Glass containing fine metal particles and a method for manufacturing it.

Abstract

The present invention provides a metal fine particle-containing glass from which it is possible to obtain a high quality glass in which unnecessary coloring and defects which occur during manufacturing when being subjected to an oxidation treatment are suppressed. A metal fine particle-containing glass according to the present invention contains metal fine particles. The number densities of the metal fine particles for respective particle sizes in an arbitrary cross-section are: 0-1000 particles / mm2 for particles having a diameter greater than 1 µm but not greater than 5 µm; 0-30 particles / mm2 for particles having a diameter greater than 5 µm but not greater than 10 µm; 0-5 particles / mm2 for particles having a diameter greater than 10 µm but not greater than 100 µm; and 0-0.5 particles / mm2 for particles having a diameter greater than 100 µm but not greater than 500 µm. Particles having a diameter greater than 500 µm are substantially not contained. The proportion of area occupied by the metal fine particles in an arbitrary cross-section is 0-0.15% with respect to the total area.

Description

1 / 60 “GLASS CONTAINING FINE METAL PARTICLES AND METHOD FOR MANUFACTURING THE SAME”

[001] TECHNICAL FIELD

[002] The present invention relates to a glass containing fine metal particles and to a method of producing it.

[003] BACKGROUND OF THE TECHNIQUE

[004] From the point of view of resource recycling and greenhouse gas reduction, recycling a glass product is desirable. However, currently, most discarded glass products and some of the defective glass generated in an intermediate step are discarded without being recycled.

[005] The reason is, for example, the following. (1) When glass mixed with a foreign substance (hereinafter also referred to as an external foreign substance), such as a metal, a ceramic or an organic substance, is loaded into a melting furnace, various production defects are generated and therefore it is difficult to recycle the glass. (2) Because colored glass includes glass of various colors and it is difficult to collect the glass individually once the glass is mixed, it is difficult to horizontally recycle the glass to the same color as the glass before recycling. (3) Because the glass of a solar panel (hereinafter also referred to as a photovoltaic panel) contains Sb, the glass is colored in a flotation bath and therefore it is difficult to recycle the glass into a glass plate by a flotation method.

[006] That is, in the case where residual glass or defective glass contains an external foreign substance or the glass contains a coloring component or an unnecessary component, even when attempting to produce glass using the above as raw material, the glass obtained may have a production defect or discoloration. Petition 870250080496, dated 08 / 09 / 2025, page 75 / 146 2 / 60 unnecessary.

[007] In this regard, for example, Non-Patent Literature 1 describes that a phase separation phenomenon of an alkali-containing borosilicate glass is used for a method of removing an Fe component, which is a coloring component, from a glass.

[008] LIST OF QUOTATIONS

[009] UNPATENTED LITERATURE

[0010] Non-patent Literature 1: Takuya Imaoka and three others, Material Recycling of Municipal Waste Slags by Using Phase Separation of Glass, Journal of the Faculty of Environmental Science and Technology, Okayama University, 12(1), (2007) 161-165.

[0011] SUMMARY OF THE INVENTION

[0012] TECHNICAL PROBLEM

[0013] However, in the case of removing the dye component or similar from glass using the phase separation phenomenon, as described in Non-Patent Literature 1, the step is complicated and the efficiency may be low. In addition, useful components, such as an alkali metal oxide component, are also removed at the same time.

[0014] In view of the foregoing, an objective of the present invention is to provide a glass containing fine metal particles in which an unnecessary substance or component is appropriately removed from a glass containing an external foreign substance or a glass containing a coloring component or unnecessary component, and from which a high-quality glass with few production defects and reduced unnecessary coloration during an oxidation treatment can be obtained.

[0015] SOLUTION TO THE PROBLEM

[0016] That is, the present invention relates to the following items 1 to 12. 1. A glass containing fine metal particles, which is a glass. Petition 870250080496, dated 08 / 09 / 2025, page 76 / 146 3 / 60 containing fine metal particles, in which the number density of fine metal particles for each particle diameter in any cross-section of the glass is in the following ranges, and the area ratio of fine metal particles in any cross-section of the glass is from 0% to 0.15% relative to the total area of ​​any cross-section,

[0017] Particle diameter greater than 1 μm and 5 μm or less: 0 to 1,000 particles / mm2,

[0018] particle diameter of more than 5 μm and 10 μm or less: at 30 particles / mm2,

[0019] Particle diameter of more than 10 μm and 100 μm or less: 0 to 5 particles / mm2,

[0020] Particle diameter of more than 100 μm and 500 μm or less: 0 to 0.5 particles / mm2,

[0021] Particle diameter of more than 500 μm: substantially not contained.

[0022] 2. Glass containing fine metal particles, according to item 1 above, in which an absolute ABS (Tv-Tiioo) value of a difference between a visible light transmittance Tv at a thickness of 2 mm and a transmittance T1100 at a wavelength of 1100 nm at a thickness of 2 mm is 30% or less.

[0023] 3. Glass containing fine metal particles, according to item 1 or 2 above, in which the fine metal particles contain at least one element selected from the group consisting of Fe, Si, Co, Cr, Ni, Ti, P, Sb, W and Nb.

[0024] 4. Glass containing fine metal particles, according to item 1 or 2 above, wherein a fusion obtained by melting glass containing fine metal particles is subjected to a bubbling oxidation treatment using an atmosphere at 1,500°C for Petition 870250080496, dated 08 / 09 / 2025, page 77 / 146 4 / 60 It takes 120 minutes to obtain a glass; the resulting glass has a visible light transmittance (Tv) of 50% or more at a thickness of 2 mm.

[0025] 5. Glass containing fine metal particles, according to item 1 or 2 above, wherein, in terms of % by mass on an oxide basis, when a melt obtained by melting glass containing fine metal particles is subjected to a bubbling oxidation treatment using an atmosphere at 1,500°C for 120 minutes to obtain a glass, an NWF ratio after / before is 0.40 to 1.50, the NWF ratio after / before being a ratio of the total content of a network-forming oxide in the glass obtained to a total content of the network-forming oxide in the glass containing fine metal particles, and an NWM ratio after / before is 0.60 to 2.00, the NWM ratio after / before being a ratio of the total content of a network-modifying oxide in the glass obtained to a total content of the network-modifying oxide in the glass containing fine metal particles.

[0026] 6. Glass containing fine metal particles, according to item 1 or 2 above, wherein an average concentration of Fe2O3 in the glass containing fine metal particles is 0.001% to 0.5% in terms of % by mass based on oxides.

[0027] 7. Glass containing fine metal particles, according to item 1 or 2 above, wherein when a melt obtained by melting glass containing fine metal particles is subjected to a bubbling oxidation treatment using an atmosphere at 1,500°C for 30 minutes to obtain a glass, the glass obtained substantially does not contain fine metal particles with a particle diameter of 1 μm or more.

[0028] 8. Glass containing fine metal particles, according to item 1 or 2 above, in which a shape occupying 80% or more on a mass basis is a crushed piece shape or a shape Petition 870250080496, dated 08 / 09 / 2025, page 78 / 146 5 / 60 spherical with a size of 1 mm to 100 mm.

[0029] 9. A method for producing glass containing fine metal particles, which is a method for producing glass containing fine metal particles, according to 1 or 2 above, the method including: obtaining a melt by melting a glass-containing feedstock; and subjecting the melt to a reduction treatment.

[0030] 10. The method for producing a glass containing fine metallic particles, according to item 9 above, in which in the reduction treatment, at least one selected from the group consisting of a simple substance and a compound containing at least one element selected from the group consisting of C, Al, Si, Ca, Ti and H, and a mixture containing the simple substance and the compound is used as a reducing agent.

[0031] 11. The method for producing a glass containing fine metallic particles, according to item 10 above, in which the reducing agent contains at least one selected from the group consisting of a simple substance and a compound containing at least one element selected from the group consisting of C, Si and H, and a mixture containing the simple substance and the compound.

[0032] 12. The method for producing a glass containing fine metallic particles according to 9 above, in which a treatment temperature in the reduction treatment is 1,300°C to 1,800°C.

[0033] EFFECTS AND ADVANTAGES OF THE INVENTION

[0034] Since, in glass containing fine metal particles, according to the present invention, an unnecessary substance or component is appropriately removed from glass containing an external foreign substance or glass containing a coloring component or unnecessary component, and fine metal particles having a particle diameter distribution Petition 870250080496, dated 08 / 09 / 2025, page 79 / 146 If the specified 6 / 60 are contained, a high-quality glass with few manufacturing defects and reduced unnecessary discoloration during an oxidation treatment can be obtained.

[0035] BRIEF DESCRIPTION OF THE DRAWINGS

[0036] [Figure 1A] Figure 1A is a diagram showing an example of an image obtained by capturing a glass containing fine metal particles, according to the present embodiment, with a magnification of 200 times by a predetermined method.

[0037] [Figure 1B] Figure 1B is a diagram showing an image obtained by performing the image processing in Figure 1A.

[0038] [Figure 2A] Figure 2A is a diagram showing an example of an image obtained by capturing glass containing fine metal particles, according to the present embodiment, with a magnification of 1,000 times by a predetermined method.

[0039] [Figure 2B] Figure 2B is a diagram showing an image obtained by performing the image processing in Figure 2A.

[0040] DESCRIPTION OF MODALITIES

[0041] The present invention is described in detail below, but the present invention is not limited to the following embodiment and may be freely modified and implemented without departing from the essence of the present invention.

[0042] In the present description, a indicates a numerical range and is used to include the numerical values ​​set before and after a as a lower limit value and an upper limit value. Furthermore, in the present description, mass is synonymous with weight.

[0043] A glass containing fine metal particles, according to one embodiment of the present invention, is a glass containing fine metal particles, in which the numerical density of the fine metal particles for each particle diameter is in the following ranges, and the area ratio of the fine metal particles in any section Petition 870250080496, dated 08 / 09 / 2025, page 80 / 146 7 / 60 of the cross-sectional area of ​​the glass is 0% to 0.15% relative to the total area of ​​any cross-section.

[0044] Particle diameter greater than 1 μm and 5 μm or less: 0 to 1,000 particles / mm2

[0045] Particle diameter greater than 5 μm and 10 μm or less: 0 to 30 particles / mm2

[0046] Particle diameter of more than 10 μm and 100 μm or less: 5 particles / mm2

[0047] Particle diameter of more than 100 μm and 500 μm or less: 0 to 0.5 particles / mm2

[0048] Particle diameter greater than 500 μm: substantially not contained

[0049] In the present description, fine metal particles in glass are observed by epi-illumination using an optical microscope (digital microscope). Using epi-illumination, surface-focused observation is easy, and since fine metal particles reflect light, high-contrast observation is possible. Specifically, glass containing fine metal particles is polished in any cross-section and then imaged at 16 positions with magnifications of 200x and 1000x, respectively. When performing image analysis using image analysis software, an area of ​​each particle included in a total of 32 captured images is calculated, and a diameter obtained when the area of ​​the particle obtained is assumed to be a sphere is defined as the particle diameter.Note that it is confirmed that the fine metal particles have a substantially spherical shape from the scanning electron microscope observation with energy-dispersive X-ray spectroscopy (SEM-EDX), to be described later, and that the fine metal particles correspond to the observation image obtained using the optical microscope. From the point of view of measurement accuracy, only particles with a diameter... Petition 870250080496, dated 08 / 09 / 2025, page 81 / 146 8 / 60 of particles larger than 5 μm are counted at 200x magnification, and only particles with a diameter greater than 1 μm to 5 μm are counted at 1000x magnification. Furthermore, the particle diameter distribution of each image is obtained by image analysis, and the numerical density for each particle diameter of the fine metallic particles is obtained by dividing the number of specific particle diameters observed by the total area of ​​the observed image's field of view. Additionally, the ratio between the areas of the fine metallic particles is obtained by dividing the total area of ​​the observed fine metallic particles by the total area of ​​the observed image's field of view. Note that fine metallic particles with a specific particle diameter are not substantially contained means that fine metallic particles with the corresponding particle diameter are not observed by the above method.

