WO2014091861A1

WO2014091861A1 - Antimicrobial and antiviral composition, and method of producing the same

Info

Publication number: WO2014091861A1
Application number: PCT/JP2013/080733
Authority: WO
Inventors: Ding Li; Yasushi Kuroda; Yasuhiro Hosogi; Sou MIYAISHI
Original assignee: Showa Denko K.K.
Priority date: 2012-12-13
Filing date: 2013-11-07
Publication date: 2014-06-19
Also published as: KR20150088998A; JP2014118358A; JP6040021B2; TW201439236A; CN104837347A; CN104837347B

Abstract

An antimicrobial and antiviral composition, a method of producing the same, and the like are provided, which are capable of exhibiting excellent antimicrobial and antiviral properties for a long time through various uses. The antimicrobial and antiviral material includes cuprous oxide particles and a silica-coating layer on at least one part of the surface of the cuprous oxide particles, in which the content of the silica-coating layer is 5 to 20 parts by mass based on 100 parts by mass of the cuprous oxide particles, and the BET specific surface area of the cuprous oxide particles coated with silica is 5 to 100 m²/ g.

Description

ANTIMICROBIAL AND ANTIVIRAL COMPOSITION, AND METHOD OF PRODUCING

THE SAME

Technical Field

[0001]

The present invention relates to an antimicrobial and antiviral material, an antimicrobial and antiviral composition, a method of producing the same, a dispersion of the antimicrobial and antiviral composition, a coating agent containing the antimicrobial and antiviral composition, an antimicrobial and antiviral film, and an antimicrobial and antiviral article which are applied to construction materials, sanitary materials, antifouling materials, and the like in living environment. Background Art

[0002]

The copper (II) ion is known as an effective component for antimicrobial and antiviral properties. For example, Patent Document 1 discloses an antimicrobial and antiviral polymeric material having microscopic particles of ionic copper

encapsulated therein and protruding form surfaces there of.

Patent Documents 2 to 4 disclose that a copper (I) compound has more excellent antimicrobial and antivira performance than a copper (II) compound. Patent Document 5 discloses that nano particles formed of a mixed composition of copper, copper (II) oxide, and/or cuprous oxide has excellent antimicrobial and antiviral performance.

[0003]

A saccharide with a reducing aldehyde group, as typified by glucose or the like, is widely known to be used as a reducing agent for the synthesis of cuprous oxide. For example, Patent Documents 6 to 8 disclose that a reducing sugar such as glucose is used for the synthesis of various shapes of micron-sized cuprous oxide.

[0004]

In addition, the study to support a copper compound on a photocatalytic material so as to provide antimicrobial and antiviral performance is known. For example, Patent Document 9 discloses that a deactivator for phage viruses, which is formed of copper (II) oxide-supported titanium oxide to deactivate viruses under ultraviolet irradiation.

Patent Document 10 discloses that copper (I)

oxide-supported titanium oxide displays antiviral performance. Patent Document 11 discloses that copper (I) oxide displays high antimicrobial and antiviral performance.

[0005]

As a copper (I) compound exhibiting excellent antimicrobial and antiviral properties, cuprous oxide is known. However, nano particles of pure cuprous oxide are unstable in the atmosphere. Cuprous oxide is oxidized to copper (II) oxide gradually, causing the antimicrobial and antiviral performance to be lowered. However, Patent Documents 1 to 4 do not disclose such a problem of the decreased antimicrobial and antiviral properties.

Patent Document 5 does not disclose the evaluation of cuprous oxide nano particles alone or the problem of the decreased antimicrobial and antiviral properties caused by cuprous oxide nano particles easily oxidized in the atmosphere.

[0006]

In Patent Documents 6 to 8, a reducing agent is removed after cuprous oxide is synthesized. The cuprous oxide powder obtained by any of the methods described in these documents is oxidized easily in the atmosphere, so that the antimicrobial and antiviral properties may be lowered. Furthermore, micrometer-sized cuprous oxide obtained by any of the methods described in these documents has a smaller specific surface area, so that the antimicrobial and antiviral performance may be degraded.

[0007]

Patent Document 9 does not disclose that cuprous oxide displays extremely high antimicrobial and antiviral performance. Copper (II) oxide is considered to be preferably maintained on the surface of titanium oxide for an antimicrobial and antiviral purpose. Furthermore, Patent Document 9 does not describe the advantage that copper (II) oxide, to which cuprous oxide has been oxidized in the atmosphere, is reduced to cuprous oxide with a photocatalyst to sustain the antimicrobial and antiviral effect.

Patent Document 10 does not describe that the copper (I) oxide-supported titanium oxide is easily oxidized^' in the atmosphere. For the same reason as other documents, the antimicrobial and antiviral properties may be decreased.

In Patent Document 11, the copper (I) oxide is oxidized easily in the atmosphere, so that the antimicrobial and antiviral performance may be degraded. On this point, Patent Document 11 does not disclose a method of inhibiting the oxidation of copper (I) oxide.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1: JP 2003-528975 T

Patent Document 2: JP 2006-506105 T Patent Document 3: JP 2007-504291 T

Patent Document 4: JP 2008-518712 T

Patent Document 5: JP 2009-526828 T

Patent Document 6: JP 4401197 B

Patent Document 7: JP 4401198 B

Patent Document 8: JP 4473607 B

Patent Document 9: JP 4646210 B

Patent Document 10: CN 101322939 A

Patent Document 11: JP 2011-153163 A

Summary of the Invention

Problems to be Solved by the Invention

[0009]

An. object of the present invention is to provide an antimicrobial and antiviral material, an antimicrobial and antiviral composition, a method of producing the same, and a dispersion of the antimicrobial and antiviral composition, which are capable of exhibiting excellent antimicrobial and antiviral properties for a long time through various uses. Another object of the present invention to provide a coating agent containing the antimicrobial and antiviral composition, an antimicrobial and antiviral film, and an antimicrobial and antiviral article that are capable of exhibiting excellent antimicrobial and antiviral properties for a long time.

Means for Solving the Problems

[0010]

The inventors have found that it is important to coat cuprous oxide particles with a specific amount of silica in order to stabilize cuprous oxide particles exhibiting excellent antimicrobial and antiviral properties without being oxidized to copper (II) oxide in the atmosphere. In other words, the inventors have found that the presence of a specific amount of silica-coating layer can prevent cuprous oxide from being oxidized to copper (II) oxide and maintain the excellent antimicrobial and antiviral properties of the cuprous oxide for a long time. The inventors have also found that combining with a photocatalytic material can almost permanently sustain the antimicrobial and antiviral effect because copper (II) oxide which has lost antimicrobial and antiviral performance since once oxidized from cuprous oxide, is reduced to cuprous oxide by the reduction action of a photocatalyst under light irradiation.

Specifically, the present invention is as follows.

[0011]

[1] An antimicrobial and antiviral material comprising cuprous oxide particles and a silica-coating layer on at least one part of the surface of the cuprous oxide particles, in which the content of the silica-coating layer is 5 to 20 parts by mass based on 100 parts by mass of the cuprous oxide particles, and the BET specific surface area of the cuprous oxide particles is 5 to 100 m²/g.

[2] An antimicrobial and antiviral composition comprising the antimicrobial and antiviral material according to [1].

[3] The antimicrobial and antiviral composition according to [2] further includes a photocatalytic material.

[4] In the antimicrobial and antiviral composition according to [3], the content of the photocatalytic . material is 70 to 99.9% by mass based on the total amount of the antimicrobial and antiviral material and the photocatalytic material.

[5] The antimicrobial and antiviral composition according to [3] or [4] , the photocatalytic material includes at least one selected from titanium oxide and tungsten oxide.

[6] The antimicrobial and antiviral composition according to [3] or [4] , the photocatalytic material is a visible light responsive photocatalyst in which a substrate containing at least one kind selected from titanium oxide and tungsten oxide is modified with at least one selected from a copper (II) ion and an iron (III) ion .

[7] The antimicrobial and antiviral composition according to [6] , the substrate contains at least one kind selected from titanium oxide doped with at least any one of transition metal and non-metal and tungsten oxide doped with at least any one of transition metal and non-metal.

