WO2016158841A1 - Glass article - Google Patents

Abstract

The present invention provides a highly transmissive glass article in which solarization is reduced and for which absorbance on the short wavelength side and the extinction coefficient of Fe³⁺ caused by the addition of CeO₂ are suppressed compared with conventional CeO₂-containing glass. The present invention relates to the glass article which comprises glass that satisfies a specific composition range and redox ratio of iron.

Description

Glass article

The present invention relates to a glass article in which solarization is suppressed while maintaining absorption in the ultraviolet region to some extent, and has a high transmittance from the visible region to the infrared region.

Conventionally, solar power generation has been promising as an effective use of natural energy in response to environmental problems. At the heart are solar cells (PV), concentrating solar power (CSP) systems, and concentrating solar power (CPV) systems.

A conventional solar cell module includes a surface layer made of template glass or float glass, a resin layer including an ethylene-vinyl acetate copolymer (EVA) film or polyethylene sheet that protects solar cells, a solar cell element, and a back surface. The back surface material which consists of a sheet | seat, a template glass, or float glass etc. is included. Factors that degrade the power generation amount of the solar cell module over time include degradation of insulation resistance such as internal elements due to the influence of moisture entering the solar cell module, and decrease in transmittance due to ultraviolet degradation of the resin layer inside the solar cell module. Can be mentioned.

As a technique to suppress the intrusion of moisture into the solar cell module, the back sheet used for the solar cell module is changed to glass, and the ingress of moisture into the solar cell module is suppressed to suppress deterioration of the internal solar cell elements, etc. It is possible to do.

Since the solar cell module uses glass for the surface material, if glass is used for the back material, glass is used for the surface material and the back material. Thus, in the solar cell module using glass on both sides, it is important to ensure the adhesion between the glasses and the durability after bonding.

Conventionally, solar cell modules in which both the front material and the back material are template glass, a solar cell module in which the surface material is template glass and the back material is float glass, and a solar cell module in which both the front material and back material are float glass have been developed. ing.

When the surface material and the back material are both template glass, or when the surface material is template glass and the back material is float glass, it is considered difficult to ensure adhesion and durability after bonding. If both sides are float glass, it is considered advantageous in terms of adhesion and durability after bonding, but the current float glass does not provide the same high transmittance as that of template glass, avoiding a decrease in power generation. Absent. Furthermore, since the template glass and the conventional float glass have a high transmittance in the ultraviolet region, there is a problem that the resin layer deteriorates.

On the other hand, conventionally, a mirror module for concentrating solar power generation and concentrating solar power generation is composed of a protective layer, a metal reflection layer, and a resin base material in this order from the light incident side. When conventional float glass is used as a protective layer, there is a problem that the resin base material is deteriorated because the transmittance in the ultraviolet light region is high. Moreover, since the conventional float glass cannot obtain high transmittance, there is a problem that the reflectance is low and the efficiency is poor.

Regardless of the above uses, glass articles having a high transmittance in the visible light region are required to suppress solarization in addition to the above problems. Patent Documents 1 to 4 each disclose a glass having a high transmittance in the visible light region.

The main factor of light absorption of the glass plate is iron ions contained as impurities. Iron is unavoidably contained as a raw material for industrially produced glass, and it is inevitable that iron is mixed into the glass. Iron ions take the form of divalent (Fe ²⁺ ) and trivalent (Fe ³⁺ ) in the glass, but particularly problematic is Fe ²⁺ having a broad absorption at a wavelength of 490 to 780 nm.

Fe ³⁺ has an absorption band at a wavelength of 380 to 490 nm, but its influence is small because the extinction coefficient per unit concentration is one digit smaller than that of Fe ²⁺ . For this reason, in order to reduce the light absorption in the visible range, it is necessary to devise a technique for reducing the ratio of the Fe ²⁺ amount to the total iron ion amount in the glass as much as possible, that is, the iron redox ratio.

In a glass plate that is industrially produced by the float process, reducing the total iron content contained as impurities until the transmittance of the glass plate is about the same as or higher than that of the template glass is the production surface and raw material surface, etc. There are many constraints in.

In order to increase the transmittance of the float glass plate to the same level or higher as that of the template glass within the range of the allowable iron content, it is indispensable to lower the iron redox ratio than before. In order to reduce the redox ratio of iron, it is effective to add an oxidizing agent. However, Sb ₂ O ₃ which is generally used for producing a template glass is a problem of coloring in a float bath. Because it has a high environmental impact, it cannot be used practically.

CeO ₂ does not cause these problems. However, in an actual glass melting kiln, the oxidizing power is weak, so it is necessary to increase the amount of addition. However, if the amount of CeO ₂ added is increased, the transmittance in the visible light region from the ultraviolet region becomes lower, and solarization occurs, so that there are practical problems. Therefore, CeO ₂ can be used more efficiently as an oxidizing agent. Realization of measures for use is desired.

Japanese Unexamined Patent Publication No. 2003-160354 Japanese Unexamined Patent Publication No. 2003-327446 Japanese Unexamined Patent Publication No. 2005-320225 International Publication No. 01/066647

As described above, when CeO ₂ is used as an oxidizing agent for a glass having a low environmental load to produce a high transmittance glass, it is necessary to add a large amount of CeO ₂ in order to reduce the redox ratio of iron. Patent Document 4, in the high transmission plate glass containing CeO ₂ is disclosed, not only to lower the redox ratio of iron to contain CeO _2, the visible light region due to the CeO ₂ own extinction There exists a problem that the transmittance | permeability from an ultraviolet region and the transmittance | permeability of a near infrared region will fall. In addition, a long-term stability decrease in transmittance from the visible light region to the infrared region due to solarization caused by CeO ₂ is also a problem. On the other hand, when there is light absorption in the ultraviolet region, deterioration of the resin layer of the previous solar cell module and the resin base material of the mirror module for concentrating solar power generation and concentrating solar power generation is suppressed.

Therefore, the present invention provides a glass article that has a high transmittance in the visible to infrared range while suppressing solarization while maintaining absorption in the ultraviolet range to some extent as compared with conventional CeO ₂ -containing glass. It is for the purpose.

