WO2016104175A1 - Sealing film for solar cells and solar cell using same - Google Patents

Sealing film for solar cells and solar cell using same Download PDF

Info

Publication number
WO2016104175A1
WO2016104175A1 PCT/JP2015/084753 JP2015084753W WO2016104175A1 WO 2016104175 A1 WO2016104175 A1 WO 2016104175A1 JP 2015084753 W JP2015084753 W JP 2015084753W WO 2016104175 A1 WO2016104175 A1 WO 2016104175A1
Authority
WO
WIPO (PCT)
Prior art keywords
solar cell
sealing film
mass
meth
acrylate compound
Prior art date
Application number
PCT/JP2015/084753
Other languages
French (fr)
Japanese (ja)
Inventor
勝也 石渡
佳彦 井上
服部　憲治
Original Assignee
株式会社ブリヂストン
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社ブリヂストン filed Critical 株式会社ブリヂストン
Publication of WO2016104175A1 publication Critical patent/WO2016104175A1/en

Links

Images

Classifications

    • 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
    • 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 sealing film and a solar cell using the same.
  • the light receiving surface side transparent protective member 11 made of a glass substrate or the like, the light receiving surface side sealing film 13A, the power generation element 14 such as a silicon crystal cell, the back surface side sealing A structure in which the stop film 13B and the back surface side protection member (back cover) 12 are laminated in this order and bonded and integrated is known.
  • connection tabs 15 In solar cells, a plurality of power generating elements 14 are connected by connection tabs 15 in order to obtain a high electrical output. Therefore, in order to ensure the insulation of the power generation element 14, the power generation element is sealed using the insulating sealing films 13A and 13B.
  • olefin copolymers such as ethylene-vinyl acetate copolymer (EVA) and ethylene-ethyl acrylate copolymer (EEA), and films made of polyvinyl butyral have been conventionally used. It is used.
  • EVA films are preferably used because they are inexpensive and have high transparency.
  • the EVA film for sealing films has improved the crosslinking density using crosslinking agents, such as an organic peroxide, other than EVA, in order to improve film
  • a large-scale photovoltaic power generation facility called a mega solar having an output of 1 MW or more
  • a high system voltage is required for reasons such as efficiency improvement of the transmission system.
  • the system voltage is 600 V or more, particularly 1000 V or more. Mega solar is also being built.
  • the PID phenomenon is a phenomenon in which output polarization is significantly reduced by polarization of electric charge in the internal circuit of the solar cell module and hindering movement of electrons inside the cell. This is because, in a photovoltaic power generation facility where the system voltage is increased, a large potential difference occurs between the grounded frame and the internal circuit of the solar cell module, and external factors such as humidity and temperature are caused by this. It is said that this is caused by a leakage current between the internal circuit of the module and the frame. Since the PID phenomenon occurs due to the interaction of each member of the solar cell module, the conditions for suppressing the occurrence have not yet been clarified.
  • An object of the present invention is to provide a solar cell sealing film that can suppress the occurrence of the PID phenomenon.
  • a sealing film for a solar cell including a sealing resin, crystalline porous aluminosilicate particles, and a bifunctional or higher functional (meth) acrylate compound.
  • Preferred embodiments of the present invention are as follows.
  • the (meth) acrylate compound has a — (C n H 2n O) — chain (where n is an integer of 2 to 5).
  • the (meth) acrylate compound has the following formula (I) (However, each R is independently a hydrogen atom or a methyl group, and m is an integer of 2 to 20.) It is a di (meth) acrylate compound represented by these.
  • the content of the crystalline porous aluminosilicate particles is 0.05 to 1 part by mass with respect to 100 parts by mass of the sealing resin, and the content of the (meth) acrylate compound is The amount is 0.05 to 1 part by mass with respect to 100 parts by mass of the sealing resin.
  • the solar cell sealing film that can effectively suppress the occurrence of the PID phenomenon and is excellent in transparency can be obtained.
  • the content of the crystalline porous aluminosilicate particles is 0.1 to 0.3 parts by mass with respect to 100 parts by mass of the sealing resin, and the content of the (meth) acrylate compound is The amount is 0.2 to 0.4 parts by mass with respect to 100 parts by mass of the sealing resin.
  • the sealing film for solar cells which is excellent in transparency and the generation
  • the silica / alumina ratio is 1-5. It is further superior in suppressing the occurrence of PID phenomenon.
  • the mass ratio of the crystalline porous aluminosilicate particles to the (meth) acrylate compound is 0.05 to 20.
  • the crystalline porous aluminosilicate contains a cation, and at least a part of the cation is selected from the group consisting of alkali metal ions excluding sodium ions, alkaline earth metal ions, and magnesium ions. At least one.
  • At least some of the cations are potassium ions.
  • Sodium ions are further included as cations.
  • the ratio of potassium ions to the total amount of potassium ions and sodium ions is 30 to 60 mol%.
  • the above object is also achieved by a solar cell manufactured by sealing a power generation element using the solar cell sealing film of the present invention.
  • the solar cell produced using the solar cell sealing film of the present invention is less prone to the PID phenomenon, and maintains a sufficient power generation capacity for a long time even when used in a large-scale solar power generation facility. Is possible.
  • the solar cell sealing film of the present invention includes a sealing resin, crystalline porous aluminosilicate particles, and a bifunctional or higher functional (meth) acrylate compound.
  • any crystalline porous aluminosilicate particles may be used.
  • a crystalline porous aluminosilicate is represented by the following formula (II). M 2 / n O ⁇ Al 2 O 3 ⁇ ySiO 2 ⁇ zH 2 O (II)
  • M represents a cation
  • n represents a valence of the cation M
  • y corresponds to a silica / alumina ratio, and is usually 1 to 100, preferably 1 to 10, particularly preferably 1 to 5.
  • . z is the number of water molecules contained in the pores, and is usually a number of 0 or more, preferably 0-20.
  • the cation M is preferably an alkali metal, an alkaline earth metal, or a magnesium ion, and examples thereof include calcium ion, barium ion, potassium ion, and sodium ion, and may be a combination of two or more of these.
  • At least a part of the cations is at least one selected from the group consisting of alkali metal ions excluding sodium ions, alkaline earth metal ions, and magnesium ions.
  • the cation is a potassium ion. Further, it is particularly preferable that the cation contains sodium ion in addition to at least a part of the cation described above. In the present invention, it is further preferable that both sodium ions and potassium ions are contained as cations. In this case, the potassium ion content is 30 to 60 mol% with respect to the total amount of sodium ions and potassium ions. And more preferably 30 to 45 mol%. If it is lower than this range, the effect of preventing the occurrence of the PID phenomenon may be reduced, and if it is higher than this range, foaming may occur on the back sheet side.
  • the crystal structure of the crystalline porous aluminosilicate may be any crystal structure such as L-type, X-type, A-type, and Y-type.
  • One type of crystalline porous aluminosilicate may be used alone, or two or more types may be used in combination.
  • the crystalline porous aluminosilicate particles are usually 0.05 to 5 parts by mass, preferably 0.05 to 1 part by mass, more preferably 0.1 to 0.5 parts by mass with respect to 100 parts by mass of the sealing resin. It is blended in an amount of part by mass, more preferably 0.1 to 0.3 part by mass. If the amount is less than this range, the PID suppressing effect may not be obtained. If the amount is more than this range, the transparency of the solar cell sealing film may decrease.
  • the average particle diameter of the crystalline porous aluminosilicate particles is, for example, 1 to 50 ⁇ m.
  • the average particle size of the crystalline porous aluminosilicate particles refers to the 50% particle size in the particle size distribution (volume average) determined by the laser diffraction scattering method.
  • the crystalline aluminosilicate particles those commercially available as zeolite can be used.
  • the solar cell sealing film of the present invention contains a bifunctional or higher functional (meth) acrylate compound (a compound having two or more (meth) acryloyloxy groups).
  • a bifunctional to hexafunctional one is preferred, and a bifunctional to tetrafunctional one is more preferred. It is preferable that no functional group other than the (meth) acryloyloxy group is present.
  • a preferred bifunctional or higher functional (meth) acrylate compound is a bifunctional or higher functional (meth) acrylate compound having a — (C n H 2n O) — chain (n is an integer of 2 to 5, preferably 2 or 3). .
  • the — (C n H 2n O) — chain is preferably a polyethylene glycol chain or a polypropylene glycol chain.
  • the number of repeating units of the — (C n H 2n O) — chain is preferably 2 to 20.
  • a more preferable (meth) acrylate compound is a di (meth) acrylate compound represented by the following formula (I).
  • each R is independently a hydrogen atom or a methyl group, preferably a methyl group, and m is an integer of 2 to 20, preferably an integer of 5 to 14, more preferably an integer of 7 to 12.
  • bifunctional or higher functional (meth) acrylate compound examples include pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, trimethylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri ( And (meth) acrylate.
  • the content of the (meth) acrylate compound is usually 0.05 to 1 part by mass, preferably 0.2 to 0.4 part by mass with respect to 100 parts by mass of the sealing resin. If the amount is less than this range, the PID phenomenon may not be sufficiently suppressed. If the amount is more than this range, the workability in producing a solar cell sealing film may be reduced.
  • the mass ratio of crystalline aluminosilicate particles to (meth) acrylate compound is preferably 0.05 to 20, more preferably 0.25 to 4. 1 to 2.5 is more preferable. If it is this range, the PID reduction suppression effect can be acquired effectively.
  • the sealing resin may be any resin as long as it can seal the power generating element.
  • a preferred sealing resin is an olefin (co) polymer.
  • the olefin (co) polymer means an ethylene / ⁇ -olefin copolymer (for example, an ethylene / ⁇ -olefin copolymer (m-LLDPE) polymerized using a metallocene catalyst), polyethylene (for example, low density) Polymers or copolymers of olefins such as polyethylene (LDPE), linear low density polyethylene (LLDPE), polypropylene and polybutene, and copolymers of olefin and polar monomer such as ethylene-polar monomer copolymer It has the adhesiveness, transparency, etc.
  • the olefin (co) polymer one of these may be used, or two or more may be mixed and used.
  • an ethylene / ⁇ -olefin copolymer (m-LLDPE) polymerized using a metallocene catalyst low density polyethylene (LDPE), linear low density polyethylene (LLDPE) is used.
  • LDPE low density polyethylene
  • LLDPE linear low density polyethylene
  • an olefin (co) polymer can be formed using a metallocene catalyst because it is excellent in processability, can form a crosslinked structure with a crosslinking agent, and can form a solar cell sealing film with high adhesion.
  • a polymerized ethylene / ⁇ -olefin copolymer (m-LLDPE) and / or an ethylene-polar monomer copolymer is preferred.
  • m-LLDPE is composed mainly of ethylene-derived constitutional units and further an ⁇ -olefin having 3 to 12 carbon atoms, such as , One or more kinds derived from propylene, 1-butene, 1-hexene, 1-octene, 4-methylpentene-1, 4-methyl-hexene-1, 4,4-dimethyl-pentene-1, etc.
  • the ethylene / ⁇ -olefin copolymer examples include an ethylene / 1-butene copolymer, an ethylene / 1-octene copolymer, an ethylene-4-methyl-pentene-1 copolymer, an ethylene / butene / hexene copolymer. Center polymers, ethylene / propylene / octene terpolymers, ethylene / butene / octene terpolymers, and the like.
  • the content of ⁇ -olefin in the ethylene / ⁇ -olefin copolymer is preferably 5 to 40% by mass, more preferably 10 to 35% by mass, and still more preferably 15 to 30% by mass. If the ⁇ -olefin content is small, the solar cell sealing film may have insufficient flexibility and impact resistance, and if it is too much, the heat resistance may be low.
  • the metallocene catalyst for polymerizing m-LLPDE a known metallocene catalyst may be used, and there is no particular limitation.
  • the metallocene catalyst is generally a compound having a structure in which a transition metal such as titanium, zirconium or hafnium is sandwiched between unsaturated cyclic compounds containing a ⁇ -electron cyclopentadienyl group or a substituted cyclopentadienyl group.
  • a promoter such as an aluminum compound such as alkylaluminoxane, alkylaluminum, aluminum halide, and alkylaluminum halide.
  • Metallocene catalysts are characterized by a uniform active site (single site catalyst), and usually a polymer having a narrow molecular weight distribution and an approximately equal comonomer content of each molecule is obtained.
  • the molecular weight distribution Mw / Mn is preferably 2.0 to 3.5.
  • the density of m-LLDPE is not particularly limited, but is preferably 0.860 to 0.930 g / cm 3 .
  • the melt flow rate (MFR) of m-LLDPE is not particularly limited, but is preferably 1.0 g / 10 min or more, more preferably 1.0 to 50.0 g / 10 min. 3.0 to 30.0 g / 10 min is more preferable.
  • MFR is measured on condition of 190 degreeC and load 21.18N.
  • m-LLDPE commercially available m-LLDPE may be used.
  • Harmolex series Kernel series manufactured by Nippon Polyethylene Co., Ltd., Evolution series manufactured by Prime Polymer Co., Ltd., Excellen GMH series, Excellen FX series manufactured by Sumitomo Chemical Co., Ltd. and the like can be mentioned.
  • Examples of the polar monomer of the ethylene-polar monomer copolymer include unsaturated carboxylic acid, its salt, its ester, its amide, vinyl ester, carbon monoxide and the like.
  • unsaturated carboxylic acids such as acrylic acid, methacrylic acid, fumaric acid, itaconic acid, monomethyl maleate, monoethyl maleate, maleic anhydride, itaconic anhydride, lithium of these unsaturated carboxylic acids, sodium, Salts of monovalent metals such as potassium, salts of polyvalent metals such as magnesium, calcium and zinc, methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, n-butyl acrylate, isooctyl acrylate, methacrylic acid
  • unsaturated carboxylic acid esters such as methyl, ethyl methacrylate, isobutyl methacrylate, and dimethyl maleate
  • vinyl esters such as vinyl acetate and vinyl propionate, carbon monoxide, sulfur dioxide, etc. be able to.
  • ethylene-polar monomer copolymer examples include ethylene-acrylic acid copolymers, ethylene-unsaturated carboxylic acid copolymers such as ethylene-methacrylic acid copolymers, and ethylene-unsaturated carboxylic acids.
  • Ionomers in which some or all of the carboxyl groups of the copolymer are neutralized with the above metals ethylene-methyl acrylate copolymers, ethylene-ethyl acrylate copolymers, ethylene-methyl methacrylate copolymers, ethylene- Isobutyl acrylate copolymer, ethylene-unsaturated carboxylic acid ester copolymer such as ethylene-n-butyl acrylate copolymer, ethylene-isobutyl acrylate-methacrylic acid copolymer, ethylene-n-butyl acrylate -Ethylene-unsaturated carboxylic acid ester-unsaturated carbo such as methacrylic acid copolymer
  • Typical examples include acid copolymers and ionomers in which some or all of the carboxyl groups have been neutralized with the above metals, ethylene-vinyl ester copolymers such as ethylene-vinyl acetate copolymers
  • the ethylene-polar monomer copolymer it is preferable to use a copolymer having a melt flow rate specified by JIS K7210 of 35 g / 10 min or less, particularly 3 to 6 g / 10 min.
  • a solar cell sealing film having excellent processability can be obtained.
  • the value of the melt flow rate (MFR) is measured based on the conditions of 190 ° C. and a load of 21.18 N according to JIS K7210.
  • ethylene-polar monomer copolymers examples include ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl methacrylate copolymer, and ethylene-methyl acrylate copolymer.
  • EVA ethylene-vinyl acetate copolymer
  • EMMA ethylene-methyl methacrylate copolymer
  • EMMA ethylene-ethyl methacrylate copolymer
  • ethylene-methyl acrylate copolymer examples include ethylene-methyl acrylate copolymer.
  • Ethylene-ethyl acrylate copolymer is preferable, and EVA and EMMA are particularly preferable.
  • the content of vinyl acetate in EVA is preferably 20 to 35% by mass, more preferably 22 to 32% by mass, and particularly preferably 24 to 30% by mass. If the vinyl acetate content is less than 20% by mass, the adhesiveness of the sealing film may be insufficient. If it exceeds 35% by mass, carboxylic acid, alcohol, amine, etc. are generated, and current leakage is likely to occur. There is a fear.
  • the sealing resin not only the above-mentioned olefin (co) polymer but also a resin such as polyvinyl acetal resin (for example, polyvinyl formal, polyvinyl butyral (PVB resin), modified PVB) is used as the sealing resin. It may also be used in combination with the olefin (co) polymer described above.
  • the density of the sealing resin may be, for example, 0.85 to 1 g / cm 3 , particularly 0.87 to 0.94 g / cm 3 .
  • the solar cell sealing film of the present invention preferably contains a crosslinking agent to form a crosslinked structure of an ethylene-polar monomer copolymer.
  • a crosslinking agent an organic peroxide or a photopolymerization initiator is preferably used.
  • an organic peroxide because a sealing film with improved temperature dependency of adhesive strength, moisture resistance, and penetration resistance can be obtained.
  • Any organic peroxide may be used as long as it decomposes at a temperature of 100 ° C. or higher and generates radicals.
  • the organic peroxide is generally selected in consideration of the film formation temperature, the adjustment conditions of the composition, the curing temperature, the heat resistance of the adherend, and the storage stability. In particular, those having a decomposition temperature of 70 hours or more with a half-life of 10 hours are preferred.
  • organic peroxide examples include, from the viewpoint of processing temperature and storage stability of the resin, for example, benzoyl peroxide curing agent, tert-hexyl peroxypivalate, tert-butyl peroxypivalate, 3, 5, 5- Trimethylhexanoyl peroxide, di-n-octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, succinic acid peroxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane, 1-cyclohexyl-1-methylethyl Peroxy-2-ethylhexanoate, tert-hexylpa Oxy-2-ethylhexano
  • benzoyl peroxide-based curing agent any can be used as long as it decomposes at a temperature of 70 ° C. or higher to generate radicals, and those having a decomposition temperature of 50 hours or higher with a half-life of 10 hours are preferable, It can be appropriately selected in consideration of preparation conditions, film formation temperature, curing (bonding) temperature, heat resistance of the adherend, and storage stability.
  • Usable benzoyl peroxide curing agents include, for example, benzoyl peroxide, 2,5-dimethylhexyl-2,5-bisperoxybenzoate, p-chlorobenzoyl peroxide, m-toluoyl peroxide, 2, Examples include 4-dichlorobenzoyl peroxide and t-butyl peroxybenzoate.
  • the benzoyl peroxide curing agent may be used alone or in combination of two or more.
  • the organic peroxide 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane or tert-butylperoxy-2-ethylhexyl monocarbonate is particularly preferable.
  • crosslinked favorably and has the outstanding transparency is obtained.
  • the content of the organic peroxide used in the sealing film for solar cells is preferably 0.1 to 5 parts by weight, more preferably 0.2 to 3 parts by weight with respect to 100 parts by weight of the sealing resin. Preferably there is. If the content of the organic peroxide is small, the crosslinking speed may be lowered during the crosslinking and curing, and if the content is large, the compatibility with the copolymer may be deteriorated.
  • photopolymerization initiator any known photopolymerization initiator can be used, but a photopolymerization initiator having good storage stability after blending is desirable.
  • photopolymerization initiators include 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, and 2-methyl-1- (4- (methylthio) phenyl).
  • Acetophenone series such as -2-morpholinopropane-1
  • benzoin series such as benzyldimethyl ketal
  • benzophenone series such as benzophenone, 4-phenylbenzophenone, hydroxybenzophenone, thioxanthone series such as isopropylthioxanthone, 2-4-diethylthioxanthone
  • methylphenylglyoxylate can be used.
  • 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropane-1 examples include benzophenone.
  • photopolymerization initiators may contain one or more known photopolymerization accelerators such as benzoic acid-based or tertiary amine-based compounds such as 4-dimethylaminobenzoic acid, if necessary. Can be mixed and used. Moreover, it can be used individually by 1 type of only a photoinitiator, or 2 or more types of mixture.
  • the content of the photopolymerization initiator is 0.1 to 5 parts by mass, preferably 0.2 to 3 parts by mass with respect to 100 parts by mass of the sealing resin.
  • the sealing film for solar cells of the present invention further contains a crosslinking aid.
  • the crosslinking aid can improve the gel fraction of the sealing resin and improve the adhesion and weather resistance of the solar cell sealing film.
  • the content of the crosslinking aid is usually 0.1 to 5 parts by weight, preferably 0.1 to 3 parts by weight, particularly preferably 0.5 to 2.5 parts by weight with respect to 100 parts by weight of the sealing resin. Used in. Thereby, the sealing film which the hardness after bridge
  • crosslinking aid compound having a radical polymerizable group as a functional group
  • examples of the crosslinking aid include trifunctional crosslinking aids such as triallyl cyanurate and triallyl isocyanurate, and (meth) acrylic esters (eg, NK ester) ) Monofunctional or bifunctional crosslinking aids.
  • trifunctional crosslinking aids such as triallyl cyanurate and triallyl isocyanurate, and (meth) acrylic esters (eg, NK ester) ) Monofunctional or bifunctional crosslinking aids.
  • triallyl cyanurate and triallyl isocyanurate are preferable, and triallyl isocyanurate is particularly preferable.
  • the solar cell sealing film of the present invention may further contain an adhesion improver.
  • an adhesion improver a silane coupling agent can be used. Thereby, it can be set as the sealing film for solar cells which has the further outstanding adhesive force.
  • the silane coupling agent include ⁇ -chloropropyltrimethoxysilane, vinyltriethoxysilane, vinyltris ( ⁇ -methoxyethoxy) silane, ⁇ -methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, and ⁇ -glycidoxypropyl.
  • the content of the silane coupling agent in the solar cell sealing film of the present invention is preferably 5 parts by mass or less, preferably 0.1 to 2 parts by mass with respect to 100 parts by mass of the sealing resin.
  • the sealing film for solar cells of the present invention improves or adjusts various physical properties of the film (optical properties such as mechanical strength and transparency, heat resistance, light resistance, crosslinking speed, etc.), especially improvement of mechanical strength. Therefore, if necessary, various additives such as a plasticizer, an acryloxy group-containing compound, a methacryloxy group-containing compound and / or an epoxy group-containing compound may further be included.
  • the composition containing each of the above-described components can be produced by a method of obtaining a sheet-like material by molding by ordinary extrusion molding, calendar molding (calendering) or the like.
  • the thickness of the solar cell sealing film of the present invention is not particularly limited, but is 0.05 to 2 mm, preferably 0.3 to 0.8 mm, and more preferably 0.4 to 0.7 mm.
  • the structure of the solar cell of the present invention is not particularly limited as long as it includes a structure manufactured by sealing the power generation element using the solar cell sealing film of the present invention.
  • the substance causing the PID phenomenon is captured by the crystalline porous aluminosilicate particles, and more than bifunctional (meta ) Due to the synergistic effect when used in combination with an acrylate compound, the PID phenomenon is extremely unlikely to occur, and even when used in a large-scale solar power generation facility, it is possible to maintain a sufficient power generation capacity for a long period of time. For example, it is useful as a solar cell that constitutes a solar power generation system having a high system voltage of 600 V or higher.
  • the side (light-receiving surface side) where the light of the solar cell is irradiated is referred to as “front surface side”, and the side opposite to the light-receiving surface of the solar cell is referred to as “back surface side”.
  • the front surface side transparent protective member 11 the front surface side sealing film 13A, the power generation element 14, the back surface side sealing film 13B, and the back surface side
  • the protective member 12 may be laminated, and the sealing film may be cross-linked and cured according to a conventional method such as heat and pressure.
  • a laminated body in which each member is laminated is heated at a temperature of 135 to 180 ° C., further 140 to 180 ° C., a degassing time of 0.1 to 5 minutes, and a press pressure of 0.1 to 1.
  • Heat pressing may be performed at 5 kg / cm 2 and a press time of 5 to 15 minutes.
  • the power generation element 14 can be sealed by integrating the side transparent protection member 11, the back surface side transparent member 12, and the power generation element 14.
  • the power generation elements 14 are electrically connected to each other by connection tabs 15.
  • the solar cell sealing film of the present invention is not limited to a solar cell using a single crystal or polycrystalline silicon crystal solar cell as shown in FIG. It can also be used for a sealing film of a thin film solar cell such as a solar cell and a copper indium selenide (CIS) solar cell.
  • the solar cell of the present invention is formed on a thin film solar cell element layer formed by a chemical vapor deposition method or the like on the surface of a surface side transparent protective member such as a glass substrate, a polyimide substrate, or a fluororesin transparent substrate.
  • the structure for laminating the battery sealing film and the back surface side protective member and adhering and integrating them On the solar cell element formed on the surface of the back surface side protective member, the structure for laminating the battery sealing film and the back surface side protective member and adhering and integrating them, the front surface side Laminated transparent protective member, bonded and integrated structure, or front side transparent protective member, front side sealing film, thin film solar cell element, back side sealing film, and back side protective member are laminated in this order, For example, a structure that is bonded and integrated.
  • the cell for solar cells and a thin film solar cell element are named generically, and it is called an electric power generation element.
  • the surface side transparent protective member 11 is usually a glass substrate such as silicate glass.
  • the thickness of the glass substrate is generally from 0.1 to 10 mm, and preferably from 0.3 to 5 mm.
  • the glass substrate may generally be chemically or thermally strengthened.
  • the back side protective member 12 is preferably a plastic film such as polyethylene terephthalate (PET) or polyamide. Further, a film obtained by laminating a fluorinated polyethylene film, particularly a fluorinated polyethylene film / Al / fluorinated polyethylene film in this order in consideration of heat resistance and wet heat resistance may be used. Further, a glass plate may be used.
  • PET polyethylene terephthalate
  • a film obtained by laminating a fluorinated polyethylene film, particularly a fluorinated polyethylene film / Al / fluorinated polyethylene film in this order in consideration of heat resistance and wet heat resistance may be used. Further, a glass plate may be used.
  • the sealing film for solar cells of this invention has the characteristics in the sealing film used for the surface side and / or back surface side of a solar cell (a thin film solar cell is included). Therefore, the members other than the sealing film such as the front surface side transparent protective member, the back surface side protective member, and the solar battery cell are not particularly limited as long as they have the same configuration as a conventionally known solar battery.
  • PID test output retention rate
  • the solar cell sealing film obtained above is used as a front-side sealing film and a back-side sealing film, and for solar cells between the front-side transparent protective member (glass plate) and the back-side protective member (PET film).
  • a solar cell mini-module in which four cells for solar cells were connected was manufactured by heating and pressing with the cells sandwiched.
  • As a model test for generating a PID phenomenon the output terminal of a module short-circuited at a temperature of 85 ° C.
  • EVA vinyl acetate content 26 mass%
  • Cross-linking agent t-butylperoxy-2-ethylhexyl monocarbonate
  • Cross-linking aid triallyl isocyanurate light stabilizer: bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate
  • UV absorber 2-hydroxy-4-n-octoxybenzophenone adhesion improver: ⁇ -methacryloxypropyltrimethoxysilane crystalline porous aluminosilicate particle: zeolite particle (cation: potassium ion and sodium ion.
  • K + ion exchange rate sica / alumina ratio is different in each example

Landscapes

  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Photovoltaic Devices (AREA)

Abstract

Provided is a sealing film for solar cells, which is capable of suppressing the occurrence of a PID phenomenon of a solar cell. Sealing films 13A, 13B for solar cells, each of which contains a sealing resin, crystalline porous aluminosilicate particles, and a bi- or higher functional (meth)acrylate compound.

