JP2013161817A - Polymer sheet and back sheet for solar cell module, and solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polymer sheet for a solar cell module, which has sufficient black color density to obtain excellent design properties and is excellent in insulation properties, even though manufacturing cost thereof is low.SOLUTION: A polymer sheet for a solar cell module includes a polyester support and a coloring layer disposed on at least one surface of the polyester support. The coloring layer contains a binder comprising an organic polymer, carbon black and metal oxide fine particles, and satisfies the following expression. 1≤W2/W1≤10 (W1 represents a content (unit: mass%) of the carbon black in the coloring layer, and W2 represents a content (unit: mass%) of the metal oxide fine particles in the coloring layer.)

Description

  The present invention relates to a polymer sheet for a solar cell module, a back sheet for a solar cell module, and a solar cell module.

  The solar cell module has a structure in which the solar cell is protected by two sheet-like protective members, and the solar cell is sealed with a sealing material between the protective members. One protective member is a surface member disposed on the light receiving surface side that receives sunlight, and the other protective member is a so-called solar cell module backsheet (hereinafter referred to as a solar cell) disposed on the back side of the solar cell. It is also referred to as a back sheet or a back sheet). The surface member is usually made of glass, and an ethylene-vinyl acetate copolymer (EVA) is usually used as the sealing material.

The solar cell back sheet has a function of preventing moisture from entering from the back surface of the solar cell module. Conventionally, glass or the like has been used, but in recent years, a polymer represented by a polyester resin from the viewpoint of cost. Has come to be used.
At this time, in order to improve the appearance when the solar cell module is installed on the roof, it may be required to color the solar cell module black from the viewpoint of design. On the other hand, a method is generally known in which the solar battery back sheet is colored black to make the solar battery module black.

  In order to obtain a black solar battery back sheet, a black film is usually bonded to another sheet using an adhesive to form a back sheet. For example, a method of laminating a polyester resin film kneaded with carbon black fine particles on the innermost surface where the solar battery back sheet is in direct contact with the sealing material has been proposed (see Patent Document 1).

JP 2010-232588 A JP 2009-132877 A

Also, in order to obtain a sufficient black density with only black composite metal oxide without using carbon black, since the coloring power of the composite metal oxide is small, a large amount of metal oxide is used in the colored layer. It is necessary to increase the thickness of the colored layer, which is not preferable in terms of film strength and cost.
Carbon black used in Patent Document 1 is a preferable black pigment in which cost and performance are balanced as compared with a case where only a black composite metal oxide is compared with a black pigment. However, the polymer sheet for the solar cell module in which the black particles described in Patent Document 1 are kneaded into the polyester support must be handled separately from the raw material of the normal colorless and transparent polyester support when the polyester support is produced. Since it is necessary to use a dedicated raw material and a dedicated recovery facility, a polymer sheet for a solar cell module having a different configuration has been demanded from the viewpoint of manufacturing cost. In addition, it is difficult to adjust the black density and the color. From these viewpoints, a polymer sheet for a solar cell module having a configuration different from that described in Patent Document 1 has been demanded.

  On the other hand, in order to obtain a black solar battery back sheet with low manufacturing cost, a thin black layer containing carbon black at a high concentration using carbon black and a silane-modified ethylene resin binder is coated with a support. A method of providing on a (base film) has also been proposed (see Patent Document 2). However, since carbon black has electrical conductivity, the method described in Patent Document 2 has a high concentration of carbon black in the applied black layer, so that the carbon blacks are close to each other, so that It was found that there was a problem of electrical leakage and insulation failure.

  The problem to be solved by the present invention is to provide a polymer sheet for a solar cell module that has a sufficient black density, has excellent design properties, and has excellent insulation properties, despite its low production cost. .

As a result of intensive studies by the present inventors in order to solve the above problems, by using a polyester support as a support, by adding a metal oxide at a specific ratio to a colored layer containing carbon black, Improved electrical insulation. As a result, it was found that a polymer sheet for a solar cell module that has a sufficient black density, has excellent design properties, and has excellent insulating properties can be provided even though the manufacturing cost is low. That is, the present inventors have found that the above problem can be solved by the following configuration, and have completed the present invention.
The present invention, which is a specific means for solving the above problems, is as follows.

[1] A polyester support and a colored layer disposed on at least one side of the polyester support, wherein the colored layer contains an organic polymer binder, carbon black, and metal oxide fine particles, and the coloring A polymer sheet for a solar cell module, wherein the layer satisfies the following formula (1).
Formula (1)
1 ≦ W2 / W1 ≦ 10
(In Formula (1), W1 represents the content (unit: mass%) of carbon black in the colored layer, and W2 represents the content (unit: mass%) of metal oxide fine particles in the colored layer.)
[2] In the polymer sheet for a solar cell module according to [1], the metal oxide fine particles preferably include at least one of white metal oxide fine particles and black metal oxide fine particles.
[3] The polymer sheet for a solar cell module according to [1] or [2], wherein the metal oxide fine particles include at least one metal selected from titanium, cobalt, chromium, iron, manganese, copper, and silicon. It is preferable to include.
[4] In the polymer sheet for a solar cell module according to any one of [1] to [3], the metal oxide fine particles are at least one selected from titanium oxide, black composite metal oxide, and silicon dioxide. It is preferable to include two or more.
[5] In the polymer sheet for a solar cell module according to [4], it is preferable that the black composite metal oxide contains two or more of cobalt, chromium, iron, manganese, and copper.
[6] In the polymer sheet for a solar cell module according to [4] or [5], it is preferable that the black composite metal oxide includes at least one selected from PBk26, PBk27, and PBk28.
[7] In the polymer sheet for a solar cell module according to any one of [1] to [6], the metal oxide fine particles include at least one white metal oxide fine particle and at least one black metal particle. It is preferable that a composite metal oxide is included.
[8] In the polymer sheet for a solar cell module according to any one of [1] to [7], the binder composed of the organic polymer is at least selected from a resin including a polyolefin resin and a styrene-butadiene copolymer component. It is preferable to include one kind as a main component.
[9] In the polymer sheet for a solar cell module according to any one of [1] to [8], the thickness of the colored layer is preferably 0.3 to 6 μm.
[10] In the polymer sheet for a solar cell module according to any one of [1] to [9], the carbon black content W1 in the colored layer is preferably 5 to 18 masses.
[11] A back sheet for a solar cell module, comprising the polymer sheet according to any one of [1] to [10].
[12] A solar cell module comprising the back sheet for a solar cell module according to [11].

  According to the present invention, it is possible to provide a polymer sheet for a solar cell module that has a sufficient black density, is excellent in design properties, and is excellent in insulation, although the manufacturing cost is low.

It is a section schematic diagram showing roughly an example of composition of a polymer sheet for solar cell modules of the present invention. It is the cross-sectional schematic which shows roughly another example of a structure of the polymer sheet for solar cell modules of this invention. It is the cross-sectional schematic which shows roughly another example of a structure of the polymer sheet for solar cell modules of this invention. It is a section schematic diagram showing roughly an example of composition of a back sheet for solar cell modules of the present invention. It is the schematic which shows the cross section of the structure of the solar cell module of this invention.

Hereinafter, the polymer sheet for solar cell modules, the back sheet for solar cell modules, and the solar cell module of the present invention will be described in detail.
The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

[Polymer sheet for solar cell module]
The polymer sheet for a solar cell module of the present invention has a polyester support and a colored layer disposed on at least one side of the polyester support, and the colored layer is made of an organic polymer, carbon black, and metal oxide It is characterized by containing fine particles and the colored layer satisfies the following formula (1).
Formula (1)
1 ≦ W2 / W1 ≦ 10
(In Formula (1), W1 represents the content (unit: mass%) of carbon black in the colored layer, and W2 represents the content (unit: mass%) of metal oxide fine particles in the colored layer.) .
Hereinafter, the details of preferred embodiments of the configuration of the polymer sheet for the solar cell module of the present invention, each component, and the like will be described.

