Low refractive index thermosetting composition, optical component formed therefrom, and display device.

Abstract

The present invention relates to a thermosetting composition, and an optical element and a display device formed therefrom. The composition contains a thermosetting resin; gas-containing particles; and a monomer or oligomer having two or more thermosetting functional groups. By containing the thermosetting composition, the composition has optical effects such as a low refractive index of 1.40 or less for light with a wavelength of 450 nm, high light transmittance, and low haze.

Description

Technical Field

[0001] This application is a claim for priority based on Korean Patent Application No. 10-2020-0125953, filed on September 28, 2020, and all the contents disclosed in the specification of the application are incorporated herein by reference.

[0002] This application is a claim for priority based on Korean Patent Application No. 10-2021-0050938, filed on April 20, 2021, and all the contents disclosed in the specification of the application are incorporated herein by reference. The present invention relates to a thermosetting composition having a low refractive index, an optical member formed therefrom, and a display device.

Background Art

[0003] Needs for technologies to improve light efficiency in organic light-emitting diodes (OLEDs), QD-OLEDs (Quantum dot-Organic Light-Emitting Diodes), QNEDs (quantum nano-emitting diodes), Micro-LEDs, and image sensors have been continuously increasing. The technology for improving the light efficiency is an essential technology for reducing the reflectance of displays, improving the lifespan of OLEDs, and increasing the efficiency of batteries, and recently, research and development have been actively conducted.

[0004] In order to improve the light efficiency, a technology for reducing the refractive index of light at the boundary of a medium is required. The range of refractive index that can be adjusted using an organic compound as a medium is known to have a lower limit of about 1.40 in the early and middle stages theoretically, and it is insufficient to improve the light efficiency with conventional organic compounds. Therefore, in order to realize an optical member having a refractive index of 1.40 or less at the boundary of a medium, a hybrid technology including hollow silica or the like in addition to an organic compound is required.

[0005] However, when hollow silica is mixed in, although the refractive index is lower, there are many technical limitations due to issues such as decreased transmittance and haze due to compatibility problems with organic compounds, and reduced adhesion between the upper and lower films.

[0006] Due to these problems with conventional technologies, there is a continuous need for the development of technologies that enable the formation of optical films and the like that exhibit low refractive index characteristics while suppressing the decrease in transmittance and increase in haze, as well as excellent adhesive strength and heat resistance. [Overview of the project] [Problems that the invention aims to solve]

[0007] The object of the present invention is to provide a thermosetting composition that has a low refractive index, excellent light transmittance, suppressed haze increase, and excellent adhesive strength and heat resistance. Another object of the present invention is to provide an optical component that includes a cured film cured by including the thermosetting composition. Another object of the present invention is to provide a display device including the optical element. [Means for solving the problem]

[0008] To achieve the above objective, a thermosetting composition according to one embodiment of the present invention comprises a thermosetting resin; gas-containing particles; and a monomer or oligomer having two or more thermosetting functional groups. To achieve the above objective, an optical component according to another embodiment of the present invention comprises a substrate and a cured film cured by including the thermosetting composition. To achieve the above objective, a display device according to another embodiment of the present invention includes the optical member. [Effects of the Invention]

[0009] The thermosetting composition of the present invention, upon curing to form a cured film, has the following advantages: it has a low refractive index of 1.40 or less for light at a wavelength of 450 nm, excellent light transmittance, and low haze optical properties; as well as excellent adhesion to the surface of the cured film and excellent heat resistance of the cured film itself. A display device according to one embodiment of the present invention has the effect of excellent improvement in light efficiency by including an optical component using the thermosetting composition. [Modes for carrying out the invention]

[0010] The terms or words used herein and in the claims should not be interpreted in a manner limited to their ordinary and lexicographical meanings, but rather in a manner consistent with the technical idea of ​​the present invention, in accordance with the principle that inventors may appropriately define the concepts of terms in order to best describe their invention.

[0011] Therefore, it should be understood that the configurations shown in the embodiments described herein represent only one of the most preferred embodiments of the present invention and do not represent the entire technical concept of the invention, and that there may be various equivalents and modifications that can be substituted for them at the time of filing.

[0012] A thermosetting composition according to one embodiment of the present invention comprises a thermosetting resin, gas-containing particles, and a monomer or oligomer having a thermosetting functional group, wherein the monomer or oligomer has two or more thermosetting functional groups.

[0013] The monomer or oligomer having two or more thermosetting functional groups provides the effect of further improving the thermosetting properties of the composition by improving the degree of thermosetting between the resin and the gas-containing particles.

[0014] The thermosetting resin may, specifically, be a resin containing at least one of epoxy groups, oxetane groups, or hydroxyl (OH) groups for thermosetting purposes, and may be, for example, a thermocrystalline resin containing epoxy groups.

[0015] Specifically, the thermosetting resin may have a weight-average molecular weight of 1,000 to 200,000. If the weight-average molecular weight of the thermosetting resin is less than 1,000, problems may occur with the adhesion strength of the low-refractive index thermosetting layer, inkjet processability, and slit coating properties. Conversely, if it exceeds 200,000, the viscosity may be high, causing problems with inkjet ejection properties, etc.

