JP2006290661A - Glass substrate for display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a glass substrate for display which has a suitable visible light transmittance, provides a high contrast, is easy in adjusting luminescent tone, and is excellent in absorbing power of near infrared ray. <P>SOLUTION: The glass substrate for display has a glass composition having a basic glass composition of an SiO<SB>2</SB>-Al<SB>2</SB>O<SB>3</SB>-R<SB>2</SB>O-RO system to which there are added 0.5-5.5% of total iron oxide [T-Fe<SB>2</SB>O<SB>3</SB>] in terms of Fe<SB>2</SB>O<SB>3</SB>, 50-400 ppm of CoO, and NiO and Se represented by ppm in an amount within the range of 100≤40×[Se]+[NiO]≤800. The glass substrate for display with a thickness of 1.0-2.8 mm has a visible light transmittance as measured using the light source C of 40-70% and has a<SP>*</SP>and b<SP>*</SP>of within the range of -10≤a<SP>*</SP>≤5 and -10≤b<SP>*</SP>≤5, respectively, when indicated by the L<SP>*</SP>a<SP>*</SP>b<SP>*</SP>color system. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a glass substrate for display containing a coloring component. In particular, the present invention relates to a glass substrate for display that has excellent near-infrared absorptivity and can easily adjust the color tone of plasma emission when applied to a plasma display device.

  In the plasma display device, a part of the light emitted from a certain cell is repeatedly reflected on the inner surface of the front glass substrate of the plasma display device, enters into an adjacent cell, and the image is blurred. This phenomenon is called halation. In order to suppress this halation, it has been proposed to color this glass substrate.

For example, Japanese Patent Laid-Open No. 11-1342 discloses a front glass for a plasma display device in which 20 to 500 ppm of CoO and 150 to 2000 ppm of NiO are contained in a SiO ₂ —Al ₂ O ₃ —RO—R ₂ O base glass. A substrate is disclosed. Japanese Patent Application Laid-Open No. 11-349346 similarly discloses a front glass substrate for a plasma display device in which NiO / CoO is defined with respect to a SiO ₂ —Al ₂ O ₃ —RO—R ₂ O-based basic glass.

  Furthermore, in the color plasma display device, there are problems that the contrast of the image is reduced or the black display is tinted by sunlight or external light from the lighting fixtures entering the screen. ing.

In view of this, Japanese Patent Application Laid-Open No. 11-171588 is characterized by containing 0.1 to 10% by weight of Nd ₂ O ₃ , and even if NiO or CoO is added to obtain high contrast, high brightness is achieved. A substrate glass for a plasma display capable of obtaining a color image is disclosed.

  Further, in Japanese Patent Application Laid-Open Nos. 11-233303, 11-260272, and 2001-60439, even if the glass substrate is colored, high luminance, high contrast, and sufficient color temperature are obtained. Technology is disclosed. That is, it is a glass substrate for a plasma display that defines the light transmittance at a predetermined wavelength and the relationship thereof.

  Further, the present applicant also added cobalt oxide and iron oxide as coloring components in JP-A-2001-139342, and further defined the weight ratio of divalent iron oxide and total iron oxide in the iron oxide. A front glass substrate for a plasma display device is disclosed. This is a glass substrate with enhanced near infrared absorption.

In the plasma display device, near infrared rays are emitted along with plasma discharge. This near-infrared ray is also emitted near the plasma display device through the front glass substrate. If there is a light receiving portion of a device operated by infrared rays, near infrared light from the plasma display device enters the light receiving portion, and the device may malfunction. In order to prevent this, it is desired that the front glass substrate has a near infrared absorbing ability.
Japanese Patent Application Laid-Open No. 11-1342 Japanese Patent Laid-Open No. 11-349346 Japanese Patent Laid-Open No. 11-171588 Japanese Patent Laid-Open No. 11-233303 Japanese Patent Laid-Open No. 11-260272 JP 2001-60439 A JP 2001-139342 A

  In the glass substrate disclosed in the above-mentioned JP-A-11-1342 and JP-A-11-349346, there is no description that Se is contained, and the color tone of the glass substrate is not defined. Further, although visible light transmittance at a specific wavelength is shown, there is no mention of absorption of near infrared rays.

