Laminated film for bifacial solar module and solar module comprising same

Abstract

The present invention relates to a laminated film for a bifacial solar module and a solar module comprising same. In one embodiment, the laminated film for a bifacial solar module comprises a coating layer, a base layer, and a barrier layer, which are sequentially formed, wherein the coating layer has irregularities formed on the surface thereof and is formed from a coating composition, the coating composition comprising a siloxane-based binder containing a repeating structure of chemical formula 1, a fluorine-based (meth)acrylate compound, a curing agent, and inorganic particles: [Formula 1] (Formula 1 is as defined in the detailed description).

Description

Laminated film for double-sided photovoltaic module and photovoltaic module including same

[0001] This patent application is related to the results of the project “Development of core materials for building-type solar power generation with guaranteed long-term reliability (over 25 years) and safety” (led by Sangbo Co., Ltd.; project number: 20213030010290) as part of the “New and Renewable Energy Core Technology Development Project” of the Ministry of Trade, Industry and Energy of the government of the Republic of Korea.

[0002] The present invention relates to a laminated film for a double-sided light-receiving solar module and a solar module including the same.

[0003]

[0004] As the climate crisis intensifies, interest in clean, carbon-free energy and renewable energy sources is growing. Solar cells and their photovoltaic modules are currently the most widely used renewable energy devices.

[0005] In Korea, solar modules utilizing solar cells are rapidly spreading based on the Renewable Energy 3020 policy and implementation plan. In terms of quantity, Korea is known to rank 10th globally in terms of installed solar modules or panels. Due to Korea's limited land area, the land area available for solar panel installation is limited.

[0006] Accordingly, solar panels are being developed and installed in various forms, primarily for buildings, floating, and agricultural applications. Furthermore, research and development are underway to develop solar systems that utilize lightweight solar modules instead of glass to enhance reliability and electrical output. The lighter weight of these lightweight solar systems reduces installation time and labor, thereby lowering installation costs. The higher the transmittance of a solar module's front panel material, the higher the module's electrical output.

[0007] To ensure normal power generation over the approximately 20-year lifespan of a solar module, it must withstand rapid outdoor temperature fluctuations (summer and winter), high UV radiation, and humidity. Therefore, unreliable solar modules experience rapid output drops in harsh outdoor environments. Therefore, the front material of a solar module must ensure superior reliability, including transmittance, UV stability, and moisture permeability. Therefore, research and development is needed for a plastic coating film that possesses properties equivalent to or superior to those of the glass typically installed on the front of a solar module.

[0008] Building-integrated photovoltaics (BIPV) have recently been attracting attention. BIPVs are solar cells integrated into buildings. Instead of installing a separate solar cell structure, they are installed on walls, doors, windows, and other building surfaces, enabling power generation anywhere that receives light. BIPVs can operate bidirectionally, utilizing both sunlight (natural light) from the exterior of the building and artificial light from within. Research is currently underway to develop solar cell systems capable of this bidirectional operation.

[0009] Background technology related to the present invention is disclosed in Japanese Patent Application Laid-Open No. 2006-128474 (published on May 18, 2006, title of invention: solar cell module).

[0010]

[0011] One object of the present invention is to provide a laminated film for a double-sided light-receiving solar module that is capable of generating power through double-sided light reception and has an excellent light transmittance improvement effect and power generation efficiency due to the light trapping phenomenon.

[0012] Another object of the present invention is to provide a laminated film having excellent light transmittance, weather resistance, hydrophilicity, light resistance, water repellency, and stain resistance.

[0013] Another object of the present invention is to provide a laminated film having excellent moisture barrier properties, scratch resistance, and durability.

[0014] Another object of the present invention is to provide a laminated film having an excellent effect of improving radiation cooling efficiency by minimizing thermal conduction resistance between the laminated film and a solar cell element.

[0015] Another object of the present invention is to provide a laminated film applicable to solar cell elements or solar modules or panels at an economical cost while increasing the efficiency of solar modules through double-sided power generation.

[0016] Another object of the present invention is to provide a laminated film having excellent productivity and economic efficiency due to process simplification.

[0017] Another object of the present invention is to provide a method for manufacturing the laminated film.

[0018] Another object of the present invention is to provide a double-sided light-receiving solar module including the laminated film.

[0019]

[0020] One aspect of the present invention relates to a laminated film for a double-sided light-receiving solar module. In one specific example, the laminated film for the double-sided light-receiving solar module comprises a coating layer, a substrate layer, and a barrier layer formed sequentially, wherein the coating layer has a surface with irregularities and is formed from a coating composition comprising a siloxane-based binder having a repeating structure represented by the following chemical formula 1, a fluorinated (meth)acrylate compound, a curing agent, and inorganic particles:

[0021] [Chemical Formula 1]

[0022]

[0023] (In the above chemical formula 1, the R 1 , R 2 and R 3 are each independently a hydrogen atom, C1-C 20 Alkyl group, C1-C20 Alkyl amino group, vinyl group, C1-C 20 Alkyl vinyl group, C1-C 20 Alkyl (meth)acrylate group, C3-C 20 Alkyl (meth)acryloxy group, C6-C 20 An aryl group, a sulfonic acid group, and a structure represented by the following chemical formula 1-1, wherein R 1 , R 2 and R 3 At least one of them has a structure of the following chemical formula 1-1, wherein R 4 is C1-C 20 Alkyl group, C1-C 10 Alkoxy group, C2-C 20 Alkenyl group, C1-C 20 Alkyl amino group, C1-C 20 Alkyl vinyl group, C3-C 20 Alkyl (meth)acrylate group, C3-C 20 Alkyl (meth)acryloxy group, thiol group, C3-C 20 Alkyl thiol group, glycidyloxy group, C1-C 20 Alkyl glycidyloxy group, epoxy group, C1-C 20 Alkyl epoxy group, C4-C 20 Cycloalkyl epoxy group, C6-C 20 Aryl epoxy group and C3-C 20 A heteroaryl epoxy group is selected, wherein a and b are each 0.1 to 0.9, and a + b = 1.

[0024] [Chemical Formula 1-1]

[0025]

[0026] (In the above chemical formula 1-1, the R 5 and R 6 are each independently C1-C 20 Alkyl group, C1-C 20 Alkyl amino group, hydroxyl group and C1-C 20 Selected from among alkoxy groups, and the above R 7 Silver vinyl group, C1-C 20 Alkyl vinyl group, C3-C 20Alkyl (meth)acrylate group and C3-C 20 Alkyl (meth)acryloxy group is selected, and * is a connecting moiety).

[0027] In one specific example, the coating composition may include 100 parts by weight of the siloxane-based binder, 1 to 30 parts by weight of a fluorinated (meth)acrylate compound, 0.1 to 15 parts by weight of a curing agent, and 2 to 50 parts by weight of inorganic particles.

[0028] In one specific example, the coating composition may include the fluorinated (meth)acrylate compound and inorganic particles in a weight ratio of 1:2 to 1:7.

[0029] In one specific example, the inorganic particles may have an average particle diameter (d50) of 5 to 1000 nm.

[0030] In one specific example, the barrier layer may be formed from a composition for a barrier layer comprising a siloxane-based binder having a repeating structure of the chemical formula 1, a curing agent, cellulose nanofibrils, infrared absorbing particles, and a solvent.

[0031] In one specific example, the adhesive layer is further formed on the lower surface of the barrier layer, and the adhesive layer can be formed from a composition for an adhesive layer including a siloxane-based binder, a surface treatment filler, and a solvent represented by the following chemical formula 2:

[0032] [Chemical Formula 2]

[0033]

[0034] (In the above chemical formula 2, the R 8 , R 9 , R 10 and R 11 Each independently represents a hydrogen atom, a hydroxyl group, a mercapto group, a sulfonic acid group, and C1-C 20 Alkyl group, C1-C 10 Alkoxy group, C1-C 20 Alkyl amino group, vinyl group, C1-C 20 Alkyl vinyl group, C1-C 20 Alkyl (meth)acrylate group, C3-C20 Alkyl (meth)acryloxy group or C6-C 20 is selected from among aryl groups, wherein c and d are each 1 to 100, and c and d are included in a weight ratio of 1:0.1 to 1:10.

[0035] In one specific example, the laminated film may have an average surface roughness (Ra) of 0.05 to 0.25 μm.

[0036] Another aspect of the present invention relates to a method for manufacturing a laminated film for the double-sided light-receiving solar module. In one specific example, the method for manufacturing a laminated film includes the step of providing a laminated film in which a coating layer, a substrate layer, and a barrier layer are sequentially formed; wherein the coating layer has a surface with irregularities and is formed from a coating composition comprising a siloxane-based binder having a repeating structure represented by the following chemical formula 1, a fluorinated (meth)acrylate compound, a curing agent, and inorganic particles:

[0037] [Chemical Formula 1]

[0038]

[0039] (In the above chemical formula 1, the R 1 , R 2 and R 3 are each independently a hydrogen atom, C1-C 20 Alkyl group, C1-C 20 Alkyl amino group, vinyl group, C1-C 20 Alkyl vinyl group, C1-C 20 Alkyl (meth)acrylate group, C3-C 20 Alkyl (meth)acryloxy group, C6-C 20 An aryl group, a sulfonic acid group, and a structure represented by the following chemical formula 1-1, wherein R 1 , R 2 and R 3 At least one of them has a structure of the following chemical formula 1-1, wherein R 4 is C1-C 20 Alkyl group, C1-C 10 Alkoxy group, C2-C 20 Alkenyl group, C1-C20 Alkyl amino group, C1-C 20 Alkyl vinyl group, C3-C 20 Alkyl (meth)acrylate group, C3-C 20 Alkyl (meth)acryloxy group, thiol group, C3-C 20 Alkyl thiol group, glycidyloxy group, C1-C 20 Alkyl glycidyloxy group, epoxy group, C1-C 20 Alkyl epoxy group, C4-C 20 Cycloalkyl epoxy group, C6-C 20 Aryl epoxy group and C3-C 20 A heteroaryl epoxy group is selected, wherein a and b are each 0.1 to 0.9, and a + b = 1.

[0040] [Chemical Formula 1-1]

[0041]

[0042] (In the above chemical formula 1-1, the R 5 and R 6 are each independently C1-C 20 Alkyl group, C1-C 20 Alkyl amino group, hydroxyl group and C1-C 20 Selected from among alkoxy groups, and the above R 7 Silver vinyl group, C1-C 20 Alkyl vinyl group, C3-C 20 Alkyl (meth)acrylate group and C3-C 20 Alkyl (meth)acryloxy group is selected, and * is a connecting moiety).

[0043] Another aspect of the present invention relates to a solar module comprising the laminated film for the double-sided light-receiving solar module. In one specific example, the solar module comprises a solar cell element; and the laminated film described above formed on both sides of the solar cell element; wherein a barrier layer of the laminated film is laminated on each side of the solar cell element.

[0044]

[0045] The present invention provides a laminated film for a double-sided light-receiving solar module and a solar module including the same, which enables power generation through double-sided light reception, has an excellent light transmittance improvement effect and power generation efficiency due to a light trapping phenomenon, has excellent light transmittance, weather resistance, hydrophilicity, light resistance, water repellency and stain resistance, has excellent moisture barrier properties, scratch resistance and durability, has an excellent effect of improving radiant cooling efficiency by minimizing thermal conductivity resistance between the laminated film and the solar cell element, and promotes an increase in the efficiency of the solar module through double-sided power generation, and can be applied to solar cell elements, solar modules or panels at an economical cost, and provides a laminated film having excellent productivity and economic feasibility due to process simplification by excluding processes such as imprinting for forming a surface irregularity pattern.

[0046]

[0047] FIG. 1 illustrates a laminated film for a double-sided light-receiving solar module according to one specific example of the present invention.

[0048] Figure 2 illustrates a double-sided light-receiving solar module according to one specific example of the present invention.

[0049] Figure 3 is an image showing the results of the water contact angle measurement of Example 4.

[0050]

[0051] In describing the present invention, if it is determined that a detailed description of a related known technology or configuration may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

[0052] And the terms described below are terms defined in consideration of their functions in the present invention, and may vary depending on the intention or custom of the user or operator, so their definitions should be made based on the contents throughout this specification explaining the present invention.

[0053]

[0054] Laminated film for double-sided photovoltaic modules

[0055] One aspect of the present invention relates to a laminated film for a double-sided light-receiving solar module. Fig. 1 illustrates a laminated film for a double-sided light-receiving solar module according to one specific example of the present invention. Referring to Fig. 1, a laminated film (100) for a double-sided light-receiving solar module comprises a coating layer (130), a substrate layer (120), and a barrier layer (110) formed sequentially.

[0056] Hereinafter, the components of the laminated film will be described in detail.

[0057]

[0058] coating layer

[0059] The coating layer (130) has excellent light transmittance and low moisture permeability and may be included to ensure transparency, light transmittance, and durability. The coating layer may have excellent light transmittance in the visible light range.

[0060] Meanwhile, ethylene tetrafluoroethylene (ETFE) or ethylene chlorofluoroethylene (ECTFE) films, used to replace the tempered glass coating on the front surfaces of solar modules, cannot be synthesized under the Korean Chemical Substances Control Act, resulting in a complete reliance on imports. Furthermore, when these materials are processed at high temperatures using vapor-phase polymerization, large amounts of fluorine can leak, potentially causing serious damage, including explosions and deaths. Furthermore, because only a fixed ratio of raw materials can be adjusted, it's difficult to alter their physical properties.

[0061] The present inventors have completed the present invention by studying a laminated film including a coating layer that is free from the risk of explosion and can be freely processed through coating and curing fixation using a liquid mixture. According to the present invention, the laminated film includes a coating layer including a cured product of a coating composition that can realize easy processing, lightweighting, and economic efficiency, and a solar module having the laminated film attached to one surface of a solar cell element.

[0062] Furthermore, replacing the front glass of solar modules requires long-term weather resistance with minimal yellowing even after long-term use. Transparency, light transmittance, and durability are also important. The coating layer can achieve these goals.

[0063] In one specific example, the coating layer may be formed by coating an organic / inorganic hybrid polymer coating composition (hereinafter, “coating composition”) on one surface of a substrate layer and then curing the coating composition to obtain a cured product.

[0064] In one specific example, the coating layer is formed from a coating composition comprising a siloxane-based binder having a repeating structure of the following chemical formula 1, a fluorinated (meth)acrylate compound, a curing agent, and inorganic particles, and having a surface with unevenness.

