TW201416228A - Sealing sheet and solar cell module obtained using same - Google Patents

Abstract

Provided are: a sealing sheet which keeps high transparency and which can yield a solar cell element that suffers from little deterioration even after long-term use under high-temperature and high-humidity conditions and thus can keep high power generation performance; and a solar cell module using the same. A sealing sheet which comprises a layer (A) and a layer (B), characterized in that: the layer (A) is a layer which comprises an ethylene-vinyl acetate copolymer as the main component; and the layer (B) is a layer which comprises a thermoplastic resin other than ethylene-vinyl acetate copolymers as the main component and which contains an acid acceptor.

Description

Package sheet and solar battery module using same

The present invention relates to a package sheet.

The solar cell module is formed by laminating a package material sheet on both sides of a solar cell element including a semiconductor wafer such as a single crystal germanium or a polycrystalline silicon, and superposing a protective member such as a glass or a back sheet on the underside of the package sheet. Integrator.

Since the solar cell module is exposed to high temperatures, high humidity, ultraviolet rays, and wind and rain, it has been used for a long period of time, and the package material requires weather resistance or heat resistance which is not deteriorated by moisture, ultraviolet rays, or the like. The adhesion of the protective member or the solar cell element, the flexibility of the solar cell element by external impact, and the like. Further, electrical insulation resistance or transparency of the solar cell element is required to be sufficiently obtained.

As the resin which meets the above-mentioned required characteristics at a low cost, an ethylene-vinyl acetate copolymer is mainly used. However, the ethylene-vinyl acetate copolymer generates an acid such as acetic acid due to hydrolysis due to moisture infiltrated into the inside of the module or decomposition by ultraviolet rays, and the acid causes deterioration of the solar cell element or corrosion of the electrode. Module power generation performance is reduced.

Patent Document 1 proposes an average particle diameter of 5 μm or less. The acid acceptor particles are dispersed in the ethylene-vinyl acetate copolymer to reduce the free acid component in the package.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2005-029588

However, in the package material described in Patent Document 1, since the ethylene-vinyl acetate copolymer layer of the acid generation source is in contact with the solar cell element or the electrode, there is a problem that the solar cell element is prevented from being deteriorated and the electrode corrosion is insufficient.

In view of the problems of the prior art as described above, in the present invention, an object of the present invention is to provide a package sheet and a solar cell module using the same, which does not impair high transparency even at high temperatures. In the case of long-term use under high humidity, the deterioration of the solar cell element is small, and high power generation performance can be maintained.

The present inventors have conducted intensive studies to achieve the above object, and have found that the above problems can be solved by adopting the following configuration.

That is, the package sheet of the present invention is as follows.

A package sheet characterized by a package sheet of layer A and layer B, the layer A being a layer comprising an ethylene-vinyl acetate copolymer as a main component. This layer B is a layer containing an acid acceptor as a main component of a thermoplastic resin other than the ethylene-vinyl acetate copolymer.

According to the present invention, it is an object of the invention to provide a package sheet and a solar cell module using the same, which does not impair high transparency, and deteriorates solar cell elements even in a long-term use under high temperature and high humidity. It is also rare to maintain high power generation performance.

10‧‧‧Package sheet

11‧‧‧A

12‧‧‧Layer B

101‧‧‧Light-emitting side packaging material sheet

102‧‧‧ Back side packaging material sheet

20‧‧‧Solar battery module

21‧‧‧Transparent protective components

22‧‧‧Solar battery components

23‧‧‧Back protection member

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing a cross section of a package sheet of the present invention.

Fig. 2 is a schematic view showing a cross section of a solar cell module using the package sheet of the present invention.

[Formation of the Invention]

The package sheet of the present invention is characterized by having a package sheet of layer A and layer B, the layer A being a layer mainly composed of an ethylene-vinyl acetate copolymer, and the layer B is ethylene-vinyl acetate. A thermoplastic resin other than the copolymer contains, as a main component, a layer of an acid acceptor.

