KR20150060692A - Sealing sheet and solar cell module obtained using same - Google Patents

Abstract

Provided are a sealing material sheet capable of maintaining a high generating performance with less deterioration of a solar cell element even when used for a long period under high temperature and high humidity without impairing high transparency, and a sealing material sheet using the same. The sealing material sheet of the present invention is a sealing material sheet having a layer A and a layer B, wherein the layer A is a layer containing ethylene-vinyl acetate copolymer as a main component and the layer B is a thermoplastic resin other than ethylene- And is a layer containing a further acidic agent.

Description

[0001] SEALING SHEET AND SOLAR CELL MODULE OBTAINED USING SAME [0002]

The present invention relates to a sealing material sheet.

The solar cell module is formed by laminating a sealing material sheet on both surfaces of a solar cell element including a semiconductor wafer such as single crystal silicon or polycrystalline silicon and stacking a protective material such as glass or back sheet on the upper and lower surfaces of the sealing material sheet, have.

Since the solar cell module is used over a long period of time in a harsh environment exposed to high temperature, high humidity, ultraviolet rays, and wind and rain, the sealing material is excellent in weather resistance and heat resistance that do not deteriorate by moisture or ultraviolet rays, And flexibility to protect the solar cell element from external impact. In addition, electrical insulation resistance and transparency to sufficiently reach the solar cell device are also required.

An ethylene-vinyl acetate copolymer is mainly used as a resin that meets the required properties at low cost. However, the ethylene-vinyl acetate copolymer is hydrolyzed by moisture penetrated into the inside of the module or decomposed by ultraviolet rays to produce an acid such as acetic acid, which causes deterioration of the solar cell element and electrode corrosion, And deteriorates module power generation performance.

In Patent Document 1, it has been proposed to disperse acid-acceptor particles having an average particle diameter of 5 μm or less in the ethylene-vinyl acetate copolymer to reduce the acid component in the glassy state in the sealing material.

Japanese Patent Application Laid-Open No. 2005-029588

However, in the sealing material described in Patent Document 1, there is a problem that the ethylene-vinyl acetate copolymer layer, which is the source of the acid, is in contact with the solar cell element and the electrode, so that it is insufficient to prevent deterioration of the solar cell element and electrode corrosion.

In view of the above-described problems of the prior art, the present invention provides a sealing material sheet capable of maintaining a high generating performance with little deterioration of a solar cell element even when used for a long period under high temperature and high humidity without impairing high transparency, And a solar cell module obtained by using the same.

The inventors of the present invention have found that the above problems can be solved by carrying out diligent studies to achieve the above object and taking the following constitution.

That is, the sealing material sheet according to the present invention is as follows.

As the sealing material sheet having the layer A and the layer B,

The layer A is a layer containing an ethylene-vinyl acetate copolymer as a main component,

Wherein said layer B is a layer containing a thermoplastic resin other than ethylene-vinyl acetate copolymer as a main component and further containing a hydroxyl group.

According to the present invention, it is possible to provide a sealing material sheet capable of maintaining a high generating performance with little deterioration of the solar cell element even when used for a long time under high temperature and high humidity without impairing high transparency, and a solar cell module using the same. The purpose.

1 is a schematic cross-sectional view of a sealing material sheet of the present invention.
2 is a schematic cross-sectional view of a solar cell module using the sealing material sheet of the present invention.

The sealing material sheet according to the present invention is a sealing material sheet having a layer A and a layer B, wherein the layer A is a layer containing ethylene-vinyl acetate copolymer as a main component and the layer B is a thermoplastic resin other than ethylene- As a main component, and further contains a hydroxyl group-containing agent.

Hereinafter, the sealing material sheet and the solar cell module of the present invention will be described.

≪ Seal material sheet &

Layer A is a layer containing ethylene-vinyl acetate copolymer as a main component. Here, the layer containing ethylene-vinyl acetate copolymer as a main component means that the total content of 100% by mass in the layer contains 50% by mass or more and 100% by mass or less of ethylene-vinyl acetate copolymer. It is important that the layer A contains ethylene-vinyl acetate copolymer as a main component. When the layer A does not satisfy this condition, flexibility of protecting the solar cell from external impact when such a sealing material sheet is embedded in the solar cell module And the like. The content of the ethylene-vinyl acetate copolymer in the layer A is preferably 70 mass% or more and 99.5 mass% or less, and more preferably 90 mass% or more and 99 mass% or less.

