Optical glass, glass raw materials for press molding, optical element blanks and optical elements

Abstract

The present invention provides an optical glass having a low ratio of expensive glass components in the glass composition, a high refractive index, and low dispersion. In the glass composition of the optical glass expressed in terms of cation percentage, Ta 5 + content is 0-5 cation%, cation ratio (Ti 4+ / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ )) is 0.60~1.00, the cation ratio ((Si 4+ +B 3+ ) / (La 3+ +Gd 3+ +Y 3+ )) is 0.30~2.40, and the cation ratio ((Si 4+ +B 3+ ) / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ )) is 0.30~34.00, the cation ratio ((La 3+ +Gd 3+ +Y 3+ ) / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ )) is 0.30~33.00, the cation ratio ((Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) / (La 3+ +Y 3+ )) is 0.00~1.50, the cation ratio ((Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) / (Si 4+ +B 3+ )) is 0.00~1.00, the cation ratio ((Gd 3+ +Nb 5+ +W 6+ ) / (Si 4+ +B 3+ +Zn 2+ +La 3+ +Y 3+ +Zr 4+ +Ti 4+)) is 0.000-0.100, the refractive index nd of the optical glass is 1.9000-2.1500, and the Abbe number νd is 20.0-35.0.

Description

[0001] This application is a divisional application of an application filed on October 10, 2019, with application number 201910957175.4 and invention name “Optical glass, glass raw materials for press molding, optical element blanks and optical elements”. Technical Field

[0002] The present invention relates to optical glass, a glass material for press molding, an optical element blank, and an optical element. Background Art

[0003] Optical glass having a high refractive index and low dispersion (high refractive index, low dispersion glass) is useful as a material for optical elements. Such high refractive index, low dispersion glass is disclosed in Patent Document 1, for example.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2009-203155 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] High-refractive-index, low-dispersion glass as disclosed in Patent Document 1 can correct chromatic aberration and achieve miniaturization of the optical system by combining a lens formed of this glass with a lens formed of ultra-low-dispersion glass to form a cemented lens.

[0009] However, the optical glass described in Patent Document 1 contains a large amount of expensive components (e.g., Ta2O5) among the various glass components. However, in order to achieve low cost of optical elements formed from high-refractive-index, low-dispersion glass, it is desired to reduce the proportion of expensive glass components in the glass composition of the optical glass.

[0010] One embodiment of the present invention provides optical glass having a low ratio of expensive glass components in the glass composition, a high refractive index, and low dispersion.

[0011] Solutions to the Problem

[0012] One embodiment of the present invention relates to an optical glass, wherein, in the glass composition of the optical glass expressed in cation %,

[0013] Ta 5 + The content is in the range of 0 to 5 cation %,

[0014] Ti 4+ Content relative to Ti 4+ 、Nb 5+ 、W6+ and Bi 3+ The total cation content ratio (Ti 4+ / (Ti 4+ +Nb 5+ +W 6+ +Bi 3 + )) is in the range of 0.60 to 1.00,

[0015] Si 4+ With B 3+ The total content relative to La 3+ 、Gd 3+ and Y 3+ The total cation content ratio ((Si 4+ +B 3+ ) / (La 3+ +Gd 3+ +Y 3+ )) is in the range of 0.30 to 2.40,

[0016] Si 4+ With B 3+ The total content relative to Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total cation content ratio ((Si 4+ +B 3+ ) / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ )) is in the range of 0.30 to 34.00,

[0017] La 3+ 、Gd 3+ and Y 3+ The total content relative to Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total cation content ratio (La 3+ +Gd 3 + +Y 3+ ) / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ )) is in the range of 0.30 to 33.00,

[0018] Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ and Zn2+ The total content relative to La 3+ With Y 3+ The total cation content ratio (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) / (La 3+ +Y 3+ )) is in the range of 0.00 to 1.50,

[0019] Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ and Zn 2+ The total content relative to Si 4+ With B 3+ The total cation content ratio (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) / (Si 4+ +B 3+ )) is in the range of 0.00 to 1.00,

[0020] Gd 3+ 、Nb 5+ and W 6+ The total content relative to Si 4+ 、B 3+ 、Zn 2+ 、La 3+ 、Y 3+ 、Zr 4+ and Ti 4+ The total cation content ratio ((Gd 3+ +Nb 5+ +W 6+ ) / (Si 4+ +B 3+ +Zn 2+ +La 3+ +Y 3+ +Zr 4+ +Ti 4+ )) is in the range of 0.000 to 0.100,

[0021] The refractive index nd of the optical glass is in the range of 1.9000 to 2.1500, and the Abbe number νd is in the range of 20.0 to 35.0.

[0022] Among the raw material compounds of optical glass, Ta compound, Gd compound, Nb compound and W compound are relatively expensive.5 + content is suppressed to the above range. 3+ 、Nb 5+ and W 6+ The proportion of Gd in the glass composition is also suppressed. 3+ 、Nb 5+ and W 6+ , cation ratio ((Gd 3+ +Nb 5+ +W 6+ ) / (Si 4+ +B 3+ +Zn 2+ +La 3+ +Y 3+ +Zr 4+ +Ti 4+ )) is within the above range. That is, in the glass composition of the above optical glass, Ta as an expensive glass component 5 +、Gd 3+ 、Nb 5+ and W 6+ By adjusting the glass composition in such a manner as to satisfy the various cation ratios described above, an optical glass having a high refractive index nd within the above range and an Abbe number νd within the above range (i.e., low dispersion) can be obtained.

[0023] Effects of the Invention

[0024] According to one embodiment of the present invention, an optical glass having optical properties (nd and νd) useful as a material for optical elements and contributing to the cost reduction of optical elements can be provided. Furthermore, according to one embodiment, an optical glass further having one or more of the following properties: high glass stability, low specific gravity, and low tinting (high transmittance) can be provided. Furthermore, according to one embodiment of the present invention, a glass raw material for press molding, an optical element blank, and an optical element formed from the above optical glass can be provided. DETAILED DESCRIPTION

[0025] [Optical glass]

[0026] In the present invention and this specification, unless otherwise specified, the content and total content of cationic components are expressed as cation %, and unless otherwise specified, the content and total content of anionic components are expressed as anion %.

[0027] Here, "cation %" is a value calculated as "(number of cations of interest / total number of cations in glass component) x 100", and represents the molar percentage of the amount of cations of interest relative to the total amount of cationic components.

[0028] Furthermore, "anion %" is a value calculated as "(number of anions of interest / total number of anions in glass component) x 100" and represents the molar percentage of the anion amount of interest relative to the total amount of anion components.

[0029] The molar ratio of the contents of the cationic components is equal to the content ratio of the cationic component of interest expressed in cation %, and the molar ratio of the contents of the anionic components is equal to the content ratio of the anionic component of interest expressed in anion %.

[0030] The molar ratio of the content of the cationic component to the content of the anionic component is the ratio of the contents of the components of interest (expressed in mol %) when the total amount of all cationic components and all anionic components is taken as 100 mol %.

[0031] The content of each component can be quantified by a known method, for example, inductively coupled plasma atomic emission spectrometry (ICP-AES), inductively coupled plasma mass spectrometry (ICP-MS), ion chromatography, or the like.

[0032] In the present invention and this specification, "0% content of a component" or "no content" or "no introduction" means that the component is substantially not contained and the content of the component is below the impurity level. Below the impurity level means, for example, less than 0.01%.

[0033] Hereinafter, the above-mentioned optical glass (may be simply referred to as "glass") will be described in more detail.

[0034] <Glass Composition>

[0035] In the above optical glass, Ta 5 + Ta, an expensive glass component, has a content of 0 to 5 cation %. 5 + content is small. From the perspective of further cost reduction of optical elements, Ta 5 The Ta content is preferably 4% or less, more preferably 3% or less, further preferably 2% or less, further preferably 1% or less, and further preferably does not contain Ta. 5 +.

[0036] In the above optical glass, Gd 3+ 、Nb 5+ and W 6+ The total content relative to Si 4+ 、B 3+ 、Zn 2+ 、La 3+ 、Y 3+ 、Zr 4+ and Ti 4+ The total cation content ratio ((Gd 3++Nb 5+ +W 6+ ) / (Si 4+ +B 3+ +Zn 2+ +La 3+ +Y 3+ +Zr 4+ +Ti 4+ )) is in the range of 0.000 to 0.100. That is, in the glass composition of the above optical glass, Gd 3+ 、Nb 5+ and W 6+ From the perspective of further cost reduction of optical elements, the above cation ratio ((Gd 3+ +Nb 5+ +W 6+ ) / (Si 4+ +B 3+ +Zn 2+ +La 3+ +Y 3+ +Zr 4+ +Ti 4 + )) is preferably 0.090 or less, more preferably 0.080 or less, further preferably 0.070 or less, even more preferably 0.060 or less, even more preferably 0.050 or less, even more preferably 0.040 or less, even more preferably 0.030 or less, even more preferably 0.025 or less, 0.020 or less, 0.015 or less, 0.010 or less, 0.007 or less, 0.005 or less, 0.004 or less, 0.003 or less, 0.002 or less, or 0.001 or less, and even more preferably 0.000. That is, it is even more preferable that Gd is not contained. 3+ 、Nb 5+ and W 6+ .

[0037] From the viewpoint of reducing the cost of optical elements and reducing the specific gravity of glass, Gd 3+ With W 6+ The total content (Gd 3+ +W 6+ ) is preferably 8% or less, more preferably 6% or less, further preferably 5% or less, further preferably 4% or less, further preferably 3% or less, further preferably 2% or less, further preferably 1% or less. The above total content (Gd 3+ +W 6+ ) can be 0% or more, and is particularly preferably 0%.

[0038] In addition, in the above optical glass, Gd 3+ With W6+ The total content relative to Si 4+ 、B 3+ 、Zn 2+ 、La 3+ 、Y 3+ 、Zr 4+ and Ti 4+ The total cation content ratio ((Gd 3+ +W 6+ ) / (Si 4+ +B 3+ +Zn 2+ +La 3+ +Y 3+ +Zr 4+ +Ti 4+ )) is preferably in the range of 0.000 to 0.080. From the viewpoint of further cost reduction of optical elements and low specific gravity of glass, the above cation ratio ((Gd 3+ +W 6+ ) / (Si 4+ +B 3+ +Zn 2+ +La 3+ +Y 3+ +Zr 4+ +Ti 4+ )) is preferably 0.070 or less, more preferably 0.060 or less, further preferably 0.050 or less, further preferably 0.045 or less, further preferably 0.040 or less, further preferably 0.035 or less, further preferably 0.030 or less, further preferably 0.025 or less, further preferably 0.020 or less, further preferably 0.015 or less, further preferably 0.010 or less, particularly preferably 0.007 or less, further particularly preferably 0.005 or less, further particularly preferably 0.004 or less, further particularly preferably 0.003 or less, further particularly preferably 0.002 or less, further particularly preferably 0.001 or less. The above cation ratio ((Gd 3+ +W 6+ ) / (Si 4+ +B 3+ +Zn 2+ +La 3+ +Y 3+ +Zr 4+ +Ti 4+ )) is particularly preferably 0.000. That is, the optical glass particularly preferably does not contain Gd 3+ and W 6+ .

[0039] Si 4+ and B 3+It is a network-forming component of glass. From the perspective of improving glass stability, Si 4+ With B 3+ The total content (Si 4+ +B 3+ ) is preferably 25% or more, more preferably 27% or more, further preferably 28% or more, further preferably 29% or more, further preferably 30% or more, further preferably 31% or more. On the other hand, from the viewpoint of suppressing the decrease in refractive index, the above-mentioned total content (Si 4+ +B 3+ ) is preferably 55% or less, more preferably 45% or less, further preferably 40% or less, further preferably 37% or less, further preferably 35% or less, further preferably 34% or less.

[0040] From the viewpoint of further improving the glass stability of the above optical glass as a high refractive index and low dispersion glass, and from the viewpoint of further improving the refractive index, B 3+ Content relative to Si 4+ With B 3+ The total content of cation ratio (B 3+ / (Si 4+ +B 3+ )) is preferably 0.20 or more, more preferably 0.30 or more, further preferably 0.40 or more, further preferably 0.50 or more, further preferably 0.55 or more, further preferably 0.60 or more, further preferably 0.61 or more, further preferably 0.62 or more, further preferably 0.63 or more, further preferably 0.64 or more, further preferably 0.65 or more. In addition, from the same viewpoint, the above-mentioned cation ratio (B 3+ / (Si 4+ +B 3+ )) is preferably 0.95 or less, more preferably 0.90 or less, further preferably 0.85 or less, further preferably 0.83 or less, further preferably 0.80 or less, further preferably 0.79 or less, further preferably 0.78 or less, further preferably 0.77 or less, further preferably 0.76 or less, further preferably 0.75 or less. From the viewpoint of improving the meltability of the glass, it is also preferred that the cation ratio (B) is 0.95 or less, more preferably 0.90 or less, further preferably 0.85 or less, further preferably 0.83 or less, further preferably 0.80 or less, further preferably 0.79 or less, further preferably 0.78 or less, further preferably 0.77 or less, further preferably 0.76 or less, further preferably 0.75 or less. 3+ / (Si 4+ +B 3+ )) is above the lower limit of the above examples. In terms of improving the viscosity of the glass during melting, it is also preferred that the above cation ratio (B 3+ / (Si 4+ +B 3+)) is below the upper limit exemplified above. In addition, from the viewpoint of reducing the change of glass composition caused by volatilization during melting and the change of optical properties caused thereby, from the viewpoint of improving at least one of the chemical durability, weather resistance and machinability of glass, and from the viewpoint of reducing coloration, it is preferred that the above cation ratio (B) is less than or equal to 0. 3+ / (Si 4+ +B 3+ )) is below the upper limit exemplified above.

