JP6084020B2 - Weather-resistant resin layer, laminate and solar cell module - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a weather resistant resin layer and a laminate, and more particularly to a weather resistant resin layer and a laminate suitably used for a solar cell back surface protective sheet, and a solar cell module using the same.

  Conventionally, outdoor use products such as solar cells such as back protection sheets for solar cells, road noise barrier exteriors, general building materials (roofs / walls), signboards, agricultural greenhouses, etc. have a weather-resistant resin layer showing weather resistance. There is a need for a laminate. As such a weather resistant resin layer, a fluororesin film such as PVF, PVDF or ETFE is used. These fluororesin films exhibit excellent weather resistance, chemical resistance, and contamination resistance.

  However, since the fluororesin film contains a halogen substance, there is a problem in that harmful substances are generated from waste when it is processed by incineration or the like. Moreover, the fluororesin film has high moisture permeability. For this reason, when a fluororesin film is used as an outer layer and another resin film such as a polyethylene terephthalate (PET) film is used as an inner layer, there is a problem that the resin film is likely to be degraded such as hydrolysis.

  As a laminate having a weather-resistant resin layer that solves these problems, a laminate having a weather-resistant PET film is disclosed (for example, see Patent Documents 1 and 2).

  However, the laminates disclosed in Patent Documents 1 and 2 have a problem that the weather-resistant PET film undergoes discoloration and decreases in strength when exposed to ultraviolet rays. In particular, when used in a back protection sheet for solar cells, the weather-resistant PET film becomes brittle when discoloration occurs due to ultraviolet rays, and moisture in the outside air easily penetrates or cracks are generated in the brittle portions. There exists a problem that the insulation of a back surface protection sheet falls.

JP 2009-188072 A JP 2000-114565 A

  The present invention provides a weather-resistant resin layer that is excellent in weather resistance and water resistance, and that suppresses the generation of harmful substances from waste generated when discarded, and a laminate using the same.

  As a result of intensive studies to achieve the above object, the present inventors have found that the above object can be achieved by configuring the weather resistant resin layer to contain a specific acrylic polyol resin, thereby completing the present invention. It came to do.

That is, the present invention relates to the following weather resistant resin layer, laminate and solar cell module.
1. A weatherable resin layer comprising an acrylic polyol resin containing (meth) acrylic acid hydroxy ester and a copolymer of (meth) acrylic acid hydroxy ester.
2. Content of the said acrylic polyol resin is a weather resistant resin layer of said claim | item 1 which is 5-40 mass% with respect to 100 mass% of said weather resistant resin layers.
3. Item 3. The weather resistant resin layer according to Item 1 or 2, which contains 10 to 60% by mass of titanium oxide.
4). Item 4. The weather resistant resin layer according to any one of Items 1 to 3, containing 0.5 to 6.0% by mass of an epoxy resin.
5. Item 5. The weather resistant resin layer according to any one of Items 1 to 4, comprising 0.5 to 6.0% by mass of a polycarbonate resin.
6). Item 6. The weather resistant resin layer according to any one of Items 1 to 5, comprising a non-yellowing polyisocyanate.
7). A laminate having the weatherable resin layer according to any one of Items 1 to 6 laminated on at least one surface of a resin film.
8). Item 8. The laminate according to Item 7, wherein the resin film contains polyethylene terephthalate.
9. Item 9. The laminate according to Item 7 or 8, which is a solar cell back surface protective sheet.
10. The solar cell module obtained using the laminated body in any one of said item 7-9.

  The weather resistant resin layer of the present invention is excellent in weather resistance and water resistance by containing an acrylic polyol resin containing (meth) acrylic acid hydroxy ester and a copolymer of (meth) acrylic acid hydroxy ester. Yes. In addition, since halogen substances such as fluorine are not substantially contained, generation of harmful substances from waste generated when discarded by incineration or the like is suppressed.

  By laminating the weather resistant resin layer of the present invention on a resin film to obtain a laminate, a laminate excellent in weather resistance and water resistance can be obtained. A solar cell module excellent in weather resistance and water resistance can be obtained by forming a solar cell module using the laminate using the weather resistant resin layer of the present invention as a solar cell back surface protective sheet.

It is sectional drawing which shows one Embodiment of the laminated body using the weather resistant resin layer of this invention. It is sectional drawing which shows one Embodiment of the solar cell module of this invention.

  The weather resistant resin layer of the present invention is characterized by containing an acrylic polyol resin containing (meth) acrylic acid hydroxy ester and a copolymer of (meth) acrylic acid hydroxy ester.