The present inventors have found that matrix composition and CeO ₂ of the glass and controlled in the optimum range iron content, the product of the amount of the effect and Fe ³⁺ which matrix composition has on the absorption coefficient per Fe ³⁺ unit concentration in the glass By controlling according to the amount of iron contained, the absorption in the ultraviolet region in the visible region and the absorption of Fe ³⁺ caused by the addition of CeO ₂ are maintained while maintaining the absorption in the ultraviolet region to some extent as compared with the conventional CeO ₂ -containing glass. The present inventors have found that the extinction coefficient can be suppressed and the decrease in transmittance on the short wavelength side of the visible region due to solarization can be suppressed.

That is, the present invention is as follows.
1. Total oxidation converted to 50-80% of SiO ₂ , 0-10% of K ₂ O, 0-5% of B ₂ O ₃ and 0 2-5% of Fe ₂ O ₃ with the following oxide-based mass percentage display or mass ppm display iron _(t-Fe 2 _{O 3)} and 1 ~ 90 ppm, total cerium in terms of CeO ₂ and (t-CeO ₂₎ contained 100 ~ 3000 ppm, the _Sb 2 _{O 3} be substantially free glass, The glass has an iron redox ratio represented by the following formula (1) of 0% to 30%,
[(Content of divalent iron in terms of ^{_{Fe 2 O 3 (Fe 2+)}} ) / [( divalent iron in terms of ^_Fe 2 _{O 3 (Fe} ²⁺⁾ to the total amount of trivalent iron ^{(Fe 3+)} (Fe ²⁺ + Fe ³⁺ )] Formula (1),
And the glass article which consists of glass which satisfy | fills the relational expression of following formula (2) and following formula (3).
1 ≦ [t—CeO ₂ ] / [t—Fe ₂ O ₃ ] ≦ 100 Formula (2)
P <= 3000 ... Formula (3)
Here, P = [Fe ³⁺ ] × (4.5 × [MgO] + 3.9 × [CaO] + 1.7 × [SrO] + 1.9 × [BaO] + 2.7 × [Al ₂ O ₃ ] − 0.3 × [Na ₂ O] −1.5 × [K ₂ O] −1.7 × [Li ₂ O]).
In the formula (3), the content of Fe ³⁺ is expressed by mass ppm, and the other content is expressed by mass percentage based on oxide.
2. _2. The glass article according to item 1, wherein the glass contains 1 to 80 ppm of t-Fe ₂ O ₃ in mass ppm, and the parameter P satisfies a relational expression of P ≦ 2700.
3. _3. The glass article according to item 1 or 2, wherein the glass does not substantially contain B ₂ O ₃ .
4). 4. The glass article according to any one of the preceding items 1 to 3, wherein the glass further contains SO ₃ in a percentage by mass of more than 0% and 0.5% or less.
5. The glass article according to any one of the preceding items 1 to 4, wherein the glass further contains SnO ₂ in a mass percentage display of 0 to 1%.
6). 6. The glass article according to any one of items 1 to 5, wherein the glass is made of glass that satisfies a relational expression of the following formula (4).
Q ≦ 12000 Formula (4)
Here, Q = [t-CeO ₂ ] × 3.8 + [t-Fe ₂ O ₃ ] × 83.8.
In the formula (4), [t-CeO ₂ ] and [t-Fe ₂ O ₃ ] represent the contents in mass ppm based on the oxide.
7). The visible light transmittance (Tv) at an optical path length of 2 mm is 91.5% or more, the energy transmittance (Te) is 90.7% or more, and the ultraviolet light transmittance (Tuv) is 85% or less. The glass article according to any one of the preceding items 1 to 6.
8). When the glass is irradiated with a high pressure mercury lamp with an illuminance of 45 mW / cm ² for 30 seconds, the change Δ% T @ 400 nm in the optical path length of 1 mm at a wavelength of 400 nm before and after irradiation is 3% or less. 8. The glass article according to any one of 7 above.
9. 9. The glass article according to any one of items 1 to 8, which is used for a solar cell module, a concentrating solar power generation mirror module, or a concentrating solar power generation mirror module.
10. 9. A solar cell module using the glass article according to any one of items 1 to 8 as a surface material.
11. A concentrating solar power generation mirror module using the glass article according to any one of items 1 to 8 as a protective layer.
12 9. A concentrating solar power mirror module using the glass article according to any one of 1 to 8 as a protective layer.

Since the glass article of the present invention can suppress the absorption on the short wavelength side and the absorption coefficient of Fe ^{3+ in} the visible region caused by the addition of CeO ₂ , the visible light transmittance is lowered while lowering the ultraviolet light transmittance (hereinafter also referred to as Tuv). (Hereinafter also referred to as Tv) and energy transmittance (hereinafter also referred to as Te) can be maintained high, and solarization can be suppressed more than conventional CeO ₂ -containing glass.

Therefore, by using the glass article of the present invention for a solar cell module, as compared with a solar cell module using a conventional float glass, since the transmittance is higher in the visible region than in the ultraviolet region, High efficiency and difficult to solarize. Further, since the ultraviolet light transmittance is kept low, the resin layer is unlikely to deteriorate over time.

Further, by using the glass article of the present invention for the protective layer of the mirror module for concentrating solar power generation and concentrating solar power generation, compared with the mirror module using the conventional float glass, ultraviolet light is used. Since the transmittance is kept low, the deterioration of the resin base material over time can be suppressed. Moreover, since the transmittance is high and the reflectance is high, high efficiency can be realized.

The glass article of the present invention includes architectural interior and exterior applications where high transmittance is desired, cover glass and substrate glass applications, various electronic device exterior applications, and light guide plates for backlight modules of liquid crystal displays. It is suitable as a light source application of the electronic device, and particularly suitable as a surface layer for a solar cell module, and as a protective layer for a mirror module for concentrating solar power generation and concentrating solar power generation.

FIG. 1 is a cross-sectional view showing an example of an embodiment of a solar cell module according to the present invention. FIG. 2 is a cross-sectional view showing an example of an embodiment of a concentrating solar power generation mirror module according to the present invention.

In this specification, the glass article is a generic term for a flat glass plate having a predetermined thickness, a curved glass plate, a glass rod, a glass cylindrical tube, and other various glass articles. The most typical glass article in the present invention is a glass plate.