[0050] Figure 1A is a diagram showing an example of an image obtained by capturing glass containing fine metal particles, according to the present embodiment, with a magnification of 200 times by the method described above. Figure 1B is a diagram showing an image obtained by performing the image processing in Figure 1A. Figure 2A is a diagram showing an example of an image obtained by capturing glass containing fine metal particles, according to the present embodiment, with a magnification of 1,000 times by the method described above. Figure 2B is a diagram showing an image obtained by performing the image processing in Figure 2A.

[0051] In the present description, an element concentration (composition) in glass containing fine metal particles means an average concentration (average composition) including elements contained in the glass and elements contained in the fine metal particles, unless otherwise specified.This can be measured by X-ray fluorescence analysis. Furthermore, a major component of... Petition 870250080496, dated 08 / 09 / 2025, page 82 / 146 9 / 60 fine metal particles can be measured by scanning electron microscopy with energy-dispersive X-ray spectroscopy (EDXSEM).

[0052] (Method for Producing Glass Containing Fine Metallic Particles)

[0053] Firstly, a method for producing a glass containing fine metallic particles, according to an embodiment of the present invention (hereinafter also referred to as the present production method) is described. The glass containing fine metallic particles, according to the embodiment of the present invention, is obtained by a method that includes obtaining a molten mass by melting a glass-containing raw material, and subjecting the molten mass to a reduction treatment. More specifically, this method includes, for example, the following steps (i) to (iii).

[0054] Step (i): obtain a first melt by melting a raw material containing glass.

[0055] Step (ii): precipitate a metallic phase by subjecting the first melt to a reduction treatment.

[0056] Step (iii): obtain a second melt by separating at least part of the metallic phase from the first melt.

[0057] In the present document, as will be described in detail later, the glass-containing raw material is a raw material containing, for example, glass containing an external foreign substance, glass containing a coloring component or an unnecessary component, or similar. The present inventor has discovered that, in glass containing an external foreign substance or glass containing a coloring component or an unnecessary component, when a molten mass thereof is subjected to a reduction treatment, impurity elements derived from the external foreign substance, the coloring component or the unnecessary component may be Petition 870250080496, dated 08 / 09 / 2025, page 83 / 146 10 / 60 precipitates as a metallic phase and separates from the molten mass. However, according to the present inventors' study, it was discovered that, in the case where the precipitated metallic phase is separated from the molten mass, the metallic phase in a fine particle state remains in the molten mass, although a certain amount of impurity elements is removed, and the fine metal particles become defects in the glass to be obtained. Therefore, the present inventors discovered that, by further performing an oxidation treatment on the melt in which the metallic phase in a fine particle state remains, the metallic phase in a fine particle state is oxidized and contained in the glass in an oxide state (i.e., the fine particles can be eliminated).

[0058] In particular, the present inventors have discovered that by defining a particle diameter distribution of the metallic phase in a fine particle state within a specific range, it is possible to avoid the persistence of fine particles after oxidation treatment and a decrease in the transparency of the glass to be obtained after oxidation treatment, making it easy to obtain high-quality glass. Thus, the present invention has been completed. That is, in the case where the particle diameter distribution in glass containing fine metal particles is not appropriate, in particular, in the case where coarse particles are contained or a large residual amount of fine metal particles is present, fine particles remain in the glass after oxidation treatment, or the amount of impurity elements contained in the glass increases when fine metal particles are removed, which will likely cause defects or discoloration.In contrast, according to the present invention, defects and discoloration after oxidation treatment can be more reliably reduced, and high-quality glass can be obtained.

[0059] [Step (i)] Petition 870250080496, dated 08 / 09 / 2025, page 84 / 146 11 / 60

[0060] In step (i), a raw material containing glass is melted to obtain a first melt.

[0061] (Raw material containing glass)

[0062] Raw materials containing glass are not particularly limited, and examples thereof include raw materials containing, for example, glass containing an external foreign substance, glass containing a coloring component or an unnecessary component, or the like.

[0063] Examples of glass containing a foreign external substance include a mixture containing a glass and a substance other than glass, a mixture of a plurality of glasses with different major compositions, and a composite in which a substance other than glass adheres to the glass. In the present document, the major composition means a composition of a major oxide that constitutes the glass and, specifically, means, for example, a composition of a network-forming oxide such as SiO2, AbOs, B2O3 and P2O5, or a network-modifying oxide such as an alkaline earth metal oxide and an alkali metal oxide. The foreign external substance is not particularly limited, and examples thereof include a metal, a ceramic, an organic substance, and a composite material containing an organic substance and an inorganic substance. Representative examples thereof are shown below.Examples of metal include cast iron, stainless steel, aluminum, copper, silver, silicon, lead, zinc, tin, solder, and a heating wire (containing primarily Ag as the main component) to be applied to the glass of an automobile window. Examples of ceramic include concrete, cement, pottery, a heat-resistant plate, a black ceramic print (commonly called black enamel) to be applied to the glass of an automobile window, and a drying agent, such as zeolite, to be used in insulating glass. Examples of organic substances include... Petition 870250080496, dated 08 / 09 / 2025, page 85 / 146 12 / 60 sealing material, an interlayer, paper, wood, a plastic, and a bottle label seal. Examples of composite material containing an organic substance and an inorganic substance include a base material to be used in a printed circuit board and a fiber-reinforced plastic.

[0064] According to the present production method, as an impurity element, derived from these external foreign substances contained in the first melt, can be adequately removed, the defects of the glass to be obtained after the oxidation treatment in the glass containing fine metal particles can be reduced, resulting in obtaining a high-quality glass. Note that, in the case where the external foreign substance is, for example, an organic substance, an impurity derived from it is not necessarily separated as a metallic phase in step (ii). However, as will be described later, according to the present production method, the defects derived from the organic substance can also be reduced.

[0065] Firstly, most of the organic substance is gasified and removed by burning in the melting process in step (i). On the other hand, a portion of it remains in the molten mass as a residual carbon component and acts as a reducing agent for the reduction of the glass. It is believed that such a residual carbon component, if left as is, will lead to defects. However, the degree of reduction by the residual carbon component is less than that obtained in a reduction treatment step in the subsequent step (ii), and the influence can be completely eliminated by subjecting the glass containing fine metal particles to an oxidation treatment. Therefore, according to the present production method, the defects derived from the organic substance in the glass to be obtained after the oxidation treatment in the glass containing fine metal particles can also be reduced.

[0066] In the case where the raw material containing glass contains the Petition 870250080496, dated 08 / 09 / 2025, page 86 / 146 13 / 60 external foreign substance, the content of the external foreign substance in the glass-containing raw material is, for example, preferably 0.1 ppm by mass or more, more preferably 1 ppm by mass or more, and even more preferably 10 ppm by mass or more, from the point of view of adequately obtaining the effects of the present invention. On the other hand, the content of the external foreign substance in the glass-containing raw material is preferably 100,000 ppm by mass or less, more preferably 50,000 ppm by mass or less, and even more preferably 30,000 ppm by mass or less, from the point of view of improving the quality of the glass to be obtained after oxidation treatment in glass containing fine metal particles. That is, the content of the external foreign substance in the glass-containing raw material is preferably in the range of 0.1 ppm by mass to 100,000 ppm by mass.

[0067] Examples of the impurity element derived from the external foreign substance, the coloring component, or the unnecessary component include Fe, Co, Cr, Ni, Sb, Zn, Mn, Sn, Bi, Pb, Ag, Cu, W, and Nb. These elements tend to be reduced more easily than the main component of the glass. According to the present production method, since these impurity elements contained in the first melt can be adequately removed, the coloration of the glass to be obtained can be reduced and a glass with excellent transparency can be obtained. Hereinafter, the impurity element in the present description means at least one element selected from the group consisting of Fe, Co, Cr, Ni, Sb, Zn, Mn, Sn, Bi, Pb, Ag, Cu, W, and Nb. The impurity element is preferably at least one element selected from the group consisting of Fe, Co, Cr, Ni, and Sb.

[0068] In the case where the raw material containing glass contains the impurity element, its content preferably satisfies one or more of the following (1) to (14) when a composition of the raw material Petition 870250080496, dated 09 / 08 / 2025, p. 87 / 146 14 / 60 containing glass is expressed in terms of % by mass or ppm by mass based on oxides. In this case, it can be said that the glass-containing raw material contains an impurity element to some extent, and the effects of the present production method can be adequately obtained. Note that, in the present description, the composition of the glass-containing raw material refers to an average composition of a complete composition, including the case where the glass-containing raw material is a mixture or composite containing an external foreign substance. The composition of the glass-containing raw material can be measured by appropriately selecting the method described in JIS K0050:2019 General rules for chemical analysis.It is preferable to melt the glass-containing raw material in the atmosphere and subject the resulting composition to X-ray fluorescence (XRF) analysis, analysis using an electron probe microanalyzer (EPMA), ICP optical emission spectrometry, or ICP mass spectrometry, since the average composition of an entire composition can be measured with relative ease. (1) Fe2O3: 0.001% by mass or more (2) CoO: 1 ppm by mass or more (3) Cr2O3: 1 ppm by mass or more (4) NiO: 1 ppm by mass or more (5) Sb2O3: 1 ppm by mass or more (6) ZnO: 1 ppm by mass or more (7) MnO: 1 ppm by mass or more (8) SnO2: 1 ppm by mass or more (9) Bi2O3: 1 ppm by mass or more (10) PbO: 1 ppm by mass or more (11) Ag2O: 1 ppm by mass or more (12) CuO: 1 ppm by mass or more (13) WO3: 1 ppm by mass or more Petition 870250080496, dated 08 / 09 / 2025, page 88 / 146 15 / 60 (14) Nb2U5: 1 ppm by mass or more

[0069] In the present production method, although the raw material containing glass with a certain amount of the impurity element is suitable, the content of the impurity element is preferably not very high, considering the quality of the glass to be obtained after the oxidation treatment in the glass containing fine metal particles. From this point of view, in the raw material containing glass, the Fe2O3 content is preferably 5% by mass or less, and more preferably 3% by mass or less. Furthermore, among the impurity elements, the content of each of the elements, except Fe, is preferably 10,000 ppm by mass or less, and more preferably 5,000 ppm by mass or less, in terms of ppm by mass based on oxides.For example, as the content of the impurity element in the case where the raw material containing glass contains the impurity element, it is more preferable to satisfy one or more of the following (1)' to (14)' in terms of % by mass or ppm by mass based on oxides.

