Optical glass and optical element

Abstract

The present application provides an optical glass having a low glass transition temperature and excellent thermal stability. The optical glass has a glass composition represented in terms of cation % in which Li + is more than 0.0 cation % and 48.0 % or less, Na + is more than 0.0 cation % and 35.0 % or less, K + is more than 0.0 cation % and 30.0 % or less, the total content of Al 3+ + P 5+ is 38.0 to 70.0 %, the total content of Li + , Na + , K + and Cs + is set as R + , the total content of Be 2+ , Mg 2+ , Ca 2+ , Sr 2+ and Ba 2+ is set as R 2+ , the cation ratio (R + / (Al 3+ + P 5+ )) is 0.93 or more, (Li + / (R + + R 2+ )) is 0.29 or more, ((Li + + K + ) / (Al 3+ + P 5+ )) is 0.56 or more, (R 2+ / (Al 3+ + R 2+ )) is 0.37 or less, the glass composition represented in terms of anion % has O 2‑ content of 83.0 % or less, F ‑ content of 19.0 % or more, and its external transmittance at a wavelength of 500 nm to 1000 nm, converted to a thickness of 10.0 mm, is 80 % or more.

Description

Technical Field

[0001] This invention relates to optical glass and optical components. Background Technology

[0002] For example, patent document 1 discloses an optical glass with a low glass transition temperature.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: WO2003 / 037813 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] Glasses with low glass transition temperatures can be molded at low temperatures. Considering factors such as less degradation of the molding die due to heating and the ability to use molding dies with low heat resistance and low cost, molding at low temperatures is preferable. However, the inventors' research on optical glasses with low glass transition temperatures has revealed that further improvements in thermal stability are expected.

[0008] One aspect of the present invention is to provide optical glass with a low glass transition temperature and excellent thermal stability.

[0009] Problem Solving Methods

[0010] One aspect of the present invention relates to an optical glass having, in a glass composition expressed as cations%,

[0011] Li + The content exceeds 0.0% cations but is below 48.0% cations.

[0012] Na + The content exceeds 0.0% cations but is below 35.0% cations.

[0013] K + Content exceeding 0.0% cations and below 30.0% cations,

[0014] Al 3+ With P 5+ Total content (Al) 3+ +P 5+ The cation content is ≥38.0% and ≤70.0%

[0015] Among them, Li + Na + K + and Cs + The total content is set as R.+ , will Be 2+ Mg 2+ Ca 2+ 、Sr 2+ And Ba 2+ The total content is set as R. 2+ ,

[0016] R + Compared to Al 3+ With P 5+ The total content of cation ratio (R) + / (Al 3+ +P 5+ The value of Li is above 0.93. + Content relative to R + With R 2+ The total cation ratio (Li + / (R + +R 2+ The value is above 0.29.

[0017] Li + With K + The total content relative to Al 3+ With P 5+ The total content of cation ratio ((Li + +K + ) / (Al 3+ +P 5+ The value is above 0.56.

[0018] R 2+ Compared to Al 3+ Content and R 2+ The total cation ratio (R) 2+ / (Al 3+ +R 2+ The value is below 0.37.

[0019] In the glass composition expressed as anion %

[0020] O 2- The content is below 83.0% anion.

[0021] F - The content is above 19.0% anion.

[0022] Furthermore, the external transmittance of the optical glass at the wavelengths of 500nm to 1000nm, converted to a thickness of 10.0mm, is over 80%.

[0023] The optical glass described above, by having the aforementioned glass composition, can have a low glass transition temperature and exhibit excellent thermal stability.

[0024] Effects of the Invention

[0025] According to one embodiment of the present application, an optical glass having a low glass transition temperature and excellent thermal stability can be provided. In addition, according to one embodiment of the present application, an optical element formed of such an optical glass can be provided. DETAILED DESCRIPTION

[0026] [Optical Glass]

[0027] In the present application and the present specification, the content and the total content of the cation component are expressed in terms of cation % unless otherwise specified, and the content and the total content of the anion component are expressed in terms of anion % unless otherwise specified.

[0028] Here, "cation %" is a value calculated as "(number of cations of interest / total number of cations of glass components) x 100", and represents the molar percentage of the amount of the cation of interest with respect to the total amount of the cation component.

[0029] In addition, "anion %" is a value calculated as "(number of anions of interest / total number of anions of glass components) x 100", and represents the molar percentage of the amount of the anion of interest with respect to the total amount of the anion component.

[0030] The molar ratio of the content between the cation components is equal to the ratio of the content expressed in terms of cation % of the cation component of interest.

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

[0032] Regarding the cation component, for example, like Al 3+ , P 5+ Thus, the valence of the cation component (for example, the valence of Al 3+ is +3, and the valence of P 5+ is +5) is a value determined in accordance with a custom, as is the case where Al, P, or the like is expressed as Al2O3, P2O5, or the like on an oxide basis. Regarding a component expressed as A m O n (A represents a cation, O represents oxygen, and m and n are integers determined stoichiometrically) on an oxide basis, the cation A is expressed as A s+ where s = 2n / m. Therefore, for example, when analyzing and quantifying the glass composition, the valence of the cation component can not be analyzed. The above points are also the same for the anion component, and the valence of the anion component can not be analyzed when analyzing and quantifying the glass composition.

[0033] In addition, in the present application and the present specification, the content of a constituent component is 0.0%, 0.00%, not contained, or not introduced, meaning that the constituent component is substantially not contained, and the content of the constituent component is at an impurity level or less, meaning, for example, less than 0.01%.

[0034] In the present application and the present specification, "thermal stability" means the degree of crystallization that does not easily occur when a glass in a molten state is solidified.

[0035] Hereinafter, the glass transition temperature is sometimes expressed as Tg.

[0036] Hereinafter, the above-described optical glass (sometimes referred to simply as "glass") is described in more detail.

[0037] <Composition of Glass>

[0038] Hereinafter, the glass composition of the above-described optical glass is described in terms of cation %. In the present application and the present specification, the total content of Li + , Na + , K + , and Cs + is denoted as "R + ", and the total content of Be 2+ , Mg 2+ , Ca 2+ , Sr 2+ , and Ba 2+ is denoted as "R 2+ ".

[0039] From the viewpoint of increasing the refractive index and maintaining low dispersion, and the viewpoint of lowering the Tg of the glass and improving the meltability, the content of Li + is more preferably 2.0% or more, and even more preferably 4.0% or more, 6.0% or more, 8.0% or more, 10.0% or more, 11.0% or more, 12.0% or more, 13.0% or more, 14.0% or more, 15.0% or more, 16.0% or more, or 17.0% or more, in this order.

[0040] In addition, from the viewpoint of improving the thermal stability of the glass and maintaining the thermal stability of the glass, the content of Li + is preferably 48.0 cation % or less, and even more preferably 47.0% or less, in this order.

[0041] From the viewpoint of maintaining the refractive index, maintaining low dispersion, lowering the Tg of the glass, improving the meltability, and lowering the specific gravity, the content of Na +The content is more than 0.0 cation %, preferably 1.0 % or more, more preferably in the order of 2.0 % or more, 3.0 % or more, 4.0 % or more.

[0042] In addition, from the viewpoint of maintaining the thermal stability of the glass, Na + The content is 35.0 cation % or less, preferably 34.0 % or less, more preferably in the order of 33.0 % or less, 32.0 % or less, 31.0 % or less, 30.0 % or less, 29.0 % or less, 28.0 % or less, 27.0 % or less, 26.0 % or less.

[0043] From the viewpoint of maintaining the refractive index, maintaining low dispersion, lowering the Tg of the glass, and improving the meltability, K + The content is more than 0.0 cation %, preferably 1.0 % or more, more preferably in the order of 2.0 % or more, 3.0 % or more, 4.0 % or more.

[0044] In addition, from the viewpoint of maintaining the thermal stability of the glass, K + The content is 30.0 cation % or less, preferably 29.0 % or less, more preferably in the order of 28.0 % or less, 27.0 % or less, 26.0 % or less, 25.0 % or less, 24.0 % or less, 23.0 % or less, 22.0 % or less, 21.0 % or less, 20.0 % or less, 19.0 % or less, 18.0 % or less.

[0045] Cs + The content can be 0.0 %, or can be 0.0 % or more, or can be more than 0.0 %. From the viewpoint of further lowering the Tg of the glass and improving the meltability of the glass, Cs + The content can be 0.0 % or more, preferably 0.1 % or more, more preferably in the order of 0.2 % or more, 0.3 % or more, 0.4 % or more, 0.5 % or more, 0.6 % or more.

[0046] In addition, from the viewpoint of further improving the thermal stability of the glass and suppressing the decrease in chemical durability, Cs + The content is preferably 10.0 % or less, more preferably in the order of 8.0 % or less, 6.0 % or less, 4.0 % or less, 2.0 % or less, 1.5 % or less, 1.0 % or less.

