JP4816864B2 - Dye-sensitized solar cell - Google Patents

Description

  The present invention relates to a dye-sensitized solar cell, and particularly to the structure of a sealing material layer of a dye-sensitized solar cell excellent in resistance to an electrolytic solution.

  The dye-sensitized solar cell announced by Gretzell et al. In 1991 operates by a mechanism different from that of a silicon semiconductor pn junction solar cell, and has an advantage of high conversion efficiency and low manufacturing cost. This solar cell is also called a wet solar cell because an electrolyte is sealed inside.

  The structure will be briefly described below. First, a transparent conductive film is formed on one surface of a single transparent substrate, and titanium oxide particles adsorbed with a photosensitizer such as a dye are formed as a main component. A porous membrane is provided. On the other hand, a transparent conductive film is formed on another transparent substrate, and a conductive substrate having a platinum catalyst layer formed thereon is formed. Next, both substrates are made to face each other via a sealant, and an electrolyte is injected into a gap formed by both the substrates and the sealant to manufacture a dye-sensitized solar cell.

  The mechanism by which this solar cell generates electricity is as follows. When light strikes the transparent substrate, the dye absorbs the light and emits electrons. Electrons move to the titanium oxide film and are transmitted to the electrode. Further, the electrons move to the counter electrode and reduce ions in the electrolyte. The reduced ions are oxidized again on the dye. This is repeated to generate electricity.

  The electrolyte present in the battery is an indispensable component for the dye-sensitized solar cell to generate power, and usually an iodine solution dissolved in a highly polar organic solvent is used. Therefore, it is thought that this leakage of electrolyte is largely attributable to the deterioration in battery performance. Therefore, the prevention of electrolyte leakage is an important technology for obtaining the reliability of dye-sensitized solar cells. is there.

  There have been several examples of inventions related to a sealant for a dye-sensitized solar cell. In JP-A-2004-6328, JP-A-2003-168493, JP-A-2003-168494, and JP-A-2003-188394, a sheet-like sealant using an ionomer is used at the time of battery preparation. Yes. Japanese Unexamined Patent Publication No. 2000-173680 discloses a technique in which a light receiving electrode and a counter electrode are combined so as to overlap each other, and a sealing solid material coated with a sealing resin is interposed between the electrodes. Further, an invention using a liquid resin as a sealant for a dye-sensitized solar cell is also known. For example, according to Japanese Patent Application Laid-Open Nos. 2000-173680 and 2002-368236, a light receiving electrode and a counter electrode In addition, epoxy resin and silicone resin are used as a sealing material between electrodes, and reactive polyisobutylene is used in JP 2002-313443 A, and glass in JP 2003-223939 A is used. Epoxy resins, urethane acrylate resins, and epoxy acrylate resins are used as hard resins having a transition point of 80 ° C. or higher.

  In recent years, not only a technique for sealing an electrolytic solution but also an electrolytic solution with less leakage has been actively developed. For example, there is a technique for improving cell reliability by a technique of dispersing and impregnating an electrolytic solution in a polymer gel. For example, in JP 2002-289268 A, JP 2002-299665 A, JP 2004-87202 A, and JP 2003-132964 A, leakage of an electrolyte is caused by enclosing the electrolyte in a polymer gel. A technique for preventing this has been devised.

  Further, according to the published patent publication related to Japanese Patent Laid-Open No. 2000-173680, the photoelectrode and the counter electrode are combined so as to overlap each other, and a sealing resin is applied between the photoelectrode and the counter electrode. A technique for interposing a solid material is disclosed. However, in such a technique, the solid sealant is standardized with a specific width, and the seal has a great feature. From this viewpoint, a seal area larger than a certain width is required, and the liquid sealant is liquid. Considering double sealing with resin, it is considered that the sealing ability is low as a sealing agent.

  On the other hand, the following Patent Documents 1 to 7 show examples in which a polyethylene spacer having a thickness of 8 μm to 20 μm is used and the outer peripheral portion is sealed with an epoxy resin adhesive. Patent Documents 8 to 11 use a 20 μm-thick polyfluorinated ethylene sheet, Patent Document 12 uses a width of about 3 mm and a 20 μm-thick polyfluorinated ethylene sheet as a spacer, and the outer periphery is bonded with epoxy resin. An embodiment sealed with an agent is shown. Patent Documents 13 to 14 show examples in which fine fluoroethylene particles having a thickness of 10 μm are used as spacers and the outer periphery is sealed with an epoxy resin adhesive. Patent Document 15 uses silica having a diameter of 10.3 μm, Patent Document 16 includes an ionomer sheet having a thickness of 25 μm, Patent Document 17 includes a spacer of about 100 μm to 3 mm, and Patent Document 18 includes glass having a diameter of 50 μm. An example in which the outer peripheral portion is sealed with an epoxy resin adhesive is shown as a spacer.

