Anti-reflective paint and anti-reflective coating

Abstract

To provide an antireflection coating that is friendly to the environment and can be applied to substrates such as glass or resin.SOLUTION: An antireflection coating contains a binder resin, a water-soluble dye, and an aqueous solvent, the binder resin containing a urethane resin, and a silicone copolymer which is a copolymer of a silicone resin and an organic resin.SELECTED DRAWING: Figure 1

Description

Technical Field

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[0006]

[0001] The present invention relates to an antireflection paint and an antireflection coating film formed using the antireflection paint.

Background Art

[0002] <​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​While the light-shielding coating described in Patent Document 1 is suitably applicable to lenses and the like using cycloolefin polymers as a base material, there was room for improvement in its adhesion to other base materials such as glass. Furthermore, the light-shielding paint described in Patent Document 1 uses an organic solvent as the solvent, so there was room for improvement from the perspective of environmental impact. Therefore, the object of the present invention is to provide an anti-reflective coating that can be suitably applied to both glass substrates and resin substrates, and that reduces environmental impact. [Means for solving the problem]

[0007] The anti-reflective coating according to the present invention is an anti-reflective coating comprising a binder resin, a water-soluble dye, and an aqueous solvent, wherein the binder resin comprises a urethane resin and a silicone copolymer which is a copolymer of a silicone resin and an organic resin. Furthermore, the anti-reflective coating according to the present invention is an anti-reflective coating containing a binder resin and a water-soluble dye, wherein the binder resin is an anti-reflective coating containing a urethane resin and a silicone copolymer which is a copolymer of a silicone resin and an organic resin. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an anti-reflective coating that can be suitably applied to both glass substrates and resin substrates, and that reduces environmental impact. [Brief explanation of the drawing]

[0009] [Figure 1] (a) is a diagram showing the state immediately after applying the anti-reflective coating according to the present invention to the substrate surface, (b) is a diagram showing the transition process in which an anti-reflective coating film is formed from the anti-reflective coating according to the present invention applied to the substrate surface, and (c) is a diagram showing the anti-reflective coating film formed from the anti-reflective coating according to the present invention applied to the substrate surface. [Figure 2]This is a diagram illustrating the method for measuring diffuse reflectance in the example. [Modes for carrying out the invention]

[0010] The following describes embodiments for carrying out the present invention. Hereafter, anti-reflective paint may be simply referred to as "paint," and anti-reflective coating may be simply referred to as "coating."

[0011] The anti-reflective coating according to the present invention is an anti-reflective coating comprising a binder resin, a water-soluble dye, and an aqueous solvent, wherein the binder resin includes a urethane resin and a silicone copolymer which is a copolymer of a silicone resin and an organic resin.

[0012] The materials used in this invention will be described in more detail below.

[0013] <Binder resin> The binder resin contained in the anti-reflective coating according to the present invention comprises a urethane resin and a silicone copolymer.

[0014] [Urethane resin] Urethane resin can adhere to both glass and resin used in the substrates (hereinafter simply referred to as "substrates") of optical elements and other objects to which anti-reflective coatings are applied. In particular, it exhibits high adhesion to highly polar substrates such as glass, polycarbonate resin (PC), and acrylic resin (PMMA). Therefore, by using urethane resin as the resin contained in the coating, it is possible to suppress the peeling of the formed coating film from the substrate.

[0015] Furthermore, because urethane resin has excellent solvent resistance, when a substrate on which a coating film has formed on its surface is washed with an organic solvent during the manufacturing process, etc., the inclusion of urethane resin in the coating film makes it possible to reduce the dissolution of the coating film by the organic solvent.

[0016] Urethane resin is a high molecular weight compound obtained by addition polymerization reaction of polyisocyanate and polyol, and is used as a urethane resin emulsion dispersed in a solvent.

[0017] As the urethane resin emulsion, those commonly used in the art can be adopted without particular limitation. For example, the urethane resin emulsion can be obtained by reacting an excessive amount of polyisocyanate with polyol to form a urethane prepolymer, forcibly emulsifying it using a surfactant (external emulsifier), and then increasing the molecular weight with a chain extender and dispersing it in water. Also, monomers (internal emulsifiers) such as hydrophilic group-containing glycols and diamines can be introduced into the urethane prepolymer and dispersed in water to form a self-emulsifying type.

[0018] Examples of the external emulsifier include sodium alkylbenzene sulfonates, sodium dioctyl sulfosuccinate, quaternary ammonium salts, polyethylene glycol, propylene glycols, ethylene oxide adducts of long-chain alcohols and alkylphenols, and the like.

[0019] Examples of the internal emulsifier include compounds having one or more hydrophilic groups (sulfonate, carboxylate, quaternary ammonium salt, ethylene oxide, etc.) in the molecule and two reactive groups (hydroxyl group, amino group, etc.) that react with isocyanate groups.

[0020] Examples of the chain extender include glycols such as ethylene glycol, butanediol, and hexanediol as low molecular weight active hydrogen compounds, diamines such as ethylenediamine, propylenediamine, isophoronediamine, xylenediamine, 4,4'-diaminodicyclohexylmethane, and piperazine, amino alcohols such as diethanolamine, and water.

