CN113292242A

CN113292242A - Special dispersion optical glass

Info

Publication number: CN113292242A
Application number: CN202110708242.6A
Authority: CN
Inventors: 匡波
Original assignee: CDGM Glass Co Ltd
Current assignee: CDGM Glass Co Ltd
Priority date: 2021-06-24
Filing date: 2021-06-24
Publication date: 2021-08-24
Anticipated expiration: 2041-06-24
Also published as: CN113292242B; JP2024521535A; WO2022267751A1

Abstract

The invention provides special dispersion optical glass, which comprises the following components in percentage by weight: SiO 2₂：23～45％；Nb₂O₅：20～40％；ZrO₂：2～14％；RO：1～25％；Rn₂O：0～25％；Ln₂O₃: 0 to 20% of SiO₂/Nb₂O₅0.65 to 2.0, the RO is the total content of BaO, SrO, CaO and MgO, Rn₂O is Li₂O、Na₂O、K₂Total content of O, Ln₂O₃Is La₂O₃、Gd₂O₃、Y₂O₃、Yb₂O₃The total content of (a). Through reasonable component design, the special dispersion optical glass obtained by the invention has lower P_g,FValue sum Δ P_g,FIdentity of valueThe chemical stability is excellent.

Description

Special dispersion optical glass

Technical Field

The invention relates to an optical glass, in particular to a special dispersion optical glass, and a glass prefabricated member, an optical element and an optical instrument which are made of the special dispersion optical glass.

Background

The optical glass is an important component of photoelectric products, and in recent years, with the rapid development of photoelectric products such as smart phones, single-lens reflex cameras, monitoring security and the like, higher requirements are put forward on the performance of the optical glass. For example, it is desirable in optical design for optical glasses to have the property of eliminating or possibly eliminating residual chromatic aberration of the secondary spectrum, which requires optical glasses having a low relative partial dispersion (P)_g,F) And relative partial dispersion deviation value (Δ P)_g,F). On the other hand, optical glass may be exposed to acids, alkalis, water and the like during processing, cleaning or use, if not superiorThe chemical stability of the glass can shorten the service life of the optical glass.

Thus, develop a P_g,FValue sum Δ P_g,FOptical glass having a low value and excellent chemical stability has become a new problem for researchers.

Disclosure of Invention

The invention aims to provide a P_g,FValue sum Δ P_g,FAn optical glass having a low value and excellent chemical stability.

The technical scheme adopted by the invention for solving the technical problem is as follows:

(1) the special dispersion optical glass comprises the following components in percentage by weight: SiO 2₂：23～45％；Nb₂O₅：20～40％；ZrO₂：2～14％；RO：1～25％；Rn₂O：0～25％；Ln₂O₃: 0 to 20% of SiO₂/Nb₂O₅0.65 to 2.0, the RO is the total content of BaO, SrO, CaO and MgO, Rn₂O is Li₂O、Na₂O、K₂Total content of O, Ln₂O₃Is La₂O₃、Gd₂O₃、Y₂O₃、Yb₂O₃The total content of (a).

(2) The special dispersion optical glass comprises the following components in percentage by weight: SiO 2₂：23～45％；Nb₂O₅：20～40％；ZrO₂：2～14％；RO：1～25％；Rn₂O：0～25％；Ln₂O₃: 0 to 20%, RO is the total content of BaO, SrO, CaO and MgO, Rn₂O is Li₂O、Na₂O、K₂Total content of O, Ln₂O₃Is La₂O₃、Gd₂O₃、Y₂O₃、Yb₂O₃The total content of (a).

(3) The special dispersion optical glass according to any one of (1) or (2), which further comprises, in terms of weight percent: ZnO: 0 to 10 percent; and/or WO₃: 0 to 5 percent; and/or B₂O₃: 0-8%; and/or TiO₂: 0 to 5 percent; and/or Al₂O₃: 0 to 5 percent; and/or Ta₂O₅: 0 to 5 percent; and/or a clarifying agent: 0-1% of a clarifying agent Sb₂O₃、SnO、SnO₂、CeO₂One or more of (a).

(4) Special dispersion optical glass, which contains SiO in its composition₂、Nb₂O₅And an alkaline earth metal oxide, the composition of which is expressed in weight percent, wherein SiO₂/Nb₂O₅0.65 to 2.0, the refractive index n of the special dispersion optical glass_d1.68 to 1.82, Abbe number v_d31 to 40, P_g,FA value of 0.7000 or less,. DELTA.P_g,FThe value is 0 or less.

(5) The special dispersion optical glass according to (4), which comprises the following components in percentage by weight: SiO 2₂: 23-45%; and/or Nb₂O₅: 20-40%; and/or ZrO₂: 2-14%; and/or RO: 1-25%; and/or Rn₂O: 0 to 25 percent; and/or Ln₂O₃: 0 to 20 percent; and/or ZnO: 0 to 10 percent; and/or WO₃: 0 to 5 percent; and/or B₂O₃: 0-8%; and/or TiO₂: 0 to 5 percent; and/or Al₂O₃: 0 to 5 percent; and/or Ta₂O₅: 0 to 5 percent; and/or a clarifying agent: 0 to 1%, RO is the total content of BaO, SrO, CaO and MgO, Rn₂O is Li₂O、Na₂O、K₂Total content of O, Ln₂O₃Is La₂O₃、Gd₂O₃、Y₂O₃、Yb₂O₃In total, the clarifying agent is Sb₂O₃、SnO、SnO₂、CeO₂One or more of (a).

(6) Special dispersion optical glass, the composition of which is expressed in weight percentage by SiO₂：23～45％；Nb₂O₅：20～40％；ZrO₂：2～14％；RO：1～25％；Rn₂O：0～25％；Ln₂O₃：0～20％；ZnO：0～10％；WO₃：0～5％；B₂O₃：0～8％；TiO₂：0～5％；Al₂O₃：0～5％；Ta₂O₅: 0 to 5 percent; a clarifying agent: 0 to 1%, wherein RO is the total content of BaO, SrO, CaO and MgO, Rn₂O is Li₂O、Na₂O、K₂Total content of O, Ln₂O₃Is La₂O₃、Gd₂O₃、Y₂O₃、Yb₂O₃In total, the clarifying agent is Sb₂O₃、SnO、SnO₂、CeO₂One or more of (a).

(7) The special dispersion optical glass according to any one of (1) to (6), which comprises the following components in percentage by weight: SiO 2₂/Nb₂O₅0.75 to 1.8, preferably SiO₂/Nb₂O₅0.8 to 1.5, more preferably SiO₂/Nb₂O₅0.9 to 1.3.

(8) The special dispersion optical glass according to any one of (1) to (7), which comprises the following components in percentage by weight: nb₂O₅/(BaO+La₂O₃) 0.8 to 8.0, preferably Nb₂O₅/(BaO+La₂O₃) 1.0 to 6.0, more preferably Nb₂O₅/(BaO+La₂O₃) 1.2 to 4.0, and further preferably Nb₂O₅/(BaO+La₂O₃) 1.5 to 3.0.