  However, the spacers of Patent Documents 1 to 18 are for securing the distance between the electrodes, and unlike the thickness of the sealing material, there are no examples regarding the thickness and width of the sealing material layer. Moreover, the content which suggests that the thickness and width | variety of a sealing material layer are important in order to prevent the electrolyte solution leak which is the objective of this invention is not contained. Patent Documents 19 to 22 show examples in which a thermoplastic resin such as high-milan is used as a sealing material, but there is no description about the thickness of the sealing material after thermocompression bonding. There is no description. Patent Document 23 shows an example in which an epoxy resin containing polystyrene particles having a diameter of 10 μm is used to form a sealing material layer having a thickness of 10 μm, but there is no description regarding the width of the sealing material. Moreover, the content which suggests that the thickness and width | variety of a sealing material layer are important in order to prevent the electrolyte solution leak which is the objective of this invention is not contained. Patent Documents 24 to 25 show examples in which a sealing material layer having a thickness of 10 μm and a width of 5 mm is formed.

  However, there is no description about the necessity and reason for the size of the sealing material layer, and the thickness and width of the sealing material layer are important in order to prevent the leakage of the electrolyte as the object of the present invention. The content which suggests is not included. Patent Document 26 discloses a technique relating to an epoxy-based sealant containing a filler having a particle size of 10 μm or less. When this sealing agent is used, a sealing material layer substantially corresponding to the particle size of the filler, that is, a sealing material layer having a thickness of 10 μm or less is formed. The reason for this is that the filler exceeds 10 μm. It is mentioned that gap formation is not successful when using. However, in this patent document, since the sealing material does not mainly have the original function of preventing the leakage of the electrolyte solution, there is no description about the width of the sealing material, and the thickness or width of the sealing material layer does not cause the leakage of the electrolyte solution. It does not contain content that suggests that it is important as a preventive factor.

Patent Document 27 discloses the use of a sealing material having a high glass transition temperature in order to prevent leakage of the electrolytic solution. However, in the experiments conducted by the present inventors, the thickness and width of the sealing material layer are important to prevent leakage of the electrolyte, and rather the result is that the heat cycleability is poor when the glass transition temperature is high. It has been. Japanese Patent Application Laid-Open No. 2004-228561 discloses a technique that enables a substrate interval to be maintained at a predetermined interval even when the cell size is increased. In this patented technology, it is essential that the sealing material layer interposes a spacer made of a nonwoven fabric or a woven fabric, and the sealing material does not have the primary function of preventing the electrolyte solution from leaking. The contents suggesting that the thickness and width of the material layer are important as a factor for preventing electrolyte leakage are not included. Patent Document 29 discloses a technique for substantially forming a sealing material layer with a thickness of 1 μm to 200 μm. In this patented technology, the thickness of the sealing material layer is to allow the electrolyte to be injected using centrifugal force, and the sealing material is mainly intended for the original function of preventing the electrolyte from leaking. Therefore, there is no description regarding the width of the sealing material, and there is no content that suggests that the thickness or width of the sealing material layer is important as a factor for preventing electrolyte leakage.
JP 2000-285877 A JP 2001-35549 A JP 2001-93588 A JP 2001-143771 A JP 2001-185242 A JP 2001-229984 A JP 2001-243955 A JP 2000-285980 A JP 2000-294304 A JP 2000-294814 A JP 2000-323189 A JP 2000-357544 A JP 2000-323192 A JP 2001-307785 A JP 2000-299138 A JP 2002-75474 A JP 2002-216861 A JP 2003-151355 A JP 2002-343454 A JP 2003-297446 A JP 2003-303630 A JP 2003-342488 A JP 2002-298936 A JP 2002-184477 A Japanese Patent Laid-Open No. 2003-100300 JP 2002-368233 A JP 2003-223939 A JP 2003-331935 A JP 2004-327167 A JP 2004-6328 A JP 2003-168493 A JP 2003-168494 A JP 2003-188394 A JP 2000-173680 A JP 2002-368236 A JP 2002-313443 A Japanese Patent Laid-Open No. 2003-223939 JP 2002-289268 A JP 2002-299665 A JP 2004-87202 A JP 2003-132964 A JP 2000-173680 A

  The technology for sealing an electrolyte solution in a dye-sensitized solar cell is an important technology in terms of cell configuration, and it is thought that the establishment of this technology will greatly contribute to the improvement of cell life and reliability. On the other hand, fluid leakage is generally classified into interfacial leakage that occurs between the sealing material layer and the sealing substrate and osmotic leakage that penetrates the inside of the sealing material layer. Among these, in order to prevent osmotic leakage, the contact area between the sealing medium and the sealing material is reduced (the thickness of the sealing material is reduced), and the path through which the sealing medium permeates is increased (the width of the sealing material is increased). It is well known that this is effective. However, in the conventional dye-sensitized solar cells, there is almost no detailed description regarding the structure of the sealing material (sealing material) for sealing the electrolyte, and in particular, a cured product of a liquid reactive resin as the sealing material. There was no detailed explanation about the seal width and seal thickness when using. Therefore, the present invention prevents special electrolyte leakage from the dye-sensitized solar cell, and more specifically, the width and thickness of the sealing material layer for preventing electrolyte leakage, physical properties, electrolyte resistance characteristics, etc. It is an object of the present invention to provide a dye-sensitized solar cell with no electrolyte leakage by controlling the above.