[8] The antimicrobial and antiviral composition according to any one of [2] to [7], wherein the antimicrobial and antiviral material has an L^* value of 50 Or more, an a^* value of 8 or less, a b^* value of 20 or more in the L^*a^*b^* color system according to JIS Z8701.

[0012]

[9] A dispersion of the antimicrobial and antiviral composition, comprising 1 to 30% by mass of the antimicrobial and antiviral composition according to any one of [2] to [8], 40 to 98.98% by mass of a non-aqueous organic solvent, and 0.01 to 10% by mass of a basic substance being soluble in the non-aqueous organic solvent.

[10] The dispersion of the antimicrobial and antiviral composition according to [9] further includes 0.01 to 20% by mass of a surfactant soluble in the non-aqueous organic solvent.

[0013]

[11] A coating agent containing the antimicrobial and antiviral composition, comprising the dispersion of the antimicrobial and antiviral composition according to [9] or [10], and a binder component being curable under an environment of 10 to 120 °C. [12] An antimicrobial and antiviral film which the coating agent containing the antimicrobial and antiviral composition according to [11] is applied and then cured.

[13] An antimicrobial and antiviral article includes the antimicrobial and antiviral film according to [12] on at least one part of the outermost surface.

[0014]

[14] A method of producing the antimicrobial and antiviral material according to [1] includes the steps of:

(1) adding a basic substance, a particle growth inhibitor, and a reducing agent in an aqueous copper (II) compound solution to synthesize cuprous oxide particles;

(2) mixing the cuprous oxide particles with a hydrolyzable silica source in a solvent and hydrolyzing the silica source to coat the cuprous oxide particles with silica so that the content of silica is 5 to 20 parts by mass based on 100 parts by mass of the cuprous oxide particles; and

(3) separating a solid content and then pulverizing the separated solid content.

Effects of the Invention

[0015]

The present invention can provide an antimicrobial and antiviral material, an antimicrobial and antiviral composition, a method of producing the same, and a dispersion of the antimicrobial and antiviral composition, which are capable of exhibiting excellent antimicrobial and antiviral properties for a long time through various uses. The present invention can also provide a coating agent containing the antimicrobial and antiviral composition, an antimicrobial and antiviral film, and an antimicrobial and antiviral article which are capable of exhibiting excellent antimicrobial and antiviral properties for a long time.

For example, applying a coating agent containing the antimicrobial and antiviral composition of the present invention to an article or a part thereof touched by an unspecified number of people can be expected to decrease the risk of the spread of bacteria and viruses from one person to another through the surface of the article.

Brief Description of the Drawings

[0016]

FIG. 1 shows the TEM image of the cuprous oxide particle obtained in Example 1.

FIG. 2 shows a diagram illustrating the X-ray diffraction pattern of the antimicrobial and antiviral material obtained in Example 1.

FIG 3 shows a diagram illustrating the viral inactivation capacity of the antimicrobial and antiviral composition obtained in Example 5.

Modes for Carrying Out the Invention

[0017]

1. Antimicrobial and antiviral material

The antimicrobial and antiviral material of the present invention includes cuprous oxide particles and a silica-coating layer on at least one part of the surface of the cuprous oxide particles, in which the content of the silica-coating layer is 5 to 20 parts by mass based on 100 parts by mass of the cuprous oxide particles, and the BET specific surface area of the cuprous oxide particles coated with silica is 5 to 100 m²/g.

Cuprous oxide particles have high antimicrobial and antiviral properties but high oxidability and thus hardly maintain the excellent antimicrobial and antiviral properties for a long time. In the present invention, a silica-coating layer is formed on the surface of the cuprous oxide particles to maintain the excellent antimicrobial and antiviral properties of cuprous oxide particles. However, if the silica-coating layer is contained too small, the oxidability of cuprous oxide particles cannot be suppressed. If the silica-coating layer is contained too much, the antimicrobial and antiviral properties of cuprous oxide particles are inhibited. In the present invention, the content of the silica-coating layer is adjusted to 5 to 20 parts by mass based on 100 parts by mass of the cuprous oxide particles to suppress the oxidability of cuprous oxide particles and to achieve excellent antimicrobial and antiviral properties.

The cuprous oxide particles should have at least one part of the surface coated with a silica-coating layer but preferably the entire surface coated with a silica-coating layer.

[0018]

Cuprous oxide particles

The cuprous oxide particles used in the present invention are represented by the chemical formula of CU2O. The shape of the cuprous oxide particles observed with an electron microscope is not limited in particular. However, some of the cuprous oxide particles are spherical, amorphous, and almost-spherical crystals. In the present invention, these shaped crystals may exist alone or may be mixed.

[0019]

Cuprous oxide with a smaller particle diameter displays a higher antimicrobial and antiviral performance. In addition, the color of cuprous oxide is known to be diluted by the quantum size effect when pulverized. In this case, the antimicrobial and antiviral performance is also increased, so that the amount used can be decreased . This leads to the decreased coloration . Thus, cuprous oxide as an antimicrobial and antiviral material can be preferable in a smaller microparticle form. However, cuprous oxide particles with a smaller particle diameter are more easily oxidizes in the atmosphere. Copper (II) oxide is known to be blackish, causing the design of an article coated with copper (II) oxide to be impaired. Copper (II) oxide also degrades the antimicrobial and antiviral performance.

Therefore, for the particle diameter of the cuprous oxide particles, the average primary particle diameter determined from the maximum particle diameter measured with an electron microscope falls within the range of preferably 1 to 400 nm, more preferably 5 to 150 nm, further more preferably 10 to 50 nm.

[0020]

Silica-coating layer

The silica-coating layer coated on the surface of the cuprous oxide particles in the present invention can be formed by attaching a silica source to the surface of the cuprous oxide particles and hydrolyzing the silica source. The silica source is not limited in particular as long as being able to form silica by . hydrolyzation . The example of the silica source includes tetraethoxysilane, tetramethoxysilane, and silicon

tetrachloride. Among them, tetraethoxysilane and

tetramethoxysilane are more preferable, and tetraethoxysilane (hereinafter sometimes referred to as "TEOS") is the most preferable in consideration of the usability, the price, and the like.

The silica-coating layer of the present invention is preferably formed of an amorphous silica film. The thickness of the silica film preferably falls within the range of 1 to 20 nra, more preferably 3 to 15 nm, further more preferably 5 to 10 nm.

The silica-coating layer may contain substances other than silica as long as the effect of the present invention is not impeded However, the content of the silica component in the silica-coating layer is preferably 90% by mass or more, more preferably 95% by mass or more, further more preferably 99% by mass or more, most preferably 99.9% by mass or more.

[0021]

The content of the silica-coating layer is 5 to 20 parts by mass based on 100 parts by mass of the cuprous oxide particles. If the content is less than 5 parts by mass, the antioxidant effect is insufficient. On the other hand, if the content is more than 20 parts by mass, the antimicrobial and antiviral performance is degraded. The content of the surfactant is preferably 6.0 to 15% by mass, more preferably 7.0 to 14% by mass, further more preferably 7.0 to 13 parts by mass, most preferably 8.0 to 12 parts by mass .

[0022]

The cuprous oxide particles (antimicrobial and antiviral material) coated with silica has a BET specific surface area of 5 to 100 m²/g, preferably 10 to 50 m²/g, more preferably 13 to 40 m²/g, which is calculated by a nitrogen adsorption method (BET method) . The cuprous oxide particles with a BET specific surface area of 5 to 100 m²/g can exhibit high antimicrobial and antiviral properties. However, the cuprous oxide particles with a BET specific surface area of more than 100 m²/g, the particles hardly synthesized and collected. This makes the cuprous oxide particles hardly handleable. On the other hand, there is the following problem. The cuprous oxide particles with a BET specific surface area of less than 5 m²/g have a few contact points with microbes or viruses to decrease the antimicrobial and antiviral effect. Meanwhile, the obtained cuprous oxide particles become dark orange brown under the influence of the self color of cuprous oxide. If these particles are used for an antimicrobial and antiviral coating agent, the design of an article coated with this agent is impaired.