(9) The special dispersion optical glass according to any one of (1) to (8), which comprises the following components in percentage by weight: ZnO/(BaO + La)₂O₃) Is 2.0 or less, preferably ZnO/(BaO + La)₂O₃) 0.05 to 1.5, and more preferably ZnO/(BaO + La)₂O₃) 0.08 to 1.0, and further preferably ZnO/(BaO + La)₂O₃) 0.1 to 0.5.

(10) The special dispersion optical glass according to any one of (1) to (9), which comprises the following components in percentage by weight: (CaO + Na)₂O)/BaO is 0.02 to 8.0, preferably (CaO + Na)₂O)/BaO is 0.05 to 5.0, and (CaO + Na) is more preferable₂O)/BaO is 0.1 to 3.0, and (CaO + Na) is more preferable₂O)/BaO is 0.2 to 1.0.

(11) The special dispersion optical glass according to any one of (1) to (10), which comprises the following components in percentage by weight: BaO/(Na)₂O+Nb₂O₅) 0.05 to 0.8, preferably BaO/(Na)₂O+Nb₂O₅) 0.1 to 0.6, more preferably BaO/(Na)₂O+Nb₂O₅) 0.15 to 0.5, and further preferably BaO/(Na)₂O+Nb₂O₅) 0.2 to 0.4.

(12) The special dispersion optical glass according to any one of (1) to (11), which comprises the following components in percentage by weight: li₂O/Rn₂O is 0.3 to 1.0, and Li is preferable₂O/Rn₂O is 0.4 to 0.9, and Li is more preferable₂O/Rn₂O is 0.45 to 0.8, and Li is more preferable₂O/Rn₂O is 0.5 to 0.75.

(13) The special dispersion optical glass according to any one of (1) to (12), which comprises the following components in percentage by weight: SiO 2₂/(BaO + ZnO) is 1.0 to 20.0, and SiO is preferable₂/(BaO + ZnO) is 1.5 to 15.0, and SiO is more preferable₂/(BaO + ZnO) is 2.0 to 10.0, and SiO is more preferable₂and/(BaO + ZnO) is 2.5 to 5.0.

(14) The special dispersion optical glass according to any one of (1) to (13), which comprises the following components in percentage by weight: b is₂O₃/SiO₂Is 0.3 or less, preferably B₂O₃/SiO₂Is 0.2 or less, more preferably B₂O₃/SiO₂Is 0.15 or less, and B is more preferably B₂O₃/SiO₂Is 0.1 or less.

(15) The special dispersion optical glass according to any one of (1) to (14), which comprises the following components in percentage by weight: SiO 2₂: 28-42%, preferably SiO₂: 31-40%; and/or Nb₂O₅: 22 to 37%, preferably Nb₂O₅: 26 to 33 percent; and/or ZrO₂: 3 to 12%, preferably ZrO₂：5～10％；And/or RO: 3-20%, preferably RO: 6-15%; and/or Rn₂O: 1 to 20%, preferably Rn₂O: 2-15%; and/or Ln₂O₃: 1 to 15%, preferably Ln₂O₃: 2-10%; and/or ZnO: 0.1-8%, preferably ZnO: 0.5-6%; and/or WO₃: 0 to 3%, preferably WO₃: 0-2%; and/or B₂O₃: 0 to 4%, preferably B₂O₃: 0-2%; and/or TiO₂: 0 to 3%, preferably TiO₂: 0-2%; and/or Al₂O₃: 0 to 2%, preferably Al₂O₃: 0 to 1 percent; and/or Ta₂O₅: 0 to 2%, preferably Ta₂O₅: 0 to 1 percent; and/or a clarifying agent: 0 to 0.5%, RO is the total content of BaO, SrO, CaO and MgO, Rn₂O is Li₂O、Na₂O、K₂Total content of O, Ln₂O₃Is La₂O₃、Gd₂O₃、Y₂O₃、Yb₂O₃In total content of Sb as a clarifying agent₂O₃、SnO、SnO₂、CeO₂One or more of (a).

(16) The special dispersion optical glass according to any one of (1) to (15), which comprises the following components in percentage by weight: BaO: 2-18%, preferably BaO: 4-15%, more preferably BaO: 5-12%; and/or CaO: 0-18%, preferably CaO: 0 to 16.5%, more preferably CaO: 0-8%; and/or SrO: 0 to 8%, preferably SrO: 0 to 5%, more preferably SrO: 0-2%; and/or MgO: 0-8%, preferably MgO: 0 to 5%, more preferably MgO: 0-2%; and/or Li₂O: 1 to 12%, preferably Li₂O: 1 to 10%, more preferably Li₂O: 1-9%; and/or Na₂O: 0 to 10%, preferably Na₂O: 0.5 to 8%, more preferably Na₂O: 1-6%; and/or K₂O: 0 to 8%, preferably K₂O: 0 to 5%, more preferably K₂O: 0 to 4 percent; and/or La₂O₃: 0 to 14%, preferably La₂O₃: 2 to 12%, more preferably La₂O₃: 4-10%; and/or Gd₂O₃: 0 to 10%, preferably Gd₂O₃: 0 to 5%, more preferably Gd₂O₃: 0 to 3 percent; and/or Y₂O₃: 0 to 10%, preferably Y₂O₃: 0 to 5%, more preferably Y₂O₃: 0 to 3 percent; and/or Yb₂O₃: 0 to 10%, preferably Yb₂O₃: 0 to 5%, more preferably Yb₂O₃：0～3％。

(17) The special dispersion optical glass according to any one of (1) to (16), wherein B is not contained in the composition₂O₃(ii) a And/or does not contain TiO₂(ii) a And/or does not contain WO₃(ii) a And/or does not contain Ta₂O₅(ii) a And/or does not contain SrO; and/or does not contain MgO; and/or does not contain CaO; and/or does not contain Gd₂O₃(ii) a And/or does not contain Y₂O₃。

(18) The special dispersion optical glass according to any one of (1) to (17) having a refractive index n_d1.68 to 1.82, preferably 1.70 to 1.80, more preferably 1.71 to 1.79, and still more preferably 1.73 to 1.77; and/or Abbe number v_d31 to 40, preferably 32 to 38, and more preferably 33 to 37.

(19) The special dispersion optical glass as described in any one of (1) to (18) above_g,FA value of 0.7000 or less, preferably 0.6500 or less, more preferably 0.6000 or less; and/or Δ P_g,FThe value is 0 or less, preferably-0.0010 or less, more preferably-0.0020 or less, and still more preferably-0.0030 or less.

(20) The special dispersion optical glass according to any one of (1) to (19) having a density ρ of 3.80g/cm³Hereinafter, it is preferably 3.70g/cm³Hereinafter, more preferably 3.60g/cm³The following; and/or coefficient of thermal expansion alpha_-30/70℃Is 100 x 10^-7Preferably 90X 10 or less,/K^-7A value of not more than 85X 10^-7below/K; and/or transition temperature T_gIs 600 ℃ or lower, preferably 590 ℃ or lower, more preferably 580 ℃ or lower, and further preferably 570 ℃ or lower; and/or lambda₈₀Less than or equal to 410nm, preferably lambda₈₀Less than or equal to 400nm, more preferably lambda₈₀Less than or equal to 395 nm; and/or lambda₅Less than or equal to 340nm, preferably lambda₅Less than or equal to 335nm, more preferably lambda₅Less than or equal to 330 nm; and/or stability against water action D_WIs 2 or more, preferably 1; and/or stability against acid action D_AIs 2 or more, preferably 1; and/or Knoop hardness H_KIs 520X 10⁷Pa or more, preferably 540X 10⁷Pa or more, more preferably 550X 10⁷Pa or more, more preferably 570X 10⁷Pa or above.