1 to 3 show an example of the configuration of the polymer sheet for the solar cell module of the present invention, FIG. 4 shows an example of the configuration of the back sheet for the solar cell module of the present invention, and FIG. 5 shows the polymer for the solar cell module of the present invention. An example of the structure of the solar cell module of this invention using a sheet | seat is shown.
The polymer sheet 20 for a solar cell module in FIG. 1 is provided with a colored layer 16 on one surface (colored surface 19) of a polyester support 18. In addition, when using the polymer sheet for solar cell modules of this invention as an aspect without such a weather resistant layer, it may be called a solar cell backsheet member.
The colored layer 16 is a functional layer having a polyolefin resin or the like as a main component and having good adhesion to the sealing material 24 for sealing the solar cell element 20 of the solar cell module 10 of the present invention shown in FIG. It is preferable. In this case, it is not necessary to provide an adhesive layer between the colored layer 16 of the polymer sheet 20 for the solar cell module of the present invention and the sealing material 24 of the solar cell module 10 from the viewpoint of adhesion. The polymer sheet 20 for a solar cell module of the present invention preferably has the easy adhesion layer 11 on the surface of the polyester support 18 opposite to the colored surface 19. Moreover, it is more preferable that the undercoat layer 12 is provided between the polyester support 18 and the easy-adhesion layer 11.
As shown in FIG. 2, an embodiment in which an overcoat layer 17 having the same composition as the colored layer and the main binder is provided adjacent to the colored layer is also preferable. In addition, when the overcoat layer 17 is provided, it is also preferable to provide an easy adhesion layer on the side opposite to the colored surface 19 of the polyester support 18 as shown in FIG.
Furthermore, as shown in FIG. 4, it is also preferable to provide a weather-resistant layer such as an aluminum sheet or a weather-resistant polyethylene terephthalate sheet on the easy-adhesion layer 11 of the polymer sheet 20 for the solar cell module of the present invention. Since an aluminum sheet, a weather-resistant polyethylene terephthalate sheet, and an easy-adhesion layer are often pasted through an adhesive, the easy-adhesion layer is preferably a functional layer that has good adhesion to the adhesive. In addition, when making the polymer sheet for solar cell modules of this invention into an aspect which has such a weather resistance layer, it may be called a back sheet for solar cell modules, and FIG. 4 shows the back sheet for solar cell modules of this invention. The preferable aspect of this is shown.

  FIG. 5 shows a preferred embodiment of the solar cell module of the present invention, and shows a preferred arrangement position of the polymer sheet for the solar cell module of the present invention in the solar cell module. In FIG. 5, an arrangement in which the colored layer 16 is on the inner side of the cell (on the sealing material 24 side) with respect to the polyester support 18 is cited as a preferred example, but the present invention is not limited to such an arrangement. That is, the colored layer 16 may be disposed on the inner side of the cell (on the sealing material 24 side) with respect to the polyester support 18 or may be disposed on the opposite side of the sealing material 24. In the solar cell module 10 of the present invention, a transparent front substrate 26 is preferably disposed on the side of the sealing material 24 opposite to the solar cell backsheet of the present invention.

  Hereinafter, a preferable aspect is demonstrated about each structural member which comprises the polymer sheet for solar cell modules of this invention.

<Polyester support>
The polymer sheet for solar cell modules of the present invention has a polyester support.
The polyester support 18 is preferably a sheet of heat-meltable polyester resin pellets formed by a melt film forming method or a solution film forming method. The kind of polyester resin used for the polyester support 18 is not particularly limited. The polyester support is preferable because it can maintain the adhesive force of the polymer sheet for solar cell module even after the wet heat aging by using a specific binder resin described later for the colored layer 16. Further, the surface of the polyester support may be subjected to a surface treatment from the viewpoint of improving coating properties, and for example, it is preferable to perform a corona treatment.

  The polyester is a linear saturated polyester synthesized from a derivative having the property of forming an aromatic dibasic acid or ester (hereinafter referred to as ester forming property) and a diol or an ester forming derivative thereof. Specific examples of such polyester include polyethylene terephthalate (PET), polyethylene isophthalate, polybutylene terephthalate (PBT), and polyethylene-2,6-naphthalate (PEN).

  In the polymer sheet for a solar cell module of the present invention, the polyester used as the support may be a homopolymer or a copolymer of the above-mentioned various polyesters. Furthermore, a small amount of other types of polymers such as polyimide may be blended with the polyester.

  In the present invention, among the above polyesters, PET and PEN are particularly preferable from the viewpoint of the balance between mechanical properties and cost.

  The polyester support in the present invention is preferably a solid phase polymerized after polymerization. Thereby, a preferable carboxyl group content can be achieved. Solid-phase polymerization may be a continuous method (a method in which a tower is filled with a resin, which is slowly heated for a predetermined time and then sent out), or a batch method (a resin is charged into a container). , A method of heating for a predetermined time). Specifically, for solid phase polymerization, Japanese Patent No. 2621563, Japanese Patent No. 3121876, Japanese Patent No. 3136774, Japanese Patent No. 3603585, Japanese Patent No. 3616522, Japanese Patent No. 3617340, Japanese Patent No. 3680523, Japanese Patent No. 3717392 are disclosed. The method described in Japanese Patent No. 4167159 can be applied.

  The temperature of the solid phase polymerization is preferably 170 ° C. or higher and 240 ° C. or lower, more preferably 180 ° C. or higher and 230 ° C. or lower, and further preferably 190 ° C. or higher and 220 ° C. or lower. The solid phase polymerization time is preferably 5 hours to 100 hours, more preferably 10 hours to 75 hours, and still more preferably 15 hours to 50 hours. The solid phase polymerization is preferably performed in a vacuum or in a nitrogen atmosphere.

  In the polymer sheet for a solar cell module of the present invention, the polyester support is preferably a biaxially stretched film. In the longitudinal direction stretching step, stretching is performed so that the length after stretching is 3 to 6 times that before stretching, and in the width direction stretching step, the width after stretching is 3 to 5 compared to before stretching in the width direction. It is preferable that it is stretched so as to be doubled. Furthermore, the polyester support may be preliminarily heat treated at 180 to 230 ° C. for 1 to 60 seconds.

  The thickness of the polyester support 18 is preferably in the range of 25 to 300 μm, more preferably 70 to 250 μm, and particularly preferably 90 to 200 μm. This is because this range is more preferable in terms of the balance between mechanical strength and cost.

The polyester support is preferably a polyester support having an elongation at break after aging for 48 hours in an atmosphere of 120 ° C. and relative humidity of 100% is 50% or more of the length of the polyester support before aging. . When such a polyester support is used, the polymer sheet for the solar cell module of the present invention also has an elongation at break after aging for 48 hours in an atmosphere of 120 ° C. and 100% relative humidity of 50% or more of the length before aging. It becomes easy to do.
Such a polyester support can be produced by, for example, performing the above-described solid phase polymerization after film formation.

<Colored layer>
The polymer sheet for a solar cell module of the present invention has a colored layer, the colored layer contains a binder made of an organic polymer, carbon black, and metal oxide fine particles, and the colored layer has the following formula (1): It is characterized by satisfying.
Formula (1)
1 ≦ W2 / W1 ≦ 10
(In Formula (1), W1 represents the content (unit: mass%) of carbon black in the colored layer, and W2 represents the content (unit: mass%) of metal oxide fine particles in the colored layer.) .

(Colored layer components)
-Binder resin for colored layer-
The polymer sheet for a solar cell module of the present invention contains a binder composed of an organic polymer.

The binder composed of the organic polymer is not particularly limited, but in the present invention, in the colored layer, the binder composed of the organic polymer is at least one selected from polyolefin resins and resins containing a styrene butadiene copolymer component. It is preferable to contain as a main component. The main component means a component occupying 50% or more in the binder resin of the colored layer. In the colored layer, the binder composed of the organic polymer is selected from a resin containing a polyolefin resin and a styrene-butadiene copolymer component. It is more preferable to include at least 70% by mass, and particularly preferable to include at least 80% by mass.

Examples of the olefin used in the polyolefin resin include those obtained by polymerizing ethylene, propylene, isobutylene and the like, and among them, ethylene is preferable. The acidic unit used for the polyolefin resin is preferably a unit derived from (meth) acrylic acid, particularly preferably a unit derived from (acrylic acid. In this specification, the acrylic resin is In addition, acrylate skeleton resins and methacrylate skeleton resins are included, and (meth) acrylic is a generic term for acrylic and methacrylic, and (meth) acrylate is a generic term for acrylate and methacrylate.
It is preferable that some or all of the acidic units of the polyolefin resin are neutralized with cations. The cation is preferably a metal such as sodium ion, zinc ion, magnesium ion, copper ion, lithium ion or potassium ion, an amine, or ammonia. As the metal ion, sodium ion, zinc ion and the like are preferable. As the amines or ammonia, triethylamine, N, N′-dimethylethanolamine, ammonia and the like are preferable.
The copolymerization ratio (molar ratio) between the olefin unit and the acid unit in the polyolefin resin is preferably 98: 2 to 80:20, and more preferably 96: 4 to 90:10.
As the polyolefin resin, for example, a polymer composed of polyethylene and acrylic acid or methacrylic acid is preferable.
The polyolefin resin preferably has a breaking elongation at 25 ° C. of about 500% to 1500%, more preferably about 600% to 1000%. The polyolefin resin preferably has a melting point of about 80 ° C. to 100 ° C., more preferably 90 ° C. to 95 ° C.
As the polyolefin resin, commercially available products may be used. For example, Arrow Base SE-1013N, SD-1010, TC, which is an aqueous dispersion of an ionomer for neutralizing an amine of an ethylene-acrylic acid copolymer. -4010, TD-4010 (both manufactured by Unitika Ltd.), Hitec S3148, S3121 and S8512 (both manufactured by Toho Chemical Co., Ltd.), which are water dispersions of ionomers of ethylene- (meth) acrylic acid copolymer, ethylene -Chemipearl S-120, S-75N, V100, EV210H (both manufactured by Mitsui Chemicals, Inc.), which are aqueous dispersions of sodium ionomer of acrylic acid copolymer, can be mentioned. Among them, in the present invention, it is preferable to use Arrow Base SE-1013N, manufactured by Unitika Ltd. from the viewpoint of adhesiveness. The arrow base SE-1013N has an elongation at break of about 900% and a melting point of about 93 ° C.

