JP5261034B2 - Dye-sensitized solar cell encapsulant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealant used as a sealant for preventing an electrolytic solution between substrates of a transparent conductive electrode and a counter electrode in a dye-sensitized solar cell from being leaked out around edges of the substrates and moisture from entering from around the edges of the substrates between the substrates, which has excellent long-term reliability even in the case where the electrolytic solution is a polar low-boiling organic solvent such as acetonitrile. <P>SOLUTION: A sealant for dye-sensitized solar cell is made by forming a rubber composition in cross-linkage, the composition containing: ethylene-&alpha;-olefin-unconjugated polyene copolymers [A] satisfying a certain requirement; certain SiH-group-containing compounds [B] having two SiH groups in one molecule; and certain SiH-group-containing compounds [C] having three SiH groups in one molecule. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a dye-sensitized solar cell sealing material. More specifically, the present invention relates to a dye-sensitized solar cell encapsulant comprising a rubber composition comprising an ethylene / α-olefin / non-conjugated polyene copolymer and a SiH group-containing compound.

  The dye-sensitized solar cell announced by Gretzell et al. In 1991 is a wet solar cell using a light conversion layer sensitized with a spectral sensitizing dye as a working electrode. The basic components include a transparent conductive electrode provided on a transparent substrate such as glass, an electrolyte solution, a spectral sensitizing dye, a porous semiconductor layer such as titanium oxide, and a counter electrode provided on the substrate.

  Dye-sensitized solar cells are expected to be low-cost solar cells because the materials used are inexpensive and do not require large-scale equipment such as a vacuum process for production. However, the long-term reliability of current dye-sensitized solar cells is considered to be lower than that of silicon-based ones. One of the causes is a problem of sealing of an electrolytic solution that is an electron carrier. If the electrolytic solution leaks or water enters the electrolytic solution, not only the power generation efficiency is lowered, but also the light conversion layer may be deteriorated. Therefore, in order to improve the long-term reliability of the dye-sensitized solar cell, the leakage of the electrolyte solution between the transparent conductive electrode and the counter electrode to the periphery of the substrate end or from the periphery of the substrate end to the substrate It is indispensable to prevent the intrusion of moisture by using a sealing material.

  For the electrolytic solution, forms such as liquid, gel, and solid are used. A gel or solid with little leakage is suitable for sealing the electrolytic solution (Patent Document 1). However, in order to obtain a conversion efficiency as high as that of the silicon system, a liquid, or an organic solvent having high polarity and high volatility such as acetonitrile is preferable. However, it is extremely difficult to seal such an electrolyte solution in a solar battery cell without leakage over a long period of time.

As a sealing method, an adhesive method such as a liquid adhesive, a hot melt film, or a glass frit has been applied so far.
On the other hand, there has been proposed a non-adhesive method in which an electrolyte is sealed by using a synthetic resin having elasticity as a sealing material, disposing it around the edge of the substrate, and sandwiching and compressing it between the substrates. As the synthetic resin having elasticity suitable for this, liquid rubber capable of LIM molding is preferable.

On the other hand, silicone rubber (Patent Document 1) and butyl rubber (Patent Document 2) have been proposed as synthetic resins having elasticity suitable for sealing dye-sensitized solar cells. Although butyl rubber is excellent in permeation resistance and moisture resistance of the electrolyte, it is inferior in compression set resistance. Silicone rubber is excellent in moldability by LIM, but inferior in permeation resistance and moisture resistance of the electrolyte. Furthermore, liquid fluororubber is known as a rubber having excellent LIM moldability, but it has a property of easily swelling with respect to an electrolyte such as acetonitrile.
JP 2007-214075 A JP 2004-95248 A

The present invention provides a seal that prevents leakage of the electrolyte solution between the transparent conductive electrode and the counter electrode of the dye-sensitized solar cell to the periphery of the substrate end and the penetration of moisture from the periphery of the substrate end to the substrate. An object of the present invention is to provide a sealing material having excellent long-term reliability even when the electrolytic solution is a polar low-boiling organic solvent such as acetonitrile when used as a stopper.

  As a result of intensive studies to solve the above problems, the present inventors have found that the rubber composition used in the present invention can form a sealing material having excellent long-term durability against polar low boiling point organic solvents such as acetonitrile. As a result, the present invention has been completed.

That is, the encapsulant for dye-sensitized solar cell of the present invention includes an ethylene / α-olefin / non-conjugated polyene copolymer [A] satisfying the following (a) to (e) and the following general formula [II]: And an SiH group-containing compound [B] having two SiH groups in one molecule, and the following general formula [III]
A rubber composition containing a SiH group-containing compound [C] having three SiH groups in one molecule is crosslinked and molded.

(A) a copolymer of ethylene, α-olefin and non-conjugated polyene,
(B) the α-olefin has 3 to 20 carbon atoms,
(C) The weight ratio of ethylene unit / α-olefin unit is 35/65 to 95/5,
(D) the iodine value is in the range of 0.5-50,
(E) The intrinsic viscosity [η] measured in a decalin solution at 135 ° C. is 0.01 to 5.0 dL / g.

（式［II］中、Ｒ³は、それぞれ独立に、炭素原子数１〜１０の１価の基で、非置換また
は置換の飽和炭化水素基もしくは芳香族炭化水素基を表し、ａは、０〜２０の整数を表し、ｂは、０〜２０の整数を表し、Ｒ⁴は、炭素原子数１〜３０の２価の有機基または酸素
原子である。）

(In the formula [II], each R ³ independently represents a monovalent group having 1 to 10 carbon atoms and represents an unsubstituted or substituted saturated hydrocarbon group or aromatic hydrocarbon group, and a is 0. Represents an integer of ˜20, b represents an integer of 0 to 20, and R ⁴ represents a divalent organic group having 1 to 30 carbon atoms or an oxygen atom.)

（式［III］中、Ｒ⁵は、それぞれ独立に、炭素原子数１〜１０の１価の基であって、非置換または置換の飽和炭化水素基もしくは芳香族炭化水素基を表し、ａ、ｂおよびｃは、それぞれ独立に、０〜２０の整数を表し、Ｒ⁶は、炭素原子数１〜３０の３価の有機基を表
す。）
上記エチレン・α−オレフィン・非共役ポリエン共重合体［Ａ］製造用の非共役ポリエンは、さらに下記（ｆ）を満足することが好ましい。

(In the formula [III], each R ⁵ independently represents a monovalent group having 1 to 10 carbon atoms, and represents an unsubstituted or substituted saturated hydrocarbon group or aromatic hydrocarbon group, a, b and c each independently represents an integer of 0 to 20, and R ⁶ represents a trivalent organic group having 1 to 30 carbon atoms.)
The non-conjugated polyene for producing the ethylene / α-olefin / non-conjugated polyene copolymer [A] preferably further satisfies the following (f).

  (F) The non-conjugated polyene is at least one norbornene compound represented by the following general formula [I].

（式［Ｉ］中、ｎは、０〜１０の整数を表し、Ｒ¹は、水素原子または炭素原子数１〜１
０のアルキル基を表し、Ｒ²は、水素原子または炭素原子数１〜５のアルキル基を表す。
）
上記エチレン・α−オレフィン・非共役ポリエン共重合体［Ａ］１００重量部に対して、１分子中にＳｉＨ基を３個有するＳｉＨ基含有化合物［Ｃ］を０．１〜２重量部含有することが好ましい。

(In the formula [I], n represents an integer of 0 to 10, and R ¹ represents a hydrogen atom or a carbon atom number of 1 to 1.
0 represents an alkyl group, and R ² represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.
)
0.1-2 parts by weight of SiH group-containing compound [C] having three SiH groups in one molecule is contained per 100 parts by weight of the ethylene / α-olefin / non-conjugated polyene copolymer [A]. It is preferable.

The SiH group-containing compound [C] having three SiH groups in one molecule is represented by the following formula [III-1
The compound represented by this may be sufficient.

上記エチレン・α−オレフィン・非共役ポリエン共重合体［Ａ］１００重量部に対して、１分子中にＳｉＨ基を２個有するＳｉＨ基含有化合物［Ｂ］を２〜１５重量部含有することが好ましい。

2 to 15 parts by weight of the SiH group-containing compound [B] having two SiH groups in one molecule per 100 parts by weight of the ethylene / α-olefin / non-conjugated polyene copolymer [A] preferable.

