JP5673936B2 - Front sheet for solar cell module, solar cell module using the same, and method for producing front sheet for solar cell module - Google Patents

Description

  The present invention relates to a front sheet for a solar cell module, a solar cell module using the front sheet, and a method for manufacturing a front sheet for a solar cell module.

  In recent years, solar cells have attracted attention as a fossil fuel alternative energy source that leads to reduction of carbon dioxide emissions, and efforts to improve various performances such as conversion efficiency and durability of solar cells have been actively conducted.

  For the spread of solar cells, it is important to improve the durability of solar cells. As a problem that hinders the durability of the solar cell, for example, a gas such as water vapor contained in the atmosphere penetrates into the solar cell module and degrades the solar cell element. Therefore, a sealing substrate having a high gas barrier property, which is a gas blocking function such as water vapor, is disposed on the front surface side which is the light receiving surface of the solar cell element of the solar cell module and on the back surface side which is the opposite surface. .

  The front sheet for the solar cell module is a sealing substrate used on the light receiving surface side of the solar cell element of the solar cell module. Since it is necessary to maintain a good gas barrier property even in an environment exposed to light, it is common to use glass for the front sheet.

  However, in recent years, attempts have been made to use a resin film instead of glass for the front sheet from the viewpoint of weight reduction and damage prevention. For example, as a resin film used for a front sheet, a fluororesin film, an acrylic resin film, and the like have been proposed (Patent Document 1, Patent Document 2).

  However, since the gas barrier property is generally low only with the resin film, when the resin film is used for the front sheet, the gas barrier property is formed by forming an inorganic layer having an inorganic compound exhibiting the gas barrier property on the resin film. (Patent Document 1, Patent Document 2).

JP-A-4-239634 JP 2000-174298 A

  When using an inorganic layer having an inorganic compound exhibiting gas barrier properties on a solar cell module front sheet, a plurality of resin films are used, and an inorganic layer is formed between the resin films to remove the inorganic compound. It is desirable to prevent.

  In addition, a polyester resin film is generally a film that hardly shrinks by heat or light. Therefore, by forming an inorganic layer on the polyester resin film, it is possible to prevent the gas barrier property from being lowered due to cracks in the inorganic layer due to the shrinkage of the resin film due to heat or light during production or use. it can. However, when the inorganic layer is directly formed on the polyester resin film, the inorganic layer is prone to defects such as minute holes due to fine protrusions present on the surface of the polyester resin film. There is a problem that a high-quality inorganic layer cannot be obtained stably and high gas barrier properties cannot be realized. In addition, the polyester resin film has a problem of poor adhesion to an inorganic compound. Therefore, after forming an organic layer having an organic compound with good adhesion between the polyester resin and the inorganic compound on the polyester resin film to smooth the surface, an inorganic layer can be formed on the organic layer. Conceivable.

  However, in order to use it in the organic layer of the front sheet used on the light-receiving surface side of the solar cell element, in addition to the adhesion between the polyester resin and the inorganic compound, it deteriorates even in an environment exposed to light. It is necessary to be difficult.

  That is, the subject of this invention is providing the front sheet | seat for solar cell modules which has favorable gas barrier property by finding the optimal material of the organic layer of the front sheet | seat for solar cell modules. Moreover, it is providing the solar cell module using this front sheet | seat for solar cell modules. Moreover, it is providing the optimal manufacturing method which can manufacture this front sheet | seat for solar cell modules easily.

  Therefore, in the present invention, a solar cell module front sheet, a solar cell module, and a method for manufacturing a solar cell module front sheet having the following configurations are provided.

The front sheet for a solar cell module according to the first aspect of the invention includes a first transparent film made of resin and an organic layer and an inorganic layer having an inorganic compound exhibiting gas barrier properties in this order on a polyester resin base material. 2 transparent films, one surface side of the first transparent film, and the surface side having the organic layer and the inorganic layer of the second transparent film, and the first transparent film and the second transparent film. An adhesive layer for laminating an inorganic layer of the transparent film, wherein the organic layer has an acrylic resin, and the organic layer acrylic resin has a hydroxyl group. no oxyalkylene group, and viewed including the structural unit is present fluorene group, wherein the organic layer has an uneven in the vicinity of the surface of the organic layer, the inorganic layer, have the unevenness of the organic layer It is formed along the surface that, P-V value on the surface of the inorganic layer is 200nm or more, and has an uneven Ra35 is above nm, a front sheet for a solar cell module.

In the front sheet for a solar cell module according to the second invention, in the first invention, the acrylic resin of the organic layer is represented by the following general formula [1] (in the general formula [1], n ₁ and n ₂ are 0 or positive N ₁ + n ₂ is an integer of 1 to 20. R ¹ and R ² are a hydrogen atom or a methyl group, R ³ and R ⁴ are a hydrogen atom, a methyl group or an ethyl group, R ⁵ and R The solar cell module front sheet according to claim 1, wherein ⁶ is a hydrogen atom, a methyl group, or an ethyl group.

The front sheet for a solar cell module according to the third invention is the front sheet for a solar cell module according to claim ₂ , wherein n ₁ + n ₂ is 1 to 6 in the general formula [1] in the second invention. is there.

A solar cell module of a fourth invention is a solar cell module comprising a solar cell module front sheet, a solar cell element, and a solar cell module back sheet.
The front sheet for a solar cell module is the front sheet for a solar cell module according to any one of the first to third inventions, and the front sheet for the solar cell module is a surface on the second transparent film side. It is a solar cell module arrange | positioned toward the said solar cell element.

ポリエステル樹脂製の基材の両面のうち前記有機層が形成された面とは反対側の面を表面温度が０℃以下となるように冷却しながら、前記有機層上にガスバリア性を示す無機化合物を有する無機層をイオンプレーティング法によって形成する無機層形成工程を含む、第２の透明フィルムを作製する作製工程と、前記準備工程で準備した第１の透明フィルムと前記作製工程で作製した第２の透明フィルムとを、前記第１の透明フィルムのいずれか一方の面側に前記第２の透明フィルムの有機層及び無機層を有する面側を向く様にして、前記第１の透明フィルムと前記第２の透明フィルムの無機層との間に接着層を介して積層する積層工程と、を有する、太陽電池モジュール用フロントシートの製造方法である。
The manufacturing method of the solar cell module front sheet according to the fifth aspect of the present invention includes a preparation step of preparing a resin-made first transparent film and a polyester resin substrate on the following general formula [2] (general formula [2 In the formula, n ₁ and n ₂ are 0 or a positive integer, and n ₁ + n ₂ is 1 to 6. R ¹ and R ² are a hydrogen atom or a methyl group, R ³ and R ⁴ are a hydrogen atom, A methyl group or an ethyl group, and R ⁵ and R ⁶ are a hydrogen atom, a methyl group or an ethyl group.) And a composition containing a polymerization initiator and a polymerization initiator are crosslinked with ultraviolet rays to form an organic layer. Forming an organic layer, and

An inorganic compound that exhibits gas barrier properties on the organic layer while cooling the surface opposite to the surface on which the organic layer is formed on both surfaces of the polyester resin substrate so that the surface temperature is 0 ° C. or lower . Including an inorganic layer forming step of forming an inorganic layer having an ion plating method, a production step of producing a second transparent film, a first transparent film prepared in the preparation step, and a first step produced in the production step The first transparent film, the second transparent film facing the surface side having the organic layer and the inorganic layer of the second transparent film on one surface side of the first transparent film, And a lamination step of laminating with an inorganic layer of the second transparent film via an adhesive layer.

