KR101318986B1 - Low shrinkable encapsulant sheet for solar cell module with high strength and solar cell module using the same - Google Patents

Abstract

The present invention relates to a low shrinkage encapsulant sheet for a photovoltaic module having a high strength ultra-fine fiber layer and a photovoltaic module using the same. More particularly, the present invention relates to shrinkage of an encapsulant sheet during or after the adhesive integration of an ethylene vinyl acetate sheet. It relates to a low-shrinkable encapsulant sheet for a solar module having a high strength ultra-fine fiber layer that can be prevented and a solar module using the same. To this end, the low shrinkage encapsulant sheet for a solar module having a high strength ultrafine fiber layer according to the present invention is an encapsulant sheet and a fiber layer coated on at least one surface of the encapsulant sheet, and an ultrafine fiber formed by electrospinning. Including an ultra-fine fiber layer made of, the ultra-fine fibers are characterized in that made of polyethylene resin.

Description

LOW SHRINKABLE ENCAPSULANT SHEET FOR SOLAR CELL MODULE WITH HIGH STRENGTH AND SOLAR CELL MODULE USING THE SAME}

The present invention relates to a low shrinkage encapsulant sheet for a photovoltaic module having a high strength ultra-fine fiber layer and a photovoltaic module using the same. More particularly, the present invention relates to shrinkage of an encapsulant sheet during or after the adhesive integration of an ethylene vinyl acetate sheet. It relates to a low-shrinkable encapsulant sheet for a solar module having a high strength ultra-fine fiber layer that can be prevented and a solar module using the same.

Recently, due to the depletion of fossil fuels and environmental pollution, solar cells for directly converting sunlight into electrical energy have been widely used.

The photovoltaic module used in such a solar cell is generally ethylene vinyl acetate between the front side transparent protection member 11 and the back side protection member 12 used as glass, etc., as shown in FIG. 2. It consists of the form which connected many solar cell 14, such as a silicon power generation element, using the surface side sealing material sheet 13A, such as a copolymer (EVA) sheet, and the back side sealing material sheet 13B. It is. Such a solar module has the front side transparent protection member 11, the front side sealing material sheet 13A, the solar cell 14, the back side sealing material sheet 13B, and the back side protection member 12 in order. It is manufactured by laminating | stacking, heat-pressing, and adhesive-integrating an encapsulant sheet.

On the other hand, in order to improve the efficiency of the photovoltaic module, it is preferable to inject light into the solar cell as efficiently as possible and to concentrate the photovoltaic cell, so that the encapsulant for the photovoltaic module has high transparency and adhesiveness. Copolymer (EVA) sheets are commonly used.

However, the conventional method has a problem that the solar cell module is cracked due to the pressure applied when the encapsulant sheet is adhered to the solar cell. In addition, when crosslinking reaction occurs in the state in which deaeration is insufficient, foam | bubble generate | occur | produced in the solar cell module, and it brought about the fall of power generation efficiency and the deterioration of reliability.

In order to improve this problem, Japanese Patent Laid-Open Publication No. 2000-183388 discloses a solar cell module encapsulant sheet having an uneven surface continuously formed by embossing and having a depth of about 15 to 50 μm. It is starting. This uneven surface is formed in order to improve the fusion bonding property and the pressure bonding property in the laminating process and to enhance the cushioning effect when contacting the solar battery cell. Further, Japanese Patent Laid-Open No. 2002-185027 discloses an encapsulant having a plurality of grooves and / or convex portions formed by embossing on a protective film surface. Particularly, in the case of the encapsulant having the convex portion, the convex portion may have a horizontal diameter of about 0.1 to 2 mm, and the height may be a hemispherical shape having a thickness of 20 to 95% of the film thickness. It is explained that it is desirable to make it possible.

However, such an encapsulant sheet was not sufficient to prevent breakage of the solar cell and to suppress the generation of bubbles, so a further improved encapsulant sheet was required.