  The SiH group-containing compound [B] may be a compound represented by the following formula [II-1].

本発明の色素増感型太陽電池用封止材は、上記ゴム組成物からなるＬＩＭ成形用ガスケット材であることが好ましい。

It is preferable that the sealing material for dye-sensitized solar cells of the present invention is a LIM molding gasket material made of the rubber composition.

  The present invention provides a sealing material that is excellent in mechanical properties and heat resistance, and particularly excellent in long-term reliability in sealing when a polar low boiling point organic solvent such as acetonitrile is used as an electrolyte in a dye-sensitized solar cell. Can be provided.

Hereinafter, the present invention will be specifically described.
The rubber composition used in the present invention comprises an ethylene / α-olefin / non-conjugated polyene copolymer [A], a SiH group-containing compound [B] having two SiH groups in one molecule, and a molecule. A SiH group-containing compound [C] having three SiH groups is contained as an essential component.

<[A] ethylene / α-olefin / non-conjugated polyene copolymer>
The copolymer [A] used in the present invention satisfies at least the following (a) to (e), and preferably satisfies the following (a) to (f).

(A) a copolymer of ethylene, α-olefin and non-conjugated polyene,
(B) the α-olefin has 3 to 20 carbon atoms,
(C) The weight ratio of ethylene unit / α-olefin unit is 35/65 to 95/5,
(D) the iodine value is in the range of 0.5-50,
(E) The intrinsic viscosity [η] measured in a decalin solution at 135 ° C. is 0.01 to 5.0 dl / g,
(F) The non-conjugated polyene is at least one norbornene compound represented by the following general formula [I].
The copolymer [A] is a copolymer of ethylene, an α-olefin having 3 to 20 carbon atoms, and a non-conjugated polyene, and preferably a random copolymer thereof.

(Α-olefin)
The α-olefin constituting the copolymer [A] is an α-olefin having 3 to 20 carbon atoms. Specifically, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-nonadecene, 1-eicocene, 9-methyl-1-decene, 11-methyl-1-dodecene, 12-ethyl-1-tetradecene, etc. Can be mentioned. Among these, α-olefins having 3 to 10 carbon atoms are more preferable, and propylene, 1-butene, 1-hexene and 1-octene are most preferably used. These α-olefins are used singly or in combination of two or more.

(Non-conjugated polyene)
The non-conjugated polyene constituting the copolymer [A] is not particularly limited, but is preferably a non-conjugated diene, more preferably at least one norbornene compound represented by the following general formula [I]. is there.

（式［Ｉ］中、ｎは、０〜１０の整数を表し、Ｒ¹は、水素原子または炭素原子数１〜１
０のアルキル基を表し、Ｒ²は、水素原子または炭素原子数１〜５のアルキル基を表す。
）

(In the formula [I], n represents an integer of 0 to 10, and R ¹ represents a hydrogen atom or a carbon atom number of 1 to 1.
0 represents an alkyl group, and R ² represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.
)

Specific examples of the norbornene compound represented by the general formula [I] include 5-vinyl-2-norbornene (VNB), 5- (2-propenyl) -2-norbornene, and 5- (3-butenyl) -2-norbornene. , 5- (1-methyl-2-propenyl) -2-norbornene, 5
-(4-pentenyl) -2-norbornene, 5- (1-methyl-3-butenyl) -2-norbornene, 5- (5-hexenyl) -2-norbornene, 5- (1-methyl-4-pentenyl) 2-norbornene, 5- (2,3-dimethyl-3-butenyl) -2-norbornene, 5- (2-ethyl-3-butenyl) -2-norbornene, 5- (6-heptenyl) -2-norbornene 5- (3-methyl-5-hexenyl) -2-norbornene, 5- (3,4-dimethyl-4-pentenyl) -2-norbornene, 5- (3-ethyl-4-pentenyl) -2-norbornene 5- (7-octenyl) -2-norbornene, 5- (2-methyl-6-heptenyl) -2-norbornene, 5- (1,2-dimethyl-5-hexesyl) -2-norbornene, 5- ( - ethyl-5-hexenyl) -2-norbornene, 5- (1,2,3-trimethyl-4-pentenyl) -2-norbornene.

  Among these, 5-vinyl-2-norbornene (VNB), 5- (2-propenyl) -2-norbornene, 5- (3-butenyl) -2-norbornene, 5- (4-pentenyl) -2-norbornene 5- (5-hexenyl) -2-norbornene, 5- (6-heptenyl) -2-norbornene and 5- (7-octenyl) -2-norbornene are preferred. These norbornene compounds can be used singly or in combination of two or more.

The non-conjugated polyene constituting the copolymer [A] may be a non-conjugated polyene other than the norbornene compound represented by the general formula [I].
Other non-conjugated polyenes that can be used are not particularly limited, and examples thereof include the following chain non-conjugated dienes, alicyclic non-conjugated dienes, and triene compounds. These can be used in combination. Moreover, non-conjugated polyenes other than the norbornene compound represented by the general formula [I] may be used together with the norbornene compound represented by the general formula [I].

  Specific examples of the chain non-conjugated diene include 1,4-hexadiene, 3-methyl-1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 4,5 -Dimethyl-1,4-hexadiene, 7-methyl-1,6-octadiene and the like.

  Specific examples of the cyclic non-conjugated diene include 5-methylene-2-norbornene, 1-methyl-5-methylene-2-norbornene, 1-ethyl-5-methylene-2-norbornene, 5-ethylidene-2-norbornene, Examples include 5-isopropylidene-2-norbornene, 5-vinylidene-2-norbornene, 6-chloromethyl-5-isopropenyl-2-norbornene, dicyclopentadiene, and methyltetrahydroindene.

  Specific examples other than the above include trienes such as 2,3-diisopropylidene-5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2,2-norbornadiene, and the like. .

(Composition and properties of copolymer [A])
The copolymer [A] has an ethylene unit / α-olefin unit ratio of 35/65 to 95/5 by weight, preferably 40/60 to 90/10, more preferably 45/55 to 85. / 15, particularly preferably 50/50 to 80/20.

  When the weight ratio is within the above range, a rubber composition capable of providing a dye-sensitized solar cell sealing material having excellent heat aging resistance, strength characteristics and rubber elasticity, as well as excellent cold resistance and processability is obtained. It is done.

  The copolymer [A] has an ethylene unit / non-conjugated polyene unit ratio in a weight ratio of 35/65 to 95/5, preferably 40/60 to 90/10, more preferably 45/55. ˜85 / 15, particularly preferably 50/50.

  When the weight ratio is within the above range, a rubber composition capable of providing a dye-sensitized solar cell sealing material having excellent electrolytic solution resistance, strength characteristics, and rubber elasticity, as well as excellent cold resistance and processability. can get.

The iodine value of the copolymer [A] is 0.5 to 50 (g / 100 g), preferably 1 to 45, more preferably 1 to 43, and particularly preferably 3 to 40 (g / 100 g). .
When the iodine value is within the above range, a rubber composition having a high crosslinking efficiency can be obtained, and the dye-sensitized solar having excellent compression set resistance and environmental degradation resistance (= heat aging resistance). A rubber composition capable of providing a battery sealing material is obtained. If the iodine value exceeds the above range, the crosslink density becomes too high, and mechanical properties such as tensile elongation may deteriorate.

  The intrinsic viscosity [η] of copolymer [A] measured in decalin at 135 ° C. is 0.01 to 5.0 dL / g, preferably 0.03 to 4.0 dL / g, more preferably 0.8. It is 05-3.5 dL / g, Most preferably, it is 0.07-3.0 dL / g. When the intrinsic viscosity [η] of the copolymer [A] is within the above range, a rubber composition capable of providing a crosslinked rubber molded article having excellent strength characteristics and compression set resistance and excellent workability is obtained. It is done. Further, an embodiment in which the intrinsic viscosity [η] of the copolymer [A] is 0.5 dL / g or less, preferably less than 0.3 dL / g, is particularly suitable when a rubber composition is LIM-molded.