Description

太陽電池用封止膜及びこれを用いた太陽電池Solar cell sealing film and solar cell using the same
　本発明は太陽電池用封止膜及びこれを用いた太陽電池に関する。 The present invention relates to a solar cell sealing film and a solar cell using the same.
　近年、資源の有効利用や環境汚染の防止等の面から、太陽光を電気エネルギーに直接変換する太陽電池が広く使用され、更に、耐久性や発電効率等の点から開発が進められている。 In recent years, solar cells that directly convert sunlight into electrical energy have been widely used from the standpoints of effective use of resources and prevention of environmental pollution, and are being developed from the viewpoint of durability and power generation efficiency.
　太陽電池の構造としては、例えば、図１に示すように、ガラス基板等からなる受光面側透明保護部材１１、受光面側封止膜１３Ａ、シリコン結晶系セル等の発電素子１４、裏面側封止膜１３Ｂ、及び裏面側保護部材（バックカバー）１２をこの順で積層し、接着一体化した構造が知られている。 As the structure of the solar cell, for example, as shown in FIG. 1, the light receiving surface side transparent protective member 11 made of a glass substrate or the like, the light receiving surface side sealing film 13A, the power generation element 14 such as a silicon crystal cell, the back surface side sealing A structure in which the stop film 13B and the back surface side protection member (back cover) 12 are laminated in this order and bonded and integrated is known.
　太陽電池では、高い電気出力を得るために、複数の発電素子１４を接続タブ１５で接続して用いられている。したがって、発電素子１４の絶縁性を確保するために、絶縁性のある封止膜１３Ａ、１３Ｂを用いて発電素子を封止している。 In solar cells, a plurality of power generating elements 14 are connected by connection tabs 15 in order to obtain a high electrical output. Therefore, in order to ensure the insulation of the power generation element 14, the power generation element is sealed using the insulating sealing films 13A and 13B.
　これらの太陽電池に用いられる封止膜としては、エチレン－酢酸ビニル共重合体（ＥＶＡ）、エチレン－エチルアクリレート共重合体（ＥＥＡ）等のオレフィン系共重合体やポリビニルブチラールからなるフィルムが従来から用いられている。特に、安価であり、高い透明性を有することからＥＶＡフィルムが好ましく用いられている。そして、封止膜用のＥＶＡフィルムは、膜強度や耐久性を向上させるために、ＥＶＡの他に有機過酸化物等の架橋剤を用いて架橋密度を向上させている（例えば特許文献１）。 As sealing films used in these solar cells, olefin copolymers such as ethylene-vinyl acetate copolymer (EVA) and ethylene-ethyl acrylate copolymer (EEA), and films made of polyvinyl butyral have been conventionally used. It is used. In particular, EVA films are preferably used because they are inexpensive and have high transparency. And the EVA film for sealing films has improved the crosslinking density using crosslinking agents, such as an organic peroxide, other than EVA, in order to improve film | membrane intensity | strength and durability (for example, patent document 1). .
　近年、１ＭＷ以上の出力を有するメガソーラーと呼ばれる大規模太陽光発電設備が増加しており、送電系の効率化等の理由から高いシステム電圧が要求され、システム電圧が６００Ｖ以上、特に１０００Ｖ以上のメガソーラーも建設されている。 In recent years, a large-scale photovoltaic power generation facility called a mega solar having an output of 1 MW or more is increasing, and a high system voltage is required for reasons such as efficiency improvement of the transmission system. The system voltage is 600 V or more, particularly 1000 V or more. Mega solar is also being built.
　最近、このような高いシステム電圧の太陽光発電設備において、従来の太陽電池モジュールには見られなかったＰＩＤ（Potential　Induced　Degradation）現象と呼ばれる太陽電池モジュールの性能劣化が発生することが問題となっている。ＰＩＤ現象とは、太陽電池モジュールの内部回路で電荷の分極が生じ、セル内部での電子の移動が妨げられることで出力の著しい低下が起こる現象である。これは、システム電圧が高電圧化した太陽光発電設備においては、接地されたフレームと太陽電池モジュール内部回路との間に大きな電位差が発生するようになり、これに湿度、温度等の外部要因が作用し、モジュールの内部回路とフレーム間に漏れ電流が生じることが原因といわれている。ＰＩＤ現象は太陽電池モジュールの各部材の相互作用により発生するため、その発生を抑制するための条件等については未だ明らかになっていない。 Recently, in such a high system voltage photovoltaic power generation facility, there has been a problem that the performance degradation of the solar cell module called PID (Potential Induced Degradation) phenomenon, which was not seen in the conventional solar cell module, has occurred. Yes. The PID phenomenon is a phenomenon in which output polarization is significantly reduced by polarization of electric charge in the internal circuit of the solar cell module and hindering movement of electrons inside the cell. This is because, in a photovoltaic power generation facility where the system voltage is increased, a large potential difference occurs between the grounded frame and the internal circuit of the solar cell module, and external factors such as humidity and temperature are caused by this. It is said that this is caused by a leakage current between the internal circuit of the module and the frame. Since the PID phenomenon occurs due to the interaction of each member of the solar cell module, the conditions for suppressing the occurrence have not yet been clarified.
特開２０１２－１７４８８１号公報JP2012-174881A
　本発明の目的は、ＰＩＤ現象の発生を抑制することができる太陽電池用封止膜を提供することにある。 An object of the present invention is to provide a solar cell sealing film that can suppress the occurrence of the PID phenomenon.
　上記目的は、封止用樹脂、結晶性多孔質アルミノケイ酸塩粒子、及び２官能以上の（メタ）アクリレート化合物を含む太陽電池用封止膜により達成される。 The above object is achieved by a sealing film for a solar cell including a sealing resin, crystalline porous aluminosilicate particles, and a bifunctional or higher functional (meth) acrylate compound.
　本発明の好ましい態様は以下のとおりである。 Preferred embodiments of the present invention are as follows.
　（１）前記（メタ）アクリレート化合物が－(ＣｎＨ２ｎＯ）－鎖（但し、ｎは２～５の整数である。）を有する。
　（２）前記（メタ）アクリレート化合物は下記式（Ｉ）
Figure JPOXMLDOC01-appb-C000002
 　（但し、Ｒはそれぞれ独立して水素原子又はメチル基であり、mは２～２０の整数である。）
で表されるジ（メタ）アクリレート化合物である。
　（３）前記結晶性多孔質アルミノケイ酸塩粒子の含有量が、前記封止用樹脂１００質量部に対して０．０５～１質量部であり、前記（メタ）アクリレート化合物の含有量が、前記封止用樹脂１００質量部に対して０．０５～１質量部である。ＰＩＤ現象の発生を効果的に抑制できると共に、透明性にも優れる太陽電池用封止膜が得られる。
　（４）前記結晶性多孔質アルミノケイ酸塩粒子の含有量が、前記封止用樹脂１００質量部に対して０．１～０．３質量部であり、前記（メタ）アクリレート化合物の含有量が、前記封止用樹脂１００質量部に対して０．２～０．４質量部である。更に透明性やＰＩＤ現象の発生抑制効果に優れる太陽電池用封止膜が得られる。
　（５）シリカ／アルミナ比が１～５である。ＰＩＤ現象発生抑制効果に更に優れる。
　（６）前記（メタ）アクリレート化合物に対する前記結晶性多孔質アルミノケイ酸塩粒子の質量比が０．０５～２０である。
　（７）前記結晶性多孔質アルミノケイ酸塩が陽イオンを含有し、前記陽イオンの少なくとも一部は、ナトリウムイオンを除くアルカリ金属イオン、アルカリ土類金属イオン及びマグネシウムイオンからなる群から選択される少なくとも１種である。
　（８）前記陽イオンの少なくとも一部は、カリウムイオンである。
　（９）陽イオンとして、ナトリウムイオンを更に含む。
　（１０）前記カリウムイオンとナトリウムイオンの合計量に対するカリウムイオンの割合が３０～６０ｍｏｌ％である。 (1) The (meth) acrylate compound has a — (C n H 2n O) — chain (where n is an integer of 2 to 5).
(2) The (meth) acrylate compound has the following formula (I)
Figure JPOXMLDOC01-appb-C000002
 (However, each R is independently a hydrogen atom or a methyl group, and m is an integer of 2 to 20.)
It is a di (meth) acrylate compound represented by these.
(3) The content of the crystalline porous aluminosilicate particles is 0.05 to 1 part by mass with respect to 100 parts by mass of the sealing resin, and the content of the (meth) acrylate compound is The amount is 0.05 to 1 part by mass with respect to 100 parts by mass of the sealing resin. The solar cell sealing film that can effectively suppress the occurrence of the PID phenomenon and is excellent in transparency can be obtained.
(4) The content of the crystalline porous aluminosilicate particles is 0.1 to 0.3 parts by mass with respect to 100 parts by mass of the sealing resin, and the content of the (meth) acrylate compound is The amount is 0.2 to 0.4 parts by mass with respect to 100 parts by mass of the sealing resin. Furthermore, the sealing film for solar cells which is excellent in transparency and the generation | occurrence | production suppression effect of a PID phenomenon is obtained.
(5) The silica / alumina ratio is 1-5. It is further superior in suppressing the occurrence of PID phenomenon.
(6) The mass ratio of the crystalline porous aluminosilicate particles to the (meth) acrylate compound is 0.05 to 20.
(7) The crystalline porous aluminosilicate contains a cation, and at least a part of the cation is selected from the group consisting of alkali metal ions excluding sodium ions, alkaline earth metal ions, and magnesium ions. At least one.
(8) At least some of the cations are potassium ions.
(9) Sodium ions are further included as cations.
(10) The ratio of potassium ions to the total amount of potassium ions and sodium ions is 30 to 60 mol%.
　また、上記目的は、本発明の太陽電池用封止膜を用いて発電素子を封止することにより製造された太陽電池によっても達成される。 The above object is also achieved by a solar cell manufactured by sealing a power generation element using the solar cell sealing film of the present invention.
　本発明の太陽電池用封止膜を用いて作製された太陽電池はＰＩＤ現象が発生しにくく、大規模太陽光発電設備に用いた場合であっても長期に亘り十分な発電能力を維持することが可能である。 The solar cell produced using the solar cell sealing film of the present invention is less prone to the PID phenomenon, and maintains a sufficient power generation capacity for a long time even when used in a large-scale solar power generation facility. Is possible.
一般的な太陽電池モジュールの概略断面図である。It is a schematic sectional drawing of a common solar cell module.
　上述したように、本発明の太陽電池用封止膜は、封止用樹脂、結晶性多孔質アルミノケイ酸塩粒子及び２官能以上の（メタ）アクリレート化合物を含む。以下、本発明を詳細に説明する。 As described above, the solar cell sealing film of the present invention includes a sealing resin, crystalline porous aluminosilicate particles, and a bifunctional or higher functional (meth) acrylate compound. Hereinafter, the present invention will be described in detail.
　［結晶性多孔質アルミノケイ酸塩粒子］
　本発明において結晶性多孔質アルミノケイ酸塩粒子はどのようなものでもよい。一般に、結晶性多孔質アルミノケイ酸塩は下記式（ＩＩ）で表される。
　　Ｍ２／ｎＯ・Ａｌ２Ｏ３・ｙＳｉＯ２・ｚＨ２Ｏ　　　　　　（ＩＩ） [Crystalline porous aluminosilicate particles]
In the present invention, any crystalline porous aluminosilicate particles may be used. Generally, a crystalline porous aluminosilicate is represented by the following formula (II).
M 2 / n O · Al 2 O 3 · ySiO 2 · zH 2 O (II)
　式中、Ｍは陽イオンを表し、ｎは陽イオンＭの価数を表し、ｙはシリカ／アルミナ比に相当し、通常１～１００、好ましくは１～１０、特に好ましくは１～５である。ｚは細孔に含まれる水分子の数であり、通常は０以上の数、好ましくは０～２０である。陽イオンＭはアルカリ金属、アルカリ土類金属及びマグネシウムイオンが好ましく、例えば、カルシウムイオン、バリウムイオン、カリウムイオン、ナトリウムイオン等が挙げられ、これらの２種以上の組み合わせであってもよい。 In the formula, M represents a cation, n represents a valence of the cation M, and y corresponds to a silica / alumina ratio, and is usually 1 to 100, preferably 1 to 10, particularly preferably 1 to 5. . z is the number of water molecules contained in the pores, and is usually a number of 0 or more, preferably 0-20. The cation M is preferably an alkali metal, an alkaline earth metal, or a magnesium ion, and examples thereof include calcium ion, barium ion, potassium ion, and sodium ion, and may be a combination of two or more of these.
　本発明では、陽イオンの少なくとも一部が、ナトリウムイオンを除くアルカリ金属イオン、アルカリ土類金属イオン及びマグネシウムイオンからなる群から選択される少なくとも１種であることが好ましい。これにより、ＰＩＤ現象の発生を更に確実に防止することができる。 In the present invention, it is preferable that at least a part of the cations is at least one selected from the group consisting of alkali metal ions excluding sodium ions, alkaline earth metal ions, and magnesium ions. Thereby, generation | occurrence | production of a PID phenomenon can be prevented further reliably.
