WO2003062165A1 - Glass sheet with low reflection coating - Google Patents

Abstract

A glass sheet having a low reflection coating composed of two layers, characterized in that it exhibits a visible light transmissivity of 70 % or more and an insolation transmissivity of 55 % or less, the value obtained by deducing a visible light transmissivity of the glass sheet freed of the low reflection coating from the above visible light transmissivity is 2 % or more, and it contains iron oxides in an amount of 0.3 to 1 mass % in terms of Fe2O3. The glass sheet allows the increase in the absorption of insolation by that corresponding to the transmissivity increased due to the low reflection coating.

Description

 Description Glass plate with low reflection film

Technique field

 The present invention relates to a glass plate with a low reflection film, and more particularly to a glass plate with a low reflection film for automobiles, which is suitable for windshield laminated glass for automobiles. Background art

Glass sheets for automobiles are required to have the ability to shield infrared rays in order to reduce the cooling load. For example, combined in JP 2001- 1 51 539, a glass plate ing from the source one da-lime-silica glass containing from 0.3 to 1% total iron as calculated F e ₂ 0 _3, which were combined in the intermediate layer containing an infrared shielding fine particles Glass has been proposed.

 However, the ability to block infrared rays with iron oxide and fine particles is substantially limited by laws and regulations that require that the visible light transmittance of a given glass window of a vehicle exceed a specified value (70%, or 75% in some regions). Is restricted. In glass sheets for automobiles, iron is added only in a range that satisfies the visible light transmittance that complies with laws and regulations, or infrared shielding fine particles are added to the intermediate film to reduce the solar transmittance.

It has also been proposed to use a low-reflection film on the windshield glass of automobiles to prevent reflection of dashports. For example, the present applicant discloses in Japanese Patent Application Laid-Open No. 2000-256042 that at least one surface of a transparent glass substrate has a refractive index ( _{η ι} ) of 1.65 to 2 as a first layer counted from the glass surface side. In step 20, a thin film having a thickness of 110 to 150 nm is formed. Then, on this first layer, as a second layer, the refractive index (n ₂ ) is 1.37 to 1.49. A thin film layer composed mainly of silica with a film thickness of 81 to 100 nm is laminated, and visible light is incident from the film surface side at incident angles of 12 degrees and 60 degrees, respectively. We have proposed a low-reflection glass article for automobiles that has a stimulus purity of 22% or less and 10% or less, respectively, when reflected.

Disclosure of the invention

 Conventionally, a low-reflection film has been used to prevent glare on dashboards of automotive glass plates. However, in the present invention, by using a low-reflection film, it is possible to not only prevent glare but also prevent infrared rays from being reflected. And to maintain and improve visible light transmittance.

The present invention is a glass plate provided with a low-reflection film on which a low-reflection film composed of two layers is formed, having a visible light transmittance of 70% or more and a solar transmittance of 55% or less, the value obtained by subtracting the the visible light transmittance from the visible light transmittance in a state other than the low-reflection film is not less than 2%, the glass plate, 0 iron oxide F e ₂ 0 ₃ basis. 3 -1% by mass, preferably 0.5-1% by mass.

BRIEF DESCRIPTION OF THE FIGURES

 FIG. 1 is a sectional view showing an example of a glass plate provided with a low reflection film according to the present invention.

 FIG. 2 is a cross-sectional view showing another example of the glass plate with a low reflection film according to the present invention.

Embodiment of the Invention

The present invention utilizes the effect that the low reflection film provided on the transparent body suppresses the reflection of light, thereby increasing the amount of transmitted light of the transparent body. For example, using a glass plate having a visible light transmittance of at least 68%, while maintaining a visible light transmittance of at least 70%, the solar transmittance of a glass plate without a low reflection film is substantially reduced. maintain. In the present invention, for example, the value obtained by subtracting the solar transmittance of the glass plate provided with the low reflection film from the solar transmittance excluding the low reflection film can be set to 1% or less. In one embodiment of the present invention, the visible light transmittance of the glass plate provided with a low reflection film is 70% or more, and the visible light transmittance excluding the low reflection film is less than 70%. In another embodiment of the present invention, the visible light transmittance of the glass plate provided with a low reflection film is 75% or more, and the visible light transmittance excluding the low reflection film is less than 75%. In still another embodiment of the present invention, the solar radiation transmittance can be reduced to 50% or less, and further to 45% or less, while maintaining the visible light transmittance at 70% or more. The visible light transmittance of 75% or more corresponds to the legal regulations on glass windows for automobiles in Europe.

