KR101941111B1 - Transparent sheet for light module, method for manufacturing the same and light module comprising the same - Google Patents

Abstract

The present invention relates to a transparent sheet for an optical module, a method of manufacturing the same and an optical module, and more particularly, to a transparent sheet for an optical module capable of improving the weather resistance and power generation efficiency of the optical module, will be. INDUSTRIAL APPLICABILITY The transparent sheet and the optical module for an optical module according to the present invention have a high light transmittance and at the same time have an improved weatherability and power generation efficiency by emitting absorbed ultraviolet rays as visible light.

Description

TECHNICAL FIELD [0001] The present invention relates to a transparent sheet for an optical module, a method of manufacturing the same and an optical module,

The present invention relates to a transparent sheet for an optical module, a method of manufacturing the same and an optical module, and more particularly, to a transparent sheet for an optical module capable of improving the weather resistance and power generation efficiency of the optical module, will be.

In recent years, interest in renewable energy and clean energy has increased due to global environmental problems and depletion of fossil fuels. Among them, energy using light is attracting attention as a representative pollution-free energy source that can solve environmental pollution problem and fossil fuel depletion problem. Particularly, photovoltaic cells such as solar cells are rapidly spreading in residential and industrial fields.

Photovoltaic cells are devices that convert sunlight to electrical energy, which typically require long exposure to the external environment to easily absorb sunlight, so that various packaging to protect the internal components is performed, And these units are generally referred to as optical modules.

Most optical modules, for example, optical modules such as a solar cell module, include a front member (glass or front sheet) for protecting internal components (e.g., a solar cell) back sheet.

Generally, in the case of a solar cell module, the solar cell module has a structure in which a transparent front member on which light is incident, an encapsulant layer in which a plurality of solar cell cells are encapsulated, and a back sheet are sequentially laminated. As the transparent front member, a tempered glass or a front sheet is mainly used. The plurality of solar cells are electrically connected to each other, and are packed and sealed by the sealing material layer. For example, Korean Patent No. 10-1022820 and Korean Patent Laid-open No. 10-2011-0020227 disclose the above-mentioned techniques.

The solar cell module is required to have a long life without a reduction in output over a long period of time. For the longevity improvement, the front and back sheets must be able to block water and oxygen which adversely affect the solar cell, and can prevent deterioration due to ultraviolet (UV) rays or the like.

Particularly, in the case of a front sheet positioned directly on the front surface of a solar cell module and directly receiving sunlight, a high light transmittance is required for high power generation efficiency. Further, since the front sheet is exposed to the outside for a long period of time, high weather resistance is required, and in particular, excellent ultraviolet shielding ability is required. When ultraviolet rays are transmitted, the weatherability of the solar cell as well as the front sheet itself is deteriorated.

For this purpose, in most cases, ultraviolet absorbers are used for ultraviolet ray shielding. For example, Japanese Unexamined Patent Application Publication No. 2006-255927 discloses a transparent protective film for a solar cell using an organic ultraviolet absorber such as benzotriazole, and Korean Patent Publication No. 10-2011-0029096 discloses a transparent protective film for zinc oxide (Front sheet) for a solar cell using a light emitting diode (LED).

However, use of only an ultraviolet absorber does not show excellent ultraviolet barrier property. Accordingly, most of the conventional techniques have a problem in that the weather resistance is poor, and it is difficult to show a high power generation efficiency.

Korean Patent No. 10-1022820 Korea Patent Publication No. 10-2011-0020227

Accordingly, it is an object of the present invention to provide an improved transparent sheet for an optical module, a method of manufacturing the same, and an optical module.

The present invention relates to a transparent sheet for an optical module, which is excellent in surface hardness, has a high light transmittance and emits absorbed ultraviolet rays as visible light to improve weatherability and power generation efficiency, a method for producing the same, The purpose of the module is to provide.

According to the present invention,

UV curable monomers or oligomers;

Ultraviolet absorber; And

A resin layer formed by curing a composition including a wavelength converting material that converts a wavelength absorbed from light into a wavelength higher than the absorbed wavelength,

And a pencil hardness of the surface of the resin layer is not less than 1H.

The present invention also relates to

Forming a resin layer on a substrate using a composition comprising an ultraviolet curable monomer or oligomer, an ultraviolet absorber, and a wavelength converting material that converts the wavelength absorbed from the light to a wavelength higher than the absorbed wavelength

The present invention also provides a method of manufacturing a transparent sheet for an optical module.

The present invention also relates to

Front member;

An encapsulant layer formed on the front member and encapsulating the solar cell; And

And a back sheet formed on the sealing material layer,

And at least one selected from the front member and the back sheet comprises the transparent sheet.

According to the present invention, it is possible to provide an improved transparent sheet for an optical module, a method of manufacturing the same, and an optical module. Specifically, the present invention has an effect of simultaneously improving weather resistance and power generation efficiency by having excellent surface hardness and high light transmittance and emitting absorbed ultraviolet rays as visible light.

1 is a sectional view of a transparent sheet for an optical module according to an embodiment of the present invention.
2 is a cross-sectional view of an optical module according to an embodiment of the present invention.
3 is a cross-sectional view of an optical module according to another embodiment of the present invention.
FIG. 4 is a graph showing the absorbance of the reactive ultraviolet absorber RUVA93 according to wavelength, and FIG. 5 is a graph showing the luminescence spectra of Lumogen F Violet 570, which is a wavelength conversion material.
FIGS. 6 and 7 are graphs showing absorption and emission peaks according to wavelengths of a transparent sheet for an optical module according to Examples and Comparative Examples of the present invention. FIG.
8 is a graph showing light transmittance according to wavelengths of a transparent sheet for an optical module according to Examples and Comparative Examples of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The accompanying drawings are provided to aid in understanding the present invention. In the accompanying drawings, the thickness may be enlarged to clearly show each region, and the scope of the present invention is not limited by the thickness, size, and ratio shown in the drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted.

In the present specification, "and / or" is used to mean including at least one of the front and rear components. In the present invention, terms such as " first "and" second "are used to distinguish one element from another, and each element is not limited by the terms.

In this specification, the terms "formed on the surface "," formed on one side ", "formed on both sides" and the like do not mean only that the constituent elements are laminated in direct contact with each other, It also includes the meaning that further elements are formed. For example, "formed on the surface" means that the second component is formed directly on the surface of the first component, as well as the third component, between the first component and the second component, Lt; / RTI > can be further formed.

As used herein, the term "resin " refers to all polymerizable compounds having reactivity and may include, for example, monomers, oligomers, prepolymers, and the like. In addition, the term "(meth) acrylate" may be used herein to mean including acrylate and methacrylate.

As used herein, the unit "weight" may refer to the ratio of the weight between each component.

Fig. 1 shows a transparent sheet for an optical module (hereinafter abbreviated as "transparent sheet") according to an exemplary embodiment to which the composition of the present invention is applied. The transparent sheet 10 according to the present invention includes at least one resin layer 12, wherein the resin layer 12 comprises an ultraviolet curable monomer or oligomer, an ultraviolet absorber, A composition including a wavelength conversion material which converts into a higher wavelength is formed by curing.

