JP3465642B2 - Light-colored high-transmission glass and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a soda lime glass having a light color tone and a high transmittance, which is suitable as a glass for a solar cell panel or a glass for construction, and a low-cost high-transparency glass. Relates to a method of manufacturing.

[0002]

2. Description of the Related Art In recent years, there has been a tendency to prefer lightly colored glass, especially so-called white plate glass, which has almost no coloring, for the exterior of buildings. In addition, photovoltaic power generation has been attracting attention as a measure against carbon dioxide reduction or fossil fuel depletion, and among them, a cover glass for a solar cell panel used to increase power generation efficiency is required. Further, as the substrate glass, glass having a high light transmittance in a wavelength range having high energy conversion sensitivity to sunlight is required.

As the glass for such purpose, a glass having a light color and a high transmittance, which is obtained by using a raw material having a high purity and having an iron content much less than that of a normal soda-lime glass, is used. Has been.

For example, the edge-colored transparent glass disclosed in Japanese Examined Patent Publication No. 7-29810 contains total iron oxide represented by weight% as Fe ₂ O ₃ expressed as wt% and less than 0.02%. , A soda-lime glass with a ratio of ferrous iron (FeO) to total iron oxide of at least 0.4, whereby a light transmission of at least 87% at a thickness of 5.66 mm (illumination C) It is a glass having a high transmittance with little coloring.

The glass also has a low SO ₃ content in order to obtain the above-mentioned properties, and a manufacturing process feature in which the melting operation includes separate liquefaction and fining steps,
It is characterized by using a batch material containing no limestone and dolomite to reduce the iron content in the glass.

Further, in the edge-colored transparent glass disclosed in Japanese Examined Patent Publication No. 8-715, a glass containing iron oxide of about the same amount has a edge color of 570 to 590 in harmony with a wood tone.
A minute amount of Se and CoO is added so that the glass has a main transmission wavelength of nm.

Alternatively, as a means for obtaining a glass having a light color tone and a high transmittance in a glass containing iron oxide of a normal degree, an oxidizer such as cerium oxide is added, and a main component that causes coloring and a decrease in transmittance. Fe
A method of lowering O is known.

For example, the transparent glass whose radiant light transmittance is adjusted disclosed in Japanese Patent Laid-Open No. 221683/1993 is an ordinary transparent glass containing 0.06 to 0.12 wt% of iron as an impurity in terms of Fe ₂ O _3. Soda lime-based plate glass is a glass containing 0.1 to 0.5% of CeO ₂ as an oxidant, and the ratio of Fe ²⁺ / Fe ^{3+ in} the glass is 38 in the case of ordinary soda-lime-based plate glass. % To 3 to 10%, and a high transmittance is obtained in a wavelength range around 600 nm or more.

On the other hand, there has been proposed a method of reducing the coloring of soda lime glass containing iron oxide as an impurity in a normal degree by changing the mother composition of the glass.

For example, according to the transparent glass composition for producing a window glass disclosed in JP-A-8-40742, the total amount of iron oxide converted to ferric oxide is 0.0.
2 to 0.2% by weight of soda-lime-silica based glass, the mother composition of which is 69% to 75% of Si expressed by% by weight.
O _2, 0 to 3% of Al ₂ O _3, 0~5% of B ₂ O _3, 2~1
0% CaO, less than 2% MgO, 9-17% Na ₂
O, 0-8% K ₂ O, optionally fluorine, zinc oxide, zirconium oxide, and less than 4% by weight barium oxide, with a total alkaline earth metal oxide content of 10% by weight or less. , A soda-lime-silica-based glass having a normal matrix composition by shifting the absorption band of FeO to a longer wavelength or by making the absorption band slope linear at the edge of the visible range near the infrared of the absorption band of FeO. It is said that it becomes possible to manufacture a window glass with less coloring and good infrared absorption.