[0041] Regarding Si as a network-forming component of glass 4+ With B 3+ From the perspective of improving the stability, melting property, formability, chemical durability, weather resistance, machinability, etc. of the glass and reducing coloring, Si 4+ Content and B 3+ The preferred ranges of the respective contents are as follows.

[0042] Si 4+ The content is preferably 2% or more, more preferably 3% or more, further preferably 4% or more, further preferably 5% or more, further preferably 6% or more, further preferably 7% or more. 4+ The content is preferably 20% or less, more preferably 18% or less, further preferably 16% or less, further preferably 14% or less, further preferably 12% or less.

[0043] B 3+ The content is preferably 10% or more, more preferably 15% or more, further preferably 16% or more, further preferably 17% or more, further preferably 18% or more, further preferably 19% or more. 3+ The content is preferably 40% or less, more preferably 40% or less, further preferably 35% or less, further preferably 30% or less, further preferably 26% or less, further preferably 25% or less, further preferably 24% or less, further preferably 23% or less.

[0044] La 3+ 、Gd 3+ and Y 3 These components have the effect of suppressing the decrease in the Abbe number and increasing the refractive index. In addition, these components also have the effect of improving the chemical durability and / or weather resistance of the glass and raising the glass transition temperature.

[0045] From the viewpoint of suppressing the decrease in refractive index, La 3+ 、Gd 3+ and Y 3+ The total content (La 3+ +Gd3+ +Y 3+ ) is preferably 20% or more, more preferably 22% or more, further preferably 24% or more, further preferably 26% or more, further preferably 28% or more, further preferably 30% or more, further preferably 32% or more, further preferably 33% or more, further preferably 34% or more, further preferably 35% or more, further preferably 36% or more. In addition, from the viewpoint of suppressing the reduction of the chemical durability and / or weather resistance of the glass and the viewpoint of suppressing the reduction of the glass transition temperature, it is also preferred that the total content (La) is 20% or more, more preferably 22% or more, further preferably 24% or more, further preferably 26% or more, further preferably 28% or more, further preferably 30% or more, further preferably 32% or more, further preferably 33% or more, further preferably 34% or more, further preferably 35% or more, further preferably 36% or more. 3+ +Gd 3+ +Y 3+ ) is above the lower limit exemplified above. If the glass transition temperature is lowered, the glass becomes easily broken when subjected to mechanical processing (cutting, grinding, polishing, etc.) (reduction in machinability). Therefore, suppressing the reduction of the glass transition temperature will lead to an improvement in machinability. From the above viewpoints, it is also preferred that the total content (La 3+ +Gd 3+ +Y 3+ ) is greater than the lower limit exemplified above.

[0046] On the other hand, from the viewpoint of improving glass stability, the total content (La 3+ +Gd 3+ +Y 3+ ) is preferably less than 60%, more preferably less than 55%, further preferably less than 50%, further preferably less than 47%, further preferably less than 45%, further preferably less than 44%, further preferably less than 43%, further preferably less than 42%, further preferably less than 41%, further preferably less than 40%, further preferably less than 39%.

[0047] From the perspective of improving glass stability and reducing specific gravity, in the above optical glass, relative to La 3 + 、Gd 3+ and Y 3+ The total content of Si as a network forming component of glass 4+ With B 3+ The total cation content ratio ((Si 4+ +B 3 + ) / (La 3+ +Gd 3+ +Y 3+)) is 0.30 or more, preferably 0.50 or more, more preferably 0.60 or more, further preferably 0.65 or more, further preferably 0.70 or more, further preferably 0.75 or more, further preferably 0.77 or more, further preferably 0.79 or more, further preferably 0.80 or more.

[0048] From the viewpoint of increasing the refractive index, the above cation ratio ((Si 4+ +B 3+ ) / (La 3+ +Gd 3+ +Y 3+ )) is 2.40 or less, preferably 2.00 or less, more preferably 1.50 or less, further preferably 1.30 or less, further preferably 1.10 or less, further preferably 1.05 or less, further preferably 1.00 or less, further preferably 0.95 or less, further preferably 0.94 or less, further preferably 0.93 or less, further preferably 0.92 or less, further preferably 0.91 or less, and particularly preferably 0.90 or less.

[0049] About La 3+ 、Gd 3+ and Y 3+ The preferred ranges of the contents of the various components are as follows.

[0050] La 3+ The content is preferably 20% or more, more preferably 21% or more, further preferably 22% or more, further preferably 23% or more, further preferably 24% or more, further preferably 25% or more, further preferably 26% or more, further preferably 27% or more. 3+ The content is preferably 60% or less, more preferably 57% or less, further preferably 55% or less, further preferably 53% or less, further preferably 50% or less, further preferably 47% or less, further preferably 45% or less, further preferably 43% or less, further preferably 40% or less, further preferably 37% or less, further preferably 35% or less, particularly preferably 34% or less, further preferably 33% or less, further particularly preferably 32% or less, further particularly preferably 31% or less, further particularly preferably 30% or less, further particularly preferably 29% or less.

[0051] Gd 3+ The content is preferably 8% or less, more preferably 6% or less, further preferably 4% or less, further preferably 3% or less, further preferably 2% or less, further preferably 1% or less. 3+The content can be 0% or more. From the viewpoint of further cost reduction and low specific gravity of optical elements, Gd is particularly preferably 3+ The content is 0%, that is, it does not contain Gd 3 + .

[0052] From the perspective of improving meltability and enhancing glass stability, Y 3+ The content is preferably 0% or more, more preferably 1% or more, further preferably 2% or more, further preferably 4% or more, further preferably 6% or more, further preferably 7% or more, further preferably 8% or more, further preferably 9% or more. 3+ The content is preferably 30% or less, more preferably 25% or less, further preferably 20% or less, further preferably 17% or less, further preferably 15% or less, further preferably 14% or less, further preferably 13% or less, further preferably 12% or less, further preferably 11% or less.

[0053] Yb has a large atomic weight among rare earth elements and tends to increase the specific gravity of glass. Furthermore, Yb has absorption in the near-infrared region. On the other hand, replacement lenses for single-lens reflex cameras and lenses for surveillance cameras are expected to have high transmittance in the near-infrared region. Therefore, in order to produce glass useful for the production of these lenses, Yb is desired. 3+ From the above point of view, Yb 3+ The content is preferably 10% or less, more preferably 5% or less, further preferably 3% or less, and further preferably 1% or less. 3+ The content can be above 0%, and Yb is particularly preferred. 3+ The content is 0%, that is, it does not contain Yb 3+ .

[0054] Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ It is a component that increases the refractive index and, when contained in an appropriate amount, also increases the stability of the glass. 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total content (Ti 4+ +Nb 5+ +W 6+ +Bi 3+) is preferably 0% or more, more preferably 5% or more, further preferably 10% or more, further preferably 15% or more, further preferably 16% or more, further preferably 17% or more, further preferably 18% or more, further preferably 19% or more, further preferably 20% or more, further preferably 21% or more. On the other hand, from the viewpoint of maintaining glass stability and suppressing the decrease in Abbe number, Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total content (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ ) is preferably less than 50%, more preferably less than 40%, further preferably less than 30%, further preferably less than 29%, further preferably less than 28%, further preferably less than 27%, further preferably less than 26%, further preferably less than 25%, further preferably less than 24%.

[0055] From the perspective of maintaining glass stability and suppressing high dispersion and reducing coloration, in the above optical glass, La 3+ 、Gd 3+ and Y 3+ The total content relative to Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total cation content ratio (La 3+ +Gd 3+ +Y 3+ ) / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ )) is 0.30 or more, more preferably 0.40 or more, further preferably 0.50 or more, further preferably 0.60 or more, further preferably 0.70 or more, further preferably 0.80 or more, further preferably 0.90 or more, further preferably 1.00 or more, further preferably 1.10 or more, further preferably 1.20 or more, further preferably 1.30 or more, particularly preferably 1.40 or more, further particularly preferably 1.50 or more. On the other hand, from the viewpoint of suppressing the decrease in the refractive index and maintaining the stability of the glass and the viewpoint of low specific gravity, in the above-mentioned optical glass, the cation ratio ((La)) is 0.30 or more, more preferably 0.40 or more, further preferably 0.50 or more, further preferably 0.60 or more, further preferably 0.70 or more, further preferably 0.80 or more, further preferably 0.90 or more, further preferably 1.00 or more, further preferably 1.10 or more, further preferably 1.20 or more, further preferably 1.30 or more, particularly preferably 1.40 or more, further particularly preferably 1.50 or more. 3+ +Gd 3+ +Y 3+ ) / (Ti 4+ +Nb 5+ +W6+ +Bi 3+ )) is 33.00 or less, preferably 20.00 or less, more preferably 10.00 or less, further preferably 5.00 or less, further preferably 4.00 or less, further preferably 3.00 or less, further preferably 2.50 or less, further preferably 2.20 or less, further preferably 2.00 or less, further preferably 1.90 or less, further preferably 1.80 or less, and particularly preferably 1.70 or less.

[0056] From the viewpoint of increasing the refractive index, in the above optical glass, relative to Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total content of Si as a network forming component of glass 4+ With B 3+ The total cation content ratio ((Si 4+ +B 3+ ) / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ )) is 34.00 or less, preferably 30.00 or less, more preferably 20.00 or less, further preferably 10.00 or less, further preferably 5.00 or less, further preferably 4.00 or less, further preferably 3.00 or less, further preferably 2.50 or less, further preferably 2.20 or less, further preferably 2.00 or less, further preferably 1.90 or less, further preferably 1.80 or less, particularly preferably 1.70 or less, and further particularly preferably 1.60 or less. On the other hand, from the viewpoint of suppressing high dispersion, maintaining glass stability, and reducing coloration, the above-mentioned cation ratio ((Si 4+ +B 3+ ) / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ )) is 0.30 or more, preferably 0.40 or more, more preferably 0.50 or more, further preferably 0.60 or more, further preferably 0.70 or more, further preferably 0.80 or more, further preferably 0.85 or more, further preferably 0.90 or more, further preferably 0.95 or more, further preferably 1.00 or more, further preferably 1.05 or more, particularly preferably 1.10 or more, more particularly preferably 1.15 or more, further particularly preferably 1.20 or more, further particularly preferably 1.25 or more, further particularly preferably 1.30 or more.

[0057] From the perspective of maintaining glass stability and reducing coloration, in the above optical glass, Ti 4+ Content relative to Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total cation content ratio (Ti 4+ / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ )) is in the range of 0.60 to 1.00. The above cation ratio (Ti 4+ / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ )) is preferably 0.70 or more, more preferably 0.75 or more, further preferably 0.80 or more, further preferably 0.85 or more, further preferably 0.90 or more, further preferably 0.95 or more, further preferably 1.00.

[0058] About Ti 4+ 、Nb 5+ and W 6+ The preferred ranges of the contents of the various components are as follows.

[0059] Ti 4+ The content is preferably 0% or more, more preferably 5% or more, further preferably 10% or more, further preferably 15% or more, further preferably 16% or more, further preferably 17% or more, further preferably 18% or more, further preferably 19% or more, further preferably 20% or more, further preferably 21% or more. 4+ The content is preferably 50% or less, more preferably 40% or less, further preferably 30% or less, further preferably 29% or less, further preferably 28% or less, further preferably 27% or less, further preferably 26% or less, further preferably 25% or less, further preferably 24% or less.

[0060] Nb 5+ The content is preferably 8% or less, more preferably 6% or less, further preferably 5% or less, further preferably 4% or less, further preferably 3% or less, further preferably 2% or less, further preferably 1% or less. 5+ The content may be 0% or more. From the viewpoint of further reducing the cost of optical elements, Nb is particularly preferably 5+ The content is 0%, that is, no Nb 5+ .

[0061] W 6+ The content is preferably 8% or less, more preferably 6% or less, further preferably 5% or less, further preferably 4% or less, further preferably 3% or less, further preferably 2% or less, further preferably 1% or less. 6+ The content can be 0% or more. From the perspective of further cost reduction of optical elements, low specific gravity of glass and reduction of coloration, W is particularly preferred. 6+ The content is 0%, that is, it does not contain W 6+ .

[0062] From the perspective of reducing the cost of optical elements and reducing the specific gravity of glass, Nb 5+ With W 6+ The total content (Nb 5+ +W 6+ ) is preferably 8% or less, more preferably 6% or less, further preferably 5% or less, further preferably 4% or less, further preferably 3% or less, further preferably 2% or less, further preferably 1% or less. The above total content (Nb 5+ +W 6+ ) can be 0% or more, and is particularly preferably 0%.

[0063] From the perspective of reducing the cost of optical elements and reducing the specific gravity of glass, Gd 3+ 、Nb 5+ and W 6+ The total content (Gd 3+ +Nb 5+ +W 6+ ) is preferably 8% or less, more preferably 6% or less, further preferably 5% or less, further preferably 4% or less, further preferably 3% or less, further preferably 2% or less, further preferably 1% or less. The above total content (Gd 3+ +Nb 5+ +W 6+ ) can be 0% or more, and is particularly preferably 0%.

[0064] Bi 3+ It is a component that increases the refractive index and reduces the Abbe number. In addition, it is also a component that easily causes an increase in specific gravity and coloration. From the perspective of producing glass with the above-mentioned optical properties, less coloration, and low specific gravity, Bi 3+ The preferred range of the content is as follows.

[0065] Bi 3+The content is preferably 20% or less, more preferably 15% or less, further preferably 10% or less, further preferably 7% or less, further preferably 5% or less, further preferably 3% or less, further preferably 1% or less. 3+ The content may be 0% or more, or may be 0%.

[0066] From the perspective of maintaining glass stability, as well as the perspective of high refractive index and low dispersion, Mg 2+ , Ca 2+ 、Sr 2 + And Ba 2+ The total content (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ) is preferably 20% or less, more preferably 15% or less, further preferably 10% or less, further preferably 7% or less, further preferably 6% or less, further preferably 5% or less, further preferably 4% or less, further preferably 3% or less, further preferably 2% or less, further preferably 1% or less. In addition, the above total content (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ) can be 0% or more. In one embodiment, the total content (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ) is preferably 0%.

