Coating liquid for spray coating and method for manufacturing the same, and method for manufacturing a substrate with an anti-glare layer.

Abstract

To provide a coating liquid for spray coating capable of suppressing sparkles in an antiglare surface of an uneven structure, when forming an antiglare layer according to a spray coating method.SOLUTION: Provided is a coating liquid for spray coating containing a silica precursor and a solvent, wherein a molecular size of the silica precursor is 5.6 nm or more as an average value based on scattered light intensity measured by a dynamic light scattering method.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a coating liquid for spray coating, a method for producing the same, and a method for producing a substrate with an antiglare layer using the coating liquid for spray coating.

Background Art

[0002] Conventionally, in displays such as mobile phones, tablet terminals, televisions, or digital signage, the visibility may be reduced when a reflected image is projected onto the display surface by external light such as indoor lighting (fluorescent lamps, etc.) or sunlight. As a process for suppressing such reflection by external light, an antiglare process and an antireflection process are known.

[0003] Patent Document 1 below discloses a transparent article including a transparent substrate and an antiglare layer provided on at least one surface of the transparent substrate. In Patent Document 1, an antiglare layer is formed by applying a coating agent containing a matrix precursor by a spray coating method. As the matrix precursor, at least one selected from SiO2, Al2O3, ZrO2, and TiO2 is used.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when an antiglare layer is formed by applying a coating agent containing a matrix precursor by a spray coating method as in Patent Document 1, glitter called sparkle may occur on the antiglare surface. Therefore, there is a problem that the visibility of the display cannot be sufficiently improved.

[0006] The object of the present invention is to provide a spray coating liquid that can suppress sparkling on an anti-glare surface with an uneven structure when an anti-glare layer is formed by a spray coating method, a method for producing the spray coating liquid, and a method for producing a substrate with an anti-glare layer using the spray coating liquid. [Means for solving the problem]

[0007] The coating liquid for spray coating according to the present invention is a coating liquid for spray coating comprising a silica precursor and a solvent, characterized in that the molecular size of the silica precursor is 5.6 nm or larger on average, based on the scattered light intensity measured by dynamic light scattering.

[0008] In the present invention, it is preferable that the molecular size of the silica precursor is 30 nm or less, based on the average value of the scattered light intensity measured by dynamic light scattering.

[0009] The method for producing a spray coating liquid according to the present invention is a method for producing a spray coating liquid configured in accordance with the present invention, characterized by comprising the steps of: preparing a mixed solution containing the silica precursor raw material and a solvent; and maturing the prepared mixed solution.

[0010] In the present invention, it is preferable that the raw material for the silica precursor is a monomer or oligomer of an alkoxysilane.

[0011] In the present invention, it is preferable that the alkoxysilane is tetramethoxysilane or tetraethoxysilane.

[0012] In the present invention, it is preferable that the mixed liquid further contains oxide fine particles, and the content of the oxide fine particles is less than 0.05% by mass.

[0013] In the present invention, it is preferable that the silica precursor is a matrix-forming component when forming an anti-glare layer by a spray coating method, and that the oxide fine particles are components different from the matrix-forming component.

[0014] In the present invention, it is preferable that the content of components in the mixed liquid having a boiling point greater than 100°C and less than 120°C is 0% by mass or more and 15% by mass or less.

[0015] In the present invention, it is preferable that the content of components with a boiling point of 120°C or higher in the mixed liquid is 5% by mass or less.

[0016] The method for manufacturing a substrate with an anti-glare layer according to the present invention is characterized by comprising the steps of: preparing a spray coating liquid by a method for manufacturing a spray coating liquid configured according to the present invention; and forming an anti-glare layer by applying the spray coating liquid onto a substrate.

[0017] In the present invention, it is preferable to apply the spray coating liquid using a two-fluid spray gun. [Effects of the Invention]

[0018] According to the present invention, it is possible to provide a spray coating liquid that can suppress sparkling on an anti-glare surface with an uneven structure when an anti-glare layer is formed by a spray coating method, a method for producing the spray coating liquid, and a method for producing a substrate with an anti-glare layer using the spray coating liquid. [Brief explanation of the drawing]

[0019] [Figure 1] Figure 1 shows the relationship between maturation time and the molecular size of the silica precursor at maturation temperatures of 20°C and 45°C. [Figure 2]FIG. 2 is a diagram showing the relationship between the aging time and the molecular size of the silica precursor in terms of the amount of alcohol during aging of various coating liquids. [Figure 3] FIGS. 3(a) and 3(b) are schematic cross-sectional views for explaining a method for manufacturing a substrate with an antiglare layer according to an embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0020] Hereinafter, preferred embodiments will be described. However, the following embodiments are merely illustrative, and the present invention is not limited to the following embodiments.