As the resin containing the styrene-butadiene copolymer component, for example, what is known as an SBR rubber resin is preferable. The copolymerization ratio (molar ratio) between the structural unit derived from the styrene monomer unit and the structural unit derived from the butadiene monomer unit in the resin containing the styrene-butadiene copolymer component is preferably 30:70 to 85:15, 35 : 65 to 80:20 is more preferable, and 40:60 to 70:30 is particularly preferable. If the styrene ratio exceeds 85 mol%, the colored layer may become too hard and the adhesion may be reduced. Conversely, if it is less than 30 mol%, the film strength of the colored layer may be reduced, and scratch resistance may be reduced. .
Further, in a resin containing a styrene-butadiene copolymer component in which three or more types of monomers are polymerized, the sum of the structural unit derived from the styrene monomer unit and the structural unit derived from the butadiene monomer unit is based on the entire copolymer. 60 to 99 mol%, preferably 85 to 99 mol%, more preferably 90 to 99 mol%.
The resin containing the styrene-butadiene copolymer component is obtained by polymerizing monomers containing 0.1 to 6% by mass of acrylic acid or methacrylic acid based on the sum of the contents of styrene and butadiene. More preferably, it is polymerized by containing acrylic acid or methacrylic acid in an amount of 0.2 to 5% by mass.
Furthermore, the resin containing the styrene-butadiene copolymer component contains 1-10% by mass of a copolymerizable monomer such as hydroxyethyl acrylate, methyl methacrylate, ethyl acrylate, acrylonitrile, etc. with respect to the total content of styrene and butadiene. It may be one that has been copolymerized to some extent.

The colored layer may contain, as other binder, polyethylene resin, polypropylene resin, ethylene vinyl acetate resin, ethylene acrylic acid copolymer resin, ethylene acrylic acid ester copolymer resin, acrylic resin, etc. It is also preferable to contain 80 to 0% by mass of an acrylic resin with respect to all binders in the layer.
The acrylic resin may be a homopolymer or a copolymer.
The structural unit contained in the acrylic resin is not particularly limited, and examples thereof include a structural unit having a carboxylic acid group and a structural unit having a carboxylic acid ester group.

  The content of the binder composed of the organic polymer in the colored layer is preferably 10 to 80% by mass, more preferably 10 to 70% by mass, and particularly preferably 15 to 60% by mass. .

  The binder resin used for the colored layer is preferably derived from a resin or emulsion contained in the coating solution as a polymer latex. Polymer latex refers to a state in which water-insoluble hydrophobic polymer fine particles are dispersed in a solvent (preferably water) such as a coating solution.

-Carbon black-
The polymer sheet for a solar cell module of the present invention is characterized in that the colored layer contains carbon black. By setting the addition amount of carbon black in such a range, the adhesion of the colored layer to the polyester support 18 can be improved through before and after wet heat aging.

  In the polymer sheet for a solar cell module of the present invention, the content W1 of carbon black in the colored layer is preferably 20% by mass or less, and is 18% by mass or less from the viewpoint of achieving both black density and insulation. Is more preferable, and it is especially preferable that it is 15 mass% or less. On the other hand, the content W1 of carbon black in the colored layer is preferably 3% by mass or more, more preferably 5% by mass or more from the viewpoint of achieving a sufficient black density in a somewhat thin colored layer. 7% by mass or more is particularly preferable.

  The colored layer preferably contains 10 to 100% by mass of carbon black with respect to the binder resin, preferably 20 to 80% by mass of carbon black, and 35 to 75% by mass of carbon black. It is more preferable to contain. It is preferable that the carbon black is included in a range equal to or higher than the lower limit value of the above range from the viewpoint of sufficiently imparting blackness, and that the carbon black is included in a range equal to or lower than the upper limit value of the above range, It is preferable from the viewpoint of improvement.

In the present invention, carbon black particles are preferably used as the carbon black in order to obtain a high coloring power in a small amount, more preferably carbon black particles having a particle size of 1 μm or less, and a particle size of 0. Particularly preferred are carbon black particles of 1 to 0.8 μm. Furthermore, it is preferable to use carbon black particles dispersed in water together with a dispersant.
Carbon black that can be obtained commercially can be used, for example, MF-5630 Black (manufactured by Dainichi Seika Co., Ltd.) or JP-A-2009-13287, paragraph [0035]. Those described can be used.

-Metal oxide fine particles-
The polymer sheet for a solar cell module of the present invention is characterized in that the colored layer contains metal oxide fine particles, and the colored layer satisfies the following formula (1).
Formula (1)
1 ≦ W2 / W1 ≦ 10
(In Formula (1), W1 represents the content (unit: mass%) of carbon black in the colored layer, and W2 represents the content (unit: mass%) of metal oxide fine particles in the colored layer.)
By satisfy | filling said Formula (1), the polymer sheet for solar cell modules of this invention can make black density and insulation compatible, even if a colored layer is comparatively thin film thickness. Furthermore, the polymer sheet for solar cell module of the present invention preferably has improved scratch resistance of the colored layer.
The lower limit of the formula (1) is preferably 1.5 or more, more preferably 2 or more, and particularly preferably 2.5 or more. On the other hand, the upper limit value of the formula (1) is preferably 8 or less, more preferably 6 or less, particularly preferably 5 or less, and particularly preferably 4.5 or less.

In the polymer sheet for a solar cell module of the present invention, it is preferable that the metal oxide fine particles include at least one of white metal oxide fine particles and black metal oxide fine particles.
As the white metal oxide, titanium oxide, aluminum oxide, zinc oxide, silica and the like are preferable, and among these, titanium oxide and silica are more preferable.
As the black metal oxide, a black composite metal oxide is preferable.
In the polymer sheet for a solar cell module of the present invention, the metal oxide fine particles preferably include at least one selected from titanium oxide, black composite metal oxide, and silicon dioxide.
Here, the black composite metal oxide is preferably a composite metal oxide containing at least one of iron, manganese, cobalt, chromium and copper, and two or more of cobalt, chromium, iron, manganese and copper Is more preferable, and at least one pigment selected from PBk26, PBk27, and PBk28 is more particularly preferable.
The pigment of PBk26 is a complex oxide of iron, manganese and copper, the pigment of PBk-27 is a complex oxide of iron, cobalt and chromium, and PBk-28 is a complex oxide of copper, chromium and manganese. It is.
In the polymer sheet for a solar cell module of the present invention, the metal oxide fine particles preferably contain at least one metal selected from titanium, cobalt, chromium, iron, manganese, copper, and silicon.

In the polymer sheet for a solar cell module of the present invention, the metal oxide fine particles preferably include at least one white metal oxide fine particle, and at least one white metal oxide fine particle and at least one black composite are included. It is more preferable from the viewpoint of coloring density that both metal oxides are included.
The metal oxide fine particles are preferably used in combination with the white metal oxide fine particles from the viewpoint of obtaining a high color density by using the white metal oxide fine particles, rather than using the black composite metal oxide alone.
Although there is no restriction | limiting in particular as a content rate of the said white metal oxide fine particle and the said black composite metal oxide, The said black composite metal oxide is 0-200 mass% with respect to the said white metal oxide fine particle. It is preferably contained, more preferably 0 to 120% by mass, more preferably 30 to 120% by mass, and particularly preferably 30 to 80% by mass.

  The particle diameter of the metal oxide fine particles is preferably 0.03 μm to 15 μm, and more preferably 0.05 μm to 10 μm.

  The mass content of the metal oxide fine particles in the colored layer is preferably 5% or more and 70% or less, and more preferably 10% or more and 60% or less.

-Crosslinking agent-
The colored layer preferably contains a structure derived from a crosslinking agent formed by adding a crosslinking agent for the purpose of imparting film strength. Examples of preferred crosslinking agents include oxazoline compounds, carbodiimide compounds, epoxy compounds, melamine resins and the like.

  Among these, the crosslinking agent is preferably at least one crosslinking agent selected from an oxazoline crosslinking agent, a carbodiimide crosslinking agent, and a melamine crosslinking agent, more preferably an oxazoline compound and a carbodiimide compound, and an oxazoline compound Is particularly preferred.

There are various commercially available oxazoline compounds. For example, Epocros K2010E, K2020E, K2030E, WS500, and WS700 (all manufactured by Nippon Shokubai Chemical Co., Ltd.) can be used.
There are also commercially available carbodiimide compounds, and carbodilite V-02, V-02-L2, V-04, and E-02 (all of which are Nisshinbo Co., Ltd.) can be used.
As other crosslinking agents, 2,4-dichloro-6-hydroxy-1,3,5-triazine sodium salt and the like can be used.