[0016] The aforementioned gas-containing particle refers to a solid particle that has an internal space (void) separated from the outside, and this internal space is filled with gas. The particle size of the gas-containing particle refers to the length of the diameter relative to the outer surface of the gas-containing particle.

[0017] The gas-containing particles play a role in significantly lowering the refractive index of the composition due to the internal space (voids) they contain. However, the gas-containing particles have poor compatibility with organic compounds, making it important to maintain an appropriate content range. Therefore, in one embodiment of the present invention, by containing the gas-containing particles at 30 to 80% by weight relative to the total weight, a thermosetting composition having a refractive index of 1.40 or less for light at a wavelength of 450 nm can be realized. If the gas-containing particles are contained at less than 30% by weight relative to the total weight of the composition, it may be difficult to achieve a refractive index of 1.40 or less. If they are contained at more than 80% by weight, poor compatibility with other organic compounds in the composition may lead to decreased transmittance and haze, and a decrease in adhesive strength after curing.

[0018] More specifically, when the gas-containing particles are present in an amount of 50 to 80% by weight relative to the total weight of the thermosetting composition, a thermosetting composition having a refractive index of 1.25 or less for light with a wavelength of 450 nm can be realized.

[0019] The gas-containing particles may be hollow organic or inorganic particles, for example, pologen or hollow silica, and hollow silica can be used as one embodiment of the present invention.

[0020] The gas-containing particles can prevent the phenomenon of aggregation between particles through a surface treatment process, thereby improving the dispersibility of the particles. When the gas-containing particles aggregate with each other, problems may occur such as poor compatibility with other organic compounds in the composition, resulting in a decrease in transmittance and haze, and a decrease in the adhesive strength after curing.

[0021] Specifically, the gas-containing particles can be surface-treated with one or more functional groups selected from the group consisting of an alkyl group, an acrylic group, a methacrylic group, an epoxy group, and a vinyl group.

[0022] In the process of surface-treating the gas-containing particles, if the thickness of the surface treatment is less than 3 nm, problems may occur such as poor surface treatment effect, aggregation between the gas-containing particles, and an increase in haze. Conversely, if the thickness of the surface treatment is greater than 50 nm, problems may occur such as a deterioration in the refractive index of the composition. Therefore, the gas-containing particles are preferably surface-treated with a thickness of 3 to 50 nm, and may also be surface-treated with a thickness of 3 to 30 nm to achieve a lower refractive index.

[0023] The D50 particle size of the gas-containing particles is preferably 30 to 150 nm. Specifically, it is preferably 30 to 150 nm based on the D50 particle size measured by DLS Litesizer 500 (manufactured by Anton Paar). If the D50 particle size is less than 30 nm, problems may occur such as a decrease in the refractive index. If the D50 particle size exceeds 150 nm, problems may occur such as poor dispersion margin, a decrease in transmittance and haze, and a decrease in the adhesive strength between the upper and lower films due to insufficient crosslinking degree with the resin.

[0024] When gas-containing particles are included in the composition, the thermosetting resin alone is insufficient to ensure the degree of curing of the composition. Therefore, monomers and / or oligomers containing thermosetting functional groups can be additionally applied to improve the degree of curing, and furthermore, the adhesion to the upper and lower films of the low refractive index layer can be improved. The monomer or oligomer having the thermosetting functional group can specifically ensure thermosetting by including an alicyclic epoxy structure with excellent reactivity. The monomer or oligomer having the thermosetting functional group can, as a specific example, have any one of the chemical structures represented by the following Chemical Formulas 1 to 24. [Chemical Formula 1] TIFF0007832181000001.tif31170[Chemical Formula 2] TIFF0007832181000002.tif31170[Chemical Formula 3] TIFF0007832181000003.tif75170[Chemical Formula 4] TIFF0007832181000004.tif34170[Chemical Formula 5] TIFF0007832181000005.tif31170[Chemical Formula 6] TIFF0007832181000006.tif22170[Chemical Formula 7] TIFF0007832181000007.tif23170[Chemical Formula 8] TIFF0007832181000008.tif17170[Chemical Formula 9] TIFF0007832181000009.tif35170[Chemical Formula 10] TIFF0007832181000010.tif20170[Chemical Formula 11] TIFF0007832181000011.tif25170[Chemical Formula 12] TIFF0007832181000012.tif40170[Chemical Formula 13] TIFF0007832181000013.tif57170[Chemical Formula 14] TIFF0007832181000014.tif39170[Chemical Formula 15] TIFF0007832181000015.tif54170[Chemical formula 16] TIFF0007832181000016.tif35170[Chemical formula 17] TIFF0007832181000017.tif19170[Chemical formula 18] TIFF0007832181000018.tif36170[Chemical formula 19] TIFF0007832181000019.tif63170[Chemical formula 20] TIFF0007832181000020.tif17170[Chemical formula 21] TIFF0007832181000021.tif17170[Chemical formula 22] TIFF0007832181000022.tif24170[Chemical formula 23] TIFF0007832181000023.tif18170[Chemical formula 24] TIFF0007832181000024.tif17170

[0025] In chemical formulas 4 and 6, R independently represents a hydrocarbon group having 1 to 10 carbon atoms, R in chemical formula 6 is one of an alkyl, alkenyl, or alkoxy group, and in chemical formulas 2 to 4, 11 to 13, and 20 to 21, l, m, n, and o are each independently integers from 1 to 30.

