JP6919652B2 - UV absorbing glass - Google Patents

Description

The present invention relates to an ultraviolet absorbing glass suitable as a dark gray color glass for vehicles (particularly for automobiles).

As the rear side glass and rear glass of automobile glass, dark gray glass (so-called dark gray glass or privacy glass) having significantly reduced visible light transmittance has been put into practical use. This privacy glass has a high sun-shielding performance in a wide wavelength range from the ultraviolet region to the infrared region, which makes it possible to reduce the comfort of the room, reduce the air-conditioning load, and select a color tone that gives a sense of luxury. It is excellent in terms of sex, privacy protection in the car, etc.

In recent years, there has been increasing interest in UV protection. In order to cope with this, privacy glass having a lower ultraviolet transmittance (TUV) is required. Patent Document 1 discloses an ultraviolet-absorbing glass suitable as a privacy glass for vehicles, which has an extremely low ultraviolet transmittance (TUV) of 2% or less at a plate thickness of 3.5 mm.

International Publication No. 2015/088026

In recent years, vehicle privacy glass is required to achieve extremely low ultraviolet transmittance and improve the color of the scenery seen through the glass. For example, it may be required to improve the color of human skin seen through glass. For that purpose, it is conceivable to improve the color playability of skin color (meaning human skin color, particularly Japanese skin color; the same applies in the following description of the present specification).

An object of the present invention is to provide an ultraviolet absorbing glass which is suitable as a dark gray color glass for vehicles, has an extremely low ultraviolet transmittance, and has excellent color rendering properties related to skin color, in order to cope with the above problems. do.

In order to achieve the above object, the present invention is expressed in mass% based on oxides.
SiO ₂ 66-75%,
Na ₂ O 10-20%,
CaO 5-15%,
MgO 0-6%,
Al ₂ O ₃ 0~5%,
K ₂ O 0-5%,
Fe ₂ O ₃ 1.0 to 3.0%,
FeO 0.2-0.8%,
TiO ₂ 0.15-4.0%,
CoO 0.01-0.04%,
Se 0.005% or less,
Cr ₂ O ₃ 0.04% or less,
NiO 0.2% or less,
Containing, in terms of the redox _([Fe 2 _O content of ₃ divalent iron in terms of ^{(Fe 2+)]} / [bivalent iron as calculated as ^_Fe 2 _{O 3 (Fe} ²⁺⁾ and _Fe 2 _{O 3} three Total content of iron (Fe ³⁺ )]) is 10-40%,
The ultraviolet transmittance (TUV) specified in ISO 9050: 2003 at a plate thickness of 2.8 mm is 2% or less.
The visible light transmittance (TVA) based on the standard A light source at a plate thickness of 2.8 mm is 8% or more and 28% or less.
The energy transmittance (TE) specified by JIS R 3106: 1998 at a plate thickness of 2.8 mm is 28% or less.
Provided is an ultraviolet absorbing glass having a color rendering index ratio R15 of 80 or more and R15 / R4 of 1.11 or more specified in ISO 9050: 1990 and JIS Z8726: 1990.

The ultraviolet-absorbing glass of the present invention can achieve extremely low ultraviolet transmittance and can improve the color of human skin seen through the glass. The ultraviolet absorbing glass of the present invention is particularly preferable as a rear side glass, a rear glass, a roof glass and the like for automobiles.

The ultraviolet-absorbing glass of the present invention is indicated by mass% based on oxides.
SiO ₂ 66-75%,
Na ₂ O 10-20%,
CaO 5-15%,
MgO 0-6%,
Al ₂ O ₃ 0~5%,
K ₂ O 0-5%,
Fe ₂ O ₃ 1.0 to 3.0%,
FeO 0.2-0.8%,
TiO ₂ 0.15-4.0%,
CoO 0.01-0.04%,
Se 0.005% or less,
Cr ₂ O ₃ 0.04% or less,
NiO 0.2% or less,
Containing, in terms of the redox _([Fe 2 _O content of ₃ divalent iron in terms of ^{(Fe 2+)]} / [bivalent iron as calculated as ^_Fe 2 _{O 3 (Fe} ²⁺⁾ and _Fe 2 _{O 3} three Total content of iron (Fe ³⁺ )]) is 10-40%,
The ultraviolet transmittance (TUV) specified in ISO 9050: 2003 at a plate thickness of 2.8 mm is 2% or less.
The visible light transmittance (TVA) based on the standard A light source at a plate thickness of 2.8 mm is 8% or more and 28% or less.
The energy transmittance (TE) specified by JIS R 3106: 1998 at a plate thickness of 2.8 mm is 28% or less.
It is an ultraviolet absorbing glass having a color rendering index ratio R15 of 80 or more and R15 / R4 of 1.11 or more specified in ISO 9050: 1990 and JIS Z8726: 1990.