The low-reflection film, for example, has a refractive index (η ガ ラ ス .68 to 2.3 and a film thickness (dt) of 100 to 140 nm, counted from the glass side, The second layer is a two-layer film having a refractive index (n ₂ ) of 1.4 to 1.5 and a thickness (d ₂ ) of 80 to 110 nm. so the combination of n have d have n _2, d _2, effect on the optical properties vary considering this, 1 ^ = 1. 7 0~: . 1. 9 5, n 2 = 1. 4 0 ~ 1.47 is more preferred.

 As the glass plate, a single glass plate of a green, bronze, drip, UV cut bronze, or UV cut bronze system, preferably a daline or UV cut green glass can be used.

 The glass plate may be a laminated glass formed by bonding at least two single glass plates via a thermoplastic interlayer. It is preferable that the interlayer film of the laminated glass contains ITO fine particles having a particle diameter of 0.2 xm or less, for example, in a ratio of 0.01 to 0.8% by mass with respect to the interlayer film.

When a laminated glass is used, the same or different types of glass plates selected from the single glass plate and the clear glass plate exemplified above may be appropriately used in combination. However, the combination of clear glass plates should be excluded. If laminated glass, at least two single glass plates But both, F e ₂ 〇 ₃ iron oxide conversion from 0.3 to 1 wt%, preferably 0.5 to 1 wt%, preferably has a composition containing.

 The low-reflection film has a visible light reflectance of 4.8% or less and 11.0% or less when visible light is incident from the film surface side at incident angles of 12 degrees and 60 degrees, respectively. You may have.

 The low-reflection film has a visible light reflectance when visible light is incident from the film surface side at incident angles of 12 degrees and 60 degrees, respectively. It may have a visible light reflectance that is at least 2.4% and at least 3.5% smaller than the visible light reflectance at the plane of incidence at angles of 12 degrees and 60 degrees, respectively.

The low-reflection film has a stimulating purity of 22% or less and 10% or less, respectively, when visible light is incident from the film surface side at incident angles of 12 degrees and 60 degrees, respectively. Is also good. - The first layer of the low reflective film, containing S i 0 ₂ and T i 0 _2, or may be substantive to the thin film consisting of only T I_〇 _2.

The first layer has a molar ratio of Ti: Si = 35: 65-: L00: 0. The second layer may be composed mainly of S i 0 _2, but may also be a thin film made of substantially only S i 0 _2.

 (Low reflection film)

First, the low reflection film constituting the glass plate with a low reflection film according to the present invention will be described. The first layer (high-refractive-index film) of the two-layer type low-reflection film preferably has a refractive index ( _ηι ) = 1.68 to 2.3 and a film thickness (d ^ OOl AO nm).

The refractive index of the first layer (If 11 is less than 1.68, a sufficient effect of reducing the reflected light intensity with respect to incident light from a high incident angle to a low incident angle cannot be obtained. (If n is greater than 2.3, the reflectance at a specific wavelength Although it can be lowered, when viewed over the entire visible range, coloring and reflection become strong, the visible light transmittance becomes 70% or less, and the desired reflection reduction effect cannot be obtained. The preferred range of the refractive index (η,) of the first layer is from 1.70 to 1.95.

 When the thickness of the first layer film (d is smaller than 100 nm, the reflectivity at a high incident angle is large. On the other hand, when the thickness (d) of the first layer film is larger than 140 nm, the low incident angle is small. , The reflectance increases.

The first layer preferably contains Si ₂ and Ti 0 ₂ as main components or substantially only Ti 0 ₂ . By mixing various combinations of T i O ₂ with a relatively high refractive index (refractive index = about 2.3) and S i 0 ₂ with a relatively low refractive index (refractive index = about 1.45), The refractive index (η,) of the first layer can be freely controlled in the range of 1.7 to 2.3. In the case of refractive index = 2.3, the first layer becomes Rukoto consist substantially only T i 0 _2.

When the first layer is composed mainly of S i 0 ₂ and T i 0 ₂ , or substantially only T i 0 ₂ , a film having excellent durability can be obtained. As or other components were the refractive index (]! = 1.6 from 8 to 2.3 in range satisfying, Z R_〇 ₂ (refractive index = 1.9 approximately _{5), C e 0 2,} B i 2 0 ₃ and the like, may be added in an amount of 1 0% by mass or less in their total.

Further, the second layer (low-refractive-index film) of the low-reflection film has a refractive index (n ₂ ) of 1.4 to 1.5 and a thickness (d ₂ ) of 80 to: L 10 nm.

