阅读说明：本技术 玻璃 (Glass ) 是由 池西干男 丹野义刚 于 2020-04-30 设计创作，主要内容包括：本发明的课题在于提供具有着色层的玻璃,该玻璃是具有着色层的玻璃。(The invention provides glass having a colored layer.)

1. A glass having a colored layer.

2. The glass according to claim 1, having a portion with a small transmittance and a portion with a large transmittance.

3. The glass according to claim 1 or 2, which contains Bi ions as a glass component.

4. A glass according to any one of claims 1 to 3 which is a phosphate glass.

5. The glass according to any one of claims 1 to 4, having a refractive index of 1.70 or more.

6. An optical element comprising the glass according to any one of claims 1 to 5.

Technical Field

The present invention relates to glass having a colored layer.

Background

Patent document 1 discloses an invention in which the transmittance of a glass is changed by heat-treating the glass in an oxidizing atmosphere or a non-oxidizing atmosphere. However, patent document 1 does not disclose forming a colored layer in glass.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2002-201041

Disclosure of Invention

Problems to be solved by the invention

The invention aims to provide glass with a colored layer.

Means for solving the problems

The gist of the present invention is as follows.

(1) A glass having a colored layer.

(2) The glass according to the above (1), which has a portion with a low transmittance and a portion with a high transmittance.

(3) The glass according to the above (1) or (2), which contains Bi ions as a glass component.

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

(5) The glass according to any one of (1) to (4) above, which has a refractive index of 1.70 or more.

(6) An optical element comprising the glass according to any one of the above (1) to (5).

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a glass having a colored layer can be provided.

Drawings

Fig. 1 is a schematic diagram showing an example of an embodiment of the present invention.

Fig. 2 is a schematic diagram showing an example of the embodiment of the present invention.

FIG. 3-1 is a schematic view showing an example of the embodiment of the present invention.

Fig. 3-2 is a schematic view for explaining the embodiment of fig. 3-1.

Fig. 4 is a schematic diagram showing an example of the embodiment of the present invention.

FIG. 5-1 is an image showing a sample of example 1-1 and a ruler for reference.

FIG. 5-2 is an image showing a sample of example 1-2 and a ruler for reference.

Fig. 6-1 is a graph showing the transmittance of the portion having the colored layer of the sample of example 1-1.

Fig. 6-2 is a graph showing the transmittance of the portion having the colored layer of the sample of example 1-2.

Fig. 6 to 3 are graphs showing the transmittance of the portions having colored layers of the samples of examples 1 to 3.

FIG. 7-1 is a graph showing the transmittance of a portion having a colored layer of the sample of example 2-1 in accordance with the film thickness of the metal film.

Fig. 7-2 is a graph showing the transmittance of the portion having a colored layer of the sample of example 2-2 according to the film thickness of the metal film.

FIG. 8 is a graph showing the relationship between the film thickness and OD of the metal films of the samples of examples 2-1 and 2-2 according to the heat treatment time.

Fig. 9 is an image showing a sample of example 5 and a ruler for reference.

Fig. 10 is a photomicrograph showing a cross section of a portion of the sample of example 7 having a colored layer.

FIG. 11 is a graph showing OD (wavelength 1100nm) when the removal amount in the thickness direction is plotted on the horizontal axis of the sample of example 7, and the numerical value in the graph is Δ OD.

FIG. 12 is a graph showing OD (wavelength 780nm) when the removal amount in the thickness direction is plotted on the horizontal axis of the sample of example 7, and the numerical value in the graph is Δ OD.

Description of the symbols

1: glass body

2: coloured layer

Detailed Description

In this embodiment, the glass of the present invention will be described based on the content ratio of each component expressed as cation%. Therefore, in the following, unless otherwise specified, "%" represents "% cation".

The cation% means a molar percentage where the total content of all the cation components is 100%. The total content is the total amount of the contents of the plural kinds of cationic components (including the case where the content is 0%). The cation ratio is a ratio of the content of each cation component expressed as cation% (including the total content of plural kinds of cation components).

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

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

Hereinafter, embodiments of the present invention will be described in detail.

The glass of the present embodiment has a colored layer. The colored layer is a portion colored by the glass, and preferably exists in a layer form from the surface of the glass inward.

In the glass of the present embodiment, the colored layer may be present so as to cover the entire surface of the glass (over the entire surface of the glass), or may be present so as to cover a part of the surface of the glass (over a part of the surface of the glass).

The colored layer is a portion having a small transmittance for light incident on the glass. Therefore, in the glass of the present embodiment, part or all of the light incident on the colored layer is absorbed in the light incident on the glass, and the intensity of transmitted light is attenuated compared with light not incident on the colored layer. That is, the glass of the present embodiment may have a portion with a small transmittance and a portion with a large transmittance.

In the glass of the present embodiment, the colored layer can be removed by grinding or polishing. In the glass of the present embodiment, the transmittance of the glass from which the colored layer is removed becomes higher than the transmittance of the glass from which the colored layer is not removed.

In the present embodiment, for example, when the glass has 2 surfaces facing each other, the colored layer 2 may be provided only on one surface side of the glass body 1 as shown in fig. 1, or may be provided on both surfaces side as shown in fig. 2.

Further, as shown in FIG. 3-1, by selectively forming a colored layer on the glass surface, light can be shielded in a portion having the colored layer and light can be transmitted in a portion not having the colored layer. Thus, for example, by forming the colored layer in a specific pattern shape, functions such as a glass slit, a diaphragm, and a pinhole can be provided.

Since the colored layer 2 is not present on the path a of the light in fig. 3-1, the light passes from one surface to the other surface. Since the colored layer 2 is present in the path B, light is absorbed by the colored layer 2, and since the colored layer 2 has the same composition as the non-colored portion, there is no refractive index difference in the glass, and there is no light reflection at the boundary between the colored layer 2 and the non-colored portion. In this case, regarding the transmission of light, the same effect as in the case where the colored layer 2 is provided over the entire thickness direction of the glass as shown in fig. 3-2 can be obtained. It is known that the relationship between the incident angle and the refraction angle is determined on the surface of glass by the refractive index of glass and the refractive index of a medium (for example, air) in contact with glass. The area of the glass surface where the colored layer is formed, the width of the slit, the aperture diameter, and the like can be determined in consideration of this relationship.

As described later, the glass of the present embodiment can be used for an optical element. The glass of the present embodiment is preferably an optical glass from the viewpoint of use in an optical element. However, the glass of the present embodiment is not limited to optical glass, since it can be used as an ornament, an exterior ornament of a small electronic device, or the like by utilizing the decorative property of the colored layer.

In the glass of the present embodiment, the glass component composition is the same in the colored layer and the non-colored portion. However, the valence of the glass component (cation) may be different between the colored layer and the non-colored portion.

The coloring of the colored layer is preferably a reduction color generated by a glass component, and more preferably a reduction color generated by a transition metal. Examples of the transition metal include Ti, Nb, W, and Bi. Therefore, the glass of the present embodiment preferably contains at least 1 kind of ion selected from Ti ions, Nb ions, W ions, and Bi ions, and more preferably contains Bi ions as a glass component.

(thickness of coloring layer)

The thickness of the colored layer is not particularly limited, but is preferably 1 to 300 μm, more preferably 20 to 200 μm, and further preferably 30 to 150 μm.