[0021] The polyisocyanate is not particularly limited as long as it is a compound having two or more isocyanate groups in one molecule. For example, aliphatic diisocyanates such as hexamethylene diisocyanate (HDI) and trimethylhexamethylene diisocyanate (TMDI); alicyclic diisocyanates such as isophorone diisocyanate (IPDI); aromatic-aliphatic diisocyanates such as xylylene diisocyanate (XDI); aromatic diisocyanates such as tolylene diisocyanate (TDI) and 4,4'-diphenylmethane diisocyanate (MDI); hydrogenated diisocyanates such as dimer acid diisocyanate (DDI), hydrogenated TDI (HTDI), hydrogenated XDI (H6XDI), and hydrogenated MDI (H12MDI); dimers, trimers, tetramers, and higher multimers of these. The polyisocyanate may be used alone or in combination of two or more.

[0022] The polyol is not particularly limited as long as it is a compound having two or more hydroxyl groups in one molecule. For example, polyhydric alcohols such as 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, ethylene glycol, propylene glycol, glycerin, and trimethylolpropane; relatively high molecular weight polypropylene glycol, polytetramethylene glycol, condensation type polyester polyol, lactone type polyester polyol, polycarbonate polyol, polybutadiene polyol, hydrogenated polybutadiene polyol, acrylic polyol, phosphorus-containing polyol, castor oil polyol, hydrogenated castor oil polyol, phenolic polyol, etc. The polyol may be used alone or in combination of two or more.

[0023] The urethane resin emulsion is used as a physical drying type that does not involve crosslinking during film formation. However, by dispersing the polyol and the polyisocyanate independently in water, it can also be used as a two-component curing type paint that undergoes crosslinking during film formation.

[0024] Examples of commercially available urethane resin emulsions include the ADEKA Bonditer HUX series (manufactured by ADEKA Corporation), the Hydran series, the Bondic series (manufactured by DIC Corporation), U-Coat UWS-145, U-Blenn UXA-37, the Permarine series (manufactured by Sanyo Chemical Industries, Ltd.), the ETARNACOLL UW series (manufactured by Ube Industries, Ltd.), the Takelac W, WPB, and WS series (manufactured by Mitsui Chemicals, Inc.), the DAOTAN series (manufactured by Daicel Ornex Co., Ltd.), and Superflex (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).

[0025] Examples of commercially available isocyanate dispersions include the Duranate W series (manufactured by Asahi Kasei Corporation), the Aquanate series (manufactured by Tosoh Corporation), and the Barnock DNW series (manufactured by DIC Corporation).

[0026] Examples of commercially available polyol dispersions include Barnock WD and the WE series (manufactured by DIC Corporation).

[0027] In the present invention, the content ratio of urethane resin to 100 parts by mass of binder resin is preferably 50 parts by mass or more and 98 parts by mass or less. If the content ratio of urethane resin to 100 parts by mass of binder resin is 50 parts by mass or more, excellent adhesion of the coating film to the substrate and solvent resistance can be obtained. Furthermore, if the content ratio of urethane resin to 100 parts by mass of binder resin is 98 parts by mass or less, room for the silicone copolymer described later can be left, and the film-forming properties of the anti-reflective coating can be improved.

[0028] [Silicone copolymer] A silicone copolymer is a copolymer of a silicone resin and an organic resin. The binder resin contained in the anti-reflective coating according to the present invention contains a silicone copolymer, which allows for excellent film-forming properties of the coating. The silicone copolymer is used as an emulsion of a silicone copolymer dispersed in a solvent, similar to a urethane resin.

[0029] While the above-mentioned urethane resin exhibits excellent adhesion to the substrate and solvent resistance, when used alone as a binder resin component in paint, it is difficult to uniformly apply the paint to the substrate when forming a coating film. In the present invention, by containing both urethane resin and a silicone copolymer as the binder resin in the paint, excellent adhesion of the coating film to the substrate and excellent solvent resistance can be obtained, in addition to excellent film-forming properties of the paint. This is presumed to be due to the effect of the silicone component in the silicone copolymer exhibiting a leveling effect on the entire binder resin, thereby improving the film-forming properties of the paint.

[0030] Furthermore, if, for example, only silicone resin is used together with urethane resin instead of silicone copolymer, there is a risk that the silicone resin may bleed onto the surface of the coating film and the interface between the coating film and the substrate after film formation. In particular, if the silicone resin bleeds onto the interface between the coating film and the substrate, the adhesion between the coating film and the substrate will decrease. In the present invention, the silicone copolymer has an organic resin portion in addition to the silicone resin portion, and the organic resin portion in the silicone copolymer has high affinity with the substrate and the urethane resin. Therefore, it is possible to suppress the bleeding of the silicone resin after film formation and improve film formation while maintaining high adhesion between the coating film and the substrate.

[0031] The mass ratio of silicone resin to organic resin in the silicone copolymer is preferably in the range of silicone resin:organic resin = 3:7 to 9:1. When the mass ratio of silicone resin to organic resin is within the range of silicone resin:organic resin = 3:7 to 9:1, it is possible to achieve a good balance between improved film formation and suppression of bleeding.

