JP2012209375A - Sealing material/surface protective material laminate for solar cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide realization of a sealing material/a surface protective material laminate for a solar cell, being excellent in sealability and having a good appearance, for example, fewer wrinkles and the like.SOLUTION: A sealing material/a surface protective material laminate for a solar cell has (1) a sealing material comprising a resin composition containing a cyclic olefin-based polymer and having a melt viscosity of 2000 Pa s or more and less than 15000 Pa s at 150°C as measured at a frequency of 1 Hz, and (2) a surface protective material comprising a plastic film having a melting point of 180°C or less.

Description

  The present invention relates to a solar cell sealing material / surface protective material laminate in which a solar cell sealing material and a surface protective material are combined together, and is particularly excellent in moisture proofing, appearance, and manufacturing process savings. The present invention relates to a solar cell encapsulant / surface protective material laminate effective for weight reduction and durability of a solar cell, and a lightweight and highly durable solar cell module.

In recent years, solar cells that directly convert sunlight into electric energy have attracted attention and are being developed from the viewpoint of effective use of resources and prevention of environmental pollution. A solar cell is usually manufactured by laminating a front protective material, a sealing material, a power generation element, a sealing material, and a back protective material in this order, and bonding and integrating them by heating and melting by vacuum lamination.
The sealing material has various requirements such as flexibility and impact resistance for protecting the solar cell element, heat resistance when the solar cell module generates heat, durability, dimensional stability, flame retardancy, water vapor barrier property, etc. However, it is important that the sealing ability in the sealing process, that is, the constituent resin of the sealing material does not flow out to the periphery of the module and that the resin is sufficiently sealed and goes into the details of the photovoltaic device. It is. For this reason, an ethylene-vinyl acetate copolymer (hereinafter sometimes abbreviated as EVA) has been widely used as the resin.

As a surface protection material that is a front and back surface protection material for solar cells, it is an important requirement to have excellent durability against ultraviolet rays, moisture resistance, etc. The typical layer structure is a weather resistant film, moisture proof film, and intermediate layer from the exposed side. What consists of a film and a sealing material adhesion | attachment film is known.
As described above, various functions are required for both the sealing material and the surface protective material. However, when the sealing material and the surface protective material of the solar cell are integrated, the generation of wrinkles and protrusions can be further prevented. It is required to have excellent adhesion strength. As an integrated solar cell sealing material / surface protective material laminate, for example, as disclosed in Patent Documents 1 and 2, a solar cell surface protective material and a sealing EVA film are laminated and integrated. A solar cell cover material combined sealing film is known.

Japanese Patent No. 3978911 Japanese Patent No. 3978912

The inventors of the present invention are that wrinkles are generated at the interface between the sealing material and the solar cell element or the interface between the sealing material and the surface protection material due to the shrinkage of EVA conventionally used as the sealing material. It has been found that the shrinkage of the EVA is due to the fact that the crosslinking agent made of an organic peroxide used for the purpose of imparting heat resistance acts in the vacuum lamination process of the module manufacturing process.
Furthermore, a film having a melting point higher than the vacuum lamination temperature such as a polyester film used for the construction of a surface protection material for solar cells (hereinafter referred to as a “high melting point intermediate film”, specifically, a film having a melting point higher than 180 ° C. Has been found to play a role in preventing deformation of the surface protective material and generation of wrinkles on the surface. This is because the generation of wrinkles is due to shrinkage and / or deformation of the sealing material and the surface protective material itself due to vacuum lamination, and the high melting point intermediate film constituting the surface protective material is a vacuum lamination step. This is considered to be due to the effect of resisting the shrinkage of the sealing material.
That is, in the sealing film for a solar cell cover material disclosed in Patent Documents 1 and 2, since the shrinkage of the sealing EVA film is large, a high-melting-point intermediate film is used for the structure of the integrated surface protection material. Otherwise, wrinkles and the like are generated, resulting in poor appearance.

  However, the use of the high-melting-point intermediate film leads to an increase in the laminated film of the surface protective material, and at the same time, complicates the manufacturing process and increases the amount of solvent used. Therefore, without using a high melting point intermediate film, a sealing material for solar cells is used by using a sealing material that is excellent in sealing properties and has little shrinkage so that wrinkles such as surface protective materials do not occur. It is necessary to design a surface protective material laminate.

  That is, an object of the present invention is to realize a solar cell encapsulant / surface protective material laminate having a good appearance such as excellent sealing properties and few wrinkles, and further, this solar cell encapsulant. An object of the present invention is to provide a solar cell module and a solar cell having a long-term durability excellent in appearance by using a laminate of a stopping material and a surface protective material.

  The present invention is (1) a sealing composition comprising a resin composition containing a cyclic olefin polymer, wherein the melt viscosity at 150 ° C. measured at a frequency of 1 Hz is 2000 Pa · s or more and less than 15000 Pa · s. The present invention relates to a solar cell sealing material / surface protective material laminate having a material and (2) a surface protective material made of a plastic film having a melting point of 180 ° C. or lower.

  According to the present invention, it has excellent sealing properties, and even without the use of a high melting point intermediate film, the appearance of remarkable wrinkles, protrusions, peeling, etc. does not occur on the laminated surface with the surface protective material, and a good appearance is obtained. The solar cell encapsulant / surface protective material laminate can be realized. In addition, according to the present invention, a solar cell module and a solar cell having long-term durability that are not only excellent in appearance because of the use of the laminate but also that are not easily damaged due to deformation due to prevention of deformation. Can be provided.

The present invention is described in further detail below.
<Laminated solar cell encapsulant / surface protective material laminate>
The solar cell encapsulant / surface protective material laminate of the present invention includes an encapsulant that is a resin composition containing a cyclic olefin exhibiting a specific viscosity (hereinafter sometimes referred to as “cycloolefin encapsulant”). A sealing material / surface protective material laminate in which a surface protective material made of a plastic film having a melting point of 180 ° C. or lower is laminated, and has excellent sealing properties and appearance in a laminated body after vacuum lamination, thereby reducing the number of processes. This makes it possible to reduce the amount of solvent used.

  That is, the solar cell encapsulant / surface protective material laminate of the present invention is (1) a resin composition containing a cyclic olefin polymer, and has a melt viscosity of 2000 Pa · s at 150 ° C. measured at a frequency of 1 Hz. As mentioned above, it has the sealing material which consists of a resin composition which is less than 15000 Pa.s, and (2) the surface protection material which consists of a sealing material adhesion film of melting | fusing point 180 degrees C or less, Preferably, the said surface protection material However, it has a sealing material adhesion film having a melting point of 180 ° C. or lower and a weather resistant film having a melting point of 180 ° C. or lower.

In the present invention, the “melting point of the film” refers to a temperature of about 10 mg of a measurement film sample heated from −40 ° C. to 200 ° C. at a heating rate of 10 ° C./min using a differential scanning calorimeter according to JIS K7121. The melting peak was confirmed, held at 200 ° C. for 1 minute, then cooled down to −40 ° C. at a cooling rate of 10 ° C./min, and then measured again when the temperature was raised to 200 ° C. at a heating rate of 10 ° C./min. From Gram, the maximum peak among the crystal melting peak temperatures is (Tm) (° C.) as the melting point. In addition, when melting | fusing point exceeds 200 degreeC, such as polyester, and a melting peak is not observed, the temperature rising upper limit temperature shall be 300 degreeC, and the same measurement is performed after that.
Hereinafter, each constituent layer will be described.

