JP2013145801A - Protection film for solar battery module, and solar battery module using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a protection film for a solar battery module having peelability and easy to rework, and a solar battery module using the same.SOLUTION: A protection film 11 for a solar battery module comprises: a base material layer 2 made of a synthetic resin; and a thermal fusion layer 3 laminated on one face of the base material layer 2. The thermal fusion layer 3 includes a polymer having a siloxane bond. In the protection film 11 for a solar battery module, the polymer having a siloxane bond may be siloxane-modified polycarbonate. In the protection film for a solar battery module, the thermal fusion layer may further include polycarbonate without a siloxane bond. It is preferable that the mass ratio of the polycarbonate without a siloxane bond to the siloxane-modified polycarbonate is between 10 and 1000 mass% inclusive.

Description

  The present invention relates to a protective film suitably used for a solar cell module and a solar cell module using the protective film.

  In recent years, solar power generation as a clean energy source has attracted attention due to increasing awareness of environmental problems such as global warming, and solar cells having various forms have been developed. This solar battery is generally composed of a plurality of solar battery modules that are packaged by a plurality of solar battery cells wired in series or in parallel.

  The solar cell module is required to have sufficient durability and weather resistance that can be used outdoors for a long period of time. As a specific structure of a general solar cell module 31, as shown in FIG. 4, a transparent substrate 32 made of glass or the like, a surface side filler layer 33 made of a thermoplastic resin, and a photovoltaic element The solar battery cell 34, the back side filler layer 35 made of a thermoplastic resin, and a solar cell module backsheet 40 (hereinafter simply referred to as a backsheet) are laminated in this order and integrally formed. (For example, refer to JP 2009-302361 A). The back-side filler layer 35 is formed of, for example, ethylene-vinyl acetate copolymer (EVA), and the back sheet 40 has a heat-melting layer formed of a thermoplastic polyethylene-based resin. A wearing layer (not shown) is provided. And in the said integral molding, generally the laminated body laminated | stacked as mentioned above is adhere | attached by the heating lamination method. For this reason, the said back surface side filler layer 35 and the back sheet | seat 40 (the heat sealing | fusion layer) are adhere | attached and fixed by heat sealing | fusion.

  On the other hand, the solar cell module after installation may have insufficient power generation efficiency because some of the solar cells are damaged. In such a case, so-called rework work such as replacement of damaged solar cells is performed. In this rework operation, the solar cell module back sheet is generally peeled off from the back surface of the solar cell module, and defective solar cells or the like are replaced from the back surface side.

  In this reworking operation, the operator holds a part of the back sheet and pulls the back sheet toward the back side of the solar cell module, thereby peeling the back sheet.

  However, since the heat-seal layer on the front surface is firmly bonded to the back-side filler layer made of EVA by heat-seal, it is difficult for the back sheet to be peeled off manually by the operator. In order to facilitate this peeling operation, it is conceivable to perform the above-mentioned peeling operation while heating the back sheet. However, in the heating that can be gripped by the operator, the back-side filler layer and the heat fusion layer The adhesive force is large, and the labor required for the peeling work is great.

JP 2009-302361 A

  The present invention has been made in view of such circumstances, and is excellent in releasability and the like, and can easily perform rework work such as replacement of damaged solar cells even after the solar cell module is integrally formed. It aims at providing the protective film for solar cell modules which can be performed rapidly, and a solar cell module using the same.

The invention made to solve the above problems is
A base layer made of synthetic resin;
A thermal fusion layer laminated on one surface side of the base material layer,
The said heat sealing | fusion layer is a protective film for solar cell modules containing the polymer which has a siloxane bond.

  The said protective film for solar cell modules is arrange | positioned by the surface side or back surface side of a solar cell module, when a heat sealing | fusion layer is heat-seal | fused. As a result, the components of the solar cell module are protected by the solar cell module protective film. And since the heat sealing | fusion layer of the said protective film for solar cell modules contains the polymer which has a siloxane bond, it has favorable peelability. Therefore, the solar cell module using the protective film for solar cell module can easily peel off the protective film for solar cell module when the solar cell is damaged or the like. Can be exchanged. That is, the said protective film for solar cell modules can improve the efficiency of the rework operation | work of a solar cell module.

  In the protective film for a solar cell module, the polymer having the siloxane bond is preferably a siloxane-modified polycarbonate. When the said heat sealing | fusion layer contains a siloxane modified polycarbonate, the impact resistance of the said solar cell module protective film, heat resistance, and a self-extinguishing property can be improved more.

  In the solar cell module protective film, the heat-sealing layer may further contain a polycarbonate having no siloxane bond. As described above, the heat-sealing layer further contains a polycarbonate having no siloxane bond, and by adjusting the content of the polycarbonate, a desired material can be used depending on the place of use, the material to be heat-sealed, or the like. Peel strength can be obtained.

  The said solar cell module protective film is good in the mass ratio of the polycarbonate which does not have a siloxane bond with respect to a siloxane modified polycarbonate being 10 mass% or more and 1000 mass% or less. By setting the mass ratio of the polycarbonate to the siloxane-modified polycarbonate within the above range, it is possible to suppress occurrence of a phenomenon (bleed out) in which a component of the heat-sealing layer exudes while having sufficient peelability.

  The solar cell module protective film has a 180 ° peel strength of 20 N / 10 mm or more and 200 N / 10 mm or less at a tensile speed of 300 mm / min with respect to a glass plate in an environment of 23 ° C. × 50% RH of the heat-sealing layer. Good. By setting the peel strength of the protective film for a solar cell module within the above range, the peel work can be facilitated while having sufficient adhesiveness, and the work efficiency during rework can be improved.

  In the solar cell module protective film, a pigment may be dispersed and contained in the heat-sealing layer. As described above, by dispersing and containing the pigment in the heat sealing layer, the heat resistance, thermal dimensional stability, weather resistance, strength, anti-aging, etc. of the protective film for solar cell module are improved. Can do.

  The said protective film for solar cell modules is good to further provide a hydrolysis-resistant layer in the other surface side of the said base material layer. Thus, by providing a hydrolysis-resistant layer on the other surface side of the base material layer, the durability, weather resistance, etc. of the protective film for solar cell module can be dramatically improved. Moreover, the solar cell module using the said protective film for solar cell modules can be used suitably for a long time use outdoors by improving durability, a weather resistance, etc.

  The solar cell module protective film may further include a gas barrier layer on the other surface side of the base material layer. Thus, the gas barrier property with respect to oxygen, water vapor | steam, etc. can be provided to the said protective film for solar cell modules by providing a gas barrier layer further on the other surface side of a base material layer. Moreover, the solar cell module using the protective film for the solar cell module is improved in durability, weather resistance, and the like by being provided with a gas barrier property against oxygen, water vapor and the like, and is suitable for long-term use outdoors. Can be used.

  It is preferable that the said protective film for solar cell modules employ | adopt the structure adhere | attached by the said heat-fusion layer on the back surface side of the photovoltaic cell of a solar cell module. Thereby, the said protective film for solar cell modules can be used as a solar cell module backsheet. That is, the solar cell module to which the solar cell module protective film is bonded is protected by the solar cell module protective film. And when this solar cell module breaks a photovoltaic cell, etc., since the said protective film for solar cell modules can be easily peeled from the back surface side, parts replacement work etc. from this peeled back surface side, etc. Can be performed easily.

Another invention made to solve the above problems is as follows:
A solar cell module in which a light-transmitting substrate, a filler layer, a solar battery cell as a photovoltaic element, a filler layer, and the protective film for a solar cell module are laminated in this order.

  The solar cell module has good releasability because the heat-sealing layer of the solar cell module protective film contains a polymer having a siloxane bond. Therefore, when the solar cell module is damaged, the solar cell module can easily peel the protective film for the solar cell module, and can perform a part replacement operation or the like from the peeled side. That is, the solar cell module can improve the efficiency of rework work. Moreover, the said solar cell module has the protective film for solar cell modules adhere | attached on the back surface side of the solar cell module by heat sealing | fusion. As a result, the solar cell module components are protected by the solar cell module protective film.

