CN112142322B

CN112142322B - Optical glass, glass preform, optical element and optical instrument

Info

Publication number: CN112142322B
Application number: CN202011048975.3A
Authority: CN
Inventors: 匡波
Original assignee: CDGM Glass Co Ltd
Current assignee: CDGM Glass Co Ltd
Priority date: 2020-09-29
Filing date: 2020-09-29
Publication date: 2022-04-15
Anticipated expiration: 2040-09-29
Also published as: CN112142322A

Abstract

The present invention provides an optical glass containing B₂O₃、SiO₂、Ln₂O₃And ZnO as an essential component, the components of which are expressed in weight percent: SiO 2₂+B₂O₃30-50%; SiO 2₂/B₂O₃0.03 to 0.3; ln₂O₃：33～55％；B₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃) 0.4 to 1.2; b is₂O₃+La₂O₃55-85%; ZnO/B₂O₃0.12 to 0.6; (ZnO + Gd)₂O₃)/(La₂O₃+SiO₂) 0.1 to 0.6; ZnO/(Gd)₂O₃+Y₂O₃) 0.4 to 3.0; (La)₂O₃+Y₂O₃)/(ZnO+SiO₂) 1.2 to 7.0; ZnO/(La)₂O₃+Gd₂O₃) 0.15 to 0.65, a refractive index of the optical glass of 1.76 or less, and an Abbe number of 58 or less. Through reasonable component design, the invention obtains the optical glass with lower transition temperature with lower raw material cost.

Description

Optical glass, glass preform, optical element and optical instrument

Technical Field

The invention relates to optical glass, in particular to optical glass which has low raw material cost and is suitable for precision die pressing, and a glass prefabricated member, an optical element and an optical instrument which are made of the optical glass.

Background

Optical glass is a glass material used for manufacturing lenses, prisms, mirrors, windows, and the like in optical instruments or mechanical systems. The mainstream method for manufacturing optical glass into optical elements at present is precision press molding (including direct press molding and secondary press molding), and lenses manufactured by using precision press molding technology are generally not ground and polished, thereby reducing raw material consumption, reducing labor and material costs, and reducing environmental pollution, and the technology can produce optical elements in large quantities at low cost. The precision press molding is a process of press-molding a glass preform with a high precision mold having a predetermined product shape under a certain temperature and pressure to obtain a glass product having a final product shape and an optical function. Various optical glass products such as spherical lenses, aspherical lenses, prisms, diffraction gratings, etc. can be manufactured by precision press-molding techniques.

In precision press molding, in order to transfer a high-precision mold surface to a glass product, it is necessary to press-mold a glass preform at a high temperature, and at this time, the mold surface is easily oxidized and eroded under the high temperature and pressure even in a protective atmosphere. Since the pressing temperature must be lowered in order to prolong the life of the mold and suppress damage to the mold due to a high-temperature environment, the transition temperature (T) of the glass material used for press molding_g) It needs to be as low as possible.

CN101389574A publicAn optical glass with a refractive index of 1.65-1.72 and an Abbe number of 47-57 is provided, and CN1666967A discloses an optical glass with a refractive index of 1.65-1.71 and an Abbe number of 55-60, wherein the optical glass comprises a large amount of Gd₂O₃The cost of the glass raw material is high, which is not favorable for the economy of the optical glass.

Disclosure of Invention

The invention aims to solve the technical problem of providing the optical glass which has low raw material cost and is suitable for precision mould pressing.

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

(1) optical glass containing B₂O₃、SiO₂、Ln₂O₃And ZnO as an essential component, the components of which are expressed in weight percent, wherein:

SiO₂+B₂O₃30-50%;

SiO₂/B₂O₃0.03 to 0.3;

Ln₂O₃：33～55％；

B₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃) 0.4 to 1.2;

B₂O₃+La₂O₃55-85%;

ZnO/B₂O₃0.12 to 0.6;

(ZnO+Gd₂O₃)/(La₂O₃+SiO₂) 0.1 to 0.6;

ZnO/(Gd₂O₃+Y₂O₃) 0.4 to 3.0;

(La₂O₃+Y₂O₃)/(ZnO+SiO₂) 1.2 to 7.0;

ZnO/(La₂O₃+Gd₂O₃) Is in the range of 0.15 to 0.65,

the refractive index n of the optical glass_dHas an Abbe number v of 1.76 or less_dLn of 58 or less₂O₃Is La₂O₃、Gd₂O₃、Y₂O₃、Yb₂O₃、Lu₂O₃The total content of (a).

(2) The optical glass according to (1), whose composition is expressed in weight percentage, wherein:

SiO₂+B₂O₃35 to 47 percent; and/or

SiO₂/B₂O₃0.05 to 0.25; and/or

Ln₂O₃: 38-52%; and/or

B₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃) 0.5 to 1.0; and/or

B₂O₃+La₂O₃60-80%; and/or

ZnO/B₂O₃0.15 to 0.45; and/or

(ZnO+Gd₂O₃)/(La₂O₃+SiO₂) 0.15 to 0.45; and/or

ZnO/(Gd₂O₃+Y₂O₃) 0.5 to 2.0; and/or

(La₂O₃+Y₂O₃)/(ZnO+SiO₂) 1.5 to 5.0; and/or

ZnO/(La₂O₃+Gd₂O₃) Is in the range of 0.22 to 0.5,

the Ln₂O₃Is La₂O₃、Gd₂O₃、Y₂O₃、Yb₂O₃、Lu₂O₃The total content of (a).

(3) The optical glass according to (1), whose composition is expressed in weight percentage, wherein:

SiO₂+B₂O₃38-45%; and/or

SiO₂/B₂O₃0.1 to 0.2; and/or

Ln₂O₃: 41-50%; and/or

B₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃) 0.6 to 0.9; and/or

B₂O₃+La₂O₃63-75%; and/or

ZnO/B₂O₃0.2 to 0.35; and/or

(ZnO+Gd₂O₃)/(La₂O₃+SiO₂) 0.18 to 0.4; and/or

ZnO/(Gd₂O₃+Y₂O₃) 0.6 to 1.5; and/or

(La₂O₃+Y₂O₃)/(ZnO+SiO₂) 2.0 to 4.0; and/or

ZnO/(La₂O₃+Gd₂O₃) Is in the range of 0.25 to 0.4,

(4) The optical glass according to (1), whose composition is expressed in weight percentage, wherein: ZnO/B₂O₃0.24 to 0.32; and/or ZnO/(Gd)₂O₃+Y₂O₃) 0.75 to 1.2.

(5) The optical glass according to any one of (1) to (4), which comprises, in terms of weight percent: b is₂O₃: 25-45%; and/or SiO₂: 1-12%; and/or La₂O₃: 26-45%; and/or Gd₂O₃: 0 to 9 percent; and/or Y₂O₃: 4-19%; and/or ZnO: 4-18%; and/or Li₂O: 0 to 10 percent; and/or Na₂O: 0-6%; and/or K₂O: 0-6%; and/or RO: 0 to 9 percent; and/or ZrO₂: 0 to 10 percent; and/or Yb₂O₃: 0 to 10 percent; and/or TiO₂: 0 to 5 percent; and/or Al₂O₃: 0 to 5 percent; and/or Nb₂O₅: 0 to 5 percent; and/or WO₃: 0 to 5 percent; and/or GeO₂: 0 to 5 percent; and/or Lu₂O₃: 0 to 10 percent; and/or Bi₂O₃: 0 to 5 percent; and/or P₂O₅: 0 to 5 percent; and/or Ta₂O₅: 0 to 5 percent; and/or F: 0 to 5 percent; and/or a clarifying agent: 0-1%, wherein RO is one or more of MgO, CaO, SrO and BaO, and a clarifying agent is Sb₂O₃、SnO₂、SnO、CeO₂One or more of (a).

