JP5157143B2 - Base with antireflection film - Google Patents

Description

  The present invention relates to a substrate with an antireflection film, for example, a laminated glass for automobile windows having an antireflection film on the surface and having a low visible light reflectance.

An antireflection film can be formed on the surface of a transparent substrate such as glass to impart antireflection ability. For example, in a laminated glass plate used for an automobile window, an antireflection film may be formed on the surface in order to prevent visible light from being reflected on the surface and thereby reducing transmittance and light transmittance. Specifically, in an automobile windshield, light from the instrument panel (instrument panel), dashboard, etc. in the vehicle is reflected by the surface of the windshield, and the reflected image of the instrument panel, dashboard enters the driver's view. For this reason, there is a problem that visibility in front of the driver is lowered.
In addition, in the side window glass and rear glass of automobiles, the reflected light from instrument panels and dashboards in the car and the light from interior lights, light-emitting display panels, and illumination lights of audio devices are reflected on the surface of the side window glass and rear glass. In addition, since it enters the driver's field of view directly or through the interior reflector and causes reflection, the visibility of the driver's side and rear is reduced.
Further, the reflected light from the side window glass and rear glass is further reflected on the windshield directly or after being reflected on the vehicle interior parts, so that there is a problem that the front visibility is lowered.

As a transparent substrate on which an antireflection film is formed, for example, those described in Patent Documents 1 to 3 have been proposed.
Patent Documents 1 to 3 describe glass plates with an antireflection film for automobile windows and the like, which are made of chain silica fine particles and silica and have a film having a specific thickness. And since such a glass plate with an antireflection film is prevented from being reflected, it is described that it is suitable for an automobile window.
JP 11-292568 A JP 2000-256040 A JP 2001-278737 A

However, such an antireflection film has a problem of poor antifouling properties.
Therefore, the present invention provides the performance required for an antireflection film, that is, high antireflection performance, a relatively constant reflectance in the visible light region, relatively easy production, low production cost, and antifouling properties. An object of the present invention is to provide a transparent substrate with an antireflection film that is excellent in the above.

The present invention includes the following (1) to (5).
(1) A substrate with an antireflection film having an antireflection film on the surface of a transparent substrate, the antireflection film containing hollow silica particles, and a total pore volume of 1.0 × 10 ⁻³ mL / g or less The transparent substrate is a glass plate, the antireflection film is mainly composed of the hollow silica particles and a matrix component, and at least a part of the matrix component is a metal oxide, and has a temperature of 500 to 700 ° C. A substrate with an antireflection film, which is obtained by holding under temperature conditions.
(2) The substrate with an antireflection film according to the above (1), wherein the hollow silica has an average aggregate particle diameter of 10 to 1000 nm .
(3) The antireflection according to (1) or (2), wherein the hollow silica is produced by removing a core of core-shell type fine particles, and the core fine particles constituting the core are zinc oxide. Substrate with film.
(4) The substrate with an antireflection film according to any one of (1) to (3), wherein the antireflection film has a thickness of 60 to 700 nm.
(5) a first transparent substrate, a second transparent substrate provided with an antireflection film, and an intermediate film interposed between the first transparent substrate and the second transparent substrate, The laminated glass for vehicle windows in which the transparent substrate is disposed on the vehicle interior, wherein the second transparent substrate having an antireflection film is the substrate with an antireflection film as described in any one of (1) to (4) above Laminated glass for vehicle windows.

  According to the present invention, a transparent substrate with an antireflection film having a high antireflection ability, a relatively constant reflectance in the visible light region, a relatively easy production, a low production cost, and an excellent antifouling property is provided. Can be provided. And such a transparent base | substrate with an antireflection film can be preferably used as glass for motor vehicle windows.

The substrate with an antireflection film of the present invention is a substrate with an antireflection film having an antireflection film on the surface of a transparent substrate. The antireflection film includes hollow silica particles. Further, the antireflection film has a total pore volume of 1.0 × 10 ⁻³ mL / g or less.

  In the substrate with an antireflection film of the present invention, the antireflection film contains hollow silica particles and a matrix component (binder component), and these are preferably the main components. In the antireflection film, the hollow silica particles are present inside or on the surface of the antireflection film. Even when a part of the hollow silica particles is contained in the antireflection film and a part is exposed on the surface of the antireflection film, it is within the scope of the present invention.

Here, the hollow silica particles are hollow particles having SiO ₂ as a main component and having voids inside the outer shell. A state where a part of the void is exposed to the outside of the outer shell of the particle, that is, a state where the void inside the hollow silica particle is connected to the outside of the hollow silica particle may be used.
The shape of the hollow silica particles is not particularly limited. Examples include spherical, oval, spindle, and amorphous. Such a shape is preferable because the antifouling property of the substrate with an antireflection film of the present invention is enhanced. The shape of the hollow silica particles may be a chain shape, needle shape, columnar shape, rod shape, flat shape, scale shape, leaf shape, tube shape, sheet shape, etc. It is preferably used in combination with a shape, a spindle shape, an amorphous shape, or the like.
Silica particles that are not hollow can also be used together with the hollow silica particles. The shape, size, etc., of the silica particles that are not hollow may be the same as those of the hollow silica particles. For example, hollow silica particles and non-hollow chain silica particles can be used.

