JP2013098242A - Solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar cell module, having sufficient adhesiveness, comprising a solar cell encapsulation resin layer formed by composing a material which irregularly reflects light, excellent in long-term reliability, and capable of improving power generation efficiency.SOLUTION: The solar cell module is composed of a modified polyolefin resin composition which is formed by modifying a polyolefin resin (a) mixed with 0.01 to 5 wt.% of a metal oxide (e) whose number average particle size is 0.05 to 10 μm, and is encapsulated with a sheet for a solar cell encapsulation composed of 100 wt.% of a light scattering heat-fusible resin composition.

Description

  The present invention relates to a heat-weldable sheet molded body for solar cell sealing, a manufacturing method thereof, and a solar cell module sealed by the method.

  In recent years, needs for bonding different materials have been increasing. In the automobile industry, examples include bonding a metal material and a resin in order to enhance designability, and bonding glass and crystalline silicon in the field of solar cells.

  On the other hand, examples of the resin excellent in adhesion to metal include nylon resins and polyester resins having polar functional groups, but they are more expensive than general-purpose resins such as polyolefin and polystyrene. Nylon resins and polyester resins exhibit adhesion to metals, but have poor adhesion to polyolefin resins that are frequently used in automobile members. Examples of the resin that adheres to glass include an ethylene / vinyl acetate copolymer (hereinafter abbreviated as EVA) resin that is used as a sealing material for solar cells, and the EVA resin itself adheres to glass. At present, the adhesive strength is increased with a silane coupling agent or the like.

  Patent Document 1 describes that an organic peroxide is used in combination with this EVA resin component as a cross-linking agent and a silane coupling agent is blended, but the adhesiveness to the glass substrate is not satisfactory. Absent.

  Patent Document 2 describes the blending of a silane coupling agent into a sealing material resin in a solar cell module using an EVA film and an FRP substrate. After covering the battery element with a resin sealing material, it is heated and temporarily bonded for about several minutes, and is heated and bonded for several hours to one hour at a high temperature at which the organic peroxide decomposes in the oven. Adhesion with the substrate is not sufficient.

  Further, in recent years, a sheet that protects the back surface of a solar cell is preferably blended with a component that diffuses light (see Patent Document 3). This is because the sunlight that is irregularly reflected by the sheet protecting the back surface (back sheet) strikes the solar cell power generation layer again, thereby increasing the power generation efficiency.

JP-A-9-116182 JP 2003-204073 A Japanese Patent No. 4766192

  An object of the present invention is to provide a solar cell module having a solar cell encapsulating resin layer having a sufficient adhesive property and blending a substance that diffuses and reflects light, having excellent long-term reliability and improved power generation efficiency Is to provide.

  As a result of intensive studies in view of the above-described present situation, the present inventors have added a metal oxide to a specific modified resin composition and formed a solar cell module including an encapsulating sheet made of the above-described back. As in the case of the sheet, the power generation efficiency is improved, and since the performance deterioration as a sealing sheet due to the addition of metal oxide does not occur, it has been found that the above problems can be solved, and the present invention has been completed. .

  That is, in the present invention, 0.01 to 5% by weight of a metal oxide (e) having a number average particle size of 0.05 to 10 μm is blended in a modified polyolefin resin composition obtained by modifying a polyolefin resin (a). The present invention relates to a solar cell module that is sealed with a solar cell sealing sheet made of 100% by weight of a light-scattering heat-welding resin composition.

  A preferred embodiment is that the polyolefin resin (a) is at least one selected from the group consisting of LDPE, LLDPE, soft polypropylene resin, and ethylene butene copolymer.

In a preferred embodiment, the modified polyolefin resin composition is obtained by melting and kneading the following (a), (b), (c), and (d) in an extruder: It is to be.
(A) 100 parts by weight of polyolefin resin,
(B) 0.01 parts by weight to 5 parts by weight of a radical polymerization initiator,
(C) Epoxy group-containing vinyl monomer 0.01 to 10 parts by weight (d) Aromatic vinyl monomer 0 to 3 parts by weight In a preferred embodiment, the polyolefin resin (a) has a heat of fusion of 10 J / It is preferable to use an ethylene-propylene copolymer having an ethylene content of 1 to 30% by weight.

