WO2014007224A1 - Glass production method and chemically strengthened glass - Google Patents

Description

Glass manufacturing method, chemically strengthened glass

The present invention relates to a chemically tempered glass used for an electronic device, for example, a casing or a decorative product such as a communication device or an information device that can be carried and used, and a method for producing the glass.

Cases and decorations for electronic devices such as mobile phones are selected and used from materials such as resin and metal in consideration of various factors such as decorativeness, scratch resistance, workability, and cost. Yes.

In recent years, attempts have been made to use glass that has not been conventionally used as a material of a casing (see Patent Document 1). According to Patent Document 1, in an electronic device such as a mobile phone, it is said that a unique decoration effect with a sense of transparency can be exhibited by forming the casing body from glass.

On the other hand, casings and decorations of electronic devices that can be used with a mobile phone or the like are required to have high strength in consideration of damage due to drop impact during use and contact scratches due to long-term use.

As a method for increasing the strength of glass, a method of forming a compressive stress layer on the glass surface is generally known. Typical methods for forming a compressive stress layer on the glass surface include an air cooling strengthening method (physical strengthening method) and a chemical strengthening method (ion exchange strengthening method). The air cooling strengthening method (physical strengthening method) is a method in which the glass plate surface heated to the vicinity of the softening point is rapidly cooled by air cooling or the like. In addition, the chemical strengthening method (ion exchange strengthening method) is a method in which alkali metal ions (typically Li ions and Na ions) having a small ion radius existing on the glass plate surface are obtained by ion exchange at a temperature below the glass transition point. , A method of exchanging with alkali ions having a larger ionic radius (typically, Na ions or K ions for Li ions and K ions for Na ions).

For example, the glass used for the housing is usually used with a thickness of 2 mm or less. Thus, when the air cooling strengthening method is applied to a thin glass plate, it is difficult to form a compressive stress layer because it is difficult to secure a temperature difference between the surface and the inside. For this reason, the target high-strength characteristic cannot be obtained in the glass after the tempering treatment.
Further, in the air cooling strengthening method, there is a great concern that the flatness of the glass plate is impaired due to variations in the cooling temperature. In particular, for thin glass plates, there is a great concern that the flatness will be impaired, and the texture that is the object of the present invention may be impaired. From these points, the glass plate is preferably strengthened by the latter chemical strengthening method.

Japanese Unexamined Patent Publication No. 2009-61730

-Cases and ornaments of electronic devices such as mobile phones are required to have various design expressions reflecting the diversity of consumer preferences. The color tone is one of the most important designs. The glass used for the housing is required to faithfully reproduce the color tone based on the data obtained through marketing activities and the color tone determined by the designer.

However, the present inventors have chemically strengthened glass containing a coloring component in order to increase the mechanical strength of the glass. Depending on the cooling rate in the temperature range from the chemical strengthening treatment temperature to 300 ° C. after the chemical strengthening treatment. We found a new problem that surface compressive stress changes.

Therefore, an object of the present invention is to provide a glass manufacturing method having high strength and a desired color tone, and chemically strengthened glass.

As a result of various studies, the inventor suppresses a decrease in surface compressive stress by controlling a cooling rate in a specific temperature range after the chemical strengthening treatment when chemically strengthening the glass containing the coloring component. I found that I can do it.
That is, the glass manufacturing method of the present invention is characterized by cooling a temperature range from a chemical strengthening treatment temperature to 300 ° C. at a cooling rate of 30 ° C./min or higher after chemically strengthening the glass containing a coloring component. To do.
In addition, the glass production method of the present invention is characterized by cooling the temperature range from the chemical strengthening treatment temperature to 300 ° C. at a cooling rate of 200 ° C./min or higher after chemically strengthening the glass containing the coloring component. To do.

Moreover, the manufacturing method of the glass of this invention is the said before the chemical strengthening process of the glass containing a coloring component, and after cooling the temperature range from a chemical strengthening process temperature to 300 degreeC with the cooling rate of 30 degree-C / min or more. A step of measuring the amount of change in the color tone of the glass, a step of obtaining an expected amount of change in the color tone of the glass due to the chemical strengthening treatment and the cooling based on the amount of change in the color tone, and a desired color tone and the amount of the expected change. Preparing and melting glass raw materials so as to obtain a glass composition, forming the obtained molten glass, chemically strengthening the molded glass, and cooling the chemically strengthened glass at a cooling rate It is characterized by providing.

Further, in the glass manufacturing method of the present invention, when the chemical strengthening treatment temperature in the chemical strengthening treatment is A, the cooling is performed at a temperature within the range of (A-150) ° C. to (A-50) ° C. after the cooling. Glass is heat-treated.

In addition, the method for producing the glass of the present invention includes the following formula (I): chromaticity a ^* of reflected light before chemical strengthening treatment by the L ^* a ^* b ^* color system (F2 light source) and chemical strengthening The difference from the chromaticity a ^* of the reflected light after treatment, cooling and heat treatment is Δa ^* , which is expressed by the following formula (II), before chemical strengthening treatment by the L ^* a ^* b ^* color system (F2 light source) a chromaticity b ^* of the reflected light, chemical strengthening treatment, if the difference between the chromaticity b ^* after cooling and after the heat treatment the reflected light is [Delta] b ^*, and color tone change amount represented by the following formula (III) is 0 .6 or less.
Δa ^* = a ^* value (before chemical strengthening treatment) −a ^* value (chemical strengthening treatment, after cooling and after heat treatment) (I)
Δb ^* = b ^* value (before chemical strengthening treatment) −b ^* value (chemical strengthening treatment, after cooling and after heat treatment) (II)
√ ((Δa ^* ) ² + (Δb ^* ) ² ) · (III)
The glass manufacturing method of the present invention is characterized in that the glass after the heat treatment has a reduction rate of the surface compressive stress of less than 25% as compared with the glass before the heat treatment.

Further, the method of manufacturing the glass of the present invention, as a coloring component of _{glass, Fe 2 O 3, Co 3} O 4, NiO, CuO, TiO 2, MnO, Cr 2 O 3, V 2 O 5, Bi 2 O 3 And at least one component selected from the group consisting of Se and 0.1 to 7% in terms of mole percentage based on oxide.

In addition, the glass production method of the present invention, as a glass, is expressed in terms of a molar percentage based on oxide, and SiO ₂ is 55 to 80%, Al ₂ O ₃ is 0 to 16%, B ₂ O ₃ is 0 to 12%. , Na ₂ O 5-20%, K ₂ O 0-8%, MgO 0-15%, CaO 0-15%, ΣRO (R is any of Mg, Ca, Sr, Ba and Zn ΣRO represents the total amount of RO contained in the specification, hereinafter the same shall apply) 0 to 18%, ZrO ₂ 0 to 1%, coloring components (Fe ₂ O ₃ , 0.1 to 7% of at least one component selected from the group consisting of Co ₃ O ₄ , NiO, CuO, TiO ₂ , MnO, Cr ₂ O ₃ , V ₂ O ₅ , Bi ₂ O ₃ , and Se) After preparing the glass raw material, melt the glass raw material and The scan characterized by forming the glass.