The above-mentioned "~" indicating the numerical range is used to mean that the numerical values described before and after the above are included as the lower limit value and the upper limit value, and unless otherwise specified, the "~" in the present specification is the same. It is used with the meaning of.

In the present invention, the reason for using the above components will be described below. Unless otherwise specified, "%" representing the content of each component shall mean the mass% based on the oxide.

SiO ₂ is a component that constructs a network and is an essential component. When _{the content of SiO 2} is 66% or more, the weather resistance becomes good, and when the content is 75% or less, the viscosity does not become too high, which is convenient for melting. 67% or more is preferable. Further, 72% or less is preferable, and 70% or less is more preferable.

Na ₂ O is a component that promotes melting of raw materials and is an essential component. When _{the content of Na 2} O is 10% or more, the melting of the raw material is promoted, and when the content is 20% or less, the weather resistance is not deteriorated. 11% or more is preferable, and 12% or more is more preferable. Further, 18% or less is preferable, and 16% or less is more preferable.

CaO is a component that promotes melting of raw materials and improves weather resistance, and is an essential component. When the content of CaO is 5% or more, the melting of the raw material is promoted to improve the weather resistance, and when the content is 15% or less, devitrification is suppressed. 6% or more is preferable, and 7% or more is more preferable. 13% or less is preferable, and 11% or less is more preferable.

MgO is a component that promotes melting of raw materials and improves weather resistance, and is a selective component. MgO suppresses devitrification when the content is 6% or less. 5% or less is preferable, 4.6% or less is more preferable, and 4% or less is further preferable. When MgO is contained, the content of MgO is preferably 1% or more, more preferably 2% or more, and even more preferably 3% or more.

Al ₂ O ₃ is a component that improves weather resistance and is a selective component. If _{the content of Al 2} O ₃ is 5% or less, the viscosity does not become too high, which is convenient for melting. 4% or less is preferable, and 3% or less is more preferable. When Al ₂ O ₃ is contained, the content of Al ₂ O ₃ is preferably 0.5% or more, and more preferably 1% or more.

K ₂ O is a component that promotes melting of the raw material and is a selective component. If _{the content of K 2} O is 5% or less, it suppresses damage to the refractory of the molten kiln due to volatilization. 4% or less is preferable, 3% or less is more preferable, and 2% or less is further preferable. When K ₂ O is contained, the content of K ₂ O is preferably 0.1% or more, and more preferably 0.3% or more.

_{Fe 2} O _3, which is an oxide of ferric iron, is a component that absorbs ultraviolet rays and is an essential component. It is also a component that causes the glass to become yellowish. If _{the content of Fe 2} O ₃ is lower than 1.0%, the ultraviolet transmittance becomes too large, so the content is set to 1.0% or more. If the content is too large, the visible light transmittance becomes too small, so the content should be 3.0% or less. The Fe ₂ O ₃ content is more preferably 1.2% or more, further preferably 1.4% or more, and particularly preferably 1.5% or more. The Fe ₂ O ₃ content is more preferably 2.8% or less, further preferably 2.4% or less, and particularly preferably 2.2% or less.

FeO, which is an oxide of ferrous iron, is a component that absorbs heat energy and is an essential component. If the content of FeO is 0.2% or more, a sufficiently low energy transmittance can be obtained. On the other hand, if the content is 0.8% or less, the thermal efficiency at the time of melting does not deteriorate, and the retention of the substrate at the bottom of the melting furnace far from the heating source is suppressed. 0.25% or more is preferable, 0.30% or more is more preferable, 0.35% or more is further preferable, and 0.40% or more is particularly preferable. Further, 0.7% or less is preferable, 0.65% or less is more preferable, and 0.6% or less is further preferable.