The transparent sheet of the present invention is characterized in that the pencil hardness of the surface of the resin layer (12) is not less than 1H. In the present invention, the pencil hardness is measured in accordance with the pencil drawing value described in the test method prescribed in JIS K5600-5-4, which means hardness without scratches when the resin layer is reciprocated three times under a load of 500 g . When the resin layer exhibits a pencil hardness of 1 H or more, there is an advantage of excellent surface hardness. The solar cell module to which the resin layer having excellent surface hardness is applied can prevent the surface scratch phenomenon that may occur due to exposure to the external environment.

The transparent sheet 10 according to the present invention may have a multi-layered structure of one layer or two or more layers. The transparent sheet 10 according to the present invention has a multilayer structure and may include, for example, a base layer 11 and a resin layer 12 formed on the base layer 11. The layers 11 and 12 are all transparent. In the present invention, transparency may mean that the irradiated light (visible light) exhibits a light transmittance of, for example, at least 50%, for example at least 60%, or at least 80%, for example, on a vertical line. The higher the light transmittance is, the better the upper limit is, but the limit is not limited, but it may be 99.9%, 99%, or 98% or less, for example.

The resin layer 12 may be a single layer or a plurality of layers or more. The resin layer 12 may be formed on one side or both sides of the base layer 11, for example. Fig. 1 illustrates an example of the resin layer 12 formed on both surfaces of a base layer 11 as an exemplary embodiment of the present invention. Specifically, the transparent sheet 10 according to the present invention comprises, in accordance with one exemplary embodiment, a base layer 11; A first resin layer 12 formed on one side surface (upper surface in FIG. 1) of the substrate layer 11; And a second resin layer 12 formed on the other side of the substrate layer 11 (the lower surface in FIG. 1).

The laminated structure of the transparent sheet 10 according to the present invention is not limited. The transparent sheet 10 according to the present invention may further include one or more functional transparent layers including a base layer 11 and at least one resin layer 12.

Further, in the present invention, the base layer 11 and the resin layer 12 may be in direct contact with each other, or another intermediate layer may be interposed therebetween. A primer layer (not shown) may be formed between the base layer 11 and the resin layer 12, for example. The primer layer is not limited as long as it is for interlayer adhesion between the substrate layer 11 and the resin layer 12. The primer layer may include a resin adhesive such as acrylic, urethane, epoxy or polyolefin.

Hereinafter, an exemplary embodiment of each component constituting the transparent sheet 10 according to the present invention will be described.

The base layer 11 is not particularly limited as long as it is transparent. The substrate layer 11 may be formed of various materials known in the art, and may be appropriately selected depending on the required functions and applications. The base layer 11 may be selected from a polymer film and the like in one example. Specific examples of the base layer 11 include a single sheet such as a polyester film, an acrylic film, a polyolefin film, a polyamide film and a polyurethane film, a laminated sheet, or a pneumatic article.

The base layer 11 may comprise a polyester resin composed of a polymer film and favorable in terms of heat resistance and the like as a base resin, according to an exemplary embodiment. Examples of the polyester resin include at least one selected from the group consisting of polyethylene terephthalate (PET), polyethylene naphthalate (PEN) and polybutylene terephthalate (PBT) But is not limited thereto. The substrate layer 11 may be selected as a polyolefin-based film, according to another exemplary embodiment. At this time, the polyolefin film is, for example, a polypropylene (PP) film. The base layer 11 is preferably a polyethylene terephthalate (PET) film in one example.

Further, the base material layer 11 may be subjected to an adhesion strengthening treatment for improving adhesion with the resin layer 12. For example, high frequency spark discharge treatment such as corona treatment or plasma treatment is applied to one surface or both surfaces of the substrate layer 11; Heat treatment; Flame treatment; Anchor treatment; Coupling agent treatment; Surface treatment such as primer treatment or chemical activation treatment using gaseous Lewis acid (for example, BF3), sulfuric acid or high temperature sodium hydroxide can be performed. The surface treatment method may be performed by any well-known means commonly used in the general industrial field. The bonding force with the resin layer 12 can be improved through the surface treatment as described above.

In addition, an inorganic vapor deposition layer may be formed on one side or both sides of the substrate layer 11 from the standpoint of further improving moisture barrier properties and the like. The kind of the inorganic substance is not particularly limited and can be adopted without limitation as long as it has a moisture barrier property. For example, silicon oxide or aluminum oxide can be used. The method of forming the inorganic vapor deposition layer on one side or both sides of the substrate layer 11 is not particularly limited and may be, for example, vapor deposition. In the case where the inorganic vapor deposition layer is formed on one surface or both surfaces of the substrate layer 11 as described above, the above-described surface treatment may be performed on the vapor deposition layer after the inorganic vapor deposition layer is formed on the surface of the substrate layer 11 . That is, in one embodiment of the present invention, the spark discharge treatment, the flame treatment, the coupling agent treatment, the anchorage treatment, or the chemical activation treatment described above is performed to further improve the adhesive force on the vapor deposition layer formed on the base layer 11 .

The thickness of the base layer 11 is not particularly limited, and may be, for example, in the range of about 20 탆 to 1000 탆, or about 50 탆 to 300 탆. By adjusting the thickness of the base layer 11 to the same range as described above, it is possible to improve the electrical insulating property, moisture barrier property, mechanical property, handling property, and the like of the transparent sheet 10. In the present invention, the thickness of the base layer 11 is not limited to the above-mentioned range, and it can be suitably adjusted as required.

The resin layer 12 is formed on one side or both sides of the base layer 11 as described above, and it can be selected from a coating layer and a film layer. Specifically, the resin layer 12 may be formed by bonding a film on the base layer 11, or by coating and curing the composition. At this time, when the resin layer 12 is a film, it may be bonded onto the base layer 11 through an adhesive, or may be bonded by thermal fusion (thermal lamination) or the like.

The resin layer 12 is formed by curing a composition comprising at least an ultraviolet curable monomer or oligomer, an ultraviolet absorber and a wavelength conversion material. By using an ultraviolet ray-curable monomer or oligomer, the surface hardness of the resin layer 12 can be increased and excellent scratch resistance can be ensured.

The ultraviolet curable monomer or oligomer contained in the composition may be any conventional ultraviolet curable monomer or oligomer known in the art, as long as it is a substance that is cured by irradiation of ultraviolet light.

For example, the UV-curable monomer may comprise a polyfunctional (meth) acrylate-based compound. The polyfunctional (meth) acrylate compounds include, but are not limited to, trimethylolpropane triacrylate, trimethylolpropane triacrylate, trimethylolpropaneethoxy triacrylate, glycerin propoxylated triacrylate, pentaerythritol triacrylate, Acrylate, dipentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, urethane acrylate, ester acrylate, dipentaerythritol triacrylate, dipentaerythritol hexaacrylate, dipentaerythritol tetraacrylate, , Epoxy acrylate, ether acrylate, and ethylene oxide (EO) modified compounds thereof, and the like. From the viewpoint of improving the surface hardness of the transparent sheet, a compound having a large number of functional groups per molecular weight such as pentaerythritol triacrylate or dipentaerythritol tetraacrylate is preferable.

