KR101919045B1 - 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 the ultraviolet absorber does not show excellent ultraviolet barrier property and there is a risk that the weather resistance is lowered.

Therefore, it is necessary to develop a technology capable of effectively shielding ultraviolet rays while at the same time minimizing the loss of weatherability and at the same time improving the power generation efficiency of solar cells.

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; And

A wavelength converting layer formed by curing a composition comprising a wavelength converting material that converts a wavelength absorbed from two or more lights to a wavelength higher than the absorbed wavelength,

And the pencil hardness of the surface of the wavelength conversion layer is not less than 1H.

The present invention also relates to

UV curable monomers or oligomers; And forming a wavelength conversion layer on one side of the substrate by using a composition including a wavelength conversion material that converts a wavelength absorbed from two or more kinds of 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 shows luminescence spectra results of Lumogen F Violet 570 as a wavelength converting material, FIG. 5 shows luminescence spectra results of Lumogen F Yellow 083, FIG. 6 shows luminescence spectra of Lumogen F Red 305 Fig. 5 is a graph showing the luminescence spectra results. Fig.
7 to 10 are graphs showing absorbance peaks according to wavelengths of the transparent sheet specimens according to Comparative Examples 1 to 4 of the present invention, respectively.
11 and 12 are graphs showing absorption and emission peaks according to wavelengths of the transparent sheet specimen according to the first and second embodiments of the present invention.
13 is a graph showing luminescence peaks of a transparent sheet specimen according to Comparative Example 1, Comparative Example 2 and Example 1 of the present invention.
14 is a graph showing emission peaks of the transparent sheet specimen according to Comparative Example 1, Comparative Example 3 and Example 2 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.

The transparent sheet according to the present invention includes a wavelength conversion layer. The wavelength conversion layer may comprise an ultraviolet curable monomer or oligomer; And a wavelength conversion material that converts a wavelength absorbed from two or more kinds of light to a wavelength higher than the absorbed wavelength is formed by curing.

The transparent sheet according to an exemplary embodiment of the present invention may further include an ultraviolet barrier layer. The ultraviolet barrier layer may comprise an ultraviolet curable monomer or oligomer; And ultraviolet absorber are cured to form.

The transparent sheet according to an embodiment of the present invention is characterized in that the pencil hardness of the wavelength converting layer and / or the surface of the ultraviolet blocking layer 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, and a load of 500 g is applied to the ultraviolet blocking layer 12 and / or the wavelength converting layer 13 , Which means that there is no scratch in the case of three round trips. When the ultraviolet blocking layer and / or the wavelength conversion layer 13 exhibits a pencil hardness of not less than 1H, 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.

Fig. 1 shows a transparent sheet for an optical module (hereinafter abbreviated as "transparent sheet") according to an exemplary embodiment of the present invention. The transparent sheet 10 according to an exemplary embodiment of the present invention may include an ultraviolet barrier layer 12 and a wavelength conversion layer 13.

The transparent sheet 10 according to the present invention may have a multilayer structure of two or more layers. The transparent sheet 10 according to the present invention has a multilayer structure and can include, for example, a base layer 11, an ultraviolet barrier layer 12 formed on the base layer 11, and a wavelength conversion layer 13 have. At this time, the ultraviolet blocking layer 12 and the wavelength conversion layer 13 may be adjacent to each other or may be formed with the base material 11 therebetween. These layers 11, 12, and 13 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.

Fig. 1 illustrates an example in which the ultraviolet blocking layer 12 and the wavelength conversion layer 13 are 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; An ultraviolet blocking layer 12 formed on one side surface (upper surface in FIG. 1) of the base layer 11; And a wavelength conversion layer 13 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 two or more other functional transparent layers including the base layer 11, the ultraviolet blocking layer 12 and the wavelength converting layer 13 have.

Further, in the present invention, the base layer 11, the ultraviolet blocking layer 12 and the wavelength conversion layer 13 may be in direct contact with each other, or intervening layers may be interposed therebetween. A primer layer (not shown) may be formed between the substrate layer 11 and the ultraviolet blocking layer 12, and between the base layer 11 and the wavelength conversion layer 13, for example. At this time, the primer layer includes a substrate layer 11; And the interlayer adhesion force between the ultraviolet ray layer 12 and the wavelength conversion layer 13, and may include resin adhesives such as acryl-based, urethane-based, epoxy-based and polyolefin-based resins.