Further, the substrate glass disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 11-171487 contains Nd ₂ O ₃ , but since this Nd ₂ O ₃ is an expensive raw material, the manufacturing cost increases.

Further, the substrate glass disclosed in the above-mentioned Japanese Patent Application Laid-Open Nos. 11-233303, 11-260272, and 2001-60439 defines the light transmittance at a predetermined wavelength and the relationship thereof. . However, as a specific configuration, Nd ₂ O ₃ is contained or NiO or CoO is contained. There is no description that Se is contained, and the color tone of the glass substrate is not specified.

  Moreover, in the front glass substrate which this applicant disclosed by Unexamined-Japanese-Patent No. 2001-139342, the light of a near-infrared area | region is absorbed effectively. For this reason, the glass substrate tends to have a blue color. When this glass substrate is applied to the front glass substrate of a display device, it is necessary to further improve the color tone of the glass substrate in order to facilitate the adjustment of the emission color tone of the display device.

  Therefore, the present invention is suitable for a display having an appropriate visible light transmittance, high contrast, easy adjustment of emission color tone, and excellent near-infrared absorption when applied to a plasma display device, for example. The purpose is to provide a glass substrate.

Accordingly, the glass substrate for display of the present invention is a SiO ₂ —Al ₂ O ₃ —R ₂ O—RO-based basic glass composition, in which a coloring component is appropriately selected, and the addition amount thereof is adjusted, and further its optical characteristics By defining the above, the above-mentioned object is achieved.

That is, as an invention according to claim 1,
Expressed in mass proportion, the basic glass composition is substantially
SiO ₂ 55~65%,
Al ₂ O ₃ 1-12%,
Na ₂ O 0-5%,
K ₂ O 5-15%,
MgO 1-15%,
CaO 1-12%,
SrO 5-20%,
BaO 0-10%,
ZrO ₂ 0-5%,
SO ₃ 0 to 0.3%,
Consisting of
As a coloring component, the mass of the basic glass composition is used as a denominator, and expressed as a mass ratio with respect to the denominator.
Total iron oxide [T-Fe ₂ O _3] and a 0.5 to 5.5% with terms of Fe ₂ O _3,
CoO is 50 to 400 ppm,
When the mass ratio of NiO and Se expressed in ppm is [NiO] and [Se], respectively, the NiO and Se are:
100 ≦ 40 × [Se] + [NiO] ≦ 800
It is a glass substrate for display using a glass composition added so as to be in the range of
When the thickness of the substrate is 1.0 to 2.8 mm, the visible light transmittance measured using a C light source is 40 to 70%, and L ^* a ^* defined by JIS Z 8729 A glass substrate for a display, wherein a ^* and b ^* expressed in the b ^* color system are in the range of −10 ≦ a ^* ≦ 5 and −10 ≦ b ^* ≦ 5, respectively.

As invention of Claim 2,
The glass substrate for display according to claim 1,
The NiO and Se are
400 ≦ 40 × [Se] + [NiO] ≦ 800
It is added to be within the range of
The a ^* and b ^* are display glass substrates in the range of −7 ≦ a ^* ≦ 2, −5 ≦ b ^* ≦ 2, respectively.

As invention of Claim 3,
In the glass substrate for a display according to claim 1 or 2,
The basic glass composition is substantially
SiO ₂ 55~62%,
Al ₂ O ₃ 2-6%,
Na ₂ O 0-5%,
K ₂ O 8-12%,
MgO 1-15%,
CaO 2-5%,
SrO 8-15%,
BaO 0 to 1%,
ZrO ₂ 0 to 3%,
SO ₃ 0.01 to 0.2%,
It is the glass substrate for displays which consists of these components.

As invention of Claim 4,
In the glass substrate for a display according to any one of claims 1 to 3,
The glass composition does not substantially contain Se, and when the mass ratio of FeO converted to Fe ₂ O ₃ and the total iron oxide is [FeO / T—Fe ₂ O ₃ ], the ratio is 0. A glass substrate for display in the range of 2 to 0.5.