According to the solar cell module front sheet of the present invention, good gas barrier properties can be obtained.
According to the solar cell module of the present invention, a solar cell module having excellent durability can be obtained by using the solar cell module front sheet exhibiting good gas barrier properties.
According to the method for manufacturing a front sheet for a solar cell module according to the present invention, it is possible to manufacture a front sheet for a solar cell module that exhibits good gas barrier properties and high adhesion between resin films.

Sectional drawing which illustrates one form of the front sheet | seat for solar cell modules by this invention. Sectional drawing which illustrates one form of the solar cell module by this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  In this specification, “acrylic resin” includes methacrylic resin, and “acrylate” includes “methacrylate”. “Film”, “sheet”, and “plate” are sometimes distinguished by their rough thicknesses, but are not particularly distinguished in this specification.

1. Solar Cell Module Front Sheet The solar cell module front sheet is a sealing substrate used on the light receiving surface side of the solar cell element of the solar cell module. In addition, the solar cell module backsheet is a sealing substrate used on the side opposite to the light receiving surface of the solar cell element.

  FIG. 1 is a cross-sectional view illustrating one embodiment of a front sheet for a solar cell module according to the present invention. A solar cell module front sheet 10 shown in FIG. 1 includes a first transparent film 1, a second transparent film 5, and an adhesive layer 6. When the solar cell module front sheet 10 is used for a solar cell module, it is assumed that the surface of the solar cell module front sheet 10 on the first transparent film 1 side is directed toward the light incident side of sunlight L. doing.

  The first transparent film 1 and the second transparent film 5 are transparent. Transparent means that the 1st transparent film 1 and the 2nd transparent film 5 permeate | transmit the light of the wavelength which a solar cell element can photoelectrically convert. Although the wavelength that can be photoelectrically converted by the solar cell element varies depending on the type of the solar cell element, the first transparent film 1 and the second transparent film 5 transmit light in the entire region of the wavelength that can be photoelectrically converted by the solar cell element. It is not necessary to transmit the light in a partial region. Since a general solar cell element can be photoelectrically converted with light having a wavelength in the visible light region, the first transparent film 1 and the second transparent film 5 transmit at least part of the light in the visible light region. It is preferable.

  The first transparent film 1 is made of resin. The second transparent film 5 has a configuration in which an organic layer 3 and an inorganic layer 4 are formed in this order on a polyester resin substrate 2. The inorganic layer 4 of the second transparent film 5 has at least an inorganic compound exhibiting gas barrier properties, and the organic layer 3 of the second transparent film 5 has an oxyalkylene group having no hydroxyl group and a fluorene group. At least an acrylic resin containing a structural unit. The adhesive layer 6 is disposed on one surface side of the first transparent film and the surface side having the organic layer and the inorganic layer of the second transparent film, and the first transparent film and the second transparent film. The inorganic layer is laminated.

  By including the acrylic resin containing the structural unit in which the oxyalkylene group which does not have a hydroxyl group, and a fluorene group exists in the organic layer 3, the gas barrier property of the front sheet | seat for solar cell modules becomes favorable. The reason is presumed as follows. That is, since an oxyalkylene group having no hydroxyl group exists in the structural unit of the acrylic resin, adsorption of low molecular components such as moisture to the organic layer 3 is suppressed. Furthermore, since a fluorene group is present in the structural unit of the acrylic resin, the heat resistance and plasma resistance of the organic layer 3 are improved. As a result, the heat and plasma when forming the inorganic layer 4 on the organic layer 3 are increased. Thus, the low-molecular component such as moisture does not come out as gas from the inside of the organic layer, and the inorganic layer 4 with few defects is formed without inhibiting the film formation of the inorganic layer 4. As a result, gas barrier properties are improved.

  Next, each layer will be further described.

<First transparent film>
The first transparent film 1 is a resin-made transparent film.

  As the resin used for the first transparent film 1, a known resin can be used. Specific examples include acrylic resins, fluororesins, polyester resins, polycarbonate resins, polyimide resins, vinyl resins, and styrene resins. Of these, acrylic resins and fluororesins are preferred because they have high resistance to heat and light and are difficult to yellow or whiten. Furthermore, an acrylic resin is more preferable because it is excellent in transparency.

  Although the thickness of the 1st transparent film 1 is not specifically limited, For example, it is 9-500 micrometers, and it is 9-300 micrometers from points, such as mechanical strength and flexibility, More preferably, it is 12-200 micrometers. The lower limit particularly affects the decrease in mechanical strength, and the upper limit particularly affects flexibility. Moreover, since the transmittance | permeability falls when the thickness of the 1st transparent film 1 is thick, it is more preferable to set it as 50 micrometers or less.

  The first transparent film 1 preferably contains an ultraviolet absorber. When the solar cell module front sheet 1 is used for a solar cell module, it is assumed that the surface of the solar cell module front sheet 1 on the first transparent film 1 side is directed toward the light incident side of sunlight L. Therefore, the 1st transparent film 1 itself, the adhesion layer and the 2nd transparent film which exist in the lower layer can be protected from an ultraviolet-ray by making the 1st transparent film 1 contain a ultraviolet absorber. Because.

  As the ultraviolet absorber contained in the first transparent film 1, known ultraviolet absorbers can be used as appropriate. For example, benzophenone-based, benzotriazole-based, salicylate-based, acrylonitrile-based organic systems, metal complex salts, super Examples thereof include inorganic systems such as fine particle titanium oxide and ultrafine particle zinc oxide. These ultraviolet absorbers can be used alone or in combination of two or more. The ultrafine titanium oxide preferably has a particle size of 0.01 to 0.06 μm, and the ultrafine zinc oxide preferably has a particle size of 0.01 to 0.04 μm. The ultraviolet absorber can be contained in the first transparent film 1 by kneading into the resin.

  When the first transparent film 1 contains an ultraviolet absorber, the transmittance of the first transparent film 1 with respect to the ultraviolet rays is such that the transmittance is less than 5% in the ultraviolet rays having wavelengths of 240 to 400 nm. It is desirable to be. Each said wavelength is the meaning of each wavelength when the wavelength range of the range of 240 nm to 400 nm is measured at wavelength 1 nm intervals. The first transparent film 1, the adhesive layer 6, and the second transparent film 5 are obtained by setting the transmittance of the first transparent film 1 to less than 5% in the ultraviolet rays having wavelengths of 240 to 400 nm. Sufficient protection from ultraviolet rays can prevent yellowing and whitening.

