JP3678043B2 - Low reflection glass articles for automobiles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a low reflection glass article, and more particularly to an automotive glass article having a low visible light reflectance.
[0002]
[Prior art]
  Conventionally, the surface of a glass article has been subjected to an antireflection treatment in order to prevent visible light from being reflected on the surface of the glass plate or other glass article to reduce the transparency, light transmittance, or dazzle. It has been broken.
[0003]
  For example, (1) RBMuchmore, J.Opt, Soc, Amer., 1948,38,20-26 describes an optical multilayer film comprising a high refractive index film layer and a low refractive index film layer on a glass substrate. Has been described.
[0004]
(2) JP-A-4-357134GazetteThe first layer from the glass surface has a refractive index of 1.8 to 1.9 and a film thickness of 70 to 90 nm, and the second layer is a thin film layer having a refractive index of 1.4 to 1.5 and a film thickness of 110 to 130 nm. Covered and laminated, the reflectivity incident and reflected at an incident angle of 50 to 70 degrees with respect to the vertical line of the surface was reduced by 4.5 to 6.5% compared to the reflectivity of the glass surface. A vehicle reflection reducing glass is disclosed.
[0005]
(3) JP-A-8-152501GazetteThe first layer from the glass surface has a refractive index of 1.7 to 1.8 and a film thickness of 90 to 110 nm, and the second layer has a refractive index of 1.4 to 1.5 and a film thickness of 105 to 130 nm. The coating layer is laminated, and the reflectance that is incident and reflected at an incident angle of 50 to 70 degrees with respect to the vertical line of the surface is reduced by 4.5 to 6.5% compared to the reflectance of the glass surface, Moreover, a vehicle reflection-reducing glass is disclosed in which the stimulation purity of the reflected light with respect to the incident light of 50 to 70 degrees is 18% or less.
[0006]
[Problems to be solved by the invention]
  For (1) above, the refractive index n₀= 1.52 on a glass substrate with a refractive index n₁Layer of high refractive index film and refractive index n₂An optical thin film in which layers of low refractive index films are stacked is described. As a layer of a low refractive index film, n₂= 1.38 MgF₂And the refractive index of air is n_Three= 1, n₁The optimal value of,
[Expression 1]
    n₁= [(N₂)²× n₀/ N_Three]^1/2
n ₁ =1.70Get.However, this MgF₂Has a problem that it has poor environmental resistance and cannot be applied to the bending and firing process of automotive glass.
[0007]
  As for the above (2), SiO is used as a low refractive index film layer.₂Therefore, it has excellent environmental resistance and can be applied to the bending and baking process of automotive glass.Above formulaOptimal value n₁= 1.79 (n₂= 1.45), n₁= 1.80 to 1.90 high refractive index film layerTheSince the thickness is set to 70 to 90 nm, there is a problem that the stimulation purity of the reflected light increases when the reflectance is lowered.
[0008]
  For (3) above, the refractive index of the high refractive index film is set to n.₁= 1.70 to 1.80, and the reduction of reflectance for incident light of 50 to 70 degrees and the stimulation purity of reflected light are improved to 18% or less, but the film thickness is not optimized Therefore, the reduction of the reflectance with respect to incident light of 0 to 20 degrees is insufficient, and the value of the stimulation purity of the reflected light remains large.
[0009]
  The present invention,For automobiles with improved visibility by reducing reflectivity at high incident angles and stimulus purity of reflected light, and at the same time reducing reflectivity at low incident angles and stimulus purity of reflected light.Low reflectionAn object is to provide a glass article.
[0010]
[Means for Solving the Problems]
  The present inventionInvention of Claim 1Is the refractive index (n of the first layer film counted from the glass surface side) on at least one surface of the transparent glass substrate.₁) Is 1.65 to 2.20, and the film thickness is 110 to 150 nm.Coated withNext, a refractive index (n₂) Is 1.40~ 1.47And the film thickness is 81 to 100 nm.Substantially SiO ₂ Consist only ofLow reflection for automobiles having a stimulus purity of 22% or less and 10% or less of reflected light when visible light is incident at an incident angle of 12 degrees and 60 degrees from the film surface side, respectively. It is a glass article.