In addition, the ethylene vinyl acetate sheet has a serious problem, such as a shrinkage phenomenon of the solar cell due to shrinkage occurs during or during the process of adhesive integration.

Japanese Patent Laid-Open No. 2000-183388 Japanese Patent Laid-Open No. 2002-185027

The present invention has been made to solve the above problems, an object of the present invention is to provide a solar light having a high-strength ultra-fine fiber layer that can prevent the shrinkage of the encapsulant sheet during or after the adhesive integration of the ethylene vinyl acetate sheet It is to provide a low-shrinkable encapsulant sheet for a module and a solar module using the same.

These and other objects and advantages of the present invention will become more apparent from the following description of a preferred embodiment thereof.

The object is an encapsulant sheet and a fiber layer coated on at least one surface of the encapsulant sheet, including an ultrafine fiber layer made of ultrafine fibers formed by electrospinning, wherein the ultrafine fibers are made of polyethylene resin. A low shrinkage encapsulant sheet for a solar module having a high strength ultra-fine fiber layer is characterized.

Here, the polyethylene resin is characterized in that the ultra-high molecular weight polyethylene resin of the weight average molecular weight 1,000,000 ~ 5,000,000.

Preferably, the diameter of the ultra-fine fibers is 1-3000nm, the pore size of the ultra-fine fibers is 1-5000nm, the porosity of the ultra-fine fibers is characterized in that 30-95%.

Preferably, the encapsulant sheet is an ethylene vinyl acetate sheet.

Preferably, the electrospinning is characterized by conventional electrospinning, electro-blowing, melt blown radiation or flash-spinning.

In addition, the object includes a plurality of solar cells and the encapsulant sheet formed on the top and bottom of the plurality of solar cells and the surface-side transparent protective member and the back-side protection member formed on the other surface of the encapsulant sheet, respectively, The ash sheet is achieved by a solar module, characterized in that the low shrinkage encapsulant sheet for a solar module having the high strength ultrafine fiber layer described above.

Here, the solar module is a crystalline solar module, amorphous silicon thin film solar module, amorphous silicon / micro silicon thin film solar module, micro silicon thin film solar cell module, CdTe compound thin film solar module, CIS or CIGS compound thin film solar It is characterized in that the module, a dye-sensitized solar module or an organic solar module (plastic solar module).

According to the present invention, it is possible to prevent the shrinkage of the encapsulant sheet during or after the adhesive integration of the ethylene vinyl acetate sheet.

1 is a schematic view of an electrospinning apparatus.
2 is a cross-sectional view of a conventional solar module.
Figure 3 is a cross-sectional view of a low-shrinkable encapsulant sheet for a solar module having a high strength ultra-fine fiber layer according to an embodiment of the present invention

Hereinafter, the present invention will be described in detail with reference to embodiments and drawings of the present invention. It will be apparent to those skilled in the art that these embodiments are provided by way of illustration only for the purpose of more particularly illustrating the present invention and that the scope of the present invention is not limited by these embodiments .

As can be seen in Figure 3 which is a cross-sectional view of a low-shrinkable encapsulant sheet for a solar module having a high-strength ultra-fine fiber layer according to an embodiment of the present invention, a low-shrinkable bag for a solar module having a high-strength ultrafine fiber layer according to the present invention The ash sheet is an encapsulant sheet and a fiber layer coated on at least one surface of the encapsulant sheet, and includes an ultrafine fiber layer made of ultrafine fibers formed by electrospinning, wherein the ultrafine fibers are made of polyethylene resin. It is done.

In addition, the polyethylene resin constituting the ultra-fine fibers is preferably a weight average molecular weight of ultra high molecular weight polyethylene resin of 1,000,000 ~ 5,000,000.