The particle size of the hollow silica particles is not particularly limited, but is preferably 0.1 to 1000 nm in terms of average particle size, more preferably 2 to 500 nm, and more preferably 10 to 100 nm. More preferably, it is ˜70 nm. This is because the transparency of the antireflection film tends to increase. A narrow particle size distribution is preferred.
In the case of using non-hollow chain silica particles, the chain silica particles have an average diameter of 10 to 20 nm and an average length of 60 to 200 nm, are linear, and are three-dimensionally curved. The shape is not particularly limited. Examples of such chain silica particles include “Snowtex-OUT” and “Snowtex-UP” manufactured by Nissan Chemical Industries, Ltd.

  Further, the size of the voids inside the hollow silica particles is not particularly limited. The larger the value, the higher the antireflection performance of the antireflection film as a whole. However, if it is too large, the strength of the antireflection film may be reduced. Although this size depends on the particle size of the hollow silica particles, the thickness of the outer shell is preferably, for example, 0.01 to 100 nm, more preferably 0.5 to 50 nm, and 1 to 20 nm. More preferably, it is more preferably 5 to 10 nm. Further, the thickness is preferably about 1/50 to 1/5 of the particle size of the hollow silica particles, and more preferably about 1/5 to 1/3.

Further, the hollow silica particles may be aggregated in the antireflection film. For example, about 2 to 10 pieces may be aggregated. In this case, the strength and wear resistance of the antireflection film tend to increase. Moreover, it is preferable that the particle diameter (average aggregate particle diameter) as an aggregate is 10 to 1000 nm, more preferably 30 to 700 nm, more preferably 60 to 400 nm, and 100 to 200 nm. Is more preferable. Moreover, it is preferable that an average aggregated particle diameter is 1.5 times or more of the average particle diameter (average primary particle diameter) in the state which is not aggregated.
The average primary particle diameter is a value observed with a transmission electron microscope, and the average aggregate particle diameter is a value measured by a dynamic light scattering method.

  In the substrate with an antireflection film of the present invention, the antireflection film is preferably an antireflection film mainly composed of the hollow silica particles and the matrix component as described above. The main component means a content of 50% by mass or more. That is, the ratio of the total mass of the hollow silica particles and the matrix component to the total mass of the antireflection film is 50% by mass or more. This ratio is more preferably 70% by mass or more, more preferably 90% by mass or more, more preferably 95% by mass or more, and further preferably 98% by mass or more.

  Here, the matrix component may be any type as long as it can contain the hollow silica particles inside and can adhere to the surface of a transparent substrate described later to form an antireflection film. For example, an inorganic substance is mentioned and it is preferable that it is a metal oxide. Specific examples include silicon oxide, aluminum oxide, titanium oxide, zirconium oxide, tantalum oxide, and tin oxide. Two or more kinds of inorganic substances can be used in combination.

Moreover, it is preferable that such a matrix component is formed by converting a hydrolytic condensable compound into a metal oxide matrix component in a film forming process. As the hydrolytic condensable compound, a metal compound having a hydrolyzable group or a metal compound having a ligand is preferable. Among these, a hydrolytic condensable metal compound in which a hydrolyzable group such as an alkoxy group, an isocyanate group, an acyloxy group, an aminoxy group, or a halogen group is bonded to a metal atom of Si, Al, Ti, Zr, or Ta is more preferable. For example, silicon tetraalkoxide, aluminum trialkoxide, titanium tetraalkoxide and zirconium tetraalkoxide. More specifically, tetraethoxysilane, tetramethoxysilane, tetraisocyanatesilane, trimethoxyaluminum, titanium tetraisopropoxide, and zirconium tetraethoxide are exemplified.
The hydrolytic condensable metal compound in which a hydrolyzable group such as an alkoxy group is bonded to a metal atom such as Si may be a compound in which an organic group is bonded in addition to the hydrolyzable group. The number of organic groups is preferably 1 to 2. Examples of the organic group include an alkyl group, an alkenyl group, and an aryl group, and an alkyl group is preferable. Examples of such a compound include alkyl alkoxy silane and dialkyl alkoxy silane. More specifically, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, and dimethyldiethoxysilane are exemplified.

  The ratio of the hollow silica particles contained in the antireflection film is not particularly limited. It is preferable that it is 10-90 mass% with respect to the total mass (The hollow silica particle and other components are included, and a matrix component is the same also in the following in oxide conversion) of the said antireflection film. %, Preferably 40 to 80% by mass. This is because the antireflection effect tends to increase.

  The mass ratio of the hollow silica particles forming the antireflection film and the matrix component is preferably in the range of 50:50 to 95: 5, and more preferably 65:35 to 85:15. . This is because, within such a range, the antireflection effect tends to increase, and the adhesion between the antireflection film and the transparent substrate tends to increase.

