Glass article

Abstract

To provide a glass article that is excellent in glitter and fire and changes in color tone according to a light source for observation.SOLUTION: A glass article contains, in mol%, La2O3 of more than 0% to 70%, Nb2O5+Ta2O5+Gd2O3+ZrO2+TiO2+Ga2O3+B2O3+Al2O3 of more than 0%, and Ho2O3+Nd2O3 of more than 0% to 20%.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a glass article suitable for use as an ornament such as a ring, a pendant, an earring, or a bracelet. [Background technology]

[0002] Glass that changes color when exposed to different light sources is known. For example, neodymium-containing glass changes color from purple under sunlight to light blue under fluorescent lighting. In addition, techniques have been proposed for customizing the color of glass by adding various coloring elements (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2016-537286 [Patent Document 2] Special Publication No. 2019-513679 Summary of the Invention [Problem to be solved by the invention]

[0004] However, all of the above glasses are made mainly of SiO2 and have a low refractive index, so they do not provide sufficient brilliance when used as ornaments. In addition, the iridescent brilliance known as "fire" tends to be weak.

[0005] In view of the above, an object of the present invention is to provide a glass article that has excellent brilliance and fire and changes color when exposed to different light sources. [Means for solving the problem]

[0006] As a result of intensive research, the present inventors have found that the above-mentioned problems can be solved by a glass article having a composition in which Ho2O3 or Nd2O3 is contained in a base glass containing La2O3 as an essential component.

[0007] That is, the glass article of the present invention is characterized by containing, in mole percent, more than 0 to 70% La2O3, more than 0% Nb2O5+Ta2O5+Gd2O3+ZrO2+TiO2+Ga2O3+B2O3+Al2O3, and more than 0 to 20% Ho2O3+Nd2O3. In this specification, "x+y+···" means the total amount of each component.

[0008] The glass article of the present invention preferably contains, in mole percent, more than 0% of Nb2O5+Ta2O5+Gd2O3+ZrO2+TiO2+Ga2O3.

[0009] The glass article of the present invention preferably contains, in mole percent, more than 0 and 80% of B2O3 + Al2O3.

[0010] A glass article according to another aspect of the present invention is characterized by containing, in mole percent, La2O3 greater than 0 to 70%, Nb2O5+Ta2O5+Gd2O3+ZrO2+TiO2+Ga2O3 greater than 0%, and Ho2O3+Nd2O3 greater than 0 to 20%.

[0011] A glass article according to yet another aspect of the present invention is characterized by containing, in mole percent, La2O3 more than 0 to 70%, B2O3+Al2O3 more than 0 to 80%, and Ho2O3+Nd2O3 more than 0 to 20%.

[0012] A glass article according to yet another aspect of the present invention is characterized by containing, in mole percent, La2O3 more than 0 to 70%, Nb2O5+Ta2O5+Gd2O3+ZrO2+TiO2+Ga2O3 more than 0%, B2O3+Al2O3 more than 80%, and Ho2O3+Nd2O3 more than 0 to 20%.

[0013] The glass article of the present invention may contain 0 to 20% by mole of a coloring component made of an oxide of V, Cr, Mn, Fe, Co, Ni, Cu, Mo, Ru, Ce, Pr or Er, which allows the color tone of the glass article to be varied.

[0014] The glass article of the present invention preferably has a refractive index of 1.7 or more and an Abbe number of 45 or less. By increasing the refractive index of the glass article, the difference in refractive index between the inside and the outside (atmosphere) of the glass article increases, and light is more likely to be reflected inside the glass article. As a result, it becomes easier to obtain sufficient brightness as a glass article. In addition, by decreasing the Abbe number, high dispersion is achieved, making it easier to generate fire.

[0015] The glass article of the present invention preferably exhibits a first color tone when exposed to sunlight and exhibits a second color tone different from the first color tone when exposed to fluorescent light, which makes it easier to exhibit different color tones indoors and outdoors, making it suitable for decorative purposes.

