JP2008112705A - Dye-sensitization solar cell and construction board provided with solar cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dye-sensitization solar cell that prevents deterioration in power-generation performance or in transparency while preventing dirt from adhering to its surface. <P>SOLUTION: The dye-sensitization solar cell is formed by providing transparent electrodes 22, 23, an electrolyte layer 24, and a particle film 26 between a pair of oppositely-arranged transparent substrates 20, 21. A photocatalytic function layer 13 is provided on the surface of at least one transparent substrate 20. The photocatalytic function layer 13 decomposes dirt such as organic substances adhering to its surface so as to facilitate the run-off of dirt by rain water or the like. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a dye-sensitized solar cell for performing photovoltaic power generation and a building board with solar cell used as an exterior material or interior material of a building.

  Conventionally, solar power generation has been performed by providing solar cells on the roof of a building. Recently, a dye-sensitized solar cell having transparency has been developed, and it has also been proposed to increase the amount of power generation by increasing the amount of solar cell used by applying it to a window glass of a building. (For example, refer to Patent Document 1).

However, there has been a problem that the solar cell has dirt on its surface due to long-term use (especially when used outdoors) and is not irradiated with sufficient light, resulting in a decrease in power generation performance. Further, when a dye-sensitized solar cell is used for a window glass, the transparency may be lowered due to adhesion of dirt, and the function as a window may be lowered. Moreover, the window glass has a small proportion of the building, and even if a dye-sensitized solar cell is applied thereto, a large increase in power generation could not be expected.
JP 2001-320068 A

  The present invention has been made in view of the above points, and is characterized by providing a dye-sensitized solar cell capable of preventing dirt from being attached to the surface and preventing a decrease in power generation performance and transparency. To do. In addition, the present invention can be used in various places of a building, can increase the amount of power generation per building, and can prevent the design of the building from being impaired. Is intended to provide.

  The dye-sensitized solar cell 4 according to claim 1 of the present invention is formed by including transparent electrodes 22, 23, an electrolyte layer 24, and a particle film 26 between a pair of transparent substrates 20, 21 arranged opposite to each other. In the dye-sensitized solar cell, the photocatalytic function layer 13 is provided on the surface of at least one transparent substrate 20.

  The building board A with a solar cell according to claim 2 of the present invention is the surface side of the building board 3 so that the dye-sensitized solar cell 4 according to claim 1 is positioned outward. It is characterized by being provided in.

  The building board A with a solar cell according to claim 3 of the present invention is characterized in that, in claim 2, the photocatalytic functional layer 13 is an inorganic coating film.

  The building board A with a solar cell according to claim 4 of the present invention is characterized in that, in claim 2 or 3, an inorganic ultraviolet absorbing layer 14 is provided between the transparent substrate 20 and the photocatalytic functional layer 13. Is.

  The building board A with solar cell according to claim 5 of the present invention is the building board A with solar cell according to any one of claims 2 to 4, wherein the dye-sensitized solar cell 4 has transparency and has a makeup 2 on the surface of the building board 3. It is characterized by comprising.

  In the dye-sensitized solar cell 4 according to claim 1, the photocatalyst functional layer 13 can decompose dirt such as organic matter attached to the surface thereof, and can easily flow down with rainwater or the like, and the surface of the transparent substrate 20 is hardly stained. As a result, the particle film 26 and the electrolyte layer 24 of the dye-sensitized solar cell 4 are sufficiently irradiated with light to prevent a decrease in power generation performance. It is something that can be done.

  The building board A with a solar cell according to claim 2 can be used as an exterior material or an interior material in various places of a building, compared to a case where the dye-sensitized solar cell 4 is used only for a window glass of a building. The amount of dye-sensitized solar cell 4 used per unit can be increased, and the amount of power generation can be increased. Moreover, the surface of the building board 3 can be visually recognized through the dye-sensitized solar cell 4, and the design of the building can be prevented from being impaired.

  Since the photocatalyst functional layer 13 is an inorganic coating film, the building board A with a solar cell according to claim 3 has little deterioration of the antifouling function and can maintain the function over a long period of time.

  The building board A with a solar cell according to claim 4 can absorb ultraviolet rays by the ultraviolet absorbing layer 14, prevent fading of the building board 3, and prevent deterioration in design.

  The building board A with a solar cell according to claim 5 can see the makeup 2 on the surface of the building board 3 through the dye-sensitized solar cell 4 and can improve the design of the building. It is.

  Hereinafter, the best mode for carrying out the present invention will be described.

  The dye-sensitized solar cell 4 of the present invention is a photoelectric conversion element, and as shown in FIG. 1, a pair of transparent substrates 20 and 21 disposed opposite to each other with a spacer 29 interposed therebetween, and the transparent substrates 20 and 21. Transparent electrodes 22, 23 disposed on the opposite surface of each other, electrolyte layer 24 filled between the transparent electrodes 22, 23, and particles disposed between one transparent electrode 22 (23) and the electrolyte layer 24 The film 26 and the photocatalytic function layer 13 formed on the surface of the transparent substrate 20 can be provided.

  As the transparent substrates 20 and 21, a glass plate, a plastic plate, a plastic film, or the like can be used. Examples of the plastic include polyethylene terephthalate, triacetyl cellulose, polyethylene naphthalate, syndiotactic polystyrene, polyphenylene sulfide, polycarbonate, polyarylate, polysulfone, polyester sulfone, polyimide, polyetherimide, cyclic polyolefin, brominated phenoxy, and the like. Is mentioned. As the transparent electrodes 22 and 23, a fluorine-doped tin oxide film (FTO), an indium tin oxide film (ITO), gold, silver, aluminum, indium, tin oxide, or the like is deposited on the transparent substrates 20 and 21. Can be formed. Further, a metal layer 28 such as platinum or gold can be provided on the surface of one transparent electrode 22 (or 23).

  The electrolyte used in the electrolyte layer 24 is not particularly limited as long as a pair of redox constituents composed of an oxidant and a reductant are contained in the solvent, but the oxidant and the reductant have the same charge. Redox constituents are preferred. A redox-system constituent substance is a pair of substances that reversibly exist in the form of an oxidant and a reductant in a redox reaction. Such redox constituents are known to those skilled in the art. The oxidation-reduction constituents are, for example, chlorine compound-chlorine, iodine compound-iodine, bromine compound-bromine, thallium ion (III) -thallium ion (I), mercury ion (II) -mercury ion (I), ruthenium. Ion (III) -ruthenium ion (II), copper ion (II) -copper ion (I), iron ion (III) -iron ion (II), vanadium ion (III) -vanadium ion (II), manganate ion -Permanganate ion, ferricyanide-ferrocyanide, quinone-hydroquinone, fumaric acid-succinic acid and the like. Needless to say, other redox constituents can also be used. Among them, iodine compound-iodine is preferable. Examples of the iodine compound include metal iodides such as lithium iodide, potassium iodide, copper iodide, and silver rubidium iodide, and iodides 4 such as tetraalkylammonium iodide and pyridinium iodide. Particularly preferred are diimidazolium iodide compounds such as quaternary ammonium salt compounds and dimethylpropylimidazolium iodide. In addition, the solvent used for dissolving the electrolyte is preferably a compound that dissolves the redox constituent and has excellent ion conductivity. As the solvent, any of an aqueous solvent and an organic solvent can be used, but an organic solvent is preferable in order to make the redox constituent material more stable. For example, carbonate compounds such as dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, ethylene carbonate, propylene carbonate, ester compounds such as methyl acetate, methyl propionate, gamma-butyrolactone, diethyl ether, 1,2-dimethoxyethane, 1, Ether compounds such as 3-dioxosilane, tetrahydrofuran and 2-methyl-tetrahydrafuran, heterocyclic compounds such as 3-methyl-2-oxazodilinone and 2-methylpyrrolidone, nitrile compounds such as acetonitrile, methoxyacetonitrile and propionitrile, sulfolane And aprotic polar compounds such as didimethyl sulfoxide and dimethylformamide, and water. These can be used alone or in combination of two or more. Of these, carbonate compounds such as ethylene carbonate and propylene carbonate, heterocyclic compounds such as 3-methyl-2-oxazozirinone and 2-methylpyrrolidone, and nitrile compounds such as acetonitrile, methoxyacetonitrile and propionitrile are particularly preferable. As the electrolyte layer 24, any of liquid, solid, or gel electrolyte can be used. As the electrolyte solution for forming the electrolyte layer 24, a solution obtained by dissolving tetrapropylammonium iodide and iodine in a mixed solution of ethylene carbonate and acetonitrile can be used.