[0021] [Coating Liquid for Spray Coating] The coating liquid for spray coating of the present invention is a coating liquid for forming a coating film by the spray coating method. The coating liquid for spray coating (hereinafter simply referred to as "coating liquid") is not particularly limited, but for example, it is used for forming an antiglare layer by the spray coating method. The antiglare layer is a layer provided to impart a so-called antiglare effect that suppresses the reflection of external light and the like.

[0022] The coating liquid of the present invention contains a silica precursor and a solvent. Further, the molecular size of the silica precursor contained in the coating liquid is 5.6 nm or more in terms of the average value based on the scattered light intensity measured by the dynamic light scattering method.

[0023] Furthermore, the measurement of scattered light intensity using dynamic light scattering can be performed, for example, using a Malvern Panalytical product, model number "Zetasizer Nano S". The measurement can be performed, for example, at a fixed position where the average scattering intensity is 500 kcps, with an execution time of 3 seconds and 30 executions, averaging over 45 measurements, and calculating the particle size distribution using the non-negative least squares method to obtain the average value based on scattered light intensity. Other parameters can be measured and analyzed with a measurement temperature of 20.0°C, 70 size classes, a particle size distribution lower limit of 0.4, a display upper limit of 10000, a lower threshold of 0.05, an upper threshold of 0.01, standard resolution, a display range lower limit of 0.6, and a display range upper limit of 300. It is desirable to use the coating liquid immediately before spray coating for the measurement.

[0024] According to the coating liquid of the present invention, when an anti-glare layer is formed by a spray coating method, sparkling on the uneven anti-glare surface can be suppressed. Therefore, when such an anti-glare layer is used in a display or the like, visibility can be further improved.

[0025] Conventionally, when a coating agent containing a matrix precursor was applied by a spray coating method to form an anti-glare layer, glare known as sparkle sometimes occurred on the anti-glare surface. Therefore, there was a problem in that the visibility of the display could not be sufficiently improved.

[0026] In response to this, the inventors focused on the molecular size of the silica precursor contained in the coating solution and found that by setting this molecular size to 5.6 nm or more based on the average value of scattered light intensity measured by dynamic light scattering, sparkle can be suppressed on the anti-glare surface with an uneven structure.

[0027] In the present invention, the molecular size of the silica precursor contained in the coating liquid is 5.6 nm or larger, preferably 7.0 nm or larger, and more preferably 8.0 nm or larger, based on the average value of scattered light intensity measured by dynamic light scattering. When the molecular size of the silica precursor is greater than or equal to the above lower limit, sparkling on the anti-glare surface with an uneven structure can be further suppressed.

[0028] Furthermore, in the present invention, the molecular size of the silica precursor contained in the coating liquid is preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 18 nm or less, based on the average value of scattered light intensity measured by dynamic light scattering. When the molecular size of the silica precursor is below the above upper limit, the increase in haze can be further suppressed and the degree of cloudiness can be further reduced when an anti-glare layer is formed by the spray coating method. Therefore, when such an anti-glare layer is used in a display or the like, visibility can be further improved.

[0029] The silica precursor contained in the coating solution of the present invention can be used, for example, as a matrix-forming component when forming an anti-glare layer by a spray coating method.

[0030] The following describes in detail each component contained in the coating solution of the present invention.

[0031] (Silica precursor) Examples of silica precursors include hydrolysis condensates of silane compounds and silazane compounds having hydrolyzable groups bonded to silicon atoms. It is preferable that the silica precursor contains at least a hydrolysis condensate of a silane compound, as this can more reliably suppress cracks in the anti-glare layer even when a thick anti-glare layer is formed.

[0032] Examples of raw materials for silica precursors include silane compounds and silazane compounds.

[0033] Silane compounds have hydrolyzable groups bonded to silicon atoms.

[0034] Examples of hydrolyzable groups include alkoxy groups, acyloxy groups, ketoxime groups, alkenyloxy groups, amino groups, aminooxy groups, amide groups, isocyanate groups, and halogen atoms. From the viewpoint of balancing the stability of the silane compound with the ease of hydrolysis, alkoxy groups, isocyanate groups, or halogen atoms (especially chlorine atoms) are preferred. As for alkoxy groups, alkoxy groups having 1 to 3 carbon atoms are preferred, and methoxy groups or ethoxy groups are more preferred.

[0035] Examples of silane compounds include alkoxysilanes such as tetramethoxysilane, tetraethoxysilane, and tetraisopropoxysilane; alkoxysilanes having alkyl groups such as methyltrimethoxysilane and ethyltriethoxysilane; alkoxysilanes having vinyl groups such as vinyltrimethoxysilane and vinyltriethoxysilane; alkoxysilanes having epoxy groups such as 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane; and alkoxysilanes having acryloyloxy groups such as 3-acryloyloxypropyltrimethoxysilane. Among these silane compounds, it is preferable to use either an alkoxysilane or a hydrolysis condensate of an alkoxysilane, or both, and it is more preferable to use a hydrolysis condensate of an alkoxysilane.