[0047] From the viewpoint of maintaining low dispersion, further lowering the Tg of the glass, lowering the specific gravity, and lowering the liquidus temperature, Li + , Na + , K + , and Cs + The total content R +Preferably, it is 5.0% or more, more preferably 10.0% or more, and further preferably in the order of 15.0% or more, 20.0% or more, 23.0% or more, 25.0% or more, 28.0% or more, 30.0% or more, 33.0% or more, 35.0% or more, 37.0% or more, 40.0% or more, 41.0% or more, 42.0% or more, 43.0% or more, 44.0% or more, 45.0% or more, 46.0% or more, 47.0% or more, and 48.0% or more.

[0048] Furthermore, considering the need to maintain low dispersion, preserve the thermal stability of the glass, and inhibit the degradation of chemical durability, Li + Na + K + and Cs + Total content R + Preferably, it is 65.0% or less, and more preferably in the order of 64.0% or less, 63.0% or less, 62.0% or less, 61.0% or less, 60.0% or less, and 59.0% or less.

[0049] From the perspective of maintaining the thermal stability of glass, Al 3+ With P 5+ Total content (Al) 3+ +P 5+ The cation content is 38.0% or more, preferably 38.1% or more, and more preferably in the order of 38.2% or more, 38.3% or more, 38.4% or more, 38.5% or more, 38.6% or more, 38.7% or more, 38.8% or more, 38.9% or more, and 39.0% or more.

[0050] Furthermore, from the perspective of suppressing the rise of Tg, Al 3+ With P 5+ Total content (Al) 3+ +P 5+ The content of cations is 70.0% or less, preferably 65.0% or less, and more preferably in the order of 60.0% or less, 59.0% or less, 58.0% or less, 57.0% or less, 56.0% or less, 55.0% or less, 54.0% or less, 53.0% or less, 52.0% or less, 51.0% or less, and 50.0% or less.

[0051] From the perspective of increasing the refractive index while maintaining low dispersion, and from the perspective of further improving the thermal stability and maintaining the chemical durability of glass, Al 3+The content is preferably more than 0.0%, more preferably more than 1.0%, and further preferred in the order of more than 2.0%, more than 3.0%, more than 4.0%, more than 5.0%, more than 6.0%, more than 7.0%, more than 8.0%, more than 9.0%, more than 10.0%, and more than 11.0%.

[0052] Furthermore, considering the need to further suppress the rise of Tg, Al 3+ The content is preferably 30.0% or less, more preferably 29.0% or less, and further preferably in the order of 28.0% or less, 27.0% or less, 26.0% or less, 25.0% or less, 24.0% or less, 23.0% or less, 22.0% or less, 21.0% or less, 20.0% or less, 19.0% or less, and 18.0% or less.

[0053] From the perspective of maintaining low dispersion and further improving the thermal stability of glass, P 5+ The content is preferably 5.0% or more, more preferably 7.0% or more, and further preferred in the order of 9.0% or more, 11.0% or more, 13.0% or more, 14.0% or more, 15.0% or more, 16.0% or more, 17.0% or more, 18.0% or more, 19.0% or more, 20.0% or more, 21.0% or more, 22.0% or more, and 23.0% or more.

[0054] Furthermore, from the perspectives of maintaining the refractive index, further improving the thermal stability of the glass, and suppressing the decline in chemical durability, P 5+ The content is preferably 50.0% or less, more preferably 48.0% or less, and further preferably in the order of 46.0% or less, 44.0% or less, 42.0% or less, 40.0% or less, 38.0% or less, 37.0% or less, 36.0% or less, 35.0% or less, 34.0% or less, 33.0% or less, and 32.0% or less.

[0055] From the perspective of reducing the Tg of glass and improving its melting properties, R + Compared to Al 3+ With P 5+ The total content of cation ratio (R) + / (Al 3+ +P 5+ The value is 0.93 or higher, preferably 0.94 or higher, and more preferably 0.95 or higher and 0.96 or higher in that order.

[0056] Furthermore, from the viewpoint of maintaining the thermal stability of glass, the cation ratio (R) + / (Al 3+ +P 5+Preferably, the value is 3.00 or less, more preferably 2.75 or less, and further preferably in the order of 2.50 or less, 2.25 or less, 2.00 or less, 1.90 or less, 1.80 or less, 1.70 or less, 1.65 or less, 1.60 or less, 1.55 or less, 1.50 or less, 1.45 or less, and 1.40 or less.

[0057] From the perspectives of increasing refractive index, lowering Tg of glass, and improving glass meltability, Li + Content relative to R + With R 2+ The total cation ratio (Li + / (R + +R 2+ The value is 0.29 or higher, preferably 0.30 or higher, and more preferably 0.31 or higher and 0.32 or higher in that order.

[0058] Furthermore, from the viewpoint of maintaining the thermal stability of glass, the cation ratio (Li) + / (R + +R 2+ Preferably, the value is 1.00 or less, more preferably 0.95 or less, and even more preferably in the order of 0.94 or less, 0.93 or less, 0.92 or less, 0.91 or less, 0.90 or less, 0.89 or less, 0.88 or less, 0.87 or less, 0.86 or less, 0.85 or less, 0.84 or less, and 0.83 or less.

[0059] From the perspective of further reducing the Tg of glass, improving its melting point, and reducing its specific gravity, Li + With K + The total content relative to Al 3+ With P 5+ The total content of cation ratio ((Li + +K + ) / (Al 3+ +P 5+ The value is 0.56 or higher, preferably 0.57 or higher, and more preferably in the order of 0.58 or higher, 0.59 or higher, 0.60 or higher, 0.61 or higher, 0.62 or higher, 0.63 or higher, 0.64 or higher, and 0.65 or higher.

[0060] Furthermore, from the perspective of maintaining refractive index and thermal stability, the cation ratio ((Li) + +K + ) / (Al 3+ +P 5+) is preferably 2.00 or less, more preferably 1.80 or less, further preferably 1.70 or less, 1.60 or less, 1.50 or less, 1.40 or less, 1.30 or less, 1.20 or less, 1.10 or less in this order.

[0061] From the viewpoint of maintaining the thermal stability of the glass, R 2+ With respect to Al 3+ , the content of R 2+ is preferably 0.20 or more, more preferably 0.25 or more, further preferably 0.30 or more, 0.35 or more, 0.40 or more, 0.45 or more, 0.50 or more, 0.55 or more, 0.60 or more, 0.65 or more, 0.70 or more, 0.75 or more, 0.80 or more, 0.85 or more, 0.90 or more, 0.95 or more, 1.00 or more in this order. 2+ 3+ The sum of the contents of R 2+ and R 2+ is preferably 0.37 or less, more preferably 0.36 or less, further preferably 0.35 or less, 0.34 or less, 0.33 or less, 0.32 or less, 0.31 or less, 0.30 or less in this order.

[0062] In addition, the cation ratio (R 3+ / (Al 2+ + R 2+ )) can be 0.00 or more than 0.00. From the viewpoint of lowering the liquidus temperature and increasing the refractive index, the cation ratio (R 3+ / (Al 2+ + R 2+ )) is preferably 0.00 or more, more preferably 0.01 or more, further preferably 0.02 or more, 0.03 or more in this order.

[0063] The total content R 2+ of Be 2+ , Mg 2+ , Ca 2+ , Sr 2+ , and Ba 2+ may be 0.0%, 0.0% or more, or more than 0.0%. From the viewpoint of maintaining the refractive index, maintaining low dispersion, suppressing the rise in Tg, and maintaining the thermal stability of the glass, the total content R 2+ is preferably 20.0% or less, more preferably 19.0% or less, further preferably 18.0% or less, 17.0% or less, 16.0% or less, 15.0% or less, 14.0% or less, 13.0% or less, 12.0% or less, 11.0% or less, 10.0% or less, 9.0% or less, 8.0% or less, 7.0% or less in this order.

[0064] The content of Be 2+ ​The content is preferably 15.0% or less, more preferably 10.0% or less, further preferably 5.0% or less, 2.5% or less, 1.5% or less, 1.0% or less, 0.5% or less in this order.

[0065] Mg 2+ The content can be 0.0%, 0.0% or more, or more than 0.0%. From the viewpoint of maintaining the refractive index, maintaining low dispersion, suppressing the rise of Tg, and maintaining the thermal stability of the glass, Mg 2+ The content is preferably 15.0% or less, more preferably 14.0% or less, further preferably 13.0% or less, 12.0% or less, 11.0% or less, 10.0% or less, 9.0% or less, 8.0% or less, 7.0% or less, 6.0% or less in this order.

[0066] Ca 2+ The content can be 0.0%, 0.0% or more, or more than 0.0%. From the viewpoint of maintaining the refractive index, maintaining low dispersion, suppressing the rise of Tg, and maintaining the thermal stability of the glass, Ca 2+ The content is preferably 10.0% or less, more preferably 9.0% or less, further preferably 8.0% or less, 7.0% or less, 6.0% or less, 5.0% or less in this order.

[0067] Sr 2+ The content can be 0.0%, 0.0% or more, or more than 0.0%. From the viewpoint of maintaining the refractive index, maintaining low dispersion, suppressing the rise of Tg, and maintaining the thermal stability of the glass, Sr 2+ The content is preferably 10.0% or less, more preferably 9.0% or less, further preferably 8.0% or less, 7.0% or less, 6.0% or less, 5.0% or less, 4.0% or less in this order.