The ultraviolet absorber of the present invention is not particularly limited as long as it absorbs ultraviolet rays to have an ultraviolet shielding function. For example, the ultraviolet absorber may be selected from materials capable of absorbing an ultraviolet wavelength of about 400 nm or less, more specifically about 100 to 400 nm, and may be selected from, for example, organic, inorganic or reactive ultraviolet absorbers . Among these, a reactive ultraviolet absorber having a reactive group capable of copolymerizing with the ultraviolet curable monomer and / or oligomer is preferable.

By using a reactive ultraviolet absorber having a reactive group capable of copolymerizing with the ultraviolet curable monomer and / or oligomer, the ultraviolet curable monomer and / or oligomer; And the ultraviolet absorber can be increased to have a higher light transmittance and a lower haze value to ensure physical properties such as transparency and at the same time to enhance ultraviolet shielding ability and to secure properties such as weather resistance .

In one embodiment, the ultraviolet absorber may be a compound represented by the following formula (1).

[Chemical Formula 1]

In Formula 1, R ₁ is hydrogen, halogen, an alkoxy group having 1 to 6 carbon atoms, or an aryl group;

R ₂ is hydrogen, an alkyl group having 1 to 6 carbon atoms, or an aryl group;

R ₃ represents R ₄ -R ₅ -R ₆ ,

R ₄ represents a single bond or oxygen,

R ₅ represents a single bond or represents - (CH ₂ ) _m O-, -CH (CH ₃ ) CH ₂ O-, CH ₂ CH (CH ₃ ) O-, - (CH ₂ ) _m OCH ₂ - (CH ₃ ) CH ₂ OCH ₂ -, and -CH ₂ CH (CH ₃ ) OCH ₂ -, and

R ₆ represents an acryloyl group, a methacryloyl group, a styrene group or a vinyl group,

n and m each independently represent an integer of 1 to 4;

In Formula 1, R ₁ is preferably hydrogen; R ₂ is hydrogen or an alkyl group having 1 to 6 carbon atoms;

R ₃ represents R ₄ -R ₅ -R ₆ , R ₄ represents a single bond, R ₅ represents - (CH ₂ ) _m O-, R ₆ represents an acryloyl group or a methacryloyl group,

m represents an integer of 1 to 3;

In one embodiment, the ultraviolet absorber may be at least one selected from the group consisting of 2- (2'-hydroxy-5'-methacryloxyethylphenyl) -2H-benzotriazole,

In one embodiment, the composition may comprise from 0.1 to 30 parts by weight of an ultraviolet absorber per 100 parts by weight of the ultraviolet curable monomer or oligomer. When the amount of the ultraviolet absorber is less than 0.1 part by weight, the ultraviolet absorbing ability depending on the content thereof may be insignificant. If it exceeds 30 parts by weight, for example, it may not be preferable because of the mechanical properties and transparency of the resin layer 12. Considering this point, the ultraviolet absorber may be contained in an amount of 0.2 to 25 parts by weight, 0.2 to 20 parts by weight, or 0.5 to 15 parts by weight based on 100 parts by weight of the ultraviolet curable monomer or oligomer.

The composition according to an example of the present invention may further comprise a (meth) acrylic acid ester-based monomer and / or a crosslinkable monomer containing at least one crosslinkable functional group.

The kind of the (meth) acrylic acid ester-based monomer is not particularly limited. In the present invention, for example, an alkyl (meth) acrylate can be used. Specifically, from the viewpoint of controlling the adhesion of the resin layer, an alkyl (meth) acrylate having an alkyl group having 1 to 14 carbon atoms, preferably 1 to 8 carbon atoms Meth) acrylate can be used. Examples of such monomers include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, (Meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-ethylbutyl (meth) acrylate, n-octyl , Isooctyl (meth) acrylate, or isononyl (meth) acrylate. These may be used singly or in combination of two or more.

The crosslinkable monomer means a compound which simultaneously contains both a copolymerizable functional group such as a carbon-carbon double bond in the molecule and a crosslinkable functional group. The crosslinking monomer may serve to provide a crosslinking point through a crosslinkable functional group or to control the adhesive force under high temperature or high humidity conditions.

The crosslinkable monomer may be a commonly used monomer without any particular limitation. Examples of the crosslinkable monomer include a hydroxyl group-containing monomer or a carboxyl group-containing monomer, which may be used singly or in combination. Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (Meth) acrylate, 2-hydroxyethyleneglycol (meth) acrylate or 2-hydroxypropyleneglycol (meth) acrylate; Examples of the carboxyl group-containing monomer include acrylic acid, methacrylic acid, 2- (meth) acryloyloxyacetic acid, 3- (meth) acryloyloxypropyl acid, 4- (meth) acryloyloxybutyric acid, Butyric acid, itaconic acid, maleic acid, and the like.

In one embodiment, the crosslinking monomer may be a cyanurate based compound. Cyanurate compounds include, but are not limited to, triallyl cyanurate and triallyl isocyanurate.

In one embodiment, the composition may comprise from 40 parts by weight to 99.9 parts by weight of a (meth) acrylate monomer and from 0.1 to 60 parts by weight of a crosslinkable monomer. By adjusting the ratio of the monomer contained in the composition to the above-mentioned range, it is possible to secure a good adhesive force between the base layer and the surface layer.

The composition according to an exemplary embodiment of the present invention may further include a copolymerizable monomer in addition to the (meth) acrylate monomer and the crosslinkable monomer.

The copolymerizable monomer is not particularly limited as long as it is a copolymerizable monomer, and examples thereof include methacrylate, tertiary butyl acrylate, tertiarybutyl methacrylate, iso Butyl methacrylate, isobutyl methacrylate, normal-butyl methacrylate, 1-hexadecyl (meth) acrylate, methyl methacrylate, alkyl (meth) acrylates having a straight-chain or branched-chain alkyl group such as n-propyl methacrylate or sec-butyl methacrylate; N-alkenylformamide having 2 to 20 carbon atoms, 2 to 16 carbon atoms, 2 to 12 carbon atoms, 2 to 8 carbon atoms, or an alkenyl group having 2 to 4 carbon atoms, such as N-vinylformamide; Acrylamide, N, N-diphenyl (meth) acrylamide, N- (n-dodecyl) (meth) acrylamide, N- (meth) acrylamide such as N, N-dimethyl acrylamide or N-hydroxyethyl acrylamide, N-alkyl (meth) acrylamide (Meth) acrylamide, N, N-dialkyl (meth) acrylamide or N, N-diaryl (meth) acrylamide; Alkoxyalkyl (meth) acrylates such as 2-methoxyethyl (meth) acrylate and the like; Dihydrodicyclopentadienyl acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, cyclopropyl (meth) acrylate, acrylate, N-naphthyl acrylate, 2-phenoxyethyl (meth) acrylate, phenyl (meth) acrylate, Acrylate, 2-phenylethyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate or (Meth) acrylate having a saturated or unsaturated cyclic hydrocarbon group or an aromatic group such as cyclohexyl (meth) acrylate and the like; Or styrene may be exemplified.