[0011]
  According to the third aspect of the present invention, the refractive index of the first layer film (n) counted from the glass surface side on at least one surface of the transparent glass substrate. ₁ ) Is 1.65 to 2.20, and a thin film layer having a film thickness of 110 to 150 nm is coated, and then a refractive index (n ₂ ) Is 1.40 to 1.49 and the film thickness is 81 to 100 nm. ₂ As the main component and B ₂ O _Three And / or Al ₂ O _Three A vehicle having a stimulus purity of 22% or less and 10% or less of reflected light when visible light is incident at an incident angle of 12 degrees and 60 degrees from the film surface side, respectively. It is a low reflection glass article for use.
0012]
  In the present invention, the first layer has a refractive index (n₁) Is 1.65 to 2.20 and the film thickness is 110 to 150 nm because the refractive index n₁When the value is larger than 2.20, the reflectance at a specific wavelength is lowered. However, when viewed in the entire visible range, coloring and reflection become strong, and the visible light transmittance becomes 70% or less, and a desired reflection reduction effect is obtained. It is because it is not possible.
0013]
  Refractive index n of the first layer₁Is less than 1.65, the value of the stimulation purity of the reflected light can be reduced, but a sufficient effect of reducing the reflected light intensity cannot be obtained for incident light ranging from a high incident angle to a low incident angle. A preferable range of the refractive index of the high refractive index film of the first layer is 1.67 to 1.80. Moreover, if the thickness of the first layer film is smaller than 110 nm, the reflectance and the stimulation purity of the reflected light at a low incident angle increase, and if it exceeds 150 nm, the stimulation purity at either the high or low incident angle increases.
0014]
  The second layer,In the inventions according to claims 1 and 2 of the present invention, substantially SiO 2 ₂ In the invention according to claim 3 of the present invention, the layer of the low refractive index film is substantially made of SiO. ₂ With B as the main component ₂ O _Three And / or Al ₂ O _Three Including onlyThe layer of low refractive index film isSiO ₂ This is because they are excellent in chemical stability, thermal stability and mechanical strength. The second layerSiO ₂ Is the main component.Like the invention according to claim 3,B₂O_Three, Al₂O_ThreeThe total of such oxides may be 15 mol% or less.
0015]
  Refractive index of the second layer (n ₂ ) Is 1.40 to 1.47 in the invention according to claim 1 or 2 of the present invention, or 1.40 to 1.47 in the invention according to claim 3 of the present invention.1.49It was. The lower limit is 1.40 because SiO ₂ Has a refractive index of 1.45.degreeIn Although,SiO ₂ Forming minute irregularities on the surface of the film, SiO ₂ The inside of the membrane is porous with independent foam or through-poresBy doingThe apparent refractive index may be lowered, or the refractive index may be lowered by adding inorganic fine particles having a low refractive index.Is from. By making the refractive index smaller than 1.45, the reflection reduction effect is increased.
  However,If the apparent refractive index of the thin film is made smaller than 1.37, the density of the film is reduced or the uneven shape of the surface is increased, resulting in poor wear resistance, chemical resistance, antifouling property, weather resistance, etc. Become. When the refractive index exceeds 1.49, a desired reflection reduction effect cannot be obtained.Substantially SiO ₂ Consist ofPreferred refractive index of the second layer (n₂) Is 1.40 to 1.47.
  In the invention according to claims 1 to 3 of the present invention, the thickness of the second layer film,81-100nmIt was. this is,When the thickness of the second film having a low refractive index is larger than 100 nm, the reflectance at a low incident angle and the stimulation purity of the reflected light are increased, and when the thickness is smaller than 81 nm, the intensity of the reflected light cannot be sufficiently reduced.Is from.
