TWI566927B - Polymer sheet for solar cell module and method for producing the same, backsheet for solar cell module, and solar cell module - Google Patents

Description

Polymer sheet for solar battery module and manufacturing method thereof, back sheet for solar battery module and solar battery module

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

The solar cell is a power generation method that does not emit carbon dioxide during power generation and has a small environmental load, and has recently been rapidly popularized. The solar cell module generally has a structure in which a front substrate disposed on the surface side on which sunlight is incident and a protective sheet for a solar cell disposed on the side opposite to the surface side on which sunlight is incident (back side) (so-called back) Between the plates), a structure of a solar cell unit in which a solar cell element is sealed with a sealing material is sandwiched, and ethylene is respectively used between the front substrate and the solar cell unit and between the solar cell unit and the back plate. - Ethylene-Vinyl Acetate (EVA) resin or the like is sealed.

Since the backing plate has a function of preventing moisture from infiltrating from the back surface of the solar cell module, glass or the like has been used in the past, but in recent years, there has been a tendency to apply a polymer sheet such as a polyester sheet from the viewpoint of cost and the like. Further, the back sheet is required not only to have a function of suppressing the permeation of water but also to have durability (weather resistance, etc.), and the like, for example, a functional layer such as a layer for improving weather resistance on a polymer support is laminated on a polymer support. Constructed in body. As a method of producing such a laminated back sheet, a method of laminating by coating is known from the viewpoint of cost, etc., but in order to prevent peeling of the functional coating layer, it is required to increase the coating layer and the polymer. The adhesion between the supports. Further, as a solvent used in the coating liquid of such a functional coating layer, previously Organic solvents have been used from the viewpoint of easiness of film formation, drying property, and the like.

As a back sheet for a solar cell which is excellent in adhesion between a functional coating layer having weather resistance and a water-impermeable sheet, the following solar cell back sheet has been proposed: the solar cell back sheet is a Si-evaporated polymer. A cured coating film is formed on one surface of the water-impermeable sheet such as a material sheet, and the cured coating film contains a fluorine-based polymer containing a curable functional group (see Patent Document 1). Further, Patent Document 1 discloses that a solvent-based coating composition is preferable in terms of easiness of film formation, curability, and good drying property, and is prepared in Examples 1 to 3 of the document. A coating containing a fluorine-based polymer using butyl acetate as a solvent.

Prior technical literature

Patent Document: Japanese Patent Laid-Open No. 2007-35694

In recent years, from the viewpoint of being installed in an environment with higher power generation efficiency, it is required to install the solar battery module in a severe humid heat environment outside, and to require stable operation for a long period of time in a humid heat environment.

In view of such a situation, the inventors of the present invention have also studied the performance of the solar cell backsheet described in Patent Document 1 after the moist heat, and as a result, it has been found that the fluoropolymer coating layer after the wet heat has passed through the time. Further improvement with the adhesion of the polymer support is expected.

The present invention has been developed in order to solve the above problems. That is, the object of the present invention is to provide a polymer sheet for a solar cell module and a method for producing the same, wherein the polymer sheet for a solar cell module has an organic solvent The fluoropolymer layer formed by the coating liquid of the agent system has good adhesion to the fluoropolymer layer after the heat and humidity.

The present inventors have conducted intensive studies to solve the above problems, and as a result, it has been found that a fluorenone is newly provided between a fluoropolymer layer formed using a coating liquid of an organic solvent system and a polymer support. The above problem can be solved by changing the layer structure by the polymer layer of the polymer.

The present invention as a specific method for solving the above problems is as follows.

[1] A polymer sheet for a solar cell module, comprising: a polymer support; an anthranone-based polymer layer disposed on at least one side of the polymer support and containing an anthrone a polymer as a binder; and a fluorine-containing polymer layer which is disposed on the fluorenone-containing polymer layer and contains a fluorine-based polymer as a binder, and the fluorine-containing polymer layer is fluorine-containing More than 0.01% by mass or more of the organic solvent is contained in all the binders in the polymer layer.

[2] The polymer sheet for a solar cell module according to [1], wherein the fluorine-containing polymer layer is preferably formed by coating a coating liquid using an organic solvent as a coating solvent. The coated film was dried.

[3] The polymer sheet for a solar cell module according to [1] or [2], wherein the polymer support is preferably a polyester support.

[4] The polymer sheet for a solar cell module according to any one of [1] to [3], wherein at least one of the fluorenone-containing polymer layer and the fluorine-containing polymer layer is preferable. Contains UV absorbers.

[5] The polymer sheet for a solar cell module according to any one of [1] to [4], preferably the fluorenone-containing polymer layer and the fluorine-containing polymer. At least one of the layers contains 3 to 30% by mass of a component derived from a crosslinking agent with respect to all the binders in the respective polymer layers.

[6] The polymer sheet for a solar cell module according to any one of [1] to [5], wherein the component derived from the crosslinking agent containing the fluorenone-based polymer layer is preferably selected from the group consisting of a component derived from at least one of a thioxazoline crosslinking agent and a carbodiimide crosslinking agent, and a component derived from the crosslinking agent of the fluorine-containing polymer layer is derived from an isocyanate group The ingredients of the joint agent.

[7] The polymer sheet according to any one of [1] to [6] wherein the polymer support contains inorganic fine particles.

[8] The polymer sheet according to [7], wherein the polymer support has a feature comprising two or more layers having different contents of the inorganic fine particles.

[9] The polymer sheet according to any one of [1] to [8] wherein the polymer support is characterized by being a polyester support containing a blocking agent.

[10] The polymer sheet according to [9], wherein the above-mentioned blocking agent has the following characteristics: a carbodiimide-based blocking agent.

[11] A method for producing a polymer sheet for a solar cell module, comprising the steps of: coating an anthrone-containing polymer containing an anthrone-based polymer as a binder on at least one side of a polymer support; a coating liquid for forming a layer, and drying the coating film to form an oxime-containing polymer layer; and applying a fluorine-containing polymer as a binder to the fluorenone-containing polymer layer and containing an organic solvent Coating solvent-containing fluorine-containing polymer layer shape A coating liquid was used, and the coating film was dried.

[12] The method for producing a polymer sheet for a solar cell module according to the above [11], wherein the coating liquid for forming an anthrone-containing polymer layer contains water as a coating solvent.

[13] The method for producing a polymer sheet for a solar cell module according to [11] or [12], wherein the polymer support is preferably a polyester support.

[14] The method for producing a polymer sheet for a solar cell module according to any one of [11] to [13], preferably, the coating liquid for forming an anthrone-containing polymer layer and the above-mentioned An ultraviolet absorber is added to at least one of the coating liquid for forming a fluorine-based polymer layer.

[15] The method for producing a polymer sheet for a solar cell module according to any one of [11] to [14], wherein the coating liquid for forming an anthrone-containing polymer layer and the above-mentioned In at least one of the coating liquids for forming a fluorine-based polymer layer, a crosslinking agent is added in an amount of 3 to 30% by mass based on all the binders in the coating liquid for forming each polymer layer.

[16] The method for producing a polymer sheet for a solar cell module according to any one of [11] to [15], which is preferably added to the coating liquid for forming an anthrone-containing polymer layer. At least one crosslinking agent selected from the group consisting of an oxazoline crosslinking agent and a carbodiimide crosslinking agent, and an isocyanate crosslinking agent is added to the coating liquid for forming a fluorine-containing polymer layer.

[17] A polymer sheet for a solar cell module, which is produced by the method for producing a polymer sheet for a solar cell module according to any one of [11] to [16].

[18] A back sheet for a solar cell module, characterized by having as [1] The polymer sheet according to any one of [10] and [17].

[19] A solar battery module comprising the back sheet according to [18].

According to the present invention, there is provided a polymer sheet for a solar cell module having a fluoropolymer layer formed by using an organic solvent-based coating liquid, and a method for producing the same, wherein the wet heat is formed The adhesion of the fluoropolymer layer after the time was good. Further, according to the present invention, it is possible to provide a solar battery module in which the polymer sheet for a solar battery module is disposed as a back sheet for a solar battery module.

Hereinafter, the polymer sheet for a solar cell module of the present invention, a method for producing the same, a back sheet for a solar cell module, and a solar cell module will be described in detail.

The description of the constituent elements described below may be performed according to a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. In the present specification, the numerical range expressed by "~" means a range including the numerical values described before and after "~" as the lower limit and the upper limit.

[Polymer sheet for solar cell module]

The polymer sheet for a solar cell module of the present invention (hereinafter also referred to as a polymer sheet of the present invention) is characterized in that it has a polymer support and is disposed on at least one side of the polymer support and contains an anthrone-based polymerization. a fluorenone-containing polymer layer as a binder, a fluorine-containing polymer layer disposed on the fluorenone-containing polymer layer and containing a fluorine-based polymer as a binder, and the fluorine-containing polymer layer 0.01% by mass or more of the organic solvent is contained with respect to all the binders in the fluorine-containing polymer layer.

Previously, from the viewpoint of improving the adhesion of the fluoropolymer layer to the polymer support or other functional layers, the surface of the polymer support was subjected to surface treatment, and then the fluoropolymer layer was applied or fluorine-containing. A crosslinking agent is added to the coating liquid for forming a polymer layer. However, it is known that the adhesion of the fluoropolymer layer to the polymer support or other functional layer deteriorates in the case of the previous method after the moist heat has passed.

On the other hand, in the present invention, the fluorenone-containing polymer layer is formed between the fluoropolymer layer and the polymer support, whereby the coating liquid using the organic solvent can be improved after the moist heat is passed. The adhesion of the formed fluoropolymer layer.

First, a preferred configuration of the polymer sheet of the present invention is shown in Figs. 1 and 2 .

The polymer sheet for a solar cell module shown in FIG. 1 is provided with an adjacent fluorenone-containing polymer layer 3 on one surface side of the polymer support 16, and further has a fluorine-containing polymer layer 4 disposed thereon. And form the outermost layer.

The polymer sheet shown in Fig. 2 is provided on the surface side of the polymer support 16 opposite to the surface on which the fluorenone-based polymer layer 3 and the fluorinated polymer layer 4 are provided, and the undercoat layer 2 is provided. And the color layer 1.

Hereinafter, the details of the preferred aspects of each layer will be described for the polymer sheet of the present invention.

<Polymer support>

Examples of the polymer support include a polyolefin such as polyester, polypropylene or polyethylene, or a support such as a fluorine-based polymer such as polyvinylidene fluoride. The support may be in the form of a film or a sheet. In terms of cost or mechanical strength, etc. A polyester support is preferred.

The polyester support used as the polymer support (support) in the present invention is a linear saturated poly synthesized from an aromatic dibasic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof. ester. Specific examples of the polyester include polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate, and poly(1,4-cyclohexyl dimethylene pair). A film or sheet of phthalic acid ester or polyethylene-2,6-naphthalenedicarboxylate. Among them, polyethylene terephthalate or polyethylene-2,6-naphthalenedicarboxylate is particularly preferred in terms of balance of mechanical properties or cost.

The above polyester support may be a homopolymer or a copolymer. Further, a small amount of other types of resins such as polyimine or the like may be blended in the above polyester.

In the case of polymerizing the polyester of the present invention, it is preferable to use a Sb-based, Ge-based or Ti-based compound as a catalyst from the viewpoint of suppressing the carboxyl group content to be within a predetermined range, and particularly preferably a Ti-based compound. In the case of using a Ti-based compound, it is preferred to polymerize the Ti-based compound in such a manner that the Ti element conversion value is 1 ppm or more and 30 ppm or less, preferably 3 ppm or more and 15 ppm or less. Used as a catalyst. When the amount of the Ti-based compound used is in the above range in terms of Ti element, the terminal carboxyl group can be adjusted to the following range, and the hydrolysis resistance of the polymer support can be kept low.

For the synthesis of a polyester using a Ti-based compound, for example, Japanese Patent Publication No. Hei 8-301198, Japanese Patent No. 2,546,624, Japanese Patent No. 3,335, 683, Japanese Patent No. 3,718,380, and Japanese Patent No. Japanese Patent No. 3,897, 756, Japanese Patent No. 3962226, Japanese Patent No. 3979866, Japanese Patent No. 3996871, Japanese Patent No. 4000867, Japanese Patent No. 4,053,837, Japanese Patent No. 4,127,119, Japanese Patent No. 4,147,710, Japanese Patent No. 4,159,154 The method described in Japanese Patent No. 4269704, Japanese Patent No. 4313538, and the like.

The carboxyl group content in the polyester support is preferably 55 equivalent/t (eq/t, equivalent/ton, the same or less) or less, more preferably 35 equivalent/t or less, further preferably 20 equivalent/t or less, further preferably It is 13 equivalent/t or less. The lower limit of the carboxyl group content is desirably 2 equivalent/t in terms of maintaining the adhesion to the layer formed on the polyester film (for example, the coloring layer). When the carboxyl group content is 55 equivalent/t or less, the hydrolysis resistance can be maintained, and the decrease in strength at the time of moist heat and time can be suppressed to be small.

The carboxyl group content in the polyester can be adjusted by the type of the polymerization catalyst, the film formation conditions (film formation temperature or time).

The carboxyl group content (AV) is such that the target polyester support is completely dissolved in a mixed solution of benzyl alcohol/chloroform (=2/3; volume ratio), and phenol red is used as an indicator, and a reference liquid (0.025 N) is used. The KOH-methanol mixed solution was titrated and the value calculated based on the titer.

The polyester support in the present invention is preferably obtained by solid phase polymerization after polymerization. Thereby, a preferred carboxyl group content can be achieved. The solid phase polymerization may be a continuous method (a method in which a tower is filled with a resin, and heated while being slowly stagnation for a predetermined period of time), or may be a batch method (in a container) A method of putting in resin and heating for a predetermined time). Specifically, Japanese Patent No. 2621563 and Japanese Patent No. The method described in Japanese Patent No. 3, 136, 876, Japanese Patent No. 3, 136, 774, Japanese Patent No. 3, 036, 585, Japanese Patent No. 3,166, 522, Japanese Patent No. 3,617, 340, Japanese Patent No. 3,680, 523, Japanese Patent No. 3717392, Japanese Patent No. 4167159, and the like.

