WO2018180483A1 - Resin composition, sheet, solar cell sealing material, solar cell module, and method for producing sheet for solar cell sealing material - Google Patents

Abstract

The purpose of the present invention is to obtain: a film or sheet which has high transparency, excellent impact resistance (low density) and high strength and is suitable for a solar cell sealing material; a solar cell sealing material comprising the sheet; and a solar cell module comprising the solar cell sealing material. The present invention pertains to a film or sheet containing an ethylene-propylene-α-olefin copolymer [X] which comprises ethylene, propylene and a C5-C20 α-olefin and satisfies the requirement (x-1): a constituent unit (i) derived from ethylene is contained in an amount of 74-92 mol%, a constituent unit (ii) derived from propylene is contained in an amount of 5-16 mol%, and a constituent unit (iii) derived from the C5-C20 α-olefin is contained in an amount of 3-10 mol% (the total amount of the constituent units (i), (ii) and (iii) is 100 mol%.)

Description

Resin composition, sheet, solar cell encapsulant, solar cell module, method for producing solar cell encapsulant sheet

The present invention relates to a resin composition and a sheet, and particularly to a resin composition and a sheet suitable for a solar cell encapsulant.

Solar cells are attracting attention as an energy source that is clean and has no risk of exhaustion. When a solar cell is used outdoors such as a roof portion of a building, it is generally used in the form of a solar cell module.

A solar cell module generally protects both sides of a solar cell element such as silicon, gallium-arsenic, copper-indium-selenium with a solar cell encapsulant, and the encapsulant is composed of an upper transparent protective material and a lower substrate protective material. Protected and packaged. For this reason, as a solar cell sealing material, high transparency is calculated | required also in order to improve electric power generation efficiency. Furthermore, the solar cell module is also required to have heat resistance because the encapsulant may flow and deform as the temperature rises during use. In recent years, as the solar cell element becomes thinner, There is also a need for a sealing material with excellent flexibility.

Patent Document 1 discusses the use of a resin composition containing an ethylene / α-olefin copolymer as a solar cell sealing material. In Examples of Patent Document 1, an ethylene / 1-butene copolymer and an ethylene / 1-octene copolymer are described.

In Patent Document 1, a low-density ethylene / α-olefin copolymer is used to improve transparency.

Patent Document 2 discusses the use of a resin composition containing an ethylene / α-olefin copolymer and an ethylene-functional group-containing monomer copolymer as a solar cell encapsulant. In the example of Patent Document 2, an ethylene / propylene / 1-hexene terpolymer is described.

JP 2011-12246 A WO2012 / 002264

In recent years, high durability has been increasingly demanded for solar cell modules, and therefore, higher glass adhesion strength has been demanded. However, it has been found that the low-density ethylene / α-olefin copolymer described in Patent Document 1 has a low mechanical strength, so that a good glass adhesion strength cannot be obtained.

Further, in the composition described in Patent Document 2, since the amount of double bonds in the polymer molecule is large, fish eyes increase during molding, and the yield of the molded product decreases. It has been found that the ethylene / α-olefin copolymer obtained by the high-pressure method contains a lot of double bonds, so that the fish eye increases during molding and the yield decreases.

In view of the above problems, an object of the present invention is to provide a resin composition capable of suitably obtaining a solar cell encapsulant having high transparency, excellent impact resistance (low density), and high strength, and the composition The sheet | seat containing this, the solar cell sealing material containing this sheet | seat, and the solar cell module containing this solar cell sealing material. Moreover, it is providing the manufacturing method of a sheet | seat suitable for a solar cell sealing material.

As a result of intensive studies to solve the above problems, the present inventors have found that an ethylene / propylene / α-olefin copolymer [X] satisfying a specific composition has high mechanical strength, and the copolymer It has been found that by using a resin composition containing [X], a solar cell encapsulant having high transparency, excellent impact resistance and high strength can be suitably obtained, and the present invention has been completed. .

The present invention relates to a film or sheet containing an ethylene / propylene / α-olefin copolymer [X] that satisfies the following requirement (x-1).

(X-1) an α-olefin having 74 to 92 mol% of the structural unit (i) derived from ethylene, 5 to 16 mol% of the structural unit (ii) derived from propylene, and having 5 to 20 carbon atoms. The derived structural unit (iii) is contained in an amount of 3 to 10 mol% [provided that the total of the structural units (i), (ii) and (iii) is 100 mol%. ].

Since the film or sheet containing the ethylene / propylene / α-olefin copolymer [X] of the present invention has high transparency, excellent heat-resistant mechanical strength, and good flexibility, a solar cell encapsulant, And the solar cell module containing this solar cell sealing material can be obtained suitably.

(Resin composition)
The resin composition of the present invention contains an ethylene / propylene / α-olefin copolymer [X] that satisfies specific requirements. The resin composition preferably contains the copolymer [X] and the organic peroxide [Y] in specific amounts.

[Ethylene / propylene / α-olefin copolymer [X]]
The ethylene / propylene / α-olefin copolymer [X] [hereinafter referred to as “copolymer [X]” in some cases. ] Is a copolymer of ethylene, propylene, and an α-olefin having 5 to 20 carbon atoms and satisfying the following requirement (x-1).

(X-1) 74 to 92 mol%, preferably 76 to 90 mol% of the structural unit (i) derived from ethylene, and 5 to 16 mol%, preferably 7 to 16 mol of the structural unit (ii) derived from propylene. 3 to 10 mol%, preferably 3 to 10 mol% of structural units (iii) derived from an α-olefin having 5 to 20 carbon atoms and more preferably 7 to 15 mol%, more preferably 7 to 14 mol% and more preferably 7 to 14 mol%, 3 to 8 mol%, more preferably 4 to 8 mol%, still more preferably 5 to 8 mol% (provided that the total of structural units (i), (ii) and (iii) is 100 mol%) .

The ethylene / propylene / α-olefin copolymer [X] according to the present invention includes a structural unit derived from ethylene, a structural unit derived from propylene, and a structural unit derived from an α-olefin having 5 to 20 carbon atoms. By including in a range, a film or sheet having high transparency, excellent mechanical strength, and good flexibility can be obtained.

Examples of the α-olefin having 5 to 20 carbon atoms constituting the ethylene / propylene / α-olefin copolymer [X] according to the present invention include 1-pentene, 3-methyl-1-butene, 1-hexene, 4 -Methyl-1-pentene, 3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-eicosene and the like. Of these, 1-hexene, 4-methyl-1-pentene and 1-octene are preferred.

The type of α-olefin constituting the copolymer [X] according to the present invention is clear depending on the type of α-olefin used in the production of the copolymer [X]. The α-olefin content can be quantified using the method described in the Examples.

The ethylene / propylene / α-olefin copolymer [X] according to the present invention preferably has the following requirements (x-2) and (x-3).

The lower limit of the density of the (x-2) according to the density present invention copolymer [X] is, 850kg / m ^3, preferably 855kg / m ^3. The upper limit of the density is 900 kg / m ³ , preferably 895 kg / m ³ , more preferably 890 kg / m ³ . The density of the copolymer [X] is a value measured at 23 ° C. according to ASTM D1505. The density value can be adjusted by selecting the type and content of the comonomer in the copolymer [X].

By using the copolymer [X] having a density in the above range, a film or sheet having better transparency can be obtained.

(X-3) Melt flow rate (MFR)
The MFR of the copolymer [X] according to the present invention has a melt flow rate (MFR, ASTM D1238) at 190 ° C. and a load of 2.16 kg, preferably 0.1 to 50 g / 10 min, more preferably 0. .1 to 40 g / 10 min, more preferably 0.1 to 30 g / 10 min. By using the copolymer [X] having an MFR in the above range, a film or sheet having an excellent balance between moldability and mechanical strength can be obtained.

The ethylene / propylene / α-olefin copolymer [X] according to the present invention preferably further has the following requirement (x-4) and requirement (x-5).

(X-4) Molecular weight distribution (Mw / Mn)
The copolymer [X] according to the present invention has a molecular weight distribution (Mw / Mn) represented by a ratio of the weight average molecular weight (Mw) and the number average molecular weight (Mn), preferably 3.0 or less, More preferably, it is 2.5 or less. Mw and Mn are EPR converted values measured by gel permeation chromatography (GPC). The EPR conversion is as described in the examples. The copolymer [X] having Mw / Mn in the above range is preferable in terms of blocking resistance.

(X-5) Weight average molecular weight (Mw)
The weight average molecular weight (Mw) (EPR conversion) of the copolymer [X] is not particularly limited as long as the effect of the present invention is exhibited, but is preferably 10,000 or more, more preferably 20000 or more, and further preferably 30000 or more.

The ethylene / propylene / α-olefin copolymer [X] according to the present invention more preferably has the following requirement (x-6).

(X-6) Unsaturated bond amount Unsaturated bonds that can be included in the copolymer [X] include the following vinyl type double bonds, vinylidene type double bonds, disubstituted olefin type double bonds and A trisubstituted olefin type double bond is mentioned. The content of these unsaturated bonds can be determined by ¹ H-NMR.

　各式中、＊は水素原子以外の原子との結合手を示す。

In each formula, * indicates a bond with an atom other than a hydrogen atom.

The copolymer [X] has a vinyl type double bond (vinyl group) and a vinylidene type double bond (vinylidene group) per 1000 carbon atoms determined by ¹ H-NMR measurement. A double bond is also referred to as a molecular terminal double bond), a disubstituted olefin type double bond, and a trisubstituted olefin type double bond (in the present invention, these double bonds are also referred to as internal molecular double bonds). The total content of is usually less than 0.40, preferably less than 0.38, and more preferably less than 0.35. When the content of the molecular terminal double bond and the internal double bond in the copolymer [X] is in the above range, the generation of fish eyes during film / sheet formation can be reduced, and the yield is high. By using the copolymer [X], a sheet having excellent mechanical strength or a sheet for solar cell encapsulating material can be suitably obtained.