The UV absorbing glass of the present invention, as an index of the balance of the visible light transmittance and energy transmission, [content of divalent iron in terms of ^{_{Fe 2 O 3 (Fe 2+)}} ] Redox (/ _[Fe 2 _{O 3} The total content of ferrous iron (Fe ²⁺ ) _{converted to Fe 2} O ₃ and ferric iron (Fe ³⁺ ) converted to Fe 2 O 3]) is used.

The UV-absorbing glass of the present invention has a redox content of 10 to 40%. If the redox is 10% or more, the energy transmittance is not too large, and if it is 40% or less, the visible light transmittance is not too small. The ultraviolet-absorbing glass of the present invention preferably has a redox content of 15% or more, more preferably 20% or more. Further, 35% or less is preferable, 30% or less is more preferable, and 25% or less is further preferable.

TiO ₂ is a component that reduces the ultraviolet transmittance (TUV) and is an essential component. Further, TiO ₂ has an effect of lowering the viscosity of the base material at the time of melting, and has a function of making it difficult for the base material to stay. If the content is lower than 0.15%, the ultraviolet transmittance becomes too large, so the content is set to 0.15% or more. Further, when _{the content of TiO 2} is 0.15% or more, R15 and R15 / R4 can be increased. The content of TiO ₂ is preferably 0.5% or more, more preferably 1.0% or more, further preferably more than 1.0%, particularly preferably 1.2% or more, and most preferably 1.5% or more. .. However, _{if the content of TiO 2} is too large, the visible light transmittance becomes too small, so the content is set to 4.0% or less. 3.5% or less is preferable, 3.0% or less is more preferable, and 2.8% or less is further preferable.

CoO is a component that makes glass bluish and is an essential component. When the content of CoO is 0.01% or more, the color tone of the glass is suppressed from becoming yellowish, and when the content is 0.04% or less, the visible light transmittance (TVA) is not too low. Further, if the CoO content is 0.04% or less, R15 and R15 / R4 can be increased. The more preferable CoO content is 0.011% or more, the more preferable CoO content is 0.012% or more, and the particularly preferable CoO content is 0.013% or more. Further, the more preferable CoO content is 0.038% or less, the more preferable CoO content is 0.036% or less, and the particularly preferable CoO content is 0.033% or less. The most preferable CoO content is 0.030% or less.

Se is not required, but can be contained for adjusting the color of the glass. If Se is 0.005% or less, it suppresses yellowing. In addition, there is little effect of redness. 0.004% or less is more preferable, 0.0035% or less is further preferable, and 0.003% or less is particularly preferable. When Se is contained, the content of Se is preferably 0.0001% or more. When the content of Se is 0.0001% or more, R15 and R15 / R4 can be increased. The content of Se is more preferably 0.0002% or more, further preferably 0.0003% or more, and particularly preferably 0.0005% or more.

Cr ₂ O ₃ is a component that reduces the visible light transmittance in the ultraviolet-absorbing glass of the present invention, and is also a component that causes the glass to become greenish, and is an optional component. When Cr ₂ O ₃ is contained, the content is preferably 0.005% or more, more preferably 0.008% or more, further preferably 0.01% or more, particularly preferably more than 0.01%, and 0. 012% or more is most preferable. Further, Cr ₂ O ₃ suppresses the visible light transmittance from becoming too small when the content is 0.04% or less. Further, when _{the content of Cr 2} O ₃ is 0.04% or less, R15 and R15 / R4 do not become too small. The content of Cr ₂ O ₃ is preferably 0.035% or less, more preferably 0.03% or less, and particularly preferably 0.025% or less.

NiO is an optional component that can make the glass brownish in the ultraviolet-absorbing glass of the present invention. If it is 0.2% or less, the brownness does not become too strong. The NiO content is preferably 0.17% or less, more preferably 0.15% or less, further preferably 0.10% or less, particularly preferably 0.07% or less, particularly preferably 0.06% or less, and 0. Most preferably, it is 05% or less.

The ultraviolet absorbing glass of the present invention has _{a total iron content converted to Fe 2} O ₃ (that is, a total iron containing Fe O, which is an oxide of ferrous iron, and Fe _{2 O 3} which is an oxide of ferric iron. The content (hereinafter, _{also referred to as t-Fe 2} O ₃ ) is preferably 1.5% or more. If it is 1.5% or more, the ultraviolet transmittance (TUV380 and TUV400) can be lowered. In addition, the main wavelength (λD) can be lengthened. Further, R15 and R15 / R4, which will be described later, can be increased. The content of t-Fe ₂ O ₃ is more preferably 1.8% or more, more preferably 1.9% or more, further preferably 2.1% or more, particularly preferably 2.4% or more, and 2.5%. The above is the most preferable.

