the auxiliary agent content to the magnesium oxide content (auxiliary agent content/magnesium oxide content) is 2.2 or less, the water-resistant viral infection prevention effect of the antiviral resin composition can be improved.

[Synthetic resin]
The antiviral resin composition contains a synthetic resin. The synthetic resin is not particularly limited, and examples thereof include thermoplastic resins (e.g., polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinyl acetate, polyurethane, Teflon (registered trademark), acrylonitrile butadiene styrene resin, acrylonitrile styrene resin, acrylic resin, polyvinyl alcohol, polyamide, polyacetal, polycarbonate, modified polyphenylene ether, polyester, polyethylene terephthalate, polybutylene terephthalate, cyclic polyolefin, polyphenylene sulfide, polytetrafluoroethylene, polysulfone, polyethersulfone, polyarylate, polyetheretherketone, thermoplastic polyimide, polyamideimide, etc.), and thermosetting resins (e.g., phenolic resin, epoxy resin, melamine resin, urea resin, unsaturated polyester resin, alkyd resin, silicone resin, polyurethane, thermosetting polyimide, etc.). The synthetic resins may be used alone or in combination.

The content of synthetic resin in the antiviral resin composition is preferably 88.2 parts by mass or more, more preferably 89.7 parts by mass or more, and even more preferably 90.4 parts by mass or more, per 100 parts by mass of the total of magnesium oxide, auxiliary agent, and synthetic resin. The content of synthetic resin in the antiviral resin composition is preferably 98.9 parts by mass or less, more preferably 97.8 parts by mass or less, and even more preferably 96.7 parts by mass or less, per 100 parts by mass of the total of magnesium oxide, auxiliary agent, and synthetic resin.

[Antioxidants]
The antiviral resin composition preferably contains an antioxidant, which allows the antiviral resin composition to maintain its excellent viral infection-inhibiting effect even after being exposed to irradiated light such as sunlight or light emitted from lighting (hereinafter, sometimes simply referred to as "irradiated light").

The mechanism by which an antiviral resin composition containing an antioxidant can maintain its excellent viral infection-inhibiting effect even after exposure to light has not been elucidated, but it is presumed to be due to the following mechanism.

The antiviral resin composition is heated during molding processes such as those used to produce virus infection-blocking molded articles. This heating oxidizes the synthetic resin in the antiviral resin composition, generating carboxyl groups in the molecular chains of the synthetic resin. Molecular chains with carboxyl groups are more susceptible to severing by irradiated light at the locations where the carboxyl groups are generated.

Furthermore, when an antiviral resin composition is used, it is usually exposed to light, which also causes the molecular chains of the synthetic resin to be severable over time.

When the molecular chains of the synthetic resin are cut and the chain length of the synthetic resin shortens, it is presumed that the magnesium oxide in the antiviral resin composition becomes more likely to be coated with the synthetic resin with a short chain length, reducing the antiviral resin composition's effectiveness in preventing viral infection.

Furthermore, the carboxyl groups formed in the molecular chains of synthetic resins may inhibit the effectiveness of magnesium oxide in preventing viral infection.

By adding an antioxidant to the antiviral resin composition, it is possible to reduce the generation of carboxyl groups due to thermal degradation of the synthetic resin when the antiviral resin composition is heated, such as during the molding process. This reduces the inhibition of the viral infection-preventing effect of magnesium oxide by carboxyl groups.

Furthermore, it is possible to reduce the severing of the molecular chains of the synthetic resin due to the irradiated light. Therefore, by including an antioxidant in the antiviral resin composition, it is possible to reduce the coating of magnesium oxide with synthetic resin, and the antiviral resin composition can maintain its excellent viral infection prevention effect even after being exposed to irradiated light.

The antioxidant is not particularly limited and may be a primary antioxidant or a secondary antioxidant, with secondary antioxidants being preferred. The antioxidants may be used alone or in combination of two or more types.

The content of the primary antioxidant in the antioxidant is preferably 50% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, more preferably 90% by mass or more, more preferably 95% by mass or more, more preferably 99% by mass or more, and more preferably 100% by mass.