<< 2nd transparent film >>
The second transparent film 5 is a transparent film in which an organic layer 3 and an inorganic layer 4 are formed in this order on a polyester resin substrate 2.

[Polyester resin substrate]
The polyester resin substrate 2 is a substrate of the second transparent film 5 and is made of a polyester resin. Since the polyester resin is relatively difficult to shrink by heat and light, the use of the polyester resin for the base material of the second transparent film 5 causes the base material to shrink by heat and light, and the inorganic layer 4 is cracked. The gas barrier property can be prevented from being lowered. In addition, since the polyester resin has high solvent resistance and heat resistance, even when a solvent is used or a heat load is applied when forming the organic layer 3 or the inorganic layer 4 on the polyester resin base material. Further, it is possible to prevent the base material from being deteriorated due to the solvent or heat, causing defects such as minute holes in the inorganic layer 4 and lowering the gas barrier property.

  As the polyester resin, any known polyester resin can be appropriately used. For example, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), or a copolymer thereof. Or polycyclohexanedimethylene terephthalate (PCT). Among these polyester resins, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and copolymers thereof are preferable in terms of versatility, heat resistance, mechanical strength, and the like.

  The thickness of the polyester resin substrate 2 is not particularly limited, but is preferably 9 to 500 μm, for example. In terms of mechanical strength, flexibility, etc., for example, 9 to 300 μm is more preferable, and 12 to 200 μm is more preferable. The lower limit particularly affects the decrease in mechanical strength, and the upper limit particularly affects flexibility.

  Adhesiveness with other layers such as the organic layer 3 on the surface of the polyester resin substrate 2 (the surface on the side where the organic layer 3 is formed, the surface where the organic layer 3 is not formed, or both surfaces) In order to improve the surface treatment, a surface treatment can be performed in advance as necessary. Examples of the surface treatment include 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. By the surface treatment, for example, a corona treatment layer, an ozone treatment layer, a plasma treatment layer, an oxidation treatment layer and the like are formed.

  When the organic layer 3 is formed only on one side of the polyester resin base material 2, the surface of the polyester resin base material 2 on the side where the organic layer 3 is not formed is subjected to surface treatment to Adhesion with other layers to be stacked can be improved. As another layer laminated | stacked on this surface, the layer of the sealing material when using the front sheet | seat 10 for a solar cell module can be mentioned, for example.

[Organic layer]
The organic layer 3 is a layer having an acrylic resin including a structural unit in which an oxyalkylene group having no hydroxyl group and a fluorene group are present. When the organic layer 3 includes an oxyalkylene group having no hydroxyl group and an acrylic resin containing a structural unit in which a fluorene group is present, good gas barrier properties can be obtained. Here, the presence or absence of a hydroxyl group in the organic layer can be measured according to JIS K 1557-1970. That is, the sample is made into a pyridine solution containing acetic anhydride, and the hydroxyl group is acetylated under reflux of pyridine. This reaction can be promoted by using imidazole as a catalyst, and excess acetylating reagent can be hydrolyzed with water, and the resulting acetic acid can be measured by titration with a standard solution of sodium hydroxide.

  The thickness of the organic layer 3 is preferably 0.1 to 20 μm or less, and more preferably 0.5 to 10 μm or less.

As the acrylic resin, a resin containing a structural unit represented by the following general formula [1] can be preferably used.

In the general formula [1], n ₁ and n ₂ are 0 or positive integers having the same or different values, and n ₁ + n ₂ is 1 to 20. R ¹ and R ² are each independently a hydrogen atom or a methyl group; R ³ and R ⁴ are each independently a hydrogen atom, a methyl group or an ethyl group; and R ⁵ and R ⁶ are each independently And a hydrogen atom, a methyl group or an ethyl group.
In particular, R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are preferably independent of each other and are each a hydrogen atom or a methyl group, and R ¹ , R ² , R ³ , R ⁴ , R ⁵ , More preferably, R ⁶ is the same and is a hydrogen atom or a methyl group.

By setting it as the organic layer 3 which made said n < ₁ > + n < ₂ > 1-20, it can contribute to the favorable gas barrier property by formation of the homogeneous inorganic layer 4. FIG. If n ₁ + n ₂ is 0, the crystallinity of the resin of the organic layer 3 becomes high and is difficult to dissolve, making it difficult to form a resin composition for forming an organic layer or reducing the coating suitability. On the other hand, if n ₁ + n ₂ is 21 or more, the linear molecular chain of the alkylene oxide increases in the organic layer, and it is likely that a low molecular component is easily incorporated into the molecular chain.

When n ₁ + n ₂ increases, the glass transition temperature Tg of the organic layer 3 decreases, and the crystallization of the organic layer 3 proceeds due to the influence of heat and plasma when forming the inorganic layer 4 on the organic layer 3, The organic layer 3 may be whitened. Whitening is not preferable because the transparency of the organic layer 3 decreases. Further, when whitened, the surface of the organic layer 3 becomes rough, and cracks are likely to occur in the inorganic layer 4 formed on the organic layer 3, which may deteriorate the gas barrier property. From such a point of view, n ₁ + n ₂ is preferably 1 to 6, and the glass transition temperature Tg of the organic layer 3 can be increased. As a result, good gas barrier properties and good transparency of the organic layer can be stably obtained. Moreover, since it becomes easy to form a suitable unevenness | corrugation on the surface of an inorganic layer with the method mentioned later, the adhesiveness between a 1st transparent film and a 2nd transparent film can be made high.

The organic layer 3 is made of an acrylic resin having a structural unit represented by the general formula [1] (wherein n ₁ + n ₂ in the general formula [1] is 1 to 6), whereby the organic layer is crosslinked with ultraviolet rays. After forming the inorganic layer 4 on the organic layer, an ion plate to which a heat load is applied while cooling the surface of the polyester resin substrate opposite to the surface on which the organic layer is formed. When formed by ting, irregularities can be formed on the surface of the inorganic layer. By forming irregularities on the surface of the inorganic layer, the contact area between the inorganic layer and the adhesive layer formed thereon increases, so that the first transparent film 5 and the first transparent film 5 are formed on the surface of the inorganic layer via the adhesive layer 6. In the solar cell module front sheet 10 in which the transparent film 1 is laminated, the adhesion between the first transparent film and the second transparent film can be improved. The reason why irregularities are formed on the surface of the inorganic layer is not certain, but is presumed as follows. That is, unreacted components remain in the organic layer formed by crosslinking with ultraviolet rays. And when forming an inorganic layer by ion plating, hardening of the unreacted component is accelerated | stimulated by the thermal load of the ion which collides with an organic layer. However, the acrylic resin having the structural unit represented by the general formula [1] (n ₁ + n ₂ in the general formula [1] is 1 to 6) has a high Tg, and the both sides of the polyester resin base material. Among them, the surface opposite to the surface on which the organic layer is formed is cooled, so that the unreacted component is cured only near the surface of the organic layer. As a result, the vicinity of the surface of the organic layer is distorted and unevenness is generated, and the inorganic layer is formed along the unevenness of the organic layer, so that the unevenness is formed on the surface of the inorganic layer.