[0036] Furthermore, hydrolysis condensates of alkoxysilanes include silicate oligomers obtained by pre-polymerizing the monomers of the alkoxysilanes listed above. In this case, the anti-glare effect of the anti-glare layer formed by the spray coating method can be further enhanced.

[0037] Silazane compounds are compounds that have a silicon-nitrogen bond (-SiN-) in their structure. Silazane compounds can be low molecular weight compounds or high molecular weight compounds (polymers having a predetermined repeating unit). Examples of low molecular weight silazane compounds include hexamethyldisilazane, hexaphenyldisilazane, dimethylaminotrimethylsilazane, trisilazane, cyclotrisilazane, and 1,1,3,3,5,5-hexamethylcyclotrisilazane.

[0038] The silica precursor content is preferably 1% by mass or more, more preferably 2% by mass or more, preferably 8% by mass or less, and more preferably 5% by mass or less, based on the total amount of coating solution and calculated as SiO2 content. When the silica precursor content is within the above range, the anti-glare effect of the anti-glare layer formed by the spray coating method can be further enhanced.

[0039] (solvent) The solvent can be appropriately selected depending on the type of silica precursor and is not particularly limited. For example, water or alcohols, as described later, can be used as solvents.

[0040] water; Water may be used alone as a solvent, but a mixture of water and another solvent is preferred. A mixture of water and alcohols is even more preferred.

[0041] The water content when manufacturing the coating liquid for spray coating is preferably 2.7% by mass or more, more preferably 4.0% by mass or more, preferably 10.1% by mass or less, and more preferably 8.0% by mass or less, relative to the total amount of the coating liquid (the state before the silica precursor raw materials undergo hydrolysis and condensation). When the water content in the coating liquid is above the lower limit, hydrolysis can be carried out more reliably, and the matrix can be formed more reliably. Furthermore, when the water content in the coating liquid is below the upper limit, sparkling on the anti-glare surface of the uneven structure can be further suppressed.

[0042] Alcoholic beverages; Examples of alcohols include methanol, ethanol, 2-propanol, 1-butanol, and 2-butanol. These alcohols may be used individually or in combination. In particular, it is preferable to include 2-propanol as the solvent.

[0043] The alcohol content is preferably 30% by mass or more, more preferably 40% by mass or more, preferably 90% by mass or less, and more preferably 80% by mass or less, relative to the total amount of the coating solution (the state before the silica precursor raw materials undergo hydrolysis and condensation). In this case, the unevenness of the anti-glare treatment can be formed more efficiently.

[0044] Other solvents; The coating solution of the present invention may further contain other solvents, as long as they do not hinder the effects of the present invention.

[0045] Other solvents are not particularly limited, but examples include ketones, ethers, cellosolves, esters, glycol ethers, nitrogen-containing compounds, sulfur-containing compounds, and the like.

[0046] Examples of ketones include acetone, methyl ethyl ketone, and methyl isobutyl ketone.

[0047] Examples of ethers include tetrahydrofuran and 1,4-dioxane.

[0048] Examples of cellosolves include methyl cellosolve and ethyl cellosolve.

[0049] Examples of esters include methyl acetate and ethyl acetate.

[0050] Examples of glycol ethers include ethylene glycol monoalkyl ethers.

[0051] Examples of nitrogen-containing compounds include N,N-dimethylacetamide, N,N-dimethylformamide, and N-methylpyrrolidone.

[0052] Examples of sulfur-containing compounds include dimethyl sulfoxide.

[0053] These other solvents may be used individually or in combination.

[0054] The content of other solvents should preferably be 40% by mass or less relative to the total volume of the coating solution (the state before the silica precursor raw materials undergo hydrolysis and condensation).

[0055] (catalyst) The coating solution of the present invention may further contain an acid catalyst as a catalyst. As the acid catalyst, for example, a raw material for a silica precursor or a catalyst that promotes the hydrolysis and condensation reaction of a silica precursor can be used.

[0056] More specifically, examples of acid catalysts that can be used include inorganic acids (such as nitric acid, sulfuric acid, and hydrochloric acid) and organic acids (such as formic acid, oxalic acid, acetic acid, monochloroacetic acid, dichloroacetic acid, and trichloroacetic acid).

[0057] The pH of the coating solution is preferably 1 or higher, more preferably 2 or higher, even more preferably 3 or higher, preferably 7 or lower, more preferably 6 or lower, and even more preferably 5 or lower. When the pH of the coating solution is above the lower limit, damage to coating equipment such as spray nozzles can be further reduced. Furthermore, when the pH of the coating solution is below the upper limit, a denser and harder anti-glare layer can be formed.

[0058] Furthermore, the coating solution of the present invention may contain a base catalyst as a catalyst. In addition, the coating solution of the present invention may contain additives other than those mentioned above, as long as they do not hinder the effects of the present invention.