  Here, the “back surface” means a surface opposite to the light receiving side of the solar cell module. The “siloxane bond” is a bond of silicon and oxygen represented by the chemical formula “Si—O—Si”, and “siloxane-modified polycarbonate” has a siloxane bond in the main chain, side chain, or terminal of the polycarbonate. Means things.

  As described above, the solar cell module protective film of the present invention has an excellent peelability in the heat-sealable layer, and therefore, when the solar cell is damaged, etc. after being integrally formed as a solar cell module. Even if it exists, the said protective film for solar cell modules can be peeled easily, and the efficiency of a rework operation | work can be improved.

It is typical sectional drawing which shows the protective film for solar cell modules which concerns on one Embodiment of this invention. It is typical sectional drawing which shows the protective film for solar cell modules which concerns on the form different from the protective film for solar cell modules of FIG. (A) is typical sectional drawing which shows the solar cell module using the protective film for solar cell modules of FIG. 1, (b) is a schematic diagram which shows the solar cell module using the protective film for solar cell modules of FIG. FIG. It is typical sectional drawing which shows the conventional common solar cell module.

  Hereinafter, embodiments of the protective film for a solar cell module according to the present invention will be described in detail with reference to the drawings as appropriate. First, as a first embodiment of the present invention, a back sheet for a solar cell module shown in FIG. 1 and FIG.

[First embodiment]
The protective film 1 for solar cell modules of 1st embodiment is provided with the base material layer 2 and the heat-fusion layer 3 which were formed in the sheet form.

<Base material layer>
The base material layer 2 is formed of a sheet made of synthetic resin. The synthetic resin used for the base material layer 2 is not particularly limited. For example, polyethylene resin, polypropylene resin, cyclic polyolefin resin, polystyrene resin, acrylonitrile-styrene copolymer (AS resin), acrylonitrile. -Butadiene-styrene copolymer (ABS resin), polyvinyl chloride resin, fluorine resin, poly (meth) acrylic resin, polycarbonate resin, polyester resin, polyamide resin, polyimide resin, polyamideimide resin And polyaryl phthalate resins, silicone resins, polysulfone resins, polyphenylene sulfide resins, polyether sulfone resins, polyurethane resins, acetal resins, and cellulose resins. Among the above resins, polyester resins, fluorine resins, and cyclic polyolefin resins having high heat resistance, strength, weather resistance, durability, gas barrier properties against water vapor and the like are preferable.

  Examples of the polyester resin include polyethylene terephthalate and polyethylene naphthalate. Among these polyester-based resins, polyethylene terephthalate is particularly preferable because it has a good balance between various functions such as heat resistance and weather resistance, and price.

  Examples of the fluororesin include polytetrafluoroethylene (PTFE), perfluoroalkoxy resin (PFA) made of a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether, and a copolymer of tetrafluoroethylene and hexafluoropropylene (FEP). Copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether and hexafluoropropylene (EPE), copolymer of tetrafluoroethylene and ethylene or propylene (ETFE), polychlorotrifluoroethylene resin (PCTFE), ethylene and chlorotrifluoroethylene Copolymer (ECTFE), vinylidene fluoride resin (PVDF), vinyl fluoride resin (PVF), and the like. Among these fluororesins, polyvinyl fluoride resin (PVF) and a copolymer of tetrafluoroethylene and ethylene or propylene (ETFE) which are excellent in strength, heat resistance, weather resistance and the like are particularly preferable.

  As the cyclic polyolefin resin, for example, a) cyclic dienes such as cyclopentadiene (and derivatives thereof), dicyclopentadiene (and derivatives thereof), cyclohexadiene (and derivatives thereof), norbornadiene (and derivatives thereof) are polymerized. And b) a copolymer obtained by copolymerizing the cyclic diene with one or more olefinic monomers such as ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, and isoprene. . Among these cyclic polyolefin resins, cyclopentadiene (and derivatives thereof), dicyclopentadiene (and derivatives thereof) or norbornadiene (and derivatives thereof) such as polymers having excellent strength, heat resistance, and weather resistance are particularly preferred. preferable.

  In addition, as a forming material of the base material layer 2, the said synthetic resin can be used 1 type or in mixture of 2 or more types.

  In addition, various additives and the like can be mixed in the forming material of the base material layer 2 for the purpose of improving and modifying processability, heat resistance, weather resistance, mechanical properties, dimensional stability, and the like. . Examples of the additive include a lubricant, a crosslinking agent, an antioxidant, a light stabilizer, a filler, a reinforcing fiber, a reinforcing agent, a flame retardant, a flame retardant, a foaming agent, and an antifungal agent.

  The base material layer 2 preferably contains an ultraviolet absorber. When the base material layer 2 contains an ultraviolet absorber, the weather resistance and durability of the solar cell module protective film 1 can be further improved. The ultraviolet absorber is not particularly limited as long as it is a compound that absorbs ultraviolet rays and can be efficiently converted into thermal energy and is stable to light, and a known one can be used. it can. Among them, salicylic acid-based UV absorbers, benzophenone-based UV absorbers, benzotriazole-based UV absorbers, and cyano have a high UV-absorbing function, good compatibility with the above-mentioned base polymer, and exist stably in the base polymer. An acrylate ultraviolet absorber is preferable, and one or more selected from these groups may be used. In addition, as the ultraviolet absorber, a polymer having an ultraviolet absorbing group in a molecular chain (for example, “Udable UV” series of Nippon Shokubai Co., Ltd.) is also preferably used. By using a polymer having an ultraviolet absorbing group in such a molecular chain, compatibility with the polymer constituting the base material layer 2 is increased, and deterioration of the ultraviolet absorbing function due to bleeding out of the ultraviolet absorber component is effectively prevented. be able to.

  As a minimum of content of the said ultraviolet absorber, 0.1 mass% is preferable, 1 mass% is more preferable, and 3 mass% is further more preferable. On the other hand, as an upper limit of content of a ultraviolet absorber, 10 mass% is preferable, 8 mass% is more preferable, and 5 mass% is further more preferable. When the blending amount of the UV absorber is less than the above lower limit, the UV absorbing function of the solar cell module protective film 1 may not be effectively achieved, while the blending amount of the UV absorber exceeds the above upper limit. If the matrix polymer is adversely affected, the strength and durability of the base material layer 2 may be reduced.

  The base material layer 2 may contain an antistatic agent. Thus, the antistatic effect is provided to the said protective film 1 for solar cell modules by containing an antistatic agent. As a result, reduction in power generation efficiency and dust suction due to static electricity can be suppressed, and foreign matters can be effectively prevented from entering between films during rework. Further, when the antistatic agent is coated on the film surface, the surface becomes sticky or contaminated. However, the inclusion of the antistatic agent in the base material layer 2 in this way reduces the adverse effects. Such an antistatic agent is not particularly limited, for example, anionic antistatic agents such as alkyl sulfates and alkyl phosphates, cation antistatic agents such as quaternary ammonium salts and imidazoline compounds, Nonionic antistatic agents such as polyethylene glycol, polyoxyethylene sorbitan monostearate, ethanolamides, and high molecular antistatic agents such as polyacrylic acid are used. Among them, a cationic antistatic agent having a relatively large antistatic effect is preferable, and an antistatic effect can be obtained by adding a small amount.

  The base material layer 2 may contain a pigment in a dispersed manner. Thus, by dispersing and containing the pigment in the base material layer 2, various properties such as heat resistance, weather resistance, durability, thermal dimensional stability, strength, etc. of the base material layer 2 and thus the protective film 1 for the solar cell module. The characteristics can be improved. Moreover, the design property of a solar cell module can be improved by disperse | distributing black pigment etc. in the base material layer 2, and coloring the base material layer 2 in various colors.

  Of the above pigments, white pigments are preferred in that light diffusibility can be imparted. The white pigment is not particularly limited, and for example, calcium carbonate, titanium oxide, zinc oxide, lead carbonate, barium sulfate and the like can be used. Among these, calcium carbonate is preferable because it is excellent in dispersibility in the resin material forming the synthetic resin layer and has a relatively large effect of improving the durability, heat resistance, strength, and the like of the synthetic resin layer. This calcium carbonate has crystal types such as calcite, aragonite, and vaterite, and any crystal type can be used. This calcium carbonate may be surface-treated with stearic acid, sodium dodecyl benzene sulfonate, silane coupling agent, titanium coupling agent, etc., and impurities such as magnesium oxide, aluminum oxide, silicon dioxide, titanium dioxide, etc. About 10% or less may be contained. Other pigments include black pigments such as carbon black, blue pigments such as ultramarine and bitumen, red pigments such as red bean (iron oxide red), cadmium red, and molybdenum orange, and metal powder pigments that give metallic luster. These contribute to the improvement of the designability of the solar cell module.