The content of the secondary antioxidant in the antioxidant is preferably 50% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, more preferably 90% by mass or more, more preferably 95% by mass or more, more preferably 99% by mass or more, and more preferably 100% by mass.

Primary antioxidants are stabilizers that capture radicals generated by heat or light and stop radical reactions. There are no particular limitations on primary antioxidants, but examples include phenolic antioxidants.

Phenol-based antioxidants include, for example, 2,6-di-t-butyl-4-methylphenol, n-octadecyl-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate, tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxymethyl]methane, tris[N-(3,5-di-t-butyl-4-hydroxybenzyl)]isocyanurate, butylidene-1,1-bis(2- Examples include 3,9-bis{2-[3(3-t-butyl-4-hydroxy-5-methylphenyl)propionate], triethylene glycol bis[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionate], and 3,9-bis{2-[3(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5.5]undecane, which may be used alone or in combination of two or more.

Secondary antioxidants prevent autoxidation by ionizing hydroperoxide (ROOH), an intermediate in the autoxidation degradation of polyolefin resins caused by heat or light. There are no particular limitations on the secondary antioxidant, and examples include phosphorus-based antioxidants and sulfur-based antioxidants, with phosphorus-based antioxidants being preferred.

Examples of phosphorus-based antioxidants include tridecyl phosphite, tris(tridecyl)phosphite, tristearyl phosphite, triphenyl phosphite, trinonylphenyl phosphite, bis(tridecyl)pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, bis(decyl)pentaerythritol diphosphite, tris(2,4-di-t-butylphenyl)phosphite, 3,9-bis(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, bis(2,4-di-t-butyl-6-methyl) Examples of suitable phosphate compounds include 2,2'-methylenebis(4,6-di-t-butylphenyl)ethyl ester phosphorous acid, 2,2'-methylenebis(4,6-di-t-butyl-1-phenyloxy)(2-ethylhexyloxy)phosphorus, 2,2'-methylenebis(4,6-di-t-butylphenyl)2-ethylhexyl phosphite, diethyl(3,5-di-t-butyl-4-hydroxybenzyl)phosphonate, and stearyl acid phosphate zinc salt, with tris(2,4-di-t-butylphenyl)phosphite and 3,9-bis(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane being preferred.

Examples of sulfur-based antioxidants include dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, and pentaerythritol tetrakis(3-laurylthiopropionate).

The content of the antioxidant in the antiviral resin composition is preferably 0.01 parts by mass or more, more preferably 0.04 parts by mass or more, and even more preferably 0.05 parts by mass or more, per 100 parts by mass of the total of the magnesium oxide, auxiliary agent, synthetic resin, and antioxidant. The content of the antioxidant in the antiviral resin composition is preferably 5 parts by mass or less, more preferably 1 part by mass or less, and even more preferably 0.5 parts by mass or less, per 100 parts by mass of the total of the magnesium oxide, auxiliary agent, synthetic resin, and antioxidant. When the content of the antioxidant is 0.01 parts by mass or more, the antiviral resin composition can maintain its excellent viral infection-preventing effect even after exposure to light. When the content of the antioxidant is 5 parts by mass or less, the physical properties of the antiviral resin composition are less likely to be impaired, which is preferable.

In the antiviral resin composition, the total content of magnesium oxide, the above-mentioned auxiliary agent, synthetic resin, and antioxidant is preferably 50% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, more preferably 90% by mass or more, more preferably 95% by mass or more, more preferably 99% by mass or more, and more preferably 100% by mass.

The antiviral resin composition may contain additives such as plasticizers, curing agents, extenders, fillers, reinforcing materials, colorants, flame retardants, flame retardant aids, fluorescent brighteners, impact modifiers, anti-fogging agents, flow improvers, plasticizers, and light stabilizers, within limits that do not impair its physical properties.

[Antiviral resin composition]
The antiviral resin composition contains magnesium oxide, an auxiliary agent, and a synthetic resin. The method for producing the antiviral resin composition is not particularly limited, and the antiviral resin composition can be produced by mixing the magnesium oxide, the auxiliary agent, and the synthetic resin with compounds such as an antioxidant that are added as needed in a general manner using an extruder or the like.