  In order to ensure long-term reliability of the dye-sensitized solar cell, the present inventors have conducted various studies on a method for preventing electrolyte leakage in a sealed cell, and as a result, have a specific sealing material width. As described above, the present inventors have found a phenomenon in which the leakage of the electrolyte solution suddenly decreases below a certain thickness of the sealing material and has led to the present invention. That is, in claim 1 of the present invention, the electrode part (A), the electrode part (B), and the electrolyte solution (C) in which the porous metal oxide semiconductor film adsorbing the photosensitizer is laminated A dye-sensitized solar cell encapsulated between plates via a sealing material layer, wherein at least one of the two plates has light transmittance, and the sealing material layer has a width of 2 mm or more and a thickness of 1 By forming the film at ˜40 μm or less, the above-mentioned problems have been solved.

  Hereinafter, the present invention will be described in more detail. First, the structure of the dye-sensitized solar cell in the present invention is as follows. FIG. 1 shows a dye-sensitized solar cell commonly called a Gretzel cell. A porous metal oxide semiconductor film 4 (titanium oxide particles made porous with a transparent substrate 2a adsorbed with a transparent electrode 6a and a photosensitizer (dye)). And a laminated substrate 1b in which an electrode 6b and a platinum catalyst 3 are sequentially laminated on a substrate 2b are sealed with a sealing material 5 with a laminated surface inside, and laminated. An electrolytic solution 7 is sealed in a space formed by the substrates 1a and 1b and the sealing material 5. In FIG. 2, a member obtained by laminating the electrode 6 and the porous metal oxide semiconductor film 4 and a member obtained by laminating the electrode 6 and the platinum catalyst 3 are alternately laminated on one substrate 1b to obtain a laminated surface. The inside and the other transparent substrate 1a are sealed with a sealing material 5. Moreover, the electrolyte solution 7 is enclosed in the space produced by this.

  The sealing electrolyte in the present invention is a component that acts as a charge transfer medium in a dye-sensitized solar cell, and is an indispensable component for a photoelectric conversion effect. The general photoelectric conversion action is described in Gletzel et al. Am. Chem. Soc. 115, 6382 (1993), the components are composed of a highly polar organic solvent and a redox agent. As known knowledge, any organic solvent-based electrolyte component can be used. However, in terms of obtaining a photoelectric conversion action as a regenerative electrolyte in the oxidation-reduction process, it is easy to impregnate the titanium oxide semiconductor part, It is desirable to have actions such as being less likely to deteriorate during the conversion process, and preventing side reactions from occurring in the electrolyte component due to light and heat action. Among the components that satisfy these conditions, a preferable combination is the above-described electrolytic solution component. As the highly polar organic solvent, those known as reaction media in electrochemical reactions are desirable, and in particular, those having a high dielectric constant and capable of dissolving salts as used in lithium ion batteries are preferred. Examples of such solvents include cyclic carbonates such as ethylene carbonate, propylene carbonate, butylene carbonate, acyclic carbonates such as dimethyl carbonate, diethyl carbonate, and methyl ethyl carbonate, dioxane, tetrahydrofuran, 2-methyltetrahydrofuran, and ethylene glycol dialkyl ether. , Ethers such as propylene glycol dialkyl ether, polyethylene glycol monoalkyl ether, polyethylene glycol dialkyl ether, nitriles such as acetonitrile, glutarodinitrile, methoxyacetonitrile, propionitrile, benzonitrile, sulfoxides such as dimethyl sulfoxide and sulfolane , Γ-butyrolactone propylene carbonate, ethylene glycol Non-alkyl ethers, aprotic positive solvents such as dimethyl sulfoxide, lactones such as γ-butyrolactone, amides such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and complex such as 3-methyl-2-oxazolinone Rings and the like can be used. These organic solvents can be arbitrarily selected according to the viscosity of the electrolytic solution and the performance of the battery to be used, and can be mixed as necessary.

As the redox agent component, iodine and a metal iodine compound are preferable. Examples of the metal iodine compound include lithium iodide, sodium iodide, potassium iodide, cesium iodide and the like. Examples of the redox agent combined with iodine include not only the above metal iodine compounds but also iodide salts of quaternary pyridinium salts and quaternary imidazolium salts. Furthermore, hetero compounds such as amines and thiols can also be used as reducing aids, and redox catalysts such as ferrocyanate, ferricyanate, ferrocene, and ferrocyanium ion salts can be added. As a combination of these redox agents and redox assistants, iodine and iodide salt systems are particularly preferable, and the concentration with respect to the electrolytic solution is 0.01 to 2 mol / L, particularly 0.01 to 0.05 mol / L. A range of L is preferred. The photoelectric conversion efficiency greatly depends on the concentration of these redox components added as an electrolyte.

