JPH08152501A - Reflection decreasing glass for vehicle - Google Patents

Abstract

PURPOSE: To obtain a glass which decreases reflection and less exhibits interference colors when used as a front windshield, and has improved safety and is friendly to man and environment, etc., by decreasing the reflection of a dashboard or its peripheral part and the glittering feel to the man and the environment with a high-durability thin film, thereby enhancing the driver's seeing- through property and preventing erroneous recognition, eyes' fatigue, etc. CONSTITUTION: This reflection decreasing glass for vehicle is formed by coating and laminating at least one side surface of a transparent glass substrate with thin-film layers 5, 6 of a refractive index 1.7 to 1.8 and film thickness 90 to 110nm as the first layer and a refractive index 1.4 to 1.5 and film thickness 105 to 130nm as a second layer. The reflectivity at which light is made incident at an incident angle 50 to 70 deg. to the perpendicular line of the front surface and is reflected is made lower by 4.5 to 6.5% than the reflectivity of the glass surface and the stimulus degree of the reflected light to the incident light of 50 to 70 deg. is reduced to <=18%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly shows a phenomenon of glare and glare on a windshield mounted on a dashboard or a peripheral portion thereof at a specific inclination angle when driving a vehicle or the like. The present invention relates to a reflection-reducing glass for a vehicle, which contributes to further improvement in safety by reducing the amount of light emitted from the vehicle and improving the visibility of the driver.

[0002]

2. Description of the Related Art Conventionally, various proposals have been made and implemented for low reflection glass and glass belonging to the category.
In particular, in window glass for vehicles, high-performance multi-function glass with various functionalities has been used in recent years, and it is safer not only for drivers and passengers in the vehicle but also for oncoming vehicles. Glasses having low reflectivity and performance belonging to the above category have been proposed, while glass having excellent properties, excellent habitability, and environmental friendliness has been more and more desired.

Particularly, in the conventional low reflection performance used for a windshield mounted at a specific inclination angle in an automobile window, the purpose is to reduce the reflected light from the front,
With respect to oblique incident light having an incident angle with the vertical line of the windshield surface (hereinafter referred to as a normal line) of, for example, 50 ° to 70 ° or more, its low reflection effect is halved or almost nonexistent. When the driver or the peripherals thereof are reflected on the windshield, the visibility of the foreground at the time of driving is reduced, and the safety is deteriorated.

On the other hand, for example, Japanese Patent Application Laid-Open No. 3-17601 describes a method for forming an antireflection coating, in which a coating of a reactive composition containing a light metal oxide precursor, a non-aqueous solvent, and water is used as a substrate. Light metal oxidation of the coating formed above and concentrated by heating for a sufficient time and exposing the concentrated coating to an atmosphere containing fluorine gas or a fluorine-producing gaseous compound at elevated temperature for a sufficient time. By substituting at least a part of the oxygen atoms of the product with fluorine atoms, a coating having a concentration gradient of light metal fluoride with respect to the thickness of the coating and exhibiting excellent antireflection performance for the entire visible light spectrum can be obtained. What is to be obtained is disclosed.

Further, for example, Japanese Unexamined Patent Publication No. 64-70701 discloses a transparent plate having a conductive antireflection film, which has a refractive index of 1.90 to 2.50 and a film thickness on a metal film for imparting conductivity. But
A high refractive index dielectric film having a refractive index of 200Å to 400Å and a low refractive index dielectric film having a refractive index of 1.35 to 1.50 and a film thickness of 700Å to 1200Å are disclosed on the surface.

Further, for example, as described in Japanese Patent Application Laid-Open No. 4-357134, which has been filed by the applicant of the present invention, as a reflection-reducing glass for a vehicle, the refractive index n ₁ = 1.8-from the glass surface side as the first layer.
Covering a thin film layer having a thickness of 1.9 and a film thickness of 700 to 900Å,
Then, on the first thin film layer, a second layer having a refractive index of
n ₂ = 1.4 to 1.5 and a film thickness of 1100 to 1300Å, which are laminated to form a film. It has been proposed that the reflectance of visible light on the laminated surface coated with the thin film is 4.5 to 6.5% lower than the reflectance on a glass surface not coated with the ordinary thin film.

[0007]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In the reflection reducing glass for vehicles described in, for example, Japanese Patent Application Laid-Open No. 4-357134 already proposed by the present applicant, a sufficient reflection reducing effect for obliquely incident light can be exhibited. However, the incident angle is 0-40
The stimulated purity of the reflected light exceeds 30% for the light of °, and the maximum is about 35%, and the stimulated purity of the reflected light exceeds 20% for the light of the incident angle of 50 to 70 °. Therefore, it was hard to say that the feeling of glaring was not necessarily low, such as the maximum being about 21%.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks of the prior art, and combines thin films having specified refractive indices and film thicknesses, and uses a simple two-layer thin film coating lamination, The visible light transmittance in the windshield
It meets 70% or more, and can reduce the reflectance of the reflected light at a predetermined oblique incident light by about 4.5 to 6.5%. Moreover, when viewed from the inside and outside of the vehicle, the glare of the reflected light is suppressed, and misidentification or discomfort can occur. The present invention provides a reflection-reducing glass for a vehicle, which does not develop.