[(1) Cyclic olefin sealing material]
The cyclic olefin encapsulant in the solar cell encapsulant / surface protective material laminate of the present invention is a resin composition containing a cyclic olefin polymer, and the melt viscosity at 150 ° C. measured at a frequency of 1 Hz is 2000 Pa ·. It is a sealing material having moisture resistance and transparency made of a resin composition of s or more and less than 15000 Pa · s. The cyclic olefin sealing material is a sealing material having at least one layer made of a resin composition containing a cyclic olefin polymer.
By using a layer made of a resin composition containing this cyclic olefin polymer, the inner surface side of the solar cell by moisture and water permeation can be protected, and power generation efficiency can be improved by ensuring high transparency. Improvement can be achieved.

(Cyclic olefin polymer)
The cyclic olefin polymer used in the present invention can mainly include the following three types (A) to (C).
(A): Cyclic olefin-based random copolymer composed of a linear olefin component and a cyclic olefin component represented by the following general formula (1) (B): From a cyclic olefin represented by the following general formula (1) Ring-opening polymer comprising one or more selected cyclic olefin components or a hydride thereof (C): a mixture of (A) and (B) above

(In the general formula (1), R _{1 to} R ₁₂ are each a hydrogen atom or a hydrocarbon group and may be the same or different. R ₅ and R ₁₀ , or R ₁₁ and R It may be integrated with ₁₂ to form a divalent hydrocarbon group, or R ₃ or R ₁₀ and R ₁₁ or R ₁₂ may form a ring with each other, n is 0 or positive When it is an integer and n is 2 or more and there are a plurality of each of R _{5 to} R ₈ , these may be the same or different.

  Here, examples of the cyclic olefin represented by the general formula (1) include bicyclohept-2-ene (2-norbornene) of the following formula (2) and derivatives thereof such as norbornene, 6-methylnorbornene, 6 -Ethylnorbornene, 6-n-butylnorbornene, 5-propylnorbornene, 1-methylnorbornene, 7-methylnorbornene, 5,6-dimethylnorbornene, 5-phenylnorbornene, 5-benzylnorbornene and the like can be mentioned.

  Examples of the cyclic olefin represented by the general formula (1) include tetracyclo-3-dodecene of the following formula (3) and derivatives thereof, such as 8-methyltetracyclo-3-dodecene, 8-ethyltetracyclo- Examples include 3-dodecene, 8-hexyltetracyclo-3-dodecene, 10-dimethyltetracyclo-3-dodecene, and 5,10-dimethyltetracyclo-3-dodecene.

  The cyclic olefin-based random copolymer having the configuration (A) is a copolymer of a linear olefin component and the cyclic olefin component represented by the general formula (1), and has fluidity, transparency, and water vapor. It is preferably used in the present invention in terms of barrier properties. As the linear olefin component to be copolymerized with the cyclic olefin component, an α-olefin having 2 to 20 carbon atoms is preferably used. For example, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1 -Heptene, 1-octene, 1-nonene, 1-decene, 3-methyl-butene-1, 4-methyl-pentene-1, and the like. In the present invention, ethylene is preferably used as the linear olefin component, and norbornene or tetracyclododecene is preferable as the cyclic olefin component from the viewpoints of industrial availability, various characteristics, and economical efficiency. Used for. The cyclic olefin component and the linear olefin component to be copolymerized may be used alone or in combination of two or more.

  The content (mol%) of the cyclic olefin component in the cyclic olefin-based random copolymer is not particularly limited, but when the ethylene-norbornene random copolymer is taken as an example, the norbornene component is preferably 1 mol. % Or more, more preferably 10 mol% or more, further preferably 15 mol% or more, and preferably 60 mol% or less, more preferably 40 mol% or less, still more preferably 30 mol% or less. If it exists in this range, since it is excellent in melt viscosity at the time of applying as a solar cell sealing material, a mechanical characteristic, economical efficiency, etc., it is preferable.

  The cyclic olefin polymer used in the present invention is a ring-opening polymer comprising one or more cyclic olefin components selected from the cyclic olefins represented by the general formula (1) according to the configuration (B) or a hydride thereof. Can also be used. The cyclic olefin ring-opened polymer is more stable to heat by hydrogenating a double bond in the ring, and heat molding such as sheeting by an extruder is facilitated. Further, by adding a bulky functional group (for example, cyclohexane) to the side chain, it becomes amorphous and exhibits physical properties such as transparency.

  Furthermore, as the cyclic olefin polymer used in the present invention, the mixture according to (C), that is, (A) the cyclic olefin random copolymer, and (B) the cyclic represented by the general formula (1) A mixture obtained by mixing a ring-opening polymer comprising one or more cyclic olefin components selected from olefins or a hydride thereof can be used. In this case, the mixing mass ratio of the cyclic olefin random copolymer and the cyclic olefin ring-opening polymer or a hydride thereof is not particularly limited.

  The method for producing the cyclic olefin polymer is not particularly limited. For example, JP-A-60-168708, JP-A-612012016, JP-A-61-115912, Known in JP-A-61-115916, JP-A-61-271308, JP-A-61-272216, JP-A-62-252406, JP-A-62-2252407, etc. It can be produced according to the method.

(Resin composition containing cyclic olefin polymer)
Next, in the present invention, it is important that the melt viscosity at 150 ° C. of the resin composition containing the cyclic olefin polymer is 2000 Pa · s or more and less than 15000 Pa · s. Here, the melt viscosity is a value measured by the following method. That is, using a rheometer, the melt viscosity (η *) of a sample (thickness 0.3 mm) placed on a φ18 mm parallel plate under the conditions of frequency: 1 Hz, strain: 0.5%, temperature drop rate: 3 ° C./min. ) Is measured from 230 ° C. to 120 ° C., and the melt viscosity at 150 ° C. can be determined from the obtained data.

  If the melt viscosity at 150 ° C. of the resin composition containing the cyclic olefin polymer is within the above range, the details of the photovoltaic device are usually used at the sealing pressure, that is, the atmospheric pressure (about 0.1 MPa). It is preferable because the resin can be sufficiently sealed up and sealed, and problems such as the resin flowing out to the periphery of the module hardly occur in the sealing step, and a good solar cell module can be obtained.

  From the above viewpoint, the melt viscosity at 150 ° C. of the resin composition containing the cyclic olefin polymer used in the present invention is preferably 3000 Pa · s or more, more preferably 4000 Pa · s or more, and preferably 14000 Pa. · Less than s, more preferably less than 13000 Pa · s.

  The melt viscosity is strongly influenced by the molecular weight and branched structure of the resin composition used. That is, taking the molecular weight as an example, the higher the molecular weight, the higher the melt viscosity, and conversely, the lower the molecular weight, the lower the melt viscosity. As the resin of the resin composition, a resin within the above-described melt viscosity range may be used, and it may be used alone or in combination of two or more. However, the number of commercially available grades of cyclic olefin polymers is limited industrially, and a grade having a desired molecular weight, in other words, a desired melt viscosity is not always available. Therefore, in the present invention, two or more kinds of cyclic olefin polymers having different melt viscosities can be mixed and used within the range of the melt viscosity. For example, as shown in the Examples, a mixture prepared by mixing a cyclic olefin polymer having a melt viscosity at 150 ° C. outside the range specified in the present invention so as to obtain a desired melt viscosity can also be used. Specifically, a cyclic olefin polymer having a lower melt viscosity is mixed with a cyclic olefin polymer having a melt viscosity at 150 ° C. of 15000 Pa · s or more, and a resin composition within the range specified in the present invention is obtained. Obtainable. If a cyclic olefin polymer having a melt viscosity at 150 ° C. of 17000 Pa · s and a cyclic olefin polymer having a melt viscosity at 150 ° C. of 100 Pa · s or less are used, the mass percentage in the former resin composition Is preferably 99 to 55% by mass, and more preferably 95 to 60% by mass.