[0032] The mass ratio of urethane resin to silicone copolymer in the binder resin is preferably within the range of urethane resin:silicone copolymer = 75:25 to 98:2. If the ratio of the mass of the silicone copolymer to the total mass of the combined urethane resin and silicone copolymer is 25% or less, a high affinity between the urethane resin and the organic resin portion can be obtained. This makes it possible to obtain a high effect in suppressing the bleeding of the silicone component and the resulting bleeding of the dye, and a high solvent resistance can be obtained. Furthermore, if the ratio of the mass of the silicone copolymer to the total mass of the combined urethane resin and silicone copolymer is 2% or more, it is possible to improve the film-forming properties of the anti-reflective coating.

[0033] Examples of organic resins that constitute silicone copolymers include urethane resins, acrylic resins, polyether resins, polystyrene resins, polyolefin resins, polyester resins, epoxy resins, polycarbonate resins, polyimide resins, and cellulose-based resins.

[0034] In particular, the silicone copolymer is preferably at least one copolymer selected from a copolymer of silicone resin and acrylic resin, and a copolymer of silicone resin and urethane resin. Copolymers of silicone resin and acrylic resin, and copolymers of silicone resin and urethane resin, have high affinity with the substrate and urethane resin, and therefore can provide a more effective way to prevent the bleeding of the silicone component.

[0035] Examples of usable products containing silicone copolymers include: Charine E-370 (manufactured by Nisshin Chemical Industry Co., Ltd.), Charine LC-190 (manufactured by Nisshin Chemical Industry Co., Ltd.), Charine E-790 (manufactured by Nisshin Chemical Industry Co., Ltd.), Charine RU-911 (manufactured by Nisshin Chemical Industry Co., Ltd.), Acrit KS-3705 (manufactured by Taisei Fine Chemical Co., Ltd.), Ceranate WHW-822 (manufactured by DIC Co., Ltd.), Ceranate WSA-1070 (manufactured by DIC Co., Ltd.), Ceranate SSA-3060 (manufactured by DIC Co., Ltd.), Ceranate MFG-102 (manufactured by DIC Co., Ltd.), etc.

[0036] [Polyolefin resin] In the present invention, the binder resin may further contain a polyolefin resin. The polyolefin resin is used as an emulsion dispersed in a solvent, similar to urethane resins and silicone copolymers. Urethane resin exhibits particularly high adhesion to highly polar substrates such as glass, polycarbonate resin (PC), and acrylic resin (PMMA). However, it does not exhibit particularly high adhesion to low-polarity substrates, such as polyolefin resins like cycloolefin resins (COP, COC), polyethylene resin (PE), and polypropylene resin (PP). Therefore, by incorporating a polyolefin resin with structural compatibility with polyolefin resin substrates into the binder resin, it becomes possible to improve adhesion to low-polarity substrates such as polyolefin resins.

[0037] The olefin component in the polyolefin resin is not particularly limited, and known components can be used. Generally, the basic units include ethylene, propylene, and butene, and polymers of these, as well as copolymers using multiple components, form the main backbone of the olefin component.

[0038] The type of polyolefin resin is not particularly limited, but it is preferable to use an acid-modified polyolefin resin. An acid-modified polyolefin resin is a polyolefin resin that has been made aqueous by introducing hydrophilic functional groups such as carboxyl groups through modification with an unsaturated carboxylic acid or the like.

[0039] Examples of products containing polyolefin resins that may be included in the binder resin in the present invention include the following: Arrowbase SB-1230N (manufactured by Unitika), Arrowbase SE-1030N (manufactured by Unitika), Arrowbase SD-1205N (manufactured by Unitika), Arrowbase DA-1010N (manufactured by Unitika), Zaixen A (manufactured by Sumitomo Seika), Zaixen AC (manufactured by Sumitomo Seika), Zaixen AC-HW-10 (manufactured by Sumitomo Seika), Zaixen L (manufactured by Sumitomo Seika), Aurolene AE-301 (manufactured by Nippon Paper Industries), Aurolene AE-310 (manufactured by Nippon Paper Industries), Hardlen NZ-1015 (manufactured by Toyobo), etc.

[0040] The anti-reflective coating according to the present invention is an emulsion in which a binder resin is dispersed in an aqueous solvent. However, if the content of polyolefin resin in the binder resin increases, the stability of the emulsion state of the coating decreases. For this reason, the content ratio of polyolefin resin to 100 parts by mass of urethane resin in the binder resin is 100 parts by mass or less, preferably 12 parts by mass or less. Up to 100 parts by mass of polyolefin resin can be added to 100 parts by mass of urethane resin while maintaining the emulsion state of the paint. Furthermore, if the amount of polyolefin resin is 12 parts by mass or less per 100 parts by mass of urethane resin, the emulsion state of the resin contained in the paint can be maintained more stably while obtaining the effect of improving adhesion to low-polarity substrates.

[0041] [Water-soluble dye] In the present invention, when an anti-reflective coating is applied to a substrate, the water-soluble dye has the effect of suppressing reflection by absorbing visible light that is incident from the opposite side of the substrate coating surface and passes through the substrate, and also has the effect of blocking visible light.