[0065] Hereinafter, the components of the coating composition will be described in detail.

[0066]

[0067] Siloxane binder

[0068] The above siloxane-based binder (or organic-inorganic hybrid siloxane-based copolymer) comprises a repeating structure of the following chemical formula 1:

[0069] [Chemical Formula 1]

[0070]

[0071] (In the above chemical formula 1, the R 1 , R 2 and R 3 are each independently a hydrogen atom, C1-C 20 Alkyl group, C1-C 20 Alkyl amino group, vinyl group, C1-C 20 Alkyl vinyl group, C1-C 20 Alkyl (meth)acrylate group, C3-C 20 Alkyl (meth)acryloxy group, C6-C 20 An aryl group, a sulfonic acid group, and a structure represented by the following chemical formula 1-1, wherein R 1 , R2 and R 3 At least one of them has a structure of the following chemical formula 1-1, wherein R 4 is C1-C 20 Alkyl group, C1-C 10 Alkoxy group, C2-C 20 Alkenyl group, C1-C 20 Alkyl amino group, C1-C 20 Alkyl vinyl group, C3-C 20 Alkyl (meth)acrylate group, C3-C 20 Alkyl (meth)acryloxy group, thiol group, C3-C 20 Alkyl thiol group, glycidyloxy group, C1-C 20 Alkyl glycidyloxy group, epoxy group, C1-C 20 Alkyl epoxy group, C4-C 20 Cycloalkyl epoxy group, C6-C 20 Aryl epoxy group and C3-C 20 A heteroaryl epoxy group is selected, wherein a and b are each 0.1 to 0.9, and a + b = 1.

[0072] [Chemical Formula 1-1]

[0073]

[0074] (In the above chemical formula 1-1, the R 5 and R 6 are each independently C1-C 20 Alkyl group, C1-C 20 Alkyl amino group, hydroxyl group and C1-C 20 Selected from among alkoxy groups, and the above R 7 Silver vinyl group, C1-C 20 Alkyl vinyl group, C3-C 20 Alkyl (meth)acrylate group and C3-C 20 Alkyl (meth)acryloxy group is selected, and * is a connecting moiety).

[0075] In one specific example, R in the chemical formula 1 1 , R 2 and R 3 are each independently a hydrogen atom, C1-C10 A moiety composed of an alkyl group and chemical formula 1-1, wherein R 1 , R 2 and R 3 At least one of them is a moiety composed of chemical formula 1-1, wherein R 4 is C1-C 10 It may be an alkyl group, but is not limited thereto.

[0076] C2-C above 20 The alkenyl group may include, for example, a vinyl group.

[0077] In addition, in the chemical formula 1-1, the R 5 and R 6 are each independently a hydroxyl group or C1-C 10 is an alkoxy group, and the above R 7 Silver C3-C 10 It may be an alkyl (meth)acryloxy group, but is not limited thereto.

[0078] In one specific example, 20 to 60 mol% of the hydroxyl groups, alkoxy groups and / or aryloxy groups forming the side chains of the backbone of the inorganic hybrid siloxane copolymer having the repeating structure of Chemical Formula 1 that functions as the binder may be substituted or modified with a moiety having the structure of Chemical Formula 1-1 via an ether bond. In addition, the siloxane binder, which is an inorganic copolymer including the repeating structure of Chemical Formula 1, may have a weight average molecular weight (Mw) of 1,000 to 20,000 g / mol, but is not limited thereto. For example, the siloxane binder may have a weight average molecular weight (Mw) of 1,000 to 10,000 g / mol, 1,000 to 8,000 g / mol, or 1,000 to 5,000 g / mol.

[0079] The constituent unit represented by the mole fraction a in the above chemical formula 1 may be derived from a silane monomer having four hydrolysable alkoxy groups.

[0080] In one specific example, the silane monomer having the four hydrolyzable functional groups may be selected from the group consisting of tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabuthoxysilane, tetraisopropoxysilane, methoxytriethoyxsilane, dimethoxydiethoxysilane, and ethoxytrimethoxysilane, but is not limited thereto.

[0081] Additionally, the constituent unit represented by the mole fraction b in the above chemical formula 1 may be derived from a silane monomer having three hydrolyzable functional groups, namely an alkoxy group. For example, the silane monomers having the three hydrolyzable functional groups are methyltriethoxysilane (MTES), ethyltriethoxysilane (ETES), n-propyltriethoxysilane (PTES), octyltriethoxysilane (OTES), vinyltrimethoxysilane (VTMS), vinyltriethoxysilane (VTES), vinyltriisopropoxysilane (VTIPS), 3-aminopropyltrimethoxysilane (APTMS), 3-aminopropyltriethoxysilane (APTES), 3-(2-Aminoethylamino)propyltrimethoxysilane (AEPTMS), (3-Acryloxypropyl)trimethoxysilane (APTMS), Methacryloxymethyltriethoxysilane (MMS), 3-Methacryloxypropyltrimethoxysilane (MPTMS), 3-Methacryloxypropyltriethoxysilane (MPTES), 3-Mercaptopropyltriethoxysilane (MPTES), 3-Isocyanatopropyltriethoxysilane (It may be selected from the group consisting of, but is not limited to, 2-(3,4-Epoxycyclohexyl)ethyltriethoxysilane (ECETMS), 3-Glycidyloxypropyltrimethoxysilane (GPTMOS), 3-Glycidyloxypropyltriethoxysilane (GPTEOS), Phenyltrimethoxysilane (PTES), (4-chlorophenyl)triethoxysilane (CPTES), and [3-(phenylamino)propyl]trimethoxysilane (PAPTMS).

[0082] Meanwhile, at least one silane-based material can be condensed with a moiety having a structure of Chemical Formula 1-1 on at least some of the side chains constituting the backbone of an inorganic hybrid siloxane copolymer having a repeating structure of Chemical Formula 1. The silane-based material condensed on the side chain of Chemical Formula 1 has at least one hydrolyzable functional group connected to a silicon atom, and at least one vinyl group, C1-C 20 Alkyl vinyl group, C3-C 20 Alkyl (meth)acrylate group and / or C3-C 20 It may have an alkyl (meth)acryloxy group.

[0083] For example, silane-based materials that can be condensed on at least a portion of the side chain of the backbone of an inorganic hybrid siloxane copolymer having a repeating structure of Chemical Formula 1 include vinyltrimethoxysilane (VTMS), vinyltriethoxysilane (VTES), vinyltriiosproposysilane (VTIPS), chloromethylphenylvinylsilane, (3-acryloxypropyl)trimethoxysilane (APTMS), methacryloxymethyltriethoxysilane (MMS), 3-methacryloxypropyltrimethoxysilane (PTMS), It may include, but is not limited to, 3-methacryloxypropyltriethoxysilane (MPTES).

[0084] An organic-inorganic hybrid siloxane copolymer having a repeating structure of Chemical Formula 1 can be manufactured through a polymerization reaction in which a solvent and, if necessary, a catalyst are added to the starting materials, which are silane monomers, to hydrolyze them, induce a condensation reaction, and optionally perform a hydration reaction by adding heating and hydrogen peroxide.

[0085] In one specific example, the polymerization reaction may be performed through a hydrolysis reaction and a condensation reaction by a sol-gel process at a temperature of 25 to 100°C for 2 to 24 hours, but is not limited thereto. At this time, the weight average molecular weight of the ultimately synthesized organic-inorganic hybrid siloxane copolymer can be controlled depending on the amount of polymerization solvent used and the reaction time. By performing the polymerization reaction for 2 to 24 hours, a copolymer having a repeating structure of Chemical Formula 1 and having a weight average molecular weight suitable for use as a binder in a coating composition can be prepared.

[0086] In one specific example, the polymerization solvent in which the silane-based starting material is dispersed may be any polymerization solvent capable of mediating a polymerization reaction between the starting materials. Typically, the polymerization step may be conducted in a soluble solvent capable of forming a homogeneous solution.

[0087] In one specific example, the polymerization solvent may be selected from the group consisting of aliphatic hydrocarbon solvents, ether solvents, acetate solvents, alcohol solvents, ketone solvents, amide solvents, silicone solvents, and combinations thereof. For example, the polymerization solvent may include, but is not limited to, one or more of propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), butyl cellosolve (BC), methyl cellosolve (MC), ethylene glycol (EG), propylene glycol (PG), N-methyl-2-pyrrolidone (NMP), dimethylacetamide (DMAc), propylene glycol diacetate (PGDA), propylene glycol normal propyl ether (PnP), tetrahydrofuran, toluene, xylene, butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, methanol, ethanol, n-propanol, isopropanol, butanol, butoxyethanol, pentanol, octanol, hexane, heptane, ethers, and ketones.

[0088] In the above polymerization reaction, as long as the aforementioned starting materials can be uniformly dissolved in the polymerization solvent, the content of the polymerization solvent is not particularly limited. In one exemplary aspect, the amount of the polymerization solvent used in the polymerization reaction can be adjusted to a range of about 5 to 60 parts by weight, preferably about 20 to 50 parts by weight, based on the total content of each reactant including the polymerization solvent.

[0089] Additionally, acid catalysts and / or basic catalysts may be used to promote hydrolysis and / or condensation reactions. For example, these catalysts may be used in an aqueous solution form.

[0090] For example, the acid catalyst may include, but is not limited to, one or more of inorganic acids such as hydrochloric acid, sulfuric acid, and nitric acid; and organic acids such as toluenesulfonic acid, formic acid, acetic acid, butyric acid, palmitic acid, oxalic acid, and tartaric acid. In addition, the basic catalyst may include, but is not limited to, alkali metal hydroxides such as sodium hydroxide, lithium hydroxide, and potassium hydroxide; alkaline earth metal compounds such as barium hydroxide, barium hydroxide monohydrate, barium hydroxide octahydrate, calcium hydroxide, and magnesium hydroxide; and quaternary ammonium compounds such as tetramethylammonium hydroxide, tetramethylammonium chloride, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, tetrabutylammonium fluoride, benzyltrimethylammonium hydroxide, and benzyltriethylammonium hydroxide. It may include, but is not limited to, one or more of ammonia, triethylamine, tripropylamine, n-butylamine, di-n-butylamine, tri-n-butylamine, imidazole, pyridine, 3-methylpyridine, 4-dimethylaminopyridine, N,N-diisopropylethylamine, and ammonium perchlorate.

[0091]

[0092] Fluorinated (meth)acrylate compounds

[0093] The above fluorinated (meth)acrylate compound includes a fluorinated (meth)acrylate monomer and / or a fluorinated (meth)acrylate oligomer. In one specific example, the fluorinated (meth)acrylate compound may have a surface energy of 5 dyne / cm to 10 dyne / cm. As the number of carbon fluorides increases, the water contact angle of the surface may increase while the surface energy may decrease. A coating layer with improved weather resistance and durability may be formed. Therefore, a coating layer obtained from the coating composition according to the present invention can maximize stability even when used outdoors for a long period of time under high temperature and high humidity conditions.

[0094] In one specific example, the fluorine-based (meth)acrylate compound is trifluoroethyl (meth)acrylate (e.g., 2,2,2-trifluoroethyl (meth)acrylate), pentafluoropropyl (meth)acrylate (e.g., 2,2,3,3,3-pentafluoropropyl (meth)acrylate), tetrafluoropropyl (meth)acrylate (e.g., 2,2,3,3-tetrafluoropropyl (meth)acrylate), hexafluoroisopropyl (meth)acrylate (e.g., 1,1,1,3,3,3-hexafluoroisopropyl (meth)acrylate), hexafluorobutyl (meth)acrylate (e.g., 2,2,3,4,4,4-hexafluorobutyl (meth)acrylate), heptafluorobutyl (meth)acrylate (e.g., 2,2,3,3,4,4,4-heptafluorobutyl (meth)acrylate), octafluoropentyl (meth)acrylate, octafluoro-5-(trifluoromethyl)hexyl (meth)acrylate, dodecafluoroheptyl (meth)acrylate, trifluoro-2-(trifluoromethyl)-2-hydroxy-4-methyl-5-pentyl (meth)acrylate, tridecafluorooctyl (meth)acrylate, perfluorooctyl (meth)acrylate (e.g., 1H,1H-perfluoro-n-octyl (meth)acrylate), dodecafluoro-2-hydroxy-8-(trifluoromethyl)nonyl (meth)acrylate, hexadecafluoro-9-(trifluoromethyl)decyl (meth)acrylate, heptadecafluorodecyl (meth)acrylate, perfluorodecyl (meth)acrylate, heneicosafluorododecyl (meth)acrylate, icosafluoro-11-(trifluoromethyl)dodecyl (meth)acrylate, dodecafluoro-7-(trifluoromethyl)octyl (meth)acrylate, combinations thereof, and oligomers thereof, but is not limited thereto.

[0095] In one specific example, the fluorinated (meth)acrylate compound may be included in an amount of 1 to 30 parts by weight based on 100 parts by weight of the siloxane-based binder. When included in the above content range, the surface hardness and durability of the coating layer may be prevented from deteriorating, while the water contact angle may be improved, resulting in excellent water repellency, reduced surface energy, and excellent weather resistance. For example, the fluorinated (meth)acrylate compound may be included in an amount of 2 to 25 parts by weight, 2 to 20 parts by weight, 2 to 15 parts by weight, 2 to 10 parts by weight, or 2 to 8 parts by weight. For example, the fluorinated (meth)acrylate compound may be included in an amount of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or 30 parts by weight based on 100 parts by weight of the siloxane binder.

[0096]

[0097] hardener

[0098] The above coating composition may include at least one of a photopolymerization initiator and a thermal curing agent as a curing agent. The photopolymerization initiator may induce a photopolymerization reaction of a siloxane-based binder, a fluorine-based (meth)acrylate-based compound, etc. in the coating composition by irradiation with an appropriate light source such as ultraviolet (UV) rays.

