JPH11292568A - Antireflection glass sheet, its production and coating composition for antireflection film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain small reflectance for visible light of a large incident angle and to improve visibility by coating the surface of a glass substrate with a film which has specified thickness and consists of chain silica fine particles and silica, and forming a rough surface of the film. SOLUTION: At least one surface of a glass substrate is coated with a film of 110 to 250 nm thickness comprising chain silica fine particles and silica by 5 to 30 wt.% of the chain silica, and the surface of the film is roughened. The obtd. film has voids in chain silica particles adjacent to each other in the film, and the film has 1.25 to 1.40 refractive index. The film surface has 5 to 50 nm numerical average roughness (Ra) with 10 to 300 nm average period (Sm) of roughness. A preferable film compsn. is obtd. by compounding 100 pts.wt. of a silicon compd., 100 to 800 pts.wt. of chain silica fine particles, 4 to 150 pts.wt. of water, 0.00001 to 5 pts.wt. of an acid catalyst, 0.001 to 10 pts.wt. of a dispersion assistant and 500 to 10000 pts.wt. of a solvent to prepare the coating liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an antireflection glass plate,
In particular, the present invention relates to a glass plate having low visible light reflectance and suitable for an automobile window, a method for producing the same, and a coating composition for an antireflection film.

[0002]

2. Description of the Related Art Conventionally, in order to prevent visible light from being reflected on the surface of a glass plate or other glass article to reduce the transparency and light transmittance and to prevent the glass article from being dazzled, anti-reflection is applied to the surface of the glass article. Processing has been performed.

For example, a low-refractive-index antireflection film is known in which a silica sol having a particle size of 5 to 30 nm and a coating solution containing a hydrolyzate of alkoxysilane in a solvent are applied to a substrate and cured. Kaihei 8-122501).

In a windshield of an automobile, light from an instrument panel (instrument panel), a dashboard, or the like in the vehicle is reflected on a surface of the windshield, and a reflection image of the instrument panel or the dashboard enters a driver's view. Therefore, there is a problem that the visibility in front of the driver is reduced. Light emitted from the instrument panel or dashboard and incident on the windshield at a considerably large incident angle and reflected enters the eyes of the driver. To improve the visibility, a high incident angle (for example, 60 degrees) is used. )
It is necessary to reduce the reflectance of the windshield at the window. The low-refractive-index antireflection film is not sufficient for reducing the reflectance at a high incident angle, and the visibility is not sufficiently high.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a glass sheet suitable for automobile windows, which has a small visible light reflectance at a high incident angle and has improved visibility.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a chain silica fine particle and 5 to 3 weight of the chain silica fine particle.
A visible light anti-reflection glass plate in which a film made of 0% by weight of silica and having a thickness of 110 to 250 nm is coated on at least one of the surfaces of the glass substrate, and the film surface has irregularities.

Further, according to the present invention, a film composed of chain silica fine particles and silica and having a thickness of 110 to 250 nm is coated on at least one of the surfaces of the glass substrate, and between the chain silica fine particles adjacent to each other in the film. , A film having a refractive index of 1.25 to 1.40, and having irregularities formed on the film surface, and having a small reflectance at a high incident angle. It is a board.

In the present invention, the surface of the glass substrate is coated with an antireflection film made of chain silica fine particles and silica, and the surface of the film is covered with the surface of the chain silica fine particles projecting therefrom. Irregularities due to the shape are formed.

The film is composed of chain silica fine particles and a smaller amount, preferably 5 to 30% by weight, based on the weight of chain silica fine particles, of silica having no particle shape. It is useful for the adhesion between the silica fine particles and the adhesion between the silica fine particles and the surface of the glass substrate.

The above-mentioned chain silica fine particles may have a linearly and linearly extending shape.
More preferably, a three-dimensionally curved shape is most preferably used. By using chain-like silica fine particles, in the film, between adjacent chain-like fine particles,
A gap (interval) having a width of 5 to 20 nm is formed. This gap has a much larger total volume than the gap formed if spherical silica fine particles of the same weight were used instead of chain silica fine particles. Moreover, since the amount of silica used as a binder for adhering the chain-like fine particles is small, the gap is not completely filled with the silica binder, and most of the gap is occupied by air or gas. ). Due to the presence of the voids, the value of the refractive index of the entire film becomes smaller than the refractive index of silica (about 1.45), and is 1.25 to 1.40.
Becomes The value of the refractive index of the antireflection film at which the reflectance is theoretically zero is the square root of the refractive index (1.50) of the glass substrate, that is, 1.225. Can approach this value.

If the amount of silica as a binder in the film is too small, for example, less than 5% by weight based on the weight of the chain silica fine particles, the adhesion of the chain silica fine particles becomes insufficient and the film becomes insufficient. The mechanical strength of Conversely, if the amount of silica is too large, for example, if it exceeds 30% by weight based on the weight of the chain silica fine particles, the silica fills the gaps between the chain silica fine particles and the voids are formed. Since it does not remain, the refractive index of the film cannot be reduced, and the reflectance cannot be lowered. The volume of the above-mentioned void, the refractive index of the actually measured film,
The amount of silica is increased with respect to the chain silica fine particles, and the volume of the entire film is calculated from the difference between the refractive index (about 1.45) of the film in which the gaps between the chain silica fine particles are filled with silica. It is estimated to be 50-80%.

Further, since fine irregularities mainly formed by the convex surface of the chain silica fine particles are formed on the film surface, the reflected light is diffused to prevent the reflection image from being reflected and the resolution of the perspective image is reduced. Not even. If the amount of silica as a binder in the film is too large, the whole chain silica fine particles sink below the silica. Therefore, the arithmetic average roughness (Ra) of the film surface described later is 5 nm.
And the average interval (Sm) of the irregularities on the film surface is 3
It is more likely to exceed 00 nm, and reflection of a reflected image cannot be effectively prevented. Therefore, in order to lower the refractive index of the film without lowering the mechanical strength of the film, and to form the irregularities on the film surface, the amount of silica in the film is based on the weight of the chain silica fine particles. The content is preferably 5 to 30% by weight, more preferably 10 to 20% by weight.

