JPS61136936A - Glass composition - Google Patents

Abstract

PURPOSE:To obtain the titled glass composition preventing the deterioration of interior parts, etc., and having superior visual transmissivity and small solar radiation transmissivity by using said composition comprised of TiO2 and Fe2O3 in a specified compounding ratio as window glass. CONSTITUTION:The desired composition is obtd. from a composition which has characteristics containing 2-8wt% TiO2 and 0.1-0.8wt% Fe2O3 and having <=60% transmissivity of 400nm wavelength of light, >=65% visual transmissivity and <=65% solar radiation transmissivity expressed in terms of 5mm thickness. The above-described composition consists substantially the following composition (by wt%); 60-75 SiO2, 0-5 Al2O3, 5-15 CaO, 0-10 MgO, 6-20 CaO+MgO, 8-18 Na2O, 0-5 K2O, 10-20 Na2O+K2O, 2-8 TiO2, and 0.1-0.8 Fe2O3.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to glass compositions.

(Prior Art) A heat ray absorbing glass containing Fe2O3 as a heat ray absorbing component and further containing God, Nip, Ss, etc. as a color tone adjusting component is known. Such glass has, for example, the composition shown in the blue and brown columns of Table 1.

As shown in the same table, these heat-absorbing glasses are satisfactory in terms of solar radiation transmittance, but at wavelengths of 40
The transmittance for 0 nm light is 70% or more.

Therefore, when such glass is used as window glass,
Although it reduces the load on heating and cooling, it can hardly be expected to prevent interior components from deteriorating due to near ultraviolet rays.

On the other hand, there are glasses that are designed to absorb near-ultraviolet rays by adding other absorbers, but such glasses also have low transmittance to visible light and cannot be used in applications that require excellent transmittance. There wasn't.

(Problems to be Solved by the Invention) An object of the present invention is to provide a glass that, when used as window glass, prevents deterioration of interior components, etc., has excellent luminous transmittance, and has low solar radiation transmittance. That's true.

(Means to solve the problem) That is, the present invention is expressed as TiO22-B in weight %.

Contains Fe2030.1 to 0.8, converted to 5 Peng Thickness,
Transmittance of 400nm wavelength light 60% or less, luminous transmittance 6
Provided is a glass composition having characteristics of 5% or more and solar radiation transmittance of 65% or less.

The TiOz contained in the glass of the present invention has the effect of absorbing near ultraviolet rays of .about.40 On+w without significantly reducing the luminous transmittance. If the content of TiO2 is less than 2% by weight, this effect is insufficient and is not desirable.

On the other hand, when the T iOz content exceeds 8% by weight, the absorption in the visible light range increases, the luminous transmittance decreases, and the T
iOz is not preferable because it is expensive and increases the cost of raw materials.The content of TiO2 is more preferably in the range of 3 to B weight % within the above range.

Further, Fe2O3 is added for the purpose of reducing solar radiation transmittance, that is, absorbing heat rays. The content of Fe20x is Q,
If 1% by weight is incomplete, the heat ray absorption performance is insufficient, and if it exceeds 8% by weight, the absorption of visible light increases and the luminous transmittance decreases, so both are undesirable.
The content of 2O3 is more preferably in the range of 0.2 to 0.5% by weight within the above range.

The composition of the glass of the present invention is not particularly limited, but one having a primary composition is particularly preferable since the float method etc. with excellent productivity can be applied.

That is, Si0 is substantially 80-75゜Ah expressed as weight %.
03 0-5, CaO5-15.
MgOON 10. CaO+Mg0 8~20
．． Na2OB ~1B, , 20G ~5°N
201G to 2G to a2O+, TiO22 to 5.
It is a glass consisting of Fe2030.1 to 0.8.

Of these, SiOz is a glass network former, and when 5i02<80%, the weather resistance of the glass is poor;
If i02>75%, devitrification tends to occur, which is not preferable.

Al2O3 has the effect of improving weather resistance, but if it exceeds 5%, solubility deteriorates, which is not preferable.

(aO and MgO are added as flux and to improve weather resistance. CaO<5%.

CaO+MgO< [1% has poor weather resistance, Ca0)
15%MgO>10%, CaO+NgO>15%
It is easy to devitrify.

Na2O, K2O>20% is flux, Na2
0>18% and 20>20% for Na20+, the weather resistance is Akuhiramisaki 1, Na2O<8%, 20% for Na2O+
When the content is <10%, the solubility is poor, and when the content is 20>5%, the melting temperature of the glass increases, and in addition, K2O is more expensive than Na2O, so it is unsuitable.