[0099] In one specific example, the photopolymerization initiator is 1) an acetophenone-based photopolymerization initiator such as 2,2'-diethoxyacetophenone, 2,2'-dibutoxyacetophenone, 2-hydroxy-2-methylpropiophenone, pt-butyltrichloroacetophenone, pt-butyldichloroacetophenone, 4-chloroacetophenone, 2,2'-dichloro-4-phenoxyacetophenone, 2) benzophenone, 4,4'-dimethylaminobenzophenone, 4,4'-dichlorobenzophenone, 3,3'-dimethyl-2-methoxybenzophenone, 4-phenyl benzophenone, hydroxy benzophenone, acrylated benzophenone, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethyl 3) Thioxanthone-based photopolymerization initiators such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropyl thioxanthone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-3-yl]-1-(O-acetyloxime), 2,4-diethyl thioxanthone, 2,4-diisopropyl thioxanthone, 2-chloro thioxanthone, 2-dodecyl thioxanthone, 2,4-dimethyl thioxanthone, 2,4-diethyl thioxanthone, etc. 4) Benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin Benzoin-based photopolymerization initiators such as isobutyl ether, benzyl dimethyl ketal, and methyl benzoyl formate, 5) 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis(trichloromethyl)-s-triazine, 2,4-trichloromethyl-6-triazine, bis(trichloromethyl)-6-styryl-s-triazine, 2-4-trichloromethyl(piperonyl)-6-triazine, 2-4-trichloromethyl(4'-methoxystyryl)-6-triazine, 2-(3',4'-dimethoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4'-methoxy naphthyl)-4,6-bis(trichloromethyl)-s-triazine, 2,4-Trichloromethyl-4-methylnaphthyl-6-triazine, 2-(p-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-p-methoxystyryl-4,6-bistrichloromethyl-s-triazine, 2-piphenyl-4,6-bis(trichloromethyl)-s-triazine, 2,4-Bistrichloromethyl-6-p-methoxystyryl-s-triazine and other triazine photopolymerization initiators, 6) diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl(2,4,6-trimethylbenzoyl)phenylphosphinate, 2,2-bis(2-chlorophenyl)-4,4,5,5-tetraphenyl-1,2-biimidazole and other photopolymerization initiators may be included.

[0100] For example, the photopolymerization initiators sold commercially include Irgacure 369 (2-Benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, hereinafter, manufactured by Ciba Specialty Chemical Co.), Irgacure 651 (2,2-Dimethoxy-1,2-diphenylethan-1-one), Irgacure 907 (2-Methyl-1-(4-methyl thio) phenyl-2-(4-morpholinyl)-1-propanone), Irgacure 819 (Bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide), Irgacure 184 (1-Hydroxy-cyclohexyl-phenyl-ketone), Irgacure 250 (Iodonium, (4-methylphenyl)[4-(2-methylpropyl) phenyl]-, hexafluorophosphate(1-)), Irgacure 127 (2-Hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl}-2-methyl-propan-1-one), etc.

[0101] The above-mentioned thermosetting agent may be a latent thermosetting agent that does not cure at low temperatures but cures at high temperatures. The latent thermosetting agent may include at least one of an amine-based, imidazole-based, dihydrazide-based, and organic peroxide-based thermosetting agent.

[0102] In one specific example, the curing agent may be included in an amount of 0.1 to 15 parts by weight based on 100 parts by weight of the siloxane-based binder. When included in the above range, the mixing property and curing reaction speed of the composition can be easily controlled, thereby providing excellent curing efficiency and preventing defects such as yellowing of the coating layer. For example, the curing agent may be included in an amount of 0.1 to 10 parts by weight, 0.1 to 8 parts by weight, 0.1 to 7 parts by weight, or 1 to 6 parts by weight. For example, the curing agent may be included in an amount of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 parts by weight based on 100 parts by weight of the siloxane-based binder.

[0103]

[0104] inorganic particles

[0105] The above inorganic particles may be included for the purpose of forming a rough pattern on the surface of the coating layer to increase light transmittance. For example, the above inorganic particles may include metal or non-metal oxide particles, or metal or non-metal nitride particles.

[0106] When the above-mentioned inorganic particles are included, a rough pattern can be easily formed on the surface of the coating layer, and complex processes such as nanoimprinting for conventional pattern formation can be eliminated, thereby simplifying the process and improving productivity and economy.

[0107] The above-mentioned inorganic particles may be spherical, ellipsoidal, polyhedral or irregularly shaped. For example, they may be spherical.

[0108] In one specific example, the inorganic particles may have an average particle diameter (d50) of 5 nm to 1000 nm. Under the above conditions, the optical properties of the coating layer may be excellent. For example, the average particle diameter may be 5 nm to 500 nm. In other examples, the average particle diameter may be 5 nm to 300 nm, 10 nm to 200 nm, 10 nm to 100 nm, or 10 nm to 80 nm.

[0109] In one specific example, the inorganic particles may include at least one of silica-based inorganic particles and polystyrene-based inorganic particles.

[0110] In one specific example, the silica-based inorganic particles may be in the form of colloidal silica, in which silica is dispersed in an organic solvent. Under the above conditions, the particles may exhibit excellent dispersibility and workability, while also improving hardness and light transmittance.

[0111] The above inorganic particles may be used by mixing two or more types of inorganic particles having different average particle diameters to further improve the light collection efficiency of the coating layer.

[0112] For example, the inorganic particles may include first inorganic particles having an average particle diameter of 100 nm to 1.5 μm and second inorganic particles having an average particle diameter of 10 nm to 50 nm. Under the above conditions, a rough pattern may be formed on the surface of the coating layer to increase light transmittance and thus improve light collection efficiency.

[0113] In one specific example, the inorganic particles may be included in an amount of 2 to 50 parts by weight based on 100 parts by weight of the siloxane-based binder. Within the above content range, the coating layer may be prevented from having poor appearance and reduced flexibility, while easily forming a surface roughness pattern to have excellent light transmittance, and the mechanical properties such as wear resistance, scratch resistance, and pencil hardness may be excellent without reducing durability. For example, the inorganic particles may be included in an amount of 8 to 50 parts by weight, 10 to 50 parts by weight, 15 to 45 parts by weight, 20 to 40 parts by weight, or 25 to 35 parts by weight. For example, the inorganic particles may be included in an amount of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 parts by weight based on 100 parts by weight of the siloxane-based binder.

[0114] In one specific example, the coating composition may include the inorganic particles and the siloxane-based binder in a weight ratio of 1:1 to 1:6. When included in the above weight ratio range, the composition has excellent mixing and dispersibility, and the durability of the coating layer can be improved, as well as hardness and light transmittance. For example, the composition may include the inorganic particles and the siloxane-based binder in a weight ratio of 1:1 to 1:6.

[0115] In one specific example, the coating composition may include the fluorinated (meth)acrylate compound and the inorganic particles in a weight ratio of 1:2 to 1:7. When included in the above weight ratio range, the composition has excellent mixing and dispersibility, the durability of the coating layer is excellent, and surface irregularities can be easily formed, thereby improving light transmittance. For example, the composition may include a weight ratio of 1:3 to 1:7, a weight ratio of 1:4 to 1:7, or a weight ratio of 1:5 to 1:7.

[0116]

[0117] additives

[0118] In one specific example, the coating composition may further comprise one or more additives selected from the group consisting of a leveling agent, a filler, and a surfactant.

[0119] In one specific example, the coating composition may further include a leveling agent to improve applicability to a substrate. The leveling agent may be a commercially available silicone-type leveling agent, a fluorine-type leveling agent, an acrylic-type leveling agent, or the like, and is not particularly limited to a specific leveling agent.

[0120] In one specific example, the leveling agent may be a nonionic surfactant such as a polyether-modified polydimethylsiloxane, a polyester-modified polydimethylsiloxane, a polyether-modified hydroxy-functional polydimethylsiloxane, a polyether-ester-modified hydroxy-functional polydimethylsiloxane, an acrylic-functional polyester-modified polydimethylsiloxane, a polyoxyethylene alkyl ether, a polyoxyethylene octylphenyl ether, a polyoxyethylene nonylphenyl ether, a polyoxyethylene alkyl allyl ether, a polyoxyethylene polyoxypropylene block copolymer, a sorbitan fatty acid ester, or a polyoxyethylene sorbitan fatty acid ester.

[0121] In one specific example, the additive may be included in an amount of 0.01 to 15 parts by weight based on 100 parts by weight of the siloxane-based binder, but is not limited thereto. For example, the additive may be included in an amount of 0.05 to 5 parts by weight, and in another example, 0.1 to 1 part by weight. For example, the additive may be included in an amount of 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 parts by weight based on 100 parts by weight of the siloxane-based binder.

[0122] For example, the leveling agent may be included in an amount of 0.01 to 15 parts by weight relative to 100 parts by weight of the siloxane-based binder, but is not limited thereto. For example, it may be included in an amount of 0.05 to 5 parts by weight, and for another example, it may be included in an amount of 0.1 to 1 part by weight. When included in the above content range, the applicability to the substrate may be excellent. For example, the leveling agent may be included in an amount of 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 parts by weight relative to 100 parts by weight of the siloxane-based binder.

[0123]

[0124] Non-fluorinated (meth)acrylate compounds

[0125] In one specific example, the coating composition may further comprise a non-fluorinated (meth)acrylate compound.

[0126] The above non-fluorinated (meth)acrylate compound may include a non-fluorinated (meth)acrylate monomer and / or a non-fluorinated (meth)acrylate oligomer.

[0127] For example, the non-fluorine-based (meth)acrylate compound may include a monofunctional (meth)acrylate compound and / or a polyfunctional (meth)acrylate compound.

[0128] In one specific example, the monofunctional (meth)acrylate compound is C1~C 20 Alkyl group, C2~C 20 Alkenyl group, C2~C 20 Alkynyl group, C1~C 20 Alkoxy group, C1~C 20 Alkoxyalkyl group, C1~C 20 Aliphatic (meth)acrylate compounds substituted with alkoxyallyl groups, epoxy groups, etc.; unsubstituted or C1~C 10 Alkyl group, C2~C 10 Alkenyl group, C2~C 10alkynyl group of, or C1-C 10 Cycloalkyl (meth)acrylate compounds having C5-C8 groups substituted with alkoxy groups; unsubstituted or C1-C 10 Alkyl group, C2-C 10 Alkenyl group, C2-C 10 alkynyl group of, or C1-C 10 C5~C substituted with an alkoxy group 20 Aryl (meth)acrylate compounds; C1~C 20 It may be selected from the group consisting of allyl alkoxylate compounds having an alkoxy group; urethane-based (meth)acrylate-based compounds and combinations thereof.

[0129] In one specific example, the C2~C 20 The alkenyl (meth)acrylate compound may be selected from the group consisting of butadiene (meth)acrylate, hexadiene (meth)acrylate, octadiene (meth)acrylate, combinations thereof, and oligomers thereof, but is not limited thereto.

[0130] In one specific example, the above C1~C 20 The alkoxy (meth)acrylate compound may be selected from the group consisting of, but is not limited to, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, ethylene glycol methyl ether (meth)acrylate, ethylene glycol phenyl ether (meth)acrylate, diethylene glycol methyl ether (meth)acrylate, diethylene glycol ethyl ether (meth)acrylate, 1,3-butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, combinations thereof, and oligomers thereof.

[0131] In one specific example, the above C1~C 20The alkoxyalkyl (meth)acrylate compound may be selected from the group consisting of, but is not limited to, 2-hydroxy-ethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-hydroxy-propyl (meth)acrylate, 2-hydroxy-butyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, trimethoxybutyl (meth)acrylate, combinations thereof, and oligomers thereof.

[0132] In one specific example, the epoxy (meth)acrylate compound may be selected from the group consisting of epoxy (meth)acrylate, epoxycyclohexylmethyl (meth)acrylate, glycidyl (meth)acrylate, methyl glycidyl (meth)acrylate, combinations thereof, and oligomers thereof, but the present invention is not limited thereto.

[0133] In one specific example, the C5-C8 cycloalkyl (meth)acrylate compound may be selected from the group consisting of, but is not limited to, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, isobornyl (meth)acrylate, combinations thereof, and oligomers thereof.

[0134] In one specific example, the C5-C 20 The aryl (meth)acrylate compound may be selected from the group consisting of benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, combinations thereof, and oligomers thereof, but is not limited thereto.

[0135] In one specific example, the allyl alkoxylate compound may be selected from the group consisting of allyl propoxylate, allyl monopropoxylate, combinations thereof, and oligomers thereof, but is not limited thereto.

[0136] In one specific example, the urethane-based (meth)acrylate-based compound may be a radical polymerizable unsaturated group-containing oligomer or prepolymer obtained by reacting a polyisocyanate-based compound having a plurality of isocyanate groups with a polyol-based compound having a plurality of hydroxyl groups, and then reacting the polyisocyanate-based compound with a (meth)acrylate-based compound containing hydroxyl groups.

[0137] In one specific example, the polyisocyanate compound may be selected from the group consisting of, but is not limited to, 2,4-trylene diisocyanate and isomers thereof, diphenylmethane diisocyanate, hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, and combinations thereof.

[0138] In one specific example, the polyol compound may be a polyhydroxy compound selected from the group consisting of polycarbonate polyols, polyester polyols, polyether polyols, polycaprolactone polyols, and combinations thereof. For example, the polyhydroxy compound can be selected from the group consisting of glycerin-ethylene oxide adduct, glycerin-propylene oxide adduct, glycerin-tetrahydrofuran adduct, glycerin-ethylene oxide-propylene oxide adduct, trimethylolpropane-ethylene oxide adduct, trimethylolpropane-propylene oxide adduct, trimethylolpropane-tetrahydrofuran adduct, trimethylolpropane-ethylene oxide-propylene oxide adduct, dipentaerythritol-ethylene oxide adduct, dipentaerythritol-propylene oxide adduct, dipentaerythritol-tetrahydrofuran adduct, dipentaerythritol-ethylene oxide-propylene oxide adduct, and combinations thereof.

[0139] In one specific example, the polyol compound may be a polyhydric alcohol. For example, the polyhydric alcohol may be selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 2-methyl-1,3-propanediol, 1,3-butanediol, an adduct of bisphenol A and propylene oxide or ethylene oxide, 1,2,3,4-tetrahydroxybutane, glycerin, trimethylolpropane, 1,2-cyclohexane glycol, 1,3-cyclohexane glycol, 1,4-cyclohexane glycol, paraxylene glycol, bicyclohexyl-4,4-diol, 2,6-decarin glycol, 2,7-decarin glycol, and combinations thereof.

[0140] In one specific example, the hydroxyl group-containing (meth)acrylate compound may be selected from the group consisting of 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, tris(hydroxyethyl)isocyanuric acid di(meth)acrylate, pentaerythritol tri(meth)acrylate, and combinations thereof, but is not limited thereto.

