JPH06321577A - Ultraviolet absorbing colored glass - Google Patents

Abstract

PURPOSE:To improve ultraviolet absorption ratio of ultraviolet absorbing colored glass comprising SiO2, Al2O3, Na2O, K2O, CaO, MgO, SO3, CeO2, TiO2, CoO and Fe2O3, by converting a given amount of Fe into Fe<2+>. CONSTITUTION:A mixed raw material is heated, melted, molded into a given shape and annealed to give ultraviolet j!' absorbing glass comprising 65-75wt.% SiO2, 0.1-5wt.% of Al2O3, 10-18wt.% of Na2O, 0-5wt.% of K2O, 5-15wt.% of CaO, 1-6wt.% of MgO, 0.05-1wt.% of SO3, 0.2-1.5wt.% calculated as CeO2 of Ce, 0-1wt.% of calculated as TiO2 of Ti, 0.001-0.006wt.% of CoO and 0.3-1.6wt.% calculated as Fe2O3 of Fe wherein 5-18wt.% of Fe is Fe''. This glass has 488-492 main wavelength measured by a standard source C, 3-4% color purity, >=70% visible light transmittance measured at 3-5mm thickness by a standard source A and <=15% ultraviolet transmittance by ISO.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a UV absorbing colored glass having a high UV absorbing ability and a relatively high visible light transmittance.

[0002]

_2. Description of the Related Art Conventionally, dark blue or green infrared absorbing glass or ultraviolet absorbing glass containing a large amount of FeO, Fe ₂ O ₃ and CeO ₂ is known. A glass that efficiently absorbs ultraviolet rays by depositing semiconductor crystallites is also known.

However, since the former contains a large amount of Fe component, the visible light transmittance is lowered, so that it is particularly unsuitable for vehicle glass, and there is a problem that its use is limited as architectural glass. there were. Further, in the latter, the semiconductor microcrystals are stably generated only in borosilicate glass, and further, the semiconductor microcrystals are reduced in the reducing atmosphere of the float bath in the float process which is a typical plate glass manufacturing method. is there.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide sufficient ultraviolet light by controlling soda lime silica, which is a glass for ordinary buildings or vehicles, as a mother composition and containing various colorants in a controlled manner. It is to provide a glass which has a characteristic of absorbing blue light and transmitting a visible ray sufficiently and exhibiting a blue color tone equivalent to that of conventional architectural or vehicle glass.

[0005]

SUMMARY OF THE INVENTION The present invention is directed to SiO ₂ 6
5 to 75% by weight, Al ₂ O ₃ 0.1 to 5% by weight, Na
₂ O 10-18% by weight, K ₂ O 0-5% by weight, Ca
O 5-15 wt%, MgO 1-6 wt%, SO ₃
0.05 to 1.0 weight%, CeO ₂ in terms of the Ce content
0.2-1.5 wt%, Ti content converted to TiO ₂ 0
1.0 wt%, CoO 0.001 to 0.006 wt%, Fe ₂ O ₃ converted Fe content 0.3 to 1.6 wt%
It is an ultraviolet absorbing colored glass having a composition essentially consisting of 5 to 18% by weight of Fe ₂ O ₃ converted Fe ₂ ⁺ .

The reasons for limiting the above components will be described below. Si
If the content of O ₂ is less than 65%, the weather resistance becomes poor,
If it exceeds 75%, devitrification tends to occur.

If the content of Al ₂ O ₃ is less than 0.1%, the water resistance is lowered, and if it is more than 5%, the solubility is lowered.

Na ₂ O and K ₂ O are components that promote the dissolution of the raw materials. If the content of Na ₂ O is less than 10%, the effect is small, and if it is more than 18%, the weather resistance is deteriorated.
If the content of K ₂ O is more than 5%, the cost will be high.

CaO and MgO are components which accelerate the dissolution of the raw materials and improve the weather resistance, but when the content of CaO is less than 5%, the above-mentioned effect is small, and when it is more than 15%, devitrification tends to occur. If the content of MgO is less than 1%, the above effect cannot be obtained, and if it is more than 6%, devitrification tends to occur.

SO ₃ is a fining agent. If the content of SO ₃ is less than 0.05%, there is no clarification effect, and if it is more than 1.0%, bubbles of SO ₂ remain in the glass.

The Ce component converted to CeO ₂ is mainly composed of Ce.
There are ³⁺ and Ce ⁴⁺ , both of which are effective in absorbing ultraviolet rays. If the Ce content calculated as CeO ₂ is less than 0.2%, the effect is small, and if it is more than 1.5%, the effect of visible light absorption is large. In addition, since Ce having absorption in the near-ultraviolet region is Ce ³⁺ , CeO ₂ is replaced with Ti.
_By reducing with ₂ O ₃ , the effect of absorbing near-ultraviolet rays can be further enhanced.

Although the Ti content calculated as TiO ₂ is not an essential component, its inclusion can increase the ultraviolet absorption capacity. The content of Ti converted to TiO ₂ is 1.0%
If the amount is larger, the dominant wavelength becomes longer and yellow coloring occurs.

In addition to the above components, the following trace components are contained. That is, this glass has a blue color,
CoO 0.001 to 0.006%, Fe ₂ O _3-converted Fe content from 0.3 to 1.6%, and Fe ₂ O ₃ 5 to 18 wt% of the terms the Fe content is Fe ^2+.

When the content of CoO is less than 0.001%, the dominant wavelength becomes too long and the color tone becomes yellow, and 0.006
If it is more than%, the dominant wavelength becomes too short and a glass exhibiting a blue color cannot be obtained.