[0059] (Solid content) The coating liquid of the present invention preferably contains 1% by mass or more, more preferably 2% by mass or more, even more preferably 2.5% by mass or more, preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 4% by mass or less of solid content (heating residue). When the solid content (heating residue) is above the lower limit, the unevenness of the anti-glare layer can be formed more efficiently. Furthermore, when the solid content (heating residue) is below the upper limit, sparkling on the anti-glare surface of the uneven structure can be further suppressed.

[0060] [Method for manufacturing spray coating liquid] The following describes an example of a method for producing the coating solution of the present invention.

[0061] First, the silica precursor raw materials, a solvent, and, if necessary, an acid catalyst or base catalyst are mixed to obtain a mixture.

[0062] In the present invention, it is preferable that the above-mentioned mixture substantially does not contain oxide fine particles different from the raw materials of the silica precursor. In this case, the coating solution can be made easier to prepare, and the generation of sparkles due to aggregation of oxide fine particles can be further suppressed. Furthermore, when an anti-glare layer is formed on the substrate by the spray coating method, the adhesion and hardness between the substrate and the anti-glare layer can be further improved, and the occurrence of appearance defects due to aggregates of oxide fine particles can be prevented. It is desirable that the oxide fine particles are components different from the matrix-forming components.

[0063] Furthermore, oxide fine particles refer to fine particles whose average particle diameter of primary particles, as observed and measured by a transmission electron microscope, is 300 nm or less. The average particle diameter of oxide fine particles is preferably 4 nm or more, more preferably 6 nm or more, preferably 200 nm or less, and more preferably 100 nm or less.

[0064] Furthermore, "substantially free of oxide particles" means that the oxide particle content is less than 0.05% by mass of the total amount of coating solution (the state before the silica precursor raw materials undergo hydrolysis and condensation).

[0065] When oxide fine particles are included, the content of oxide fine particles is preferably 0.5% by mass or less, and more preferably 0.1% by mass or less, relative to the total amount of the coating solution (the state before the silica precursor raw materials undergo hydrolysis condensation).

[0066] The oxide fine particles are not particularly limited, and for example, silica, titania, zirconia, antimony oxide, alumina, indium oxide, or mixtures thereof can be used.

[0067] In the present invention, the content of components having a boiling point above 100°C and below 120°C is preferably 0% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, preferably 15% by mass or less, more preferably 10% by mass or less, and even more preferably 8% by mass or less, relative to the total amount of the coating liquid (the state before the silica precursor raw materials undergo hydrolysis condensation). When the content of components having a boiling point above 100°C and below 120°C is above the lower limit, the increase in haze can be further suppressed when an anti-glare layer is formed by the spray coating method. Furthermore, when the content of components having a boiling point above 100°C and below 120°C is below the upper limit, sparkle on the uneven anti-glare surface can be further suppressed.

[0068] Examples of components with a boiling point between 100°C and 120°C include isobutyl alcohol and 1-butanol.

[0069] In the present invention, the content of solvent components with a boiling point of 120°C or higher is preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 2% by mass or less, relative to the total amount of the coating solution (the state before the silica precursor raw materials undergo hydrolysis condensation). When the content of solvent components with a boiling point of 120°C or higher is below the above upper limit, the surface irregularities of the anti-glare layer can be formed more efficiently even without the presence of oxide fine particles. Furthermore, the solvent contained in the coating solution may not contain any components with a boiling point of 120°C or higher at all.

[0070] Examples of components with a boiling point of 120°C or higher include diacetone alcohol, 3-methoxybutyl acetate, 1-methyl-2-pyrrolidone, methyl cellosolve, and ethyl cellosolve.

[0071] Next, the resulting mixture is stirred and allowed to stand to mature. This allows hydrolysis and condensation reactions to proceed, yielding a coating solution. In this case, the standing time is the maturation time, and the standing temperature is the maturation temperature. Alternatively, stirring may be continued instead of standing. In this case, the stirring time is the maturation time, and the stirring temperature is the maturation temperature. The concentration of the matrix-forming component can be, for example, 2% to 20% by mass as solid content (heating residue).

[0072] In the method for producing the coating solution of the present invention, the coating solution is prepared such that the molecular size of the silica precursor is 5.6 nm or larger, based on the average value of the scattered light intensity measured by dynamic light scattering. Therefore, when an anti-glare layer is formed using the obtained coating solution by a spray coating method, sparkling on the anti-glare surface can be suppressed.

[0073] In the present invention, the molecular size of the silica precursor measured by dynamic light scattering can be adjusted by the degree of maturation of the mixture in the above manufacturing method. Specifically, the longer the maturation time, the larger the molecular size of the silica precursor can be. Therefore, it is preferable to monitor the molecular size of the silica precursor while maturing the mixture.

