Optical glass and optical element

Abstract

The present invention provides an optical glass and an optical element which have a desired optical constant, are suppressed in chemical durability and mechanical property reduction, and have a low glass transition temperature. In the optical glass, the content of B < 3 + > is more than 0 cation% but 50.00 cation% or less, the content of F <-> is more than 0 anion%, the glass transition temperature Tg is 625 DEG C or less, the Knoop hardness is 450 or more, the [Delta] Pg, F is-0.0025 or more, the Abbe number vd is 37.5 or more, and the refractive index nd and the Abbe number vd satisfy the following formula: nd > =-0.0081 * vd + 2.1181.

Description

Technical Field

[0001] The present invention relates to optical glass and optical elements having desired optical properties. Background Art

[0002] Lenses with high refractive index and anomalous partial dispersion in each Abbe region have been widely used in digital cameras such as car cameras and single-lens reflex cameras, as well as mobile information terminals such as smart phones. In order to improve the yield rate during lens manufacturing in these applications, it is desirable that the glass have high chemical durability and mechanical properties. In addition, for example, when processing glass into aspheric lenses, processing sometimes becomes difficult for glass with a high glass transition temperature. Therefore, glass with a lower glass transition temperature is required.

[0003] Patent Document 1 discloses an optical glass having a high refractive index and anomalous partial dispersion in the visible to near-ultraviolet region. Patent Document 2 also discloses an optical glass having a high refractive index and high transmittance in the near-infrared region. However, neither Patent Document 1 nor Patent Document 2 addresses the improvement of mechanical properties.

[0004] Therefore, there is a demand for glass having chemical durability, a low glass transition temperature, a high refractive index, and abnormal partial dispersion while also having mechanical properties.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2016-155745

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2017-19670

[0009] Summary of the Invention

[0010] Problems to be solved by the invention

[0011] The present invention has been made in view of such actual circumstances, and an object thereof is to provide an optical glass and an optical element having desired optical constants, with reduced degradation of chemical durability and mechanical properties, and with a low glass transition temperature.

[0012] Solutions to the Problem

[0013] The gist of the present invention is as follows.

[0014] (1) An optical glass, wherein:

[0015] B 3+ The content of cations is greater than 0% and less than 50.00%.

[0016] F - The content of anions is greater than 0%,

[0017] The glass transition temperature Tg is below 625°C.

[0018] Knoop hardness is above 450.

[0019] ΔPg,F is -0.0025 or more,

[0020] The Abbe number νd is 37.5 or more,

[0021] The refractive index nd and the Abbe number νd satisfy the following formula:

[0022] nd≥-0.0081×νd+2.1181.

[0023] (2) The optical glass according to (1), wherein

[0024] Si 4+ The content of cationic ions is less than 30%,

[0025] Li + The content of cationic ions is less than 30%,

[0026] Na + The content of cationic ions is less than 30%,

[0027] K + The content of cationic ions is less than 30%,

[0028] Mg 2+ The content of cationic ions is less than 25%,

[0029] Ca 2+ The content of cationic ions is less than 25%,

[0030] Sr 2+ The content of cationic ions is less than 25%,

[0031] Ba 2+ The content of cationic ions is less than 25%,

[0032] Zn 2+ The content of cationic ions is less than 25%,

[0033] La 3+ The content of cationic ions is less than 50%,

[0034] Y 3+ The content of cationic ions is less than 50%,

[0035] Gd 3+ The content of cationic ions is less than 30%,

[0036] Zr4+ The content of cationic ions is less than 15%,

[0037] Ta 5+ The content of cationic ions is less than 15%,

[0038] Ti 4+ The content of cationic ions is less than 15%,

[0039] Nb 5+ The content of cationic ions is less than 15%,

[0040] W 6+ The content of cationic ions is less than 15%,

[0041] Bi 3+ The content of cationic ions is less than 15%,

[0042] Ge 4+ The content of cationic ions is less than 5%,

[0043] Li + 、Na + , K + , Rb + 、Cs + Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ The total content [Li + +Na + +K + +Rb + +Cs + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ] is greater than 0 cation % and less than 50 cation %,

[0044] La 3+ 、Gd 3+ and Y 3+ The total content [La 3+ +Gd 3+ +Y 3+ ] is greater than 0 cation % and less than 70 cation %,

[0045] La 3+ 、Gd 3+ 、Y 3+ 、Li + 、Na + , K + , Rb + 、Cs + Mg 2+ , Ca2+ 、Sr 2+ And Ba 2+ Total content relative to Si 4+ 、B 3+ 、P 5+ 、Ti 4+ 、Nb 5+ 、W 6+ 、Bi 3+ 、Zr 4+ and Ta 5+ The total cation content ratio [(La 3+ +Gd 3+ +Y 3+ +Li + +Na + +K + +Rb + +Cs + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ) / (Si 4+ +B 3+ +P 5+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ +Zr 4+ +Ta 5+ )] is above 0.50.

[0046] (3) The optical glass according to (1), wherein the acid resistance Da is level 4 or higher.

[0047] (4) The optical glass according to (1), wherein the glass transition temperature Tg is 540° C. or lower.

[0048] (5) The optical glass according to (1), wherein

[0049] The content of Sb ions is 1.0 mass ppm or more in terms of added proportion.

[0050] (6) The optical glass according to (1), wherein

[0051] When the thickness is set to 10.0 mm±0.1 mm, the difference between the external transmittance at a wavelength of 700 nm and the external transmittance at a wavelength of 360 nm is 10% or less.

[0052] (7) The optical glass according to (1), wherein

[0053] When the thickness is set to 10.0 mm±0.1 mm, the difference between the external transmittance at a wavelength of 700 nm and the external transmittance at a wavelength of 375 nm is 7.5% or less.

[0054] (8) A glass material for press molding, which is made of the optical glass described in any one of (1) to (7) above.

[0055] (9) An optical element made of the optical glass described in any one of (1) to (7) above.

[0056] Effects of the Invention

[0057] According to the present invention, it is possible to provide an optical glass and an optical element having desired optical constants, in which degradation of chemical durability and mechanical properties is suppressed and in which the glass transition temperature is not high. DETAILED DESCRIPTION

[0058] In the embodiments of the present invention, unless otherwise specified, the glass composition of optical glass is expressed in terms of cation %. Cation % refers to the molar percentage when the total content of all cationic components is taken as 100%. Unless otherwise specified, the content and total content of glass components are based on cation %, and "%" refers to "cation %." Furthermore, the cation ratio refers to the ratio (ratio) of the contents of the respective cation components within the cation % (including the total content of multiple cation components).

[0059] In addition, anion % means the molar percentage when the total content of all anion components is set to 100%.

[0060] The valence of the cationic component (e.g. B 3+ The valence is +3, Si 4+ The valence is +4, La 3+ The valence of the glass is +3) is a value determined by convention. When expressing B, Si, and La as glass components based on oxides, it is the same as expressing them as B2O3, SiO2, and La2O3. Therefore, when analyzing glass composition, the valence of the cationic components can be ignored. In addition, the valence of the anionic components (such as O 2- The valence of the anion is -2) is also a value determined by convention. As mentioned above, the glass composition expressed on an oxide basis is the same as, for example, B2O3, SiO2, and La2O3. Therefore, when analyzing the glass composition, the valence of the anion component does not need to be analyzed.

[0061] The content of the glass component can be quantified by known methods, such as inductively coupled plasma atomic emission spectrometry (ICP-AES), inductively coupled plasma mass spectrometry (ICP-MS), ion chromatography (IC), non-dispersive infrared absorption spectrometry (ND-IR), etc. In this specification and the present invention, a content of a constituent component of 0% means that the constituent component is substantially not contained, but the presence of the constituent component at a level of unavoidable impurities is permitted.

[0062] In this specification, chemical durability refers to excellence in either or both of acid resistance Da and water resistance Dw. In addition, mechanical properties refer to excellence in the hardness of the glass as evaluated by the Knoop hardness Hk. The Knoop hardness Hk is an indicator of the indentation hardness of the glass. It should be noted that the unit of the Knoop hardness Hk is "MPa", but due to the convention of omitting the unit of the Knoop hardness Hk in the technical field to which the present invention belongs, the unit of the Knoop hardness Hk is also omitted in this specification. In addition, the thermal stability and reheating stability of the glass both refer to the ease with which crystals in the glass precipitate. Thermal stability refers to the ease with which crystals precipitate when molten glass solidifies, and reheating stability refers to the ease with which crystals precipitate when the solidified glass is reheated, such as during re-hot pressing.

[0063] In this specification, reducing or suppressing the volatilization of glass components means that the loss of glass components caused by the volatilization of glass components during melting is small or suppressed. If the loss of glass components caused by volatilization during melting is small, the fluctuation of various properties represented by the refractive index can be suppressed, and the generation of internal defects such as ribs inside the glass can be suppressed, so that the quality can be stabilized. In addition, by reducing the loss of glass components, the yield of the product relative to the input raw materials can be directly improved. On the other hand, the glass components that are easily volatilized during melting are components that help to reduce dispersion, improve the dispersion of abnormal parts, and lower the glass transition temperature Tg. Therefore, by suppressing the volatilization of these components, optical glass and optical elements with desired optical constants and low glass transition temperature Tg can be provided.

[0064] Unless otherwise specified, the refractive index refers to the refractive index nd under helium d-ray (wavelength 587.56 nm).

[0065] Hereinafter, the optical glass of the present invention will be described in detail.

[0066] In the optical glass of this embodiment,

[0067] B 3+ The content of cations is greater than 0% and less than 50.00%.

[0068] F - The content of anions is greater than 0%,

[0069] The glass transition temperature Tg is below 600°C.

[0070] Knoop hardness is above 450.

[0071] ΔPg,F is -0.0025 or more,

[0072] The refractive index nd and the Abbe number νd satisfy the following formula:

[0073] nd≥-0.0081×νd+2.1181.

[0074] In the optical glass of this embodiment, B 3+ The content of B is greater than 0% and less than 50.00%. 3+ The lower limit of the content of is preferably 5%, and more preferably 10%, 15%, 17%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, and 26%. 3+ The upper limit of the content is preferably 45.00%, and more preferably 40.00%, 39.00%, 38.00%, 37.00%, 36.00%, 35.00%, 34.00%, 33.00%, 32.00%, 31.00%, 30.00%, and 29.00%.

[0075] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, B 3+ The lower limit of the content of is preferably 5%, and more preferably 10%, 15%, 17%, 19%, 21%, 23%, 25%, 27%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%. 3+ The upper limit of the content is preferably 45.00%, and more preferably 44.00%, 43.00%, 42.50%, 42.00%, 41.50%, 41.00%, 40.50%, and 40.00%, in this order.

[0076] B 3+ It is a network forming component of glass. 3+ The chemical durability can be improved by setting the content of B to the above range. 3+ If the content of B is too low, there is a risk of reducing the thermal stability and mechanical properties of the glass. 3+ If the content of is too high, there is a risk of increased volatilization of glass components and a risk of decreased thermal stability and chemical durability of the glass.

[0077] The optical glass of this embodiment includes F - As anionic component, that is, F -The content of anion is greater than 0%. - The lower limit of the content of is preferably 5 anions, and further preferably 10 anions, 15 anions, 20 anions, 25 anions, 27 anions, 29 anions, 30 anions, 31 anions, 32 anions, 33 anions, 34 anions, 35 anions, 36 anions, 37 anions, 38 anions, 39 anions, 40 anions, 41 anions, 42 anions, 43 anions, and 44 anions. In addition, F - The upper limit of the content is preferably 80 anion%, and further preferably 75 anion%, 70 anion%, 65 anion%, 63 anion%, 61 anion%, 60 anion%, 59 anion%, 58 anion%, 57 anion%, 56 anion%, 55 anion%, 54 anion%, 53 anion%, 52 anion%, 51 anion%, 50 anion%, 49 anion%, 48 anion%, and 47 anion%.

[0078] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, F - The lower limit of the content of is preferably 15 anions, and more preferably 17 anions, 19 anions, 21 anions, 23 anions, 24 anions, 25 anions, 26 anions, 27 anions, 28 anions, 29 anions, 30 anions, and 31 anions. In addition, F - The upper limit of the content is preferably 80 anions, and further preferably 75 anions, 70 anions, 65 anions, 63 anions, 61 anions, 59 anions, 57 anions, 55 anions, 53 anions, 51 anions, 49 anions, 47 anions, 45 anions, 43 anions, 41 anions, 40 anions, 39 anions, 38 anions, 37 anions, 36 anions, and 35 anions.

[0079] By adding F - When the content of F is set within the above range, an optical glass having high refractive index, high thermal stability, abnormal partial dispersion, low glass transition temperature Tg, and suitable for precision press molding can be obtained despite having low dispersion. - If the content of F is too low, there is a risk that the thermal stability of the glass will be reduced, and there is a risk that the abnormal partial dispersion property cannot be obtained. - If the content is too high, there is a hidden danger of increased volatilization of glass components.

[0080] <Glass transition temperature Tg>

[0081] In the optical glass of this embodiment, the glass transition temperature Tg is 625°C or lower. The upper limit of the glass transition temperature Tg is preferably 620°C, and more preferably 610°C, 600°C, 590°C, 580°C, 570°C, 560°C, 550°C, 540°C, 530°C, 520°C, 510°C, 500°C, 490°C, and 480°C. The lower limit of the glass transition temperature Tg is preferably 350°C, and more preferably 360°C, 370°C, 380°C, 390°C, 400°C, 410°C, 420°C, 430°C, 440°C, 450°C, 460°C, and 470°C.

[0082] For optical glasses with a higher refractive index and higher dispersion, the upper limit of the glass transition temperature Tg is preferably 625°C, and more preferably 620°C, 615°C, 610°C, 595°C, 590°C, 585°C, and 580°C, respectively. Furthermore, the lower limit of the glass transition temperature Tg is preferably 350°C, and more preferably 360°C, 370°C, 380°C, 390°C, 400°C, 410°C, 420°C, 430°C, 440°C, 450°C, 460°C, 470°C, 480°C, 490°C, and 500°C, respectively.

[0083] By setting the glass transition temperature Tg to the above range, the yield rate during precision press molding can be improved. On the other hand, if the glass transition temperature Tg is too high, there is a hidden danger that precision press molding cannot be performed. The component that relatively lowers the glass transition temperature Tg is Li + 、Na + , K + 、F - The component that relatively increases the glass transition temperature Tg is La 3+ 、Zr 4+ 、Nb 5+ The glass transition temperature Tg can be controlled by appropriately adjusting the contents of these components.

[0084] <Mechanical properties Knoop hardness Hk>

[0085] In the optical glass of this embodiment, the Knoop hardness is not less than 450. The lower limit of the Knoop hardness Hk is preferably 460, and more preferably 470, 480, 490, 500, 510, and 520, respectively.

[0086] In addition, for optical glasses with higher refractive index and higher dispersion, the lower limit of the Knoop hardness Hk is preferably 400, and more preferably 410, 420, 430, 440, 450, 460, 470, 480, 490, 500, 510, 520, 530, 540, and 550, respectively.

[0087] The Knoop hardness Hk is preferably within the above range from the perspective of preventing damage when handling glass and performing mechanical processing such as grinding, lapping, and cutting on the glass to manufacture lenses. The upper limit of the Knoop hardness Hk is not particularly limited, but is generally 750, preferably 600.

[0088] Knoop hardness Hk can be adjusted by La 3+ 、Gd 3+ 、Y 3+ 、Si 4+ 、Zr 4+ 、Al 3+ to increase the content.

[0089] <ΔPg,F>

[0090] In the optical glass of this embodiment, ΔPg,F is not less than -0.0025. The lower limit of ΔPg,F is preferably -0.0020, and more preferably -0.0010, 0.0000, 0.0010, 0.0020, 0.0030, 0.0040, 0.0050, 0.0060, 0.0070, and 0.0080, respectively. The upper limit of ΔPg,F is not particularly limited, but is preferably 0.0500, and more preferably 0.0400, 0.0300, 0.0200, 0.0150, 0.0140, 0.0130, 0.0120, 0.0110, and 0.0100.

[0091] For optical glasses with higher refractive index and higher dispersion, the upper limit of ΔPg,F is not particularly limited, but is preferably 0.0500, and further preferably 0.0400, 0.0300, 0.0200, 0.0150, 0.0140, 0.0130, 0.0120, 0.0110, and 0.0100. On the other hand, the lower limit of ΔPg,F is preferably -0.0022, and further more preferably -0.0020, -0.0018, -0.0016, -0.0014, -0.0012, -0.0010, -0.0008, -0.0006, -0.0004, -0.0002, and 0.0000.

[0092] By setting ΔPg,F within the above range, an optical glass suitable for compensating for high-order chromatic aberrations can be obtained.

[0093] ΔPg,F can be calculated as follows based on the relative partial dispersion Pg,F. The relative partial dispersion Pg,F is calculated using the values ​​of the linear refractive indices obtained using the Schott dispersion equation described later.

[0094] The relative partial dispersion Pg,F is expressed as follows using the refractive indices ng, nF, and nC for g-rays, F-rays, and C-rays, respectively.

[0095] Pg,F=(ng-nF) / (nF-nC)

[0096] In a plane where the horizontal axis represents the Abbe number νd and the vertical axis represents the relative partial dispersion Pg,F, the normal line is expressed by the following equation.

[0097] Pg,F(0)=0.6483-(0.001802×νd)

[0098] Furthermore, the deviation ΔPg,F of the relative partial dispersion Pg,F from the normal line is expressed as follows.

[0099] ΔPg,F=Pg,F-Pg,F(0)

[0100] <Abbe number νd>

[0101] In the optical glass of this embodiment, the Abbe number νd is 37.5 or greater. The Abbe number νd may be 40-75, 50-70, 55-67, 57-65, 58-64, 59-63, or 56-60.

[0102] Furthermore, for optical glasses with a higher refractive index and higher dispersion, the Abbe number νd is preferably 37.5 to 60, and may be 40 to 58, 45 to 56, 47 to 54, 48 to 52, 49 to 51, or 55 to 59 or 56 to 58.

[0103] The Abbe number νd can be set to a desired value by appropriately adjusting the content of each glass component. The component that relatively reduces the Abbe number νd, that is, the high dispersion component, is Nb 5+ 、Ti 4+ 、Zr 4+ 、W 6+ 、Bi 3+ 、Ta 5+ On the other hand, the component that relatively increases the Abbe number νd, that is, the low dispersion component is F - 、Si 4+ 、B 3+ 、Li + 、Na + , K + 、La 3+ 、Ba 2+ , Ca 2+ 、Sr 2+ wait.

[0104] In the present invention, the Abbe number νd and the relative partial dispersion Pg,F are calculated as follows. Specifically, the refractive index at the 12 wavelengths shown in Table A is measured using the Japanese Industrial Standard (JIS) JIS B 7071-1, Optical Glass - Determination of the Refractive Index - Part 1: Minimum Deviation Angle Method. The refractive index of each ray obtained from the measurements is then substituted into the Schott dispersion equation specified in Appendix B of the Japanese Industrial Standard (JIS) JIS B 7071-1, Optical Glass - Determination of the Refractive Index - Part 1: Minimum Deviation Angle Method, and the constants of the Schott dispersion equation are determined using the least squares method. The Abbe number νd and the relative partial dispersion Pg,F are then calculated from the obtained refractive index values ​​for each ray using the Schott dispersion equation with the determined constants.

[0105]

[0106] Schott dispersion type: n 2 =a0+a1λ 2 +a2λ -2 +a3λ -4 +a4λ -6 +a5λ -8

[0107] Where n is the refractive index, λ is the wavelength (μm), and a0, a1, a2, a3, a4, and a5 are constants.

[0108] The Abbe number νd is expressed as follows using the refractive indices nd, nF, and nC under d-rays, F-rays, and C-rays, respectively.

[0109] νd=(nd-1) / (nF-nC)

[0110] <Refractive Index nd and Abbe Number νd>

[0111] In the optical glass of this embodiment, the refractive index nd and the Abbe number νd satisfy the following formula [1-1].

[0112] nd≥-0.0081×νd+2.1181 ···〔1-1〕

[0113] The refractive index nd and the Abbe number νd preferably satisfy the following formula [1-2], and more preferably satisfy the following formula [1-3], the following formula [1-4], and the following formula [1-5] in that order.

[0114] nd≥(-0.0081×νd+2.1231) ···〔1-2〕

[0115] nd≥(-0.0081×νd+2.1281) ···〔1-3〕

[0116] nd≥(-0.0081×νd+2.1331) ···〔1-4〕

[0117] nd≥(-0.0081×νd+2.1381) ···〔1-5〕

[0118] In addition, for optical glasses with a higher refractive index and higher dispersion, the refractive index nd and the Abbe number νd preferably satisfy the following formula [2-1].

[0119] nd≥(-0.0081×νd+2.1181) ···〔2-1〕

[0120] The refractive index nd and the Abbe number νd more preferably satisfy the following formula [2-2], and further more preferably satisfy the following formula [2-3], the following formula [2-4], and the following formula [2-5] in that order.

[0121] nd≥(-0.0081×νd+2.1231) ···〔2-2〕

[0122] nd≥(-0.0081×νd+2.1281) ···〔2-3〕

[0123] nd≥(-0.0081×νd+2.1331) ···〔2-4〕

[0124] nd≥(-0.0081×νd+2.1381) ···〔2-5〕

[0125] Hereinafter, non-limiting examples are shown regarding the contents of glass components other than those described above and glass properties in the optical glass of this embodiment.