  Moreover, various additives can be added to the resin composition containing a cyclic olefin polymer, if necessary. Examples of the additive include a silane coupling agent, an antioxidant, an ultraviolet absorber, a weathering stabilizer, a light diffusing agent, a nucleating agent, a pigment, a flame retardant, and a discoloration preventing agent. In the present invention, it is preferable that at least one additive selected from a silane coupling agent, an antioxidant, an ultraviolet absorber, and a weathering stabilizer is added. Further, in the present invention, it is not necessary to add a crosslinking agent or a crosslinking aid to the resin composition, but this does not exclude the addition. For example, when high heat resistance is required, the crosslinking agent And / or a crosslinking aid may be blended.

  Silane coupling agents are useful for improving the adhesion to sealing materials such as protective materials (glass, resin front sheets, back sheets, etc.) and photovoltaic elements, such as vinyl groups, Examples thereof include compounds having a hydrolyzable group such as an alkoxy group together with an unsaturated group such as an acryloxy group and a methacryloxy group, an amino group, and an epoxy group. Specific examples of the silane coupling agent include γ-glycidoxypropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and γ-glycidoxy. Examples thereof include propyltrimethoxysilane and γ-methacryloxypropyltrimethoxysilane. In the present invention, γ-glycidoxypropyltrimethoxysilane and γ-methacryloxypropyltrimethoxysilane are preferably used because of good adhesiveness and little discoloration such as yellowing. The addition amount of the silane coupling agent is usually 0.1% by mass or more, preferably 0.2% by mass or more, and usually 5% by mass or less, preferably 3% by mass with respect to 100% by mass of the resin composition. % Or less should be added. In addition, similar to the silane coupling agent, a coupling agent such as an organic titanate compound can be effectively used.

  As the antioxidant, various commercially available products can be applied, and examples thereof include various types such as monophenol-based, bisphenol-based, polymer phenol-based, sulfur-based, and phosphite-based. Examples of monophenols include 2,6-di-tert-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-tert-butyl-4-ethylphenol, and the like. Examples of bisphenols include 2,2′-methylene-bis (4-methyl-6-tert-butylphenol), 2,2′-methylene-bis- (4-ethyl-6-tert-butylphenol), 4,4 ′. -Thiobis- (3-methyl-6-tert-butylphenol), 4,4'-butylidene-bis- (3-methyl-6-tert-butylphenol), 3,9-bis [{1,1-dimethyl-2 -{Β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl} 2,4,9,10-tetraoxaspiro] 5,5-undecane.

  Examples of the high molecular phenolic group include 1,1,3-tris- (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl 2,4,6-tris (3, 5-di-tert-butyl-4-bidoxybenzyl) benzene, tetrakis- {methylene-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate} methane, bis {( 3,3′-bis-4′-hydroxy-3′tert-butylphenyl) butyric acid} glycol ester, 1,3,5-tris (3 ′, 5′-di-tert-butyl-4′-hydroxy Benzyl) -s-triazine-2,4,6- (1H, 3H, 5H) trione, triphenol (vitamin E) and the like.

  Examples of sulfur-based compounds include dilauroyl thiodipropionate, dirimyristyl thiodipropionate, and distearyl thiopropionate.

  Examples of the phosphite system include triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, 4,4′-butylidene-bis- (3-methyl-6-tert-butylphenyl-di-tridecyl) phosphite, Cyclic neopentanetetrayl bis (octadecyl phosphite), tris (mono and / or di) phenyl phosphite, diisodecyl pentaerythritol diphosphite, 9,10-dihydro-9-oxa-10-phosphaphenathlene-10 -Oxide, 10- (3,5-di-tert-butyl-4-hydroxybenzyl) -9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-decyloxy-9, 10-dihydro-9-oxa-10-phos Phenanthrene, cyclic neopentanetetraylbis (2,4-di-tert-butylphenyl) phosphite, cyclic neopentanetetraylbis (2,6-di-tert-methylphenyl) phosphite, 2,2- And methylene bis (4,6-tert-butylphenyl) octyl phosphite. In the present invention, phenol-based and phosphite-based antioxidants are preferably used in view of the effect of the antioxidant, thermal stability, economy and the like, and it is more preferable to use both in combination. The addition amount of the antioxidant is usually 0.1% by mass or more, preferably 0.2% by mass or more, and usually 1% by mass or less, preferably 0.5% with respect to 100% by mass of the resin composition. It is preferable to add less than mass%.

  As the ultraviolet absorber, various commercially available products can be applied, and various types such as benzophenone, benzotriazole, triazine, and salicylic acid ester can be exemplified. Examples of the benzophenone-based UV absorber include 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2′-carboxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-n. -Dodecyloxybenzophenone, 2-hydroxy-4-n-octadecyloxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, 2-hydroxy-5-chlorobenzophenone, 2 , 4-dihydroxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, etc. It is possible.

  The benzotriazole ultraviolet absorber is a hydroxyphenyl-substituted benzotriazole compound, for example, 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-5-t-butylphenyl) Benzotriazole, 2- (2-hydroxy-3,5-dimethylphenyl) benzotriazole, 2- (2-methyl-4-hydroxyphenyl) benzotriazole, 2- (2-hydroxy-3-methyl-5-t- Butylphenyl) benzotriazole, 2- (2-hydroxy-3,5-di-t-amylphenyl) benzotriazole, 2- (2-hydroxy-3,5-di-t-butylphenyl) benzotriazole, etc. be able to. Examples of triazine ultraviolet absorbers include 2- [4,6-bis (2,4-dimethylphenyl) -1,3,5-triazin-2-yl] -5- (octyloxy) phenol, 2- ( And 4,6-diphenyl-1,3,5-triazin-2-yl) -5- (hexyloxy) phenol. Examples of salicylic acid esters include phenyl salicylate and p-octylphenyl salicylate. The addition amount of the ultraviolet absorber is usually 0.01% by mass or more, preferably 0.05% by mass or more, and usually 2.0% by mass or less, preferably 0% with respect to 100% by mass of the resin composition. It is preferable to add 5% by mass or less.

  A hindered amine light stabilizer is suitably used as a weather stabilizer that imparts weather resistance in addition to the above ultraviolet absorber. The hindered amine light stabilizer does not absorb ultraviolet rays like the ultraviolet absorber, but exhibits a remarkable synergistic effect when used together with the ultraviolet absorber. Some of them function as a light stabilizer other than the hindered amine type, but they are often colored and are not preferable for a solar cell encapsulant / surface protective material laminate.

  Examples of hindered amine light stabilizers include dimethyl succinate-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate, poly [{6- (1,1 , 3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {{2, 2,6,6-tetramethyl-4-piperidyl} imino}], N, N′-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl-N- (1,2,2, 6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate, bis (2,2,6,6-tetramethyl-4-piperidyl) separate, 2- (3 , 5-Di-tert-4- Mud alkoxybenzylacetic) -2-n-butyl malonic acid bis (1,2,2,6,6-pentamethyl-4-piperidyl) and the like. The amount of the hindered amine light stabilizer added is usually 0.01% by mass or more, preferably 0.05% by mass or more, and usually 0.5% by mass or less, based on 100% by mass of the resin composition. Preferably 0.3 mass% or less is added.