The content of t-Fe ₂ O ₃ is preferably 5.0% or less. If t-Fe ₂ O ₃ is 5.0% or less, TVA does not become too low. Further, when t-Fe ₂ O ₃ is 5.0% or less, the thermal efficiency at the time of melting does not deteriorate, and the substrate is suppressed from staying at the bottom of the melting furnace far from the heating source, so that the solubility is good. .. t-Fe ₂ O ₃ is more preferably 4.0% or less, further preferably 3.0% or less, and particularly preferably 2.9% or less.

In the ultraviolet-absorbing glass article of the present invention, the greenness of the glass is strong when the contents of _{Fe 2} O ₃ , FeO, TiO ₂ , CoO, Se, Cr ₂ O _{3 and NiO satisfy the following formula (a).} It is possible to prevent it from becoming too much.
-0.0398-0.002 x [Fe ₂ O ₃ ] + 0.097 x [FeO] + 0.0019 x [TiO ₂ ] + 0.95 x [CoO] -21.16 x [Se] + 0.66 x [ Cr ₂ O ₃ ] −0.030 × [NiO] <0 (a)
In the formula (a), the indication of the component enclosed in square brackets is the content of the component expressed in mass% of the oxide standard contained in the ultraviolet absorbing glass (the following description of the present specification). Same in).

In actual production, since a clarifying agent such as Glauber's salt is used, SO ₃ of usually 0.05 to 0.5%, preferably 0.05 to 0.4% is contained in the glass as a trace thereof. It's okay.

In addition to the above, the ultraviolet absorbing glass of the present invention may contain oxides of B, Ba, Sr, Li, Zn, Pb, P, Zr, Bi and Sn. The content of each of these oxides may be 0 to 1% by mass. The total amount of these components is preferably 1% or less, more preferably 0.7% or less, further preferably 0.4% or less, particularly preferably 0.2% or less, and most preferably 0.1% or less. But it may be.

It may also contain oxides of Sb or As, Cl or F. These can be intentionally mixed from the melting aids and clarifying agents. Alternatively, it may be contained as an impurity in a raw material or cullet. Each of these contents may be preferably 0 to 0.1% by mass, more preferably 0 to 0.05% by mass, and further preferably 0 to 0.01% by mass.

Further, each oxide of Mn, Cu, Mo, Nd and Er may be contained. The content of these oxides (MnO ₂ , CuO, MoO ₃ , Nd ₂ O ₃ , Er ₂ O ₃ ) may be preferably 0 to 0.1% by mass, and more preferably 0 to 0. It may be 05% by mass, more preferably 0 to 0.01% by mass.

Further, the ultraviolet-absorbing glass article of the present invention may contain _{CeO 2 in order to reduce the ultraviolet transmittance (TUV).} When CeO ₂ is contained, _{the content of CeO 2} may be 0 to 1% by mass. CeO ₂ may be contained preferably 0.7% by mass or less, more preferably 0.4% by mass or less, still more preferably 0.2% by mass or less, and particularly preferably 0.1% by mass or less. It is preferable that CeO ₂ is substantially not contained in order to reduce the raw material cost. Here, substantially not contained means that unavoidable impurities are excluded and not contained, and specifically in the present invention, it means that _{the content of CeO 2} is 100 ppm or less in the glass.

It is preferable that V and W oxides (V ₂ O ₅ , WO ₃ ) are substantially not contained. Here, substantially not contained means that unavoidable impurities are excluded, and specifically, the content of these oxides is 100 mass ppm or less in the glass.

The ultraviolet-absorbing glass of the present invention is a glass having the above composition and has the following optical characteristics.

The ultraviolet transmittance (TUV) at a plate thickness of 2.8 mm is 2% or less, preferably 1% or less, more preferably 0.5% or less, still more preferably 0.3% or less.