  A preferred embodiment is that the epoxy group-containing vinyl monomer (c) is glycidyl (meth) acrylate.

In a preferred embodiment, the solar cell sheet has a water vapor barrier property of less than 2 {(g / m ² · day) /0.4 mm} and has an adhesive strength with glass when bonded at 170 ° C. The solar cell sealing sheet has a width of 80 N / 10 mm or more (180 degree peel test).

Furthermore, this invention is a manufacturing method of such a solar cell module of this invention, Comprising:
Stranding step of extruding the modified polyolefin resin composition as a strand from an extruder,
The present invention relates to a method for manufacturing a solar cell module, which includes an attaching step of attaching the metal oxide (e) to the surface of the strand, and a pelletizing step of cutting and stranding the strand.

  In a preferred embodiment, in the attaching step, the strand immediately after the stranding step is passed through cooling water containing the metal oxide (e), so that the strand is cooled and the metal oxide on the surface of the strand is cooled. It is to make it the manufacturing method which performs adhesion of (e).

  A preferred embodiment is a manufacturing method in which ultrasonic vibration energy is imparted to the cooling water.

  Since the solar cell module of the present invention has a sealing layer that efficiently diffuses and reflects sunlight, the power generation efficiency is high. Moreover, since the sealing sheet adheres well to the solar cell power generation layer and the surface glass, the long-term reliability is excellent.

  Details of the present invention will be described below.

(Sheet cell sealing sheet or film)
The solar cell sealing sheet or solar cell sealing film according to the present invention is a modified polyolefin resin composition 100 in which 0.01 to 5 wt% of a metal oxide is blended in a specific modified resin composition. It consists of wt%, and the solar cell element is encapsulated using the solar cell encapsulating sheet of the present invention. A solar cell module with improved photoelectric conversion efficiency due to a light scattering effect can be obtained.

  Such a light-scattering heat-weldable resin composition according to the present invention is molded and provided as a resin sheet having heat-weldability as a solar cell module sealing member. In the solar cell module of the present invention, the solar cell A sealing layer for sealing the element is formed. Therefore, from the viewpoint of ensuring excellent long-term reliability that can withstand outdoor use, it is excellent in hydrolysis resistance, and adheres to protective members such as glass plates, light-resistant PET films, fluororesins, and solar cell elements. It is preferable to use a heat-welding resin composition mainly composed of an epoxy-modified polyolefin resin composition having excellent properties.

  The heat-weldability referred to in the present invention refers to the property of melting with heat and joining to the adherend. The thickness can be 3 to 10 mm, preferably 10 to 5 mm, more preferably 100 to 1 mm, and further preferably 200 to 600 μm, and can be used as a sheet or film.

  Such a solar cell sealing sheet according to the present invention is obtained by using the light-scattering heat-welding resin composition according to the present invention with various extrusion molding machines, injection molding machines, calendar molding machines, inflation molding machines, roll moldings. It can be manufactured by molding into a sheet using a machine or a hot press molding machine. Among these, it is preferable from the viewpoint of dispersibility of the metal oxide in the resin to use an extrusion molding machine having a screw configuration with a strong shearing force or a calender molding machine excellent in rolling ability.

(Modified polyolefin resin composition)
The modified polyolefin resin composition according to the present invention is obtained by melt-kneading the following (a), (b), (c), and (d) from the viewpoint of adhesion to glass and the like and the expression of the light scattering effect. It is preferable to make a composition in which (e) is further blended with the epoxy-modified polyolefin resin characterized by being obtained in the above manner.
(A) 100 parts by weight of a non-modified polyolefin resin,
(B) 0.01 parts by weight to 5 parts by weight of a radical polymerization initiator,
(C) Epoxy group-containing vinyl monomer 0.01-20 parts by weight (d) Aromatic vinyl monomer 0-2 parts by weight (e) Metal oxide 0.01-5 parts by weight Further, adhesion to glass In order to improve the property, it is preferable to reduce the number of added parts of the aromatic vinyl monomer. Preferably it is 0-1 weight part, More preferably, it is 0-0.5 weight part. Further, from the viewpoint of improving the power generation efficiency of the solar cell by obtaining the light scattering effect inside the sheet while suppressing the shielding effect, it is preferable that the metal oxide is added in the above range of parts.

