JPH07330380A - Ultraviolet ray shielding glass - Google Patents

Abstract

PURPOSE:To produce an ultraviolet ray shielding glass excellent in chemical and physical durabilities, ultraviolet ray absorbing performances and transparency. CONSTITUTION:This ultraviolet ray shielding glass is obtained by forming an ultraviolet ray absorbing film such as zinc oxide on a glass substrate and covering the surface thereof with an outer layer film of oxides comprising two components of silicon (Si) and cerium (Ce). When the outer layer film is formed by coating a mixed silicone-cerium mixed coating liquid, the solid ratio (molar ratio) SiO2:CeO2=(x):(y) of the SiO2 to CeO2 is preferably within the range of 1.0-4.0 and the solid ratio (y) of CeO2 is especially preferably within the range of 1.0<=(y)<=3.0 by considering the ultraviolet ray shielding performances and color tone. The film thickness of the outer layer film is pref >=0.1mum and especially preferably >=0.2mum in order to impart ultraviolet ray shielding properties.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of ultraviolet blocking glass having an ultraviolet absorbing film provided on a glass substrate.

[0001]

2. Description of the Related Art Conventionally, as a means for providing an ultraviolet absorbing film on a transparent glass substrate, a method of forming a substance having an ultraviolet absorbing ability by a vacuum film forming method such as sputtering, or an ultraviolet absorbing agent for an organic or inorganic binder. It is known to dissolve or disperse and apply it on the glass surface.

[0002]

[Problems to be Solved by the Invention]
In a vacuum film forming method such as sputtering in which a substance having an ultraviolet absorbing ability is formed on a glass substrate, the cost performance of the apparatus is relatively high and the operation is complicated because a vacuum system is required. Further, as a means for selectively reducing only the transmittance of ultraviolet rays without reducing the transmittance of visible rays, a multilayer film interference method of alternately laminating films having different refractive indexes is used. It takes time, and the cost is high due to the multiple layers.

Further, in a method of coating an ultraviolet absorber with an organic or inorganic binder on a substrate, conventionally, a benzophenone-based or benzotriazole-based organic material or titanium oxide, zinc oxide, or oxide is used as the ultraviolet absorber. Inorganic oxides such as cerium are known. However, organic UV absorbers deteriorate due to heat, and
There are problems such as deterioration and discoloration due to ultraviolet rays.

On the other hand, inorganic oxides such as titanium oxide, zinc oxide, and cerium oxide have no absorption in the visible light region, but have an absorption in the ultraviolet region, and are therefore useful as ultraviolet cut glass. In particular, zinc oxide has high ultraviolet absorption performance,
It is expected to be used in a wide range of fields. However, when zinc oxide is used as an ultraviolet absorber, there is a problem in that it has poor chemical durability and is difficult to use in a monolayer film.

To solve this problem, Japanese Patent Laid-Open No. 4-182327
In the publication, SiO ₂ , ZrO ₂ —B ₂ O ₃ , and SiO ₂ — are used as an overcoat film of an ultraviolet absorbing film containing ZnO.
Providing a metal oxide such as ZrO ₂ has been proposed, but the outer layer coating provides an effect as a protective layer,
The film itself did not have an ultraviolet absorbing property.

[0006]

SUMMARY OF THE INVENTION The present invention is intended to improve the durability of a zinc oxide film, which has a poor chemical durability, which the prior art has, and uses silicon (Si) and cerium as outer layers. By using an oxide composed of two components (Ce), an ultraviolet absorbing glass having high durability is provided. Further, by using an oxide of cerium which is an ultraviolet absorber as a component of the outer layer coating, the ultraviolet absorption performance is further enhanced.

The zinc oxide film, which is an ultraviolet absorbing film, can be manufactured by a physical film forming method such as a vacuum vapor deposition method, a sputtering method, an ion plating method, or a CVD (chemical vapor deposition method). From the viewpoint of increasing the film thickness and increasing the film thickness, a method of applying a coating liquid containing zinc oxide onto a substrate is simple and effective.

In the method of applying a coating solution containing zinc oxide onto a substrate, as a material of zinc oxide, nitric acid, an inorganic salt such as hydrochloric acid, a compound having a chelate ligand such as acetylacetone, Zn (OR ₁ ) ( An alkoxy compound represented by R ₁ : alkyl group) can be used. Alternatively, commercially available zinc oxide fine particles may be dispersed in an organic solvent for use.

As the coating method, there are a flow coating method, a spraying method, a dipping method, a roll coating method, a spin coating method, a screen printing method and the like, and any of these methods can be applied. The film is provided on at least one side of the glass substrate, and may be provided on both sides as necessary. The thickness of the ultraviolet shielding film is preferably 0.5 μm or more in order to have a large ultraviolet shielding effect.

