WO2023100967A1

WO2023100967A1 - Antiviral composition and molded product thereof

Info

Publication number: WO2023100967A1
Application number: PCT/JP2022/044328
Authority: WO
Inventors: 優衣羽室; 幸広伊倉; 康雄中島; 健一須山; 優衣大城戸; ノルザフリザ新田; 宝生瀧本; 英道藤原
Original assignee: 古河電気工業株式会社
Priority date: 2021-12-03
Filing date: 2022-12-01
Publication date: 2023-06-08
Also published as: JPWO2023100967A1; JP7394266B2

Abstract

Provided are a composition and a molded product having sufficiently high antibacterial properties and also having antiviral properties.　The provided antiviral composition contains: a base material containing a polyolefin resin; dispersed fibers composed of an organic material, particularly an organic material having water absorption properties; and dispersed particles composed of a metal material and/or an insoluble compound thereof, particularly a metal material and/or an insoluble compound thereof that exhibits an antiviral function in the presence of water. The provided molded product is composed of the aforementioned antiviral composition.

Description

Antiviral composition and molded product thereof

The present invention relates to an antiviral composition and a molded product thereof.

In recent years, due to the growing interest in environmental hygiene and the emergence of new infectious diseases, various antibacterial materials, antiviral materials, and antibacterial and antiviral products using them have been actively developed. . Among such materials, polymeric materials are useful as antibacterial and antiviral materials because they have high strength, excellent corrosion resistance, etc., and can be molded into desired shapes. For example, a resin composition containing an antibacterial agent or an antiviral agent, particularly a polyolefin resin composition, is lightweight, has both strength and flexibility, is excellent in hydrolysis resistance, etc., and is easy to mold. products are proposed.

As antibacterial agents, in addition to general organic antibacterial agents, inorganic antibacterial agents such as metals and their compounds are also frequently used. It has long been known that metal ions have an antibacterial effect, and inorganic antibacterial agents using these ions are less likely to volatilize or decompose than organic antibacterial agents that have functional groups such as phenols and halogens. Therefore, it is not only highly safe, but also has properties such as long-lasting antibacterial action and excellent heat resistance. From the advantage of such an inorganic antibacterial agent, for example, by adding metal oxide particles to the thermoplastic resin fibers constituting the nonwoven fabric and uniformly finely dispersing them, an antibacterial nonwoven fabric with high antibacterial performance (see Patent Document 1) ) and a plastic product containing an antibacterial agent obtained by incorporating a metal salt of an antibacterial agent into the outer surface of the plastic product (see Patent Document 2).

JP 2021-116483 A Japanese Patent Publication No. 2007-518704

As proposed in Patent Document 1 and Patent Document 2 above, adding an inorganic or organic antibacterial agent can impart a certain degree of antibacterial performance, but it is effective against viruses such as new infectious diseases. In the current situation where the needs for articles are increasing, no investigation has been made on antiviral properties.

Therefore, the object of the present invention is to provide a composition and molded article that not only have sufficiently high antibacterial properties, but also have excellent antiviral properties.

The present inventors have made intensive studies to achieve the above object, and as a result, dispersed particles made of a metallic material, particularly a metallic material that exhibits an antiviral function in the presence of water and/or an insoluble compound thereof, The present invention has been completed based on the discovery that high antibacterial performance and antiviral performance can be imparted to polyolefin resins when used in combination with organic materials, particularly dispersion fibers made of organic materials having water absorption properties. rice field.

In order to achieve the above object, the gist and configuration of the present invention are as follows.
[1] An antiviral composition comprising a base material containing a polyolefin resin, dispersed fibers made of an organic material, and dispersed particles made of a metal material and/or an insoluble compound thereof.
[2] The antiviral composition according to [1] above, wherein the organic material has water absorption properties, and the metallic material exhibits an antiviral function in the presence of water. thing.
[3] The above [1] or [2], wherein the base material, the dispersed fibers, and the dispersed particles are present in a mass percentage range of 40 to 80%: 5 to 55%: 1 to 25%. The antiviral composition according to .
[4] The above [1], [2], or [ 3], the antiviral composition.
[5] Any one of [1] to [4] above, wherein the dispersed fibers are one or more fibers selected from the group consisting of cellulose fibers, regenerated cellulose fibers, and polyester fibers. Antiviral composition as described.
[6] The antiviral composition of [5] above, wherein the dispersed fibers are cellulose fibers.
[7] The antiviral composition according to [6] above, wherein the cellulose fibers have an average fiber length of 10 to 3000 μm and an average fiber diameter of 1 to 50 μm.
[8] The above [1] to wherein the dispersed particles contain one or more metals and/or insoluble compounds thereof selected from the group consisting of copper, silver, zinc, nickel, aluminum, palladium, tin and iron. [7] The antiviral composition according to any one of [7].
[9] A molded article comprising the antiviral composition according to any one of [1] to [8] above.

In the description of the present invention, "~" is used to mean including the numerical values before and after it as lower and upper limits.

According to the present invention, it has become possible to provide a composition having not only sufficiently high antibacterial properties but also excellent antiviral properties, and a molded article thereof. Since the antiviral composition of the present invention uses a polyolefin resin as a base material, it is lightweight, yet has high strength and flexibility, and has excellent physical properties such as hydrolysis resistance. It has the advantage that it can be molded into any shape. Since the antiviral composition of the present invention also contains a metal-based material as an antibacterial and antiviral agent, it is excellent in durability of antibacterial action and antiviral action and heat resistance.

FIG. 1 is a plan view schematically showing an antiviral composition according to one embodiment of the present invention, showing the dispersed state of dispersed fibers and dispersed particles present in a base material. FIG. 4 is a cross-sectional view schematically showing a molded article of another embodiment of the present invention, showing the dispersed state of dispersed fibers and dispersed particles present in a base material. FIG. 2 is an electron micrograph of the surface of a pressed sheet specimen of Example 2 according to the present invention; FIG. 2 is an electron micrograph of a cross-section of a pressed sheet specimen of Example 2 according to the present invention; 3 is an electron micrograph of the surface of the pressed sheet test piece of Comparative Example 2. FIG. 10 is an electron micrograph of the surface of the pressed sheet test piece of Comparative Example 3. FIG.

The antiviral composition of the present invention will be described in detail below based on embodiments, but the present invention is not limited to these embodiments.

[Antiviral composition]
The antiviral composition of the present invention comprises a base material containing a polyolefin resin, dispersed fibers made of an organic material, and dispersed particles made of a metal material and/or an insoluble compound thereof. The antiviral composition of the present invention particularly comprises a base material containing a polyolefin resin, dispersed fibers made of a water-absorbing organic material, and a metal material that exhibits an antiviral function in the presence of water and/or its insolubility. and dispersed particles of the compound.