  The substance constituting the antireflection film is preferably only the hollow silica particles and the matrix component, but may contain other components. Examples of other components include non-hollow silica particles (such as chain silica particles), ultraviolet absorbers, antioxidants, and pigments. Further, as long as the antireflection performance is not deteriorated, a residual component (ZnO or the like) of a core fine particle component described later may be included. Such other components are preferably 5% by mass or less based on the total mass of the antireflection film.

The thickness of the antireflection film may be set so that the optical film thickness is an integral multiple of λ / 4 (where λ is the wavelength of light). Therefore, for example, in order to reflect visible light of 380 to 780 nm, the optical film thickness of the antireflection film is an integral multiple of [95 to 195 nm]. The optical film thickness is represented by the product of the geometric film thickness and the refractive index of the film material. In consideration of the refractive index of the material (described later, about 1.2 to 1.4), the antireflection film The geometric thickness is an integral multiple of [67 to 163 nm].
However, when the geometric film thickness is large, there is a problem that productivity is low, and considering this problem, the geometric film thickness is preferably 60 to 700 nm, and preferably 70 to 300 nm. Is more preferable, it is more preferable that it is 80-200 nm, and it is more preferable that it is 90-150 nm.
Here, the geometric thickness of the antireflection film means an average thickness, and the cross section of the antireflection film is observed with a microscope or measured with a stylus type film thickness meter.
The thickness of the antireflection film of the substrate with the antireflection film of the present invention is preferably adjusted so that the reflectance at a wavelength of 600 to 630 nm takes a minimum value. Considering the mounting angle of the base with an antireflection film to the vehicle, it is more preferable that the reflectance in the visible light region can be particularly reduced by adjusting the reflectance at the wavelength to be a minimum value.

In the substrate with an antireflection film of the present invention, the antireflection film has a total pore volume of 1.0 × 10 ⁻³ mL / g or less and 8.0 × 10 ⁻⁴ mL / g or less. It is more preferable that it is 1.0 * 10 < ^-5 > -8.0 * 10 < ^-4 > mL / g. In such a range, the antireflection ability is high, the reflectance in the visible light region is relatively constant, and it can be manufactured relatively easily as described later, and the manufacturing cost is low, and the antireflection is excellent in antifouling property. Become a film.

  Here, the value of the total pore volume is a value obtained by adsorbing nitrogen gas to the antireflection film and determining the adsorption amount. For example, it is obtained by analyzing by a DFT method using a gas adsorption amount measuring device.

Such an antireflection film has a low refractive index. Specifically, it tends to be about 1.4 or less, preferably 1.2 to 1.4, and particularly preferably 1.25 to 1.35. For example, an antireflection film composed only of the hollow silica particles and the matrix component, wherein the hollow silica particles have a particle size of 40 to 50 nm (average primary particle size), the matrix component is SiO ₂ , and the hollow silica particles When the mass ratio of the matrix component is 8: 2 to 5: 5, the refractive index of the antireflection film is about 1.28 to 1.35.

In the substrate with an antireflection film of the present invention, the transparent substrate means a generally transparent object. An example is a glass object. Moreover, a glass plate is mentioned. A size, thickness, etc. are not specifically limited. The glass plate is not necessarily a plate having a horizontal plane, and may be curved, for example.
In addition, the transparency of the substrate with an antireflection film of the present invention is such that the haze value in the standard of JIS K-7150 is preferably 5% or less, more preferably 2% or less, and 1% or less. Is preferable, and it is further more preferable that it is 0.5% or less.

  The substrate with an antireflection film of the present invention is a substrate with an antireflection film having the antireflection film containing the hollow silica particles on at least a part of the surface of the transparent substrate. An antireflection film may be provided on one of the main surfaces of the transparent substrate, or may be provided on both surfaces.

The base with an antireflection film of the present invention as described above has a high antireflection ability, has a relatively constant reflectance in the visible light region, and is excellent in antifouling properties. Moreover, since it can manufacture by the method which is mentioned later, manufacturing cost is suppressed and it is preferable. Also, radio wave transmission tends to be high. Further, since it has a particularly high ability to prevent reflection of visible light and the reflectance in the visible light region tends to be a relatively constant value, it can be preferably used as glass for automobile windows. Specifically, the substrate with an antireflection film of the present invention preferably has a minimum reflectance of 4% or less in the visible light region having a wavelength of 380 to 780 nm, and the maximum and minimum reflectances. Is particularly preferably 3% or less (preferably 2% or less). When the minimum value of the reflectance is 4% or less, the function as a low refractive index film is sufficient. Further, it is more preferable that the difference between the maximum value and the minimum value of reflectance is 3% or less (preferably 2% or less) because the saturation is increased. This value is the reflectance of the pure film surface excluding back surface reflection. The reflectance is measured with a spectrophotometer.
The radio wave permeability is preferably such that the sheet resistance value is 100 MΩ / □ or more.

The manufacturing method of the base | substrate with an antireflection film of this invention is demonstrated.
The substrate with an antireflection film of the present invention can be produced by several methods. Three production methods are illustrated below. Each manufacturing method is referred to as manufacturing method A, manufacturing method B, and manufacturing method C.