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.

The base layer 11 may be subjected to an adhesion strengthening treatment for improving adhesion to the ultraviolet ray blocking layer 12 and / or the wavelength conversion layer 13. 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 (ex. 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 strength between the ultraviolet blocking layer 12 and the wavelength conversion layer 13 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 ultraviolet barrier layer 12 and the wavelength conversion layer 13 may be selected from a coating layer and / or a film layer. Specifically, the ultraviolet blocking layer 12 and the wavelength converting layer 13 may be formed by bonding a film on the base layer 11, or by coating and curing the composition. At this time, when the UV blocking layer 12 and / or the wavelength conversion layer 13 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 UV blocking layer 12 comprises at least an ultraviolet curable monomer or oligomer; And ultraviolet absorber are cured to form. The wavelength conversion layer (13) comprises at least an ultraviolet curable monomer or oligomer; And a wavelength converting material that converts the wavelength absorbed from the light to a wavelength higher than the absorbed wavelength is formed by curing. The surface hardness of the ultraviolet ray blocking layer 12 and the wavelength conversion layer 13 can be increased and excellent scratch resistance can be secured by using an ultraviolet ray hardening monomer or an oligomer for forming the ultraviolet blocking layer 12 and the wavelength converting layer 13 .

The ultraviolet curable monomer or oligomer contained in the composition for forming the ultraviolet blocking layer 12 and the wavelength converting layer 13 may be a conventional ultraviolet curable monomer or oligomer known in the art as long as it is a substance that is cured by irradiation with ultraviolet light. It is available without limit.

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 wavelength conversion material included in the composition for forming the wavelength conversion layer of the present invention 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. The wavelength conversion layer of the present invention is characterized by containing two or more kinds of wavelength conversion materials. In one example, the wavelength conversion material may be selected from two or more 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 mixture of two or more kinds of wavelength conversion materials having different light absorption regions. For example, the wavelength converting material may include a first wavelength converting material that absorbs a wavelength of 300 nm to 500 nm and converts the wavelength to a wavelength of 400 nm to 600 nm, and a second wavelength converting material that absorbs a wavelength of 400 nm to 600 nm, ≪ / RTI > The wavelength conversion is shifted to a longer wavelength side by mixing and using other wavelength converting materials in the light absorbing region, and thus the power generation efficiency of the solar cell can be increased.

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.

Accordingly, when two or more kinds of wavelength conversion materials according to the present invention are included, the weatherability of the solar cell 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. By absorbing the light in the short wavelength region and converting it into a long wavelength, the power generation efficiency is improved.

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.

In one embodiment, the wavelength converting material may include at least two selected from fluorescent materials such as a naphthalimide compound, a metal-organic compound, and a perylene 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, (2-ethyl hexyl) naphthalimide), and derivatives thereof. Examples of the perylene compound include perylene, isobutyl 4,10-dicyanoferylene Isobutyl 4,10-dicyanoperylene-3,9-dicarboxylate, perylene-3,4,9,11-tetracarboxylic acid bis- (2 ', 6'- (2 ', 6'-diisopropylanilide) and perylene-1,8,7,12-tetraphenoxy-3,4,9,10-tetracarboxylic acid bis- Tetracarboxylic acid bis- (2 ', 6'-diisopropylanilide) (perylene-1,8,7,12-tetraphenoxy-3,4,9,10-tetracarboxylic acid bis- -diisopropylanilide)) and / or derivatives thereof.

Examples of the naphthalimide compound include Lumogen F Violet 570 [4,5-dimethyloxy-N- (2-ethylhexyl) naphthalimide, naphthalimide] and / or Lumogen F Blue 650 can be used. As the perylene compound, Lumogen F Yellow 083 [isobutyl 4,10-dicyanopearyl-3,9-dicarboxylate (isobutyl 4,10-dicyanoperylene-3,9-dicarboxylate), Lumogen F Orange 240 [perylene-3,4,9,11-tetracarboxylic acid bis- (2 ', 6'-diisopropylanilide) (2 ', 6'-diisopropylanilide)), Lumogen F Red 305, perylene-1,8,7,12-tetraphenoxy-3,4 , 9,10-tetracarboxylic acid bis- (2 ', 6'-diisopropylanilide) (perylene-1,8,7,12-tetraphenoxy-3,4,9,10-tetracarboxylic acid bis- ', 6'-diisopropylanilide))], Lumogen F Green 850 and / or Lumogen F Yellow 170 can 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 converting material may include a compound represented by the following formula (1) as a metal-organic composite.

