WO2019151404A1 - Colored glass and method for producing same - Google Patents

Abstract

[Problem] To provide a colored glass having a large refractive index and a method for producing the same. [Solution] Glass that includes a portion having a refractive index nd of 1.75 or greater and a maximum visible light transmittance value of 50% or less at a thickness of 1.0 mm.

Description

Colored glass and method for producing the same

The present invention relates to a colored glass and a method for producing the same.

Since ancient times, materials with strong luster such as jewels have been widely used as ornaments. A material with a strong luster appears to shine because it reflects a lot of light on the surface. That is, a material having strong gloss has a high surface reflectance. Here, the greater the surface reflectance, the greater the refractive index. Therefore, a material with a high refractive index can have a strong gloss like a jewel.

There are many gemstones that have a strong luster in highly transparent gemstones such as diamond. On the other hand, there are few things which are colored and have a strong luster in jewelry with low transparency. However, even a material with low transparency has a high luster and is useful because of its high decorativeness. Furthermore, if it is a material which is excellent in processability and can be obtained at a lower cost than gemstones, its usefulness will be higher.

Glass is an example of a material that has a large refractive index, is superior to gemstones, has excellent processability, is inexpensive, and can be colored. A method for reducing the transmittance by coloring glass is disclosed in Patent Document 1. In Patent Document 1, P ₂ O ₅ -WO ₃ based _{glass, P 2 O 5 -Nb 2 O} 5 -based glass, the P ₂ O ₅ -TiO ₂ based glass, glass by exposure to a non-oxidizing atmosphere at a high temperature Is disclosed as colored. However, in Patent Document 1, even if the thickness is 2 mm, the transmittance of the glass is as low as about 60%. Accordingly, there is a need for glasses that are more colored, i.e., have lower transmittance.

JP 2002-201041 A

The present invention has been made in view of such circumstances, and an object thereof is to provide a colored glass having a large refractive index and a method for producing the same.

The gist of the present invention is as follows.
(1) Refractive index nd is 1.75 or more,
Glass including a portion where the maximum value of visible light transmittance is 50% or less in terms of a thickness of 1.0 mm.

(2) Refractive index nd is 1.75 or more,
Glass including a portion having a Ti ³⁺ content of 0.1 mass ppm or more.

(3) Refractive index nd is 1.75 or more,
Glass including a portion having an electric conductivity of 10 ⁻⁸ S / cm or more.

(4) The glass according to any one of (1) to (3), which is a phosphate glass.

(5) The glass according to any one of (1) to (4), which contains 1 cation% or more of Nb ions as a glass component.

(6) The glass according to any one of (1) to (5), which contains 0.5 ion% or more of Ti ions as a glass component.

(7) The glass according to any one of (1) to (6), which contains a total of 0.1 cation% or more of Li ⁺ and Na ⁺ as glass components.

(8) The glass according to any one of (1) to (7), having an average linear expansion coefficient of 50 × 10 ⁻⁷ K ⁻¹ or more.

(9) The glass according to any one of (1) to (8), wherein the acid resistance based on JOGIS is grade 1.

(10) The glass according to any one of (1) to (9), comprising a crystallized portion.

(11) The glass according to any one of (1) to (10), comprising a chemically strengthened portion.

(12) A composite glass comprising any one or both of a metal material and ceramics and the glass according to any one of (1) to (11).

(13) including a step of heat-treating the molded glass in a reducing atmosphere,
A method for producing glass comprising a portion having a refractive index nd of 1.75 or more and a maximum visible light transmittance of 50% or less in terms of a thickness of 1.0 mm.

(14) including a step of obtaining molten glass in a reducing atmosphere,
A method for producing glass comprising a portion having a refractive index nd of 1.75 or more and a maximum visible light transmittance of 50% or less in terms of a thickness of 1.0 mm.

(15) including a step of adding water vapor to the melting atmosphere;
A method for producing glass comprising a portion having a refractive index nd of 1.75 or more and a maximum visible light transmittance of 50% or less in terms of a thickness of 1.0 mm.

1 shows an example of transmittance at a wavelength of 400 to 760 nm for a glass according to an embodiment of the present invention. 1 shows an example of transmittance at a wavelength of 400 to 760 nm for a glass according to an embodiment of the present invention. 1 shows an example of transmittance at a wavelength of 400 to 760 nm for a glass according to an embodiment of the present invention. 1 shows an example of transmittance at a wavelength of 400 to 760 nm for a glass according to an embodiment of the present invention. 1 shows an example of transmittance at a wavelength of 400 to 2500 nm for a glass according to an embodiment of the present invention. The graph shows, in order from the top, no atmosphere control in the melting process (Comparative Example 4-1), 0.1 wt% alcohol added (Example 4-1), 0.3 wt% alcohol added (Example 4-2), 0 The case of adding 5 wt% alcohol (Example 4-3) and 5 wt% alcohol (Example 4-4) is shown. In embodiment of this invention, an example of the apparatus for applying a voltage to glass is shown with the schematic diagram. In the glass which concerns on embodiment of this invention, an example at the time of partially decoloring is shown. In the glass which concerns on embodiment of this invention, an example of the transmittance | permeability of a decoloring part and a non-decoloring part is shown. The solid line graph shows, in order from the top, after decolorization (decolorization part) and before decolorization (non-decoloration part). In the glass which concerns on embodiment of this invention, an example of the cross section of the boundary of a decoloring part and a non-decoloring part is shown with the photograph. It is the transmittance | permeability curve in the visible light region of the glass which concerns on embodiment of this invention. It is the transmittance | permeability curve in the visible light region of the glass which concerns on embodiment of this invention. It is the transmittance | permeability curve in the visible light region of the glass which concerns on embodiment of this invention. It is the transmittance | permeability curve in the visible light region of the glass which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail. In the present embodiment, the glass according to the present invention will be described based on the content ratio of each component in terms of cation%. Therefore, hereinafter, unless otherwise specified, “%” means “cation%”.

The cation% display means a mole percentage when the total content of all cation components is 100%. The total content refers to the total amount of the contents of a plurality of types of cation components (including the case where the content is 0%). The cation ratio refers to the ratio (ratio) of the content of cation components (including the total content of plural types of cation components) in cation% display.

The content of the glass component can be quantified by a known method such as inductively coupled plasma emission spectroscopy (ICP-AES) or inductively coupled plasma mass spectrometry (ICP-MS). Further, in the present specification and the present invention, the content of the constituent component of 0% means that the constituent component is substantially not included, and the component is allowed to be included at an unavoidable impurity level.

In addition, in this specification, the refractive index means the refractive index nd of helium d-line (wavelength 587.56 nm) unless otherwise specified.

Hereinafter, the present invention will be described as a first embodiment, a second embodiment, a third embodiment, and a fourth embodiment. In addition, the characteristic of the glass in 2nd, 3rd, 4th embodiment is common in the characteristic of the glass in 1st Embodiment. Moreover, the effect | action and effect of each glass component in 2nd, 3rd, 4th embodiment are the same as the effect | action and effect of each glass component in 1st Embodiment. Accordingly, in the second, third, and fourth embodiments, matters that overlap with the description related to the first embodiment are omitted as appropriate.

First Embodiment The glass according to the first embodiment is
Refractive index nd is 1.75 or more,
It includes a portion where the maximum value of visible light transmittance is 50% or less in terms of thickness 1.0 mm.

(Refractive index)
In the glass according to the first embodiment, the refractive index nd is 1.75 or more. Preferably it is 1.76 or more, and more preferably in the order of 1.77 or more, 1.78 or more, 1.79 or more, 1.80 or more. The upper limit of the refractive index nd is not particularly limited, but is usually 2.50, preferably 2.30. In the present embodiment, the refractive index nd may be measured as it is, or may be measured after reducing the coloring of the glass. As a method for reducing coloring, for example, a method of applying a voltage, which will be described later, and a heat treatment are exemplified. As a method for reducing the coloration of the glass by the heat treatment, there is a method in which the glass is heated in the vicinity of Tg for several hours to several tens of hours in the air atmosphere.

(Transmittance)
The glass according to the first embodiment includes a colored portion, and specifically includes a portion where the maximum value of the transmittance of visible light when converted to a thickness of 1.0 mm is 50% or less. The glass according to the present embodiment includes a portion where the maximum value of the transmittance of visible light is preferably 40% or less in terms of a thickness of 1.0 mm, and the maximum value of the transmittance is 30% or less, 20 % Or less, 10% or less, 5% or less, 2% or less, or 1% or less may be included. The maximum value of visible light transmittance may be 0%. The region in which the maximum value of the visible light transmittance is in the above range in terms of the thickness of 1.0 mm may be a part or all of the glass. Visible light is light having a wavelength in the range of 400 to 760 nm.

Further, the glass according to the first embodiment includes a portion where the transmittance at a wavelength of 1100 nm when converted to a thickness of 1.0 mm is preferably 80% or less, and the transmittance at a wavelength of 1100 nm is 70% or less. 60% or less, 50% or less, 45% or less, 40% or less, 35% or less, 30% or less, 25% or less, 20% or less, 15% or less, 10% or less, 5% or less, 3% or less, 1% Hereinafter, a portion that is 0.5% or less, 0.3% or less, 0.1% or less, 0.05% or less, or 0.03% or less may be included. The region where the transmittance at a wavelength of 1100 nm when converted to a thickness of 1.0 mm is in the above range may be a part or all of the glass.

In the glass according to the first embodiment, in the colored portion, that is, the portion where the maximum value of the visible light transmittance is 50% or less in terms of the thickness of 1.0 mm, and the other portion, the glass component composition is The same. Moreover, the glass component composition is the same also in a colored part and the part which applied the voltage and decolored by the method mentioned later. However, the valence of the glass component (cation) may be different between the colored portion and the other portion. Similarly, the valence of the glass component (cation) may be different between the colored portion and the decolored portion. The same applies to a portion where the transmittance at a wavelength of 1100 nm is 80% or less in terms of a thickness of 1.0 mm and other portions.

Hereinafter, the glass according to the first embodiment will be described in detail.

(Ti ³⁺ content)
The glass according to the first embodiment preferably includes a portion where the content of Ti ³⁺ is 0.1 mass ppm or more, and the content of Ti ³⁺ is 0.3 mass ppm or more, 0.5 mass ppm or more, A portion that is 1 mass ppm or more, 5 mass ppm or more, 15 mass ppm or more, 25 mass ppm or more, 50 mass ppm or more, 70 mass ppm or more, or 90 mass ppm or more may be included. The upper limit of Ti ³⁺ is not particularly limited, but is usually 10,000 ppm by mass, preferably 5000 ppm by mass. The region where the content of Ti ³⁺ is in the above range may be a part or all of the glass. The content of Ti ³⁺ can be measured by ESR (electron spin resonance method).

In the glass according to the first embodiment, the coloring is preferably a reduced color caused by a glass component, and more preferably a reduced color caused by a transition metal. Examples of the transition metal include Ti, Nb, Bi, and W.

The glass is colored according to the valence of these transition metals. For example, in Ti contained as a glass component, when tetravalent Ti ⁴⁺ is reduced to trivalent Ti ³⁺ , the glass is colored. Similarly, when Nb, Bi, and W are reduced to change their valence, the glass is colored.

Therefore, in the glass according to the present embodiment, a part of tetravalent Ti ⁴⁺ is reduced to become trivalent Ti ³⁺ is colored, that is, converted into a thickness of 1.0 mm. The maximum value of visible light transmittance can be 50% or less. And the grade of coloring in the part can be ^raised by making content of Ti3 ⁺ into the said range.

(Electrical conductivity)
The glass according to the first embodiment includes a portion having conductivity, preferably includes a portion having an electric conductivity of 10 ⁻⁸ S / cm or more, and an electric conductivity of 10 ⁻⁷ S / cm or more. ⁻⁶ S / cm or more, 10 ⁻⁵ S / cm or more, 5 × 10 ⁻⁵ S / cm or more, 10 ⁻⁴ S / cm or more, 5 × 10 ⁻⁴ S / cm or more, 10 ⁻³ S / cm or more A portion that is 5 × 10 ⁻³ S / cm or more, or 10 ⁻² S / cm or more may be included. The upper limit of the electrical conductivity is not particularly limited, but is usually 10 ² S / cm, preferably 1 S / cm. The region where the electric conductivity is in the above range may be a part or all of the glass. The electrical conductivity can be measured by, for example, an AC impedance method. The measurement temperature of the electrical conductivity is set to a temperature that is 200 ° C. lower than the glass transition temperature Tg (Tg−200 ° C.) or higher and lower than the glass transition temperature Tg.