[0067] From the perspective of improving the meltability of glass, maintaining glass stability and suppressing excessive increase in glass transition temperature, Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ and Zn 2+ The total content (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) is preferably 0% or more, more preferably 0.05% or more, and further preferably 0.1% or more. On the other hand, from the perspective of maintaining glass stability, and from the perspective of high refractive index and low dispersion, the total content (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+) is preferably 30% or less, more preferably 25% or less, further preferably 20% or less, further preferably 15% or less, further preferably 10% or less, further preferably 8% or less, further preferably 6% or less, further preferably 4% or less.

[0068] From the viewpoint of maintaining glass stability, high refractive index and low dispersion, Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ and Zn 2+ The total content relative to La 3+ With Y 3+ The total cation content ratio (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) / (La 3+ +Y 3+ )) is 1.500 or less, preferably 1.000 or less, more preferably 0.800 or less, further preferably 0.500 or less, even more preferably 0.400 or less, even more preferably 0.300 or less, even more preferably 0.250 or less, even more preferably 0.200 or less, even more preferably 0.150 or less, even more preferably 0.100 or less, even more preferably 0.080 or less, even more preferably 0.060 or less, even more preferably 0.040 or less, particularly preferably 0.020 or less, even more particularly preferably 0.010 or less, even more particularly preferably 0.007 or less, even more particularly preferably 0.005 or less. In addition, the above-mentioned cation ratio ((Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) / (La 3+ +Y 3+ )) is greater than 0.00. From the viewpoint of improving the solubility of the glass, maintaining the stability of the glass and inhibiting an excessive increase in the glass transition temperature, it is preferably greater than 0.00, more preferably greater than 0.001, further preferably greater than 0.003, and even more preferably greater than 0.005.

[0069] From the perspective of maintaining glass stability and reducing specific gravity, Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ and Zn 2+ The total content relative to Si4+ With B 3+ The total cation content ratio (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) / (Si 4+ +B 3+ )) is 1.000 or less, preferably 0.900 or less, more preferably 0.800 or less, further preferably 0.700 or less, even more preferably 0.600 or less, even more preferably 0.550 or less, even more preferably 0.500 or less, even more preferably 0.450 or less, even more preferably 0.400 or less, even more preferably 0.350 or less, even more preferably 0.300 or less, even more preferably 0.250 or less, even more preferably 0.200 or less, particularly preferably 0.150 or less, even more preferably 0.100 or less, and even more preferably 0.090 or less. In addition, the cation ratio ((Mg)) is 1.000 or less, preferably 0.90 or less, more preferably 0.100 or less, and even more preferably 0.090 or less. 2+ +Ca 2 + +Sr 2+ +Ba 2+ +Zn 2+ ) / (Si 4+ +B 3+ )) is 0.00 or more, and from the viewpoint of improving the meltability of the glass and suppressing an excessive increase in the glass transition temperature, is preferably 0.001 or more, more preferably 0.003 or more, and further preferably 0.005 or more.

[0070] Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2 + are all components that have the effect of improving the meltability of glass. However, when the content of these components increases, there is a tendency for the glass stability to decrease. From the above viewpoints, the preferred range of the content of each of these components is as follows.

[0071] Mg 2+ The content is preferably 20% or less, more preferably 15% or less, further preferably 10% or less, further preferably 7% or less, further preferably 6% or less, further preferably 5% or less, further preferably 4% or less, further preferably 3% or less, further preferably 2% or less, further preferably 1% or less. 2+ The content may be 0% or more, or may be 0%.

[0072] Ca 2The Ca content is preferably 20% or less, more preferably 15% or less, further preferably 10% or less, further preferably 7% or less, further preferably 6% or less, further preferably 5% or less, further preferably 4% or less, further preferably 3% or less, further preferably 2% or less, further preferably 1% or less. 2 + The content may be 0% or more, or may be 0%.

[0073] Sr 2 The content of Sr is preferably 20% or less, more preferably 15% or less, further preferably 10% or less, further preferably 7% or less, further preferably 6% or less, further preferably 5% or less, further preferably 4% or less, further preferably 3% or less, further preferably 2% or less, further preferably 1% or less. 2 + The content may be 0% or more, or may be 0%.

[0074] Ba 2 The content of Ba is preferably 20% or less, more preferably 15% or less, further preferably 10% or less, further preferably 7% or less, further preferably 6% or less, further preferably 5% or less, further preferably 4% or less, further preferably 3% or less, further preferably 2% or less, further preferably 1% or less. 2 + The content may be 0% or more, or may be 0%.

[0075] From the perspective of improving the meltability, stability, formability, machinability, etc. of the glass and achieving the above-mentioned optical properties, Zn 2+ The preferred range of the content is as follows.

[0076] Zn 2+ The content can be 0% or more, preferably 0.03% or more, more preferably 0.05% or more, further preferably 0.08% or more, and even more preferably 0.1% or more. 2+ The content is preferably 30% or less, more preferably 25% or less, further preferably 20% or less, further preferably 15% or less, further preferably 10% or less, further preferably 8% or less, further preferably 6% or less, further preferably 4% or less.

[0077] About Zn 2+ From the perspective of improving glass stability and achieving the above-mentioned optical properties, Zn 2+ Content relative to La 3+ With Y 3+ The total cation content ratio (Zn 2+ / (La3+ +Y 3 )) is preferably 0.66 or less, more preferably 0.50 or less, further preferably 0.40 or less, even more preferably 0.30 or less, even more preferably 0.25 or less, even more preferably 0.20 or less, even more preferably 0.15 or less, even more preferably 0.13 or less, even more preferably 0.12 or less, even more preferably 0.11 or less, even more preferably 0.10 or less, particularly preferably 0.090 or less, even more preferably 0.085 or less, and even more preferably 0.080 or less. In addition, from the viewpoint of suppressing the decrease in glass transition temperature (and the improvement in machinability thereof) and improving chemical durability, it is also preferred that the above cation ratio (Zn 2+ / (La 3+ +Y 3+ )) is smaller. The above cation ratio (Zn 2+ / (La 3+ +Y 3+ )) can be 0.00% or more, and is preferably greater than 0.00% from the viewpoint of improving meltability and suppressing excessive increase in glass transition temperature. 2+ / (La 3+ +Y 3+ )) is more preferably 0.001 or more, further preferably 0.003 or more, and further preferably 0.005 or more.

[0078] From the perspective of improving glass stability and achieving the above-mentioned optical properties, Zn 2+ with Ba 2+ The total content relative to La 3+ The cation ratio of the content ((Zn 2+ +Ba 2+ ) / La 3+ ) is preferably 0.00 or more, more preferably 0.001 or more, further preferably 0.003 or more, further preferably 0.005 or more, further preferably 0.008 or more. From the viewpoint of improving meltability, reducing specific gravity, and suppressing excessive increase in glass transition temperature, the above cation ratio ((Zn 2+ +Ba 2+ ) / La 3+) is preferably 0.66 or less, more preferably 0.50 or less, further preferably 0.40 or less, even more preferably 0.30 or less, even more preferably 0.25 or less, even more preferably 0.20 or less, even more preferably 0.16 or less, even more preferably 0.14 or less, even more preferably 0.13 or less, even more preferably 0.12 or less, even more preferably 0.11 or less, particularly preferably 0.100 or less, and even more particularly preferably 0.090 or less.

[0079] From the perspective of improving glass stability and achieving the above-mentioned optical properties, Zn 2+ with Ba 2+ The total content relative to La 3+ With Y 3+ The total cation content ratio ((Zn 2+ +Ba 2+ ) / (La 3+ +Y 3+ )) is preferably 0.00 or more, more preferably 0.001 or more, further preferably 0.003 or more, and even more preferably 0.005 or more. From the viewpoint of improving meltability, reducing specific gravity, and suppressing excessive increase in glass transition temperature, the above cation ratio ((Zn 2+ +Ba 2+ ) / (La 3+ +Y 3+ )) is preferably 0.66 or less, more preferably 0.50 or less, further preferably 0.40 or less, even more preferably 0.30 or less, even more preferably 0.25 or less, even more preferably 0.20 or less, even more preferably 0.15 or less, even more preferably 0.13 or less, even more preferably 0.12 or less, even more preferably 0.11 or less, even more preferably 0.10 or less, particularly preferably 0.090 or less, even more particularly preferably 0.085 or less, even more particularly preferably 0.080 or less.

[0080] Li + The effect of lowering the glass transition temperature is strong. Therefore, when its content increases, the machinability tends to decrease. In addition, the glass stability, chemical durability and weather resistance also tend to decrease. Therefore, Li + The content is preferably 10% or less, more preferably 8% or less, further preferably 6% or less, further preferably 4% or less, further preferably 3% or less, further preferably 2% or less, further preferably 1% or less. + The content may be 0% or more, or may be 0%.

[0081] Na + , K+ , Rb + and Cs + Both have the effect of improving the melting property of glass, but when their content increases, the glass stability, chemical durability, weather resistance and machinability tend to decrease. + , K + , Rb + and Cs + The preferred ranges of the respective contents are as follows.

[0082] Na + The content is preferably 10% or less, more preferably 8% or less, further preferably 6% or less, further preferably 4% or less, further preferably 3% or less, further preferably 2% or less, further preferably 1% or less. + The content may be 0% or more, or may be 0%.

[0083] K + The content is preferably 10% or less, more preferably 8% or less, further preferably 6% or less, further preferably 4% or less, further preferably 3% or less, further preferably 2% or less, further preferably 1% or less. + The content may be 0% or more, or may be 0%.

[0084] Rb + The content is preferably 10% or less, more preferably 8% or less, further preferably 6% or less, further preferably 4% or less, further preferably 3% or less, further preferably 2% or less, further preferably 1% or less. + The content may be 0% or more, or may be 0%.

[0085] Cs + The content is preferably 10% or less, more preferably 8% or less, further preferably 6% or less, further preferably 4% or less, further preferably 3% or less, further preferably 2% or less, further preferably 1% or less. + The content may be 0% or more, or may be 0%.

[0086] Al 3+ It is a component that improves the chemical durability and weather resistance of glass. 3+ When the content of Al increases, there is sometimes a tendency for the refractive index to decrease, the glass stability to decrease, and the meltability to decrease. 3+ The preferred range of the content is as follows.

[0087] Al 3+The content is preferably 10% or less, more preferably 8% or less, further preferably 6% or less, further preferably 4% or less, further preferably 3% or less, further preferably 2% or less, further preferably 1% or less. 3+ The content may be 0% or more, or may be 0%.

[0088] Zr 4+ It is a component that increases the refractive index and, when contained in an appropriate amount, improves the stability of the glass. 4+ By increasing the glass transition temperature, it also has the effect of making the glass less prone to breakage during mechanical processing. 4+ The content is preferably 0% or more, more preferably 1% or more, further preferably 2% or more, further preferably 3% or more, further preferably 4% or more. From the viewpoint of improving glass stability, Zr 4+ The content is preferably 15% or less, more preferably 13% or less, further preferably 10% or less, further preferably 9% or less, further preferably 8% or less, further preferably 7% or less, further preferably 6% or less.

[0089] P 5+ It is a component that reduces the refractive index and also reduces the stability of the glass. However, if it is introduced in a very small amount, it may improve the stability of the glass. From the perspective of obtaining a glass having the above-mentioned optical properties and excellent glass stability, P 5+ The preferred range of the content is as follows.

[0090] P 5+ The content is preferably 5% or less, more preferably 4% or less, further preferably 3% or less, further preferably 2% or less, further preferably 1% or less. 5+ The content may be 0% or more, or may be 0%.

[0091] Ga 3+ 、In 3+ Sc 3+ and Hf 4+ However, these components are not necessary to obtain the above-mentioned glass. 3+ 、In 3+ Sc 3+ and Hf 4+ The preferred ranges of the respective contents are as follows.

[0092] Ga 3+The content is preferably 5% or less, more preferably 4% or less, further preferably 3% or less, further preferably 2% or less, further preferably 1% or less. 3+ The content may be 0% or more, or may be 0%.

[0093] In 3+ The content is preferably 5% or less, more preferably 4% or less, further preferably 3% or less, further preferably 2% or less, further preferably 1% or less. 3+ The content may be 0% or more, or may be 0%.

[0094] Sc 3+ The content is preferably 5% or less, more preferably 4% or less, further preferably 3% or less, further preferably 2% or less, further preferably 1% or less. 3+ The content may be 0% or more, or may be 0%.

[0095] Sc 3+ The content is preferably 5% or less, more preferably 4% or less, further preferably 3% or less, further preferably 2% or less, further preferably 1% or less. 3+ The content may be 0% or more, or may be 0%.

[0096] Hf 4+ The content is preferably 10% or less, more preferably 8% or less, further preferably 6% or less, further preferably 4% or less, further preferably 2% or less. 4+ The content may be 0% or more, or may be 0%.

[0097] Lu 3+ It has the effect of increasing the refractive index, but it is also a component that causes the specific gravity of the glass to increase. In addition, Lu is a heavy rare earth element like Gd and Yb. Therefore, from the perspective of stable supply of glass, it is desirable to use Lu. 3+ From the above point of view, Lu 3+ The content is preferably 10% or less, more preferably 8% or less, further preferably 6% or less, further preferably 4% or less, further preferably 2% or less. 3+ The content may be 0% or more, or may be 0%.

[0098] Ge 4+ It has the effect of increasing the refractive index, but from the perspective of further cost reduction of optical elements, Ge 4+ The content is preferably 10% or less, more preferably 8% or less, further preferably 6% or less, further preferably 4% or less, further preferably 2% or less.4+ The content may be 0% or more, or may be 0%.

[0099] Te 4+ It is a component that increases the refractive index, but from the viewpoint of environmental concerns, Te is preferably 4+ Low content. 4+ The content is preferably 5% or less, more preferably 4% or less, further preferably 3% or less, further preferably 2% or less, further preferably 1% or less. 4+ The content may be 0% or more, or may be 0%.