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

<Package Sheet>

Layer A is a layer having an ethylene-vinyl acetate copolymer as a main component. Here, the layer having the ethylene-vinyl acetate copolymer as a main component means that 50% by mass of all the components in the layer is contained in 100% by mass. The above 100% by mass or less of the ethylene-vinyl acetate copolymer. It is important that layer A is based on an ethylene-vinyl acetate copolymer as a main component, and in the case where layer A does not meet the conditions, such a package sheet is assembled into a solar cell module, and damage is caused by external collision. Protects the softness of solar cells and the like. The content of the ethylene-vinyl acetate copolymer in the layer A is preferably 70% by mass or more and 99.5% by mass or less, more preferably 90% by mass or more and 99% by mass or less.

The vinyl acetate content of the ethylene-vinyl acetate copolymer of the main component of the layer A is preferably 15 to 40% by mass when the ethylene-vinyl acetate copolymer is 100% by mass. If the ethylene-vinyl acetate copolymer having a main component of the layer A has a vinyl acetate content of less than 15% by mass, the transparency of the solar cell module is lowered, and the power generation performance of the solar cell module is lowered; 40% by mass, the workability is lowered in the solar cell module manufacturing step. The vinyl acetate-containing copolymer of the main component of the layer A preferably has a vinyl acetate content of 20% by mass or more and 35% by mass or less, particularly preferably 25% by mass or more and 33% by mass or less.

Further, 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, in the solar cell module manufacturing step, when the layer is laminated, the solar cell element is broken. When the thickness of the layer A exceeds 1.0 mm, there is a case where the cost is increased. . 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.

Further, it is preferable that the layer A contains an organic peroxide. Layer A contains organic peroxide, in the solar cell module manufacturing steps In the middle, the ethylene-vinyl acetate copolymer in the layer A can be crosslinked by heating the sealing material sheet, and heat resistance, weather resistance, and the like can be expressed.

Although the organic peroxide contained in the layer A is not particularly limited, it is selected in consideration of the temperature at which the package sheet is produced, the heating when the solar cell module is fabricated, the bonding temperature, the storage stability, and the like. . In particular, an organic peroxide having a half-life of 10 hours and a decomposition temperature of 70 ° C or more is preferred. Examples of such an organic peroxide include dicumyl peroxide, 2,5-dihydroperoxy-2,5-dimethylhexane, and 2,5-dimethyl-2,5. - bis (tertiary butyl peroxy) hexane, 2,5-dimethyl-2,5-bis(tertiary butylperoxy)hexane-3-di(tertiary butyl) peroxide, Di(tributyl) peroxide, tributyl butyl peroxyphenyl, 2,5-dimethyl-2,5-di(tri-butylperoxy)hexane, α,α'- Bis(tris-butylperoxyisopropyl)benzene, n-butyl-4,4-bis(tertiary butylperoxy)valerate, 2,2-bis(tertiary butylperoxy)butane 1,1-bis(tri-butylperoxy)cyclohexane, 1,1-bis(tertiary butylperoxy)-3,3,5-trimethylcyclohexane, tert-butyl Oxybenzoic acid ester, benzammonium peroxide, tertiary butyl peroxyacetate, methyl ethyl ketone peroxide, 2,5-dimethyl-2,5-bis (tributyl) Oxygen)-3,3,5-trimethylcyclohexane, 1,1-bis(tri-butylperoxy)cyclohexane, methyl ethyl ketone peroxide, 2,5-dimethylhexyl -2,5-diperoxybenzoate, tertiary butyl hydroperoxide, hydroperoxide pair Menchhane, p-chlorobenzylidene peroxide, hydroxyheptyl peroxide, chlorhexidine peroxide, octyl sulfoxide, ruthenium peroxide, ruthenium peroxide, cumene peroxyoctanoate , peroxy succinic acid, tertiary butyl peroxy maleic acid, ethoxylated oxime, tertiary butyl peroxy (2-ethylhexanoate), m-toluene peroxide, tertiary butyl Base peroxyisobutyrate, peroxy-2,4-dichlorobenzylidene, tert-butylperoxyisopropyl carbonate, tert-butylperoxy-2-ethylhexyl carbonate, 2 , 5-dimethyl-2,5-bis(benzylidene peroxy)hexane, tertiary butyl peroxyisophthalate, tertiary butyl peroxybenzoate, 1,1-double (tertiary pentylperoxy)cyclohexane, ethyl-3,3-di(tri-butylperoxy)butyrate, and the like. These organic peroxides may be contained in combination of two or more kinds.