(21) A glass preform made of the special dispersion optical glass according to any one of (1) to (20).

(22) An optical element produced from the special dispersion optical glass according to any one of (1) to (20), or the glass preform according to (21).

(23) An optical device comprising the special dispersion optical glass according to any one of (1) to (20) or the optical element according to (22).

The invention has the beneficial effects that: through reasonable component design, the special dispersion optical glass obtained by the invention has lower P_g,FValue sum Δ P_g,FThe chemical stability is excellent at the same time.

Detailed Description

The following describes in detail embodiments of the special dispersion optical glass of the present invention, but the present invention is not limited to the embodiments described below, and can be implemented by making appropriate changes within the scope of the object of the present invention. Although the description of the overlapping portions may be omitted as appropriate, the invention is not limited thereto, and the special dispersion optical glass of the present invention may be simply referred to as an optical glass or a glass in the following description.

[ Special Dispersion optical glass ]

The ranges of the respective components (ingredients) of the special dispersion optical glass of the present invention are explained below. In the present invention, the contents and total contents of the respective components are all expressed in weight percent (wt%), that is, the contents and total contents of the respective components are expressed in weight percent with respect to the total amount of the glass substance converted into the composition of oxides, if not specifically stated. Here, the "composition converted to oxides" means that when oxides, complex salts, hydroxides, and the like used as raw materials of the optical glass composition component of the present invention are decomposed in the melt and converted to oxides, the total amount of the oxides is 100%.

Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. As used herein, "and/or" is inclusive, e.g., "A and/or B," and means A alone, B alone, or both A and B.

< essential Components and optional Components >

SiO₂Has the effects of improving the chemical stability of glass, maintaining the viscosity suitable for the formation of molten glass and reducing the corrosion to refractory materials or platinum ware, and the invention contains more than 23 percent of SiO₂To obtain the above effects, SiO is preferable₂Is 28% or more, and SiO is more preferable₂The content of (B) is more than 31%. If SiO₂Too high content of (b) increases the difficulty of melting the glass, while being disadvantageous in lowering the transition temperature of the glass. Thus, SiO in the present invention₂The upper limit of the content of (B) is 45%, preferably 42%, more preferably 40%.

Nb₂O₅Is a high-refractive high-dispersion component, can improve the refractive index and devitrification resistance of the glass, and has the function of reducing the relative partial dispersion P of the glass_g,FAnd relative partial dispersion deviation value Δ P_g,FBy containing 20% or more of Nb₂O₅To obtain the above effects, Nb is preferable₂O₅The lower limit of (B) is 22%, and the more preferable lower limit is 26%. If Nb₂O₅More than 40%, the thermal and chemical stability of the glass is lowered and the light transmittance is lowered, so that Nb in the present invention is₂O₅The upper limit of the content of (B) is 40%, preferably 37%, more preferably 33%。

The inventors have discovered, through extensive experimental studies, that in some embodiments of the invention, SiO is controlled₂Content of (2) and Nb₂O₅Ratio between contents of (A) SiO₂/Nb₂O₅Within the range of 0.65 to 2.0, the optical glass of the present invention can obtain desired optical constants and reduce the P value of the glass_g,FValue sum Δ P_g,FAnd improve the chemical stability of the glass. Therefore, SiO is preferable₂/Nb₂O₅0.65 to 2.0, more preferably SiO₂/Nb₂O₅0.75 to 1.8, and more preferably SiO₂/Nb₂O₅0.8 to 1.5, and further preferably SiO₂/Nb₂O₅0.9 to 1.3.

ZrO₂Can improve the refractive index of the glass, adjust the dispersion and reduce the P of the glass_g,FValue sum Δ P_g,FThe alkali resistance of the glass is optimized by containing ZrO in an amount of 2% or more in the present invention₂In order to obtain the above effects, it is preferable to contain 3% or more of ZrO₂More preferably, it contains 5% or more of ZrO₂. If ZrO of₂The content of (b) is more than 14%, the difficulty of melting the glass increases, the melting temperature increases, and inclusions appear in the glass and the light transmittance decreases. Thus, ZrO₂The content of (b) is 14% or less, preferably 12% or less, more preferably 10% or less.

ZnO can adjust the refractive index and dispersion of glass, improve the stability of the glass, and simultaneously ZnO can reduce the high-temperature viscosity and the transition temperature of the glass, so that the glass can be melted at a lower temperature, and the light transmittance of the glass is improved. On the other hand, if the content of ZnO is too high, the difficulty of glass forming increases, and the devitrification resistance becomes poor. Therefore, the content of ZnO is 10% or less, preferably 0.1 to 8%, more preferably 0.5 to 6%.

The alkaline earth metal oxide can adjust the optical constant of the glass and improve the devitrification resistance of the glass, and if the content is too high, the chemical stability of the glass is lowered. Therefore, the total content RO of the alkaline earth metal oxides BaO, SrO, CaO and MgO is 1 to 25%, preferably 3 to 20%, and more preferably 6 to 15%.

BaO in the present invention can improve devitrification resistance and hardness of the glass and reduce the temperature coefficient of refractive index and thermal expansion coefficient of the glass, and in the present invention, the above effects are obtained by containing BaO in an amount of 2% or more, preferably 4% or more, and more preferably 5% or more. On the other hand, by setting the BaO content to 18% or less, it is possible to prevent the decrease in chemical stability due to an excessively high BaO content, and the BaO content is preferably 15% or less, and more preferably 12% or less.

In some embodiments of the invention, SiO is controlled₂SiO is a ratio of the content of (B) to the total content of BaO and ZnO (BaO + ZnO)₂And/or (BaO + ZnO) is within the range of 1.0-20.0, so that the glass forming stability and the light transmittance of the glass can be optimized, and the thermal expansion coefficient of the glass can be reduced. Therefore, SiO is preferable₂/(BaO + ZnO) is 1.0 to 20.0, and SiO is more preferable₂/(BaO + ZnO) of 1.5 to 15.0, and SiO is more preferable₂/(BaO + ZnO) is 2.0 to 10.0, and SiO is more preferable₂and/(BaO + ZnO) is 2.5 to 5.0.

CaO contributes to adjustment of the optical constants of the glass and improvement of the processability of the glass, but when the content of CaO is too large, the optical constants of the glass do not meet the requirements, and the devitrification resistance is deteriorated. Therefore, the CaO content is in the range of 0 to 18%, preferably 0 to 16.5%, and more preferably 0 to 8%. In some embodiments, it is further preferred that CaO is absent.

While SrO can adjust the refractive index and dispersion of glass, if the content is too large, the chemical stability of glass is lowered and the cost of glass is rapidly increased. Therefore, the SrO content is 0 to 8%, preferably 0 to 5%, and more preferably 0 to 2%. In some embodiments, it is further preferred that SrO is absent.

