JPH05201746A - Ultraviolet cutoff glass - Google Patents

Abstract

PURPOSE:To give sharp absorption property with a narrow wavelength inclined width where light of wavelengths smaller than an arbitrary one is almost completely cut off and light of wavelengths larger than that almost completely transmitted and to extremely decrease the change in transmission property even when radiated with strong ultraviolet rays. CONSTITUTION:The ultraviolet cutoff glass consists of (a) 20-85wt.% SiO2, (b) 2-75wt.% B2O3, (c) <=15wt.% Al3O3, (d) <=30wt.% alkaline metal oxide consisting of at least one of LiO2, Na2O, K2O, Rb2O and CS2O, (e) <=10wt.% at least one of MgO, Cab, ZnO, Bad, SrO and PbO and (f) 0.05-15wt.% at least one of copper halogenides and satisfies the conditions (1) that <=0.5wt.% K2O exists in alkaline metal oxides and/or (2) that 0.5-5wt.% at least one of ZnO or BaO is included.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an ultraviolet blocking glass.

[0002]

2. Description of the Related Art Conventionally, colored glass has been used as a sharp-cut glass filter for photography for the purpose of absorbing light in the ultraviolet or visible range. Such colored glass is obtained by doping glass with a microcrystal of CdS, CdSe or CdSSe which is a II-VI group semiconductor, and the microcrystal is a portion of a certain wavelength region of light transmitted through the glass. It serves its purpose by absorbing.

However, the Cd compound as described above is a toxic substance and poses a serious risk to the health of workers in manufacturing processes such as batch preparation, transportation and melting. In addition, it is difficult to treat Cd compounds contained in wastewater and waste produced when glass is subjected to processing such as cutting, grinding and polishing.
It also has pollution problems. For example, according to the Water Pollution Control Act, the limit of the allowable content of Cd and its compounds in discharged water is 0.1 mg / l. For these reasons, a large amount of equipment such as pollution treatment equipment and sludge treatment equipment is required to produce the glass, and Cd compound dove glass cannot be said to be an appropriate material. In addition, the glass in which CdS, CdSe, or CdSSe microcrystals are doped in the transmittance characteristic has a wide wavelength inclination width (Δλ) defined by JIS B7113, and it is hard to say that the absorption is sharp.

For the same purpose, multilayer film-coated glass is used in addition to the glass doped with the Cd compound. In this glass, a multilayer film is vapor-deposited on glass that does not absorb light in the ultraviolet region or the visible region, and light in a constant wavelength region is blocked by utilizing light interference between the multilayer films. However, the light blocking effect of the multilayer coating glass depends on the incident angle, and the light in the constant wavelength region is blocked only by the incident light in a constant direction with respect to the glass.
The intended effect cannot be obtained for incident light from other angles. Also, the wavelength tilt width of the tilt region is wide,
It is hard to say a sharp cutoff.

[0005]

DISCLOSURE OF THE INVENTION As described above, the present inventor has developed a new glass having a more excellent light blocking effect without using the Cd compound and the harmful substances which have been problems in the conventional colored glass. I have been earnestly researching to obtain it. As a result, copper halide microcrystals, which are Group I-VII semiconductors, were doped into the glass and a specific amount of K ₂ O was added.
Or a specific amount of at least one of ZnO and BaO is mixed, light with a certain wavelength or less is almost completely blocked, and light with a certain wavelength or more is almost completely transmitted. The inventors have found that a glass having absorption characteristics and having very little change in transmission characteristics even when irradiated with strong ultraviolet rays can be obtained, and completed the present invention.

That is, the present invention provides the following ultraviolet blocking glass.

(I) b) SiO ₂ 20 to 85% by weight,
(B) B ₂ O _{3 2 to} 75% by weight, c) Al ₂ O ₃ 15% by weight or less, d) an alkali composed of at least one of Li ₂ O, Na ₂ O, K ₂ O, Rb ₂ O and Cs ₂ O. 1 to 30% by weight of metal oxide, K _{2 in} alkali metal oxide
0.5% by weight or more of O, e) MgO, CaO, ZnO,
10% by weight of at least one of BaO, SrO and PbO
The following, and f) at least one kind of copper halide 0.0
An ultraviolet blocking glass containing 5 to 15% by weight (hereinafter referred to as "first invention glass of the present application").