The temperature of the solid phase polymerization is preferably 170 ° C or more and 240 ° C or less, more preferably 180 ° C or more and 230 ° C or less, and still more preferably 190 ° C or more and 220 ° C or less. Further, the solid phase polymerization time is preferably 5 hours or longer and 100 hours or shorter, more preferably 10 hours or longer and 75 hours or shorter, and still more preferably 15 hours or longer and 50 hours or shorter. The solid phase polymerization is preferably carried out in a vacuum or under a nitrogen atmosphere.

The polyester support in the present invention is preferably, for example, a biaxially stretched film which is formed by melt-extruding the above-mentioned polyester in a film form and then solidified by a casting drum. The stretched film is stretched once or twice at a total magnification of 3 to 6 times in the longitudinal direction at Tg~(Tg+60) °C, and thereafter at Tg~(Tg+60) ) ° C is extended in the width direction by a factor of 3 to 5 times.

Further, heat treatment may be performed at 180 ° C to 230 ° C for 1 to 60 seconds as needed.

In the case where the above polymer support used in the present invention is a polyester support, it is preferred to add a terminal blocking agent, that is, the above polymer support is a polyester support containing a terminal blocking agent. The blocking agent described in the present invention is a compound which reacts with a terminal carboxylic acid of a polyester support, and has a function of improving hydrolysis resistance of the polyester support. It is considered that the hydrolysis of the polyester support is accelerated by the catalytic effect of H ⁺ generated by the terminal carboxylic acid or the like, so that hydrolysis resistance is improved by suppressing the formation of H ⁺ by the blocking agent.

Specific examples of the terminal blocking agent include an epoxy compound, a carbodiimide compound, an oxazoline compound, a carbonate compound, etc., and a carbon bismuth having high affinity with PET and high blocking ability is preferred. Imine.

In the case of the carbodiimide compound, those having a cyclic structure are preferred (for example, those described in JP-A-2011-153209). The reason is that the terminal carboxylic acid of the polyester undergoes a ring-opening reaction with the cyclic carbodiimide, one end reacts with the polyester, and the other end of the ring-opening reacts with other polyesters to be polymerized, thereby inhibiting the isocyanate. The generation of gas.

Specific examples of the carbodiimide compound are dicyclohexylcarbodiimide, diisopropylcarbodiimide, dimethylcarbodiimide, 1,5-naphthylcarbodiimide, 4 , 4'-diphenylmethane carbodiimide, 4,4'-diphenyldimethylmethane carbodiimide, a cyclic structure of carbon dioxide described in JP-A-2011-153209 Amines, etc.

The molecular weight of the blocking agent is preferably from 200 to 100,000, more preferably from 2,000 to 80,000, and further preferably from 10,000 to 50,000. When the molecular weight of the terminal blocking agent is 100,000 or more, it is not easy to uniformly disperse in the polyester, and it is difficult to sufficiently exhibit the weather resistance improving effect. On the other hand, when it is less than 200, it is easy to volatilize during extrusion and film formation, and it is difficult to exhibit the effect of improving weather resistance, which is not preferable.

The amount of the blocking agent to be added is preferably from 0.1% by mass to 10% by mass, more preferably from 0.2% by mass to 5% by mass, even more preferably from 0.3% by mass to 2% by mass based on the polyester. When the amount added is less than 0.1% by mass, a sufficient weather resistance improving effect may not be obtained, and if it exceeds 10% by mass, sometimes Aggregates are produced in the manufacturing steps of the polyester support.

Microparticles may also be added to the polymer support to increase reflectivity.

Suitable inorganic particles can be used, for example, wet and dry cerium oxide, colloidal cerium oxide, calcium carbonate, aluminum silicate, calcium phosphate, aluminum oxide, magnesium carbonate, zinc carbonate, titanium oxide, zinc oxide (zinc hua ), cerium oxide, cerium oxide, zirconium oxide, tin oxide, antimony oxide, magnesium oxide, barium carbonate, zinc carbonate, basic lead carbonate (lead white), barium sulfate, calcium sulfate, lead sulfate, zinc sulfide, mica, mica Titanium, talc, clay, kaolin, lithium fluoride, calcium fluoride, etc., among these fine particles, titanium dioxide, barium sulfate, and particularly preferably titanium dioxide. Further, the titanium oxide may be either an anatase or rutile type, and is preferably a rutile type having a low photocatalytic activity. The titanium dioxide may be subjected to an inorganic treatment such as alumina or cerium oxide or an organic treatment such as an oxime ketone or an alcohol system, as needed.

A well-known method can be used for the addition of the fine particles in the polymer support. As a typical method, for example, when the polymer support is a polyethylene terephthalate support, the following method can be mentioned. (A) A method of adding fine particles before the end of the transesterification reaction or the esterification reaction in the synthesis of polyethylene terephthalate or adding microparticles before the start of the polycondensation reaction. (B) A method of adding fine particles to polyethylene terephthalate and performing melt kneading. (C) Producing a large amount of parent particles (also referred to as master batch (MB)) added with fine particles in the above methods (A) and (B), and the like and polyphenylene containing no fine particles A method in which ethylene formate is kneaded and contains a predetermined amount of fine particles. (D) A method of directly using the mother particles of the above (C).

Among these, a master batch method in which a polyester resin and fine particles are mixed by an extruder in advance (MB method: (C) above) is preferred. Alternatively, the following method may be employed: a polyester resin and fine particles which have not been dried before are put into an extruder, and MB is removed while removing moisture or air. Further, it is preferable to use a polyester resin which has been slightly dried beforehand to produce MB, and in this case, an increase in the acid value of the polyester can be suppressed. In this case, a method of extruding while degassing or a method of extruding without degassing by a sufficiently dried polyester resin may be mentioned.

In the case of adding fine particles, the average particle diameter of the fine particles is preferably from 0.05 μm to 5 μm, more preferably from 0.1 μm to 3 μm, still more preferably from 0.15 μm to 0.8 μm. If it is less than 0.05 μm, the reflectance cannot be sufficiently increased, and if it exceeds 5 μm, the mechanical strength is remarkably lowered and it is not preferable.

The content of the fine particles is from 2% by mass to 50% by mass, preferably from 5% by mass to 20% by mass based on the total mass of the polymer support. When it is less than 2% by mass, the reflectance cannot be sufficiently increased, and if it exceeds 50% by mass, the mechanical strength is remarkably lowered and it is not preferable.

The polymer support used in the present invention may have a content of fine particles in a thickness direction, and may include two or more layers having different fine particle contents. In the latter case, from the viewpoint of durability, a three-layered structure having a layer having a high content of fine particles in a polymer support and a layer having a low particle content on the front and back sides is preferable. It is preferred that the layer having a low inorganic fine particle content does not contain inorganic fine particles.

The thickness of the polymer support (particularly the polyester support) is preferably from about 25 μm to about 300 μm. If the thickness is 25 μm or more, the mechanical strength is good. If it is 300 μm or less, it is advantageous in terms of cost.

In particular, when the thickness of the polyester support is 120 μm or more and 300 μm or less and the carboxyl group content in the polyester is 2 equivalent/t to 20 equivalent/t, the effect of improving the wet heat durability is further exhibited.

The polymer support is preferably subjected to surface treatment by corona treatment, flame treatment, low pressure plasma treatment, atmospheric piezoelectric slurry treatment or ultraviolet treatment. By performing these surface treatments, the adhesion of the situation exposed to a hot and humid environment can be further improved. Among them, in particular, by performing corona treatment, a more excellent adhesion improving effect can be obtained.

These surface treatments improve the adhesion by adding a carboxyl group or a hydroxyl group to the surface of a polymer support (for example, a polyester support), and use a crosslinking agent (particularly an oxazoline system having high reactivity with a carboxyl group or In the case of a carbodiimide-based crosslinking agent, a more strong adhesion can be obtained. This situation is more pronounced in the case of corona treatment. Therefore, it is particularly preferred that the surface of the side of the polymer support forming the polymer layer is subjected to corona treatment.

<Anthrone-containing polymer layer>

The polymer sheet of the present invention has an fluorenone-containing polymer layer which is disposed on one surface of the above polymer support and contains an anthrone-based polymer as a binder.

In the polymer sheet of the present invention, by providing the above-described fluorenone-containing polymer layer, the adhesion to the above-mentioned fluorine-containing polymer layer after moist heat aging can be improved. It is preferred that the adhesion between adjacent materials such as a polymer support is also improved. The above fluorenone-containing polymer layer in the present invention is preferably a form directly formed on a polymer support.

The fluorenone-containing polymer layer may be further composed of other components, which may be different depending on the application to be used, depending on the case. The fluorenone-containing polymer layer may have a configuration that also serves as a colored layer, and the colored layer exhibits a function of reflecting sunlight or imparting design properties.

When the fluorenone-containing polymer layer is configured as a light-reflecting layer that reflects sunlight on the incident side, for example, a colorant such as a white pigment may be further used in the polymer layer in addition to the fluorenone-based polymer component. And constitute.

Hereinafter, each component constituting the above fluorenone-containing polymer layer will be described in detail.

-Anthrone-based polymer -

The fluorenone-containing polymer layer in the present invention contains an fluorenone polymer. The above-mentioned anthrone-based polymer means a polymer containing at least one structure having a (poly)oxyl structure in a molecular chain. When the fluorenone-based polymer is contained, the adjacent material such as the polymer support or the fluoropolymer layer described later is excellent in adhesion after wet heat.

The anthrone-based polymer in the present invention is not particularly limited as long as it has a (poly)oxyl structure in the molecular chain, and is preferably a homopolymer of a compound having a (poly)oxyalkylene structural unit (monomerization). a copolymer of a compound having a (poly)oxyalkylene structural unit and another compound, that is, a copolymerized polymer having a (poly)oxyl structural unit and other structural units. The other compound is a non-oxyalkylene-based monomer or polymer, and the other structural unit is a non-oxyalkylene-based structural unit.

The anthrone-based polymer in the present invention preferably has a (poly)oxyl structural unit represented by the following formula (1) as a (poly)oxyl structure.

In the above formula (1), R ¹ and R ² each independently represent a hydrogen atom, a halogen atom or a monovalent organic group. Here, R ¹ and R ² may be the same or different, and a plurality of R ¹ and R ² may be the same or different from each other. n represents an integer of 1 or more.

a portion of "-(Si(R ¹ )(R ² )-O) _n -" as a (poly)oxyalkylene segment in the above anthrone-based polymer (expressed by the formula (1) In the (poly)oxyl structural unit), R ¹ and R ² may be the same or different and each represents a hydrogen atom, a halogen atom or a monovalent organic group.

"-(Si(R ¹ )(R ² )-O) _n -" is a (poly)oxyalkylene segment derived from various (poly) alkoxynes having a linear, branched or cyclic structure.

Examples of the halogen atom represented by R ¹ and R ² include a fluorine atom, a chlorine atom, and an iodine atom.

The "monovalent organic group" represented by R ¹ and R ² is a group capable of forming a covalent bond with an Si atom, and may have a substituent without being substituted. Examples of the monovalent organic group include an alkyl group (e.g., a methyl group, an ethyl group, etc.), an aryl group (e.g., a phenyl group, etc.), an aralkyl group (e.g., a benzyl group, a phenylethyl group, etc.), an alkoxy group (e.g. A methoxy group, an ethoxy group, a propoxy group, etc.), an aryloxy group (for example, a phenoxy group), a mercapto group, an amine group (for example, an amine group, a diethylamino group, etc.), a guanylamino group, etc.

In particular, R ¹ and R ² are each independently a hydrogen atom or a chlorine atom, in terms of adhesion to an adjacent material such as a polymer support or a fluorine-containing polymer layer and durability in a hot and humid environment. a bromine atom, an unsubstituted or substituted alkyl group having 1 to 4 carbon atoms (particularly methyl, ethyl), an unsubstituted or substituted phenyl group, an unsubstituted or substituted alkoxy group, The mercapto group, the unsubstituted amino group, and the mercaptoamine group are more preferably an unsubstituted or substituted alkoxy group (preferably a carbon number of 1 to 4) in terms of durability in a hot and humid environment. Oxy).

The above n is preferably from 1 to 5,000, more preferably from 1 to 1,000.

a portion of "-(Si(R ¹ )(R ² )-O) _n -" in the above anthrone-based polymer with respect to the total mass of the above-described anthrone-based polymer (expressed by the formula (1) ( The ratio of the polyoxymethane structural unit is preferably 15% by mass to 99% by mass, more preferably 25% by mass to 85% by mass, particularly preferably 25% by mass to 50% by mass, and particularly preferably 25% by mass. ~35 mass%. When the ratio of the (poly)oxyl structural unit is 15% by mass or more, the film strength on the surface of the polymer layer is increased, and the occurrence of scratches due to scratching or rubbing, flying of small stones or the like is further prevented, and It is excellent in adhesion to a support mainly composed of polyphenylene ether or polyolefin. By suppressing the occurrence of scratches and improving weather resistance, it is possible to effectively improve peeling resistance, shape stability, and adhesion durability when exposed to a hot and humid environment, which are easily deteriorated by the influence of heat or moisture. In addition, when the ratio of the (poly)oxyl structural unit is 85% by mass or less, the coating liquid can be stabilized when the fluorenone-containing polymer layer is formed by coating, and the obtained fluorenone-based polymer layer can be obtained. The surface is getting better. From the viewpoint of production cost, the ratio of the (poly)pyroxene structural unit is preferably 50% by mass or less.

