JP2014054600A - Method for producing photocatalytic function material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a photocatalytic function material capable of forming a photocatalyst layer having a photocatalytic function on a substrate.SOLUTION: The above problems are solved by a method for producing a photocatalytic function material 11, which comprises steps of: preparing a substrate 1; forming a photocatalyst material layer on the whole or a part of the surface of the substrate 1; subjecting the photocatalyst material layer to plasma processing to form a photocatalyst layer 3 having a photocatalytic function; and irradiating the photocatalyst layer 3 with visible light and in which the product of the illuminance (lx) and the irradiation time (hr) of the visible light is set at 1×10or more. In the step of forming the photocatalyst layer, a discharge gas used in the plasma processing preferably is argon gas, carbon dioxide gas, carbon monoxide gas, nitrogen gas, ammonia gas, carbon tetrafluoride, carbon hexafluoride or a mixed gas thereof.

Description

  The present invention relates to a method for producing a photocatalytic functional material, and more particularly to a method for producing a photocatalytic functional material capable of forming a photocatalytic layer having high photocatalytic activity on a substrate.

  It is known that a photocatalyst can generate a radical having a strong oxidizing power when irradiated with light and oxidize and decompose organic substances. Photocatalytic materials in which such a photocatalyst is supported on various base materials have been proposed. For example, Patent Documents 1 and 2 propose a photocatalytic material in which a nonwoven fabric is used as a base material, an inorganic compound or the like is provided on the base material, and the photocatalyst is supported on the inorganic compound or the like.

  Patent Document 1 proposes a technique in which a silica thin film or an inorganic oxide film is formed on the fiber surface of a nonwoven fabric and a photocatalyst is provided thereon. This technology is characterized in that a silica thin film or an inorganic oxide film provided on the surface of a nonwoven fabric fiber material is provided as a material that is hardly decomposed by a photocatalytic reaction, and as a result, the rigidity, toughness of the nonwoven fabric, It is said that the deterioration of strength and the release of odorous gas components caused by the photocatalytic reaction can be prevented without impairing the preferable properties of the substrate such as porosity.

  Patent Document 2 proposes a technique for producing an inorganic / organic component gradient fiber having a component gradient structure in which the content of the metal oxide component in the fiber continuously changes on the surface of the fiber. . And the functional fiber product which processed the inorganic / organic component gradient fiber into the nonwoven fabric, and provided the thin film of functional inorganic materials, such as a photocatalytic active material, on the surface of the nonwoven fabric is proposed. The inorganic / organic component gradient fibers can support functional inorganic materials such as photocatalytic active materials, have practical strength, are lightweight and inexpensive.

JP 2000-107610 A JP 2003-155622 A

  However, the technique proposed in Patent Document 1 has a complicated and complicated process for forming a silica thin film and an inorganic oxide film, and the technique proposed in Patent Document 2 also has a very complicated manufacturing process and costs. There was a difficulty of being bulky. In the field of photocatalytic functional materials including Patent Documents 1 and 2, it is required to enhance the photocatalytic function.

  The objective of this invention is providing the manufacturing method of a photocatalyst functional material which can form the photocatalyst layer which has high photocatalytic ability on a base material.

  The method for producing a photocatalytic functional material according to the present invention for solving the above problems includes a step of preparing a base material, a step of forming a photocatalytic material layer on all or part of the surface of the base material, and the photocatalytic material. The step of plasma-treating the layer to form a photocatalytic layer having photocatalytic activity and the step of irradiating the photocatalytic layer with visible light under a condition satisfying the following formula (1) are characterized.

  In the method for producing a photocatalytic functional material according to the present invention, in the photocatalyst layer forming step, the discharge gas used in the plasma treatment is argon gas, carbon dioxide gas, carbon monoxide gas, nitrogen gas, ammonia gas, carbon tetrafluoride. , Sulfur hexafluoride, or a mixed gas containing them.

  In the method for producing a photocatalytic functional material according to the present invention, the photocatalyst material layer includes a titanium oxide photocatalyst material layer, a tungsten oxide photocatalyst material layer, a zinc oxide photocatalyst layer, an iron oxide photocatalyst layer, and a strontium titanate photocatalyst layer. Alternatively, the cadmium sulfide photocatalyst layer, the gallium arsenide photocatalyst layer, and the gallium phosphorous photocatalyst material layer may be used.

  In the method for producing a photocatalytic functional material according to the present invention, a step of forming an inorganic layer on all or part of the surface of the substrate between the step of preparing the substrate and the step of forming the photocatalyst material layer You may comprise so that it may have.

  According to the present invention, a photocatalytic functional material that exhibits a high photocatalytic function can be produced. More specifically, according to the method for producing a photocatalytic functional material according to the present invention, the photocatalyst material layer formed on all or part of the substrate surface is subjected to plasma treatment, and then irradiated with visible light under predetermined conditions. Thus, the photocatalytic function can be enhanced.

It is typical sectional drawing which shows an example of the photocatalyst functional material manufactured with the manufacturing method which concerns on this invention, (A) is examples, such as a nonwoven fabric base material, (B) is an example of a film-form base material. . They are a top view (A) which shows an example of a photocatalyst functional material at the time of using a nonwoven fabric base material, etc., and sectional drawing which shows an example of the photocatalyst functional fiber which comprises the photocatalyst functional material. It is typical sectional drawing which shows the manufacturing process in which a photocatalyst layer is provided on a photocatalyst functional fiber. It is typical sectional drawing which shows the manufacturing process in which a photocatalyst layer is provided on the three-dimensional structure of a film-form base material.

  Hereinafter, the method for producing the photocatalytic functional material according to the present invention will be described. The present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist thereof.

[Method for producing photocatalytic functional material]
The method for producing the photocatalytic functional material 11 according to the present invention is a method for producing the photocatalytic functional material shown in FIGS. That is, as shown in FIGS. 3 and 4, the manufacturing method includes a step of preparing the substrate 1 (preparation step) and a step of forming the photocatalytic material layer 3 ′ on all or part of the surface of the substrate 1. (Photocatalyst material layer forming step), photocatalyst material layer 3 ′ is plasma treated to form photocatalyst layer 3 having photocatalytic activity (photocatalyst layer forming step), and then the photocatalyst layer 3 has the following formula (1) And a step of irradiating visible light under a condition that satisfies (visible light irradiation step).

  According to such a method for producing the photocatalytic functional material 11, after the photocatalyst layer forming step in which the photocatalyst material layer 3 ′ is subjected to plasma treatment to form the photocatalyst layer 3, visible light irradiation is performed on the photocatalyst layer 3 under the above conditions. Since it has a process, not only a substrate having a flat surface or a curved surface (not shown), but also a substrate 1 in which a fiber material 1 'and the like are complicated and complicated like a nonwoven fabric substrate or a woven fabric substrate having a three-dimensional structure (FIG. 1 (A)) and the base material 1 (FIG. 1 (B)) having a three-dimensional structure on the surface can be processed from the photocatalyst material layer 3 ′ by plasma treatment that can be processed to every corner. The photocatalyst layer 3 can be formed, and the photocatalytic function of the photocatalyst layer 3 can be enhanced by the subsequent visible light irradiation step.

  Hereinafter, the manufacturing method of the photocatalytic functional material will be described in order, and each component will also be described.