[0126] In the optical glass of this embodiment, Si 4+ and B 3+ The total content [Si 4+ +B 3+ The lower limit of the total content is preferably 10%, and more preferably 15%, 20%, 22%, 24%, 26%, 28%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, and 37% in sequence. In addition, the upper limit of the total content is preferably 70%, and more preferably 65%, 60%, 58%, 56%, 54%, 52%, 50%, 48%, 47%, 46%, 45%, 44%, 43%, 42%, 41%, and 40% in sequence.

[0127] In addition, from the viewpoint of obtaining an optical glass with a higher refractive index and high dispersion, the total content [Si 4+ +B 3+The lower limit of the total content is preferably 10%, and more preferably 15%, 20%, 22%, 24%, 26%, 28%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, and 43% in sequence. In addition, the upper limit of the total content is preferably 70%, and more preferably 65%, 60%, 59%, 58%, 57%, 56%, 55%, 54%, 53%, 52%, 51%, 50%, 49%, 48%, 47%, 46%, and 45% in sequence.

[0128] From the viewpoint of obtaining an optical glass having desired optical constants and abnormal partial dispersion, improved chemical durability, mechanical properties and thermal stability, and suppressed volatilization of glass components during melting, it is preferred to reduce the total content of [Si 4+ +B 3+ ] is set to the above range.

[0129] In the optical glass of this embodiment, Li + 、Na + and K + The total content [Li + +Na + +K + The lower limit of the total content is preferably 0%, and more preferably 1%, 2%, 3%, 4%, 5%, and 6%. In addition, the upper limit of the total content is preferably 50%, and more preferably 45%, 40%, 35%, 30%, 25%, 20%, 18%, 16%, 14%, 13%, 12%, 11%, 10%, and 9%. The total content may be 0%.

[0130] In addition, from the viewpoint of maintaining the thermal stability of the glass in the optical glass with a higher refractive index and high dispersion, the total content [Li + +Na + +K + The lower limit of the total content is preferably 0%, and more preferably 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, and 0.6% in this order. In addition, the upper limit of the total content is preferably 50%, and more preferably 45%, 40%, 35%, 30%, 25%, 20%, 18%, 16%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, and 2% in this order.

[0131] From the viewpoint of lowering the liquidus temperature of the glass and lowering the glass transition temperature Tg, it is preferred to reduce the total content [Li + +Na + +K + ] is set to the above range.

[0132] In the optical glass of this embodiment, Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ Total content [Mg 2+ +Ca 2+ +Sr 2+ +Ba 2 + The lower limit of the total content is preferably 0%, and more preferably 1%, 3%, 5%, 7%, 9%, 10%, 11%, 12%, and 13%. In addition, the upper limit of the total content is preferably 30%, and more preferably 29%, 28%, 27%, 26%, 25%, 24%, 23%, 22%, 21%, 20%, 19%, 18%, 17%, and 16%. The total content may be 0%.

[0133] In addition, from the viewpoint of obtaining an optical glass with a higher refractive index and high dispersion, the total content [Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ The lower limit of the total content is preferably 3.5%, and more preferably 3.6%, 3.7%, 3.8%, 3.9%, 4.0%, 4.1%, 4.2%, 4.3%, 4.4%, and 4.5% in sequence. In addition, the upper limit of the total content is preferably 30%, and more preferably 29%, 28%, 27%, 26%, 25%, 24%, 23%, 22%, 21%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, and 8% in sequence.

[0134] If the total content [Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ If the total content is too low, the volatilization of the glass components increases, which may lead to a decrease in the thermal stability and devitrification resistance of the glass. On the other hand, if the total content is too high, there is a risk of impairing the high refractive index and the thermal stability of the glass. From the perspective of obtaining an optical glass having desired optical constants, reduced volatilization of glass components, and high thermal stability of the glass, it is preferable to set the total content within the above range.

[0135] In the optical glass of this embodiment, Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ and Zn 2+ Total content [Mg 2+ +Ca 2++Sr 2 + +Ba 2+ +Zn 2+ The upper limit of the total content is preferably 50%, and more preferably 45%, 40%, 35%, 30%, 25%, 24%, 23%, 22%, 21%, 20%, 19%, 18%, 17%, and 16%. The lower limit of the total content is preferably 0%, and more preferably 1%, 3%, 5%, 7%, 9%, 10%, 11%, 12%, and 13%. The total content may be 0%.

[0136] In addition, from the viewpoint of maintaining stability during reheating in optical glass with a higher refractive index and high dispersion, the total content [Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ The upper limit of the total content is preferably 30%, and more preferably 29%, 28%, 27%, 26%, 25%, 24%, 23%, 22%, 21%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, and 8%. The lower limit of the total content is preferably 3.5%, and more preferably 3.6%, 3.7%, 3.8%, 3.9%, 4.0%, 4.1%, 4.2%, 4.3%, 4.4%, and 4.5%.

[0137] If the total content [Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ If the total content is too high, there is a risk of impairing the high refractive index and the thermal stability of the glass. On the other hand, if the total content is too low, the volatilization of the glass components increases, and there is a risk of reducing the thermal stability and devitrification resistance of the glass. Therefore, it is preferable to set the total content within the above range.

[0138] In the optical glass of this embodiment, Li + 、Na + , K + Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ The total content [Li + +Na + +K + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+The lower limit of the total content is preferably 0%, and further preferably 1%, 3%, 5%, 7%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, and 20%. In addition, the upper limit of the total content is preferably 50%, and further more preferably 45%, 40%, 35%, 32%, 30%, 29%, 28%, 27%, 26%, 25%, 24%, and 23%. The total content may be 0%.

[0139] In addition, from the viewpoint of obtaining an optical glass with a higher refractive index and high dispersion, the total content [Li + +Na + +K + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ The lower limit of the total content is preferably 3.5%, and further preferably 3.6%, 3.7%, 3.8%, 3.9%, 4.0%, 4.1%, 4.2%, 4.3%, 4.4%, and 4.5%. In addition, the upper limit of the total content is preferably 50%, and further more preferably 45%, 40%, 35%, 32%, 30%, 29%, 28%, 27%, 26%, 25%, 24%, 23%, 22%, 21%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, and 6%.

[0140] From the viewpoint of obtaining an optical glass having desired optical constants, a glass transition temperature Tg, a lower liquidus temperature of the glass, and further reduced volatilization of the glass components during melting, it is preferred to reduce the total content [Li + +Na + +K + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ] is set to the above range.

[0141] In the optical glass of this embodiment, Li + 、Na + , K + , Rb + 、Cs + Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ The total content [Li + +Na + +K + +Rb ++Cs + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ The lower limit of the total content is preferably 0%. More preferably, the total content is greater than 0%. The lower limit of the total content is further preferably 1%, and further more preferably 3%, 5%, 7%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, and 20%. In addition, the upper limit of the total content is preferably 40%, and further more preferably 39%, 38%, 37%, 36%, 35%, 34%, 33%, 32%, 31%, 30%, 29%, 28%, 27%, 26%, 25%, 24%, and 23%. The total content may be 0%.

[0142] In addition, from the perspective of obtaining optical glass with higher refractive index and higher dispersion, Li + 、Na + , K + , Rb + 、Cs + Mg 2 + , Ca 2+ 、Sr 2+ And Ba 2+ The total content [Li + +Na + +K + +Rb + +Cs + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ The lower limit of the total content is preferably 3.5%, and further preferably 3.6%, 3.7%, 3.8%, 3.9%, 4.0%, 4.1%, 4.2%, 4.3%, 4.4%, and 4.5%. In addition, the upper limit of the total content is preferably 40%, and further more preferably 39%, 38%, 37%, 36%, 35%, 34%, 33%, 32%, 31%, 30%, 29%, 28%, 27%, 26%, 25%, 24%, 23%, 22%, 21%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, and 8%.

[0143] From the viewpoint of obtaining an optical glass having desired optical constants, a lower glass transition temperature Tg, reduced volatilization of glass components, and high thermal stability, it is preferred to reduce the total content [Li + +Na + +K ++Rb + +Cs + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ] is set to the above range.

[0144] In the optical glass of this embodiment, La 3+ 、Gd 3+ and Y 3+ The total content [La 3+ +Gd 3+ +Y 3+ The lower limit of the total content is preferably 0%. More preferably, the total content is greater than 0%. The lower limit of the total content is further preferably 5%, and further more preferably 10%, 15%, 20%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, and 38%. In addition, the upper limit of the total content is preferably 70%, and further more preferably 60%, 55%, 50%, 48%, 46%, 45%, 44%, 43%, 42%, and 41%.

[0145] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, La 3+ 、Gd 3+ and Y 3+ The total content [La 3+ +Gd 3+ +Y 3+ The lower limit of the total content is preferably 27%, and more preferably 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, and 44% in that order. In addition, the upper limit of the total content is preferably 60%, and more preferably 58%, 56%, 55%, 54%, 53%, 52%, 51%, 50%, 49%, and 48% in that order.

[0146] If the total content [La 3+ +Gd 3+ +Y 3+ ] is too little, there is a hidden danger that the desired optical constants cannot be obtained. If the total content is too much, there is a hidden danger that the thermal stability of the glass is reduced. From the viewpoint of obtaining an optical glass with a high refractive index nd, it is preferred that the total content be set to the above range.

[0147] In the optical glass of this embodiment, Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total content [Ti 4++Nb 5+ +W 6+ +Bi 3+ The lower limit of the total content is preferably 0%, and more preferably 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4%, and 1.6%. In addition, the upper limit of the total content is preferably 20%, and more preferably 15%, 10%, 5%, 4%, 3.5%, 3%, and 2.5%. The total content may be lower than 2.0%.

[0148] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total content [T i4+ +Nb 5+ +W 6+ +Bi 3+ ] is preferably greater than 0%, and its lower limit is preferably 0.1%, and further more preferably 0.1%, 0.5%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, and 2.0%. In addition, the upper limit of this total content is preferably 20%, and further more preferably 18%, 16%, 14%, 12%, 10%, 8%, 6%, 5%, 4%, 3.5%, 3.0%, and 2.5%.

[0149] From the perspective of maintaining high refractive index and low dispersion, the total content can be 0%. In addition, from the perspective of maintaining the desired Abbe number νd and improving the dispersion of the abnormal part in the visible light to near ultraviolet region, it is preferred to reduce the total content [Ti 4+ +Nb 5 + +W 6+ +Bi 3+ ] is set to the above range.

[0150] In the optical glass of this embodiment, Zr 4+ and Ta 5+ The total content [Zr 4+ +Ta 5+ The upper limit of the total content is preferably 20%, and further preferably 15%, 10%, 5%, 4%, 3%, 2%, and 1% in sequence. In addition, the lower limit of the total content is preferably 0%, and further more preferably 0.1%, 0.2%, and 0.3% in sequence.

[0151] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Zr 4+ and Ta 5+ The total content [Zr 4+ +Ta5+ The upper limit of the total content is preferably 20%, and further preferably 15%, 10%, 9%, 8%, 7%, 6%, 5%, and 4% in sequence. In addition, the lower limit of the total content is preferably 0%, and further more preferably 0.5%, 1.0%, 1.5%, 2.0%, and 2.5% in sequence.

[0152] From the perspective of maintaining high refractive index and low dispersion characteristics, the total content [Zr 4+ +Ta 5+ ] can be 0%. In addition, from the viewpoint of maintaining the thermal stability of the glass, it is preferred that the total content be set to the above range. If the total content is too much, there is a hidden danger of reduced thermal stability of the glass and a hidden danger of increased raw material costs.

[0153] In the optical glass of this embodiment, Ti 4+ 、Nb 5+ 、Bi 3+ 、W 6+ 、Zr 4+ and Ta 5+ The total content [Ti 4+ +Nb 5+ +Bi 3+ +W 6+ +Zr 4+ +Ta 5+ The upper limit of the total content is preferably 20%, and more preferably 15%, 10%, 5%, 4%, 3.5%, 3%, and 2.5% in sequence. In addition, the lower limit of the total content is preferably 0%, and more preferably 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4%, and 1.6% in sequence.

[0154] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Ti 4+ 、Nb 5+ 、Bi 3+ 、W 6+ 、Zr 4+ and Ta 5+ The total content [Ti 4+ +Nb 5+ +Bi 3+ +W 6+ +Zr 4+ +Ta 5+ The upper limit of the total content is preferably 20%, and more preferably 18%, 16%, 14%, 12%, 10%, 9%, 8%, 7%, and 6% in this order. In addition, the lower limit of the total content is preferably 0%, and more preferably 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, and 4.0% in this order.

[0155] From the perspective of maintaining high refractive index and low dispersion characteristics, the total content [Ti 4+ +Nb 5+ +Bi 3+ +W 6+ +Zr 4+ +Ta 5+ ] can be 0%. In addition, from the viewpoint of maintaining the desired Abbe number νd and improving the anomalous partial dispersion in the visible light to near-ultraviolet region, it is preferred that the total content be set to the above range.

[0156] In the optical glass of this embodiment, Si 4+ The content relative to Si 4+ and B 3+ The total content of cations is [Si 4+ / (Si 4+ +B 3+ The lower limit of the cation ratio is preferably 0.020, and more preferably 0.05, 0.070, 0.09, 0.13, 0.15, 0.17, 0.19, 0.21, 0.22, 0.23, 0.24, and 0.25, respectively. The upper limit of the cation ratio is preferably 0.80, and more preferably 0.70, 0.60, 0.50, 0.40, 0.35, 0.34, 0.33, and 0.32, respectively.

[0157] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Si 4+ The content relative to Si 4+ and B 3+ The total content of cations is [Si 4+ / (Si 4+ +B 3+ The lower limit of the cation ratio is preferably 0.070, and more preferably 0.08, 0.09, 0.10, 0.11, and 0.12 in this order. The upper limit of the cation ratio is preferably 0.80, and more preferably 0.70, 0.60, 0.50, 0.40, 0.35, 0.30, 0.29, 0.28, 0.27, 0.26, 0.25, 0.24, 0.23, 0.22, 0.21, and 0.20 in this order.

[0158] From the viewpoint of obtaining an optical glass having improved chemical durability, mechanical properties, and thermal stability, it is preferred that the cation ratio [Si 4+ / (Si 4+ +B 3+ )] is set to the above range.

[0159] In the optical glass of this embodiment, B 3+ The content relative to Si 4+ and B3+ The total content of cation ratio [B 3+ / (Si 4+ +B 3+ The upper limit of the cation ratio is preferably 0.980, and more preferably 0.95, 0.91, 0.87, 0.85, 0.83, 0.81, 0.79, 0.78, 0.77, 0.76, and 0.75, respectively. The lower limit of the cation ratio is preferably 0.20, and more preferably 0.30, 0.40, 0.50, 0.60, 0.65, 0.66, 0.67, and 0.68, respectively.

[0160] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, B 3+ The content relative to Si 4+ and B 3 + The total content of cation ratio [B 3+ / (Si 4+ +B 3+ The upper limit of the cation ratio is preferably 0.98, and more preferably 0.97, 0.96, 0.95, 0.94, 0.93, 0.92, 0.91, 0.90, 0.89, and 0.88. The lower limit of the cation ratio is preferably 0.20, and more preferably 0.30, 0.40, 0.50, 0.60, 0.65, 0.67, 0.69, 0.71, 0.73, 0.75, 0.77, 0.79, and 0.80.

[0161] From the viewpoint of obtaining an optical glass having improved chemical durability, mechanical properties and thermal stability, it is preferred to increase the cation ratio [B 3+ / (Si 4+ +B 3+ )] is set to the above range.

[0162] In the optical glass of this embodiment, Si 4+ 、B 3+ and P 5+ The total content [Si 4+ +B 3+ +P 5+ The lower limit of the total content is preferably 10%, and more preferably 15%, 20%, 22%, 24%, 26%, 28%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, and 37% in sequence. In addition, the upper limit of the total content is preferably 70%, and more preferably 65%, 60%, 58%, 56%, 54%, 52%, 50%, 48%, 47%, 46%, 45%, 44%, 43%, 42%, 41%, and 40% in sequence.

[0163] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Si 4+ 、B 3+ and P 5+ The total content [Si 4+ +B 3+ +P 5+ The lower limit of the total content is preferably 10%, and more preferably 15%, 20%, 22%, 24%, 26%, 28%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, and 43% in sequence. In addition, the upper limit of the total content is preferably 70%, and more preferably 65%, 60%, 58%, 56%, 54%, 52%, 50%, 48%, 47%, 46%, and 45% in sequence.

[0164] From the viewpoint of obtaining an optical glass having desired optical constants and abnormal partial dispersion, improved chemical durability, mechanical properties and thermal stability, and suppressed volatilization of glass components during melting, it is preferred to reduce the total content of [Si 4+ +B 3+ +P 5+ ] is set to the above range.

[0165] In the optical glass of this embodiment, Si 4+ The content relative to Si 4+ 、B 3+ and P 5+ The total content of cations is [Si 4+ / (Si 4+ +B 3+ +P 5+ The upper limit of the cation ratio is preferably 0.80, and more preferably 0.70, 0.60, 0.50, 0.40, 0.35, 0.34, 0.33, and 0.32, respectively. The lower limit of the cation ratio is preferably 0.020, and more preferably 0.05, 0.09, 0.13, 0.15, 0.17, 0.19, 0.21, 0.22, 0.23, 0.24, and 0.25, respectively.

[0166] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Si 4+ The content relative to Si 4+ 、B 3 + and P 5+ The total content of cations is [Si 4+ / (Si 4+ +B 3+ +P 5+The upper limit of the cation ratio is preferably 0.80, and more preferably 0.70, 0.60, 0.50, 0.40, 0.35, 0.30, 0.29, 0.28, 0.27, 0.26, 0.25, 0.24, 0.23, 0.22, 0.21, and 0.20. In addition, the lower limit of the cation ratio is preferably 0.070, and more preferably 0.08, 0.09, 0.10, 0.11, and 0.12.

[0167] From the viewpoint of obtaining an optical glass having improved chemical durability, mechanical properties and thermal stability, it is preferred to increase the cation ratio [Si 4+ / (Si 4+ +B 3+ +P 5+ )] is set to the above range.

[0168] In the optical glass of this embodiment, B 3+ The content relative to Si 4+ 、B 3+ and P 5+ The total content of cation ratio [B 3+ / (Si 4+ +B 3+ +P 5+ The upper limit of the cation ratio is preferably 0.980, and more preferably 0.95, 0.91, 0.87, 0.85, 0.83, 0.81, 0.79, 0.78, 0.77, 0.76, and 0.75, respectively. The lower limit of the cation ratio is preferably 0.20, and more preferably 0.30, 0.40, 0.50, 0.60, 0.65, 0.66, 0.67, and 0.68, respectively.

[0169] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, B 3+ The content relative to Si 4+ 、B 3+ and P 5+ The total content of cation ratio [B 3+ / (Si 4+ +B 3+ +P 5+ The upper limit of the cation ratio is preferably 0.98, and more preferably 0.97, 0.96, 0.95, 0.94, 0.93, 0.92, 0.91, 0.90, 0.89, and 0.88. The lower limit of the cation ratio is preferably 0.20, and more preferably 0.30, 0.40, 0.50, 0.60, 0.65, 0.67, 0.69, 0.71, 0.73, 0.75, 0.77, 0.79, and 0.80.

[0170] From the viewpoint of obtaining an optical glass having improved chemical durability, mechanical properties and thermal stability, it is preferred to increase the cation ratio [B 3+ / (Si 4+ +B 3+ +P 5+ )] is set to the above range.

[0171] In the optical glass of this embodiment, P 5+ The content relative to Si 4+ 、B 3+ and P 5+ The total content of cation ratio [P 5+ / (Si 4+ +B 3+ +P 5+ The upper limit of the cation ratio is preferably 0.50, and more preferably 0.40, 0.30, 0.20, 0.10, 0.08, 0.06, 0.04, and 0.02. In addition, the lower limit of the cation ratio is preferably 0, and more preferably 0.005, 0.01, and 0.015. The cation ratio may be 0.

[0172] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, P 5+ The content relative to Si 4+ 、B 3+ and P 5+ The total content of cation ratio [P 5+ / (Si 4+ +B 3+ +P 5+ The upper limit of the cation ratio is preferably 0.50, and more preferably 0.40, 0.30, 0.20, 0.10, 0.08, 0.06, 0.04, and 0.02. In addition, the lower limit of the cation ratio is preferably 0, and more preferably 0.005, 0.01, and 0.015. The cation ratio may be 0.

[0173] From the viewpoint of obtaining an optical glass having improved chemical durability, mechanical properties and thermal stability, it is preferred to increase the cation ratio [P 5+ / (Si 4+ +B 3+ +P 5+ )] is set to the above range.

[0174] In the optical glass of this embodiment, Li + The content relative to Li + 、Na + and K + The total cation content ratio [Li + / (Li + +Na+ +K + The upper limit of the cation ratio is preferably 1, and more preferably 0.95, 0.90, or 0.85. In addition, the lower limit of the cation ratio is preferably 0, and more preferably 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, or 0.7. The cation ratio may be 1.

[0175] In addition, from the perspective of obtaining optical glass with higher refractive index and higher dispersion, Li + The content relative to Li + 、Na + and K + The total cation content ratio [Li + / (Li + +Na + +K + The upper limit of the cation ratio is preferably 1, and more preferably 0.95, 0.90, or 0.85. In addition, the lower limit of the cation ratio is preferably 0, and more preferably 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, or 0.7. The cation ratio may be 1.