[0011]

[Problems to be Solved by the Invention] Japanese Patent Publication No. 7-298
In the edge-colored transparent glass disclosed in Japanese Patent Publication No. 10 or Japanese Examined Patent Publication No. 8-715, the total iron oxide expressed as Fe ₂ O ₃ contained as a coloring agent is expressed in weight% and is from 0.02%. In order to keep it low, it is impossible to use limestone or dolomite containing a relatively large amount of iron oxide as an impurity. Therefore, it is necessary to use a special raw material such as calcium carbonate mineral or aluminum hydrate having a small amount of iron oxide, and the glass obtained as a result is expensive.

Further, in the edge-colored transparent glass disclosed in Japanese Patent Publication No. 29810/1995, in order to obtain a desired pure and bright azure color, iron in the ferrous state (FeO ) Must be at least 0.4.

To this end, it is desirable to employ a special manufacturing method involving separate liquefaction and fining steps as the melting operation and to keep the SO ₃ content low, resulting in a more expensive glass. .

In the transparent glass having the adjusted radiant light transmittance disclosed in Japanese Patent Laid-Open No. 5-221683, iron oxide, which is contained in the same degree as that of ordinary soda lime-based plate glass,
Oxidation is carried out by adding a necessary amount of an oxidizing agent, for example, cerium oxide, and the Fe ²⁺ / Fe ³⁺ ratio of the iron oxide contained is made lower than that in the case of ordinary soda lime based glass.

According to this method, it is possible to certainly reduce the absorption of FeO by reducing the absorption of FeO, but conversely increase the absorption of Fe ₂ O ₃ near 400 nm. , The color of the glass becomes yellowish, which is not desirable depending on the application.

Further, since iron oxide is contained to the same extent as ordinary soda-lime based glass, a relatively large amount of oxidizing agent is required in order to reduce the Fe ²⁺ / Fe ³⁺ ratio, so that the glass is The cost will be high.

Further, increasing the absorption in the vicinity of 400 nm as described above lowers the conversion efficiency in the case of a solar cell made of amorphous silicon having the highest sensitivity of energy conversion in the vicinity of 500 to 600 nm. Therefore, it is not preferable.

In the transparent glass composition for producing a window glass disclosed in JP-A-8-40742, a soda lime-based glass containing iron oxide of a normal degree is prepared by changing the mother composition of the glass. Higher transmittance.

However, the effect of the method disclosed in the same patent is that the absorption of FeO is shifted to the long wavelength side, and the glass for building materials for which a light color tone is desired and the glass for solar cells for which high transmittance is required. Is not enough for.

The composition disclosed in the patent is M
Since the amounts of gO and MgO + CaO are small and the inconvenience in melting due to this is compensated for by making the amount of Na ₂ O larger than usual, weather resistance is poor, burns easily occur, and the cost is high. The composition is not suitable for mass production.

The effects disclosed in the patent are F, B.
Although it can be strengthened by adding components such as aO, the addition of these components is not preferable because it increases cost, shortens the life of the kiln due to volatilization of F, and discharges harmful substances into the atmosphere.

The present invention has been made in view of the above-mentioned problems of the prior art, and has a light color tone and a high transmittance suitable for light-colored and high-transmission glass, particularly for solar cell panel glass or architectural glass. It is an object of the present invention to provide glass and a method for manufacturing those glasses at low cost.

[0023]

That is, according to the present invention, in a glass containing silica as a main component, 0.02 to 0.06% (however, 0.
Total iron oxide (T-, not including 06%) converted to Fe ₂ O ₃
Fe ₂ O ₃ ), FeO less than 0.008%, 0.02
Containing 5 to 0.5% of cerium oxide, and ratio _{Fe 2 O 3 T-Fe 2} O 3 of FeO in terms of (hereinafter, F
(eO ratio) is 22% or less, and contains substantially no coloring component other than iron oxide, cerium oxide, and manganese oxide, and has a solar radiation transmittance of 8 at a thickness of 3.2 mm.
It is a light-colored highly transmissive glass having an ultraviolet transmittance of 9.5% or more, an ultraviolet transmittance of 60% or less defined by ISO9050, and a visible light transmittance of 90% or more measured using a C light source.