In the case where the above fluorenone-based polymer in the present invention is a copolymerized polymer having a (poly)oxyl structural unit and another structural unit, it is preferred to have a mass ratio of 15% by mass to 99 in the molecular chain. The (poly)oxyl structural unit represented by the above formula (1) and the non-oxyalkylene-based structural unit having a mass ratio of 85% by mass to 1% by mass. By containing such a copolymerized polymer, the film strength of the polymer layer is improved, and the occurrence of scratches caused by scratching or rubbing or the like can be prevented, and the polymer support which becomes the support is drastically improved as compared with the prior art or The adhesion of the fluorine-containing polymer layer, that is, the peeling resistance, the shape stability, and the durability in a hot and humid environment which are easily deteriorated by the influence of heat or moisture.

The above copolymerized polymer is preferably a block copolymer which is a oxoxane compound (including polysiloxane) and is selected from a non-oxyalkylene monomer or a non-oxyalkylene polymer. The compound is copolymerized and has a (poly)oxyl structural unit represented by the above formula (1) and a non-oxyalkylene-based structural unit. In this case, the siloxane compound and the non-oxyalkylene monomer or the non-oxyalkylene polymer to be copolymerized may be used alone or in combination of two or more.

The non-oxyalkylene-based structural unit (derived from a non-oxyalkylene-based monomer or a non-oxyalkylene-based polymer) copolymerized with the above (poly)oxyl structural unit has no structure other than a decane structure. It is particularly limited and may be any one of polymer segments derived from any polymer. Examples of the polymer (precursor) which is a precursor of the polymer segment include various polymers such as a vinyl polymer, a polyester polymer, and a polyurethane polymer.

Among them, in terms of ease of preparation and excellent hydrolysis resistance, it is preferred. The ethylene-based polymer and the polyurethane-based polymer are particularly preferably ethylene-based polymers.

Representative examples of the vinyl polymer include various polymers such as an acrylic polymer, a vinyl carboxylate polymer, an aromatic vinyl polymer, and a fluoroolefin polymer. Among them, from the viewpoint of the degree of freedom in design, an acrylic polymer is particularly preferred.

Further, the polymer constituting the non-oxyalkylene-based structural unit may be used alone or in combination of two or more.

Further, the precursor polymer which is a non-oxyalkylene-based structural unit preferably contains at least one acid group and/or a hydrolyzable alkyl group having an acid group and a neutralized acid group. Among such precursor polymers, the vinyl polymer can be produced, for example, by various methods such as (a) a vinyl group containing an acid group and an ethylene series containing a hydrolyzable alkylene group and/or a stanol group. a method of copolymerizing a monomer copolymerizable with the monomers; (2) reacting the polycarboxylic acid anhydride with a previously prepared vinyl polymer having a hydroxyl group and a hydrolyzable alkylene group and/or a stanol group (3) A method of reacting a previously prepared ethylene-based polymer having an acid anhydride group and a hydrolyzable alkylene group and/or a stanol group with a compound having active hydrogen (water, an alcohol, an amine, etc.).

The precursor polymer can be produced and obtained, for example, by the method described in Paragraph No. 0021 to Paragraph No. 0078 of JP-A-2009-52011.

The above fluorenone-containing polymer layer in the present invention may be used alone or as a binder together with the other fluorenone polymer. In the case where other polymers are used in combination, the structure of the present invention containing a (poly)oxyl structure The content ratio of the fluorenone-based polymer is preferably 30% by mass or more, and more preferably 60% by mass or more based on the total binder. When the content ratio of the polymer containing a (poly) azide structure is 30% by mass or more, it is more excellent in adhesion to a polymer support or a fluorine-containing polymer layer and durability in a hot and humid environment.

The molecular weight of the above fluorenone polymer is preferably 5,000 to 100,000, more preferably 10,000 to 50,000.

In the preparation of the above fluorenone-based polymer, a method such as (i) a method of reacting a precursor polymer with a polysiloxane having the structural unit represented by the above formula (1); (ii) A method of hydrolyzing and condensing a decane compound having a structural unit represented by the above formula (1) wherein R ¹ and/or R ² is a hydrolyzable group in the presence of a precursor polymer.

The decane compound used in the method (ii) above may be exemplified by various decane compounds, and more preferably an alkoxy decane compound.

When the above anthrone-based polymer is produced by the method (i) above, for example, it can be prepared by adding water and a catalyst as needed in a mixture of a precursor polymer and a polyoxyalkylene oxide. The reaction is carried out at a temperature of about 20 ° C to 150 ° C for about 30 minutes to 30 hours (preferably from 1 hour to 20 hours at 50 ° C to 130 ° C). As the catalyst, various stanol condensation catalysts such as an acidic compound, a basic compound, and a metal-containing compound can be added.

Further, in the case of preparing the above fluorenone polymer by the method of the above (ii), it can be produced, for example, by adding water and stanol to a mixture of a precursor polymer and an alkoxydecane compound. The condensation catalyst is hydrolyzed at a temperature of from 20 ° C to 150 ° C for about 30 minutes to 30 hours (preferably from 1 hour to 20 hours at 50 ° C to 130 ° C). condensation.

The above anthrone-based polymer having a (poly)oxyl structure is preferably a composite polymer in which the polyoxyalkylene segment contains dimethyldimethoxydecane/γ-methyl. Any of the hydrolysis condensates of propylene methoxyoxytrimethoxydecane or the hydrolysis condensate of dimethyldimethoxydecane/diphenyldimethoxydecane/γ-methylpropenyloxytrimethoxydecane And the polymer moiety copolymerized with the polyoxyalkylene segment comprises a component selected from the group consisting of ethyl acrylate, butyl acrylate, hydroxyethyl acrylate, 2-ethylhexyl acrylate methyl methacrylate, methyl An acrylic polymer of a monomer component of methyl acrylate, butyl methacrylate, hydroxyethyl methacrylate, acrylic acid or methacrylic acid; particularly preferably a polyoxyalkylene segment is dimethyldimethoxy Composite polymerization of a hydrolyzed condensate of decane/γ-methacryloxymethoxytrimethoxydecane with an acrylic polymer comprising a monomer component selected from the group consisting of methyl methacrylate, ethyl acrylate, acrylic acid, and methacrylic acid Things.

Further, as the above-mentioned anthrone-based polymer having a (poly)oxyl structure, a commercially available product can be used. For example, a Ceranate series manufactured by DIC (for example) can be used (for example, Celanate (Ceranate) ) HSA series (H7650, H7630, H7620, etc.) manufactured by Asahi Kasei Chemicals Co., Ltd., WSA1070, Ceranate (WSA1060, etc.), and inorganic-acrylic composite emulsions produced by JSR (shares).

The content ratio of the above-described fluorenone-based polymer having a (poly)oxyl structure in the fluorenone-containing polymer layer is preferably in a range of more than 0.2 g/m ² and not more than 15 g/m ² . When the content ratio of the polymer is 0.2 g/m ² or more, the ratio of the above fluorenone-based polymer becomes sufficient, and the scratch resistance can be improved. In addition, when the content ratio of the fluorenone-based polymer is 15 g/m ² or less, the ratio of the fluorenone-based polymer is not excessive, and the curing of the fluorenone-containing polymer layer is sufficient.

In the above range, from the viewpoint of the surface strength of the fluorenone-containing polymer layer, it is preferably in the range of 0.5 g/m ² to 10.0 g/m ² , more preferably 1.0 g/m ² to 5.0 g/ The range of m ² .

-UV absorber -

Examples of the ultraviolet absorber include a compound that absorbs ultraviolet light and converts it into heat, a material that absorbs ultraviolet light and decomposes it, and a material that suppresses decomposition and chain reaction. By containing these compounds, strength deterioration, peeling, color tone change, and the like are prevented even when the exposure is continued for a long period of time.

The ultraviolet absorber to be used in the above fluorenone-containing polymer layer in the present invention is not particularly limited, and any of organic or inorganic ultraviolet absorbers may be used, or these may be used in combination. The ultraviolet absorber is preferably preferably excellent in moist heat resistance and uniformly dispersed in the polymer layer.

Examples of the ultraviolet absorber include an ultraviolet absorber such as salicylic acid, benzophenone, benzotriazole, cyanoacrylate or triazine, and are blocked. A UV stabilizer such as an amine system.

Specifically, examples of the salicylic acid-based ultraviolet absorber include salicylic acid-p-tert-butylphenyl ester, salicylic acid-p-octylphenyl ester, and the like.

Examples of the benzophenone-based ultraviolet absorber include 2,2-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, and 2-hydroxy-4-methoxy-5-sulfonate. base Benzophenone, 2,2',4,4'-tetrahydroxybenzophenone, bis(2-methoxy-4-hydroxy-5-benzimidylphenyl)methane, and the like.

Examples of the benzotriazole-based ultraviolet absorber include 2-(2'-hydroxy-5'-methylphenyl)benzotriazole and 2-(2'-hydroxy-5'-methylphenyl)benzene. And triazole, 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H benzotriazol-2-yl)phenol] and the like.

Examples of the cyanoacrylate-based ultraviolet absorber include ethyl-2-cyano-3,3'-diphenylacrylate.

Examples of the triazine-based ultraviolet absorber include 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-[(hexyl)oxy]-phenol.

Examples of the hindered amine-based ultraviolet stabilizer include bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate and dimethyl succinate-1-(2-hydroxyethyl). a -4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate or the like.

Further, examples thereof include bis(octylphenyl)sulfide nickel and 2,4-di-t-butylphenyl-3',5'-di-t-butyl-4'-hydroxybenzoate.

Further, examples of the inorganic ultraviolet absorber include fine particles such as titanium oxide and cerium oxide.

Among the above, a triazine-based ultraviolet absorber is more preferable in terms of high resistance to ultraviolet light absorption. Further, the ultraviolet absorber or the ultraviolet stabilizer may be contained in the fluorenone-containing polymer layer as a monomer, or may be introduced into the organic system in a form of copolymerization with a monomer having ultraviolet absorbing ability. In a conductive material or a water-insoluble resin.

The content of the ultraviolet absorber in the fluorenone-containing polymer layer is preferably 2 in terms of all the binders of the fluorenone-containing polymer layer. The product is more than 100% by volume, more preferably 10% by volume or more and 60% by volume or less.

When the content of the ultraviolet absorber is 2% by volume or more based on all the binders of the fluorenone-based polymer layer, it is possible to suppress cracks or warpage of the support caused by deterioration over a long period of time. Peeling or the like of the layer formed by coating or the like can suppress, for example, a decrease in the adhesion between the coating layer formed by coating or the like. In addition, when the content of the ultraviolet absorber is 100% by volume or less based on all the binders of the fluorenone-based polymer layer, it is advantageous in terms of adhesion after coating a surface or a damp heat.

Here, the content (% by volume) of the ultraviolet absorber in each polymer layer can be calculated by the following formula.

UV absorber content (% by volume) = volume of UV absorber / volume of all binders

In addition, the volume of the ultraviolet absorber or the binder can be measured, and the volume of the ultraviolet absorber can be calculated by calculating the specific gravity of the ultraviolet absorber/the specific gravity of the ultraviolet absorber, and the mass of the binder/specific gravity of the binder can be calculated to determine the volume of the binder. .

The content of the ultraviolet absorber in the fluorenone-containing polymer layer is preferably in the range of 0.2 g/m ² to 5 g/m ² , and more preferably in the range of 0.3 g/m ² to 4 g/m ² . More preferably, it is set to a range of 0.3 g/m ² to 3.5 g/m ² .

-White pigment -

In view of the improvement of the light-reflecting function or the light-resistance, the fluorenone-containing polymer layer of the present invention preferably contains a white pigment in addition to the fluorenone-based polymer. Further, the white pigment may also function as the above ultraviolet absorber.

The above white pigment is preferably titanium dioxide, barium sulfate, cerium oxide, aluminum oxide, magnesium oxide, calcium carbonate, kaolin, talc or the like.

The function of the layer containing the white pigment may be as follows: first, the incident light is reflected by the solar cell that is not used for power generation and reaches the backing plate, and is returned to the solar cell unit, thereby improving the solar cell module. Power generation efficiency; secondly, the decorative appearance of the appearance of the solar cell module when viewed from the side (surface side) on which the sunlight is incident is improved. Generally, when the solar cell module is viewed from the surface side, a backing plate is visible around the solar cell unit, and by providing a layer containing a white pigment on the backing plate, the decorative property can be improved and the appearance can be improved.

By further containing the white pigment in addition to the above-described anthrone-based polymer, the reflectance of the polymer sheet can be improved, and the long-term high-temperature and high-humidity test can be reduced (85 ° C, relative humidity of 85%) Yellowing under 2000 hours to 4000 hours) and ultraviolet (Ultraviolet, UV) irradiation test (UV test according to IEC61215, total irradiation amount is 45 Kwh/m ² ). Further, by adding a white pigment to the fluorenone-containing polymer layer, the adhesion to other layers can be further improved.

In the polymer sheet of the present invention, the content of the white pigment contained in the fluorenone-containing polymer layer is preferably from 0.1 g/m ² to 15 g/m ^{2 based on} about one layer of the polymer layer. When the content of the white pigment is 0.1 g/m ² or more, reflectance or UV resistance (light resistance) can be effectively imparted. In addition, when the content of the white pigment in the fluorenone-containing polymer layer is 15 g/m ² or less, the surface of the colored layer is easily maintained, and the film strength is further improved. The content of the white pigment contained in the fluorenone-containing polymer layer is preferably in the range of 1.0 g/m ² to 10 g/m ² with respect to about one layer of the polymer layer, and particularly preferably 3 g/ The range of m ² ~ 8.5 g/m ² .

The average particle diameter of the white pigment is preferably from 0.03 μm to 0.8 μm, more preferably from about 0.15 μm to 0.5 μm, in terms of volume average particle diameter. When the average particle diameter is within the above range, the light reflection efficiency is high. The average particle diameter is a value measured by a laser analysis/scattering particle size distribution measuring apparatus LA950 [manufactured by Horiba, Ltd.].