(OD)

In the glass of the present embodiment, the spectral transmittance of the colored layer in the wavelength range from the visible light range (wavelength range of 400nm to 760 nm) to the infrared light range tends to increase as the wavelength becomes longer. On the other hand, the OD of the colored layer tends to decrease as the wavelength becomes longer. OD is optical density or optical density (optical density) expressed by the following formula, and is expressed as incident light intensity I ₀The common logarithm of the ratio to the transmitted light intensity I is represented by a number with a negative sign added.

OD＝-log₁₀(I/I_o)

When the glass of the present embodiment is formed of the colored layer and the non-colored portion having a high transmittance in the visible light range, the OD of the colored layer is large, and the OD of the non-colored portion is small. In the measurement of the OD, when the measurement light passes through both the colored layer and the non-colored portion, the OD of the colored layer becomes dominant because the OD of the non-colored portion is small.

In the glass of the present embodiment, the OD of the portion having the colored layer at a wavelength of 1100nm is preferably 1.0 or more, more preferably 1.5 or more. On the other hand, the OD of the non-colored portion at a wavelength of 1100nm is preferably 0.15 or more, and more preferably 0.1 or less.

In general, the sensitivity range of an optical sensor such as a CCD or C-MOS sensor extends from the visible light region to around 1100 nm. By providing a colored layer having an OD in the above range, it is possible to obtain glass capable of shielding light over the entire sensitivity range of the optical sensor. Therefore, the glass of the present embodiment is preferably controllable in transmittance with respect to light in a wavelength range from the visible light range to 1100 nm.

In addition, in the glass having 2 surfaces facing each other, the OD in the case where the colored layers are provided on both surfaces is about 2 times that in the case where the same colored layer is provided only on one surface.

In the glass of the present embodiment, the OD decreases with an increase in wavelength in a wavelength range from the visible light range to the near infrared range. Therefore, in a portion having the colored layer, for example, the OD at the wavelength of 780nm becomes larger than the OD at the wavelength of 1100 nm.

Therefore, when there is a wavelength range to be shielded from light, the OD of the wavelength on the long wavelength side of the wavelength range is designed to be increased. When designing a glass that blocks only visible light, the OD on the long wavelength side (for example, 780nm) of the visible light range may be set to be increased. In the case of designing a glass for shielding light in the visible light range to the near infrared range, the OD of the glass at a wavelength in the near infrared range (for example, 1100nm) may be set to be increased. The OD can be controlled by adjusting the thickness of the colored layer, the degree of coloring, and the like.

(ΔOD)

As described above, in the glass of the present embodiment, when the colored layer and the non-colored portion having a high transmittance in the visible light range are included, the colored layer OD is large, and the non-colored layer OD becomes small. That is, if the colored layer is removed gradually in the thickness direction, the OD changes according to the removal amount.

The glass having a colored layer according to the present embodiment has OD1 for OD at a given wavelength and T1 for thickness. The OD at the same wavelength when a given amount of the colored layer was removed in the thickness direction by polishing or the like was set to OD2, and the thickness was set to T2. At this time, the change amount Δ OD of OD per unit thickness is calculated by the following equation.

ΔOD＝(OD1-OD2)/(T1-T2)

When measuring Δ OD in OD having a wavelength of 1100nm or more, it is preferable to remove 5 to 20 μm of the colored layer in the thickness direction. When measuring Δ OD in OD having a wavelength of less than 1100nm, it is preferable to remove 3 to 10 μm of the colored layer in the thickness direction. Then, OD measurement and removal of the colored layer were repeated, and Δ OD corresponding to the removal amount of the colored layer was calculated. For example, when the removal amount of the colored layer is 20 μm in total by repeating the removal of the colored layer, the value of (T1-T2) in the above formula is 20.

When the colored layer is removed repeatedly and the colored layer cannot be visually confirmed as a result, the removal is repeated 2 to 3 times for the portion where the colored layer is present so that the portion is finally removed by about 50 μm, and the OD and the thickness of the glass are measured for each removal, and the Δ OD is calculated.

Alternatively, when the OD becomes less than 0.15 as a result of repeating the removal of the colored layer, the portion where the colored layer is present is removed a plurality of times in the thickness direction, and each time 10 μm or more in the thickness direction, the OD and the thickness of the glass are measured, and Δ OD is calculated.

The glass of the present embodiment can be evaluated as having a colored layer remaining when the Δ OD at the wavelengths of 1100nm and 780nm is preferably 0.04 or more, 0.05 or more, 0.07 or more, 0.09 or more, 0.12 or more, 0.15 or more, 0.18 or more, 0.20 or more, 0.25 or more, 0.30 or more, 0.34 or more, or 0.35 or more. In addition, when the Δ OD at the wavelengths of 1100nm and 780nm is preferably 0.025 or less, 0.023 or less, 0.020 or less, 0.017 or less, 0.015 or less, or 0.010 or less, it can be evaluated that the colored layer has been removed.

In the glass of the present embodiment, the boundary between the colored layer and the non-colored portion is clear. Here, the boundary between the colored layer and the non-colored portion is a region from when the degree of coloring of the colored layer becomes weak to when the coloring is sufficiently reduced. The degree of coloration can be assessed by the OD at a given wavelength. Therefore, the change in the degree of coloring in the vicinity of the boundary can be confirmed by the Δ OD. That is, if a region in which the OD significantly changes according to the removal amount of the colored layer can be confirmed by the Δ OD, the region can be used as a boundary between the colored layer and the non-colored portion.

The glass of the present embodiment may have a boundary between the colored layer and the non-colored portion in the thickness direction within a range of several tens μm. Therefore, when the cross section of the glass of the present embodiment is observed with an optical microscope or the like, the boundary between the colored layer and the non-colored portion can be relatively clearly observed.

Therefore, in the glass of the present embodiment, for example, a region having a Δ OD of 0.04 or more can be regarded as a boundary between the colored layer and the non-colored portion. Further, a region having a Δ OD of 0.04 or more, 0.05 or more, 0.07 or more, 0.09 or more, 0.12 or more, 0.15 or more, 0.18 or more, 0.20 or more, 0.25 or more, 0.30 or more, 0.34 or more, or 0.35 or more may be used as a boundary between the colored layer and the non-colored portion. In the glass of the present embodiment, the thickness of this region is preferably 40 μm or less, and more preferably 30 μm or less, 20 μm or less, 10 μm or less, and 5 μm or less in this order.

(refractive index)

In the glass of the present embodiment, the refractive index nd is preferably 1.70 or more, and more preferably 1.73 or more, 1.75 or more, 1.76 or more, 1.77 or more, 1.78 or more, 1.79 or more, and 1.80 or more in this order. The upper limit of the refractive index nd is not particularly limited, but is usually 2.5, preferably 2.3.

Fig. 4 is a view of a glass having 2 opposed surfaces, in which a plurality of colored layers are provided at predetermined intervals at the opposed portions of the two surfaces, respectively, and the portions where the colored layers are not formed function as slits. In this case, if the refractive index of the glass is low, in the case where the incident angle of the light ray incident to the slit portion is large (the light ray is incident at a small angle), the light ray transmits through the adjacent slits as in the path C, and there is a fear that the same effect as that of the element shown in fig. 3-2 cannot be obtained. If the refractive index of the glass is high as in the above range, the light is absorbed by the colored layer formed on the back surface of the glass as in the path B, and the light does not transmit through the adjacent slits, so that the interval between the slits can be narrowed.