  Cooling requires that the surface temperature of the surface opposite to the surface on which the organic layer is formed be at least a temperature lower than room temperature. A general guide for room temperature is about 25 ° C. Furthermore, in order to form sufficient irregularities without causing a decrease in transparency, the surface temperature of the surface opposite to the surface on which the organic layer is formed is preferably 5 ° C. or less, and 0 ° C. or less. More preferably, it is more preferably −10 ° C. or lower, and −20 ° C. or lower is sufficient. The cooling of the surface opposite to the surface on which the organic layer is formed is, for example, a metal roll or metal obtained by cooling a polyester resin base material on which the organic layer is formed using a refrigerant such as ethylene glycol or liquid nitrogen. It can be performed by a method in which the surface of the polyester resin base material on the side opposite to the surface on which the organic layer is formed and the surface of the metal roll or metal holder are in contact with the made holder.

  Specifically, it is preferable that the unevenness has a PV value of 200 nm or more and Ra of 35 nm or more from the viewpoint of the effect of improving adhesion. PV value and Ra are characteristic values of surface roughness based on JIS B0601 (2001 edition: 1997 edition of ISO4287), and PV values are the maximum value and valley of the roughness height at the reference length. It means the maximum height Rz (referred to as Ry in the 1994 edition of JIS) as the sum of the maximum depth and Ra means the arithmetic average roughness Ra. The PV value and Ra can be measured with an atomic force microscope (AFM) and an optical interference surface shape measuring device.

In addition, the structural unit represented by the general formula [1] is generated in the resin when, for example, a compound represented by the following general formula [2] is polymerized as a monomer.

In the general formula [2], n ₁ and n ₂ are 0 or a positive integer having the same or different values, and n ₁ + n ₂ is 1 to 20. R ¹ and R ² are each independently a hydrogen atom or a methyl group; R ³ and R ⁴ are each independently a hydrogen atom, a methyl group or an ethyl group; and R ⁵ and R ⁶ are each independently And a hydrogen atom, a methyl group or an ethyl group.
In particular, R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are preferably independent of each other and are each a hydrogen atom or a methyl group, and R ¹ , R ² , R ³ , R ⁴ , R ⁵ , More preferably, R ⁶ is the same and is a hydrogen atom or a methyl group.

  The compound represented by the general formula [2] can be synthesized by a known method. For example, it can be obtained by esterifying the hydroxyl group of an alkylene oxide-modified bisphenylfluorene compound having a hydroxyl group at the end of an alkylene oxide chain with acrylic acid or acrylic acid chloride.

  Examples of the alkylene oxide-modified bisphenylfluorene compound include 9,9-bis (4-hydroxyethyloxyphenyl) fluorene, 9,9-bis (3-methyl-4-hydroxyethyloxyphenyl) fluorene, and 9,9- Compounds such as bis (3-ethyl-4-hydroxyethyloxyphenyl) fluorene and 9,9-bis (3,3′-dimethyl-4-hydroxyethyloxyphenyl) fluorene.

  Alkylene oxide-modified bisphenylfluorene compounds include bisphenylfluorene compounds such as 9,9-bis (4-hydroxyphenyl) fluorene (also referred to as bisphenolfluorene), 9,9-bis (3- For compounds such as methyl-4-hydroxyphenyl) fluorene and 9,9-bis (3-ethyl-4-hydroxyphenyl) fluorene, ethylene oxide, propylene oxide, etc. with respect to the hydroxyl group bonded to the phenyl group To obtain an alkylene oxide.

  Moreover, the compound represented by General formula [2] can be obtained as a commercial item, for example, as NK ester series manufactured by Shin-Nakamura Chemical Co., Ltd., and Ogsol (registered trademark) EA series manufactured by Osaka Gas Chemical Co., Ltd.

  In addition, the oxyalkylene group which does not have a hydroxyl group in the range which does not deviate from the main point of this invention in the acrylic resin containing the structural unit in which the oxyalkylene group which does not have the hydroxyl group of the organic layer 3, and a fluorene group exists A structural unit other than the structural unit in which the group and the fluorene group are present may be contained. The ratio of the oxyalkylene group having no hydroxyl group and the structural unit in which the fluorene group is present to the other structural units is the ratio between the oxyalkylene group having no hydroxyl group and the structural unit in which the fluorene group is present and The mass ratio of other structural units is about 100: 0 to 50:50, preferably 100: 0 to 75:25. Within this range, it is considered that the predetermined object of the present invention can be achieved and a front seat with good gas barrier properties can be obtained without departing from the spirit of the present invention.

  Moreover, the organic layer 3 may contain resin other than the acrylic resin containing the structural unit in which the oxyalkylene group which does not have a hydroxyl group, and a fluorene group exist within the range which does not deviate from the main point of this invention. As the ratio of the oxyalkylene group having no hydroxyl group and the acrylic resin containing the structural unit in which the fluorene group is present to the other resin, the oxyalkylene group having no hydroxyl group and the fluorene group are present. The mass ratio of the structural unit to other structural units is about 100: 0 to 50:50, preferably 100: 0 to 75:25. Within this range, it is considered that the predetermined object of the present invention can be achieved and a front seat with good gas barrier properties can be obtained without departing from the spirit of the present invention.

    The organic layer 3 can contain various additives as needed within a range not departing from the gist of the present invention. Examples of such additives include heat stabilizers, ultraviolet absorbers, radical scavengers, antioxidants, plasticizers, surfactants, antistatic agents, infrared absorbers, light diffusing agents, pigments (colored dyes, Color pigments), extender pigments, and the like.

  The organic layer 3 preferably contains an ultraviolet absorber. By containing an ultraviolet absorber in the organic layer, the organic layer and the substrate can be protected from yellowing and whitening due to ultraviolet rays. As the ultraviolet absorber that can be used for the organic layer 3, the above-described ultraviolet absorber can be appropriately used as the ultraviolet absorber that can be used for the first transparent film 1.

[Inorganic layer]
The inorganic layer 4 is formed on the organic layer 3 described above, and is one or two or more layers having an inorganic compound exhibiting gas barrier properties, and is a layer responsible for a gas barrier function of blocking gas such as water vapor.