  The photocatalytic material layer 3 ′ and, if necessary, the inorganic layer 2 are formed on all or part of the surface of the substrate 1. In the following, when the surface of the substrate 1 is flat or curved (not shown), or when the surface of the substrate 1 has a three-dimensional structure (FIG. 1B), the “surface of the substrate 1” is Although it is literally, in the case of a nonwoven fabric base material or a woven fabric base material (FIG. 1 (A), FIG. 2), "fiber material 1 '" is read as "base material 1" on the structure. That is, the “surface of the base material 1” may be both the front and back surfaces of the base material 1 depending on the type of the base material, the surface of the three-dimensional structure part of the base material 1, or the base material 1 When is a nonwoven fabric substrate or the like, it may be the surface of the fiber material 1 ′ constituting the nonwoven fabric substrate or the like. And “all or part” means all or part of such a surface.

(Preparation process)
A preparation process is a process of preparing the base material 1 which has a three-dimensional structure, as shown to FIG. 3 (A) and FIG. 4 (A). The surface may be a substrate having a flat or curved surface (not shown), a substrate having a three-dimensional structure on the surface (FIG. 1 (B)), a nonwoven fabric substrate or a woven fabric substrate. Such a fiber material 1 ′ (FIG. 1A, FIG. 2) may be used. Among these, the base material 1 having a three-dimensional structure includes a part or all of which has a three-dimensional structure. For example, the substrate may have a three-dimensional structure, such as a nonwoven fabric substrate, a woven fabric substrate, or a porous substrate composed of the fiber material 1 ', and the surface has an uneven shape. A base material having a three-dimensional structure on a part of the surface thereof may be used like the provided base material. In addition, as long as there exists a part which has a three-dimensional structure at least, the base material in which the part and area | region which do not have a three-dimensional structure exist may be sufficient. “Substrate having a three-dimensional structure” is a substrate intentionally provided with a three-dimensional shaped structure on the surface of the substrate, and a substrate having a simple surface roughness that is not intentionally treated. And the like are included in the above-described planar substrate or curved substrate, and are not included in a substrate having a three-dimensional structure.

  As the base material 1, a base material (not shown) having a flat surface or a curved surface can be preferably exemplified. (A) A base material made of a fiber material such as a non-woven base material or a woven base material. In addition, (B) a film-like substrate having a three-dimensional structure on the surface can be mentioned more preferably.

  (A) As a base material comprised with a fiber material, the nonwoven fabric base material and woven fabric base material of a three-dimensional solid structure are preferable. In particular, since the nonwoven fabric base material is easily available at low cost and the specific surface area of the photocatalyst layer 3 can be improved, it can be preferably applied. In the following, the nonwoven fabric base material or the woven fabric base material and the fiber material 1 ′ constituting the nonwoven fabric base material or the woven fabric base material may be used synonymously (same meaning). The woven fabric base material may be collectively referred to as “nonwoven fabric base material”.

  The fiber material 1 ′ may be an organic fiber or an inorganic fiber. For example, polyester, acrylic resin, acrylic resin, acrylate ester resin, polyamide resin, vinylon resin, polypropylene resin, polyvinyl chloride Synthetic fibers formed of resin, polyethylene resin, vinylidene resin, polyurethane resin, aramid resin, polyarylate resin, polyparaphenylene oxazole (PBO) resin, ethylene vinyl glycol resin, polylactic acid resin, etc .; rayon, polynosic, cuvula, Recycled fibers such as lyocell; semi-synthetic fibers such as acetate, triacetate, and promix; polyacrylonitrile (PAN) carbon fiber, para aramid fiber, polyparaphenylene oxazole (PBO) fiber, ultrahigh molecular weight polyethylene fiber High strength, high elasticity fibers such as polyarylate fiber, high strength polyvinyl alcohol (PVA) fiber, and high strength polypropylene (PP) fiber; polyimide (PI) fiber, polyphenyl sulfide (PPS) fiber, meta-type aramid fiber, High heat-resistant and flame-retardant fibers such as PAN-based carbon fibers and polyether ether ketone fibers; biodegradable fibers such as polylactic acid fibers, polycaptolactone fibers, and polybutylene succinate fibers; polytetrafluoroethylene (PTFE) ) Fluorine fibers such as fibers and ethylene-tetrafluoroethylene copolymer (ETFE) fibers; polytrimethylene terephthalate (PTT) fibers; cellulose fibers; inorganic fibers such as glass, metal, and carbon; . These fiber materials 1 'may be used individually by 1 type, and may be used in combination of 2 or more type. When inorganic fibers are used, they may be used as they are, or may be used in combination with organic fibers other than the inorganic fibers described above, or the surface of the inorganic fibers may be coated with an organic material, or glass. Inorganic fibers such as metals and carbon may be used by mixing organic substances such as carbon components and hydrocarbon components.

  A conventionally well-known manufacturing method is applicable as a manufacturing method of a nonwoven fabric base material. Specifically, it can be manufactured by forming fibers in the spinning process, forming a fiber accumulation layer in the fleece forming process, and then bonding the fibers in the interfiber bonding process. As the spinning method in the spinning process, for example, conventionally known methods such as electrospinning method, solvent wet cooling gel spinning, electret method, flash spinning and the like can be applied. As the fleece forming method in the fleece forming process, for example, wet Conventionally known methods such as a fleece forming method, a dry fleece forming method, a spunbond method, and an airlaid method can be applied. Examples of methods for bonding fibers in a fiber bonding process include a thermal bond method, a spunlace method, and a needle. Conventionally known methods such as a punch method and a chemical bond method can be applied. In addition to these methods, for example, a lamination stretching method, a melt blown method, or the like can be applied as a method for producing a nonwoven fabric substrate in one step. In addition, the woven fabric base material can be manufactured using a fiber material 1 'using a conventionally known loom.

  The porosity of a nonwoven fabric substrate or the like (nonwoven fabric substrate or woven fabric substrate; the same applies hereinafter) is arbitrarily designed depending on the use of the photocatalytic functional material 11. For example, when the photocatalytic functional material 11 is used as a filter for air purification, the porosity of the nonwoven fabric substrate or the like is preferably in the range of 40% or more and 90% or less. For example, when the photocatalytic functional material 11 is used as a filter for water purification, the porosity of the nonwoven fabric substrate or the like is preferably in the range of 30% or more and 70% or less. In addition, the porosity measures the total volume of the fiber material which comprises a nonwoven fabric base material, etc., and the bulk volume of a nonwoven fabric base material, etc., (1-total volume of the fiber material which comprises a nonwoven fabric base material etc./nonwoven fabric base material) It is possible to evaluate with a value calculated by: The total volume of the fiber material can be calculated by, for example, increasing the water surface when the fiber material is submerged in a predetermined amount of water, and the bulkiness of the nonwoven fabric base material is calculated by, for example, length x width x height of the nonwoven fabric base material it can.

  The fiber diameter of the fiber material constituting the nonwoven fabric substrate or the like is arbitrarily designed depending on the use of the photocatalytic functional material 11, but is, for example, in the range of 0.01 μm or more and 100 μm or less, more preferably 0.05 μm or more, It is within the range of 30 μm or less.