Regarding TiO2 and Fe2O3, as mentioned above, in addition to the components of 0 or more, which will be omitted, 1 as a color tone adjustment component, such as Q, 0
2% or less Cod, Nip, O, 01% or less Se
can be added.

Among the above ranges, the more desirable range is 5iOz82-74%
, Al2O3 1-2%, Ca05-10%, Mg
O1~5%, CaO+Mg0 8~12%
, Na2O10-15%, K2O0-2%,
2011” 15% to Na2O+.

Ti023~8%, FezO3G, 2~0.5%.

Next, the optical properties will be explained, and unless otherwise specified in the following explanation, the values are meant in terms of the five-layer thickness.

If the light transmittance at a wavelength of 400 nm becomes too large, it is undesirable because it will cause severe deterioration of interior parts etc. when used for window glass.More preferably, the transmittance is 55% or less and Transient plexus is 10% or less.

On the other hand, if the luminous transmittance is less than 65%, the visible light transmittance decreases, which is undesirable, and the luminous transmittance is preferably 70% or more.

If the solar radiation transmittance exceeds 80%, the transmittance of heat rays becomes too high, and when used as window glass, the load of cooling and heating becomes large, which is not preferable.

The glasses according to the invention are produced, for example, by melting a batch in non-oxidized conditions. Such methods include a method of melting in an atmosphere with a low oxygen concentration (approximately 5% or less);
There is a method of adding a reducing agent such as C9Na2903 to the batch and melting it. Although the reason is not clear, if the same batch is melted without adding a reducing agent and in an oxidizing atmosphere, a glass with high near-ultraviolet transmittance can be obtained.

(Example) Silica sand, feldspar 9 limestone, dolomite, magnesium hydroxide, soda ash, and mirabilite were used as the main raw materials, ferric oxide powder was used as the Fe2O3 source, titanium dioxide powder was used as the TiO2 source, and cobalt oxide powder was used as the coloring agent. .

A batch was prepared using metal selenium powder and nickel oxide powder so that these raw materials had the target composition.Next, 500g of this batch was placed in a platinum crucible, and the oxygen temperature was approximately 0.596.
Using an electric furnace with an atmosphere adjusted to
The molten glass was heated for 3 hours to melt it, and then the molten glass was formed into a plate shape, and after cooling, the surface was polished to obtain glass of a predetermined thickness. The compositions of these glasses are shown in Table 1.

The optical properties measured for these glasses are also listed in the same table.

In addition, in order to investigate the fading prevention performance of these glasses, JI
A light resistance test was conducted according to SR3212.

That is, a 750 W mercury lamp was installed in a device maintained at 45 ± 5°C, and a 5 mm thick lamp was installed at a distance of 1 to 5 mm from the mercury lamp.
A glass is provided between the layers, a specimen is provided on the back side of the glass,
The fading of the specimen due to light transmitted through the glass was investigated.

The glass used was that of Material 11b6 in Table 1, and blue/brown as a comparative example.

The specimens used were plastic dash boards for automobiles in three types: black, gray, and brown.

After 300 hours of irradiation, the specimens were observed with the naked eye. As a result, all specimens using the glass of the present invention had less discoloration than those using other glasses.

(Effects) The glass according to the present invention has excellent luminous transmittance, excellent absorption of near ultraviolet rays, and heat ray absorption performance, so when used as window glass, the load on air conditioning and heating is reduced and deterioration of interior components, etc. It has extremely low luminous transmittance and is particularly suitable for vehicle window glass.

Claims (1)

[Claims] 1. TiO_2 in weight% 2-8, Fe_2O_3
Contains 0.1 to 0.8, and has a wavelength of 40 in terms of 5 mm thickness.
A glass composition having the characteristics of a transmittance of 0 nm light of 80% or less, a luminous transmittance of 85% or more, and a solar radiation transmittance of 85% or less. 2. Substantially expressed in weight%: SiO_2 60-75 Al_2O_3 0-5 CaO 5-15 MgO 0-10 CaO+MgO 6-20 Na_2O 8-18 K_2O 0-5 Na_2O+K_2O 10-20 TiO_2 2-8 Fe_2O_3 0.1 ~ 0.8. 3. The glass composition according to claim 1 or 2, which has a transmittance of 50% or less for light rays with a wavelength of 400 nm and a transmittance of 10% or less for light rays with a wavelength of 350 nm, when converted to a thickness of 3.5 mm.