(average linear expansion coefficient)

The average linear expansion coefficient of the glass of the present embodiment is preferably 50 × 10^-7K^-1Above, further 60 × 10^-7K^-170 × 10 or more^-7K^-175 × 10 of above^-7K^-180 × 10 or more^-7K^-1Above, 85 × 10^-7K^-1Above, 90 × 10^-7K^-1The above sequence is more preferred. The upper limit of the average linear expansion coefficient is not particularly limited, but is usually 200X 10^-7K^-1Preferably 150X 10^-7K^-1. By setting the average linear expansion coefficient to the above range, the strength of the glass can be improved when chemical strengthening is performed.

The average linear expansion coefficient was measured according to JOGIS08-2003, "method for measuring thermal expansion of optical glass", which is the standard of Japan optical glass Industrial Association. The diameter of the round bar-shaped sample was 5 mm.

(acid-resistant weight reduction ratio Da)

The glass of the present embodiment is preferably rated at an acid-resistant weight reduction rate Da of 1 to 2, and more preferably rated at 1.

The acid-resistant weight reduction rate Da was measured according to the Japanese optical glass industry Association Standard JOGIS 06-2009. Specifically, a powder glass (particle size: 425 to 600 μm) having a weight equivalent to a specific gravity was placed in a platinum cage, immersed in a quartz glass round-bottomed flask containing a 0.01mol/L nitric acid aqueous solution, treated in a boiling water bath for 60 minutes, and the weight reduction (%) before and after the treatment was measured. The grades based on the acid resistance weight reduction rate Da are shown in table a.

[ Table A ]

Grade	Weight loss (%)
		1	Less than 0.20
2	0.20 or more and less than 0.35
		3	0.35 or more and less than 0.65
4	0.65 or more and less than 1.20
		5	1.20 or more and less than 2.20
6	2.20 or more

(glass composition)

The following non-limiting examples are given for the composition of the glass of the present embodiment.

The glass of the present embodiment is preferably phosphate glass. The phosphate glass mainly contains P as a network-forming component of the glass⁵⁺The glass of (2). As a network-forming component of glass, P is known⁵⁺、B³⁺、Si⁴⁺、Al³⁺And the like. Here, the fact that the glass mainly contains phosphate as a network-forming component means P⁵⁺Content ratio of B³⁺、Si⁴⁺、Al³⁺The content of any one of them means more. By using phosphate glass, the degree of coloring in the colored layer can be increased.

In the glass of the present embodiment, P⁵⁺The lower limit of the content of (b) is preferably 10%, and more preferably 13%, 15%, 17%, and 20% in this order. In addition, P⁵⁺The upper limit of the content of (b) is preferably 50%, and more preferably 45%, 40%, 38%, 35%, 33%, and 30% in this order.

P⁵⁺Is a network forming component of the glass. On the other hand, if P is contained excessively⁵⁺The meltability is deteriorated. Thus, P⁵⁺The content of (b) is preferably in the above range.

In the glass of the present embodiment, B ³⁺The upper limit of the content of (b) is preferably 30%, and more preferably 25%, 20%, 15%, 13%, 10% in this order. In addition, B³⁺The lower limit of the content of (b) is preferably 0.1%, and more preferably 0.5%, 1%, 3%, and 5% in this order. B is³⁺The content of (B) may be 0%.

B³⁺Is a network forming component of glass and has a function of improving the meltability of glass. On the other hand, if B³⁺When the content of (b) is too large, the chemical durability tends to be lowered. Thus, B³⁺The content of (b) is preferably in the above range.

In the glass of the present embodiment, B³⁺Relative to P⁵⁺Content of cation ratio [ B ]³⁺/P⁵⁺]The upper limit of (b) is preferably 0.70, and more preferably 0.60, 0.55, and 0.50. Cation ratio [ B³⁺/P⁵⁺]Or may be 0.

In the glass of the present embodiment, Si⁴⁺The upper limit of the content of (b) is preferably 10%, and more preferably 7%, 5%, 3%, 2%, and 1% in this order. In addition, Si⁴⁺The lower limit of the content of (b) is preferably 0.1%, and more preferably 0.2%, 0.3%, 0.4%, and 0.5% in this order. Si⁴⁺The content of (B) may be 0%.

Si⁴⁺Is a network forming component of the glass, and has the function of improving the thermal stability, chemical durability and weather resistance of the glass. On the other hand, if Si ⁴⁺When the content of (A) is too large, the meltability of the glass tends to be lowered and the glass raw material tends not to be completely melted. Thus, Si⁴⁺The content of (b) is preferably in the above range.

In the glass of the present embodiment, Al³⁺The upper limit of the content of (b) is preferably 10%, and more preferably 7%, 5%, 3%, and 1% in this order. In addition, Al³⁺The content of (B) may be 0%.

Al³⁺Has the function of improving the chemical durability and the weather resistance of the glass. On the other hand, if Al³⁺When the content (c) is too large, the thermal stability of the glass is lowered, the glass transition temperature Tg is increased, and the meltability is liable to be lowered. Thus, Al³⁺The content of (b) is preferably in the above range.

In the glass of the present embodiment, P⁵⁺、B³⁺、Si⁴⁺And Al³⁺Total content of [ P ]⁵⁺+B³⁺+Si⁴⁺+Al³⁺]The lower limit of (b) is preferably 10%, and more preferably 15%, 18%, 20%, 23%, and 25% in this order. In addition, the total content [ P ]⁵⁺+B³⁺+Si⁴⁺+Al³⁺]The upper limit of (b) is preferably 60%, and further 50%, 45%, 40%, 37%, 35% in this orderIs preferred.

The glass of the present embodiment preferably contains a transition metal as a glass component, more preferably at least 1 glass component selected from Ti ions, Nb ions, Bi ions, and W ions, and further preferably contains Bi ions.

In the glass of the present embodiment, the lower limit of the content of Ti ions is preferably 1%, and more preferably 2% and 3% in this order. The upper limit of the content of Ti ions is preferably 45%, and more preferably 40%, 35%, 30%, 25%, 20%, 15%, and 12%. Here, the Ti ions contain Ti ⁴⁺、Ti³And other Ti ions having different valences.

Like Nb ions, W ions, and Bi ions, Ti ions significantly contribute to increase in refractive index, and also have a function of enhancing coloring of glass. On the other hand, if the content of Ti ions is too large, the meltability of the glass is lowered and the glass raw material tends to be incompletely melted. Therefore, the content of Ti ions is preferably in the above range.

In the glass of the present embodiment, the lower limit of the content of Nb ions is preferably 1%, and more preferably 5%, 10%, and 15% in this order. The upper limit of the content of Nb ions is preferably 45%, and more preferably 40%, 35%, 30%, 25%, 23%, and 20% in this order. The Nb ion contains Nb⁵⁺And all Nb ions having different valences.

Nb ions contribute to increasing the refractive index and are a component for enhancing the coloring of the glass. In addition, the glass has a function of improving thermal stability and chemical durability of the glass. On the other hand, if the content of Nb ions is too large, the thermal stability of the glass tends to be lowered. Therefore, the content of Nb ions is preferably in the above range.

In the glass of the present embodiment, the upper limit of the content of W ions is preferably 30%, and more preferably 25%, 20%, 15%, and 13% in this order. The lower limit of the content of W ion is preferably 0.5%, and more preferably 1%, 2%, and 3%. W ion contains W ⁶⁺And all other W ions of different valences.

