KR100990875B1 - Photovoltaic low iron flat glass batches containing alkali-free alumino-borosilicate display glass cullet - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low iron high-permeability soda lime silicate-based plate glass badge composition for solar cell substrates or covers made of alkali-free alumina borosilicate glass used in thin film transistor liquid crystal displays, and more particularly, low iron soda for solar cells. Lime silicate-based glass sheet composition, 32 to 36 parts by weight of soda ash, 0.5 to 1.5 parts by weight of manganese, alkali-free alumina borosilicate based display when 100 parts by weight of silica sand, silica or a mixture of silica and silica in the badge composition Provided is a low iron soda-lime silicate-based plate glass composition for solar cells, which is made of an alkali-free alumina borosilicate-based display cullet containing 3 to 24 parts by weight of cullet, limestone, and magnesite and dolomite.
From this, it is possible to reduce the generation of waste by exploring the recycling method of the cullet generated in the thin film transistor liquid crystal display glass manufacturing process and discarded as it is, and to actually apply it, and natural or used in the conventional solar glass manufacturing process Compared to the chemical raw material, the glass material of higher quality can be supplied at a lower cost by lowering the manufacturing cost of the glass badge composition and improving the physical properties of the final glass product.

Description

Photovoltaic low iron flat glass batches containing alkali-free alumino-borosilicate display glass cullet using alkali-free alumina borosilicate display cullet as a raw material

The present invention is to recycle the cullet produced in the commercial production process of low iron non-alkali alumina borosilicate glass for use in the thin film transistor liquid crystal display as a raw material of low iron soda lime silicate solar cell substrate or plate glass, glass It relates to a badge composition for maintaining or improving the manufacturing process and the physical and chemical properties of.

A cullet is defined as defective glass, shattered glass, glass shavings or crushed products of glass products. Such cullet inevitably occurs in the manufacturing and processing of glass or glass products, but in general, cullet in the glass industry Is considered a material that can be recycled as a raw material and is very important to manage.

In particular, the alkali-free alumina borosilicate-based display glass used for thin film transistor liquid crystal display plays a role in protecting the display's core parts and transmitting images, so that even small defects do not occur. Therefore, it is manufactured in comparison with general window glass or tableware glass. The process or quality control is very strict. Therefore, in the manufacturing and processing process of the substrate glass, dissolution, appearance defects and dimensional defects, etc., should be regarded as a defective product and disposed of, and a large amount of cullet is generated in this process. However, in order to ensure the continuous quality as the display glass, once the defective display glass is culletized, it is not recycled again in the manufacturing process of the display glass, and these cullet is discarded as it is by landfilling, which amounts to a considerable amount.

The alkali-free alumina borosilicate display glass does not contain any alkali in its component, and the content of Fe ₂ O ₃ present as an impurity ranges from 0.015 parts by weight (150 ppm) to 0.02 parts by weight (200 ppm) and is extremely low. ₂ , Al ₂ O ₃ , alkaline (MgO + CaO + SrO + BaO) and B ₂ O ₃ are the major components, and because these components are well mixed through the melting process, they are highly homogeneous glass. On the other hand, solar cell glass is soda-lime silicate-based glass, which is used for substrate or cover depending on the type of solar cell. SiO ₂ , CaO, MgO, Na ₂ O is the main component and the glass which affects photoelectric efficiency of solar cell In order to increase the solar transmittance, the content of Fe ₂ O _{3, which} is an impurity, is limited to 0.02 parts by weight (200 ppm) or less, and Al ₂ O ₃ is considered in consideration of moisture in rain, snow, or air, which affects the erosion of the glass surface. To adjust the content of 1 to 2 parts by weight to improve weather resistance. Accordingly, the low iron display cullet may be a part of a raw material, that is, a badge composition, required to manufacture a low iron soda-lime silicate-based solar cell glass by controlling an appropriate amount.

Therefore, there is a growing interest in recycling such an alkali-free alumina borosilicate-based display cullet, and there is a need to continuously discover and apply a method and a field capable of recycling the cullet without discarding it.