[0141] In one specific example, the multifunctional (meth)acrylate compound may be added for the purpose of improving solvent resistance, hardness, etc. For example, the multifunctional (meth)acrylate compound may be selected from the group consisting of pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, t-butylpropane tri(meth)acrylate, combinations thereof, and oligomers thereof, but is not limited thereto.

[0142] In one specific example, the non-fluorinated (meth)acrylate compound may be included in an amount of 5 to 350 parts by weight based on 100 parts by weight of the siloxane binder. When included in the above content range, the occurrence of defects such as cracks in the coating layer may be prevented, while providing excellent hardness. For example, the compound may be included in an amount of 10 to 300 parts by weight. For example, the non-fluorinated (meth)acrylate compound may be included in an amount of 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340 or 350 parts by weight based on 100 parts by weight of the siloxane binder.

[0143]

[0144] solvent

[0145] In one specific example, the coating composition may further include a solvent. The solvent is used to ensure formability and dispersibility, and its type is not particularly limited. For example, the solvent may include one or more of water, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), butyl cellosolve (BC), methyl cellosolve (MC), ethylene glycol (EG), propylene glycol (PG), N-methyl-2-pyrrolidone (NMP), dimethylacetamide (DMAc), propylene glycol diacetate (PGDA), propylene glycol normal-propyl ether (PnP), tetrahydrofuran, toluene, xylene, butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, methanol, ethanol, n-propanol, isopropanol, butanol, butoxyethanol, pentanol, octanol, hexane, heptane, ether, and ketone. When the solvent is included, the adhesion of the coating layer to the substrate can be improved. For example, water (ultrapure water) may be included.

[0146] In one specific example, the coating composition may contain 20 to 400 parts by weight of a solvent relative to 100 parts by weight of the siloxane-based binder. Within the above content range, the coating composition exhibits excellent mixing and dispersibility, and the viscosity of the composition can be easily controlled, thereby forming a coating layer of uniform thickness, while preventing a decrease in durability and chemical resistance of the coating layer. For example, the content may be 50 to 300 parts by weight, 100 to 300 parts by weight, 150 to 300 parts by weight, 200 to 300 parts by weight, or 220 to 270 parts by weight. For example, the solvent may be included in an amount of 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390 or 400 parts by weight based on 100 parts by weight of the siloxane-based binder.

[0147]

[0148] The method for applying the coating composition onto the substrate layer is not particularly limited. For example, spin coating such as the central drop spin method, roll coating, spray coating, bar coating, knife coating, casting coating, dip coating, gravure coating, slit coating using a slit nozzle such as the discharge nozzle method, or a dispensing method may be used, and the coating composition may be applied onto the substrate by combining two or more methods.

[0149] In one specific example, the coating layer (130) may have an average surface roughness (Ra) of 0.05 to 0.25 μm. Under the above conditions, the surface may have excellent water-repellent properties and light transmittance.

[0150] In one specific example, a coating composition applied to a substrate may be cured using a light source, such as an LED lamp, that emits light in the ultraviolet wavelength range, to form a coating layer on the substrate layer. For example, the coating layer may have a thickness of 0.1 to 500 μm, but is not limited thereto.

[0151] In one specific example, the substrate or barrier layer having the coating composition applied on one surface is soft baked at a temperature of 70 to 100° C. and / or exposed to 300 to 1000 mJ / cm 2 It can be cured by irradiating with ultraviolet rays having an intensity of . Optionally, a drying step for evaporating the solvent included in the coating composition can be performed prior to the UV irradiation. The drying step can be performed at a lower temperature than the curing process, and by performing the drying step, a coating layer can be finally firmly formed on the substrate.

[0152] The present invention enables the reactive functional groups of an organic / inorganic hybrid siloxane copolymer (binder) and a fluorinated (meth)acrylate compound contained in a coating composition to form cross-linking bonds through a curing process. Accordingly, a coating layer comprising the cured product having a mutual network structure can be formed.

[0153] The coating layer manufactured according to the present invention is manufactured through a liquid formulation, thus avoiding the risk of explosion and allowing for free processing. Furthermore, the coating layer not only exhibits excellent light transmittance, hardness, and moisture resistance, but also exhibits minimal yellowing, resulting in superior weatherability. Therefore, the coating layer can be utilized as a material to replace the tempered glass attached to the front surface of solar modules.

[0154] In one specific example, the coating layer may have a thickness of 0.1 to 500 μm. Within this thickness range, visible light transmittance, weather resistance, and durability may be excellent. For example, the coating layer may have a thickness of 1 to 10 μm.

[0155] In one specific example, the coating layer may have an average light transmittance of at least 90% in a wavelength range of 400 nm to 1100 nm, for example, 90 to 100%.

[0156] In one specific example, the coating layer may have a pencil hardness of 3H to 9H. The hardness and durability may be excellent within the above range. For example, the coating layer may have a pencil hardness of 3H, 3.5H, 4H, 4.5H, 5H, 5.5H, 6H, 6.5H, 7H, 7.5H, 8H, 8.5H, or 9H.

[0157] In one specific example, the coating layer may have a yellowing index (△YI) of less than 2% as measured according to KS M ISO 4892-3. Under the above conditions, the coating layer may have excellent yellowing resistance. For example, the coating layer may have a yellowing index of, for example, 0% to 1.95%.

[0158]

[0159] Substrate layer

[0160] The substrate layer (120) is not particularly limited in material as long as it is a transparent plastic film. For example, the substrate layer (120) may be made of a material selected from the group consisting of polyimide, polyester, polyethylene, polyetherimide, polyethylene naphthalate, polyethersulfone, polyethylene terephthalate, polyethylene terephthalate glycol, polycarbonate, polymethyl methacrylate, polymethyl methacrylimide, polyoxymethylene polypropylene, polyphenylene ether, polyphenylene sulfide, polyphenylene sulfone, polystyrene, polyether sulfone, polysulfone, polytetrafluoroethylene, polyurethane, polyvinyl chloride, polyvinylidene fluoride, polybutylene terephthalate, epoxy resin, copolymers thereof, or combinations thereof, but is not limited thereto.

[0161] In one specific example, a uniaxially or biaxially oriented film having excellent transparency and heat resistance, as well as excellent productivity and processability, may be used as a material constituting the substrate layer (120). In one specific example, the substrate layer (120) may have a thickness of 1 to 1000 μm. Under the above conditions, the substrate layer may have excellent optical properties while being lightweight and processable. For example, the substrate layer may have a thickness of 5 to 1000 μm, 10 to 500 μm, 10 to 300 μm, 10 to 200 μm, 20 to 150 μm, or 40 to 100 μm.

[0162]

[0163] barrier layer

[0164] The barrier layer (110) has low oxygen permeability and moisture permeability, and high near-infrared reflectance and mid-infrared emissivity, thereby securing the radiation cooling properties of the laminated film. In one specific example, the barrier layer (110) may include a resin matrix and infrared absorbing particles dispersed in the resin matrix.

[0165] In one specific example, the barrier layer may be formed from a composition for a barrier layer comprising a siloxane-based binder having a repeating structure of the chemical formula 1, a (meth)acrylate compound, a curing agent, cellulose nanofibrils, infrared absorbing particles, and a solvent.

[0166] Hereinafter, the components of the composition for the barrier layer will be described in more detail.

[0167]

[0168] solvent

[0169] The above solvent is used to ensure formability and dispersibility, and its type is not particularly limited. For example, the solvent may include one or more of water, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), butyl cellosolve (BC), methyl cellosolve (MC), ethylene glycol (EG), propylene glycol (PG), N-methyl-2-pyrrolidone (NMP), dimethylacetamide (DMAc), propylene glycol diacetate (PGDA), propylene glycol normal propyl ether (PnP), tetrahydrofuran, toluene, xylene, butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, methanol, ethanol, n-propanol, isopropanol, butanol, butoxyethanol, pentanol, octanol, hexane, heptane, ether, and ketone. The adhesion between the coating layer and the barrier layer can be improved by including the above solvent. For example, water (ultrapure water) can be included.

[0170]

[0171] Siloxane binder

[0172] In one specific example, the siloxane-based binder comprises a repeating structure of the following chemical formula 1:

[0173] [Chemical Formula 1]

[0174]

[0175] (In the above chemical formula 1, the R 1 , R 2 and R 3 are each independently a hydrogen atom, C1-C 20 Alkyl group, C1-C 20 Alkyl amino group, vinyl group, C1-C 20 Alkyl vinyl group, C1-C 20 Alkyl (meth)acrylate group, C3-C 20 Alkyl (meth)acryloxy group, C6-C 20 An aryl group, a sulfonic acid group, and a structure represented by the following chemical formula 1-1, wherein R 1 , R 2 and R 3At least one of them has a structure of the following chemical formula 1-1, wherein R 4 is C1-C 20 Alkyl group, C1-C 10 Alkoxy group, C2-C 20 Alkenyl group, C1-C 20 Alkyl amino group, C1-C 20 Alkyl vinyl group, C3-C 20 Alkyl (meth)acrylate group, C3-C 20 Alkyl (meth)acryloxy group, thiol group, C3-C 20 Alkyl thiol group, glycidyloxy group, C1-C 20 Alkyl glycidyloxy group, epoxy group, C1-C 20 Alkyl epoxy group, C4-C 20 Cycloalkyl epoxy group, C6-C 20 Aryl epoxy group and C3-C 20 A heteroaryl epoxy group is selected, wherein a and b are each 0.1 to 0.9, and a + b = 1.

[0176] [Chemical Formula 1-1]

[0177]

[0178] (In the above chemical formula 1-1, the R 5 and R 6 are each independently C1-C 20 Alkyl group, C1-C 20 Alkyl amino group, hydroxyl group and C1-C 20 Selected from among alkoxy groups, and the above R 7 Silver vinyl group, C1-C 20 Alkyl vinyl group, C3-C 20 Alkyl (meth)acrylate group and C3-C 20 Alkyl (meth)acryloxy group is selected, and * is a connecting moiety).

[0179] In one specific example, R in the chemical formula 1 1 , R 2 and R 3 are each independently a hydrogen atom, C1-C 10A moiety composed of an alkyl group and chemical formula 1-1, wherein R 1 , R 2 and R 3 At least one of them is a moiety composed of chemical formula 1-1, wherein R 4 is C1-C 10 It may be an alkyl group, but is not limited thereto.

[0180] C2-C above 20 The alkenyl group may include, for example, a vinyl group.

[0181] In addition, in the chemical formula 1-1, the R 5 and R 6 are each independently a hydroxyl group or C1-C 10 is an alkoxy group, and the above R 7 Silver C3-C 10 It may be an alkyl (meth)acryloxy group, but is not limited thereto.

[0182] In one specific example, 20 to 60 mol% of the hydroxyl groups, alkoxy groups and / or aryloxy groups forming the side chains of the backbone of the inorganic hybrid siloxane copolymer having the repeating structure of Chemical Formula 1 that functions as the binder may be substituted or modified with a moiety having the structure of Chemical Formula 1-1 via an ether bond. In addition, the siloxane binder, which is an organic-inorganic copolymer having the repeating structure of Chemical Formula 1, may have a weight average molecular weight (Mw) of 1,000 to 20,000 g / mol, but is not limited thereto.

[0183] The constituent unit represented by the mole fraction a in the above chemical formula 1 may be derived from a silane monomer having four hydrolysable alkoxy groups.

[0184] In one specific example, the silane monomer having the four hydrolyzable functional groups may be selected from the group consisting of tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabuthoxysilane, tetraisopropoxysilane, methoxytriethoyxsilane, dimethoxydiethoxysilane, and ethoxytrimethoxysilane, but is not limited thereto.

[0185] Additionally, the constituent unit represented by the mole fraction b in the above chemical formula 1 may be derived from a silane monomer having three hydrolyzable functional groups, namely an alkoxy group. For example, the silane monomers having the three hydrolyzable functional groups are methyltriethoxysilane (MTES), ethyltriethoxysilane (ETES), n-propyltriethoxysilane (PTES), octyltriethoxysilane (OTES), vinyltrimethoxysilane (VTMS), vinyltriethoxysilane (VTES), vinyltriisopropoxysilane (VTIPS), 3-aminopropyltrimethoxysilane (APTMS), 3-aminopropyltriethoxysilane (APTES), 3-(2-Aminoethylamino)propyltrimethoxysilane (AEPTMS), (3-Acryloxypropyl)trimethoxysilane (APTMS), Methacryloxymethyltriethoxysilane (MMS), 3-Methacryloxypropyltrimethoxysilane (MPTMS), 3-Methacryloxypropyltriethoxysilane (MPTES), 3-Mercaptopropyltriethoxysilane (MPTES), 3-Isocyanatopropyltriethoxysilane (It may be selected from the group consisting of, but is not limited to, 2-(3,4-Epoxycyclohexyl)ethyltriethoxysilane (ECETMS), 3-Glycidyloxypropyltrimethoxysilane (GPTMOS), 3-Glycidyloxypropyltriethoxysilane (GPTEOS), Phenyltrimethoxysilane (PTES), (4-chlorophenyl)triethoxysilane (CPTES), and [3-(phenylamino)propyl]trimethoxysilane (PAPTMS).

[0186] Meanwhile, at least one silane-based material can be condensed with a moiety having a structure of Chemical Formula 1-1 on at least some of the side chains constituting the backbone of an inorganic hybrid siloxane copolymer having a repeating structure of Chemical Formula 1. The silane-based material condensed on the side chain of Chemical Formula 1 has at least one hydrolyzable functional group connected to a silicon atom, and at least one vinyl group, C1-C 20 Alkyl vinyl group, C3-C 20 Alkyl (meth)acrylate group and / or C3-C 20 It may have an alkyl (meth)acryloxy group.

[0187] For example, silane-based materials that can be condensed on at least a portion of the side chain of the backbone of an inorganic hybrid siloxane copolymer having a repeating structure of Chemical Formula 1 include vinyltrimethoxysilane (VTMS), vinyltriethoxysilane (VTES), vinyltriiosproposysilane (VTIPS), chloromethylphenylvinylsilane, (3-acryloxypropyl)trimethoxysilane (APTMS), methacryloxymethyltriethoxysilane (MMS), 3-methacryloxypropyltrimethoxysilane (PTMS), It may include, but is not limited to, 3-methacryloxypropyltriethoxysilane (MPTES).