When the composition contains at least one of the above-mentioned monomers as a copolymerizable monomer, it is preferable that the composition contains 1 to 99 parts by weight of a (meth) acrylic acid ester monomer; 0.5 to 60 parts by weight of a crosslinkable monomer; And 0.5 to 60 parts by weight of a copolymerizable monomer.

The method of polymerizing the above composition is not particularly limited and may be carried out by mixing the above-mentioned monomers in an appropriate ratio and subjecting them to solution polymerization, photo polymerization, bulk polymerization, suspension polymerization, Or by emulsion polymerization. [0033] The term " polymer " If necessary in this process, suitable polymerization initiators or molecular weight regulators, chain transfer agents and the like may be used together.

On the other hand, in the present invention, the wavelength converting material included in the composition for forming the resin layer is not limited as long as it is a material that converts the wavelength absorbed from light (e.g., sunlight) to a wavelength higher than the absorbed wavelength. In one example, the wavelength converting material may be selected from materials that absorb at least ultraviolet light and convert the absorbed ultraviolet light to light having a wavelength higher than ultraviolet wavelength. The wavelength conversion material may be, for example, a substance which absorbs ultraviolet light having a wavelength of 400 nm or less and converts it to a wavelength of 400 nm or more (visible light wavelength or more) to emit at least visible light. More specifically, for example, the wavelength converting material absorbs an ultraviolet wavelength (short wavelength) of about 100 nm to 400 nm, and has a visible wavelength (about 400 nm to 800 nm) or a near-infrared wavelength (about 800 nm to 1,200 nm) ≪ / RTI >

In general, most solar cells are sensitive to wavelengths from about 400 nm to 1,200 nm. Accordingly, the solar cell mainly absorbs light in the wavelength range and generates electricity. Therefore, the short wavelength (about 400 nm or less) in the ultraviolet ray region is low in the sensitivity of the solar cell, and thus it is difficult to exhibit high power generation efficiency. Particularly in the case of a crystalline silicon solar cell or the like. In addition, the sensitivity of the solar cell increases as it goes to a longer wavelength even within the above wavelength range. At this time, a high reaction sensitivity means that the light of the corresponding wavelength is absorbed at a high absorption rate, which means that the power generation efficiency is increased eventually. In addition, high efficiency is not expected due to high wavelength, and most solar cells show high efficiency in the wavelength range of visible light.

Accordingly, when the wavelength conversion material is included in the composition, the weatherability is improved and the power generation efficiency is improved. Specifically, ultraviolet rays are absorbed by the wavelength converting material, and deterioration of the base material 11 and the solar cell C (see Fig. 2) due to the transmission of ultraviolet rays is prevented. The absorbed ultraviolet rays are converted to a visible light wavelength or more (400 nm or more), thereby emitting light having a high sensitivity and a visible light, thereby improving power generation efficiency.

On the other hand, when the wavelength conversion material is converted into a wavelength that is too high, the temperature may increase, which may be undesirable. That is, when the conversion rate to the infrared wavelength is high, the temperature of the solar cell C or the installation structure (electronic device, etc.) around the module can be increased. Accordingly, it is preferable that the wavelength converting material is selected from a substance capable of converting a wavelength of ultraviolet light absorbed into visible light to near-infrared light and emitting a large amount of visible light. In one embodiment, the wavelength converting material is selected from materials that convert the absorbed ultraviolet wavelength to a visible light wavelength of 400 nm to 800 nm.

Furthermore, in one embodiment, the wavelength converting material may be selected from a material that absorbs an ultraviolet wavelength not overlapping with an absorption wavelength of the ultraviolet absorbing agent. In the present invention, the fact that the absorption wavelength of the ultraviolet absorbing agent does not overlap with the absorption wavelength of the wavelength converting material means that the range of the absorption wavelength of the ultraviolet absorbing agent and the absorption wavelength range of the wavelength converting material are not completely equal. By limiting the range of the absorption wavelength of the ultraviolet absorber to a range in which the substrate is not damaged and absorbing the ultraviolet light in the other range using the wavelength converting material, the ultraviolet absorbing ability is improved and the damage of the substrate can be prevented. The combination of the ultraviolet absorber and the wavelength converting material, which do not overlap with each other in absorption wavelength, widens the ultraviolet absorption wavelength band, and ultraviolet light in almost all areas can be absorbed.

According to a more specific embodiment, the ultraviolet absorber absorbs an ultraviolet wavelength in a wavelength range of 200 to 400 nm, and the wavelength conversion material is an ultraviolet wavelength not overlapping with an absorption wavelength of the ultraviolet absorber, Lt; RTI ID = 0.0 > nm. ≪ / RTI > Accordingly, the ultraviolet absorber and the wavelength converting material absorb ultraviolet wavelength regions different from each other, and the ultraviolet absorbing ability (blocking ability) is improved.

In one embodiment, the wavelength converting material may include at least one selected from fluorescent materials such as a naphthalimide-based compound, a metal-organic compound, and a perylene-based compound. These wavelength converting materials are useful in the present invention by converting absorbed light into visible light wavelengths.

Examples of the naphthalimide-based compound include naphthalimide, 4,5-dimethyloxy-N- (2-ethylhexyl) naphthalimide, N- (2-ethyl hexyl) naphthalimide), and derivatives thereof. Examples of the perylene compound include perylene and derivatives thereof. As the naphthalimide compound, organic phosphor materials such as Lumogen F Violet 570 and / or Lumogen F Blue 650 may be used.

 Examples of the perylene compound include perylene, isobutyl 4,10-dicyanoperylene-3,9-dicarboxylate, -dicarboxylate, perylene-3,4,9,11-tetracarboxylic acid bis- (2,6-diisopropylanilide) (perylene-3,4,9,11-tetracarboxylic acid bis- -diixopropylanilide, perylene-1,8,7,12-tetraphenoxy-3,4,9,10-tetracarboxylic acid bis- (2,6-diisopropylanilide) (perylene- Tetrabutyloxy-3,4,9,10-tetracarboylic acid bis- (2,6-diisopropylanilide) and derivatives thereof. Also, for example, Lumogen F Yellow 083 [isobutyl 4,10- Isobutyl 4,10-dicyanoperylene-3,9-dicarboxylate], Lumogen F Orange 240 [perylene-3,4,9,11-tetracarboxylic acid bis- (2,6-diisopropylanilide)), Lumogen F Red 305 [perylene-1,8,7,12 (2,6-diisopropylanilide) - tetraphenoxy-3 , 4,9,10-tetracarboxylic acid bis- (2,6-diisopropylanilide) (perylene-1,8,7,12-tetraphenoxy-3,4,9,10-tetracarboxylic acid bis- 2,6-diisopropylanilide))], Lumogen F Green 850 and / or Lumogen F Yellow 170 may be used.

Further, the metal-organic composite may be a metal-organic composite having at least one metallic element, which may be selected from a metal-organic composite containing, for example, a rare earth element as a metallic element. The wavelength conversion material may include a compound represented by the following formula (2) as a metal-organic composite.