[0016] The glass article of the present invention is preferably subjected to a chamfering process, which makes it easier for light to be reflected inside the glass article, thereby making it possible to enhance the brilliance.

[0017] The glass article of the present invention is preferably for decorative purposes.

[0018] The glass article of the present invention is preferably a simulated gemstone.

[0019] The decorative article of the present invention is characterized by comprising the above-mentioned glass article. Effect of the Invention

[0020] According to the present invention, it is possible to provide a glass article that has excellent brilliance and fire and changes color when exposed to different light sources. [Brief description of the drawings]

[0021] [Figure 1] 1 is a plan view of Samples Nos. 23, 24, and 31 in the examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The glass article of the present invention is characterized by containing, in mole percent, La2O3 0 to 70%, Nb2O5+Ta2O5+Gd2O3+ZrO2+TiO2+Ga2O3+B2O3+Al2O3 0% or more, and Ho2O3+Nd2O3 0 to 20% or more. The reasons for limiting the glass composition in this way are explained below. In the following explanation of the content of each component, "%" means "mol %" unless otherwise specified.

[0023] La2O3 is a component that forms a glass skeleton and increases the refractive index without decreasing the transmittance. It also has the effect of improving weather resistance. The content of La2O3 is more than 0 to 70%, preferably 5 to 68%, and particularly preferably 8 to 63%. If the content of La2O3 is too low, it becomes difficult to obtain the above effects. On the other hand, if the content of La2O3 is too high, it becomes difficult to vitrify.

[0024] Nb2O5, Ta2O5, Gd2O3, ZrO2, TiO2, Ga2O3, B2O3 and Al2O3 are components that increase the refractive index, reduce the Abbe number to achieve high dispersion, and expand the vitrification range. The content of Nb2O5+Ta2O5+Gd2O3+ZrO2+TiO2+Ga2O3+B2O3+Al2O3 is more than 0%, and is preferably 5% or more, 10% or more, 20% or more, and particularly 30% or more. If the content of Nb2O5+Ta2O5+Gd2O3+ZrO2+TiO2+Ga2O3+B2O3+Al2O3 is too low, it becomes difficult to obtain the above effects. On the other hand, the upper limit of the content of Nb2O5+Ta2O5+Gd2O3+ZrO2+TiO2+Ga2O3+B2O3+Al2O3 is preferably less than 100%, 99% or less, and particularly 95% or less, taking into consideration the contents of other components.

[0025] Each of the components Nb2O5, Ta2O5, Gd2O3, ZrO2, TiO2, Ga2O3, B2O3 and Al2O3 will be described in detail below.

[0026] Nb2O5 is a component that has a large effect of increasing the refractive index, and is a component that reduces the Abbe number and provides high dispersion. It also has the effect of widening the vitrification range. The content of Nb2O5 is preferably 0 to 80%, 0.5 to 75%, 1 to 73%, and particularly preferably 1.5 to 70%. If the content of Nb2O5 is too low, it becomes difficult to obtain the above effects. On the other hand, if the content of Nb2O5 is too high, it becomes difficult to vitrify.

[0027] Ta2O5 is a component that has a large effect of increasing the refractive index. However, if the content of Ta2O5 is too high, vitrification becomes difficult and the raw material cost tends to increase. Therefore, the content of Ta2O5 is preferably 0 to 60%, 0 to 50%, 0 to 45%, and particularly preferably 0.1 to 40%.

[0028] Gd2O3 is a component that increases the refractive index. It also has the effect of improving weather resistance. However, if the Gd2O3 content is too high, vitrification becomes difficult. Therefore, the Gd2O3 content is preferably 0 to 45%, 0.1 to 40%, 1 to 35%, 3 to 30%, and particularly preferably 5 to 20%.