[0024] Here, the coloring component of the light-colored high-transmittance glass of the present invention, the total iron oxide in terms of 0.02 to 0.05% by weight of _{Fe 2 O 3 (T-Fe} 2 O 3), 0.008% Fe less
It is desirable to contain O, the main wavelength is larger than 495 nm and smaller than 575 nm, and the stimulation purity is 0.4%.
The following is more desirable.

A more desirable range of the present invention is that the content of FeO is more than 0.004%, and
The composition has a ratio of 15% or more and has a dominant wavelength of 565n when measured using a C light source at a thickness of 3.2 mm.
2. It is desirable that the stimulus purity is less than 0.3 m and the stimulation purity is 0.3% or less. In this range, the composition contains FeO less than 0.008% and the FeO ratio is 20 to 22%. Most preferably, at a thickness of 2 mm, the dominant wavelength measured using a C light source is less than 560 nm.

The above desirable range is a reasonably low T
-Fe ₂ O ₃ and the FeO ratio which is not extremely low are suitable as architectural glass having a desirable light color tone. Further, it is particularly suitable as a glass for a solar cell made of amorphous silicon having the highest sensitivity of energy conversion in the vicinity of 500 to 600 nm.

Further, in this desirable range, not only the transmittance in a wavelength region having high sensitivity when used for a solar cell is high, but also a proper amount of FeO is contained,
It also has another preferable effect of appropriately absorbing the solar radiation that causes the temperature rise of the amorphous silicon, which adversely affects the conversion efficiency.

On the other hand, as another more desirable range of the present invention, FeO less than 0.008%, 0.025 to
It contains 0.5% cerium oxide and has an FeO ratio of 22.
%, The solar radiation transmittance is 89.5% or more, the ultraviolet transmittance defined by ISO 9050 is 60% or less, and the main wavelength measured using a C light source is 540 nm. It is desirable to be larger, and in this range Fe less than 0.006%
O, composed of a composition containing 0.025 to 0.25% cerium oxide, and having a thickness of 3.2 mm, a solar radiation transmittance of 90.5% or more and an ISO 9050 ultraviolet ray transmittance of 55% or less. It is most desirable that the dominant wavelength measured using a C light source is larger than 555 nm.

Another desirable range is the so-called white plate glass with almost no coloring which is particularly desirable for building materials due to the reasonably low T-Fe ₂ O ₃ and FeO ratio.
It is also suitable as a glass for solar cells made of crystalline silicon having the highest sensitivity of energy conversion in the vicinity of 1000 nm. In this desirable range, cerium oxide as an oxidant also has an effect of absorbing ultraviolet light,
It also has another preferable effect of appropriately absorbing ultraviolet rays, which has an undesirable effect in various applications, such as deterioration of silicon when used for a solar cell.

The basic glass composition of the above-mentioned desirable colorant component and the light-colored highly transparent glass having optical properties is, in terms of weight%, 65-80% SiO ₂ , 0-5% A.
l ₂ O ₃ , 2% more MgO, 5-15% CaO, 1
0-18% Na ₂ O, 0-5% K ₂ O, 7-17% MgO + CaO (excluding 7%), 10-20
% Of _{Na 2 O + K 2 O,} 0.05~0.3% of SO _3, and desirably made of 0-5% B ₂ O _3, 10%
It is further desirable to contain more MgO + CaO, more than 0.1% SO ₃ . Further, it is desirable that it contains substantially no fluorine, barium oxide, or strontium oxide.

The above-described light-colored highly transparent glass according to the present invention is
Substrate glass for solar cell panels, cover glass for solar cell panels, materials for solar water heaters, solar heat transparent window glass materials, highly transparent non-colored mirrors, highly transparent non-colored window glass, exhibition protection case glass, front panel flat displays, etc. When used as a substrate glass or the like, its effect can be maximized.

In the production of the light-colored highly transparent glass according to the present invention, dolomite, limestone and alumina-containing silica sand are used as the raw material in the same manner as soda-lime glass in order to reduce the cost of the glass as much as possible. Desirably, this can be achieved by setting the iron oxide content within the above-mentioned range.