When the content of Fe ₂ O ₃ is less than 0.3%, the dominant wavelength becomes too short, and when it is more than 1.6%, the dominant wavelength becomes too long, and neither blue glass can be obtained.

Of the total Fe content expressed as Fe ₂ O ₃ , FeO, that is, Fe ^2+, is in the range of 5 to 18%. Fe exists in the glass in the state of Fe ²⁺ and Fe ³⁺ , but the one existing in the state of Fe ³⁺ has an absorption band in the near-ultraviolet region and is a component that absorbs ultraviolet rays. If Fe ²⁺ is less than 5% of the total Fe content, the ultraviolet absorption capacity is low
²⁺ is S0 ₃ used as often as fining agent than 18% is reduced, it reduces the fining effect, also amber color is likely to occur.

In the above composition range, the dominant wavelength measured by the standard light source C is 488 to 492 nm, and the color purity is 3
A blue glass having a content of ˜4% is particularly preferable for architectural purposes, etc., since it has an excellent ability to absorb ultraviolet rays and exhibits the same color tone as that of conventionally used glass.

Furthermore, having the above-mentioned dominant wavelength and color purity,
A glass having a thickness of 3 to 5 mm, which has a visible light transmittance of 70% or more measured by a standard light source A and an ultraviolet transmittance of 15% or less specified by ISO, is particularly preferable as a vehicle glass exhibiting a blue color. It is easy to recognize external objects,
This is because the interior is not deteriorated, it is lightweight, and it has the same color tone as that of blue-colored vehicle glass that has been conventionally used.

[0019]

In the present invention, Fe ₂ O ₃ , CeO ₂ and TiO ₂ in the soda lime silica system have absorption ability in the ultraviolet region, and are considered to have the effect of reducing the ultraviolet transmittance of the glass.

Fe ³⁺ has absorption from the ultraviolet region of 360, 380 and 420 nm to the visible region in the near ultraviolet region, and Ce ³⁺ , C
e ⁴⁺ has ultraviolet absorption bands centered at 315 nm and 210 nm, respectively. Further, TiO ₂ is the above-mentioned C
It is also known that there is a charge transfer absorption band with Fe ²⁺ in addition to the reducing action of eO ₂ , and it is considered that ultraviolet rays are efficiently absorbed by these phenomena.

[0021]

Example: The prepared batch is melted in an atmosphere (O ₂ concentration of about 2.0%) which is considered to be close to that of a real kiln, and an appropriate molding is performed.
By gradually cooling, a glass having the composition (unit: wt%) described in the upper column of Table 1 was obtained. This glass had a blue color. Then, for this glass, Fe ²⁺ / total Fe
[Namely, Fe ²⁺ / (Fe ²⁺ + Fe ³⁺ )] (unit: wt%), visible light transmittance (unit:%) in terms of thickness of 5 mm,
Solar heat transmittance (unit:%) in terms of thickness 5 mm, thickness 5 m
m transmittance of ultraviolet ray (unit:%), thickness of 5 mm converted wavelength of 350 nm (unit:%), thickness of 5 mm converted main wavelength (unit: nm), thickness of 5 mm converted color purity (unit:%) :%) Was measured, and the results are also shown in the lower column of Table 1. Examples 1 to 5 are examples and Examples 6 to 7 are comparative examples.

As raw materials, silica sand, feldspar, dolomite,
Soda ash, mirabilite, ferric oxide, cerium oxide, titanium dioxide, and coke were used. Further, the visible light transmittance, the dominant wavelength, and the color purity are obtained according to JIS R-3106,
The ultraviolet transmittance was determined according to ISO-9050.

[0023]

[Table 1]

As is clear from Table 1, the glass according to the present invention has a blue color tone and is excellent in ultraviolet absorbing ability.

[0025]

Since the glass of the present invention has a high visible light transmittance and sufficiently absorbs ultraviolet rays, it can prevent deterioration of interior materials and sheets due to ultraviolet rays and prevent sunburn of persons inside. Therefore, it seems to be particularly useful as a window glass for buildings and vehicles. In addition, since it can be colored under the same level of redox conditions as ordinary colored plate glass, the action of a fining agent such as Glauber's salt is also effective. Therefore, it is considered that the conventional glass melting apparatus, for example, the fining action in the float glass manufacturing process can be performed under the same conditions as usual. Also, since the concentration level is the same level as that of ordinary colored flat glass, it is possible to change the substrate by a normal operation.

Claims (3)

[Claims] 1. SiO ₂ 65 to 75% by weight, Al ₂ O ₃ 0.1 to 5% by weight, Na ₂ O 10 to 18% by weight, K ₂ O 0 to 5% by weight, CaO 5 to 15% by weight, MgO 1 to 6% by weight, SO ₃ 0.05 to 1.0% by weight, CeO ₂ converted Ce content 0.2 to 1.5% by weight, TiO ₂ converted Ti content 0 to 1.0% by weight, CoO 0.001 to 0.006% by weight, Fe content converted to Fe ₂ O ₃ has a composition essentially consisting of 0.3 to 1.6% by weight, and 5% of Fe content converted to Fe ₂ O ₃ ~ 18 wt% Fe ²⁺ UV absorbing colored glass. 2. The dominant wavelength measured by the standard light source C is 488.
The ultraviolet absorbing colored glass according to claim 1, which has a color purity of ˜492 nm and a color purity of 3 to 4%. 3. The thickness is 3 to 5 mm, the visible light transmittance measured by the standard light source A is 70% or more, and the ISO
The ultraviolet-absorptive colored glass according to claim 2, which has an ultraviolet transmittance of 15% or less as defined in (3).