The particle film 26 can be formed by filling semiconductor fine particles 27 such as titanium oxide on which a dye 25 such as a ruthenium complex is adsorbed. In addition to the above, examples of the dye 25 include azo dyes, quinone dyes, quinone imine dyes, quinacridone dyes, squarylium dyes, cyanine dyes, merocyanine dyes, triphenylmethane dyes, xanthene dyes, porphyrins. Dyes, phthalocyanine dyes, perylene dyes, indigo dyes, and naphthalocyanine dyes. Among these, metal complex dyes such as phthalocyanine dyes and naphthalocyanine dyes are suitable for photoelectric conversion materials because they have a high quantum yield and good durability against light. Examples of the metal complex dye include copper, nickel, iron, cobalt, vanadium, tin, silicon, titanium, germanium, cobalt, zinc, ruthenium, magnesium, aluminum, lead, manganese, indium, molybdenum, zirconium, antimony, tungsten, Metals such as platinum, bismuth, selenium, silver, cadmium and platinum are used. Among these, metal complex dyes such as copper, titanium, zinc, aluminum, iron, vanadium, and silicon have high quantum efficiency. As the semiconductor fine particles 27, in addition to the above, for example, zinc oxide, manganese oxide, cadmium oxide, indium oxide, lead oxide, molybdenum oxide, tungsten oxide, antimony oxide, bismuth oxide, copper oxide, mercury oxide, silver oxide, manganese oxide Metal oxides such as iron oxide, vanadium oxide, tin oxide, zirconium oxide, strontium oxide, gallium oxide, silicon oxide, chromium oxide, perovskites such as SrTiO ₃ , CaTiO ₃ , cadmium sulfide, zinc sulfide, Metal sulfides such as indium sulfide, lead sulfide, molybdenum sulfide, tungsten sulfide, antimony sulfide, bismuth sulfide, cadmium zinc sulfide, copper sulfide, etc., metal chalcogenides of CdSe, In ₂ Se ₃ , WSe ₂ , HgS, PbSe, CdTe Others, GaAs _{Si, Se, Cd 2 P 3} , Zn 2 P 3, InP, AgBr, include _{PbI 2, HgI 2, BiI 3} . A composite containing at least one selected from the semiconductors can also be used. Among these, anatase-type titanium oxide fine particles that are particularly inexpensive and excellent in performance are preferable. As a trade name of titanium oxide, for example, AMT-600 (trade name, anatase type, average particle diameter 30 nm, manufactured by Teika Co., Ltd.), AMT-100 (trade name, anatase type, primary average particle, manufactured by Teica Corporation). ST-01 (Ishihara Techno, product name, anatase type, primary average particle size 7 nm), ST-21 (Ishihara Techno, product name, anatase type, primary average particle size 20 nm), P- 25 (manufactured by Nippon Aerosil Co., Ltd., trade name, rutile-anaters type crystal, primary average particle diameter of about 30 nm). The primary average particle diameter of the semiconductor fine particles 27 is, for example, in the range of 1 nm to 1000 nm, 15 nm to 100 nm. If the particle diameter of the semiconductor fine particles 27 is smaller than 1 nm, the pore diameter of the particle film 26 becomes small, the movement of the redox substance in the electrolyte solution becomes difficult, and the current value after photoconversion becomes low. Further, when the primary average particle diameter of the semiconductor fine particles 27 is larger than 1000 nm, since the surface area of the particle film 26 is not large, a sufficient amount of sensitizing dye cannot be obtained, and thus the current value after light conversion is high. It is not preferable because it does not become. The amount of the dye 25 supported on the semiconductor fine particles 27 is preferably 10 ⁻⁸ to 10 ⁻⁶ mol / cm ² , particularly preferably 0.1 to 9.0 × 10 ⁻⁷ mol / cm ² . The film thickness of the particle film 26 is 0.01 μm to 100 μm, preferably 1 μm to 50 μm.

In the present invention, the photocatalytic functional layer 13 is a transparent (clear) photocatalyst-containing inorganic coating (ceramic coat), and the inorganic coating agent for forming the coating is not particularly limited. It is preferable to use a blended silicone-based coating agent. As this silicone type coating agent, what is disclosed by patent 2767259 can be used, for example. That is,
General formula: Si (OR ¹ ) ₄ (1)
20 to 200 parts by weight of colloidal silica having an organic solvent dispersibility in which the silicon compound and / or colloidal silica is dispersed in a non-aqueous organic solvent,
General formula: R ² Si (OR ¹ ) ₃ (2)
100 parts by weight of a silicon compound represented by
General formula: R ² ₂ Si (OR ¹ ) ₂ (3)
And a photocatalyst-containing coating (in the above formulas (1) to (3), R ¹ and R ² represent a monovalent hydrocarbon group). An agent can be used.

Each silicon compound has a general formula represented by the following formula (4).
General formula: R ² nSi (OR ¹ ) _4-n (4)
(In formula (4), n = 0 to 3 is shown, and R ¹ and R ² are monovalent hydrocarbon groups.)
R ¹ and R ^{2 in} formula (4) are not limited as long as they represent a monovalent hydrocarbon group, but R ² represents a substituted or unsubstituted hydrocarbon group having 1 to 8 carbon atoms. For example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group and other alkyl groups, cyclopentyl group, cyclohexyl group and other cycloalkyl groups, 2-phenylethyl group, 3-phenylpropylene. Halogens such as aralkyl groups such as ruthel groups, aryl groups such as phenyl and tolyl groups, anikenyl groups such as vinyl and allyl groups, chloromethyl groups, γ-chloropropyl groups, and 3,3,3-trifluoropropyl groups Examples thereof include substituted hydrocarbon groups and substituted hydrocarbon groups such as γ-methacryloxypropyl group, γ-glycidoxypropyl group, 3,4-epoxycyclohexylethyl group, and γ-mercaptopropyl group. Among these, an alkyl group having 1 to 4 carbon atoms and a phenyl group are preferable because of ease of synthesis or availability.

As R ¹ in the above formula (4), ^one having an alkyl group having 1 to 4 carbon atoms as a main raw material is used. In particular, tetramethoxysilane, tetraethoxysilane and the like are exemplified as the tetraalkoxysilane of n = 0, and methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane are exemplified as the organotrialkoxysilane of n = 1. , Phenyltrimethoxysilane, phenyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane and the like. Further, examples of the n = 2 diorganodialkoxysilane include dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, methylphenyldimethoxysilane, and the like, and n = 3 triorganoalkoxysilane. Examples thereof include trimethylmethoxysilane, trimethylethoxysilane, trimethylisopropoxysilane, dimethylisobutylmethoxysilane and the like.

R ¹ and R ^{2 in the} above formulas (1), (2), and (3) may be the same hydrocarbon group or different.