As a conventional technique related to the recycling of alkali-free alumina borosilicate-based display cullet, Korean Patent No. 10-0917269 describes a "badge composition of borosilicate long-fiber glass made from cullet of a thin film transistor liquid crystal display glass substrate". As disclosed, the above technique relates to a method for regenerating cullet generated in a process of manufacturing a substrate glass for a thin film transistor liquid crystal display, wherein the sheet contains a alkali-free alumina borosilicate-based display glass as a badge composition member of long-fiber glass. It is a feature of the technology and is not related to the application to low iron solar cell glass.

In addition, as a conventional technique related to the recycling of alkali-free alumina borosilicate-based display cullet, Korean Patent No. 10-0929869, "Soda-lime borosilicate-based short fiber glass badge composition using the cullet of the thin film transistor liquid crystal display glass substrate. "The above technique features an economical badge composition that uses an alkali-free alumina borosilicate-based display cullet as a feedstock for B ₂ O ₃ and Al ₂ O ₃ , the necessary components of short fiber glass. have.

As a conventional technology related to soda lime silicate-based glass for solar cells, Korean Patent Publication No. 10-2009-0132742 discloses a "high-transmissive colorless soda-lime glass composition", and the above technique is used to obtain high visible light transmittance. ₂ O ₃ It relates to a glass composition characterized by containing 0.01 to 0.3 parts by weight of MnO ₂ in addition to 0.01 to 0.05 parts by weight, irrespective of the recycling of alkali-free alumina borosilicate-based display cullet.

In addition, as a related art related to soda-lime silicate-based glass for solar cells, PCT WO 2007/106223 Al describes "Low Irion High Transmission Float Glass for Solar Cell Application and Method of Making Same) ", the above technique does not contain Al ₂ O ₃ and Fe ₂ O ₃ It is characterized by a soda-lime silicate-based glass composition containing 0.001 to 0.1 parts by weight, irrespective of the application of alkali-free alumina borosilicate-based display cullet.

In addition, as a related art related to glass for solar cells, Japanese Patent Application Laid-Open No. 2008-280189 discloses "a solar cell glass substrate and a manufacturing method", and the above technique includes SiO ₂ , Al ₂ O ₃ , Na ₂ O, and K _2. In the range of O component, the glass composition is completely different from the conventional soda-lime silicate glass.

In view of the patented meaning of the recycling technology of an alkali-free alumina borosilicate thin film transistor liquid crystal display glass substrate for the above-described fiber glass manufacturing, the alkali-free alumina borosilicate display cullet as described in the present invention Incorporated into a badge composition for producing a low iron soda lime silicate-based plate glass for batteries, a method for producing a plate glass having a low production cost and high quality therefrom, and a badge composition for the same, also an alkali-free alumina borosilicate system It is a technology that has great significance as it can actively foster the recycling field of display cullet.

The present invention has been made to solve the problems described above, the present invention is a raw material for the production of low iron soda lime silicate-based glass for solar cells silica or silica, limestone, dolomite or magnesite, alumina or aluminum hydroxide and the like It is an object of the present invention to provide a glass badge composition that can at least not damage or further enhance the physical and chemical properties, quality, etc. of the pane, even though some or all of the alkali-free alumina borosilicate-based display cullet is replaced.

In addition, the present invention can maintain the existing solar glass sheet manufacturing process and process parameters as possible despite the use of alkali-free alumina borosilicate-based display cullet, introducing a new process according to a new composition or expansion of a new line Another aim is to provide an economical glass badge composition that does not need to be.

Another object of the present invention is to provide a glass badge composition which can reduce raw material costs and lower manufacturing costs by directly recycling an alkali-free alumina borosilicate display cullet disposed of as it is.