The content of the binder component (including the above fluorenone polymer) in the fluorenone-containing polymer layer is preferably in the range of 15% by mass to 200% by mass, and more preferably 17% by mass to 100% by weight based on the white pigment. The range of mass %. When the content of the binder is 15% by mass or more, the strength of the colored layer can be sufficiently obtained, and if it is 200% by mass or less, the reflectance or the decorative property can be favorably maintained.

- other components of the fluorenone-containing polymer layer -

The other component which can be contained in the above-mentioned anthrone-containing polymer layer may, for example, be a crosslinking agent, a surfactant, a filler or the like.

(crosslinking agent)

The above-described fluorenone-containing polymer layer is formed by adding a crosslinking agent to a binder (adhesive resin) mainly constituting the fluorenone-based polymer layer, and a crosslinked structure derived from a crosslinking agent can be obtained.

Examples of the crosslinking agent include an epoxy system, an isocyanate system, and a melamine system. A crosslinking agent such as a carbodiimide or an oxazoline. Among these, a carbodiimide type and an oxazoline type crosslinking agent are preferable. Specific examples of the carbodiimide-based or oxazoline-based crosslinking agent include a carbodiimide crosslinking agent such as Carbodilite V-02-L2 (manufactured by Nisshin Textile Co., Ltd.). Examples of the oxazoline crosslinking agent include Epocros WS-700 and Epocros K-2020E (both manufactured by Nippon Shokubai Co., Ltd.).

Preferably, the polymer sheet for a solar cell module of the present invention is characterized in that the component derived from the crosslinking agent containing the fluorenone-based polymer layer is derived from an oxazoline-based crosslinking agent and a carbodiimide-based crosslinking agent. A component of at least one crosslinking agent in the crosslinking agent.

The polymer sheet for a solar cell module of the present invention preferably contains at least one of the fluorenone-containing polymer layer and the fluorine-containing polymer layer in an amount of 3% by mass based on all the binders in each polymer layer. ~30% by mass of the component derived from the crosslinking agent, more preferably 3% by mass to 25% by mass. When the amount of the crosslinking agent to be added is 3% by mass or more, the strength of the fluorenone-containing polymer layer and the adhesion after the aging of the wet heat can be maintained, and a sufficient crosslinking effect can be obtained, and if it is 25% by mass or less, The application period of the coating liquid can be kept long.

(surfactant)

As the surfactant, a known surfactant such as an anionic or nonionic surfactant can be used. In the case of adding a surfactant, the amount thereof is preferably from 0.1 mg/m ² to 10 mg/m ² , more preferably from 0.5 mg/m ² to 3 mg/m ² . When the amount of the surfactant added is 0.1 mg/m ² or more, a favorable layer can be formed by suppressing generation of repulsion, and if it is 10 mg/m ² or less, the polymer support and the fluoropolymer can be favorably formed. The next layer.

(filler)

A filler may be further added to the above fluorenone-containing polymer layer. As the filler, a known filler such as colloidal cerium oxide or titanium oxide can be used.

The amount of the filler added is preferably 20% by mass or less, and more preferably 15% by mass or less based on the binder of the fluorenone-containing polymer layer. When the amount of the filler added is 20% by mass or less, the surface of the undercoat layer is kept better.

- Thickness of the fluorenone-containing polymer layer -

The thickness of the layer containing the fluorenone-based polymer layer is usually preferably 0.3 μm to 15 μm, more preferably 0.5 μm to 12 μm, still more preferably 0.8 μm to 10 μm, and particularly preferably 1.0 μm to 8 μm. When the thickness of the polymer layer is 0.3 μm or more, it is 0.8 μm or more. When exposed to a hot and humid environment, moisture does not easily penetrate from the surface of the polymer layer to the inside, and moisture does not easily reach the above-mentioned fluorenone-containing polymer layer and the polymer support. The interface, thus the connectivity is significantly improved. In addition, when the thickness of the fluorenone-containing polymer layer is 15 μm or less and further 12 μm or less, the polymer layer itself is less likely to be weak, and when it is exposed to a hot and humid environment, the polymer layer is less likely to be broken, whereby the adhesion is obtained. improve.

- Formation of an fluorenone-containing polymer layer -

The fluorenone-containing layer can be formed by applying a coating liquid containing a binder or the like to a polymer support and drying it. After drying, it can be hardened by heating or the like. There is no particular limitation on the coating method or the solvent of the coating liquid to be used.

The coating method can be, for example, a gravure coater or a bar coater.

The solvent used in the coating liquid may be water or an organic solvent such as toluene or methyl ethyl ketone. The solvent may be used singly or in combination of two or more. It is preferred to form a water-based coating liquid obtained by dispersing a binder in water and applying the aqueous coating liquid. In this case, the proportion of water in the solvent is preferably 60% by mass or more, and more preferably 80% by mass or more.

Further, in the case where the polymer support is a biaxially stretched film, the coating film for forming the above fluorenone-containing layer may be applied onto the biaxially stretched polymer support to dry the coating film. Alternatively, the method may be a method in which a coating liquid is applied onto a polymer support after uniaxial stretching and the coating film is dried, and then stretched in a direction different from the initial stretching. Further, the coating liquid may be applied onto the polymer support before stretching, and the coating film may be dried to extend in both directions.

<Fluorinated polymer layer>

The polymer sheet of the present invention has a fluorine-containing polymer layer which is disposed on the fluorenone-containing polymer layer and contains a fluorine-based polymer as a binder, and the fluorine-containing polymer layer is opposite to the fluorine-containing polymer layer. All the binders in the fluorine-containing polymer layer contain 0.01% by mass or more of an organic solvent.

The fluorine-containing polymer layer is preferably directly provided on the fluorenone-containing polymer layer. The fluorine-containing polymer layer as the fluoropolymer layer is composed of a fluorine-based polymer (fluoropolymer) as a main binder. The term "primary binder" refers to the binder having the most content in the fluoropolymer layer. The fluorine-containing polymer layer will be specifically described below.

-Fluoropolymers -

The fluorine-based polymer used in the fluorine-containing polymer layer is not particularly limited as long as it is a polymer having a repeating unit represented by -(CFX ¹ -CX ² X ³ )- (wherein X ¹ and X ^{2 )} And X ³ represents a hydrogen atom, a fluorine atom, a chlorine atom or a perfluoroalkyl group having a carbon number of 1 to 3. Specific examples of the polymer include polytetrafluoroethylene (hereinafter sometimes referred to as PTFE), polyvinyl fluoride (hereinafter sometimes referred to as PVF), polyvinylidene fluoride (hereinafter sometimes referred to as PVDF), and polychlorinated trichloride. Ethylene fluoride (hereinafter sometimes referred to as PCTFE), polytetrafluoropropene (hereinafter sometimes referred to as HFP), and the like.

These polymers may be a homopolymer obtained by polymerizing a single monomer, or may be obtained by copolymerizing two or more kinds. Examples thereof include a copolymer obtained by copolymerizing tetrafluoroethylene and tetrafluoropropene (abbreviated as P(TFE/HFP)), and a copolymer obtained by copolymerizing tetrafluoroethylene and vinylidene fluoride (abbreviated as P(TFE/VDF)) and the like.

Further, the polymer used in the fluorine-containing polymer layer may be a polymer obtained by copolymerizing a fluorine-based monomer represented by -(CFX ¹ -CX ² X ³ )- with a monomer other than the above. . Examples of such may include a copolymer of tetrafluoroethylene and ethylene (abbreviated as P(TFE/E)), a copolymer of tetrafluoroethylene and propylene (abbreviated as P(TFE/P)), tetrafluoroethylene and ethylene. a copolymer of ether (abbreviated as P(TFE/VE)), a copolymer of tetrafluoroethylene and perfluorovinyl ether (abbreviated as P(TFE/FVE)), a copolymer of chlorotrifluoroethylene and vinyl ether (abbreviated as P(CTFE/VE)), a copolymer of chlorotrifluoroethylene and perfluorovinyl ether (abbreviated as P(CTFE/FVE)).

Specifically, it is preferably a trifluoroethylene chloride/perfluoroethyl vinyl ether copolymer, a trifluoroethylene chloride/perfluoroethyl vinyl ether/methacrylic acid copolymer. , ethylene trifluoride/ethyl vinyl ether copolymer, ethylene trifluoride/ethyl vinyl ether/methacrylic acid copolymer, vinylidene fluoride/methyl methacrylate/methacrylic acid copolymer A vinyl fluoride/ethyl acrylate/acrylic acid copolymer, particularly preferably a trifluoroethylene chloride/perfluoroethyl vinyl ether/methacrylic acid copolymer or a trifluoroethylene/ethyl vinyl ether copolymer.

As the fluorine-based polymer, the polymer may be used by dissolving the polymer in an organic solvent, or may be used by dispersing the polymer fine particles in water. In terms of a small environmental load, the latter is preferred. The water-dispersion of the fluorine-based polymer is described, for example, in JP-A-2003-231722, JP-A-2002-220409, JP-A-H09-194538, and the like.

Further, the above fluorine-based polymer is also commercially available. For example, in the present invention, it is preferable to use Lumiflon LF200 (made by Asahi Glass Co., Ltd.) and Zeffle GK-570 (large Gold Industrial Co., Ltd., Obbligato SW0011F (Fluorine-based adhesive, manufactured by AGC Coat-tech).

The fluorine-based polymer may be used singly as the binder of the fluorine-containing polymer layer, or two or more kinds thereof may be used in combination. In addition, a resin other than the fluorine-based polymer such as an acrylic resin, a polyester resin, a polyurethane resin, a polyolefin resin, or an anthrone resin may be used in an amount not exceeding 50% by mass of all the binders. However, when the resin other than the fluorine-based polymer exceeds 50% by mass, the weather resistance may be lowered in the case of use in a back sheet.

The content ratio of the fluorine-based polymer in the fluorine-containing polymer layer is preferably in the range of 50% to 95%. If the above fluorine-containing polymer is contained When the ratio is 50% or more, the weather resistance can be improved. In addition, when the content ratio of the fluorine-based polymer is 95% or less, the ratio of the fluorine-based polymer is not excessive, and the adhesion of the fluorine-containing polymer layer is sufficient.

In the above range, from the viewpoint of the surface strength of the fluorine-containing polymer layer, it is preferably in the range of 60% to 93%, more preferably in the range of 70% to 90%.

-Other additives -

In the fluorine-containing polymer layer, a crosslinking agent, a surfactant, an ultraviolet absorber, or the like may be added as needed. Further, a matting agent, an organic lubricant, a decane coupling agent or the like may be added.

(crosslinking agent)

By adding a crosslinking agent to the fluorine-containing polymer layer to form a fluorine-containing polymer layer, a crosslinked structure derived from a crosslinking agent can be obtained.

The crosslinking agent used for the fluorine-containing polymer layer may, for example, be a crosslinking agent such as an epoxy-based, isocyanate-based, melamine-based, carbodiimide-based or oxazoline-based. Examples of the carbodiimide crosslinking agent are, for example, Carbodilite V-02-L2 (manufactured by Nisshin Textile Co., Ltd.), and examples of the oxazoline crosslinking agent are, for example, Epoques ( Epocros) WS-700, Epocros K-2020E (all manufactured by Japan Catalyst). The above isocyanate-based crosslinking agent is preferably a blocked isocyanate, more preferably an isocyanate blocked with dimethylpyrazole, and particularly preferably an isocyanate blocked with 3,5-dimethylpyrazole. The above-mentioned isocyanate-based crosslinking agent which can be preferably used in the present invention is, for example, a DP9C/214 of the Trixene series manufactured by Baxenden, or the same as Bassington. (Baxenden) company made BI7986 and so on.

The polymer sheet for a solar cell module of the present invention preferably contains at least one of the fluorenone-containing polymer layer and the fluorine-containing polymer layer in an amount of 3% by mass based on all the binders in each polymer layer. ~30% by mass of a component derived from a crosslinking agent.

In the polymer sheet for a solar cell module of the present invention, it is preferable that the component derived from the crosslinking agent of the fluorine-containing polymer layer is a component derived from an isocyanate crosslinking agent.

(surfactant)

A known surfactant such as an anionic or nonionic surfactant can be used as the surfactant used in the fluorine-containing polymer layer. In the case of adding a surfactant, the amount thereof is preferably from 0 mg/m ² to 15 mg/m ² , more preferably from 0.5 mg/m ² to 5 mg/m ² . When the amount of the surfactant added is 0.1 mg/m ² or more, generation of repulsion can be suppressed to form a favorable layer, and if it is 15 mg/m ² or less, the subsequent step can be favorably performed.

(UV absorber)

The ultraviolet absorber used in the fluorine-containing polymer layer is the same as the ultraviolet absorber used in the above-described anthranone-containing polymer layer, and the preferred range is also the same.

(Characteristics of fluorine-containing polymer layer)

The thickness of the fluorine-containing polymer layer is preferably in the range of 0.8 μm to 12 μm. When the thickness of the fluoropolymer layer is 0.8 μm or more, the durability of the polymer sheet for a solar cell, particularly the outermost layer (weather resistance) is sufficient, and when the thickness of the fluoropolymer layer is 12 μm or less, the surface is sufficient. Not easy The adhesion to the above fluorenone-containing polymer layer is sufficient. When the thickness of the fluorine-containing polymer layer is in the range of 0.8 μm to 12 μm, it can have both durability and a planar shape, and particularly preferably in the range of about 1.0 μm to 10 μm.

The polymer sheet of the present invention can further laminate other layers on the fluoropolymer layer as the fluorine-containing polymer layer, and the durability of the polymer sheet for a back sheet can be improved, reduced in weight, thinned, and low in cost. From the viewpoint of chemistry or the like, it is preferred that the fluoropolymer layer be the outermost layer of the polymer sheet for the back sheet.

In the polymer sheet of the present invention, the fluorine-containing polymer layer contains 0.01% by mass or more of an organic solvent with respect to all the binders in the fluorine-containing polymer layer.