The term "viral infection inhibitory effect" refers to the effect of eliminating or reducing the infectivity of viruses to cells, or preventing them from multiplying within the cells even if they infect. Examples of methods for confirming the infectivity of viruses include ISO 18184 and JIS L1922 for textile products, and ISO 21702 for plastics and non-porous surface products other than textiles. The Society of International Antimicrobial Association (SIAA) certifies the antiviral finish mark to products that meet the safety and antiviral effectiveness standards for antiviral processing agents. The standard for antiviral effectiveness is a difference (antiviral activity value) of 2.0 or more between the common logarithm of the viral infectivity titer of a blank product (product without antiviral processing agent) and the common logarithm of the viral infectivity titer of a processed product (product with antiviral processing agent added) in an ISO 21702 evaluation. An antiviral resin composition may be effective as long as its antiviral activity value is 2.0 or more for any virus.

Other methods include the plaque assay and hemagglutination unit (HAU) assay, as described in "Medical and Pharmaceutical Virology" (first published in April 1990).

The viral infection-preventing effect of an antiviral resin composition can be measured, for example, as follows: The antiviral resin composition is press-molded to produce a sheet-like synthetic resin molded product with an average thickness of 1 mm. The surface of the obtained synthetic resin molded product is wiped with a flat square nonwoven fabric measuring 10 cm on a side by moving the nonwoven fabric back and forth 10 times, and this synthetic resin molded product is used as the test specimen.

The obtained test specimen is subjected to an antiviral test (test time: 24 hours) in accordance with ISO 21702. For the virus suspension 10 minutes after the reaction (start of the test), the virus infectivity titer (common logarithm value) (PFU/cm ² ) of the test specimen is calculated by the plaque method.

A blank reference body was prepared in the same manner as above, except that a synthetic resin molded body was prepared by press molding using only synthetic resin, and the virus infectivity titer (common logarithm) (PFU/ ^cm2 ) was calculated based on this blank reference body in the same manner as above.

The antiviral activity value is calculated by subtracting the viral infectivity of the test specimen from the viral infectivity of the blank reference specimen.

The antiviral resin composition has the effect of inhibiting viral infections against various viruses, and exhibits excellent viral infection-inhibiting effects against both enveloped and non-enveloped viruses.

Examples of enveloped viruses include influenza viruses (e.g., types A and B), rubella viruses, Ebola viruses, coronaviruses [e.g., SARS virus, novel coronavirus (SARS-CoV-2)], measles viruses, varicella-zoster viruses, herpes simplex viruses, mumps viruses, arboviruses, respiratory syncytial viruses, hepatitis viruses (e.g., hepatitis B virus, hepatitis C virus, etc.), yellow fever viruses, AIDS viruses, rabies viruses, hantaviruses, dengue viruses, Nipah viruses, and lyssaviruses.

Examples of non-enveloped viruses include adenovirus, norovirus, rotavirus, human papillomavirus, enterovirus, coxsackievirus, human parvovirus, encephalomyocarditis virus, poliovirus, and rhinovirus.

The antiviral resin composition can be molded into the desired shape using a general-purpose synthetic resin molding method to obtain a virus infection-preventing molded article that has the effect of preventing virus infection. Examples of general-purpose synthetic resin molding methods include extrusion molding, injection molding, and blow molding.

There are no particular restrictions on the shape of the virus infection-preventing molded article, and it can be selected appropriately depending on the application and purpose of the virus infection-preventing molded article. Examples of shapes of the virus infection-preventing molded article include plate-like, plate-like, rod-like, sheet-like, film-like, cylindrical, ring-like, circular, elliptical, polygonal, irregularly shaped, hollow, frame-like, box-like, panel-like, and other shapes suited to various applications.

Applications of virus infection-blocking molded articles include, for example, structural component parts, portable electronic device components, vehicle components, medical device components, electronic component housings, and food and pharmaceutical containers.

The resulting virus infection-blocking molded article has excellent virus infection-blocking effects due to the antiviral resin composition. The antiviral resin composition contained in the virus infection-blocking molded article exhibits excellent water-resistant virus infection-blocking effects, and can maintain its excellent virus infection-blocking effects despite moisture from cleaning tasks such as wiping with water, contact with human hands, food and beverages, etc.

