JP2014031470A - Method for maintaining the hydrophilicity of a substrate surface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel methodology capable of easily bestowing, regardless of environments where a substrate is placed, an anticlouding and/or antifouling property onto the substrate surface and of maintaining the anticlouding and/or antifouling property of the substrate over a long period.SOLUTION: The surface hydrophilicity of a substrate having a hydrophilic surface is maintained over a long period by treating the hydrophilic surface of the substrate at least with an oxidant such as hydrogen peroxide, etc. Moreover, it is desirable to treat the hydrophilic surface with a base such as ammonia, etc.

Description

The present invention relates to a novel method capable of maintaining antifogging and / or antifouling on a substrate surface for a long period of time, a substrate having long-term antifogging property or long-term antifouling property, and a method for producing the same.
About.

  The surface of various substrates such as glass plates may condense or become contaminated over time, and the visual or physical characteristics of the substrate may deteriorate. Therefore, in applications such as window glass and lighting equipment, it is desired to prevent or reduce condensation and / or contamination on the surface of the substrate as long as possible.

  Conventionally, for the purpose of preventing or reducing condensation, it has been practiced to heat the substrate, to provide a vacuum layer that lowers heat conduction, or to laminate a heat insulating material so that condensation of water vapor that causes condensation does not occur. ing. However, depending on the environment in which the substrate is placed, it is difficult to heat the substrate uniformly. In addition, the installation of the vacuum layer and the lamination of the heat insulating material require complicated processing, and further complicate the structure near the substrate surface. End up.

  On the other hand, for the purpose of preventing or reducing contamination, it has been proposed that the surface of the substrate has photocatalytic activity. However, it is difficult to exhibit a sufficient photocatalytic function in an environment that does not receive sunlight directly such as indoors.

  JP-A-2004-256736 discloses an antifouling laminate having a titanium or silicon compound as a first layer and a silicon compound as a second layer, but the first layer is only an optical property. This is for the purpose of imparting, and the antifouling property is borne solely by the silicon compound in the second layer.

Japanese Patent Laid-Open No. 2004-256736

  The present invention can easily impart antifogging properties and / or antifouling properties to the surface of the substrate regardless of the environment in which the substrate is placed, and also improve the antifogging properties and / or antifouling properties of the substrate. The purpose is to provide a new method that can be maintained for a long time.

  The object of the present invention is achieved by a method for maintaining hydrophilicity of a surface of a substrate having a hydrophilic surface, comprising a step of treating the hydrophilic surface with at least an oxidizing agent. Moreover, it is preferable to further include a step of treating the hydrophilic surface with a base.

The oxidizing agent preferably contains a peroxide, and the peroxide is preferably hydrogen peroxide.
Moreover, as a base, an inorganic base is preferable and ammonia is more preferable.

  The hydrophilic surface preferably has at least one hydrophilic group. The hydrophilic group is preferably a silicon atom-bonded hydroxyl group and / or a silicon atom-bonded polyether group.

  The hydrophilicity maintaining method of the present invention can further include a step of forming the hydrophilic surface by applying silanol, polysilicate, hydroxyl group-modified silicone and / or polyether-modified silicone to the surface of the substrate.

  The hydrophilicity maintaining method of the present invention may further include a step of disposing a positively charged substance and / or a negatively charged substance on the surface of the substrate before the step of forming the hydrophilic surface. Meanwhile, the substrate may include a positively charged substance and / or a negatively charged substance.

The positively charged material is (1) a cation;
It is preferably at least one selected from the group consisting of (2) a positively charged conductor or dielectric; and (3) a positively charged conductor and dielectric or semiconductor.

The negatively charged substance is (4) an anion;
(5) a negatively charged conductor or dielectric;
(6) A composite of a negatively charged conductor and a dielectric or semiconductor; and (7) at least one selected from the group consisting of substances having a photocatalytic function.

  The present invention also relates to a method for producing a substrate having a long-term antifogging property or a long-term antifouling property, comprising a step of treating the surface of a substrate having a hydrophilic surface with an oxidizing agent. It is preferable to further include a step of treating the hydrophilic surface with a base.

  The production method of the present invention may further comprise a step of forming the hydrophilic surface by applying silanol, polysilicate, hydroxyl group-modified silicone and / or polyether-modified silicone to the surface of the substrate.

  The manufacturing method of the present invention includes a step of disposing a positively charged substance, a negatively charged substance, or a positively charged substance and a negatively charged substance on the surface of the substrate before the step of forming the hydrophilic surface. Further, it can be included. Meanwhile, the substrate may include a positively charged substance and / or a negatively charged substance.

  The present invention also relates to a substrate having a long-term antifogging property or a long-term antifouling property having a hydrophilic surface treated with an oxidizing agent. It is preferred that the hydrophilic surface is further treated with a base.

  Furthermore, the present invention provides a laminate having a long-term antifogging property or a long-term antifouling property, comprising a positively charged substance and / or negatively charged substance-containing layer and a hydrophilic substance layer treated with at least an oxidizing agent on a substrate. Also related to structure.

  According to the present invention, it is possible to easily impart antifogging properties and / or antifouling properties to the surface of the substrate regardless of the environment in which the substrate is placed, and the antifogging properties and / or antifouling properties of the substrate. It is possible to maintain the sex for a long time.

  In the present invention, the hydrophilicity of the substrate surface can be maintained for a long period of time by a simple method of treating the hydrophilic surface of the substrate with an oxidizing agent such as hydrogen peroxide. Therefore, for example, a film of water is formed on the surface of the substrate when it rains, and contaminants adhering to the surface of the substrate can flow down, and the clean state of the substrate surface can be maintained for a long period of time. Moreover, the effect of the present invention can be further enhanced by treating the hydrophilic surface with a base such as ammonia.

  If a positively charged substance and / or a negatively charged substance is present on the substrate surface of the present invention, the adhesion of contaminants to the substrate surface can be more effectively prevented or reduced by electrostatic repulsion. .

  Moreover, since the surface of the substrate of the present invention is self-cleaned, maintenance is not required, and labor for cleaning the substrate can be reduced.

  In the present invention, a long-term antifogging property can be imparted to a substrate of any material by a simple method of treating the hydrophilic surface of the substrate with an oxidizing agent such as hydrogen peroxide. Further, by treating the entire hydrophilic surface of the substrate with an oxidizing agent, uniform antifogging properties can be exhibited over the entire hydrophilic surface of the substrate. Moreover, the effect of the present invention can be further enhanced by treating the hydrophilic surface with a base such as ammonia.

  Therefore, the present invention is preferably used for building materials, civil engineering / workpieces, refrigeration / freezers, electrical / electronic devices, vehicles, aircrafts, etc., particularly glass and polymer resin transparent substrates and mirrors used indoors and outdoors. can do.

Conceptual diagram showing the mechanism of positive charge imparted by a composite The conceptual diagram which shows an example of the positive charge and negative charge provision mechanism in this invention The conceptual diagram which shows the other example of the positive charge and negative charge provision mechanism in this invention The figure which shows the outline of an example of the 1st manufacturing method of a titanium oxide. Schematic cross-sectional view showing one embodiment of the present invention in which a positively charged substance, a negatively charged substance, and a positively charged substance and a negatively charged substance are arranged on the surface of the substrate, and then a hydrophilic group is further provided on the surface of the substrate A schematic cross-sectional view showing another embodiment of the present invention in which a hydrophilic group is provided on the surface of a substrate when the substrate includes a positively charged substance, a negatively charged substance, and a positively charged substance and a negatively charged substance, respectively. Conceptual diagram showing the mechanism by which contaminants are removed from the positively charged substrate surface Schematic diagram showing the mechanism by which contaminants are removed from the surface of a positively and negatively charged substrate

  The substrate used in the present invention is not particularly limited, and may be composed of various hydrophilic or hydrophobic materials and inorganic or organic materials.

  Examples of the inorganic base include transparent or translucent glass such as soda lime glass, quartz glass, and heat-resistant glass, or a base made of a metal oxide such as indium tin oxide (ITO), and silicon or metal. Can be mentioned. Examples of the organic base include a base made of plastic. Specific examples of plastics include, for example, polyethylene, polypropylene, polycarbonate, acrylic resin, polyester such as PET, polyamide, ABS resin, thermoplastic resin such as polyvinyl chloride, and polyurethane, melamine resin, urea resin, Examples thereof include thermosetting resins such as silicone resins, fluororesins, and epoxy resins. In view of heat resistance, an inorganic base is preferable, and a base made of resin, metal, or glass is particularly preferable at least partially or preferably all. The material of the organic base is preferably a thermosetting resin. It is preferred that at least a part or preferably all of the substrate is transparent at least in the visible light region.

  The shape of the substrate is not particularly limited, and can be any shape such as a cube, a rectangular parallelepiped, a sphere, a spindle, a sheet, a film, and a fiber. The substrate surface may have a flat surface and / or a curved surface, and may be embossed, but preferably has smoothness.

  The surface of the substrate may be painted, and coating materials include alkyd resin, acrylic resin, amino resin, polyurethane resin, epoxy resin, silicone resin, fluorine resin, acrylic silicon resin, unsaturated polyester resin, UV curable resin, A so-called paint coating containing a synthetic resin such as a phenol resin, a vinyl chloride resin, or an organic resin emulsion and a colorant can be suitably used.

  The thickness of the coating film is preferably 0.01 to 100 μm, more preferably 0.1 to 50 μm, and particularly preferably 0.5 μm to 10 μm. Examples of the coating means that can be used include spray coating, dip coating, flow coating, spin coating, roll coating, brush coating, and sponge coating. In order to improve the physical performance such as the hardness of the coating film and the adhesion to the substrate, it is desirable to heat within the allowable range of the substrate and the coating film.

  The substrate used in the present invention has a hydrophilic surface on at least a part, preferably all of the substrate. The hydrophilic surface can be formed by any method. For example, the hydrophilic surface can be formed by subjecting the surface of the substrate to corona discharge treatment, ultraviolet irradiation treatment, plasma treatment or the like.

