JP2000256040A - Glass panel for automobile window - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a glass panel having a low reflectance of visible light and improved in visibility by coating at least one side of the surfaces of a glass substrate having the visible light transmittance equal to or below a specific value with a film composed of chain silica fine particles and silica in a specific ratio by weight to the chain silica fine particles and having a rugged surface and a specific film thickness. SOLUTION: The glass panel for automobile window is formed by coating at least one of the surfaces of the glass substrate having <=50% visible light transmittance with the film composed of chain silica fine particles and 5-30 wt.% silica to the chain silica fine particles and having the rugged surface and 110-250 nm film thickness. The film is formed by applying a liquid containing the chain silica fine particles and a hydrolyzable silica compound on the glass substrate. The refractive index of the film becomes 1.25-1.40 because voids are generated among the chain silica particles in the film. The size of the chain silica fine particles is 10-20 nm in average diameter and 60-200 nm in average length.

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 for an automobile window having a small visible light reflectance.

[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 glass article surface. 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 side window glass and a back window glass of an automobile, reflected light from an instrument panel, a dashboard, and the like in the vehicle, and light from an interior light, a light-emitting display panel, an illumination light of an audio device, and the like are used for the side window glass and the back window glass. Reflected on the surface of the vehicle, directly or through the interior reflector, enters the driver's field of view, causing glare, which reduces the driver's lateral and rear visibility. Further, there is a problem that the light reflected on the side window glass and the back window glass is reflected on the windshield directly or after being reflected on the in-vehicle components, and is reflected, so that the visibility in the front is reduced. In particular, when a so-called privacy glass, that is, a colored glass plate having a visible light transmittance (Ya) of 50% or less is used as the side window glass and the back window glass, the amount of light that enters the driver's eyes from outside the vehicle decreases. , Visibility is likely to decrease significantly.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a glass plate having a small visible light reflectance and an improved visibility and suitable for an automobile window.

[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 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 glass substrate surfaces having a visible light transmittance (Ya) of 50% or less, and the film surface has irregularities. It is a formed glass sheet for an automobile window.

The present invention also provides a film comprising a chain of silica fine particles and silica and having a thickness of 110 to 250 nm coated on at least one of the surfaces of a glass substrate having a visible light transmittance (Ya) of 50% or less. An automobile in which voids are formed between adjacent chain-like silica fine particles in the film, the film has a refractive index of 1.25 to 1.40, and irregularities are formed on the film surface. It is a glass plate for windows.

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 the same weight of spherical silica fine particles were used instead of chain silica fine particles. In addition, 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 was increased relative to the chain silica fine particles, and the volume of the entire film was calculated from the difference between the refractive index (about 1.45) of the film in which the gaps between the chain silica fine particles were 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. The average diameter is 20n
If the average length exceeds 200 nm or the average length exceeds 200 nm, the arithmetic average roughness (Ra) of the film surface becomes larger than 50 nm,
Undesirably, haze is likely to occur and the resolution of the perspective image is likely to be reduced, and visibility is reduced.

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)

For example, the film thickness (d) at which the visible light reflectance at an incident angle of 12 degrees is minimized is represented by α = 12 and m =
It is obtained by substituting 0. The film having the refractive index n is 3 in the visible light range.
If the thickness (d) of the following formula is satisfied at any wavelength λ of 80 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 made of chain silica fine particles and silica in the present invention is 1.
Since it is 25 to 1.40, the film thickness at which the visible light reflectance is minimum is 82 to 168 nm from the above equation (1). 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. Therefore, the film thickness of this definition is as large as the arithmetic average roughness (Ra) of the film surface as compared with the film thickness of the above formula 1, so that the film thickness in the present invention is actually 106 to 202 nm. Preferably, there is.

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 to face a medium having a refractive index close to 1 such as air or gas, a higher anti-reflection effect can be obtained by forming this film on both surfaces of the glass substrate. 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 may be easily mixed with the solution containing the organometallic compound, and may 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 hydrolyzable and polycondensable organic silicon compound or the 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 organosilicon compound to be contained in the liquid 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,
Substituting at least two hydrogen atoms in silane Si _n H _{2n + 2} (where n is an integer of 1 to 5) with chlorine, and replacing other hydrogen atoms with the above alkyl group, alkoxy group, or acyloxy group as necessary 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 therein, but alcohols such as methanol, ethanol, propanol and butanol, ethyl cellosolve , 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 becomes impossible 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 acidic or neutral, but in order to promote hydrolysis, it is preferable to use water acidified with hydrochloric acid, nitric acid, sulfuric acid, acetic acid, citric acid, sulfonic acid or the like. 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 as a mixture. 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 chain silica fine 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 hydrolyzate of an organic metal compound 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,
A glass plate such as a rear window, front door, or rear door for an automobile that has completed the bending and laminating steps may be used, and the glass before the laminating step, before the bending step, or before being cut to a predetermined size. It may be a plate. The glass substrate has a thickness of 1.5
It has a thickness of about 6.0 mm and a visible light transmittance (Ya) of 50% or less, and usually has a visible light transmittance (Ya) of 10% or more.
Those having a) are 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).
If only one surface of the glass plate is coated with the silica uneven film, it is more effective to prevent the visible light from being reflected by directing the surface coated with the silica uneven film toward the inside 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 colored glass plate having a soda lime silicate composition (visible light transmittance (Ya)), 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.
36.7%, visible light reflectance 4.8%, size 65mm x 1
50 mm × 4 mm, “sundym”, manufactured by Libby Owens Ford), one surface of which is covered and sealed with a masking tape, immersed in the coating solution for forming a low refractive index uneven layer, and the speed of 20 cm / min. The coating solution was applied on one surface of the glass plate by pulling up. The glass plate was dried at 100 ° C. for 30 minutes, further dried at 250 ° C. for 30 minutes, and then dried at 500 ° C.
Heat treatment was performed in an oven for 1 hour to obtain a glass plate having a 140 nm-thick silica uneven film formed on each surface.