MgO is beneficial to reducing the density and melting temperature of the glass, but when the content of MgO is too much, the refractive index of the glass is difficult to meet the design requirement, and the anti-crystallization performance and the stability of the glass are reduced. Therefore, the MgO content is 0 to 8%, preferably 0 to 5%, and more preferably 0 to 2%. In some embodiments, it is further preferred that no MgO be present.

The alkali metal oxide can lower the glass transition temperature and optimize the meltability of the glass, and if the content is too large, the chemical stability and devitrification resistance of the glass are lowered. Thus, the alkali metal oxide Li in the present invention₂O、Na₂O、K₂Total content Rn of O₂O is 25% or less, preferably 1 to 20%, more preferably 2 to 15%.

Li₂O can remarkably improve the meltability of the glass and increase ZrO₂Solubility in glass and lowering of glass transition temperature, adjusting of glass refractive index, but too high content thereof is disadvantageous in acid resistance stability and thermal expansion coefficient of glass. Thus, Li in the present invention₂The content of O is 1 to 12%, preferably 1 to 10%, more preferably 1 to 9%.

Na₂O has the effect of improving the glass melting property and lowering the glass transition temperature, and if the content thereof exceeds 10%, the chemical stability and weather resistance of the glass are lowered. Thus, Na₂The content of O is 0 to 10%, preferably 0.5 to 8%, more preferably 1 to 6%.

In some embodiments of the invention, the composition is prepared by combining CaO and Na₂Total content of O (CaO + Na)₂Ratio between O) and BaO content (CaO + Na)₂The O)/BaO is within the range of 0.02-8.0, the chemical stability of the optical glass can be improved, the density of the glass can be reduced, and the light weight of an optical system can be realized. Therefore, (CaO + Na) is preferable₂O)/BaO is 0.02 to 8.0, and (CaO + Na) is more preferable₂O)/BaO is 0.05 to 5.0. Further, by reacting (CaO + Na)₂The O)/BaO is in the range of 0.1-3.0, and the hardness of the glass can be further optimized. Therefore, (CaO + Na) is more preferable₂O)/BaO is 0.1 to 3.0, and (CaO + Na) is more preferable₂O)/BaO is 0.2 to 1.0.

In some embodiments of the invention, the content of BaO is adjusted to Na₂O and Nb₂O₅Total content of (Na)₂O+Nb₂O₅) Ratio between BaO/(Na)₂O+Nb₂O₅) Within the range of 0.05-0.8, the hardness of the glass can be improved, and the light transmittance of the glass can be optimized. Therefore, BaO/(Na) is preferable₂O+Nb₂O₅) 0.05 to 0.8, more preferably BaO/(Na)₂O+Nb₂O₅) 0.1 to 0.6, and further preferably BaO/(Na)₂O+Nb₂O₅) 0.15 to 0.5, and further preferably BaO/(Na)₂O+Nb₂O₅) 0.2 to 0.4.

K₂O has the effect of improving the thermal stability and the melting property of the glass, but when K is used₂When the content of O exceeds 8%, the devitrification resistance of the glass is lowered. Thus, K₂The upper limit of the content of O is 8%, preferably 5%, more preferably 4%.

The inventors have found through extensive experimental studies that, in some embodiments of the present invention, when Li is present₂O/Rn₂And the O is in the range of 0.3-1.0, so that the devitrification resistance of the glass can be optimized, and the water resistance of the glass is improved. Therefore, Li is preferable₂O/Rn₂O is 0.3 to 1.0, and Li is more preferable₂O/Rn₂O is 0.4 to 0.9. Further, by reacting Li₂O/Rn₂O is in the range of 0.45-0.8, which is beneficial to improving the weather resistance of the glass. Therefore, Li is more preferable₂O/Rn₂O is 0.45 to 0.8, and Li is more preferable₂O/Rn₂O is 0.5 to 0.75.

Ln₂O₃(Ln₂O₃Is La₂O₃、Gd₂O₃、Y₂O₃、Yb₂O₃The total content of (b) can increase the refractive index of the glass, and if the content is more than 20%, the devitrification resistance of the glass is lowered. Thus, Ln₂O₃The content of (b) is 20% or less, preferably 1 to 15%, more preferably 2 to 10%.

La₂O₃Can effectively improve the refractive index of the glass, enhance the chemical stability and the mechanical strength of the glass and simultaneously do not obviously increase the P of the glass_g,FValue sum Δ P_g,FHowever, when the content exceeds 14%, the resistance to devitrification of the glass becomes poor. Thus, La in the glass of the present invention₂O₃The content of (b) is 0 to 14%, preferably 2 to 12%, more preferably 4 to 10%.

As a result of extensive experimental studies by the inventors, it was found that in some embodiments of the present invention, Nb is controlled₂O₅With BaO and La₂O₃Total content of (BaO + La)₂O₃) Ratio between Nb₂O₅/(BaO+La₂O₃) In the range of 0.8 to 8.0, the glass P can be reduced_g,FValue sum Δ P_g,FAnd meanwhile, the thermal expansion coefficient and the secondary compression crystallization resistance of the glass are optimized. Therefore, Nb is preferable₂O₅/(BaO+La₂O₃) 0.8 to 8.0, more preferably Nb₂O₅/(BaO+La₂O₃) 1.0 to 6.0, and more preferably Nb₂O₅/(BaO+La₂O₃) 1.2 to 4.0, and further preferably Nb₂O₅/(BaO+La₂O₃) 1.5 to 3.0.

In some embodiments of the invention, the content of ZnO and BaO and La are controlled₂O₃Total content of (BaO + La)₂O₃) The ratio between ZnO/(BaO + La)₂O₃) When the content is 2.0 or less, the decrease in glass hardness can be prevented. Therefore, ZnO/(BaO + La) is preferable₂O₃) Is 2.0 or less, and ZnO/(BaO + La) is more preferable₂O₃) 0.05 to 1.5. Further, by making ZnO/(BaO + La)₂O₃) In the range of 0.08-1.0, the devitrification resistance and the abrasion degree of the glass can be further optimized, and the thermal expansion coefficient of the glass is prevented from being increased. Therefore, ZnO/(BaO + La) is more preferable₂O₃) 0.08 to 1.0, and further preferably ZnO/(BaO + La)₂O₃) 0.1 to 0.5.

