JP2003217690A - Dye-sensitized solar battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dye-sensitized solar battery having excellent durability by finding an ultraviolet shield layer capable of keeping high energy conversion efficiency in spite of a long time exposure to the sunlight. <P>SOLUTION: In this dye-sensitized type solar battery, an ultraviolet shield layer is formed on the light incident plane side. The ultraviolet shield layer is formed of an ultraviolet shield layer forming resin composition containing polymers composed of a monomer mixture (I) containing a monomer having an ultraviolet absorptive group, a monomer having an alkyl group with a carbon number of 4 or more and/or a monomer having an ultraviolet stable group, or an ultraviolet shield layer forming resin composition containing a polymer composed of a monomer mixture (II) containing a monomer having an alkyl group with a carbon number of 4 or more and/or a monomer having an ultraviolet stable group and an addition type ultraviolet absorbent. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dye-sensitized solar cell provided with an ultraviolet shielding layer, which has a UV shielding ability which does not deteriorate even when used for a long period of time and which can maintain a high electromotive force. The present invention relates to a sensitized solar cell.

[0002]

2. Description of the Related Art A solar cell is a cell that is capable of directly converting its energy into electric energy when it is irradiated with light such as sunlight, and is a type of photoelectric conversion element utilizing the photovoltaic effect. is there. In addition to amorphous silicon solar cells, solar cells include dye-sensitized solar cells that have recently been spotlighted.

This dye-sensitized solar cell is formed by using a metal oxide semiconductor as a photoelectrode and sandwiching an electrolyte having a redox couple between it and a counter electrode. The metal oxide semiconductor is made porous. Since the energy conversion efficiency has been remarkably improved by adsorbing the dye on the surface of the steel, further studies are being conducted toward full-scale practical use.

One of the problems to be investigated in the dye-sensitized solar cell is the problem of extending the life and ensuring the durability. For example, titanium dioxide, which is often used as a metal oxide-based semiconductor, has a photocatalytic action of decomposing organic matter when excited by light (especially ultraviolet rays), and thus the dye adsorbed on the surface of titanium dioxide has this action. The problem is that it gradually decomposes, and the energy conversion efficiency gradually decreases.

In order to solve the above-mentioned problems, a proposal has been made that a constituent member such as a solar cell module contains an ultraviolet absorber (Japanese Patent Laid-Open No. 62-273780).
However, in this conventional technique, since the absorption capacity of the ultraviolet absorber decreases with time, there is still room for improvement in terms of ensuring the durability of the dye-sensitized solar cell.

[0006]

Therefore, according to the present invention,
The subject was to find a UV-shielding layer that can maintain high energy conversion efficiency even when exposed to sunlight for a long time, and to improve the durability of the dye-sensitized solar cell.

[0007]

A first type of dye-sensitized solar cell according to the present invention is a dye-sensitized solar cell having an ultraviolet shielding layer formed on the light incident surface side. The ultraviolet shielding layer is a monomer having an ultraviolet absorbing group,
It is formed from a resin composition for forming an ultraviolet shielding layer containing a polymer synthesized from a monomer mixture (I) containing a monomer having an alkyl group having 4 or more carbon atoms and / or a monomer having an ultraviolet stable group. Characterize.

Since the monomer mixture (I) contains a monomer having an alkyl group having 4 or more carbon atoms or a monomer having an ultraviolet stable group, the ultraviolet absorbing group of the monomer having an ultraviolet absorbing group is Since it was possible to prevent decomposition by ultraviolet rays for a long period of time, we succeeded in improving the durability of the dye-sensitized solar cell. Further, in the first type, since the ultraviolet absorbing group can be incorporated into the polymer chain, the ultraviolet shielding ability at a high level for a long period of time is higher than that of the second type using the additive type ultraviolet absorber. Can be maintained.

Second aspect of the dye-sensitized solar cell according to the present invention
Type is a dye-sensitized solar cell in which an ultraviolet shielding layer is formed on the light incident surface side, and the ultraviolet shielding layer is
A resin composition for forming an ultraviolet shielding layer containing a polymer synthesized from a monomer mixture (II) containing a monomer having an alkyl group having 4 or more carbon atoms and / or a monomer having an ultraviolet stable group, and an additive type ultraviolet absorber. It is characterized by being formed from a thing.

Since the monomer mixture (II) also contains a monomer having an alkyl group having 4 or more carbon atoms or a monomer having an ultraviolet stable group, the ultraviolet absorber is decomposed by ultraviolet rays for a long period of time. And the durability of the dye-sensitized solar cell could be improved.

The above monomer mixture (I) or (II) is
Further, it may contain a monomer having a crosslinkable functional group, and if a crosslinking agent is used, the chemical resistance and water resistance of the ultraviolet shielding layer can be improved.

In the case where the photoelectrode substrate of the dye-sensitized solar cell is made of glass and the ultraviolet shielding layer is directly formed on the glass substrate, the ultraviolet shielding layer forming resin composition further comprises silane. It is preferable to contain a coupling agent because the adhesion between the glass substrate and the ultraviolet shielding layer will be further improved.

Of course, the photoelectrode substrate of the dye-sensitized solar cell may be made of plastic, and the UV-shielding layer is formed directly or indirectly on the plastic substrate. Batteries are also included within the scope of the invention.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The inventors of the present invention have studied the ultraviolet absorbing ability of organic ultraviolet absorbers, and as a result, have found that an ultraviolet absorbing group having the ability to absorb ultraviolet rays is exposed to ultraviolet rays for a long period of time. It was discovered that it would lose its ability to absorb UV light due to decomposition. As a result of further study, by using a monomer having an alkyl group having 4 or more carbon atoms or a monomer having an ultraviolet stable group, although the reason is not clear, decomposition of the ultraviolet absorbing group can be suppressed as much as possible, The inventors have found that it is possible to maintain a high level of ultraviolet absorbing ability for a long period of time and have reached the present invention. Hereinafter, the present invention will be described in detail. In the present invention, "monomer" means a radically polymerizable monomer, and "polymer"
The term means not only a homopolymer but also a copolymer or a ternary or higher copolymer.

In the dye-sensitized solar cell of the first type of the present invention, the polymer synthesized from the monomer mixture (I) is the main component of the resin composition for forming an ultraviolet shielding layer. In this monomer mixture (I), a monomer (A) having an ultraviolet absorbing group and a monomer (B) having an alkyl group having 4 or more carbon atoms and / or a monomer (C) having an ultraviolet stable group are essential. Included. In addition, the second type of dye-sensitized solar cell is a monomer mixture (II) containing as an essential component a monomer (B) having an alkyl group having 4 or more carbon atoms and / or a monomer (C) having an ultraviolet stable group. From a resin composition for forming an ultraviolet shielding layer containing a polymer synthesized from), and an addition type ultraviolet absorber,
It forms an ultraviolet ray shielding layer. Hereinafter, each raw material will be described.

(A) Monomer Having Ultraviolet Absorbing Group As the monomer (A) having an ultraviolet absorbing group, all monomers having a radical polymerizable double bond and an ultraviolet absorbing group in the molecule at the same time can be used. Particularly preferably used in the present invention is the following general formula (A-1) to
It is at least one kind selected from the monomers represented by (A-3), and by using these monomers as a copolymerization component, the resulting polymer is provided with an ultraviolet absorbing ability. That is, even if the obtained coating film is irradiated with ultraviolet rays, the ultraviolet rays are absorbed by the shielding layer, so that it is possible to suppress the decomposition of the dye by the metal oxide semiconductor located below the shielding layer. Compared to the second type using the additive type ultraviolet absorber, since the ultraviolet absorber hardly bleeds out, the durability of the ultraviolet shielding performance is enhanced.