The thickness of the silica uneven film, the refractive index of the film, the film porosity and the film surface roughness, the visible light transmittance (Ya) of the glass plate with the silica uneven film, the visible light reflectance on the silica uneven film side, and The visibility was 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 an incident angle of 12 degrees was measured by using a spectrophotometer (MCPD-1000, manufactured by Otsuka Electronics Co., Ltd.) to measure the unevenness of silica on a glass plate. The reflected light projected from the side of the film was measured.

Visible light transmittance (Ya): Measured by the method specified in JIS R 3106 using the above spectrophotometer.

Visibility: A colored glass plate with an uneven silica film is placed on one side (right half) of the back window glass of the car so that the silica uneven film surface is on the inside of the car, and the other side (left half) is untreated. When assembling the colored glass plates and looking from the driver's seat to the rear of the vehicle with the interior reflector,
The sensory evaluation was conducted by comparing the left and right glass plates to see how easily the scenery behind was visible, that is, the degree of obstruction of the view due to the reflection of parts inside the vehicle. The evaluation criteria were based on the criteria shown in Table 2 below, in 1 to 5 stages. Table 3 shows the measurement results.

[0051]

[Table 2] ================================== Visibility Sensory Evaluation Criteria Score Criteria ---- −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− 1: Parts of the interior of the vehicle are worried, and the rear view is difficult to see. 2: The car interior parts are slightly anxious, but if you look carefully, you can see the rear view. 3: There is a little reflection of parts inside the car, but the scenery behind is easily visible. 4: There is almost no reflection of parts inside the vehicle, and the rear view is almost clear. 5: The rear scenery is clearly visible without any reflection of the parts inside the vehicle. ===================================

Comparative Example 1 Table 3 shows the measurement results of the visible light transmittance (Ya), the visible light reflectance, and the visibility of the same colored glass plate (untreated) used in Example 1.

[0053]

[Table 3] ================================== Surface Roughness Visible Light Visible Light Visual Thickness Folding Porosity (nm) Transmittance Reflectance (%) Approval (nm) Rate (Volume%)-----(Ya%) (incident angle 12 degrees) Property Ra Sm-------------- ---------------------Example 1 140 1.340 60 7 20 37.2 2.9 4 Comparative Example 1-----36.7 4.9 1 Example 2 140 1.342 60 5 15 24.2 3.0 4 Comparative Example 2 − − − − − − 23.1 5.1 1 ===================================

Example 2 The soda lime silicate glass plate (65 mm × 150 mm × 3 m) used in Example 1 was used.
m) in place of another soda-lime silicate glass composition for automotive back window colored glass plates (visible light transmission (Ya) 23.1%, visible light reflectance 5.1%, dimensions approx. 150 cm × approx. 60cm x 3.5mm, "galaxse
e ", manufactured by Libby Owens Ford)
After dip coating and drying in the same manner as in Example 1, heat treatment is performed by a known bending step (heating at 570 ° C. for 15 minutes) to form a glass plate for an automobile back window glass having a 140 nm thick silica uneven film formed on one surface. Was manufactured.

For this glass plate, the thickness of the uneven film, the refractive index of the film, the film porosity, the film surface roughness, and the visible light transmittance (Y
a), when the visible light reflectance and the visibility were measured,
The results shown in Table 3 were obtained. The strength of the film was determined using a cotton cloth with a commercially available glass cleaner.
After rubbing 100 times while applying a load of 0 gf,
The film was observed with the naked eye to check for abnormalities, and this was counted once and repeated to conduct a test. In the first embodiment, 300
Abnormality was shown by rubbing the number of times, but in Example 2, no abnormality was shown up to 5,000 rubbing times. This glass plate exhibited visible light transmittance (Ya), visible light reflectance, and visibility as shown in Table 3.

Comparative Example 2 Table 3 shows the measurement results of the visible light transmittance (Ya), the visible light reflectance, and the visibility of the same colored glass plate (untreated) used in Example 3.