[0026] In this case, instead of 4,4'-[1-[4-[1-[4-hydroxyphenyl]-1-methylethyl]phenyl]ethylene]bisphenol, which was used as a precursor of chemical formula 19, a compound having a chemical structure selected from the following chemical formulas 25 to 32 can be used. [Chemical formula 25] TIFF0007832181000025.tif39170[Chemical formula 26] TIFF0007832181000026.tif25170[Chemical formula 27] TIFF0007832181000027.tif52170[Chemical formula 28] TIFF0007832181000028.tif56170[Chemical formula 29] TIFF0007832181000029.tif28170[Chemical formula 30] TIFF0007832181000030.tif32170[Chemical formula 31] TIFF0007832181000031.tif27170[Chemical formula 32] TIFF0007832181000032.tif46170

[0027] In order to achieve the formation of a cured film with excellent adhesion to the upper and lower parts of the thermosetting composition and to realize excellent optical properties, the specific composition ratio is preferably such that the thermosetting resin is 1 to 69% by weight, the gas-containing particles are 30 to 80% by weight, and the monomer or oligomer having a thermosetting functional group is 1 to 60% by weight.

[0028] The formation of a cured film with excellent adhesion to the upper and lower surfaces and excellent optical properties of the aforementioned thermosetting composition is related to the total weight ratio of the thermosetting resin to the monomer or oligomer having a thermosetting functional group. Specifically, the total weight of the thermosetting resin and the monomer or oligomer having a thermosetting functional group may be 20 to 70% by weight of the total composition.

[0029] The thermosetting composition may further contain one or more additives selected from the group consisting of silane coupling agents, adhesives with alkoxy groups as crosslinking sites, and surfactants in order to further improve the adhesion strength to the upper and lower parts of the low refractive index layer.

[0030] Specifically, the silane coupling agent may be included in an amount of 0.1 to 30 parts by weight per 100 parts by weight of the thermosetting resin. If the amount is less than 0.1 parts by weight, a problem may occur in which the adhesive strength margin decreases, and if it exceeds 30 parts by weight, a problem may occur in terms of storage stability.

[0031] The silane coupling agent is, for example, (3-glycidoxypropyl)trimethoxysilane, (3-glycidoxypropyl)triethoxysilane, (3-glycidoxypropyl)methyldimethoxysilane, (3-glycidoxypropyl)methyldiethoxysilane, (3-glycidoxypropyl)dimethylethoxysilane, 3,4-epoxybutyltrimethoxysilane, 3,4-epoxybutyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, aminopropyl It may contain, but is not limited to, at least one selected from the group consisting of trimethoxysilane, aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-2(aminoethyl)3-aminopropyltrimethoxysilane, N-2(aminoethyl)3-aminopropyltriethoxysilane, N-2(aminoethyl)3-aminopropylmethyldimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, and (3-isocyanatetopropyl)triethoxysilane.

[0032] Furthermore, the adhesive using the alkoxy group as a crosslinking site may be included in an amount of 0.1 to 30 parts by weight per 100 parts by weight of the thermosetting resin. If the amount is less than 0.1 parts by weight, a problem may arise in which the adhesive strength margin decreases, and if it exceeds 30 parts by weight, a problem may arise in terms of storage stability.

[0033] Furthermore, the surfactant may be included in an amount of 0.0001 to 5 parts by weight per 100 parts by weight of the thermosetting resin. If the amount is less than 0.0001 parts by weight, problems with coating properties may occur, and if it exceeds 5 parts by weight, problems with coating bubble formation may occur.

[0034] The thermosetting composition may further contain one or more dispersants selected from the group consisting of acrylic dispersants, epoxy dispersants, and silicone dispersants in order to improve dispersibility. Furthermore, the thermosetting composition may further contain one or more crosslinking accelerators selected from the group consisting of thermal acid generators and thermal base generators in order to promote curing.

[0035] The thermosetting composition may contain a solvent, but may also be a solvent-free type that does not contain a solvent. If a solvent is included, it serves to improve the compatibility or coating properties between the thermosetting resin and gas-containing particles. In this case, in order to facilitate the coating of the thermosetting composition, the solvent may be diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, propylene glycol methyl ether propionate, propylene glycol ethyl ether propionate, propylene glycol propyl ether propionate, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol propyl ether, propylene glycol butyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, or butylene It may contain one or more solvents selected from the group consisting of glycol monomethyl ether, butylene glycol monoethyl ether, dibutylene glycol dimethyl ether, and dibutylene glycol diethyl ether, diethylene glycol butyl methyl ether, diethylene glycol butyl ethyl ether, triethylene glycol dimethyl ether, triethylene glycol butyl methyl ether, diethylene glycol t-butyl ether, tetraethylene glycol dimethyl ether, diethylene glycol ethylhexyl ether, diethylene glycol methylhexyl ether, dipropylene glycol butyl methyl ether, dipropylene glycol ethylhexyl ether, and dipropylene glycol methylhexyl ether.