In addition, the present invention, by using the composition of the alkali-free alumina borosilicate-based display cullet as an alternative raw material without having to separately manage some raw materials that are difficult to handle in the manufacturing process of the glass, resulting from the procurement, handling, storage, etc. of the raw materials It is another object to achieve a process economy, such as simplification of the process, by eliminating the difficulties and by eliminating the additional facilities required when the raw materials are separately managed.

In order to achieve the above object, the present invention, in the low iron soda lime silicate-based plate glass composition for solar cells, soda ash 32 to 36 when the silica composition, silica or a mixture of silica and silica in the badge composition to 100 parts by weight Parts by weight, 0.5 to 1.5 parts by weight, alkali-free alumina borosilicate-based display cullet, 3 to 24 parts by weight, alkali-free alumina borosilicate-based display cullet containing any one selected from limestone and magnesite and dolomite Provided is a low iron soda lime silicate plate glass badge composition for a solar cell.

When 100 parts by weight of the silica sand, silica or a mixture of silica and silica, the limestone is preferably 21 to 22 parts by weight, and the magnesite is 5 to 6 parts by weight.

When 100 parts by weight of the silica sand, silica or a mixture of silica sand and silica, the limestone is preferably 7 to 9 parts by weight, dolomite 23 to 27 parts by weight is included.

The plate glass manufactured by melting the low iron soda lime silicate-based plate glass composition for solar cells, when the plate glass is 100 parts by weight, SiO ₂ 70 to 75 parts by weight, Fe ₂ O ₃ 0.013 to 0.018 parts by weight, Al ₂ O ₃ 0.5 to 2 parts by weight, B ₂ O ₃ 0.1 to 1.3 parts by weight, Na ₂ O and K ₂ O 12 to 14 parts by weight, MgO, CaO, SrO, and BaO 10 to 13 parts by weight, SrO 0.01 to 1 parts by weight It is desirable to be.

As described above, the present invention partially replaces the raw material for manufacturing low iron soda-lime silicate-based glass for solar cells with alkali-free alumina borosilicate-based display cullet, but does not impair or further enhance the manufacturing process and physical and chemical properties of the glass. By providing the prepared badge composition, it is possible to lower the manufacturing cost of the glass, and to greatly reduce the environmental burden caused by the disposal or landfill of the alkali-free alumina borosilicate-based display cullet.

That is, a portion of or all of the silica sand, limestone, dolomite or magnesite and alumina is replaced by an alkali-free alumina borosilicate-based display cullet in a badge composition which increases the weight of the alkali-free alumina borosilicate-based display cullet in a limited range. It not only improves the physical properties of the glass produced from the composition, but also significantly reduces the manufacturing cost of the glass by reducing energy required for melting and clarifying the badge, eliminating devitrification, and the like. In addition, the concentration of impurity Fe ₂ O ₃ is extremely low and contains a high homogeneity of B ₂ O ₃ , due to the use of the excellent homogeneity of the cullet, resulting in the increase in solar transmittance and chemical durability resulting from the improved glass glass function The same positive effect can be achieved.

In particular, raw materials containing impurities such as Fe ₂ O ₃ have to be removed through a separate and difficult purification process, and the use of alkali-free alumina borosilicate-based display cullet can be applied to solar panel glass without this process. There is an effect that can minimize the mixing of impurities.

In addition, since a substantial portion of the raw material or components constituting the badge composition is replaced with cullet, many of the problems arising during the procurement, handling, storage and input of the raw material can be eliminated, which is very advantageous in the process.

Hereinafter, the present invention will be described in more detail based on the preferred embodiments.

In preparing an alkali-free alumina borosilicate display wave soda lime silicate-based solar cell sheet glass to the glass as a raw material, B ₂ O there is _{the three} components are added accompanied by, the two of the solar cell glass properties amount incorporated to the extent that does not change B ₂ O ₃ is the weather resistance of solar cell glass (corrosion resistance to water such as rain, snow, humidity) by checking the movement of alkali components such as Na ₂ O and K ₂ O contained in glass like Al ₂ O ₃ component existing Plays a big role in improving

However, the use of boric acid or borax, which is a separate feedstock in the manufacture of conventional glass, such B ₂ O ₃ , the following problems occur.