FIG. 1 is a plan view schematically showing an antiviral composition according to one embodiment of the present invention, showing the dispersed state of dispersed fibers and dispersed particles present in a base material. FIG. 2 is a cross-sectional view schematically showing a molded article according to another embodiment of the present invention, showing the dispersed state of dispersed fibers and dispersed particles present in a base material. As shown in the embodiments of FIGS. 1 and 2, in the antiviral composition 1 of the present invention, the dispersed fibers 3 and the dispersed particles 4 in the base material 2 containing a polyolefin resin are at least partially are preferably exposed from the base material 2 . Also in the molded body 11 of the present invention, the dispersed fibers 13 and the dispersed particles 14 in the base material 12 preferably exist in a state in which at least part of each is exposed on the surface of the molded body 11 .

The fact that part of the dispersed fibers 13 and dispersed particles 14 are exposed on the surface is also demonstrated in Examples described later (Figs. ). That is, in a preferred embodiment of the present invention, at least part of the dispersed fibers and dispersed particles in the base material is in direct contact with the outside of the antiviral composition 1 and molded article 11 . By slicing the compact or subjecting it to surface blasting, the exposed state described above can be more easily achieved, and the surface area of the exposed portions of the dispersed fibers 3 and dispersed particles 4 can be further increased. .

Although the present invention is not limited by any particular theory, the reason why the present invention is effective is that dispersed fibers made of an organic material, particularly a water-absorbing organic material, are made from a metal material and/or an insoluble compound thereof. It is thought that it acts on various dispersed particles and expresses antibacterial and antiviral functions. The following mechanisms have been proposed as one mechanism by which metal particles such as copper exhibit antibacterial and antiviral properties.
1. Copper ions are eluted into water.
2. Copper ions react with oxygen to generate active oxygen.
3. Copper ions and active oxygen reduce bacteria and viruses.

Here, the polyolefin resin used as the base material is excellent in hydrolysis resistance, but has low hydrophilicity. It is difficult to develop antiviral properties. On the other hand, according to the present invention, in a composition containing dispersed fibers made of an organic material, for example, it is possible to take in moisture from the outside along the interface between the base material and the dispersed fibers, and the surface of the metal-based material that constitutes the dispersed particles. can be supplied with moisture. Here, when the dispersed fibers are made of a water-absorbing organic material, the composition is imparted with hydrophilicity, which makes it easier to take in moisture from the outside. In particular, when at least a part of each of the dispersed fibers and dispersed particles in the antiviral composition exists in a state exposed from the base material, the composition becomes water-permeable, so the surface of the metal-based material has sufficient a sufficient amount of water is supplied. Therefore, it is believed that the ionization of the metal and/or its insoluble compounds is promoted and sufficient antiviral properties are exhibited.

In the antiviral composition of the present invention, the proportions of the base material, dispersed fibers and dispersed particles are preferably in the range of 40 to 80%:5 to 55%:1 to 25% by mass percentage. . Moreover, it is preferable that at least part of each of the dispersed fibers and the dispersed particles is exposed from the base material. Each component constituting the antiviral composition of the present invention is described below.

<Base material>
The antiviral composition of the present invention contains a polyolefin resin as a base material. In the present invention, the polyolefin resin includes homopolymers and copolymers based on olefin monomers such as ethylene and propylene. Examples include polypropylene resins and polyethylene resins such as polypropylene, polyethylene, polyisobutylene, polymethylpentene, ethylene-propylene copolymer, propylene-α-olefin copolymer, and ethylene-α-olefin copolymer; ethylene vinyl acetate Copolymers, copolymers of olefin monomers and other monomers such as ethylene-(meth)acrylic acid ester copolymers; halogenated polyolefins such as polyvinyl chloride, polyvinylidene chloride and chlorinated polyethylene; and polyacrylonitrile and copolymers thereof, such as acrylonitrile-styrene copolymers (AS resins, ABS resins), etc., but are not limited thereto. A plurality of types of polyolefin-based resins can also be used in combination.

However, in the antiviral composition of the present invention, the polyolefin resin preferably does not have functional groups such as halogens and nitrile groups. If the base material is a polyolefin resin containing only carbon, hydrogen, and optionally oxygen atoms, which does not contain halogens, etc., the weight of the antiviral composition can be reduced, and harmful gases are generated when burned. Since there is no fear, it is also advantageous from an environmental point of view.

The polyolefin-based resin of the base material is more preferably one or more resins selected from the group consisting of polypropylene-based resins, polyethylene-based resins, and ethylene-vinyl acetate copolymers. Here, the constituent molar ratio of the olefin monomer in the copolymer is preferably 60% or more, more preferably 80% or more, and particularly preferably 90% or more. Moreover, when the constituent molar ratio of the olefin monomer in the base material is high, the antiviral composition can be made lighter and have excellent resistance to hydrolysis and the like. For example, an ethylene-vinyl acetate copolymer having a vinyl acetate monomer composition molar ratio of 40% or less, particularly 20% or less, for example, 0.1 to 5 mol% is used. More preferably, the base material is a resin containing substantially only olefin, such as polypropylene resin or polyethylene resin.

(polypropylene resin)
In the present invention, polypropylene-based resins include propylene homopolymers as well as copolymers of propylene and other α-olefins, such as propylene-α-olefin copolymers and propylene-ethylene-α-olefin copolymers. also includes In the present invention, resins containing both ethylene and propylene components are classified as polypropylene resins.

　Polypropylene-based resins are lightweight, high-strength, and excellent in flexibility and heat resistance, so they are ideal as a base material for the antiviral composition of the present invention. From the viewpoint of strength and heat resistance, a polypropylene-based resin, at least a portion of which forms a crystal structure at room temperature (25° C.), is preferable in the molded article of the present invention. Differential scanning calorimetry (DSC measurement) of a molded article containing such a polypropylene-based resin reveals a melting peak at 164±5° C. associated with melting of polypropylene crystals.

However, the polypropylene resin used as the base material in the antiviral composition of the present invention is not particularly limited. For example, the propylene homopolymer having any structure such as isotactic, atactic, and syndiotactic may be used. Any of random copolymers, block copolymers, and alternating copolymers can be used as copolymers. The molecular weight is also not particularly limited, and for example, a polypropylene resin having a weight average molecular weight of 1,000 to 1,000,000, particularly 3,000 to 300,000 can be used. The melt flow rate (MFR) of the polypropylene resin is also not particularly limited. 10 minutes, particularly 1 to 30 g/10 minutes of the resin may be used. Moreover, these polypropylene-based resins may be used alone or in combination of two or more.

The α-olefin in the propylene-α-olefin copolymer is preferably 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-butene, 1-hexene and 1-octene are more preferred.

Propylene-α-olefin random copolymers include, for example, propylene-ethylene random copolymers, propylene-1-butene random copolymers, propylene-1-hexene random copolymers, and propylene-1-octene random copolymers. Amalgamation etc. are mentioned.