  Preparation of the silicone-based coating agent includes, for example, diluting a silicon compound represented by the above formulas (1), (2), and (3) with a solvent, adding water or a catalyst as a curing agent, hydrolysis, and It is prepared by performing a polycondensation reaction. The weight average molecular weight (Mw) of these silicon compounds is calculated in terms of polystyrene. In this preparation, it is preferable that the weight average molecular weight (Mw) of the inorganic coating is 900 or more in terms of polystyrene. When the weight average molecular weight (Mw) is less than 900 in terms of polystyrene, curing shrinkage increases during the polycondensation reaction, and cracks are likely to occur in the baked inorganic coating film.

  The silicone-based coating agent can be used in combination with the silicon compound represented by the above formula (1), or alternatively, colloidal silica as a component. The colloidal silica is an organic solvent-dispersible colloidal silica dispersed in a non-aqueous organic solvent such as alcohol. The colloidal silica contains 20 to 50% by weight of silica as a solid content. The organic solvent-dispersible colloidal silica can be easily prepared by replacing the organic solvent with water. Examples of the organic solvent in which the colloidal silica is dispersed include, for example, lower aliphatic alcohols such as methanol, ethanol, isopropanol, n-butanol, and isobutanol, ethylene glycol, ethylene glycol monobutyl ether, and ethylene glycol monoethyl ether acetate. And ethylene glycol derivatives, diethylene glycol derivatives such as diethylene glycol and diethylene glycol monobutyl ether, and diacetone alcohol. One or more of these are used. Furthermore, toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, methyl ethyl ketoxime, etc. can be used in combination with a hydrophilic organic solvent. In addition, the said compounding quantity of the said colloidal silica is a weight also including a dispersion medium.

  Water is generally used as a curing agent in preparing the silicone coating agent, and the amount of this water is preferably 45% by weight or less, more preferably 25% by weight or less in the silicone coating agent.

  Examples of the organic solvent used in preparing the silicone coating agent include lower aliphatic alcohols such as methanol, ethanol, isopropanol, n-butanol, and isobutanol, ethylene glycol, ethylene glycol monobutyl ether, and ethylene glycol monoethyl acetate. Examples thereof include ethylene glycol derivatives such as ether, diethylene glycol derivatives such as diethylene glycol and diethylene glycol monobutyl ether, and diacetone alcohol. One or more of these are used. Furthermore, toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, methyl ethyl ketoxime, etc. can be used in combination with a hydrophilic organic solvent.

  When preparing a silicone type coating agent, it is desirable to set pH of a silicone type coating agent to 3.8-6. Within this pH range, the preservability of the silicone-based coating agent is good, and when it is outside this pH range, the period during which application can be performed is limited. The method for adjusting the pH is not limited. For example, when the pH is less than 3.8 when the materials are mixed, the pH may be adjusted by adding a basic reagent such as ammonia. In this case, an acid reagent such as hydrochloric acid may be added for adjustment. Depending on the pH, if the reaction progresses slowly with a small molecular weight, the reaction may be promoted by heating, or after the reaction is advanced by lowering the pH with an acidic reagent, a basic reagent is added. It may be a predetermined pH.

  The silicone-based coating agent can be used as a photocatalytic silicone-based coating agent by containing a photocatalyst. Generally, titanium oxide is used as the photocatalyst. Zinc oxide, tin oxide, iron oxide, zirconium oxide, tungsten oxide, chromium oxide, molybdenum oxide, ruthenium oxide, germanium oxide, lead oxide, cadmium oxide, copper oxide, vanadium oxide, niobium oxide, tantalum oxide, manganese oxide, Cobalt oxide, rhodium oxide, rhenium oxide and the like can also be mentioned. Although the compounding quantity of a photocatalyst is not specifically limited, The range of 20 to 80 weight% is preferable with respect to the dry solid content of a silicone type coating agent.

  And the photocatalyst functional layer 13 can be formed by apply | coating said photocatalyst containing silicone type coating agent on the surface of the transparent substrate 20, and making it harden by drying. The coating agent can be applied by various methods such as brush coating method, dipping method, spray coating method, roll coating method, bell method, flow coating method, curtain coating method, knife coating method, etc., but with a uniform thickness. In order to easily obtain the coating film, it is preferable to apply by a spray coating method, a roll coating method, or a bell method using a rotating cup. By forming the coating film with a uniform thickness in this way, it is possible to obtain a uniform elongation at break of the coating film. The film thickness of the photocatalytic function layer 13 is preferably in the range of 0.1 to 2 μm. The photocatalytic functional layer 13 may be provided not only on one transparent substrate 20 but also on the surface of the other transparent substrate 21.

  The dye-sensitized solar cell 4 has transparency and preferably has a visible light transmittance of 20% or more. If the visible light transmittance of the dye-sensitized solar cell 4 is less than 20%, the makeup 2 of the substrate 1 cannot be seen through the dye-sensitized solar cell 4, and the solar cell of the present invention. When the attached building board A is constructed, design properties such as the appearance of the building are impaired. Further, the visible light transmittance of the dye-sensitized solar cell 4 is preferably higher for visually recognizing the makeup 2 of the base material 1, but if it is too high, the power generation efficiency is lowered, so that the dye-sensitized solar cell is reduced. The visible light transmittance of 4 is preferably 80% as an upper limit. Here, when the visible light transmittance of the dye-sensitized solar cell 4 is 20% or more and 50% or less, the dye-sensitized solar cell 4 acts like a ground glass. The blurring effect of the makeup 2 can improve the design of the building when the building board A with solar cells of the present invention is applied. it can. In addition, when the visible light transmittance of the dye-sensitized solar cell 4 is larger than 50%, the makeup 2 of the substrate 1 can be clearly and clearly seen through the dye-sensitized solar cell 4. Thus, a deep feeling can be obtained in the makeup 2, and when the building board A with solar cells of the present invention is constructed, the design of the building can be improved. In the present invention, the visible light transmittance can be measured using a UV-VIS spectrophotometer or the like.

  The building board 3 is conventionally used as an interior material such as an exterior material such as an outer wall material (outer wall panel) or an inner wall material (inner wall panel), and has a plate-like base material 1 with a makeup 2 on the surface. Can be used. As the base material 1, it is possible to use a ceramic base material (inorganic hardened body) mainly composed of cement, a resin base material mainly composed of a resin, or a wooden base material. it can. Further, a multi-color or single-color coating film 10 (thickness of 0.1 to 100 μm) is formed on the surface of the base material 1 by forming a concave / convex pattern 5 composed of convex portions 5a and concave portions 5b, or by ink-jet coating on the surface of the base material 1 A wide range of makeup 2 can be applied to the surface of the substrate 1 by coloring the substrate 1 itself with a pigment or the like.

  In the present invention, the lightness (L value) of the surface of the building board 3 is preferably 50 or more as measured by a color measuring device (for example, CR-400 manufactured by Konica Minolta). The “L value” is a value in the “L * a * b * color system”. If the value of brightness is smaller than this, the reflection of light on the surface of the building board 3 is small, and the power generation amount of the dye-sensitized solar cell 4 is difficult to increase. In order to set the lightness of the surface of the building board 3 to 50 or more, for example, when the makeup 2 is a color that easily reflects light or a substance that easily reflects light, the light reflected by the makeup 2 is dyed. Inputting to the sensitized solar cell 4 from the back surface can improve power generation efficiency. Therefore, the brightness of the surface of the building board 3 is set to 50 or more by making the base material 1 and the coating film 10 white by adding pigments and the like, and the base material 1 and the coating film 10 are moved to the dye-sensitized solar cell 4 side. Light can be easily reflected. Further, by adding a bright material (reflecting material) such as mica to the base material 1 or the coating film 10, the base material 1 or the coating film 10 can easily reflect light toward the dye-sensitized solar cell 4 side. preferable. Furthermore, by forming the concave / convex pattern 5 on the surface of the base material 1, the light reflection area is increased, so that light is easily reflected toward the dye-sensitized solar cell 4 side. The upper limit of the lightness of the surface of the building board 3 is not particularly limited, but is 100 because it is preferable as the reflection of light increases. Further, a real part 11 projects from the lower end of the base material 1 and a real receiving part 12 projects from the upper end of the base material 1.