The W ions contribute to increase in refractive index and also have a function of enhancing coloring of the glass. Therefore, the content of W ions is preferably in the above range.

In the glass of the present embodiment, the upper limit of the content of Bi ions is preferably 40%, and more preferably 35%, 30%, 28%, and 25% in this order. The lower limit of the content of Bi ions is preferably 0.5%, and more preferably 1%, 2%, and 2.5% in this order. The Bi ions contain Bi³⁺And all Bi ions having different valences.

The Bi ions contribute to an increase in refractive index and have a function of enhancing coloring of the glass. Therefore, the content of Bi ions is preferably in the above range.

In the glass of the present embodiment, the lower limit of the total content [ Ti + Nb + W ] of Ti ions, Nb ions, and W ions is preferably 1%, and more preferably 5%, 10%, 15%, 20%, and 23% in this order. The upper limit of the total content [ Ti + Nb + W ] is preferably 60%, and more preferably 55%, 50%, 45%, 40%, 38%, and 35% in this order.

In the glass of the present embodiment, the upper limit of the total content [ Ti + Nb + W + Bi ] of Ti ions, Nb ions, W ions, and Bi ions is preferably 80%, and more preferably 75%, 70%, 68%, and 65% in this order. The lower limit of the total content [ Ti + Nb + W + Bi ] is preferably 1%, and more preferably 5%, 10%, 15%, 20%, 23%, 25% in this order.

In the glass of the present embodiment, the total content of Ti ions, Nb ions, W ions and Bi ions is calculated with respect to P⁵⁺、B³⁺And Si⁴⁺The cation ratio of the total content of [ (Ti + Nb + W + Bi)/(P ]⁵⁺+B³⁺+Si⁴⁺)]The lower limit of (b) is preferably 0.1, and more preferably 0.3, 0.5, 0.6, and 0.7 in this order. In addition, the cation ratio [ (Ti + Nb + W + Bi)/(P)⁵⁺+B³⁺+Si⁴⁺)]The upper limit of (b) is preferably 4.0, and more preferably 3.5, 3.0, 2.7 and 2.5.

In the glass of the present embodiment, Ta⁵⁺The upper limit of the content of (b) is preferably 5%, and more preferably 3%, 2%, and 1% in this order. Ta⁵⁺May also be contained in0％。

Ta⁵⁺Has the function of improving the thermal stability of the glass. On the other hand, if Ta⁵⁺When the content of (b) is too large, the refractive index of the glass tends to be low, and the meltability tends to be low. Thus, Ta⁵⁺The content of (b) is preferably in the above range.

In the glass of the present embodiment, Li⁺The upper limit of the content of (b) is preferably 35%, and more preferably 30%, 27%, 25%, 23%, 20% in this order. In addition, Li⁺The lower limit of the content of (b) is 1%, and more preferably 2%, 3%, 5%, and 8% in this order. Li⁺The content of (B) may be 0%.

In the glass of the present embodiment, Na⁺The upper limit of the content of (b) is preferably 40%, and more preferably 35%, 30%, 25%, 20%, 18% in this order. In addition, Na ⁺The lower limit of the content of (b) is 0.5%, and more preferably 1%, 1.5%, 3%, and 5% in this order. Na (Na)⁺The content of (B) may be 0%.

Glass by containing Li⁺Or Na⁺It becomes easy to apply chemical strengthening to the glass. On the other hand, if Li⁺Or Na⁺When the content of (b) is too large, the thermal stability of the glass may be lowered. Thus, Li⁺And Na⁺The respective contents of (a) and (b) are preferably within the above ranges.

In the glass of the present embodiment, Li⁺And Na⁺Total content of [ Li ]⁺+Na⁺]The upper limit of (b) is preferably 45%, and more preferably 43%, 40%, and 38% in this order. In addition, total content [ Li⁺+Na⁺]The lower limit of (b) is preferably 1%, and more preferably 5%, 10%, 15%, 20% in this order.

In the glass of the present embodiment, K⁺The upper limit of the content of (b) is preferably 20%, and more preferably 15%, 13%, 10%, 8%, 5%, 3% in this order. In addition, K⁺The lower limit of the content of (b) is 0.1%, and more preferably 0.5%, 1.0%, and 1.2% in this order. K⁺The content of (B) may be 0%.

K⁺Has the function of improving the heat of glassThe function of stability. On the other hand, if K⁺When the content of (b) is too large, thermal stability tends to be lowered. Thus, K⁺The content of (b) is preferably in the above range.

In the glass of the present embodiment, Rb⁺The upper limit of the content of (b) is preferably 5%, and more preferably 3%, 1%, and 0.5% in this order. Rb⁺The content of (B) may be 0%.

In the glass of the present embodiment, Cs⁺The upper limit of the content of (b) is preferably 5%, and more preferably 3%, 1%, and 0.5% in this order. Cs⁺The content of (B) may be 0%.

Rb⁺And Cs⁺Has a function of improving the meltability of glass. On the other hand, if the content is too large, the refractive index nd may decrease, and the volatilization of the glass component may increase during melting. Thus, Rb⁺And Cs⁺The respective contents of (a) and (b) are preferably within the above ranges.

In the glass of the present embodiment, Mg²⁺The upper limit of the content of (b) is preferably 15%, and more preferably 10%, 5%, 3%, and 1% in this order. Mg (magnesium)²⁺The content of (B) may be 0%.

In the glass of the present embodiment, Ca²⁺The upper limit of the content of (b) is preferably 15%, and more preferably 10%, 5%, 3%, and 1% in this order. Ca²⁺The content of (B) may be 0%.

In the glass of this embodiment, Sr²⁺The upper limit of the content of (b) is preferably 15%, and more preferably 10%, 5%, 3%, and 1% in this order. Sr²⁺The content of (B) may be 0%.

In the glass of the present embodiment, Ba ²⁺The upper limit of the content of (b) is preferably 25%, and more preferably 20%, 18%, 15%, 10%, and 5% in this order. Ba²⁺The content of (B) may be 0%.

Mg²⁺、Ca²⁺、Sr²⁺And Ba²⁺All have the function of improving the thermal stability and the melting property of the glass. On the other hand, if the content is too large, the high refractive index property is impaired, and further, the thermal stability of the glass is impairedThe sexual activity may be reduced. Therefore, the content of each of these glass components is preferably within the above range.

In the glass of the present embodiment, Mg²⁺、Ca²⁺、Sr²⁺And Ba²⁺Total content of [ Mg²⁺、Ca²⁺、Sr²⁺And Ba²⁺]The upper limit of (b) is preferably 30%, and more preferably 25%, 20%, 18%, 15%, 10%, and 5% in this order.

In the glass of the present embodiment, Zn²⁺The upper limit of the content of (b) is preferably 15%, and more preferably 10%, 8%, 5%, 3%, and 1% in this order. In addition, Zn²⁺The lower limit of the content of (b) is preferably 0.1%, and more preferably 0.3% and 0.5%. Zn²⁺The content of (B) may be 0%.

Zn²⁺Has the function of improving the thermal stability of the glass. On the other hand, if Zn²⁺If the content of (b) is too large, the meltability may deteriorate. Thus, Zn²⁺The content of (b) is preferably in the above range.

In the glass of the present embodiment, Zr⁴⁺The upper limit of the content of (b) is preferably 5%, and more preferably 3%, 2%, and 1% in this order. Zr ⁴⁺The content of (B) may be 0%.