[0068] Ba 2+ The content can be 0.0%, 0.0% or more, or more than 0.0%. From the viewpoint of maintaining the refractive index, maintaining low dispersion, suppressing the rise of Tg, and maintaining the thermal stability of the glass, Ba 2+ The content is preferably 10.0% or less, more preferably 9.0% or less, further preferably 8.0% or less, 7.0% or less, 6.0% or less, 5.0% or less, 4.0% or less, 3.0% or less, 2.0% or less in this order.

[0069] Zn 2+ The content can be 0.0%, 0.0% or more, or more than 0.0%. Zn 2+ It plays a role of maintaining the refractive index and improving the thermal stability, but if it is contained in excess, there is a tendency that the dispersion becomes high. From the above viewpoint, Zn 2+The content is preferably 20.0% or less, more preferably 19.0% or less, further preferably 18.0% or less, 17.0% or less, 16.0% or less, 15.0% or less, 14.0% or less, 13.0% or less, 12.0% or less, 11.0% or less, 10.0% or less, 9.0% or less, 8.0% or less, 7.0% or less, 6.0% or less, 5.0% or less, in this order.

[0070] Zr 4+ The content can be 0.0%, 0.0% or more, or more than 0.0%. Zr 4+ is a component that increases the refractive index, but if contained in excess, there is a tendency for the dispersion to become high, and there is a tendency for the Tg to rise. From the above viewpoint, Zr 4+ The content is preferably 10.0% or less, more preferably 9.0% or less, further preferably 8.0% or less, 7.0% or less, 6.0% or less, 5.0% or less, 4.0% or less, 3.0% or less, 2.0% or less, in this order.

[0071] Nb 5+ The content can be 0.0%, 0.0% or more, or more than 0.0%. Nb 5+ is a component that increases the refractive index, but if contained in excess, there is a tendency for the dispersion to become high, and there is a tendency for the Tg to rise. From the above viewpoint, Nb 5+ The content is preferably 10.0% or less, more preferably 9.0% or less, further preferably 8.0% or less, 7.0% or less, 6.0% or less, 5.0% or less, 4.0% or less, 3.0% or less, 2.0% or less, in this order.

[0072] Ti 4+ The content can be 0.0%, 0.0% or more, or more than 0.0%. Ti 4+ is a component that increases the refractive index, but if contained in excess, there is a tendency for the dispersion to become high, and there is a tendency for the Tg to rise. From the above viewpoint, Ti 4+ The content is preferably 10.0% or less, more preferably 9.0% or less, further preferably 8.0% or less, 7.0% or less, 6.0% or less, 5.0% or less, 4.0% or less, 3.0% or less, 2.0% or less, in this order.

[0073] W 6+ The content can be 0.0%, 0.0% or more, or more than 0.0%. W 6+ is a component that increases the refractive index, but if contained in excess, there is a tendency for the dispersion to become high, and there is a tendency for the Tg to rise. From the above viewpoint, W 6+The content is preferably 10.0% or less, more preferably 9.0% or less, and further preferably in the order of 8.0% or less, 7.0% or less, 6.0% or less, 5.0% or less, 4.0% or less, 3.0% or less, and 2.0% or less.

[0074] Li + with Na + The total content relative to Li + With K + The total content of cation ratio ((Li + +Na + ) / (Li + +K + The Tg value can exceed 0.00. From the viewpoint of maintaining the thermal stability of the glass, further reducing the Tg, and improving the meltability of the glass, it is preferred to be 0.50 or more, more preferably 0.55 or more, and further preferred in the order of 0.60 or more, 0.65 or more, 0.66 or more, 0.67 or more, 0.68 or more, 0.69 or more, 0.70 or more, 0.71 or more, 0.72 or more, 0.73 or more, 0.74 or more, 0.75 or more, 0.76 or more, 0.77 or more, 0.78 or more, 0.79 or more, and 0.80 or more.

[0075] Furthermore, from the perspective of maintaining the thermal stability of the glass, further reducing Tg, and improving the melting properties of the glass, the cation ratio ((Li) + +Na + ) / (Li + +K + Preferably, the value is 2.05 or less, more preferably 2.00 or less, and further preferably in the order of 1.95 or less, 1.90 or less, 1.85 or less, 1.80 or less, 1.75 or less, 1.70 or less, 1.65 or less, 1.64 or less, 1.63 or less, 1.62 or less, 1.61 or less, 1.60 or less, 1.59 or less, 1.58 or less, 1.57 or less, 1.56 or less, 1.55 or less, 1.54 or less, 1.53 or less, 1.52 or less, 1.51 or less, and 1.50 or less.

[0076] Na + With K + The total content relative to Li + With K + The total content of cations (Na) + +K + ) / (Li + +K +The Tg value can exceed 0.00. From the viewpoint of maintaining the thermal stability of the glass, further reducing the Tg, and improving the meltability of the glass, it is preferred to be 0.05 or more, more preferably 0.07 or more, and further preferred in the order of 0.09 or more, 0.11 or more, 0.13 or more, 0.15 or more, 0.16 or more, 0.17 or more, 0.18 or more, 0.19 or more, and 0.20 or more.

[0077] Furthermore, from the perspective of maintaining the thermal stability of the glass, further reducing Tg, and improving the melting properties of the glass, the cation ratio ((Na) + +K + ) / (Li + +K + Preferably, the value is 2.00 or less, more preferably 1.95 or less, and further preferably in the order of 1.90 or less, 1.85 or less, 1.80 or less, 1.75 or less, 1.70 or less, 1.55 or less, 1.50 or less, 1.45 or less, 1.40 or less, 1.39 or less, 1.38 or less, 1.37 or less, 1.36 or less, 1.35 or less, 1.34 or less, 1.33 or less, 1.32 or less, 1.31 or less, and 1.30 or less.

[0078] Li + Content relative to Li + with Na + The total content of cation ratio (Li + / (Li + +Na + The Tg value can exceed 0.00. From the viewpoint of maintaining the thermal stability of the glass, further reducing the Tg, and improving the meltability of the glass, it is preferably 0.05 or more, more preferably 0.10 or more, and further preferred in the order of 0.20 or more, 0.25 or more, 0.30 or more, 0.31 or more, 0.32 or more, 0.33 or more, 0.34 or more, 0.35 or more, 0.36 or more, 0.37 or more, 0.38 or more, 0.39 or more, and 0.40 or more.

[0079] Furthermore, from the perspectives of maintaining the thermal stability of the glass, further reducing Tg, and improving the glass's melting properties, the cation ratio (Li) + / (Li + +Na + Preferably, the value is 1.00 or less, more preferably 0.98 or less, and even more preferably in the order of 0.96 or less, 0.94 or less, 0.93 or less, 0.92 or less, 0.91 or less, 0.90 or less, 0.89 or less, and 0.88 or less.

[0080] Li + Content relative to Li + With K+ The total content of cation ratio (Li + / (Li + +K + The Tg value can exceed 0.00. From the viewpoint of maintaining the thermal stability of the glass, further reducing the Tg, and improving the meltability of the glass, it is preferred to be 0.30 or more, more preferably 0.35 or more, and further preferred in the order of 0.40 or more, 0.42 or more, 0.44 or more, 0.46 or more, 0.48 or more, 0.50 or more, 0.52 or more, 0.54 or more, and 0.56 or more.

[0081] Furthermore, from the perspectives of maintaining the thermal stability of the glass, further reducing Tg, and improving the glass's melting properties, the cation ratio (Li) + / (Li + +K + Preferably, the content is 0.99 or less, more preferably 0.98 or less, and further preferably in the order of 0.97 or less, 0.96 or less, 0.95 or less, 0.94 or less, 0.93 or less, 0.92 or less, 0.91 or less, and 0.90 or less.

[0082] Li + Content relative to Na + With K + The total content of cation ratio (Li + / (Na + +K + The Tg value can exceed 0.00. From the viewpoint of maintaining the thermal stability of the glass, further reducing the Tg, and improving the meltability of the glass, it is preferred to be 0.10 or more, more preferably 0.20 or more, and further preferred in the order of 0.25 or more, 0.30 or more, 0.35 or more, 0.40 or more, 0.41 or more, 0.42 or more, 0.43 or more, 0.44 or more, and 0.45 or more.

[0083] Furthermore, from the perspectives of maintaining the thermal stability of the glass, further reducing Tg, and improving the glass's melting properties, the cation ratio (Li) + / (Na + +K + Preferably, the value is 5.50 or less, more preferably 4.90 or less, and further preferably in the order of 4.80 or less, 4.70 or less, 4.60 or less, 4.50 or less, and 4.40 or less.

[0084] From the perspective of maintaining the thermal stability of glass, further reducing Tg, and improving the melting properties of glass, Na + Content relative to Na + With Li + The total content of cation ratio (Na) + / (Na+ +Li + Preferably, the value is 0.85 or less, more preferably 0.80 or less, and further preferably in the order of 0.75 or less, 0.74 or less, 0.73 or less, 0.72 or less, 0.71 or less, 0.70 or less, 0.69 or less, 0.68 or less, 0.67 or less, 0.66 or less, and 0.65 or less.