The copolymer [X] having Mw in the above range has a good balance between film / sheet moldability and mechanical strength.

High transparency and good film / sheet moldability can be obtained by using the copolymer [X] having a density and Mw within the above ranges.

<Method for producing ethylene / propylene / α-olefin copolymer [X]>
The production method of the ethylene / propylene / α-olefin copolymer [X] according to the present invention is not limited as long as it has the above-described properties. For example, copolymer [X] is obtained by copolymerizing ethylene, propylene and an α-olefin having 5 to 20 carbon atoms in the presence of an olefin polymerization catalyst containing catalyst components [A] and [B]. Can be manufactured.

<Catalyst component [A]>
The catalyst component [A] is a metallocene compound represented by the general formula [I].

　式［Ｉ］中、Ｍは遷移金属であり、ｐは遷移金属の原子価を表し、Ｘは、同一でも異なっていてもよく、それぞれ独立に水素原子、ハロゲン原子または炭化水素基であり、Ｒ¹およびＲ²はそれぞれ独立にＭに配位したπ電子共役配位子である。

In the formula [I], M is a transition metal, p represents the valence of the transition metal, X may be the same or different, and each independently represents a hydrogen atom, a halogen atom or a hydrocarbon group, and R ¹ and R ² are each independently a π-electron conjugated ligand coordinated to M.

Examples of the transition metal represented by M include Zr, Ti, Hf, V, Nb, Ta, and Cr. Preferred transition metals are Zr, Ti, or Hf, and more preferred transition metals are Zr or Hf. is there.

Examples of the π-electron conjugated ligand represented by R ¹ and R ² include a η-cyclopentadienyl structure, η-benzene structure, η-cycloheptatrienyl structure, and η-cyclooctatetraene structure. And a particularly preferred ligand is a ligand having a η-cyclopentadienyl structure. Examples of the ligand having an η-cyclopentadienyl structure include a cyclopentadienyl group, an indenyl group, a hydrogenated indenyl group, and a fluorenyl group. These groups are further substituted with halogen atoms; hydrocarbon groups such as alkyl, aryl and aralkyl; oxygen atom-containing groups such as alkoxy groups and aryloxy groups; hydrocarbon-containing silyl groups such as trialkylsilyl groups, and the like. May be.

Examples of the catalyst component [A] include bis (1,3-dimethylcyclopentadienyl) zirconium dichloride, but are not limited to the above compounds. Such a catalyst component [A] is preferably used as a catalyst for olefin polymerization together with the catalyst component [B].

<Catalyst component [B]>
The catalyst component [B] is selected from (b-1) an organoaluminum oxy compound, (b-2) a compound that reacts with the catalyst component [A] to form an ion pair, and (b-3) an organoaluminum compound. At least one compound.

From the viewpoint of the properties of the polymerization activity and the produced olefin polymer, the catalyst component [B]
[1] Only organoaluminum oxy compound (b-1),
[2] Organoaluminum oxy compound (b-1) and organoaluminum compound (b-3),
[3] Compound (b-2) and organoaluminum compound (b-3),
[4] It is preferably used in any embodiment of the organoaluminum oxy compound (b-1) and the compound (b-2).

<< Organic aluminum oxy compound (b-1) >>
As the organoaluminum oxy compound (b-1), a conventionally known aluminoxane can be used as it is. Specifically, the compound represented by general formula [II] and / or general formula [III] is mentioned.

　式［II］または［III］中、Ｒは炭素数１～１０の炭化水素基であり、ｎは２以上の整数である。特にＲがメチル基であるメチルアルミノキサンでｎが３以上、好ましくは１０以上のものが好適に利用される。式［II］または［III］においてＲがメチル基である有機アルミニウムオキシ化合物を、以下「メチルアルミノキサン」と呼ぶ場合がある。

In the formula [II] or [III], R is a hydrocarbon group having 1 to 10 carbon atoms, and n is an integer of 2 or more. In particular, methylaluminoxane in which R is a methyl group and n is 3 or more, preferably 10 or more, is suitably used. In the formula [II] or [III], the organoaluminum oxy compound in which R is a methyl group may be hereinafter referred to as “methylaluminoxane”.

As the organoaluminum oxy compound (b-1), it is also preferable to use a methylaluminoxane analogue that dissolves in a saturated hydrocarbon, and examples thereof include a modified methylaluminoxane represented by the general formula [IV].

　式［IV］中、Ｒは炭素数２～２０の炭化水素基であり、ｍ、ｎは２以上の整数である。

In the formula [IV], R is a hydrocarbon group having 2 to 20 carbon atoms, and m and n are integers of 2 or more.

The modified methylaluminoxane represented by the formula [IV] is prepared using, for example, trimethylaluminum and an alkylaluminum other than trimethylaluminum, and prepared using a trimethylaluminum and triisobutylaluminum from a manufacturer such as Tosoh Finechem, Those in which R is an isobutyl group are commercially produced under trade names such as MMAO and TMAO.

As the organoaluminum oxy compound (b-1), a benzene insoluble organoaluminum oxy compound exemplified in JP-A-2-78687 may be used, which contains boron represented by the general formula [V]. An organoaluminum oxy compound may be used.

　式［Ｖ］中、Ｒ^cは炭素数が１～１０の炭化水素基であり、Ｒ^dは、互いに同一でも異なっていてもよく、水素原子、ハロゲン原子または炭素数が１～１０の炭化水素基である。

In the formula [V], R ^c is a hydrocarbon group having 1 to 10 carbon atoms, R ^d may be the same or different from each other, and is a hydrogen atom, a halogen atom or a hydrocarbon having 1 to 10 carbon atoms. It is a group.

The organoaluminum oxy compound (b-1) may be used alone or in combination of two or more. Note that a slight amount of organoaluminum compound may be mixed in the organoaluminum oxy compound (b-1).

<< Compound capable of reacting with catalyst component [A] to form ion pair (b-2) >>
JP-A-1-501950 discloses a compound (b-2) that reacts with the catalyst component [A] to form an ion pair (hereinafter sometimes abbreviated as “ionic compound (b-2)”). Lewis acids described in JP-A-1-502036, JP-A-3-17905, JP-A-3-179006, JP-A-3-207703, JP-A-3-207704, USP5321106, etc. , Ionic compounds, borane compounds and carborane compounds. Furthermore, examples of the ionic compound (b-2) include heteropoly compounds and isopoly compounds.

The ionic compound (b-2) is preferably a compound represented by the general formula [VI].

　式［VI］中、Ｒ^e+としては、例えば、Ｈ⁺、カルベニウムカチオン、オキソニウムカチオン、アンモニウムカチオン、ホスホニウムカチオン、シクロヘプチルトリエニルカチオン、遷移金属を有するフェロセニウムカチオンが挙げられる。Ｒ^f～Ｒⁱは、互いに同一でも異なっていてもよく、有機基、好ましくはアリール基である。

In the formula [VI], examples of R ^{e +} include H ⁺ , carbenium cation, oxonium cation, ammonium cation, phosphonium cation, cycloheptyltrienyl cation, and ferrocenium cation having a transition metal. R ^f to R ⁱ may be the same as or different from each other, and are organic groups, preferably aryl groups.

Specific examples of the carbenium cation include trisubstituted carbenium cations such as triphenylcarbenium cation, tris (methylphenyl) carbenium cation, and tris (dimethylphenyl) carbenium cation.

Specific examples of ammonium cations include trialkylammonium cations, triethylammonium cations, tri (n-propyl) ammonium cations, triisopropylammonium cations, tri (n-butyl) ammonium cations, triisobutylammonium cations, and the like, N, N-dimethylanilinium cation, N, N-diethylanilinium cation, N, N-2,4,6-pentamethylanilinium cation, N, N-dialkylanilinium cation, diisopropylammonium cation, dicyclohexylammonium Examples thereof include dialkylammonium cations such as cations.

Specific examples of the phosphonium cation include triarylphosphonium cations such as triphenylphosphonium cation, tris (methylphenyl) phosphonium cation, and tris (dimethylphenyl) phosphonium cation.

As R ^{e +} , among them, a carbenium cation and an ammonium cation are preferable, and a triphenylcarbenium cation, an N, N-dimethylanilinium cation, and an N, N-diethylanilinium cation are particularly preferable.

Specific examples of the ionic compound (b-2) which is a carbenium salt include triphenylcarbenium tetraphenylborate, triphenylcarbeniumtetrakis (pentafluorophenyl) borate, triphenylcarbeniumtetrakis (3,5-ditrifluoro). Examples thereof include methylphenyl) borate, tris (4-methylphenyl) carbenium tetrakis (pentafluorophenyl) borate, and tris (3,5-dimethylphenyl) carbeniumtetrakis (pentafluorophenyl) borate.

Specific examples of the ionic compound (b-2) that is an ammonium salt include trialkyl-substituted ammonium salts, N, N-dialkylanilinium salts, and dialkylammonium salts.