The antiviral resin composition may be used as a synthetic resin molding masterbatch, and the synthetic resin molding masterbatch may be mixed with the synthetic resin raw material to produce a virus infection-blocking molded article using a general-purpose synthetic resin molding method. The synthetic resin used in the synthetic resin molding masterbatch may be any of the synthetic resins exemplified above. Only one type of synthetic resin may be used, or two or more types may be used in combination.

The synthetic resin molding masterbatch is preferably in the form of resin pellets, as they have excellent moldability. By melting and molding the resin pellets, a virus infection-preventing molded product with excellent virus infection-preventing properties can be obtained.

The shape of the resin pellets is not particularly limited, and examples include spherical, cylindrical, and prismatic shapes. From the perspective of pellet shape stability, a cylindrical shape is preferred. The maximum length dimension of the resin pellets is preferably 1 mm or more, more preferably 3 mm or more. The maximum length dimension of the resin pellets is preferably 10 mm or less, more preferably 7 mm or less.

The synthetic resin molding masterbatch can be used by mixing it with other resin materials. The other resin materials may be in the form of resin pellets. By mixing the synthetic resin molding masterbatch with the other resin materials to obtain a mixed resin material, and then molding the mixed resin material, a virus infection-preventing molded article with excellent virus infection-preventing properties can be obtained.

The content of the antiviral resin composition in 100% by mass of the synthetic resin molding masterbatch is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more. The content of the antiviral resin composition in the synthetic resin molding masterbatch is preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less.

The content of magnesium oxide constituting the antiviral resin composition in 100% by mass of the masterbatch for synthetic resin molding is preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 50% by mass or more. The content of magnesium oxide constituting the antiviral resin composition in 100% by mass of the masterbatch for synthetic resin molding is preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less.

The content of the auxiliary agent constituting the antiviral resin composition in 100% by mass of the synthetic resin molding masterbatch is preferably 4% by mass or more, more preferably 6% by mass or more, and even more preferably 10% by mass or more. The content of magnesium oxide constituting the antiviral resin composition in 100% by mass of the synthetic resin molding masterbatch is preferably 16% by mass or less, more preferably 14% by mass or less, and even more preferably 12% by mass or less.

The present invention will be explained in more detail below using examples, but the present invention is not limited to these. Specific numerical values such as blending ratios (content ratios), physical property values, and parameters used in the following description can be replaced with the upper limit values (numeric values defined as "equal to or less than") or lower limit values (numeric values defined as "equal to or greater than") of the corresponding blending ratios (content ratios), physical property values, parameters, etc. described in the "Description of Embodiments."

The compounds used in the production of the antiviral resin compositions of the Examples and Comparative Examples are shown below.
[Magnesium oxide]
Light-burned magnesium oxide 1 (manufactured by Kyowa Chemical Industry Co., Ltd., trade name "Kyowamag 30"; MgO: 98% by mass, CaO: 0.63% by mass, and Fe ₂ O ₃ : 0.018% by mass)
Light-burned magnesium oxide 2 (manufactured by Kyowa Chemical Industry Co., Ltd. _, trade name "Kyowamag MF30", MgO: 99.7% by mass, CaO: 0.06% by mass, and _Fe2O3 : 0.0012% by mass)
Light-burned magnesium oxide 3 (manufactured by Kyowa Chemical Industry Co., Ltd., trade name "Kyowamag 150", MgO: 98% by mass, CaO: 0.78% by mass, and Fe ₂ O ₃ : 0.018% by mass)
Light-burned magnesium oxide 4 (manufactured by Kyowa Chemical Industry Co., Ltd. _, trade name "Kyowamag MF150", MgO: 99.6 mass%, CaO: 0.06 mass%, and _Fe2O3 : 0.0012 mass%)
Light-burned magnesium oxide 5 (manufactured by Tateho Chemical Co., Ltd., product name "TATEHOMAG 700", MgO: 99.2 mass%, CaO: 0.42 mass%, SiO ₂ : 0.16 mass%, Fe ₂ O ₃ : 0.03 mass%)
Light-burned magnesium oxide 6 (manufactured by Tateho Chemical Co., Ltd., product name "TATEHOMAG 500", MgO: 99 mass%, CaO: 0.42 mass%, SiO ₂ : 0.11 mass%, Fe ₂ O ₃ : 0.04 mass%)
Light-burned magnesium oxide 7 (manufactured by Tateho Chemical Co., Ltd., product name "TATEHOMAG H-10", MgO: 98.9 mass%, CaO: 0.4 mass%, SiO ₂ : 0.1 mass%, Fe ₂ O ₃ : 0.04 mass%)
Light-burned magnesium oxide 8 (manufactured by Ube Material Industries, Ltd., product name "UC-95HT"), MgO: 97.9% by mass, CaO: 0.54% by mass, SiO ₂ : 0.06% by mass, Fe ₂ O ₃ : 0.03% by mass)