<Production method A>
Manufacturing method A will be described.
First, hollow silica particles are produced. Hollow silica particles can be produced by removing the core of core-shell type fine particles whose outer shell is SiO ₂ .
First, the core in the presence of core fine particles constituting the core in the dispersion medium, with SiO ₂ which is reacted with the precursor SiO ₂ and pH as above about 8 to produce a SiO _2, was produced constituting the particle shell A step of obtaining a dispersion of fine particles coated with the fine particles is performed.

  Examples of the core fine particles include those that dissolve, decompose, or sublime by heat, acid, or light. For example, thermally decomposable organic polymer fine particles such as surfactant micelles, water-soluble organic polymers, styrene resins and acrylic resins; acid-soluble inorganic fine particles such as sodium aluminate, calcium carbonate, basic zinc carbonate and zinc oxide; One or a mixture of two or more selected from metal chalcogenide semiconductors such as zinc sulfide and cadmium sulfide and light-soluble inorganic fine particles such as zinc oxide can be used. Among these, zinc oxide is preferable. The reason is that workability and productivity when removing the core are very good; rapid aggregation of the hollow silica fine particles is suppressed during the removal of the core, so that a highly transparent antireflection film can be obtained; It is.

The method for forming the core fine particles is not particularly limited. For example, it may be synthesized by either a dry method such as a gas phase method or a wet method such as a liquid phase method, and may be a monodisperse or an aggregate.
The size and shape of the core fine particles are not particularly limited. For example, one or a mixture of two or more selected from a spherical shape, a spindle shape, a rod shape, an amorphous shape, a columnar shape, a needle shape, a flat shape, a scale shape, a leaf shape, a tube shape, and a sheet shape can be used. The core fine particles may be aggregated.
The average primary particle size of the core fine particles (particle size in a non-aggregated state) is selected from the viewpoint of adjusting the dissolution rate of the core in the subsequent core fine particle dissolution step and the size of the voids of the resulting hollow silica particles it can. For example, it can be 5 to 400 nm, preferably 50 to 350 nm, and more preferably 50 to 200 nm.

  The dispersion medium for the core fine particles is not particularly limited. Examples thereof include water, alcohols, ketones, esters, ethers, nitrogen-containing compounds, and sulfur-containing compounds.

As a dispersion medium for the core fine particles, it is not essential to contain water, but considering that it is used as it is when the subsequent SiO ₂ precursor is hydrolyzed and polycondensed, the preferred dispersion medium is water alone or It is a mixed solvent of water and the above organic solvent.

  The core fine particle dispersion comprises a dispersion medium such as the above water, alcohols, ketones, esters, ethers, glycol ethers, nitrogen-containing compounds, sulfur-containing compounds, and preferably a dispersant. And then peptized by a dispersing machine such as a ball mill, a bead mill, a sand mill, a homomixer, or a paint shaker.

  The solid content concentration of the core fine particle dispersion is preferably 50% by mass or less and 0.1% by mass or more, and more preferably 30% by mass or less and 1% by mass or more in order to ensure the stability of the dispersion.

The hollow silica particle dispersion is prepared by reacting the precursor of SiO _{2 at} a pH of about 8 or more by adding a hydrolysis catalyst such as acid or alkali in the presence of core fine particles dispersed in a dispersion medium. The SiO ₂ precursor can be hydrolyzed and deposited around the core fine particles (outer surface) to form an outer shell. The pH of the dispersion during mixing of the SiO ₂ precursor is preferably 9-11. This is because the SiO ₂ outer shell can be formed in a short time, and the generated SiO ₂ itself hardly aggregates.

In addition, an electrolyte such as magnesium hydroxide may be added in order to increase the ionic strength and facilitate the formation of the shell from the SiO ₂ precursor when producing the core-shell type fine particle dispersion. Can be used to adjust the pH.

The temperature at the time of forming the outer shell of SiO ₂ can be set to 20 to 100 ° C.

Examples of the SiO ₂ precursor include one or a mixture of two or more selected from silicic acid, silicate, and silicate silicate, and may be a hydrolyzate or polymer thereof.

  The solid content concentration in producing the core-shell type fine particle dispersion is not particularly limited. The range is preferably 30% by mass or less and 0.1% by mass or more, and more preferably 20% by mass or less and 1% by mass or more. When the content is 30% by mass or less, the stability of the fine particle dispersion tends to increase. When the content is 0.1% by mass or more, the productivity of the hollow silica particles tends to increase.

  Next, a step of obtaining a hollow silica particle dispersion by dissolving the core particles in the core-shell type particle dispersion is performed.

The core fine particles dissolve as ions when the pH is low (for example, about 8 or less). For example, when the core fine particles are ZnO fine particles, they are dissolved as Zn ²⁺ ions. The dissolution of the core fine particles can be performed by adding an acid or by using an acidic cation exchange resin. When the acidic cation exchange resin is used, since the core fine particles are gradually dissolved, it is possible to prevent the ion concentration in the solution from rapidly increasing, and it is possible to suppress the rapid aggregation of the hollow silica particles. When rapid aggregation occurs, the aggregate particle diameter becomes too large, and the transparency of the film may be impaired.
As the acidic cation exchange resin, a resin in which at least the core fine particles are dissolved and the pH of the dispersion is 8 or less, preferably 6 or less is preferable. Here, the acidity of the acidic cation exchange resin is determined by the functional group, and in the present invention, there is -SO ₃ H group in the strong acid, and -COOH group in the weak acid, but in the present invention, the strong acid having a higher ability to dissolve the core fine particles. It is preferable to use a cationic cation exchange resin. For example, a sulfonic acid type strongly acidic ion exchange resin can be used.