That is, according to the present invention, at least one surface of the transparent glass substrate is coated with a thin film layer having a refractive index of n ₁ = 1.7 to 1.8 and a film thickness of 90 to 110 nm as the first layer from the glass surface side. Then, on the first thin film layer, as the second layer, the refractive index is n ₂ = 1.4 to 1.5 and the film thickness is 105 to 130n.
m is a thin film layer is coated and laminated, and further, with respect to visible light incident on the film surface side with an incident angle formed with the vertical line of the surface between 50 ° and 70 °, the reflectance at the thin film coated laminated surface It is 4.5 from the reflectance on the glass surface without the usual thin film coating.
The reflection-reducing glass for vehicles is characterized in that the stimulus purity of the reflected light with respect to the incident light of 50 to 70 ° is 18% or less.

In addition, the thin film of the first thin film layer is
The reflection-reducing glass for vehicles described above, which is composed of a mixture of two or more of SiO ₂ , TiO ₂ , ZrO ₂ , Al ₂ O ₃ and B ₂ O ₃ .

Further, of the thin film layers, the first thin film layer is a thin film having a molar ratio of TiO ₂ : SiO ₂ = 40: 60 to 55:45, and the second thin film layer is a SiO ₂ thin film. The reflection reducing glass for vehicles according to claim 1 is provided.

Here, the refractive index of the first layer is n ₁ = 1.7.
A thin film layer having a thickness of 90 to 110 nm and a second layer on the first layer and having a refractive index of n ₂ = 1.4 to 1.5 and a thickness of 105 to 130 nm. The reason why we decided to use two layers is that, for example, when a high refractive index thin film with a refractive index of 2.0 or more is used, coloring and reflection become stronger, and the visible light transmittance is 70% or more or the reduction of reflection is expected. However, as the thin film layer is formed into a multi-layer thin film layer with more than two layers, it becomes difficult to obtain sufficient durability performance for vehicles, and the manufacturing process becomes more complicated and economical. Because it will not be.

Further, unless the values of the refractive index and the film thickness of the first and second thin films are the values of the visible light on the film surface side, the incident angle with the vertical line of the surface is between 50 ° and 70 °. With respect to light, the reflectance on the laminated surface coated with the thin film is 4.5 to 6.5% than the reflectance on the glass surface without the ordinary thin film coating.
This is because it cannot be reduced.

The incident angle with the vertical line of the surface is 50.
With respect to the visible light incident on the film surface side in the range of ° to 70 °, the reflectance on the laminated surface of the thin film coating is 4.5 to 6.5% lower than the reflectance on the glass surface without the ordinary thin film coating. Generally, the mounting angle of the windshield of an automobile is about 40 ° to 20 °, and the dashboard and its peripheral portion are reflected on the inner surface of the windshield to cause a reflection phenomenon, which is not preferable for a driver or the like. This is because the incident angle of the light is 50 ° to 70 ° with respect to the vertical line of the surface. In addition, the reflectance is 4.5
If it is reduced by ~ 6.5%, it will be almost impossible for the driver etc. to see the projection and it will not be noticeable, and even if the current color tone of the dashboard is mainly black, The reason is that it becomes possible to change to a bright color tone, and it becomes possible to make the color richer in variety.

Furthermore, the reason why the stimulus purity of the reflected light with respect to the incident light of 50 to 70 ° is set to 18% or less is that the driver, of course, the environment of passengers and oncoming vehicles, especially people For example, the environment does not always look at the glass at an angle of 50 ° to 70 °, and it reduces glare when viewed from all directions, reduces eye and body fatigue, and eliminates unsafety due to them. , Because it is gentle from both human and physical aspects.

Further, for example, even if the film thickness of the first layer and the second layer is controlled by setting the refractive index of the first layer to 1.8 or more, the effect of reducing the reflection of obliquely incident light can be expected. However, the stimulus purity for light reflected at a low angle is, for example, for light with an incident angle of 0 to 40 °, the stimulus purity of the reflected light exceeds 30% to a maximum of about 35%. The stimulus purity of the reflected light for the light of 50-70 °
There is a portion that exceeds 20%, and the maximum is approximately 21%.
Since the glaring feeling cannot always be suppressed, the structure of the present invention reduces the reflection of visible light and reduces the glaring feeling from any direction.