[0036] The viscosity of the thermosetting composition can be adjusted by controlling the content of the solvent, and the viscosity can be specifically 3 to 30 cP in order to achieve both processability and excellent optical properties. An optical component according to one embodiment of the present invention comprises a substrate and a cured film, the cured film being cured by containing a thermosetting composition according to one embodiment of the present invention. The optical component can achieve excellent optical properties, having a refractive index of 1.40 or less and a haze of 3% or less, based on light with a wavelength of 450 nm. The optical component may be, for example, a light extraction layer or a refractive index adjustment layer, but is not limited to the examples given above.

[0037] A display device according to one embodiment of the present invention includes the optical element and may, for example, be an OLED, QLED, or microLED display device with excellent brightness, but is not limited to the above examples.

[0038] The embodiments of the present invention will be described in detail below so that they can be easily implemented by a person with ordinary skill in the art to which the present invention pertains. However, the present invention can be realized in a variety of different forms and is not limited to the manufacturing examples and embodiments described herein.

[0039] [Manufacturing Example 1: Synthesis of Thermosetting Resins] As an example of a thermosetting resin in a thermosetting composition according to one aspect of the present invention, a resin containing epoxy groups, oxetane groups, hydroxyl groups, etc., was used. Examples of the synthesis of thermosetting resins included in the thermosetting composition are shown in Synthesis Examples 1 to 10 below, and examples of the synthesis of thermosetting resins to compare the effect differences with the above synthesis examples are shown in Reference Synthesis Examples 1 to 3 below.

[0040] [Synthesis Example 1] In a flask equipped with a condenser and a stirrer, 10 parts by weight of 2,2'-azobis(2,4-dimethylvaleronitrile), 500 parts by weight of tetrahydroxyfuran, and 100 parts by weight of glycidyl methacrylate were added, and after purging with nitrogen, the mixture was gently stirred. The reaction solution was heated to 60°C and maintained at this temperature for 24 hours to produce a polymer solution containing an acrylic copolymer.

[0041] The polymer solution containing the acrylic copolymer was precipitated at a rate of 100 parts by weight per 1,000 parts by weight of n-hexane. Next, the waste liquid was removed by a filtering process using a mesh (meth), and then the mixture was vacuum-dried at 30°C or below to produce an epoxy group-containing thermosetting resin with a weight-average molecular weight of 10,000.

[0042] At this time, the weight-average molecular weight was measured using the standard analytical method of gel permeation chromatography (GPC) with the Waters e2695 Alliance Separation Module. The aforementioned weight-average molecular weight is the average molecular weight on a polystyrene basis, measured using GPC.

[0043] [Synthesis Example 2] An epoxy group-containing thermosetting resin was produced in the same manner as in Synthesis Example 1, except that 80 parts by weight of metaglycidyl methacrylate and 20 parts by weight of styrene were used instead of 100 parts by weight of glycidyl methacrylate. The weight-average molecular weight of the epoxy group-containing thermosetting resin synthesized by the above synthesis example 2 is 8,000.

[0044] In this case, the weight-average molecular weight was the polystyrene-equivalent weight-average molecular weight measured using GPC, and the weight-average molecular weight was measured using the standard analytical method of gel permeation chromatography (GPC) with the Waters e2695 Alliance Separation Module.

[0045] [Synthesis Example 3] An oxetane group-containing thermosetting resin was produced in the same manner as in Synthesis Example 1, except that 60 parts by weight of 3-ethyl 3-oxetanylmethyl methacrylate and 40 parts by weight of ethoxyethoxyethyl acrylate were used instead of 100 parts by weight of glycidyl methacrylate. The weight-average molecular weight of the oxetane group-containing thermosetting resin synthesized by the above synthesis example 3 is 5,000.

[0046] In this case, the weight-average molecular weight was the polystyrene-equivalent weight-average molecular weight measured using GPC, and the weight-average molecular weight was measured using the standard analytical method of gel permeation chromatography (GPC) with the Waters e2695 Alliance Separation Module.

[0047] [Synthesis Example 4] In the same method as in Synthesis Example 1, an epoxy group-containing thermosetting resin was produced, except that 1.1 parts by weight of 2,2'-azobis(2,4-dimethylvaleronitrile) was used as the initiator instead of 10 parts by weight, and the reaction solution was heated to 60°C and maintained at this temperature for 20 hours. The weight-average molecular weight of the epoxy group-containing thermosetting resin synthesized by the above synthesis example 4 is 200,000.

[0048] In this case, the weight-average molecular weight was the polystyrene-equivalent weight-average molecular weight measured using GPC, and the weight-average molecular weight was measured using the standard analytical method of gel permeation chromatography (GPC) with the Waters e2695 Alliance Separation Module.

[0049] [Synthesis Example 5] In the same method as in Synthesis Example 1, an epoxy group-containing thermosetting resin was produced, except that 29 parts by weight of 2,2'-azobis(2,4-dimethylvaleronitrile) were used as the initiator instead of 10 parts by weight, and the reaction solution was heated to 60°C and maintained at this temperature for 6 hours. The weight-average molecular weight of the epoxy group-containing thermosetting resin synthesized by the above synthesis example 5 is 1,000.

[0050] In this case, the weight-average molecular weight was the polystyrene-equivalent weight-average molecular weight measured using GPC, and the weight-average molecular weight was measured using the standard analytical method of gel permeation chromatography (GPC) with the Waters e2695 Alliance Separation Module.