The smaller the refractive index (n ₂ ) of the second layer, the greater the reflection reducing effect. However, in the case of an optical thin film having a refractive index (n ₂ ) of 1.4 or less, the density of the film becomes smaller and the unevenness of the surface becomes larger. For this reason, the abrasion resistance, chemical resistance, antifouling property, weather resistance, etc. are deteriorated, and it is difficult to realize an optical thin film having both durability and durability. If the refractive index (n ₂ ) of the second layer exceeds 1.5, a desired reflection reduction effect cannot be obtained. The preferable refractive index (n ₂ ) of the second layer is from 1.40 to 1.47.

If the thickness (d ₂ ) of the second film is less than 80 nm, the intensity of the reflected light cannot be sufficiently reduced. When the thickness (d ₂ ) of the second film exceeds 100 nm, the reflectance at low incident angles increases.

The second layer preferably consists essentially S i 0 _2. A film whose second layer is substantially made of SiO ₂ is preferable because it has excellent chemical stability, thermal stability, and mechanical strength.

The refractive index of the SiO ₂ film is about 1.45, although it depends on the manufacturing method. If therefore lower refractive index of the film is required, or to form a minute irregular shape on the surface of the S io ₂ film, as S i 0 ₂ film inside the independent foam or through pores like porous, the apparent May be lowered. Further, inorganic fine particles having a low refractive index may be put in the film to lower the refractive index.

The second layer, S i 0 but is preferably ₂ film, to the extent that the refractive index of the second layer (n ₂₎ satisfies 1.5 or less, B ₂ 0 ₃ other than S I_〇 _2, an oxide such as a 1 ₂ 0 _3, no problem also contain 1 to 5 mol% or less in total. As a method for forming the first layer and the second layer of the low reflection film in the present invention, it is possible to form them by a sol-gel method, a sputtering method, or a CVD method. Of these, the sol-gel method is desirable from the viewpoint of cost.

 When the first layer and the second layer constituting the low reflection film of the present invention are formed by a sol-gel method, a uniform film can be easily obtained and high durability can be obtained in addition to good film forming properties. is there.

 (Sol-gel method)

The coating method of the coating solution by the sol-gel method includes spin coating, dip coating, meniscus coating, flow coating, Roll coating, gravure coating, flexographic printing, screen printing, and the like.

For example, if the first layer of the low reflection film of the present invention when forming the sol one gel method, i.e. for forming an optical thin film containing titanium oxide (T i 0 ₂₎ and silicon oxide (S I_〇 _2), The coating liquid composition comprises a titanium compound, a silicon compound and a solvent, and can be obtained by mixing the titanium compound and the silicon compound in an organic solvent.

 Further, for example, when the second layer of the low reflection film in the present invention is formed by a sol-gel method, that is, when it is formed as an optical thin film containing silicon oxide, the coating liquid composition contains a silicon compound and a solvent. And can be obtained by mixing a silicon compound with an organic solvent.

The first layer is formed by sol-gel method, T i 0 ₂ molar ratio: S I_〇 _{2 = 3 5: 6 5~:} L 0 0: 0 and then, the same second layer, only S i 0 ₂ Preferably.

But Among combinations of the components described above, Ding 1_Rei ₂ Oyobi 3 1 0 _2, since their alkoxides is stable, which is preferable.

 As a titanium compound which is a starting material of titanium oxide contained in the first layer, titanium alkoxide, titanium alkoxide chloride, titanium chelate and the like are used. Examples of the titanium alkoxide include titanium methoxide, titanium ethoxide, titanium n-propoxide, titanium isopropoxide, titanium n-butoxide, titanium isobutoxide, titanium methoxypropoxide, titanium stearyl oxide, titanium 2-ethylhexoxide, and the like. Can be exemplified.

Examples of the titanium alkoxide chloride include titanium chloride triisopropoxide, titanium dichloride diethoxide and the like. Titanium chelate is titanium triisopropoxaside (2,4-pentanedio) Net), titanium diisopropoxide (bis-2,4-pentanedionate), titanium aryl acetate triisopropoxide, titanium bis (triethanolamine) diisopropoxide, titanium di-n- Butoxide (bis-2,4-pentanedione) is used.

 The silicon compound, which is the starting material of silicon oxide contained in the first and second layers, is obtained by mixing silicon alkoxide with a solvent such as alcohol and promoting hydrolysis and polymerization with an acidic or basic catalyst. Is used. As the silicon alkoxide, silicon methoxide, silicon ethoxide, or an oligomer thereof is used.

 As the coating liquid composition for forming the second layer, in addition to the silicon compound, the boron compound to be contained is, for example, polon methoxide, polonethoxide, polon n-propoxide, boron i-propoxide, boron n-butoxide, or polone. S-butoxide, boron t-butoxide and chelating compounds thereof are used.