1) Since B ₂ O ₃ is hygroscopic, it is vulnerable to moisture, which may cause problems in handling and storage of the raw material.

2) The raw materials are scattered during the melting process for the production of plate glass and released to the outside in the form of particles, causing air pollution.

3) The above raw materials are very expensive among the raw materials for the glass industry.

Therefore, when the alkali-free alumina borosilicate-based display cullet containing B ₂ O ₃ is used in the manufacture of the solar cell plate glass as in the present invention, there is no need to store or handle the B ₂ O ₃ feedstock separately. However, since B ₂ O ₃ is already present in the cullet through melting, there is no fear that B ₂ O ₃ will be scattered during the application of cullet as a raw material, and there is no cost to procure B ₂ O ₃ separately. There is an excellent advantage that cannot be generated.

Therefore, the use of cullet raw material as a source of B ₂ O ₃ rather than a separate method of supplying B ₂ O ₃ in manufacturing a solar cell sheet glass would be very advantageous in terms of process and process economy. It is a feature of the present invention.

Meanwhile, in the case of soda-lime silicate-based solar cell glass, the solar light transmittance is controlled to be 90% or more in the range of 400 to 1100 nm in order to increase photoelectric efficiency, and the Fe ₂ O ₃ content incorporated as impurities in the glass for solar cell When higher than 0.02 parts by weight (200 ppm) relative to the total weight of glass lowers the solar transmittance to less than 90%, in the case of solar cell glass, Fe ₂ O ₃ content should be adjusted to 0.02 parts by weight (200 ppm) or less.

Therefore, it would be desirable to minimize the Fe ₂ O ₃ content, but the complexity of the process is caused because the removal of Fe ₂ O ₃ has to undergo a purification process such as grinding and de-ironing. However, the display cullet according to the present invention, since the Fe ₂ O ₃ content is already adjusted in the range of 0.015 parts by weight (150ppm) to 0.02 parts by weight (200ppm) relative to the total weight of the glass, even when manufacturing a glass for solar cells using the same Soda lime silicate-based solar cell glass intrinsic sunlight transmittance will not be reduced.

Therefore, this manner a separate process for impurity purification of the same to the display Cullet to easily obtain a high-quality solar cell glass to lower the content of impurity Fe ₂ O ₃ was used, and the Fe ₂ O ₃ There is a feature of the present invention in that it does not have to go through.

Low iron soda lime silicate-based glass badge composition for solar cells according to a preferred embodiment of the present invention, 32 to 36 parts by weight of feedstock soda ash of Na ₂ O, 100 parts by weight of silica feed or silica of SiO ₂ feed, CaO supply It includes 21 to 22 parts by weight of raw limestone, 5 to 6 parts by weight of feedstock magnesite of MgO, 0.5 to 1.5 parts by weight of clarifier manganese (Na ₂ SO ₄ ), and 3 to 24 parts by weight of alkali-free alumina borosilicate-based display cullet. When the glass prepared by melting the badge composition is analyzed as a chemical component, SiO ₂ 70 to 75 parts by weight, Fe ₂ O ₃ 0.013 to 0.018 parts by weight, Al ₂ O ₃ 0.5 to 2 parts by weight, B ₂ O ₃ 0.1 ˜1.3 parts by weight, 12-14 parts by weight of Na ₂ O and K ₂ O, 10-13 parts by weight of MgO, CaO, SrO, and BaO, and 0.01-1 part by weight of SrO.

Wherein B ₂ O ₃ contains 0.1 to 1.3 parts by weight, when the B ₂ O ₃ is less than the lower limit of 0.1, the effect of improving weather resistance is insignificant, and when the upper limit is 1.3 parts by weight or more, the physical properties of the plate glass changes and quality B ₂ O ₃ has its critical significance in the above range, as it may adversely affect it. Specifically, when the upper limit is 1.3 parts by weight or more, although there is a positive effect of further increasing the corrosion resistance to water, other physical properties related to the production of the glass for solar cells, for example, a large change in the viscosity of the glass, the softening point, and the like. And the coefficient of thermal expansion of the glass itself changes considerably. That is, since it has a big influence on the production process and basic physical properties of the solar cell sheet glass, the amount of B ₂ O ₃ added is limited, and 1.3 parts by weight is the limit value.