[0085] In addition, the cation ratio (Na) + / (Na + +Li + The Tg value can exceed 0.00. From the viewpoint of maintaining the thermal stability of the glass, further reducing the Tg, and improving the meltability of the glass, it is preferred to be 0.03 or more, more preferably 0.04 or more, and further preferred in the order of 0.05 or more, 0.06 or more, 0.07 or more, 0.08 or more, 0.09 or more, and 0.10 or more.

[0086] From the perspective of maintaining the thermal stability of glass, further reducing Tg, and improving the melting properties of glass, Na + Content relative to Na + With K + The total content of cation ratio (Na) + / (Na + +K + Preferably, the value is 0.95 or less, more preferably 0.92 or less, and further preferably in the order of 0.89 or less, 0.86 or less, 0.85 or less, 0.84 or less, 0.83 or less, 0.82 or less, 0.81 or less, 0.80 or less, 0.79 or less, 0.78 or less, and 0.77 or less.

[0087] In addition, the cation ratio (Na) + / (Na + +K + The Tg value can exceed 0.00. From the viewpoint of maintaining the thermal stability of the glass, further reducing the Tg, and improving the meltability of the glass, it is preferred to be 0.10 or more, more preferably 0.15 or more, and further preferred in the order of 0.20 or more, 0.22 or more, 0.24 or more, 0.26 or more, 0.27 or more, 0.28 or more, 0.29 or more, 0.30 or more, 0.31 or more, and 0.32 or more.

[0088] From the perspective of maintaining the thermal stability of glass, further reducing Tg, and improving the melting properties of glass, Na + Content relative to Li + With K + The total content of cation ratio (Na) + / (Li + +K +) is preferably 1.00 or less, more preferably 0.98 or less, further preferably 0.96 or less, 0.94 or less, 0.92 or less, 0.90 or less, 0.88 or less, 0.86 or less, 0.84 or less in this order.

[0089] In addition, the cation ratio (Na + / (Li + + K + ) can exceed 0.00, and is preferably 0.03 or more, more preferably 0.05 or more, further preferably 0.06 or more, 0.07 or more, 0.08 or more, 0.09 or more, 0.10 or more, 0.11 or more in this order from the viewpoint of maintaining the thermal stability of the glass, further lowering the Tg, and improving the melting property of the glass.

[0090] K + content relative to the total content of K + and Li + , the cation ratio (K + / (K + + Li + ) can exceed 0.00, and is preferably 0.01 or more, more preferably 0.03 or more, further preferably 0.05 or more, 0.06 or more, 0.07 or more, 0.08 or more, 0.09 or more in this order from the viewpoint of maintaining the thermal stability of the glass, further lowering the Tg, and improving the melting property of the glass.

[0091] In addition, from the viewpoint of maintaining the thermal stability of the glass, further lowering the Tg, and improving the melting property of the glass, the cation ratio (K + / (K + + Li + ) is preferably 0.70 or less, more preferably 0.65 or less, further preferably 0.60 or less, 0.59 or less, 0.58 or less, 0.57 or less, 0.56 or less, 0.55 or less, 0.54 or less, 0.53 or less, 0.52 or less, 0.51 or less, 0.50 or less, 0.49 or less, 0.48 or less, 0.47 or less, 0.46 or less, 0.45 or less, 0.44 or less, 0.43 or less in this order.

[0092] K + content relative to the total content of K + and Na + , the cation ratio (K + / (K + + Na +The Tg value can exceed 0.00. From the viewpoint of maintaining the thermal stability of the glass, further reducing the Tg, and improving the meltability of the glass, it is preferred to be 0.10 or more, more preferably 0.12 or more, and further preferred in the order of 0.14 or more, 0.15 or more, 0.16 or more, 0.17 or more, 0.18 or more, 0.19 or more, and 0.20 or more.

[0093] Furthermore, from the perspectives of maintaining the thermal stability of glass, further reducing Tg, and improving the melting properties of glass, the cationic ratio (K) + / (K + +Na + Preferably, the value is 0.80 or less, more preferably 0.77 or less, and further preferably in the order of 0.75 or less, 0.74 or less, 0.73 or less, 0.72 or less, 0.71 or less, 0.70 or less, 0.69 or less, and 0.68 or less.

[0094] K + Content relative to Li + with Na + The total content of cation ratio (K) + / (Li + +Na + The value can exceed 0.00. From the viewpoint of maintaining the thermal stability of the glass, further reducing the Tg and improving the meltability of the glass, it is preferred to be 0.01 or more, more preferably 0.03 or more, and even more preferably in the order of 0.05 or more, 0.06 or more, 0.07 or more, and 0.08 or more.

[0095] Furthermore, from the perspectives of maintaining the thermal stability of glass, further reducing Tg, and improving the melting properties of glass, the cationic ratio (K) + / (Li + +Na + Preferably, the value is 1.10 or less, more preferably 1.00 or less, and further preferably in the order of 0.90 or less, 0.80 or less, 0.70 or less, 0.60 or less, 0.59 or less, 0.58 or less, 0.57 or less, 0.56 or less, 0.55 or less, 0.54 or less, 0.53 or less, 0.52 or less, 0.51 or less, and 0.50 or less.

[0096] From the perspective of further reducing Tg and suppressing the decrease in the thermal stability of glass, R 2+ Compared to Al 3+ The ratio of cations in the content (R) 2+ / Al 3+) is preferably 0.74 or less, more preferably 0.73 or less, further preferably 0.71 or less, 0.69 or less, 0.67 or less, 0.65 or less, 0.63 or less, 0.61 or less, 0.59 or less, 0.57 or less, 0.55 or less, 0.54 or less, 0.53 or less, 0.52 or less, 0.51 or less, 0.50 or less, 0.49 or less, 0.48 or less, 0.47 or less, 0.46 or less, 0.45 or less, 0.44 or less, 0.43 or less, 0.42 or less, 0.41 or less, 0.40 or less, 0.39 or less, in the order of preference.

[0097] Further, the cation ratio (R 2+ / Al 3+ ) can be 0.00 or more than 0.00. From the viewpoint of further lowering the Tg and suppressing the decrease in thermal stability of the glass, the cation ratio (R 2+ / Al 3+ ) is preferably 0.00 or more, more preferably 0.005 or more, further preferably 0.007 or more, 0.010 or more, in the order of preference.

[0098] In one embodiment, the above optical glass can be a glass not containing S 6+ .

[0099] Pb, As, Cd, Tl, Be, and Se are each toxic, and therefore, it is preferable that these elements are not contained, i.e., these elements are not introduced into the glass as glass components.

[0100] U, Th, and Ra are each radioactive elements, and therefore, it is preferable that these elements are not contained, i.e., these elements are not introduced into the glass as glass components.

[0101] V, Cr, Mn, Fe, Co, Ni, Cu, Pr, Nd, Pm, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Ce can cause an increase in coloring of the glass or become a source of fluorescence, and therefore, it is not preferable as an element contained in the glass for optical use. Therefore, it is preferable that these elements are not contained, i.e., these elements are not introduced into the glass as glass components.

[0102] Sb and Sn are optional elements that function as fining agents.

[0103] The Sb content of the above optical glass can be, for example, 0.40% or less, 0.20% or less, 0.10% or less, 0.05% or less, 0.02% or less, 0.01% or less, in terms of the mass fraction (%) of Sb203when the mass of the glass is taken as 100. On the other hand, the Sb content can be 0.00% or more, or 0.00%, in terms of the mass fraction (%) of Sb203when the mass of the glass is taken as 100.

[0104] The Sn content of the optical glass described above can be, for example, 0.40% or less, 0.20% or less, 0.10% or less, 0.05% or less, 0.02% or less, 0.01% or less, in terms of the mass fraction (%) of Sn02when the mass of the glass is taken as 100. On the other hand, the Sn content can be 0.00% or more, or 0.00%, in terms of the mass fraction (%) of Sn02when the mass of the glass is taken as 100.

[0105] The cation component has been described above. Next, the anion component will be described.

[0106] The optical glass described above contains at least F - as the anion component.

[0107] From the viewpoint of lowering the Tgof the glass and maintaining the low dispersion of the glass, F - the content is preferably 60.0% or less, more preferably 59.0% or less, and is further preferably 58.0% or less, 57.0% or less, 56.0% or less, 55.0% or less, 54.0% or less, 53.0% or less, 52.0% or less, 51.0% or less, 50.0% or less, 49.0% or less, 48.0% or less, 46.0% or less, 45.0% or less, 44.0% or less, in this order.

[0108] In addition, from the viewpoint of suppressing volatilization and further improving the thermal stability of the glass, F - the content is preferably 60.0% or less, more preferably 59.0% or less, and is further preferably 58.0% or less, 57.0% or less, 56.0% or less, 55.0% or less, 54.0% or less, 53.0% or less, 52.0% or less, 51.0% or less, 50.0% or less, 49.0% or less, 48.0% or less, 46.0% or less, 45.0% or less, 44.0% or less, in this order.