0016]
  The thin film of the first thin film layer is SiO.₂And TiO₂It is preferable to contain. TiO with relatively high refractive index₂(About 2.25) and,SiO with a relatively low refractive index₂(About 1.45) can be mixed in various combinations to obtain a composite film that can be freely controlled to have a refractive index of 1.65 to 2.20.YouAnd excellent durability. As other ingredients, ZrO₂(Refractive index:1.95), CeO₂, BiO_ThreeEtc., 10 in totalmass% AmountTheIt may be added. The first thin film layer is made of TiO in molar ratio.₂: SiO₂= 35: 65-60: 40, and the second thin film layer is SiO₂A thin film is preferable. Among the combinations of the above components, TiO₂And SiO₂Has a stable alkoxide and good film formability, and a homogeneous film can be obtained.YouIn addition, the most excellent reflectance reduction effect can be obtained and high durability can be obtained.
0017]
  Furthermore, the glass substrate may be colorless or colored as long as it is transparent glass, that is, for example, green, bronze, gray, high performance UV cut green glass, high performance UV cut bronze glass, etc. It is more preferable if the material is a green color, especially if it is easy to obtain heat ray / ultraviolet absorption performance. In addition to being able to be used as a single plate, laminated glass, heat ray reflective glass, multiple layers orIs strongNeedless to say, it can be used as a vitrified glass, a bent glass, or the like. Usually, a glass having a thickness of 1.5 to 6.5 m (in the case of laminated glass or multilayer glass, the distance between the outer surfaces) is used.
0018]
  As a method for forming the high refractive index film and the low refractive index film of the present invention, it can be formed by a sputtering method or a CVD method, but the sol-gel method is more preferable from the viewpoint of cost. For coating by the sol-gel method, spin coating, dip coating, meniscus coating, flow coating, roll coating, gravure coating, flexographic printing, screen printing, and the like are used.
0019]
  When an optical thin film containing, for example, titanium oxide and silicon oxide is formed on the high refractive index film and low refractive index film of the present invention by a sol-gel method, the coating liquid composition contains a titanium compound, a silicon compound, and It consists of a solvent and is obtained by mixing a titanium compound and a silicon compound in an organic solvent.
0020]
  As the titanium compound, titanium alkoxide, titanium alkoxide chloride, titanium chelate or the like is used. Titanium methoxide, titanium ethoxide, titanium as titanium alkoxide−n-propoxide, titanium−n-butoxide, titanium isobutoxide, titanium methoxypropoxide, titanium stearyl oxide, titanium−Examples thereof include 2-ethylhexoxide. As titanium alkoxide chloride,Examples thereof include titanium chloride triisopropoxide and titanium dichloride diethoxide. Titanium chelate products include titanium triisopropoxaside (2,4-pentandionate), titanium diisopropoxide (bis-2,4-pentandionate), titanium allyl acetate triisopropoxide, titanium bis (tri Ethanolamine) diisopropoxide, titanium−Di-n-butoxide (bis-2,4-pentanedionate) and the like are used.
0021]
  As a silicon compound,Silicon alkoxide is mixed with a solvent such as alcohol, and hydrolyzed and polymerized with an acidic or basic catalyst. As silicon alkoxide,Silicon methoxide, silicon ethoxide or oligomers thereof are used.
0022]
  Boron methoxide, boron ethoxide, boron as boron compounds to be included in addition to silicon compounds as the coating liquid composition for the low refractive index film−n-propoxide, boron−i-propoxide, boron−n-butoxide, boron−s-butoxide, boron−t-Butoxide and these chelating compounds are used.
0023]
  Examples of the aluminum compound added as the coating liquid composition for the low refractive index film include aluminum methoxide, aluminum ethoxide, and aluminum.−n-propoxide, aluminum−i-propoxide, aluminum−n-butoxide, aluminum−s-butoxide, aluminum−t-Butoxide and these chelating compounds are used. Examples of the chelate compound include aluminum (di-s-butoxide) ethyl acetoacetonate, aluminum (s-butoxide) bisethyl acetoacetonate, aluminum (di-−i-propoxide) ethyl acetoacetonate and the like are conveniently used.