Further, the chemical strengthening treatment is performed so that the surface compressive stress layer on the surface of the glass obtained by the glass manufacturing method of the present invention has a depth of 5 μm or more and the surface compressive stress layer has a surface compressive stress of 300 MPa or more. It is characterized by performing.

The chemically strengthened glass of the present invention is characterized by being produced by the above-described manufacturing method.

Further, the chemically strengthened glass of the present invention is used for an exterior member.

According to the present invention, a glass having high strength can be produced. Moreover, the glass containing a coloring component with little change of the color tone before and behind a chemical strengthening process can be produced.

It is a schematic flowchart which concerns on 1st Embodiment of the manufacturing method of the glass of this invention.

The glass manufacturing method of the present invention comprises a step of cooling a temperature range from a chemical strengthening treatment temperature to 300 ° C. at a cooling rate of 30 ° C./min or higher after chemically strengthening the glass containing a coloring component. The glass that has been cooled at a rate of less than 30 ° C./min after the chemical strengthening treatment has a surface compressive stress on the surface of the glass formed by the chemical strengthening treatment, compared with a glass that has been cooled at a cooling rate of 30 ° C./min or more. Low and the mechanical strength of the glass is inferior. This is because, after the glass is chemically strengthened, when the cooling rate is less than 30 ° C./min, the network structure of atoms constituting the glass changes during cooling, and the glass surface formed by the chemical strengthening treatment This is thought to occur because the compressive stress is relaxed. A preferable cooling rate is 50 ° C./min or more, more preferably 100 ° C./min or more, further preferably 200 ° C./min or more, and particularly preferably 300 ° C./min or more.

The chemical strengthening treatment temperature indicates the treatment temperature of the molten salt (chemical strengthening treatment liquid) during the chemical strengthening treatment of the glass. Usually, in the chemical strengthening treatment of glass, the glass is immersed in the molten salt in a state where the molten salt is heated to about 400 ° C. to 550 ° C. and held for a certain period of time. By doing so, alkali metal ions (typically, Li ions and Na ions) present on the glass surface are converted into alkali metal ions (typically, having a larger ion radius than the alkali metal ions in the molten salt). It is Na ion or K ion for Li ion, and K ion for Na ion). After holding for a certain period of time, the glass after the chemical strengthening treatment is taken out from the molten salt and cooled to room temperature. Here, after taking out the glass from the molten salt, it is important to control the cooling rate in the temperature range from the chemical strengthening treatment temperature to 300 ° C. to a predetermined rate or more in order to suppress the decrease in the mechanical strength of the glass. is there.

Here, if the cooling rate of the glass after the chemical strengthening treatment is controlled to 30 ° C./min or more, there is a problem that the color tone of the glass changes before and after the chemical strengthening treatment. The reason why the color tone of the glass is changed is considered to be due to the following mechanism.
The coloring component contained in the glass is a component typically called a transition metal element. These coloring components have a plurality of valences. For this reason, the colored components contained in the glass are the same element and have different valences, and they coexist with them in equilibrium. Some of these coloring components have a plurality of coordination numbers. Therefore, like the valence, the colored components contained in the glass are the same element and have different coordination numbers, and coexist with them in equilibrium. These colored components are different in the color tone of the glass present depending on the state existing in the glass, that is, the valence balance and the coordination number equilibrium described above.
In addition, the “glass containing a coloring component” in the present invention contains 0.01 mol% or more of the coloring component in the glass. Moreover, when it contains several types of coloring components in glass, it means that the total amount of these coloring components contains 0.01 mol% or more.

The difference in the color tone of the glass due to the difference in the valence and coordination number of the coloring components is, for example, as follows.
As for the iron component, the glass exhibits a light blue color if the valence balance is greater than Fe ²⁺ , and the glass exhibits a pink to light yellow color if it is greater than Fe ³⁺ . If the valence is Fe ³⁺ and the coordination number equilibrium is 6-coordinate, the glass exhibits pink to pale yellow, and if it has 4-coordination, the glass exhibits yellowish brown color.
The cobalt component has a valence of Co ²⁺ , and if the coordination number equilibrium is 6-coordinate, the glass exhibits red to pink to purple, and if it has 4-coordination, the glass exhibits blue.
The nickel component has a valence of Ni ²⁺ , and the glass exhibits a yellow color if the coordination number equilibrium is 6-coordinate, and if it is 4-coordinate, the glass exhibits a reddish purple color.
If the valence balance is more than Cu ⁺ , the glass will be colorless, and if the copper component is more than Cu ²⁺ , the glass will be blue.

As for the titanium component, if the valence is from Ti ³⁺ , the glass exhibits a bluish purple to blue color. If the valence is from Ti ⁴⁺ , the glass exhibits a colorless color.
Manganese component, if coordination number six coordinating valence Mn ²⁺ glass exhibits a light orange, glass exhibits a colorless if coordination number is 4 coordinating valence Mn ^2+, atoms If the valence is Mn ³⁺ and the coordination number is 4-coordinate, the glass exhibits a reddish purple color.
If the valence is from Cr ³⁺ , the glass will exhibit a green color, and if it is from Cr ⁶⁺ , the glass will exhibit a yellow color.
As for the vanadium component, the glass exhibits a green color when the valence is from V ³⁺ , the glass exhibits a blue color from V ⁴⁺ , and the glass exhibits a colorless to yellow color from V ⁵⁺ .

The glass manufacturing method of the present invention further includes the steps of the following two embodiments with respect to the color tone change of the glass containing such a coloring component.

(First embodiment)
FIG. 1 is a schematic flow diagram of a glass manufacturing method according to the first embodiment. That is, a glass containing a coloring component is prepared, and the color tone change amount of the glass before and after the chemical strengthening treatment and after cooling the temperature range from the chemical strengthening treatment temperature to 300 ° C. at a cooling rate of 30 ° C./min or more. A step of measuring, a step of obtaining an expected change in the color tone of the glass due to the chemical strengthening treatment and the cooling based on the amount of change in the color tone, and a glass composition determined based on the desired color tone and the expected amount of change. It comprises a step of preparing and melting a glass raw material and molding the obtained molten glass, a step of chemically strengthening the molded glass, and a step of cooling the chemically strengthened glass.

Each step of the glass manufacturing method according to the first embodiment will be described.

The step of measuring the amount of change in color tone of the glass containing the coloring component before chemical strengthening treatment and after cooling the temperature range from the chemical strengthening treatment temperature to 300 ° C. at a cooling rate of 30 ° C./min or more, This is a process for obtaining data on how the color tone of the glass changes before and after the chemical strengthening treatment. In this step, glass color tone change data is accumulated when parameters such as the mother composition of glass, types and combinations of coloring components, and content are changed. Since this step is for obtaining an expected change in the color tone of the glass used when determining the glass composition described later, it is not always necessary to perform this step every time the glass is produced. That is, if there is already obtained glass color change data, it can be omitted by using them.