  The weather-resistant resin layer of the present invention having the above characteristics is excellent in weather resistance and water resistance by including (meth) acrylic acid hydroxy ester and (meth) acrylic acid hydroxy ester copolymer. ing. In addition, since halogen substances such as fluorine are not substantially contained, generation of harmful substances when discarded by incineration or the like is suppressed. Moreover, since the said weather resistant resin layer is laminated | stacked on the at least one surface of the resin film, the laminated body of this invention is excellent in a weather resistance and water resistance. Furthermore, the solar cell module excellent in weather resistance and water resistance can be obtained by using the said laminated body for a solar cell module.

  In addition, in this specification, (meth) acrylic acid hydroxyester is used by the meaning containing acrylic acid hydroxyester, methacrylic acid hydroxyester, or both. In the present specification, the phrase “substantially not containing a halogen substance” means that the halogen substance is not positively added to the main agent and the curing agent that form the weather resistant resin layer. Therefore, this does not exclude the case where the weather resistant resin layer contains a halogen substance as an inevitable impurity.

(Acrylic polyol resin)
The weather resistant resin layer of the present invention contains an acrylic polyol resin. 5-40 mass% is preferable with respect to 100 mass% of weather resistant resin layers, and, as for content of the acrylic polyol in a weather resistant resin layer, 10-20 mass% is more preferable. If the content of the acrylic polyol resin is too small, the flexibility of the weather-resistant resin layer is lowered, and when laminated with a resin film or the like, peeling may occur over time. Moreover, when there is too much content of acrylic polyol resin, when a PET film is laminated | stacked as a resin film, there exists a possibility of producing blocking between a weather resistant resin layer and a resin film.

  The acrylic polyol resin includes (meth) acrylic acid hydroxy ester and a copolymer of (meth) acrylic acid hydroxy ester.

  Although it does not specifically limit as (meth) acrylic acid hydroxyester, For example, hydroxymethyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxypentyl (meth) acrylate , Hydroxyhexyl (meth) acrylate, hydroxyheptyl (meth) acrylate, hydroxyoctyl (meth) acrylate, hydroxynonyl (meth) acrylate, hydroxydecyl (meth) acrylate, hydroxyundecyl (meth) acrylate, hydroxydodecyl (meth) acrylate Etc.

  Although it does not specifically limit as a copolymer of (meth) acrylic-acid hydroxyester, For example, what copolymerized the compound enumerated as said (meth) acrylic-acid hydroxyester can be used. Examples of the state of copolymerization include random copolymerization, block copolymerization, and graft copolymerization (graft modification).

  The weather resistant resin layer of the present invention may contain other components in addition to the acrylic polyol resin. As said other component, an epoxy resin, polycarbonate resin, a titanium oxide etc. are mentioned, for example.

  The epoxy resin is not particularly limited. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, alkylphenol monoglycidyl ether, tetrabromobisphenol A type epoxy resin, cresol novolac type epoxy resin, phenol novolac type epoxy resin, Modified novolac type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene skeleton modified polyfunctional type epoxy resin, alkyldiphenol type epoxy resin, polyetherester type epoxy resin, phenoxy resin, modified phenoxy resin, etc. It is done.

  It is preferable that content of an epoxy resin is 0.5-6.0 mass% with respect to 100 mass% of weather resistant resin layers. When there is too little content of an epoxy resin, a weather-resistant resin layer will deteriorate by wet heat test, adhesiveness may arise, and there exists a possibility that a weather resistance may fall. When there is too much content of an epoxy resin, there exists a possibility that the adhesiveness of a weather resistant resin layer and a resin film may fall, and there exists a possibility that it cannot coat uniformly on a resin film.

  Although it does not specifically limit as said polycarbonate resin, For example, polycarbonate diol etc. are mentioned.

  The content of the polycarbonate resin is preferably 0.5 to 6.0% by mass with respect to 100% by mass of the weather resistant resin layer. When there is too little content of polycarbonate resin, a weather-resistant resin layer will deteriorate by wet heat test, adhesiveness may arise, and there exists a possibility that a weather resistance may fall. When there is too much content of an epoxy resin, there exists a possibility that the adhesiveness of a weather resistant resin layer and a resin film may fall, and there exists a possibility that it cannot coat uniformly on a resin film.