(2)

In Formula 2, M is a rare earth element. In the above formula (2), the rare earth element M may be selected from, for example, Eu, La, Ce, Pr, Nd, Gd, Tb, Dy and Lu. In Formula 2, n is an integer of 1 or more. The upper limit value of n is not limited, but may be, for example, 100 or less. In Formula 2, n may be, for example, 1 to 500, 1 to 200, 1 to 100, or 1 to 50.

In one embodiment, M in Formula 2 may be Eu. Specifically, the wavelength converting material may include a compound represented by the following formula (3) as a metal-organic composite. In the following formula (3), n is as described in formula (2).

(3)

The wavelength converting materials listed above are highly useful for the present invention because they have high light absorbing ability and effectively convert the absorbed light to a wavelength of visible light of 400 nm to 800 nm and have a high emission of visible light. On the other hand, an inorganic material can be considered as a wavelength conversion material. Specifically, metal oxides such as La ₂ O ₂ S: Eu and (Ba, Sr) ₂ SiO ₄ : Eu can be considered as inorganic fluorescent pigments. However, they may have low ultraviolet absorbing power and wavelength conversion efficiency, It is possible to convert the absorbed ultraviolet ray to a too high wavelength (infrared ray). In contrast, among the wavelength converting materials listed above, naphtalimide-based compounds and metal-organic compounds (for example, compounds represented by Chemical Formulas 2 and 3) have high ultraviolet absorbing ability and absorbed ultraviolet rays 400 It is converted into visible light having a wavelength of from 800 to 800 nm to emit visible light having a high reaction sensitivity to a solar cell at a high emission amount.

In one embodiment, the wavelength converting material may be a mixture of a naphthalimide-based compound and a metal-organic composite (for example, a compound represented by Chemical Formula 2 and Chemical Formula 3) among the above listed compounds. In this case, different ultraviolet wavelength regions can be absorbed, and the amount of visible light emission is very high. As a result, high-sensitivity visible light emitted from a solar cell is emitted at a high emission amount, and power generation efficiency (light-to-electricity conversion efficiency) can be very high. For example, the naphthalimide-based compound absorbs ultraviolet light in the vicinity of about 350 nm to 400 nm and converts it into visible light in the vicinity of about 400 nm to 500 nm. The metal-organic composite (for example, 2 and formula 3) absorb ultraviolet rays in the vicinity of about 300 nm to 380 nm and convert them into visible light in the vicinity of about 600 nm to 620 nm.

In addition, when the above two kinds of materials are mixed and used as the wavelength conversion material, the ultraviolet absorption wavelength band can be widened. That is, when the naphthalimide-based compound and the metal-organic composite (for example, the compound represented by Chemical Formula 2 and Chemical Formula 3) are used in combination, ultraviolet light of about 300 to 400 nm is absorbed, It is possible to convert visible light of about 400 nm to 550 nm and near 610 nm into visible light of this wavelength band again. Accordingly, the wavelength of the ultraviolet ray to be absorbed is wide, and the absorbed ultraviolet ray is converted into a visible ray wavelength favorable to the solar cell, thereby having excellent weatherability and high power generation efficiency. At this time, the metal-organic complex compound and the naphthalimide compound may be mixed in a weight ratio of, for example, 1: 0.2 to 5.

Further, in one embodiment, the ultraviolet absorber includes the ultraviolet absorber of Formula 1, for example, 2- (2'-hydroxy-5'-methacryloxyethylphenyl) -2H-benzotriazole, The wavelength conversion material may include at least one selected from a naphthalimide-based compound and a perylene-based compound. In this case, there is an advantage that the absorption wavelength of the ultraviolet absorbent of the above formula (1) does not overlap with the absorption wavelength of the wavelength converting material (naphthalimide compound and peryllin type compound), and light of a wide wavelength range can be absorbed . In the case of applying the ultraviolet absorber and the wavelength conversion material (naphthalimide-based compound and peryllin-based compound) of the above formula (1), ultraviolet light in the vicinity of 300 nm to 400 nm is absorbed, It is possible to convert visible light into visible light and emit visible light of this wavelength range again.

In the present invention, the wavelength conversion material may be in a particulate form. At this time, the wavelength converting material may have an average particle size of, for example, 1 nm to 2 탆, 5 nm to 1 탆, or 10 nm to 500 nm in consideration of the compatibility with the resin and the surface properties of the coating.

In addition, the composition may contain 0.1 to 30 parts by weight of a wavelength conversion material per 100 parts by weight of the ultraviolet curable monomer or oligomer. At this time, when the wavelength converting material is less than 0.1 part by weight, ultraviolet absorption and wavelength conversion efficiency depending on its content may be insignificant. If it exceeds 30 parts by weight, for example, it may not be preferable because of the mechanical properties and transparency of the resin layer 12. Considering this point, the wavelength converting material may be contained in an amount of 0.2 to 25 parts by weight, 0.3 to 20 parts by weight, or 0.4 to 15 parts by weight based on 100 parts by weight of the ultraviolet curable monomer or oligomer.

The composition according to an example of the present invention may further include a crosslinking agent. The crosslinking agent may include at least two or more, two to ten, two to eight, two to six, or two to four functional groups capable of reacting with the crosslinkable functional group contained in the polymer of the composition Crosslinking agent may be used. As such a crosslinking agent, an appropriate type may be selected and used from among conventional crosslinking agents such as an isocyanate crosslinking agent, an epoxy crosslinking agent, an aziridine crosslinking agent and a metal chelate crosslinking agent considering the kind of the crosslinkable functional group contained in the composition.

Examples of the isocyanate crosslinking agent include diisocyanate compounds such as tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isoboron diisocyanate, tetramethylxylene diisocyanate and naphthalene diisocyanate, and diisocyanate compounds such as diisocyanate compound And a reaction product of a polyol such as trimethylolpropane or an isocyanurate adduct of the above diisocyanate compound. Of these, xylene diisocyanate or hexamethylene diisocyanate can be preferably used. As the epoxy crosslinking agent Is preferably at least one selected from the group consisting of ethylene glycol diglycidyl ether, triglycidyl ether, trimethylolpropane triglycidyl ether, N, N, N ', N'- tetraglycidylethylenediamine and glycerin diglycidyl ether There is at least one selected from the group true can be exemplified.

As the aziridine crosslinking agent, N, N'-toluene-2,4-bis (1-aziridinecarboxamide), N, N'-diphenylmethane-4,4'- (2-methyl aziridine) or tri-1-aziridinyl phosphine oxide, and the like, but not limited thereto, and the metal chelate Examples of the crosslinking agent include compounds in which a polyvalent metal such as aluminum, iron, zinc, tin, titanium, antimony, magnesium, and / or vanadium is coordinated to acetylacetone or ethyl acetoacetate.

The crosslinking agent may be contained in an amount of, for example, 0.1 to 60 parts by weight, 0.5 to 50 parts by weight, 1 to 40 parts by weight, or 5 to 30 parts by weight based on 100 parts by weight of the ultraviolet curable monomer or oligomer.

The composition according to an example of the present invention may contain one or more selected from the group consisting of coupling agents, tackifiers, antioxidants, colorants, reinforcing agents, fillers, defoamers, surfactants and plasticizers, The above additives may further be included.

The composition according to an example of the present invention may further comprise a photoinitiator.