As the melting method, as in the above, in order to reduce the cost increase of the glass as much as possible, a liquefying step and a refining step, which are used in a normal soda-lime glass melting kiln, are carried out in one kiln tank. It is desirable to melt in an upper heating tank type melting furnace called the above.

The reasons for limiting the composition of the light-colored highly transparent glass of the present invention will be described below. However, the following compositions are expressed in% by weight.

Iron oxide is used as Fe ₂ O ₃ and FeO in glass.
Exists in the state of. Fe ₂ O ₃ is a component that enhances the ability to absorb ultraviolet rays, and FeO is a component that enhances the ability to absorb heat rays.

In order to obtain a desired light color and high transmittance, the total iron oxide (T-Fe ₂ O ₃ ) content is 0.02 to 0.06%.
(However, 0.06% is not included), FeO is 0.008
% Less, Fe ₂ O _{3 2-converted} FeO is of T-Fe ₂ O ₃ in
It must be in the range of 2% or less. Total iron oxide (T
When the content of —Fe ₂ O ₃ ) is less than 0.02%, it is necessary to use a high-purity raw material having a low iron content as a raw material, which significantly increases the cost. When the total iron oxide, FeO, and FeO ratios are not less than the upper limits of the respective ranges, the visible light transmittance becomes too low, and FeO enhances the blue color tone.

In order to obtain a lighter color tone and a high visible light transmittance, the total iron oxide (T-Fe ₂ O ₃ ) content is 0.02-0.02.
5% and FeO are preferably less than 0.008%.

Further, in the case of glass for solar cells using amorphous silicon, which is desired to have a high transmittance in the vicinity of 500 to 600 nm and an appropriate absorption of solar radiation, the total iron oxide content is within the above range. , FeO is 0.004%
It is desirable that the FeO ratio is 15% or more, but if the FeO / FeO ratio is too large, the color tone of the glass becomes strong. Therefore, in the range where FeO is less than 0.008%,
It is more desirable that the FeO ratio is 20 to 22%.

On the other hand, in the case of a glass for a solar cell using crystalline silicon, which is desired to have a high transmittance in the vicinity of 1000 nm, or in the case of a so-called white plate glass with almost no coloration, FeO within the above-mentioned total iron oxide amount range. Is 0.008%, preferably less than 0.006%, F
It is desirable that the eO ratio is 22% or less.

Cerium oxide is an effective component for adjusting the ratio of FeO and FeO. Particularly, small FeO and FeO required for high transmittance around 1000 nm or for obtaining glass with almost no coloring.
In order to achieve the ratio, cerium oxide should be 0.025 ~.
0.5% is preferably added, and 0.025 to
It is desirable to add 0.25%.

SiO ₂ is the main component forming the skeleton of glass. If the SiO ₂ content is less than 65%, the durability of the glass will decrease, and if it exceeds 80%, it will be difficult to melt the glass.

Al ₂ O ₃ is a component that improves the durability of the glass, but if it exceeds 5%, melting of the glass becomes difficult. It is preferably in the range of 0.1 to 2.5%.

MgO and CaO are used to improve the durability of glass and to adjust the devitrification temperature and viscosity during molding. When MgO is 2% or less, the devitrification temperature rises. If CaO is less than 5%, the solubility deteriorates. Also, 1
When it exceeds 5%, the devitrification temperature rises, and it is desirable that it is less than 13%. If the total of MgO and CaO is 7% or less, the durability of the glass decreases. On the other hand, if it exceeds 17%, the devitrification temperature rises, and it is preferably 15% or less. MgO and CaO
If the total of the above is small, for example, 10% or less, it is necessary to add a large amount of Na2O in order to compensate for the deterioration of the solubility and the increase of the viscosity of the glass melt, resulting in an increase in cost and a decrease in the chemical durability of the glass. So the total of MgO and CaO is 1
More than 0% is desirable.