 Aluminum compounds added as a coating liquid composition for forming the second layer include aluminum methoxide, aluminum ethoxide, aluminum n-propoxide, aluminum i-propoxide, aluminum n-butoxide, and aluminum. s-butoxide, aluminum t-butoxide and their chelating compounds are used.

 As the chelate compound, aluminum (di-s-butoxide) ethyl acetate, aluminum (S-butoxide) bisethyl acetate, aluminum (di-propoxide) ethyl acetate, and the like are conveniently used.

The acid catalyst contained in the coating liquid composition for forming the first and second layers includes hydrochloric acid, sulfuric acid, nitric acid, hydrochloric acid, acetic acid, oxalic acid, trichloroacetic acid, trifluoroacetic acid, phosphoric acid, and hydrofluoric acid , Formic acid and the like are used. salt Ammonia and amines are used as the basic catalyst.

 Further, the organic solvent used in the coating liquid composition for forming the first layer and the second layer depends on the coating method. However, methanol, ethanol, isopropanol, butanol, hexanol, octanol, 2 -Methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, cellosolve acetate, diethylene glycol monoethyl ether, hexylene glycol, diethylene glycol, tripropylene glycol, diacetone alcohol and the like.

 As the coating liquid composition, the above-mentioned solvents may be used alone or in combination of a plurality of solvents in order to adjust the viscosity and surface tension of the coating liquid. Small amounts of stabilizers, leveling agents, thickeners, etc. may be added as necessary. The amount of the solvent used also depends on the thickness of the Δ-refractive index film and low-refractive index film finally obtained and the coating method to be employed. In general, the solvent should be used so that the total solids is in the range of 1 to 20%.

 After applying the above coating liquid composition by the above-mentioned coating method, drying or heating and baking at a temperature of 250 ° C. or more and repeating the step of applying the next coating liquid, a low reflection film is provided. A glass plate can be obtained.

 The low-reflection film thus obtained has excellent properties such as transparency, environmental resistance, and scratch resistance. In addition, with such a configuration, even if the layers are stacked, it is possible to suppress film peeling and generation of cracks in the process of densification of the first layer and the second layer. It is considered that this film peeling and cracks occur due to the difference in thermal shrinkage.

Instead of the above-described manufacturing method using drying and baking by heating at 250 ° C. or more, a light irradiation method described below can be used. That is, after coating the coating liquid composition by the coating method, This is a method of repeating the coat drying step, in which a step of irradiating the coating film with an electromagnetic wave having a shorter wavelength than that of the coating film is performed, followed by a step of coating the next coating liquid.

 Examples of electromagnetic waves having a wavelength shorter than that of visible light include τ-rays, X-rays, and ultraviolet rays. However, ultraviolet irradiation is preferable from the viewpoint of practicality of the apparatus in consideration of irradiation of a substrate having a large area. Excimer lamps, low-pressure mercury lamps, high-pressure mercury lamps, metal halide lamps, etc. are used as ultraviolet light sources.

Using a high-pressure mercury lamp that efficiently emits light at wavelengths of 254 nm and 303 nm with a main wavelength of 365 nm, 1 O mW / cm ² or more, preferably 50 mW / cm ² It is desirable to irradiate the coating film with an irradiation intensity of 100 mWZ cm ² or more, more preferably. - using such ultraviolet light source, 1 0 O m J / cm 2 or more, preferably 5 0 0 m JZ cm ² or more, more preferably 1 0 0 O m J / cm 2 or more radiation energy, above It is good to irradiate the surface coated with the above coating liquid composition. This makes it possible to obtain a low-reflection film having a laminated structure that is excellent in properties such as transparency, environmental resistance, and scratch resistance at low temperatures and is less likely to crack.

 Drying and / or baking by heat may be performed simultaneously while irradiating ultraviolet rays. A drying method by ultraviolet irradiation and a drying step by thermal drying, preferably at a temperature of 250 ° C. or lower, may be used simultaneously. By using the ultraviolet irradiation in this way, the drying process can be sped up and productivity can be dramatically improved.

 (Composition of glass plate)

Further, in the present invention, the visible light transmittance of the glass plate alone is, for example, a glass plate having a value less than the minimum value (70%, or 75% in some regions) according to laws and regulations for glass plates for automobiles. Less than the above minimum value and 6 Use a glass plate that is at least 8%. That is, for example, as a colored glass plate, a green, bronze, gray, high performance UV cut green glass, high performance UV cut bronze glass, or the like is preferable. In particular, it is more preferable that the window material for automobiles be of a green color, especially if it is easy to obtain heat ray / ultraviolet ray absorption performance.

 Examples of coloring components used in such a colored glass plate include iron, cobalt, nickel, and the like.