Examples of the photoinitiator include a photoinitiator such as a benzoin-based initiator, a hydroxyketone-based initiator, an amino ketone-based initiator, or a phosphine oxide-based initiator, which is capable of generating radicals by light irradiation, Initiators may be used without limitation.

More specifically, examples of the photoinitiator include? -Hydroxyketone compounds (for example, IRGACURE 184, IRGACURE 500, IRGACURE 2959, DAROCUR 1173, Ciba Specialty Chemicals); Phenylglyoxylate-based compounds (e.g., IRGACURE 754, DAROCUR MBF; Ciba Specialty Chemicals); Benzyldimethylketal compounds For example, IRGACURE 651; Ciba Specialty Chemicals); (for example, IRGACURE 369, IRGACURE 907, IRGACURE 1300, Ciba Specialty Chemicals); Monoacylphosphine based compounds (MAPO) (e.g. DAROCUR TPO; Ciba Specialty Chemicals); Bisacylphosphine compounds (BAPO) (e.g., IRGACURE 819, IRGACURE 819DW; Ciba Specialty Chemicals); Phosphine oxide compounds (e.g., IRGACURE 2100; Ciba Specialty Chemicals); Metallocene compounds (e.g., IRGACURE 784; Ciba Specialty Chemicals); Iodonium salts (e.g., IRGACURE 250; Ciba Specialty Chemicals); And mixtures of at least one of the foregoing, and the like, but are not limited thereto.

The photoinitiator may be included, for example, in an amount of 0.1 to 20 parts by weight, 1 to 15 parts by weight, or 2 to 10 parts by weight based on 100 parts by weight of the ultraviolet curable monomer or oligomer. In the above range, the resin layer 12 can be formed which is effectively photopolymerized and has excellent surface hardness and scratch resistance.

 When the content of the photoinitiator is too small, the effect due to the addition may be insignificant. When the content is too large, the physical properties such as durability and transparency may be adversely affected.

The composition may further include an additive such as a photosensitizer, if necessary.

In addition, the thickness of the resin layer 12 is not particularly limited. The resin layer 12 may have a thickness of, for example, 0.1 탆 to 100 탆, 0.5 탆 to 50 탆, 1 탆 to 30 탆, or 2 탆 to 20 탆, but is not limited thereto.

Further, the base layer 11 and / or the resin layer 12 may further include other additives. Specifically, at least one selected from the substrate 11 and the resin layer 12 may further include at least one additive selected from, for example, a heat stabilizer, an antioxidant, an inorganic filler and the like, Those known in the art can be used.

In addition, the transparent sheet 10 according to the present invention may further include various functional layers as necessary. Examples of the functional layer include an adhesive layer, an insulating layer and / or a primer layer. The components constituting the adhesive layer and the insulating layer are not particularly limited, and they may be, for example, a layer composed of ethylene vinyl acetate (EVA) and / or low density linear polyethylene (LDPE).

As described above, a primer layer may be formed between the base layer 11 and the resin layer 12. The primer layer may be formed of a resin such as acrylic, urethane, epoxy or polyolefin Adhesives. The primer layer may comprise an oxazoline group-containing compound according to another exemplary embodiment. The primer layer may specifically include a compound (polymer) containing an oxazoline group as a base resin.

The kind of the oxazoline group-containing polymer contained in the primer layer is not particularly limited and may be any one as long as it is excellent in compatibility with the ultraviolet curable monomer. In the present invention, the oxazoline group-containing polymer may be a homopolymer of an oxazoline group-containing monomer; A copolymer comprising an oxazoline group-containing monomer and at least one comonomer; Or mixtures thereof. ≪ / RTI >

The content of the oxazoline group-containing polymer contained in the primer layer is 5 parts by weight to 100 parts by weight, 10 parts by weight to 95 parts by weight based on 100 parts by weight of the base resin of the primer layer (for example, 20 parts by weight to 80 parts by weight, 40 parts by weight to 100 parts by weight, 50 parts by weight to 95 parts by weight, and the like.

The type of the acrylate resin contained in the primer layer may be the same as or different from that of the acrylate resin constituting the resin layer 12, and may further include various other additives as required.

On the other hand, the method for producing the transparent sheet 10 according to the present invention includes the step of forming the resin layer 12 on the base material 11. [ At this time, the step of forming the resin layer 12 is formed using a composition comprising an ultraviolet ray-curable monomer or oligomer, an ultraviolet absorbing agent, and a wavelength conversion material. At this time, the resin layer 12 may be formed by coating the resin composition or by bonding a resin film formed from the composition.

In addition, in forming the resin layer 12, the types (components) of the ultraviolet-curable monomer or oligomer, ultraviolet absorber and wavelength conversion material to be used, and their contents are as described above. In addition, the composition may further contain other additives as required, and such additives are as described above. In addition, the composition may further include a solvent for dilution, coating and / or dissolution in some cases. The kind and content of the solvent are not particularly limited. The solvent may be selected from, for example, water and / or organic solvents, and the organic solvent may be selected from the group consisting of methyl ethyl ketone (MEK), dimethylformamide (DMF) and dimethylacetamide (DMAC) Or more can be used. The solvent may be used in an amount of, for example, 5 to 500 parts by weight based on 100 parts by weight of the resin.

The transparent sheet 10 of the present invention described above is applied to an optical module. The transparent sheet 10 of the present invention can be applied, for example, to at least one selected from a front member (front sheet) and a back sheet of the optical module.

Meanwhile, the optical module according to the present invention includes at least one or more transparent sheets 10 of the present invention as described above. The optical module according to the present invention includes any structure including the transparent sheet 10 of the present invention as described above. The optical module according to the present invention is not limited as long as it uses light (for example, solar light), and can be selected from, for example, a photovoltaic module, a concrete example, a solar cell module and the like.

2 and 3 show an exemplary embodiment of an optical module according to the present invention. The optical module shown in Figs. 2 and 3 is an example of a solar cell module.

2 and 3, an optical module according to the present invention includes a front member 100, an encapsulant layer 200, a solar cell C, and a back sheet 300 according to an exemplary embodiment can do. At least one selected from the front and back sheets 100 and 300 may include the transparent sheet 10 of the present invention.

The front member 100 may be provided so as to provide a light receiving surface while protecting the front side (upper side in the figure) of the solar cell C. The front member 100 may be of any type as long as it has excellent light transmittance. The front member 100 is a transparent substrate which is advantageous for light incidence, and can be selected from a rigid substrate such as glass (for example, tempered glass) or transparent plastic plate. The front member 100 may be a flexible front sheet, and such a front sheet can be used as usual. The front member 100 may be constructed as described above, but it may be composed of the transparent sheet 10 of the present invention as shown in FIG. 2 according to one embodiment.