[Auxiliary Agents]
- Sorbitan monostearate (Kao Corporation, product name "Rheodol SP-S10V")
Saturated fatty acid monoglyceride 1 (Kao Corporation, trade name "Excel VS-95", palmitic acid monoglyceride: 35 to 45% by mass, stearic acid monoglyceride: 50 to 60% by mass)
Saturated fatty acid monoglyceride 2 (manufactured by Kao Corporation, trade name "Excel P-40S", palmitic acid monoglyceride: 30 to 40% by mass, stearic acid monoglyceride: 50 to 60% by mass)
- Polyethylene glycol distearate (Kao Corporation, product name "Emanon 3299VB")
Propylene glycol monostearate (Riken Vitamin Co., Ltd., product name "Rikemal PS-100")
Cetostearyl alcohol (Kao Corporation, product name "Kalcol 6850")
Polyethylene glycol 1 (manufactured by NOF Corporation, trade name "PEG #4000P")
Polyethylene glycol 2 (manufactured by NOF Corporation, trade name "PEG #6000")
Polyethylene glycol 3 (manufactured by NOF Corporation, trade name "PEG #11000")
Polyethylene glycol 4 (manufactured by NOF Corporation, trade name "PEG #20000")

[Synthetic resin]
・Polypropylene (PP)

[Antioxidants]
Antioxidant 1 [tris(2,4-di-t-butylphenyl)phosphite, product name "Irgafos 168" manufactured by BASF Japan Ltd.]
Antioxidant 2 [3,9-bis(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, manufactured by ADEKA Corporation under the trade name "ADEKA STAB PEP-8"]

The specific surface area and D50 particle size of the magnesium oxide were measured as described above, and the results are shown in Table 1. The HLB value, molecular weight, and melting point of the auxiliary agent were measured as described above, and the results are shown in Table 1.

(Examples 1 to 17 and Comparative Examples 1 to 8)
Antiviral resin compositions were prepared by heating to 220°C and uniformly mixing the types and amounts of magnesium oxide, auxiliary agent, and synthetic resin shown in Table 1. In the antiviral resin composition, the contents of magnesium oxide, auxiliary agent, and synthetic resin are shown in the "Content (parts by mass)" column as "magnesium oxide content/auxiliary agent content/synthetic resin content."

(Examples 18 and 19)
Antiviral resin compositions were prepared by heating to 220°C and uniformly mixing the types and predetermined amounts of magnesium oxide, auxiliary agent, synthetic resin, and antioxidant shown in Table 3. In the antiviral resin composition, the contents of magnesium oxide, auxiliary agent, synthetic resin, and antioxidant are shown in the "Contents (parts by mass)" column in the following format: "Magnesium oxide content/auxiliary agent content/synthetic resin content/antioxidant content."

The antiviral activity values of the antiviral resin compositions obtained in the Examples and Comparative Examples were measured as follows, initially and after the water resistance test, and the results are shown in the "Initial" and "After the water resistance test" columns of "Antiviral activity value" in Tables 2 and 4, respectively.

For the antiviral resin compositions obtained in Examples 7, 18, and 19, the antiviral activity values after the light resistance test were measured as described below, and the results are shown in the "After light resistance test" column of "Antiviral activity value" in Table 4.