(Cyclic olefin sealing material)
The water vapor permeability of the cyclic olefin encapsulant of the present invention is such that, for example, in the case of a solar cell module using a photovoltaic device using crystalline silicon, the photovoltaic device uses a generator element that does not deteriorate due to moisture. May not be very important, for example, in the case of a solar cell module using a photovoltaic power generation element whose power generation efficiency or durability is easily affected by moisture, such as a CIGS photovoltaic power generation element or an organic power generation element, For example 40 ° C., water vapor permeability at 90% humidity is preferably at most 1g / (m ² · day), and more preferably 0.6g / (m ² · day) or less. Here, the most commonly used EVA (ethylene / vinyl acetate copolymer) is about 25 to 35 g / (m ² · day), and the ethylene-α-olefin copolymer is 3 to 5 g / (m ^2).・ Day).
In addition, adjustment of the water vapor transmission rate of the said cyclic olefin sealing material can be performed with the cyclic olefin content, sealing material thickness, etc. FIG.

  The thickness of the cyclic olefin sealing material is preferably 12 to 700 μm, more preferably 25 to 500 μm, from the viewpoint of obtaining high moisture resistance. In the present invention, the cyclic olefin sealing material has a visible light transmittance of 85% or more, preferably 90% or more, particularly preferably 92% or more, and has a property of transmitting incident sunlight. Is desirable.

[(2) Surface protective material]
(Plastic film with a melting point of 180 ° C or less)
The surface protective material in the present invention can be made of a plastic film having a melting point of 180 ° C. or lower.
The plastic film having a melting point of 180 ° C. or lower may be composed of a single layer made of a plastic film of 180 ° C. or lower, but may be composed of two or more plastic films. The plastic film having two or more layers is a plastic film of which at least one layer is 180 ° C. or lower, but all the layers can be plastic films of 180 ° C. or lower. This is because, conventionally, a surface protection material or a cross-linking type sealing material, which has a large shrinkage in vacuum lamination, is used. Therefore, if the surface protection material does not have a high melting point intermediate film, the sealing material / surface protection material laminate is The surface protective material of the present invention is easily deformed and has a tendency to cause defects such as wrinkles and protrusions. Due to the lamination, it is difficult to cause defects such as wrinkles and protrusions on the appearance. Therefore, in the present invention, a high melting point intermediate film that resists shrinkage of the sealing material is not necessarily required.

The surface protective material in the present invention can have an intermediate film as required, such as a weather-resistant film, a moisture-proof film, and a sealing material adhesion film. In particular, from the viewpoint of obtaining high moisture resistance, it is preferable that the substrate film includes a moisture-proof film having an inorganic thin film layer. When it has a moisture-proof film, it is more preferable to have a weather-resistant film, a sealing material adhesion film, etc. as the plastic film having a melting point of 180 ° C. or lower. As described above, in the present invention, in addition to the fact that a high melting point intermediate film is not necessarily required, it is possible to propagate stress to the inorganic thin film layer during vacuum lamination by having the high melting point as a plastic film having a melting point of 180 ° C. or lower. This is because the deterioration of moisture resistance is difficult to occur.
The surface protective material in the present invention can also have other intermediate layers, and optionally includes a plastic film having a melting point higher than 180 ° C., such as a high melting point intermediate film having a melting point higher than 180 ° C., Even if a plastic film having a melting point higher than 180 ° C. such as a high melting point intermediate film having a melting point higher than 180 ° C. is not included, the effect of the present invention, that is, the surface protective material or the like can be prevented from wrinkling.

  From the above, the solar cell encapsulant / surface protective material laminate of the present invention has a configuration in which the cyclic olefin encapsulant is laminated on the plastic film side of the surface protective material having a melting point of 180 ° C. or lower. Specifically, it is preferable to have a configuration in which a weather resistant film, a moisture-proof film, a sealing material adhesion film, and the cyclic olefin sealing material are laminated in this order from the exposed side.

In the case of having a moisture-proof film, the surface protective material is obtained by laminating a weather-resistant film excellent in hydrolysis resistance and weather resistance with a melting point of 180 ° C. or less and the inorganic vapor deposition layer side of the moisture-proof film using an adhesive. What laminated | stacked the said sealing material adhesion film on the moisture-proof film using the adhesive agent is preferable. In order to improve the adhesion between the layers, a corona treatment or an anchor coat layer may be provided on the weather resistant film or moisture-proof film substrate side.
As the adhesive that can be used, a polyurethane-based adhesive is preferably used. Specific examples of the main agent of the adhesive include polycarbonate polyols, polyether polyols, acrylic polyols, polyurethane polyols, and polyester polyol-containing compositions. From the viewpoints of thermal stability, humidity stability, etc., those containing at least one of polycarbonate polyol, polyether polyol, and polyurethane polyol are more preferable.
The thickness of the surface protective material is preferably 170 to 400 μm, more preferably 230 to 300 μm, from the viewpoint of ensuring partial discharge.
Hereinafter, each constituent layer will be described.

(Weather-resistant film)
As the weather resistant film, a film excellent in hydrolysis resistance and weather resistance can be used without particular limitation, and a fluororesin film is preferably used. For example, polytetrafluoroethylene (PTFE), 4-fluoroethylene-par Chloroalkoxy copolymer (PFA), 4-fluorinated ethylene-6-fluorinated propylene copolymer (FEP), 2-ethylene-4-fluorinated ethylene copolymer (ETFE), poly-3-fluoroethylene chloride (PCTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), and the like. In the vacuum lamination process, in order to reduce the residual strain in the weather resistant film produced in the lamination process for producing the surface protective material, and to obtain the effect of reducing the residual stress in the surface protective material layer at high temperature and high humidity, It is desirable to use a film having a melting point near the temperature at the time of vacuum lamination, that is, a film of 180 ° C. or lower. In addition, by using a weather resistant film having the melting point within the above temperature range, the temperature in the vacuum lamination, the molecules in the film generated by the history of the force applied in the previous process and the thermal history, crystal orientation And the residual strain can be reduced.
From the above viewpoint, as the weather resistant film, polyvinylidene fluoride (PVDF) and polyvinyl fluoride (PVF) are preferable among the fluororesins, but in the surface protective material of the present invention which does not need to have a high melting point intermediate film. In the present invention, the deformation and the appearance decrease occur in the vacuum lamination process. However, in the present invention, the above problem is solved by laminating with the above-mentioned cyclic olefin sealing material which is not accompanied by crosslinking and has a low shrinkage and excellent sealing ability. Can do.

In addition, as the weather resistant film, it is preferable that the change in characteristics is small even in temperature / humidity changes during vacuum lamination or high temperature and high humidity, and therefore, a film that has been subjected to low shrinkage by heat treatment or the like is preferable. used.
The thickness of the weather-resistant film is generally about 20 to 200 μm, preferably 20 to 100 μm, more preferably 20 to 50 μm from the viewpoint of film handling and cost.

(Dampproof film)
The moisture-proof film in the surface protective material in the present invention is a film having moisture-proof and transparency, and is a film having at least one inorganic thin film layer made of an inorganic oxide on at least one surface of a base film.
By this inorganic thin film layer, the inner surface side of the solar cell by moisture and water permeation can be protected, and improvement in power generation efficiency can be achieved by ensuring high transparency.