The amount of the acidic cation exchange resin to be added is preferably in a range where the total exchange capacity is larger than at least the amount of ions such as Zn ²⁺ generated. The resin amount is preferably in the range of 1.1 to 5 times the required amount. As the amount of the acidic cation exchange resin increases, the dissolution rate of the core fine particles tends to increase.

  The larger the surface area of the cation exchange resin, the larger the contact area with the ions, so that the dissolution rate of ZnO, which is the core fine particle, is faster. Regarding the particle size, the smaller the particle size of the cation exchange resin, the larger the surface area and the larger the contact area with the ions, so the dissolution rate of the core fine particles increases, so use a 10-50 mesh cation exchange resin. Is preferred.

The temperature condition for dissolving the core fine particles is not particularly limited. Even at room temperature, the dissolution reaction basically proceeds.
A higher temperature is preferable because the dissolution rate of the core fine particles increases because the diffusion rate of dissolution reaction and dissolved ions increases. It can be set to 10 to 100 ° C., and preferably about 20 to 80 ° C.
The confirmation that the core fine particles are completely removed can be performed by observation with a transmission electron microscope or by measuring the amount of Zn or the like in the fine particle dispersion by fluorescent X-rays. However, in the present invention, it is not necessarily completely removed.

Next, after the core fine particles are dissolved (preferably completely), the cation exchange resin is separated by a solid-liquid separation operation such as filtration to obtain a hollow silica particle dispersion.
As the solid-liquid separation operation, only the cation exchange resin particles are separated, and the hollow silica particles that are fine particles can be separated from the cation exchange resin particles while being dispersed in the liquid. Any chemical engineering unit operation can be used. For example, it can be easily separated by sedimentation and filtration operations.

  A dispersion containing hollow silica particles can be obtained by such a method.

  In order to produce the substrate with an antireflection film of the present invention, a matrix component (binder) mainly composed of an inorganic substance or the like is mixed in the liquid in which the hollow silica particles are dispersed. The solid component equivalent of the matrix component to be mixed is preferably in the range of 0.1 to 10 times the mass of the hollow silica particles in the hollow silica particle dispersion. This is because the hardness of the antireflection film formed and the antireflection ability tend to increase when the thickness is within such a range.

  As said matrix component, the precursor of a metal oxide is mentioned, for example, Another substance, for example, organic resin, may be included.

Examples of the metal oxide include one or a mixture of two or more selected from Al ₂ O ₃ , SiO ₂ , SnO ₂ , TiO ₂ , and ZrO ₂ , and the precursor thereof includes a metal alkoxide and / or the metal. Examples thereof include hydrolyzed polycondensates. Moreover, as an organic resin, an ultraviolet curable organic resin is mentioned as a preferable thing. Specific examples include one or a mixture of two or more selected from acrylic resins, urethane acrylate resins, epoxy acrylate resins, polyester acrylates, polyether acrylates, epoxy resins, silicone resins, and the like.

  Further, as the metal alkoxide, silicate silicate is preferable, for example, from silicate alkoxide having a fluorine-containing functional group such as perfluoropolyether group and / or perfluoroalkyl group in addition to ethyl silicate, vinyl group and epoxy group. Silicate alkoxides containing one or more selected functional groups may also be used. Examples of the silicate alkoxide containing a perfluoropolyether group include perfluoropolyether triethoxysilane; and examples of the silicate alkoxide containing a perfluoroalkyl group include perfluoroethyltriethoxysilane; silicic acid containing a vinyl group. As alkoxide, vinyltrimethoxysilane, vinyltriethoxysilane; As silicate alkoxide containing epoxy group, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, Examples include 3-glycidoxypropylmethyldiethoxysilane and 3-glycidoxypropyltriethoxysilane.

The liquid in which the hollow silica particles are dispersed as described above may contain a surfactant in addition to the matrix component (binder component). This is because wettability to the transparent substrate is improved. As the surfactant, any of an anionic surfactant, a cationic surfactant, and a nonionic surfactant can be used. As the surfactant, —CH ₂ CH ₂ O—, —SO ₂ —, —NR— (R is a hydrogen atom or an organic group), —NH ₂ —, —SO ₃ Y, —COOY (Y is a hydrogen atom, Nonionic surfactants having a structural unit of sodium atom, potassium atom or ammonium ion are preferred.

  Nonionic surfactants include, for example, alkyl polyoxyethylene ether, alkyl polyoxyethylene-polypropylene ether, fatty acid polyoxyethylene ester, fatty acid polyoxyethylene sorbitan ester, fatty acid polyoxyethylene sorbitol ester, alkyl polyoxyethylene amine , Alkyl polyoxyethylene amide, polyether-modified silicone surfactants, and the like.