In the present specification, components of the glass, expressed in terms of oxide, such as SiO ₂ and Al ₂ O _3, the content of each component to the whole glass (glass composition), the mass percentage based on oxides, or mass It is expressed in ppm (the mass percentage may be simply expressed as%, or the mass ppm may be simply expressed as ppm).

In the present specification, “to” indicating a numerical range is used to mean that the numerical values described before and after it are used as a lower limit and an upper limit, and unless otherwise specified, hereinafter “to” "Is used with the same meaning.

Hereinafter, the glass article of the present invention will be described in detail.

The glass of the glass article of the present invention (hereinafter also referred to as the glass of the present invention) is expressed in terms of mass percentage or mass ppm based on the following oxides: 50 to 80% of SiO ₂ , 0 to 10% of K ₂ O, the _{B 2 O 3 0 ~ 5%} , Fe 2 O 3 the total iron oxide in terms of _(t-Fe 2 _{O 3)} and 1 - 90 ppm, total cerium in terms of CeO ₂ (t-CeO ₂₎ 100 to It consists of glass containing 3000 ppm and substantially free of Sb ₂ O ₃ .

The content of total iron oxide in terms of _{Fe 2 O 3 (t-Fe} 2 O 3) is not more than 90 ppm, preferably not more than 80 ppm, more preferably 60ppm or less, particularly preferably not more than 45 ppm, Most preferably, it is 35 ppm or less.

When the content of t-Fe ₂ O ₃ exceeds 90 ppm, the effect of absorption of Fe ³⁺ increases when CeO ₂ is added to lower the redox ratio of iron, and the effect of reducing Fe ³⁺ absorption by the mother composition is taken into account. Even if it is included, the decrease in Tv and Te becomes large, causing a problem in performance. Further, the content of _Fe 2 _{O 3} is in particular by at most 80ppm of _Fe 2 _{O 3,} preferably because it can achieve very high transmittance over the entire visible light region throughout.

On the other hand, the content of t-Fe ₂ O ₃ is 1 ppm or more, preferably 5 ppm or more, more preferably 8 ppm or more, and further preferably 10 ppm or more. If it is less than 1 ppm, it will be difficult to improve the solubility of the glass during the production of multi-component oxide glass, and it will be difficult to mass-produce at low cost. Moreover, it is difficult to obtain raw materials. In addition, the total iron oxide amount of glass can be adjusted with the quantity of the iron component added at the time of glass manufacture.

In the glass of the present invention, the redox ratio of iron represented by the following formula (1) is in the range of 0 to 30%.
[(Content of divalent iron in terms of ^{_{Fe 2 O 3 (Fe 2+)}} ) / [( divalent iron in terms of ^_Fe 2 _{O 3 (Fe} ²⁺⁾ to the total amount of trivalent iron ^{(Fe 3+)} (Fe ²⁺ + Fe ³⁺ )] ... Formula (1)

The iron redox ratio is preferably 25% or less, more preferably 20% or less, still more preferably 15% or less, and most preferably 12% or less. As described above, in order to increase the transmittance in the visible region, the redox ratio is preferably low. However, considering the fact that the effect of absorption due to Fe ³⁺ existing in a small amount is reduced and the solubility characteristics are improved, Fe ²⁺ is improved. In some cases, it is preferable to contain a little. In this case, the iron redox ratio is preferably 0.1% or more, and more preferably 0.5% or more.

In the present invention, the total iron oxide amount of the glass of the glass article is expressed as the amount of Fe ₂ O ₃ , but all the iron present in the glass exists as Fe ³⁺ (trivalent iron). is not. Usually, Fe ³⁺ and Fe ²⁺ (divalent iron) are simultaneously present in the glass.

Fe ²⁺ and ^{Fe 3+,} which is absorbed in the visible light region is present, the absorption coefficient of the ^{Fe 2+ (11cm -1 mol} -1) is 1 than the absorption coefficient of the ^{Fe 3+ (0.96cm -1 mol} -1) Since it is orders of magnitude larger, the internal transmittance in the visible light region is further reduced. Therefore, it is preferable that the Fe ²⁺ content is small in order to increase the internal transmittance in the visible light region.

In the glass of the present invention, the content of divalent iron (Fe ²⁺ ) converted to Fe ₂ O ₃ in terms of mass ppm is preferably 20 ppm or less, more preferably 15 ppm or less, and even more preferably 10 ppm or less. Yes, most preferably 7 ppm or less, particularly preferably 5 ppm or less.

On the other hand, since the influence of absorption by Fe ³⁺ cannot be ignored, the amount of trivalent iron converted to Fe ₂ O ₃ in terms of mass ppm in the glass of the present invention is preferably 70 ppm or less, more preferably 60 ppm or less. More preferably, it is 50 ppm or less.

In the glass of the present invention, the content of Fe ²⁺ and Fe ^{3+ in} the glass satisfies the above range, so that the absorption of light inside the glass in the wavelength range of 380 nm to 780 nm can be suppressed. Architectural interior and exterior applications that are desired, cover glass and substrate glass applications, exterior applications for various electronic devices, and light source applications for electronic devices, especially for light guide plates for backlights of liquid crystal televisions, etc. It can be used effectively for required applications.

In the glass of the present invention, the content of total cerium in terms of CeO ₂ (t-CeO ₂₎ functions as an oxidizing agent, coloring is small, it satisfies the spectral characteristics to minimize the effects of solarization And 3000 ppm or less. Preferably, it is 2000 ppm or less, More preferably, it is 1500 ppm or less, More preferably, it is 1000 ppm or less, Most preferably, it is 750 ppm or less.

The lower limit of the total cerium oxide content is 100 ppm or more, preferably 125 ppm or more, more preferably 150 wtppm or more, particularly preferably 200 wtppm or more, in order to function as an oxidant and lower the ultraviolet light transmittance. It is.