For the color tone change amount of the glass, for example, an L ^* a ^* b ^* color system standardized by CIE (International Commission on Illumination) can be used. In this case, each change amount of L ^* , a ^* , and b ^* is converted into data as a color tone change amount. Other color systems may be used. The cooling rate in this step is preferably the cooling rate when the glass is taken out from the molten salt after the chemical strengthening treatment and cooled without using a forced cooling means in a room temperature atmosphere. In this case, the cooling rate is 300 ° C./min to 500 ° C./min.

The process of obtaining the expected change in the color tone of the glass due to the chemical strengthening treatment and cooling based on the color tone change amount is the change in the color tone of the glass containing the coloring component when the chemical strengthening treatment and cooling based on the above steps are performed. This is the process of predicting what will happen. This is based on a plurality of data obtained in the step of measuring the color tone change amount of the glass, and predicts a color tone before chemical strengthening treatment for finally obtaining a glass having a desired color tone. This largely depends on the mother composition of the glass (for example, alkali metal component or alkaline earth metal component) and the type, combination, and content of the coloring component, and is often used in the process of measuring the color tone change amount of the glass. If the color tone change amount data is obtained, a more accurate predicted change amount can be obtained. As in the previous step, when using the expected change data of the glass obtained in this step, it is considered that the step is substantially performed even if this step is not performed every time the glass is manufactured. be able to.

The step of compounding a glass raw material so as to have a glass composition determined based on a desired color tone and an expected change amount, and then melting and molding the obtained molten glass is a glass obtained after chemical strengthening treatment that is finally obtained. The color tone before the chemical strengthening treatment is determined using the desired color tone and the expected change amount obtained by the step of obtaining the expected change amount of the color tone of the glass so that the color tone is similar to the desired color tone. And based on the determined color tone, glass composition, such as a mother composition of glass and the kind of color component, a combination, content, is determined. Next, a glass raw material is prepared so as to have this glass composition, and then the glass raw material is melted, and the obtained molten glass is formed into a desired shape. Further, the glass may be cut, polished, etc. and processed into an appropriate shape. In addition, it is preferable that the coloring component contained in the glass composition determined in this step is the same type and the same combination as the coloring component contained in the glass used in the step of measuring the color change amount. This differs in the tendency of color tone change before and after the chemical strengthening treatment depending on the coloring component of the glass. For this reason, it is possible to improve the accuracy of the expected change amount by using the same kind and the same combination of the coloring components, and thus it is possible to obtain chemically strengthened glass close to the desired color tone.

The step of chemically strengthening the formed glass is a step of chemically strengthening the glass formed by the previous step. The chemical strengthening treatment can use an appropriate method described later.

The process of cooling the chemically strengthened glass is a process of taking out the glass from the molten salt and cooling it after the chemical strengthening process. As described above, the compressive stress and color tone of the glass surface are different depending on the cooling condition of the glass after the chemical strengthening treatment. Therefore, in this step, it is preferable to cool at the same cooling rate as the cooling rate employed in the step of measuring the color tone change amount of the glass. By doing in this way, the precision of the said expected variation | change_quantity can be improved and the glass of the color tone as expected can be obtained finally. Further, the cooling rate affects the color tone of the glass as described above. Therefore, the cooling rate in this step may be cooled at a cooling rate different from the cooling rate employed in the step of measuring the color tone change amount of the glass for the purpose of adjusting the color tone.

The glass manufacturing method according to the first embodiment can provide chemically tempered glass having a desired color tone without reducing the surface compressive stress of the glass after chemical tempering treatment by providing the above steps.

(Second Embodiment)
A method for manufacturing glass according to the second embodiment will be described below.
In the glass manufacturing method according to the second embodiment, after chemically strengthening the glass containing the coloring component, the temperature range from the chemical strengthening temperature to 300 ° C. is cooled at a cooling rate of 30 ° C./min or more. Next, a step of heat-treating the glass at a temperature within the range of (A-150) ° C. to (A-50) ° C. when the chemical strengthening treatment temperature in the chemical strengthening treatment is A is provided. As described above, after chemically strengthening the glass containing the coloring component, the glass formed by the chemical strengthening treatment by cooling the temperature range from the chemical strengthening treatment temperature to 300 ° C. at a cooling rate of 30 ° C./min or more. A glass having high mechanical strength can be obtained without reducing the surface compressive stress. Here, when the glass containing a coloring component is cooled at the cooling rate, there is a problem that the color tone of the glass changes before and after the chemical strengthening treatment.

Therefore, in the glass manufacturing method according to the second embodiment, after chemical strengthening treatment and cooling, the temperature is within the range of (A-150) ° C. to (A-50) ° C. above the chemical strengthening treatment temperature A. By further including a step of heat-treating at a temperature, it is possible to obtain a glass containing a coloring component with little change in color tone before and after the chemical strengthening treatment. That is, the color tone of the glass containing the coloring component subjected to the chemical strengthening treatment and cooling is changed as compared with that before the chemical strengthening treatment. By heat-treating such glass, it is possible to return to the color tone of the glass before chemical strengthening treatment, and a chemically strengthened glass having a desired color tone can be obtained.
The glass manufacturing method according to the second embodiment is to restore the color tone of the glass before the chemical strengthening treatment by heat-treating the glass after the chemical strengthening treatment. Therefore, the glass adjusted so that the glass before a chemical strengthening process may become a desired color tone is used.
In the present invention, “after the glass is cooled after the chemical strengthening treatment” means that, when the heat treatment is performed, the temperature of the glass is equal to or lower than the heat treatment temperature. That is, in the glass manufacturing method according to the second embodiment, the chemical strengthening treatment is performed, the glass is cooled to a temperature equal to or lower than the heat treatment temperature, and then the temperature is lower than the chemical strengthening treatment temperature A ( A-150) means a step of performing a heat treatment at a temperature within the range of (A-50) ° C. to (A-50) ° C. Therefore, after the chemical strengthening treatment, if the glass is cooled to a temperature between room temperature and the heat treatment temperature, the glass is cooled even if the glass temperature is 300 ° C. or higher. The glass can be heat-treated by raising or maintaining the glass temperature from the state.

If the temperature of the heat treatment is higher than the temperature 50 ° C. lower than the chemical strengthening treatment temperature A, it is not preferable because the surface compression stress of the glass is relaxed in a short time. On the other hand, if the temperature is lower than the temperature 150 ° C. lower than the chemical strengthening treatment temperature A, it takes time to restore the color tone of the glass, and the productivity deteriorates.
The longer the heat treatment time, the larger the amount of change in the color tone of the glass, and the color tone can be restored. At the same time, the surface compression stress of the glass is relaxed. Therefore, when the temperature of the heat treatment is high, it is preferable to perform the treatment in a short time. The heat treatment time is preferably 10 minutes to 5 hours, more preferably 20 minutes to 3 hours, and most preferably 30 minutes to 2 hours.