In addition, the average diameter of the fibers has a great influence on the porosity and pore size distribution of the ultrafine fiber layer. The smaller the fiber diameter, the smaller the pore size and the smaller the pore size distribution. In addition, as the diameter of the fiber is smaller, the specific surface area of the fiber is increased, thereby reducing the possibility of shrinkage of ethylene vinyl acetate. Therefore, in the present invention, the diameter of the ultra-fine fibers of the ultra-fine fiber layer is 1-3000 nm, preferably 1-1000 nm, more preferably 50-800 nm, and the pore size of the ultra-fine fibers is 1-5000 nm, Preferably it is 1-3000 nm, More preferably, it can have the low shrinkage which is excellent to maintain at 1-1000 nm. In addition, the porosity of the ultra-fine fibers is preferably 30-95%.

In addition, according to the present invention, the encapsulant sheet is preferably an ethylene vinyl acetate sheet, but is not limited thereto.

In the present invention, the ultra-high molecular weight polyethylene resin is formed on one or both sides of the ethylene vinyl acetate encapsulant by forming an ultra-fine fiber layer by using ultra-high molecular weight polyethylene resin on the one or both sides of the ethylene vinyl acetate encapsulant. The formation of the ultra-fine fiber layer in the present invention extends the electrospinning concept to electro-blowing, melt-blown or flashspinning in addition to conventional electro-spinning and As a variant thereof, a method of producing ultra-fine fibers by high voltage electric field and air injection is also possible. Therefore, the electrospinning in the present invention may include all these methods.

1 shows a schematic diagram of an electrospinning apparatus, a barrel 1 for storing an ultra high molecular weight polyethylene resin solution, a metering pump 2 for discharging a polymer solution at a constant speed, and a high voltage generator 3 are connected. And a spinning nozzle (4). The polymer solution discharged through the metering pump (2) is discharged as ultra-fine fibers while passing through the spinning nozzle (4) charged by the high voltage generator (3), the grounded metal current collector plate of the conveyor type moving at a constant speed (6) Collected on an ethylene vinyl acetate encapsulant. This ultra-fine fiber web is ultra thin, ultra light, has a very high surface area to volume ratio, and high porosity compared to conventional fibers. As shown in FIG. 1, the formation of the ultrafine fiber layer by the electrospinning method according to the present invention is formed by the gap between the ultrafine fibers and the fibers in which the pore structure is accumulated, thereby obtaining uniform pores.

In addition, the low shrinkage encapsulant sheet for a solar module having a high strength ultrafine fiber layer according to the present invention includes an ultrafine fiber layer containing an ultrahigh molecular weight polyethylene resin, and thus has a high strength superior property to a single layer encapsulant sheet composed of only ethylene vinyl acetate sheet. Can be.

In addition, the photovoltaic module according to the present invention has a plurality of solar cells and a surface sheet formed on the other side of the encapsulant sheet and the encapsulant sheet formed on the upper and lower sides of the plurality of solar cell cells (the surface where the solar cell is not formed), respectively. It includes a transparent protective member and a back side protection member, the encapsulant sheet is characterized in that the low-shrinkable encapsulant sheet for solar modules having a high-strength ultra-fine fiber layer described above.

The solar module is a device that directly converts sunlight into electrical energy, for example, crystalline solar module, amorphous silicon thin film solar module, amorphous silicon / micro silicon thin film solar module, micro silicon thin film solar cell module It may be one of a CdTe compound thin film solar module, a CIS or CIGS compound thin film solar module, a dye-sensitized solar module or an organic solar module (plastic solar module).

Next, the composition of the ethylene vinyl acetate sheet according to the present invention will be described in more detail.