The content of the layer A of the organic peroxide is preferably from 0.1 to 5 parts by mass, more preferably from 0.1 to 3 parts by mass, based on 100 parts by weight of the ethylene-vinyl acetate copolymer in the layer A. It is preferably 0.1 to 2 parts by mass. With respect to 100 parts by weight of the ethylene-vinyl acetate copolymer in the layer A, if the content of the organic peroxide in the layer A is less than 0.1 part by mass, the ethylene-vinyl acetate copolymer may not be crosslinked. In other cases, even if it contains more than 5 parts by mass, in addition to the low effect of the inclusion, there is a possibility that the undecomposed organic peroxide remains in the layer A and becomes a cause of deterioration year by year.

Further, the layer A preferably further contains a crosslinking assistant. Here, the crosslinking assistant means a polyfunctional monomer having a plurality of unsaturated bonds in the molecule. The polyfunctional monomer having a plurality of unsaturated bonds in the molecule can react with the living radical compound produced by decomposition of the organic peroxide to uniformly and efficiently crosslink the ethylene-vinyl acetate copolymer. Examples of such crosslinking assistants include triallyl isocyanate, triallyl cyanate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and three. [(Meth)acryloyloxyethyl]isocyanate, dimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol ethoxytetra(meth)acrylic acid Ester, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, divinyl benzene, and the like. These crosslinking assistants may be used alone or in combination of two or more.

Further, in the layer A, it is more preferable to further contain an ultraviolet absorber. The ultraviolet absorbing agent absorbs harmful ultraviolet rays in the illuminating light and converts it into harmless heat energy in the molecule to prevent the active species which are initiated by photodegradation in the polymer from being excited. Known things can be used as the ultraviolet absorber. For example, a benzophenone type, a benzotriazole type, or a third can be used. System, salicylic acid, cyanoacrylate, and the like. One type of these may be used, or two or more types may be used in combination.

From the viewpoint of the ultraviolet absorbing effect and the coloring of the ultraviolet absorbing agent itself, among these ultraviolet absorbing agents, a benzophenone-based ultraviolet absorbing agent is preferable.

The content of the ultraviolet absorber in the layer A is preferably from 0.1 to 3 parts by mass, more preferably from 0.1 to 2.0 parts by mass, per 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 effect is low because it is low, and if it is more than 3 parts by mass, it tends to be colored because it tends to be colored.

Further, it is preferable that the layer A contains a photostabilizer. Light stabilizers are those that capture free radical species that are harmful to the polymer so that no new free radicals are produced. As the light stabilizer, a hindered amine light stabilizer is preferably used.

Examples of the hindered amine light stabilizer include bis(2,2,6,6-tetramethyl-1-(octyloxy)-4-piperidyl) sebacate and hydroperoxide-1. , 70% by mass of the reaction product of 1-dimethylethyl and octane and 30% by mass of polypropylene, bis(1,2,2,6,6-pentamethyl-4-piperidinyl)[[ 3,5-double (1,1- Dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate and A mixture of methyl-1,2,2,6,6-pentamethyl-4-piperidinyl sebacate, and the like. The above-mentioned hindered amine-based light stabilizer may be used singly or in combination of two or more.