  Since the dye-sensitized solar cell using any of the structures described above has a structure in which the power generation element is enclosed between the two plates, it is sealed with a sealing material 5 so that a liquid material such as an electrolyte does not leak. It is necessary to stop. The sealing material 5 is formed by applying a liquid sealing agent at room temperature on at least one plate in a bead shape by a dispenser or the like, and curing or solidifying by heating or other means. The sealing material 5 may be cured at the same time when the two blades (substrates) are bonded together, or may be previously formed on one or both plates (substrates) with an arbitrary thickness and size. In order to reduce the thickness of the sealing material as much as possible, it is preferable to form the sealing material layer by reacting and curing the sealing agent after the sealing agent is bonded and pressed in a liquid state to obtain a desired thickness. At this time, the thickness of the sealing material 5 can also be controlled by mixing a spacer material (filler with an adjusted particle size) into the sealing material. The width | variety with respect to the longitudinal direction of the sealing material 5 of the sealing agent 5 at this time should just be 2 mm or more, and is determined according to the magnitude | size of the dye-sensitized solar cell to manufacture. When the width of the sealing material is less than 2 mm, the electrolytic solution resistance decreases. The thickness of the sealing material is preferably in the range of 1 to 40 μm. When the thickness is less than 1 μm, a portion where the seal layer does not intervene is generated, so that electrolyte leakage may occur. When the thickness exceeds 40 μm, leakage of the electrolyte tends to occur.

A dye-sensitized solar cell is manufactured by injecting an electrolyte solution between two plates enclosing the power generation element manufactured as described above and sealing the sealing hole with a sealant or the like. Encapsulation of the electrolytic solution includes a method in which a part of the sealing material 5 is provided with a notch and the electrolytic solution is injected from here, or two holes are formed in a part of the plate and the electrolytic solution is injected from here. There is no particular limitation. The size (surface area) of the dye-sensitized solar cell thus obtained is about 1 to 500 cm ² , and a plurality of cells are connected to create a desired voltage.

  Next, the sealing agent which forms the sealing material 5 of the dye-sensitized solar cell of this invention is demonstrated. The sealing agent used in the present invention needs to be a liquid sealing agent at room temperature (about 25 ° C. in the working environment). For that purpose, acrylic resin, urethane resin, silicone resin, modified silicone resin, epoxy resin, polyether Resin, polyester resin, natural rubber, synthetic rubber, and mixtures of these are dissolved in a solvent, or a resin composition that is liquid at room temperature by introducing reactive groups into these resins or rubber to give reaction curability. Can be used. Among these, it is particularly effective to use a saturated hydrocarbon resin as a main component. Specific examples include low-density polyethylene, polybutene, polypropylene, and the like. Among these, a reactive crosslinked polymer is desirable, and more preferred is a reactive sealant mainly composed of an isobutylene resin. Or it is a reactive sealing agent which has a polybutadiene resin as a main component.

  Specific examples of the reactive sealant mainly composed of the above-mentioned isobutylene resin include, for example, an isobutylene polymer containing at least one hydrosilylation-reactive alkenyl group in the molecule in the presence of a platinum catalyst. A reaction system that forms a crosslinked product with an organohydrogenpolysiloxane by reaction is a particularly suitable sealing agent in the present invention. In this sealant, the isobutylene polymer (A) component containing at least one hydrosilylation-reactive alkenyl group in the molecule is polyisobutylene having at least one hydrosilylation-reactive alkenyl group in the molecule. is there. Here, the polyisobutylene is one in which at least 50 mol%, preferably 80 mol% of repeating units are isobutylene units. The average molecular weight is preferably 100-20000. Examples of monomer unit components other than isobutylene include olefins having 4 to 12 carbon atoms, vinyl ethers, aromatic vinyl compounds, vinyl silanes, and allyl silanes. Specific examples of such copolymer components include 1-butene, 2-butene, 2-methyl-1-butene, 3-methyl-1-butene, pentene, 4-methyl-1-pentene, hexene, and vinylcyclohexane. Methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, styrene, α-methyl styrene, dimethyl styrene, pt-butoxy styrene, p-hexenyloxy styrene, p-allyloxy styrene, p-hydroxy styrene, β-pinene, indene, Vinyldimethylmethoxysilane, vinyltrimethoxysilane, divinyldimethoxysilane, vinyltrimethoxysilane, divinyldimethylsilane, 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, trivinylmethylsilane, tetravinylsilane, Allyldi It can be copolymerized with methylmethoxysilane, diallyldimethoxysilane, diallyldimethylsilane, γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropylmethyldimethoxysilane, and the like.

  The alkenyl group capable of hydrosilylation reaction is not limited as long as it is a group containing a carbon-carbon double bond that is active for hydrosilylation reaction. Alkenyl groups include vinyl, allyl, methylvinyl, propynyl, butenyl, pentenyl, hexenyl and other aliphatic unsaturated hydrocarbon groups, cyclopropynyl, cyclobutenyl, cyclopentenyl, cyclohexenyl. And cyclic unsaturated hydrocarbon groups such as In the present invention, the component (A) preferably has two or more alkenyl groups in one molecule. Furthermore, in the component (A) in the present invention, it is desirable that the alkenyl group capable of hydrosilylation is introduced at the polymer terminal. Thus, when the alkenyl group is at the end of the polymer, the effective network chain amount of the finally formed cured product increases, and it becomes easy to obtain a rubber-like cured product having high strength and high elongation. preferable.