In the present specification, the organic solvent contained in the fluorine-containing polymer layer means an organic compound having a boiling point of 50 ° C or higher and a liquid at room temperature. The organic solvent contained in the fluorine-containing polymer layer preferably has a boiling point of from 50 ° C to 210 ° C, more preferably from 60 ° C to 160 ° C. Further, the organic solvent contained in the fluorine-containing polymer layer preferably has a molecular weight of 55 to 140, more preferably 60 to 130.

In the present specification, the amount of residual solvent (referred to as the amount of residual organic solvent) in the fluorine-containing polymer layer is measured by the following method.

The sample coated with the fluorine-containing polymer layer was cut into a size of 10 cm × 10 cm, and immersed in methanol (ethanol in the case where methanol was used as a solvent), and the residual solvent was extracted.

The extracted residual solvent was quantified using gas chromatography.

Gas Chromatograph: GC-2010 manufactured by Shimadzu Corporation

Pipe column: manufactured by Agilent Technologies DB Wax

Further, the same sample was cut into a size of 10 cm × 10 cm, and the weight W1 was measured after conditioning at 25 ° C and a relative humidity of 60% for 24 hours. Thereafter, the fluorine-containing polymer layer was removed using a coating solvent.

The sample was conditioned at 25 ° C and a relative humidity of 60% for 24 hours, and then the weight W2 was measured.

The difference between W1 and W2 was taken as the weight of the fluorine-containing polymer layer of 100 cm ² .

The amount of residual solvent can be determined from the amount of residual solvent measured by gas chromatography and the weight of the fluorine-containing polymer layer.

In the case where two or more kinds of coating solvents are used, the total amount thereof is used as the residual solvent amount of the sample.

The amount of the residual solvent in the fluorine-containing polymer layer is preferably from 0.08% by mass to 2.5% by mass, more preferably from 0.1% by mass to 2.0% by mass.

The fluorine-containing polymer layer is preferably formed by applying a coating liquid containing an organic solvent as a coating solvent, and drying the coating film. After drying, it can be hardened by heating or the like. The solvent of the coating method or the coating liquid is not particularly limited.

The coating method can be, for example, a gravure coater or a bar coater.

The solvent used in the coating liquid for forming a fluorine-containing polymer layer may be water, or may be an organic solvent such as toluene or methyl ethyl ketone, but contains at least one organic solvent. The solvent may be used singly or in combination of two or more.

<Other polymer layers>

The polymer sheet of the present invention may have the above-described fluorenone-containing polymer layer and other polymer layers other than the above-described fluorine-containing polymer layer as long as it does not contradict the gist of the present invention.

The polymer sheet of the present invention preferably has a pigment-containing coloring layer on the surface of the support opposite to the surface on which the fluorenone-based polymer layer and the fluorine-containing polymer layer are provided.

(colored layer)

The colored layer preferably contains a pigment and a binder. Further, it is more preferable that the colored layer has a peeling force of 5 N/cm or more for the sealing material of the solar cell module.

-polymer-

In view of the fact that the adhesion of the EVA or the like used as the sealing material for the solar cell module is set to 5 N/cm or more, the colored layer is preferably selected from the group consisting of polyolefin resin and acrylic resin. One or more polymers of a resin or a polyvinyl alcohol resin are used as a binder. Among them, from the viewpoint of durability, an acrylic resin or a polyolefin is preferable.

As an example of a preferable binder, specific examples of the polyolefin include Chemipearl S-120 and S-75N (all manufactured by Mitsui Chemicals Co., Ltd.), and specific examples of the acrylic resin can be exemplified by Zhuang Li. Jurymer ET-410, SEK-301 (both manufactured by Nippon Pure Chemicals Co., Ltd.).

The content of the binder in the colored layer is preferably in the range of 0.05 g/m ² to 5 g/m ² . More preferably, it is in the range of 0.08 g/m ² to 3 g/m ² . When the content of the binder is 0.05 g/m ² or more, the desired adhesion is easily obtained, and when it is 5 g/m ² or less, a good surface shape can be obtained.

The adhesion of the colored layer to the EVA used as the sealing material of the solar cell module is preferably 5 N/cm or more, more preferably more than 30 N/cm, and more preferably 50 N/cm to 150 N/cm.

-pigment-

The colored layer preferably contains at least one pigment.

For the pigment, for example, an inorganic pigment such as titanium oxide, barium sulfate, cerium oxide, aluminum oxide, magnesium oxide, calcium carbonate, kaolin, talc, ultramarine blue, iron blue or carbon black, or an organic pigment such as phthalocyanine blue or phthalocyanine green may be selected.

In the case where the colored layer is formed as a reflection layer which is incident on the solar cell and reflected by the solar cell and returned to the solar cell, the pigment is preferably a white pigment. The white pigment is preferably titanium dioxide, barium sulfate, cerium oxide, aluminum oxide, magnesium oxide, calcium carbonate, kaolin, talc or the like.

The polymer sheet of the present invention preferably has a volume fraction of the pigment relative to the colored layer of 15% to 50%, more preferably 18% to 30%, particularly preferably 20% to 25%. When the volume fraction of the pigment with respect to the colored layer is 15% or more, a favorable coating surface shape can be obtained, and a sufficient reflectance can be obtained. On the other hand, when the volume fraction of the pigment with respect to the colored layer is 50% or less, aggregation failure due to insufficient strength of the colored layer is less likely to occur, and adhesion of the colored layer to the sealing material or coloring and undercoating The adhesion between the layers is preferably good both before and after the damp heat. In the case where the volume fraction of the pigment with respect to the colored layer is 50% or less, the colored layer is brittle, and peeling is likely to occur. However, by setting the composition of the present invention, the volume fraction is set to 50%, even if the colored layer is brittle, The adhesion to the sealing material of the solar cell module or the undercoat layer described later also becomes good.

Here, the volume fraction of the pigment in each polymer layer can be calculated by the following formula.

Volume fraction of pigment (%) = volume of pigment / (binder volume + volume of pigment)

In addition, the volume of the pigment or the binder can be measured, and the pigment mass/pigment specific gravity can be separately calculated to determine the volume of the pigment, and the binder mass/binder specific gravity can be calculated to determine the volume of the binder.

The content of the pigment in the colored layer is preferably in the range of 3 g/m ² to 18 g/m ² , more preferably in the range of 3.5 g/m ² to 15 g/m ² , particularly preferably 4.5 g/m ² to 10 g. The range of /m ² . When the content of the pigment is 3.0 g/m ² or more, necessary coloring can be obtained, and reflectance or decorative property can be effectively imparted. In addition, when the content of the pigment in the colored layer is 18 g/m ² or less, it is easy to maintain the planar shape of the colored layer, and the film strength is further improved.

The average particle diameter of the pigment is preferably from 0.03 μm to 0.8 μm, more preferably from about 0.15 μm to about 0.5 μm, in terms of volume average particle diameter. When the average particle diameter is within the above range, the light reflection efficiency is high. The average particle diameter is a value measured by a laser analysis/scattering particle size distribution measuring apparatus LA950 [manufactured by Horiba, Ltd.].

In the case where a white layer is provided as the above colored layer, the light reflectance at 550 nm of the surface (outermost surface) provided on the side of the white layer is preferably 75%. More preferably, it is 80% or more. In the case where the polymer sheet of the present invention is used as a back sheet for a solar cell, the light reflectance is reflected from the side of the sealing material of the solar cell module through the colored layer and again from the sun. The ratio of the amount of light emitted from the sealing material side of the battery module to the amount of incident light. Here, light having a wavelength of 550 nm is used as the representative wavelength light.

When the light reflectance is 75% or more, light incident on the inside through the cell can be efficiently returned to the cell, and the effect of improving power generation efficiency is large. The light reflectance can be adjusted to 75% or more by controlling the content of the white pigment to, for example, a range of 2.5 g/m ² to 30 g/m ² .

In the colored layer, a crosslinking agent, a surfactant, a filler, or the like may be added as needed.

-crosslinker -

In the present invention, it is preferred that the colored layer has a structural portion derived from a crosslinking agent which crosslinks the above polymer.

The crosslinking agent may, for example, be a crosslinking agent such as an epoxy-based, isocyanate-based, melamine-based, carbodiimide-based or oxazoline-based. By crosslinking by a crosslinking agent, it is possible to further improve the adhesion after the moist heat elapsed time, specifically, the adhesion to an adjacent material such as a sealing material when exposed to a moist heat environment.

The crosslinking agent may, for example, be a crosslinking agent such as an epoxy-based, isocyanate-based, melamine-based, carbodiimide-based or oxazoline-based. Among the crosslinking agents, a crosslinking agent such as a carbodiimide compound or an oxazoline compound is preferable.

Specific examples of the above oxazoline crosslinking agent include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, and 2-vinyl-5-methyl group. -2-oxazole Porphyrin, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, 2, 2'-bis-(2-oxazoline), 2,2'-methylene-bis-(2-oxazoline), 2,2'-extended ethyl-bis-(2-oxazoline) , 2,2'-trimethylene-bis-(2-oxazoline), 2,2'-tetramethylene-bis-(2-oxazoline), 2,2'-hexamethylene- Bis-(2-oxazoline), 2,2'-octamethylene-bis-(2-oxazoline), 2,2'-extended ethyl-bis-(4,4'-dimethyl -2-oxazoline), 2,2'-p-phenyl-bis-(2-oxazoline), 2,2'-meta-phenyl-bis-(2-oxazoline), 2, 2'-meta-phenyl-bis-(4,4'-dimethyl-2-oxazoline), bis-(2-oxazolinylcyclohexane) sulfide, bis-(2-oxazole Lolinyl norbornene) thioether and the like. Further, a (co)polymer of these compounds can also be preferably used.

In addition, compounds having an oxazoline group can also utilize Epocros K2010E, Epocros K2020E, Epocros K2030E, Epocros WS-500, Epocros WS-700 (all manufactured by Japan Catalyst Chemical Industry Co., Ltd.).

Specific examples of the above-described carbodiimide-based crosslinking agent include dicyclohexylmethane carbodiimide, tetramethylxylene carbodiimide, and dicyclohexylmethane carbodiimide. Further, the carbodiimide compound described in Japanese Laid-Open Patent Publication No. 2009-235278 is also preferred. Specifically, the carbodiimide crosslinking agent can also utilize Carbodilite SV-02, Carbodilite V-02, Carbodilite V-02-L2 Commercial products such as Carbodilite V-04, Carbodilite E-01, and Carbodilite E-02 (all manufactured by Nisshinbo Chemical Co., Ltd.).

The amount of the crosslinking agent added is preferably from 5% by mass to 50% by mass, and more preferably from 10% by mass to 40% by mass based on the binder in the layer. When the amount of the crosslinking agent added is 5% by mass or more, the strength and adhesion of the colored layer are maintained and a sufficient crosslinking effect can be obtained. When the amount is 50% by mass or less, the pot life of the coating liquid is kept long.

- surfactant -

As the surfactant, a known surfactant such as an anionic or nonionic surfactant can be used. In the case of adding a surfactant, the amount thereof is preferably from 0.1 mg/m ² to 15 mg/m ² , more preferably from 0.5 mg/m ² to 5 mg/m ² . When the amount of the surfactant added is 0.1 mg/m ² or more, generation of repulsion can be suppressed to form a favorable layer, and if it is 15 mg/m ² or less, the subsequent step can be favorably performed.

- Method of forming a colored layer -

The formation of the colored layer can be carried out by a method of bonding a polymer sheet containing a pigment, a method of coextruding a colored layer at the time of forming a substrate, a method using coating, and the like. Specifically, a coloring layer can be formed by laminating, co-extruding, coating, or the like on the surface of a support mainly composed of polyphenylene ether or polyolefin, via an undercoat layer described later.

Among the above, in terms of being simple and capable of forming a film having uniformity, it is preferred to use a coating method.

In the case of coating, the coating method can be, for example, a known coating method such as a gravure coater or a bar coater.

The coating liquid may be a water system using water as a coating solvent, or a solvent system using an organic solvent such as toluene or methyl ethyl ketone. Among them, the environment is negative From the viewpoint of the charge, it is preferred to use water as a solvent. The coating solvent may be used singly or in combination of two or more.

(primer coating)

The polymer sheet of the present invention preferably has an undercoat layer disposed between the support having the polyphenylene ether or the polyolefin as a main component and the colored layer. The thickness of the undercoat layer is preferably in the range of 2 μm or less, more preferably 0.05 μm to 2 μm, still more preferably 0.1 μm to 1.5 μm. When the thickness is 2 μm or less, the surface shape can be kept good. Further, by having a thickness of 0.05 μm or more, it is easy to ensure the necessary adhesion.

The undercoat layer preferably contains one or more polymers selected from the group consisting of polyolefin resins, acrylic resins, and polyester resins as a binder.

The polyolefin resin is preferably, for example, polyethylene or a polymer containing acrylic acid or methacrylic acid. The above polyolefin resin may also be used as a marketed product, for example, Arrowbase SE-1013N, SD-1010, TC-4010, TD-4010 (all are Unitika) ) Manufacturing), Hitec S3148, S3121, S8512 (both manufactured by Toho Chemical Co., Ltd.), Chemipearl S-120, S-75N, V100, EV210H (all Mitsui Chemicals Co., Ltd.) Manufacturing) and so on. Among them, Arbase (SE-1013N) manufactured by Unitika Co., Ltd. is preferably used.

The acrylic resin is preferably a polymer containing polymethyl methacrylate or polyethyl acrylate or the like, for example. As the acrylic resin, a commercially available product listed on the market may be used. For example, AS-563A (manufactured by Daicel Chemical Co., Ltd.) can be preferably used.

The polyester resin is preferably, for example, polyethylene terephthalate (PET) or polyethylene-2,6-naphthalate (PEN). As the above polyester resin, a commercially available product which is listed may also be used. For example, Vylonal MD-1245 (manufactured by Toyobo Co., Ltd.) can be preferably used.

Among these, it is preferable to use an acrylic resin or a polyolefin resin from the viewpoint of adhesion to a support mainly composed of polyphenylene ether or polyolefin and the colored layer. Further, these polymers may be used singly or in combination of two or more. When two or more kinds are used in combination, a combination of an acrylic resin and a polyolefin resin is preferred.

-crosslinker -

It is preferable that at least one of the undercoat layer and the fluorenone-containing polymer layer contains 0.5% by mass to 30% by mass of a crosslinking agent based on all the binders in each polymer layer.

The crosslinking agent used for the undercoat layer may, for example, be a crosslinking agent such as an epoxy-based, isocyanate-based, melamine-based, carbodiimide-based or oxazoline-based. Preferably, in the polymer sheet of the present invention, the crosslinking agent in the undercoat layer is at least selected from the group consisting of a carbodiimide crosslinking agent, an oxazoline crosslinking agent, and an isocyanate crosslinking agent. More than one crosslinking agent. The description and preferred range of the carbodiimide crosslinking agent and the oxazoline crosslinking agent which can be used in the undercoat layer are the same as those of the respective crosslinking agents which can be used in the colored layer. The description and preferred range of the isocyanate-based crosslinking agent which can be used in the undercoat layer are the same as those of the crosslinking agent used in the above-mentioned fluorine-containing polymer layer.

The amount of the crosslinking agent added is preferably relative to the binder constituting the undercoat layer. 0.5% by mass to 30% by mass, more preferably 5% by mass to 20% by mass, particularly preferably 3% by mass or more and less than 15% by mass. In particular, when the amount of the crosslinking agent added is 0.5% by mass or more, the strength and adhesion of the undercoat layer are maintained and a sufficient crosslinking effect can be obtained. When the amount is 30% by mass or less, the pot life of the coating liquid is kept long. When it is less than 15% by mass, the coated surface can be improved.

The undercoat layer preferably contains an anionic or nonionic surfactant. The range of the surfactant which can be used in the above undercoat layer is the same as the range of the surfactant which can be used in the above colored layer. Among them, a nonionic surfactant is preferred.

In the case of adding a surfactant, the amount thereof is preferably from 0.1 mg/m ² to 10 mg/m ² , more preferably from 0.5 mg/m ² to 3 mg/m ² . When the amount of the surfactant added is 0.1 mg/m ² or more, the formation of a good layer can be suppressed by suppressing the occurrence of repulsion, and if it is 10 mg/m ² or less, the polyphenylene ether or the polyolefin can be favorably carried out. The support of the component or the subsequent coloring layer.

- matting agent -

Preferably, the undercoat layer contains at least one matting agent. By including a matting agent, it is possible to further reduce the decrease in the slidability (that is, the increase in the dynamic friction coefficient) of the physical properties or the polymer layer described later.

The matting agent is preferably a particulate material, and may be any of an inorganic material or an organic material, and for example, inorganic particles or polymer microparticles may be used. Specifically, examples of the inorganic particles include metal oxides such as titanium oxide, cerium oxide, aluminum oxide, zirconium oxide, and magnesium oxide, talc, calcium carbonate, magnesium carbonate, barium sulfate, aluminum hydroxide, and kaolin. Particles such as clay.

The above polymer microparticles can be suitably exemplified by an acrylic tree. Particles such as a fat, a polystyrene resin, a polyurethane resin, a polyethylene resin, a benzoguanamine resin, or an epoxy resin. Further, it is also preferred to add a latex to the coating liquid for forming the undercoat layer. In this case, it is also preferred that the undercoat layer contains a component derived from a latex.

In the above, in the present invention, it is preferred that the undercoat layer contains at least one of polymer microparticles and a latex-derived component, and polymethyl methacrylate microparticles, ethyl acrylate latex, or the like can be preferably used.

The average particle diameter of the matting agent is preferably from 0.1 μm to 10 μm, more preferably from 0.1 μm to 8 μm, in terms of secondary particle diameter. When the secondary particle diameter of the matting agent is 10 μm or less, it is less likely to cause generation of agglomerates or repulsion failure when the polymer layer is formed by coating, and it is easy to obtain a favorable coating surface shape, which is advantageous in this respect. Further, in the case of using a latex, it is preferred that the particle diameter in the coating liquid is within the above range.

The above average particle diameter is a secondary particle diameter measured by a laser analysis/scattering type particle size distribution measuring apparatus LA950 [manufactured by Horiba, Ltd.].

The content of the matting agent in the undercoat layer is preferably in the range of 0.3 mg/m ² to 30 mg/m ² , more preferably in the range of 10 mg/m ² to 25 mg/m ² , and further preferably 15 mg/m ² to 25 mg/ The range of m ² . When the content of the matting agent is 30 mg/m ² or less, it is less likely to cause generation of agglomerates or repulsion failure when the polymer layer is formed by coating, and it is easy to obtain a favorable coating surface shape, which is advantageous in this respect.

- physical properties of the undercoat layer -

The undercoat layer preferably has a specific modulus of elasticity and elongation at break.

The undercoat layer preferably has an elastic modulus of 50 MPa to 500 MPa, more preferably 100 MPa to 250 MPa.

The undercoat layer preferably has an elongation at break of 5% to 150%, and particularly preferably 20% to 100%.

- Method of forming the undercoat layer -

The solvent for applying the above-mentioned undercoat layer as the undercoat layer or the coating liquid used is not particularly limited.

The coating method can be, for example, a gravure coater or a bar coater.

The solvent used in the coating liquid may be water or an organic solvent such as toluene or methyl ethyl ketone. The solvent may be used singly or in combination of two or more.

In addition, the coating may be applied to a biaxially stretched support containing polyphenylene ether or a polyolefin as a main component, or may be applied to a polyphenylene ether or a polyolefin after uniaxial stretching. After the support of the component, it is extended in a direction different from the initial extension. Further, it may be applied to the support before stretching and then extended in two directions.

<Method for Producing Polymer Sheet for Solar Cell Module>

The method for producing a polymer sheet for a solar cell module according to the present invention (hereinafter also referred to as a method for producing a polymer sheet of the present invention) is characterized by comprising the steps of: coating a fluorenone containing at least one side of a polymer support a coating liquid for forming an anthrone-based polymer layer as a binder, drying the coating film to form an anthrone-containing polymer layer, and coating the anthrone-containing polymer layer Fluorine-based polymer as a binder and a fluorine-containing polymer layer containing an organic solvent as a coating solvent A coating liquid was used, and the coating film was dried.

In terms of being simple and capable of forming a film having uniformity, a coating method for forming the above-described fluorenone-containing polymer layer and fluorine-containing polymer layer is preferred. In the case of coating, the coating method can be, for example, a known coating method such as a gravure coater or a bar coater.

As described above in the description of the fluorine-containing polymer layer, the coating liquid for forming a fluorine-containing polymer layer contains an organic solvent as a coating solvent. The coating liquid for forming a fluorine-containing polymer layer is preferably an organic solvent-based coating liquid, and the organic solvent-based coating liquid phase is preferably 50% by mass or more based on the total mass of the coating solvent contained therein. 60% by mass or more, more preferably 90% by mass or more, and particularly preferably 100% by mass is an organic solvent.

In addition, when the fluorine-containing polymer layer is formed by using a coating liquid containing an organic solvent as a coating solvent, it can be confirmed by the following method: the total fluorine-containing polymer layer with respect to the polymer sheet for a solar cell module. The amount of the residual solvent is 0.01% by mass or more.

In the method for producing a polymer sheet of the present invention, it is preferred that the coating liquid for forming an anthrone-containing polymer layer contains water as a coating solvent. That is, it is preferred that the aqueous dispersion of the polymer having a (poly)oxyl structure in the molecular chain is mixed with a crosslinking agent to prepare a polymerization containing a (poly)oxyl structure in water. The aqueous dispersion of the particles is applied to a desired polymer support as an aqueous coating liquid in the formation process of the fluorenone-containing polymer layer.

The coating liquid for forming an anthrone-containing polymer layer is preferably an aqueous coating liquid which is 50 with respect to the total mass of the coating solvent contained therein. The mass% or more, preferably 60% by mass or more, is water. In terms of the environmental load, the aqueous coating liquid is preferable, and the ratio of water is 50% by mass or more, and the environmental load is particularly reduced. From the viewpoint of the environmental load, the proportion of water in the coating liquid is desirably more, and it is particularly preferable that water accounts for 90% by mass or more of all the solvents.

In addition, when the fluorenone-containing polymer layer is formed using a coating liquid containing water as a coating solvent, it can be confirmed by the following method: an fluorenone-containing polymer with respect to a polymer sheet for a solar cell module The total amount of the layer was less than 0.01% by mass.

In addition, the details of the polymer support and the polymer constituting the coating liquid for forming each polymer layer and other components are as described above in the description of the polymer sheet for a solar cell module of the present invention. It has been stated.

After coating each coating liquid for forming a polymer layer, a drying step of drying the coating film under a desired condition is provided. The drying temperature at the time of drying may be appropriately selected depending on the composition of the coating liquid, the amount of coating, and the like.

[Backplane for solar cell module]

The polymer sheet for a solar cell module of the present invention can be preferably used as a back sheet for a solar cell module.

The polymer sheet for a solar cell module of the present invention can be used as a front substrate and a back sheet in a solar cell having a laminated structure of "transparent front substrate/element structure portion/back sheet". The laminated structure of the "transparent front substrate/element structure portion/back plate" is a transparent substrate (front substrate such as a glass substrate) and components placed on the side where sunlight is incident. The structural part (including the solar cell element and the sealing material that seals it) and the solar cell back sheet are laminated. Here, from the element structure portion of the battery-side substrate, the back sheet is a back surface protective sheet disposed on the side of the position other than the front substrate.

In the present specification, a battery portion having a laminated structure of a "transparent front substrate/element structure portion" is referred to as a "battery side substrate", and the above-mentioned "transparent front substrate/element structure portion" is used. The battery portion of the laminated structure is formed by arranging an element structure portion on a transparent substrate disposed on the side where sunlight is incident.

In the polymer sheet for a solar cell module of the present invention, the polymer sheet for a solar cell module of the present invention is particularly excellent in terms of excellent durability of a fluoropolymer layer in a hot and humid environment such as heat or moisture. In the case of being used in a solar cell module as a back sheet for a solar cell module, it functions as the outermost layer in the external environment, that is, the outermost layer (back layer) on the back side.

[Solar battery module]

The solar cell module of the present invention is configured by providing the polymer sheet for a solar cell module of the present invention as described above as a back sheet for a solar cell module. In the solar cell module of the present invention, the solar cell module of the present invention exhibits excellent weather resistance and exhibits stable power generation performance for a long period of time.

Specifically, the solar cell module of the present invention includes a transparent support (a front support such as a glass substrate) through which sunlight is incident, a solar cell element provided on the support, and a solar cell element sealed thereon. The element structure portion of the sealing material and the back sheet for the solar cell module of the present invention as described above disposed on the side opposite to the position side of the substrate of the element structure portion (including the solar cell module of the present invention) A polymer sheet) has a laminated structure of "transparent front support/element structure portion/back plate". Specifically, it is configured such that an element structure portion in which a solar cell element that converts light energy of sunlight into electric energy is disposed, and is disposed on a transparent front support body disposed on a side where sunlight is directly incident In the solar cell module back sheet of the present invention, between the front support and the back sheet, an element structure including a solar cell element is used using a sealing material such as an ethylene-vinyl acetate (EVA) system. Part (eg solar cell unit) is sealed, then.

Fig. 3 schematically shows an example of the configuration of a solar battery module of the present invention. The solar cell module 10 is disposed between the transparent substrate 24 on which sunlight is incident and the polymer sheet 12 of the present invention described above, and is provided with a solar cell element 20 that converts light energy of sunlight into electric energy. The substrate and the polymer sheet 12 for a solar cell module are sealed by an ethylene-vinyl acetate-based sealing material 22. The polymer sheet for a solar cell module of the present embodiment is provided with a fluoropolymer layer 4 in contact with the fluorenone-containing polymer layer 3 on one surface side of the polymer support 16, and is provided on the other surface side (sunlight incident) The side layer 2 is provided with an undercoat layer 2 and a coloring layer 1 as a white layer as another layer.

For example, the solar cell module, the solar cell unit, and the components other than the backplane are described in detail in "Construction Materials for Solar Power Generation Systems" (Shomoto Shoichi, Industrial Research Association, 2008).

The transparent substrate has a light transmissive property that is transparent to sunlight. Yes, it can be suitably selected from the substrate that transmits light. In view of the power generation efficiency, the light transmittance is preferably as high as possible. For the substrate, for example, a transparent resin such as a glass substrate or an acrylic resin can be suitably used.

The above solar cell element can be applied: a single crystal germanium, a polycrystalline germanium, an amorphous germanium or the like, a copper-indium-gallium-selenium, a copper-indium-selenium, a cadmium-tellurium, a gallium-arsenic, etc. III-V or II-VI. Various known solar cell elements such as a compound semiconductor system.

Instance

The invention is more specifically illustrated by the following examples. The materials, the amounts used, the ratios, the processing contents, the processing order, and the like shown in the following examples can be appropriately changed as long as they do not deviate from the gist of the present invention. Therefore, the scope of the invention is not limited to the examples shown below. In addition, unless otherwise indicated, "part" is a quality standard.

[Manufacturing Example 1] <Production of Support>

(production of support 1)

- Synthesis of polyester -

The high-purity terephthalic acid was sequentially supplied to the esterification reaction tank having a temperature of 250 ° C and a pressure of 1.2 × 10 ⁵ Pa, which was previously added with about 123 kg of bis(hydroxyethyl) terephthalate. Mitsubishi Chemical Co., Ltd. produced 100 kg of a slurry of 45 kg of ethylene glycol (manufactured by Nippon Shokubai Chemical Co., Ltd.), and further esterification reaction was further carried out for 1 hour after the completion of the supply. Thereafter, 123 kg of the obtained esterification reaction product was transferred to a polycondensation reaction tank.

Then, in the polycondensation reaction tank which is transferred with the esterification reaction product, 0.3% by mass of ethylene glycol was added to the obtained polymer. After stirring for 5 minutes, an ethylene glycol solution of cobalt acetate and manganese acetate was added so as to be 30 ppm and 15 ppm, respectively, with respect to the obtained polymer. After further stirring for 5 minutes, a 2 mass% ethylene glycol solution of the alkoxytitanium compound was added so as to be 5 ppm with respect to the obtained polymer. After 5 minutes, a 10 mass% ethylene glycol solution of diethylphosphonium ethyl acetate was added in an amount of 5 ppm based on the obtained polymer. Thereafter, while stirring the oligomer at 30 rpm, the reaction system was gradually heated from 250 ° C to 285 ° C, and the pressure was lowered to 40 Pa. The time until the final temperature and the final pressure were reached was set to 60 minutes. The reaction system was flushed with nitrogen at a time when a predetermined stirring torque was reached, and returned to normal pressure to stop the polycondensation reaction. Then, it was sprayed in a strand shape into cold water, and cut directly to prepare a polymer pellet (having a diameter of about 3 mm and a length of about 7 mm). Furthermore, the time from the start of decompression to the time of reaching a predetermined stirring torque was 3 hours.

In the above-mentioned titanium alkoxide compound, the titanium alkoxide compound (Ti content = 4.44% by mass) synthesized in Example 1 of Paragraph No. [0083] of JP-A-2005-340616 is used.

- Matrix formation -

The agglomerates which were solid-phase polymerized as described above were melted at 280 ° C and cast onto a metal drum to prepare an unextended substrate having a thickness of about 2.5 mm. Thereafter, it was extended to 3 times in the longitudinal direction at 90 ° C, and further extended to 3.3 times in the transverse direction at 120 ° C. Further, heat treatment was performed at 195 ° C for 4 minutes. Thus, a biaxially oriented polyparaphenylene with a thickness of 250 μm is obtained. Ethylene formate support (support 1). The carboxyl group content of the support 1 was 28 eq/t.

Further, the carboxyl group content of each polymer support was determined by the following method.

- Determination of carboxyl content (AV value) -

A weight w [g] of about 0.1 g of each polymer support was measured, placed in a 5 mL round bottom flask to which benzyl alcohol was added, and kept in a stoppered state at a temperature of 205 ° C for 24 hours. . Thereafter, the contents were added to 15 mL of chloroform. A small amount of a phenol red indicator was added to the solution, and it was titrated with a benzyl alcohol solution having a concentration of 0.01 N/L of potassium hydroxide. The amount of the potassium hydroxide solution required for the titration was set to ymL, and the amount of carboxyl groups (COOH-based amount) of the biaxially stretched PET was determined by the following formula.

Carboxyl content (equivalent/t) = 0.01 × y / w

[Manufacturing Example 2]

(production of support 2)

The agglomerates of the polymer obtained in the production of the support 1 were subjected to the following solid phase polymerization treatment. Thereafter, the substrate is formed by the same method as in the case of the support 1, and the support 2 is obtained.

The obtained support 2 had a carboxyl group content of 14 eq/t.

- Solid phase polymerization treatment -

The obtained pellet was held in a vacuum vessel maintained at 40 Pa at a temperature of 220 ° C for 30 hours to carry out solid phase polymerization.

[Manufacturing Example 3]

<Production of Support 3>

-Preparation of masterbatch containing titanium dioxide -

30 Kg of the solid phase polymerized agglomerate obtained in Production Example 2 of the support was dried in advance at 120 ° C for 10 hours in an environment of 10 -3 torr.

30 gram of rutile-type titanium dioxide having an average particle diameter of 0.3 μm (electron microscopy) was mixed and supplied to a belt type twin-screw extruder, and kneaded and extruded at 275 ° C while being degassed. A masterbatch mass (MB-I) containing 50% by mass of titanium oxide (having a diameter of about 3 mm and a length of about 7 mm). The masterbatch mass had a carboxyl group content of 15 eq/t. Further, the average particle diameter of titanium dioxide was measured by the following method.

The titanium dioxide fine particles were observed by a scanning electron microscope (SEM), and the magnification was appropriately changed according to the size of the particles, and a photograph was taken to enlarge and copy the photograph taken. Then, the long diameter and the short diameter of each particle are measured for at least 100 randomly selected microparticles. The average of the long diameter and the short diameter is taken as the particle diameter of the particle. The particle diameter of each particle was determined, and the average value of 100 particles was made into the average particle diameter of the titanium oxide.

- Matrix formation -

A mixed agglomerate obtained by mixing 80% by mass of the solid phase polymerized particles obtained in Production Example 2 of the support and 20% by mass of the master batch particles MB-I prepared in advance, and the support body In Production Example 1, a biaxially-oriented polyethylene terephthalate support (support 3) having a thickness of 250 μm was obtained in the same manner. The carboxyl group content of the support 3 was 15 eq/t.

[Manufacturing Example 4]

<Production of Support 4>

- Matrix formation -

The A layer, the B layer, and the C layer in which the solid phase polymerized agglomerate obtained in Production Example 2 of the support and the masterbatch mass MB-I were mixed in the following ratio were co-extruded, and In the same substrate formation method as in Production Example 1 of the support, a biaxially-oriented polyethylene terephthalate support (support 4) having a thickness of 250 μm including the A layer, the B layer, and the C layer was obtained. The thicknesses of the A layer, the B layer, and the C layer are respectively about 50 μm, about 150 μm, and about 50 μm. Further, the carboxyl group content of the support 4 was 16 eq/t.

In the layer B, a mixed agglomerate of 64% by mass of the solid phase polymerized aggregate obtained in Production Example 2 of the support and 36% by mass of the masterbatch agglomerate MB-I prepared in advance, A layer was used. The solid phase polymerized agglomerate obtained in Production Example 2 in which the support was used alone with the C layer.

[Manufacturing Example 5]

<Production of Support 5>

-Preparation of masterbatch containing end-capping agent -

9 Kg of the solid phase-polymerized agglomerate obtained in Production Example 2 of the support was dried in an environment of 120 ° C and 10 ^-3 torr for 8 hours in advance.

1 kg of the following blocking agent A was added thereto, and a masterbatch mass (MB-II) containing 10% by mass of the blocking agent A was prepared by the same method as MB-I (having a diameter of about 3 mm and a length of about 7 mm). ).

. Blocking agent A: carbodiimide series: N, N'-dicyclohexylcarbodiimide, Mw=206

- Matrix formation -

A mixed agglomerate obtained by mixing 96% by mass of the solid phase polymerized mass obtained in Production Example 2 of the support with the master batch MB-II 4% by mass prepared in advance, and other support In Production Example 1 of the body, a biaxially-oriented polyethylene terephthalate support (support 5) having a thickness of 250 μm was obtained in the same manner. The carboxyl group content of the support 5 was 8 eq/t.

[Manufacturing Example 6]

<Production of Support 6>

-Preparation of masterbatch containing end-capping agent -

MB-III was produced in the same manner as in Production Example 5 except that the above-mentioned blocking agent B was used instead of the blocking agent A.

. The terminal blocking agent B: a cyclic carbodiimide compound: the cyclic carbodiimide compound (2) described in JP-A-2011-153209, and [0175], Mw=516

- Matrix formation -

A mixed agglomerate obtained by mixing 92% by mass of the solid phase polymerized mass obtained in Production Example 2 of the support and 8 % by mass of the master batch agglomerate MB-III prepared in advance, and other support In Production Example 1 of the body, a biaxially-oriented polyethylene terephthalate support (support 6) having a thickness of 250 μm was obtained in the same manner. The carboxyl group content of the support 6 was 8 eq/t.

[Evaluation]

The evaluation method used in the present invention is described below.

(subsequent evaluation)

The sample was conditioned at 25 ° C and a relative humidity of 60% for 24 hours. Thereafter, each of the six flaws was scored on the surface of the sample on which the polymer layer 2 was formed by using a doctor blade at intervals of 3 mm. A Mylar tape having a width of 20 mm was adhered thereto and peeled off rapidly in the direction of 180 degrees.

The classification is performed according to the number of meshes peeled off as follows.

5: No peeling at all

4: The stripped mesh is 0 (zero), but the scar is slightly peeled off.

3: The stripped mesh is less than 1 grid

2: The stripped mesh is 1 or more and less than 5

1: The stripped mesh is 5 or more

Practically allowed are those classified to grades 3 to 5.

The subsequent evaluation was carried out on a sample before and after 80 hours at 120 ° C and a relative humidity of 100%. In addition, in the following Table 1, the evaluation result of the sample before the damp heat transit time is referred to as "fresh", and the evaluation result of the sample after the damp heat elapsed time is referred to as "after the wet heat elapsed time 1" .

In addition, the result of the evaluation of the sample before and after the time of 100 hours under conditions of 120 ° C and a relative humidity of 100% was referred to as "after wet heat and time 2".

(Amount of residual solvent of the fluorine-containing polymer layer)

The assay was carried out using the method described above.

(Evaluation of light resistance)

First, the YI value (YI-1) of the sample was measured using a spectrophotometer "Spectro Color Meter SE2000" manufactured by Nippon Denshoku Industries Co., Ltd.

Thereafter, the light resistance tester "EYE Super UV Tester W-151" manufactured by Iwasaki Electric Co., Ltd. was used to irradiate ultraviolet light for 48 hours at an illuminance of 900 W/m ² . Among them, the environmental conditions at the time of ultraviolet light irradiation were 63 ° C and a relative humidity of 50%.

Then, the YI value (YI-2) of the sample was measured again using a spectrophotometer "Spectro Color Meter SE2000" manufactured by Nippon Denshoku Industries Co., Ltd.

YI=(YI-2)-(YI-1) was taken as the degree of coloration of the sample.

The obtained values were ranked according to the following evaluation criteria. Among them, grades 3 to 5 are practically permissible ranges.

<Evaluation criteria>

5: The value of YI is less than 1.

4: The value of YI is 1 or more and less than 3.

3: The value of YI is 3 or more and less than 5.

2: The value of YI is 5 or more and less than 10.

1: The value of YI is 10 or more.

[Example-1] <Formation of Polymer Layer 1 as an Anthracene-Based Polymer Layer>

- Preparation of titanium dioxide dispersion -

Each component in the following composition was mixed, and the mixture was subjected to a dispersion treatment for 1 hour by a Dyno-mill type disperser.

(composition of pigment dispersion)

- Preparation of coating liquid for forming polymer layer 1 -

Each component in the following composition was mixed to prepare a coating liquid for forming a polymer layer 1.

(Composition of coating liquid for forming polymer layer 1)

- Coating of coating liquid for forming polymer layer 1 -

One side of the support 1 produced in Production Example 1 was subjected to corona treatment under the following conditions. Then, the coating liquid for forming the polymer layer 1 was applied to the corona-treated surface of the support 1 produced in the production example 1 so that the amount of the binder applied was 1.2 g/m ² , and dried at 180 ° C. One minute, a polymer layer 1 (an oxime-containing polymer layer) having a dry thickness of about 1.3 μm was formed.

(corona treatment conditions)

. Device: 6KVA model of solid corona processor manufactured by Pillar

. Electrode and dielectric gap clearance (gap clearance): 1.6mm

. Processing frequency: 9.6kHz

. Processing speed: 20m/min

. Processing intensity: 0.375kV. A. Min/m ²

<Formation of Polymer Layer 2 as Fluorinated Polymer Layer>

- Preparation of coating liquid for forming polymer layer 2 -

Each component in the following composition was mixed to prepare a polymer layer 2-shaped coating liquid.

(Composition of coating liquid for forming polymer layer 2)

The mixture of these components was dispersed by a dissolver at a rotation speed of 4000 rpm for 5 minutes to prepare a coating liquid for forming a polymer layer 2.

- Coating of coating liquid for forming polymer layer 2 -

The coating layer for forming a polymer layer 2 was applied to the polymer layer 1 formed as described above so that the amount of the binder applied was 5.0 g/m ² , and dried at 120 ° C for 3 minutes to form a dry thickness. It is a polymer layer 2 of about 5.8 μm.

The film obtained by sequentially laminating a polymer support, a polymer layer 1 (an oxime-containing polymer layer), and a polymer layer 2 (a fluorine-containing polymer layer) as the example-1 was obtained. Polymer sheet for battery module.

<evaluation>

The obtained polymer sheet sample for a solar cell module of Example-1 was evaluated for the scratch resistance, the residual solvent amount of the polymer layer 2, and the adhesion. The results obtained are shown in Table 1 below.

[Example-2, Comparative Example-1, Comparative Example-2]

A polymer sheet for a solar cell module of Example-2, Comparative Example-1, and Comparative Example-2 was produced in the same manner as in Example-1, except that the binder of the polymer layer 1 was changed as in the following Table 1.

The polymer sheet samples for solar cell modules of the respective examples and comparative examples obtained were subjected to the same evaluation as in Example-1. The results obtained are shown in Table 1 below.

[Comparative Example-3]

A polymer sheet for a solar cell module of Comparative Example-3 was produced in the same manner as in Example-1 except that the polymer layer 1 was not provided.

The obtained polymer sheet sample for solar cell module of Comparative Example 3 was subjected to the same evaluation as in Example-1. The results obtained are shown in Table 1 below.

[Example-4, Example-5, Comparative Example-4, Comparative Example-5, Comparative Example-6]

Example-4 and Example-5 were produced in the same manner as in Example-1, Example-2, Comparative Example-1, Comparative Example-2, and Comparative Example-3, except that the binder of the polymer layer 2 was changed as shown in Table 1 below. Polymer sheets for solar cell modules of Comparative Example-4, Comparative Example-5, and Comparative Example-6.

The polymer sheet samples for solar cell modules of the respective examples and comparative examples obtained were subjected to the same evaluation as in Example-1. The results obtained are shown in Table 1 below.