Among these, as the hindered amine light stabilizer, bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate and methyl-1,2 are preferably used. , a mixture of 2,6,6-pentamethyl-4-piperidinyl sebacate, and methyl-4-piperidinyl sebacate, bis(2,2,6,6-tetramethyl 4-piperidinyl) sebacate. Further, the hindered amine light stabilizer is preferably one having a melting point of 60 ° C or higher.

The content of the hindered amine-based light stabilizer in the layer A is preferably from 0.1 to 3.0 parts by mass, more preferably from 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 hindered amine light stabilizer in the layer A is less than 0.1 part by mass, the effect of stabilization is insufficient; even if it contains more than 3.0 parts by mass, it is only the main cause of coloring or cost increase.

Further, in the layer A, an antioxidant, a flame retardant, a flame retardant auxiliary, a plasticizer, a lubricant or the like which is a known additive may be contained as long as it does not impair the effects of the present invention.

The layer B is a layer containing an acid acceptor as a main component and a thermoplastic resin other than the ethylene-vinyl acetate copolymer.

Here, the thermoplastic resin other than the ethylene-vinyl acetate copolymer as a main component means that the ethylene-vinyl acetate copolymer is contained in an amount of 50% by mass or more and 100% by mass or less based on 100% by mass of all the components in the layer. A thermoplastic resin other than the one. The important thing is that layer B is based on B. A thermoplastic resin other than the olefin-vinyl acetate copolymer is used as a main component, and if an ethylene-vinyl acetate copolymer is used in the layer B, such a package sheet is assembled into a solar cell module, since the layer B and the solar cell Contact between the element and the electrode may cause problems such as deterioration of the solar cell element and corrosion of the electrode. The content of the thermoplastic resin other than the ethylene-vinyl acetate copolymer in the layer B is preferably 70% by mass or more and 99.5% by mass or less, more preferably 90% by mass or more and 99.5% by mass or less.

Examples of the thermoplastic resin other than the ethylene-vinyl acetate copolymer as the main component of the layer B include polyester, polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, and the like. Styrene resin, polyolefin resin such as polyethylene or polypropylene, polycarbonate, polyamide, polyether, polyurethane, polyphenylene sulfide, polyester decylamine, polyether ester, Polyvinyl chloride, polymethacrylate, modified polyphenylene ether, polyarylate, polyfluorene, polyetherimine, polyamidimide, polyimine and copolymerization of these as main components Things. In addition, the thermoplastic resin can be used alone or in combination of two or more.

The thermoplastic resin other than the ethylene-vinyl acetate copolymer which is a main component of the layer B is preferably a polyolefin resin from the viewpoint of reducing damage to the solar cell element in the lamination step or improving transparency and productivity. Good for polyethylene. Among them, the ultra-low density polyethylene and the linear low-density polyethylene having a density of 0.900 g/cm ³ or less are preferably 0.890 g/cm ³ or less, more preferably 0.870 to 0.885 g/cm ³ .

Further, the melting point (set to Tmb) of the thermoplastic resin other than the ethylene-vinyl acetate copolymer as the main component of the layer B is preferably the layer A The melting point (set to Tma) of the ethylene-vinyl acetate copolymer of the main component is high. That is, it is preferable to comply with Tma<Tmb. More preferably, it conforms to the Tma+10≦Tmb type, and more preferably conforms to the Tma+10≦Tmb≦Tma+80 type. If the melting point of the thermoplastic resin other than the ethylene-vinyl acetate copolymer of the main component of the layer B is below the melting point of the ethylene-vinyl acetate copolymer of the main component of the layer A (that is, if it is Tma≧Tmb), then In the solar cell module manufacturing step, the layer B connected to the solar cell element is melted to make the thickness of the layer B uneven, and since the layer A is directly connected to the solar cell element, the acid acceptor contained in the layer B is reduced. effect.