[0176] From the viewpoint of suppressing the decrease in stability during reheating and lowering the glass transition temperature Tg, it is preferred to increase the cation ratio [Li + / (Li + +Na + +K + )] is set to the above range.

[0177] In the optical glass of this embodiment, Na + The content relative to Li + 、Na + and K + The total cation content of [Na + / (Li + +Na + +K + The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, or 0.3. In addition, the lower limit of the cation ratio is preferably 0, and more preferably 0.05, 0.10, or 0.15. The cation ratio may be 0.

[0178] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Na + The content relative to Li + 、Na + and K + The total cation content of [Na + / (Li + +Na+ +K + The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, or 0.3. In addition, the lower limit of the cation ratio is preferably 0, and more preferably 0.05, 0.10, or 0.15. The cation ratio may be 0.

[0179] From the viewpoint of suppressing the decrease in stability during reheating and lowering the glass transition temperature Tg, it is preferred to increase the cation ratio [Na + / (Li + +Na + +K + )] is set to the above range.

[0180] In the optical glass of this embodiment, K + The content relative to Li + 、Na + and K + The total content of cation ratio [K + / (Li + +Na + +K + The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, or 0.3. In addition, the lower limit of the cation ratio is preferably 0, and more preferably 0.05, 0.10, or 0.15. The cation ratio may be 0.

[0181] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, K + The content relative to Li + 、Na + and K + The total content of cation ratio [K + / (Li + +Na + +K + The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, or 0.3. In addition, the lower limit of the cation ratio is preferably 0, and more preferably 0.05, 0.10, or 0.15. The cation ratio may be 0.

[0182] From the viewpoint of suppressing the decrease in stability during reheating and lowering the glass transition temperature Tg, it is preferred to increase the cation ratio [K + / (Li + +Na + +K + )] is set to the above range.

[0183] In the optical glass of this embodiment, Mg 2+ The content relative to Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ The total cation content ratio [Mg 2+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.55, 0.5, 0.45, or 0.4. The lower limit of the cation ratio is preferably 0, and more preferably 0.1, 0.15, 0.18, 0.2, 0.22, 0.24, 0.26, 0.28, or 0.3. The cation ratio may be 0.

[0184] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Mg 2+ The content relative to Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ The total cation content ratio [Mg 2+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.55, 0.5, 0.45, or 0.4. The lower limit of the cation ratio is preferably 0, and more preferably 0.1, 0.15, 0.18, 0.2, 0.22, 0.24, 0.26, 0.28, or 0.3. The cation ratio may be 0.

[0185] From the viewpoint of the stability and thermal stability of the glass during reheating, it is preferred to increase the cation ratio [Mg 2+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ )] is set to the above range.

[0186] In the optical glass of this embodiment, Ca 2+ The content relative to Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ The total cation content ratio [Ca 2+ / (Mg 2+ +Ca 2+ +Sr2+ +Ba 2+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, or 0.15. The lower limit of the cation ratio is preferably 0, and more preferably 0.05 or 0.1. The cation ratio may be 0.

[0187] In addition, from the viewpoint of obtaining an optical glass with a higher refractive index and high dispersion, Ca 2+ The content relative to Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ The total cation content ratio [Ca 2+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, or 0.15. The lower limit of the cation ratio is preferably 0, and more preferably 0.05 or 0.1. The cation ratio may be 0.

[0188] From the viewpoint of suppressing the decrease in stability and thermal stability of the glass during reheating, it is preferred to increase the cation ratio [Ca 2+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ )] is set to the above range.

[0189] In the optical glass of this embodiment, Sr 2+ The content relative to Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ The total content of cation ratio [Sr 2+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, or 0.15. The lower limit of the cation ratio is preferably 0, and more preferably 0.05 or 0.1. The cation ratio may be 0.

[0190] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Sr 2+ The content relative to Mg 2+ , Ca2+ 、Sr 2+ And Ba 2+ The total content of cation ratio [Sr 2+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, or 0.15. The lower limit of the cation ratio is preferably 0, and more preferably 0.05 or 0.1. The cation ratio may be 0.

[0191] From the viewpoint of suppressing the decrease in stability and thermal stability of the glass during reheating, it is preferred to increase the cation ratio [Sr 2+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ )] is set to the above range.

[0192] In the optical glass of this embodiment, Ba 2+ The content relative to Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ The total content of cation ratio [Ba 2+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ The lower limit of the cation ratio is preferably 0, and more preferably 0.1, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, and 0.60. The upper limit of the cation ratio is preferably 1, and more preferably 0.90, 0.80, 0.75, 0.74, 0.73, 0.72, 0.71, and 0.70.

[0193] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Ba 2+ The content relative to Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ The total content of cation ratio [Ba 2+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+The lower limit of the cation ratio is preferably 0, and more preferably 0.1, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, and 0.60. The upper limit of the cation ratio is preferably 1, and more preferably 0.90, 0.80, 0.75, 0.74, 0.73, 0.72, 0.71, and 0.70.

[0194] From the viewpoint of suppressing the decrease in stability and thermal stability of the glass during reheating, the cation ratio [Ba 2+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ )] is preferably within the above range.

[0195] In the optical glass of this embodiment, Mg 2+ The content relative to Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ and Zn 2+ The total cation content ratio [Mg 2+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.55, 0.5, 0.45, or 0.4. The lower limit of the cation ratio is preferably 0, and more preferably 0.1, 0.15, 0.18, 0.2, 0.22, 0.24, 0.26, 0.28, or 0.3. The cation ratio may be 0.

[0196] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Mg 2+ The content relative to Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ and Zn 2+ The total cation content ratio [Mg 2+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.55, 0.5, 0.45, or 0.4. The lower limit of the cation ratio is preferably 0, and more preferably 0.1, 0.15, 0.18, 0.2, 0.22, 0.24, 0.26, 0.28, or 0.3. The cation ratio may be 0.

[0197] From the viewpoint of suppressing the decrease in stability and thermal stability of the glass during reheating, it is preferred to increase the cation ratio [Mg 2+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ )] is set to the above range.

[0198] In the optical glass of this embodiment, Ca 2+ The content relative to Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ and Zn 2+ The total cation content ratio [Ca 2+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, or 0.15. The lower limit of the cation ratio is preferably 0, and more preferably 0.05 or 0.1. The cation ratio may be 0.

[0199] In addition, from the viewpoint of obtaining an optical glass with a higher refractive index and high dispersion, Ca 2+ The content relative to Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ and Zn 2+ The total cation content ratio [Ca 2+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, or 0.15. The lower limit of the cation ratio is preferably 0, and more preferably 0.05 or 0.1. The cation ratio may be 0.

[0200] From the viewpoint of suppressing the decrease in stability and thermal stability of the glass during reheating, it is preferred to increase the cation ratio [Ca 2+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ )] is set to the above range.

[0201] In the optical glass of this embodiment, Sr 2+ The content relative to Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ and Zn 2+ The total content of cation ratio [Sr 2+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, or 0.15. The lower limit of the cation ratio is preferably 0, and more preferably 0.05 or 0.1. The cation ratio may be 0.

[0202] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Sr 2+ The content relative to Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ and Zn 2+ The total content of cation ratio [Sr 2+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, or 0.15. The lower limit of the cation ratio is preferably 0, and more preferably 0.05 or 0.1. The cation ratio may be 0.

[0203] From the viewpoint of suppressing the decrease in stability and thermal stability of the glass during reheating, it is preferred to increase the cation ratio [Sr 2+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba2+ +Zn 2+ )] is set to the above range.

[0204] In the optical glass of this embodiment, Ba 2+ The content relative to Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ and Zn 2+ The total content of cation ratio [Ba 2+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ The lower limit of the cation ratio is preferably 0, and more preferably 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, and 0.60. The upper limit of the cation ratio is preferably 1, and more preferably 0.90, 0.80, 0.75, 0.74, 0.73, 0.72, 0.71, and 0.70. The cation ratio may be 0.

[0205] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Ba 2+ The content relative to Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ and Zn 2+ The total content of cation ratio [Ba 2+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ The lower limit of the cation ratio is preferably 0, and more preferably 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, and 0.60. The upper limit of the cation ratio is preferably 1, and more preferably 0.90, 0.80, 0.75, 0.74, 0.73, 0.72, 0.71, and 0.70. The cation ratio may be 0.

[0206] From the viewpoint of suppressing the decrease in stability and thermal stability of the glass during reheating, it is preferred to increase the cation ratio [Ba 2+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ )] is set to the above range.

[0207] In the optical glass of this embodiment, Zn 2+ The content relative to Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ and Zn 2+ The total content of cation ratio [Zn 2+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, or 0.15. The lower limit of the cation ratio is preferably 0, and more preferably 0.05 or 0.1. The cation ratio may be 0.

[0208] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Zn 2+ Mg content 2+ , Ca 2+ 、Sr 2 + 、Ba 2+ and Zn 2+ The total content of cation ratio [Zn 2+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, or 0.15. The lower limit of the cation ratio is preferably 0, and more preferably 0.05 or 0.1. The cation ratio may be 0.

[0209] From the viewpoint of suppressing the decrease in stability and thermal stability of the glass during reheating and maintaining the high refractive index of the glass, it is preferred to increase the cation ratio [Zn 2+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +Zn 2+ )] is set to the above range.

[0210] In the optical glass of this embodiment, La 3+ The content relative to La 3+ 、Gd 3+ and Y 3+The total content of cation ratio [La 3+ / (La 3+ +Gd 3+ +Y 3+ The lower limit of the cation ratio is preferably 0, and more preferably 0.05, 0.10, 0.15, 0.20, 0.25, 0.27, 0.29, 0.31, 0.33, 0.35, 0.37, 0.39, 0.40, 0.41, 0.42, 0.43, 0.44, and 0.45. The upper limit of the cation ratio is preferably 1, and more preferably 0.95, 0.90, 0.85, 0.80, 0.75, 0.70, 0.65, 0.60, 0.59, 0.58, 0.57, 0.56, 0.55, 0.54, and 0.53.

[0211] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, La 3+ The content relative to La 3+ 、Gd 3+ and Y 3+ The total content of cation ratio [La 3+ / (La 3+ +Gd 3+ +Y 3+ The lower limit of the cation ratio is preferably 0, and more preferably 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.62, 0.64, 0.66, and 0.68. The upper limit of the cation ratio is preferably 1, and more preferably 0.95, 0.90, 0.85, 0.80, 0.78, 0.76, 0.74, and 0.72.

[0212] From the viewpoint of increasing the refractive index nd and suppressing the decrease in the thermal stability of the glass, it is preferred to increase the cation ratio [La 3+ / (La 3+ +Gd 3+ +Y 3+ )] is set to the above range.

[0213] In the optical glass of this embodiment, Gd 3+ The content relative to La 3+ 、Gd 3+ and Y 3+ The total content of cation ratio [Gd 3+ / (La 3+ +Gd 3+ +Y 3+The upper limit of the cation ratio is preferably 1, and more preferably 0.95, 0.90, 0.85, 0.80, 0.75, 0.70, 0.65, 0.60, 0.55, 0.50, 0.45, 0.40, 0.35, 0.30, 0.25, 0.20, 0.15, 0.10. The lower limit of the cation ratio is preferably 0, and more preferably 0.01, 0.05. The cation ratio may be 0.

[0214] From the viewpoint of increasing the refractive index nd and suppressing the decrease in thermal stability of glass, reducing the amount of Gd as a heavy rare earth 3+ From the perspective of the content of Gd 3+ / (La 3+ +Gd 3+ +Y 3+ )] is set to the above range.

[0215] In addition, Gd 3+ The content relative to La 3+ 、Gd 3+ and Y 3+ The total content of cation ratio [Gd 3+ / (La 3+ +Gd 3+ +Y 3+ The upper limit of the cation ratio is preferably 1, and more preferably 0.95, 0.90, 0.85, 0.80, 0.75, 0.70, 0.65, 0.60, 0.55, 0.50, 0.48, 0.46, 0.44, 0.42, 0.40, 0.38, 0.36, 0.34, 0.32. The lower limit of the cation ratio is preferably 0, and more preferably 0.01, 0.05, 0.10, 0.15, 0.20, 0.22, 0.24, 0.26, 0.28. The cation ratio may be 0.

[0216] In the optical glass of this embodiment, Y 3+ The content relative to La 3+ 、Gd 3+ and Y 3+ The total content of cation ratio [Y 3+ / (La 3+ +Gd 3+ +Y 3+The upper limit of the cation ratio is preferably 1, and more preferably 0.95, 0.90, 0.85, 0.80, 0.75, 0.70, 0.65, 0.63, 0.61, 0.60, 0.59, 0.58, 0.57, 0.56, and 0.55. The lower limit of the cation ratio is preferably 0, and more preferably 0.05, 0.10, 0.15, 0.20, 0.25, 0.27, 0.29, 0.31, 0.33, 0.35, 0.37, 0.39, 0.40, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, and 0.48. The cation ratio may be 0.

[0217] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Y 3+ The content relative to La 3+ 、Gd 3 + and Y 3+ The total content of cation ratio [Y 3+ / (La 3+ +Gd 3+ +Y 3+ The upper limit of the cation ratio is preferably 1, and more preferably 0.95, 0.90, 0.85, 0.80, 0.75, 0.70, 0.65, 0.60, 0.55, 0.50, 0.45, 0.40, 0.35, 0.30, 0.25, 0.20, 0.15, 0.10, 0.05. The lower limit of the cation ratio is preferably 0, and more preferably 0.01, 0.02, 0.03. The cation ratio may be 0.

[0218] From the viewpoint of increasing the refractive index nd and suppressing the decrease in the thermal stability of the glass, it is preferred to increase the cation ratio [Y 3 + / (La 3+ +Gd 3+ +Y 3+ )] is set to the above range.

[0219] In the optical glass of this embodiment, Ti 4+ The content relative to Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total content of cation ratio [Ti 4+ / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.45, 0.4, 0.35, 0.3, 0.25, 0.23, 0.21, 0.2, 0.19, 0.18, 0.17, 0.16, 0.15, 0.14, 0.13, 0.12, and 0.11. The lower limit of the cation ratio is preferably 0, and more preferably 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, and 0.08. The cation ratio may be 0.

[0220] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Ti 4+ The content relative to Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total content of cation ratio [Ti 4+ / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.45, 0.4, 0.35, 0.3, 0.25, 0.23, 0.21, 0.2, 0.19, 0.18, 0.17, 0.16, 0.15, 0.14, 0.13, 0.12, and 0.11. The lower limit of the cation ratio is preferably 0, and more preferably 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, and 0.08. The cation ratio may be 0.

[0221] From the viewpoint of increasing the refractive index nd and maintaining the desired Abbe number νd and the thermal stability of the glass, it is preferred to increase the cation ratio [Ti 4+ / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ )] is set to the above range.

[0222] In the optical glass of this embodiment, Nb 5+ The content relative to Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total content of cation ratio [Nb 5+ / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+The upper limit of the cation ratio is preferably 1, and more preferably 0.95, 0.90, 0.85, 0.80, 0.75, 0.74, 0.73, 0.72, 0.71, 0.70, 0.69, 0.68, and 0.67. The lower limit of the cation ratio is preferably 0, and more preferably 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.60, 0.61, and 0.62. The cation ratio may be 0.

[0223] In addition, from the viewpoint of obtaining an optical glass with a higher refractive index and high dispersion, Nb 5+ The content relative to Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total content of cation ratio [Nb 5+ / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ The upper limit of the cation ratio is preferably 1, and more preferably 0.95, 0.90, 0.85, 0.80, 0.75, 0.74, 0.73, 0.72, 0.71, 0.70, 0.69, 0.68, and 0.67. The lower limit of the cation ratio is preferably 0, and more preferably 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.60, 0.61, and 0.62. The cation ratio may be 0.

[0224] From the viewpoint of increasing the refractive index nd, maintaining the desired Abbe number νd, and maintaining the thermal stability of the glass, it is preferred to increase the cation ratio [Nb 5+ / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ )] is set to the above range.

[0225] In the optical glass of this embodiment, W 6+ The content relative to Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total content of cation ratio [W 6+ / (Ti 4+ +Nb 5+ +W6+ +Bi 3+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.45, 0.44, 0.43, 0.42, 0.41, 0.40, 0.39, 0.38, 0.37, 0.36, 0.35, 0.34, 0.33, 0.32, 0.31, 0.3, 0.29, 0.28, 0.27. The lower limit of the cation ratio is preferably 0, and more preferably 0.05, 0.1, 0.12, 0.14, 0.16, 0.18, 0.20, 0.21, 0.22, 0.23, 0.24. The cation ratio may be 0.

[0226] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, W 6+ The content relative to Ti 4+ 、Nb 5 + 、W 6+ and Bi 3+ The total content of cation ratio [W 6+ / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.45, 0.44, 0.43, 0.42, 0.41, 0.40, 0.39, 0.38, 0.37, 0.36, 0.35, 0.34, 0.33, 0.32, 0.31, 0.3, 0.29, 0.28, 0.27. The lower limit of the cation ratio is preferably 0, and more preferably 0.05, 0.1, 0.12, 0.14, 0.16, 0.18, 0.20, 0.21, 0.22, 0.23, 0.24. The cation ratio may be 0.

[0227] From the viewpoint of increasing the relative partial dispersion Pg,F, maintaining the desired Abbe number νd, and maintaining the thermal stability of the glass, it is preferred to reduce the cation ratio [W 6+ / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ )] is set to the above range.

[0228] In the optical glass of this embodiment, Bi 3+ The content relative to Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total content of cation ratio [Bi3+ / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.45, 0.44, 0.43, 0.42, 0.41, 0.40, 0.39, 0.38, 0.37, 0.36, 0.35, 0.34, 0.33, 0.32, 0.31, 0.3, 0.29, 0.28, or 0.27. The lower limit of the cation ratio is preferably 0, and may be 0.05, 0.1, 0.12, 0.14, 0.16, 0.18, 0.20, 0.21, 0.22, 0.23, or 0.24. The cation ratio may be 0.

[0229] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Bi 3+ The content relative to Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total content of cation ratio [Bi 3+ / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.45, 0.44, 0.43, 0.42, 0.41, 0.40, 0.39, 0.38, 0.37, 0.36, 0.35, 0.34, 0.33, 0.32, 0.31, 0.3, 0.29, 0.28, or 0.27. The lower limit of the cation ratio is preferably 0, and may be 0.05, 0.1, 0.12, 0.14, 0.16, 0.18, 0.20, 0.21, 0.22, 0.23, or 0.24. The cation ratio may be 0.

[0230] From the viewpoint of increasing the refractive index nd and the relative partial dispersion Pg,F, maintaining the desired Abbe number νd and maintaining the thermal stability of the glass, and reducing damage to platinum melting equipment, it is preferred to increase the cation ratio [Bi 3+ / (Ti 4+ +Nb 5+ +W 6+ +Bi 3+ )] is set to the above range.

[0231] In the optical glass of this embodiment, Zr 4+ The content of Zr 4+ and Ta 5+The total content of cation ratio [Zr 4+ / (Zr 4+ +Ta 5+ The upper limit of the cation ratio is preferably 1, and more preferably 0.95, 0.90, or 0.85. The lower limit of the cation ratio is preferably 0, and more preferably 0.5, 0.6, 0.7, or 0.8. The cation ratio may be 0.

[0232] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Zr 4+ The content of Zr 4+ and Ta 5+ The total content of cation ratio [Zr 4+ / (Zr 4+ +Ta 5+ The upper limit of the cation ratio is preferably 1, and more preferably 0.95, 0.90, or 0.85. The lower limit of the cation ratio is preferably 0, and more preferably 0.5, 0.6, 0.7, or 0.8. The cation ratio may be 0.

[0233] From the viewpoint of maintaining the desired optical constants and suppressing the cost of raw materials, it is preferred to increase the cation ratio [Zr 4+ / (Zr 4+ +Ta 5+ )] is set to the above range.

[0234] In the optical glass of this embodiment, Ta 5+ The content of Zr 4+ and Ta 5+ The total content of cation ratio [Ta 5+ / (Zr 4+ +Ta 5+ The upper limit of the cation ratio is preferably 1, and more preferably 0.5, 0.4, 0.3, or 0.2. The lower limit of the cation ratio is preferably 0, and may be 0.05, 0.10, or 0.15. The cation ratio may be 0.

[0235] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Ta 5+ The content of Zr 4+ and Ta 5+ The total content of cation ratio [Ta 5+ / (Zr 4+ +Ta 5+ The upper limit of the cation ratio is preferably 1, and more preferably 0.5, 0.4, 0.3, or 0.2. The lower limit of the cation ratio is preferably 0, and may be 0.05, 0.10, or 0.15. The cation ratio may be 0.

[0236] From the viewpoint of maintaining the desired optical constants and suppressing the cost of raw materials, it is preferred to increase the cation ratio [Ta 5+ / (Zr 4+ +Ta 5+ )] is set to the above range.

[0237] In the optical glass of this embodiment, Ti 4+ The content relative to Ti 4+ 、Nb 5+ 、Bi 3+ 、W 6+ 、Zr 4+ and Ta 5+ The total content of cation ratio [Ti 4+ / (Ti 4+ +Nb 5+ +Bi 3+ +W 6+ +Zr 4+ +Ta 5+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.45, 0.4, 0.35, 0.3, 0.25, 0.23, 0.21, 0.2, 0.19, 0.18, 0.17, 0.16, 0.15, 0.14, 0.13, 0.12, 0.11, 0.10, 0.09, 0.08, 0.07, 0.06. The lower limit of the cation ratio is preferably 0, and more preferably 0.01, 0.02, 0.03, 0.04. The cation ratio may be 0.