The vinyl acetate content of the ethylene-vinyl acetate copolymer as the main component of the layer A is preferably 15 to 40% by mass based on 100% by mass of the ethylene-vinyl acetate copolymer. If the vinyl acetate content of the ethylene-vinyl acetate copolymer as the main component of the layer A is less than 15% by mass, the transparency of the solar cell module may deteriorate and the power generation performance of the solar cell module may deteriorate. If 40% , There is a case that the handling property is lowered in the process of manufacturing the solar cell module. The vinyl acetate content of the ethylene-vinyl acetate copolymer as the main component of the layer A is more preferably 20 mass% or more and 35 mass% or less, and particularly preferably 25 mass% or more and 33 mass% or less.

The thickness of the layer A is preferably 0.1 mm or more and 1.0 mm or less. If the thickness of the layer A is less than 0.1 mm, the solar cell element may be damaged during lamination in the manufacturing process of the solar cell module. If the thickness of the layer A exceeds 1.0 mm, . The thickness of the layer A is more preferably 0.1 mm or more and 0.7 mm or less, and particularly preferably 0.3 mm or more and 0.5 mm or less.

It is preferable that the layer A contains an organic peroxide. When the layer A contains an organic peroxide, the sealing material sheet is heated in the solar cell module manufacturing process, the ethylene-vinyl acetate copolymer in the layer A can be crosslinked, and heat resistance and weather resistance can be expressed.

The organic peroxide suitable for inclusion in the layer A is not particularly limited but is selected in consideration of the temperature at the time of producing the sealing material sheet, the heating at the time of manufacturing the solar cell module, the bonding temperature, and the storage stability. Particularly, an organic peroxide having a decomposition temperature of 70 DEG C or higher at a half-life of 10 hours is preferable. Examples of such organic peroxides include dicumyl peroxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) Di-t-butyl peroxide, t-butyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl- Bis (t-butylperoxy) valerate, 2, 3'-bis (t-butylperoxy) Bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) butyl peroxybenzoate, benzoyl peroxide, t-butyl peroxyacetate, methyl ethyl ketone peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) Butyl peroxybenzoate, t-butyl hydroperoxide, p-tert-butyl peroxybenzoate, p-tert- - menthihydroperoxy , p-chlorobenzoyl peroxide, hydroxypepper peroxide, chlorohexanone peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, cumyl peroxyoctoate, succinic acid peroxide, Butyl peroxybenzoyl peroxide, t-butyl peroxide, t-butyl peroxybenzoyl peroxide, t-butyl peroxybenzoyl peroxide, t-butyl peroxybenzoyl peroxide, T-butylperoxy-2-ethylhexylcarbonate, 2,5-dimethyl-2,5-bis (benzoylperoxy) hexane, t-butylperoxyisononanoate, t- Butylperoxy benzoate, 1,1-bis (t-amylperoxy) cyclohexane, and ethyl-3,3-di (t-butylperoxy) butyrate. These organic peroxides may be contained in combination of two or more.

The content of these organic peroxides in the layer A is preferably 0.1 to 5 parts by mass, more preferably 0.1 to 3 parts by mass, and particularly preferably 0.1 to 2 parts by mass, relative to 100 parts by mass of the ethylene- Mass part. If the content of the organic peroxide in the layer A is less than 0.1 part by mass based on 100 parts by mass of the ethylene-vinyl acetate copolymer, the ethylene-vinyl acetate copolymer may not be able to be crosslinked. If the content of the organic peroxide is more than 5 parts by mass And the undissolved organic peroxide remains in the layer A, which may cause deterioration over time.

The layer A preferably further comprises a crosslinking aid. Herein, the crosslinking aid means a multifunctional monomer having a plurality of unsaturated bonds in the molecule. The multifunctional monomer having a plurality of unsaturated bonds in the molecule can react with the active radical compound generated by the decomposition of the organic peroxide to uniformly and efficiently crosslink the ethylene-vinyl acetate copolymer. Examples of the crosslinking aid include triallyl isocyanurate, triallyl cyanurate, trimethylol propane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, tris [(meth) acryloyloxyethyl] iso (Meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol ethoxytetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa ) Acrylate, divinylbenzene, and the like. These crosslinking aids may be used alone or in combination of two or more.