Example 3 Thermometer, Stirrer and Cooler
In a 1 liter glass reactor equipped with ₈F₁₇
CH_TwoCH_TwoSi (OCH_Three)_Three Containing a perfluoro group
10.0 g of an organosilicon compound having the following chemical formula 1
Hydrolyzable group-containing methylpolysiloxane compound 10.0
g, t-butanol 360.0 g, and 0.1 N salt
1.94 g of an aqueous acid solution was charged and co-hydrolyzed at 80 ° C. for 5 hours.
And n-hexane 1 which is a hydrophobic solvent
60.0 g was added and the mixture was stirred at room temperature for 10 hours.

[0058]

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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.

[0060]

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On the surface of the glass plate coated with the silica uneven layer obtained in Example 1 opposite to the uneven layer, 0.1 ml of the above-mentioned composition for forming a water-repellent film was applied 10 times with a cotton cloth, and excess was made with a dry cloth. And then heat-treated at 100 ° C. for 10 minutes to form a low-reflection water-repellent glass plate having a water-repellent film having a film thickness of 40 nm (laminated in the order of water-repellent coating-colored glass plate-silica uneven film). Obtained. 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.

[0064]

[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.

In substantially the same manner as in Example 1, a glass plate coated on both sides with a silica uneven layer was ultrasonically washed in pure water, dried, immersed in the organosilane coating solution, and immersed in 5 cm / The solution was applied on both surfaces of the glass plate with a silica uneven film by pulling up at a speed of one minute. 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 porous silica uneven film (anti-fogging film-silica uneven film-colored glass plate-silica uneven film-anti-fogging film laminated in this order) was obtained.

With respect to this low-reflection anti-fog glass plate, the visible light reflectance was measured by irradiating light, and the visibility was measured. The visible light reflectance was about 1.6%, and the visibility was low. A result of 5 was obtained. Further, the glass plate having the antifogging silica uneven film was subjected to surface roughness measurement, contact angle measurement, and initial and repeated antifogging evaluation by the following methods. As shown in Table 5, these measurement results showed that the composition had excellent antifogging performance, hardly adsorbed dirt, and had good antifogging maintenance and antifouling performance.

[0068]

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

Measurement of Surface Roughness and Contact Angle For the glass plate on which the above-mentioned organosilane-coated silica uneven film was formed, the arithmetic average roughness (Ra) and the average interval of unevenness (Sm) were determined using the silica unevenness film of Example 1. Was determined in the same manner as the measurement for 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.

[0071]

[Table 6]

Repeated evaluation of anti-fogging 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 glasses”, the back surface of the sample was brought into contact with cooling water, and the sample temperature was lowered. 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 repetition operation, a test chart for judging the perspective distortion printed on the plastic plate is attached to the back surface of the cooling device, water is allowed to penetrate into the gap between the plate and the back surface of the cooling device, and the perspective distortion judgment is performed from the sample side. Test chart was made observable. 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, and the state of occurrence of fogging and perspective distortion was examined using the above-described perspective distortion determination test chart.

[0074]

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 whole is fogged ========================== ======== Perspective Distortion Evaluation Perspective Distortion State −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− 5 No distortion 4 It is difficult to separate 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 ===================================== ====

Fifth Embodiment In substantially the same manner as in the second embodiment, the obtained 140 nm-thick silica concavo-convex film is formed on the inner surface of the glass plate for an automobile back window glass formed on both surfaces. After gravure coating the organosilane coating solution used in step 4 with a solution to which an appropriate amount of a viscosity modifier has been added, dry and heat-treat at 120 ° C. for 30 minutes, cool to room temperature, and lightly wash with pure water. An organosilane antifogging layer having a thickness of about 8 nm containing an ethylene oxide group in the molecule was coated on the inside.

Next, the glass plate was coated 10 times with a cotton cloth to which 1.0 ml of the composition for forming a water-repellent film 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, a glass sheet for an automobile back window glass was obtained in which the water-repellent coating, the silica concavo-convex film, the glass plate, the silica concavo-convex film, and the anti-fog film were laminated in this order from the outside of the vehicle.

The antifogging 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.

[0079]

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 from the film surface side of the glass plate is 3. 2%
Since the anti-glare effect can be obtained due to the unevenness of the surface, a glass plate having excellent visibility and suitable for an automobile window can be obtained.

Claims (8)

[Claims] 1. A film made of chain silica fine particles and 5 to 30% by weight of silica based on the weight of the chain silica fine particles and having a thickness of 110 to 250 nm has a visible light transmittance (Ya) of 50% or less. A) a glass plate for an automobile window, which is coated on at least one of the surfaces of a glass substrate having the above-mentioned structure, and has irregularities formed on the film surface. 2. A film comprising 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 a glass substrate having a visible light transmittance (Ya) of 50% or less. Voids are formed between the chain-like silica fine particles adjacent to each other in the inside, and the film is formed as follows.
An automotive window glass plate having a refractive index of 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 glass sheet for an automobile window 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. Glass plate for automobile windows. 5. The vehicle window according to claim 1, wherein a water-repellent film is further coated on a surface of the film and / or a surface of the glass substrate not coated with the film. For glass plate. 6. The automobile according to claim 1, wherein a surface of said film and / or a surface of said glass substrate not coated with said film are further coated with an anti-fogging film. Glass plate for windows. 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 glass sheet for an automobile window 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. The glass sheet for an automobile window according to any one of claims 1 to 4.