[Chemical Formula 1]

In the above formula (1), M is a rare earth element. In the above formula (1), the rare earth element M may be selected from, for example, Eu, La, Ce, Pr, Nd, Gd, Tb, Dy and Lu. In Formula 1, 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 1, n may be, for example, 1 to 500, 1 to 200, 1 to 100, or 1 to 50.

In one embodiment, M in Formula 1 may be Eu. Specifically, the wavelength converting material may include a compound represented by the following formula (2) as a metal-organic composite. In the following formula (2), n is as described in formula (1).

(2)

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 substances listed above, naphthalimide compounds, perylenes compounds and metal-organic compounds (for example, compounds represented by Chemical Formulas 1 and 2) have high ultraviolet absorbing ability (400 nm to 800 nm) which is advantageous for the reaction sensitivity of solar cells and the like.

In one embodiment, the wavelength converting material is a mixture of a naphthalimide-based compound and a metal-organic composite (for example, a compound represented by Chemical Formula 1 and Chemical Formula 2) or a mixture of a perillin- (For example, a compound represented by formula (1) and formula (2)). 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, 1 and formula 2) absorb ultraviolet light in the vicinity of about 300 nm to 380 nm and convert it into visible light in the vicinity of about 600 nm to 620 nm.

Further, when two kinds of materials in which the absorption regions are not overlapped are mixed and used as the wavelength conversion material, the wavelength conversion region can be widened to the long wavelength region. That is, when the naphthalimide-based compound and the metal-organic composite (for example, the compound represented by Chemical Formula 1 and Chemical Formula 2) are mixedly used, 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. When the ferrylin compound and the metal-organic composite are used in combination, light having a wavelength in the vicinity of about 400 to 500 nm is absorbed and converted into light in the vicinity of, for example, about 400 to 500 nm and 580 to 800 nm, The light can be emitted again. Accordingly, the wavelength of the ultraviolet ray to be absorbed is wide, and the ultraviolet ray absorbed is converted into a long wavelength favorable to the solar cell, so that excellent weatherability and high power generation efficiency can be obtained. At this time, the metal-organic complex and the naphthalimide-based compound, or the metal-organic composite and the peryllin-based compound may be mixed in a weight ratio of, for example, 1: 0.2 to 5.

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.

The composition for forming the wavelength conversion layer may contain 0.1 to 30 parts by weight of a wavelength conversion material based on 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 conversion material may be contained in an amount of 0.1 to 30 parts by weight, 0.2 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.

On the other hand, when the transparent sheet according to an embodiment of the present invention includes an ultraviolet absorbing layer, the ultraviolet absorbing agent contained in the composition for forming the ultraviolet absorbing layer is not particularly limited as long as it absorbs ultraviolet rays and has a function of blocking ultraviolet rays. 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 (3).

(3)

In Formula 3, 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 (CH 3) CH 2 OCH} 2 -, and _{-CH 2 CH (CH 3) OCH} 2 - represents one selected from the group consisting of,

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 3, 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 2- (2'-hydroxy-5'-methacryloxyethylphenyl) -2H-benzotriazole.

In one embodiment, the composition forming the ultraviolet barrier layer may comprise 0.1 to 30 parts by weight of the 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 ultraviolet barrier layer 12. Considering this point, the ultraviolet absorber may be included in an amount of 0.2 to 25 parts by weight, 0.2 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.

Further, in one embodiment, the wavelength converting material may be selected from a material that absorbs a 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. There is an advantage that the absorption wavelength band is widened by the combination of the ultraviolet absorber and the wavelength converting material whose absorption wavelengths are not overlapped with each other.

According to a more specific embodiment, the ultraviolet absorbing agent absorbs a wavelength in the wavelength range of 200 to 400 nm, and the wavelength converting material is a wavelength not overlapping with the absorption wavelength of the ultraviolet absorbing agent, for example, 300 nm to 600 nm And may be selected from materials that absorb wavelengths. As a result, the ultraviolet absorber and the wavelength converting material absorb wavelength regions that are different from each other, and the light absorbing ability (blocking ability) is improved. That is, there is an advantage that the absorption wavelength band is widened by the combination of the ultraviolet absorber and the wavelength converting material whose absorption wavelengths are not overlapped with each other.

