CN109970338B

CN109970338B - Optical glass, glass preform, optical element and optical instrument

Info

Publication number: CN109970338B
Application number: CN201910348753.4A
Authority: CN
Inventors: 孙伟
Original assignee: CDGM Glass Co Ltd
Current assignee: CDGM Glass Co Ltd
Priority date: 2019-04-28
Filing date: 2019-04-28
Publication date: 2022-05-06
Anticipated expiration: 2039-04-28
Also published as: CN109970338A

Abstract

The invention provides an optical glass, which comprises the following components in percentage by weight: b is₂O₃：20～40％、La₂O₃：20～45％、Gd₂O₃：1～35％、Y₂O₃: 0 to 15%, the refractive index nd of the optical glass is 1.70 to 1.80, the Abbe number vd is 48 to 58, and the Knoop hardness H is_KIs 700 x 10⁷Pa or above. Through reasonable component design, the optical glass obtained by the invention has higher hardness while having the expected refractive index and Abbe number.

Description

Optical glass, glass preform, optical element and optical instrument

Technical Field

The invention relates to optical glass, in particular to optical glass with a refractive index of 1.70-1.80 and an Abbe number of 48-58, and a glass prefabricated member, an optical element and an optical instrument which are made of the optical glass.

Background

With the continuous fusion of optics and electronic information science and new material science, the application of optical glass as a photoelectron base material in the technical fields of light transmission, light storage, photoelectric display and the like is rapidly advanced. In recent years, optical elements and optical instruments have been rapidly developed in terms of digitization, integration, and high definition, and higher demands have been made on the performance of optical glasses used for optical elements of optical instruments and devices.

The optical glass with the refractive index of 1.70-1.80 and the Abbe number of 48-58 has very important significance for simplifying an optical system and improving the imaging quality in the fields of optical design and optical communication. At present, the optical glass meeting the optical performance is widely applied to the fields of vehicle-mounted monitoring and security protection and the like, and the optical glass is required to have higher hardness so as to resist the abrasion of sand and stones in the driving process of a vehicle and prolong the service life of the optical glass.

Disclosure of Invention

For the above reasons, the technical problem to be solved by the present invention is to provide an optical glass having a refractive index of 1.70 to 1.80, an abbe number of 48 to 58, and a high hardness.

The technical scheme for solving the technical problem is as follows: the optical glass comprises the following components in percentage by weight: b is₂O₃：20～40％、La₂O₃：20～45％、Gd₂O₃：1～35％、Y₂O₃: 0 to 15%, the refractive index nd of the optical glass is 1.70 to 1.80, the Abbe number vd is 48 to 58, and the Knoop hardness H is_KIs 700 x 10⁷Pa or above.

Further, the optical glass comprises the following components in percentage by weight: SiO 2₂：0～10％、ZrO₂：0～10％、ZnO：0～9.5％、Yb₂O₃：0～10％、WO₃：0～10％、TiO₂：0～10％、RO：0～10％、Rn₂O：0～10％、Al₂O₃：0～10％、Ta₂O₅：0～10％、Nb₂O₅: 0-10% of a clarifying agent: 0-2%, RO is one or more of MgO, CaO, SrO and BaO, Rn₂O is Li₂O、Na₂O、K₂One or more of O and Sb as clarifier₂O₃、SnO₂SnO and CeO₂One or more of (a).

The optical glass comprises the following components in percentage by weight: b is₂O₃：20～40％、La₂O₃：20～45％、Gd₂O₃：1～35％、Y₂O₃：0～15％、SiO₂：0～10％、ZrO₂：0～10％、ZnO：0～9.5％、Yb₂O₃：0～10％、WO₃：0～10％、TiO₂：0～10％、RO：0～10％、Rn₂O：0～10％、Al₂O₃：0～10％、Ta₂O₅：0～10％、Nb₂O₅: 0-10% of a clarifying agent: 0-2%, RO is one or more of MgO, CaO, SrO and BaO, and Rn₂O is Li₂O、Na₂O、K₂One or more of O and Sb as clarifier₂O₃、SnO₂SnO and CeO₂One or more of (a).