[0070] (1)' Fe2Os: 0.001% by mass to 5% by mass

[0071] (2)' CoO: 1 to 10,000 ppm by mass

[0072] (3)' C2O3: 1 to 10,000 ppm by mass

[0073] (4)' NiO: 1 to 10,000 ppm by mass

[0074] (5)' Sb2O3: 1 to 10,000 ppm by mass

[0075] (6)' ZnO: 1 to 10,000 ppm by mass

[0076] (7)' MnO: 1 to 10,000 ppm by mass

[0077] (8)' SnO2: 1 to 10,000 ppm by mass

[0078] (9)' Bi2O3: 1 to 10,000 ppm in mass

[0079] (10)' PbO: 1 to 10,000 ppm by mass

[0080] (11)' Ag2O: 1 to 10,000 ppm by mass

[0081] (12)' CuO: 1 to 10,000 ppm by mass

[0082] (13)' WO3: 1 to 10,000 ppm by mass Petition 870250080496, dated 09 / 08 / 2025, p. 89 / 146 16 / 60

[0083] (14)' Nb2Ü5: 1 to 10,000 ppm by mass

[0084] Specific examples of glass-containing raw materials, as exemplified above, include raw materials derived from a waste glass product and defective glass generated in a glass product production process. If necessary, a fragment obtained by subjecting a waste glass product or defective glass to a treatment such as pulverization can be used as a glass-containing raw material. The type of glass product is not particularly limited, and examples include insulating glass, laminated glass, printed glass, photovoltaic panel glass, a glass bottle, glass wool, fireproof glass, heat-resistant glass, glass used for devices such as smartphones, and glass used for liquid crystal displays and the like.The raw material derived from such a glass product will likely be a material mixed with an external foreign substance, or a material containing a coloring component or an unnecessary component, and is suitable as a glass-containing raw material in the present production method. Furthermore, from the point of view of resource recycling and greenhouse gas reduction, it is preferable to use a waste glass product or defective glass as a glass-containing raw material, since glass can be recycled. The glass-containing raw material may contain an additive and a glass raw material different from the waste glass product and defective glass, for the purpose of adjusting the composition of the glass to be obtained or adjusting the viscosity of the molten mass, as described later.

[0085] From the point of view of efficient recycling, the cullet content in the raw material containing glass is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, and particularly preferably 80% by mass or more. Petition 870250080496, dated 08 / 09 / 2025, pp. 90 / 146 17 / 60

[0086] (First Merger)

[0087] The viscosity of the first melt is preferably 0.1 dPa.s ≤ 100,000 dPa.s at the temperature in step (ii), i.e., at the temperature during the reduction treatment. That is, the viscosity is preferably 100,000 dPa.s or less, more preferably 10,000 dPa.s or less, and even more preferably 1,000 dPa.s or less. When the viscosity is above or below the upper limit, the reduction treatment in step (ii) is easily carried out. The lower limit of viscosity is not particularly restricted and is preferably 0.1 dPa.s or more, from the point of view of preventing erosion of a refractory, for example. The viscosity of the first melt can be measured using a rotary cylinder method, a sphere extraction method or similar.

[0088] From the above viewpoints, the present production method may further include adjusting the viscosity of the first melt to 0.1 dPa^s s 10,000 dPa^s. A more preferred viscosity range is the same as described above.

[0089] A method for adjusting the viscosity of the first melt is not particularly limited, and examples of this include a method for adding a substance capable of adjusting the viscosity to the glass-containing feedstock or to the first melt. The substance that can be added to the glass-containing feedstock or to the first melt is not particularly limited, and examples of this include a carbonate, a hydroxide, an oxide, a fluoride, and a chloride containing an alkali metal element or an alkaline earth metal element when it is desired to relatively reduce the viscosity, and examples of this include an oxide containing silicon, aluminum, boron, or phosphorus when it is desired to relatively increase the viscosity.

[0090] [Step (ii)]

[0091] In step (ii), the first fusion is subjected to a treatment Petition 870250080496, dated 08 / 09 / 2025, page 91 / 146 18 / 60 reduction to precipitate a metallic phase.

[0092] (Reduction Treatment)

[0093] A reduction treatment method is not particularly limited, and examples include a method in which a reducing agent is used and a method in which the first melt is electrolyzed. From the point of view of ease of equipment maintenance and reduction of energy consumption, a method in which a reducing agent is used is preferable.

[0094] As a reducing agent in the reduction treatment, for example, at least one selected from the group consisting of a simple substance and a compound containing at least one element selected from the group consisting of C, Al, Si, Ca, Ti and H, and a mixture containing the simple substance and the compound may preferably be used from the point of view of availability.

[0095] Specific examples of the compound corresponding to these include C, Al, Si, Ca, Ti, H2, CO, an Fe-Si alloy, a Ca-Si alloy, CH4, NH3 and a mixture containing these.

[0096] From the point of view of cost reduction, the reducing agent most preferably contains at least one selected from the group consisting of a simple substance and a compound containing at least one element selected from the group consisting of C, Si and H, and a mixture containing the simple substance and the compound, even more preferably contains at least one selected from the group consisting of C, Si, CO, an Fe-Si alloy, H2, NH3 and CH4, and even more preferably contains C, Si, an Fe-Si alloy, H2 and NH3.

[0097] The state of the reducing agent is not particularly limited, and it can be a gas or a solid at room temperature. In the case where the reducing agent is a solid, its shape is not particularly limited, and it can be, for example, a granular shape, a powder shape, a lump shape or a plate shape. Petition 870250080496, dated 08 / 09 / 2025, page 92 / 146 19 / 60

[0098] As a reduction treatment method using a reducing agent, specifically, a treatment can be carried out in which the reducing agent and the first molten mass are brought into contact with each other. Examples of this include a method in which the first molten mass and the reducing agent are brought into contact with each other by adding a solid reducing agent to the first molten mass or by blowing a gaseous reducing agent into the first molten mass, and a method in which the glass-containing raw material is melted in a vessel in which a reducing agent is previously disposed to bring the first molten mass obtained into contact with the reducing agent. Note that the vessel in which a reducing agent is disposed includes not only a case in which the vessel contains the reducing agent, but also a case in which part or all of the vessel itself acts as a reducing agent.In the case of melting the raw material containing glass in a container in which a reducing agent is previously placed, step (i) and step (ii) are carried out simultaneously.

[0099] From the point of view of ease of operation, a method is preferable in which the glass-containing raw material is melted in a container in which a reducing agent is previously disposed.

[00100] In the case where the reducing agent is a granular or granulated solid and the glass-containing feedstock is melted in a vessel in which a reducing agent is previously disposed, a reducing agent size occupying 80% or more of the total mass is preferably from 0.5 mm to 200 mm. The reducing agent size occupying 80% or more of the total mass is more preferably from 1 mm to 150 mm, and even more preferably from 2 mm to 100 mm. Consequently, the size of the voids formed by the reducing agents can be adjusted, and the entire melted mass can be efficiently reduced. The size and proportion of the reducing agent can be evaluated by passing the reducing agent through a sieve with an opening Petition 870250080496, dated 08 / 09 / 2025, page 93 / 146 20 / 60 predetermined and measuring the mass with a balance. Note that a preferred range does not include a minute reducing agent generated by collision between reducing agents during addition or transport or a reaction with the molten mass.

[00101] In the case where the reducing agent is a solid and the glass-containing feedstock is melted in a container in which a reducing agent is previously placed, it is preferable to fill the container with the reducing agent at a filling rate of 20% by volume to 80% by volume and bring the reducing agent into contact with the first molten mass. That is, the filling rate is preferably 20% by volume or more, more preferably 30% by volume or more, and even more preferably 40% by volume or more. On the other hand, the filling rate is preferably 80% by volume or less, more preferably 75% by volume or less, and even more preferably 70% by volume or less. Consequently, the entire molten mass can be efficiently reduced.The filling rate of the reducing agent is obtained by calculation based on the mass of the reducing agent when a container with a given volume is filled with the reducing agent and on the apparent density of the reducing agent.

[00102] In the case where the reducing agent is a solid, the mass ratio of the reducing agent to the first melt mass is preferably from 0.001 to 100. That is, from the point of view of making the effect of the reduction treatment sufficient, the mass ratio is preferably 0.001 or more, more preferably 0.005 or more, and even more preferably 0.01 or more. On the other hand, from the point of view of a space-saving treatment, the mass ratio is preferably 100 or less, more preferably 50 or less, and even more preferably 30 or less. The mass ratio of the reducing agent to the first melt mass is obtained based on Petition 870250080496, dated 08 / 09 / 2025, page 94 / 146 21 / 60 an average composition and a charged quantity of the molten mass and an average composition and a charged quantity of the reducing agent. In the case of melting the raw material containing glass in a vessel in which a reducing agent is previously disposed of, the reduction treatment can be carried out provided that the reducing agent is not lost through a reaction with an oxidizing gas, such as oxygen contained slightly in a melt or atmosphere.

[00103] The reduction treatment method can be a method in which the first molten mass is electrolyzed, and this method and a method in which a reducing agent is used can be used in combination. In the case of electrolysis of the first molten mass, for example, electrolysis can be carried out by placing two electrodes in the first molten mass and applying a voltage between them.

[00104] The treatment temperature in the reduction treatment is preferably from 1,300°C to 1,800°C. That is, the treatment temperature is preferably 1,300°C or higher, more preferably 1,400°C or higher, and even more preferably 1,450°C or higher, from the point of view of obtaining a sufficient reduction reaction rate and reducing power. On the other hand, the treatment temperature is preferably 1,800°C or lower, more preferably 1,700°C or lower, and even more preferably 1,650°C or lower, from the point of view of preventing refractory erosion and reducing energy consumption.

[00105] The duration of the reduction treatment is not particularly limited, depending on the type of reducing agent, the composition of the first melt and the like, and is preferably, for example, from 10 minutes to 48 hours. That is, the treatment time is preferably 10 minutes or more, more preferably 30 minutes or more, and even more preferably 60 minutes or more, from the point of view of allowing the reduction reaction to proceed sufficiently. On the other hand Petition 870250080496, dated 08 / 09 / 2025, page 95 / 146 22 / 60 side, the treatment time is preferably 48 hours or less, more preferably 24 hours or less, and even more preferably 12 hours or less, from the point of view of preventing refractory erosion and reducing energy consumption.

[00106] In reduction treatment, it is preferable to selectively precipitate the impurity element in the first melt as a metallic phase. Consequently, the exchange between a major component of the glass in the glass-containing feedstock and a major component of the glass to be obtained is reduced, and recycling can be carried out properly while the useful component remains. To selectively precipitate the impurity element as a metallic phase, it is preferable to properly adjust conditions such as the type of reducing agent and the treatment temperature in the reduction treatment. For example, by setting them to the preferred conditions described above, the impurity element in the first melt tends to be selectively precipitated as a metallic phase.

[00107] (Metallic Phase)

[00108] The metallic element contained in the first melt is precipitated in the first melt as a metallic phase when subjected to the reduction treatment. The metallic phase contains at least one element contained in the glass-containing feedstock or contained in the first melt before the reduction treatment and, preferably, contains the aforementioned impurity elements. More preferably, as the proportion of the impurity element in the metallic phase increases, it can be said that the impurity element is selectively precipitated as a metallic phase.

[00109] [Step (iii)]

[00110] In step (iii), at least part of the metallic phase is separated from the first molten mass subjected to reduction treatment to obtain a second molten mass. In the present document, Petition 870250080496, dated 09 / 08 / 2025, p. 96 / 146 23 / 60 Separating at least part of the metallic phase from the first melt means physically removing at least part of the metallic phase from the first melt, and the second melt means a melt obtained by removing at least part of the metallic phase from the first melt.