  And the building board A with a solar cell of this invention as shown in FIG. 1 is arrange | positioned by arrange | positioning the dye-sensitized solar cell 4 to the surface side (surface side which gave the makeup | decoration 2) of said building board 3. As shown in FIG. Can be formed. In disposing the dye-sensitized solar cell 4 on the surface side of the building board 3, various methods can be employed. For example, the dye-sensitized solar cell 4 is attached to the surface of the building board 3 with an adhesive. Adhering, fixing the dye-sensitized solar cell 4 to the building board 3 with screws or screws, or providing a frame material or locking metal on the surface of the building board 3 to increase the dye on the frame or locking metal The sensitive solar cell 4 can be held. Here, when the coating film 10 is formed on the surface of the substrate 1, the dye-sensitized solar cell 4 can be provided in close contact with the surface of the coating film 10, and the coating film is formed on the surface of the substrate 1. When 10 is not formed, the dye-sensitized solar cell 4 can be provided in close contact with the surface of the substrate 1. Further, the surface of the dye-sensitized solar cell 4 to be brought into close contact with the surface of the coating film 10 or the base material 1 is the surface of the transparent substrate 21 on which the photocatalytic function layer 13 is not provided. The photocatalytic functional layer 13 is located outside the plate A (outermost surface). In addition, the dye-sensitized solar cell 4 may be provided with a slight gap as well as the case where the dye-sensitized solar cell 4 is closely attached to the surface of the coating film 10 or the substrate 1.

  The building board A with solar cells of the present invention is, for example, arranged by arranging the real part 11 on the surface side of the actual receiving part 12 and arranging a plurality of building boards A, A ... with solar cells side by side. A wall such as an outer wall or an inner wall of a building can be formed. Since the dye-sensitized solar cell 4 is provided on the surface of the wall, power can be generated by irradiating the dye-sensitized solar cell 4 with sunlight, illumination light, or the like. Therefore, the amount of the dye-sensitized solar cell 4 used per building is smaller than when a solar cell is disposed only on the roof as in a conventional building or when a dye-sensitized solar cell is disposed on a window glass. It can be increased and the amount of power generation can be increased. Moreover, the makeup | decoration 2 of the surface of the base material 1 can be seen through the dye-sensitized solar cell 4 and can be made visible so that the design of the building is not impaired. There is no sense of incongruity even when used.

  Since the dye-sensitized solar cell 4 of the present invention includes the photocatalyst functional layer 13 on the outermost surface, the photocatalyst contained in the photocatalyst functional layer 13 is activated by irradiation with ultraviolet rays, and the photocatalyst functional layer 13 The dirt adhered to the surface can be decomposed, and the decomposed dirt for making the surface of the photocatalytic functional layer 13 hydrophilic can be washed away with rainwater, etc., and a self-cleaning effect can be obtained. Is. Therefore, the surface of the transparent substrate 20 of the dye-sensitized solar cell 4 is less likely to become dirty, and a decrease in transparency can be prevented. As a result, the particle film 26 and the electrolyte of the dye-sensitized solar cell 4 can be prevented. The layer 24 can be sufficiently irradiated with light to prevent a decrease in power generation performance.

  The dye-sensitized solar cell 4 of the present invention can be used, for example, as an auxiliary power source for outdoor lights, street lights, security lights, decorative lamps, or roof ventilation systems.

  FIG. 3 shows a dye-sensitized solar cell 4 according to another embodiment of the present invention. This dye-sensitized solar cell 4 is provided with an ultraviolet absorbing layer 14 which is a transparent (clear) inorganic coating film (ceramic coat) between a transparent substrate 20 and a photocatalytic functional layer 13, and other configurations. Is similar to that of FIG. The ultraviolet absorbing layer 14 can be formed using two types of silicone-based coating agents disclosed in JP-A-9-249822.

One of the two types of silicone coating agents (hereinafter referred to as silicone coating agent (1))
General formula (R ¹ ) _m Si (OR ² ) _4-m (5)
(In Formula (5), R1 represents a methyl group, an ethyl group, or a phenyl group, respectively, R2 represents a C1-C8 alkyl group. M is 0, 1 or 2.)
An ultraviolet absorber is blended with a silicon alkoxide-based coating agent mainly composed of a silicon compound represented by formula (1) and / or a partial hydrolyzate thereof.

The silicon alkoxide mainly composed of the silicon compound represented by the general formula (5) and / or a partial hydrolyzate thereof is a mixture mainly composed of the following compounds (i), (ii) and (iii): Can be obtained by diluting with an appropriate solvent, adding a necessary amount of a curing agent and a catalyst, followed by hydrolysis and condensation polymerization, having a weight average molecular weight Mw of 500 to 3000 in terms of polystyrene, and a molecular weight distribution Mw / Mn ( Mn preferably has a number average molecular weight) of 1.1 to 3.0. More preferably, Mw = 600 to 3000 and Mw / Mn = 1.2 to 1.8. When the weight average molecular weight and the molecular weight distribution are smaller than these ranges, the curing shrinkage during the condensation polymerization becomes large, and cracks tend to occur in the coating film after baking. Also, when the weight average molecular weight and molecular weight distribution are larger than this range, the reaction is too slow to be hardened, or even when cured, the film tends to be soft or the leveling property of the film becomes very poor. There is.
(I): silicon compound represented by m = 0 in the general formula (5) and colloidal silica 20
-200 parts by weight (ii): 100 parts by weight of a silicon compound represented by m = 1 in the general formula (5) (iii): 0-80 parts by weight of a silicon compound represented by m = 2 in the general formula (5) As the silicon compound, alkoxysilanes in the later-described formula (6) can be used. Further, the component (i) colloidal silica (colloidal silica) is used by dispersing the fine particle silica component in water, an organic solvent such as methanol, or a mixed solvent thereof, as long as they are colloidal. There are no particular restrictions on the solvent type. In addition, the compounding quantity of the colloidal silica of a component (i) is a weight part also including a dispersion medium.

  Although it does not specifically limit as said hardening | curing agent used as needed in silicone type coating agent (1), For example, inorganic acids, such as hydrochloric acid, phosphoric acid, a sulfuric acid, formic acid, an acetic acid, chloroacetic acid An acidic catalyst such as a dilute solution of an organic acid such as a basic catalyst described later can be used alone or in combination of two or more. Further, when colloidal silica is used as the component (i), the colloidal silica exhibits acidity, so that it becomes a catalyst, and nothing is required as an acidic catalyst.

  As the catalyst used as necessary in the silicone-based coating agent (1), a basic catalyst is used. The basic catalyst is not particularly limited. For example, amines such as triethanolamine; γ-aminopropyltriethoxysilane, N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane, etc. Aminosilanes; salts of inorganic acids (eg, hydrochloric acid, nitric acid, phosphoric acid, etc.) or organic acids (eg, formic acid, acetic acid, propionic acid, etc.), such as ammonia, trimethylamine, triethylamine, n-butylamine, or inorganic or organic acids Examples thereof include metathesis salts of salts and quaternary ammonium salts. These types and addition amounts are not limited at all.