[0238] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Ti 4+ The content relative to Ti 4+ 、Nb 5+ 、Bi 3+ 、W 6+ 、Zr 4+ and Ta 5+ The total content of cation ratio [Ti 4+ / (Ti 4+ +Nb 5+ +Bi 3+ +W 6+ +Zr 4+ +Ta 5+The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.45, 0.4, 0.35, 0.3, 0.25, 0.23, 0.21, 0.2, 0.19, 0.18, 0.17, 0.16, 0.15, 0.14, 0.13, 0.12, 0.11, 0.10, 0.09, 0.08, 0.07, 0.06. The lower limit of the cation ratio is preferably 0, and more preferably 0.01, 0.02, 0.03, 0.04. The cation ratio may be 0.

[0239] From the viewpoint of increasing the refractive index nd and maintaining the desired Abbe number νd, it is preferred to increase the cation ratio [Ti 4+ / (Ti 4+ +Nb 5+ +Bi 3+ +W 6+ +Zr 4+ +Ta 5+ )] is set to the above range.

[0240] In the optical glass of this embodiment, Nb 5+ The content relative to Ti 4+ 、Nb 5+ 、Bi 3+ 、W 6+ 、Zr 4+ and Ta 5+ The total content of cation ratio [Nb 5+ / (Ti 4+ +Nb 5+ +Bi 3+ +W 6+ +Zr 4+ +Ta 5+ The upper limit of the cation ratio is preferably 1, and more preferably 0.95, 0.90, 0.85, 0.80, 0.75, 0.70, 0.65, 0.60, 0.55, 0.50, 0.45, 0.40, 0.35, 0.34, 0.33, 0.32, 0.31, 0.30, 0.29, 0.28, and 0.27. The lower limit of the cation ratio is preferably 0, and more preferably 0.05, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, and 0.24. The cation ratio may be 0.

[0241] In addition, from the viewpoint of obtaining an optical glass with a higher refractive index and high dispersion, Nb 5+ The content relative to Ti 4+ 、Nb 5+ 、Bi3+ 、W 6+ 、Zr 4+ and Ta 5+ The total content of cation ratio [Nb 5+ / (Ti 4+ +Nb 5+ +Bi 3+ +W 6+ +Zr 4+ +Ta 5+ The upper limit of the cation ratio is preferably 1, and more preferably 0.95, 0.90, 0.85, 0.80, 0.75, 0.70, 0.65, 0.60, 0.55, 0.50, 0.45, 0.40, 0.35, 0.34, 0.33, 0.32, 0.31, 0.30, 0.29, 0.28, and 0.27. The lower limit of the cation ratio is preferably 0, and more preferably 0.05, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, and 0.24. The cation ratio may be 0.

[0242] From the viewpoint of increasing the refractive index nd and maintaining the desired Abbe number νd, it is preferred to increase the cation ratio [Nb 5+ / (Ti 4+ +Nb 5+ +Bi 3+ +W 6+ +Zr 4+ +Ta 5+ )] is set to the above range.

[0243] In the optical glass of this embodiment, Bi 3+ The content relative to Ti 4+ 、Nb 5+ 、Bi 3+ 、W 6+ 、Zr 4+ and Ta 5+ The total content of cation ratio [Bi 3+ / (Ti 4+ +Nb 5+ +Bi 3+ +W 6+ +Zr 4+ +Ta 5+The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.35, 0.30, 0.29, 0.28, 0.27, 0.26, 0.25, 0.24, 0.23, 0.22, 0.21, 0.20, 0.19, 0.18, 0.17, 0.16, 0.15, 0.14, 0.13, 0.12, or 0.11. The lower limit of the cation ratio is preferably 0, and may be 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, or 0.09. The cation ratio may be 0.

[0244] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Bi 3+ The content relative to Ti 4+ 、Nb 5+ 、Bi 3+ 、W 6+ 、Zr 4+ and Ta 5+ The total content of cation ratio [Bi 3+ / (Ti 4+ +Nb 5+ +Bi 3+ +W 6+ +Zr 4+ +Ta 5+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.35, 0.30, 0.29, 0.28, 0.27, 0.26, 0.25, 0.24, 0.23, 0.22, 0.21, 0.20, 0.19, 0.18, 0.17, 0.16, 0.15, 0.14, 0.13, 0.12, or 0.11. The lower limit of the cation ratio is preferably 0, and may be 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, or 0.09. The cation ratio may be 0.

[0245] From the viewpoint of increasing the refractive index nd and the relative partial dispersion Pg,F, maintaining the desired Abbe number νd and maintaining the thermal stability of the glass, and reducing damage to platinum melting equipment, it is preferred to increase the cation ratio [Bi 3+ / (Ti 4+ +Nb 5+ +Bi 3+ +W 6+ +Zr 4+ +Ta 5+ )] is set to the above range.

[0246] In the optical glass of this embodiment, W 6+The content relative to Ti 4+ 、Nb 5+ 、Bi 3+ 、W 6+ 、Zr 4+ and Ta 5+ The total content of cation ratio [W 6+ / (Ti 4+ +Nb 5+ +Bi 3+ +W 6+ +Zr 4+ +Ta 5+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.35, 0.30, 0.29, 0.28, 0.27, 0.26, 0.25, 0.24, 0.23, 0.22, 0.21, 0.20, 0.19, 0.18, 0.17, 0.16, 0.15, 0.14, 0.13, 0.12, and 0.11. The lower limit of the cation ratio is preferably 0, and more preferably 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, and 0.09. The cation ratio may be 0.

[0247] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, W 6+ The content relative to Ti 4+ 、Nb 5 + 、Bi 3+ 、W 6+ 、Zr 4+ and Ta 5+ The total content of cation ratio [W 6+ / (Ti 4+ +Nb 5+ +Bi 3+ +W 6+ +Zr 4+ +Ta 5+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.35, 0.30, 0.29, 0.28, 0.27, 0.26, 0.25, 0.24, 0.23, 0.22, 0.21, 0.20, 0.19, 0.18, 0.17, 0.16, 0.15, 0.14, 0.13, 0.12, and 0.11. The lower limit of the cation ratio is preferably 0, and more preferably 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, and 0.09. The cation ratio may be 0.

[0248] From the viewpoint of increasing the relative partial dispersion Pg,F, maintaining the desired Abbe number νd, and maintaining the thermal stability of the glass, it is preferred to reduce the cation ratio [W 6+ / (Ti 4+ +Nb 5+ +Bi 3+ +W 6+ +Zr 4+ +Ta 5+ )] is set to the above range.

[0249] In the optical glass of this embodiment, Zr 4+ The content relative to Ti 4+ 、Nb 5+ 、Bi 3+ 、W 6+ 、Zr 4+ and Ta 5+ The total content of cation ratio [Zr 4+ / (Ti 4+ +Nb 5+ +Bi 3+ +W 6+ +Zr 4+ +Ta 5+ The upper limit of the cation ratio is preferably 1, and more preferably 0.95, 0.9, 0.85, 0.80, 0.75, 0.70, 0.69, 0.68, 0.67, 0.66, 0.65, 0.64, 0.63, and 0.62. The lower limit of the cation ratio is preferably 0, and more preferably 0.01, 0.1, 0.2, 0.3, 0.4, 0.45, 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, and 0.58. The cation ratio may be 0.

[0250] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Zr 4+ The content relative to Ti 4+ 、Nb 5+ 、Bi 3+ 、W 6+ 、Zr 4+ and Ta 5+ The total content of cation ratio [Zr 4+ / (Ti 4+ +Nb 5+ +Bi 3+ +W 6+ +Zr 4+ +Ta 5+The upper limit of the cation ratio is preferably 1, and more preferably 0.95, 0.9, 0.85, 0.80, 0.75, 0.70, 0.69, 0.68, 0.67, 0.66, 0.65, 0.64, 0.63, and 0.62. The lower limit of the cation ratio is preferably 0, and more preferably 0.01, 0.1, 0.2, 0.3, 0.4, 0.45, 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, and 0.58. The cation ratio may be 0.

[0251] From the viewpoint of increasing the refractive index nd while maintaining the desired Abbe number νd, and from the viewpoint of improving the mechanical properties and chemical durability of the glass, it is preferred to increase the cation ratio [Zr 4+ / (Ti 4+ +Nb 5+ +Bi 3+ +W 6+ +Zr 4+ +Ta 5+ )] is set to the above range.

[0252] In the optical glass of this embodiment, Ta 5+ The content relative to Ti 4+ 、Nb 5+ 、Bi 3+ 、W 6+ 、Zr 4+ and Ta 5+ The total content of cation ratio [Ta 5+ / (Ti 4+ +Nb 5+ +Bi 3+ +W 6+ +Zr 4+ +Ta 5+ The upper limit of the cation ratio is preferably 1, and more preferably 0.5, 0.4, 0.3, 0.25, 0.2, 0.15, 0.1, 0.08, 0.06, or 0.04. The lower limit of the cation ratio is preferably 0, and may be 0.01, 0.02, or 0.03. The cation ratio may be 0.

[0253] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Ta 5+ The content relative to Ti 4+ 、Nb 5+ 、Bi 3+ 、W 6+ 、Zr 4+ and Ta 5+ The total content of cation ratio [Ta 5+ / (Ti 4+ +Nb 5+ +Bi3+ +W 6+ +Zr 4+ +Ta 5+ The upper limit of the cation ratio is preferably 1, and more preferably 0.5, 0.4, 0.3, 0.25, 0.2, 0.15, 0.1, 0.08, 0.06, or 0.04. The lower limit of the cation ratio is preferably 0, and may be 0.01, 0.02, or 0.03. The cation ratio may be 0.

[0254] From the viewpoint of maintaining the desired constant and suppressing the cost of raw materials, it is preferred to reduce the cation ratio [Ta 5+ / (Ti 4+ +Nb 5+ +Bi 3+ +W 6+ +Zr 4+ +Ta 5+ )] is set to the above range.

[0255] In the optical glass of this embodiment, Al 3+ The content relative to Si 4+ and B 3+ The total content of cations [Al 3+ / (Si 4+ +B 3+ The upper limit of the cation ratio is preferably 0.5, and more preferably 0.45, 0.40, 0.35, 0.30, 0.25, and 0.20. The lower limit of the cation ratio is preferably 0, and more preferably 0.01, 0.05, 0.1, and 0.15. The cation ratio may be 0.

[0256] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Al 3+ The content relative to Si 4+ and B 3+ The total content of cations [Al 3+ / (Si 4+ +B 3+ The upper limit of the cation ratio is preferably 0.5, and more preferably 0.45, 0.40, 0.35, 0.30, 0.25, and 0.20. The lower limit of the cation ratio is preferably 0, and more preferably 0.01, 0.05, 0.1, and 0.15. The cation ratio may be 0.

[0257] By increasing the cation ratio [Al 3+ / (Si 4+ +B 3+)] to improve the mechanical properties and chemical durability of the glass. On the other hand, if the cation ratio is too high, the liquidus temperature rises and the thermal stability of the glass is impaired. From the perspective of maintaining the thermal stability of the glass, it is preferred that the cation ratio be within the above range.

[0258] In the optical glass of this embodiment, Al 3+ The content relative to Li + 、Na + and K + The total content of cations [Al 3+ / (Li + +Na + +K + The upper limit of the cation ratio is preferably 2, and more preferably 1.8, 1.6, 1.4, 1.2, 1.0, 0.8, 0.6, 0.4, and 0.2. The lower limit of the cation ratio is preferably 0, and more preferably 0.05, 0.1, and 0.15. The cation ratio can be 0.

[0259] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Al 3+ The content relative to Li + 、Na + and K + The total content of cations [Al 3+ / (Li + +Na + +K + The upper limit of the cation ratio is preferably 2, and more preferably 1.8, 1.6, 1.4, 1.2, 1.0, 0.8, 0.6, 0.4, and 0.2. The lower limit of the cation ratio is preferably 0, and more preferably 0.05, 0.1, and 0.15. The cation ratio can be 0.

[0260] By increasing the cation ratio [Al 3+ / (Li + +Na + +K + )] to improve the mechanical properties and chemical durability of the glass. On the other hand, if the cation ratio is too high, the liquidus temperature rises and the thermal stability of the glass is impaired. From the perspective of maintaining the thermal stability of the glass, it is preferred that the cation ratio be within the above range.

[0261] In the optical glass of this embodiment, Al 3+ The content relative to Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ The total content of cations [Al 3+ / (Mg2+ +Ca 2+ +Sr 2+ +Ba 2+ The upper limit of the cation ratio is preferably 5, and more preferably 4.0, 3.5, 3, 2.5, 2.0, 1.8, 1.6, 1.4, 1.2, 1.0, 0.8, 0.6, 0.4, 0.3, and 0.2. The lower limit of the cation ratio is preferably 0, and more preferably 0.05, 0.1, and 0.15. The cation ratio can be 0.

[0262] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Al 3+ The content relative to Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ The total content of cations [Al 3+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ The upper limit of the cation ratio is preferably 2, and more preferably 1.8, 1.6, 1.4, 1.2, 1.0, 0.8, 0.6, 0.4, 0.3, or 0.2. The lower limit of the cation ratio is preferably 0, and more preferably 0.05, 0.1, or 0.15. The cation ratio may be 0.

[0263] By increasing the cation ratio [Al 3+ / (Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ )] to improve the mechanical properties and chemical durability of the glass. On the other hand, if the cation ratio is too high, the liquidus temperature rises and the thermal stability of the glass is impaired. From the perspective of maintaining the thermal stability and resistance to devitrification of the glass, it is preferred that the cation ratio be within the above range.

[0264] In the optical glass of this embodiment, Al 3+ The content relative to Li + 、Na + , K + Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ The total content of cations [Al 3+ / (Li + +Na + +K + +Mg 2+ +Ca 2+ +Sr2+ +Ba 2+ The upper limit of the cation ratio is preferably 5, and more preferably 4, 3, 2, 1.8, 1.6, 1.4, 1.2, 1.0, 0.8, 0.6, 0.4, 0.3, and 0.2. The lower limit of the cation ratio is preferably 0, and more preferably 0.05, 0.1, and 0.15. The cation ratio can be 0.

[0265] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Al 3+ The content relative to Li + 、Na + , K + Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ The total content of cations [Al 3+ / (Li + +Na + +K + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ The upper limit of the cation ratio is preferably 5, and more preferably 4, 3, 2, 1.8, 1.6, 1.4, 1.2, 1.0, 0.8, 0.6, 0.4, 0.3, and 0.2. The lower limit of the cation ratio is preferably 0, and more preferably 0.05, 0.1, and 0.15. The cation ratio can be 0.

[0266] By increasing the cation ratio [Al 3+ / (Li + +Na + +K + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ )] to improve the mechanical properties and chemical durability of the glass. On the other hand, if the cation ratio is too high, the liquidus temperature rises and the thermal stability of the glass is impaired. From the perspective of maintaining the thermal stability and resistance to devitrification of the glass, it is preferred that the cation ratio be within the above range.

[0267] In the optical glass of this embodiment, Al 3+ The content relative to La 3+ 、Gd 3+ and Y 3+ The total content of cations [Al 3+ / (La 3+ +Gd 3+ +Y 3+The upper limit of the cation ratio is preferably 2, and more preferably 1.8, 1.6, 1.4, 1.2, 1.0, 0.8, 0.6, 0.4, 0.3, or 0.2. The lower limit of the cation ratio is preferably 0, and more preferably 0.05, 0.1, or 0.15. The cation ratio may be 0.

[0268] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Al 3+ The content relative to La 3+ 、Gd 3+ and Y 3+ The total content of cations [Al 3+ / (La 3+ +Gd 3+ +Y 3+ The upper limit of the cation ratio is preferably 2, and more preferably 1.8, 1.6, 1.4, 1.2, 1.0, 0.8, 0.6, 0.4, 0.3, or 0.2. The lower limit of the cation ratio is preferably 0, and more preferably 0.05, 0.1, or 0.15. The cation ratio may be 0.

[0269] From the viewpoint of increasing the refractive index nd and suppressing the decrease in the thermal stability of the glass, it is preferred to increase the cation ratio [Al 3+ / (La 3+ +Gd 3+ +Y 3+ )] is set to the above range.

[0270] In the optical glass of this embodiment, Li + 、Na + and K + The total content relative to Si 4+ and B 3+ The total cation content ratio [(Li + +Na + +K + ) / (Si 4+ +B 3+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.35, 0.3, 0.25, 0.24, 0.23, 0.22, and 0.21. The lower limit of the cation ratio is preferably 0, and more preferably 0.05, 0.07, 0.09, 0.10, 0.11, 0.12, 0.13, and 0.14. The cation ratio may be 0.

[0271] In addition, from the perspective of obtaining optical glass with higher refractive index and higher dispersion, Li + 、Na + and K +The total content relative to Si 4+ and B 3+ The total cation content ratio [(Li + +Na + +K + ) / (Si 4+ +B 3+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.35, 0.3, 0.25, 0.2, 0.15, 0.1, 0.09, 0.08, 0.07, 0.06. The lower limit of the cation ratio is preferably 0, and more preferably 0.01, 0.02, 0.03, 0.04, 0.05. The cation ratio can be 0.

[0272] From the viewpoint of improving the chemical durability, mechanical properties and thermal stability of the glass, suppressing the decrease in stability during reheating, and obtaining an optical glass with a lowered glass transition temperature Tg, it is preferred to increase the cation ratio [(Li + +Na + +K + ) / (Si 4+ +B 3+ )] is set to the above range.

[0273] In the optical glass of this embodiment, Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ The total content relative to Si 4+ and B 3+ The total cation content ratio [(Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ) / (Si 4+ +B 3+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.48, 0.46, 0.45, 0.44, 0.43, 0.42, 0.41, 0.40, and 0.39. The lower limit of the cation ratio is preferably 0, and more preferably 0.1, 0.15, 0.17, 0.19, 0.21, 0.23, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, and 0.35.

[0274] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Mg 2+ , Ca 2+ 、Sr 2+And Ba 2+ The total content relative to Si 4+ and B 3+ The total cation content ratio [(Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ) / (Si 4+ +B 3+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.48, 0.46, 0.44, 0.42, 0.40, 0.38, 0.36, 0.34, 0.32, 0.30, 0.28, 0.26, 0.24, 0.22, 0.20, 0.18, 0.16, 0.14, and 0.12. The lower limit of the cation ratio is preferably 0.01, and more preferably 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, and 0.10.

[0275] From the viewpoint of suppressing the decrease in chemical durability, mechanical properties and thermal stability of the glass, it is preferred to increase the cation ratio [(Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ) / (Si 4+ +B 3+ )] is set to the above range.

[0276] In the optical glass of this embodiment, Li + 、Na + , K + Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ The total content relative to Si 4+ and B 3+ The total cation content ratio [(Li + +Na + +K + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ) / (Si 4+ +B 3+The lower limit of the cation ratio is preferably 0, and more preferably 0.01, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.46, 0.47, 0.48, 0.49, 0.50, 0.51, and 0.52. The upper limit of the cation ratio is preferably 2, and more preferably 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0, 0.9, 0.8, 0.7, 0.68, 0.66, 0.64, 0.62, 0.61, and 0.6. The cation ratio may be 0.

[0277] In addition, from the perspective of obtaining optical glass with higher refractive index and higher dispersion, Li + 、Na + , K + Mg 2+ , Ca 2+ 、Sr 2 + And Ba 2+ The total content relative to Si 4+ and B 3+ The total cation content ratio [(Li + +Na + +K + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2 + ) / (Si 4+ +B 3+ The lower limit of the cation ratio is preferably 0.01, and more preferably 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, and 0.10. The upper limit of the cation ratio is preferably 2, and more preferably 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.48, 0.46, 0.44, 0.42, 0.40, 0.38, 0.36, 0.34, 0.32, 0.30, 0.28, 0.26, 0.24, 0.22, 0.20, 0.18, 0.16, 0.14, and 0.12.

[0278] From the viewpoint of obtaining an optical glass having desired optical constants, suppressing volatilization of glass components in the melt, and lowering the glass transition temperature Tg, it is preferred to increase the cation ratio [(Li + +Na + +K + +Mg 2+ +Ca2+ +Sr 2+ +Ba 2+ ) / (Si 4+ +B 3+ )] is set to the above range.

[0279] In the optical glass of this embodiment, La 3+ 、Gd 3+ and Y 3+ The total content relative to Si 4+ and B 3+ The total cation content ratio [(La 3+ +Gd 3+ +Y 3+ ) / (Si 4+ +B 3+ The lower limit of the cation ratio is preferably 0.01, and more preferably 0.10, 0.20, 0.30, 0.40, 0.50, 0.55, 0.60, 0.65, 0.70, 0.72, 0.74, 0.76, 0.78, 0.80, 0.82, 0.84, 0.86, 0.88, 0.90, 0.92, 0.93, 0.94, and 0.95. The upper limit of the cation ratio is preferably 3, and more preferably 2.5, 2, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.35, 1.3, 1.25, 1.2, 1.15, 1.13, 1.11, 1.10, and 1.09.