[0051] [Synthesis Example 6] In the above-mentioned Synthesis Example 1, 60 parts by weight of 2-hydroxyethyl acrylate and 40 parts by weight of perfluorooctyl ethyl acrylate were used instead of 100 parts by weight of glycidyl methacrylate, and 5 parts by weight of 2,2'-azobis(2,4-dimethylvaleronitrile) were used instead of 10 parts by weight of 2,2'-azobis(2,4-dimethylvaleronitrile) as an initiator, and the reaction solution was heated to 60°C and maintained at this temperature for 24 hours. Except for these differences, a hydroxyl group-containing thermosetting resin was produced in the same manner as in Synthesis Example 1. The weight-average molecular weight of the hydroxyl group-containing thermosetting resin synthesized by the above synthesis example 6 is 52,000.

[0052] In this case, the weight-average molecular weight was the polystyrene-equivalent weight-average molecular weight measured using GPC, and the weight-average molecular weight was measured using the standard analytical method of gel permeation chromatography (GPC) with the Waters e2695 Alliance Separation Module.

[0053] [Synthesis Example 7] In the above-mentioned Synthesis Example 1, an epoxy group-containing thermosetting resin was produced in the same manner as in Synthesis Example 1, except that 60 parts by weight of 3,4-epoxycyclohexylmethyl methacrylate and 40 parts by weight of lauryl methacrylate were used instead of 100 parts by weight of glycidyl methacrylate, 3 parts by weight of 2,2'-azobis(2,4-dimethylvaleronitrile) were used as the initiator instead of 10 parts by weight, and the reaction solution was heated to 60°C and maintained at this temperature for 24 hours. The weight-average molecular weight of the epoxy group-containing thermosetting resin synthesized by the above synthesis example 7 is 106,000.

[0054] In this case, the weight-average molecular weight was the polystyrene-equivalent weight-average molecular weight measured using GPC, and the weight-average molecular weight was measured using the standard analytical method of gel permeation chromatography (GPC) with the Waters e2695 Alliance Separation Module.

[0055] [Synthesis Example 8] 80 parts by weight of 3-glycidoxypropyltrimethoxysilane and 20 parts by weight of tetraethoxysilane were placed in a flask equipped with a condenser and a stirrer, and after purging with nitrogen, the mixture was gently stirred. 50 parts by weight of ultrapure water and 4 parts by weight of oxalic acid as a catalyst were then added to the reaction solution, and the mixture was gently stirred again. After 1 hour, the reaction solution was heated to 60°C and maintained at this temperature for 10 hours for polymerization, after which it was cooled to room temperature to terminate the reaction. By vacuum drying at 30°C or below to remove the water and alcohol components generated during the reaction, an epoxy and hydroxyl group-containing thermosetting resin with a weight-average molecular weight of 3,000 was produced.

[0056] In this case, the weight-average molecular weight was the polystyrene-equivalent weight-average molecular weight measured using GPC, and the weight-average molecular weight was measured using the standard analytical method of gel permeation chromatography (GPC) with the Waters e2695 Alliance Separation Module.

[0057] [Synthesis Example 9] An epoxy group and hydroxyl group-containing thermosetting resin was produced in the same manner as in Synthesis Example 1, except that in Synthesis Example 8, 40 parts by weight of 3-glycidoxypropyltrimethoxysilane and 60 parts by weight of tetraethoxysilane were used instead of 80 parts by weight of 3-glycidoxypropyltrimethoxysilane and 20 parts by weight of tetraethoxysilane. The weight-average molecular weight of the epoxy group and hydroxyl group-containing thermosetting resin synthesized by the above synthesis example 9 is 15,000.

[0058] In this case, the weight-average molecular weight was the polystyrene-equivalent weight-average molecular weight measured using GPC, and the weight-average molecular weight was measured using the standard analytical method of gel permeation chromatography (GPC) with the Waters e2695 Alliance Separation Module.

[0059] [Synthesis Example 10] An epoxy group and hydroxyl group-containing thermosetting resin was produced in the same manner as in Synthesis Example 1, except that in Synthesis Example 8, 20 parts by weight of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and 80 parts by weight of tetramethoxysilane were used instead of 80 parts by weight of 3-glycidoxypropyltrimethoxysilane and 20 parts by weight of tetraethoxysilane. The weight-average molecular weight of the epoxy and hydroxyl group-containing thermosetting resin synthesized by Synthesis Example 10 is 46,000.

[0060] In this case, the weight-average molecular weight was the polystyrene-equivalent weight-average molecular weight measured using GPC, and the weight-average molecular weight was measured using the standard analytical method of gel permeation chromatography (GPC) with the Waters e2695 Alliance Separation Module.

[0061] [Reference synthesis example 1] An epoxy group-containing thermosetting resin was produced in the same manner as in Synthesis Example 1, except that 30 parts by weight of 2,2'-azobis(2,4-dimethylvaleronitrile) were used as the initiator instead of 10 parts by weight in Synthesis Example 1, and the reaction solution was heated to 60°C and maintained at this temperature for 6 hours. The weight-average molecular weight of the epoxy group-containing thermosetting resin synthesized by the above-mentioned Reference Synthesis Example 1 is 900.