The dispersion containing the hollow silica particles as described above can contain various coating compounding agents in addition to the surfactant. For example, hard coat, coloring, conductivity, antistatic, polarization, UV shielding, infrared shielding, antifouling, antifogging, photocatalyst, antibacterial, phosphorescence, battery, refractive index control, water repellency, oil repellency, fingerprint removal, slipperiness, etc. One selected from two or more functions may be included.
Moreover, an antifoaming agent, a leveling agent, an ultraviolet absorber, a viscosity modifier, an antioxidant, an antifungal agent and the like can be contained. In addition, in order to color the antireflection film according to the purpose, various commonly used pigments such as titania, zirconia, lead white, bengara and the like can be blended.

An antireflection film can be formed by applying a dispersion containing hollow silica particles as described above to the surface of the transparent substrate and drying.
The application method is not particularly limited. For example, it can apply | coat by a well-known method. For example, roller coating, hand coating, brush coating, dipping, spin coating, dip coating, coating by various printing methods, curtain flow, bar coating, die coating, gravure coating, micro gravure coating, reverse coating, roll coating, flow coating, spray A coat, a dip coat, etc. are mentioned.

Further, for the purpose of increasing the mechanical strength of the antireflection film, heating, irradiation with ultraviolet rays, electron beams, or the like may be performed as necessary. The heating may be determined in consideration of the heat resistance of the substrate, but is preferably 60 to 700 ° C.
In order to further improve the adhesion of the antireflection film, plasma treatment, corona treatment, UV treatment, discharge treatment such as ozone treatment, chemical treatment such as water, acid or alkali, or physical treatment using an abrasive. Can be applied.

Also, the drying method is not particularly limited. For example, the substrate with an antireflection film of the present invention can be obtained by holding it in a drier at room temperature to 700 ° C. for about 1 to 60 minutes. Vacuum drying may be used.
In order to express the antireflection function, it is sufficient that the solvent is volatilized and the hydrolyzable compound is converted into a matrix component under a temperature condition of about room temperature to 200 ° C. However, when wear resistance is required, such as when applied to an automobile window, it is preferable that the film is maintained at a temperature of 500 to 700 ° C. to be a strong film.

<Production method B>
Next, the manufacturing method B which is another manufacturing method of the base | substrate with an antireflection film of this invention is demonstrated.
First, as the solvent, the same solvent as that used as the dispersion medium for the core fine particles in the production method A is prepared. In this production method B, core fine particles are not used.
Then, the same matrix component (binder component) as that used in production method A for the solvent and particulate organic matter (for example, acrylic resin, urethane acrylate resin, epoxy acrylate resin, polyester acrylate, polyether acrylate, epoxy resin, Silicone resin, cellulose resin, styrene resin, etc. (hereinafter also referred to as “organic substance B”) are added to obtain solution B. The same surfactant and other compounding agents as in production method A can also be added.

Next, the solution B is apply | coated to the surface of the said transparent base material by the coating method similar to said manufacturing method A. FIG.
Then, baking is performed at a temperature of 200 to 700 ° C. Then, since the organic substance B is vaporized, a substrate with an antireflection film that is porous and has a total pore volume of 1.0 × 10 ⁻³ mL / g or less can be obtained. The total pore volume can be adjusted by adjusting the mass ratio of the organic substance B to the matrix component.

Next, the manufacturing method C which is another manufacturing method of the base | substrate with an antireflection film of this invention is demonstrated.
In the production method C, first, an aqueous solution of silicate and / or an acidic silicic acid solution and an aqueous solution of an alkali-soluble inorganic compound are simultaneously added to an alkaline aqueous solution having a pH of 10 or more to prepare a core fine particle dispersion. .

  Examples of the silicate include alkali metal silicate, ammonium silicate, and organic base silicate. Examples of the alkali metal silicate include sodium silicate (water glass) and potassium silicate, and examples of the organic base include quaternary ammonium salts such as tetraethylammonium salt, amines such as monoethanolamine, diethanolamine, and triethanolamine. Examples of the ammonium silicate or organic base silicate include an alkaline solution obtained by adding ammonia, a quaternary ammonium hydroxide, an amine compound, or the like to a silicic acid solution.

  As the acidic silicate solution, a silicate solution obtained by removing alkali by treating an alkali silicate aqueous solution with a cation exchange resin or the like can be used.

Alkali-soluble inorganic compounds include Al ₂ O ₃ , B ₂ O ₃ , TiO ₂ , ZrO ₂ , SnO ₂ , Ce ₂ O ₃ , P ₂ O ₅ , Sb ₂ O ₃ , MoO ₃ , ZnO ₂ , WO Examples include alkali metal salts, alkaline earth metal salts, ammonium salts, and quaternary ammonium salts of oxo acids such as ₃ .

  In order to prepare the core fine particle dispersion, either an alkali aqueous solution of the inorganic compound is separately prepared in advance or a mixed aqueous solution is prepared, and the target silica and inorganic oxide other than silica are prepared. Depending on the composite ratio, the solution is gradually added to an aqueous alkali solution having a pH of 10 or more with stirring.

