JP2000247679A - Ultraviolet ray and infrared ray absorbing low transmissive glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide glass having green-gray-based color tone close to neutral color and having low transmittance to visible light, all sun light and ultraviolet rays, which is useful for reduction in thickness or in weight of the windows of automobiles and buildings, especially, the windows for privacy protection of passenger cars. SOLUTION: The glass has a base glass composition of, by weight, 65-80% SiO2, 0 to 5% Al2O3, 0 to 10% MgO, 5 to 15% CaO(MgO+CaO=5 to 15%), 10 to 18% Na2O, 0 to 5% K2O, (Na2O+K2O=10 to 20%) and 0 to 5% B2O3, and contains, as colorant components, total iron oxide (T-Fe2O3) of >1.0 and <=1.9% expressed in terms of Fe2O3, >0.02 and <=0.05% CoO, 0 to 0.003% Se, 0.7 to 2.0 TiO2 and 0 to 0.2% NiO. The glass has a transmittance to visible light of <=18%, measured using A-light source, a transmittance to whole sun light of <=25% and a transmittance to ISO-ultraviolet ray of <=7%, each value being expressed in terms of the thickness of 4 mm of the glass.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass having a low transmittance for ultraviolet and infrared rays. Specifically, it has a green-gray color tone close to neutral color, and has a low visible light transmittance, a low total sunlight transmittance, and a low ultraviolet light transmittance. The present invention relates to an ultraviolet-ray-absorbing and low-transmitting glass useful as a glass for protecting a privacy of a passenger car, and particularly useful for reducing the thickness and weight of the glass.

[0002]

2. Description of the Related Art In recent years, from the viewpoint of demand for prevention of deterioration of interior materials due to upgrading of interior materials of automobiles and reduction of cooling load,
Various glasses having an ultraviolet and infrared absorption capability have been proposed as window glasses for automobiles. Of these, glass having relatively low visible light transmittance is preferably used for the rear window glass of a vehicle from the viewpoint of privacy protection. Such glasses include the following.

[0003] For example, the dark gray infrared absorbing glass disclosed in Japanese Patent Publication No. 7-29813 is 1.00 to 1.7% Fe ₂ O _{3 in} soda-lime-silica glass by weight.
(Total iron), at least 0.27% FeO, 0.002
-0.005% Se, 0.01-0.02% CoO
A coloring agent consisting of This glass is 3.9m
It has a light transmission of 32% or less and a total solar infrared transmission of less than 15% at a thickness of m.

The dark gray glass disclosed in Japanese Patent Application Laid-Open No. 8-157232 is a soda-lime-silica glass expressed as 0.8-1.4% by weight of Fe ₂ O ₃ (total). Fe), FeO of 0.21% or less, 0.05-1.0%
TiO ₂ , 0.02-0.05% CoO, 0.00
It contains a colorant consisting of 0.05 to 0.015% Se.

The neutral dark gray glass disclosed in claim 25 of US Pat. No. 5,393,593 is 66-75% SiO _2, 10-20% Na ₂ O, CaO 5
-15%, MgO 0-5%, Al ₂ O ₃ 0-5%, K ₂ O
A base glass component consisting of 0 to 5%, and 1.00 to 2.2%
% Fe ₂ O ₃ (total iron), at least 0.20% Fe
O, 0.0005-0.005% Se, 0.010
0.030% of a colorant comprising CoO. The glass has a light transmission of less than 35% at a thickness of 3.9 mm and a total solar infrared transmission of less than 20%.

The glass disclosed in Japanese Patent Publication No. 8-506314 has a ferrous content in soda-lime-silica glass calculated by the following equation, and FeO (% by weight) ≧
0.007+ (optical density−0.036) /2.3% by weight
Containing 0.25 to 1.75% of Fe ₂ O ₃ ,
e, Co ₃ O ₄ , Nd ₂ O ₃ , NiO, MnO, V ₂ O ₅ , C
By selecting one or more from the group consisting of eO ₂ , TiO ₂ , CuO and SnO, it is colored in an intermediate color. This glass has a visible light transmittance of 32% or more at a thickness of 4 mm, an ultraviolet transmittance of 25% or less, a solar direct heat transmittance of at least 7% lower than the visible light transmittance, and a dominant wavelength of preferably It is less than 570 nm. Some of this embodiment can be used as privacy glass.