0024]
  As the acid catalyst, hydrochloric acid, sulfuric acid, nitric acid, hydrochloric acid, acetic acid, oxalic acid, trichloroacetic acid, trifluoroacetic acid, phosphoric acid, hydrofluoric acid, formic acid and the like are used. As the basic catalyst, ammonia and amines are used.
0025]
  The organic solvent used in the coating liquid composition used for forming the high refractive index film and the low refractive index film depends on the coating method, but methanol, ethanol, isopropanol, butanol, hexanol, octanol, 2-methoxyethanol, Examples include 2-ethoxyethanol, 2-butoxyethanol, cellosolve acetate, diethylene glycol monoethyl ether, hexylene glycol, diethylene glycol, tripropylene glycol, and diacetone alcohol.
0026]
  Coating liquid composition is,To adjust the viscosity, surface tension, etc.,You may use two or more. Moreover, you may add a stabilizer, a leveling agent, a thickener, etc. in small quantities as needed. The amount of solvent used is,Although it depends on the film thicknesses of the finally obtained high refractive index film and low refractive index film and the coating method employed, it is usually used so that the total solid content falls within the range of 1 to 20%.
0027]
  After applying the coating liquid composition by the above application method, drying and / or heating and baking at a temperature of 250 ° C. or higher, and repeating the step of applying the next coating liquid,A low reflection glass article is completed. The film thus obtained has excellent performance such as transparency, environmental resistance, and scratch resistance, and the process of densifying the layers of the high-refractive index film and the low-refractive index film even when stacked. The film peeling and the generation of cracks that are likely to occur due to the difference in the heat shrinkage rate in the film can be suppressed.
0028]
  Instead of the manufacturing method using drying / firing by heating above 250 ° C.,The light irradiation method described below can also be used. That is, after the coating liquid composition is applied by the application method, the coating film is subjected to a step of irradiating the coating film with an electromagnetic wave having a wavelength shorter than that of visible light, and then the subsequent coating liquid is applied. This is a method of repeating the drying step. Examples of electromagnetic waves having a wavelength shorter than visible light include γ-rays, X-rays, and ultraviolet rays. However, ultraviolet irradiation is preferable from the viewpoint of practicality on an apparatus in consideration of irradiation to a substrate having a large area. As an ultraviolet light source,Excimer lamps, low-pressure mercury lamps, high-pressure mercury lamps, metal halide lamps, etc. are used. Using a high-pressure mercury lamp that emits light at 254 nm and 303 nm efficiently with a main wavelength of 365 nm, 10 mW / cm²Or more, preferably 50 mW / cm²More preferably,100 mW / cm²It is desirable to irradiate the coating film with the above irradiation intensity. Using such an ultraviolet light source, 100 mJ / cm²Or more, preferably 500 mJ / cm²More preferably,1000mJ / cm²By applying the above irradiation energy to the coating surface applied using the coating liquid composition of the present invention, it is excellent in performance such as transparency, environmental resistance and scratch resistance at low temperatures, and is less prone to cracking. A laminated film is provided.
0029]
  Also,While irradiating with ultraviolet rays,You may perform drying and / or baking by heat simultaneously. By simultaneously using a drying method by ultraviolet irradiation and a drying step preferably by heat drying at a temperature of 250 ° C. or less, a coating film having excellent performance such as transparency, environmental resistance, and scratch resistance is provided, and lamination is performed. Even if they are overlapped, it is possible to suppress film peeling and crack generation that are likely to occur due to the difference in thermal shrinkage in the process of densification of the high refractive index film layer and the low refractive index film layer. By using ultraviolet irradiation in this way, the drying process can be speeded up and productivity can be dramatically improved.
0030]
DETAILED DESCRIPTION OF THE INVENTION
  Examples of the present invention will be described below, but the present invention is not limited to these examples.
0031]
  [Preparation of coating liquid composition]
  Liquid A: 500 g of ethyl silicate 40 was mixed with 440 g of ethyl cellosolve,60 g of 0.1 mol / l hydrochloric acidAnd then hydrolyzed. The mixture was stirred at room temperature for 2 hours and allowed to stand.