  The substrate having the inorganic thin film layer is preferably a transparent thermoplastic polymer film, and any material can be used as long as it is a resin that can be used for ordinary packaging materials. Specifically, polyolefins such as homopolymers or copolymers such as ethylene, propylene and butene, amorphous polyolefins such as cyclic polyolefins, polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), nylon 6 , Nylon 66, nylon 12, polyamide such as copolymer nylon, ethylene-vinyl acetate copolymer partial hydrolyzate (EVOH), polyimide, polyetherimide, polysulfone, polyethersulfone, polyetheretherketone, polycarbonate, polyvinyl Examples include butyral, polyarylate, fluororesin, acrylate resin, and biodegradable resin. Among these, polyesters, polyamides, and polyolefins are preferable from the viewpoints of film properties and cost. Among these, polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) are particularly preferable from the viewpoint of film properties.

In addition, the base material is a known additive such as an antistatic agent, a light blocking agent, an ultraviolet absorber, a plasticizer, a lubricant, a filler, a colorant, a stabilizer, a lubricant, a crosslinking agent, an antiblocking agent, an oxidation agent. An inhibitor or the like can be contained.
The thermoplastic polymer film as the substrate is formed by using the above raw materials, but when used as a substrate, it may be unstretched or stretched. . Moreover, you may laminate | stack with the other plastic base material.

  Such a substrate can be produced by a conventionally known method. For example, a raw material resin is melted by an extruder, extruded by an annular die or a T die, and rapidly cooled to be substantially amorphous and not oriented. An unstretched film can be manufactured. Further, by using a multilayer die, it is possible to produce a single layer film made of one kind of resin, a multilayer film made of one kind of resin, a multilayer film made of various kinds of resins, and the like.

  The unstretched film is subjected to a known method such as uniaxial stretching, tenter sequential biaxial stretching, tenter simultaneous biaxial stretching, tubular simultaneous biaxial stretching, or the like. A film stretched in at least a uniaxial direction can be produced by stretching in a direction (horizontal axis) perpendicular thereto. Although a draw ratio can be set arbitrarily, it is preferable that 150 degreeC heat shrink rate is 0.01 to 5%, Furthermore, it is preferable that it is 0.01 to 2%. Among these, from the viewpoint of film properties, a biaxially stretched polyethylene naphthalate film, a polyethylene terephthalate and / or a coextruded biaxially stretched film of polyethylene naphthalate and other plastics are preferable.

  In addition, it is preferable to apply | coat an anchor coat agent and to provide an anchor coat layer in the said base material for the adhesive improvement with an inorganic thin film. As anchor coating agents, solvent-based or water-soluble polyester resins, isocyanate resins, urethane resins, acrylic resins, vinyl-modified resins, vinyl alcohol resins, vinyl butyral resins, ethylene vinyl alcohol resins, nitrocellulose resins, oxazoline group-containing resins, carbodiimides A group-containing resin, a methylene group-containing resin, an epoxy group-containing resin, a modified styrene resin, a modified silicone resin, an alkyl titanate, or the like can be used alone or in combination of two or more. Also contains silane coupling agents, titanium coupling agents, light blocking agents, ultraviolet absorbers, stabilizers, lubricants, antiblocking agents, antioxidants, etc., or they are copolymerized with the above resins Things can be used.

  As a method for forming the anchor coat layer, a known coating method is appropriately adopted. For example, any method such as a reverse roll coater, a gravure coater, a rod coater, an air doctor coater, a spray or a coating method using a brush can be used. Alternatively, the substrate may be immersed in a resin solution. After application, the solvent can be evaporated using a known drying method such as hot drying such as hot air drying or hot roll drying at a temperature of about 80 to 200 ° C., or infrared drying. Moreover, in order to improve water resistance and durability, the crosslinking process by electron beam irradiation can also be performed. Further, the formation of the anchor coat layer may be a method performed in the middle of the substrate film production line (inline) or a method performed after the substrate film is manufactured (offline).

As the moisture-proof film, a film in which a metal coating film such as aluminum is formed on the transparent base film can also be used. An inorganic oxide coating film is preferably used.
As the method for forming the inorganic thin film layer, any method such as a vapor deposition method and a coating method can be used, but the vapor deposition method is preferable in that a uniform thin film having a high gas barrier property can be obtained. This vapor deposition method includes methods such as physical vapor deposition (PVD) or chemical vapor deposition (CVD). Examples of physical vapor deposition include vacuum deposition, ion plating, and sputtering. Examples of chemical vapor deposition include plasma CVD using plasma and a catalyst that thermally decomposes a material gas using a heated catalyst. Examples include chemical vapor deposition (Cat-CVD).

  Examples of the inorganic substance constituting the inorganic oxide coating film include silicon, aluminum, magnesium, zinc, tin, nickel, titanium, hydrogenated carbon, and the like, or oxides, carbides, nitrides, or mixtures thereof. Of these, diamond like carbon mainly composed of silicon oxide, aluminum oxide, and hydrogenated carbon is preferable. In particular, silicon oxide, silicon nitride, silicon oxynitride, and aluminum oxide are preferable in that high gas barrier properties can be stably maintained.

  The thickness of the inorganic thin film layer is preferably 40 to 1000 nm, more preferably 40 to 800 nm, and still more preferably 40 to 600 nm, from the viewpoint of high moisture resistance and transparency. Moreover, generally the thickness of the said base film is about 5-100 micrometers, 8-50 micrometers is preferable from the point of productivity or handleability, and 12-25 micrometers is still more preferable. Therefore, the thickness of the moisture-proof film is generally about 6 to 100 μm, preferably 9 to 50 μm, more preferably 12 to 25 μm from the viewpoint of productivity and ease of handling.

(Sealing material adhesion film)
The sealing material contact | adherence film in this invention is a film bonded preferably to the back side of the said moisture-proof film via an adhesive agent. That is, the sealing material adhesion film has a melting point of 180 ° C. or lower, and preferably has a melting point of 180 ° C. or lower and a melting point of 180 ° C. or lower, containing at least one selected from polyolefin resins and fluororesins. It consists of at least one layer selected from these fluorine-based resin layers.
In the present invention, when the melting point of the sealing material adhesion film is 180 ° C. or less, the residual strain in the weather resistant film generated in the lamination process for producing the surface protective material is reduced in the vacuum lamination process, and the high temperature and high humidity is reduced. From this point of view, the melting point of the sealing material adhesion film is preferably 180 ° C. or less, and preferably 175 ° C. or less. It is more preferable that it is 170 degrees C or less. On the other hand, the melting point is preferably 100 ° C. or higher from the viewpoint of ensuring heat resistance.
As the sealing material adhesion film, it is desirable that the melting point thereof is in the vicinity of the vacuum lamination temperature as described above for the same reason as the weather resistant film, for example, polyethylene (PE), polypropylene (PP), polylactic acid (PLA), Those obtained by forming a film of a resin composition in which an ultraviolet absorber or a colorant is kneaded into a resin such as polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), or cellulose butyrate (CAB) are preferably used. It is not limited.

  From the viewpoint of improving the adhesion to the cyclic olefin encapsulant in vacuum lamination, polyethylene (PE) and polypropylene (PP) are preferable as the encapsulant adhesion film, and the surface protective material has partial discharge resistance characteristics. Polypropylene (PP) is particularly preferable because the sealing material adhesion film is thick.

In addition, as said ultraviolet absorber, the thing similar to the ultraviolet absorber used for the above-mentioned cyclic olefin sealing material can be used. Moreover, titanium oxide, calcium carbonate, etc. can be used as a coloring agent.
The thickness of the sealing material adhesion film is generally about 25 to 300 μm, preferably 50 to 300 μm, more preferably 50 to 250 μm, further from the viewpoint of ensuring partial discharge of the protective material, from the viewpoint of film handling and cost. Preferably it is 120-200 micrometers.
Further, the surface protective material in the present invention is used as a back surface protective material from the front surface protective material because it can prevent appearance defects such as wrinkles in a heating process such as vacuum lamination and can obtain high moisture resistance. Is more preferable.