[0029] ZrO2 is a component that increases the refractive index. In addition, since it forms a glass skeleton as an intermediate oxide, it has the effect of widening the vitrification range. However, if the content of ZrO2 is too high, vitrification becomes difficult and the melting temperature becomes too high. Therefore, the content of ZrO2 is preferably 0 to 40%, 0.1 to 35%, 1 to 30%, 3 to 25%, and particularly preferably 5 to 20%.

[0030] TiO2 is a component that is highly effective in increasing the refractive index, and also has the effect of increasing chemical durability. It also has the effect of decreasing the Abbe number and increasing dispersion. The TiO2 content is preferably 0-90%, 0.1-88%, 5-86%, and particularly preferably 10-83%. If the TiO2 content is too high, the absorption edge shifts to the long wavelength side, making it easier for the transmittance of visible light (especially visible light in the short wavelength range) to decrease. Also, it becomes difficult to vitrify.

[0031] Ga2O3 is a component that increases the refractive index. In addition, since it forms a glass skeleton as an intermediate oxide, it has the effect of widening the vitrification range. However, if the Ga2O3 content is too high, vitrification becomes difficult and the raw material cost tends to increase. Therefore, the Ga2O3 content is preferably 0 to 50%, 0 to 30%, 0 to 20%, and particularly 0 to 10%.

[0032] B2O3 is a component that forms a glass skeleton and expands the vitrification range. However, if the content of B2O3 is too high, the refractive index decreases and it becomes difficult to obtain the desired optical properties. Therefore, the content of B2O3 is preferably 0 to 50%, 0.1 to 40%, 3 to 38%, and particularly preferably 5 to 37%.

[0033] Al2O3 is a component that forms a glass skeleton and expands the vitrification range. However, if the content of Al2O3 is too high, the refractive index decreases and it becomes difficult to obtain the desired optical properties. Therefore, the content of Al2O3 is preferably 0 to 80%, 1 to 75%, and particularly preferably 3 to 70%.

[0034] In order to obtain optical properties of high refractive index and high dispersion, it is preferable to adjust the content of Nb2O5+Ta2O5+Gd2O3+ZrO2+TiO2+Ga2O3. The content of Nb2O5+Ta2O5+Gd2O3+ZrO2+TiO2+Ga2O3 is preferably 0% or more, more than 0%, 5% or more, 10% or more, 15% or more, and particularly 20% or more. However, if the content of Nb2O5+Ta2O5+Gd2O3+ZrO2+TiO2+Ga2O3 is too high, it becomes difficult to vitrify, so it is preferable to make it less than 100%, 99% or less, and particularly 95% or less.

[0035] In order to facilitate vitrification, it is preferable to adjust the content of B2O3+Al2O3. The content of B2O3+Al2O3 is preferably 0% or more, 0.1% or more, 3% or more, and particularly preferably 5% or more. However, if the content of B2O3+Al2O3 is too high, the refractive index decreases and it becomes difficult to obtain the desired optical properties, so it is preferable that the content is 80% or less, 75% or less, and particularly preferably 70% or less.

[0036] The glass article of the present invention is made of La2O3, Nb2O 5、 By actively incorporating components such as TiO2 and B2O3 that expand the vitrification range, inappropriate crystallization during glass production is suppressed, making it easier to increase the size of the glass article (for example, a diameter of 2 mm or more, 3 mm or more, 4 mm or more, and particularly 5 mm or more).

[0037] Ho2O3 and Nd2O3 are components that change the color tone of the glass article when exposed to different light sources. The content of Ho2O3+Nd2O3 is preferably more than 0 to 20%, 0.1 to 15%, 0.2 to 10%, and particularly preferably 0.3 to 5%. If the content of Ho2O3+Nd2O3 is too low, it is difficult to obtain the above effects. On the other hand, if the content of Ho2O3+Nd2O3 is too high, it is difficult to vitrify. The content of each of the Ho2O3 and Nd2O3 components is preferably 0 to 20%, more than 0 to 20%, 0.1 to 15%, 0.2 to 10%, and particularly preferably 0.3 to 5%.