It is more preferable that the layer A further includes an ultraviolet absorber. The ultraviolet absorber absorbs harmful ultraviolet rays in the irradiated light and converts the harmful ultraviolet light into harmless heat energy in the molecule to prevent excitation of the active species of the photodegradation initiation in the polymer. As the ultraviolet absorber, any known ultraviolet absorber can be used. For example, benzophenone, benzotriazole, triazine, salicylic acid, cyanoacrylate, and the like can be used. These one species may be used alone or two or more species may be used in combination.

Of these ultraviolet absorbers, a benzophenone ultraviolet absorber is most preferable in terms of ultraviolet absorption effect and coloring of the ultraviolet absorber itself.

The content of the ultraviolet absorber in the layer A is preferably 0.1 to 3 parts by mass, more preferably 0.1 to 2.0 parts by mass based on 100 parts by mass of the ethylene-vinyl acetate copolymer in the layer A. [ When the content of the ultraviolet absorber in the layer A is less than 0.1 part by mass, the content effect is low, and if it is more than 3 parts by mass, coloring tends to occur.

The layer A preferably contains a light stabilizer. The light stabilizer captures harmful radical species to the polymer and prevents them from generating new radicals. As the light stabilizer, a hindered amine light stabilizer is preferably used.

Examples of the hindered amine light stabilizer include decanedioic acid bis (2,2,6,6-tetramethyl-1 (octyloxy) -4-piperidinyl) ester, 1,1-dimethylethyl hydroperoxide and octane (1, 2-dimethyl-4-piperidyl) [[3,5-bis (1,1-dimethyl Ethyl) -4-hydroxyphenyl] methyl] butyl malonate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and methyl-1,2,2,6,6 - pentamethyl-4-piperidyl sebacate mixture, and the like. The above-mentioned hindered amine light stabilizers may be used singly or in combination of two or more kinds.

Among them, hindered amine light stabilizers include bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and methyl-1,2,2,6,6-pentamethyl- It is preferable to use a mixture of 4-piperidyl sebacate and methyl-4-piperidyl sebacate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate. The hindered amine light stabilizers preferably have a melting point of 60 ° C or higher.

The content of the hindered amine light stabilizers in the layer A is preferably 0.1 to 3.0 parts by mass, more preferably 0.1 to 2.0 parts by mass based on 100 parts by mass of the ethylene-vinyl acetate copolymer in the layer A. [ If the content of the hindered amine light stabilizer in the layer A is less than 0.1 part by mass, the stabilizing effect is insufficient, and if the content exceeds 3.0 parts by mass, the coloring and the increase in cost are only caused.

In addition, the layer A may contain an antioxidant, a flame retardant, a flame-retardant aid, a plasticizer, a lubricant, and the like, if necessary, as additives that are already known within a range that does not impair the effects of the present invention.

Layer B is a layer containing a thermoplastic resin other than the ethylene-vinyl acetate copolymer as a main component and further containing a hydroxyl group.

Here, when the thermoplastic resin other than the ethylene-vinyl acetate copolymer is used as the main component, it means that the thermoplastic resin other than the ethylene-vinyl acetate copolymer accounts for 50% by mass or more and 100% by mass or less of 100% do. It is important that the layer B contains a thermoplastic resin other than the ethylene-vinyl acetate copolymer as a main component. When the ethylene-vinyl acetate copolymer is used in the layer B, when such a sealing material sheet is embedded in the solar cell module, Is in contact with the solar cell element and the electrode, deterioration of the solar cell element and electrode corrosion can not be prevented. The content of the thermoplastic resin other than the ethylene-vinyl acetate copolymer in the layer B is preferably 70 mass% or more and 99.5 mass% or less, and more preferably 90 mass% or more and 99.5 mass% or less.