The reason why the color tone of the glass returns to the color tone before the chemical strengthening treatment by the heat treatment is considered to be due to a phenomenon opposite to the mechanism of the change in the color tone of the glass. That is, in the glass containing the coloring component, the equilibrium state of the valence and coordination number of the coloring component in the glass changed in the chemical strengthening treatment and cooling is restored to the equilibrium state before the chemical strengthening treatment by the heat treatment. The color tone of the tempered glass returns to the color tone before the chemical strengthening treatment.

The return of the color tone of the glass by the heat treatment is preferably in the following range. That is, the chromaticity a ^* of reflected light before chemical strengthening treatment by the L ^* a ^* b ^* color system (F2 light source) represented by the following formula (I), and reflection after chemical strengthening treatment, cooling and heat treatment The difference from the light chromaticity a ^* is Δa ^* , the chromaticity b ^* of the reflected light before chemical strengthening treatment by the L ^* a ^* b ^* color system (F2 light source) represented by the following formula (II), When the difference from the chromaticity b ^* of the reflected light after chemical strengthening treatment, cooling and heat treatment is Δb ^* , it is preferable that the amount of change in color tone represented by the following formula (III) is 0.6 or less. Thereby, the difference between the reflection color tone of the glass before the chemical strengthening treatment and the reflection color tone of the glass after the heat treatment can be reduced.
Δa ^* = a ^* value (before chemical strengthening treatment) −a ^* value (chemical strengthening treatment, after cooling and after heat treatment) (I)
Δb ^* = b ^* value (before chemical strengthening treatment) −b ^* value (after chemical strengthening treatment, after cooling and after heat treatment) (II)
√ ((Δa ^* ) ² + (Δb ^* ) ² ) (III)
By setting the color tone change amount to 0.6 or less, it is difficult to visually distinguish the color tone difference, and it can be determined that there is almost no color tone change. The color change amount is more preferably 0.5 or less, and still more preferably 0.4 or less.

The a ^* b ^* can be defined using the L ^* a ^* b ^* color system standardized by the CIE (International Lighting Commission). Note that a ^* b ^* uses an F2 light source.
Δa ^* and Δb ^* are determined by the following method. Using a spectrocolorimeter (for example, Color i7 manufactured by X-Rite Co., Ltd.), the reflection chromaticity of the F2 light source of each glass is measured, and Δa ^* and Δb ^* are calculated using the measurement results. The measurement is performed by placing a white resin plate on the back side of the glass (that is, the back side of the surface irradiated with light from the light source).

As described above, the color tone change of the glass before and after the chemical strengthening treatment can be suppressed by performing the heat treatment, but on the other hand, the surface compressive stress formed by the chemical strengthening treatment may be relaxed. Therefore, the glass manufacturing method according to the second embodiment has a reduction rate of the surface compressive stress of the glass after the heat treatment of less than 25% as compared with the glass subjected to the chemical strengthening treatment and the cooling (that is, the glass before the heat treatment). It is preferable that By doing in this way, while suppressing the color tone change of glass, the reduction | decrease of the surface compressive stress (henceforth a surface compressive stress is also only called "CS") of chemically strengthened glass is suppressed to a fixed level, and it uses for practical use. High strength glass can be obtained. The reduction rate of the surface compressive stress of the glass after the heat treatment is preferably less than 20%, more preferably less than 15%, and even more preferably less than 10%.

Hereinafter, steps common to the first and second embodiments will be described.
The chemical strengthening treatment can be performed, for example, by immersing the glass in a molten salt at 400 ° C. to 550 ° C. for about 1 to 20 hours. The molten salt used in the chemical strengthening treatment, as long as it contains potassium ions or sodium ions, is not particularly limited, for example, molten salt of potassium nitrate (KNO ₃₎ is preferably used. Other, it may also be used molten salt of a mixture of a molten salt or potassium nitrate sodium nitrate (NaNO ₃₎ (KNO ₃₎ and sodium nitrate (NaNO _3).

In the glass manufacturing method of the present invention, the chemical strengthening treatment is a step of forming a surface compressive stress layer on the surface of the glass. The depth of the surface compressive stress layer formed on the surface of the glass (hereinafter, the depth of the surface compressive stress layer is also simply referred to as “DOL”) is preferably 5 μm or more, more preferably 10 μm or more, and even more preferably. Is subjected to chemical strengthening treatment so as to be 20 μm or more, particularly preferably 30 μm or more. When chemically strengthened glass is used for an exterior member, there is a high probability that contact damage will occur on the surface of the glass, and the mechanical strength of the glass may decrease. Therefore, if the DOL is increased, even if the surface of the chemically strengthened glass is scratched, it becomes difficult to break. On the other hand, in order to make it easy to cut the glass after the chemical strengthening treatment, the DOL is preferably set to 70 μm or less.

In the glass manufacturing method of the present invention, it is preferable to perform chemical strengthening treatment so that the surface compressive stress (CS) formed on the glass surface is 300 MPa or more. More preferably, the chemical strengthening treatment is performed so that the pressure is 500 MPa or more, more preferably 700 MPa or more, and particularly preferably 900 MPa or more. The mechanical strength of chemically strengthened glass increases as CS increases. On the other hand, if the CS becomes too high, the internal tensile stress may become extremely high, so the CS is preferably 1200 MPa or less.

Subsequently, the glass composition in the manufacturing method of the glass of this invention is demonstrated.
As a glass composition in the glass manufacturing method of the present invention, as a coloring component in glass, Fe ₂ O ₃ , Co ₃ O ₄ , NiO, CuO, TiO ₂ , MnO, Cr ₂ O ₃ , V ₂ O ₅ , BI It is preferable that at least one component selected from the group consisting of ₂ O ₃ and Se is contained in an amount of 0.1 to 7% in terms of mole percentage on the basis of oxide. By including the coloring component in the glass, it is possible to produce a glass having a color tone with high design properties. When a plurality of the coloring components are contained, it means that the total amount is 0.1 to 7%.

These coloring components may contain any of these if the total content is 0.1 to 7%, but each content is less than 0.01% The effect as a coloring component cannot be sufficiently obtained. Preferably it is 0.1% or more, More preferably, it is 0.2% or more. Moreover, if each content exceeds 6%, glass will become unstable and devitrification will occur. Preferably it is 5% or less, More preferably, it is 4% or less.

The coloring components in the glass are expressed in terms of a molar percentage based on oxides, 0 to 6% of Fe ₂ O ₃ , 0 to 6% of Co ₃ O ₄ , 0 to 6% of NiO, 0 to 6% of CuO, TiO ₂ 0-6%, MnO 0-6%, Cr ₂ O ₃ 0-6%, V ₂ O ₅ 0-6%, BI ₂ O ₃ 0-6%, Se 0-6 % Is preferably contained. Moreover, in order to express a desired color tone in glass, Fe ₂ O ₃ , Co ₃ O ₄ , NiO, CuO, TiO ₂ , MnO, Cr ₂ O ₃ , V ₂ O ₅ , Bi ₂ O ₃ , and It is preferable to use a combination of a plurality of components selected from the group consisting of Se. In addition, there exists a possibility that glass may become unstable that each content exceeds 6%.