[0074] The maturation time can be, for example, 1 to 480 hours, and preferably 2 to 6 hours. The maturation temperature is preferably 15°C or higher, more preferably 18°C ​​or higher. When the maturation temperature is above the lower limit, the molecular size of the silica precursor can be increased in an even shorter time. The upper limit of the maturation temperature is not particularly limited, but for example, it can be 60°C. Figure 1 shows the relationship between maturation time and the molecular size of the silica precursor when the maturation temperature is 20°C and 45°C. It can be seen that the higher the maturation temperature, the shorter the maturation time required to increase the molecular size of the silica precursor.

[0075] The resulting coating solution may be further diluted by adding a solvent such as alcohol, as needed, to a ratio of approximately 1.2 to 10 times before use. Specifically, when preparing the above mixture, the amount of alcohol may be mixed at a ratio of approximately 1 / 30 to 1 / 3 of the final alcohol content, and the remainder may be added after maturation. In this case, the molecular size of the silica precursor can be increased in an even shorter time. Figure 2 shows the relationship between maturation time and the molecular size of the silica precursor at various alcohol amounts during maturation of the coating solution. Note that the mass ratio of tetraethoxysilane (TEOS), water (H2O), and alcohol during the preparation of the coating solution is as shown in Figure 2. From Figure 2, it can be seen that reducing the amount of alcohol during maturation allows for an increase in the molecular size of the silica precursor in a shorter time.

[0076] [Method for manufacturing a substrate with an anti-glare layer] A method for manufacturing a substrate with an anti-glare layer according to one embodiment of the present invention will be described below with reference to Figures 3(a) and (b).

[0077] As an example of a method for manufacturing a substrate with an anti-glare layer, first, prepare the substrate 2 shown in Figure 3(a).

[0078] Examples of materials for the base material 2 include transparent materials such as glass, ceramics, glass ceramics, and resins. Examples of glass include soda-lime glass, borosilicate glass, aluminosilicate glass, and alkali-free glass. In this case, the base material 2 may be subjected to strengthening treatments such as air-cooled strengthening or chemical strengthening. Examples of ceramics include sapphire. Examples of resins include polyethylene terephthalate, polycarbonate, triacetylcellulose, and polymethyl methacrylate.

[0079] The shape of the base material 2 is not particularly limited and may include a plate, a film, etc. Furthermore, the base material 2 may have a curved shape to match the shape of the display.

[0080] Furthermore, the substrate 2 may have a functional layer on the surface of the substrate body. Examples of functional layers include an undercoat layer, an adhesion-improving layer, a protective layer, and a coloring layer.

[0081] On the other hand, the coating solution is prepared according to the method for manufacturing the coating solution described above.

[0082] Next, the prepared coating solution is applied to the substrate 2 and allowed to dry. This forms the anti-glare layer 1 shown in Figure 3(b), and an anti-glare layered substrate 10 can be obtained.

[0083] When applying the coating liquid, it is preferable to spray the coating liquid onto the substrate 2 using the spray coating method. While two-fluid nozzles and one-fluid nozzles can be used for the spray coating method, a two-fluid spray gun using a two-fluid nozzle is preferred. In this case, the surface texture of the anti-glare layer can be formed more efficiently even without the presence of oxide particles. Furthermore, when the anti-glare layer is formed on the substrate using the spray coating method, the adhesion between the substrate and the anti-glare layer can be further improved.

[0084] The droplet size of the coating liquid discharged from the nozzle is typically 0.1 μm to 100 μm, preferably 1 μm to 50 μm. When the droplet size is above the lower limit, the surface irregularities that provide sufficient anti-glare effect can be formed in a shorter time. When the droplet size is below the upper limit, it becomes easier to form moderately sized irregularities that provide sufficient anti-glare effect. The droplet size of the coating liquid can be adjusted as appropriate depending on the type of nozzle, air flow rate, liquid volume, etc. For example, in a two-fluid nozzle, the droplet size decreases as the air flow rate increases, and the droplet size increases as the liquid volume increases. The droplet size refers to the median diameter on a volume basis measured by a laser diffraction particle size analyzer. The air flow rate can be, for example, 50 L / min to 300 L / min.

[0085] The spray distance can be, for example, 20 mm or more and 300 mm or less. The spray distance refers to the distance from the nozzle to the surface of the substrate 2 to be coated.

[0086] The amount of coating solution to be applied is, for example, 1 mL / m². 2 More than 300mL / m 2 The following is possible:

[0087] The application temperature of the coating solution can be, for example, 10°C or higher and 80°C or lower.

[0088] Furthermore, the surface temperature of the substrate 2 when applying the coating liquid is preferably, for example, 15°C to 75°C. Also, the humidity when applying the coating liquid is preferably, for example, 20% to 80%, and preferably 50% or higher.