(6) The optical glass according to any one of (1) to (5), which comprises the following components in percentage by weight:

(SiO₂+RO)/La₂O₃0.05 to 0.5; and/or

RO/Y₂O₃Is 1.0 or less; and/or

RO/Li₂O is 0.7 or less; and/or

Gd₂O₃/Li₂The content of O is less than 1.0,

the RO is one or more of MgO, CaO, SrO and BaO.

(7) The optical glass according to any one of (1) to (5), which comprises the following components in percentage by weight: b is₂O₃: 28-42%; and/or SiO₂: 2-10%; and/or La₂O₃: 30-40%; and/or Gd₂O₃: 0-6%; and/or Y₂O₃: 5-15%; and/or ZnO: 6-15%; and/or Li₂O: 0.5-8%; and/or Na₂O: 0 to 3 percent; and/or K₂O: 0 to 3 percent; and/or RO: 0 to 5 percent; and/or ZrO₂: 0.1-7%; and/or Yb₂O₃: 0 to 5 percent; and/or TiO₂: 0 to 3 percent; and/or Al₂O₃: 0 to 3 percent; and/or Nb₂O₅: 0 to 3 percent; and/or WO₃: 0 to 3 percent; and/or GeO₂: 0 to 3 percent; and/or Lu₂O₃: 0 to 5 percent; and/or Bi₂O₃: 0 to 3 percent; and/or P₂O₅: 0 to 3 percent; and/or Ta₂O₅: 0 to 3 percent; and/or F: 0 to 3 percent; and/or a clarifying agent: 0-0.5%, the RO is one or more of MgO, CaO, SrO and BaO, and the clarifying agent is Sb₂O₃、SnO₂、SnO、CeO₂One or more of (a).

(8) The optical glass according to any one of (1) to (5), which comprises the following components in percentage by weight:

(SiO₂+RO)/La₂O₃0.08 to 0.3; and/or

RO/Y₂O₃Is less than 0.5; and/or

RO/Li₂O is 0.5 or less; and/or

Gd₂O₃/Li₂The content of O is less than or equal to 0.5,

the RO is one or more of MgO, CaO, SrO and BaO.

(9) The optical glass according to any one of (1) to (5), which comprises the following components in percentage by weight: b is₂O₃: 31-38%; and/or SiO₂: 4-9%; and/or La₂O₃: 33 to 38 percent; and/or Gd₂O₃: 0 to 3 percent; and/or Y₂O₃: 7-14%; and/or ZnO: greater than 8% but less than or equal to 13%, preferably ZnO: 8.5-11.5%; and/or Li₂O: 1-5%; and/or Na₂O: 0-2%; and/or K₂O: 0-2%; and/or RO: 0-2%; and/or ZrO₂: 0.5-4%; and/or Yb₂O₃: 0-2%; and/or TiO₂: 0 to 1 percent; and/or Al₂O₃: 0 to 1 percent; and/or Nb₂O₅: 0 to 1 percent; and/or WO₃: 0 to 1 percent; and/or GeO₂: 0 to 1 percent; and/or Lu₂O₃: 0-2%; and/or Bi₂O₃: 0 to 1 percent; and/or P₂O₅: 0 to 1 percent; and/or Ta₂O₅: 0 to 1 percent; and/or F: 0 to 1 percent; and/or a clarifying agent: 0-0.1%, the RO is one or more of MgO, CaO, SrO and BaO, and the clarifying agent is Sb₂O₃、SnO₂、SnO、CeO₂One or more of (a).

(10) The optical glass according to any one of (1) to (5), which comprises the following components in percentage by weight:

(SiO₂+RO)/La₂O₃0.1 to 0.2; and/or

RO/Y₂O₃Is 0.2 or less; and/or

RO/Li₂O is 0.2 or less; and/or

Gd₂O₃/Li₂O is 0.3 or less, preferably Gd₂O₃/Li₂The content of O is less than 0.15,

the RO is one or more of MgO, CaO, SrO and BaO.

(11) The optical glass according to any one of (1) to (5), which comprises the following components in percentage by weight: b is₂O₃、SiO₂、La₂O₃、Y₂O₃、ZnO、Li₂O、ZrO₂The total content of (B) is 91% or more, preferably B₂O₃、SiO₂、La₂O₃、Y₂O₃、ZnO、Li₂O、ZrO₂The total content of (B) is 93% or more, and B is more preferably₂O₃、SiO₂、La₂O₃、Y₂O₃、ZnO、Li₂O、ZrO₂The total content of (A) is 95% or more, and B is more preferably B₂O₃、SiO₂、La₂O₃、Y₂O₃、ZnO、Li₂O、ZrO₂The total content of (A) is 98% or more.

(12) The optical glass according to any one of (1) to (5), wherein Gd is not contained in the component₂O₃(ii) a And/or does not contain RO; and/or does not contain TiO₂(ii) a And/or does not contain Al₂O₃(ii) a And/or no Nb₂O₅(ii) a And/or does not contain WO₃(ii) a And/or does not contain GeO₂(ii) a And/or does not contain Lu₂O₃(ii) a And/or does not contain Bi₂O₃(ii) a And/or does not contain P₂O₅(ii) a And/or does not contain Ta₂O₅(ii) a And/or F is not contained, and the RO is one or more of MgO, CaO, SrO and BaO.

(13) The optical glass according to any one of (1) to (5), wherein the refractive index n of the optical glass_d1.65 to 1.75, preferably 1.67 to 1.74, more preferably 1.68 to 1.73, and further preferably 1.69 to 1.72; abbe number v_dIs 50 to 57, preferably 51 to 56, and more preferably 52 to 55.

(14) The optical glass according to any one of (1) to (5), wherein the optical glass has a weatherability CR of 2 or more, preferably 1; and/or stability against water action D_WIs 2 or more, preferably 1; and/or a density rho of 4.10g/cm³Hereinafter, it is preferably 4.00g/cm³Hereinafter, more preferably 3.90g/cm³The following; and/or lambda₈₀Less than or equal to 380nm, preferably lambda₈₀Less than or equal to 370nm, more preferably lambda₈₀Less than or equal to 365 nm; and/or lambda₅Less than or equal to 290nm, preferably lambda₅Less than or equal to 285nm, more preferably lambda₅Less than or equal to 280 nm; and/or the degree of bubbling is class A or more, preferably class A₀More preferably A or more₀₀A stage; and/or coefficient of thermal expansion alpha_20/300℃Is 95X 10^-7Preferably 90X 10 or less,/K^-7A value of not more than 85X 10^-7A value of 80X 10 or less, more preferably 80K or less^-7below/K; and/or transition temperature T_gIs 620 ℃ or lower, preferably 610 ℃ or lower, more preferably 600 ℃ or lower; and/or the upper limit temperature of crystallization is 1200 ℃ or lower, preferably 1150 ℃ or lower, and more preferably 1100 ℃ or lower.