Of these, the soda lime silica glass containing iron as a coloring component, as represented by mass percentage to the mother glass soda lime silica, total iron from 0.3 to 1% in terms F e ₂ O _s, preferably 0. It is preferably soda lime silica glass containing 5-1%.

In addition, the absorption of light in the near-infrared region is dominated by divalent iron among the total iron. Thus, 6 and ₂ 0 _3-converted 60 (divalent iron), it is more preferred ratio of total iron as calculated F e ₂ 0 ₃ is 0.2 0 to 0.40.

 As the glass plate having the above characteristics, it is preferable to use soda lime silica glass substantially expressed by mass percentage and having the following composition. Expressed in mass%,

S i 0 ₂ : 65 to 80%,

_{A 1 2 0 3: 0~ 5} %,

MgO: 0 to 10%,

C a O: 5 to: 15%,

MgO + CaO: 5 to 15%,

_{N a 2 0: 1 0~ 1} 8%,

K ₂ 0: 0~ 5%,

N a ₂ 〇 + K ₂₀ : 10 to 20%, B ₂ 〇 ₃ : 0-5%,

A mother glass composition consisting of

As a coloring component,

Total iron oxide converted to Fe ₂ 〇 ₃ (T—Fe ₂ 0 ₃ ): 0.3 to 1.0%, CeO ₂ : 0 to 2.0%,

T i 〇 ₂ : 0 to 1.0%,

UV and infrared absorbing glass.

Further, the mother glass composition in the ultraviolet and infrared absorbing glass includes so ₃ :

Preferably, it contains 0.07 to 0.30%.

In the ultraviolet and infrared radiation absorbing glass, iron oxide, present in glass in the form of F e ₂ 0 ₃ and F e 0. F e ₂ 0 _3, together with the C E_〇 _2, T i 0 _2, a component for improving the ultraviolet absorptivity, F e O is a component for increasing the heat ray absorptivity.

In this case, the amount of total iron oxide (T-F e ₂ 〇 _3), when in the range of from 0.3 to 1.0%, in order to obtain a desired total solar energy absorption, F e OZT- F e ₂ 0 ₃ ratio, as the amount of F E_〇 of from 0.20 to 0.40 range is it is preferably Re of ^ this case, numerical values in terms of normal F e ₂ 0 ₃ Used.

Further, the glass of the above composition range, C O_〇, N _{I_〇, M nO, V 2 0 5} , Mo 0 3 , etc., also the S N_〇 ₂ as a reducing agent, one or more kinds as colorants May be added in an amount of 0 to 1% in a range that does not impair the greenish color tone intended by the present invention. In particular, since C O_〇 may grant a blue hue, is effective in the color tone of the glass can be inhibited from yellowing by F e ₂ 0 _3, C E_〇 _2, T i 0 ₂ quantity increase, The preferred range is from 3 to 20 ppm.

so ₃ contains iodine such as borate nitrate (sodium sulfate) added to the raw materials The yeo components in the raw materials remained in the glass as oxides. In this ultraviolet and infrared radiation absorbing glass, the amount of S_〇 ₃ plays a very important role.

This ultraviolet infrared錄absorbing glass, while containing _{F e 2 0 3, C e} 0 2 as an oxidizing agent relatively large amounts, it is necessary to set the degree of reduction higher than normal. As described above, lump undissolved in the sand (so-called scum) and a ream with a large amount of silica (so-called silica-rich ream) are likely to occur. To prevent this phenomenon, reduce the so ₃ content of the glass to 0 to promote the dissolution of gay sand.

It must be greater than 0 7%. This can be achieved by increasing the amount of PON added to the batch beyond the usual amount, for example by increasing the amount per 100 kg (1 tonne) of sand to about 20 kg or more. It is possible by adding another sulfate such as iron sulfate or the like as a raw material.

However, such an increase in the so ₃ content in the glass, on the other hand, causes another problem of foam formation by reboil, especially reboil by stirring. Such reboiling phenomenon is likely to occur as the S 0 ₃ content is high. The reboil To prevent reduction in the yield due to a phenomenon, S 0 ₃ content in the glass 0. 3 based to reduce desirably 0%. Further, while achieving the reduction of the desired glass, scum, while preventing the generation of silica-rich stream, to prevent foam generation by reboiling, adjusted S_〇 ₃ containing in glass in the desired range as above In order to do so, it is desirable to use sulfide ion-containing materials (for example, sulfides such as iron sulfide, blast furnace slag, for example, calmite manufactured by Calmite, and rivermite manufactured by Kawatetsu Mining) as raw materials.