[0280] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, La 3+ 、Gd 3+ and Y 3+ The total content relative to Si 4+ and B 3+ The total cation content ratio [(La 3+ +Gd 3+ +Y 3+ ) / (Si 4+ +B 3+ The lower limit of the cation ratio is preferably 0.01, and more preferably 0.10, 0.20, 0.30, 0.40, 0.50, 0.55, 0.60, 0.65, 0.70, 0.72, 0.74, 0.76, 0.78, 0.80, 0.82, 0.84, 0.86, 0.88, 0.90, 0.92, 0.93, 0.94, and 0.95. The upper limit of the cation ratio is preferably 3, and more preferably 2.5, 2, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.35, 1.3, 1.25, 1.2, 1.15, 1.13, 1.11, 1.10, and 1.09.

[0281] From the viewpoint of increasing the refractive index nd and suppressing the decrease in the thermal stability of the glass, it is preferred to increase the cation ratio [(La 3+ +Gd 3+ +Y 3+ ) / (Si 4+ +B 3+ )] is set to the above range.

[0282] In the optical glass of this embodiment, Li + 、Na + , K + Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ 、La 3+ 、Gd 3+ and Y 3+ The total content relative to Si 4+ and B 3+ The total cation content ratio [(Li + +Na + +K + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +La 3+ +Gd 3+ +Y 3+ ) / (S i4+ +B 3+ The lower limit of the cation ratio is preferably 0.01, and more preferably 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90, 1.00, 1.05, 1.10, 1.15, 1.20, 1.25, 1.30, 1.35, 1.40, 1.45, 1.50, and 1.55. The upper limit of the cation ratio is preferably 4, and more preferably 3, 2.5, 2.2, 2.0, 1.95, 1.90, 1.85, 1.80, 1.78, 1.76, 1.74, 1.72, 1.70, 1.68, 1.66, 1.64, and 1.62.

[0283] In addition, from the perspective of obtaining optical glass with higher refractive index and higher dispersion, Li + 、Na + , K + Mg 2+ , Ca 2+ 、Sr+、Ba 2+ 、La 3+ 、Gd 3+ and Y 3+The total content relative to Si 4+ and B 3+ The total cation content ratio [(Li + +Na + +K + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +La 3+ +Gd 3+ +Y 3+ ) / (Si 4+ +B 3+ The lower limit of the cation ratio is preferably 0.01, and more preferably 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90, 1.00, 1.05, 1.10, 1.13, and 1.15. The upper limit of the cation ratio is preferably 4, and more preferably 3, 2.5, 2.2, 2.0, 1.95, 1.90, 1.85, 1.80, 1.75, 1.70, 1.65, 1.60, 1.55, 1.50, 1.45, 1.40, 1.35, 1.30, 1.25, and 1.20.

[0284] From the viewpoint of obtaining an optical glass that suppresses volatilization of glass components during melting and has excellent chemical durability, mechanical properties, and thermal stability, it is preferred to increase the cation ratio [(Li + +Na + +K + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +La 3+ +Gd 3+ +Y 3 + ) / (Si 4+ +B 3+ )] is set to the above range.

[0285] In the optical glass of this embodiment, Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total content relative to Si 4+ and B 3+ The total cation content ratio [(Ti 4+ +Nb 5+ +W 6+ +Bi 3+ ) / (Si 4+ +B 3+The upper limit of the cation ratio is preferably 0.5, and more preferably 0.4, 0.3, 0.2, or 0.1. The lower limit of the cation ratio is preferably 0, and more preferably 0.01, 0.02, 0.03, or 0.04. The cation ratio may be 0.

[0286] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total content relative to Si 4+ and B 3+ The total cation content ratio [(Ti 4+ +Nb 5+ +W 6+ +Bi 3+ ) / (Si 4+ +B 3+ The upper limit of the cation ratio is preferably 0.5, and more preferably 0.4, 0.3, 0.2, or 0.1. The lower limit of the cation ratio is preferably 0, and more preferably 0.01, 0.02, 0.03, or 0.04. The cation ratio may be 0.

[0287] From the viewpoint of suppressing the decrease in the refractive index nd at the desired Abbe number νd, it is preferred to reduce the cation ratio [(Ti 4+ +Nb 5+ +W 6+ +Bi 3+ ) / (Si 4+ +B 3+ )] is set to the above range.

[0288] In the optical glass of this embodiment, Zr 4+ and Ta 5+ The total content relative to Si 4+ and B 3+ The total content of cation ratio [(Zr 4+ +Ta 5+ ) / (Si 4+ +B 3+ The upper limit of the cation ratio is preferably 0.5, and more preferably 0.4, 0.3, 0.2, or 0.1. The lower limit of the cation ratio is preferably 0, and more preferably 0.01, 0.02, 0.03, or 0.04. The cation ratio may be 0.

[0289] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Zr 4+ and Ta 5+ The total content relative to Si 4+ and B 3+The total content of cation ratio [(Zr 4+ +Ta 5+ ) / (Si 4+ +B 3+ The upper limit of the cation ratio is preferably 0.5, and more preferably 0.4, 0.3, 0.2, or 0.1. The lower limit of the cation ratio is preferably 0, and more preferably 0.01, 0.02, 0.03, or 0.04. The cation ratio may be 0.

[0290] From the viewpoint of maintaining the thermal stability of the glass and suppressing the decrease in the refractive index nd at the desired Abbe number νd, it is preferred to increase the cation ratio [(Zr 4+ +Ta 5+ ) / (Si 4+ +B 3+ )] is set to the above range.

[0291] In the optical glass of this embodiment, Li + 、Na + and K + The total content relative to Si 4+ 、B 3+ 、Ti 4+ 、Nb 5+ 、W 6 + and Bi 3+ The total cation content ratio [(Li + +Na + +K + ) / (Si 4+ +B 3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+) The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.35, 0.3, 0.25, 0.24, 0.23, 0.22, and 0.21. The lower limit of the cation ratio is preferably 0, and more preferably 0.05, 0.07, 0.09, 0.10, 0.11, 0.12, 0.13, and 0.14. The cation ratio can be 0.

[0292] In addition, from the perspective of obtaining optical glass with higher refractive index and higher dispersion, Li + 、Na + and K + The total content relative to Si 4+ 、B 3+ 、Ti 4+ 、Nb 5+ 、W 6+ and Bi3+ The total cation content ratio [(Li + +Na + +K + ) / (Si 4+ +B 3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.35, 0.3, 0.25, 0.2, 0.15, 0.1, 0.09, 0.08, 0.07, 0.06. The lower limit of the cation ratio is preferably 0, and more preferably 0.01, 0.02, 0.03, 0.04, 0.05. The cation ratio can be 0.

[0293] From the viewpoint of improving the chemical durability, mechanical properties and thermal stability of the glass, suppressing the decrease in stability during reheating, and obtaining an optical glass with a lowered glass transition temperature Tg, it is preferred to increase the cation ratio [(Li + +Na + +K + ) / (Si 4+ +B 3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ )] is set to the above range.

[0294] In the optical glass of this embodiment, Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ The total content relative to Si 4+ 、B 3+ 、Ti 4 + 、Nb 5+ 、W 6+ and Bi 3+ The total cation content ratio [(Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ) / (Si 4+ +B 3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3 +The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.48, 0.46, 0.45, 0.44, 0.43, 0.42, 0.41, 0.40, and 0.39. The lower limit of the cation ratio is preferably 0, and more preferably 0.1, 0.15, 0.17, 0.19, 0.21, 0.23, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, and 0.35.

[0295] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ The total content relative to Si 4+ 、B 3+ 、Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total cation content ratio [(Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ) / (Si 4+ +B 3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.48, 0.46, 0.44, 0.42, 0.40, 0.38, 0.36, 0.34, 0.32, 0.30, 0.28, 0.26, 0.24, 0.22, 0.20, 0.18, 0.16, 0.14, and 0.12. The lower limit of the cation ratio is preferably 0.01, and more preferably 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, and 0.10.

[0296] From the viewpoint of suppressing the decrease in chemical durability, mechanical properties and thermal stability of the glass, it is preferred to increase the cation ratio [(Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ) / (Si 4+ +B 3+ +Ti 4+ +Nb 5+ +W 6+ +Bi3+ )] is set to the above range.

[0297] In the optical glass of this embodiment, Li + 、Na + , K + Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ The total content relative to Si 4+ 、B 3+ 、Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total cation content ratio [(Li + +Na + +K + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ) / (Si 4+ +B 3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ The lower limit of the cation ratio is preferably 0, and more preferably 0.01, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.46, 0.47, 0.48, 0.49, 0.50, 0.51, and 0.52. The upper limit of the cation ratio is preferably 2, and more preferably 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0, 0.9, 0.8, 0.7, 0.68, 0.66, 0.64, 0.62, 0.61, and 0.6. The cation ratio may be 0.

[0298] In addition, from the perspective of obtaining optical glass with higher refractive index and higher dispersion, Li + 、Na + , K + Mg 2+ , Ca 2+ 、Sr 2 + And Ba 2+ The total content relative to Si 4+ 、B 3+ 、Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total cation content ratio [(Li+ +Na + +K + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ) / (Si 4+ +B 3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ The lower limit of the cation ratio is preferably 0.01, and more preferably 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, and 0.10. The upper limit of the cation ratio is preferably 2, and more preferably 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.48, 0.46, 0.44, 0.42, 0.40, 0.38, 0.36, 0.34, 0.32, 0.30, 0.28, 0.26, 0.24, 0.22, 0.20, 0.18, 0.16, 0.14, and 0.12.

[0299] From the viewpoint of obtaining an optical glass having desired optical constants, suppressing volatilization of glass components in the melt, and lowering the glass transition temperature Tg, it is preferred to increase the cation ratio [(Li + +Na + +K + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ) / (Si 4+ +B 3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ )] is set to the above range.

[0300] In the optical glass of this embodiment, La 3+ 、Gd 3+ and Y 3+ The total content relative to Si 4+ 、B 3+ 、Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total cation content ratio [(La 3+ +Gd 3+ +Y 3+ ) / (Si4+ +B 3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ The lower limit of the cation ratio is preferably 0.01, and more preferably 0.10, 0.20, 0.30, 0.40, 0.50, 0.55, 0.60, 0.65, 0.70, 0.72, 0.74, 0.76, 0.78, 0.80, 0.82, 0.84, 0.86, 0.88, 0.90, 0.92, 0.93, 0.94, and 0.95. The upper limit of the cation ratio is preferably 3, and more preferably 2.5, 2, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.35, 1.3, 1.25, 1.2, 1.15, 1.13, 1.11, 1.10, and 1.09.

[0301] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, La 3+ 、Gd 3+ and Y 3+ The total content relative to Si 4+ 、B 3+ 、Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total cation content ratio [(La 3+ +Gd 3+ +Y 3+ ) / (Si 4+ +B 3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ The lower limit of the cation ratio is preferably 0.01, and more preferably 0.10, 0.20, 0.30, 0.40, 0.50, 0.55, 0.60, 0.65, 0.70, 0.72, 0.74, 0.76, 0.78, 0.80, 0.82, 0.84, 0.86, 0.88, 0.90, 0.92, 0.93, 0.94, and 0.95. The upper limit of the cation ratio is preferably 3, and more preferably 2.5, 2, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.35, 1.3, 1.25, 1.2, 1.15, 1.13, 1.11, 1.10, 1.09, 1.08, 1.07, 1.06, and 1.05.

[0302] From the viewpoint of increasing the refractive index nd and suppressing the decrease in the thermal stability of the glass, it is preferred to increase the cation ratio [(La 3++Gd 3+ +Y 3+ ) / (Si 4+ +B 3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ )] is set to the above range.

[0303] In the optical glass of this embodiment, Li + 、Na + , K + Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ 、La 3+ 、Gd 3+ and Y 3+ The total content relative to Si 4+ 、B 3+ 、Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total cation content ratio [(Li + +Na + +K + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +La 3+ +Gd 3+ +Y 3+ ) / (Si 4+ +B 3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ The lower limit of the cation ratio is preferably 0.01, and more preferably 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90, 1.00, 1.05, 1.10, 1.15, 1.20, 1.25, 1.30, 1.35, 1.40, 1.45, 1.50, and 1.55. The upper limit of the cation ratio is preferably 4, and more preferably 3, 2.5, 2.2, 2.0, 1.95, 1.90, 1.85, 1.80, 1.78, 1.76, 1.74, 1.72, 1.70, 1.68, 1.66, 1.64, and 1.62.

[0304] In addition, from the perspective of obtaining optical glass with higher refractive index and higher dispersion, Li + 、Na+ , K + Mg 2+ , Ca 2+ 、Sr 2 + 、Ba 2+ 、La 3+ 、Gd 3+ and Y 3+ The total content relative to Si 4+ 、B 3+ 、Ti 4+ 、Nb 5+ 、W 6+ and Bi 3+ The total cation content ratio [(Li + +Na + +K + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +La 3+ +Gd 3+ +Y 3+ ) / (Si 4+ +B 3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ The lower limit of the cation ratio is preferably 0.01, and more preferably 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90, 1.00, 1.02, 1.04, 1.06, and 1.08. The upper limit of the cation ratio is preferably 4, and more preferably 3, 2.5, 2.2, 2.0, 1.95, 1.90, 1.85, 1.80, 1.75, 1.70, 1.65, 1.60, 1.55, 1.50, 1.45, 1.40, 1.35, 1.30, 1.25, 1.20, and 1.15.

[0305] From the viewpoint of obtaining an optical glass that suppresses volatilization of glass components during melting and has excellent chemical durability, mechanical properties, and thermal stability, it is preferred to increase the cation ratio [(Li + +Na + +K + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +La 3+ +Gd 3+ +Y 3 + ) / (Si 4+ +B3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ )] is set to the above range.

[0306] In the optical glass of this embodiment, Li + 、Na + and K + The total content relative to Si 4+ 、B 3+ 、Ti 4+ 、Nb 5+ 、W 6 + 、Bi 3+ 、Zr 4+ and Ta 5+ The total cation content ratio [(Li + +Na + +K + ) / (Si 4+ +B 3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ +Zr 4+ +Ta 5+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.35, 0.3, 0.25, 0.24, 0.23, 0.22, and 0.21. The lower limit of the cation ratio is preferably 0, and more preferably 0.05, 0.07, 0.09, 0.10, 0.11, 0.12, 0.13, and 0.14. The cation ratio may be 0.

[0307] In addition, from the perspective of obtaining optical glass with higher refractive index and higher dispersion, Li + 、Na + and K + The total content relative to Si 4+ 、B 3+ 、Ti 4+ 、Nb 5+ 、W 6+ 、Bi 3+ 、Zr 4+ and Ta 5+ The total cation content ratio [(Li + +Na + +K + ) / (Si 4+ +B 3+ +Ti 4+ +Nb 5++W 6+ +Bi 3+ +Zr 4+ +Ta 5+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.35, 0.3, 0.25, 0.2, 0.15, 0.1, 0.09, 0.08, 0.07, 0.06. The lower limit of the cation ratio is preferably 0, and more preferably 0.01, 0.02, 0.03, 0.04, 0.05. The cation ratio can be 0.

[0308] From the viewpoint of improving the chemical durability, mechanical properties and thermal stability of the glass, suppressing the decrease in stability during reheating, and obtaining an optical glass with a lowered glass transition temperature Tg, it is preferred to increase the cation ratio [(Li + +Na + +K + ) / (Si 4+ +B 3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ +Zr 4+ +Ta 5+ )] is set to the above range.

[0309] In the optical glass of this embodiment, Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ The total content relative to Si 4+ 、B 3+ 、Ti 4 + 、Nb 5+ 、W 6+ 、Bi 3+ 、Zr 4+ and Ta 5+ The total cation content ratio [(Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ) / (Si 4+ +B 3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ +Zr 4+ +Ta 5+The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.48, 0.46, 0.45, 0.44, 0.43, 0.42, 0.41, 0.40, and 0.39. The lower limit of the cation ratio is preferably 0, and more preferably 0.05, 0.10, 0.15, 0.17, 0.19, 0.21, 0.23, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, and 0.35.

[0310] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ The total content relative to Si 4+ 、B 3+ 、Ti 4+ 、Nb 5+ 、W 6+ 、Bi 3+ 、Zr 4+ and Ta 5+ The total cation content ratio [(Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ) / (Si 4+ +B 3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ +Zr 4+ +Ta 5+ The upper limit of the cation ratio is preferably 1, and more preferably 0.9, 0.8, 0.7, 0.6, 0.5, 0.48, 0.46, 0.44, 0.42, 0.40, 0.38, 0.36, 0.34, 0.32, 0.30, 0.28, 0.26, 0.24, 0.22, 0.20, 0.18, 0.16, 0.14, and 0.12. The lower limit of the cation ratio is preferably 0.01, and more preferably 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, and 0.09.

[0311] From the viewpoint of suppressing the decrease in chemical durability, mechanical properties and thermal stability of the glass, it is preferred to increase the cation ratio [(Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ) / (Si 4+ +B3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ +Zr 4+ +Ta 5+ )] is set to the above range.

[0312] In the optical glass of this embodiment, Li + 、Na + , K + Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ The total content relative to Si 4+ 、B 3+ 、Ti 4+ 、Nb 5+ 、W 6+ 、Bi 3+ 、Zr 4+ and Ta 5+ The total cation content ratio [(Li + +Na + +K + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ) / (Si 4+ +B 3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ +Zr 4+ +Ta 5+ The lower limit of the cation ratio is preferably 0, and more preferably 0.01, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.46, 0.47, 0.48, 0.49, 0.50, 0.51, and 0.52. The upper limit of the cation ratio is preferably 2, and more preferably 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0, 0.9, 0.8, 0.7, 0.68, 0.66, 0.64, 0.62, 0.61, and 0.6. The cation ratio may be 0.

[0313] In addition, from the perspective of obtaining optical glass with higher refractive index and higher dispersion, Li + 、Na + , K + Mg 2+ , Ca 2+ 、Sr2 + And Ba 2+ The total content relative to Si 4+ 、B 3+ 、Ti 4+ 、Nb 5+ 、W 6+ 、Bi 3+ 、Zr 4+ and Ta 5+ The total cation content ratio [(Li + +Na + +K + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ) / (Si 4+ +B 3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ +Zr 4+ +Ta 5+ The lower limit of the cation ratio is preferably 0.01, and more preferably 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, and 0.09. The upper limit of the cation ratio is preferably 2, and more preferably 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.48, 0.46, 0.44, 0.42, 0.40, 0.38, 0.36, 0.34, 0.32, 0.30, 0.28, 0.26, 0.24, 0.22, 0.20, 0.18, 0.16, 0.14, and 0.12.

[0314] From the viewpoint of obtaining an optical glass having desired optical constants, suppressing volatilization of glass components in the melt, and lowering the glass transition temperature Tg, it is preferred to increase the cation ratio [(Li + +Na + +K + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ) / (Si 4+ +B 3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ +Zr 4+ +Ta 5+ )] is set to the above range.

[0315] In the optical glass of this embodiment, La 3+ 、Gd 3+ and Y 3+ The total content relative to Si 4+ 、B 3+ 、Ti 4+ 、Nb 5+ 、W 6+ 、Bi 3+ 、Zr 4+ and Ta 5+ The total cation content ratio [(La 3+ +Gd 3+ +Y 3+ ) / (Si 4+ +B 3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ +Zr 4+ +Ta 5+ The lower limit of the cation ratio is preferably 0.01, and more preferably 0.10, 0.20, 0.30, 0.40, 0.50, 0.55, 0.60, 0.65, 0.70, 0.72, 0.74, 0.76, 0.78, 0.80, 0.82, 0.84, 0.86, 0.88, 0.90, 0.92, 0.93, 0.94, and 0.95. The upper limit of the cation ratio is preferably 3, and more preferably 2.5, 2, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.35, 1.3, 1.25, 1.2, 1.15, 1.13, 1.11, 1.10, and 1.09.

[0316] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, La 3+ 、Gd 3+ and Y 3+ The total content relative to Si 4+ 、B 3+ 、Ti 4+ 、Nb 5+ 、W 6+ 、Bi 3+ 、Zr 4+ and Ta 5+ The total cation content ratio [(La 3+ +Gd 3+ +Y 3+ ) / (Si 4+ +B 3+ +Ti 4+ +Nb 5+ +W 6++Bi 3+ +Zr 4+ +Ta 5+ )] has a lower limit of preferably 0.01, and more preferably 0.10, 0.20, 0.30, 0.40, 0.50, 0.55, 0.60, 0.65, 0.70, 0.72, 0.74, 0.76, 0.78, 0.80, 0.82, 0.84, 0.86, 0.88, 0.90, 0.92, and 0.93, respectively. The upper limit of the cation ratio is preferably 3, and more preferably 2.5, 2, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.35, 1.3, 1.25, 1.2, 1.15, 1.13, 1.11, 1.10, 1.09, 1.08, 1.07, 1.06, 1.05, 1.04, 1.03, 1.02, 1.01, 1.00, 0.99, 0.98, 0.97, 0.96, and 0.95, in this order.

[0317] From the viewpoint of increasing the refractive index nd and suppressing the decrease in the thermal stability of the glass, it is preferred to increase the cation ratio [(La 3+ +Gd 3+ +Y 3+ ) / (Si 4+ +B 3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ +Zr 4+ +Ta 5+ )] is set to the above range.