[0017]

[Chemical 1]

(In the formula, R ¹ represents a hydrogen atom or a carbon number of 1 to
8 represents a hydrocarbon group, R ² represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group or a nitro group, and R ³ has 1 to 1 carbon atoms. Represents a straight-chain or branched-chain alkylene group having 12 or —O—R′— (R ′ is a straight-chain or branched-chain alkylene group having 2 or 3 carbon atoms);
⁴ represents a hydrogen atom or a methyl group), a benzotriazole-based monomer (A-1).

[0019]

[Chemical 2]

(Wherein R ¹ and R ⁴ have the same meanings as above, R ⁵ represents a hydrogen atom or a hydroxyl group, R ⁶ represents a hydrogen atom or an alkoxy group having 1 to 6 carbon atoms, and R ⁷ represents A benzophenone-based monomer represented by a linear or branched alkylene group having 1 to 12 carbon atoms (A-
2).

[0021]

[Chemical 3]

(In the formula, R ⁴ has the same meaning as described above, and R ⁸
Bond _{directly, - (CH 2 CH 2 O} ) p - or -CH ₂ CH
(OH) -CH ₂ O- and represent, p is an integer of 1-5. R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶
Each independently represent a hydrogen atom, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group or an alkyl group. ) A triazine-based monomer represented by (A-3).

Specific preferred examples of the monomer (A-1) include 2- [2'-hydroxy-5 '-(meth) acryloyloxymethylphenyl] -2H-benzotriazole and 2- [2'-hydroxy-]. 5 '-(meth) acryloyloxyethylphenyl] -2H-benzotriazole, 2- [2'-hydroxy-5'-(meth) acryloyloxypropylphenyl] -2H-benzotriazole, 2- [2'-hydroxy- 5 '-(meth) acryloyloxyhexylphenyl] -2H-benzotriazole, 2- [2'-hydroxy-3'-tert-butyl-5'-(meth) acryloyloxyethylphenyl] -2H-benzotriazole, 2 -[2'-hydroxy-5 '-(β- (meth) acryloyloxyethoxy) -3'-tert-butyl Phenyl] -5-ter
Examples thereof include t-butyl-2H-benzotriazole and the like.

Specific examples of the monomer (A-2) include 2
-Hydroxy-4- [2- (meth) acryloyloxy] ethoxybenzophenone, 2-hydroxy-4- [2- (meth) acryloyloxy] butoxybenzophenone, 2,
2'-dihydroxy-4- [2- (meth) acryloyloxy] ethoxybenzophenone, 2-hydroxy-4- [2
-(Meth) acryloyloxy] ethoxy-4 '-(2-hydroxyethoxy) benzophenone, 2-hydroxy-
3-tert-butyl-4- [2- (meth) acryloyloxy] ethoxybenzophenone, 2-hydroxy-3
Examples thereof include -tert-butyl-4- [2- (meth) acryloyloxy] butoxybenzophenone.

Specific examples of the monomer (A-3) include 2,4-diphenyl-6- [2-hydroxy-4-].
(2-Acryloyloxyethoxy)]-s-triazine, 2,4-bis (2-methylphenyl) -6- [2-hydroxy-4- (2-acryloyloxyethoxy)]-
s-triazine, 2,4-bis (2-methoxyphenyl)
-6- [2-hydroxy-4- (2-acryloyloxyethoxy)]-s-triazine and the like can be mentioned.

When the monomer (A-1) and / or the monomer (A-2) is used, if an alkali metal or a basic compound having a strong basicity coexists in the ultraviolet shielding layer,
Since the problem of coloring of the ultraviolet shielding layer and deterioration of the ultraviolet absorbing performance over time are likely to occur, R ¹ in each general formula is at the 3rd position, which is a position adjacent to the OH group, from the viewpoint of suppressing these, It is particularly preferable to use a monomer having an alkyl group having 4 to 8 carbon atoms.

The above-mentioned monomer having an ultraviolet absorbing group (A
Since each of -1) to (A-3) has an ultraviolet absorption characteristic peculiar to the compound, it may be used alone or in combination of two or more kinds depending on the required ultraviolet shielding performance. preferable.

Various metal oxide semiconductors have a characteristic deterioration wavelength. For example, titanium dioxide absorbs ultraviolet rays having a wavelength of 410 nm or less, and all the wavelengths cause a photocatalytic action, so that the triazine monomer (A- It is preferable to use the benzophenone-based monomer (A-2) and the benzotriazole-based monomer (A-1) each independently, rather than using 3) alone. Most preferably, the monomer (A-1) or (A-2) and the monomer (A-
It is a combination pattern of 2 kinds with 3).

A polymer obtained by polymerizing each of the above-mentioned UV-absorbing group-containing monomers (A-1) to (A-3) alone or by appropriately copolymerizing two or more of them is used alone or Two or more kinds may be contained in the resin composition for forming an ultraviolet shielding layer.

The monomer mixture (I) must contain either one or both of a monomer (B) having an alkyl group having 4 or more carbon atoms and a monomer (C) having an ultraviolet stable group. These are those in which the UV absorbing group of the monomer (A) having the above UV absorbing group or the UV absorbing group of the addition type UV absorber described below is gradually photodegraded by long-term UV exposure. Has the effect of preventing.

(B) Having an alkyl group having 4 or more carbon atoms
Monomer As the monomer (B), specifically, a (meth) acrylate-based monomer represented by the following general formula is preferably used.

[0032]

[Chemical 4]

(In the formula, R ¹⁷ represents a hydrogen atom or a methyl group, and X represents a hydrocarbon group having 4 or more carbon atoms).

In the above formula, the substituent represented by X is a cycloaliphatic hydrocarbon group having 4 or more carbon atoms such as cyclohexyl group, methylcyclohexyl group and cyclododecyl group; butyl group, isobutyl group and tert-butyl group. , A 2-ethylhexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a pentadecyl group, an octadecyl group and the like, which is a linear or branched alkyl group having 4 or more carbon atoms; a bornyl group , An isobornyl group and other polycyclic hydrocarbon groups having 4 or more carbon atoms, among which an alicyclic hydrocarbon group, a branched alkyl group, and a linear alkyl group having 6 or more carbon atoms are preferable.

Specific examples of the monomer (B) include cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate, tert-butylcyclohexyl (meth) acrylate and isobutyl (meth). Non-limiting examples include acrylate, tert-butyl (meth) acrylate, lauryl (meth) acrylate, isobornyl (meth) acrylate, stearyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and one or two of these. More than one species can be used.

(C) Monomer Having UV-Stable Group Copolymerizing the monomer (C) having an UV-stable group exerts the above-mentioned effect of suppressing photodegradation of the UV-absorbing group, and also a UV-shielding layer. UV-stability is imparted to and the shielding effect is further enhanced. The UV-stable group-containing monomer (C) is not particularly limited in its kind as long as it has a radical-polymerizable double bond and a UV-stable group in the molecule at the same time. It is a monomer represented by the formula (C-1) or (C-2).

[0037]

[Chemical 5]

(In the formula, R ¹⁸ represents a hydrogen atom or a cyano group, R ¹⁹ and R ²⁰ each independently represent a hydrogen atom or a methyl group, R ²¹ represents a hydrogen atom or a hydrocarbon group, and Y represents Y. Represents an oxygen atom or imino group.)

[0039]

[Chemical 6]

(Wherein R ²² represents a hydrogen atom or a cyano group, R ²³ , R ²⁴ , R ²⁵ and R ²⁶ each independently represent a hydrogen atom or a methyl group, and Z represents an oxygen atom or an imino group. Represent.).