[00111] The method of separating the metallic phase is not particularly limited, and examples of this are: a method in which the metallic phase precipitated in the first melt is deposited, becoming coarse enough to deposit fine metallic particles by bubbling to thus separate the metallic phase; a method in which the metallic phase is separated by linking the metallic phase and fine metallic particles precipitated by the intentional addition of a metallic component, such as silicon, to become a coarse metallic phase of sufficient size for deposition; a method by precipitating the metallic phase onto the surface of a reducing agent and trapping the metallic phase on the surface of the reducing agent; and a method in which the metallic phase is converted into a highly volatile substance by halogenation or similar to separate the metallic phase as a gas.These methods are preferred because it is easy to obtain a glass containing fine metallic particles, in which the number density for each particle diameter of the fine metallic particles is in the above ranges. From the point of view of ease of handling and high separation efficiency, the following are preferred: a method in which the metallic phase precipitated in the first melt is deposited, becoming coarse to a size sufficient to deposit fine metallic particles by bubbling, thus separating the metallic phase; a method in which the metallic phase is separated by bonding the metallic phase and fine metallic particles precipitated by the intentional addition of a metallic component, such as silicon, to become a coarse metallic phase to a size sufficient for deposition; and a method in which the metallic phase is separated. Petition 870250080496, dated 09 / 08 / 2025, p. 97 / 146 24 / 60 precipitating the metallic phase onto the surface of a reducing agent and capturing the metallic phase on the surface of the reducing agent, and more preferably is a method in which the metallic phase is separated by precipitating the metallic phase onto the surface of a reducing agent and capturing the metallic phase on the surface of the reducing agent. Note that, as a specific method capable of capturing the metallic phase on the surface of the reducing agent by precipitating the metallic phase onto the surface of a reducing agent, a method is exemplified by pre-filling a container with the reducing agent and melting the glass-containing feedstock in the container to pass the first molten mass through the reducing agent. Steps (ii) and (iii) can be performed simultaneously.

[00112] After steps (i) to (iii), the glass containing fine metallic particles, according to the embodiment of the present invention, is obtained from the second molten mass obtained. The present production method may include a cooling step of the second molten mass by a known method and a forming step of the second molten mass.

[00113] (Glass containing fine metallic particles)

[00114] The glass containing fine metal particles, according to the embodiment of the present invention, is a glass containing fine metal particles, and the numerical density of the fine metal particles for each particle diameter is in the following ranges. Consequently, it is possible to obtain a high-quality glass with few defects in production and reduced unnecessary discoloration during an oxidation treatment.

[00115] Particle diameter greater than 1 μm and 5 μm or less: 0 to 1,000 particles / mm2

[00116] Particle diameter greater than 5 μm and 10 μm or less: 0 to 30 particles / mm2 Petition 870250080496, dated 09 / 08 / 2025, p. 98 / 146 25 / 60

[00117] Particle diameter greater than 10 μm and 100 μm or less: 0 to 5 particles / mm2

[00118] Particle diameter of more than 100 μm and 500 μm or less: 0 to 0.5 particles / mm2

[00119] Particle diameter greater than 500 μm: substantially not contained

[00120] In glass containing fine metal particles, the number density of particles with a particle diameter greater than 1 μm and 5 μm or less is 0 to 1,000 particles / mm2. That is, the number density of particles with a particle diameter greater than 1 μm and 5 μm or less is 1,000 particles / mm2 or less, preferably 500 particles / mm2 or less, more preferably 400 particles / mm2 or less, even more preferably 300 particles / mm2 or less, and particularly preferably 200 particles / mm2 or less. Consequently, the visible light transmittance of the glass after oxidation treatment can be increased, and a high-quality glass can be obtained in a short oxidation treatment time.The numerical density of particles with a particle diameter greater than 1 μm and equal to or less than 5 μm is 0 particles / mm² or more, preferably 1 particle / mm² or more, more preferably 5 particles / mm² or more, and even more preferably 10 particles / mm² or more. Consequently, radiant heat can be efficiently absorbed during the melting of glass containing fine metal particles, reducing energy consumption.

[00121] In glass containing fine metal particles, the number density of particles with a particle diameter greater than 5 μm and 10 μm or less is 0 to 30 particles / mm2. That is, the number density of particles with a particle diameter greater than 5 μm and 10 μm or less is 30 particles / mm2 or less, preferably 20 particles / mm2 or less, more preferably 10 particles / mm2 or less, and also Petition 870250080496, dated 09 / 08 / 2025, p. 99 / 146 26 / 60 more preferably 6 particles / mm2 or less. Consequently, the visible light transmittance of the glass after oxidation treatment can be increased, and high-quality glass can be obtained in a short oxidation treatment time. The numerical density of particles with a particle diameter greater than 5 μm and less than 10 μm is 0 particles / mm2 or more, preferably 0.05 particles / mm2 or more, and most preferably 0.1 particles / mm2 or more. In this way, radiant heat can be efficiently absorbed during the melting of glass containing fine metal particles, reducing energy consumption.

[00122] In glass containing fine metal particles, the number density of particles with a particle diameter greater than 10 μm and 100 μm or less is 0 to 5 particles / mm2. That is, the number density of particles with a particle diameter greater than 10 μm and 100 μm or less is 5 particles / mm2 or less, preferably 3 particles / mm2 or less, more preferably 2 particles / mm2 or less, even more preferably 1 particle / mm2 or less, and particularly preferably 0.5 particles / mm2 or less. Consequently, the visible light transmittance of the glass after oxidation treatment can be increased, and a high-quality glass can be obtained in a short oxidation treatment time.Particles with a particle diameter greater than 10 μm and 100 μm or less may not be contained, and may be 0.1 particles / mm2 or more from the point of view of efficient absorption of radiant heat when melting glass containing fine metal particles and reducing energy consumption.

[00123] In glass containing fine metal particles, the number density of particles with a particle diameter greater than 100 μm and 500 μm or less is 0 to 0.5 particles / mm2. That is, the number density of particles with a particle diameter greater than 100 μm and 500 μm or less is 0.5 particles / mm2 or less, preferably 0.3 Petition 870250080496, dated 08 / 09 / 2025, pp. 100 / 146 27 / 60 particles / mm² or less, more preferably 0.2 particles / mm² or less, and even more preferably 0.1 particles / mm² or less. Consequently, the visible light transmittance of the glass after oxidation treatment can be increased, and high-quality glass can be obtained in a short oxidation treatment time. Particles with a particle diameter greater than 10 μm and 100 μm or less may not be contained, and may be 0.01 particles / mm² or more from the point of view of efficient absorption of radiant heat when melting glass containing fine metal particles and reducing energy consumption.

[00124] Particles with a particle diameter greater than 500 μm are substantially not contained, but in the event they are contained, they can be removed by a metal detector, an optical classifier or similar in the subsequent process.

[00125] In glass containing fine metal particles, the area ratio of fine metal particles in any cross-section of the glass is 0% to 0.15% relative to the total area of ​​any cross-section. The area ratio is preferably 0.13% or less, and more preferably 0.10% or less. Consequently, unnecessary discoloration can be reduced when oxidation treatment is performed. The area ratio is 0% or more, preferably 0.001% or more, more preferably 0.002% or more, and even more preferably 0.003% or more. Consequently, radiant heat is efficiently absorbed during the melting of glass containing fine metal particles, and energy consumption can be reduced.The area ratio is obtained by observing any cross-section of glass containing fine metal particles using an optical microscope and performing image analysis by the method described above, and dividing the total area of ​​the observed fine metal particles by the total area of ​​the observed image's field of view. Petition 870250080496, dated 08 / 09 / 2025, pp. 101 / 146 28 / 60

[00126] One shape of fine metal particles can be, for example, a substantially spherical shape or a substantially perfectly spherical shape.

[00127] In glass containing fine metal particles, an absolute ABS (Tv-Tiioo) value of the difference between a visible light transmittance Tv at a thickness of 2 mm and a transmittance T1100 at a wavelength of 1100 nm at a thickness of 2 mm is preferably 30% or less. In glass containing fine metal particles, since the impurity element is precipitated as a metallic phase, the content of the impurity element remaining in the glassy phase is relatively small. In this case, the absorption derived from the impurity element, as a coloring element, decreases. The transmittance T1100 at a wavelength of 1100 nm is influenced by a magnitude of light absorption derived from Fe2+. That is, a relatively small ABS (Tv-Tiioo) is preferable, meaning that Fe is sufficiently precipitated as a metallic phase in the glass containing fine metal particles, if the Fe-containing raw material contains Fe as an impurity element.ABS (Tv-Tiioo) is more preferably 20% or less, and even more preferably 10% or less. Since a lower ABS (Tv-Tiioo) is preferable, its lower limit is not particularly restrictive.

[00128] Note that in the present description, the visible light transmittance Tv refers to a visible light transmittance Tv value at a thickness of 2 mm, measured based on the JIS R3106:2019 standard. Glass with a thickness greater than 2 mm can be subjected to measurement by polishing up to 2 mm using a general method. Glass with a thickness less than 2 mm can be subjected to measurement by remelting in an inert gas in a general electric furnace, so as not to oxidize the fine metal particles, to obtain a glass with a thickness of 2 mm or more, and then polishing the glass to 2 mm. T1100 means a Petition 870250080496, dated 09 / 08 / 2025, pp. 102 / 146 29 / 60 transmittance at a wavelength of 1100 nm at a thickness of 2 mm.

[00129] In glass containing fine metal particles, the fine metal particles preferably contain at least one element selected from the group consisting of Fe, Si, Co, Cr, Ni, Ti, P, Sb, W, and Nb. In the case where glass containing fine metal particles is obtained by the method described above, the fine metal particles contain at least a portion of the elements contained in the glass-containing feedstock or in the first melt before the reduction treatment. It can be said that the above elements are elements that are readily contained in the fine metal particles due to the elements contained in the glass-containing feedstock or in the first melt before the reduction treatment.

[00130] An average concentration of Fe2O3 in glass containing fine metal particles is preferably from 0.001% to 0.5% in terms of mass percentage based on oxides. Consequently, it can be determined that the content of the impurity element, particularly the content of the element Fe, is relatively small in glass containing fine metal particles. The concentration of Fe2O3 is preferably 0.5% or less, more preferably 0.4% or less, and even more preferably 0.3% or less. On the other hand, the concentration of Fe2O3 is preferably as low as possible. The lower limit is not particularly restricted and may be, for example, 0.001% or more.

[00131] The composition (average composition) of glass containing fine metal particles is not particularly limited; it may, for example, be glass selected from the group consisting of soda-lime glass, aluminosilicate glass, alkali-free glass, and alkali borosilicate glass. Soda-lime glass is preferred from the point of view of higher global production and its large contribution to resource recycling and greenhouse gas reduction. Note that the composition of the glass in the glass-containing feedstock used for the Petition 870250080496, dated 08 / 09 / 2025, pp. 103 / 146 30 / 60 production of glass containing fine metal particles is not particularly limited, and may be the same composition as glass containing fine metal particles, except for the content of the impurity element.

[00132] In the case where the glass containing fine metal particles is soda-lime glass, its composition preferably contains 50% to 85% total SiO2 and AbO3, 5% to 30% total alkaline earth metal oxides (RO) and 0.1% to 25% total alkaline earth metal oxides (R2O), in terms of % by mass on an oxide basis. More preferably, it contains 60% to 80% SiO2, 5% to 20% Na2O, 0% to 15% MgO, 5% to 20% CaO and 0% to 10% Al2O3. In addition, K2O may be contained in an amount less than 5%.

[00133] A preferred composition example is described more specifically below in the case where the glass containing fine metal particles is a soda-lime glass. Note that where the glass composition is described as % or ppm, it means % by mass on an oxide basis or ppm by mass on an oxide basis, unless otherwise specified.

[00134] The total content of SiO2 and Al2O3 is preferably 50% to 85%. The total content of SiO2 and Al2O3 is preferably 50% or more, as the glass can remain stable and weather resistance is improved. The total content of SiO2 and Al2O3 is more preferably 55% or more, and even more preferably 60% or more. The total content of SiO2 and Al2O3 is preferably 85% or less, since the reduction reaction rate and the oxidation reaction rate are increased. The total content of SiO2 and Al2O3 is more preferably 80% or less, and even more preferably 78% or less.

[00135] SiO2 is a major component of soda-lime glass.