  In the modified polyolefin resin composition, (a) an unmodified polyolefin resin was grafted with a graft chain composed of (c) an epoxy group-containing vinyl monomer and (d) an aromatic vinyl monomer. A resin composition obtained by a graft polymerization reaction is preferable from the viewpoint of increasing graft efficiency.

  If necessary, various stabilizers and various additives may be added to the modified polyolefin resin composition of the present invention as long as the effects of the present invention are not impaired.

  The graft polymerization reaction used in the present invention is not particularly limited, and solution polymerization, impregnation polymerization, melt polymerization and the like can be used. In particular, melt polymerization is simple and preferable. The heating temperature at the time of melt-kneading is preferably 100 to 250 ° C. from the viewpoint that the polyolefin-based resin is sufficiently melted and is not thermally decomposed. The time for melt kneading (the time after mixing the radical polymerization initiator) is usually 30 seconds to 60 minutes.

  Further, as the melt kneading apparatus, an extruder, a Banbury mixer, a mill, a kneader, a heating roll, or the like can be used. From the viewpoint of productivity, a method using a single-screw or twin-screw extruder is preferred. Moreover, in order to mix each material sufficiently uniformly, the melt kneading may be repeated a plurality of times.

(Radical initiator (b))
Examples of the radical polymerization initiator generally include peroxides and azo compounds, but those having a high hydrogen abstraction ability are preferable. Examples of such a radical polymerization initiator include 1,1-bis (t-butyl). Peroxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, n-butyl-4,4-bis (t-butylperoxy) valerate, 2,2-bis Peroxyketals such as (t-butylperoxy) butane; dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, α, α'-bis (t-butylper Oxy-m-isopropyl) benzene, t-butylcumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di (t- Dialkyl peroxides such as tilperoxy) hexyne-3; diacyl peroxides such as benzoyl peroxide; t-butylperoxyoctate, t-butylperoxyisobutyrate, t-butylperoxylaurate, t-butylperoxy -3,5,5-trimethylhexanoate, t-butylperoxyisopropyl carbonate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxyacetate, t-butylperoxy One or more of peroxyesters such as benzoate and di-t-butylperoxyisophthalate can be used.

  The addition amount of the radical polymerization initiator is preferably in the range of 0.01 to 5 parts by weight with respect to 100 parts by weight of the unmodified polyolefin resin (a), and 0.05 to 3 parts by weight. More preferably, it is within the range. If the amount is less than 0.01 parts by weight, the modification does not proceed sufficiently. If the amount exceeds 5 parts by weight, the fluidity and mechanical properties of the polyolefin are significantly reduced.

(Epoxy group-containing vinyl monomer (c))
Examples of the epoxy group-containing vinyl monomer include glycidyl methacrylate, glycidyl acrylate, monoglycidyl maleate, diglycidyl maleate, monoglycidyl itaconate, diglycidyl itaconate, monoglycidyl allyl succinate, diglycidyl allyl succinate, p- Styrene carboxylic acid glycidyl, allyl glycidyl ether, methallyl glycidyl ether, styrene-p-glycidyl ether, p-glycidyl styrene, 3,4-epoxy-1-butene, 3,4-epoxy-3-methyl-1-butene, etc. 1 type or 2 types or more, such as epoxy olefin of this, vinylcyclohexene monooxide, etc. are mentioned.

  Of these, glycidyl methacrylate and glycidyl acrylate are preferable in that they are inexpensive.

  The addition amount of the epoxy group-containing vinyl monomer is a non-modified polyolefin resin (a) from the viewpoint of molding and processing as a solar cell sealing sheet having a suitable shape and appearance while ensuring sufficient adhesiveness. ) It is preferably 0.01 to 20 parts by weight, more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight.