To adjust the BET specific surface area to fall within the above-mentioned range, the crushing energy is weakened in the step of pulverizing cuprous oxide particles coated with silica, the coating amount of silica is adjusted to fall within the above-mentioned range, the BET specific surface area of the cuprous oxide particles themselves as the base is adjusted to fall within or beyond the above-mentioned range (the BET specific surface area typically decreases due to the coating) , and the like.

[0023]

The antimicrobial and antiviral material has preferably an L^* value of 50 or more, an a^* value of 8 or less, a b^* value of 20 or more in the L^*a^*b^* color system according to JIS Z8701. Compared with a commercially available cuprous oxide, the antimicrobial and antiviral material of the present invention has a lager L^* value, a smaller a^* value, and a larger b^* value and thus is brighter, less reddish, and more yellowish to provide a superior design.

The L^*a^*b^* color system is used to represent an object color, in which L^* represents the brightness, and a^* and b^* represent the hue and the intensity. The larger L^* value represents more brightness. The a^* and b^* values indicate the color direction. Specifically, a^* indicates the red direction, -a^* indicates the green direction, b^* indicates the yellow . direction, and - b^* indicates the blue direction. The intensity (c^*) is represented by the following expression: ( (a^*) ²+ (b^*) ²) ^1/2

[0024]

2. Method of producing antimicrobial and antiviral material

The antimicrobial and antiviral material of the present invention can be produced by the following steps of:

(2) mixing the cuprous oxide particles with a hydrolyzable silica source in a solvent and hydrolyzing silica source to coat the cuprous oxide particles with silica so that the content of silica is 5 to 20 parts by mass based on 100 parts by mass of the cuprous oxide particles; and

Each step will be explained below.

[0025]

(I) Step of synthesizing cuprous oxide particles

The water soluble copper (II) compound includes copper (II) sulfate, copper (II) chloride, copper (II) nitrate, copper (II) acetate, and copper (II) hydroxide. Copper (II) sulfate is preferable. The concentration of a copper (II) compound in an aqueous copper solution to be used for the synthesis is preferably 0.05 to 1 mol/L, more preferably 0.1 to 0.5 mol/L in terms of copper

(II) ions.

The concentration of the copper (II) compound of 0.05 mol/L or less is not economical in view of large scale production. The concentration of the copper (II) compound of 1 mol/L or more increases the concentration of copper ions too much in the solution to generate an adverse impact on the synthesis of the cuprous oxide particles.

[0026]

The basic substance may be an organic or an inorganic substance, including sodium hydroxide, potassium hydroxide, lithium hydroxide, ammonia, triethylamine , and

tetrabutylammonium hydroxide . Among these, sodium hydroxide and tetrabutylammonium hydroxide are preferable. The additive amount of the basic substance is preferably 0.5 to 5 times, more preferably 1 to 3 times the mole number of copper (II) ions.

The additive amount of the basic substance of 0.5 times or less the mole number of copper (II) ions is not preferable because basic environment for sufficiently reducing copper (II) to copper (I) can not be created. The additive amount of the basic substance of 5 times or more the mole number of copper (II) ions generates an adverse impact on the deposition of the copper (I) oxide because the extra hydroxyl groups coordinates with copper (II) ions.

[0027]

The particle growth inhibitor includes glucose, PVP, PVA, gelatin, and amino acid. Among these, glucose is preferable. The additive amount of the particle growth inhibitor is preferably 0.1 to 5 times, more preferably 0.3 to 3 times the mole number of the copper (II) ions.

The additive amount of the particle growth inhibitor of 0.1 times or less the mole number of the copper (II) ions has no inhibiting effect on particle growth. The additive amount of the particle growth inhibitor of 5 times or more the mole number of the copper (II) ions is not economical in view of the cost performance . [0028]

The reducing agent includes aqueous solutions of hydroxylamine sulfate, hydroxylamine nitrate, sodium sulfite, sodium hydrogen sulfite, sodium dithionite, hydrazine sulfate, hydrazine, and sodium phosphite. Among these, an aqueous hydrazine solution is preferable. The additive amount of the reducing agent is preferably 0.1 to 1 times, more preferably 0.2 to 0.5 times the mole number of the copper (II) ion.

The additive amount of the reducing agent of 0.1 times or less cannot sufficiently reduce copper (II) ions to the copper

(1) oxide. The additive amount of the reducing agent of 1 time or more reduces copper (II) ions to metallic copper due to too much amount of the reducing agent.

[0029]

In the conditions for the synthesis of the cuprous oxide particles, the temperature is preferably 10 to 90 °C, more preferably 30 to 60 °C.

The temperature of 10 °C or less decreases the reaction rate, which is not preferable in view of the synthesis efficiency. The temperature of 90 °C or more increases the heat supply, which is not preferable in view of the cost. The reaction time for the synthesis of the cuprous oxide particles is preferably about 0.5 to 5 minutes. If the reaction time is less than 0.5 minutes, copper (II) ions cannot be completely reduced. The reaction time of 5 minutes or more is not required because it is not preferable in view of the cost. Cuprous oxide particles coated with synthesized silica can be filtered through a membrane filter.

[0030]

(2) Step of coating cuprous oxide particles with silica-coating layer In this step, the obtained cuprous oxide particles are mixed with a hydrolyzable -silica source in a solvent, and the silica source is hydrolyzed to coat the cuprous oxide particles with silica so that the content of the silica-coating layer is 5 to 20 parts by mass based on 100 parts by mass of the cuprous oxide particles.

In this method, the silica-coating layer is an amorphous silica film formed by the hydrolyzation of the silica source. The silica source includes the above-mentioned silica source ( tetraethoxysilane etc.). The solvent is not limited in particular, preferably including alcohols. In particular, ethanol is more preferable.

Before cuprous oxide particles are mixed with a silica source, a dispersion of cuprous oxide is preferably prepared. The dispersion of cuprous oxide can be obtained by adding and dispersing the cuprous oxide particles obtained in the step (1) and optionally a dispersant in a solvent such as ethanol with a ball mill.

Preferably, in the hydrolyzation process , the silica source is added to a dispersion of cuprous oxide and stirred for 2 hours, aqueous ammonia is added, and the silica source is hydrolyzed. During the hydrolyzation, a catalyst such as hydrochloric acids can be used.

The entire added amount of the silica source is set so that the content of the silica-coating layer is 5 to 20 parts by mass based on 100 parts by mass of the cuprous oxide particles in the antimicrobial and antiviral material finally obtained after the hydrolyzation. The entire added amount of such a silica source depends on a silica source, a catalyst, and the like to be used but are typically about 5 to 35 parts by mass based on 100 parts by mass of the cuprous oxide particles (in terms of silica) . The hydrolyzation time is typically about 9 to 15 hours.

[0031]

(3) Step of pulverization

After the step (2) , the solid content is dried, separated, and then pulverized to obtain the antimicrobial and antiviral material of the present invention.

[0032]

Filtration with a membrane filter can be adopted to separate the solid, content. The separated solid content is dried at 50 to 80 °C as required before pulverized. For pulverization, pulverizers such as a ball mill, a mixer, and a pot mill; a mortar and a pestle; and the like are used. Preferably, the

pulverization means exemplified herein easily adjust the crushing energy small so as to easily adjust the BET specific surface area of the antimicrobial and antiviral material to fall within the range of 5 to 100 m²/g. The fragment of the silica may be mixed during various pulverizations.

[0033]

3. Antimicrobial and antiviral composition

The antimicrobial and antiviral composition of the present invention contains the above-mentioned antimicrobial and antiviral material of the present invention. Such an

antimicrobial and antiviral composition preferably contains a photocatalytic material in addition to the antimicrobial and antiviral material. Containing a photocatalytic material can reduce copper (II) oxide, which has been changed from copper (I) oxide and then has lost the antimicrobial and antiviral performance, to cuprous oxide (copper (I) oxide) under light irradiation. As a result, the antimicrobial and antiviral performance can be sustained almost permanently.

[0034]

Photocatalytic material

The photocatalytic material should be able to reduce copper

(II) oxide to copper (I) oxide under light irradiation, preferably containing a photocatalyst as a main component. The "main component" means that a photocatalyst is contained in a content of 60% by mass or more in a photocatalytic material.