Therefore, the limited use of such display cullet containing B ₂ O ₃ has significant advantages in various meanings, such as enhancing the function of the glass for solar cells and simplifying the raw material input process. This is a feature of the invention.

Further, the alkali-free alumina borosilicate display wave glass as used herein is a SiO _2, Al ₂ O _3, alkaline earth because (MgO + CaO + SrO + BaO), and B ₂ O ₃ is the main component feed of SiO ₂ silica sand or silica, the feed of limestone and dolomite, the supply is sufficient to be a material that can be partially or replace all of the raw material, alumina, as well as alkali-free alumina borosilicate display wave glass of Al ₂ O ₃ of CaO is Fe ₂ As a raw material for low iron sheet glass for solar cells requiring a high transmittance of solar rays due to a very low content of O ₃ , its useful value is higher, and according to the conventional method of manufacturing a plate glass depending on the raw material without using the cullet, The purification process required to remove impurities such as Fe ₂ O ₃ from the raw material must be difficult, but according to the present invention, the cullet has a considerably low content of Fe ₂ O ₃ . It is very advantageous for the production of low iron sheet glass for solar cells.

In addition, since most of the raw materials of the badge are crystalline solids, a considerable amount of energy is required during melting into the liquid.Alkali-free alumina borosilicate-based display cullet is already a liquid structured glass, thus replacing crystalline raw materials. Energy savings can be expected by the amount.

Badge melting temperature of the plate glass is 1500 ~ 1550 ℃, the melt is formed into a plate shape in the temperature range corresponding to the viscosity of about 10 ⁴ ~ 10 ^7.6 poise through a clarification process to remove the bubbles. In particular, the liquidus temperature should be lower than the operating temperature corresponding to 10 ⁴ poise to prevent devitrification of local crystals. In addition, each glass has a variety of physicochemical properties that must be provided as a commodity.

Therefore, in order to maximize the effect of the alkali-free alumina borosilicate-based display cullet used as an alternative raw material, the alkali-free alumina boron occupies in the badge composition to maintain or improve the physicochemical properties within the range of maintaining the manufacturing process of the plate glass as much as possible. It is very important to select an appropriate amount of silicate-based display cullet, and the appropriate amount is 100 parts by weight of silica sand, silica or a mixture of silica and silica in the badge composition. The content range of cullet, which is parts by weight and based on these quantitative characteristics, has a critical significance in the above range.

More specifically, when the alkali-free alumina borosilicate-based display cullet is less than 3 parts by weight, the effect as an alternative raw material is insignificant, and the advantage of lowering the manufacturing cost of the glass disappears, and when the amount exceeds 24 parts by weight, a change in the manufacturing process may occur. In addition, the physical and chemical properties of the glass have also changed considerably, thus losing the purpose of the original solar cell glass.

Therefore, in the present invention, various badge compositions in which an alkali-free alumina borosilicate display cullet and other raw materials are mixed in consideration of the composition of low iron soda-lime silicate plate glass are prepared, and the characteristics of the glass prepared after melting are investigated. A badge composition was developed to maintain or improve the manufacturing process and physicochemical properties.

The low iron alkali-free alumina borosilicate-based display cullet used in the present invention is a cullet generated during the manufacturing and processing of the substrate glass for thin film transistor liquid crystal display, and has a composition as shown in Table 1 below. The following composition shows the relative weight to the total weight of the cullet.

ingredient Parts by weight SiO ₂ 58 to 64 Al ₂ O ₃ 15 to 18 B ₂ O ₃ 7 to 11 MgO 0 to 4 CaO 3 to 8 SrO 0.5 to 8 BaO 0 to 3 SnO ₂ 0 to 0.5 ZnO 0 to 0.5 Sb ₂ O ₃ 0 to 0.5 As ₂ O ₃ 0 to 0.8 Fe ₂ O ₃ 0.015-0.02

On the other hand, the role and advantages of each of the main components replaced by the application of low iron alkali-free alumina borosilicate-based display cullet is as follows.