Further, the optical glass comprises the following components in percentage by weight: b is₂O₃: 23 to 36%, and/or La₂O₃: 25-40%, and/or Y₂O₃: 1 to 10%, and/or Nb₂O₅: 0 to 5%, and/or ZrO₂: 0.5-8%, and/or ZnO: 0 to 6%, and/or SiO₂: 0 to 8%, and/or Gd₂O₃: 6 to 30% and/or Yb₂O₃: 0 to 5%, and/or WO₃: 0 to 5%, and/or TiO₂: 0-5%, and/or RO: 0 to 5%, and/or Rn₂O: 0 to 5%, and/or Al₂O₃: 0 to 5%, and/or Ta₂O₅: 0-5%, and/or a clarifying agent: 0-1%, RO is one or more of MgO, CaO, SrO and BaO, and Rn₂O is Li₂O、Na₂O、K₂One or more of O and Sb as clarifier₂O₃、SnO₂SnO and CeO₂One or more of (a).

Further, the optical glass comprises the following components in percentage by weight: b is₂O₃: 25-35% and/or La₂O₃: 30-40%, and/or Y₂O₃: 2 to 8%, and/or Nb₂O₅: 0 to 2%, and/or ZrO₂: 1-5%, and/or ZnO: 0 to 4%, and/or SiO₂: 1 to 6%, and/or Gd₂O₃: 11 to 28% and/or Yb₂O₃: 0 to 3%, and/or WO₃: 0 to 2%, and/or TiO₂: 0-2%, and/or RO: less than 1%, and/or Rn₂O: less than 1%, and/or Al₂O₃: 0 to 2%, and/or Ta₂O₅: 0-2%, and/or a clarifying agent: 0-0.5%, RO is one or more of MgO, CaO, SrO and BaO, and Rn₂O is Li₂O、Na₂O、K₂One or more of O and Sb as clarifier₂O₃、SnO₂SnO and CeO₂One or more of (a).

Furthermore, the optical glass comprises the components expressed by weight percent of ZnO/Y₂O₃Is 1.0 or less, preferably ZnO/Y₂O₃Is 0.8 or less, and ZnO/Y is more preferable₂O₃Is 0.5 or less, and ZnO/Y is more preferable₂O₃Is 0.4 or less.

Further, the optical glass comprises the components of, by weight percent, Gd₂O₃/(Gd₂O₃+Y₂O₃) 0.5 to 1.0, preferably Gd₂O₃/(Gd₂O₃+Y₂O₃) 0.6 to 0.95, more preferably Gd₂O₃/(Gd₂O₃+Y₂O₃) 0.7 to 0.9.

Further, the optical glass has the composition expressed by weight percentage (Y)₂O₃+ZrO₂)/La₂O₃0.02 to 0.6, preferably (Y)₂O₃+ZrO₂)/La₂O₃0.05 to 0.5, and more preferably (Y)₂O₃+ZrO₂)/La₂O₃Is 0.1 to 0.4, and (Y) is more preferably₂O₃+ZrO₂)/La₂O₃0.15 to 0.35.

Further, the components of the optical glass are expressed by weight percentage (SiO)₂+ZnO)/La₂O₃0.01 to 0.45, preferably (SiO)₂+ZnO)/La₂O₃0.03 to 0.35, more preferably (SiO)₂+ZnO)/La₂O₃0.05 to 0.25.

Further, the optical glass comprises the following components in percentage by weight, (Rn)₂O+Ta₂O₅)/(SiO₂+ZrO₂) Is 0.5 or less, preferably (Rn)₂O+Ta₂O₅)/(SiO₂+ZrO₂) Is 0.3 or less, more preferably (Rn)₂O+Ta₂O₅)/(SiO₂+ZrO₂) Is 0.2 or less, and (Rn) is more preferable₂O+Ta₂O₅)/(SiO₂+ZrO₂) Is 0.1 or less.

Further, the components of the optical glass are expressed by weight percentage, (Rn)₂O+RO)/Y₂O₃Is 0.5 or less, preferably (Rn)₂O+RO)/Y₂O₃Is 0.3 or less, more preferably (Rn)₂O+RO)/Y₂O₃Is 0.2 or less, and (Rn) is more preferable₂O+RO)/Y₂O₃Is 0.1 or less.

Further, the optical glass comprises the following components in percentage by weight, B₂O₃/(SiO₂+La₂O₃+Y₂O₃) 0.35 to 1.0, preferably B₂O₃/(SiO₂+La₂O₃+Y₂O₃) 0.45 to 0.9, and more preferably B₂O₃/(SiO₂+La₂O₃+Y₂O₃) 0.5 to 0.8.

Further, the optical glass comprises the components of, by weight percent, Gd₂O₃The content of (a) is 16-25%.