Examples of the thermoplastic resin other than the ethylene-vinyl acetate copolymer which is the main component of the layer B include styrene resins such as polyester, polystyrene, acrylonitrile-styrene copolymer and acrylonitrile-butadiene-styrene copolymer, polyethylene, And polyolefin resins such as polyolefin resins such as polycarbonate, polyamide, polyether, polyurethane, polyphenylene sulfide, polyester amide, polyether ester, polyvinyl chloride, polymethacrylic acid ester, modified polyphenylene ether, Polysulfone, polyetherimide, polyamideimide, polyimide, and a copolymer mainly composed of these. These thermoplastic resins may be used singly or in combination of two or more.

The thermoplastic resin other than the ethylene-vinyl acetate copolymer which is the main component of the layer B is preferably a polyolefin resin in view of reduction of damage to the solar cell element in the lamination process, transparency, and productivity, Do. Of these, a density of 0.900g / cm ³ or less, preferably 0.890g / cm ³ or less, more preferably 0.870 to phosphorus, very low density range of 0.885g / cm ³ of polyethylene, linear low-density polyethylene is preferred.

The melting point (referred to as Tmb) of the thermoplastic resin other than the ethylene-vinyl acetate copolymer as the main component of the layer B is preferably higher than the melting point (Tma) of the ethylene-vinyl acetate copolymer as the main component of the layer A. That is, it is preferable that Tma <Tmb is satisfied. More preferably a form that satisfies Tma + 10? Tmb, and more preferably a form that satisfies Tma + 10? Tmb? Tma + 80. If the melting point of the thermoplastic resin other than the ethylene-vinyl acetate copolymer as the main component of the layer B is lower than the melting point of the ethylene-vinyl acetate copolymer as the main component of the layer A (i.e., Tma≥Tmb) The layer B in contact with the battery element melts, the thickness of the layer B becomes uneven, and the layer A directly contacts the solar cell element, so that the effect of the acid agent contained in the layer B may be reduced.

As described above, the layer B is a layer containing a thermoplastic resin other than the ethylene-vinyl acetate copolymer as a main component and further containing a hydroxyl group. The acid agent used herein is not particularly limited as long as it is a compound having a function of absorbing or neutralizing an acid, and may be used in any form.

Examples of the hydroxyl group contained in the layer B include an oxide of a Group II metal of the Periodic Table of the Elements, a hydroxide of a Group II metal of the Periodic Table of the Elements, a carbonate of a Group II metal of the Periodic Table of the Elements, , Borates of the Periodic Table of the Elements (II), silicates of the Periodic Table of the Elements (II), phosphites of the Periodic Table of the Elements (II), oxides of the Periodic Table of Elements (IV) Basic carboxylates of basic metals of the Periodic Table of the Elements, basic carboxylates of basic metals of Group IV of the Periodic Table of the Elements, basic phosphites of Group IV metals of the periodic table and basic sulfites of Group IV metals of Periodic Table of the Elements, An inclusion compound, and a Li-Al inclusion compound represented by the general formula (2).

The synthetic hydrotalcites represented by the formula (1)

(x and y are integers of 0 to 10, provided that x + y = 1 to 10, z is an integer of 1 to 5, and w is an integer of 0 to 10)

(2):

(Wherein X is an inorganic or organic anion, n is a valence of an anion X, and m is an integer of 3 or less)

Specific examples of such acidic agents include magnesium oxide, magnesium hydroxide, barium hydroxide, magnesium carbonate, barium carbonate, quicklime, calcium hydroxide, calcium carbonate, calcium silicate, calcium stearate, zinc stearate, calcium phthalate, calcium phosphite, tin oxide, Tin phosphite and the like.

Examples of the Li-Al inclusion complex represented by the general formula (1) include Mg ₃ ZnAl ₂ (OH) ₁₂ CO ₃ .wH ₂ O and the like.

Examples of the Li-Al inclusion complex represented by the general formula (2) include [Al ₂ Li (OH) ₆ ] ₂ CO ₃ .H ₂ O and the like.

Examples of the anionic species of the Li-Al inclusion compound include inorganic acids such as carbonic acid, sulfuric acid, perchloric acid, phosphoric acid, oxyacid, acetic acid, propionic acid, adipic acid, benzoic acid, phthalic acid, terephthalic acid, maleic acid, fumaric acid, Salicylic acid, and picric acid. These acid agents may be used alone or in admixture of two or more.