The upper limit of the visible light transmittance of only the glass plate is not particularly limited in the present invention. However, a glass plate having a visible light transmittance of less than 75% is preferable because the increase in the visible light transmittance by the low reflection film is effective. Further, the glass plate is not limited to a colored glass plate, and may be, for example, a glass plate with a heat ray reflective film.

 Further, it may be a tempered glass plate or an untempered glass plate. In terms of shape, it may be a flat plate or a bent glass.

 Further, not only a single glass plate but also a laminated glass plate or a multi-layer glass plate may be used.

 Note that the above description of the colored glass plate is for a case where the glass plate is a single plate. For example, when composed of laminated glass, at least one single glass plate may be the transparent and colored glass plate described above, and the other single glass plate may be a clear plate.

 The glass plate in the present invention preferably has a thickness of 1.5 to 6.5 m (in the case of laminated glass or double-glazed glass, the thickness is defined as the distance between the outer surfaces of each glass plate).

Example

 The glass plate with a low reflection film according to the present invention will be described in detail using examples.

 (Examples 1 and 2)

 The glass plate with a low reflection film according to the first embodiment has the following configuration. · Composition: UVG 2.1 mmZ interlayer / UVG 2.1 mmZ low-reflection film UVG 2.1 mm is a UV cut green glass plate with a thickness of 2.1 mm.

FIG. 1 schematically shows a cross-sectional structure of the glass plate with a low-reflection film for an automobile of Example 1. The glass sheet 1 with a low-reflection film for automobiles connects the outside single glass sheet 1 1 and the inside single glass sheet 1 2 via the interlayer 13 (PVB film). The low-reflection film 2 (21, 22) is formed on the interior surface of the laminated glass.

A low-reflection film was formed on the surface of the glass plate 12 on the inside of the vehicle as follows. High refractive index film which is the first layer consists of T I_〇 ₂ and S I_〇 _2. It was formed by a sol-gel method. The film thickness was 130 nm, and the refractive index was 1.75.

The low refractive index film as the second layer was composed of Si ₂ and was formed by a sol-gel method. The film thickness was 90 nm, and the refractive index was 1.45.

 A laminated glass was produced using the above-mentioned glass substrates 11 and 12 using a normal intermediate film (PVB film) 13 through a known laminating process.

 Table 1 shows the optical characteristics of the glass samples in Examples 1 and the following Examples. Example 1 is an example in which a low reflection film was formed on the glass substrate of Sample 6.

Further, as Example 2, a glass plate with a low reflection film was produced in the same manner as in Example 1, except that the thickness of one UVG glass plate was changed to 1.8 mm. Example 2 corresponds to an example in which a low reflection film was formed on the glass substrate of Sample 11. In Example 2, the visible light transmittance was improved from 74% to 76% by forming the low reflection film.

(Table 1) Substrate 1 / Interlayer / Substrate 2 Visible light Visible light Solar irradiance Hay rate Transmittance («Reflectivity (%) Transmittance ((%)

12 degrees / 60 degrees 卄^Ίノ, "ノ 7 ° ル 11/1 1 丄 1

 S V (m is \ on 0 1/1 ς A

 0 0. Q 07 (. Λ

Sanfu. 2 Clear 2.1 / Normal / Clear 2.1 88, .8 7. .9 / 15. 76, .7 0., 1 Sanfu. 3 GRN2.1 (single board) 85. .0 7. .7 / 14.7 71. .0

Sanfu. Le 4 GRN2.1 / Nomal / GRN2.1 79. .0 7. .3 / 13.8 52. .1 0., 1 sanf. 5 UVG2.1 (single board) 81. .0 7.5 .14.2 62, .3

Sanfu. 6 6 UVG2.1 / Normal / UVG2.1 72.0.6.8/13.0 41,0.00,1 7 UVG2.3 (single board) 79..8 7.4 / 14.0 60..8

Sanfu. 8 UVG2.3 //-UVG2.3 69. .0 6.5 .5 / 12.8 38, .8 0. 9 UVG 6.0 (single board) 69, .5 6. .6 / 13.2 39, .1 0. • 1 sunf. 10 UVG2 • 1 / IT0 / UVG2.1 69. 0 6. 1 / 12.4 35. 5 0.2 Samp. 11 UVG2 • 1 / Normal / UVG1.8 74. 06.8 / 13.0 43.0 0.1 Clear: Uncolored glass plate (total iron oxide less than 0.3 wt.), GRN: Green glass plate, UVG : UV cut green glass plate, Normal: Normal PVB film, and specific compositions of the above-mentioned green glass plate and UV cut green glass are shown in Table 2 by mass%. (Table 2) Ingredients Leaning power, Lath (GRN) UV cut gelling power "Lath (UVG)