On the other hand, based on the experiments by the present inventors, it has been clarified that whether cerium oxide functions sufficiently as an oxidant depends on the total iron oxide content. The content of cerium oxide shall satisfy the range of the following formula (2) representing the ratio of the content of total cerium oxide and total iron oxide described below.
1 ≦ [t—CeO ₂ ] / [t—Fe ₂ O ₃ ] ≦ 100 Formula (2)

That is, from the viewpoint of enhancing the effect of CeO _{2 as} an oxidizing agent, the ratio of [t-CeO ₂ ] / [t-Fe ₂ O ₃ ] is 1 or more (that is, the content of t-CeO ₂ is t- It is equal to or more than the content of Fe ₂ O ₃ ), preferably 1.5 or more, more preferably 3 or more, and still more preferably 5 or more.

Further, from the viewpoint of suppressing the effects of solarization and coloring by CeO _2, the ratio of [t-CeO ₂ ] / [t-Fe ₂ O ₃ ] is 100 or less (that is, the content of t-CeO ₂ is t -Fe ₂ O ₃ content 100 times or less), preferably 45 or less, more preferably 35 or less, even more preferably 25 or less, particularly preferably 15 or less, most preferably 10 or less.

Especially when it is required that Te is high even after solarization has progressed not only immediately after glass plate production but also after long-term use for CSP and CPV applications, the content of CeO _{2 and} the content of Fe ₂ O ₃ are It is more preferable to satisfy the following relational expression (4).
Q ≦ 12000 Formula (4)
Here, Q = [t-CeO ₂ ] × 3.8 + [t-Fe ₂ O ₃ ] × 83.8.
In the formula (4), [t-CeO ₂ ] and [t-Fe ₂ O ₃ ] represent the contents in mass ppm based on the oxide.

When Q is 12000 or less, Te can be kept high even in a glass to which CeO ₂ is added. More preferably, it is 10,000 or less, More preferably, it is 8500 or less, Especially preferably, it is 6500 or less.

In order to realize the absorption coefficient suppression by Fe ³⁺ which is the effect of the present invention, the glass of the present invention satisfies the range of the following formula (3). In the following formula (3), the content of Fe ³⁺ is expressed by mass ppm, and the other content is expressed by mass percentage based on the following oxide.
[Fe ³⁺ ] × (4.5 × [MgO] + 3.9 × [CaO] + 1.7 × [SrO] + 1.9 × [BaO] + 2.7 × [Al ₂ O ₃ ] −0.3 × [ Na ₂ O] -1.5 × [K ₂ O] -1.7 × [Li ₂ O]) ≦ 3000 Formula (3)

When the left side of the formula (3) is P, P is 3000 or less, more preferably 2700 or less, still more preferably 2200 or less, and most preferably 2000 or less. P is a product of the amount of the effect and Fe ³⁺ which matrix composition has on the absorption coefficient per Fe ³⁺ unit concentration, represents the magnitude of light absorption that occurs in the visible region by Fe ^3+. When P exceeds 3000, Tv decreases.

The mother composition of the glass of the present invention can be widely selected from those composed of multi-component oxide glass and capable of obtaining the above-described high average internal transmittance in the visible light region. In particular, the multi-component oxide glass used in the glass article of the present invention has a low average content or a high average internal transmission in the visible light region, as described above, because the content of components having absorption in the visible light region is low or not included. It is preferable to satisfy the rate.

As a mother composition of the glass of a preferable glass article, those having the following composition in terms of mass percentage display based on the following oxide can be given as typical examples. This as the matrix composition is a composition excluding the total iron oxide in terms of _{Fe 2 O 3 (t-Fe} 2 O 3) and all cerium oxide in terms of _{CeO 2 (t-CeO 2)} .

In addition, the glass in the glass article of this invention is not limited to the example of the glass shown here.
SiO ₂ : 50 to 80%,
Al ₂ O ₃ : 1 to 15%,
B ₂ O ₃ : 0 to 5%
Li ₂ O: 0 to 5%,
Na ₂ O: 5 to 15%,
K ₂ O: 0 to 10%,
MgO: 0 to 15%,
CaO: 0 to 15%,
SrO: 0 to 15%,
BaO: 0 to 15%,
Li ₂ O + Na ₂ O + K ₂ O: 5-15%
MgO + CaO + SrO + BaO: 7.2 to 35%

The composition range of each component of the mother composition of the glass of the present invention described above will be described.

SiO ₂ is a main component of glass. In order to maintain the weather resistance and devitrification characteristics of the glass, the content of SiO ₂ is set to 50% or more in terms of oxide based mass percentage. 60% or more is preferable, 65% or more is more preferable, and 67% or more is more preferable.

On the other hand, the content of SiO ₂ is easy to dissolve and the foam quality is good, and the content of divalent iron (Fe ²⁺ ) in the glass is kept low, and the optical properties are good. Therefore, it is 80% or less. 75% or less is preferable, 74% or less is more preferable, and 72% or less is more preferable.

Al ₂ O ₃ is a component that improves the weather resistance of the glass. In order to maintain practically necessary weather resistance in the glass composition system of the present invention, the content of Al ₂ O ₃ is preferably 1% or more, more preferably 1.5% or more, Preferably it is 2.5% or more.

However, the content of Al ₂ O ₃ is preferably 15% or less in order to keep the content of divalent iron (Fe ²⁺ ) low, the optical properties to be good, and the foam quality to be good. The following is more preferable, 8% or less is further preferable, and 5% or less is particularly preferable.

B ₂ O ₃ is a component that promotes melting of the glass raw material and improves mechanical properties or weather resistance. However, the addition of the soda lime silicate glass such as the glass of the present invention causes striae due to volatilization. In order not to cause inconvenience such as generation of (ream) and erosion of the furnace wall, the content is 5% or less, preferably 2% or less, more preferably 1% or less, and particularly not substantially contained. preferable.

Hereinafter, in the present specification, “substantially does not contain” means that it does not contain except inevitable impurities.

Alkali metal oxides such as Li ₂ O, Na ₂ O and K ₂ O are components useful for promoting melting of the glass raw material and adjusting thermal expansion or viscosity. Therefore, the total content of these alkali metal oxides (Li ₂ O + Na ₂ O + K ₂ O) is preferably 5% or more, more preferably 7% or more, further preferably 9% or more, and particularly preferably 10% or more. However, in order to maintain the chemical durability of the glass, Li ₂ O + Na ₂ O + K ₂ O is preferably 15% or less, more preferably 13.5% or less, further preferably 13% or less, and 12.5% or less. Is particularly preferred.