Zr⁴⁺Has the function of improving the thermal stability of the glass. On the other hand, if Zr⁴⁺When the content of (b) is too large, the thermal stability and melting property of the glass may be deteriorated. Thus, Zr⁴⁺The content of (b) is preferably in the above range.

In the glass of the present embodiment, Ga³⁺The upper limit of the content of (b) is preferably 3%, and more preferably 2% and 1%. In addition, Ga³⁺The lower limit of the content of (b) is preferably 0%. Ga³⁺The content of (B) may be 0%.

In the glass of the present embodiment, In³⁺The upper limit of the content of (b) is preferably 3%, and more preferably 2% and 1%. In addition, In³⁺The lower limit of the content of (b) is preferably 0%. In³⁺The content of (B) may be 0%.

In the glass of the present embodiment, Sc³⁺The upper limit of the content of (b) is preferably 3%, and more preferably 2% and 1%. In addition, Sc³⁺The lower limit of the content of (b) is preferably 0%. Sc (Sc)³⁺The content of (B) may be 0%.

In the glass of the present embodiment, Hf⁴⁺The upper limit of the content of (b) is preferably 3%, and more preferably 2% and 1%. In addition, Hf⁴⁺The lower limit of the content of (b) is preferably 0%. Hf (hafnium)⁴⁺The content of (B) may be 0%.

In the glass of the present embodiment, Lu³⁺The upper limit of the content of (b) is preferably 3%, and more preferably 2% and 1%. In addition, Lu ³⁺The lower limit of the content of (b) is preferably 0%. Lu (Lu)³⁺The content of (B) may be 0%.

In the glass of the present embodiment, Ge⁴⁺The upper limit of the content of (b) is preferably 3%, and more preferably 2% and 1%. In addition, Ge⁴⁺The lower limit of the content of (b) is preferably 0%. Ge (germanium) oxide⁴⁺The content of (B) may be 0%.

In the glass of the present embodiment, La³⁺The upper limit of the content of (b) is preferably 5%, and more preferably 4% and 3%. In addition, La³⁺The lower limit of the content of (b) is preferably 0%. La³⁺The content of (B) may be 0%.

In the glass of the present embodiment, Gd³⁺The upper limit of the content of (b) is preferably 5%, and more preferably 4% and 3%. In addition, Gd³⁺The lower limit of the content of (b) is preferably 0%. Gd (Gd)³⁺The content of (B) may be 0%.

In the glass of the present embodiment, Y³⁺The upper limit of the content of (b) is preferably 5%, and more preferably 4% and 3%. In addition, Y³⁺The lower limit of the content of (b) is preferably 0%. Y is³⁺The content of (B) may be 0%.

In the glass of the present embodiment, Yb³⁺The upper limit of the content of (b) is preferably 3%, and more preferably 2% and 1%. In addition, Yb³⁺The lower limit of the content of (b) is preferably 0%. Yb of³⁺The content of (B) may be 0%.

The present embodimentThe cationic component of the glass (A) is mainly the above-mentioned component, i.e., preferably P ⁵⁺、B³⁺、Si⁴⁺、Al³⁺Ti ion, Nb ion, W ion, Bi ion, Ta⁵⁺、Li⁺、Na⁺、K⁺、Rb⁺、Cs⁺、Mg²⁺、Ca²⁺、Sr²⁺、Ba²⁺、Zn²⁺、Zr⁴⁺、Ga^{3 +}、In³⁺、Sc³⁺、Hf⁴⁺、Lu³⁺、Ge⁴⁺、La³⁺、Gd³⁺、Y³⁺And Yb³⁺The total content of the above components is preferably more than 95%, more preferably more than 98%, still more preferably more than 99%, and still more preferably more than 99.5%.

The glass of the present embodiment may contain F as an anionic component^-And O^2-Other components. As F^-And O^2-Other anionic components, Cl may be exemplified^-、Br^-、I^-. However, Cl^-、Br^-、I^-All of which are easily volatilized in the melting of glass. Volatilization of these components causes problems such as fluctuation in glass characteristics, deterioration in glass homogeneity, and significant consumption of melting equipment. Thus, Cl^-Preferably less than 5 anions%, more preferably less than 3 anions%, further preferably less than 1 anion%, particularly preferably less than 0.5 anions%, and even more preferably less than 0.25% anions. In addition, Be^-And I^-Preferably less than 5 anions%, more preferably less than 3 anions%, further preferably less than 1 anion%, particularly preferably less than 0.5 anions%, further preferably less than 0.25 anions%, still further preferably 0 anions%.

The "anion%" refers to a molar percentage of the total content of all the anion components taken as 100%.

The glass of the present embodiment is preferably composed substantially of the above components, but may contain other components within a range not impairing the action and effect of the present invention.

For example, in the glass of the present embodiment, the glass component may contain an appropriate amount of copper (Cu) in order to further impart the near-infrared light absorption characteristics to the glass. Further, V, Cr, Mn, Fe, Co, Ni, Pr, Nd, Pm, Sm, Eu, Tb, Dy, Ho, Er, Tm, Ce and the like may be contained. These components may enhance the coloring of the glass and may 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, Se are toxic. Therefore, the glass of the present embodiment preferably does not contain these elements as glass components.

U, Th and Ra are radioactive elements. Therefore, the glass of the present embodiment preferably does not contain these elements as glass components.

Sb³⁺、Sn⁴⁺And Ce⁴⁺The glass component can be added arbitrarily, functioning as a fining agent. Wherein Sb³⁺Is a clarifying agent with remarkable clarifying effect.

Sb³⁺Converted into Sb₂O₃And expressed in mass% of the addition ratio. Here, the term "addition ratio" means that Sb is added ³⁺、Sn⁴⁺And Ce⁴⁺Content ratio of other cation component to Sb₂O₃Similarly, in terms of oxide, and in the presence of Sb³⁺、Sn⁴⁺And Ce⁴⁺Sb is represented by mass% when the total content of all the other cationic components is 100 mass%₂O₃The content of (a). Sb₂O₃The content of (b) is preferably less than 2% by mass, more preferably less than 1% by mass, still more preferably less than 0.5% by mass, yet more preferably less than 0.2% by mass, still more preferably less than 0.1% by mass, and yet more preferably less than 0.05% by mass. By reacting Sb₂O₃The content of (b) is in the above range, the fining of the glass can be improved.

Sn⁴⁺And Ce⁴⁺The contents of (a) are also expressed in terms of oxides and in addition ratios. Namely, mixing Sb³⁺、Sn⁴⁺And Ce⁴⁺The content ratio of the other cation component is converted into oxide, and Sb is added³⁺、Sn⁴⁺And Ce⁴⁺SnO is expressed in terms of mass% when the total content of all other cationic components is 100 mass%₂Content of (C), CeO₂The content of (a). SnO₂And CeO₂The content of (b) is preferably less than 2% by mass, more preferably less than 1% by mass, still more preferably less than 0.5% by mass, and still more preferably less than 0.1% by mass, respectively. SnO₂And CeO₂The content of (b) may be 0% by mass. By separately reacting SnO₂And CeO₂When the content of (b) is within the above range, the glass can be improved in the clarity.