[0042] Dyes generally include water-soluble dyes and hydrophobic dyes. Hydrophobic dyes include azo dyes such as Solvent Black 3 (e.g., OIL BLACK HBB (manufactured by Orient Chemical Industries Co., Ltd.)) and nigrosine dyes such as Solvent Black 7 (e.g., NUBIAN BLACK TN-870 (manufactured by Orient Chemical Industries Co., Ltd.)).

[0043] For example, if a hydrophobic dye as described above is used as the dye in the anti-reflective coating according to the present invention, it is difficult to uniformly disperse the dye in the solvent because the solvent contained in the coating is an aqueous solvent. Therefore, in order to ensure that the hydrophobic dye is uniformly dispersed in the binder resin, the anti-reflective coating may be prepared as follows. For example, the anti-reflective coating may be prepared by dispersing a binder resin, which has been pre-mixed with a hydrophobic dye, in an aqueous medium. Alternatively, the anti-reflective coating may be prepared by adding a small amount of hydrophobic dye to an aqueous solvent in which the binder resin is dispersed, while stirring thoroughly.

[0044] However, in this invention, from the viewpoint of solubility in aqueous solvents, the dye contained in the anti-reflective coating is a water-soluble dye. As a result, the dye can be easily dissolved in aqueous solvents and uniformly dispersed in the coating, so that by using the anti-reflective coating according to the present invention, an anti-reflective coating film with uniform and homogeneous anti-reflective performance can be formed.

[0045] In anti-reflective coatings, the content ratio of water-soluble dye per 100 parts by mass of binder resin is preferably 5 parts by mass or more and 25 parts by mass or less. If the content ratio of water-soluble dye is 5 parts by mass or more per 100 parts by mass of binder resin, a high light-absorbing effect as a water-soluble dye can be obtained, and the reflectivity of the formed coating film can be effectively reduced. If the content ratio of water-soluble dye is 25 parts by mass or less per 100 parts by mass of binder resin, the solvent resistance performance of the coating film can be maintained at a high level.

[0046] The water-soluble dye is preferably a black dye. One type of water-soluble dye may be used, or multiple types of dyes, such as red, yellow, and blue dyes, may be used in combination, adjusting the absorption wavelength.

[0047] As for water-soluble dyes, there are no restrictions as long as the anti-reflective properties of the coating film are maintained, and any known dyes with wavelength absorption characteristics corresponding to the desired absorption wavelength can be arbitrarily selected and used.

[0048] Examples of water-soluble dyes include azo dyes, metal complex dyes, naphthol dyes, anthraquinone dyes, indigo dyes, carbonium dyes, quinoneimine dyes, xanthene dyes, cyanine dyes, quinoline dyes, nitro dyes, nitroso dyes, benzoquinone dyes, naphthoquinone dyes, phthalocyanine dyes, metal phthalocyanine dyes, and nigrosine dyes.

[0049] Specific examples of water-soluble dyes added for the purpose of absorbing light in the visible wavelength range include azo dyes such as WATER COLOR (manufactured by Orient Chemical Industry Co., Ltd.) and metallic dyes such as Aizen Spilon Black -1 W-Liquid (manufactured by Hodogaya Chemical Co., Ltd.). In particular, azo dyes are preferred because they have a wide absorption wavelength range in the visible light region and exhibit excellent solubility in various solvents. Examples of water-soluble azo dyes include the WATER COLOR Series (manufactured by Orient Chemical Industry Co., Ltd.), and the desired absorption wavelength and color can be adjusted by selecting from the appropriate series, such as Black, Yellow, Red, Green, Orange, Pink, Blue, and Violet.

[0050] <Aqueous solvent> In the present invention, the aqueous solvent is a solvent mainly composed of water, such as ion-exchanged water, pure water, purified water, or distilled water. The aqueous solvent may optionally include water-soluble or water-miscible organic solvents such as alcohol-based solvents, ester-based solvents, ketone-based solvents, or amide-based solvents.

[0051] The proportion of aqueous solvent in the paint (dilution ratio) can be adjusted as needed to suit the application. For example, it can be adjusted appropriately when controlling the film thickness depending on the application method, such as spraying, dipping, or brush painting, or when controlling the film thickness depending on the intended use. Furthermore, the dilution ratio may be changed as needed to adjust the viscosity of the paint to the desired level.

[0052] The viscosity of the anti-reflective coating can be adjusted according to the desired film thickness and to prevent dripping after application, but it is preferably between 3 mPa·s and 1,000 mPa·s. If the viscosity of the anti-reflective coating is 3 mPa·s or higher, dripping is suppressed and the film thickness can be easily controlled. If the viscosity of the anti-reflective coating is 1,000 mPa·s or lower, variations in film thickness and foaming can be suppressed. Furthermore, a mixture of multiple solvents may be used to control the drying speed after the anti-reflective coating has been applied.

[0053] The anti-reflective coating according to the present invention is an emulsion in which a binder resin is dispersed in an aqueous solvent. The water-soluble dye dissolves in the aqueous solvent and is dispersed throughout the coating. The process from applying the coating to the substrate surface to drying and solidifying to form a coating film will be explained using Figures 1(a) to (c).