Specific examples of the above-mentioned monomer (C-1) include 4- (meth) acryloyloxy-2,2,6,6.
-Tetramethylpiperidine, 4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 4
-(Meth) acryloyloxy-1,2,2,6,6-
Pentamethylpiperidine, 4- (meth) acryloylamino-1,2,2,6,6-pentamethylpiperidine,
4-cyano-4- (meth) acryloylamino-2,
2,6,6-tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine,
Non-limiting examples include 4-crotonoylamino-2,2,6,6-tetramethylpiperidine and the like, and these may be used alone or in combination of two or more if necessary.

Specific examples of the monomer (C-2) include 1- (meth) acryloyl-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine and 1- (meth) acryloyl- 4-cyano-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 1-crotonoyl-4-crotonoyloxy-2,2,6,6-tetramethylpiperidine and the like are not limited. These may be used alone or, if necessary, two or more kinds may be appropriately combined and used.

The monomer mixture (I) used for synthesizing the polymer which is the main component of the first resin composition for forming an ultraviolet-shielding layer of the present invention contains the monomer having an ultraviolet-absorbing group described above ( A) and a monomer (B) having an alkyl group having 4 or more carbon atoms and / or a monomer (C) having an ultraviolet stable group are included as essential monomers. On the other hand, in the monomer mixture (II) used in the second type of the present invention, the monomer (B) having an alkyl group having 4 or more carbon atoms and / or the monomer (C) having an ultraviolet stable group is an essential component. is there. Since the second type resin composition contains an additive type ultraviolet absorber, which will be described later, as an essential component, it is not necessary to use the monomer (A) having an ultraviolet absorbing group as an essential monomer. However, the monomer mixture (II) may contain the monomer (A).

In the monomer mixture (I) or the monomer mixture (II), in addition to the above-mentioned essential monomers, the following various monomers may be used in combination as necessary for appropriately changing the physical properties of the ultraviolet shielding layer. .

(D) Other Monomer Specific examples of the other monomer (D) include (meth) acrylate (D-) having an alkyl group having 3 or less carbon atoms such as methyl (meth) acrylate and ethyl (meth) acrylate. 1) are preferred. These monomers (D-1) are the above-mentioned monomers (A) to
It is excellent in copolymerizability with (C), plays a role of forming a hard shielding layer having excellent water resistance and mechanical strength, and is inexpensive and easy to use. Of these, methyl methacrylate, which has a high homopolymer Tg, is particularly preferable.

Further, a monomer having a crosslinkable functional group (D
-2) may be used to synthesize a polymer and a curing agent (crosslinking agent) may be added separately to crosslink the ultraviolet shielding layer. Specific examples of the monomer (D-2) having a crosslinkable functional group include monomers having a carboxyl group such as (meth) acrylic acid, itaconic acid and maleic anhydride; 2
-Acid phosphate monomers such as (meth) acryloyloxyethyl acid phosphate; glycidyl (meth) acrylate, methylglycidyl (meth) acrylate, alicyclic epoxy group-containing (meth) acrylate (for example, manufactured by Daicel Chemical Industries, Ltd .; Product name "CYCLO
Epoxy group-containing (meth) acrylate such as MER M-100 "; 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, hydroxyl group-terminated flexible (meth) acrylate (for example, Daicel Chemical Industries Ltd.) A monomer having an active hydrogen (hydroxyl) group such as manufactured by the company; trade name "Placcel FM") can be used. Among these, it is preferable to use a hydroxyl group-containing monomer, add polyisocyanate as a curing agent to the ultraviolet ray shielding layer resin composition, and crosslink the ultraviolet ray shielding layer by the reaction of the hydroxyl group and the isocyanate group.

As the other monomer, (meth)
Nitrogen-containing monomers such as acrylamide, imide (meth) acrylate, N-methylol (meth) acrylamide;
It is also possible to use a monomer having two polymerizable double bonds such as ethylene glycol di (meth) acrylate; a halogen-containing monomer such as vinyl chloride; an aromatic monomer such as styrene and α-methylstyrene; and vinyl ether.

(E) Reactive Silyl Group-Containing Monomer The monomer mixture (I) or (II) may contain a reactive silyl group-containing monomer (for convenience, referred to as a monomer (E)). The monomer (E) acts as a crosslinkable functional group-containing monomer, and when a polymer synthesized using this is used for the ultraviolet shielding layer, for example, the base material of the solar cell is glass, and the ultraviolet shielding layer is directly glass-coated. This is a preferred embodiment because the adhesion between the glass substrate and the ultraviolet shielding layer is enhanced when it is formed on the substrate.

The reactive silyl group-containing monomer (E) is
It is a monomer having a polymerizable double bond and having a reactive silyl group at least at the terminal. Then, the type (E-1) in which the terminal reactive silyl group is directly bonded to the carbon atom in the monomer and the terminal reactive silyl group through a polysiloxane bond which may have a substituent. , And a type (E-2) in which a carbon atom in a monomer is linked, and any of them can be used. Monomer (E-
2) is obtained by reacting the monomer (E-1) with an organic silane compound. The ordinary polysiloxane bond is —SiH ₂ —O—SiH ₂ —O—, but the polysiloxane bond in the monomer (E-2) may have a substituent. That is, any one or more hydrogen atoms bonded to Si may be substituted with an alkoxy (alkyloxy) group having 1 to 6 carbon atoms or an alkyl group having 1 to 10 carbon atoms. Of course, each substituent may be the same or different. If an alkoxy group is present as a substituent, a reactive silyl group is also present in the polysiloxane bond portion. In addition, a reactive silyl group means a hydrolyzable silyl group, and means all functional groups capable of generating a silanol (Si—OH) group by a hydrolysis reaction.

The monomer (E-1) having a reactive silyl group directly bonded to a carbon atom has a polymerizable double bond and a reactive silyl group directly bonded to a carbon atom. Specific examples are represented by the following general formulas (E-1-1) to (E-1-3).

[0051]

[Chemical 7]

(In the formula, R ²⁷ represents a hydrogen atom or a methyl group, R ²⁸ represents a hydrocarbon group having 1 to 6 carbon atoms, and a
Is an integer of 1 to 5 and b represents 0 or 1.)

[0053]

[Chemical 8]

(Wherein R ²⁹ has the same meaning as R ²⁸ or represents an alkyloxyalkyl group, and c is 0 or 1)
Represents)

[0055]

[Chemical 9]

(In the formula, R ³⁰ has the same meaning as R ^28, and d represents 0 or 1.)

The monomer (E-1-1) is a monomer having a hydrolyzable alkoxysilyl group and a (meth) acryloyl group and has 1 to 1 carbon atoms in each general formula.
The hydrocarbon group 6 represents an alkyl group such as a methyl group, an ethyl group and a propyl group; an alkenyl group such as a vinyl group, an isopropenyl group and an allyl group; and an aryl group such as a phenyl group.

Specific examples of the monomer (E-1-1) include 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltriethoxysilane and 3- (meth) acryloxypropyltrimethoxysilane. Examples include butoxysilane, 3- (meth) acryloxypropyltriisopropenoxysilane, (meth) acryloxymethyltrimethoxysilane, (meth) acryloxymethyltriethoxysilane, and (meth) acryloxymethyltributoxysilane. .

Considering the ease of handling, reactivity, crosslink density, etc., 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxytriethoxysilane, 3- (meth) are particularly preferable. It is acryloxypropylmethyldimethoxysilane. In terms of copolymerizability with the monomers (A) to (C), it has a (meth) acryloyl group rather than the vinyl-functional monomer (E-1-2) or (E-1-3) (E). 1-1) is preferred.

The monomer (E-1-2) is a vinyl functional monomer having a vinyl group and a hydrolyzable alkoxysilyl group, and the monomer (E-1-3) is a vinyl functional alkoxysilane compound. is there.