　陽イオンの少なくとも一部はカリウムイオンであることが特に好ましい。さらに、陽イオンとして、上述した少なくとも一部の陽イオンの他に、ナトリウムイオンも含んでいることが特に好ましい。そして、本発明では、陽イオンとして、ナトリウムイオンとカリウムイオンの両方を含んでいることが更に好ましく、この場合、ナトリウムイオンとカリウムイオンの合計量に対するカリウムイオン含有量は３０～６０ｍｏｌ％であることが好ましく、更に３０～４５ｍｏｌ％であることが特に好ましい。この範囲より低いとＰＩＤ現象の発生防止効果が小さくなる場合があり、この範囲より高いとバックシート側において発泡が発生する場合がある。 It is particularly preferable that at least a part of the cation is a potassium ion. Further, it is particularly preferable that the cation contains sodium ion in addition to at least a part of the cation described above. In the present invention, it is further preferable that both sodium ions and potassium ions are contained as cations. In this case, the potassium ion content is 30 to 60 mol% with respect to the total amount of sodium ions and potassium ions. And more preferably 30 to 45 mol%. If it is lower than this range, the effect of preventing the occurrence of the PID phenomenon may be reduced, and if it is higher than this range, foaming may occur on the back sheet side.
　結晶性多孔質アルミノケイ酸塩の結晶構造は、Ｌ型、Ｘ型、Ａ型、Ｙ型等いずれの結晶構造でもよい。結晶性多孔質アルミノケイ酸塩は１種を単独で用いてもよく、２種以上を組み合せて用いてもよい。 The crystal structure of the crystalline porous aluminosilicate may be any crystal structure such as L-type, X-type, A-type, and Y-type. One type of crystalline porous aluminosilicate may be used alone, or two or more types may be used in combination.
　結晶性多孔質アルミノケイ酸塩粒子は、封止用樹脂１００質量部に対して、通常０．０５～５質量部、好ましくは０．０５～１質量部、より好ましくは０．１～０．５質量部、更に好ましくは０．１～０．３質量部の量で配合する。この範囲より少ないとＰＩＤ抑制効果が得られない恐れがあり、この範囲より多いと太陽電池用封止膜の透明性が低下する場合がある。 The crystalline porous aluminosilicate particles are usually 0.05 to 5 parts by mass, preferably 0.05 to 1 part by mass, more preferably 0.1 to 0.5 parts by mass with respect to 100 parts by mass of the sealing resin. It is blended in an amount of part by mass, more preferably 0.1 to 0.3 part by mass. If the amount is less than this range, the PID suppressing effect may not be obtained. If the amount is more than this range, the transparency of the solar cell sealing film may decrease.
　結晶性多孔質アルミノケイ酸塩粒子の平均粒子径は例えば１～５０μｍである。なお、本発明において、結晶性多孔質アルミノケイ酸塩粒子の平均粒子径は、レーザー回折散乱法によって求めた粒度分布（体積平均）における５０％粒子径のことをいう。本発明において、結晶性アルミノケイ酸塩粒子は、ゼオライトとして市販されているものを使用することができる。 The average particle diameter of the crystalline porous aluminosilicate particles is, for example, 1 to 50 μm. In the present invention, the average particle size of the crystalline porous aluminosilicate particles refers to the 50% particle size in the particle size distribution (volume average) determined by the laser diffraction scattering method. In the present invention, as the crystalline aluminosilicate particles, those commercially available as zeolite can be used.
　［２官能以上の（メタ）アクリレート化合物］
　上述したように、本発明の太陽電池用封止膜は２官能以上の（メタ）アクリレート化合物（（メタ）アクリロイルオキシ基を２個以上有する化合物）を含む。好ましくは２～６官能のものであり、より好ましくは２～４官能のものである。（メタ）アクリロイルオキシ基以外の官能基は有しないことが好ましい。 [Bifunctional or higher (meth) acrylate compound]
As described above, the solar cell sealing film of the present invention contains a bifunctional or higher functional (meth) acrylate compound (a compound having two or more (meth) acryloyloxy groups). A bifunctional to hexafunctional one is preferred, and a bifunctional to tetrafunctional one is more preferred. It is preferable that no functional group other than the (meth) acryloyloxy group is present.
　好ましい２官能以上の（メタ）アクリレート化合物は、－(ＣｎＨ２ｎＯ）－鎖（ｎは２～５の整数、好ましくは２又は３）を有する２官能以上の（メタ）アクリレート化合物である。－(ＣｎＨ２ｎＯ）－鎖は好ましくはポリエチレングリコール鎖、ポリプロピレングリコール鎖である。－(ＣｎＨ２ｎＯ）－鎖の繰り返し単位数は２～２０であることが好ましい。更に好ましい（メタ）アクリレート化合物は、下記式（Ｉ）で表されるジ（メタ）アクリレート化合物である。 A preferred bifunctional or higher functional (meth) acrylate compound is a bifunctional or higher functional (meth) acrylate compound having a — (C n H 2n O) — chain (n is an integer of 2 to 5, preferably 2 or 3). . The — (C n H 2n O) — chain is preferably a polyethylene glycol chain or a polypropylene glycol chain. The number of repeating units of the — (C n H 2n O) — chain is preferably 2 to 20. A more preferable (meth) acrylate compound is a di (meth) acrylate compound represented by the following formula (I).
Figure JPOXMLDOC01-appb-C000003
 　（但し、Ｒはそれぞれ独立して水素原子又はメチル基、好ましくはメチル基であり、ｍは２～２０の整数、好ましくは５～１４の整数、より好ましくは７～１２の整数である。）
Figure JPOXMLDOC01-appb-C000003
 (However, each R is independently a hydrogen atom or a methyl group, preferably a methyl group, and m is an integer of 2 to 20, preferably an integer of 5 to 14, more preferably an integer of 7 to 12.)
　２官能以上の（メタ）アクリレート化合物の他の具体例としては、ペンタエリスリトールテトラ（メタ）アクリレート、ジペンタエリスリトールヘキサ（メタ）アクリレート、トリメチロールプロパントリ（メタ）アクリレート、ＥＯ変性トリメチロールプロパントリ（メタ）アクリレート等が挙げられる。 Other specific examples of the bifunctional or higher functional (meth) acrylate compound include pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, trimethylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri ( And (meth) acrylate.
　（メタ）アクリレート化合物の含有量は、封止用樹脂１００質量部に対して通常０．０５～１質量部、好ましくは０．２～０．４質量部である。この範囲より少ないとＰＩＤ現象を十分に抑制することができなくなる場合があり、この範囲より多いと太陽電池用封止膜を作製する際の加工性が低下する場合がある。 The content of the (meth) acrylate compound is usually 0.05 to 1 part by mass, preferably 0.2 to 0.4 part by mass with respect to 100 parts by mass of the sealing resin. If the amount is less than this range, the PID phenomenon may not be sufficiently suppressed. If the amount is more than this range, the workability in producing a solar cell sealing film may be reduced.
　本発明において、（メタ）アクリレート化合物に対する結晶性アルミノケイ酸塩粒子の質量比（結晶性アルミノケイ酸塩／（メタ）アクリレート化合物）は、０．０５～２０が好ましく、０．２５～４がより好ましく、１～２．５が更に好ましい。この範囲であればＰＩＤ減少抑制効果を効果的に得ることができる。 In the present invention, the mass ratio of crystalline aluminosilicate particles to (meth) acrylate compound (crystalline aluminosilicate / (meth) acrylate compound) is preferably 0.05 to 20, more preferably 0.25 to 4. 1 to 2.5 is more preferable. If it is this range, the PID reduction suppression effect can be acquired effectively.
　［封止用樹脂］
　本発明において、封止用樹脂は発電素子を封止できるものであればどのようなものでもよい。好ましい封止用樹脂としてオレフィン（共）重合体が挙げられる。オレフィン（共）重合体とは、エチレン・α－オレフィン共重合体（例えば、メタロセン触媒を用いて重合されたエチレン・α－オレフィン共重合体（ｍ－ＬＬＤＰＥ）等）、ポリエチレン（例えば、低密度ポリエチレン（ＬＤＰＥ）、直鎖状低密度ポリエチレン（ＬＬＤＰＥ）等）、ポリプロピレン、ポリブテン等のオレフィンの重合体又は共重合体、及びエチレン－極性モノマー共重合体等のオレフィンと極性モノマーとの共重合体を意味し、太陽電池用封止膜に要求される接着性、透明性等を有するものとする。オレフィン（共）重合体として、これらの１種を用いても良く、２種以上を混合して用いても良い。本発明において、オレフィン（共）重合体としては、メタロセン触媒を用いて重合されたエチレン・α－オレフィン共重合体（ｍ－ＬＬＤＰＥ）、低密度ポリエチレン（ＬＤＰＥ）、直鎖状低密度ポリエチレン（ＬＬＤＰＥ）、ポリプロピレン、ポリブテン及びエチレン－極性モノマー共重合体からなる群から選択される少なくとも１種以上の重合体であることが好ましい。特に、加工性に優れ、架橋剤による架橋構造を形成することができ、接着性が高い太陽電池用封止膜を形成することができることから、オレフィン（共）重合体が、メタロセン触媒を用いて重合されたエチレン・α－オレフィン共重合体（ｍ－ＬＬＤＰＥ）及び／又はエチレン－極性モノマー共重合体であることが好ましい。 [Resin for sealing]
In the present invention, the sealing resin may be any resin as long as it can seal the power generating element. A preferred sealing resin is an olefin (co) polymer. The olefin (co) polymer means an ethylene / α-olefin copolymer (for example, an ethylene / α-olefin copolymer (m-LLDPE) polymerized using a metallocene catalyst), polyethylene (for example, low density) Polymers or copolymers of olefins such as polyethylene (LDPE), linear low density polyethylene (LLDPE), polypropylene and polybutene, and copolymers of olefin and polar monomer such as ethylene-polar monomer copolymer It has the adhesiveness, transparency, etc. which are requested | required of the sealing film for solar cells. As the olefin (co) polymer, one of these may be used, or two or more may be mixed and used. In the present invention, as the olefin (co) polymer, an ethylene / α-olefin copolymer (m-LLDPE) polymerized using a metallocene catalyst, low density polyethylene (LDPE), linear low density polyethylene (LLDPE) is used. ), At least one polymer selected from the group consisting of polypropylene, polybutene, and ethylene-polar monomer copolymer. In particular, an olefin (co) polymer can be formed using a metallocene catalyst because it is excellent in processability, can form a crosslinked structure with a crosslinking agent, and can form a solar cell sealing film with high adhesion. A polymerized ethylene / α-olefin copolymer (m-LLDPE) and / or an ethylene-polar monomer copolymer is preferred.
　（メタロセン触媒を用いて重合されたエチレン・α－オレフィン共重合体（ｍ－ＬＬＤＰＥ））ｍ－ＬＬＤＰＥは、エチレン由来の構成単位を主成分とし、更に炭素数３～１２のα－オレフィン、例えば、プロピレン、１－ブテン、１-へキセン、１－オクテン、４－メチルペンテン－１、４－メチル－へキセン－１、４，４－ジメチル－ペンテン－１等由来の１種又は複数種の構成単位を有するエチレン・α－オレフィン共重合体（ターポリマー等も含む）である。エチレン・α－オレフィン共重合体の具体例としては、エチレン・１－ブテン共重合体、エチレン・１－オクテン共重合体、エチレン・４－メチル－ペンテン－１共重合体、エチレン・ブテン・ヘキセンターポリマー、エチレン・プロピレン・オクテンターポリマー、エチレン・ブテン・オクテンターポリマー等が挙げられる。エチレン・α－オレフィン共重合体におけるα－オレフィンの含有量は、５～４０質量％が好ましく、１０～３５質量％がより好ましく、１５～３０質量％が更に好ましい。α－オレフィンの含有量が少ないと太陽電池用封止膜の柔軟性や耐衝撃性が十分でない場合があり、多過ぎると耐熱性が低い場合がある。 (Ethylene / α-olefin copolymer polymerized using metallocene catalyst (m-LLDPE)) m-LLDPE is composed mainly of ethylene-derived constitutional units and further an α-olefin having 3 to 12 carbon atoms, such as , One or more kinds derived from propylene, 1-butene, 1-hexene, 1-octene, 4-methylpentene-1, 4-methyl-hexene-1, 4,4-dimethyl-pentene-1, etc. An ethylene / α-olefin copolymer having a structural unit (including a terpolymer). Specific examples of the ethylene / α-olefin copolymer include an ethylene / 1-butene copolymer, an ethylene / 1-octene copolymer, an ethylene-4-methyl-pentene-1 copolymer, an ethylene / butene / hexene copolymer. Center polymers, ethylene / propylene / octene terpolymers, ethylene / butene / octene terpolymers, and the like. The content of α-olefin in the ethylene / α-olefin copolymer is preferably 5 to 40% by mass, more preferably 10 to 35% by mass, and still more preferably 15 to 30% by mass. If the α-olefin content is small, the solar cell sealing film may have insufficient flexibility and impact resistance, and if it is too much, the heat resistance may be low.
　ｍ－ＬＬＰＤＥを重合するメタロセン触媒としては、公知のメタロセン触媒を用いれば良く、特に制限はない。メタロセン触媒は、一般に、チタン、ジルコニウム、ハフニウム等の遷移金属をπ電子系のシクロペンタジエニル基又は置換シクロペンタジエニル基等を含有する不飽和環状化合物で挟んだ構造の化合物であるメタロセン化合物と、アルキルアルミノキサン、アルキルアルミニウム、アルミニウムハライド、アルキルアルミニウムルハライド等のアルミニウム化合物等の助触媒とを組合せたものである。メタロセン触媒は、活性点が均一であるという特徴があり（シングルサイト触媒）、通常、分子量分布が狭く、各分子のコモノマー含有量がほぼ等しい重合体が得られる。分子量分布Ｍｗ／Ｍｎは２．０～３．５であることが好ましい。 As the metallocene catalyst for polymerizing m-LLPDE, a known metallocene catalyst may be used, and there is no particular limitation. The metallocene catalyst is generally a compound having a structure in which a transition metal such as titanium, zirconium or hafnium is sandwiched between unsaturated cyclic compounds containing a π-electron cyclopentadienyl group or a substituted cyclopentadienyl group. And a promoter such as an aluminum compound such as alkylaluminoxane, alkylaluminum, aluminum halide, and alkylaluminum halide. Metallocene catalysts are characterized by a uniform active site (single site catalyst), and usually a polymer having a narrow molecular weight distribution and an approximately equal comonomer content of each molecule is obtained. The molecular weight distribution Mw / Mn is preferably 2.0 to 3.5.