(15) A glass preform made of the optical glass according to any one of (1) to (14).

(16) An optical element produced from the optical glass according to any one of (1) to (14) or the glass preform according to (15).

(17) An optical device comprising the optical glass according to any one of (1) to (14) and/or the optical element according to (16).

The invention has the beneficial effects that: through reasonable component design, the invention can obtain the optical glass with lower transition temperature with lower raw material cost.

Detailed Description

The optical glass of the present invention is obtained by the following steps, which are not limited to the above-described embodiments, and can be appropriately modified within the scope of the object of the present invention. Although the description of the overlapping portions may be omitted as appropriate, the gist of the present invention is not limited thereto, and the optical glass of the present invention may be simply referred to as glass in the following description.

[ optical glass ]

The ranges of the respective components (components) of the 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 >

In the invention B₂O₃And SiO₂Are all network forming components, by reacting B₂O₃And SiO₂Total content of (B)₂O₃+SiO₂At least 30%, the glass forming stability of the glass can be improved, the weather resistance of the glass can be optimized, and B is preferred₂O₃+SiO₂Is 35% or more, more preferably B₂O₃+SiO₂More than 38 percent; if B is₂O₃+SiO₂If the glass refractive index exceeds 50%, the glass refractive index is difficult to meet the design requirements, and the devitrification resistance is lowered, so that B₂O₃+SiO₂Is 50% or less, preferably 47% or less, more preferably 45% or less.

B₂O₃In the present invention, the network-forming component improves the thermal stability of the glass and improves the meltability of the glass, and thus the glass having no melting residue of the glass raw material can be obtained, and in the present invention, the content of B is 25% or more₂O₃To obtain the above effects, B is preferable₂O₃The content of (B) is 28% or more, and B is more preferably₂O₃The content of (B) is more than 31%. But when B is₂O₃When the content of (A) is too large, the refractive index of the glass is lowered and the chemical stability is deteriorated, so that B in the present invention₂O₃The upper limit of the content of (B) is 45%, preferably 42%, more preferably 38%.

SiO₂Has the effects of improving the chemical stability of glass, maintaining the viscosity suitable for the formation of molten glass and reducing the erosion of refractory materials, and the content of SiO is more than 1 percent in the invention₂To obtain the above effects, SiO is preferable₂The content of (A) is 2% or more, and SiO is more preferable₂The content of (A) is 4% or more. 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 12%, preferably 10%, more preferably 9%.

In some embodiments of the invention, the SiO is provided by₂Content of (A) and (B)₂O₃Ratio between contents of (A) SiO₂/B₂O₃Within the range of 0.03-0.3, the glass has proper high-temperature viscosity, the homogenization and clarification of the glass are facilitated, the anti-crystallization performance of the glass can be improved, the glass forming is facilitated, and SiO is preferably selected₂/B₂O₃0.05 to 0.25, more preferably SiO₂/B₂O₃0.1 to 0.2.

Ln₂O₃(Ln₂O₃Is La₂O₃、Gd₂O₃、Y₂O₃、Yb₂O₃、Lu₂O₃Total content of) can increase the refractive index of the glass and adjust the dispersion, Ln in the present invention₂O₃The content of (B) is more than 33%, preferably Ln₂O₃Is 38% or more, more preferably Ln₂O₃The content of (A) is more than 41%; if Ln₂O₃The content of (b) exceeds 55%, the stability and light transmittance of the glass are reduced, and the refractive index exceeds the design requirement. Thus, Ln₂O₃The content of (b) is 55% or less, preferably 52% or less, more preferably 50% or less.

La₂O₃Is a high-refraction low-dispersion component, can raise refractive index of glass, regulate dispersion and reduce high-temp. viscosity of glass, in the invention La₂O₃The content of (A) is 26% or more, preferably La₂O₃The content of (B) is 30% or more, more preferably La₂O₃The content of (B) is 33% or more. On the other hand, by mixing La₂O₃The content of (b) is limited to 45% or less, and the devitrification of the glass can be reduced by improving the stability of the glass, and the temperature coefficient of refractive index and the density rise can be suppressed from exceeding the design requirements. Thus, La₂O₃The content of (b) is 45% or less, preferably 40% or less, more preferably 38% or less.

In some embodiments of the invention, by controlling B₂O₃And La₂O₃Total content of (B)₂O₃+La₂O₃Within the range of 55-85%, the stability and the anti-crystallization performance of the glass can be improved, the glass has proper viscosity, the glass is favorably formed, and B is preferably selected₂O₃+La₂O₃60 to 80%, more preferably B₂O₃+La₂O₃Is 63 to 75%.

Gd₂O₃Can improve the optical glass to a certain extentThermal stability of glass, adjusting thermal expansion coefficient and refractive index of glass when Gd₂O₃When the content exceeds 9%, the density of the glass increases remarkably, and the acid resistance of the glass deteriorates. Thus, Gd is present in the invention₂O₃The content of (b) is 9% or less, preferably 6% or less, more preferably 3% or less. In some embodiments, it is further preferred that no Gd is present₂O₃。

Y₂O₃Has the effect of improving the refractive index of the glass, and the glass also contains Y₂O₃And La₂O₃By incorporating 4% or more of Y in the glass, the glass is improved in meltability and devitrification resistance and the glass density is reduced while maintaining a high refractive index and a low dispersion₂O₃To obtain the above effects, it is preferable to contain 5% or more of Y₂O₃More preferably, it contains 7% or more of Y₂O₃. If Y is₂O₃The content of (A) exceeds 19%, the stability and devitrification resistance of the glass are lowered, and the transition temperature is raised. Thus Y is₂O₃The upper limit of the content of (B) is 19%, preferably 15%, more preferably 14%.

In some embodiments of the invention, if B₂O₃Content of (A) and La₂O₃、Gd₂O₃、Y₂O₃The total content La of₂O₃+Gd₂O₃+Y₂O₃Ratio B between₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃) If it is less than 0.4, the light transmittance of the glass is lowered, the thermal stability is lowered, and if B is₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃) If the refractive index exceeds 1.2, the chemical stability of the glass is deteriorated and the refractive index is difficult to satisfy the design requirements. Therefore, B is preferred₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃) 0.4 to 1.2, and more preferably B₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃) 0.5 to 1.0, and preferably B₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃) 0.6 to 0.9.