As invention of Claim 5,
In the glass substrate for a display according to any one of claims 1 to 3,
The glass composition does not substantially contain NiO, and when the mass ratio of FeO converted to Fe ₂ O ₃ and the total iron oxide is [FeO / T—Fe ₂ O ₃ ], the ratio is 0. A glass substrate for display in a range of .25 to 0.5.

  As described above, the glass substrate for display according to the present invention can absorb near infrared rays effectively and can maintain the color tone of the glass substrate in a neutral manner.

In this specification, the neutral color tone is basically used in the sense that it is an achromatic color and may have a slight tint.
^{Specifically, L * a * b * a} * expressed by color system, b ^*, respectively, -10 ≦ a ^* ≦ 5, with the scope of -10 ≦ b ^* ≦ 5.

  Below, the reason for limitation of a glass composition is demonstrated. First, the basic glass composition will be described. Hereinafter, each content is mass% or mass ppm.

[Basic glass composition]
The basic glass composition in the present invention is determined from the viewpoint of application to a display glass substrate. For example, in a plasma display device, a high temperature step of 500 ° C. or higher is performed in the manufacturing process, and thus the glass composition needs to have a high strain point. Specifically, the strain point may be 560 ° C. or higher.

Furthermore, it is required that the thermal expansion coefficient of the insulating paste or sealing material used in this manufacturing process matches that of the glass substrate. Specifically, the thermal expansion coefficient may be in the range of 80 to 90 × 10 ⁻⁷ / K.

  From the above viewpoint, the content of each component of the basic glass composition in the present invention is determined.

(SiO ₂ )
SiO ₂ is an essential component for forming a glass skeleton. In the glass substrate for a display in the present invention, if the content is less than 55%, the strain point of the glass becomes low, so that the glass substrate tends to shrink. On the other hand, if the content exceeds 65%, the thermal expansion coefficient becomes too small. Therefore, the content of SiO ₂ is 55 to 65%, more preferably 55 to 62%, and still more preferably 56 to 60%.

(Al ₂ O ₃ )
Al ₂ O ₃ is an essential component for improving the weather resistance while increasing the strain point of the glass. If the content is less than 1%, those effects cannot be obtained. On the other hand, if the content exceeds 10%, the strain point of the glass becomes too high and the thermal expansion coefficient becomes too small. Accordingly, from 1 to 10 percent content of Al ₂ O _3, 2~6% is more preferable.

(Na ₂ O, K ₂ O: alkali metal oxide)
Both Na ₂ O and K ₂ O are components for facilitating melting of the glass and controlling the thermal expansion coefficient. If the content of K ₂ O is less than 5%, the thermal expansion coefficient is too low. On the other hand, when the content exceeds 15%, devitrification is likely to occur. Therefore, the content of K ₂ O is 5 to 15%, and more preferably 8 to 12%.
Further, Na ₂ O is preferably 5% or less and may be omitted because it significantly lowers the volume resistivity of the glass substrate for display. Therefore, the content of Na ₂ O is 0 to 5%.

(MgO, CaO, SrO, BaO: alkaline earth metal oxide)
MgO, CaO, SrO, and BaO are all components for facilitating melting of the glass and controlling the thermal expansion coefficient.
When the MgO content is less than 1%, the thermal expansion coefficient becomes small. On the other hand, if the content exceeds 15%, the glass tends to be devitrified, making it difficult to form the glass. Therefore, the content of MgO is 1 to 15%.
When the CaO content is less than 1%, the thermal expansion coefficient becomes small. On the other hand, if the content exceeds 12%, the glass tends to be devitrified, making it difficult to form the glass. The content of CaO is 1 to 12%, and 2 to 5% is more preferable.
SrO is a component that lowers the high temperature viscosity of the glass and effectively improves the meltability. If the content is less than 5%, the high-temperature viscosity becomes too high and melting becomes difficult. On the other hand, when the content exceeds 20%, devitrification is likely to occur. Therefore, the SrO content is 5 to 20%, and more preferably 8 to 15%.
BaO, like SrO, aids melting, but it is desirable not to use it as much as possible in consideration of environmental burdens. Therefore, the BaO content is 0 to 10%, preferably 1% or less, and more preferably not contained.