The size of the chain silica fine particles is 10 to
It preferably has an average diameter of 20 nm and an average length of 60 to 200 nm. Here, the average diameter is a value obtained by measuring the diameter of each of the 100 samples taken out using an electron microscope, and averaging the measured values with a weight proportional to the volume. Measures the length of each of the 100 samples taken out (if curved, the length along the bend) using an electron microscope, weights the measured values in proportion to the volume, and calculates the average. Value.

When the average diameter of the chain silica fine particles is less than 10 nm or the average length is less than 60 nm, (1) the total volume of the gap between the adjacent fine particles becomes small, and therefore the total volume of the void becomes small. The value of the refractive index of the film cannot be reduced, and (2) the arithmetic average roughness (Ra) of the obtained film surface is less than 5 nm, which is sufficient to prevent the reflection image from being reflected. It is not preferable because effective unevenness cannot be formed. When the average diameter exceeds 20 nm or the average length exceeds 200 nm, the arithmetic average roughness (Ra) of the film surface becomes larger than 50 nm, so that haze is easily generated or the resolution of a fluoroscopic image is easily reduced. Therefore, the visibility is not preferred.

Here, the arithmetic average roughness (Ra) and the average interval of unevenness (Sm) are measured by an atomic force microscope (AFM) (manufactured by Seiko Electronics Co., Ltd., scanning probe microscope “SP”).
I3700 ”, cantilever; Silicon“ SI-DF ”
JIS B 06 defined in two dimensions using “20”).
01 (1994) in a three-dimensionally extended manner. In this case, the measurement area of the sample is 1 μm × 1 μm.
m, measuring points 512 × 256 points, scan speed 1.02 Hz, surface shape measured by DFM (cyclic contact mode), correction by low-pass filter and leveling correction of measured data (by least square approximation A curved surface was determined and fitted, the inclination of the data was corrected, and the distortion in the Z-axis direction was removed.), And the surface roughness Ra and Sm value were calculated. In addition to the atomic force microscope, it can be calculated from the cross-sectional curve observed and measured using an electron microscope (for example, H-600 manufactured by Hitachi, Ltd.).

When the surface of the glass substrate is coated with a film having a refractive index (n) and a film thickness (d) smaller than the refractive index of the glass substrate, the condition for minimizing the reflectance at the incident angle α is as follows. ,
λ is the wavelength of light, and m is zero or a positive integer, and is represented by the following Equation 1.

D (n ² −sin ² α) ^1/2 = λ (1 + 2m) / 4 (1)

The film thickness (d) that minimizes the visible light reflectance at a high incident angle, for example, an incident angle of 60 degrees, is given by
60, m = 0, which is obtained by substituting Equation 2 below. In Equation 2, the film having the refractive index n is 38 in the visible light range.
If the thickness (d) of the following formula is satisfied at any wavelength λ of 0 to 780 nm, the reflectance of light of that wavelength can be minimized. If m is 1 or 2 or more, it is not preferable because the film thickness becomes extremely large and the absorption of visible light increases. As described above, the refractive index of the film composed of chain silica fine particles and silica in the present invention is 1.2.
Since it is 5 to 1.40, the film thickness at which the visible light reflectance becomes minimum is 86 to 216 nm from the above equation (2). However, the film thickness in the present invention is defined as the height from the surface of the glass plate to the top of the convex portion of the film having surface irregularities. Accordingly, the film thickness of this definition is larger by about the same as the arithmetic average roughness (Ra) of the film surface as compared with the film thickness of the above-mentioned formula 2, so that the film thickness in the present invention is actually 110 to 250 nm. Preferably, there is.

D = (λ / 4) × (n ² −3/4) ^−1/2 (2)

The film composed of chain silica fine particles and silica is formed on one or both surfaces of a glass substrate. When both surfaces of the glass plate are used facing a medium having a refractive index close to 1 such as air or gas, forming this film on both surfaces of the glass substrate provides a higher antireflection effect.
However, when one surface of the glass substrate is used to face a medium having a refractive index close to that of the glass substrate, for example, when two glass plates are bonded therebetween via a transparent resin layer such as polyvinyl butyral. Since the visible light reflection at the interface between the glass plate and the transparent resin layer can be neglected, the film composed of chain silica fine particles and silica is not formed on the surface of the glass plate facing the transparent resin layer. It is sufficient to form it only on the outer surface of each glass plate.

The chain silica fine particles are preferably used in the form of a solvent-dispersed sol. Examples of the chain silica fine particle sol include, for example, "Snowtex-OUP" and "Snowtex-UP" manufactured by Nissan Chemical Industries, Ltd.
These have an average diameter of 10-20 nm and 60-200 nm.
And has a three-dimensionally curved shape.

The solvent for the fine particles is not particularly limited as long as the fine particles are substantially stably dispersed, but water, methanol, ethanol, propanol, ethyl cellosolve,
A simple substance or a mixture such as butyl cellosolve and propyl cellosolve is preferable, and water and propyl cellosolve are more preferable. These water and lower alcohol are good because they are easily mixed with the solution containing the organometallic compound and can be easily removed by heat treatment after film formation. Of these, water and propyl cellosolve are most preferred in the production environment.

In the present invention, the coating of the silica film having the surface irregularities on the glass substrate may be performed, for example, by forming chain silica fine particles, a hydrolyzable / polycondensable organosilicon compound, a chlorosilyl group-containing silicon compound and their hydrolysis. A liquid containing at least one kind of silicon compound selected from the group consisting of materials is applied to a glass substrate to form a liquid.