　本発明において、ｍ－ＬＬＤＰＥの密度（ＪＩＳ Ｋ ７１１２に準ずる。以下同じ）は、特に制限はないが、０．８６０～０．９３０ｇ／ｃｍ３が好ましい。また、ｍ－ＬＬＤＰＥのメルトフローレート（ＭＦＲ）（ＪＩＳ－Ｋ７２１０に準ずる）は、特に制限はないが、１．０ｇ／１０分以上が好ましく、１．０～５０．０ｇ／１０分がより好ましく、３．０～３０．０ｇ／１０分が更に好ましい。なお、ＭＦＲは、１９０℃、荷重２１．１８Ｎの条件で測定されたものである。 In the present invention, the density of m-LLDPE (according to JIS K 7112; the same applies hereinafter) is not particularly limited, but is preferably 0.860 to 0.930 g / cm 3 . The melt flow rate (MFR) of m-LLDPE (according to JIS-K7210) is not particularly limited, but is preferably 1.0 g / 10 min or more, more preferably 1.0 to 50.0 g / 10 min. 3.0 to 30.0 g / 10 min is more preferable. In addition, MFR is measured on condition of 190 degreeC and load 21.18N.
　本発明において、ｍ－ＬＬＤＰＥは市販のものを使用することもできる。例えば、日本ポリエチレン社製のハーモレックスシリーズ、カーネルシリーズ、プライムポリマー社製のエボリューシリーズ、住友化学社製のエクセレンＧＭＨシリーズ、エクセレンＦＸシリーズ等が挙げられる。 In the present invention, commercially available m-LLDPE may be used. For example, Harmolex series, Kernel series manufactured by Nippon Polyethylene Co., Ltd., Evolution series manufactured by Prime Polymer Co., Ltd., Excellen GMH series, Excellen FX series manufactured by Sumitomo Chemical Co., Ltd. and the like can be mentioned.
　（エチレン－極性モノマー共重合体）
　エチレン－極性モノマー共重合体の極性モノマーは、不飽和カルボン酸、その塩、そのエステル、そのアミド、ビニルエステル、一酸化炭素等を例示することができる。より具体的には、アクリル酸、メタクリル酸、フマル酸、イタコン酸、マレイン酸モノメチル、マレイン酸モノエチル、無水マレイン酸、無水イタコン酸等の不飽和カルボン酸、これら不飽和カルボン酸のリチウム、ナトリウム、カリウムなどの１価金属の塩やマグネシウム、カルシウム、亜鉛などの多価金属の塩、アクリル酸メチル、アクリル酸エチル、アクリル酸イソプロピル、アクリル酸イソブチル、アクリル酸ｎ－ブチル、アクリル酸イソオクチル、メタクリル酸メチル、メタクリル酸エチル、メタクリル酸イソブチル、マレイン酸ジメチル等の不飽和カルボン酸エステル、酢酸ビニル、プロピオン酸ビニルのようなビニルエステル、一酸化炭素、二酸化硫黄などの一種又は二種以上などを例示することができる。 (Ethylene-polar monomer copolymer)
Examples of the polar monomer of the ethylene-polar monomer copolymer include unsaturated carboxylic acid, its salt, its ester, its amide, vinyl ester, carbon monoxide and the like. More specifically, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, fumaric acid, itaconic acid, monomethyl maleate, monoethyl maleate, maleic anhydride, itaconic anhydride, lithium of these unsaturated carboxylic acids, sodium, Salts of monovalent metals such as potassium, salts of polyvalent metals such as magnesium, calcium and zinc, methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, n-butyl acrylate, isooctyl acrylate, methacrylic acid Examples include unsaturated carboxylic acid esters such as methyl, ethyl methacrylate, isobutyl methacrylate, and dimethyl maleate, vinyl esters such as vinyl acetate and vinyl propionate, carbon monoxide, sulfur dioxide, etc. be able to.
　エチレン－極性モノマー共重合体として、より具体的には、エチレン－アクリル酸共重合体、エチレン－メタクリル酸共重合体のようなエチレン－不飽和カルボン酸共重合体、前記エチレン－不飽和カルボン酸共重合体のカルボキシル基の一部又は全部が上記金属で中和されたアイオノマー、エチレン－アクリル酸メチル共重合体、エチレン－アクリル酸エチル共重合体、エチレン－メタクリル酸メチル共重合体、エチレン－アクリル酸イソブチル共重合体、エチレン－アクリル酸ｎ－ブチル共重合体のようなエチレン－不飽和カルボン酸エステル共重合体、エチレン－アクリル酸イソブチル－メタクリル酸共重合体、エチレン－アクリル酸ｎ－ブチル－メタクリル酸共重合体のようなエチレン－不飽和カルボン酸エステル－不飽和カルボン酸共重合体及びそのカルボキシル基の一部又は全部が上記金属で中和されたアイオノマー、エチレン－酢酸ビニル共重合体のようなエチレン－ビニルエステル共重合体等を代表例として例示することができる。 More specific examples of the ethylene-polar monomer copolymer include ethylene-acrylic acid copolymers, ethylene-unsaturated carboxylic acid copolymers such as ethylene-methacrylic acid copolymers, and ethylene-unsaturated carboxylic acids. Ionomers in which some or all of the carboxyl groups of the copolymer are neutralized with the above metals, ethylene-methyl acrylate copolymers, ethylene-ethyl acrylate copolymers, ethylene-methyl methacrylate copolymers, ethylene- Isobutyl acrylate copolymer, ethylene-unsaturated carboxylic acid ester copolymer such as ethylene-n-butyl acrylate copolymer, ethylene-isobutyl acrylate-methacrylic acid copolymer, ethylene-n-butyl acrylate -Ethylene-unsaturated carboxylic acid ester-unsaturated carbo such as methacrylic acid copolymer Typical examples include acid copolymers and ionomers in which some or all of the carboxyl groups have been neutralized with the above metals, ethylene-vinyl ester copolymers such as ethylene-vinyl acetate copolymers, and the like. .
　エチレン－極性モノマー共重合体としては、ＪＩＳ　Ｋ７２１０で規定されるメルトフローレートが、３５ｇ／１０分以下、特に３～６ｇ／１０分のものを使用するのが好ましい。このようなメルトフローレートを有するエチレン－極性モノマー共重合体を用いることで、加工性に優れた太陽電池用封止膜とすることができる。なお、本発明において、メルトフローレート（ＭＦＲ）の値は、ＪＩＳ Ｋ７２１０に従い、１９０℃、荷重２１．１８Ｎの条件に基づいて測定されたものである。 As the ethylene-polar monomer copolymer, it is preferable to use a copolymer having a melt flow rate specified by JIS K7210 of 35 g / 10 min or less, particularly 3 to 6 g / 10 min. By using an ethylene-polar monomer copolymer having such a melt flow rate, a solar cell sealing film having excellent processability can be obtained. In the present invention, the value of the melt flow rate (MFR) is measured based on the conditions of 190 ° C. and a load of 21.18 N according to JIS K7210.
　エチレン－極性モノマー共重合体としては、エチレン－酢酸ビニル共重合体（ＥＶＡ）、エチレン－メタクリル酸メチル共重合体（ＥＭＭＡ）、エチレン－メタクリル酸エチル共重合体、エチレン－アクリル酸メチル共重合体、エチレン－アクリル酸エチル共重合体が好ましく、特にＥＶＡ及びＥＭＭＡが好ましい。 Examples of ethylene-polar monomer copolymers include ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl methacrylate copolymer, and ethylene-methyl acrylate copolymer. Ethylene-ethyl acrylate copolymer is preferable, and EVA and EMMA are particularly preferable.
　封止用樹脂としてＥＶＡを使用する場合、ＥＶＡにおける酢酸ビニルの含有率は、２０～３５質量％、さらに２２～３２質量％、特に２４～３０質量％とするのが好ましい。酢酸ビニルの含有量が２０質量％未満であると封止膜の接着性が十分でない恐れがあり、３５質量％を超えると、カルボン酸、アルコール、アミン等が発生し、電流のリークが生じやすくなる恐れがある。 When EVA is used as the sealing resin, the content of vinyl acetate in EVA is preferably 20 to 35% by mass, more preferably 22 to 32% by mass, and particularly preferably 24 to 30% by mass. If the vinyl acetate content is less than 20% by mass, the adhesiveness of the sealing film may be insufficient. If it exceeds 35% by mass, carboxylic acid, alcohol, amine, etc. are generated, and current leakage is likely to occur. There is a fear.
　なお、本発明において、封止用樹脂として、上述のオレフィン（共）重合体だけでなく、ポリビニルアセタール系樹脂（例えば、ポリビニルホルマール、ポリビニルブチラール（ＰＶＢ樹脂）、変性ＰＶＢ）等の樹脂を用いてもよく、上述のオレフィン（共）重合体と組合せて使用してもよい。なお、封止用樹脂の密度は例えば０．８５～１ｇ／ｃｍ３、特に０．８７～０．９４ｇ／ｃｍ３でよい。 In the present invention, not only the above-mentioned olefin (co) polymer but also a resin such as polyvinyl acetal resin (for example, polyvinyl formal, polyvinyl butyral (PVB resin), modified PVB) is used as the sealing resin. It may also be used in combination with the olefin (co) polymer described above. The density of the sealing resin may be, for example, 0.85 to 1 g / cm 3 , particularly 0.87 to 0.94 g / cm 3 .
　［架橋剤］
　本発明の太陽電池用封止膜には、架橋剤を含有させ、エチレン－極性モノマー共重合体の架橋構造を形成することが好ましい。架橋剤は、有機過酸化物又は光重合開始剤を用いることが好ましい。なかでも、接着力、耐湿性、耐貫通性の温度依存性が改善された封止膜が得られることから、有機過酸化物を用いるのが好ましい。 [Crosslinking agent]
The solar cell sealing film of the present invention preferably contains a crosslinking agent to form a crosslinked structure of an ethylene-polar monomer copolymer. As the crosslinking agent, an organic peroxide or a photopolymerization initiator is preferably used. Among these, it is preferable to use an organic peroxide because a sealing film with improved temperature dependency of adhesive strength, moisture resistance, and penetration resistance can be obtained.
　有機過酸化物としては、１００℃以上の温度で分解してラジカルを発生するものであれば、どのようなものでも使用することができる。有機過酸化物は、一般に、成膜温度、組成物の調整条件、硬化温度、被着体の耐熱性、貯蔵安定性を考慮して選択される。特に、半減期１０時間の分解温度が７０℃以上のものが好ましい。 Any organic peroxide may be used as long as it decomposes at a temperature of 100 ° C. or higher and generates radicals. The organic peroxide is generally selected in consideration of the film formation temperature, the adjustment conditions of the composition, the curing temperature, the heat resistance of the adherend, and the storage stability. In particular, those having a decomposition temperature of 70 hours or more with a half-life of 10 hours are preferred.
　前記有機過酸化物としては、樹脂の加工温度・貯蔵安定性の観点から例えば、ベンゾイルパーオキサイド系硬化剤、ｔｅｒｔ－ヘキシルパーオキシピバレート、ｔｅｒｔ－ブチルパーオキシピバレート、３，５，５－トリメチルヘキサノイルパーオキサイド、ジ－ｎ－オクタノイルパーオキサイド、ラウロイルパーオキサイド、ステアロイルパーオキサイド、１，１，３，３－テトラメチルブチルパーオキシ－２－エチルヘキサノエート、スクシニックアシドパーオキサイド、２，５－ジメチル－２，５－ジ（ｔｅｒｔ－ブチルパーオキシ）ヘキサン、２，５－ジメチル－２，５－ジ（２－エチルヘキサノイルパーオキシ）ヘキサン、１－シクロヘキシル－１－メチルエチルパーオキシ－２－エチルヘキサノエート、ｔｅｒｔ－ヘキシルパーオキシ－２－エチルヘキサノエート、４－メチルベンゾイルパーオキサイド、ｔｅｒｔ－ブチルパーオキシ－２－エチルヘキサノエート、ｍ－トルオイル＋ベンゾイルパーオキサイド、ベンゾイルパーオキサイド、１，１－ビス（ｔｅｒｔ－ブチルパーオキシ）－２－メチルシクロヘキサネート、１，１－ビス（ｔｅｒｔ－ヘキシルパーオキシ）－３，３，５－トリメチルシクロヘキサネート、１，１－ビス（ｔｅｒｔ－ヘキシルパーオキシ）シクロヘキサネート、１，１－ビス（ｔｅｒｔ－ブチルパーオキシ）－３，３，５－トリメチルシクロヘキサン、１，１－ビス（ｔｅｒｔ－ブチルパーオキシ）シクロヘキサン、１，１－ビス（ｔｅｒｔ－ヘキシルパーオキシ）－３，３，５－トリメチルシクロヘキサン、２，２－ビス（４，４－ジ－ｔｅｒｔ－ブチルパーオキシシクロヘキシル）プロパン、１，１－ビス（ｔｅｒｔ－ブチルパーオキシ）シクロドデカン、ｔｅｒｔ－ヘキシルパーオキシイソプロピルモノカーボネート、ｔｅｒｔ－ブチルパーオキシマレイックアシド、ｔｅｒｔ－ブチルパーオキシ－３，３，５－トリメチルヘキサン、ｔｅｒｔ－ブチルパーオキシラウレート、２，５－ジメチル－２，５－ジ（メチルベンゾイルパーオキシ）ヘキサン、ｔｅｒｔ－ブチルパーオキシイソプロピルモノカーボネート、ｔｅｒｔ－ブチルパーオキシ－２－エチルヘキシルモノカーボネート、ｔｅｒｔ－ヘキシルパーオキシベンゾエート、２，５－ジ－メチル－２，５－ジ（ベンゾイルパーオキシ）ヘキサン、等が挙げられる。 Examples of the organic peroxide include, from the viewpoint of processing temperature and storage stability of the resin, for example, benzoyl peroxide curing agent, tert-hexyl peroxypivalate, tert-butyl peroxypivalate, 3, 5, 5- Trimethylhexanoyl peroxide, di-n-octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, succinic acid peroxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane, 1-cyclohexyl-1-methylethyl Peroxy-2-ethylhexanoate, tert-hexylpa Oxy-2-ethylhexanoate, 4-methylbenzoyl peroxide, tert-butylperoxy-2-ethylhexanoate, m-toluoyl + benzoyl peroxide, benzoyl peroxide, 1,1-bis (tert-butyl Peroxy) -2-methylcyclohexanate, 1,1-bis (tert-hexylperoxy) -3,3,5-trimethylcyclohexanate, 1,1-bis (tert-hexylperoxy) cyclohexanate 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (tert-butylperoxy) cyclohexane, 1,1-bis (tert-hexylperoxy)- 3,3,5-trimethylcyclohexane, 2,2-bis (4,4- -Tert-butylperoxycyclohexyl) propane, 1,1-bis (tert-butylperoxy) cyclododecane, tert-hexylperoxyisopropyl monocarbonate, tert-butylperoxymaleic acid, tert-butylperoxy-3 , 3,5-trimethylhexane, tert-butylperoxylaurate, 2,5-dimethyl-2,5-di (methylbenzoylperoxy) hexane, tert-butylperoxyisopropylmonocarbonate, tert-butylperoxy- Examples include 2-ethylhexyl monocarbonate, tert-hexyl peroxybenzoate, 2,5-di-methyl-2,5-di (benzoylperoxy) hexane, and the like.
　ベンゾイルパーオキサイド系硬化剤としては、７０℃以上の温度で分解してラジカルを発生するものであればいずれも使用可能であるが、半減期１０時間の分解温度が５０℃以上のものが好ましく、調製条件、成膜温度、硬化（貼り合わせ）温度、被着体の耐熱性、貯蔵安定性を考慮して適宜選択できる。使用可能なベンゾイルパーオキサイド系硬化剤としては、例えば、ベンゾイルパーオキサイド、２，５－ジメチルヘキシル－２，５－ビスパーオキシベンゾエート、ｐ－クロロベンゾイルパーオキサイド、ｍ－トルオイルパーオキサイド、２，４－ジクロロベンゾイルパーオキサイド、ｔ－ブチルパーオキシベンゾエート等が挙げられる。ベンゾイルパーオキサイド系硬化剤は１種でも２種以上を組み合わせて使用してもよい。 As the benzoyl peroxide-based curing agent, any can be used as long as it decomposes at a temperature of 70 ° C. or higher to generate radicals, and those having a decomposition temperature of 50 hours or higher with a half-life of 10 hours are preferable, It can be appropriately selected in consideration of preparation conditions, film formation temperature, curing (bonding) temperature, heat resistance of the adherend, and storage stability. Usable benzoyl peroxide curing agents include, for example, benzoyl peroxide, 2,5-dimethylhexyl-2,5-bisperoxybenzoate, p-chlorobenzoyl peroxide, m-toluoyl peroxide, 2, Examples include 4-dichlorobenzoyl peroxide and t-butyl peroxybenzoate. The benzoyl peroxide curing agent may be used alone or in combination of two or more.