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 absorber of Formula 3 and the absorption wavelength of the wavelength conversion material (naphthalimide-based compound and perylenic-based compound) do not overlap each other 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 perylin-based compound) of the above-described formula (3), light having a wavelength in the vicinity of 350 nm to 500 nm is absorbed, And the light of this wavelength range can be re-emitted.

According to one example of the present invention, the composition for forming the ultraviolet blocking layer and / or the wavelength converting layer may further comprise a crosslinkable monomer comprising a (meth) acrylate monomer and / or one or more crosslinkable functional groups have.

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 for forming the ultraviolet blocking layer and / or the wavelength conversion layer may contain 40 to 99.9 parts by weight of a (meth) acrylate monomer and 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 for forming the ultraviolet blocking layer and / or the wavelength converting layer 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 at least one of the above-mentioned monomers is contained as the copolymerizable monomer, it is preferable that the (meth) acrylic acid ester monomer is contained in an amount of 1 to 99 parts by weight; 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 composition for forming the ultraviolet blocking layer and / or the wavelength converting layer is not particularly limited and may be carried out by mixing the above-mentioned monomers in an appropriate ratio, and performing solution polymerization, photo polymerization, Such as bulk polymerization, suspension polymerization, or emulsion polymerization. If necessary in this process, suitable polymerization initiators or molecular weight regulators, chain transfer agents and the like may be used together.

The composition for forming the ultraviolet blocking layer and / or the wavelength converting layer according to an exemplary embodiment 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 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, and an epoxy crosslinking agent Is preferably 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 for forming the ultraviolet blocking layer and / or the wavelength conversion layer according to an exemplary embodiment of the present invention may contain a coupling agent, a tackifier, an antioxidant, a colorant, a reinforcing agent, a filler, An antifoaming agent, a surfactant, and a plasticizer.

The composition for forming the ultraviolet blocking layer and / or the wavelength converting layer according to an example of the present invention may further include 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 (e.g., IRGACURE 184, IRGACURE 500, IRGACURE 2959, DAROCUR 1173, Ciba Specialty Chemicals); Phenylglyoxylate-based compounds (ex IRGACURE 754, DAROCUR MBF; Ciba Specialty Chemicals); Benzyldimethylketal compounds (ex IRGACURE 651; Ciba Specialty Chemicals); α-aminoketone-based compounds (ex IRGACURE 369, IRGACURE 907, IRGACURE 1300, Ciba Specialty Chemicals); Monoacylphosphine based compounds (MAPO) (ex. DAROCUR TPO; Ciba Specialty Chemicals); Bisacylphosphine compounds (BAPO) (ex IRGACURE 819, IRGACURE 819DW; Ciba Specialty Chemicals); Phosphine oxide-based compounds (ex IRGACURE 2100; Ciba Specialty Chemicals); Metallocene compounds (ex IRGACURE 784; Ciba Specialty Chemicals); Iodonium salt (ex.IRGACURE 250 from 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 for forming the ultraviolet blocking layer and / or the wavelength converting layer may further include an additive such as a photosensitizer if necessary.

In addition, the thickness of the ultraviolet blocking layer 12 and / or the wavelength conversion layer 13 is not particularly limited. For example, the ultraviolet blocking layer 12 and / or the wavelength conversion layer 13 may have a thickness of 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.

The base layer 11, the ultraviolet barrier layer 12 and / or the wavelength conversion layer 13 may further include other additives. For example, one or more additives selected from heat stabilizers, antioxidants, inorganic fillers, and the like, and such additives may be used as those known in the art.

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 ultraviolet blocking layer 12, and between the base layer 11 and the wavelength conversion layer 13, May include resin adhesives such as acrylic, urethane, epoxy and polyolefin adhesives for interlayer adhesion. 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 ultraviolet blocking layer 12 and / or the wavelength conversion layer 13, It may further comprise an additive.

On the other hand, the method for producing the transparent sheet 10 according to the present invention includes the step of forming the wavelength conversion layer 13 on one side of the base material 11. [ The method for manufacturing the transparent sheet 10 according to an exemplary embodiment of the present invention may further include the step of forming an ultraviolet blocking layer 12 on the other side of the substrate 11. At this time, the wavelength conversion layer 13 may be formed of an ultraviolet ray-curable monomer or oligomer; And a wavelength converting material that converts a wavelength absorbed from two or more kinds of light to a wavelength higher than the absorbed wavelength, and the ultraviolet blocking layer 12 is formed using a UV curable monomer or oligomer; And an ultraviolet absorber. At this time, each of the layers 12 and 13 may be formed by coating each of the above compositions, or may be formed by bonding films formed from the respective compositions.