[0062] In this case, the weight-average molecular weight was the polystyrene-equivalent weight-average molecular weight measured using GPC, and the weight-average molecular weight was measured using the standard analytical method of gel permeation chromatography (GPC) with the Waters e2695 Alliance Separation Module.

[0063] [Reference synthesis example 2] In the same method as in Synthesis Example 1, an epoxy group-containing thermosetting resin was produced, except that 1 part by weight of 2,2'-azobis(2,4-dimethylvaleronitrile) was used as the initiator instead of 10 parts by weight, and the reaction solution was heated to 60°C and maintained at this temperature for 24 hours. The weight-average molecular weight of the epoxy group-containing thermosetting resin synthesized by the above-mentioned Reference Synthesis Example 2 is 201,000.

[0064] In this case, the weight-average molecular weight was the polystyrene-equivalent weight-average molecular weight measured using GPC, and the weight-average molecular weight was measured using the standard analytical method of gel permeation chromatography (GPC) with the Waters e2695 Alliance Separation Module.

[0065] [Reference synthesis example 3] An epoxy group and hydroxyl group-containing thermosetting resin was produced in the same manner as in Synthesis Example 7, except that, in Synthesis Example 8, 30 parts by weight of 3-glycidoxypropyltrimethoxysilane and 70 parts by weight of tetraethoxysilane were used instead of 80 parts by weight of 3-glycidoxypropyltrimethoxysilane and 20 parts by weight of tetraethoxysilane as the reactive silanes. The weight-average molecular weight of the epoxy and hydroxyl group-containing thermosetting resin synthesized by the above-mentioned Reference Synthesis Example 3 is 250,000.

[0066] In this case, the weight-average molecular weight was the polystyrene-equivalent weight-average molecular weight measured using GPC, and the weight-average molecular weight was measured using the standard analytical method of gel permeation chromatography (GPC) with the Waters e2695 Alliance Separation Module.

[0067] [Comparative Synthesis Example 1] A thermosetting group-free resin with a weight-average molecular weight of 9,000 was produced in the same manner as in Synthesis Example 1, except that 100 parts by weight of lauryl methacrylate were used instead of 100 parts by weight of glycidyl methacrylate.

[0068] In this case, the weight-average molecular weight was the polystyrene-equivalent weight-average molecular weight measured using GPC, and the weight-average molecular weight was measured using the standard analytical method of gel permeation chromatography (GPC) with the Waters e2695 Alliance Separation Module.

[0069] [Comparative Synthesis Example 2] A thermosetting group-free resin with a weight-average molecular weight of 135,000 was produced in the same manner as in Synthesis Example 1, except that 50 parts by weight of lauryl methacrylate and 50 parts by weight of styrene were used instead of 100 parts by weight of glycidyl methacrylate, and 1.5 parts by weight of 2,2'-azobis(2,4-dimethylvaleronitrile) was used as an initiator instead of 10 parts by weight.

[0070] In this case, the weight-average molecular weight was the polystyrene-equivalent weight-average molecular weight measured using GPC, and the weight-average molecular weight was measured using the standard analytical method of gel permeation chromatography (GPC) with the Waters e2695 Alliance Separation Module.

[0071] [Comparative Synthesis Example 3] A thermosetting group-free resin with a weight-average molecular weight of 25,000 was produced by the same method as in Synthesis Example 1, except that 50 parts by weight of lauryl methacrylate and 50 parts by weight of ethyl methacrylate were used instead of 100 parts by weight of glycidyl methacrylate, and 5 parts by weight of 2,2'-azobis(2,4-dimethylvaleronitrile) were used as the initiator instead of 10 parts by weight.

[0072] In this case, the weight-average molecular weight was the polystyrene-equivalent weight-average molecular weight measured using GPC, and the weight-average molecular weight was measured using the standard analytical method of gel permeation chromatography (GPC) with the Waters e2695 Alliance Separation Module.

[0073] [Manufacturing Example 2: Manufacturing of Low-Refractive Index Thermosetting Compositions and Optical Films] Using the resins synthesized in the above synthesis example, reference synthesis example, and comparative synthesis example, thermosetting compositions of Examples 1 to 64, Comparative Examples 1 to 6, and Reference Examples 1 to 15 were prepared with the compositions shown in Tables 1 to 3 below. In this case, hollow silica was used as the gas-containing particles, and epoxy monomers were used as the monomers having thermosetting functional groups.

[0074] At this time, a composition containing epoxy resin, epoxy monomer or oligomer and hollow silica was placed in the inkjet equipment and slit coater equipment, applied to the SiOx film, and pre-baked to form a single film with a thickness of 2.5 μm.

[0075] Subsequently, a cured film of the low-refractive-index thermosetting composition was produced by heat treatment in a convection oven at 180°C for 30 minutes. The thickness of the formed cured film was maintained at 2 μm.