  The hydrophilic surface preferably has at least one hydrophilic group. Examples of the hydrophilic group include a hydroxyl group, an ether group, a polyether group, a carbonyl group, an alkanoyl group, a carboxy group, an amino group, a sulfo group, and a phospho group. A hydroxyl group and a polyether group are preferable, and a silicon atom-bonded hydroxyl group and a silicon atom-bonded polyether group are more preferable.

  The hydrophilic group can be formed by surface treatment of the substrate. The type of surface treatment is not particularly limited. In addition to the above corona discharge, ultraviolet irradiation, and plasma treatment, a surface treatment agent containing a hydrophilic substance capable of providing a hydrophilic group is applied to the substrate surface. Can also be implemented. Examples of the hydrophilic substance used in this case include alcohol, ether, polyether, carboxylic acid, aldehyde, ketone, amine, sulfonic acid, and phosphonic acid. The application method is not particularly limited, and for example, spray coating method, dip coating method, flow coating method, spin coating method, roll coating method, brush coating, sponge coating, and the like can be applied. In addition, when a base | substrate is glass, a hydrophilic group can also be formed in the glass surface by the process cooled to normal temperature after heating to high temperature, for example, 300 degreeC or more, Preferably it is 400-900 degreeC.

  On the other hand, when the hydrophilic group is a silicon atom-bonded hydroxyl group, silanol, polysilicate, hydroxyl group-modified silicone or the like can be used as the hydrophilic substance. When the hydrophilic group is a silicon atom-bonded polyether group, polyether-modified silicone or the like can be used as the hydrophilic substance. Therefore, in the present invention, at least one selected from the group consisting of silanol, polysilicate, hydroxyl group-modified silicone and polyether-modified silicone can be applied to the surface of the substrate to form the hydrophilic surface.

The silanol is not particularly limited as long as it is a silanol compound having a silicon atom-bonded hydroxyl group, but the general formula: R ¹ R ² R ³ SiOH (wherein R ¹ , R ² and R ³ are independent of each other). And a triorganosilanol compound represented by a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms.

  Examples of the substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms include alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group; Cycloalkyl groups such as cyclopentyl group and cyclohexyl group; alkenyl groups such as vinyl group, allyl group and butenyl group; aryl groups such as phenyl group and tolyl group; aralkyl groups such as benzyl group; and carbon atoms of these groups A group in which the bonded hydrogen atom is at least partially substituted with a halogen atom such as fluorine, chlorine or iodine, or an organic group such as an epoxy group, glycidyl group, acyl group, carboxyl group, amino group, methacryl group or mercapto group (However, the total number of carbon atoms is 1 to 20).

  Examples of the triorganosilanol compound include tert-butyldimethylsilanol, methyldiisopropylsilanol, tert-amyldimethylsilanol, ethyldiisopropylsilanol, hexyldimethylsilanol, triisopropylsilanol, propyldiisopropylsilanol, 3-chloropropyldiisopropylsilanol, 3- Acetoxypropyldiisopropylsilanol, 3- (2-oxopyrrolidino) propyldiisopropylsilanol, methyldi-sec-butylsilanol, 1-methylcyclohexyldimethylsilanol, butyldiisopropylsilanol, tert-butyldiisopropylsilanol, ethyldi-sec-butylsilanol, phenyldiethylsilanol , Hexyl diethylsilano , Isopropyldiisobutylsilanol, pentyldiisopropylsilanol, cyclopentyldiisopropylsilanol, propyldi-sec-butylsilanol, isopropyldi-sec-butylsilanol, allyldi-sec-butylsilanol, 3-chloropropyldi-sec-butylsilanol, 3-acetoxy Propyl di-sec-butylsilanol, 3- (2-oxopyrrolidino) propyl di-sec-butylsilanol, phenylisopropylethylsilanol, methyldicyclopentylsilanol, hexyldiisopropylsilanol, cyclohexyldiisopropylsilanol, phenyldiisopropylsilanol, butyldi-sec-butylsilanol , Sec-butyldiisobutylsilanol, ethyl dicyclope Tilsilanol, benzyldiisopropylsilanol, propyldicyclopentylsilanol, isopropyldicyclopentylsilanol, allyldicyclopentylsilanol, 3-chloropropyldicyclopentylsilanol, 3-acetoxypropyldicyclopentylsilanol, 3- (2-oxopyrrolidino) propyldicyclopentylsilanol, Methyldiphenylsilanol, octyldiisopropylsilanol, 2-ethylhexyldiisopropylsilanol, ethyldiphenylsilanol, decyldiisopropylsilanol, butyldiphenylsilanol, tert-butyldiphenylsilanol, dodecyldiisopropylsilanol, tri-m-tolylsilanol, octadecyldiisopropylsilanol, 4- [ 4- ( Phenylamino) styryl] phenyldiisopropylsilanol, 4- [4- (dimethylamino) styryl] phenyldiisopropylsilanol, 5- [4- (diphenylamino) phenyl] -5 ′-[3- (hydroxydiisopropylsilyl) styryl]- 2,2′-bithiophene, 5- [4- (bis (9,9-dimethylfluoren-2-yl) amino) phenyl] -5 ′-[3- (hydroxydiisopropylsilyl) styryl] -2,2′- And bithiophene.

  As the polysilicate, alkyl polysilicate such as methyl polysilicate and ethyl polysilicate is preferable. As the methyl polysilicate, for example, methyl silicate 51 (manufactured by Mitsubishi Chemical Corporation) can be used, and as the ethyl polysilicate, for example, ethyl silicate 48 (manufactured by Colcoat Co., Ltd.) can be used. .

  As the hydroxyl group-modified silicone, one or both end hydroxyl group-modified diorganopolysiloxane is preferable. As the terminal hydroxyl group-modified diorganopolysiloxane, for example, a terminal silanol-modified dimethylpolysiloxane such as X-22-176DX, X-22-176F (manufactured by Shin-Etsu Chemical Co., Ltd.) can be used. As both-end hydroxyl group-modified diorganopolysiloxane, for example, both-end silanol-modified dimethylpolysiloxanes such as X-21-5841 and KF-9701 (manufactured by Shin-Etsu Chemical Co., Ltd.) can be used.

  As the polyether-modified silicone, a silicone modified with a polyoxyalkylene group comprising polyoxyethylene, polyoxypropylene, polyoxybutylene, or a combination thereof is preferable. Examples of the polyether-modified silicone include polyoxyethylene-modified dimethylpolysiloxanes such as SH3771M, SH3772M, SH3773M3, and SH3775M (manufactured by Toray Dow Corning Co., Ltd.); Poly (oxyethylene / oxypropylene) / organopolysiloxane copolymers such as oxyethylene / polyoxypropylene-modified dimethylpolysiloxane, polysilicone 13 and the like, and 3- (polyoxyethylene) propylheptamethyltrisiloxane and bis (poly It is possible to use a mixture of polyoxyethylene-modified dimethylpolysiloxane such as SH3746 (manufactured by Dow Corning Toray), which is a mixture of oxyethylene) propyloctamethyltetrasiloxane Kill.

  It is preferable that the hydrophilic substance is appropriately diluted with alcohol such as methanol, ethanol, isopropyl alcohol, 1-butyl alcohol, water, or a mixture thereof to form a surface treatment agent. Although the density | concentration of the hydrophilic substance in a surface treating agent is not specifically limited, 0.1-10 mass% is preferable, 0.2-5 mass% is more preferable, 0.3-2 mass% is still more preferable.

  The substrate surface is preferably dried after the surface treatment agent is applied to the substrate surface. Although drying temperature is not specifically limited, 15-100 degreeC is preferable, 20-80 degreeC is more preferable, and 25-60 degreeC is still more preferable. Drying at room temperature (25 ° C.) is particularly preferred. The thickness of the hydrophilic substance layer on the substrate surface is preferably 1 to 200 nm, more preferably 50 to 100 nm.

Before the substrate surface is dried, the substrate surface to which the surface treatment agent is applied may be further treated with running water. Thus, the silica to remove (SiO ₂₎ component, only the hydrophilic groups can be provided on the substrate surface.

  The substrate may be heated after the surface treatment of the substrate. The heating temperature depends on the type of the hydrophilic substance, but in order to fix the hydrophilic group more firmly, the heating temperature is preferably 80 ° C to 800 ° C, more preferably 150 ° C to 750 ° C.

  In the present invention, a positively charged substance and / or a negatively charged substance is preferably present on the surface of the substrate. Therefore, it is preferable to arrange a positively charged substance and / or a negatively charged substance on the surface of the substrate before forming the hydrophilic surface on the substrate. On the other hand, the substrate may originally contain a positively charged material and / or a negatively charged material. In this case, it is not necessary to newly arrange the positively charged material and / or the negatively charged material on the surface of the substrate. This may be done depending on the situation.

The positively charged substance is not particularly limited as long as it has a positive charge.
(1) cations;
(2) a positively charged conductor or dielectric; and (3) one or more selected from the group consisting of a positively charged conductor and a dielectric or semiconductor composite. Is preferred.

  The cation is not particularly limited, but ions of alkali metals such as sodium and potassium; ions of alkaline earth metals such as calcium; aluminum, cesium, indium, cerium, selenium, chromium, nickel and antimony Ions of metal elements such as iron, copper, manganese, tungsten, zirconium and zinc are preferred, and copper ions are particularly preferred. Furthermore, cationic molecules such as methyl violet, bismarck brown, methylene blue and malachite green, and organic molecules having a cationic group such as silicone modified with a quaternary nitrogen atom-containing group can also be used. The valence of ions is not particularly limited, and for example, a cation having 1 to 4 valences can be used.

  It is also possible to use a metal salt as a source of the metal ions. Specifically, aluminum chloride, chromium chloride, nickel chloride, first and second antimony chlorides, first and second iron chlorides, cesium chloride, indium trichloride, cerium chloride, selenium tetrachloride, cupric chloride And various metal salts such as manganese chloride, tungsten tetrachloride, tungsten oxychloride, potassium tungstate, zirconium oxychloride, zinc chloride, and barium carbonate. Furthermore, metal hydroxides such as aluminum hydroxide, iron hydroxide, chromium hydroxide, and indium hydroxide, hydroxides such as silicotungstic acid, and oxides such as oil and fat oxides can also be used.