Gd₂O₃While the Gd content has an action of increasing the refractive index, when the content exceeds 10%, the devitrification resistance of the glass tends to be lowered and the transition temperature tends to be increased, so that the Gd in the present invention₂O₃The content of (B) is 10% or less, preferably 0 to 5%, more preferably 0 to 3%. In some embodiments, it is further preferred that no Gd is present₂O₃。

Y₂O₃Can improve the meltability of the glassAnd devitrification resistance, which increases the chemical stability of the glass, but if the content thereof exceeds 10%, the stability and devitrification resistance of the glass are lowered. Thus, Y₂O₃The content of (A) is in the range of 0 to 10%, preferably 0 to 5%, more preferably 0 to 3%, and further preferably Y is not contained₂O₃。

Yb₂O₃The refractive index of the glass can be increased, and if the content exceeds 10%, the stability and devitrification resistance of the glass are lowered. Thus, Yb₂O₃The content of (B) is in the range of 0 to 10%, preferably 0 to 5%, more preferably 0 to 3%, and further preferably not containing Yb₂O₃。

WO₃Can improve the refractive index and mechanical strength of the glass, if WO₃When the content of (B) exceeds 5%, the thermal stability of the glass is lowered, and the transmittance and the devitrification resistance are lowered. Thus, WO₃The upper limit of the content of (B) is 5%, preferably 3%, more preferably 2%. In some embodiments, it is further preferred that WO is absent₃。

B₂O₃The glass of the invention can be used as a glass network forming body and is beneficial to reducing the P of the glass_g,FValue sum Δ P_g,FThe value is obtained. When B is present₂O₃When the content of (b) is more than 8%, the chemical stability of the glass is deteriorated, the high-temperature viscosity of the glass is decreased, and the transmittance and secondary press type devitrification resistance of the glass are deteriorated. Thus, B₂O₃The content of (b) is limited to 8% or less, preferably 4% or less, and more preferably 2% or less. In some embodiments, it is further preferred not to contain B₂O₃。

In some embodiments of the invention, B is₂O₃/SiO₂The crystallization resistance and the chemical stability of the glass can be improved by controlling the content of the glass to be less than 0.3. Therefore, B is preferred₂O₃/SiO₂Is 0.3 or less, and B is more preferably₂O₃/SiO₂Is 0.2 or less. Further, make B₂O₃/SiO₂Below 0.15, the hardness of the glass is advantageously increased. Therefore, B is more preferable₂O₃/SiO₂The content of the organic acid is below 0.15,further preferred is B₂O₃/SiO₂Is 0.1 or less.

TiO₂Has the function of improving the refractive index and dispersion of the glass, and contains TiO in a proper amount to make the glass more stable and reduce the viscosity of the glass₂The presence of (A) will significantly increase the P of the glass_g,FValue sum Δ P_g,FValue, therefore, TiO in the present invention₂The content of (b) is 5% or less, preferably 3% or less, more preferably 2% or less. In some embodiments, it is further preferred that no TiO is present₂。

Al₂O₃The chemical stability of the glass can be improved, but when the content thereof exceeds 5%, the meltability and light transmittance of the glass are deteriorated. Therefore, Al in the present invention₂O₃The content of (B) is 0 to 5%, preferably 0 to 2%, more preferably 0 to 1%. In some embodiments, it is further preferred that Al is absent₂O₃。

Ta₂O₅Has the advantages of improving the refractive index of the glass and reducing the P of the glass_g,FValue sum Δ P_g,FThe glass has the advantages that the devitrification resistance is improved, but if the content of the glass is too high, the chemical stability of the glass is reduced, the surface tension of the glass is increased, and bubbles are difficult to eliminate; on the other hand, Ta is compared with other components₂O₅The price of (2) is very expensive, and the amount of use should be minimized from the practical and cost viewpoints. Thus, Ta in the present invention₂O₅The content of (A) is limited to 0 to 5%, preferably 0 to 2%, more preferably 0 to 1%, and further preferably no Ta is contained₂O₅。

In the invention, 0-1% of Sb is contained₂O₃、SnO、SnO₂、CeO₂One or more components in the glass can be used as a clarifying agent, so that the clarifying effect of the glass can be improved, and the content of the clarifying agent is preferably 0-0.5%. When Sb is present₂O₃At contents exceeding 1%, the glass tends to have a reduced fining ability, and since the strong oxidizing action promotes the corrosion of the platinum or platinum alloy vessel from which the glass is melted and the deterioration of the forming mold, Sb is preferred in the present invention₂O₃Is 0 to 1%, and more preferably0 to 0.5 percent. SnO and SnO₂However, when the content exceeds 1%, the glass tends to be colored more, or when the glass is heated, softened, press-molded or the like and then reformed, Sn becomes a starting point of crystal nucleus formation, and the glass tends to be devitrified. Thus the SnO of the invention₂The content of (b) is preferably 0 to 1%, more preferably 0 to 0.5%; the content of SnO is preferably 0 to 1%, more preferably 0 to 0.5%. CeO (CeO)₂The function and content ratio of (A) and (B) of SnO₂The content is preferably 0 to 1%, more preferably 0 to 0.5%, and further preferably no CeO₂。

< component which should not be contained >

In the glass of the present invention, even when a small amount of oxides of transition metals such as V, Cr, Mn, Fe, Co, Ni, Cu, Ag, and Mo is contained singly or in combination, the glass is colored and absorbs at a specific wavelength in the visible light region, thereby impairing the property of the present invention to improve the effect of visible light transmittance.

In recent years, oxides of Th, Cd, Tl, Os, Be, and Se tend to Be used as harmful chemical substances in a controlled manner, and measures for protecting the environment are required not only in the glass production process but also in the processing process and disposal after commercialization. Therefore, when importance is attached to the influence on the environment, it is preferable that these components are not substantially contained except for inevitable mixing. Thereby, the optical glass becomes practically free from substances contaminating the environment. Therefore, the optical glass of the present invention can be manufactured, processed, and discarded without taking special measures for environmental countermeasures.

In order to achieve environmental friendliness, the optical glass of the present invention preferably does not contain As₂O₃And PbO.

"0%" or "0%" is not contained in the present invention, and means that the compound, molecule, element or the like is not intentionally added to the optical glass of the present invention as a raw material; however, it is within the scope of the present invention that certain impurities or components which are not intentionally added may be present as raw materials and/or equipment for producing the optical glass and may be contained in the final optical glass in small or trace amounts.

The properties of the special dispersion optical glass of the present invention will be described below.

< refractive index and Abbe number >

Refractive index (n) of optical glass_d) And Abbe number (v)_d) The test was carried out according to the method specified in GB/T7962.1-2010.

In some embodiments, the refractive index (n) of the special dispersion optical glass of the present invention_d) The lower limit of (b) is 1.68, preferably 1.70, more preferably 1.71, and still more preferably 1.73. In some embodiments, the refractive index (n) of the optical glass of the present invention_d) The upper limit of (b) is 1.82, preferably 1.80, more preferably 1.79, and still more preferably 1.77.

In some embodiments, the Abbe number (v) of the particular dispersive optical glass of the present invention_d) The lower limit of (3) is 31, the lower limit is preferably 32, and the lower limit is more preferably 33. In some embodiments, the Abbe number (v) of the optical glass of the present invention_d) The upper limit of (2) is 40, preferably 38, and more preferably 37.

< Density >

The density (. rho.) of the optical glass was measured according to the method specified in GB/T7962.20-2010.

In some embodiments, the specially dispersive optical glass of the present invention has a density (. rho.) of 3.80g/cm³Hereinafter, it is preferably 3.70g/cm³Hereinafter, more preferably 3.60g/cm³The following.

< coefficient of thermal expansion >

Coefficient of thermal expansion (alpha) of optical glass_-30/70℃) And testing data at-30-70 ℃ according to a method specified in GB/T7962.16-2010.