Further, the copolymer [A] has a complex viscosity (25 ° C., strain 1%) measured by using a viscoelastic device MCR-301 manufactured by Anton Paar (Australia) of 10 ⁵ Pa · S or less, preferably It is desirable that the viscosity is 4,000 Pa · S or less, more preferably 2,000 Pa · S or less.

(Production method of copolymer [A])
The copolymer [A] is produced by copolymerizing ethylene, an α-olefin, and a non-conjugated polyene containing the norbornene compound represented by the formula [I] described above in the presence of a polymerization catalyst. Specifically, for example, “Polymer Production Process” (published by Industrial Research Council, Inc., pages 365-378), JP-A-9-71617, JP-A-9-71618, JP-A-9- It can be preferably prepared by a conventionally known method as described in 208615, JP-A-10-67823, JP-A-10-67824, JP-A-10-110054 and the like.

  As a polymerization catalyst, a Ziegler catalyst comprising a transition metal compound such as vanadium (V), zirconium (Zr), or titanium (Ti) and an organoaluminum compound (organoaluminum oxy compound), or an element periodic table IVB A metallocene catalyst composed of a metallocene compound of a transition metal selected from the group and an organoaluminum oxy compound or an ionized ionic compound is preferably used.

Specifically, the copolymer [A] has a polymerization temperature of 30 to 60 ° C., particularly 30 to 50 ° C. in the presence of a catalyst containing the following vanadium compound (a) and organoaluminum compound (b) as main components. The polymerization pressure is 0.4 to 1.2 MPa (= 4 to 12 kgf / cm ² ), particularly 0.5 to
Under conditions of 0.8 MPa (= 5 to 8 kgf / cm ² ) and a molar ratio of the supply amount of non-conjugated polyene and ethylene (non-conjugated polyene / ethylene) of 0.01 to 0.2, ethylene, α-olefin and , And can be suitably produced by copolymerization with the above-described non-conjugated polyene (particularly preferably a norbornene compound containing a vinyl group). The copolymerization is preferably carried out in a hydrocarbon medium.

Examples of the vanadium compound (a) include, for example, the general formula: VO (OR) _a X _b or V (OR) _c X _d (wherein R represents a hydrocarbon group, 0 ≦ a ≦ 3, 0 ≦ b ≦ 3, 2 ≦ a + b ≦ 3, 0 ≦ c ≦ 4, 0 ≦ d ≦ 4, 3 ≦ c + d ≦ 4)), or these electron donor adducts.

More specifically, VOCl ₃ , VO (OC ₂ H ₅ ) Cl ₂ , VO (OC ₂ H ₅ ) ₂ Cl, VO
_{(O-iso-C 3 H} 7) Cl 2, VO (O-n-C 4 H 9) Cl 2, VO (OC 2 H 5) 3, V
Examples include OBr ₃ , VCl ₄ , VOCl ₃ , VO (On-C ₄ H ₉ ) ₃ , VCl ₃ .2OC ₆ H ₁₂ OH, and the like. Hereinafter, “C ₂ H ₅ ” may also be referred to as “Et”, “C ₃ H ₇ ” as “Pr”, and “C ₄ H ₉ ” as “Bu”.

Specific examples of the organoaluminum compound (b) include trialkylaluminum such as triethylaluminum, tributylaluminum and triisopropylaluminum; dialkylaluminum alkoxide such as diethylaluminum ethoxide and dibutylaluminum butoxide; ethylaluminum sesquiethoxide and butyl Alkyl aluminum sesquialkoxides such as aluminum sesquibutoxide;
Formula (wherein, R represents an alkyl group having 1 to 20 carbon atoms.), Such as R _0.5 Al (OR) _0.5 partially alkoxylated alkyl aluminum to having an average composition represented by diethyl aluminum chloride Dialkylaluminum halides such as dibutylaluminum chloride and diethylaluminum bromide; Partially halogenated alkylaluminums such as aluminum dihalides; dialalkyls such as diethylaluminum hydride and dibutylaluminum hydride Partially hydrogenated alkylaluminums such as alkylaluminum dihydrides such as aluminum hydride, ethylaluminum dihydride, propylaluminum dihydride; partially alkoxy such as ethylaluminum ethoxychloride, butylaluminum butoxycyclochloride, ethylaluminum ethoxybromide And alkylated aluminum and the like.

(Other resin components)
The rubber composition used in the present invention preferably contains only the above-mentioned ethylene / α-olefin / non-conjugated polyene copolymer [A] as a resin component, but within the range not impairing the object of the present invention, A resin component other than the α-olefin / non-conjugated polyene copolymer [A] may be contained.

  As the resin component other than the copolymer [A], for example, organopolysiloxane is suitably used as an optional component. Organopolysiloxane has the effect of improving the heat aging resistance of the rubber composition and contributes to the improvement of the heat aging resistance of the encapsulant for dye-sensitized solar cells.

  When the rubber composition contains an organopolysiloxane, the content thereof is 99.9 / 0.1-5 by weight ratio of ethylene / α-olefin / non-conjugated polyene copolymer [A]: organopolysiloxane. / 95, preferably 99.9 / 0.1 to 60/40, more preferably 99.9 / 0.1 to 70/30.

Examples of the organopolysiloxane include those having an average composition formula represented by the following formula (S).
R ¹ _t SiO _{(4-t) / 2} (S)
(In the formula (S), R ¹ represents a monovalent hydrocarbon group having 1 to 10 carbon atoms, and part or all of the hydrogen atoms of the group may be substituted with a cyano group or a halogen group. , T is a number from 1.9 to 2.1.)

Specifically, R ¹ in the above formula (S) is a methyl group, an ethyl group, a propyl group, a butyl group,
Hexyl group, alkyl group such as octyl group, cycloalkyl group such as cyclopentyl group, cyclohexyl group, alkenyl group such as vinyl group, allyl group, propenyl group, cycloalkenyl group such as cyclopentenyl group, cyclohexenyl group, phenyl group, Aryl groups such as a tolyl group and xylyl group, and aralkyl groups such as a benzyl group and a phenylethyl group, and some or all of the hydrogen atoms of the group may be substituted with a chlorine atom, a fluorine atom or a cyano group .

  The organopolysiloxane includes an organopolysiloxane having a dimethylsiloxane unit in the main chain, or a diphenylsiloxane having a phenyl group, a vinyl group, a 3,3,3-trifluoropropyl group, etc. in a part of the main chain of the dimethylpolysiloxane. Particularly preferred are organopolysiloxanes having introduced units, methylvinylsiloxane units, methyl-3,3,3-trifluoropropylsiloxane units, and the like.

The organopolysiloxane preferably has two or more aliphatic unsaturated groups such as alkenyl groups and cycloalkenyl groups in one molecule, and is 0.01 to 20 mol% in R ¹ , especially 0.0.
It is preferable that 2 to 10 mol% is an aliphatic unsaturated group, particularly a vinyl group. The aliphatic unsaturated group may be at the molecular chain end, in the middle of the molecular chain, or both, but is preferably at least at the molecular chain end. Examples of the molecular chain terminal include those blocked with a trimethylsilyl group, a dimethylphenylsilyl group, a dimethylhydroxysilyl group, a dimethylvinylsilyl group, a trivinylsilyl group, and the like.

  Particularly preferable examples of the organopolysiloxane that can be used in the present invention include methyl vinyl polysiloxane, methyl phenyl vinyl polysiloxane, and methyl trifluoropropyl vinyl polysiloxane.

  Such an organopolysiloxane can be obtained by, for example, subjecting one or more organohalogenosilanes to (co) hydrolysis condensation, or cyclic polysiloxanes (such as siloxane trimers or tetramers) as alkaline or It can be obtained by ring-opening polymerization using an acidic catalyst. These are basically linear diorganopolysiloxanes, but they may be a mixture of two or three or more different molecular structures.

Organopolysiloxane can be obtained as a commercial product, or can be synthesized by a known method disclosed.
The degree of polymerization of the organopolysiloxane is preferably 100 or more, particularly preferably 3,000 to 20,000. Further, the viscosity is preferably 100 centistokes (cSt) or more at 25 ° C., and particularly preferably 100,000 to 100,000,000 cSt.