[0188] An organic-inorganic hybrid siloxane copolymer having a repeating structure of Chemical Formula 1 can be manufactured through a polymerization reaction in which a solvent and, if necessary, a catalyst are added to the starting materials, which are silane monomers, to hydrolyze them, induce a condensation reaction, and optionally perform a hydration reaction by adding heating and hydrogen peroxide.

[0189] In one specific example, the polymerization reaction may be performed through a hydrolysis reaction and a condensation reaction by a sol-gel process at a temperature of 25 to 100°C for 2 to 24 hours, but is not limited thereto. At this time, the weight average molecular weight of the ultimately synthesized organic-inorganic hybrid siloxane copolymer can be controlled depending on the amount of polymerization solvent used and the reaction time. By performing the polymerization reaction for 2 to 24 hours, a copolymer having a repeating structure of Chemical Formula 1 and having a weight average molecular weight suitable for use as a binder in a composition for a barrier layer can be prepared.

[0190] In one specific example, the polymerization solvent in which the silane-based starting material is dispersed may be any polymerization solvent capable of mediating a polymerization reaction between the starting materials. Typically, the polymerization step may be conducted in a soluble solvent capable of forming a homogeneous solution.

[0191] In one specific example, the polymerization solvent may be selected from the group consisting of aliphatic hydrocarbon solvents, ether solvents, acetate solvents, alcohol solvents, ketone solvents, amide solvents, silicone solvents, and combinations thereof. For example, the polymerization solvent may include, but is not limited to, one or more of propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), butyl cellosolve (BC), methyl cellosolve (MC), ethylene glycol (EG), propylene glycol (PG), N-methyl-2-pyrrolidone (NMP), dimethylacetamide (DMAc), propylene glycol diacetate (PGDA), propylene glycol normal propyl ether (PnP), tetrahydrofuran, toluene, xylene, butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, methanol, ethanol, n-propanol, isopropanol, butanol, butoxyethanol, pentanol, octanol, hexane, heptane, ethers, and ketones.

[0192] In the above polymerization reaction, as long as the aforementioned starting materials can be uniformly dissolved in the polymerization solvent, the content of the polymerization solvent is not particularly limited. In one exemplary aspect, the amount of the polymerization solvent used in the polymerization reaction can be adjusted to a range of about 5 to 60 parts by weight, preferably about 20 to 50 parts by weight, based on the total content of each reactant including the polymerization solvent.

[0193] Additionally, acid catalysts and / or basic catalysts may be used to promote hydrolysis and / or condensation reactions. For example, these catalysts may be used in an aqueous solution form.

[0194] For example, the acid catalyst may include, but is not limited to, one or more of inorganic acids such as hydrochloric acid, sulfuric acid, and nitric acid; and organic acids such as toluenesulfonic acid, formic acid, acetic acid, butyric acid, palmitic acid, oxalic acid, and tartaric acid. In addition, the basic catalyst may include, but is not limited to, alkali metal hydroxides such as sodium hydroxide, lithium hydroxide, and potassium hydroxide; alkaline earth metal compounds such as barium hydroxide, barium hydroxide monohydrate, barium hydroxide octahydrate, calcium hydroxide, and magnesium hydroxide; and quaternary ammonium compounds such as tetramethylammonium hydroxide, tetramethylammonium chloride, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, tetrabutylammonium fluoride, benzyltrimethylammonium hydroxide, and benzyltriethylammonium hydroxide. It may include, but is not limited to, one or more of ammonia, triethylamine, tripropylamine, n-butylamine, di-n-butylamine, tri-n-butylamine, imidazole, pyridine, 3-methylpyridine, 4-dimethylaminopyridine, N,N-diisopropylethylamine, and ammonium perchlorate.

[0195] For example, the barrier layer includes a repeating unit backbone represented by the chemical formula 1, and at least one residue R bonded to silicon (Si) of the chemical formula 1. 1 ~R 7It may be an organic-inorganic hybrid copolymer containing moieties such as a hydroxyl group, an alkyl (meth)acrylate group, etc.

[0196] The siloxane binder of the above chemical formula 1 has CO stretching vibration and can have high emissivity in the wavelength of the mid-wavelength infrared region.

[0197] In one specific example, the siloxane-based binder may be included in an amount of 5 to 60 parts by weight based on 100 parts by weight of the solvent. When included in the above content range, the composition for the barrier layer may have excellent mixing and dispersibility, excellent visible light transmittance and mid-infrared radiation efficiency, and excellent water repellency, durability, and interlayer adhesion. For example, it may be included in an amount of 5 to 50 parts by weight, 10 to 50 parts by weight, or 10 to 40 parts by weight. For example, the siloxane-based binder may be included in an amount of 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 or 60 parts by weight per 100 parts by weight of the solvent.

[0198]

[0199] (meth)acrylate compounds

[0200] In one specific example, the barrier layer composition may further comprise a (meth)acrylate compound. The (meth)acrylate compound may comprise a non-fluorinated (meth)acrylate compound. The non-fluorinated (meth)acrylate compound may comprise a non-fluorinated (meth)acrylate monomer and / or a non-fluorinated (meth)acrylate oligomer.

[0201] For example, the (meth)acrylate compound may include a monofunctional (meth)acrylate compound and / or a polyfunctional (meth)acrylate compound.

[0202] In one specific example, the monofunctional (meth)acrylate compound is C1~C 20 Alkyl group, C2~C 20 Alkenyl group, C2~C 20 Alkynyl group, C1~C 20 Alkoxy group, C1~C 20 Alkoxyalkyl group, C1~C 20 Aliphatic (meth)acrylate compounds substituted with alkoxyallyl groups, epoxy groups, etc.; unsubstituted or C1~C 10 Alkyl group, C2~C 10 Alkenyl group, C2~C 10 alkynyl group of, or C1-C 10 Cycloalkyl (meth)acrylate compounds having C5-C8 groups substituted with alkoxy groups; unsubstituted or C1-C 10 Alkyl group, C2-C 10 Alkenyl group, C2-C 10 alkynyl group of, or C1-C 10 C5~C substituted with an alkoxy group 20 Aryl (meth)acrylate compounds; C1~C 20 It may be selected from the group consisting of allyl alkoxylate compounds having an alkoxy group; urethane-based (meth)acrylate-based compounds and combinations thereof.

[0203] In one specific example, the C2~C 20 The alkenyl (meth)acrylate compound may be selected from the group consisting of butadiene (meth)acrylate, hexadiene (meth)acrylate, octadiene (meth)acrylate, combinations thereof, and oligomers thereof, but is not limited thereto.

[0204] In one specific example, the above C1~C 20The alkoxy (meth)acrylate compound may be selected from the group consisting of, but is not limited to, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, ethylene glycol methyl ether (meth)acrylate, ethylene glycol phenyl ether (meth)acrylate, diethylene glycol methyl ether (meth)acrylate, diethylene glycol ethyl ether (meth)acrylate, 1,3-butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, combinations thereof, and oligomers thereof.

[0205] In one specific example, the above C1~C 20 The alkoxyalkyl (meth)acrylate compound may be selected from the group consisting of, but is not limited to, 2-hydroxy-ethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-hydroxy-propyl (meth)acrylate, 2-hydroxy-butyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, trimethoxybutyl (meth)acrylate, combinations thereof, and oligomers thereof.

[0206] In one specific example, the epoxy (meth)acrylate compound may be selected from the group consisting of epoxy (meth)acrylate, epoxycyclohexylmethyl (meth)acrylate, glycidyl (meth)acrylate, methyl glycidyl (meth)acrylate, combinations thereof, and oligomers thereof, but the present invention is not limited thereto.

[0207] In one specific example, the C5-C8 cycloalkyl (meth)acrylate compound may be selected from the group consisting of, but is not limited to, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, isobornyl (meth)acrylate, combinations thereof, and oligomers thereof.

[0208] In one specific example, the C5-C20 The aryl (meth)acrylate compound may be selected from the group consisting of benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, combinations thereof, and oligomers thereof, but is not limited thereto.

[0209] In one specific example, the allyl alkoxylate compound may be selected from the group consisting of allyl propoxylate, allyl monopropoxylate, combinations thereof, and oligomers thereof, but is not limited thereto.

[0210] In one specific example, the urethane-based (meth)acrylate-based compound may be a radical polymerizable unsaturated group-containing oligomer or prepolymer obtained by reacting a polyisocyanate-based compound having a plurality of isocyanate groups with a polyol-based compound having a plurality of hydroxyl groups, and then reacting the polyisocyanate-based compound with a (meth)acrylate-based compound containing hydroxyl groups.

[0211] In one specific example, the polyisocyanate compound may be selected from the group consisting of, but is not limited to, 2,4-trylene diisocyanate and isomers thereof, diphenylmethane diisocyanate, hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, and combinations thereof.

[0212] In one specific example, the polyol compound may be a polyhydroxy compound selected from the group consisting of polycarbonate polyols, polyester polyols, polyether polyols, polycaprolactone polyols, and combinations thereof. For example, the polyhydroxy compound can be selected from the group consisting of glycerin-ethylene oxide adduct, glycerin-propylene oxide adduct, glycerin-tetrahydrofuran adduct, glycerin-ethylene oxide-propylene oxide adduct, trimethylolpropane-ethylene oxide adduct, trimethylolpropane-propylene oxide adduct, trimethylolpropane-tetrahydrofuran adduct, trimethylolpropane-ethylene oxide-propylene oxide adduct, dipentaerythritol-ethylene oxide adduct, dipentaerythritol-propylene oxide adduct, dipentaerythritol-tetrahydrofuran adduct, dipentaerythritol-ethylene oxide-propylene oxide adduct, and combinations thereof.

[0213] In one specific example, the polyol compound may be a polyhydric alcohol. For example, the polyhydric alcohol may be selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 2-methyl-1,3-propanediol, 1,3-butanediol, an adduct of bisphenol A and propylene oxide or ethylene oxide, 1,2,3,4-tetrahydroxybutane, glycerin, trimethylolpropane, 1,2-cyclohexane glycol, 1,3-cyclohexane glycol, 1,4-cyclohexane glycol, paraxylene glycol, bicyclohexyl-4,4-diol, 2,6-decarin glycol, 2,7-decarin glycol, and combinations thereof.

[0214] In one specific example, the hydroxyl group-containing (meth)acrylate compound may be selected from the group consisting of 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, tris(hydroxyethyl)isocyanuric acid di(meth)acrylate, pentaerythritol tri(meth)acrylate, and combinations thereof, but is not limited thereto.

[0215] In one specific example, the multifunctional (meth)acrylate compound may be added for the purpose of improving solvent resistance, hardness, etc. For example, the multifunctional (meth)acrylate compound may be selected from the group consisting of pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, t-butylpropane tri(meth)acrylate, combinations thereof, and oligomers thereof, but is not limited thereto.

[0216] In one specific example, the (meth)acrylate compound is diethylene glycol diacrylate, diethylene glycol dimethacrylate, ethylene glycol dimethacrylate, dipropylene glycol diacrylate, dipropylene glycol dimethacrylate, ethylene glycol divinyl ether, ethoxylated trimethylolpropane triacrylate, diethylene glycol divinyl ether, triethylene glycol dimethacrylate, dipentaerythritol pentaacrylate, trimethylolpropane It may include at least one of trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, propoxylated trimethylolpropane triacrylate, propoxylated trimethylopropane triacrylate, poly(ethylene glycol) diacrylate (PA1), and poly(ethylene glycol) dimethacrylate.When the above (meth)acrylate compound is included, the mid-infrared radiation efficiency of the barrier layer can be improved without deterioration, while durability and moisture and oxygen barrier properties can be excellent.

[0217] In one specific example, the (meth)acrylate-based compound may be included in an amount of 1 to 20 parts by weight based on 100 parts by weight of the solvent. When included in the above content range, the occurrence of defects such as cracks in the barrier layer may be prevented, while the hardness may be excellent. For example, the (meth)acrylate-based compound may be included in an amount of 1 to 15 parts by weight, 1 to 10 parts by weight, or 3 to 10 parts by weight. For example, the (meth)acrylate-based compound may be included in an amount of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 parts by weight based on 100 parts by weight of the solvent.

[0218]

[0219] infrared absorbing particles

[0220] The above infrared absorbing particles may be included to improve radiant cooling performance by absorbing wavelengths in the infrared region when light is incident on the laminated film.

[0221] In one specific example, the infrared absorbing particles may include at least one of metal oxide and metal nitride particles.

[0222] For example, the infrared absorbing particles may include one or more of silica (SiO2), titanium dioxide (TiO2), alumina (Al2O3), zirconium oxide (ZrO2), and silicon nitride (Si3N4).

[0223] For example, the infrared absorbing particles may include titanium dioxide capable of absorbing light in the infrared region. The titanium dioxide may undergo photodecomposition when absorbing light in the infrared region, but the photodecomposition of the titanium dioxide can be prevented when forming a barrier layer using the barrier layer composition of the present invention.

[0224] In one specific example, the infrared absorbing particles may be spherical, polyhedral or irregularly shaped. For example, they may be spherical.

[0225] In one specific example, the infrared absorbing particles may have an average size of 10 nm to 20 μm. The size may refer to the maximum length or diameter of the infrared absorbing particles. Under the above conditions, the particles may have excellent mixing and dispersibility, absorb light in the infrared region, and exhibit excellent emissivity in the mid-infrared region, thereby exhibiting excellent radiation cooling properties.

[0226] In one specific example, the barrier layer may contain 0.1 to 30 parts by weight of the infrared absorbing particles relative to 100 parts by weight of the solvent. Under the above conditions, the composition may have excellent mixing and dispersibility, excellent radiation cooling function, and excellent power generation efficiency and long-life characteristics of the solar cell element when forming a solar module. For example, the infrared absorbing particles may be contained in an amount of 0.5 to 25 parts by weight, 0.5 to 20 parts by weight, 1 to 15 parts by weight, 1 to 10 parts by weight, or 1 to 6 parts by weight. For example, the infrared absorbing particles may be included in an amount of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or 30 parts by weight per 100 parts by weight of the solvent.

[0227]

[0228] Cellulose nanofibrils

[0229] The above cellulose nanofibrils (CNFs) can be manufactured by processing cellulose fiber material into nano-sized particles (nanofibrillars). For example, cellulose nanofibrils can be manufactured by nanofibrillating wood pulp.