[0038] The glass article of the present invention may contain the following components in addition to those described above.

[0039] SiO2 is a component that forms a glass skeleton and expands the vitrification range. However, if the SiO2 content is too high, the refractive index decreases and it becomes difficult to obtain the desired optical properties. Therefore, the SiO2 content is preferably 0 to 40%, 0 to 30%, and particularly preferably 0.1 to 20%.

[0040] MgO, CaO, SrO, BaO, and ZnO are components that expand the vitrification range. Each of these components can be contained within a range of 10% or less. If the content of these components is too high, the refractive index decreases, making it difficult to obtain the desired optical properties.

[0041] Y2O3 is a component that increases the refractive index and expands the vitrification range. Y2O3 can be contained in the range of 20% or less. If the Y2O3 content is too high, vitrification becomes difficult.

[0042] By adding a coloring component consisting of an oxide of V, Cr, Mn, Fe, Co, Ni, Cu, Mo, Ru, Ce, Pr, or Er, the glass article can be adjusted to a desired color tone. These coloring components may be added alone or in combination of two or more. The content of these oxides (total amount when two or more are added) is preferably 0 to 20%, 0.001 to 10%, 0.005 to 5%, and particularly preferably 0.01 to 1%. Depending on the component added, the coloring may be too strong, the visible transmittance may decrease, and the desired brilliance or fire may not be obtained. In that case, the content of the above oxides may be less than 1%, 0.5% or less, or even 0.1% or less.

[0043] In addition, examples of glass articles according to another aspect of the present invention include those having the following glass compositions A to C. The reasons for limiting the content of each component in glass compositions A to C are the same as those mentioned above.

[0044] (Glass composition A) It contains, in mole percent, more than 70% La2O3 (preferably 5 to 50%, more preferably 7 to 40%), more than 0% Nb2O5+Ta2O5+Gd2O3+ZrO2+TiO2+Ga2O3 (preferably 10 to 99%, more preferably 30 to 95%, particularly preferably 50 to 90%), and more than 20% Ho2O3+Nd2O3 (preferably 0.1 to 15%, more preferably 0.2 to 10%, and even more preferably 0.3 to 5%).

[0045] (Glass composition B) It contains, in mole percent, more than 70% La2O30 (preferably 10 to 67%, more preferably 20 to 65%), more than 80% B2O3 + Al2O30 (preferably 10 to 75%, more preferably 20 to 73%, and even more preferably 30 to 72%), and more than 20% Ho2O3 + Nd2O30 (preferably 0.1 to 15%, more preferably 0.2 to 10%, and even more preferably 0.3 to 5%).

[0046] (Glass composition C) It contains, in mole percent, more than 70% La2O3 (preferably 5 to 65%, more preferably 10 to 60%), more than 0% Nb2O5+Ta2O5+Gd2O3+ZrO2+TiO2+Ga2O3 (preferably 5 to 90%, more preferably 10 to 80%), more than 80% B2O3+Al2O3 (preferably 3 to 70%, more preferably 5 to 65%), and more than 20% Ho2O3+Nd2O3 (preferably 0.1 to 15%, more preferably 0.2 to 10%, and even more preferably 0.3 to 5%).

[0047] The glass article of the present invention preferably has a refractive index (nd) of 1.7 or more, 1.8 or more, 1.9 or more, particularly 2.0 or more. This increases the difference in refractive index between the inside and outside (atmosphere) of the glass article, making it easier for light to be reflected inside the glass article. As a result, it becomes easier to obtain sufficient brightness as a decorative glass article. There is no particular upper limit to the refractive index, but if it is too high, vitrification becomes unstable, so it is preferably 2.6 or less, 2.5 or less, particularly 2.4 or less.