[00136] The SiO2 content is preferably between 50% and 80%. The content of Petition 870250080496, dated 09 / 08 / 2025, pp. 104 / 146 31 / 60 SiO2 content is preferably 50% or more, as weather resistance is improved. The SiO2 content is more preferably 60% or more, and even more preferably 65% ​​or more. The SiO2 content is preferably 80% or less, as devitrification is less likely to occur. The SiO2 content is more preferably 75% or less, and even more preferably 73% or less.

[00137] Al2O3 is a component that improves weather resistance.

[00138] The AEO3 content is preferably from 0% to 20%. When Al2O3 is present, weather resistance is improved. The Al2O3 content is preferably 0% or more, more preferably 0.1% or more, even more preferably 0.5% or more, and particularly 1% or more. The Al2O3 content is preferably 15% or less, and even more preferably 10% or less.

[00139] The total content of alkaline earth metal oxides (RO) is preferably from 5% to 30%. The total content of alkaline earth metal oxides (RO) is preferably 5% or more, as the meltability is improved. The total content of alkaline earth metal oxides (RO) is more preferably 7% or more, and even more preferably 10% or more. The total content of alkaline earth metal oxides (RO) is preferably 30% or less, as devitrification is less likely to occur. The total content of alkaline earth metal oxides (RO) is more preferably 25% or less, and even more preferably 20% or less. In this document, the total content of alkaline earth metal oxides (RO) means the total content of MgO, CaO, SrO and BaO.

[00140] MgO is a component that promotes the fusion of vitreous raw materials and improves weather resistance.

[00141] The MgO content is preferably from 0% to 15%. When the Petition 870250080496, dated 09 / 08 / 2025, pp. 105 / 146 32 / 60 When MgO is present, the melting capacity and weather resistance are improved. The MgO content is preferably 0% or more, more preferably 1% or more, even more preferably 2% or more, and particularly preferably 4% or more. The MgO content is preferably 15% or less, as devitrification is less likely to occur. The MgO content is most preferably 10% or less, and even more preferably 5% or less.

[00142] CaO is a component that promotes the fusion of glass raw materials and improves weather resistance.

[00143] The CaO content is preferably 5% to 20%. The CaO content is preferably 5% or more, as the melting capacity and weather resistance are improved. The CaO content is more preferably 6% or more, and even more preferably 7% or more. The CaO content is preferably 20% or less, as devitrification is less likely to occur. The CaO content is more preferably 15% or less, and even more preferably 12% or less.

[00144] The total content of alkali metal oxides (R2O) is preferably from 0.1% to 25%. The total content of alkali metal oxides (R2O) is preferably 0.1% or more, as this improves meltability. The total content of alkali metal oxides (R2O) is more preferably 1% or more, even more preferably 3% or more, and particularly preferably 5% or more. The total content of alkali metal oxides (R2O) is preferably 25% or less, as this improves weather resistance. The total content of alkali metal oxides (R2O) is more preferably 20% or less, and even more preferably 15% or less. In this document, the total content of alkali metal oxides (R2O) means the total content of Li2O, Na2O, and K2O. Petition 870250080496, dated 09 / 08 / 2025, pp. 106 / 146 33 / 60

[00145] Na2U is a component that promotes the fusion of the vitreous raw material.

[00146] The Na2U content is preferably from 0.1% to 25%. The Na2O content is preferably 0.1% or more, as this improves meltability. The Na2O content is more preferably 1% or more, even more preferably 3% or more, and particularly preferably 5% or more. The Na2O content is preferably 25% or less, as this improves weather resistance. The Na2O content is more preferably 20% or less, and even more preferably 15% or less.

[00147] K2O is a component that promotes the fusion of vitreous raw material.

[00148] K2O is not essential, but it can be contained in an amount less than 5%. That is, the K2O content can be 0% or more and less than 5%. When K2O is present, the melting capacity is improved. In the case of K2O being present, its content is preferably 0.01% or more, and more preferably 0.5% or more. The K2O content is preferably less than 5%, since weather resistance is improved. The K2O content is more preferably 3% or less, and even more preferably 2% or less.

[00149] The composition (average composition) of the glass obtained by the present production method can be measured by X-ray fluorescence composition analysis. In addition, components with a content of less than 1% and light element components, such as Li2O and B2O3, may be difficult to quantify by X-ray fluorescence analysis, and composition analysis can be performed using an electron probe microanalyzer (EPMA), ICP optical emission spectrometry, or ICP mass spectrometry.

[00150] The shape of glass containing fine metal particles is not particularly limited, and it can have various shapes, such as Petition 870250080496, dated 08 / 09 / 2025, pages 107 / 146 34 / 60 block, crushed piece, container, fiber, bead and plate. In the case of glass in plate form, it may be in the form of a flat plate or formed or bent to have a curved surface. In the case of glass in plate form, the thickness is not particularly limited, preferably, for example, from 0.1 mm to 20 mm. In the case of glass containing fine metal particles being used as raw material, from the point of view of ease of handling, a shape that occupies 80% or more by mass in the glass containing fine metal particles is preferably a crushed piece or a spherical shape with a size of 1 mm to 100 mm, and more preferably a crushed piece or a spherical shape with a size of 3 mm to 50 mm. Glass in the form of a crushed piece is crushed by a general mechanical crushing method, such as crushing with water or a roller crusher, and is generally called cullet.Spherical glass can be prepared using wind energy, as a gas atomization method. The size and proportion of the glass can be assessed by passing it through a sieve with a predetermined opening and measuring the mass with a scale. Note that a tiny amount of glass generated by collision or similar between glasses during transport is not included.

[00151] (Oxidation Treatment)

[00152] When glass containing the above fine metal particles is subjected to an oxidation treatment, high-quality glass with few production defects and unnecessary discoloration reduction can be obtained.

[00153] That is, a glass is preferably obtained by subjecting a fusion (hereinafter also referred to as a third fusion) obtained by melting glass containing fine metal particles to an oxidation treatment.

[00154] A method of oxidation treatment is not particularly Petition 870250080496, dated 08 / 09 / 2025, pages 108 / 146 35 / 60 limited, and examples include a method using an oxidizing gas and a method adding an oxidizing agent. The method using an oxidizing gas is preferable from the point of view that the composition of the molten mass is less likely to change.

[00155] Specific examples of oxidizing gas include a gas containing O2, a gas containing H2O, and a gas containing CO2. From the point of view of oxidation efficiency and availability, a gas containing O2 is preferred as the oxidizing gas. Examples of O2-containing gas include air (the atmosphere), an O2 gas, and a mixed gas of an O2 gas and an inert gas, and air (the atmosphere) and an O2 gas are preferred from the point of view of availability.

[00156] Specific examples of the method of carrying out the oxidation treatment using an oxidizing gas include a third melt bubbling method using the oxidizing gas. If necessary, an inert gas can be mixed with the oxidizing gas. Examples of inert gas include nitrogen gas, argon gas, and helium gas.

[00157] Specific examples of oxidizing agents include nitrates, such as sodium nitrate, sulfates, such as sodium sulfate, cerium oxide, antimony(V) oxide, and tin(IV) oxide. From the point of view of oxidation efficiency, availability, and environmental impact, nitrates, cerium oxide, and tin(IV) oxide are preferred.

[00158] Specific examples of the method of carrying out the oxidation treatment using an oxidizing agent include a method of adding an oxidizing agent to the third melt. The oxidizing agent is preferably in powder form for an efficient reaction. The addition method is preferably a powder injection method for an efficient reaction.

[00159] The treatment temperature in the oxidation treatment is preferably from 1,300°C to 1,800°C. That is, the treatment temperature is preferably 1,300°C or higher, plus Petition 870250080496, dated 08 / 09 / 2025, pages 109 / 146 36 / 60 preferably at 1,400°C or higher, and even more preferably at 1,450°C or higher, from the point of view of obtaining a sufficient oxidation reaction rate. On the other hand, the treatment temperature is preferably 1,800°C or lower, more preferably 1,700°C or lower, and even more preferably 1,650°C or lower, from the point of view of preventing refractory erosion and reducing energy consumption.

[00160] The oxidation treatment time is not particularly limited and, in the case of bubbling with oxidizing gas, for example, 1 minute to 24 hours is preferred. That is, the treatment time is preferably 1 minute or more, more preferably 5 minutes or more, and even more preferably 15 minutes or more, from the point of view of sufficient removal of fine metal particles. On the other hand, the treatment time is preferably 24 hours or less, more preferably 12 hours or less, and even more preferably 8 hours or less, from the point of view of preventing refractory erosion and reducing energy consumption.

[00161] With oxidation treatment, a high-quality glass can be produced from glass containing fine metal particles. Note that after oxidation treatment, a known glass composition adjustment step, forming step, annealing step, or similar may be performed.

[00162] (Glass)

[00163] When a molten material obtained by melting glass containing fine metallic particles is subjected to a bubbling oxidation treatment in an atmosphere at 1,500°C for 30 minutes to obtain glass, the resulting glass preferably does not contain fine metallic particles with a particle diameter equal to or greater than 1 μm. In this case, "does not contain fine metallic particles with a particle diameter equal to or greater than 1 μm" means that metallic particles Petition 870250080496, dated 08 / 09 / 2025, pp. 110 / 146 37 / 60 fine particles with a particle diameter equal to or greater than 1 μm are not observed when any cross-section of glass containing fine metallic particles is observed using an optical microscope and subjected to image analysis by the method described above.

[00164] When a molten mass obtained by melting glass containing fine metal particles is subjected to a bubbling oxidation treatment using an atmosphere at 1,500°C for 120 minutes to obtain a glass, the resulting glass preferably has a visible light transmittance Tv of 50% or more. Since the diameter distribution of the fine metal particles contained in the glass containing fine metal particles, according to the embodiment of the present invention, is within a specific range, the discoloration and defects of the glass after the oxidation treatment can be reduced, and a glass with a relatively high visible light transmittance Tv can be obtained. That is, the Tv is preferably 50% or more, more preferably 70% or more, even more preferably 80% or more, and particularly preferably 87.5% or more. The Tv is preferably as high as possible and can be, for example, 92% or less.That is, Tv is preferably in the range of 50% to 92%. As described above, the visible light transmittance Tv refers to a value of visible light transmittance Tv at a thickness of 2 mm measured based on the JIS R3106:2019 standard.

[00165] The difference Δ^ between the visible light transmittance Tv of the primary glass contained in the glass-containing feedstock used in the production of glass containing fine metal particles and the visible light transmittance Tv of the glass obtained, when the glass is obtained by subjecting a molten mass obtained by melting glass containing fine metal particles to a bubbling oxidation treatment using an atmosphere at 1,500°C for 120 minutes, is preferably from 0% to 70%. If the glass in the glass-containing feedstock contains a component Petition 870250080496, dated 08 / 09 / 2025, pp. 111 / 146 38 / 60 dye, the visible light transmittance Tv of the same tends to decrease. As the glass obtained by subjecting glass containing fine metal particles to an oxidation treatment exhibits relatively high transparency due to the removal of impurity elements, including the dye component and the like, ΔTν tends to increase. That is, ΔTν is preferably 0% or more, more preferably 1.0% or more, and even more preferably 2.0% or more. ΔTν is preferably as high as possible, and may be, for example, 70% or less. Note that the main glass contained in the glass-containing feedstock refers to glass excluding the external foreign substance contained in the glass-containing feedstock. Furthermore, Δ^ means (the visible light transmittance Tv of the glass obtained after the oxidation treatment) - (the visible light transmittance Tv of the main glass contained in the glass-containing feedstock).

[00166] When a melt obtained by melting glass containing fine metal particles is subjected to a bubbling oxidation treatment using an atmosphere at 1,500°C for 120 minutes to obtain a glass, the following are preferably satisfied.