Na ₂ O and K ₂ O are used as glass melting accelerators. When the content of Na ₂ O is less than 10% or the total content of Na ₂ O and K ₂ O is less than 10%, the dissolution promoting effect is poor, and Na ₂ O exceeds 18%, or Na ₂ O and K ₂ O
If the total amount of O exceeds 20%, the durability of glass decreases. Since K ₂ O is expensive as a raw material compared to Na ₂ O, 5
% Is not preferable.

SO ₃ is a component that promotes the fining of glass. If it is less than 0.05%, the fining effect becomes insufficient by the usual melting method, and the desirable range is 0.1% or more. On the other hand, if it exceeds 0.3%, SO ₂ generated by its decomposition remains in the glass as bubbles, or bubbles tend to be generated by reboil.

B ₂ O ₃ is a component used for improving the durability of glass or as a melting aid. When B ₂ O ₃ exceeds 5%, B inconvenience during molding due to volatilization of the ₂ O ₃ is the upper limit of 5% since they produce.

Although TiO ₂ is not an essential component, it can be added in an appropriate amount for the purpose of increasing the ultraviolet absorbing ability, etc. within a range that does not impair the optical characteristics aimed at by the present invention.
If the amount is too large, the glass tends to become yellowish,
Also, since the transmittance in the vicinity of 500 to 600 nm decreases,
It is desirable that the content be kept low within the range of less than 0.2%.

Further, even if fluorine, barium oxide or strontium oxide is contained, the effect of the present invention is not impaired, but these components have an unfavorable influence on cost increase, kiln life, and release of harmful substances to the atmosphere. Is an ingredient that exerts
It is desirable not to contain it substantially.

As a component to be added as an oxidant to the glass having the above composition range, cerium oxide in the range limited to the above is desirable because of its effect and another preferable effect of ultraviolet absorption, but other oxidants such as manganese oxide. 1%
It may be added in combination with cerium oxide alone or in the following ranges.

Further, SnO ₂ may be added as a reducing agent in the range of 1% or less. Since the addition of the colorant strengthens the color tone and lowers the visible light transmittance, it is preferable not to add the colorant substantially.

[0051]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to specific examples.

(Examples 1 to 6) Raw materials having the composition shown in Table 1 in terms of weight% converted to oxides were prepared by using low iron alumina-containing silica sand, limestone, dolomite, soda ash, glauber's salt, and oxidation. It was prepared by using cerium, manganese dioxide and a carbon-based reducing agent, and this raw material was heated and melted at 1450 ° C. in an electric furnace. After melting for 4 hours,
The glass substrate was poured onto a stainless plate and gradually cooled to room temperature to obtain a glass having a thickness of about 10 mm. The concentrations in the table are
All are in weight percent.

Next, this glass was polished to a thickness of 3.2 mm, and the visible light transmittance, the dominant wavelength, the stimulus purity, the solar radiation transmittance, I
The ultraviolet transmittance defined by SO9050 was measured. Table 1 shows optical characteristic values of the obtained samples.

[0054]

[Table 1] ------------------------------------------ Example-- 1 2 3 4 5 6-- −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− SiO ₂ 71.0 71.7 71.6 72.0 71.1 71.3 Al ₂ O ₃ 1.4 1.7 1.7 1.8 1.8 1.5 MgO 4.3 4.0 4.2 4.2 4.4 4.2 CaO 8.6 8.5 8.5 8.5 9.0 8.5 Na ₂ O 13.5 13.0 13.0 12.5 12.6 13.1 K ₂ O 0.7 0.7 0.7 0.7 0.7 1.0 SO ₃ 0.22 0.25 0.20 0.21 0.23 0.23 Total iron oxide 0.031 0.031 0.036 0.036 0.036 0.036 TiO2 0.03 0.03 0.04 0.04 0.04 0.04 Cerium oxide 0.2 0.1 0.05 0.05 0.075 0.1 Manganese oxide 0 0 0 0 0 0 Total 100.0 100.0 100.0 100.0 100.0 100.0 FeO 0.003 0.001 0.007 0.005 0.003 0.003 FeO ratio 11 4 22 15 9 9 −−−−−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−− Visible light transmittance 91.6 91.8 91.4 91.7 91.6 91.6 Solar radiation transmittance 90.9 91.6 89.9 91.0 91.0 91.0 UV transmittance Excessive rate 42.9 50.3 55.4 54.9 51.5 48.4 Main wavelength 563 568 547 562 566 566 Stimulus purity 0.20 0.23 0.10 0.23 0.26 0.26 −−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−−−−