Specific examples of the ionic compound (b-2) which is a trialkyl-substituted ammonium salt include triethylammonium tetraphenylborate, tripropylammonium tetraphenylborate, tri (n-butyl) ammonium tetraphenylborate, trimethylammonium tetrakis (p -Tolyl) borate, trimethylammonium tetrakis (o-tolyl) borate, tri (n-butyl) ammonium tetrakis (pentafluorophenyl) borate, triethylammonium tetrakis (pentafluorophenyl) borate, tripropylammonium tetrakis (pentafluorophenyl) borate , Tripropylammonium tetrakis (2,4-dimethylphenyl) borate, tri (n-butyl) ammonium tetrakis (3,5-dimethylphenyl) borate, tri (n-butyl) Ammonium tetrakis (4-trifluoromethylphenyl) borate, tri (n-butyl) ammonium tetrakis (3,5-ditrifluoromethylphenyl) borate, tri (n-butyl) ammonium tetrakis (o-tolyl) borate, dioctadecylmethyl Ammonium tetraphenylborate, dioctadecylmethylammonium tetrakis (p-tolyl) borate, dioctadecylmethylammonium tetrakis (o-tolyl) borate, dioctadecylmethylammonium tetrakis (pentafluorophenyl) borate, dioctadecylmethylammonium tetrakis (2,4 -Dimethylphenyl) borate, dioctadecylmethylammonium tetrakis (3,5-dimethylphenyl) borate, dioctadecylmethylammonium tetrakis (4-trifluoromethylphenyl) borate Dioctadecylmethylammonium tetrakis (3,5-ditrifluoromethylphenyl) borate include dioctadecyl methyl ammonium.

Specific examples of the ionic compound (b-2) that is an N, N-dialkylanilinium salt include N, N-dimethylanilinium tetraphenylborate, N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, N, N-dimethylanilinium tetrakis (3,5-ditrifluoromethylphenyl) borate, N, N-diethylanilinium tetraphenylborate, N, N-diethylanilinium tetrakis (pentafluorophenyl) borate, N, N- Diethylanilinium tetrakis (3,5-ditrifluoromethylphenyl) borate, N, N-2,4,6-pentamethylanilinium tetraphenylborate, N, N-2,4,6-pentamethylanilinium tetrakis ( Pentafluorophenyl) borate.

Specific examples of the dialkylammonium salt include di (1-propyl) ammonium tetrakis (pentafluorophenyl) borate and dicyclohexylammonium tetraphenylborate.

As the other ionic compound (b-2), an ionic compound disclosed by the present applicant (Japanese Patent Laid-Open No. 2004-51676) can also be used without limitation.

The ionic compound (b-2) may be used alone or in combination of two or more.

<< Organic aluminum compound (b-3) >>
Examples of the organoaluminum compound (b-3) include an organoaluminum compound represented by the general formula [VII] and a complex alkylated product of a group 1 metal of the periodic table represented by the general formula [VIII] and aluminum. It is done.

R ^a _m Al (OR ^b ) _n H _p X _q ... [VII]
In the formula [VII], R ^a and R ^b may be the same or different from each other, and are each a hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms, X is a halogen atom, m is 0 <m ≦ 3, n is 0 ≦ n <3, p is 0 ≦ p <3, q is a number of 0 ≦ q <3, and m + n + p + q = 3.

Specific examples of the organoaluminum compound represented by the formula [VII] include tri-n-alkylaluminums such as trimethylaluminum, triethylaluminum, tri-n-butylaluminum, trihexylaluminum and trioctylaluminum; triisopropylaluminum, triisobutyl Tri-branched alkyl aluminums such as aluminum, tri-sec-butylaluminum, tri-tert-butylaluminum, tri-2-methylbutylaluminum, tri-3-methylhexylaluminum, tri-2-ethylhexylaluminum; tricyclohexylaluminum, tricyclooctylaluminum, etc. Tricycloalkylaluminum; triarylaluminum such as triphenylaluminum and tolylylaluminum; diisopropylaluminum hydra Id, dialkylaluminum hydride such as diisobutylaluminum hydride; formula _{(iC 4 H 9) x Al} y (C 5 H 10) z ( wherein, x, y, z are each a positive number, is z ≦ 2x ) Alkenyl aluminum such as isoprenyl aluminum, etc .; Alkyl aluminum alkoxide such as isobutylaluminum methoxide and isobutylaluminum ethoxide; Dialkylaluminum alkoxide such as dimethylaluminum methoxide, diethylaluminum ethoxide and dibutylaluminum butoxide; formula R ^a _2.5 Al (OR ^b) partially alkoxylated alkyl aluminum having an average composition represented by _0.5 or the like; aluminum sesqui ethoxide, alkyl aluminum sesqui alkoxides such as butyl sesquichloride butoxide; Alkyl aluminum aryloxides such as ethylaluminum phenoxide and diethylaluminum (2,6-di-t-butyl-4-methylphenoxide); dimethylaluminum chloride, diethylaluminum chloride, dibutylaluminum chloride, diethylaluminum bromide, diisobutylaluminum chloride, etc. Dialkylaluminum halides; alkylaluminum sesquihalides such as ethylaluminum sesquichloride, butylaluminum sesquichloride, ethylaluminum sesquibromide; partially halogenated alkylaluminums such as alkylaluminum dihalides such as ethylaluminum dichloride; diethylaluminum hydride Dialkylaluminum hydrides such as dibutylaluminum hydride; Other partially hydrogenated alkylaluminums such as alkylaluminum dihydrides such as aluminum dihydride, propylaluminum dihydride; partially alkoxylated such as ethylaluminum ethoxychloride, butylaluminum butoxycycloride, ethylaluminum ethoxybromide and the like A halogenated alkylaluminum is mentioned.

M ² AlR ^a ₄ … [VIII]
In the formula [VIII], M ² is Li, Na or K, and R ^a is a hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms. Examples of such a compound include LiAl (C ₂ H ₅ ) ₄ and LiAl (C ₇ H ₁₅ ) ₄ .

A compound similar to the compound represented by the general formula [VII] can also be used, and examples thereof include an organoaluminum compound in which two or more aluminum compounds are bonded through a nitrogen atom. Specific examples of such a compound include (C ₂ H ₅ ) ₂ AlN (C ₂ H ₅ ) Al (C ₂ H ₅ ) ₂ .

As the organoaluminum compound (b-3), trimethylaluminum and triisobutylaluminum are preferably used from the viewpoint of easy availability.

The organoaluminum compound (b-3) may be used alone or in combination of two or more.

<Polymerization conditions>
The copolymer [X] can be suitably produced by copolymerizing ethylene, propylene and an α-olefin having 5 to 20 carbon atoms in the presence of the above-mentioned olefin polymerization catalyst. The copolymerization is not particularly limited, but it is preferably performed by solution polymerization in the presence of an olefin polymerization catalyst at a temperature of 50 to 180 ° C. in the presence of a solvent.

In the polymerization, the method of using each component and the order of addition are arbitrarily selected. For example, a method of adding the catalyst component [A] and the catalyst component [B] to the polymerization vessel in an arbitrary order can be exemplified. . In the said method, two or more of each catalyst component may be contacted previously.

In the case of producing copolymer [X] by copolymerizing ethylene, propylene and α-olefin using an olefin polymerization catalyst, the catalyst component [A] is usually 10 ⁻⁹ to 1 liter of reaction volume. It can be used in an amount of 10 ⁻¹ mol, preferably 10 ⁻⁸ to 10 ⁻² mol.

The component (b-1) has a molar ratio [(b-1) / M] of the component (b-1) to all transition metal atoms (M) in the component [A] of usually 1 to 10,000, preferably 10 It can be used in an amount of ˜5000. Component (b-2) has a molar ratio [(b-2) / M] of component (b-2) to all transition metal atoms (M) in component [A], usually 0.5 to 50, The amount can be preferably 1 to 20. Component (b-3) can be used in an amount of usually 0 to 5 mmol, preferably about 0 to 2 mmol, per liter of polymerization volume.

The charged molar ratio of ethylene, propylene and α-olefin may be appropriately selected according to the characteristics of the target copolymer [X], and is not particularly limited. Usually ethylene: propylene + α-olefin = 10: 90 to 99.9: 0.1, preferably ethylene: propylene + α-olefin = 30: 70 to 99.9: 0.1, more preferably ethylene: propylene + α-olefin = 50:50 to 95.0: 5.0.

“Solution polymerization” preferably employed in the production of the copolymer [X] is a general term for a method of performing polymerization in a state where the polymer is dissolved in a hydrocarbon solvent inert to the copolymerization reaction. The polymerization temperature in the solution polymerization is usually 50 to 180 ° C., preferably 70 to 150 ° C., more preferably 90 to 130 ° C.

In solution polymerization, the polymerization temperature is preferably in the above range from the viewpoint of polymerization activity and heat removal from the polymerization heat. Specifically, it is preferable from the viewpoint of productivity when it is at least the lower limit of the above range; it is preferable from the viewpoint of blocking resistance that it is difficult to form a branch in the polymer when it is not more than the upper limit of the above range.

The polymerization pressure is usually from normal pressure to 10 MPa gauge pressure, preferably from normal pressure to 8 MPa gauge pressure, and the copolymerization can be carried out by any of batch, semi-continuous and continuous methods. The reaction time (average residence time when the copolymerization reaction is carried out in a continuous manner) varies depending on conditions such as the catalyst concentration and polymerization temperature, and can be appropriately selected, but is usually 1 minute to 3 hours, preferably 10 minutes to 2.5 hours.

Polymerization can be performed in two or more stages with different reaction conditions.

The molecular weight of the obtained copolymer [X] can also be adjusted by changing the hydrogen concentration or polymerization temperature in the polymerization system. Furthermore, it can also adjust with the quantity of the catalyst component [B] to be used. When hydrogen is added to the polymerization system, the amount is suitably about 0.001 to 5,000 NL per 1 kg of the produced copolymer [X]. Further, the density of the obtained copolymer [X] can be adjusted by the feed amount of propylene and α-olefin.

The solvent used in the solution polymerization is usually an inert hydrocarbon solvent, preferably a saturated hydrocarbon having a boiling point of 50 to 200 ° C. under normal pressure. Specific examples include aliphatic hydrocarbons such as pentane, hexane, heptane, octane, decane, dodecane, and kerosene; and alicyclic hydrocarbons such as cyclopentane, cyclohexane, and methylcyclopentane. In addition, aromatic hydrocarbons such as benzene, toluene and xylene; halogenated hydrocarbons such as ethylene chloride, chlorobenzene and dichloromethane are also included in the category of “inert hydrocarbon solvents” and their use is not limited.

In order to suppress variations in physical property values, the copolymer [X] obtained by the polymerization reaction and other components added as desired may be melted by any method, kneaded, granulated, etc. preferable.

(Resin composition)
The resin composition according to the present invention is a composition containing the ethylene / propylene / α-olefin copolymer [X], and preferably contains a specific amount of the organic peroxide [Y].

(Organic peroxide [Y])
The organic peroxide [Y] used in the present invention is a film or sheet made of the copolymer [X], or a solar cell encapsulant sheet, and a crosslinking reaction during solar cell module laminate molding. Used as a radical initiator. A film or sheet having high transparency, excellent heat resistance, high mechanical strength, and good flexibility by crosslinking the copolymer [X] with an organic peroxide [Y] or a sheet for solar cell encapsulant Preferably obtained.

The organic peroxide [Y] is not particularly limited as long as it can crosslink the copolymer [X]. For example, film or sheet moldability, productivity in extrusion molding, and solar cell The organic peroxide (Y) having a half-life temperature of 1 minute of the organic peroxide (Y) in the range of 100 to 190 ° C. is preferable from the balance of the crosslinking rate at the time of module lamination molding. More preferably, the 1-minute half-life temperature is 100 to 180 ° C.

When the one-minute half-life temperature of the organic peroxide [Y] is less than 100 ° C., gel is generated in the sheet for solar cell encapsulant obtained from the resin composition at the time of extrusion sheet molding, and the torque of the extruder increases. However, sheet forming may be difficult. Even if a sheet is obtained, unevenness may occur on the surface of the sheet due to the gel generated in the extruder, and the appearance may deteriorate. In addition, when a voltage is applied, cracks are generated around the gel within the sheet, and the dielectric breakdown resistance is reduced. Furthermore, moisture permeation at the gel object interface is likely to occur and moisture permeability is reduced. Moreover, since unevenness | corrugation generate | occur | produces on the sheet | seat surface, at the time of the lamination process of a solar cell module, adhesiveness with glass, a thin film electrode, and a back sheet deteriorates, and since adhesion becomes inadequate, adhesiveness also falls. If the extrusion temperature of extrusion sheet molding is lowered to 90 ° C. or lower, molding is possible, but productivity is greatly reduced. When the one-minute half-life temperature of the organic peroxide [Y] is over 180 ° C., the crosslinking rate at the time of laminate molding of the solar cell module is slow, and the productivity of the solar cell module is greatly reduced. Moreover, the heat resistance and adhesiveness of the solar cell encapsulant sheet are reduced.

The amount of the organic peroxide [Y] is usually 0.1 to 3 parts by weight, preferably 0.2 to 3 parts by weight, and more preferably 0.2 parts by weight with respect to 100 parts by weight of the copolymer [X]. ~ 2.5 parts by weight. When the organic peroxide [Y] is less than 0.1 part by weight, the crosslinking characteristics at the time of laminate molding of the solar cell module become insufficient, and the heat resistance and the glass adhesiveness are lowered. When the organic peroxide [Y] is more than 3 parts by weight, gelation occurs when a sheet or a solar cell encapsulant sheet is obtained from the resin composition with an extruder or the like, and the torque of the extruder is increased. Molding may be difficult. Even if a sheet is obtained, unevenness may occur on the surface of the sheet due to the gel generated in the extruder, and the appearance may deteriorate. In addition, when a voltage is applied, cracks are generated around the gel within the sheet, and the dielectric breakdown resistance is reduced. Furthermore, moisture permeability at the gel object interface is likely to occur, and moisture permeability is reduced. Moreover, since unevenness | corrugation generate | occur | produces on the sheet | seat surface, at the time of the lamination process of a solar cell module, adhesiveness with glass, a thin film electrode, and a back sheet deteriorates, and since adhesion becomes inadequate, adhesiveness also falls.

Although known organic peroxides can be used, the organic peroxide [Y] described above preferably has a one-minute half-life temperature in the range of 100 to 180 ° C.

Specific examples include dilauroyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, dibenzoyl peroxide, cyclohexanone peroxide, di-t-butyl perphthalate, t- Butyl hydroperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, t-amylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate , T-butylperoxyisobutyrate, t-butylperoxymaleic acid, 1,1-di (t-amylperoxy) -3,3,5-trimethylcyclohexane, 1,1-di (t-amylper) Oxy) cyclohexane, t-amyl peroxy isononanoate, t-amyl peroxy normal octoate, 1,1-di (t-butyl pero Xyl) -3,3,5-trimethylcyclohexane, 1,1-di (t-butylperoxy) cyclohexane, t-butylperoxyisopropyl carbonate, t-butylperoxy-2-ethylhexyl carbonate, 2,5-dimethyl -2,5-di (benzoylperoxy) hexane, t-amyl-peroxybenzoate, t-butylperoxyacetate, t-butylperoxyisononanoate, t-butylperoxybenzoate, 2,2-di ( Butylperoxy) butane, n-butyl-4,4-di (t-butylperoxy) petitate, methyl ethyl ketone peroxide, ethyl 3,3-di (t-butylperoxy) butyrate, dicumyl peroxide, t- Butyl cumyl peroxide, t-butyl peroxybenzoate, acetylacetone peroxide Etc. Preferably, dilauroyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, t-butylperoxyisopropyl carbonate, t-butylperoxybenzoate, t-butylperoxyacetate, Examples thereof include t-butyl peroxyisononanoate, t-butyl peroxy-2-ethylhexyl carbonate, t-butyl peroxybenzoate and the like.

The organic peroxide [Y] may be used singly or in appropriate combination of two or more.

(Ethylenically unsaturated silane compound (C))
If necessary, the resin composition of the present invention contains an ethylenically unsaturated silane compound (C), which has good crosslinkability and excellent heat resistance, or a sheet for solar cell encapsulant. It is preferable from the point which can be obtained.

As the ethylenically unsaturated silane compound (C), conventionally known compounds can be used, and there is no particular limitation. Specifically, vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris (β-methoxyethoxysilane), γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane Etc. can be used. Preferred examples include γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and γ-methacryloxypropyltrimethoxysilane, which have good adhesion. The ethylenically unsaturated silane compound (C) may be used alone or in a suitable mixture of two or more.

The resin composition of the present invention comprises 0.1 to 3 parts by weight of organic peroxide [Y] and 0.1 to 3 parts of ethylenically unsaturated silane compound (C) with respect to 100 parts by weight of copolymer [X]. A preferred embodiment contains 5 parts by weight. More preferably, the organic peroxide [Y] is 0.2 to 3 parts by weight and the ethylenically unsaturated silane compound (C) is 0.1 to 4 parts by weight with respect to 100 parts by weight of the copolymer [X]. More preferably, the organic peroxide [Y] is 0.2 to 2.5 parts by weight and the ethylenically unsaturated silane compound (C) is 0 with respect to 100 parts by weight of the copolymer [X]. 1 to 3 parts by weight. The resin composition in the above range has good adhesion to glass and a good balance between the cost and performance of the resin composition. Further, when the sheet is formed, the surface of the sheet is not uneven due to the gel material generated in the extruder, and the appearance is improved. Moreover, even when a voltage is applied, no cracks occur and the dielectric breakdown resistance is improved. Furthermore, moisture permeability is less likely to occur. In addition, adhesion and adhesion to the glass, thin film electrode, and back sheet are also improved when the solar cell module is laminated.

When the organic peroxide [Y] is less than 0.1 parts by weight, the crosslinking characteristics at the time of laminate molding of the solar cell module become insufficient, and the heat resistance and the glass adhesiveness are lowered. When the organic peroxide [Y] is more than 3 parts by weight, gelation occurs when a sheet or a solar cell encapsulant sheet is obtained from the resin composition with an extruder or the like, and the torque of the extruder is increased. Molding may be difficult. Even if a sheet is obtained, the gel material generated in the extruder may cause unevenness on the surface of the sheet, which may deteriorate the appearance. In addition, when a voltage is applied, cracks are generated around the gel within the sheet, and the dielectric breakdown resistance is reduced. Furthermore, moisture permeability at the gel object interface is likely to occur, and moisture permeability is reduced. Moreover, since unevenness | corrugation generate | occur | produces on the sheet | seat surface, at the time of the lamination process of a solar cell module, adhesiveness with glass, a thin film electrode, and a back sheet deteriorates, and since adhesion becomes inadequate, adhesiveness also falls.

(Ultraviolet absorber (D), light stabilizer (E), heat stabilizer (F))
The resin composition of the present invention preferably contains at least one additive selected from an ultraviolet absorber (D), a light stabilizer (E) and a heat resistance stabilizer (F). The amount of the additive is preferably 0.005 to 5 parts by weight with respect to 100 parts by weight of the copolymer [X]. Furthermore, it is preferable to contain at least two types of additives selected from the above three types, and it is particularly preferable that all the three types are included. When the amount of the additive is within the above range, the effect of improving the resistance to high temperature and humidity, heat cycle resistance, weather resistance stability and heat stability is sufficiently ensured, and the transparency of the resin composition is ensured. And glass, a back sheet, a thin film electrode, and a decrease in adhesiveness with aluminum can be prevented, which is preferable.

Specific examples of the ultraviolet absorber (D) include 2-hydroxy-4-normal-octyloxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2--2-dihydroxy-4-methoxybenzophenone, 2-hydroxy- Benzophenone series such as 4-methoxy-4-carboxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2- (2-hydroxy-3,5-di-t-butylphenyl) benzotriazole, 2- (2 Benzotrializoles such as -hydroxy-5-methylphenyl) benzotriazole and salicylic acid esters such as phenylsulcylate and p-octylphenylsulcylate are used.

Examples of the light stabilizer (E) include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, poly [{6- (1,1,3,3-tetramethylbutyl) amino-1 , 3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) ) Imino}] and other hindered amine-based and hindered piperidine-based compounds are preferably used.

Specific examples of the heat stabilizer (F) include tris (2,4-di-tert-butylphenyl) phosphite and bis [2,4-bis (1,1-dimethylethyl) -6-methylphenyl. ] Ethyl ester phosphorous acid, tetrakis (2,4-di-tert-butylphenyl) [1,1-biphenyl] -4,4'-diylbisphosphonite, and bis (2,4-di-tert -Butylphenyl) pentaerythritol diphosphite and other phosphite heat stabilizers, lactones such as the reaction product of 3-hydroxy-5,7-di-tert-butyl-furan-2-one and o-xylene Heat-resistant stabilizer, 3,3 ′, 3 ″, 5,5 ′, 5 ″ -hexa-tert-butyl-a, a ′, a ″-(methylene-2,4,6-triyl) tri-p-cresol 1,3,5- Limethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxyphenyl) benzylbenzene, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) Propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, thiodiethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], etc. Hindered phenol heat stabilizers, sulfur heat stabilizers, amine heat stabilizers, etc. These may be used alone or in combination of two or more.

Of these, phosphite heat stabilizers and hindered phenol heat stabilizers are preferred.

(Other additives)
The resin composition of the present invention can appropriately contain various components other than the components detailed above in a range not impairing the object of the present invention.

For example, various polyolefins other than the copolymer [X], for example, ethylene / α-olefin copolymers having a density lower than 850 kg / m ³ , styrene or ethylene block copolymers, propylene (co) polymers Examples include coalescence. These are not particularly limited as long as the effects of the present invention are exerted with respect to 100 parts by weight of the copolymer [X], but are usually 0.0001 to 50 parts by weight, preferably 0.001 to 40 parts by weight. Part. Also, from various resins other than polyolefin, various rubbers, antioxidants, plasticizers, fillers, pigments, dyes, antistatic agents, antibacterial agents, antifungal agents, flame retardants, crosslinking aids (G), dispersants, etc. One kind or two or more kinds of additives selected can be appropriately contained, but are not limited thereto.

In particular, in the crosslinking aid (G), the blending amount is 0.01 to 5 parts by weight with respect to 100 parts by weight of the copolymer [X], so that an appropriate crosslinking structure can be obtained. It is preferable because heat resistance, mechanical properties, and adhesiveness can be improved.

As the crosslinking aid (G), conventionally known ones generally used for olefin resins can be used. Such a crosslinking aid (G) is a compound having two or more double bonds in the molecule, and specifically includes t-butyl acrylate, lauryl acrylate, cetyl acrylate, stearyl acrylate, 2-methoxyethyl. Monoacrylate such as acrylate, ethyl carbitol acrylate, methoxytripropylene glycol acrylate, t-butyl methacrylate, lauryl methacrylate, cetyl methacrylate, stearyl methacrylate, methoxyethylene glycol methacrylate, monomethacrylate such as methoxypolyethylene glycol methacrylate, 1,4-butane Diol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, neopentyl glycol diacrylate Diacrylate, diethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, etc., 1,3-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate 1,9-nonanediol dimethacrylate neopentyl glycol dimethacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate and other dimethacrylates, trimethylolpropane triacrylate, tetramethylolmethane triacrylate , Pentaerythritol triacryl Triacrylates such as trimethol, trimethacrylates such as trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, tetraacrylates such as pentaerythritol tetraacrylate and tetramethylolmethane tetraacrylate, divinyl aromatics such as divinylbenzene and di-i-propenylbenzene Family compounds, cyanurates such as triallyl cyanurate and triallyl isocyanurate, triallyl compounds such as diallyl phthalate and diallyl compounds, oximes such as p-quinonedioxime, pp'-dibenzoylquinonedioxime, phenylmaleimide, etc. Maleimide is mentioned. Of these crosslinking aids (G), diacrylate, dimethacrylate, and divinyl aromatic compounds are more preferable.

[Production method of resin composition and film or sheet]
The resin composition of the present invention can be produced by employing any known method. For example, a predetermined amount of copolymer [X] and, if necessary, a predetermined amount of organic peroxide [Y], an ethylenically unsaturated silane compound (C), an ultraviolet absorber (D), a light stabilizer. (E), heat stabilizer (F), etc. are mixed by various known methods, for example, a Henschel mixer, V-blender, ribbon blender, tumbler blender, or the like, or after mixing, a single-screw extruder or a twin-screw extruder It can be produced by a method of granulating or pulverizing after melt-kneading usually at 60 to 140 ° C., preferably 80 to 120 ° C. with a kneader, Banbury mixer or the like.

Film or sheet comprising the resin composition according to the present invention [hereinafter sometimes referred to as “sheet”. ] Can be obtained by a known method, for example, melt extrusion molding or press molding of powders, granules and pellets obtained from the resin composition of the present invention.

[Solar cell encapsulant]
The resin composition of the present invention, a sheet comprising the resin composition, and a film or sheet obtained by crosslinking the sheet comprising the resin composition (hereinafter sometimes abbreviated as “crosslinked sheet”) are glass, back. Excellent balance of adhesion with sheet, thin film electrode, aluminum, heat resistance, moldability and cross-linking properties, and also excellent weather resistance, volume resistivity, electrical insulation, moisture permeability, electrode corrosion, and process stability Therefore, it is suitably used as a solar cell sealing material for a conventionally known solar cell module.

[Sheet and sheet for solar cell encapsulant]
The sheet | seat for solar cell sealing materials whose resin composition of this invention is a sheet form is also one of preferable embodiment of this invention. Moreover, the composite sheet | seat for solar cell sealing materials which has at least 1 layer of the sheet | seat containing the resin composition of this invention can also be used suitably for a solar cell sealing material.

The thickness of the layer of the film or sheet according to the present invention and the sheet for solar cell encapsulant is usually 0.01 to 2 mm, preferably 0.01 to 1.5 mm, more preferably 0.1 to 1.2 mm. The thickness is 01 to 1 mm, more preferably 0.01 to 0.5 mm, more preferably 0.01 to 0.3 mm, and most preferably m 0.01 to 0.2 mm. When the thickness is within this range, damage to the glass, solar battery cell, thin film electrode, etc. in the laminating step can be suppressed, and a high amount of photovoltaic power can be obtained by ensuring sufficient light transmittance, And since it can laminate-mold the solar cell module at low temperature, it is preferable.

There are no particular restrictions on the method of forming the sheet according to the present invention and the sheet of the solar cell encapsulant, but various known forming methods (cast molding, extrusion sheet molding, inflation molding, injection molding, compression molding, calendar molding, etc. ) Can be adopted. For example, copolymer [X] and, if necessary, organic peroxide [Y], ethylenically unsaturated silane compound (C), ultraviolet absorber (D), light stabilizer (E) in an extruder. ), Heat-stabilizing agent (F), and other additives are melt kneaded, and extrusion sheet molding is performed to obtain a solar cell encapsulant in the form of a sheet. As the extrusion temperature range, the extrusion temperature is usually 100 to 150 ° C. When the extrusion temperature is less than 100 ° C., the productivity of the sheet decreases. If the extrusion temperature exceeds 150 ° C., gelation may occur when a sheet is obtained from the resin composition with an extruder or the like, and the torque of the extruder may increase to make sheet molding difficult. Even if a sheet is obtained, unevenness may occur on the surface of the sheet due to the gel generated in the extruder, and the appearance may deteriorate. In addition, when a voltage is applied, cracks are generated around the gel within the sheet, and the dielectric breakdown resistance is reduced. Furthermore, moisture permeability at the gel object interface is likely to occur, and moisture permeability is reduced. Moreover, since unevenness | corrugation generate | occur | produces on the sheet | seat surface, at the time of the lamination process of a solar cell module, adhesiveness with glass, a thin film electrode, and a back sheet deteriorates, and since adhesion becomes inadequate, adhesiveness also falls.

In addition, the surface of the sheet can be embossed, and the surface of this layer can be decorated by embossing to prevent blocking between the sealing sheets or between the sealing sheet and other sheets. Furthermore, the embossing is preferable because it becomes a cushion for the solar cell element or the like at the time of laminating and prevents the breakage.

Further, the sheet can be used as a solar cell encapsulant in a single wafer form cut to fit the solar cell module size or a roll form that can be cut to fit the size just before producing the solar cell module. .

The solar cell encapsulant which is a preferred embodiment of the present invention may have at least one layer composed of the solar cell encapsulant sheet of the present invention. Therefore, the number of layers of the solar cell encapsulant sheet of the present invention may be one, or two or more. From the viewpoint of simplifying the structure and reducing the cost, and from the viewpoint of effectively utilizing light by minimizing interface reflection between layers, a single layer is preferable.

The solar cell encapsulant which is a preferred embodiment of the present invention may be composed of only a layer composed of the sheet for solar cell encapsulant of the present invention, and contains the sheet for solar cell encapsulant of the present invention. A layer other than the layer (hereinafter also referred to as “other layer”) may be included.

As examples of other layers, if classified according to the purpose, a hard coat layer, an adhesive layer, an antireflection layer, a gas barrier layer, an antifouling layer and the like for protecting the front surface or the back surface can be provided. If classified by material, layer made of UV curable resin, layer made of thermosetting resin, layer made of polyolefin resin, layer made of carboxylic acid modified polyolefin resin, layer made of fluorine-containing resin, cyclic olefin (co) A layer made of a polymer, a layer made of an inorganic compound, or the like can be provided.

The positional relationship between the layer made of the solar cell encapsulant sheet of the present invention and the other layers is not particularly limited, and a preferable layer configuration is appropriately selected depending on the purpose of the invention. That is, the other layer may be provided between two or more layers made of the solar cell encapsulant sheet of the present invention, or may be provided in the outermost layer of the solar cell encapsulant sheet. , It may be provided at other locations. Other layers may be provided only on one side of the layer made of the solar cell encapsulant sheet of the present invention, or other layers may be provided on both sides. There is no restriction | limiting in particular in the number of layers of another layer, Arbitrary number of other layers can be provided and it is not necessary to provide another layer.

From the viewpoint of simplifying the structure and reducing the cost, and from the viewpoint of effectively utilizing light by minimizing interface reflection, no other layers are provided, and only the layer made of the sheet for solar cell encapsulant of the present invention. Thus, a solar cell encapsulant may be produced, and if there are other layers necessary or useful in relation to the purpose, such other layers may be provided as appropriate.

There is no particular limitation on the method of laminating the layer composed of the sheet for solar cell encapsulant of the present invention and the other layer when other layers are provided, but known melt extrusion such as cast molding machine, extrusion sheet molding machine, etc. A method of obtaining a laminate by co-extrusion using a machine, or a method of obtaining a laminate by melting or heating and laminating the other layer on one previously formed layer is preferred. In addition, suitable adhesives (for example, maleic anhydride-modified polyolefin resin (for example, Admer (registered trademark) manufactured by Mitsui Chemicals, Inc., Modic (registered trademark) manufactured by Mitsubishi Chemical), unsaturated polyolefin, etc.) Acrylic adhesives such as low (non-) crystalline soft polymers, ethylene / acrylic acid ester / maleic anhydride terpolymers (for example, Bondine (registered trademark) manufactured by Sumika Sea-Dief Chemical), ethylene / Vinyl acetate copolymer or adhesive resin composition containing these) may be laminated by a dry laminating method or a heat laminating method. As the adhesive, one having a heat resistance of usually about 120 ° C. to 150 ° C. is preferably used, and a polyester-based or polyurethane-based adhesive is exemplified as a suitable one. Moreover, in order to improve the adhesiveness of both layers, for example, a silane coupling treatment, a titanium coupling treatment, a corona treatment, a plasma treatment, or the like may be used.

The sheet for solar cell encapsulant (non-crosslinked sheet) of the present invention has an internal haze of usually 60% or less when measured with a 0.5 mm thick sample obtained by extrusion sheet molding of the resin composition of the present invention. Preferably, it is desirable to be in the range of 50% or less.

The solar cell encapsulant sheet (non-crosslinked sheet) of the present invention has a light transmittance (wavelength of 400 to 700 nm) measured with a 0.3 mm thick sample obtained by extrusion sheet molding of the resin composition of the present invention. Is usually in the range of 85% or more, preferably in the range of 88% to 100%, more preferably in the range of 90 to 100%.

The solar cell encapsulant comprising the solar cell encapsulant sheet made of the resin composition of the present invention as a part thereof is obtained, for example, by taking 1 g of the encapsulant sheet sample from the solar cell module, and boiling xylene. Soxhlet extraction is performed for 10 hours, filtered through a 30 mesh stainless steel mesh, the mesh is dried under reduced pressure at 110 ° C. for 8 hours, and calculated from the residual amount on the mesh, the gel fraction is 70 to 95%, preferably Is in the range of 70-90%. When the gel fraction is less than 70%, the heat resistance of the solar cell encapsulant is insufficient, a constant temperature and humidity test at 85 ° C. × 85% Rh, and a high intensity xenon irradiation test at a black panel temperature of 83 ° C. , The adhesiveness tends to decrease in a heat cycle test or a heat resistance test at −40 ° C. to 90 ° C. When the gel fraction is over 95%, the flexibility of the solar cell encapsulant is reduced, and the temperature followability in the heat cycle test at −40 ° C. to 90 ° C. is reduced. There is.

[Solar cell module]
The solar cell encapsulant of the present invention and the solar cell encapsulant sheet which is a preferred embodiment of the present invention have excellent characteristics as described above. Therefore, the solar cell module obtained by using such a solar cell encapsulant or solar cell encapsulant sheet can utilize the effects of the present invention, and is one of the preferred embodiments of the present invention. is there.

Examples of the solar cell module include a crystalline solar cell module in which solar cell elements usually formed of polycrystalline silicon or the like are sandwiched and stacked between solar cell encapsulant sheets, and both front and back surfaces are covered with protective sheets. . That is, a typical solar cell module includes a solar cell module protective sheet (surface protective sheet) / solar cell encapsulant sheet / solar cell element / solar cell encapsulant sheet / solar cell module protective sheet (back surface protection). Sheet). However, the solar cell module which is one of the preferred embodiments of the present invention is not limited to the above-described configuration, and a part of each of the above layers is appropriately omitted as long as the object of the present invention is not impaired. Layers other than the above can be provided as appropriate. Typically, an adhesive layer, a shock absorbing layer, a coating layer, an antireflection layer, a back surface rereflection layer, a light diffusion layer, and the like can be provided, but not limited thereto. There is no particular limitation on the positions where these layers are provided, and the layers can be provided at appropriate positions in consideration of the purpose of providing such layers and the characteristics of such layers.

Furthermore, for example, a solar cell in which amorphous silicon formed by chemical vapor deposition (CVD) from silane gas is formed on a glass or film substrate with a thin silicon film of several μm, and an electrode such as silver is sputtered as necessary. A thin film (amorphous) solar cell module in which elements are covered in the order of a solar cell encapsulant sheet and a solar cell module protective sheet (back surface protective sheet) is also a preferred embodiment of the present invention.

In addition, as other solar cell modules, solar cell modules using silicon for solar cells, hybrid type (HIT type) solar cell modules in which crystalline silicon and amorphous silicon are laminated, and multiple silicon layers having different absorption wavelength ranges are laminated. Junction type (tandem type) solar cell module, spherical silicon type solar cell module combining innumerable spherical silicon particles (diameter about 1mm) and concave mirror of 2 to 3mm in diameter (also serving as electrode) to increase the light collecting ability, conventional pin Examples include a field effect solar cell module having a structure in which the role of an amorphous silicon p-type window layer having a junction structure is replaced with an inversion layer induced by a field effect from an insulated transparent electrode. Also, a GaAs-based solar battery module using single-crystal GaAs for solar cells, and a light-absorbing layer material called a chalcopyrite system made of Cu, In, Ga, Al, Se, S, etc. instead of silicon CIS or CIGS (chalcopyrite) solar cell module using I-III-VI group compound as a solar cell, CdTe-CdS solar cell using a Cd compound thin film as a solar cell, Cu ₂ ZnSnS ₄ (CZTS) ) Solar cell module and the like. The solar cell encapsulant or solar cell encapsulant sheet of the present invention can be suitably used for all these solar cell modules. In particular, since the solar cell module of the present invention is excellent in hygroscopicity, it can be suitably used as a thin-film solar cell module that is vulnerable to moisture penetration.

(Protective sheet for solar cell module (surface protective sheet))
The surface protective sheet preferably used in the solar cell module which is a preferred embodiment of the present invention is not particularly limited, but is located on the outermost layer of the solar cell module, so that it has weather resistance, water repellency, stain resistance, and mechanical strength. First, it is preferable that the solar cell module has performance for ensuring long-term reliability in outdoor exposure. Moreover, in order to utilize sunlight effectively, it is preferable that it is a highly transparent sheet | seat with a small optical loss.

Examples of the material for the surface protective sheet suitably used for the solar cell module include a resin film made of a polyester resin, a fluorine resin, an acrylic resin, a cyclic olefin (co) polymer, an ethylene-vinyl acetate copolymer, glass, and the like. Examples include substrates.

Particularly suitable as the resin film is a polyester resin excellent in transparency, strength, cost, etc., particularly a polyethylene terephthalate resin.

In addition, a fluorine resin having particularly good weather resistance is also preferably used. Specifically, ethylene tetrafluoride-ethylene copolymer (ETFE), polyvinyl fluoride resin (PVF), polyvinylidene fluoride resin (PVDF), polytetrafluoroethylene resin (TFE), ethylene tetrafluoride-6 There are fluorinated propylene copolymer (FEP) and poly (trifluorotrifluoroethylene resin) (CTFE). Polyvinylidene fluoride resin is excellent from the viewpoint of weather resistance, but tetrafluoroethylene-ethylene copolymer is excellent from the viewpoint of both weather resistance and mechanical strength. Moreover, it is desirable to perform a corona treatment and a plasma treatment on the surface protective sheet in order to improve the adhesiveness with a material constituting another layer such as a layer made of a solar cell encapsulant sheet. It is also possible to use a sheet that has been subjected to stretching treatment for improving mechanical strength, for example, a biaxially stretched polypropylene sheet.

When glass is used as the surface protective sheet, the total light transmittance of light having a wavelength of 350 to 1400 nm is preferably 80% or more, more preferably 90% or more. As such a glass substrate, it is common to use white plate glass with little absorption in the infrared part, but even blue plate glass has little influence on the output characteristics of the solar cell module if the thickness is 3 mm or less. Further, tempered glass can be obtained by heat treatment to increase the mechanical strength of the glass substrate, but float plate glass without heat treatment may be used. Further, an antireflection coating may be provided on the light receiving surface side of the glass substrate in order to suppress reflection.

(Protective sheet for solar cell module (back protective sheet))
Although there is no restriction | limiting in particular in the back surface protection sheet used in the solar cell module which is preferable embodiment of this invention, Since it is located in the outermost layer of a solar cell module, it is weather resistance and mechanical strength similarly to the above-mentioned surface protection sheet. Etc. are required. Therefore, you may comprise a back surface protection sheet with the material similar to a surface protection sheet. That is, the above-mentioned various materials that can be used in the surface protective sheet can also be used in the back surface protective sheet. In particular, a polyester resin and glass can be preferably used.

Moreover, since the back surface protection sheet does not assume the passage of sunlight, the transparency required for the surface protection sheet is not necessarily required. Therefore, a reinforcing plate may be attached to increase the mechanical strength of the solar cell module or to prevent distortion and warpage due to temperature change. For example, a steel plate, a plastic plate, an FRP (glass fiber reinforced plastic) plate or the like can be preferably used.

(Solar cell element)
The solar cell element in the solar cell module which is a preferred embodiment of the present invention is not particularly limited as long as it can generate power using the photovoltaic effect of a semiconductor. For example, silicon (single crystal system, polycrystalline system, Amorphous solar cells, compound semiconductor (Group 3-5, 2-6, etc.) solar cells, wet solar cells, organic semiconductor solar cells and the like can be used. Among these, a polycrystalline silicon solar cell is preferable from the viewpoint of balance between power generation performance and cost.

Both silicon and compound semiconductors have excellent characteristics as solar cell elements, but are known to be easily damaged by external stress, impact, and the like. Since the solar cell encapsulant sheet of the present invention is excellent in flexibility, it has a great effect of absorbing stress, impact, etc. on the solar cell element and preventing damage to the solar cell element. Therefore, in the solar cell module which is a preferred embodiment of the present invention, it is desirable that the layer made of the sheet for solar cell sealing material of the present invention is directly joined to the solar cell element.

In addition, when the solar cell encapsulant sheet has thermoplasticity, it is possible to take out the solar cell element relatively easily even after the solar cell module is once manufactured. Are better. Since the essential component of the sheet | seat for solar cell sealing materials of this invention has thermoplasticity, it is easy to provide thermoplasticity also as the whole solar cell sealing material, and it is preferable also from a recyclable viewpoint.

(Method for manufacturing solar cell module)
In the production of the solar cell module, the sheet for solar cell encapsulant of the present invention is prepared in advance, and the laminating temperature is usually 120 to 170 ° C. by a conventional laminating method in which the sheet is pressure-bonded at a melting temperature. In scope, a module having the configuration described above can be formed. In this case, the solar cell encapsulant sheet has excellent cross-linking properties by containing the organic peroxide [Y], and it is not necessary to go through a two-step bonding process in forming the module. It can be completed in a short time, and the module productivity can be remarkably improved.

〔Power generation equipment〕
The solar cell module which is a preferred embodiment of the present invention is excellent in productivity, power generation efficiency, life and the like. For this reason, the power generation equipment using such a solar cell module is excellent in cost, power generation efficiency, life, etc., and has a high practical value.

The power generation equipment described above is suitable for long-term use, whether outdoors or indoors, such as being installed on the roof of a house, used as a mobile power source for outdoor activities such as camping, or used as an auxiliary power source for automobile batteries.

Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples. In the following description of Examples and the like, “parts” means “parts by weight” unless otherwise specified.

Measure methods for various physical properties are as follows.

[Ethylene / propylene / α-olefin copolymers, etc.]
<Weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn)>
Gel permeation chromatography (GPC) measurement of an ethylene / propylene / α-olefin copolymer or the like was performed to obtain a polystyrene-equivalent molecular weight M _i-PSt of each fraction. Next, M _i-PSt is _expressed by the formula [η] _i-PSt · M _i-PSt = [η] _i-EPR · M _i-EPR and [η] _i-PSt = 1.37 × 10 ⁻⁴ M _{Using the} ^{formula of} _i-PSt ^0.686 , [η] _i-EPR = 7.2 × 10 ⁻⁴ M _i-EPR ^0.667 , it was converted to EPR converted molecular weight M _i-EPR . The molecular weight distribution (Mw / Mn) was calculated using the EPR converted molecular weight.

The gel permeation chromatography (GPC) method was measured as follows using a gel permeation chromatograph Alliance GPC-2000 manufactured by Waters. The separation column has two TSKgel GNH6-HT and two TSKgel GNH6-HTL. The column size is 7.5 mm in diameter and 300 mm in length, the column temperature is 140 ° C., and the mobile phase is Using o-dichlorobenzene (Wako Pure Chemical Industries, Ltd.) and 0.025% by weight of BHT (Takeda Pharmaceutical Co., Ltd.) as an antioxidant, the sample was transferred at 1.0 ml / min. The amount of sample injection was 500 μl, and a differential refractometer was used as a detector. Standard polystyrene used was made by Tosoh Corporation for molecular weights of Mw <1000 and Mw> 4 × 10 ⁶ , and that of Pressure Chemical Co. for 1000 ≦ Mw ≦ 4 × 10 ⁶ .

<density>
The density was measured at 23 ° C. according to ASTM D1505.

<Double bond amount (unsaturated bond amount)>
The amount of double bonds was determined by ¹ H-NMR measurement of an ethylene / propylene / α-olefin copolymer (manufactured by JEOL Ltd., “ECX400P type nuclear magnetic resonance apparatus”). Here, vinyl type double bond (vinyl group), vinylidene type double bond (vinylidene group), disubstituted olefin type double bond and trisubstituted olefin type double bond are observed as signals derived from the double bond. The The amount of double bonds was quantified from the integrated intensity of each signal. The main chain methylene signal of the ethylene / α-olefin copolymer was defined as a chemical shift standard (1.2 ppm). The total amount of vinyl groups and vinylidene groups is determined as the amount of molecular terminal double bonds, and the total amount of disubstituted olefin type double bonds and trisubstituted olefin type double bonds is determined as the amount of internal unsaturated bonds. (Total unsaturated bond amount) was determined as the sum of each double bond. An analysis with 0.1 / 1000 C as the limit of quantification was performed, and when a signal was confirmed even in the case of less than 0.1 / 1000 C, a calibration curve was extrapolated to calculate the double bond amount.

　各式中、＊は水素原子以外の原子との結合手を示す。

In each formula, * indicates a bond with an atom other than a hydrogen atom.

The peak of each hydrogen atom ae is observed near the following.

-Peak of hydrogen atom a: 4.60 ppm
-Peak of hydrogen atom b: 4.85 ppm
-Peak of hydrogen atom c: 5.10 ppm
-Peak of hydrogen atom d: 5.25 ppm
-Peak of hydrogen atom e: 5.70 ppm
The quantitative formula for the amount of double bonds is as follows.

Vinyl-type double bond amount = {(integral intensity of signal b) + (integral intensity of signal e)} / 3
-Vinylidene type double bond amount = (integral intensity of signal a) / 2
・ 2 substituted olefin type double bond amount = (integrated intensity of signal d) / 2
・ 3-substituted olefin type double bond amount = (integrated intensity of signal c)
<Melting point Tm>
In the DSC measuring device, after the condition was adjusted for 72 hours or more at 23 ° C. ± 2 ° C., the sample was cooled to −40 ° C. and then increased to 200 ° C. at a temperature rising rate of 10 ° C./min. DSC curve obtained when held at 200 ° C. for 10 minutes, cooled to −20 ° C. at a cooling rate of 10 ° C./min, held at −20 ° C. for 1 minute, and then measured again at a heating rate of 10 ° C./min It was created. The melting point obtained at this time was defined as Tm.

<MFR>
MFR was measured at 190 ° C. and 2.16 kg load according to ASTM D1238.

<Comonomer content (composition)>
A JNM GX-400 NMR measuring apparatus manufactured by JEOL Ltd. was used. A 0.35 g sample is dissolved by heating in 2.0 ml of hexachlorobutadiene. This solution is filtered through a glass filter (G2), 0.5 ml of deuterated benzene is added, and the solution is placed in an NMR tube having an inner diameter of 10 mm, and ¹³ C-NMR measurement is performed at 120 ° C. The number of integration is 8000 times or more. From the obtained ¹³ C-NMR spectrum, the ethylene content (mol%), propylene content (mol%) and α-olefin content (mol%) in the copolymer were quantified.

Production Examples 1 to 5 which are production examples of the ethylene / propylene / α-olefin copolymer according to the present invention are shown below.

[Production Example 1]
Copolymerization with ethylene, propylene and 1-octene continuously at a polymerization temperature of 100 ° C. and a polymerization pressure of 2.0 MPaG using a 30 L stainless steel polymerization vessel equipped with stirring blades (stirring rotation speed = 250 rpm). Went. Hourly dehydrated and purified hexane 35 L, ethylene 5.5 kg, propylene 6.2 kg, 1-octene 8.4 kg, hydrogen 5 NL, bis (1,3-dimethylcyclohexane) Pentadienyl) zirconium dichloride was continuously supplied at a rate of 0.1 mmol, methylaluminoxane was converted to aluminum at a rate of 10 mmol, and triisobutylaluminum was continuously supplied at a rate of 50 mmol to carry out a copolymerization reaction. The opening degree of the liquid level control valve is adjusted so that the produced hexane solution of ethylene / propylene / 1-octene copolymer maintains the amount of solution in the polymerization vessel of 20 L through the outlet provided in the side wall of the polymerization vessel. It discharged continuously while adjusting. The obtained hexane solution of ethylene / propylene / 1-octene copolymer was introduced into a heater and heated to 180 ° C., and 3 mL of methanol was added every hour as a catalyst deactivator to stop the polymerization, and the pressure was reduced. An ethylene / propylene / 1-octene copolymer (copolymer A) was obtained by continuously transferring to a devolatilization step and drying. The physical properties are shown in Table 1.

[Production Example 2]
In Production Example 1, an ethylene / propylene / 1-octene copolymer (Copolymer B) was prepared in the same manner as in Production Example 1 except that the propylene feed amount, 1-octene feed amount and hydrogen feed amount were appropriately changed. Obtained. The physical properties are shown in Table 1.

[Production Example 3]
In Production Example 1, an ethylene / propylene / 1-octene copolymer (Copolymer C) was prepared in the same manner as in Production Example 1 except that the propylene feed amount, 1-octene feed amount and hydrogen feed amount were appropriately changed. Obtained. The physical properties are shown in Table 1.

[Production Example 4]
In Production Example 1, an ethylene / propylene / 1-octene copolymer (Copolymer D) was prepared in the same manner as in Production Example 1 except that the propylene feed amount, 1-octene feed amount and hydrogen feed amount were appropriately changed. Obtained. The physical properties are shown in Table 1.

[Production Example 5]
In Production Example 1, an ethylene / propylene / 1-octene copolymer (Copolymer E) was prepared in the same manner as in Production Example 1 except that the propylene feed amount, 1-octene feed amount and hydrogen feed amount were appropriately changed. Obtained. The physical properties are shown in Table 1.

Production Examples 6 to 14 are shown below as production examples of the ethylene / propylene / α-olefin copolymer used as a comparative example of the present invention.

[Production Example 6]
In Production Example 1, an ethylene / propylene / 1-octene copolymer (copolymer F) was prepared in the same manner as in Production Example 1 except that the propylene feed amount, 1-octene feed amount and hydrogen feed amount were appropriately changed. Obtained. Physical properties are shown in Table 2-1.

[Production Example 7]
In Production Example 1, an ethylene / propylene copolymer (Copolymer G) was obtained in the same manner as in Production Example 1 except that 1-octene feed was stopped and the propylene feed amount and hydrogen feed amount were appropriately changed. It was. Physical properties are shown in Table 2-1.

[Production Example 8]
In Production Example 7, ethylene / 1-butene copolymer (copolymer) was prepared in the same manner as in Production Example 1 except that propylene was changed to 1-butene and the 1-butene feed amount and the hydrogen feed amount were appropriately changed. Combined H) was obtained. Physical properties are shown in Table 2-1.

[Production Example 9]
In Production Example 1, an ethylene / propylene copolymer (Copolymer I) was obtained in the same manner as in Production Example 1, except that 1-octene feed was stopped and the propylene feed amount and hydrogen feed amount were appropriately changed. It was. Physical properties are shown in Table 2-1.

[Production Example 10]
An ethylene / 1-butene copolymer (copolymer) was prepared in the same manner as in Production Example 1 except that propylene was changed to 1-butene and the 1-butene feed amount and the hydrogen feed amount were appropriately changed in Production Example 9. J) was obtained. Physical properties are shown in Table 2-1.

[Production Example 11]
An ethylene / propylene / 1-octene copolymer (copolymer) was prepared in the same manner as in Production Example 1 except that the propylene feed amount, 1-octene feed amount, hydrogen feed amount and polymerization pressure were appropriately changed. K) was obtained. The physical properties are shown in Table 2-2.

[Production Example 12]
Ethylene / propylene was prepared in the same manner as in Production Example 1 except that 1-octene was changed to 1-butene in Production Example 1 and the propylene feed amount, 1-butene feed amount, hydrogen feed amount and polymerization pressure were appropriately changed. A 1-butene copolymer (Copolymer L) was obtained. The physical properties are shown in Table 2-2.

[Production Example 13]
An ethylene / 1-butene copolymer (copolymer M) was obtained in the same manner as in Production Example 1 except that the 1-butene feed amount and the hydrogen feed amount were appropriately changed in Production Example 7. The physical properties are shown in Table 2-2.

[Production Example 14]
In Production Example 7, an ethylene / 1-butene copolymer (Copolymer N) was obtained in the same manner as in Production Example 1, except that the 1-butene feed amount and the hydrogen feed amount were appropriately changed. The physical properties are shown in Table 2-2.

In Comparative Example 10, the following commercially available products were used.

Exact (registered trademark) 5361 (manufactured by ExxonMobil Chemical Co., Ltd.) was used as the ethylene / 1-octene copolymer. The physical properties are shown in Table 2-2.

[Example 1]
A sheet molding machine with a coat hanger type T die (lip shape; 270 x 0.8 mm) mounted on a single screw extruder (screw diameter: 20 mmφ · L / D = 28) manufactured by Thermo Plastic Co., Ltd. 1 ethylene / propylene / 1-octene copolymer (copolymer A) was molded under the conditions of a die temperature = 190 ° C., a roll temperature of 30 ° C., and a winding speed of 1.0 m / min, and a thickness = 0.5 mm. A sheet was obtained. Using this sheet, tensile fracture stress and tensile fracture strain were evaluated.

Operated one extruder of 3 types, 3 layers cast molding machine manufactured by Modern Machinery Co., Ltd. Prime Polymer Pro 107 manufactured by Prime Polymer Co., Ltd. and ethylene / propylene / 1-octene copolymer (Copolymer A) A sample obtained by dry blending with a weight ratio of 50:50 was molded at an extruder temperature = 240 ° C., a die temperature = 240 ° C., an adapter temperature = 240 ° C., and a screw rotation speed of 100 rpm, and 5 kg of a 0.05 mm-thick film was produced. . The fish eyes were visually observed using the film, and “◯” indicates that there is almost no fish eye, “△” indicates that there are few fish eyes, and “×” indicates that many fish eyes have been confirmed. .

Each evaluation result is shown in Table 1.

[Examples 2 and 5 and Comparative Examples 1 to 10]
Except that the ethylene / propylene / 1-octene copolymer (copolymer A) described in Example 1 was changed to the copolymers described in Tables 1 and 2, the thickness was the same as in Example 1. A 0.5 mm sheet and a 0.05 mm thick film were prepared.

The evaluation results are shown in Table 1, Table 2-1, and Table 2-2.

[Example 3]
A sheet molding machine with a coat hanger type T die (lip shape; 270 x 0.8 mm) mounted on a single screw extruder (screw diameter: 20 mmφ · L / D = 28) manufactured by Thermo Plastic Co., Ltd. No. 1 ethylene / propylene / 1-octene copolymer (copolymer C) was molded at a die temperature of 120 ° C., a roll temperature of 30 ° C., a winding speed of 1.0 m / min, and a sheet having a thickness of 0.5 mm. Got. Using this sheet, tensile fracture stress and tensile fracture strain were evaluated.

Operated one extruder of 3 types, 3 layers cast molding machine manufactured by Modern Machinery Co., Ltd. Prime Polymer Pro 107 manufactured by Prime Polymer Co., Ltd. and ethylene / propylene / 1-octene copolymer (Copolymer C) A sample obtained by dry blending with a weight ratio of 50:50 was molded at an extruder temperature = 240 ° C., a die temperature = 240 ° C., an adapter temperature = 240 ° C., and a screw rotation speed of 100 rpm, and 5 kg of a film having a thickness of 0.05 mm was produced. . The fish eyes were visually observed using the film, and “◯” indicates that there is almost no fish eye, “△” indicates that there are few fish eyes, and “×” indicates that many fish eyes have been confirmed. .

Each evaluation result is shown in Table 1.

[Example 4]
The ethylene / propylene / 1-octene copolymer (copolymer A) described in Example 1 was replaced with the copolymer described in Table 1 in the same manner as in Example 1 except that the thickness was 0.5 mm. A sheet and a film having a thickness of 0.05 mm were prepared.

Each evaluation result is shown in Table 1.

Claims (8)

A film or sheet containing an ethylene / propylene / α-olefin copolymer [X] that satisfies the following requirement (x-1).
(X-1) an α-olefin having 74 to 92 mol% of the structural unit (i) derived from ethylene, 5 to 16 mol% of the structural unit (ii) derived from propylene, and having 5 to 20 carbon atoms. 3 to 10 mol% of the derived structural unit (iii) (provided that the total of the structural units (i), (ii) and (iii) is 100 mol%). The film or sheet according to claim 1, wherein the copolymer [X] further satisfies any one or more of the following requirements (x-2) and (x-3).
(X-2) The density is 850 to 900 kg / m ³ .
(X-3) According to ASTM D1238, MFR measured at 190 ° C. and a load of 2.16 kg is 0.1 to 50 g / 10 min. 3. The film or sheet according to claim 1, wherein the structural unit (iii) derived from an α-olefin having 5 to 20 carbon atoms is a structural unit derived from 1-octene. The film or sheet according to any one of claims 1 to 3, having a thickness of 0.01 mm to 2 mm. A solar cell encapsulant comprising the film or sheet according to any one of claims 1 to 4. A solar cell module comprising the solar cell encapsulant according to claim 5. A method for producing a sheet for a solar cell encapsulant, comprising a step of obtaining a sheet from a resin composition containing an ethylene / propylene / α-olefin copolymer [X] that satisfies the following requirement (x-1).
(X-1) an α-olefin having 74 to 92 mol% of the structural unit (i) derived from ethylene, 5 to 16 mol% of the structural unit (ii) derived from propylene, and having 5 to 20 carbon atoms. 3 to 10 mol% of the derived structural unit (iii) (provided that the total of the structural units (i), (ii) and (iii) is 100 mol%). A resin composition comprising an ethylene / propylene / α-olefin copolymer [X] that satisfies the following requirement (x-1).
(X-1) an α-olefin having 74 to 92 mol% of the structural unit (i) derived from ethylene, 5 to 16 mol% of the structural unit (ii) derived from propylene, and having 5 to 20 carbon atoms. 3 to 10 mol% of the derived structural unit (iii) (provided that the total of the structural units (i), (ii) and (iii) is 100 mol%).