Li ₂ O is a component useful for promoting melting of the glass raw material and adjusting thermal expansion or viscosity. However, 5% or less is preferable, 2.5% or less is more preferable, and 2% or less is more preferable in order to facilitate vitrification, to suppress the iron content contained as an impurity derived from the raw material, and to reduce the batch cost. Preferably, 1% or less is most preferable.

Na ₂ O is a useful component for promoting melting of the glass raw material and adjusting thermal expansion or viscosity. 5% or more is preferable. It is more preferably 7% or more, more preferably 9% or more, and particularly preferably 10% or more. However, 15% or less is preferable in order to maintain the chemical durability of the glass. 13.5% or less is more preferable, 13% or less is further preferable, and 12.5% or less is particularly preferable.

K ₂ O is a component useful for promoting melting of the glass raw material and adjusting thermal expansion or viscosity. However, in order to maintain the weather resistance and devitrification characteristics of the glass, it is 10% or less, preferably 7.5% or less, more preferably 5% or less. Further, in order to suppress the batch cost, 3% or less is particularly preferable, and 2% or less is particularly preferable.

Alkaline earth metal oxides such as MgO, CaO, SrO and BaO are useful components for accelerating melting of glass raw materials and adjusting thermal expansion, viscosity and the like. Therefore, the total content of these alkaline earth metal oxides (MgO + CaO + SrO + BaO) is preferably 7.2% or more, more preferably 8% or more, further preferably 13% or more, particularly preferably 14% or more, Most preferred is 15% or more.

However, (MgO + CaO + SrO + BaO) is preferably 35% or less, more preferably 30% or less, and even more preferably 25% or less in order to keep the coefficient of thermal expansion low, to improve the devitrification characteristics and maintain strength. It is preferably 23% or less, and most preferably 22% or less.

MgO has the effect of lowering the viscosity during glass melting and promoting melting. Moreover, there exists an effect | action which reduces specific gravity and makes a glass article hard to be damaged.

In order to lower the coefficient of thermal expansion of the glass and to improve the devitrification properties, the content of MgO is preferably 15% or less, more preferably 12% or less, and 7.5% or less. Preferably, it is 5% or less. More preferably, it is 3% or less, and most preferably 2% or less.

CaO can be contained because it is a component that promotes melting of the glass raw material and adjusts viscosity or thermal expansion. In order to obtain the above action, the content is preferably 3% or more, more preferably 5% or more, further preferably 6% or more, and particularly preferably 7% or more. In order to improve the devitrification property, 15% or less is preferable, 14% or less is more preferable, and 13% or less is more preferable.

SrO has the effect of increasing the thermal expansion coefficient and lowering the high temperature viscosity of the glass. In order to acquire the said effect, it is preferable to contain 2% or more. However, in order to keep the thermal expansion coefficient of the glass low, it is preferably 15% or less, more preferably 8% or less, and even more preferably 6% or less.

BaO, like SrO, has the effect of increasing the coefficient of thermal expansion and lowering the high temperature viscosity of the glass. In order to acquire the said effect, it is preferable to contain 2% or more. However, in order to keep the thermal expansion coefficient of the glass low, it is preferably 15% or less, more preferably 8% or less, and even more preferably 6% or less.

Since Sb ₂ O ₃ has a problem of coloring in a float bath and has a high environmental load, Sb ₂ O ₃ is not substantially contained in the mother composition of the glass of the present invention.

In the mother composition of the glass of the present invention, the following ZrO ₂ , SnO ₂ , SO ₃ and As ₂ O ₃ components may be contained as optional components.

For example, the glass of the present invention may contain ZrO ₂ in order to improve the heat resistance and surface hardness of the glass. However, it is preferably not contained from the viewpoint of maintaining devitrification characteristics and maintaining low density. The ZrO ₂ content is preferably 0 to 10% or less in terms of mass percentage. 5% or less is more preferable, 3% or less is more preferable, 2% or less is especially preferable, and it is still more preferable not to contain substantially.

Further, the glass of the present invention may contain SnO ₂ as a fining agent. In this case, the total tin content converted to SnO ₂ is preferably 0 to 1% in terms of mass percentage. 0.5% or less is more preferable, 0.2% or less is more preferable, 0.1% or less is especially preferable, and it is further more preferable not to contain substantially.

The glass of the present invention may contain SO ₃ as a fining agent. In this case, the SO ₃ content is preferably more than 0% and 0.5% or less in terms of mass percentage. It is more preferably 0.3% or less, further preferably 0.2% or less, and further preferably 0.1% or less.

Further, the glass of the present invention may contain As ₂ O ₃ as an oxidizing agent and / or clarifying agents. In this case, the content of As ₂ O ₃ is preferably 0 to 0.5% in terms of mass percentage. 0.2% or less is more preferable, 0.1% or less is more preferable, and it is further more preferable not to contain substantially.

However, since SnO ₂ and As ₂ O ₃ described above also act as an oxidizing agent for glass, they may be added within the above range for the purpose of adjusting the amount of Fe ^{2+ in} the glass. However, As ₂ O ₃ is not positively contained from the environmental viewpoint.

The glass article of the present invention is particularly used when used as a surface layer of a solar cell module or a protective layer of a mirror module for concentrating solar power generation or concentrating solar power generation from the viewpoint of energy efficiency and ultraviolet blocking performance. Preferably have the following characteristics.

When the glass article of the present invention is used as a surface material of a solar cell module, or as a protective layer of a mirror module for concentrating solar power generation or concentrating solar power generation, the glass plate is a substantially rectangular plate It is preferable that

The thickness of the glass plate is preferably 0.1 mm or more, more preferably 0.5 mm or more. Although an upper limit is not specifically limited, Usually, it is 6 mm or less. In the case of a light guide, the thickness of the glass plate corresponds to the length in the vertical direction. The internal transmittance of the glass plate is also affected by the thickness of the glass plate.

When the thickness of the glass plate is 6 mm or less, the surface of the solar cell module or the protective layer of the mirror module for concentrating solar power generation or concentrating solar power generation is used on the glass surface. An increase in the number of reflections is prevented, an increase in attenuation due to reflection is suppressed, and an internal transmittance at an effective optical path length is improved, so that a required internal transmittance can be easily achieved. Moreover, the glass breakage can be suppressed by setting the thickness of the glass plate to 0.5 mm or more.