  Examples of the positively charged conductor or dielectric may include a conductor or dielectric having a positive charge other than the above-mentioned cation. For example, the conductor used may be a metal from the viewpoint of durability. Desirably, metals such as aluminum, tin, cesium, indium, cerium, selenium, chromium, nickel, antimony, iron, copper, manganese, tungsten, zirconium, and zinc, and metal oxides can be used. A composite or alloy of these metals can also be used. The shape of the conductor is not particularly limited, and may be any shape such as a particle shape, a flake shape, or a fiber shape.

  A metal salt of some metals can also be used as the conductor. Specifically, aluminum chloride, first and second tin chloride, chromium chloride, nickel chloride, first and second antimony chloride, first and second iron chloride, cesium chloride, indium trichloride, first cerium chloride, Examples include various metal salts such as selenium tetrachloride, cupric chloride, manganese chloride, tungsten tetrachloride, tungsten oxychloride, potassium tungstate, gold chloride, zirconium oxychloride, and zinc chloride. Also, hydroxides or oxides such as indium hydroxide and silicotungstic acid can be used.

  Examples of the dielectric having a positive charge include dielectrics such as wool and nylon that are positively charged by friction.

  Next, the principle of applying a positive charge by the composite is shown in FIG. FIG. 1 is a conceptual diagram in which a conductor-dielectric or semiconductor-conductor combination is disposed on the surface of a substrate not shown. The conductor can have a positively charged state on the surface by the presence of a high concentration of free electrons that can freely move inside. Note that a conductive substance containing a cation may be used as the conductor.

  On the other hand, the dielectric or semiconductor adjacent to the conductor is dielectrically polarized due to the influence of the surface charge state of the conductor. As a result, negative charges are generated in the dielectric or semiconductor on the side adjacent to the conductor and positive charges are generated on the non-adjacent side. By these actions, the surface of the conductor-dielectric or semiconductor-conductor combination is positively charged, and a positive charge is imparted to the substrate surface. The size of the complex (referring to the length of the longest axis passing through the complex) can be in the range of 1 nm to 100 μm, preferably 1 nm to 10 μm, more preferably 1 nm to 1 μm, more preferably 1 nm to 100 nm. .

  The conductor constituting the composite used in the present invention is preferably a metal from the viewpoint of durability. Aluminum, tin, cesium, indium, cerium, selenium, chromium, nickel, antimony, iron, silver, copper, manganese, platinum , Metals such as tungsten, zirconium and zinc. Also, oxides, composites or alloys of these metals can be used. The shape of the conductor is not particularly limited, and may be any shape such as a particle shape, a flake shape, or a fiber shape.

  A metal salt of some metals can also be used as the conductor. Specifically, aluminum chloride, first and second tin chlorides, chromium chloride, nickel chloride, first and second antimony chlorides, first and second iron chlorides, silver nitrate, cesium chloride, indium trichloride, first chloride chloride Such as cerium, selenium tetrachloride, cupric chloride, manganese chloride, platinum platinum chloride, tungsten tetrachloride, tungsten oxychloride, potassium tungstate, gold chloride, zirconium oxychloride, zinc chloride, lithium iron phosphate, etc. Various metal salts can be exemplified. In addition, hydroxides of the above conductor metals such as aluminum hydroxide, iron hydroxide and chromium hydroxide, and oxides of the above conductor metals such as zinc oxide can also be used.

  As conductors, polyaniline, polypyrrole, polythiophene, polythiophene vinylon, polyisothianaphthene, polyacetylene, polyalkylpyrrole, polyalkylthiophene, poly-p-phenylene, polyphenylene vinylon, polymethoxyphenylene, polyphenylene sulfide, polyphenylene oxide, polyphenylene oxide Conductive polymers such as anthracene, polynaphthalene, polypyrene, and polyazulene can also be used.

Examples of the semiconductor include C, Si, Ge, Sn, GaAs, Inp, GeN, ZnSe, and PbSnTe. A semiconductor metal oxide, a photo semiconductor metal, and a photo semiconductor metal oxide can also be used. Preferably, besides titanium oxide (TiO ₂ ), ZnO, SrTiOP ₃ , CdS, CdO, CaP, InP, In ₂ O ₃ , CaAs, BaTiO ₃ , K ₂ NbO ₃ , Fe ₂ O ₃ , Ta ₂ O ₃ , WO ₃ , NiO, Cu ² O, SiC, SiO ₂ , MoS ₃ , InSb, RuO ₂ , CeO _2, etc. are used, and those in which the photocatalytic ability is inactivated with Na or the like are desirable.

Examples of the dielectric include barium titanate (PZT), which is a ferroelectric material, so-called SBT, BLT, and the following PZT, PLZT- (Pb, La) (Zr, Ti) O ₃ , SBT, SBTN-SrBi ₂ (Ta, Nb) ₂ O ₉ , BST— (Ba, Sr) TiO ₃ , LSCO— (La, Sr) CoO ₃ , BLT, BIT— (Bi, La) ₄ Ti ₃ O ₁₂ , BSO—Bi ₂ SiO _5, etc. Metal can be used. Also, silane compounds, silicone compounds, so-called organic modified silica compounds, which are organosilicon compounds, organic polymer insulating films, arylene ether-based polymers, benzocyclobutene, fluorine-based polymer parylene N, or F, fluorinated amorphous carbon, etc. Various low dielectric materials can also be used.

The negatively charged substance is not particularly limited as long as it has a negative charge.
(4) anion;
(5) a negatively charged conductor or dielectric;
(6) a composite of a negatively charged conductor and a dielectric or semiconductor, and (7) a substance having a photocatalytic function
It is preferable that it is 1 type or 2 types selected from the group which consists of.

  The anion is not particularly limited, but halide ions such as fluoride ion, chloride ion and iodide ion; inorganic ions such as hydroxide ion, sulfate ion, nitrate ion and carbonate ion An organic ion such as acetate ion. The valence of ions is not particularly limited, and for example, a 1 to 4 valent anion can be used.

  Examples of the conductor or dielectric having a negative charge include conductors or dielectrics in which a negative charge is generated other than the above anions, such as gold, silver, platinum, tin and other metals; Elements such as sulfur, selenium, tellurium; sulfides such as arsenic sulfide, antimony sulfide, mercury sulfide; clay, glass powder, quartz powder, asbestos, starch, cotton, silk, wool, etc .; conger, indigo, aniline blue, eosin, Examples thereof include colloids of dyes such as naphthol yellow. Among these, colloids of metals such as gold, silver, platinum and tin are preferable, and silver colloids are more preferable. In addition, the negative electrode of the battery made of the various conductors described above, and dielectrics such as negatively charged Teflon (registered trademark), vinyl chloride, polyethylene, and polyester can be used.

  As the semiconductor, those described above can be used.

As the substance having a photocatalytic function, a substance containing a specific metal compound and having a function of oxidizing and decomposing organic and / or inorganic compounds on the surface of the layer by photoexcitation can be used. The principle of photocatalyst by photoexcitation specific metal compounds, from the water or oxygen in the air OH ^- or O ₂ ^- radical species is generated in, that the radical species oxidize reductive decomposition of organic and / or inorganic compound It is generally understood that there is.

Examples of the metal compound include typical titanium oxide (TiO ₂ ), ZnO, SrTiOP ₃ , CdS, CdO, CaP, InP, In ₂ O ₃ , CaAs, BaTiO ₃ , K ₂ NbO ₃ , Fe ₂ O _3. , Ta ₂ O ₅ , WO ₃ , NiO, Cu ₂ O, SiC, SiO ₂ , MoS ₃ , InSb, RuO ₂ , CeO _{2 and the} like are known.

  The substance having a photocatalytic function may contain a metal (Ag, Pt) that improves the photocatalytic performance. Moreover, various substances, such as a metal salt, can be included in a range that does not deactivate the photocatalytic function. Examples of the metal salt include metal salts such as aluminum, tin, chromium, nickel, antimony, iron, silver, cesium, indium, cerium, selenium, copper, manganese, calcium, platinum, tungsten, zirconium, and zinc. In addition, hydroxides or oxides can be used for some metals or nonmetals. Specifically, aluminum chloride, stannous chloride, stannic chloride, chromium chloride, nickel chloride, primary and secondary antimony chloride, ferrous chloride, silver nitrate, cesium chloride, indium trichloride, primary chloride Various metals such as cerium, selenium tetrachloride, cupric chloride, manganese chloride, calcium chloride, platinum chloride, tungsten tetrachloride, tungsten oxychloride, potassium tungstate, ferric chloride, zirconium oxychloride, zinc chloride A salt can be illustrated. Examples of compounds other than metal salts include indium hydroxide, silicotungstic acid, silica sol, and calcium hydroxide.

In the excited state, the substance having the photocatalytic function adsorbs OH ⁻ (hydroxylated radical) and O ₂ ⁻ (oxygenated radical) from physically adsorbed water or oxygen on the surface of the substance, and the surface has an anion. However, when a positively charged substance coexists therewith, so-called photocatalytic activity is reduced or lost in accordance with the concentration ratio. However, in the present invention, a substance having a photocatalytic function does not need to oxidatively decompose a pollutant, and therefore can be used as a negatively charged substance. By coexisting a positively charged substance, deterioration due to oxidative decomposition of a binder (typically inorganic polymer and organic polymer) of a substance having a photocatalytic function can be avoided. Therefore, even when a substance having a photocatalytic function is used by being fixed with a binder, the antifouling function due to both positive and negative charge characteristics can be suppressed by coexisting with a positively charged substance while suppressing deterioration of the binder. Can be expressed.

  The positively-charged substance and the negatively-charged substance may each be disposed on the substrate surface alone, or may be combined and disposed on the substrate surface.

  FIG. 2 is a conceptual diagram showing one embodiment in which both positive and negative charges are arranged on the surface of a substrate, and dielectric or semiconductor-conductor having negative charge-dielectric or semiconductor-conductor having positive charge. This combination is an example in which the combination is provided on the substrate surface. As the conductor having a negative charge and the conductor having a positive charge shown in FIG. 2, those described above can be used.