As described above, the layer B contains a thermoplastic resin other than the ethylene-vinyl acetate copolymer as a main component and further contains a layer of an acid acceptor. The acid acceptor used herein is generally not particularly limited as long as it has a function of absorbing or neutralizing an acid, and any compound can be used.

Examples of the acid acceptor contained in the layer B include an oxide of a metal of the group (II) of the periodic table, a hydroxide of a metal of the group (II) of the periodic table, a carbonate of a metal of the group (II) of the periodic table, and a period. a carboxylate of a metal of Group (II), a borate of a metal of Group (II) of the periodic table, a citrate of a metal of Group (II) of the periodic table, a phosphite of a metal of Group (II) of the periodic table, An oxide of a metal of group (IV) of the periodic table, an alkali carbonate of a metal of group (IV) of the periodic table, an alkali carboxylate of a metal of group (IV) of the periodic table, and a metal of group (IV) of the periodic table An alkali phosphite, an alkali sulfite of a metal of Group (IV) of the periodic table, a Li-Al-based inclusion compound represented by the formula (1), and a Li- represented by the formula (2) The Al system encapsulates the compound.

Formula (1): Mg _x Zn _y Al _z (OH) _2(x+y)+3z-2 CO ₃ ‧wH ₂ O (1) (x and y represent an integer of 0 to 10, but x+ y = 1 to 10, z represents an integer of 1 to 5, and w represents an integer of 0 to 10.) The synthetic hydrotalcite represented by the formula; (2): [Al ₂ Li(OH) ₆ ] _n X ‧mH ₂ O (2) (wherein X is an inorganic or organic anion, n is an valence of an anion X, and m is an integer of 3 or less).

Specific examples of such an acid acceptor include magnesium oxide, magnesium hydroxide, barium hydroxide, magnesium carbonate, barium carbonate, quicklime, slaked lime, calcium carbonate, calcium citrate, calcium stearate, and zinc stearate. , calcium phthalate, calcium phosphite, tin oxide, alkaline tin phosphite, and the like.

In addition, as the Li-Al-based inclusion compound represented by the formula (1), for example, Mg ₃ ZnAl ₂ (OH) ₁₂ CO ₃ ‧ wH ₂ O or the like can be given.

The Li-Al-based inclusion compound represented by the formula (2) may, for example, be [Al ₂ Li(OH) ₆ ] ₂ X‧H ₂ O or the like.

Further, examples of the anion species of the Li-Al-based inclusion compound include carbonic acid, sulfuric acid, perchloric acid, phosphoric acid oxyacid, acetic acid, propionic acid, adipic acid, benzoic acid, phthalic acid, and para-benzene. Dicarboxylic acid, maleic acid, fumaric acid, succinic acid, p-hydroxybenzoic acid, salicylic acid, picric acid, and the like. Further, these acid acceptors can be used singly or in combination of two or more kinds.

Among such acid acceptors, the acid acceptor in layer B is preferably an oxide, hydroxide or carbon selected from the group consisting of metals of group (II) of the periodic table. At least one of the group consisting of an acid salt, a carboxylate, a borate, a citrate, and a phosphite.

Further, when the acid acceptor is a particle, the average particle diameter of the acid acceptor is not particularly limited, but a preferred upper limit is an average particle diameter of 5 μm or less. When the average particle diameter of the acid acceptor is larger than 5 μm, the transparency of the encapsulating material may be lowered, and the solar cell element may be prevented from entering the sunlight.

In the acid acceptor of the layer B, when the thermoplastic resin of the main component in the layer B is 100 parts by mass, the content of the acid acceptor in the layer B is preferably 0.5 parts by mass or less, more preferably 0.01 mass%. More than 0.3 parts by mass or less. When the amount of the acid acceptor in the layer B is more than 0.5 part by mass, the transparency of the package sheet is lowered when the amount of the thermoplastic resin in the layer B is 100 parts by mass. A situation in which sunlight is incident on a solar cell element.