  As the inorganic compound exhibiting gas barrier properties, known compounds can be appropriately used. For example, inorganic compounds such as inorganic oxides, inorganic oxynitrides, inorganic nitrides, inorganic oxide carbides, inorganic oxycarbonitrides, and the like can be used. Two or more species can be used. Examples thereof include inorganic compounds containing one or more metal elements such as silicon, aluminum, magnesium, titanium, tin, indium, zirconium, yttrium, cerium, zinc and lead. Silicon oxide, aluminum oxide, magnesium oxide, titanium oxide, tin oxide, silicon zinc alloy oxide, indium alloy oxide, inorganic oxide such as silicon zinc oxide, silicon nitride, aluminum nitride, titanium nitride Inorganic nitrides such as oxides, inorganic oxynitrides such as silicon oxynitride, and the like are preferable, and silicon oxide, silicon nitride, silicon oxynitride, and silicon zinc oxide are particularly preferable.

  The thickness of the inorganic layer 4 may be appropriately determined in consideration of gas barrier properties, transparency, film strength, and the like. For example, the thickness is 5 to 1000 nm, preferably 5 to 500 nm, more preferably 10 nm to 200 nm, and still more preferably 50 to 50 nm. It is about 100 nm.

<Adhesive layer>
The adhesive layer 6 is disposed on one surface side of the first transparent film and the surface side having the organic layer and the inorganic layer of the second transparent film, and the first transparent film and the second transparent film. It is a layer which laminates the inorganic layer. And the 1st transparent film 1 is laminated | stacked on the inorganic layer side of the 2nd transparent film 5 via the contact bonding layer 6 by an adhesive agent etc., and the 2nd transparent film is because an inorganic layer side turns into a bonding surface. Each layer such as the inorganic layer 4 and the organic layer 3 constituting 5 is protected by the first transparent film 1. As a result, the gas barrier property can be maintained without destroying the inorganic layer 4 due to the handling of the front sheet 10 for the solar cell module, the influence of the sealing material on the solar cell element side, and the like.

  As the adhesive layer 6, a known adhesive can be used as long as it is an adhesive that adheres to both the first transparent film and the inorganic layer of the second transparent film. Examples of the adhesive used for the adhesive layer 6 include acrylic resin, urethane resin, epoxy resin, polyester resin, polyamide resin, polyolefin resin, phenol resin, ethylene-vinyl acetate copolymer, polyvinyl acetal resin, or a copolymer of these. Examples include coalescence and mixtures.

  As will be described later, the adhesive layer 6 can be formed by applying an adhesive on the adhesive surface of the first transparent film 1 or the second transparent film 5 and then bonding these films together. The thickness of the adhesive layer 6 is desirably a thickness that can completely fill the surface irregularities of the inorganic layer 4 that is the adhesion surface, and therefore is preferably not less than the surface irregularities, and therefore the lower limit is desirably 1 μm or more. Therefore, the thickness of the adhesive layer 6 is preferably about 1 to 5 μm, for example.

  The adhesive layer 6 preferably contains an ultraviolet absorber. By containing the ultraviolet absorber in the adhesive layer, the adhesive layer, the organic layer, and the polyester resin substrate can be protected from yellowing and whitening due to ultraviolet rays. As the ultraviolet absorber to be contained in the adhesive layer 6, known ultraviolet absorbers can be appropriately used. For example, benzophenone-based, benzotriazole-based, salicylate-based, acrylonitrile-based organic systems, metal complex salts, ultrafine titanium oxide And inorganic type such as ultrafine zinc oxide. These ultraviolet absorbers can be used alone or in combination of two or more. The ultrafine titanium oxide preferably has a particle size of 0.01 to 0.06 μm, and the ultrafine zinc oxide preferably has a particle size of 0.01 to 0.04 μm. The ultraviolet absorber can be contained in the adhesive layer 6 by mixing with the adhesive or by introducing it as a functional group into the adhesive.

  When the ultraviolet absorber is contained in the adhesive layer 6, it is desirable that the transmittance of the adhesive layer 6 with respect to the ultraviolet light is less than 5% in the ultraviolet light having each wavelength in the range of 240 to 400 nm. Each said wavelength is the meaning of each wavelength when the wavelength range of the range of 240 nm to 400 nm is measured at wavelength 1 nm intervals. By making the transmittance of the first adhesive layer 6 less than 5% in the ultraviolet rays of each wavelength in the wavelength range of 240 to 400 nm, the adhesive layer 6 and the second transparent film 5 are sufficiently protected from the ultraviolet rays. Whitening can be prevented.

《Other constituent layers》
The solar cell module front sheet 10 may have a film or layer other than the first transparent film 1, the second transparent film 5, and the adhesive layer 6.
Moreover, even if the 1st transparent film 1 or the 2nd transparent film 5 has a film or layer other than the above-mentioned film or layer which comprises the 1st transparent film 1 or the 2nd transparent film 5. Good. For example, functional layers such as an antireflection layer, a hard coat layer, an antifogging layer, an antifouling layer, and a protective layer may be formed on the light incident side surface of the first transparent film 1. Moreover, the 1st transparent film 1 or the 2nd transparent film 5 may have an antistatic layer, a smoothing layer, a stress relaxation layer, and an easily bonding layer.

《Gas barrier performance, transparency》
By setting it as the above structures, the front sheet | seat 10 for solar cell modules by this invention can also make gas barrier property with respect to water vapor | steam 0.05g / m < ² > * day or less, for example. The gas barrier property against water vapor, that is, the water vapor transmission rate, can be measured using, for example, a commercially available water vapor transmission rate measuring apparatus (manufactured by MOCON, USA, PERMATRAN, etc.).

  Moreover, since the 1st transparent film 1 and the 2nd transparent film 5 are employ | adopted for the solar cell module front sheet | seat 10 by this invention, it is excellent in transparency. Furthermore, by including an ultraviolet absorber in the first transparent film 1 and / or the adhesive layer 6, the adhesive layer 6, the inorganic layer 4, the organic layer 3, It is possible to suppress a decrease in light transmittance due to yellowing or white turbidity due to alteration of the transparent film 5 and the sealing material. As a result, a decrease in power generation efficiency of the solar cell module due to a decrease in light transmittance can be prevented.

2. Solar Cell Module The solar cell module according to the present invention is disposed on the solar cell element 21 and the light incident surface side that is the front side of the solar cell element 21 as in the solar cell module 20 illustrated in the cross-sectional view of FIG. The solar cell module includes the above-described solar cell module front sheet 10 and a solar cell module backsheet 22 disposed on the rear surface side of the solar cell element 21. At this time, the solar cell module front sheet 10 is arranged with the first transparent film 1 side as the light incident surface and the second transparent film 5 facing the solar cell element 21 side. Further, the solar cell element 21 is hermetically sealed by a front solar cell module front sheet 10, a rear solar cell module back sheet 22, and a sealing material 23 for bonding them. .