[0054] Figure 1(a) is a schematic diagram showing the state immediately after applying the anti-reflective coating 1 according to the present invention to the surface of a substrate 2. The water-soluble dye 4 is dissolved in the aqueous solvent 5 and exists between the dispersed particles of the binder resin 3 contained in the anti-reflective coating 1. Therefore, the smaller the particle size of the dispersed particles of the binder resin 3, the more uniformly the water-soluble dye 4 can be distributed throughout the anti-reflective coating 1.

[0055] Next, during the drying and solidification process, the aqueous solvent 5 evaporates and disappears, and as shown in Figure 1(b), the water-soluble dye 4 remains between the dispersed particles of the binder resin 3. Subsequently, the particles fuse together to form a film, and as shown in Figure 1(c), the water-soluble dye 4 becomes dispersed in the anti-reflective coating 6 at the positions where it remained between the dispersed particles of the binder resin 3.

[0056] In other words, if the dispersed particles of the binder resin 3 are large, the water-soluble dye 4 will be dispersed around the larger dispersed particles, resulting in an uneven distribution of the water-soluble dye 4 in the formed anti-reflective coating 6. Therefore, it is preferable for the dispersed particles of the binder resin 3 in the anti-reflective coating 1 to be as small as possible. Specifically, the volume-based median diameter (D50) of the dispersed particles of the binder resin in the aqueous solvent is preferably 0.1 μm or less. Hereafter, the median diameter (D50) will always be volume-based. As described above, the smaller the median diameter (D50), the more uniformly the water-soluble dye 4 in the anti-reflective coating 6 will be dispersed, and the anti-reflective performance of the anti-reflective coating 6 will improve.

[0057] In the above, for example, it is conceivable to disperse the binder resin in an aqueous solvent as solid resin particles rather than as an emulsion. In this case, by making the particle size of the resin particles small beforehand, the water-soluble dye can be uniformly dispersed in the coating film. However, when using solid resin particles, high-temperature heating is required during film formation, and if a resin lens is used as the substrate, the substrate may dissolve, leading to molding defects.

[0058] <Other additives> Anti-reflective coatings may contain other additives as needed, within the limits of maintaining their anti-reflective properties. Other additives that coatings may contain include pH adjusters, thixotropes, thickeners, defoamers, film-forming aids, dispersion stabilizers, dispersants, crosslinking agents, adhesion promoters, surfactants, leveling agents, organic microparticles, inorganic microparticles, preservatives, and fungicides.

[0059] Among these, thickeners can be used to adjust the viscosity of anti-reflective coatings, thereby controlling the film thickness when applying them to a substrate and preventing dripping after application. Examples of thickeners include hydrogenated castor oil-based, polyethylene oxide-based, amide-based, and polyether-based waxes, as well as organic types such as ethylcellulose, hydroxyethylcellulose, polyether-modified urethane compounds, polyurethane copolymers, polyacrylates, and acrylic acid / methacrylic acid copolymers, and inorganic types such as silica-based, montmorillonite-based, and calcium carbonate-based thickeners.

[0060] If the pH of the materials used differs, it is preferable to equalize the pH of each material using a pH adjusting agent before mixing them together. Mixing materials with significantly different pH values ​​may result in the formation of aggregates over time. This is thought to be because mixing materials with significantly different pH values ​​in the mixture causes fluctuations in the stability of the emulsion, leading to partial aggregation over time. For example, when using a binder resin that is neutral to weakly basic with a thickening agent containing acidic acrylic acid, it is preferable to adjust the thickening agent to neutral to weakly basic using a pH adjusting agent before mixing it with the binder resin.

[0061] Furthermore, to increase the strength of the coating film, the paint may contain crosslinking agents including epoxy groups and carbodiimide groups. These crosslinking agents are known to react with the active hydrogen groups of the resin emulsion to form a crosslinked structure. Examples of active hydrogen groups include hydroxyl groups and carboxyl groups. One type of these crosslinking agent may be used, or two or more types may be used simultaneously.

[0062] Examples of preservatives and fungicides include benzimidazole, isothiazolyl, haloallylsulfone, iodopropargyl, benzothiazole, phenol, triazine, adamantane, and pyridine compounds.

[0063] <Method for manufacturing anti-reflective coating> The anti-reflective coating according to the present invention can be manufactured by mixing a binder resin, a water-soluble dye, an aqueous solvent, and other materials. Mixing can be carried out by known methods, for example, using a magnetic stirrer, propeller agitator, ball mill, paint shaker, basket mill, Dyno mill, Ultravisco mill, annular disperser, etc.

[0064] <Anti-reflective coating> The anti-reflective coating according to the present invention is a coating formed using the anti-reflective paint according to the present invention as described above. The thickness of the anti-reflective coating is preferably 0.5 μm or more and 100 μm or less. If the thickness of the anti-reflective coating is 0.5 μm or more, visible light incident from the opposite side of the coated surface of the substrate and then transmitted through the substrate can be effectively absorbed, resulting in a high level of reflection suppression and light shielding effect. Furthermore, if the thickness of the anti-reflective coating is 100 μm or less, variations in film thickness can be suppressed when the anti-reflective coating is formed.