When the fine particles are added to the solution containing the above-mentioned hydrolyzable / polycondensable organic silicon compound or chlorosilyl group-containing silicon compound, a dispersing aid may be added. The dispersion aid is not particularly limited, and commonly used additives, for example, sodium phosphate, sodium hexametaphosphate,
Electrolytes such as potassium pyrophosphate, aluminum chloride, and iron chloride, various surfactants, various organic polymers, silane coupling agents, titanium coupling agents, and the like are used. .01-5
% By weight.

The hydrolyzable and polycondensable organic silicon compound contained in the solution together with the silica fine particles may be basically any compound as long as it hydrolyzes and dehydrates and condenses. Silicon chelates are preferred.

Specifically, silicon alkoxides such as methoxide, ethoxide, propoxide and butoxide of silicon are preferably used alone or as a mixture.
As the silicon chelate, an acetylacetonate complex of silicon is preferably used.

As the organic silicon compound, a high molecular weight alkyl silicate such as "Ethyl silicate 40" manufactured by Colcoat Co., Ltd. or "MS56" manufactured by Mitsubishi Chemical Corporation can be used.

As the organic silicon compound hydrolyzate, commercially available alkoxysilane hydrolyzates such as “HAS-10” manufactured by Colcoat Co., Ltd., and “Ceramica G-91” and “G-92-” manufactured by Nippon Research Institute Co., Ltd. 6 "and" Atron NSI-500 "manufactured by Nippon Soda Co., Ltd. can be used.

The chlorosilyl group-containing compound to be contained in the solution together with the chain silica fine particles is a chlorosilyl group (—SiCl _n X _3-n , where n is 1, 2, or 3; X is hydrogen; Or an alkyl group having 1 to 10 carbon atoms, an alkoxy group, or an acyloxy group) in the molecule, and among them, a compound having at least 2 chlorines is preferable,
At least two hydrogens in silane Si _n H _{2n + 2} (where n is an integer of 1 to 5) are substituted with chlorine, and other hydrogens are optionally substituted with the above-mentioned alkyl, alkoxy or acyloxy group. Chlorosilanes and polycondensates thereof are preferred, for example, tetrachlorosilane (silicon tetrachloride, S
iCl ₄ ), trichlorosilane (SiHCl ₃ ), trichloromonomethylsilane (SiCH ₃ Cl ₃ ), dichlorosilane (SiH ₂ Cl ₂ ), and Cl— (SiCl ₂ O) n—S
iCl ₃ (n is an integer of 1 to 10) and the like. A hydrolyzate of the above-mentioned chlorosilyl group-containing compound can also be used, and among these, a single compound or a combination of two or more compounds can be used. The most preferred chlorosilyl group-containing compound is tetrachlorosilane.
The chlorosilyl group has a very high reactivity and exhibits strong adhesive force by self-condensing or by performing a condensation reaction with the substrate surface.

The above-mentioned chain silica fine particles are dispersed, and the above-mentioned organic silicon compound or chlorosilyl group-containing compound is
Alternatively, the solvent of the solution containing the hydrolyzate may be basically any solvent as long as the organic silicon compound or the hydrolyzate thereof is substantially dissolved, but alcohols such as methanol, ethanol, propanol and butanol, and ethyl cellosolve may be used. , Butyl cellosolve and propyl cellosolve are most preferred. If the concentration of the organosilicon compound dissolved in the solvent is too high, the amount of dispersed chain silica fine particles is also involved, but it is not possible to generate sufficient voids between the fine particles in the film, It is preferably at most 20% by weight, and more preferably at a concentration of 1 to 20% by weight. The amount (total) of the organosilicon compound or the chlorosilyl group-containing compound or the hydrolyzate thereof with respect to the amount of the chain silica fine particles in the solution is 5 parts per 100% by weight of the chain silica fine particles in terms of silica. ~ 30% by weight is preferred.

Water is required for the hydrolysis of the organosilicon compound. This may be either acidic or neutral, but it is preferable to use water acidified with hydrochloric acid, nitric acid, sulfuric acid, acetic acid, citric acid, sulfonic acid or the like in order to promote hydrolysis. The amount of the acid added is not particularly limited, but is preferably 0.001 to 2 in a molar ratio to the organic silicon compound. When the amount of the added acid is less than 0.001 in molar ratio, the promotion of hydrolysis of the organosilicon compound is not sufficient, and when the amount is more than 2, the effect of promoting hydrolysis is no longer improved, which is preferable. Absent.

The amount of water required for the hydrolysis of the above organosilicon compound is 0.1 to 0.1 mol per mol of the organosilicon compound.
100 is good. If the amount of water added is less than 0.1 in terms of molar ratio, the promotion of hydrolysis of the organosilicon compound is not sufficient, and if the amount is more than 100, the stability of the solution tends to decrease, which is not preferable.

When the chlorosilyl group-containing compound is used, it is not always necessary to add water or an acid. Even if no additional water or acid is added, hydrolysis proceeds due to moisture contained in the solvent or moisture in the atmosphere.
In addition, hydrochloric acid is released into the liquid with the hydrolysis, and the hydrolysis further proceeds. However, it does not matter if water or acid is additionally added.

The above-mentioned chain silica fine particles and the above-mentioned organosilicon compound, chlorosilyl group-containing compound or a hydrolyzate thereof are mixed together with a solvent, and if necessary, water, an acid catalyst and a dispersing agent are added. A coating solution for forming irregularities on a substrate is prepared. At this time, the organometallic compound and the chlorosilyl group-containing compound may be used alone or in combination. The preferred raw material mixing ratio of this coating liquid is as shown in Table 1 below. Here, the silicon compound represents the above-mentioned organic silicon compound, chlorosilyl group-containing compound, or a hydrolyzate thereof in total.