(Sealing material / surface protective material laminate)
The solar cell sealing material / surface protective material laminate of the present invention comprises the cyclic olefin sealing material and the surface protective material.
In the present invention, since the surface protective material does not need to include the high melting point intermediate film layer in the dry lamination process for producing the surface protective material, the amount of the solvent used can be reduced. That is, in the present invention, from the viewpoint of reducing the amount of solvent used, it is preferable that the surface protective material does not contain a high melting point intermediate film, but the inclusion of this is optional. On the other hand, by laminating the surface protective material and a non-crosslinked, low-shrinkage cyclic olefin sealing material with excellent sealing properties, the appearance of deformation, wrinkles, protrusions, etc. of the sealing material / surface protective material laminate during vacuum lamination Sealing material / surface with excellent environmental load, appearance, and moisture resistance that can prevent the occurrence of defects and has achieved high moisture resistance as a laminate by lamination with moisture-proof cyclic olefin sealing material A protective material laminate is obtained.
The solar cell encapsulant / surface protective material laminate of the present invention is generally about 0.40 to 2.3 mm, preferably 0.5 to 1.6 mm, from the viewpoint of fixing and protecting the solar cell element. More preferably, it is used in the form of a sheet of about 0.60 to 1.0 mm.

<Solar cell module, solar cell>
In order to manufacture the solar cell module and / or solar cell of the present invention using such a solar cell encapsulant / surface protective material laminate, the present invention can be used instead of the conventional encapsulant and surface protective material. What is necessary is just to produce by the well-known method using the sealing material and surface protection material laminated body for solar cells.

  As such a solar cell module, various types can be exemplified, for example, a front protective material, a front sealing material, a solar cell element, and a solar cell sealing material / surface protective material of the present invention. The solar cell module produced using the laminate is specifically mentioned. Specifically, the solar cell front surface protective material / sealing material / solar cell element / the solar cell sealing material / surface protective material laminate of the present invention. Mention may be made of body structures.

  As the solar cell element, for example, a single crystal silicon type, a polycrystalline silicon type, an amorphous silicon type, a gallium-arsenic, a copper-indium-selenium, a cadmium-tellurium, or the like III-V group or II-VI group compound semiconductor type, Examples include a dye sensitizing type and an organic thin film type.

  About each member which comprises the solar cell module produced using the sealing material and surface protection material laminated body for solar cells of this invention, although it does not specifically limit, As a front surface protection material, metal and various Single layer or multilayer sheet such as thermoplastic resin film, for example, metal such as tin, aluminum, stainless steel, inorganic material such as glass, polyester, inorganic deposited polyester, fluorine-containing resin, single layer or multilayer such as polyolefin A protective material can be mentioned. The surface of the front protective material can be subjected to a known surface treatment such as a primer treatment or a corona treatment in order to improve the adhesion to the sealing material or other members.

  The solar cell module and / or solar cell of the present invention comprises a front surface protective material, a sealing material, a power generation element, and a sealing material / surface protective material laminate of the present invention at a temperature of 120 to 150 ° C. using a vacuum laminator according to a conventional method. It can be easily manufactured by heat-pressure bonding with a degassing time of 2 to 15 minutes, a pressing pressure of 0.5 to 1 atm, and a pressing time of 8 to 45 minutes.

  As a manufacturing method of the solar cell module, a known manufacturing method can be applied, and is not particularly limited. Generally, the front protective sheet, the sealing resin layer, the solar cell element, and the sealing material of the present invention are used. -It has the process of laminating | stacking in order of a surface protection material laminated body, and the process of vacuum-sucking them and carrying out thermocompression bonding. Also, batch type manufacturing equipment, roll-to-roll type manufacturing equipment, and the like can be applied.

  The solar cell module produced using the sealing material / surface protective material laminate of the present invention has a configuration such as a front protective sheet / solar cell element / sealing material / surface protective material laminate of the present invention described above. An example will be described. A front protective sheet, a sealing material, a solar cell element, and a sealing material / surface protective material laminate of the present invention are laminated in this order from the sunlight receiving side, and a junction box (solar cell element) is further formed on the lower surface of the back sheet. A terminal box for connecting wiring for taking out the electricity generated from the outside is bonded. The solar cell elements are connected by wiring in order to conduct the generated current to the outside. The wiring is taken out through a through hole provided in the backsheet and connected to the junction box.

  EXAMPLES The present invention will be described more specifically with reference to examples. However, the present invention is not limited by these examples and comparative examples. Various physical properties were measured and evaluated as follows.

(Physical property measurement)
(1) Moisture-proof performance For moisture-proof film and cyclic olefin encapsulant, after preparation of moisture-proof film and cyclic olefin encapsulant, after storage at 40 ° C for one week, and for sealant / surface protective material laminate The moisture-proof performance of the laminate obtained by pasting and curing by dry lamination is the same as that of JIS Z 0222 “Moisture permeability test method for moisture-proof packaging containers” and JIS Z 0208 “Moisture permeability test method for moisture-proof packaging materials (cup method)” In accordance with various conditions, the following method was used for evaluation.
Two sample films each having a moisture permeable area of 10.0 cm × 10.0 cm square are used (in the case of a sealing material / surface protective material laminate including a moisture proof film and a moisture proof film, the inorganic vapor deposition surface is on the outside), A bag with about 20 g of anhydrous calcium chloride as a hygroscopic agent and four sides sealed is prepared, and the bag is placed in a constant temperature and humidity device with a temperature of 40 ° C. and a relative humidity of 90%, and mass measurement is performed at intervals of 72 hours or more until approximately 200 days. The water vapor transmission rate (g / m ² · day) was calculated from the slope of the regression line between the elapsed time from the fourth day and the bag weight.

(2) Fluidity at the time of sealing (melt viscosity)
Using a rheometer (Rheology, model: rheometer MR-300T), a cyclic olefin placed on a φ18 mm parallel plate under the conditions of frequency: 1 Hz, strain: 0.5%, temperature drop rate: 3 ° C./min. Obtained by measuring the temperature dispersion of the melt viscosity (η *) of the sealing material (thickness 0.3 mm), EVA (thickness 0.3 mm), and EVA sealing material (thickness 0.5 mm) from 230 ° C. to 120 ° C. The melt viscosity at 150 ° C. was determined from the obtained data.

(3) Melting point Using a differential scanning calorimeter, according to JIS K7121, about 10 mg of a film sample was heated from −40 ° C. to 200 ° C. at a heating rate of 10 ° C./min, and a melting peak was confirmed. After holding for a minute, the temperature was lowered to −40 ° C. at a cooling rate of 10 ° C./min, and again from the thermogram measured when the temperature was raised to 200 ° C. at a heating rate of 10 ° C./min. Let (Tm) (° C.) be the melting point. In addition, when melting | fusing point exceeded 200 degreeC, such as polyester, and a melting peak was not observed, the temperature rising upper limit temperature was set to 300 degreeC, and the same measurement was performed after that.