(Aromatic vinyl monomer (d))
Examples of the aromatic vinyl monomer include styrene; methyl styrene such as o-methyl styrene, m-methyl styrene, p-methyl styrene, α-methyl styrene, β-methyl styrene, dimethyl styrene, and trimethyl styrene; o-chloro Chlorostyrenes such as styrene, m-chlorostyrene, p-chlorostyrene, α-chlorostyrene, β-chlorostyrene, dichlorostyrene, trichlorostyrene; o-bromostyrene, m-bromostyrene, p-bromostyrene, dibromostyrene, Bromostyrene such as tribromostyrene; fluorostyrene such as o-fluorostyrene, m-fluorostyrene, p-fluorostyrene, difluorostyrene, trifluorostyrene; o-nitrostyrene, m-nitrostyrene, p-nitrostyrene, di Nitrostyrenes such as trostyrene and trinitrostyrene; vinylphenols such as o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, dihydroxystyrene, and trihydroxystyrene; o-divinylbenzene, m-divinylbenzene, and p-divinyl One kind or two or more kinds of divinylbenzene such as benzene; diisopropenylbenzene such as o-diisopropenylbenzene, m-diisopropenylbenzene and p-diisopropenylbenzene;

  Of these, styrene, α-methyl styrene, methyl styrene such as p-methyl styrene, divinylbenzene monomer or divinylbenzene isomer mixture are preferred because they are inexpensive, and styrene is particularly preferred.

  The amount of the (d) aromatic vinyl monomer added is preferably 3 parts by weight or less with respect to 100 parts by weight of the polyolefin-based resin, in order to improve the adhesion to glass, or transparency. In order to maintain, it is more preferable that the amount is as small as possible. The addition amount within the above range is preferable because the graft efficiency of the (c) epoxy group-containing vinyl monomer to the polyolefin resin can be kept high. On the other hand, if the addition amount exceeds 3 parts by weight, the copolymer with the (c) epoxy group-containing vinyl monomer forms a large domain, and thus the transparency tends to decrease, which is not preferable.

(Metal oxide (e))
In the present invention, a metal oxide is added to the modified polyolefin composition for solar cell encapsulating material to form a white or slightly white light scattering sheet. Examples of the metal oxide include titanium oxide, zinc oxide, zinc sulfide, barium sulfate, alumina, talc, silica and the like, preferably titanium dioxide, barium sulfate, particularly preferably titanium dioxide.

  The number average particle diameter of the metal oxide is preferably 0.005 μm or more, more preferably 0.01 μm or more, and particularly preferably 0.05 μm or more. If the number average particle diameter is less than 0.005 μm, the wavelength of light that can be efficiently scattered shifts to the short wavelength side, and thus the reflectance in the visible light region may decrease. If the number average particle size of the metal oxide exceeds 10 μm, depending on the particle size distribution, coarse particles may be included, which may cause problems such as pinholes in the sheet. It is preferable that it is 10 micrometers or less.

  The content of the metal oxide is 0.01 to 5% by weight, preferably 0.1 to 4% by weight, and more preferably 0.5 to 2% by weight. If the content of the metal oxide is less than 0.01% by weight, incident light cannot be scattered efficiently. On the other hand, when the content of the metal oxide exceeds 5% by weight, the shielding effect is enhanced, and the effect of improving the power generation efficiency of the solar cell cannot be obtained.

(Method of blending metal oxide (e))
As a method for incorporating a metal oxide into the solar cell encapsulating sheet of the present invention, it is preferable to blend by the following method. That is, the strand (diameter 2 mm to 8 mm) from which the modified polyolefin resin composition produced by the above-described method was discharged from an extruder was passed through a water tank containing cooling water containing a metal oxide. The metal oxide is deposited.

  Thus, the metal oxide adhered to the strand surface not only functions as a light scattering agent according to the present invention, but also functions as an adhesion preventing agent that prevents the strands from sticking to each other. The strand to which such a metal oxide is attached has an effect that the process becomes easy in the subsequent pelletizing process.

  In the water tank, the metal oxide may be suspended on the surface layer of the cooling water, or may be uniformly dispersed in the cooling water when sinking in the water. In the case of dispersing in cooling water, it is preferable to stir the cooling water by attaching a stirrer to the water tank, and it is more preferable to finely disperse the white pigment in water with an ultrasonic disperser. In addition, a metal oxide dispersed in water or an organic solvent in advance may be used as cooling water for the cooling water tank, or the metal oxide dispersion may be diluted with water added to the water in the water tank. Good.