[0007] The dark gray infrared absorbing glass disclosed in Japanese Patent Publication No. 7-29813 and the Japanese Patent Application Laid-Open No. 8-1572.
The dark gray glass disclosed in No. 32 uses a large amount of Se in order to obtain a preferable color tone. Se
Since is highly toxic and very volatile, the use of a large amount of Se is undesirable because it has a large effect on the environment.

[0008] Also, the aforementioned US Patent No. 5,393,593.
The neutral dark gray glass disclosed in the above publication also has a high Se content, which is not preferable from the viewpoint of environmental protection. Also, a high FeO content is preferable from the viewpoint of heat ray absorption,
Since FeO selectively absorbs infrared rays in the wavelength range of 1000 to 1200 nm, when it is produced in a normal melting furnace, it absorbs the most efficient part in the luminance distribution of the flame. It is not preferable because it causes a reduction and causes various disadvantages.

Although the glass having the low visible light transmittance described above is excellent in terms of privacy protection, it has a disadvantage that it is difficult to see the outside scene through the glass from inside the passenger car. On the other hand, a glass having a medium transmittance can satisfy both privacy protection and safety to some extent. At present, these two types of glass are properly used depending on the use site and the situation of the passenger car.

[0010] The above-mentioned glasses are essentially free of Ni and have a high concentration of Se to obtain desired optical characteristics.

Among the glasses disclosed in the above-mentioned Japanese Patent Publication No. Hei 8-506314, those which can be used for privacy protection are Ni, Se, and Co as described in the text.
Intermediate color tone is obtained by including all the coloring agents of
Since the content is small, it is necessary to add a large amount of Se.

In order to solve the above-mentioned problems of the prior art, Se
Can be contained in a much smaller amount than conventionally required, or a desired bluish green or deep greenish color tone close to a desired neutral color can be obtained without using it at all. In order to provide an ultraviolet-ray-absorbing low-transmission glass having a visible light transmittance, a low ultraviolet transmittance, and a low total sunlight transmittance, the present applicant has previously described 65 to 65% by weight.
80% SiO ₂ , 0 to 5% Al ₂ O ₃ , 0 to 10% MgO, 5 to 15% CaO (however, MgO and CaO
Total amount is 5-15%), 10 to 18% of Na ₂ O, 0 and
５5% K ₂ O (however, the total amount of Na ₂ O and K ₂ O is 1
0-20%), and a base glass composition comprising 0 to 5% B ₂ O _3, as coloring components, 1.2 to 2.2% of Fe ₂
O total iron oxide in terms of _{3 (T-Fe 2 O 3} ), 0.001
We have proposed an ultraviolet-ray-absorbing low-transmission glass made of -0.03% CoO, 0-0.0008% Se, and 0-0.2% NiO (Japanese Patent Application Laid-Open No. 10-114540).

[0013]

Problems to be Solved by the Invention
No. 40, the ultraviolet-ray-absorbing low-transmission glass provides a relatively low visible-light transmittance, an ultraviolet-ray-absorbing low-transmission glass having a low total sunlight transmittance and a low ultraviolet transmittance. The visible light transmittance and the total sunlight transmittance achieved by the ultraviolet and infrared absorbing low-transmission glass are such that the visible light transmittance (YA) of the glass converted to a thickness of 4 mm measured using a light source A is 23 to 50. %, And the total sunlight transmittance (TG) is about 20 to 35%.

On the other hand, in recent years, in order to reduce the environmental burden caused by automobiles, development of a fuel-efficient system, reduction of the weight of a vehicle body, and the like have been promoted. In the past, weight reduction of a car body was mainly promoted by thinning the steel plate of the body to increase the strength.However, it has been desired to make the car body even lighter by thinning the window glass. Have been. However, if the thickness of the glass is reduced, the visible light transmittance and the total sunlight transmittance increase, so that the thickness and thickness of the automotive window glass are sufficiently low even if the thickness is reduced even if the thickness is reduced. There is a demand for an ultraviolet-ray-absorbing low-transmission glass capable of obtaining a visible light transmittance and a total sunlight transmittance.