Yb₂O₃And is also a component imparting high-refractive-index low-dispersion property to the glass, which is an optional component in the present invention, and when the content exceeds 10%, the devitrification resistance and chemical stability of the glass are lowered, and thus Yb₂O₃The content of (B) is limited to 0 to 10%, preferably 0 to 5%, more preferably 0 to 2%, and further preferably no Yb₂O₃。

The present invention contains 10% or less of Lu₂O₃The rare earth element may act synergistically with other rare earth elements to further improve the stability of the glass, but the content is limited to 10% or less, preferably 5% or less, more preferably 2% or less, and further preferably not containing Lu because the cost is expensive and the incorporation into the glass is disadvantageous for reducing the production cost₂O₃。

In the system glass, ZnO can adjust the refractive index and dispersion of the glass, reduce the transition temperature, improve the anti-crystallization performance of the glass, and improve the stability of the glass, and meanwhile, ZnO can also reduce the high-temperature viscosity of the glass, so that the glass can be smelted at a lower temperature, and the light transmittance of the glass is improved. In the present invention, the above-mentioned effects are obtained by containing 4% or more of ZnO, and the content of ZnO is preferably 6% or more, more preferably more than 8%, and still more preferably 8.5% or more. On the other hand, if the content of ZnO is more than 18%, the glass abrasion is deteriorated, platinum particles are easily generated during melting, the difficulty of molding is increased, and the devitrification resistance of the glass is deteriorated. Therefore, the content of ZnO is limited to 18% or less, preferably 15% or less, more preferably 13% or less, and still more preferably 11.5% or less.

In some embodiments of the invention, if ZnO/(La) is used₂O₃+Gd₂O₃) When the value of (A) is less than 0.15, the glass has a reduced bubble fraction, and if ZnO/(La) is used₂O₃+Gd₂O₃) A value of (D) of more than 0.65 lowers the viscosity of the glass and improves the moldabilityAnd decreases. Therefore, ZnO/(La) is preferable₂O₃+Gd₂O₃) 0.15 to 0.65, more preferably ZnO/(La)₂O₃+Gd₂O₃) 0.22 to 0.5. Further, in some embodiments of the invention, by controlling ZnO/(La)₂O₃+Gd₂O₃) In the range of 0.25-0.4, the thermal expansion coefficient of the glass can be further optimized, and the processing yield and the thermal shock resistance of the glass element are improved. Therefore, ZnO/(La) is more preferable₂O₃+Gd₂O₃) 0.25 to 0.4.

In some embodiments of the invention, if (ZnO + Gd)₂O₃)/(La₂O₃+SiO₂) A value of less than 0.1, the chemical stability of the glass is lowered, if (ZnO + Gd)₂O₃)/(La₂O₃+SiO₂) When the value of (A) exceeds 0.6, the thermal expansion coefficient of the glass increases and the thermal stability decreases. Therefore, (ZnO + Gd) is preferable₂O₃)/(La₂O₃+SiO₂) 0.1 to 0.6, more preferably (ZnO + Gd)₂O₃)/(La₂O₃+SiO₂) 0.15 to 0.45, and more preferably (ZnO + Gd)₂O₃)/(La₂O₃+SiO₂) 0.18 to 0.4.

In some embodiments of the invention, the ZnO content and Gd are controlled₂O₃And Y₂O₃Total content of (b) Gd₂O₃+Y₂O₃Ratio between ZnO/(Gd)₂O₃+Y₂O₃) In the range of 0.4-3.0, the glass has excellent weather resistance while obtaining a low transition temperature. Therefore, ZnO/(Gd) is preferable₂O₃+Y₂O₃) 0.4 to 3.0, and more preferably ZnO/(Gd)₂O₃+Y₂O₃) 0.5 to 2.0, and further preferably ZnO/(Gd)₂O₃+Y₂O₃) 0.6 to 1.5. Further, in some embodiments, by controlling ZnO/(Gd)₂O₃+Y₂O₃) The value of (A) is in the range of 0.75 to 1.2, andfurther, ZnO/(Gd) is more preferable because the glass can be made more optimally bubble-free and the glass can be made more highly graded₂O₃+Y₂O₃) 0.75 to 1.2.

In some embodiments of the invention, if (La)₂O₃+Y₂O₃)/(ZnO+SiO₂) If the value of (A) is less than 1.2, the optical constants of the glass hardly satisfy the design requirements, and if (La)₂O₃+Y₂O₃)/(ZnO+SiO₂) When the value of (A) exceeds 7.0, the glass tends to have reduced devitrification resistance and moldability, and tends to have an increased density. Therefore, (La) is preferable₂O₃+Y₂O₃)/(ZnO+SiO₂) 1.2 to 7.0, more preferably (La)₂O₃+Y₂O₃)/(ZnO+SiO₂) Is 1.5 to 5.0, and (La) is more preferable₂O₃+Y₂O₃)/(ZnO+SiO₂) Is 2.0 to 4.0.

In some embodiments of the invention, the ZnO content is determined by the combination of the ZnO content and B₂O₃Ratio between contents of (3) ZnO/B₂O₃Within the range of 0.12-0.6, the viscosity of the glass can be adjusted, the degree of striae of the glass is optimized, and ZnO/B is preferably selected₂O₃0.15 to 0.45. Further, by controlling ZnO/B₂O₃In the range of 0.2 to 0.35, the glass can be improved in weather resistance, and ZnO/B is more preferable₂O₃0.2 to 0.35. Further, by controlling ZnO/B₂O₃In the range of 0.24-0.32, the thermal expansion coefficient of the glass can be further optimized, and the processing yield and the thermal shock resistance of the glass element are improved. Therefore, ZnO/B is more preferable₂O₃0.24 to 0.32.

ZrO₂Is a high-refraction low-dispersion component, can improve the refractive index and adjust the dispersion of glass in the glass, and can improve the devitrification resistance of the glass, if ZrO is used, the glass is transparent, has good optical properties, and can be used for making glass products with high refractive index and high dispersion₂The content of (b) is more than 10%, the difficulty of melting the glass increases, the melting temperature increases, and further, inclusions in the glass and the light transmittance decrease may be caused. Thus, ZrO₂The content is 10% or less, preferably 0.1 to 7%, more preferably0.5 to 4 percent.

Li₂O can lower the glass transition temperature, but its high content is disadvantageous in chemical stability and thermal expansion coefficient of the glass, and therefore, Li in the present invention₂The content of O is 10% or less, preferably 0.5 to 8%, more preferably 1 to 5%.

In some embodiments of the invention, Gd is controlled₂O₃With Li₂Ratio between contents of O Gd₂O₃/Li₂O is 1.0 or less, and is advantageous for reducing the density of the glass and reducing the weight of the glass, and Gd is preferable₂O₃/Li₂O is 0.5 or less, and Gd is more preferable₂O₃/Li₂O is 0.3 or less. Further, by reacting Gd₂O₃/Li₂O is 0.15 or less, and the bubble fraction of the glass can be improved to increase the bubble fraction of the glass, so Gd is more preferable₂O₃/Li₂O is 0.15 or less.

Na₂O has the effects of improving the meltability of the glass, increasing the melting effect of the glass, and lowering the transition temperature of the glass, such as Na₂The content of O exceeds 6%, the chemical stability and weather resistance of the glass are lowered, and therefore Na₂The content of O is 0-6%, preferably Na₂The content of O is 0 to 3%, and Na is more preferable₂The content of O is 0-2%. In some embodiments, it is further preferred that Na is absent₂O。

K₂O has the effect of improving the thermal stability and melting property of the glass, but when the content exceeds 6%, the devitrification resistance of the glass is lowered and the chemical stability of the glass is deteriorated, so that K in the present invention₂The content of O is 6% or less, preferably K₂The content of O is 0 to 3%, more preferably 0 to 2%. In some embodiments, it is further preferred that K is absent₂O。

RO is alkaline earth metal oxide, and RO is one or more of MgO, CaO, SrO and BaO. RO improves the meltability of the glass and adjusts the optical constant of the glass, and when the RO content exceeds 9%, it is difficult to obtain high-refractive-index low-dispersion optical properties. Therefore, the RO content in the present invention is 0 to 9%, preferably 0 to 5%, more preferably 0 to 2%, and further preferably no RO is contained.