(II) b) SiO ₂ 20 to 85% by weight,
(B) B ₂ O _{3 2 to} 75% by weight, c) Al ₂ O ₃ 15% by weight or less, d) an alkali composed of at least one of Li ₂ O, Na ₂ O, K ₂ O, Rb ₂ O and Cs ₂ O. An ultraviolet-blocking glass containing 30% by weight or less of a metal oxide, (e) 0.5 to 5% by weight of at least one of ZnO and BaO, and (f) 0.05 to 15% by weight of at least one of a copper halide ( Hereinafter, it is referred to as "the second invention glass of the present application").

(III) b) SiO ₂ 20 to 85% by weight,
(B) B ₂ O _{3 2 to} 75% by weight, c) Al ₂ O ₃ 15% by weight or less, d) an alkali composed of at least one of Li ₂ O, Na ₂ O, K ₂ O, Rb ₂ O and Cs ₂ O. 1 to 30% by weight of metal oxide, K _{2 in} alkali metal oxide
UV shielding glass containing 0.5% by weight or more of O, e) 0.5 to 5% by weight of at least one of ZnO and BaO, and f) at least 0.05 to 15% by weight of at least one type of copper halide. (Hereinafter, referred to as “the third invention glass of the present application”).

On the basis of the above glass composition, the glass of the present invention is capable of transmitting light of a specific wavelength and exhibiting a desired coloring effect as a result of doping copper halide crystallites into the glass. it can. Further, the glass of the present invention has very little change in transmission characteristics even when irradiated with ultraviolet rays, visible rays, and near-infrared rays, and particularly when irradiated with strong ultraviolet rays using a metal halide lamp or the like as a light source. It has a characteristic that the change in transmission characteristics is very small and the unique light transmission characteristics can be maintained.

In the glass component of the glass of the present invention, each component other than copper halide is not particularly different from various components conventionally used as glass components, and SiO 2
₂ , B ₂ O ₃ , Al ₂ O ₃ , Li ₂ O, Na ₂ O, K ₂
O, Rb ₂ O, Cs ₂ O, MgO, CaO, ZnO, B
aO, SrO, PbO, ZrO ₂ , La ₂ O ₃ , Y ₂ O
₃ , Ta ₂ O ₃ , Gd ₂ O _{3 and the} like.

Si which is the component a) of the first invention glass of the present application
O ₂ is a main component that constitutes the glass network, and it is preferable to contain O ₂ in an amount of about 20 to 85% by weight, preferably about 50 to 71% by weight, based on all components. If the content ratio exceeds 85% by weight, the meltability of the glass deteriorates, whereas if it is less than 25% by weight, the chemical durability is insufficient and discoloration is caused, which is not preferable.

B ₂ which is the (b) component of the first invention glass of the present application
O ₃ is a component that improves the meltability of glass and constitutes a glass network at a certain composition ratio, and is 2 to 7 out of all components.
It is preferable that the content is about 5% by weight, preferably about 12 to 27% by weight. If the content ratio exceeds 75% by weight, the chemical durability of the glass becomes insufficient, whereas if it is less than 2% by weight, the light transmission characteristics which are the object of the present invention cannot be obtained and the melting property of the glass deteriorates.

Al which is the component (c) of the first invention glass of the present application
₂ O ₃ suppresses devitrification of glass and improves chemical durability, and it is preferable to contain ₂ O ₃ in an amount of about 15% by weight or less, preferably about 1 to 10% by weight, based on all components. If the content ratio exceeds 15% by weight, the meltability of glass will be significantly deteriorated.

Li which is the component (d) of the first invention glass of the present application
Alkali metal oxides selected from ₂ O, Na ₂ O, K ₂ O, Rb ₂ O and Cs ₂ O have the effect of improving the meltability of glass. It is preferable that the content is about 30 to 30% by weight, preferably about 5 to 15% by weight. If the content ratio exceeds 30% by weight, the chemical durability of glass becomes insufficient. Of these alkali metal oxides, K ₂ O is an essential component, and is 0.5% by weight in the alkali metal oxides.
Or more, preferably 30% by weight or more. Due to the presence of such an amount of K ₂ O, there is very little change in the transmission characteristics even when irradiated with strong ultraviolet rays.

Mg which is the component (e) of the first invention glass of the present application
O, CaO, ZnO, BaO, SrO and PbO have the effect of improving the chemical durability of the glass, and one or more of them are contained in an amount of about 10% by weight or less, preferably 0.1 It is preferable that the glass be contained in an amount of about 5% by weight, and if the content ratio exceeds 10% by weight, the meltability of the glass deteriorates.