Examples 1 to 6 have compositions within the scope of claims 1 and 2, and as is clear from Table 1, the visible light transmittance measured with a C light source at a thickness of 3.2 mm is 9
It is a glass having optical characteristics of 0% or more, solar radiation transmittance of 89.5% or more, ultraviolet ray transmittance of 60% or less, and main color wavelength of more than 540 nm. Further, all of Examples 1 to 6 have the preferable color tone shown in claim 3, and are desirable basic glass compositions shown in claim 8.

In Examples 3 and 4, the composition is within the range of Claim 4, which is a more preferable range. The dominant wavelength at a thickness of 3.2 mm is smaller than 565 nm, and the stimulation purity is 0.3.
% Of the glass having a preferable color tone.

Example 3 has a composition within the range of claim 5, which is a more preferable range, and is a glass having a more preferable color tone in which the dominant wavelength at a thickness of 3.2 mm is smaller than 560 nm.

Examples 1 to 6 all have compositions within the scope of claim 6. These are glasses with a color tone having a solar radiation transmittance of 89.5% or more, an ultraviolet transmittance of 60% or less, and a dominant wavelength of more than 540 nm in a thickness of 3.2 mm.

Examples 1, 2 and 4 to 6 have a composition within the range of claim 7, which is a more preferable range, and have a composition of 3.2 mm.
The glass having a more preferable color tone has a solar radiation transmittance of 90.5% or more, an ultraviolet radiation transmittance of 55% or less, and a dominant wavelength of more than 555 nm.

Examples 1 to 6 all have compositions within the scope of claim 9, and are substantially fluorine, barium oxide, and
It is also a glass within the scope of claim 10 which does not contain strontium oxide.

Further, all of Examples 1 to 6 are the substrate glass for a solar cell panel, the cover glass for a solar cell panel, the material for a solar water heater, the solar-transparent window glass material, and the highly transparent uncolored mirror described in claim 12. It is a glass suitable for flat display substrate glass such as highly transparent uncolored window glass, display protection case glass, and full-scale panel.

(Comparative Examples 1 to 4) Table 2 shows compositions and optical characteristics of Comparative Examples with respect to the present invention. The composition is% by weight.

[0063]

[Table 2] ------------------ Comparative Example 1 2 3 4 --------------- −−−−−−−−−−−−−− SiO ₂ 72.4 73.07 73.50 70.80 Al ₂ O ₃ 1.42 1.80 0.90 1.90 MgO 4.1 0.08 − 3.70 CaO 8.0 10.11 9.00 8.90 SrO − 0.21 − − Na ₂ O 13.1 14.63 15.80 13.50 K ₂ O 0.72 0.01 0.29 0.60 SO ₃ 0.23 0.015 0.30 0.25 Total iron oxide 0.10 0.010 0.1 0.09 TiO2 0.03 − 0.04 − Cerium oxide − − − 0.20 ZrO ₂ − 0.028 − − Total 100.08 99.935 99.93 99.94 FeO 0.027 0.028 FeO ratio 30 60 31 Plate thickness (mm) 3.20 5.66 3.85 −−−−−−−−−−−−−−−−−−−−−−−−−−− Visible light transmittance 90.1 90.8 89.9 * − Solar radiation transmittance 85.0 88.5 − − UV transmittance 60.8 − − − Main wavelength 502 490.5 541 − Stimulus purity 0.34 0.27 0.30 − −−−−−−−−−−−−−−−−−−−−−−−−−−− *: Light source is A light source

Comparative Example 1 is a typical soda-lime glass. Comparative Example 2 is Japanese Patent Application Laid-Open No. 7-298 cited in the text.
Example 10 in Japanese Patent Laid-Open No. 10-2004, Comparative Example 3 is an example in Japanese Patent Laid-Open No. 8-40742 cited in the text, and Comparative Example 4 is Example in Japanese Patent Laid-Open No. 5-221683 cited in the text. This is an example.