In the glass according to the first embodiment, the conductive portion is colored, that is, the maximum value of visible light transmittance can be 50% or less in terms of a thickness of 1.0 mm. Reducing the color of the glass decreases the electrical conductivity, and increasing the color increases the electrical conductivity. Therefore, adjusting either the coloration or the electrical conductivity of the glass can also adjust the other. For example, the coloring of the glass can be adjusted, and the electric conductivity can be within the above range.

Moreover, in the glass according to the first embodiment, coloring can be reduced by applying a voltage to the glass under certain conditions and oxidizing the glass component by ion conduction. That is, by applying a voltage to the colored portion of the glass under a certain condition, the visible light transmittance in that portion can be increased.

Specifically, the transmittance of the colored portion can be increased by applying a voltage in a state where the glass according to the first embodiment is heated to the glass yield point Ts or lower.

In particular, the glass according to the first embodiment has a thickness of 1.0 mm in the atmospheric air at a temperature range of 200 ° C. lower than the glass transition temperature Tg (Tg−200 ° C.) to the softening point. When the electrode is brought into contact with the polished glass in the thickness direction and a voltage is applied under the conditions of a voltage of 20 kv or less and a processing time of 5 hours or less, the maximum transmittance at a wavelength of 400 to 760 nm is measured before and after the application of electricity. The amount of change can be 10% or more.

In the above processing, it is possible to decolorize in a pattern by applying a voltage partially.

In the glass according to this embodiment, the range of the glass transition temperature Tg is preferably 350 to 850 ° C., and further 370 to 830 ° C., 380 to 800 ° C., 400 to 770 ° C., 420 to 740 ° C., 440 It is more preferable in the order of ˜710 ° C. and 440 to 680 ° C.

(Average linear expansion coefficient)
In the glass according to the first embodiment, the average linear expansion coefficient is preferably 50 × 10 ⁻⁷ K ⁻¹ or more, more preferably 60 × 10 ⁻⁷ K ⁻¹ or more, or 70 × 10 ⁻⁷ K ^−1. More preferably, the order is 75 × 10 ⁻⁷ K ⁻¹ or more, 80 × 10 ⁻⁷ K ⁻¹ or more, 85 × 10 ⁻⁷ K ⁻¹ or more, and 90 × 10 ⁻⁷ K ⁻¹ or more. The upper limit of the average linear expansion coefficient is not particularly limited, but is usually 200 × 10 ⁻⁷ K ⁻¹ and preferably 150 × 10 ⁻⁷ K ⁻¹ . By setting the average linear expansion coefficient in the above range, the strength of the glass can be increased when chemical strengthening described later is performed.

The measurement method of the average linear expansion coefficient follows the Japan Optical Glass Industry Association Standard JOGIS 08-2003 “Measurement Method of Thermal Expansion of Optical Glass”. However, the diameter of the round bar-shaped sample is 5 mm.

(Acid resistance weight reduction rate Da)
In the glass according to the first embodiment, the acid resistance weight reduction rate Da is preferably 1 to 2, more preferably 1 grade.

The acid-resistant weight reduction rate Da is measured according to the specifications of Japan Optical Glass Industry Association Standard JOGIS06-2009. Specifically, powder glass (particle size: 425 to 600 μm) having a weight corresponding to the specific gravity is placed in a platinum basket and immersed in a quartz glass round bottom flask containing a 0.01 mol / L nitric acid aqueous solution. The sample is treated for 60 minutes, and the weight loss rate (%) before and after the treatment is measured. Table A shows the grade based on the acid-resistant weight loss rate Da.

(ΒOH)
In the glass according to the first embodiment, the lower limit of the value of βOH represented by the following formula (1) is preferably 0.3 mm ⁻¹ , and further, 0.4 mm ⁻¹ , 0.5 mm ⁻¹ , ^{0.6mm -1, 0.7mm -1, 0.8mm -1} , 0.9mm -1, 1.0mm -1, 1.05mm -1, 1.1mm -1, in the order of 1.15 mm ^-1 preferable. Further, the upper limit of the value of βOH is preferably 4.5 mm ⁻¹ , and 4.0 mm ⁻¹ , 3.8 mm ⁻¹ , 3.5 mm ⁻¹ , 3.0 mm ⁻¹ , 2.5 mm ^{− 1} , 2.3 mm ⁻¹ , 2.2 mm ⁻¹ , 2.1 mm ⁻¹ , 2.0 mm ⁻¹ are more preferable in this order.

βOH = − [ln (B / A)] / t (1)
Here, in the above formula (1), t represents the thickness (mm) of the glass used for measuring the external transmittance, and A represents a wavelength of 2500 nm when light is incident on the glass in parallel with the thickness direction. Represents the external transmittance (%), and B represents the external transmittance (%) at a wavelength of 2900 nm when light is incident on the glass in parallel to the thickness direction. In is a natural logarithm. The unit of βOH is mm ⁻¹ .

The “external transmittance” is the ratio (Iout / Iin) of the intensity Iout of the transmitted light transmitted through the glass to the intensity Iin of the incident light incident on the glass, that is, the transmittance considering the surface reflection on the surface of the glass. It is. The transmittance is obtained by measuring a transmission spectrum using a spectrophotometer. As a spectroscopic device, “UV-3100 (Shimadzu)” can be used. The external transmittance may be measured as it is or after the coloring of the glass is reduced. As a method for reducing coloring, for example, a method of applying a voltage, which will be described later, and a heat treatment are exemplified. As a method for reducing the coloration of the glass by heat treatment, there is a method in which the glass is heated in the vicinity of Tg for several hours to several tens of hours in the air atmosphere.

ΒOH represented by the above formula (1) is defined on the basis that the transmittance changes due to the absorption of light caused by the hydroxyl group. Therefore, by evaluating βOH, the concentration of water (and / or hydroxide ions) contained in the glass can be evaluated. That is, a glass having a high βOH means that the concentration of water (and / or hydroxide ions) contained in the glass is high.

In order to reduce the coloring of the glass, when a voltage is applied to the glass or when the glass is heat-treated, the application time or heat treatment time can be shortened by setting the βOH value within the above range. On the other hand, if the value of βOH is too large, the transition metal ion component contained in the glass tends to precipitate as a metal. Moreover, there exists a possibility that the amount of volatiles from molten glass may increase at the time of glass melting.

(Color)
The glass according to the first embodiment can change the color of the glass by adjusting the external transmittance in the visible light region (wavelength 400 to 760 nm). Specifically, by adjusting the transmittance curve of glass (the horizontal axis is the wavelength in the visible light region (wavelength 400 to 760 nm) and the vertical axis is the external transmittance), the glass has a shape having predetermined characteristics. The color of the glass can be changed.

For example, in order to obtain a glass having a bluish color or a bluish black color, the transmittance curve in the visible light region (wavelength 400 to 760 nm) may have the following characteristics. That is, 1) a maximum value in the wavelength range of 400 to 450 nm and the transmittance at a wavelength of 400 nm is larger than the transmittance at a wavelength of 760 nm, or 2) the transmittance does not have a maximum value and a minimum value. The maximum value is in the wavelength range of 400 to 450 nm.

Further, in order to obtain reddish glass or reddish black glass, the transmittance curve in the visible light region (wavelength 400 to 760 nm) does not have the maximum value and the minimum value, and the maximum value of the transmittance. May be in the wavelength range of 700 to 760 nm.

Furthermore, in order to obtain reddish-purple glass or reddish-purple black glass, the transmittance curve in the visible light region (wavelength 400 to 760 nm) has a minimum value in the wavelength range 450 to 550 nm. In addition, the transmittance at a wavelength of 400 nm may be made smaller than the transmittance at a wavelength of 760 nm.

Here, the maximum value is a point where the external transmittance changes from an increase to a decrease in the transmittance curve, and the minimum value is a point where the external transmittance changes from a decrease to an increase in the transmittance curve. The maximum value of the transmittance is the maximum value of the external transmittance in the visible light region (wavelength 400 to 760 nm).

(Glass composition)
Non-limiting examples of the glass composition of the glass according to the first embodiment are shown below.

The glass according to the first embodiment is preferably phosphate glass. The phosphate glass refers to a glass mainly containing P ⁵⁺ as a glass network forming component. P ⁵⁺ , B ³⁺ , Si ⁴⁺ , Al ^{3+ and the} like are known as glass network forming components. Here, the phrase “mainly including phosphate as a network-forming component of glass” means that the content of P ⁵⁺ is larger than any content of B ³⁺ , Si ⁴⁺ , and Al ³⁺ . By being phosphate glass, the degree of coloring of the glass can be increased.

In the glass according to the first embodiment, the lower limit of the content of P ⁵⁺ is preferably 10%, and more preferably in the order of 13%, 15%, 17%, and 20%. Further, the upper limit of the content of P ⁵⁺ is preferably 50%, and more preferably in the order of 45%, 43%, 40%, 38%, and 35%.

P ⁵⁺ is a glass network-forming component and has a function of maintaining the thermal stability of the glass. On the other hand, if P ⁵⁺ is contained excessively, the ^meltability deteriorates. Therefore, the content of P ⁵⁺ is preferably in the above range.

In the glass according to the first embodiment, the upper limit of the content of B ³⁺ is preferably 35%, and more preferably 30%, 25%, 20%, 15%, 13%, and 10%. Further, the lower limit of the content of B ³⁺ is preferably 0%, and more preferably 0.1%, 0.3%, 0.5%, 1%, 3%, and 5%. The content of B ³⁺ may be 0%.

B ³⁺ is a glass network-forming component and has a function of improving the meltability of the glass. On the other hand, when there is too much content of ^{B3 +} , there exists a tendency for chemical durability to fall. Therefore, the content of B ³⁺ is preferably in the above range.

In the glass according to the first embodiment, the upper limit of the cation ratio [B ³⁺ / P ⁵⁺ ] of the B ³⁺ content to the P ⁵⁺ content is preferably 0.95, and further 0.93, 0. It is more preferable in order of 9, 0.8, 0.7, 0.6, 0.55, 0.5. The cation ratio [B ³⁺ / P ⁵⁺ ] may be zero.

In the glass according to the first embodiment, the upper limit of the content of Si ⁴⁺ is preferably 10%, and more preferably in the order of 7%, 5%, 3%, 2%, and 1%. The content of Si ⁴⁺ may be 0%.

Si ⁴⁺ is a network-forming component of glass, and has a function of improving the thermal stability, chemical durability, and weather resistance of glass. On the other hand, when there is too much content of ^{Si4 +} , the meltability of glass will fall and there exists a tendency for a glass raw material to remain unmelted. Therefore, the content of Si ⁴⁺ is preferably in the above range.

In the glass according to the first embodiment, the upper limit of the content of Al ³⁺ is preferably 10%, and more preferably in the order of 7%, 5%, 3%, and 1%. The content of Al ³⁺ may be 0%.

Al ³⁺ has a function of improving the chemical durability and weather resistance of glass. On the other hand, when the content of Al ³⁺ is too large, the refractive index decreases, the thermal stability of the glass decreases, the glass transition temperature Tg increases, and the meltability tends to decrease. Therefore, the content of Al ³⁺ is preferably in the above range.

In the glass according to the first embodiment, the lower limit of the total content [P ⁵⁺ + B ³⁺ + Si ⁴⁺ + Al ³⁺ ] of P ⁵⁺ , B ³⁺ , Si ⁴⁺ and Al ³⁺ is preferably 10%, and further 15%, 18%, 20%, 23%, and 25% are more preferable in this order. Further, the upper limit of the total content [P ⁵⁺ + B ³⁺ + Si ⁴⁺ + Al ³⁺ ] is preferably 60%, and more preferably 55%, 53%, 50%, 45%, 40%, and 37%.