Examples of the propylene-ethylene-α-olefin copolymer include propylene-ethylene-1-butene copolymer, propylene-ethylene-1-hexene copolymer, propylene-ethylene-1-octene copolymer and the like. be done.

The propylene block copolymer is obtained, for example, by copolymerizing a propylene homopolymer component or a copolymer component mainly composed of propylene, at least one monomer selected from ethylene and α-olefins, and propylene. A copolymer composed of a copolymer component obtained from the above can be used. Examples include (propylene)-(propylene-ethylene) copolymer, (propylene)-(propylene-ethylene-1-butene) copolymer, (propylene)-(propylene-ethylene-1-hexene) copolymer, (propylene)-(propylene-1-butene) copolymer, (propylene)-(propylene-1-hexene) copolymer, (propylene-ethylene)-(propylene-ethylene) copolymer, (propylene-ethylene) -(propylene-ethylene-1-butene) copolymer, (propylene-ethylene)-(propylene-ethylene-1-hexene) copolymer, (propylene-ethylene)-(propylene-1-butene) copolymer, (propylene-ethylene)-(propylene-1-hexene) copolymer, (propylene-1-butene)-(propylene-ethylene) copolymer, (propylene-1-butene)-(propylene-ethylene-1-butene ) copolymer, (propylene-1-butene)-(propylene-ethylene-1-hexene) copolymer, (propylene-1-butene)-(propylene-1-butene) copolymer, (propylene-1- butene)-(propylene-1-hexene) copolymer and the like.

Of these polypropylene-based resins, propylene homopolymer, propylene-ethylene random copolymer, propylene-1-butene random copolymer, propylene-ethylene-1-butene copolymer or propylene block copolymer are preferred.

(polyethylene resin)
In the present invention, polyethylene-based resins include ethylene homopolymers as well as copolymers of ethylene and other α-olefins, such as ethylene-α-olefin copolymers. Polyethylene-based resins are excellent in moldability, inexpensive and economical, and therefore are suitable as the base material for the antiviral composition of the present invention. From the standpoint of moldability, it is preferable to use a polyethylene-based resin, at least a part of which forms a crystal structure at room temperature (25° C.) in the molded article of the present invention. When differential scanning calorimetry (DSC measurement) is performed on a molded product containing such a polyethylene resin, a melting peak is observed at 124±5° C. due to melting of polyethylene crystals. Even when an acid-modified polyethylene resin, which will be described later, is used, a melting peak associated with melting of polyethylene crystals may be observed at 124±5°C.

However, the polyethylene-based resin used as the base material in the antiviral composition of the present invention is not particularly limited, and examples thereof include ethylene homopolymers and ethylene-α-olefin copolymers. These polyethylene-based resins may be used alone or in combination of two or more. Preferred α-olefins are 1-butene, 1-pentene, 1-hexene and 1-octene.

Depending on the density or properties of polyethylene, high density polyethylene (HDPE, density about 0.92 to 0.96), low density polyethylene (LDPE, density about 0.91 to 0.92), ultra low density polyethylene ( VLDPE, density of about 0.9 or less), linear low-density polyethylene (LLDPE, density of about 0.94 or less), ultra-high molecular weight polyethylene (UHMW-PE, mass average molecular weight of about 1,5000,000 or more), etc. However, any of these polyethylene resins may be used in the present invention. There are no particular restrictions on its molecular weight or branching state.

Examples of ethylene-α-olefin copolymers include ethylene-1-butene copolymers, ethylene-1-pentene copolymers, ethylene-1-hexene copolymers, ethylene-1-octene copolymers, and the like. mentioned.

(Ethylene vinyl acetate copolymer)
Ethylene-vinyl acetate copolymers are copolymers of ethylene and vinyl acetate. Various varieties with different copolymerization ratios are on the market, and any of them can be used in the present invention. Examples thereof include vinyl acetate-modified polyethylene having a vinyl acetate content (mass ratio of the vinyl acetate monomer component in the copolymer) of about 4% or less, and general-purpose ethylene-vinyl acetate copolymer having a vinyl acetate content of about 4 to 30%. However, higher vinyl acetate copolymers, for example 60% vinyl acetate, can be used. Ethylene-vinyl acetate copolymers are flexible, glossy, and exhibit high adhesiveness as compared to polyethylene resins and the like. In addition, a copolymer having a higher vinyl acetate content tends to be more flexible.

(Modified polyolefin resin)
The antiviral composition of the present invention may contain a modified polyolefin resin as part of the polyolefin resin. For example, a modified polyethylene resin may be used as the polyethylene resin, or an acid-modified polyethylene resin may be included together with a non-acid-modified polyethylene resin. That is, the term "polyolefin-based resin" in the present invention includes modified polyolefin resins such as acid-modified polyethylene resins. By containing the modified polyolefin resin, it is possible to improve the dispersion state of other components in the base material, such as dispersed particles of cellulose fibers and metals, which will be described later.

The modified polyolefin resin is not particularly limited, but examples include those obtained by graft-modifying a polypropylene resin or polyethylene resin with an unsaturated carboxylic acid, alkoxysilane, or a derivative thereof. Examples of unsaturated carboxylic acids include maleic acid, fumaric acid, itaconic acid, acrylic acid, and methacrylic acid. Examples of unsaturated carboxylic acid derivatives include maleic anhydride, itaconic anhydride, methyl acrylate, Ethyl acrylate, butyl acrylate, glycidyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, glycidyl methacrylate, monoethyl maleate, diethyl maleate, monomethyl fumarate, dimethyl fumarate, etc. mentioned. An unsaturated carboxylic acid anhydride is preferred as the unsaturated carboxylic acid derivative. Among these unsaturated carboxylic acids and/or derivatives thereof, maleic anhydride is particularly preferred.

As the alkoxysilane, for example, an alkoxysilane compound having a functional group for grafting is preferable. The silane coupling agent to be used has a site (group or atom) capable of undergoing a grafting reaction with the polyolefin resin in the presence of radicals generated by decomposition of the organic peroxide, and an alkoxysilyl group. can be done. A group containing an ethylenically unsaturated group is exemplified as the site that can be grafted onto the polyolefin resin. Examples of groups containing an ethylenically unsaturated group include, but are not limited to, vinyl groups, allyl groups, (meth)acryloyloxy groups, (meth)acryloyloxyalkylene groups, and p-styryl groups. The alkoxysilyl group may be in the form of a trialkoxysilyl group, a dialkoxysilyl group, or a monoalkoxysilyl group, and it is preferable to use a trialkoxysilane compound. The alkoxy group of the alkoxysilyl group preferably has 1 to 6 carbon atoms, more preferably a methoxy group or an ethoxy group. The silane coupling agent preferably has an ethylenically unsaturated group-containing group and an alkoxysilyl group. One type of silane coupling agent may be used, or two or more types may be used.

