JP2003324211A - Solar battery module and tape for temporary fixing used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tape for temporarily fixing a solar battery wherein such problems are excluded as foaming under a high temperature environment and yellowing deterioration under moisture and a heat environment or ultraviolet ray environment, and to provide a solar battery module which uses the tape and is excellent in durability to a high temperature and secular durability. <P>SOLUTION: In the tape 15 for temporarily fixing a cell 14 for a solar battery, an adhesive layer is formed on base a material composed a of polyethylene resin. The cell 14 is fixed temporarily to an EVA resin film 13A on a surface- side transparent protecting member 11 by using the tape 15. In the solar battery module, a back cover member 12 is capped on the EVA resin film 13A, and they are bonded to each other and collectively formed integrally. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the production of a solar cell module by encapsulating a solar cell using a sealing film between a front transparent protective member and a back protective member. The present invention relates to a temporary fixing tape for temporarily fixing the solar battery cells to each other and the solar battery cell and the sealing film, and a solar battery module using the temporary fixing tape.

[0002]

2. Description of the Related Art In recent years, a solar cell that directly converts sunlight into electric energy has been attracting attention and being developed from the viewpoint of effective use of resources and prevention of environmental pollution.

As shown in FIG. 2, a solar cell generally has an ethylene-vinyl acetate copolymer (EVA) between a front transparent protective member 11 and a rear protective member (back cover material) 12 on the light receiving surface side. The sealing film of the resin films 13A and 13B seals the solar battery cell 14, that is, the power generation element such as silicon.

Such a solar cell module 10 includes a transparent protective member 11 on the front surface such as a glass substrate, EVA for a sealing film, etc.
Film 13A, solar cell 14, EVA for sealing film
It is manufactured by laminating the resin film 13B and the back cover material 12 in this order and adhesively integrating them by heating and melting EVA to crosslink and harden them. In order to prevent distortion or the like of the solar cell 14, FIG. 1 (a) (plan view), (b)
As shown in (a cross-sectional view taken along the line BB of FIG. 1A), the solar battery cells 14 arranged on the EVA resin film 13A on the front-side transparent protective member 11 are temporarily fixed to the tape 15.
Then, as shown in FIG. 1C, the EVA resin film 13B and the back cover material 12 are covered and heated and pressed.

Conventionally, the tape 1 for temporarily fixing the solar cell 14 used for manufacturing the solar cell module 10 is used.
5 includes a fluororesin (polytetrafluoroethylene) base material having an acrylic or silicon adhesive layer formed thereon, or a polyester resin base material having an acrylic or silicon adhesive layer formed thereon. Are used.

[0006]

However, in the conventional temporary fixing tape based on fluororesin or polyester resin, foaming occurs at the interface between the temporary fixing tape 15 and the EVA resin films 13A and 13B in a high temperature environment. There was a problem that. In addition, there is a problem of yellowing deterioration under humid heat or ultraviolet light environment, which impairs high temperature durability and aged durability of the solar cell module.

By manufacturing the solar cell module without using the temporary fixing tape, the problems of foaming and yellowing deterioration due to the temporary fixing tape are solved, but productivity,
From the viewpoint of handleability in the manufacturing process, the use of temporary fixing tape is indispensable.

The present invention solves the above-mentioned conventional problems, and a temporary fixing tape for a solar cell, which is free from problems of foaming in a high temperature environment, yellowing deterioration in a humid heat or ultraviolet environment, and this temporary stop. An object of the present invention is to provide a solar cell module using a tape for use, which has excellent high-temperature durability and long-term durability.

[0009]

The solar cell module of the present invention is a solar cell module in which a solar cell is sealed by using a sealing film between a front surface side transparent protection member and a back surface side protection member. In a solar cell module in which adjacent solar cell cells or solar cell cells and a sealing film are fastened with a temporary tacking tape, the temporary tacking tape is a polyolefin resin substrate. The tape is characterized in that an adhesive layer is formed on the tape.