(production of glass)

The glass of the present embodiment can be obtained by preparing glass without coloring and forming a colored layer therein. The glass without coloring may be produced by a known glass production method. For example, a plurality of compounds are blended and mixed well to prepare a batch material, the batch material is charged into a melting vessel to be melted, clarified and homogenized, and then molten glass is formed and slowly cooled to obtain glass. Alternatively, the glass may be obtained by charging a batch of raw materials into a melting vessel to perform rough melting (rough melting), rapidly cooling and crushing a melt obtained by the rough melting to prepare glass chips, charging the glass chips into the melting vessel to heat and remelt (remelt) the glass chips to prepare molten glass, further clarifying and homogenizing the molten glass, and then forming and slowly cooling the molten glass. The molten glass may be formed and slowly cooled by a known method.

The glass production process of the present embodiment may include a step of increasing the amount of water in the molten glass. Examples of the step of increasing the amount of water in the molten glass include a step of adding water vapor to a melting atmosphere and a step of bubbling a gas containing water vapor into the molten material. Among them, the step of adding steam to the molten atmosphere is preferable. The beta OH value of the glass can be increased by including a step of increasing the amount of water in the molten glass. By increasing the value of β OH, a glass having higher transparency can be obtained.

(formation of colored layer)

The colored layer can be formed by attaching a metal film to the glass surface and performing heat treatment in a reducing atmosphere.

The metal constituting the metal film is preferably a metal having a function of absorbing hydrogen ions in an atmosphere and reducing glass components contained in the glass by the transfer of hydrogen ions and electrons. Among the glass components, metals having a function of reducing the transition metal are more preferable. Specific examples thereof include Ni, Au, Ag, Pt, Pd and Pt-Pd alloys.

The method for sticking the metal film to the glass surface is not particularly limited as long as the metal film can be stuck so as to be in close contact with the glass surface, and examples thereof include: vapor deposition, sputtering, plating, or coating of a metal paste or plating solution.

The reducing atmosphere may contain a gas having a reducing power. Examples of the gas having a reducing power include hydrogen. Therefore, a hydrogen-containing gas is preferably used as the reducing atmosphere, and a synthesis gas containing hydrogen may be used. The synthesis gas is a mixed gas containing hydrogen and nitrogen, and usually contains about 3 to 5 vol% of hydrogen.

In the heat treatment, the glass is heated at a temperature of 200 ℃ or higher (Tg-200) lower than the glass transition temperature Tg and at a temperature of not higher than the softening point temperature. The heat treatment time can be appropriately adjusted according to the degree of coloring of the object, the range of the colored layer, the thickness of the colored layer, and the like.

After the heat treatment, the metal film was peeled off from the glass surface. The method of peeling is not particularly limited, and examples thereof include a method of polishing, dissolving and removing.

By heat treatment in a reducing atmosphere, a colored layer is formed from the surface of the glass in contact with the metal film to the inside.

The mechanism of forming the colored layer by the above method is not particularly limited, but is considered to be the following mechanism.

The coloring of the colored layer formed in the present embodiment is considered to be a reduction color due to the glass component, and is especially considered to be a reduction color due to the transition metal. Generally, even when the glass molded body is subjected to heat treatment in an atmosphere containing hydrogen gas at a low concentration of about 3 to 5 vol%, the glass hardly exhibits a reduced color. However, since the metal film stores hydrogen ions in the atmosphere, hydrogen ions are supplied to a portion of the glass that is in contact with the metal film in a larger amount than to a portion that is not in contact with the metal film, and as a result, the reduction reaction proceeds rapidly. Therefore, the portion of the glass in contact with the metal film is deeply colored. The hydrogen ion occlusion amount of the metal film is large, and the hydrogen concentration in the atmosphere is lowered even by occlusion of the metal film. For this reason, the reduction reaction is difficult in the portion not in contact with the metal film.

Here, the reduction reaction of the glass component, which is a main cause of coloring, proceeds in all directions from the portion in contact with the metal film. That is, the colored layer is formed in the thickness direction from the glass surface in contact with the metal film if viewed from the cross section of the glass, and is formed radially from the portion in contact with the metal film if viewed from the surface of the glass.

By the above method, a colored layer with deeper coloring can be formed. Therefore, even if the thickness of the colored layer is small, the transmittance can be sufficiently reduced. When the thickness of the colored layer is small, the range of the colored layer formed radially from the portion in contact with the metal film is also small as viewed from the surface of the glass. That is, according to the present embodiment, by adjusting the conditions for forming the colored layer, the colored layer having substantially the same shape as the metal film can be formed when viewed from the glass surface.

(production of optical element, etc.)

The optical element formed of the glass of the present embodiment is obtained by preparing an optical element having no coloring layer and forming a colored layer therein. The optical element having no coloring may be manufactured by a known manufacturing method. For example, a glass material is produced by pouring molten glass into a mold and forming the molten glass into a sheet shape. The obtained glass material is appropriately cut, ground and polished to prepare a cut piece having a size and a shape suitable for press molding. The cut pieces were heated and softened, and press-formed by a known method (reheating and pressing) to prepare an optical element blank having a shape similar to that of an optical element. The optical element blank is annealed, and polished by a known method to produce an optical element.

In the fabricated optical element, the colored layer was formed by the above-described method. Further, the colored layer may be formed at a stage in the process of manufacturing the optical element.

An antireflection film, a total reflection film, or the like may be applied to the optically functional surface of the produced optical element depending on the purpose of use.

According to one embodiment of the present invention, an optical element formed of the above glass can be provided. Examples of the type of the optical element include a lens such as a spherical lens or an aspherical lens, and a prism. As the shape of the lens, various shapes such as a biconvex lens, a plano-convex lens, a biconcave lens, a plano-concave lens, a meniscus lens, a convex-concave lens, and the like can be exemplified. The optical element can be produced by a method including a step of processing a glass molded body made of the above glass. As the machining, cutting, rough grinding, fine grinding, polishing, and the like can be exemplified.

As an example of the optical element, an optical element for shielding light obliquely incident on a light receiving surface of an image sensor such as a CCD or a C-MOS sensor is shown. Conventionally, in order to block oblique incident light on a light receiving surface of an image sensor, the following method is adopted: the black ink is applied to a portion of the surface of the cover glass of the image sensor, which is to be shielded from obliquely incident light, to provide light shielding properties. In this method, light is reflected on the surface of the black ink at the boundary between the portion where the black ink is applied and the portion where the black ink is not applied, and the light is converted into stray light, which causes a problem in that the image quality of the image sensor is degraded. In addition, the ink outgases when the temperature rises, which causes the surface of the cover glass to be blurred. On the other hand, by using the glass of the present embodiment and providing a colored layer as a cover glass at a portion intended to shield obliquely incident light, the problems of stray light, fogging due to outgassing, and the like can be solved.

In addition, according to one embodiment of the present invention, the colored layer can be used as an ornament, an exterior of a small electronic device, or the like, by utilizing the decorative property of the colored layer.

Examples

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

Glass samples having glass compositions shown in table 1 were produced by the following procedure, and various evaluations were performed.