[0100] Pb, As, Cd, Tl, Be, and Se are all toxic. Therefore, it is preferable not to contain these elements, that is, not to introduce these elements into the glass as glass components.

[0101] U, Th, and Ra are all radioactive elements. Therefore, it is preferable not to contain these elements, that is, not to introduce these elements into the glass as glass components.

[0102] V, Cr, Mn, Fe, Co, Ni, Cu, Pr, Nd, Pm, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Ce increase the coloration of the glass or become a source of fluorescence, and are therefore not preferred elements for inclusion in glass for optical components. Therefore, it is preferred that these elements not be included, i.e., not be incorporated into the glass as glass components.

[0103] Sb and Sn are optionally added elements that function as clarifiers.

[0104] The Sb content of the above optical glass is expressed as Sb 3+ The content of Sb can be, for example, 0.40% or less, 0.20% or less, 0.10% or less, 0.05% or less, 0.02% or less, or 0.01% or less. 3+ The content may be 0.00% or more, or may be 0.00%.

[0105] The Sn content of the above optical glass is Sn 2+ The content of Sb can be, for example, 0.40% or less, 0.20% or less, 0.10% or less, 0.05% or less, 0.02% or less, or 0.01% or less. 3+ The content may be 0.00% or more, or may be 0.00%.

[0106] The cationic components have been described above. Next, the anionic components will be described.

[0107] The above optical glass may be an oxide glass, which may contain O 2- As anionic component.2- The content is preferably 95.0 anion % or more, more preferably 97.0 anion % or more, further preferably 98.0 anion % or more, further preferably 99.0 anion % or more, further preferably 99.5 anion % or more, further preferably 100 anion %.

[0108] As O 2- Anion components other than F - 、Cl - Br - and I - However, F - 、Cl - Br - and I - The volatilization of these components may cause changes in the physical properties of the glass, reduce the homogeneity of the glass, or significantly increase the consumption of the melting equipment. - 、Cl - Br - and I - The total content of the anion content is 100% minus the amount of O 2- The amount of content.

[0109] <Glass Properties>

[0110] (refractive index nd, Abbe number νd)

[0111] The optical glass is a high-refractive-index, low-dispersion glass having a refractive index nd in the range of 1.9000 to 2.1500 and an Abbe number νd in the range of 20.0 to 35.0. From the perspective of usefulness as a material for optical elements, the preferred ranges of the refractive index nd and the Abbe number νd are as follows.

[0112] The refractive index nd is 1.9000 or higher, preferably 1.9500 or higher, more preferably 1.9600 or higher, further preferably 1.9700 or higher, further preferably 1.9800 or higher, further preferably 1.9850 or higher, further preferably 1.9900 or higher, further preferably 1.9950 or higher, further preferably 2.0000 or higher. Furthermore, the refractive index nd is 2.1500 or lower, preferably 2.1000 or lower, more preferably 2.0500 or lower, further preferably 2.0300 or lower, further preferably 2.0100 or lower, further preferably 2.0020 or lower.

[0113] The Abbe number νd is a value indicating a property related to dispersion and is expressed as νd = (nd-1) / (nF-nC) using the refractive indices nd, nF, and nC for d-rays, F-rays, and C-rays, respectively. The Abbe number is 35.0 or less, preferably 34.0 or less, more preferably 33.0 or less, even more preferably 32.0 or less, even more preferably 31.0 or less, even more preferably 30.5 or less, even more preferably 30.0 or less, and even more preferably 29.5 or less. Furthermore, the Abbe number νd is 20.0 or greater, preferably 21.0 or greater, more preferably 22.0 or greater, even more preferably 23.0 or greater, even more preferably 24.0 or greater, even more preferably 25.0 or greater, even more preferably 26.0 or greater, even more preferably 27.0 or greater, even more preferably 27.5 or greater, even more preferably 28.0 or greater, and even more preferably 28.3 or greater.

[0114] In addition, it is preferable that the refractive index nd and the Abbe number νd satisfy one or more of the following relationship expressions.

[0115] nd≥2.3700-0.0140×νd

[0116] nd≥2.1450-0.0070×νd

[0117] nd≥2.3900-0.0140×νd

[0118] nd≥2.1510-0.0070×νd

[0119] nd≥2.3960-0.0140×νd

[0120] nd≥2.1550-0.0070×νd

[0121] nd≥2.4000-0.0140×νd

[0122] nd≥2.1600-0.0070×νd

[0123] nd≥2.1700-0.0070×νd

[0124] nd≥2.0715-0.0380×νd

[0125] nd≥2.0915-0.0380×νd

[0126] nd≥2.1015-0.0380×νd

[0127] nd≤2.4900-0.0140×νd

[0128] nd≤2.4500-0.0140×νd

[0129] nd≤2.4300-0.0140×νd

[0130] nd≤2.4200-0.0140×νd

[0131] In the present invention and this specification, unless otherwise specified, "refractive index" means "refractive index nd" and "Abbe number" means "Abbe number νd".

[0132] (Partial dispersion characteristics Pg,F)

[0133] From the viewpoint of chromatic aberration correction, the optical glass is preferably a glass having a small relative partial dispersion when the Abbe number νd is fixed.

[0134] Here, the relative partial dispersion Pg,F can be expressed as (ng-nF) / (nF-nc) using the refractive indices ng, nF, and nc for g-rays, F-rays, and c-rays, respectively.

[0135] From the viewpoint of providing a high-refractive-index, low-dispersion glass suitable for high-order chromatic aberration correction, the preferred range of the relative partial dispersion Pg,F of the optical glass is as follows.

[0136] The relative partial dispersion Pg,F is preferably 0.6500 or less, more preferably 0.6300 or less, even more preferably 0.6200 or less, even more preferably 0.6100 or less, and even more preferably 0.6000 or less. Furthermore, the relative partial dispersion Pg,F is preferably 0.5700 or greater, more preferably 0.5800 or greater, even more preferably 0.5820 or greater, even more preferably 0.5850 or greater, and even more preferably 0.590 or greater.

[0137] (Liquid phase temperature LT)

[0138] From the perspective of suppressing crystallization during glass production, the liquidus temperature (LT) of the optical glass is preferably 1400°C or lower, more preferably 1380°C or lower, even more preferably 1360°C or lower, even more preferably 1340°C or lower, even more preferably 1320°C or lower, even more preferably 1310°C or lower, even more preferably 1300°C or lower, even more preferably 1290°C or lower, even more preferably 1280°C or lower, even more preferably 1270°C or lower, and even more preferably 1260°C or lower. The liquidus temperature (LT) may be, for example, 1150°C or higher. A lower liquidus temperature is preferred, and therefore, the liquidus temperature may be less than 1150°C, and there is no particular lower limit.

[0139] (Glass transition temperature Tg)

[0140] The glass transition temperature (Tg) of the optical glass is not particularly limited, but is preferably 630°C or higher from the perspective of machinability. A glass transition temperature of 630°C or higher can reduce the risk of breakage during mechanical processing such as cutting, grinding, polishing, and the like. From the perspective of machinability, the glass transition temperature (Tg) is preferably 640°C or higher, more preferably 700°C or higher, even more preferably 710°C or higher, even more preferably 720°C or lower, even more preferably 730°C or higher, even more preferably 740°C or higher, and even more preferably 745°C or higher. On the other hand, from the perspective of reducing the burden on annealing furnaces and forming molds, the glass transition temperature (Tg) is preferably 800°C or lower, more preferably 790°C or lower, even more preferably 780°C or lower, even more preferably 775°C or lower, even more preferably 770°C or lower, even more preferably 765°C or lower, and even more preferably 760°C or lower.

[0141] (Specific gravity, specific gravity / nd)

[0142] In optical elements (lenses) that make up an optical system, refractive power is determined by the refractive index of the glass forming the lens and the curvature of the lens's optically functional surface (the surface through which light enters and exits). Increasing the curvature of the optically functional surface requires increasing the thickness of the lens, which results in a heavier lens. In contrast, using glass with a high refractive index allows for greater refractive power without increasing the curvature of the optically functional surface.

[0143] It can be seen that if the refractive index can be increased while suppressing the increase in the specific gravity of the glass, it is possible to achieve a lightweight optical element with a certain refractive power.

[0144] From the above viewpoints, the specific gravity of the optical glass is preferably 5.40 or less, more preferably 5.35 or less, further preferably 5.30 or less, even more preferably 5.25 or less, even more preferably 5.20 or less, even more preferably 5.15 or less, even more preferably 5.10 or less, even more preferably 5.05 or less, even more preferably 5.00 or less. The lower the specific gravity, the more preferred it is from the viewpoint of lightweighting of optical elements. Therefore, there is no particular limitation on the lower limit of the specific gravity of the optical glass. In one embodiment, the specific gravity of the optical glass can be, for example, 4.30 or more, 4.40 or more, 4.50 or more, 4.60 or more, 4.70 or more, 4.75 or more, 4.77 or more, 4.80 or more, or 4.85 or more.

[0145] In addition, from the same viewpoint, the value (specific gravity / nd) obtained by dividing the specific gravity of the above-mentioned optical glass by the refractive index nd is preferably 2.80 or less, more preferably 2.70 or less, further preferably 2.65 or less, more preferably 2.60 or less, more preferably 2.56 or less, more preferably 2.54 or less, more preferably 2.52 or less, more preferably 2.51 or less, and more preferably 2.50 or less. The smaller the value of "specific gravity / nd", the more preferred it is from the viewpoint of lightweighting of optical elements. Therefore, the lower limit of the value of "specific gravity / nd" of the above-mentioned optical glass is not particularly limited. In one embodiment, the "specific gravity / nd" of the above-mentioned optical glass can be, for example, 2.20 or more, 2.30 or more, 2.35 or more, 2.36 or more, 2.37 or more, 2.38 or more, 2.39 or more, 2.40 or more, 2.41 or more, 2.42 or more, or 2.43 or more.

[0146] (coloring degree λ5, λ70)

[0147] The light transmittance of glass can be evaluated based on the coloration degree λ5, specifically, the suppression of the long wavelength of the light absorption end on the short wavelength side. The coloration degree λ5 refers to the wavelength at which the spectral transmittance (including surface reflection loss) of glass with a thickness of 10 mm reaches 5% from the ultraviolet region to the visible region. The λ5 shown in the examples described below is the value obtained by measuring in the wavelength range of 250 to 700 nm. More specifically, the spectral transmittance refers to the spectral transmittance obtained by, for example, using a glass sample with parallel planes polished to a thickness of 10.0±0.1 mm, and incident light from a vertical direction on the polished surface, that is, when the intensity of light incident on the glass sample is set to Iin and the intensity of light after passing through the glass sample is set to Iout / Iin.

[0148] The absorption end on the short wavelength side of the spectral transmittance can be quantitatively evaluated based on the coloring degree λ5. When bonding lenses to each other with a UV-curing adhesive to produce a bonded lens, the following operation can be performed: the adhesive is irradiated with UV light through an optical element to cure the adhesive. From the perspective of efficiently curing the UV-curing adhesive, the absorption end on the short wavelength side of the spectral transmittance is preferably within a short wavelength region. The coloring degree λ5 can be used as an indicator for quantitatively evaluating the absorption end on the short wavelength side. The above-mentioned optical glass can exhibit a λ5 of preferably 400 nm or less, more preferably 390 nm or less, further preferably 385 nm or less, preferably 380 nm or less, further preferably 378 nm or less, further preferably 376 nm or less, further preferably 374 nm or less, further preferably 372 nm or less, and further preferably 370 nm or less. The lower the λ5, the better, and its lower limit is not particularly limited. In one embodiment, the λ5 of the optical glass may be greater than or equal to 330 nm, greater than or equal to 340 nm, greater than or equal to 345 nm, greater than or equal to 350 nm, greater than or equal to 355 nm, greater than or equal to 356 nm, greater than or equal to 357 nm, greater than or equal to 358 nm, greater than or equal to 359 nm, greater than or equal to 360 nm, greater than or equal to 361 nm, greater than or equal to 362 nm, or greater than or equal to 363 nm.

[0149] On the other hand, as an indicator of the degree of coloration of the glass, the degree of coloration λ70 can also be cited. λ70 represents the wavelength at which the spectral transmittance reaches 70% as measured by the method described for λ5. From the perspective of producing glass with less coloration, λ70 is preferably 500 nm or less, more preferably 490 nm or less, further preferably 480 nm or less, more preferably 470 nm or less, further preferably 460 nm or less, further preferably 457 nm or less, further preferably 455 nm or less, further preferably 450 nm or less, further preferably 445 nm or less, further preferably 440 nm or less. The lower the λ70, the better, and its lower limit is not particularly limited. In one embodiment, the λ70 of the above-mentioned optical glass can be 370 nm or more, 380 nm or more, 390 nm or more, 400 nm or more, 410 nm or more, 420 nm or more, 425 nm or more, 430 nm or more, or 435 nm or more.

[0150] (λ5 / nd, λ5 / νd, λ70 / nd, λ70 / νd)

[0151] Regarding the degree of coloration, it is preferable to suppress the increase in the degree of coloration of the glass and to increase the refractive index. In addition, it is also preferable to suppress the increase in the degree of coloration of the glass and to reduce the dispersion.

[0152] From the above viewpoints, the value obtained by dividing the λ5 of the optical glass by the refractive index nd (λ5 / nd) is preferably 195.00 nm or less, more preferably 190.00 nm or less, even more preferably 188.00 nm or less, even more preferably 187.50 nm or less, even more preferably 187.00 nm or less, even more preferably 186.50 nm or less, even more preferably 186.00 nm or less, even more preferably 185.55 nm or less, even more preferably 185.00 nm or less. The lower the λ5 / nd, the more preferred it is, and its lower limit is not particularly limited. In one embodiment, the λ5 / nd of the optical glass may be 160.00 nm or more, 170.00 nm or more, 171.00 nm or more, 172.00 nm or more, 173.00 nm or more, 174.00 nm or more, 175.00 nm or more, 176.00 nm or more, 177.00 nm or more, or 178.00 nm or more.