　有機過酸化物として、特に、２，５－ジメチル－２，５－ジ（ｔｅｒｔ－ブチルパーオキシ）ヘキサン、又はｔｅｒｔ－ブチルパーオキシ－２－エチルヘキシルモノカーボネートが好ましい。これにより、良好に架橋され、優れた透明性を有する太陽電池用封止膜が得られる。 As the organic peroxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane or tert-butylperoxy-2-ethylhexyl monocarbonate is particularly preferable. Thereby, the sealing film for solar cells which is bridge | crosslinked favorably and has the outstanding transparency is obtained.
　太陽電池用封止膜に使用する有機過酸化物の含有量は、封止用樹脂１００質量部に対して、好ましくは０．１～５質量部、より好ましくは０．２～３質量部であることが好ましい。有機過酸化物の含有量は、少ないと架橋硬化時において架橋速度が低下する場合があり、多くなると共重合体との相溶性が悪くなる恐れがある。 The content of the organic peroxide used in the sealing film for solar cells is preferably 0.1 to 5 parts by weight, more preferably 0.2 to 3 parts by weight with respect to 100 parts by weight of the sealing resin. Preferably there is. If the content of the organic peroxide is small, the crosslinking speed may be lowered during the crosslinking and curing, and if the content is large, the compatibility with the copolymer may be deteriorated.
　また、光重合開始剤としては、公知のどのような光重合開始剤でも使用することができるが、配合後の貯蔵安定性の良いものが望ましい。このような光重合開始剤としては、例えば、２－ヒドロキシ－２－メチル－１－フェニルプロパン－１－オン、１－ヒドロキシシクロヘキシルフェニルケトン、２－メチル－１－（４－（メチルチオ）フェニル）－２－モルホリノプロパン－１などのアセトフェノン系、ベンジルジメチルケタ－ルなどのベンゾイン系、ベンゾフェノン、４－フェニルベンゾフェノン、ヒドロキシベンゾフェノンなどのベンゾフェノン系、イソプロピルチオキサントン、２－４－ジエチルチオキサントンなどのチオキサントン系、その他特殊なものとしては、メチルフェニルグリオキシレ－トなどが使用できる。特に好ましくは、２－ヒドロキシ－２－メチル－１－フェニルプロパン－１－オン、１－ヒドロキシシクロヘキシルフェニルケトン、２－メチル－１－（４－（メチルチオ）フェニル）－２－モルホリノプロパン－１、ベンゾフェノン等が挙げられる。これら光重合開始剤は、必要に応じて、４－ジメチルアミノ安息香酸のごとき安息香酸系又は、第３級アミン系などの公知慣用の光重合促進剤の１種または２種以上を任意の割合で混合して使用することができる。また、光重合開始剤のみの１種単独または２種以上の混合で使用することができる。 As the photopolymerization initiator, any known photopolymerization initiator can be used, but a photopolymerization initiator having good storage stability after blending is desirable. Examples of such photopolymerization initiators include 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, and 2-methyl-1- (4- (methylthio) phenyl). Acetophenone series such as -2-morpholinopropane-1, benzoin series such as benzyldimethyl ketal, benzophenone series such as benzophenone, 4-phenylbenzophenone, hydroxybenzophenone, thioxanthone series such as isopropylthioxanthone, 2-4-diethylthioxanthone, As other special ones, methylphenylglyoxylate can be used. Particularly preferably, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropane-1, Examples include benzophenone. These photopolymerization initiators may contain one or more known photopolymerization accelerators such as benzoic acid-based or tertiary amine-based compounds such as 4-dimethylaminobenzoic acid, if necessary. Can be mixed and used. Moreover, it can be used individually by 1 type of only a photoinitiator, or 2 or more types of mixture.
　前記光重合開始剤の含有量は、封止用樹脂１００質量部に対して０．１～５質量部、好ましくは０．２～３質量部である。 The content of the photopolymerization initiator is 0.1 to 5 parts by mass, preferably 0.2 to 3 parts by mass with respect to 100 parts by mass of the sealing resin.
　［架橋助剤］
　本発明の太陽電池用封止膜は、さらに架橋助剤を含んでいることが好ましい。架橋助剤は、封止用樹脂のゲル分率を向上させ、太陽電池用封止膜の接着性、耐候性を向上させることができる。 [Crosslinking aid]
It is preferable that the sealing film for solar cells of the present invention further contains a crosslinking aid. The crosslinking aid can improve the gel fraction of the sealing resin and improve the adhesion and weather resistance of the solar cell sealing film.
　架橋助剤の含有量は、封止用樹脂１００質量部に対して、通常０．１～５質量部、好ましくは０．１～３質量部、特に好ましくは０．５～２．５質量部で使用される。これにより、更に架橋後の硬度が向上した封止膜が得られる。 The content of the crosslinking aid is usually 0.1 to 5 parts by weight, preferably 0.1 to 3 parts by weight, particularly preferably 0.5 to 2.5 parts by weight with respect to 100 parts by weight of the sealing resin. Used in. Thereby, the sealing film which the hardness after bridge | crosslinking improved further is obtained.
　前記架橋助剤（官能基としてラジカル重合性基を有する化合物）としては、トリアリルシアヌレート、トリアリルイソシアヌレート等の３官能の架橋助剤の他、（メタ）アクリルエステル（例、ＮＫエステル等）の単官能又は２官能の架橋助剤等を挙げることができる。なかでも、トリアリルシアヌレートおよびトリアリルイソシアヌレートが好ましく、特にトリアリルイソシアヌレートが好ましい。 Examples of the crosslinking aid (compound having a radical polymerizable group as a functional group) include trifunctional crosslinking aids such as triallyl cyanurate and triallyl isocyanurate, and (meth) acrylic esters (eg, NK ester) ) Monofunctional or bifunctional crosslinking aids. Of these, triallyl cyanurate and triallyl isocyanurate are preferable, and triallyl isocyanurate is particularly preferable.
　［接着性向上剤］
　本発明の太陽電池用封止膜においては、更に、接着向上剤を含んでいても良い。接着向上剤としては、シランカップリング剤を用いることができる。これにより、更に優れた接着力を有する太陽電池用封止膜とすることができる。前記シランカップリング剤としては、γ－クロロプロピルトリメトキシシラン、ビニルトリエトキシシラン、ビニルトリス（β－メトキシエトキシ）シラン、γ－メタクリロキシプロピルトリメトキシシラン、ビニルトリアセトキシシラン、γ－グリシドキシプロピルトリメトキシシラン、γ－グリシドキシプロピルトリエトキシシラン、β－（３，４－エポキシシクロヘキシル）エチルトリメトキシシラン、ビニルトリクロロシラン、γ－メルカプトプロピルトリメトキシシラン、γ－アミノプロピルトリエトキシシラン、Ｎ－β－（アミノエチル）－γ－アミノプロピルトリメトキシシランを挙げることができる。これらシランカップリング剤は、単独で使用しても、又は２種以上組み合わせて使用しても良い。なかでも、γ－メタクリロキシプロピルトリメトキシシランが特に好ましく挙げられる。 [Adhesion improver]
The solar cell sealing film of the present invention may further contain an adhesion improver. As the adhesion improver, a silane coupling agent can be used. Thereby, it can be set as the sealing film for solar cells which has the further outstanding adhesive force. Examples of the silane coupling agent include γ-chloropropyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, and γ-glycidoxypropyl. Trimethoxysilane, γ-glycidoxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, vinyltrichlorosilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N Mention may be made of -β- (aminoethyl) -γ-aminopropyltrimethoxysilane. These silane coupling agents may be used alone or in combination of two or more. Of these, γ-methacryloxypropyltrimethoxysilane is particularly preferred.
　本発明の太陽電池用封止膜におけるシランカップリング剤の含有量は、封止用樹脂１００質量部に対して５質量部以下、好ましくは０．１～２質量部であることが好ましい。 The content of the silane coupling agent in the solar cell sealing film of the present invention is preferably 5 parts by mass or less, preferably 0.1 to 2 parts by mass with respect to 100 parts by mass of the sealing resin.
　［その他］
　本発明の太陽電池用封止膜は、膜の種々の物性（機械的強度、透明性等の光学的特性、耐熱性、耐光性、架橋速度等）の改良あるいは調整、特に機械的強度の改良のため、必要に応じて、可塑剤、アクリロキシ基含有化合物、メタクリロキシ基含有化合物及び／又はエポキシ基含有化合物などの各種添加剤をさらに含んでいてもよい。 [Others]
The sealing film for solar cells of the present invention improves or adjusts various physical properties of the film (optical properties such as mechanical strength and transparency, heat resistance, light resistance, crosslinking speed, etc.), especially improvement of mechanical strength. Therefore, if necessary, various additives such as a plasticizer, an acryloxy group-containing compound, a methacryloxy group-containing compound and / or an epoxy group-containing compound may further be included.
　［太陽電池用封止膜］
　本発明の太陽電池用封止膜を形成するには、公知の方法に準じて行えばよい。例えば、上述した各成分を含む組成物を、通常の押出成形、又はカレンダ成形（カレンダリング）等により成形してシート状物を得る方法により製造することができる。本発明の太陽電池用封止膜の厚さは特に制限されないが、０．０５～２ｍｍ、好ましくは０．３～０．８ｍｍ、更に好ましくは０．４～０．７ｍｍである。 [Seal film for solar cell]
What is necessary is just to perform according to a well-known method in order to form the sealing film for solar cells of this invention. For example, the composition containing each of the above-described components can be produced by a method of obtaining a sheet-like material by molding by ordinary extrusion molding, calendar molding (calendering) or the like. The thickness of the solar cell sealing film of the present invention is not particularly limited, but is 0.05 to 2 mm, preferably 0.3 to 0.8 mm, and more preferably 0.4 to 0.7 mm.
　［太陽電池］
　本発明の太陽電池の構造は、本発明の太陽電池用封止膜を用いて発電素子を封止することにより製造された構造を含んでいれば特に制限されない。例えば、表面側透明保護部材と裏面側保護部材との間に、本発明の太陽電池用封止膜を介在させて架橋一体化させることにより発電素子（太陽電池用セル）を封止させた構造などが挙げられる。 [Solar cell]
The structure of the solar cell of the present invention is not particularly limited as long as it includes a structure manufactured by sealing the power generation element using the solar cell sealing film of the present invention. For example, a structure in which a power generation element (solar cell) is sealed by interposing a solar cell sealing film of the present invention between the front surface side transparent protective member and the back surface side protective member so as to be bridged and integrated. Etc.
　本発明の太陽電池は、本発明の太陽電池用封止膜が用いられているので、ＰＩＤ現象の原因となる物質が結晶性多孔質アルミノケイ酸塩粒子により捕捉され、更に２官能以上の（メタ）アクリレート化合物と併用することによる相乗効果により、ＰＩＤ現象が極めて発生しにくく、大規模太陽光発電設備に用いた場合であっても長期に亘り十分な発電能力を維持することが可能である。例えば、６００Ｖ以上の高いシステム電圧の太陽光発電設を構成する太陽電池として有用である。 Since the solar cell sealing film of the present invention is used in the solar cell of the present invention, the substance causing the PID phenomenon is captured by the crystalline porous aluminosilicate particles, and more than bifunctional (meta ) Due to the synergistic effect when used in combination with an acrylate compound, the PID phenomenon is extremely unlikely to occur, and even when used in a large-scale solar power generation facility, it is possible to maintain a sufficient power generation capacity for a long period of time. For example, it is useful as a solar cell that constitutes a solar power generation system having a high system voltage of 600 V or higher.
　なお、本発明において、太陽電池用セルの光が照射される側（受光面側）を「表面側」と称し、太陽電池用セルの受光面とは反対面側を「裏面側」と称する。 In addition, in this invention, the side (light-receiving surface side) where the light of the solar cell is irradiated is referred to as “front surface side”, and the side opposite to the light-receiving surface of the solar cell is referred to as “back surface side”.
　太陽電池において、発電素子を十分に封止するには、例えば、図１に示すように表面側透明保護部材１１、表面側封止膜１３Ａ、発電素子１４、裏面側封止膜１３Ｂ及び裏面側保護部材１２を積層し、加熱加圧など常法に従って、封止膜を架橋硬化させればよい。 In the solar cell, in order to sufficiently seal the power generation element, for example, as shown in FIG. 1, the front surface side transparent protective member 11, the front surface side sealing film 13A, the power generation element 14, the back surface side sealing film 13B, and the back surface side The protective member 12 may be laminated, and the sealing film may be cross-linked and cured according to a conventional method such as heat and pressure.