In addition, in this specification, content of a coloring component shows conversion content when each component which exists in glass shall exist as a displayed oxide. For example, “containing 0 to 6% of Fe ₂ O ₃ ” means that the Fe content in the case where all of the Fe present in the glass is present in the form of Fe ₂ O ₃ , that is, Fe ₂ of Fe. This means that the content in terms of O ₃ is 0 to 6%. Regarding other coloring components, the equivalent content is also shown.

Although the color tone of the glass in the manufacturing method of the glass of this invention is not limited, For example, when producing the glass which exhibits black, it is preferable to use the following coloring components. In a glass other than the coloring components described in detail below, Fe ₂ O ₃ is contained in a combination of 1.5 to 6% and Co ₃ O ₄ in a combination of 0.1 to 1% as a coloring component in the glass. The glass can absorb the light in the visible region on the average while sufficiently absorbing the light in the visible region with a wavelength of 380 nm to 780 nm. In other words, when trying to obtain a glass exhibiting a black color, the brown and blue colors are reduced due to the presence of a wavelength region having a low absorption characteristic in the visible wavelength range of 380 nm to 780 nm, depending on the type and amount of the coloring component. May be black. On the other hand, what is called jet black can be expressed by setting it as the above-mentioned coloring component.

In order to obtain such light absorption characteristics, combinations of the coloring components other than those described above are as follows: Fe ₂ O ₃ is 0.01 to 4%, Co ₃ O ₄ is 0.2 to 3%, NiO 1.5-6%, Fe ₂ O ₃ 1.5-6%, NiO 0.1-1%, Fe ₂ O ₃ 0.01-4%, Co ₃ O ₄ 0.05-2%, NiO 0.05-2%, Cr ₂ O ₃ 0.05-2% in combination, Fe ₂ O ₃ 0.01-4%, Co ₃ O ₄ 0.05 ~ 2%, NiO 0.05 ~ 2%, MnO 0.05 ~ 2% in combination, Co ₃ O ₄ 0.01 ~ 0.2%, NiO 0.05 ~ 1%, TiO ₂ the combination of _{0.01 ~ 3%, Co 3 O} 4 0.01 to 0.2% of NiO 0.05 ~ 1% of TiO ₂ 0.01 ~ %, And a combination of from 0.01 to 3% CuO.

Further, by combining the coloring components in the glass, it is possible to obtain a glass that transmits a specific wavelength of ultraviolet light or infrared light while sufficiently absorbing light in the visible range of wavelength 380 nm to 780 nm. For example, by using a glass containing a combination of the aforementioned Fe ₂ O ₃ , Co ₃ O ₄ , NiO, MnO, Cr ₂ O ₃ , and V ₂ O ₅ as a coloring component, ultraviolet light having a wavelength of 300 nm to 380 nm Infrared light having a wavelength of 800 nm to 950 nm can be transmitted. Further, by using a glass containing a combination of the above-described Fe ₂ O ₃ and Co ₃ O ₄ as a coloring component, infrared light having a wavelength of 800 nm to 950 nm can be transmitted. For example, infrared light having a wavelength of 800 nm to 950 nm is used in an infrared communication device used for data communication of a mobile phone or a portable game device. Therefore, by combining the combination of the aforementioned coloring components and imparting infrared light transmission characteristics to the glass, for example, when glass is applied to a casing, an opening for an infrared communication device is provided in the casing. Can be applied without.

In addition to the above-described coloring components, 0.005 to 2% of at least one component selected from the group consisting of CeO ₂ , Er ₂ O ₃ and Nd ₂ O ₃ is contained as a component for adjusting the color tone of the glass May be. About the component which adjusts the color tone of glass, the conversion content (mole percentage display of an oxide basis) is shown like a coloring component.

By containing at least one component selected from the group consisting of CeO ₂ , Er ₂ O ₃ , and Nd ₂ O ₃ as a component for adjusting the color tone of glass in a total of 0.005% or more, the wavelength in the visible region A difference in light absorption characteristics within the region can be reduced, and a glass having a so-called jet black black color tone without exhibiting brown or blue can be obtained. Moreover, it can suppress that glass becomes unstable and devitrification arises by making content of the component which adjusts the color tone of said glass into 2% or less. The total content of the components for adjusting the color tone of the glass is more preferably 0.01 to 1.8%, and still more preferably 0.1 to 1.5%.

As the glass in the method for producing glass of the present invention, together with the above-described coloring components, SiO ₂ is 55 to 80%, Al ₂ O ₃ is 0 to 16%, and B ₂ O _{3 is} expressed in terms of mole percentage based on the following oxides. 0-12%, Na ₂ O 5-20%, K ₂ O 0-8%, MgO 0-15%, CaO 0-15%, ΣRO (R is Mg, Ca, Sr, Ba , Zn) containing 0 to 18% and ZrO ₂ containing 0 to 1%.

Hereinafter, the composition of the glass other than the coloring component of the glass for chemical strengthening of the present invention will be described using the mole percentage display content unless otherwise specified.

SiO ₂ is a component constituting the skeleton of glass and essential. If it is less than 55%, the stability as glass will deteriorate, or the weather resistance will deteriorate. Preferably it is 60% or more. More preferably, it is 65% or more. If SiO ₂ exceeds 80%, the viscosity of the glass increases and the meltability decreases significantly. Preferably it is 75% or less, typically 70% or less.

Al ₂ O ₃ is a component that improves the weather resistance and chemical strengthening properties of the glass, and is not essential, but can be contained as necessary. When Al ₂ O ₃ is contained, if it is less than 3%, the weather resistance is lowered. Preferably it is 4% or more, typically 5% or more.
If Al ₂ O ₃ exceeds 16%, the viscosity of the glass becomes high and uniform melting becomes difficult. Preferably it is 14% or less, typically 12% or less.
In the case where high CS is formed on the surface of the glass by chemical strengthening treatment, Al ₂ O ₃ is preferably 5 to 15% (but not including 5%). Further, in the case of increasing the meltability of the glass and producing it at low cost, Al ₂ O ₃ is preferably 0 to 5% (in this case, including 5%).

B ₂ O ₃ is a component that improves the weather resistance of the glass, and is not essential, but can be contained as necessary. When B ₂ O ₃ is contained, if it is less than 4%, a significant effect may not be obtained for improving weather resistance. Preferably it is 5% or more, and typically 6% or more.
If B ₂ O ₃ exceeds 12%, striae due to volatilization may occur and the yield may decrease. Preferably it is 11% or less, typically 10% or less.