[00167] That is, the NWF post / before ratio of the total content of a network-forming oxide in the glass obtained to the total content of the network-forming oxide in the glass containing fine metallic particles is preferably from 0.40 to 1.50 in terms of % by mass based on oxides. That is, the NWF post / before is preferably 0.40 or more, more preferably 0.50 or more, and even more preferably 0.60 or more. On the other hand, the NWF post / before is preferably 1.50 or less, more preferably 1.30 or less, and even more preferably 1.20 or less. Furthermore, the NWM post / before ratio of the total content of a network-modifying oxide in the glass obtained to the total content of the network-modifying oxide in the glass containing fine metallic particles is preferably from 0.60 to 2.00. That is, the NWMap post / before is preferably 0.60 Petition 870250080496, dated 08 / 09 / 2025, pp. 112 / 146 39 / 60 or more, more preferably 0.70 or more, and even more preferably 0.80 or more. On the other hand, the NWMapós / antes is preferably 2.00 or less, more preferably 1.60 or less, and even more preferably 1.40 or less.

[00168] Both the network-forming oxide and the network-modifying oxide constitute the main components of the glass. Therefore, the NWF after / before and the NWM after / before, respectively, within the above ranges, means that the variation between the main component of the glass in the glass containing fine metal particles and the main component of the glass obtained after the oxidation treatment is small. This is preferable from the point of view that the recycling of the glass raw material can be carried out while maintaining the useful components.

[00169] In the present description, the total content of network-forming oxide means the total content of SiO2, AbO3, B2O3 and P2O5. The total content of network-modifying oxide means the total content of MgO, CaO, SrO, BaO, Li2O, Na2O and K2O.

[00170] (Application)

[00171] According to the present invention, it is possible to provide glass containing fine metallic particles from which high-quality glass with few manufacturing defects and reduced discoloration can be obtained during an oxidation treatment. That is, the glass containing fine metallic particles, according to the embodiment of the present invention, is suitably used as a raw material for the production of high-quality glass with few manufacturing defects and reduced discoloration. Furthermore, since the glass containing fine metallic particles, according to the embodiment of the present invention, is preferably derived from a glass-containing raw material, including waste glass or defective glass, the waste glass or defective glass can be suitably recycled by producing glass using the glass containing fine metallic particles as raw material. Petition 870250080496, dated 08 / 09 / 2025, pages 113 / 146 40 / 60 A type of glass obtained by subjecting glass containing fine metallic particles to an oxidation treatment can be used in various applications and is preferably used as, for example, glass for construction materials, automotive glass, container glass, glass wool, glass beads, and the like.

[00172] EXAMPLES

[00173] The present invention is described in detail herewith reference to the Examples, but the present invention is not limited to them. Examples 1 to 8 and 12 to 19 are Practical Examples, and Examples 9 to 11 are Comparative Examples.

[00174] (Raw material containing glass)

[00175] Glasses A to L were prepared with compositions in % by mass or ppm by mass based on oxides, as shown in Table 1. Stainless steel (SUS304) and metallic aluminum (Al) were prepared as external foreign substances. Glasses A to L and the external foreign substances were used in the combinations shown in Tables 2 and 3 to prepare the glass-containing feedstocks in Examples 1 to 19. If the type of external foreign substance is described as none, it means that each of the glasses A to L is used as a glass-containing feedstock.

[00176] (Example 1)

[00177] Glass A, as a glass-containing raw material, was loaded into an alumina crucible and melted by raising the temperature to 1500°C in an electric furnace under a nitrogen atmosphere to obtain a first melt. Using granulated carbon (C) with the size shown in Table 2 as a reducing agent, a reduction treatment was carried out by passing the first melt through the reducing agent previously placed in the alumina crucible, in order to obtain a mass ratio of 0.4 and a filling rate of approximately 60% by volume, thus precipitating a metallic phase. In the reduction treatment, Petition 870250080496, dated 08 / 09 / 2025, pages 114 / 146 41 / 60 The treatment temperature was 1,500°C and the treatment time was 120 minutes. With this treatment, the metallic phase was precipitated on the surface of the reducing agent and the metallic phase was captured on the surface of the reducing agent. At the same time, the mixture was left to stand to deposit relatively large fine metallic particles. Then, the crucible was annealed and, to separate the deposited fine metal particles, a lower surface was physically cut at 3 mm to 5 mm to separate at least part of the metallic phase, thus obtaining a glass containing fine metal particles in Example 1 as a cooled substance from a second melting.

[00178] Next, the glass containing fine metal particles was loaded into the alumina crucible and melted by raising the temperature to 1,500°C in an electric furnace to obtain a third melt. The oxidation treatment was carried out by blowing air into the third melt. At this point, the third melt was subjected to an oxidation treatment under two different conditions to obtain two types of glass after the oxidation treatment. That is, as an oxidation treatment (a), an oxidation treatment was carried out at a treatment temperature of 1,500°C for a treatment time of 30 minutes, and then the third melt was annealed to obtain a glass (a) after the oxidation treatment. Furthermore, as an oxidation treatment (b), an oxidation treatment was carried out at a treatment temperature of 1,500°C for a treatment time of 120 minutes, and then the third melt was annealed to obtain a glass (b) after the oxidation treatment.

[00179] (Examples 2, 5 to 8 and 12 to 19)

[00180] A glass containing fine metal particles in each example was obtained in the same way as in Example 1, except that the conditions were altered as shown in Tables 2 and 3. After that, the glass containing fine metal particles in each example was Petition 870250080496, dated 08 / 09 / 2025, pages 115 / 146 42 / 60 melted in the same manner as in Example 1, and the third melt was subjected to two types of oxidation treatments to obtain glass (a) and glass (b) after the oxidation treatment.

[00181] (Example 3)

[00182] Glass A was used as the raw material containing glass, carbon (C) was mixed in as a reducing agent at a mass ratio of 0.03 relative to the mass of glass A, the mixture was loaded into an alumina crucible, the temperature was raised to 1500°C in an electric furnace under a nitrogen atmosphere, and then N2 gas was bubbled from the top using an alumina tube to obtain a first melt, and a reduction treatment was carried out simultaneously to precipitate a metallic phase. The treatment time in the reduction treatment was 120 minutes. Then, the mixture was left to stand for 120 minutes to deposit relatively large fine metallic particles.Next, the crucible was annealed and, to separate the deposited fine metallic particles, a lower surface of the crucible was physically cut into 3 mm to 5 mm sections to separate at least part of the metallic phase, thus obtaining a glass containing fine metallic particles in Example 3 as a cooled substance from a second melt. Then, the glass containing fine metal particles in Example 3 was melted in the same way as in Example 1, and the third melt was subjected to two types of oxidation treatments to obtain glass (a) and glass (b) after the oxidation treatment.

[00183] (Example 4)

[00184] A glass containing fine metallic particles in Example 4 was obtained in the same way as in Example 3, except that glass A was used as a raw material containing glass, carbon (C) and silicon (Si) were mixed as reducing agents in a mass ratio of 0.02 and 0.01, respectively, relative to the mass of glass A, and the Petition 870250080496, dated 08 / 09 / 2025, pages 116 / 146 43 / 60 conditions were altered as shown in Table 2. Then, the glass containing fine metallic particles in Example 4 was subjected to an oxidation treatment to obtain a glass after the oxidation treatment. Then, the glass containing fine metallic particles in Example 4 was melted in the same way as in Example 1, and the third melt was subjected to two types of oxidation treatments to obtain a glass (a) and a glass (b) after the oxidation treatment.

[00185] (Examples 9 to 11)

[00186] A glass-containing feedstock, containing crushed glass pieces prepared on a 5.6 mm sieve, as shown in Table 2, and activated carbon with a size of 74 μm or less as a reducing agent, was mixed at a mass ratio of 0.03 to the mass of the glass. The mixture was loaded into an alumina crucible, the temperature was raised to 1500°C in an electric furnace under a nitrogen atmosphere to obtain a first melt, and a reduction treatment was performed to precipitate a metallic phase. The mixture was then left to stand for 120 minutes, the crucible was annealed, and to separate the precipitated fine metal particles, the bottom surface of the crucible was physically cut 3 mm to 5 mm apart to separate at least part of the metallic phase, thus obtaining a glass containing fine metal particles in each of Examples 9 to 11 as a cooled substance from a second melt.Next, the glass containing fine metal particles in each of Examples 9 to 11 was melted in the same manner as in Example 1, and the third melt was subjected to two types of oxidation treatments to obtain a glass (a) and a glass (b) after the oxidation treatment.

[00187] (Evaluation)

[00188] The glass containing fine metal particles obtained in Examples 1 to 19 and the glasses after oxidation treatment, obtained by subjecting them to an oxidation treatment, were evaluated by the following Petition 870250080496, dated 08 / 09 / 2025, pages 117 / 146 44 / 60 methods. The results are presented in Tables 2 and 3.

[00189] (Number density and area ratio of fine metallic particles)

[00190] Observation was performed by epiillumination using a digital microscope (model number VHX-5000, manufactured by KEYENCE Corporation). After polishing any cross-section, images were obtained at 16 positions with magnifications of 200x and 1000x, respectively, and image analysis was performed using ImageJ image analysis software. First, the image was converted to 8 bits, and then a threshold value serving as a boundary between a particle and a glass was defined using a threshold function during image verification. Next, the area of ​​each particle included in the image was calculated using the Analyze Particles function, and the particle diameter distribution of each image was obtained. The number density for each particle diameter of the fine metal particles was obtained by dividing the number of the specific particle diameter observed by the total area of ​​the field of view of the observed image.Furthermore, the area ratio of fine metal particles was obtained by dividing the total area of ​​the observed fine metal particles by the total area of ​​the observed image field of view. From the point of view of measurement precision, only particles with a particle diameter greater than 5 μm were counted at a magnification of 200 times, and only particles with a particle diameter greater than 1 μm to 5 μm were counted at a magnification of 1,000 times. Observation and analysis were performed on the glass containing fine metal particles and on the glass (a) after oxidation treatment in each example. In cases where the glass (a) after oxidation treatment contained practically no fine metal particles with a particle diameter equal to or greater than 1 μm, the presence or absence of fine metal particles in the glass after oxidation treatment (a) is shown in the Tables. Petition 870250080496, dated 08 / 09 / 2025, pages 118 / 146 45 / 60 and 3 was recorded as none.

[00191] As an example of the captured image and the image after processing, Figure 1A shows an image obtained by capturing any cross-section of the glass containing fine metal particles from Example 4 at a magnification of 200 times. Figure 1B shows an image obtained by image processing in Figure 1A. Figure 2A shows an image of any cross-section of the glass containing fine metal particles from Example 4, captured at a magnification of 1,000 times. Figure 2B shows an image obtained by image processing in Figure 2A.

[00192] (Main component of fine metallic particles)

[00193] The main component of fine metal particles was measured by scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX).

[00194] (Tv, ABS (Tv-Thoo) and ΔΤν)

[00195] The visible light transmittance Tv was measured using a spectrophotometer (Model No. U—4100, manufactured by Hitachi High-Tech Science Corporation) based on the JIS R3106:2019 standard. In addition, the transmittance T 1100 was measured at a wavelength of 1100 nm. The measurement was performed on glasses A to L, on the glass containing fine metal particles in each example, and on glass (b) obtained through oxidation treatment in each example, using a sample with a thickness of 2 mm for the measurement.