SiO ₂ is an essential oxide involved in glass formation and is a component that stabilizes the network structure of glass. If a part of crystalline silica or silica sand, which is a feedstock of SiO ₂ , is replaced with an alkali-free alumina borosilicate display cullet, the meltability of the badge can be enhanced to reduce the energy input for glass production.

In addition, Al ₂ O ₃ is a component added to suppress devitrification of glass and enhance chemical durability, and part or all of crystalline alumina, which is a feedstock of Al ₂ O ₃ , is replaced with an alkali-free alumina borosilicate-based display cullet. This improves the meltability of the badge, resulting in energy savings and significant cost savings.

In addition, B ₂ O ₃ together with SiO ₂ is an oxide involved in glass formation, which promotes the melting of the badge, reduces the coefficient of thermal expansion of the glass, increases the softening point and enhances chemical durability. When an alkali-free alumina borosilicate-based display cullet is used as a raw material of the plate glass, it is accompanied by some B ₂ O ₃ component, so as to contribute to the improvement of chemical durability and thus weather resistance of the glass as described above.

In addition, MgO, CaO, SrO and BaO has the effect of lowering the viscosity of the glass at high temperatures and increasing the viscosity of the glass at low temperatures while promoting the melting of the badge. If some of the crystalline feedstocks of MgO and CaO containing Fe ₂ O ₃ as impurities are replaced by alkali-free alumina borosilicate-based display cullets, the melting of the badges and the solar transmittance of the glass products can be enhanced and accompanied. In addition, SrO and BaO added are extremely small, and have little effect on the glass properties.

The badge composition according to the present invention includes an alkali-free alumina borosilicate-based display cullet that supplies the above components to maintain or improve the overall characteristics of the solar panel glass. In this case, the general characteristics are that the clarification temperature corresponding to 100 poise related to the production of plate glass is 1450 ℃ or less, the working temperature corresponding to 10,000 poise is 1030 ℃ or less, liquid temperature is 1010 ℃ or less, working temperature and liquid phase The difference between the temperatures is 25 ℃ or higher, the viscosity value in the liquidus temperature is 15000 poise or more, and in the wavelength range of 400 ~ 1100nm in terms of glass products, the solar transmittance of 90% or more based on 4mm thickness and the coefficient of thermal expansion 91 × 10 ^-7 Below / ° C, alkali dissolution, a measure of chemical durability to water, means less than 0.25 mg / g.

[Example]

Based on the badge composition ratio of the following [Table 2] to prepare a badge composition by mixing each raw material so that the weight of the total badge is 500g, using a 700cc platinum crucible was melted for 3 hours at 1550 ℃ using a platinum stirrer The molten glass was homogenized and then molded into a plate shape. The glass was completely cooled by maintaining the temperature at 550 ° C. for 2 hours and lowering the temperature to 350 ° C. by 5 ° C. per minute.

For each badge, high temperature viscosity, liquidus temperature, softening point, thermal expansion, alkali dissolution rate and visible light transmittance were measured for each of the prepared glass, and the results are shown in the bottom of [Table 2]. In [Table 2], the badge meltability (℃) means the temperature at which the crystal phase disappears after maintaining each badge for 4 hours in the temperature range of 900 ~ 1300 ℃, T _m means a temperature corresponding to 100 poise, T _w means the temperature corresponding to 10,000 poise at which molding starts. In addition, T _liq means the liquidus temperature at which devitrification occurs, and the viscosity value (at T _liq ) at the liquidus temperature was calculated using logη = A + B / (TT _o ), which is a temperature-dependent expression of viscosity. Where η is the viscosity, A, B and T _o are constants and T is the temperature (° C.). ΔT is the difference between the molding temperature and the liquidus temperature (T _w -T _liq ), α is the coefficient of thermal expansion between 25 ~ 500 ℃, T _vis means the solar transmittance of the reference 4mm thickness in the 400 ~ 1100nm range.