In some embodiments, the specific dispersion optical glass of the present invention has a coefficient of thermal expansion (α)_-30/70℃) Is 100 x 10^-7Preferably 90X 10 or less,/K^-7A value of not more than 85X 10^-7and/K is less than or equal to.

< transition temperature >

Transition temperature (T) of optical glass_g) The test was carried out according to the method specified in GB/T7962.16-2010.

In some embodiments, the transition temperature (T) of the special dispersion optical glass of the present invention_g) Is 600 ℃ or lower, preferably 590 ℃ or lower, more preferably 580 ℃ or lower, and still more preferably 570 ℃ or lower.

< degree of coloration >

Coloring degree (. lamda.) for short-wave transmission spectral characteristics of the glass of the present invention₈₀And λ₅) And (4) showing. Lambda [ alpha ]₈₀It refers to the wavelength corresponding to the glass transmittance of 80%. Lambda [ alpha ]₈₀Was measured using a glass having a thickness of 10. + -. 0.1mm with two opposing planes parallel to each other and optically polished, measuring the spectral transmittance in the wavelength region from 280nm to 700nm and showing a wavelength of transmittance of 80%. The spectral transmittance or transmittance is the intensity I of light incident perpendicularly to the surface of the glass_inLight transmitted through the glass and having an intensity I emitted from a plane_outIn the case of light of (1) through (I)_out/I_inThe quantity expressed and also the transmission of the surface reflection losses on the above-mentioned surface of the glass. The higher the refractive index of the glass, the greater the surface reflection loss. Thus, in high refractive index glasses, λ₈₀A small value of (A) means that the glass itself is rarely colored and has a high light transmittance.

In some embodiments, the special dispersion optical glasses of the present invention have a lambda₈₀Less than or equal to 410nm, preferably lambda₈₀Less than or equal to 400nm, more preferably lambda₈₀Less than or equal to 395 nm.

In some embodiments, the special dispersion optical glasses of the present invention have a lambda₅Less than or equal to 340nm, preferably lambda₅Less than or equal to 335nm, more preferably lambda₅Less than or equal to 330 nm.

< stability against Water action >

Stability to Water of optical glass (D)_W) (powder method) the test was carried out according to the method prescribed in GB/T17129.

In some embodiments, the water stability of the special dispersion optical glasses of the present invention (D)_W) Is 2 or more, preferably 1.

< stability against acid Effect >

Stability of acid resistance of optical glasses (D)_A) (powder method) the test was carried out according to the method prescribed in GB/T17129.

In some embodiments, the special dispersion optical glasses of the present invention are stable against acid action (D)_A) Is 2 or more, preferably 1.

< Knoop hardness >

Knoop hardness (H) of optical glass_K) The test was carried out according to the test method specified in GB/T7962.18-2010.

In some embodiments, the Knoop hardness (H) of the special dispersion optical glasses of the present invention_K) Is 520X 10⁷Pa or more, preferably 540X 10⁷Pa or more, more preferably 550X 10⁷Pa or more, more preferably 570X 10⁷Pa or above.

< relative partial dispersion and relative partial dispersion deviation value >

The relative partial dispersion (P) is illustrated by the following equation_g,F) And relative partial dispersion deviation value (Δ P)_g,F) The origin of (1).

The relative partial dispersion for wavelengths x and y is represented by the following formula (1):

P_x,y＝(n_x-n_y)/(n_F-n_C) (1)

the following formula (2) holds for most of the so-called "normal glasses" according to the Abbe number formula (hereinafter, H-K6 and F4 are used as "normal glasses")

P_x,y＝m_x,y·v_d+b_x,y (2)

This linear relationship is P_x,yIs ordinate, v_dExpressed on the abscissa, where m_x,yIs a slope, b_x,yIs the intercept.

All of the peopleIt is known that the correction of the secondary spectrum, i.e. the achromatization of more than two wavelengths, requires at least one glass which does not conform to the above formula (2) (i.e. its P)_x,yValue deviation from Abbe's empirical formula) by Δ P_x,yIndicates that each P is_x,y-v_dThe point being shifted by Δ P with respect to a "normal line" corresponding to the above formula (2)_x,yAmount of such a.DELTA.P of each glass_x,yThe numerical value can be obtained by the following formula (3):

P_x,y＝m_x,y·v_d+b_x,y+ΔP_x,y (3)

thus Δ P_x,yQuantitatively indicating the deviation behavior of the specific dispersion when compared to "normal glass".

Therefore, from the above, relative partial dispersion (P) can be obtained_g,F) And relative partial dispersion deviation value (Δ P)_g,F) Are the following formulas (4) and (5):

P_g,F＝(n_g-n_F)/(n_F-n_C) (4)

ΔP_g,F＝P_g,F-0.6457+0.001703v_d (5)

in some embodiments, the relative partial dispersion (P) of the special dispersion optical glasses of the present invention_g,F) Is 0.7000 or less, preferably 0.6500 or less, and more preferably 0.6000 or less.

In some embodiments, the relative partial dispersion deviation value (Δ P) of the special dispersion optical glass of the present invention_g,F) Is 0 or less, preferably-0.0010 or less, more preferably-0.0020 or less, and still more preferably-0.0030 or less.

< resistance to devitrification >

The method for testing the anti-devitrification performance comprises the following steps: cutting the sample glass into a size of 20 × 20 × 10mm, and placing at a temperature T_gAnd (4) preserving the heat in a muffle furnace at 200-250 ℃ for 15-30 minutes, taking out and cooling, and observing whether crystals exist on the surface and the inside of the glass or opacification occurs. If the glass sample is free from opalescence and crystals, the devitrification resistance of the glass is excellent. The test method is used for characterizing the inventionSecondary compression type devitrification resistance of the glass.

[ method for producing Special Dispersion optical glass ]

The method for manufacturing the special dispersion optical glass comprises the following steps: the glass is produced by adopting conventional raw materials and processes, including but not limited to oxides, hydroxides, carbonates, nitrates, phosphates, metaphosphates and the like as raw materials, after the materials are mixed by a conventional method, the mixed furnace materials are put into a smelting furnace (such as a platinum or platinum alloy crucible) at 1200-1400 ℃ for smelting, and after clarification and homogenization, homogeneous molten glass without bubbles and undissolved substances is obtained, and the molten glass is cast in a mould and annealed. Those skilled in the art can appropriately select the raw materials, the process method and the process parameters according to the actual needs.

Glass preform and optical element

The glass preform can be produced from the produced special dispersion optical glass by means of direct gob casting, grinding, or press molding such as hot press molding. That is, a glass preform can be produced by direct precision gob-molding of molten optical glass into a glass precision preform, or by mechanical processing such as grinding and polishing, or by producing a preform for press molding from optical glass, subjecting the preform to reheat press molding, and then performing polishing processing. It should be noted that the means for producing the glass preform is not limited to the above means.

As described above, the special dispersion optical glass of the present invention is useful for various optical elements and optical designs, and among them, it is particularly preferable to form a preform from the special dispersion optical glass of the present invention, and use the preform to produce optical elements such as lenses and prisms by reheat press molding, precision press molding, and the like.