  As shown in FIG. 2, a dielectric or semiconductor adjacent to a negatively charged conductor is dielectrically polarized due to the influence of the surface charge state of the conductor. As a result, a positive charge is generated in the dielectric or semiconductor on the side adjacent to the conductor having a negative charge, and a negative charge is generated on the side adjacent to the conductor having a positive charge. Due to these actions, the surface of the dielectric or semiconductor-conductor-dielectric or semiconductor-conductor combination shown in FIG. 2 is charged with a positive charge or a negative charge. The size of the composite of the conductor and dielectric or semiconductor (referring to the length of the longest axis passing through the composite) is 1 nm to 100 μm, preferably 1 nm to 10 μm, more preferably 1 nm to 1 μm, more preferably 1 nm. To 100 nm. In addition, the ratio of the composition material in the case of a composite including a conductor and dielectric forming a positive or negative charge surface or a semiconductor is preferably 1: 1 to 1:20 as a fine particle or volume ratio.

  FIG. 3 is a conceptual diagram showing another embodiment in which a positive charge and a negative charge are applied to the substrate surface.

  In FIG. 3, a conductor having a negative charge and a conductor having a positive charge are adjacent to each other, and the positive charge and the negative charge are reduced due to contact disappearance or the like. As the conductor having a negative charge and the conductor having a positive charge, those already described can be used.

  The arrangement method of the positively charged substance and / or the negatively charged substance is not particularly limited, but it is particularly preferable to form a positive or negatively charged substance layer on the substrate surface in the form of metal-doped titanium oxide.

The metal is preferably at least one metal element selected from the group consisting of cerium, gold, silver, platinum, copper, zirconium, tin, manganese, nickel, cobalt, iron and zinc, more preferably at least two, Silver or tin, and copper or iron are preferred. Examples of metal elements that can impart a positive charge include copper, manganese, nickel, cobalt, iron, and zinc. Examples of metal elements that can impart a negative charge include cerium, gold, silver, platinum, and tin. is there. As the titanium oxide, various oxides and peroxides such as TiO ₂ , TiO ₃ , TiO, and TiO ₃ / nH ₂ O can be used. In particular, titanium peroxide having a peroxo group is preferable. The titanium oxide may be any of amorphous type, anatase type, brookite type, and rutile type, and these may be mixed, but amorphous type titanium oxide is preferred.

  Amorphous titanium oxide does not have a photocatalytic function. On the other hand, anatase type, brookite type, and rutile type titanium oxides have a photocatalytic function. However, when copper, manganese, nickel, cobalt, iron, or zinc is combined at a certain concentration or more, the photocatalytic function is lost. Therefore, the metal-doped titanium oxide does not have a photocatalytic function. Amorphous titanium oxide is converted to anatase titanium oxide over time by solar heating or the like. However, anatase titanium oxide loses its photocatalytic function when combined with copper, manganese, nickel, cobalt, iron or zinc. After all, the metal-doped titanium oxide does not exhibit a photocatalytic function over time. On the other hand, titanium oxide doped with cerium, gold, silver, platinum, and tin has photocatalytic performance when titanium oxide is converted from amorphous type to anatase type, but positively charged substances coexist at a certain concentration or more. Since the case does not show photocatalytic performance, even when the metal-doped titanium oxide is used, it does not have a photocatalytic function over time.

  As a method for producing the metal-doped titanium oxide constituting the layer of the positively charged substance and / or the negatively charged substance, a production method based on a hydrochloric acid method or a sulfuric acid method, which is a general method for producing titanium dioxide powder, is employed. Alternatively, various methods for producing a liquid-dispersed titania solution may be employed. And the said metal can be compounded with a titanium oxide regardless of a manufacturing stage.

First Production Method First, a titanium hydroxide is formed by reacting a tetravalent titanium compound such as titanium tetrachloride with a base such as ammonia. Next, this titanium hydroxide is peroxo-oxidized with an oxidizing agent to form ultrafine particles of amorphous titanium peroxide. This reaction is preferably carried out in an aqueous medium. Furthermore, it is also possible to transfer to anatase-type titanium peroxide by arbitrary heat treatment. In any of the above steps, as a metal element having a positive charge or a negative charge, for example, cerium, gold, silver, platinum, tin, copper, zirconium, tin, manganese, nickel, cobalt, iron, zinc or their At least one of the compounds is mixed.

  The peroxidation oxidizing agent is not particularly limited, and various agents can be used as long as they can form a titanium peroxo compound, that is, titanium peroxide, but hydrogen peroxide is preferred. When hydrogen peroxide is used as the oxidizing agent, the concentration of hydrogen peroxide is not particularly limited, but is preferably 30 to 40%. It is preferred to cool the titanium hydroxide before peroxolation. The cooling temperature at that time is preferably 1 to 5 ° C.

  FIG. 4 shows an example of the first manufacturing method. In the illustrated manufacturing method, an aqueous solution of titanium tetrachloride and aqueous ammonia are mixed in the presence of at least one compound of cerium, gold, silver, platinum, copper, zirconium, tin, manganese, nickel, cobalt, iron, and zinc. And a mixture of the metal hydroxide and titanium hydroxide is formed. The concentration and temperature of the reaction mixture at that time are not particularly limited, but are preferably dilute and normal temperature. This reaction is a neutralization reaction, and it is preferable that the pH of the reaction mixture is finally adjusted to around 7.

  The metal and titanium hydroxides thus obtained are washed with pure water, cooled to around 5 ° C., and then peroxoated with hydrogen peroxide. Thereby, an aqueous dispersion containing titanium oxide fine particles having amorphous peroxo groups doped with metal, that is, an aqueous dispersion containing metal-doped titanium oxide can be produced.

Second Production Method A tetravalent titanium compound such as titanium tetrachloride is peroxo-oxidized with an oxidizing agent, and this is reacted with a base such as ammonia to form amorphous fine titanium peroxide. This reaction is preferably carried out in an aqueous medium. Furthermore, it is possible to transfer to anatase-type titanium peroxide by arbitrarily heat-treating. In any of the above steps, as a metal element having a positive charge or a negative charge, for example, cerium, gold, silver, platinum, copper, zirconium, tin, manganese, nickel, cobalt, iron, zinc or a compound thereof At least one of them is mixed.

Third production method A tetravalent titanium compound such as titanium tetrachloride is reacted simultaneously with an oxidizing agent and a base to form titanium hydroxide and peroxotate at the same time. Form. This reaction is preferably carried out in an aqueous medium. Furthermore, it is possible to transfer to anatase-type titanium peroxide by arbitrarily heat-treating. In any of the above steps, as a metal element having a positive charge or a negative charge, for example, cerium, gold, silver, platinum, copper, zirconium, tin, manganese, nickel, cobalt, iron, zinc or a compound thereof At least one of them is mixed.

  In the first to third manufacturing methods, it goes without saying that a mixture of amorphous titanium peroxide and anatase titanium peroxide obtained by heating the same can be used as the metal-doped titanium oxide.

Production Method by Sol-Gel Method A titanium alkoxide is mixed and stirred with a solvent such as water or alcohol, an acid or a base catalyst, and the titanium alkoxide is hydrolyzed to produce a sol solution of ultrafine titanium oxide. As a metal element having a positive or negative charge before or after the hydrolysis, for example, cerium, gold, silver, platinum, copper, zirconium, tin, manganese, nickel, cobalt, iron, zinc or a compound thereof At least one of the above is mixed. The titanium oxide thus obtained is an amorphous type having a peroxo group.

As the titanium alkoxide, a compound represented by the general formula: Ti (OR ′) ₄ (where R ′ is an alkyl group), or one or two alkoxide groups (OR ′) in the general formula is a carboxyl group. Alternatively, a compound substituted with a β-dicarbonyl group or a mixture thereof is preferable.

Specific examples of the titanium alkoxide include Ti (O—isoC ₃ H ₇ ) ₄ , Ti (O—nC ₄ H ₉ ) ₄ , Ti (O—CH ₂ CH (C ₂ H ₅ ) C ₄ H ₉ ) _4. , Ti (O—C ₁₇ H ₃₅ ) ₄ , Ti (O—isoC ₃ H ₇ ) ₂ [CO (CH ₃ ) CHCOCH ₃ ] ₂ , Ti (O—nC ₄ H ₉ ) ₂ [OC ₂ H ₄ N ( _{C 2 H 4 OH) 2]} 2, Ti (OH) 2 [OCH (CH 3) COOH] 2, Ti (OCH 2 CH (C 2 H 5) CH (OH) C 3 H 7) 4, Ti (O _{-nC 4 H 9) 2 (OCOC} 17 H 35) , and the like.

Tetravalent titanium compound As a tetravalent titanium compound used in the production of metal-doped titanium oxide, titanium hydroxide, also called orthotitanic acid (H ₄ TiO ₄ ), can be formed when reacted with a base. Any titanium compound can be used as long as it is a water-soluble inorganic acid salt of titanium such as titanium tetrachloride, titanium sulfate, titanium nitrate, and titanium phosphate. In addition, water-soluble organic acid salts of titanium such as titanium oxalate can be used. Of these various titanium compounds, titanium tetrachloride is preferred because it is particularly excellent in water solubility and no components other than titanium remain in the dispersion of metal-doped titanium oxide.

  When a solution of a tetravalent titanium compound is used, the concentration of the solution is not particularly limited as long as a titanium hydroxide gel can be formed, but a relatively dilute solution is preferable. Specifically, the solution concentration of the tetravalent titanium compound is preferably 5 to 0.01 wt%, and more preferably 0.9 to 0.3 wt%.

As the base to be reacted with the tetravalent titanium compound, various substances can be used as long as they can react with the tetravalent titanium compound to form titanium hydroxide. For example, ammonia, caustic soda, sodium carbonate Examples thereof include caustic potash, and ammonia is preferable.

  When the above base solution is used, the concentration of the solution is not particularly limited as long as a titanium hydroxide gel can be formed, but a relatively dilute solution is preferable. Specifically, the concentration of the base solution is preferably 10 to 0.01 wt%, and more preferably 1.0 to 0.1 wt%. In particular, the concentration of ammonia when ammonia water is used as the base solution is preferably 10 to 0.01 wt%, and more preferably 1.0 to 0.1 wt%.