(4) Sealability Solar cell sandwiched between two sheet-like sealing material / surface protective material laminates having a thickness of 0.5 mm between two sheets of white glass (size: 150 mm × 150 mm) having a thickness of 3 mm. A cell (manufactured by France Photowatt Co., Ltd., trade name: 101 × 101MM) was placed, and this was used at 150 ° C., 30 using a vacuum laminator (trade name: LM30 × 30, manufactured by NPC Corporation). Samples were laminated and pressed under conditions of 0.1 MPa and pressure of 0.1 MPa, the appearance was observed, and evaluated according to the following evaluation criteria.
(○) When the sealing resin sufficiently wraps around the solar cell and there is no resin omission and a good solar cell module is obtained (×) The sealing resin does not wrap around the solar cell and seals Is insufficient, or the sealing resin flows out from the periphery of the glass and the thickness of the sealing resin between the glass plate and the solar battery cell is very thin (0.05 mm or less)

(5) Appearance determination after vacuum lamination White plate glass (size: 150 mm x 150 mm) with a thickness of 3 mm and a sealing material / surface protective material laminate are sequentially laminated, and this is laminated with a vacuum laminator (manufactured by NPC Corporation). , Trade name: LM30 × 30), a sample that was laminated and pressed under the conditions of 150 ° C., 15 minutes, and a pressure of 0.1 MPa was observed, and its appearance was observed and evaluated according to the following evaluation criteria.
(○) When a good solar cell module without wrinkles on the surface protective material surface is obtained (×) When wrinkles are seen on the surface protective material surface

(Structure film)
<Weather-resistant film>
A polyvinylidene fluoride (PVDF) film manufactured by Arkema Co., Ltd., trade name: Kynar 302-PGM-TR (thickness: 30 μm) was used.

<Adhesive coating solution>
Made by Mitsui Chemicals Polyurethanes Co., Ltd., trade name: A1102, Mitsui Chemicals Polyurethanes Co., Ltd. A3070 is used as a curing agent containing an aliphatic hexamethylene diisocyanate component, and mixed so that the mass ratio is 16: 1. Then, an adhesive coating solution was prepared by diluting with ethyl acetate so that the solid content concentration was 30% by mass.

<Sealing material adhesion film>
To isotactic polypropylene resin, titanium oxide (8% by mass) as a whitening agent and ultrafine titanium oxide (particle diameter, 0.01 to 0.06 μm, 3% by mass) as an ultraviolet absorber are added, In addition, the necessary additives are added and sufficiently kneaded to prepare a polypropylene resin composition, and then the polypropylene resin composition is extruded with an extruder to produce unstretched polypropylene resin films having a thickness of 90 μm and 190 μm. Furthermore, a corona discharge surface was formed on one side of the unstretched polypropylene resin film by a corona discharge treatment according to a conventional method. Both the unstretched polypropylene resin films produced had a melting point of 163 ° C.

<High melting point intermediate film>
A product name: Diafoil T100 (thickness: 100 μm) manufactured by Mitsubishi Plastics Corporation having a melting point of 253 ° C. was used as the high melting point intermediate film.
<Dampproof film>
As a moisture-proof film, a product name: Tech Barrier LX manufactured by Mitsubishi Plastics Co., Ltd. in which silica was deposited on a 12 μm polyethylene terephthalate resin film was used. Moreover, the moisture-proof performance measured by the above-mentioned method was 0.20 [g / (m ² · day)].

<Cyclic olefin sealing material>
Cyclic olefin sealing material C-1
As the cyclic olefin polymer, ethylene-norbornene random copolymer (manufactured by Polyplastics Co., Ltd., trade name: TOPAS 9506X1, melt viscosity at 150 ° C .: 16600 Pa · s, norbornene content: 22 mol%, hereinafter P 80% by mass) and P-1 is an ethylene-norbornene random copolymer (manufactured by Polyplastics Co., Ltd., trade name: TOPAS TM, melt viscosity at 150 ° C .: 100 Pa) · S or less, norbornene content: 28 mol%, hereinafter abbreviated as P-2) was mixed in advance with a twin screw extruder, and then a 32 mm single screw extruder equipped with a T die Is melt-kneaded at a set temperature of 260 ° C., and is rapidly cooled with a 20 ° C. cast roll to form a thickness of 0.3 mm, To obtain a sheet-shaped flexible sheet D-1 of .5mm. Moreover, the moisture-proof performance measured by the above-mentioned method was 0.50 [g / (m ² · day)].

Cyclic olefin sealing material C-2
In the cyclic olefin sealing material C-1, except that the ethylene-norbornene random copolymer (P-1) is changed to a resin composition of 100% by mass, the thickness is the same as that of the cyclic olefin sealing material C-1. Of 0.3-mm and 0.5-mm sheet-like cyclic olefin sealing material C-2 was obtained. Moreover, the moisture-proof performance measured by the above-mentioned method was 0.50 [g / (m ² · day)].

<EVA film>
100 parts by mass of ethylene-vinyl acetate copolymer (Mitsui / DuPont Polychemical Co., Ltd., trade name: EVAFLEX EV150, vinyl acetate content: 33% by mass, hereinafter abbreviated as EVA) and peroxide crosslinking 32 mm single-screw extrusion provided with a T-die with a resin composition consisting of 1.25 parts by weight of the agent 1,1-di (t-butylperoxy) cyclohexane (trade name Luperox 331, manufactured by Arkema Yoshiaki Co., Ltd.) A sheet having a thickness of 0.3 mm (for melt viscosity measurement) and 0.5 mm was obtained by melt-kneading at a set temperature of 95 ° C. using a machine and quench-casting with a 20 ° C. cast roll.
<EVA sealing material>
The product name: EVASKY S11 (thickness: 500 μm) manufactured by Bridgestone Corporation was used as the EVA sealing material.

Example 1
The adhesive coating liquid was applied and dried on the weather resistant film so as to have a solid content of 6 g / m ^2, and bonded to the corona-treated surface of the 190 μm sealing material adhesion film by dry lamination. Thereafter, it was cured at 40 ° C. for 5 days to produce a surface protective material B-1 having a thickness of 226 μm. The amount of solvent required to use this surface protective material was 20 g / m ² .
The prepared cyclic olefin sealing material C-1 and surface protective material B-1 sealing material adhesion film side using a vacuum laminating apparatus LM-30x30 manufactured by NPC Corporation at 150 ° C. for 15 minutes Then, the sealing material surface protective layer laminate D-1 was produced by laminating in this order by a conventional method. Then, moisture resistance was measured using the produced sealing material / surface protective material laminate D-1. The results are shown in Table 2.

Example 2
The adhesive coating solution was applied and dried on a weather resistant film so as to have a solid content of 6 g / m ² , and bonded to the inorganic thin film surface of the moisture-proof film by dry lamination.
Furthermore, this adhesive coating liquid was applied and dried on the corona-treated surface of the 190 μm sealing material adhesion film so as to have a solid content of 6 g / m ^2, and was bonded by the moisture-proof film of the previous bonding film and dry lamination. Thereafter, it was cured at 40 ° C. for 5 days to produce a surface protective material B-2 having a thickness of 244 μm. The amount of solvent required to use this surface protective material was 40 g / m ² .
150 ° C. using a vacuum laminator (trade name: LM30 × 30 manufactured by NPC Corporation) on the sealing material adhesion film side of the prepared cyclic olefin sealing material-C1 and surface protective material B-2. The sealing material surface protective layer laminate D-2 was produced by laminating in this order by a conventional method under conditions of 15 minutes. Then, the moisture-proof performance was measured using the produced sealing material / surface protective material laminate D-2. The results are shown in Table 2.