[ Table 1]

[ production of glass ]

Oxides, hydroxides, metaphosphates, carbonates, and nitrates corresponding to the constituent components of the glass were prepared as raw materials, and the raw materials were weighed and blended so that the compositions of the obtained glasses were each composition shown in table 1, and the raw materials were thoroughly mixed. The obtained blended raw materials (batch raw materials) are put into a platinum crucible and heated at 1100-1450 ℃ for 2-3 hours to prepare the molten glass. The molten glass is stirred to homogenize the molten glass, and after the molten glass is clarified, the molten glass is cast into a mold preheated to an appropriate temperature. The cast glass was subjected to a heat treatment at around the glass transition temperature Tg for about 1 hour, and naturally cooled to room temperature in a furnace. The glass sample was processed into a size of 40mm in length, 10mm in width and 1.0mm in thickness, and 2 faces of 40mm × 10mm were precision-polished (optical polishing) to obtain a glass sample.

[ confirmation of glass composition ]

The contents of the respective glass components of the obtained glass samples were measured by inductively coupled plasma atomic emission spectrometry (ICP-AES) to confirm that the glass samples had the respective compositions shown in table 1.

[ measurement of optical Properties ]

The refractive index nd, specific gravity and glass transition temperature Tg of the obtained glass samples were measured, and the results are shown in Table 1.

(i) Refractive index nd

The refractive index nd was measured by a refractive index measuring method according to JIS B7071-1.

(ii) Specific gravity of

The specific gravity was measured by the archimedes method.

(iii) Glass transition temperature Tg

The glass transition temperature was measured at a temperature rising rate of 4 ℃ per minute using a thermomechanical analyzer (TMA4000S) manufactured by MAC Science.

[ average Linear expansion coefficient ]

The average linear expansion coefficient was measured in accordance with "method for measuring thermal expansion of optical glass" standard of Japan optical glass Industrial Association, JOGIS08-2003, and the diameter of a round bar-shaped sample was set to 5mm, and the results are shown in Table 1.

[ acid-resistant weight reduction ratio Da ]

The obtained glass sample was converted into powder glass (particle size: 425 to 600 μm) having a weight equivalent to a specific gravity according to the specification of JOGIS06-2009, which was placed in a platinum cage, immersed in a round-bottomed flask made of quartz glass to which a 0.01mol/L nitric acid aqueous solution was added, treated in a boiling water bath for 60 minutes, and the weight reduction (%) before and after the treatment was measured. The weight reduction (%) was evaluated in grades, and the results are shown in table 1.

Example 1: formation of colored layers in samples having different glass compositions

(example 1-1)

Among the obtained glass samples, the Pt-Pd film was formed in a pattern by sputtering on one surface of the optically polished surface of the glass sample having the glass composition of No.1 (current at the time of sputtering 15mA, film formation time 900 seconds).

The glass sample on which the Pt — Pd film was formed was subjected to heat treatment at 400 ℃ for 5 hours while supplying a forming gas (hydrogen 3 vol%, nitrogen 97 vol%) as a reducing atmosphere at a flow rate of 0.2L/min.

The Pt-Pd film was peeled off by polishing, and a glass sample having a colored layer was obtained. The resulting glass sample is shown in FIG. 5-1.

[ measurement of transmittance ]

The external transmittance at a wavelength of 300 to 2500nm was measured. The external transmittance is defined as: when light is incident in the thickness direction of the glass sample, the percentage of the transmitted light intensity with respect to the incident light intensity [ transmitted light intensity/incident light intensity × 100 ]. The external transmittance also includes reflection loss of light on the sample surface, and the result is shown in fig. 6-1. In the figure, the broken line indicates the transmittance of a portion having a colored layer, and the solid line indicates the transmittance of the same portion before the colored layer is formed.

[ measurement of OD ]

For the portion having the colored layer, the incident light intensity I at a wavelength of 1100nm was measured ₀And the transmitted light intensity I, and the OD (optical density) is calculated by the following equation. The OD before forming the colored layer was similarly calculated for the same portion. The results are shown in Table 2.

OD＝-log₁₀(I/I₀)

(examples 1 to 2)

A glass sample having a colored layer was obtained in the same manner as in example 1-1, except that the glass sample having the glass composition of No.2 was used. The resulting glass sample is shown in FIG. 5-2.

The transmittance was measured in the same manner as in example 1-1, and the results are shown in FIG. 6-2.

OD was measured in the same manner as in example 1-1, and the results are shown in Table 2.

(examples 1 to 3)

A glass sample having a colored layer was obtained in the same manner as in example 1-1, except that a glass sample having a glass composition of No.3 was used and heat treatment was performed at 430 ℃ for 9 hours.

The transmittance was measured in the same manner as in example 1-1, and the results are shown in FIGS. 6-3.

OD was measured in the same manner as in example 1-1, and the results are shown in Table 2.

[ Table 2]

Glass sample	Before the formation of the colored layer	After the colored layer is formed
			No.1	0.1	4.0
No.2	0.1	0.9
			No.3	0.1	2.1

(examples 1 to 4)

Glass samples having glass compositions shown in table 6 were produced in the same procedure as described above. The composition of the glass component was confirmed in the same manner as described above, and the refractive index nd, specific gravity and glass transition temperature Tg were measured. Glass samples having colored layers were obtained in the same manner as in example 1-1, except that synthesis gas was supplied at the hydrogen concentration (vol%) and the flow rate shown in table 6, and heat treatment was performed at the treatment temperature and the treatment time shown in table 6. OD was measured in the same manner as in example 1-1, and the results are shown in Table 6.

[ Table 6]

Example 2: formation of colored layer based on metal film having different film thickness

(example 2-1)

On one surface of the optically polished surface of the glass sample having the glass composition of No.3, Pt-Pd films having film thicknesses of 28nm, 256nm, 288nm and 420nm were formed by adjusting the film forming conditions.

The glass sample on which the Pt — Pd film was formed was heat-treated at 400 ℃ for 4 hours while supplying a forming gas (hydrogen 3 vol%, nitrogen 97 vol%) as a reducing atmosphere at a flow rate of 0.2L/min.

The Pt-Pd film was removed by polishing, and a glass sample having a colored layer was obtained.

The transmittance was measured for the portion having the colored layer in the same manner as in example 1-1, and the relationship between the film thickness and the transmittance of the Pt-Pd film is shown in FIG. 7-1.

OD was measured for the portions having the colored layers in the same manner as in example 1-1, and the relationship between the film thickness of the Pt-Pd film and OD is shown in FIG. 8.

(example 2-2)

Pt-Pd films having thicknesses of 437nm, 695nm, 778nm, and 892nm were formed on one surface of the optically polished surface of the glass sample having the glass composition of No.3 by adjusting the film forming conditions.

The glass sample on which the Pt — Pd film was formed was heat-treated at 400 ℃ for 9 hours while supplying a forming gas (hydrogen 3 vol%, nitrogen 97 vol%) as a reducing atmosphere at a flow rate of 0.2L/min.

The Pt-Pd film was removed by polishing, and a glass sample having a colored layer was obtained.

The transmittance was measured in the same manner as in example 2-1, and the relationship between the film thickness of Pt-Pd and the transmittance is shown in FIG. 7-2.

OD was measured in the same manner as in example 2-1, and the relationship between the Pt-Pd film thickness and OD is shown in FIG. 8.

As is clear from fig. 7-1, 7-2, and 8, the transmittance and OD of the portion having the colored layer depend on the heat treatment time, not on the film thickness of the metal film.

Example 3: formation of colored layers based on different types of metal films

(example 3-1)

A glass sample having a colored layer was obtained in the same manner as in example 1-1, except that an Au film having a film thickness of 15nm or 300nm was formed on the optically polished surface of the glass sample having a glass composition of No.3 in place of the Pt-Pd film, and the heat treatment was carried out at 450 ℃ for 7 hours.