The temporary fixing tape of the present invention is used for producing a solar cell module by encapsulating a solar cell using a sealing film between the front transparent protective member and the back protective member. In a temporary fixing tape for temporarily fixing the solar cells to each other or the solar cells and the sealing film, the adhesive layer is formed on the polyolefin resin base material. .

The cause of the foaming in the high temperature environment and the yellowing deterioration in the humid heat or the ultraviolet environment in the case of using the conventional temporary fixing tape is that the EVA resin is used during the heating and pressurization in the production of the solar cell module. The adhesiveness, adhesion, and affinity are poor at the interface between the sealing film such as a film and the temporary fixing tape, and a defective adhesion part is generated at the interface. The defective adhesion part is EV in a high temperature environment.
It is a starting point of foaming or yellowing due to the resin compounding agent of the sealing film such as the A resin film or the adhesive component of the temporary fixing tape itself.

The polyolefin resin such as polyethylene resin used as the base material of the temporary fastening tape in the present invention is
A strong sealing film / temporary fastening tape / solar cell for the solar cell module, which is in a molten state when heated and pressed in the manufacturing process of the solar cell module and adheres to the EVA resin or the like that constitutes the sealing film with a very high affinity. / A sealing film interface can be formed.

Therefore, in a high temperature environment, there is no starting point of foaming or yellowing due to the internal components of the sealing film or the pressure-sensitive adhesive layer, and foaming or yellowing can be prevented.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below.

First, the temporary fixing tape of the present invention will be described.

The temporary fixing tape of the present invention comprises a base material made of a polyolefin resin such as polyethylene resin and an adhesive layer formed on the base material.

The thickness of this polyolefin resin substrate is
The thickness may be the same as the thickness of the base material of a normal temporary fixing tape, and is generally about 10 to 1000 μm. If the thickness of the polyolefin resin substrate is less than 10 μm, sufficient strength cannot be obtained, and if it exceeds 1000 μm, the thickness of the temporary fastening tape becomes a problem during the production of the solar cell module.

The pressure-sensitive adhesive layer formed on the base material made of a polyolefin resin is made of an acrylic-based or silicon-based pressure-sensitive adhesive, preferably an acrylic-based pressure-sensitive adhesive, at 1 × 10 ² to 1 × 10 ⁵ nm.
It is preferable that it is formed to a thickness of a certain degree.

The solar cell module of the present invention has the same structure as the conventional solar cell module except that it is manufactured using such a temporary fixing tape.
As shown in (a) and (b), the solar cell 14 is formed on the EVA resin film 13A on the front transparent protective member 11.
After arranging the
4 is temporarily fixed to the EVA resin film 13A, and the adjacent solar cell cells 14, 14 are temporarily fixed to each other.
5 temporarily, and then EVA as shown in FIG. 1 (c).
The solar battery cell 1 is formed by covering the resin film 13B and the back cover material 12 and applying heat and pressure to bond and integrate them.
It is manufactured by sealing 4.

This heating and pressurization is applied to the front side transparent protective member 1.
1, EVA resin film 13A, temporary fixing tape 15
Temporarily fixed solar cell 14, EVA resin film 1
3B and the back cover material 12 laminated body is a non-breathable bag.
After degassing the inside of the bag by putting it in a bag, for example, 50 to 17
Evacuate the bag by vacuuming at 0 ° C for 1-10 minutes,
After setting the internal pressure of the bag to about 0 MPa, 50 to 170 ° C.,
Applied pressure 1.013 × 10 ^-2~ 2.026 x 10^-1M
It can be performed by heating and pressuring at Pa for 1 to 30 minutes.
Wear.

A glass plate having a thickness of about 1 to 5 mm, a highly functional laminated film having a thickness of about 10 to 200 μm, or the like can be used as the front side protective member 11 constituting the solar cell module.

EVA resin film 13 is used as the sealing film.
In addition to A and 13, PVA-based resins and other resin films may be used, but EVA-based resin films are particularly suitable as the sealing film in terms of adhesiveness, water resistance and the like.