Examples of the monomer (E-1-2) include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, vinylmethyldimethoxysilane and vinylmethyldiethoxysilane. Examples of 3) include 3-vinyloxypropyltrimethoxysilane, 3-vinyloxypropyltriethoxysilane and 3-vinyloxypropylmethyldimethoxysilane. Among these, vinyltrimethoxysilane, vinyltriethoxysilane, 3-vinyloxypropyltrimethoxysilane and the like are preferable from the viewpoint of easy handling and reactivity.

By reacting the organosilane compound with the above-mentioned monomer (E-1) having a reactive silyl group directly bonded to a carbon atom, the terminal reactive silyl group is introduced into the monomer via the polysiloxane bond. A monomer (E-2) having a structure bonded to a carbon atom is obtained. The organic silane compound that can be used is an organic silane compound represented by the following general formula and / or its hydrolysis-condensation product.

R ³¹ _m Si (OR ³² ) _n (E) (In the formula, R ³¹ may be the same or different and may be a hydrogen atom, a lower alkyl group, an aryl group, a vinyl group or a mercapto directly bonded to a carbon chain. Or a methacryloyl group, R ^{32 s} may be the same or different and each represents a hydrogen atom, a lower alkyl group or an acyl group, m is 0 or a positive integer, n is an integer of 1 or more, and m + n is Si. Matches the valence of

Specifically, tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltributoxysilane, ethyltrimethoxysilane. , Ethyltriethoxysilane, ethyltriisopropoxysilane, ethyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldiisopropoxysilane, dimethyldibutoxysilane,
Examples thereof include diethyldimethoxysilane, diethyldiethoxysilane, diethyldiisopropoxysilane, diethyldibutoxysilane and the like, or high molecular weight organic silane compounds containing these compounds, and one or more of these can be used. .

The organosilane compound can be used for the synthesis of the monomer (E-2), but for the modification of the polymer, the reactive silyl group of the polymer synthesized using the monomer (E-1) is reacted with the organosilane compound. It can also be used.
In any case, in terms of excellent reactivity and an effect of hardening the ultraviolet shielding layer, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, and dimethyldiethoxysilane are preferable.

The above-mentioned monomer having a reactive silyl group (E
In the reaction of -1) with the organic silane compound, it is desired to introduce -O into the side chain of the reactive silyl group-containing monomer (E-2).
The amount of organosilane compound is adjusted by the number of -Si bonds. For example, when it is desired to introduce five —O—Si bonds on average, it is preferable to react the monomer (E-1) so that the amount of the organic silane compound becomes 5 moles.
Here, the total of (E-1) and the organic silane compound is 10
When the content of (E-1) exceeds 30 mol% in the case of 0 mol%, a large number of polymerizable double bonds are introduced into the resulting monomer (E-2), and the monomer mixture (I) or When the (II) is polymerized, it easily gels. (E-
When the content of 1) is less than 0.1 mol%, the polymerizable double bond may not be introduced into (E-2), which is not preferable. The preferred double bond amount in (E-2) is 1
The range is 1 to 4 per molecule.

The reaction between the two is carried out by mixing (E-1) and the organic silane compound. If necessary, a solvent such as methanol or water may be used. Alcohol is produced according to the progress of the hydrolysis-condensation reaction. Therefore, it is advisable to carry out the reaction at 50 to 100 ° C. for 10 minutes to 5 hours while distilling off the alcohol. If the reaction is carried out at a high temperature or for a long time, the polymerization of (E-2) may occur. In addition,
The pressure is preferably about 0.13 Pa to 1.0 MPa.

A catalyst is preferably used in order to increase the rate of the hydrolysis-condensation reaction, and a solid catalyst which is easily separated is suitable. As a solid catalyst, "Amberlyst 1
5 "," Amber Light 15 "," Amber Light 20 "
0C "(both are trade names; manufactured by Rohm and Haas Co.) and the like are preferable. The amount of the catalyst used is not particularly limited, but (E-1)
0.1 to 20 mass% is preferable with respect to the total amount of the organic silane compound. These synthetic reactions are described in further detail in Japanese Patent No. 2721106. Further, when the reactive silyl group of the polymer synthesized using the monomer (E-1) is reacted with an organic silane compound to modify the polymer, the reaction may be appropriately performed with reference to the above reaction conditions.

The above are the monomers which can be used as the monomer mixture (I) and the monomer mixture (II). Incidentally, the monomer mixture (I) and the monomer mixture
In (II), each monomer (D) to be used as necessary
One or more kinds of (E) can be appropriately selected,
These may be common or different in the monomer mixtures (I) and (II).

The preferred amounts of each monomer that can be used in the monomer mixture (I) are as follows: The following range of amounts is a guideline for the preferable amount of each monomer used when the total amount of the monomers used is 100% by mass.

A monomer (A) having an ultraviolet absorbing group;
0.1 mass% or more (more preferably 3 mass% or more), 6
0 mass% or less (more preferably 40 mass% or less), a monomer (B) having an alkyl group having 4 or more carbon atoms; 3 mass% or more (more preferably 5 mass% or more), 90 mass% or less (more preferably) 80 mass% or less), a monomer (C) having an ultraviolet stable group; 0.1 mass% or more (more preferably 0.5 mass% or more), 20 mass% or less (more preferably 10 mass% or less), and others Monomer (D); adjusted appropriately, reactive silyl group-containing monomer (E); 50% by mass or less (more preferably 30% by mass or less).

The preferred amount of each monomer that can be used in the monomer mixture (II) is also the same as the preferred amount of the monomers (B) to (E) in the monomer mixture (I).

Next, a method for producing the resin composition of the present invention will be described. First, the polymer, which is the main component of the resin composition,
It is synthesized by polymerizing the above-mentioned monomer mixture (I) or (II).

The polymerization method is not particularly limited, and known polymerization methods such as solution polymerization method, dispersion polymerization method, suspension polymerization method and emulsion polymerization method can be used. The solution polymerization method is a preferable polymerization method because the resin composition can be obtained as it is or by simply diluting the obtained reaction product. Solvents used for solution polymerization include toluene, xylene, and other aromatic solvents; alcohol solvents such as n-butyl alcohol, propylene glycol methyl ether, diacetone alcohol, ethyl cellosolve; butyl acetate, ethyl acetate, cellosolve. Ester-based solvents such as acetate; ketone-based solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; dimethylformamide and the like can be used. The type of solvent used is not limited to these. These solvents may be used alone, or two or more kinds may be used as a mixed solvent, and the amount of the solvent used may be determined in consideration of the monomer concentration, the desired molecular weight of the polymer, the polymer solution concentration, etc. It may be set appropriately.

When polymerizing the monomer mixture (I) or (II), a polymerization initiator is usually used. Examples of the polymerization initiator include 2,2′-azobis- (2-methylbutyronitrile) and tert-butylperoxy-
2-ethylhexanoate, 2,2'-azobisisobutyronitrile, benzoyl peroxide, di-ter
A known radical polymerization initiator such as t-butyl peroxide can be used. The amount of the polymerization initiator to be used should be appropriately determined according to the required properties of the polymer and is not particularly limited, but 0.01% by mass or more, 50% by mass or more with respect to the total amount of the monomer mixture (I) or (II). The content is preferably not more than mass%, more preferably not less than 0.05 mass% and not more than 20 mass%.

If necessary, for example, n-dodecyl mercaptan, n-butyl mercaptan, 3-mercaptopropylmethyldimethoxysilane, (CH ₃ O) ₃ Si
The molecular weight of the polymer may be adjusted by adding one or more chain transfer agents such as —S—S—Si (OCH ₃ ) ₃ .