Regarding the binary oxides of silicon and cerium for the outer layer coating, a multi-source simultaneous vacuum deposition method, a physical method of forming a film by a sputtering method using a silicon-cerium composite as a target, or a silicon-cerium composite. A CVD (Chemical Vapor Deposition) method of reacting an object with a gas on a substrate is conceivable, but a method of preparing a silicon-cerium mixed coating solution and applying it on the substrate is simple. As a coating method, there are a flow coating method, a spraying method, a dipping method, a roll coating method, a spin coating method, a screen printing method and the like, and any of these methods can be applied. Further, the film is provided on at least one side of the glass substrate, and may be provided on both sides in some cases.

The silicon-cerium mixed coating liquid has a solid content ratio (mol ratio) of SiO ₂ and CeO _2.
2 : CeO ₂ = x: y is preferably in the range of 1.0 to 4.0, but considering the ultraviolet shielding performance and the color tone, the range of 1.0 ≦ y ≦ 3.0 in terms of the solid content ratio of CeO ₂ is. Especially desirable.

When 0 ≦ y <1.0, the CeO ₂ content is small, and the effect of shielding the added ultraviolet light becomes small.
On the other hand, if 3.0 <y, the refractive index of the film will be high and the color tone will not be neutral. The film thickness of the outer layer coating is preferably 0.1 μm or more, and particularly preferably 0.2 μm or more in order to impart the ultraviolet shielding property.

As the raw material of SiO ₂ which is the outer layer coating,
Examples thereof include alkoxy compounds represented by Si (OR ₁ ) (R ₁ : alkyl group) represented by tetraethoxysilane, silica sol, and the like.

When forming a film of an alkoxy compound, a solvent, water and a catalyst are mixed in advance with alkoxysilanes such as tetraethoxysilane to promote hydrolysis and polycondensation. Alcohols such as ethanol and isopropanol are added as solvents, acidic substances such as hydrochloric acid, nitric acid and acetic acid, and alkaline substances such as ammonium hydroxide are added to the catalyst. For hydrolysis and polycondensation, the reaction is accelerated by stirring at 50 ° C. to 80 ° C. in warm water for 10 hours or more. When the hydrolysis time is not longer than 10 hours, the liquid agglomerates when the CeO ₂ sol is added.

Further, as a raw material of CeO ₂ , inorganic salts such as cerium chloride and cerium nitrate, compounds having a chelate ligand such as acetylacetone, and cerium (IV) isopropoxide (Ce (O-iC ₃ H ₇ )). Examples thereof include alkoxy compounds represented by ₄ ), ceria sol, and the like.

The coated film was kept at room temperature for several minutes, then 70-2.
A transparent ultraviolet absorbing film is produced by drying at 00 ° C. for 30 minutes and baking at 500 to 600 ° C. for 5 to 60 minutes. However, when applying the outer layer coating after applying the ultraviolet shielding film,
The ultraviolet shielding film may be provided with the outer layer coating only in the drying step, and of course, the outer layer coating may be provided after firing. However, the outer layer coating is poor in durability only by drying, and the firing step is always performed.

[0017]

The UV blocking glass according to the present invention exhibits excellent chemical and physical durability by providing a two-component oxide of silica and cerium in the outer layer coating, and is an ultraviolet absorber as the outer layer coating. Since it has cerium oxide, it can enhance the ultraviolet absorbing performance in addition to the ultraviolet shielding film. Further, since it has transparency to visible light, it can be used in various fields such as window glass for vehicles such as automobiles and glass for houses.

[0018]

EXAMPLES The present invention will be specifically described below with reference to examples of the present invention, but the present invention is not limited to the examples.

Example 1 Tetraethoxysilane 100
Parts by weight, 200 parts by weight of isopropyl alcohol, 0.1
25 parts by weight of N hydrochloric acid was mixed and stirred in warm water at 50 ° C. for 10 hours. 5 parts by weight of zinc oxide fine particles (manufactured by Sakai Chemical Industry Co., Ltd.) were added to 100 parts by weight of the SiO ₂ hydrolyzed solution thus prepared and mixed, and uniformly dispersed in a ball mill for 50 hours to prepare a coating solution. This is designated as solution A.

100 parts by weight of tetraethoxysilane, 220 parts by weight of ethanol, 35 parts by weight of water and 3 parts by weight of acetic acid were mixed and stirred in warm water at 50 ° C. for 14 hours. Thus to SiO ₂ hydrolyzed solution 100 parts by weight of the adjusted water dispersion CeO ₂ colloidal sol (Taki Chemical Co., Ltd. trade name U-15 CeO ₂ 15%) 300 parts by weight of (SiO _2:
CeO ₂ = 1: 2 (mol ratio)) was added and the mixture was stirred at room temperature for 2 hours.