Specific examples of the silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltributoxysilane, vinyldimethoxyethoxysilane, vinyldimethoxybutoxysilane, vinyldiethoxybutoxysilane, allyltrimethoxysilane, allyltriethoxysilane. Vinylsilane compounds such as silane, vinyltriacetoxysilane, trimethoxy(4-vinylphenyl)silane, 3-(trimethoxysilyl)propyl (meth)acrylate, 3-(methyldimethoxysilyl)propyl (meth)acrylate, (meth) ) 3-(methyldiethoxysilyl)propyl acrylate, 3-(triethoxysilyl)propyl (meth)acrylate, 3-(methoxydimethylsilyl)propyl (meth)acrylate and other (meth)acrylsilane compounds, etc. mentioned. Among them, the use of vinyltrimethoxysilane and/or (trimethoxysilyl)alkyl (meth)acrylate is particularly preferred. The alkyl group of (trimethoxysilyl)alkyl (meth)acrylate preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and particularly preferably a propyl group. From the viewpoint of increasing the tensile strength of the molded article, it is preferable to use 3-(trimethoxysilyl)propyl methacrylate.

The amount of modification in the modified polyolefin resin is not particularly limited, but is preferably 0.2 to 10% by mass, more preferably 1 to 5% by mass relative to 100% by mass of the polyolefin resin (before modification). In addition, when a modified polyolefin resin is used in the antiviral composition of the present invention, the content thereof is preferably about 1 to 20 parts by mass, particularly about 5 to 15 parts by mass with respect to 100 parts by mass of the polyolefin resin. .

(Base material content)
As described above, in the antiviral composition of the present invention, the proportions of the base material, dispersed fibers, and dispersed particles described later are 40 to 80%: 5 to 55%: 1 to 25% by mass. A range is preferred. If the content of the base material containing the polyolefin resin, preferably the base material substantially made of the polyolefin resin, is 40% by mass or more relative to the entire antiviral composition, good moldability is likely to be exhibited. There are advantages. On the other hand, when the same amount is 80% by mass or less, that is, when the content of the dispersed fibers and the dispersed particles of the metallic material is 20% by mass or more, good antibacterial and antiviral properties are likely to be exhibited. More preferably, the content of the base material in 100% by mass of the antiviral composition is 48-78% by mass, more preferably 55-75% by mass.

<Dispersed fiber>
In the antiviral composition of the present invention, dispersed fibers made of an organic material, particularly a water-absorbing organic material, are dispersed in the base material as described above, and dispersed particles made of a metal material and/or an insoluble compound thereof (metal system-dispersed particles). These dispersed fibers are considered to function as an antiviral aid that assists the antiviral properties of the metal-based dispersed particles described later.

The dispersed fibers in the present invention may be of any type as long as they are fibers made of an organic material (organic fibers), and there are no particular restrictions on the fiber length, fiber diameter, and the like. Preferably, fibers (water-absorbing organic fibers) made of organic materials having water-absorbing properties (water-absorbing organic materials) are used. The coexistence of the water-absorbing organic fibers facilitates the supply of moisture to the surface of the metal material forming the dispersed particles, so that the antibacterial and antiviral effects of the composition are further enhanced. Examples of such organic fibers include natural fibers such as cellulose fibers, wool and silk; regenerated cellulose fibers, polyester fibers such as polyethylene terephthalate fibers, polyethylene naphthalate fibers, polyphenylene sulfide fibers, polyamide fibers such as nylon ) fibers and synthetic fibers such as polyimide fibers. In addition, "organic fiber" refers to a fiber mainly made of organic material, and in addition to organic material, it may contain unavoidable mixtures such as catalyst residues during synthesis, additives for processing, and inorganic substances derived from raw materials.

Among the above-described fibers, from the viewpoint of cost, workability, and water absorption, more preferably one or more fibers selected from the group consisting of cellulose fibers, regenerated cellulose fibers, and polyester fibers, and particularly natural or regenerated cellulose fibers. preferable. That is, the dispersed fibers preferably contain cellulose fibers, and more preferably mainly consist of cellulose fibers, particularly natural cellulose fibers. For example, the ratio of natural or regenerated cellulose fibers to the entire dispersed fibers can be 70% by mass or more, 80% by mass or more, or 90% by mass or more, and it is particularly preferable that almost all of the dispersed fibers are cellulose fibers. . Cellulose fibers have higher strength and higher rigidity than polyolefin resins. Therefore, cellulose fibers have the effect of reinforcing the base material and increasing the rigidity (flexural modulus) of the antiviral composition and molded article.

(cellulose fiber)
Cellulose fibers are fibrous cellulose, and the main component is a kind of polysaccharide represented by the molecular formula (C ₆ H ₁₀ O ₅ ) _n , so they are excellent in water absorption. The cellulose fibers used in the present invention are not particularly limited, but plant-derived natural cellulose fibers are preferable, and in particular, fine plant-derived cellulose fibers, since industrial utilization methods have been established and they are readily available. , for example flour pulp, is preferred. In a broad sense, "cellulose fiber" includes regenerated cellulose fiber, and regenerated cellulose can be blended in the antiviral composition of the present invention in the same manner as natural cellulose. However, since natural cellulose and regenerated cellulose have different sources of raw materials, hereinafter, unless otherwise specified, "cellulose" refers to natural cellulose, and regenerated cellulose will be described separately.

In general, plant-derived cellulose fibers are bundles of 30 to 40 cellulose molecules that form ultra-thin, highly crystalline microfibrils with a diameter of about 3 nm and a length of several hundred nm to several tens of μm. A bundled structure is formed through the soft non-crystalline portion. The powdery pulp (powdered cellulose) is this bundle-like aggregate. In the present invention, the term cellulose fiber is used in the sense of including the state of defibrated microfibrils in addition to the above-mentioned microfibril bundle (unfibrillated state).

Plant-derived cellulose fibers are not particularly limited, but examples include wood, bamboo, hemp, jute, kenaf, agricultural waste (e.g., straw such as wheat and rice, stalks such as corn and cotton, and sugarcane). and those derived from cloth, recycled pulp, waste paper, wood powder, and the like. Preferably, wood-derived cellulose fibers, in particular wood pulp, are used. Compared to other plant-derived pulps, wood pulp has the advantage of being stably supplied with less seasonal fluctuations in production volume. Pulp is also a raw material for paper, and tracheids extracted from plants are chemically composed mainly of cellulose.

Plant-derived cellulose fibers often contain components other than cellulose, such as lignin and hemicellulose. In the present invention, such components other than cellulose need not be completely removed, but a small amount is preferable. For example, when the amount of lignin or hemicellulose is large, as in a composition containing wood flour itself, it becomes difficult to impart desired mechanical properties. In the present invention, the content of cellulose in the cellulose fiber raw material is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more. A particularly preferred cellulosic fiber raw material of this type is, for example, kraft pulp.

Kraft pulp is a general term for pulp obtained by removing lignin and hemicellulose from wood or other plant materials through chemical treatment such as caustic soda to extract nearly pure cellulose. It is composed mainly of cellulose molecules and small amounts of hemicellulose and lignin.