Raw materials and properties Example Comparative Example Parts by weight One 2 3 4 One 2 Quartz sand 100 100 100 100 100 100 Soda ash 33.2 34.1 35.1 35.8 33.0 34 Limestone 21.8 21.8 21.8 21.8 21.8 22.1 Magnesite 5.4 5.5 5.5 5.6 5.3 5.5 Alumina 0 0 0 0 0.5 0.3 sulphate of soda 0.9 0.9 0.9 0.9 0.8 0.9 Alkali Alumina Borosilicate Display Display Glass 4.2 8.7 13.4 16.7 0 0 characteristic Badge Melt (℃) 1100 1070 1050 1030 1100 1100 T _m (℃) 1435 1433 1435 1438 1435 1437 T _w (℃) 1019 1018 1020 1020 1019 1021 T _liq (℃) 985 986 982 978 988 984 η at T _liq (Poise) 19764 18960 17485 16982 19952 20045 △ T (℃) 34 32 38 42 31 37 Softening point (℃) 721 722 722 724 720 722 α (x10 ^-7 / ° C) 90.0 89.3 88.4 86.6 89.3 89.5 Alkaline Dissolution Rate (mg / g) 0.20 0.20 0.17 0.13 0.23 0.23 T _vis (%) 91.1 91.1 91.2 91.3 90.7 90.5

Comparative Example [Table 2] shows a commercial badge composition of low iron plate glass, Examples 1 to 4 containing 4.2 to 16.7 parts by weight of an alkali-free alumina borosilicate-based display cullet with respect to 100 parts by weight of SiO ₂ It is a badge composition. According to the embodiment, as the weight part of the alkali-free alumina borosilicate display cullet increases, the weight part of the soda ash, limestone and magnesite changes by a very small amount, but the alumina becomes an economical badge composition which is not necessary at all.

Regarding the characteristic part of Table 2, the characteristics of the glass corresponding to each of these badge compositions will be described with reference to Examples and Comparative Examples.

1. In the case of Example, since the temperature at which the crystal phase disappears completely from the badge (a measure of badge melting) is up to 70 ° C. lower than that of the comparative example, the badge meltability is improved as the weight part of the alkali-free alumina borosilicate-based display cullet increases. It is shown. That is, it is possible to melt at low temperatures when the cullet is added, there is an economic advantage.

2. In the case of Example, the process for dissolving and clarifying the badge composition is similar because the clarification temperature (T _m ) corresponding to 100 poise and the working temperature (T _w ) corresponding to 10,000 poise are generally similar to the comparative example. No change is necessary.

3. The liquidus temperature (T _liq ) of the Example is up to about 10 ° C. lower than the comparative example, and the difference between the working temperature and the liquidus temperature (△ T) of each composition is 25 ° C. or more and the viscosity value at the liquidus temperature (η at T _liq). ) Is more than 15,000 poise, showing excellent glass forming ability without devitrification.

4. The softening point of the examples only varies within the range of 4 ° C., and the coefficient of thermal expansion (α) tends to decrease slightly, so that the thermal shock resistance of the glass will be enhanced.

5. The alkali solubility of the examples, which is a measure of the chemical durability of glass against water, is significantly reduced than that of the comparative examples by the addition of alkali-free alumina borosilicate-based display cullet containing B ₂ O ₃ , so that the It is expected that the life of the solar cell will be significantly increased due to the improved weather resistance of rain, snow, or moisture in the solar cell glass used.