[0076] [Table 1]

[0077] [Table 2]

[0078] [Table 3] The epoxy monomer structures in Tables 1-3 are as follows: [Chemical formula 1] TIFF0007832181000036.tif31170[Chemical formula 2] TIFF0007832181000037.tif31170 (The detailed structure of chemical formula 2 used in the embodiment of the present invention is a structure in which n is 2) [Chemical formula 5] TIFF0007832181000038.tif31170[Chemical formula 7] TIFF0007832181000039.tif23170[Chemical formula 9] TIFF0007832181000040.tif35170[Chemical formula 14] TIFF0007832181000041.tif39170[Chemical formula 17] TIFF0007832181000042.tif19170[Chemical formula 22] TIFF0007832181000043.tif24170[Chemical formula 23] TIFF0007832181000044.tif18170[Chemical formula 24] TIFF0007832181000045.tif17170

[0079] [Experimental Example: Measurement of Physical Properties of Optical Films] The optical films of the reference example and the example manufactured according to Manufacturing Example 2 were subjected to measurements of physical properties such as refractive index, haze, and viscosity using the following method, and the results are shown in Tables 5 to 7. [Experimental Example 1: Measurement of the refractive index of an optical film] The refractive index (average of 450 ± 20 nm) of the aforementioned optical film was measured using an ellipsometer and is shown in Tables 5 to 7 below using symbols according to the following criteria. ◎: When the refractive index measurement of the optical film is 1.25 or less. ○: When the refractive index measurement of the optical film is between 1.26 and 1.40 Δ: When the refractive index measurement of the optical film is between 1.41 and 1.45 X: When the refractive index measurement of the optical film exceeds 1.45

[0080] [Experimental Example 2: Measurement of Light Transmittance of Optical Film] The average transmittance at 450±20nm was measured for the optical film using a UV-VIS spectrophotometer (Cary4000, manufactured by Agilent), and the results are shown in Tables 5-7 below using symbols according to the following criteria. ○: When the average transmittance value is 90% or higher Δ: When the average transmittance value is greater than 80 but less than 90% X: If the average transmittance value is less than 80%

[0081] [Experimental Example 3: Measurement of Haze in Optical Films] The haze was measured using a COH 400 haze meter manufactured by Nippon Denshoku Industries Co., Ltd., and the results are shown in Tables 5-7 below using symbols according to the following criteria. ○: When the haze measurement is 3.0 or less Δ: When the haze measurement is greater than 3.0 and less than or equal to 4.0 X: When the haze measurement exceeds 4.0

[0082] [Experimental Example 4: Measurement of the viscosity (absolute viscosity) of a composition] The absolute viscosity of each photopolymerizable composition and olefin monomer in the above-mentioned reference examples and examples was measured at a temperature of 25°C using a viscometer (product name: Brook Field viscometer), and the results are shown in Tables 5 to 7 below using symbols according to the following criteria. ◎: When the absolute viscosity is 5 to 20 cP or less. ○: When the absolute viscosity is greater than 20 and less than or equal to 30 cP. Δ: When the absolute viscosity value is greater than 30 and less than or equal to 40 cP. X: When the absolute viscosity value falls outside the above range.

[0083] [Experimental Example 5: Evaluation of Inkjet Processability] The nozzle temperature of the inkjet equipment was changed to confirm that a surface was formed, and this was indicated in Tables 5-7 below using symbols according to the following criteria. A surface is formed at a nozzle temperature of 25-45°C = ○ A surface is formed when the nozzle temperature exceeds 45°C and reaches 50°C = Δ At nozzle temperatures of 25-50°C, no surface is formed (Uncoating) = X

[0084] [Experimental Example 6: Evaluation of Slit Coating Properties] The coating properties were confirmed using a slit coater, and the thickness of the coating was indicated in Tables 5-7 below using symbols according to the following criteria. Thickness of spraying within 5% = ○ Thickness of dispersion within 10% = Δ Thickness exceeding 10% = X

[0085] [Experimental Example 7: Evaluation of the bottom adhesion of optical film] A 1 mm thick cured film formed on the lower SiOx film. 2 100 cells were cross-cut at intervals of [specified interval], and the adhesion strength to the underlying SiOx film was compared using tape. The lower adhesion of the optical film was classified from 0 to 5B according to the classification criteria of the adhesion test results in Table 4 below, as shown in Tables 5 to 7 below.

[0086] [Table 4]

[0087] [Experimental Example 8: Evaluation of the upper adhesion of optical films] A 0.2 μm SiOx film was further deposited onto the optical film by a CVD process. 1 mm 2 100 cells were cross-cut at intervals, and the adhesive strength to the lower low-refractive-index optical film was compared using tape. The lower adhesion of the optical film was classified from 0 to 5B according to the classification criteria of the adhesion test results in Table 3, and is shown in Tables 5 to 7 below.

[0088] [Experimental Example 9: Evaluation of the heat resistance of optical films] Heat resistance was measured using TGA equipment (equipment name: Discovery TGA-55, TA KOREA). After sampling the pattern film formed during sensitivity measurement, measurements were taken using the TGA equipment while increasing the temperature from room temperature to 900°C at a rate of 10°C per minute, and the results are indicated in Tables 5-7 below using symbols according to the following criteria. ○: TGA 5wt% Weight loss (Temperature: 300℃ or higher) Δ: TGA 5wt% Weight loss at Temp. 270℃ to less than 300℃ X: TGA 5wt% Weight loss (Temperature below 270℃)

[0089] [Table 5]

[0090] [Table 6]

[0091] [Table 7]

[0092] From the results of Experimental Examples 1 to 9 shown in Tables 5 to 7, it was confirmed that the optical film according to the present invention has a very low refractive index, a very high average transmittance, low haze measurement values, high viscosity of the composition, a surface is formed at a nozzle temperature of 25 to 50°C using an inkjet device, a surface is formed even when coated using a slit coater, the adhesion to the top and bottom of the optical film is excellent, and the optical film itself also has excellent heat resistance.