  In addition to the above-mentioned components, the silicone-based coating agent (1) may optionally contain a filler other than colloidal silica (for example, inorganic filler such as alumina sol or fumed silica), a colorant, a diluting solvent, a thickening agent. One or more kinds of various additives such as an agent and a surfactant can be blended. Although it does not specifically limit as this dilution solvent, For example, alcohols, such as methanol, ethanol, isopropanol (IPA); Cellosolves, such as ethylene glycol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, etc. can be mentioned, These are 1 type or Two or more kinds can be used in combination.

  The silicone-based coating agent (1) can be stably used within the aforementioned molecular weight range by adjusting its pH value to 3.8 to 6.0. If the pH value is outside this range, the silicone-based coating agent (1) becomes less stable, and the usable period after preparing the silicone-based coating agent (1) may be limited. Here, the pH value adjusting method is not particularly limited. For example, when the pH value is less than 3.8 when the raw material of the silicone-based coating agent (1) is mixed, the predetermined range is determined using a basic reagent such as ammonia. What is necessary is just to adjust to the inside pH value, and what is necessary is just to adjust to the said predetermined range using acidic reagents, such as hydrochloric acid, when pH value exceeds 6.0. Also, depending on the pH value, the reaction does not proceed conversely with a small molecular weight, and when it takes time to reach the molecular weight range, the silicone coating agent (1) is heated to promote the reaction. Alternatively, the pH value may be lowered with an acidic reagent and the reaction may be advanced, and then returned to a predetermined pH value with a basic reagent.

  Even when the pH value is adjusted as described above, or even when the pH value is not adjusted, the condensation reaction is promoted by adding a basic catalyst to the silicone-based coating agent (1) during use or at least during use. Since the number of crosslinking points in the coating film can be increased, it is possible to stably obtain a coating film having good crack resistance. Further, by promoting the crosslinking reaction, the curing time can be shortened or the curing temperature can be lowered, which is economical.

Of the two types of silicone coating agents disclosed in JP-A-9-249822, the other silicone coating agent (hereinafter referred to as silicone coating agent (2)) is:
General formula (R ³ ) _n SiX _4-n (6)
(In Formula (6), R3 represents a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, X represents a hydrolyzable group, and n is an integer of 0 to 3.)
A silica-dispersed oligomer solution of organosilane (A) obtained by partially hydrolyzing the hydrolyzable organosilane represented by the formula (I), in colloidal silica dispersed in an organic solvent and / or water;
Average composition formula (R ⁴ ) _d Si (OH) _e O _{(4-de) / 2} (7)
(In formula (7), R ⁴ represents a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, and d and e are 0.2 ≦ d ≦ 2.0 and 0.0001 ≦, respectively. (a number satisfying the relationship of e ≦ 3 and d + e <4.)
A polyorganosiloxane (B) containing a silanol group in the molecule represented by:
Of the curing catalyst (C),
An ultraviolet absorber is blended with a silicon alkoxide coating agent containing the three components (A), (B), and (C) as essential components.

  The silica-dispersed oligomer of component (A) used in the silicone-based coating agent (2) is a main component of a base polymer having a hydrolyzable group X as a functional group that is subjected to a curing reaction during film formation. This is achieved by adding one or more hydrolyzable organosilanes represented by the above general formula (7) to colloidal silica dispersed in an organic solvent, water, or a mixed solvent thereof, to form colloidal silica. It can be obtained by partially hydrolyzing the hydrolyzable organosilane with water therein or water added separately.

R ³ in the hydrolyzable organosilane represented by the general formula (6) is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, such as a methyl group, an ethyl group, a propyl group, Alkyl groups such as butyl group, pentyl group, hexyl group, heptyl group, octyl group; cycloalkyl groups such as cyclopentyl group, cyclohexyl group; aralkyl groups such as 2-phenylethyl group, 3-phenylpropyl group; phenyl group, tolyl Aryl groups such as vinyl groups; alkenyl groups such as vinyl groups and allyl groups; halogen-substituted hydrocarbon groups such as chloromethyl groups, γ-chloropropyl groups, and 3,3,3-trifluoropropyl groups; γ-methacryloxypropyl groups Substituted hydrocarbon such as γ-glycidoxypropyl group, 3,4-epoxycyclohexylethyl group, γ-mercaptopropyl group, etc. It can be exemplified, and the like. Among these, an alkyl group having 1 to 4 carbon atoms and a phenyl group are preferable because of easy synthesis or availability.

  Examples of the hydrolyzable group X in the general formula (6) include an alkoxy group, an acetoxy group, an oxime group, an enoxy group, an amino group, an aminoxy group, and an amide group. Among these, an alkoxy group is preferable because it is easily available and the silica-dispersed oligomer solution (A) can be easily prepared. Examples of such hydrolyzable organosilanes include mono-, di-, tri-, and tetra-functional alkoxysilanes in which the n in the general formula (6) is an integer of 0 to 3, acetoxy Examples thereof include silanes, oxime silanes, enoxysilanes, aminosilanes, aminoxysilanes, and amidosilanes. Among these, alkoxysilanes are preferable because they are easily available and the silica-dispersed oligomer solution (A) can be easily prepared.

  In particular, tetramethoxysilane, tetraethoxysilane, and the like can be exemplified as the n = 0 tetraalkoxysilane, and the methyltrialkoxysilane, methyltriethoxysilane, methyltrimethoxysilane, and the like can be exemplified as the n = 1 organotrialkoxysilane. Examples thereof include isopropoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane and the like. Examples of n = 2 diorganodialkoxysilanes include dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, and methylphenyldimethoxysilane. Further, examples of the triorganoalkoxysilane with n = 3 include trimethylmethoxysilane, trimethylethoxysilane, trimethylisopropoxysilane, and dimethylisobutylmethoxysilane. Organosilane compounds generally called silane coupling agents can also be used as alkoxysilanes.

  Of these hydrolyzable organosilanes of the general formula (6), 50 mol% or more is preferably a trifunctional compound represented by n = 1. More preferably, it is 60 mol% or more, and most preferably 70 mol% or more. When the trifunctional compound with n = 1 is less than 50 mol%, it is difficult to obtain a sufficient coating film hardness, and the dry curability tends to be inferior.

  As the colloidal silica used in the component (A), water-dispersible or non-aqueous organic solvent-dispersible colloidal silica such as alcohol can be used, and the colloid used for the silicone-based coating agent (1) described above. The same silica gel can be used. Generally, such colloidal silica contains 20 to 50% by weight of silica as a solid content, and the amount of silica can be determined from this value.

  When water-dispersible colloidal silica is used, water present as a component other than the solid content can be used for hydrolysis of the component (A). Water-dispersible colloidal silica is usually made from water glass, but such colloidal silica is readily available commercially. The organic solvent-dispersible colloidal silica can be easily prepared by replacing the water of the water-dispersible colloidal silica with an organic solvent. Such an organic solvent-dispersible colloidal silica can be easily obtained as a commercial product in the same manner as the water-dispersible colloidal silica. Examples of the organic solvent in which the colloidal silica is dispersed include, for example, lower aliphatic alcohols such as methanol, ethanol, isopropanol, n-butanol, and isobutanol; ethylene glycol, ethylene glycol monobutyl ether, and ethylene glycol monoethyl ether acetate. Examples include ethylene glycol derivatives; diethylene glycol derivatives such as diethylene glycol and diethylene glycol monobutyl ether, and diacetone alcohol. One or two or more selected from the group consisting of these can be used, but in combination with these hydrophilic organic solvents, toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, Methyl ethyl ketoxime can also be used.

  The colloidal silica in the component (A) is essential for increasing the hardness of the cured film of the silicone coating agent (2). In the component (A), the colloidal silica is preferably contained in the range of 5 to 95% by weight as the silica solid content. More preferably, it is 10 to 90 weight%, Most preferably, it is the range of 20 to 85 weight%. If the content is less than 5% by weight, the desired film hardness cannot be obtained, and if it exceeds 95% by weight, it is difficult to uniformly disperse the silica, which may cause inconveniences such as gelation in the component (A). .