Among these acid generators, it is preferable to use at least one member selected from the group consisting of oxides, hydroxides, carbonates, carboxylates, borates, silicates and phosphites of the Group (II) Do.

In the case where the acid agent is a particle, the average particle diameter of the acid agent is not particularly limited, but a preferable upper limit is an average particle diameter of 5 mu m or less. If the average particle diameter of the acidic agent is larger than 5 占 퐉, the transparency of the sealing material sheet may be lowered, and sunlight may not be incident on the solar cell element in some cases.

When the thermoplastic resin as the main component of the layer B is 100 parts by mass with respect to the hydroxyl group in the layer B, the content of the hydroxyl group in the layer B is preferably 0.5 parts by mass or less, more preferably 0.01 parts by mass or more and 0.3 parts by mass or less to be. If the content of the hydroxyl group in the layer B exceeds 0.5 part by mass based on 100 parts by mass of the thermoplastic resin as the main component of the layer B, the transparency of the sealing material sheet may be lowered and the incidence of sunlight to the solar cell element There is a case.

The thickness of the layer B is preferably 0.01 mm or more and 1.0 mm or less, more preferably 0.05 mm or more and 0.1 mm or less. When the thickness of the layer B is less than 0.01 mm, the effect of absorbing or neutralizing the acid is insufficient in some cases. When the thickness exceeds 1.0 mm, the transparency is lowered and sunlight is prevented from entering the solar cell element .

In addition, the layer B may contain a crosslinking agent, a crosslinking aid, an antioxidant, a flame retardant, a flame retardant, a plasticizer, a lubricant, a nucleating agent and the like as necessary in addition to the known additives as long as the effect of the present invention is not impaired .

Next, a method of forming the sealing material sheet of the present invention will be described.

The sealing material sheet of the present invention can be produced by multilayering a desired multilayer by a known molding method using a T-die extruder, a calendar molding machine, an inflation molding machine or the like, or by forming sheets of respective layers separately and laminating them have. That is, the sealing material sheet may be laminated by known multilayer molding, or may be an extrusion laminate method in which each layer is molded in an individual molding machine and then laminated.

It is preferable that the sealing material sheet of the present invention is subjected to embossing on one side or both sides in terms of handling during production of a solar cell module and air leakage. Also, a known method is used for embossing. For example, a method of embossing with a forming roll immediately after being extruded from a T-die or the like, and a method of embossing the sheet after reheating the sheet extruded from a T-die or the like.

Next, a solar cell module using the sealing material sheet of the present invention will be described. The sealing material sheet of the present invention can be used either as a sealing material sheet (hereinafter, simply referred to as a light-receiving surface side sealing material sheet) disposed on the light receiving surface side of the solar cell module or as a sealing material sheet Quot; sheet &quot;).

The solar cell module 20 shown in Fig. 2 is provided with a transparent protective member 21 fixed by the light-receiving-surface-side seal member sheet 101 and a back-surface protective member 23 fixed by the backside seal member sheet 102, The solar cell element 22 is arranged between the light-receiving surface side sealing material sheet 101 and the back side sealing material sheet 102 and the light receiving surface side of the solar cell element 22 is directed toward the transparent member 21 side.

The solar cell module 20 of the present invention obtained by using the sealing material sheet of the present invention is manufactured as follows.

Side sealing material sheet 101 and the back side sealing material sheet 102 on both sides of the solar cell element 22 and the layer B 12 of the light-receiving-side sealing material sheet 101 on the solar cell element 22 side, The transparent protective member 21 and the back side sealing member 102 are arranged on both sides in addition to the light receiving surface side sealing member sheet 101 and the back side sealing member sheet 102 so that the layer B 12 of the sealing material sheet 102 is on the solar cell element 22 side. And a protective member 23 are disposed.

Subsequently, the laminate was heated in a vacuum laminator or the like at a temperature of 130 to 180 캜 for a degassing time of 2 to 15 minutes, followed by pressing under a press pressure of 0.1 to 1.5 kg / cm 2 and a pressing time of 8 to 45 minutes, Can be used to produce the solar cell module of the present invention. The temperature and time of heating can be appropriately changed depending on the composition and thickness of the sealing material sheet.