Further, the optical glass does not contain F and/or WO in the components₃And/or TiO-free₂And/or RO-free, and/or Rn-free₂O, and/or does not contain Ta₂O₅And/or does not contain Al₂O₃The RO is one or more of MgO, CaO, SrO and BaO, and Rn₂O is Li₂O、Na₂O、K₂One or more of O.

Further, the optical glass comprises the components of SiO in percentage by weight₂、B₂O₃、La₂O₃、Gd₂O₃And ZrO₂The total content of (A) is more than 92%; SiO is preferred₂、B₂O₃、La₂O₃、Gd₂O₃、Y₂O₃And ZrO₂The total content of (A) is 95% or more; more preferably SiO₂、B₂O₃、La₂O₃、Gd₂O₃、Y₂O₃And ZrO₂The total content of (A) is 97% or more; further preferred is SiO₂、B₂O₃、La₂O₃、Gd₂O₃、Y₂O₃、ZrO₂ZnO and Sb₂O₃The total content of (A) is 99% or more.

Furthermore, the refractive index nd of the optical glass is 1.70-1.80, preferably 1.72-1.79, more preferably 1.73-1.78, and further preferably 1.74-1.77; the Abbe number vd is 48 to 58, preferably 49 to 56, more preferably 50 to 55, and further preferably 51 to 54.

Further, the stability of the optical glass against water action D_WIs 2 or more, preferably 1; and/or Knoop hardness H_KIs 700 x 10⁷Pa or more, preferably 710X 10⁷Pa or more, more preferably 720X 10⁷Pa or more, more preferably 725X 10⁷Pa or above; and/or a density rho of 4.60g/cm³Hereinafter, it is preferably 4.50g/cm³Hereinafter, more preferably 4.45g/cm³The following; and/or coefficient of thermal expansion alpha_-30/70℃Is 80X 10^-7Preferably 70X 10 or less,/K^-7A value of not more than K, more preferably 65X 10^-7below/K; and/or lambda₈₀Less than or equal to 400nm, preferably lambda₈₀Less than or equal to 390nm, more preferably lambda₈₀Less than or equal to 385 nm; and/or lambda₅Less than or equal to 310nm, preferably lambda₅Less than or equal to 300nm, more preferably lambda₅Less than or equal to 295 nm.

The glass preform is made of the optical glass.

And the optical element is made of the optical glass or the glass prefabricated member.

The optical instrument is made of the optical glass or the optical element.

The invention has the beneficial effects that: through reasonable component design, the optical glass obtained by the invention has a refractive index of 1.70-1.80 and an Abbe number of 48-58, and has high hardness.

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 of the optical glass of the present invention are explained below. In the present specification, unless otherwise specified, the contents and total contents of the respective components are all expressed in terms of weight percentage with respect to the total amount of glass matter converted into the composition of oxides. 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%.

Unless otherwise indicated herein, the numerical ranges set forth herein include upper and lower values, and the terms "above" and "below" include the endpoints, and all integers and fractions within the range, and are not limited to the specific values listed in the defined range. 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 >

B₂O₃Is a component forming a glass network structure, is an essential component in the present invention, especially when containing a large amount of La₂O₃And Gd₂O₃In the case of a component having a high refractive index, B needs to be increased₂O₃To maintain stability of the formed glass. In order to achieve the above effects, the present invention introduces more than 20% or more of B₂O₃Preferably, 23% or more of B is introduced₂O₃More preferably, 25% or more of B is introduced₂O₃(ii) a However, when the amount of incorporation exceeds 40%, the chemical stability of the glass is lowered and the refractive index is lowered, and therefore, B of the present invention₂O₃The upper limit of the content of (B) is 40%, preferably 36%, more preferably 35%.

SiO₂The glass network forming body is also a framework of the optical glass, and has the functions of improving the chemical stability of the glass and maintaining the anti-devitrification performance of the glass; but when SiO₂At contents higher than 10%, the glass becomes refractory and the refractive index required by the present invention cannot be obtained. Thus, SiO₂The content of (b) is 0 to 10%, preferably 0 to 8%, more preferably 1 to 6%.

La₂O₃Are essential components for obtaining the desired optical properties of the present invention,in the formulation system of the invention, B₂O₃And La₂O₃The glass can effectively improve the devitrification resistance of the glass and improve the chemical stability of the glass. When La₂O₃When the content of (b) is less than 20%, it is difficult to realize desired optical characteristics; however, when the content exceeds 45%, the devitrification resistance and melting property of the glass are rather deteriorated. Thus, the La of the present invention₂O₃The content of (b) is 20 to 45%, preferably 25 to 40%, more preferably 30 to 40%.