  The lower limit of the average particle diameter of the pigment is preferably 100 nm, and more preferably 300 nm. On the other hand, as an upper limit, 30 micrometers is preferable and 3 micrometers is more preferable. This is because when the average particle diameter of the pigment is less than the above lower limit, uniform dispersion in the base material layer 2 may be difficult due to aggregation or the like. This is because the effect of improving various properties such as property may be reduced.

  The lower limit of the pigment content is preferably 8% by mass, more preferably 15% by mass. On the other hand, as an upper limit, 30 mass% is preferable and 20 mass% is more preferable. This is because when the pigment content is less than the above lower limit, the effect of improving the durability, heat resistance, strength, etc. of the base material layer 2 may be reduced. This is because the dispersibility of the pigment in this case is lowered, and the strength of the base material layer 2 may be lowered.

  The forming method of the base material layer 2 is not particularly limited, and a known method such as an extrusion method such as a T-die method or an inflation method, a cast forming method, or a cutting method is employed.

  As a minimum of the thickness (average thickness) of the above-mentioned base material layer 2, 25 micrometers is preferred and 50 micrometers is more preferred. On the other hand, the upper limit of the thickness of the base material layer 2 is preferably 250 μm, and more preferably 188 μm. When the thickness of the base material layer 2 is less than the above lower limit, there is a risk that inconveniences such as curling easily occur during handling of the heat-fusible layer 3 to be described later and handling become difficult. . On the other hand, when the thickness of the base material layer 2 exceeds the above upper limit, it is against the request for thinning and lightening of the solar cell module.

<Heat-fusion layer>
The heat-sealing layer 3 is a resin layer that melts when the solar cell module protective film 1 is heat-sealed to the back surface of the solar cell module, and is heat-sealed to the surface of the base material layer 2. The solar cell module protective film 1 is characterized in that the heat-sealing layer 3 contains a polymer having a siloxane bond.

  Examples of the polymer having a siloxane bond include those in which at least one of a main chain, a side chain, and a terminal of a polymer serving as a substrate is modified with siloxane. The base polymer is not particularly limited, and for example, polyethylene resin, polypropylene resin, cyclic polyolefin resin, polystyrene resin, acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer ( ABS resin), polyvinyl chloride resin, fluorine resin, poly (meth) acrylic resin, polycarbonate resin, polyester resin, polyamide resin, polyimide resin, polyamideimide resin, polyarylphthalate resin, silicone Resin, polysulfone resin, polyphenylene sulfide resin, polyethersulfone resin, polyurethane resin, acetal resin, cellulose resin and the like. Among them, siloxane-modified polycarbonate is preferable from the viewpoint of transparency, impact resistance, weather resistance, releasability, etc., and is polydimethyl from the viewpoint of high flexibility, little deterioration due to ultraviolet rays, heat resistance, flame retardancy, and the like. Siloxane (PDMS) modified polycarbonate is more preferred.

  The siloxane-modified polycarbonate is not particularly limited as long as the main chain, side chain, or terminal of the polycarbonate is modified with a compound having a siloxane skeleton. The number average molecular weight of the siloxane-modified polycarbonate is not particularly limited, and may be, for example, about 2000 or more and 30000 or less.

  It does not specifically limit as a manufacturing method of the polymer which has a siloxane bond, A well-known method is employ | adopted. As such a manufacturing method, it manufactures, for example by copolymerizing the compound and siloxane compound which give the said base polymer.

  In addition to the polymer having a siloxane bond, the heat fusion layer 3 preferably further contains a polycarbonate having no siloxane bond. Thus, the peeling strength of the heat sealing | fusion layer 3 can be easily adjusted by further containing the polycarbonate which does not have a siloxane bond, and adjusting the compounding quantity of this polycarbonate.

  The polycarbonate having no siloxane bond may be either a linear polycarbonate or a branched polycarbonate, or a mixture of both.

  The linear polycarbonate is a linear aromatic polycarbonate resin produced by a known phosgene method or melting method, and includes a carbonate component and a diphenol component. Examples of the precursor for introducing the carbonate component include phosgene and diphenyl carbonate. Examples of the diphenol include 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, and 1,1-bis (4-hydroxy). Phenyl) cyclohexane, 1,1-bis (3,5-dimethyl-4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) decane, 1,1-bis (4-hydroxyphenyl) propane, , 1-bis (4-hydroxyphenyl) cyclodecane, 1,1-bis (3,5-dimethyl-4-hydroxyphenyl) cyclododecane, 4,4′-dihydroxydiphenyl ether, 4,4′-thiodiphenol, 4 , 4′-dihydroxy-3,3′-dichlorodiphenyl ether, 4,4′-dihydroxy-2,5′-dihydride Carboxymethyl ether, and the like. These can be used alone or in combination of two or more. Such a linear polycarbonate is produced by, for example, the method described in US Pat. No. 3,998,672, and preferably has a refractive index of 1.57 or more and 1.59 or less.

  The branched polycarbonate is a polycarbonate produced using a branching agent. Examples of the branching agent include phloroglucin, trimellitic acid, 1,1,1-tris (4-hydroxyphenyl) ethane, and 1,1,2-tris. (4-hydroxyphenyl) ethane, 1,1,2-tris (4-hydroxyphenyl) propane, 1,1,1-tris (4-hydroxyphenyl) methane, 1,1,1-tris (4-hydroxyphenyl) ) Propane, 1,1,1-tris (2-methyl-4-hydroxyphenyl) methane, 1,1,1-tris (2-methyl-4-hydroxyphenyl) ethane, 1,1,1-tris (3 -Methyl-4-hydroxyphenyl) methane, 1,1,1-tris (3-methyl-4-hydroxyphenyl) ethane, 1,1,1-tris ( , 5-Dimethyl-4-hydroxyphenyl) methane, 1,1,1-tris (3,5-dimethyl-4-hydroxyphenyl) ethane, 1,1,1-tris (3-chloro-4-hydroxyphenyl) Methane, 1,1,1-tris (3-chloro-4-hydroxyphenyl) ethane, 1,1,1-tris (3,5-dichloro-4-hydroxyphenyl) methane, 1,1,1-tris ( 3,5-dichloro-4-hydroxyphenyl) ethane, 1,1,1-tris (3-bromo-4-hydroxyphenyl) methane, 1,1,1-tris (3-bromo-4-hydroxyphenyl) ethane 1,1,1-tris (3,5-dibromo-4-hydroxyphenyl) methane, 1,1,1-tris (3,5-dibromo-4-hydroxyphenyl) ethane, 4,4′- Hydroxy-2,5-dihydroxydiphenyl ether, and the like.

  Such a branched polycarbonate is, for example, as described in JP-A-3-182524, a polycarbonate oligomer derived from an aromatic diphenol, the above branching agent and phosgene, an aromatic diphenol, and a terminal. Stopper is reacted with stirring so that the reaction mixture containing these becomes a turbulent flow, and when the viscosity of the reaction mixture rises, an aqueous alkali solution is added and the reaction mixture becomes a laminar flow. It can be produced by a reaction method.

  When a siloxane-modified polycarbonate and a polycarbonate having no siloxane bond are used in combination, the mass ratio of the polycarbonate having no siloxane bond to the siloxane-modified polycarbonate is preferably 10% by mass or more and 1000% by mass or less. By controlling the mass ratio of the polycarbonate having no siloxane bond to the siloxane-modified polycarbonate within the above range, the occurrence of so-called bleed-out, in which the components of the heat-sealing layer ooze out while having sufficient peelability, is suppressed. Can do.