In forming the ultraviolet blocking layer 12 and the wavelength conversion layer 13, the kinds (components) and the content of the ultraviolet ray-curable monomer or oligomer, ultraviolet absorber and wavelength converting material to be used are as described above . The composition for forming the ultraviolet blocking layer 12 and / or the wavelength conversion layer 13 may further include 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 1]

A transparent PET film having a thickness of 250 mu m was prepared. A composition for forming an ultraviolet blocking layer and a wavelength converting layer was coated on both sides of the PET film, and an ultraviolet blocking layer (12, upper part) and a wavelength converting layer (13, lower part) To thereby prepare a transparent sheet (Fig. 1). At this time, the PET film was coated with an oxazoline primer.

The composition for forming the ultraviolet blocking layer 12 may be prepared by mixing a UV curable monomer, a crosslinking agent, a photo initiator, a leveling agent, and a reactive ultraviolet absorbing agent, A UV curable monomer, a crosslinking agent, a photoinitiator, a leveling agent, and two types of wavelength conversion materials were used in combination. The content of each component constituting the ultraviolet blocking layer 12 and the wavelength conversion layer 13 according to this embodiment is as shown in Table 1 below.

(DPHA), polyfunctional oligomers Gatomer 8800 (Nopko Corp., Korea) and 6-functional group acrylate (Gatomer 8800, Korea) as cross-linking agents and triallyl isocyanurate (Nippon Kasei Chemical), Irgacure 184 (1-hydroxy-cyclohexyl-phenyl-ketone; Chiba Specialty Chemicals) as a photoinitiator, megaface F470 (DIC coporation) as a leveling agent, reaction with ultraviolet Lumogen F violet 570 (Germany, BASF), and a perylene-based organic fluorescent pigment Lumogen F Yellow 083 (Germany, BASF) were used as the wavelength conversion material, and a UV-absorbing agent RUVA93 (Japan Otsuka Chemical Co., Ltd.) were mixed and used.

[Example 2]

In contrast to Example 1, the same procedure was performed except that the wavelength converting material was changed. Specifically, in this embodiment, a naphthalimide-based organic fluorescent pigment Lumogen F violet 570 (Germany, BASF) and a perylene-based organic fluorescent pigment Lumogen F Red 305 (Germany, BASF) were mixed as a wavelength converting material Respectively. The content of each component constituting the ultraviolet blocking layer 12 and the wavelength conversion layer 13 according to this embodiment is as shown in Table 1 below.

[Comparative Example 1]

In contrast to Example 1, the same procedure was performed except that the wavelength converting material was changed. Specifically, in this embodiment, a perylene-based organic fluorescent pigment Lumogen F Violet 570 (BASF, Germany) was used alone as a wavelength conversion material. The content of each component constituting the ultraviolet blocking layer 12 and the wavelength conversion layer 13 according to this comparative example is as shown in Table 1 below.

4 is a graph showing the luminescence spectra of Lumogen F Violet 570, a wavelength conversion material.

[Comparative Example 2]

In contrast to Example 1, the same procedure was performed except that the wavelength converting material was changed. Specifically, in this embodiment, a perylene-based organic fluorescent pigment Lumogen F Yellow 083 (BASF, Germany) was used alone as a wavelength conversion material. The content of each component constituting the ultraviolet blocking layer 12 and the wavelength conversion layer 13 according to this comparative example is as shown in Table 1 below.

FIG. 5 is a graph showing the luminescence spectra of Lumogen F Yellow 083, which is a wavelength conversion material.

[Comparative Example 3]

Compared with the above Example 1, the same procedure was performed except that the wavelength conversion material was changed. Specifically, in this embodiment, a perylene-based organic fluorescent pigment Lumogen F Red 305 product (BASF, Germany) was used alone as a wavelength conversion material. The content of each component constituting the ultraviolet blocking layer 12 and the wavelength conversion layer 13 according to this comparative example is as shown in Table 1 below.

6 is a graph showing the luminescence spectra of Lumogen F Red 305, which is a wavelength converting material.