[0318] In the optical glass of this embodiment, Li + 、Na + , K + Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ 、La 3+ 、Gd 3+ and Y 3+ The total content relative to Si 4+ 、B 3+ 、Ti 4+ 、Nb 5+ 、W 6+ 、Bi 3+ 、Zr 4+ and Ta 5+ The total cation content ratio [(Li + +Na + +K + +Mg 2+ +Ca2+ +Sr 2+ +Ba 2+ +La 3+ +Gd 3+ +Y 3+ ) / (Si 4+ +B 3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ +Zr 4+ +Ta 5+ The lower limit of the cation ratio is preferably 0.50, and more preferably 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, 1.00, 1.05, 1.10, 1.15, 1.20, 1.25, 1.30, 1.35, 1.40, 1.45, 1.50, and 1.55. The upper limit of the cation ratio is preferably 5.00, and more preferably 4.00, 3.00, 2.50, 2.30, 2.20, 2.10, 2.00, 1.95, 1.90, 1.85, 1.80, 1.78, 1.76, 1.74, 1.72, 1.70, 1.68, 1.66, 1.64, and 1.62.

[0319] In addition, from the perspective of obtaining optical glass with higher refractive index and higher dispersion, Li + 、Na + , K + Mg 2+ , Ca 2+ 、Sr 2 + 、Ba 2+ 、La 3+ 、Gd 3+ and Y 3+ The total content relative to Si 4+ 、B 3+ 、Ti 4+ 、Nb 5+ 、W 6+ 、Bi 3+ 、Zr 4+ and Ta 5+ The total cation content ratio [(Li + +Na + +K + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +La 3+ +Gd 3+ +Y 3+ ) / (Si4+ +B 3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ +Zr 4+ +Ta 5+ The lower limit of the cation ratio is preferably 0.01, and more preferably 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90, 0.92, 0.94, 0.96, 0.98, and 1.00. The upper limit of the cation ratio is preferably 4, and more preferably 3, 2.5, 2.2, 2.0, 1.95, 1.90, 1.85, 1.80, 1.75, 1.70, 1.65, 1.60, 1.55, 1.50, 1.45, 1.40, 1.35, 1.30, 1.25, 1.20, 1.15, 1.13, 1.11, 1.10, 1.09, 1.08, 1.07, and 1.06.

[0320] From the viewpoint of obtaining an optical glass that suppresses volatilization of glass components during melting and has excellent chemical durability, mechanical properties, and thermal stability, it is preferred to increase the cation ratio [(Li + +Na + +K + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +La 3+ +Gd 3+ +Y 3+ ) / (Si 4+ +B 3+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ +Zr 4+ +Ta 5+ )] is set to the above range.

[0321] In the optical glass of this embodiment, La 3+ 、Gd 3+ 、Y 3+ 、Li + 、Na + , K + , Rb + 、Cs + Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ The total content relative to Si 4+ 、B3+ 、P 5+ 、Ti 4+ 、Nb 5+ 、W 6+ 、Bi 3+ 、Zr 4+ and Ta 5+ The total cation content ratio [(La 3+ +Gd 3+ +Y 3+ +Li + +Na + +K + +Rb + +Cs + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ) / (Si 4+ +B 3+ +P 5+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ +Zr 4+ +Ta 5+ The lower limit of the cation ratio is preferably 0.50, and more preferably 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.84, 0.85, 0.90, 0.95, 1.00, 1.05, 1.10, 1.15, 1.20, 1.25, 1.30, 1.35, 1.40, 1.45, 1.50, and 1.55. The upper limit of the cation ratio is preferably 5.00, and more preferably 4.00, 3.00, 2.50, 2.30, 2.20, 2.10, 2.00, 1.95, 1.90, 1.85, 1.80, 1.78, 1.76, 1.74, 1.72, 1.70, 1.68, 1.66, 1.64, and 1.62.

[0322] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, La 3+ 、Gd 3+ 、Y 3+ 、Li + 、Na + , K + , Rb + 、Cs + Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ The total content relative to Si 4+ 、B 3+、P 5+ 、Ti 4+ 、Nb 5+ 、W 6+ 、Bi 3+ 、Zr 4+ and Ta 5+ The total cation content ratio [(La 3+ +Gd 3+ +Y 3+ +Li + +Na + +K + +Rb + +Cs + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ) / (Si 4+ +B 3+ +P 5+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ +Zr 4+ +Ta 5+ The lower limit of the cation ratio is preferably 0.83, and more preferably 0.85, 0.87, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, and 1.00. The upper limit of the cation ratio is preferably 5.00, and more preferably 4.00, 3.00, 2.50, 2.30, 2.10, 2.00, 1.90, 1.85, 1.80, 1.75, 1.70, 1.65, 1.60, 1.55, 1.50, 1.45, 1.40, 1.35, 1.30, 1.25, 1.20, 1.15, and 1.10.

[0323] If the cation ratio [(La 3+ +Gd 3+ +Y 3+ +Li + +Na + +K + +Rb + +Cs + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ) / (Si 4+ +B 3+ +P 5+ +Ti 4+ +Nb 5+ +W6+ +Bi 3+ +Zr 4+ +Ta 5+ If the cation ratio is too small, there is a risk of increased volatilization of the glass components. In addition, if the cation ratio is too large, there is a risk of reduced thermal stability of the glass. From the perspective of suppressing the volatilization of the glass components, it is preferred that the cation ratio be within the above range.

[0324] In the optical glass of this embodiment, P 5+ The upper limit of the content of is preferably 30%, and more preferably 20%, 10%, 8%, 6%, 5%, 4%, 3%, 2%, and 1%. 5+ The lower limit of the content of is preferably 0%, and more preferably 0.05%, 0.1%, and 0.5%. 5+ The content can be 0%.

[0325] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, P 5+ The upper limit of the content of is preferably 30%, and more preferably 20%, 10%, 8%, 6%, 5%, 4%, 3%, 2%, and 1%. 5+ The lower limit of the content of is preferably 0%, and more preferably 0.05%, 0.1%, and 0.5%. 5+ The content can be 0%.

[0326] By putting P 5+ When the content of MgO is within the above range, glass with relatively high mechanical properties and chemical durability can be obtained.

[0327] In the optical glass of this embodiment, Al 3+ The upper limit of the content of Al is preferably 30%, and more preferably 20%, 13%, 10%, 8%, 6%, 5%, 4%, 3%, 2%, and 1%. 3+ The lower limit of the content of Al is preferably 0%, and more preferably 0.05%, 0.1%, and 0.5% in that order. 3+ The content can be 0%.

[0328] In addition, from the perspective of obtaining optical glass with higher refractive index and higher dispersion, Al 3+ The upper limit of the content of Al is preferably 30%, and more preferably 20%, 10%, 8%, 6%, 5%, 4%, 3%, 2%, and 1%. 3+ The lower limit of the content of Al is preferably 0%, and more preferably 0.05%, 0.1%, and 0.5% in that order. 3+ The content can be 0%.

[0329] By containing an appropriate amount of Al 3+ , which has the function of inhibiting the phase separation of glass. In addition, by increasing Al 3+ The content of Al can improve the mechanical properties and chemical durability of the glass. 3+ If the content of Al is too high, the liquidus temperature will rise and the thermal stability of the glass will be impaired. When the liquidus temperature rises, the volatilization of glass components during glass flow and molding will increase, causing wave lines to form. From the perspective of maintaining the thermal stability of the glass, it is preferred to add Al 3+ The content of is set within the above range.

[0330] In the optical glass of this embodiment, Si 4+ The content of Si is preferably greater than 0%, and its lower limit is preferably 1%, and further preferably 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, and 10%. 4+ The upper limit of the content is preferably 30%, and more preferably 25%, 23%, 21%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, and 13% in this order.

[0331] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Si 4+ The content of Si is preferably greater than 0%, and its lower limit is preferably 1%, and further preferably 1.5%, 2%, 2.5%, 3%, 3.5%, and 4%. 4+ The upper limit of the content is preferably 30%, and more preferably 25%, 23%, 21%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, and 7%.

[0332] Si 4+ It is the network forming component of glass. 4+ If the content of Si is too low, there is a risk of reducing the chemical durability, mechanical properties and thermal stability of the glass. 4+ If the content of Si is too high, there is a risk of reducing the solubility of the glass and the refractive index nd. In addition, there is a risk of reducing the thermal stability of the glass and increasing the glass transition temperature Tg. Therefore, from the perspective of obtaining an optical glass with improved abnormal partial dispersion, chemical durability, mechanical properties and thermal stability, it is preferred to reduce Si. 4+ The content of is set within the above range.

[0333] In the glass of this embodiment, Li +The upper limit of the content of is preferably 40%, and more preferably 30%, 20%, 17%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, and 8%. + The lower limit of the content of Li is preferably 0%, and more preferably 1%, 2%, 3%, 4%, 4.5%, 5%, 5.5%, 6%, and 6.5%. + The content can be 0%.

[0334] In addition, from the perspective of obtaining optical glass with higher refractive index and higher dispersion, Li + The upper limit of the content of is preferably 40%, and more preferably 30%, 20%, 17%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, and 2%. + The lower limit of the content of Li is preferably 0%, and more preferably 0.01%, 0.05%, 0.1%, 0.5%, and 1% in this order. + The content can be 0%.

[0335] Li + It is a component that helps to reduce the viscosity of glass. + If the content of Li is too high, there is a risk of decreased thermal stability of the glass and stability during reheating. + If the content of Li is too low, there is a risk of increasing the glass transition temperature Tg. + The content of is preferably within the above range.

[0336] In the glass of this embodiment, Na + The upper limit of the content of Na is preferably 40%, and more preferably 30%, 20%, 10%, 8%, 6%, 5%, 4%, 3%, 2%, 1%, and 0.5%. + The lower limit of the content of Na is preferably 0%, and more preferably 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, and 0.35%. + The content can be 0%.

[0337] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Na + The upper limit of the content of Na is preferably 40%, and more preferably 30%, 20%, 10%, 8%, 6%, 5%, 4%, 3%, 2%, 1%, and 0.5%. + The lower limit of the content of Na is preferably 0%, and more preferably 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, and 0.35%.+ The content can be 0%.

[0338] With Li + Similarly, Na + It is a component that helps to reduce the viscosity of glass. + If the content of Na is too high, there is a risk of reducing the thermal stability of the glass and the stability during reheating. + The content of is preferably within the above range.

[0339] In the optical glass of this embodiment, K + The upper limit of the content of is preferably 40%, and more preferably 30%, 20%, 10%, 8%, 6%, 5%, 4%, 3%, 2%, 1%, and 0.5%. + The lower limit of the content of K is preferably 0%, and more preferably 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, and 0.35%. + The content can be 0%.

[0340] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, K + The upper limit of the content of is preferably 40%, and more preferably 30%, 20%, 10%, 8%, 6%, 5%, 4%, 3%, 2%, 1%, and 0.5%. + The lower limit of the content of K is preferably 0%, and more preferably 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, and 0.35%. + The content can be 0%.

[0341] K + It has the function of lowering the liquidus temperature and improving the thermal stability of the glass. On the other hand, if K + If the content of K is too high, the chemical durability, weather resistance and stability during reheating will be reduced. + The content of is preferably within the above range.

[0342] In the optical glass of this embodiment, Rb + The upper limit of the content of Rb is preferably 40%, and more preferably 30%, 20%, 10%, 8%, 6%, 5%, 4%, 3%, 2%, 1%, and 0.5%. + The lower limit of the content of Rb is preferably 0%. + The content can be 0%.

[0343] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Rb +The upper limit of the content of Rb is preferably 40%, and more preferably 30%, 20%, 10%, 8%, 6%, 5%, 4%, 3%, 2%, 1%, and 0.5%. + The lower limit of the content of Rb is preferably 0%. + The content can be 0%.

[0344] If Rb + If the content of Rb increases, the volatilization of glass components during melting increases, and the desired glass cannot be obtained. In addition, since Rb is an expensive component, + The content of is preferably within the above range.

[0345] In the optical glass of this embodiment, Cs + The upper limit of the content of Cs is preferably 40%, and more preferably 30%, 20%, 10%, 8%, 6%, 5%, 4%, 3%, 2%, 1%, and 0.5%. + The lower limit of the content of is preferably 0%. + The content can be 0%.

[0346] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Cs + The upper limit of the content of Cs is preferably 40%, and more preferably 30%, 20%, 10%, 8%, 6%, 5%, 4%, 3%, 2%, 1%, and 0.5%. + The lower limit of the content of is preferably 0%. + The content can be 0%.

[0347] If Cs + If the content of Cs increases, the volatilization of glass components during melting increases, and the desired glass cannot be obtained. In addition, there is a risk of reduced chemical durability and weather resistance. Therefore, Cs + The content of is preferably within the above range.

[0348] In the optical glass of this embodiment, Mg 2+ The upper limit of the content of Mg is preferably 40%, and more preferably 30%, 20%, 15%, 13%, 11%, 10%, 9%, 8%, 7%, 6.5%, and 6%. 2+ The lower limit of the content of Mg is preferably 0%, and more preferably 1%, 2%, 3%, and 4%. 2+ The content can be 0%.

[0349] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Mg 2+The upper limit of the content of Mg is preferably 40%, and more preferably 30%, 20%, 15%, 13%, 11%, 10%, 9%, 8%, 7%, 6.5%, and 6%. 2+ The lower limit of the content of Mg is preferably 0%, and more preferably 1%, 2%, 3%, and 4%. 2+ The content can be 0%.

[0350] If Mg 2+ If the content of Mg is too high, there is a risk of reducing the thermal stability and devitrification resistance of the glass. 2+ If the content of Mg is too low, there is a risk that the stability of the glass will decrease during reheating. 2+ The content of is preferably within the above range.

[0351] In the optical glass of this embodiment, Ca 2+ The upper limit of the content of Ca is preferably 25%, and more preferably 20%, 15%, 10%, 9%, 8%, 7%, 6%, and 5%. 2+ The lower limit of the content of Ca is preferably 0%, and more preferably 0.5%, 1%, and 2%. 2+ The content can be 0%.

[0352] In addition, from the viewpoint of obtaining an optical glass with a higher refractive index and high dispersion, Ca 2+ The upper limit of the content of Ca is preferably 25%, and more preferably 20%, 15%, 10%, 9%, 8%, 7%, 6%, and 5%. 2+ The lower limit of the content of Ca is preferably 0%, and more preferably 0.5%, 1%, and 2%. 2+ The content can be 0%.

[0353] If Ca 2+ If the content of Ca is too high, the thermal stability of the glass will be impaired, and there is a risk of increasing the glass transition temperature Tg and the liquidus temperature TL. From the perspective of obtaining an optical glass with desired optical constants, it is preferred to reduce the content of Ca to 1. 2+ The content of is set within the above range.

[0354] In the optical glass of this embodiment, Sr 2+ The upper limit of the content of Sr is preferably 40%, and more preferably 30%, 20%, 10%, 8%, 6%, 5%, 4%, 3%, 2%, 1%, and 0.5%. 2+ The lower limit of the content of Sr is preferably 0%. 2+ The content can be 0%.

[0355] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Sr 2+ The upper limit of the content of Sr is preferably 40%, and more preferably 30%, 20%, 10%, 8%, 6%, 5%, 4%, 3%, 2%, 1%, and 0.5%. 2+ The lower limit of the content of Sr is preferably 0%. 2+ The content can be 0%.

[0356] Sr 2+ It is a component in alkaline earth metals that increases the refractive index nd. However, if Sr 2+ If the content of Sr is too high, there is a risk of reducing the thermal stability and devitrification resistance of the glass. 2+ The content of is preferably within the above range.

[0357] In the optical glass of this embodiment, Ba 2+ The upper limit of the content of Ba is preferably 40%, and more preferably 30%, 25%, 20%, 18%, 16%, 15%, 14%, 13%, 12%, and 11%. 2+ The lower limit of the content is preferably 0%, and more preferably 1%, 2%, 3%, 4%, 5%, 6%, 7%, and 8% in this order.

[0358] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Ba 2+ The upper limit of the content is preferably 40%, and more preferably 30%, 25%, 20%, 18%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, and 6%. 2+ The lower limit of the content is preferably 0%, and more preferably 1%, 2%, 3%, and 4% in that order.

[0359] Ba 2+ Ba is a component that increases the refractive index nd in alkaline earth metals and also increases the stability of glass by lowering the liquidus temperature when contained in an appropriate amount. 2+ If the content of Ba is too high, the thermal stability of the glass and the stability during reheating may be reduced. 2+ If the content of Ba is too low, there is a risk of reduced thermal stability of the glass and increased volatilization of glass components during melting. 2+ The content of is preferably within the above range.

[0360] In the optical glass of this embodiment, Zn 2+ The upper limit of the content of Zn is preferably 13%, and more preferably 10%, 8%, 6%, and 5% in that order. 2+The lower limit of the content of Zn is preferably 0%, and more preferably 0.5%, 1%, and 2% in that order. 2+ The content can be 0%.

[0361] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Zn 2+ The upper limit of the content of Zn is preferably 13%, and more preferably 10%, 8%, 6%, and 5% in that order. 2+ The lower limit of the content of Zn is preferably 0%, and more preferably 0.5%, 1%, and 2% in that order. 2+ The content can be 0%.

[0362] Zn 2+ It is a glass component that has the function of lowering the glass transition temperature Tg. 2+ If the content of Zn is too high, there is a risk of increased specific gravity, decreased thermal stability and chemical durability of the glass, and a further increase in the Abbe number will result in a risk of not being able to obtain the desired high refractive index characteristics. Therefore, from the perspective of obtaining an optical glass with an improved glass transition temperature Tg, it is preferred to add Zn 2+ The content of is set within the above range.

[0363] In the optical glass of this embodiment, La 3+ The lower limit of the content of La is preferably 5%, and more preferably 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 14.5%, 15%, 15.5%, 16%, 16.5%, 17%, and 17.5%. 3+ The upper limit of the content is preferably 50%, and more preferably 48%, 46%, 44%, 42%, 40%, 38%, 36%, 34%, 32%, 30%, 28%, 26%, 24%, 23%, 22%, 21.5%, 21%, 20.5%, and 20%.

[0364] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, La 3+ The lower limit of the content of La is preferably 5%, and more preferably 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, and 31%. 3+ The upper limit of the content is preferably 50%, and more preferably 49%, 48%, 47%, 46%, 45%, 44%, 43%, 42%, 41%, 40%, 39%, 38%, 37%, 36%, 35%, and 34% in that order.

[0365] By introducing a certain amount of La 3+ , which can inhibit the volatilization of glass components and increase the refractive index nd. However, if La 3+ If the content of La is too high, the thermal stability of the glass will decrease, and there is a hidden danger that the glass will easily lose clarity during manufacturing. 3+ The content of is preferably within the above range.

[0366] In the glass of this embodiment, Gd 3+ The upper limit of the content of Gd is preferably 50%, and more preferably 40%, 30%, 20%, 15%, 10%, 8%, 6%, 4%, 3%, 2%, and 1%. 3+ The lower limit of the content of Gd is preferably 0%. 3+ The content can be 0%.

[0367] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Gd 3+ The upper limit of the content of Gd is preferably 50%, and more preferably 45%, 40%, 35%, 30%, 28%, 26%, 24%, 22%, 20%, 18%, 16%, and 15%. 3+ The lower limit of the content is preferably 0%, and more preferably 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, and 12% in this order.

[0368] with La 3+ Similarly, by introducing a certain amount of Gd 3+ , can inhibit the volatilization of glass components and increase the refractive index nd. On the other hand, if Gd 3+ If the content of Gd is too high, the thermal stability of the glass will decrease. 3+ If the content of Gd is too high, the specific gravity of the glass will increase, which is not preferred. In addition, there is a hidden danger of increased raw material costs. Therefore, from the perspective of maintaining good thermal stability of the glass and suppressing the increase in specific gravity, as well as reducing the content of Gd as a heavy rare earth, the content of Gd is too high. 3+ Considering the content of Gd 3+ The content of is preferably within the above range.

[0369] In the glass of this embodiment, Y 3+ The upper limit of the content of is preferably 50%, and more preferably 48%, 46%, 44%, 42%, 40%, 38%, 36%, 34%, 32%, 30%, 28%, 26%, 25%, 24%, 23%, 22.5%, 22%, and 21.5%. 3+The lower limit of the content is preferably 0%, and more preferably 1%, 5%, 8%, 10%, 12%, 14%, 16%, and 18%. 3+ The content can be 0%.

[0370] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Y 3+ The upper limit of the content of is preferably 50%, and more preferably 48%, 46%, 44%, 42%, 40%, 38%, 36%, 34%, 32%, 30%, 28%, 26%, 24%, 22%, 20%, 18%, 16%, 14%, 12%, 10%, 8%, 6%, 5%, 4%, 3%, and 2%. Alternatively, Y 3+ The lower limit of the content of is preferably 0%, and more preferably 0.01%, 0.05%, 0.1%, 0.5%, and 1%. 3+ The content can be 0%.

[0371] By importing a certain amount of Y 3+ , which can inhibit the volatilization of glass components and increase the refractive index nd. However, if Y 3+ If the content of Y is too high, the thermal stability of the glass will decrease and the glass will be easily devitrified during production. 3+ If the content of Y is too low, there is a risk of reducing the thermal stability of the glass. Therefore, from the perspective of suppressing the reduction of the thermal stability of the glass, Y 3+ The content of is preferably within the above range.

[0372] In the glass of this embodiment, Yb 3+ The upper limit of the content of Yb is preferably 50%, and more preferably 40%, 30%, 20%, 15%, 10%, 8%, 6%, 4%, 3%, 2%, and 1%. 3+ The lower limit of the content of Yb is preferably 0%. 3+ The content can be 0%.