Na ₂ O is a component that improves the meltability of the glass, and is essential because a surface compressive stress layer is formed by ion exchange. If it is less than 5%, the meltability is poor, and it becomes difficult to form a desired surface compressive stress layer by ion exchange. Preferably it is 7% or more, typically 8% or more.
When Na ₂ O exceeds 20%, the weather resistance decreases. Preferably it is 18% or less, typically 16% or less.

K ₂ O is a component that improves the meltability of the glass, and has the effect of increasing the ion exchange rate in chemical strengthening, but is not essential, but is a preferable component. When it contains K ₂ O, if it is less than 0.01%, there is a possibility that a significant effect cannot be obtained for improving the melting property, or a significant effect cannot be obtained for improving the ion exchange rate. Typically, it is 0.3% or more. When K ₂ O exceeds 8%, the weather resistance decreases. Preferably it is 6% or less, typically 5% or less.

RO (R represents Mg, Ca, Sr, Ba, Zn) is a component that improves the meltability of the glass, and although it is not essential, it can contain any one or more as required. In that case, if the total RO content ΣRO (R represents Mg, Ca, Sr, Ba, Zn) is less than 1%, the meltability may decrease. Preferably it is 3% or more, typically 5% or more. When ΣRO (R represents Mg, Ca, Sr, Ba, Zn) exceeds 18%, the weather resistance decreases. It is preferably 15% or less, more preferably 13% or less, and typically 11% or less.

MgO is a component that improves the meltability of the glass, and although it is not essential, it can be contained if necessary. When it contains MgO, if it is less than 3%, there is a possibility that a significant effect cannot be obtained for improving the meltability. Typically 4% or more. When MgO exceeds 15%, the weather resistance decreases. Preferably it is 13% or less, typically 12% or less.

CaO is a component that improves the meltability of the glass, and although it is not essential, it can be contained if necessary. When CaO is contained, if it is less than 0.01%, a significant effect for improving the meltability cannot be obtained. Typically, it is 0.1% or more. If CaO exceeds 15%, the chemical strengthening properties are lowered. Preferably it is 13% or less, typically 12% or less. When it is desired to enhance the chemical strengthening properties of the glass, it is preferable that the glass is not substantially contained.
When high CS is formed on the glass surface by the chemical strengthening treatment, CaO is preferably 0 to 5% (however, 5% is not included). Further, in the case of increasing the meltability of the glass and producing it at low cost, CaO is preferably 5 to 15% (in this case, including 5%).

SrO is a component for improving the meltability, and is not essential, but can be contained as necessary. When it contains SrO, if it is less than 1%, there is a possibility that a significant effect cannot be obtained for improving the meltability. Preferably it is 3% or more, and typically 6% or more. If SrO exceeds 15%, the weather resistance and chemical strengthening properties may be lowered. Preferably it is 12% or less, typically 9% or less.

BaO is a component for improving the meltability, and although not essential, it can be contained if necessary. When it contains BaO, if it is less than 1%, there is a possibility that a significant effect cannot be obtained with respect to improvement in meltability. Preferably it is 3% or more, and typically 6% or more. If BaO exceeds 15%, the weather resistance and chemical strengthening properties may be reduced. Preferably it is 12% or less, typically 9% or less.

ZnO is a component for improving the meltability, and is not essential, but can be contained as necessary. When it contains ZnO, if it is less than 1%, there is a possibility that a significant effect cannot be obtained with respect to improvement in meltability. Preferably it is 3% or more, and typically 6% or more. If ZnO exceeds 15%, the weather resistance may be lowered. Preferably it is 12% or less, typically 9% or less.

ZrO ₂ is a component that increases the ion exchange rate and is not essential, but may be contained in a range of less than 1%. If the ZrO ₂ content exceeds 1%, the meltability may be deteriorated and remain in the glass as an unmelted product. Typically no ZrO ₂ is contained.

In addition to the above components, the following components may be introduced into the glass composition.

SO ₃ is a component that acts as a fining agent, and although it is not essential, it can be contained if necessary. Fining effect expected in the case of less than 0.005% containing SO ₃ can not be obtained. Preferably it is 0.01% or more, More preferably, it is 0.02% or more. 0.03% or more is most preferable. On the other hand, if it exceeds 0.5%, it becomes a generation source of bubbles, and there is a possibility that the glass melts slowly or the number of bubbles increases. Preferably it is 0.3% or less, More preferably, it is 0.2% or less. 0.1% or less is most preferable.

SnO ₂ is a component that acts as a fining agent, and although it is not essential, it can be contained as necessary. When SnO ₂ is contained, if it is less than 0.005%, the expected clarification action cannot be obtained. Preferably it is 0.01% or more, More preferably, it is 0.05% or more. On the other hand, if it exceeds 1%, it becomes a generation source of bubbles, and there is a possibility that the glass melts slowly or the number of bubbles increases. Preferably it is 0.8% or less, More preferably, it is 0.5% or less. Most preferred is 0.3% or less.

Li ₂ O is a component for improving the meltability, and is not essential, but can be contained as necessary. When Li ₂ O is contained, if it is less than 1%, there is a possibility that a significant effect cannot be obtained for improving the meltability. Preferably it is 3% or more, and typically 6% or more. If Li ₂ O exceeds 15%, the weather resistance may decrease. Preferably it is 10% or less, typically 8% or less.

As the glass in the method for producing glass of the present invention, SiO ₂ is 55 to 80% and Al ₂ O ₃ is 5 to 16% (however, 5%) in the molar percentage display based on the following oxides together with the above coloring components. B ₂ O ₃ 0-12%, Na ₂ O 5-20%, K ₂ O 0-8%, MgO 0-15%, CaO 0-5% (but 5%). %), ΣRO (R represents Mg, Ca, Sr, Ba, Zn) 0 to 18% and ZrO ₂ 0 to 1% are preferable. By setting it as such glass, it becomes possible to form high CS on the glass surface by a chemical strengthening process, and chemically strengthened glass with high mechanical strength can be obtained.

As the glass in the method for producing glass of the present invention, in addition to the above-mentioned coloring components, SiO ₂ is 55 to 80% and Al ₂ O ₃ is 0 to 5% (however, 5% in terms of the mole percentage based on the following oxide) B ₂ O ₃ 0-12%, Na ₂ O 5-20%, K ₂ O 0-8%, MgO 0-15%, CaO 5-15% (but 5% And ΣRO (R represents Mg, Ca, Sr, Ba, Zn) 0 to 18% and ZrO ₂ 0 to 1% are preferable. By using such a glass, it becomes possible to melt-mold the glass at a low cost.

The method for producing the glass of the present invention is not particularly limited. For example, various glass raw materials are prepared in an appropriate amount, heated and melted, and then homogenized by defoaming, stirring, etc., and plate-like by a well-known downdraw method, press method, or the like. Or the like, or cast to form a desired shape. And after slow cooling, it cut | disconnects to a desired size and performs a grinding | polishing process as needed. Alternatively, the glass once molded into a lump is reheated to soften the glass and then press-molded to obtain a desired shape. The glass thus obtained is chemically strengthened. Then, the chemically strengthened glass is cooled at the cooling rate to obtain chemically strengthened glass.