[0153] The value (λ5 / νd) obtained by dividing the λ5 of the above-mentioned optical glass by the Abbe number νd is preferably 20.00nm or less, more preferably 15.00nm or less, further preferably 14.00nm or less, further preferably 13.00nm or less, further preferably 12.90nm or less, further preferably 12.80nm or less, and further preferably 12.70nm or less. In addition, the lower the λ5 / νd, the more preferred it is, and its lower limit is not particularly limited. In one embodiment, the λ5 / νd of the above-mentioned optical glass can be 8.00nm or more, 8.50nm or more, 9.00nm or more, 9.50nm or more, 10.00nm or more, 10.50nm or more, 11.00nm or more, 11.50nm or more, 11.70nm or more, 12.00nm or more, 12.10nm or more, 12.20nm or more, 12.30nm or more, 12.40nm or more, or 12.50nm or more.

[0154] The value (λ70 / nd) obtained by dividing the λ70 of the above-mentioned optical glass by the refractive index nd is preferably 270.00nm or less, more preferably 260.00nm or less, further preferably 250.00nm or less, further preferably 240.00nm or less, further preferably 235.00nm or less, further preferably 230.00nm or less, further preferably 227.00nm or less, and further preferably 225.00nm or less. In addition, the lower the λ70 / nd, the more preferred it is, and its lower limit is not particularly limited. In one embodiment, the λ70 / nd of the above-mentioned optical glass can be 190.00nm or more, 200.00nm or more, 205.00nm or more, 210.00nm or more, 212.00nm or more, 214.00nm or more, 216.00nm or more, 218.00nm or more, or 220.00nm or more.

[0155] The value obtained by dividing the λ70 of the above-mentioned optical glass by the Abbe number νd (λ70 / νd) is preferably 25.00 nm or less, more preferably 22.00 nm or less, further preferably 20.00 nm or less, further preferably 19.00 nm or less, further preferably 18.00 nm or less, further preferably 17.00 nm or less, and further preferably 16.00 nm or less. In addition, the lower the λ70 / νd, the more preferred it is, and its lower limit is not particularly limited. In one embodiment, the λ70 / νd of the above-mentioned optical glass can be 8.00 nm or more, 9.00 nm or more, 10.00 nm or more, 11.00 nm or more, 12.00 nm or more, 13.00 nm or more, 14.00 nm or more, or 15.00 nm or more.

[0156] <Glass Manufacturing Method>

[0157] The optical glass can be obtained by, for example, mixing, melting, and forming glass raw materials in a manner to obtain the desired properties. Examples of the glass raw materials include phosphates, fluorides, alkali metal compounds, and alkaline earth metal compounds. The glass can be melted and formed using known methods.

[0158] [Glass material for press molding, optical element blank, and method for producing the same]

[0159] Another embodiment of the present invention relates to:

[0160] A glass material for press molding formed from the above optical glass; and

[0161] An optical element blank formed from the above optical glass.

[0162] According to another embodiment of the present invention, there is further provided:

[0163] A method for producing a glass material for press molding, comprising the step of molding the optical glass into a glass material for press molding;

[0164] a method for producing an optical element blank comprising the step of press-molding the press-molding glass material using a press-molding die to produce an optical element blank; and

[0165] A method for producing an optical element blank comprising the step of forming the optical glass into an optical element blank.

[0166] An optical element blank is an optical element base material that has a shape similar to that of the target optical element and to which a polishing material (a surface layer that is removed by polishing) and, as needed, a grinding material (a surface layer that is removed by grinding) are added. The optical element is finely processed by grinding and polishing the surface of the optical element blank. In one embodiment, the optical element blank can be produced by pressurizing molten glass obtained by melting an appropriate amount of the above-mentioned optical glass (referred to as a direct press method). In another embodiment, the optical element blank can also be produced by solidifying the molten glass obtained by melting an appropriate amount of the above-mentioned glass.

[0167] In another embodiment, an optical element blank can be produced by preparing a glass material for press molding and press molding the prepared glass material for press molding.

[0168] The press-molding of the glass raw material for press molding can be performed by a known method of press-molding the heated and softened glass raw material using a press-molding mold. Both heating and press-molding can be performed in the atmosphere. Annealing after press molding reduces strain within the glass, thereby producing a homogeneous optical element blank.

[0169] Press-molding glass materials include materials that are directly supplied to the press-molding process for producing optical element blanks in their original form, known as press-molding glass gobs, and materials that are subjected to mechanical processing such as cutting, grinding, and polishing and then passed through press-molding glass gobs before being press-molded. Cutting methods include methods such as creating grooves in the desired cut area on the surface of a glass sheet using a process called scribing, applying localized pressure to the grooved area from the back of the grooved surface, and cutting the glass sheet at the grooved area; and methods such as cutting the glass sheet with a cutter. Grinding and polishing methods also include barrel polishing.

[0170] Glass raw materials for press forming can be produced, for example, by casting molten glass into a mold, forming a glass sheet, and then cutting the glass sheet into multiple glass sheets. Alternatively, a suitable amount of molten glass can be formed into press forming glass gobs. Optical element blanks can also be produced by reheating and softening the press forming glass gobs, and then press forming them. This method of reheating, softening, and press forming the glass to produce optical element blanks is known as the reheat press method, as opposed to the direct press method.

[0171] [Optical element and method of manufacturing the same]

[0172] Another embodiment of the present invention relates to:

[0173] An optical element formed from the above optical glass.

[0174] The optical element is made of the optical glass. In the optical element, one or more coating layers such as a multilayer film such as an antireflection film may be formed on the glass surface.

[0175] In addition, according to one embodiment of the present invention, it is also possible to provide:

[0176] A method for producing an optical element includes the step of producing an optical element by grinding and / or polishing the optical element blank.

[0177] In the above-mentioned method for manufacturing an optical element, grinding and polishing can be performed using known methods. By thoroughly cleaning and drying the surface of the optical element after processing, an optical element with high internal and surface quality can be obtained. This results in an optical element formed from the above-mentioned optical glass. Examples of optical elements include various lenses such as spherical lenses, aspherical lenses, and microlenses, as well as prisms.

[0178] In addition, the optical element formed by the above-mentioned optical glass is also suitable for use as a lens constituting a bonded optical element. As a bonded optical element, an element formed by bonding lenses to each other (bonded lens), an element formed by bonding a lens to a prism, etc. can be exemplified. For example, a bonded optical element can be made by the following method: the bonding surfaces of the two optical elements to be bonded are precisely processed in such a way that their shapes become inverted shapes (for example, spherical polishing), and an ultraviolet curing adhesive for bonding the bonding lenses is applied, and after they are bonded, ultraviolet rays are irradiated through the lenses to cure the adhesive, thereby making a bonded optical element. As an optical element material for making a bonded optical element in this way, the above-mentioned optical glass is preferred. A plurality of optical glasses with different Abbe numbers νd can be used to respectively make a plurality of optical elements to be bonded, and mechanically bonded, thereby making an element suitable for correcting chromatic aberration.

[0179] The results of quantitative analysis of glass composition may express the glass components on an oxide basis, and express the content of the glass components as mass %. Such a composition expressed as mass % on an oxide basis can be converted into a composition expressed as cation % and anion % by, for example, the following method.

[0180] When the glass contains N glass components, the kth glass component is represented by A(k) m O n . Wherein, k is any integer greater than 1 and less than N.

[0181] A(k) is a cation, O is oxygen, and m and n are integers that can be determined stoichiometrically. For example, in the case of B2O3 based on an oxide standard, m=2 and n=3, and in the case of SiO2, m=1 and n=2.

[0182] Next, A(k) m O n The content of A(k) is X(k) [mass %]. Here, when the atomic weight of A(k) is P(k) and the atomic number of oxygen O is Q, A(k) m O n The formal molecular weight R(k) is R(k)=P(k)×m+Q×n.

[0183] Furthermore, when B=100 / {Σ[m×X(k) / R(k)]}, the cationic component A(k) s+ The content (cation %) is [X(k) / R(k)]×m×B(cation %). Here, Σ represents the sum of m×X(k) / R(K) for k=1 to N. m varies depending on k. s is 2n / m.

[0184] The molecular weight R(k) can be calculated by rounding off to the fourth decimal place and using the value expressed to the third decimal place. The molecular weights of several glass components and additives expressed based on oxides are shown in Table 1 below.

[0185] [Table 1]

[0186] oxides Molecular weight oxides Molecular weight <![CDATA[B2O3]]> 69.621 <![CDATA[Cs2O]]> 281.810 <![CDATA[SiO2]]> 60.084 ZnO 81.389 <![CDATA[La2O3]]> 325.809 MgO 40.304 <![CDATA[Y2O3]]> 225.810 CaO 56.077 <![CDATA[Gd2O3]]> 362.498 SrO 81.389 <![CDATA[Yb2O3]]> 394.084 BaO 153.326 <![CDATA[Nb2O5]]> 265.810 <![CDATA[Al2O3]]> 101.961 <![CDATA[TiO2]]> 79.882 <![CDATA[Ga2O3]]> 187.444 <![CDATA[WO3]]> 231.839 <![CDATA[In2O3]]> 277.634 <![CDATA[Ta2O5]]> 441.893 <![CDATA[Sc2O3]]> 137.910 <![CDATA[Bi2O3]]> 465.959 <![CDATA[HfO2]]> 210.489 <![CDATA[ZrO2]]> 123.223 <![CDATA[Lu2O3]]> 397.932 <![CDATA[Li2O]]> 29.882 <![CDATA[GeO2]]> 104.629 <![CDATA[Na2O]]> 61.979 <![CDATA[P2O5]]> 141.945 <![CDATA[K2O]]> 94.196 <![CDATA[TeO2]]> 159.599 <![CDATA[Rb2O]]> 186.935 <![CDATA[Sb2O3]]> 291.518

[0187] Example

[0188] Hereinafter, the present invention will be described in more detail with reference to the examples. However, the present invention is not limited to the embodiments shown in the examples.

[0189] <Example 1>

[0190] In order to obtain the glass composition shown in the table below, corresponding nitrates, sulfates, carbonates, hydroxides, oxides, boric acid, etc. were used as raw materials for introducing each component, and the raw materials were weighed and thoroughly mixed to prepare a mixed raw material.

[0191] The prepared raw materials were placed in a platinum crucible, heated, and melted. After melting, the molten glass was poured into a mold, naturally cooled to near the glass transition temperature, and immediately placed in an annealing furnace. After annealing treatment within the glass transition temperature range for about 1 hour, the molten glass was naturally cooled to room temperature in the furnace, thereby obtaining the optical glasses (oxide glasses) shown in Table 1.

[0192] Regarding the anion components of each optical glass shown in the following table, 2- The content is 100% anion.

[0193] When the obtained optical glass was observed under an optical microscope, no crystal precipitation, foreign matter such as platinum particles, bubbles, or streaks were observed.

[0194] Various physical properties of the optical glass obtained in this manner are shown in the table below.

[0195] Various physical properties of the optical glass were measured by the methods shown below.

[0196] <Evaluation of optical glass properties>

[0197] (1) Refractive index nd, ng, nF, nC and Abbe number νd

[0198] The glass obtained by cooling at a cooling rate of -30°C / hour was measured for refractive index nd, ng, nF, nC, and Abbe number νd by the refractive index measurement method of the Japan Optical Glass Industries Association.

[0199] (2) Relative partial dispersion Pg,F

[0200] The relative partial dispersion Pg,F was calculated from the refractive indices ng, nF, and nC obtained in (1) above.

[0201] (3) Glass transition temperature Tg

[0202] The glass transition temperature Tg was measured using a differential scanning calorimeter (DSC3300) manufactured by NETZSCH Co., Ltd. at a heating rate of 10° C. / min.

[0203] (4) Liquidus temperature LT

[0204] Glass samples (volume: 10 cm 3 ) is placed in a platinum crucible and held in a glass melting furnace set at 1400°C for 20 minutes. After the glass sample is fully melted and molten, the platinum crucible is removed from the glass melting furnace and the glass sample is allowed to cool in the crucible until the temperature of the glass sample reaches below 500°C. The platinum crucible is then placed in a glass melting furnace set at a temperature of T°C and held for 2 hours. After being removed from the furnace, the platinum crucible containing the glass sample is immediately (within 8 seconds) placed on a room temperature refractory material (brick, etc.) to cool the glass sample to room temperature. Room temperature here is a temperature in the range of -10 to 80°C. The surface and interior of the glass sample are then visually observed to confirm the presence of crystals. The above experiment is repeated while varying the temperature T°C in increments of 10°C within the range of 1100 to 1350°C. The lowest temperature at which no crystals are observed on the surface or inside of the glass sample is defined as the liquidus temperature LT.

[0205] (5) Specific gravity, specific gravity / nd

[0206] The specific gravity was measured by the Archimedes method.

[0207] The value (specific gravity / nd) obtained by dividing the measured specific gravity by the refractive index nd determined in the above (1) was calculated.

[0208] (6) Coloring degree λ5, λ70

[0209] A glass sample with a thickness of 10±0.1 mm and two optically polished flat surfaces facing each other was used. A spectrophotometer was used to measure the intensity Iout of light after it passed through the glass sample, with light of intensity Iin incident from a direction perpendicular to the polished surface. The spectral transmittance Iout / Iin was calculated, and the wavelength at which the spectral transmittance reached 5% was set to λ5, and the wavelength at which the spectral transmittance reached 70% was set to λ70.

[0210] (7)λ5 / nd, λ5 / νd, λ70 / nd, λ70 / νd

[0211] Based on nd, νd, λ5 and λ70 obtained above, λ5 / nd, λ5 / νd, λ70 / nd and λ70 / νd are calculated.