  If the strand diameter discharged from the extruder is 2 mm or less, the pelletizer may not be able to cut with a pelletizer, and problems may occur. If it is 8 mm or more, the pellet shape will not be uniform due to insufficient cooling. Moreover, the compounding quantity of the metal oxide adhering to a strand can be adjusted by adjusting a strand diameter between 2-8 mm. The advantage of blending a metal oxide by the above-mentioned method is that a monomer having a functional group reactive to acids and bases can be used to modify the resin and simultaneously blend the target metal oxide. It is. When the metal oxide is added to the extruder during the production of such a modified resin, the functional group of the monomer reacts with the acidic or basic functional group on the surface of the metal oxide, and the target modified resin. It is considered that a composition cannot be obtained.

(Solar cell module)
The solar cell module of the present invention is a state in which the light-scattering heat-welding resin composition layer according to the present invention is sandwiched as a sealing layer, and a protective member such as a glass plate, a light-resistant PET film, or a fluorine-based resin, and It is a solar cell module provided with a solar cell element.

(Solar cell element)
As the solar cell element according to the present invention, from the viewpoint of maximizing the sealing performance and light scattering effect of the specific resin composition according to the present invention, a solar cell having finger electrodes and tab wires on the light receiving surface side. An element is preferable, and a crystalline silicon solar cell element is more preferable.

  Specific examples are shown below, but the present invention is not limited to the following examples. In the following examples and comparative examples, “parts” and “%” represent “parts by weight” and “% by weight”, respectively.

<Crosslinking EVA sheet for sealing>
Made by Sanvic: Ultra Pearl, 0.40mm thickness, first cure type

<Light-receiving side transparent protective member>
AGC's white plate semi-tempered glass for solar cells (400 mm x 400 mm x 3.2 mm) (used in crystal modules)

<Back side protection member (back sheet)>
ISOVOLTA: PVF / PET / PVF backsheet (approx. 330 μm) was used to make a crystal-based module.
ISOVOLTA: icosolar s / s 2116 was used to make the thin film module.

<Crystalline solar cell element>
A Qcells 3 bus bar wiring 6-inch polycrystalline cell (180 μm thick) with a 4-cell series structure was used as a crystalline solar cell element.

<Thin film solar cell element>
An amorphous solar cell substrate of 5 inches in length and 5 inches in width (a product in which a power generation element was formed by vapor deposition and processing of silicon or the like on glass, manufactured by Kaneka Corporation) was used as a thin film solar cell element.

<Wiring material>
Hitachi Cable Co., Ltd .: A-SPS (2AG) -0.2mm × 2.0mm
The measuring method and evaluation method of each physical property in Examples and Comparative Examples are as follows.

  <Condition of Integrated Molding> A solar cell module was manufactured by integrally molding the whole with a sheet sample sandwiched between the protective member and the solar cell element.

The integral molding was carried out by degassing at 170 ° C. for 3.5 minutes, followed by thermocompression bonding at 170 ° C. with a press pressure of 1 kg / cm ² and a press time of 10 minutes. A vacuum laminator (manufactured by NPC, LM-50 × 50-S) was used for thermocompression bonding.

  When an EVA-based resin sheet was used as the sheet sample, after integrally molding (thermocompression bonding) under the above conditions, the EVA was further cross-linked by heating in an oven at 150 ° C. for 120 minutes. Heating at 150 ° C. for 120 minutes by sealing with EVA is a condition required for the EVA layer in the solar cell module state to exhibit physical properties necessary as a solar cell sealing material by crosslinking EVA. It is.

[Ash content measurement]
An electric furnace was used to quantify the metal oxide in the modified polyolefin sheet containing the metal oxide. 10 g of the solar cell sealing sheet was placed in a crucible and treated in an electric furnace at 600 ° C. for 3 hours. From the amount of the metal oxide remaining in the crucible, the weight percent of the metal oxide in the solar cell sealing sheet was calculated.

[Solar cell output evaluation]
The solar cell module maintained at 25 ° C. was irradiated with pseudo-sunlight with AM 1.5 and irradiation intensity of 1000 mW / cm ² from the solar simulator, the maximum output [W] (JIS C8911 1998) was measured, and the power generation efficiency was calculated.

[Heat and humidity resistance evaluation]
The solar cell module maintained at 25 ° C. was irradiated with pseudo-sunlight with AM 1.5 and irradiation intensity of 1000 mW / cm ² from the solar simulator, and the initial value of the maximum output [W] (JIS C8911 1998) was measured.