The temperature of the polymerization reaction is not particularly limited, but it is preferably in the range of room temperature to 200 ° C, more preferably 40 to 140 ° C. The reaction time may be appropriately set depending on the composition of the monomer component used, the type of the polymerization initiator, etc. so that the polymerization reaction can be completed efficiently.

The molecular weight of the polymer is not particularly limited, either,
Weight average molecular weight (Mw) of 2,000 to 500,000
Is preferable, and more preferably 4,000 to 250,000.
The range is 0. The weight average molecular weight here means GP
It means a value obtained by using C as a standard polystyrene.

The first type resin composition contains a polymer obtained from the monomer component (I), but from the viewpoint of workability at the time of coating, the polymer is dissolved in a solvent. It is preferably in a solution state. As the solvent, any of the solvents exemplified in the solution polymerization can be used. When the polymer is synthesized by a method other than solution polymerization, the polymer may be separated after the polymerization and dissolved in a solvent.

To obtain the second type of resin composition, the polymer obtained from the monomer component (II) and the additive type ultraviolet absorber may be mixed. Examples of the addition type ultraviolet absorber include commercially available products "Tinuvin 234" and "Tinuvin 32".
9 "(all manufactured by Ciba Specialty Chemicals)," ADEKA STAB LA-36 "," ADEKA STAB L "
A-31 "(all manufactured by Asahi Denka Co., Ltd.) and the like. These ultraviolet absorbers have an ultraviolet absorbing group such as benzotriazole and have the ability to absorb ultraviolet rays, but their ultraviolet absorbing ability is gradually lost due to the decomposition of the ultraviolet absorbing group. However, in the present invention, the polymer using the monomer (B) and / or (C) suppresses the decomposition of the ultraviolet absorbing group, so that the ultraviolet absorbing ability is exerted for a very long period of time. The preferred blending amount of the ultraviolet absorber is 0.1 to 30 parts by mass with respect to 100 parts by mass of the polymer (nonvolatile content). If the amount is less than 0.1 parts by mass, the ultraviolet ray blocking ability may be insufficient,
Excessive addition in excess of parts by mass is liable to cause bleed-out, which is not preferable. An inorganic ultraviolet absorber such as zinc oxide can also be used.

The resin composition of the present invention (first in the description below
And the second type resin composition is simply represented by a resin composition), and various additives may be contained therein. Hereinafter, compounds that can be suitably used as additives will be described.

Silane Coupling Agent In particular, when the base material of the solar cell is glass, the addition of the silane coupling agent improves the adhesion between the ultraviolet shielding layer and the glass base material. A suitable silane coupling agent is "A-186" manufactured by Nippon Unicar Co., Ltd.
And epoxy-containing silane coupling agents such as "A-187" and "SH6040" manufactured by Toray Dow Corning Silicone; "A-1120" manufactured by Nippon Unicar Co., Ltd., and "A-1120" manufactured by Toray Dow Corning Silicone. SH602
0 "," SH6020F "," SZ6023 "and other amino group-containing silane coupling agents;" A-1310 "," Y-5187 "," Y-991 "manufactured by Nippon Unicar Co., Ltd.
0 "," A-11597 "and the like. These may be used in the range of 0.5 to 30 parts by mass with respect to 100 parts by mass of the polymer (nonvolatile content).

Curing agent When a polymer is obtained from the monomer mixture (I) or (II) containing the above-mentioned crosslinkable monomer (D-2), a functional group capable of reacting with the functional group of the monomer (D-2). It is preferable to add a curing agent (crosslinking agent) having a group to the resin composition to cause a crosslinking reaction when forming a coating film, whereby various properties of the ultraviolet shielding layer are improved. Monomer (D-2)
Various known curing agents can be used depending on the functional group of.
The amount of these curing agents used is not particularly limited and may be appropriately increased or decreased depending on the amount of the monomer (D-2) used.

When the functional group of the monomer (D-2) is a hydroxyl group, a polyisocyanate compound having two or more isocyanate groups or a modified product thereof or an aminoplast resin is preferable as a curing agent.

Specific examples of the polyisocyanate compound include tolylene diisocyanate (TDI), 4,4'-
Known diisocyanate compounds such as diphenylmethane diisocyanate (MDI); buret polyisocyanate compounds such as "Sumijour N" (manufactured by Sumitomo Bayer Urethane Co.); "Desmodur IL" and "Desmodur HL" (all are Bayer AG. Polyisocyanate compound having an isocyanurate ring known as "Coronate EH" (manufactured by Nippon Polyurethane Industry Co., Ltd.); "Sumijour L" (manufactured by Sumitomo Bayer Urethane Co.); adduct polyisocyanate compound; "Coronate L" And “Coronate L-55E” (both manufactured by Nippon Polyurethane Co., Ltd.) and the like. These may be used alone or in combination of two or more. Also,
It is also possible to use so-called blocked isocyanates which are inactivated by reacting the isocyanate group of these compounds with a masking agent having active hydrogen.

As the aminoplast resin, methyl etherified melamine resin, butyl etherified melamine resin,
Examples thereof include butyl etherified benzoguanamine-based resin, butyl etherified cyclohexyl benzoguanamine-based resin and the like, and water-solubilized products thereof.

UV Stabilizer When a polymer is synthesized without using the above-mentioned monomer (C) having a UV stable group, an addition type UV stabilizer can be used. Preferred as an addition type ultraviolet stabilizer is a sterically hindered piperidine compound, and examples of commercially available products include “Tinuvin 123” and “Tinuvin 14”.
4 "," Tinuvin 765 "(all manufactured by Ciba Specialty Chemicals)," Adeka Stab LA-52 ",
"ADEKA STAB LA-57", "ADEKA STAB LA-6
2 "," ADEKA STAB LA-77 "(all manufactured by Asahi Denka Kogyo Co., Ltd.) and the like. Further, since these relatively low molecular weight UV stabilizers may bleed out, a polymer type UV stabilizer is separately synthesized from the above-mentioned monomer (C) having an UV stable group and added. May be. The preferred blending amount of the ultraviolet stabilizer is 0.1 to 15 parts by mass with respect to 100 parts by mass of the polymer (nonvolatile content). If the amount is less than 0.1 parts by mass, the effect of addition is not exhibited, and the effect of suppressing the photodegradation of the ultraviolet absorbing group becomes insufficient particularly when the monomer (C) is not used, and the ultraviolet shielding ability cannot be maintained for a long period of time. However, if it is added excessively in an amount exceeding 15 parts by mass, bleeding out tends to occur, or the water resistance is lowered, which is not preferable.

Other Resins In the resin composition, other resins may partially coexist as long as the object of the present invention is not impaired. For example,
Thermosetting resins that can be crosslinked and cured by the action of the thermoplastic resin or the resin itself or a curing agent (crosslinking agent) can be used.
The types and amounts of these other resins may be appropriately determined according to the application of the ultraviolet-shielding resin laminate and required characteristics.
Specific examples of other resins include thermoplastic resins such as vinyl chloride resin, polyester resin, acrylic resin, and silicone resin; urethane resin, aminoplast resin, silicone resin, epoxy resin, acrylic resin. Independent curing type heat / ultraviolet / electron beam curable resin such as resin;
A thermosetting resin that is cured with a curing agent such as polyester resin, acrylic resin, or epoxy resin can be used.

Other Additives Leveling agents, antioxidants, fillers such as talc, rust preventives, fluorescent brightening agents, antioxidants, antistatic agents generally used in layer forming compositions such as paints. , Pigments, dyes, thickeners,
Inorganic particles such as colloidal silica and alumina sol, and polymethylmethacrylate-based acrylic particles may be added. Further, JP-A-7-178335 and JP-A-7-178335
It is also possible to add composite inorganic fine particles in which an organic polymer is fixed to the surface of the inorganic fine particles as described in JP-A-302257. Further, when the polymer is synthesized using the reactive silyl group-containing monomer, a known curing catalyst that accelerates hydrolysis condensation may be added.