[0212] The above results are shown in the following Table 2 (Tables 2-1 to 2-6).

[0213] [Table 2-1]

[0214] cation% No.1 No.2 No.3 No.4 <![CDATA[B 3+ ]]> 19.72 19.73 21.72 19.72 <![CDATA[La 3+ ]]> 29.80 29.80 29.80 29.80 <![CDATA[Si 4+ ]]> 11.39 11.40 11.40 13.40 <![CDATA[Zn 2+ ]]> 2.32 2.29 0.32 0.32 <![CDATA[Ti 4+ ]]> 17.31 20.32 23.60 23.60 <![CDATA[Zr 4+ ]]> 4.92 4.92 4.92 4.92 <![CDATA[Gd 3+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Nb 5+ ]]> 6.29 3.29 0.00 0.00 <![CDATA[W 6+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Y 3+ ]]> 8.24 8.24 8.24 8.24 <![CDATA[Ca 2+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Ba 2+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Ta 5+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Sb 3+ ]]> 0.00 0.00 0.00 0.00 Total 100.00 100.00 100.00 100.00 <![CDATA[Si 4+ +B 3+ ]]> 31.11 31.13 33.12 33.12 <![CDATA[B 3+ / (Si 4+ +B 3+ )]]> 0.63 0.63 0.66 0.60 <![CDATA[Nb 5+ +W 6+ ]]> 6.29 3.29 0.00 0.00 <![CDATA[Ti 4+ + Nb 5+ +W 6+ + Bi 3+ ]]> 23.60 23.61 23.60 23.60 <![CDATA[Ti 4+ / (Of 4+ +Nb 5+ +W 6+ +Like 3+ )]]> 0.73 0.86 1.00 1.00 <![CDATA[Gd 3+ +Nb 5+ +W 6+ ]]> 6.29 3.29 0.00 0.00 <![CDATA[La 3+ +Gd 3+ +Y 3+ ]]> 38.04 38.04 38.04 38.04 <![CDATA[(Si 4+ +B 3+ ) / (The 3+ +Gd 3+ +Y 3+ )]]> 0.82 0.82 0.87 0.87 <![CDATA[(Si 4+ +B 3+ ) / (Of 4+ +Nb 5+ +W 6+ +Like 3+ )]]> 1.32 1.32 1.40 1.40 <![CDATA[(La 3+ +GD 3+ +Y 3+ ) / (Ti 4+ +Nb 5+ +W 6+ + Ball 3+ )]]> 1.61 1.61 1.61 1.61 <![CDATA[Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ]]> 2.32 2.29 0.32 0.32 <![CDATA[(Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) / (The 3+ +Y 3+ )]]> 0.061 0.060 0.008 0.009 <![CDATA[Zn 2+ / (The 3+ +Y 3+ )]]> 0.061 0.060 0.008 0.009 <![CDATA[(Zn 2+ +They 2+ ) / La 3+ ]]> 0.078 0.077 0.011 0.011 <![CDATA[(Zn 2+ +Ba 2+ ) / (The 3+ +Y 3+ )]]> 0.061 0.060 0.008 0.009 <![CDATA[(Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) / (S 4+ i+B 3+ )]]> 0.075 0.074 0.010 0.010 <![CDATA[(Gd 3+ +Nb 5+ +W 6+ ) / (Si 4+ +B 3+ +Zn 2+ +La 3+ +Y 3+ +Zr 4+ +Ti 4+ )]]> 0.067 0.034 0.000 0.000 <![CDATA[Gd 3++ +W 6+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[(Gd 3++ +W 6+ ) / (Si 4+ +B 3+ +Zn 2+ +La 3+ +Y 3+ +Zr 4+ +Ti 4+ )]]> 0.000 0.000 0.000 0.000 nd 2.00378 2.00494 2.00035 1.99618 vd 29.01 28.78 28.52 28.67 Pg.F 0.599 0.603 0.607 0.608 Liquidus temperature LT(℃) 1240 1260 1270 1270 proportion 5.02 4.99 4.91 4.89 Specific gravity / nd 2.51 2.49 2.45 2.45 λ70(nm) 451 452 455 453 λ5(nm) 364 365 370 370 λ70 / nd(nm) 225.07 225.44 227.46 226.93 λ5 / nd(nm) 181.66 182.05 184.97 185.35 λ70 / vd(nm) 15.55 15.71 15.95 15.80 λ5 / vd(nm) 12.55 12.68 12.97 12.91 Glass transition temperature Tg(℃) 747 751 759 762

[0215] [Table 2-2]

[0216] cation% No.5 No.6 No.7 No.8 <![CDATA[B 3+ ]]> 19.72 20.72 21.71 21.72 <![CDATA[La 3+ ]]> 29.80 29.02 28.25 31.80 <![CDATA[Si 4+ ]]> 11.39 11.40 11.40 11.40 <![CDATA[Zn 2+ ]]> 2.32 2.32 2.32 0.31 <![CDATA[Ti 4+ ]]> 22.31 23.60 23.60 23.60 <![CDATA[Zr4 + ]]> 4.92 4.92 4.92 4.92 <![CDATA[Gd 3+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Nb 5+ ]]> 1.29 0.00 0.00 0.00 <![CDATA[W 6+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Y 3+ ]]> 8.24 8.02 7.80 6.24 <![CDATA[Ca 2+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Ba 2+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Ta 5+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Sb a+ ]]> 0.00 0.00 0.00 0.00 Total 100.00 100.00 100.00 100.00 <![CDATA[Si 4+ +B 3+ ]]> 31.11 32.12 33.11 33.12 <![CDATA[B 3+ / (Si 4+ +B 3+ )]]> 0.63 0.64 0.66 0.66 <![CDATA[Nb 5+ +W 6+ ]]> 1.29 0.00 0.00 0.00 <![CDATA[Ti 4+ + Nb 5+ +W 6+ + Bi 3+ ]]> 23.60 23.60 23.60 23.60 <![CDATA[Ti 4+ / (Of 4+ +Nb 5+ +W 6+ +Like 3+ )]]> 0.95 1.00 1.00 1.00 <![CDATA[Gd 3+ +Nb 5+ +W 6+ ]]> 1.29 0.00 0.00 0.00 <![CDATA[La 3+ +Gd a+ +Y 3+ ]]> 38.04 37.04 36.05 38.04 <![CDATA[(Si 4+ +B 3+ ) / (The 3+ +Gd 3+ +Y 3+ )]]> 0.82 0.87 0.92 0.87 <![CDATA[(Si 4+ +B 3+ ) / (Of 4+ +Nb 5+ +W 6+ +Like 3+ )]]> 1.32 1.36 1.40 1.40 <![CDATA[(La 3+ +GD 3+ +Y 3+ ) / (Ti 4+ +Nb 5+ +W 6+ + Ball 3+ )]]> 1.61 1.57 1.53 1.61 <![CDATA[Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ]]> 2.32 2.32 2.32 0.31 <![CDATA[(Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) / (The 3+ +Y 3+ )]]> 0.061 0.063 0.064 0.008 <![CDATA[Zn 2+ / (The 3+ +Y 3+ )]]> 0.061 0.063 0.064 0.008 <![CDATA[(Zn 2+ +They 2+ ) / La 3+ ]]> 0.078 0.080 0.082 0.010 <![CDATA[(Zn 2+ +Ba 2+ ) / (The 3+ +Y 3+ )]]> 0.061 0.063 0.064 0.008 <![CDATA[(Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) / (S 4+ i+B 3+ )]]> 0.075 0.072 0.070 0.009 <![CDATA[(Gd 3+ +Nb 5+ +W 6+ ) / (Si 4+ +B 3+ +Zn 2+ +La 3+ +Y 3+ +Zr 4+ +Ti 4+ )]]> 0.013 0.000 0.000 0.000 <![CDATA[Gd 3++ +W 6+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[(Gd 3++ +W 6+ ) / (Si 4+ +B 3+ +Zn 2+ +La 3+ +Y 3+ +Zr 4+ +Ti 4+ )]]> 0.000 0.000 0.000 0.000 nd 2.00557 2.00288 200008 2.00221 vd 28.62 28.27 28.23 28.47 Pg.F 0.607 0.602 0.604 0.600 Liquidus temperature LT(℃) 1300 1280 1260 1300 proportion 4.97 4.92 4.88 4.94 Specific gravity / nd 2.48 2.46 2.44 2.47 λ70(nm) 444 454 459 451 λ5(nm) 366 368 370 368 λ70 / nd(nm) 221.38 226.67 229.49 225.25 λ5 / nd(nm) 182.49 183.74 184.99 183.80 λ70 / vd(nm) 15.51 16.06 16.26 15.84 λ5 / vd(nm) 12.79 13.02 13.11 12.93 Glass transition temperature Tg(℃) 753 748 742 758

[0217] [Table 2-3]

[0218] cation% No.9 No.10 No.11 No.12 <![CDATA[B 3+ ]]> 21.72 19.71 20.71 20.72 <![CDATA[La 3+ ]]> 27.80 25.80 27.80 28.02 <![CDATA[Si 4+ ]]> 11.40 11.41 11.40 11.39 <![CDATA[Zn 2+ ]]> 0.32 2.32 1.32 2.32 <![CDATA[Ti 4+ ]]> 23.60 23.60 23.60 23.60 <![CDATA[Zr 4+ ]]> 4.92 4.92 4.92 4.92 <![CDATA[Gd 3+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Nb 5+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[W 6+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Y 3+ ]]> 10.24 12.24 10.24 9.02 <![CDATA[Ca 2+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Ba 2+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Ta 5+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Sb 3+ ]]> 0.00 0.00 0.00 0.00 Total 100.00 100.00 100.00 100.00 <![CDATA[Si 4+ +B 3+ ]]> 33.12 31.12 32.12 32.12 <![CDATA[B 3+ / (Si 4+ +B 3+ )]]> 0.66 0.63 0.64 0.65 <![CDATA[Nb 5+ +W 6+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Ti 4+ + Nb 5+ +W 6+ + Bi 3+ ]]> 23.60 23.60 23.60 23.60 <![CDATA[Ti 4+ / (Of 4+ +Nb 5+ +W 6+ +Like 3+ )]]> 1.00 1.00 1.00 1.00 <![CDATA[Gd 3+ +Nb 5+ +W 6+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[La 3+ +Gd 3+ +Y 3+ ]]> 38.04 38.04 38.04 37.04 <![CDATA[(Si 4+ +B 3+ ) / (The 3+ +Gd 3+ +Y 3+ )]]> 0.87 0.82 0.84 0.87 <![CDATA[(Si 4+ +B 3+ ) / (Of 4+ +Nb 5+ +W 6+ +Like 3+ )]]> 1.40 1.32 1.36 1.36 <![CDATA[(La 3+ +GD 3+ +Y 3+ ) / (Ti 4+ +Nb 5+ +W 6+ + Ball 3+ )]]> 1.61 1.61 1.61 1.57 <![CDATA[Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ]]> 0.32 2.32 1.32 2.32 <![CDATA[(Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) / (The 3+ +Y 3+ )]]> 0.008 0.061 0.035 0.063 <![CDATA[Zn 2+ / (The 3+ +Y 3+ )]]> 0.008 0.061 0.035 0.063 <![CDATA[(Zn 2+ +They 2+ ) / La 3+ ]]> 0.012 0.090 0.048 0.083 <![CDATA[(Zn 2+ +Ba 2+ ) / (The 3+ +Y 3+ )]]> 0.008 0.061 0.035 0.063 <![CDATA[(Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) / (S 4+ i+B 3+ )]]> 0.010 0.075 0.041 0.072 <![CDATA[(Gd 3+ +Nb 5+ +W 6+ ) / (Si 4+ +B 3+ +Zn 2+ +La 3+ +Y 3+ +Zr 4+ +Ti 4+ )]]> 0.000 0.000 0.000 0.000 <![CDATA[Gd 3++ +W 6+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[(Gd 3++ +W 6+ ) / (Si 4+ +B 3+ +Zn 2+ +La 3+ +Y 3+ +Zr 4+ +Ti 4+ )]]> 0.000 0.000 0.000 0.000 nd 1.99911 2.00161 2.00161 2.00236 vd 28.48 28.45 28.45 28.29 Pg.F 0.607 0.603 0.604 0.604 Liquidus temperature LT(℃) 1250 1340 1280 1270 proportion 4.88 4.89 4.90 4.90 Specific gravity / nd 2.44 2.44 2.45 2.44 λ70(nm) 452 452 450 460 λ5(nm) 369 368 367 369 λ70 / nd(nm) 226.10 225.82 224.82 229.73 λ5 / nd(nm) 184.58 183.85 183.35 184.28 λ70 / vd(nm) 15.87 15.89 15.82 16.26 λ5 / vd(nm) 12.96 12.93 12.90 13.04 Glass transition temperature Tg(℃) 758 755 756 746

[0219] [Table 2-4]