EV of EVA resin films 13A and 13B
The A resin has a vinyl acetate content of 5 to 50% by weight,
Preferably, 15 to 40% by weight is suitably used. If the vinyl acetate content is less than 5% by weight, there is a problem in weather resistance and transparency, and if it exceeds 40% by weight, mechanical properties are remarkably deteriorated and film formation becomes difficult, and blocking between sheets or films is blocked. Occurs.

The EVA resin composition for the sealing film is preferably blended with a crosslinking agent for improving the weather resistance so as to have a crosslinked structure. As the crosslinking agent, a radical at 100 ° C. or higher is generally used. An organic peroxide that generates is used, and in particular, in consideration of the stability at the time of compounding, those having a decomposition temperature of 70 hours or more with a half-life of 10 hours are preferable. Examples of such an organic peroxide include 2,5-dimethylhexane; 2,5-dihydroperoxide; 2,5-
Dimethyl-2,5-di (t-butylperoxy) hexane; 3-di-t-butylperoxide; t-dicumyl peroxide; 2,5-dimethyl-2,5-di (t-
Butylperoxy) hexyne; dicumyl peroxide; α, α′-bis (t-butylperoxyisopropyl) benzene; n-butyl-4,4-bis (t-butylperoxy) butane; 2,2-bis (T-Butylperoxy) butane; 1,1-bis (t-butylperoxy)
Cyclohexane; 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane; t-butylperoxybenzoate; benzoyl peroxide and the like can be used. The compounding amount of these organic peroxides is generally 5 parts by weight or less, preferably 1 to 3 parts by weight, based on 100 parts by weight of the EVA resin.

A silane coupling agent can be added to the EVA resin for the purpose of improving the adhesive strength. Known silane coupling agents used for this purpose, for example, γ-chloropropyltrimethoxysilane; vinyltrichlorosilane; vinyltriethoxysilane; vinyl-tris- (β-methoxyethoxy) silane; γ-
Methacryloxypropyltrimethoxysilane; β-
(3,4-Ethoxycyclohexyl) ethyltrimethoxysilane; γ-glycidoxypropyltrimethoxysilane; vinyltriacetoxysilane; γ-mercaptopropyltrimethoxysilane; γ-aminopropyltrimethoxysilane; N-β- (amino Ethyl) -γ-aminopropyltrimethoxysilane and the like can be mentioned. The compounding amount of these silane coupling agents is generally EVA.
The amount is 5 parts by weight or less, preferably 0.1 to 2 parts by weight, based on 100 parts by weight of the resin.

Furthermore, by improving the gel fraction of EVA resin,
A cross-linking aid can be added to the EVA resin in order to improve durability. Known crosslinking aids for this purpose include triallyl isocyanurate; trifunctional crosslinking aids such as triallyl isocyanate, and N
A monofunctional crosslinking aid such as K ester can also be used. The amount of these cross-linking aids to be added is generally EVA resin 1
10 parts by weight or less with respect to 00 parts by weight, preferably 1 to 5
Parts by weight.

Further, for the purpose of improving the stability of the EVA resin, hydroquinone, hydroquinone monomethyl ether, p-benzoquinone, methylhydroquinone and the like can be added, and the compounding amount thereof is generally 100 parts by weight of the EVA resin. It is 5 parts by weight or less.

Further, if necessary, in addition to the above, a colorant, an ultraviolet absorber, an antiaging agent, a discoloration preventing agent, etc. can be added. Examples of colorants include inorganic pigments such as metal oxides and powders, and organic pigments such as azo-based, phthalocyanine-based, azi-based, acidic or basic dye-based lakes. Examples of the ultraviolet absorber include 2-hydroxy-4-octoxybenzophenone; benzophenone compounds such as 2-hydroxy-4-methoxy-5-sulfobenzophenone; 2- (2′-hydroxy-5-methylphenyl) benzotriazole and the like. Benzotriazoles; phenyl salsylates; pt-
There are hindered amines such as butylphenyl salsylate. As anti-aging agents, amine-based; phenol-based;
Bisphenyl type; hindered amine type, for example, di-t-butyl-p-cresol; bis (2,2,6,6)
-Tetramethyl-4-piperazyl) sebacate and the like.