(ZrO ₂ )
ZrO ₂ is a component that improves the chemical durability of glass. When the content exceeds 5%, the coefficient of thermal expansion becomes too small, and devitrified substances are easily generated when the glass is melted, making it difficult to form the glass. Therefore, the content of ZrO ₂ is 0 to 5%, preferably 0 to 3%.

(SO ₃ )
SO ₃ is a component that acts as a fining agent when melting glass. The content is 0 to 0.3%, more preferably 0.01 to 0.2%.

[Coloring ingredients]
The coloring components shown below are displayed in the mass ratio with respect to the denominator, with the mass of the basic glass composition described above as the denominator.

(iron oxide)
The iron oxide is expressed by total iron oxide converted to Fe ₂ O ₃ (sometimes expressed as [T-Fe ₂ O ₃ ]), and the content is less than 0.5%, the wavelength of 850 to 950 nm. Cannot absorb enough light. For this reason, near infrared rays are radiated through the glass substrate for display, and there is a possibility of causing trouble in infrared communication. Moreover, when the content rate of total iron oxide increases, this absorption becomes too large, and the visible light transmittance tends to be lowered, or the adjustment of the luminescent color tone tends to be difficult. In particular, if it exceeds 5.5%, the visible light transmittance is too low to be practical as a glass substrate, and it is difficult to adjust the emission color tone. The content of total iron oxide is preferably as small as possible from the viewpoint of securing the visible light transmittance as long as it contains a ratio that can sufficiently absorb light with a wavelength of 850 to 950 nm. Accordingly, the total iron oxide content is 0.5 to 5.5%, preferably 0.5 to 3%, and more preferably 0.5 to 2%.

Furthermore, when this glass composition does not substantially contain Se described in detail later, the mass ratio of FeO converted to Fe ₂ O ₃ and the total iron oxide is [FeO / T—Fe ₂ O ₃ ]. In this case, the ratio is preferably in the range of 0.2 to 0.5. Since this does not contain Se, [FeO / T—Fe ₂ O ₃ ] is adjusted in order to complement the absorption by this.

Furthermore, when this glass composition does not substantially contain NiO which will be described in detail later, the mass ratio of FeO converted to Fe ₂ O ₃ and the total iron oxide is [FeO / T—Fe ₂ O ₃ ]. The ratio is preferably in the range of 0.25 to 0.5. Since this does not contain NiO, [FeO / T—Fe ₂ O ₃ ] is adjusted in order to complement the absorption by this.

(CoO)
When the content of CoO is less than 50 ppm, light having a wavelength of 500 to 700 nm is not sufficiently absorbed. For this reason, it colors in green and it becomes difficult to adjust the light emission color tone. On the other hand, if the content exceeds 400 ppm, the visible light transmittance is too low. Therefore, the content of CoO is 50 to 400 ppm.

(NiO, Se)
When NiO is added alone, if its content is less than 100 ppm, absorption near 460 nm is insufficient, and adjustment of the emission color tone becomes difficult. On the other hand, when the content exceeds 800 ppm, absorption near 460 nm is remarkable, lowering the emission luminance, and at the same time shortening the lifetime of the blue phosphor with relatively weak emission. Therefore, the content of NiO is 100 to 800 ppm, preferably 400 to 800 ppm.

  When Se is added alone, if its content is less than 1 ppm, absorption near 460 nm is insufficient, and it becomes difficult to adjust the emission color tone. On the other hand, if the content exceeds 20 ppm, the absorption near 460 nm becomes excessively high, and the lifetime of the blue phosphor with relatively weak emission is shortened at the same time as lowering the emission luminance. Therefore, the content of Se is 1 to 20 ppm, and preferably 10 to 20 ppm.

  NiO and Se have the same effect with respect to absorption at around 460 nm, and when NiO and Se are added simultaneously, the effect is so great that absorption near 460 nm may be too large. . It was revealed that Se has a larger absorption capacity near 460 nm, which is about 40 times that of NiO.

Therefore, when NiO and Se are added simultaneously, it is preferable to satisfy the following relationship. That is, when the mass ratios of NiO and Se expressed in ppm are [NiO] and [Se], respectively, the NiO and Se are
100 ≦ 40 × [Se] + [NiO] ≦ 800
Add so that it falls within the range. Furthermore, the NiO and the Se,
400 ≦ 40 × [Se] + [NiO] ≦ 800
It is preferable to add so that it may exist in this range.