In some embodiments of the invention, if (SiO)₂+RO)/La₂O₃A value of less than 0.05 lowers the formability of the glass, if (SiO)₂+RO)/La₂O₃The value of (A) exceeds 0.5, the optical constants and bubble eliminating ability of the glass are lowered. Therefore, (SiO) is preferable₂+RO)/La₂O₃0.05 to 0.5, more preferably (SiO)₂+RO)/La₂O₃0.08 to 0.3, preferably (SiO)₂+RO)/La₂O₃0.1 to 0.2.

In some embodiments of the invention, the RO/Y is controlled by₂O₃The value of (A) is 1.0 or less, and the increase of the thermal expansion coefficient of the glass can be prevented, preferably RO/Y₂O₃Is 0.5 or less, and RO/Y is more preferable₂O₃Is 0.2 or less.

In some embodiments of the invention, RO/Li is mixed with a solvent₂The value of O is controlled to 0.7 or less, and the optical glass can obtain low dispersion property while maintaining good melting property of the glass, and RO/Li is preferable₂The value of O is 0.5 or less, and RO/Li is more preferable₂The value of O is 0.2 or less.

TiO₂Has the function of obviously improving the refractive index and the dispersion of the glass, and the proper content of the glass can make the glass more stable and reduce the viscosity of the glass. But TiO 2₂When the content exceeds 5%, the Abbe number of the glass rapidly increases, the glass tends to be devitrified, the glass transition temperature rises, and the glass tends to be colored during press molding. Thus, TiO in the present invention₂The content of (A) is 5% or less, preferably TiO₂The content of (B) is 3% or less, more preferably 1% or less, and further preferably no TiO₂。

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. Thus, Al of the invention₂O₃The content of (A) is 0 to 5%, preferably 0 to 3%, more preferably 0 to 1%, and further preferably no Al is contained₂O₃。

Nb₂O₅Is a high-refraction high-dispersion component, can improve the refractive index and the devitrification resistance of the glass and reduce the thermal expansion coefficient of the glass, if Nb is used₂O₅Too high content of (b), the thermal and chemical stability of the glass is reduced, and the light transmittance is reduced. Therefore, Nb in the present invention₂O₅The content of (A) is 0 to 5%, preferably 0 to 3%, more preferably 0 to 1%, and further preferably no Nb₂O₅。

WO₃Can improve the refractive index and mechanical strength of the glass, if WO₃When the content of (B) exceeds 5%, the glass is deteriorated in thermal stability and devitrification resistance. Thus, WO₃The upper limit of the content of (B) is 5%, preferably 3%, more preferably 1%. In some embodiments, it is further preferred that WO is absent₃。

Ta₂O₅The glass has the effects of improving the refractive index and improving the devitrification resistance of the glass, but the content of the glass is too high, the chemical stability of the glass is reduced, and the optical constant is difficult to control to a desired range; 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 of the present invention₂O₅The content is limited to 0 to 5%, preferably 0 to 3%, more preferably 0 to 1%, and further preferably no Ta is contained₂O₅。

GeO₂Has the effects of improving the refractive index and the devitrification resistance of the glass, is an optional component of the optical glass, and has high content of GeO₂The glass has a low light transmittance, and since it is an expensive raw material and the glass cost efficiency is low, the content is limited to 5% or less, preferably 3% or less, more preferably 1% or less, and further preferably no GeO is contained₂。

Bi₂O₃Is an optional component capable of increasing the refractive index of the glass and reducing the glass transition temperature, Bi₂O₃The content of (A) is high, and the light transmittance of the glass is reduced, the abrasion degree and the hot press stability are deteriorated, and the density is remarkably increased. Thus, it is possible to provideIn the glass of the present invention, Bi₂O₃The content of (B) is 5% or less, preferably 3% or less, more preferably 1% or less, and further preferably Bi is not contained₂O₃。

The glass of the present invention may contain an appropriate amount of P₂O₅To improve the devitrification resistance of the glass, but P₂O₅At a high content, the chemical stability of the glass is lowered, so that P₂O₅The content of (A) is 5% or less, preferably 3% or less, more preferably 1% or less, and further preferably contains no P₂O₅。

In the invention, 0-1% of Sb is added₂O₃、SnO、SnO₂、CeO₂One or more of the components are 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%, and more preferably 0-0.1%. 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 invention₂O₃The amount of (B) is 0 to 1%, more preferably 0 to 0.5%, still more preferably 0 to 0.1%. 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, and further preferably 0 to 0.1%; the content of SnO is preferably 0 to 1%, more preferably 0 to 0.5%, and further preferably 0 to 0.1%. CeO (CeO)₂Action and addition amount ratio of (B) and SnO₂The content is preferably 0 to 1%, more preferably 0 to 0.5%, still more preferably 0 to 0.1%, and further more preferably not contained.

Since F (fluorine) can adjust the dispersion of the glass to lower the transition temperature, and when the content is high, the glass stability is deteriorated to lower the devitrification resistance, and the volatility causes the optical constants of the glass to be unstable to deteriorate the striae, the content of F is 5% or less, preferably 3% or less, more preferably 1% or less, and further preferably no F is contained.

In some embodiments of the present invention, B is preferred for optical glasses with lower transition temperature, density and thermal expansion coefficient, higher bubble and streak ratings, excellent chemical stability and weatherability₂O₃、SiO₂、La₂O₃、Y₂O₃、ZnO、Li₂O、ZrO₂The total content of (B) is 91% or more, and B is more preferably B₂O₃、SiO₂、La₂O₃、Y₂O₃、ZnO、Li₂O、ZrO₂The total content of (B) is 93% or more, and B is more preferably B₂O₃、SiO₂、La₂O₃、Y₂O₃、ZnO、Li₂O、ZrO₂The total content of (B) is 95% or more, and B is more preferably₂O₃、SiO₂、La₂O₃、Y₂O₃、ZnO、Li₂O、ZrO₂The total content of (A) is 98% or more.

< 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 performance of the 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 optical glass of the present invention_d) The lower limit of (b) is 1.65, preferably 1.67, more preferably 1.68, and still more preferably 1.69. In some embodiments, the refractive index (n) of the optical glass of the present invention_d) The upper limit of (b) is 1.76, preferably 1.75, more preferably 1.74, still more preferably 1.73, and still more preferably 1.72.

In some embodiments, the Abbe number (v) of the optical glass of the present invention_d) The lower limit of (2) is 50, preferably 51, more preferably 52. In some embodiments, the Abbe number (v) of the optical glass of the present invention_d) The upper limit of (b) is 58, preferably 57, more preferably 56, and still more preferably 55.

< Density >

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

In some embodiments, the optical glass of the present invention has a density (. rho.) of 4.10g/cm³Hereinafter, it is preferably 4.00g/cm³Hereinafter, more preferably 3.90g/cm³The following.