[0220] cation% No.13 No.14 No.15 No.16 <![CDATA[B 3+ ]]> 20.72 20.73 20.71 20.73 <![CDATA[La 3+ ]]> 27.02 25.02 26.29 25.56 <![CDATA[Si 4+ ]]> 11.40 11.39 11.40 11.39 <![CDATA[Zn 2+ ]]> 2.32 2.32 3.32 4.32 <![CDATA[Ti 4+ ]]> 23.60 23.60 23.60 23.60 <![CDATA[Zi 4+ ]]> 4.92 4.92 4.92 4.92 <![CDATA[Gd 3+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Nb 5+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[W 6+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Y 3+ ]]> 10.02 12.02 9.75 9.48 <![CDATA[Ca 2+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Ba 2+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Ta 5+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Sb 3+ ]]> 0.00 0.00 0.00 0.00 Total 100.00 100.00 100.00 100.00 <![CDATA[Si 4+ B 3+ ]]> 32.12 32.12 32.11 32.12 <![CDATA[B 3+ / (Si 4+ B 3+ )]]> 0.65 0.65 0.65 0.65 <![CDATA[Nb 5+ +W 6+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Ti 4+ + Nb 5+ +W 6+ + Bi 3+ ]]> 23.60 23.60 23.60 23.60 <![CDATA[Ti 4+ / (Of 4+ +Nb 5+ +W 6+ +Like 3+ )]]> 1.00 1.00 1.00 1.00 <![CDATA[Gd 3+ +Nb 5+ +W 6+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[La 3+ +Gd 3+ +Y 3+ ]]> 37.04 37.05 36.04 35.04 <![CDATA[(Si 4+ +B 3+ ) / (The 3+ +Gd 3+ +Y 3+ )]]> 0.87 0.87 0.89 0.92 <![CDATA[(Si 4+ +B 3+ ) / (Of 4+ +Nb 5+ +W 6+ +Like 3+ )]]> 1.36 1.36 1.36 1.36 <![CDATA[(La 3+ +GD 3+ +Y 3+ ) / (Ti 4+ +Nb 5+ +W 6+ + Ball 3+ )]]> 1.57 1.57 1.53 1.48 <![CDATA[Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Mg 2+ +ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ]]> 2.32 2.32 3.32 4.32 <![CDATA[(Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) / (The 3+ +Y 3+ )]]> 0.063 0.063 0.092 0.123 <![CDATA[Zn 2+ / (The 3+ +Y 3+ )]]> 0.063 0.063 0.092 0.123 <![CDATA[(Zn 2+ +They 2+ ) / La 3+ ]]> 0.086 0.093 0.126 0.169 <![CDATA[(Zn 2+ +Ba 2+ ) / (The 3+ +Y 3+ )]]> 0.063 0.063 0.092 0.123 <![CDATA[(Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) / (S 4+ i+B 3+ )]]> 0.072 0.072 0.103 0.135 <![CDATA[(Gd 3+ +Nb 5+ +W 6+ ) / (Si 4+ +B 3+ +Zn 2+ +La 3+ +Y 3+ +Zr 4+ +Ti 4+ )]]> 0.000 0.000 0.000 0.000 <![CDATA[Gd 3++ +W 6+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[(Gd 3++ +W 6+ ) / (Si 4+ +B 3+ +Zn 2+ +La 3+ +Y 3+ +Zr 4+ +Ti 4+ )]]> 0.000 0.000 0.000 0.000 nd 2.00153 2.00004 2.00040 2.00046 vd 28.29 28.28 28.25 28.06 Pg.F 0.601 0.602 0.607 0.604 Liquidus temperature LT(℃) 1280 1330 1290 1320 proportion 4.89 4.86 4.88 4.86 Specific gravity / nd 2.44 2.43 2.44 2.43 λ70(nm) 457 452 455 457 λ5(nm) 370 369 370 370 λ70 / nd(nm) 228.33 226.00 227.45 228.45 λ5 / nd(nm) 184.86 184.50 184.96 184.96 λ70 / vd(nm) 16.15 15.98 16.11 16.29 λ5 / vd(nm) 13.08 13.05 13.10 13.19 Glass transition temperature Tg(℃) 747 747.7 739 729

[0221] [Table 2-5]

[0222] cation% No.17 No.18 No.19 No.20 <![CDATA[B 3+ ]]> 21.72 22.22 23.73 23.73 <![CDATA[La 3+ ]]> 27.02 26.65 27.80 27.80 <![CDATA[Si 4+ ]]> 10.40 10.40 9.40 9.39 <![CDATA[Zn 2+ ]]> 2.32 2.32 0.32 0.32 <![CDATA[Ti 4+ ]]> 23.60 23.60 23.60 23.10 <![CDATA[Zr 4+ ]]> 4.92 4.92 4.92 5.42 <![CDATA[Gd 3+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Nb 5+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[W 6+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Y 3+ ]]> 10.02 9.88 10.24 10.24 <![CDATA[Ca 2+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Ba 2+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Ta 5+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Sb 3+ ]]> 0.00 0.00 0.00 0.00 Total 100.00 100.00 100.00 100.00 <![CDATA[Si 4+ +B 0+ ]]> 32.12 32.62 33.13 33.12 <![CDATA[B 3+ / (Si 4+ +B 3+ )]]> 0.68 0.68 0.72 0.72 <![CDATA[Nb 5+ +W 6+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Ti 4+ + Nb 5+ +W 6+ + Bi 3+ ]]> 23.60 23.60 23.60 23.10 <![CDATA[Ti 4+ / (Of 4+ +Nb 5+ +W 6+ +Like 3+ )]]> 1.00 1.00 1.00 1.00 <![CDATA[Gd 3+ +Nb 5+ +W 6+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[La 3+ +Gd 3+ +Y 3+ ]]> 37.04 36.54 38.04 38.04 <![CDATA[(Si 4+ +B 3+ ) / (The 3+ +Gd 3+ +Y 3+ )]]> 0.87 0.89 0.87 0.87 <![CDATA[(Si 4+ +B 3+ ) / (Of 4+ +Nb 5+ +W 6+ +Like 3+ )]]> 1.36 1.38 1.40 1.43 <![CDATA[(La 3+ +GD 3+ +Y 3+ ) / (Ti 4+ +Nb 5+ +W 6+ + Ball 3+ )]]> 1.57 1.55 1.61 1.65 <![CDATA[Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ]]> 2.32 2.32 0.32 0.32 <![CDATA[(Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) / (The 3+ +Y 3+ )]]> 0.063 0.063 0.008 0.008 <![CDATA[Zn 2+ / (The 3+ +Y 3+ )]]> 0.063 0.063 0.008 0.008 <![CDATA[(Zn 2+ +They 2+ ) / La 3+ ]]> 0.086 0.087 0.011 0.011 <![CDATA[(Zn 2+ +Ba 2+ ) / (The 3+ +Y 3+ )]]> 0.063 0.063 0.008 0.008 <![CDATA[(Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) / (S 4+ i+B 3+ )]]> 0.072 0.071 0.010 0.010 <![CDATA[(Gd 3+ +Nb 5+ +W 6+ ) / (Si 4+ +B 3+ +Zn 2+ +La 3+ +Y 3+ +Zr 4+ You 4) ]]> 0.000 0.000 0.000 0.000 <![CDATA[Gd 3++ +W 6+ ]]> 0.00 0.00 0.00 0.00 <![CDATA[(Gd 3++ +W 6+ ) / (Si 4+ +B 3+ +Zn 2+ +La 3+ +Y 3+ +Zr 4+ +Ti 4+ )]]> 0.000 0.000 0.000 0.000 nd 2.00349 2.00184 2.00329 2.00197 vd 28.28 28.29 28.42 28.57 Pg.F 0.603 0.586 0.608 0.605 Liquidus temperature LT(℃) 1280 1270 1260 1290 proportion 4.90 4.88 4.89 4.90 Specific gravity / nd 2.45 2.44 2.44 2.45 λ70(nm) 454 453 457 455 λ5(nm) 369 369 369 368 λ70 / nd(nm) 226.60 226.29 228.12 227.28 λ5 / nd(nm) 184.18 184.33 184.20 183.82 λ70 / vd(nm) 16.05 16.01 16.08 15.93 λ5 / vd(nm) 13.05 13.04 12.98 12.88 Glass transition temperature Tg(℃) 743 741 752 752

[0223] [Table 2-6]

[0224] cation% No.21 No.22 No.23 <![CDATA[B 3+ ]]> 23.72 26.21 26.21 <![CDATA[La 3+ ]]> 27.80 27.80 27.80 <![CDATA[Si 4+ ]]> 9.40 7.40 7.40 <![CDATA[Zn 2+ ]]> 0.32 0.32 0.32 <![CDATA[Ti 4+ ]]> 22.59 22.10 22.10 <![CDATA[Zr 4+ ]]> 5.92 5.92 5.92 <![CDATA[Gd 3+ ]]> 0.00 0.00 0.00 <![CDATA[Nb 5+ ]]> 0.00 0.00 0.00 <![CDATA[W 8+ ]]> 0.00 0.00 0.00 <![CDATA[Y 3+ ]]> 10.24 10.24 10.24 <![CDATA[Ca 2+ ]]> 0.00 0.00 0.00 <![CDATA[Ba 2+ ]]> 0.00 0.00 0.00 <![CDATA[Ta 5+ ]]> 0.00 0.00 0.00 <![CDATA[Sb 3+ ]]> 0.00 0.00 0.00 Total 100.00 100.00 100.00 <![CDATA[Si 4+ +B 3+ ]]> 33.12 33.61 33.61 <![CDATA[B 3+ / (Si 4+ +B 5+ )]]> 0.72 0.78 0.78 <![CDATA[Nb 5+ +W 6+ ]]> 0.00 0.00 0.00 <![CDATA[Ti 4+ + Nb 5+ +W 6+ + Bi 3+ ]]> 22.59 22.10 22.10 <![CDATA[Ti 4+ / (Of 4+ +NB 5+ +W 6+ +Like 3+ )]]> 1.00 1.00 1.00 <![CDATA[Gd 3+ +Nb 5+ +W 6+ ]]> 0.00 0.00 0.00 <![CDATA[La 3+ +Gd 3+ +Y 3+ ]]> 38.04 38.05 38.05 <![CDATA[(Si 4+ +B 3+ ) / (The 3+ +Gd 3+ +Y 3+ )]]> 0.87 0.88 0.88 <![CDATA[(Si 4+ +B 3+ ) / (Of 4+ +Nb 5+ +W 6+ +Like 3+ )]]> 1.47 1.52 1.52 <![CDATA[(La 3+ +GD 3+ +Y 3+ ) / (Ti 4+ +Nb 5+ +W 6+ + Ball 3+ )]]> 1.68 1.72 1.72 <![CDATA[Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ]]> 0.00 0.00 0.00 <![CDATA[Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ]]> 0.32 0.32 0.32 <![CDATA[(Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) / (The 3+ +Y 3+ )]]> 0.008 0.008 0.008 <![CDATA[Zn 2+ / (The 3+ +Y 3+ )]]> 0.008 0.008 0.008 <![CDATA[(Zn 2+ +They 2+ ) / La 3+ ]]> 0.011 0.011 0.011 <![CDATA[(Zn 2+ +Ba 2+ ) / (The 3+ +Y 3+ )]]> 0.008 0.008 0.008 <![CDATA[(Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) / (S 4+ i+B 3+ )]]> 0.010 0.009 0.009 <![CDATA[(Gd 3+ +Nb 5+ +W 6+ ) / (Si 4+ +B 3+ +Zn 2+ +La 3+ +Y 3+ +Zr 4+ +Ti 4+ )]]> 0.000 0.000 0.000 <![CDATA[Gd 3++ +W 6+ ]]> 0.00 0.00 0.00 <![CDATA[(Gd 3++ +W 6+ ) / (Si 4+ +B 3+ +Zn 2+ +La 3+ +Y 3+ +Zr 4+ +Ti 4+ )]]> 0.000 0.000 0.000 nd 2.00086 2.00081 2.00081 vd 28.74 28.85 28.85 Pg.F 0.602 0.601 0.601 Liquidus temperature LT(℃) 1330 1320 1320 proportion 4.91 4.92 4.92 Specific gravity / nd 2.45 2.46 2.46 λ70(nm) 455 446 446 λ5(nm) 368 366 360 λ70 / nd(nm) 227.40 222.91 222.91 λ5 / nd(nm) 183.92 182.93 179.93 λ70 / vd(nm) 15.83 15.46 15.46 λ5 / vd(nm) 12.80 12.69 12.48 Glass transition temperature Tg(℃) 755 747 747

[0225] <Evaluation of glass stability>

[0226] Glass is obtained by shaping molten glass. When glass stability is low, the number of crystal grains contained in the glass obtained by pouring the molten glass into a mold and shaping it increases. Therefore, glass stability, particularly the resistance to devitrification when shaping molten glass, can be evaluated by the number of crystals contained in the glass after melting and shaping under certain conditions. An example of the evaluation method is shown below.

[0227] Nitrates, sulfates, carbonates, hydroxides, oxides, boric acid, and other raw materials were weighed and thoroughly mixed to create a raw material mixture. This mixture was then placed in a 300ml platinum crucible and heated and melted in a glass melting furnace set at 1400°C for 2 hours to produce 150g of homogeneous molten glass. During this time, the molten glass was stirred and vibrated several times.

[0228] After 2 hours, the crucible containing the molten glass is taken out from the above-mentioned furnace, stirred and vibrated for 15 to 20 seconds, and then the molten glass is poured into a carbon mold (50mm×40mm×8mm~12mm) and placed in a slow cooling furnace to eliminate strain.

[0229] The interior of the obtained glass was observed using an optical microscope (magnification 100 times), the number of precipitated crystals was counted, and the number of crystals contained per kg of glass was calculated as the number density of crystals (crystals / kg).

[0230] The number density of crystals evaluated by the above method is preferably 2000 pieces / kg or less, more preferably 1000 pieces / kg or less, further preferably 800 pieces / kg or less, further preferably 600 pieces / kg or less, further preferably 400 pieces / kg or less, further preferably 200 pieces / kg or less, further preferably 100 pieces / kg or less, further preferably 50 pieces / kg or less, further preferably 30 pieces / kg or less, and particularly preferably 0 pieces / kg.

[0231] The number density of crystals of each glass shown in Table 2 evaluated by the above method was 0 / kg for all glasses.

[0232] <Example 2>

[0233] Press-molded glass blocks (glass gobs) were prepared using the various glasses obtained in Example 1. These glass gobs were heated and softened in the atmosphere, then press-molded using a press mold to produce lens blanks (optical element blanks). The resulting lens blanks were removed from the press mold, annealed, and subjected to mechanical processing including polishing to produce spherical lenses made from the various glasses produced in Example 1.