6. The solar light transmittance (T _vis ) of the embodiment will increase than the comparative example will contribute to the improvement of the photoelectric efficiency of the solar cell. This is related to the content of Fe ₂ O ₃ of the following Table 3, and when using an alkali-free alumina borosilicate-based display cullet as in the embodiment, the Fe ₂ O ₃ of the impurities without additional purification process As a result of the drastic reduction in the amount, the solar light transmittance is higher than that of the comparative example in the case of the examples.

When the components of the glass prepared from the badge composition shown in Examples and Comparative Examples of [Table 2] in parts by weight, that is, the composition is as follows [Table 3]. When comparing the commercial composition prepared using only the purified industrial raw materials shown in the comparative example of Table 3 and the composition of the example using the alkali-free alumina borosilicate display cullet as a raw material, the embodiment according to the present invention Al ₂ O ₃ is slightly increased, and Fe ₂ O ₃ is significantly reduced to less than 0.015 parts by weight as the weight part of the cullet increases in the example compared to 0.02 parts by weight of the comparative example incorporated from the purified industrial raw material, B _{Although 2} O ₃ , SrO, and SnO ₂ components appear additionally, as shown in the properties of [Table 2], it is understood that the original glass properties are not deteriorated as well as the original glass properties are at least maintained or further improved, as shown in the properties of [Table 2]. Can be .

Example Comparative example ingredient One 2 3 4 One 2 Furtherance
(Parts by weight) SiO ₂
Al ₂ O ₃
B ₂ O ₃ 72.5
0.57
0.3 72.1
1.0
0.6 71.3
1.5
0.9 71.0
1.9
1.1 72.8
0.4
0 72.6
0.18
0 Na ₂ O
K ₂ O 13.9
0.1 13.8
0.1 13.7
0.1 13.6
0.1 14
0.1 14
0.1 MgO
CaO
SrO 3.9
8.6
0.02 3.8
8.5
0.04 3.8
8.5
0.07 3.8
8.4
0.08 3.9
8.7
0 3.6
9.5
0 Fe ₂ O ₃
SnO ₂ 0.018
0.01 0.0169
0.02 0.0153
0.03 0.0142
0.04 0.018
0 0.02
0

While specific embodiments of the present invention have been described as described above, it is obvious that the present invention may be modified and practiced by those skilled in the art. Such modified embodiments should not be individually understood from the technical spirit or viewpoint of the present invention, and these modified embodiments should be included within the claims of the present invention.

Claims (4)

In the low iron soda lime silicate-based glass sheet composition for solar cells,
When 100 parts by weight of silica sand, silica or a mixture of silica and silica in the badge composition, 32 to 36 parts by weight of soda ash, 0.5 to 1.5 parts by weight of manganese, 3 to 24 parts by weight of alkali-free alumina borosilicate-based display cullet, limestone A low iron soda lime silicate-based plate glass badge composition for solar cells, which is made of an alkali-free alumina borosilicate-based display cullet, which is selected from magnesite and dolomite. The method of claim 1,
When the silica sand, silica or a mixture of silica and silica is 100 parts by weight, the limestone is 21 to 22 parts by weight, the magnesite is 5 to 6 parts by weight of low iron soda lime silicate-based glass sheet composition for solar cells . The method of claim 1,
When the silica sand, silica or a mixture of silica and silica to 100 parts by weight, the limestone is 7 to 9 parts by weight, the dolomite is low iron soda lime silicate-based plate glass composition for solar cells, characterized in that it contains 23 to 27 parts by weight . The method of claim 2 or 3,
The plate glass manufactured by melting the low iron soda lime silicate-based plate glass composition for solar cells, when the plate glass is 100 parts by weight, SiO ₂ 70 to 75 parts by weight, Fe ₂ O ₃ 0.013 to 0.018 parts by weight, Al ₂ O ₃ 0.5 to 2 parts by weight, B ₂ O ₃ 0.1 to 1.3 parts by weight, Na ₂ O and K ₂ O 12 to 14 parts by weight, MgO, CaO, SrO, and BaO 10 to 13 parts by weight, SrO 0.01 to 1 parts by weight Low iron soda lime silicate plate glass badge composition for a solar cell.