<[B] SiH group-containing compound having two SiH groups in one molecule>
The SiH group-containing compound [B] having two SiH groups in one molecule used in the present invention is a compound represented by the following general formula [II].

（式［II］中、Ｒ³は、それぞれ独立に、炭素原子数１〜１０の１価の基で、非置換また
は置換の飽和炭化水素基もしくは芳香族炭化水素基を表し、ａは、０〜２０の整数を表し、ｂは、０〜２０の整数を表し、Ｒ⁴は、炭素原子数１〜３０の２価の有機基または酸素
原子である。）

(In the formula [II], each R ³ independently represents a monovalent group having 1 to 10 carbon atoms and represents an unsubstituted or substituted saturated hydrocarbon group or aromatic hydrocarbon group, and a is 0. Represents an integer of ˜20, b represents an integer of 0 to 20, and R ⁴ represents a divalent organic group having 1 to 30 carbon atoms or an oxygen atom.)

Such a SiH group-containing compound [B] having two SiH groups in one molecule has SiH groups at both ends of the molecule, and two SiH groups per molecule. In general formula [II], specific examples of R ³ are methyl group, ethyl group, propyl group, isopropyl group, butyl group, amyl group, cyclopentyl group, hexyl group, cyclohexyl group, octyl group, chloromethyl group, 2- Examples include chloroethyl group, 3-chloropropyl group, phenyl group, phenylmethyl group, 2-phenylethyl group, 2-phenylpropyl group and the like. Preferred are a methyl group, an ethyl group, and a phenyl group. a is an integer of 0 to 20, and b is an integer of 0 to 20. Preferably, both a and b are 10 or less, more preferably 5 or less, particularly preferably 2 or less, and most preferably a and b are equally 2 or less.

Specific examples of the SiH group-containing compound [B] having two SiH groups in one molecule represented by the general formula [II] are shown below. R ⁴ in the general formula [II] is a divalent organic group having 1 to 30 carbon atoms or an oxygen atom, and specific examples of the divalent organic group are divalent in the following specific compound examples. It corresponds to the group of These SiH group-containing compounds [B] can be used alone or in combination of two or more. Moreover, SiH group containing compound [B] is compoundable by the well-known method disclosed.

これらのうち、本発明で特に好ましく用いられる、１分子中にＳｉＨ基を２個有するＳｉＨ基含有化合物［Ｂ］は、下記式［II−１］で表される化合物である。

Among these, the SiH group-containing compound [B] having two SiH groups in one molecule, which is particularly preferably used in the present invention, is a compound represented by the following formula [II-1].

このような化合物を［Ｂ］成分として用いることにより、従来の優れた諸特性を維持しつつ、さらに機械特性を向上させた最も優れた特性を有する色素増感型太陽電池用封止材を得ることができる。

By using such a compound as the component [B], a sealing material for a dye-sensitized solar cell having the most excellent characteristics with improved mechanical characteristics is obtained while maintaining various conventional characteristics. be able to.

  Such a SiH group-containing compound [B] having two SiH groups in one molecule has a hydrogen atom bonded to a silicon atom per aliphatic unsaturated bond contained in the resin component in the rubber composition. It is preferable to contain in the quantity which gives 0.2-10 pieces.

In the rubber composition used in the present invention, the content of the SiH group-containing compound [B] having two SiH groups in one molecule is 100 parts by weight of ethylene / α-olefin / non-conjugated polyene copolymer [A]. The ratio is preferably 2 to 15 parts by weight, more preferably 3 to 8 parts by weight, from the viewpoint of the rubber hardness of the molded product.

  In addition, such a SiH group-containing compound [B] having two SiH groups in one molecule was added alone to the ethylene / α-olefin / non-conjugated polyene copolymer [A], that is, ethylene / The rubber composition containing the α-olefin / non-conjugated polyene copolymer [A] and the SiH group-containing compound [B] having two SiH groups in one molecule can suppress the crosslinking density to some extent, Although it has excellent elongation characteristics, there is room for improvement in that the compression set rate is particularly high at low temperatures (−30 ° C.) and the recoverability is poor.

<[C] SiH group-containing compound having three SiH groups in one molecule>
The SiH group-containing compound [C] having three SiH groups in one molecule used in the present invention is a compound represented by the following general formula [III].

（式［III］中、Ｒ⁵は、それぞれ独立に、炭素原子数１〜１０の１価の基であって、非置換または置換の飽和炭化水素基もしくは芳香族炭化水素基を表し、ａ、ｂおよびｃは、それぞれ独立に、０〜２０の整数を表し、Ｒ⁶は、炭素原子数１〜３０の３価の有機基を表
す。）
このようなＳｉＨ基含有化合物［Ｃ］は、分子の３つの末端にＳｉＨ基を有し、１分子中にＳｉＨ基を３個有する。

(In the formula [III], each R ⁵ independently represents a monovalent group having 1 to 10 carbon atoms, and represents an unsubstituted or substituted saturated hydrocarbon group or aromatic hydrocarbon group, a, b and c each independently represents an integer of 0 to 20, and R ⁶ represents a trivalent organic group having 1 to 30 carbon atoms.)
Such a SiH group-containing compound [C] has SiH groups at three terminals of the molecule and three SiH groups in one molecule.

R ⁵ in the general formula [III] is exemplified by the same as R ^{3 in the} general formula [II]. Specifically,
Methyl group, ethyl group, propyl group, isopropyl group, butyl group, amyl group, cyclopentyl group, hexyl group, cyclohexyl group, octyl group, chloromethyl group, 2-chloroethyl group, 3-chloropropyl group, phenyl group, phenylmethyl Group, 2-phenylethyl group, 2-phenylpropyl group and the like. Preferred are a methyl group, an ethyl group, and a phenyl group. a, b and c are each independently an integer of 0 to 20, preferably a, b and c are both 10 or less, more preferably 5 or less, particularly preferably 2 or less, most preferably a, b and c are equally less than or equal to 2. R ⁶ in the general formula [III] is a trivalent organic group having 1 to 30 carbon atoms, preferably a trivalent organic group having 1 to 30 carbon atoms containing silicon.

  As a particularly preferred SiH group-containing compound [C] having three SiH groups in one molecule, a compound represented by the following formula [III-1] can be exemplified.

本発明で用いられるゴム組成物における、１分子中にＳｉＨ基を３個有するＳｉＨ基含有化合物［Ｃ］の含有量は、エチレン・α−オレフィン・非共役ポリエン共重合体［Ａ］１００重量部に対して、好ましくは０．０５〜２重量部、より好ましくは０．１〜１．４重量部の割合であることが望ましい。

In the rubber composition used in the present invention, the content of the SiH group-containing compound [C] having 3 SiH groups in one molecule is 100 parts by weight of ethylene / α-olefin / non-conjugated polyene copolymer [A]. The ratio is preferably 0.05 to 2 parts by weight, more preferably 0.1 to 1.4 parts by weight.

  A rubber composition obtained by adding one SiH group-containing compound [C] having three SiH groups in one molecule to the ethylene / α-olefin / non-conjugated polyene copolymer [A] alone is as follows: Three-dimensional cross-linking and improved physical properties of rubber such as mechanical strength, but it is inferior in recoverability and easy to cause scorch and poor handling during molding. Although it is unsuitable for use as an SiH group-containing compound [B] having two SiH groups in one molecule and an SiH group-containing compound [C] having three SiH groups in one molecule, ethylene The rubber composition of the present invention added in combination with the α-olefin / non-conjugated polyene copolymer [A] has good moldability, excellent heat resistance, barrier properties, and sealing properties, and at high temperatures ( 150 ° C) and In addition, the compression set at a low temperature (−30 ° C.) is low, the recovery property is excellent, and it can be suitably used for a sealing material for a dye-sensitized solar cell.

<Rubber composition>
The rubber composition used in the present invention comprises an ethylene / α-olefin / non-conjugated polyene copolymer [A], a SiH group-containing compound [B] having two SiH groups in one molecule, and a molecule. It contains a SiH group-containing compound [C] having three SiH groups as an essential component, and if necessary, contains an organopolysiloxane, a catalyst described later or a reaction inhibitor, and other components as necessary. Yes.