  The silica-dispersed oligomer of organosilane (A) is usually a partial hydrolysis of hydrolyzable organosilane of general formula (6) in at least one of water-dispersible colloidal silica or organic solvent-dispersible colloidal silica. Can be obtained. The amount of water used relative to the hydrolyzable organosilane is preferably 0.001 to 0.5 mol of water with respect to 1 mol of the hydrolyzable group. If the amount of water used is less than 0.001 mol, a sufficient partial hydrolyzate cannot be obtained, and if the amount of water used exceeds 0.5 mol, the stability of the partial hydrolyzate may be deteriorated. There is. The method of partial hydrolysis is not particularly limited, and a hydrolyzable organosilane and colloidal silica may be mixed and mixed with a necessary amount of water. At this time, the partial hydrolysis reaction proceeds at room temperature. In order to promote the partial hydrolysis reaction, it may be heated to 60 to 100 ° C. Furthermore, hydrochloric acid, acetic acid, halogenated silane, chloroacetic acid, citric acid, benzoic acid, dimethylmalonic acid, formic acid, propionic acid, glutaric acid, glycolic acid, maleic acid, malonic acid, toluene for the purpose of promoting partial hydrolysis reaction An inorganic acid such as sulfonic acid or oxalic acid or an organic acid may be used as a catalyst.

  The silica-dispersed oligomer of organosilane as component (A) has a liquid pH value in the range of 2.0 to 7.0, more preferably 2.5 to 6.5, in order to obtain long-term stable performance. It is good to adjust to the range of pH 3.0-6.0 in the range of 3.0-6.0. When the pH value is out of this range, the long-term performance deterioration of the component (A) may be remarkable particularly when the amount of water used is 0.3 mol or more with respect to X1 mol. If the pH value of the component (A) is outside this range, the pH value may be adjusted by adding a basic reagent such as ammonia or ethylenediamine when the pH value is more acidic than this range. What is necessary is just to adjust pH value using acidic reagents, such as hydrochloric acid, nitric acid, and an acetic acid. The adjustment method is not particularly limited.

The (B) component silanol group-containing polyorganosiloxane used in the silicone-based coating agent (2) has an average composition formula represented by the above formula (7), and R ⁴ in the formula (7) is: it can be exemplified the same as ^{R 3} of the above (6) wherein 5 to 50 wt% in ^{R 4} is a phenyl group. If the phenyl group is less than 5% by weight, the elongation of the coating film is reduced and cracks are likely to occur, and if it exceeds 50% by weight, curing may be too slow. The other R ⁴ is preferably an alkyl group having 1 to 4 carbon atoms, a vinyl group, a γ-glycidoxypropyl group, a γ-methacryloxypropyl group, a γ-aminopropyl group, 3,3,3-trifluoropropyl. Substituted hydrocarbon groups such as groups, more preferably alkyl groups of methyl and ethyl groups. In the formula (7), d and e are numbers satisfying the relations 0.2 ≦ d ≦ 2.0, 0.0001 ≦ e ≦ 3, and d + e <4, respectively, and d is less than 0.2 or e is If it exceeds 3, there are disadvantages such as cracks in the cured film, and if d is more than 2 and 4 or less, or if e is less than 0.0001, curing does not proceed well.

  Such a silanol group-containing polyorganosiloxane (B) of the formula (7) is, for example, methyltrichlorosilane, dimethyldichlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, or one or two alkoxysilanes corresponding thereto. The above mixture can be obtained by hydrolyzing with a large amount of water by a known method. In order to obtain a silanol group-containing polyorganosiloxane, when it is hydrolyzed by a known method using alkoxysilane, an unhydrolyzed alkoxy group may remain in a trace amount. That is, a polyorganosiloxane in which a silanol group and a trace amount of an alkoxy group coexist may be obtained, but such a polyorganosiloxane may be used.

  Further, the molecular weight of the silanol group-containing polyorganosiloxane as the component (B) is preferably 700 to 20000. The molecular weight here is a weight average molecular weight in terms of standard polystyrene by GPC (gel permeation chromatography) measurement, and when it is less than 700, the curability of the formed coating film is slow and cracks are likely to occur. When it exceeds 20000, there is a possibility that the coating film formed from the silicone-based coating agent (2) to which the pigment is added has no gloss and the smoothness is also deteriorated.

  The curing catalyst of the component (C) used in the silicone-based coating agent (2) accelerates the condensation reaction between the components (A) and (B) and cures the film. Examples of such catalysts include metal salts of carboxylic acids such as alkyl titanates, tin octylate and dibutyltin dilaurate, dioctyltin dimaleate; amine salts such as dibutylamine-2-hexoate, dimethylamine acetate, and ethanolamine acetate; Carboxylic acid quaternary ammonium salts such as tetramethylammonium acetate; amines such as tetraethylpentamine; N-β-aminoethyl-γ-aminopropyltrimethoxysilane, N-β-aminoethyl-γ-aminopropylmethyl Amine-based silane coupling agents such as dimethoxysilane; acids such as p-toluenesulfonic acid, phthalic acid and hydrochloric acid; aluminum compounds such as aluminum alkoxide and aluminum chelate; alkali catalysts such as potassium hydroxide; tetraisopropyl titanate; There are titanium compounds such as trabutyl titanate and titanium tetraacetylacetonate, and halogenated silanes such as methyltrichlorosilane, dimethyldichlorosilane, and trimethylmonochlorosilane. In addition to these, components (G) and (H) There is no particular limitation as long as it is effective for the condensation reaction.

  The blending ratio of the component (A) and the component (B) is 99 to 1 part by weight of the component (B) with respect to 1 to 99 parts by weight of the component (A), preferably 5 to 95 parts by weight of the component (A). In contrast, 95 to 5 parts by weight of component (H), more preferably 90 to 10 parts by weight of component (H) with respect to 10 to 90 parts by weight of component (A) (provided that component (A) and component (B) Total amount of 100 parts by weight). When the component (A) is less than 1 part by weight, the room temperature curability is inferior and sufficient film hardness cannot be obtained. On the other hand, if the component (A) exceeds 99 parts by weight, the curability is unstable and a good film may not be obtained.

  Moreover, it is preferable that the addition amount of the curing catalyst of (C) component is 0.0001-10 weight part with respect to a total of 100 weight part of (A) component and (B) component. More preferably, it is 0.0005-8 weight part, Most preferably, it is 0.0007-5 weight part. If the addition amount of the curing catalyst (C) is less than 0.0001 parts by weight, it may not be cured at room temperature, and if the addition amount of the curing catalyst (C) exceeds 10 parts by weight, the heat resistance and weather resistance of the coating may be reduced. It may get worse.

  You may add a pigment, a matting agent, a filler, etc. to the silicone type coating agent (1) or (2) prepared as mentioned above. Examples of pigments to be added include organic pigments such as carbon black, quinacridone, naphthol red, cyanine blue, cyanine green, and hansa yellow, titanium oxide, barium sulfate, petal, calcium carbonate, alumina, iron oxide red, and composite metal oxide. An inorganic pigment such as a product is good, and one or two or more selected from these groups can be used in combination. Among these, inorganic pigments are preferable for improving weather resistance. Moreover, silica powder, barium sulfate, etc. can be used as a filler, and it can be used combining 1 type (s) or 2 or more types chosen from the group enumerated above. The particle diameter of the pigment or filler is not particularly limited, but is preferably about 0.01 to 4 μm in average particle diameter.