  In the solar cell module 20 according to the present invention, the constituent elements other than the solar cell module front sheet 10 are not particularly limited, and known components according to applications can be appropriately employed. The components explicitly shown in the figure are a solar cell element 21, a solar cell module backsheet 22, a sealing material 23, and the like. As the solar cell element 21, crystalline, microcrystalline, and amorphous silicon type solar cell elements, compound semiconductor type solar cell elements, organic semiconductor type solar cell elements, dye-sensitized solar cell elements, and the like can be used. For the solar cell module backsheet 22, for example, a fluorine-based film, a vapor-deposited polyethylene terephthalate film, or the like can be used. For the sealing material 23, for example, an ethylene-vinyl acetate copolymer (EVA) film, an ionomer resin film, or the like can be used. In addition, there are no particular limitations on components (for example, lead wires, electrode terminals, terminal boxes, etc.) not explicitly shown in the figure, and known components can be appropriately employed depending on the application.

  As the front sheet of the solar cell module 20, the above-described first transparent film made of resin and a second layer having an organic layer and an inorganic layer having an inorganic compound exhibiting gas barrier properties in this order on the polyester resin base material. A transparent film, an adhesive layer disposed between the first transparent film and the inorganic layer of the second transparent film, and laminating the first transparent film and the inorganic layer of the second transparent film And the organic layer has an acrylic resin, and the acrylic resin of the organic layer has an oxyalkylene group having no hydroxyl group and a fluorene group. By adopting the solar cell module front sheet including the unit, the gas barrier property of the front sheet is good. Of the solar cell module can be suppressed over time performance degradation Lumpur, durability is improved.

3. Manufacturing method of front sheet for solar cell module The manufacturing method of the front sheet for solar cell module of the present invention is not particularly limited. For example, a preparation step for preparing a first transparent film, a second transparent film Can be manufactured through a manufacturing process and a stacking process.

<< Preparation process for preparing the first transparent film >>
The preparatory process for preparing the first transparent film is a process for preparing the first transparent film made of resin. Even if the first transparent film is appropriately prepared and prepared by a known method, a commercially available product is inherited. May be prepared. As a known method for producing the first transparent film made of resin, for example, a method of forming a film by melt extrusion of a molten monomer or polymer can be mentioned. After film formation, uniaxial stretching or biaxial stretching may be performed by a known stretching method as necessary.

<< Production Process for Producing Second Transparent Film >>
The production process for producing the second transparent film includes an organic layer having an acrylic resin containing a structural unit in which an oxyalkylene group having no hydroxyl group and a fluorene group are present on a polyester resin substrate, and gas barrier properties It is the process of producing the 2nd transparent film which has the inorganic layer which has an inorganic compound which shows this order.

[Organic layer formation process]
The organic layer forming step includes, for example, an acrylic resin including a structural unit in which an oxyalkylene group having no hydroxyl group and a fluorene group are present on the above-described polyester resin substrate 2 by a known coating method or printing method. A method of forming a layer can be used. Alternatively, after forming a layer of an acrylate containing a oxyalkylene group having no hydroxyl group and a fluorene group by a known coating method or printing method, an ultraviolet polymerization method, an electron beam polymerization method, or a thermal polymerization method A method of polymerizing by a known method such as a combination method can be used.

  In particular, on a polyester resin base material, a composition containing an acrylate having a hydroxyl group-free oxyalkylene group and a fluorene group-containing structural unit and a known polymerization initiator is known as a known coating method or printing method. The method of forming an organic layer by forming a layer with, and then crosslinking with ultraviolet rays can be preferably used because the cost can be reduced in terms of equipment.

  Examples of known coating methods and printing methods include roll coating, gravure roll coating, kiss roll coating, reverse roll coating, gravure coating, die coating, and spin coating.

[Inorganic layer forming step]
The inorganic layer 4 may be formed by any method that can form a dense and uniform film. For example, physical vapor deposition (PVD) such as vacuum deposition, sputtering, or ion plating, or plasma CVD. A vapor phase growth method such as chemical vapor deposition (CVD) such as a thermal CVD method is preferred. Among these, the ion plating method is a method in which a raw material is ionized with a plasma beam generated by a plasma gun and deposited on an organic layer, and is preferable because a high film formation rate can be obtained.

<< Lamination process >>
In the laminating step, the first transparent film prepared in the above preparation step and the second transparent film prepared in the above preparation step are placed on either side of the first transparent film. This is a laminating step of laminating an adhesive layer between the first transparent film and the inorganic layer of the second transparent film so as to face the surface side having the organic layer and the inorganic layer of the transparent film.

  As a method for forming the adhesive layer between the first transparent film and the inorganic layer of the second transparent film, for example, an adhesive is known for the first transparent film and / or the inorganic layer of the second transparent film. After forming the layer using the coating method or printing method, the first transparent film and the second transparent film may be bonded together.

<< Other processes >>
In the manufacturing method of the solar cell module front sheet by this invention, processes other than the above-mentioned preparation process, preparation process, and lamination process may be included. As such a process, for example, a process of forming an antireflection layer on the first transparent film 1, a process of subjecting the polyester resin substrate surface to an easy-adhesion treatment in the production process of the second transparent film, etc. Can be mentioned.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

[Performance evaluation method]
Each performance was evaluated by the following method.

(Water vapor transmission rate)
As an evaluation of the gas barrier property against water vapor, the water vapor permeability before and after the following light resistance test was measured using a water vapor permeability measuring apparatus (PERMATRAN) manufactured by MOCON USA under the condition of a temperature of 40 ° C. and a relative humidity of 90% RH. . In the evaluation, 0.05 g / m ² · day (40 ° C., 90% RH) or less is acceptable (◯), and 0.05 g / m ² · day (40 ° C., 90% RH) is not acceptable (×).

(Light resistance test)
In the light resistance test, the sample was irradiated with an ultraviolet light degradation acceleration tester (Isuper UV Tester SUV-W23 manufactured by Iwasaki Electric Co., Ltd.), the ultraviolet irradiation intensity was 100 mW / cm ² , the environment in the tank: 60 ° C., 50% RH, irradiation Time: Performed by irradiating with ultraviolet rays under the condition of 168 hours.

(Surface irregularities of the inorganic layer)
As an evaluation of the surface roughness of the inorganic layer, using an atomic force microscope AFM (Nanopics (registered trademark) 1000 manufactured by Seiko Instruments Inc.) and an optical interference type surface shape measuring device (SP500 manufactured by Toray Engineering Co., Ltd.) PV value and Ra were measured.
(Adhesion)
As an adhesion evaluation, using a tensile tester (Tensilon universal material tester manufactured by A & D Co., Ltd.), the first transparent film 1 and the second transparent film 5 of a sample having a width of 15 mm are moved 90 degrees. The tensile tension when peeled in the direction at a speed of 5 mm / s was measured. In the evaluation, 5N / 15mm or more was acceptable (◯), and 5N / 15mm excess was impossible (x).

[Example 1]
As the first transparent film, a 33 μm thick acrylic resin film (trade name: Sandulen (registered trademark) manufactured by Kaneka Corporation) containing an ultraviolet absorber was prepared. The transmittance of each wavelength in the range of 240 to 400 nm which is the ultraviolet light region of this film is less than 5%.