The encapsulant layer 200 encapsulates the solar cell C and may include a front encapsulant layer 210 and a rear encapsulant layer 220. 2 and 3, the solar cell C may be packed and fixed between the front encapsulant layer 210 and the rear encapsulant layer 220. In this case,

The sealing material constituting the sealing material layer 200 is not limited. The encapsulant constituting the encapsulant layer 200 is not particularly limited as long as it has adhesiveness and insulation properties, and may include, for example, a conventionally used EVA resin, that is, an ethylene-vinyl acetate copolymer. As the sealing material constituting the encapsulant layer 200, resins other than the EVA resin may be used. As the sealing material constituting the sealing material layer 200, for example, a polyolefin-based sealing material or the like can be used. More specifically, polyolefins such as polyethylene, polypropylene, ethylene / propylene copolymer, and ethylene / propylene / butadiene copolymer can be used.

The plurality of solar cells C are arranged in the encapsulant layer 200. That is, the solar cell C may be packed and fixed (encapsulated) in a state where a plurality of solar cells C are arranged between the front encapsulant layer 210 and the rear encapsulant layer 220. The solar cells C are electrically connected to each other.

In the present invention, the solar cell (C) is not particularly limited. The solar cell C may be selected from, for example, a crystalline solar cell and / or a thin film solar cell. In addition, in the present invention, the solar cell C includes a front electrode type, a rear electrode type, and a combination thereof.

The back sheet 300 is bonded to the bottom of the sealing material layer 200. More specifically, the back sheet 300 is bonded to the lower surface of the back sealing material layer 220. The back sealing material layer 220 and the back sheet 300 may be adhered to each other through thermal lamination (heat sealing) or an adhesive. The adhesive is not particularly limited, and for example, at least one adhesive selected from an acrylic type, a urethane type, an epoxy type and a polyolefin type resin can be used. According to one form, the back sealing material layer 222 and the transparent sheet 10 can be bonded by thermal lamination. The thermal lamination may be conducted at a temperature of, for example, 90 ° C to 230 ° C, or 110 ° C to 200 ° C for 1 minute to 30 minutes, or 1 minute to 10 minutes, but is not limited thereto.

The backsheet 300 can be of any type commonly used. The back sheet 300 may be composed of the transparent sheet 10 of the present invention as shown in Fig. 3 according to one embodiment.

The manufacturing process of the optical module includes the steps of forming the front member 100, the front encapsulant layer 210, the electrically connected solar cell C, the back encapsulant layer 220, and the back sheet 300 according to one form Sequentially stacking them, and then thermally laminating them while vacuum-sucking them integrally. And one or both of the front member 100 and the back sheet 300 include the transparent sheet 10 of the present invention as described above.

Further, the optical module according to the present invention may further include a rear member (not shown) according to an exemplary embodiment. This backing member may be provided on the back surface of the back sheet 300. The rear member may be selectively included depending on the type of the optical module and the installation place, and may be selected from a rigid substrate such as the glass (for example, tempered glass) or a transparent plastic plate.

INDUSTRIAL APPLICABILITY According to the present invention described above, the weather resistance and the power generation efficiency can be improved at the same time. Specifically, the transparent sheet 10 according to the present invention has a high light transmittance and an excellent ultraviolet absorbing / blocking property. Such absorption / blocking of ultraviolet rays improves the weatherability and the like of the optical module as well as the transparent sheet 10 itself. Further, the absorbed ultraviolet rays are converted into visible light and emitted. At this time, the visible light is emitted to the solar cell C to improve the power generation efficiency.

Hereinafter, examples and comparative examples of the present invention will be exemplified. The following examples are provided to illustrate the present invention in order to facilitate understanding of the present invention, and thus the technical scope of the present invention is not limited thereto. Further, the following comparative examples are presented for comparison with the examples, which do not mean the prior art.

[Example]

A transparent PET film having a thickness of 250 mu m was prepared. A resin composition was coated on both sides of the PET film to prepare a transparent sheet having a resin layer 12 having a thickness of about 5 탆 on both sides after drying. At this time, the PET film was coated with an oxazoline primer.

The composition for forming the resin layer 12 was prepared by first mixing an ultraviolet curable monomer, a crosslinking agent, a photoinitiator, a leveling agent, a reactive ultraviolet absorber, and a wavelength conversion material. The content of each component constituting the resin layer 12 according to this embodiment is as shown in Table 1 below.

(DPHA), a polyfunctional oligomer Gatomer 8800 (Nopco, Korea) as a crosslinking agent, triallyl isocyanurate (Nippon Kasei Chemical Co., Ltd.) as a crosslinking agent, Irgacure UV-absorbing agent RUVA93 (Japan, Otsuka Chemical Co., Ltd.) as a UV absorbing agent, and a UV-absorbing agent (wavelength: Lumogen F violet 570 (BASF, Germany) was used as the conversion material.

FIG. 4 is a graph of absorptions according to the wavelength of the reactive ultraviolet absorber RUVA93, and FIG. 5 is a graph showing luminescence spectra of Lumogen F Violet 570, a wavelength conversion material.

[Comparative Example]

(PVDF) and polymethyl methacrylate (PMMA) in a weight ratio of 3: 1 as a non-curable resin as a resin composition and a mixture of a mixture of benzophe Except that UV-531 (manufactured by Songwon Co., Ltd., Korea), which is a non-ionic compound, was used.

The content of each component constituting the resin layer 12 according to this comparative example is as shown in Table 1 below.

The light transmittance, the UV transmittance, the absorption, the emission characteristics, the pencil hardness and the scratch resistance of the transparent sheet specimens according to each of the Examples and Comparative Examples were evaluated using a spectrometer .

The pencil hardness was a measure for evaluating the degree of hardness of the surface. The hardness without scratches was confirmed after three rounds of the coating layer were measured using a pencil hardness tester under the load of 500 g according to the measurement standard JIS K5600-5-4.

The scratch resistance is a measure for evaluating the degree of scratching on the surface. After mounting a steel hand (# 0000) on a friction tester, the coating layer is reciprocated ten times with a load of 500 g and then the number of scratches Respectively. O when the number of scratches was less than 2, Δ when scratches were less than 2 and less than 5, and X when scratches were 5 or more.

The results are shown in Table 2 below.

6 is a graph showing the absorption peak according to the wavelength of the transparent sheet test piece according to the comparative example, and FIG. 7 is a graph showing absorption and emission peaks according to the wavelength of the transparent sheet test piece according to the embodiment Graph.

6, the used transparent sheet (comparative example) to which the benzophenone-based compound [UV 531] was applied as an ultraviolet (UV) absorbent absorbs ultraviolet light in the vicinity of about 300 nm to 350 nm have.

As shown in Fig. 7, a transparent sheet (example) to which a reactive ultraviolet absorbent (RUVA-93) is applied as an ultraviolet (UV) absorbent and a naphthalimide compound [Lumogen F Violet 570] It absorbs ultraviolet light in the vicinity of about 300 nm to 400 nm and re-emits visible light in the vicinity of about 400 nm to 550 nm.

8 is a graph showing light transmittance according to wavelengths of the transparent sheet specimen according to the comparative example and the exemplary embodiment. As shown in FIG. 8, it can be seen that the transparent sheet according to the embodiment effectively blocks ultraviolet rays more than the comparative example. That is, in the case of the transparent sheet according to the embodiment, it can be seen that ultraviolet rays in almost all areas are effectively blocked.