  Next, a heat and humidity resistance test was performed in which the solar cell module was left in an environment of a temperature of 85 ° C. and a humidity of 85% RH.

The post-test value of the maximum output [W] was measured in the same manner as described above for the solar cell module after standing for a certain period of time, and the superiority or inferiority of the heat and humidity resistance was evaluated based on the ratio of the post-test value to the initial value. Table 1 shows the evaluation results based on the following criteria.
○: A ratio of 0.95 or more is maintained after 1000 hours of standing.
(Triangle | delta): It will be less than 0.95 ratio after leaving for 500 hours or more and less than 1000 hours.
X: The ratio is less than 0.95 after standing for less than 500 hours.

[Water vapor barrier]
According to JIS K7126-1 (differential pressure method), the moisture permeability is measured in units of {(g / m ² · day) under the conditions of 40 ° C./90% RH, permeation area 15.2 cm 2, pressure difference 75 cmHg per 0.4 mm thick sheet sample. ) /0.4 mm}. It shows that it is excellent in water vapor | steam barrier property, so that this value is small.

(Production Example 1)
As ethylene-propylene copolymer (a), 100 parts by weight of Versify 3401.05 (Random polymer of MFR = 8, weight ratio (propylene: ethylene) = 85: 15) manufactured by Dow Chemical Co., and radical polymerization initiator (b) 1,3-di (t-butylperoxyisopropyl) benzene (manufactured by NOF Corporation: Perbutyl P, 1 minute half-life 175 ° C.) 0.5 parts by weight Vent set at a cylinder temperature of 200 ° C. and a screw speed of 150 rpm Melt-kneading was started by feeding to a twin screw extruder (46 mmφ, L / D = 63, manufactured by Kobe Steel, HYPER KTX46), and an epoxy group-containing vinyl monomer (c ) These components are melt-kneaded by adding 2 parts by weight of glycidyl methacrylate, and modified polyolefin resin composition It was created.

  This modified polyolefin resin composition was taken out from the die of the extruder as a 4 mm diameter strand, and metal oxide (e) (rutile titanium dioxide, R-11P, average particle size 0.2 μm, manufactured by Sakai Chemical Industry Co., Ltd.) ) Was cooled in a water tank floated on the water surface and pelletized to obtain pellets. The MFR was 50.

This modified polyolefin resin composition was adjusted so as to have a thickness of 400 μm by supplying a molten resin to a 500 mm wide extrusion T-die and extruding it as a sheet-like molten resin. The amount of the metal oxide in the sheet was 0.5 part, and the water vapor barrier property of the sheet was 2.5 {(g / m ² · day) /0.4 mm}.

(Production Example 2)
As ethylene-propylene copolymer (a), 100 parts by weight of Versify 3401.05 (Random polymer of MFR = 8, weight ratio (propylene: ethylene) = 85: 15) manufactured by Dow Chemical Co., and radical polymerization initiator (b) 1,3-di (t-butylperoxyisopropyl) benzene (manufactured by NOF Corporation: Perbutyl P, 1 minute half-life 175 ° C.) 0.5 parts by weight Vent set at a cylinder temperature of 200 ° C. and a screw speed of 150 rpm Melt-kneading was started by feeding to a twin screw extruder (46 mmφ, L / D = 63, manufactured by Kobe Steel, product name HYPER KTX46), and an epoxy group-containing vinyl monomer from the middle of the cylinder of the extruder (C) By adding 2 parts by weight of glycidyl methacrylate, these components are melt-kneaded to obtain a modified polyolefin resin We create a composition.

  This modified polyolefin resin composition was taken out from the die of the extruder with a 3 mm diameter strand, and metal oxide (e) (rutile titanium dioxide, R-11P, average particle size 0.2 μm, manufactured by Sakai Chemical Industry Co., Ltd.) ), The metal oxide was dispersed in water, cooled in a water bath finely dispersed with an ultrasonic transmitter (manufactured by SMT), and pelletized to obtain pellets. The MFR was 50.

This modified polyolefin resin composition was adjusted so as to have a thickness of 400 μm by supplying a molten resin to a 500 mm wide extrusion T-die and extruding it as a sheet-like molten resin. The amount of the metal oxide in the sheet was 1 part, and the water vapor barrier property of the sheet was 2.4 {(g / m ² · day) /0.4 mm}.