The photocatalyst includes compound semiconductors such as metal oxide and metal oxynitride. Among these, titanium oxide or tungsten oxide is preferable, and titanium oxide is particularly preferable from the viewpoint of the versatility.

[0035]

Titanium oxide is known to have crystal structures of rutile, anatase, and brookite but can be applied without particular limitation. The inventors understand that the rutile type has relatively high antimicrobial and antiviral performance. The rutile type has a large true specific gravity and thus hardly dispersed in liquid, so that a transparent coating agent is hardly obtained. It is important from the practical viewpoint to use the anatase type or the brookite type for a coating agent with high transparency even though the anatase type and the brookite type have antimicrobial and antiviral performance is slightly inferior to the rutile type. Therefore, the crystal structure of titanium oxide may be selected depending on the productivity and the use.

On the assumption of the use in a room, the photocatalytic material is preferably a visible light responsive photocatalyst.

[0036]

The photocatalytic material is more preferably a visible light responsive photocatalyst in which the surface of a substrate containing at least one kind selected from titanium oxide and tungsten oxide is modified with at least one selected from a copper

(II) ion and an iron (III) ion. The substrate of the visible light responsive photocatalyst preferably contains at least one kind selected from titanium oxide doped with at least any one of transition metal and non-metal; and tungsten oxide doped with at least any one of transition metal and non-metal from the viewpoint of the increase in the amount of light absorption.

[0037]

Titanium oxide as the visible light responsive

photocatalyst is not limited in particular. For example, monocrystalline titanium oxides each with the crystal structure of anatase, rutile, or brookite and each with two or more of these crystal structures being combined can be used. Tungsten oxide as the visible light responsive photocatalyst is not limited in particular. For example, tungsten oxides each with a triclinic crystal structure, a monoclinic crystal structure, and a tetragonal crystal structure can be used.

The copper (II) ion and iron (III) ion as the visible light responsive photocatalyst are not particularly limited as long as modified with a photocatalyst to improve the photocatalytic activity under visible light irradiation. For example, the copper (II) ion and iron (III) ion modified with a photocatalyst include oxides, hydroxides, chlorides, nitrates, sulfates, and acetates, or organic complexes of the copper (II) ion and iron

(III) ion, respectively. Among these, oxides and hydroxides are preferable.

Transition metal and non-metal as the visible light responsive photocatalyst are not particularly limited as long as doped with titanium oxide to produce an impurity level so as to increase the absorption of visible light. For example, the transition metal includes vanadium, chromium, iron, copper, ruthenium, rhodium, tungsten, gallium, and indium. The non-metal includes carbon, nitrogen, and sulfur. In a titanium oxide or a tungsten oxide crystal, a plurality of transition metals or a transition metal and a non-metal can be codoped to maintain the charge balance.

[0038]

As these catalysts, the copper (II) ion-modified titanium oxide is exemplified in the paragraphs 0029 to 0032 in JP 2011 079713 A. The copper (II) ion-modified tungsten oxide is exemplified in the paragraphs 0028 to 0031 in JP 2009-226299 A. The exemplary titanium oxide codoped with copper (II)

ion-modified tungsten and gallium is exemplified in the paragraphs 0013 to 0021 in JP 2011 031139 A.

[0039]

The photocatalytic material preferably has a high crystallinity, specifically a crystallinity of 60% or more. The high crystallinity can prevent electrons and positive holes caused due to light excitation from binding. This increases the probability that copper (II) receives electrons, so that the reducibility can be improved.

The photocatalytic material preferably has a small average particle size, specifically 500 nm or less, more preferably 300 nm or less, further more preferably 100 nm or less. The small average particle size can decrease the time required for electrons caused by light excitation to reach the surface of the photocatalytic material. This increases the probability that copper (II) receives electrons, so that the reducibility can be improved.

[0040]

The proportion of the photocatalytic material in the total of the photocatalytic material and the antimicrobial and antiviral material is preferably 70 to 99.9% by mass, more preferably 80 to 99% by mass, further more preferably 90 to 98% by mass from the viewpoint of the durability of the antimicrobial and antiviral performance based on reducing ability and the viewpoint of the balance in the initial antimicrobial and antiviral performance.

[0041]

The antimicrobial and antiviral composition may contain a solid content in addition to the antimicrobial and antiviral material and the photocatalytic material as long as the effect of the present invention is not impeded. The total of the antimicrobial and antiviral material and the photocatalytic material in the antimicrobial and antiviral composition is preferably 90% by mass or more, more preferably 95% by mass or more, further more preferably 99.9% by mass or more in terms of solid content. When the antimicrobial and antiviral composition does not contain the photocatalytic material, the proportion of the antimicrobial and antiviral material in the antimicrobial and antiviral composition is preferably 90% by mass or more, more preferably 95% by mass or more, further more preferably 99.9% by mass or more in terms of solid content.

[0042]

The antimicrobial and antiviral composition containing the photocatalytic material and the antimicrobial and antiviral material can be obtained by mixing the antimicrobial and antiviral material of the present invention or the dispersion thereof in a dispersion of the above-mentioned photocatalytic material.

[0043]

4. Dispersion of the antimicrobial and antiviral composition

The dispersion of the antimicrobial and antiviral composition of the present invention (hereinafter sometimes referred to as "the dispersion of the present invention") contains 1 to 30% by mass of the above-mentioned antimicrobial and antiviral composition of the present invention, 40 to 98.98% by mass of a non-aqueous organic solvent, and 0.01 to 10% by mass of a basic substance being soluble in the non-aqueous organic solvent.

[0044]

In the dispersion of the present invention, the content ratio is adjusted as described above, so that the antimicrobial and antiviral composition can be uniformly dispersed and stably preserved.

The antimicrobial and antiviral composition contained in a content of 1% by mass or more can display the antimicrobial and antiviral performance. The antimicrobial and antiviral composition contained in a content of 30% by mass or less can stably preserve the dispersion of the present invention to improve the convenience. The concentration of the antimicrobial and antiviral composition in the dispersion of the antimicrobial and antiviral composition is preferably 2 to 20% by mass, more preferably 3 to 10% by mass.

[0045]

A non-aqueous organic solvent contained in a concentration of 40% by mass or more can stably preserve the antimicrobial and antiviral composition,. The concentration of 98.98% by mass or less can secure the amount of the antimicrobial and antiviral composition to display antimicrobial and antiviral performance. The concentration of the non-aqueous organic solvent is preferably 58 to 97.90% by mass, more preferably 75 to 96.84% by mass.

[0046]

The basic substance soluble in the non-aqueous organic solvent with a concentration of 0.01% by mass or more allows the dispersion of the present invention to be basic, so that the cuprous oxide particles can be prevented from being dissolved. Furthermore, the basic substance with a concentration of 10% by mass or less decreases the residue of a basic substance in a film formed from the dispersion of the present invention, so that the antimicrobial and antiviral performance of the cuprous oxide particles can be maintained. The concentration of the basic substance in the dispersion of the antimicrobial and antiviral composition is preferably 0.05 to 7% by mass, more preferably 0.08 to 5% by mass.

[0047]

The non-aqueous organic solvent is an organic solvent other than water, including ethanol, methanol, 2-propanol, denatured alcohol, methyl ethyl ketone (MEK) , and n-propyl acetate (NPAC) .

The reason for using the non-aqueous organic solvent is because cuprous oxide is easily oxidized to divalent copper in water but hardly oxidized in non-aqueous solvent. Thus, the non-aqueous organic solvent preferably has 0.5% by mass or less of water based on the amount of the non-aqueous solvent.

[0048]

The basic substance soluble in the non-aqueous organic solvent may be an organic or an inorganic substance, including sodium hydroxide, potassium hydroxide, lithium hydroxide, ammonia, triethylamine, and tetrabutylammonium hydroxide. Among these, sodium hydroxide and tetrabutylammonium hydroxide are preferable. The solubility of the basic substance is preferably 0.05 g or more based on 100 g of the non-aqueous organic solvent .

If the solubility of the basic substance is less than 0.05 g based on 100 g of the non-aqueous organic solvent, the dispersion of the present invention cannot be sufficiently maintained in basic environment and thus dissolved due to the acidity when mixed with copper (I) oxide.