< coefficient of thermal expansion >

Coefficient of thermal expansion (alpha) of optical glass_20/300℃) And testing the data at 20-300 ℃ according to a method specified in GB/T7962.16-2010.

In some embodiments, the optical glass of the present invention has a coefficient of thermal expansion (α)_20/300℃) Is 95X 10^-7Preferably 90X 10 or less,/K^-7A value of not more than 85X 10^-7A value of 80X 10 or less, more preferably 80K or less^-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 optical glass of the present invention_g) Is 620 ℃ or lower, preferably 610 ℃ or lower, and more preferably 600 ℃ 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 λ of the optical glass of the present invention₈₀Less than or equal to 380nm, preferably lambda₈₀Less than or equal to 370nm, more preferably lambda₈₀Less than or equal to 365 nm.

In some embodiments, the λ of the optical glass of the present invention₅Less than or equal to 290nm, preferably lambda₅Less than or equal to 285nm, more preferably lambda₅Less than or equal to 280 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 optical glass of the present invention has stability to water effects (D)_W) Is 2 or more, preferably 1.

< upper limit temperature of crystallization >

The crystallization performance of the glass is measured by adopting a gradient temperature furnace method, the glass is made into a sample of 180 multiplied by 10mm, the side surface is polished, the sample is put into a furnace with a temperature gradient (10 ℃/cm) to be heated to the temperature of the highest temperature zone of 1200 ℃, the sample is taken out and naturally cooled to the room temperature after being kept for 4 hours, the crystallization condition of the glass is observed under a microscope, and the highest temperature corresponding to the occurrence of crystals of the glass is the crystallization upper limit temperature of the glass.

In some embodiments, the optical glass of the present invention has an upper crystallization limit temperature of 1200 ℃ or less, preferably 1150 ℃ or less, and more preferably 1100 ℃ or less.

< degree of bubbling >

The degree of blistering of the optical glass was measured according to the method prescribed in GB/T7962.8-2010.

In some embodiments, the optical glass of the present invention has a bubble degree of class A or more, preferably class A₀More preferably A or more₀₀And (4) stages.

< weather resistance >

The weatherability (CR) of the optical glass was measured in accordance with the following method.

And placing the sample in a test box in a saturated water vapor environment with the relative humidity of 90%, and alternately circulating at 40-50 ℃ every 1 hour for 15 periods. The weather resistance categories were classified according to the amount of change in turbidity before and after the sample was left, and Table 1 shows the weather resistance categories.

TABLE 1 weather resistance Classification

In some embodiments, the optical glass has a weatherability (CR) of 2 or more, preferably 1.

[ method for producing optical glass ]

The method for manufacturing the optical glass comprises the following steps: the glass is produced by adopting conventional raw materials and processes, including but not limited to carbonate, nitrate, sulfate, phosphate, metaphosphate, hydroxide, oxide, fluoride and the like as raw materials, burdening according to a conventional method, putting the burdened materials into a smelting furnace (such as a platinum crucible) at 1200-1400 ℃ for smelting, clarifying and homogenizing to obtain homogeneous molten glass without bubbles and undissolved substances, and casting and annealing the molten glass in a mold. 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 optical glass produced by 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 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 optical glass of the present invention, and use the preform for reheat press forming, precision press forming, or the like to produce optical elements such as lenses, prisms, or the like.

The glass preform of the present invention and the optical element are each formed of the above-described optical glass of the present invention. The glass preform of the present invention has excellent characteristics possessed by optical glass; the optical element of the present invention has excellent characteristics of optical glass, and can provide optical elements such as various 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 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 2 to 3 were obtained by the above-mentioned method for producing optical glasses. The characteristics of each glass were measured by the test method described in the present invention, and the measurement results are shown in tables 2 to 3.

Table 2.

Table 3.

< 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 and gratings were produced by using the glasses obtained in examples 1 to 20 of optical glass by, for example, direct dropping molding, polishing or hot press molding.

< optical element example >

The preforms obtained by the embodiment of the glass preform can be annealed again or annealed on the premise of ensuring the stress, namely, the refractive index is finely adjusted while the internal stress of the glass is reduced, so that the optical characteristics such as the refractive index and the like reach required values.

Next, each preform is subjected to precision press molding, or subjected to grinding, and polishing 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, a prism, or a grating. The surface of the resulting optical element may be coated with an antireflection film.

< optical Instrument example >

The optical element obtained by the above-described optical element embodiment is used for, for example, imaging devices, sensors, microscopes, medical technologies, digital projection, communications, optical communication technologies/information transmission, optics/lighting in the automobile field, photolithography, excimer lasers, wafers, computer chips, and integrated circuits and electronic devices including such circuits and chips, or for image pickup devices and apparatuses in the vehicle-mounted field, by forming an optical component or an optical assembly by using one or more optical elements through optical design.

Claims

1. Optical glassGlass, characterized in that it contains B₂O₃、SiO₂、Ln₂O₃And ZnO as an essential component, the components of which are expressed in weight percent, wherein:

SiO₂+B₂O₃30-50%;

SiO₂/B₂O₃0.03 to 0.3;

Ln₂O₃：33～55％；

B₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃) 0.4 to 1.2;

B₂O₃+La₂O₃61.64-85%;

ZnO/B₂O₃0.12 to 0.6;

(ZnO+Gd₂O₃)/(La₂O₃+SiO₂) 0.1 to 0.6;

ZnO/(Gd₂O₃+Y₂O₃) 0.4 to 3.0;

(La₂O₃+Y₂O₃)/(ZnO+SiO₂) 1.2 to 3.531;

ZnO/(La₂O₃+Gd₂O₃) Is in the range of 0.15 to 0.65,

the refractive index n of the optical glass_dHas an Abbe number v of 1.76 or less_d50 to 58 parts of Ln₂O₃Is La₂O₃、Gd₂O₃、Y₂O₃、Yb₂O₃、Lu₂O₃The total content of (a).

2. An optical glass according to claim 1, characterised in that its components are expressed in weight percentages, wherein:

SiO₂+B₂O₃35 to 47 percent; and/or

SiO₂/B₂O₃0.05 to 0.25; and/or

Ln₂O₃：38～52 percent; and/or

B₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃) 0.5 to 1.0; and/or

B₂O₃+La₂O₃61.64-80%; and/or

ZnO/B₂O₃0.15 to 0.45; and/or

(ZnO+Gd₂O₃)/(La₂O₃+SiO₂) 0.15 to 0.45; and/or

ZnO/(Gd₂O₃+Y₂O₃) 0.5 to 2.0; and/or

(La₂O₃+Y₂O₃)/(ZnO+SiO₂) 1.5 to 3.531; and/or

ZnO/(La₂O₃+Gd₂O₃) Is in the range of 0.22 to 0.5,

3. An optical glass according to claim 1, characterised in that its components are expressed in weight percentages, wherein:

SiO₂+B₂O₃38-45%; and/or

SiO₂/B₂O₃0.1 to 0.2; and/or

Ln₂O₃: 41-50%; and/or

B₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃) 0.6 to 0.9; and/or

B₂O₃+La₂O₃63-75%; and/or

ZnO/B₂O₃0.2 to 0.35; and/or

(ZnO+Gd₂O₃)/(La₂O₃+SiO₂) 0.18 to 0.4; and/or

ZnO/(Gd₂O₃+Y₂O₃) 0.6 to 1.5; and/or

(La₂O₃+Y₂O₃)/(ZnO+SiO₂) 2.0 to 3.531; and/or

ZnO/(La₂O₃+Gd₂O₃) Is in the range of 0.25 to 0.4,

4. An optical glass according to claim 1, characterised in that its components are expressed in weight percentages, wherein: ZnO/B₂O₃0.24 to 0.32; and/or ZnO/(Gd)₂O₃+Y₂O₃) 0.75 to 1.2.