　加熱加圧するには、例えば、各部材を積層した積層体を、真空ラミネータで温度１３５～１８０℃、さらに１４０～１８０℃、脱気時間０．１～５分、プレス圧力０．１～１．５ｋｇ／ｃｍ2、プレス時間５～１５分で加熱圧着すればよい。 In order to heat and pressurize, for example, a laminated body in which each member is laminated is heated at a temperature of 135 to 180 ° C., further 140 to 180 ° C., a degassing time of 0.1 to 5 minutes, and a press pressure of 0.1 to 1. Heat pressing may be performed at 5 kg / cm 2 and a press time of 5 to 15 minutes.
　この加熱加圧時に、表面側封止膜１３Ａおよび裏面側封止膜１３Ｂに含まれる封止用樹脂を架橋させることにより、表面側封止膜１３Ａおよび裏面側封止膜１３Ｂを介して、表面側透明保護部材１１、裏面側透明部材１２、および発電素子１４を一体化させて、発電素子１４を封止することができる。発電素子１４は接続タブ１５で互いに電気的に接続される。 By crosslinking the sealing resin contained in the front side sealing film 13A and the back side sealing film 13B at the time of this heating and pressurization, the surface side sealing film 13A and the back side sealing film 13B are interposed through the surface. The power generation element 14 can be sealed by integrating the side transparent protection member 11, the back surface side transparent member 12, and the power generation element 14. The power generation elements 14 are electrically connected to each other by connection tabs 15.
　なお、本発明の太陽電池用封止膜は、図１に示したような単結晶又は多結晶のシリコン結晶系の太陽電池用セルを用いた太陽電池だけでなく、薄膜シリコン系、薄膜アモルファスシリコン系太陽電池、セレン化銅インジウム（ＣＩＳ）系太陽電池等の薄膜太陽電池の封止膜にも使用することもできる。この場合は、例えば、ガラス基板、ポリイミド基板、フッ素樹脂系透明基板等の表面側透明保護部材の表面上に化学気相蒸着法等により形成された薄膜太陽電池素子層上に、本発明の太陽電池用封止膜、裏面側保護部材を積層し、接着一体化させた構造、裏面側保護部材の表面上に形成された太陽電池素子上に、本発明の太陽電池用封止膜、表面側透明保護部材を積層し、接着一体化させた構造、又は表面側透明保護部材、表面側封止膜、薄膜太陽電池素子、裏面側封止膜、及び裏面側保護部材をこの順で積層し、接着一体化させた構造等が挙げられる。なお、本発明において、太陽電池用セルや薄膜太陽電池素子を総称して発電素子という。 The solar cell sealing film of the present invention is not limited to a solar cell using a single crystal or polycrystalline silicon crystal solar cell as shown in FIG. It can also be used for a sealing film of a thin film solar cell such as a solar cell and a copper indium selenide (CIS) solar cell. In this case, for example, the solar cell of the present invention is formed on a thin film solar cell element layer formed by a chemical vapor deposition method or the like on the surface of a surface side transparent protective member such as a glass substrate, a polyimide substrate, or a fluororesin transparent substrate. On the solar cell element formed on the surface of the back surface side protective member, the structure for laminating the battery sealing film and the back surface side protective member and adhering and integrating them, the front surface side Laminated transparent protective member, bonded and integrated structure, or front side transparent protective member, front side sealing film, thin film solar cell element, back side sealing film, and back side protective member are laminated in this order, For example, a structure that is bonded and integrated. In addition, in this invention, the cell for solar cells and a thin film solar cell element are named generically, and it is called an electric power generation element.
　表面側透明保護部材１１は、通常珪酸塩ガラスなどのガラス基板であるのがよい。ガラス基板の厚さは、０．１～１０ｍｍが一般的であり、０．３～５ｍｍが好ましい。ガラス基板は、一般に、化学的に、或いは熱的に強化させたものであってもよい。 The surface side transparent protective member 11 is usually a glass substrate such as silicate glass. The thickness of the glass substrate is generally from 0.1 to 10 mm, and preferably from 0.3 to 5 mm. The glass substrate may generally be chemically or thermally strengthened.
　裏面側保護部材１２は、ポリエチレンテレフタレート（ＰＥＴ）やポリアミドなどのプラスチックフィルムが好ましく用いられる。また、耐熱性、耐湿熱性を考慮してフッ化ポリエチレンフィルム、特にフッ化ポリエチレンフィルム／Ａｌ／フッ化ポリエチレンフィルムをこの順で積層させたフィルムでも良い。また、ガラス板でもよい。 The back side protective member 12 is preferably a plastic film such as polyethylene terephthalate (PET) or polyamide. Further, a film obtained by laminating a fluorinated polyethylene film, particularly a fluorinated polyethylene film / Al / fluorinated polyethylene film in this order in consideration of heat resistance and wet heat resistance may be used. Further, a glass plate may be used.
　なお、本発明の太陽電池用封止膜は、太陽電池（薄膜太陽電池を含む）の表面側及び／又は裏面側に用いられる封止膜に特徴を有する。したがって、表面側透明保護部材、裏面側保護部材、および太陽電池用セルなどの封止膜以外の部材については、従来公知の太陽電池と同様の構成を有していればよく、特に制限されない。 In addition, the sealing film for solar cells of this invention has the characteristics in the sealing film used for the surface side and / or back surface side of a solar cell (a thin film solar cell is included). Therefore, the members other than the sealing film such as the front surface side transparent protective member, the back surface side protective member, and the solar battery cell are not particularly limited as long as they have the same configuration as a conventionally known solar battery.
　以下、本発明を実施例により詳細に説明する。 Hereinafter, the present invention will be described in detail with reference to examples.
　１．太陽電池用封止膜の作製
　下記表に示す配合で各材料をロールミルに供給し、７０℃において混練して太陽電池用封止膜組成物を調製した。この太陽電池用封止膜組成物を、７０℃においてカレンダ成形し、放冷後、太陽電池用封止膜（厚さ０．４６ｍｍ）を作製した。 1. Production of Solar Cell Sealing Film Each material was supplied to a roll mill with the formulation shown in the following table, and kneaded at 70 ° C. to prepare a solar cell sealing film composition. This solar cell sealing film composition was calendered at 70 ° C., allowed to cool, and then a solar cell sealing film (thickness 0.46 mm) was produced.
　２．評価
　（１）ＰＩＤ試験（出力保持率）
　上記で得られた太陽電池用封止膜を表面側封止膜、及び裏面側封止膜として用い、表面側透明保護部材（ガラス板）、裏面側保護部材（ＰＥＴフィルム）間に太陽電池用セルを挟持した状態で加熱加圧し、太陽電池用セルを４個接続した太陽電池ミニモジュールを作製した。ＰＩＤ現象を発生させるモデル試験として、水槽内に、作製した太陽電池ミニモジュールを受光面側が下側になるように浸漬させ、温度８５℃、相対湿度８５％にて、短絡させたモジュールの出力端子を－極に接続し、＋極は水槽内に配置した銅板に接続し、１５００Ｖの電圧を４８時間印加した。 2. Evaluation (1) PID test (output retention rate)
The solar cell sealing film obtained above is used as a front-side sealing film and a back-side sealing film, and for solar cells between the front-side transparent protective member (glass plate) and the back-side protective member (PET film). A solar cell mini-module in which four cells for solar cells were connected was manufactured by heating and pressing with the cells sandwiched. As a model test for generating a PID phenomenon, the output terminal of a module short-circuited at a temperature of 85 ° C. and a relative humidity of 85% by immersing the produced solar cell mini-module in a water tank so that the light receiving surface side is at the bottom Was connected to a negative electrode, and the positive electrode was connected to a copper plate disposed in a water tank, and a voltage of 1500 V was applied for 48 hours.
　上記試験前後で、各太陽電池ミニモジュールの最大出力（Ｐｍａｘ）を測定し、出力保持率（（試験後Ｐｍａｘ／試験前Ｐｍａｘ）×１００（％））を算出した。 Before and after the test, the maximum output (P max ) of each solar cell mini-module was measured, and the output retention rate ((post test P max / pre test P max ) × 100 (%)) was calculated.
　（２）耐発泡性能
　ガラス／上記太陽電池用封止膜／上記太陽電池用封止膜／ＰＥＴフィルム／アルミ製バックシートの順で積層した得た積層体を９０℃にて真空ラミネータを使用して仮圧着した。仮圧着した積層体を１５５℃の雰囲気下に放置して加熱することにより、架橋反応を進行させた。加熱開始後から発泡が発生するまでの時間（ｍｉｎ）を計測した。 (2) Antifoaming performance Glass / the solar cell sealing film / the solar cell sealing film / PET film / aluminum back sheet was laminated in this order using a vacuum laminator at 90 ° C. And temporarily crimped. The prebonded laminate was allowed to heat in an atmosphere at 155 ° C. to advance the crosslinking reaction. The time (min) from the start of heating until foaming occurred was measured.
　（３）ＨＡＺＥ値（透明性）
　上記太陽電池用封止膜を２枚の白板ガラス（厚さ３．２ｍｍ）で挟み、得られた積層体を真空ラミネータを用いて９０℃において真空時間２分、プレス時間８分で圧着した後、１５５℃のオーブン中で３０分間加熱して架橋硬化させることにより、サンプルを作製した。このサンプルについて、ＪＩＳ　Ｋ　７１０５（２０００年）に従って、ヘイズメーター（日本電色工業株式会社製 ＮＤＨ ２０００型）を用いてヘイズ値（％）を測定した。 (3) HAZE value (transparency)
After sandwiching the solar cell sealing film between two pieces of white plate glass (thickness: 3.2 mm), the resulting laminate is pressure-bonded at 90 ° C. with a vacuum laminator at a vacuum time of 2 minutes and a press time of 8 minutes. Samples were prepared by heating in an oven at 155 ° C. for 30 minutes to crosslink and cure. About this sample, according to JISK7105 (2000), haze value (%) was measured using the haze meter (Nippon Denshoku Industries Co., Ltd. NDH 2000 type | mold).
　（４）加工性
　加工性は表１に示した配合でロールミル混練を行い、ロールへの貼り付き性や剥離性を確認することにより評価をした。○は貼り付き性及び剥離性共に良好だったものであり、△は若干の不良が認められたものである。 (4) Workability Workability was evaluated by performing roll mill kneading with the formulation shown in Table 1 and confirming stickability to the roll and peelability. ○ indicates that both sticking property and peelability are good, and Δ indicates that some defects are observed.
　結果を下記表に示す。 The results are shown in the table below.
Figure JPOXMLDOC01-appb-T000004
 備考）
ＥＶＡ：酢酸ビニル含有率２６質量％
架橋剤：ｔ－ブチルパーオキシ－２－エチルヘキシルモノカーボネート
架橋助剤：トリアリルイソシアヌレート
光安定剤：セバシン酸ビス（２，２，６，６－テトラメチル－４－ピペリジル）
紫外線吸収剤：２－ヒドロキシ－４－ｎ－オクトキシベンゾフェノン
接着性向上剤：γ－メタクリロキシプロピルトリメトキシシラン
結晶性多孔質アルミノケイ酸塩粒子：ゼオライト粒子（陽イオン：カリウムイオン及びナトリウムイオン。カリウムイオンとナトリウムイオンの合計量に対するカリウムイオンの割合（ｍｏｌ％）をＫ＋イオン交換率として示している。シリカ／アルミナ比は各実施例で異なる）
（メタ）アクリレート化合物１：共栄社化学製ライトエステル９ＥＧ、式（Ｉ）のＲがメチル基、ｍが９のもの
Figure JPOXMLDOC01-appb-T000004
 Remarks)
EVA: vinyl acetate content 26 mass%
Cross-linking agent: t-butylperoxy-2-ethylhexyl monocarbonate Cross-linking aid: triallyl isocyanurate light stabilizer: bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate
UV absorber: 2-hydroxy-4-n-octoxybenzophenone adhesion improver: γ-methacryloxypropyltrimethoxysilane crystalline porous aluminosilicate particle: zeolite particle (cation: potassium ion and sodium ion. Potassium The ratio of potassium ions to the total amount of ions and sodium ions (mol%) is shown as K + ion exchange rate (silica / alumina ratio is different in each example)
(Meth) acrylate compound 1: light ester 9EG made by Kyoeisha Chemical Co., R in formula (I) is methyl group, m is 9
Figure JPOXMLDOC01-appb-T000005
 備考）表１に同じ。
Figure JPOXMLDOC01-appb-T000005
 Remarks) Same as Table 1.
Figure JPOXMLDOC01-appb-T000006
 備考）下記材料の他は表１と同様である。
（メタ）アクリレート化合物２（ＥＯ変性トリメチロールプロパントリアクリレート、
共栄社化学社製ライトアクリレートＴＭＰ－６ＥＯ－３Ａ）
（メタ）アクリレート化合物３（ペンタエリスリトールテトラアクリレート、共栄社化学社製ライトアクリレートＰＥ－４Ａ）
メタ）アクリレート化合物４（ジペンタエリスリトールヘキサアクリレート、共栄社化学社製ライトアクリレートＤＰＥ－６Ａ）
Figure JPOXMLDOC01-appb-T000006
 Remarks) Other than the following materials, the same as in Table 1.
(Meth) acrylate compound 2 (EO-modified trimethylolpropane triacrylate,
Kyoeisha Chemical Co., Ltd. light acrylate TMP-6EO-3A)
(Meth) acrylate compound 3 (pentaerythritol tetraacrylate, light acrylate PE-4A manufactured by Kyoeisha Chemical Co., Ltd.)
(Meth) acrylate compound 4 (dipentaerythritol hexaacrylate, Kyoeisha Chemical Co., Ltd. light acrylate DPE-6A)
　１１　表面側透明保護部材
　１２　裏面側保護部材
　１３Ａ　表面側封止膜
　１３Ｂ　裏面側封止膜
　１４　発電素子
　１５　接続タブ DESCRIPTION OF SYMBOLS 11 Surface side transparent protective member 12 Back surface side protective member 13A Surface side sealing film 13B Back surface side sealing film 14 Power generation element 15 Connection tab