[0089] The drying temperature of the coating solution can be, for example, between 100°C and 600°C. The drying time can be, for example, between 10 minutes and 600 minutes.

[0090] Furthermore, after the formation of the anti-glare layer 1, an anti-reflective layer or an anti-fouling layer may be provided on top of the anti-glare layer 1.

[0091] In the method for manufacturing the substrate 10 with an anti-glare layer according to this embodiment, a spray coating liquid is used in which the molecular size of the silica precursor is 5.6 nm or larger on average, based on the scattered light intensity measured by dynamic light scattering. This makes it possible to suppress sparkling on the anti-glare surface. Since sparkling on the anti-glare surface can be suppressed, visibility can be improved when used in displays and the like.

[0092] Therefore, the substrate with an anti-glare layer obtained by the manufacturing method of the present invention can be suitably used in displays such as mobile phones, tablet devices, televisions, or digital signage.

[0093] The present invention will be described in more detail below based on specific examples. The present invention is not limited in any way to the following examples, and can be implemented with appropriate modifications without changing its essence.

[0094] (Example 1) A coating solution was obtained by mixing and aging tetraethoxysilane (TEOS, manufactured by Tokyo Chemical Industry Co., Ltd., product number "T0100") as a silicate monomer, water, alcohol (a mixture of ethanol, methanol, and isopropyl alcohol, manufactured by Daishin Chemical Co., Ltd., product number "Neoethanol IPM"), and nitric acid in a ratio of TEOS:water:alcohol = 1.0:0.6:7.8 (mass ratio) to obtain a coating solution with an average molecular size of 5.6 nm based on scattered light intensity measured by dynamic light scattering. The nitric acid was adjusted to a pH of 4 before mixing. The above raw materials were substantially free of oxide fine particles when mixed.

[0095] Furthermore, when the heating residue in the obtained coating solution was measured, it was found to be 3.0% by mass in Example 1.

[0096] Next, the obtained coating solution was spray-coated onto a reinforced glass substrate (manufactured by Nippon Electric Glass Co., Ltd., T2X-1) to form an anti-glare layer, thereby obtaining a substrate with an anti-glare layer. The coating amount during spray coating was 20 mL / m². 2 The following was done: A two-fluid spray gun was used, with a spray travel speed (nozzle travel speed) of 45 m / min and a spray distance of 60 mm. The air flow rate was set to 120 L / min.

[0097] (Example 2) In Example 2, a coating solution and a substrate with an anti-glare layer were obtained in the same manner as in Example 1, except that the average molecular size based on scattered light intensity in dynamic light scattering measurements was adjusted to 7.1 nm.

[0098] (Example 3) In Example 3, a coating solution and a substrate with an anti-glare layer were obtained in the same manner as in Example 1, except that the average molecular size based on scattered light intensity in dynamic light scattering measurements was adjusted to 7.2 nm.

[0099] (Example 4) In Example 4, a coating solution and a substrate with an anti-glare layer were obtained in the same manner as in Example 1, except that the average molecular size based on scattered light intensity in dynamic light scattering measurements was adjusted to 8.0 nm.

[0100] (Example 5) In Example 5, TEOS:water:alcohol was mixed and aged in a ratio (mass ratio) of 1.0:0.9:7.0 to obtain a coating solution with an average molecular size of 7.1 nm based on scattered light intensity measured by dynamic light scattering. The coating solution and the substrate with an anti-glare layer were obtained in the same manner as in Example 1.

[0101] (Example 6) In Example 6, a coating solution and a substrate with an anti-glare layer were obtained in the same manner as in Example 5, except that the average molecular size based on scattered light intensity in dynamic light scattering measurement was adjusted to 8.9 nm.

[0102] (Example 7) In Example 7, a coating solution and a substrate with an anti-glare layer were obtained in the same manner as in Example 5, except that the average molecular size based on scattered light intensity in dynamic light scattering measurements was adjusted to 11.0 nm.

[0103] (Example 8) In Example 8, instead of TEOS as the silicate monomer, an oligomer of tetramethoxysilane (TMOS) (average tetramer, Colcoat, "Methyl Silicate 51") was used as the silicate oligomer. Furthermore, a coating solution was obtained by mixing and aging TMOS:water:alcohol in a ratio (mass ratio) of 1.0:1.1:13.7, with an average molecular size of 18.1 nm based on scattered light intensity measured by dynamic light scattering. The coating solution and the substrate with the anti-glare layer were obtained in the same manner as in Example 1.

[0104] (Example 9) In Example 9, TEOS:water:alcohol was mixed and aged in a ratio (mass ratio) of 1.0:1.2:5.9 to obtain a coating solution with an average molecular size of 8.4 nm based on scattered light intensity measured by dynamic light scattering. The coating solution and the substrate with an anti-glare layer were obtained in the same manner as in Example 1.