In the manufacturing method C, a silica source is then added to the core fine particle dispersion to form a silica coating layer on the core fine particles.
Here, the silica raw material to be added to form a silica coating layer is particularly preferably a silicic acid solution obtained by dealkalizing an alkali metal salt (water glass) of silica. When the dispersion medium of the core fine particles is water alone or the ratio of water to the organic solvent is high, coating treatment with a silicic acid solution is also possible. When a silicic acid solution is used, a predetermined amount of the silicic acid solution is added to the dispersion, and at the same time an alkali is added to deposit the silicic acid solution on the surface of the core fine particles. Furthermore, a hydrolyzable organosilicon compound can also be used as a silica raw material. As the hydrolyzable organosilicon compound, alkoxysilane can be used, and tetraalkoxysilane such as tetramethoxysilane, tetraethoxysilane, and tetraisopropoxysilane is particularly preferable.

  As an addition method, a solution obtained by adding a small amount of alkali or acid as a catalyst to a mixed solution of these alkoxysilane, pure water, and alcohol was added to the core fine particle dispersion, and the alkoxysilane was hydrolyzed. Silica polymer is deposited on the surface of the core fine particles. At this time, alkoxysilane, alcohol, and catalyst may be simultaneously added to the dispersion. As the alkali catalyst, ammonia, an alkali metal hydroxide, or an amine can be used. As the acid catalyst, various inorganic acids and organic acids can be used. In addition, it is also possible to perform the coating treatment by using the alkoxysilane and the silicic acid solution together. Moreover, it can also coat | cover with an inorganic compound other than a silica source if needed, and can use the alkali-soluble inorganic compound used for preparation of the said core fine particle. The silica coating layer may be porous having a large number of pores.

In the production method C, voids are formed inside the silica coating layer as the outer shell by removing part or all of the elements constituting the core fine particles from the core fine particles having the silica coating layer formed by the above method. Hollow silica particles having the following can be produced.
To remove some or all of the elements that make up the core fine particles, the core fine particle dispersion can be dissolved and removed by adding mineral acid or organic acid, or contacted with a cation exchange resin for ion exchange removal. The method of doing can be illustrated. The concentration of the core fine particles in the core fine particle dispersion at this time varies depending on the treatment temperature, but is preferably in the range of 0.1 to 50% by mass in terms of oxide.

  After the hollow silica particles are formed by the method as described above, a substrate with an antireflection film can be produced by the same method as Production Method A.

The substrate with an antireflection film of the present invention is suitably used as a window glass for transportation equipment such as automobiles. For example, it can be applied to the rear glass, side window glass, and roof glass of automobiles.
Moreover, the laminated glass used as a windshield etc. can also be obtained using the base | substrate with an antireflection film of this invention. That is, a laminated glass obtained by laminating a substrate with an antireflection film of the present invention, an intermediate film (for example, a transparent resin such as polyvinyl butyral or an ethylene-vinyl acetate copolymer), and other transparent substrates in this order is obtained. be able to. In this laminated glass, it is laminated so that the surface of the antireflection film is arranged on the vehicle interior side.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

[Example 1]
A hollow silica sol was obtained by the following procedure.
(1) In a glass reaction vessel having a capacity of 200 ml, ethanol 60 g, ZnO fine particle water dispersion sol (product of Sakai Chemical Industry Co., Ltd., product name: NANOFINE-50, average primary particle size 20 nm, average aggregated particle size 100 nm, solid content conversion) After adding 30 g of 10 mass%) and 10 g of tetraethoxysilane (SiO ₂ solid content of 29 mass%), an aqueous ammonia solution was added to adjust the pH to 10, and the mixture was stirred at 20 ° C. for 6 hours. 100 g of a fine particle dispersion (solid content concentration 6 mass%) was obtained.
(2) 100 g of strongly acidic cation exchange resin (manufactured by Mitsubishi Chemical Co., Ltd., trade name: Diaion, total exchange capacity of 2.0 (meq / ml) or more) is added to the obtained core-shell type fine particle dispersion for 1 hour. After stirring to pH = 4, the strongly acidic cation exchange resin was removed by filtration to obtain 100 g of a hollow SiO ₂ fine particle dispersion. The thickness of the outer shell of the SiO ₂ hollow particles was 10 nm, and the pore diameter was 20 nm. The SiO ₂ fine particles were aggregate particles, and the average aggregate particle size was 100 nm.
Hollow silica sol (0.7 g, solid concentration: 15% by mass) obtained by the above procedure, nitric acid partial hydrolyzate of tetraethoxysilane (2 g, solid concentration: 2.25% by mass), isopropanol (7.3 g) ) Were mixed at room temperature to prepare a coating solution. The obtained coating solution is designated as coating solution 1. The ratio between the hollow silica particles and the matrix component contained in the coating liquid 1 was 7: 3 (mass ratio) in terms of SiO ₂ .