[0015] In the ultraviolet and infrared absorbing low transmission glass disclosed in JP-A-10-114540, 3.1 to 5 m
m, the visible light transmittance of the glass at any thickness is 1
0-25%, and the total sunlight transmittance is 10-35%
UV and infrared absorbing low transmission glass can be realized,
In order to reduce the thickness and weight of the above-mentioned window glass for automobiles, recently, as described above, the visible light transmittance is 10 to 25% and the total sunlight transmittance is 1 with a thickness of, for example, 2.8 mm.
There is a need for an ultraviolet- and infrared-absorbing low-transmission glass having a low visible light transmittance and a low total sunlight transmittance that achieves 0 to 35%.

As described above, when the thickness is 2.8 mm, the visible light transmittance is 10 to 25%, and the total sunlight transmittance is 10 to 35%.
In order to obtain a glass having the following formula, the visible light transmittance when converted to a thickness of 4 mm is 5 to 15%, and the total sunlight transmittance is 5 to 5%.
Must be 25%.

The present invention has been made in view of the above conventional situation, and has a green-gray color tone close to a neutral color, low visible light transmittance, low total sunlight transmittance, and low ultraviolet light. An object of the present invention is to provide an ultraviolet-ray-absorbing low-transmission glass useful as a window glass for automobiles and buildings, particularly as a glass for protecting privacy of a passenger car, and particularly useful for thinning and reducing the weight thereof, since it has a transmittance.

[0018]

Means for Solving the Problems] ultraviolet and infrared radiation absorbing and low transmission glass of the present invention, in% by weight, 65% to 80% of SiO _2, 0 to 5% of Al ₂ O _3, 0-10% MgO,
5-15% of CaO (provided that the total amount of MgO and CaO is 5-15%), 10 to 18% of Na ₂ O, 0 to 5% of the K ₂ O (provided that Na ₂ O and K ₂ O 10-20
%) And a basic glass composition comprising 0 to 5% of B ₂ O _3, and a coloring component of more than 1.0% and not more than 1.9% of F
Total iron oxide (T-Fe ₂ O ₃ ) converted to e ₂ O ₃ , 0.02
%, Greater than 0.05% CoO, 0 to 0.003% of Se, 0.7 to 2.0% of TiO _2, and 0 to 0.2%
The visible light transmittance (YA) of a glass made of NiO and having a thickness of 4 mm measured using a light source A is 1
8% or less, total sunlight transmittance (TG) is 25% or less, and ultraviolet transmittance (TUV) specified in ISO
Is 7% or less.

In the ultraviolet and infrared ray absorbing and low-transmitting glass of the present invention, the visible light transmittance is reduced by increasing the CoO content in the coloring components of the glass composition described in JP-A-10-114540. In order to eliminate the bluish color caused by increasing the CoO content,
By adding iO ₂ , the visible light transmittance (YA) of glass converted to a thickness of 4 mm is 18% or less, the total sunlight transmittance (TG) is 25% or less, and the ultraviolet transmittance (TUV) specified in ISO ) Realizes a glass having low visible light transmittance, low total sunlight transmittance and low ultraviolet transmittance of 7% or less.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The reasons for limiting the ultraviolet and infrared absorbing low transmission glass composition of the present invention will be described. However, the following compositions are expressed by weight%.

SiO ₂ (silica) is a main component forming a glass skeleton. If the SiO ₂ content is less than 65%, the durability of the glass decreases, and if it exceeds 80%, melting of the glass becomes difficult.

Al ₂ O ₃ is a component for improving the durability of the glass, but if it exceeds 5%, melting of the glass becomes difficult. The preferred range of Al ₂ O ₃ is 0.1 to 2%.

MgO and CaO are used to improve the durability of the glass and to adjust the devitrification temperature and viscosity during molding. When the content of MgO exceeds 10%, the devitrification temperature increases. If the content of CaO is less than 5% or more than 15%, the devitrification temperature rises. If the total of MgO and CaO is less than 5%, the durability of the glass decreases, and if it exceeds 15%, the devitrification temperature increases.

Na ₂ O and K ₂ O promote melting of the glass. If the content of Na ₂ O is less than 10% or the total of Na ₂ O and K ₂ O is less than 10%, the dissolution accelerating effect is poor and Na ₂ O
Exceeds 18% or the total of Na ₂ O and K ₂ O is 2%
If it exceeds 0%, the durability of the glass decreases. If the amount of K ₂ O is large, the cost increases, so it is desirable to keep K ₂ O at 5% or less.