Further, 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. If the thickness of the layer B is less than 0.01 mm, the effect of absorbing or neutralizing the acid is insufficient, and if it exceeds 1.0 mm, the transparency is lowered and the sunlight is prevented from entering the solar cell element.

Further, in the layer B, a crosslinking agent, a crosslinking assistant, an antioxidant, a flame retardant, a flame retardant, a plasticizer, which are known additives, may be contained as necessary within the range which does not impair the effects of the present invention. Agents, lubricants, crystal nucleating agents, and the like.

Next, a film forming method of the package sheet of the present invention will be described.

The package sheet of the present invention is formed by a conventional molding method using a T-die extruder, a calender molding machine, a blow molding machine, or the like, regardless of the number of layers for the purpose of laminating, or by separately forming each layer of sheets. Can be manufactured. In other words, the method of laminating the package sheet can be carried out by a so-called multilayer molding, or can be an extrusion lamination method in which each layer is formed by a molding machine.

Further, in the package sheet of the present invention, it is preferable to perform embossing on one side or both sides from the viewpoint of work at the time of production of the solar battery module or suction. Also, the embossing process is carried out by a conventional method. For example, a method of embossing by a forming roll immediately after being extruded from a T die or the like, or a method of embossing after reheating a sheet extruded from a T die or the like is performed.

Next, a description will be given of a solar cell module using the package sheet of the present invention. In addition, the package sheet of the present invention is used as a package sheet (hereinafter simply referred to as a light-receiving side-side package sheet) disposed on the light-receiving surface side in the solar cell module, or as a package sheet disposed on the back side. It is possible to use.

The solar battery module 20 shown in FIG. 2 includes a transparent protective member 21 fixed by the light-receiving surface side sealing material sheet 101 and a back surface protective member 23 fixed by the back side packaging material sheet 102, and is packaged on the light receiving surface side. The solar cell element 22 is disposed between the material sheet 101 and the back side package sheet 102, and the light receiving surface side of the solar cell element 22 is disposed toward the transparent protective member 21 side.

The solar cell module 20 of the present invention obtained by using the package sheet of the present invention is manufactured in the following manner.

A layered body is formed in which the layer B 12 of the light-receiving side-side package sheet 101 is on the side of the solar cell element 22 and the layer B 12 of the back-side package sheet 102 is on the side of the solar cell element 22, and the solar cell element 22 is formed. The light-receiving surface side sealing material sheet 101 and the back side packaging material sheet 102 are disposed on the outer side, and the transparent protective member 21 and the back surface protective member 23 are disposed on both sides of the outer surface of the light receiving surface side sealing material sheet 101 and the back side packaging material sheet 102. to make.

Next, the laminate is heated by a vacuum laminator or the like at a temperature of 130 to 180 ° C for 2 to 15 minutes, followed by heating at a pressurization pressure of 0.1 to 1.5 kg/cm ² and a pressurization time of 8 to 45 minutes. The solar cell module of the present invention obtained by using the package sheet of the present invention can be produced by pressurization and pressure bonding. The temperature or time of heating can be moderately changed depending on the composition or thickness of the package sheet.

[Examples]

Hereinafter, the present invention will be specifically described by way of examples and comparative examples.

(Example 1)

A 2-layer co-extrusion apparatus is prepared which connects two extruders to a T-die through a feed block; as a layer A for forming, a resin composition is supplied to the two seats In the extruder, the resin composition comprises 100 parts by mass of an ethylene-vinyl acetate copolymer (vinyl acetate content of 28% by mass, melting point of 71 ° C), and 0.5 parts by mass of a crosslinking agent. 2,5-Dimethyl-2,5-di(tri-butylperoxy)hexane, 0.2 parts by mass of γ-methylpropenyloxy group as a decane coupling agent for improving adhesion to a glass substrate (methacryloxy)propyltrimethoxydecane, 0.1 2 parts by mass of 2,2'-dihydroxy-4,4'-bis(hydroxymethyl)benzophenone as a UV absorber, and 0.3 parts by mass of double (1, 2, 2, 6 as a light stabilizer) , 6-pentamethyl-4-piperidinyl) sebacate.