  (B) Examples of the film-like substrate having a three-dimensional structure on the surface include those having a three-dimensional structure on the surface that is an uneven shape, such as a square shape, a mountain shape, a trapezoid shape, a curved shape, It includes a film-like substrate having a circular or cylindrical structure on the surface. Examples of other forms include a triangular shape such as a prism, or a polygonal shape such as a quadrangle, pentagon, hexagon, or octagon; a semi-cylindrical shape (kamaboko shape), a polyhedral cylindrical shape, a hemispherical lens shape (an eyelet shape or Moth-eye shape), various lens shapes such as a polyhedral lens shape and a Fresnel lens shape; These film-like substrates having a three-dimensional structure are used for improving optical properties, controlling wettability, and improving contactability and slipperiness.

  Such a film-like substrate is a film-like substrate formed of a resin material or a glass material, and has a three-dimensional structure such as an uneven shape on the surface thereof. The constituent material of the film-like substrate is not particularly limited, and examples thereof include various conventionally known resin materials and glass materials. Examples of the resin material include polyethylene resins such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), copolymers thereof, and polycyclohexanedimethylene terephthalate (PCT). Can do. Among these, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and copolymers thereof are preferable, and polyethylene naphthalate and polyethylene terephthalate are particularly preferable. Further, it may be a cycloolefin polymer such as a norbornene polymer, a cyclopentene polymer, or a cyclobutene polymer. Examples of the glass substrate include various glass materials such as quartz glass, soda glass, and alkali-free glass.

  The constituent material of the three-dimensional structure may be the same as or different from the constituent material of the base film-like substrate. For example, a three-dimensional structure made of the above-described resin material on a glass plate may be used.

  Such a film-like substrate can be easily purchased or can be obtained by a conventionally known method. For example, it can be obtained by forming a film-like base material having a three-dimensional structure at a time, or preparing a film-like base material having no three-dimensional structure, and shaping the three-dimensional structure on the surface thereof. The thickness, the height of the three-dimensional structure, the structure form, etc. are not particularly limited, and can be arbitrarily designed according to the application.

  The various base materials 1 having the three-dimensional structure described in the above (A) and (B) and the base material 1 having a flat or curved surface may be subjected to arbitrary pretreatment. Examples of the pretreatment include cleaning treatment and surface modification. Examples of the cleaning process include a process of spraying the cleaning liquid onto the base material 1 and a process of immersing the base material 1 in the cleaning liquid. Examples of the cleaning liquid include hydrophilic ethers such as diethyl ether, tetrahydrofuran and hydrofluoroether, water, weakly acidic aqueous solution, weakly alkaline aqueous solution, alcohols having 1 to 4 carbon atoms, ketones such as acetone and methyl ethyl ketone, and methyl acetate. And ethyl acetate. The surface modification is a treatment performed for the purpose of improving the adhesion with the inorganic layer 2 or the like formed on the substrate 1, and a physical treatment that represents the surface of the substrate 1 or the surface of the substrate 1. A chemical treatment for forming a functional group contributing to adhesion can be appropriately performed. For example, plasma treatment, graft polymerization treatment, coating treatment and the like can be mentioned.

(Inorganic layer forming process)
The inorganic layer forming step is not necessarily required, and is a step provided arbitrarily. For example, as shown in FIG. 3B and FIG. 4B, this is a step of forming the inorganic layer 2 on all or part of the surface of the substrate 1 described above. The inorganic layer 2 is a layer that functions as a base for the photocatalyst layer 3 to be described later, and functions to prevent the base material 1 from being oxidized and deteriorated by the photocatalytic activity of the photocatalyst layer 3. In other words. Furthermore, the inorganic layer 2 acts so that the base material 1 and the photocatalyst layer 3 are adhered with high adhesion. 3B and 4B, the inorganic layer 2 is provided so as to uniformly cover the entire surface of the substrate 1, but the inorganic layer 2 is not necessarily the entire surface of the substrate 1. In the case where the above-described action for preventing the oxidative degradation and the action for improving the adhesion are necessary and sufficient, it may be provided on a part of the surface of the substrate 1 depending on the degree.

The material for forming the inorganic layer 2 is not particularly limited as long as the above-described object can be achieved. For example, silicon carbide (SiC _x ), silicon oxide carbide (SiO _x C _y ), silicon oxycarbonitride (SiO _x C) _y N _z), silicon oxide _{(SiO x, x = 0~2)} , silicon nitride _{(SiN x, x = 0~1.3)} , a silicon compound such as silicon oxynitride _(SiO x _{N y);} zinc oxide ( ZnO _x ), aluminum-doped zinc oxide (ZnO _x : Al), boron-doped zinc oxide (ZnO _x : B), zinc oxide carbide (ZnO _x C _y ), zinc oxynitride (ZnO _x N _y ), zinc nitride (ZnN _x ), oxide nitride carbide zinc _{(ZnO x C y N z)} , zinc compounds such as IZO; zirconium oxide _(ZrO x), oxide zirconium carbide _{(ZrO x C} y), oxynitride, zirconium ZrO _x N _y), zirconium nitride _(ZrN x), zirconium compounds such as oxide carbide nitride, zirconium _{(ZrO x C y N z)} ; ITO, indium compounds such as indium oxide, tin oxide _(SnO x), oxycarbide tin ( SnO _x C _y), tin compounds such oxycarbide nitride, tin _{(SnO x C y N z)} ; chromium oxide _(CrO x), oxide chromium carbide _{(CrO x C} y), chromium oxynitride _{(CrO x N} y), Chromium compounds such as chromium nitride (CrN _x ) and chromium oxycarbide nitride (CrO _x C _y N _z ); aluminum oxide (AlO _x , x = 0 to 1.5), aluminum carbide (AlC _x ), aluminum oxide carbide ( AlO _x C _y ), aluminum oxynitride (AlO _x N _y ), aluminum oxycarbonitride (AlO _x C _y N _z ), etc. Munium compounds; titanium oxide (TiO _x , x = 0 to 2), titanium carbide (TiC _x ), titanium oxide carbide (TiO _x C _y ), titanium nitride (TiN _x ), titanium oxycarbonitride (TiO _x C _y N) _{and z} ) and the like. Here, x, y, z may represent each stoichiometric number, and may represent a numerical value less than the stoichiometric number. When it is less than the stoichiometric number, it means that each is in a deficient state (oxygen deficiency, carbon deficiency, nitrogen deficiency, etc.). For example, the same applies to those other than x = 0-2.