  It is preferable that the structure derived from the crosslinking agent in the colored layer is contained in an amount of 0.5 to 80% by mass with respect to the total polymer resin in the colored layer, and 2 to 60% by mass is contained. More preferably, it is especially preferable that 5-40 mass% is contained. It is preferable from a planar viewpoint that the structure derived from the crosslinking agent in the colored layer is contained in an amount of 80% by mass or less with respect to the total polymer resin in the colored layer, and 0.5% by mass or more is contained. It is preferable from the viewpoint of adhesion after wet heat aging. The preferred addition amount varies depending on the type of the crosslinking agent.

-Filler-
The polymer sheet for a solar cell module of the present invention preferably contains a filler in the colored layer from the viewpoint of film strength and adhesion. The filler contained in the colored layer is preferably 1 to 150% by mass, more preferably 2 to 100% by mass, and particularly preferably 5 to 50% by mass with respect to the total polymer resin in the colored layer.
More preferably, the filler is an inorganic filler. Specifically, examples of the inorganic filler include inorganic fillers other than the metal oxide fine particles. For example, particles such as talc, calcium carbonate, magnesium carbonate, barium sulfate, aluminum hydroxide, kaolin, and clay are used. Preferably mentioned.

-Dispersion stabilizer-
Furthermore, in order to suppress aggregation of carbon black in water, a dispersion stabilizer may be added to the colored layer aqueous dispersion.
As the dispersion stabilizer, various surfactants and water-soluble resins are used. In particular, a low-molecular water-soluble resin is preferable, and polyvinyl alcohol, cellulose, polyacrylic acid, or a derivative thereof can be used.
As the surfactant, a known surfactant such as an anionic or nonionic surfactant can be used.

-Slip agent-
The colored layer preferably contains a slip agent from the viewpoint of improving the scratch resistance of the colored layer. Although there is no restriction | limiting in particular as said sliding agent, Among these, it is more preferable to use an organic type lubricant.

The organic lubricant is preferably contained in the range of 0.2~500mg / m ² in the colored layer. When the content ratio of the organic lubricant is 0.2 mg / m ² or more, the scratch resistance is sufficiently improved by the effect of reducing the dynamic friction coefficient due to the inclusion of the organic lubricant. Further, when the content ratio of the organic lubricant is 500 mg / m ² or less, coating unevenness and aggregates are less likely to occur when the colored layer is formed by coating, and repelling failure is less likely to occur.
Among the above range, in view of the dynamic friction coefficient reduction effect and coating suitability, and more preferably from ^{1mg / m 2 ~300mg / m 2} , the range of 5mg / m ² ~200mg / m ² is particularly preferred, 10 mg / m The range of ^{2 to} 150 mg / m ² is more particularly preferable.

  Examples of the organic lubricant include synthetic wax compounds, natural wax compounds, surfactant compounds, inorganic compounds, and organic resin compounds. Among them, in the polymer sheet of the present invention, the organic lubricant contained in the colored layer is a polyolefin compound, a synthetic wax compound, a natural wax compound, and a surfactant in terms of the surface strength of the colored layer. It is preferably at least one selected from system compounds.

  Examples of the polyolefin compound include olefin waxes such as polyethylene wax and polypropylene wax.

  Examples of the synthetic wax-based compounds include stearic acid, oleic acid, erucic acid, lauric acid, behenic acid, palmitic acid, adipic acid and other esters, amides, bisamides, ketones, metal salts and derivatives thereof, Fischer-Tropsch wax and the like ( Examples include synthetic hydrocarbon waxes (other than olefin waxes), phosphate esters, hydrogenated castor oil, hydrogenated waxes of hydrogenated castor oil derivatives, and the like.

  Examples of the natural wax compounds include plant waxes such as carnauba wax, candelilla wax and wood wax, petroleum waxes such as paraffin wax and microcrystalline wax, mineral waxes such as montan wax, animals such as beeswax and lanolin. And waxes.

  Examples of the surfactant compound include a cationic surfactant such as an alkylamine salt, an anionic surfactant such as an alkyl sulfate ester salt, a nonionic surfactant such as polyoxyethylene alkyl ether, and an alkylbetaine. Amphoteric surfactants, fluorosurfactants and the like.

The organic lubricant may be a commercially available product, specifically,
Examples of the organic lubricant of the polyolefin compound include Chemipearl series (for example, Chemipearl W700, W900, W950, etc.) manufactured by Mitsui Chemicals, and Polylon P-502 manufactured by Chukyo Yushi Co., Ltd. ,
Examples of synthetic wax-based organic lubricants include, for example, High Micron L-271, Hydrin L-536 manufactured by Chukyo Yushi Co., Ltd.
Examples of natural wax-based organic lubricants include, for example, Hydrin L-703-35, Cellosol 524, Cellosol R-586 manufactured by Chukyo Yushi Co., Ltd.
Examples of surfactant-based organic lubricants include the NIKKOL series (for example, NIKKOL SCS, etc.) manufactured by Nikko Chemicals Co., Ltd., and the Emar series (for example, Emar 40, etc.) manufactured by Kao Corporation.

  Among the above, it is preferable to add a natural wax-based organic lubricant as the organic lubricant from the viewpoint of scratch resistance and surface improvement, and among them, it is more preferable to use Cellosol 524.

(Characteristics of colored layer)
If the colored layer is formed by coating a fixed coating amount of the total of the binder resin is preferably 0.5~7g / m ^2, more be a 0.6~5g / m ² preferable.

  The thickness of the colored layer is preferably 0.3 to 6 μm, more preferably 0.3 to 4 μm, particularly preferably 0.5 to 4 μm, and particularly preferably 1.5 to 4 μm. And even more particularly preferably 2.0 to 3.5 μm, even more particularly preferably more than 2.5 μm and 3.5 μm. By setting the thickness of the colored layer 16 to 0.3 μm or more, the carbon black content can be sufficiently increased, and adjustment can be easily performed so that a sufficient black density can be obtained. By setting the thickness of the colored layer 16 to 6 μm or less, when the colored layer is formed by coating, the amount of the binder is not increased excessively, and it becomes easy to coat with a uniform film thickness. Scratch resistance can be improved. The colored layer of the polymer sheet for the solar cell module can be thinned by coating, and it is preferable from the viewpoint of reducing the environmental load due to resource saving that the thickness is not more than the upper limit.

<Overcoat layer>
The polymer sheet for a solar cell module may have an overcoat layer on the colored layer. By providing the overcoat layer in this manner, the polymer sheet for the solar cell module can have excellent adhesion to the adhesive or the sealing material, and can improve scratch resistance and increase surface resistance.

  The resin used for the overcoat layer is a resin having good adhesiveness with an adhesive such as urethane resin or a sealing material such as ethylene vinyl acetate copolymer resin. Specifically, the overcoat layer is It is preferable to contain at least one binder selected from resins containing 20 to 100% by mass of a polyolefin resin and a styrene-butadiene copolymer component with respect to the total binder in the overcoat layer.

  As the resin used for the overcoat layer, other binders may be used in addition to the above binder.

  It is preferable to use a crosslinking agent in the overcoat layer in addition to the resin. As the crosslinking agent used in the overcoat layer, carbodiimide-based and oxazoline-based crosslinking agents are preferable. Preferred ranges of the carbodiimide-based and oxazoline-based crosslinking agents used for the overcoat layer are the same as the preferred ranges of the carbodiimide-based and oxazoline-based crosslinking agents used for the colored layer.

  In addition, it is preferable to add waxes to the overcoat layer in order to improve surface slipperiness and scratch resistance. Examples of the waxes used for the overcoat layer include the same waxes as those used for the colored layer, and among them, natural waxes such as carnauba wax are particularly preferable.

  The thickness of the overcoat layer is preferably 0.1 to 2 μm, and more preferably 0.3 to 1.5 μm. When the thickness of the overcoat layer is 0.1 μm or more, it can contribute to an improvement in scratch resistance and an increase in surface resistance, and an effect of improving the adhesion between the colored layer and the sealant can be further obtained. When the thickness of the overcoat layer is 2 μm or less, a sufficient effect of improving the adhesion between the colored layer and the adhesive can be obtained while reducing the manufacturing cost.

<Undercoat layer>
The polymer sheet for a solar cell module of the present invention has a surface on the side opposite to the surface on which the colored layer of the polyester support is provided, and improves adhesion between an easy-adhesion layer described later and the polyester support. From the viewpoint, an undercoat layer may be provided.
The undercoat layer is not particularly limited, and a known undercoat layer can be used.
The undercoat layer preferably has a thickness of 2 μm or less, more preferably 0.02 μm to 2 μm, and still more preferably 0.04 μm to 1.5 μm. When the thickness is 2 μm or less, the planar shape can be kept good. Moreover, it is easy to ensure required adhesiveness because thickness is 0.02 micrometer or more.