(Preparation of rubber composition)
For example, the rubber composition may be prepared by using a copolymer [A] by a kneading apparatus such as an internal mixer (sealed mixer) such as a Banbury mixer, a kneader, a planetary mixer, or an intermix, a two-roll, or a three-roll. And, if necessary, the organopolysiloxane together with other components such as a rubber reinforcing agent, an inorganic filler and a softening agent, preferably at a temperature of 50 to 180 ° C. for 3 to 10 minutes, and then like an open roll. Using rolls or kneaders, the SiH group-containing compounds [B] and [C] are added and, if necessary, the catalyst and reaction inhibitor, which will be described later, and further a vulcanization accelerator and a crosslinking aid. After kneading at a roll temperature of 100 ° C. or lower for 1 to 30 minutes, “dispensing”, that is, passing a roll gap, a sheet having a predetermined thickness, width and length is obtained. It can be prepared by Seisuru.
In addition, when the kneading temperature in the internal mixer is low, all the components constituting the rubber composition may be mixed and kneaded at the same time.

(Crosslinking method)
-Catalyst In the production of the rubber composition used in the present invention, when crosslinking is performed using the SiH group-containing compounds [B] and [C], the catalyst used in the crosslinking is an addition reaction catalyst, and the copolymer [A] In addition, the alkenyl group of the organopolysiloxane used as needed and the SiH group-containing compounds [B] and [C] with an SiH group promote the addition reaction (such as alkene hydrosilylation reaction).

  As such a catalyst, for example, a platinum-based catalyst such as a platinum-based catalyst, a palladium-based catalyst, or a rhodium-based catalyst is usually used. However, in the present invention, a platinum-based catalyst is preferable. It is desirable to use a complex of a group 8 element metal of the periodic table including a platinum-based catalyst, particularly preferably platinum and a compound containing a vinyl group and / or a carbonyl group.

  As the compound containing a carbonyl group, carbonyl, octanal and the like are preferable. Specific examples of the complex of these with platinum include a platinum-carbonyl complex, a platinum-octanal complex, a platinum-carbonylbutyl cyclic siloxane complex, and a platinum-carbonylphenyl cyclic siloxane complex.

  As the compound containing a vinyl group, a vinyl group-containing organosiloxane is preferable. Specific examples of complexes of these with platinum include platinum-divinyltetramethyldisiloxane complex, platinum-divinyltetraethyldisiloxane complex, platinum-divinyltetrapropyldisiloxane complex, platinum-divinyltetrabutyldisiloxane complex, platinum -Divinyltetraphenyldisiloxane complex.

  Among the vinyl group-containing organosiloxanes, vinyl group-containing cyclic organosiloxanes are preferable. Examples of the complex of platinum with platinum include a platinum-vinylmethyl cyclic siloxane complex, a platinum-vinylethyl cyclic siloxane complex, and a platinum-vinylpropyl cyclic siloxane complex.

  The vinyl group-containing organosiloxane itself may be a ligand for a metal, but may be used as a solvent for coordinating other ligands. A complex in which a vinyl group-containing organosiloxane is used as a solvent and the above-mentioned compound containing a carbonyl group is a ligand is particularly preferable as a catalyst.

  Specific examples of such complexes include a platinum-carbonyl complex vinylmethyl cyclic siloxane solution, a platinum-carbonyl complex vinylethyl cyclic siloxane solution, a platinum-carbonyl complex vinylpropyl cyclic siloxane solution, and a platinum-carbonyl complex divinyl. Tetramethyldisiloxane solution, platinum-carbonyl complex divinyltetraethyldisiloxane solution, platinum-carbonyl complex divinyltetrapropyldisiloxane solution, platinum-carbonyl complex divinyltetrabutyldisiloxane solution, platinum-carbonyl complex divinyltetraphenyldi A siloxane solution is mentioned.

  The catalyst comprising these complexes may further contain components other than the compound containing a vinyl group and / or a carbonyl group. For example, a solvent other than a compound containing a vinyl group and / or a carbonyl group may be contained. Examples of these solvents include various alcohols and xylene, but are not limited thereto.

Specific examples of the alcohol include aliphatic saturated alcohols represented by methanol and ethanol; aliphatic unsaturated alcohols such as allyl alcohol and crotyl alcohol; alicyclic alcohols such as cyclopentanol and cyclohexanol; benzyl Aromatic alcohols such as alcohol and cinnamyl alcohol; heterocyclic alcohols such as furfuryl alcohol and the like.

  An example of using alcohol as a solvent is a platinum-octanal / octanol complex. By including these solvents, there are advantages such as easy handling of the catalyst and easy mixing with the rubber composition.

  Among the various catalysts listed above, a platinum-carbonyl complex vinylmethyl cyclic siloxane solution (in particular, a complex represented by the following chemical formula 1 is preferred), a platinum-vinylmethyl cyclic siloxane complex (among others, represented by chemical formula 2). A complex is preferred), a platinum-divinyltetramethyldisiloxane complex (among others, a complex represented by Chemical Formula 3 is preferred), a platinum-octanal / octanol complex, etc. are practically preferred, and among them, a platinum-carbonylvinylmethyl cyclic siloxane. Complexes are particularly preferred.

Chemical formula 1: Pt ⁰ .CO. (CH ₂ ═CH (Me) SiO) ₄
Chemical formula 2: Pt ⁰ · (CH ₂ ═CH (Me) SiO) ₄
Chemical formula 3: Pt ⁰ -1.5 [(CH ₂ ═CH (Me) ₂ Si) ₂ O]
The ratio of Group 8 element metal (preferably platinum) contained in these catalysts is usually 0.1 to 10% by weight, preferably 1 to 5% by weight, more preferably 2 to 4% by weight, particularly preferably. Is 2.5 to 3.5% by weight.

  Although a catalyst is not specifically limited, 0.1-100,000 weight ppm with respect to the sum total of copolymer [A] and the organopolysiloxane added as needed, Preferably it is 0.00. 1 to 10,000 ppm by weight, more preferably 1 to 5,000 ppm by weight, and particularly preferably 5 to 1,000 ppm by weight. When the catalyst is used in a proportion within the above range, a rubber composition capable of forming a crosslinked rubber molded article having an appropriate crosslinking density and excellent strength properties and elongation properties can be obtained. If the catalyst is used in a proportion exceeding 100,000 ppm by weight, it is not preferable because it is disadvantageous in cost. It is also possible to obtain a crosslinked rubber molded article by irradiating an uncrosslinked rubber molded article of a rubber composition not containing a catalyst with light, γ-ray, electron beam or the like.

  In the crosslinking of the rubber composition, both addition crosslinking and radical crosslinking may be performed using an organic peroxide in addition to the above catalyst. The organic peroxide is used in a proportion of about 0.1 to 10 parts by weight with respect to 100 parts by weight as a total of the copolymer [A] and the organopolysiloxane added as necessary. As the organic peroxide, a conventionally known organic peroxide that is usually used in crosslinking of rubber can be used.

-Reaction inhibitor In crosslinking, it is preferable to use a reaction inhibitor together with the above catalyst. Reaction inhibitors include benzotriazole (for example, ethynyl group-containing alcohols such as ethynylcyclohexanol, acrylonitrile, N, N-diallylacetamide, N, N-diallylbenzamide, N, N, N ′, N′-tetraallyl-o Amide compounds such as phthalic acid diamide, N, N, N ′, N′-tetraallyl-m-phthalic acid diamide, N, N, N ′, N′-tetraallyl-p-phthalic acid diamide, sulfur, phosphorus, nitrogen And organic peroxides such as amine compounds, sulfur compounds, phosphorus compounds, tin, tin compounds, tetramethyltetravinylcyclotetrasiloxane, and hydroperoxide.

The reaction inhibitor is 0 to 50 parts by weight, usually 0.0001 to 50 parts by weight, preferably 0 to 100 parts by weight in total of the copolymer [A] and the organopolysiloxane added as necessary. 0.0001 to 30 parts by weight, more preferably 0.0001 to 20 parts by weight, still more preferably 0.0001 to 10 parts by weight, and particularly preferably 0.0001 to 5 parts by weight. Use of a reaction inhibitor in a proportion exceeding 50 parts by weight is not preferable because it is disadvantageous in cost.