Among the materials for forming the inorganic layer 2, the insulating compound is preferably used because it does not cause a decrease in the photocatalytic performance of the photocatalytic layer 3. Examples of such an insulating compound include silicon carbide (SiC _x ), silicon oxide carbide (SiO _x C _y ), silicon oxycarbonitride (SiO _x C _y N _z ), and silicon oxide (SiO _x , x = 0 to 2). ), Silicon nitride (SiN _x , x = 0 to 1.3), silicon compound such as silicon oxynitride (SiO _x N _y ); zinc oxide carbide (ZnO _x C _y ), zinc oxynitride (ZnO _x N _y ) Zinc compounds such as zinc nitride (ZnN _x ) and zinc oxycarbonitride (ZnO _x C _y N _z ); zirconium oxide (ZrO _x ), zirconium oxide carbide (ZrO _x C _y ), zirconium oxynitride (ZrO _x N _y) ), zirconium nitride _(ZrN x), zirconium compounds such as oxide carbide nitride, zirconium _{(ZrO x C y N z)} ; ITO, indium in indium oxide Compounds; and tin oxide _(SnO x), oxycarbide tin _{(SnO x C} y), tin compounds such oxycarbide nitride, tin _{(SnO x C y N z)} ; chromium oxide _(CrO x), oxide chromium carbide _(CrO x C _y ), chromium oxynitride (CrO _x N _y ), chromium nitride (CrN _x ), chromium oxycarbonitride (CrO _x C _y N _z ), and other chromium compounds; aluminum oxide (AlO _x , x = 0 to 1.5) ), Aluminum carbide (AlC _x ), aluminum oxide carbide (AlO _x C _y ), aluminum oxynitride (AlO _x N _y ), aluminum oxycarbonitride (AlO _x C _y N _z ), and the like; titanium oxide (TiO _{x, x} = _0~2), titanium carbide _(TiC x), titanium oxide carbide _{(TiO x C} y), titanium nitride _(TiN x), oxide titanium carbide nitride It can be exemplified TiO _x C _y N _z) titanium compounds such like.

Among the materials for forming the inorganic layer 2, silicon carbide (SiC _x ), silicon oxide carbide (SiO _x C _y ), silicon oxycarbonitride (SiO _x C _y N _z ), silicon oxide (SiO _x , x = 0 to 2) ), Silicon nitride (SiN _x , x = 0 to 1.3), silicon oxynitride (SiO _x N _y ) and other silicon compounds are easily available at low cost, safety, stability, durability, And from a viewpoint of the adhesiveness of the base material 1 and the photocatalyst layer 3, it can mention preferably. Furthermore, among these, silicon compounds containing carbon elements such as silicon carbide (SiC _x ), silicon oxide carbide (SiO _x C _y ), and silicon oxycarbonitride (SiO _x C _y N _z ) are composed of the base material 1 and the photocatalytic layer. 3 is particularly preferable because it can further improve the adhesion to the substrate.

  Further, among these, when the substrate 1 is an organic material or contains an organic material, the inorganic layer 2 is selected from an inorganic compound containing carbon, an inorganic compound containing oxygen deficiency, and an inorganic compound containing nitrogen. It is preferable that it is 1 type, or 2 or more types of compounds. (1) In the case where the inorganic layer 2 is an inorganic compound containing carbon, the inorganic layer 2 has the same kind of element as the organic substance constituting the substrate 1, so that the interaction between the carbon components and the inorganic layer 2 Adhesiveness with the base material 1 can be improved. Moreover, although the photocatalyst layer 3 is provided on the inorganic layer 2, since the photocatalyst layer 3 is also the same inorganic compound layer as the inorganic layer 2, the adhesiveness of the inorganic layer 2 and the photocatalyst layer 3 can be improved. . (2) When the inorganic layer 2 is an inorganic compound such as an oxide containing oxygen vacancies, a strong bond can be formed between the inorganic layer 2 and the photocatalyst layer 3 based on the presence of oxygen vacancies. Adhesion can be improved. (3) Moreover, when the inorganic layer 2 is an inorganic compound containing nitrogen, a strong bond between the inorganic layer 2 and the photocatalyst layer 3 can be formed based on the presence of the nitrogen, and adhesion can be improved. Can be increased. (4) By providing such an inorganic layer 2 on the surface of the substrate 1, the adhesion between the inorganic layer 2 and the substrate 1 and the adhesion between the inorganic layer 2 and the photocatalyst layer 3 can be improved. The adhesion between the substrate 1 and the photocatalyst layer 3 can be enhanced. The inorganic layer 2 also functions as a dimensional variation (elongation, shrinkage) mitigation layer with respect to humidity and heat loads. In particular, the inorganic layer 2 containing nitrogen has a photocatalytic function that is extremely excellent in durability under humidity loads. Material 11 can be manufactured.

  Examples of the inorganic compound containing carbon include inorganic compounds containing carbon as a constituent component, such as silicon carbide, silicon oxide carbide, silicon oxycarbonitride, etc., among the above-described inorganic compounds. Inorganic compounds containing carbon are not included as constituents such as carbides and inorganic compounds containing carbon as a constituent of carbides and oxide carbides, but are included in inorganic compounds as carbon atoms, hydrocarbon groups, etc. It may be an inorganic compound contained in a trace amount or in an arbitrary amount. In addition, the trace amount or arbitrary amount of carbon can mention what is contained in the film-forming raw material containing carbon and a carbon group like the case where an inorganic compound is formed into a film by plasma CVD, for example. The inorganic compound containing carbon is preferable when the substrate 1 contains an organic substance because the substrate 1 and the carbon component are common and the adhesion with the substrate 1 can be further improved. Further, for example, the inorganic layer 2 of silicon compound containing carbon can further improve the adhesion between the substrate 1 and the photocatalyst layer 3 because the silicon compound containing carbon is intermediate between the organic substance and the inorganic substance. It is thought that this is because of having a natural property. Therefore, when the base material 1 contains organic substance, it functions as an intermediate | middle layer of the organic substance contained in the base material 1, and the photocatalyst layer 3 which is an inorganic substance, and can improve adhesiveness of both.

As an inorganic compound containing oxygen vacancies, among the various oxides such as silicon oxide, aluminum oxide, tin oxide, and zinc oxide described above, an oxide in which the oxygen constituting the oxide is less than the stoichiometric number is meant. doing. It can also be referred to as an oxygen-deficient inorganic compound or oxygen-deficient product. Examples of the oxygen-deficient oxide whose oxygen is less than the stoichiometric number include SiO _x whose x is less than 2. Also, other compounds containing oxygen, such as oxynitride and oxycarbide, can form an oxygen deficient state, and therefore may be an oxycarbide or oxynitride containing oxygen deficiency. The oxygen deficiency can form a strong bond between the inorganic layer 2 and the photocatalyst layer 3 and can improve adhesion.

  Examples of the inorganic compound containing nitrogen include inorganic compounds containing nitrogen as a constituent component, such as silicon nitride, silicon oxynitride, and silicon oxycarbonitride, among the above-described inorganic compounds. Inorganic compounds containing nitrogen are not included as constituents such as nitrides and nitrides as a constituent of nitrides and oxynitrides, but are not included in inorganic compounds as nitrogen atoms. Or the inorganic compound contained in arbitrary amounts may be sufficient. The inorganic compound containing nitrogen can form a strong bond between the inorganic layer 2 and the photocatalyst layer 3 due to the presence of the nitrogen, and can improve adhesion. In particular, the inorganic layer 2 containing nitrogen can produce a photocatalytic functional material that is extremely excellent in durability under humidity load.

  The inorganic layer 2 is formed by vapor deposition on all or part of the surface of the substrate 1 having a three-dimensional structure. Since the inorganic layer 2 can be formed in the gas phase by forming the inorganic layer 2 by vapor deposition, the inorganic layer 2 can be formed more easily than when the inorganic layer 2 is formed in a liquid phase such as an aqueous solvent. can do. Further, by forming the inorganic layer 2 in the gas phase, the inorganic layer 2 can be uniformly formed on all or a part of the substrate 1, preferably all.