[0109] From the viewpoint of suppressing an increase in Tg, O 2- the content is 83.0% or less, and is preferably 82.0% or less, and is more preferably 81.0% or less, 80.0% or less, 79.0% or less, 78.0% or less, 77.0% or less, 76.0% or less, 75.0% or less, 74.0% or less, 73.0% or less, 72.0% or less, in this order.

[0110] In addition, O 2- the content can be 0.0%, 0.0% or more, or more than 0.0%. From the viewpoint of high refractive index and further improving the thermal stability of the glass, O 2-The content is preferably 40.0% or more, more preferably 41.0% or more, and is further preferably 42.0% or more, 43.0% or more, 44.0% or more, 45.0% or more, 46.0% or more, 47.0% or more, 48.0% or more, 49.0% or more, 50.0% or more, 51.0% or more, 52.0% or more, 53.0% or more, or 55.0% or more in order.

[0111] As the anion component other than the above, for example, CI - , Br - , and I - may be exemplified.

[0112] The CI - content may be, for example, 0.0%, 0.0% or more, more than 0.0%, 0.10% or more, or 0.20% or more, and may be, for example, 5.0% or less, 4.0% or less, 3.0% or less, 2.0% or less, 1.0% or less, or 0.50% or less.

[0113] The Br - content may be, for example, 0.0%, 0.0% or more, more than 0.0%, 0.10% or more, or 0.20% or more, and may be, for example, 5.0% or less, 4.0% or less, 3.0% or less, 2.0% or less, 1.0% or less, or 0.5% or less.

[0114] The I - content may be, for example, 0.0%, 0.0% or more, more than 0.0%, 0.10% or more, or 0.20% or more, and may be, for example, 5.0% or less, 4.0% or less, 3.0% or less, 2.0% or less, 1.0% or less, or 0.5% or less.

[0115] <Physical properties of glass>

[0116] (Abbe number vD)

[0117] The Abbe number vd as an index of dispersion is represented by the respective refractive indexes nd, nF, nC under d-line, F-line, C-line as vd = (nd - 1) / (nF - nC). From the viewpoint of usefulness as a material for optical elements, the Abbe number vd of the above optical glass is preferably 50.00 or more, more preferably 55.00 or more, further preferably 60.00 or more, 62.50 or more, 65.00 or more, 67.50 or more, 70.00 or more, 70.50 or more, 71.00 or more, 71.50 or more, 72.00 or more, 72.50 or more, 73.00 or more, in this order. In addition, the Abbe number vd of the above optical glass can be, for example, 82.00 or less. In a photographing optical system, a projection optical system, and the like, by combining lenses having different dispersions to make a cemented lens, chromatic aberration can be compensated, and miniaturization of the optical system can be achieved. Low dispersion is generally easily achieved by a plastic lens, and thus, an optical glass having low dispersion is useful as a material for optical elements constituting a photographing optical system, a projection optical system, and the like. The above optical glass can exhibit low dispersion by having the above glass composition.

[0118] (refractive index nd)

[0119] From the viewpoint of usefulness as a material for optical elements, the refractive index nd of the above optical glass can be, for example, 1.420 or more, 1.425 or more, 1.430 or more, 1.435 or more, 1.440 or more, 1.445 or more, 1.446 or more, 1.447 or more, 1.448 or more, 1.449 or more, 1.450 or more, and, for example, 1.510 or less, 1.505 or less, 1.500 or less, 1.4950 or less, 1.490 or less, 1.489 or less, 1.488 or less, 1.487 or less, 1.486 or less, 1.485 or less, 1.484 or less, 1.483 or less, 1.482 or less, in this order. In the present invention and the present specification, the "refractive index" means the "refractive index nd", and the refractive index nd means the refractive index at a wavelength of 587.56 nm.

[0120] (glass transition temperature Tg)

[0121] The optical glass described above, by having the aforementioned glass composition, can have a low glass transition temperature. The glass transition temperature Tg of the aforementioned optical glass is preferably 355°C or less, more preferably 350°C or less, and further preferably in the order of 340°C or less, 330°C or less, 320°C or less, 310°C or less, 300°C or less, 290°C or less, 280°C or less, 270°C or less, and 260°C or less. Furthermore, the glass transition temperature Tg of the aforementioned optical glass can, for example, be 150°C or more, 160°C or more, 170°C or more, 180°C or more, 190°C or more, and 200°C or more. The glass transition temperature Tg is determined by the method described later.

[0122] (proportion)

[0123] From the viewpoint of reducing the weight of optical components, it is preferable that the optical glass has a low specific gravity. The specific gravity of the optical glass can be, for example, 3.10 or less, 3.05 or less, 3.00 or less, 2.95 or less, 2.90 or less, or 2.85 or less. Furthermore, the specific gravity of the optical glass can be, for example, 2.53 or more; the lower the specific gravity, the more preferred. Therefore, there is no particular limitation on the lower limit.

[0124] (Transmittance characteristics)

[0125] The aforementioned optical glass exhibits an external transmittance of 80% or more when converted to a thickness of 10.0 mm within the wavelength range of 500 nm to 1000 nm. "An external transmittance of 80% or more when converted to a thickness of 10.0 mm within the wavelength range of 500 nm to 1000 nm" means that the external transmittance converted to a thickness of 10.0 mm is 80% or more but less than 100% within the entire wavelength range of 500 nm to 1000 nm. Optical glass with this transmittance characteristic is useful as a material for optical components. For example, by manufacturing it without Cu... 2+ Glass with cationic components can achieve the aforementioned transmittance characteristics.

[0126] The transmittance characteristics of the glass described above were determined using the following method.

[0127] The glass sample was processed into a plane with parallel surfaces that had been optically polished, and the external transmittance was measured at wavelengths of 500–1000 nm. The external transmittance also includes the light reflection loss at the sample surface.

[0128] In addition, if the glass being measured is not the glass of the thickness to be converted, the thickness of the glass can be set as d, and the transmittance at each wavelength λ can be converted using the following formula A, and the transmittance characteristics can be obtained through the conversion.

[0129] Equation A: T(λ)=(1-R(λ)) 2 ×exp(log e ((T0(λ) / 100) / (1-R(λ)) 2 )×d / d0)×100

[0130] In Equation A, T(λ): converted transmittance at wavelength λ (%), T0(λ): measured transmittance at wavelength λ (%), d: converted thickness (mm), d0: glass thickness (mm), R(λ)=((n(λ)-1) / (n(λ)+1)) 2 Let n(λ) represent the reflectance at wavelength λ, and n(λ) represent the refractive index at wavelength λ. The refractive index n(λ) at wavelength λ is determined according to Japanese Industrial Standard (JIS) JISB 7071-1 "Method for Determination of Refractive Index of Optical Glass - Part 1: Minimum Deflection Angle Method" for each wavelength.

[0131] <Methods for Manufacturing Optical Glass>

[0132] The aforementioned optical glass can be obtained as follows: Phosphates, fluorides, oxides, carbonates, sulfates, nitrates, hydroxides, etc., are weighed and mixed as raw materials to obtain the desired glass composition. This mixture is thoroughly mixed to form a masterbatch, which is then heated, melted, degassed, and stirred in a melting vessel to produce a uniform, bubble-free molten glass. This molten glass is then shaped to obtain the optical glass. Specifically, a known melting method can be used for its production.

[0133] [Glass raw materials for pressure forming, optical component blanks, and their manufacturing methods]

[0134] Another embodiment of the present invention relates to:

[0135] Glass raw materials for pressure forming of the aforementioned optical glass; and

[0136] Optical component blanks containing the aforementioned optical glass.

[0137] According to another embodiment of the present invention, the following is also provided:

[0138] A method for manufacturing glass raw materials for pressure forming, comprising the process of forming the aforementioned optical glass into glass raw materials for pressure forming;

[0139] A method for manufacturing optical component blanks, comprising the step of pressurizing the aforementioned glass raw material for pressurizing optical glass using a pressurizing mold to produce optical component blanks; and

[0140] A method for manufacturing optical element blanks, comprising the process of forming the aforementioned optical glass into optical element blanks.

[0141] The optical element blank refers to an optical element mother material that has a shape similar to that of the target optical element, and has a polishing material (a surface layer that will be removed by polishing) added to the shape of the optical element, and a grinding material (a surface layer that will be removed by grinding) added as necessary. The optical element is finished by grinding and polishing the surface of the optical element blank. In one embodiment, the optical element blank can be produced by a method in which a molten glass obtained by melting an appropriate amount of the above-described glass is press-formed (referred to as a direct press method). In another embodiment, the optical element blank can also be produced by solidifying a molten glass obtained by melting an appropriate amount of the above-described glass.

[0142] In addition, in another embodiment, the optical element blank can be produced by producing a press-forming glass raw material, and press-forming the produced press-forming glass raw material.

[0143] The press-forming of the press-forming glass raw material can be performed by a known method in which the press-forming glass raw material that is heated to a softened state is pressurized using a press-forming mold. Both heating and press-forming can be performed in the atmosphere. By performing annealing after press-forming to reduce the strain in the glass, a uniform optical element blank can be obtained.