1. Ethylene-Polar Monomer Copolymer

 First, unsaturated carboxylic acid, ester, amide, vinyl ester, etc. are mentioned as a monomer of the ethylene-polar monomer copolymer used for the composition of the sheet | seat concerning this invention. More specifically, unsaturated carboxylic acids, such as acrylic acid, methacrylic acid, fumaric acid, itaconic acid, monomethyl maleic acid, monoethyl maleic acid, maleic anhydride, and itaconic anhydride, lithium, sodium, and potassium of an unsaturated carboxylic acid Salts of monovalent metals such as salts and salts of polyvalent metals such as magnesium, calcium and zinc, methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, n-butyl acrylate, isooctyl acrylate, methyl methacrylate and methacrylate Unsaturated carboxylic acid esters, such as ethyl acid, isobutyl methacrylate, and dimethyl maleate, vinyl esters, such as vinyl acetate and a vinyl propionate, and a type or two or more of sulfur dioxide etc. can be illustrated. More specifically as the ethylene-polar monomer copolymer, an ethylene-unsaturated carboxylic acid copolymer such as an ethylene-acrylic acid copolymer, an ethylene-methacrylic acid copolymer, a part of the carboxyl groups of the ethylene-unsaturated carboxylic acid copolymer described above, or Ethylene- such as ionomers neutralized with the above metals, ethylene methyl acrylate copolymer, ethylene-ethyl acrylate copolymer-ethylene methacrylate methyl copolymer, ethylene-isobutyl acrylate copolymer, ethylene-nbutyl acrylate copolymer Unsaturated carboxylic acid, ester copolymer, ethylene-unsaturated isobutyl-methacrylic acid copolymer, ethylene-unsaturated carboxylic acid ester-unsaturated carboxylic acid copolymer such as ethylene nbutyl-methacrylic acid copolymer, and some or all of the carboxyl groups Ionomers neutralized with the metal, and ethylene-vinyl acetate copolymer The same ethylene-vinyl ester copolymer etc. can be illustrated as a representative example.

Among these, as an ethylene-polar monomer copolymer, the most preferable thing is an ethylene vinyl acetate copolymer (EVA) and / or an ethylene ethyl acrylate copolymer (EEA). Especially preferable is ethylene vinyl acetate copolymer (EVA).

The ethylene-polar monomer copolymer can form a solar cell encapsulant sheet excellent in transparency and water resistance. It is preferable to make content of the polar monomer of the said ethylene-polar monomer copolymer into 20-35 weight part, further 22-34 weight part, especially 28-33 weight part with respect to 100 weight part of said ethylene-polar monomer copolymer. . If the content of the polar monomer is less than 20 parts by weight, the transparency of the encapsulant sheet obtained when crosslinking and curing at high temperature may not be sufficient. If the content of the polar monomer exceeds 35 parts by weight, carboxylic acid, alcohol, amine and the like are likely to occur.

2. Cross-linking agent

It is preferable to include a crosslinking agent in the ethylene-polar monomer copolymer used as the composition of the sheet according to the present invention. Accordingly, durability can be improved while maintaining high reactivity during crosslinking.

The crosslinking agent used in the above-mentioned composition is preferably an organic peroxide or photopolymerization initiator. Among them, an organic peroxide is preferable because an encapsulant sheet having improved temperature dependency of adhesion, transparency, moisture resistance, and penetration resistance can be obtained. As the organic peroxide described above, any one can be used as long as it decomposes at a temperature of 100 ° C. or higher to generate radicals. The organic peroxide is generally selected in consideration of the film formation temperature, the adjustment conditions of the composition, the curing temperature, the heat resistance of the adherend, and the storage stability. In particular, the decomposition temperature of the half-life of 10 hours is preferably 70 ° C or more.

As the above-mentioned organic peroxide, from the viewpoint of processing temperature / storage stability of the resin, for example, bentoyl peroxide curing agent, tert hexyl peroxyl fibrate, tert butyl peroxyl fibrate, 3,5,5-trimethylhexanoyl per Oxides, di-n-octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, 1,1,3,3, -tetramethylbutylperoxy-2-ethylhexanoate, squashic acid peroxide, 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane, 1-cyclohexyl-1-methylethyl peroxy-2-ethylhexanoate, tert-hexylperoxy-2- Ethylhexanoate, 4-methylbenzoyl peroxide, tert-butylperoxy-2-ethylhexanoate, m-tol oil + benzoyl peroxide, benzoyl peroxide, 1,1-bis (tert-butylperoxy) 2-methylcyclohexanate, 1,1-bis (tert-hexyl peroxy) -3,3,5-trimethylcyclohexanate-1,1-bis (tert-butylperoxy) cyclohexanate , 2,2 -Bis (4,4-di-tert-butylperoxycyclohexyl) propane, 1,1-bis (tert-butylperoxy) cyclododecane, tert-hexylperoxyisopropyl monocarbonate, tert-butylper Oxy mareic acid, tert-butylperoxy-3,3,5-trimethylhexanoate, tert-butylperoxylaurate, 2,5-dimethyl-2,5-di (methylbenzoyl peroxy) hexane, tert -Butyl peroxy isopropyl monocarbonate, tert- butyl peroxy-2-ethylhexyl monocarbonate, tert-hexyl peroxy benzoate, 2, 5- dimethyl- 2, 5- di (benzoyl peroxy) hexane, etc. are mentioned. Can be.