B ₂ O ₃ is a component used for improving the durability of glass or as a melting aid, but also has a function of enhancing absorption of ultraviolet rays. If it exceeds 5%, the transmittance in the ultraviolet region falls to the visible region, and the color tone tends to take on a yellow tint. In addition, inconvenient molding occurs due to volatilization of B ₂ O _{3 and} the like, so the upper limit is 5%. And

Iron oxide is composed of Fe ₂ O ₃ and FeO in the glass.
Exists in the state of. Fe ₂ O ₃ is a component that enhances the ultraviolet ray absorbing ability, and FeO is a component that enhances the heat ray absorbing ability.

Total iron oxide converted to Fe ₂ O ₃ (T-Fe ₂
If O ₃ ) is 1.0% or less, the effect of absorbing ultraviolet light and infrared light is small, and desired optical characteristics cannot be obtained. On the other hand, T-Fe
_{If the} content of ₂ O ₃ exceeds 1.9%, the temperature of the ceiling of the melting tank may become higher than the heat-resistant temperature during melting due to the heat ray absorbing effect of ferrous oxide, which is not preferable. Furthermore, if the T-Fe ₂ O ₃ is carried out continuously produced in large glass melting furnace than 1.9% is not preferred because it takes time to composition changes with different composition the glass base material. Note that a more preferable range is 1.2% or more and less than 1.8% (especially 1.%).
25 to 1.35%).

When the content of T-Fe ₂ O ₃ is 1.2% or more and less than 1.8%, the load on the kiln at the time of melting is small because T-Fe ₂ O ₃ is small, and the glass melting furnace is used. When producing continuously, there is an advantage that the time required for changing the composition of the glass base material is relatively short. Especially when T-Fe ₂ O ₃ is 1.25 to 1.35%, it is a great advantage as described above.

It should be noted that Fe ₂ O ₃ has the effect of significantly increasing absorption in the ultraviolet region, especially when the glass is subjected to air cooling. If the range of T-Fe ₂ O ₃ were as described above, the color tone of the glass after discoloration due to air cooling tempering treatment becomes the target color.

The ratio of FeO / T-Fe ₂ O ₃ (weight ratio of FeO to Fe ₂ O ₃ in terms of Fe ₂ O ₃ ) is 0.1 to
It is preferably 0.6. If this ratio is less than 0.1, the amount of FeO is small, so that sufficient heat ray absorbing ability cannot be obtained.

When the ratio of FeO / T-Fe ₂ O ₃ is larger than 0.6, the visible light transmittance is reduced and the color tone becomes bluish, and the amount of reducing Fe ²⁺ in the molten glass is reduced. , Nickel sulfide stones may be generated in the glass melt. Further, when the ratio is larger than 0.6, a line-like portion rich in silica may be generated, or silica scum may be generated. This FeO / T
By setting the ratio of -fe ₂ O ₃ to 0.1 to 0.6, greenish color of the glass is obtained close to the neutral color having high ultraviolet absorptivity and heat ray absorptivity. In this case, a numerical value converted into Fe ₂ O ₃ is used as the amount of FeO.

CoO is a component for obtaining a green-gray color tone close to neutral color by coexisting with Se and / or NiO and Fe ₂ O _3, and also a component for controlling visible light transmittance. However, if it is 0.02% or less, a desired color tone cannot be obtained and the visible light transmittance is too high. Also,
If it exceeds 0.05%, the color tone becomes too bluish, and the visible light transmittance also decreases. In particular, the amount of CoO is preferably more than 0.03% and 0.05% or less.

Se is a component for reducing stimulus purity in combination with the complementary color of CoO by pink coloration. When NiO is contained, Se does not necessarily have to be contained. If the Se content exceeds 0.003%, the visible light transmittance decreases. When using Se, 0.0001-
The range is preferably 0.003%, particularly 0.0001 to 0.002%. In this way, a desired color tone can be obtained without containing Se in a much smaller amount than conventionally required, or without using it at all. In addition, T-
By setting Fe ₂ O ₃ and FeO / T—Fe ₂ O ₃ within the above ranges, the amount of Se remaining in the glass can be increased.