Further, the visible light transmittance (TVA) at a plate thickness of 2.8 mm is 8% or more and 28% or less. 10% or more is preferable, and 12% or more is more preferable. Further, 24% or less is preferable, and 20% or less is more preferable.

Further, in addition to the above optical characteristics, the ultraviolet transmittance (TUV400) at a plate thickness of 2.8 mm is preferably 5% or less, more preferably 3% or less, still more preferably 2% or less.

Further, in addition to the above optical characteristics, the energy transmittance (TE) is 28% or less, preferably 24% or less, more preferably 20% or less, still more preferably 16% or less.

Throughout this specification, the energy transmittance is determined by JIS R 3106: 1998, the ultraviolet transmittance is determined by ISO 9050: 2003, and the ultraviolet transmittance (TUV400) is determined by ISO 13837: 2008 conference A. The visible light transmittance (TVA) is calculated based on the standard A light source.

Further, the ultraviolet absorbing glass of the present invention has a color rendering index ratio R15 of 80 or more specified in ISO 9050: 1990 and JIS Z8726: 1990 in order to improve the color rendering property related to skin color in addition to the above optical characteristics. And R15 / R4 is 1.11 or more. The test color 15 represents the skin color of Japanese people, and the Munsell value is 1YR6 / 4. The test color 4 represents a greenish color that is the opposite color of the skin color in the hue circle defined in ISO 9050: 1990 and JIS Z8721: 1993, and has a Munsell value of 2.5G6 / 6.

When R15 is 80 or more and R15 / R4 is 1.11 or more, in the present invention, green color development is suppressed while improving skin color development, color rendering property related to skin color is improved, and it is visible through glass. The color rendering of human skin can be improved, and human skin can be expressed obediently. R15 is preferably 80 or more, more preferably 85 or more. R15 / R4 is preferably 1.13 or more.

By _{reducing the content of Cr 2} O ₃ or CoO, R15 and R15 / R4 can be increased. Further, R15 and R15 / R4 can be increased by increasing the content of t-Fe ₂ O ₃ or TiO _2.

Further, in the ultraviolet absorbing glass of the present invention, when the value represented by the following formula (1) is A and the value represented by the following formula (2) is B, the B / A is preferably 1.11 or more. ..
4.86 x [Fe ₂ O ₃ ] -38.62 x [FeO _{] +4.62 x [TIO 2} ] 31.34 x [NiO] -278.51 x [Cr ₂ O ₃ ] -280.43 x [CoO] +5964.52 x [Se] -749.02 x [TiO ₂ ] x [Se] -2.41 x [Fe ₂ O ₃ ] x [TiO ₂ ] +90.24 (1)
7.58 × [Fe ₂ O ₃ ] -41.02 × [FeO] + 6.78 × [TiO ₂ ] −0.33 × [NiO] -213.83 × [Cr ₂ O ₃ ] −511.68 × [CoO] +1127.37 x [Se] -1701.77 x [TiO ₂ ] x [Se] -1.02 x [Fe ₂ O ₃ ] x [TiO ₂ ] +82.93 (2)
A is an index of R4 of the ultraviolet absorbing glass, and B is an index of R15. In the ultraviolet absorbing glass of the present invention, in order to set R15 / R4 to 1.11 or more, B / A is preferably 1.11 or more, and more preferably 1.13 or more.

Further, the ultraviolet absorbing glass of the present invention preferably has a B of 80 or more. In the ultraviolet absorbing glass of the present invention, in order to set R15 to 80 or more, B is preferably 80 or more, more preferably 85 or more.

Further, the ultraviolet absorbing glass of the present invention preferably has a plate thickness of 2.8 mm and a main wavelength λD of 590 nm or less. Here, the main wavelength λD is the main wavelength of the transmitted light specified in JIS Z 8701: 1999. λD is more preferably 585 nm or less, further preferably 580 nm or less, and particularly preferably 575 nm or less. Further, λD is preferably 520 nm or more. λD is more preferably 550 nm or more, further preferably 560 nm or more, particularly preferably 565 nm or more, and most preferably 570 nm or more.

Further, the ultraviolet-absorbing glass of the present invention preferably has a plate thickness of 2.8 mm and a stimulus purity Pe of 65% or less. Here, the stimulus purity Pe is the stimulus purity specified in JIS Z 8701: 1999. If Pe is 65% or less, the color becomes gray, which is closer to achromatic color. Pe is more preferably 60% or less, more preferably 55% or less, more preferably 50% or less, further preferably 45% or less, and particularly preferably 40% or less.