-Other components Depending on the intended use of the crosslinked product in the rubber composition, conventionally known rubber reinforcing agents, inorganic fillers, softeners, anti-aging agents, processing aids, vulcanization accelerators, organic peroxides, etc. Additives such as oxides, crosslinking aids, foaming agents, foaming aids, colorants, dispersants, flame retardants and the like can be blended within a range that does not impair the object of the present invention. A typical example is taken as a filler or a compounding agent, and will be specifically described below.

(I) Rubber Reinforcing Agent A rubber reinforcing agent has an effect of enhancing mechanical properties such as tensile strength, tear strength, and abrasion resistance of a crosslinked (vulcanized) rubber. Specific examples of such rubber reinforcing agents include carbons such as SRF, GPF, FEF, HAF, ISAF, SAF, FT, and MT, and those carbons that have been surface-treated with a silane coupling agent. Examples thereof include black, finely divided silicic acid, and silica.

  In the rubber composition, even if the use of rubber reinforcing materials such as carbon black is omitted, a rubber composition that can provide a sealing material excellent in strength and sealing properties can be obtained, but a rubber reinforcing material such as carbon black is blended. By doing so, further improved strength can be obtained. When carbon black is used as the rubber reinforcing material, the amount used is 1 to 300 parts by weight with respect to 100 parts by weight in total of the copolymer [A] and the organopolysiloxane added as necessary. The amount is preferably 1 to 200 parts by weight, more preferably 1 to 100 parts by weight, particularly preferably 1 to 50 parts by weight, and most preferably 10 to 50 parts by weight. In the rubber composition, suitable electrical insulation can be maintained even if carbon black is blended.

Specific examples of silica include fumed silica and precipitated silica. These silicas may be surface-treated with a reactive silane such as hexamethyldisilazane, chlorosilane, or alkoxysilane, or a low molecular weight siloxane. The specific surface area of silica (BET method) is preferably 10 m ² / g or more, more preferably 30~500m ² / g.

In the present invention, the carbon black has an iodine adsorption of 80 mg / g or less, preferably 15 to 40 mg / g, an average particle size of 250 nm or less, preferably 40 to 100 nm, and a DBP absorption of 10 to 300 cm ^3. / 100 g, preferably it can be suitably used for 40~150cm ³ / 100g, for example, FEF grade, GPF grade carbon black such as SRF grade is preferably used. The “DBP absorption amount” indicates the degree of aggregation and aggregation of particles depending on the amount of DBP (dibutyl phthalate) required to fill the voids between the carbon black particles.

When such carbon black is used, the BET specific surface area indicating the primary particle diameter is 30 to 80 m ² / g, preferably 40 to 60 m ² / g, and particles by the Cole Counter method indicating the secondary particle diameter. When a surface-modified precipitated silica (hydrous silicic acid) having a diameter of 1 to 4 μm, preferably 1.5 to 3 μm, is used in combination, a molded article having a low compression set under a high temperature environment and excellent recoverability can be obtained. Therefore, it is preferable.

The type and blending amount of these rubber reinforcing agents can be appropriately selected depending on the application, but the blending amount of the rubber reinforcing agent is usually added as necessary with the ethylene / α-olefin / non-conjugated polyene copolymer [A]. The maximum amount is 300 parts by weight, preferably 200 parts by weight, based on a total of 100 parts by weight with the organopolysiloxane. These rubber reinforcing agents can be used alone or in combination of two or more.

(Ii) Inorganic filler Specific examples of the inorganic filler include light calcium carbonate, heavy calcium carbonate, talc, clay, and diatomaceous earth. These inorganic fillers can be used alone or in combination of two or more. The type and blending amount of these inorganic fillers can be appropriately selected depending on the application, but the blending amount of the inorganic filler is usually a total of 100 of the copolymer [A] and the organopolysiloxane added as necessary. It is 1-300 weight part with respect to a weight part, Preferably it is 200 weight part.

(Iii) Softening agent As the softening agent, a known softening agent usually used for rubber can be used. Specifically, process oil, lubricating oil, paraffin, liquid paraffin, petroleum asphalt, petroleum softener such as petroleum jelly, coal tar softener such as coal tar and coal tar pitch, castor oil, linseed oil, rapeseed oil, Fatty oil-based softeners such as coconut oil, waxes such as beeswax, carnauba wax, lanolin, fatty acids and fatty acid salts such as ricinoleic acid, palmitic acid, barium stearate, calcium stearate, zinc laurate, petroleum resin, atactic polypropylene Synthetic polymers such as coumarone indene resin, and others include tall oil and sub. Of these, petroleum softeners are preferably used, and process oil is particularly preferably used. The blending amount of these softeners is appropriately selected depending on the use of the crosslinked product. These softeners can be used alone or in combination of two or more.

(Iv) Anti-aging agent As the anti-aging agent, all conventionally known anti-aging agents are used, and examples thereof include amine-based, hindered phenol-based or sulfur-based anti-aging agents, and the amount of the anti-aging agent is the present invention. It is used within a range not to impair the purpose. In addition, the anti-aging agents exemplified below can be used alone or in combination of two or more in the same system or between different systems in the amine system, hindered phenol system, and sulfur system. .

Examples of amine-based antioxidants include diphenylamines and phenylenediamines. In particular, 4,4 ′-(α, α-dimethylbenzyl) diphenylamine, N, N′-di-2-
Naphthyl-p-phenylenediamine is preferred.

  Hindered phenolic antioxidants include tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate methane, and 3,9-bis [2- {3- (3-tert-Butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane phenol Compounds are preferred.

  Sulfur-based antioxidants include, in particular, 2-mercaptobenzimidazole, zinc salt of 2-mercaptobenzimidazole, 2-mercaptomethylbenzimidazole, zinc salt of 2-mercaptomethylbenzimidazole, pentaerythritol-tetrakis- (β-lauryl) -Thiopropionate) is preferred.

(V) Processing aids As the processing aids, known compounds used in normal rubber processing can be used. Specifically, higher fatty acids such as ricinoleic acid, stearic acid, palmitic acid and lauric acid; salts of higher fatty acids such as barium stearate, zinc stearate and calcium stearate; ricinoleic acid, stearic acid, palmitic acid and lauric acid And higher fatty acid esters. The amount of the processing aid is 10 parts by weight or less, preferably 5 parts by weight or less, based on 100 parts by weight of the total amount of the copolymer [A] and the organopolysiloxane added as necessary. However, it is desirable to appropriately determine the optimum amount according to the required physical property value.

(Vi) Crosslinking aid When an organic peroxide is used in the crosslinking of the rubber composition, it is preferable to use a crosslinking aid in combination. Specific examples of the crosslinking aid include sulfur, quinone dioxime compounds such as p-quinone dioxime, methacrylate compounds such as polyethylene glycol dimethacrylate, allyl compounds such as diallyl phthalate and triallyl cyanurate, maleimide compounds, Examples include divinylbenzene. Such a crosslinking aid is used in an amount of 0.5 to 2 mol, preferably about equimolar to 1 mol of the organic peroxide used.

(Vii) Other resin component In the rubber composition, other rubbers known as other resin components can be used in combination as long as the object of the present invention is not impaired. Specific examples include natural rubber (NR). And conjugated diene rubbers such as isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), and chloroprene rubber (CR). .

  Further, ethylene / α-olefin / non-conjugated polyene copolymers other than conventionally known ethylene / α-olefin copolymer rubbers such as ethylene / propylene random copolymer (EPR) and the copolymer [A] of the present invention are used. As the polymerization, an ethylene / propylene / non-conjugated diene copolymer (EPDM or the like) can be used.

<Encapsulant for dye-sensitized solar cell>
(Molding / crosslinking method)
The rubber composition used in the present invention is excellent in mechanical properties and heat resistance. Especially when a polar low boiling point organic solvent such as acetonitrile is used as an electrolyte in a dye-sensitized solar cell, long-term reliability in sealing is achieved. In particular, it can be suitably used for applications such as a sealing material having excellent resistance. The rubber composition used in the present invention is particularly suitable for a LIM molding gasket material, but a molded article can also be produced by other molding methods.