 () (%)

S io ₂ 7 1 0 7 0.1

A 1 ₂ 0 ₃ 5 5 1.57

 Mg O 4 1 2 3. 1 8

 C a〇 8 6 6 8.27

N a ₂ 0 3.3 14.6

κ ₂ ο 0.7 3 0.58

TF e ₂ 0 ₃ 0. 5 3 0. 7 3

T io ₂ 0. 0 3 0. 04

C e 0 ₂ 0.90

F e O / TF e ₂ 0 ₃ 0.24 0.245

Table 3 shows the optical characteristics of the glass plate with a low-reflection film for automobiles obtained in Example 1. In addition, the optical characteristics of other examples are also shown.

(Table 3) Substrate 1 / Interlayer / Substrate 2 Visible light Visible light Solar irradiance Hay rate Transmittance (%) Reflectance (%) Transmittance («(%)

 12 degrees / 60 degrees Example 1 UVG2.1 / Normal / UVG2.1 74.0 3.8 / 9.1 1.7 0.1 Example 2 UVG2.1 / Normal / UVG1.8 76.0 3.9 / 9.2 44.0 0.1 Example 3 UVG2. 1 / IT0 / UVG2.1 71.2 3.6 / 8.8 36.2 0.2 Example 4 UVG2.3 / Normal / UVG2.3 71.2 3.5 / 8.7 39.5 0.1 Example 5 GRN2.1 //-7J1 / GRN2.1 81.3 4.2 / 10.1 52.7 0.1 Example 6 UVG6.0 veneer) 71.5 3.6 / 8.8 39.8 0.1

According to Example 1, the visible light transmittance was 74%, indicating an increase in visible light transmittance of about 2% as compared with Sample 6 due to the low reflection film. The visible light reflectance showed a reduction effect of 3% at 12 degrees and about 4% at 60 degrees. In addition, the solar transmittance was reduced by about 35% compared to the laminated glass of the uncolored glass plate of Reference Example 1. From this, it was found that Example 1 had both excellent low reflection performance and excellent solar shading performance. (Example 3)

 The glass plate with a low reflection film for an automobile according to the third embodiment has the following configuration.

• Composition: UVG 2. mmZ ITO dispersion interlayer ZUVG 2.1 mmZ low reflection film In Example 3, the ITO fine particles were dispersed in the interlayer at a ratio of 0.1% by mass. First, ITO fine particles with a particle size of 0.2 m or less are dispersed in a plasticizer (3GH, manufactured by Sekisui Chemical Co., Ltd.) so that the solid content is about 10%. The liquid was prepared. To 100 parts of polyvinyl butyral (PVB) resin, 1 part of the above dispersion and 39 parts of plasticizer (3GH) (all parts by mass) were added to form an intermediate film.

 A laminated glass was produced in the same process as in Example 1, except that an intermediate film in which ITO fine particles were dispersed was used instead of the ordinary intermediate film. Table 3 shows the optical characteristics.

 According to Example 3, the visible light transmittance is 71.2%, which satisfies the automotive glass standard of 70% or more. Further, the solar radiation transmittance was further reduced by about 5% as compared with Example 1. From this, it was found that Example 3 has both excellent low reflection performance and solar shading performance.

 (Example 4)

 The glass plate with a low-reflection film for a vehicle according to the fourth embodiment has the following configuration.

• Composition: UVG 2.3mm / intermediate film ZUVG 2.3mmZ low-reflection film Example 4 is the same as Example 1, except that the thickness of the glass substrate is different. It is a glass plate with a low reflection film. Table 3 shows the optical characteristics. Example 4 is an example in which a low-reflection film was formed on the glass substrate of Sample 8.

According to Example 4, the visible light transmittance of the basic sample 8 was 69%, whereas the visible light transmittance was increased by forming the low-reflection film. It came to satisfy the glass standard. In addition, the visible light reflectance and the solar radiation transmittance were further reduced as compared with Example 1. From this, it was found that Example 4 had both excellent low reflection performance and solar shading performance.

 (Example 5)

 The glass plate with a low-reflection film for a vehicle according to the fifth embodiment has the following configuration.

• Configuration: GRN 2.1 mm / intermediate film ZGRN 2.1 mmZ low-reflection film In the fifth embodiment, the type of glass substrate is different from that of the first embodiment. Otherwise, a laminated glass was produced in the same configuration and in the same steps as in Example 1. Table 3 shows the optical characteristics. Example 5 is an example in which a low reflection film was formed on the glass substrate of Sample 4. According to Example 5, the visible light reflectance and the solar radiation transmittance were reduced as compared with Reference Example 1. Although Example 5 was inferior to Examples 1 to 3, it was found that both excellent low reflection performance and solar shading performance were compatible.