[0234] <Example 3>

[0235] A desired amount of the molten glass produced in Example 1 was press-formed in a press-forming mold to produce lens blanks (optical element blanks). The produced lens blanks were removed from the press-forming mold, annealed, and subjected to machining including polishing to produce spherical lenses made from the various glasses produced in Example 1.

[0236] <Example 4>

[0237] The glass blocks (optical element blanks) produced by solidifying the molten glass produced in Example 1 were annealed and subjected to machining including polishing, thereby producing spherical lenses made of the various glasses produced in Example 1.

[0238] <Example 5>

[0239] The spherical lens produced in Examples 2 to 4 is bonded to a spherical lens formed from another type of glass to produce a bonded lens. The bonding surface of the spherical lens produced in Examples 2 to 4 is a convex surface, and the bonding surface of the spherical lens formed from another type of optical glass is a concave surface. The two bonding surfaces are produced so that the absolute values ​​of the curvature radii are equal to each other. An ultraviolet curing adhesive for bonding optical elements is applied to the bonding surface, and the two lenses are bonded to each other at the bonding surface. Then, ultraviolet rays are irradiated onto the adhesive applied to the bonding surface through the spherical lens produced in Examples 2 to 4 to solidify the adhesive.

[0240] A cemented lens was produced as described above.

[0241] Finally, the above-mentioned embodiments are summarized.

[0242] According to one embodiment, an optical glass may be provided, wherein in the glass composition of the optical glass expressed in cation %, Ta 5 + content is in the range of 0 to 5 cation%, Ti 4+ Content relative to Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total cation content ratio (Ti 4+ / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ )) is in the range of 0.60 to 1.00, Si 4+ With B 3+ The total content relative to La 3+ 、Gd 3+ and Y 3+ The total cation content ratio ((Si 4+ +B 3+ ) / (La 3+ +Gd 3+ +Y 3+ )) is in the range of 0.30 to 2.40, Si 4+ With B 3+ The total content relative to Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total cation content ratio ((Si 4+ +B 3+ ) / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ )) is in the range of 0.30 to 34.00, La 3+ 、Gd3+ and Y 3+ The total content relative to Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total cation content ratio (La 3+ +Gd 3+ +Y 3+ ) / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ )) is in the range of 0.30 to 33.00, Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ and Zn 2+ The total content relative to La 3+ With Y 3+ The total cation content ratio (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) / (La 3+ +Y 3+ )) is in the range of 0.00 to 1.50, Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ and Zn 2+ The total content relative to Si 4+ With B 3+ The total cation content ratio (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) / (Si 4+ +B 3+ )) is in the range of 0.00 to 1.00, Gd 3+ 、Nb 5+ and W 6+ The total content relative to Si 4+ 、B 3+ 、Zn 2+ 、La 3+ 、Y 3+ 、Zr 4+ and Ti 4+ The total cation content ratio ((Gd 3+ +Nb 5+ +W 6+ ) / (Si 4+ +B 3+ +Zn2+ +La 3+ +Y 3+ +Zr 4+ +Ti 4+ )) is in the range of 0.000 to 0.100, the refractive index nd of the optical glass is in the range of 1.9000 to 2.1500, and the Abbe number νd is in the range of 20.0 to 35.0.

[0243] The optical glass has optical properties (nd and νd) useful as a material for optical elements. 5 +、Gd 3+ 、Nb 5+ and W 6+ Since the proportion of C₂O₂ is low, it is an optical glass that can contribute to cost reduction of optical elements.

[0244] In one embodiment, the Ti in the optical glass 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total content of cations may be in the range of 0 to 30 cation %.

[0245] In one embodiment, the Gd in the optical glass 3+ 、Nb 5+ and W 6+ The total content of cations may be in the range of 0 to 8 cation %.

[0246] In one embodiment, the La in the optical glass 3+ 、Gd 3+ and Y 3+ The total content of cations may be in the range of 20 to 60 cation %.

[0247] According to one embodiment, a press-molding glass material composed of the above-mentioned optical glass is provided.

[0248] According to one embodiment, an optical element blank formed of the above-mentioned optical glass is provided.

[0249] The above-mentioned press-molding glass raw material and optical element blank are made of Ta, which is an expensive glass component. 5 +、Gd 3+ 、Nb 5+ and W 6+ Since the optical glass has a low proportion, it can contribute to cost reduction of optical elements.

[0250] According to one embodiment, an optical element formed of the above-mentioned optical glass is provided.

[0251] The above optical element is made of Ta which is an expensive glass component. 5 +、Gd 3+ 、Nb 5+ and W 6+ Since the optical glass is formed with a low proportion of the above-mentioned carbon atoms, it can be manufactured at low cost.

[0252] It should be understood that the embodiments disclosed herein are all illustrative and not restrictive. The scope of the present invention is defined by the claims, not the foregoing description, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0253] For example, by adjusting the composition of the glass composition exemplified above as described in the specification, the optical glass according to one embodiment of the present invention can be obtained.

[0254] Furthermore, it is of course possible to arbitrarily combine two or more of the items exemplified or described as preferred ranges in the specification.

Claims

1. An optical glass, wherein: In the glass composition of the optical glass expressed as cation %, Ta 5+ The content is in the range of 0 to 5 cation %, Zr 4+ The content of cationic ions is in the range of 1 to 15%. Al 3+ The content of cationic ions is less than 2%, Zn 2+ The content is in the range of 0 to 1.32 cation %, Gd 3+ The content is in the range of 0 to 1 cation %, Y 3+ The content is in the range of 2 to 12 cation %, Si 4+ With B 3+ The total content (Si 4+ +B 3+ ) is in the range of 31 to 35 cation %, Gd 3+ With W 6+ The total content (Gd 3+ +W 6+ ) is in the range of 0 to 1 cation %, La 3+ 、Gd 3+ and Y 3+ The total content (La 3+ +Gd 3+ +Y 3+ ) is in the range of 36 to 39 cation %, Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total content (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ ) is in the range of 21 to 25 cation %, Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ and Zn 2+ The total content (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) is in the range of 0 to 1.32 cation %, Ti 4+ Content relative to Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total cation content ratio (Ti 4+ / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ )) is in the range of 0.60 to 1.00, Si 4+ With B 3+ The total content relative to La 3+ 、Gd 3+ and Y 3+ The total cation content ratio ((Si 4+ +B 3+ ) / (La 3+ +Gd 3+ +Y 3 + )) is in the range of 0.79 to 0.90, Si 4+ With B 3+ The total content relative to Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total cation content ratio ((Si 4+ +B 3+ ) / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ )) is in the range of 1.36 to 1.47, La 3+ 、Gd 3+ and Y 3+ The total content relative to Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total cation content ratio (La 3+ +Gd 3+ +Y 3 + ) / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ )) is in the range of 1.57 to 5.00, Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ and Zn 2+ The total content relative to La 3+ With Y 3+ The total cation content ratio (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) / (La 3+ +Y 3+ )) is in the range of 0.00 to 0.010, Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ and Zn 2+ The total content relative to Si 4+ With B 3+ The total cation content ratio (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) / (Si 4+ +B 3+ )) is in the range of 0.00 to 0.150, Gd 3+ With W 6+ The total content relative to Si 4+ 、B 3+ 、Zn 2+ 、La 3+ 、Y 3+ 、Zr 4+ and Ti 4+ The total cation content ratio ((Gd 3+ +W 6+ ) / (Si 4+ +B 3+ +Zn 2+ +La 3+ +Y 3+ +Zr 4+ +Ti 4+ )) is in the range of 0.000~0.005, Gd 3+ 、Nb 5+ and W 6+ The total content relative to Si 4+ 、B 3+ 、Zn 2+ 、La 3+ 、Y 3+ 、Zr 4+ and Ti 4+ The total cation content ratio ((Gd 3+ +Nb 5+ +W 6+ ) / (Si 4+ +B 3+ +Zn 2+ +La 3+ +Y 3+ +Zr 4+ +Ti 4+ )) is in the range of 0.000 to 0.100, The cation % represents the molar percentage of the cation amount of interest relative to the total amount of cationic components. As anion components, it contains more than 95.0% of O 2- ion, The refractive index nd of the optical glass is in the range of 1.9950 to 2.0100, and the Abbe number νd is in the range of 27.5 to 30.

5.

2. The optical glass according to claim 1, wherein B 3+ The content is in the range of 10 to 40 cation %, and / or, Si 4+ The content is in the range of 2 to 20 cation %, and / or, B 3+ Content relative to Si 4+ With B 3+ The total content of cation ratio (B 3+ / (Si 4+ +B 3+ )) is in the range of 0.30 to 0.

85.

3. The optical glass according to claim 2, wherein: B 3+ The content is in the range of 15 to 30 cation %, and / or, Si 4+ The content is in the range of 5 to 18 cation %, and / or, B 3+ Content relative to Si 4+ With B 3+ The total content of cation ratio (B 3+ / (Si 4+ +B 3+ )) is in the range of 0.50 to 0.

80.

4. The optical glass according to claim 3, wherein: B 3+ The content is in the range of 18 to 30 cation %, and / or, Si 4+ The content is in the range of 7 to 14 cation %, and / or, B 3+ Content relative to Si 4+ With B 3+ The total content of cation ratio (B 3+ / (Si 4+ +B 3+ )) is in the range of 0.60 to 0.

78.

5. The optical glass according to claim 4, wherein: B 3+ The content ranges from 19 to 26 cation %.

6. The optical glass according to claim 1, wherein: La 3+ The content is in the range of 23 to 50 cation %.

7. The optical glass according to claim 6, wherein: La 3+ The content is in the range of 26 to 40 cation %.

8. The optical glass according to claim 7, wherein: La 3+ The content is in the range of 26 to 37 cation %.

9. The optical glass according to claim 8, wherein: La 3+ The content is in the range of 27 to 35 cation %.

10. The optical glass according to claim 1, wherein: Ti 4+ The content is in the range of 5 to 30 cation %, and / or, Nb 5+ The content is in the range of 0 to 8 cation %, and / or, W 6+ The content is in the range of 0 to 1 cation %, and / or, 5+ The content is in the range of 0 to 4 cation %, and / or, Nb 5+ With W 6+ The total content (Nb 5+ +W 6+ ) is in the range of 0 to 8 cation %, and / or, Ti 4+ Content relative to Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total cation content ratio (Ti 4+ / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ )) is in the range of 0.70 to 1.

00.

11. The optical glass according to claim 10, wherein: Ti 4+ The content is in the range of 15 to 27 cation %, and / or, 5+ The content is in the range of 0 to 1 cation %.

12. The optical glass according to claim 11, wherein: Ti 4+ The content is in the range of 16 to 24 cation %.

13. The optical glass according to claim 1, wherein: Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ The total content (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ) is in the range of 0 to 1 cation %.

14. The optical glass according to claim 1, wherein: Si 4+ With B 3+ The total content relative to La 3+ 、Gd 3+ and Y 3+ The total cation content ratio ((Si 4+ +B 3+ ) / (La 3+ +Gd 3+ +Y 3 + )) is in the range of 0.80 to 0.90, and / or Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ and Zn 2+ The total content relative to Si 4+ With B 3+ The total cation content ratio (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) / (Si 4+ +B 3+ )) is in the range of 0.00 to 0.

100.

15. The optical glass according to claim 1, wherein: Si 4+ With B 3+ The total content relative to La 3+ 、Gd 3+ and Y 3+ The total cation content ratio ((Si 4+ +B 3+ ) / (La 3+ +Gd 3+ +Y 3 + )) is in the range of 0.80 to 0.90, and / or Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ and Zn 2+ The total content relative to Si 4+ With B 3+ The total cation content ratio (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ ) / (Si 4+ +B 3+ )) is in the range of 0.00 to 0.

090.

16. The optical glass according to claim 1, wherein: Gd 3+ 、Nb 5+ and W 6+ The total content (Gd 3+ +Nb 5+ +W 6+ ) is in the range of 0 to 8 cation %, and / or Gd 3+ 、Nb 5+ and W 6+ The total content relative to Si 4+ 、B 3+ 、Zn 2+ 、La 3+ 、Y 3+ 、Zr 4+ and Ti 4+ The total cation content ratio ((Gd 3+ +Nb 5+ +W 6+ ) / (Si 4+ +B 3+ +Zn 2+ +La 3+ +Y 3+ +Zr 4+ +Ti 4+ )) is in the range of 0.000 to 0.

090.

17. The optical glass according to claim 1, wherein: Gd 3+ 、Nb 5+ and W 6+ The total content (Gd 3+ +Nb 5+ +W 6+ ) is in the range of 0 to 8 cation %, and / or Gd 3+ 、Nb 5+ and W 6+ The total content relative to Si 4+ 、B 3+ 、Zn 2+ 、La 3+ 、Y 3+ 、Zr 4+ and Ti 4+ The total cation content ratio ((Gd 3+ +Nb 5+ +W 6+ ) / (Si 4+ +B 3+ +Zn 2+ +La 3+ +Y 3+ +Zr 4+ +Ti 4+ )) is in the range of 0.000 to 0.

080.

18. The optical glass according to claim 1, wherein: La 3+ 、Gd 3+ and Y 3+ The total content relative to Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total cation content ratio (La 3+ +Gd 3+ +Y 3 + ) / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ )) is in the range of 1.57 to 1.

70.

19. The optical glass according to claim 1, wherein: Zr 4+ The content is in the range of 0 to 10 cation %.

20. The optical glass according to claim 19, wherein: Zr 4+ The content is in the range of 4 to 7 cation %.

21. The optical glass according to claim 1, wherein: Al 3+ The content is in the range of 0 to 1 cation %.

22. The optical glass according to claim 1, wherein: Li + The content is in the range of 0 to 1 cation %, and / or Na + The content is in the range of 0 to 1 cation %, and / or, K + The content is in the range of 0 to 1 cation %.

23. A press-molding glass material, comprising the optical glass according to any one of claims 1 to 22.

24. An optical element blank formed of the optical glass according to any one of claims 1 to 22. 25 . An optical element formed of the optical glass according to claim 1 .