  Further, as the isobutylene polymer (A), a compound represented by the following formula can be particularly preferably used.

n represents an integer of 10 to 300, and Ph represents a phenyl group.

  Examples of the curing agent that is the component (B) of the present invention include organohydrogenpolysiloxane. The organohydrogenpolysiloxane here refers to a polysiloxane having a hydrocarbon group or a hydrogen atom on the Si atom, and its structure is specifically shown by the following formula.

[M is an integer of 2-30, n is an integer of 0-30, R1 and R2 are alkyl groups (showing about C1 to C20) and phenyl groups (including derivatives thereof)]

  Further, the number of hydrosilyl groups contained in these components (B) may be at least two in one molecule, but is preferably 2 to 40. When the composition of the present invention is cured by a hydrosilylation reaction, if the number of hydrosilyl groups is more than 40, the stability of the curing agent as the component (B) is deteriorated, and a large amount of hydrosilyl group after curing. The group remains in the cured product and causes voids and cracks.

There is no restriction | limiting in particular about the hydrosilylation catalyst which is (C) component of this invention, Arbitrary things can be used. Specifically, a solid platinum supported on a carrier such as chloroplatinic acid, platinum alone, alumina, silica, carbon black; platinum-vinylsiloxane complex {eg, Ptn (ViMe ₂ SiOSiMe ₂ Vi) n , Pt [(MeViSiO) ₄ ] m}; platinum-phosphine complexes {eg Pt (PPh ₃ ) ₄ , Pt (PBu ₃ ) ₄ }; platinum-phosphite complexes {eg Pt [P (OPh) ₃ ] ₄ , Pt [P (OBu) ₃ ] ₄ } (wherein Me represents a methyl group, Bu represents a butyl group, a Vi vinyl group, Ph represents a phenyl group, and n and m represent integers).

Examples of catalysts other than platinum compounds include RhCl (PPh ₃ ) ₃ , RhCl ₃ , Rh / Al ₂ O ₃ , RuCl ₃ , IrCl ₃ , FeCl ₃ , AlCl ₃ , PdCl ₂ .2H ₂ O, NiCl _2. , TiCl _{4 and the} like. These catalysts may be used alone or in combination of two or more. From the viewpoint of catalytic activity, chloroplatinic acid, platinum-olefin complexes, platinum-vinylsiloxane complexes and the like are preferable. The amount of the catalyst is particularly limited, and it is preferably used in the range of 10 ⁻¹ to 10 ⁻⁸ mol relative to ¹ mol of the alkenyl group in the component (A). It is preferable to use in the range of 10 ⁻² to 10 ⁻⁶ mol. In addition, the hydrosilyl group-forming catalyst is generally expensive, and hydrogen gas is generated and the cured product may foam. Therefore, it is better not to use 10 ⁻¹ mol or more.

  In the present invention, the curable composition is cured by the addition reaction of the Si—H group to the alkenyl group using a noble metal catalyst, so that the curing rate is very fast, which is very convenient for line production.

  Components such as a silane coupling agent, a plasticizer, and an inorganic filler can be added to the reactive sealant mainly composed of an isobutylene resin that can be used in the present invention, if necessary. As the silane coupling agent, a silane coupling agent having at least one functional group selected from an epoxy group, a methacryl group, an acrylic group, a vinyl group, and a carbamate group in the molecule and a silicon atom-bonded alcohol group is desirable. About the said functional group, it is preferable that there exist an epoxy group, a methacryl group, and an acryl group in a molecule | numerator from the point of sclerosis | hardenability and adhesiveness especially. Specifically, as an organosilicon compound having an epoxy functional group and a silicon atom-bonded alkoxy group, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ) Ethyltrimethoxysilane,-(3,4-epoxycyclohexyl) ethyltriethoxysilane. Examples of the organosilicon compound having a methacryl group or an acryl group and a silicon atom-bonded alkoxy group include 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, and 3-acrylonitrile. Examples include roxypropyltriethoxysilane, methacryloxymethyltrimethoxysilane, methacryloxymethyltriethoxysilane, acryloxymethyltrimethoxysilane, and acryloxymethyltriethoxysilane.

  Furthermore, a plasticizer can be added to the reactive sealant mainly composed of an isobutylene resin that can be used in the present invention for the purpose of imparting fluidity. Generally used plasticizers can be used as the plasticizer, but those having good compatibility with the saturated hydrocarbon polymer used in the present invention are preferred. Specific examples of the plasticizer include hydrocarbon-based compounds such as polybutene, hydrogenated polybutene, α-methylstyrene oligomer, liquid polybutadiene, hydrogenated liquid polybutadiene, paraffin oil, naphthene oil, and atactic polypropylene.

  As the inorganic filler, various inorganic fillers such as calcium carbonate, talc, silica, carbon black can be used. However, since the curable composition of the present invention utilizes curing by a hydrosilylation reaction, for example, when the composition contains a large amount of water, a side reaction may occur during the curing reaction. The presence or absence of inhibition on the chemical reaction must be considered. Furthermore, other fillers, antioxidants, ultraviolet absorbers, pigments, surfactants and the like can be appropriately added to the cured composition of the present invention as necessary.