The glass preform and the optical element of the present invention are each formed of the above-described special dispersion optical glass of the present invention. The glass preform of the present invention has excellent characteristics possessed by the special dispersion optical glass; the optical element of the present invention has excellent characteristics of the special dispersion optical glass, and can provide various optical elements such as lenses and prisms having high optical values.

Examples of the lens include various lenses such as a concave meniscus lens, a convex meniscus lens, a double convex lens, a double concave lens, a plano-convex lens, and a plano-concave lens, each of which has a spherical or aspherical lens surface.

[ optical instruments ]

The optical element formed by the special dispersion optical glass can be used for manufacturing optical instruments such as photographic equipment, camera equipment, projection equipment, display equipment, vehicle-mounted equipment, monitoring equipment and the like.

Examples

< example of optical glass >

In order to further clarify the explanation and explanation of the technical solution of the present invention, the following non-limiting examples are provided.

In this example, optical glasses having compositions shown in tables 1 to 5 were obtained by the above-mentioned method for producing a special dispersion optical glass. The characteristics of each glass were measured by the test method described in the present invention, and the measurement results are shown in tables 1 to 5. In the test of devitrification resistance in tables 1 to 5, according to the above test method, the glass is opaque and has no crystal particles inside it as "A", no opaque and 1 to 10 crystal particles inside it as "B", no opaque and 10 to 20 crystal particles inside it as "C", and the glass is opaque or has densely crystallized particles inside it as "X".

Table 1.

Table 2.

Table 3.

Table 4.

Table 5.

< glass preform example >

Various lenses such as a concave meniscus lens, a convex meniscus lens, a biconvex lens, a biconcave lens, a plano-convex lens and a plano-concave lens, and preforms such as prisms were produced by using glasses obtained from examples 1 to 32 of special dispersion optical glasses by means of polishing or press molding such as hot press molding and precision press molding.

< optical element example >

The preforms obtained from the above glass preform examples were annealed to reduce the internal stress of the glass and to fine-tune the refractive index so that the optical properties such as refractive index reached the desired values.

Next, each preform is ground and polished to produce various lenses such as a concave meniscus lens, a convex meniscus lens, a biconvex lens, a biconcave lens, a plano-convex lens, and a plano-concave lens, and prisms. The surface of the resulting optical element may be coated with an antireflection film.

< optical Instrument example >

The optical element produced by the above-described optical element embodiments can be used, for example, for imaging devices, sensors, microscopes, medical technology, digital projection, communication, optical communication technology/information transmission, optics/illumination in the automotive field, lithography, excimer lasers, wafers, computer chips, and integrated circuits and electronic devices including such circuits and chips, by optical design, by forming an optical component or optical assembly using one or more optical elements.

Claims

1. The special dispersion optical glass is characterized by comprising the following components in percentage by weight: SiO 2₂：23～45％；Nb₂O₅：20～40％；ZrO₂：2～14％；RO：1～25％；Rn₂O：0～25％；Ln₂O₃: 0 to 20% of SiO₂/Nb₂O₅0.65 to 2.0, the RO is the total content of BaO, SrO, CaO and MgO, Rn₂O is Li₂O、Na₂O、K₂Total content of O, Ln₂O₃Is La₂O₃、Gd₂O₃、Y₂O₃、Yb₂O₃The total content of (a).

2. The special dispersion optical glass according to claim 1, wherein the components are expressed in weight percent,further comprising: ZnO: 0 to 10 percent; and/or WO₃: 0 to 5 percent; and/or B₂O₃: 0-8%; and/or TiO₂: 0 to 5 percent; and/or Al₂O₃: 0 to 5 percent; and/or Ta₂O₅: 0 to 5 percent; and/or a clarifying agent: 0-1% of a clarifying agent Sb₂O₃、SnO、SnO₂、CeO₂One or more of (a).

3. Special dispersion optical glass, characterized in that the composition contains SiO₂、Nb₂O₅And an alkaline earth metal oxide, the composition of which is expressed in weight percent, wherein SiO₂/Nb₂O₅0.65 to 2.0, the refractive index n of the special dispersion optical glass_d1.68 to 1.82, Abbe number v_d31 to 40, P_g,FA value of 0.7000 or less,. DELTA.P_g,FThe value is 0 or less.

4. A specific dispersion optical glass according to claim 3, having the composition, expressed in weight percent, comprising: SiO 2₂: 23-45%; and/or Nb₂O₅: 20-40%; and/or ZrO₂: 2-14%; and/or RO: 1-25%; and/or Rn₂O: 0 to 25 percent; and/or Ln₂O₃: 0 to 20 percent; and/or ZnO: 0 to 10 percent; and/or WO₃: 0 to 5 percent; and/or B₂O₃: 0-8%; and/or TiO₂: 0 to 5 percent; and/or Al₂O₃: 0 to 5 percent; and/or Ta₂O₅: 0 to 5 percent; and/or a clarifying agent: 0 to 1%, RO is the total content of BaO, SrO, CaO and MgO, Rn₂O is Li₂O、Na₂O、K₂Total content of O, Ln₂O₃Is La₂O₃、Gd₂O₃、Y₂O₃、Yb₂O₃In total, the clarifying agent is Sb₂O₃、SnO、SnO₂、CeO₂One or more of (a).

5. A special dispersion optical glass according to any one of claims 1 to 4, characterised in that its composition is expressed in weight percent, wherein: SiO 2₂/Nb₂O₅0.75 to 1.8, preferably SiO₂/Nb₂O₅0.8 to 1.5, more preferably SiO₂/Nb₂O₅0.9 to 1.3.

6. A special dispersion optical glass according to any one of claims 1 to 4, characterised in that its composition is expressed in weight percent, wherein: nb₂O₅/(BaO+La₂O₃) 0.8 to 8.0, preferably Nb₂O₅/(BaO+La₂O₃) 1.0 to 6.0, more preferably Nb₂O₅/(BaO+La₂O₃) 1.2 to 4.0, and further preferably Nb₂O₅/(BaO+La₂O₃) 1.5 to 3.0.

7. A special dispersion optical glass according to any one of claims 1 to 4, characterised in that its composition is expressed in weight percent, wherein: ZnO/(BaO + La)₂O₃) Is 2.0 or less, preferably ZnO/(BaO + La)₂O₃) 0.05 to 1.5, and more preferably ZnO/(BaO + La)₂O₃) 0.08 to 1.0, and further preferably ZnO/(BaO + La)₂O₃) 0.1 to 0.5.

8. A special dispersion optical glass according to any one of claims 1 to 4, characterised in that its composition is expressed in weight percent, wherein: (CaO + Na)₂O)/BaO is 0.02 to 8.0, preferably (CaO + Na)₂O)/BaO is 0.05 to 5.0, and (CaO + Na) is more preferable₂O)/BaO is 0.1 to 3.0, and (CaO + Na) is more preferable₂O)/BaO is 0.2 to 1.0.

9. A special dispersion optical glass according to any one of claims 1 to 4, characterised in that its composition is expressed in weight percent, wherein: BaO/(Na)₂O+Nb₂O₅) 0.05 to 0.8, preferably BaO/(Na)₂O+Nb₂O₅) 0.1 to 0.6, more preferably BaO/(Na)₂O+Nb₂O₅) 0.15 to 0.5, and further preferably BaO/(Na)₂O+Nb₂O₅) 0.2 to 0.4.