Metal compounds Examples of the compounds of cerium, gold, silver, platinum, copper, zirconium, tin, manganese, nickel, cobalt, iron or zinc are as follows.
Ce compound: CeO ₂ , CeCl ₃ , Ce ₂ (SO ₄ ) ₃ , Ce (NO ₃ ) ₃ and their hydrates Au compound: AuCl, AuCl ₃ , AuOH, Au (OH) ₂ , Au ₂ O, Au ₂ O ₃
Ag compound: AgNO ₃ , AgF, AgClO ₃ , AgOH, Ag (NH ₃ ) OH, Ag ₂ SO ₄
Pt compounds: PtCl ₂ , PtO, Pt (NH ₃ ) Cl ₂ , PtO ₂ , PtCl ₄ , [Pt (OH) ₆ ] ²⁻
Ni compound: Ni (OH) ₂ , NiCl ₂
Co compound: Co (OH) NO ₃ , Co (OH) ₂ , CoSO ₄ , CoCl ₂
Cu compound: Cu (OH) ₂ , Cu (NO ₃ ) ₂ , CuSO ₄ , CuCl ₂ , Cu (CH ₃ COO) ₂
Zr compound: Zr (OH) ₃ , ZrCl ₂ , ZrCl ₄
Sn compound: SnCl ₂ , SnCl ₄ , [Sn (OH)] ⁺
Mn compound: MnNO ₃ , MnSO ₄ , MnCl ₂
Fe compound: Fe (OH) ₂ , Fe (OH) ₃ , FeCl ₃
Zn compound: Zn (NO ₃ ) ₂ , ZnSO ₄ , ZnCl ₂

  Titanium peroxide concentration in the aqueous dispersion obtained by the first to third production methods (total amount including cerium, gold, silver, platinum, copper, zirconium, tin, manganese, nickel, cobalt, iron, or zinc present together) ) Is preferably 0.05 to 15 wt%, and more preferably 0.1 to 5 wt%. Further, regarding the compounding amount of a metal element having a positive charge or a negative charge, for example, cerium, gold, silver, platinum, copper, zirconium, tin, manganese, nickel, cobalt, iron or zinc, the mole of titanium and the metal component The ratio is preferably 1: 1 from the present invention, but is preferably from 1: 0.01 to 1: 0.5, more preferably from 1: 0.03 to 1: 0.1, from the stability of the aqueous dispersion.

  In the present invention, the substrate is immersed in a metal-doped (per) titanium oxide-containing composition in the form of a solution, suspension or emulsion obtained by the above production method, or dip coating is performed, or the composition is applied to the substrate. Forming a metal-doped titanium oxide layer on the substrate surface by performing at least one step of non-heat drying or heat drying to volatilize the solvent or medium after coating with a spray, roll, brush, sponge, etc. Can do.

  The temperature in the case of heating is not specifically limited, For example, it can heat to arbitrary temperature of 30 degreeC or more. In addition, the titanium peroxide in the said composition changes to a titanium oxide (titanium dioxide) by heating. At this time, the amorphous titanium oxide is further transferred to anatase titanium oxide (in general, amorphous titanium oxide is transferred to anatase type by heating to 100 ° C. or higher). Therefore, when amorphous titanium peroxide is contained in the composition, it is preferable to heat to 100 ° C. or higher. In this case, anatase-type titanium oxide obtained by the process of amorphous-type titanium peroxide → amorphous-type titanium oxide → anatase-type titanium oxide is present on the substrate surface. Further, when anatase-type titanium peroxide is already contained in the composition, it is directly converted into anatase-type titanium oxide by heating.

  The composition preferably further contains an organosilicon compound and / or an inorganic silicon compound.

  Examples of the organosilicon compound include various organosilane compounds, and silicones such as silicone oil, silicone rubber, and silicone resin. These may be used alone or in a mixture. As the silicone, those having an alkyl silicate structure or a polyether structure in the molecule, or those having both an alkyl silicate structure and a polyether structure are preferable. Here, the alkyl silicate structure refers to a structure in which an alkyl group is bonded to a silicon atom of a siloxane skeleton. On the other hand, a polyether structure refers to a structure having an ether bond, and is not limited to these. Specifically, polyethylene oxide, polypropylene oxide, polytetramethylene oxide, polyethylene oxide-polypropylene oxide block copolymer are used. Examples thereof include molecular structures such as a polymer, a polyethylene polytetramethylene glycol copolymer, and a polytetramethylene glycol-polypropylene oxide copolymer. Among these, a polyethylene oxide-polypropylene oxide block copolymer is preferable from the viewpoint that the wettability on the substrate surface can be controlled by the block degree and the molecular weight.

  As the organosilicon compound, silicone having both alkyl silicate structure and polyether structure in the molecule is particularly preferable. Specifically, polyether-modified silicone such as polyether-modified polydimethylsiloxane is suitable. This can be produced by a known method, for example, by the method described in Synthesis Examples 1, 2, 3, 4 of JP-A-4-242499, or Reference Example of JP-A-9-165318. be able to. In particular, polyethylene oxide-polypropylene oxide block copolymer-modified polydimethylsiloxane obtained by reacting both terminal methallyl polyethylene oxide-polypropylene oxide block copolymers with dihydropolydimethylsiloxane is preferred. Specifically, TSF4445, TSF4446 (GE Toshiba Silicone Co., Ltd.), KP series (Shin-Etsu Chemical Co., Ltd.), SH 200, SH3746M, DC3PA, ST869A (Toray Dow Corning Co., Ltd.), etc. are used. be able to.

  The concentration of the organosilicon compound in the composition can be appropriately changed according to the degree of surface treatment of the substrate, but is typically 0.01 to 5.0% by weight, preferably 0.05. It is -2.0 weight%, More preferably, it is 0.1-1.0 weight%.

  Examples of the inorganic silicon compound include silica (silicon dioxide), silicon nitride, silicon carbide, silicate, polysilicate, silane and the like, and silica is preferable. As the silica, fumed silica, colloidal silica, precipitated silica and the like can be used, but colloidal silica is preferable. Examples of commercially available colloidal silica include PL-1 and PL-3 (Fuso Chemical Co., Ltd.). Examples of polysilicate include WM-12 (manufactured by Tama Chemical Industry Co., Ltd.) and silica sol 51 (manufactured by Colcoat Co., Ltd.). ) Etc. can be used.

  The concentration of the inorganic silicon compound in the composition can be appropriately changed according to the degree of surface treatment of the substrate, but is typically 0.01 to 98% by weight, preferably 0.1 to 90%. % By weight, more preferably 10.0 to 80% by weight.

  In addition to water, the composition may contain a hydrophilic medium such as alcohol, or a non-aqueous medium such as an organic solvent. The concentration of these media is typically 10 to 99.99% by weight, preferably 50 to 99.9% by weight, more preferably 80 to 99% by weight.

  An intermediate layer may be formed between the layer of the positively charged substance and / or the negatively charged substance and the substrate surface.

  The intermediate layer may be made of any organic or inorganic substance that is hydrophilic or hydrophobic.

  Examples of hydrophilic organic substances include polyethers such as polyethylene glycol, polypropylene glycol, and polyethylene glycol-polypropylene glycol block copolymers; polyvinyl alcohol; polyacrylic acid (including salts such as alkali metal salts and ammonium salts), polymethacryl Acid (including salts such as alkali metal salts and ammonium salts), polyacrylic acid-polymethacrylic acid (including salts such as alkali metal salts and ammonium salts) copolymers; polyacrylamide; polyvinylpyrrolidone; carboxymethylcellulose (CMC) And hydrophilic celluloses such as methylcellulose (MC); natural hydrophilic polymer compounds such as polysaccharides. It is also possible to use a composite material obtained by blending these polymer materials with an inorganic dielectric such as glass fiber, carbon fiber or silica. It is also possible to use a paint as the polymer material.

Examples of the hydrophilic inorganic material include SiO _{2 and} other silicon compounds.

  Examples of water-repellent organic materials include polyolefins such as polyethylene, polypropylene and polystyrene; acrylic resins such as polyacrylates, acrylonitrile / styrene copolymers (AS) and acrylonitrile / butadiene / styrene copolymers (ABS); polyacrylonitriles; Polyvinyl halides such as vinyl chloride and polyvinylidene chloride; polytetrafluoroethylene, fluoroethylene / propylene copolymer, polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), vinylidene fluoride / trifluoroethylene Fluorine resins such as copolymers; Polyesters such as polyethylene terephthalate and polycarbonate; Phenol resins; Urea resins; Melamine resins; Polyimide resins; Polyamide resins such as nylon Epoxy resins; and polyurethane.

  As the water-repellent organic substance, a fluororesin is preferable, and in particular, a vinylidene fluoride / trifluoroethylene copolymer having ferroelectricity and water repellency, a β-type crystal of polyvinylidene fluoride and those containing it are preferable. . Commercially available products can be used as the fluororesin, and examples of commercially available products include HIREC1550 manufactured by NTT-AT Co., Ltd.

  Furthermore, a copolymer comprising two or more types of olefins containing fluorine atoms, a copolymer of an olefin containing fluorine atoms and a hydrocarbon monomer, and a copolymer comprising two or more types of olefins containing fluorine atoms And a fluororesin emulsion comprising a surfactant and at least one fluororesin selected from the group consisting of a mixture of an acrylic resin and a thermoplastic acrylic resin, and a curing agent (JP-A-5-124880, JP-A-5-117578) JP-A-5-179191) and / or a composition comprising the above-mentioned silicone resin water repellent (see JP-A-2000-121543, JP-A-2003-26461). As this fluororesin emulsion, what is marketed can be used, and it can be purchased as a Zaffle series from Daikin Industries, Ltd. and as a Lumiflon series from Asahi Glass Co., Ltd. As the curing agent, a melamine curing agent, an amine curing agent, a polyvalent isocyanate curing agent, and a block polyvalent isocyanate curing agent are preferably used.