The undercoat layer preferably contains a polyolefin resin, an acrylic resin, or the like.
As the polyolefin resin, for example, a polymer composed of polyethylene and acrylic acid or methacrylic acid is preferable. Commercially available products may be used as the polyolefin resin. For example, Arrow Base SE-1013N, SD-1010, TC-4010, TD-4010 (both manufactured by Unitika Ltd.), Hitech S3148, S3121, S8512 (both manufactured by Toho Chemical Co., Ltd.), Chemipearl S-120, S-75N, V100, EV210H (both manufactured by Mitsui Chemicals, Inc.) and the like. Among them, in the present invention, it is preferable to use Arrow Base SE-1013N manufactured by Unitika Ltd.
As the acrylic resin, for example, a polymer containing polymethyl methacrylate, polyethyl acrylate, or the like is preferable. As the acrylic resin, a commercially available product may be used. For example, AS-563A (manufactured by Daicel Einchem Co., Ltd.) can be preferably used.
These polymers may be used alone or in combination of two or more, and a combination of an acrylic resin and a polyolefin resin is preferable.

The undercoat layer preferably contains a crosslinking agent.
Examples of the crosslinking agent used for the undercoat layer include epoxy-based, isocyanate-based, melamine-based, carbodiimide-based, and oxazoline-based crosslinking agents. The preferred range of the crosslinking agent that can be used for the undercoat layer is the same as the range of the crosslinking agent used for the colored layer.

  The undercoat layer preferably contains an anionic or nonionic surfactant. The range of the surfactant that can be used for the undercoat layer is the same as the range of the surfactant that can be used for the colored layer. Of these, nonionic surfactants are preferred.

  The undercoat layer preferably contains a filler. The filler contained in the colored layer is preferably 20 to 300% by mass, more preferably 40 to 230% by mass, and particularly preferably 60 to 170% by mass with respect to the total polymer resin in the colored layer. The kind of filler that can be used for the undercoat layer is the same as the kind of filler that can be used for the colored layer.

<Easily adhesive layer>
The polymer sheet for a solar cell module of the present invention is preferably provided with an easy-adhesion layer on the surface on which the undercoat layer of the polyester support is provided for the purpose of improving adhesion with an adhesive such as a urethane resin. .
As the binder used for the easy-adhesion layer, a binder mainly composed of an acrylic resin, a polyurethane resin, a polyolefin resin or the like is preferable. As the acrylic resin preferably used for the easy-adhesion layer, a copolymer with a monomer such as methacrylic acid ester, acrylic acid ester, methacrylic acid or acrylic acid is preferable. The polyurethane resin is preferably a urethane resin such as polyester or polycarbonate. As polyolefin resin, the polyolefin resin used for the said colored layer can be mentioned. Preferred examples of the binder include Arrow Base SE-1013N, Chemipearl S-120, S-75N (both manufactured by Mitsui Chemicals, Inc.) and the like as specific examples of polyolefin.
The binder content in the easy-adhesion layer is preferably in the range of 0.02 to 5 g / m ² . Especially, the range of 0.04-3g / m < ² > is more preferable. The content of the binder, 0.05 g / m ² or more is desired as easy adhesion obtained to that, better surface state is obtained when the is 5 g / m ² or less.
A cross-linking agent is preferably added to the easy adhesion layer for the purpose of imparting film strength, and an oxazoline cross-linking agent, a carbodiimide cross-linking agent, an epoxy cross-linking agent, and a melamine cross-linking agent are preferable.
A surfactant is preferably added to the easy-adhesion layer from the viewpoint of improving coatability.
The adhesion of the easy-adhesion layer to the urethane adhesive is preferably 2 N / cm or more, preferably more than 4 N / cm, and more preferably 5 to 150 N / cm.

<Physical properties and characteristics of polymer sheet for solar cell module>
(Surface resistivity)
The polymer sheet for solar cell modules of the present invention is excellent in insulation. In the polymer sheet for a solar cell module of the present invention, the electric resistance of the colored layer is preferably 10 ¹¹ Ω / □ or more, more preferably 10 ¹² Ω / □ or more, and particularly preferably 10 ¹³ Ω / □ or more as the surface resistance. 10 ¹⁴ Ω / □ or more is more preferable.

(Transparent OD)
In the polymer sheet for a solar cell module of the present invention, the transmission OD of the entire sheet is preferably 1 to 2.5, and more preferably 1.5 to.

(Film thickness)
The polymer sheet for a solar cell module of the present invention preferably has a film thickness of 150 to 400 μm, more preferably 200 to 350 μm, and particularly preferably 220 to 280 μm.

<Method for producing polymer sheet for solar cell module>
The method for producing the polymer sheet 20 for the solar cell module of the present invention is not particularly limited, but it is preferably formed by applying a coating solution for each layer to the polyester support.
For example, at least one surface side of the polyester support contains a binder composed of the organic polymer, carbon black, and metal oxide fine particles, and the colored layer is prepared so as to satisfy the formula (1). It is preferable to include the process of apply | coating the coating liquid for colored layers.
Furthermore, it is preferable to have the process of heating and drying the said coating film.

  In the coating step, a known coating machine may be appropriately selected according to the purpose and applied. For example, the application | coating by a spin coater, a roll coater, a bar coater, and a curtain coater is mentioned.

  In the heat-drying of the applied coating solution, heating is performed with a heater so that the temperature of each coating film is at least 100 ° C., that is, 100 ° C. or higher, more preferably 130 ° C. or higher.

[Back sheet for solar cell module]
The back sheet for a solar cell module of the present invention comprises the polymer sheet for a solar cell module of the present invention.
The back sheet for a solar cell module preferably includes a weather resistant layer on at least one surface of the polymer sheet for the solar cell module of the present invention, and more preferably includes a weather resistant layer on the easy adhesion layer.
There is no restriction | limiting in particular as said weather resistant layer, A well-known weather resistant layer can be used. As the weather-resistant layer, for example, an aluminum sheet or a weather-resistant polyethylene terephthalate sheet can be preferably used. The weather resistant layer may have a laminated structure of two or more layers, and for example, a laminate of an aluminum sheet or a weather resistant polyethylene terephthalate sheet can be used.

[Solar cell module]
The polymer sheet for a solar cell module of the present invention is suitable for production of a solar cell module.
In the solar cell module, for example, a solar cell element that converts sunlight light energy into electric energy is disposed between the transparent substrate on which sunlight is incident and the solar cell backsheet of the present invention described above. The substrate and the backsheet are sealed with a sealing material such as an ethylene-vinyl acetate copolymer.

The members other than the solar cell module, the solar cell, and the back sheet are described in detail in, for example, “Photovoltaic power generation system constituent material” (supervised by Eiichi Sugimoto, Kogyo Kenkyukai, published in 2008).
The solar cell module of the present invention is bonded to a solar cell element, a sealing material that seals the solar cell element, a sealing material, a surface protection member that protects the light receiving surface side, and a sealing material, A back surface protection member that protects the side opposite to the light receiving surface, the sealing material includes an ethylene-vinyl acetate copolymer (EVA), and a polymer sheet for a solar cell module is used as the back surface protection member. It can be set as the structure which the coloring layer of the polymer sheet for modules adhered directly with the sealing material. If it is such a solar cell module, even if the solar cell backsheet is in a wet heat environment with EVA, it can be in close contact over a long period of time, and a long-life solar cell module can be obtained.

  The transparent front substrate may be appropriately selected from base materials that transmit light as long as the transparent front substrate has light transmittance through which sunlight can pass. From the viewpoint of power generation efficiency, the higher the light transmittance, the better. For such a substrate, for example, a glass substrate, a transparent resin such as an acrylic resin, or the like can be suitably used.

  Examples of the solar cell element include silicon-based materials such as single crystal silicon, polycrystalline silicon, and amorphous silicon, and group III-V such as copper-indium-gallium-selenium, copper-indium-selenium, cadmium-tellurium, and gallium-arsenic. Various known solar cell elements such as II-VI group compound semiconductor systems can be applied.

  The present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the examples shown below.

[Production Example 1]
<Preparation of support 1>
-Synthesis of polyester-
A slurry of 100 kg of high-purity terephthalic acid (manufactured by Mitsui Chemicals) and 45 kg of ethylene glycol (manufactured by Nippon Shokubai Co., Ltd.) is charged with about 123 kg of bis (hydroxyethyl) terephthalate in advance, at a temperature of 250 ° C. and a pressure of 1.2 The esterification reaction tank maintained at × 10 ⁵ Pa was sequentially supplied over 4 hours, and the esterification reaction was further performed over 1 hour after the completion of the supply. Thereafter, 123 kg of the obtained esterification reaction product was transferred to a polycondensation reaction tank.

Subsequently, 0.3% by mass of ethylene glycol was added to the polycondensation reaction tank to which the esterification reaction product had been transferred, based on the resulting polymer. After stirring for 5 minutes, an ethylene glycol solution of cobalt acetate and manganese acetate was added to 30 ppm and 15 ppm, respectively, with respect to the resulting polymer. After further stirring for 5 minutes, a 2% by mass ethylene glycol solution of a titanium alkoxide compound was added to 5 ppm with respect to the resulting polymer. Five minutes later, a 10% by mass ethylene glycol solution of ethyl diethylphosphonoacetate was added so as to be 5 ppm with respect to the resulting polymer. Thereafter, while stirring the low polymer at 30 rpm, the reaction system was gradually heated from 250 ° C. to 288 ° C. and the pressure was reduced to 40 Pa. The time to reach the final temperature and final pressure was both 60 minutes. When the predetermined stirring torque was reached, the reaction system was purged with nitrogen, returned to normal pressure, and the polycondensation reaction was stopped. And it discharged to cold water in the shape of a strand, and it cut immediately, and produced the polymer pellet (about 3 mm in diameter, about 7 mm in length). The time from the start of decompression to the arrival of the predetermined stirring torque was 3 hours.
However, the titanium alkoxide compound used was the titanium alkoxide compound (Ti content = 4.44% by mass) synthesized in Example 1 of paragraph No. [0083] of JP-A-2005-340616.