[00196] (Composition and Concentration of Fe2O3)

[00197] For the glass containing fine metal particles and the glass (b) obtained by carrying out the oxidation treatment in each example, and glasses A to L, the composition and concentration of the impurity element in terms of % by mass or ppm by mass were measured as follows. The concentrations of the main components (SiO2, Al2O3, P2O5, RO and R2O in the Examples) and Fe2O3 in the glass were measured. Petition 870250080496, dated 09 / 08 / 2025, pp. 119 / 146 46 / 60 by X-ray fluorescence analysis. However, in the reduction treatment or oxidation treatment, in the case where an alumina crucible or alumina tube was used, AbOs may be unintentionally dissolved in the glass to increase the Al2O3 concentration and, therefore, the Al2O3 concentration in the glass after treatment was calculated using the same value as the Al2O3 concentration contained in the glass-containing raw material. Note that, within the scope of the present invention, there is no factor affecting the AbOs concentration in the glass except for the fact that the alumina crucible or alumina tube is dissolved in the glass. Note that the concentrations of other trace components contained in glasses A to L were measured by laser ablation-ICP mass spectrometry (LA-ICP-MS) (laser system: model NWR213, manufactured by Japan Laser Corporation; ICP mass spectrometer: model ELEMENT II, ​​manufactured by Thermo Fisher Scientific KK).

[00198] [Table 1] Unit Glass A Glass B Glass C Glass D Glass E Glass F SiO2+Al2O3 % by weight 72 74 72 74 73 74 Total RO value % by weight 13 12 13 12 13 13 Total R2O value % by weight 14 13 14 13 12 12 P2O5 % by weight - - - - - - Fe2O3 % by weight 1.5 0.5 1.0 0.5 1.8 0.23 CoO ppm by weight - - 230 - 100 140 Cr2O3 ppm by weight - - 12 - 190 - NiO ppm by weight - - - - - 880 MnO2 ppm by weight - - - - - - Petition 870250080496, dated 08 / 09 / 2025, pages 120 / 146 47 / 60 Sb2O3 ppm by weight - - - 1600 - - ZnO ppm by weight - - - - - - PbO ppm by weight - - - - - - CuO ppm by weight - - - - - - Visible light transmittance Tv at 2 mm thickness % 77.3 86.4 40.5 87.1 56.4 51.6 00199] [Table 1] (continued) Unit Glass G Glass H Glass I Glass J Glass K Glass L SiO2+Al2O3 % by weight 73 76 76 82 84 83 Total RO value % by weight 13 12 11 4 2 - Total R2O value % by weight 14 12 12 13 11 10 P2O5 % by weight - - - - - 5 Fe2O3 % by weight 0.01 0.5 0.1 0.6 0.6 0.6 CoO ppm by weight - - 200 - - - Cr2O3 ppm by weight - 900 1100 - - - NiO ppm by weight - - - - - - MnO2 ppm by weight - - 400 - - - Sb2O3 ppm by weight 1300 - - - - - ZnO ppm by weight - 100 - - - - PbO ppm per - 200 - - - - Petition 870250080496, dated 08 / 09 / 2025, pages 121 / 146 48 / 60 CuO weight ppm by weight - - 200 - - - Visible light transmittance Tv at 2 mm thickness % 91.7 44.9 50.2 85.8 83.7 81.8 00200] [Table 2] Unit Example 1 Example 2 Example 3 Example 4 Raw material containing glass Glass type - ABAA Type of external foreign substance - No No No No Amount of external foreign substance ppm by weight Reduction treatment temperature °C 1500 1500 1500 1500 Type of reducing agent - CCCC, Si Size of reducing agent millimeters 3 to 10 3 to 10 < 0.074 < 0.074 Glass containing fine metal particles Main component of fine metal particles - Fe-Si Fe-Si Fe-Si Fe-Si Number density of fine metal particles More than 1 μm and 5 μm or less Particles / mm2 69.7 20.8 38.8 35.9 More than 5 μm and 10 μm or less Particles / mm2 0.1 0.3 14.9 7.0 More than 10 μm and 100 μm or less Particles / mm2 0.0 0.0 1.0 1.2 Petition 870250080496, dated 09 / 08 / 2025, pp. 122 / 146 49 / 60 More than 100 μm and 500 μm or less Particles / mm2 0.0 0.0 0.0 0.0 More than 500 μm Particles / mm2 0.0 0.0 0.0 0.0 Fine metal particle area ratio % 0.012 0.003 0.072 0.083 ABS (Tv-Tioo) % 2.2 0.2 10.4 6.3 Fe2O3 (Average) % by weight 0.12 0.07 0.19 0.19 Glass after oxidation treatment NWF after % by weight 75.9 75.6 75.9 77.5 NWF after / before - 1.05 1.02 1.05 1.08 NWM after % by weight 23.7 24.2 23.9 22.4 NWM after / before - 0.88 0.97 0.89 0.83 Presence or absence of fine metal particles in the glass after oxidation treatment (a) - No No No No Visible light transmittance Tv of the glass after oxidation treatment (b) % 89.2 91.2 88.3 88.6 ΔTν % 11.9 4.8 11.0 11.3 00201] [Table 2] (continued) Unit Example 5 Example 6 Example 7 Example 8 Raw material containing glass Glass type - CDBB Petition 870250080496, dated 08 / 09 / 2025, pages 123 / 146 50 / 60 Type of external foreign substance - No No SUS304 Al Amount of external foreign substance ppm by weight 3000 3000 Reduction treatment temperature °C 1500 1500 1500 1500 Type of reducing agent - CCCC Size of reducing agent millimeters 3 to 10 3 to 10 3 to 10 3 to 10 Glass containing fine metal particles Main component of fine metal particles - Fe-Si-Co Fe-Si-Sb Fe-Si-Cr Fe-Si Number density of fine metal particles More than 1 μm and 5 μm or less Particles / mm2 291.4 230.1 205.0 81.3 More than 5 μm and 10 μm or less Particles / mm2 2.4 2.2 0.6 1.1 More than 10 μm and 100 μm or less Particles / mm2 0.02 0.1 0.0 0.03 More than 100 μm and 500 μm or less Particles / mm2 0.0 0.0 0.0 0.0 More than 500 μm Particles / mm2 0.0 0.0 0.0 0.0 Fine metal particle area ratio % 0.078 0.062 0.042 0.019 ABS (Tv-Tioo) % 1.3 0.8 1.7 1.4 Fe2O3 (Average) % by weight 0.16 0.07 0.10 0.12 Glass after oxidation treatment NWF after % by weight 74.0 74.9 73.6 74.0 Petition 870250080496, dated 08 / 09 / 2025, pages 124 / 146 51 / 60 NWFafter / before - 1.03 1.01 0.99 1.00 NWMafter % by weight 25.1 24.9 26.2 25.7 NWMafter / before - 0.93 1.00 1.05 1.03 Presence or absence of fine metal particles in the glass after the oxidation treatment (a) - No No No No Visible light transmittance Tv of the glass after oxidation treatment (b) % 89.8 89.5 87.9 88.6 ΔTν % 49.3 2.4 1.5 2.2 00202] [Table 2] (continued) Unit Example 9 Example 10 Example 11 Raw material containing glass Glass type - BBC Type of external foreign substance - No SUS304 No Amount of external foreign substance ppm by weight 3000 Reduction treatment temperature °C 1500 1500 1500 Type of reducing agent - CCC Size of reducing agent millimeters < 0.074 < 0.074 < 0.074 Glass containing fine metal particles Main component of fine metal particles - Fe-Si Fe-Si-Cr-Ni Fe-Si-Co Number density of fine metal particles More than 1 μm and 5 μm or less Particles / mm2 506.3 336.2 204.0 More than 5 μm and 10 μm or less Particles / mm2 2.3 3.4 8.0 Petition 870250080496, dated 09 / 08 / 2025, pp. 125 / 146 52 / 60 More than 10 μm and 100 μm or less Particles / mm2 0.05 0.07 1.4 More than 100 μm and 500 μm or less Particles / mm2 0.0 0.0005 0.0 More than 500 μm Particles / mm2 0.0 0.0015 0.0 Fine metal particle area ratio % 0.171 0.249 0.200 ABS (Tv-Tioo) % 0.8 0.2 3.0 Fe2O3 (Average) % by weight 0.45 0.47 0.73 Glass after oxidation treatment NWF after % by weight 75.7 75.2 73.9 NWF after / before - 1.02 1.02 1.03 NWM after % by weight 23.9 24.3 24.5 NWM after / before - 0.96 0.97 0.91 Presence or absence of fine metal particles in the glass after the oxidation treatment (a) - No Yes No Visible light transmittance Tv of the glass after oxidation treatment (b) % 87.0 84.9 65.1 ΔTν % 0.6 -1.5 24.6 00203] [Table 3] Unit Example 12 Example 13 Example 14 Raw material containing glass Glass type - EFG Type of external foreign substance - No No No Quantity of external foreign substance ppm by weight Petition 870250080496, dated 09 / 08 / 2025, pp. 126 / 146 53 / 60 Temperature of the reduction treatment °C 1550 1550 1550 Type of reducing agent - CCC Size of reducing agent millimeters 3 to 10 3 to 10 3 to 10 Glass containing fine metal particles Main component of fine metal particles - Fe-Si-Co-Cr Fe-Si-Co-Ni Fe-Si-Sb Numerical density of fine metal particles More than 1 μm and 5 μm or less Particles / mm2 104.0 64.8 85.2 More than 5 μm and 10 μm or less Particles / mm2 0.0 0.1 0.0 More than 10 μm and 100 μm or less Particles / mm2 0.0 0.0 0.0 More than 100 μm and 500 μm or less Particles / mm2 0.0 0.0 0.0 More than 500 μm Particles / mm2 0.0 0.0 0.0 Fine metal particle area ratio % 0.012 0.008 0.010 ABS (Tv-Tioo) % 1.1 0.0 0.7 Fe2O3 (Average) % by weight 0.01 0.01 0.01 Glass after oxidation treatment NWF after % by weight 74.9 75.1 74.9 NWF after / before - 1.03 1.01 1.03 NWM after % by weight 25.1 24.9 25.1 NWM after / before - 1.00 1.00 0.93 Presence or absence of fine metal particles in the glass after processing - No No No, Petition 870250080496, dated 08 / 09 / 2025, pages 127 / 146 54 / 60 (a) Visible light transmittance Tv of the glass after oxidation treatment (b) % 91.2 91.3 91.8 ΔTν % 34.8 39.7 0.1 00204] [Table 3] (continued) Example Unit 15 Example 16 Raw material containing glass Glass type - HI Type of external foreign substance - No No Amount of external foreign substance ppm by weight Reduction treatment temperature °C 1550 1550 Type of reducing agent - CC Size of reducing agent millimeters 3 to 10 3 to 10 Glass containing fine metal particles Main component of fine metal particles - Fe-Si-Cr-Zn-Pb Fe-Si-Co-Cr-Mn-Cu Numerical density of fine metal particles More than 1 μm and 5 μm or less Particles / mm2 204.2 159.8 More than 5 μm and 10 μm or less Particles / mm2 0.1 0.0 More than 10 μm and 100 μm or less Particles / mm2 0.0 0.0 More than 100 μm and 500 μm or less Particles / mm2 0.0 0.0 More than 500 μm Particles / mm2 0.0 0.0 Fine metal particle area ratio % 0.027 0.020 ABS (Tv-Tioo) % 0.6 0.9 Petition 870250080496, dated 09 / 08 / 2025, pp. 128 / 146 55 / 60 Fe2O3 (Average) % by weight 0.03 0.02 Glass after oxidation treatment NWF after % by weight 75.1 74.7 NWF after / before - 0.99 0.98 NWM after % by weight 24.9 25.2 NWM after / before - 1.04 1.10 Presence or absence of fine metal particles in the glass after oxidation treatment (a) - No No Visible light transmittance Tv of the glass after oxidation treatment (b) % 88.5 87.2 ΔTν % 43.6 37.0 00205] [Table 3] (continued) Unit Example 17 Example 18 Example 19 Raw material containing glass Glass type - JKL Type of external foreign substance - No No No Amount of external foreign substance ppm by weight Reduction treatment temperature °C 1500 1500 1500 Type of reducing agent - CCC Size of reducing agent millimeters 3 to 10 3 to 10 3 to 10 Glass containing fine metal particles Main component of fine metal particles - Fe-Si Fe-Si Fe-Si Petition 870250080496, dated 08 / 09 / 2025, pages 129 / 146 56 / 60 Number density of fine metal particles More than 1 pm and 5 pm or less Particles / mm2 435.2 153.7 293.5 More than 5 pm and 10 pm or less Particles / mm2 3.7 0.1 0.0 More than 10 pm and 100 pm or less Particles / mm2 0.0 0.0 0.0 More than 100 pm and 500 pm or less Particles / mm2 0.0 0.0 0.0 More than 500 pm Particles / mm2 0.0 0.0 0.0 Area ratio of fine metal particles % 0.085 0.015 0.041 ABS (Tv-Tioo) % 0.2 0.0 0.0 Fe2O3 (Average) % by weight 0.39 0.20 0.41 Glass after oxidation treatment NWF after % by weight 84.0 84.1 87.3 NWF after / before - 1.02 1.00 0.99 NWM after % by weight 15.3 13.5 10.2 NWM after / before - 0.90 1.04 1.02 Presence or absence of fine metal particles in the glass after oxidation treatment (a) - No No No Visible light transmittance Tv of the glass after oxidation treatment (b) % 86.5 89.5 88.9 ΔTν % 0.7 5.8 7.1