  Moreover, the said heat sealing | fusion layer 3 can contain a silicone oil, in order to improve the peeling effect. Generally, silicone oil refers to a polymer having a linear polysiloxane structure as a main structure. Depending on the type of organic group that replaces the side chain and terminal of this polysiloxane, it can be roughly classified into straight silicone oil and modified silicone oil. Straight silicone oil refers to those having a methyl group, phenyl group or hydrogen atom bonded to the side chain and / or terminal of the polysiloxane structure, and modified silicone oil refers to the side chain and / or terminal of the polysiloxane structure. Refers to an organic group other than a methyl group or a phenyl group.

  Examples of the straight silicone oil include a polysiloxane side chain, dimethyl silicone oil in which all ends are substituted with methyl groups, methylphenyl silicone oil in which a part of the side chain of the dimethyl silicone oil is substituted with phenyl groups, and the above dimethyl Examples thereof include methyl hydrogen silicone oil in which a part of the side chain of silicone oil is replaced with hydrogen.

  The modified silicone oil is further classified according to the bonding position of the organic group. Specifically, either a side chain type in which an organic group is introduced into part of a side chain of a linear polysiloxane, a double-end type in which an organic group is introduced into both ends of a linear polysiloxane, or a linear polysiloxane It is classified into a one-end type in which an organic group is introduced at one end and a side-chain both-end type in which an organic group is introduced at both ends and a part of a side chain of a linear polysiloxane.

  Examples of the organic group to be introduced include amino group, epoxy group, hydroxyl group, mercapto group, carboxyl group, polyether group, aralkyl group, alkyl group, fluoroalkyl group, phenyl group, fatty acid ester group, fatty acid amide group, and the like. Among them, a group in which two or more are combined is exemplified.

  Among these, a polyether-modified silicone oil in which a polyether group is introduced into a part of the side chain of polysiloxane is preferable. The number average molecular weight of the polyether-modified silicone oil is preferably, for example, 1,000 or more and 100,000 or less, and more preferably 2,000 or more and 50,000 or less. If the number average molecular weight is less than 1,000, silicone oil may ooze out on the surface of the heat-sealing layer, so-called bleeding out may occur. On the other hand, if the number average molecular weight exceeds 100,000, the intended peeling effect May not be obtained.

  Furthermore, the said heat sealing | fusion layer 3 can contain an ethylene-type polymer etc. other than the said component, for example.

  Examples of the ethylene polymer include polyethylene such as low density polyethylene, medium density polyethylene and high density polyethylene, ethylene-α olefin copolymer, ethylene- (meth) acrylic acid alkyl ester copolymer, ethylene-unsaturated carboxylic acid copolymer. A polymer, an ethylene- (meth) acrylate copolymer, an ethylene-vinyl ester copolymer, or the like can be used. These can be used alone or in combination of two or more.

  As an alpha olefin which comprises the said ethylene-alpha olefin copolymer, a propylene, 1-butene, 1-hexene, 1-octene, 4-methyl 1-pentene etc. can be used, for example.

  Examples of the (meth) acrylic acid alkyl ester constituting the ethylene- (meth) acrylic acid alkyl ester copolymer include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, (meth ) Isobutyl acrylate, n-butyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and the like can be used.

  Examples of the unsaturated carboxylic acid constituting the ethylene-unsaturated carboxylic acid copolymer include acrylic acid, methacrylic acid, fumaric acid, maleic acid, maleic anhydride, and the like.

  Examples of the vinyl ester constituting the ethylene-vinyl ester copolymer include vinyl acetate and vinyl propionate.

  Furthermore, what copolymerized the compound which has reactive functional groups, such as a glycidyl group, a silanol group, and an amino group, to the ethylene-type polymer can also be used.

  Moreover, it is also possible to mix additives, such as a ultraviolet absorber, a light stabilizer, and antioxidant, in the forming material of the heat-fusion layer 3. In this case, it is preferable that any one or a plurality of these additives is a polymer fixed type. As these additives, additives conventionally used in solar cell module protective films can also be used. For example, additives such as an organic peroxide, a crosslinking aid, a photopolymerization initiator, and a silane coupling agent can be mixed in the material for forming the heat-fusible layer 3.

  As the organic peroxide, it is preferable to employ an organic peroxide having a decomposition temperature of 145 ° C. or less with a half-life of 10 hours from the viewpoint of reactivity. Examples of the organic peroxide having a decomposition temperature of 10 hours with a half-life of 145 ° C. or lower include dilauroyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, dibenzoyl Peroxide, t-amylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxymaleic acid, 1,1- Di (t-amylperoxy) -3,3,5-trimethylcyclohexane, 1,1-di (t-amylperoxy) cyclohexane, t-amylperoxyisononanoate, t-amylperoxynormal octoate, 1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-di (t-butyl) -Oxy) cyclohexane, t-butylperoxyisopropyl carbonate, t-butylperoxy-2-ethylhexyl carbonate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-amyl-peroxybenzoate, t -Butyl peroxyacetate, t-butyl peroxyisononanoate, t-butyl peroxybenzoate, n-butyl-4,4-di- (t-butylperoxy) valerate, di (2-t-butylperoxy) Propyl) benzene, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, t-butylcumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl- Use of 2,5-di (t-butylperoxy) hexyne-3 or the like Kill. These organic peroxides can be used alone or in combination of two or more.

  The compounding amount of the organic peroxide is preferably 0.05 parts by mass or more and 5 parts by mass or less, and more preferably 0.1 parts by mass or more and 2 parts by mass or less with respect to 100 parts by mass of the ethylene polymer. If the amount of organic peroxide is less than the above lower limit, the formation of a crosslinked structure may be insufficient, and if it exceeds the upper limit, excessive reaction occurs and heat fusion is caused by decomposition or the like. There is a possibility that the forming material of the layer 3 is deteriorated.

  The crosslinking aid is an aid for improving the mechanical strength and the like of the thermal fusion layer 3 by crosslinking the material for forming the thermal fusion layer 3. As such a crosslinking aid, for example, a compound containing a (meth) acryloyl group, a compound containing an allyl group, or the like can be used.

  As a compound containing a (meth) acryloyl group, (meth) acrylic acid alkyl ester, (meth) acrylic acid amide, etc. can be used, for example. As the alkyl group of the (meth) acrylic acid alkyl ester, for example, methyl, ethyl, dodecyl and the like can be used.

  The blending amount of the crosslinking aid is preferably 0.05 parts by mass or more and 5 parts by mass or less, and more preferably 0.1 parts by mass or more and 2 parts by mass or less with respect to 100 parts by mass of the ethylene polymer. When the blending amount of the crosslinking aid is less than the above lower limit, the formation of the crosslinked structure may be insufficient, and when the upper limit is exceeded, the formation material of the heat fusion layer 3 may be deteriorated due to excessive reaction. is there.

  Furthermore, it is also possible to add a photopolymerization initiator to the material for forming the heat-fusible layer 3. As such a photopolymerization initiator, for example, a hydrogen abstraction type or an internal cleavage type can be used.

  As the hydrogen abstraction type (bimolecular reaction type) photopolymerization initiator, for example, benzophenone, methyl orthobenzoylbenzoate, 4-benzoyl-4'-methyldiphenyl sulfide, isopropylthioxanthone, or the like can be used.

  Further, as the internal cleavage type photopolymerization initiator, for example, benzoin alkyl ether, benzyl dimethyl ketal or the like can be used. Α-hydroxyalkylphenone type polymerization initiators such as 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, alkylphenylglyoxylate, and diethoxyacetophenone; Α-Aminoalkylphenone type such as -1- [4- (methylthio) phenyl] -2-morpholinopropane-1, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 A polymerization initiator, an acyl phosphine oxide, etc. can be used.

  Examples of the silane coupling agent include vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyltrimethoxysilane, γ- Glycidoxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-chloropropylmethoxysilane, vinyltrichlorosilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane or the like can be used. It is preferable that the compounding quantity of a silane coupling agent is 0.1 to 5 mass parts with respect to 100 mass parts of ethylene-type polymers. When the amount of the silane coupling agent is less than the above lower limit, the adhesiveness may be lowered, and when the upper limit is exceeded, sufficient heat resistance, light resistance, and weather resistance may not be obtained.