  Next, the surface of a 3.5 mm thick green glass plate (trade name: UVFL, manufactured by Asahi Glass Co., Ltd.) was polished with fine particles of cerium oxide, and then the surface was washed with water. After drying, the coating liquid 1 is applied onto the surface by spin coating, dried in a hot air circulation oven at 200 ° C. for 5 minutes, and further baked in a muffle furnace at 600 ° C. for 5 minutes to form a substrate 1 with an antireflection film. Manufactured. The thickness of the antireflection film of the substrate 1 with the antireflection film was 135 nm. The rotation speed in spin coating was such that the visible light reflectance (Rv) was minimized when the formed substrate 1 with antireflection film was irradiated with light at an incident angle of 60 degrees.

For the substrate 1 with an antireflection film, the total pore volume (mL / g), visible light transmittance (Tv), and visible light reflectance (Rv) were measured. In addition, the soil removal property was evaluated.
The total pore volume was measured using a fully automatic gas adsorption amount measuring device (manufactured by Yuasa Ionics, Autosorb 1: Model AS-1MPV-6). Nitrogen gas was used for the measurement and analyzed by the DFT method. The measurement results of the total pore volume are shown in Table 1.
Visible light transmittance (Tv) and visible light reflectance (Rv) (JIS-R3106 (1999)) were measured and calculated using a spectrophotometer UV3100Ps (manufactured by Shimadzu Corporation). The reflectance is shown in FIG. FIG. 1 also shows the case of only a glass plate. The reflectance is a reflectance of only a pure film surface excluding back surface reflection. Table 2 shows the measurement results of the visible light transmittance (Tv) and the visible light reflectance (Rv). A light source A was used as the light source.

Further, the soil removability was evaluated by performing the following test.
First, oleic acid (2 mL) was applied to the surface of the antireflection film of the substrate 1 with the antireflection film with Kimwipe. Next, this was left in a 100 degree hot air circulation oven for 1 hour and then left at room temperature for 1 hour. Then, the portion where oleic acid was applied was washed away with water, and then the visible light transmittance (Tv (ii)) was measured. And the stain | pollution | contamination removal property was evaluated by the variation | change_quantity (difference of Tv and Tv (ii)) of the visible light transmittance before and after this test. Table 3 shows the measurement results.

[Example 2]
Chain silica sol (0.80 g, manufactured by Nissan Chemical Industries, Ltd., product number: IPA-ST-UP, solid content concentration: 15% by mass), nitric acid partial hydrolyzate of tetraethoxysilane (1.33 g, solid content concentration: 2.25% by mass) and isopropanol (7.87 g) were mixed at room temperature to obtain a coating solution. The obtained coating solution is designated as coating solution 2.
And using this coating liquid 2, the same operation as said Example 1 was performed, the base | substrate 2 with an antireflection film was manufactured, and the same evaluation was performed.
The ratio between the chain silica particles contained in the coating liquid 2 and the matrix component is such that the chain silica is such that the visible light reflectance of the base 2 with the antireflection film is the same as that of the base 1 with the antireflection film. The ratio of particles to matrix component was 8: 2 (mass ratio).

[Example 3]
Solid silica sol (0.45 g, manufactured by Nissan Chemical Industries, Ltd., product number: IPA-ST-L, agglomerated particle size 50 nm, solid content concentration: 30% by mass), nitric acid partial hydrolyzate of tetraethoxysilane (0.67 g) , Solid content concentration: 2.25 mass%) and isopropanol (8.88 g) were mixed at room temperature to obtain a coating solution. The obtained coating solution is designated as coating solution 3.
And using this coating liquid 3, the same operation as said Example 1 was performed, the base | substrate 3 with an antireflection film was manufactured, and the same evaluation was performed.
The ratio of the solid silica particles contained in the coating liquid 3 to the matrix component is such that the visible light reflectance of the substrate 3 with antireflection film is the same as that of the substrate 1 with antireflection film. The ratio of particles to matrix component was 9: 1 (mass ratio).

1 is a graph showing the reflectance of a substrate with an antireflection film of Example 1. FIG.

Claims (5)

A substrate with an antireflection film having an antireflection film on the surface of the transparent substrate,
The antireflection film includes hollow silica particles, and the total pore volume is 1.0 × 10 ⁻³ mL / g or less,
The transparent substrate is a glass plate;
The antireflection film is mainly composed of the hollow silica particles and a matrix component, and at least a part of the matrix component is a metal oxide,
A substrate with an antireflection film obtained by being held at a temperature of 500 to 700 ° C. The substrate with an antireflection film according to claim 1, wherein the hollow silica has an average aggregate particle diameter of 10 to 1000 nm . The hollow silica is produced by removing the core of the core-shell type fine particles,
The substrate with an antireflection film according to claim 1 or 2, wherein the core fine particles constituting the core are zinc oxide.   The base | substrate with an antireflection film in any one of Claims 1-3 whose thickness of the said antireflection film is 60-700 nm. A first transparent substrate; a second transparent substrate including an antireflection film; and an intermediate film interposed between the first transparent substrate and the second transparent substrate, wherein the second transparent substrate is Laminated glass for vehicle windows arranged inside the vehicle,
The laminated glass for vehicle windows, wherein the second transparent substrate provided with the antireflection film is the substrate with the antireflection film according to any one of claims 1 to 4.

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