TW201434781A - Touch cover glass composition - Google Patents

Abstract

A touch cover glass composition has the following composition based on weight percentage: 64% to 69% of silicon oxide (SiO2), 7% to 15.5% of aluminum oxide (Al2O3), 1.5% to 2.5% of boron oxide (B2O3), 4.5% to 7.5% of magnesium oxide (MgO), greater than 0% to 2.5% of calcium oxide (CaO), greater than 0% to 2% of zinc oxide (ZnO), greater than 0% to 0.2% of zirconium oxide (ZrO2), greater than 0% to 1% of titanium oxide (TiO2), 14.5% to 16.5% of sodium oxide (Na2O), 1% to 4% of potassium oxide (K2O), and greater than 0% to 0.4% of tin oxide (SnO2), wherein the total amount of calcium oxide and magnesium oxide preferably ranges between 4.5% and 10%, the total amount of sodium oxide and potassium oxide preferably ranges between 15.5% and 20.5%. Thus, the composition material can be molten to form a touch cover glass and immersed in a high temperature potassium nitrate solution to replace sodium ions (smaller size) at a certain depth on the surface layer of the touch cover glass for potassium ions (larger size) by ion exchange, so as to form squeezing effect on the surface layer to form a touch cover glass with high strength, wear resistance, and scratch resistance.

Description

Touch protection glass composition

The invention relates to a high-strength, abrasion-resistant and scratch-resistant touch glass, which does not contain environmentally harmful components such as lead oxide, arsenic oxide or antimony oxide, and is produced and manufactured. Safe to use in the process without harming the environment.

A touch protection glass (or cover glass) generally used on touch screens and liquid crystal displays of mobile electronic devices (such as mobile phones, tablets or notebook computers) is an aluminosilicate glass. The ion exchange treatment process is formed by strengthening. The glass composition contains only a very small amount of an alkali metal oxide component, and can be formed into a glass by a molding method such as a float method or a down-draw method.

Arsenic oxide (As ₂ O ₃ ) and bismuth oxide (Sb ₂ O ₃ ) in the conventional glass composition may cause harm to the human body and the environment, for example, the glass component disclosed in the Patent Publication No. I252844 of the Republic of China, which contains Harmful arsenic oxide and antimony oxide in the human body; however, if the arsenic oxide and antimony oxide in the glass are replaced by different components, the original optical and physical properties of the glass must be changed, so the composition of the glass and its weight percentage must be extensive. R & D and changes in order to overcome the above problems.

In the molding process, when the molten glass temperature is lowered, It is easy to cause the glass to crystallize and devitrify (that is, lose transparency due to precipitation of crystals), and define the maximum temperature at which the glass begins to devitrify or crystallize, that is, the liquid liquid temperature (LT, Liquidus Temperature), in order to avoid Devitrification, which affects the appearance quality of glass, the lower the liquidus temperature (LT) requirement of glass, the better. Therefore, when the working temperature is higher than the liquid phase temperature of the glass, even after long-time heat treatment, devitrification will not occur. Or crystallization, on the contrary, it is easy to cause crystal devitrification, resulting in impurities on the surface or inside of the glass, which will change the stress distribution inside the glass, reduce the hardness and strength of the glass, and lead to a decline in product yield. For example, the Republic of China The glass disclosed in the publication No. I305768 has a glass stability of less than 1000 ° C because of its liquidus temperature.

In addition, the melting temperature of the raw materials in the molding process is also required to be as low as possible to reduce energy consumption and increase furnace life. In the glass disclosed in the Patent No. 200637800 of the Republic of China, the composition thereof must be at a high temperature of 1600 ° C or higher to be melted, so that the energy consumption is high, which is disadvantageous for reducing the production cost.