[0144] As the press-forming glass raw material, in addition to a raw material that is referred to as a press-forming glass gob, which is maintained in its original state and directly supplied to press-forming for producing an optical element blank, there is also a raw material that is subjected to mechanical processing such as cutting, grinding, and polishing, and is supplied to press-forming after the press-forming glass gob. As a cutting method, there are methods in which a groove is formed on a portion to be cut on the surface of a glass sheet by a method referred to as scribing, a local pressure is applied to the portion of the groove from the back surface of the one surface on which the groove is formed, and the glass sheet is cut at the portion of the groove; a method in which a glass sheet is cut using a cutting knife; and the like. In addition, as a grinding and polishing method, there are barrel polishing and the like.

[0145] The press-forming glass raw material can be produced, for example, by casting a molten glass into a mold and forming a glass sheet, and cutting the glass sheet into a plurality of glass pieces. Alternatively, an appropriate amount of molten glass can be formed to produce a press-forming glass gob. The optical element blank can also be produced by reheating and softening the press-forming glass gob, and performing press-forming. The method in which the glass is reheated and softened, and press-formed to produce an optical element blank is referred to as a reheat press method, as opposed to the direct press method.

[0146] [Optical element and method for manufacturing the same]

[0147] Another embodiment of the present application relates to:

[0148] An optical element comprising the optical glass described above.

[0149] The optical element described above is produced using the optical glass described above. In the optical element described above, one or more coating layers such as a multilayer film such as an antireflection film or the like can be formed on the surface of the glass.

[0150] In addition, according to one embodiment of the present application, it is also possible to provide:

[0151] A method for producing an optical element including a step of producing an optical element by grinding and / or polishing the optical element blank described above.

[0152] In the method for producing an optical element described above, the mechanical processing such as grinding, polishing, and the like can be performed using a known method, and by sufficiently washing and drying the surface of the optical element after processing, an optical element having high internal and surface quality can be obtained. In this way, an optical element formed of the optical glass described above can be obtained. As the optical element, various lenses such as a spherical lens, an aspherical lens, a microlens, a prism, and the like can be exemplified.

[0153] In addition, the optical element formed of the optical glass described above is also suitable for use as a lens constituting a bonded optical element. As the bonded optical element, an element in which lenses are bonded to each other (bonded lens), an element in which a lens and a prism are bonded, and the like can be exemplified. For example, a bonded optical element can be produced by precisely processing (for example, spherical polishing processing) the bonding surfaces of two optical elements to be bonded in such a manner that the shapes thereof become reversed shapes, applying an ultraviolet-curable adhesive for bonding the lenses, making them adhere, and then irradiating ultraviolet rays through the lenses to cure the adhesive, thereby producing a bonded optical element. A plurality of elements to be bonded can be respectively produced using a plurality of glasses having different Abbe numbers vD, and bonded, thereby producing an element suitable for compensating for chromatic aberration.

[0154] Example

[0155] Hereinafter, the present application will be described in more detail with reference to examples. However, the present application is not limited to the embodiments shown in the examples.

[0156] [Example 1]

[0157] <Sample Nos. 1 to 63>

[0158] In such a manner that the glass compositions shown in the following table are obtained, respective phosphates, fluorides, nitrates, sulfates, carbonates, hydroxides, oxides, boric acids, and the like were used as raw materials for introducing each component, the raw materials were weighed, and thoroughly mixed, and the raw materials were prepared.

[0159] The blending raw material was put into a platinum crucible, heated in a furnace set to 700 to 1100°C, and melted for 90 minutes. After homogenizing the molten glass by stirring, the molten glass was cast into a preheated mold, and immediately after naturally cooling to the vicinity of the glass transition temperature, was put into an annealing furnace, and kept at a temperature around the glass transition temperature for about 30 minutes, and then slowly cooled at a rate of -30°C / hour for 4 hours, and then naturally cooled to room temperature in the furnace, whereby each optical glass of Sample Nos. 1 to 63 shown in the following table was obtained.

[0160] [Comparative Example A, Comparative Example B]

[0161] The respective phosphates, fluorides, nitrates, sulfates, carbonates, hydroxides, oxides, boric acid, etc. were used as raw materials for introducing the respective components in such a manner as to become the glass compositions shown in the following table, the raw materials were weighed and mixed well, and a blending raw material was prepared.

[0162] The blending raw material was put into a platinum crucible, heated in a furnace set to 700 to 1100°C, and melted for 90 minutes. After homogenizing the molten glass by stirring, the molten glass was cast into a preheated mold, and immediately after naturally cooling to the vicinity of the glass transition temperature, was put into an annealing furnace, and kept at a temperature around the glass transition temperature for about 30 minutes, and then slowly cooled at a rate of -30°C / hour for 4 hours, and then naturally cooled to room temperature in the furnace, whereby each optical glass of Sample Nos. 1 to 63 shown in the following table was obtained.

[0163] <Physical Property Evaluation>

[0164] Each physical property of each optical glass shown in the following table was measured by the following method.

[0165] (1) Refractive Index nd, Abbe Number vd

[0166] For each optical glass, the refractive index ndand Abbe number vdwere measured by the refractive index measurement method of the Japan Optical Glass Industrial Association Standard. With respect to Comparative Example A, since devitrification occurred in the glass, the refractive index ndand Abbe number vdcould not be measured.

[0167] (2) Glass Transition Temperature Tg

[0168] The glass was sufficiently pulverized with a mortar, and used as a sample. A platinum cell was used as a sample container. The glass transition temperature Tg was measured using a differential scanning calorimeter (DSC3300SA) manufactured by NETZSCH JAPAN Co., Ltd., at a temperature increase rate of 10°C / min.

[0169] (3) Specific gravity

[0170] The specific gravity was measured by the Archimedes method.

[0171] (4) Transmittance characteristics

[0172] A test piece was cut from the obtained glass, mirror-polished on both surfaces, and processed to have mutually parallel and optically polished surfaces, so that the thickness reached 10.0 mm. The external transmittance at a wavelength of 500 to 1000 nm was measured using a spectrophotometer.

[0173] The external transmittance at a wavelength of 500 to 1000 nm was confirmed to be 80% or more and 100% or less at a thickness of 10.0 mm in any of Examples of Sample Nos. 1 to 63, Comparative Example A, and Comparative Example B.

[0174] <Thermal stability evaluation>

[0175] For Sample Nos. 1 to 63, Comparative Example A, and Comparative Example B, each of the raw materials for introducing each component was weighed out, and the raw materials were mixed to prepare a raw material mixture, in such a manner that the glass composition shown in the following table was obtained.

[0176] The raw material mixture was placed in a platinum crucible, and heated in a furnace set to a temperature of 700 to 1100°C for 90 minutes to melt the raw material mixture. The molten glass was homogenized by stirring, and then cast into a mold to form a glass sample.

[0177] The obtained glass sample was observed for crystals in the glass by optical microscopy. The magnification of the optical microscope was set to 40 to 100 times. In the case where no crystals were confirmed in the glass block, A was determined. In the case where one or more and less than 15 crystals were confirmed, B was determined. In the case where 16 or more and less than 40 crystals were confirmed, C was determined. In the case where 40 or more crystals were confirmed, D was determined. 3 In the case where no crystals were confirmed in the glass block, A was determined. In the case where one or more and less than 15 crystals were confirmed, B was determined. In the case where 16 or more and less than 40 crystals were confirmed, C was determined. In the case where 40 or more crystals were confirmed, D was determined. 3 In the case where no crystals were confirmed in the glass block, A was determined. In the case where one or more and less than 15 crystals were confirmed, B was determined. In the case where 16 or more and less than 40 crystals were confirmed, C was determined. In the case where 40 or more crystals were confirmed, D was determined. 3If more than 40 crystals are confirmed, the glass is classified as D. Regarding A, B, and C, thermal stability increases in the order C→B→A, with A having the highest thermal stability. If the order is A, B, and C, then the number of crystals in the glass is within an acceptable range for internal quality during manufacturing. Glass classified as D lacks thermal stability and is considered to have poor internal quality during manufacturing.

[0178] As shown in the table below, the glass samples No. 1 to 63 were confirmed to have excellent thermal stability (judgment result A, B or C).

[0179] [Table 1-11]

[0180]

[0181] [Table 1-2]

[0182]

[0183] [Table 1-3]

[0184]

[0185] [Table 1-4]

[0186]

[0187] [Table 1-5]

[0188]

[0189] [Table 1-6]

[0190]

[0191] [Table 1-7]

[0192]

[0193] [Table 2-1]

[0194]

[0195] [Table 2-2]

[0196]

[0197] [Table 2-3]

[0198]

[0199] [Table 2-4]

[0200]

[0201] [Table 2-5]

[0202]

[0203] [Table 2-6]

[0204]

[0205] [Table 2-7]

[0206]

[0207] [Table 3-1]

[0208]

[0209] [Table 3-2]

[0210]

[0211] [Table 3-3]

[0212]

[0213] [Table 3-4]

[0214]

[0215] [Table 3-5]

[0216]

[0217] [Table 3-6]

[0218]

[0219] [Table 3-7]

[0220]

[0221] (Example 2)

[0222] Using the various glasses obtained in Example 1, glass blocks (glass goblets) for press molding were prepared. The glass goblets were heated and softened in the atmosphere, and press molded using a press molding mold, to prepare lens blanks (optical element blanks). The prepared lens blanks were taken out of the press molding mold, annealed, and subjected to machining including polishing, to prepare spherical lenses formed of the various glasses prepared in Example 1.