TiO ₂ is a component for enhancing the ultraviolet absorbing ability particularly through the interaction with FeO, and for canceling the enhancement of the bluish color due to CoO. 0.7% TiO ₂ content
If it is less than 1, the bluish color due to CoO cannot be canceled,
It is impossible to obtain a green-gray intermediate tone close to a neutral color. If the amount of TiO ₂ is more than 2.0%, the desired color tone will be impaired, and if too much expensive TiO ₂ is used, the cost will be increased, which is not preferable. The amount of TiO ₂ is particularly preferably 0.8 to 1.2%.

NiO is a component for adjusting the visible light transmittance together with CoO to reduce the stimulus purity. In addition,
When Se is included, NiO may not necessarily be included. If the amount of NiO exceeds 0.2%, nickel sulfide may be formed in the product, and the visible light transmittance is reduced. The color tone is undesirably too brown. When NiO is contained, it is preferable that NiO is contained in the range of 0.001 to 0.2%, particularly 0.055 to 0.2%, for lower visible light transmittance.

If the NiO concentration in the glass is too high, Ni
O may agglomerate to form nickel sulfide stones,
Within the composition range of the present invention, a desired color tone can be obtained without generating nickel sulfide stone.

It is known that the coordination number of NiO changes depending on the cooling rate of the glass, and the state of color development differs. This is because the oxygen coordination number around Ni ²⁺ changes from 6 to 4 due to the cooling treatment, and the light absorption characteristics change. 6-coordinate Ni ²⁺ absorption exists around 430 nm,
While the glass is colored yellow, the absorption of four-coordinate Ni ²⁺ exists in the range of 500 to 640 nm, so that the use of four-coordinate Ni ²⁺ can reduce the stimulating purity and obtain a favorable color tone. . The window glass of a passenger car is usually subjected to a wind-cooling treatment for safety. NiO changes its coloration state even by this air-cooling treatment of glass. In the present invention, by utilizing the discoloration due to the air cooling enhancement process,
The color tone of the glass can be set to the target color tone without adding Se.

CeO ₂ is a component that enhances the ultraviolet absorbing ability, and exists in glass in the form of Ce ³⁺ or Ce ⁴⁺ . Particularly, Ce ³⁺ has little absorption in the visible region and is effective for ultraviolet absorption. In the present invention, Ce ³⁺ oxide is also included in CeO ₂ in terms of CeO ₂ . However, expensive C
Use of more than 2% of eO ₂ increases the cost, which is not preferable. Therefore, when CeO ₂ is included, the amount of CeO ₂ is set to 2% or less.

Mn ₂ O ₃ is a component for imparting a red to yellow-brown color tone to cancel the bluish tint.
If added in excess of the above range, the brown color becomes too strong and is not preferable in terms of color tone, so that it can be contained as needed in the range of 0.05% or less.

One or more of V ₂ O ₅ , MoO ₃ , CuO, Cr ₂ O ₃ or the like as a coloring agent, or SnO ₂ as a reducing agent in a total amount of 0 to the glass of the composition range of the present invention. In the range of from 1% to 1%, it may be added in a range that does not impair a green-gray-based color tone close to neutral transmittance and a neutral color aimed at by the present invention. Further, ZnO may be added in a range of 0 to 1% in order to more reliably prevent generation of nickel sulfide stone.

[0041] In the ultraviolet and infrared radiation absorbing and low transmission glass of the present invention, preferably have been subjected to air cooling tempering treatment as described above, in such air cooling tempering treatment, particularly NiO of the present invention, Fe ₂ O By adopting the _three compositions, good color tone or optical characteristics can be obtained.

This air-cooling strengthening treatment is performed by heating a glass plate manufactured from a glass base material at 600 to 750 ° C. by 2 to 5
It is performed by reheating for about a minute and then cooling by blowing air at 10 to 30 ° C. In this cooling, the temperature decreasing rate is preferably set to about 100 to 300 ° C./sec.

By the air-cooling strengthening treatment, the color tone becomes greenish gray close to neutral color due to the presence of NiO and Fe ₂ O ₃ contained in the glass, and the heat ray absorbing ability is maintained in terms of optical characteristics. The effect that the visible light transmittance and the ultraviolet light transmittance can be reduced while keeping the same is obtained.