  Liquid B: 65.5 g of titanium tetraisopropoxide and 46.1 g of acetylacetone were mixed and stirred at room temperature.
  Liquid D1: 100 g of boron (n-butoxide) was added to 51 g of ethylSEMixed with rosolve.
  Liquid D2: 100 g of aluminum (69 g of di-s-butoxide ethyl acetoacetateSEMixed with rosolve.
0032]
    [Examples 1 to 12, Comparative Examples 1 and 2]
  [Preparation of coating solution for forming a high refractive index film]
  The liquid A, liquid B and ethanol (solvent) were mixed in the proportions shown in Table 1 to prepare coating liquids C1 to C10 for forming a high refractive index film used in Examples 1 to 12 and Comparative Example 1. The composition of these solutions is shown in Table 2.
0033]
  [Preparation of coating solution for forming low refractive index film]
  The liquid A, liquid D1, liquid D2 and ethanol (solvent) were mixed at the ratio shown in Table 3 to prepare coating liquids A1 to A3 for forming a low refractive index film used in Examples 1 to 12 and Comparative Example 1. did.
0034]
[Table 1]
============================
High refractive index film A liquid B liquid Solvent
Coating solution for forming (g) (g) (g)
---------------------------
      C1 solution 4.2 4.6 11.2
      C2 liquid 4.0 4.8 11.2
      C3 liquid 3.8 5.1 11.1
      C4 liquid 3.4 5.5 11.0
      C5 liquid 3.0 6.0 11.0
      C6 liquid 2.7 6.5 10.9
      C7 solution 4.2 4.6 11.2
      C8 liquid 2.0 7.3 10.7
      C9 solution 1.6 7.8 10.6
      C10 solution 0.9 8.6 10.5
============================
0035]
[Table 2]
==============================
High refractive index film Solid content SiO₂         TiO₂
Coating solution for forming (wt%) (mol%) (mol%)
------------------------------
      C1 liquid 8 60.0 40.0
      C2 liquid 8 57.5 42.5
      C3 liquid 8 55.0 45.0
      C4 liquid 8 50.0 50.0
      C5 liquid 8 45.0 55.0
      C6 liquid 8 40.0 60.0
      C7 solution 8 60.0 40.0
      C8 liquid 8 30.0 70.0
      C9 solution 8 25.0 75.0
      C10 liquid 8 15.0 85.0
==============================
0036]
[Table 3]
==================================
Low refractive index film A liquid D1 liquid D2 liquid Solvent solid content
Coating solution for forming (g) (g) (g) (g) (% by weight)
----------------------------------
  A1 liquid 5--15 5
  A2 liquid 4.5 0.5 -15 5
  A3 liquid 4.5-0.5 15 5
==================================
0037]
  Table 4 shows the surface of one side of an uncolored soda-lime silicate glass plate (100 mm x 100 mm x 2.1 mm) that has been surface-polished and washed with a cerium oxide-based abrasive and then ultrasonically washed in pure water. As shown, 2 ml of C1-C10 solution was dropped and spin coated at the number of revolutions shown in Table 4. This was kept at 285 ° C. for 1 hour for drying. Next, after cooling to room temperature, 2 ml of A1 liquid-A3 liquid was dripped as shown in Table 4, and it spin-coated at the rotation speed shown in Table 4. This was kept at 285 ° C. for 1 hour for drying. Baked at 630 ° C for 10 minutes,The glass plate which coat | covered the low reflection film on the surface of one side was obtained. Low reflection film for automobiles where the low reflection film is on the inside of the vehicle by using the glass plate with the low reflection film as the glass plate on the inside of the vehicle, and using the untreated vehicle outside glass plate and the intermediate film as the laminated glass in the lamination process. A glass article (untreated car outer glass plate-intermediate film-car inner glass plate-high refractive index film-low refractive index film) was obtained.