The resin composition of the present invention is used to form an ultraviolet shielding layer on the light incident surface side of a dye-sensitized solar cell. The structure of the dye-sensitized solar cell is not particularly limited. A general dye-sensitized solar cell has a first base material, a first conductive film, a metal oxide semiconductor electrode (photoelectrode) in which a dye is adsorbed, a charge transfer layer (redox) in order from the light incident surface. A pair of electrolytes), a counter electrode, a second conductive film, and a second base material. In the case of a solar cell configured so that light is incident from both the first base material side and the second base material side, the ultraviolet shielding layers are formed on both sides.

As the first base material and the second base material, glass and plastic films having excellent transparency are preferable. As materials for the plastic film, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN)
Polyester film such as; polyvinyl halide, polyvinylidene chloride, vinyl fluoride, etc. polyvinyl halide film; polyethylene, polypropylene, etc. polyolefin film; triacetyl cellulose, etc. cellulose ester film; (meth) acrylate Film: Poly (ethylene-tetrafluoroethylene)
(ETEF), polytetrafluoroethylene (PTF
E), polychlorotrifluoroethylene (PCTF
E), polyvinylidene fluoride (PVDF), and fluororesin films such as poly (tetrafluoroethylene-hexafluoropropylene) (FEP). The first base material and the second base material may be the same or different.

The first conductive film and the second conductive film are usually formed by a known method such as vapor deposition or sputtering.
Al, Cu, Rh, Ag, In, Pt, A on the substrate surface
Metal thin film such as u, ITO (In-Sn composite oxide), F
TO (obtained by forming a thin film of a conductive metal oxide such as tin oxide doped with fluorine, or a carbon thin film). In the case of a solar cell that receives sunlight only from the first conductive film, the first conductive film is used. A structure in which the film is a highly transparent film and the second conductive film is a low transparent film may be adopted.

As the metal oxide semiconductor electrode in the state where the dye is adsorbed, any of known semiconductor electrodes used in ordinary dye-sensitized solar cells can be adopted. It is preferable that the pores adsorb the dye.

As the semiconductor used for the semiconductor electrode, Ti, V, Fe, Zn, Sr, Y, Zr, Nb and I are used.
Oxides of n, Sn, La, Ce, Hf, Ta, or W are mentioned as preferable ones, and TiO ₂ , Fe _{2 are} particularly preferable.
O ₃ , ZnO, Nb ₂ O ₅ and WO ₃ are preferred. Further, it is not limited to a metal oxide, but a single semiconductor such as Si or Ge, III-
V-based compound semiconductors, metal chalcogenides other than oxides (metal sulfides, selenides, tellurides, etc.), compounds having a perovskite structure, and the like can also be used.

The method for forming the semiconductor layer is not particularly limited, but in the case of a metal oxide semiconductor electrode, a dispersion of fine particles of a metal oxide is spin-coated on the first base material in order to make it porous. It is preferable to adopt a method of applying heat treatment (baking) after coating or spraying. As the dispersion liquid of the metal oxide fine particles, a known method such as a sol-gel method or a method in which the metal oxide is mechanically made into fine particles and dispersed in a dispersion medium can be adopted. Water, alcohol,
Various organic solvents such as toluene and mixed solvents thereof may be used.

After forming the semiconductor layer, the dye is adsorbed. In order to adsorb the dye, the dye may be dissolved in the organic solvent to prepare a dye solution, and the semiconductor layer may be dipped or sprayed / coated on the semiconductor layer. As the dye, any conventionally known dye having a property of absorbing light in the visible light region and the infrared light region can be adopted, a typical ruthenium bipyridine dye (ruthenium complex) is most preferable, and other cyanine dyes A styryl dye, a porphyrin dye, etc. can also be used.

Charge Transfer Layer (Electrolyte Having Redox Pair)
As the electrolyte, an electrolytic solution can be usually used, but a so-called gel electrolyte in which a polymer matrix is impregnated with the electrolytic solution, or a molten salt having a redox couple can also be used.
The electrolytic solution is composed of an electrolyte, a solvent, and an additive added as necessary. The electrolytic solution can be used by injecting it into a predetermined position as it is, or by filling it in a porous support having through holes.

The electrolyte of the electrolytic solution is a combination of an oxidant and a reductant (a redox _couple ), and iodine (I ₂ )
And a metal iodide or an iodide such as a quaternary ammonium compound iodide salt, or a combination of bromine (Br ₂ ) with a bromide such as a metal bromide or a quaternary ammonium compound bromine salt. .

As the solvent of the electrolytic solution, any solvent can be used as long as it can dissolve the electrolyte, has a low viscosity and has ion conductivity, and ethers, alcohols, carbonates, ester compounds, nitrile compounds and the like can be used.

Any known counter electrode can be used as the counter electrode, and the counter electrode is not particularly limited. However, since the energy exchange efficiency is enhanced, it is common to use Pt fine particles layered by a vapor deposition method, a sputtering method, or the like. .

The ultraviolet shielding layer of the present invention is directly or, if necessary, via another layer such as an adhesion improving layer (primer layer or the like) provided on the surface of the first substrate located on the light incident surface side of the solar cell. Can be formed. In addition, if the solar cell has a structure capable of receiving light from both the first base material side and the second base material side,
It is necessary to provide an ultraviolet shielding layer on both sides.

The polymer (modified polymer) obtained from the monomer mixture (I) or (II) is also contained in 100% by mass of the dry coating film (ultraviolet shielding layer) obtained from the resin composition.
The same shall apply hereinafter) and the addition-type ultraviolet absorber (in the case of the second type) are 50 mass% or more, preferably 80 mass% or more, and more preferably 90 mass% or more. It is desirable to regulate the amount. If it is less than 50% by mass, the weather resistance of the coating film having an ultraviolet shielding ability may be insufficient.

As the method for applying the resin composition to the substrate, known coating methods such as dipping, spraying, brush coating, curtain flow coating, gravure coating, roll coating, spin coating, bar coating and electrostatic coating can be used. Either can be adopted.

The thickness of the ultraviolet shielding layer is Lambert-
According to Beer's law, the amount of UV-absorbing groups present in the layer, and when using the resin composition of the first type, the amount of the UV-absorbing group-containing monomer (A) in the monomer mixture (I). When the second type resin composition is used, it depends on the amount of the additive type ultraviolet absorber used. Therefore, the layer thickness may be determined in consideration of the amount of the ultraviolet absorbing group contained in the resin composition and the weather resistance required for the ultraviolet shielding layer of the dye-sensitized solar cell. Usually 0.5-1
It is within the range of 00 μm. If the thickness exceeds 100 μm, the ultraviolet absorption performance is saturated, which is wasteful in terms of cost.
On the other hand, if the thickness is less than 0.5 μm, it is difficult to apply it uniformly on the substrate, and the ultraviolet shielding ability may be insufficient. A more preferable thickness range is 1 to 50 μm, and further preferable is 2 to 30 μm.

On the outermost surface of the ultraviolet shielding layer, a photocatalytic functional layer for improving stain resistance, an antifogging layer, a heat ray shielding layer, etc. may be formed. When forming a hard coat layer of a silicone-based or acrylic-based curable resin for improving scratch resistance, a reactive silyl group-containing monomer (E) is used as a polymer for forming the ultraviolet shielding layer. Preference is given to using the polymers mentioned.