[0049]

The dispersion of the present invention preferably further contains a surfactant being soluble in the non-aqueous organic solvent. Containing the surfactant decreases the interparticle agglomeration of the antimicrobial and antiviral composition to provide . steric hindrance, so that the dispersion can be stabilized.

The surfactant is preferably contained in a content of 0.01 to 20% by mass in the dispersion of the antimicrobial and antiviral composition. The content of the surfactant of 0.01% by mass or more improves the dispersibility of the dispersion to prevent the antimicrobial and antiviral composition from precipitating . The content of the surfactant of 20% by mass or less decreases the amount of the surfactant remaining in a film formed from the dispersion, so that the antimicrobial and antiviral performance of the film can be prevented from degrading. The content of the surfactant is preferably 0.05 to 15% by mass, more preferably 0.08 to 10% by mass.

[0050]

The surfactant soluble in the non-aqueous organic solvent is preferably a non-ionic surfactant including esters such as glycerine fatty acid ester, sorbitan fatty acid ester, and saccharose fatty acid ester and ethers such as fatty alcohol ethoxylate, polyoxyethylene alkylphenyl ether, octylphenoxy polyethoxyethanol (Triton™ X-100 ) , and alkyl glycoside. Among these, octylphenoxy polyethoxyethanol is preferable.

[0051]

5. Coating agent containing the antimicrobial and antiviral composition, Antimicrobial and antiviral film, and Antimicrobial and antiviral article

The coating agent containing the antimicrobial and antiviral composition of the present invention comprises the dispersion of the antimicrobial and antiviral composition according a binder component being curable under an environment of 10 to 120 °C. As the binder component, an inorganic binder or an organic binder may be used. In view of the degradation of a binder by a photocatalytic material, an inorganic binder is preferable. The type of the binder is not particularly limited, for example, including a silica binder, a zirconia binder, an alumina binder, and a titania binder, and a combination thereof. Among these, a silica binder or a zirconia binder is preferable.

[0052]

The content of the binder is preferably 0.5 to 10% by mass, more preferably 1 to 8% by mass in the coating agent containing the antimicrobial and antiviral composition. This range of the content binder can stably disperse the coating agent, easily uniform a coated film formed by applying the coating agent to a coated body and curing the coating agent, and improve the coating adhesion to the coated body.

[0053] The antimicrobial and antiviral film of the present invention is formed by applying and curing the antimicrobial and antiviral composition-containing coating agent of the present invention. The coated body to which the antimicrobial and antiviral composition-containing coating agent of the present invention is applied includes metal, ceramics, glass, fiber, nonwoven fabric, film, plastic, rubber, paper, and wood. The surface of the coated body may be subjected to an easy adhesion process or the like. The application method is not limited in particular. As the application method, a spin coating method, a dip coating method, a spray coating method, or. the like can be applied.

[0054]

The curing temperature after the application of the coating agent depends on a binder component to be used but is preferably about 20 to 80 °C. The thickness of the antimicrobial and antiviral film of the present invention obtained by the curing is preferably 0.05 to 1 ym, more preferably 0.1 to 0.5 ym.

If the film thickness is 0.05 μπι or less, the amount of the antimicrobial and antiviral composition is small, so that the material cannot have sufficient antimicrobial and antiviral performance. If the film thickness is 1 μπι or more, the amount of the antimicrobial and antiviral composition is large, so that the material can have sufficient antimicrobial and antiviral performance but decrease the hardness and the durability of the film.

[0055]

The antimicrobial and antiviral article of the present invention has the antimicrobial and antiviral film of the present invention on at least one part of the outermost surface (for W example, to be touched by people) , including articles such as construction materials, sanitary materials, and antifouling materials.

Examples

[0056]

The present invention will be explained specifically in reference to the examples below.

The examples and the comparative examples were measured and evaluated as follows.

[0057]

XRD measurement

The crystal peak attribution of the cuprous oxide particles of the antimicrobial and antiviral composition obtained in each of the examples and the comparative examples was determined by XRD measurement. In the XRD measurement, a Cu-Kal line was used as a copper target, the tube voltage was 45 kV, the tube current was 40 mA, the measurement range was 2Θ = 20 to 80 deg, the sampling width was 0.0167 deg, and the scan rate was 1.1 deg/min . X ' PertPRO available from Panalytical B.V. was used for this measurement. BET specific surface area

The BET specific surface area of the antimicrobial and antiviral materials obtained in each of the examples and the comparative examples was measured with an automatic BET specific surface area analyzer "Macsorb, HM model-1208" available from Mountech Co., Ltd.

Mass of silica-coating layer

The mass of the silica-coating layer of the antimicrobial and antiviral material obtained in each of the examples and the comparative examples was measured by the following procedure. Cuprous oxide particles (0.1 g) coated with silica, Na₂C03 (2 g) , W and H3BO3 (1 g) were added in a platinum crucible and subjected to alkali fusion. After allowed to cool, the fused mixture was mixed with a nitric acid solution to obtain a mixture solution. The obtained mixture solution was measured with an ICP emission spectrophotometer (product name: ICPS-7500 available from Shimadzu Corporation) . The calibration curve was constructed by using 10 ppm of silicon standard solution. The amount of silicon of the cuprous oxide particles coated with silica was calculated from the calibration curve. The mass of the silica was calculated from the amount of the silicon and then defined as the mass of the silica-coating layer.

Color value

The color value (L^*a^*b^* value) was measured with a spectral colorimeter "CM-3700d" available from KONICA MINOLTA OPTICS, INC. Environmental test

The environmental test was conducted with a compact environmental test chamber "SH-241" available from ESPEC CORP. The antimicrobial and antiviral composition was maintained at a temperature of 50 °C and a humidity of 98% for 1 week.

[0058]

Evaluation of viral inactivation capacity: Measurement of LOG(N/No)

The viral inactivation capacity was evaluated by the following procedure in a model experiment using bacteriophages. The method using the inactivation capacity for bacteriophages as a model of viral inactivation capacity is described in, for example, Appl. Microbiol Biotechnol . , 79, pp. 127 to 133, 2008 and known for obtaining a reliable result.

A filter paper was placed on the bottom of a deep Petri dish, and a small amount of sterilized water was added to the Petri dish. A grass platform with a thickness of about.5 mm was placed on the filter paper. On the grass platform, glass plates (50 mm ^χ 50 mm x 1 mm) were placed. On these glass plates, the antimicrobial and antiviral materials of Examples 1 to 4 and the samples of Comparative Examples 1 to 4 were applied so that the solid contents were 0.06 mg / 25 cm², and the dispersions of the antimicrobial and antiviral composition of Examples 5 to 10 and the samples of Comparative Examples 5 to 11 were applied so that the solid contents were 1.5 mg / 25 cm². 100 μΐ, of suspension with a predetermined concentration of previously naturalized QB phages

(NBRC20012) were added dropwise to each of the glass plates, and then a PET (polyethylene terephthalate) OHP film was placed over each of the glass plates in order to make the sample surface contact with the phages. The deep culture plate was covered with a lid to prepare a measurement unit. A plurality of measurement units were prepared per sample.

A 15 white fluorescent lamp (full white fluorescent lamp, FL15N, available from Panasonic Corporation) equipped with a UV-cutting filter (N-113, available from Nitto Jushi Kogyo Co., Ltd.) was used as a light source. The measurement units were placed under the light source at a position where the illuminance

(measured with an illuminometer, IM-5, available from TOPCON . CORPORATION) was 800 Lux. After the elapse of a predetermined time, the phage concentration of each sample present on the glass plate was measured.

[0059]

The phage concentration was determined by the following procedure. ^' The sample present on the glass plate was recovered with 10 mL of a phage recovery liquid (SM Buffer) and shaken with a shaker for 10 minutes. This phage collecting liquid was appropriately diluted, mixed with a culture solution (Οϋεοο > 1.0, lxl0⁸CFU/mL) withE. coli (NBRC13965) being separately cultured, and then the mixture was left in a constant temperature room of 37 °C to infect the phages with E. coli. The resultant liquid was added to an agar medium and cultured at 37 °C for 15 hours. Then, the number of phage plaques was visually counted. The phage concentration N was determined by multiplying the counted number of the plaques by the dilution rate of the phage-recovered liquid.