0038]
Table 4 ----------------------------------
                  High refractive index layer Low refractive index layer
        ----------------------------
            Coating solution rotation speed (Rotation / second) Coating solution Rotation speed (Rotation / second)
----------------------------------
Example
1 C1 liquid25.0(1500rpm) A1 liquid25.0(1500rpm)
2 C2 liquid25.0(1500rpm) A1 liquid25.0(1500rpm)
3 C3 liquid25.0(1500rpm) A1 liquid25.8(1550rpm)
4 C4 liquid25.0(1500rpm) A1 liquid25.8(1550rpm)
5 C5 liquid25.0(1500rpm) A1 liquid25.8(1550rpm)
6 C6 liquid25.0(1500rpm) A1 liquid25.8(1550rpm)
7 C1 liquid23.3(1400rpm) A1 liquid25.0(1500rpm)
8 C8 liquid25.0(1500rpm) A1 liquid26.7(1600rpm)
9 C9 liquid26.7(1600rpm) A1 liquid26.7(1600rpm)
10 C10 liquid28.3(1700rpm) A1 liquid26.7(1600rpm)
11 C1 liquid25.0(1500rpm) A2 liquid25.8(1550rpm)
12 C1 liquid25.0(1500rpm) A3 liquid25.8(1550rpm)
Comparative example
1 C4 liquid26.7(1600rpm) A1 liquid21.7(1300rpm)
---------------------------------
0039]
[Table 5]
==================================
                  High refractive index film Low refractive index film
          ------------ -------------
Number Refractive index n₁     Film thickness d₁         Refractive index n₂      Film thickness d₂
                          (Nm) (nm)
----------------------------------
Example 1 1.70 127 1.455 90
Example 2 1.72 127 1.455 90
Example 3 1.74 127 1.455 88
Example 4 1.76 127 1.455 86
Example 5 1.78 127 1.455 85
Example 6 1.80 126 1.455 84
Example 7 1.70 135 1.455 90
Example 8 1.86 123 1.455 83
Example 9 1.90 121 1.455 82
Example 10 1.95 118 1.455 83
Example 11 1.70 129 1.465 83
Example 12 1.70 129 1.470 83
Comparative Example 1 1.76 100 1.455 118
==================================
0040]
  As shown in Table 5, for Example 1, the layer of the first layer film of the vehicle interior glass plate with the low reflection film has a refractive index (n of 1.70).₁TiO with a film thickness of 127 nm₂・ SiO₂It was a thin film, and its composition was consistent with the liquid composition in Table 2. The layer of the second layer film is,Refractive index of 1.455 (n₂SiO having a film thickness of about 90 nm₂It was a thin film. The visible light transmittance and chromaticity of transmitted light (Lab color system) of this glass plate were as shown in Table 6. And an incident angle θ of about 12 degrees and about 60 degrees (From the vertical line of the glass plate surface and the film surface sideWith incident lightofWhen the light is incident from the film surface side at an angle formed, the reflectance of the reflected light, the chromaticity of the reflected light (Lab color system), and the stimulation purity of the reflected light are,It was as shown in Table 7. Also in Examples 2 to 12 and Comparative Example 1, the refractive index / film thickness / composition of each layer, the visible light transmittance / transmitted light chromaticity of the film-coated glass plate, the visible light reflectance of the film surface side incident, the reflected light Tables 5 to 7 show the chromaticity / stimulus purity. The composition of the second layer film of Example 11 is SiO 2₂ 90 mol%, B₂O_Three The composition of the second layer film of Example 12 is 10 mol%.₂ 90 mol%, Al₂O_Three It was 10 mol%. Tables 6 and 7 show the optical characteristics of the untreated glass plate as Comparative Example 2.
0041]
  From Table 7, the visible light reflectance of the film-coated glass plates of Examples 1 to 12 is 4.0~ 4.8%, untreated glass plate of Comparative Example 2 (7.20%)The difference subtracted fromAbout 2.4% or more, and at an incident angle of about 60 degrees, 10.0-10.6%, Comparative Example 2 (13.8%)The difference subtracted fromAbout 3.2% Or more reduction effect.