(Initial antiviral activity value)
The antiviral resin composition was press-molded to produce a sheet-like synthetic resin molded product with an average thickness of 1 mm. The surface of the obtained synthetic resin molded product was wiped with a flat square nonwoven fabric with sides of 10 cm by moving the nonwoven fabric back and forth 10 times, and this synthetic resin molded product was used as a test specimen.

The obtained test specimens were subjected to an antiviral test against feline calicivirus (test time: 24 hours) in accordance with ISO 21702. For the virus suspension 10 minutes after the reaction (start of the test), the virus infectivity titer (common logarithm) (PFU/ ^cm2 ) of the test specimens was calculated by the plaque method.

A blank reference body was prepared in the same manner as above, except that a synthetic resin molded body was produced by press molding using only synthetic resin, and the virus infectivity titer (common logarithm) (PFU/ ^cm2 ) was calculated based on this blank reference body in the same manner as above.

The initial antiviral activity value was calculated by subtracting the viral infectivity of the test specimen from the viral infectivity of the blank reference specimen.

(Antiviral activity value after water resistance test)
The antiviral resin composition was press-molded to produce a sheet-like synthetic resin molded product with an average thickness of 1 mm. The surface of the obtained synthetic resin molded product was wiped with a flat square nonwoven fabric with sides of 10 cm, moving the nonwoven fabric back and forth 10 times.

A water resistance test was conducted on the synthetic resin molded product in accordance with the water resistance test for water resistance category 1 specified by SIAA. Except for the fact that the water adhering to the surface of the synthetic resin molded product after the water resistance test was removed with a cloth to prepare the test specimen, the antiviral test was conducted in the same manner as for the initial antiviral activity value, and the antiviral activity value after the water resistance test was calculated.

(Antiviral activity value after light resistance test)
The antiviral resin composition was press-molded to produce a sheet-like synthetic resin molded product with an average thickness of 1 mm. The surface of the obtained synthetic resin molded product was wiped with a flat square nonwoven fabric with sides of 10 cm, moving the nonwoven fabric back and forth 10 times.

An antiviral test was performed in the same manner as for the initial antiviral activity value, except that a test specimen was prepared by irradiating the synthetic resin molded article with ^light at a wavelength of 365 nm using a xenon lamp for 10 hours so that the irradiation intensity was 60 W/m2, and the antiviral activity value after the light resistance test was calculated.

The antiviral resin composition of the present invention has excellent water resistance. The antiviral resin composition of the present invention can be used to produce a virus infection-inhibiting molded article that maintains its excellent virus infection-inhibiting effect even after contact with water (hereinafter referred to as "water-resistant virus infection-inhibiting effect").

CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority based on Japanese Patent Application No. 2024-092634, filed on June 6, 2024, the disclosure of which is incorporated herein by reference in its entirety.

Claims (9)

An antiviral resin composition comprising magnesium oxide, an auxiliary agent, and a synthetic resin, wherein the auxiliary agent comprises a nonionic surfactant or polyoxyalkylene glycol. The antiviral resin composition according to claim 1, characterized in that the HLB value of the auxiliary agent is 15 or more. The antiviral resin composition according to claim 1 or 2, characterized in that the nonionic surfactant contains a fatty acid ester, an aliphatic alcohol, or an aliphatic compound having a polyoxyalkylene structure in the molecule. 3. The antiviral resin composition according to claim 1, wherein the magnesium oxide has a specific surface area of 20 to 100 m ² /g. The antiviral resin composition according to claim 1 or 2, characterized in that the magnesium oxide has a D50 particle size of 10 μm or less. The antiviral resin composition according to claim 1 or 2, characterized in that the mass ratio of the content of the auxiliary agent to the content of the magnesium oxide (content of the auxiliary agent/content of the magnesium oxide) is 0.1 to 2.2. The antiviral resin composition according to claim 1 or 2, further comprising an antioxidant. A masterbatch for synthetic resin molding, comprising the antiviral resin composition according to claim 1 or 2. A viral infection-blocking molded article containing the antiviral resin composition of claim 1 or claim 2.