5. An optical glass according to claim 1, characterised in that its components are expressed in weight percentages, wherein: (La)₂O₃+Y₂O₃)/(ZnO+SiO₂) Is 2.134 to 3.531.

6. An optical glass according to claim 1, characterised in that its components are expressed in weight percentages, wherein: (La)₂O₃+Y₂O₃)/(ZnO+SiO₂) 2.616-3.531.

7. An optical glass according to claim 1, characterised in that its components are expressed in weight percentages, wherein: (La)₂O₃+Y₂O₃)/(ZnO+SiO₂) 2.877-3.497.

8. An optical glass according to claim 1, characterised in that its components are expressed in weight percentages, wherein: (La)₂O₃+Y₂O₃)/(ZnO+SiO₂) 2.905-3.497.

9. An optical glass according to claim 1, characterised in that its components are expressed in weight percentages, wherein: ZnO/(Gd)₂O₃+Y₂O₃) 0.4 to 0.981.

10. An optical glass according to claim 1, characterised in that its components are expressed in weight percentages, wherein: ZnO/(Gd)₂O₃+Y₂O₃) 0.5 to 0.981.

11. An optical glass according to claim 1, characterised in that its components are expressed in weight percentages, wherein: ZnO/(Gd)₂O₃+Y₂O₃) 0.6 to 0.981.

12. An optical glass according to claim 1, characterised in that its components are expressed in weight percentages, wherein: ZnO/(Gd)₂O₃+Y₂O₃) 0.6 to 0.899.

13. An optical glass according to claim 1, characterised in that its components are expressed in weight percentages, wherein: ZnO/(Gd)₂O₃+Y₂O₃) 0.633-0.847.

14. An optical glass according to claim 1, characterised in that its components are expressed in weight percentages, wherein: ZnO/(Gd)₂O₃+Y₂O₃) 0.75 to 0.847.

15. An optical glass according to claim 1, characterised in that its components are expressed in weight percentages, wherein: b is₂O₃/(La₂O₃+Gd₂O₃+Y₂O₃) 0.68 to 0.9.

16. An optical glass according to claim 1, characterised in that its components are expressed in weight percentages, wherein: (ZnO + Gd)₂O₃)/(La₂O₃+SiO₂) 0.18 to 0.29.

17. An optical glass according to claim 1, characterised in that its components are expressed in weight percentages, wherein: ZnO/(La)₂O₃+Gd₂O₃) 0.25 to 0.352.

18. An optical glass according to claim 1, characterised in that its components are expressed in weight percentages, wherein: b is₂O₃+La₂O₃67.37-73.48%.

19. An optical glass according to any one of claims 1 to 18, comprising, in weight percent: b is₂O₃: 25-45%; and/or SiO₂: 1-12%; and/or La₂O₃: 26-45%; and/or Gd₂O₃: 0 to 9 percent; and/or Y₂O₃: 4-19%; and/or ZnO: 4-18%; and/or Li₂O: 0 to 10 percent; and/or Na₂O: 0-6%; and/or K₂O: 0-6%; and/or RO: 0 to 9 percent; and/or ZrO₂: 0 to 10 percent; and/or Yb₂O₃: 0 to 10 percent; and/or TiO₂: 0 to 5 percent; and/or Al₂O₃: 0 to 5 percent; and/or Nb₂O₅: 0 to 5 percent; and/or WO₃: 0 to 5 percent; and/or GeO₂: 0 to 5 percent; and/or Lu₂O₃: 0 to 10 percent; and/or Bi₂O₃: 0 to 5 percent; and/or P₂O₅: 0 to 5 percent; and/or Ta₂O₅: 0 to 5 percent; and/or F: 0 to 5 percent; and/or a clarifying agent: 0-1%, wherein RO is one or more of MgO, CaO, SrO and BaO, and a clarifying agent is Sb₂O₃、SnO₂、SnO、CeO₂One or more of (a).

20. An optical glass according to any one of claims 1 to 18, wherein the composition is expressed in weight percent, wherein:

(SiO₂+RO)/La₂O₃0.05 to 0.5; and/or

RO/Y₂O₃Is 1.0 or less; and/or

RO/Li₂O is 0.7 or less; and/or

Gd₂O₃/Li₂The content of O is less than 1.0,

the RO is one or more of MgO, CaO, SrO and BaO.

21. An optical glass according to any one of claims 1 to 18, wherein the composition is expressed in weight percent, wherein: b is₂O₃: 28-42%; and/or SiO₂: 2-10%; and/or La₂O₃: 30-40%; and/or Gd₂O₃: 0-6%; and/or Y₂O₃: 5-15%; and/or ZnO: 6-15%; and/or Li₂O: 0.5-8%; and/or Na₂O: 0 to 3 percent; and/or K₂O: 0 to 3 percent; and/or RO: 0 to 5 percent; and/or ZrO₂: 0.1-7%; and/or Yb₂O₃: 0 to 5 percent; and/or TiO₂: 0 to 3 percent; and/or Al₂O₃: 0 to 3 percent; and/or Nb₂O₅: 0 to 3 percent; and/or WO₃: 0 to 3 percent; and/or GeO₂: 0 to 3 percent; and/or Lu₂O₃: 0 to 5 percent; and/or Bi₂O₃: 0 to 3 percent; and/or P₂O₅: 0 to 3 percent; and/or Ta₂O₅: 0 to 3 percent; and/or F: 0 to 3 percent; and/or a clarifying agent: 0-0.5%, the RO is one or more of MgO, CaO, SrO and BaO, and the clarifying agent is Sb₂O₃、SnO₂、SnO、CeO₂One or more of (a).

22. An optical glass according to any one of claims 1 to 18, wherein the composition is expressed in weight percent, wherein:

(SiO₂+RO)/La₂O₃0.08 to 0.3; and/or

RO/Y₂O₃Is less than 0.5; and/or

RO/Li₂O is 0.5 or less; and/or

Gd₂O₃/Li₂The content of O is less than or equal to 0.5,

the RO is one or more of MgO, CaO, SrO and BaO.