  Examples of the water-repellent inorganic material include silane-based, siliconate-based, silicone-based and silane composite-based, or fluorine-based water repellent or water absorption inhibitor. In particular, fluorine-based water repellents are preferable, and examples include fluorine-containing compounds such as perfluoroalkyl group-containing compounds or fluorine-containing compound-containing compositions. When the intermediate layer contains a fluorine-containing compound with high adsorptivity to the substrate surface, the chemical component of the water repellent or water absorption inhibitor reacts with the substrate to form a chemical bond after being applied to the substrate surface. It does not necessarily have to occur or the chemical components cross-link.

  The fluorine-containing compound that can be used as such a fluorine-based water repellent preferably has a molecular weight of 1,000 to 20,000 containing a perfluoroalkyl group in the molecule, and specifically, perfluorosulfonic acid. Salt, perfluorosulfonic acid ammonium salt, perfluorocarboxylate, perfluoroalkyl betaine, perfluoroalkyl ethylene oxide adduct, perfluoroalkylamine oxide, perfluoroalkyl phosphate ester, perfluoroalkyltrimethylammonium salt, etc. Can be mentioned. Especially, since it is excellent in the adsorptivity to the base-material surface, perfluoroalkyl phosphate ester and perfluoroalkyl trimethyl ammonium salt are preferable. As such materials, Surflon S-112, Surflon S-121 (both trade names, manufactured by Seimi Chemical Co., Ltd.) and the like are commercially available.

  In the case of a substrate having high water absorption, an intermediate layer containing a silane compound is preferably formed on the substrate in advance. Since this intermediate layer contains a large amount of Si—O bonds, the strength of the positive or negative charge substance-containing layer and the adhesion to the substrate can be improved. The intermediate layer also has a function of preventing moisture from entering the substrate.

  Examples of the silane compound include hydrolyzable silanes, hydrolysates thereof, and mixtures thereof. Various alkoxysilanes can be used as the hydrolyzable silane, and specific examples include tetraalkoxysilane, alkyltrialkoxysilane, dialkyldialkoxysilane, and trialkylalkoxysilane. Of these, one type of hydrolyzable silane may be used alone, or two or more types of hydrolyzable silanes may be mixed and used as necessary. Moreover, you may mix | blend various organopolysiloxane with these silane compounds. As a constituent material of the intermediate layer containing such a silane compound, for example, there is Dry Seal S (manufactured by Toray Dow Corning Co., Ltd.).

  Further, room temperature curable silicone resins such as methyl silicone resin and methyl phenyl silicone resin may be used as the constituent material of the intermediate layer. Examples of such room temperature curable silicone resins include AY42-170, SR2510, SR2406, SR2410, SR2405, and SR2411 (manufactured by Toray Dow Corning Co., Ltd.).

  The intermediate layer may be a paint film. Coating materials that make up the coating film include alkyd resins, acrylic resins, amino resins, polyurethane resins, epoxy resins, silicone resins, fluororesins, acrylic silicone resins, unsaturated polyester resins, UV curable resins, phenol resins, and vinyl chloride resins. A so-called paint coating containing a synthetic resin such as an impregnated resin emulsion and a colorant can be preferably used.

  The thickness of the coating film is preferably 0.01 to 100 μm, more preferably 0.1 to 50 μm, and particularly preferably 0.5 μm to 10 μm. Examples of the coating means that can be used include spray coating, dip coating, flow coating, spin coating, roll coating, brush coating, and sponge coating. In order to improve the physical performance such as the hardness of the coating film and the adhesion to the substrate, it is desirable to heat within the allowable range of the substrate and the coating film.

  In the present invention, the hydrophilicity of the hydrophilic surface can be maintained over a long period of time by treating the hydrophilic surface of the substrate with at least an oxidizing agent. Thereby, the base | substrate of this invention which has the hydrophilic surface processed with the oxidizing agent can exhibit long-term antifogging property or long-term antifouling property. Therefore, the base | substrate provided with the long-term antifogging property or long-term antifouling property of this invention can be manufactured by processing the said surface of the base | substrate which has a hydrophilic surface with an oxidizing agent.

  The oxidizing agent used in the present invention is not particularly limited as long as it has an oxidizing action, and various inorganic oxidizing agents and organic oxidizing agents can be used. Examples of the inorganic oxidizing agent include inorganic acids such as hypochlorous acid, chlorous acid, chloric acid, and perchloric acid, inorganic salts such as potassium nitrate, permanganate, and cerium ammonium nitrate, sodium percarbonate, and peroxidation. An inorganic peroxide such as hydrogen can be used, and examples of the organic oxidizing agent include organic systems such as benzoyl peroxide, acetone peroxide, methyl ethyl ketone peroxide, di-tert-butyl peroxide, and acetic acid. Although peroxides can be used, peroxides are preferred. Among the peroxides, inorganic peroxides are preferable in that no organic substances remain on the substrate, and hydrogen peroxide is more preferable from the viewpoint that no harmful by-products are generated after decomposition.

  In the present invention, the hydrophilic surface of the substrate can be treated by applying the oxidizing agent to the hydrophilic surface of the substrate as it is or in the form of a composition diluted in an appropriate medium. The composition is preferably a liquid at room temperature, and is preferably an aqueous liquid. Therefore, the medium is preferably water or a mixture of water such as methanol, ethanol, isopropyl alcohol, 1-butyl alcohol and water. Although the density | concentration of the oxidizing agent in a composition is not limited, 1-80 mass% is preferable and 2-50 mass% is more preferable. The application method is not particularly limited, and for example, spray coating method, dip coating method, flow coating method, spin coating method, roll coating method, brush coating, sponge coating, and the like can be used.

  After applying the oxidizing agent to the hydrophilic surface of the substrate, it is preferable to dry the surface. Drying can be performed at room temperature (25 ° C.) to high temperature (for example, 40 to 100 ° C.), and can be performed for several minutes to several hours (preferably several minutes to several tens of minutes). .

  In the present invention, it is preferable to further treat the hydrophilic surface of the substrate with a base. The hydrophilic surface of the substrate may be treated with a mixture of an oxidant and a base, but is preferably treated with a base after the treatment with the oxidant.

  The base used in the present invention is not particularly limited, and various inorganic bases and organic bases can be used. In addition to ammonia, inorganic bases such as sodium hydroxide, potassium hydroxide, and sodium bicarbonate are used. A base is preferable, and volatile ammonia is desirable from the viewpoint of preventing generation of residual components.

  Although the reason why the hydrophilicity of the hydrophilic surface of the substrate can be maintained over a long period of time by the treatment with the oxidizing agent is not clear, when a hydrophilic group exists on the surface of the substrate, the oxidizing agent attaches the hydrophilic group to the substrate. It is considered to be firmly fixed on the surface. Moreover, when using a base together, it is thought that the fixed state of a hydrophilic group is stabilized.

  Hereinafter, the function and effect of the present invention will be described in more detail.

  In the present invention, a substrate having a hydrophilic surface treated with an oxidant is difficult to form water droplets on the hydrophilic surface, and therefore, it is difficult to form condensation, so that it can exhibit antifogging properties. it can. In particular, visual impairment can be reduced by providing anti-fogging properties to makeup mirrors, automobile window inner surfaces, rearview mirrors, and the like. Further, due to the hydrophilicity of the substrate surface, for example, a film of water is formed on the substrate surface in rainy weather, and contaminants attached to the substrate surface can flow down, and the substrate surface can be cleaned. Therefore, according to the present invention, it is possible to easily impart antifogging properties and / or antifouling properties to the substrate surface regardless of the environment in which the substrate is placed.

  In the present invention, the hydrophilicity of the substrate surface can be maintained for a long time by a simple method of treating the hydrophilic surface of the substrate with an oxidizing agent such as hydrogen peroxide, preferably further with a base. Therefore, it is possible to maintain the antifogging property and / or antifouling property of the substrate for a long period without using a complicated method or apparatus.

  In addition, since the protective action of these substrate surfaces continues naturally, the clean state of the substrate surfaces can be maintained over a long period of time. Further, since the surface of the substrate is self-cleaned, maintenance for cleaning the surface of the substrate is unnecessary, and labor can be greatly reduced.

  When a positively charged substance and / or a negatively charged substance is present on the surface of the substrate of the present invention, in particular, a positively charged substance and / or a negatively charged substance-containing layer on the substrate, and at least a hydrophilic treated with an oxidizing agent. In the case of a laminated structure having a long-term antifogging property or a long-term antifouling property composed of a conductive material layer, adhesion of contaminants to the substrate surface can be more effectively prevented or reduced by electrostatic repulsion. . This point will be further described below.

  5A to 5C show a case where a positively charged substance, a negatively charged substance, and a positively charged substance and a negatively charged substance are arranged on the surface of the substrate, respectively, and then a hydrophilic group (here, “—OH” Is a schematic cross-sectional view showing one embodiment of the present invention. Although not shown, the hydrophilic group in FIG. 5 is at least treated with an oxidizing agent.

  6A to 6C show a case where a hydrophilic group (here, “—OH”) is formed on the surface of the substrate when the substrate includes a positively charged material, a negatively charged material, and a positively charged material and a negatively charged material, respectively. It is a schematic sectional drawing which shows another one aspect | mode of this invention provided. Although not shown, the hydrophilic group in FIG. 6 is at least treated with an oxidizing agent.

  Contaminants that are one of the causes of discoloration or discoloration of the substrate surface are caused by the gradual deposition of inorganic substances such as carbon and / or organic substances such as oil floating in the atmosphere on the substrate surface. Adhere.

  It is said that pollutants, especially oil, floating in the air indoors and outdoors are subjected to so-called photo-oxidation reaction by various electromagnetic waves including sunlight and are "oxidized" by combustion emissions. ing.

The photo-oxidation reaction is the action of electromagnetic waves such as sunlight, from the moisture (H ₂ O) and oxygen (O ₂ ) on the organic or inorganic surface to hydroxyl radical (.OH) and singlet oxygen ( ¹ O ₂ ). Is a phenomenon in which electrons (e ⁻ ) are extracted from the organic or inorganic material and oxidized. Due to this oxidation, the molecular structure of the organic substance is changed, and a discoloration or embrittlement phenomenon called deterioration is observed, and rust is generated in the inorganic substance, particularly metal. These “oxidized” organic or inorganic surfaces are positively charged by the extraction of electrons (e ⁻ ).