The glass according to the first embodiment preferably has a transition metal as a glass component, and more preferably at least one glass component selected from the group consisting of Ti ⁴⁺ , Nb ⁵⁺ , Bi ³⁺ and W ^{6+ in} cation display. More preferably, Ti ⁴⁺ is contained.

In the glass according to the first embodiment, the lower limit of the content of Ti ions is preferably 0.1%, and further in the order of 0.5%, 1%, 1.5%, 2%, 3%. preferable. Further, the upper limit of the Ti ion content is preferably 45%, and more preferably 40%, 38%, 35%, 33%, and 30% in this order. Here, the Ti ions include all Ti ions having different valences in addition to Ti ⁴⁺ and Ti ³⁺ .

Ti ions, like Nb ions, W ions, and Bi ions, greatly contribute to increasing the refractive index and have a function of increasing the coloring of the glass. On the other hand, when there is too much content of Ti ion, the meltability of glass will fall and there exists a tendency for a glass raw material to remain unmelted. Therefore, the Ti ion content is preferably in the above range.

In the glass according to the first embodiment, the lower limit of the Nb ion content is preferably 0.1%, and further 0.5%, 1%, 5%, 10%, 13%, 15%, 17 % Order is more preferable. The upper limit of the Nb ion content is preferably 50%, and more preferably in the order of 45%, 43%, 40%, and 38%. Nb ions include all Nb ions having different valences in addition to Nb ⁵⁺ .

Nb ions are components that contribute to a higher refractive index and increase the coloration of the glass. It also has the function of improving the thermal stability and chemical durability of the glass. On the other hand, when there is too much content of Nb ion, there exists a tendency for the thermal stability of glass to fall. Therefore, the content of Nb ions is preferably in the above range.

In the glass according to the first embodiment, the upper limit of the W ion content is preferably 30%, and more preferably in the order of 25%, 20%, 15%, and 13%. The content of W ions may be 0%. W ions include all W ions having different valences in addition to W ⁶⁺ .

W ions contribute to a higher refractive index and have a function of increasing the coloring of the glass. On the other hand, when there is too much content of W ion, there exists a tendency for the thermal stability of glass to fall. Therefore, the content of W ions is preferably in the above range.

In the glass according to the first embodiment, the upper limit of the Bi ion content is preferably 35%, and more preferably 30%, 28%, and 25%. The content of Bi ions may be 0%. Bi ions include all Bi ions having different valences in addition to Bi ³⁺ .

Bi ions contribute to a higher refractive index and have a function of increasing the coloration of the glass. Bi ions have the effect of increasing the expansion of the glass. On the other hand, when there is too much content of Bi ion, there exists a tendency for the thermal stability of glass to fall. Therefore, the content of Bi ions is preferably in the above range.

In the glass according to the first embodiment, the lower limit of the total content [Ti + Nb + W] of Ti ions, Nb ions, and W ions is preferably 0.1%, and further 0.5%, 1%, 3%, 5%, 10%, 15%, 20% and 22% are more preferable in this order. The upper limit of the total content [Ti + Nb + W] is preferably 75%, and more preferably in the order of 70%, 65%, 63%, 60%, 58%.

In the glass according to the first embodiment, the lower limit of the total content [Ti + Nb + W + Bi] of Ti ions, Nb ions, W ions and Bi ions is preferably 0.1%, and further 0.5%, 1%, 3%, 5%, 10%, 15%, 20%, 22%, and 25% are more preferable in this order. Further, the upper limit of the total content [Ti + Nb + W + Bi] is preferably 80%, and more preferably in the order of 75%, 73%, 70%, and 67%.

In the glass according to the first embodiment, the upper limit of the Ta ⁵⁺ content is preferably 5%, and more preferably 3%, 2%, and 1%. The content of Ta ⁵⁺ may be 0%.

Ta ⁵⁺ has a function of improving the thermal stability of the glass. On the other hand, when the content of Ta ⁵⁺ is too large, the glass tends to have a low refractive index, and the meltability tends to decrease. Therefore, the content of Ta ⁵⁺ is preferably in the above range.

In the glass according to the first embodiment, the cation ratio of the total content of Ti ions, Nb ions, W ions and Bi ions to the total content of P ⁵⁺ , B ³⁺ and Si ⁴⁺ [(Ti + Nb + W + Bi) / (P ⁵⁺ + B ³⁺ + Si ⁴⁺ )] is preferably 0.1, and more preferably 0.3, 0.4, 0.5, 0.55, 0.6, 0.7. Further, the upper limit of the cation ratio [(Ti + Nb + W + Bi) / (P ⁵⁺ + B ³⁺ + Si ⁴⁺ )] is preferably 8, and more preferably in the order of 5, ^{4, 3} , 2.7, and 2.5.

The glass according to the first embodiment preferably contains one or both of Li ⁺ and Na ⁺ as a glass component, and more preferably contains 0.1% or more of Li ⁺ and Na ⁺ in total. When glass contains Li ⁺ or Na ⁺ , chemical strengthening described later can be performed.

In the glass according to the first embodiment, the upper limit of the Li ⁺ content is preferably 35%, and more preferably in the order of 30%, 27%, 25%, 22%, and 20%. Moreover, the lower limit of the content of Li ⁺ is preferably 0.1%, and more preferably in the order of 0.5%, 1%, 3%, 5%, 10%, and 15%. The content of Li ⁺ may be 0%.

In the glass according to the first embodiment, the upper limit of the content of Na ⁺ is preferably 45%, and more preferably in the order of 40%, 38%, 35%, and 33%. Further, the lower limit of the content of Na ⁺ is preferably 0.1%, and further in the order of 0.5%, 1%, 3%, 5%, 10%, 13%, 15%, and 17%. preferable. The content of Na ⁺ may be 0%.

When the glass contains Li ⁺ or Na ⁺ , chemical strengthening described later can be applied to the glass. On the other hand, when there is too much content of Li ^<+> or Na ^<+> , there exists a possibility that the thermal stability of glass may fall. Therefore, each content of Li ⁺ and Na ⁺ is preferably in the above range.

In the glass according to the first embodiment, the upper limit of the content of K ⁺ is preferably 30%, and more preferably in the order of 25%, 23%, 20%, 17%, and 15%. Further, the lower limit of the content of K ⁺ is preferably 0.1%, and more preferably 0.3%, 0.5%, and 1%. The content of K ⁺ may be 0%.

K ⁺ has a function of improving the thermal stability of the glass. On the other hand, when the content of K ⁺ is too large, the thermal stability tends to decrease. Therefore, the K ⁺ content is preferably in the above range.

In the glass according to the first embodiment, the upper limit of the total content [Li ⁺ + Na ⁺ ] of Li ⁺ and Na ⁺ is preferably 50%, and further in the order of 45%, 43%, 40%, and 38%. Is more preferable. Further, the lower limit of the total content [Li ⁺ + Na ⁺ ] is preferably 0.1% and 0.5%, and more preferably in the order of 1%, 5%, 10%, 13% and 15%.

In the glass according to the first embodiment, the upper limit of the content of Rb ⁺ is preferably 5%, and more preferably in the order of 3%, 1%, and 0.5%. The content of Rb ⁺ may be 0%.

In the glass according to the first embodiment, the upper limit of the content of Cs ⁺ is preferably 5%, and more preferably 3%, 1%, and 0.5%. The content of Cs ⁺ may be 0%.

Rb ⁺ and Cs ⁺ have a function of improving the meltability of the glass. On the other hand, if the content is too large, the refractive index nd decreases, and the volatilization of the glass component may increase during melting. Therefore, each content of Rb ⁺ and Cs ⁺ is preferably in the above range.

In the glass according to the first embodiment, the upper limit of the Mg ²⁺ content is preferably 15%, and more preferably in the order of 10%, 5%, 3%, and 1%. The content of Mg ²⁺ may be 0%.

In the glass according to the first embodiment, the upper limit of the content of Ca ²⁺ is preferably 15%, and more preferably in the order of 10%, 5%, 3%, and 1%. The content of Ca ²⁺ may be 0%.

In the glass according to the first embodiment, the upper limit of the Sr ²⁺ content is preferably 15%, and more preferably in the order of 10%, 5%, 3%, and 1%. The Sr ²⁺ content may be 0%.

In the glass according to the first embodiment, the upper limit of the Ba ²⁺ content is preferably 20%, and more preferably 15%, 10%, and 5%. The content of Ba ²⁺ may be 0%.

Mg ²⁺ , Ca ²⁺ , Sr ²⁺ and Ba ²⁺ all have a function of improving the thermal stability and meltability of the glass. Ba ²⁺ has the effect of increasing the expansion of the glass. On the other hand, if the content is too large, the high refractive index property is impaired, and the thermal stability of the glass may be lowered. Therefore, it is preferable that each content of these glass components is the said range, respectively.

In the glass according to the first embodiment, the upper limit of the total content [Mg ²⁺ + Ca ²⁺ + Sr ²⁺ + Ba ²⁺ ] of Mg ²⁺ , Ca ²⁺ , Sr ²⁺ and Ba ²⁺ is preferably 30%, and further 25%, 20%, 18%, 15%, 10%, 5%, 3%, and 1% are more preferable in this order. The total content [Mg ²⁺ + Ca ²⁺ + Sr ²⁺ + Ba ²⁺ ] may be 0%.

In the glass according to the first embodiment, the upper limit of the Zn ²⁺ content is preferably 15%, and more preferably in the order of 10%, 8%, 5%, 3%, and 1.5%. The content of Zn ²⁺ may be 0%.

Zn ²⁺ has a function of improving the thermal stability of the glass. On the other hand, when there is too much content of Zn2 ⁺ , there exists a possibility that a meltability may deteriorate. Therefore, the Zn ²⁺ content is preferably in the above range.

In the glass according to the first embodiment, the upper limit of the content of Zr ⁴⁺ is preferably 5%, and more preferably 3%, 2%, and 1%. The content of Zr ⁴⁺ may be 0%.

Zr ⁴⁺ has a function of improving the thermal stability of the glass. On the other hand, when there is too much content of Zr4 ⁺ , there exists a tendency for the thermal stability and meltability of glass to fall. Therefore, the content of Zr ⁴⁺ is preferably in the above range.

In the glass according to the first embodiment, the upper limit of the content of Ga ³⁺ is preferably 3%, and more preferably in the order of 2% and 1%. The lower limit of the Ga ³⁺ content is preferably 0%. The content of Ga ³⁺ may be 0%.

In the glass according to the first embodiment, the upper limit of the content of In ³⁺ is preferably 3%, and more preferably in the order of 2% and 1%. Moreover, the lower limit of the content of In ³⁺ is preferably 0%. The content of In ³⁺ may be 0%.

In the glass according to the first embodiment, the upper limit of the content of Sc ³⁺ is preferably 3%, and more preferably in the order of 2% and 1%. Moreover, the lower limit of the content of Sc ³⁺ is preferably 0%. The content of Sc ³⁺ may be 0%.

In the glass according to the first embodiment, the upper limit of the content of Hf ⁴⁺ is preferably 3%, more preferably 2% and 1%. Further, the lower limit of the content of Hf ⁴⁺ is preferably 0%. The content of Hf ⁴⁺ may be 0%.

In the glass according to the first embodiment, the upper limit of the content of Lu ³⁺ is preferably 3%, and more preferably in the order of 2% and 1%. Further, the lower limit of the content of Lu ³⁺ is preferably 0%. The Lu ³⁺ content may be 0%.

In the glass according to the first embodiment, the upper limit of the content of Ge ⁴⁺ is preferably 3%, and more preferably in the order of 2% and 1%. Further, the lower limit of the content of Ge ⁴⁺ is preferably 0%. The content of Ge ⁴⁺ may be 0%.

In the glass according to the first embodiment, the upper limit of the La ³⁺ content is preferably 5%, and more preferably in the order of 4%, 3%, 2%, and 1%. Moreover, the lower limit of the content of La ³⁺ is preferably 0%. The La ³⁺ content may be 0%.

In the glass according to the first embodiment, the upper limit of the content of Gd ³⁺ is preferably 5%, and more preferably in the order of 4%, 3%, 2%, and 1%. Further, the lower limit of the content of Gd ³⁺ is preferably 0%. The content of Gd ³⁺ may be 0%.