Comparative Example 1 has a lower solar radiation transmittance and a lower visible light transmittance than the glass of the present invention. Comparative Example 2 has properties similar to those of the glass of the present invention, but iron oxide is as low as 0.010%, and a special high-purity raw material is required to reduce the amount of iron oxide in this way. Costs more. In Comparative Example 3, the color tone estimated from the visible light transmittance and the stimulus purity is not so different from that of normal soda-lime glass. In Comparative Example 4, the optical characteristics of the glass are not specifically described, but when the transmittance of 400 nm is read from the described spectral transmittance curve, the glass of the ordinary soda lime-based glass described together for comparison is While it was about 87%, that of the glass of Comparative Example 4 was about 83%, and as a result of lowering the FeO content by adding cerium oxide,
It shows that Fe ₂ O ₃ is increased and the glass has low transmittance in the visible short wavelength region.

[0066]

According to the first aspect of the present invention, by limiting the total iron oxide, FeO, cerium oxide and FeO ratios of the coloring components, a light-colored highly transparent glass having a high solar radiation transmittance and a high visible light transmittance can be obtained. .

In the second aspect, by further limiting total iron oxide and FeO, a light-colored highly transparent glass having a higher solar radiation transmittance and a higher visible light transmittance can be obtained.

In the third aspect, by limiting the dominant wavelength and the stimulus purity, a light-colored highly transparent glass which has a preferable color tone for architectural glass and which is made of amorphous silicon and is suitable as a glass for solar cells can be obtained.

According to the fourth aspect, by further limiting the FeO and FeO ratios, it is possible to obtain a glass in which the dominant wavelength and the excitation purity are more preferable.

By further limiting the FeO to FeO ratio in claim 5, a solar cell made of amorphous silicon having a light green color tone which is particularly suitable for architectural glass and which has particularly high power generation efficiency is obtained. A suitable light-colored highly transparent glass is obtained.

According to the sixth aspect, so-called white plate glass with almost no coloring, which is particularly desirable for building materials, and glass particularly suitable for solar cells made of crystalline silicon can be obtained.

In the seventh aspect, the upper limit of FeO is further limited and the upper limit of expensive cerium oxide is limited, whereby a glass having a higher solar radiation transmittance and a lower ultraviolet transmittance can be obtained at a low cost.

In the eighth aspect, by limiting the basic glass composition, a light-colored highly transparent glass having the above-mentioned desirable optical characteristics can be obtained.

In claim 9, MgO + CaO and SO3
By limiting the above, high quality glass can be obtained.

In claim 10, fluorine, barium oxide,
By limiting the content of strontium oxide, it is possible to prevent the generation of harmful substances and the deterioration of the melting furnace, and obtain low-cost glass.

Claim 11 discloses a use in which the light-colored highly transparent glass according to the present invention can maximize its effects.

According to the twelfth and thirteenth aspects, the cost of the glass can be reduced by limiting the raw material to dolomite, limestone, and silica-containing silica, which are the same as those of ordinary soda-lime glass.

In claim 14, the cost of glass is reduced by melting in an upper heating tank type melting furnace used in a normal soda-lime type glass melting furnace where the liquefying step and the refining step are carried out in one kiln tank. It is possible to reduce.