 (Example 6)

 The glass plate with a low reflection film for a vehicle according to the sixth embodiment has the following configuration.

• Configuration: UVG 6.0 (single plate) Z low-reflection film The cross-sectional structure of the glass plate with a low-reflection film for automobiles of Example 6 is schematically shown in FIG. The glass plate 1 with a low-reflection film for automobiles is obtained by forming a low-reflection film 2 (2 1, 22) on the inside surface of a single glass plate 10.

In Example 6, a single UV-cut green glass plate (6 mm thick, This is an example in which a low reflection film applied to the present invention is formed on the sample 9). According to Example 6, similar to Example 4, the visible light transmittance of the basic sample 9 was 69.5%, whereas the visible light transmittance was 69.5% due to the effect of forming the low reflection film. Increased to 71.5%. In addition, the visible light reflectance and solar radiation transmittance were also reduced, indicating that both low reflection performance and solar shading performance were achieved.

 As described above in detail, in the glass plate with a reflective film according to the present invention, a low reflective film is applied to a glass plate that absorbs in the visible light region. For this reason, excellent low reflection performance and high visible light transmittance can both be achieved. Furthermore, when the glass sheet constituting the glass sheet with a low reflection film according to the present invention is a heat ray absorbing glass, both low reflection performance and solar shading performance can be achieved.

 Further, in the glass plate with a low reflection film according to the present invention, since the low reflection film is formed on the surface, reflection loss on the surface of the glass plate can be suppressed. As a result, the transmittance as a glass plate can be improved, so that the ability of the glass substrate to absorb solar radiation can be further increased.

 Specifically, even if the glass plate has a visible light transmittance of less than 70% or less than 75%, according to the present invention, the visible light transmittance is 70% or more and 75% or more, respectively. As a glass sheet for automobiles. As a result, better solar shading can be obtained.

 Furthermore, even in the case of using an interlayer in which ITO fine particles effective as a heat ray absorber are dispersed, the transmittance as a glass plate can be improved, as described above, so that a high absorption glass plate is used. can do. As a result, excellent solar shading performance can be obtained even when the amount of dispersion of expensive ITO fine particles is small. This greatly contributes to cost reduction.

Claims

The scope of the claims 1. A glass plate provided with a low-reflection film on which a low-reflection film composed of two layers is formed, wherein the visible light transmittance is 70% or more, the solar radiation transmittance is 55% or less, and the visible light transmittance is the value obtained by subtracting the visible light transparently rate in a state excluding the low-reflection film is at least 2%, the glass plate is 0.1 3 containing 1 wt% of iron oxide of F e ₂ 〇 ₃ Convert A glass plate with a low-reflection film, characterized by having the following composition. 2. The glass plate with a low reflection film according to claim 1,  A glass plate with a low reflection film, wherein a value obtained by subtracting the solar light transmittance in a state excluding the low reflection film from the solar light transmittance is 1% or less. 3. The glass plate with a low reflection film according to claim 1,  A glass plate with a low-reflection film having a visible light transmittance of less than 70% without the low-reflection film. 4. The glass plate with a reflective film according to claim 1,  A glass plate provided with a low-reflection film, wherein the visible light transmittance is 75% or more, and the visible light transmittance excluding the low-reflection film is less than 75%. 5. The glass plate with a low reflection film according to claim 1, The low-reflection film, counted from the glass plate side, has a first layer having a refractive index of 1.68 to 2.3 and a film thickness of 100 nm to 140 nm, and a second layer having a refractive index of 1. 4-1.5, 80 nm-thickness: A glass plate with a low-reflection film with a thickness of 10 nm. 6. The glass plate with a low reflection film according to claim 1, wherein the glass plate is a laminated glass obtained by bonding at least two single glass plates via a thermoplastic intermediate film, Wherein the at least two single glass plates are both, F e ₂ 0 ₃ low reflection film-coated glass plate having a 0. 3 composition containing 1 wt% of acid iron conversion. 7. The glass plate with a low reflection film according to claim 6, Wherein the at least two single glass plates are both, F e ₂ 0 ₃ low reflection film-coated glass plate having a 0. 5 composition containing 1 wt% of acid iron conversion. 8. The glass plate with a low reflection film according to claim 1,  The glass plate is a laminated glass in which at least two single glass plates are bonded via a thermoplastic interlayer,  The glass with a low reflection film, wherein the thermoplastic intermediate film contains infrared shielding fine particles having a particle size of 0.2 m or less in a ratio of 0.01 to 0.8% by mass based on the thermoplastic intermediate film. Board.