The chemically strengthened glass of the present invention can increase the mechanical strength of the glass by chemical strengthening treatment. Moreover, since there is little change in the color tone of the glass before and after the chemical strengthening treatment, a glass with a desired color tone can be easily obtained. Therefore, it can be suitably used for applications requiring glass having high strength, scratch resistance, and design, for example, portable communication devices and housings for information devices.

As mentioned above, although an example was given and demonstrated about the manufacturing method of the glass of this invention, in the limit which is not contrary to the meaning of this invention, a structure can be changed suitably as needed.

Hereinafter, although it demonstrates in detail based on the Example of this invention, this invention is not limited only to these Examples.

The glass used for the Example and comparative example of this invention is demonstrated.
For Examples 1 to 3 in Table 1 (Example 1 is an Example, Examples 2 and 3 are Comparative Examples), oxides, hydroxides, carbonates, nitrates, etc. are generally used so as to have the compositions shown below. The glass raw materials that were used were appropriately selected and weighed so as to be 100 ml as glass. Note that SO ₃ is the remaining SO ₃ remaining in the glass after the addition of bow nitrate (Na ₂ SO ₄ ) to the glass raw material and decomposition of the bow nitrate, and is a calculated value.
The glass composition is expressed in terms of mole percentage in terms of oxide, SiO ₂ 63.1%, Na ₂ O 12.3%, K ₂ O 3.9%, MgO 10.3%, Al ₂ O ₃ 7.9% , TiO ₂ 0.3%, ZrO ₂ 0.4%, CoO 0.05%, NiO 0.7%, CuO 1.0%, and SO ₃ 0.1%.

Next, this raw material mixture is put into a platinum crucible, put into a 1500-1600 ° C. resistance heating electric furnace, the raw material is melted off in about 0.5 hours, melted for 1 hour, defoamed, The glass block was obtained by pouring into a mold having a length of about 50 mm, a width of about 100 mm, and a height of about 20 mm preheated to 300 ° C. and slowly cooled at a rate of about 1 ° C./min. The glass block was cut and ground to a size of 40 mm × 40 mm and a thickness of 0.8 mm, and finally both surfaces were polished to a mirror surface to obtain a plate-like glass.

The obtained plate-like glass was subjected to a chemical strengthening treatment and then cooled under the following cooling conditions. And the cooled glass was wash | cleaned and the chemically strengthened glass was obtained.
The chemical strengthening treatment was performed by immersing the glass in a molten salt composed of KNO ₃ (98%) and NaNO ₃ (2%) at 425 ° C. for 6 hours, respectively.
The glass after the chemical strengthening treatment was cooled at 1 ° C./min, 3 ° C./min, and 400 ° C./min. Note that, under the cooling rate conditions of 1 ° C./min and 3 ° C./min, the glass was placed in a batch-type electric furnace and cooled after the chemical strengthening treatment. Moreover, under the cooling rate condition of 400 ° C./min, after the chemical strengthening treatment, the glass was taken out from the molten salt and cooled in a room temperature atmosphere. In addition, cooling of the glass after a chemical strengthening process was performed on the said conditions until the glass became room temperature from the temperature of the molten salt at the time of a chemical strengthening process.

As the color tone of each glass of Examples and Comparative Examples, the chromaticity of reflected light from an F2 light source of L ^* a ^* b ^* color system standardized by CIE was measured. Further, the color tone change amount before and after the chemical strengthening process is obtained as the color tone change (Δa ^* and Δb ^* ) before and after the chemical strengthening process, and the color tone change amount √ ((Δa ^* ) ² + (Δb ^* ) ² ) is calculated therefrom ^. did. L ^* a ^* b ^* Color measurement of reflected light with color system F2 light source is performed by measuring the reflected chromaticity of each glass F2 light source using a spectrocolorimeter (X-Rite, Color i7). did. The measurement was performed by placing a white resin plate on the back side of the glass (that is, the back side of the surface irradiated with light from the light source).

About each of these glass, the decreasing rate (CS decreasing rate) of the surface compressive stress was confirmed.
For the CS reduction rate of glass, use the formula of [[surface compressive stress of 400 ° C./min]−[surface compressive stress of 1 ° C./min or 3 ° C./min]]/[surface compressive stress of 400 ° C./min]. It was.
The evaluation results are shown in Table 1.

As shown in Table 1, it can be seen that the glass of the example provides a chemically strengthened glass having a higher surface compressive stress and higher mechanical strength than the glasses of the comparative examples.

An example corresponding to the first embodiment will be described.
When obtaining chemically strengthened glass whose color tone of reflected light by the L ^* a ^* b ^* color system (F2 light source) is L ^* : 26.50, a ^* : -0.25, b ^* : -2.80 Is described.
First, using the glass having the glass composition described above, the color tone of the glass before the chemical strengthening treatment was measured and found to be L ^* : 26.41, a ^* : −0.73, b ^* : −2.20. It was. Next, this glass was chemically strengthened, and the temperature range from after chemical strengthening to 300 ° C. was cooled under cooling conditions of 400 ° C./min. And the cooled glass was wash | cleaned and the chemically strengthened glass was obtained. In the chemical strengthening treatment, molten glass of KNO ₃ (99%) and NaNO ₃ (1%) at 450 ° C. was used, and the glass was immersed in the molten salt for 6 hours. The color tone of the resulting chemical tempered glass was ^{measured, L *: 26.47, a *} : -0.31, b *: was -3.71. From the obtained chemical strengthening treatment before and after the color, the color tone variation of the ^{glass, ΔL *: -0.06, Δa *} : + 0.42, Δb *: was found to be -0.97.

The expected change amount was examined from the obtained color tone change amount. From the desired color and the expected variation, the aforementioned case based on the glass composition described above, the coloring component a ^* is negative direction, b ^* is applied in the positive direction, for example, the content of Co ₃ O ₄ and NiO The glass composition was determined by increasing the amount of the glass composition.
Next, glass raw materials were prepared and melted so as to have the determined glass composition, and the molten glass was formed into a plate-like glass. And glass was chemically strengthened. The chemically strengthened glass was cooled from the chemical strengthening treatment temperature to room temperature under the same cooling conditions (400 ° C./min) as in the step of measuring the color tone change amount of the glass to obtain chemically strengthened glass. When the color tone of the obtained chemically strengthened glass was measured, it was a chemically strengthened glass having a color tone substantially the same as the initial target color tone.
From the above, it can be seen that the example corresponding to the first embodiment can provide a chemically strengthened glass having high mechanical strength and a desired color tone.

Next, examples corresponding to the second embodiment will be described.
Using the same glass as in Examples 1 to 3, a plate-like glass was obtained by the same method. The obtained glass was subjected to a chemical strengthening treatment and then cooled under cooling conditions of 400 ° C./min. And the cooled glass was wash | cleaned and the chemically strengthened glass was obtained.
In the chemical strengthening treatment, each glass was immersed in a molten salt composed of KNO ₃ (99%) and NaNO ₃ (1%) at 450 ° C. for 2 hours.