[0048] The Abbe number (νd) of the glass article of the present invention is preferably 45 or less, less than 45, 44 or less, and particularly preferably 41 or less. In this way, the glass article becomes highly dispersible and fire is easily generated. Although there is no particular restriction on the lower limit of the Abbe number, if it is too small, vitrification becomes unstable, so it is preferably 10 or more, and particularly preferably 15 or more.

[0049] The glass article of the present invention changes color when exposed to different light sources. Specifically, it exhibits a first color tone when exposed to sunlight, and exhibits a second color tone different from the first color tone when exposed to fluorescent light. It can be said that sunlight and fluorescent light are light sources to which glass articles are likely to be exposed in daily life. Therefore, when the color tone of a glass article changes when exposed to sunlight and when exposed to fluorescent light, the change in color tone can be frequently observed in daily life, and therefore, it is suitable for use as decoration such as pseudo-jewelry.

[0050] By changing the light source during observation from sunlight to fluorescent light, the color tone changes, for example, from yellow to pink, green to purple, purple to light blue, blue to purple, and purple to green. The reasons for this change in color tone are thought to be as follows.

[0051] Sunlight has a broad emission spectrum in the visible range, whereas fluorescent light has a sharp emission spectrum in each wavelength of R (red), G (green), and B (blue). Ho2O3 and Nd2O3 contained in the glass article are coloring components and have multiple absorption peaks in the visible range, but have a particularly large and sharp absorption peak near the peak position of the blue light of the fluorescent light. When a glass article containing Ho2O3 or Nd2O3 is exposed to sunlight, even if some wavelengths near the blue light are absorbed, light close to the blue wavelength in the vicinity of the relevant wavelength is not absorbed, so that the balance of RGB is unlikely to be lost as a whole. On the other hand, when a glass article containing Ho2O3 or Nd2O3 is exposed to a fluorescent light, the sharp blue light component of the fluorescent light is largely absorbed, causing the balance of RGB colors to be lost and the color tone to change.

[0052] Since LED light also has a relatively broad emission spectrum, a change in color tone can be observed when the glass article of the present invention is exposed to LED light and when it is exposed to fluorescent light, due to a mechanism similar to that described above.

[0053] The glass article of the present invention can be used for decorative purposes such as jewelry, art, and tableware. For example, it can be attached as a pseudo-gemstone to decorative items (jewelry) such as rings, pendants, earrings, and bracelets. The shape of the decorative glass article is not particularly limited, and examples include a sphere, an ellipse, and a polyhedron.

[0054] The glass article of the present invention is preferably subjected to chamfering such as so-called brilliant cut, step cut, mixed cut, etc. In this way, light is easily reflected inside the glass article, making it possible to enhance the brilliance, and it is particularly suitable as a pseudo-gemstone. EXAMPLES

[0055] The glass article of the present invention will be described in detail below using examples, but the present invention is not limited to the following examples.

[0056] Tables 1 to 4 show examples of the present invention (Nos. 1 to 33) and comparative examples (Nos. 34 to 36).

[0057] [Table 1]

[0058] [Table 2]

[0059] [Table 3]

[0060] [Table 4]

[0061] First, raw materials were mixed to prepare raw material batches so as to obtain the glass compositions shown in the table. The obtained raw material batches were melted until homogeneous, and then rapidly cooled to obtain glass samples. The melting temperatures were 1500-2000°C for samples No. 1-33, and 1400-1500°C for samples No. 34-36. The obtained glass samples were annealed near the glass transition temperature (450-720°C), and then the refractive index (nd) and Abbe number (νd) were measured and the appearance (color change, brilliance, fire) were evaluated by the following methods.

[0062] The refractive index and Abbe number were measured by polishing the glass samples at a right angle and using a precision refractometer (Shimadzu KPR-2000). The refractive index was evaluated using the measured value for the d-line (587.6 nm) of a helium lamp. The Abbe number was calculated from the Abbe number (νd) = {(nd-1) / (nF-nC)} using the refractive index of the d-line and the refractive index of the F-line (486.1 nm) and C-line (656.3 nm) of a hydrogen lamp.