[0223] (Example 3)

[0224] The molten glass produced in Example 1 was press-formed using a pressure forming mold to produce a lens blank (optical element blank). The produced lens blank was removed from the pressure forming mold, annealed, and subjected to machining processes including polishing to produce spherical lenses formed from the various types of glass produced in Example 1.

[0225] (Example 4)

[0226] An annealing process was performed on the glass block (optical element blank) made by solidifying the molten glass produced in Example 1, followed by machining including polishing, to produce spherical lenses formed from various types of glass produced in Example 1.

[0227] Finally, the above implementation methods are summarized.

[0228] [1] An optical glass having, in a glass composition expressed as cations%,

[0229] Li + The content exceeds 0.0% cations but is below 48.0% cations.

[0230] Na + The content exceeds 0.0% cations but is below 35.0% cations.

[0231] K + Content exceeding 0.0% cations and below 30.0% cations,

[0232] Al 3+ With P 5+ Total content (Al) 3+ +P 5+ The cation content is ≥38.0% and ≤70.0%

[0233] Among them, Li + Na + K + and Cs + The total content is set as R. + , will Be 2+ Mg 2+ Ca 2+ 、Sr 2+ And Ba 2+ The total content is set as R. 2+ ,

[0234] R + Compared to Al 3+ With P 5+ The total content of cation ratio (R) + / (Al 3+ +P 5+ The value of Li is above 0.93.+ Content relative to R + With R 2+ The total cation ratio (Li + / (R + +R 2+ The value is above 0.29.

[0235] Li + With K + The total content relative to Al 3+ With P 5+ The total content of cation ratio ((Li + +K + ) / (Al 3+ +P 5+ The value is above 0.56.

[0236] R 2+ Compared to Al 3+ Content and R 2+ The total cation ratio (R) 2+ / (Al 3+ +R 2+ The value is below 0.37.

[0237] In the glass composition expressed as anion %

[0238] O 2- The content is below 83.0% anion.

[0239] F - The content is above 19.0% anion.

[0240] Furthermore, the external transmittance of this optical glass at wavelengths of 500nm to 1000nm, converted to a thickness of 10.0mm, is over 80%.

[0241] [2] According to the optical glass described in [1], wherein,

[0242] Li + with Na + The total content relative to Li + With K + The total content of cation ratio ((Li + +Na + ) / (Li + +K + The value is above 0.50 and below 1.59.

[0243] [3] The optical glass according to [1] or [2], wherein,

[0244] Na + With K + The total content relative to Li+ the total content of K and Na is 0.05 or more and 2.00 or less. + + the total content of K and Na is 0.05 or more and 2.00 or less. + + the total content of K and Na is 0.05 or more and 2.00 or less. +

[0245] [4] The optical glass according to any one of [1] to [3], wherein

[0246] + + the total content of K and Na is 0.05 or more and 2.00 or less. + + the total content of K and Na is 0.05 or more and 2.00 or less. + + the total content of K and Na is 0.05 or more and 2.00 or less.

[0247] [5] The optical glass according to any one of [1] to [4], wherein

[0248] + + the total content of K and Na is 0.05 or more and 2.00 or less. + + the total content of K and Na is 0.05 or more and 2.00 or less. + + the total content of K and Na is 0.05 or more and 2.00 or less.

[0249] [6] The optical glass according to any one of [1] to [5], wherein

[0250] + + the total content of K and Na is 0.05 or more and 2.00 or less. + + the total content of K and Na is 0.05 or more and 2.00 or less. + + the total content of K and Na is 0.05 or more and 2.00 or less.

[0251] [7] The optical glass according to any one of [1] to [6], wherein

[0252] + + the total content of K and Na is 0.05 or more and 2.00 or less. + + the total content of K and Na is 0.05 or more and 2.00 or less. + + the total content of K and Na is 0.05 or more and 2.00 or less.

[0253] [8] The optical glass according to any one of [1] to [7], wherein the total content of K and Na is 0.05 or more and 2.00 or less.​​​​​​​​​​​​​​​​​​

[0254] Na + Content relative to Na + With K + The total content of cation ratio (Na) + / (Na + +K + The value is below 0.95.

[0255] [9] The optical glass according to any one of [1] to [8], wherein,

[0256] Na + Content relative to Li + With K + The total content of cation ratio (Na) + / (Li + +K + The value is below 1.00.

[0257]

[10] The optical glass according to any one of [1] to [9], wherein,

[0258] K + Content relative to K + With Li + The total content of cation ratio (K) + / (K + +Li + The value is above 0.01 and below 0.70.

[0259]

[11] The optical glass according to any one of [1] to

[10] , wherein,

[0260] K + Content relative to K + with Na + The total content of cation ratio (K) + / (K + +Na + The value is above 0.10 and below 0.80.

[0261]

[12] The optical glass according to any one of [1] to

[11] , wherein,

[0262] K + Content relative to Li + with Na + The total content of cation ratio (K) + / (Li + +Na + The value is above 0.01 and below 1.00.

[0263]

[13] The optical glass according to any one of [1] to

[12] , wherein,

[0264] R 2+ Compared to Al 3+ The ratio of cations in the content (R) 2+ / Al 3+ The value is below 0.74.

[0265]

[14] The optical glass according to any one of [1] to

[13] has a glass transition temperature Tg of 150°C or higher and 355°C or lower.

[0266]

[15] The optical glass according to claim 1, wherein,

[0267] Li + with Na + The total content relative to Li + With K + The total content of cation ratio ((Li + +Na + ) / (Li + +K + The value is above 0.50 and below 1.59.

[0268] Na + With K + The total content relative to Li + With K + The total content of cations (Na) + +K + ) / (Li + +K + The value is above 0.05 and below 2.00.

[0269] Li + Content relative to Li + with Na + The total content of cation ratio (Li + / (Li + +Na + The value is above 0.05 and below 1.00.

[0270] Li + Content relative to Li + With K + The total content of cation ratio (Li + / (Li + +K + The value is above 0.30 and below 0.99.

[0271] Li + Content relative to Na + With K + The total content of cation ratio (Li+ (Na + +K + )) is 0.10 or more and 5.00 or less,

[0272] Na + content relative to the total content of Na + and Li + cations (Na + / (Na + + Li + )) is 0.85 or less,

[0273] Na + content relative to the total content of Na + and K + cations (Na + / (Na + + K + )) is 0.95 or less,

[0274] Na + content relative to the total content of Li + and K + cations (Na + / (Li + + K + )) is 1.00 or less,

[0275] K + content relative to the total content of K + and Li + cations (K + / (K + + Li + )) is 0.01 or more and 0.70 or less,

[0276] K + content relative to the total content of K + and Na + cations (K + / (K + + Na + )) is 0.10 or more and 0.80 or less,

[0277] K + content relative to the total content of Li + and Na + cations (K + / (Li + + Na + )) is 0.01 or more and 1.00 or less,

[0278] R 2+ relative to Al 3+the content of the cationic ions (R 2+ / Al 3+ ) is 0.74 or less,

[0279] Further, the glass transition temperature Tg of the optical glass is 150°C or higher and 355°C or lower.

[0280]

[16] An optical element comprising the optical glass according to any one of [1] to

[15] .

[0281] It should be understood that the embodiments disclosed herein are all examples and do not constitute limitation. The scope of the present application is defined by the claims, not the above description, and is intended to include all modifications within the meaning and range equivalent to the claims.

[0282] For example, for the above-described example of the glass composition, by performing the composition adjustment described in the specification, the optical glass of one embodiment of the present application can be obtained.

[0283] In addition, of course, any two or more of the matters exemplified in the specification or described as a preferred range can be combined.

Claims

1. An optical glass, which, in a glass composition expressed in cations, Li + 0.0 cation % or more and 48.0 cation % or less, Na + 0.0 cation % or more and 35.0 cation % or less, K + more than 0.0 cation % and 30.0 cation % or less, Al 3+ with P 5+ together (Al 3+ + P 5+ ) is 38.0 cation% or more and 70.0 cation% or less, wherein, The total content of Li + , Na + , K + , and Cs + is set as R + , and the total content of Be 2+ , Mg 2+ , Ca 2+ , Sr 2+ , and Ba 2+ is set as R 2+ , R + Relative to Al 3+ With P 5+ The total content of cations (R + / (Al 3+ + P 5+ )) is 0.93 or more, Li + content relative to R + total of R 2+ and R + ((Li + + R 2+ )) is 0.29 or more, Li + With the total content of K + The cation ratio ((Li 3+ + K 5+ ) / (Al + + P + )) of the total content of Li 3+ and P 5+ is 0.56 or more, R 2+ Relative to Al 3+ Content and R 2+ The total of the cation ratio (R 2+ / (Al 3+ +R 2+ )) is 0.37 or less, R + with respect to Al 3+ (R + / Al 3+ ) is 0.50 or less, Li + the total content of Na + the total content of Na + the total content of K + the cation ratio ((Li + + Na + ) / (Li + + K + )) is 0.50 or more and 1.59 or less, in a glass composition expressed in anions, O 2- 83.0% or less by weight of anions, F - a content of 19.0 anion% or more, and, the optical glass has a refractive index nd of 1.500 or less, and an external transmittance at a wavelength of 500 nm to 1000 nm, converted into a thickness of 10.0 mm, of 80% or more.