Further, the thin film of the first thin film layer is Si
It is preferable to use a mixture of two or more kinds of O ₂ , TiO ₂ , ZrO ₂ , Al ₂ O ₃ and B ₂ O ₃ because TiO ₂ having a relatively high refractive index (about 2.25) , ZrO ₂ (about 1.95) and SiO ₂ (about 1.45), which has a relatively low refractive index, Al ₂ O ₃ (about 1.65), B ₂ O ₃ (about 1.60) can be freely mixed and mixed to mix. This is because it is easy to obtain a composite film having a controlled refractive index of 1.7 to 1.8 and excellent durability.

Furthermore, the first thin film layer is made to have a molar ratio of Ti.
O ₂ : SiO ₂ = 40: 60 to 55:45 is a thin film, and the second thin film layer is preferably a SiO ₂ thin film because the alkoxide is stable among the combinations of the above components. This is because the film forming property is good, a uniform film is easily obtained, the most excellent reflectance reduction effect is obtained, and the durability is high.

Further, the glass substrate may be either colorless or colored, as long as it is transparent glass, that is, for example, blue, bronze, gray or green glass, etc., especially in automobile window materials, it is blue or gold. It is more preferable that the color tone is a system color, a green color color, and particularly a gold color tone, which easily obtains the heat ray / ultraviolet absorption performance. It goes without saying that it can be used not only as a single plate, but also as a heat ray reflective glass, a multi-layered or laminated glass, a strengthened glass, a strength-up glass, a bent glass and the like. Furthermore, it goes without saying that the glass substrate may be inorganic or organic.

[0020]

As described above, the vehicle reflection-reducing glass of the present invention is a combination of a thin film having a medium refractive index from the glass surface side, then a thin film having a low refractive index, a specific refractive index, and a thin film having a predetermined film thickness, With a simple two-layer thin film coating lamination, the visible light transmittance in the windshield meets 70% or more, and, for example, 50 ° from the dashboard etc.
For obliquely incident light incident at 70 °, the reflectance of the reflected light on the glass inner surface is reduced by about 4.5 to 6.5%, and the stimulation purity of the reflected light for the incident light at 50 to 70 ° is 18%.
Since it is as follows, it is possible to suppress the glare when seen from the inside and outside of the car, improve the transparency due to the suppression of reflections, prevent misidentification and discomfort, and further enhance durability and the driver. It is a reflection-reducing glass for vehicles that is environmentally friendly to passengers and people and is useful as a window material for automobiles.

[0021]

The present invention will be described below in detail with reference to examples. However, the present invention is not limited to the embodiment.

Example 1 As shown in FIG. 1, first, a Ti alkoxide and a Si alkoxide were mixed at a molar ratio of 45:55, and a solvent such as isopropyl alcohol was added to the mixture to obtain a solute concentration of about 0.45 mol / l. 2
An alkoxide solution was prepared so as to have mPa · s, and then the outer surface side of the inner glass plate 3 was masked with a masking tape, and the inner glass plate 3 was immersed in the above-mentioned preparation solution,
After pulling up at a speed of 4.5 mm / sec, the masking tape was removed and the film was heated at about 270 ° C. for about 10 minutes to obtain the first thin film layer 5. Then, a masking tape is attached again to the non-membrane surface of the inner glass plate 3, and about 0.25 mol / l, about 7 mPa ·
After dipping in the Si alkoxide solution prepared in s,
The second thin film layer 6 was obtained by pulling up at a rate of 3.8 mm / sec, removing the masking tape, and heating at about 270 ° C. for about 10 minutes. Next, in the bending step, the inner glass plate 3 with a reflection reducing thin film is put in a bending and baking furnace, and is subjected to a bending heat treatment at about 620 ° C., and the bent inner glass plate 3 with a reflection reducing thin film and the bent outer glass plate A reflection-reducing glass 1 for a vehicle was obtained by using 2 and the intermediate film 4 to form a laminated glass in a laminating process.

In the obtained anti-reflection glass for vehicle 1 , the first thin film layer 5 on the glass surface side has a refractive index n ₁ = 1.75 and a film thickness of about 10
0 nm TiO ₂ · SiO ₂ thin film, _second thin film layer 6 has refractive index n ₂ =
It is a SiO ₂ thin film with a film thickness of about 118 nm at 1.45, and the reflectance of the reflected light 9 with respect to the incident visible light at an incident angle θ of about 65 ° between the vertical line 7 and the incident light 8 with respect to the film surface. Showed an effect of reducing by about 6%.

The stimulus purity of the vehicle reflection-reducing glass 1 having a two-sided single-sided film is such that the incident angle (°) of visible light and the stimulus purity of its reflected light ( %), As shown in FIG. 2, the stimulus purity of the reflected light is 26 with respect to the incident light with an angle of 0 to 40 °.
%, The stimulus purity of the reflected light was 18% or less with respect to the incident light having an angle of 50 to 70 °, which was excellent in suppressing glare.