From the initial phage concentration No and the phage concentration N after the elapse of a predetermined time, the relative phage concentration (LOG(N/No)) was determined.

The viral inactivation capacities evaluated under various conditions are shown in Tables 1 to 3.

[0060]

Example 1

3000 mL of distilled water was heated to 50 °C, and then 149.8 g of copper (II) sulfate pentahydrate was added while being stirred to be completely dissolved. Subsequently, 200 g of 1.5 mol/L of aqueous glucose solution was added, and then 720 g of 2 mol/L of aqueous sodium hydroxide solution and 120 mL of 2 mol/L of aqueous hydrazine hydrate solution were added together. After the mixture was vigorously stirred for 1 minute, the stirred mixture was filtrated with a 0.3 μπι membrane filter, and then the filtrated substance was washed with 3000 mL of distilled water to collect the solid content. After dried at 60 °C for 3 hours, the solid content was pulverized with an agate mortar to obtain cuprous oxide particles. The BET specific surface area of the obtained cuprous oxide particles was 29.20 m²/g, which was measured by the nitrogen adsorption method. 5 g of the obtained cuprous oxide particles were dispersed in 60 mL of ethanol solvent to obtain the suspension 1. 1.827 g of TEOS with a purity of 95% was added to 20 mL of ethanol to obtain the solution 2 (which is equivalent to 10 parts by mass of silica in terms of the entire added amount based on 100 parts by mass of the cuprous oxide particles) . The solution 2 was mixed with the suspension 1, and 10 mL of pure water were added to the mixture and stirred for 2 hours. 10 mL of 5% of ammonia aqueous solution was added to the mixture and stirred for 12 hours. The mixture was filtrated with a 0.3 μπι membrane filter . The filtrated substance was washed with 100 mL distilled water and then with 100 mL of ethanol. The collected substance was dried at 60 °C for 3h and pulverized with an agate mortar to obtain the antimicrobial and antiviral material (cuprous oxide particles coated with silica) A. The mass and the BET specific surface area of the silica-coating layer of the obtained cuprous oxide particles coated with silica are shown in Table 1.

FIG. 1 shows the TEM image of the antimicrobial and antiviral material (cuprous oxide particle coated with silica) A and FIG. 1 demonstrates that a silica layer with a thickness of about 5.6 nm was formed. FIG. 2 shows the X-ray diffraction pattern of the antimicrobial and antiviral material (cuprous oxide particles coated with silica) A. In FIG. 2, only the peaks of cuprous oxide can be observed. Therefore, an amorphous silica-coating layer is clearly formed.

[0061]

Example 2

Cuprous oxide particles were prepared in the same manner as Example 1. 5 g of the obtained cuprous oxide particles were dispersed in 60 mL of ethanol solvent to obtain the suspension 1. 2.742 g of TEOS with a purity of 95% was added to 20 mL of ethanol to obtain the solution 2 (which is equivalent to 15 parts by mass of silica in terms of the entire added amount based on 100 parts by mass of the cuprous oxide particles) . The solution 2 was mixed with the suspension 1, and 10 mL of pure water were added to the mixture. Then, the antimicrobial and antiviral material (cuprous oxide particles coated with silica) B was obtained in the same manner as Example 1. The mass and the BET specific surface area of the silica-coating layer of the obtained cuprous oxide particles coated with silica are shown in Table 1.

[0062]

Example 3

Cuprous oxide particles were prepared in the same manner as Example 1. 5 g of the obtained cuprous oxide particles were dispersed in 60 mL of ethanol solvent to obtain the suspension 1. 3.654 g of TEOS with a purity of 95% was added to 20 mL of ethanol to obtain the solution 2 (which is equivalent to 20 parts by mass of silica in terms of the entire added amount based on 100 parts by mass of the cuprous oxide particles) . The solution 2 was mixed with the suspension 1, and 10 mL of pure water were added to the mixture. Then, the antimicrobial and antiviral material (cuprous oxide particles coated with silica) C was obtained in the same manner as Example 1. The mass and the BET specific surface area of the silica-coating layer of the obtained cuprous oxide particles coated with silica are shown in Table 1.

[0063]

Example 4

Cuprous oxide particles were prepared in the same manner as Example 1. 5 g of the obtained cuprous oxide particles were dispersed in 60 mL of ethanol solvent to obtain the suspension 1. 4.59 g of TEOS with a purity of 95% was added to 20 mL of ethanol to obtain the solution 2 (which is equivalent to 25 parts by mass of silica in terms of the entire added amount based on 100 parts by mass of the cuprous oxide particles) . The solution 2 was mixed with the suspension 1, and 10 mL of pure water were added to the mixture. Then, the antimicrobial and antiviral material

(cuprous oxide particles coated with silica) D was obtained in the same manner as Example 1. The mass and the BET specific surface area of the silica-coating layer of the obtained cuprous oxide particles coated with silica are shown in Table 1.

[0064]

Comparative Example 1

Cuprous oxide particles were prepared in the same manner as Example 1. The BET specific surface area of the obtained cuprous oxide particles is shown in Table 1.

[0065]

Comparative Example 2

Cuprous oxide particles were prepared in the same manner as Example 1. 5 g of the obtained cuprous oxide particles were dispersed in 60 mL of ethanol solvent to obtain the suspension 1. 0.918 g of TEOS with a purity of 95% was added, to 20 mL of ethanol to obtain the solution 2 (which is equivalent to 5 parts by mass of silica in terms of the entire added amount based on 100 parts by mass of the cuprous oxide particles) . The solution 2 was mixed with the suspension 1, and 10 mL of pure water were added to the mixture. Then, the antimicrobial and antiviral material (cuprous oxide particles coated with silica) E was obtained in the same manner as Example 1. The mass and the BET specific surface area of the silica-coating layer of the obtained cuprous oxide particles coated with silica are shown in Table 1.

[0066] Comparative Example 3

Cuprous oxide particles were prepared in the same manner as Example 1. 5 g of the obtained cuprous oxide particles were dispersed in 60 mL of ethanol solvent to obtain the suspension 1. 6.40 g of TEOS with a purity of 95% was added to 20 mL of ethanol to obtain the solution 2 (which is equivalent to 35 parts by mass of silica in terms^' of the entire added amount based on 100 parts by mass of the cuprous oxide particles) . The solution 2 was mixed with the suspension 1, and 10 mL of pure water were added to the mixture. Then, the antimicrobial and antiviral material

(cuprous oxide particles coated with silica) F was obtained in the same manner as Example 1. The mass and the BET specific surface area of the silica-coating layer of the obtained cuprous oxide particles coated with silica are shown in Table 1.

[0067]

Table 1

[0068]

The results before the environmental test show that the viral inactivation capacity decreases with the increased coating amount of silica.

The results before and after the environmental test show that Examples 1 to 4 did not have their viral inactivation capacity and their color values changed before and after maintained in a environmental test chamber. This is considered to be because the contained silica-coating layer enables the antioxidation . In particular, any of Examples 1 to 3 has a high viral inactivation capacity before and after the environmental test.

On the other hand, Comparative Examples 1 and 2 have a substantially decreased viral inactivation capacity, a decreased color intensity, and a black color after the environment test. This may occur because the content of the silica-coating layer is small, not enabling the antioxidation. Comparative Example 3 has poor viral inactivation capacity even before the environmental test because the silica-coating layer is contained too much.

[0069]

Example 5 ^

Anatase titanium oxide (available from Showa Titanium Co. , Ltd., average particle size: 15 nm) was suspended in 2-propyl alcohol (hereafter referred to as "IPA") to prepare a dispersion element with a solid content concentration of 5% by mass. After 2 parts by mass of Triton™ X-100 (octylphenoxy polyethoxyethanol available from KANTO CHEMICAL CO., INC.) based on 100 parts by mass of the titanium oxide was added, 2 parts by mass of tetrabutylammonium hydroxide based on 100 parts by mass of the titanium oxide (40% by mass of aqueous tetrabutylammonium hydroxide solution (available KANTO CHEMICAL CO., INC.)) was added.