As described above, according to the light-colored highly transparent glass of the present invention, it is possible to obtain a glass having little or very little coloring and a high transmittance at a low cost. Also,
INDUSTRIAL APPLICABILITY The light-colored highly transparent glass of the present invention is useful as architectural glass, and also useful as glass for solar cells, which requires high sunlight transmittance.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-10-45424 (JP, A) JP-A-11-335132 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C03C 1/00-14/00 WPI

Claims (14)

(57) [Claims] 1. In a glass containing silica as a main component, as a coloring component, 0.02 to 0.06% (however, 0.06% is not included) is displayed in% by weight.
Total iron oxide in terms of Fe ₂ O ₃ in _{(T-Fe 2 O 3)} , less than 0.008% FeO, containing from 0.025 to 0.5% cerium oxide, and terms of Fe ₂ O ₃ ratio T-Fe ₂ O ₃ of FeO was (hereinafter, FeO ratio) is a composition or less 22%, iron oxide, cerium oxide, it contains substantially no coloring component other than the manganese oxide, 3.2 mm At a thickness of 89.5% or more, the transmittance of UV rays specified by ISO9050 is 60% or less, and the transmittance of visible light measured using a C light source is 90% or more. Highly transparent glass. Wherein in% by weight, 0.02 to 0.05% by weight of Fe ₂ O ₃ the total iron oxide (T-Fe ₂ O ₃₎ in terms of, containing less than 0.008% FeO The light-colored highly transparent glass according to claim 1, wherein 3. The dominant wavelength is greater than 495 nm and 57.
The light-colored highly transparent glass according to claim 1 or 2, which has a stimulation purity of less than 5 nm and 0.4% or less. 4. Measured with a C light source at a thickness of 3.2 mm, comprising a composition containing more than 0.004% FeO, expressed in% by weight, and having an FeO ratio of 15% or more. ,
The light-colored highly transparent glass according to any one of claims 1 to 3, wherein the dominant wavelength is smaller than 565 nm and the stimulation purity is 0.3% or less. 5. Measured with a C light source at a thickness of 3.2 mm, comprising a composition containing less than 0.008% FeO and having an FeO ratio of 20 to 22%, expressed in% by weight. 5. The dominant wavelength is smaller than 560 nm.
Light-colored highly transparent glass according to. 6. The dominant wavelength measured using a C light source is 540.
The light-colored highly transparent glass according to any one of claims 1 to 3, wherein the light-colored highly transparent glass has a size larger than nm. 7. A composition comprising FeO of less than 0.006% and 0.025 to 0.25% of cerium oxide, expressed in% by weight, and having a solar radiation transmittance of 90 at a thickness of 3.2 mm. The light-colored highly transparent glass according to claim 6, which has an ultraviolet transmittance of 55% or less specified by ISO 9050 and a dominant wavelength measured using a C light source of more than 555 nm. 8. The basic glass composition, expressed in% by weight, is: 65-80% SiO ₂ , 0-5% Al ₂ O ₃ , more than 2% MgO, 5-15% CaO, 10 18% Na ₂ O, 0 to 5% K ₂ O, 7 to 17% MgO + CaO (excluding 7%), 10 to 20% Na ₂ O + K ₂ O, 0.05 to 0.3 % of SO _3, and light-colored high-transmittance glass according to claim 1, characterized in that it consists of 0-5% B ₂ O _3. 9. Light-colored highly transparent glass according to claim 8, characterized in that it contains more than 10% MgO + CaO and more than 0.1% SO ₃ , expressed in% by weight. 10. The composition according to claim 1, which is substantially free of fluorine, barium oxide and strontium oxide.
The light-colored highly transparent glass according to any one of 1 to 9. 11. A substrate glass for a solar cell panel, a cover glass for a solar cell panel, a material for a solar water heater, a solar-transparent window glass material, a highly transparent uncolored mirror, a highly transparent uncolored window glass, an exhibit protection case glass, The light-colored highly transparent glass according to any one of claims 1 to 10, which is used as a flat display substrate glass such as an entire panel. 12. The method for manufacturing a light-colored highly transparent glass according to claim 1, wherein dolomite or limestone is used as a raw material. 13. The method for producing a light-colored highly transparent glass according to claim 12, wherein alumina-containing silica sand is used as a raw material. 14. The method for producing a light-colored highly transparent glass according to claim 12, wherein the batch raw material is melted in an upper heating tank type melting furnace.