  As a minimum of the thickness (average thickness) of the heat sealing | fusion layer 3, 25 micrometers is preferable and 50 micrometers is more preferable. On the other hand, as an upper limit, 150 micrometers is preferable and 125 micrometers is more preferable. When the thickness of the heat sealing layer 3 is less than the above lower limit, the solar cell module protective film 1 and the solar cell module may be insufficiently bonded, and when the thickness exceeds the upper limit, the solar cell module. This is contrary to the demand for thinner and lighter weight.

  The heat-sealing layer 3 may contain at least one selected from a polyfunctional isocyanate compound having two or more functional groups capable of reacting with the hydroxyl group of the base polymer, a melamine compound, and an aminoplast resin. . Thereby, the polymer which has a siloxane bond is couple | bonded by a crosslinked structure, and storage stability, stain resistance, flexibility, a weather resistance, etc. become more favorable.

  The hydroxyl value of the base polymer of the heat fusion layer 3 is preferably 25 or more and 500 or less. If the hydroxyl value is less than 25, the crosslinking density is too low, the hardness or the like of the heat-sealing layer 3 may be reduced. On the other hand, if it exceeds 500, the crosslinking density is too high, the brittleness becomes brittle, cracks, chips, etc. May be easily damaged. The hydroxyl value is a value that can be measured by a method according to JIS-K0070, and is the number of milligrams of potassium hydroxide required to neutralize acetic acid produced when 1 g of the base polymer is acetylated. Means.

  Furthermore, for the purpose of improving and modifying the handling property, heat resistance, weather resistance, thermal dimensional stability, mechanical properties, etc., the heat-sealing layer 3 is provided with, for example, pigments, solvents, lubricants, fillers, reinforcing fibers. Various additives such as a reinforcing agent, an antistatic agent, a flame retardant, a flame retardant, a foaming agent, and an antifungal agent can be appropriately mixed.

  As a method for laminating the heat-fusible layer 3 on the base material layer 2, a known method can be appropriately employed. For example, the heat-sealing layer 3 can be provided by directly laminating the base material layer 2 by a T-die method using a coextrusion method or the like. In addition, a heat-sealing layer 3 is provided in advance on a substrate having releasability, such as a film and a sheet, and then the heat-sealing layer 3 is transferred onto the substrate layer 2 from the substrate having releasability. By doing so, the heat-fusible layer 3 may be provided. As a method of providing the heat-fusible layer 3 on the releasable base material, a known method can be appropriately employed. Examples include spray coating, dip coating, spin coating, knife coating, kiss coating, gravure coating, screen printing, ink jet printing, pad printing, and roll coating. Among these, it is preferable to use gravure coating from the viewpoint of productivity.

The amount of lamination of the heat sealable layer 3 as the lower limit of the (solid basis), for example, preferably ^{1g / m 2, 3g / m} 2 is more preferable. On the other hand, the upper limit of the laminated amount of heat sealable layer 3, for example, preferably 10 g / ^{m 2,} more preferably 7 g / ^{m 2.} When the lamination amount of the heat-fusible layer 3 is less than the above lower limit, sufficient peelability may not be obtained. On the other hand, when the lamination amount of the heat-fusible layer 3 exceeds the above upper limit, the lamination strength and durability may be lowered.

  As a minimum of the glass transition temperature of the heat sealing | fusion layer 3, 80 degreeC is preferable, for example, and 100 degreeC is more preferable. On the other hand, as an upper limit of the glass transition temperature of the heat sealing | fusion layer 3, 250 degreeC is preferable, for example, and 200 degreeC is more preferable. By making the glass transition temperature of the heat sealing | fusion layer 3 into the said range, the said protective film 1 for solar cell modules can be formed easily.

  The 180 ° peel strength at a tensile speed of 300 mm / min with respect to the glass plate in an environment of 23 ° C. × 50% RH of the heat-sealing layer is preferably 20 N / 10 mm or more and 200 N / 10 mm or less, and 30 N / 10 mm or more and 180 N / min. It is more preferably 10 mm or less, and further preferably 40 N / 10 mm or more and 150 N / 10 mm or less. By setting the 180 ° peel strength within the above range, it is possible to peel manually without the need for heating, and work efficiency during rework can be improved.

<The manufacturing method of the protective film 1 for solar cell modules>
As a manufacturing process of the said protective film 1 for solar cell modules, generally, (a) The composition for heat sealing layers is mixed by mixing the polymer etc. which have the siloxane bond which comprises the heat sealing layer 3. FIG. A step of preparing, and (b) a step of forming the heat-fusible layer 3 by laminating the composition for the heat-fusible layer on the surface of the base material layer 2 and curing it. The means for laminating the composition for heat-sealing layer is not particularly limited, and examples thereof include a bar coater, a blade coater, a spin coater, a roll coater, a gravure coater, a flow coater, a spray, a coating using screen printing, and the like. Adopted as appropriate.

  Since the said protective film 1 for solar cell modules has the heat sealing | fusion layer 3 containing the polymer which has a siloxane bond, it has favorable peelability. Therefore, the solar cell module using the protective film 1 for solar cell module can easily peel off the protective film 1 for solar cell module when the solar cell is damaged or the like. Can be exchanged. That is, the said protective film 1 for solar cell modules can aim at the improvement of the work efficiency of the rework operation | work of a solar cell module. Moreover, the said protective film 1 for solar cell modules is arrange | positioned by the surface side or back surface side of a solar cell module, when the heat sealing | fusion layer 3 is heat-seal | fused. As a result, the solar cell module components are protected by the solar cell module protective film 1.

<Solar cell module 21 (a)>
The solar cell module 21 (a) in FIG. 3 (a) has a translucent substrate 25, a filler layer 24, a solar battery cell 23, a filler layer 22 and the solar cell module protective film 1 in this order from the surface side. Are stacked.

  The translucent substrate 25 is laminated on the outermost surface, and a) has sunlight permeability and electrical insulation, b) mechanical, chemical and physical strength, specifically weather resistance. , Heat resistance, durability, water resistance, gas barrier properties against water vapor, wind pressure resistance, chemical resistance, fastness, (c) high surface hardness and prevent accumulation of dirt, dust, etc. on the surface It is required to have excellent antifouling properties.

  As a material for forming the translucent substrate 25, glass and synthetic resin are used. Examples of the synthetic resin used for the translucent substrate 25 include polyethylene resin, polypropylene resin, cyclic polyolefin resin, fluorine resin, polystyrene resin, acrylonitrile-styrene copolymer (AS resin), and acrylonitrile rubber. Butadiene-styrene copolymer (ABS resin), polyvinyl chloride resin, fluorine resin, poly (meth) acrylic resin, polycarbonate resin, polyester resin such as polyethylene terephthalate, polyethylene naphthalate, various nylons, etc. Polyamide resin, polyimide resin, polyamideimide resin, polyaryl phthalate resin, silicone resin, polyphenylene sulfide resin, polysulfone resin, acetal resin, polyethersulfone resin, polyurethane resin Fat, and cellulosic resins. Among these resins, fluorine resins, cyclic polyolefin resins, polycarbonate resins, poly (meth) acrylic resins, or polyester resins are particularly preferable.

  In the case of the translucent substrate 25 made of synthetic resin, (a) a transparent vapor-deposited film of an inorganic oxide such as silicon oxide or aluminum oxide on one surface by the PVD method or the CVD method for the purpose of improving gas barrier properties and the like (B) For the purpose of improving and modifying processability, heat resistance, weather resistance, mechanical properties, dimensional stability, etc., for example, lubricants, crosslinking agents, antioxidants, ultraviolet absorbers, antistatic agents Various additives such as an agent, a light stabilizer, a filler, a reinforcing fiber, a reinforcing agent, a flame retardant, a flame retardant, a foaming agent, a fungicide, and a pigment can also be contained.

  The thickness (average thickness) of the translucent substrate 25 is not particularly limited, and is appropriately selected depending on the material to be used so as to have required strength, gas barrier properties, and the like. The thickness of the synthetic resin translucent substrate 25 is preferably 6 μm or more and 300 μm or less, and more preferably 9 μm or more and 150 μm or less. Further, the thickness of the glass translucent substrate 25 is generally about 3 mm.

  The filler layer 22 and the filler layer 24 are filled around the solar battery cell 23 and have scratch resistance, shock absorption, and the like for protecting the solar battery cell 23. In addition, the filler layer 24 laminated | stacked on the surface of the photovoltaic cell 23 has transparency which permeate | transmits sunlight in addition to the said various functions.