It can be seen from the above that the improvement direction of the present invention is how to design an innovative touch protection glass composition, which can replace environmentally harmful components such as arsenic oxide or antimony oxide by adding and changing the composition ratio. Furthermore, a touch protection glass with devitrification resistance is produced to solve the problem that the conventional glass does not comply with environmental protection standards, causing harmful gas emission of the glass during the melting process, and the finished glass product contains harmful substances.

In view of the above needs, the present inventors have conducted research and analysis on glass compositions based on years of experience in related industries and experimental design, and can design a better touch protection glass; thus, the main features of the present invention The purpose is to replace the environmentally harmful components such as lead oxide, arsenic oxide or antimony oxide by adding and changing the proportion of the composition, thereby producing a touch protection glass with devitrification resistance to solve the problem of melting the conventional glass. Harmful gas emissions are generated during the process, and the finished glass product contains harmful substances.

In order to achieve the above object, the present invention mainly strengthens the structure by adding and changing the weight percentage of the constituents in the glass composition, thereby producing a touch protection glass having devitrification resistance, and the touch protection The composition of the glass is 64% to 69% by weight of cerium oxide (SiO ₂ ), 7% to 11.5% of aluminum oxide (Al ₂ O ₃ ), and 1.5% to 2.5% of boron oxide (B ₂ O _{3 ).} ), 4.5% to 7.5% magnesium oxide (MgO), greater than 0% to 2.5% calcium oxide (CaO), greater than 0% to 2% zinc oxide (ZnO), greater than 0% to 0.2% zirconia ( ZrO ₂ ), greater than 0% to 1% of titanium oxide (TiO ₂ ), 14.5% to 16.5% of sodium oxide (Na ₂ O), 1% to 4% of potassium oxide (K ₂ O), and greater than 0% to 0.4% tin oxide (SnO ₂ ), wherein the total content of calcium oxide and magnesium oxide is preferably between 4.5% and 10%, and the total content of sodium oxide and potassium oxide is between 15.5% and 20.5%. Preferably, the composition material is melted to form a touch protection glass having better devitrification resistance, and a network structure can be formed in the glass by using cerium oxide, and the glass is used to form a tough surface by using aluminum oxide. Increase the glass Glass heat resistance and resistance to devitrification, reduce glass expansion rate, and reduce the viscosity and expansion coefficient of glass by using boron oxide, magnesium oxide and calcium oxide, and increase the corrosion resistance and meltability of glass by zinc oxide, and by oxidation Zirconium increases the chemical resistance, heat resistance and meltability of the glass, and lowers the melting temperature of the glass raw material by titanium oxide, while the glass is easily formed by sodium oxide, and the glass viscosity is increased by the potassium oxide, so that the glass is hard. It is lustrous and replaces components such as lead oxide, arsenic oxide or antimony oxide with tin oxide as a clarifying agent or defoaming agent for glass melting. Thus, it can solve the problem that the conventional glass contains arsenic oxide or antimony oxide. Harmful ingredients, so that harmful gas emissions are generated during the melting process, and the finished glass contains the problem of harmful substances.

In order for your review board to have a clear understanding of the structure, composition and efficacy of the present invention, please refer to the following table for a description. Please refer to it.

The present invention mainly provides a touch protection glass composition, the touch protection glass is composed of the following materials, according to a certain percentage by weight: (1) 64% to 69% by weight of cerium oxide (SiO ₂ ); (2) 7% to 11.5% by weight of alumina (Al ₂ O ₃ ); (3) 1.5% to 2.5% by weight of boron oxide (B ₂ O ₃ ); (4) 4.5% to 7.5% by weight Magnesium oxide (MgO); (5) more than 0% to 2.5% by weight of calcium oxide (CaO); (6) more than 0% to 2% by weight of zinc oxide (ZnO); (7) by weight greater than 0 3% to 0.2% zirconia (ZrO2); (8) weight percent greater than 0% to 1% titanium oxide (TiO2); (9) weight percent 14.5% to 16.5% sodium oxide (Na2O); (10) weight a percentage of 1% to 4% potassium oxide (K2O); (11) a weight percentage greater than 0% to 0.4% tin oxide (SnO ₂ ); and (12) a total weight percentage of calcium oxide and magnesium oxide, Between 4.5% and 10%, and the total weight percentage of sodium oxide and potassium oxide is between 15.5% and 20.5%.