The glass article of the present invention has a visible light transmittance (Tv) of 91.5% or more, an energy transmittance (Te) of 90.7% or more, and an ultraviolet light transmittance (Tuv) of 85% at an optical path length of 2 mm. The following is preferable.

When the visible light transmittance (Tv) at an optical path length of 2 mm is 91.5% or more, high efficiency is obtained when used in a solar cell module, a concentrating solar power generation or a concentrating solar power mirror module. can get. More preferably, it is 91.6% or more, More preferably, it is 91.7% or more.

When the energy transmittance (Te) at an optical path length of 2 mm is 90.7% or more, high efficiency is obtained when used in a solar cell module, a concentrating solar power generation or a concentrating solar power mirror module. It is done. More preferably, it is 91.0% or more, further preferably 91.3% or more, and particularly preferably 91.5% or more. Although an upper limit is not specifically limited, Usually, it is 93.0% or less.

When the ultraviolet light transmittance (Tuv) at an optical path length of 2 mm is 85% or less, the resin layer of the solar cell module or the resin base material of the mirror module for concentrating solar power generation and concentrating solar power generation Deterioration due to ultraviolet rays can be suppressed. More preferably, it is 82% or less, More preferably, it is 80% or less.

The glass preferably has a transmittance change Δ% T @ 400 nm of 3% or less at an optical path length of 1 mm at a wavelength of 400 nm before and after irradiation when irradiated with a high-pressure mercury lamp with an illuminance of 45 mW / cm ² for 30 seconds. More preferably, it is 2% or less, more preferably 1.5% or less, and particularly preferably 1.25% or less. When the Δ% T @ 400 nm is 3% or less, a decrease in transmittance due to solarization of CeO ₂ caused by ultraviolet irradiation is suppressed as compared with the conventional CeO ₂ -added highly transmissive glass.

The glass article of the present invention has a high Tv, Te and a low Tuv at the same time as the conventional high-transmission glass at the stage immediately after production. Since it is equal to or higher than that of highly transmissive glass and Tuv is further lower than that immediately after production, it can be expected to suppress deterioration of the resin base material when used for a mirror module for CSP and CPV, for example. When it is more preferable that the Tuv is low, solarization may be intentionally induced by irradiating the glass plate with ultraviolet rays in advance.

When the glass article of the present invention is used as a substantially rectangular flat glass plate for a solar cell module, or for a concentrating solar power generation or a concentrating solar power mirror module, the glass It is preferable that at least one side of the end face of the plate, more preferably at least the end face on the side on which sunlight is incident, be polished.

The polishing finish can increase the incident efficiency of light from the sun and improve the strength of the glass plate. In the present specification, an arithmetic average roughness Ra of 0.1 μm or less is polished.

When the glass article of the present invention is a glass plate, specific examples of the method for producing the glass plate include the following methods. Total iron oxide converted to 50-80% of SiO ₂ , 0-10% of K ₂ O, 0-5% of B ₂ O ₃ , and Fe ₂ O ₃ in mass percentage display or mass ppm display based on oxide (T-Fe ₂ O ₃ ) 1 to 90 ppm, total cerium oxide converted to CeO ₂ (t-CeO ₂ ) 100 to 5000 ppm, so that the glass does not substantially contain Sb ₂ O ₃ , Glass raw materials are prepared, and the obtained glass batch is melted to obtain molten glass.

Thereafter, the molten glass is molded using a float process to obtain a glass plate.

The range of the preferable composition of the glass used in the manufacturing method of an above described glass plate is as follows.
With the following oxide percentage mass display or mass ppm display,
SiO ₂ : 50 to 80%,
Al ₂ O ₃ : 1 to 15%,
B ₂ O ₃ : 0 to 5%
Li ₂ O: 0 to 5%,
Na ₂ O: 5 to 15%,
K ₂ O: 0 to 10%,
MgO: 0 to 15%,
CaO: 0 to 15%,
SrO: 0 to 15%,
BaO: 0 to 15%,
Li ₂ O + Na ₂ O + K ₂ O: 5-15%
MgO + CaO + SrO + BaO: 7.2 to 35%,
Total iron oxide converted to Fe ₂ O ₃ : 1 to 90 ppm,
All cerium oxide in terms of CeO _2: 100 ~ 3000ppm

FIG. 1 is a cross-sectional view showing an example of an embodiment of a solar cell module according to the present invention. The solar cell module 1 is composed of a pair of front surface material 10 and back surface material 12 which are made of glass substrates facing each other at a predetermined interval; and is sandwiched between the front surface material 10 and the back surface material 12 and is formed inside these sealing regions. A resin layer 20 extending along these surfaces; a solar cell element 30; and a wiring (not shown) connected to the solar cell element 30 and extending to the outside.

The glass article of the present invention can be used as the surface material 10 of the solar cell module 1. The thickness of the surface material 10 is preferably 0.5 to 6 mm, more preferably 0.8 to 3.2 mm, and still more preferably 1.5 to 2.5 mm. The back material 12 is a glass substrate. Examples of the glass substrate material include soda lime glass and alkali-free glass. The thickness of the back material 12 is usually preferably 0.5 to 6 mm.

The thickness of the resin layer 20 can be a required thickness according to the purpose, and is preferably 0.05 to 2 mm, more preferably 0.3 to 0.8 mm. As a material for the resin layer, a sealing material film (for example, EVA and PVB) is preferable in order to ensure mechanical strength.

The solar cell element 30 has a surface electrode layer, a photoelectric conversion layer, and a back electrode layer in order from the surface side of the surface material 10. The photoelectric conversion layer is a layer made of a semiconductor.

Examples of the semiconductor include a single crystal silicon semiconductor and a polycrystalline silicon semiconductor. Examples of the material for the electrode layer include silver and aluminum. As the solar cell element, a single crystal or polycrystalline silicon solar cell element is preferable.