0042]
  On the other hand, in Comparative Example 1, the visible light reflectance at an incident angle of about 60 degrees showed the same degree of reflectance reduction effect as the embodiment, but the visible light reflectance reduction effect at an incident angle of 12 degrees ( About "visible light reflectance of untreated glass"-"visible light reflectance of glass with film") was about 1.2%, which was inferior to the example (about 2.4% or more).
0043]
  Further, the stimulation purity of the reflected light is about 31% in the comparative example 1 when the incident angle is 12 degrees, whereas it is 14.9 to 21.2% in the example, and the incident angle is 60 degrees. In this case, it is about 12% in the comparative example 1 and 1 to 5.5% in the example. The stimulation purity of the reflected light of the example at any incident angle is,Compared to Comparative Example 1,Excellent value with a small value.
0044]
  From the chromaticity of the reflected light (a²+ B²)^1/2When the incident angle is 12 degrees, the saturation of the reflected light is 10.6 in Comparative Example 1.ofAgainst,In the example, the saturation of the reflected light is 4.7 to 5.9, and the incident angle of 60 degrees is 6.6 in the comparative example 1.ofOn the other hand, it is 1.6-3.0 in an Example, and the reflected light color tone of this invention is compared with the comparative example 1.,It turns out that it is close to neutral gray.
0045]
[Table 6]
=============================
                                          Transmitted light chromaticity
            Visible light transmittance (%) ----------
Number a b
-----------------------------
Example 1 82.2-5.6 1.3
Example 2 82.3-5.5 1.3
Example 3 82.3-5.5 1.3
Example 4 82.4-5.5 1.3
Example 5 82.5-5.5 1.3
Example 6 82.5-5.5 1.3
Example 7 82.0-5.4 1.0
Example 8 82.6-5.5 1.3
Example 9 82.6-5.5 1.3
Example 10 82.6-5.5 1.3
Example 11 82.2-5.6 1.3
Example 12 82.2-5.5 1.3
Comparative Example 1 80.8-5.2 2.6
Comparative Example 2 80.0 -5.8 0.6
=============================
0046]
[Table 7]
==================================
           Visible light reflectance Reflected light chromaticity Reflected light
               (%) 12 degrees 60 degrees Irritation purity (%)
            ------ ------------- --------
Number 12 degrees 60 degrees a b a b 12 degrees 60 degrees
----------------------------------
Example 1 4.52 10.3 -2.8 -4.5 -0.2 -1.7 19.7 4.8
Example 2 4.47 10.2 -3.0 -4.7 0.0 -1.9 19.7 4.0
Example 3 4.40 10.1 -3.1 -4.6 0.2 -1.9 19.3 3.0
Example 4 4.33 10.1 -3.1 -4.6 0.4 -1.9 19.7 2.6
Example 5 4.28 10.1 -3.2 -4.6 0.6 -1.9 19.7 1.0
Example 6 4.23 10.1 -3.3 -4.6 0.8 -2.0 19.9 2.4
Example 7 4.8 10.3 -3.7 -2.9 -0.7 -2.4 15.4 4.3
Example 8 4.1 10.1 -3.3 -4.9 1.4 -2.0 20.9 4.4
Example 9 4.1 10.0 -3.6 -4.7 1.8 -2.1 21.2 3.5
Example 10 4.0 10.0 -3.2 -5.0 2.2 -2.1 19.7 5.5
Example 11 4.5 10.6 -2.4 -4.5 0.1 -2.7 16.7 2.4
Example 12 4.6 10.6 -2.4 -4.6 0.9 -1.3 14.9 2.4
Comparative Example 1 5.95 9.8 -3.8 -9.9 0.3 -6.6 31.4 11.7
Comparative Example 2 7.20 13.8 -1.2 -0.7 -1.7 -0.4 2.9 2.8
==================================
0047]
【The invention's effect】
  As described above, the low reflection glass for automobiles of the present invention.ArticleA thin film with a high refractive index from the glass surface sideLayer andNext, a thin film having a specific refractive index and a predetermined film thickness as a low refractive index thin filmLayer andIn combination with a simple two-layer thin film coating, it meets the requirement of visible light transmittance of 70% or more required for windshields, and reflects visible light to obliquely incident light from the film surface side at an incident angle of 12 degrees. Rate can be kept below 4.8%, and visible light reflectance for obliquely incident light with an incident angle of 60 degrees can be kept below 11%, for example,,It is possible to reduce the reflection on the driver's eyes with respect to obliquely incident light entering from a dashboard or the like.