In the glass according to the first embodiment, the upper limit of the content of Y ³⁺ is preferably 5%, and more preferably 4%, 3%, 2%, and 1%. Moreover, the lower limit of the content of Y ³⁺ is preferably 0%. The content of Y ³⁺ may be 0%.

In the glass according to the first embodiment, the upper limit of the content of Yb ³⁺ is preferably 5%, and more preferably 4%, 3%, 2%, and 1%. Moreover, the lower limit of the content of Yb ³⁺ is preferably 0%. The content of Yb ³⁺ may be 0%.

The cation component of the glass according to the first embodiment is mainly the above-mentioned components, that is, P ⁵⁺ , B ³⁺ , Si ⁴⁺ , Al ³⁺ , Ti ion, Nb ion, W ion, Bi ion, Ta ⁵⁺ , Li ⁺ , Na ^{+, K +, Rb +,} Cs +, Mg 2+, Ca 2+, Sr 2+, Ba 2+, Zn 2+, Zr 4+, Ga 3+, In 3+, Sc 3+, Hf 4+, Lu 3+, Ge 4+, La 3+, It is preferably composed of Gd ³⁺ , Y ³⁺ and Yb ³⁺ , and the total content of the above-mentioned components is preferably more than 95%, more preferably more than 98%, more than 99% Is more preferable, and it is more preferable to increase it to more than 99.5%.

Glass according to the first embodiment, as an anionic component, F ^- may include and O ^2- other components. Examples of the anion component other than F ⁻ and O ²⁻ include Cl ⁻ , Br ⁻ and I ⁻ . However, Cl ⁻ , Br ⁻ and I ⁻ are all volatile during melting of the glass. Volatilization of these components causes problems such as fluctuations in glass characteristics, deterioration in glass homogeneity, and significant consumption of melting equipment. Therefore, Cl ^- content of preferably less than 5 anionic%, more preferably less than 3 anionic%, more preferably less than 1 anionic%, particularly preferably less than 0.5 anionic%, more preferably 0. Less than 25 anion%. Further, Br ^- and I ^- the total content of preferably less than 5 anionic%, more preferably less than 3 anionic%, more preferably less than 1 anionic%, particularly preferably less than 0.5 anionic%, more Preferably it is less than 0.1 anion%, and more preferably 0 anion%.

In addition, anion% is a mole percentage when the total content of all anion components is 100%.

The glass according to the first embodiment is preferably basically composed of the above components, but may contain other components as long as the effects of the present invention are not hindered.

For example, the glass according to the first embodiment may further contain an appropriate amount of copper (Cu) as a glass component in order to impart near infrared light absorption characteristics to the glass. In addition, V, Cr, Mn, Fe, Co, Ni, Pr, Nd, Pm, Sm, Eu, Tb, Dy, Ho, Er, Tm, Ce, and the like may be contained. These increase the coloration of the glass and can be a source of fluorescence.

In the present invention, the inclusion of inevitable impurities is not excluded.

<Other component composition>
Pb, As, Cd, Tl, Be and Se are all toxic. Therefore, it is preferable that the glass of 1st Embodiment does not contain these elements as a glass component.

U, Th, and Ra are all radioactive elements. Therefore, it is preferable that the glass of 1st Embodiment does not contain these elements as a glass component.

Sb ₂ O ₃ , SnO ₂ , and CeO ₂ are optional glass components that function as fining agents. Among these, Sb ³⁺ is a fining agent having a large fining effect.

The content of Sb ₂ O ₃ is displayed on an external basis. That is, the content of Sb ₂ O ₃ is preferably 2% by mass when the total content of all glass components other than Sb ₂ O ₃ , SnO _2, and CeO ₂ is 100% by mass in terms of oxides. Less than, more preferably less than 1% by weight, even more preferably less than 0.5% by weight, even more preferably less than 0.3% by weight, and particularly preferably less than 0.2% by weight. Content of Sb ₂ O ₃ may be 0 mass%. By setting the content of Sb ₂ O _{3 in} the above range, the clarity of the glass can be improved.

Each content of SnO ₂ and CeO ₂ is also set as an outside display. That is, each content of SnO ₂ and CeO ₂ when the total content of all glass components other than Sb ₂ O ₃ , SnO _2, and CeO ₂ is 100% by mass in terms of oxide is preferably 2 Less than 1% by mass, more preferably less than 1% by mass, still more preferably less than 0.5% by mass, and even more preferably less than 0.1% by mass. Each content of SnO ₂ and CeO ₂ may be 0% by mass. Each content of SnO ₂ and CeO ₂ and can improve the clarity of the glass by each in the above range.

(Manufacture of glass)
The glass which concerns on 1st Embodiment should just prepare a glass raw material according to the well-known glass manufacturing method. For example, a plurality of kinds of compounds are prepared and mixed sufficiently to obtain a batch raw material. After the batch raw material is put into a melting vessel and melted, clarified and homogenized, a molten glass is formed and slowly cooled to obtain a glass. Alternatively, the batch raw material is put into a melting vessel and roughly melted (rough melt). The melt obtained by rough melting is rapidly cooled and pulverized to produce cullet. Further, the cullet is put in a melting vessel and heated and re-melted (remelted) to form a molten glass. Further, after clarification and homogenization, the molten glass is formed and slowly cooled to obtain glass. A publicly known method may be applied to forming molten glass and slow cooling.

The glass manufacturing process according to the first embodiment may include a process of heat-treating the molded glass in a reducing atmosphere. By heat-treating the glass in a reducing atmosphere, the degree of coloring of the glass can be increased. An example of the reducing gas used as the reducing atmosphere is hydrogen gas. Below, the heat processing process of the glass in a reducing atmosphere is explained in full detail.

First, place the shaped glass in a vacuum / gas replacement furnace and depressurize. Next, reducing gas is introduced into the furnace until atmospheric pressure is reached. Then, the temperature in the furnace is raised to a temperature 400 ° C. lower than the glass transition temperature Tg (Tg−400 ° C.) or more and below the softening point, and the temperature is maintained for about several minutes to several hours to heat-treat the glass.

In the heat treatment step in the reducing atmosphere, when hydrogen gas is used as the reducing gas, the atmosphere may be replaced with nitrogen gas before the atmosphere in the furnace is replaced with hydrogen gas. Once the atmosphere in the furnace is replaced with nitrogen gas, oxygen in the furnace is eliminated, and then ignition and the like when hydrogen gas is introduced can be prevented, and the inside of the furnace can be heated safely.

The glass manufacturing process according to the first embodiment may include a process of melting glass in a reducing atmosphere to obtain molten glass. The reducing atmosphere is preferably a strong reducing atmosphere. Moreover, the manufacturing process of the glass which concerns on this embodiment may include the process of adding a carbon-containing compound at the time of melting. By including such a step, the degree of coloring of the glass can be increased.

Further, the glass manufacturing process according to the first embodiment may include a process of increasing the amount of moisture in the molten glass. Examples of the step of increasing the amount of moisture in the molten glass include a step of adding water vapor to the melting atmosphere and a step of bubbling a gas containing water vapor in the melt. Among them, it is preferable to include a step of adding water vapor to the melting atmosphere. By including the step of increasing the amount of water in the molten glass, the βOH value of the glass can be increased.

(Crystallization)
The glass according to the first embodiment can be crystallized by heat treatment. That is, the glass according to the first embodiment may include a crystallized portion. The crystallized region may be a part or all of the glass. Crystallization includes formation of crystal nuclei. Moreover, it is preferable that the glass according to the first embodiment is not softened even when heat treatment for crystallization is performed and the shape before heating can be maintained. As a method for crystallizing glass by heat treatment, a known method can be adopted.

In the glass according to the first embodiment, the crystallinity of the crystallized portion can be 50% or more, and can be 60% or more, 70% or more, 80% or more, or 90% or more. it can.

From the X-ray diffraction profile obtained by X-ray diffraction measurement, the degree of crystallinity is divided into X-ray scattering intensity, scattering intensity due to crystals (crystal scattering intensity), and scattering intensity due to amorphous (non-crystalline scattering intensity). As shown in the following formula (2), it can be calculated as the ratio of the crystal scattering intensity to the total scattering intensity (crystal scattering intensity and amorphous scattering intensity).
Crystallinity (%) = 100 × (crystal scattering intensity) / (crystal scattering intensity + amorphous scattering intensity) (2)

(Chemical enhancement)
The glass according to the first embodiment may be chemically strengthened by bringing the glass into contact with a molten salt. In the case of chemically strengthening glass, the glass preferably contains one or both of Li ⁺ and Na ⁺ as a glass component.

The method of chemical strengthening is not particularly limited, but a low-temperature ion exchange method in which ion exchange is performed in a temperature range not exceeding the glass transition point is preferable. Chemical strengthening refers to contact between a molten chemically strengthened salt and glass, thereby causing an alkali metal element having a relatively large atomic radius in the chemically strengthened salt and an alkali having a relatively small atomic radius in the glass. This is a treatment that ion exchanges with a metal element, infiltrates an alkali metal element having a large atomic radius into the surface layer of the glass, and generates a compressive stress on the glass surface.

For example, when glass containing sodium (Na) as a glass component is immersed in a heated molten salt of potassium nitrate (KNO ₃ ), ions of sodium ions (Na ⁺ ) and potassium ions (K ⁺ ) contained in the glass An exchange occurs.

The magnitude | size of a potassium ion (K ^<+> ) is larger than the magnitude | size of a sodium ion (Na ^<+> ). Therefore, a compressive stress layer to which compressive stress is applied is formed near the surface of the glass by ion exchange. On the other hand, since the inside of glass contains sodium ions (Na ⁺ ) almost unchanged from that before chemical strengthening, it becomes a tensile stress layer to which tensile stress is applied. As described above, the compressive stress layer is formed in the vicinity of the surface, and the tensile stress layer is formed inside, so that the strength of the glass is increased.

For example, in the case of glass containing lithium (Li) as a glass component, the glass can be immersed in a molten salt composed of a mixed salt of sodium nitrate (NaNO ₃ ) and potassium nitrate (KNO ₃ ). Alternatively, after ion exchange is performed by immersing glass in a molten salt of sodium nitrate (NaNO ₃ ), ion exchange may be performed by immersing the glass in a molten salt of potassium nitrate (KNO ₃ ). The glass may be immersed in a molten salt of sodium nitrate (NaNO ₃ ) single salt or a molten salt of potassium nitrate (KNO ₃ ) single salt. Lithium ions (Li ⁺ ) near the surface of the glass may be ion-exchanged with either sodium ions (Na ⁺ ) or potassium ions (K ⁺ ) having a size larger than that of the lithium ions (Li ⁺ ).

Whether the glass is chemically strengthened can be examined by, for example, energy dispersive X-ray analysis (EDX). Specifically, the content of monovalent cations such as alkali metal and silver in the vicinity of the glass surface and inside the glass is measured by EDX. The composition inside the glass is measured by exposing the cross section of the glass, for example, by breaking the glass. A glass is considered to be chemically strengthened when the content of monovalent cations having a relatively large ionic radius near the surface of the glass is greater than the interior of the glass. It can also be confirmed by a strain gauge that measures using the photoelastic characteristics of glass.

In this embodiment, the heat treatment step in the reducing atmosphere described above may be performed before the chemical strengthening or after the chemical strengthening. Further, the visible light transmittance can be increased by applying a voltage to the glass to oxidize the glass component before or after the chemical strengthening.

(Composite glass)
The glass according to the first embodiment can be combined with other materials to form composite glass. Examples of other materials include metal materials and ceramics. That is, the composite glass according to the present embodiment may include one or both of a metal material and ceramics and the glass according to the first embodiment.

The metal material is not particularly limited, but examples include steel plates for cast iron, cast iron, stainless steel, aluminum, aluminum-plated steel plates, aluminum-zinc alloy-plated steel plates, aluminum, copper, electrolytic copper, copper-zinc alloys, silver, and gold. Can be mentioned.

The ceramic is not particularly limited, and examples thereof include ceramics, refractories, glass, cement, and fine ceramics.