  In the present invention, for example, when the base material 1 is a nonwoven fabric base material or the like made of a fiber material having a fine network structure, the inorganic layer 2 can be uniformly formed up to the back fiber material, Since the inorganic layer 2 can be formed on the surface of the fiber material without blocking the mesh, a photocatalytic functional material having a fine mesh and good durability can be efficiently produced. In addition, for example, when the substrate 1 is a film-like substrate having a three-dimensional concavo-convex shape on the surface, since the inorganic layer 2 can be uniformly formed on the concavo-convex surface, a photocatalytic functional material having good durability can be obtained. It can be manufactured efficiently.

  The vapor deposition method is not particularly limited as long as the inorganic layer 2 described above can be formed on the substrate 1. For example, a physical vapor deposition method such as a vacuum deposition method, a sputtering method or an ion plating method, or a chemical vapor deposition method such as a plasma chemical vapor deposition method (plasma CVD method) or an atomic layer deposition method (ALD method). Preferable examples can be given. The film forming conditions in these various forming methods may be adjusted by appropriately adjusting conventionally known film forming conditions in consideration of the physical properties and thickness of the inorganic layer 2 to be obtained.

  More specifically, (1) a vacuum vapor deposition method in which a raw material such as inorganic oxide, inorganic nitride, inorganic oxynitride, or metal is heated and deposited on the substrate 1, and (2) oxygen gas is introduced into the raw material. (3) Reactive sputtering method for depositing on the base material 1 by sputtering by introducing argon gas and oxygen gas into the target raw material, and (4) Raw material Is heated by a plasma beam generated by a holocathode plasma gun, and is deposited by ion plating on the base material 1. (5) Plasma chemical vapor is deposited on the base material 1 using an organosilicon compound as a raw material. A phase growth method, (6) an atomic layer deposition method in which film formation is performed one atomic layer by adsorption of the raw material gas by repeatedly introducing and evacuating the raw material gas in the film forming chamber, and the like can be used. In addition, in the vacuum deposition method, reactive deposition method, sputtering method, and the like described above, plasma assist may be used in order to accelerate the film formation reaction and improve the adhesion and denseness of the inorganic layer 2.

  Among the above-described vapor deposition methods, the plasma chemical vapor deposition method can be preferably cited from the viewpoint that the inorganic layer 2 having an intermediate property between the organic substance and the inorganic substance can be arbitrarily formed and the film forming speed is high.

  Although the thickness of the inorganic layer 2 is not particularly limited, it can be formed in the form of a thin film in the range of 5 nm to 300 nm, for example, more preferably in the range of 5 nm to 100 nm because it is formed by the above-described vapor deposition means. Of these, more preferably within the range of 5 nm or more and 50 nm or less. In the present invention, such a thin inorganic layer 2 can be preferably provided on the entire surface of the substrate 1 by vapor deposition means. In particular, in the case of a nonwoven fabric base material or the like made of a fiber material, the thin inorganic layer 2 can be uniformly formed in the back of the base material 1, which is preferable. If the thickness of the inorganic layer 2 is less than 5 nm, the entire surface of the substrate 1 may not be uniformly coated. On the other hand, when the thickness of the inorganic layer is increased to exceed, for example, 300 nm, the film stress becomes strong, and the inorganic layer is easily cracked. As a result, there is a problem that the inorganic layer is easily peeled off. Therefore, the upper limit thickness of the inorganic layer 2 is arbitrarily set in consideration of the material characteristics of the substrate 1.

  After the inorganic film 2 is formed, post-treatment may be performed after the inorganic layer 2 is formed in order to improve the coating suitability of the photocatalyst layer 3 and the adhesion of the photocatalyst layer 3 in the subsequent photocatalyst layer forming step. Good. As post-treatment, conventionally known methods such as corona treatment, plasma treatment, ozone irradiation, light irradiation, and electron beam irradiation can be applied. Examples of the plasma treatment include reduced-pressure plasma treatment and atmospheric pressure plasma treatment. Moreover, as light irradiation, the light source which can irradiate light of arbitrary wavelengths, such as visible light and an ultraviolet light, can be used. In addition, these treatments improve the wettability by chemically changing the surface physical properties and introducing functional groups, or physically changing the surface shape and increasing the surface area to increase the adhesion. Can be increased. These various post treatments may be used in combination. Moreover, since the inorganic layer 2 is formed under reduced pressure, the post-treatment may be continuously performed without opening to the atmosphere as it is.

(Photocatalyst material layer formation process)
The photocatalyst material layer forming step is a step of forming the photocatalyst material layer 3 ′ on all or part of the surface of the substrate 1, as shown in FIGS. 3 (C) and 4 (C). In the case where the inorganic layer 2 is provided on the substrate 1, the photocatalytic material layer 3 ′ is formed on the inorganic layer 2. The photocatalyst material layer 3 ′ is a layer that is changed to a photocatalyst layer 3 having a good photocatalytic ability by a plasma treatment described later. The photocatalytic ability may be exhibited even when the plasma treatment is not performed. However, in this case, the photocatalytic ability is not sufficient. Therefore, in the present invention, after the photocatalytic material layer 3 ′ is formed, the plasma treatment described later is performed. Thus, the photocatalytic layer 3 is formed.

The photocatalyst material layer 3 ′ is a layer formed of a photocatalyst material that becomes a photocatalyst by plasma treatment. Such a photocatalytic material is not particularly limited as long as it has photocatalytic activity. For example, titanium oxide (TiO ₂ ), tungsten oxide (WO ₃ ), zinc oxide (ZnO), iron oxide (Fe ₂ O ₃₎ ), Strontium titanate (SrTiO ₃ ), cadmium sulfide (CdS), gallium arsenide (GaAs), and gallium phosphide (GaP). These photocatalytic materials further include metals such as platinum (Pt), lead (Pd), and copper (Cu), and metal oxides such as copper oxide (CuO) in order to impart activity efficiency and visible light responsiveness. It may be supported. Note that titanium oxide (TiO ₂ ), tungsten oxide (WO ₃ ), and zinc oxide (ZnO) exhibit activity as a visible light responsive photocatalyst.

  Examples of the method for forming the photocatalyst material layer 3 ′ include a method for forming the photocatalyst material layer 3 ′ in the gas phase and a method for forming the photocatalyst material layer 3 ′ in the liquid phase. Examples of the method for forming the photocatalytic material layer 3 ′ in the gas phase include a sputtering method, a plasma CVD method, a thermal CVD method, and a vapor deposition method. Examples of a method for forming the photocatalyst material layer 3 ′ in the liquid phase include a method of applying a photocatalyst material layer forming coating solution on the substrate 1 or the inorganic layer 2. Examples of such a coating method include a method of coating the base material 1 with a photocatalyst material layer forming coating solution and a method of immersing the base material 1 in the photocatalyst material layer forming coating solution. As the above-described coating method, a conventionally known coating method can be applied. For example, a roll coating method, a gravure roll coating method, a kiss roll coating method, a reverse roll coating method, a Miya bar coating method, a gravure, etc. Examples of the coating method include spin coating, die coating, spray coating, mist coating, and aerosol deposition.

  The coating liquid for forming the photocatalyst material layer is obtained by dispersing photocatalyst particles in a liquid medium. Examples of the liquid medium include water, alcohols such as methyl alcohol and ethyl alcohol, aromatics such as benzene, toluene and xylene, esters such as ethyl acetate, ketones such as acetone, and the like. It may be used in a mixture of two or more. Among these, water is more preferable from the viewpoint of environmental harmony.