The encapsulant for dye-sensitized solar cell of the present invention can exhibit its characteristics most when used as a crosslinked rubber molded product.
In order to produce a crosslinked rubber molded article from the rubber composition used in the present invention, an uncrosslinked rubber composition is once prepared by the preparation method described above, as in the case of vulcanizing (crosslinking) ordinary rubber. It is preferred to prepare and then crosslink after molding the rubber composition into the desired shape.

  When a molded product having a desired shape is produced from the composition of the present invention prepared as described above, a LIM molding machine, an injection molding machine, a transfer molding machine, a press molding machine, an extrusion molding machine, a calender machine, For example, an ink jet molding machine or a screen printing machine can be used. Among these, the LIM molding machine is suitable for manufacturing each target material of the present invention in terms of thickness accuracy and high speed molding. Injection molding and compression molding are also suitable.

Crosslinking can be performed simultaneously with molding or by introducing the molded product into a vulcanizing tank.
For example, the rubber composition of the present invention mixed using various kneading apparatuses such as three mill rolls, open rolls, two open rolls, a Banbury mixer, an internal mixer, a kneader, a planetary mixer, and a high shear mixer, A product obtained by molding under a crosslinking condition of 80 to 230 ° C., preferably 100 to 180 ° C. and subjected to crosslinking (primary vulcanization) is about 100 to 230 ° C., preferably about 0 to about 120 to 150 ° C. if necessary. Forming and crosslinking can be performed by heat treatment (secondary vulcanization) in an air oven such as a gear oven or a thermostatic bath for about 5 to 24 hours.

  Crosslinking (primary vulcanization) or secondary crosslinking (secondary vulcanization) may be performed by irradiating light, γ rays, electron beams, etc., and both primary vulcanization and secondary vulcanization are performed at room temperature. You can also. By the above-described method, a crosslinked rubber molded product, that is, the dye-sensitized solar cell sealing material of the present invention is obtained.

  In this crosslinking step, a mold may be used, or the crosslinking may be performed without using a mold. When a mold is not used, the molding and crosslinking processes are usually carried out continuously. As a heating method in the vulcanization tank, a heating tank such as hot air, glass bead fluidized bed, UHF (ultra-high frequency electromagnetic wave), steam or the like can be used.

(LIM molding)
When the rubber composition used in the present invention is applied particularly to a gasket material for LIM molding, a composition (a) containing the copolymer [A] and SiH group-containing [B] and [C], A composition (b) containing the polymer [A] and the above catalyst is prepared, and both (a) and (b) are mixed by a LIM molding apparatus to prepare the rubber composition of the present invention. It is preferable to mold together.

  In preparing the rubber composition used in the present invention and in the production of a molded body (for example, a sealing material), it is properly used depending on the viscosity of the material used, but like a Banbury mixer, a kneader, or an intermix Such internal mixers (closed mixers) and agitators such as planetary mixers are used. In the present invention, by such a stirrer, the copolymer [A], SiH group-containing compound [B], [C] and other resin components, rubber reinforcing agents, inorganic fillers, softeners, and other additives are added. Kneading for 10 minutes to prepare a liquid rubber composition (1).

  On the other hand, copolymer [A], other resin components, rubber reinforcing agent, inorganic filler, softener and other additives and the above catalyst, and if necessary, a reaction inhibitor are kneaded for 3 to 10 minutes to form a liquid rubber composition A product (2) is prepared. In preparing the composition (1) or the composition (2), it is preferable to perform defoaming. Subsequently, the liquid rubber composition (1) and the liquid rubber composition (2) are put into a dedicated pail can or a directly connectable cartridge that can be directly connected to the LIM molding apparatus, and the LIM molding is performed through a metering and mixing apparatus. The dye-sensitized solar cell sealing material of the present invention, which is preferably a LIM molding gasket material, can be obtained.

(Physical properties / characteristics)
It is preferable that the sealing material for dye-sensitized solar cells of the present invention does not have voids due to foaming or the like. When there is a void due to foaming or the like, the dye-sensitized solar cell sealing material may swell with respect to the electrolytic solution.

The volume specific resistance of the encapsulant for dye-sensitized solar cells of the present invention is preferably 1 × 10 ¹² ohm · cm or more, which is judged to have electrical insulation. Volume resistivity is one of the characteristics required for a sealing material used for electric / electronic parts and is an index of electrical insulation. More preferably, it is 1 × 10 ¹² ohm · cm or more, and shows suitable performance as a sealing material. The volume resistivity is measured according to SRIS2301-1969 using a 1 mm thick sheet obtained by press-crosslinking the rubber composition at a pressure of 40 kgf / cm ² at 150 ° C. for 10 minutes.

In the encapsulant for dye-sensitized solar cell of the present invention, the durometer hardness A indicating the surface hardness of the cured product layer is desirably 10 or more and 70 or less, preferably 30 or more and 50 or less. The durometer hardness A is an index of hardness and can be measured according to JIS K6253. In order to make the durometer hardness A within the above range, it is possible to adjust various addition ratios of various reinforcing agents, fillers, plasticizers and the like in the composition, and these various additives are not added. Those also show the desired low hardness. The lower limit is 10 or more, and if it exceeds the lower limit, it is too soft, and the performance of sealing a dye-sensitized solar cell is poor. However, as the reinforcing agent and filler, those containing a substance that becomes a catalyst poison such as sulfur or a halogen compound are not preferable. Moreover, an upper limit is 70 or less, and when it exceeds an upper limit, elongation and compression set may be inferior.

The present invention can provide a sealing material that is excellent in long-term reliability in sealing when a polar low-boiling organic solvent such as acetonitrile is used as an electrolyte in a dye-sensitized solar cell.
Specifically, acetonitrile (51.8 parts by weight), iodine (3.3 parts by weight), lithium iodide (3.5 parts by weight) and 1,2-dimethyl-3-propylimidazolium iodide (41. 4 parts by weight), the dye-sensitized solar cell sealing material of the present invention is immersed for 1,000 hours in an electrolyte solution heated to 85 ° C., and the following (1) to (4) before and after immersion: Measure physical properties.

(1) Durometer hardness A
In accordance with JIS K6253, when a durometer hardness test (type A durometer) is performed at a measurement temperature of 23 ° C. and the durometer hardness A (points) is measured, the dye-sensitized solar cell after immersion compared to before immersion The durometer hardness A of the sealing material is preferably 80 to 100%, more preferably 85 to 100%.

(2) Tensile strength and elongation In accordance with JIS K6251, a tensile test is performed at a measurement temperature of 23 ° C. and a tensile speed of 500 mm / min to measure the tensile strength (MPa) and elongation (%) at break of the crosslinked sheet. In this case, the tensile strength and the elongation of the dye-sensitized solar cell encapsulant after immersion as compared with those before immersion are preferably 70 to 100%, more preferably 80 to 100%, respectively.

(3) Tear strength When tear strength (N / mm) is measured at a measurement temperature of 25 ° C. in accordance with JIS K6251, tear of the encapsulant for dye-sensitized solar cells after immersion compared to before immersion The strength is preferably 100 to 120%.

(4) Volume change rate When the volume change rate (%) before and after immersion is measured according to JIS K6258, the volume change rate of the dye-sensitized solar cell encapsulant after immersion is compared with that before immersion. , Preferably +0 to 2%, more preferably +0 to 1.5%.

  Next, although an Example is shown and this invention is demonstrated further in detail, this invention is not limited by these.

[Preparation Example 1]
Using a stainless steel polymerization vessel (stirring rotation speed = 250 rpm) with a substantial internal volume of 100 liters equipped with stirring blades, ethylene, propylene and 5-vinyl-2-norbornene (the following formula: hereinafter abbreviated as “VNB”) )). From the side of the polymerization vessel to the liquid phase, 60 liters of hexane per hour, 1.3 kg of ethylene, 2.5 kg of propylene, 130 g of VNB, 30 liters of hydrogen, 23 VO (OEt) Cl ₂ as a catalyst Mmol, Al (Et) _1.5 Cl _1.5 was continuously fed at a rate of 161 mmol, and a copolymerization reaction was carried out under the conditions of a polymerization temperature of 40 ° C. and a polymerization pressure of 0.7 MPa, and an ethylene / propylene / VNB random copolymer ( A-1) (hereinafter also referred to as “copolymer (A-1)”) was obtained in a homogeneous solution state. Thereafter, a small amount of methanol is added to the polymerization solution continuously withdrawn from the lower part of the polymerization vessel to stop the polymerization reaction, and the polymer is separated from the solvent by a steam stripping treatment, followed by vacuum drying at 55 ° C. for 48 hours. Went.