  As a forming material of the filler layer 22 and the filler layer 24, for example, fluorine-based resin, ethylene-vinyl acetate copolymer resin (EVA), ionomer resin, ethylene-acrylic acid or methacrylic acid copolymer, polyethylene resin, polypropylene Resin, Polyolefin resin such as polyethylene, modified with unsaturated carboxylic acid such as acrylic acid, acid-modified polyorene fin resin, polyvinyl butyral resin, silicone resin, epoxy resin, (meth) acrylic resin, etc. . Among these synthetic resins, fluorine resins, silicone resins, or ethylene-vinyl acetate copolymer resins that are excellent in weather resistance, heat resistance, gas barrier properties, and the like are preferable.

  Moreover, as a forming material of the filler layer 22 and the filler layer 24, the thermoreversible crosslinkable olefin polymer composition shown by Unexamined-Japanese-Patent No. 2000-34376, specifically (a) unsaturated carboxylic anhydride Modified olefin polymer modified with a product and an unsaturated carboxylic acid ester, wherein the average number of carboxylic anhydride groups per molecule is one or more, and the carboxylic acid in the modified olefin polymer A modified olefin polymer in which the ratio of the number of carboxylic acid ester groups to the number of acid anhydride groups is 0.5 to 20; and (b) a hydroxyl group-containing polymer having an average number of hydroxyl groups per molecule of 1 or more. The ratio of the number of hydroxyl groups in component (b) to the number of carboxylic anhydride groups in component (a) is 0.1 to 5.

  For the purpose of improving the weather resistance, heat resistance, gas barrier properties, etc., the forming material of the filler layer 22 and the filler layer 24 is, for example, a crosslinking agent, a thermal antioxidant, a light stabilizer, an ultraviolet absorber, a light absorber, and the like. Various additives such as an antioxidant can be appropriately contained. In addition, the thickness (average thickness) of the filler layer 22 and the filler layer 24 is not particularly limited, but is preferably 200 μm or more and 1000 μm or less, and more preferably 350 μm or more and 600 μm or less.

The solar battery cell 23 is a photovoltaic element that converts light energy into electrical energy, and is disposed between the filler layer 22 and the filler layer 24. The plurality of solar cells 23 are laid in substantially the same plane, and are wired in series or in parallel although not shown. Examples of the solar battery cell 23 include a crystalline silicon solar electronic element such as a single crystal silicon type solar cell element and a polycrystalline silicon type solar cell element, an amorphous silicon solar cell element having a single junction type or a tandem structure type, and gallium arsenide. Group 3 to 5 compound semiconductor solar electronic devices such as (GaAs) and indium phosphorus (InP), and Group 2 to 6 compound semiconductor solar electronic devices such as cadmium tellurium (CdTe) and copper indium selenide (CuInSe ₂ ) Etc., and those hybrid elements can also be used. Note that the filler layer 22 and the filler layer 24 are also filled between the plurality of solar battery cells 23 without any gap.

<Method for Manufacturing Solar Cell Module 21 (a)>
Although it does not specifically limit as a manufacturing method of the said solar cell module 21 (a), Generally, (1) The filler layer 24, the photovoltaic cell 23, the filler layer 22, and the said solar It has a step of laminating the battery module protective film 1 in this order, and (2) a lamination step of integrally forming them by a vacuum heating lamination method in which they are integrated by vacuum suction and thermocompression bonded. Moreover, in the manufacturing method of the said solar cell module 21 (a), for the purpose of the adhesiveness etc. between the photovoltaic cell 23, the filler layer 22, and the filler layer 24, for example, a heat-melt-type adhesive agent, a solvent type | mold Apply adhesive, photo-curing adhesive, etc., corona discharge treatment, ozone treatment, low temperature plasma treatment, glow discharge treatment, oxidation treatment, primer coat treatment, undercoat treatment, anchor coat treatment, etc. Can be applied.

  The solar cell module 21 (a) has good peelability when the heat-sealing layer 3 of the solar cell module protective film 1 contains a polymer having a siloxane bond as described above. Therefore, the solar cell module 21 (a) can easily peel off the protective film 1 for solar cell modules when the solar cell is damaged, and the like. It can be carried out. That is, the solar cell module 21 (a) can improve the work efficiency of the rework work. Therefore, the solar cell module 21 (a) can be suitably used for a roof-standing solar cell module.

[Second Embodiment]
(B) of FIG.2 and FIG.3 is the solar cell module backsheet which concerns on a different form from the said (a) of FIG.1 and FIG.3. The protective film 11 for a solar cell module includes a heat fusion layer 3 on the surface of the base material layer 2 and a gas barrier layer 12 on the back surface of the base material layer 2. Further, a hydrolysis resistant layer 13 is laminated on the back surface of the gas barrier layer 12.

  Since this base film 2 and the heat sealing | fusion layer 3 are the same as that of the said protective film 1 for solar cell modules, the same number is attached | subjected and description is abbreviate | omitted.

<Gas barrier layer>
The gas barrier layer 12 is a layer having a function of reducing permeation of gas such as hydrogen gas and oxygen gas. The gas barrier layer 12 includes a base film (not shown) and an inorganic oxide layer (not shown) laminated on the base film.

  The base film of the gas barrier layer 12 is formed with a synthetic resin as a main component. As the synthetic resin as the main component of the base film, the same synthetic resin as that of the base layer 2 is used. Among them, polyethylene terephthalate having a good balance between various functions such as heat resistance and weather resistance and a price is particularly preferable. preferable. The base film forming method and the additives in the base film forming material are the same as those of the base layer 2.

  As a minimum of the thickness (average thickness) of the above-mentioned substrate film, 7 micrometers is preferred and 10 micrometers is more preferred. On the other hand, as an upper limit of the thickness of a base film, 20 micrometers is preferable and 15 micrometers is more preferable. When the thickness of the base film is less than the above lower limit, there is a possibility that inconveniences such as curling easily occur during vapor deposition for forming the inorganic oxide layer, and handling becomes difficult. . On the contrary, if the thickness of the substrate film exceeds the above upper limit, it is contrary to the demand for thinning and lightening the solar cell module.

  The inorganic oxide layer is a layer for expressing gas barrier properties against oxygen, water vapor, and the like, and is formed by depositing an inorganic oxide on the back surface of the base film. The vapor deposition means for forming this inorganic oxide layer is not particularly limited as long as the inorganic oxide can be vapor deposited on the synthetic resin base film without causing deterioration such as shrinkage and yellowing. (A) Physical vapor deposition method (Physical Vapor Deposition method; PVD method) such as vacuum deposition method, sputtering method, ion plating method, ion cluster beam method, (b) Plasma chemical vapor deposition method, thermal chemical vapor deposition method, A chemical vapor deposition method (Chemical Vapor Deposition method; CVD method) such as a photochemical vapor deposition method is employed. Among these vapor deposition methods, a vacuum vapor deposition method and an ion plating method that can form a high-quality inorganic oxide layer with high productivity are preferable.

  The inorganic oxide constituting the inorganic oxide layer is not particularly limited as long as it has gas barrier properties. For example, aluminum oxide, silica oxide, titanium oxide, zirconium oxide, zinc oxide, tin oxide, magnesium oxide Among them, aluminum oxide or silica oxide having a good balance between gas barrier properties and price is particularly preferable.

  The lower limit of the thickness (average thickness) of the inorganic oxide layer is preferably 3 mm, more preferably 400 mm. On the other hand, the upper limit of the thickness of the inorganic oxide layer is preferably 3000 mm, more preferably 800 mm. If the thickness of the inorganic oxide layer is smaller than the above lower limit, the gas barrier property may be lowered. On the other hand, when the thickness of the inorganic oxide layer exceeds the above upper limit, the flexibility of the inorganic oxide layer is reduced, and defects such as cracks are likely to occur.

  The inorganic oxide layer may have a single layer structure or a multilayer structure of two or more layers. By making the inorganic oxide layer into a multilayer structure in this way, the deterioration of the base film is reduced by reducing the thermal burden applied during vapor deposition, and the adhesion between the base film and the inorganic oxide layer is further improved. can do. The vapor deposition conditions in the physical vapor deposition method and the chemical vapor deposition method are appropriately designed according to the resin type of the base film, the thickness of the inorganic oxide layer, and the like.