  In order to improve the dispersibility of the photocatalyst particles, a dispersion stabilizer may be blended in the photocatalyst material layer forming coating solution as long as the properties of the finally obtained photocatalyst layer 3 are not impaired. Examples of the dispersion stabilizer include ionic surfactants, wetting agents, thickeners, acids, and bases. These dispersion stabilizers may be used individually by 1 type, and may be used in combination of 2 or more type. From the viewpoint of dispersibility, the surfactant is more preferably an ionic surfactant such as carboxylate, sulfonate, sulfate ester salt, phosphate ester salt, alkylamine salt, and quaternary ammonium salt. .

Further, the coating liquid for forming the photocatalyst material layer may contain a binder (binder) as long as the properties of the finally obtained photocatalyst layer 3 are not impaired. In that case, the binder may be an organic binder material used as a general binder resin, an inorganic binder material, or an organic binder material and an inorganic binder material. It may be a mixed material. From the viewpoint of the characteristic stability of the photocatalyst layer 3, it is preferable to use an inorganic binder material. As such an inorganic binder material, one selected from aluminum oxide (AlO _x ), silicon oxide (SiO _x ), zirconium oxide (ZrO _x ), zinc oxide (ZnO _x ), titanium oxide (TiO _x ), and the like, It is preferable that 2 or more types are included.

  Although the density | concentration of the photocatalyst material contained in the coating liquid for photocatalyst material layer formation is not specifically limited, For example, it exists in the range of 5 mass% or more and 40 mass% or less. The amount of the dispersion stabilizer contained in the photocatalyst layer forming coating solution is not particularly limited, but is, for example, in the range of 10% by mass to 50% by mass.

  Although it does not specifically limit as a particle diameter of photocatalyst particle, For example, it exists in the range of 5 nm or more and 500 nm or less. By making the average particle diameter of the photocatalyst particles within this range, the specific surface area of the photocatalyst particles can be increased while maintaining the stable productivity of the photocatalyst particles. Will be advantageous. In addition, when used in applications where transparency is required, such as light transmittance and haze, the average particle size is preferably in the range of 5 nm or more and 100 nm or less. The particle shape of the photocatalyst particles is not particularly limited, and examples thereof include a spherical shape, a spheroid shape, a polygonal shape, and a scale shape. Further, the particles may be a porous body or have an uneven shape for the purpose of increasing the surface area. The photocatalyst particles may be porous particles of a photocatalyst, or a photocatalyst supported on a porous body. In addition, this average particle diameter can be evaluated by, for example, a value measured by a length measurement using a transmission electron microscope or a scattering particle meter distribution measuring device.

  The thickness of the photocatalyst material layer 3 ′ is not particularly limited, but when the photocatalyst material layer 3 ′ is formed in the gas phase, it is within a range of, for example, 50 nm or more and 300 nm or less. Further, when the formation of the photocatalytic material layer 3 ′ is performed in the liquid phase, for example, it is in the range of 200 nm or more and 3 μm or less.

(Photocatalyst layer forming step)
As shown in FIGS. 3D and 4D, the photocatalyst layer forming step is a step of forming the photocatalyst layer 3 having photocatalytic activity by plasma-treating the photocatalyst material layer 3 ′ described above.

  The plasma treatment can remove substances that reduce the photocatalytic ability or substances that impede the improvement of the photocatalytic ability, such as organic substances and impurities contained in the photocatalytic material layer 3 ′, and further damage the photocatalytic ability. Is not imparted to the photocatalytic material layer 3 ′ or the substrate 1, so that photocatalytic ability can be imparted. This plasma treatment can also be called “activation treatment” or “initialization treatment”. Further, by this plasma treatment, when the substrate 1 is a nonwoven fabric substrate or the like or a substrate having a three-dimensional structure, the plasma treatment can be applied to every corner, and as a result, the photocatalyst material layer 3 is obtained by the plasma treatment. The photocatalyst layer 3 can be formed from “.

  The photocatalyst layer 3 having photocatalytic activity as used in the present application is a gas back method in which a photocatalytic functional material is irradiated with light at an illuminance of 6000 lux of white fluorescent light for 6 hours, as shown in the evaluation of acetaldehyde deodorizing performance in Examples described later. When the acetaldehyde concentration is measured by the above method, it can be said that it is a “photocatalytic layer having a photocatalytic activity” when a reduction in acetaldehyde removal rate described later is confirmed by 10% or more as compared with the case where light is not irradiated.

  The thickness of the photocatalyst layer 3 is not different from the thickness of the photocatalyst material layer 3 ′. For example, when the photocatalyst material layer 3 ′ is formed in the gas phase, the thickness is in the range of 50 nm to 300 nm. In the case where the film is formed, the thickness is in the range of 200 nm to 3 μm.

The plasma treatment is a treatment for activating the photocatalyst material layer 3 ′ to form a photocatalyst layer 3 having photocatalytic activity, and is performed after the substrate 1 is provided with the photocatalyst material layer 3 ′. The activation by the plasma treatment has an advantage that it can be carried out in a very short time as compared with the activation by normal light irradiation. For example, as a standard evaluation standard for photocatalyst materials, as specified in 1 to 3 of JIS R 1701, as a pretreatment of a sample piece for performing an appropriate evaluation, “UV fluorescent lamp is used and the surface of the sample piece is used. It is stipulated that it is appropriate to “irradiate for 16 hours or longer under the condition that the irradiance at 15 W / m ² or higher” is appropriate, and activation at least on the order of several hours is required. On the other hand, the present invention has an advantage that the activation process (initialization process) can be performed in about 10 minutes by the activation by the plasma process, and the process can be performed in a very short time.

  As the discharge gas used in the plasma treatment, argon gas, carbon dioxide gas, carbon monoxide gas, nitrogen gas, ammonia gas, carbon tetrafluoride, sulfur hexafluoride, or a mixed gas containing them can be preferably used.

  In particular, when argon gas is used, since the Ar ions are relatively heavy and the ion implantation effect is high, a substance that lowers the photocatalytic ability or a substance that prevents the improvement of the photocatalytic ability is included in the three-dimensional structure of the substrate 1. It is considered that it can be effectively removed and a good activation treatment can be performed. In addition, when argon gas is used, since the said effect is dominant, if argon gas is a main body (50% or more), other gas may be contained. Examples of the other gas include oxygen gas, carbon dioxide or carbon monoxide containing oxygen atoms, nitrogen gas, ammonia gas, carbon tetrafluoride, and sulfur hexafluoride.

  In addition, if the reactive gas contains carbon, nitrogen, or fluorine, such as carbon monoxide gas, carbon dioxide gas, nitrogen gas, ammonia gas, carbon tetrafluoride, or sulfur hexafluoride, the photocatalyst can be used for organic matter, impurities, etc. It is preferable because a substance that lowers the performance or a substance that prevents the improvement of the photocatalytic ability can be effectively removed and damage to the photocatalytic material is small.

  On the other hand, when only oxygen gas was used, a sufficient effect was not obtained. The reason is not clear at the present time, but the photocatalyst material is greatly damaged and high photocatalytic performance cannot be obtained. In addition, etching (isotropic etching) due to wraparound to the contact portion with the base material 1 to which the photocatalyst material is in close contact occurs, and as a result, the adhesiveness of the photocatalyst material to the base material 1 is reduced, resulting in durability. Inferior to sex.