  In the present invention, since a positive charge, a negative charge, or both exist on the substrate surface or in the substrate surface layer, the organic substance or inorganic substance is naturally released from the substrate surface using electrostatic repulsion. Can do. That is, in the present invention, these contaminants can be removed from the substrate or the adhesion of these contaminants to the substrate can be avoided or reduced by the electrostatic repulsion effect provided by the substrate.

  FIG. 7 shows a mechanism for removing contaminants from a positively charged substrate surface (FIGS. 5A and 6A). In FIG. 7, the display of the hydrophilic group is omitted.

  In the embodiment shown in FIG. 7, a positively charged substance is disposed on the substrate surface or in the substrate surface layer, whereby a positive charge is imparted to the substrate surface (FIG. 7- (1)).

  Contaminants accumulate on the substrate surface and are photooxidized by the action of electromagnetic waves such as sunlight. In this way, a positive charge is also given to the contaminant (FIG. 7- (2)).

  An electrostatic repulsion between positive charges occurs between the surface of the substrate and the contaminant, and a repulsive separation force is generated in the contaminant. Thereby, the adhering force of the contaminant to the substrate surface is reduced (FIG. 7- (3)).

  Contaminants are easily removed from the substrate surface by physical action such as wind and rain (FIG. 7- (4)). Thereby, the substrate is self-cleaned.

  By applying a positive charge to the substrate surface as described above, adhesion of a positively charged contaminant to the substrate surface can be avoided.

  On the other hand, some of the pollutants are negatively charged such as chloride ions in tap water, or initially had a positive charge such as pollen and algae, but with other objects Some of them have negative charges due to interaction (friction, etc.). Therefore, by arranging a negative charge on the substrate surface (FIGS. 5B and 6B), it is possible to avoid the adhesion of the negatively charged contaminants to the substrate surface, as described above. .

  In the present invention, since the hydrophilic group on the surface of the substrate is present stably over a long period of time, raindrops, shower water, and various sprinklings can be used to quickly remove dirt and produce water droplets by the superhydrophilic antifogging effect. The absence of contamination can prevent contamination due to the presence of contaminants in the moisture. Further, the visual transparency can be maintained for a long time by the anti-fogging / anti-fouling effect. When water is present on the substrate surface, the removal of contaminants from the substrate surface is further facilitated.

  However, a contaminant made of an insulator (for example, silicone oil) having a relatively small amount of positive charge or negative charge may be contaminated depending on the type of the substance if only a strong positive charge or negative charge is present on the surface of the substrate. Since the surface charge of the substance is reversed and as a result, the contaminant may be adsorbed on the surface of the substrate, it is possible to avoid such adsorption by coexisting both positive and negative charges. it can.

  FIG. 8 shows a mechanism by which contaminants are removed from the surface of the substrate having a positive charge and a negative charge. In FIG. 7, the display of the hydrophilic group is omitted.

  In the embodiment shown in FIG. 8, positive and negative charges are imparted by arranging the positively charged substance and the negatively charged substance described above on the substrate surface or in the substrate surface layer (FIG. 8- (1)).

  Contaminants accumulate on the substrate surface and are continuously photooxidized by the action of electromagnetic waves such as sunlight. Thus, a positive charge is also given to the contaminant (FIG. 8- (2)).

  An electrostatic repulsion between positive charges occurs between the surface of the substrate and the contaminant, and a repulsive separation force is generated in the contaminant. Thereby, the adhering force of the contaminant to the substrate surface is reduced (FIG. 8- (3)).

  Contaminants are easily removed from the surface of the substrate by the physical action of water spray such as wind and rain, shower water, etc. (FIG. 8- (4)). Thereby, the substrate is self-cleaned.

  In the present invention, the hydrophilic group on the substrate surface is stably present for a long period of time, so that when water is present on the substrate surface due to rain water, various water sprays, etc., contaminants can be removed from the substrate surface. At the same time, it is possible to reduce water droplet trace contamination by the anti-fogging super hydrophilic property.

  Since the present invention can remove contaminants easily and over a long period of time without using artificial energy, it can be used in any field indoors and outdoors, such as glass, metal, ceramics, Concrete, wood, stone, polymer resin cover, polymer resin sheet, fiber (clothing, curtain, etc.), sealing agent, etc., or a combination thereof; building materials; air-conditioning outdoor units; kitchen equipment; sanitary equipment; lighting equipment; Bicycles; Motorcycles; Airplanes; Trains; Goods used indoors and outdoors, such as ships, and for various machines, electronic devices, television displays, face panels, optical devices, solar cells, etc. The In particular, it is suitable for face panels of equipment, mirrors for bathrooms, washrooms, etc., refrigerator door glass, windows for automobiles, transparent substrates, and mirrors, and naturally preferred for building members used indoors and outdoors. Buildings such as houses, buildings, roads, and tunnels, and civil engineering / workpieces constructed using the building members can exhibit high effects over time.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to an Example.

(Production Example 1)
30 g of methyl silicate 51 (manufactured by Mitsubishi Chemical Corporation), 60 g of methanol-modified alcohol (mixture of 88% by weight of ethanol, 5% by weight of methanol and 7% by weight of water), 5.7 g of pure water, and 0.3 g of acetylacetone aluminum By mixing and stirring for 24 hours while heating to 60 ° C., 96 g of a polysilicate liquid having a solid concentration of 16% by weight was produced.

(Production Example 2)
The polysilicate liquid 5.3g obtained in Preparation Example 1 was diluted with 94.7 g of pure water to produce 100 g of a polysilicate liquid having a solid content concentration of 0.85% by weight.

(Production Example 3)
A solution of CeCl ₃ · _7H 2 O (cerous chloride) 1.298G in pure water 1000g completely was further addition of 50% titanium tetrachloride solution (KK OSAKA Titanium Technologies) 20 g Pure water In addition, prepare a solution up to 2000 g. To this liquid, ammonia water diluted 10 times with 25% aqueous ammonia (manufactured by Takasugi Pharmaceutical Co., Ltd.) was added dropwise to adjust the pH to 7.0 to precipitate a mixture of cerium hydroxide and titanium hydroxide. This precipitate was washed with pure water until the conductivity of the supernatant liquid was 0.8 mS / m or less. When washing was completed when the electrical conductivity reached 0.679 mS / m, 650 g of a hydroxide dispersion having a concentration of 0.79% by weight was obtained. Next, 112 g of 35% by weight hydrogen peroxide (Taiki Pharmaceutical Co., Ltd.) was added to this solution at room temperature and stirred for 16 hours. 760 g of amorphous titanium peroxide solution was obtained.

(Positive charge imparting liquid)
Commercially available anatase type titanium peroxide dispersion (STi-Z18-1600: manufactured by Sustainable Technology Co., Ltd.) having a solid content concentration of 0.85% by weight and commercially available potassium doped polysilicate (MS-AAAL1K10: Sustainable Technology Co., Ltd.) )) Prepared with pure water to a solid content concentration of 0.85% by weight and mixed with a 1: 1 weight ratio, commercially available modified silicone (SH3746: manufactured by Toray Dow Corning Co., Ltd.) An amount of 0.1% by weight was added to obtain a positive charge imparting solution.

(Negative charge imparting liquid)
A commercially available modified silicone (SH3746: Toray Dow Corning) was mixed with the polysilicate solution obtained in Production Example 2 and the cerium-doped amorphous titanium peroxide solution obtained in Production Example 3 at a weight ratio of 1: 1. (Made by Co., Ltd.) was added in an amount of 0.1% by weight to give a negative charge imparting solution.

(Amphoteric charge imparting solution)
A commercially available silica-based positive charge-providing liquid (MS-AAAL1K10: manufactured by Sustainable Technology Co., Ltd.) was adjusted to a solid content concentration of 0.85% by weight with pure water and the cerium-doped amorphous type liquid obtained in Preparation Example 3 To a mixture of titanium oxide solution at a weight ratio of 1: 1, commercially available modified silicone (SH3746: manufactured by Toray Dow Corning Co., Ltd.) was added in an amount of 0.1% by weight, and did.

(Production Example 4)
100 g of commercially available modified silicone (SH3746: Toray Dow Corning Co., Ltd.) was diluted with 81 g of methanol-modified alcohol to produce 181 g of a modified silicone liquid having a solid content concentration of 50% by weight.

(Hydrogen peroxide solution)
A commercially available 35% by weight industrial hydrogen peroxide solution (manufactured by Taiki Pharmaceutical Co., Ltd.) was used as the hydrogen peroxide solution.

(Ammonia water)
Commercially available 25 wt% aqueous ammonia (manufactured by Takasugi Pharmaceutical Co., Ltd.) was diluted 10 times with ion-exchanged water to obtain 2.5 wt% ammonia water.

[Evaluation board 1]
A positive charge applying liquid is applied at a rate of 12 g / m ² on a blue float glass (thickness 3 mm) for building materials by a sponge squeegee coating method, dried at room temperature, and then heated at 500 ° C. for 15 minutes to form a positive charge layer (About 100 nm thick) was formed. Thereafter, the polysilicate liquid obtained in Preparation Example 1 was applied at a rate of ² to 3 g / m ² at room temperature, and after removing SiO ₂ with running water to form a hydrophilic group, drying was performed. Thereafter, hydrogen peroxide solution was applied by spraying at a rate of ² to 3 g / m ² , and then the same amount of ammonia water was applied, followed by drying at room temperature for 20 minutes to obtain an evaluation substrate 1.

[Evaluation board 2]
An evaluation substrate 2 was obtained by repeating the above production process of the evaluation substrate 1 except that the polysilicate liquid obtained in Production Example 1 was changed to the modified silicone liquid obtained in Production Example 4.

[Comparative board 1]
A comparative substrate 1 was obtained by repeating the above-described production process of the evaluation substrate 1 except that the application of hydrogen peroxide solution and the subsequent application of ammonia and room temperature drying were not performed.