In addition, in this invention, a coloring component shall contain only the component mentioned above substantially. In particular, Nd ₂ O ₃ is not included.

  Within such a range, it is possible to adjust the color tone to be preferable as a glass substrate for display after effectively absorbing near infrared rays.

  In the glass substrate for a display according to the present invention, the visible light transmittance measured using a C light source when the thickness is set to any one of 1.0 to 2.8 mm is 40 to 70% by using such a composition. It can be. Furthermore, the transmittance of light having a wavelength of 910 nm can be made 40% or less.

  When the visible light transmittance of the glass substrate is 40 to 70%, high contrast can be secured while maintaining the luminance necessary for the display device. It is also possible to prevent the black display from being colored.

In the glass substrate for display according to the present invention, a ^* and b ^* represented by L ^* a ^* b ^* color system defined by JIS Z 8729 are respectively −10 ≦ a ^* ≦ 5, −10 ≦ b ^* ≦ 5. Further, the a ^* and b ^* are preferably in the range of −7 ≦ a ^* ≦ 2, −5 ≦ b ^* ≦ 2, respectively. For this reason, as a glass substrate for a display, it is possible to obtain a neutral and gray color tone with which the emission color tone can be easily adjusted. The color tone at this time is a transmission color tone.

  As described above, according to the configuration of the present invention, it is possible to provide a glass substrate for display which can easily adjust the light emission color tone and obtain a high contrast, particularly when applied to a plasma display device. In addition, since the near-infrared absorptivity is excellent, the near-infrared light accompanying plasma emission is sufficiently suppressed, and there is no possibility of causing trouble in infrared communication.

Hereinafter, examples and comparative examples will be described.
In Examples and Comparative Examples, the basic glass composition shown in Table 1 is set to 100 parts by mass, the coloring components shown in Table 2 are added at a mass ratio with respect to the parts by mass, the raw materials are prepared, and this is added to the platinum crucible. After putting, it was melted in an electric furnace at a temperature of 1550 ° C. for 4 hours, and then this molten glass was poured out onto a stainless steel plate and formed into a plate shape. A glass substrate obtained by appropriately annealing this was polished to various thicknesses to prepare samples for measuring optical characteristics. In addition, [FeO / T-Fe ₂ O ₃ ] in Table 2 was measured by chemical analysis.

(Table 1)
Basic glass composition (mass%)
────────────
SiO ₂ 61.6
Al ₂ O ₃ 3.1
Na ₂ O 2.0
K ₂ O 10.2
MgO 7.0
CaO 3.7
SrO 11.9
ZrO ₂ 0.4
SO ₃ 0.1
────────────

When the strain point and thermal expansion coefficient in the glass composition having the basic glass composition shown in Table 1 were measured, it was as follows.
Strain point: 577 ° C. ± 2 ° C., coefficient of thermal expansion: (83 ± 2) × 10 ⁻⁷ / K
These values are particularly preferable as a glass substrate for plasma display.
The glass substrate according to the present invention further contains a coloring component. However, since the addition ratio is small, it has substantially the same value as the strain point and thermal expansion coefficient described above.

  In addition, the basic glass composition shown in Table 1 is an example which represents the basic glass composition in this invention, and is not restricted to this.

(Table 2)
────────────────────────────────────────
Real 1 Real 2 Real 3 Real 4 Real 5 Real 6 Real 7 Real 8
────────────────────────────────────────
CoO (ppm) 120 210 100 140 50 130 70 100
NiO (ppm)----500 780 400 500
Se (ppm) 12 15 14 15----
Fe ₂ O ₃ (%) 0.8 1.1 0.5 0.7 0.6 1.3 0.6 0.95
FeO / [T-Fe ₂ O ₃ ] (%) 0.35 0.4 0.36 0.4 0.37 0.33 0.28 0.29
────────────────────────────────────────
──────────────────────────────────────
Real 9 Real 10 Real 11 Real 12 Ratio 1 Ratio 2 Ratio 3
──────────────────────────────────────
CoO (ppm) 120 180 100 250 100 10 400
NiO (ppm) 250 300--500-900
Se (ppm) 7 10 3 12 0 15 30
Fe ₂ O ₃ (%) 0.5 0.9 0.5 1.5 1.2 0.7 0.6
FeO / [T-Fe ₂ O ₃ ] (%) 0.36 0.4 0.36 0.4 0.1 0.4 0.37
──────────────────────────────────────

Examples 1-4 are glass compositions in which Se, CoO, and Fe ₂ O ₃ were added as coloring components, and the value of [FeO / T—Fe ₂ O ₃ ] was adjusted. Yes.

Examples 5 to 8 are glass compositions in which NiO, CoO, and Fe ₂ O ₃ are not added as coloring components, and the value of [FeO / T—Fe ₂ O ₃ ] is adjusted. Yes.

Examples 9 and 10 are glass compositions in which Se and NiO are simultaneously added as coloring components and CoO and Fe ₂ O ₃ are further added. Further, the value of [FeO / T—Fe ₂ O ₃ ] is obtained. Is adjusted.

Example 11 is a glass composition not containing NiO and containing a relatively small amount of Se, and the value of [FeO / T—Fe ₂ O ₃ ] is adjusted.

Example 12 is a glass composition that does not contain NiO and to which Se, CoO, and Fe ₂ O ₃ are added, and the value of [FeO / T—Fe ₂ O ₃ ] is adjusted.

In the comparative example 1, in the iron oxide added as a coloring component, the mass ratio [FeO / T-Fe ₂ O ₃ ] of FeO converted to Fe ₂ O ₃ and the total iron oxide is 0.1. Composition.
In Comparative Example 2, the content of CoO added as a coloring component is outside the scope of the claims of the present invention.
In Comparative Example 3, the contents of CoO, NiO, and Se added as coloring components are outside the scope of the claims of the present invention.

With respect to the sample thus prepared, the transmittance was measured as optical characteristics in the visible light region and near infrared ray, and the results are shown in Table 3.

(Table 3)
────────────────────────────────────────
Real 1 Real 2 Real 3 Real 4 Real 5 Real 6 Real 7 Real 8
────────────────────────────────────────
Thickness (mm) 1.8 1.8 2.8 2.8 1.8 1.8 2.8 2.8
---------------------------------------
910 nm transmittance 38 23 38 23 40 21 40 19
a ^* -0.67 -0.63 0.19 -0.09 -2.4 -6.04 -2.68 -5.9
b ^* 0.27 0.14 -0.9 -0.73 0.3 0.11 -0.46 -0.85
Visible light transmittance 57 41 52 41 63 45 55 42
────────────────────────────────────────
──────────────────────────────────────
Real 9 Real 10 Real 11 Real 12 Ratio 1 Ratio 2 Ratio 3
──────────────────────────────────────
Thickness (mm) 2.8 1.8 2.8 1.0 2.8 2.8 1.8
------------------------------------
910 nm transmittance 35 26 36 31 44 23 43
a ^* -2.6 -2.6 -2.7 -1.7 -5.2 -0.94 0.83
b ^* 1.6 0.02 -9.13 -0.4 7.6 12.69 2.63
Visible light transmittance 48 45 61 53 47 55.5 24
──────────────────────────────────────

As is apparent from Table 3, in Examples 1 to 12 within the scope of claims of the present invention, the thickness of 910 nm measured using a C light source at each thickness of 1.0, 1.8, and 2.8 mm. A glass substrate having optical characteristics of a transmittance of 40% or less and a visible light transmittance of 40 to 63% was obtained. The color tone represented by a ^* and b ^* was within the range of −10 ≦ a ^* ≦ 5, −10 ≦ b ^* ≦ 5.
In the above examples, the display glass substrate has a necessary visible light transmittance and a neutral color tone while maintaining a low transmittance at a wavelength of 910 nm.

In Examples 1 to 4, since Ni was not included as a coloring component and Se was added so as to be appropriate, both a ^* and b ^* were close to 0 regardless of the thickness of the substrate. . When this glass substrate is used as a glass substrate for a display, it is easy to adjust color development as a display device.

In Examples 5 to 8, since Se is not included as a coloring component and NiO is added so as to be appropriate, a ^* is slightly negative and greenish, but b ^* is Since it was close to 0, a glass substrate with a nearly neutral color tone could be realized.

Examples 9 and 10 are glass compositions in which two coloring components of Se and NiO are added in a range of 400 ≦ 40 × [Se] + [NiO] ≦ 800. By setting such a composition range, a glass substrate having a neutral color tone with a ^* and b ^* close to 0 could be realized.

  In Example 11, as a coloring component, NiO was not contained, and Se added was relatively small. Therefore, although the color tone was slightly bluish, a glass substrate having an almost neutral color tone could be realized.

Since Example 12 does not contain NiO as the coloring component and the added Se is 12 ppm, the range is 400 ≦ 40 × [Se] + [NiO] ≦ 800. As a result, a glass substrate having a neutral color tone with a ^* and b ^* close to 0 was realized.

On the other hand, in Comparative Example 1, [FeO / T—Fe ₂ O ₃ ] is as small as 0.1. For this reason, b ^* was outside the range specified in the present invention, and the yellow color of the glass substrate was too strong. When this glass substrate is used as a glass substrate for a display, it is difficult to adjust color development as a display device.

  Comparative Example 2 is a glass substrate that is too yellow due to the low CoO content of 10 ppm. Therefore, although near infrared rays can be absorbed, a load is applied to the blue phosphor and its lifetime is shortened.

  Since the comparative example 3 has too much addition amount of a coloring component, visible light transmittance | permeability is too low with 24%. For this reason, it is difficult to use as a glass substrate for a display.

Claims (5)

Expressed in mass proportion, the basic glass composition is substantially
SiO ₂ 55~65%,
Al ₂ O ₃ 1-12%,
Na ₂ O 0-5%,
K ₂ O 5-15%,
MgO 1-15%,
CaO 1-12%,
SrO 5-20%,
BaO 0-10%,
ZrO ₂ 0-5%,
SO ₃ 0 to 0.3%,
Consisting of
As a coloring component, the mass of the basic glass composition is used as a denominator, and expressed as a mass ratio with respect to the denominator.
Total iron oxide [T-Fe ₂ O _3] and a 0.5 to 5.5% with terms of Fe ₂ O _3,
CoO is 50 to 400 ppm,
When the mass ratio of NiO and Se expressed in ppm is [NiO] and [Se], respectively, the NiO and Se are:
100 ≦ 40 × [Se] + [NiO] ≦ 800
It is a glass substrate for display using a glass composition added so as to be in the range of
When the thickness of the substrate is 1.0 to 2.8 mm, the visible light transmittance measured using a C light source is 40 to 70%, and L ^* a ^* defined by JIS Z 8729 A glass substrate for a display, wherein a ^* and b ^* expressed in the b ^* color system are in a range of −10 ≦ a ^* ≦ 5 and −10 ≦ b ^* ≦ 5, respectively. The glass substrate for display according to claim 1,
The NiO and Se are
400 ≦ 40 × [Se] + [NiO] ≦ 800
It is added to be within the range of
A glass substrate for display in which a ^* and b ^* are in the range of −7 ≦ a ^* ≦ 2, −5 ≦ b ^* ≦ 2, respectively. In the glass substrate for a display according to claim 1 or 2,
The basic glass composition is substantially
SiO ₂ 55~62%,
Al ₂ O ₃ 2-6%,
Na ₂ O 0-5%,
K ₂ O 8-12%,
MgO 1-15%,
CaO 2-5%,
SrO 8-15%,
BaO 0 to 1%,
ZrO ₂ 0 to 3%,
SO ₃ 0.01 to 0.2%,
A glass substrate for display comprising the above components. In the glass substrate for a display according to any one of claims 1 to 3,
The glass composition does not substantially contain Se, and when the mass ratio of FeO converted to Fe ₂ O ₃ and the total iron oxide is [FeO / T—Fe ₂ O ₃ ], the ratio is 0. A glass substrate for display in the range of 2 to 0.5. In the glass substrate for a display according to any one of claims 1 to 3,
The glass composition does not substantially contain NiO, and when the mass ratio of FeO converted to Fe ₂ O ₃ and the total iron oxide is [FeO / T—Fe ₂ O ₃ ], the ratio is 0. A glass substrate for display in the range of 25 to 0.5.