As the above-described benzoyl peroxide-based curing agent, any one can be used as long as it generates radicals to decompose at a temperature of 70 ° C. or higher, but a decomposition temperature of 10 hours of half life is preferably 50 ° C. or higher. (Joining) It can select suitably in consideration of temperature, heat resistance of a to-be-adhered body, storage stability. As a benzoyl peroxide type hardening | curing agent which can be used, For example, benzoyl peroxide, 2, 5- dimethyl hexyl-2, 5- bisperoxy benzoate, p-chloro benzoyl peroxide, m-tol-yl peroxide, 2, 4 -Dichloro benzoyl peroxide, t-butyl peroxy benzoate, etc. are mentioned. You may use a benzoyl peroxide type hardening | curing agent in combination of 1 type or 2 or more types.

As for the composition described above, the content of the aforementioned organic peroxide is preferably 0.1 to 2 parts by weight, and more preferably 0.2 to 1.5 parts by weight with respect to 100 parts by weight of the ethylene-polar monomer copolymer. If the content of the organic peroxide is small, the transparency of the encapsulant sheet that can be obtained may be lowered, and if it is large, the compatibility with the copolymer may be deteriorated.

Moreover, although any well-known photoinitiator can be used as a photoinitiator, the thing with good storage stability after mix | blending is preferable. As such a photoinitiator, 2-hydroxy-2-methyl-1- phenyl propane- 1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- (4- (methylthio) phenyl, for example. Acetophenones such as) -2-monoholinopropane-1, benzoin compounds such as benzyldimethyl ketal, benzophenones such as benzophenone, 4-phenylbencophenone and hydroxybenzophenone, isopropyl thioxanthone, 2 Thioxanthones, such as 4-diethyl thioxanthone, a methylphenyl glyoxylate, etc. can be used. Especially preferred are 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, and 2-methyl-1- (4- (methylthio) phenyl) -2-mol. Linopropane-1, benzophenone, etc. are mentioned. If necessary, these photoinitiators can be used by mixing one kind or two or more kinds of photopolymerization accelerators for known pipes of an anodorous acid type or a tertiary amine type, like 4-dimethylamino odor in any case. Moreover, it can be used individually by 1 type only or a mixture of 2 or more types of photoinitiators. As for the composition mentioned above, 0.5-5.0 weight part of content of the photoinitiator mentioned above with respect to 100 weight part of said ethylene-polar monomer copolymers is preferable.

3. Crosslinking aid

Furthermore, the composition of the sheet which concerns on this invention may also contain a crosslinking adjuvant as needed. The crosslinking aid described above may be added to the composition in order to improve the fraction of the ethylene-polar monomer copolymer and to improve the durability. Examples of the crosslinking aid (compound having a radical polymerizable group as a functional group) accompanying this purpose include (meth) macryl esters (e.g., NK) in addition to trifunctional crosslinking aids such as triarylcyanurate and triarylisocyanurate. Monofunctional or bifunctional crosslinking aids of esters); Among these, triaryl lucianurate and triaryl isocyanurate are preferable, and triaryl isocyanurate is especially preferable. These crosslinking adjuvant is generally 10 weight part or less, Preferably it is 0.1-5 weight part with respect to 100 weight part of said ethylene-polar monomer copolymers.