-Base formation-
The pellets obtained as described above were melted at 280 ° C. and cast on a metal drum to prepare an unstretched base having a thickness of about 2.5 mm. Thereafter, the film was stretched 3 times in the longitudinal direction at 90 ° C., and further stretched 3.3 times in the transverse direction at 120 ° C. Thereafter, heat treatment was further performed at 225 ° C. for 4 minutes. Thus, a biaxially stretched polyethylene terephthalate support (hereinafter referred to as “support 1”) having a thickness of 250 μm was obtained.

[Example 1]
A colored layer was formed on both sides of the support 1 produced in Production Example 1 by the following method to produce a polymer sheet 20 for a solar cell module having the configuration shown in FIG.

<Colored layer>
-Preparation of coating solution for forming colored layer-
Each component in the following composition was mixed to prepare a coating solution for forming a colored layer.
(Composition of the coating solution for forming the colored layer in Example 1)
-Carbon black aqueous dispersion: 72.2 parts by mass (manufactured by Dainichi Seika Co., Ltd. MF-5630 black, solid content: 31.5%)
・ Polyolefin binder (Binder A): 225.2 parts by mass (manufactured by Unitika Ltd., Arrow Base SE1013N, solid content: 20% by mass)
・ Oxazoline compound (crosslinking agent) 43.1 parts by mass (Epocross WS700, 25% solids aqueous dispersion manufactured by Nippon Shokubai Co., Ltd.)
Surfactant a: 13.0 parts by mass (manufactured by Sanyo Chemical Industries, NAROACTY CL-95, 5% aqueous solution)
Surfactant b: 16.3 parts by mass (1% aqueous solution of the following fluorosurfactant)
・ Sliding agent: 109.2 parts by mass (manufactured by Chukyo Yushi Co., Ltd., Cerazole 524, 3% aqueous dispersion)
Metal oxide fine particle S: 170.6 parts by mass (silica fine particle, manufactured by Nissan Chemical Co., Ltd., Snowtex ZL, 40% by mass)
Preservative C: 0.5 part by mass (the following compound, 3.5% by mass methanol solution)
・ Distilled water ... 349.9 parts by mass

Surfactant b: Sodium = bis (3,3,4,4,5,5,6,6-nonafluoro) = 2-sulfonite oxysuccinate Preservative C: 1,2-benzothialyzol-3-one

-Formation of colored layer-
One surface of the support 1 was subjected to corona treatment at a treatment strength of 730 J / m ² .
The colored layer forming coating solution obtained above is applied to the corona-treated surface of the support 1 so that the solid amount coating amount is 2.72 g / m ^2, and dried at 150 ° C. for 1 minute. Formed.
Thus, an adjacent colored layer was formed on one surface of the support 1 (hereinafter referred to as “colored layer surface”).

<Easily adhesive layer>
The surface opposite to the colored layer surface of the support 1 coated with the colored layer was subjected to a corona discharge treatment under the condition of 730 J / m ² while being conveyed at a conveying speed of 105 m / min.

-Formation of the first layer (undercoat layer)-
A coating film 1 is obtained by applying the following first layer coating solution (1) on one side of the support 1 subjected to corona discharge treatment so that the dry mass becomes 142 mg / m ² by the bar coating method. The membrane 1 was dried at 160 ° C. for 1 minute to form a first layer (undercoat layer) having a thickness of 0.07 μm.

-Preparation of first layer coating solution (1)-
-Polyacrylic binder (binder) 21.5 parts by mass [manufactured by Toagosei Co., Ltd., Jurimer ET-410, solid content 30%]
-Carbodiimide compound (carbodiimide crosslinking agent) 8.9 parts by mass [Nisshinbo Chemical Co., Ltd., Carbodilite V-02-L2, solid content 20%]
-Surfactant a 15.0 parts by mass [manufactured by Sanyo Chemical Industries, 1% aqueous solution of NAROACTY CL-95]
・ Inorganic filler (inorganic fine particles) 40.1 parts by mass [Mitsubishi Materials Electronics Chemical Co., Ltd., SDL-2, tin oxide 20% aqueous solution]
・ Distilled water added so that the whole becomes 1,000 parts by mass

-Formation of second layer (adhesive layer)-
On the first layer thus obtained, so that the dry weight is 30.9 mg / m ^2, after obtaining the coating film 2 was applied by bar coating the following Coating Solution for Second Layer (1), the coating The film 2 was dried at 170 ° C. for 1 minute to form a second layer (an easily adhesive layer) having a thickness of 0.03 μm.

-Preparation of second layer coating solution (1)-
-Polyacrylic binder (resin binder) 10.0 parts by mass [manufactured by Toagosei Co., Ltd., Jurimer ET-410, solid content 30%]
Carbodiimide compound (carbodiimide cross-linking agent) 4.0 parts by mass [Nisshinbo Chemical Co., Ltd., Carbodilite V-02-L2, solid content 20%]
・ Carnauba wax (main component: myricyl cellotate CH ₃ (CH ₂ ) ₂₄ COO (CH ₂ ) ₂₉ CH ₃ , freezing point 82 ° C.)
[Chukyo Yushi Co., Ltd., Cellosol 524, solid content 30%] 1.33 parts by mass / surfactant a 21.0 parts by mass [Sanyo Chemical Industries, Ltd., 1% aqueous solution of NAROACTY CL-95]
・ Distilled water added so that the whole becomes 1,000 parts by mass

  As described above, a colored layer is formed on one side of the support 1, and the first layer (coating layer) is formed in order from the support 1 side on the surface opposite to the side on which the colored surface of the support 1 is formed. And the polymer sheet for solar cell modules of Example 1 by which the 2nd layer (easy-adhesive layer) was laminated | stacked was obtained.

[Example 2]
A polymer sheet for a solar cell module of Example 2 was obtained in the same manner as in Example 1 except that the colored layer forming coating solution was changed to the following.

-Preparation of coating solution for forming colored layer-
Each component in the following composition was mixed to prepare a coating solution for forming a colored layer.
(Composition of the colored layer forming coating solution in Example 2)
-Carbon black aqueous dispersion: 72.2 parts by mass (manufactured by Dainichi Seika Co., Ltd. MF-5630 black, solid content: 31.5%)
Polyolefin binder (Binder A) 321.8 parts by mass (produced by Unitika Ltd., Arrow Base SE1013N, solid content 20% by mass)
Oxazoline compound (crosslinking agent) 61.6 parts by mass (Epocross WS700, 25% solids aqueous dispersion manufactured by Nippon Shokubai Co., Ltd.)
Surfactant a: 13.0 parts by mass (manufactured by Sanyo Chemical Industries, NAROACTY CL-95, 5% aqueous solution)
Surfactant b: 16.3 parts by mass (1% aqueous solution of the fluorosurfactant)
・ Sliding agent: 156.0 parts by mass (manufactured by Chukyo Yushi Co., Ltd., Cerazole 524, 3% aqueous dispersion)
・ Metal oxide fine particles S: 243.8 parts by mass (silica fine particles, manufactured by Nissan Chemical Co., Ltd., Snowtex ZL, 40% by mass)
Preservative C: 0.7 parts by mass (the compound, a 3.5% by mass methanol solution)
・ Distilled water ... 114.7 parts by mass

[Example 3]
A polymer sheet for a solar cell module of Example 3 was obtained in exactly the same manner as in Example 1 except that the color layer coating solution was changed to the following.