[0033]

Table 1 ====================== 100 parts by weight of silicon compound 100 to 800 parts by weight of fine chain silica particles 4 to 150 parts by weight of water Acid catalyst 0. 00001 to 5 parts by weight Dispersing aid 0.001 to 10 parts by weight Solvent 500 to 10000 parts by weight =======================

The above organometallic compound or chlorosilyl group-containing compound is dissolved in a solvent, a catalyst and water are added, and the mixture is hydrolyzed at a predetermined temperature between 10 ° C. and the boiling point of the solution for 5 minutes to 2 days. Chain silica fine particles and a dispersing aid are added to the mixture, if necessary, and the mixture is further reacted, if necessary, at a predetermined temperature between 10 ° C. and the boiling point of the solution for 5 minutes to 2 days to obtain a coating liquid. When a chlorosilyl group-containing compound is used, it is not necessary to add a catalyst and water.
The chain silica fine particles may be added before the hydrolysis step. Further, in order to omit the step of hydrolyzing the organic silicon compound, the above-mentioned commercially available organic metal compound hydrolyzate solution may be used. The obtained coating liquid may be subsequently diluted with an appropriate solvent according to the coating method.

The above coating solution is applied on a glass substrate and dried to form a silica uneven film on the glass substrate.

The above-mentioned coating method is not particularly limited as long as a known technique is used, but a method using an apparatus such as a spin coater, a roll coater, a spray coater, a curtain coater, a dipping and pulling method (dip coating method), and a flow method Various printing methods such as a coating method (flow coating method) and screen printing, gravure printing, and curved surface printing are used.

Depending on the glass substrate, it may not be possible to apply the coating solution uniformly by repelling the coating solution.
This can be improved by cleaning or modifying the surface of the substrate. As a method of cleaning or surface modification, alcohol, acetone, degreasing cleaning with an organic solvent such as hexane, cleaning with an alkali or acid, a method of polishing the surface with an abrasive,
Examples include ultrasonic cleaning, ultraviolet irradiation treatment, ultraviolet ozone treatment, and plasma treatment.

The glass substrate after coating is heated from room temperature to 200 ° C.
By drying at a temperature between 1 minute and 2 hours, a silica uneven film is formed. Then, if necessary, 40
When heat treatment is performed at a temperature between 0 ° C. and 750 ° C. for 5 seconds to 5 hours, the silica unevenness film on the surface of the glass substrate becomes strong. This uneven film is composed of a matrix of chain silica fine particles and silica (derived from an organometallic compound), and the chain silica fine particles are fixed to a glass substrate by the silica matrix, and the surface shape of the chain silica fine particles reduces the unevenness of the film. Form.

As the glass substrate before being coated,
It may be a glass plate such as a windshield, a rear window, a front door, or a rear door for an automobile after the bending process and the joining process, and is cut to a predetermined size before the joining process, or before the bending process. The front glass plate may be used.

The glass sheet for automobiles coated with the silica unevenness film can be further coated with a water-repellent coating or an anti-fog coating on its surface. By coating with a water-repellent film, water-repellent performance can be obtained, and when dirt adheres, the dirt-removing property can be improved. The antifogging performance can be obtained by coating the antifogging water-based coating, and when dirt adheres, the dirt removability can be improved. Glass plate (Laminated glass plate may be used)
Both surfaces may be coated with a silica uneven film, and one or both surfaces may be coated with a water-repellent film.One surface of a glass plate is coated with a silica uneven film, and the silica uneven film and untreated. A water-repellent coating may be coated on both or either of the glass surfaces. Even when the water-repellent coating is coated on the silica uneven film, the visible light antireflection performance and the visibility are not reduced.

Similarly, both surfaces of a glass plate (which may be a laminated glass plate) may be coated with a silica uneven film, and at least one surface thereof may be coated with an antifogging film. Good) may be coated with a silica uneven film, and an antifogging film may be coated on both the silica uneven film and the untreated glass surface or any one of them.

When the present invention is applied to an automobile window, both surfaces of a glass plate (which may be a laminated glass plate) are coated with a silica uneven film, and one surface of the film (the inside of the vehicle) is defogged. It is preferable that a water-repellent film be coated on the other side of the layer film surface (outside of the vehicle).

[0043]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

Example 1 3.0 parts by weight of a hydrolytic condensation polymerization solution of ethyl silicate (trade name: HAS-10, manufactured by Colcoat Co., Ltd., SiO ₂ content: 10% by weight) and an average diameter of about 15 nm Chain silica colloid having a length of about 170 nm (trade name: Snowtex OUP, manufactured by Nissan Chemical Industries, Ltd., solid content 15% by weight, containing a dispersing aid) 1
3.3 parts by weight and 74.9 parts by weight of 2-propanol are mixed at room temperature, diluted 3 times by weight with 2-propanol, and stirred at room temperature for 2 hours to form a low refractive index uneven layer. A coating liquid was obtained. The coating liquid contained chain silica fine particles and ethyl silicate in a weight ratio of 100: 15 in terms of silica, respectively. The coating solution contained 670 parts by weight of chain silica fine particles, 45 parts by weight of water, 4.5 parts by weight of an acid catalyst, and a solvent with respect to 100 parts by weight of the silicon compound.

A soda lime silicate glass plate (65 mm × 150 mm × 3 mm) which has been subjected to surface polishing and washing with a cerium oxide-based abrasive, and further subjected to ultrasonic washing in pure water and dried.
Was immersed in the coating liquid for forming a low-refractive-index uneven layer, and pulled up at a speed of 20 cm / min to apply the coating liquid on both surfaces of the glass plate. This glass plate was dried at 100 ° C. for 30 minutes, further dried at 250 ° C. for 30 minutes, and then heat-treated in a 500 ° C. oven for 1 hour to obtain a glass plate having a 140 nm thick silica uneven film formed on each surface. Was. The thickness of 140 nm is such that the reflectance is minimum when the incident angle (α) is 60 degrees,
That is, assuming that the refractive index (n) of the film is 1.340, 550
For light having a wavelength (λ) of nm, the film thickness is substantially equal to the value 134 nm calculated by the above equation (2).