Examples of the copper halide which is component (f) of the glass of the first invention of the present application include CuCl, CuBr, and CuI.
Etc., and one or more of these may be doped into the glass of the present invention. These copper halides act as an absorption colorant having an arbitrary wavelength in the ultraviolet ray or visible region, and in the present invention, the content is about 0.05 to 15% by weight, preferably about 0.3 to 8% by weight in the total composition of the glass. To be included. By setting the content ratio in the glass within the above range, light having a certain wavelength of 350 to 450 nm or less is almost completely blocked, light having a longer wavelength than that is almost completely transmitted, and the wavelength inclination width Transmission characteristics with narrow and sharp absorption characteristics are obtained. When the content ratio is less than 0.05% by weight, the above-mentioned advantageous effects cannot be obtained, and when it exceeds 15% by weight, devitrification occurs, which is not preferable.

The components a) to c) and f) of the second invention glass of the present application are the same as those of the first invention glass of the present application.

Li which is the component (d) of the second invention glass of the present application
Alkali metal oxides selected from ₂ O, Na ₂ O, K ₂ O, Rb ₂ O and Cs ₂ O have the effect of improving the meltability of the glass. It is preferable that the content is about not more than about 5% by weight, preferably about 5 to 15% by weight. If the content ratio exceeds 30% by weight, the chemical durability of glass becomes insufficient.

Zn which is the component (e) of the second invention glass of the present application
O and BaO have the effect of improving the chemical durability of the glass, and the presence of this component results in very little change in the transmission characteristics even when irradiated with strong ultraviolet rays. At least one of these is 0.5 to 5 in all ingredients
It is good to contain it so that it may be about wt%, preferably about 1.5 to 4 wt%.

In the third invention glass of the present application, the components a) to d) and f) are the same as those of the first invention glass of the present application.

Zn which is the component (e) of the third invention glass of the present application
O and BaO have the effect of improving the chemical durability of the glass, as in the case of the second invention glass of the present application, and the presence of this component causes a great change in the transmission characteristics even when irradiated with strong ultraviolet rays. Less. It is preferable that at least one of them is contained in an amount of about 0.5 to 5% by weight, preferably about 1.5 to 4% by weight, based on all components.

In the glass of the third invention of the present application, by satisfying the above conditions (d) and (e) at the same time, the change of the transmission characteristics is particularly small even when irradiated with strong ultraviolet rays.

In the first to third invention glasses of the present application, if necessary, at least one selected from ZrO ₂ , La ₂ O ₃ , Y ₂ O ₃ , Ta ₂ O ₃ and Gd ₂ O ₃ should be contained. This can improve the chemical durability of the glass. One or more of these components are contained in about 10% by weight or less, preferably 0.1 to 5% by weight, based on all components.
It is preferable to contain it in a certain amount, and if the content ratio exceeds 10% by weight, the devitrification becomes strong and the stability of the glass is adversely affected.

In order to produce the glass of the present invention, the raw materials may be blended so as to have the above-mentioned predetermined composition, and the glass may be treated according to a conventional glass production method. For example, the raw materials are blended so as to have a predetermined composition, melted at a temperature of about 1200 to 1500 ° C., stirred, clarified, poured into a mold, and during or after cooling, at a temperature of about 450 to 700 ° C. .1
The glass of the present invention can be obtained by subjecting the glass of the present invention to heat treatment for about 5 hours, and then performing processing such as cutting and polishing. In the above production, in order to mix the fine crystals of the copper halide in the glass, copper halide or a copper compound such as a copper source which is a raw material thereof, a copper compound such as a copper halide and the halogen together with the copper source are used. A halogen source capable of forming copper halide, such as lithium halide, sodium halide, potassium halide, rubidium halide, and cesium halide, and an alkali halide compound are mixed with other raw materials so as to have a predetermined composition. Good. As the components other than the copper halide, conventional glass raw materials such as oxides, carbonates, hydroxides and the like that can result in the components can be used as they are. The cooling is performed at 10 to 100 ° C./hr so that the glass is not thermally distorted.
Degree, preferably about 30 to 50 ° C / hr, and heating about 10 to 100 ° C / hr, preferably 30 to 70 ° C / hr.
It is important to perform at a slow speed of about hr. The size of the copper halide crystal is determined by these speeds and heating times. In the present invention, it is preferable to adjust the size of this crystal to a diameter of about 0.1 to 10 nm. The melting step is preferably performed in a neutral or reducing atmosphere so that Cu ions become Cu ⁻ during that time. In the refining step, As ₂ O ₃ and Sb ₂ O are used as refining agents.
_You can use ₃ etc.

[0026]

The glass of the present invention can exert the following remarkable effects.

(1) In the light in the wavelength range of 250 to 800 nm, the light having an arbitrary wavelength of 350 to 450 nm or less is almost completely blocked, and the light having a longer wavelength than that is almost completely transmitted, and the wavelength inclination width is It can have narrow and sharp absorption characteristics.