Next, as a polyester resin base material, a biaxially stretched polyethylene terephthalate film (Toyobo Co., Ltd., Cosmo Shine (registered trademark) A-4300) having a thickness of 100 μm was prepared, and on one side of the polyethylene terephthalate film, After applying the ultraviolet curable composition (1) adjusted to the above composition by spin coating and drying at 120 ° C. for 2 minutes, the composition was irradiated with ultraviolet rays under the condition of an integrated light quantity of 300 mJ / cm ² in the wavelength range of 260 to 400 nm. Irradiation was performed to form an organic layer having a thickness of 1 μm.

(Composition of UV curable composition (1))
Compound of the above general formula [2] (R ^{1 to} R ⁶ are hydrogen atoms, n ₁ = n ₂ = 1, n ₁ + n ₂ = 2) (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name: NK ester A-BPEF) ): 38 parts by mass, toluene: 60 parts by mass, oligo [2-hydroxy-2-methyl- [1- (methylvinyl) phenyl] propanone] (polymerization initiator, manufactured by US Lamberti, trade name: ESACURE ONE): 2 parts by weight.

The surface of the polyethylene terephthalate film on which the organic layer is formed is oriented to form a film on the organic layer side of the polyethylene terephthalate film on which the organic layer is formed. The sample was placed in contact with a cooling roller cooled in step 1 and mounted on a hollow cathode ion plating apparatus. Then, a deposition source material of silicon zinc oxide (a material obtained by mixing silicon oxide powder and zinc oxide powder so that the weight ratio of silicon oxide: zinc oxide is 10: 6 and then pressing and solidifying) is ionized. After putting in the crucible of the plating apparatus, vacuuming was performed. After the degree of vacuum reached 5 × 10 ⁻⁴ Pa, 15 sccm of argon gas was introduced into the plasma gun, and plasma with a current of 110 A and a voltage of 90 V was generated. The inside of the chamber was maintained at 1 × 10 ⁻¹ Pa, the plasma was bent in a predetermined direction by a magnetic force, and the deposition source material was irradiated. It was confirmed that the vapor deposition source in the crucible sublimates through a molten state. By bringing the surface of the polyethylene terephthalate film on which the organic layer is formed opposite to the surface on which the organic layer is formed into contact with the cooling roller, ion plating is performed for 7.5 seconds to deposit on the organic layer, A silicon zinc oxide layer was formed as an inorganic layer with a film thickness of 50 nm to produce a second transparent film.

A urethane resin (trade name: Adlock (registered trademark) ADHESIVE) manufactured by Rock Paint Co., Ltd. is applied as an adhesive on the inorganic layer of the second transparent film with a wire bar to form an adhesive layer. The first transparent film was bonded face to face and pressed.
Thus, a solar cell module front sheet of Example 1 was produced.

[Example 2]
A front sheet for a solar cell module of Example 2 was produced in the same manner as in Example 1 except that the organic layer was formed using the ultraviolet curable composition (2) adjusted to the following composition.

(Composition of UV curable composition (2))
Compound of general formula [2] (R ^{1 to} R ⁶ are hydrogen atoms, n ₁ = n ₂ = 1, n ₁ + n ₂ = 2) (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name: NK ester A-BPEF) ): 34.2 parts by mass, polyester acrylate (manufactured by Toagosei Co., Ltd., trade name: M-8030): 3.8 parts by weight, toluene: 60 parts by mass, oligo [2-hydroxy-2-methyl- [1- (Methylvinyl) phenyl] propanone] (polymerization initiator, manufactured by US Lamberti, trade name: ESACURE ONE): 2 parts by mass.

[Example 3]
As the first transparent film, a 25 μm-thick fluororesin film (tetrafluoroethylene and ethylene copolymer (ETFE), manufactured by Asahi Glass Co., Ltd., trade name: Aflex (registered trademark)) is used as an adhesive. The solar cell module front of Example 3 is the same as Example 1 except that an acrylic resin having a functional group exhibiting an ultraviolet absorbing function (trade name: UV-G101, manufactured by Nippon Shokubai Co., Ltd.) is used. A sheet was produced. The transmittance of each wavelength in the range of 240 to 400 nm which is the ultraviolet light region of this adhesive layer is less than 5%.

[Example 4]
Other than forming a silicon oxide zinc layer on the organic layer while contacting the surface opposite to the surface on which the organic layer of the polyethylene terephthalate film on which the organic layer is formed with a cooling roller cooled at 0 ° C. Produced the solar cell module front sheet of Example 4 by the same method as in Example 1.

[ Reference example ]
Other than forming a silicon oxide zinc layer on the organic layer while bringing the surface opposite to the surface on which the organic layer of the polyethylene terephthalate film on which the organic layer has been formed into contact with a cooling roller cooled at 20 ° C. The solar cell module front sheet of the reference example was produced in the same manner as in Example 1.

[Comparative Example 1]
A solar cell module front sheet of Comparative Example 1 was produced in the same manner as in Example 1 except that the organic layer was not formed.

[Comparative Example 2]
In order to make the organic layer an acrylic resin having a structural unit represented by the following general formula [3] (R ^{1 to} R ⁶ are hydrogen atoms, n ₁ = n ₂ = 1, n ₁ + N ₂ = 2), A solar cell module front sheet of Comparative Example 2 was produced in the same manner as in Example 1 except that the organic layer was formed using the ultraviolet curable composition (3) adjusted to the above composition. The compound represented by the following general formula [4] (R ^{1 to} R ⁶ are hydrogen atoms, n ₁ = n ₂ = 1, n ₁ + N ₂ = 2) used in the ultraviolet curable composition (3) is: Since the structure includes an oxyalkylene group having a hydroxyl group and a fluorene group, the following general formula [4] (R ^{1 to} R ⁶ are hydrogen atoms, n ₁ = n ₂ = 1, n ₁ The organic layer formed using the compound of + n ₂ = 2) has an acrylic resin containing a structural unit in which an oxyalkylene group having a hydroxyl group of the following general formula [3] and a fluorene group are present.

(Composition of UV curable composition (3))
Compound of the following general formula [4] (R ^{1 to} R ⁶ are hydrogen atoms, n ₁ = n ₂ = 1, n ₁ + N ₂ = 2): 34.2 parts by mass, polyester acrylate (manufactured by Toagosei Co., Ltd., product) Name: M-8030): 3.8 parts by weight, toluene: 60 parts by mass, oligo [2-hydroxy-2-methyl- [1- (methylvinyl) phenyl] propanone] (polymerization initiator, manufactured by Lamberti, USA) Product name: ESACURE ONE): 2 parts by mass.