Such an ultraviolet-ray-absorbing low-transmission glass of the present invention has a visible light transmittance (YA) of 18% or less, measured using a light source A, of the glass converted to a thickness of 4 mm.
Preferably 5 to 15%, total sunlight transmittance (TG) is 25
%, Preferably 5 to 15%, and the ultraviolet transmittance (TUV) specified by ISO is 7% or less.

Further, the chromaticity represented by a ^* and b ^* of the glass color tone using the L ^* a ^* b ^* color system is -10 ≦ a
It is preferable to be within the range of ^* ≦ 1, −3 ≦ b ^* ≦ 1.

In particular, when used as a privacy protecting glass for a rear window of a passenger car, since a color tone close to a neutral color is particularly preferred, the chromaticity represented by the a ^* and b ^* is | a ^* |
More preferably, -│b ^* │ ≦ 5 (that is, the difference between the absolute values of a ^* and b ^* is 5 or less).

The glass of the present invention has a dominant wavelength (λd) of 480 to 525 nm measured in a wavelength range of 380 to 770 nm using a glass C light source converted to a thickness of 4 mm.
It is preferable that the stimulus purity (Pe) has an optical characteristic of 17% or less.

[0048]

Embodiments of the present invention will be described below with reference to specific examples.

Examples 1 to 10 and Comparative Examples 1 to 3 Typical soda-lime-silica glass batch components include ferric oxide, titanium oxide, cobalt oxide, nickel oxide, cerium oxide and manganese oxide and metallic selenium. A part or all of them are added, and a carbon-based reducing agent (specifically, coke powder or the like) is added and mixed at a ratio of about 0.01 part by weight with respect to 100 parts by weight of the glass raw material. In 1500 ° C. and melted. After melting for 4 hours, pour out the glass substrate on a stainless steel plate,
Then, the mixture was gradually cooled to room temperature to obtain a glass plate having a thickness of about 6 mm. Then, the glass plate was polished to a thickness of 4 mm, reheated at 700 ° C. for 5 minutes, and blown at 20 ° C. with a wind pressure of 3.2 to 2.1 kgf / mm ² and a flow rate of 0.7 to 0. .
The air cooling enhancement treatment was performed by spraying at 6 Nm ³ / min and cooling at a temperature lowering rate of 200 ° C./sec. The visible light transmittance (Y
A), the total sunlight transmittance (TG), the ultraviolet transmittance (TUV) specified in ISO 9050, the dominant wavelength (λd) and the stimulus purity (Pe) were measured using a C light source, and further, L ^* , a ^* , and b ^* values were measured according to the CIE chromaticity diagram.

Table 1 shows the base glass composition of the obtained sample. Tables 2 to 4 show the T-Fe _{2 of} each sample.
O ₃ concentration, FeO (Fe ₂ O ₃ conversion) / T-Fe ₂ O ₃ ratio (% by weight), CoO concentration, NiO concentration, TiO ₂ concentration,
The CeO ₂ concentration, the Mn ₂ O ₃ concentration, the Se concentration, and the optical characteristic values after the air-cooling strengthening treatment are shown. The numbers indicating the concentrations in Tables 1 to 4 are expressed in terms of% by weight.
The e concentration and Mn ₂ O ₃ concentration are expressed in ppm. Also,
The numerical value below the decimal point is not displayed in the weight% of SiO _{2 in} Table 1, because the decimal part of SiO ₂ is rounded off.

[0051]

[Table 1]

[0052]

[Table 2]

[0053]

[Table 3]

[0054]

[Table 4]

As is clear from the above results, according to the present invention, the visible light transmittance (YA) measured using a light source A at a thickness of 4 mm is 18% or less, and the total sunlight transmittance (TG) is 4 mm or less. It can be seen that a glass having an optical characteristic of 25% or less and an ultraviolet transmittance (TUV) of 7% or less specified in ISO 9050 can be obtained.

On the other hand, Comparative Examples 1 to 3 are disclosed in JP-A-10-114.
540 shows the results of Examples 33 to 35 described in JP-A No. 540. However, since CoO is small, both the visible light transmittance (YA) and the total sunlight transmittance (TG) are the same as those of the glass of the present invention. Larger than compared.