The thickness of the silica uneven film, the refractive index of the film, the film porosity and the film surface roughness, and the visible light reflectance and visibility of the glass plate with the silica uneven film were measured as follows. Thickness of silica concavo-convex film: The cross section of the glass plate coated with the silica concavo-convex film was observed with an electron microscope at a magnification of 100,000, and the height from the surface of the glass plate to the top of the convex portion of the concavo-convex film was defined as the film thickness. Refractive index of the film; a value at a light having a wavelength of 550 nm is determined by an ellipsometer. Membrane porosity: Calculated by measuring the size of voids from electron micrographs.

Film surface roughness: The film was observed using an atomic force microscope (SPI3700, manufactured by Seiko Denshi Co., Ltd.).
The arithmetic average roughness (Ra value) and the average interval of unevenness (Sm value) were measured according to JIS B 0601 (199).
4) The value defined by the method described was calculated.

Visible light reflectance: The reflectance of visible light (380 to 780 nm wavelength) at incident angles of 12 degrees and 60 degrees was measured using a spectrophotometer (MCPD-1000, manufactured by Otsuka Electronics Co., Ltd.).
Was used to measure the reflected light from both sides of the glass plate.

Visibility: When a glass plate with an uneven silica film is attached to one side (right half) of a windshield of an automobile and an untreated glass plate is attached to the other side (left half), and the outside of the vehicle is viewed from the inside of the vehicle. The sensory evaluation was made by comparing the left and right glass plates to see how easily the scenery in front could be seen, that is, the degree of obstruction of the view due to the reflection of the inpane. The evaluation criteria were based on the criteria shown in Table 2 below, in 1 to 5 stages. Table 3 shows the measurement results.

[0050]

[Table 2] ================================== Visibility Sensory Evaluation Criteria Score Criteria ---- −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− 1: Inconspicuous in the image, and it is difficult to see the scenery ahead. 2: The image in front is slightly anxious, but if you look carefully, you can see the scenery ahead. 3: There is a little reflection in the image, but the scene in front is easily visible. 4: There is almost no reflection in the image, and the front scene is almost clear. 5: The scenery ahead is clearly visible without any reflection in the image. ===================================

Comparative Example 1 A silica colloid having a particle diameter of 50 nm (trade name: Snowtex OL, Nissan Chemical Industries, Ltd.) was used instead of 13.3 parts by weight of the chain silica colloid of the coating solution used in Example 1. Made, solid content 20
In the same manner as in Example 1, both surfaces of the glass plate were coated with 10.0 parts by weight of a coating liquid (containing silica fine particles and ethyl silicate in a weight ratio of 100: 15 in terms of silica) using 10.0 parts by weight. Dip coating, drying, and heat treatment were performed to obtain glass plates having a 118-nm-thick silica uneven film formed on each surface. The film thickness of 118 nm is a condition that the reflectance is minimum when the incident angle (α) is 60 degrees, the refractive index (n) of the film is 1.454, and the wavelength λ of 550 nm is used.
The condition that the optical film thickness becomes 4 / λ with respect to the above light, that is, the film thickness is equal to the value 118 nm calculated by the above equation (2). Table 3 shows the measurement results of the thickness, the refractive index, the film porosity, and the film surface roughness of the obtained silica uneven film, the visible light reflectance of the glass plate with the silica uneven film, and the visibility.

[Comparative Examples 2 and 3] The amount of chain silica fine particles in the coating liquid was changed to 20 parts by weight of 3.0 parts by weight of the hydrolyzed polycondensation solution of ethyl silicate in the coating liquid used in Example 1. Ethyl silicate,
A glass plate having a 120-nm-thick silica concavo-convex film formed on each surface by dip coating, drying and heat treatment on both surfaces of the glass plate in the same manner as in Example 1 except that the weight ratio was 50:50 in terms of silica. Was obtained (Comparative Example 2). Note that this film thickness of 120 nm is a condition that the reflectance becomes minimum when the incident angle (α) is 60 degrees, the refractive index (n) of the film is 1.432, and the optical film has a wavelength λ of 550 nm. 4 / λ thickness
, That is, the film thickness is substantially equal to the value 121 nm calculated by the above equation (2).

Also, dip coating, drying and heat treatment were applied to both surfaces of the glass plate in the same manner as in Example 1 except that the amount of the chain silica colloid used in the coating solution was set to zero.
A glass plate having a 5-nm silica film formed on each surface was obtained (Comparative Example 3). The film thickness of 115 nm is a condition that the reflectance is minimum when the incident angle (α) is 60 degrees, the refractive index (n) of the film is 1.473, and the wavelength λ of 550 nm.
The film thickness is 115n calculated from the above equation 2
equal to m. Table 3 shows the measurement results of the thickness, the refractive index, the film porosity, and the film surface roughness of the obtained silica uneven film, the visible light reflectance of the glass plate with the silica uneven film, and the visibility. In addition, untreated glass plate (refractive index 1.
5) The visible light reflectance at the incident angles of 12 degrees and 60 degrees is
They are about 7% and about 14%, respectively.

[0054]

Table 3 =================================== Surface Roughness Visible Light Reflectance (%) Visual film thickness Folded porosity (nm) −−−−−−−− Recognition (nm) Percentage (vol%) −−−−− Incident angle Incident angle Ra Sm 12 ° 60 ° −−−−−−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−− Example 1 140 1.340 60 7 20 0.8 1.9 5 Comparative Example 1 118 1.454 15 6 20 1.8 4.3 4 Comparative Example 2 120 1.432 2 5-4 8 3 Comparative Example 3 115 1.473 0 0-8 14.5 1 ================================= ====

Example 2 The soda lime silicate glass plate (65 mm × 150 mm × 3 m) used in Example 1 was used.
m) instead of an automotive windshield glass sheet (about 150 c) having the same soda-lime silicate glass composition
m × about 60 cm × 3 mm), dip-coated and dried in the same manner as in Example 1, and then subjected to a known bending step (15 ° C. at 570 ° C.).
(Heating for 1 minute) to produce an automotive windshield glass plate having a 120-nm-thick silica uneven film formed on each surface.