In the present invention, since the weight percentage of each component component will have different degrees of influence on the characteristics, structure and production of the glass depending on its physical properties, each component component must have a limitation on the weight percentage, The reason for selecting the components of the touch protection glass and the weight percentage thereof are limited to a certain range: cerium oxide (SiO ₂ ) is the main component forming the structure of the glass network, which improves chemical durability, increases viscosity and reduces The liquidus temperature has a good effect, and the preferred weight percentage is 64% to 69%. If the cerium oxide (SiO ₂ ) content is less than 64%, the produced glass will be easily devitrified, on the other hand, if If the content of cerium oxide is more than 69%, the melting temperature of the glass will be too high, and the glass produced will be easily devitrified.

Alumina (Al ₂ O ₃ ) is used to increase the strength of the glass structure, to make the glass a tough surface, thereby increasing the heat resistance and devitrification resistance of the glass, reducing the glass expansion rate, improving the chemical durability and increasing the viscosity. Good results, the preferred weight percentage is between 7% and 11.5%. If the content of alumina (Al ₂ O ₃ ) is less than 7%, the glass will be easily devitrified and easily exposed to external moisture or chemical reagents. The erosion, if the content of alumina (Al ₂ O ₃ ) is more than 11.5%, will also cause the melting temperature of the glass to be too high, which is unfavorable for manufacturing in a general melting furnace.

Boron oxide (B ₂ O ₃ ) acts as a fluxing agent, mainly used to reduce the viscosity of glass when melting glass, and has a good effect on homogenization of glass and lowering of melting temperature. The preferred weight percentage is 1.5% to 2.5%, if the boron oxide content is less than 1.5%, the flux effect can not be fully exerted, and the glass is easily devitrified. If the boron oxide content is more than 2.5%, the strain point of the glass will be greatly reduced, which is not conducive to Application of subsequent processes.

Magnesium oxide (MgO) is used to reduce the viscosity and expansion coefficient of glass when melting glass, to reduce the content of bubbles or impurities therein, and to lower the liquidus temperature and increase the resistance to devitrification, which is an effective component for adjusting the optical constant. The preferred percentage by weight is between 4.5% and 7.5%. However, if the content of magnesium oxide (MgO) is more than 7.5%, the glass will be easily devitrified and the chemical durability will be deteriorated.

The role of calcium oxide (CaO) is to promote the melting of glass, to lower the temperature of the liquid phase of the glass and to improve its resistance to devitrification. The preferred weight percentage is between more than 0% and 2.5%, if the calcium oxide content is 0%. The viscosity and liquidus temperature of the glass will not be effectively reduced. If the calcium oxide content is more than 2.5%, the devitrification resistance and chemical durability of the glass will be deteriorated, and the thermal expansion coefficient will be greatly improved, which is not conducive to the application of subsequent processes. .

Zinc oxide (ZnO) can increase the corrosion resistance and meltability of glass, has the effect of improving chemical durability and lowering the liquidus temperature. The preferred weight percentage is between more than 0% and 2%, if zinc oxide When the content is 0%, the above effect becomes inconspicuous, and if the zinc oxide content is more than 2%, the devitrification resistance of the glass is deteriorated.

Zirconium oxide (ZrO2) can increase chemical resistance, heat resistance and meltability, and has an effect of increasing resistance to devitrification and chemical durability. The preferred weight percentage is between more than 0% and 0.2%, if oxidized. If the zirconium content is 0%, the above effect will become inconspicuous. If the zirconia content is more than 0.2%, the devitrification resistance of the glass will be deteriorated, which is disadvantageous for the application of the product; titanium oxide (TiO ₂ ) can reduce the glass raw material. The melting temperature, preferably in a weight percent range, is between greater than 0% and 1%.

The touch protection glass formed by the composition of the present invention must be further immersed in a high temperature potassium nitrate solution, and the sodium ion (small volume) of the touch protection glass surface layer is replaced with potassium ions by chemical strengthening. Large), thereby forming a high-strength, abrasion-resistant and scratch-resistant touch protection glass, so the touch protection glass must contain a certain amount of sodium ions, so sodium oxide (Na is added to the composition of the present invention) ₂ O), in order to provide a sufficient amount of sodium ions; in addition, sodium oxide (Na ₂ O) can lower the glass melting temperature and liquidus temperature, making the glass easy to shape, preferably in a weight percentage of 14.5% to 16.5% If the content of sodium oxide is more than 16.5%, the devitrification resistance of the glass may be deteriorated; potassium oxide (K ₂ O) may lower the melting temperature and the liquidus temperature, and the preferred weight percentage is 1% to 4%. If the potassium oxide content is more than 4%, the glass will be easily devitrified.

The role of tin oxide (SnO ₂ ) is mainly to replace the components such as lead oxide, arsenic oxide or antimony oxide. As a clarifying agent or defoaming agent for glass melting, the preferred weight percentage is between more than 0% and 0.4%. If the tin oxide content is 0%, the above effect will become inconspicuous. If the tin oxide content is more than 0.4%, not only the devitrification resistance of the glass will be deteriorated, but also the application of the product is unfavorable, and it is easy to be in the process of cooling the glass. Condensed in the upper part of the platinum system and dropped back into the glass, causing the enthalpy to occur and reducing the yield.

In particular, the above-mentioned components such as calcium oxide and magnesium oxide are used to promote the melting degree of the glass and to adjust the thermal expansion coefficient of the glass, but the total weight percentage of calcium oxide and magnesium oxide is 4.5%. Between 10% is the best, if the total content of calcium oxide and magnesium oxide is less than 4.5%, the melting temperature of the glass will be too high, and vice versa, if calcium oxide And the total content of magnesium oxide is more than 10%, the glass will be easily devitrified, and the coefficient of thermal expansion of the glass will be too high; in addition, the total weight percentage of sodium oxide and potassium oxide is between 15.5% and 20.5%. Preferably, if the total content of sodium oxide and potassium oxide is less than 15.5%, the melting temperature and liquidus temperature of the glass will be too high, and if the total content of components such as sodium oxide and potassium oxide is more than 20.5%, the glass is Devitrification resistance will deteriorate.

In the implementation of the present invention, the composition is uniformly mixed, and then the mixed raw material is introduced into a glass melting tank, and the mixed raw material is melted into a glass liquid, and then the temperature is lowered to a temperature range required for molding, and then the following A glass plate having a predetermined thickness is produced by a draw molding method.

In the following, the above-mentioned respective compositions of the present invention are mixed in different weight percentages, and different glass samples are prepared according to the above procedures, and the glass samples are taken as an example to list the thermal expansion coefficient, strain point and density. And the difference between the characteristic values of the glass liquid temperature:

The composition and characteristics of the glass sample produced by the present invention are shown in Table 1 (Example 1), that is, the examples of the present invention. The glass samples in Table 1 were prepared by the following methods; each component was taken as a common raw material, uniformly mixed according to the corresponding weight percentage, and then melted in a furnace at a temperature of 1650 ° C, and then uniformly stirred in a platinum heating system. Then, the molten glass is cooled and formed into a sheet shape by a pull molding method. At this time, for the glass sample to be tested, characteristic values such as thermal expansion coefficient, strain point, density, and glass liquid phase temperature can be obtained, respectively, and listed in the corresponding fields in Table 1.

The invention detects the respective characteristic values of each glass sample mainly by the following methods:

(1) Detection of thermal expansion coefficient (unit: 10 ^-7 /°C): heating and measuring the elongation of the glass sample by a mechanical pusher type thermal expansion meter, the temperature range is from room temperature to the glass is no longer elongated, or even due to softening The temperature until the contraction.

(2) Detection of strain point (unit: °C): Heating and measuring the relationship between the deformation rate of the glass sample and the temperature, and the temperature corresponding to the specific deformation rate is taken as the strain point.

(3) Detection of density (unit: g/cm3): A bulk glass containing no bubbles of about 2 g was taken, and the density of the glass sample was measured by floating in a specific gravity liquid.

(4) Detection of glass liquidus temperature (unit: °C): Put glass cullet less than 850μm into a white gold dish, place it in a gradient furnace for 24 hours, measure the crystal crystallization of the glass with a microscope, and determine the liquidus temperature. .

From the respective test data in Example 1 (ie, the present invention) shown in Table 1, it can be clearly observed that the touch protection glass made according to the composition of the present invention has a thermal expansion coefficient of less than 73.2 (10 ^-7 /°C). ), and its strain point is higher than 565 ° C, the density is less than 2.40 g / cm ³ and other characteristic values, and is very similar to the substrate glass for general liquid crystal displays, so it is suitable as a material for a glass substrate for general liquid crystal displays.

In summary, the present invention mainly forms a network structure in the glass by yttrium oxide, and forms a tough surface by using alumina, thereby increasing the heat resistance and devitrification resistance of the glass, reducing the glass expansion rate, and borrowing Boron oxide, magnesium oxide and calcium oxide reduce the viscosity and expansion coefficient of the glass, while increasing the corrosion resistance and meltability of the glass by zinc oxide, and increasing the chemical resistance, heat resistance and melting property of the glass by zirconia, and borrowing The melting temperature of the glass raw material is lowered by titanium oxide, and the glass is easily formed by sodium oxide, and the viscosity of the glass can be increased by using potassium oxide. The glass is hard and shiny, and the components such as lead oxide, arsenic oxide or cerium oxide are replaced by tin oxide, and are used as a clarifying agent or a defoaming agent in the melting of the glass, thereby reinforcing by adding and changing the composition ratio. Structure, after the invention is implemented, it can indeed achieve the purpose of providing a touch protection glass which has devitrification resistance and does not contain harmful components such as lead oxide, arsenic oxide or antimony oxide, so that the above-mentioned constituent materials can be obtained. The touch protection glass formed after melting is immersed in a high temperature potassium nitrate solution, and the sodium ion (small volume) of the touch protection glass surface layer is replaced with potassium ions (large volume) by chemical strengthening. A high-strength, abrasion-resistant and scratch-resistant touch protection glass is formed.

The above is only the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any change and modification made by those skilled in the art without departing from the spirit and scope of the invention. All should be covered by the patent of the present invention.

In summary, the effect of the present invention is in accordance with the "practicality", "novelty" and "progressiveness" of the patent application requirements; the applicant filed an application for an invention patent to the shackle in accordance with the provisions of the Patent Law.

Claims (3)

A touch protection glass composition comprising: 64% to 69% by weight of cerium oxide; 7% to 11.5% by weight of alumina; 1.5% to 2.5% by weight of boron oxide; and 4.5 by weight % to 7.5% of magnesium oxide; weight percent greater than 0% to 2.5% calcium oxide; weight percent greater than 0% to 2% zinc oxide; weight percent greater than 0% to 0.2% zirconia; weight percent More than 0% to 1% titanium oxide; 14.5% to 16.5% by weight of sodium oxide; 1% to 4% by weight of potassium oxide; and more than 0% to 0.4% by weight of tin oxide. The composition of the touch protection glass according to claim 1, wherein the total weight percentage of the calcium oxide and the magnesium oxide is between 4.5% and 10%. The composition of the touch protection glass according to claim 1, wherein the total weight percentage of the sodium oxide and the potassium oxide is between 15.5% and 20.5%.