2. The optical glass according to claim 1, wherein Li + the total content of Na + the total content of Na + the total content of K + the cation ratio ((Li + + Na + ) / (Li + + K + )) is 0.60 or more, 0.70 or more, or 0.75 or more, and / or, Na + With K + The total content relative to Li + With K + The total content of cations (Na) + +K + ) / (Li + +K + The values ​​are 0.05 or higher, 0.09 or higher, 0.15 or higher, 0.19 or higher, and / or, less than 2.00, less than 1.85, less than 1.70 or less than 1.38, and / or, Li + Content relative to Li + with Na + The total content of cation ratio (Li + / (Li + +Na + The values ​​are 0.05 or higher, 0.10 or higher, 0.25 or higher, or 0.35 or higher, and / or, less than 1.00, less than 0.98, less than 0.93, or less than 0.89, and / or, Li + Content relative to Li + With K + The total content of cation ratio (Li + / (Li + +K + The values ​​are 0.30 or higher, 0.40 or higher, 0.46 or higher, or 0.54 or higher, and / or, 0.99 or lower, 0.97 or lower, 0.94 or lower, or 0.91 or lower, and / or, Li + Content relative to Na + With K + The total content of cation ratio (Li + / (Na + +K + The values ​​are 0.10 or higher, 0.20 or higher, 0.30 or higher, or 0.42 or higher, and / or, 5.00 or lower, 4.90 or lower, 4.70 or lower, or 4.40 or lower, and / or, Na + Content relative to Na + With Li + The total content of cation ratio (Na) + / (Na + +Li + Values ​​exceeding 0.00, 0.03 or higher, 0.06 or higher, or 0.10 or higher, and / or values ​​below 0.85, 0.75, 0.70 or lower, or 0.66 or lower, and / or Na + the content of Na + The content of Na + The ratio of cations (Na + / (Na + + K + )) is more than 0.00, 0.15 or more, 0.20 or more, or 0.30 or more, and / or, 0.95 or less, 0.89 or less, 0.83 or less, or 0.79 or less, and / or, Na + Content relative to Li + With K + The total content of cation ratio (Na) + / (Li + +K + Values ​​exceeding 0.00, 0.03 or higher, 0.07 or higher, or 0.10 or higher, and / or values ​​below 1.00, 0.98 or lower, 0.92 or lower, or 0.90 or lower, and / or K + Content relative to K + With Li + The total content of cation ratio (K) + / (K + +Li + The values ​​are 0.01 or higher, 0.03 or higher, 0.07 or higher, or 0.09 or higher, and / or, less than 0.70, less than 0.65, less than 0.52, or less than 0.44, and / or, K + Content relative to K + with Na + The total content of cation ratio (K) + / (K + +Na + The values ​​are 0.10 or higher, 0.12 or higher, 0.16 or higher, or 0.19 or higher, and / or, 0.80 or lower, 0.77 or lower, 0.73 or lower, or 0.68 or lower, and / or, K + Content relative to Li + with Na + The total content of cation ratio (K) + / (Li + +Na + The values ​​are 0.01 or higher, 0.03 or higher, 0.05 or higher, or 0.08 or higher, and / or, less than 1.00, less than 0.90, less than 0.70 or less than 0.50, and / or, R 2+ Compared to Al 3+ The ratio of cations in the content (R) 2+ / Al 3+ ) is greater than or equal to 0.00 or greater than 0.005, and / or is less than or equal to 0.

40.

3. The optical glass according to claim 1 or 2, wherein Na + With K + The total content relative to Li + With K + The total content of cations (Na) + +K + ) / (Li + +K + The value is above 0.05 and below 2.

00. Li + content relative to Li + + cations (Li + / (Li + + Na + )) is 0.05 or more and 1.00 or less,​ Li + the content of Li + The content of Li + The content of Li + The content of Li + The content of Li + 0.30 or more and 0.99 or less, Li + the content of Na + + the content of K + + the content of Na + + K) is 0.10 or more and 5.00 or less,​​ Na + content relative to Na + The cation ratio (Na + / (Na + + Li + )) of the total content of Na + and Li + is more than 0.00 and 0.85 or less, Na + content relative to Na + The cation ratio (Na + / (Na + +K + )) of the total content of Na + and K + is more than 0.00 and 0.95 or less, Na + content relative to Li + content of K + The ratio of the cation content (Na + / (Li + + K + )) to the total content of K + and Li + is more than 0.00 and 1.00 or less. K + Content relative to K + With Li + The total content of cation ratio (K) + / (K + +Li + The value is above 0.01 and below 0.

70. K + Content relative to K + with Na + The total content of cation ratio (K) + / (K + +Na + The value is above 0.10 and below 0.

80. K + the content of Li + The total content of Na + The total content of Na + The total content of Na + The total content of Na + The total content of Na and, the optical glass has a glass transition temperature Tg of 150°C or more and 355°C or less.

4. The optical glass according to claim 1 or 2, wherein P 5+ from 9.0 cation% or more, 16.0 cation% or more, or 20.0 cation% or more, and / or, 48.0 cation% or less, 42.0 cation% or less, or 37.0 cation% or less, and / or, Al 3+ from 2.0% or 6.0% and / or 30.0 cations% or 28.0 cations% or 26.0 cations%.

5. The optical glass according to claim 1 or 2, wherein Li + from 2.0 cation % or more, 6.0 cation % or more, or 10.0 cation % or more, and / or, 47.0 cation % or less, 46.0 cation % or less, or 45.0 cation % or less, and / or, Na + 1.0 cation % or more, 2.0 cation % or more, or 3.0 cation % or more, and / or, 34.0 cation % or less, 31.0 cation % or less, or 28.0 cation % or less, and / or, K + 1.0 cation % or more or 3.0 cation % or more, and / or, 30.0 cation % or less, 27.0 cation % or less, or 23.0 cation % or less.

6. The optical glass according to claim 1 or 2, wherein O 2- anionic content of 40.0% or more, 45.0% or more, or 50.0% or more, and / or an anionic content of 80.0% or less, 76.0% or less, or 74.0% or less, and / or, F - the content is 21.0% or more, 23.0% or more, or 25.0% or more, and / or is 60.0% or less, 55.0% or less, or 50.0% or less.

7. The optical glass according to claim 1 or 2, wherein Al 3+ with P 5+ in a total content (Al 3+ + P 5+ ) of 38.4 cation% or more, 38.8 cation% or more, or 39.0 cation% or more, and / or, 65.0 cation% or less, 60.0 cation% or less, or 55.0 cation% or less, and / or, R + Relative to Al 3+ With P 5+ The total content of cations (R + / (Al 3+ + P 5+ )) is 0.94 or more, or 0.95 or more, and / or, is 2.75 or less, 2.25 or less, or 1.80 or less, and / or, Li + the content of Li relative to R + the content of Li relative to R 2+ the content of Li relative to R + / (R + +R 2+ )) is 0.30 or more, or 0.31 or more, and / or, is 1.00 or less, 0.92 or less, or 0.87 or less, and / or, Li + With K + the total content of Al 3+ With P 5+ the cation ratio ((Li + + K + ) / (Al 3+ + P 5+ )) is 0.64 or more, and / or, 2.00 or less, 1.70 or less, or 1.40 or less, R 2+ Relative to Al 3+ Content and R 2+ The total of the cations (R 2+ / (Al 3+ +R 2+ )) is 0.00 or more or 0.01 or more, and / or, is 0.34 or less or 0.31 or less, and / or, Li + Na + K + and Cs + in total content R + is 25.0 cations% or more, 35.0 cations% or more, or 48.0 cations% or more, and / or, is 65.0 cations% or less, 64.0 cations% or less, or 63.0 cations% or less, and / or, Be 2+ , Mg 2+ , Ca 2+ , Sr 2+ , and Ba 2+ . The total content R 2+ of the above-mentioned cations is 19.0 cation% or less, 15.0 cation% or less, or 8.0 cation% or less.

8. The optical glass according to claim 1 or 2, which has a glass transition temperature Tg of 150°C or more and 355°C or less.

9. The optical glass according to claim 1 or 2, which has a refractive index nd of 1.420 or more, 1.430 or more, or 1.440 or more, and / or, 1.485 or less.

10. The optical glass according to claim 1 or 2, which has an Abbe number vd of 50.00 or more, or 55.00 or more.

11. An optical member comprising the optical glass according to any one of claims 1 to 10.

Images