This chemically strengthened glass was heat treated under the conditions shown in Table 2 as Examples 4 to 10. And for each glass, the color tone before chemical strengthening treatment, the color tone after chemical strengthening treatment / cooling, the color tone after heat treatment, the amount of color tone change before and after chemical strengthening treatment, the amount of color tone change by heat treatment (before and after chemical strengthening treatment and Change amount). The color tone measurement method is the same as that described above. The heat treatment was performed by placing glass in a batch type electric furnace and performing treatment at a predetermined temperature and a predetermined time.
The evaluation results are shown in Table 2.

As shown in Table 2, by performing heat treatment after chemical strengthening treatment / cooling, the amount of change between the color tone of the glass before chemical strengthening treatment and the color tone of the glass after heat treatment becomes 0.35 or less, and chemical strengthening of the desired color tone It can be seen that glass is obtained. Moreover, the reduction rate (CS reduction rate) of the surface compressive stress by heat processing is less than 25%, and it turns out that the chemically strengthened glass which performed heat processing is equipped with high mechanical strength.
From Table 2, the relationship between the heat treatment conditions and the color tone change amount is higher when the heat treatment temperature is higher and the heat treatment time is longer, and the color tone change amount is larger and can be closer to the color tone of the glass before chemical strengthening treatment. On the other hand, the relationship between the heat treatment conditions and the CS reduction rate is such that the higher the heat treatment temperature and the longer the heat treatment time, the greater the CS reduction rate. The heat treatment conditions shown in the examples of the second embodiment are examples, and the heat treatment conditions are determined in consideration of the glass composition, the glass color change amount, the CS reduction rate, the productivity, and the like. In addition, “I / X” shown in the column of the color tone change rate in Table 2 is an abbreviation for chemical strengthening treatment (Ion Exchange). In Table 2, “before and after I / X” refers to the amount of change in color tone between the color tone before chemical strengthening treatment (A) and the color tone after chemical strengthening treatment (including cooling) (B). “After heat treatment” refers to the amount of change in color tone between the color tone (A) before chemical strengthening treatment and the color tone (C) after chemical strengthening treatment, cooling and heat treatment.

Operation panel for AV equipment, OA equipment, etc., door of the same product, operation button, operation knob, decorative panel arranged around the rectangular display surface of image display panel such as digital photo frame, TV, etc. It can utilize suitably for what is called an exterior member for electronic devices, such as a decorative article and a glass housing | casing for electronic devices. It can also be used for interior parts for automobiles, members such as furniture, and building materials used outdoors and indoors.
The entire contents of the specification, claims, drawings, and abstract of Japanese Patent Application No. 2012-149861 filed on July 3, 2012 are incorporated herein as the disclosure of the present invention. .

Claims (11)

A glass production method characterized by cooling a temperature range from a chemical strengthening treatment temperature to 300 ° C. at a cooling rate of 30 ° C./min or more after chemically strengthening the glass containing a coloring component. 2. The method for producing glass according to claim 1, wherein the glass containing a coloring component is cooled at a cooling rate of 200 ° C./min or more after the temperature range from the temperature of the chemical strengthening treatment to 300 ° C. after the chemical strengthening treatment. . Measuring the amount of change in color of the glass before and after cooling the glass containing the coloring component at a cooling rate of 30 ° C./min. Formulating a glass raw material so as to obtain a glass composition determined based on a desired color tone and the expected change amount, a step of obtaining an expected change amount of the color tone of the glass due to chemical strengthening treatment and cooling based on the color tone change amount The method according to claim 1, comprising a step of melting and molding the obtained molten glass, a step of chemically strengthening the molded glass, and a step of cooling the chemically strengthened glass. The manufacturing method of the glass of description. The glass is heat-treated at a temperature within a range of (A-150) ° C to (A-50) ° C after the cooling, where A is a chemical strengthening treatment temperature in the chemical strengthening treatment. The method for producing glass according to 1 or 2. The chromaticity a ^* of the reflected light before chemical strengthening treatment by the L ^* a ^* b ^* color system (F2 light source) represented by the following formula (I), and the reflected light after chemical strengthening treatment, cooling and heat treatment The difference from the chromaticity a ^* is Δa ^* , the chromaticity b ^* of the reflected light before the chemical strengthening treatment by the L ^* a ^* b ^* color system (F2 light source) represented by the following formula (II), and the chemical strengthening When the difference from the chromaticity b ^* of the reflected light after treatment, cooling and heat treatment is Δb ^* , the color tone change amount represented by the following formula (III) is 0.6 or less. Item 5. A method for producing glass according to Item 4.
Δa ^* = a ^* value (before chemical strengthening treatment) −a ^* value (chemical strengthening treatment, after cooling and after heat treatment) (I)
Δb ^* = b ^* value (before chemical strengthening treatment) −b ^* value (after chemical strengthening treatment, after cooling and after heat treatment) (II)
√ ((Δa ^* ) ² + (Δb ^* ) ² ) (III) The method for producing glass according to claim 4 or 5, wherein the glass after the heat treatment has a reduction rate of the surface compressive stress of less than 25% as compared with the glass before the heat treatment. The glass is selected from the group consisting of Fe ₂ O ₃ , Co ₃ O ₄ , NiO, CuO, TiO ₂ , MnO, Cr ₂ O ₃ , V ₂ O ₅ , Bi ₂ O ₃ , and Se as a coloring component. The method for producing glass according to any one of claims 1 to 6, wherein at least one component is contained in an amount of 0.1 to 7% in terms of mole percentage based on oxide. The glass is expressed in terms of mole percentage on an oxide basis, SiO ₂ 55 to 80%, Al ₂ O ₃ 0 to 16%, B ₂ O ₃ 0 to 12%, Na ₂ O 5 to 20%, K ₂ O 0-8%, MgO 0-15%, CaO 0-15%, ΣRO (R represents Mg, Ca, Sr, Ba, Zn) 0-18%, ZrO ₂ 0 ˜1%, selected from the group consisting of coloring components (Fe ₂ O ₃ , Co ₃ O ₄ , NiO, CuO, TiO ₂ , MnO, Cr ₂ O ₃ , V ₂ O ₅ , Bi ₂ O ₃ , and Se) The glass raw material is prepared so as to contain 0.1 to 7% of at least one component), the glass raw material is melted, and the obtained molten glass is formed into glass. The manufacturing method of the glass of any one. The depth of the surface compressive stress layer on the surface of the glass obtained by the glass production method according to any one of claims 1 to 8 is 5 µm or more, and the surface compressive stress of the surface compressive stress layer is 300 MPa or more. A method for producing glass, characterized by performing chemical strengthening treatment. A chemically strengthened glass produced by the method for producing a glass according to any one of claims 1 to 9. The chemically strengthened glass according to claim 10, which is used for an exterior member.

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