In the cellulose fiber contained in the antiviral composition of the present invention, part of the hydroxyl groups in the cellulose molecule may be acetylated or carboxylated, and the hydrogen atoms in the hydroxyl groups may be replaced by sodium, potassium, or the like. It may be substituted with a metal ion, an ammonium ion, or the like.

(regenerated cellulose fiber)
Regenerated cellulose fibers are fibers obtained by reprecipitating cellulose from a solution. For example, dissolving cellulose in a cuprammonium oxide solution (Schweitzer's solution) or sodium hydroxide solution gives a highly viscous viscose. Cellulose can be regenerated by extruding this viscose as a spinning solution through pores into a coagulating bath such as sulfuric acid. Most regenerated cellulose fibers are produced by such a viscose method and are called rayon. Various types of regenerated cellulose fibers can be obtained depending on the type of viscose, degree of aging, coagulation bath, drawing and finishing conditions. Esterification treatment with acetic anhydride or the like may be performed. Also known are solvent-spun rayon in which cellulose is dissolved in a solvent such as N-methylphorpholine N-oxide and spun, and copper-ann rayon. Any of these various regenerated cellulose fibers can be used in the present invention. A combined use with natural cellulose fibers is also possible.

(polyester fiber)
Polyester fibers are fibers composed of long-chain synthetic polymers in which monomer units are mainly ester-bonded. Most of the general-purpose polyester fibers are fibers mainly composed of polymers composed of dihydric alcohol and terephthalic acid, and polyethylene terephthalate (PET) fibers are particularly common. In addition, a polyester fiber having an ether bond, which is obtained by copolymerizing alkylene paraoxybenzoate or the like, is also known. Various types of polyester fibers can be produced depending on the monomer component, degree of polymerization, synthesis method, drawing conditions, and the like. Any of these various polyester fibers can be used in the present invention. A combination with natural and/or regenerated cellulose fibers is also possible.

The average fiber diameter and average fiber length of the dispersed fibers are not particularly limited, and can be appropriately selected depending on the application. However, from the viewpoint of the dispersibility of the fibers in the antiviral composition and the moldability and reinforcing properties of the antiviral composition, the average fiber diameter of dispersed fibers such as cellulose fibers is preferably 1 to 50 μm, more preferably 5 to 40 μm. is more preferable, 10 to 30 μm is still more preferable, and 15 to 25 μm is particularly preferable. For the same reason, the average fiber length of dispersed fibers such as cellulose fibers is preferably 10 to 3000 μm, more preferably 20 to 2500 μm, still more preferably 100 to 2000 μm, and particularly preferably 400 to 1000 μm. The above average fiber diameter and average fiber length are the fiber length and fiber diameter measurement by a fiber analyzer, the longitudinal size of dispersed fibers observed with an optical microscope or an electron microscope, and the transverse size. It can be obtained by averaging each of the fiber diameters. The field of view for obtaining the average fiber diameter and average fiber length by microscopic observation is, for example, 960 μm×1200 μm.

The content of dispersed fibers is not particularly limited, and can be appropriately selected depending on the application. Preferably, it is 7 to 110 parts by mass, more preferably 10 to 55 parts by mass, based on 100 parts by mass of the base material. If the content of the dispersed fibers is within this range, the composition exhibits sufficient antiviral properties and is excellent in mechanical strength such as flexural modulus and appearance. On the other hand, when the content of the dispersed fibers is large, the moldability is inferior, and it may become difficult to mold the film into a sheet film shape. If too little dispersed fiber is added, the antibacterial or antiviral properties of the composition may be poor.

In the antiviral composition of the present invention, as described above, from the viewpoint of moldability, antibacterial properties, and antiviral properties of the antiviral composition, the abundance ratio of the base material, the dispersed fibers, and the metal-based dispersed particles described later is is preferably in the range of 40-80%:5-55%:1-25% in terms of mass %. More preferably, the content of dispersed fibers is 8 to 51% by mass, more preferably 10 to 40% by mass, based on 100% by mass of the total antiviral composition.

<Dispersed particles>
In addition to the above components, the antiviral composition of the present invention comprises dispersed particles composed of a metal material, particularly a metal material that exhibits an antiviral function in the presence of water (antiviral metal material) and/or an insoluble compound thereof, That is, it further contains metal-based dispersed particles.

Dispersed particles include, but are not limited to, those containing one or more metals and/or insoluble compounds thereof selected from the group consisting of copper, silver, zinc, nickel, aluminum, palladium, tin and iron. not. Here, the "insoluble compounds" of these metals are compounds that are almost insoluble in water, and may be oxides or hydroxides. For example, they may be oxide particles or hydroxide particles of the antiviral metal material, or metal particles partially or entirely covered with oxide or hydroxide. The metal material and/or its insoluble compound may be, for example, an alloy or composite oxide containing a plurality of the above metals such as copper and silver. Copper or its alloys, such as brass, are particularly preferred. Such metallic materials exhibit a high antiviral function, especially in the presence of water, and act as antiviral agents in the antiviral composition of the present invention. In addition, "dispersed particles composed of metallic materials and/or insoluble compounds thereof" refer to particles composed mainly of metallic materials and/or insoluble compounds of these metallic materials, and unavoidable mixtures derived from raw materials, etc. Alternatively, it may contain a surface modifier or the like for improving dispersibility.

Since the antiviral composition of the present invention contains dispersed particles composed of a metallic material and/or an insoluble compound thereof instead of a metal salt as an antiviral agent, the antiviral agent is not extracted into water or the like during use. . In addition, unlike organic antibacterial agents, there is no risk of volatilization or decomposition. Therefore, the antibacterial and antiviral properties do not deteriorate with long-term use, and there is no risk of causing salt damage to peripheral equipment. On the other hand, when the antiviral composition of the present invention or its molded product comes into contact with water such as aquarium water, sewage, or body fluids such as perspiration, the antiviral function based on the dispersed particles composed of the metal material and/or its insoluble compound is activated. demonstrated.

Such dispersed particles in the antiviral composition of the present invention may have any shape, and at least one of shapes such as spherical, fibrous powder, and scaly can be selected. Particles in which a plurality of shapes are mixed may be used. Above all, from the viewpoint of ensuring the moldability of the composition, the dispersed particles are preferably spherical.

The particle diameter of the metal-based dispersed particles is not particularly limited, but the average particle diameter is preferably 0.01 μm or more and 100 μm or less, more preferably 0.1 μm or more and 50 μm or less, and 1 μm or more and 40 μm. The following are particularly preferred. In general, the smaller the diameter of the metal-based particles, the more likely they are to exhibit antiviral properties. If the particle size is large, the surface properties of the molded article may be inferior due to the unevenness of the dispersed metal particles. The average particle size can be determined by a dynamic light scattering method, a laser diffraction method, or the like.