After that, SiO _{2 was} added to the coating liquid.
And CeO ₂ were diluted with ethanol so that the total solid content was 8%. In this way, a CeO ₂ sol-containing SiO ₂ coating solution was prepared. This is designated as solution B. Liquid A, which serves as an ultraviolet absorbing layer, was applied on a soda lime glass substrate by a dipping method. Since the coating is performed on only one side of the glass, a polymer film was stuck on the substrate on the side not coated. The liquid A was sealed in a container, the glass substrate was immersed in the coating liquid, and then pulled up at a pulling rate of 150 mm / min.

The coated glass substrate was air-dried for 5 minutes, and 10
After drying at 0 ° C. for 30 minutes, it was baked at 550 ° C. for 30 minutes in an electric furnace. The obtained film was a transparent film without clouding. The film thickness of the obtained sample was measured by a surface roughness meter and found to be 0.5 μm.

B as an outer layer film having an ultraviolet absorbing property
The liquid was applied on the above-mentioned ultraviolet absorbing layer by a dipping method. In this case, as in the case of the ultraviolet absorbing layer, the polymer film was stuck on the substrate on the uncoated side in order to coat only one side. After immersing the glass substrate provided with the ultraviolet absorbing layer in the coating liquid, the pulling rate is 150.
It was pulled up at mm / min. The coated glass substrate was air-dried for 5 minutes, dried at 100 ° C. for 30 minutes, and baked at 550 ° C. for 30 minutes in an electric furnace.

The obtained film was a transparent film without clouding. Liquid B was applied onto a glass substrate at a pulling rate of 150 mm / min, dried and baked under the same conditions, and the film thickness of the obtained single layer film was measured by a surface roughness meter to be 0.2 μm. . The results at this time are shown in Table 1.

Here, the optical characteristics are visible light transmittance (Y
A: JIS Z8722), UV transmittance (Tuv: IS
O9050), T350 (transmittance at 350 nm wavelength), T370 (transmittance at 370 nm wavelength), a · b
(Hunter chromaticity coordinate) was measured. Also, as a chemical resistance test, acid resistance (1% H ₂ SO ₄ 24 hours immersion), alkali resistance (1% NaOH 24 hours immersion), boil test (100 ° C. boiling water 24 hours immersion) were performed, and T350 before and after the test was performed. I examined the change of.

As is clear from the optical characteristics of the sample of Example 1, the sample had a large ultraviolet absorption performance and had a color tone similar to that of the glass substrate. As a result of examining the chemical resistance, the acid resistance, the alkali resistance and the boil test were all good.

[0027]

[Table 1]

(Comparative Example 1) In Example 1, a single layer film in which only the ultraviolet shielding film was formed and no outer layer film was provided was used as a sample of Comparative Example 1. The results at this time are shown in Table 1. This sample was inferior in ultraviolet absorption to Example 1,
In addition, it was shown that it was acid-resistant and showed a large optical change, and was affected by acid.

(Comparative Example 2) An experiment was carried out under the same conditions as in Example 1 except that CeO ₂ colloid sol was not added to the SiO ₂ hydrolyzed solution when the solution B was prepared. The results at this time are shown in Table 1. This sample was good in acid resistance, alkali resistance, and boil test in terms of chemical resistance, but was inferior to Example 1 in ultraviolet shielding performance.

(Comparative Example 3) In Example 1, 600 parts by weight of CeO ₂ colloid sol (SiO ₂ : CeO ₂ = 1: 4) was added to 100 parts by weight of SiO ₂ hydrolyzed solution when the solution B was prepared.
(Mole ratio)) The same experiment as in Example 1 was performed except that the addition was performed. The results at this time are shown in Table 1. This sample had excellent ultraviolet absorption performance, chemical resistance, acid resistance, alkali resistance, and a good boil test. But,
Regarding the color tone, the b value of Hunter chromaticity coordinates was large, and the film appearance became yellowish.

[0031]

Industrial Applicability According to the present invention, it is possible to obtain an ultraviolet absorbing glass having a large ultraviolet absorbing performance and excellent chemical durability. From this, it is useful for glass for vehicles such as automobiles and window glass for houses, which require durability.

Front Page Continuation (72) Inventor Toshifumi Tsujino 3-5-11 Doshumachi, Chuo-ku, Osaka City, Osaka Prefecture Nippon Sheet Glass Co., Ltd. (72) Koichiro Nakamura 3-5-11, Doshomachi, Chuo-ku, Osaka City, Osaka No. Nippon Sheet Glass Co., Ltd.

Claims (2)

[Claims] 1. An ultraviolet absorbing film made of zinc oxide or the like is provided on a glass substrate, and the surface thereof is made of silicon (Si) and cerium (C).
An ultraviolet absorbing glass coated with an outer layer coating of an oxide consisting of two components of e). 2. The outer layer coating according to claim 1, wherein the molar ratio of SiO ₂ to CeO ₂ is within the range of 1.0 to 4.0 with the former being 1 and the film thickness is 0.1 μm or more. The ultraviolet absorbing glass described.