[0057]

As described in detail above, according to the present invention, ultraviolet rays having a low gray light transmittance, a low neutral light transmittance, a low total sunlight transmittance and a low ultraviolet ray transmittance, and having a green-gray tone close to a neutral color. An infrared absorbing low transmission glass is provided.

The ultraviolet and infrared absorbing low transmission glass of the present invention, when applied to a rear window glass for automobiles or the like, or an architectural window glass, has an excellent effect of preventing deterioration and fading of interior interior materials. In addition to showing the privacy protection effect, the ultraviolet and infrared absorbing low transmission glass of the present invention has a sufficiently low visible light transmittance and a low total sunlight transmittance even in the form of a thin plate, and further has a low ultraviolet light. Because of the transmittance, the thickness of the window glass can be reduced, and thus the weight of the automobile can be reduced.

Continued on the front page (72) Inventor Nariwa Yoshii 3-5-1, Doshomachi, Chuo-ku, Osaka-shi, Osaka F-term in Nippon Sheet Glass Co., Ltd. 3D127 AA14 BB01 CC05 DD03 DD29 4G062 AA01 BB01 DA06 DA07 DB01 DB02 DB03 DC01 DD01 DE01 DF01 EA01 EB04 EC01 EC02 EC03 ED01 ED02 ED03 EE03 EE04 EF01 EG01 FA01 FB02 FB03 FC01 FD01 FE01 FF01 FG01 FH01 FJ01 FK01 FL01 GA01 GA10 GB01 GC01 GC02 GD01 H01 H01 H01 H03 H01H03 H01H03 JJ07 JJ10 KK01 KK03 KK05 KK07 KK10 MM01 NN05 NN07 NN12 NN13

Claims (10)

[Claims] 1. 65% to 80% of Si, expressed in% by weight.
O _2, 0 to 5% of Al ₂ O _3, 0~10% of MgO,. 5 to
15% CaO (however, the total amount of MgO and CaO is 5%)
15%), 10 to 18% of Na ₂ O, 0 to 5% of K ₂ O
(However, the total amount of Na ₂ O and K ₂ O is 10 to 20%),
And a base glass composition composed of 0 to 5% B ₂ O ₃ and a total iron oxide (T-Fe ₂ O ₃₎ converted to Fe ₂ O ₃ of more than 1.0% and 1.9% or less as a coloring component. ), More than 0.02% and up to 0.05% CoO, 0-0.003% Se,
0.7 to 2.0% of TiO _2, and 0 to 0.2% of Ni
A of glass made of O and converted to a thickness of 4 mm
Visible light transmittance (YA) measured using a light source is 18% or less, total sunlight transmittance (TG) is 25% or less, and ultraviolet ray transmittance (TUV) specified in ISO is 7% or less. An ultraviolet and infrared absorbing low transmission glass characterized by the following. 2. A according to claim 1, ultraviolet and infrared radiation absorbing and low transmission glass FeO in terms of Fe ₂ O ₃ is 10% to 60% of T-Fe ₂ O _3. 3. The dominant wavelength (λ) of a glass converted to a thickness of 4 mm measured using a C light source according to claim 1 or 2.
d) is 480 to 525 nm, and the ultraviolet ray-absorbing low-transmission glass has an excitation purity (Pe) of 17% or less. 4. The ultraviolet and infrared absorbing low transmission glass according to claim 1, comprising 2.0% or less of CeO ₂ . 5. The ultraviolet and infrared absorbing low-transmitting glass according to claim 1, comprising 0.05% or less of Mn ₂ O ₃ . 6. The method according to claim 1, wherein 0.001 to 0.003% of Se and / or 0.
Ultraviolet and infrared absorbing low transmission glass containing 001 to 0.2% NiO. 7. The ultraviolet and infrared ray absorbing low transmission glass according to claim 1, comprising 0.003 to 0.2% of NiO. 8. The method according to claim 7, wherein 0.055 to 0.2.
% UV-ray absorbing low-transmitting glass containing NiO. 9. The ultraviolet-ray-absorbing low-transmission glass according to claim 1, comprising more than 0.03% and 0.05% or less of CoO. 10. The ultraviolet-ray-absorbing low-transmission glass according to any one of claims 1 to 9, which has been subjected to an air-cooling strengthening treatment.