(2) Content of copper halide in glass,
The above arbitrary wavelength can be controlled by the type and combination.

(3) The above transmission characteristics do not change even when irradiated with ultraviolet rays, visible rays and near infrared rays. In particular, even when strong ultraviolet rays are emitted from a metal halide lamp or the like as a light source, the change in transmission characteristics is very small, and the unique light transmission characteristics can be maintained.

(4) Unlike conventional colored glass, it is safe in manufacturing and does not require special attention to handling and disposal. Therefore, it is manufactured by general glass manufacturing equipment without adding any processing equipment. Can be done.

[0031]

EXAMPLES The following examples are given to further clarify the features of the present invention. Example 1 Raw materials were prepared so that a glass having the composition shown in Table 1 below was obtained, and melted in an alumina crucible for 2 hours at the temperature shown in Table 1. The melt was poured onto a carbon plate, and the gradually cooled glass was heat-treated at the temperature and time shown in Table 1 to obtain the target glass. Cu ₂ O was used as the copper source, and sodium halide or potassium halide was used as the halogen source.

The melting was performed in a neutral or reducing atmosphere, and the cooling rate and the heating rate in the heat treatment step were 30 ° C./hr and 50 ° C./hr, respectively.

In any of the compositions, melting and molding could be easily carried out, and the obtained glass had excellent chemical durability. Further, in the above refining process, even if As ₂ O ₃ and Sb ₂ O ₃ were used as refining agents, the transmission characteristics of the obtained glass did not change.

[0034]

[Table 1]

Next, the degree of decrease in transmittance in the visible region due to strong ultraviolet irradiation was measured using samples obtained by polishing these glasses to a thickness of 2 mm. A 400 W metal halide lamp was used as the ultraviolet light source, and the distance between the light source and the glass was 10 cm, and irradiation was performed for 10 hours. 540 is used to judge the degree of decrease in transmittance in the visible range due to ultraviolet rays.
It was performed by comparing the transmittance in nm before and after irradiation with ultraviolet rays. The results are shown in Table 2.

Table 2 Glass No 1 2 3 4 5 6 Reduction of transmittance (%) 5.5 7.0 7.0 3.0 3.0 3.0 8.0 From the above results, the glass of the present invention is strong. It can be seen that the decrease in transmittance is very small even when irradiated with ultraviolet rays.

Test Example The spectral transmission characteristics of the glass of Example 1 were 300 to 800 n.
Tested by irradiating with light in the wavelength range of m. The result is shown in FIG. From FIG. 1, it is clear that the glass of the present invention effectively blocks light in the ultraviolet region and has a sharp absorption characteristic with a narrow wavelength gradient width.

[Brief description of drawings]

FIG. 1 is a graph showing transmittance.

Claims (3)

[Claims] 1. A) 20 to 85% by weight of SiO ₂ , B) B ₂
O _{3 2 to} 75% by weight, c) Al ₂ O ₃ 15% by weight or less,
D) Li ₂ O, Na ₂ O, K ₂ O, Rb ₂ O and Cs ₂
Alkali metal oxides 1-3 containing at least one of O
0% by weight, and K ₂ O in an alkali metal oxide of 0.
5 wt% or more, e) MgO, CaO, ZnO, BaO,
10% by weight or less of at least one of SrO and PbO, and f) at least one of copper halide 0.05 to 15
A UV-blocking glass containing 100% by weight. 2. A) 20 to 85% by weight of SiO ₂ , B) B ₂
O _{3 2 to} 75% by weight, c) Al ₂ O ₃ 15% by weight or less,
D) Li ₂ O, Na ₂ O, K ₂ O, Rb ₂ O and Cs ₂
30% by weight or less of an alkali metal oxide containing at least one of O, e) at least one of ZnO and BaO.
An ultraviolet blocking glass containing 5 to 5% by weight and (f) at least 0.05 to 15% by weight of a copper halide. 3. A) 20 to 85% by weight of SiO ₂ , B) B ₂
O _{3 2 to} 75% by weight, c) Al ₂ O ₃ 15% by weight or less,
D) Li ₂ O, Na ₂ O, K ₂ O, Rb ₂ O and Cs ₂
Alkali metal oxides 1-3 containing at least one of O
0% by weight, and K ₂ O in an alkali metal oxide of 0.
An ultraviolet blocking glass containing 5% by weight or more, (f) at least 0.5 to 5% by weight of ZnO and BaO, and (f) at least 0.05 to 15% by weight of copper halide.