[0230] The above cellulose nanofibrils include fibril units including crystalline and amorphous regions, and the cellulose nanofibrils have a significantly increased specific surface area compared to cellulose, and contain functional groups such as hydroxyl groups (-OH) on the surface, so that a barrier layer having a dense network structure can be formed through hydrogen bonding between the cellulose nanofibrils and bonding with components of a barrier layer composition such as the cellulose nanofibrils and a siloxane-based binder.

[0231] When the above cellulose nanofibrils are included, the barrier layer can have improved moisture and oxygen barrier properties, excellent durability, heat resistance and flexibility, and excellent interlayer adhesion.

[0232] For example, the cellulose nanofibrils may have an average diameter of 1 nm to 50 μm or less, an average fiber length of 5 nm to 10 μm or less, and an aspect ratio of 5 to 300. Under the above conditions, the barrier layer may have improved barrier properties against moisture and oxygen, and the barrier layer may have excellent durability, heat resistance, and flexibility, and excellent interlayer adhesion.

[0233] In one specific example, the cellulose nanofibrils may be included in an amount of 2 to 40 parts by weight based on 100 parts by weight of the solvent. When included in the above content range, the barrier layer may have excellent moisture and oxygen barrier properties, excellent durability, heat resistance, flexibility, and excellent weather resistance. For example, the content may be 5 to 40 parts by weight, 5 to 35 parts by weight, 5 to 25 parts by weight, or 10 to 25 parts by weight. For example, the cellulose nanofibrils may be included in an amount of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39 or 40 parts by weight per 100 parts by weight of the solvent.

[0234] In one specific example, the barrier composition may include the (meth)acrylate compound and the cellulose nanofibrils in a weight ratio of 1:0.5 to 1:5. When included in the above weight ratio range, the composition for the barrier layer has excellent mixing and dispersibility, improves barrier properties against moisture and oxygen, and can simultaneously have excellent mechanical properties such as mid-infrared radiation properties and durability. For example, it may be included in a weight ratio of 1:2 to 1:4.

[0235] In one specific example, the barrier composition may include the infrared absorbing particles and cellulose nanofibrils in a weight ratio of 1:2 to 1:8. When included in the above weight ratio range, the composition for the barrier layer may have excellent mixing and dispersibility, improve barrier properties against moisture and oxygen, and simultaneously have excellent mechanical properties such as durability. For example, it may be included in a weight ratio of 1:2 to 1:7 or 1:3 to 1:6.

[0236]

[0237] hardener

[0238] The composition for the barrier layer may include at least one of a photopolymerization initiator and a thermal curing agent as a curing agent. The photopolymerization initiator may induce a photopolymerization reaction of the siloxane-based binder and the (meth)acrylate-based compound in the barrier layer composition by irradiation with an appropriate light source such as ultraviolet (UV) rays.

[0239] In one specific example, the photopolymerization initiator is 1) an acetophenone-based photopolymerization initiator such as 2,2'-diethoxyacetophenone, 2,2'-dibutoxyacetophenone, 2-hydroxy-2-methylpropiophenone, pt-butyltrichloroacetophenone, pt-butyldichloroacetophenone, 4-chloroacetophenone, 2,2'-dichloro-4-phenoxyacetophenone, 2) benzophenone, 4,4'-dimethylaminobenzophenone, 4,4'-dichlorobenzophenone, 3,3'-dimethyl-2-methoxybenzophenone, 4-phenyl benzophenone, hydroxy benzophenone, acrylated benzophenone, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethyl 3) Thioxanthone-based photopolymerization initiators such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropyl thioxanthone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-3-yl]-1-(O-acetyloxime), 2,4-diethyl thioxanthone, 2,4-diisopropyl thioxanthone, 2-chloro thioxanthone, 2-dodecyl thioxanthone, 2,4-dimethyl thioxanthone, 2,4-diethyl thioxanthone, etc. 4) Benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin Benzoin-based photopolymerization initiators such as isobutyl ether, benzyl dimethyl ketal, and methyl benzoyl formate, 5) 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis(trichloromethyl)-s-triazine, 2,4-trichloromethyl-6-triazine, bis(trichloromethyl)-6-styryl-s-triazine, 2-4-trichloromethyl(piperonyl)-6-triazine, 2-4-trichloromethyl(4'-methoxystyryl)-6-triazine, 2-(3',4'-dimethoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4'-methoxy naphthyl)-4,6-bis(trichloromethyl)-s-triazine, 2,4-Trichloromethyl-4-methylnaphthyl-6-triazine, 2-(p-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-p-methoxystyryl-4,6-bistrichloromethyl-s-triazine, 2-piphenyl-4,6-bis(trichloromethyl)-s-triazine, 2,4-Bistrichloromethyl-6-p-methoxystyryl-s-triazine and other triazine photopolymerization initiators, 6) diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl(2,4,6-trimethylbenzoyl)phenylphosphinate, 2,2-bis(2-chlorophenyl)-4,4,5,5-tetraphenyl-1,2-biimidazole and other photopolymerization initiators may be included.

[0240] For example, the photopolymerization initiators sold commercially include Irgacure 369 (2-Benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, hereinafter, manufactured by Ciba Specialty Chemical Co.), Irgacure 651 (2,2-Dimethoxy-1,2-diphenylethan-1-one), Irgacure 907 (2-Methyl-1-(4-methyl thio) phenyl-2-(4-morpholinyl)-1-propanone), Irgacure 819 (Bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide), Irgacure 184 (1-Hydroxy-cyclohexyl-phenyl-ketone), Irgacure 250 (Iodonium, (4-methylphenyl)[4-(2-methylpropyl) phenyl]-, hexafluorophosphate(1-)), Irgacure 127 (2-Hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl}-2-methyl-propan-1-one), etc.

[0241] The above-mentioned thermosetting agent may be a latent thermosetting agent that does not cure at low temperatures but cures at high temperatures. The latent thermosetting agent may include at least one of an amine-based, imidazole-based, dihydrazide-based, and organic peroxide-based thermosetting agent.

[0242] In one specific example, the curing agent may be included in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the solvent. When included in the above range, the mixing property and curing reaction speed of the composition can be easily controlled, thereby providing excellent curing efficiency and preventing defects such as yellowing of the barrier layer. For example, the curing agent may be included in an amount of 0.1 to 8 parts by weight, 0.1 to 6 parts by weight, or 0.1 to 4 parts by weight. For example, the curing agent may be included in an amount of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 parts by weight based on 100 parts by weight of the solvent.

[0243]

[0244] The barrier layer can be formed by a conventional method. For example, the barrier layer can be formed using a composition for a barrier layer including a siloxane-based binder represented by the following chemical formula 1, a (meth)acrylate compound, a curing agent, cellulose nanofibrils, ultraviolet-absorbing particles, and a solvent. The composition for a barrier layer can be formed by applying it to a substrate or the like and then curing it by a known method. The method for applying the composition for a barrier layer on the substrate is not particularly limited. For example, spin coating such as a center drop spin method, roll coating, spray coating, bar coating, knife coating, casting coating, dip coating, gravure coating, slit coating using a slit nozzle such as a discharge nozzle-type coating, or a dispensing method can be used, and two or more methods can be combined to form the composition for a barrier layer by applying it to one surface of the substrate, coating layer, or adhesive layer, and curing it by a known method.

[0245] In one specific example, the barrier layer may have a thickness of 10 μm to 3 mm. Within this thickness range, the barrier layer may exhibit excellent mid-infrared emissivity, weather resistance, and durability. For example, the barrier layer may have a thickness of 20 μm to 1 mm.

[0246] In one specific example, the barrier layer has an oxygen permeability of 0.05 cc / m 2 ·day or less, and moisture permeability is 0.15 g / m 2 ·day or less. Under the above conditions, the moisture barrier properties of the laminated film can be excellent. For example, the oxygen permeability is 0 to 0.03 cc / m. 2 ·day, and moisture permeability is 0~0.09 g / m 2 ·It could be day.

[0247] For example, the above barrier layer has an oxygen permeability of 0 to 0.03 cc / m measured under conditions of 36±2℃, 100RH% relative humidity and 24 hours using a test device Permatran-W 3 / 33 MA (Mocon, USA) in accordance with ASTM F1249 or the above standard. 2 ·day, and the moisture permeability is 0.15 g / m 2 ·May be less than a day.

[0248] In one specific example, the coating layer and barrier layer may be formed at a thickness ratio of 1:0.5 to 1:20. Under the above thickness ratio conditions, the laminated film may exhibit excellent moisture and oxygen barrier properties, while also exhibiting excellent visible light transmittance and near-infrared radiation efficiency. For example, the film may be formed at a thickness ratio of 1:2 to 1:10.

[0249]

[0250] adhesive layer

[0251] In one specific example, the laminated film may further include an adhesive layer formed on the lower surface of the barrier layer. The adhesive layer may be formed from a composition for an adhesive layer comprising a siloxane-based binder represented by the following chemical formula 2, a surface treatment filler, and a solvent.

[0252] For example, the adhesive layer can be formed from a composition for an adhesive layer containing 100 parts by weight of a solvent, 1 to 10 parts by weight of a siloxane-based binder represented by the following chemical formula 2, and 0.1 to 5 parts by weight of a surface treatment filler.

[0253] The present invention can maximize radiation cooling efficiency by further forming an adhesive layer between the barrier layer and the solar cell element, thereby reducing the thermal conduction resistance between the laminated film and the solar cell element.

[0254] Hereinafter, the composition for the adhesive layer will be described in detail.

[0255]

[0256] solvent

[0257] The solvent is used to ensure the formability and dispersibility of the composition for the adhesive layer, and its type is not particularly limited. For example, the solvent may include one or more of water, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), butyl cellosolve (BC), methyl cellosolve (MC), ethylene glycol (EG), propylene glycol (PG), N-methyl-2-pyrrolidone (NMP), dimethylacetamide (DMAc), propylene glycol diacetate (PGDA), propylene glycol normal propyl ether (PnP), tetrahydrofuran, toluene, xylene, butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, methanol, ethanol, n-propanol, isopropanol, butanol, butoxyethanol, pentanol, octanol, hexane, heptane, ether, and ketone. When the above solvent is included, the adhesion of the coating layer to the substrate can be improved. For example, water (ultrapure water) can be included.

[0258]

[0259] Siloxane binder

[0260] The above siloxane-based binder can be represented by the following chemical formula 2:

[0261] [Chemical Formula 2]

[0262]

[0263] (In the above chemical formula 2, the R 8 , R 9 , R 10 and R 11Each independently represents a hydrogen atom, a hydroxyl group, a mercapto group, a sulfonic acid group, and C1-C 20 Alkyl group, C1-C 10 Alkoxy group, C1-C 20 Alkyl amino group, vinyl group, C1-C 20 Alkyl vinyl group, C1-C 20 Alkyl (meth)acrylate group, C3-C 20 Alkyl (meth)acryloxy group or C6-C 20 is selected from among aryl groups, wherein c and d are each 1 to 100, and c and d are included in a weight ratio of 1:0.1 to 1:10.

[0264] For example, the adhesive layer has a repeating unit backbone represented by the chemical formula 2, and at least one residue R bonded to silicon (Si) of the chemical formula 2. 8 ~R 11 It may be an organic-inorganic hybrid copolymer containing a moiety such as a hydroxyl group (-OH, alcohol).

[0265] In one specific example, the C1-C 20 Alkyl groups include methyl, ethyl, normal propyl, isopropyl, normal butyl, isobutyl, tert-butyl, normal pentyl, isopentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tetradecyl, octadecyl, and icosanyl.

[0266] In one specific example, the C1-C 20 Alkoxy groups include methoxy, ethoxy, propoxy, butoxy, and phenoxy groups.

[0267] In one specific example, the C1-C 20 Alkyl vinyl groups include methyl vinyl group, ethyl vinyl group, propyl vinyl group, butyl vinyl group, hexyl vinyl group, heptyl vinyl group, dodecyl vinyl group, octadecyl group, and icosyl vinyl group.

[0268] In one specific example, the C1-C 20Examples of the alkyl (meth)acrylate group include a methyl (meth)acrylate group, an ethyl (meth)acrylate group, a propyl (meth)acrylate group, an octyl (meth)acrylate group, a decyl (meth)acrylate group, a dodecyl (meth)acrylate group, a tridecyl (meth)acrylate group, a tetradecyl (meth)acrylate group, a pentadecyl (meth)acrylate group, a hexadecyl (meth)acrylate group, and an octadecyl (meth)acrylate group.

[0269] In one specific example, the C3-C 20 Alkyl (meth)acryloxy groups include propyl (meth)acryloxy and butyl (meth)acryloxy.

[0270] In one specific example, the moieties c and d may be included in a weight ratio of 1:0.1 to 1:10. When the moieties c and d are included in the weight ratio range, the durability and mechanical properties of the siloxane-based binder may be excellent, and the interlayer adhesive strength of the adhesive layer may be excellent. For example, the moieties c and d may be included in a weight ratio of 1:2 to 1:6.

[0271] In one specific example, the siloxane-based binder represented by the above chemical formula 2 may have a weight average molecular weight (Mw) of 1,000 to 50,000 g / mol. Within the above weight average molecular weight range, the interlayer adhesion, durability, and mechanical properties of the adhesive layer may be excellent.

[0272] In one specific example, the siloxane-based binder may be included in an amount of 1 to 10 parts by weight based on 100 parts by weight of the solvent. When included in the above content range, the composition for the adhesive layer may have excellent mixing and dispersibility, and the durability and interlayer adhesion of the adhesive layer may be excellent. For example, the siloxane-based binder may be included in an amount of 1 to 8 parts by weight or 1 to 5 parts by weight. For example, the siloxane-based binder may be included in an amount of 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 parts by weight based on 100 parts by weight of the solvent.

[0273]

[0274] Surface treatment filler

[0275] The above surface treatment filler may be included to improve the surface energy of the adhesive layer. The adhesive layer may have its surface energy increased by the increase in surface area due to the surface treatment filler and the large number of hydroxyl (-OH) groups on the surface.

[0276] The above surface treatment filler can be manufactured by surface treating the filler with a surface treatment agent. In one specific example, the surface treatment agent may include a silane compound.