[Comparative Example 4]

Compared with Example 1, a mixture of polyvinylidene fluoride (PVDF) and polymethyl methacrylate (PMMA) in a weight ratio of 3: 1 as a fluorine resin with a non-curable resin and a mixture of a benzophenone based compound Except that an upper layer of the base layer was formed by mixing UV 531 (manufactured by Songwon Co., Ltd., Korea) and PVDF and PMMA were mixed at a ratio of 3: 1 to form a lower layer of the base layer.

The content of each component constituting the upper and lower layers according to this comparative example is as shown in Table 1 below.

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

The light transmittance was expressed by an average value at 600 nm to 1200 nm.

The average light emission intensity means an average value of the light emission intensities in the wavelength range (550 nm to 700 nm) in which the produced transparent sheet has high reaction sensitivity and exhibits high efficiency.

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.

FIGS. 7 to 10 are graphs showing absorption peaks according to wavelengths of the transparent sheet specimens according to Comparative Examples 1 to 4, and FIGS. 11 and 12 are graphs showing the absorption peak according to Examples 1 and 2 FIG. 5 is a graph showing absorption and emission peaks along the wavelength of the transparent sheet specimen. FIG.

As shown in FIG. 7, the transparent sheet (Comparative Example 1) to which Lumogen F Violet 570 alone was applied as a wavelength converting material absorbed ultraviolet light in the vicinity of about 350 nm to 400 nm and re- emitted as visible light in the vicinity of 400 nm to 550 nm You can tell.

As shown in FIG. 8, the transparent sheet (Comparative Example 2) to which Lumogen F Yellow 083 alone was applied as a wavelength converting material absorbed ultraviolet light in the vicinity of about 400 nm to 500 nm, and emitted again as visible light in the vicinity of 500 nm to 600 nm You can tell.

9, the transparent sheet (Comparative Example 3), to which Lumogen F Red 305 alone was applied as a wavelength conversion material, absorbed ultraviolet light in the vicinity of about 410 nm to 500 nm and re-emitted as visible light in the vicinity of 580 nm to 670 nm You can tell.

10, the transparent sheet (Comparative Example 4) to which the benzophenone-based compound [UV 531] was applied as the ultraviolet (UV) absorbent absorbed ultraviolet light in the vicinity of about 300 to 350 nm, .

As shown in FIG. 11, a transparent sheet (Example 1) in which Lumogen F Violet 570 and Lumogen F Yellow 083 are mixed as the wavelength converting material absorbs light in the vicinity of about 350 nm to 500 nm, Re-release.

As shown in Fig. 12, a transparent sheet (Example 2) in which Lumogen F Violet 570 and Lumogen F Red 305 are mixed as the wavelength converting material absorbs light in the vicinity of about 350 nm to 600 nm and has a wavelength of about 400 nm to 500 nm and 580 nm to 700 nm It can be seen that the light is redirected to the nearby light.

Further, luminescence peaks of the transparent sheets according to the comparative examples and the examples were compared in order to compare the light emission intensities when the wavelength converting materials were solely applied and when the mixed materials were applied.

13 is a graph for comparing the case where Lumogen F Violet 570 and Lumogen F Yellow 083 are applied alone and the case where the luminescence peak of the transparent sheet according to Comparative Example 1, Comparative Example 2 and Example 1 is observed Graph. As shown in Fig. 13, it was found that the average luminescence intensity was superior in the case where the respective wavelength converting materials were mixed and applied (Example 1), as compared with the case where the respective wavelength converting materials were applied alone.

FIG. 14 is a graph for comparing the case where Lumogen F Violet 570 and Lumogen F Red 305 are applied alone, and the emission peak of the transparent sheet according to Comparative Example 1, Comparative Example 3 and Example 2 Graph. As shown in Fig. 14, it was found that the average luminescence intensity was superior in the case where the respective wavelength converting materials were mixed and applied (Example 2), as compared with the case where the respective wavelength converting materials were applied alone.

In addition, as shown in Table 2, it can be seen that the average light emission intensity, pencil hardness and scratch resistance of the transparent sheet according to the examples are superior to those of the comparative examples. In addition, high light transmittance can be seen.