23. An optical glass according to any one of claims 1 to 18, wherein the composition is expressed in weight percent, wherein: b is₂O₃: 31-38%; and/or SiO₂: 4-9%; and/or La₂O₃: 33 to 38 percent; and/or Gd₂O₃: 0 to 3 percent; and/or Y₂O₃: 7-14%; and/or ZnO: greater than 8% but less than or equal to 13%; and/or Li₂O: 1-5%; and/or Na₂O: 0-2%; and/or K₂O: 0-2%; and/or RO: 0-2%; and/or ZrO₂: 0.5-4%; and/or Yb₂O₃: 0-2%; and/or TiO₂: 0 to 1 percent; and/or Al₂O₃: 0 to 1 percent; and/or Nb₂O₅: 0 to 1 percent; and/or WO₃: 0 to 1 percent; and/or GeO₂: 0 to 1 percent; and/or Lu₂O₃: 0-2%; and/or Bi₂O₃: 0 to 1 percent; and/or P₂O₅: 0 to 1 percent; and/or Ta₂O₅: 0 to 1 percent; and/or F: 0 to 1 percent; and/or a clarifying agent: 0-0.1%, the RO is one or more of MgO, CaO, SrO and BaO, and the clarifying agent is Sb₂O₃、SnO₂、SnO、CeO₂One or more of (a).

24. An optical glass according to any one of claims 1 to 18, wherein the composition is expressed in weight percent, wherein: ZnO: 8.5-11.5%.

25. An optical glass according to any one of claims 1 to 18, wherein the composition is expressed in weight percent, wherein:

(SiO₂+RO)/La₂O₃0.1 to 0.2; and/or

RO/Y₂O₃Is 0.2 or less; and/or

RO/Li₂O is 0.2 or less; and/or

Gd₂O₃/Li₂The content of O is less than 0.3,

the RO is one or more of MgO, CaO, SrO and BaO.

26. An optical glass according to any one of claims 1 to 18, wherein the composition is expressed in weight percent, wherein: gd (Gd)₂O₃/Li₂O is 0.15 or less.

27. An optical glass according to any one of claims 1 to 18, wherein the composition is expressed in weight percent, wherein: b is₂O₃、SiO₂、La₂O₃、Y₂O₃、ZnO、Li₂O、ZrO₂The total content of (B) is 91% or more.

28. An optical glass according to any one of claims 1 to 18, wherein the composition is expressed in weight percent, wherein: b is₂O₃、SiO₂、La₂O₃、Y₂O₃、ZnO、Li₂O、ZrO₂The total content of (B) is 93% or more.

29. An optical glass according to any one of claims 1 to 18, wherein the composition is expressed in weight percent, wherein: b is₂O₃、SiO₂、La₂O₃、Y₂O₃、ZnO、Li₂O、ZrO₂The total content of (A) is 95% or more.

30. An optical glass according to any one of claims 1 to 18, wherein the composition is expressed in weight percent, wherein: b is₂O₃、SiO₂、La₂O₃、Y₂O₃、ZnO、Li₂O、ZrO₂The total content of (A) is 98% or more.

31. An optical glass according to any one of claims 1 to 18, characterised in that it does not contain Gd₂O₃(ii) a And/or does not contain RO; and/or does not contain TiO₂(ii) a And/or does not contain Al₂O₃(ii) a And/or no Nb₂O₅(ii) a And/or does not contain WO₃(ii) a And/or does not contain GeO₂(ii) a And/or does not contain Lu₂O₃(ii) a And/or does not contain Bi₂O₃(ii) a And/or does not contain P₂O₅(ii) a And/or does not contain Ta₂O₅(ii) a And/or F is not contained, and the RO is one or more of MgO, CaO, SrO and BaO.

32. An optical glass according to any one of claims 1 to 18, wherein the refractive index n of the optical glass_d1.65 to 1.75; abbe number v_dIs 50 to 57.

33. An optical glass according to any one of claims 1 to 18, wherein the refractive index n of the optical glass_d1.65 to 1.75; abbe number v_d51 to 56.

34. An optical glass according to any one of claims 1 to 18, wherein the refractive index n of the optical glass_d1.65 to 1.75; abbe number v_dIs 52 to 55.

35. According to claim 1The optical glass according to any one of to 18, wherein the refractive index n of the optical glass_d1.67 to 1.74; abbe number v_dIs 50 to 57.

36. An optical glass according to any one of claims 1 to 18, wherein the refractive index n of the optical glass_d1.67 to 1.74; abbe number v_d51 to 56.

37. An optical glass according to any one of claims 1 to 18, wherein the refractive index n of the optical glass_d1.67 to 1.74; abbe number v_dIs 52 to 55.

38. An optical glass according to any one of claims 1 to 18, wherein the refractive index n of the optical glass_d1.68-1.73; abbe number v_dIs 50 to 57.

39. An optical glass according to any one of claims 1 to 18, wherein the refractive index n of the optical glass_d1.68-1.73; abbe number v_d51 to 56.

40. An optical glass according to any one of claims 1 to 18, wherein the refractive index n of the optical glass_d1.68-1.73; abbe number v_dIs 52 to 55.

41. An optical glass according to any one of claims 1 to 18, wherein the refractive index n of the optical glass_d1.69 to 1.72; abbe number v_dIs 50 to 57.

42. An optical glass according to any one of claims 1 to 18, wherein the refractive index n of the optical glass_d1.69 to 1.72; abbe number v_d51 to 56.

43. According to any one of claims 1 to 18The optical glass is characterized in that the refractive index n of the optical glass_d1.69 to 1.72; abbe number v_dIs 52 to 55.

44. The optical glass according to any one of claims 1 to 18, wherein the optical glass has a weatherability CR of 2 or more types; and/or stability against water action D_WIs more than 2 types; and/or a density rho of 4.10g/cm³The following; and/or lambda₈₀Less than or equal to 380 nm; and/or lambda₅Less than or equal to 290 nm; and/or the bubble degree is above A level; and/or coefficient of thermal expansion alpha_20/300℃Is 95X 10^-7below/K; and/or transition temperature T_gBelow 620 ℃; and/or the upper limit temperature of crystallization is 1200 ℃ or lower.

45. The optical glass according to any one of claims 1 to 18, wherein the optical glass has a weatherability CR of class 1; and/or stability against water action D_WIs of type 1; and/or a density rho of 4.00g/cm³The following; and/or lambda₈₀Less than or equal to 370 nm; and/or lambda₅Less than or equal to 285 nm; and/or a degree of bubbling of A₀More than grade; and/or coefficient of thermal expansion alpha_20/300℃Is 90X 10^-7below/K; and/or transition temperature T_gBelow 610 ℃; and/or the upper limit temperature of crystallization is 1150 ℃ or lower.

46. The optical glass according to any one of claims 1 to 18, wherein the optical glass has a density p of 3.90g/cm³The following; and/or lambda₈₀Less than or equal to 365 nm; and/or lambda₅Less than or equal to 280 nm; and/or a degree of bubbling of A₀₀A stage; and/or coefficient of thermal expansion alpha_20/300℃Is 85X 10^-7below/K; and/or transition temperature T_gBelow 600 ℃; and/or the upper limit temperature of crystallization is 1100 ℃ or lower.

47. An optical glass according to any one of claims 1 to 18, wherein the thermal expansion of the optical glassCoefficient of expansion alpha_20/300℃Is 80X 10^-7and/K is less than or equal to.

48. A glass preform, characterized in that it is made of the optical glass according to any one of claims 1 to 47.

49. An optical element produced from the optical glass according to any one of claims 1 to 47 or the glass preform according to claim 48.

50. An optical instrument comprising the optical glass according to any one of claims 1 to 47 and/or comprising the optical element according to claim 49.