As a layer B, a resin composition containing 100 parts by mass of ultra low density polyethylene (melting point 115 ° C) and 0.3 parts by mass of magnesium hydroxide as an acid acceptor was supplied to the other seat.

Next, the resin composition was melt-kneaded at 120 ° C by two respective extruders, and the resin composition in a molten state was supplied to the feeding member, and the layer A was placed by the T-die disposed at the tip end of the feeding member. The package sheet 10 was formed by co-extrusion so that the sheet thickness became 0.4 mm and the sheet thickness of the layer B was 0.05 mm. Then, the package sheet of the molten state which has just been coextruded by the T die is supplied to the intermediate between the embossing roll and the rubber roll disposed opposite to the embossing roll, and the embossing roll is pressed against the molten state. On the layer A side of the material sheet, an embossing process having a depth of 0.1 mm was applied to the surface of the layer A of the package sheet, and then a two-layer package sheet having a thickness of 0.45 mm was obtained by winding on a cooling roll while being cooled.

(Example 2)

A package sheet was produced in the same manner as in Example 1 except that the amount of the acid acceptor (magnesium hydroxide) added to the layer B was 1.0 part by mass.

(Example 3)

A package sheet was produced in the same manner as in Example 1 except that the type of the acid acceptor of the layer B was changed from magnesium hydroxide to calcium phosphite.

(Example 4)

A package sheet was produced in the same manner as in Example 1 except that the amount of the acid acceptor (magnesium hydroxide) added to the layer B was 0.5 parts by mass.

(Example 5)

A package sheet was produced in the same manner as in Example 1 except that the ultra-low-density polyethylene (melting point: 115 ° C) of the main component of layer B was changed to a linear low-density polyethylene (melting point: 68 ° C).

(Comparative Example 1)

A package sheet was produced in the same manner as in Example 1 except that the acid acceptor (magnesium hydroxide) of the layer B was not added.

(Comparative Example 2)

A single-layer extrusion apparatus was prepared, which supplied a resin composition comprising 100 parts by mass of an ethylene-vinyl acetate copolymer (vinyl acetate content of 28% by mass) and 0.5 parts by mass of a crosslinking agent 2, 5-Dimethyl-2,5-di(tri-butylperoxy)hexane, 0.2 parts by mass of γ-methacryloxypropyl group as a decane coupling agent for improving adhesion to a glass substrate Trimethoxy decane, 0.1 parts by mass of 2,2'-dihydroxy-4,4'-bis(hydroxymethyl)benzophenone as a UV absorber, and 0.3 parts by mass of a double as a light stabilizer , 2,2,6,6-pentamethyl-4-piperidinyl) sebacate, and 0.3 parts by mass of magnesium hydroxide as an acid acceptor.

Next, the resin composition was melt-kneaded at 120 ° C, and the resin composition in a molten state was supplied to a T die, and the thickness of the sheet was extruded to 0.45 mm to form a film of the package. Then, the package sheet in a molten state which has just been coextruded from the T die is supplied to the intermediate portion of the embossing roll and the rubber roll disposed opposite to the embossing roll, and the embossing roll is pressed against the packaged material in a molten state. On the layer A side of the sheet, after embossing with a depth of 0.1 mm on the surface of the layer A of the package sheet, a single-layer package sheet having a thickness of 0.45 mm was obtained by winding on one side of the cooling roll while cooling.

(Comparative Example 3)

A package sheet was produced in the same manner as in Comparative Example 2 except that the acid acceptor (magnesium hydroxide) of the layer A was not added.