-Preparation of coating solution for forming colored layer-
Each component in the following composition was mixed to prepare a coating solution for forming a colored layer.
(Composition of the coating solution for forming the colored layer in Example 3)
-Carbon black aqueous dispersion: 72.2 parts by mass (manufactured by Dainichi Seika Co., Ltd. MF-5630 black, solid content: 31.5%)
Polyolefin binder (Binder A): 160.9 parts by mass (produced by Unitika Ltd., Arrow Base SE1013N, solid content 20% by mass)
-Styrene butadiene resin (binder B) ... 67.7 parts by mass (Nippol Latex LX407C4E, 43% solid content, manufactured by Nippon Zeon Co., Ltd.)
Oxazoline compound (crosslinking agent) 61.6 parts by mass (Epocross WS700, 25% solids aqueous dispersion manufactured by Nippon Shokubai Co., Ltd.)
Surfactant a: 13.0 parts by mass (manufactured by Sanyo Chemical Industries, NAROACTY CL-95, 5% aqueous solution)
Surfactant b: 16.3 parts by mass (1% aqueous solution of the fluorosurfactant)
・ Sliding agent: 156.0 parts by mass (manufactured by Chukyo Yushi Co., Ltd., Cerazole 524, 3% aqueous dispersion)
・ Metal oxide fine particles S: 243.8 parts by mass (silica fine particles, manufactured by Nissan Chemical Co., Ltd., Snowtex ZL, 40% by mass)
Preservative C: 0.7 parts by mass (the compound, a 3.5% by mass methanol solution)
・ Distilled water ... 114.7 parts by mass

[Example 4]
A polymer sheet for a solar cell module of Example 4 was obtained in exactly the same manner as in Example 1 except that the color layer coating solution was changed to the following.
-Preparation of coating solution for forming colored layer-
Each component in the following composition was mixed to prepare a coating solution for forming a colored layer.
(Composition of the colored layer forming coating solution in Example 4)
-Carbon black aqueous dispersion: 72.2 parts by mass (manufactured by Dainichi Seika Co., Ltd. MF-5630 black, solid content: 31.5%)
-Styrene butadiene resin (Binder B) 135.4 parts by mass (Nippol Latex LX407C4E, 43% solid content, manufactured by Nippon Zeon Co., Ltd.)
Oxazoline compound (crosslinking agent) 61.6 parts by mass (Epocross WS700, 25% solids aqueous dispersion manufactured by Nippon Shokubai Co., Ltd.)
Surfactant a: 13.0 parts by mass (manufactured by Sanyo Chemical Industries, NAROACTY CL-95, 5% aqueous solution)
Surfactant b: 16.3 parts by mass (1% aqueous solution of the fluorosurfactant)
・ Sliding agent: 156.0 parts by mass (manufactured by Chukyo Yushi Co., Ltd., Cerazole 524, 3% aqueous dispersion)
・ Metal oxide fine particles S: 243.8 parts by mass (silica fine particles, manufactured by Nissan Chemical Co., Ltd., Snowtex ZL, 40% by mass)
Preservative C: 0.7 parts by mass (the compound, a 3.5% by mass methanol solution)
・ Distilled water ... 114.7 parts by mass

[Example 5]
A polymer sheet for a solar cell module of Example 5 was obtained in exactly the same manner as in Example 1 except that the color layer coating solution was changed to the following.
-Preparation of coating solution for forming colored layer-
Each component in the following composition was mixed to prepare a coating solution for forming a colored layer.
(Composition of colored layer forming coating solution in Example 5)
-Carbon black aqueous dispersion: 71.4 parts by mass (manufactured by Dainichi Seika Co., Ltd. MF-5630 black, solid content: 31.5%)
・ Polyolefin binder (Binder A): 563.1 parts by mass (manufactured by Unitika Ltd., Arrow Base SE1013N, solid content: 20% by mass)
・ Oxazoline compound (crosslinking agent) 107.7 parts by mass (Epocross WS700 manufactured by Nippon Shokubai Co., Ltd. 25% aqueous dispersion)
Surfactant a: 18.0 parts by mass (manufactured by Sanyo Chemical Industries, NAROACTY CL-95, 5% aqueous solution)
Surfactant b: 9.0 parts by mass (1% aqueous solution of the fluorosurfactant)
・ Metal oxide fine particle dispersion T: 137.2 parts by mass (49 mass% aqueous solution of the following titanium oxide dispersion)
Preservative C: 0.9 parts by mass (the above compound, 3.5% by mass methanol solution)
・ Distilled water ... 92.7 parts by mass

-Preparation of titanium oxide dispersion-
A titanium oxide dispersion was prepared using titanium oxide CR95 manufactured by Ishihara Sangyo Co., Ltd.

[Example 6]
A polymer sheet for a solar cell module of Example 6 was obtained in exactly the same manner as in Example 1 except that the color layer coating solution was changed to the following.
-Preparation of coating solution for forming colored layer-
Each component in the following composition was mixed to prepare a coating solution for forming a colored layer.
(Composition of the coating solution for forming the colored layer)
-Carbon black aqueous dispersion: 71.4 parts by mass (manufactured by Dainichi Seika Co., Ltd. MF-5630 black, solid content: 31.5%)
Polyolefin binder (Binder A) 281.5 parts by mass (produced by Unitika Ltd., Arrow Base SE1013N, solid content 20% by mass)
Styrene butadiene resin (Binder-B): 118.5 parts by mass (Nippol Latex LX407C4E, solid content: 43%, manufactured by Nippon Zeon Co., Ltd.)
・ Oxazoline compound (crosslinking agent) 107.7 parts by mass (Epocross WS700 manufactured by Nippon Shokubai Co., Ltd. 25% aqueous dispersion)
Surfactant a: 18.0 parts by mass (manufactured by Sanyo Chemical Industries, NAROACTY CL-95, 5% aqueous solution)
Surfactant b: 9.0 parts by mass (1% aqueous solution of the fluorosurfactant)
Metal oxide fine particle dispersion T: 137.2 parts by mass (49 mass% aqueous solution of the titanium oxide dispersion)
Preservative C: 0.9 parts by mass (the above compound, 3.5% by mass methanol solution)
・ Distilled water ... 75.8 parts by mass

[Example 7]
A polymer sheet for a solar cell module of Example 7 was obtained in the same manner as in Example 1 except that the coloring layer coating solution was changed as follows.
-Preparation of coating solution for forming colored layer-
Each component in the following composition was mixed to prepare a coating solution for forming a colored layer.
(Composition of coating solution for forming colored layer in Example 7)
-Carbon black aqueous dispersion: 71.4 parts by mass (manufactured by Dainichi Seika Co., Ltd. MF-5630 black, solid content: 31.5%)
・ Polyolefin binder (Binder A): 563.1 parts by mass (manufactured by Unitika Ltd., Arrow Base SE1013N, solid content: 20% by mass)
・ Oxazoline compound (crosslinking agent) 107.7 parts by mass (Epocross WS700 manufactured by Nippon Shokubai Co., Ltd. 25% aqueous dispersion)
Surfactant a: 18.0 parts by mass (manufactured by Sanyo Chemical Industries, NAROACTY CL-95, 5% aqueous solution)
Surfactant b: 9.0 parts by mass (1% aqueous solution of the fluorosurfactant)
Metal oxide fine particle dispersion T 68.6 parts by mass (49% by mass aqueous solution of the titanium oxide dispersion)
Metal oxide fine particle dispersion K 54.6 parts by mass (CI Pigmet Black 26, iron, manganese, copper composite oxide, manufactured by Dainichi Seika Kogyo Co., Ltd., MF-5533 Black, solid content 61 .5%)
Preservative C: 0.9 parts by mass (the above compound, 3.5% by mass methanol solution)
・ Distilled water ... 106.7 parts by mass

[Example 8]
A polymer sheet for a solar cell module of Example 8 was obtained in the same manner as in Example 1 except that the coloring layer coating solution was changed as follows.
-Preparation of coating solution for forming colored layer-
Each component in the following composition was mixed to prepare a coating solution for forming a colored layer.
(Composition of the coating solution for forming the colored layer in Example 8)
-Carbon black aqueous dispersion: 72.2 parts by mass (manufactured by Dainichi Seika Co., Ltd. MF-5630 black, solid content: 31.5%)
Polyolefin binder (Binder A) 321.8 parts by mass (produced by Unitika Ltd., Arrow Base SE1013N, solid content 20% by mass)
Oxazoline compound (crosslinking agent) 61.6 parts by mass (Epocross WS700, 25% solids aqueous dispersion manufactured by Nippon Shokubai Co., Ltd.)
Surfactant a: 13.0 parts by mass (manufactured by Sanyo Chemical Industries, NAROACTY CL-95, 5% aqueous solution)
Surfactant b: 16.3 parts by mass (1% aqueous solution of the fluorosurfactant)
・ Sliding agent: 156.0 parts by mass (manufactured by Chukyo Yushi Co., Ltd., Cerazole 524, 3% aqueous dispersion)
Metal oxide fine particles S: 159.8 parts by mass (manufactured by Nissan Chemical Co., Ltd., Snowtex ZL, 40% by mass)
Metal oxide fine particle dispersion K 54.6 parts by mass (CI Pigmet Black 26, iron, manganese, copper composite oxide, manufactured by Dainichi Seika Kogyo Co., Ltd., MF-5533 Black, solid content 61 .5%)
Preservative C: 0.7 parts by mass (the compound, a 3.5% by mass methanol solution)
・ Distilled water ... 114.7 parts by mass

[Comparative Example 1]
A polymer sheet for a solar cell module of Comparative Example 1 was obtained in exactly the same manner as in Example 1 except that the color layer coating solution was changed to the following.
-Preparation of coating solution for forming colored layer-
Each component in the following composition was mixed to prepare a coating solution for forming a colored layer.
(Composition of the coating solution for forming the colored layer in Comparative Example 1)
-Carbon black aqueous dispersion: 71.4 parts by mass (manufactured by Dainichi Seika Co., Ltd. MF-5630 black, solid content: 31.5%)
・ Polyolefin binder (Binder A): 501.0 parts by mass (produced by Unitika Ltd., Arrow Base SE1013N, solid content: 20% by mass)
Oxazoline compound (crosslinking agent) 101.2 parts by mass (Epocross WS700, 25% solids aqueous dispersion manufactured by Nippon Shokubai Co., Ltd.)
Surfactant a: 18.0 parts by mass (manufactured by Sanyo Chemical Industries, NAROACTY CL-95, 5% aqueous solution)
Surfactant b: 9.0 parts by mass (1% aqueous solution of the fluorosurfactant)
Preservative C: 0.9 parts by mass (the above compound, 3.5% by mass methanol solution)
・ Distilled water ... 298.5 parts by mass