The method for producing the composite glass is not particularly limited. For example, a method of applying a glass material to a metal material or ceramic, or a method of spraying it may be used. More specifically, for example, a publicly known method can be applied as a method for producing candy or a method for producing cloisonne. The frit for producing the glaze can be produced using the glass according to the first embodiment. The glaze can contain a coloring agent, an additive, etc. as needed.

The glass portion included in the composite glass may have the characteristics of the glass according to the first embodiment described above. That is, the glass portion in the composite glass can include a colored portion, a crystallized portion, or a chemically strengthened portion.

Second Embodiment The glass according to the second embodiment is
Refractive index nd is 1.750 or more,
The part whose content of Ti3 ⁺ is 0.1 mass ppm or more is included.

(Refractive index)
In the glass according to the second embodiment, the refractive index nd is 1.75 or more, and more preferably in the order of 1.76 or more, 1.77 or more, 1.78 or more, 1.79 or more, 1.80 or more. . The upper limit of the refractive index nd is not particularly limited, but is usually 2.50, preferably 2.30. In the present embodiment, the refractive index nd may be measured as it is, or may be measured after reducing the coloring of the glass. As a method for reducing coloring, for example, a method of applying a voltage, which will be described later, and a heat treatment may be mentioned. As a method for reducing the coloration of the glass by the heat treatment, there is a method in which the glass is heated in the vicinity of Tg for several hours to several tens of hours in the air atmosphere.

(Ti ³⁺ content)
The glass which concerns on 2nd Embodiment contains the part whose content of Ti3 ⁺ is 0.1 mass ppm or more. The glass according to this embodiment includes a portion in which the content of Ti ³⁺ is preferably 0.3 mass ppm or more, and the content of Ti ³⁺ is 0.5 mass ppm or more, 1 mass ppm or more, and 5 mass ppm. Or more, 10 mass ppm or more, 20 mass ppm or more, 30 mass ppm or more, 40 mass ppm or more, 45 mass ppm or more, 50 mass ppm or more, 60 mass ppm or more, 70 mass ppm or more, 80 mass ppm or more, 85 mass ppm Alternatively, a portion that is 90 ppm by mass or more may be included. The upper limit of Ti ³⁺ is not particularly limited, but is usually 10,000 ppm by mass, preferably 5000 ppm by mass. The region where the content of Ti ³⁺ is in the above range may be a part or all of the glass. The content of Ti ³⁺ can be measured by ESR (electron spin resonance method).

In the glass according to the second embodiment, the coloring is preferably a reduced color caused by a glass component, and more preferably a reduced color caused by a transition metal. Examples of the transition metal include Ti, Nb, Bi, and W.

The glass is colored according to the valence of these transition metals. For example, in Ti contained as a glass component, when tetravalent Ti ⁴⁺ is reduced to trivalent Ti ³⁺ , the glass is colored. Similarly, when Nb, Bi, and W are reduced to change their valence, the glass is colored.

Therefore, in the glass according to the present embodiment, a part of tetravalent Ti ⁴⁺ is reduced to become trivalent Ti ³⁺ is colored, that is, converted into a thickness of 1.0 mm. The maximum value of visible light transmittance can be 50% or less. And the grade of coloring in the part can be ^raised by making content of Ti3 ⁺ into the said range.

Hereinafter, the glass according to the second embodiment will be described in detail.

(Ti ion content)
In the glass according to the second embodiment, the lower limit of the Ti ion content is preferably 0.1%, and further 0.5%, 1%, 1.5%, 2%, 3%, 5%. It is more preferable in the order of 10%, 15%, 20%, and 25%. Further, the upper limit of the Ti ion content is preferably 45%, and more preferably 40%, 38%, 35%, 33%, and 30% in this order. Here, the Ti ions include all Ti ions having different valences in addition to Ti ⁴⁺ and Ti ³⁺ .

(Transmittance)
The glass according to the second embodiment includes a portion where the maximum transmittance of visible light when converted to a thickness of 1.0 mm is preferably 50% or less, and the maximum value of transmittance is 40% or less. , 30% or less, 20% or less, 15% or less, 10% or less, 5% or less, 2% or less, or 1% or less. The maximum value of visible light transmittance may be 0%. The region in which the maximum value of the visible light transmittance is in the above range in terms of the thickness of 1.0 mm may be a part or all of the glass. Visible light is light having a wavelength in the range of 400 to 760 nm.

Further, the glass according to the second embodiment includes a portion where the transmittance at a wavelength of 1100 nm when converted to a thickness of 1.0 mm is preferably 80% or less, and the transmittance at a wavelength of 1100 nm is 70% or less. 60% or less, 50% or less, 45% or less, 40% or less, 35% or less, 30% or less, 25% or less, 20% or less, 15% or less, 10% or less, 5% or less, 3% or less, 1% Hereinafter, a portion that is 0.5% or less, 0.3% or less, 0.1% or less, 0.05% or less, or 0.03% or less may be included. The region where the transmittance at a wavelength of 1100 nm when converted to a thickness of 1.0 mm is in the above range may be a part or all of the glass.

In the glass according to the second embodiment, in the colored portion, that is, the portion where the maximum transmittance of visible light is 50% or less in terms of thickness 1.0 mm, and the other portions, the glass component composition is The same. Moreover, the glass component composition is the same also in a colored part and the part which applied the voltage and decolored by the method mentioned later. However, the valence of the glass component (cation) may be different between the colored portion and the other portion. Similarly, the valence of the glass component (cation) may be different between the colored portion and the decolored portion. The same applies to a portion where the transmittance at a wavelength of 1100 nm is 80% or less in terms of a thickness of 1.0 mm and other portions.

(Electrical conductivity)
The glass according to the second embodiment includes a portion having conductivity, preferably includes a portion having an electric conductivity of 10 ⁻⁸ S / cm or more, and an electric conductivity of 10 ⁻⁷ S / cm or more, 10 ⁻⁶ S / cm or more, 10 ⁻⁵ S / cm or more, 5 × 10 ⁻⁵ S / cm or more, 10 ⁻⁴ S / cm or more, 5 × 10 ⁻⁴ S / cm or more, 10 ⁻³ S / cm or more A portion that is 5 × 10 ⁻³ S / cm or more, or 10 ⁻² S / cm or more may be included. The upper limit of the electrical conductivity is not particularly limited, but is usually 10 ² S / cm, preferably 1 S / cm. The region where the electric conductivity is in the above range may be a part or all of the glass. The electrical conductivity can be measured by, for example, an AC impedance method. The measurement temperature of the electrical conductivity is set to a temperature that is 200 ° C. lower than the glass transition temperature Tg (Tg−200 ° C.) or higher and lower than the glass transition temperature Tg.

In the glass according to the second embodiment, the conductive part is colored, that is, the maximum value of the visible light transmittance can be 50% or less in terms of a thickness of 1.0 mm. And electrical conductivity can be made into the said range by adjusting coloring of glass.

Moreover, in the glass according to the second embodiment, coloring can be reduced by applying a voltage to the glass under certain conditions to oxidize the glass component by ion conduction. That is, by applying a voltage to the colored portion of the glass under a certain condition, the visible light transmittance in that portion can be increased.

Specifically, the transmittance of the colored portion can be increased by applying a voltage while the glass according to the second embodiment is heated to a temperature equal to or lower than the glass yield point Ts.

In particular, the glass according to the second embodiment has a thickness of 1.0 mm in the atmospheric air at a temperature range of 400 ° C. lower than the glass transition temperature Tg (Tg−400 ° C.) to the softening point. When the electrode is brought into contact with the polished glass in the thickness direction and a voltage is applied under the conditions of a voltage of 20 kv or less and a processing time of 5 hours or less, the maximum transmittance at a wavelength of 400 to 760 nm is measured before and after the application of electricity. The amount of change can be 10% or more.

In the above processing, it is possible to decolorize in a pattern by applying a voltage partially.

In the glass according to this embodiment, the range of the glass transition temperature Tg is preferably 350 to 850 ° C., and further 370 to 830 ° C., 380 to 800 ° C., 400 to 770 ° C., 420 to 740 ° C., 440 It is more preferable in the order of ˜710 ° C. and 440 to 680 ° C.

In the glass according to the second embodiment, the glass composition other than the average linear expansion coefficient, acid-resistant weight reduction rate Da, βOH, color, and Ti ion content can be the same as in the first embodiment. Moreover, the glass which concerns on 2nd Embodiment can be manufactured, crystallized, and chemically strengthened similarly to 1st Embodiment, and can also be set as composite glass.

Third Embodiment The glass according to the third embodiment is
Refractive index nd is 1.75 or more,
A portion having an electric conductivity of 10 ⁻⁸ S / cm or more is included.

(Refractive index)
In the glass according to the third embodiment, the refractive index nd is 1.75 or more. Preferably it is 1.76 or more, and more preferably in the order of 1.77 or more, 1.78 or more, 1.79 or more, 1.80 or more. The upper limit of the refractive index nd is not particularly limited, but is usually 2.50, preferably 2.30. In the present embodiment, the refractive index nd may be measured as it is, or may be measured after reducing the coloring of the glass. As a method for reducing coloring, for example, a method of applying a voltage, which will be described later, and a heat treatment are exemplified. As a method for reducing the coloration of the glass by heat treatment, there is a method in which the glass is heated in the vicinity of Tg for several hours to several tens of hours in the air atmosphere.

(Electrical conductivity)
The glass according to the third embodiment includes a portion having conductivity, and specifically includes a portion having an electric conductivity of 10 ⁻⁸ S / cm or more. The glass according to this embodiment includes a portion having an electric conductivity of preferably 10 ⁻⁷ S / cm or more, and an electric conductivity of 10 ⁻⁶ S / cm or more, 10 ⁻⁵ S / cm or more, 5 × 10 ⁻⁵ S / cm or more, 10 ⁻⁴ S / cm or more, 5 × 10 ⁻⁴ S / cm or more, 10 ⁻³ S / cm or more, 5 × 10 ⁻³ S / cm or more, or 10 ⁻² S A portion that is greater than or equal to / cm may be included. The upper limit of the electrical conductivity is not particularly limited, but is usually 10 ² S / cm, preferably 1 S / cm. The region where the electric conductivity is in the above range may be a part or all of the glass. Electrical conductivity can be measured by the AC impedance method. The measurement temperature of the electrical conductivity is set to a temperature that is 200 ° C. lower than the glass transition temperature Tg (Tg−200 ° C.) or higher and lower than the glass transition temperature Tg.

In the glass according to the third embodiment, the conductive portion is colored, that is, the maximum visible light transmittance at a thickness of 1.0 mm can be 50% or less. And electrical conductivity can be made into the said range by adjusting coloring of glass.

Also, in the glass according to the third embodiment, coloring can be reduced by applying a voltage to the glass under certain conditions to oxidize the glass component by ionic conduction. That is, by applying a voltage to the colored portion of the glass under a certain condition, the visible light transmittance in that portion can be increased.

Specifically, the transmittance of the colored portion can be increased by applying a voltage in a state where the glass according to the third embodiment is heated to a temperature equal to or lower than the glass yield point Ts.

In particular, the glass according to the third embodiment has a thickness of 1.0 mm in the atmospheric air at a temperature range of 400 ° C. lower than the glass transition temperature Tg (Tg−400 ° C.) to the softening point. When the electrode is brought into contact with the polished glass in the thickness direction and a voltage is applied under the conditions of a voltage of 20 kv or less and a processing time of 5 hours or less, the maximum transmittance at a wavelength of 400 to 760 nm is measured before and after the application of electricity. The amount of change can be 10% or more.

In the above processing, it is possible to decolorize in a pattern by applying a voltage partially.

In the glass according to this embodiment, the range of the glass transition temperature Tg is preferably 350 to 850 ° C., and further 370 to 830 ° C., 380 to 800 ° C., 400 to 770 ° C., 420 to 740 ° C., 440 It is more preferable in the order of ˜710 ° C. and 440 to 680 ° C.

Hereinafter, the glass according to the third embodiment will be described in detail.

(Transmittance)
The glass according to the third embodiment includes a portion where the maximum transmittance of visible light when converted to a thickness of 1.0 mm is preferably 50% or less, and the maximum value of transmittance is 40% or less. , 30% or less, 20% or less, 15% or less, 10% or less, 5% or less, 2% or less, or 1% or less. The maximum value of visible light transmittance may be 0%. The region in which the maximum value of the visible light transmittance is in the above range in terms of the thickness of 1.0 mm may be a part or all of the glass. Visible light is light having a wavelength in the range of 400 to 760 nm.