Example 3
The adhesive coating liquid was applied and dried on a weather resistant film so as to have a solid content of 6 g / m ^2, and a high melting point intermediate film was bonded by dry lamination. Furthermore, this adhesive coating liquid was applied and dried on the corona-treated surface of the 90 μm sealing material adhesion film so as to have a solid content of 6 g / m ^2, and bonded to the high-melting-point intermediate film surface of the previous bonded film by dry lamination. Thereafter, it was cured at 40 ° C. for 5 days to produce a surface protective layer B-3 having a thickness of 232 μm. The amount of solvent required to use this surface protective material was 40 g / m ² .
150 ° C. using a vacuum laminator (trade name: LM30 × 30, manufactured by NPC Co., Ltd.) on the sealing material adhesion film side of the prepared cyclic olefin sealing material C-1 and surface protective material B-3. Then, the sealing material surface protective layer laminate D-3 was produced by laminating in this order by a conventional method under conditions of 15 minutes. Then, moisture-proof performance was measured using the produced sealing material / surface protective material laminate D-3. The results are shown in Table 2.

Example 4
The adhesive coating solution was applied and dried on a weather resistant film so as to have a solid content of 6 g / m ² , and bonded to the inorganic vapor-deposited surface of the moisture-proof film by dry lamination.
Furthermore, this adhesive coating liquid is applied and dried on the corona-treated surface of the high melting point intermediate film so as to have a solid content of 6 g / m ^2, and bonded with the moisture-proof film and dry laminate of the previous bonded film, and then sealed by 90 μm. The adhesive coating solution was applied and dried on the corona-treated surface of the material adhesion film so as to have a solid content of 6 g / m ^2, and bonded by dry lamination to the high melting point intermediate film surface of the previous bonded film. Thereafter, it was cured at 40 ° C. for 5 days to produce a surface protective layer B-4 having a thickness of 250 μm. The amount of solvent required to use this surface protective material was 60 g / m ² .
150 ° C. using a vacuum laminator (trade name: LM30 × 30, manufactured by NPC Co., Ltd.) on the sealing material adhesion film side of the prepared cyclic olefin sealing material C-1 and surface protective material B-4. Then, the sealing material surface protective layer laminate D-4 was produced by laminating in this order by a conventional method under conditions of 15 minutes. Then, the moisture-proof performance was measured using the produced sealing material / surface protective material laminate D-4. The results are shown in Table 2.

Comparative Example 1
The sealing material adhesion film side of the cyclic olefin sealing material C-2 and the surface protective material B-1 is 150 ° C. for 15 minutes using a vacuum laminator (trade name: LM30 × 30, manufactured by NPC Corporation). Under these conditions, the sealing material surface protective layer laminate D-5 was produced in this order by a conventional method. Then, the moisture-proof performance was measured using the produced sealing material / surface protective material laminate D-5. The results are shown in Table 2.

Comparative Example 2
The sealing material adhesion film side of the cyclic olefin sealing material C-2 and the surface protection material B-2 is 150 ° C. for 15 minutes using a vacuum laminator (trade name: LM30 × 30, manufactured by NPC Corporation). Under these conditions, the sealing material surface protective layer laminate D-6 was produced in this order by a conventional method. Then, the moisture-proof performance was measured using the produced sealing material / surface protective material laminate D-6. The results are shown in Table 2.

Comparative Example 3
The prepared EVA film and the sealing material adhesion film side of the surface protective material B-2 were used at 150 ° C. for 15 minutes using a vacuum laminator (trade name: LM30 × 30, manufactured by NPC Corporation). The sealing material protective layer laminate product D-7 was produced by laminating in this order by a conventional method. Then, the moisture-proof performance was measured using the produced sealing material / surface protective material laminate D-7. The results are shown in Table 2.

Comparative Example 4
The sealant adhesion film side of the EVA sealant and the surface protective layer B-2 was fixed at 150 ° C. for 15 minutes using a vacuum laminator (trade name: LM30 × 30, manufactured by NPC Corporation). Thus, a sealing material surface protective layer laminate D-8 was produced in this order. Then, using the produced sealing material surface protective layer laminate D-8, the moisture-proof performance was measured by the method described above. The results are shown in Table 2.

Thus, in the sealing material / surface protective material laminates of Examples 1 to 4 having the configuration of the present invention, the sealing material is made of a cyclic olefin excellent in sealing suitability with a low shrinkage rate without cross-linking. Because of the sealing material, it was difficult to be deformed without using a high melting point intermediate film, and no remarkable appearance defects such as wrinkles and protrusions were found.
On the other hand, in Comparative Examples 1 and 2 using a sealing material made of a cyclic olefin whose sealing material deviates from the melt viscosity value specified in the present invention, although the appearance defect is not seen, the sealing resin is a solar cell. Sealing was insufficient because it did not go around the periphery. Further, Comparative Example 4 using an EVA sealing material that has been conventionally used as a sealing material is excellent in sealing suitability, but the surface protective material is wrinkled and is not preferable in appearance, and uses an EVA film. Comparative Example 3 was insufficient in both sealing ability and appearance.
As mentioned above, it is preferable that the surface protection material of Examples 1-4 is used as a back surface protection material.

Claims (10)

  (1) A resin composition containing a cyclic olefin polymer, which is made of a resin composition having a melt viscosity at 150 ° C. measured at a frequency of 1 Hz of 2000 Pa · s or more and less than 15000 Pa · s, and ( 2) A solar cell sealing material / surface protective material laminate comprising a surface protective material comprising a plastic film having a melting point of 180 ° C. or lower.   The solar cell sealing material / surface protective material laminate according to claim 1, wherein the surface protective material comprises only a plastic film having a melting point of 180 ° C. or lower.   The sealing material for solar cells according to claim 1, wherein the plastic film having a melting point of 180 ° C. or lower has at least a sealing material adhesion film layer having a melting point of 180 ° C. or less and a weather resistant film layer having a melting point of 180 ° C. or less. -Surface protective material laminate.   The sealing material / surface for solar cell according to claim 1, wherein the plastic film having a melting point of 180 ° C. or less has at least a polyolefin resin layer having a melting point of 180 ° C. or less and a fluorine resin layer having a melting point of 180 ° C. or less. Protective material laminate. The sun according to any one of claims 1 to 4, wherein the cyclic olefin polymer is a cyclic olefin random copolymer composed of a linear olefin component and a cyclic olefin component represented by the following general formula (1). Battery encapsulant / surface protective material laminate.

(In the general formula (1), R _{1 to} R ₁₂ are each a hydrogen atom or a hydrocarbon group and may be the same or different. R ₅ and R ₁₀ , or R ₁₁ and R It may be integrated with ₁₂ to form a divalent hydrocarbon group, or R ₃ or R ₁₀ and R ₁₁ or R ₁₂ may form a ring with each other, n is 0 or positive When it is an integer and n is 2 or more and there are a plurality of each of R _{5 to} R ₈ , these may be the same or different. 6. The water vapor permeability at 40 ° C. and 90% RH of the encapsulating material comprising the resin composition containing the cyclic olefin polymer is 1.0 [g / m ² · day] or less. The solar cell encapsulant / surface protective material laminate described in 1.   The module for solar cells which has the sealing material and surface protection material laminated body for solar cells in any one of Claims 1-6 in which the said surface protection material contains a moisture-proof film.   The solar cell according to any one of claims 1 to 7, having a configuration in which a sealing material made of a resin composition containing the (1) cyclic olefin polymer is laminated on the plastic film side of the surface protective material. Sealing material / surface protective material laminate.   The said weather-resistant film, the said moisture-proof film, the said sealing material contact | adherence film, and the sealing material which consists of a resin composition containing the said (1) cyclic olefin type polymer are laminated | stacked in this order. The solar cell sealing material / surface protective material laminate according to any one of the above.   The module for solar cells which has the sealing material and surface protection material laminated body for solar cells in any one of Claims 1-9.