[Comparative Example 2]
A polymer sheet for a solar cell module of Comparative Example 2 was obtained in exactly the same manner as in Example 1 except that the color layer coating solution was changed to the following.
-Preparation of coating solution for forming colored layer-
Each component in the following composition was mixed to prepare a coating solution for forming a colored layer.
(Composition of the coating solution for forming a colored layer in Comparative Example 2)
-Carbon black aqueous dispersion: 71.4 parts by mass (manufactured by Dainichi Seika Co., Ltd. MF-5630 black, solid content: 31.5%)
Polyolefin binder (Binder A): 717.8 parts by mass (produced by Unitika Ltd., Arrow Base SE1013N, solid content 20% by mass)
・ Oxazoline compound (crosslinking agent) 145.0 parts by mass (Epocross WS700 manufactured by Nippon Shokubai Co., Ltd., 25% solid dispersion)
Surfactant a: 18.0 parts by mass (manufactured by Sanyo Chemical Industries, NAROACTY CL-95, 5% aqueous solution)
Surfactant b: 9.0 parts by mass (1% aqueous solution of the fluorosurfactant)
Preservative C: 0.9 parts by mass (the above compound, 3.5% by mass methanol solution)
・ Distilled water: 37.8 parts by mass

<Evaluation>
(1) Surface resistivity measurement The digital electrometer R8252 (Co., Ltd.) was used as a measuring device for the colored layer surface of the polymer sheet for solar cell module of each Example and Comparative Example in an atmosphere of 23 ° C. and relative humidity 65%. The surface resistivity was measured in accordance with JIS K 6911 using a product obtained by connecting Resistivity Chamber R12704A (manufactured by Advantest) to Advantest. The unit is Ω / □ (= Ω / sq).
The obtained results are shown in Table 1 below. The number following “E +” in the column of surface resistivity is the index part. For example, “3E + 13” indicates “3 × 10 ¹³ ”.

(2) Scratch resistance The polymer sheet for solar cell module of each Example and Comparative Example was conditioned for 24 hours in an atmosphere of 23 ° C. and 65% relative humidity, and the scratch strength was measured by the following method. did. First, the surface of the colored layer of the sample was scratched under the condition of a speed of 1 cm / second while changing the weight from 0 to 100 g with a 0.5 mmR sapphire needle. At this time, the presence or absence of scratches on the surface was examined, and the load at which scratches were first observed by visual observation was set as the minimum load, and this value was used as an index of scratch strength. The scratch resistance was evaluated according to the following 5 levels.
5: Scratches at 50 g or more 4: Scratches at 25 g or more and less than 50 g 3: Scratches at 18 g or more and less than 24 g (allowable quality minimum level)
2: Scratches at 11 g or more and less than 17 g (unacceptable quality)
1: Scratches less than 11 g The results obtained are listed in Table 1 below.

(3) Transparent OD of the entire sheet
The transmission OD of the polymer sheet for solar cell module of each Example and Comparative Example was measured using a Macbeth densitometer (manufactured by Macbeth).
The obtained results are shown in Table 1 as the transmission OD of the entire sheet.

From Table 1 above, it was found that the polymer sheet for a solar cell module of the present invention has a sufficient black density, has excellent design properties, and has excellent insulating properties, despite its low production cost.
On the other hand, it was found from Comparative Examples 1 and 2 that when the metal oxide fine particles were not included, the surface resistivity was low and there was a problem in insulation.

[Examples 101 to 108]
About the polymer sheet for solar cell modules of Examples 1-8, the back sheet for solar cell modules was created with the following method.
The polymer sheets for solar cell modules of Examples 1 to 8, the aluminum sheet having a thickness of about 20 μm, and the weather-resistant polyethylene terephthalate sheet having a thickness of 100 μm were bonded together in this order with the following adhesive. For the bonding, an adhesive was first applied to a weather-resistant polyethylene terephthalate sheet having a thickness of 100 μm, dried at 100 ° C. for 1 minute, and then bonded to an aluminum sheet. Next, an adhesive was applied to the opposite surface of the aluminum sheet on which the weather-resistant polyethylene terephthalate sheet was bonded, dried at 100 ° C. for 1 minute, and then the polymer sheet for solar cell module of each example was bonded. In addition, the polymer sheet for solar cell modules and aluminum sheet of each Example were bonded together in the form in which the easily bonding layer of the polymer sheet for solar cell modules of each Example and an aluminum sheet faced each other. The thickness of the adhesive was about 5 μm. The bonded sample was heat-treated at 40 ° C. for 4 days, and further conditioned for 24 hours in an atmosphere of 25 ° C. and a relative humidity of 60%.
(adhesive)
Takelac A-1143 (manufactured by Mitsui Chemicals, Inc., adhesive) ... 9 parts by mass Takenate A-50 (manufactured by Mitsui Chemicals, Inc., curing agent) ... 1 part by mass Butyl acetate ... 10 parts by mass

Using the obtained back sheet for a solar cell module, a solar cell module was created by the following method.
3 mm thick tempered glass, EVA sheet (SC50B manufactured by Mitsui Chemicals Fabro Co., Ltd.), crystalline solar cell, EVA sheet (SC50B manufactured by Mitsui Chemicals Fabro Co., Ltd.), and solar of each example The polymer sheets for the battery module were superposed in this order, and hot-pressed using a vacuum laminator (Nisshinbo Co., Ltd., vacuum laminating machine) to adhere to EVA. At this time, it arrange | positioned so that the colored layer of the polymer sheet for solar cell modules of each Example may contact with an EVA sheet | seat. Moreover, the adhesion method is as follows.
<Adhesion method>
Using a vacuum laminator, evacuation was performed at 128 ° C. for 3 minutes, and then pressure was applied for 2 minutes to temporarily bond. Thereafter, the main adhesion treatment was performed in a dry oven at 150 ° C. for 30 minutes.
When the power generation operation was performed on the produced solar cell modules of Examples 101 to 108, all showed good power generation performance as a solar cell.

DESCRIPTION OF SYMBOLS 10 Solar cell module 11 Easy-adhesion layer 12 Undercoat layer 16 Colored layer 17 Overcoat layer 18 Polyester support body 19 Colored surface 20 of support body Solar cell module polymer sheet 22 Solar cell element 24 Sealant 26 Transparent substrate 27 Aluminum Sheet 28 Weather-resistant polyethylene terephthalate sheet 29 Adhesive 30 Back sheet for solar cell module

Claims (12)

A polyester support;
Having a colored layer disposed on at least one side of the polyester support;
The colored layer contains a binder made of an organic polymer, carbon black, and metal oxide fine particles,
The said colored layer satisfy | fills following formula (1), The polymer sheet for solar cell modules characterized by the above-mentioned.
Formula (1)
1 ≦ W2 / W1 ≦ 10
(In Formula (1), W1 represents the content (unit: mass%) of carbon black in the colored layer, and W2 represents the content (unit: mass%) of metal oxide fine particles in the colored layer.)   The polymer sheet for a solar cell module according to claim 1, wherein the metal oxide fine particles include at least one of white metal oxide fine particles and black metal oxide fine particles.   The polymer sheet for a solar cell module according to claim 1, wherein the metal oxide fine particles contain at least one metal selected from titanium, cobalt, chromium, iron, manganese, copper, and silicon.   4. The solar cell module according to claim 1, wherein the metal oxide fine particles include at least one selected from titanium oxide, black composite metal oxide, and silicon dioxide. Polymer sheet.   The polymer sheet for a solar cell module according to claim 4, wherein the black composite metal oxide contains two or more of cobalt, chromium, iron, manganese and copper.   The polymer sheet for a solar cell module according to claim 4 or 5, wherein the black complex metal oxide contains at least one selected from PBk26, PBk27, and PBk28.   The sun according to claim 1, wherein the metal oxide fine particles include at least one white metal oxide fine particles and at least one black composite metal oxide. Polymer sheet for battery modules.   The sun according to any one of claims 1 to 7, wherein the binder made of the organic polymer contains at least one selected from polyolefin resins and resins containing a styrene-butadiene copolymer component as a main component. Polymer sheet for battery modules.   The polymer sheet for a solar cell module according to any one of claims 1 to 8, wherein the colored layer has a thickness of 0.3 to 6 µm.   The polymer sheet for a solar cell module according to any one of claims 1 to 9, wherein a content W1 of carbon black in the colored layer is 5 to 18% by mass.   A back sheet for a solar cell module comprising the polymer sheet according to any one of claims 1 to 10.   A solar cell module comprising the back sheet for a solar cell module according to claim 11.

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