4. Other

The above-mentioned composition is preferably used as a hydroxyl agent for improving or adjusting physical properties (mechanical strength, adhesiveness, transparency, optical properties such as mechanical strength, adhesiveness, transparency, heat resistance, light resistance, crosslinking rate, etc.) or improving mechanical strength, particularly as needed. You may further contain various additives, such as a plasticizer, an adhesion improving agent, an acryloxy group containing compound, a methacryloxy group containing compound, and / or an epoxy group containing compound.

As the hydroxyl agent mentioned above, a metal oxide, a metal hydroxide, a metal carbonate, or a composite metal hydroxide is used, and it can select suitably according to the quantity and use of the acetic acid which generate | occur | produce. Specific examples of the above-mentioned oxidizing agent include magnesium oxide, calcium oxide, magnesium hydroxide, calcium hydroxide, barium hydroxide, magnesium carbonate, barium carbonate, calcium carbonate, calcium borate, zinc stearate, calcium phthalate, calcium zincate, zinc oxide, and calcium silicate. Oxides, oxides, hydroxides, carbonates, carbonates, silicates, borates, zinc salts, metaborates, and the like of the Group 2 metals of the periodic table such as magnesium silicate, magnesium borate, magnesium metaborate, calcium metaborate and barium metaborate Oxides, basic carbonates, basic carbonates, basic zincates and basic substances of Group 14 metals of the periodic table, such as basic carbonates, stearing stones, basic zincites, basic calcite, trioxide, silicon carbide and silicon Complex metal hydroxide aluminum hydroxide gel compounds, such as zinc oxide, aluminum carbide, aluminum hydroxide, and hydroxide hydroxides such as acid salts, etc. . These may be used by 1 type and may mix and use 2 or more types. In the composition described above, the content of the hydroxyl agent is preferably 0.01 to 0.15 parts by weight based on 100 parts by weight of the ethylene-polar monomer copolymer.

Although there is no limitation in particular as a plasticizer mentioned above, ester which is a polybasic acid and ester which is a polyhydric alcohol is generally used. Examples thereof include dioctyl phthalate, dihexyl adipate, triethylene glycol-di-2-ethyl butyrate, butyl secaterate, tetraethylene glycol diheptanoate, and triethylene glycol diperalgonate. . A plasticizer may be used and may be used in combination of 2 or more types. As for content of a plasticizer, the range of 5 weight part or less is preferable with respect to 100 weight part of said ethylene-polar monomer copolymers.

A silane coupling agent can be used for the adhesion promoter mentioned above. Thereby, the sealing material sheet for solar modules which has the outstanding adhesive force can be formed. As a silane coupling agent mentioned above, (gamma)-methacryloxy propyl trimethoxysilane, ((beta) -methoxyethoxy) silane, (gamma)-methacryloxypropyl trimethoxysilane, vinyl triacetoxy silane, (gamma)-glycidoxy Propyltrimethoxysilane, γ-glycithoxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, vinyltrichlorosilane, γ-melcaptopropyltrimethoxysilane, (gamma) '-aminopropyl triethoxysilane, N- (beta)-(aminoethyl)-(gamma) -aminopropyl trimethoxysilane is mentioned. These silane coupling agents may be used alone or in combination of two or more thereof. Moreover, it is preferable that content of the adhesive improvement agent mentioned above is 5 mass or less with respect to 100 weight part of said ethylene-polar monomer copolymers.

As the above-mentioned acryloxy group-containing compound and the above-mentioned methacrylic oxy group-containing compound, there are generally acrylic acid or methacrylic acid derivatives, and for example, esters of acrylic acid or methacrylic acid, and straight chains such as stearyl and lauryl. Alkyl group, a cyclohexyl group, a tetrahydrodopropryl group, an aminoethyl group, 2-hydroxyethyl group, 3-hydroxypropyl group, 3-chloro-2- hydroxy phophil group is mentioned. Diacetone acrylamide is mentioned as an example of an amide. Moreover, ester of polyhydric alcohols, such as ethylene glycol, triethylene glycol, polypropylene glycol, polyethylene glycol, a trimethol propane, pentaerythritol, and acrylic acid or methacrylic acid is also mentioned.