As the solar cell 14, single crystal Si is used.
A so-called bulk solar cell, which uses a polycrystalline silicon or the like, a Si-based thin film, a II-VI compound (CdTe), a chalcopyrite thin film (CIS), an organic semiconductor, and other various solar battery cells can be used.

The back cover material 12 is not particularly limited, but preferably includes one formed by laminating two heat-resistant and weather-resistant films with a moisture-proof film interposed therebetween.

The moisture-proof film of the back cover material 12 is for preventing the infiltration of moisture from the back surface of the solar cell module, and is formed by the CVD (chemical vapor deposition) or PVD (reactive vapor deposition) method on the base film. A film formed by forming a vapor-deposited film of an inorganic oxide containing silicon oxide as a main component as a moisture-proof layer is preferably used.

Aluminum oxide and silicon oxide are used as the inorganic oxide constituting the vapor-deposited film of the inorganic oxide as the moisture-proof layer, and silicon oxide is particularly preferable because of its excellent durability under wet heat conditions. is there.

The composition of the silicon oxide vapor deposition film is SiO.
Although it is generally close, SiO _xAnd x is less than 1.7
In the endurance test and the like, the water vapor permeability gradually decreases, and x = 1.
Those exceeding 9 are disadvantageous in terms of productivity and cost.
Therefore, SiO of the silicon oxide vapor deposition film as the moisture-proof layer_xset
It is desirable that the composition is x = 1.7 to 1.9.

If the thickness of this vapor-deposited film is too thin, sufficient moisture resistance cannot be obtained, and if it is too thick, no further improvement effect of moisture resistance can be obtained, but rather cracks easily occur and moisture resistance is poor. This film thickness is 100 because it may decrease.
It is preferably set to 500 Å, particularly 200 to 400 Å.

On the other hand, the substrate film that serves as a support for the moisture-proof film is not particularly limited as long as it is a heat-resistant film that can withstand the heat and pressure conditions during the production of the solar cell module, but is generally not limited. , Polytetrafluoroethylene (PTFE), 4-fluoroethylene-perchloroalkoxy copolymer (PFA), 4-fluoroethylene-6-fluoropropylene copolymer (FEP), 2-ethylene-4
-Fluororesin copolymer (ETFE), poly 3-fluoroethylene chloride (PCTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF) and other fluororesin films, and polyethylene terephthalate (PE)
Various resin films of polyester such as T), polycarbonate, polymethylmethacrylate (PMMA), polyamide and the like can be used. This base film may contain two or more of these resins, or may be a laminated film of two or more films. If necessary, various additives such as pigments and ultraviolet absorbers may be impregnated, coated or kneaded on the base film.

The thickness of such a base film is preferably about 5 to 200 μm from the viewpoint of durability, handleability, thinning and the like.

The heat-resistant and weather-resistant film that constitutes the back cover material 12 by laminating and integrating such a moisture-proof film is used for protecting the moisture-proof film and improving workability in manufacturing a solar cell module. It is provided for the purpose of withstanding the heat and pressure conditions during the production of solar cell modules,
Especially as a heat resistant and weather resistant film on the side opposite to the sealing film,
Since it becomes the outermost layer when the solar cell module is assembled, it is desired that it does not deteriorate even under long-term outdoor exposure conditions, but the materials exemplified above as the material of the base film can be usually used. This heat-resistant and weather-resistant film may also contain two or more kinds of the above-mentioned resins, like the above-mentioned base film, or may be a laminated film of two or more films. If necessary, various additives such as pigments, UV absorbers, coupling agents and the like may be impregnated, coated or kneaded on the heat and weather resistant film.

The color of the heat-resistant and weather-resistant film is not particularly limited, but a white color is preferable for improving power generation efficiency, and a black color or a dark color of each color is used for improving the appearance when installed in a house or the like. Color is used.