Then, the suspension was dispersed with a bead mill by using a 0.1 mm-sized medium to obtain a dispersion (hereafter referred to as "dispersion element G") . The dispersion element G and the antimicrobial and antiviral material A obtained in Example 1 were mixed so that the content of antimicrobial and antiviral material A was 4.8 parts by mass (the content of the photocatalytic material was 95.2 parts by mass) based on 100 parts by mass of the total amount of the antimicrobial and antiviral material and the titanium oxide. Then, a dispersion of the antimicrobial and antiviral composition was obtained.

[0070]

The obtained dispersion of the antimicrobial and antiviral composition was applied to a glass plate (50 mm ^χ 50 mm ^χ 1 mm) so that the solid content was 1.5 mg / 25 cm². The solvent on the glass plate was evaporated, and then the viral inactivation capacity was evaluated (the evaluation method is described later) . The result is shown in FIG. 3.

In FIG. 3, "Blank" represents the evaluation result of the viral inactivation capacity of only a glass plate. "Dark place" represents the evaluation result of a glass plate on which the dispersion was applied under a dark condition. "Visible light irradiation" represents the evaluation result of a glass plate on which the dispersion is applied under visible light

irradiation .

The visible light irradiation was conducted in conditions by delivering light from a white fluorescent lamp through an optical filter (N-113 available from Nitto Jushi Kogyo Co. , Ltd. ) cutting a light of 400 nm or less. The light intensity was 800 Lux .

[0071]

As seen in FIG. 3, a glass plate itself did not display the viral inactivation capacity. The glass plate on which the dispersion was applied displayed the viral inactivation capacity even in a dark place. The glass plate on which the dispersion was applied displayed higher viral inactivation capacity under visible light irradiation. Therefore, the antimicrobial and antiviral composition of the present invention clearly exhibits excellent viral inactivation capacity. Furthermore, the antimicrobial and antiviral composition of the present invention used with a photocatalytic material was confirmed to have an effect on the improvement of the viral inactivation capacity under light irradiation in a dark place.

[0072]

Example 6

50 g of brookite titanium oxide (available from Showa Titanium Co., Ltd., average particle size: 10 nm) was suspended in 1000 mL of distilled water, 0.133 g of CuCl₂-2H₂0 (available from KANTO CHEMICAL CO., INC.) was added to support 0.1 parts by mass of copper (II) ions based on 100 parts by mass of the titanium oxide, and then the mixture was heated to 90 °C while being stirred for 1 hour. The heated mixture was washed and dried to obtain the copper (II) ion-modified titanium oxide H. Except for using the copper (II) ion-modified titanium oxide H instead of anatase titanium oxide, a dispersion of the antimicrobial and antiviral composition was obtained in the same manner as Example 5.

[0073]

Example 7

50 g of tungsten oxide (available from Wako Pure Chemical Industries, Ltd.) was suspended in 1000 mL of distilled water, 0.133 g of CuCl₂-2H₂0 (available from KANTO CHEMICAL CO., INC.) was added so as to support 0.1 parts by mass of copper (II) ions based on 100 parts by mass of the titanium oxide, and then the mixture was heated to 90 °C while being stirred for 1 hour. The heated mixture was washed and dried to prepare the copper (II) ion-modified tungsten oxide I. Except for using the copper (II) ion-modified tungsten oxide I instead of anatase titanium oxide, a dispersion of the antimicrobial and antiviral composition was obtained in the same manner as Example 5.

[0074]

Example 8

10 g of titanium oxide (with a crystal structure of rutile, available from TAYCA CORPORATION, average particle size: 15 nm) was suspended in 20 mL of ethanol (available from Wako Pure Chemical Industries, Ltd. ) to prepare a titanium oxide suspension 1 g of tungsten hexachloride (available from Sigma-Aldrich Co. LLC) was dissolved in 10 mL of ethanol to prepare a tungsten solution. 1 g of gallium (III) nitrate monohydrate (available from Sigma-Aldrich Co. LLC) was dissolved in 10 mL of ethanol to prepare a gallium solution. The tungsten solution and the gallium solution were mixed with the titanium oxide suspension so that the molar ratio of tungsten : gallium: titanium was 0.03:0.06:0.91. While the mixture was stirred, the ethanol solvent was evaporated. The obtained powder was heated at 950 °C for 3 hours . As a result, the titanium oxide codoped with tungsten and gallium was obtained. 5 g of the titanium oxide codoped with tungsten and gallium was suspended in 100 g of distilled water, 0.013 g of CuCl₂-2H₂0 (available from KANTO CHEMICAL CO., INC.) was added so as to support 0.1 parts by mass of copper (II) ions based on 100 parts by mass of the titanium oxide codoped with tungsten and gallium, and then the mixture was heated to 90 °C while stirred for 1 hour. The heated mixture was washed and dried to prepare the titanium oxide codoped with copper (II) ion-modified tungsten and gallium J. Except for using the titanium oxide codoped with copper (II) ion-modified tungsten and gallium J instead of anatase titanium oxide, a dispersion of the antimicrobial and antiviral composition was obtained in the same manner as Example 5.

[0075]

Example 9

In Example 5, the dispersion element G and the antimicrobial and antiviral material A obtained in Example 1 were mixed so that the content of antimicrobial and antiviral material. A was 15.0 parts by mass (the content of the photocatalytic material was 85.0 parts by mass) based on 100 parts by mass of the total amount of the antimicrobial and antiviral material and the titanium oxide. Then, a dispersion of the antimicrobial and antiviral composition was obtained.

[0076]

Example 10

In Example 5, the dispersion element G and the antimicrobial and antiviral material A obtained in Example 1 were mixed so that the content of antimicrobial and antiviral material A was 25.0 parts by mass (the content of the photocatalytic material was 75.0 parts by mass) based on 100 parts by mass of the total amount of the antimicrobial and antiviral material and the titanium oxide. Then, a dispersion of the antimicrobial and antiviral composition was obtained.

[0077]

Comparative Example 4 Except for using a commercially available cuprous oxide (product name: "Regular" available from FURUKAWA CHEMICALS CO., LTD. , BET specific surface area: 1 m²/g) , cuprous oxide particles coated with silica were obtained in the same manner as Example 1. The mass and the BET specific surface area of the

silica-coating layer of the obtained cuprous oxide particles coated with silica are shown in Table 2. 1 g of the obtained silica-coating cuprous oxide particles were dispersed in 100 ml of ethanol to obtain a dispersion. The dispersion was applied to a glass plate to form a film coated with cuprous oxide so that the application amount was 24 mg/m².

[0078]

Comparative Example 5

^• The cuprous oxide particles obtained in Comparative Example 1 were left in an environmental test chamber (50 °C, 98%RH) for 7 days and oxidized to copper (II) oxide. The copper (II) oxide and the dispersion element G were mixed so that copper (II) oxide : titanium oxide was 4.8 : 95.2. Then, a dispersion of copper

(II) oxide/titanium oxide was obtained.

[0079]

Comparative Example 6

The cuprous oxide particles obtained in Comparative Example 1 and the dispersion element G were mixed so that cuprous oxide : titanium oxide was 4.8:95.2. Then, a dispersion of copper (I) oxide/titanium oxide was obtained.

[0080]

Comparative Example 7

Except for using the copper (II) ion-modified titanium oxide H used in Example 6 instead of anatase titanium oxide, the dispersion element K of the copper (II) ion-modified titanium oxide H was obtained in the same manner as the preparation process of the dispersion element G in Example 5. The cuprous oxide particles obtained in Comparative Example 1 and the dispersion element K were mixed so that the mass ratio of cuprous oxide particles : copper (II) ion-modified titanium oxide H was 4.8 : 95.2. Then, a dispersion of the copper (I) oxide/copper (II) ion-modified titanium oxide was obtained.

[0081]

Comparative Example 8

Except for using the copper (II) ion-modified tungsten oxide I used in Example 7 instead of anatase titanium oxide, the dispersion element L of the copper (II) ion-modified tungsten oxide I was obtained in the same manner as the preparation process of the dispersion element G in Example 5. The cuprous oxide particles obtained in Comparative Example 1 and the dispersion element L were mixed so that the mass ratio of cuprous oxide particles : copper (II) ion-modified tungsten oxide I was 4.8 : 95.2. Then, a dispersion of copper (I) oxide/copper (II) ion-modified tungsten oxide was obtained.