In the antiviral composition of the present invention, as described above, from the viewpoint of the moldability, antibacterial properties, and antiviral properties of the antiviral composition, the abundance ratio of the base material, the dispersed fibers, and the metal-based dispersed particles is %, preferably in the range of 40-80%:5-55%:1-25%. More preferably, the content of the metal-based dispersed particles is 1 to 20% by mass, more preferably 1 to 15% by mass, based on 100% by mass of the total antiviral composition. That is, the ratio of the base material, the dispersed fibers and the dispersed particles in the antiviral composition of the present invention is more preferably 48-78% by mass: 8-51% by mass: 1-20% by mass, and more preferably 48-50% by mass. 75% by mass: 10 to 51% by mass: 1 to 15% by mass.

(other ingredients)
In addition to the base material (polyolefin-based resin), dispersed fibers, and (metal-based) dispersed particles, the antiviral composition of the present invention contains resins other than polyolefin-based resins, as long as the effects of the present invention are not impaired. Various commonly used additives may be included.

Examples of additives include antioxidants, light stabilizers, radical scavengers, UV absorbers, colorants (dyes, organic pigments, inorganic pigments), fillers, lubricants, plasticizers, processing aids such as acrylic processing aids, etc. agents, foaming agents, lubricants such as paraffin wax, surface treatment agents, crystal nucleating agents, mold release agents, anti-hydrolysis agents, anti-blocking agents, anti-static agents, anti-fogging agents, anti-fogging agents, ion trap agents, Examples include, but are not limited to, retardants, flame retardant aids, and the like. Such other components are within a range that does not impair the purpose of the present invention, for example, in an amount of about 0.1 to 10% by mass, particularly about 0.5 to 5% by mass, based on 100% by mass of the total antiviral composition. It can be contained as appropriate.

[Method for producing antiviral composition]
The antiviral composition of the present invention is prepared by melt-mixing (kneading) at least a base material (polyolefin resin), dispersed fibers and (metallic) dispersed particles, for example, and dispersing fibers and (metallic) in the polyolefin resin. system) can be produced by dispersing dispersed particles. The present invention also includes a method of making an antiviral composition comprising the step of melt-blending the base material, dispersed fibers, and dispersed particles.

In the present invention, "melt mixing" means mixing the polyolefin resin in a melted state with components such as dispersed fibers and (metallic) dispersed particles. In addition, "mixing" means that the melted polyolefin resin is melted, and as long as it can create a state in which components such as dispersed fibers and (metallic) dispersed particles are mixed, it may be uniform or non-uniform. may Melt-mixing is prepared by, for example, mixing components such as dispersed fibers and (metallic) dispersed particles in a melted state of polyolefin resin using an extruder, a kneader, a Banbury mixer, or the like. can be done. In particular, use of a twin-screw extruder is preferred.

There are no particular restrictions on the mixing order of each component. However, in the present invention, a molten mixture A of the polyolefin resin and the (metallic) dispersed particles and a molten mixture B of the polyolefin resin and the dispersed fibers are respectively prepared, melt-mixed, and then molded. is preferable from the viewpoint of improving the dispersion of the dispersed fibers and the (metallic) dispersed particles in the polyolefin resin. Further, (metal-based) dispersed particles may be mixed with the molten mixture B prepared as described above. The molten mixture A of the polyolefin resin and the (metallic) dispersed particles and the molten mixture B of the polyolefin resin and the dispersed fibers are pelletized as described below before mixing them from the viewpoint of handleability in the molding process. It is preferable to process it into a shape.

In the melt mixing step of the polyolefin resin and the dispersed fibers, from the viewpoint of improving the dispersed state of the dispersed fibers in the polyolefin resin as the base resin, the alkoxysilane-modified polyolefin resin and the dispersed fibers are alkoxylated before melt mixing. Pre-mixing may be performed at a temperature below the melting point of the silane-modified polyolefin resin, or melt-mixing may be performed in the presence of a dispersing aid for dispersed fibers.

When melt mixing is performed in the presence of a dispersing aid for dispersed fibers, the dispersing aid for dispersed fibers can be added to a mixing device (eg, an extruder) and collected through a vent. As the dispersing aid for the dispersed fibers, it is preferable to use water or the like from the viewpoint of less environmental load such as separation or recovery and less adverse effect on the dispersed fibers even if it remains.

[Molded body]
The present invention also includes molded articles comprising the antiviral composition described above. The shape of the molded product is not particularly limited, and various desired shapes such as sheet-like, tubular, and other complicated shapes can be used according to the purpose and application. The molded article of the present invention may be a foam. In the molded article of the present invention, it is preferable that at least a part of each of the dispersed fibers and the dispersed particles is present on the surface of the molded article in a state of being exposed from the base material. Particularly high antiviral properties can be exhibited when a part of the dispersed fibers and dispersed particles are exposed from the base material.

The method for producing the molded article of the present invention is not particularly limited as long as it can be molded into the desired shape, and any of conventionally known methods such as extrusion molding, injection molding, vacuum molding, blow molding, and calender molding can be used. be. Depending on the shape of the molded article, for example, an extruder may be used to carry out the melt mixing and molding of the molded article in one step. Alternatively, the produced antiviral composition may be once pelletized and molded by injection molding or the like. The pelletization method is not particularly limited, and a general-purpose pelletizer or the like can be used. In the case of producing a foam, for example, liquid phase foaming methods such as injection foaming, extrusion foaming, foam blowing, etc., or solid phase foaming methods such as bead foaming, batch foaming, press foaming, normal pressure secondary foaming, etc. are known. Any method can be used.

The molding temperature in injection molding, extrusion molding, etc. varies to some extent depending on the molding method and the type of polyolefin resin used, so it cannot be defined unconditionally, but preferably the melting point of the base material +5 to The temperature can be about 100°C, particularly about +10 to 50°C, for example, 180 to 260°C, more preferably 190 to 230°C. At such a temperature, the antiviral composition according to the present invention can be molded into a predetermined shape with good drawdown properties and spreadability without causing local denaturation.
The form of the molded article does not have to consist of only the antiviral composition of the present invention. For example, a laminate of two or more layers containing the antiviral composition of the present invention and other resin compositions. It may consist of a structure.

[Use]
Since the molded article of the present invention exhibits excellent antibacterial and antiviral properties, it can be used by many users, including products for various medical and sanitary purposes, materials for transportation equipment such as automobile parts, interiors, and exteriors. It is useful as a material for durable products. In particular, molded articles containing cellulose fibers, especially natural cellulose fibers, as dispersed fibers have the inherent properties of cellulose fiber reinforced resin materials, such as lightness and high specific strength, and have not only antibacterial and antiviral properties, but also rigidity and resistance. It can be used for various applications such as members or materials that require impact resistance.