[Example-6, Example-7]

Polymer sheets for solar cell modules of Examples -6 and -7 were produced in the same manner as in Example-1 and Example 2, except that the support was changed to the support 2.

The polymer sheet samples for solar cell modules of the respective examples and comparative examples obtained were subjected to the same evaluation as in Example-1. The results obtained are shown in Table 1 below.

[Example-8, Example-9]

Polymer sheets for solar cell modules of Examples -8 and -9 were produced in the same manner as in Examples -6 and -7 except that the binder of the polymer layer 2 was changed as shown in the following Table 1.

The same evaluation as in Example-1 was carried out on the obtained polymer sheet samples for solar cell modules of the respective examples. The results obtained are shown in Table 1 below.

[Example-10~Example-17]

A polymer sheet for a solar cell module of Example-10 to Example-17 was produced in the same manner as in Example-7 except that the type and amount of the crosslinking agent of the polymer layer 1 were changed as shown in Table 1 below.

The same evaluation as in Example-1 was carried out on the obtained polymer sheet samples for solar cell modules of the respective examples. The results obtained are shown in Table 1 below.

[Example-18~Example-22]

A polymer sheet for a solar cell module of Examples -18 to 22 was produced in the same manner as in Example -7 except that the amount of the crosslinking agent of the polymer layer 2 was changed as in the following Table 1.

The same evaluation as in Example-1 was carried out on the obtained polymer sheet samples for solar cell modules of the respective examples. The results obtained are shown in Table 1 below.

[Example-23~Example-28]

Polymer sheets for solar cell modules of Examples -23 to 28 were produced in the same manner as in Example-7 except that the types and the amounts of the ultraviolet absorbers of the polymer layer 1 and the polymer layer 2 were changed as shown in the following Table 1. .

The same evaluation as in Example-1 was carried out on the obtained polymer sheet samples for solar cell modules of the respective examples. The results obtained are shown in Table 1 below.

[Example -29~Example-32]

A polymer sheet for a solar cell module of Example -29 to Example-32 was produced in the same manner as in Example-1 except that the support was changed as shown in Table 1 below.

The same evaluation as in Example-1 was carried out on the obtained polymer sheet samples for solar cell modules of the respective examples. The results obtained are shown in Table 1 below.

[Comparative Example-7]

A polymer sheet for a solar cell module of Comparative Example-7 was produced in the same manner as in Example-1 except that the binder of the polymer layer 1 was changed as shown in Table 1 below.

The obtained polymer sheet sample for a solar cell module of Comparative Example-7 was subjected to the same evaluation as in Example-1. The results obtained are shown in Table 1 below.

The binder, the crosslinking agent, and the ultraviolet absorber used in each of the examples and comparative examples described in Table 1 are as follows.

-Adhesive of polymer layer 1 -

. P-1: Ceranate WSA1070 (an oxime-based adhesive (an ketone/acrylic composite adhesive) manufactured by DIC, with a solid content of 38%)

. P-2: Ceranate WSA1060 (DIC) ketone-based adhesive (anthrone/acrylic composite adhesive, solid content 38%)

. P-3: Vylonal MD-1100 (polyester adhesive made by Toyobo Co., Ltd., solid content 30%)

. P-4: Olester UD350 (a urethane adhesive manufactured by Mitsui Chemicals Co., Ltd., 38% solids)

. P-5: Chemipearl M-200 (polyolefin adhesive manufactured by Mitsui Chemicals Co., Ltd., 40% solid content)

-Adhesive of polymer layer 2 -

. P-A: Lumiflon LF200 (Fluorine adhesive manufactured by Asahi Glass Co., Ltd., solid content 60%)

. P-B: Zeffle GK-570 (a fluoroadhesive made by Daikin (shares) with a solid content of 65%)

-crosslinker -

. H-1: Epocros WS700 (oxazoline crosslinker manufactured by Nippon Shokubai Co., Ltd., solid content 25%)

. H-2: Carbodilite V-02-L2 (Japan Textiles Co., Ltd.) Manufactured carbodiimide cross-linking agent with a solid content of 40%)

. H-3: Sumidule N3300 (isocyanate crosslinker manufactured by Bayer, 100% solids)

-UV absorber -

. Titanium dioxide: Tipaauqe CR93 (manufactured by Ishihara Sangyo Co., Ltd., volume average particle diameter is 0.28 μm, solid content is 100% by mass)

. UV absorber A: Triazine-based UV absorber of the following structure

As is apparent from the above Table 1, the polymer sheet for a solar cell module having each example of the polymer layer 1 having an anthrone-based polymer as a binder has a fluorine-based polymer as a binder even after a damp heat. The adhesion of the polymer layer 2 was also good.

On the other hand, the polymer sheets for solar cell modules of Comparative Example 1 and Comparative Example 4 in which the binder of the polymer layer 1 is a polyester-based adhesive, and the adhesion of the polymer layer 2 after the moist heat and the passage of time deterioration. Further, the polymer sheets for solar cell modules of Comparative Example 2 and Comparative Example 5 in which the binder of the polymer layer 1 was a polyurethane adhesive, and the polymerization after the wet heat and the passage of time were obtained. The adhesion of the layer 2 deteriorates. In addition, the polymer sheets for solar cell modules of Comparative Example 3 and Comparative Example 6 in which the fluorine-based polymer layer 2 was directly applied to the PET-based support without providing the polymer layer 1 were observed. The adhesion of the polymer layer 2 deteriorates.

Further, in the polymer sheet for a solar cell module of each example, in a more preferable aspect in which the polymer layer contains the ultraviolet absorber, the light resistance is also better.

Further, the polymer sheet for a solar cell module in which the polymer layer-based coating liquid is used to form the polymer layer 2 containing the fluorine-based polymer has the following advantages: good weather resistance, and short drying step in the production process .

[Example-33~Instance-64]

The undercoat layer and the white layer were formed by the following methods on the opposite faces of the polymer sheet 1 and the polymer layer 2 of the polymer sheet for a solar cell module of Example-1 to Example-32, respectively.

<Formation of undercoat layer>

- Preparation of coating liquid for forming an undercoat layer -

The following components were mixed to prepare a coating liquid for forming an undercoat layer.

(Composition of coating liquid for forming an undercoat layer)

- Coating of coating liquid for forming an undercoat layer -

The opposite side of the surface of the polymer sheet for the solar cell module of Example-1 to Example-32 on which the polymer layer 1 and the polymer layer 2 were provided was subjected to corona treatment under the following conditions.

. Electrode and dielectric roller gap: 1.6mm

. Processing frequency: 9.6kHz

. Processing speed: 20m/min

. Processing intensity: 0.375kV. A. Min/m ²

The coating liquid for forming an undercoat layer was applied to the surface of the support on which the corona treatment was applied so that the amount of the adhesive applied was 0.12 g/m ² , and dried at 180 ° C for 2 minutes to form an undercoat layer. .

<Formation of white layer>

- Preparation of coating liquid for white layer formation -

The following components were mixed to prepare a coating liquid for forming a white layer.

(Composition of coating liquid for forming a white layer)

- Coating of coating liquid for white layer formation -

The coating liquid for forming a white layer was applied to the undercoat layer formed as described above at a coating amount of 4.7 g/m ² and a coating amount of titanium dioxide of 5.6 g/m ² , and dried at 170 ° C. A white layer was formed in 2 minutes.

As described above, the polymer layer 1 and the polymer layer 2 are obtained by the polymerization of the solar cell module of the example -33 to the example -32, respectively, and the primer layer and the white layer are common. Sample of the piece.

-Production of solar cell modules -

Using the polymer sheets for the solar cell modules of Examples-33 to Instance-64, the solar cell modules of Example-33 to Example-64 were fabricated by the following method.

A tempered glass having a thickness of 3 mm, an EVA sheet (SC50B manufactured by Mitsui Chemicals Fabro Co., Ltd.), a crystallization solar cell unit, an EVA sheet (SC50B manufactured by Mitsui Chemicals Fabro Co., Ltd.), and an example of a back sheet are used. The polymer of the solar cell module of Example-64 was sequentially superposed, and hot pressed using a vacuum laminator (manufactured by Nisshinbo Co., Ltd., vacuum laminator), followed by EVA. At this time, the white layer of the polymer sheet for a solar cell module is placed in contact with the EVA sheet. In addition, the following method is as follows.

Thus, the crystal solar cell module 33 to the solar cell module 64 using the back sheet 33 to the back sheet 64 are produced.

(follow the method)

After vacuum suction at 128 ° C for 3 minutes using a vacuum laminator, the mixture was pressurized for 2 minutes and temporarily stopped. Thereafter, it was subjected to formal completion treatment at 150 ° C for 30 minutes in a drying oven.

Thus, a polymer sheet for a solar cell module using Examples-33 to Instance-64 was used as a solar cell module of the crystal system of the example -33 to Example-64 of the back sheet.

The solar cell modules of the produced example-33 to the example-64 were subjected to power generation operation, and as a result, they exhibited good power generation performance as solar cells.

1‧‧‧Colored layer

2‧‧‧Undercoat

3‧‧‧Anthrone-containing polymer layer

4‧‧‧Fluorine-based polymer layer (fluoropolymer layer containing organic solvent)

10‧‧‧Solar battery module

12‧‧‧Polymer film for solar cell module (backplane for solar cell module)

16‧‧‧Support

20‧‧‧Solar battery components

22‧‧‧ Sealing material

24‧‧‧Transparent front substrate

FIG. 1 is a schematic view showing an example of a cross section of a polymer film for a solar cell module of the present invention.

2 is a schematic view showing another example of a cross section of a polymer film for a solar cell module of the present invention.

3 is a schematic view showing an example of a cross section of a solar battery module using a polymer film for a solar cell module of the present invention as a back sheet.

3‧‧‧Anthrone-containing polymer layer

4‧‧‧Fluorine-based polymer layer (fluoropolymer layer containing organic solvent)

12‧‧‧Polymer film for solar cell module (backplane for solar cell module)

16‧‧‧Support

Claims (19)

A polymer sheet for a solar cell module, comprising: a polymer support; an anthranone-based polymer layer disposed on at least one side of the polymer support and containing an anthrone-based polymerization And a fluorine-containing polymer layer disposed on the fluorenone-containing polymer layer and containing a fluorine-based polymer as a binder; and the fluorine-containing polymer layer is opposite to the fluorine-containing polymer layer More than 0.01% by mass or more of the organic solvent is contained in all the binders in the polymer layer. The polymer sheet for a solar cell module according to claim 1, wherein the fluorine-containing polymer layer is formed by coating a coating liquid containing an organic solvent as a coating solvent, and The coating film described above is dried to form. The polymer sheet for a solar cell module according to claim 1 or 2, wherein the polymer support is a polyester support. The polymer sheet for a solar cell module according to the above aspect, wherein at least one of the fluorenone-containing polymer layer and the fluorine-containing polymer layer contains an ultraviolet absorber. The polymer sheet for a solar cell module according to claim 1 or 2, wherein at least one of the fluorenone-containing polymer layer and the fluorine-containing polymer layer is opposite to each polymer layer All of the binders contain 3% by mass to 30% by mass of a component derived from a crosslinking agent. Such as the solar cell module described in claim 1 or 2 The polymer sheet for use in which the component derived from the crosslinking agent containing the fluorenone-based polymer layer is derived from at least one selected from the group consisting of an oxazoline crosslinking agent and a carbodiimide crosslinking agent. The component of the crosslinking agent, and the component derived from the crosslinking agent of the fluorine-containing polymer layer is a component derived from an isocyanate crosslinking agent. The polymer sheet of claim 3, wherein the polymer support contains inorganic fine particles. The polymer sheet according to claim 7, wherein the polymer support comprises two or more layers having different contents of the inorganic fine particles. The polymer sheet of claim 3, wherein the polymer support is a polyester support containing a blocking agent. The polymer sheet of claim 9, wherein the capping agent is a carbodiimide-based capping agent. A method for producing a polymer sheet for a solar cell module, comprising the steps of: coating an anthranone-based polymer layer containing an anthrone-based polymer as a binder on at least one surface of a polymer support; a coating liquid is formed to form a coating film, and the coating film is dried to form an oxime-containing polymer layer; and the fluorene-based polymer layer is coated with a fluorine-based polymer as a binder and contains The organic solvent is used as a coating liquid for forming a fluorine-containing polymer layer as a coating solvent to form a coating film, and the coating film is dried. The method for producing a polymer sheet for a solar cell module according to claim 11, wherein the fluorenone-containing polymer layer is formed by coating The cloth liquid contains water as a coating solvent. The method for producing a polymer sheet for a solar cell module according to the invention of claim 11, wherein the polymer support is a polyester support. The method for producing a polymer sheet for a solar cell module according to the above aspect, wherein the coating liquid for forming an anthrone-containing polymer layer and the fluorine-containing polymer layer are formed. An ultraviolet absorber is added to at least one of the coating liquids. The method for producing a polymer sheet for a solar cell module according to the above aspect, wherein the coating liquid for forming an anthrone-containing polymer layer and the fluorine-containing polymer layer are formed. In at least one of the coating liquids, a crosslinking agent is added in an amount of 3 to 30% by mass based on all the binders in the coating liquid for forming each polymer layer. The method for producing a polymer sheet for a solar cell module according to claim 15, wherein the coating liquid for forming an anthrone-containing polymer layer is added to an oxazoline-based crosslinking agent. And at least one crosslinking agent in the carbodiimide crosslinking agent, and an isocyanate crosslinking agent is added to the coating liquid for forming a fluorine-containing polymer layer. A polymer sheet for a solar cell module, characterized in that it is a polymer sheet for a solar cell module according to claim 1; and the solar cell according to claim 11 The module is manufactured by a method of producing a polymer sheet. A back panel for a solar cell module, characterized by having a Please refer to the polymer sheet for solar cell module described in Item 17 of the patent. A solar cell module comprising the back sheet for a solar cell module according to claim 18 of the patent application.