When the thickness of the uneven film, the refractive index of the film, the film porosity, the film surface roughness, the visible light reflectance, and the visibility of this glass plate were measured, the same results as in Example 1 were obtained. . As for the strength of the film, the film was rubbed 100 times using a cotton cloth with a commercially available glass cleaner while applying a load of 500 gf. Then, the film was observed with the naked eye to determine whether there was any abnormality. The test was repeated and counted. Example 1 showed an abnormality after 300 rubs, but Example 2 showed no abnormality until 5000 rubs.

Two glass plates for an automobile windshield having the above-mentioned silica uneven film are prepared, and are passed through a known laminating process, and are joined together via a 0.7 mm-thick polyvinyl butyral interlayer. A laminated glass plate was obtained. This laminated glass plate exhibited almost the same visible light reflectance and visibility as those in Example 1.

Example 3 A 1 liter glass reactor equipped with a thermometer, stirrer and cooler was charged with the formula C ₈ F ₁₇
Perfluoro group-containing organic silicon compound 10.0 g represented by CH ₂ CH ₂ Si (OCH ₃ ) ₃ , and hydrolyzable group-containing methyl polysiloxane compound 10.0 represented by the following chemical formula 1
g, 360.0 g of t-butanol, and 1.94 g of a 0.1 N aqueous hydrochloric acid solution, and subjected to a cohydrolysis reaction at 80 ° C. for 5 hours.
60.0 g was added and the mixture was stirred at room temperature for 10 hours.

[0059]

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Next, this is represented by the following chemical formula 2:
10.0 g of organopolysiloxane and 5.0 g of methanesulfonic acid were added and stirred for 10 minutes to obtain a composition for forming a water-repellent film.

[0061]

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The above water-repellent film-forming composition (0.1 ml) was applied 10 times with a cotton cloth to the surface of one of the concave-convex layers of the glass plate coated with the silica concave-convex layer obtained in the above Example 1, and then was applied with a dry cloth. After wiping off the liquid, heat treatment was performed at 100 ° C. for 10 minutes to obtain a low-reflection water-repellent glass plate having a water-repellent film having a thickness of 40 nm. The appearance of the water-repellent film was good by visual observation of the presence or absence of abnormality.

The contact angle of the obtained water-repellent film with water was measured using a contact angle meter (“CA-DT” manufactured by Kyowa Interface Science Co., Ltd.). Abrasion,
Chemical resistance and weather resistance tests were performed. The higher the contact angle, the better the water repellency. As shown in Table 4, the contact angle after the weather resistance test was low, but the initial contact angle, the contact angle after the wear resistance test, and the chemical resistance. The contact angles after the property test were all 95 degrees or more, which were very excellent.
Then, for this low-reflection water-repellent glass plate, light was incident from the surface opposite to the surface of the water-repellent film, the visible light reflectance was measured, and the visibility was measured with the water-repellent film surface facing the outside of the vehicle. However, the initial value, the value after the abrasion resistance test, and the value after the chemical resistance test were all equivalent to those of Example 1.

The abrasion resistance test was carried out by attaching a dry cloth to a reciprocating abrasion tester manufactured by Shinto Kagaku and applying a load of 0.3 k
The chemical resistance test was performed by measuring the contact angle after 3,000 reciprocations on the surface of the water-repellent film at g / cm ² , and by measuring the contact angle after immersion in a saturated lime aqueous solution for 24 hours. The irradiance was 76 ± 2 using the weather resistance tester “I-Super UV Tester W13” (Iwasaki Electric).
The measurement was performed by measuring the contact angle after irradiating with ultraviolet light for 400 hours under the conditions of mW / m ² , black panel temperature of 48 ± 2 ° C., and showering for 30 seconds every hour.

[0065]

[Table 4] ================================== Water-repellent film Initial ------ −− Contact angle Wear resistance Chemical resistance Weather resistance Film thickness (nm) Appearance quality (degree) (degree) (degree) (degree) −−−−−−−−−−−−−−−−−−−−−− Example 3 40 Good 107 100 101 85 ========================= ==========

Example 4 1 ml of 0.1N acetic acid was added to 1000 ml of commercially available ethanol (99.5%) and stirred. 4 g of [methoxy (polyethyleneoxy) propyl] trimethoxysilane ("SIM6492.7" manufactured by Chisso Corporation, content: 90%, molecular weight: 460 to 590, ethylene oxide unit: 6 to 9) is added to 796 g of the liquid mainly composed of ethanol. The mixture was added and stirred at 30 ° C. for 1 hour to prepare an organosilane coating solution.

The glass plate coated with the silica uneven layer obtained in Example 1 was ultrasonically washed in pure water, dried, immersed in the organosilane coating solution, and pulled up at a speed of 5 cm / min. The liquid was applied on both surfaces of a glass plate provided with a silica uneven film. The glass plate was dried and heat-treated at 120 ° C. for 30 minutes, cooled to room temperature, and then washed lightly with pure water to form an anti-fogging layer having a thickness of about 8 nm containing an organosilane layer containing polyethylene oxide groups in the molecule. A glass plate with a functional silica uneven film was obtained.