[0277] In one specific example, the silane compound may include one or more of methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, decyltrimethoxysilane, glycidoxypropyl trimethoxysilane, hexamethyldisiloxane, trimethylmethoxysilane, ethyltrimethoxysilane, trimethylethoxysilane, mercaptopropyl trimethoxysilane, N-(2-aminoethyl)-3-aminopropyl trimethoxysilane, and dimethyldiethoxysilane. Under the above conditions, the surface energy increasing effect of the adhesive layer is excellent, and the interlayer adhesion and durability may be excellent.

[0278] The above filler may include, but is not limited to, one or more of silica, titanium dioxide, zirconium oxide, boron nitride (BN), magnesium oxide (MgO), calcium carbonate (CaCO3), and alumina.

[0279] In one specific example, the surface treatment filler may be spherical, polyhedral, or irregular in shape. For example, it may be spherical.

[0280] In one specific example, the surface treatment filler may have an average size of 10 nm to 0.1 μm. The size may refer to the maximum length or diameter of the surface treatment filler. Under the above conditions, the composition for the adhesive layer may have excellent mixing and dispersibility, an excellent surface energy enhancement effect, and excellent durability and interlayer adhesion of the adhesive layer.

[0281] For example, the adhesive layer may have a surface energy of 50 dyne / cm or more. For example, it may be 70 dyne / cm or more. Under the above conditions, the interlayer adhesion may be excellent. For example, the adhesive layer may have a water contact angle of 15 degrees or less. Under the above conditions, the surface energy may be high and the interlayer adhesion may be excellent.

[0282] In one specific example, the surface treatment filler may be included in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the solvent. When included in the above content range, the composition for the adhesive layer may have excellent mixing and dispersibility, and the durability and interlayer adhesion of the adhesive layer may be excellent. For example, the surface treatment filler may be included in an amount of 0.1 to 3 parts by weight or 0.1 to 1 part by weight. For example, the surface treatment filler may be included in an amount of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, or 5 parts by weight based on 100 parts by weight of the solvent.

[0283] The method for applying the composition for the adhesive layer on the barrier layer is not particularly limited. For example, a method such as spin coating, roll coating, spray coating, bar coating, knife coating, casting coating, dip coating, gravure coating, slit coating using a slit nozzle, such as a central drop spin method, or a dispensing method can be used, and two or more methods can be combined to apply the coating composition on one surface of the barrier layer or the solar cell element and harden it by a known method to form the composition.

[0284] In one specific example, the adhesive layer may have a thickness of 0.05 to 10 μm. Within this thickness range, the interlayer adhesion, weather resistance, and durability may be excellent. For example, the barrier layer may have a thickness of 0.01 to 0.5 μm.

[0285] In one specific example, the adhesive layer may have a 180° peel strength of 5.0 kgf / 25 mm or more as measured in accordance with ASTM D 3330. For example, it may be 5.1 to 10.0 kgf / 25 mm. The 180° peel strength may be measured under a separation speed condition of, for example, 300 mm / min.

[0286] In one specific example, the laminated film may have an average surface roughness (Ra) of 0.05 to 0.25 μm. For example, the laminated film may have an average surface roughness (Ra) of 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.21, 0.22, 0.23, 0.24, or 0.25 μm.

[0287] In one specific example, the laminated film has an oxygen permeability of 0.3 cc / m 2 ·day or less, and moisture permeability is 0.5 g / m 2 ·day or less. Under the above conditions, the moisture barrier properties of the laminated film can be excellent.

[0288] In one specific example, the laminated film has an oxygen permeability of 0.3 cc / m measured under conditions of 36±2℃, 100RH% relative humidity and 24 hours using a test device Permatran-W 3 / 33 MA (Mocon, USA) in accordance with ASTM F1249 or in accordance with the above standard. 2 ·day or less, and moisture permeability is 0.5g / m 2 ·It can be less than 24 hours. For example, moisture permeability is 0~0.3g / m 2 ·It can be 24 hours. Under the above conditions, the moisture barrier properties of the laminated film can be excellent.

[0289] In one specific example, the laminated film may have an average light transmittance of at least 90% in a wavelength range of 400 nm to 1100 nm, for example, 90 to 100% or 91 to 100%.

[0290]

[0291] Method for manufacturing laminated film for double-sided light-receiving solar modules

[0292] Another aspect of the present invention relates to a method for manufacturing a laminated film for the double-sided light-receiving solar module. In one specific example, the method for manufacturing a laminated film includes the step of providing a laminated film in which a coating layer, a substrate layer, and a barrier layer are sequentially formed; wherein the coating layer has a surface with irregularities and is formed from a coating composition comprising a siloxane-based binder having a repeating structure represented by the following chemical formula 1, a fluorinated (meth)acrylate compound, a curing agent, and inorganic particles:

[0293] [Chemical Formula 1]

[0294]

[0295] (In the above chemical formula 1, the R 1 , R 2 and R 3 are each independently a hydrogen atom, C1-C 20 Alkyl group, C1-C 20 Alkyl amino group, vinyl group, C1-C 20 Alkyl vinyl group, C1-C 20 Alkyl (meth)acrylate group, C3-C 20 Alkyl (meth)acryloxy group, C6-C 20 An aryl group, a sulfonic acid group, and a structure represented by the following chemical formula 1-1, wherein R 1 , R 2 and R 3 At least one of them has a structure of the following chemical formula 1-1, wherein R 4 is C1-C 20 Alkyl group, C1-C 10 Alkoxy group, C2-C 20 Alkenyl group, C1-C 20 Alkyl amino group, C1-C 20 Alkyl vinyl group, C3-C 20 Alkyl (meth)acrylate group, C3-C 20 Alkyl (meth)acryloxy group, thiol group, C3-C 20Alkyl thiol group, glycidyloxy group, C1-C 20 Alkyl glycidyloxy group, epoxy group, C1-C 20 Alkyl epoxy group, C4-C 20 Cycloalkyl epoxy group, C6-C 20 Aryl epoxy group and C3-C 20 A heteroaryl epoxy group is selected, wherein a and b are each 0.1 to 0.9, and a + b = 1.

[0296] [Chemical Formula 1-1]

[0297]

[0298] (In the above chemical formula 1-1, the R 5 and R 6 are each independently C1-C 20 Alkyl group, C1-C 20 Alkyl amino group, hydroxyl group and C1-C 20 Selected from among alkoxy groups, and the above R 7 Silver vinyl group, C1-C 20 Alkyl vinyl group, C3-C 20 Alkyl (meth)acrylate group and C3-C 20 Alkyl (meth)acryloxy group is selected, and * is a connecting moiety).

[0299] In one specific example, the coating layer may be formed by applying and curing a coating composition on one surface of the substrate layer, and the barrier layer may be formed by applying and curing a composition for a barrier layer on the other surface of the substrate layer.

[0300] The composition for the above-mentioned substrate layer, coating composition and barrier layer can be the same as those described above, so a detailed description thereof will be omitted.

[0301] In one specific example, an adhesive layer may be further formed on one surface of the barrier layer. The adhesive layer may be formed by applying and curing an adhesive layer composition on one surface of the barrier layer. The adhesive layer composition may be the same as described above.

[0302]

[0303] Solar module comprising laminated film for double-sided photovoltaic module

[0304] Another aspect of the present invention relates to a solar module including the laminated film for the double-sided light-receiving solar module.

[0305] FIG. 2 illustrates a solar module according to one specific example of the present invention. Referring to FIG. 2, the solar module (1000) includes a solar cell element (200); and the aforementioned laminated films (100, 101) formed on both sides of the solar cell element (200); and the laminated films (100, 101) each include a coating layer (130, 131), a substrate layer (120, 121), and a barrier layer (110, 111) formed sequentially, and the barrier layers (110, 111) of the laminated films (100, 101) are laminated on both sides of the solar cell element (200), respectively.

[0306] Although not shown in the above drawing 2, an adhesive layer is formed on each of the lower surfaces of the barrier layers (110, 111), and both sides of the solar cell element (200) can be in contact with the adhesive layer of the laminated film (100, 101).

[0307] The solar module (1000) of the present invention can further increase the transmittance compared to a laminated film attached to the cross-section of a solar cell element (200) and maximize the efficiency of the solar module through a light trapping effect.

[0308] The solar module (1000) of the present invention has excellent transmittance for wavelengths in the visible light range when light is incident, and can have excellent reflection efficiency for wavelengths in the near-infrared range and radiation efficiency for wavelengths in the mid-infrared range. Light of visible light wavelength incident on the laminated film is transmitted, light of near-infrared wavelength is reflected, and light of mid-infrared wavelength is radiated, so that heat dissipation and radiative cooling efficiency are excellent, and a decrease in solar power generation efficiency can be prevented even during long-term operation. In addition, selective radiative cooling occurs in the laminated film (100) by infrared radiation, so that the surface of the laminated film (100) is cooled, and the heat of the solar cell element having a relatively high temperature can move to the laminated film having a relatively low surface temperature.

[0309] The laminated film of the present invention not only has excellent light transmittance, hardness, weather resistance, and moisture permeability, but also has excellent lightness due to being lighter than glass, so it can be used as a material to replace glass on the front surface of a solar cell element.

[0310] In addition, the laminated film of the present invention has excellent barrier properties against moisture and dust, which are factors that reduce the lifespan of solar modules, and thus can be used for high-efficiency window-type solar modules such as building windows and exterior walls. In the case of the conventional structural film manufacturing process, a separate frame is required for pattern formation, whereas the present invention can form a structural film using only the coating composition. In addition, it has the ease of process because it is possible to form unevenness on the film surface by applying inorganic particles rather than a complex process such as nanoimprinting, and it can have the effect of the invention being formed with a single process of forming a single layer rather than a multilayer.

[0311] In particular, the present invention can maximize the radiation cooling efficiency by further forming an adhesive layer between the barrier layer and the solar cell element, thereby reducing the thermal conduction resistance between the laminated film and the solar cell element. The present invention has an excellent temperature reduction effect of the solar cell element both during the day and at night compared to a case where the laminated film is not attached, and by applying a laminated film with excellent radiation cooling characteristics, the temperature of the solar module body is lowered without separate energy, and as a result, the solar module can secure excellent current efficiency and solar reliability.

[0312]

[0313] Hereinafter, the structure and operation of the present invention will be described in more detail through preferred embodiments. However, these are presented as preferred examples of the present invention and should not be construed as limiting the present invention in any way. Details not described herein are technically feasible to those skilled in the art, and therefore, their description will be omitted.

[0314]

[0315] Synthetic example

[0316] Synthesis Example 1: Synthesis of an organic-inorganic hybrid siloxane copolymer (siloxane binder) for a coating layer.

[0317] Propylene glycol monomethyl ether acetate (101.9 g), tetraethoxysilane (0.9 mol, 189.4 g), and methyltrimethoxysilane (0.1 mol, 14.3 g) were placed in a reaction vessel and stirred at 25°C for 30 minutes. A mixed solvent of distilled water and 1 N HNO3 (70.3 g) was slowly added to this mixture. After the addition was complete, the reaction vessel was sealed, nitrogen gas was purged at a rate of 25 cc / min, and the reaction mixture was stirred for 30 minutes. The temperature inside the reaction vessel was increased to 30°C over approximately 10 minutes and stirred for an additional 2 hours to thoroughly mix the reaction mixture. Thereafter, the temperature inside the reaction vessel was increased to 85°C over approximately 30 minutes and stirred for an additional 2 hours to obtain a copolymer.

[0318] The reaction product including the copolymer was cooled to 60°C over about 30 minutes, and 3-methacryloxypropyltrimethoxysilane (0.5 mol, 124.7 g) was added over about 2 hours. Upon completion of the addition, the temperature was raised to 85°C over about 30 minutes and stirred for an additional 2 hours. Propylene glycol monomethyl ether acetate (101.9 g) was added again to the reactor, and the reactor was slowly cooled to room temperature while stirring again to obtain an organic-inorganic hybrid siloxane copolymer (siloxane binder) including the repeating unit of Chemical Formula 1. The siloxane binder had a weight average molecular weight of 1,200 g / mol. The prepared siloxane binder solution was placed in a polypropylene container, sealed around the container, purged with nitrogen, and stored in a refrigerator.

[0319]

[0320] Synthesis Example 2: Synthesis of an organic-inorganic hybrid siloxane copolymer (siloxane binder) for a barrier layer.

[0321] 1 mol of ethanol, 0.8 mol of tetraethoxysilane, 0.1 mol of vinyltrimethoxysilane, and 0.1 mol of methyltrimethoxysilane were added to a reaction vessel and stirred at 25°C for 60 minutes. Then, 2.5 mol of ultrapure water and 30.5 mol of 1N HNO were slowly added to the mixture over 10 minutes. Upon completion of the addition, the temperature inside the reaction vessel was increased to 30°C over approximately 10 minutes and stirred for an additional 2 hours to hydrate the reactants. Thereafter, the temperature inside the reaction vessel was increased to 80°C over approximately 30 minutes and stirred for an additional 3 hours.

[0322] The reaction mixture was cooled to 30°C over approximately 20 minutes, diluted with 1 mol of ethanol to complete the reaction, and a siloxane binder containing the repeating unit of Chemical Formula 1 was prepared. The siloxane binder had a weight average molecular weight of 12,000 g / mol. The siloxane binder thus obtained was placed in a polypropylene container, sealed, and stored in a refrigerator.

[0323]

[0324] Examples and Comparative Examples

[0325] Preparation of coating composition

[0326] The components used in the coating compositions of the above examples and comparative examples are as follows.

[0327] (A) Siloxane-based binder: The siloxane-based binder manufactured in Synthesis Example 1 was used.

[0328] (B) Fluorine compound: 2,2,3,3,4,4,4-heptafluorobutyl methacrylate (2,2,3,3,4,4,4-heptafluorobutylmethacrylate, manufactured by Sigma) was used as a fluorine (meth)acrylate compound.

[0329] (C) Curing agent: Irgacure 184 (manufactured by JM Tech) was used as a photopolymerization initiator.

[0330] (D) Inorganic particles: (D1) MEK-AC-2140Z (colloidal silica, manufactured by Poonglim Pharmaceutical Co., Ltd.) with an average particle size of 12 nm was used. (D2) MEK-AC-4130Y (colloidal silica, manufactured by Poonglim Pharmaceutical Co., Ltd.) with an average particle size of 45 nm was used. (D3) MEK-AC-5140Z (colloidal silica, manufactured by Poonglim Pharmaceutical Co., Ltd.) with an average particle size of 80 nm was used.

[0331] (E) Additive: BYK307 (manufactured by BYK) was used as a leveling agent.