The shape of the solar cell module 1 is usually rectangular. The solar cell module 1 can be manufactured with a size of 0.1 m × 0.1 m, but is preferably 0.5 m × 0.5 m or more in consideration of productivity and power generation efficiency at the time of installation. The upper limit of the size of the solar cell module 1 is often determined by restrictions on the size of a manufacturing device such as a decompression device. In addition, a too large solar cell module tends to be difficult to handle in installation or the like. The upper limit of the size of the solar cell module 1 is usually preferably about 3 m × 3 m due to these restrictions.

The shape or size of the surface material 10 and the back material 12 are substantially equal to the shape and size of the solar cell module 1, and the shape or size of the surface material 10 and the back material 12 may be slightly different.

FIG. 2 is a cross-sectional view showing an example of an embodiment of a concentrating solar power generation mirror module according to the present invention. The concentrating solar power generation mirror module 2 has at least an adhesive layer (not shown), a metal reflection layer 60, and a protective layer 40 on the light source side of the metal reflection layer 60 on the resin base material 50. .

In addition to the above layers, other various functional layers such as a metal corrosion prevention layer may be provided depending on the purpose. In addition, although the concentrating solar power generation mirror module has been described here, the embodiment of the concentrating solar power generation mirror module according to the present invention is substantially the same.

The glass article of the present invention can be used as the protective layer 40 of the concentrating solar power generation mirror module 2. The thickness of the protective layer 40 is preferably 0.1 to 6 mm, more preferably 0.5 to 5 mm, and still more preferably 0.9 to 4 mm.

As the resin base material 50, conventionally known various resin films can be used. For example, an epoxy resin-based film, an alkyd resin-based film, a melamine resin-based film, an acrylic resin-based film, a fluororesin-based film, or the like can be given. The thickness of the resin base material 50 is preferably set to an appropriate thickness according to the type and purpose of the resin. In general, the thickness is preferably 10 to 300 μm.

The metal reflection layer 60 is a layer made of metal or the like having a function of reflecting sunlight. The surface reflectance of the metal reflective layer is preferably 80% or more, more preferably 90% or more. The metal reflection layer 60 is preferably formed of a material containing at least one element selected from the element group consisting of Ag, Cu, Al, Cr, Ni, Ti, Mg, Rh, Pt, and At. The metal reflection layer 60 may be formed of two or more metal thin films.

Hereinafter, examples of the present invention will be described.

The raw materials of each component were prepared so as to have a target composition, and were melted at 1350 ° C. for 1 hour using a platinum crucible. In the dissolution, 400 g of the raw material was added in three portions every 20 minutes. The obtained melt was continuously heated to a predetermined temperature of 1450 to 1650 ° C. over 1 hour, and then allowed to stand for 3 hours. The melting temperature at the second stage was appropriately selected according to the clarity of the glass.

The glass melt was poured out onto a preheated carbon mold, formed into a plate shape, and then slowly cooled. The kind of raw material was selected from cinnabar sand, aluminum oxide, sodium carbonate, and other commonly used glass raw materials. In addition, a raw material having a particle size in the range of 1 to 1000 μm was used, and 0.3% by mass of sodium sulfate decahydrate was added as a clarifying agent.

The obtained glass block was cut, a part thereof was polished, and the content (mass ppm) of total iron oxide converted to Fe ₂ O ₃ was determined by a fluorescent X-ray analyzer. The content of Fe ²⁺ was measured according to ASTM C169-92 (2011). The measured Fe ²⁺ content was expressed in terms of Fe ₂ O ₃ .

When the Fe ²⁺ content in the glass was less than 4.0 ppm by mass, the Fe ²⁺ amount was determined by the following method. First, Fe ²⁺ content C was measured by a method according to ASTM C169-92 (2011) with respect to glass prepared by adjusting the total iron content with the same glass mother composition and preparing Fe ²⁺ content exceeding 4.0 mass ppm. _{Fe2 +} (mass ppm) was measured.

The spectral transmittance of this glass in the wavelength range of 1000 to 1250 nm was measured according to the spectroscopic measurement method described later. Since the minimum value% T _MIN of the transmittance in this range is proportional to the Fe ²⁺ content in the glass, the calibration curve Y = (C _{Fe 2+} /% T _MIN ) × X is used to contain Fe ^{2+ in} the glass. The amount was calculated from the spectroscopic measurement results.

Here, X is the minimum value of the spectral transmittance in the wavelength range of 1000 to 1250 nm of glass whose Fe ²⁺ content is less than 4.0 mass ppm, and Y is the Fe ²⁺ content contained in the glass. The total cerium oxide content converted to CeO ₂ was determined by ICP emission analysis.

A glass plate for measurement in which a part of the obtained glass block is optically homogenous with no striae or the like visually observed and polished so that the main surface becomes a mirror surface with a thickness of 2 mm. Produced. With respect to this glass plate, spectral transmittance at a length of 2.0 mm was measured using Hitachi High-Tech U-4100. From the obtained spectral transmittance spectrum, Tv and Te were calculated by a method according to JIS-R3106 (1998), and Tuv was calculated by a method according to ISO-9050 (2003).

About the obtained glass plate, in order to evaluate the influence of the transmittance | permeability fall by ultraviolet irradiation, the ultraviolet irradiation test was also implemented together. This ultraviolet irradiation test was performed as follows. A glass plate sample with a thickness of 1 mm is irradiated with a high-pressure mercury lamp to an illuminance of 45 mW / cm ^{2 on} the surface of the glass plate for 30 seconds, and the change in transmittance at a wavelength of 400 nm before and after irradiation Δ% T @ 400 nm was measured.

Tables 1 to 3 show the glass compositions (unit: mass%) of Examples 1 to 22, and the total iron oxide (t-Fe ₂ O ₃ ) content converted to Fe ₂ O ₃ as the iron content in the glass ( unit: ppm), the total content of cerium oxide in terms of _{CeO 2 (t-CeO 2)} ( unit: ppm), the redox ratio of iron _{(Fe-redox), [t} -CeO 2] / [t-Fe 2 O ₃ ], left side of formula (3) {[Fe ³⁺ ] × (4.5 × [MgO] + 3.9 × [CaO] + 1.7 × [SrO] + 1.9 × [BaO] + 2.5 × [ Al ₂ O ₃ ] −0.3 × [Na ₂ O] −1.5 × [K ₂ O] −1.7 × [Li ₂ O])}, the left side of equation (4) together showing a parameter Q which is calculated by _{{[t-CeO 2] ×} 3.8 + [t-Fe 2 O 3] × 83.8}, these gases Scan the ultraviolet radiation transmittance variation Δ% T @ 400nm before and after the sample, and Tuv in an optical path length of 2 mm, indicating the Tv and Te. The glass compositions of Examples 1 to 22 do not substantially contain Sb ₂ O ₃ .