Example

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

(Example 1)

A two-layer co-extrusion apparatus in which two extruders were connected to one T die through a feed block was prepared. For layer A molding, one extruder of these two extruders was charged with an ethylene-vinyl acetate copolymer , 28 parts by mass (melting point: 71 占 폚), 0.5 part by mass of 2,5-dimethyl-2,5-di (t-butylperoxy) hexane as a crosslinking agent, 0.2 part by mass of? -Methacryloxypropyltrimethoxysilane as a coupling agent, 0.1 part by mass of 2,2'-dihydroxy-4,4'-di (hydroxymethyl) benzophenone as an ultraviolet absorber, And 0.3 parts by mass of bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate.

In the first stage for the layer B molding, a resin composition containing 100 parts by mass of ultra-low density polyethylene (melting point 115 캜) and 0.3 part by mass of magnesium hydroxide as a water-based agent was supplied.

Then, the resin composition was melted and kneaded at 120 ° C in each of the two extruders, the resin composition in a molten state was supplied to the feed block, the sheet thickness of the layer A from the T die arranged at the tip of the feed block was 0.4 mm, Extruded so as to have a thickness of 0.05 mm to form the sealing material sheet 10. Then, the sealing material sheet in a molten state just after being co-extruded from the T-die is fed between the embossing roll and the rubber roll disposed to face the embossing roll, and the embossing roll is pressed against the layer A side of the sealing material sheet in the molten state, The surface of the layer A of the sealing material sheet was subjected to embossing with a depth of 0.1 mm, followed by cooling and cooling with a cooling roll to obtain a two-layer sealing material sheet having a thickness of 0.45 mm.

(Example 2)

A sealing sheet was prepared in the same manner as in Example 1 except that the addition amount of the hydroxyl group-containing acid (magnesium hydroxide) in the layer B was changed to 1.0 part by mass.

(Example 3)

A sealing material sheet was prepared in the same manner as in Example 1 except that the kind of the hydroxyl group-containing agent in the layer B was changed from magnesium hydroxide to calcium phosphite.

(Example 4)

A sealing sheet was prepared in the same manner as in Example 1 except that the addition amount of the acid agent (magnesium hydroxide) in the layer B was changed to 0.5 parts by mass.

(Example 5)

A sealing material sheet was prepared in the same manner as in Example 1 except that the ultralow low density polyethylene (melting point 115 캜), which is the main component of layer B, was changed to linear low density polyethylene (melting point 68 캜).

(Comparative Example 1)

A sealing material sheet was prepared in the same manner as in Example 1 except that the addition of the hydroxyl group-containing acid (magnesium hydroxide) in the layer B was not performed.

(Comparative Example 2)

100 parts by mass of an ethylene-vinyl acetate copolymer (vinyl acetate content: 28% by mass), 0.5 parts by mass of 2,5-dimethyl-2,5-di (t-butylperoxy) Methacryloxypropyltrimethoxysilane as a silane coupling agent for improving adhesion to a glass substrate, 0.2 part by mass of 2,2'-dihydroxy-4,4'-di (hydride (1, 2, 2, 6, 6-pentamethyl-4-piperidyl) sebacate as a photostabilizer, 0.3 part by mass of magnesium hydroxide as a water-based agent Was supplied.

Subsequently, the resin composition was melt-kneaded at 120 DEG C, and the resin composition in a molten state was supplied to a T-die to form a solar cell sealing material sheet by extruding a sheet having a thickness of 0.45 mm. Then, the sealing material sheet in a molten state just after being co-extruded from the T-die is fed between the embossing roll and the rubber roll arranged to face the embossing roll, and the embossing roll is pressed against the layer A of the sealing material sheet in the molten state, The surface of the layer A of the sheet was embossed with a depth of 0.1 mm and then wound by cooling with a cooling roll to obtain a single-layer sealing material sheet having a thickness of 0.45 mm.

(Comparative Example 3)

A sealing material sheet was prepared in the same manner as in Comparative Example 2, except that no hydroxide (magnesium hydroxide) was added in the layer A.