  In addition to the above-described reactive sealant having an isobutylene resin as a main component, a preferable sealant for the present invention includes a reactive sealant having a polybutadiene resin as a main component. Specifically, a polymer component (X) which is a polybutadiene having a (meth) acryl group at the terminal and having a hydrogenated (hydrogenated) main skeleton, a saturated aliphatic elastomer component (Y), and a carbon number of 5 A mixed system of the above chain aliphatic or alicyclic monofunctional (meth) acrylate component (Z) is promising.

  The polymer (X) component having a polybutadiene skeleton having a (meth) acryl group at the terminal and hydrogenated main skeleton is represented by the following formula.

(In the general formula (1), R ¹ and R ² are each independently a hydrogen atom or a methyl group, R ³ and R ⁴ are each independently a simple linking group, an oxygen atom or a C 1-16 substitution, An unsubstituted divalent organic group, where x: y = 0 to 100: 100 to 0 and n is 15 to 150.

  The saturated aliphatic elastomer (Y) component that can be mixed with the above-described sealant is used for the purpose of improving the flexibility, moisture permeability, and solvent resistance of the composition of the present invention. This component (Y) can be used as long as it is compatible with the component (X) and does not cause a problem in the curability of the composition, the physical properties of the cured product, etc., and exhibits rubber elasticity at room temperature. Particularly preferred elastomers include polybutadiene and polyisobutylene, and the addition amount is preferably 20 to 80 parts by weight with respect to component (X). When the amount is less than 20 parts by weight, it is difficult to obtain sufficient solvent resistance. When the amount exceeds 80 parts by weight, the component (X) and the component (Y) are separated after curing and the moisture permeability is significantly reduced.

  The chain aliphatic and alicyclic monofunctional (meth) acrylate monomer (Z) component in the above-mentioned sealant composition preferably has 5 to 20 linear carbon atoms in the aliphatic chain portion, and 8 to 16 Are more preferred. In addition, the monofunctional (meth) acrylate used in the present invention is not suitable for a structure having a polarity such as a hydroxyl group or an amino group, and if a (meth) acrylate having a polar group is added, it is compatible with the component (Y) of the present invention. Not only significantly decreases, but even if compatibility is obtained, the solvent resistance decreases. Specific examples of the chain aliphatic monofunctional (meth) acrylate monomer include 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, and decyl (meth) acrylate. , Dodecyl (meth) acrylate, stearyl (meth) acrylate, hexadecyl (meth) acrylate and the like. Specific examples of the alicyclic (meth) acrylate component used in the present invention include cyclohexyl (meth) acrylate, norbornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and isobornyl. (Meth) acrylate etc. are mentioned. The addition amount is preferably 80 parts by weight or less with respect to the component (A). If it exceeds 80 parts by weight, the flexibility of the cured product will be significantly impaired.

  The sealing agent described in claims 5 and 6 can be cured by heat and light. In the case of thermosetting, it is cured at an appropriate temperature by adding azo compounds or peroxides. Moreover, in photocuring, it hardens | cures under ultraviolet irradiation by addition of benzophenone, cyclohexyl ketone, and acetophenone. Furthermore, redox-type curing with peroxide and metal ions is also possible.

  Also in the sealing agent described in the above-mentioned claims 5 and 6, other additives may be blended in an appropriate amount within a range not impairing the sealing property and coating property of the present invention. Examples of other additives include sensitizers, colorants such as pigments and dyes, polymerization inhibitors, facial agents, antifoaming agents, coupling agents, organic and inorganic fillers, and the like.

  In the dye-sensitized solar cell of the present invention, the outer periphery of the sealing material layer or the outer periphery of the cell may be reinforced with an epoxy or acrylic adhesive.

  In the dye-sensitized solar cell of the present invention, leakage of the electrolytic solution can be efficiently prevented by setting the sealing material layer to a width of 2 mm or more in the longitudinal direction and a thickness of 1 to 40 μm. Further, since the width and thickness of the sealing material layer can be known in advance depending on the sealing material used, the entire dye-sensitized solar cell can be easily designed.

  In addition, when a reactive sealant mainly composed of an isobutylene resin or a reactive sealant mainly composed of a polybutadiene resin is used, it is possible to prevent leakage of the electrolyte solution. Can greatly improve the reliability. Further, unlike a general sealing resin in a dye-sensitized solar cell using a thermoplastic sealant used in Patent Documents 30, 31, 32, 33, etc., the resin used in the present invention has a low Tg. Therefore, it is expected that the adhesion with the electrode can be maintained over a long period of time in a cold environment such as a heat cycle, which greatly contributes to improving the reliability of the battery.

  Hereinafter, the present invention will be described in detail using examples, but the present invention is not limited to the following examples.