The thickness of such a heat-resistant and weather-resistant film is 5 to 20 from the viewpoint of durability, handleability, thinning, and the like.
It is preferably about 0 μm.

The two heat and weather resistant films constituting the back cover material 12 are not necessarily made of the same material, but may be made of different materials.

In particular, it is preferable to use a fluororesin film having excellent weather resistance for the heat and weather resistant film on the outer surface side of the solar cell module, and a pigment and the like for the heat and weather resistant film on the inner surface side. It is preferable to use a film which has been kneaded to give reflection performance.

Practically, the back cover material 12 as described above is bonded and integrated by a method such as a dry lamination method or a heat press method with an adhesive between a heat resistant and weather resistant film and a moisture proof film. Manufactured by.

As an adhesive used for laminating such a film, a urethane adhesive such as a polyester or polyether adhesive is generally used. The polyether adhesive has a low initial adhesive strength and heat resistance. Inferior to
The polyester type has a drawback that it has good heat resistance but low wet heat resistance. This is because these adhesive ingredients
This is because the skeleton contains —O— or —C═O—O— chain.

In order to solve this drawback, a hydrogenated polybutadiene obtained by bonding a heat-resistant and weather-resistant film and a moisture-proof film with a butadiene skeleton as a main chain and hydrogenated to prevent deterioration due to cleavage of a double bond. It is preferable to use a modified urethane adhesive. The thing is, the main chain is -CH ₂ -
The adhesion durability is greatly improved compared to the conventional products.

Such a back cover material 12 is made of EVA.
It may be a sealing film also serving as a back cover material, which is previously bonded and integrated with a sealing film such as the film 13B.

[0046]

EXAMPLES The present invention will be described more specifically with reference to Examples and Comparative Examples below.

Example 1, Comparative Examples 1 to 4 A solar cell module was manufactured by the method shown in FIG. 1 using the tapes shown in Table 1 as the temporary fixing tape. Further, a laminated glass type sample for measuring yellowing degree shown in FIG. 3 was prepared.

Front side protective member 11 of solar cell module
Is a glass plate with a thickness of 3.5 mm, and is an EV for sealing
EVA with a thickness of 600 μm as the A resin film 13A
A film was used.

As the back cover material 12, "Tedlar film" manufactured by Teijin DuPont (thickness 38 μm) /
EVA for sealing using a three-layer laminated film of aluminum foil (thickness 40 μm) / “Tedlar film” (thickness 38 μm)
A film having a thickness of 400 μm was used as the film 13B.

The back cover material 12, the sealing EVA resin film 13B, the front side protection member 11 and the sealing EVA resin film 13A are all 810 mm in width and 1250 in length.
150 mm in width × 150 mm in length for solar cell (silicon power generation element) 14 having a size of mm and on the surface side protection member 11 and the EVA resin film 13A for sealing.
40 rows in total, 5 rows in the horizontal direction and 8 rows in the vertical direction, are temporarily fixed with the temporary fixing tape 15, and a sealing film that also serves as a back cover material is laid over this and laminated to form a rubber laminate. It was placed in a bag and sealed with a vacuum laminator. The heating and pressing conditions were as follows. [Heating / pressurizing conditions] Temperature: 150 ° C. Pressure: 7.09 × 10 ⁴ Pa Pressurizing time: 5.5 minutes

The laminated glass type sample 4 for measuring the degree of yellowing has a size of 50 mm × 50 m as shown in FIG. 3 (a).
Between two glass plates 1A and 1B with a thickness of mx3mm, 5
The temporary fixing tape 3 is sandwiched between the EVA films 2A and 2B of 0 mm × 50 mm, temperature: 90 ° C., pressure:
It is heated and pressurized at 1.013 × 10 ⁵ Pa and a pressurizing time: 8 minutes, and integrated by EVA2 as shown in FIG. 3 (b).