The low-reflection anti-fog glass plate was irradiated with light, the visible light reflectance was measured, and the visibility was measured. The result was exactly the same as that of Example 1. Further, the glass plate with the antifogging silica uneven film was subjected to surface roughness measurement, contact angle measurement, and initial and repeated antifogging evaluation by the following methods. These measurement results have excellent anti-fog performance as shown in Table 5, and dirt is hardly adsorbed.
It was found to have good antifogging maintenance and antifouling performance.

[0069]

[Table 5] ================================= Surface Roughness Initial Repetition Antifogging (nm) −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−−−−−−−−−−−−−−−−−−−−−− Example 4 6 20 3 ◎ ◎ 4 5 ================= =================

Measurement of Surface Roughness and Contact Angle Regarding the glass plate on which the above-mentioned organosilane-coated silica concavo-convex film was formed, the arithmetic average roughness (Ra) and the average interval of concavo-convex (Sm) were determined using the silica concavo-convex film of Example 1. Was determined in the same manner as in the measurement. Further, the contact angle with respect to a 0.4 mg water drop was measured using a contact angle meter (“C” manufactured by Kyowa Interface Science Co., Ltd.).
A-DT "). The smaller the value of the contact angle, the better the antifogging property.

Evaluation of anti-fogging property The glass plate on which the anti-fogging silica uneven film was formed was placed in a thermo-hygrostat at a temperature of 5 ° C. and a relative humidity of 10%, and allowed to stand for 10 minutes. The glass plate was transferred into a constant temperature / humidity chamber of 70% humidity, and observed with both the degree of cloudiness from the lapse of 30 seconds to the lapse of 2 minutes and the degree of distortion of the perspective image after the lapse of 2 minutes. The state of adhesion of water droplets on the surface of was evaluated, and a four-step evaluation shown in Table 6 was performed.

[0072]

[Table 6]

Repeated evaluation of anti-fog property The above-mentioned sample plate was placed in a cooling device (made of transparent plastic) described in JIS S 4030-1995 “Testing method for anti-fog agent for spectacles”. Was kept at 20 ° C. While cooling the sample in this state, it was placed in a thermo-hygrostat at a temperature of 45 ° C. and a relative humidity of 80% RH, and kept for 3 minutes. Thereafter, the sample was placed in a thermo-hygrostat at a temperature of 20 ° C. and a relative humidity of 10% RH while being attached to the cooling device, and dried for 3 minutes.
The operation of exposure to the high humidity atmosphere and the exposure to the low humidity atmosphere were defined as one cycle, and 30 cycles were repeated.

After this repetitive operation, a test chart for judging the perspective distortion printed on the plastic plate was attached to the back surface of the cooling device, water was soaked in a gap between the plate and the back surface of the cooling device, and the perspective distortion judgment was performed from the sample side. Test chart was made available for observation. The test chart for perspective distortion determination is similar to the test chart shown in FIG. 1 of JIS S 4030-1995. The length of three white lines is 10 mm, the line width and the interval are 0.15 mm,
0.5mm, 1.0mm, 1.5mm, 2.0mm 5
It was a stage. The cooling water temperature of the cooling device to which the sample is attached is reduced to 5 ° C., and the temperature is 25 ° C. and the relative humidity is 80 ° C.
% RH was placed in a constant-temperature and constant-humidity bath, and the occurrence of fogging and perspective distortion was examined using the test chart for determining perspective distortion, and a six-step evaluation was performed based on the criteria shown in Table 7.

[0075]

Table 7 ================================== Haze Evaluation Haze State------- -------------------------------------------------5 No fogging 2 60% or more of the area is fogged 1 80% or more of the area is fogged 0 Almost the entire area is fogged =========================== ======== Perspective Distortion Evaluation Perspective Distortion State −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− 5 No distortion 4 It is difficult to recognize white lines at intervals of 0.15 mm 3 It is difficult to recognize white lines at intervals of 0.5 mm or less 2 It is difficult to recognize white lines at intervals of 1.0 mm or less 1 1.5 mm White lines at the following intervals Separated and difficult to recognize white lines at intervals of 2.0 mm or less ===================================== ====

Example 5 Thickness 12 obtained in Example 2
Two glass plates for automobile windshield, each having a 0 nm silica uneven film formed on each surface, are vacuum-pressed at about 140 to 150 ° C. in an autoclave with a polyvinyl butyral film having a thickness of about 0.5 mm interposed therebetween. To obtain a laminated glass plate. On the inside surface of this laminated glass plate,
The organosilane coating solution used in Example 4 was gravure coated with a solution obtained by adding an appropriate amount of a viscosity modifier, dried and heat-treated at 120 ° C. for 30 minutes, cooled to room temperature, and then lightly washed with pure water. An anti-fog organosilane layer having a thickness of about 8 nm containing polyethylene oxide groups in the molecule was coated on the inside.

Then, the glass plate was coated 10 times with a cotton cloth to which 1.0 ml of the water-repellent film forming composition prepared in Example 3 was adhered, and the excess coating solution was wiped off with a dry cloth. Thereafter, heat treatment was performed at 100 ° C. for 10 minutes to impart low reflection water repellency to the outer surface of the vehicle.

As a result, when viewed from the outside of the vehicle, an automobile in which a water-repellent coating, a silica uneven film, a glass plate, a silica uneven film, a polyvinyl butyral film, a silica uneven film, a glass plate, a silica uneven film, and an anti-fog film are laminated in this order. A glass sheet for windshield was obtained.

The anti-fogging performance of the inside surface of the glass plate and the water repellency of the outside surface of the vehicle were measured.
It was found to have the same good anti-fog performance as the measurement result of, and the same good water repellency as the measurement result of Example 3. Then, for this glass plate, the visible light reflectance was measured by irradiating light from the anti-fog film surface, and the visibility was measured with the water-repellent film surface outside the vehicle. In each case, the same results as in Example 1 were obtained.

Since the refractive index of the polyvinyl butyral film is almost equal to that of the glass plate, the silica uneven film (on the side in contact with the polyvinyl butyral film) inside the glass plate is provided or not provided. However, the antireflection performance was almost unchanged.