  As the plasma processing method, a power application method capable of obtaining an ion implantation effect is used. Such power application methods include power application method A that uses ion bombardment (implantation effect) during plasma processing, and at least two electrodes on the same side of the nonwoven fabric substrate, and power is supplied between the electrodes. The power application method A that forms plasma discharge can be preferably mentioned. In the former method A, it is possible to efficiently and evenly perform plasma processing up to the details of the three-dimensional structure of the substrate 1, and the effect of the activation processing is enhanced. Further, the latter method B can prevent abnormal discharge that may occur depending on plasma processing conditions and stabilize plasma discharge. For example, the base material 1 is a non-woven base material or a base material having a three-dimensional structure. In some cases, it is possible to efficiently and uniformly perform plasma processing up to the details. The reason is that since the base material 1 has a three-dimensional structure, when electrodes are installed on both sides of the base material 1 for processing, depending on the conditions such as the processing pressure, there is nothing that blocks the electrodes to some extent, This is because the impedance (the balance between voltage and current) is not constant, causing abnormal discharge and being unable to process stably. By such various power application methods, efficient plasma treatment can be performed to change the photocatalyst material layer 3 ′ to the photocatalyst layer 3. As the electrode arrangement structure, any of a flat electrode, a cylindrical holocathode electrode, a holoanode electrode, or a combination thereof can be used. In the latter method B, a magnetron mechanism may be installed in order to form a region having a high plasma density in the vicinity of the photocatalytic functional material 11. The magnetron mechanism can effectively concentrate the plasma in the vicinity of the substrate 1 in order to effectively perform the treatment by the formed plasma discharge.

  By such various power application methods, efficient plasma treatment can be performed to change the photocatalyst material layer 3 ′ to the photocatalyst layer 3. The electrode arrangement structure may be any of a flat plate electrode, a cylindrical holocathode electrode, a holoanode electrode, or a combination thereof. As an electrode structure, the thing of a various form can be used and it does not specifically limit.

(Visible light irradiation process)
In the visible light irradiation step, as shown in FIGS. 3D and 4D together with the photocatalyst layer forming step, the photocatalyst layer 3 is formed by plasma treatment, and then the above-described formula is applied to the photocatalyst layer 3. This is a step of irradiating visible light under conditions that satisfy (1).

The visible light irradiation treatment is a treatment for further enhancing the deodorizing performance of the photocatalytic functional material having the photocatalyst layer 3 activated by the plasma treatment. When black light irradiation, plasma irradiation, and visible light irradiation are applied individually, such an effect cannot be confirmed, and the effect is manifested only by combining plasma irradiation and visible light irradiation. As the irradiation treatment conditions of visible light for expressing such effects, it is preferable that the product of [illuminance of visible light (lx)] and [irradiation time (hr)] satisfy a relational expression of 1 × 10 ⁵ or more. . The photocatalytic function of the photocatalyst layer 3 can be enhanced by setting the illuminance and the irradiation time so as to be within such a range. In addition, the deodorizing performance by a photocatalyst functional material can be evaluated by a gas bag method by acetaldehyde decomposability (acetaldehyde deodorizing performance) as shown in the below-mentioned Example.

  For visible light irradiation, various visible light sources such as a white light can be used. Note that the irradiation condition of visible light may satisfy the above relational expression, but the illuminance is more preferably in the range of 1000 lx to 10000 lx. It is desirable to set the irradiation time so that the preferable illuminance falls within the range of the above relational expression.

[Photocatalytic substrate]
The photocatalytic functional material 11 can be formed by the above steps. In particular, it can be preferably applied as the photocatalytic substrate 11. As shown in FIGS. 1 and 2, the produced photocatalytic substrate 11 is formed on the substrate 1 and the photocatalyst layer 3 formed on all or part of the surface of the substrate 1 and provided with photocatalytic activity. have. And the photocatalyst layer 3 may not contain the organic substance which inhibits photocatalytic ability, or may be contained to such an extent that the photocatalytic function is not inhibited significantly. Moreover, the inorganic layer 2 may be provided between the base material 1 and photocatalyst material layer 3 ', and is provided with the hydrophilic surface or the hydrophobic surface as needed.

  The photocatalytic substrate 11 is included in such a degree that the photocatalytic layer 3 to which photocatalytic activity is imparted by plasma treatment does not contain an organic substance that inhibits photocatalytic activity, or does not significantly inhibit the photocatalytic function. It is preferable as the photocatalytic substrate 11 having effective photocatalytic activity. In particular, since the plasma treatment is performed, it is possible to remove substances that reduce the photocatalytic ability, such as organic substances and impurities, or substances that prevent the photocatalytic ability from being improved, and further damage the photocatalytic ability. 3 or the base material 1, the photocatalytic performance is excellent.

  Since the constituent elements such as the base material 1, the inorganic layer 2, the photocatalytic layer 3 and the like constituting the photocatalytic base material 11 are as described in detail in the description section of the above-described “method for producing a photocatalytic functional material”, Here, the same reference numerals are used and description thereof is omitted.

  In particular, the inorganic layer 2 is preferably a layer containing one or more compounds selected from an inorganic compound containing carbon, an inorganic compound containing oxygen deficiency, and an inorganic compound containing nitrogen. By providing such an inorganic layer 2 on the surface of the substrate 1, as described in detail in the explanation section of “Method for producing photocatalytic functional material”, the adhesion between the inorganic layer 2 and the substrate 1, the inorganic layer 2 and the photocatalyst Adhesiveness with the layer 3 can be enhanced, and as a result, the adhesiveness between the substrate 1 and the photocatalyst layer 3 can be enhanced.

  Moreover, it has a hydrophilic surface or a hydrophobic surface by the constituent material of a photocatalyst layer, or by plasma processing conditions or plasma discharge gas seed | species. Such a photocatalytic substrate 11 having a hydrophilic surface or a hydrophobic surface can be preferably applied to various applications.

  Such a photocatalytic substrate 11 can be used for various applications, and can be preferably applied to, for example, a filter having a photocatalytic function (photocatalytic filter). Applications of photocatalytic filters include, for example, deodorizing filters for decomposing formaldehyde, acetaldehyde, ammonia, acetic acid, etc., which are malodorous substances in the air, and deodorizing for removing allergen mites and pollen from the air. Filter, a filter for removing or killing viruses and bacteria, and the like. It can also be used as a constituent substrate 1 such as an air filter for an air cleaner, a liquid filter such as an ion exchange membrane, a gas separation membrane, a sound absorbing material, an exterior material, an interior material, and the like.

[Goods]
The article includes a photocatalytic substrate 11 produced by the above method. Since this article includes the photocatalytic substrate 11 having good durability, it can be applied to various articles. Types of goods include goods that use the function as filters, such as air purifiers, air conditioners, ventilation fans, deodorizing filters, airborne bacteria removal devices (bacterial contamination removal devices in the air), bacteria filters, gas filters, exhaust gas filters, It can be used as a constituent member of articles such as In addition, the surface of an article utilizing the function as a liquid filter, such as an ion exchange membrane, a desalting machine, a filter, a dialysis membrane, a water purifier, a reverse osmosis membrane, a gas separation membrane, a sound absorbing material, a flooring material, carpet, furniture, etc. It can be used as a constituent member of articles such as materials, automobiles, trains, airplanes, and other interior materials, wall materials, window materials (window pasting films).