[00206] As shown in Tables 2 and 3, the glasses obtained by subjecting the glasses containing fine metal particles from Examples 1 to 8 and 12 to 19, which are Working Examples, to an oxidation treatment, contain practically no fine metal particles with a particle diameter of 1 μm or more, and are each high-quality glasses. Petition 870250080496, dated 08 / 09 / 2025, pages 130 / 146 57 / 60 quality with a relatively high visible light transmittance Tv, few defects, and reduced unnecessary coloration. On the other hand, in glasses obtained by subjecting glasses containing fine metal particles from Examples 9 to 11 to an oxidation treatment, the fine metal particles remain, or the concentration of the coloring component, such as Fe2O3, in the glass is not sufficiently reduced relative to the raw material containing the glass, and the visible light transmittance is relatively low, resulting in poor quality.

[00207] As described above, the following subjects are described in this description.1. A glass containing fine metal particles, which is a glass containing fine metal particles, in which the number density of the fine metal particles for each particle diameter in any cross-section of the glass is in the following ranges, and the area ratio of the fine metal particles in any cross-section of the glass is from 0% to 0.15% relative to the total area of ​​any cross-section,

[00208] Particle diameter greater than 1 μm and 5 μm or less: 0 to 1,000 particles / mm2,

[00209] Particle diameter of more than 5 μm and 10 μm or less: 0 to 30 particles / mm2,

[00210] Particle diameter of more than 10 μm and 100 μm or less: 0 to 5 particles / mm2,

[00211] Particle diameter of more than 100 μm and 500 μm or less: 0 to 0.5 particles / mm2,

[00212] particle diameter of more than 500 μm: substantially not contained.

[00213] 2. Glass containing fine metal particles, according to item 1 above, in which an absolute ABS (Tv-Tiioo) value of a difference between a visible light transmittance Tv at a thickness of 2 Petition 870250080496, dated 09 / 08 / 2025, pp. 131 / 146 58 / 60 mm and a T1100 transmittance at a wavelength of 1100 nm in a thickness of 2 mm is 30% or less.

[00214] 3. Glass containing fine metal particles, according to item 1 or 2 above, in which the fine metal particles contain at least one element selected from the group consisting of Fe, Si, Co, Cr, Ni, Ti, P, Sb, W and Nb.

[00215] 4. Glass containing fine metal particles, according to any of items 1 to 3 above, wherein when a melt obtained by melting glass containing fine metal particles is subjected to a bubbling oxidation treatment using an atmosphere at 1,500°C for 120 minutes to obtain a glass, the glass obtained has a visible light transmittance Tv of 50% or more at a thickness of 2 mm.

[00216] 5. Glass containing fine metal particles, according to any of items 1 to 4 above, wherein, in terms of % by mass on an oxide basis, when a melt obtained by melting glass containing fine metal particles is subjected to a bubbling oxidation treatment using an atmosphere at 1,500°C for 120 minutes to obtain a glass, an NWF ratio after / before is 0.40 to 1.50, the NWF ratio after / before being a ratio of the total content of a network-forming oxide in the glass obtained to a total content of the network-forming oxide in the glass containing fine metal particles, and an NWM ratio after / before is 0.60 to 2.00, the NWM ratio after / before being a ratio of the total content of a network-modifying oxide in the glass obtained to a total content of the network-modifying oxide in the glass containing fine metal particles.

[00217] 6. Glass containing fine metal particles, according to any of items 1 to 5 above, wherein an average concentration of Fe2O3 in the glass containing fine metal particles is from 0.001% to 0.5% Petition 870250080496, dated 08 / 09 / 2025, pages 132 / 146 59 / 60 in terms of % by mass based on oxides.

[00218] 7. Glass containing fine metal particles, according to any of items 1 to 6 above, wherein when a melt obtained by melting glass containing fine metal particles is subjected to a bubbling oxidation treatment using an atmosphere at 1,500°C for 30 minutes to obtain a glass, the glass obtained substantially does not contain fine metal particles with a particle diameter of 1 μm or more.

[00219] 8. Glass containing fine metal particles, according to any of items 1 to 7 above, wherein a shape that occupies 80% or more on a mass basis is a crushed chunk shape or a spherical shape with a size of 1 mm to 100 mm.

[00220] 9. A method for producing glass containing fine metal particles, which is a method for producing glass containing fine metal particles, according to any of items 1 to 8 above, the method including: To obtain a fusion by melting a glass-containing raw material; and to subject the fusion to a reduction treatment.

[00221] 10. The method for producing a glass containing fine metallic particles, according to item 9 above, in which in the reduction treatment, at least one selected from the group consisting of a simple substance and a compound containing at least one element selected from the group consisting of C, Al, Si, Ca, Ti and H, and a mixture containing the simple substance and the compound is used as a reducing agent.

[00222] 11. The method for producing a glass containing fine metallic particles, according to item 10 above, in which the reducing agent contains at least one selected from the group consisting of a simple substance and a compound containing at least one Petition 870250080496, dated 08 / 09 / 2025, pages 133 / 146 60 / 60 element selected from the group consisting of C, Si and H, and a mixture containing the simple substance and the compound.

[00223] 12. The method for producing a glass containing fine metallic particles according to any of items 9 to 11 above, wherein a treatment temperature in the reduction treatment is 1,300°C to 1,800°C.

[00224] Although the present invention has been described in detail with reference to specific embodiments, it is evident to those skilled in the art that various alterations and modifications can be made without departing from the spirit and scope of the present invention. This application is based on a Japanese Patent Application (Japanese Patent Application No. 2023-037657) filed on March 10, 2023, the contents of which are incorporated herein by reference. Petition 870250080496, dated 08 / 09 / 2025, pages 134 / 146

Claims

1 / 4 CLAIMS 1. Glass containing fine metal particles, characterized in that it is a glass containing fine metal particles, wherein the numerical density of the fine metal particles for each particle diameter in any cross-section of the glass is in the following ranges, and the area ratio of the fine metal particles in any cross-section of the glass is from 0% to 0.15% relative to the total area of ​​any cross-section, particle diameter of more than 1 μm and 5 μm or less: 0 to 1,000 particles / mm2, particle diameter of more than 5 μm and 10 μm or less: 0 to 30 particles / mm2, particle diameter of more than 10 μm and 100 μm or less: 0 to 5 particles / mm2, particle diameter of more than 100 μm and 500 μm or less: 0 to 0.5 particles / mm2, particle diameter greater than 500 μm: substantially not contained.

2. Glass containing fine metal particles, according to claim 1, characterized in that an absolute ABS (Tv-Tiioo) value of a difference between a visible light transmittance Tv at a thickness of 2 mm and a transmittance Tnoo at a wavelength of 1100 nm at a thickness of 2 mm is 30% or less.

3. Glass containing fine metal particles, according to claim 1 or 2, characterized in that the fine metal particles contain at least one element selected from the group consisting of Fe, Si, Co, Cr, Ni, Ti, P, Sb, W and Nb.

4. Glass containing fine metal particles, according to Petition 870250080496, dated 08 / 09 / 2025, pp. 135 / 146 2 / 4, any of claims 1 to 3, characterized in that when a melt obtained by melting glass containing fine metal particles is subjected to a bubbling oxidation treatment using an atmosphere at 1,500°C for 120 minutes to obtain a glass, the glass obtained has a visible light transmittance Tv of 50% or more at a thickness of 2 mm.

5. Glass containing fine metal particles, according to any one of claims 1 to 4, characterized in that, in terms of % by mass on an oxide basis, when a melt obtained by melting glass containing fine metal particles is subjected to a bubbling oxidation treatment using an atmosphere at 1,500°C for 120 minutes to obtain a glass, an NWF ratio after / before is from 0.40 to 1.50, the NWF ratio after / before being a ratio of the total content of a network-forming oxide in the glass obtained to the total content of the network-forming oxide in the glass containing fine metal particles, and an NWM ratio after / before is from 0.60 to 2.00, the NWM ratio after / before being a ratio of the total content of a network-modifying oxide in the glass obtained to the total content of the network-modifying oxide in the glass containing fine metal particles.

6. Glass containing fine metal particles, according to any one of claims 1 to 5, characterized in that the average concentration of Fe2O3 in the glass containing fine metal particles is from 0.001% to 0.5% in terms of % by mass on an oxide basis.

7. Glass containing fine metal particles, according to any one of claims 1 to 6, characterized in that when a melt obtained by melting glass containing fine metal particles is subjected to a bubbling oxidation treatment using an atmosphere at 1,500°C for 30 minutes to obtain a glass, the glass obtained substantially does not contain fine metal particles with a particle diameter of 1 μm or more.

8. Glass containing fine metal particles, according to any one of claims 1 to 7, characterized in that a shape occupying 80% or more by mass is a crushed chunk shape or a spherical shape with a size of 1 mm to 100 mm.

9. A method for producing glass containing fine metal particles, which is a method for producing glass containing fine metal particles, as defined in any one of claims 1 to 8, the method characterized in that it comprises: obtaining a melt by melting a glass-containing feedstock; and subjecting the melt to a reduction treatment.

10. Method for producing a glass containing fine metal particles, according to claim 9, characterized in that in the reduction treatment, at least one element selected from the group consisting of a simple substance and a compound containing at least one element selected from the group consisting of C, Al, Si, Ca, Ti and H, and a mixture containing the simple substance and the compound is used as a reducing agent.

11. Method for producing a glass containing fine metallic particles, according to claim 10, characterized in that the reducing agent contains at least one selected from the group consisting of a simple substance and a compound containing at least one element selected from the group consisting of C, Si and H, and a mixture containing the simple substance and the compound.

12. Method for producing a glass containing fine metallic particles, according to any one of claims 9 to 11, Petition 870250080496, dated 08 / 09 / 2025, p. 137 / 146 4 / 4 characterized in that the treatment temperature in the reduction treatment is from 1,300°C to 1,800°C. Petition 870250080496, dated 09 / 08 / 2025, p. 138 / 146

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