[0063] Appearance evaluation was performed as follows. First, brilliant processing was performed on each sample so that the planar shape was about 5 to 7 mmφ. Regarding color change, the color observed near a window where sunlight entered indoors was compared with the color observed indoors under fluorescent lights where sunlight did not enter. Next, the processed glass samples were visually evaluated for brilliance and fire under a fluorescent light source. Evaluation was performed on the following four-point scale. Planar photographs of samples No. 23, 24, and 31 are shown in Figure 1.

[0064] [Shining] ◎: Looks shiny and has a strong shine. ○: Looks shiny. △: It looks slightly shiny. ×: Almost no shine (same as a glass window).

[0065] [fire] ◎: Iridescent (various colors) sparkle can be seen. ○: Iridescent glow is visible, but the number of colors is limited. △: A slight rainbow glow is visible. ×: The rainbow color is barely visible.

[0066] As is clear from Table 1, the samples No. 1 to No. 33, which are examples, changed color tone depending on the light source, and were good, with brilliance rated as ◎ and fire rated as ◯ to ◎. On the other hand, the sample No. 34, which is a comparative example, was rated as × for brilliance, and the sample No. 35 was rated as × for both brilliance and fire. Moreover, the sample No. 36 was rated as × for both brilliance and fire, and there was no change in color tone depending on the light source.

Claims

1. In mole percent, La ２ O ３ More than 0 to 70%, Nb ２ O ５ +Ta ２ O ５ +Gd ２ O ３ + ZrO ２ + TiO ２ +Ga ２ O ３ +B ２ O ３ +Al ２ O ３ More than 0% and Ho ２ O ３ +Nd ２ O ３ A glass article containing more than 0 to 20%.

2. In mole percent, Nb ２ O ５ +Ta ２ O ５ +Gd ２ O ３ + ZrO ２ + TiO ２ +Ga ２ O ３ The glass article according to claim 1, characterized in that it contains more than 0%.

3. In mole percent, B ２ O ３ +Al ２ O ３ 3. The glass article according to claim 1, wherein the glass article contains more than 0 to 80%.

4. In mole percent, La ２ O ３ More than 0 to 70%, Nb ２ O ５ +Ta ２ O ５ +Gd ２ O ３ + ZrO ２ + TiO ２ +Ga ２ O ３ More than 0% and Ho ２ O ３ +Nd ２ O ３ A glass article containing more than 0 to 20%.

5. In mole percent, La ２ O ３ More than 0 to 70%, B ２ O ３ +Al ２ O ３ More than 0 to 80%, and Ho ２ O ３ +Nd ２ O ３ A glass article containing more than 0 to 20%.

6. In mole percent, La ２ O ３ More than 0 to 70%, Nb ２ O ５ +Ta ２ O ５ +Gd ２ O ３ + ZrO ２ + TiO ２ +Ga ２ O ３ More than 0%, B ２ O ３ +Al ２ O ３ More than 0 to 80%, and Ho ２ O ３ +Nd ２ O ３ A glass article containing more than 0 to 20%.

7. 7. The glass article according to any one of claims 1 to 6, characterized in that it contains, in mole percent, 0 to 20% of a coloring component made of an oxide of V, Cr, Mn, Fe, Co, Ni, Cu, Mo, Ru, Ce, Pr or Er.

8. 8. The glass article according to claim 1, wherein the glass article has a refractive index of 1.7 or more and an Abbe number of 45 or less.

9. 9. The glass article according to claim 1, which exhibits a first color tone when exposed to sunlight, and exhibits a second color tone different from the first color tone when exposed to fluorescent light.

10. 10. The glass article according to claim 1, which is subjected to a chamfering process.

11. The glass article according to any one of claims 1 to 10, which is for decorative purposes.

12. 12. The glass article of claim 11, which is a simulated gemstone.

13. A decorative article comprising the glass article according to claim 11 or 12.

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