In the present invention, more than 1% of Gd is introduced₂O₃To improve the chemical stability of the optical glass and adjust the thermal expansion coefficient and the refractive index of the glass; however, when the content exceeds 35%, the resistance to devitrification of the glass becomes poor and the transition temperature of the glass increases. Thus Gd is present in the invention₂O₃The content of (b) is 1 to 35%, preferably 6 to 30%, more preferably 11 to 28%, and further preferably 16 to 25%.

The high-refractive low-dispersion component of the invention preferably also incorporates up to 15% Y₂O₃By the simultaneous introduction of Y₂O₃And La₂O₃When the content exceeds 15%, the glass is deteriorated in stability and devitrification resistance. In some embodiments, by introducing 1% or more Y₂O₃And the upper limit temperature and specific gravity of glass crystallization can be reduced. Thus, Y in the present invention₂O₃The content of (b) is 0 to 15%, preferably 1 to 10%, more preferably 2 to 8%.

In some embodiments of the optical glass of the present invention, Gd is added to the glass₂O₃With Gd₂O₃And Y₂O₃Total content of (Gd)₂O₃+Y₂O₃) Ratio of (Gd)₂O₃/(Gd₂O₃+Y₂O₃) Within the range of 0.5-1.0, the optical glass has excellent chemical stability and striae degree; in some embodiments, in particular Gd₂O₃/(Gd₂O₃+Y₂O₃) In the range of 0.6-0.95, the optical glass with low thermal expansion coefficient can be obtained. Thus, Gd₂O₃/(Gd₂O₃+Y₂O₃) 0.5 to 1.0, preferably Gd₂O₃/(Gd₂O₃+Y₂O₃) 0.6 to 0.95, more preferably Gd₂O₃/(Gd₂O₃+Y₂O₃) 0.7 to 0.9.

In some embodiments of the optical glass of the present invention, B is controlled₂O₃With SiO₂、La₂O₃、Y₂O₃Total content of (SiO)₂+La₂O₃+Y₂O₃) Ratio B of₂O₃/(SiO₂+La₂O₃+Y₂O₃) Within the range of 0.35-1.0, the glass forming stability of the glass can be improved, especially the B is controlled₂O₃/(SiO₂+La₂O₃+Y₂O₃) In the range of 0.45-0.9, the glass can have low density and simultaneously the degree of striae of the glass is optimized. Thus, B₂O₃/(SiO₂+La₂O₃+Y₂O₃) Is 0.35 to 1.0, preferably 0.45 to 0.9, and more preferably 0.5 to 0.8.

Yb₂O₃And is also a component imparting high-refractivity, low-dispersion properties, and is an optional component in the present invention, and when it is incorporated in an amount exceeding 10%, the devitrification resistance and chemical stability of the glass are lowered, so that the content thereof is limited to 0 to 10%, preferably 0 to 5%, more preferably 0 to 3%.

ZrO₂Can improve the optical constant of the glass and improve the chemical stability, but the content thereof exceeds 10 percent, and the devitrification resistance of the glass is deteriorated. Thus, the ZrO of the invention₂The content of (b) is 0 to 10%, preferably 0.5 to 8%, more preferably 1 to 5%.

In some embodiments of the optical glass of the present invention, (Y) is preferably₂O₃+ZrO₂)/La₂O₃In the range of 0.02-0.6, the hardness and the bubble degree of the optical glass can be optimized under the condition of having a lower thermal expansion coefficient, and the (Y) is more preferable₂O₃+ZrO₂)/La₂O₃0.05 to 0.5, and (Y) is more preferably₂O₃+ZrO₂)/La₂O₃0.1 to 0.4, more preferably (Y)₂O₃+ZrO₂)/La₂O₃0.15 to 0.35.

ZnO is added into the glass of the system, can adjust the refractive index and dispersion of the glass, reduce the transition temperature of the glass, but the content thereof exceeds 9.5 percent, the anti-crystallization performance of the glass can be reduced, meanwhile, the high-temperature viscosity is smaller, which brings difficulty to molding, and increases the thermal expansion coefficient and the refractive index temperature coefficient of the glass. Therefore, the ZnO content in the invention is 0 to 9.5%, preferably 0 to 6%, and more preferably 0 to 4%.