  The compound of the general formula [4] was synthesized as follows. First, 231 g (epoxy equivalent 231) of bisphenolfluorene type epoxy compound, 450 mg of triethylbenzylammonium chloride, 100 mg of 2,6-di-isobutylphenol, and 72.0 g of acrylic acid are charged and mixed in a 500 mL four-necked flask. Then, it was dissolved by heating at 90 to 100 ° C. while blowing air at a rate of 25 mL per minute. Although this solution was cloudy, the temperature was gradually raised as it was, and the solution was heated to 120 ° C. to be completely dissolved. Although the solution gradually became transparent and viscous, the stirring was continued as it was, and during this time, the acid value was measured, and this heating and stirring was continued until the acid value became less than 2.0 mgKOH / g. After 8 hours when the acid value reached the target (acid value 0.8), the mixture was cooled to room temperature to obtain a compound of the general formula [4], which was a colorless and transparent solid.

[Comparative Example 3]
A front sheet for a solar cell module of Comparative Example 3 was produced in the same manner as in Example 1 except that the organic layer was formed using an ultraviolet curable composition (4) adjusted to the following composition. The polyester acrylate used in the ultraviolet curable composition (4) has no oxyalkylene group or fluorene group in its structure.

(Composition of UV curable composition (4))
Polyester acrylate (manufactured by Toagosei Co., Ltd., trade name: M-8030): 38 parts by weight, toluene: 60 parts by mass, oligo [2-hydroxy-2-methyl- [1- (methylvinyl) phenyl] propanone] (polymerization) Initiator, manufactured by US Lamberti, trade name: ESACURE ONE): 2 parts by mass.

[Evaluation results]
The evaluation results are shown in Table 1.

As shown in Table 1, the solar cell module front sheets of Examples 1 to 5 have an oxyalkylene group having no hydroxyl group in the organic layer and an acrylic resin containing a structural unit in which a fluorene group is present. Before and after the light resistance test, the water vapor transmission rate was 0.05 g / m ² · day (40 ° C., 90% RH) or less, indicating good gas barrier properties. On the other hand, the solar cell module front sheets of Comparative Examples 1 to 3 have a water vapor transmission rate before and after the light resistance test of more than 0.05 g / m ² · day (40 ° C. and 90% RH), and have poor gas barrier properties. It was.

  Further, the front sheet for the solar cell module of Example 1 had a total light transmittance of 90% or more measured with a haze meter manufactured by Suga Test Instruments Co., Ltd., whereas the front sheet for the solar cell module of Example 2 The total light transmittance measured in the same manner as in Example 1 was less than 90%. Therefore, it turns out that it is preferable to use an acrylic resin film for the first transparent film.

  Further, the solar cell module front sheet of Example 5 was inferior in adhesion to the solar cell module front sheets of Examples 1 to 4. As for the unevenness | corrugation of the inorganic layer of the front sheet | seat for solar cell modules of Examples 1-4, PV is 200 nm or more, and Ra is 35 nm or more. An inorganic compound having gas barrier properties is formed on the organic layer while bringing the surface opposite to the surface on which the organic layer of the polyethylene terephthalate film on which the organic layer has been formed into contact with a cooling roller cooled at 0 ° C. or lower. It is presumed that by forming the inorganic layer, moderate irregularities were formed in the inorganic layer and the adhesion was improved. An inorganic compound having gas barrier properties is formed on the organic layer while bringing the surface opposite to the surface on which the organic layer of the polyethylene terephthalate film on which the organic layer has been formed into contact with a cooling roller cooled at 0 ° C. or higher. It can be seen that forming the inorganic layer has a more preferable manufacturing method because a front sheet for a solar cell module with good gas barrier properties and adhesion can be obtained.

DESCRIPTION OF SYMBOLS 1 1st transparent film 2 Base material made from polyester resin 3 Organic layer 4 Inorganic layer 5 2nd transparent film 6 Adhesive layer 10 Front sheet | seat for solar cell modules 20 Solar cell module 21 Solar cell element 22 Solar cell module back sheet 23 Sealing Stop material L light

Claims (5)

A first transparent film made of resin;
On the polyester resin substrate, a second transparent film having an organic layer and an inorganic layer having an inorganic compound exhibiting gas barrier properties in this order;
It arrange | positions in the surface side which has the organic layer and inorganic layer of any one surface side of a said 1st transparent film, and a said 2nd transparent film, The inorganic layer of a said 1st transparent film and a said 2nd transparent film And an adhesive layer for laminating
A front sheet for a solar cell module having
The organic layer has an acrylic resin;
Acrylic resin of the organic layer, viewed contains a structural unit oxyalkylene group having no hydroxyl group, and a fluorene group are present,
The organic layer has irregularities in the vicinity of the surface of the organic layer;
The inorganic layer is formed so as to be along the surface having irregularities of the organic layer, and the surface of the inorganic layer has irregularities having a PV value of 200 nm or more and Ra of 35 nm or more.
Front seat for solar cell module. The acrylic resin of the organic layer has the following general formula [1] (in the general formula [1], n ₁ and n ₂ are 0 or a positive integer, and n ₁ + n ₂ is 1 to 20. R ¹ and R 2 ² is a hydrogen atom or a methyl group, R ³ and R ⁴ are a hydrogen atom, a methyl group or an ethyl group, and R ⁵ and R ⁶ are a hydrogen atom, a methyl group or an ethyl group. The front sheet | seat for solar cell modules of Claim 1 containing a unit.

The front sheet | seat for solar cell modules of Claim ₂ whose n < ₁ > + n < ₂ > is 1-6 in the said general formula [1]. In a solar cell module provided with a solar cell module front sheet, a solar cell element, and a solar cell module backsheet,
The solar cell module front sheet is the solar cell module front sheet according to any one of claims 1 to 3, and the solar cell module front sheet has a surface on the second transparent film side as the surface. A solar cell module disposed toward the solar cell element. A preparation step of preparing a first transparent film made of resin;
On the polyester resin substrate, the following general formula [2] (in the general formula [2], n ₁ and n ₂ are 0 or a positive integer, and n ₁ + n ₂ is 1 to 6. R ¹ and R 2 ² is a hydrogen atom or a methyl group, R ³ and R ⁴ are a hydrogen atom, a methyl group or an ethyl group, and R ⁵ and R ⁶ are a hydrogen atom, a methyl group or an ethyl group. And an organic layer forming step of forming an organic layer by cross-linking a composition containing a polymerization initiator with ultraviolet rays, and

An inorganic compound that exhibits gas barrier properties on the organic layer while cooling the surface opposite to the surface on which the organic layer is formed on both surfaces of the polyester resin substrate so that the surface temperature is 0 ° C. or lower . Including an inorganic layer forming step of forming an inorganic layer having an ion plating method.
A production step of producing a second transparent film;
The organic layer of the second transparent film and the first transparent film prepared in the preparation step and the second transparent film prepared in the preparation step are disposed on one surface side of the first transparent film, and A laminating step of laminating an adhesive layer between the first transparent film and the inorganic layer of the second transparent film so as to face the surface side having the inorganic layer;
A method for manufacturing a front sheet for a solar cell module.

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