[Preparation of Reactive Sealant A Containing Isobutylene Resin as Main Component]
(A) component

(B) component

Formula 5
m and n are integers of 3 to 10, R ₁ and R ₂ are alkyl groups having 3 to 20 carbon atoms (C) component bis (1,3-divinyl-1,1,3,3-tetramethyldisiloxane) platinum Catalyst (8.3 × 10 ⁻⁵ mmol / μl, xylene solution)
Component (D) 3-Glycidoxypropyltrimethoxysilane (trade name: A-187 manufactured by Nihon Unicar)

Weighed so that the ratio of the amount of alkenyl groups in component (A) to the amount of Si-H groups in component (B) is 1.0: 2.0, and process oil (product of Idemitsu Kosan Co., Ltd. Name: 50 parts by weight of PAO5010) with respect to 100 parts by weight of component (A), and 3 parts by weight of MARKAO-50 (manufactured by Adeka Argus Chemical Co.) as an antioxidant with respect to 100 parts by weight of component (A). 50 parts by weight of carbon (manufactured by Nippon Silica Kogyo Co., Ltd.) was weighed with respect to 100 parts by weight of the component (A), and stirred and degassed. Subsequently, 4.3 parts by weight of 3-glycidoxypropyltrimethoxysilane as a component (D) was weighed and mixed with respect to 100 parts by weight of the component (A). Further, 30 mol equivalent of dimethyl malate as platinum as a storage stability improving agent and bis (1,3-divinyl-1,1,3,3-tetramethyldisiloxane) platinum catalyst (8. 3 × 10 ⁻⁵ mmol / μl, xylene solution) was weighed so that platinum was 5 × 10 ⁻⁴ equivalents relative to the number of moles of the alkenyl group of component (A), and a composition was mixed uniformly to prepare Subsequently, 3% by weight of glass spheres (manufactured by Catalyst Chemical Industry Co., Ltd.) having a particle size of 40 μm were added and stirred as a gap material (spacer material) of component (E) to obtain a sealant.

[Adjustment of reactive sealant B mainly composed of polybutadiene resin]
100 parts by weight of TEAI1000 (manufactured by Nippon Soda Co., Ltd.) as a polymer (X) having a polybutadiene skeleton having a (meth) acryl group at its terminal and a hydrogenated main skeleton, and polybutene 300H (as saturated aliphatic elastomer (Y)) 50 parts by weight of Idemitsu Kosan Co., Ltd., 50 parts by weight of isobornyl acrylate (Osaka Organic Industries) as the component (Z), and Irgacure 184 (manufactured by Ciba Specialty Chemicals) as a photopolymerization initiator in a mixer The mixture was stirred at 50 ° C. for 1 hour to prepare a uniformly mixed composition, and then 3% by weight of glass spheres (catalyst chemical industry) having a particle size of 40 μm were added and stirred as the gap material (spacer material) of component (E). Thus, a sealant was obtained.

[Create pseudo cell]
The sealing agent A and the sealing agent B prepared previously were applied on a 3 cm × 3 cm glass plate so as to draw a 2.5 cm × 2.5 cm square with a predetermined seal width shown below (Three Bond is used for coating). Use TRC120 robot). After coating, a glass plate with 2 holes of 1Φ (diameter 1 mm) is pasted on another 3cm x 3cm glass plate, sealing agent A is 100 ° C x 30 minutes, sealing agent B is 3000mJ / cm ² Light irradiation was performed with the amount of light produced, and each sealant was cured. Thereafter, an electrolyte (acetonitrile-based electrolyte: 0.05 mol / L of iodine and 0.03 mol / L of potassium iodide added in acetonitrile) is sufficiently injected from the hole, and a sealant is formed around each injection hole. B was applied, and further laminated light irradiation was performed with another glass plate of 3 cm × 3 cm (a three-layer structure of a gas plate). The sealing property of the electrolytic solution was calculated by the leakage amount of the electrolytic solution sealed by this method (weight change from the initial stage).

[Electrolytic solution leakage test conditions]
The following test was performed using the pseudo cell prepared by the previous method, and the superiority or inferiority of the sealing performance was determined by confirming the leakage of the electrolyte.
Heat resistance: left at a constant temperature of 60 ° C. for 96 hours.
Moisture resistance: It was allowed to stand for 96 hours under high temperature and high humidity of 60 ° C. × 95%.
Heat cycle property: 200 cycles of reciprocation of −40 × 30 minutes and 60 ° C. × 30 minutes were performed.
Weather resistance: A sunshine weatherometer was used for 48 cycles of 102 minutes of sunshine and 18 minutes of rainfall.

  In the pseudo cell using the sealing agent A and the sealing agent B adjusted as described above, each environmental test was performed with the seal width after coating and curing being 1, 1.5, 2, 5, 7 (mm), The liquid leakage is observed and the results are shown in Tables 1-4.

Table 2 shows a graph of Table 1 above.

Table 4 shows a graph of Table 3 above.

  Various environmental tests were conducted using sealant A and sealant B. When acetonitrile-based electrolyte was used, both the sealant A and B had a significant difference in leakage rate due to the seal width, and the seal width was Inflection points were observed when moving from 1.5 mm to 2 mm.