[0373] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Yb 3+ The upper limit of the content of Yb is preferably 50%, and more preferably 40%, 30%, 20%, 15%, 10%, 8%, 6%, 4%, 3%, 2%, and 1%. 3+ The lower limit of the content of Yb is preferably 0%. 3+ The content can be 0%.

[0374] Because of La 3+ 、Gd 3+ 、Y 3+ Compared with Yb 3+The molecular weight of Yb is large, so it will increase the specific gravity of the glass. 3+ If the content of Yb is too high, the thermal stability of the glass will decrease. From the perspective of preventing the decrease in thermal stability of the glass and suppressing the increase in specific gravity, Yb 3+ The content of is preferably within the above range.

[0375] In the optical glass of this embodiment, Ti 4+ The upper limit of the content of Ti is preferably 20%, and more preferably 15%, 10%, 5%, 4%, 3.5%, 3%, and 2.5%. 4+ The lower limit of the content of Ti is preferably 0%, and may further be 0.1%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4% or 1.6%. 4+ The content can be 0%.

[0376] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Ti 4+ The upper limit of the content of Ti is preferably 20%, and more preferably 15%, 10%, 5%, 4%, 3.5%, 3%, and 2.5%. 4+ The lower limit of the content is preferably 0%, and may further be 0.1%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4% or 1.6%.

[0377] From the viewpoint of maintaining the desired Abbe number νd and improving the anomalous partial dispersion in the visible to near ultraviolet region, it is preferred to 4+ The content of is set within the above range.

[0378] In the optical glass of this embodiment, Nb 5+ The upper limit of the content of Nb is preferably 20%, and more preferably 15%, 10%, 5%, 4%, 3.5%, 3%, and 2.5%. 5+ The lower limit of the content of Nb is preferably 0%, and more preferably 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4%, and 1.6%. 5+ The content can be 0%.

[0379] In addition, from the viewpoint of obtaining an optical glass with a higher refractive index and high dispersion, Nb 5+ The upper limit of the content of Nb is preferably 20%, and more preferably 15%, 10%, 5%, 4%, 3.5%, 3%, and 2.5%. 5+The lower limit of the content is preferably 0%, and more preferably 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4%, and 1.6%, respectively.

[0380] From the viewpoint of maintaining the desired Abbe number νd and improving the anomalous partial dispersion in the visible to near ultraviolet region, it is preferred to use Nb 5+ The content of is set within the above range.

[0381] In the optical glass of this embodiment, W 6+ The upper limit of the content of W is preferably 20%, and more preferably 15%, 10%, 5%, 4%, 3.5%, 3%, and 2.5% in this order. 6+ The lower limit of the content of W is preferably 0%, and more preferably 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4%, and 1.6%. 6+ The content can be 0%.

[0382] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, W 6+ The upper limit of the content of W is preferably 20%, and more preferably 15%, 10%, 5%, 4%, 3.5%, 3%, and 2.5% in this order. 6+ The lower limit of the content is preferably 0%, and more preferably 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4%, and 1.6%, respectively.

[0383] From the viewpoint of improving transmittance and reducing specific gravity, and from the viewpoint of maintaining a desired Abbe number νd and improving the anomalous partial dispersion in the visible to near ultraviolet region, it is preferred to 6+ The content of is set within the above range.

[0384] In the optical glass of this embodiment, Bi 3+ The upper limit of the content of Bi is preferably 20%, and more preferably 15%, 10%, 5%, 4%, 3.5%, 3%, and 2.5%. 3+ The lower limit of the content of Bi is preferably 0%, and may further be 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4% or 1.6%. 3+ The content can be 0%.

[0385] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Bi 3+ The upper limit of the content of Bi is preferably 20%, and more preferably 15%, 10%, 5%, 4%, 3.5%, 3%, and 2.5%. 3+The lower limit of the content of Bi is preferably 0%, and may further be 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4% or 1.6%. 3+ The content can be 0%.

[0386] From the perspectives of increasing transmittance and reducing specific gravity, reducing damage to platinum manufacturing equipment, and improving the anomalous partial dispersion in the visible to near-ultraviolet region, it is preferred to use Bi 3+ The content of is set within the above range.

[0387] In the optical glass of this embodiment, Zr 4+ The upper limit of the content of Zr is preferably 10%, and more preferably 8%, 6%, 4%, 3%, 2%, and 1% in that order. 4+ The lower limit of the content of Zr is preferably 0%, and more preferably 0.05%, 0.1%, and 0.5% in that order. 4+ The content can be 0%.

[0388] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Zr 4+ The upper limit of the content of Zr is preferably 10%, and more preferably 9%, 8%, 7%, 6%, 5%, and 4%. 4+ The lower limit of the content of Zr is preferably 0%, and more preferably 0.05%, 0.1%, 0.5%, 1.0%, 1.5%, and 2.0%. 4+ The content can be 0%.

[0389] By containing an appropriate amount of Zr 4+ It has the effect of improving chemical durability. However, if Zr 4+ If the content of Zr is too high, there is a risk of increasing the liquidus temperature LT and decreasing the solubility of the glass. 4+ The content of is set within the above range.

[0390] In the optical glass of this embodiment, Ta 5+ The upper limit of the content of Ta is preferably 10%, and more preferably 8%, 6%, 4%, 3%, 2%, and 1% in that order. 5+ The lower limit of the content of Ta is preferably 0%, and more preferably 0.05%, 0.1%, and 0.5% in that order. 5+ The content can be 0%.

[0391] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, Ta 5+ The upper limit of the content of Ta is preferably 10%, and more preferably 8%, 6%, 4%, 3%, 2%, and 1% in that order.5+ The lower limit of the content of Ta is preferably 0%, and more preferably 0.05%, 0.1%, and 0.5% in that order. 5+ The content can be 0%.

[0392] Ta 5+ It is a component that contributes to the high refractive index and low dispersion of glass. On the other hand, if Ta 5+ If the content of Ta is too high, there is a risk of increased raw material costs and a risk of decreased solubility of the glass. In addition, there is a risk of increased specific gravity. Therefore, Ta 5+ The content of is preferably within the above range.

[0393] In the optical glass of this embodiment, Ge 4+ The upper limit of the content of Ge is preferably 5%, and more preferably 4.5%, 4%, 3.5%, 3%, 2.5%, 2%, 1.5%, 1%, and 0.5%. 4+ The lower limit of the content of Ge is preferably 0%. 4+ The content can be 0%.

[0394] In addition, from the perspective of obtaining optical glass with higher refractive index and high dispersion, Ge 4+ The upper limit of the content of Ge is preferably 5%, and more preferably 4.5%, 4%, 3.5%, 3%, 2.5%, 2%, 1.5%, 1%, and 0.5%. 4+ The lower limit of the content of Ge is preferably 0%. 4+ The content can be 0%.

[0395] Ge 4+ Ge has the function of improving the high dispersion characteristics of glass and is an especially expensive component among the commonly used glass components. Therefore, from the perspective of reducing the manufacturing cost of glass, it is preferred to use Ge 4+ The content of is set within the above range.

[0396] In the glass of this embodiment, Sc 3+ The content of Sc is preferably 2% or less. 3+ The lower limit of the content is preferably 0%.

[0397] In the glass of this embodiment, Hf 4+ The content of Hf is preferably 2% or less. 4+ The lower limit of the content is preferably 0%.

[0398] Sc 3+ , Hf 4+ Although it has the effect of improving the high dispersion characteristics of glass, it is an expensive component. 3+ , Hf 4+The respective contents of are preferably within the above ranges.

[0399] In the glass of this embodiment, Lu 3+ The content of Lu is preferably 2% or less. 3+ The lower limit of the content is preferably 0%.

[0400] Lu 3+ It has the effect of improving the high dispersion of glass, and due to its high molecular weight, it is also a glass component that increases the specific gravity of glass. 3+ The content of is preferably within the above range.

[0401] The glass of this embodiment preferably contains Si as an essential component. 4+ and B 3+ , Ca as an optional component 2+ 、Zn 2+ 、P 5 + 、Al 3+ 、Li + 、Na + , K + , Rb + 、Cs + Mg 2+ 、Sr 2+ 、Ba 2+ 、La 3+ 、Gd 3+ 、Y 3+ 、Ti 4+ 、Nb 5+ 、W 6+ 、Bi 3+ 、Ta 5+ and Zr 4+ The total content of these glass components is preferably 95% or more, more preferably 98% or more, further preferably 99% or more, and particularly preferably 99.5% or more.

[0402] The optical glass of this embodiment includes O 2- As anionic component. 2- The upper limit of the content of is preferably 90 anions, and further more preferably 80 anions, 75 anions, 73 anions, 71 anions, 69 anions, 67 anions, 65 anions, 63 anions, 61 anions, 60 anions, 59 anions, 58 anions, 57 anions, 56 anions, and 55 anions. In addition, 2-The lower limit of the content is preferably 10% anion, and further preferably 15% anion, 20% anion, 25% anion, 30% anion, 32% anion, 34% anion, 36% anion, 38% anion, 40% anion, 42% anion, 44% anion, 45% anion, 46% anion, 47% anion, 48% anion, 49% anion, 50% anion, and 51% anion.

[0403] In addition, from the perspective of obtaining an optical glass with a higher refractive index and high dispersion, 2- The upper limit of the content of is preferably 90 anions, and further more preferably 88 anions, 86 anions, 84 anions, 82 anions, 80 anions, 78 anions, 76 anions, 75 anions, 74 anions, 73 anions, 72 anions, 71 anions, 70 anions, 69 anions, and 68 anions. In addition, 2- The lower limit of the content is preferably 10% anion, and further preferably 15% anion, 20% anion, 25% anion, 30% anion, 35% anion, 40% anion, 45% anion, 50% anion, 55% anion, 60% anion, 61% anion, 62% anion, 63% anion, 64% anion, and 65% anion.

[0404] The optical glass of this embodiment may contain 2- and F - As components other than O 2- and F - Other anion components include Cl - Br - , I - However, Cl - Br - , I - The volatilization of these components will cause the glass properties to change, the homogeneity of the glass to decrease, and the loss of melting equipment to become significant. - The content of Br is preferably less than 5% anion, more preferably less than 3% anion, further preferably less than 1% anion, particularly preferably less than 0.5% anion, and further preferably less than 0.25% anion. In addition, Br - and I - The total content of anions is preferably less than 5%, more preferably less than 3%, more preferably less than 1%, particularly preferably less than 0.5%, further preferably less than 0.1%, and even more preferably 0%.

[0405] The glass of this embodiment is preferably basically composed of the above-mentioned glass components, but may also contain other components within the range that does not impair the effects of the present invention. In addition, the present invention does not exclude the inclusion of inevitable impurities.

[0406] In the optical glass of present embodiment, from the viewpoint that the transmittance near the suppression wavelength 360nm and near the wavelength 375nm reduces, can add Sb ion.For the upper limit of the content of Sb ion, be preferably 1.0000 mass % with adding ratio, further more preferably 0.5000 mass %, 0.1000 mass %, 0.0900 mass %, 0.0800 mass %, 0.0700 mass %, 0.0600 mass %, 0.0500 mass %, 0.0400 mass %, 0.0300 mass %, 0.0250 mass %, 0.0200 mass %, 0.0150 mass %, 0.0100 mass %, 0.0090 mass %, 0.0080 mass %, 0.0070 mass %, 0.0060 mass %, 0.0050 mass %.In addition, the content of Sb ion is preferably more than 1.0 mass ppm with adding ratio.It should be noted that 1.0 mass ppm is 0.0001 mass %. The lower limit of the Sb ion content is more preferably 0.0005 mass % in terms of added proportion, and further preferably 0.0008 mass %, 0.0010 mass %, 0.0012 mass %, 0.0014 mass %, 0.0016 mass %, 0.0018 mass %, 0.0020 mass %, 0.0022 mass %, 0.0024 mass %, 0.0026 mass %, 0.0028 mass %, 0.0030 mass %, 0.0032 mass %, 0.0034 mass %, 0.0036 mass %, and 0.0038 mass %, in that order.

[0407] Sb ions can be added to the glass through, for example, Sb2O3 or Sb2S3. Sb ions include all Sb ions with trivalence, pentavalence, and other valence numbers. In addition, the content of Sb ions is an added ratio. That is, the content of Sb ions is expressed in mass % when the total content of all glass components other than Sb ions is set to 100 mass %. From the perspective of suppressing the reduction of transmittance near wavelengths of 360nm and 375nm, it is preferred to set the content of Sb ions to the above range. If the content of Sb ions is too high, Pt from the crucible is easily introduced into the glass, forming Pt colloids and producing Tyndall-like blur in the glass, which has the potential risk of deteriorating light transmittance that is independent of the wavelength range. In addition, there is a potential risk of deteriorating light transmittance of specific wavelengths due to the light absorption of the Sb ions themselves. In the case of no Sb ions or when the content of Sb ions is too low, the absorption of Pt ions near a wavelength of 360nm becomes significant. As a result, there is a potential risk of deteriorating light transmittance of specific wavelengths within the wavelength range extending to visible light.

[0408] Furthermore, the optical glass can achieve high transmittance across a wide range of the visible light region. To fully utilize this characteristic, it is preferably free of coloring elements. Examples of coloring elements include Cu, Co, Ni, Fe, Cr, Eu, Nd, Er, and V. The concentration of any of these elements is preferably less than 100 mass ppm, more preferably 0 to 80 mass ppm, even more preferably 0 to 50 mass ppm, and particularly preferably substantially absent.

[0409] Ga, Te, Tb, etc. are unnecessary components and are also expensive. Therefore, the range of the content of Ga2O3, TeO2, and TbO2 expressed in mass % is preferably 0 to 0.1%, more preferably 0 to 0.05%, further preferably 0 to 0.01%, further preferably 0 to 0.005%, even more preferably 0 to 0.001%, and particularly preferably substantially no Ga2O3, TeO2, and TbO2 are contained.

[0410] (Glass properties)

[0411] <Refractive Index nd>

[0412] For the optical glass of this embodiment, the refractive index nd is preferably 1.58 to 1.78, and may also be 1.59 to 1.75, 1.60 to 1.72, 1.61 to 1.69, 1.62 to 1.68, 1.63 to 1.67, 1.64 to 1.66, or 1.67 to 1.69. Furthermore, for optical glasses with higher refractive index and higher dispersion, the refractive index nd is preferably 1.60 to 1.92, and may also be 1.65 to 1.87, 1.70 to 1.82, 1.75 to 1.80, 1.76 to 1.79, or 1.65 to 1.68.

[0413] By appropriately adjusting the content of each glass component, the refractive index nd can be adjusted to a desired value. The component that has the effect of relatively increasing the refractive index nd (high refractive index component) is Nb 5+ 、Ti 4+ 、W 6+ 、Bi 3+ 、Zr 4+ 、Ta 5+ 、La 3+ 、Gd 3+ 、Y 3+ On the other hand, the component that has the effect of relatively lowering the refractive index nd (refractive index lowering component) is Si 4+ 、B 3+ 、Li + 、Na + , K + wait.

[0414] <Relative partial dispersion Pg,F>

[0415] In the optical glass of this embodiment, the lower limit of the relative partial dispersion Pg,F in the short wavelength region of visible light is preferably 0.5200, and more preferably 0.5250, 0.5300, 0.5350, 0.5400, 0.5410, 0.5420, 0.5430, 0.5440, and 0.5450, in this order.

[0416] Furthermore, for optical glasses with a higher refractive index and higher dispersion, the lower limit of the relative partial dispersion Pg,F in the short wavelength region of visible light is preferably 0.5200, and more preferably 0.5250, 0.5300, 0.5350, 0.5400, 0.5450, 0.5500, 0.5510, 0.5520, 0.5530, 0.5540, and 0.5550, respectively.

[0417] By setting the relative partial dispersion Pg,F within the above range, an optical glass suitable for compensating for high-order chromatic aberrations can be obtained. On the other hand, the upper limit of the relative partial dispersion Pg,F is not particularly limited, but is generally 0.5700, preferably 0.5650.

[0418] In the optical glass of this embodiment, the relative partial dispersion Pg,F preferably satisfies the following formula [3-1].

[0419] Pg,F≥0.6200-0.0014×νd···〔3-1〕

[0420] The relative partial dispersion Pg,F more preferably satisfies the following formula [3-2], and further more preferably satisfies the following formula [3-3], the following formula [3-4], the following formula [3-5], and the following formula [3-6] in this order.

[0421] Pg,F≥0.6220-0.0014×νd···〔3-2〕

[0422] Pg,F≥0.6240-0.0014×νd···〔3-3〕

[0423] Pg,F≥0.6260-0.0014×νd···〔3-4〕

[0424] Pg,F≥0.6270-0.0014×νd···〔3-5〕

[0425] Pg,F≥0.6280-0.0014×νd···〔3-6〕

[0426] In addition, in optical glasses with a higher refractive index and higher dispersion, the relative partial dispersion Pg,F preferably satisfies the following formula [4-1].

[0427] Pg,F≥0.6200-0.0014×νd···〔4-1〕

[0428] The relative partial dispersion Pg,F more preferably satisfies the following formula [4-2], and further more preferably satisfies the following formula [4-3], the following formula [4-4], the following formula [4-5], and the following formula [4-6] in this order.

[0429] Pg,F≥0.6220-0.0014×νd···〔4-2〕

[0430] Pg,F≥0.6230-0.0014×νd···〔4-3〕

[0431] Pg,F≥0.6240-0.0014×νd···〔4-4〕

[0432] Pg,F≥0.6250-0.0014×νd···〔4-5〕

[0433] Pg,F≥0.6260-0.0014×νd···〔4-6〕

[0434] In the optical element formed of the optical glass of this embodiment, from the viewpoint of satisfactorily compensating for chromatic aberration in a wide wavelength range, the relative partial dispersion Pg,F preferably satisfies the above-mentioned formula.

[0435] <Specific Gravity of Glass>

[0436] The specific gravity of the optical glass of this embodiment is preferably 6.0 or less, and more preferably 5.5 or less, 5.0 or less, 4.8 or less, and 4.6 or less. In addition, in optical glasses with higher refractive index and higher dispersion, the specific gravity is preferably 6.0 or less, and more preferably 5.9 or less, 5.8 or less, 5.7 or less, 5.6 or less, and 5.5 or less.

[0437] The component that relatively increases the specific gravity is Ba 2+ 、La 3+ 、Zr 4+ 、Nb 5+ 、Ta 5+ On the other hand, the component that relatively reduces the specific gravity is Si 4+ 、B 3+ 、Li + 、Na + Mg 2+ Etc. The specific gravity can be controlled by appropriately adjusting the contents of these ingredients.

[0438] <Liquid phase temperature LT>

[0439] The upper limit of the liquidus temperature LT of the optical glass of this embodiment is preferably 1200°C, and more preferably 1150°C, 1100°C, 1050°C, 1000°C, 980°C, 970°C, 960°C, 950°C, 940°C, 930°C, 920°C, 910°C, 900°C, and 890°C. Furthermore, for optical glasses with higher refractive index and higher dispersion, the upper limit of the liquidus temperature LT is preferably 1200°C, and more preferably 1190°C, 1180°C, 1170°C, 1160°C, 1150°C, 1140°C, 1130°C, and 1120°C.

[0440] By setting the liquidus temperature within the above range, the melting and forming temperatures of the glass can be lowered, resulting in reduced ripples caused by erosion of glass melting equipment (e.g., crucibles, stirring equipment for molten glass, etc.) and volatilization of the glass components themselves during the melting process. The lower limit of the liquidus temperature LT is not particularly limited. The liquidus temperature LT is determined by the balance of the contents of all glass components. 4+ 、B 3+ 、Li + 、Na + , K+ The content of Zr has a great influence on the liquidus temperature LT. 4+ 、Al 3+ When the content of etc. is high, the liquidus temperature rises.

[0441] The liquidus temperature is determined as follows. 10cc (10ml) of glass is placed in a platinum crucible and melted at a temperature above 1200°C for 15-30 minutes. After cooling to below the glass transition temperature (Tg), the glass and the platinum crucible are placed in a melting furnace at a predetermined temperature and held for 2 hours. The temperature is set to an arbitrary value in 10°C increments. After holding for 2 hours, the glass is cooled and observed under a 100x optical microscope for the presence of crystals within the glass. This procedure is repeated at various temperatures, and the lowest temperature at which crystallization does not occur is defined as the liquidus temperature.

[0442] <Light Transmittance of Glass>

[0443] The light transmittance of the optical glass of this embodiment can be evaluated based on the coloration degrees λ80, λ70, and λ5.

[0444] For a glass sample with a thickness of 10.0 mm ± 0.1 mm, the spectral transmittance was measured in the wavelength range of 200 to 700 nm. The wavelength at which the external transmittance reached 80% was designated as λ80, the wavelength at which the external transmittance reached 70% was designated as λ70, and the wavelength at which the external transmittance reached 5% was designated as λ5.

[0445] The optical glass of this embodiment preferably has a λ80 of 450 nm or less, more preferably 400 nm or less, and even more preferably 350 nm or less. The λ70 is preferably 430 nm or less, more preferably 380 nm or less, and even more preferably 330 nm or less. The λ5 is preferably 380 nm or less, more preferably 330 nm or less, and even more preferably 280 nm or less.