  Moreover, in order to improve the close adhesiveness etc. of a base film and an inorganic oxide layer, it is good to give a surface treatment to the vapor deposition surface of a base film. Examples of such adhesion improving surface treatment include (a) corona discharge treatment, ozone treatment, low temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, oxidation treatment using chemicals, and the like ( b) Primer coat treatment, undercoat treatment, anchor coat treatment, vapor deposition anchor coat treatment and the like. Among these surface treatments, corona discharge treatment and anchor coat treatment that improve adhesion strength with the inorganic oxide layer and contribute to the formation of a dense and uniform inorganic oxide layer are preferable.

  Examples of the anchor coating agent used for the anchor coating treatment include a polyester anchor coating agent, a polyamide anchor coating agent, a polyurethane anchor coating agent, an epoxy anchor coating agent, a phenol anchor coating agent, and a (meth) acrylic anchor coating. Agents, polyvinyl acetate anchor coating agents, polyolefin anchor coating agents such as polyethylene aly polypropylene, and cellulose anchor coating agents. Among these anchor coating agents, polyester anchor coating agents that can further improve the adhesive strength between the base film and the inorganic oxide layer are particularly preferable.

The lower limit of the coating amount of the anchor coating agent (in terms of solid content), preferably from ^{0.1g / m 2, 1g / m} 2 is more preferable. In contrast, the upper limit of the amount of coating of the anchor coating agent is preferably ^{5g / m 2, 3g / m} 2 is more preferable. If the coating amount of the anchor coating agent is smaller than the above lower limit, the effect of improving the adhesion between the base film and the inorganic oxide layer may be reduced. On the other hand, when the coating amount of the anchor coating agent exceeds the above upper limit, the strength, durability, etc. of the gas barrier layer 12 may be lowered.

  In the anchor coating agent, a silane coupling agent for improving tight adhesion, a blocking inhibitor for preventing blocking with a base film, an ultraviolet absorber for improving weather resistance, etc. Various additives can be appropriately mixed. The amount of the additive to be mixed is preferably 0.1% by weight or more and 10% by weight or less from the balance between the effect expression of the additive and the function inhibition of the anchor coating agent.

<Hydrolysis resistant layer>
The hydrolysis-resistant layer 13 is formed with a synthetic resin as a main component. Polyethylene naphthalate (PEN), which is excellent in hydrolysis resistance and heat resistance, is used as a synthetic resin as a main component of the hydrolysis resistant layer 13.

  The polyethylene naphthalate is a polyester resin having ethylene naphthalate as a main repeating unit, and synthesized using naphthalenedicarboxylic acid as a main dicarboxylic acid component and ethylene glycol as a main glycol component.

  The ethylene naphthalate unit is preferably 80 mol% or more of all repeating units of the polyester. If the proportion of ethylene naphthalate units is less than 80 mol%, the hydrolysis resistance, strength, and barrier properties of polyethylene naphthalate may be reduced.

  Examples of the naphthalenedicarboxylic acid include 2,6-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, and the like. In view of surface, 2,6-naphthalenedicarboxylic acid is particularly preferable.

  The hydrolysis-resistant layer 13 may contain a carbodiimide compound in polyethylene naphthalate which is a main component. Thus, by containing a carbodiimide compound, the hydrolysis resistance of the hydrolysis-resistant layer 13 is remarkably improved. As content of this carbodiimide compound, 0.1 mass% or more and 10 mass% or less are preferable, and 0.5 mass% or more and 3 mass% or less are more preferable. Thus, by making content of a carbodiimide compound into the said range, the hydrolysis resistance of the hydrolysis-resistant layer 13 can be improved effectively.

  Examples of the carbodiimide compound include (a) N, N′-diphenylcarbodiimide, N, N′-diisopropylphenylcarbodiimide, N, N′-dicyclohexylcarbodiimide, 1,3-diisopropylcarbodiimide, and 1- (3-dimethylaminopropyl). And monocarbodiimides such as (3-ethylcarbodiimide) and (b) polycarbodiimide compounds such as poly (1,3,5-triisopropylphenylene-2,4-carbodiimide). Among these, N, N′-diphenylcarbodiimide and N, N′-diisopropylphenylcarbodiimide are preferable, and the hydrolysis resistance of the hydrolysis-resistant layer 13 can be further improved. Moreover, as a molecular weight of a carbodiimide compound, the range of 200-1000, especially the range of 200-600 are preferable. When the molecular weight is less than the above lower limit, the scattering property of the carbodiimide compound may increase, and when the molecular weight exceeds the upper limit, the dispersibility of the carbodiimide compound in the resin may decrease.

  The hydrolysis resistant layer 13 may contain an antioxidant in addition to the carbodiimide compound in polyethylene naphthalate, which is the main component. Thus, by including both a carbodiimide compound and antioxidant in polyethylene naphthalate, the said hydrolysis resistance improves markedly, Furthermore, decomposition | disassembly of a carbodiimide compound can also be suppressed. As content of this antioxidant, 0.05 mass% or more and 1 mass% or less are preferable, and 0.1 mass% or more and 0.5 mass% or less are more preferable. When the content of the antioxidant is less than the above lower limit, the carbodiimide decomposition inhibiting function and the hydrolysis resistance may be reduced, and when the content of the antioxidant exceeds the upper limit, the hydrolysis resistant layer 13. There is a risk that the color tone of the product may be impaired. As the antioxidant, specifically, hindered phenol compounds and thioether compounds, particularly hindered phenol compounds, are preferable, and the hydrolysis resistance of the hydrolysis resistant layer 13 can be effectively improved. . The mass ratio of the antioxidant content to the carbodiimide compound content is preferably 0.1 or more and 1.0 or less, and more preferably 0.15 or more and 0.8 or less. If this mass ratio is less than the above lower limit, the effect of suppressing hydrolysis of carbodiimide itself may be insufficient, while if this mass ratio exceeds the above upper limit, the effect of suppressing hydrolysis of carbodiimide will reach its peak. Become. In addition, the addition method of a carbodiimide compound and antioxidant may be a method of kneading to polyethylene naphthalate or a method of adding to a polycondensation reaction of polyethylene naphthalate.

  The terminal carboxyl group amount of polyethylene naphthalate is preferably 10 eq / T (equivalent / 106 g) or more and 40 eq / T or less, particularly preferably 10 eq / T or more and 30 eq / T or less, more preferably 10 eq / T or more and 25 eq / T or less. When the amount of the terminal carboxyl group is less than the above lower limit, the productivity may decrease. On the other hand, when the amount of the terminal carboxyl group exceeds the above upper limit, the effect of improving the hydrolysis resistance by the carbodiimide compound may be decreased.

  The hydrolysis resistant layer 13 may contain an aromatic polyester in addition to polyethylene naphthalate. Thus, by containing an aromatic polyester in polyethylene naphthalate, knot strength, delamination resistance, mechanical strength, and the like can be improved while maintaining the hydrolysis resistance of the hydrolysis resistant layer 13. As content of this aromatic polyester, 1 to 10 mass% is preferable. By making content of aromatic polyester into the said range, knot strength, delamination resistance, mechanical strength, etc. can be improved effectively. Specifically, the aromatic polyester is preferably a polyester obtained by copolymerizing a terephthalic acid component and 4,4'-diphenyldicarboxylic acid as a main dicarboxylic acid component and ethylene glycol as a main glycol component.

  In addition, the manufacturing method of polyethylene naphthalate is not specifically limited, Various well-known methods, such as a transesterification method and a direct esterification method, are employable. Further, the forming method of the hydrolysis-resistant layer 13 and the additives in the forming material of the hydrolysis-resistant layer 13 are the same as those of the substrate layer 2.

  As a minimum of the thickness of the hydrolysis-resistant layer 13, 12 micrometers is preferable and 25 micrometers is more preferable. On the other hand, the upper limit of the thickness of the hydrolysis-resistant layer 13 is preferably 50 μm, and more preferably 40 μm. When the thickness of the hydrolysis-resistant layer 13 is less than the above lower limit, the effect of improving the durability of the hydrolysis-resistant layer 13 due to the hydrolysis resistance of polyethylene naphthalate may not be sufficiently exhibited, making it difficult to handle, etc. Inconvenience also occurs. On the other hand, when the thickness of the hydrolysis-resistant layer 13 exceeds the above upper limit, it is against the request for thinning and lightening the solar cell module.