[0105] (Example 10) In Example 10, TEOS:water:alcohol was mixed and aged in a ratio (mass ratio) of 1.0:0.26:8.5 to obtain a coating solution with an average molecular size of 8.9 nm based on scattered light intensity measured by dynamic light scattering. The coating solution and the substrate with an anti-glare layer were obtained in the same manner as in Example 1.

[0106] (Example 11) In Example 11, TEOS:water:alcohol was mixed and aged in a ratio (mass ratio) of 1.0:0.6:5.2 to obtain a coating solution with an average molecular size of 8.4 nm based on scattered light intensity measured by dynamic light scattering. The coating solution and the substrate with an anti-glare layer were obtained in the same manner as in Example 1.

[0107] (Comparative Example 1) In Comparative Example 1, the coating solution and the substrate with the anti-glare layer were obtained in the same manner as in Example 1, except that the maturation time when preparing the coating solution was shortened compared to Example 1, and the average molecular size based on scattered light intensity in dynamic light scattering measurement was adjusted to 3.1 nm.

[0108] (Example 12) In Example 12, instead of a mixture of ethanol, methanol, and isopropyl alcohol, isopropyl alcohol (manufactured by Tokuyama Corporation, product number "Tokuso IPA") was used as the alcohol. Furthermore, the mixture was prepared by mixing and aging TEOS:water:alcohol in a ratio (mass ratio) of 1.0:0.79:7.7 to obtain a coating solution with an average molecular size of 6.3 nm based on scattered light intensity measured by dynamic light scattering. Nitric acid was added after adjusting the pH to 3.5. For spray coating, the application rate was 50 mL / m².2 The spray movement speed (nozzle movement speed) was set to 20 m / min, the spray distance to 100 mm, and the air flow rate to 141 L / min. The coating liquid and the substrate with anti-glare layer were obtained in the same manner as in Example 1.

[0109] (Example 13) In Example 13, instead of TEOS as the silicate monomer, an oligomer of TEOS (average 10-mer, manufactured by Colcoat Co., Ltd., "Ethyl Silicate 48") was used as the silicate oligomer. The TEOS oligomer, water, and alcohol were mixed and aged in a ratio (mass ratio) of 1.0:0.9:12.7 to obtain a coating solution with an average molecular size of 7.0 nm based on scattered light intensity measured by dynamic light scattering. Nitric acid was added to adjust the pH to 4.0. For spray coating, the application rate was 61 mL / m². 2 The spray movement speed (nozzle movement speed) was set to 17 m / min, the spray distance to 58 mm, and the air flow rate to 79 L / min. The coating liquid and the substrate with anti-glare layer were obtained in the same manner as in Example 12.

[0110] (Example 14) In Example 14, 1-butanol (manufactured by Nacalai Tesque Co., Ltd.) was further added as another alcohol, and the mixture was mixed and aged in a ratio (mass ratio) of TEOS oligomer:water:alcohol:1-butanol = 1.0:0.9:12.7:0.6 to obtain a coating solution with an average molecular size of 7.1 nm based on scattered light intensity in dynamic light scattering measurement. The coating solution and the substrate with an anti-glare layer were obtained in the same manner as in Example 13.

[0111] (Example 15) In Example 15, TEOS oligomer:water:alcohol:1-butanol was mixed and aged in a ratio (mass ratio) of 1.0:0.9:12.7:0.9 to obtain a coating solution with an average molecular size of 6.9 nm based on scattered light intensity measured by dynamic light scattering. The coating solution and the substrate with an anti-glare layer were obtained in the same manner as in Example 14.

[0112] (Example 16) In Example 16, TEOS oligomer:water:alcohol:1-butanol was mixed and aged in a ratio (mass ratio) of 1.0:0.9:12.7:1.2 to obtain a coating solution with an average molecular size of 7.1 nm based on scattered light intensity measured by dynamic light scattering. The coating solution and the substrate with an anti-glare layer were obtained in the same manner as in Example 14.

[0113] (Example 17) In Example 17, TEOS oligomer:water:alcohol:1-butanol was mixed and aged in a ratio (mass ratio) of 1.0:0.9:12.7:1.5 to obtain a coating solution with an average molecular size of 6.9 nm based on scattered light intensity measured by dynamic light scattering. The coating solution and the substrate with an anti-glare layer were obtained in the same manner as in Example 14.

[0114] (Example 18) In Example 18, TEOS oligomer:water:alcohol:1-butanol was mixed and aged in a ratio (mass ratio) of 1.0:0.9:12.7:2.0 to obtain a coating solution with an average molecular size of 6.9 nm based on scattered light intensity measured by dynamic light scattering. The coating solution and the substrate with an anti-glare layer were obtained in the same manner as in Example 14.

[0115] (Comparative Example 2) In Comparative Example 2, the coating solution and the substrate with the anti-glare layer were obtained in the same manner as in Example 12, except that the amount of alcohol used during the maturation of the coating solution was increased compared to Example 12, and the average molecular size based on scattered light intensity in dynamic light scattering measurement was adjusted to 3.0 nm.