[0093] The above description is merely illustrative, and a person with ordinary skill in the art to which the present invention pertains will understand that the present invention can be realized in modified forms without departing from its essential characteristics. Therefore, the disclosed embodiments should be considered in an explanatory rather than restrictive manner. The scope of the present invention is defined in the claims, not in the foregoing description, and all differences within an equivalent scope should be construed as being included within the present invention.

Claims

1. A thermosetting resin having a weight-average molecular weight of 1,000 to 200,000; D50 Particle size is 30 to 150 nm and surface-treated to a thickness of 3 to 50 nm; and A monomer or oligomer having a thermosetting functional group; The monomer or oligomer has two or more thermosetting functional groups, A thermosetting composition containing the gas-containing particles in an amount of 30 to 80% by weight relative to the total weight.

2. The thermosetting composition according to claim 1, wherein the thermosetting resin comprises at least one of epoxy groups, oxetane groups, or hydroxyl groups (OH).

3. The thermosetting composition according to claim 1, comprising 50 to 80% by weight of the gas-containing particles based on the total weight.

4. The thermosetting composition according to claim 1, wherein the gas-containing particles are pologen or hollow silica.

5. The thermosetting composition according to claim 1, wherein the gas-containing particles are surface-treated with one or more functional groups selected from the group consisting of alkyl groups, acrylic groups, methacrylic groups, epoxy groups, and vinyl groups.

6. The thermosetting composition according to claim 1, wherein the monomer or oligomer having the thermosetting functional group includes an alicyclic epoxy structure.

7. The thermosetting composition according to claim 1, wherein the monomer or oligomer having the thermosetting functional group comprises a compound having one chemical structure selected from the group consisting of the following chemical formulas 1 to 24: [Chemical formula 1] [Chemical formula 2] [Chemical formula 3] [Chemical formula 4] [Chemical formula 5] [Chemical formula 6] [Chemical formula 7] [Chemical formula 8] [Chemical formula 9] [Chemical formula 10] [Chemical formula 11] [Chemical formula 12] [Chemical formula 13] [Chemical formula 14] [Chemical formula 15] [Chemical formula 16] [Chemical formula 17] [Chemical formula 18] [Chemical formula 19] [Chemical formula 20] [Chemical formula 21] [Chemical formula 22] [Chemical formula 23] [Chemical formula 24] In chemical formulas 4 and 6 above, R independently represents a hydrocarbon group having 1 to 10 carbon atoms, and in chemical formulas 2 to 4, 11 to 13, and 20 to 21 above, l, m, n, and o independently represent integers from 1 to 30.

8. 1 to 69% by weight of the thermosetting resin; 30 to 80% by weight of the aforementioned gas-containing particles; and The thermosetting composition according to claim 1, comprising 1 to 60% by weight of a monomer or oligomer having the thermosetting functional group.

9. The thermosetting composition according to claim 1, wherein the total weight of the thermosetting resin and the monomer or oligomer having a thermosetting functional group is 20 to 70% by weight of the total composition.

10. The thermosetting composition according to claim 1, further comprising one or more additives selected from the group consisting of a silane coupling agent, an adhesive having an alkoxy group as a crosslinking site, and a surfactant.

11. The thermosetting composition according to claim 1, further comprising one or more dispersants selected from the group consisting of acrylic dispersants, epoxy dispersants, and silicone dispersants.

12. The thermosetting composition according to claim 1, further comprising one or more crosslinking accelerators selected from the group consisting of thermal acid generators and thermal base generators.

13. Diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, propylene glycol methyl ether propionate, propylene glycol ethyl ether propionate, propyl glycol propyl ether propionate, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol propyl ether, propylene glycol butyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, butylene glycol monomethyl ether, butylene glycol The thermosetting composition according to claim 1, comprising one or more solvents selected from the group consisting of monoethyl ether, dibutylene glycol dimethyl ether, dibutylene glycol diethyl ether, diethylene glycol butyl methyl ether, diethylene glycol butyl ethyl ether, triethylene glycol dimethyl ether, triethylene glycol butyl methyl ether, diethylene glycol t-butyl ether, tetraethylene glycol dimethyl ether, diethylene glycol ethylhexyl ether, diethylene glycol methylhexyl ether, dipropylene glycol butyl methyl ether, dipropylene glycol ethylhexyl ether, and dipropylene glycol methylhexyl ether.

14. The thermosetting composition according to claim 1, which is a solvent-free type that does not contain a solvent.

15. The thermosetting composition according to claim 1, wherein the viscosity is 3 to 30 cP.

16. Substrate and An optical member comprising a cured film cured with a thermosetting composition according to any one of claims 1 to 15.

17. The optical member according to claim 16, wherein the cured film has a haze of 3% or less with reference to light with a wavelength of 450 nm.

18. A display device comprising the optical member described in claim 16.

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