Specifically, the molded article of the present invention can be used as the following products, or their parts and/or members. Examples include transportation equipment (automobiles, motorcycles, trains, aircraft, etc.), structural members of robot arms, robot parts for amusement, prosthetic limb members, home appliance materials, OA equipment housings, information processing equipment, mobile terminals, building materials, films for houses. , drainage equipment, toiletry product materials, various tanks, containers, sheets, packaging materials, toys, stationery, food containers, bobbins, tubes, cable troughs, resin gutters, furniture materials (wall materials, handrails, etc.), shoes, and sporting goods etc. The molded article of the present invention is suitable as a material for transportation equipment such as automobile parts.

Materials for transportation equipment include materials for vehicles, such as trims such as dashboard trims, door trims, pillar trims, meter panels, meter housings, glove boxes, package trays, roof headlinings, consoles, and instrument panels. , armrests, seats, seat backs, trunk lids, trunk lid lowers, door inner panels, pillars, spare tire covers, door knobs, light housings, interior parts such as back trays, bumpers, bonnets, spoilers, radiator grills, fenders, fender liners Exterior parts such as rocker panels, side steps, door/outer panels, side doors, back doors, roofs, roof carriers, wheel cap covers, door mirror covers, under covers, etc., battery cases, engine covers, fuel tanks, fuel Tubes, fuel filler boxes, air intake ducts, air cleaner housings, air conditioner housings, coolant reserve tanks, radiator reserve tanks, window washer tanks, intake manifolds, rotating members such as fans and pulleys, parts such as wire harness protectors, junction boxes or connectors, integrally molded parts such as front-end modules, front-end panels, and the like.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples except as specified above.

(Example/Comparative example)
Various compositions and molded articles were prepared, and their antibacterial and antiviral properties and water absorption were evaluated.

-Materials used-
The materials used are shown below.
<Base material>
Polypropylene resin: J106MG (trade name), isotactic polypropylene resin manufactured by Prime Polymer Co., Ltd., MFR: 10 g/10 min
<Dispersed fiber>
Cellulose fiber-1: ARBOCEL B400 (trade name), cellulose fiber manufactured by RETTENMAIER, average fiber length 450 μm, average fiber diameter 15 μm
Cellulose fiber-2: Pulp sheet pulverized product, fiber obtained by pulverizing Harmac R (trade name) pulp sheet manufactured by Harmac Pacific using a pulverizer; average fiber length 900 μm, average fiber diameter 25 μm
<Dispersed particles>
Copper powder-1: LPW-CU-AAJK (trade name), copper powder manufactured by LPW TECHNOLOGY LTD, shape: spherical, average particle size 30 μm
Copper powder-2: Cu-HWQ (trade name), copper powder manufactured by Fukuda Metal Foil & Powder Co., Ltd., shape: spherical, average particle size 1.5 μm

- Antibacterial evaluation -
Antibacterial evaluation was performed according to JIS Z 2801:201. Using the following test bacteria, the antibacterial activity value was determined at a temperature of 35°C, an action time of 24 hours, an inoculum solution concentration of 5.4 x 105 cfu/ml, and an inoculum amount of 0.4 ml/sample.
・Staphylococcus aureus (NBRC12732)
・ Escherichia coli (NBRC3972)
The antibacterial activity value was calculated from the following formula.
Antibacterial activity value = LogA-LogB
A: Number of viable bacteria per unit area of standard sample (polypropylene resin alone) B: Number of viable bacteria per unit area of test sample The obtained value is rounded to the second decimal place, and the activity value is less than 1.0. If the antibacterial property is inferior, "x", if the activity value is 1.0 or more and less than 2.0, the antibacterial property is good, "○", and if the activity value is 2.0 or more It was evaluated as "⊚" as having excellent antibacterial properties.

-Antiviral evaluation-
The antiviral evaluation was performed in accordance with JIS R 1756:2020 (visible light-responsive photocatalyst, antiviral, film adhesion method). Using the following test phage, etc., temperature: 25 ° C ± 3 ° C, action time: 4 hours, inoculation phage solution concentration: 7.6 × 10 pfu / ml, inoculation amount: 0.4 ml / sample Antiviral activity value asked for
- Bacteriophage Qβ (NBRC20012) [Host E. coli (NBRC106373)]
- Bacteriophage Φ6 (NBRC 105899) [host Pseudomonas syringae (NBRC 14084)]
The antiviral activity value was calculated from the following formula.
Antiviral activity value (dark) = LogC-LogD
C: Infectivity value of standard sample (polypropylene resin alone) D: Infectivity value of test sample The obtained value is rounded to the second decimal place, and the activity value of less than 1.0 is considered to be inferior in antiviral activity. "X" indicates that the antiviral property is good when the activity value is 1.0 or more and less than 2.0, and "○" indicates that the antiviral property is good when the activity value is 2.0 or more. was evaluated as "◎".

-Evaluation of water absorption-
The amount of water absorption was calculated based on the following formula from the change in weight before and after drying, after holding each sample in an atmosphere of 25° C. and 50% humidity for 24 hours or more and vacuum drying at 80° C. for 24 hours.
Water absorption (mass%) = (mass before drying - mass after drying) / mass after drying x 100

(Example 1)
-Preparation of cellulose fiber masterbatch-
After sufficiently drying the polypropylene resin and the cellulose fiber-1, from two hoppers to a co-directional twin-screw extruder (trade name: KZW15TW-45MG-NH, manufactured by Technobell Co., Ltd.) with a screw diameter of 15 mm and L/D = 45. Each was charged and extruded into a strand with the die set at 190°C. The mixing was adjusted so that 25 parts by mass of cellulose fiber-1 was mixed with a total of 100 parts by mass of polypropylene resin and cellulose fiber-1. After cooling and cutting, a pellet-like cellulose fiber masterbatch was obtained.

- Addition of copper powder to cellulose fiber masterbatch -
After sufficiently drying the cellulose fiber masterbatch, the cellulose fiber masterbatch and the copper powder-1 were charged from two hoppers into the same twin-screw extruder, and extruded into strands with a die set at 190°C. The above mixing was adjusted so that 5 parts by mass of the copper powder-1 was mixed with a total of 100 parts by mass of the cellulose fiber masterbatch and the copper powder. After cooling and cutting, resin pellets with a diameter of about 2 mm and a height of about 3 mm were obtained. The mass ratio of polypropylene resin:cellulose fiber-1:copper powder-1 in 100 parts by mass of resin pellets was 71.25:23.75:5.00.

-Preparation of antibacterial/antiviral test piece-
The prepared resin pellets are put into the mold, and a small hot press molding machine (trade name: MP-WCH manufactured by Toyo Seiki Seisakusho Co., Ltd.) is used to form a press sheet with dimensions of about 100 mm x 100 mm x 1 mm at 190 ° C. and 20 MPa. was made. This was punched into a size of 50 mm×50 mm to obtain an antibacterial/antiviral test piece. When the cross section of this test piece was observed as a composition image with a scanning electron microscope (SEM device name: JSM-6390LV, manufactured by JEOL Ltd.), the metal-based dispersed particles were exposed on the surface as shown in FIG. was in a state. The obtained test pieces were subjected to the antibacterial/antiviral test as described above, and the results are shown in Table 1 together with the composition of the test pieces.