[0106]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these, and may be appropriately modified within a range compatible with the gist of the preceding and the following. It is also possible to carry out, and all of them are included in the technical scope of the present invention. In the following Examples and Comparative Examples, “part” and “%” represent parts by mass or% by mass.

Synthesis Example 1 (Synthesis of Polymer for Resin Composition of Second Type) 100 parts of butyl acetate was charged into a flask equipped with a stirrer, a dropping port, a thermometer, a cooling pipe and a nitrogen gas inlet.
Separately, a monomer solution mixture was prepared by dissolving 70 parts of tert-butyl methacrylate, 30 parts of methyl methacrylate, 10 parts of butyl acetate and 0.6 parts of 2,2′-azobis (2-methylbutyronitrile) as an initiator. Put 30% of that in a flask,
The temperature was raised to 85 ° C. while introducing nitrogen gas and stirring. The remaining 70% monomer solution mixture was added dropwise over 2 hours,
After the dropping, heating was continued for 3 hours. 95 ° C 5 hours after dropping
The temperature was raised to 2, the heating was continued for 2 hours, and then cooled.

When diluted with 40 parts of butyl acetate, polymer solution No. 4 having a nonvolatile content of 40.1% was obtained. Got 1.
The weight average molecular weight (Mw) of this polymer was 49200. In each synthesis example, the nonvolatile content is a value measured by weighing 1 g of the polymer solution and heating and drying at 200 ° C. for 15 minutes, and the weight average molecular weight is a value obtained by using GPC with reference to standard polystyrene. is there.

Synthetic Examples 2, 8 and 9 Regarding Synthetic Examples 2, 8 and 9 shown in Table 1, polymer solution No. 1 was prepared in the same manner as in Synthetic Example 1 except that the monomer composition was changed as shown in Table 1. 2, 8 and 9 were obtained. No. Two
Is a polymer solution for a second type of resin composition.

Synthesis Example 3 (Synthesis of Polymer for Resin Composition of First Type) In a flask equipped with a stirrer, a dropping port, a thermometer, a cooling pipe and a nitrogen gas inlet, 25 parts of ethyl acetate and 2- [2] '-
Hydroxy-5 ′-(methacryloyloxyethyl) phenyl] -2H-benzotriazole (manufactured by Otsuka Chemical Co., Ltd.,
Product name "RUVA93"; referred to as UVA. ) 10 parts were prepared. Separately, cyclohexyl methacrylate 30
Parts, 2-ethylhexyl acrylate 10 parts, UVA
10 parts, 2-hydroxyethyl methacrylate 15 parts,
A monomer solution mixture in which 25 parts of methyl methacrylate, 75 parts of ethyl acetate and 6 parts of 2,2′-azobis (2-methylbutyronitrile) were dissolved was prepared, and 30% of the mixture was charged into a flask, and nitrogen gas was added. Was introduced and the temperature was raised to the reflux temperature while stirring. The remaining 70% monomer solution mixture was added dropwise over 2 hours, and after the addition, heating was continued for 6 hours, and then the mixture was cooled. When diluted with 50 parts of ethyl acetate, a polymer solution having a nonvolatile concentration of 40% was obtained. The weight average molecular weight of this polymer is 2130.
It was 0.

Synthesis Examples 4 to 7 Polymer solutions Nos. 4 to 7 shown in Table 1 were prepared in the same manner as in Synthesis Example 3 except that the monomer composition was changed as shown in Table 1. 4-7 were obtained. These are all polymer solutions for resin compositions of the first type.

[0112]

[Table 1]

The abbreviations in Table 1 have the following meanings. Ultraviolet absorbing monomer (A): Monomer (A) having ultraviolet absorbing group UVA: 2- [2'-hydroxy-5 '-(methacryloyloxyethyl) phenyl] -2H-benzotriazole (manufactured by Otsuka Chemical Co., Ltd .; product Name "RUVA93") UVA: 2-hydroxy-4- (2-acryloyloxyethoxy) benzophenone (Osaka Organic Chemical Industry Co., Ltd .; trade name "BP-1A") UVA: 2,4-diphenyl-6- [2- Hydroxy-4- (2-acryloyloxyethoxy) -s-triazine monomer (B): Monomer having alkyl group having 4 or more carbon atoms (B) TBMA: tert-butyl methacrylate CHMA: cyclohexyl methacrylate 2EHA: 2-ethylhexyl acrylate UV Stable monomer (C): a model having an ultraviolet stable group. Mar (C) HALS: "Adeka Stab LA82" (trade name; manufactured by Asahi Denka Co., Ltd.) (meth) acrylate (D-1): (meth) acrylate (D-1) MMA having an alkyl group having 3 or less carbon atoms: Methyl methacrylate crosslinkable monomer (D-2): Monomer having crosslinkable functional group (D-2) HEMA: 2-Hydroxyethylmethacrylate silyl group-containing monomer (E-1): Reactive silyl group at terminal is carbon atom Directly connected monomer (E-1) "KBM503": (trade name; manufactured by Shin-Etsu Chemical Co., Ltd.)

Experimental Example 1 Polymer solution No. 1 obtained in Synthesis Example 1 In 100 parts of 1, an addition type ultraviolet absorber (trade name "ADEKA STAB LA3
1 ”; manufactured by Asahi Denka Co., Ltd .; abbreviated as LA31. 2 parts and 2 parts of a silane coupling agent (trade name "A186"; manufactured by Nippon Unicar Co., Ltd.) were mixed and diluted with toluene to an appropriate viscosity.
The obtained resin composition was applied to one surface of a quartz glass plate having a thickness of 2 mm by a bar coater so that the dry film thickness was 20 μm, and dried at 100 ° C. for 30 minutes. A glass laminate having an ultraviolet shielding layer formed on one surface of a quartz glass plate was obtained.

Experimental Example 2 Polyisocyanate as a curing agent (trade name "Sumijour N3200"; manufactured by Sumitomo Bayer Urethane Co .; N320)
Abbreviated as 0. ) Was added in the same manner as in Experimental Example 1 to prepare a glass laminate.

Experimental Examples 3 to 4, 6 to 8 To 100 parts of each polymer solution, 9 parts of the curing agent "N3200" was added.
Part of the mixture was added and diluted with toluene to an appropriate viscosity. The obtained resin composition was applied to a polyethylene terephthalate film having a thickness of 100 μm (trade name “COSMOSHINE A410
0 ”; manufactured by Toyobo Co., Ltd .; PET) is coated on one surface with a bar coater so that the dry film thickness is 5 μm, and then at 80 ° C. for 12 hours.
It was dried for 0 minutes. A PET laminate having an ultraviolet shielding layer formed on one side of a PET film was obtained.

Experimental Example 5 Except that 4 parts of γ- (2-aminoethyl) aminopropylmethyldimethoxysilane; trade name "SZ6023"; manufactured by Toray Dow Corning Silicone Co., Ltd.) were added instead of the curing agent "N3200". PE as in Experimental Example 3
A T laminate was obtained.

Experimental Example 9 Polymer solution No. 1 obtained in Synthesis Example 9 A glass laminate was obtained in the same manner as in Experimental Example 1 except that 9 was used.

The laminates obtained in the above experimental examples were evaluated by the following evaluation methods, and the results are shown in Table 2.

[UV shielding ability retention rate] A spectrophotometer (“UV-3100”) manufactured by Shimadzu Corporation was used as a blank, and a base material (glass,
After measuring the ultraviolet transmittance of PET),
The UV transmittance at 60 nm was measured, and 100-UV transmittance (%) was taken as the initial UV cut rate.