<Method for Manufacturing Protective Film 11 for Solar Cell Module>
As a manufacturing process of the said protective film 11 for solar cell modules, generally, (a) The process of preparing the composition for heat sealing layers which comprises the heat sealing layer 3, (b) This heat sealing | fusion Laminating the layer composition on the surface of the base material layer 2 and curing it, and (c) forming the gas barrier layer 12 on the back surface of the base material layer 2; d) a step of laminating a hydrolysis-resistant layer composition for forming a hydrolysis-resistant layer 13 on the outside of the gas barrier layer 12. The means for laminating the composition for heat fusion layer and the composition for hydrolysis resistant layer is not particularly limited, and for example, bar coater, blade coater, spin coater, roll coater, gravure coater, flow coater, spray, A coating using screen printing or the like is appropriately employed.

  Since the solar cell module protective film 11 has good peelability as in the embodiment of FIG. 1 described above, the rework work is easy and the work efficiency can be improved.

<Solar cell module 21 (b)>
The solar cell module 21 (b) in FIG. 3 (b) has a light-transmitting substrate 25, a filler layer 24, solar cells 23, a filler layer 22 and the solar cell module protective film 11 in this order from the surface side. Are stacked.

  Since the translucent substrate 25, the filler layer 24, the solar battery cell 23, and the filler layer 22 of the solar battery module 21 (b) are the same as those of the solar battery module 21 (a), the same reference numerals are used for description. Is omitted.

<Method for Manufacturing Solar Cell Module 21 (b)>
The manufacturing method of the solar cell module 21 (b) is not particularly limited as in the case of the solar cell module 21 (a), but in general, (1) the filler layer 24 and the solar cell A step of laminating the cells 23, the filler layer 22 and the solar cell module protective film 11 in this order; and (2) integral molding by a vacuum heating lamination method or the like in which they are integrated by vacuum suction and thermocompression bonded. Laminating process. Moreover, also in the manufacturing method of the said solar cell module 21 (b), for the purpose of the adhesiveness etc. between the photovoltaic cell 23, the filler layer 22, and the filler layer 24, for example, a heat-melt type adhesive agent, a solvent type | mold Apply adhesive, photo-curing adhesive, etc., corona discharge treatment, ozone treatment, low temperature plasma treatment, glow discharge treatment, oxidation treatment, primer coat treatment, undercoat treatment, anchor coat treatment, etc. It is possible to apply.

  Since the solar cell module 21 (b) has excellent removability as described above, the heat-sealable layer 3 of the solar cell module protective film 11 is easy to rework and improve work efficiency. Can do. In addition, the solar cell module 21 (b) is provided with the gas barrier layer 12, so that the gas barrier property, durability, weather resistance, and the like against oxygen, water vapor, and the like are improved, and the solar cell module 21 (b) is preferably used for a long time outdoors. it can. Moreover, since the said solar cell module 21 (b) is equipped with the hydrolysis-resistant layer 13, durability, a weather resistance, etc. are improved, Therefore It can be used conveniently for a roof-standing type solar cell module. .

[Other Embodiments]
In addition, the protective film for solar cell modules and solar cell module of this invention are not limited to the said embodiment. Specifically, a plurality of beads may be included in the base material layer 2 or the heat sealing layer 3, and beads may be included in both the base material layer 2 and the heat sealing layer 3. Moreover, the said protective film for solar cell modules may laminate | stack other layers (for example, UV absorption layer etc.) between the base material layer 2 and the heat sealing | fusion layer 3. FIG. Moreover, the protective film for solar cell modules may be installed on the back surface of the solar cell module as in the above embodiment, or may be installed on the surface of the solar cell module, and both the front surface and the back surface of the solar cell module. It may be installed in.

  EXAMPLES Hereinafter, although this invention is explained in full detail based on an Example, this invention is not interpreted limitedly based on description of this Example.

[Manufacture of protective film for solar cell module]
Each protective film for a solar cell module was produced by laminating a base material layer and a heat fusion layer made of the materials shown in Table 1 below by a co-extrusion method. In Table 1 below, “PET” means “polyethylene terephthalate”, “PDMS-modified PC” means “polydimethylsiloxane-modified polycarbonate”, and “PC” means “polycarbonate”.

[Characteristic evaluation]
A peel test was conducted using the solar cell module protective films of the above Examples and Comparative Examples. Specifically, first, a glass substrate, a filler composed of an ethylene vinyl acetate copolymer (EVA) and the protective film for solar cell module are laminated in this order, and 150 ° C. using a vacuum laminator (manufactured by NPC). The laminate was performed under the condition of × 20 minutes. Subsequently, the peeling force of the protective film for solar cell modules was measured on the conditions of 180 degree | times peeling and peeling speed 300mm / min using the tensile tester. Moreover, the protective film of each solar cell module produced similarly was peeled by the hand of man. The results are shown in Table 2 below. In Table 2 below, “material breakage” means a case where the protective film for solar cell module is broken before peeling because of high adhesive strength.

  As shown in Table 2 above, the protective films for solar cell modules of Example 1 using PDMS-modified PC as the thermal fusion layer and Examples 2 and 3 using PDMS-modified PC and PC as the thermal fusion layer were Even after being integrally formed as a solar cell module, it could be easily peeled off with the help of human hands alone. On the other hand, in Comparative Example 1 using PET as the heat-sealable layer, the adhesive strength was strong and could not be peeled only by the power of human hands. In the 180 degree peel test, the protective film was broken before peeling.

  As described above, the protective film for a solar cell module of the present invention can be easily peeled even after being integrally formed as a solar cell module. Therefore, the solar cell module using this can perform the rework work easily and efficiently. Thus, the protective film for a solar cell module of the present invention and the solar cell module using the same are useful as a constituent element of a solar cell and are preferably used.

DESCRIPTION OF SYMBOLS 1 Protective film for solar cell modules 2 Base material layer 3 Thermal fusion layer 11 Protective film for solar cell modules 12 Gas barrier layer 13 Hydrolysis resistant layer 21 (a) Solar cell module 21 (b) Solar cell module 22 Filler layer 23 Solar cell 24 Filler layer 25 Translucent substrate 31 Solar cell module 32 Translucent substrate 33 Filler layer 34 Solar cell 35 Filler layer 40 Back sheet A Surface direction

Claims (10)

A base layer made of synthetic resin;
A thermal fusion layer laminated on one surface side of the base material layer,
The protective film for solar cell modules, wherein the heat-sealing layer contains a polymer having a siloxane bond.   The protective film for a solar cell module according to claim 1, wherein the polymer having a siloxane bond is a siloxane-modified polycarbonate.   The protective film for solar cell modules according to claim 2, wherein the heat-fusible layer further contains a polycarbonate having no siloxane bond.   The protective film for a solar cell module according to claim 3, wherein a mass ratio of the polycarbonate having no siloxane bond to the siloxane-modified polycarbonate is 10% by mass or more and 1000% by mass or less.   5. The 180 ° peel strength at a tensile speed of 300 mm / min with respect to the glass plate in an environment of 23 ° C. × 50% RH of the heat fusion layer is 20 N / 10 mm or more and 200 N / 10 mm or less. The protective film for solar cell modules of Claim 1.   The protective film for a solar cell module according to any one of claims 1 to 5, wherein a pigment is dispersed and contained in the heat sealing layer.   The protective film for solar cell modules according to any one of claims 1 to 6, further comprising a hydrolysis-resistant layer on the other surface side of the base material layer.   The protective film for solar cell modules according to any one of claims 1 to 7, further comprising a gas barrier layer on the other surface side of the base material layer.   The protective film for solar cell modules of any one of Claims 1-8 adhere | attached on the back surface side of the photovoltaic cell of a solar cell module with the said heat sealing | fusion layer.   A translucent substrate, a filler layer, a solar battery cell as a photovoltaic element, a filler layer, and the protective film for a solar battery module according to any one of claims 1 to 9. Solar cell modules stacked in this order.

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