&Lt; Total light transmittance of the sealing material sheet >

Using a turbidimeter (NDH2000, manufactured by Nippon Denshoku Kogyo Co., Ltd.), the total light transmittance in the thickness direction of the sealing material sheet was measured based on JIS K7361: 1997. The results obtained are shown in Table 1 below.

&Lt; Evaluation of moisture resistance of solar cell module >

(3.2 mm in thickness), a sealing material sheet, a solar cell element, a sealing material sheet, and a backing protective member were used as the light-receiving-surface-side protection member so as to be a polyester film (0.05 mm) by using the sealing material sheets prepared in the above- Laminated, and heat-treated at 135 캜 for 20 minutes using a vacuum laminator to produce a laminated solar cell module. The moisture resistance test was conducted under the conditions of a high-speed life test apparatus and a condition of standing at 115 캜 and 100% for 240 hours. The maximum power of the solar cell module was measured using a solar simulator according to JIS C8912: 1998. In the evaluation, the value obtained by subtracting the value of the maximum output of the solar cell module after the test from the value of the maximum output of the solar cell module before the test, and dividing the value by the value of the maximum output before the test was regarded as the maximum output change rate.

<Layer Thickness Measurement Method>

A total of 9 points in the width direction (both ends, central portion) and three points in the length direction (both ends, central portion) were used as the thickness measurement samples from the sample of 1 m in the width direction and 1 m in the length direction. The cross section of the film was cut into ultra-thin slices, and observed using a laser microscope VKX-100 manufactured by Keith Corporation, and the thickness of each layer was measured from the cross-sectional photograph.

&Lt; Measurement method of melting point >

The melting point of the resin as the raw material of the sealing material was measured by differential scanning calorimetry (DSC) according to the method of measuring the transition temperature of plastics (JIS K7121: 1987). The obtained results are shown in Table 1.

As is clear from the results shown in Table 1, in the case of using the sealing material sheet of the present invention (Examples), the total light transmittance was high, the maximum output change rate after the moisture resistance heat test of the solar cell module was small, there was.

[Industrial applicability]

According to the present invention, there is provided a sealing material sheet capable of maintaining high power generation performance without deterioration of a solar cell element even when used for a long period under high temperature and high humidity without impairing high transparency, and a solar cell module obtained using the same can do.

10 Sealing sheet
11th floor A
12th floor B
101 Light-receiving surface side sealing material sheet
102 back side sealing sheet
20 solar module
21 transparent protective member
22 solar cell element
23,

Claims (8)

As the sealing material sheet having the layer A and the layer B,
The layer A is a layer containing an ethylene-vinyl acetate copolymer as a main component,
Wherein the layer B is a layer containing a thermoplastic resin other than the ethylene-vinyl acetate copolymer as a main component and further containing a hydroxyl group. The sealing material sheet according to claim 1, wherein the thermoplastic resin as a main component of the layer B is a polyolefin resin. The sealing material sheet according to claim 1 or 2, wherein the acid anhydride is at least one selected from the group consisting of oxides, hydroxides, carbonates, carboxylates, borates, silicates and phosphites of a Group II metal of the periodic table. The sealing material sheet according to any one of claims 1 to 3, wherein the amount of the acidic agent in the layer B is 0.5 parts by mass or less when the thermoplastic resin as the main component of the layer B is 100 parts by mass. The ethylene-vinyl acetate copolymer according to any one of claims 1 to 4, wherein the vinyl acetate content of the ethylene-vinyl acetate copolymer which is the main component of the layer A is 15 to 40% by mass based on 100% by mass of the ethylene- Wherein the sealing material sheet is a sheet. The sealing material sheet according to any one of claims 1 to 5, wherein the thickness of the layer A is 0.1 mm or more and 1.0 mm or less, and the thickness of the layer B is 0.01 mm or more and 1.0 mm or less. The sealing material sheet according to any one of claims 1 to 6, wherein the melting point of the thermoplastic resin as a main component of the layer B is higher than the melting point of the ethylene-vinyl acetate copolymer as a main component of the layer A. A solar cell module obtained by using the sealing material sheet according to any one of claims 1 to 7.

Images