  Next, a pseudo-cell of a dye-sensitized solar cell was manufactured in the same manner as described above by changing the sealing material gap (the thickness of the cured product layer) of the sealing agent A and the sealing agent B, and the sealing material width and the sealing material thickness The relationship was examined for the electrolyte leakage rate (%). The results are summarized in Table 5.

Tables 6 and 7 below are graphs of Table 5 shown above for each type of sealing material.

  From the results of Tables 5 to 7, it can be seen that the leakage of the electrolyte can be effectively obtained when the thickness of the sealing material is 40 μm or less and the sealing material width is 2 mm or more.

  Furthermore, using the sealant B, the seal width and leakage rate (%) of the system in which the type of the electrolyte was changed was subjected to a weather resistance test (a cycle of 102 minutes of sunshine with a sunshine weatherometer and 48 cycles of 18 minutes of rainfall). The electrolyte leakage rate was measured. The results are shown in Table 8. In this test, a pseudo cell of a dye-sensitized solar cell was manufactured in the same manner as described above, and the thickness of the sealing material was 40 μm.

Table 9 shows a graph of the results of Table 8.

From the results of Tables 8 and 9, it can be seen that the leakage rate varies depending on the type of the electrolytic solution, but has a good sealing property if the width of the sealing material is 2 mm or more.

  Next, using the sealing agent B, the electrolyte solution was 3-methoxypropionitrile-based (iodine 0.05 mol / L, potassium iodide 0.03 mol / L, imidazolium salt in 3-methoxypropionitrile). 0.01 mol / L added), and a weather resistance test when the seal material thickness is 40 μm (a cycle of 102 minutes of sunshine and 18 minutes of rain using a sunshine weatherometer) is 96 hours (48 Cycle), 120 hours (60 cycles), and 360 hours (180 cycles) at different times, and the electrolyte leakage rate was measured. The results are shown in Table 10. This test was also conducted by manufacturing a pseudo cell of a dye-sensitized solar cell in the same manner as described above.

Table 11 shows a graph of the results of Table 10.

From the results of Tables 10 and 11, it can be seen that the electrolyte leakage by the weather resistance test greatly affects the decrease in the electrolyte leakage rate when the seal material width is 2 mm or more.

  In the present invention, the seal structure described in claims 3 and 5 controls not only the dye-sensitized solar cell but also the leakage of the encapsulated material. In other words, it can be used as a sealing method in a general organic semiconductor. For example, the present invention can be applied to organic EL elements, Schottky pn elements, organic radical pn elements, solid pn elements, liquid crystal driving elements, and the like.

It is the schematic which shows the pseudo dye-sensitized solar cell in the Example of this invention. It is the schematic which shows a dye-sensitized solar cell. It is the schematic which shows a dye-sensitized solar cell.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Sealing agent before hardening 12 Glass plate 14 Glass plate provided with injection hole 16 Electrolyte injection hole

Claims (7)

Electrode part (A), electrode part (B), and electrolyte solution (C) on which a porous metal oxide semiconductor film adsorbing a photosensitizer is laminated are sealed between two plates through a sealing material layer. A dye-sensitized solar cell in which at least one of the two plates has light transmittance, and the sealing material layer is a reactive seal mainly composed of the following components (A) to (E): A dye-sensitized solar cell, wherein the dye-sensitized solar cell is formed with an agent at a width of 2 mm or more and a thickness of 1 to 40 μm.
Component (A): an isobutylene-based polymer containing in the molecule at least one alkenyl group capable of hydrosilylation reaction
(B) component: Organohydrogenpolysiloxane
Component (C): hydrosilylation catalyst
(D) component: Silane coupling agent
(E) Component: Gap material of spherical glass Electrode part (A), electrode part (B), and electrolyte solution (C) on which a porous metal oxide semiconductor film adsorbing a photosensitizer is laminated are sealed between two plates through a sealing material layer. A dye-sensitized solar cell, wherein at least one of the two plates has light transmittance, and the sealing material layer is a reactive seal mainly comprising the following components (X) to (Z): A dye-sensitized solar cell, wherein the dye-sensitized solar cell is formed with an agent at a width of 2 mm or more and a thickness of 1 to 40 μm.
Component (X): hydrogenated polybutadiene acrylate oligomer
(Y) component: saturated aliphatic elastomer
(Z) component: a chain aliphatic or alicyclic monofunctional (meth) acrylate having 5 or more carbon atoms The dye-sensitized solar cell which further contains the gap material of spherical glass in the reactive sealing agent which has (X)-(Z) component of Claim 2 as a main component. The dye-sensitized solar cell, dye-sensitized solar cell according to any one of claims 1 to 3 is the area 1~500cm ^2. The dye sensitization according to any one of claims 1 to 3, wherein the electrolytic solution used in the dye-sensitized solar cell is one or a mixture of ether, nitrile, lactone, and carbonate. Type solar cell. The dye-sensitized solar cell according to any one of claims 1 to 3, wherein the light-transmitting plate is made of glass. The dye-sensitized solar cell according to any one of claims 1 to 3, wherein the light-transmitting plate is made of plastic.