In addition, each laminate test piece was replaced with a fixed metal halide lamp type accelerated weathering tester, a super energy irradiation tester "UE-IDEC type" manufactured by Suga Test Instruments Co., Ltd. (quartz as an inner filter, and as an outer filter). # 275) was used so that the ultraviolet ray incident side would serve as the ultraviolet ray shielding layer. [70 ° C, 70% RH environment,
Irradiation of 100 mW / cm ² ultraviolet light for 6 hours] → [80
Irradiation for 6 hours in the environment of 90 ° C. and 90% RH] was set as one cycle, and 30 cycles were repeated.

360 nm after accelerated test with the above spectrophotometer
When the ultraviolet ray transmittance in the is measured and the initial UV cut rate is X and the UV cut rate after 30 cycles is Y,
The value obtained by [(X−Y) / X] × 100 (%) was defined as the UV shielding ability retention rate (%).

[Haze] Color difference meter on the spectral side (“SZ-Σ9
0 "; manufactured by Nippon Denshoku Industries Co., Ltd.). As a blank, a substrate (glass,
After measuring the haze of PET), the haze before the accelerated test and the haze after 30 cycles of the accelerated test were measured.

[Maintenance of energy conversion efficiency] A dye-sensitized solar cell was prepared by the following procedure.

As the first base material and the first conductive film, an FTO substrate (glass with FTO thin film: product number “VZ019”; made by Nippon Sheet Glass) was used, and titania sol (Ishihara Sangyo Co., Ltd., STS) was used.
-21) was spin-coated, dried by heating at 100 ° C. for 5 minutes, and then heat-treated at 450 ° C. for 1 hour to form a porous titanium oxide thin film photoelectrode having a film thickness of 2 μm on the first conductive film side. Next, a RuN3 dye (Ruthen having a concentration of 3.0 × 10 ⁻⁴ M)
ium 535, manufactured by SOLARONIX) was immersed in an ethanol solution for 10 hours to adsorb the RuN3 dye onto the porous titanium oxide thin film photoelectrode. A part composed of the first substrate, the first conductive film, and the photoelectrode on which the dye was adsorbed was obtained.

Each of the laminates obtained in the above experimental example (initial or accelerated weathering test after 30 cycles) was used as the first part of the above parts.
On the base material (glass surface side), the ultraviolet shielding layer is placed on the light incident side, and 365n for the dye decomposition acceleration test.
m ultraviolet light (HB-25103BY-C, manufactured by Ushio, light intensity; 34 mW / cm ² ) was irradiated for 30 minutes.

Separately, another FTO substrate was used as the second base material (manufacturing step 2) and the second conductive film, and Pt was subjected to 10 minutes × 3 times with a Hitachi sputtering device “E-1010”. Sputtering, counter electrode (platinum electrode) + second
A part including a conductive film and a second base material was produced.

The above parts were superposed on each other with an insulating spacer of beads interposed therebetween with a spacing of about 10 μm.
Acetonitrile as a solvent, 0.1 mol / l lithium iodide, 0.05 mol / l iodine, 0.3 mol
/ L of 1,2-dimethyl-3-propylimidazole iodine salt and 0.5 mol / l of tert-butylpyridine were injected and then sealed with an epoxy adhesive to form a dye-sensitized solar cell. It was made.

Subsequently, the first base material (FTO substrate) and the counter electrode (platinum electrode) (photoelectric conversion area: 0.196 cm ² , φ)
5.0mm) and connect alligator clips to 50
The light of a 0 W xenon lamp (manufactured by USHIO) is used as simulated sunlight and a spectral filter (manufactured by Oriel, AM1.
Through 5), irradiation was carried out from the ultraviolet shielding layer side. The light intensity I at this time was 100 mW / cm ² .

The generated electricity is used as a current / voltage measuring device in an ammeter (“487”; manufactured by KEITHLEY), a function generator (“HB-105”; manufactured by Hokuto Denko), and a potentiostat (HA-5016 “Hokuto Denko”). Manufactured ”). The open-circuit photovoltage Voc (V) and the short-circuit photocurrent density Jsc (mA / c) obtained from the above
m ² ), fill factor FF, and light intensity I: 100 m
From W / cm ² , the energy conversion efficiency η
(%) Was calculated.

Η = 100 × Voc × Jsc × FF / I Here, the case where the parts using the laminate before the accelerated test 30 cycles is used is the initial energy conversion efficiency η ₀ , and the accelerated test is 30 cycles. The energy conversion efficiency maintenance rate (%) is defined as 100 × (η ₁ / η ₀ ) where the energy conversion efficiency η ₁ after the accelerated test is the case where the parts using the laminated body are used. It was evaluated whether or not the decomposition of the pigment could be suppressed.

[0132]

[Table 2]

As is clear from Table 2, when the second type UV-shielding layer using the additive type UV-absorbing agent is formed (Experimental Examples 1 and 2), the UV-absorbing monomer (A) is not used. Polymerized first type (Experimental Examples 3 to 7)
Compared with the above, the UV shielding ability retention rate, the coating film appearance after 30 cycles of the accelerated weather resistance test, and the energy conversion efficiency maintenance rate remained at a slightly lower level, and the examples of the present invention exhibited excellent performance as a whole, It was confirmed that the UV shielding ability was maintained throughout.

In Experimental Example 8 in which the ultraviolet absorbing monomer (A) was used but neither of the monomers (B) and (C) was used, each performance after the accelerated weather resistance test was extremely lowered. From this, it was confirmed that the photo-decomposition of the ultraviolet absorbing group was occurring. In addition, in Experimental Example 9 in which the addition type ultraviolet absorber was used but neither of the monomers (B) and (C) was used, “clouding” was caused by the accelerated weather resistance test, and therefore, the UV shielding ability was maintained. The rate itself is 10
Although it was 0%, the measurement of energy conversion efficiency as a solar cell was stopped because the haze was significantly reduced.

[0135]

EFFECTS OF THE INVENTION The dye-sensitized solar cell of the present invention has the UV-shielding layer having a specific structure formed on the incident light side of the dye-sensitized solar cell, so that the UV-shielding layer is protected from UV rays even when exposed to sunlight for a long time. The performance could be maintained at a high level, and the energy conversion efficiency of the solar cell could be kept high. Therefore, it was possible to provide a dye-sensitized solar cell having excellent durability.

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Claims (6)

[Claims] 1. A dye-sensitized solar cell having an ultraviolet light shielding layer formed on the light incident surface side, wherein the ultraviolet light shielding layer has a monomer having an ultraviolet absorbing group and an alkyl group having 4 or more carbon atoms. Monomer mixture (I) containing a monomer and / or a monomer having an ultraviolet stable group
A dye-sensitized solar cell, which is formed from a resin composition for forming an ultraviolet shielding layer containing a polymer synthesized from. 2. A dye-sensitized solar cell in which an ultraviolet shielding layer is formed on the light incident surface side, wherein the ultraviolet shielding layer contains a monomer having an alkyl group having 4 or more carbon atoms and / or an ultraviolet stable group. A dye-sensitized solar cell, which is formed from a resin composition for forming an ultraviolet-shielding layer, which contains a polymer synthesized from a monomer mixture (II) containing a monomer having the above and an additive-type ultraviolet absorber. 3. The dye-sensitized solar cell according to claim 1, wherein the monomer mixture (I) or (II) further contains a monomer having a crosslinkable functional group. 4. The dye-sensitized solar cell according to claim 1, wherein the ultraviolet shielding layer is directly formed on the glass substrate of the dye-sensitized solar cell. 5. The dye-sensitized solar cell according to claim 4, wherein the resin composition for forming an ultraviolet shielding layer further contains a silane coupling agent. 6. The dye-sensitized solar cell according to claim 1, wherein the ultraviolet shielding layer is formed directly or indirectly on the plastic substrate of the dye-sensitized solar cell.