0048]
  Also,Low reflection glass for automobile of the present inventionArticleIs the visible light reflectance when visible light is incident at an incident angle of 12 degrees and 60 degrees from the film surface side, respectively.TheVisible light reflectance at incidence angles of 12 and 60 degrees on a normal glass surface without a thin film coatingThe difference subtracted from, At least 2.4% eachthat's allAnd at least 3.2%ReducedIt has visible light reflectance.
0049]
  Moreover, the low reflection glass for automobiles of the present invention.ArticleAre reflected light of 22.0% or less when incident at the incident angles of 12 degrees and 60 degrees, respectively.10. Since it has a stimulus purity of 0% or less, it can suppress glare when viewed from the inside of the car, and the amount of reflection is suppressed.,For use in automobiles that improve transparency, prevent misperceptions and discomfort, and are highly durable and environmentally friendly for passengers and people such as drivers.Low reflection glass articleIt will be.

Claims (7)

A thin film layer having a refractive index (n ₁ ) of the first layer of 1.65 to 2.20 and a film thickness of 110 to 150 nm is coated on at least one surface of the transparent glass substrate from the glass surface side. And
Next, a refractive index (n ₂ ) of 1. is formed as a second layer on the first layer thin film. 40 to 1.4 7 a and the thickness is at a substantially coating stack a thin film layer composed only of SiO ₂ 81~100nm,
A low-reflection glass article for automobiles, in which reflected light when visible light is incident at an incident angle of 12 degrees and 60 degrees from the film surface side has an excitation purity of 22% or less and 10% or less, respectively. The refractive index of the first layer thin film layer (n ₁₎ is a low reflection glass article for automobiles according to claim 1, wherein Ru der 1.67 to 1.80. The refractive index (n of the first layer) counted from the glass surface side on at least one surface of the transparent glass substrate ₁ ) Is 1.65 to 2.20, and a thin film layer having a film thickness of 110 to 150 nm is coated,
Next, a refractive index (n ₂ ) Of 1.40 to 1.49 and a film thickness of 81 to 100 nm. ₂ As the main component and B ₂ O _Three And / or Al ₂ O _Three A thin film layer containing only a laminated coating,
A low-reflection glass article for automobiles, in which reflected light when visible light is incident at an incident angle of 12 degrees and 60 degrees from the film surface side has an excitation purity of 22% or less and 10% or less, respectively. The low reflective glass article for automobiles according to any one of claims 1 to 3, wherein the first thin film layer contains SiO ₂ and TiO ₂ . The first layer thin film layers molar ratio _{Ti O 2: Si O 2 =} 35: 65~60: Automotive low reflection glass according to any one of the thin film Der Ru請 Motomeko 1-4 40 Goods. Visible light reflectance is 4.8% or less and 11.0% or less when visible light is incident on the low-reflection glass article for automobiles at an incident angle of 12 degrees and 60 degrees from the film surface side , respectively. The low reflection glass article for automobiles according to any one of claims 1 to 5 , which has a light reflectance. The low reflection glass article for automobiles, 12 degrees and 60 degrees visible light reflectance, the glass surface without the usual film coating having entered each at an angle of incidence 12 ° and 60 ° visible light from the film surface side minus the visible light reflectance at an incident angle of, respectively, at least 2.4% or more and at least 3. The low reflection glass article for automobiles according to any one of claims 1 to 6 , which has a visible light reflectance reduced by 2 % or more .