Examples of the epoxy-containing compound described above include triglycidyl tris (2-hydroxyethyl) isocyanurate, neopentylglycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, arylglycidyl ether, 2-edylhexyl glycidyl ether, phenyl glycidyl ether, phenol (ethyleneoxy) 5 glycidyl ether, pt-butylphenyl glycidyl ether, adipic acid diglycidyl ester, phthalic acid diglycidyl ester, Glycidyl methacrylate and butylglycidyl ether.

The above-mentioned acryloxy group-containing compound, the above-mentioned methacryloxy group-containing compound and the above-mentioned epoxy group-containing compound are generally 0.5 to 5.0 parts by weight, particularly 1.0 to 4.0 parts by weight, based on 100 parts by weight of the ethylene-polar monomer copolymer, respectively. It is preferable to include a part.

Furthermore, it is preferable that the composition mentioned above contains a ultraviolet absorber, a light stabilizer, and an anti-aging agent.

As the composition of the present invention contains an ultraviolet absorber, the degradation of the ethylene-polar monomer copolymer and the yellowing of the solar module encapsulant sheet under the influence of irradiated light or the like can be suppressed. Although there is no restriction | limiting in particular as said ultraviolet absorber, 2-hydroxy-4- methoxy benzophenone, 2-hydroxy-4- n-dodecoxy hydroxy phenone, 2, 4- dihydroxy benzophenone, 2 Benzophenone series ultraviolet absorbers such as, 2'-hydroxy-4-methoxybenzophenone and 2-hydroxy-4-nocoxybenzophenone are given as good examples.

As the composition of the present invention contains a light stabilizer, the ethylene-polar monomer copolymer may deteriorate under the influence of irradiated light or the like, and the yellowing of the encapsulant sheet for solar modules may be suppressed. It is good to use the light stabilizer called a hindered amine type as said light stabilizer, and you may use individually or it may use in combination of 2 or more types. As for compounding quantity, 0.01-5 weight part is preferable with respect to 100 weight part of ethylene-polar monomer copolymers. As said anti-aging agent, hindered phenols, such as N, N-hexane- 1, 6- diyl bis [3- (3, 5- di-tert- butyl- 4-hydroxyphenyl) propionamide, for example. Calculation inhibitors, phosphorus-based heat stabilizers, lactone-based heat stabilizers, vitamin E-based heat stabilizers, sulfur-based heat stabilizers and the like.

On the other hand, the photovoltaic module according to the present invention is composed of a surface-side transparent protective member, a solar cell, a back side protective member, and a low-shrinkable encapsulant sheet for a photovoltaic module having a high strength ultra-fine fiber layer according to the present invention. In addition, the configuration except for the low-shrinkable encapsulant sheet for a solar module having the high strength ultra-fine fiber layer has the same configuration as a conventionally known solar module, and is not particularly limited.

Hereinafter, the structure and effect of the present invention will be described in more detail with reference to examples and comparative examples. However, this embodiment is intended to explain the present invention more specifically, and the scope of the present invention is not limited to these embodiments.

Example 1

In order to produce ultra high molecular weight polyethylene fibers by electrospinning on the surface of the encapsulant sheet extruded and cast ethylene vinyl acetate resin, a polymer resin solution in which the ultra high molecular weight polyethylene and the liquid paraffin were stirred at a ratio of 95% by weight and 5% by weight, respectively, was prepared. It injected into the barrel of the electrospinning apparatus as shown in FIG. 1, and discharged the polymer solution at 500 microliters / min using the metering pump. At this time, a charge of 17 kV was applied to the spinning nozzle using a high voltage generator, and an ultra-high molecular weight polyethylene fiber layer having a thickness of 50 µm was laminated on the encapsulant sheet surface. The lamination amount at this time was 12.5 g / m <^2> .