10. A special dispersion optical glass according to any one of claims 1 to 4, characterised in that its composition is expressed in weight percent, wherein: li₂O/Rn₂O is 0.3 to 1.0, and Li is preferable₂O/Rn₂O is 0.4 to 0.9, and Li is more preferable₂O/Rn₂O is 0.45 to 0.8, and Li is more preferable₂O/Rn₂O is 0.5 to 0.75.

11. A special dispersion optical glass according to any one of claims 1 to 4, characterised in that its composition is expressed in weight percent, wherein: SiO 2₂/(BaO + ZnO) is 1.0 to 20.0, and SiO is preferable₂/(BaO + ZnO) is 1.5 to 15.0, and SiO is more preferable₂/(BaO + ZnO) is 2.0 to 10.0, and SiO is more preferable₂and/(BaO + ZnO) is 2.5 to 5.0.

12. A special dispersion optical glass according to any one of claims 1 to 4, characterised in that its composition is expressed in weight percent, wherein: b is₂O₃/SiO₂Is 0.3 or less, preferably B₂O₃/SiO₂Is 0.2 or less, more preferably B₂O₃/SiO₂Is 0.15 or less, and B is more preferably B₂O₃/SiO₂Is 0.1 or less.

13. A special dispersion optical glass according to any one of claims 1 to 4, characterized in that its composition, expressed in weight percent, comprises: SiO 2₂: 28-42%, preferably SiO₂: 31-40%; and/or Nb₂O₅: 22 to 37%, preferably Nb₂O₅: 26 to 33 percent; and/or ZrO₂: 3 to 12%, preferably ZrO₂: 5-10%; and/or RO: 3-20%, preferably RO: 6-15%;and/or Rn₂O: 1 to 20%, preferably Rn₂O: 2-15%; and/or Ln₂O₃: 1 to 15%, preferably Ln₂O₃: 2-10%; and/or ZnO: 0.1-8%, preferably ZnO: 0.5-6%; and/or WO₃: 0 to 3%, preferably WO₃: 0-2%; and/or B₂O₃: 0 to 4%, preferably B₂O₃: 0-2%; and/or TiO₂: 0 to 3%, preferably TiO₂: 0-2%; and/or Al₂O₃: 0 to 2%, preferably Al₂O₃: 0 to 1 percent; and/or Ta₂O₅: 0 to 2%, preferably Ta₂O₅: 0 to 1 percent; and/or a clarifying agent: 0 to 0.5%, RO is the total content of BaO, SrO, CaO and MgO, Rn₂O is Li₂O、Na₂O、K₂Total content of O, Ln₂O₃Is La₂O₃、Gd₂O₃、Y₂O₃、Yb₂O₃In total content of Sb as a clarifying agent₂O₃、SnO、SnO₂、CeO₂One or more of (a).

14. A special dispersion optical glass according to any one of claims 1 to 4, characterized in that its composition, expressed in weight percent, comprises: BaO: 2-18%, preferably BaO: 4-15%, more preferably BaO: 5-12%; and/or CaO: 0-18%, preferably CaO: 0 to 16.5%, more preferably CaO: 0-8%; and/or SrO: 0 to 8%, preferably SrO: 0 to 5%, more preferably SrO: 0-2%; and/or MgO: 0-8%, preferably MgO: 0 to 5%, more preferably MgO: 0-2%; and/or Li₂O: 1 to 12%, preferably Li₂O: 1 to 10%, more preferably Li₂O: 1-9%; and/or Na₂O: 0 to 10%, preferably Na₂O: 0.5 to 8%, more preferably Na₂O: 1-6%; and/or K₂O: 0 to 8%, preferably K₂O: 0 to 5%, more preferably K₂O: 0 to 4 percent; and/or La₂O₃: 0 to 14%, preferably La₂O₃: 2 to 12%, more preferably La₂O₃: 4-10%; and/or Gd₂O₃: 0 to 10%, preferably Gd₂O₃: 0 to 5%, more preferably Gd₂O₃: 0 to 3 percent; and/or Y₂O₃: 0 to 10%, preferably Y₂O₃: 0 to 5%, more preferably Y₂O₃: 0 to 3 percent; and/or Yb₂O₃: 0 to 10%, preferably Yb₂O₃: 0 to 5%, more preferably Yb₂O₃：0～3％。

15. A specific dispersion optical glass according to any one of claims 1 to 4, wherein the composition does not contain B₂O₃(ii) a And/or does not contain TiO₂(ii) a And/or does not contain WO₃(ii) a And/or does not contain Ta₂O₅(ii) a And/or does not contain SrO; and/or does not contain MgO; and/or does not contain CaO; and/or does not contain Gd₂O₃(ii) a And/or does not contain Y₂O₃。

16. A special dispersion optical glass according to any one of claims 1 to 4, wherein the refractive index n of the special dispersion optical glass_d1.68 to 1.82, preferably 1.70 to 1.80, more preferably 1.71 to 1.79, and still more preferably 1.73 to 1.77; and/or Abbe number v_d31 to 40, preferably 32 to 38, and more preferably 33 to 37.

17. A special dispersion optical glass according to any one of claims 1 to 4, wherein P of the special dispersion optical glass_g,FA value of 0.7000 or less, preferably 0.6500 or less, more preferably 0.6000 or less; and/or Δ P_g,FThe value is 0 or less, preferably-0.0010 or less, more preferably-0.0020 or less, and still more preferably-0.0030 or less.

18. The special dispersion optical glass as claimed in any one of claims 1 to 4, wherein the density p of the special dispersion optical glass is 3.80g/cm³Hereinafter, it is preferably 3.70g/cm³Hereinafter, more preferably 3.60g/cm³The following; and/or coefficient of thermal expansion alpha_-30/70℃Is 100 x 10^-7Preferably 90X 10 or less,/K^-7A value of not more than 85X 10^-7below/K; and/or transition temperature T_gIs 600 ℃ or lower, preferably 590 ℃ or lower, more preferably 580 ℃ or lower, and further preferably 570 ℃ or lower; and/or lambda₈₀Less than or equal to 410nm, preferably lambda₈₀Less than or equal to 400nm, more preferably lambda₈₀Less than or equal to 395 nm; and/or lambda₅Less than or equal to 340nm, preferably lambda₅Less than or equal to 335nm, more preferably lambda₅Less than or equal to 330 nm; and/or stability against water action D_WIs 2 or more, preferably 1; and/or stability against acid action D_AIs 2 or more, preferably 1; and/or Knoop hardness H_KIs 520X 10⁷Pa or more, preferably 540X 10⁷Pa or more, more preferably 550X 10⁷Pa or more, more preferably 570X 10⁷Pa or above.

19. A glass preform made of the special dispersion optical glass according to any one of claims 1 to 18.

20. An optical element, characterized in that it is made of the special dispersion optical glass according to any one of claims 1 to 18 or the glass preform according to claim 19.

21. An optical device comprising the special dispersion optical glass according to any one of claims 1 to 18, or comprising the optical element according to claim 20.