  The amount of pigment added is not particularly limited because the concealability varies depending on the type of pigment, but in the case of an inorganic pigment, a range of 15 to 80 parts by weight with respect to 100 parts by weight of the resin solid content is preferable. When the amount is less than 15 parts by weight, the concealability cannot be sufficiently obtained, and when it exceeds 80 parts by weight, the smoothness of the coating film may be deteriorated. The pigment can be dispersed by an ordinary method, and a dispersant, a dispersion aid, a thickener, a coupling agent, and the like can be used at that time.

  And an ultraviolet-absorbing coating agent can be obtained by adding an ultraviolet absorber to a silicone type coating agent (1) or (2). Examples of ultraviolet absorbers include organic ultraviolet absorbers such as benzotriazole compounds such as 2 (2′hydroxy-5-methylphenyl) benzotriazole, benzophenone compounds such as 2,4-dihydroxybenzophenone, and particulate zinc oxide. And an inorganic ultraviolet absorber such as fine particle titanium oxide can be used, and an organic ultraviolet absorber and an inorganic ultraviolet absorber can be used in combination.

  The organic ultraviolet absorber can be relatively easily dispersed in the silicone coating agent (1) or (2). The addition amount of the organic ultraviolet absorber is not particularly limited, but is in the range of 0.1 to 30% by weight as the solid content with respect to the solid content of the silicone coating agent (1) or (2). Is preferred. If the addition amount is less than 0.1% by weight, the effect of improving the weather resistance due to UV cut becomes insufficient, and if it exceeds 30% by weight, the color of the organic ultraviolet absorber becomes strong, which is not preferable.

  The addition amount of fine particle zinc oxide and fine particle titanium oxide which are inorganic ultraviolet absorbers is not particularly limited, but is 0.1 to 20 with respect to the solid content of the silicone coating agent (1) or (2). A range of% by weight is preferred. If the added amount is less than 0.1% by weight, the effect of improving the weather resistance due to UV cut becomes insufficient, and if it exceeds 20% by weight, it becomes cloudy white.

  Here, the ultraviolet absorber generally has a function of absorbing ultraviolet light and converting it into heat, and the organic ultraviolet absorber has a lifetime because this function is reduced over a long period of time. On the other hand, the lifetime of the inorganic ultraviolet absorber is semi-permanent, and it is preferable to use an inorganic ultraviolet absorber such as fine particle zinc oxide or fine particle titanium oxide as the ultraviolet absorber. However, fine particle zinc oxide and fine particle titanium oxide have poor dispersibility in the silicone-based coating agent (1) or (2), and agglomerate and the coating film becomes cloudy white. is there. In addition, fine zinc oxide and fine titanium oxide powders have a photocatalytic action. When an acrylic resin or alkyd resin having low weather resistance is used, the resin itself deteriorates and long-term storage stability cannot be obtained. For this reason, it is conceivable to use fine zinc oxide or fine particle titanium oxide dispersed in a solvent. However, fine zinc oxide or fine particle titanium oxide settles quickly in the solvent, and it is difficult to improve the dispersibility by this method.

On the other hand, in the hydrolyzable organosilane represented by the general formula (R ³ ) _n SiX _4-n used in the silica-dispersed oligomer solution of organosilane (A), fine zinc oxide and fine titanium oxide are easily dispersed. This dispersion is excellent in transparency and long-term storage stability. Therefore, it is preferable to use the hydrolyzable organosilane in a state in which fine particle zinc oxide or fine particle titanium oxide is added and dispersed. In addition to directly adding fine particle zinc oxide or fine particle titanium oxide to hydrolyzable organosilane, (R ³ ) _n SiX _4-n hydrolyzable organosilane was prepared by partial hydrolysis in colloidal silica (A ) The silica dispersion oligomer solution of organosilane may be dispersed by adding fine particle zinc oxide or fine particle titanium oxide, and this silica dispersed oligomer solution in which fine particle zinc oxide or fine particle titanium oxide is dispersed is used as a silicone coating agent. By adding to (1) or (2), a coating agent containing fine zinc oxide or fine titanium oxide can be prepared. In this case, the primary particle (non-aggregated particles) of the fine particle zinc oxide or fine particle titanium oxide is preferably 0.01 μm to 0.5 μm, and the silica-dispersed oligomer solution of organosilane of (A) Fine zinc oxide or fine titanium oxide can be dispersed up to about 200 parts by weight with respect to 100 parts by weight (when the amount exceeds 200 parts by weight, the viscosity increases and stirring becomes impossible). The dispersion can be performed using a general mixing apparatus such as a sand mill, a ball mill, or a paint shaker. At this time, an additive aid or filler may be added at a level that does not lower the weather resistance.

  And the ultraviolet absorption layer 14 can be formed by apply | coating said ultraviolet absorber containing silicone type coating agent (1) or (2) to the surface of the transparent substrate 20, and making it harden by drying. The coating agent can be applied by various methods such as brush coating method, dipping method, spray coating method, roll coating method, bell method, flow coating method, curtain coating method, knife coating method, etc., but with a uniform thickness. In order to easily obtain the coating film, it is preferable to apply by a spray coating method, a roll coating method, or a bell method using a rotating cup. By forming the coating film with a uniform thickness in this way, it is possible to obtain a uniform elongation at break of the coating film. The film thickness of the ultraviolet absorbing layer 14 is preferably in the range of 2 to 15 μm. In addition, a photocatalyst-containing silicone coating agent is applied to the surface of the ultraviolet absorbing layer 14 in the same manner as described above, followed by drying and curing, thereby forming the photocatalytic functional layer 13 and obtaining the dye-sensitized solar cell 4. Is.

  By attaching the dye-sensitized solar cell 4 shown in FIG. 3 to the surface of the building board 3 in the same manner as described above, the building board A with solar cells shown in FIG. 4 can be formed. When the ultraviolet absorbing layer 14 is formed by coating the surface of the transparent substrate 20 of the dye-sensitized solar cell 4, the action of the ultraviolet absorbent in the ultraviolet absorbing layer 14 (generally absorbs ultraviolet rays and converts them into heat). Therefore, the ultraviolet absorbing layer 14 can absorb ultraviolet rays so as not to reach the makeup 2 of the base material 1, and thereby the base material 1 and the makeup 2 (coating film 10). (Including the discoloration) can be made difficult to occur.

  The building board A with a solar cell of the present invention can be used not only as an outer wall material but also as a building member such as a roofing material, a flooring material, a curtain, or a rain gutter.

  Hereinafter, the present invention will be described specifically by way of examples.

(Example 1)
As the building board 3, the product name “Cast Stripe” manufactured by Kubota Matsushita Electric Works Co., Ltd. was used. This building board 3 has been conventionally used as an outer wall material, and is formed with a makeup 2 made up of a concavo-convex pattern 5 and a coating film 10 on the surface of a ceramic base material 1 mainly composed of cement. It is.