[0065] <Method for manufacturing an anti-reflective coating> The anti-reflective coating according to the present invention can be manufactured by applying the anti-reflective paint according to the present invention, as described above, to a substrate and then drying it. As the substrate on which the coating film is to be formed, known materials such as glass and resin can be used. The method of forming the coating film is not particularly limited, and any known coating method may be used. Examples of coating methods include spraying, brushing, rolling, roll coating, applicator, wire bar (bar coater), dip coating, and sponge coating. Furthermore, the drying method can be any method in which the solvent evaporates and the dispersed resin particles used subsequently fuse together. A known drying method can be selected according to the application and the required drying speed. Examples of known drying methods include electric furnaces, hot air, and far-infrared radiation. [Examples]

[0066] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. Table 1 shows the materials used in each example and comparative example. Table 2 shows the types of substrates used as the target for coating with the anti-reflective coating.

[0067] [Table 1] In Table 1, the median diameter (D50) (μm) is the value for the dispersed particles of the corresponding resin.

[0068] [Table 2]

[0069] (Example 1) <Preparation of anti-reflective coating> For every 100 parts by mass of anti-reflective coating, the materials were prepared such that the solid content of urethane A was 21.7 parts by mass, the solid content of silicone copolymer A was 2.4 parts by mass, the solid content of dye A was 2.7 parts by mass, and the solvent (total of the solvent contained in the binder resin product, the solvent contained in the dye product, and the main solvent) was 73.2 parts by mass. Next, the prepared materials were placed in a 100 mL beaker, and the REV. CONTROL was set to "3" on a stirrer (MULTI MAGNETIC STIRRER HSD-4: manufactured by AS ONE) and stirred for 10 minutes to obtain an anti-reflective coating. The materials used in Example 1 and the proportions of each material are shown in Table 3.

[0070] <Fabrication of anti-reflective coatings> The anti-reflective coating obtained from the above preparation was applied to substrate B using a wire bar (wet film thickness 12 μm), and dried at 80°C for 30 minutes to produce an anti-reflective coating film.

[0071] (Examples 2-16, 18, 20, 22-38, 40, 42, 44-52, 54, 56, 60, 61, Comparative Examples 1-12) In Example 1, the paint was prepared in the same manner as in Example 1, except that the type and amount of materials used, the type of substrate used, and the film thickness were changed as shown in Tables 3 to 6. Furthermore, a coating film was prepared using the obtained paint in the same manner as in Example 1.

[0072] (Example 17) <Preparation of anti-reflective coatings and fabrication of anti-reflective coatings> For 100 parts by mass of anti-reflective coating, the materials were prepared as follows: 19.1 parts by mass of urethane A, 2.1 parts by mass of silicone copolymer A, 2.4 parts by mass of dye A, 76.2 parts by mass of solvent (total of solvent contained in the binder resin product, solvent contained in the dye product, and main solvent), and 0.2 parts by mass of thickener solids. Next, the thickener and a portion of the main solvent (11.7 parts by mass) from the prepared materials were placed in a 100 mL beaker and allowed to swell for 18 hours. Then, using a propeller stirrer (Pencil Mixer DX: manufactured by AS ONE), the mixture was stirred at 7000 rpm for 60 minutes to obtain the thickener solution. The binder resin (including the solvent contained in the product), the thickener solution, and the remaining main solvent were placed in a 100 mL beaker and stirred for 45 minutes using a stirrer (MULTI MAGNETIC STIRRER HSD-4: manufactured by AS ONE) with the REV.CONTROL set to "5". After that, dye A (including the solvent contained in the product) was added and stirred for 15 minutes using the stirrer under the above conditions to obtain the anti-reflective coating. The materials used in Example 17 and the proportions of each material are shown in Table 3. Furthermore, a coating film was prepared using the obtained coating in the same manner as in Example 1.

[0073] (Examples 19, 21, 39, 41, 43, 53, 55, 57-59) In Example 17, the paint was prepared in the same manner as in Example 17, except that the type and amount of materials used, the type of substrate used, and the film thickness were changed as shown in Tables 3 to 5. Furthermore, using the obtained paint, a coating film was prepared in the same manner as in Example 1, except that a wire bar corresponding to the film thickness of each example was selected.

[0074] (Example 62) <Preparation of anti-reflective coatings and fabrication of anti-reflective coatings> For 100 parts by mass of anti-reflective coating, the materials were prepared as follows: 17.1 parts by mass of urethane A, 1.9 parts by mass of silicone copolymer A, 2.1 parts by mass of dye A, 78.4 parts by mass of solvent (total of solvent contained in the binder resin product, solvent contained in the dye product, and main solvent), 0.2 parts by mass of thickener, and 0.2 parts by mass of pH adjuster. Next, the thickener and a portion of the main solvent (11.7 parts by mass) from the prepared materials were placed in a 100 mL beaker and allowed to swell for 18 hours. Then, using a propeller stirrer (Pencil Mixer DX: manufactured by AS ONE), the mixture was stirred at 7000 rpm for 60 minutes to obtain a thickener solution. A pH adjuster and a portion of the main solvent (9.0 parts by mass) were added to the thickener solution, and the mixture was stirred for 10 minutes using a stirrer (MULTI MAGNETIC STIRRER HSD-4: manufactured by AS ONE) with the REV.CONTROL set to "5" to obtain a pH-adjusted thickener solution. Urethane A (including the solvent contained in the product), the pH-adjusted thickener solution, and the remaining main solvent were placed in a 100 mL beaker and stirred for 45 minutes using the stirrer under the conditions described above. After that, dye A (including the solvent contained in the product) was added, and the mixture was stirred for 15 minutes using the stirrer under the conditions described above to obtain an anti-reflective coating. Table 5 shows the materials used in Example 62 and the proportions of each material. Furthermore, a coating film was prepared using the obtained paint in the same manner as in Example 1.

[0075] (Example 63) In Example 62, the paint was prepared in the same manner as in Example 62, except that the type and amount of materials used, the type of substrate used, and the film thickness were changed as shown in Table 5. Furthermore, using the obtained paint, a coating film was prepared in the same manner as in Example 1, except that a wire bar corresponding to the film thickness of Example 63 was selected.

[0076] <Measurement> [Median diameter (D50) of dispersed particles in the binder resin] The volume-based median diameter (D50) of the dispersed particles in the binder resin was measured using a particle size distribution analyzer (product name: Nanotrac WAVE-EZ150, manufactured by Nikkiso Co., Ltd.) as follows. The sample to be measured was diluted 500 times with deionized water, stirred and mixed for 1 minute using a stirrer, and then placed in the above measuring device to measure the particle size distribution. From the obtained results, the volume-based median diameter (D50) was determined. The measurement results are shown in Tables 3-6.

[0077] 〔viscosity〕 The viscosity of the anti-reflective coating was measured using a TVB-15 viscometer (manufactured by Toki Sangyo Co., Ltd.) with an L adapter attached, at a temperature of 23±1℃. The rotor rotation speed was appropriately adjusted to be optimal according to the viscosity of the liquid being measured. The measurement results are shown in Tables 3-6.

[0078] <Evaluation of anti-reflective coatings> The anti-reflective coatings prepared using the anti-reflective coatings in each example and comparative example were evaluated as follows.

[0079] [Adhesion] The adhesion between the anti-reflective coatings prepared in each example and comparative example and the substrate was evaluated as follows using the cross-cut method (JIS K 5600-5-6:1999). A: In the crosscut evaluation, "Classification: 0" or "Classification: 1" B: In the crosscut evaluation, "Category: 2" or "Category: 3" C: In the cross-cut evaluation, "Category: 4" or "Category: 5" The evaluation results are shown in Tables 3-6.

[0080] <Reference: Evaluation according to JIS K 5600-5-6:1999> 0: The edges of the cut are perfectly smooth, and there is no peeling at any of the grid lines. 1: Small peeling of the paint film at the intersection of the cuts. The percentage of areas affected at the cross-cuts does not clearly exceed 5%. 2: The paint film is peeling along the edges of the cuts and / or at the intersections. The affected area in the cross-cut is clearly more than 5%, but never exceeds 15%. 3: The paint film is partially or completely peeling along the edges of the cuts, and / or various parts of the eye are partially or completely peeling. The affected area in the cross-cut section is clearly more than 15%, but not more than 35%. 4: The paint film is partially or completely peeling along the edges of the cuts, and / or peeling in several places, either partially or completely. The affected area in the cross-cut sections does not clearly exceed 35%. 5: Any of the following types of peeling that cannot be classified as Category 4.

[0081] [Film formability] The film-forming properties were confirmed using the anti-reflective coatings prepared in each example and comparative example. The surface condition of the formed films was evaluated by visual observation as follows. A: The surface is uniform with no repulsion, cracking, or unevenness with respect to the substrate. B: There is no repellency or cracking with the substrate, but slight unevenness in film thickness is visible. C: Repulsion from the substrate, cracking, or significant unevenness in film thickness are observed. The evaluation results are shown in Tables 3-6.

[0082] [Solvent resistance] The anti-reflective coatings prepared in each example and comparative example were used as test specimens, and the surface of the anti-reflective coating was rubbed 30 times (back and forth) using cleaning paper (Dasper K-3, manufactured by Ozu Sangyo Co., Ltd.) soaked in isopropyl alcohol. After that, visual observation was performed and the following evaluation was made. A: No color fading, or very slight color fading. B: There is some color fading, but it is at a level that does not affect practical use. C: The color has faded significantly, or the film has peeled off. The evaluation results are shown in Tables 3-6.

[0083] [Anti-reflection performance] To evaluate the anti-reflective performance, the diffuse reflectance was measured as follows. The anti-reflective coatings prepared in each example and comparative example were used as test specimens, and their diffuse reflectance was measured using a spectrophotometer (product name: V-670, manufactured by JASCO Corporation) equipped with an ILN-725 type 150 mmφ integrating sphere unit. In the measurement, the test specimen was set up as shown in Figure 2, and the incident angle 14 was set to a specific value relative to the normal 15 extending perpendicular to the surface of the test specimen. The average reflectance was calculated by irradiating the specimen with incident light 10 at wavelengths from 400 nm to 700 nm in 1 nm increments. Since the reflected light includes both specularly reflected light 11 reflected from the surface of the slide glass and diffusely reflected light that is transmitted through the slide glass and reflected from the inner surface of the coating, the integrating sphere unit was used to remove the specularly reflected light 11, and the diffusely reflected light 13, which does not contain specular reflection, was measured. The obtained measurement results were evaluated as follows. A: The reflectivity is "0.15% or less," making it extremely effective at preventing reflections. B: The reflectivity is "greater than 0.15% and less than or equal to 0.25%", indicating excellent anti-reflective properties. C: The reflectivity is "greater than 0.25%", indicating insufficient anti-reflective properties. The evaluation results are shown in Tables 3-6.