得られた共重合体（Ａ−１）のエチレン含量は５２．７重量％、プロピレン含量は４２．６重量％、およびＶＮＢ含量は４．７重量％であり、ヨウ素価が９．５ｇ／１００ｇであって、２５℃における複素粘度（Ａｎｔｏｎ Ｐａａｒ社（オーストラリア）製の粘弾性装置ＭＣＲ−３０１を用いて測定した複素粘度）は１１００Ｐａ・Ｓ、１３５℃のデカリン溶液中で測定した極限粘度［η］は０．２８ｄＬ／ｇであった。なお、共重合体（Ａ−１）の組成は¹³Ｃ−ＮＭＲ法での測定で求めた値である。

The obtained copolymer (A-1) has an ethylene content of 52.7% by weight, a propylene content of 42.6% by weight, a VNB content of 4.7% by weight and an iodine value of 9.5 g / 100 g. The complex viscosity at 25 ° C. (complex viscosity measured using a viscoelastic device MCR-301 manufactured by Anton Paar (Australia)) was 1100 Pa · S, and the intrinsic viscosity measured in a decalin solution at 135 ° C. [η ] Was 0.28 dL / g. In addition, the composition of a copolymer (A-1) is the value calculated | required by the measurement by < ¹³ > C-NMR method.

[Example 1]
100 parts by weight of copolymer (A-1) obtained in Preparation Example 1 and carbon black (Asahi Carbon 50 Asahi # 50HG, iodine adsorption amount: 19 mg / g, average particle diameter 85 μm, DBP absorption amount:
110 cm ^3/100 g) and 15 parts by weight, the surface-treated precipitated silica (manufactured by Tosoh Silica Corporation Nipsil E75SS, BET surface area: 50 m ² / g, average particle size was determined by the secondary particle diameter (Coulter counter method): 2 .4 μm, M value: 65) 30 parts by weight were kneaded in a range of 50 to 80 ° C. with a 2 liter planetary mixer [manufactured by Inoue Seisakusho, trade name: PLM-2 type]. The “M value” in the surface-treated precipitated silica is a general index indicating the degree of silica modification treatment, and added to the silica subject to M value evaluation by changing the methanol concentration of the aqueous methanol solution. At this time, it is a value represented by the methanol aqueous solution concentration (vol% of methanol) when affinity begins (begins to wet).

Then, platinum-1,3,5,7-tetravinylmethylcyclosiloxane complex [platinum concentration 0.5 wt%, terminal vinylsiloxane oil solution] 0.4 parts by weight as a catalyst, and 1-ethynyl as a reaction inhibitor As a crosslinking agent, 0.1 part by weight of -1-cyclohexanol, 4.8 parts by weight of a compound represented by the following formula [II-1] as a crosslinking agent, and 0.8% of a compound represented by the following formula [III-1]. A rubber composition was prepared by adding 1 part by weight and mixing.

  Next, the obtained rubber composition was poured into a test sheet mold (140 × 100 × 2 mm), and compression molded for 5 minutes at a hot plate set temperature of 150 ° C. and a mold compression of 80 MPa to obtain a crosslinked rubber sheet. Then, secondary vulcanization at 150 ° C. for 1 hour was carried out to obtain a secondary vulcanized product of the crosslinked rubber sheet (secondary vulcanized crosslinked rubber sheet).

得られた二次加硫架橋ゴムシートを、８５℃の電解液に１，０００時間浸漬し、浸漬前後の各性状を以下の方法で測定した。

The obtained secondary vulcanized crosslinked rubber sheet was immersed in an electrolytic solution at 85 ° C. for 1,000 hours, and the properties before and after the immersion were measured by the following methods.

  The electrolytic solution was acetonitrile (51.8% by weight), iodine (3.3% by weight), lithium iodide (3.5% by weight), 1,2-dimethyl-3-propylimidazolium iodide. Compound (41.4% by weight).

The results are shown in Table 1.
(1) Durometer hardness A
In accordance with JIS K6253, a durometer hardness test (type A durometer) was performed at a measurement temperature of 23 ° C. to measure durometer hardness A (points).

(2) Tensile strength and elongation In accordance with JIS K6251, a tensile test is performed at a measurement temperature of 23 ° C. and a tensile speed of 500 mm / min to measure the tensile strength (MPa) and elongation (%) at break of the crosslinked sheet. did.

(3) Tear Strength Based on JIS K6251, the tear strength (N / mm) was measured at a measurement temperature of 25 ° C.

(4) Volume change rate Volume change rate (%) before and after immersion was measured according to JIS K6258.

  The present invention provides a sealing with excellent long-term reliability when used as a sealing material for a dye-sensitized solar cell using a polar low boiling point organic solvent such as acetonitrile as an electrolyte. Since the material can be provided, it is suitable not only for various gaskets for dye-sensitized solar cells but also for sealing materials including various packings.

Claims (7)

An ethylene / α-olefin / non-conjugated polyene copolymer satisfying the following (a) to (e):
A],
(A) a copolymer of ethylene, α-olefin and non-conjugated polyene,
(B) the α-olefin has 3 to 20 carbon atoms,
(C) The weight ratio of ethylene unit / α-olefin unit is 35/65 to 95/5,
(D) the iodine value is in the range of 0.5-50,
(E) Intrinsic viscosity [η] measured in a decalin solution at 135 ° C. is 0.01 to 5.0 d
L / g;
SiH group-containing compound having two SiH groups in one molecule represented by the following general formula [II] [
B]
A dye-sensitized dye comprising a rubber composition containing a SiH group-containing compound [C] having three SiH groups in one molecule, represented by the following general formula [III]: Solar cell encapsulant;

(In the formula [II], each R ³ independently represents a monovalent group having 1 to 10 carbon atoms and represents an unsubstituted or substituted saturated hydrocarbon group or aromatic hydrocarbon group, and a is 0. Represents an integer of ˜20, b represents an integer of 0 to 20, and R ⁴ represents a divalent organic group having 1 to 30 carbon atoms or an oxygen atom).

(In the formula [III], each R ⁵ independently represents a monovalent group having 1 to 10 carbon atoms, and represents an unsubstituted or substituted saturated hydrocarbon group or aromatic hydrocarbon group, a, b and c each independently represents an integer of 0 to 20, and R ⁶ represents a trivalent organic group having 1 to 30 carbon atoms. 2. The dye-sensitized solar cell according to claim 1, wherein the non-conjugated polyene for producing the ethylene / α-olefin / non-conjugated polyene copolymer [A] further satisfies the following (f): Sealing material;
(F) The non-conjugated polyene is at least one norbornene compound represented by the following general formula [I].

(In the formula [I], n represents an integer of 0 to 10, and R ¹ represents a hydrogen atom or a carbon atom number of 1 to 1.
0 represents an alkyl group, and R ² represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. ) For 100 parts by weight of the ethylene / α-olefin / non-conjugated polyene copolymer [A],
Sealing dye-sensitized solar cell according to claim 1 or 2, characterized in that it contains 0.1 to 2 parts by weight of SiH group-containing compound [C] having three SiH groups in the molecule Wood. The SiH group-containing compound [C] having three SiH groups in one molecule is a compound represented by the following formula [III-1]. Dye-sensitized solar cell encapsulant.

For 100 parts by weight of the ethylene / α-olefin / non-conjugated polyene copolymer [A],
The dye-sensitized solar cell seal according to any one of claims 1 to 4, comprising 2 to 15 parts by weight of the SiH group-containing compound [B] having two SiH groups in one molecule. Stop material. The SiH group-containing compound [B] having two SiH groups in one molecule is a compound represented by the following formula [II-1], according to any one of claims 1 to 5. Dye-sensitized solar cell encapsulant.

The encapsulant for a dye-sensitized solar cell according to any one of claims 1 to 6, wherein the encapsulant is a LIM (liquid injection molding) molding material comprising the rubber composition.