  EXAMPLES The present invention will be described more specifically with reference to examples. However, the present invention is not limited to the description of the following examples unless it exceeds the gist.

[Example 1]
A non-woven fabric substrate (manufactured by Unitika Ltd., trade name: Marix 70200 WTO) having a surface layer formed of a polyethylene resin fiber material 1 ′ was prepared as the substrate 1. An inorganic layer 2 of silicon oxide carbide (SiO _x C _y ) having a thickness of 100 nm was formed on the base material 1 by plasma chemical vapor deposition (plasma CVD method). A titanium oxide photocatalyst material (trade name: MPT-623, manufactured by Ishihara Sangyo Co., Ltd.) is dispersed in water and an alcohol solvent to form a slurry on the inorganic layer 2, and then an aluminum oxide binder and a surfactant are added. The coating solution thus prepared was applied and dried to form a photocatalytic material layer 3 ′ around the fiber material 1 ′. Specifically, the photocatalyst material after drying was applied with a bar coat so that the amount of the photocatalyst material was 1.0 g / m ² , and the photocatalyst material layer 3 ′ was formed by holding at 100 ° C. for 5 minutes for curing.

  Thereafter, in order to activate the photocatalytic material layer 3 ′, plasma treatment was performed using a parallel plate type plasma CVD apparatus. The frequency of the power source used for the plasma discharge was 13.56 MHz RF discharge. Argon gas was introduced at 100 sccm from a gas supply pipe connected to the chamber of the plasma CVD apparatus, the pressure in the chamber was set to 10 Pa, RF power of 300 W was applied, and plasma discharge treatment was performed for 10 minutes.

  Subsequently, in order to further activate the photocatalytic material layer 3 ′, a white light (trade name: Rapid Start FLR20S W / M, manufactured by Toshiba Lighting & Technology Co., Ltd.) was used, and irradiation with visible light was performed at an illuminance of 5000 lx for 40 hours. It was. The product of irradiation illuminance lx and time h is 200000. Thus, the photocatalytic functional material 11 of Example 1 was produced.

[Example 2]
In Example 1, the visible light irradiation treatment was performed at an illuminance of 10000 lx for 10 hours. Other than that was carried out similarly to Example 1, and produced the photocatalyst functional material 11 of Example 2. FIG.

[Example 3]
In Example 1, visible light irradiation treatment was performed for 100 hours at an illuminance of 1000 lx. Other than that was carried out similarly to Example 1, and produced the photocatalyst functional material 11 of Example 3. FIG.

[Example 4]
In Example 1, the gas used in the plasma treatment was changed to argon gas at 100 sccm, and the visible light irradiation treatment was performed at an illuminance of 5000 lx for 40 hours. Other than that was carried out similarly to Example 1, and produced the photocatalyst functional material 11 of Example 4. FIG.

[Example 5]
In Example 1, the gas used in the plasma treatment was changed to 100 sccm of nitrogen instead of the argon gas, and the irradiation treatment with visible light was performed at an illuminance of 5000 lx for 40 hours. Other than that was carried out similarly to Example 1, and produced the photocatalyst functional material 11 of Example 5. FIG.

[Comparative Example 1]
In Example 1, visible light irradiation treatment was performed at an illuminance of 5000 lx for 10 hours. Other than that was carried out similarly to Example 1, and produced the photocatalyst functional material of the comparative example 1.

[Comparative Example 2]
In Example 1, no visible light irradiation treatment was performed. Other than that was carried out similarly to Example 1, and produced the photocatalyst functional material of the comparative example 2. FIG.

[Comparative Example 3]
In Example 1, the plasma treatment was changed to a black light 15 W / m ² treatment having a peak intensity near 350 nm, and a visible light irradiation treatment was performed at an illuminance of 5000 lx for 40 hours. Other than that was carried out similarly to Example 1, and produced the photocatalyst functional material of the comparative example 3. FIG.

[Deodorization performance evaluation]
The photocatalytic functional materials obtained in Examples 1 to 5 and Comparative Examples 1 to 3 were evaluated for acetaldehyde decomposability (acetaldehyde deodorizing performance) by a gas bag method. In the gas bag method, a test piece (100 mm × 100 mm) is inserted into a 3 L (liter) analytic barrier bag, and 99.5% acetaldehyde solution and synthetic air [nitrogen: oxygen (volume) are placed in the bag. 1) of a gas adjusted to an acetaldehyde concentration of 70 ppm with a ratio of 4: 1 and 50% RH]. Then, it was left for 10 minutes in the dark. Thereafter, irradiation was performed with an illuminance of 5000 lx using visible light (FLR20S), and the acetaldehyde concentration after 10 minutes and 3 hours was measured. The initial concentration was 70 ppm, and the acetaldehyde removal rate (%) after 10 minutes in the dark and after 3 hours of visible light irradiation was calculated according to the following formula. “Acetaldehyde removal rate (%) = [{(initial concentration) − (concentration after 10 minutes or 3 hours)}} / (initial concentration)] × 100”. As a result, those with an acetaldehyde removal rate of 90% or more are ranked “A”, those with a removal rate of less than 90% and 50% or more are ranked “B”, and those with a removal rate of less than 50% are ranked “C”. " The results are shown in Table 1.

  From the above results, it was found that a reduction in the acetaldehyde concentration at the initial stage was observed and high deodorization performance was exhibited under the treatment conditions in which the product of visible light illuminance (lx) and irradiation time (hr) satisfied 100,000 or more. .

DESCRIPTION OF SYMBOLS 1 Base material 1 'Fiber material 2 Inorganic layer 3 Photocatalyst layer 3' Photocatalyst material layer 10 Photocatalyst functional fiber 11 Photocatalyst functional material (photocatalytic base material)

Claims (4)

A step of preparing a substrate, a step of forming a photocatalytic material layer on all or part of the surface of the substrate, a step of plasma-treating the photocatalytic material layer to form a photocatalytic layer having photocatalytic activity, And a step of irradiating the photocatalyst layer with visible light under a condition satisfying the following formula (1):

  In the photocatalyst layer forming step, the discharge gas used in the plasma treatment is argon gas, carbon dioxide gas, carbon monoxide gas, nitrogen gas, ammonia gas, carbon tetrafluoride, sulfur hexafluoride, or a mixed gas containing them. The method for producing a photocatalytic functional material according to claim 1.   The photocatalyst material layer is a titanium oxide photocatalyst material layer, a tungsten oxide photocatalyst material layer, a zinc oxide photocatalyst layer, an iron oxide photocatalyst layer, a strontium titanate photocatalyst layer, a cadmium sulfide photocatalyst layer, or a gallium arsenide photocatalyst layer. And the method for producing a photocatalytic functional material according to claim 1, wherein the photocatalytic functional material is any one layer selected from gallium phosphide-based photocatalytic material layers. 4. The method according to claim 1, further comprising a step of forming an inorganic layer on all or part of the surface of the base material between the step of preparing the base material and the step of forming the photocatalytic material layer. A method for producing the photocatalytic functional material according to Item.

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