[Example 2]

The final encapsulant sheet was manufactured in the same manner as in Example 1, except that the stacking amount of the ultra high molecular weight polyethylene ultrafine fiber layer on the encapsulant sheet surface was controlled to 25 g / m ² by controlling the discharge rate of the metering pump.

[Example 3]

The final encapsulant sheet was manufactured in the same manner as in Example 1, except that the deposition rate of the ultra-high molecular weight polyethylene ultrafine fiber layer on the encapsulant sheet surface was controlled to 37.5 g / m ² by controlling the discharge rate of the metering pump. .

[Comparative Example]

A final encapsulant sheet was prepared in the same manner as in Example 1 except that the ultrahigh molecular weight polyethylene ultrafine fiber layer was not produced by electrospinning on the encapsulant sheet surface.

The encapsulant sheet according to Examples 1 to 3 and Comparative Examples was measured using a conventional method for measuring a general shrinkage rate, and the results are shown in Table 1 below.

Shrinkage (%) MD TD Example 1 12% 11% Example 2 10% 9% Example 3 8% 8% Comparative Example 20% 17%

As can be seen in Table 1, it can be seen that the embodiments of the low-shrinkable encapsulant sheet for photovoltaic modules of the present invention have a much smaller shrinkage rate than the comparative example.

It is to be understood that the present invention is not limited to the above embodiments and various changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention.

1: Barrel 2: Metering Pump
3: high voltage generator 4: radiation nozzle
5: charged ultrafine fiber 6: grounded metal current collector
11: front side transparent protective member 12: back side protective member
13A: Surface side encapsulant sheet 13B: Back side encapsulant sheet
131: high strength ultrafine fiber layer 130: encapsulant sheet

Claims (7)

A low shrinkage encapsulant sheet for a solar module having a high strength ultrafine fiber layer,
With encapsulant sheet
A fiber layer coated on at least one surface of the encapsulant sheet, the fiber layer comprising an ultra-fine fiber layer made of ultra-fine fibers formed by electrospinning, wherein the ultra-fine fiber is made of polyethylene resin, the high-strength ultra-fine fiber layer Low-sealing encapsulant sheet for solar modules. The method of claim 1,
The polyethylene resin is a weight-average molecular weight of 1,000,000 ~ 5,000,000 ultra-high molecular weight polyethylene resin, characterized in that, a low-shrink encapsulation sheet for solar modules having a high strength ultra-fine fiber layer. The method of claim 1,
The ultrafine fiber has a diameter of 1-3000nm, the pore size of the ultrafine fiber is 1-5000nm, and the porosity of the ultrafine fiber is 30-95%, the solar module having a high strength ultrafine fiber layer. Shrink encapsulant sheet The method of claim 1,
The encapsulant sheet is a low shrinkage encapsulant sheet for a solar module having a high strength ultra-fine fiber layer, characterized in that the ethylene vinyl acetate sheet. The method of claim 1,
The electrospinning, characterized in that the conventional electro-spinning, electro-blowing, melt blown spinning or flash-spinning, characterized in that having a high strength ultra-fine fiber layer Low-shrinkable encapsulant sheet for solar modules. As a solar module,
Multiple solar cells
Including the encapsulant sheet formed on the top and bottom of the plurality of solar cell and the other side of the encapsulant sheet and the front side transparent protection member and the back side protection member,
The encapsulant sheet is a low-shrink encapsulant sheet for a solar module having a high strength ultra-fine fiber layer according to any one of claims 1 to 5, the solar module. The method according to claim 6,
The solar module is a crystalline solar module, amorphous silicon thin film solar module, amorphous silicon / micro silicon thin film solar module, micro silicon thin film solar cell module, CdTe compound thin film solar module, CIS or CIGS compound thin film solar module, Photovoltaic module, characterized in that the dye-sensitized solar module or an organic solar module (plastic solar module).

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