The ultraviolet absorbing glass of the present invention, preferably the temperature T2 at which the viscosity becomes 10 ² poise there is an effect that easier to manufacture of glass as long as 1440 ° C. or less. T2 is more preferably 1435 ° C. or lower, further preferably 1410 ° C. or lower, and particularly preferably 1400 ° C. or lower.

The method for producing the ultraviolet-absorbing glass of the present invention is not particularly limited, and for example, it can be produced as follows. The prepared raw materials are continuously supplied to the melting furnace and heated to about 1500 ° C. for vitrification. Next, after the molten glass is clarified, it is formed into a glass plate having a predetermined thickness by a float method or the like. Next, the ultraviolet-absorbing glass of the present invention is produced by cutting this glass plate into a predetermined shape. After that, if necessary, the cut glass can be subjected to strengthening treatment such as physical strengthening, processed into laminated glass, or processed into double glazing.

In the following, Examples 1 to 8 are Examples, and Examples 9 to 12 are Comparative Examples. A raw material batch was prepared using silica sand, feldspar, dolomite, soda ash, sardine, blast furnace slag, ferric oxide, titanium oxide, cobalt oxide, sodium selenate, chromium oxide, and nickel oxide as raw materials.

As a mother component, SiO ₂ : 66 to 70, Al ₂ O ₃ : 1.8, CaO: 8.4, MgO: 4.6, Na ₂ O: 13.3, K ₂ O: 0.7 and SO ₃ : Sodium lime silicate glass consisting of 0.2 (unit: mass% based on oxide) was used.

_{The SiO 2} content was adjusted so that the total of the mother component and Fe ₂ O ₃ , TiO ₂ , CoO, Se, Cr ₂ O ₃ and NiO added as optical components was 100% by mass to obtain the target composition. Batch platinum - Put the rhodium crucible, melted in an electric furnace (O ₂ concentration of 0.5% of an atmosphere), after poured on a carbon plate and slowly cooled in a separate electric furnace.

The obtained glass block was cut, a part was polished, and the composition was analyzed by a fluorescent X-ray analyzer (scanning type fluorescent X-ray analyzer ZSX100e manufactured by Rigaku Corporation). Another part of the surface was polished to a mirror surface and a thickness of 2.8 mm, and the spectral transmittance was measured with a spectrophotometer. FeO was calculated from the infrared transmittance at a wavelength of 1000 nm. Fe ₂ O ₃ was calculated based on the total iron oxide content by fluorescent X-ray analysis and the above FeO content.

Further, the value A represented by the equation (1) and the value B represented by the equation (2) were obtained according to the procedure described above.

In addition, the visible light transmittance (TVA), energy transmittance (TE), ultraviolet transmittance (TUV), ultraviolet transmittance (TUV400), main wavelength (λD), and stimulation purity (Pe) are determined based on the spectral transmittance. Calculated. Further, the color rendering indexes R4 and R15 for the test colors 4 and 15 for calculating the color rendering index were obtained by a method based on ISO9050: 1990 and JIS Z8726: 1990 based on the spectral transmittance.

The table below shows the content and optical characteristics of the absorbing components in the obtained glass.

As shown in Table 1, all of the glasses of Examples 1 to 8 satisfying all the requirements regarding the glass composition of the present invention satisfied the requirements regarding the optical characteristics at a plate thickness of 2.8 mm and the requirements regarding the color rendering property.

The glass of Example 9 having a Fe ₂ O ₃ content of less than 1.0% did not satisfy the color rendering index requirement R15 / R4 among the optical characteristics at a plate thickness of 2.8 mm. The glass of Example 10 having a Fe ₂ O ₃ content of less than 1.0% and a TiO ₂ content of less than 0.15% has energy transmittance (TE) and ultraviolet rays among the optical characteristics at a plate thickness of 2.8 mm. It did not meet the requirements R15 / R4 for transmittance (TUV) and color playability.

The glass of Example 11 having a Fe ₂ O ₃ content of less than 1.0%, a FeO content of less than 0.2%, and a CoO content of more than 0.04% has optical characteristics at a plate thickness of 2.8 mm. , The requirements for energy transmission (TE) and color playability R15 / R4 were not met. The glass of Example 12 having a Cr ₂ O ₃ content of more than 0.04% did not meet the color rendering requirements R15 and R15 / R4 among the optical properties at a plate thickness of 2.8 mm.

Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various modifications and modifications can be made without departing from the spirit and scope of the invention. This application is based on a Japanese patent application (Japanese Patent Application No. 2016-116944) filed on June 13, 2016, and the entire application is incorporated by reference. Also, all references cited here are taken in as a whole.

Claims (5)

In terms of oxide-based mass% display,
SiO ₂ 66-75%,
Na ₂ O 10-20%,
CaO 5-15%,
MgO 0-6%,
Al ₂ O ₃ 0~5%,
K ₂ O 0-5%,
Fe ₂ O ₃ 1.0 to 3.0%,
FeO 0.2-0.8%,
TiO ₂ 0.15-4.0%,
CoO 0.01-0.04%,
Se 0.005% or less,
Cr ₂ O ₃ 0.04% or less,
NiO 0.2% or less,
Redox ([Fe ₂ O ₃ converted divalent iron (Fe ²⁺ )] / [Fe ₂ O ₃ converted divalent iron (Fe ²⁺ ) and Fe ₂ O ₃ converted trivalent) Iron (Fe ³⁺ ) total]) is 10-40%,
The ultraviolet transmittance (TUV) specified in ISO 9050: 2003 at a plate thickness of 2.8 mm is 2% or less.
The visible light transmittance (TVA) based on the standard A light source at a plate thickness of 2.8 mm is 8% or more and 28% or less.
The energy transmittance (TE) specified by JIS R 3106: 1998 at a plate thickness of 2.8 mm is 28% or less.
ISO9050: 1990 and JIS Z8726: color rendering index of the ratio R15 defined in 1990 is not less than 80, and state, and are R15 / R4 is 1.11 or more,
When the value represented by the following formula (1) is A and the value represented by the following formula (2) is B, B is 80 or more and B / A is 1.11 or more. Absorbent glass. Here, the indication of the component enclosed in square brackets is the content of the component expressed in mass% representation based on the oxide contained in the ultraviolet absorbing glass.
4.86 x [Fe ₂ O ₃ ] -38.62 x [FeO _{] +4.62 x [TIO 2} ] 31.34 x [NiO] -278.51 x [Cr ₂ O ₃ ] -280.43 x [CoO] +5964.52 x [Se] -749.02 x [TiO ₂ ] x [Se] -2.41 x [Fe ₂ O ₃ ] x [TiO ₂ ] +90.24 (1)
7.58 x [Fe ₂ O ₃ ] -11.02 x [FeO] + 6.78 x [TiO ₂ ] -0.33 x [NiO] -213.83 x [Cr ₂ O ₃ ] -511.68 x [CoO] +1127.37 x [Se] -1701.77 x [TiO ₂ ] x [Se] -1.02 x [Fe ₂ O ₃ ] x [TiO ₂ ] +82.93 (2) The ultraviolet-absorbing glass according to claim 1, wherein the plate thickness is 2.8 mm, and the ultraviolet transmittance (TUV) specified in ISO 9050: 2003 is 1% or less. The ultraviolet-absorbing glass according to claim 1 or 2, wherein the ultraviolet-absorbing glass having a plate thickness of 2.8 mm and having an ultraviolet transmittance (TUV400) specified by ISO13837: 2008 combination A is 5% or less. The ultraviolet-absorbing glass according to any one of claims 1 to 3, which has a plate thickness of 2.8 mm and has a visible light transmittance (TVA) of 10 to 24% based on a standard A light source. The ultraviolet-absorbing glass according to any one of claims 1 to 4 , wherein the contents of Fe ₂ O ₃ , FeO, TiO ₂ , CoO, Se, Cr ₂ O ₃ and NiO satisfy the following formula (a). Here, the indication of the component enclosed in square brackets is the content of the component expressed in mass% representation based on the oxide contained in the ultraviolet absorbing glass.
-0.0398-0.002 x [Fe ₂ O ₃ ] + 0.097 x [FeO] + 0.0019 x [TiO ₂ ] + 0.95 x [CoO] -21.16 x [Se] + 0.66 x [ Cr ₂ O ₃ ] −0.030 × [NiO] <0 (a)