In addition, as shown in Table 2, the transparent sheet according to the examples shows lower ultraviolet transmittance than the comparative example and shows the maximum emission peak in the visible light region. This means that the ultraviolet light shielding property is high and the visible light can be effectively emitted to increase the power generation efficiency. In addition, high light transmittance can be seen.

10: transparent sheet 11: substrate layer
12: resin layer 100: front member
200: sealing material layer 300: back sheet
210: front sealing material layer 220: rear sealing material layer
C: Solar cell

Claims (25)

UV curable monomers or oligomers;
Ultraviolet absorber; And
A resin layer formed by curing a composition including a wavelength converting material that converts a wavelength absorbed from light into a wavelength higher than the absorbed wavelength,
The pencil hardness of the surface of the resin layer is not less than 1H,
Wherein the wavelength converting material absorbs an ultraviolet wavelength not overlapping with an absorption wavelength of the ultraviolet absorbent,
Wherein the ultraviolet absorber is a reactive ultraviolet absorber having a reactor copolymerizable with the ultraviolet curable monomer or oligomer,
Wherein the ultraviolet absorber is a compound represented by the following formula (1)
Wherein the wavelength converting material comprises at least one selected from a naphthalimide-based compound, a metal-organic composite, and a perylene-based compound:
[Chemical Formula 1]

In Formula 1,
R ₁ is hydrogen, halogen, an alkoxy group having 1 to 6 carbon atoms, or an aryl group;
R ₂ is hydrogen, an alkyl group having 1 to 6 carbon atoms, or an aryl group;
R ₃ represents R ₄ -R ₅ -R ₆ ,
R ₄ represents a single bond or oxygen,
R ₅ represents a single bond or represents - (CH ₂ ) _m O-, -CH (CH ₃ ) CH ₂ O-, -CH ₂ CH (CH ₃ )
- (CH ₂ ) _m OCH ₂ -, -CH (CH ₃ ) CH ₂ OCH ₂ -, and -CH ₂ CH (CH ₃ ) OCH ₂ -
R ₆ represents an acryloyl group, a methacryloyl group, a styrene group or a vinyl group,
n and m each independently represent an integer of 1 to 4;
The method according to claim 1,
A base layer; And
And the resin layer formed on one side or both sides of the base layer.
The method according to claim 1,
Wherein the ultraviolet-curable monomer or oligomer comprises a polyfunctional (meth) acrylate-based compound.
The method of claim 3,
The ultraviolet ray-curable monomer may be selected from the group consisting of trimethylolpropane triacrylate, trimethylolpropane triacrylate, trimethylolpropaneethoxy triacrylate, glycerin propoxylated triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, Dipentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, urethane acrylate, ester acrylate, epoxy acrylate, ether acrylate, or ethylene oxide thereof, such as ethylene glycol dimethacrylate, ethylene glycol dimethacrylate, and an ethylene oxide (EO) modified compound.
delete The method according to claim 1,
R < ₁ > is hydrogen; R ₂ is hydrogen or an alkyl group having 1 to 6 carbon atoms;
R ₃ represents R ₄ -R ₅ -R ₆ , R ₄ represents a single bond, R ₅ represents - (CH ₂ ) _m O-, R ₆ represents an acryloyl group or a methacryloyl group,
and m represents an integer of 1 to 3.
The method according to claim 1,
Wherein the ultraviolet absorber is 2- (2'-hydroxy-5'-methacryloxyethylphenyl) -2H-benzotriazole.
The method according to claim 1,
Wherein the composition comprises 0.1 to 30 parts by weight of an ultraviolet absorber per 100 parts by weight of the ultraviolet curable monomer or oligomer.
The method according to claim 1,
Wherein the wavelength converting material absorbs ultraviolet light and converts the ultraviolet light to a wavelength higher than ultraviolet wavelength.
10. The method of claim 9,
Wherein the wavelength converting material converts the absorbed ultraviolet wavelength to a visible light wavelength of 400 nm to 800 nm.
delete The method according to claim 1,
The ultraviolet absorber absorbs an ultraviolet wavelength of 200 to 400 nm,
Wherein the wavelength converting material absorbs an ultraviolet wavelength of 300 to 400 nm.
delete The method according to claim 1,
Wherein the wavelength converting material comprises a compound represented by the following Formula 2:
(2)

In the formula (2), M is a rare earth element and n is an integer of 1 or more.
The method according to claim 1,
Wherein the wavelength converting material comprises a compound represented by the following Formula 3:
(3)

In Formula 3, n is an integer of 1 or more.
The method according to claim 1,
Wherein the composition comprises 0.1 to 30 parts by weight of a wavelength converting material per 100 parts by weight of the ultraviolet curable monomer or oligomer.
The method according to claim 1,
Wherein the composition further comprises a (meth) acrylic ester monomer and / or a crosslinkable monomer comprising at least one crosslinkable functional group.
18. The method of claim 17,
Wherein the crosslinking monomer is a cyanurate compound.
delete The method according to claim 1,
Wherein the composition further comprises a photoinitiator.
21. The method of claim 20,
Wherein the composition comprises 0.1 to 20 parts by weight of a photoinitiator per 100 parts by weight of the ultraviolet curable monomer or oligomer.
3. The method of claim 2,
And a primer layer formed between the substrate layer and the resin layer.
23. The method of claim 22,
Wherein the primer layer comprises an oxazoline group-containing compound.
UV curable monomers or oligomers; Ultraviolet absorber; And forming a resin layer on the substrate using a composition comprising a wavelength converting material that converts the wavelength absorbed from the light to a wavelength higher than the absorbed wavelength,
Wherein the wavelength converting material absorbs an ultraviolet wavelength not overlapping with an absorption wavelength of the ultraviolet absorbent,
Wherein the ultraviolet absorber is a reactive ultraviolet absorber having a reactive group capable of copolymerizing with the ultraviolet curable monomer or oligomer,
Wherein the ultraviolet absorber is a compound represented by the following formula (1)
The method for producing a transparent sheet for an optical module according to claim 1, wherein the wavelength converting material comprises at least one selected from a naphthalimide compound, a metal-organic compound, and a perylene compound.
[Chemical Formula 1]

In Formula 1,
R ₁ is hydrogen, halogen, an alkoxy group having 1 to 6 carbon atoms, or an aryl group;
R ₂ is hydrogen, an alkyl group having 1 to 6 carbon atoms, or an aryl group;
R ₃ represents R ₄ -R ₅ -R ₆ ,
R ₄ represents a single bond or oxygen,
R ₅ represents a single bond or represents - (CH ₂ ) _m O-, -CH (CH ₃ ) CH ₂ O-, -CH ₂ CH (CH ₃ )
- (CH ₂ ) _m OCH ₂ -, -CH (CH ₃ ) CH ₂ OCH ₂ -, and -CH ₂ CH (CH ₃ ) OCH ₂ -
R ₆ represents an acryloyl group, a methacryloyl group, a styrene group or a vinyl group,
n and m each independently represent an integer of 1 to 4;
Front member;
An encapsulant layer formed on the front member and encapsulating the solar cell; And
And a back sheet formed on the sealing material layer,
Wherein at least one selected from the front and back sheets comprises a transparent sheet for an optical module according to claim 1.

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