[0116] (Reference example 1) Ethyl silicate 48 (manufactured by Colcoat), an ethyl silicate oligomer with an average of 10-mers, was diluted with IPA, and without undergoing hydrolysis condensation, the average molecular size based on scattered light intensity in dynamic light scattering measurements was measured to be 2.9 nm.

[0117] [evaluation] (Evaluation using dynamic light scattering method) The scattered light intensity of the coating solutions obtained in Examples 1-18, Comparative Examples 1 and 2, and Reference Example 1 was measured by dynamic light scattering. The measurement device used was a Malvern Panalytical "Zetasizer Nano S" (model number). The molecular size of the silica precursor was determined from the average value of the scattered light intensity measured by dynamic light scattering. The measurement was performed at a fixed position where the average scattering intensity was 500 kcps, with an execution time of 3 seconds and 30 executions. The average was calculated over 45 measurements, and the particle size distribution was calculated using the non-negative least squares method to obtain the average value of the scattered light intensity. For other parameters, the measurement temperature was 20.0°C, the number of size classes was 70, the particle size distribution lower limit was 0.4, the display upper limit was 10000, the lower threshold was 0.05, the upper threshold was 0.01, the resolution was standard, the display range lower limit was 0.6, and the display range upper limit was 300.

[0118] (Evaluation of anti-glare properties) For the substrates with anti-glare layers obtained in Examples 1-18 and Comparative Examples 1 and 2, gloss (an indicator of glossiness), haze (an indicator of opacity), and sparkle (an indicator of glare) were measured. Gloss was measured at an incident angle of 60° on the substrates with anti-glare layers, according to JIS Z 8741:1997, using Microgloss(60°) (manufactured by BYK). Haze was measured using NDH-5000 (manufactured by Nippon Denshoku Co., Ltd.), according to JIS K 7136:2000. Sparkle was measured using SMS-1000 (manufactured by Display-Messtechnik&Systeme) in sparkle measurement mode.

[0119] (hardness) The hardness of the anti-glare coated substrates obtained in Examples 1 to 18 and Comparative Examples 1 and 2 was determined by measuring pencil hardness in accordance with JIS K 5600-5-4:1999.

[0120] The results are shown in Tables 1 and 2 below.

[0121] [Table 1]

[0122] [Table 2]

[0123] In Examples 1-11 and Comparative Example 1, where the gloss was high at 123%-144%, Tables 1 and 2 show that in Examples 1-11, where the silica precursor molecular size was 5.6 nm or larger based on the average scattered light intensity measured by dynamic light scattering, sparkle was suppressed compared to Comparative Example 1, where the silica precursor molecular size was 3.1 nm based on the average scattered light intensity measured by dynamic light scattering. Furthermore, in Examples 12-18 and Comparative Example 2, where the gloss was low at 25%-72%, Tables 1 and 2 show that in Examples 12-18, where the silica precursor molecular size was 6.3 nm or larger based on the average scattered light intensity measured by dynamic light scattering, sparkle was suppressed compared to Comparative Example 2, where the silica precursor molecular size was 3.0 nm based on the average scattered light intensity measured by dynamic light scattering. [Explanation of symbols]

[0124] 1…Anti-glare layer 2...Base material 10…Substrate with anti-glare layer

Claims

1. A coating solution for spray coating, comprising a silica precursor and a solvent, A coating liquid for spray coating, wherein the molecular size of the silica precursor is 5.6 nm or more and 8.9 nm or less on average, based on the scattered light intensity measured by dynamic light scattering, and substantially does not contain oxide fine particles, which are components different from the silica precursor.

2. A method for producing a spray coating liquid according to claim 1, A step of preparing a mixed solution containing the raw materials for the silica precursor and a solvent, The process involves maturing the prepared mixture, A method for manufacturing a coating liquid for spray coating, comprising the following features.

3. The method for producing a coating liquid for spray coating according to claim 2, wherein the raw material for the silica precursor is a monomer or oligomer of alkoxysilane.

4. The method for producing a coating liquid for spray coating according to claim 3, wherein the alkoxysilane is tetramethoxysilane or tetraethoxysilane.

5. A method for producing a spray coating liquid according to any one of claims 2 to 4, wherein the content of a solvent component having a boiling point of 120°C or higher in the mixed liquid is 5% by mass or less.

6. A step of preparing a spray coating liquid by a method for manufacturing a spray coating liquid according to any one of claims 2 to 5, The process involves applying the spray coating liquid to a substrate to form an anti-glare layer, A method for manufacturing a substrate with an anti-glare layer, comprising the following:

7. A method for manufacturing a substrate with an anti-glare layer according to claim 6, wherein the coating liquid for spray coating is applied using a two-fluid spray gun.

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