The dye-sensitized solar cell 4 was prepared as follows. As the transparent substrates 20 and 21 having the transparent electrodes 22 and 23, conductive glass plates (FTO glass made by Nippon Sheet Glass, 10Ω, size 100 × 100 mm) were used. As the titanium oxide paste, Soralonix SA Ti-Nanoxide T (manufactured by Solaronics) was used. As the dye solution, an acetonitrile / t-butanol 50/50 vol% solution of ruthenium complex [RuL ₂ (NCS) ₂ , L = 4,4′-dicarboxy-2,2′bipyridine] was used. As the electrolyte solution for forming the electrolyte layer 24, the solutes are LiI (0.1M), I ₂ (0.05M), 4-tertiary-butylpyridine (0.5M), and DMPII (0.6M) (in parentheses). Is the number of moles), and the solvent is 3-methoxypropiononitrile. First, a titanium oxide paste is applied to the surface of the conductive glass plate by a screen printing method or a squeegee method (thickness of titanium oxide is 5 to 10 μm). Next, the conductive glass plate coated with the titanium oxide paste is baked in an electric furnace at 500 ° C. for 1.5 hours. Next, the fired conductive glass plate is cooled to room temperature. Next, the cooled conductive glass plate was immersed in a ruthenium dye solution for 24 hours, and the dye (ruthenium complex) 25 was adsorbed on the titanium oxide film (particle film 26) of the conductive glass plate (referred to as glass plate 1). ). Next, platinum was vapor-deposited on the surface of another conductive glass plate different from the above, and a hole for injecting an electrolyte solution was previously formed thereon, and this was prepared as a counter electrode (referred to as glass plate 2). Next, the glass plate 1 and the glass plate 2 were bonded together, and after the bonding, an electrolyte solution was injected from the hole, and then the hole was sealed with an adhesive. Thereafter, the photocatalyst-containing silicone-based coating agent is applied to the surface of the transparent substrate 20 (the outer surface on which the transparent electrode 23 and the particle film 26 are not formed) by a spray method, and baked at 150 ° C. for 1 minute. A photocatalytic functional layer 13 having a thickness of 0.5 μm was formed. The photocatalyst-containing silicone coating agent was prepared as follows. First, 10 parts by weight of tetraethoxysilane, 90 parts by weight of IPA organosilica sol, 30 parts by weight of dimethyldimethoxysilane, and 100 parts by weight of isopropyl alcohol (IPA) are mixed with 100 parts by weight of methyltrimethoxysilane, and then 90 parts by weight of water. Was added and stirred. After preparing a weight average molecular weight Mw of 1500 in a constant temperature bath at 60 ° C., 20 parts by weight of titanium oxide was added to the prepared liquid and stirred to obtain a photocatalyst-containing silicone coating agent. . Thereby, the dye-sensitized solar cell 4 as shown in FIG. 1 was formed. The light transmittance of this dye-sensitized solar cell 4 was 60%.

  The surface of the transparent substrate 21 of the dye-sensitized solar cell 4 (the outer surface of the transparent substrate 21 on which the photocatalytic function layer 13 is not formed) is adhered to the surface of the coating film 10 of the building board 3 with an adhesive. The building board A with a solar cell of the present invention was formed by bonding.

(Example 2)
A building board A with solar cells was formed in the same manner as in Example 1 except that the ultraviolet absorbing layer 14 was formed between the transparent substrate 20 and the photocatalytic functional layer 13. A silicone-based coating agent containing an ultraviolet absorber was prepared as follows. First, 100 parts by weight of methyltrimethoxysilane, 20 parts by weight of tetraethoxysilane, 150 parts by weight of isopropyl alcohol organosilica sol (“OSCAL1432” manufactured by Catalyst Chemical Industry Co., Ltd., SiO ₂ content 30% by weight), 40 parts by weight of dimethyldimethoxysilane And 100 parts by weight of isopropyl alcohol were mixed, 200 parts by weight of water was further added and stirred, and a silicon alkoxide was prepared by adjusting the weight average molecular weight Mw to 1200 in a thermostatic bath at 60 ° C. Next, a silicone-based coating agent was obtained by blending the silicon alkoxide with 13% by weight of zinc oxide as an ultraviolet absorber with respect to the total amount of solids and 4% by weight of colloidal silica as a matting agent with respect to the total amount of solids. A silicone-based coating agent containing this ultraviolet absorber and matting agent is applied to the surface of the transparent substrate 20 (the outer surface on which the transparent electrode 23 and the particle film 26 are not formed) with a bar coater, and the baking energy is 5000 ° C. The ultraviolet absorbing layer 14 of an inorganic coating film having a film thickness of 4 μm was formed by baking under the conditions of sec. Thereafter, the photocatalyst functional layer 13 was formed by applying and curing a photocatalyst-containing silicone coating agent on the surface of the ultraviolet absorbing layer 14 in the same manner as described above. The light transmittance of this dye-sensitized solar cell 4 was 60%.

  In the same manner as in Example 1, the surface of the transparent substrate 21 of the dye-sensitized solar cell 4 on the surface of the coating film 10 of the building board 3 (the transparent substrate 21 on which the photocatalytic function layer 13 is not formed). The building board A with a solar cell of the present invention was formed by adhering the outer surface of the solar cell with an adhesive.

(Comparative Example 1)
A building board with a solar cell was formed in the same manner as in Example 1 except that the dye-sensitized solar cell 4 in which the photocatalytic function layer 13 was not formed was used.

In Examples 1 and 2 and Comparative Example 1 described above, the design of the appearance when the makeup 2 of the building board 3 was seen through the dye-sensitized solar cell was evaluated. The criteria for the evaluation of the design were evaluated as ○ when the pattern and color of the makeup 2 of the building board 3 were clearly visible, and × when the pattern and color of the makeup 2 of the building board 3 were not clearly visible. In Examples 1 and 2 and Comparative Example 1, the power generation amount (W) when the dye-sensitized solar cell 4 was irradiated with light having an irradiation light amount of 100 mW / cm ² was measured. In Examples 1 and 2 and Comparative Example 1, a stain resistance test was performed. In this test, 5% carbon liquid was applied to the surface of the photocatalytic functional layer 13 of the dye-sensitized solar cell of the building board with solar cell, and the color before and after the application was measured with a color measuring device CR-400 (manufactured by Konica Minolta). It was measured. Then, the case where the color difference ΔE before and after the application of the 5% carbon liquid was 3 or less and the stain was small was evaluated as ◯, and the case where the color difference ΔE before and after the application of the 5% carbon solution was larger than 3 and the stain was large was evaluated as x. In Examples 1 and 2 and Comparative Example 1, the visible light transmittance of the dye-sensitized solar cell 4 after the stain resistance test was measured with an ultraviolet-visible spectrophotometer (UV-VIS measurement). A case where the decrease in visible light transmittance before and after the application of the 5% carbon liquid is 20% or less and a case where the decrease in visible light transmittance before and after the application of the 5% carbon liquid is greater than 20% It was evaluated. For comparison, in Example 1, the dye-sensitized solar cell 4 was not used (that is, only the building board 3) and the building board 3 was not used (that is, only the dye-sensitized solar cell 4). And Comparative Examples 2 and 3 were evaluated together. The results are shown in Table 1.

It is sectional drawing which shows an example of embodiment of the dye-sensitized solar cell of this invention. It is sectional drawing which shows an example of embodiment of the building board with a solar cell of this invention. It is sectional drawing which shows an example of other embodiment of the dye-sensitized solar cell of this invention. It is sectional drawing which shows an example of other embodiment of the building board with a solar cell of this invention.

Explanation of symbols

A Building board with solar cell 3 Building board 4 Dye-sensitized solar cell 13 Photocatalytic functional layer 14 Ultraviolet absorbing layer 20 Transparent substrate 21 Transparent substrate 22 Transparent electrode 23 Transparent electrode 24 Electrolyte layer 26 Particle film

Claims (5)

  In a dye-sensitized solar cell formed with a transparent electrode, an electrolyte layer, and a particle film between a pair of opposed transparent substrates, a photocatalytic function layer is provided on the surface of at least one transparent substrate. A dye-sensitized solar cell characterized by the above.   A building board with a solar cell, wherein the dye-sensitized solar cell according to claim 1 is provided on the surface side of the building board so that the photocatalytic functional layer is located outward.   The building board with solar cells according to claim 2, wherein the photocatalytic functional layer is an inorganic coating film.   The building board with solar cell according to claim 2 or 3, wherein an inorganic ultraviolet absorbing layer is provided between the transparent substrate and the photocatalytic functional layer. 5. The building board with solar cells according to claim 2, wherein the dye-sensitized solar cell has transparency and is decorated on the surface of the building board. 6.

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