<Full light transmittance of packaging sheet>

The total light transmittance in the thickness direction of the package sheet was measured using a turbidimeter (NDH2000, manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K7361:1997. The results obtained are shown in Table 1.

<Solid heat and humidity evaluation of solar cell modules>

Using the package sheet produced in the above-described examples and the comparative examples, a glass sheet (thickness: 3.2 mm) as a light-receiving surface side protective member, a package sheet, a solar cell element, a package sheet, and the like were laminated. A polyester film (0.05 mm) as a back surface protective member was heat-treated at 135 ° C for 20 minutes by using a vacuum laminator to prepare a solar cell module integrated by lamination. The moisture-resistant heat test was carried out using a high-acceleration life test apparatus under the conditions of standing at 150 ° C for 100% in an environment of 240 hours. The maximum output of the solar cell module was measured in accordance with JIS C8912:1998 using a sunlight simulator. The evaluation is based on the maximum output value of the solar cell module before the test, minus the maximum output value of the solar cell module after the test, and dividing the value by the maximum output value before the test as the maximum output change rate.

<Method for measuring layer thickness>

A sample having a length of 1 m in the width direction and a length of 1 m was used as a thickness measurement sample by combining a total of three points in the width direction (both end portions, center portion) and three in the longitudinal direction (both end portions and center portion). . Cut the section of the film into ultra-thin sections, using the Keyence laser microscope VKX-100 It was observed that the thickness of each layer was measured from the photograph of the cross section.

<Method for measuring melting point>

The method for measuring the melting point of the resin of the packaging material is carried out by a differential scanning calorimeter (DSC) according to the method for measuring the transfer temperature of the plastic (JISK7121: 1987). The results obtained are shown in Table 1.

From the results shown in Table 1, it is clear that the case of using the package sheet of the present invention (Example) is high in total light transmittance, and the maximum output change rate after the heat and humidity test of the solar cell module is small. , maintaining high power generation performance.

[Industrial availability]

According to the present invention, it is possible to provide a package material sheet and a solar battery module using the same, which does not impair high transparency, and the solar battery element is not used even in a long-term use under high temperature and high humidity. It will deteriorate and maintain high power generation performance.

10‧‧‧Package sheet

11‧‧‧A

12‧‧‧Layer B

Claims (8)

A package material sheet characterized by having a package sheet of layer A and layer B, the layer A being a layer mainly composed of an ethylene-vinyl acetate copolymer, the layer B being made of an ethylene-vinyl acetate copolymer The thermoplastic resin contains, as a main component, a layer of an acid acceptor. The package sheet according to claim 1, wherein the thermoplastic resin of the main component of the layer B is a polyolefin resin. The package sheet of claim 1 or 2, wherein the acid accepting system is selected from the group consisting of oxides, hydroxides, carbonates, carboxylates, borates, citrates, and salts of metals of Group (II) of the Periodic Table; At least one of the group of phosphites. The package sheet according to any one of claims 1 to 3, wherein the acid acceptor in the layer B is 0.5 parts by mass or less when the thermoplastic resin of the main component of the layer B is 100 parts by mass. The package sheet according to any one of claims 1 to 4, wherein the ethylene-vinyl acetate copolymer of the layer A main component has a vinyl acetate content, and the ethylene-vinyl acetate copolymer is set to 100% by mass. It is 15 to 40% by mass. The package sheet according to any one of claims 1 to 5, wherein the layer A has a thickness of 0.1 mm or more and 1.0 mm or less, and the layer B has a thickness of 0.01 mm or more and 1.0 mm or less. A package sheet according to any one of claims 1 to 6, wherein the layer B is mainly The melting point of the thermoplastic resin of the component is higher than the melting point of the ethylene-vinyl acetate copolymer of the main component of the layer A. A solar cell module obtained by using the package sheet of any one of claims 1 to 7.