[0084] 〔comprehensive evaluation〕 The overall evaluation was conducted as follows, using evaluations of adhesion, film formation properties, solvent resistance, and anti-reflective performance. A: Everything is rated "A". B: Includes at least a rating of "B" and does not include a rating of "C". C: There is one or more items with a rating of "C". The evaluation results are shown in Tables 3-6. [Table 3]

[0085] [Table 4]

[0086] [Table 5]

[0087] [Table 6] [Explanation of symbols]

[0088] 1.Anti-reflective paint 2. Base material 3. Binder resin 4.Water soluble dye 5. Aqueous solvent 6.Anti-reflective coating 7. Test specimen 10.Incoming light 11.Specular reflection light 12.Transmitted light 13. Diffuse reflected light 14.Angle of incidence 15. Normal vector

Claims

1. An anti-reflective coating comprising a binder resin, a water-soluble dye, and an aqueous solvent, The binder resin includes a urethane resin and a silicone copolymer which is a copolymer of a silicone resin and an organic resin. The mass ratio of the urethane resin to the silicone copolymer in the binder resin is within the range of urethane resin:silicone copolymer = 70:30 to 99:

1. The silicone copolymer is at least one copolymer selected from a copolymer of a silicone resin and an acrylic resin, and a copolymer of a silicone resin and a urethane resin. An anti-reflective coating in which the mass ratio of the silicone resin to the organic resin in the silicone copolymer is in the range of silicone resin:organic resin = 3:7 to 9:

1.

2. The anti-reflective coating according to claim 1, wherein the content ratio of the urethane resin to 100 parts by mass of the binder resin is 50 parts by mass or more and 98 parts by mass or less.

3. The anti-reflective coating according to claim 1 or 2, wherein the mass ratio of the urethane resin to the silicone copolymer is in the range of urethane resin:silicone copolymer = 75:25 to 98:

2.

4. The anti-reflective coating according to any one of claims 1 to 3, wherein the binder resin further comprises a polyolefin resin.

5. The anti-reflective coating according to claim 4, wherein the content ratio of the polyolefin resin to 100 parts by mass of the urethane resin is 12 parts by mass or less.

6. The anti-reflective coating according to any one of claims 1 to 5, wherein the volume-based median diameter (D50) of the dispersed particles of the binder resin in the aqueous solvent is 0.1 μm or less.

7. The anti-reflective coating according to any one of claims 1 to 6, wherein the content ratio of the water-soluble dye to 100 parts by mass of the binder resin is 5 parts by mass or more and 25 parts by mass or less.

8. The anti-reflective coating according to any one of claims 1 to 7, wherein the water-soluble dye is an azo dye.

9. The anti-reflective coating according to any one of claims 1 to 8, wherein the viscosity of the anti-reflective coating is 3 mPa·s or more and 1,000 mPa·s or less.

10. An anti-reflective coating containing a binder resin and a water-soluble dye, The binder resin includes a urethane resin and a silicone copolymer which is a copolymer of a silicone resin and an organic resin. The mass ratio of the urethane resin to the silicone copolymer in the binder resin is within the range of urethane resin:silicone copolymer = 70:30 to 99:

1. The silicone copolymer is at least one copolymer selected from a copolymer of a silicone resin and an acrylic resin, and a copolymer of a silicone resin and a urethane resin. An anti-reflective coating film in which the mass ratio of the silicone resin to the organic resin in the silicone copolymer is in the range of silicone resin:organic resin = 3:7 to 9:

1.

11. The anti-reflective coating according to claim 10, wherein the content ratio of the urethane resin to 100 parts by mass of the binder resin is 50 parts by mass or more and 98 parts by mass or less.

12. The anti-reflective coating according to claim 10 or 11, wherein the mass ratio of the urethane resin to the silicone copolymer is urethane resin:silicone copolymer = 75:25 to 98:

2.

13. The anti-reflective coating according to any one of claims 10 to 12, wherein the binder resin further comprises a polyolefin resin.

14. The anti-reflective coating according to claim 13, wherein the content ratio of the polyolefin resin to 100 parts by mass of the urethane resin is 12 parts by mass or less.

15. The anti-reflective coating according to any one of claims 10 to 14, wherein the content ratio of the water-soluble dye to 100 parts by mass of the binder resin is 5 parts by mass or more and 25 parts by mass or less.

16. The anti-reflective coating according to any one of claims 10 to 15, wherein the water-soluble dye is an azo dye.

17. The anti-reflective coating according to any one of claims 10 to 16, wherein the thickness of the anti-reflective coating is 0.5 μm or more and 100 μm or less.

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