[0082]

Comparative Example 9

Except for using the titanium oxide codoped with copper (II) ion-modified tungsten and gallium J used in Example 8 instead of anatase titanium oxide, the dispersion element M of the titanium oxide codoped with copper (II) ion-modified tungsten and gallium J was obtained in the same manner as the preparation process of the dispersion element G in Example 5. The. cuprous oxide particles obtained in Comparative Example 1 and the dispersion element M were mixed so that the mass ratio of cuprous oxide particles : titanium oxide codoped with copper (II) ion-modified tungsten and gallium J was 4.8:95.2. Then, a dispersion of copper (I) oxide/titanium oxide codoped with copper (II) ion-modified tungsten and gallium was obtained.

[0083]

Comparative Example 10

Except for using aluminum oxide (available from KANTO CHEMICAL CO., INC., average particle size: 40 μιτι) instead of anatase titanium oxide, the dispersion element N of the aluminum oxide was obtained in the same manner as the preparation process of the dispersion element G in Example 5. The cuprous oxide particles obtained in Comparative Example 1 and the dispersion element N were mixed so that the mass ratio of cuprous oxide particles : aluminum oxide was 4.8:95.2. Then, a dispersion of copper (I) oxide/aluminum oxide was obtained

[0084]

Comparative Example 11

The antimicrobial and antiviral material E obtained in Comparative Example 2 and the dispersion element G were mixed so that the content of antimicrobial and antiviral material E was 4.8 parts by mass (the content of the photocatalytic material was 95.2 parts by mass) based on 100 parts by mass of the total amount of the antimicrobial and antiviral material and the titanium oxide . Then, a dispersion of the antimicrobial and antiviral composition was obtained.

[0085]

Table 2 Table 2

[0086]

Table 2 shows the comparison of the viral inactivation capacity and the color values of the antimicrobial and antiviral material of Example 1 with those of Comparative Example 4. The result clearly shows that the antimicrobial and antiviral material of Example 1 with a large BET specific surface area has a higher activity than that of Comparative Example 4. Therefore, the antimicrobial and antiviral composition of the present invention even with a small coating amount can be expected to have high viral inactivation capacity. The result also shows that the antimicrobial and antiviral material of Example 1 with a large BET specific surface area is brighter and less reddish to provide a superior design.

[0087]

Table 3

Ta le 3

[0088]

Table 3 shows the antiviral performances of the material combined with a photocatalytic material immediately after synthesized and after maintained in an environmental test chamber (50 °C and 98%RH, shaded) under high load environment, respectively.

Examples 5 to 10 are antimicrobial and antiviral compositions with the antimicrobial and antiviral material and a photocatalyst being combined. Comparative Example 5 is an antimicrobial and antiviral composition without the

silica-coating layer but with copper oxide and a photocatalyst being combined. Comparative Examples 6 to 9 are antimicrobial and antiviral compositions without the silica-coating layer but with cuprous oxide and a photocatalyst being combined.

Comparative Example 10 is an antimicrobial and antiviral composition without the silica-coating layer but with cuprous oxide and aluminum oxide having no photocatalytic performance being combined. Comparative Example 11 is an antimicrobial and antiviral composition with a silica-coating layer containing a small amount of silica and with cuprous oxide and a photocatalyst being combined.

[0089]

From the evaluation result immediately after the synthesis, regardless of the presence of the silica-coating layer, Examples 5 to 10 and Comparative Examples 6 to 9 and 11 (antimicrobial and antiviral composition with cuprous oxide and a photocatalyst being combined) have an excellent viral inactivation capacity than Comparative Example 5 (antimicrobial and antiviral composition with copper (II) oxide and a photocatalyst being combined) . Therefore, the composition, cuprous oxide is considered to be required to display viral inactivation capacity in a dark place from the beginning.

From the evaluation result immediately after the synthesis, Examples 5 to 10 (antimicrobial and antiviral compositions with the antimicrobial and antiviral material and a photocatalyst being combined) and Comparative Examples 6 to 9 (antimicrobial and antiviral composition without the silica-coating layer) and Comparative Example 11 (antimicrobial and antiviral composition with a silica-coating layer containing a small amount of silica and with cuprous oxide and a photocatalyst being combined) displayed viral inactivation capacity in a dark place and improved viral inactivation capacity under light irradiation.

Accordingly, any profound difference could not be confirmed among the compositions. On the other hand, the evaluation result after maintained in an environmental test chamber shows that

Comparative Examples 6 to 9 without the silica-coating layer) and Comparative Example 11 with a silica-coating layer containing a small amount of silica can not display high viral inactivation capacity even if combined with a photocatalyst as Examples 5 to 10.

The antimicrobial and antiviral composition of Comparative Example 10 with cuprous oxide and aluminum oxide having no photocatalytic performance being combined displayed viral inactivation capacity in a dark place immediately after the synthesis but could not be confirmed to improve the viral inactivation capacity under light irradiation . Furthermore, the antimicrobial and antiviral composition of Comparative Example 10 decreased the viral inactivation capacity after maintained in an environmental test chamber.

Therefore, as Examples 5 to 10, the antimicrobial and antiviral compositions with the antimicrobial and antiviral material and a photocatalyst being combined was confirmed to maintain high viral inactivation capacity in the light of the resistance to temperature and humidity and the durability.

Claims

1. An antimicrobial and antiviral material comprising cuprous oxide particles and a silica-coating layer on at least one part of the surface of the cuprous oxide particles, wherein the content of the silica-coating layer is 5 to 20 parts by mass based on 100 parts by mass of the cuprous oxide particles, and the BET specific surface area of the cuprous oxide particles coated with silica is 5 to 100 m²/g.

2. An antimicrobial and antiviral composition comprising the antimicrobial and antiviral material according to claim 1.

3. The antimicrobial and antiviral composition according to claim

2 further comprising a photocatalytic material.

4. The antimicrobial and antiviral composition according to claim 3, wherein the content of the photocatalytic material is 70 to 99.9% by mass based on the total amount of the antimicrobial and antiviral material and the photocatalytic material.

5. The antimicrobial and antiviral composition according to claim

3 or 4, wherein the photocatalytic material includes at least one selected from titanium oxide and tungsten oxide.

6. The antimicrobial and antiviral composition according to claim 3 or 4, wherein the photocatalytic material is a visible light responsive photocatalyst in which a substrate containing at least one kind selected from titanium oxide and tungsten oxide is modified with at least one selected from a copper (II) ion and an iron (III) ion.

7. The antimicrobial and antiviral composition according to claim 6, wherein the substrate contains at least one kind selected from titanium oxide doped with at least any one of transition metal and non-metal and tungsten oxide doped with at least any one of transition metal and non-metal.

8. The antimicrobial and antiviral composition according to any one of claims 2 to 7, wherein the antimicrobial and antiviral material has an L^* value of 50 or more, an a^* value of 8 or less, a b^* value of 20 or more in the L^*a^*b^* color system according to JIS Z8701.

9. A dispersion of the antimicrobial and antiviral composition, comprising 1 to 30% by mass of the antimicrobial and antiviral composition according to any one of claims 2 to 8, 40 to 98.98% by mass of a non-aqueous organic solvent, and 0.01 to 10% by mass of a basic substance being soluble in the non-aqueous organic solvent.

10. The dispersion of the antimicrobial and antiviral composition according to claim 9 further comprising 0.01 to 20% by mass of a surfactant being soluble in the non-aqueous organic solvent.

11. A coating agent containing the antimicrobial and antiviral composition, comprising the dispersion of the antimicrobial and antiviral composition according to claim 9 or 10, and a binder component being curable under an environment of 10 to 120 °C.

12. An antimicrobial and antiviral film which the coating agent containing the antimicrobial and antiviral composition according to claim 11 is applied and then cured.

13. An antimicrobial and antiviral article comprising the antimicrobial and antiviral film according to claim 12 on at least one part of the outermost surface.

14. A method of producing the antimicrobial and antiviral material according to claim 1 comprising the steps of: