WO2012070245A1 - Encapsulant de cellule solaire et module de cellules solaires utilisant ledit encapsulant - Google Patents

Encapsulant de cellule solaire et module de cellules solaires utilisant ledit encapsulant Download PDF

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WO2012070245A1
WO2012070245A1 PCT/JP2011/006547 JP2011006547W WO2012070245A1 WO 2012070245 A1 WO2012070245 A1 WO 2012070245A1 JP 2011006547 W JP2011006547 W JP 2011006547W WO 2012070245 A1 WO2012070245 A1 WO 2012070245A1
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solar cell
ethylene
olefin
conjugated polyene
sheet
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PCT/JP2011/006547
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English (en)
Japanese (ja)
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成伸 池永
文人 竹内
啓二 渡辺
伊藤　智章
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三井化学株式会社
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Priority to JP2012545622A priority Critical patent/JP5871815B2/ja
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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
    • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
    • C08L23/16—Elastomeric ethene-propene or ethene-propene-diene copolymers, e.g. EPR and EPDM rubbers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
    • H01L31/042—PV modules or arrays of single PV cells
    • H01L31/048—Encapsulation of modules
    • H01L31/0481—Encapsulation of modules characterised by the composition of the encapsulation material
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy

Definitions

  • the present invention relates to a solar cell encapsulant that is excellent in transparency, flexibility, adhesiveness, heat resistance, appearance, crosslinking characteristics, electrical characteristics, and extrusion moldability. Furthermore, this invention relates to the solar cell module using such a solar cell sealing material.
  • solar cells are attracting attention as a means of generating energy that is clean and free from depletion.
  • a solar cell 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 is generally manufactured by the following procedure. First, a crystalline solar cell element (hereinafter sometimes referred to as a power generation element or a cell) containing polycrystalline silicon or single crystal silicon, or amorphous silicon or crystalline silicon formed on a substrate such as glass A thin-film solar cell element including a thin film (several thickness several ⁇ m) is obtained. Next, to obtain a crystalline solar cell module, a solar cell module protective sheet (surface protective sheet) / solar cell encapsulant / crystalline solar cell element / solar cell encapsulant / solar cell module protective sheet ( Laminate in the order of the back protection sheet).
  • a solar cell module protective sheet surface protective sheet
  • the thin-film solar cell element / solar cell sealing material / solar cell module protective sheet (back surface protective sheet) are laminated in this order. Then, a solar cell module is manufactured by utilizing the lamination method etc. which vacuum-suck these and heat-press them.
  • the solar cell module manufactured in this way has weather resistance and is suitable for outdoor use such as a roof portion of a building.
  • Patent Document 1 discloses a sealing film that is made of an EVA composition containing a cross-linking agent and trimellitic acid ester and that is excellent in both adhesiveness and film-forming properties.
  • EVA composition containing a cross-linking agent and trimellitic acid ester and that is excellent in both adhesiveness and film-forming properties.
  • components such as acetic acid gas generated by the decomposition of EVA may affect the solar cell element.
  • the polyolefin copolymer described in Patent Document 2 has problems such as insufficient cross-linking properties or increased distortion caused by the cross-linking, so that the deformation of the glass substrate in the solar cell module. And may cause cracking.
  • the present invention has been made in view of such problems of the prior art; the object of the present invention is necessary for an ethylene / ⁇ -olefin / non-conjugated polyene copolymer contained in a solar cell encapsulant.
  • the subject of this invention is providing the solar cell module using such a solar cell sealing material.
  • the system voltage may be increased for the purpose of reducing transmission loss in a large-scale power generation system.
  • the potential difference between the frame and the solar cell element in the solar cell module increases. Since the frame of the solar cell module is generally grounded, when the system voltage is 600V to 1000V, the maximum potential difference between the frame of the solar cell module and the solar cell element is 600V to 1000V, which is the same as the system voltage.
  • glass has a lower electrical resistance than the sealing material, a high potential difference is also generated between the glass and the solar cell element through the frame.
  • the solar cell module performs daytime power generation with a large potential difference between the glass of the solar cell module and the solar cell element.
  • the output characteristics of the solar cell module that generates power in such a state may be greatly degraded.
  • PID Physical Induced Degradation
  • production of PID in a solar cell module is suppressed by improving the sealing member which is directly in contact with the crystalline solar cell element.
  • the subject of this invention is providing the solar cell module using such a solar cell sealing material.
  • polyethylene-based elastomer compositions particularly polyethylene-based elastomer compositions containing non-conjugated polyenes as monomer units, have a problem of high viscosity during kneading and low moldability. That is, it is required to obtain a polyethylene-based elastomer composition excellent in extrusion processability without impairing transparency and crosslinking characteristics.
  • the second aspect of the present invention has been made in view of the above circumstances, and provides a solar cell encapsulant comprising a polyethylene-based elastomer composition that is excellent in extrusion processability without impairing transparency and crosslinking properties. For the purpose.
  • the present inventors have found that specific content of ethylene units, ⁇ -olefin units and non-conjugated polyene units, MFR, and Shore A hardness satisfy specific requirements.
  • a solar cell encapsulant with excellent properties such as transparency, flexibility, adhesion, heat resistance, appearance, cross-linking properties, electrical properties and extrusion moldability can be obtained.
  • the present invention was completed. That is, according to this invention, the solar cell sealing material shown below is provided.
  • a solar cell encapsulant comprising an ethylene / ⁇ -olefin / non-conjugated polyene copolymer satisfying the following requirements a1) to a3).
  • a1 The content ratio of structural units derived from ethylene is 80 to 90 mol%, the content ratio of structural units derived from ⁇ -olefins having 3 to 20 carbon atoms is 9.99 to 19.99 mol%, and non- The content ratio of the structural unit derived from the conjugated polyene is 0.01 to 5.0 mol%.
  • a2) According to ASTM D1238, MFR measured under the conditions of 190 ° C. and 2.16 kg load is 10 to 50 g / 10 min. a3)
  • the Shore A hardness measured according to ASTM D2240 is 60 to 85.
  • At least one selected from the group consisting of an ultraviolet absorber, a heat-resistant stabilizer, and a hindered amine type light stabilizer is 0 with respect to 100 parts by weight of the ethylene / ⁇ -olefin / non-conjugated polyene copolymer.
  • a is derived from ethylene contained in the ethylene / ⁇ -olefin / non-conjugated polyene copolymer
  • a is derived from ethylene contained in the ethylene / ⁇ -olefin / non-conjugated polyene copolymer
  • c indicates the ratio of ethylene / ⁇ -olefin chain constituent units (ethylene / ⁇ -olefin dyad mole fraction)
  • d indicates constituent units of ethylene / non-conjugated polyene chains.
  • a front-side transparent protective member, a back-side protective member, a solar cell element sandwiched between the front-side transparent protective member and the back-side protective member, and the solar cell element as the front-side transparent protective member A solar cell module provided with a sealing member for sealing between the back surface side protection member, The solar cell module, wherein the sealing member is a cured product of the solar cell sealing material according to any one of [1] to [13].
  • the present inventors have studied to add oil or plasticizer to the polyethylene elastomer composition in order to improve the moldability of the obtained solar cell encapsulant. As a result, it has been found that when oil or a plasticizer is added, the crosslinking characteristics of the polyethylene elastomer composition containing conjugated polyene as a monomer unit and the transparency of the cured product may be lowered. According to the 2nd form of this invention, the solar cell sealing material shown below is provided.
  • a crosslinking aid selected from the group consisting of a crosslinking aid, an ultraviolet absorber, a weather resistance stabilizer, an antioxidant, and an adhesion promoter.
  • a solar cell module comprising a sealing member that seals the solar cell element between at least one of the protective members, The solar cell module, wherein the sealing member is a cured product of the solar cell sealing material according to any one of [16] to [19] and [23].
  • the solar cell encapsulant of the present invention contains a specific ethylene / ⁇ -olefin / non-conjugated polyene copolymer, transparency, flexibility, adhesiveness, heat resistance, appearance, cross-linking properties, electrical properties, and extrusion molding It becomes a solar cell sealing material excellent in various properties such as properties.
  • a solar cell encapsulant having a good balance of various characteristics can be obtained. Further, even if the temperature rises during use of the solar cell module, the encapsulant may be deformed. Trouble can be suppressed. And the solar cell module excellent in economical efficiency, such as cost, can be provided, without impairing the external appearance of a solar cell.
  • a solar cell module is provided that can significantly suppress the generation of PID even if power generation is continued with a high voltage applied between the frame and the solar cell element. can do.
  • the solar cell encapsulant of the first aspect of the present invention contains an ethylene / ⁇ -olefin / non-conjugated polyene copolymer.
  • the ethylene / ⁇ -olefin / non-conjugated polyene copolymer used for the solar cell encapsulant of the present invention is obtained by copolymerizing ethylene, an ⁇ -olefin having 3 to 20 carbon atoms, and a non-conjugated polyene. It is done.
  • ⁇ -olefin ⁇ -olefins having 3 to 20 carbon atoms can be used singly or in combination of two or more.
  • Particularly preferred ⁇ -olefins are ⁇ -olefins having 10 or less carbon atoms, and particularly preferred ⁇ -olefins are ⁇ -olefins having 3 to 8 carbon atoms.
  • Specific examples of such ⁇ -olefins include propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3,3-dimethyl-1-butene, and 4-methyl-1- Examples include pentene, 1-octene, 1-decene, and 1-dodecene. Of these, propylene, 1-butene, 1-pentene, 1-hexene and 4-methyl-1-pentene are preferred because of their availability.
  • non-conjugated polyene a compound having two or more non-conjugated unsaturated bonds can be used without limitation.
  • the non-conjugated polyene either a non-conjugated cyclic polyene or a non-conjugated chain polyene can be used, and a non-conjugated cyclic polyene and a non-conjugated chain polyene can also be used in combination.
  • the non-conjugated polyene includes a non-conjugated polyene in which only one carbon / carbon double bond that can be polymerized with a catalyst exists in one molecule, and a carbon / carbon double bond.
  • any non-conjugated polyene having two carbon / carbon double bonds that can be polymerized with the catalyst may be used.
  • the non-conjugated polyene in which only one polymerizable carbon / carbon double bond is present in one molecule does not include a chain polyene in which both ends are vinyl groups (CH 2 ⁇ CH—).
  • a chain polyene in which both ends are vinyl groups (CH 2 ⁇ CH—) When there are two or more carbon / carbon double bonds in such a non-conjugated polyene, only one carbon / carbon double bond is present as a vinyl group at the molecular end, and other carbon / carbon double bonds are present.
  • non-conjugated cyclic polyene and non-conjugated chain polyene includes the above-mentioned non-conjugated polyene having only one polymerizable carbon / carbon double bond in one molecule, and carbon / carbon double bond. Of these, non-conjugated polyenes in which two carbon / carbon double bonds that can be polymerized with the catalyst exist in one molecule are also included.
  • the conjugated chain polyene also includes conjugated triene or tetraene.
  • non-conjugated polyene examples include compounds described in paragraphs 0061 to 0084 of WO 2005/105867 and paragraphs 0026 to 0035 of JP 2008-308696 A.
  • non-conjugated chain polyenes include 1,4-hexadiene, 1,5-heptadiene, 1,6-octadiene, 1,7-nonadiene, 1,8-decadiene, 1,12-tetradecadiene, 3- Methyl-1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 4-ethyl-1,4-hexadiene, 3,3-dimethyl-1,4-hexadiene, 5-methyl-1,4-heptadiene, 5-ethyl-1,4-heptadiene, 5-methyl-1,5-heptadiene, 6-methyl-1,5-heptadiene, 5-ethyl-1,5-heptadiene, 4-methyl-1,4-octadiene, 5-methyl-1,4-octadiene, 4-ethyl-1,4-octadiene, 5-ethyl-1,4-o
  • Non-conjugated trienes or tetraenes include 4-ethylidene-8-methyl-1,7-nonadiene, 6,10-dimethyl-1,5,9-undecatriene, 5,9-dimethyl-1,4,8- Decatriene, 4,8-dimethyl-1,4,8-decatriene, 6,9-dimethyl-1,5,8-decatriene, 6,8,9-trimethyl-1,5,8-decatriene, 6,10, 14-trimethyl-1,5,9,13-pentadecatetraene, 6-ethyl-10-methyl-1,5,9-undecatriene, 4-ethylidene-8,12-dimethyl-1,7,11 -Tridecatriene can be mentioned.
  • These non-conjugated chain polyenes can be used alone or in combination of two or more.
  • 7-methyl-1,6-octadiene, 4,8-dimethyl-1,4,8-decatriene and the like are used
  • Non-conjugated polyene having only one polymerizable carbon / carbon double bond in one molecule includes an alicyclic moiety having one carbon / carbon double bond (unsaturated bond) and a metallocene such as an alkylidene group.
  • examples thereof include a polyene composed of a chain portion that does not polymerize with a catalyst or has an internal olefin bond (carbon / carbon double bond) that is poorly polymerizable.
  • Specific examples include 5-ethylidene-2-norbornene (ENB), 5-propylidene-2-norbornene, and 5-butylidene-2-norbornene. Of these, 5-ethylidene-2-norbornene (ENB) is preferred.
  • non-conjugated polyenes in which only one polymerizable carbon / carbon double bond is present in one molecule include, for example, 2-methyl-2,5-norbornadiene, 2-ethyl-2,5-norbornadiene, etc. Can be mentioned. These non-conjugated polyenes in which only one polymerizable carbon / carbon double bond is present in one molecule are used singly or in combination of two or more.
  • non-conjugated polyene having two polymerizable carbon / carbon double bonds in one molecule among the carbon / carbon double bonds include 5-vinyl-2-norbornene (VNB), 5- 5-alkenyl-2-norbornene such as allyl-2-norbornene; 2,5-norbornadiene, dicyclopentadiene (DCPD), tetracyclo [4,4,0,12.5,17.10] deca-3,8- Examples include alicyclic polyenes such as dienes; ⁇ , ⁇ -dienes such as 1,7-octadiene and 1,9-decadiene.
  • VNB 5-vinyl-2-norbornene
  • dicyclopentadiene 2,5-norbornadiene, 1,7-octadiene and 1,9-decadiene
  • VNB 5-vinyl-2-norbornene
  • Dicyclopentadiene is particularly preferred.
  • ethylene / ⁇ -olefin / non-conjugated polyene copolymer examples include ethylene / propylene / 4,8-dimethyl-1,4,8-decatriene (DMDT) copolymer, ethylene / propylene / 5-vinyl- 2-Norbornene (VNB) copolymer, Ethylene / propylene / 5-ethylidene-2-norbornene (ENB) copolymer, Ethylene / propylene / dicyclopentadiene copolymer, Ethylene / propylene / 4,8-dimethyl-1 , 4,8-decatriene (DMDT) -5-vinyl-2-norbornene (VNB) quaternary copolymer, ethylene-propylene-5-butylidene-2-norbornene-5-vinyl-2-norbornene (VNB) quaternary Copolymer, and ethylene
  • the ethylene / ⁇ -olefin / non-conjugated polyene copolymer contained in the solar cell encapsulant of the first aspect of the present invention satisfies the following requirements a1) to a3).
  • the proportion of structural units derived from an ⁇ -olefin having 3 to 20 carbon atoms (hereinafter also referred to as “ ⁇ -olefin unit”) contained in the ethylene / ⁇ -olefin / non-conjugated polyene copolymer is 9.99 to 19 .99 mol%, preferably 11 to 19.99 mol%, more preferably 12.5 to 19 mol%.
  • the content ratio of the ⁇ -olefin unit is less than 9.99 mol%, the crystallinity is high and the transparency tends to be lowered. Furthermore, extrusion molding at a low temperature becomes difficult, and for example, extrusion molding at a high temperature of 130 ° C. or higher is required. For this reason, when an organic peroxide is kneaded into the ethylene / ⁇ -olefin / non-conjugated polyene copolymer, a crosslinking reaction proceeds in the extruder, and a gel-like foreign material is formed on the sheet of the solar cell sealing material. Occurs, and the appearance of the sheet tends to deteriorate. In addition, the flexibility is low, and there are cases where cracking of a cell which is a solar cell element, chipping of a thin film electrode, or the like occurs when a solar cell module is laminated.
  • non-conjugated polyene units The proportion of structural units derived from non-conjugated polyene (hereinafter also referred to as “non-conjugated polyene units”) contained in the ethylene / ⁇ -olefin / non-conjugated polyene copolymer is 0.01 to 5.0 mol%, Preferably it is 0.01 to 4.5 mol%, more preferably 0.05 to 4.0 mol%. If the content ratio of the non-conjugated polyene unit is less than 0.01 mol%, the crosslinking characteristics may be deteriorated.
  • the ethylene / ⁇ -olefin / non-conjugated polyene copolymer may have a long branched chain, or the ethylene / ⁇ -olefin / non-conjugated polyene copolymer.
  • the polymer tends to gel easily. Therefore, a gel-like foreign material may be generated on the sheet of the solar cell sealing material, and the appearance of the sheet may be deteriorated.
  • melt flow rate (MFR) of the ethylene / ⁇ -olefin / non-conjugated polyene copolymer measured at 190 ° C. under a load of 2.16 kg is 10 to 50 g / 10 min, preferably Is 10 to 40 g / 10 minutes, more preferably 10 to 35 g / 10 minutes, still more preferably 12 to 27 g / 10 minutes, and most preferably 15 to 25 g / 10 minutes.
  • the MFR of the ethylene / ⁇ -olefin / non-conjugated polyene copolymer includes the polymerization temperature, the polymerization pressure, the molar ratio of the ethylene and ⁇ -olefin monomer concentrations and the hydrogen concentration in the polymerization system, which will be described later. It can be adjusted by adjusting.
  • the MFR is less than 10 g / 10 min
  • the fluidity of the resin composition containing the ethylene / ⁇ -olefin / non-conjugated polyene copolymer is lowered, and the productivity at the time of sheet extrusion molding is lowered.
  • the scorch property of a resin composition becomes high and it becomes easy to gelatinize. For this reason, the torque of the extruder rises and sheet molding may become difficult. Even if a sheet is obtained, the gel material generated in the extruder may cause irregularities on the surface of the sheet, which may deteriorate the appearance. When a voltage is applied, cracks are generated around the gel within the sheet, and the dielectric breakdown resistance is reduced.
  • the MFR is more than 50 g / 10 min, the molecular weight is low, so adhesion to a roll surface such as a chill roll occurs, and peeling is required, making it difficult to form a sheet with a uniform thickness. Furthermore, since there is no “stiffness” in the resin composition, it tends to be difficult to form a thick sheet of 0.3 mm or more. In addition, the crosslinking characteristics (particularly the crosslinking rate) at the time of laminate molding of the solar cell module are lowered, and a sufficient crosslinked body cannot be obtained, and the heat resistance tends to be lowered.
  • the Shore A hardness of the ethylene / ⁇ -olefin / non-conjugated polyene copolymer is 60 to 85, preferably 60 to 83, and more preferably 65 to 80.
  • the Shore A hardness of the ethylene / ⁇ -olefin / non-conjugated polyene copolymer is adjusted by controlling the content ratio of the ethylene unit of the ethylene / ⁇ -olefin / non-conjugated polyene copolymer to the above-mentioned numerical range. be able to.
  • an ethylene / ⁇ -olefin / non-conjugated polyene copolymer having a high content of ethylene units and a high density has a high Shore A hardness.
  • an ethylene / ⁇ -olefin / non-conjugated polyene copolymer having a low ethylene unit content and a low density has a low Shore A hardness.
  • the ethylene / ⁇ -olefin / non-conjugated polyene copolymer preferably satisfies the following requirements a5) to a10).
  • the B value determined from the 13 C-NMR spectrum and the following formula (1) of the ethylene / ⁇ -olefin / non-conjugated polyene copolymer is preferably 0.9 to 1.3, preferably 0.95 to 1. 3 is more preferable, and 0.95 to 1.2 is more preferable.
  • a is derived from ethylene contained in the ethylene / ⁇ -olefin / non-conjugated polyene copolymer
  • a is derived from ethylene contained in the ethylene / ⁇ -olefin / non-conjugated polyene copolymer
  • c indicates the ratio of ethylene / ⁇ -olefin chain constituent units (ethylene / ⁇ -olefin dyad mole fraction)
  • d indicates constituent units of ethylene / non-conjugated polyene chain.
  • e represents the proportion of constituent units derived from ⁇ -olefin ( ⁇ -olefin mole fraction)
  • f represents the constituent units derived from non-conjugated polyene. Ratio (non-conjugated polyene mole fraction).)
  • A, c, d, e and f in the formula (1) measure 13 C-NMR spectrum, JCRandall (Macromolecules, 15,353 (1982)), and J. Ray (Macrimolecules, 10,773 (1977)) et al. Can be determined based on reports. In these reports, a dyad of a carbon atom (methylene group) in a polymer main chain is obtained from a 13 C-NMR spectrum using a copolymer composed of ethylene-propylene. In addition, the randomness and blockiness that are forms of copolymerization of the copolymer are discussed in relation to the sequence of the copolymer.
  • the dyad mole fraction of the ⁇ -olefin and the non-conjugated polyene and the dyad mole fraction of the non-conjugated polyene are not considered because the mole fraction is low.
  • the dyad mole fraction of ethylene and non-conjugated polyene is twice the mole fraction of non-conjugated polyene.
  • the molar fraction of each component of the ethylene / ⁇ -olefin / non-conjugated polyene copolymer was separately calculated using the absorption strength based on the specific carbon of the non-conjugated polyene. Based on this, the ethylene-nonconjugated polyene dyad mole fraction was calculated. For other chain assignments with methylene carbon, the above literature was followed.
  • the B value can be adjusted by changing the polymerization catalyst when polymerizing the ethylene / ⁇ -olefin / non-conjugated polyene copolymer. More specifically, a copolymer having a B value in the above numerical range can be obtained by using a metallocene compound described later. The larger the B value, the shorter the block chain of ethylene units or ⁇ -olefin units, and the uniform distribution of ethylene units, ⁇ -olefin units, and nonconjugated polyene units, and ethylene / ⁇ -olefin / nonconjugated The composition distribution of the polyene copolymer is narrowed.
  • the composition distribution of the ethylene / ⁇ -olefin / non-conjugated polyene copolymer becomes wide.
  • extrusion molding at a high temperature of, for example, 130 ° C. or more is required.
  • an organic peroxide is kneaded into the ethylene / ⁇ -olefin / non-conjugated polyene copolymer, the crosslinking reaction proceeds in the extruder, and gel-like foreign matters are formed on the sheet of the solar cell encapsulant. And the appearance of the sheet tends to deteriorate.
  • the following is a specific method for determining the B value of a non-conjugated cyclic polyene copolymer obtained from ethylene, propylene and 5-ethylidene-2-norbornene (ENB), which are ethylene / ⁇ -olefin / non-conjugated polyene copolymers.
  • ENB 5-ethylidene-2-norbornene
  • (2) is the sum of the integral values of multiple peaks around 37-39 ppm
  • (6) is the sum of the integral values of multiple peaks around 29-31 ppm minus the integral values of ⁇ and ⁇ peaks (9 ) was obtained as the sum of the integrated values of a plurality of peaks in the vicinity of 44 to 48 ppm.
  • NN ENB-ENB chain
  • NP ENB-propylene chain
  • PP propylene-propylene chain
  • PE propylene-ethylene chain
  • EE ethylene-ethylene chain
  • NE ENB-ethylene chain
  • the larger the B value the shorter the block chain of ⁇ -olefin (propylene) units or non-conjugated polyene units, and the distribution of ⁇ -olefin (propylene) units and non-conjugated polyene units is more uniform. It shows that there is. Conversely, the smaller the B value, the more uneven the distribution of the nonconjugated polyene copolymer, indicating that the block chain becomes longer.
  • the “ethylene distribution parameter P” is measured according to the method shown below.
  • a measurement sample obtained by dissolving an ethylene / ⁇ -olefin / non-conjugated polyene copolymer in cyclohexane uses GPC-offline-FTIR, the eluent is cyclohexane, the flow rate is 1.0 mL / min, and the temperature is 60 ° C. Measure IR spectrum.
  • the resulting maximum peak in the range of the IR spectrum of 721 ⁇ 20cm -1 (A721cm -1)
  • the peak intensity ratio of the maximum peak in the range of 4320 ⁇ 20cm -1 (A4320cm -1) (A721cm -1 / A4320cm - 1 ) can be the “ethylene distribution parameter P”. From this “ethylene distribution parameter P”, the maximum value Pmax and the minimum value Pmin are obtained.
  • the ethylene distribution parameter P can be used as an index indicating the content of structural units derived from ethylene in the ethylene / ⁇ -olefin / non-conjugated polyene copolymer (A) in the measured fraction. It shows that there is so much content of the structural unit derived from ethylene that the ethylene distribution parameter P is large.
  • 721 ⁇ 20 cm the maximum peak in the range of -1 (A721cm -1) is estimated to show a peak derived from C-H rocking vibration of the constituent units derived from ethylene.
  • the maximum peak in the range of 4320 ⁇ 20cm -1 (A4320cm -1) is estimated to show a peak derived from C-H deformation vibration common to olefin backbone.
  • the flow activation energy of the ethylene / ⁇ -olefin / non-conjugated polyene copolymer is preferably 28 to 35 kJ / mol, more preferably 28 to 34 kJ / mol, and 28 to 33 kJ / mol. Is particularly preferred.
  • the flow activation energy (Ea) of the ethylene / ⁇ -olefin / non-conjugated polyene copolymer is an index indicating the degree of long-chain branching in the ethylene / ⁇ -olefin / non-conjugated polyene copolymer.
  • Flow activation energy will be described.
  • the viscosity of a polymer melt decreases with increasing temperature, as in a simple rheological liquid.
  • ⁇ 0 the temperature dependence of the viscosity ( ⁇ 0) follows an Arrhenius type equation represented by the following equation (i) at a temperature 100 ° C. higher than the glass transition temperature (Tg).
  • Viscosity ( ⁇ 0) Aexp (Ea / RT) (i) R: gas constant, A: frequency factor, Ea: flow activation energy, T: absolute temperature
  • the activation energy of flow does not depend on the molecular weight and molecular weight distribution, and is influenced only by the molecular structure, so it is a useful index representing the structural information of the polymer.
  • the copolymerized diene component is uniformly distributed in the molecular structure of the ethylene / ⁇ -olefin / non-conjugated polyene copolymer.
  • An ethylene / ⁇ -olefin / non-conjugated polyene copolymer having flow activation energy within the above range can be obtained by uniformly introducing a diene component into the polymer using a metallocene catalyst described later.
  • a metallocene catalyst described later for example, by increasing or decreasing the copolymerization ratio of a non-conjugated polyene having a terminal double bond such as 5-vinyl-2-norbornene (VNB), the introduction ratio of long chain branching is changed, and the flow activation energy is desired. Adjust to the value of.
  • VNB 5-vinyl-2-norbornene
  • the activation energy (Ea) of the flow is a master curve indicating the frequency (unit: rad / s) dependence of the melt complex viscosity (unit: Pa ⁇ s) at 190 ° C. based on the temperature-time superposition principle. It is a numerical value calculated by an Arrhenius type equation from the shift factor (aT) at the time of creation.
  • the method for obtaining the activation energy (Ea) of flow is shown. From the melt complex viscosity-frequency curve of ethylene / ⁇ -olefin / nonconjugated polyene copolymer at temperatures of 170 ° C. and 210 ° C. (T (° C.)), ethylene
  • the shift factor (aT) is obtained by superposing on the melt complex viscosity-frequency curve of the ⁇ -olefin / non-conjugated polyene copolymer. From each temperature (T) and the shift factor (aT) at that temperature (T), a linear approximation formula (I) of [ln (aT)] and [1 / (T + 273.16)] by the method of least squares. ) Is calculated. Next, the flow activation energy (Ea) can be obtained from the calculated slope m of the primary approximation formula (I) and the following formula (II).
  • the above calculation can be performed, for example, using commercially available calculation software (trade name “RSI Orchestrator VER.6.6.3” manufactured by T.A. Instrument Japan Co., Ltd.).
  • the logarithmic curve of the melt complex viscosity-frequency at each temperature (T) moves the frequency aT times and the melt complex viscosity 1 / aT times.
  • the correlation coefficient when the first order approximation (I) obtained from the shift factor (aT) at temperatures of 170 ° C., 190 ° C., and 210 ° C. and the temperature is obtained by the method of least squares is usually 0.99. That's it.
  • the melt complex viscosity-frequency curve is created by measurement using a viscoelasticity measuring apparatus shown below.
  • the test piece is a 2 mm thick sheet obtained by pressing an ethylene / ⁇ -olefin / non-conjugated polyene copolymer at 190 ° C. and punched into a disk shape having a diameter of 25 mm.
  • the test piece may contain an appropriate amount (for example, about 1000 ppm) of an antioxidant.
  • Viscoelasticity measuring device Trade name “RDS-2” (Rheometric) Measurement condition: Geometry: Parallel plate Measurement temperature: 170 ° C, 190 ° C, 210 ° C Frequency: 0.5-79.577Hz Distortion rate: 1.0%
  • the copolymer having the specific flow activation energy (Ea) may be prepared by adjusting the content of the non-conjugated polyene unit in the ethylene / ⁇ -olefin / non-conjugated polyene copolymer. it can.
  • the molecular weight distribution Mw / Mn of the ethylene / ⁇ -olefin / non-conjugated polyene copolymer expressed by the ratio of the weight average molecular weight (Mw) and the number average molecular weight (Mn) measured by gel permeation chromatography (GPC) is 1.2 to 3.5, preferably 1.7 to 3.0, more preferably 1.7 to 2.7, and more preferably 1. to 2.7. A range of 9 to 2.4 is particularly preferable.
  • the molecular weight distribution Mw / Mn can be adjusted to a desired range by producing an ethylene / ⁇ -olefin / non-conjugated polyene copolymer by a polymerization reaction using a metallocene compound (described later).
  • the resin containing the copolymer whose Mw / Mn is less than 1.2 has a narrow moldable temperature range, and it is difficult to make the discharge amount with an extruder uniform. Therefore, it is difficult to obtain a sheet having a uniform thickness, and sheet forming tends to be difficult.
  • the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) (Mw / Mn) was determined using a gel permeation chromatograph (trade name “Alliance GPC-2000”) manufactured by Waters as follows. To measure. For the separation column, two trade names “TSKgel GMH6-HT” and two trade names “TSKgel GMH6-HTL” were used.
  • the column size is 7.5 mm in inner diameter and 300 mm in length, the column temperature is 140 ° C., the mobile phase is o-dichlorobenzene (manufactured by Wako Pure Chemical Industries) and BHT (manufactured by Takeda Pharmaceutical Co., Ltd.) as an antioxidant.
  • the content ratio of chlorine ions detected by ion chromatography from the extract after solid-phase extraction treatment of the ethylene / ⁇ -olefin / non-conjugated polyene copolymer is preferably 2 ppm or less, and 1.5 ppm or less. More preferably, it is 1.2 ppm or less.
  • the content ratio of chloride ions can be adjusted by adjusting the structure of the metallocene compound described below and the polymerization conditions. That is, by increasing the polymerization activity of the polymerization catalyst, the amount of catalyst residue in the ethylene / ⁇ -olefin / non-conjugated polyene copolymer is reduced, and the content of chlorine ions is in the above numerical range.
  • An olefin / non-conjugated polyene copolymer can be obtained. Further, by using a metallocene compound containing no chlorine atom, an ethylene / ⁇ -olefin / non-conjugated polyene copolymer substantially free of chlorine ions can be obtained.
  • the electrode of the solar cell element (comprised of silver, etc.) is corroded, and the long-term reliability of the solar cell module May be reduced.
  • the content ratio of chlorine ions in the ethylene / ⁇ -olefin / non-conjugated polyene copolymer is about 10 g of ethylene / ⁇ -olefin / non-conjugated polyene copolymer in a glass container sterilized and cleaned using, for example, an autoclave. After precisely weighing and sealing with 100 ml of ultrapure water, an extract obtained by ultrasonic (38 kHz) extraction at room temperature for 30 minutes was used, and an ion chromatograph apparatus (trade name “ICS-” manufactured by Dionex Co., Ltd.) was used. 2000 ").
  • the amount of ethylene / ⁇ -olefin / non-conjugated polyene copolymer extracted into methyl acetate is preferably 5.0% by weight or less, more preferably 4.0% by weight or less, and 3.5% by weight. % Or less is more preferable, and 2.0% by weight or less is particularly preferable.
  • a large amount of extraction into methyl acetate indicates that the ethylene / ⁇ -olefin / non-conjugated polyene copolymer contains a large amount of low molecular weight components and broadens the molecular weight distribution or composition distribution.
  • an ethylene / ⁇ -olefin / non-conjugated polyene copolymer with a small amount of extraction into methyl acetate can be obtained.
  • the metallocene compound having reduced polymerization activity is removed from the polymerization system by shortening the polymerization residence time in the polymerization vessel, the production of low molecular weight components can be suppressed.
  • the extraction amount to methyl acetate in the Soxhlet extraction method is more than 5.0% by weight, the sheet is sticky and blocked, and the sheet feeding property tends to deteriorate.
  • the metallocene compound having reduced polymerization activity is removed from the outside of the polymerization system by shortening the polymerization residence time in the polymerization vessel, the production of low molecular weight components can be suppressed.
  • the extraction amount to methyl acetate in the Soxhlet extraction method is more than 5.0% by weight, the sheet is sticky and blocked, and the sheet feeding property tends to deteriorate.
  • the composition distribution becomes wider as the molecular weight distribution Mw / Mn becomes wider. Furthermore, since the low molecular weight bleeds to the sheet surface, the sheet adhesiveness decreases.
  • the amount extracted into methyl acetate is, for example, about 10 g of ethylene / ⁇ -olefin / non-conjugated polyene copolymer, precisely weighed, added to methyl acetate, and subjected to Soxhlet extraction at a temperature equal to or higher than the boiling point of the solvent. Calculated from the weight difference of the ⁇ -olefin / non-conjugated polyene copolymer or the amount of residue obtained by volatilizing the extraction solvent.
  • the melting peak of the ethylene / ⁇ -olefin / non-conjugated polyene copolymer based on differential scanning calorimetry (DSC) is preferably in the range of 30 to 90 ° C., and preferably in the range of 33 to 90 ° C. More preferably, it is particularly preferably in the range of 30 to 88 ° C.
  • the melting peak exceeds 90 ° C., the degree of crystallinity is high, the flexibility of the resulting solar cell encapsulant is low, and cracking of cells and chipping of thin film electrodes occur when a solar cell module is laminated. There is a case.
  • the resin composition is too flexible and it may be difficult to obtain a solar cell encapsulant sheet by extrusion. Further, stickiness occurs in the sheet and the sheet is blocked, and the sheet feeding property tends to deteriorate.
  • the ethylene / ⁇ -olefin / non-conjugated polyene copolymer preferably has low crystallinity, and more preferably has a crystallinity of 40% or less as measured by an X-ray diffraction method.
  • the ⁇ -olefin content may be increased.
  • it is desirable that the ethylene / ⁇ -olefin / non-conjugated polyene copolymer has a lower crystallinity than completely amorphous. This is because the low crystalline ethylene / ⁇ -olefin / non-conjugated polyene copolymer has excellent flexibility and transparency.
  • the ethylene / ⁇ -olefin / non-conjugated polyene copolymer can be produced by a polymerization reaction using various metallocene compounds shown below as catalysts.
  • the metallocene compounds are described in, for example, JP-A-2006-077261, JP-A-2008-231265, JP-A-2005-314680, JP-A-2009-138076, and the like.
  • a metallocene compound having a structure different from that of the metallocene compounds described in these patent documents may be used, or two or more metallocene compounds may be used in combination.
  • the monomer is supplied in the presence of an olefin polymerization catalyst comprising at least one kind of compound (also referred to as cocatalyst (II)).
  • the organoaluminum oxy compound (II-1), the compound (II-2) that forms an ion pair with the metallocene compound (I), and the organoaluminum compound (II-3) are disclosed in, for example, JP-A-2006-077261, Although described in Japanese Patent Application Laid-Open No. 2008-231265 and Japanese Patent Application Laid-Open No. 2005-314680, it is not particularly limited.
  • These cocatalysts (II) may be put into the polymerization atmosphere individually or in advance. Further, for example, it may be used by being supported on a particulate inorganic oxide support described in JP-A-2005-314680.
  • an ethylene / ⁇ -olefin / non-conjugated polyene copolymer having excellent electrical properties can be obtained by polymerizing the compound (II-2) that forms an ion pair with the metallocene compound (I). Obtainable.
  • the metal component and ion content of a polymer produced by a polymerization system using a conventionally known Ziegler-Natta catalyst and an organoaluminum compound (II-3) should be reduced by decalcification treatment with acid or the like. Can do. Thereby, an ethylene / ⁇ -olefin / non-conjugated polyene copolymer having excellent electrical properties can be obtained.
  • the acid or alkali remaining in the deashed ethylene / ⁇ -olefin / non-conjugated polyene copolymer is used as a solar cell encapsulant, it tends to corrode the electrodes of the solar cell module. Further, the decalcification treatment increases the production cost of the ethylene / ⁇ -olefin / non-conjugated polyene copolymer.
  • the ethylene / ⁇ -olefin / non-conjugated polyene copolymer is at least one selected from the group consisting of a metallocene compound (I), an organoaluminum oxy compound (II-1), and an organoaluminum compound (II-3). It is preferable to manufacture using the catalyst for olefin polymerization which consists of these compounds.
  • the polymerization reaction of the ethylene / ⁇ -olefin / non-conjugated polyene copolymer can be carried out by any of the conventionally known gas phase polymerization methods and liquid phase polymerization methods such as slurry polymerization methods and solution polymerization methods. It is carried out by a liquid phase polymerization method such as a solution polymerization method.
  • the amount of the metallocene compound (I) in the system is usually 10 ⁇ 9 to 10 ⁇ 1 mol, preferably 10 ⁇ 8 to 10 ⁇ 2 mol, per liter of reaction volume.
  • the amount of the compound (II-1) in the reaction system is such that the molar ratio [(II-1) / M] of the compound (I) to all transition metal atoms (M) is 1 to 10,000, preferably 10 to 5000. To be adjusted.
  • the amount of the compound (II-2) in the reaction system is such that the molar ratio [(II-2) / M] of the compound (I) to the total transition metal (M) is 0.5 to 50, preferably 1 to 20. It is adjusted to become.
  • the amount of compound (II-3) in the reactor is adjusted to 0 to 5 mmol, preferably about 0 to 2 mmol, per liter of polymerization volume.
  • ⁇ -olefin having 3 to 20 carbon atoms and a nonconjugated polyene By copolymerizing ethylene, an ⁇ -olefin having 3 to 20 carbon atoms and a nonconjugated polyene in the presence of a metallocene compound by a solution polymerization method, ethylene having a high comonomer content, a narrow composition distribution, and a narrow molecular weight distribution is obtained. -An ⁇ -olefin / non-conjugated polyene copolymer can be produced efficiently.
  • ⁇ -olefins having 3 to 20 carbon atoms and non-conjugated polyenes are as described above.
  • the ⁇ -olefin that can be used in the solution polymerization method may be a polar group-containing olefin.
  • polar group-containing olefins examples include ⁇ , ⁇ -unsaturated carboxylic acids such as acrylic acid, methacrylic acid, fumaric acid, maleic anhydride, and metal salts such as sodium salts thereof; methyl acrylate, ethyl acrylate, acrylic ⁇ , ⁇ -unsaturated carboxylic acid esters such as n-propyl acid, methyl methacrylate and ethyl methacrylate; vinyl esters such as vinyl acetate and vinyl propionate; unsaturated glycidyls such as glycidyl acrylate and glycidyl methacrylate And so on.
  • carboxylic acids such as acrylic acid, methacrylic acid, fumaric acid, maleic anhydride, and metal salts such as sodium salts thereof
  • methyl acrylate, ethyl acrylate, acrylic ⁇ , ⁇ -unsaturated carboxylic acid esters such as n-propyl acid, methyl
  • Vinylcyclohexane, diene, or polyene aromatic vinyl compounds such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o, p-dimethylstyrene, methoxystyrene, vinylbenzoic acid, vinylbenzoic acid Styrenes such as methyl acid, vinyl benzyl acetate, hydroxystyrene, p-chlorostyrene, divinylbenzene; 3-phenylpropylene, 4-phenylpropylene, ⁇ -methylstyrene, etc. coexist in the reaction system and subjected to high-temperature solution polymerization. Also good.
  • Solution polymerization method is a general term for methods in which polymerization is performed in a state where a solute is dissolved in an inert hydrocarbon solvent described later.
  • the polymerization temperature in the solution polymerization method is usually 0 to 200 ° C., preferably 20 to 190 ° C., more preferably 40 to 180 ° C.
  • the polymerization temperature is less than 0 ° C. in the solution polymerization method, the polymerization activity is extremely lowered, and it is difficult to remove the heat of polymerization, which is not practical in terms of productivity.
  • the polymerization temperature exceeds 200 ° C., the polymerization activity is extremely lowered, so that it is not practical in terms of productivity.
  • the polymerization pressure in the solution polymerization method is usually normal pressure to 10 MPa gauge pressure, preferably normal pressure to 8 MPa gauge pressure.
  • the copolymerization reaction may be carried out by any of batch, semi-continuous and continuous methods.
  • the reaction time (“average residence time” in the case of a continuous process) varies depending on conditions such as the catalyst concentration and the polymerization temperature, and can be selected as appropriate, but is usually 1 minute to 3 hours, preferably 10 minutes to 2 .5 hours.
  • the polymerization reaction may be performed in two or more stages having different reaction conditions.
  • the molecular weight of the obtained ethylene / ⁇ -olefin / non-conjugated polyene copolymer can also be adjusted by changing the hydrogen concentration or polymerization temperature in the polymerization system. Further, it can be adjusted by the amount of the cocatalyst (II). In the case of adding hydrogen, the amount of hydrogen added is suitably about 0.001 to 5,000 NL per kg of the ethylene / ⁇ -olefin / non-conjugated polyene copolymer to be produced.
  • the amount of vinyl groups and vinylidene groups present at the molecular ends of the obtained ethylene / ⁇ -olefin / nonconjugated polyene copolymer is adjusted by increasing the polymerization temperature and decreasing the amount of hydrogenation as much as possible. .
  • the solvent used in the solution polymerization method is usually an inert hydrocarbon solvent, preferably a saturated hydrocarbon having a boiling point of 50 to 200 ° C. under normal pressure.
  • 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.
  • Aromatic hydrocarbons such as benzene, toluene and xylene, and halogenated hydrocarbons such as ethylene chloride, chlorobenzene and dichloromethane are also “inert hydrocarbon solvents”, and they may be used.
  • a modified methyl such as MMAO that dissolves in an aliphatic hydrocarbon or an alicyclic hydrocarbon as well as an organic aluminum oxy compound that dissolves in an aromatic hydrocarbon conventionally used.
  • Aluminoxane may be used. If the solvent for solution polymerization is an aliphatic hydrocarbon or alicyclic hydrocarbon, there will be no aromatic hydrocarbon in the polymerization reaction system, and the resulting ethylene / ⁇ -olefin / nonconjugated polyene copolymer will be aromatic. The possibility of hydrocarbon contamination can be almost completely eliminated. Thereby, the solution polymerization method can be a method that can reduce the environmental load and minimize the influence on human health.
  • the ethylene / ⁇ -olefin / non-conjugated polyene copolymer obtained by the polymerization reaction and other components added as required are melted by any method, kneaded and granulated. Etc. are preferably applied.
  • the solar cell encapsulant of the present invention comprises an ethylene-based resin composition; the ethylene-based resin composition includes 100 parts by weight of the aforementioned ethylene / ⁇ -olefin / non-conjugated polyene copolymer and an ethylenically unsaturated silane compound. It is preferable that 0.1 to 5.0 parts by weight of a silane coupling agent such as, and 0.1 to 2.5 parts by weight of a crosslinking agent such as an organic peroxide are included.
  • the ethylene-based resin composition contains 0.1 to 4 parts by weight of ethylenically unsaturated silane compound and 0% of organic peroxide with respect to 100 parts by weight of ethylene / ⁇ -olefin / non-conjugated polyene copolymer. 2 to 2.5 parts by weight is preferably contained; 0.1 to 3 parts by weight of the ethylenically unsaturated silane compound is added to 100 parts by weight of the ethylene / ⁇ -olefin / nonconjugated polyene copolymer; More preferably, 0.2 to 2 parts by weight of oxide is contained.
  • (Ethylenically unsaturated silane compound) Adhesiveness falls that the ethylenically unsaturated silane compound in an ethylene-type resin composition is less than 0.1 weight part. On the other hand, if the ethylenically unsaturated silane compound in the ethylene-based resin composition is more than 5 parts by weight, the balance between the cost and performance of the solar cell encapsulant becomes worse. Furthermore, when the amount of the ethylenically unsaturated silane compound in the ethylene resin composition is excessive, the amount of the organic peroxide in the ethylene resin composition must be increased.
  • a conventionally well-known thing can be used for an ethylenically unsaturated silane compound, and there is no restriction
  • Specific examples include vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris ( ⁇ -methoxyethoxysilane), ⁇ -glycidoxypropyltrimethoxysilane, ⁇ -aminopropyltriethoxysilane, ⁇ -methacryloxypropyltrimethoxysilane. Etc. are included.
  • it can be ⁇ -glycidoxypropylmethoxysilane, ⁇ -aminopropyltriethoxysilane, ⁇ -methacryloxypropyltrimethoxysilane, vinyltriethoxysilane, etc., which can enhance the adhesiveness of the ethylene resin composition. .
  • Organic peroxide acts as a radical initiator for graft-modifying the ethylene / ⁇ -olefin / non-conjugated polyene copolymer with an ethylenically unsaturated silane compound. Further, the organic peroxide acts as a radical initiator for cross-linking the ethylene / ⁇ -olefin / non-conjugated polyene copolymer when a solar cell sealing material is laminated to obtain a solar cell module.
  • the adhesion between the sealing layer and the glass, backsheet, solar cell element, and electrode in the solar cell module Will increase.
  • the sealing member excellent in heat resistance and adhesiveness can be formed in the solar cell module by crosslinking the ethylene / ⁇ -olefin / non-conjugated polyene copolymer.
  • the content of the organic peroxide in the ethylene-based resin composition is less than 0.1 part by weight, the crosslinking property such as the crosslinking degree and crosslinking rate of the solar cell encapsulating material is reduced, and the ethylenically unsaturated silane compound
  • the graft reaction to the main chain of the ethylene / ⁇ -olefin / non-conjugated polyene copolymer becomes insufficient, resulting in a decrease in heat resistance and adhesion.
  • the adhesiveness with glass, a solar cell element, an electrode, and a backsheet deteriorates at the time of a lamination process of a solar cell module, and adhesiveness also falls. Furthermore, since the crosslinking at the time of laminate molding of the solar cell module proceeds too much, the thermal contraction becomes large, and the end of the solar cell module is not sufficiently embedded with the solar cell sealing material, or the thermal contraction is too large. The element may break. If the crosslinking proceeds excessively, deterioration of the ethylene / ⁇ -olefin / non-conjugated polyene copolymer also proceeds and heat resistance, color tone and flexibility may be deteriorated.
  • the organic peroxide can be obtained by graft-modifying an ethylene / ⁇ -olefin / non-conjugated polyene copolymer with an ethylenically unsaturated silane compound and crosslinking the ethylene / ⁇ -olefin / non-conjugated polyene copolymer. Anything is possible.
  • an organic peroxide having a one-minute half-life temperature of 100 to 170 ° C. is preferred from the balance between productivity in extrusion molding and a crosslinking rate in lamination of a solar cell module.
  • An organic peroxide having a half-life temperature of less than 100 ° C. for 1 minute generates gel in the solar cell encapsulating sheet obtained from the resin composition at the time of extrusion sheet molding, and increases the torque of the extruder, making sheet molding difficult. There is a case.
  • the surface of the obtained sheet may be uneven due to the gel material generated in the extruder, and the sheet appearance may deteriorate. Further, when a voltage is applied to the sheet, cracks are generated around the gel material, and the dielectric breakdown resistance is reduced. Furthermore, moisture permeation at the gel object interface is likely to occur and moisture permeability is reduced.
  • the adhesiveness with glass, a solar cell element, an electrode, and a back sheet deteriorates at the time of a lamination process of a solar cell module, and adhesiveness also falls.
  • the organic peroxide reacts to promote cross-linking of the solar cell encapsulant, resulting in decreased fluidity during laminating or ethylenically unsaturated silane. In some cases, the amount of organic peroxide used as an initiator for the grafting reaction of the compound is reduced, resulting in a decrease in adhesion.
  • the organic peroxide having a half-life temperature of more than 170 ° C. for 1 minute slows the crosslinking rate of the solar cell encapsulant when laminating the solar cell encapsulant and obtains the solar cell module.
  • Productivity is greatly reduced.
  • the heat resistance of a solar cell sealing material and adhesiveness are reduced.
  • organic peroxides can be used.
  • Preferred examples of organic peroxides having a 1 minute half-life temperature in the range of 100-170 ° C. include dilauroyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate.
  • dilauroyl peroxide t-butyl peroxyisopropyl carbonate, t-butyl peroxyacetate, t-butyl peroxyisononanoate, t-butyl peroxy-2-ethylhexyl carbonate, t-butyl peroxybenzoate, etc. Is mentioned.
  • the solar cell encapsulant of the present invention has a volume resistivity of 1.0 ⁇ 10 13 to 1.0 ⁇ 10 18 ⁇ ⁇ cm measured at a temperature of 100 ° C. and an applied voltage of 500 V in accordance with JIS K6911. Is preferred.
  • a solar cell encapsulant having a small volume resistivity tends to easily generate PID in the battery module.
  • the temperature of the conventional solar cell module may be, for example, 70 ° C. or higher in the time zone in which sunlight is irradiated. Therefore, in order to obtain long-term reliability of the module, the volume resistivity under a high temperature (for example, 100 ° C.) condition is more important than the volume resistivity at a normal temperature (23 ° C.).
  • the volume resistivity of the solar cell encapsulant is preferably 1.0 ⁇ 10 14 to 1.0 ⁇ 10 18 ⁇ ⁇ cm, more preferably 5.0 ⁇ 10 14 to 1.0 ⁇ 10 18 ⁇ ⁇ cm, Most preferably, it is 1.0 ⁇ 10 15 to 1.0 ⁇ 10 18 ⁇ ⁇ cm.
  • the volume resistivity is less than 1.0 ⁇ 10 13 ⁇ ⁇ cm, a PID phenomenon tends to occur in the solar cell module in a short period of about one day in a constant temperature and humidity test at 85 ° C. and 85% rh. .
  • a solar cell encapsulant having a volume resistivity exceeding 1.0 ⁇ 10 18 ⁇ ⁇ cm is easily charged with static electricity and easily adsorbs dust.
  • the solar cell encapsulant having a volume resistivity exceeding 5.0 ⁇ 10 14 ⁇ ⁇ cm has a time until the occurrence of the PID phenomenon of the solar cell module in the constant temperature and humidity test at 85 ° C. and 85% rh. This is desirable because it tends to be longer.
  • the volume resistivity of the solar cell encapsulant is measured after the sheet-molded encapsulant is processed into a cross-linked and flat sheet with a vacuum laminator, a hot press, a cross-linking furnace, or the like.
  • the sealing layer may be taken out from the solar cell module (that is, other layers are removed), and the volume specific resistance of the taken sealing layer may be measured.
  • the solar cell sealing material which is the 2nd form of this invention is (A) ethylene * alpha-olefin * diene copolymer, (B) paraffinic oil, (C) It consists of a resin composition containing a crosslinking agent and various additives such as an adhesion-imparting agent as required.
  • the ethylene / ⁇ -olefin / diene copolymer may be a random copolymer or a block copolymer.
  • Examples of the ⁇ -olefin of the ethylene / ⁇ -olefin / diene copolymer include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, and 3-methyl-1 pentene.
  • 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicocene and the like are included, and ⁇ -olefins having 3 to 10 carbon atoms are preferable.
  • dienes of ethylene / ⁇ -olefin / diene copolymers include 5-ethylidene-2-norbornene, 5-propylidene-5-norbornene, dicyclopentadiene, 5-vinyl-2-norbornene, 5- Cyclic dienes such as methylene-2-norbornene, 5-isopropylidene-2-norbornene, norbornadiene; 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 5-methyl Examples include chain-like nonconjugated dienes such as -1,5-heptadiene, 6-methyl-1,5-heptadiene, 6-methyl-1,7-octadiene, and 7-methyl-1,6-octadiene.
  • a part of the diene component may be a triene such as 2,3-diisopropylidene-5-norbornene and 4-ethylidene-8-methyl-1,7-nonadiene.
  • a triene such as 2,3-diisopropylidene-5-norbornene and 4-ethylidene-8-methyl-1,7-nonadiene.
  • 5-ethylidene-2-norbornene, dicyclopentadiene, 5-vinyl-2-norbornene and the like are preferable as the diene component from the viewpoint of moldability of the solar cell sealing film.
  • a typical example of an ethylene / ⁇ -olefin / diene copolymer is a copolymer having ethylene as a main component, ⁇ -olefin as a minor component, and diene as a minor component. Specific examples thereof include ethylene / propylene / dicyclopentadiene copolymer, ethylene / propylene / 5-ethylidene-2-norbornene copolymer, ethylene / propylene / vinyl norbornene copolymer, ethylene / 1-butene.
  • Examples thereof include a dicyclopentadiene copolymer, an ethylene / 1-butene / 5-ethylidene-2-norbornene copolymer, and an ethylene / 1-butene / vinyl norbornene copolymer.
  • an ethylene / propylene / diene copolymer (EPDM) is particularly preferable.
  • the content of the structural unit derived from ethylene in the ethylene / ⁇ -olefin / diene copolymer is preferably 50 to 95 mol%, more preferably 70 to 90 mol%, still more preferably 80 to 90 mol%.
  • the ethylene content is within the above range, there is an advantage that the transparency is excellent and the compression set at a low temperature is reduced.
  • the content of the structural unit derived from the ⁇ -olefin in the ethylene / ⁇ -olefin / diene copolymer is preferably 4.5 to 49.5 mol%, more preferably 9.5 to 29. 0.5 mol%, more preferably 9.5 to 19.5 mol%. If the ⁇ -olefin content is too small, the (A) ethylene / ⁇ -olefin / diene copolymer is likely to be crystallized, and the flexibility and transparency of the cured product are likely to be lowered.
  • the content of the structural unit derived from diene in the (A) ethylene / ⁇ -olefin / diene copolymer is preferably 0.5 to 5 mol%, more preferably 0.5 to 2 mol%. .
  • the diene content is within the above range, good heat resistance and weather resistance can be obtained.
  • Mooney viscosity ML (1 + 4) of the (A) ethylene / ⁇ -olefin / diene copolymer contained in the solar cell encapsulant of the second aspect of the present invention, measured at 100 ° C. according to ASTM D-1646 ) 100 ° C is preferably 30 to 90.
  • Mooney viscosity ML (1 + 4) 100 ° C. means a viscosity at 100 ° C. after preheating with an L rotor for 1 minute and shaking for 4 minutes. If the Mooney viscosity ML (1 + 4) 100 ° C.
  • the processing viscosity is too high. Hateful.
  • the crystallinity of the ethylene / ⁇ -olefin / diene copolymer is preferably low, and the crystallinity measured by the X-ray diffraction method is more preferably 40% or less.
  • the ⁇ -olefin content may be increased.
  • the (A) ethylene / ⁇ -olefin / diene copolymer has low crystallinity rather than complete amorphousness.
  • the (A) ethylene / ⁇ -olefin / diene copolymer preferably has a melting point of 70 ° C. or less as measured in accordance with JIS-K7121. This is because these (A) ethylene / ⁇ -olefin / diene copolymers are excellent in flexibility and transparency.
  • the ethylene / ⁇ -olefin / diene copolymer is composed of a vanadium catalyst composed of a soluble vanadium compound and an organic aluminum hydrite, or a metallocene compound such as a zirconium compound coordinated with a cyclopentadienyl group, and an organic aluminum oxy It can be produced by copolymerizing ethylene, ⁇ -olefin and diene in the presence of a metallocene catalyst comprising a compound.
  • the solar cell encapsulant of the second embodiment of the present invention may contain other resins in addition to (A) the ethylene / ⁇ -olefin / diene copolymer.
  • the (B) paraffinic oil contained in the solar cell encapsulant of the second aspect of the present invention is a mineral oil based oil whose main component is paraffin.
  • the paraffin content of the paraffinic oil is preferably 55 to 90% by weight, more preferably 65 to 90% by weight.
  • the content of the paraffin component is less than 55% by weight, the transparency of the cured product of the solar cell sealing material tends to be lowered.
  • the content of the paraffin component exceeds 90% by weight, the paraffin component may be precipitated. In particular, normal paraffin tends to precipitate.
  • the content of the naphthene component is preferably less than 40% by weight, and more preferably less than 35% by weight.
  • the naphthene component is 40% by weight or more, the crosslinking efficiency of the (A) ethylene / ⁇ -olefin / diene copolymer tends to decrease.
  • the transparency of the cured product of (A) ethylene / ⁇ -olefin / diene copolymer may be lowered.
  • the naphthene component content should be low, but extraction and removal of the naphthene component is costly.
  • the content of the aroma component is preferably less than 5% by weight, more preferably less than 1% by weight.
  • the transparency of the cured product of (A) ethylene / ⁇ -olefin / diene copolymer tends to be lowered.
  • compatibility with (A) ethylene / ⁇ -olefin / diene copolymer and crosslinking efficiency may be lowered.
  • the content of the paraffin component, naphthene component and aroma component of the paraffinic oil can be measured by a method based on ndM ring analysis ASTM D-2140.
  • the content of the sulfur component in the paraffinic oil is preferably less than 200 ppm, and more preferably less than 100 ppm. If the sulfur content is high, the crosslinking efficiency of the (A) ethylene / ⁇ -olefin / diene copolymer may be reduced, and the transparency and weather resistance stability of the cured product may be reduced (easily colored). Become).
  • (B) Content of the sulfur component of paraffinic oil is measured by the method based on JIS K2541.
  • the density of the paraffinic oil measured in accordance with JIS K2249 is preferably in the range of 859 to 887 kg / m 3 .
  • the density is in the above range, it is easy to adjust the melt viscosity of the resin composition to an appropriate range.
  • the kinematic viscosity at 40 ° C. of the paraffinic oil measured according to JIS K2283 is preferably 30 to 440 mm 2 / s.
  • the kinematic viscosity is in the above range, it is easy to adjust the melt viscosity of the resin composition to an appropriate range.
  • the pour point of the paraffinic oil measured according to JIS K2269 is preferably ⁇ 25 to ⁇ 5 ° C., more preferably about ⁇ 25 to ⁇ 10 ° C. When the pour point is in the above range, it is easy to adjust the melt viscosity of the resin composition to an appropriate range.
  • paraffinic oils examples include paraffinic process oils PW-100, PW-32, PW-90, PW-150, PW-360, PW-380, PS-32, PS manufactured by Idemitsu Kosan Co., Ltd. -90, PS-430, Nippon Sun Oil Co., Ltd. SUNPAR 115, 120, 150, 2100, 2280, Cosmo Oil Lubricants Co., Ltd. Cosmo Neutral 150, 350, 500, Matsumura Oil Co., Ltd.
  • the content of the paraffinic oil is set in consideration of the moldability and cross-linking characteristics of the resin composition. Specifically, if the content of the (B) paraffinic oil is too small, the moldability at the time of melting cannot be sufficiently increased, so that it is difficult to obtain an effect of improving the moldability; When there is too much content, the viscosity of a compound will fall too much and workability will fall. In addition, when the content of (B) paraffinic oil is too small, the dispersibility of the crosslinking agent is deteriorated, and when the content of (B) paraffinic oil is too large, the crosslinking agent is diluted. The characteristics may deteriorate.
  • the content of (B) paraffinic oil is such that the MFR at 190 ° C. and a load of 2.6 kg of a resin composition comprising (A) an ethylene / ⁇ -olefin / diene copolymer and (B) paraffinic oil is It is preferably set so as to exceed 10 g / 10 min and be 50 g / 10 min or less.
  • the MFR of the resin composition is less than 10 g / 10 min, since the viscosity at the time of melting is too high, the moldability is poor and it is difficult to obtain a sheet having a uniform film thickness.
  • the MFR of the resin composition exceeds 50 g / 10 min, since the viscosity at the time of melting is too low, it becomes easy to stick to the first roll, and it is difficult to obtain a sheet with a uniform film thickness.
  • FIG. 3 shows (B) the Mooney viscosity (y axis) of the resin composition before oil addition and the MFR (x axis) of the resin composition after oil addition when the content of paraffinic oil is changed. It is a graph which shows a relationship.
  • the preferable content of (B) paraffinic oil for making the MFR of the resin composition after oil addition over 10 g / 10 min and 50 g / 10 min or less is (A) ethylene ⁇ ⁇ -Mooney viscosity ML (1 + 4) of olefin-diene copolymer varies depending on 100 ° C.
  • the content of the system oil may be about 60 to 100 parts by weight with respect to 100 parts by weight of the (A) ethylene / ⁇ -olefin / diene copolymer.
  • the content of the (B) paraffinic oil in the resin composition may be set based on data as shown in FIG.
  • the crosslinking agent that can be added to the solar cell encapsulant according to the second aspect of the present invention is a solar cell by causing a polymer component contained in the solar cell encapsulant to undergo a crosslinking reaction.
  • the heat resistance and weather resistance of the sealing film can be improved.
  • the crosslinking agent is preferably an organic peroxide that generates radicals at 100 ° C. or higher.
  • an organic peroxide having a decomposition temperature of 100 to 150 ° C. with a half-life of 1 hour is used. More preferred.
  • organic peroxides as crosslinking agents include 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 3-di-t-butyl peroxide, t-dicumyl Peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne, dicumyl peroxide, ⁇ , ⁇ '-bis (t-butylperoxyisopropyl) benzene, n-butyl-4, 4-bis (t-butylperoxy) butane, 2,2-bis (t-butylperoxy) butane, 1,1-bis (t-butylperoxy) cyclohexane, tertiary butylperoxy-2-ethylhexyl carbonate 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane, t-butylperoxybenzoate, 1,6-di
  • the content of the crosslinking agent (C) in the solar cell encapsulant is preferably 0.01 to 5.0 parts by weight, and 0.1 to 4.0 parts by weight with respect to 100 parts by weight of the polymer component. It is more preferable that
  • the Shore A hardness of the solar cell encapsulant that is the second embodiment of the present invention is preferably 80 or less. This is because when the Shore A hardness of the solar cell sealing film is more than 80, the flexibility is low, and thus the solar cell is easily damaged when the solar cell sealing film and the solar cell are laminated.
  • the Shore A hardness of the solar cell encapsulant can be measured by a method based on JIS K6301.
  • the internal haze of the cured product of the solar cell encapsulant of the second aspect of the present invention is preferably 10% or less.
  • the total light transmittance of the cured product having a thickness of 0.5 mm of the solar cell encapsulant is preferably 80% or more, and more preferably 90% or more.
  • the internal haze and total light transmittance of the cured product were obtained by laminating (thermocompression bonding) the sample sheet (thickness 0.5 mm) of the solar cell sealing film of the present invention between a pair of white plate glasses to obtain a sample piece. After; the internal haze and total light transmittance of the sample piece can be determined by measuring with a Hitachi spectrophotometer U-3010 with 150 mm ⁇ integrating sphere.
  • the solar cell encapsulating material of the second aspect of the present invention comprises the above-described components (at least (A) an ethylene / ⁇ -olefin / diene copolymer, (B) a paraffinic oil and (C) a crosslinking agent). After mixing and kneading, they may be formed into a sheet shape.
  • each component may be carried out by simultaneously mixing the components (A) to (C); (A) an ethylene / ⁇ -olefin / diene copolymer and (B) a paraffinic oil. After kneading, the crosslinking agent (C) may be further mixed and kneaded.
  • the kneading means may be appropriately selected according to the film forming method, and examples thereof include a mixing roll, a Banbury mixer, a pressure kneader, a feeder ruder, and an extruder. When kneading with an extruder, the temperature of the barrel and the die may be set to a temperature that is equal to or higher than the melting point of the component (A) and can uniformly knead each component.
  • Examples of film forming methods include extrusion molding, calendering, and hot pressing. From the viewpoint of excellent productivity, when a large amount of oil and plasticizer are blended to obtain a particularly flexible composition.
  • the extrusion method is preferred from the viewpoint of ensuring good moldability even when the viscosity is lowered.
  • the temperature of the barrel and the die of the extruder is preferably 55 to 120 ° C.
  • the melt-kneaded product of the resin composition containing the ethylene / ⁇ -olefin / diene copolymer can obtain a sheet and a film having a stable and uniform surface state.
  • the thickness of the solar cell sealing film is, for example, about 100 ⁇ m to 2000 ⁇ m.
  • the sealing film for solar cells may be embossed on the surface in terms of improving cushioning properties and deaeration properties in the heat curing step.
  • the conventional ethylene polymer composition could not be processed by causing a melt fracture from a die heated at the time of extrusion, but the ethylene / ⁇ -olefin / diene copolymer composition of the present invention was melt melt fractured.
  • a smooth sheet or film can be obtained without causing any problems.
  • the ethylene resin composition constituting the solar cell encapsulant preferably contains at least one additive selected from the group consisting of ultraviolet absorbers, light stabilizers and heat stabilizers.
  • the blending amount of these additives is preferably 0.005 to 5 parts by weight, and 0.05 to 5 parts by weight with respect to 100 parts by weight of the ethylene / ⁇ -olefin / non-conjugated polyene copolymer. More preferably it is.
  • the ethylene-based resin composition preferably contains at least two kinds of additives selected from ultraviolet absorbers, light stabilizers and heat stabilizers, and particularly preferably contains all three kinds.
  • the blending amount of the additive is in the above range, the effect of improving resistance to constant temperature and humidity, heat cycle resistance, weather resistance stability, and heat stability is sufficiently secured, and a solar cell sealing material This is preferable because it can prevent the deterioration of the transparency and the adhesiveness with glass, backsheet, solar cell element, electrode and aluminum.
  • the ultraviolet absorber examples include 2-hydroxy-4-normaloctyloxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2-dihydroxy-4-methoxybenzophenone, and 2-hydroxy-4-methoxy-4- Benzophenone series such as carboxybenzophenone, 2-hydroxy-4-N-octoxybenzophenone; 2- (2-hydroxy-3,5-di-t-butylphenyl) benzotriazole, 2- (2-hydroxy-5-methyl) Benzotrializoles such as phenyl) benzotriazole; salicylic acid esters such as phenylsalicylate and p-octylphenylsalicylate are used.
  • light stabilizers examples 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 the like, hindered amine compounds, hindered piperidine compounds and the like are included.
  • heat stabilizers include tris (2,4-di-tert-butylphenyl) phosphite, bis [2,4-bis (1,1-dimethylethyl) -6-methylphenyl] ethyl ester phosphorus Acids, tetrakis (2,4-di-tert-butylphenyl) [1,1-biphenyl] -4,4′-diylbisphosphonite, and bis (2,4-di-tert-butylphenyl) pentaerythritol Phosphite heat stabilizers such as diphosphites; lactone heat stabilizers such as reaction products of 3-hydroxy-5,7-di-tert-butyl-furan-2-one with o-xylene; 3 ′, 3 ′′, 5,5 ′, 5 ′′ -hexa-tert-butyl-a, a ′, a ′′-(methylene-2,4,6-triy
  • the ethylene resin composition constituting the solar cell encapsulant can further contain other components as long as the object of the present invention is not impaired.
  • examples include various polyolefins other than ethylene / ⁇ -olefin / non-conjugated polyene copolymers, styrene-based, ethylene-based block copolymers, and propylene-based polymers. These may be contained in an amount of 0.0001 to 50 parts by weight, preferably 0.001 to 40 parts by weight, based on 100 parts by weight of the ethylene / ⁇ -olefin / non-conjugated polyene copolymer.
  • the above additives can be appropriately contained.
  • the blending amount of the crosslinking aid in the ethylene-based resin composition is 0.05 to 5 parts by weight with respect to 100 parts by weight of the ethylene / ⁇ -olefin / non-conjugated polyene copolymer, and more preferably 0. 2 to 4.0 parts by weight.
  • a blending amount of the crosslinking aid in the above range is preferable because it can have an appropriate crosslinked structure and can improve heat resistance, mechanical properties, and adhesiveness.
  • the crosslinking aid is a conventionally known crosslinking aid generally used in olefinic resins.
  • the crosslinking aid has a double bond in the molecule.
  • Specific examples of the crosslinking aid include monoacrylates such as t-butyl acrylate, lauryl acrylate, cetyl acrylate, stearyl acrylate, 2-methoxyethyl acrylate, ethyl carbitol acrylate, methoxytripropylene glycol acrylate; t-butyl methacrylate, lauryl Monomethacrylates such as methacrylate, cetyl methacrylate, stearyl methacrylate, methoxyethylene glycol methacrylate, methoxypolyethylene glycol methacrylate; 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, neo Pentyl glycol diacrylate,
  • triacrylates such as diacrylate, dimethacrylate, divinyl aromatic compound, trimethylolpropane triacrylate, tetramethylolmethane triacrylate, pentaerythritol triacrylate; trimethylolpropane trimethacrylate , Trimethacrylates such as trimethylolethane trimethacrylate; tetraacrylates such as pentaerythritol tetraacrylate and tetramethylolmethane tetraacrylate; cyanurates such as triallyl cyanurate and triallyl isocyanurate; diallyl compounds such as diallyl phthalate; triallyl compound: p Oximes such as -quinonedioxime and pp'-dibenzoylquinonedioxime: m-phenylmale Maleimides such as de, is a 1,2-polybutadiene.
  • the ethylene resin composition contained in the solar cell encapsulant has a time (Tc90) to reach 90% of the maximum torque value measured at 150 ° C. with a curast meter at a reversal speed of 100 cpm (Tc90). It is also preferable that it is 8 to 13 minutes, more preferably 9 to 12 minutes.
  • Tc90 is less than 8 minutes, gelation occurs when the solar cell encapsulant is obtained in the form of a sheet with an extruder, unevenness is generated on the surface of the resulting sheet, etc., and the torque of the extruder is increased to form a sheet. May be difficult.
  • produces on the surface of a sheet
  • a voltage is applied, cracks are generated around the gel within the sheet, and the dielectric breakdown resistance is reduced.
  • moisture permeation at the gel object interface is likely to occur and moisture permeability is reduced.
  • produces on the sheet
  • Tc90 exceeds 14 minutes, the time required for crosslinking during lamination of the solar cell module becomes long, and the manufacturing time of the solar cell module tends to be long.
  • the ethylene resin composition contained in the solar cell encapsulant is kneaded in a microrheology compounder at 120 ° C. and 30 rpm, and the time taken to increase by 0.1 Nm from the minimum torque value is 10 to 100 minutes. It is also preferably 10 to 90 minutes, more preferably 10 to 80 minutes.
  • the time of 0.1 Nm increase from the minimum torque value is less than 10 minutes, gelation occurs when the solar cell encapsulant is obtained in the form of a sheet with an extruder, and the torque of the extruder increases, making it difficult to form a sheet. It may become.
  • produces on the surface of a sheet
  • when a voltage is applied cracks are generated around the gel within the sheet, and the dielectric breakdown resistance is reduced.
  • moisture permeation at the gel object interface is likely to occur and moisture permeability is reduced.
  • produces on the sheet
  • the solar cell encapsulant of the present invention is excellent in the balance of adhesiveness with various solar cell members, transparency, flexibility, heat resistance, extrusion moldability, and crosslinking characteristics.
  • the solar cell member include glass, a back sheet, a thin film electrode, aluminum, a solar cell element, and the like.
  • the solar cell encapsulant of the present invention is excellent in weather resistance, volume resistivity, electrical insulation, moisture permeability, electrode corrosion, and process stability. For this reason, it is used suitably as a solar cell sealing material of a solar cell module.
  • the solar cell encapsulant of the present invention can be produced by melt blending each component by a usual method such as a kneader, a Banbury mixer, an extruder, a calendar molding machine or the like. Especially, it is preferable to melt-blend each component with an extruder.
  • the solar cell encapsulant has a sheet shape as a whole. Further, the solar cell encapsulant may be a laminate composed of a plurality of layers, at least one of which is composed of the above-described ethylene-based resin composition.
  • the thickness of the sheet-like solar cell encapsulant is usually 0.01 to 2 mm, preferably 0.05 to 1.5 mm, more preferably 0.1 to 1.2 mm, particularly preferably 0.2 to 1 mm. More preferably, it is 0.3 to 0.9 mm, and most preferably 0.3 to 0.8 mm.
  • a solar cell encapsulant within this thickness range is less likely to damage glass, solar cell elements, thin film electrodes, etc. when laminated to form a solar cell module; and because sufficient light transmittance is ensured.
  • the photovoltaic power generation amount of the solar cell can be increased.
  • the lamination process for obtaining a solar cell module can be performed at a low temperature.
  • the method of forming the solar cell encapsulant sheet there is no particular limitation on the method of forming the solar cell encapsulant sheet, and various known forming methods (cast molding, extrusion sheet molding, inflation molding, injection molding, compression molding, etc.) can be employed.
  • various known forming methods cast molding, extrusion sheet molding, inflation molding, injection molding, compression molding, etc.
  • ethylene / ⁇ -olefin / non-conjugated polyene copolymer ethylenically unsaturated silane compound, organic peroxide, UV absorber, light stabilizer, heat stabilizer, and other as required
  • a sheet-shaped solar cell encapsulant is obtained by extrusion sheet molding while melt kneading with the additive.
  • Extrusion temperature range is 90-130 ° C. If the extrusion temperature is less than 90 ° C., molding is possible, but the productivity is greatly reduced. When the extrusion temperature exceeds 130 ° C., the ethylene-based resin composition contained in the solar cell encapsulant is formed into a sheet with an extruder to cause gelation, and the extruder torque increases. Sheet molding may be difficult. Moreover, unevenness
  • the surface of the sheet-shaped solar cell encapsulant may be embossed.
  • embossing the surface of the solar cell encapsulant By embossing the surface of the solar cell encapsulant, blocking between the encapsulating sheets or between the encapsulating sheet and other sheets can be prevented. Further, since the embossing reduces the storage elastic modulus of the solar cell sealing material, it becomes a cushion for the solar cell element when laminating the solar cell sealing material and the solar cell element, and the solar cell element is damaged. Can be prevented.
  • Porosity expressed as a percentage V H / V A ⁇ 100 of the total volume VH of the recesses per unit area of the sheet-like solar cell encapsulant and the apparent volume VA of the sheet-like solar cell encapsulant P (%) is preferably 10 to 50%, more preferably 10 to 40%, and further preferably 15 to 40%.
  • the apparent volume VA of the sheet-shaped solar cell encapsulant is obtained by multiplying the unit area by the maximum thickness of the solar cell encapsulant.
  • the porosity of the sheet-shaped solar cell encapsulant is less than 10%, even if pressure is applied to a part of the solar cell encapsulant, the part of the embossed convex portion is not deformed. For this reason, in the lamination process of the solar cell module, a large pressure is applied to a part of the crystalline solar cell element, and the crystalline solar cell element is cracked. Further, in the two-step laminating process (pressing process) of the solar cell module, the crystal solar cell element itself or the solder for fixing the crystal solar cell element and the electrode is damaged; the silver electrode in the thin film solar cell is damaged Sometimes.
  • the porosity of the sheet-like solar cell encapsulant is less than 10%, there are few air passages, resulting in poor deaeration during the laminating process. For this reason, air remains in the solar cell module and the appearance is deteriorated; during long-term use, the electrode may be corroded by moisture remaining in the air. Furthermore, since the flowing ethylene-based resin composition does not fill the gap during the laminating process, it may protrude outside the respective adherends of the solar cell module and contaminate the laminator.
  • the porosity P of the sheet-like solar cell encapsulant is greater than 80%, it is not possible to completely deaerate air during the laminating process, and air tends to remain in the solar cell module. For this reason, the external appearance of a solar cell module deteriorates, or at the time of long-term use, corrosion of an electrode is caused by moisture in the remaining air. Moreover, since all the air cannot be deaerated at the time of pressurization of the lamination process, the adhesion area between the solar cell sealing material and the adherend is reduced, and sufficient adhesion strength cannot be obtained.
  • the porosity P can be obtained by the following calculation.
  • V A (mm 3 ) t max (mm) ⁇ 10 6 (mm 2 ) (3)
  • the actual volume V 0 (mm 3 ) of the solar cell encapsulant of this unit area is based on the specific gravity ⁇ (g / mm 3 ) and unit area (1 m 2 ) of the resin constituting the solar cell encapsulant.
  • V H (mm 3 ) W / ⁇ (4)
  • the total volume V H (mm 3 ) of the recesses per unit area of the solar cell encapsulant is expressed as “actual volume V A of the solar cell encapsulant” to “actual volume” as shown in the following formula (5). It is calculated by subtracting the volume “V 0 ”.
  • the porosity (%) may be obtained by taking a micrograph of the cross section or embossed surface of the solar cell encapsulant and performing image processing.
  • the depth of the embossed recess is preferably 20 to 95% of the maximum thickness of the solar cell encapsulant, more preferably 50 to 95%, and more preferably 65 to 95%.
  • the percentage of the depth D of the recess with respect to the maximum thickness t max of the sheet may be referred to as the “depth ratio” of the recess.
  • the depth of the concave portion of the emboss refers to the height difference D between the topmost portion of the convex portion and the deepest portion of the concave portion of the uneven surface of the solar cell sealing material by embossing.
  • the maximum thickness t max of the solar cell encapsulating material means that when embossing is performed on one surface of the solar cell encapsulating material, the solar cell encapsulating material from the top of one convex portion to the other surface (solar cell encapsulating The distance (in the thickness direction); when embossed on both sides of the solar cell encapsulant, from the top of the convex on one side to the top of the other The distance (in the thickness direction of the stop material).
  • Embossing may be performed only on one side of the solar cell encapsulant or on both sides.
  • embossing is preferably performed only on one side of the solar cell encapsulant.
  • the maximum thickness t max of the solar cell encapsulant is 0.01 mm to 2 mm, preferably 0.05 to 1 mm, more preferably 0.1 to 1 mm, more preferably 0.15 mm to 1 mm, further preferably 0.2 to 1 mm, more preferably 0.2 to 0.9 mm, and further preferably 0.3 to 0.9 mm. And most preferably 0.3 to 0.8 mm.
  • the laminating step of the solar cell module is performed at a relatively low temperature. Can do. Moreover, such a solar cell sealing material has sufficient light transmittance, and raises the photovoltaic power generation amount of a solar cell module.
  • the sheet-like solar cell encapsulant is a single-wafer format cut according to the size of the solar cell module, or a roll format that can be cut according to the size immediately before producing the solar cell module Good.
  • the sheet-like solar cell encapsulant which is a preferred embodiment of the present invention only needs to have at least one layer composed of the above-described ethylene-based resin composition.
  • the layer made of the above-described ethylene-based resin composition may be a single layer or two or more layers. From the viewpoint of cost reduction, reduction of interface reflection between layers, and effective use of light, a single sheet-like solar cell encapsulant sheet made of the aforementioned ethylene-based resin composition is preferable.
  • the sheet-like solar cell encapsulant may be composed only of the above-described ethylene-based resin composition, or a layer other than the layer composed of the above-mentioned ethylene-based resin composition (hereinafter also referred to as “other layers”). ).
  • the other layers include a hard coat layer for protecting the front surface or the back surface, an adhesive layer, an antireflection layer, a gas barrier layer, an antifouling layer, and the like.
  • examples of other layers include ultraviolet curable resin layers, thermosetting resin layers, polyolefin resin layers, carboxylic acid-modified polyolefin resin layers, fluorine-containing resin layers, cyclic olefin (co) polymer-containing layers, inorganic compounds Layers etc. are included.
  • a preferable layer configuration is appropriately selected in relation to the object of the present invention.
  • Other layers may be sandwiched between layers made of two or more ethylene resin compositions, may be provided in the outermost layer of the solar cell sealing material, or may be provided in other locations. Good.
  • other layers may be provided only on one side of the solar cell encapsulant, or other layers may be provided on both sides of the solar cell encapsulant. The number of other layers is arbitrary, and other layers need not be provided.
  • laminating the layer composed of the above-mentioned ethylene-based resin composition and other layers there is no limitation on the means for laminating the layer composed of the above-mentioned ethylene-based resin composition and other layers, but a known melt extruder such as a cast molding machine, an extrusion sheet molding machine, an inflation molding machine, an injection molding machine or the like is used. It is preferable to use a method of obtaining a laminate by coextrusion, or a method of obtaining a laminate by melting or heating and laminating the other layer on one of the previously formed layers. Alternatively, lamination may be performed by a dry laminating method using an adhesive or a heat laminating method.
  • adhesives examples include maleic anhydride-modified polyolefin resins (trade name “Admer” manufactured by Mitsui Chemicals, Inc., product name “Modic” manufactured by Mitsubishi Chemical Corporation), and low (non) crystalline soft materials such as unsaturated polyolefins.
  • Acrylic adhesives such as polymers, ethylene / acrylic acid ester / maleic anhydride terpolymers (trade name “Bondyne” manufactured by Sumika DF Chemical Co., Ltd.), or ethylene / vinyl acetate copolymers
  • An adhesive resin composition containing The adhesive preferably has a heat resistance of about 120 to 150 ° C., and a polyester-based or polyurethane-based adhesive may be suitable.
  • the adhesion layer may be improved by treating the surface of the adhesive layer with a silane coupling treatment, a titanium coupling treatment, a corona treatment, a plasma treatment or the like.
  • a crystalline solar cell module which is an example of a solar cell module, usually has a solar cell element, a solar cell sealing layer that sandwiches the solar cell element, and a protective sheet that covers both surfaces. That is, a typical configuration of a solar cell module is “protection sheet for solar cell module (surface protection member) / sealing layer / solar cell element / sealing layer / protection sheet for solar cell module (back surface protection member)”. is there.
  • the solar cell module in the present invention is not limited to the above configuration, and some layers can be omitted as appropriate and other layers can be added as appropriate without departing from the object of the present invention.
  • layers are, for example, an adhesive layer, a shock absorbing layer, a coating layer, an antireflection layer, a back surface rereflection layer, and a light diffusion layer. These layers can be provided at appropriate positions in consideration of the purpose and characteristics of providing each layer.
  • a solar cell module including a solar cell element that is a crystalline power generation element may generate PID. Since the solar cell sealing material of the present invention is effective in suppressing the generation of PID, it can be suitably applied to a solar cell module including a solar cell element that is a crystalline power generation element.
  • FIG. 1 shows an example of the configuration of a crystalline silicon solar cell module.
  • a solar cell module 20 shown in FIG. 1 includes a plurality of crystalline silicon-based solar cell elements 22 electrically connected by an interconnector 29, and a pair of surface protection members 24 and a back surface protection member 26 sandwiching the solar cell elements.
  • the sealing layer 28 is filled between the protective member and the plurality of solar cell elements 22.
  • the sealing layer 28 is in contact with the electrodes formed on the light receiving surface and the back surface of the solar cell element 22.
  • the electrode is a current collecting member formed on each of the light receiving surface and the back surface of the solar cell element 22 and includes a power collecting wire, a tabbed bus, a back electrode layer, and the like which will be described later.
  • the sealing layer 28 is obtained by heat-pressing a solar cell sealing material.
  • FIG. 2 shows an example of the configuration of the light receiving surface 22A and the back surface 22B of the solar cell element 22.
  • the light receiving surface 22A of the solar cell element 22 has a collection line 32 formed in a number of lines, and a tab that connects to the collection line 32 and connects to the interconnector 29.
  • a bus bar (bus bar) 34A is formed.
  • a conductive layer (back electrode) 36 is formed on the entire back surface 22B of the solar cell element 22, and a tab attached to the interconnector 29 is formed thereon.
  • a bus bar (bus bar) 34B is formed.
  • the line width of the collector line 32 is, for example, about 0.1 mm; the line width of the tabbed bus 34A is, for example, about 2 to 3 mm; and the line width of the tabbed bus 34B is, for example, about 5 to 7 mm. is there.
  • the thickness of the current collector 32, the tabbed bus 34A and the tabbed bus 34B is, for example, about 20 to 50 ⁇ m.
  • the current collector 32, the tabbed bus 34A, and the tabbed bus 34B preferably contain a highly conductive metal.
  • highly conductive metals include gold, silver, copper, and the like. From the viewpoint of conductivity and corrosion resistance, silver, a silver compound, an alloy containing silver, and the like are preferable.
  • the conductive layer 36 contains not only a highly conductive metal but also a highly light reflective component, for example, aluminum from the viewpoint of improving the photoelectric conversion efficiency of the solar cell element by reflecting light received by the light receiving surface. It is preferable.
  • the current collector 32, the tabbed bus 34 ⁇ / b> A, the tabbed bus 34 ⁇ / b> B, and the conductive layer 36 are made of a conductive material paint containing the highly conductive metal on the light receiving surface 22 ⁇ / b> A or the back surface 22 ⁇ / b> B of the solar cell element 22, for example, a screen. It is formed by applying to a coating thickness of 50 ⁇ m by printing, drying, and baking at, for example, 600 to 700 ° C. as necessary.
  • the surface protection member 24 Since the surface protection member 24 is disposed on the light receiving surface side, it needs to be transparent. Examples of the surface protection member 24 include a transparent glass plate and a transparent resin film. On the other hand, the back surface protection member 26 does not need to be transparent, and the material is not particularly limited. Examples of the back surface protection member 26 include a glass substrate and a plastic film, but a glass substrate is preferably used from the viewpoint of durability and transparency.
  • the solar cell module 20 can be manufactured by an arbitrary method.
  • the solar cell module 20 obtains a laminate in which the back surface protection member 26, the solar cell sealing material, the plurality of solar cell elements 22, the solar cell sealing material, and the surface protection member 24 are laminated in this order; A step of pressing and bonding the body with a laminator or the like, and simultaneously heating as necessary; after the step, the laminate may be further heat-treated as necessary to cure the sealing material. .
  • Thin film silicon (amorphous silicon) solar cell module) Furthermore, a thin amorphous silicon film of several ⁇ m formed by chemical vapor deposition (CVD) from silane gas or the like is formed on a glass or film substrate; further, an electrode is formed by sputtering silver or the like to form a thin film silicon system It is good also as a solar cell element.
  • a thin film silicon solar cell element, a solar cell sealing material, and a solar cell module protection sheet (back surface protection member) may be laminated in this order to form a thin film silicon solar cell module.
  • the thin-film silicon-based solar cell module includes (1) a surface side transparent protective member (glass substrate) / thin film type solar cell element / sealing layer / back surface protective member laminated in this order; (2) surface side transparent protective member / The sealing layer / thin film solar cell element / sealing layer / back surface protective member may be laminated in this order.
  • the front surface side transparent protective member, the back surface protective member, and the sealing layer are the same as those in the above-mentioned “crystalline silicon solar cell module”.
  • the thin film type solar cell element in the aspect of (1) includes, for example, transparent electrode layer / pin type silicon layer / back electrode layer in this order.
  • the transparent electrode layer include semiconductor oxides such as In 2 O 3 , SnO 2 , ZnO, Cd 2 SnO 4 , ITO (In 2 O 3 with Sn added).
  • the back electrode layer includes, for example, a silver thin film layer. Each layer is formed by a plasma CVD (chemical vapor deposition) method or a sputtering method.
  • a sealing layer is arrange
  • the thin film type solar cell element in the aspect of (2) includes, for example, a transparent electrode layer / pin type silicon layer / metal foil, or a metal thin film layer (for example, a silver thin film layer) disposed on a heat resistant polymer film.
  • the metal foil include stainless steel foil.
  • the heat resistant polymer film include a polyimide film.
  • the transparent electrode layer and the pin type silicon layer are formed by the CVD method or the sputtering method as described above. That is, the pin-type silicon layer is formed on a metal foil or a metal thin film layer disposed on a heat-resistant polymer film; and the transparent electrode layer is formed on a pin-type silicon layer.
  • positioned on a heat resistant polymer film can also be formed by CVD method or a sputtering method.
  • the sealing layer is disposed between the transparent electrode layer and the surface protection member; and between the metal foil or the heat-resistant polymer film and the back surface protection member.
  • the sealing layer obtained from a solar cell sealing material contacts electrodes, such as a current collection line of a solar cell element, a bus bar with a tab, and a conductive layer.
  • the silicon layer of the thin film type solar cell element in the aspect (2) is thinner than the crystalline silicon-based solar cell element, the thin film type solar cell element is subjected to pressurization at the time of manufacturing the solar cell module or external impact at the time of operating the module. Hard to break.
  • the flexibility of the solar cell encapsulant for the thin film silicon solar cell module may be inferior to the solar cell encapsulant for the crystalline silicon solar cell module.
  • the electrode (metal thin film) of the thin film solar cell element is corroded and deteriorated, the power generation efficiency may be significantly reduced.
  • the solar cell encapsulant of the present invention made of an ethylene-based resin composition may be less flexible than an ethylene / vinyl acetate copolymer (EVA), or necessarily requires a cross-linking agent as a generation source of decomposition gas. And not. Therefore, the solar cell sealing material of this invention is used more suitably as a solar cell sealing material for thin film solar cell modules.
  • the solar cell element is usually provided with a collecting electrode for taking out the generated electricity.
  • Examples of current collecting electrodes include bus bar electrodes, finger electrodes, and the like.
  • the collector electrode has a structure in which the collector electrode is disposed on both the front and back surfaces of the solar cell element. However, if the collector electrode is disposed on the light receiving surface, the collector electrode blocks light and power generation efficiency is reduced. Problems can arise.
  • a back contact type solar cell element that does not require a collector electrode on the light receiving surface has been studied.
  • p-doped regions and n-doped regions are alternately provided on the back surface side opposite to the light receiving surface of the solar cell device.
  • a p / n junction is formed on a substrate provided with a through hole (through hole), and the surface (light-receiving surface) side of the through hole inner wall and the through hole peripheral portion on the back surface side is formed.
  • a doped layer is formed, and the current on the light receiving surface is taken out on the back side.
  • the system voltage of a small-scale solar cell system for residential use is set to 50 to 500 V
  • the system voltage of a large-scale solar cell system called a mega solar is set to 600 to 1000 V.
  • the outer frame of the solar cell module is often an aluminum frame or the like, and the aluminum frame is often grounded from the viewpoint of safety.
  • the sealing layer between the power generation solar cell element and the glass substrate (protective member) or the aluminum frame is required to have electrical characteristics such as high electrical insulation and high resistance.
  • the sealing layer on the back surface of the solar cell element constituting the solar cell module needs to have adhesiveness with the sealing layer, electrode, or back surface protective layer on the back surface of the solar cell element.
  • the sealing layer, electrode, or back surface protective layer on the back surface of the solar cell element in order to maintain the smoothness of the back surface of the solar cell element, it is necessary to have thermoplasticity.
  • the sealing layer on the back surface of the solar cell element may not have transparency.
  • the solar cell sealing material of the present invention is more suitably used to form a sealing layer on the back surface of the solar cell element; in particular, the sealing layer on the back surface side of the crystalline solar cell module and moisture penetration is weak. It is suitably used as a sealing layer on the back side of the thin film solar cell module.
  • the sealing layer in the solar cell module has heat resistance.
  • the ethylene resin composition constituting the sealing layer may be altered or deteriorated by heating in the lamination process in the production of solar cell modules or heating by solar light during long-term use of solar cell modules. And it is desirable not to decompose. If the additives contained in the ethylene-based resin composition are eluted or decomposed products are generated, they act on the electromotive force surface (element surface) of the solar cell element, thereby deteriorating its function and performance. For this reason, the heat resistance of the sealing layer of the solar cell module is an indispensable characteristic. Furthermore, it is preferable that the sealing layer is excellent in moisture resistance. In this case, moisture permeation from the back side of the solar cell module can be prevented, and corrosion and deterioration of the solar cell element of the solar cell module can be prevented.
  • the surface protection member in the solar cell module is not particularly limited, but is located on the outermost layer of the solar cell module, so that it can be used for a long period of time in outdoor exposure of the solar cell module, including weather resistance, water repellency, contamination resistance, and mechanical strength. It is preferable to have performance for ensuring reliability. Moreover, in order to utilize sunlight effectively, it is preferable that it is a highly transparent sheet
  • Examples of the material for the surface protection member in the solar cell module include a resin film made of polyester resin, fluororesin, acrylic resin, cyclic olefin (co) polymer, ethylene-vinyl acetate copolymer, a glass substrate, and the like.
  • the resin film is preferably a polyester resin excellent in transparency, strength, cost, etc., in particular, a polyethylene terephthalate resin, a fluorine resin having good weather resistance, or the like.
  • fluororesins examples include tetrafluoroethylene-ethylene copolymer (ETFE), polyvinyl fluoride resin (PVF), polyvinylidene fluoride resin (PVDF), polytetrafluoroethylene resin (TFE), and tetrafluoroethylene.
  • ETFE tetrafluoroethylene-ethylene copolymer
  • PVDF polyvinylidene fluoride resin
  • TFE polytetrafluoroethylene resin
  • FEP hexafluoropropylene copolymer
  • CTFE polytrifluoroethylene chloride
  • 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.
  • a corona treatment and a plasma treatment on the surface protection member in order to improve the adhesion with a material constituting another layer such as a sealing material layer. 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.
  • the glass substrate has a total light transmittance of 80% or more at a wavelength of 350 to 1400 nm, preferably 90% or more.
  • a white plate glass substrate with little absorption in the infrared region is used, but blue plate glass may be used. Blue plate glass having a thickness of 3 mm or less does not substantially deteriorate the output characteristics of the solar cell module.
  • the glass substrate may be tempered glass that has been heat-treated to increase mechanical strength, but may also be float plate glass without heat treatment. Further, an antireflection coating for suppressing reflection may be provided on the light receiving surface side of the glass substrate.
  • back surface protection member in solar cell module Since the back surface protection member in a solar cell module is located in the outermost layer of a solar cell module, various characteristics, such as a weather resistance and mechanical strength, can be calculated
  • 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.
  • Preferred reinforcing plates can be, for example, steel plates, plastic plates, FRP (glass fiber reinforced plastic) plates, and the like.
  • the solar cell encapsulant of the present invention may be integrated with the back surface protective member.
  • the process during module assembly can be simplified. For example, a step of cutting the solar cell sealing material and the back surface protection member into a module size becomes unnecessary.
  • the process of laying up the solar cell sealing material and the back surface protecting member can be simplified or omitted.
  • the solar cell sealing material and the back surface protection member may be laminated.
  • the lamination method is not limited, but a method of obtaining a laminate by co-extrusion using a known melt extruder such as a cast molding machine, an extrusion sheet molding machine, an inflation molding machine, an injection molding machine, etc .; on one preformed layer
  • a method of obtaining a laminate by melting or heat laminating the other layer is preferable.
  • lamination may be performed by a dry laminating method using an appropriate adhesive or a heat laminating method.
  • adhesives include maleic anhydride-modified polyolefin resins (trade name “Admer” manufactured by Mitsui Chemicals, Inc., product name “Modic” manufactured by Mitsubishi Chemical Corporation), and low (non) crystalline soft materials such as unsaturated polyolefins.
  • Adhesives containing acrylic adhesives such as polymers, ethylene / acrylic acid ester / maleic anhydride terpolymers (such as “Bondaine” manufactured by Sumika DF Chemical Co., Ltd.), or ethylene / vinyl acetate copolymers A functional resin composition is included.
  • the adhesive preferably has a heat resistance of about 120 to 150 ° C., and specifically, a polyester-based or polyurethane-based adhesive is preferable. Further, at least one surface of the member to be bonded may be subjected to silane coupling treatment, titanium coupling treatment, corona treatment, plasma treatment, or the like to improve the adhesion.
  • the solar cell element in the solar cell module is not limited as long as it can generate power using the photovoltaic effect of the semiconductor.
  • Solar cell elements include, for example, silicon (single crystal, polycrystal, amorphous) solar cells, compound semiconductor (III-III, II-VI, etc.) solar cells, wet solar cells, organic It can be a semiconductor solar cell or the like. Among these, a polycrystalline silicon solar cell is preferable from the viewpoint of balance between power generation performance and cost.
  • a solar cell element using silicon As a solar cell element using silicon, a hybrid type (HIT type) solar cell element in which crystalline silicon and amorphous silicon are laminated, a multi-junction type (tandem) in which silicon layers having different absorption wavelength ranges are laminated Type) solar cell element, back contact type solar cell element in which p-doped regions and n-doped regions are alternately provided on the back side provided on the opposite side of the light receiving surface of the solar cell element, innumerable spherical silicon particles (diameter 1 mm) And a spherical silicon solar cell element that combines a concave mirror (also serving as an electrode) with a diameter of 2 to 3 mm that increases the light collecting ability.
  • HIT type hybrid type
  • tandem multi-junction type in which silicon layers having different absorption wavelength ranges are laminated
  • back contact type solar cell element in which p-doped regions and n-doped regions are alternately provided on the back side provided on the opposite side
  • the “insulated transparent electrode” which is an amorphous silicon type p-type window layer having a conventional pin junction structure is replaced with “an inversion layer induced by a field effect”.
  • a field effect solar cell element and the like are also included.
  • a GaAs solar cell element using single crystal GaAs CIS or CIGS system using a I-III-VI group compound called chalcopyrite system composed of Cu, In, Ga, Al, Se, S, etc. (chalcopyrite) System) solar cell element; CdTe-CdS solar cell element using a Cd compound thin film as the solar cell element; Cu 2 ZnSnS 4 (CZTS) solar cell element.
  • the solar cell sealing material of this invention can be used as a solar cell sealing material of a solar cell module including all these solar cell elements.
  • Both silicon solar cell elements and compound semiconductor solar cell elements have excellent characteristics as solar cell elements, but are known to be easily damaged by external stress and impact. Since the sealing layer obtained from the solar cell sealing material of the present invention is excellent in flexibility, it can absorb stress, impact, etc. on the solar cell element and effectively prevent damage to the solar cell element. . Therefore, it is preferable that the sealing layer formed from the solar cell sealing material of the present invention is directly joined to the solar cell element in the solar cell module. Moreover, since the solar cell element can be once taken out from the solar cell module relatively easily when the sealing layer has thermoplasticity, it is excellent in recyclability. Since the sealing layer formed from the solar cell sealing material of this invention has thermoplasticity, it is preferable also from a viewpoint of the recyclability of a solar cell module.
  • the structure and material of the electrode of a solar cell module are not specifically limited, In a specific example, it has a laminated structure of a transparent conductive film and a metal film.
  • the transparent conductive film is made of SnO 2 , ITO, ZnO or the like.
  • the metal film is made of a metal such as silver, gold, copper, tin, aluminum, cadmium, zinc, mercury, chromium, molybdenum, tungsten, nickel, and vanadium. These metal films may be used alone or as a composite alloy.
  • the transparent conductive film and the metal film are formed by a method such as CVD, sputtering, or vapor deposition.
  • An example of the manufacturing method of the solar cell module of the present invention includes (i) a front surface side transparent protective member, a solar cell encapsulant, a solar cell element (cell), a solar cell encapsulant, and a back side protective member. Are laminated in this order to form a laminate, and (ii) a step of pressurizing and heating the resulting laminate for integration.
  • step (i) it is preferable to dispose the surface on which the uneven shape (embossed shape) of the solar cell sealing material is formed facing the solar cell element.
  • step (ii) the laminate obtained in step (i) is integrated (sealed) by heating and pressing using a vacuum laminator or a hot press according to a conventional method.
  • sealing since the solar cell sealing material of the present invention has high cushioning properties, damage to the solar cell element can be prevented. Moreover, since the deaeration property is good, there is no air entrainment, and a high-quality product can be manufactured with a high yield.
  • the ethylene / ⁇ -olefin resin composition constituting the solar cell encapsulant is crosslinked and cured. This crosslinking may be performed simultaneously with step (ii) or after step (ii).
  • step (ii) When the cross-linking step is performed after step (ii), vacuum and heating is performed for 3 to 6 minutes in the step (ii) at a temperature of 125 to 160 ° C. and a vacuum pressure of 10 Torr or less; The above laminate is integrated for about one minute.
  • the crosslinking step performed after the step (ii) can be performed by a general method. For example, a tunnel-type continuous crosslinking furnace may be used, or a shelf-type batch-type crosslinking furnace may be used. .
  • the crosslinking conditions are usually 130 to 155 ° C. and about 20 to 60 minutes.
  • the crosslinking step is performed in the step (ii) except that the heating temperature in the step (ii) is 145 to 170 ° C. and the pressurizing time at atmospheric pressure is 6 to 30 minutes. It can be performed under the same conditions as those performed after ii).
  • the solar cell encapsulant of the present invention has excellent cross-linking properties by containing a specific organic peroxide, and it is not necessary to go through a two-step bonding process in the step (ii), and it is short at a high temperature. It can be completed in time, and the crosslinking step performed after step (ii) can be omitted. Therefore, the productivity of the solar cell module can be increased.
  • the solar cell module according to the present invention is manufactured at a temperature at which the crosslinking agent does not substantially decompose and the solar cell sealing material of the present invention melts.
  • the battery sealing material may be temporarily bonded and then heated to sufficiently bond and cross-link the sealing material. What is necessary is just to select the additive prescription which can satisfy various conditions, for example, what is necessary is just to select the kind and impregnation amount, such as the said crosslinking agent and the said crosslinking adjuvant.
  • the gel fraction of the solar cell encapsulant of the present invention laminated under the crosslinking conditions is in the range of 50 to 95%, preferably 50 to 90%, more preferably 60 to 90%, most preferably 65 to 90%. It is preferable that The gel fraction is calculated by, for example, collecting 1 g of a sealing material sheet sample from a solar cell module, performing Soxhlet extraction with boiling toluene for 10 hours, and filtering with a stainless mesh of 30 mesh, and the mesh at 110 ° C. Drying under reduced pressure for 8 hours is calculated from the amount of the filtered material remaining on the mesh. When the gel fraction is less than 50%, the heat resistance of the solar cell encapsulant is insufficient, a constant temperature and humidity test at 85 ° C.
  • the solar cell module 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 and the like, and has a high practical value.
  • the power generation equipment described above is suitable for long-term use, both outdoors and indoors, such as being installed on the roof of a house, used as a mobile power source for outdoor activities such as camping, and used as an auxiliary power source for automobile batteries. .
  • Measuring method [content ratio of ethylene unit, ⁇ -olefin unit, and non-conjugated polyene unit]
  • a solution obtained by heating and dissolving 0.35 g of a sample in 2.0 ml of hexachlorobutadiene was filtered through a glass filter (G2).
  • 0.5 ml of deuterated benzene was added to the filtrate and charged into an NMR tube having an inner diameter of 10 mm.
  • 13 C-NMR measurement was performed at 120 ° C. The number of integration was 8000 times or more.
  • the ethylene unit content, the ⁇ -olefin unit content, and the non-conjugated polyene unit content in the ethylene / ⁇ -olefin / non-conjugated polyene copolymer were quantified.
  • MFR2 Based on ASTM D1238, MFR2 of the ethylene / ⁇ -olefin / nonconjugated polyene copolymer was measured under the conditions of 190 ° C. and 2.16 kg load.
  • the measurement apparatus is a gel permeation chromatograph (trade name “Alliance GPC2000”, manufactured by Waters), the column uses Gel (trade name “GMHHR-H”) (two) manufactured by Tosoh Corporation, and the detector A differential refractometer (trade name “RI-8020”) manufactured by Tosoh Corporation was used, and Lab Connection Inc. was used as the FTIR apparatus. A device (trade name “LC-Transform Series300”) manufactured by the company was used.
  • the molecular weight was calculated in terms of polyisobutylene.
  • a detector and an FTIR apparatus were connected in parallel to the column outlet piping so that the flow rates were substantially equal.
  • the maximum peak intensity at 721 ⁇ 20 cm ⁇ 1 was the intensity from the base line connecting the minimum point of 782 ⁇ 20 cm ⁇ 1 and the minimum point of 690 ⁇ 20 cm ⁇ 1 .
  • the maximum peak intensity of 4320 ⁇ 20 cm ⁇ 1 was the intensity from the base line connecting the minimum point of 4480 ⁇ 20 cm ⁇ 1 and the minimum point of 3500 ⁇ 20 cm ⁇ 1 .
  • melt complex viscosity-frequency curve (unit of melt complex viscosity; Pa / s, unit of frequency) of ethylene / ⁇ -olefin / nonconjugated polyene copolymer at temperatures of 170 ° C. and 210 ° C. (T (° C.)) Rad / s).
  • T 210 ° C.
  • the melt complex viscosity-frequency curve is composed of ethylene / ⁇ -olefin / non-conjugated polyene at 190 ° C. for each melt complex viscosity-frequency curve at each temperature (T). Overlay the melt complex viscosity-frequency curve of the coalescence.
  • the logarithmic curve of melt complex viscosity-frequency at each temperature (T) was moved aT times in the frequency (X-axis direction) and moved 1 / aT times in the melt complex viscosity (Y-axis direction).
  • the correlation coefficient when the shift factor (aT) at temperatures (T) of 170 ° C., 190 ° C. and 210 ° C. and the first-order approximation (I) obtained from the temperature (T) are obtained by the method of least squares. was 0.99 or more.
  • the melt complex viscosity-frequency curve is prepared by measuring using the following viscoelasticity measuring apparatus.
  • a sample piece a 2 mm thick sheet obtained by pressing an ethylene / ⁇ -olefin / non-conjugated polyene copolymer at 190 ° C. is punched into a disk shape having a diameter of 25 mm ⁇ 2 mm.
  • the sample piece may contain an appropriate amount of antioxidant (for example, about 1000 ppm) in advance.
  • the mobile phase was a solution of o-dichlorobenzene (manufactured by Wako Pure Chemical Industries, Ltd.) and 0.025 wt% BHT (manufactured by Takeda Pharmaceutical) as an antioxidant.
  • the mobile phase was moved at a rate of 1.0 ml / min, the sample concentration was 15 mg / 10 ml, the sample injection amount was 500 ⁇ l, and a differential refractometer was used as the detector.
  • a standard polystyrene having a molecular weight of Mw ⁇ 1000 and Mw ⁇ 4 ⁇ 10 6 polystyrene manufactured by Tosoh Corporation was used.
  • polystyrene manufactured by Pressure Chemical Co. was used as a standard polystyrene having a molecular weight of 1000 ⁇ Mw ⁇ 4 ⁇ 10 6 .
  • Glass adhesive strength A transparent glass plate, which is a surface-side transparent protective member for solar cells, and a sheet sample having a thickness of 500 ⁇ m were laminated and set in a vacuum laminator (NPC, LM-110X160S). The laminate was placed on a hot plate adjusted to 150 ° C. and heated for 3 minutes under reduced pressure for 9 minutes to prepare a sample for bonding strength, which is a laminate of transparent glass plates / sheet samples.
  • the sheet sample layer of the sample for adhesion strength was cut into a width of 15 mm, and the peel strength from the glass (glass adhesion strength) was measured at 180 ° peel (30 mm between spans, tensile speed 30 mm / min, measurement temperature 23 ° C.). For the peel measurement, an Instron tensile tester (trade name “Instron1123”) was used. The average value of three measurements was adopted.
  • Total light transmittance A white sheet glass having no absorption region in the wavelength range of 350 to 800 nm was used, and a laminate was obtained under the same conditions as in the preparation of the adhesive strength sample with the structure of white sheet glass / sheet sample / white sheet glass. Using a spectrophotometer (trade name “U-3010”) manufactured by Hitachi, Ltd. equipped with an integrating sphere of ⁇ 150 mm, the spectral total light transmittance of the sheet sample in the laminate was measured in the wavelength range of 350 to 800 nm. . Then, the total light transmittance (Tvis) of visible light was calculated by multiplying the measurement result by the standard light D65 and the standard luminous efficiency V ( ⁇ ).
  • Electrode corrosion A sheet sample was sandwiched between a pair of glass plates (thin film electrodes) in which silver was sputtered at the center. This was processed under the same conditions as those for producing the above-mentioned sample for adhesive strength to obtain a laminate. Based on JIS C8917, the obtained laminate was subjected to an accelerated test of the laminate under the conditions of a product name “XL75” manufactured by Suga Test Instruments Co., Ltd. under the conditions of 85 ° C. and 85% humidity. Went for hours. The state of the thin film electrode of the obtained accelerated test sample was visually observed to evaluate electrode corrosivity.
  • the sheet sample was set in a vacuum laminator, placed on a hot plate adjusted to 150 ° C., and heated for 3 minutes under reduced pressure for 9 minutes to obtain a crosslinked sheet sample.
  • the obtained crosslinked sheet sample was cut into a width of 1 cm and a length of 5 cm.
  • a marked line was drawn with a length of 3 cm, and a weight three times as large as the cut sample was hung and left in an oven at 100 ° C. for 1 hour to conduct a heat resistance test.
  • the elongation between the marked lines of the sample after the test was measured. Note that samples dropped during the heat resistance test were evaluated as “falling”.
  • the heat resistance test is used as an index of cross-linking properties. If the cross-linking is sufficient, the elongation during the heat test is small. If the cross-linking is insufficient, the elongation during the heat test is large. May fall.
  • the obtained sheet was cut into a size of 10 cm ⁇ 10 cm.
  • the cut sample was heated and pressurized with a laminating apparatus (manufactured by NPC, LM-110X160S) (150 ° C., vacuum 3 minutes, pressure 15 minutes) to prepare a crosslinked sheet for measurement.
  • the volume specific resistance ( ⁇ ⁇ cm) of the prepared crosslinked sheet was measured at an applied voltage of 500 V in accordance with JIS K6911.
  • the temperature was set to 100 ⁇ 2 ° C. using a high temperature measurement chamber “12708” (manufactured by Advanced), and a micro ammeter “R8340A” (manufactured by Advanced) was used.
  • Table 1 shows the physical properties of the obtained ethylene / ⁇ -olefin / non-conjugated polyene copolymer.
  • Vanadium oxychloride was supplied so that the vanadium concentration in the polymerization vessel was 0.3 mmol / L. Further, ethylaluminum sesquichloride was supplied so that the aluminum concentration in the polymerization vessel was 3 mmol / L.
  • the polymerization temperature was adjusted to 30 ° C.
  • a methanol, which is a deactivator, is mixed with a normal hexane mixed solution of ethylene / ⁇ -olefin / non-conjugated polyene copolymer continuously discharged from the lower part of the polymerization vessel at a rate of about 0.2 mL / min. The polymerization was stopped by deactivating the catalyst.
  • the normal hexane mixed solution of ethylene / ⁇ -olefin / non-conjugated polyene copolymer is dried with a vacuum dryer at 130 ° C. to obtain 210 g / hr of ethylene / ⁇ -olefin / non-conjugated polyene copolymer. Obtained.
  • Table 1 shows the physical properties of the obtained ethylene / ⁇ -olefin / non-conjugated polyene copolymer.
  • An embossed sheet (solar cell sealing material sheet) having a thickness of 500 ⁇ m is formed by using an embossing roll as the first cooling roll at a roll temperature of 30 ° C. and a winding speed of 1.0 m / min under a die temperature of 100 ° C. Got.
  • the porosity of the obtained sheet was 28%. Table 2 shows various evaluation results of the obtained sheet.
  • Examples 2 to 6 Except having set it as the composition shown in Table 2, it carried out similarly to the above-mentioned Example 1, and obtained the embossed sheet (solar cell sealing material sheet). All the void ratios of the obtained sheets were 28%. Table 2 shows various evaluation results of the obtained sheet.
  • the ethylene / ⁇ -olefin / non-conjugated polyene copolymer obtained in Synthesis Example 10 was used after freeze pulverization.
  • Example 2 An embossed sheet (solar cell encapsulant sheet) was obtained in the same manner as in Example 1 except that the composition shown in Table 2 was used. However, the torque of the extruder became too high, and the torque was over and a sheet could not be obtained.
  • Example 3 An embossed sheet (solar cell encapsulant sheet) was obtained in the same manner as in Example 1 except that the composition shown in Table 2 was used. However, the adhesion to the embossing roll and the rubber roll was too strong, and the sheet could not be obtained without being peeled off.
  • Example 7 (A) 100 parts by weight of an ethylene / propylene / diene copolymer (Mitsui Chemicals, trade name EPT3045, diene: 5-ethylidene-2-norbornene, no melting point) and (B) paraffinic oil (Idemitsu Kosan) A product name PW100, a density of 872 kg / cm 3 , a kinematic viscosity of 100 mm 2 / s @ 40 ° C., 70 parts by weight of hue + 30 (Saybolt), and a single screw extruder (screw diameter 20 mm ⁇ ) manufactured by Thermo Plastic Co., Ltd.
  • an ethylene / propylene / diene copolymer Mitsubishi Chemicals, trade name EPT3045, diene: 5-ethylidene-2-norbornene, no melting point
  • paraffinic oil Idemitsu Kosan
  • the embossed sheet (solar cell sealing material sheet) having a thickness of 500 ⁇ m was obtained.
  • the roll temperature is 30 ° C.
  • the winding speed is 1.0 m / min
  • the first cooling roll Was used as an embossing roll.
  • the porosity of the obtained sheet was 28%.
  • Various evaluation results of the obtained sheet are shown in Table 3.
  • Example 8 (A) Similar to Example 7 except that an ethylene / propylene / diene copolymer (Synthesis Example 13) was used instead of the ethylene / propylene / diene copolymer (trade name EPT3045, manufactured by Mitsui Chemicals, Inc.). Thus, a resin composition was obtained. Table 3 shows various evaluation results of the obtained resin composition.
  • the resin compositions obtained in Examples 7 and 8 and Comparative Examples 7 and 8 were evaluated for the melt flow rate (MFR), roll processability, crosslinking characteristics, and light transmittance of the cured product by the following methods.
  • melt flow rate A melt flow rate (MFR) at 190 ° C. under a load of 2.16 kg was measured by a method based on ASTM D1238 of the obtained oil-extended resin composition.
  • Maximum torque value S′max and minimum torque value S′min Maximum torque value S′max and minimum torque value S′min were calculated from the bridge curve.
  • Crosslinking start time Tc10 A torque value corresponding to the sum of the torque value corresponding to 10% of the difference between the aforementioned maximum torque value S'max and the minimum torque value S'min and the minimum torque value S'min is reached. The time until was Tc10 (min).
  • Optimal cross-linking time Tc90 the torque value corresponding to the sum of the torque value corresponding to 90% of the difference between the aforementioned maximum torque value S′max and the minimum torque value S′min and the minimum torque value S′min is reached. The time until was Tc90 (min).
  • the total light transmittance of the obtained sample was measured with a Hitachi spectrophotometer U-3010 with 150 mm ⁇ integrating sphere. Then, the total light transmittance (Tvis) of visible light was calculated by multiplying the measurement result by the standard light D65 and the standard luminous efficiency V ( ⁇ ).
  • volume resistivity The sheet obtained under the same conditions as in 4) above was cut into a size of 10 cm ⁇ 10 cm.
  • the cut sample was heated and pressurized with a laminating apparatus (manufactured by NPC, LM-110X160S) (150 ° C., vacuum 3 minutes, pressure 15 minutes) to prepare a crosslinked sheet for measurement.
  • the volume specific resistance ( ⁇ ⁇ cm) of the prepared crosslinked sheet was measured at an applied voltage of 500 V using a microammeter “R8340A” (manufactured by Advanced) according to JIS K6911.
  • the resin composition of Comparative Example 7 has good cross-linking characteristics due to the small amount of paraffinic oil added; however, since the viscosity is too high, the sheet appearance deteriorates and is close to melt fracture It can be seen that the sheet thickness is non-uniform. Since the resin composition of Comparative Example 8 contains a naphthenic oil containing a large amount of naphthene components and aroma components, it can be seen that the crosslinking properties are low and the light transmittance of the cured product is also low.
  • Example 9 Using the sealing material described in Example 6, 18 modules were connected in series using a single crystal cell.
  • the module glass was a heat-treated glass with an emboss having a thickness of 3.2 mm made of white plate float glass manufactured by Asahi Glass Fabrictech cut to 24 ⁇ 21 cm.
  • As the crystal cell single crystal cell manufactured by Shinsung
  • a cell cut at 5 ⁇ 3 cm with the bus bar silver electrode on the light receiving surface side as the center was used.
  • Eighteen cells were connected in series using a copper ribbon electrode whose surface was coated with eutectic solder on a copper foil.
  • As the back sheet a PET back sheet including a PET sheet having a silica film deposited thereon was used.
  • a portion of the backsheet was cut with a cutter-knife by about 2 cm, and used as a part for taking out a terminal from the cell.
  • the positive and negative terminals of 18 cells connected in series were taken out.
  • Lamination was performed using a vacuum laminator (manufactured by NPC: LM-110 ⁇ 160-S) at a heating plate temperature of 150 ° C., a vacuum time of 3 minutes, and a pressurization time of 15 minutes. Then, the sealing material and the back sheet which protruded from glass were cut, the end surface sealing material was provided to the glass edge, and the aluminum frame was attached. Thereafter, RTV silicone was applied to the portion where the back sheet was taken out and cured.
  • This module was set in a constant temperature and humidity chamber at 85 ° C. and 85% rh, and after the temperature was raised, ⁇ 600 V was applied and kept.
  • the high-voltage power supply was HARb-3R10-LF (manufactured by Matsusada Precision); the thermostatic chamber was FS-214C2 (manufactured by ETAC).
  • the module was evaluated for IV characteristics using a xenon light source having an AM (air mass) 1.5 class A light intensity distribution.
  • AM air mass
  • Nisshinbo Mechatronics PVS-116i-S was used for the IV evaluation. Further, when the maximum output power Pmax of the IV characteristic after the test was reduced by 5% or more compared to the initial value, it was determined as NG. As a result of the measurement, in all cases, the amount of change in Pmax after the high-pressure test was a decrease of 0.5 or less, which was a good result.
  • Example 10 The test was conducted in the same manner as in Example 10 except that the solar cell encapsulant described in Example 5 was used. The decrease in Pmax was 0.5% or less in all cases, which was a good result.
  • Example 11 The test was conducted in the same manner as in Example 10 except that the solar cell encapsulant described in Example 1 was used. The decrease in Pmax after applying the voltage for 24 hours was 0.5% or less.
  • Example 10 Using this sheet, a module was produced in the same manner as in Example 10. At this time, the hot platen temperature of the laminator was set to 125 ° C. The module was subjected to a high voltage application test in the same manner as in Example 10. The amount of decrease in Pmax after applying the voltage for 24 hours was 6%, and characteristic deterioration occurred.
  • the solar cell encapsulant of the present invention is excellent in various properties such as transparency, flexibility, adhesiveness, heat resistance and extrusion moldability. For this reason, if the solar cell sealing material of this invention is used, while being good in external appearance, the solar cell module excellent in economical efficiency, such as a performance and cost, can be provided.

Abstract

L'invention concerne un encapsulant de cellule solaire qui présente d'excellentes caractéristiques en termes de transparence, flexibilité, adhérence, résistance à la chaleur, apparence, propriétés de réticulation, propriétés électriques et aptitude au moulage par extrusion. Ledit encapsulant de cellule solaire contient un copolymère éthylène/α-oléfine/polyène non conjugué qui satisfait les conditions a1 à a3. Condition a1 : la proportion de motifs structuraux dérivés de l'éthylène est de 80 à 90 % en moles, la proportion de motifs structuraux dérivés d'α-oléfines avec 3 à 20 atomes de carbone est de 9,99 à 19,99 % en moles, et la proportion de motifs structuraux dérivés de polyènes non conjugués est de 0,01 à 5,0 % en moles. Condition a2 : l'indice de fluidité de l'encapsulant, mesuré à 190 °C sous une charge de 2,16 kg selon la norme ASTM D1238, est de 10 à 50 g/10 minutes. Condition a3 : la dureté Shore A, mesurée selon la norme ASTM D2240, est de 60 à 85.
PCT/JP2011/006547 2010-11-24 2011-11-24 Encapsulant de cellule solaire et module de cellules solaires utilisant ledit encapsulant WO2012070245A1 (fr)

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WO2013018839A1 (fr) * 2011-08-03 2013-02-07 電気化学工業株式会社 Matériau d'étanchéité
JP2013139558A (ja) * 2011-12-06 2013-07-18 Japan Polyethylene Corp 太陽電池封止材用樹脂組成物、及びそれを用いた太陽電池封止材、太陽電池モジュール
WO2014017282A1 (fr) * 2012-07-25 2014-01-30 株式会社ブリヂストン Film d'étanchéité pour cellules solaires, module de cellules solaires et procédé permettant de sélectionner un film d'étanchéité pour cellules solaires.
JP2014027035A (ja) * 2012-07-25 2014-02-06 Bridgestone Corp 太陽電池モジュール
JP2014027034A (ja) * 2012-07-25 2014-02-06 Bridgestone Corp 太陽電池用封止膜、及びその選定方法
JP2014062239A (ja) * 2012-08-28 2014-04-10 Japan Polyethylene Corp 太陽電池封止材用樹脂組成物、並びにそれを用いた太陽電池封止材及び太陽電池モジュール
WO2014133003A1 (fr) 2013-02-27 2014-09-04 日本ゼオン株式会社 Module de photopile et son procédé de fabrication
JP2014208774A (ja) * 2013-03-29 2014-11-06 日本ポリエチレン株式会社 エチレン系共重合体、並びにそれを用いた太陽電池封止材及び太陽電池モジュール
JP2015149442A (ja) * 2014-02-07 2015-08-20 大日本印刷株式会社 太陽電池モジュール用の封止材シート
JP2015199930A (ja) * 2014-03-31 2015-11-12 日本ポリエチレン株式会社 太陽電池封止材用樹脂組成物の製造方法、それを用いた太陽電池封止材及び太陽電池モジュール
JP2017019890A (ja) * 2015-07-07 2017-01-26 三井化学株式会社 エチレン・α−オレフィン・非共役ポリエン共重合体
WO2017073386A1 (fr) * 2015-10-30 2017-05-04 三井化学東セロ株式会社 Composition de résine de matériau d'étanchéité de cellule solaire, matériau d'étanchéité de cellule solaire et module de cellule solaire
JP2018131491A (ja) * 2017-02-14 2018-08-23 アイカ工業株式会社 封止樹脂組成物
WO2019003884A1 (fr) * 2017-06-28 2019-01-03 Nok株式会社 Composition de caoutchouc, et matériau de scellement pour séparateur de pile à combustible
WO2021053180A1 (fr) * 2019-09-19 2021-03-25 Sabic Global Technologies B.V. Élément photovoltaïque
CN115368831A (zh) * 2021-05-18 2022-11-22 杭州福斯特应用材料股份有限公司 封装胶膜及其制备方法
WO2023075501A1 (fr) * 2021-11-01 2023-05-04 주식회사 엘지화학 Copolymère éthylène/alpha-oléfine et composition pour film d'étanchéité le comprenant

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JP2007103738A (ja) * 2005-10-05 2007-04-19 Mitsui Chemicals Inc 太陽電池封止材、太陽電池封止用シート、およびそれらを用いた太陽電池モジュール。
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WO2013018839A1 (fr) * 2011-08-03 2013-02-07 電気化学工業株式会社 Matériau d'étanchéité
JP2013139558A (ja) * 2011-12-06 2013-07-18 Japan Polyethylene Corp 太陽電池封止材用樹脂組成物、及びそれを用いた太陽電池封止材、太陽電池モジュール
CN104662674B (zh) * 2012-07-25 2016-11-23 株式会社普利司通 太阳能电池用密封膜、太阳能电池组件、和太阳能电池用密封膜的选择方法
WO2014017282A1 (fr) * 2012-07-25 2014-01-30 株式会社ブリヂストン Film d'étanchéité pour cellules solaires, module de cellules solaires et procédé permettant de sélectionner un film d'étanchéité pour cellules solaires.
JP2014027035A (ja) * 2012-07-25 2014-02-06 Bridgestone Corp 太陽電池モジュール
JP2014027034A (ja) * 2012-07-25 2014-02-06 Bridgestone Corp 太陽電池用封止膜、及びその選定方法
CN104662674A (zh) * 2012-07-25 2015-05-27 株式会社普利司通 太阳能电池用密封膜、太阳能电池组件、和太阳能电池用密封膜的选择方法
JP2014062239A (ja) * 2012-08-28 2014-04-10 Japan Polyethylene Corp 太陽電池封止材用樹脂組成物、並びにそれを用いた太陽電池封止材及び太陽電池モジュール
WO2014133003A1 (fr) 2013-02-27 2014-09-04 日本ゼオン株式会社 Module de photopile et son procédé de fabrication
JP2014208774A (ja) * 2013-03-29 2014-11-06 日本ポリエチレン株式会社 エチレン系共重合体、並びにそれを用いた太陽電池封止材及び太陽電池モジュール
JP2015149442A (ja) * 2014-02-07 2015-08-20 大日本印刷株式会社 太陽電池モジュール用の封止材シート
JP2015199930A (ja) * 2014-03-31 2015-11-12 日本ポリエチレン株式会社 太陽電池封止材用樹脂組成物の製造方法、それを用いた太陽電池封止材及び太陽電池モジュール
JP2017019890A (ja) * 2015-07-07 2017-01-26 三井化学株式会社 エチレン・α−オレフィン・非共役ポリエン共重合体
WO2017073386A1 (fr) * 2015-10-30 2017-05-04 三井化学東セロ株式会社 Composition de résine de matériau d'étanchéité de cellule solaire, matériau d'étanchéité de cellule solaire et module de cellule solaire
JPWO2017073386A1 (ja) * 2015-10-30 2018-03-01 三井化学東セロ株式会社 太陽電池封止材用樹脂組成物、太陽電池封止材および太陽電池モジュール
JP2018131491A (ja) * 2017-02-14 2018-08-23 アイカ工業株式会社 封止樹脂組成物
WO2019003884A1 (fr) * 2017-06-28 2019-01-03 Nok株式会社 Composition de caoutchouc, et matériau de scellement pour séparateur de pile à combustible
JPWO2019003884A1 (ja) * 2017-06-28 2019-06-27 Nok株式会社 燃料電池セパレータ用シール材
WO2021053180A1 (fr) * 2019-09-19 2021-03-25 Sabic Global Technologies B.V. Élément photovoltaïque
CN115368831A (zh) * 2021-05-18 2022-11-22 杭州福斯特应用材料股份有限公司 封装胶膜及其制备方法
CN115368831B (zh) * 2021-05-18 2024-02-20 杭州福斯特应用材料股份有限公司 封装胶膜及其制备方法
WO2023075501A1 (fr) * 2021-11-01 2023-05-04 주식회사 엘지화학 Copolymère éthylène/alpha-oléfine et composition pour film d'étanchéité le comprenant

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