Claims (12)

  1. 　封止用樹脂、結晶性多孔質アルミノケイ酸塩粒子、及び２官能以上の（メタ）アクリレート化合物を含む太陽電池用封止膜。 Sealing film for solar cell containing sealing resin, crystalline porous aluminosilicate particles, and bifunctional or higher functional (meth) acrylate compound.
  2. 　前記（メタ）アクリレート化合物が－（ＣｎＨ２ｎＯ）－鎖（但し、ｎは２～５の整数である。）を有する、請求項１に記載の太陽電池用封止膜。 2. The solar cell sealing film according to claim 1, wherein the (meth) acrylate compound has a — (C n H 2n O) — chain (where n is an integer of 2 to 5).
  3. 　前記（メタ）アクリレート化合物は下記式（Ｉ）
    Figure JPOXMLDOC01-appb-C000001
     （但し、Ｒはそれぞれ独立して水素原子又はメチル基であり、mは２～２０の整数である。）
    で表されるジ（メタ）アクリレート化合物である、請求項１又は２に記載の太陽電池用封止膜。     The (meth) acrylate compound has the following formula (I)
    Figure JPOXMLDOC01-appb-C000001
     (However, each R is independently a hydrogen atom or a methyl group, and m is an integer of 2 to 20.)
    The solar cell sealing film of Claim 1 or 2 which is a di (meth) acrylate compound represented by these.
  4. 　前記結晶性多孔質アルミノケイ酸塩粒子の含有量が、前記封止用樹脂１００質量部に対して０．０５～１質量部であり、
    　前記（メタ）アクリレート化合物の含有量が、前記封止用樹脂１００質量部に対して０．０５～１質量部である、請求項１～３の何れか１項に記載の太陽電池用封止膜。     The content of the crystalline porous aluminosilicate particles is 0.05 to 1 part by mass with respect to 100 parts by mass of the sealing resin,
    The encapsulating solar cell according to any one of claims 1 to 3, wherein a content of the (meth) acrylate compound is 0.05 to 1 part by mass with respect to 100 parts by mass of the encapsulating resin. film.
  5. 　前記結晶性多孔質アルミノケイ酸塩粒子の含有量が、前記封止用樹脂１００質量部に対して０．１～０．３質量部であり、
    　前記（メタ）アクリレート化合物の含有量が、前記封止用樹脂１００質量部に対して０．２～０．４質量部である、請求項１～４の何れか１項に記載の太陽電池用封止膜。     The content of the crystalline porous aluminosilicate particles is 0.1 to 0.3 parts by mass with respect to 100 parts by mass of the sealing resin,
    The solar cell according to any one of claims 1 to 4, wherein a content of the (meth) acrylate compound is 0.2 to 0.4 parts by mass with respect to 100 parts by mass of the sealing resin. Sealing film.
  6. 　前記結晶性多孔質アルミノケイ酸塩粒子のシリカ／アルミナ比が１～５である、請求項１～５の何れか１項に記載の太陽電池用封止膜。 The solar cell sealing film according to any one of claims 1 to 5, wherein the crystalline porous aluminosilicate particles have a silica / alumina ratio of 1 to 5.
  7. 　前記（メタ）アクリレート化合物に対する前記結晶性多孔質アルミノケイ酸塩粒子の質量比が０．０５～２０である、請求項１～６の何れか１項に記載の太陽電池用封止膜。 The solar cell sealing film according to any one of claims 1 to 6, wherein a mass ratio of the crystalline porous aluminosilicate particles to the (meth) acrylate compound is 0.05 to 20.
  8. 　前記結晶性多孔質アルミノケイ酸塩が陽イオンを含有し、
    　前記陽イオンの少なくとも一部は、ナトリウムイオンを除くアルカリ金属イオン、アルカリ土類金属イオン及びマグネシウムイオンからなる群から選択される少なくとも１種である、請求項１～７のいずれか１項に記載の太陽電池用封止膜。     The crystalline porous aluminosilicate contains a cation,
    The at least part of the cations is at least one selected from the group consisting of alkali metal ions excluding sodium ions, alkaline earth metal ions, and magnesium ions. Solar cell sealing film.
  9. 　前記陽イオンの少なくとも一部は、カリウムイオンである、請求項８に記載の太陽電池用封止膜。 The solar cell sealing film according to claim 8, wherein at least a part of the cations are potassium ions.
  10. 　陽イオンとして、ナトリウムイオンを更に含む、請求項８又は９に記載の太陽電池用封止膜。 The solar cell sealing film according to claim 8 or 9, further comprising sodium ions as cations.
  11. 　前記カリウムイオンとナトリウムイオンの合計量に対するカリウムイオンの割合が３０～６０ｍｏｌ％である、請求項１０に記載の太陽電池用封止膜。 The solar cell sealing film according to claim 10, wherein the ratio of potassium ions to the total amount of potassium ions and sodium ions is 30 to 60 mol%.
  12. 　請求項１～１１の何れか１項に記載の太陽電池用封止膜により発電素子が封止されている太陽電池。 A solar cell in which a power generation element is sealed with the solar cell sealing film according to any one of claims 1 to 11.
PCT/JP2015/084753 2014-12-26 2015-12-11 Sealing film for solar cells and solar cell using same WO2016104175A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2014265930A JP2018029092A (en) 2014-12-26 2014-12-26 Solar cell sealing film and solar cell using the film
JP2014-265930 2014-12-26