The OD of the portion having the colored layer was measured in the same manner as in example 1-1.

(example 3-2)

A glass sample having a colored layer was obtained in the same manner as in example 1-1, except that an Ag paste was applied to the optically polished surface of the glass sample having the glass composition of No.3 in place of forming a Pt-Pd film, and heat treatment was performed at 430 ℃ for 10 hours.

OD was measured in the same manner as in example 3-1, and the results are shown in Table 3.

[ Table 3]

(examples 3 to 3)

A glass sample having a colored layer was obtained in the same manner as in example 1-1, except that an Ni film having a film thickness of about 15nm was formed on the optically polished surface of the glass sample having a glass composition of No.3 by using a vacuum evaporator in place of the Pt-Pd film, and heat treatment was performed at 430 ℃ for 7 hours. OD was measured in the same manner as in example 3-1, and the results are shown in Table 9.

(examples 3 to 4)

A glass sample having a colored layer was obtained in the same manner as in example 1-1, except that a commercially available Pd plating solution was applied to the optically polished surface of a glass sample having a thickness of 0.4mm and having a glass composition of No.14, and dried at room temperature to form a Pd plating film, instead of the Pt — Pd film, and heat treatment was performed at 410 ℃ for 15 hours. OD was measured in the same manner as in example 3-1, and the results are shown in Table 9.

[ Table 9]

Example 4: cross-sectional observation of glass having colored layer formed thereon

(example 4-1)

A Pt-Pd film was formed on one side of the optically polished surface of a glass sample having a glass composition of No. 3. In addition, a part of the optical polishing surface of the same sample was polished with a polishing agent of #1000 (#1000), and a Pt — Pd film was also formed on this part.

Synthesis gas (hydrogen 3 vol%, nitrogen 97 vol%) was supplied at a flow rate of 0.2L/min, and heat treatment was performed at 400 ℃ for 5 hours.

The Pt-Pd film was removed by polishing, and a glass sample having a colored layer was obtained.

The thickness of the colored layer was measured, and the results are shown in table 4. The photomicrographs of the cross section of the portion having the colored layer are shown in table 4. In the photomicrographs of table 4, the right side is glass, and the central black part is a colored layer.

(example 4-2)

An Au film was formed on one side of the optically polished surface of the glass sample having the glass composition of No. 3.

A glass sample having a colored layer was obtained in the same manner as in example 4-1, except that the heat treatment was carried out at 450 ℃ for 7 hours.

The thickness of the colored layer and the cross section of the portion having the colored layer are shown in table 4.

OD was measured for the portion having the colored layer in the same manner as in example 1-1, and the results are shown in Table 4.

(examples 4 to 3)

An Au film was formed on one side of the optically polished surface of the glass sample having the glass composition of No. 3. A glass sample having a colored layer was obtained in the same manner as in example 4-2, except that the film formation time of the Au film was longer than that in example 4-2.

The thickness of the colored layer and the cross section of the portion having the colored layer are shown in table 4.

OD was measured in the same manner as in example 4-2, and the results are shown in Table 4.

(examples 4 to 4)

A glass sample having a colored layer was obtained in the same manner as in example 4-2, except that Pt-Pd films were formed on both sides of the optically polished surface of the glass sample having the glass composition of No. 3.

The thickness of the colored layer and the cross section of the portion having the colored layer are shown in table 4.

OD was measured in the same manner as in example 4-2, and the results are shown in Table 4.

The surface polished with the polishing agent of 1000 # (#1000) had a surface roughness larger than that of the optically polished surface. As is clear from table 4, the surface roughness of the glass causes a change in the thickness of the formed colored layer.

Example 5: formation of colored layer having dot pattern

The Pt-Pd film was formed in a dot pattern on the optical polished surface of the glass sample having the glass composition of No.3, as described in detail below.

A metal plate having a high flatness capable of covering a glass surface and having openings in a dot pattern is prepared. The metal plate was brought into close contact with the optically polished surface of the glass sample, and a Pt-Pd film was formed in accordance with the opening of the dot pattern.

The metal plate was peeled off, and the glass sample having the Pt — Pd film formed in the dot pattern was heat-treated in the same manner as in example 1-3, to obtain a glass sample having a colored layer.

The resulting glass sample is shown in FIG. 9.

Example 6: change in transmittance due to removal of colored layer

A glass sample having a colored layer was obtained in the same manner as in examples 1 to 3, except that the glass sample having a glass composition of No.3 was processed to have a thickness of 750. mu.m.

The cross section of the portion having the colored layer was observed with a microscope, and it was confirmed that the thickness of the colored layer was 110 μm. Further, OD was measured for the portion having the colored layer in the same manner as in example 1-1, and the results are shown in Table 5.

The obtained glass sample was polished from the surface having the colored layer until the thickness of the glass sample became 660 μm, and the OD was measured for the same portion, and the results are shown in Table 5.

Likewise, polishing was performed until the thickness of the glass sample became 610 μm, 500 μm, 380 μm, and the OD was measured for the same portion. In addition, the amount of change was calculated from the OD before polishing (no amount of removal by polishing, i.e., no removal by polishing). The OD results are shown in Table 5. In table 5, "polishing removal amount" is the removal amount by polishing, and is represented by the thickness.

[ Table 5]

Thickness (μm)	750	660	610	500	380
						Removal amount by polishing (μm)	0	90	140	250	370
OD(1100nm)	1.52	0.86	0.06	0.08	0.02
						Variation of OD (1100nm)	―	-0.66	-1.45	-1.44	-1.49

According to Table 5, if the removal amount by polishing (removal amount by polishing) of the glass sample exceeds 140 μm, the change amount of OD becomes small. The glass sample, if polished to remove the colored layer, will become only a non-colored portion (a transparent region without coloring). Therefore, it becomes a result that the OD is almost constant even if the thickness is reduced by re-polishing. That is, from the result of the change in OD by polishing, it is estimated that the thickness of the colored layer of the glass sample exceeds 90 μm and is less than 140 μm. This corresponds to the thickness (110 μm) of the colored layer observed by a microscope of a cross section. The increase or decrease in OD in the range of 140 to 370 μm in the removal amount by polishing (removal amount by polishing) is a slight amount, and is considered as a measurement error.

Example 7: change in transmittance due to removal of colored layer (2)

A glass sample having a colored layer was obtained in the same manner as in example 1-1, except that the glass sample having a glass composition of No.3 was processed to have a thickness of 1 mm.

The cross section of the portion having the colored layer was observed with a microscope, and it was confirmed that the thickness of the colored layer was about 55 μm, and a photomicrograph of the cross section of the portion having the colored layer is shown in fig. 10. Further, OD at wavelengths of 1100nm and 780nm were measured for the portion having the colored layer in the same manner as in example 1-1. Further, OD was measured on the portions having the colored layers except for 7 μm, 17 μm, 32 μm, 52 μm, 71 μm, and 83 μm in the thickness direction. The actual measured values of OD, the change amounts of OD (OD1-OD2) compared with before removing the colored layer, and Δ OD are shown in tables 7 and 8. Fig. 11 and 12 show graphs of measured values of OD with the horizontal axis representing the removal amount in the thickness direction. Δ OD is calculated from the following equation.

Δ OD (OD1-OD 2)/(removal [ μm ])

[ Table 7]

[ Table 8]