Comparative Example 1 First, Ti alkoxide and Si alkoxide were mixed in a molar ratio of 5
Mix at 8:42 and add a solvent such as ethanol to this to prepare an alkoxide solution so that the solute concentration will be about 0.45 mol / l and about 1.5 mPa · s, and then cover the outer surface of the inner glass plate with a masking tape. After masking, the inner glass plate was immersed in the above-mentioned preparation liquid, pulled up at a speed of about 3.5 mm / sec, the masking tape was removed, and the film was heated at about 270 ° C. for about 10 minutes to obtain a first thin film layer. It was Then, reapply the masking tape to the non-membrane surface of the inner glass plate,
After dipping in a Si alkoxide solution prepared to a mol / l of about 7 mPa · s, pulling up at a rate of about 4 mm / sec, removing the masking tape, and heating at about 270 ° C for about 10 minutes, the second thin film Layers were obtained. Next, in the bending step, the inner glass plate with the reflection-reducing thin film was put in a bending and baking furnace to about 620
A reflection-reducing glass for a vehicle is obtained by performing a bending heat treatment at ℃, and further using the bent inner glass plate with a reflection-reducing thin film, the bent outer glass plate 2 and an intermediate film to form a laminated glass in a combining treatment step. It was

In the obtained antireflection glass for vehicles, the first thin film layer 5 on the glass surface side has a refractive index n ₁ = 1.85 and a film thickness of about 78 nm.
TiO ₂ · SiO ₂ thin film, the second thin film layer 6 has a refractive index n ₂ = 1.45.
Is a SiO ₂ thin film with a film thickness of about 122 nm, and the reflectance of the reflected light is about 6% with respect to the incident visible light at an incident angle θ of about 65 ° between the vertical line and the incident light. Although the effect of reducing the degree is shown, as shown in FIG.
The stimulus purity of the reflected light with respect to the incident light at 30 ° is 30% or more, which is as large as about 35% at the maximum, and the stimulus purity of the reflected light with respect to the incident light at 50 to 70 ° is about 21% at the maximum, which gives glare. It cannot be denied, and it was not the intended anti-reflection glass for vehicles.

[0027]

As described above, according to the present invention, a thin film having a specified refractive index and a specified film thickness is combined to achieve a simple structure.
The thin film coating of the layers satisfies the visible light transmittance of 70% or more on the windshield and reduces the reflectance of oblique incident light of 50 ° to 70 ° by about 4.5 to 6.5%.
By setting the stimulus purity of the reflected light for incident light of ~ 70 ° to 18% or less, the phenomenon of reflection on the dashboard or these peripheral parts is reduced, the driver's see-through property is improved, and false recognition is achieved. Alternatively, it improves safety by preventing eye fatigue, etc., and it is gentle to both human and physical environment with less glare from any direction, and also to the environment. In the above, it is possible to provide a useful reflection-reducing glass for vehicles.

[Brief description of drawings]

FIG. 1 is a partially enlarged side sectional view of a reflection reducing glass for a vehicle of the present invention.

FIG. 2 is a diagram showing the relationship between the incident angle (°) of visible light and the stimulus purity (%) of the reflected light in the vehicle reflection-reducing glass of the present invention.

[Explanation of Codes] 1 Vehicle anti-reflection glass 5 First layer thin film layer 6 Second layer thin film layer

Claims (3)

[Claims] 1. A transparent glass substrate having a refractive index of n ₁ = 1.7 to at least one surface as a first layer from the glass surface side.
A thin film layer having a thickness of 1.8 and a thickness of 90 to 110 nm is coated, and then a refractive index of n ₂ is applied as a second layer on the first thin film layer.
= 1.4 to 1.5 and a film thickness of 105 to 130 nm, and the visible light on the film surface side that is incident at an incident angle of 50 ° to 70 ° with the vertical line of the surface. As opposed to
The reflectance on the laminated surface coated with the thin film is reduced by 4.5 to 6.5% from the reflectance on the glass surface without the ordinary thin film coating, and the stimulation purity of the reflected light with respect to the incident light of 50 to 70 ° is set to 18% or less. A reflection-reducing glass for vehicles, characterized by comprising 2. The thin film of the first thin film layer is SiO ₂ , Ti
_{O 2, ZrO 2, Al 2} O 3, B 2 vehicle reflection reducing glass according to claim 1, characterized in that it consists of a mixture of two or more of the O _3. 3. A thin film having a molar ratio of TiO ₂ : SiO ₂ = 40: 60 to 55:45 in the first thin film layer among the thin film layers,
The reflection-reducing glass for vehicles according to claim 1, wherein the _second thin film layer is a SiO ₂ thin film.