In Tables 1 to 3, Examples 1 to 18 are Examples, and Examples 19 to 22 are Comparative Examples. In Tables 1 to 3, “-” indicates that it has not been evaluated.

As shown in Tables 1 to 3, the compositions of Examples 1 to 18 have an absorption coefficient per unit concentration of Fe ³⁺ unit concentration under conditions where the total iron oxide amount is 1 to 90 ppm and the total cerium oxide amount is 100 to 3000 ppm. It was found that P ≦ 3000, which is the product of the effect on the amount of Fe ^{3+ and} the amount of Fe ³⁺ , so that the extinction coefficient of Fe ³⁺ can be suppressed.

According to the present invention, the base composition and the amount of CeO ₂ glass and controlled in the optimum range iron content, the product of the amount of the effect and Fe ³⁺ which matrix composition has on the absorption coefficient per Fe ³⁺ unit concentration in the glass By controlling according to the amount of iron contained, the absorption on the short wavelength side caused by the addition of CeO ₂ and the absorption coefficient of Fe ³⁺ are suppressed as compared with conventional CeO ₂ -containing glass while suppressing solarization. In addition, a high transmittance glass article can be provided.

The glass article of the present invention can be suitably used for those which are desired to have high transmittance. Especially suitable for interior and exterior use for buildings, use for cover glass and substrate glass, exterior use for various electronic devices, and light source use for electronic devices. For example, surface materials for solar cell modules and for concentrating solar power generation And it is suitable as a protective layer of the mirror module for concentrating solar power generation.

Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. Note that this application is based on a Japanese patent application filed on April 3, 2015 (Japanese Patent Application No. 2015-077046) and a Japanese patent application filed on September 2, 2015 (Japanese Patent Application No. 2015-172928). Which is incorporated by reference in its entirety. Also, all references cited herein are incorporated as a whole.

DESCRIPTION OF SYMBOLS 1 Solar cell module 2 Condenser type solar power generation mirror module 10 Surface material 12 Back surface material 20 Resin layer 30 Solar cell element 40 Protective layer 50 Resin base material 60 Metal reflective layer

Claims (12)

Total oxidation converted to 50-80% of SiO ₂ , 0-10% of K ₂ O, 0-5% of B ₂ O ₃ and 0 2-5% of Fe ₂ O ₃ with the following oxide-based mass percentage display or mass ppm display iron _(t-Fe 2 _{O 3)} and 1 ~ 90 ppm, total cerium in terms of CeO ₂ and (t-CeO ₂₎ contained 100 ~ 3000 ppm, the _Sb 2 _{O 3} be substantially free glass, The glass has an iron redox ratio represented by the following formula (1) of 0% to 30%,
[(Content of divalent iron in terms of ^{_{Fe 2 O 3 (Fe 2+)}} ) / [( divalent iron in terms of ^_Fe 2 _{O 3 (Fe} ²⁺⁾ to the total amount of trivalent iron ^{(Fe 3+)} (Fe ²⁺ + Fe ³⁺ )] Formula (1),
And the glass article which consists of glass which satisfy | fills the relational expression of following formula (2) and following formula (3).
1 ≦ [t—CeO ₂ ] / [t—Fe ₂ O ₃ ] ≦ 100 Formula (2)
P <= 3000 ... Formula (3)
Here, P = [Fe ³⁺ ] × (4.5 × [MgO] + 3.9 × [CaO] + 1.7 × [SrO] + 1.9 × [BaO] + 2.7 × [Al ₂ O ₃ ] − 0.3 × [Na ₂ O] −1.5 × [K ₂ O] −1.7 × [Li ₂ O]).
In the formula (3), the content of Fe ³⁺ is expressed by mass ppm, and the other content is expressed by mass percentage based on oxide. The glass article according to claim 1, wherein the glass contains 1 to 80 ppm of t-Fe ₂ O ₃ in terms of mass ppm, and the parameter P satisfies a relational expression of P ≦ 2700. The glass article according to claim 1 or 2, wherein the glass does not substantially contain B ₂ O ₃ . The glass article according to any one of claims 1 to 3, wherein the glass further contains SO ₃ in a percentage by mass of more than 0% and 0.5% or less. The glass article according to any one of claims 1 to 4, wherein the glass further contains SnO ₂ in a mass percentage display of 0 to 1%. The glass article according to any one of claims 1 to 5, wherein the glass is made of glass that satisfies a relational expression of the following formula (4).
Q ≦ 12000 Formula (4)
Here, Q = [t-CeO ₂ ] × 3.8 + [t-Fe ₂ O ₃ ] × 83.8.
In the formula (4), [t-CeO ₂ ] and [t-Fe ₂ O ₃ ] represent the contents in mass ppm based on the oxide. The visible light transmittance (Tv) at an optical path length of 2 mm is 91.5% or more, the energy transmittance (Te) is 90.7% or more, and the ultraviolet light transmittance (Tuv) is 85% or less. The glass article according to any one of claims 1 to 6. 2. The glass has a transmittance change Δ% T @ 400 nm of 3 mm or less at an optical path length of 1 mm at a wavelength of 400 nm before and after irradiation when irradiated with a high-pressure mercury lamp having an illuminance of 45 mW / cm ² for 30 seconds. The glass article according to any one of 1 to 7. The glass article according to any one of claims 1 to 8, which is used for a solar cell module, a concentrating solar power generation mirror module, or a concentrating solar power generation mirror module. A solar cell module using the glass article according to any one of claims 1 to 8 as a surface material. A condensing solar power generation mirror module using the glass article according to any one of claims 1 to 8 as a protective layer. A concentrating solar power generation mirror module using the glass article according to any one of claims 1 to 8 as a protective layer.

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