The obtained solar cell module and the sample for measuring the degree of yellowing were examined for the presence or absence of foaming or yellowing under the following environmental conditions, and the results are shown in Table 1. [Presence or absence of foaming in a high temperature and high humidity environment] The presence or absence of foaming was visually observed after the solar cell module was left in an environment of 85 ° C. and 85% RH for 750 hours. [Yellowness under high temperature and high humidity environment] The degree of yellowing after leaving the sample for yellowing degree measurement under UV irradiation of 85 ° C and 85% RH for 500 hours is represented by YI value (yellowing index). Indicated. [Yellowness under UV environment] The YI value represents the degree of yellowing after the sample for measuring the degree of yellowing was irradiated with UV for 500 hours.

[0053]

[Table 1]

From Table 1, the temporary fixing tape of the present invention has no problems of foaming and yellowing under high temperature and high humidity environment, and yellowing under ultraviolet environment, and has high temperature durability and long-term durability. It can be seen that an excellent solar cell module can be obtained.

[0055]

As described in detail above, the temporary fixing tape of the present invention has a problem of foaming under high temperature environment, yellowing deterioration under high temperature environment or ultraviolet environment between the sealing films of the solar cell module. Therefore, according to the solar cell module of the present invention using such a temporary fixing tape, a high quality solar cell module excellent in high temperature durability and long-term durability is provided.

[Brief description of drawings]

1A and 1B are diagrams showing a method for manufacturing a solar cell module, wherein FIG. 1A is a plan view, FIG. 1B is a cross-sectional view taken along the line BB of FIG. 1A, and FIG. Is a diagram,

FIG. 2 is a cross-sectional view showing the structure of a solar cell module.

FIG. 3 is a cross-sectional view showing a sample for measuring yellowing degree,
(A) figure shows the state before heating and pressurizing, (b) shows the state after heating and pressing.

[Explanation of symbols]

1A, 1B glass plate 2 EVA 2A, 2B EVA film 3 Temporary fastening tape 4 samples 10 solar cell module 11 Front side transparent protective member 12 Back cover material 13A, 13B EVA resin film 14 Solar cell 15 Temporary fastening tape

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4J004 AA10 AA11 AB01 CA04 CC02                       FA05 FA08                 4J040 DF041 EK031 JA09 JB09                       LA07 LA08                 5F051 BA18 EA20 JA02 JA03 JA04                       JA05 JA20

Claims (8)

[Claims] 1. A solar cell module in which solar cells are sealed by using a sealing film between a front surface side transparent protection member and a back surface side protection member, wherein adjacent solar cell cells are adjacent to each other. Alternatively, in the solar cell module in which the solar cell and the sealing film are fastened with a temporary fastening tape, the temporary fastening tape is a tape formed by forming an adhesive layer on a polyolefin resin base material. A solar cell module characterized in that 2. The solar cell module according to claim 1, wherein the polyolefin resin base material is a polyethylene resin base material. 3. The solar cell module according to claim 1 or 2, wherein the adhesive layer of the temporary fixing tape is an acrylic adhesive layer or a silicon adhesive layer. 4. The solar cell module according to any one of claims 1 to 3, wherein the sealing film is formed of an EVA resin composition. 5. The solar cell according to claim 1, wherein the solar cell is fixed to the sealing film laminated on the front transparent protective member with the temporary fixing tape. A solar cell module characterized in that 6. The thickness of the polyolefin resin base material according to claim 1, which is 10 to 100.
0 μm, the pressure-sensitive adhesive layer has a thickness of 1 × 10 ² to 1 × 10 ^5.
The solar cell module is characterized in that it is nm. 7. When manufacturing a solar cell module by encapsulating a solar cell using a sealing film between a front transparent protective member and a back protective member, adjacent solar cells are adjacent to each other. Alternatively, in the temporary fixing tape for temporarily fixing the solar cell and the sealing film, a temporary fixing tape is obtained by forming an adhesive layer on a polyolefin resin base material. 8. The temporary fixing tape according to claim 7, wherein the polyolefin resin base material is a polyethylene resin base material.