[Comparison board 2]
A comparative substrate 2 was obtained by repeating the above production process of the evaluation substrate 1 except that the polysilicate liquid obtained in Production Example 1 was not applied and the subsequent running water treatment and drying were not performed.

[Comparative board 3]
A comparative substrate 3 was obtained by repeating the above manufacturing process of the evaluation substrate 2 except that the application of hydrogen peroxide solution and the subsequent application of ammonia and room temperature drying were not performed.

[Evaluation board 3]
On a building blue float glass (thickness 3 mm), an amphoteric charge imparting solution is applied at a rate of 12 g / m ² by a sponge squeegee coating method, dried at room temperature, heated at 500 ° C. for 15 minutes, positive and negative A charge layer (about 100 nm thick) was formed. Thereafter, the polysilicate liquid obtained in Preparation Example 1 was applied at a rate of ² to 3 g / m ² at room temperature, and after removing SiO ₂ with running water to form a hydrophilic group, drying was performed. Thereafter, hydrogen peroxide solution was applied by spraying at a rate of ² to 3 g / m ² , and then the same amount of aqueous ammonia was applied, followed by drying at room temperature for 20 minutes to obtain Evaluation substrate 3.

[Evaluation board 4]
An evaluation substrate 4 was obtained by repeating the above production process of the evaluation substrate 3 except that the polysilicate liquid obtained in Production Example 1 was changed to the modified silicone liquid obtained in Production Example 4.

[Comparison board 4]
A comparative substrate 4 was obtained by repeating the above-described manufacturing process of the evaluation substrate 3 except that the application of hydrogen peroxide solution and the subsequent application of ammonia and drying at room temperature were not performed.

[Comparison board 5]
A comparative substrate 5 was obtained by repeating the above production steps of the evaluation substrate 3 except that the polysilicate liquid obtained in Production Example 1 was not applied and the subsequent running water treatment and drying were not performed.

[Comparative board 6]
A comparative substrate 6 was obtained by repeating the above manufacturing process of the evaluation substrate 4 except that the application of hydrogen peroxide solution and the subsequent application of ammonia and room temperature drying were not performed.

[Evaluation board 5]
On a building blue float glass (thickness 3 mm), a negative charge applying liquid is applied at a rate of 12 g / m ² by a sponge squeegee coating method, dried at room temperature, and then heated at 500 ° C. for 15 minutes to form a negative charge layer (About 100 nm thick) was formed. Thereafter, the polysilicate liquid obtained in Preparation Example 1 was applied at a rate of ² to 3 g / m ² at room temperature, and after removing SiO ₂ with running water to form a hydrophilic group, drying was performed. Thereafter, hydrogen peroxide water was applied by spraying at a rate of ² to 3 g / m ² , and then the same amount of ammonia water was applied, followed by drying at room temperature for 20 minutes to obtain an evaluation substrate 5.

[Evaluation board 6]
An evaluation substrate 6 was obtained by repeating the above production process of the evaluation substrate 5 except that the polysilicate liquid obtained in Production Example 1 was changed to the modified silicone liquid obtained in Production Example 4.

[Comparative board 7]
A comparative substrate 7 was obtained by repeating the above-described manufacturing process of the evaluation substrate 5 except that the application of hydrogen peroxide solution and the subsequent application of ammonia and drying at room temperature were not performed.

[Comparative board 8]
A comparative substrate 8 was obtained by repeating the above production steps of the evaluation substrate 5 except that the polysilicate liquid obtained in Production Example 1 was not applied and the subsequent running water treatment and drying were not performed.

[Comparative board 9]
A comparative substrate 9 was obtained by repeating the above manufacturing process of the evaluation substrate 6 except that the application of hydrogen peroxide solution, the subsequent application of ammonia, and the drying at room temperature were not performed.

[Evaluation board 7]
Polish and clean the surface of a soda lime glass plate (thickness 3 mm) to remove and dry the deposits on the surface, then apply hydrogen peroxide solution at a rate of 2 to 3 g / m2 by spraying, dry the surface and then add ammonia. The same amount was applied and further dried at room temperature for 20 minutes to obtain an evaluation substrate 7.

[Evaluation board 8]
After cleaning the surface of the soda lime glass plate (thickness 3 mm) to remove the deposits on the surface and drying, after irradiating with UV light of 184.9 nm and 253.7 nm using PL16-11001D manufactured by Sen Engineering Co., Ltd. Then, a hydrogen peroxide solution was applied by spraying at a rate of ² to 3 g / m ² , and after drying the surface, the same amount of ammonia was applied, and further dried at room temperature for 20 minutes to obtain an evaluation substrate 8.

[Comparative board 10]
A comparative substrate 10 was obtained by repeating the above manufacturing process of the evaluation substrate 7 except that the application of the hydrogen peroxide solution and subsequent room temperature drying were not performed.

[Comparative board 11]
A comparative substrate 11 was obtained by repeating the above manufacturing process of the evaluation substrate 8 except that the application of hydrogen peroxide solution and subsequent drying at room temperature were not performed.

[Evaluation board 9]
After washing the surface of the polycarbonate plate (thickness 2 mm) to remove the deposits on the surface and drying it, spray it with UV light of 184.9 nm and 253.7 nm using PL16-11001D manufactured by Sen Engineering Co., Ltd. Then, a hydrogen peroxide solution was applied at a rate of ² to 3 g / m ² , and after drying the surface, the same amount of ammonia was applied, and further dried at room temperature for 20 minutes to obtain an evaluation substrate 9.

[Comparative board 12]
A comparative substrate 12 was obtained by repeating the above manufacturing process of the evaluation substrate 9 except that the application of hydrogen peroxide solution and subsequent room temperature drying were not performed.

(Evaluation 1)
About the evaluation board | substrates 1-9 and the comparison board | substrates 1-12, ion-exchange water was dripped on the surface, and the initial stage water contact angle was measured visually using the manual fraction angle meter. Next, after immersing the evaluation substrates 1 to 9 and the comparative substrates 1 to 12 in tap water, the operation of leaving them in a dark room for 24 hours was repeated 5 times, and each time manual polishing with wet waste was repeated 4 times. . Thereafter, ion-exchanged water was dropped on the surface, and the water contact angle was measured visually using a manual protractor angle meter. The results are shown in Tables 1-5.

(Evaluation 2)
About the evaluation board | substrates 1-9 and the comparison board | substrates 1-12, the average transmittance | permeability of visible light (380 nm-780 nm) was measured using the photometer V-550DS (JASCO Corporation). Next, after immersing the evaluation substrates 1 to 9 and the comparative substrates 1 to 12 in tap water, the operation of leaving them in a dark room for 24 hours was repeated 5 times, and each time manual polishing with wet waste was repeated 4 times. . Thereafter, similarly, the average transmittance of visible light (380 nm to 780 nm) was measured using a photometer V-550DS (JASCO Corporation). From the measurement result, the rate of change in average transmittance was calculated. The results are shown in Tables 1-5.

  In general, it can be said that the antifogging property is excellent when the water contact angle is 10 ° or less. Moreover, it can be said that antifouling property is excellent when the change rate of the visible light average transmittance is less than 3%. From Tables 1-5, the board | substrate which received the process corresponding to this invention can maintain hydrophilicity, even if the substrate surface receives the contact of a liquid thing and a solid substance, and was excellent in anti-fogging property and antifouling property It can be seen that On the other hand, the comparative substrate that has not been subjected to the oxidation / basification treatment or the treatment with the polysilicate liquid or the modified silicone liquid has the hydrophilicity of the substrate surface decreased due to contact with the liquid / solid matter over time, It turns out that antifogging property and antifouling property deteriorate. Therefore, the substrate subjected to the treatment method of the present invention can exhibit excellent antifogging properties and antifouling properties even when used for a long time.

  In addition, in the oxidation treatment, it was confirmed that even when hydrogen peroxide solution and ammonia were mixed and used at the same time, it was effective in maintaining the hydrophilic surface for a long time. Further, it has been found that it is preferable to heat at about 80 ° C. to 300 ° C. for long-term maintenance of the hydrophilic surface.

Claims (14)

A method for maintaining hydrophilicity of a surface of a substrate having a hydrophilic surface, comprising a step of treating the hydrophilic surface with an oxidizing agent. The method of claim 1, further comprising treating the hydrophilic surface with a base. The method according to claim 1, wherein the hydrophilic surface has at least one hydrophilic group. The method according to claim 3, wherein the hydrophilic group is a silicon atom-bonded hydroxyl group and / or a silicon atom-bonded polyether group. The method according to any one of claims 1 to 4, further comprising the step of forming the hydrophilic surface by applying silanol, polysilicate, hydroxyl group-modified silicone and / or polyether-modified silicone to the surface of the substrate. 6. The method of claim 5, further comprising disposing a positively charged material and / or a negatively charged material on the surface of the substrate prior to the step of forming the hydrophilic surface. The method according to claim 1, wherein the substrate includes a positively charged substance and / or a negatively charged substance. The positively charged substance is (1) a cation;
7. A positively charged conductor or dielectric; and (3) one or more selected from the group consisting of a composite of positively charged conductor and dielectric or semiconductor. Or the method of 7. The negatively charged substance is (4) an anion;
(5) a negatively charged conductor or dielectric;
(6) A composite of a conductor having a negative charge and a dielectric or semiconductor; and (7) one or more selected from the group consisting of substances having a photocatalytic function. Method. A method for producing a substrate having a long-term antifogging property or a long-term antifouling property, comprising a step of treating the surface of a substrate having a hydrophilic surface with an oxidizing agent. The manufacturing method of Claim 10 which further includes the process of processing the said hydrophilic surface with a base. A substrate having a long-term antifogging property or a long-term antifouling property having a hydrophilic surface treated with an oxidizing agent. 13. A substrate according to claim 12, wherein the hydrophilic surface is further treated with a base. A laminated structure having a long-term antifogging property or a long-term antifouling property, comprising a positively charged substance and / or a negatively charged substance-containing layer on a substrate and a hydrophilic substance layer treated with at least an oxidizing agent.

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