[0446] Furthermore, for optical glasses with higher refractive index and higher dispersion, λ80 is preferably 450 nm or less, more preferably 400 nm or less, and even more preferably 380 nm or less. λ70 is preferably 430 nm or less, more preferably 380 nm or less, and even more preferably 360 nm or less. λ5 is preferably 380 nm or less, more preferably 330 nm or less, and even more preferably 320 nm or less.

[0447] <Chemical durability and acid resistance Da>

[0448] In the optical glass of this embodiment, the acid resistance Da is preferably level 5 or higher, more preferably level 4 or higher, and even more preferably level 3 or higher.

[0449] Acid resistance Da was evaluated by placing a mass of powdered glass (particle size 425-600 μm) equivalent to its specific gravity in a platinum cage and immersing it in a quartz glass round-bottom flask containing 80 mL of a 0.01 mol / L aqueous nitric acid solution for 60 minutes. The weight reduction (%) was then classified into the grades shown in Table B.

[0450]

[0451] <Chemical durability and water resistance Dw>

[0452] In the optical glass of this embodiment, the water resistance Dw is preferably level 5 or higher, more preferably level 4 or higher, and even more preferably level 3 or higher.

[0453] Water resistance Dw was evaluated by placing a mass of powdered glass (particle size 425-600 μm) equivalent to its specific gravity in a platinum cage, immersing it in 80 mL of pure water (pH = 6.5-7.5) in a quartz glass round-bottom flask, and treating it in a boiling water bath for 60 minutes. The mass reduction rate (%) was then classified into the grades shown in Table C.

[0454]

[0455] <ΔT360>

[0456] In the optical glass of this embodiment, when the thickness is set to 10.0mm±0.1mm, the upper limit of the difference (ΔT360) between the external transmittance at a wavelength of 700nm and the external transmittance at a wavelength of 360nm is preferably 31.0%, and further preferably 30.0%, 28.0%, 26.0%, 24.0%, 22.0%, 20.0%, 18.0%, 16.0%, 15.0%, 14.0%, 13.0%, 12.0%, 11.0%, 10.0%, 9.0%, 8.0%, 7.0%, and 6.0%. The lower limit of ΔT360 is not particularly limited and is generally 2 to 30%. ΔT360 can be adjusted by introducing Sb ions. In addition, from the viewpoint of maintaining low dispersion, it is not preferred to use high dispersion components such as Ti, Nb, W, and Bi. When these are introduced for the purposes of high refractive index and high anomalous dispersion, ΔT360 will increase. By setting ΔT360 within the above range, a decrease in transmittance around a wavelength of 360 nm can be suppressed.

[0457] <ΔT375>

[0458] In the optical glass of this embodiment, when the thickness is set to 10.0mm±0.1mm, the upper limit of the difference (ΔT375) between the external transmittance at a wavelength of 700nm and the external transmittance at a wavelength of 375nm is preferably 15.0%, and further preferably 13.0%, 11.0%, 10.0%, 9.0%, 8.0%, 7.5%, 7.0%, 6.8%, 6.7%, 6.6%, 6.5%, 6.4%, 6.3%, 6.2%, 6.1%, and 6.0%. The lower limit of ΔT375 is not particularly limited and is generally 2~15%. ΔT375 can be adjusted by introducing Sb ions. In addition, when high dispersion components such as Ti, Nb, W, and Bi are introduced for the purpose of high refractive index and high anomalous dispersion, ΔT375 will increase. By setting ΔT375 to the above range, the reduction of transmittance near a wavelength of 375nm can be suppressed.

[0459] External transmittance is defined as the ratio of the transmitted light intensity to the incident light intensity when light is incident along the thickness of the glass sample [transmitted light intensity / incident light intensity × 100]. Note that external transmittance also includes light reflection losses at the sample surface.

[0460] (Manufacturing of optical glass)

[0461] The glass of this embodiment is prepared by mixing glass raw materials in a manner to achieve the above-mentioned given composition, and the prepared glass raw materials are used to produce the glass according to a known glass manufacturing method. For example, a plurality of compounds are mixed and thoroughly mixed to produce a batch raw material, which is then placed in a platinum crucible or the like for rough melting. The melt obtained by the rough melting is quenched and crushed to produce cullet. The cullet is further placed in a platinum crucible, heated, and remelted to produce molten glass. After further clarification and homogenization, the molten glass is formed and slowly cooled to produce optical glass. The forming and slow cooling of the molten glass can be carried out using known methods.

[0462] It should be noted that as long as the desired glass components can be introduced into the glass and the desired content can be achieved, there is no particular limitation on the compounds used in preparing the batch raw materials. Examples of such compounds include oxides, carbonates, nitrates, hydroxides, fluorides, composite oxides, fluorosilicates, fluoroborates, and the like.

[0463] (Manufacture of glass materials for press molding)

[0464] According to one embodiment of the present invention, there are provided a press-molding glass material formed of the optical glass of this embodiment and a method for producing the same.

[0465] Press-molding of a press-molding glass material can be performed by pressing the heated, softened press-molding glass material using a press-molding mold. Both heating and press-molding can be performed in the atmosphere. A powdered release agent, such as boron nitride, is evenly applied to the surface of the press-molding glass material. During heating and press-molding, this not only reliably prevents fusion between the glass and the mold, but also allows the glass to extend smoothly along the molding surface of the mold. Annealing after press-molding reduces strain within the glass, resulting in a homogeneous optical element blank.

[0466] Examples of press-molding glass materials include glass blocks having a mass equivalent to that of a target press-molded product, such as precision press-molding preforms and glass materials (press-molding glass gobs) for press-molding optical element blanks.

[0467] In addition, press-molded glass raw materials are also called preforms. In addition to raw materials provided for press molding in their original state, they also include raw materials provided for press molding through mechanical processing such as cutting, grinding, and polishing. As cutting methods, there are the following methods: forming a groove in the portion of the surface of the glass plate to be cut using a method called scribing, applying local pressure to the groove portion from the back of the grooved surface, and dividing the glass plate at the groove portion; cutting the glass plate with a cutter; etc. In addition, as grinding methods, spherical surface processing and smoothing processing using a curve generator can be listed. As grinding methods, grinding using abrasive grains such as cerium oxide and zirconium oxide can be listed.

[0468] The glass raw material for press molding of this embodiment is formed of optical glass with excellent mechanical properties, and is therefore not easily damaged during handling and processing. In the past, there was a problem in that damage to the surface of the glass raw material was easily left on the surface of the optical element after press molding, especially on the optical functional surface. The glass raw material for press molding of this embodiment has excellent mechanical properties and is not easily damaged on the surface of the glass raw material, and can therefore be preferably used as a glass raw material for precision press molding. In addition, even when the pressed product after press molding is subjected to mechanical processing, i.e., grinding or polishing to produce an optical element, it is possible to produce a pressed product that is not easily damaged by mechanical processing.

[0469] (Manufacturing of Optical Element Blanks)

[0470] According to one embodiment of the present invention, an optical element blank formed from the optical glass of this embodiment can be provided. The optical element blank is a glass molded body having a shape that is similar to the shape of the optical element to be manufactured. The optical element blank can be produced by a method such as molding glass into a shape that increases the machining allowance removed when machining into the shape of the optical element to be manufactured. For example, the optical element blank can be produced by a method of heating and softening a glass raw material for press molding and press molding (reheat pressing method), or by a method of supplying a molten glass block to a press molding mold and press molding using a known method (direct pressing method).

[0471] (Manufacturing of optical components)

[0472] Known methods can be applied to produce optical elements using the optical glass of this embodiment. For example, the above-mentioned optical element blank can be used for production. In addition, for example, in the production of the above-mentioned optical glass, a glass raw material formed by the optical glass of the present invention is produced by flowing molten glass into a mold and forming it into a plate shape. The obtained glass raw material is appropriately cut, ground, and polished to produce cut pieces of a size and shape suitable for press molding. The cut pieces are heated and softened, and press molded (reheat pressed) by a known method to produce an optical element blank of a shape similar to that of the optical element. The optical element can be produced by a method including a process of processing the optical element blank. As processing, cutting, cutting, rough grinding, fine grinding, grinding, etc. can be exemplified. When performing such processing, by using the above-mentioned glass, breakage can be reduced, and high-quality optical elements can be stably supplied.

[0473] Examples of optical element types include spherical lenses, aspherical lenses, prisms, and diffraction gratings. Examples of lens shapes include biconvex lenses, plano-convex lenses, biconcave lenses, plano-concave lenses, convex meniscus lenses, and concave meniscus lenses. The optically functional surfaces of optical elements may also be coated with anti-reflection films, total reflection films, and the like, depending on their intended use.

[0474] The optical element of this embodiment is formed from optical glass with excellent mechanical properties and is therefore less susceptible to damage during handling and processing. This is particularly true when the optical element is being fixed. For example, during lens centering, even when the lens surface is clamped from both sides, it is not susceptible to damage.

[0475] Example

[0476] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the embodiments shown in the Examples.

[0477] (Example 1)

[0478] Glass samples having the glass compositions shown in Tables 1(1) to (8), 2(1) to (8), 3(1) to (9), 4(1) to (8), 5(1) to (8), 6(1) to (8), 7(1) to (8), 8(1) to (8) and 9(1) to (8) were prepared by the following steps, and various evaluations were performed.

[0479] [Manufacturing of optical glass]

[0480] First, oxides, fluorides, hydroxides, carbonates, nitrates, composite oxides, fluorosilicates, fluoroborates, etc. corresponding to the constituent components of the glass are prepared as raw materials, and the raw materials are weighed and blended in such a manner that the glass composition of the optical glass obtained becomes the composition shown in Table 1 (1) to (8), and the raw materials are thoroughly mixed. The blended raw materials (batch raw materials) thus obtained are placed in a platinum crucible and heated at 1150-1250°C for 1.5-3 hours to form molten glass. The molten glass is then stirred to homogenize and clarified, and then cast into a mold preheated to an appropriate temperature. The cast glass is heat-treated at a temperature near the glass transition temperature Tg for 30 minutes and then naturally cooled to room temperature in a furnace to obtain a glass sample.

[0481] In Table 1 (1) to (8), the content of glass components not shown is 0.00% cation %. For example, in any glass sample, Rb + 、Cs + And Ge 4+ The content of each is 0.00 cation %.

[0482] [Ratio of the number of anions to the number of cations]

[0483] The ratio of the number of anions to the number of cations (anion number / cation number) is the molar ratio of the total number of anions to the total number of cations and can be calculated based on the composition. Specifically, the sum of the positive charges of each cation when the total number of cations is set to 100 (an arbitrary constant) is calculated, and then the negative charge of the anions that form the same number and the molar percentage of anions are combined to calculate the total number of anions when the total number of cations is set to 100. Based on this calculated value, the ratio of the number of anions to the number of cations (anion number / cation number) is calculated.

[0484] [Measurement of optical properties]

[0485] The obtained glass sample was further annealed near the glass transition temperature Tg for about 30 minutes to about 2 hours, and then cooled to room temperature in a furnace at a cooling rate of -30°C / hour to obtain an annealed sample. The refractive index, Abbe number νd, relative partial dispersion Pg,F, ΔPg,F, specific gravity, glass transition temperature Tg, liquidus temperature LT, λ80, λ70, λ5, ΔT360, and ΔT375 of the obtained annealed sample were measured. The results are shown in Tables 2(1) to (8).

[0486] (i) Refractive index nd, ng, nF, nC, Abbe number νd and relative partial dispersion Pg,F

[0487] The refractive index of the annealed sample was measured at the 12 wavelengths shown in Table A in accordance with Japanese Industrial Standard (JIS) JIS B 7071-1 Optical Glass - Determination of Refractive Index - Part 1: Minimum Deviation Angle Method.

[0488] Next, the refractive indices of each ray obtained through measurement were substituted into the Schott dispersion equation specified in Appendix B of JIS B7071-1, Optical Glass - Determination of Refractive Index - Part 1: Minimum Deviation Angle Method, and the constants of the Schott dispersion equation were determined using the least squares method. The Abbe number νd and the relative partial dispersion Pg,F were then calculated using the Schott dispersion equation with the determined constants.

[0489]

[0490] Schott dispersion type: n 2 =a0+a1λ 2 +a2λ -2 +a3λ -4 +a4λ -6 +a5λ -8

[0491] Where n is the refractive index, λ is the wavelength (μm), and a0, a1, a2, a3, a4, and a5 are constants.

[0492] It should be noted that the refractive index nd refers to the refractive index at a wavelength of 587.56 nm.

[0493] The Abbe number νd is expressed as follows using the refractive indices nd, nF, and nC of d-rays, F-rays, and C-rays, respectively.

[0494] νd=(nd-1) / (nF-nC)

[0495] The relative partial dispersion Pg,F is expressed as follows using the refractive indices ng, nF, and nC of g-rays, F-rays, and C-rays, respectively.

[0496] Pg,F=(ng-nF) / (nF-nC)

[0497] (ii) ΔPg,F

[0498] In a plane where the horizontal axis represents the Abbe number νd and the vertical axis represents the relative partial dispersion Pg,F, the normal line Pg,F(0) is expressed by the following equation.

[0499] Pg,F(0)=0.6483-(0.001802×νd)

[0500] The deviation ΔPg,F of the relative partial dispersion Pg,F from the normal line is calculated based on the following formula.

[0501] ΔPg,F=Pg,F-Pg,F(0)

[0502] (iii) Specific gravity

[0503] The specific gravity was measured by the Archimedes method.

[0504] (iv) Glass transition temperature Tg

[0505] The glass transition temperature Tg was measured using a differential scanning calorimeter (DSC3300SA) manufactured by NETZSCH JAPAN CO., LTD. at a heating rate of 10° C. / min.

[0506] (v) Liquidus temperature LT

[0507] The glass was placed in a furnace heated to a given temperature and held there for approximately two hours. After cooling, the interior of the glass was observed using an optical microscope at 40-100x magnification, and the liquidus temperature was determined based on the presence or absence of crystallization.

[0508] (vi) λ80, λ70, λ5

[0509] The annealed sample was processed to a thickness of 10 mm with parallel, optically polished surfaces, and its spectral transmittance was measured over a wavelength range of 280 nm to 700 nm. The intensity of light perpendicularly incident on one optically polished surface was defined as intensity A, and the intensity of light emitted from the other surface was defined as intensity B. The spectral transmittance (B / A) was calculated. The wavelength at which the spectral transmittance reached 80% was designated as λ80, the wavelength at which the spectral transmittance reached 70% as λ70, and the wavelength at which the spectral transmittance reached 5% as λ5. It should be noted that the spectral transmittance also includes light reflection losses from the sample surface.

[0510] (vii) ΔT360, ΔT375

[0511] The annealed sample was processed to a thickness of 10.0 mm ± 0.1 mm with parallel, optically polished flat surfaces. External transmittance at wavelengths of 700 nm and 360 nm was measured. The difference between the external transmittance at a wavelength of 700 nm (T700) and the external transmittance at a wavelength of 360 nm (T360) was calculated as ΔT360.

[0512] Similarly, the annealed sample was processed to a thickness of 10.0 mm ± 0.1 mm with parallel, optically polished flat surfaces. External transmittance at wavelengths of 700 nm and 375 nm was measured. The difference between the external transmittance at a wavelength of 700 nm (T700) and the external transmittance at a wavelength of 375 nm (T375) was calculated as ΔT375.

[0513] External transmittance is defined as the ratio of the transmitted light intensity to the incident light intensity when light is incident along the thickness of the glass sample [transmitted light intensity / incident light intensity × 100]. It should be noted that external transmittance also includes light reflection losses at the sample surface.

[0514] [Chemical durability acid resistance Da]

[0515] The obtained glass sample was made into powdered glass (particle size 425-600 μm). A mass of this powdered glass equivalent to its specific gravity was placed in a platinum cage and immersed in a quartz glass round-bottom flask containing 80 mL of a 0.01 mol / L nitric acid aqueous solution for 60 minutes. The results were evaluated by classifying the mass reduction rate (%) into the grades shown in Table B. The results are shown in Tables 2 (1) to (8).

[0516]

[0517] [Chemical durability and water resistance Dw]

[0518] The obtained glass sample was made into powdered glass (particle size 425-600 μm). A mass of this powdered glass equivalent to its specific gravity was placed in a platinum cage, immersed in 80 mL of pure water (pH = 6.5-7.5) in a quartz glass round-bottom flask, and treated in a boiling water bath for 60 minutes. The mass reduction rate (%) was classified into the grades shown in Table C and evaluated. The results are shown in Tables 2 (1) to (8).

[0519]

[0520] [Mechanical properties Knoop hardness Hk]

[0521] The obtained glass samples were processed to have parallel, optically polished surfaces with a thickness of 2 mm to 20 mm. The Knoop hardness Hk was measured according to the Japan Optical Glass Industry Association standard JOGIS-09. Specifically, a knob was pressed into the processed glass sample, and the Knoop hardness Hk was measured based on the size of the indentation. The results are shown in Tables 2(1) to (8).

[0522]

[0523]

[0524]

[0525]

[0526]

[0527]

[0528]

[0529]

[0530]

[0531]

[0532]

[0533]

[0534]

[0535]

[0536]

[0537]

[0538]

[0539]

[0540]

[0541]

[0542]

[0543]

[0544]

[0545]

[0546]

[0547]

[0548]

[0549]

[0550]

[0551]

[0552]

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[0594] (Example 2)

[0595] Using each optical glass produced in Example 1, lens blanks were produced by a known method, and the lens blanks were processed by a known method such as grinding to produce various lenses.

[0596] The optical lenses produced include various lenses such as biconvex lenses, biconcave lenses, plano-convex lenses, plano-concave lenses, concave meniscus lenses, and convex meniscus lenses.

[0597] By combining the various lenses produced above with lenses made of glass with a smaller Abbe number than the lens, such as flint glass, it is possible to effectively compensate for high-order chromatic aberration in the near-ultraviolet to visible light regions.

[0598] It should be understood that the embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present invention is defined by the claims, not by the foregoing description, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0599] For example, the optical glass of one embodiment of the present invention can be produced by adjusting the composition described in the specification with respect to the glass composition exemplified above.

[0600] Furthermore, it is of course possible to arbitrarily combine two or more items described as examples or preferred ranges in the specification.

Claims

1. An optical glass, wherein: B 3+ The content of cations is greater than 0% and less than 50.00%. F - The content of anions is greater than 0%, The glass transition temperature Tg is below 625°C. Knoop hardness is above 450. ΔPg,F is -0.0025 or more, The Abbe number νd is 37.5 or more, The refractive index nd and the Abbe number νd satisfy the following formula: nd≥-0.0081×νd+2.1181.

2. The optical glass according to claim 1, wherein Si 4+ The content of cationic ions is less than 30%, Li + The content of cationic ions is less than 30%, Na + The content of cationic ions is less than 30%, K + The content of cationic ions is less than 30%, Mg 2+ The content of cationic ions is less than 25%, Ca 2+ The content of cationic ions is less than 25%, Sr 2+ The content of cationic ions is less than 25%, Ba 2+ The content of cationic ions is less than 25%, Zn 2+ The content of cationic ions is less than 25%, La 3+ The content of cationic ions is less than 50%, Y 3+ The content of cationic ions is less than 50%, Gd 3+ The content of cationic ions is less than 30%, Zr 4+ The content of cationic ions is less than 15%, Ta 5+ The content of cationic ions is less than 15%, Ti 4+ The content of cationic ions is less than 15%, Nb 5+ The content of cationic ions is less than 15%, W 6+ The content of cationic ions is less than 15%, Bi 3+ The content of cationic ions is less than 15%, Ge 4+ The content of cationic ions is less than 5%, Li + 、Na + , K + , Rb + 、Cs + Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ The total content [Li + +Na + +K + +Rb + +Cs + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ] is greater than 0 cation % and less than 50 cation %, La 3+ 、Gd 3+ and Y 3+ The total content [La 3+ +Gd 3+ +Y 3+ ] is greater than 0 cation % and less than 70 cation %, La 3+ 、Gd 3+ 、Y 3+ 、Li + 、Na + , K + , Rb + 、Cs + Mg 2+ , Ca 2+ 、Sr 2+ And Ba 2+ Total content relative to Si 4+ 、B 3+ 、P 5+ 、Ti 4+ 、Nb 5+ 、W 6+ 、Bi 3+ 、Zr 4+ and Ta 5+ The total cation content ratio [(La 3+ +Gd 3+ +Y 3+ +Li + +Na + +K + +Rb + +Cs + +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ ) / (Si 4+ +B 3+ +P 5+ +Ti 4+ +Nb 5+ +W 6+ +Bi 3+ +Zr 4+ +Ta 5+ )] is above 0.

50.

3. The optical glass according to claim 1, wherein the acid resistance Da is level 4 or higher. The optical glass according to claim 1 , wherein the glass transition temperature Tg is 540° C. or lower.

5. The optical glass according to claim 1, wherein The content of Sb ions is 1.0 mass ppm or more in terms of added proportion.

6. The optical glass according to claim 1, wherein: When the thickness is set to 10.0 mm±0.1 mm, the difference between the external transmittance at a wavelength of 700 nm and the external transmittance at a wavelength of 360 nm is 10% or less.

7. The optical glass according to claim 1, wherein: When the thickness is set to 10.0 mm±0.1 mm, the difference between the external transmittance at a wavelength of 700 nm and the external transmittance at a wavelength of 375 nm is 7.5% or less. 8 . A press-molding glass material, comprising the optical glass according to claim 1 .

9. An optical element made of the optical glass according to any one of claims 1 to 7.

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