10: transparent sheet 11: substrate layer
12: ultraviolet blocking layer 13: wavelength conversion layer
100: front member 200: sealing material layer
210: front sealing material layer 220: rear sealing material layer 220:
300: back sheet C: solar cell

Claims (26)

A wavelength conversion layer formed by curing a composition comprising an ultraviolet ray-curable monomer or oligomer and a wavelength conversion material for converting a wavelength absorbed from light into a wavelength higher than the absorbed wavelength, the pencil hardness of the surface being not less than 1H; And
An ultraviolet-curable monomer or oligomer, and an ultraviolet absorbent, wherein the ultraviolet-shielding layer is formed by curing and has a surface pencil hardness of 1 H or more,
The wavelength converting material comprises a compound represented by the following formula (1)
Wherein the ultraviolet absorber comprises a compound represented by the following Formula 3:
[Chemical Formula 1]

In the formula (1), M is a rare earth element and n is an integer of 1 or more;
(3)

In Formula 3,
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 (CH 3) CH 2 OCH} 2 -, and _{-CH 2 CH (CH 3) OCH} 2 - represents one selected from the group consisting of,
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; delete The method according to claim 1,
A base layer;
An ultraviolet blocking layer formed on one side of the substrate; And
And a wavelength conversion layer formed on the other side of the substrate. The method according to claim 1,
Wherein the wavelength converting material absorbs a wavelength of 300 to 600 nm and converts the wavelength to a wavelength of 400 to 800 nm.
The method according to claim 1,
The wavelength converting material includes a first wavelength converting material that absorbs a wavelength of 350 nm to 500 nm and converts the wavelength to a wavelength of 400 nm to 600 nm and a second wavelength converting material that absorbs a wavelength of 400 nm to 600 nm and converts the wavelength to a wavelength of 500 nm to 800 nm A transparent sheet for an optical module.
The method according to claim 1,
Wherein the wavelength converting material comprises at least two selected from a naphthalimide compound, a metal-organic compound, and a perylene compound.
delete The method according to claim 1,
Wherein the wavelength converting material comprises a compound represented by the following Formula 2:
(2)

In Formula 2, n is an integer of 1 or more.
The method according to claim 1,
Wherein the composition for forming the wavelength converting layer comprises 0.1 to 30 parts by weight of the wavelength conversion material per 100 parts by weight of the ultraviolet curable monomer or oligomer.
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,
The composition for forming an ultraviolet blocking layer comprises 0.1 to 30 parts by weight of an ultraviolet absorber per 100 parts by weight of an ultraviolet curable monomer or oligomer. The method according to claim 1,
Characterized in that the absorption wavelength of the ultraviolet absorber does not overlap with the absorption wavelength of the wavelength converting material. 15. The method of claim 14,
The ultraviolet absorber absorbs an ultraviolet wavelength of 200 to 400 nm,
Wherein the wavelength converting material absorbs a wavelength of 300 to 600 nm. The method according to claim 1,
Wherein the composition for forming the wavelength conversion layer and / or the ultraviolet blocking layer further comprises a crosslinkable monomer comprising a (meth) acrylate monomer and / or one or more crosslinkable functional groups. 17. The method of claim 16,
Wherein the crosslinking monomer is a cyanurate compound.
17. The method of claim 16,
The composition for forming the wavelength conversion layer and / or the ultraviolet blocking layer preferably contains 40 to 99.9 parts by weight of a (meth) acrylate monomer based on 100 parts by weight of the ultraviolet curable monomer or oligomer and 0.1 to 60 parts by weight of the crosslinkable monomer Transparent sheet for optical module containing part. The method according to claim 1,
The composition for forming the wavelength converting layer and / or the ultraviolet blocking layer further comprises a photoinitiator. 20. The method of claim 19,
The composition for forming the wavelength converting layer and / or the ultraviolet blocking layer comprises 0.1 to 20 parts by weight of a photoinitiator per 100 parts by weight of the ultraviolet curable monomer or oligomer. The method of claim 3,
Further comprising a primer layer formed between the base layer and the wavelength conversion layer and / or between the base layer and the ultraviolet blocking layer.
The transparent sheet for an optical module according to claim 21, wherein the primer layer comprises an oxazoline group-containing compound.
A method of manufacturing a transparent sheet for an optical module according to claim 1,
Forming a wavelength conversion layer on one side of the substrate using a composition comprising an ultraviolet curable monomer or oligomer and a wavelength conversion material that converts the wavelength absorbed from the light to a wavelength higher than the absorbed wavelength; And
A step of forming an ultraviolet blocking layer on the other side of the substrate using a composition comprising an ultraviolet ray-curable monomer or oligomer and an ultraviolet absorber. delete 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. delete

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