Publications (1)

Publication Number Publication Date
WO2016104175A1 true WO2016104175A1 (en) 2016-06-30

Family

ID=56150205

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2015/084753 WO2016104175A1 (en) 2014-12-26 2015-12-11 Sealing film for solar cells and solar cell using same

Country Status (2)

Country Link
JP (1) JP2018029092A (en)
WO (1) WO2016104175A1 (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013118504A1 (en) * 2012-02-10 2013-08-15 三井化学株式会社 Solar cell sealing material and solar cell module
JP2014011270A (en) * 2012-06-28 2014-01-20 Kyocera Corp Solar cell module and photovoltaic power generation system using the same
JP2014036076A (en) * 2012-08-08 2014-02-24 Toyo Ink Sc Holdings Co Ltd Resin composition for solar battery sealing material

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013118504A1 (en) * 2012-02-10 2013-08-15 三井化学株式会社 Solar cell sealing material and solar cell module
JP2014011270A (en) * 2012-06-28 2014-01-20 Kyocera Corp Solar cell module and photovoltaic power generation system using the same
JP2014036076A (en) * 2012-08-08 2014-02-24 Toyo Ink Sc Holdings Co Ltd Resin composition for solar battery sealing material

Also Published As

Publication number Publication date
JP2018029092A (en) 2018-02-22

Similar Documents

Publication Publication Date Title
EP2808906B1 (en) Sealing film for solar cells, and solar cell using same
US9293616B2 (en) Solar cell sealing film and solar cell using the same
EP2685508B1 (en) Sealing film for solar cells and solar cell using same
WO2014017282A1 (en) Sealing film for solar cells, solar cell module, and method for selecting sealing film for solar cells
JP5785794B2 (en) Solar cell sealing film and solar cell using the same
US20150303339A1 (en) Pair of sealing films for solar cell and method for producing solar cell module using same
JP5369020B2 (en) Ethylene-vinyl acetate copolymer sheet, solar cell using the same, and laminated glass
WO2016194606A1 (en) Sealing film for solar cells, and solar cell module
EP2770541B1 (en) Solar cell sealing film and solar cell using same
JP2012241169A (en) Ethylene-polar monomer copolymer sheet, and intermediate film for glass laminate, glass laminate, solar cell sealing film and solar cell using the same
WO2014133074A1 (en) Solar cell module manufacturing method and solar cell module
JP2014027034A (en) Sealing film for solar cell, and selection method therefor
WO2016104175A1 (en) Sealing film for solar cells and solar cell using same
JP5909101B2 (en) Composition for forming sealing film for solar cell
JP2017228673A (en) Sealant for solar battery, and solar battery module using the same
JP2016213401A (en) Composition for manufacturing sealant for solar batteries
JP5869211B2 (en) Solar cell sealing film and solar cell using the same
WO2016152719A1 (en) Sealing material for solar cells and solar cell module using same
JP2017222752A (en) Composition for producing sealing material for solar battery, and sealing material for solar battery
JP2017103410A (en) Method for manufacturing sealant for solar battery, and composition for manufacturing sealant for solar battery
JP2014197683A (en) Solar cell encapsulation film and solar cell using the same
WO2016072471A1 (en) Sealing film for solar cells, and solar cell
JP2017222753A (en) Composition for producing sealing material for solar battery, and sealing material for solar battery
JP2017101196A (en) Composition for manufacturing encapsulation material for solar cell and encapsulation material for solar cell

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 15872744

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 15872744

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP