KR20130127957A - Alkali glass and method for manufacturing the same - Google Patents

Abstract

The present invention relates to alkali glass having lightweight, excellent molding ability, and suitability for chemical strengthening, and a method for manufacturing the same. The glass by one case of the present invention is the alkali glass which contains 62-75% of SiO2, 10.5-15% of Al2O3, 15.5-18% or Na2O, 3.1-7% of K2O, 0.5-2% of MgO, 0-2% of CaO, and 1.5-4% of ZrO2 by weight based on oxides. [Reference numerals] (S110) Mix glass raw materials;(S120) Melting;(S130) Forming;(S140) Slowly Cooling

Description

Alkali glass and method for manufacturing the same

TECHNICAL FIELD The present invention relates to glass manufacturing techniques, and more particularly, to an alkali glass composition and a method for producing such glass.

Glass, especially flat glass, is used in various fields such as window glass, window screens of vehicles, mirrors, and the like, and its type is also being developed and used in various ways.

Glass may require a variety of different properties depending on the device, device, location, etc. to which the glass is applied. Among these, the mechanical strength of glass is mentioned as a characteristic currently considered important. Since glass has the property of being fragile in nature, the improvement of the mechanical strength of glass can be said to be a very important factor in increasing the utility of glass.

Moreover, in recent years, display devices such as mobile phones such as smart phones, portable computers, digital cameras, PDAs, and the like are widely used, and glass can also be used in such display devices. In particular, many touch panels are applied to such display devices, and cover glass is commonly used in display devices to which the touch panels are applied.

Cover glass is also called protective glass and high mechanical strength is calculated | required by the application characteristic. Therefore, the tempered glass substrate which improved the mechanical strength of a glass substrate is mainly used for this display apparatus as a cover glass. The tempered glass substrate may be manufactured in various ways, but a commonly used method is a method of chemically strengthening the glass substrate. This chemical strengthening scheme is generally performed by chemically treating a glass substrate, such as immersing the glass substrate in a solution such as potassium nitrate to cause ion exchange in the glass substrate.

As such, in order to manufacture chemically strengthened glass, the glass substrate is chemically treated, and in this process, the mechanical strength of the glass substrate is improved through ion exchange. Therefore, in order to produce chemically strengthened glass, there is a need for glass having a suitable composition suitable for chemically strengthening treatments, such as to ensure good ion exchange performance.

In addition to the suitability for chemical strengthening, the glass also needs to have various other properties as appropriate.

For example, in the case of glass used for display devices such as smartphones, PDAs, and TVs, weight reduction should be ensured. In particular, in recent years, as display devices such as TVs and monitors are gradually enlarged, the area of glass used therein is also increasing. In this case, since the warping phenomenon of the glass due to the load of the glass itself can be further increased, in order to prevent this, the glass needs to be made lighter. In addition, when such glass is used in a small portable display device such as a mobile phone, a PDP or a notebook, it will be required to reduce the weight of the glass in order to increase portability.

In addition, the glass must ensure proper processability and formability. Otherwise, the processing or shaping of the glass is not easy to produce a glass product suitable for the desired shape and quality, and the energy and time required for processing or forming may be increased, thereby reducing the productivity of the glass product.

Accordingly, the present invention has been made to solve the above problems, and an object thereof is to provide an alkali glass and a method for producing the same, which are light, have good workability and moldability, and are suitable for chemically strengthening treatment.

Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. It will also be readily apparent that the objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

In order to achieve the above object, the present inventors invented a glass composition suitable for chemical strengthening while having desirable physical properties after repeated studies on alkali glass.

Glass according to an aspect of the present invention, as the alkali glass, in terms of oxide basis weight% display, SiO ₂ 62-75%; Al ₂ O ₃ 10.5-15%; Na ₂ O 15.5-18%; K ₂ O 3.1-7%; MgO 0.5-2%; CaO 0-2%; And ZrO ₂ 1.5-4%.

Preferably, the alkali glass is an oxide basis weight% display, SiO ₂ 63-73%; Al ₂ O ₃ 10.5 to 14%; Na ₂ O 15.5-17%; And K ₂ O 3.1 to 5%.

Also preferably, the alkali glass has a density of 2.50 g / cm ³ or less.

Also preferably, the alkali glass has a coefficient of thermal expansion of 9.0 × 10 ⁻⁶ / ° C. to 11.0 × 10 ⁻⁶ / ° C.

Also preferably, the alkali glass has a temperature of 1200 ° C. or lower at a viscosity of 10 ⁴ dPas.

Also preferably, the alkali glass has a strain point of 500 ° C or lower.

Also preferably, the alkali glass has a slow cooling point of 540 ° C or lower.

Further, the tempered glass according to another aspect of the present invention for achieving the above object is a glass chemically strengthened the above-mentioned alkali glass.

Preferably, the tempered glass has a surface compressive stress greater than 200 MPa.

Also preferably, the tempered glass has a thickness of the compressive stress layer greater than 10 μm.

More preferably, the tempered glass has a surface compressive stress of more than 400 MPa.

Also preferably, the tempered glass has a thickness of the compressive stress layer greater than 20 μm.

In addition, the display device according to another aspect of the present invention for achieving the above object includes the above-mentioned alkali glass.

In addition, the glass manufacturing method according to an aspect of the present invention for achieving the above object, as a method for producing an alkali glass, in terms of oxide basis weight% display, 62 to 75% SiO ₂ ; Al ₂ O ₃ 10.5-15%; Na ₂ O 15.5-18%; K ₂ O 3.1-7%; MgO 0.5-2%; CaO 0-2%; And combining the glass raw materials to contain 1.5-4% of ZrO ₂ .

Preferably, the glass raw material combination step, based on the oxide weight% display, SiO ₂ 63 ~ 73%; Al ₂ O ₃ 10.5 to 14%; Na ₂ O 15.5-17%; And glass raw materials to contain 3.1-5% of K ₂ O.

Also preferably, the density of the glass produced is 2.50 g / cm ³ or less.

Also preferably, the coefficient of thermal expansion of the produced glass is 9.0 × 10 ⁻⁶ / ° C. to 11.0 × 10 ⁻⁶ / ° C.

Also preferably, the temperature at viscosity 10 ⁴ dPas of the produced glass is 1200 ° C. or less.

Also preferably, the strain point of the produced glass is 500 ° C. or less.

Also preferably, the slow cooling point of the produced glass is 540 ° C or lower.

In addition, the tempered glass manufacturing method according to another aspect of the present invention for achieving the above object includes the step of chemically strengthening the glass produced by the above-described alkali glass manufacturing method.

Preferably, the surface compressive stress of the produced tempered glass is greater than 200 MPa.

Also preferably, the compressive stress layer thickness of the prepared tempered glass is greater than 10 um.

More preferably, the surface compressive stress of the prepared tempered glass is greater than 400 MPa.

Also preferably, the compressive stress layer thickness of the prepared tempered glass is more than 20 um.

According to the present invention, an alkali glass suitable for improving the strength in a chemically strengthening manner can be provided. In particular, according to one aspect of the present invention, an alkali aluminosilicate glass suitable for chemical strengthening is provided.

Moreover, according to this invention, when manufacturing tempered glass by a chemical strengthening process, surface compressive stress can be raised and a compressive stress layer thickness can be made thick.

Therefore, in the case of the glass according to the present invention, it can be usefully used for a cover glass of a display device and the like requiring high mechanical strength.

In addition, according to another aspect of the present invention, a low density glass may be provided. Therefore, even a glass plate with a large area can reduce the warping phenomenon due to its own weight, and can meet the trend of increasing the size of display devices such as TVs and monitors. In addition, even in the case of a small portable device such as a mobile phone or a notebook using a glass plate can be reduced in weight, the portability can be improved.

In addition, according to another aspect of the present invention, a glass having a coefficient of thermal expansion of 9.0 × 10 ⁻⁶ / ° C. to 11.0 × 10 ⁻⁶ / ° C. may be provided. Thus, it is suitable for use with materials having a coefficient of thermal expansion in a similar range.

In addition, according to another aspect of the present invention, T _{4, which} is a temperature at a viscosity of 10 ⁴ dPas, is low, thereby lowering the processing temperature of the glass, thereby facilitating the processing of the glass. Therefore, since energy or time required for processing the glass can be reduced, productivity of the glass and the product using the same can be improved.

In addition, according to another aspect of the present invention, a glass having a low distortion point and a slow cooling point may be provided. Thus, the moldability of the glass can be improved, and in particular, 3D molding of the glass can be facilitated. Therefore, according to this aspect, it is easy to manufacture the glass in a desired form including a three-dimensional form, and the applicability of the glass can be improved.

The following drawings, which are attached to this specification, illustrate exemplary embodiments of the present invention, and together with the detailed description of the present invention, serve to further understand the technical spirit of the present invention. It should not be construed as limited to.
1 is a flowchart schematically showing a method for producing aluminosilicate glass according to an embodiment of the present invention.
FIG. 2 is a graph showing a comparison between compressive stress and compressive stress layer thickness measurement results formed during chemically strengthening treatment of the glass of Examples and Comparative Examples of the present invention. FIG.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention.

Therefore, the embodiments described herein are only the most preferred embodiments of the present invention and do not represent all of the technical idea of the present invention, and various equivalents and modifications that may substitute them at the time of the present application may be used. It should be understood that there may be.

The glass according to the present invention is an alkali glass containing an alkali metal oxide, and may be referred to as an alkali aluminosilicate glass by containing aluminum oxide and silicon dioxide together with such an alkali metal oxide.

More specifically, the alkali glass according to the present invention may include SiO ₂ , Al ₂ O ₃ , Na ₂ O, K ₂ O, MgO, CaO, and ZrO ₂ as composition components.

In particular, the alkali glass according to the present invention may contain 62 to 75% of SiO ₂ in terms of oxide basis weight%. SiO ₂ is a network structure oxide that forms glass, which may contribute to increasing the chemical resistance of the glass and having an adequate coefficient of thermal expansion that can be matched with the glass's surrounding materials. However, when SiO ₂ is contained too high, melting or shaping of the glass becomes difficult, the coefficient of thermal expansion is too low, and the devitrification characteristics of the glass may be deteriorated. On the other hand, when SiO ₂ is contained too low, the chemical resistance may decrease, the density may increase, the coefficient of thermal expansion may increase, and the strain point may decrease. Accordingly, the alkali-free glass according to the present invention include SiO _2, 62 ~ 75% by weight. Preferably, the SiO ₂ is preferably included 63 to 73% by weight. More preferably, the SiO ₂ is preferably included 63 to 70% by weight.

Further, the alkali-free glass according to the invention may contain 10.5 ~ 15% Al ₂ O ₃ as oxides based on weight percentages. Al ₂ O ₃ increases the high temperature viscosity, chemical stability, thermal shock resistance and the like of the glass and may contribute to increase the strain point and Young's modulus. However, when the Al ₂ O ₃ contained is too high, dropping the devitrification property, the hydrochloric acid resistance and the BHF resistance can increase the viscosity. On the other hand, when Al ₂ O ₃ is contained too low, its addition effect is difficult to achieve properly and the elastic modulus may be low. Accordingly, the alkali-free glass according to the present invention include 10.5 to 15% by weight of Al ₂ O _3. Preferably, Al ₂ O ₃ is preferably contained 10.5 to 14% by weight. More preferably, the Al ₂ O ₃ It is preferably included 10.5 ~ 13% by weight.

Further, the alkali-free glass according to the invention may contain 15.5 ~ 18% of Na ₂ O based on an oxide weight percentages. Na ₂ O is a component that is ion-exchanged in a chemical strengthening process in a potassium nitrate (KNO ₃ ) solution, etc., and may contribute to improving the meltability, formability and devitrification resistance of the glass, lowering the high temperature viscosity of the glass, and reducing the incidence of cracking. have. However, when Na ₂ O is contained too high, the coefficient of thermal expansion of the glass becomes too large, so that it is difficult to match with the surrounding materials, and the devitrification resistance and thermal shock resistance may be lowered. On the other hand, when Na ₂ O is contained too low, the effect of addition thereof is difficult to be achieved and the ion exchange performance may be degraded in the chemical strengthening process. Accordingly, the alkali-free glass according to the present invention include 18 ~ 15.5% by weight of Na ₂ O. Preferably, Na ₂ O is preferably contained 15.5 ~ 17% by weight.

Further, the alkali-free glass according to the invention may contain 3.1 ~ 7% of K ₂ O as an oxide basis weight percentages. K ₂ O may contribute to promoting ion exchange in the chemical strengthening process of glass, lowering the high temperature viscosity of the glass to improve meltability and formability and to reduce crack incidence. However, when K ₂ O is contained too high, the coefficient of thermal expansion of the glass is too large, it is difficult to match with the surrounding material, the thermal shock resistance may be lowered, devitrification resistance may be worse. On the other hand, when K ₂ O is contained too low, its addition effect is difficult to be achieved and the ion exchange performance may be degraded in the chemical strengthening treatment process. Accordingly, the alkali-free glass according to the present invention include 3.1 ~ 7% by weight of K ₂ O. Preferably, the K ₂ O is preferably contained 3.1 to 5% by weight.

In addition, the alkali glass which concerns on this invention can contain 0.5-2% of MgO by the oxide basis weight% display. MgO is an alkaline earth metal oxide, which does not excessively increase the coefficient of thermal expansion, does not significantly reduce the strain point, and may contribute to improving meltability. In particular, MgO can reduce the density of the glass, which can greatly contribute to the weight reduction of the glass. However, when MgO is contained too high, the devitrification characteristic of glass may fall, and acid resistance and BHF resistance may fall. On the other hand, when MgO is contained too low, it is difficult to achieve the above-mentioned MgO addition characteristic. Thus, the alkali glass according to the invention comprises 0.5 to 2% by weight of MgO.

In addition, the alkali glass which concerns on this invention can contain CaO 0 to 2% by an oxide reference weight% display. CaO, like MgO, is an alkaline earth metal oxide that can contribute to lowering the density and coefficient of thermal expansion, not significantly reducing the strain point, and improving meltability. However, when CaO is contained too high, the density and the coefficient of thermal expansion can be large and the chemical resistance such as BHF resistance can be degraded. Thus, the alkali glass according to the present invention may comprise less than 2% by weight of CaO.

Further, the alkali-free glass according to the invention may contain 1.5 ~ 4% ZrO ₂ as an oxide based on weight percentages. ZrO ₂ may contribute to promoting ion exchange and improving the Young's modulus of the glass in the chemical strengthening process of the glass. However, when ZrO ₂ is contained too high, the devitrification resistance of the glass may be weakened. On the other hand, when ZrO ₂ is contained too low, it is difficult to properly achieve the effect of improving the properties due to the addition of ZrO ₂ . Therefore, the alkali glass according to the present invention contains 1.5 to 4% by weight or less of ZrO ₂ .

Preferably, the alkali glass according to the invention may have a density of 2.50 g / cm ³ or less. According to this embodiment, the density of the glass may be low and it may be easy to achieve the weight reduction of the glass article. In particular, in a situation where the glass area is gradually increased due to the increase in the size of the glass applied device such as a display device, when the glass density decreases, the glass phenomenon reduces the warpage phenomenon and the weight of the glass applied device decreases. Can be. In addition, the weight of the glass itself can also be reduced with respect to a portable device or a device, thereby improving portability.

Also preferably, the alkali glass according to the present invention may have a Coefficient of Thermal Expansion (CTE) of 9.0 × 10 ⁻⁶ / ° C. to 11.0 × 10 ⁻⁶ / ° C. According to this aspect, when used with a material having a coefficient of thermal expansion in a similar range, such as a metal, an organic adhesive, and the like in a similar range, it is possible to prevent problems such as peeling due to the difference in thermal expansion.

Also preferably, the alkali glass according to the present invention may have a T ₄ of 1200 ° C or less at a temperature of 10 ⁴ dPas. According to this embodiment, since the T ₄ associated with the processing temperature of the glass is low, the processing of the glass can be facilitated, and energy and time required for processing the glass can be saved.

Also preferably, the alkali glass according to the present invention may have a strain point of 500 ° C. or less. In addition, the alkali glass according to the present invention may have an annealing point of 540 ° C. or less. Therefore, according to this aspect of the present invention, the moldability of the glass can be improved. In particular, since 3D molding of glass becomes easy and glass becomes easy to manufacture to a desired form, the utilization of glass can be improved further.

The tempered glass according to the present invention can be produced using the alkali glass described above. That is, the tempered glass according to the present invention, in terms of the oxide-based weight% display, SiO ₂ 62-75%, Al ₂ O ₃ 10.5-15%, Na ₂ O 15.5-18%, K ₂ O 3.1-7%, MgO It is a tempered glass with improved strength by chemically strengthening alkali glass containing 0.5 ~ 2%, CaO 0 ~ 2%, and ZrO ₂ 1.5 ~ 4%.

The tempered glass which concerns on this invention can be equipped with a compressive stress layer on the surface by a chemical strengthening process. In this case, the compressive stress (CS) of the compressive stress layer may exceed 200 MPa. That is, the alkali glass according to the present invention may have a surface compressive stress exceeding 200 MPa during chemical strengthening treatment. More preferably, the compressive stress of the surface compressive stress layer may exceed 400 MPa. More preferably, the surface compressive stress may exceed 600 MPa. According to this embodiment, since the compressive stress of the compressive stress layer is large, the mechanical strength of the tempered glass can be improved.

In addition, in the tempered glass according to the present invention, the thickness DOL of the compressive stress layer may exceed 10 μm. That is, in the alkali glass according to the present invention, the formed compressive stress layer thickness during the chemical strengthening treatment may exceed 10 um. More preferably, the thickness of the compressive stress layer may exceed 20 um. More preferably, the thickness of the compressive stress layer may exceed 40 um. According to this embodiment, since the thickness of the compressive stress layer is thick, the mechanical strength of the tempered glass can be improved. In particular, if the compressive stress layer thickness is thick, the glass may not be broken even at a certain depth of damage.

The display device according to the present invention may include the above-mentioned alkali glass. In particular, the display device according to the present invention may include tempered glass chemically strengthened the above-mentioned alkali glass. For example, the display device according to the present invention may be a display device such as LCD, PDP, LED, OLED, etc., and may include the above-mentioned tempered glass as a cover glass (protective glass).

Hereinafter, a method for producing the above-mentioned alkali glass according to a preferred embodiment of the present invention will be described.

1 is a flowchart schematically showing a method for producing an alkali glass according to an embodiment of the present invention.

Referring to Figure 1, first, the raw materials of the respective components contained in the glass are combined to be the target composition (S110). At this time, in the step S110, the oxide reference weight% display, SiO ₂ 62-75%, Al ₂ O ₃ 10.5-15%, Na ₂ O 15.5-18%, K ₂ O 3.1-3%, The raw material components are combined so as to contain 0.5 to 2% of MgO, 0 to 2% of CaO, and 1.5 to 4% of ZrO ₂ .

Preferably, the step S110 is based on the oxide-based weight% display, SiO ₂ 63-73%, Al ₂ O ₃ 10.5-14%, Na ₂ O 15.5-17%, K ₂ O 3.1-3 Raw material components can be combined so that% may be contained.

Next, the glass raw material thus combined is heated to a predetermined temperature, for example, 1500-1600 ° C. to melt the glass raw material (S120), and the molten glass is molded (S130). In this case, step S130 may be performed by a float method using a float bath, but the present invention is not necessarily limited to such a molding method. For example, the step S130, that is, the shaping of the glass may be performed by a down draw method or a fusion method.

As such, when the glass is molded in step S130, the molded glass is subjected to a slow cooling process is transferred to a slow cooling furnace (S140). The annealed glass is then cut to the desired size, and further processing such as polishing can be performed and made into a glass article through this series of processes.

As described above, the alkali glass produced by the glass manufacturing method according to an embodiment of the present invention, the density may be 2.50 g / cm ³ or less. In addition, the thermal expansion coefficient of the manufactured alkali glass may be 9.0 to 11.0 [× 10 ⁻⁶ / ° C.]. In addition, the alkali glass prepared as described above may have a T ₄ of 1200 ° C or less. In addition, the alkali glass produced in this way, a strain point may be 500 degrees C or less, and a slow cooling point may be 540 degrees C or less.

The tempered glass manufacturing method according to the present invention includes the step of chemically strengthening the glass produced by the above-described alkali glass manufacturing method.

That is, the tempered glass manufacturing method according to the present invention can perform the chemical strengthening treatment of the alkali glass manufactured through steps S110 to S140, after step S140. At this time, the chemical strengthening step may be performed by immersing the alkali glass in a molten salt such as potassium nitrate (KNO ₃ ) for a predetermined time, but the present invention is not necessarily limited to this chemical strengthening treatment method.

As such, the tempered glass manufactured by the tempered glass manufacturing method according to the embodiment of the present invention may have a surface compressive stress of more than 200 MPa and a compressive stress layer thickness of more than 10 um. Preferably, the tempered glass produced according to the present invention may have a surface compressive stress greater than 400 MPa and a compressive stress layer thickness greater than 20 um. More preferably, the tempered glass produced according to the present invention has a surface compressive stress of greater than 600 MPa and a compressive stress layer thickness of greater than 40 um.

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples. It should be understood, however, that the embodiments of the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. The embodiments of the present invention are provided to enable those skilled in the art to more fully understand the present invention.

Table 1 shows the glass composition and physical properties of the examples according to the present invention.

The raw material of each component was combined so that it might become a composition (weight-% basis) as shown in Table 1, and it heated and fuse | melted for 3 hours at the temperature of 1600 degreeC using the platinum crucible. At the time of melting, a platinum stirrer was inserted and stirred for 1 hour to homogenize the glass. Next, the molten glass was slowly cooled at 730 ° C to obtain the glass of each example. In addition, about the obtained glass, the composition was confirmed through the fluorescent X-ray analysis.

In addition, as physical properties for each Example glass, the density, thermal expansion coefficient, T ₄ , strain point and slow cooling point were measured by the following method, and the results are shown in Table 1.

(density)

About each Example glass, the density was measured using the Archimedes method. At this time, the density unit is g / cm ³ .

(Coefficient of Thermal Expansion) (CTE)

About each Example glass, the average coefficent of thermal expansion was measured using the dilatometer. At this time, the unit of thermal expansion coefficient is ^10-6 / ^degreeC .

(T ₄ )

For each example of glass, using a high-temperature viscometer to measure the viscosity was measured the temperature T ₄ at the time the viscosity to be 10 ⁴ dPa · s. At this time, a unit of T ₄ is ℃.

(Distortion point)

For each Example glass, the strain point was measured by the Fiber elongation method using ASTM C336. At this time, the unit of the distortion point is ° C.

(Slow cooling point)

For each Example glass, the slow cooling point was measured by the Fiber elongation method using ASTM C336. At this time, the unit of a slow cooling point is ° C.

Referring to Table 1, the glass of Examples (Examples 1 to 10) had a density of 2.50 g / cm ³ or less and an average coefficient of thermal expansion (CTE) of 9.0 to 11.0 (× 10 ⁻⁶ / ° C.). Confirmed.

Further, in the case of the glass of the examples, it was confirmed that T ₄ was 1200 ° C or less. And in the case of the glass of an Example, it was confirmed that the strain point is low at 500 degrees C or less, and the slow cooling point is also low at 540 degrees C or less.

Looking at the measurement results of the various physical properties of this embodiment, it can be seen that in the case of the alkali glass according to the present invention, the density is low and it is easy to achieve light weight. In the case of alkali-free glass according to the present invention, it can be seen that good processability of the glass is low T _4. In addition, in the case of the alkali glass according to the present invention, it can be seen that the strain point and the slow cooling point are low, so that glass forming such as 3D molding may be facilitated.

In addition, the alkali glass according to the present invention may have a high surface compressive stress and a high compressive stress layer thickness during chemical strengthening treatment.

In order to examine this effect, the surface compressive stress (CS) and compressive stress layer thickness (DOL) were measured after chemically strengthening the glass of Example 1, and the results are shown in Table 2.

At this time, the compressive stress and the compressive stress layer thickness were measured using a surface stress measuring instrument (FSM-6000LE).

Here, the chemical strengthening treatment was performed in such a manner that the glass of Example 1 was immersed in a bath containing potassium nitrate (KNO ₃ ) solution for a predetermined time. At this time, the chemical strengthening treatment temperature and time for Example 1 are as described in Table 2.

In addition, a glass of a predetermined comparative example was prepared for comparison with the chemical strengthening treatment effect of Example 1.

In this case, the comparative example glass, an oxide based on weight percentages, the respective raw materials such that the _{SiO 2 70.6%, Al 2 O} 3 1.9%, Na 2 O 13.3%, K 2 O 0.3%, MgO 4.6% and CaO 8.8% After the combination, a platinum crucible was heated and melted at a temperature of 1600 ° C. for 3 hours as in the above example, followed by slow cooling at 730 ° C.

The surface compressive stress (CS) and the compressive stress layer thickness (DOL) were measured after chemically strengthening the glass of the comparative example thus obtained, and the results are shown in Table 3.

Also, in this comparative example, the chemical strengthening treatment, the comparative example was done in a glass of potassium nitrate (KNO ₃₎ a bath (bath) solution contained in a manner that a predetermined period of time immersed. At this time, the chemical strengthening treatment temperature and time for the comparative glass is as shown in Table 3.

In addition, the measurement result of the compressive stress and compressive stress layer thickness with respect to the glass of Example 1 of Table 2 and Table 3, and the glass of a comparative example is shown in FIG. 2 for the convenience of a comparison.

Referring to Tables 2 and 3, and Figure 2, in the case of the glass of Example 1 according to the present invention, the compressive stress layer thickness is 30 um or more, while the surface compressive stress is as high as 640 MPa or more, more than 800 MPa or more, It can be seen that the formation is as close as 50 um. On the other hand, in the case of the glass of the comparative example, it can be seen that the compressive stress is relatively low, especially the compressive stress layer thickness is very thin, such as 5um to 11um.

Therefore, even when looking at the comparison results, it is confirmed that when the chemically strengthened glass is manufactured using the alkali glass according to the present invention, the compressive stress layer thickness is increased while securing a surface compressive stress of a predetermined level or more. Can be.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It will be understood that various modifications and changes may be made without departing from the scope of the appended claims.

Claims (17)

In terms of weight percent oxide,
SiO ₂ 62-75%;
Al ₂ O ₃ 10.5-15%;
Na ₂ O 15.5-18%;
K ₂ O 3.1-7%;
MgO 0.5-2%;
CaO 0-2%; And
ZrO ₂ 1.5 ~ 4%
Alkali glass, characterized by containing. The method of claim 1,
In terms of weight percent oxide,
SiO ₂ 63-73%;
Al ₂ O ₃ 10.5 to 14%;
Na ₂ O 15.5-17%; And
K ₂ O 3.1 ~ 5%
Alkali glass, characterized by containing. The method of claim 1,
The density is 2.50 g / cm <^3> or less, and a thermal expansion coefficient is 9.0 * 10 <^-6> / degreeC-11.0 * 10 <^-6> / degreeC, The alkali glass characterized by the above-mentioned. The method of claim 1,
Wherein the temperature at a viscosity of 10 &lt; ⁴ &gt; dPas is 1200 DEG C or less. The method of claim 1,
Strain point is 500 degrees C or less, and slow cooling point is 540 degrees C or less, The alkali glass characterized by the above-mentioned. Tempered glass chemically strengthened the alkali glass according to any one of claims 1 to 5. The method according to claim 6,
Tempered glass, characterized in that the surface compressive stress exceeds 200 MPa, the compressive stress layer thickness exceeds 10 um. The method according to claim 6,
Tempered glass, the surface compressive stress exceeds 400 MPa, the compressive stress layer thickness exceeds 20 um. A display device comprising the alkali glass according to any one of claims 1 to 5. In terms of weight percent oxide,
SiO ₂ 62-75%;
Al ₂ O ₃ 10.5-15%;
Na ₂ O 15.5-18%;
K ₂ O 3.1-7%;
MgO 0.5-2%;
CaO 0-2%; And
ZrO ₂ 1.5 ~ 4%
Alkali glass production method comprising the step of combining the glass raw material to contain. The method of claim 10,
The glass raw material combination step,
In terms of weight percent oxide,
SiO ₂ 63-73%;
Al ₂ O ₃ 10.5 to 14%;
Na ₂ O 15.5-17%; And
K ₂ O 3.1 ~ 5%
An alkali glass production method characterized by containing a. The method of claim 10,
The density of the produced glass is 2.50 g / cm ³ or less, and the thermal expansion coefficient of the manufactured glass is 9.0x10 <^-6> / degreeC-11.0x10 <^-6> / degreeC, The alkali glass manufacturing method characterized by the above-mentioned. The method of claim 10,
Wherein the glass has a viscosity of 10 &lt; ⁴ &gt; dPas and a temperature of 1200 DEG C or less. The method of claim 10,
The strain point of the produced glass is 500 degrees C or less, and the slow cooling point of the manufactured glass is 540 degrees C or less, The alkali glass manufacturing method characterized by the above-mentioned. A method for producing tempered glass, comprising the step of chemically strengthening a glass produced by the method of producing an alkali glass according to claim 10. 16. The method of claim 15,
The produced tempered glass has a surface compressive stress of more than 200 MPa and a compressive stress layer thickness of more than 10 um. 16. The method of claim 15,
The produced tempered glass has a surface compressive stress of more than 400 MPa and a compressive stress layer thickness of more than 20 um.

Images