Further, the glass according to the third embodiment includes a portion where the transmittance at a wavelength of 1100 nm when converted to a thickness of 1.0 mm is preferably 80% or less, and the transmittance at a wavelength of 1100 nm is 70% or less. 60% or less, 50% or less, 45% or less, 40% or less, 35% or less, 30% or less, 25% or less, 20% or less, 15% or less, 10% or less, 5% or less, 3% or less, 1% Hereinafter, a portion that is 0.5% or less, 0.3% or less, 0.1% or less, 0.05% or less, or 0.03% or less may be included. The region where the transmittance at a wavelength of 1100 nm when converted to a thickness of 1.0 mm is in the above range may be a part or all of the glass.

In the glass according to the third embodiment, the colored component, that is, the portion having a maximum visible light transmittance of 50% or less in terms of the thickness of 1.0 mm, and the other portion, the glass component composition is The same. Moreover, the glass component composition is the same also in the colored part and the part which applied the voltage and decolored by the method mentioned above. However, the valence of the glass component (cation) may be different between the colored portion and the other portion. Similarly, the valence of the glass component (cation) may be different between the colored portion and the decolored portion. The same applies to a portion where the transmittance at a wavelength of 1100 nm is 80% or less in terms of a thickness of 1.0 mm and other portions.

(Ti ³⁺ content)
The glass according to the third embodiment preferably includes a portion where the content of Ti ³⁺ is 0.5 mass ppm or more, and the content of Ti ³⁺ is 1 mass ppm or more, 5 mass ppm or more, 15 mass ppm or more. 25 mass ppm or more, 50 mass ppm or more, 70 mass ppm or more, or 90 mass ppm or more. The upper limit of Ti ³⁺ is not particularly limited, but is usually 10,000 ppm by mass, preferably 5000 ppm by mass. The region where the content of Ti ³⁺ is in the above range may be a part or all of the glass. The content of Ti ³⁺ can be measured by ESR (electron spin resonance method).

In the glass according to the third embodiment, the coloring is preferably a reduced color caused by a glass component, and more preferably a reduced color caused by a transition metal. Examples of the transition metal include Ti, Nb, Bi, and W.

The glass is colored according to the valence of these transition metals. For example, in Ti contained as a glass component, when tetravalent Ti ⁴⁺ is reduced to trivalent Ti ³⁺ , the glass is colored. Similarly, when Nb, Bi, and W are reduced to change their valence, the glass is colored.

Therefore, in the glass according to the present embodiment, a part of tetravalent Ti ⁴⁺ is reduced to become trivalent Ti ³⁺ is colored, that is, converted into a thickness of 1.0 mm. The maximum value of visible light transmittance can be 50% or less. And the grade of coloring in the part can be ^raised by making content of Ti3 ⁺ into the said range.

(Ti ion content)
In the glass according to the third embodiment, the lower limit of the Ti ion content is preferably 0.1%, and further 0.5%, 1%, 1.5%, 2%, 3%, 5%. It is more preferable in the order of 10%, 15%, 20%, and 25%. Further, the upper limit of the Ti ion content is preferably 45%, and more preferably 40%, 38%, 35%, 33%, and 30% in this order. Here, the Ti ions include all Ti ions having different valences in addition to Ti ⁴⁺ and Ti ³⁺ .

In the glass according to the third embodiment, the glass composition other than the average linear expansion coefficient, acid-resistant weight reduction rate Da, βOH, color, and Ti ion content can be the same as in the first embodiment. Moreover, the glass which concerns on 3rd Embodiment can be manufactured, crystallized, and chemically strengthened similarly to 1st Embodiment, and can also be set as composite glass.

Fourth Embodiment The gist of the glass according to the fourth embodiment is as follows.
[1] It has a transmittance characteristic in which the maximum value of the transmittance in a wavelength range of 500 to 1000 nm is 0.102% or less in terms of a thickness of 1.0 mm.
Colored glass that can be electrically decolored.

[2] The colored glass according to [1], wherein the transmittance is increased by applying a voltage at a temperature of 20 ° C. or lower than the glass transition temperature Tg.

[3] An electrode is disposed in the thickness direction of glass polished to a thickness of 1.0 mm in an air atmosphere at a temperature range of 400 ° C. lower than the glass transition temperature Tg and 20 ° C. lower than the glass transition temperature Tg. The coloring as described in [1] or [2], wherein the minimum value of transmittance at a wavelength of 500 to 1000 nm is 65% or more when the voltage is applied under conditions of a voltage of 1 to 20 kv and a treatment time of 5 hours. Glass.

[4] As a glass component,
Including P ₂ O ₅ ,
Including any one of Li ₂ O or Na ₂ O,
The colored glass according to any one of [1] to [3], comprising at least one oxide selected from the group consisting of TiO ₂ , Nb ₂ O ₅ , WO ₃ and Bi ₂ O ₃ .

[5] A portion having a maximum transmittance of 0.232% or less in a wavelength range of 500 to 1000 nm and a portion having a minimum transmittance of 69.59% or more in a wavelength range of 500 to 1000 nm ,
The glass molded object whose glass component composition of these parts is the same.

[6] A method for producing a colored glass comprising a step of adding water and a carbon-containing compound at the time of melting, and containing any one of Li ₂ O and Na ₂ O as a glass component.

[7] A method for producing a colored glass having a pattern-decolored portion including a step of partially applying a voltage.

[8] A method for decolorizing colored glass, including a step of applying a voltage to colored glass containing any one of Li ₂ O and Na ₂ O as a glass component.

[9] The colored glass is a glass component,
Including P ₂ O ₅ ,
The decolorization method according to [8], including at least one oxide selected from the group consisting of TiO ₂ , Nb ₂ O ₅ , WO ₃ and Bi ₂ O ₃ .

Hereinafter, the glass according to the fourth embodiment will be described in detail.

The glass according to the fourth embodiment is a colored glass having a transmittance characteristic in which the maximum value of transmittance in a wavelength range of 500 to 1000 nm is 0.102% or less in terms of a thickness of 1.0 mm. The maximum value of the transmittance may be 0%. Moreover, the glass which concerns on 4th Embodiment can be electrically decolored by the following method, for example.

That is, the glass according to the fourth embodiment can be decolorized by applying a voltage to the glass and oxidizing the glass component by ionic conduction. Specifically, by applying a voltage at a temperature not higher than 20 ° C. below the glass transition temperature Tg, the transmittance can be increased and the color can be electrically decolored. Examples of a method for applying a voltage to glass include a method in which an electrode is brought into contact with glass and a current is passed.

In particular, the glass according to the fourth embodiment was polished to a thickness of 1.0 mm in an air atmosphere at a temperature range of 400 ° C. lower than the glass transition temperature Tg and 20 ° C. lower than the glass transition temperature Tg. When the electrode is brought into contact with the glass in the thickness direction and a voltage is applied under conditions of a voltage of 1 to 20 kv and a treatment time of 5 hours, the minimum transmittance at a wavelength of 500 to 1000 nm can be set to 65% or more.

The glass according to the fourth embodiment preferably contains P ₂ O ₅ as a glass component. Further, as the glass component, any one of Li ₂ O and Na ₂ O may be contained, and at least one oxide selected from the group consisting of TiO ₂ , Nb ₂ O ₅ , WO ₃ and Bi ₂ O ₃ May be included. That is, it contains P ₂ O ₅ as a glass component, includes any one of Li ₂ O or Na ₂ O, and is selected from the group consisting of TiO ₂ , Nb ₂ O ₅ , WO ₃ and Bi ₂ O _3. At least one oxide may be included. More preferably, both Li ₂ O and Na ₂ O are contained. The glass according to the fourth embodiment may have the glass composition disclosed in WO 2017/006998 A1, and may have the same composition as the glass according to the first to third embodiments. An appropriate amount of copper may be added to the glass material as a glass component in order to impart near infrared light absorption characteristics.

The glass molded body made of glass according to the fourth embodiment may be decolorized in a pattern, and can have a portion with a high degree of coloring and a portion with a low degree of coloring. That is, the glass molded body according to the fourth embodiment has a portion where the maximum transmittance in the wavelength range of 500 to 1000 nm is 0.232% or less, and the minimum transmittance in the wavelength range of 500 to 1000 nm is 69. It has a part which is .59% or more, and the glass component composition of these parts can be the same.

In order to decolorize the glass in a pattern, for example, a voltage may be partially applied to the glass.

The glass according to the fourth embodiment may be prepared according to a known glass manufacturing method by preparing glass raw materials. The production of the glass according to the fourth embodiment can be the same as that of the first embodiment. In addition, the production of the glass according to the fourth embodiment may include a step of adding a carbon-containing compound at the time of melting. By including such a step, a deeply colored glass can be obtained. Furthermore, the manufacturing of the glass according to the fourth embodiment may include a step of adding water during melting. By including such a step, a glass having a high βOH value can be obtained.

In the glass according to the fourth embodiment, the average linear expansion coefficient, acid resistance weight reduction rate Da, and βOH can be the same as those in the first embodiment. Moreover, the glass which concerns on 4th Embodiment can be crystallized and chemically strengthened similarly to 1st Embodiment, and can be used as composite glass.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these Examples.
As glass compositions of glass materials applicable to the present invention, in addition to the glass compositions shown in the following examples, WO 2017/006998 A1, JP 2014-185075, JP 2015-067522, JP 2012-091989, JP 2006-111499, JP 2005-206433, JP 2005-075665, JP 2002-173336, JP 2018-002520, and JP 2018-002521.

(Example 1)
Glass samples having the glass compositions shown in Tables 1 to 3 were prepared according to the following procedures and subjected to various evaluations. In Tables 1, 2, and 3, No. The glass samples 1-1 to 1-4 are shown in terms of cation%, mol%, and mass%, respectively. In the mol% display and the mass% display, the glass composition is expressed on the oxide basis. Here, the “oxide-based glass composition” means a glass composition obtained by converting all glass raw materials to be decomposed during melting and existing as oxides in the glass, and the notation of each glass component is customary. Following, it is described as SiO ₂ , TiO ₂ or the like. And the mol% display is a mol percentage when the total content of all glass components is 100%. Moreover, the mass% display is a mass percentage when the total content of all glass components is 100%.

[Manufacture of glass]
Oxides, hydroxides, metaphosphates, carbonates, and nitrates corresponding to glass constituents are prepared as raw materials, and the raw materials are prepared so that the compositions of the resulting glass have the compositions shown in Tables 1 to 3. Were weighed and blended to thoroughly mix the raw materials. The obtained blended raw material (batch raw material) was put into a platinum crucible and heated at 1100 to 1450 ° C. for 2 to 3 hours to obtain a molten glass. The molten glass was stirred to homogenize and refined, and then the molten glass was cast into a mold preheated to an appropriate temperature. The cast glass was heat-treated for about 1 hour near the glass transition temperature Tg and allowed to cool to room temperature in the furnace. It processed into the magnitude | size of length 20mm, width 10mm, and thickness 1.0mm, and the two surfaces used as 20 mm x 10 mm were precision-polished, and the glass sample was obtained.

[Heat treatment in reducing atmosphere]
The glass sample was heat-treated using a vacuum / gas replacement furnace. First, a glass sample was placed in a furnace. The inside of the furnace was depressurized to about −100 kPa, and nitrogen gas was introduced into the furnace until atmospheric pressure was reached. Again, the pressure in the furnace was reduced to about −100 kPa, and hydrogen gas was introduced into the furnace until atmospheric pressure was reached. The temperature in the furnace was increased at a temperature increase rate of 50 to 400 ° C./h. No. 1-1, 650 ° C., No. 1-2, 470 ° C. 1-3, 560 ° C., no. In 1-4, the temperature was raised to 630 ° C., held at that temperature for 5 hours, and the glass was heat-treated in a hydrogen atmosphere. A colored glass sample was obtained.

[Confirmation of glass component composition]
With respect to the obtained glass sample, the content of each glass component was measured by inductively coupled plasma emission spectroscopy (ICP-AES), and it was confirmed that the composition was as shown in Tables 1 to 3.

[Refractive index nd]
The refractive index nd of the glass sample was measured by the refractive index measurement method of JIS standard JIS B 7071-1. A glass sample having a low transmittance was measured after heat treatment in the vicinity of Tg for several hours to several tens of hours to increase the transmittance. The results are shown in Table 4. In Table 4, the third decimal place of the refractive index value is rounded off and displayed to the second decimal place.

[Measurement of Ti ³⁺ content]
About the said colored glass sample, Ti3 ⁺ content was measured by ESR (electron spin resonance method).
As a result, sample no. In 1-1, the content of Ti ³⁺ was 98 mass ppm.

[Transmissivity]
The external transmittance at a wavelength of 400 to 760 nm was measured for the colored glass sample and the glass sample before heat treatment in a reducing atmosphere. The external transmittance is defined as the percentage of the transmitted light intensity with respect to the incident light intensity when the light is incident in the thickness direction of the sample [transmitted light intensity / incident light intensity × 100]. The external transmittance includes a reflection loss of light rays on the sample surface. Sample No. The results for 1-1 to 1-4 are shown in FIGS. 1 to 4, respectively.

No. In the colored glass sample having a composition of 1-1 after heat treatment in a reducing atmosphere, as shown in FIG. 1, the maximum transmittance at a wavelength of 400 to 760 nm was 0.00%.

No. In the colored glass sample having the composition of 1-2 after the heat treatment in a reducing atmosphere, as shown in FIG. 2, the maximum transmittance at a wavelength of 400 to 760 nm was 0.01%.

No. In the colored glass sample having a composition of 1-3 after heat treatment in a reducing atmosphere, the maximum transmittance at a wavelength of 400 to 760 nm was 0.02% as shown in FIG.

No. In the colored glass sample having the composition of 1-4 after heat treatment in a reducing atmosphere, the maximum transmittance at a wavelength of 400 to 760 nm was 1.95% as shown in FIG.

(Example 2)
Glass samples having the glass compositions shown in Tables 5 to 7 were prepared by the following procedures and subjected to various evaluations. In Tables 5, 6, and 7, No. The glass samples of 2-1 to 2-50 are shown in terms of cation%, mol%, and mass%, respectively. The mol% display and the mass% display are the same as in Example 1.

[Manufacture of glass]
Fluoride, oxide, hydroxide, carbonate, and nitrate corresponding to glass constituents are prepared as raw materials, and the raw materials are prepared so that the glass composition of the obtained glass has the respective compositions shown in Tables 5-7. Were weighed and blended to thoroughly mix the raw materials. The obtained blended raw material (batch raw material) was put into a platinum crucible and heated at 1300 to 1450 ° C. for 2 to 3 hours to obtain a molten glass. With the platinum crucible covered, water or an aqueous solution of a carbon-containing compound, that is, 1.5 to 40 cc of an aqueous ethanol solution of 0 to 1 vol% was sprayed on the molten glass and added. Thereafter, the molten glass was stirred to homogenize and clarified, and then the molten glass was cast into a mold preheated to an appropriate temperature. The cast glass was heat-treated for about 1 hour near the glass transition temperature Tg and allowed to cool to room temperature in the furnace. A glass sample was obtained by processing into a size of 40 mm in length, 10 mm in width, and 1 mm in thickness, and precisely polishing the surface of 40 mm × 10 mm.

[Confirmation of glass component composition]
With respect to the obtained glass sample, the content of each glass component was measured by inductively coupled plasma emission spectroscopy (ICP-AES), and it was confirmed that the composition was as shown in Tables 5 to 7.

[Chemical strengthening]
The glass sample, a simple salt of KNO _3, or immersed in a molten salt composed of a mixed salt of KNO ₃ and NaNO _3, to obtain a chemically strengthened samples. At this time, the temperature of the molten salt was 380 ° C., and the immersion time was 4 hours.

[Refractive index nd]
The refractive index nd of the glass sample was measured by the refractive index measurement method of JIS standard JIS B 7071-1. A glass sample having a low transmittance was measured after heat treatment in the vicinity of Tg for several hours to several tens of hours to increase the transmittance. In Table 8, the third decimal place of the refractive index nd is rounded off to the second decimal place.

The value of refractive index nd described in Table 8 includes a value obtained by calculation in addition to a value obtained by measurement. The value obtained by calculation was determined as follows. It is widely known that additivity holds for the refractive index of glasses having similar compositions. Therefore, the refractive index of glass A can be predicted from the composition and refractive index of glass B having a composition similar to that of glass (referred to as glass A) whose refractive index is to be predicted. .

Hereinafter, an example of a refractive index prediction method will be described. Data on the amount of change in refractive index when part or all of the specific component C (1) contained in the glass B is replaced with another component B (2), B (3)... B (n). To collect. Divide the collected refractive index change amount by the replacement amount of each component, calculate the change amount of the refractive index per unit replacement amount of each component, and plot it uniaxially. In the range where the composition is similar, the positional relationship of the refractive index change amount of each component does not change greatly, so that the plotted component B is obtained from the glass C having a known refractive index (having a composition similar to the glasses A and B). The refractive index of the glass C ′ when (x) and B (y) are replaced is the difference between the refractive indexes nd (C) and B (x) and B (y) plotted in the refractive index variation of the glass C. Using Δnd (y−x),
nd (C) + Δnd (y−x)
Can be calculated as

[Transmissivity]
For the glass sample (glass sample before strengthening) and the chemically strengthened sample, the external transmittance at a wavelength of 400 to 760 nm was measured in the same manner as in Example 1.
As a result, no. In a glass sample having a composition of 2-1 to 2-50 (glass sample before strengthening) and a chemically strengthened sample, the maximum transmittances at wavelengths of 400 to 760 nm were all 5% or less.

[Folding strength (bending strength)]
About the said glass sample (glass sample before reinforcement | strengthening) and a chemical strengthening sample, bending strength (bending strength) was measured by the 3 point | piece bending test method prescribed | regulated to JISR1601: 2008. The distance between fulcrums was 30 mm. The results are shown in Table 8.

The number of specimens was 5 or more. That is, 5 or more glass samples and chemical strengthening samples were prepared for each composition. The maximum value obtained was taken as the bending strength.

[specific gravity]
About the said chemical strengthening sample, specific gravity was measured by the Archimedes method. The results are shown in Table 8.

[Glass transition temperature Tg]
About the said chemical strengthening sample, the glass transition temperature Tg was measured at the temperature increase rate of 10 degree-C / min using the differential scanning calorimetry apparatus (DSC8270) made from Rigaku. The results are shown in Table 8.

Example 3-1
A glass sample having the glass composition shown in Table 9 was prepared by the following procedure and subjected to various evaluations.

[Manufacture of glass]
Prepare oxides, hydroxides, metaphosphates, carbonates, and nitrates corresponding to the glass constituents as raw materials, and weigh the raw materials so that the resulting glass has the compositions shown in Table 9. Prepared and mixed raw materials thoroughly. The obtained blended raw material (batch raw material) was put into a platinum crucible and heated at 1100 to 1450 ° C. for 2 to 3 hours to obtain a molten glass. The molten glass was stirred to homogenize and refined, and then the molten glass was cast into a mold preheated to an appropriate temperature. The cast glass was heat-treated for about 1 hour near the glass transition temperature Tg and allowed to cool to room temperature in the furnace. It processed into the magnitude | size of length 20mm, width 10mm, and thickness 1.0mm, and the two surfaces used as 20 mm x 10 mm were precision-polished, and the glass sample was obtained.

[Confirmation of glass component composition]
About the obtained glass sample, the content of each glass component was measured by inductively coupled plasma emission spectroscopy (ICP-AES), and it was confirmed that the composition was as shown in Table 9.

[Refractive index nd]
The refractive index nd of the glass sample was measured by the refractive index measurement method of JIS standard JIS B 7071-1. A glass sample having a low transmittance was measured after heat treatment in the vicinity of Tg for several hours to several tens of hours to increase the transmittance. The results are shown in Table 9. In Table 9, the third decimal place of the refractive index nd is rounded off and displayed to the second decimal place.

[specific gravity]
Specific gravity was measured by the Archimedes method. The results are shown in Table 9.

[Glass transition temperature Tg]
The glass transition temperature Tg was measured at a heating rate of 4 ° C./min using a thermomechanical analyzer (TMA4000S) manufactured by MAC Science. The results are shown in Table 9.

[Average linear expansion coefficient]
The average linear expansion coefficient was measured according to the Japan Optical Glass Industry Association Standard JOGIS 08-2003 “Measurement Method of Thermal Expansion of Optical Glass”. The diameter of the round bar-shaped sample was 5 mm. The results are shown in Table 9.

[Acid resistance weight reduction rate Da]
In accordance with the provisions of Japan Optical Glass Industry Association Standard JOGIS06-2009, the obtained glass sample is made into a powder glass (particle size 425-600 μm) having a weight corresponding to the specific gravity, and placed in a platinum basket. The sample was immersed in a quartz glass round bottom flask and treated in a boiling water bath for 60 minutes, and the weight loss rate (%) before and after the treatment was measured. The weight loss rate was evaluated by grade. The results are shown in Table 9.

(Example 3-2)
[Heat treatment in reducing atmosphere]
Sample No. shown in Table 9 The glass sample 3-4 was heat-treated in a reducing atmosphere in the same manner as in Example 1 except that the temperature was raised to 450 ° C. and maintained at that temperature for 0 to 116 hours. Thereafter, in the same manner as in Example 1, the external transmittance in the visible light region (wavelength 400 to 760 nm) was measured. Furthermore, the external transmittance at a wavelength of 1100 nm was measured.
Table 10 shows the processing time, the maximum transmittance in the visible light region, and the transmittance at a wavelength of 1100 nm.

[ΒOH]
The glass sample was processed into a plate-like glass sample having a thickness of 1 mm and planes parallel to each other and optically polished. Light is incident on the polished surface of the plate glass sample from the vertical direction, and external transmittance A at a wavelength of 2500 nm and external transmittance B at a wavelength of 2900 nm are measured using a spectrophotometer, respectively, and the following formula (1) Was used to calculate βOH. The results are shown in Table 10.
βOH = − [ln (B / A)] / t (1)

In the above formula (1), ln is a natural logarithm, and the thickness t corresponds to the interval between the two planes. The external transmittance includes a reflection loss on the surface of the glass sample and is a ratio of transmitted light intensity to transmitted light intensity (transmitted light intensity / incident light intensity).

(Example 3-3)
Glasses were produced under the melting conditions shown in Table 11 and the heat treatment conditions in a reducing atmosphere.

In Table 11, No. 3-1, 3-3, 3-4, and 3-5 are Nos. In Table 9, respectively. 3-1, 3-3, 3-4, and 3-5 have the same glass composition and glass characteristics.
No. in Table 11 3-2-A and 3-2-B are Nos. It has the same glass composition and glass characteristics as 3-2.
Similarly, no. 3-6-A and 3-6-B are Nos. It has the same glass composition and glass characteristics as 3-6.
No. 3-7-A to 3-7-H are Nos. Has the same glass composition and glass properties as 3-7. Melting conditions and heat treatment conditions in a reducing atmosphere will be described below.

[Melting conditions]
No. shown in Table 11 In 3-1, 3-2-A, 3-3, 3-5, 3-7-B, 3-8, and 3-7-H, steam was added to the melting atmosphere in the glass melting step.
No. In 3-7-C, water vapor was added to the melting atmosphere in the glass melting step, and ethanol was further added to the molten glass.
No. In 3-7-D, nitrogen gas was added to the melting atmosphere in the glass melting step.
No. In 3-7-F, mannitol was added to the molten glass.

[Heat treatment conditions in reducing atmosphere]
No. 3-1, 3-2-A, 3-2-B, 3-3, 3-5, 3-6-A, 3-6-B, 3-7-G, 3-8, 3-7- In H and 3-4, heat treatment was performed in a reducing atmosphere in the same manner as in Example 1 except that the temperature was raised to the temperature shown in Table 11 and maintained at that temperature for the time shown in Table 11.

[Ti ³⁺ content]
No. shown in Table 11 For glass samples of 3-2-A, 3-6-A, 3-7-A to 3-7-C, 3-7-H, 3-4, the Ti ³⁺ content was determined by ESR (electron spin resonance method). Measured with In the same manner as in Example 3-1, the maximum value of the transmittance in the visible light region and the transmittance at a wavelength of 1100 nm were measured. The results are shown in Table 12.

[Electric conductivity]
No. shown in Table 11 The glass samples of 3-1, 3-2-B, 3-3, 3-5, 3-6-B, 3-7-A to 3-7-G, 3-8 were analyzed by the AC impedance method. The electrical conductivity at the measurement temperature shown in FIG. Further, the maximum value of the transmittance in the visible light region and the transmittance at a wavelength of 1100 nm were measured by the same method as in Example 3-1. The results are shown in Table 13.

(Example 3-4)
[Chemical strengthening]
As shown in Table 10, No. 8 heat-treated in a reducing atmosphere for 8 hours. As shown in Table 14, the 3-4 glass sample was immersed in a molten salt composed of a mixed salt having a molar ratio of KNO ₃ and NaNO ₃ of 5: 5 to obtain a chemically strengthened sample. At this time, the temperature of the molten salt was 340 ° C., and the immersion time was 2 hours.

No. shown in Table 11 The glass sample of 3-5 was immersed in a molten salt of a simple salt of KNO ₃ to obtain a chemically strengthened sample. At this time, the temperature of the molten salt was 420 ° C., and the immersion time was 4 hours.

No. shown in Table 11 3-8 glass samples were immersed in a molten salt of a simple salt of KNO ₃ to obtain a chemically strengthened sample. At this time, the temperature of the molten salt was 420 ° C., and the immersion time was 4 hours.

No. shown in Table 11 The glass sample of 3-2 was immersed in a molten salt of a single salt of NaNO ₃ and then immersed in a molten salt of a single salt of KNO ₃ to obtain a chemically strengthened sample. At this time, the temperature of the molten salt was 420 ° C., and the total immersion time was 4 hours.

[Folding strength (bending strength)]
About the said chemical strengthening sample, the bending strength (bending strength) was measured by the 3 point | piece bending test method prescribed | regulated to JISR1601: 2008. The dimension of the measurement sample was 40 mm × 10 mm × 1 mm, and the distance between fulcrums was 30 mm. The number of specimens was 5 or more. Table 14 shows the average value, maximum value, and minimum value of the obtained numerical values.

Example 4-1
A glass sample having the glass composition shown in Table 15 was prepared by the following procedure and subjected to various evaluations.

[Manufacture of glass]
Prepare fluorides, oxides, hydroxides, carbonates and nitrates corresponding to the glass constituents as raw materials, and weigh the above raw materials so that the glass composition of the resulting glass is as shown in Table 15 Prepared and mixed raw materials thoroughly. The obtained blended raw material (batch raw material) was put into a platinum crucible and heated at 1300 ° C. for 2 to 3 hours to obtain a molten glass. With the platinum crucible covered, water and a carbon-containing compound, that is, a 0.1 wt% aqueous ethanol solution was sprayed onto the molten glass and added. Thereafter, the molten glass was stirred to homogenize and clarified, and then the molten glass was cast into a mold preheated to an appropriate temperature. The cast glass was heat-treated for about 1 hour near the glass transition temperature Tg, and allowed to cool to room temperature in a furnace to obtain a glass sample.

[Confirmation of glass component composition]
With respect to the obtained glass sample, the content of each glass component was measured by inductively coupled plasma emission spectroscopy (ICP-AES), and it was confirmed that the composition was as shown in Table 15.

[Measurement of optical properties]
About the obtained glass sample, refractive index nd, Abbe number νd, specific gravity, and glass transition temperature Tg were measured. The results are shown in Table 16.

(I) Refractive index nd and Abbe number νd
The refractive indexes nd, ng, nF, and nC were measured by the refractive index measurement method of JIS standard JIS B 7071-1, and the Abbe number νd was calculated based on the following equation.
νd = (nd−1) / (nF−nC)
In Table 16, the sixth decimal place of the refractive index nd is rounded off and displayed to the fifth decimal place.

(Ii) Specific gravity The specific gravity was measured by the Archimedes method.

(Iii) Glass transition temperature Tg
Using a thermomechanical analyzer (TMA4000S) manufactured by MAC Science, the temperature was increased at a rate of 4 ° C./min.

[Measurement of transmittance]
The glass sample was processed to have flat surfaces that were 1 mm in thickness and parallel to each other and optically polished, and the external transmittance at a wavelength of 300 to 2500 nm was measured. The external transmittance is defined as a percentage of transmitted light intensity with respect to incident light intensity [transmitted light intensity / incident light intensity × 100] when light is incident in the thickness direction of the glass sample. The external transmittance includes a reflection loss of light rays on the sample surface. The results are shown in FIG.

(Example 4-2)
In the production of glass, a glass sample was obtained in the same manner as in Example 4-1, except that a 0.3 wt% ethanol aqueous solution was sprayed onto the molten glass instead of the 0.1 wt% ethanol aqueous solution. The transmittance of the obtained glass sample was measured in the same manner as in Example 4-1. The results are shown in FIG.

(Example 4-3)
In the production of glass, a glass sample was obtained in the same manner as in Example 4-1, except that a 0.5 wt% ethanol aqueous solution was sprayed onto the molten glass instead of the 0.1 wt% ethanol aqueous solution. The transmittance of the obtained glass sample was measured in the same manner as in Example 4-1. The results are shown in FIG.

(Example 4-4)
In the production of glass, a glass sample was obtained in the same manner as in Example 4-1, except that a 5 wt% ethanol aqueous solution was sprayed onto the molten glass instead of the 0.1 wt% ethanol aqueous solution. The transmittance of the obtained glass sample was measured in the same manner as in Example 4-1. The results are shown in FIG.

(Comparative Example 4-1)
A glass sample was obtained in the same manner as in Example 4-1, except that water and a carbon-containing compound were not added to the molten glass in the production of glass (no atmosphere control). The transmittance of the obtained glass sample was measured in the same manner as in Example 4-1. The results are shown in FIG.

(Example 4-5)
A voltage was applied to the glass sample obtained in Example 4-2 under the following conditions to electrically perform pattern-like decolorization. A schematic diagram of the apparatus used for applying the voltage is shown in FIG.

As shown in Fig. 6, place the conducting wire on the glass sample and apply the voltage using the application device (GC-90, manufactured by Green Techno Co., Ltd.) in the heat treatment furnace (KDF-75, manufactured by Denken Hydental Co., Ltd.). , Decolorized. In an air atmosphere, the treatment time was 3 hours, the temperature of the heat treatment furnace was 400 ° C., the voltage was 9 kv, and the current was 55 μA.

As electrodes, platinum, carbon, and SUS304 electrodes were used. As the conducting wire, a copper wire was used outside the furnace, and a platinum wire (wire diameter 0.8 mm) was used inside the furnace. The platinum wire was arranged so that the platinum wire was in direct contact with the glass at the contact portion of the glass, and the other portion was covered with a hollow quartz tube. The open part of the heat treatment furnace was sealed with a heat insulating material (ceramic fiber, refractory brick).

The photograph of the glass sample after decoloring is shown in FIG.
Moreover, the transmittance | permeability of the decoloring part and non-decoloring part of a glass sample is shown in FIG.
Furthermore, the photograph of the cross section of the boundary of a decoloring part and a non-decoloring part is shown in FIG.

Example 5-1
A glass sample having the glass composition shown in Table 17 was produced in the same procedure as in the production of the glass of Example 3-1.

The glass component composition was confirmed in the same manner as in Example 3-1. Further, in the same manner as in Example 3-1, the refractive index nd, specific gravity, glass transition temperature Tg, average expansion coefficient, and acid resistance weight reduction rate Da were measured. The results are shown in Table 17. In Table 17, the third decimal place of the refractive index nd is rounded off to the second decimal place.

(Example 5-2)
Glasses were produced under the melting conditions shown in Table 18 and the heat treatment conditions in a reducing atmosphere.

In Table 18, No. 5-1, 5-4, and 5-5 are Nos. In Table 17, respectively. 5-1, 5-4, and 5-5 have the same glass composition and glass characteristics.
No. in Table 18 5-2A and 5-2B are No. 5 in Table 17. It has the same glass composition and glass characteristics as 5-2.
Similarly, no. Nos. 5-3-A, 5-3-B, and 5-3-C are shown in Table 17. It has the same glass composition and glass properties as 5-3.
Melting conditions and heat treatment conditions in a reducing atmosphere will be described below.

[Melting conditions]
No. shown in Table 18 In 5-3-B, water vapor was added to the melting atmosphere in the glass melting step.
No. shown in Table 18 In 5-2B, water vapor was added to the melting atmosphere in the glass melting step, and alcohol was further added to the molten glass.

[Heat treatment conditions in reducing atmosphere]
No. In 5-1, 5-2A, 5-2B, 5-3-C, 5-4, and 5-5, the temperature is raised to the temperature shown in Table 18, and the temperature is maintained for the time shown in Table 18 Except that, heat treatment was performed in a reducing atmosphere in the same manner as in Example 1.

[ΒOH]
For the obtained glass sample, βOH was measured in the same manner as in Example 3-2. The results are shown in Table 18.

[Transmissivity]
No. shown in Table 18 For glass samples of 5-1, 5-2A, 5-2B, 5-3-A, 5-3-B, 5-3-C, 5-4, and 5-5, Example 3- 1 was used to measure the maximum transmittance in the visible light region and the transmittance at a wavelength of 1100 nm.

[Color and transmission curve]
For the glass samples shown in Table 18, the color was observed. In addition, a transmittance curve in the visible light region was created. It is shown in FIGS.

No. The glass samples of 5-3-A, 5-3-B, and 5-4 were bluish. These transmittance curves are shown in FIG.
In particular, no. The glass samples of 5-3-A and 5-3-B were bluish black. 11 is an enlarged view of the vertical axis of FIG. The transmittance curve of a glass sample of 5-3-B is shown.

No. The glass sample of 5-1 was reddish black. The transmittance curve is shown in FIG.

No. 5-2A and 5-2B were magenta black. The transmittance curve is shown in FIG.

Claims (15)

Refractive index nd is 1.75 or more,
Glass including a portion where the maximum value of visible light transmittance is 50% or less in terms of a thickness of 1.0 mm. Refractive index nd is 1.75 or more,
Glass including a portion having a Ti ³⁺ content of 0.1 mass ppm or more. Refractive index nd is 1.75 or more,
Glass including a portion having an electric conductivity of 10 ⁻⁸ S / m or more. The glass according to any one of claims 1 to 3, which is phosphate glass. The glass according to any one of claims 1 to 4, comprising 1 cation% or more of Nb ions as a glass component. The glass according to any one of claims 1 to 5, comprising 0.5 cation% or more of Ti ions as a glass component. The glass according to any one of claims 1 to 6, which contains a total of 0.1 cation% or more of Li ⁺ and Na ⁺ as glass components. The glass according to any one of claims 1 to 7, which has an average linear expansion coefficient of 50 × 10 ^-7 K ^-1 or more. The glass according to any one of claims 1 to 8, wherein the acid resistance based on JOGIS is 1 grade. The glass according to any one of claims 1 to 9, comprising a crystallized portion. The glass according to any one of claims 1 to 10, comprising a chemically strengthened portion. Composite glass comprising one or both of a metal material and ceramics and the glass according to any one of claims 1 to 11. Including a step of heat-treating the molded glass in a reducing atmosphere,
A method for producing glass comprising a portion having a refractive index nd of 1.75 or more and a maximum visible light transmittance of 50% or less in terms of a thickness of 1.0 mm. Including a step of obtaining molten glass in a reducing atmosphere,
A method for producing glass comprising a portion having a refractive index nd of 1.75 or more and a maximum visible light transmittance of 50% or less in terms of a thickness of 1.0 mm. Including the step of adding water vapor to the molten atmosphere,
A method for producing glass comprising a portion having a refractive index nd of 1.75 or more and a maximum visible light transmittance of 50% or less in terms of a thickness of 1.0 mm.

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