  By adding the titanium oxide to the weather resistant resin layer, durability to ultraviolet rays can be imparted to the weather resistant resin layer. It is preferable that content of a titanium oxide is 10-60 mass% with respect to 100 mass% of weather resistant resin layers. If the content of titanium oxide is too small, ultraviolet rays may pass through the weather-resistant resin layer and the PET resin that is a resin film may be deteriorated. When there is too much content of titanium oxide, there exists a possibility that the adhesiveness of a weather resistant resin layer and a resin film may fall.

  The weather-resistant resin layer of the present invention can be formed by applying a base material in which the above acrylic polyol resin and other components are dissolved in a solvent. Although it does not specifically limit as a solvent, For example, ethyl acetate, methyl ethyl ketone, toluene, etc. are mentioned.

  The weather resistant resin layer of the present invention may be used as a urethane resin by mixing a curing agent with the above main agent. As the curing agent, a polyisocyanate compound can be used, and it is particularly preferable to use a non-yellowing polyisocyanate such as hexamethylene diisocyanate.

  The blending ratio of the main agent and the curing agent in the urethane resin is preferably 2 to 10 parts by weight, and more preferably 3 to 4 parts by weight based on 100 parts by weight of the main agent. If the proportion of the curing agent is too small, the urethane resin may be insufficiently cured and the weather resistance may not be sufficiently exhibited. When the ratio of the curing agent is too large, foaming occurs due to curing aging, which may reduce productivity.

  The weather resistant resin layer of the present invention can be formed into a laminate by laminating on at least one surface of the resin film. Such a laminate is also one aspect of the present invention. In FIG. 1, one Embodiment of the laminated body of this invention is shown. In FIG. 1, a laminate 10 has a weather resistant resin layer 11 laminated on a resin film 12.

  Although it does not specifically limit as resin which forms a resin film, It is preferable to use resin which does not contain a halogen substance substantially. An example of such a resin is a resin containing polyethylene terephthalate. By forming a resin containing polyethylene terephthalate as an inner layer and laminating the above weather-resistant resin layer on the outer layer, it is possible to block ultraviolet rays from the outside and protect the resin film of the inner layer from ultraviolet rays. . Moreover, since the said laminated body does not contain halogen substances, such as a fluorine, generation | occurrence | production of a harmful substance from the waste produced when it discards by incineration etc. is suppressed. Furthermore, the laminate is excellent in water resistance, and the PCT test (pressure cooker test: test conditions 120 ° C., humidity 100%, 0.2 Mpa) is performed for 50 hours, and the initial elongation at break is 100%. When the retention ratio is calculated, a high elongation at break is indicated.

  The laminate of the present invention can be formed by applying a urethane resin composition in which the above main agent or the main agent and a curing agent are mixed on at least one surface of the resin film.

  The coating method is not particularly limited as long as a uniform coating film can be formed. For example, gravure coating, reverse coating, comma coating, kiss coating, knife coating, curtain coating, extrusion coating, dip coating, spray coating Etc.

  When using the laminate of the present invention as a solar cell back surface protective sheet, the surface of the laminate to be bonded to the solar cell encapsulant is for the purpose of improving the adhesion between the laminate and the solar cell encapsulant, Further, an easy adhesion layer may be provided. The easy-adhesion layer may be formed by being applied to the laminate as a coating agent, or may be formed by being laminated as a film.

  The resin for forming the easy-adhesion layer is not particularly limited as long as the adhesion between the laminate and the solar cell encapsulant can be expressed. For example, ionomer, ethylene-vinyl acetate copolymer (EVA), polyethylene resin, and the like can be used. Can be mentioned.

  In order to impart gas barrier properties and water vapor barrier properties to the laminate, a gas barrier layer may be laminated on the weather resistant resin layer. The gas barrier layer may be laminated on the weather-resistant resin layer, or a plurality of layers may be laminated. As an example of the layer structure of the laminate in which the gas barrier layer is laminated, the gas barrier layer / the weather resistant resin layer / the resin film or the gas barrier layer / the gas barrier layer / the weather resistant resin layer / the resin film are sequentially arranged from the top. A layer structure is mentioned.

  The material for forming the gas barrier layer is not particularly limited as long as it can exhibit gas barrier properties or water vapor barrier properties, but an inorganic oxide vapor deposited film such as an aluminum foil, an alumina vapor deposited film, or a silica vapor deposited film can be used. .

  When using the laminated body of this invention as a solar cell back surface protection sheet and producing a solar cell module, a well-known structure can be utilized except providing the said laminated body as a solar cell back surface protection sheet.

  An example of the solar cell module of the present invention is illustrated in FIG. In FIG. 2, the laminated body 10 provided with the weather resistant resin layer of this invention is used as a solar cell back surface protection sheet, and is combined with the sealing material 20, the power generation cell 30, the glass plate 40, and the frame 50 which seal a power generation cell. Thus, the solar cell module 1 is configured.

  In the solar cell module, a weather-resistant resin layer, a layer configuration of a film of a solar cell back surface protection sheet other than a laminate, a power generation cell that is a constituent material of the solar cell module, a sealing material that seals the power generation cell, a glass plate A known structure such as a frame can be used as it is.

  The features of the present invention will be further clarified by the following examples, comparative examples and test examples. However, the scope of the present invention is not limited to the examples.

Example 1
An acrylic polyol resin containing (meth) acrylic acid hydroxy ester and a copolymer of (meth) acrylic acid hydroxy ester was sampled so as to be 15% by mass with respect to 100% by mass of the urethane resin composition. These additives were added to the acrylic polyol resin so that the epoxy resin was 0.5% by mass, the polycarbonate resin was 0.5% by mass, and the titanium oxide was 50% by mass with respect to 100% by mass of the urethane resin composition. The main agent was prepared by mixing.

  A non-yellowing polyisocyanate was added to the prepared main agent as a curing agent to obtain a urethane resin composition. Content of the non-yellowing polyisocyanate in a urethane resin composition was 4 weight part with respect to 100 weight part of main ingredients.

  Next, a polyethylene terephthalate film (manufactured by Toyobo Co., Ltd .: trade name Toyobo Ester Film E5201) having a thickness of 125 μm was prepared as a resin film. On this resin film, the urethane resin composition prepared as described above is applied with a thickness of 5 μm by gravure printing, and cured by aging, thereby forming a weather resistant resin layer on the resin film and laminating. Got the body.

Comparative Example 1
A weather-resistant polyethylene terephthalate film (manufactured by Toray Industries, Inc., trade name: X10S, thickness 50 μm) was prepared and used as the weather-resistant resin layer of Comparative Example 1.

Comparative Example 2
Instead of the weather resistant resin layer, a weather resistant polyethylene terephthalate film (manufactured by Toray Industries, Inc., trade name: X10S, thickness 50 μm) was used, and the same procedure as in Example 1 was performed except that a urethane adhesive was used on the resin film. To obtain a laminate.

The application amount of the urethane adhesive was 10 g / m ² in terms of solid content, and was cured by aging.

Comparative Example 3
A laminate was obtained in the same manner as in Example 1 except that a PVF film (DuPont thickness 38 μm) was used instead of the weather-resistant resin layer and the resin film was adhered using a urethane adhesive.

The application amount of the urethane adhesive was 10 g / m ² in terms of solid content, and was cured by aging.

  The tests shown in Test Examples 1 to 3 below were performed on the laminates obtained in Example 1 and Comparative Examples 1 to 3 or the weather resistant resin layer.

Test example 1
<Evaluation of weather resistance (discoloration)>
As an evaluation of weather resistance, a UV irradiation test was conducted. Specifically, the color difference of the laminates obtained in Example 1 and Comparative Examples 1 to 3 or the weather resistant resin layer was measured using an X-Rite MA68IINS tester (manufactured by X-Rite Inc.). Color difference. Next, the laminates obtained in Example 1 and Comparative Examples 1 to 3 or the weather-resistant resin layer were irradiated with UV under the conditions of 1000 w / m ² , 300 to 400 nm, and 30 hr using a metal halide lamp. The color difference of the laminate irradiated with UV or the weather resistant resin layer was measured using the tester, and was defined as the color difference after UV irradiation. The difference between the initial color difference Δb * value and the color difference Δb * value after UV irradiation was calculated. When the difference between Δb * values is ≦ 3, it is difficult to judge discoloration by visual observation, so the evaluation result is “◯”. In addition, when the difference in Δb * values is> 3, the discoloration can be visually recognized, so the evaluation result is “x”. The results are shown in Table 1.

Test example 2
<Evaluation of weather resistance (change in elongation at break)>
The laminated body of Example 1 and Comparative Examples 1 to 3 or the weather resistant resin layer was evaluated for weather resistance (change in elongation at break after UV irradiation). Specifically, the elongation at break of each of the laminates obtained in Example 1 and Comparative Examples 1 to 3 or the weather resistant resin layer was measured to obtain the initial elongation at break. Moreover, the elongation at break was also measured for the laminate or the weather resistant resin layer irradiated with UV under the conditions of Test Example 1 described above, and the elongation after UV irradiation was determined.

  In addition, these breaking elongations cut out the laminated body of Example 1 and Comparative Examples 1-3, or a weather resistant resin layer to the magnitude | size of width 10mm and length 150mm, and made it into a sample, and used the strograph tester. The value obtained by measuring the elongation when the sample is broken under the condition of a tensile speed of 200 mm / min.

  When the measured value of the initial breaking elongation was set to 100%, the ratio of the measured value of the breaking elongation after UV irradiation was calculated in% to obtain the breaking elongation retention after UV irradiation. When the fracture elongation retention was 50% or more, the evaluation result was “◯”, and when it was less than 50%, the evaluation result was “x”. The results are shown in Table 1.

Test example 3
<Water resistance evaluation>
The laminates of Example 1 and Comparative Examples 1 to 3 or the weather resistant resin layer were evaluated for weather resistance (change in elongation at break after PCT test). Specifically, with respect to the laminates obtained in Example 1 and Comparative Examples 1 to 3, or the weather resistant resin layer, using a pressure cooker (PCT) tester, the temperature was 120 ° C., the humidity was 100%, the pressure was 0. The PCT test was conducted under conditions of 2 MPa and a test time of 50 hours.

  By measuring the initial breaking elongation and the breaking elongation after the PCT test in the same manner as in Test Example 2, the ratio of the measured value of the breaking elongation after the PCT test when the measured value of the initial breaking elongation is 100% It was calculated by% and used as the elongation at break after the PCT test. When the fracture elongation retention was 50% or more, the evaluation result was “◯”, and when it was less than 50%, the evaluation result was “x”. The results are shown in Table 1.

  As shown in Table 1, from the results of Test Examples 1 and 2, the laminate of Example 1 is a copolymer of (meth) acrylic acid hydroxy ester and (meth) acrylic acid hydroxy ester as the weather resistant resin layer. Therefore, it was found that discoloration after UV irradiation was suppressed, the elongation at break after UV irradiation was high, and the weather resistance was excellent. From the results of Test Example 3, it was found that the laminate of Example 1 had a high elongation at break after the PCT test and was excellent in water resistance.

  On the other hand, since the weather resistant resin layer of Comparative Example 1 and the laminate of Comparative Example 2 use a weather resistant polyethylene terephthalate film, discoloration occurs due to UV irradiation, and the elongation at break after UV irradiation is high. Low and inferior in weather resistance. Moreover, the weather resistant resin layer of Comparative Example 1 and the laminate of Comparative Example 2 had a low elongation at break after the PCT test and were inferior in water resistance.

  Moreover, since the laminated body of Comparative Example 3 uses a PVF film as the weather resistant resin layer, the weather resistant resin layer permeates moisture, so that the lower resin film deteriorates and breaks and stretches after the PCT test. It was found that the degree retention was low and the water resistance was poor.

1. Solar cell module 10. Laminated body 11. Weather resistant resin layer 12. Resin film 20. Sealing material 30. Power generation cell 40. Glass plate 50. flame

Claims (10)

(1) a main agent containing an acrylic polyol resin containing a (meth) acrylic acid hydroxy ester and a copolymer of (meth) acrylic acid hydroxy ester , and
(2) including a curing agent which is a polyisocyanate compound,
The weather-resistant resin layer , wherein the content of the curing agent is 2 to 10 parts by mass with 100 parts by mass of the main agent .   The weather resistant resin layer according to claim 1, wherein the content of the acrylic polyol resin is 5 to 40 mass% with respect to 100 mass% of the weather resistant resin layer.   The weather resistant resin layer according to claim 1 or 2, which contains 10 to 60% by mass of titanium oxide.   The weather resistant resin layer according to any one of claims 1 to 3, comprising 0.5 to 6.0 mass% of an epoxy resin.   The weather-resistant resin layer according to any one of claims 1 to 4, comprising 0.5 to 6.0% by mass of a polycarbonate resin. The weather resistant resin layer according to any one of claims 1 to 5, wherein the polyisocyanate compound includes a non-yellowing polyisocyanate.   A laminate having the weatherable resin layer according to any one of claims 1 to 6 laminated on at least one surface of a resin film.   The laminate according to claim 7, wherein the resin film includes polyethylene terephthalate.   The laminated body of Claim 7 or 8 which is a solar cell back surface protection sheet.   The solar cell module obtained using the laminated body in any one of Claims 7-9.

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