(Production Example 3)
As ethylene-propylene copolymer (a), 100 parts by weight of Versify 3401.05 (Random polymer of MFR = 8, weight ratio (propylene: ethylene) = 85: 15) manufactured by Dow Chemical Co., and radical polymerization initiator (b) 1,3-di (t-butylperoxyisopropyl) benzene (manufactured by NOF Corporation: Perbutyl P, 1 minute half-life 175 ° C.) 0.5 parts by weight Vent set at a cylinder temperature of 200 ° C. and a screw speed of 150 rpm Melt-kneading was started by feeding to a twin screw extruder (46 mmφ, L / D = 63, manufactured by Kobe Steel, product name HYPER KTX46), and an epoxy group-containing vinyl monomer from the middle of the cylinder of the extruder (C) By adding 2 parts by weight of glycidyl methacrylate, these components are melt-kneaded to obtain a modified polyolefin resin We create a composition.

  This modified polyolefin resin composition is taken out from the die of the extruder with a strand having a diameter of 3 mm, and an aqueous dispersion containing a metal oxide (e) (titanium oxide aqueous dispersion “Nanotech”, manufactured by CI Kasei Co., Ltd., oxidized (Titanium particle size 0.02 to 0.03 μm, concentration 15% by weight) was used for cooling water in the water tank, further finely dispersed with an ultrasonic transmitter (manufactured by SMT), cooled, and pelletized to obtain pellets. . The MFR was 50.

This modified polyolefin resin composition was adjusted so as to have a thickness of 400 μm by supplying a molten resin to a 500 mm wide extrusion T-die and extruding it as a sheet-like molten resin. The amount of the metal oxide in the sheet was 1.5 parts, and the water vapor barrier property of the sheet was 2.3 {(g / m ² · day) /0.4 mm}.

(Production Example 4)
As ethylene-propylene copolymer (a), 100 parts by weight of Versify 3401.05 (Random polymer of MFR = 8, weight ratio (propylene: ethylene) = 85: 15) manufactured by Dow Chemical Co., and radical polymerization initiator (b) 1,3-di (t-butylperoxyisopropyl) benzene (manufactured by NOF Corporation: Perbutyl P, 1 minute half-life 175 ° C.) 0.5 parts by weight Vent set at a cylinder temperature of 200 ° C. and a screw speed of 150 rpm Melt-kneading was started by feeding to a twin screw extruder (46 mmφ, L / D = 63, manufactured by Kobe Steel, product name HYPER KTX46), and an epoxy group-containing vinyl monomer from the middle of the cylinder of the extruder (C) By adding 2 parts by weight of glycidyl methacrylate, these components are melt-kneaded to obtain a modified polyolefin resin We create a composition.

  The modified polyolefin resin composition was taken out from the die of the extruder as a 4 mm diameter strand, cooled in a water tank, and pelletized to obtain pellets. The MFR was 50.

This modified polyolefin resin composition was adjusted so as to have a thickness of 400 μm by supplying a molten resin to a 500 mm wide extrusion T-die and extruding it as a sheet-like molten resin. The water vapor barrier property was 2.5 {(g / m ² · day) /0.4 mm}.

Example 1
A crystalline cell solar cell module was prepared using EVA as the sealing sheet on the light-receiving surface glass side and (Sealing Example 1) as the sealing sheet on the cell back side.

(Example 2)
A crystal cell solar cell module was prepared using EVA as the sealing sheet on the light-receiving surface glass side and (Sealing Example 2) as the sealing sheet on the cell back side.

(Example 3)
A crystalline cell solar cell module was prepared using EVA as the sealing sheet on the light-receiving surface glass side and (Sealing Example 3) as the sealing sheet on the cell back side.

Example 4
A crystal cell solar cell module was prepared using both the sealing sheet on the light-receiving surface glass side and the sealing sheet on the cell back side as a sheet of (Production Example 1).

(Example 5)
A crystal cell solar cell module was prepared using both the sealing sheet on the light-receiving surface glass side and the sealing sheet on the cell back side as a sheet of (Production Example 2).

(Example 6)
A crystal cell type solar cell module was prepared using both the sealing sheet on the light-receiving surface glass side and the sealing sheet on the cell back side as a sheet of (Production Example 3).

(Example 7)
A thin film solar cell module was prepared using the sheet of (Production Example 1).

(Example 8)
A thin film solar cell module was prepared using the sheet of (Production Example 2).

Example 9
A thin film solar cell module was prepared using the sheet of (Production Example 3).

(Comparative Example 1)
A crystal cell solar cell module was prepared using EVA as the sealing sheet on the light-receiving surface glass side and the sealing sheet on the cell back side.

(Comparative Example 1)
A crystal cell solar cell module was prepared using EVA as the sealing sheet on the light-receiving surface glass side and the sealing sheet on the cell back side.

(Comparative Example 2)
A crystal cell solar cell module was prepared using EVA as the sealing sheet on the light-receiving surface glass side and (Sealing Example 4) as the sealing sheet on the cell back side.

(Comparative Example 3)
A crystal cell solar cell module was prepared using both the light-receiving surface glass side sealing sheet and the cell back side sealing sheet (Production Example 4).

(Comparative Example 4)
A thin film solar cell module was prepared using an EVA sheet.

(Comparative Example 5)
A thin film solar cell module was prepared using the sheet of (Production Example 4).

  The output of the solar cell module created in (Example 1) to (Example 9) and (Comparative Example 1) to (Comparative Example 5) was measured, and the power generation efficiency was calculated. Moreover, when heat-and-moisture resistance evaluation was performed, it was confirmed that all the modules of Examples and Comparative Examples could be held for 1000 hours or more, and long-term reliability was ensured. The evaluation results are summarized in [Table 1].

  From the examples and comparative examples, it was confirmed that the solar cell module sealed with the solar cell sealing sheet of the present invention has improved power generation efficiency and long-term reliability.

Claims (10)

  A light-scattering composition comprising a modified polyolefin resin composition obtained by modifying a polyolefin resin (a) and 0.01 to 5% by weight of a metal oxide (e) having a number average particle size of 0.05 to 10 μm. A solar cell module sealed with a solar cell sealing sheet comprising 100% by weight of a heat-welding resin composition.   2. The solar cell module according to claim 1, wherein the polyolefin resin (a) is at least one selected from the group consisting of LDPE, LLDPE, soft polypropylene resin, and ethylene butene copolymer. . The modified polyolefin resin composition is an epoxy-modified polyolefin resin composition obtained by melt-kneading the following (a), (b), (c), and (d) in an extruder: The solar cell module according to claim 1 or 2.
(A) 100 parts by weight of polyolefin resin,
(B) 0.01 parts by weight to 5 parts by weight of a radical polymerization initiator,
(C) Epoxy group-containing vinyl monomer 0.01 to 10 parts by weight (d) Aromatic vinyl monomer 0 to 3 parts by weight   The solar cell module according to any one of claims 1 to 3, wherein the polyolefin resin (a) is a soft polypropylene resin having a heat of fusion of 10 J / g or less.   The solar cell module according to any one of claims 1 to 4, wherein the polyolefin resin (a) is an ethylene-propylene copolymer having an ethylene content of 1 to 30% by weight.   The solar cell module according to any one of claims 3 to 5, wherein the epoxy group-containing vinyl monomer (c) is glycidyl (meth) acrylate. The water vapor barrier property is less than 2 {(g / m ² · day) /0.4 mm}, and the adhesive strength with glass when bonded at 170 ° C. is 80 N / 10 mm width or more (180 degree peel test) The solar cell module according to claim 1, wherein It is a manufacturing method of the solar cell module in any one of Claims 1-7, Comprising:
Stranding step of extruding the modified polyolefin resin composition as a strand from an extruder,
The manufacturing method of the solar cell module characterized by including the adhesion process which makes the said metal oxide (e) adhere to the surface of this strand, and the pelletization process of cut | disconnecting and pelletizing this strand.   In the attaching step, the strand immediately after the stranding step is passed through cooling water containing the metal oxide (e) so that the metal oxide (e) adheres to the strand surface while cooling the strand. The manufacturing method of the solar cell module of Claim 8 which performs.   The method for manufacturing a solar cell module according to claim 8, wherein ultrasonic vibration energy is applied to the cooling water.