(Example 2)
An antibacterial/antiviral test was performed in the same manner as in Example 1, except that the mixing ratio of the cellulose fiber masterbatch and copper powder was set to 10 parts by mass of copper powder with respect to the total of 100 parts by mass of the cellulose fiber masterbatch and copper powder. got a piece The mass ratio of polypropylene resin:cellulose fiber-1:copper powder-1 in 100 parts by mass of the test piece was 67.50:22.50:10.00. Electron microscope (SEM) photographs of the surface and cross section of this test piece are shown in FIGS. In the test piece of Example 2, the dispersed state schematically shown in FIG. 2 was developed, and the cellulose fibers (dispersed fibers 13) and copper powder (dispersed particles 14) were not completely covered with the base material. , some of which were exposed on the surface of the test piece.

(Example 3)
Antibacterial / antibacterial / An antiviral test strip was obtained. The mass ratio of polypropylene resin:cellulose fiber-1:copper powder-2 in 100 parts by mass of the test piece was 67.50:22.50:10.00.

(Example 4)
An antibacterial/antiviral test piece was obtained in the same manner as in Example 3, except that the mixing ratio of copper powder was changed to 1 part by mass of copper powder for a total of 100 parts by mass of cellulose fiber masterbatch and copper powder. . The mass ratio of polypropylene resin:cellulose fiber-1:copper powder-2 in 100 parts by mass of the test piece was 74.25:24.75:1.00.

(Example 5)
The mixing ratio of cellulose fibers was changed to 50.5 parts by mass of cellulose fibers per 100 parts by mass of cellulose fiber masterbatch and copper powder (51 parts by mass per 100 parts by mass of polypropylene resin and cellulose fibers). An antibacterial/antiviral test piece was obtained in the same manner as in Example 4, except for the above. The mass ratio of polypropylene resin:cellulose fiber-1:copper powder-2 in 100 parts by mass of the test piece was 48.50:50.50:1.00.

(Example 6)
Example except that the cellulose fiber (cellulose fiber-1, average fiber diameter 15 μm, average fiber length 450 μm) used in Example 2 was replaced with one having an average fiber diameter 25 μm and an average fiber length 900 μm (cellulose fiber-2). An antibacterial/antiviral test strip was obtained in the same manner as in 2. The mass ratio of polypropylene resin:cellulose fiber-2:copper powder-1 in 100 parts by mass of the test piece was 67.50:22.50:10.00.

(Comparative example 1)
Antibacterial / antibacterial / antibacterial / antibacterial / An antiviral test strip was obtained. The mass ratio of polypropylene resin to copper powder-1 in 100 parts by mass of the test piece was 95.00:5.00.

(Comparative example 2)
Antibacterial / antibacterial / antibacterial / An antiviral test strip was obtained. The mass ratio of polypropylene resin to copper powder-1 in 100 parts by mass of the test piece was 90.00:10.00. An electron micrograph of the surface of this test piece is shown in FIG.

(Comparative Example 3)
An antibacterial/antiviral test piece was obtained in the same manner as in Example 1, except that copper powder was not added to the cellulose fiber masterbatch. The mass ratio of polypropylene resin to cellulose fiber-1 in 100 parts by mass of the test piece was 75.00:25.00. An electron micrograph of the surface of this test piece is shown in FIG.

Table 1 shows the composition and the evaluation results of the antibacterial/antiviral test for the antibacterial/antiviral test pieces obtained in each example and comparative example.

The results in Table 1 showed the following.
- Comparative Examples 1 and 2 are compositions in which only copper powder is added to polypropylene resin, and Comparative Example 3 is a composition in which only cellulose fibers are added to polypropylene resin. Although the compositions of Comparative Examples 1 and 2 exhibited antibacterial properties against Staphylococcus aureus, the antiviral activity values were low in all of Comparative Examples 1 to 3. It became clear that antiviral properties could not be imparted to the system resin.
・On the other hand, it has been shown that an antiviral composition containing a base material made of polypropylene resin, dispersed fibers (cellulose fibers), and dispersed particles (copper powder) has both antibacterial and antiviral properties. was done. Among them, in the compositions using copper powder with a small particle size in Examples 3 to 5 and the composition using cellulose long fibers in Example 6, high antibacterial and Antiviral activity values were achieved.
- All of the test pieces of Examples 1 to 6 and Comparative Example 3, which contained cellulose fibers, had water absorbency. On the other hand, the test pieces of Comparative Examples 1 and 2 had zero water absorption.
This result confirms that at least some of the cellulose fibers were exposed on the surface, and is consistent with the micrographs of FIGS. 3-6. The antiviral properties are not exhibited when some of the metal-based dispersed particles are exposed to the surface only as in the sample of Comparative Example 2, and the dispersed fibers (or through the interface between the dispersed fibers and the base material) are exposed from the outside. It is suggested that it is expressed by taking in moisture and bringing the metal-based dispersed particles inside the composition or molded article into contact with moisture.

REFERENCE SIGNS LIST 1 antiviral composition 2 base material 3 dispersed fibers 4 dispersed particles 11 compact 12 base material 13 dispersed fibers 14 dispersed particles

Claims

a base material containing a polyolefin resin;
Dispersed fibers made of an organic material;
and dispersed particles comprising a metallic material and/or an insoluble compound thereof.
The antiviral composition according to claim 1, wherein the organic material has water absorption properties, and the metallic material exhibits an antiviral function in the presence of water.
The antiviral property according to claim 1 or 2, wherein the proportion of the base material, the dispersed fibers and the dispersed particles is in the range of 40 to 80%:5 to 55%:1 to 25% by mass. Composition.
The antiviral property according to claim 1, 2, or 3, wherein the polyolefin-based resin is one or more resins selected from the group consisting of polypropylene-based resins, polyethylene-based resins, and ethylene-vinyl acetate copolymers. Composition.
The antiviral according to any one of claims 1 to 4, wherein the dispersed fibers are one or more fibers selected from the group consisting of cellulose fibers, regenerated cellulose fibers, and polyester fibers. sex composition.
The antiviral composition according to claim 5, wherein the dispersed fibers are cellulose fibers.
The antiviral composition according to claim 6, wherein the cellulose fibers have an average fiber length of 10 to 3000 µm and an average fiber diameter of 1 to 50 µm.
Any one of claims 1 to 7, wherein the dispersed particles contain one or more metals and/or insoluble compounds thereof selected from the group consisting of copper, silver, zinc, nickel, aluminum, palladium, tin and iron. 2. The antiviral composition according to item 1.
A molded article made of the antiviral composition according to any one of claims 1 to 8.