[0332] (F) Solvent: Methyl ethyl ketone (manufactured by Daejung Chemical Co., Ltd.) was used.

[0333] [Table 1]

[0334]

[0335]

[0336] Preparation of a composition for a barrier layer

[0337] The components used in the barrier layer compositions of the above examples and comparative examples are as follows.

[0338] (A) Solvent: Ultrapure water (DI water) was used.

[0339] (B) Siloxane-based binder: The siloxane-based binder manufactured in Synthesis Example 2 was used.

[0340] (C) (Meth)acrylate compound: Trimethylolpropane triacrylate (manufactured by Sigma) was used.

[0341] (D) Cellulose nanofibrils: (ANPOLY (Advanced Natural Polymer) Co., Ltd., product name: CNC Powder) was used.

[0342] (E) Curing agent: Irgacure 184 (manufactured by JM Tech) was used as a photopolymerization initiator.

[0343] (F) Infrared absorbing particles: Spherical titanium dioxide with an average particle diameter (d50) of 50 nm was used.

[0344]

[0345] Examples 1-3: Manufacturing of laminated films

[0346] (1-1) Preparation of barrier layer: A barrier layer composition comprising 100 parts by weight of the solvent (A), 10 parts by weight of a siloxane-based binder (Synthesis Example 2) (B), 5 parts by weight of a (meth)acrylate-based compound (C), 15 parts by weight of a cellulose nanofibril (D), 2 parts by weight of a curing agent (E), and 3 parts by weight of an infrared absorbing particle (F) was applied and cured on one surface of a primer-treated substrate layer (PET, thickness: 30 μm) by a known method to prepare a barrier layer (thickness: 50 μm).

[0347] (1-2) Formation of coating layer: The coating composition containing the ingredients and contents of Table 1 was stirred for 30 minutes, and applied to the other surface of the substrate layer using a Meyer bar to a thickness of 1 to 50 ㎛. Then, it was heated at 80°C for 1 minute, 500 mJ / cm 2 The coating composition was cured by exposing it to a light source to produce a coating layer having a surface roughness (Ra, arithmetic mean roughness) of 0.05 to 0.15 ㎛ and a thickness of 5 (±0.5) ㎛.

[0348] (1-3) Formation of adhesive layer and manufacture of laminated film: A composition for an adhesive layer comprising 100 parts by weight of a solvent (ultra-pure water), 3 parts by weight of a siloxane-based binder (weight average molecular weight (Mw): 27,000 g / mol) represented by the following chemical formula 2, and 0.3 parts by weight of a surface-treated filler (spherical silica having an average particle size of 12 nm surface-treated with a silane-based compound (Nissan Chemical, ST-C)) was applied to one surface of the barrier layer, and cured by a known method to form an adhesive layer having a thickness of 0.1 to 0.5 μm, thereby manufacturing a laminated film for a double-sided light-receiving solar module in which a coating layer, a substrate layer, a barrier layer, and an adhesive layer are sequentially laminated.

[0349] [Chemical Formula 2]

[0350] .

[0351] (In the above chemical formula 2, the R 8 , R 9 , R 10 and R 11 Each independently represents a hydrogen atom, a hydroxyl group, a mercapto group, a sulfonic acid group, and C1-C 20 Alkyl group, C1-C 10 Alkoxy group, C1-C 20 Alkyl amino group, vinyl group, C1-C 20 Alkyl vinyl group, C1-C 20 Alkyl (meth)acrylate group, C3-C 20 Alkyl (meth)acryloxy group or C6-C 20 is selected from among aryl groups, wherein c and d are each 1 to 100, and c and d are included in a weight ratio of 1:0.1 to 1:10.

[0352]

[0353] Experimental example (1)

[0354] (1) Light transmittance (%): The relative total light transmittance (Total Transmittance) of the laminated films of the above examples and comparative examples was measured, and the results are shown in Table 2 below.

[0355] (2) Hardness: For the laminated films of the above examples and comparative examples, the pencil hardness was measured for a load of 500 g using a pencil hardness tester according to the PET standard method (pencil hardness measurement method), and the results are shown in Table 2 below.

[0356] (3) Measurement of contamination resistance (water contact angle): The water contact angle was measured for the laminated films of the above examples and comparative examples using a contact angle measuring device, and the results are shown in Table 2 below.

[0357] (4) Water Vapor Transmission Ratio (WVTR, g / m) 2·24hr): The moisture permeability of the laminated films of the examples and comparative examples was measured using a moisture permeability measuring device (OX-TRAN 2 / 21MD) from MOCON. The specimens of the examples and comparative examples were cut into a size of 100 mm x 100 mm and measured by inserting them into a jig with a hole in the center. The measurement was performed for 24 hours under the conditions of a temperature of 36°C and a relative humidity of 100% RH. The WVTR was 3.0 g / m 2 ·If it is less than 24 hours, it is good (indicated by ○ in Table 2), and WVRT is 3.0 g / m 2 ·If it exceeds 24 hours, it is evaluated as defective (marked with X in Table 2).

[0358] [Table 2]

[0359]

[0360] In addition, as a result of observing the surface of the coating layer of Example 1 using a scanning electron microscope (SEM), it was found that the composite film of Example 1 had a rough pattern formed on the surface of the coating layer.

[0361] Referring to the results in Table 2 above, it was found that Examples 1 to 5 of the present invention had superior light transmittance, contamination resistance, and water repellency compared to Comparative Examples 1 to 3. In addition, compared to Comparative Example 3 using glass, when the coating layer of Examples 1 to 5 was applied, the weight of the solar module was reduced by more than 65%, resulting in excellent light weight and improved light transmittance, confirming that it can be applied as a replacement for the front glass of the solar module.

[0362] Figure 3 below shows the results of the water contact angle measurement of Example 4. Referring to Figure 3 above, it can be seen that Example 4 has excellent water repellency and contamination resistance on the surface.

[0363]

[0364] Experimental example (2)

[0365] (1) Manufacturing of a double-sided light-receiving solar module: A double-sided light-receiving solar module was manufactured by laminating adhesive layers of the laminated films of Example 1 and Comparative Example 1, respectively, on both sides of a solar cell element.

[0366] (2) For the double-sided photovoltaic modules of Example 1 and Comparative Example 1, the solar power generation efficiency was evaluated when a laminated film was formed on one side and both sides. Specifically, the solar power generation efficiency was evaluated according to the IEC 61215 standard, and the evaluation environment was 25℃ and 1,000W / m 2 The module efficiency (%) of Example 1 and Comparative Example 1 was evaluated in an atmosphere, and the results are shown in Table 3 below. In Table 3 below, the control group is the result measured for a solar cell device without a laminated film attached.

[0367] [Table 3]

[0368]

[0369] Referring to the results in Table 3 above, it was found that Example 1 of the present invention had superior light transmittance and solar power generation efficiency compared to Comparative Example 1 in which no uneven pattern was formed on the surface of the coating layer.

[0370]

[0371] The present invention has been described with reference to exemplary embodiments. Those skilled in the art will appreciate that the present invention can be implemented in modified forms without departing from its essential characteristics. Therefore, the disclosed embodiments should be considered illustrative rather than limiting. The scope of the present invention is set forth in the claims, not the foregoing description, and all differences within the scope equivalent thereto should be construed as being encompassed by the present invention.

[0372]

[0373] (Explanation of symbols)

[0374] 100, 101: Laminated film 110, 111: Barrier layer

[0375] 120, 121: Base layer 130, 131: Coating layer

[0376] 200: Solar cell element 1000: Solar module

[0377]

[0378] [Government Project Information]

[0379] [Project ID]1415174733

[0380] [Assignment Number] 20213030010290

[0381] Ministry of Trade, Industry and Energy

[0382] [Name of Project Management (Specialist) Institution] Korea Institute of Energy Technology Evaluation and Planning

[0383] [Research Project Name] Development of New and Renewable Energy Core Technologies

[0384] [Research Project Name]

[0385] Development of core materials for building-type solar power systems with guaranteed long-term reliability (over 25 years) and safety.

[0386] [Contribution rate] 1 / 1

[0387] [Name of the project performing organization] Sangbo Co., Ltd.

[0388] Research Period: January 1, 2023 - December 31, 2023

Claims

1. A laminated film for a double-sided light-receiving solar module in which a coating layer, a substrate layer, and a barrier layer are formed sequentially. The coating layer is a laminated film formed from a coating composition comprising a siloxane-based binder having a repeating structure of the following chemical formula 1, a fluorine-based (meth)acrylate compound, a curing agent, and inorganic particles, and having a surface with unevenness: [Chemical Formula 1] (In the above chemical formula 1, the R 1 , R 2 and R 3 are each independently a hydrogen atom, C1-C 20 Alkyl group, C1-C 20 Alkyl amino group, vinyl group, C1-C 20 Alkyl vinyl group, C1-C 20 Alkyl (meth)acrylate group, C3-C 20 Alkyl (meth)acryloxy group, C6-C 20 An aryl group, a sulfonic acid group, and a structure represented by the following chemical formula 1-1 are selected, wherein R 1 , R 2 and R 3 At least one of them has a structure represented by the following chemical formula 1-1, The above R 4 is C1-C 20 Alkyl group, C1-C 10 Alkoxy group, C2-C 20 Alkenyl group, C1-C 20 Alkyl amino group, C1-C 20 Alkyl vinyl group, C3-C 20 Alkyl (meth)acrylate group, C3-C 20 Alkyl (meth)acryloxy group, thiol group, C3-C 20 Alkyl thiol group, glycidyloxy group, C1-C 20 Alkyl glycidyloxy group, epoxy group, C1-C 20 Alkyl epoxy group, C4-C 20 Cycloalkyl epoxy group, C6-C 20 Aryl epoxy group and C3-C 20 Selected from heteroaryl epoxy groups, The above a and b are each 0.1 to 0.9, and the above a + b = 1) [Chemical Formula 1-1] (In the above chemical formula 1-1, the R 5 and R 6 are each independently C1-C 20 Alkyl group, C1-C 20 Alkyl amino group, hydroxyl group and C1-C 20 It is selected from among alkoxy groups, The above R 7 Silver vinyl group, C1-C 20 Alkyl vinyl group, C3-C 20 Alkyl (meth)acrylate group and C3-C 20 Alkyl (meth)acryloxy group is selected, and * is a connecting moiety).

2. A laminated film according to claim 1, wherein the coating composition comprises 100 parts by weight of the siloxane-based binder, 1 to 30 parts by weight of a fluorinated (meth)acrylate compound, 0.1 to 15 parts by weight of a curing agent, and 2 to 50 parts by weight of inorganic particles.

3. In the second paragraph, the coating composition is a laminated film containing the fluorine-based (meth)acrylate compound and inorganic particles in a weight ratio of 1:2 to 1:

7.

4. A laminated film in the first paragraph, wherein the barrier layer is formed from a composition for a barrier layer comprising a siloxane-based binder having a repeating structure of the chemical formula 1, a curing agent, cellulose nanofibrils, infrared absorbing particles, and a solvent.

5. In the first paragraph, an adhesive layer formed on the lower surface of the barrier layer is further included, The adhesive layer is a laminated film formed from a composition for an adhesive layer including a siloxane-based binder, a surface treatment filler, and a solvent represented by the following chemical formula 2: [Chemical Formula 2] (In the above chemical formula 2, the R 8 , R 9 , R 10 and R 11 Each independently represents a hydrogen atom, a hydroxyl group, a mercapto group, a sulfonic acid group, and C1-C 20 Alkyl group, C1-C 10 Alkoxy group, C1-C 20 Alkyl amino group, vinyl group, C1-C 20 Alkyl vinyl group, C1-C 20 Alkyl (meth)acrylate group, C3-C 20 Alkyl (meth)acryloxy group or C6-C 20 It is selected from aryl groups, The above c and d are each 1 to 100, and the above c and d are included in a weight ratio of 1:0.1 to 1:

10.

6. In the first paragraph, the laminated film is a laminated film having an average surface roughness (Ra) of 0.05 to 0.25 ㎛.

7. A method for manufacturing a laminated film for a double-sided light-receiving solar module, comprising the step of providing a laminated film in which a coating layer, a substrate layer, and a barrier layer are sequentially formed; The above coating layer is formed from a coating composition including a siloxane-based binder having a repeating structure of the following chemical formula 1, a fluorine-based (meth)acrylate compound, a curing agent, and inorganic particles, and a method for manufacturing a laminated film: [Chemical Formula 1] (In the above chemical formula 1, the R 1 , R 2 and R 3 are each independently a hydrogen atom, C1-C 20 Alkyl group, C1-C 20 Alkyl amino group, vinyl group, C1-C 20 Alkyl vinyl group, C1-C 20 Alkyl (meth)acrylate group, C3-C 20 Alkyl (meth)acryloxy group, C6-C 20 An aryl group, a sulfonic acid group, and a structure represented by the following chemical formula 1-1 are selected, wherein R 1 , R 2 and R 3 At least one of them has a structure represented by the following chemical formula 1-1, The above R 4 is C1-C 20 Alkyl group, C1-C 10 Alkoxy group, C2-C 20 Alkenyl group, C1-C 20 Alkyl amino group, C1-C 20 Alkyl vinyl group, C3-C 20 Alkyl (meth)acrylate group, C3-C 20 Alkyl (meth)acryloxy group, thiol group, C3-C 20 Alkyl thiol group, glycidyloxy group, C1-C 20 Alkyl glycidyloxy group, epoxy group, C1-C 20 Alkyl epoxy group, C4-C 20 Cycloalkyl epoxy group, C6-C 20 Aryl epoxy group and C3-C 20 Selected from heteroaryl epoxy groups, The above a and b are each 0.1 to 0.9, and the above a + b = 1) [Chemical Formula 1-1] (In the above chemical formula 1-1, the R 5 and R 6 are each independently C1-C 20 Alkyl group, C1-C 20 Alkyl amino group, hydroxyl group and C1-C 20 It is selected from among alkoxy groups, The above R 7 Silver vinyl group, C1-C 20 Alkyl vinyl group, C3-C 20 Alkyl (meth)acrylate group and C3-C 20 Alkyl (meth)acryloxy group is selected, and * is a connecting moiety).

8. Solar cell elements; and It is formed on both sides of the solar cell element, and includes a laminated film according to any one of claims 1 to 6; A solar module in which a barrier layer of the laminated film is laminated on each of the two sides of the solar cell element.

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