[Examples 6 and 7] Blending ratio of hydrolyzed polycondensation solution of ethyl silicate, chain silica colloid (trade name: Snowtex OUP) and 2-propanol used in preparation of coating solution in Example 1 Was changed as shown in Table 8, and a coating liquid was prepared in the same manner as in Example 1. The coating liquid contained chain silica fine particles and ethyl silicate in a weight ratio shown in Table 8 in terms of silica.

Next, using this coating solution, the same glass plate as in Example 1 was applied, dried and heat-treated under the same conditions as in Example 1 to obtain a glass plate having a silica uneven film formed on both surfaces. Was. Example 1 The thickness of the obtained silica concavo-convex film, the refractive index of the film, the film porosity and the film surface roughness, and the visible light reflectance and visibility of the glass plate provided with the silica concavo-convex film were measured in Example 1.
Table 9 shows the results of the measurement in the same manner as described above.

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[Table 8] ================================= Hydrolysis of Ethyl Silicate Linear Silica 2-Fluorocondensation Polymerization solution Koroit® Phenol Chain-shaped fine particles: ethyl silicate (parts by weight) (parts by weight) (parts by weight) (weight ratio in terms of silica) −−−−−−−−−−−−−−−−−−−−−−− −−−−−−−−−−−−− Example 1 3.0 13.3 74.9 100: 15 Example 6 1.4 13.3 74.9 100: 7 Example 7 5.0 13.3 74.9 100: 25 =========== =======================

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[Table 9] =================================== Surface roughness Visible light reflectance (%) Visual film thickness Folded porosity (nm) −−−−−−−− Recognition (nm) Percentage (vol%) −−−−− Incident angle Incident angle Ra Sm 12 ° 60 ° −−−−−−−− −−−−−−−−−−−−−−−−−−−−−−−−−−− Example 6 115 1.28 70 10 22 0.7 1.95 Example 7 160 1.38 55 7 20 2.2 3.25 == ===============================

[0085]

According to the present invention, since the glass plate is coated with a layer having surface irregularities and a low refractive index, the visible light reflectance of the glass plate, particularly, the visible light reflection at a high incident angle of 60 degrees. The ratio (when coated on both surfaces of the glass plate) is as low as 4.0% or less, and the anti-glare effect is obtained by the surface unevenness, so that a glass plate suitable for automotive windows having excellent visibility can be obtained. .

Claims (13)

[Claims] At least one surface of a glass substrate is coated with a chain silica fine particle and a film having a thickness of 110 to 250 nm, which is composed of 5 to 30% by weight of silica based on the weight of the chain silica fine particle. A visible light anti-reflection glass plate having irregularities formed on the surface of the film. 2. A film made of chain silica fine particles and silica and having a thickness of 110 to 250 nm is coated on at least one of the glass substrate surfaces, and voids are formed between adjacent chain silica fine particles in the film. An anti-reflective glass plate which is formed and has a film having a refractive index of 1.25 to 1.40, and having irregularities formed on the film surface. 3. The chain silica fine particles have a particle size of 10 to 20 n.
3. The anti-reflective glass plate according to claim 1, having an average diameter of m and an average length of 60 to 200 nm. 4. The film according to claim 1, wherein the unevenness on the film surface has an arithmetic average roughness (Ra) of 5 to 50 nm and an average interval (Sm) of the unevenness of 10 to 300 nm. Anti-reflective glass plate. 5. The antireflection method according to claim 1, wherein a water-repellent film is further coated on the surface of the film and / or the surface of the glass substrate not coated with the film. Glass plate. 6. The reflection according to claim 1, wherein a surface of the film and / or a surface of the glass substrate on which the film is not coated are further coated with an antifogging film. Prevention glass plate. 7. Both surfaces of the glass substrate are coated with the film, and one surface of the glass substrate is coated with an anti-fog coating,
The anti-reflection glass plate according to any one of claims 1 to 4, wherein a water-repellent film is coated on the other film surface. 8. The glass substrate, wherein only one surface of the glass substrate is coated with the film, the surface of the film is coated with an anti-fogging film, and the other surface of the glass substrate is coated with a water repellent film. 5. The anti-reflection glass plate according to any one of items 4 to 4. 9. At least one member selected from the group consisting of (1) chain silica fine particles, and (2) a hydrolyzable / polycondensable organic silicon compound, a chlorosilyl group-containing silicon compound, and a hydrolyzate thereof. A method for producing an antireflection glass plate, comprising applying a liquid containing a silicon compound to a surface of a glass substrate and drying the liquid to form an uneven silica film on the surface of the glass substrate. 10. The liquid contains the chain silica fine particles and the silicon compound in an amount of 5 parts by weight based on 100 parts by weight of the chain silica fine particles in terms of SiO _2.
The method for producing an anti-reflection glass plate according to claim 9, wherein the content of the anti-reflection glass plate is from 30 to 30 parts by weight. 11. The liquid according to claim 9, wherein the liquid has the following composition.
Or the method for producing an antireflection glass plate according to item 10. Silicon compound 100 parts by weight Chain silica fine particles 100-800 parts by weight Water 4-150 parts by weight Acid catalyst 0.00001-5 parts by weight Dispersing aid 0.001-10 parts by weight Solvent 500-10000 parts by weight 12. After the coating and drying, 400 to 750
13. Heating at 5 [deg.] C. for 5 seconds to 5 hours.
13. The method for producing an antireflection glass plate according to the above item. 13. A coating composition for an antireflection film having the following composition. Silicon compound 100 parts by weight Chain silica fine particles 100-800 parts by weight Water 4-150 parts by weight Acid catalyst 0.00001-5 parts by weight Dispersing aid 0.001-10 parts by weight Solvent 500-10000 parts by weight