In some embodiments of the invention, the ZnO/Y is prepared by reacting ZnO/Y₂O₃Below 1.0, the optical glass has excellent chemical stability and low thermal expansion coefficient, especially ZnO/Y₂O₃Under 0.8, the viscosity of the glass can be optimized, and the forming performance of the glass can be improved. Thus ZnO/Y₂O₃The range of (b) is 1.0 or less, preferably 0.8 or less, more preferably 0.5 or less, and further preferably 0.4 or less.

In some embodiments of the invention, (SiO)₂+ZnO)/La₂O₃When the amount is less than 0.01, the light transmittance of the glass is deteriorated, i.e., (SiO)₂+ZnO)/La₂O₃When the refractive index is higher than 0.45, the refractive index of the glass does not satisfy the design requirement, and the hardness is deteriorated. Thus, in some embodiments of the invention, (SiO)₂+ZnO)/La₂O₃The range of (A) is 0.01 to 0.45, preferably 0.03 to 0.35, and more preferably 0.05 to 0.25.

WO₃The glass is a high-refraction high-dispersion component, and can be added into the glass to adjust optical constants and improve the anti-devitrification capability. However, if the content of this component is too large, the transmittance in the short wavelength region of the visible region is lowered. Thus, WO in the present invention₃The content is 10% or less, preferably 5% or less, more preferably 2% or less, and further preferably no incorporation.

TiO₂Is a high-refraction high-dispersion oxide, can obviously improve the refractive index and dispersion of the glass when added into the glass, but if excessive TiO₂When added to glass, the development of low dispersion is difficult to achieve, and the transmittance of glass is significantly reduced and the stability of glass is also deteriorated. Thus, TiO₂The content of (b) is 10% or less, preferably 5% or less, more preferably 2% or less, and further preferably not incorporated.

Nb₂O₅The refractive index of the glass can be increased, and the chemical stability and devitrification resistance of the glass can be improved, but if the content is too large, the dispersion of the glass increases, it is difficult to obtain a glass with a target optical constant, the cost and density of the glass increase, and the short-wave transmittance in the visible light region decreases, so that 10% or less of Nb is introduced in the present invention₂O₅The amount of incorporation is preferably 5% or less, more preferably 2% or less, and still more preferably no incorporation.

Rn₂O is an alkali metal oxide, Rn₂O is Li₂O、Na₂O or K₂One or more of O, when Rn, can improve the melting property of the glass and reduce the glass transition temperature₂When the content of O exceeds 10%, the glass stability is deteriorated, so that Rn of the present invention₂The O content is 0 to 10%, preferably 0 to 5%, more preferably less than 1%, and further preferably no incorporation. In some embodiments of the invention, even small amounts of Li are present₂O, which also results in poor chemical stability and poor devitrification performance of the glass, is particularly preferred in some embodiments to exclude Li₂O。

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 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, it is possible to provideTa of the invention₂O₅The content is limited to 0 to 10%, preferably 0 to 5%, more preferably 0 to 2%. In some embodiments, even small amounts of Ta are included₂O₅May also lead to poor glass stability, and therefore in some embodiments it is particularly preferred not to include Ta₂O₅。

In some embodiments of the invention, Rn₂O and Ta₂O₅Total content (Rn) of₂O+Ta₂O₅) With SiO₂And ZrO₂Total content of (SiO)₂+ZrO₂) Ratio of (Rn)₂O+Ta₂O₅)/(SiO₂+ZrO₂) If the amount exceeds 0.5, the hardness of the optical glass is deteriorated, and the molten glass is corroded more than necessary by the melting bath, thereby lowering the light transmittance of the optical glass. Thus (Rn)₂O+Ta₂O₅)/(SiO₂+ZrO₂) Is 0.5 or less, preferably (Rn)₂O+Ta₂O₅)/(SiO₂+ZrO₂) Is 0.3 or less, more preferably (Rn)₂O+Ta₂O₅)/(SiO₂+ZrO₂) Is 0.2 or less, and (Rn) is more preferable₂O+Ta₂O₅)/(SiO₂+ZrO₂) Is 0.1 or less.

RO is alkaline earth metal oxide, and is one or more of BaO, SrO, CaO or MgO. Addition of RO to the glass improves the melting property of the glass and lowers the glass transition temperature, but when the content of RO exceeds 10%, the devitrification resistance of the glass is lowered. Therefore, the RO content in the present invention is 0 to 10%, preferably 0 to 5%, more preferably less than 1%, and further preferably no incorporation. In some embodiments, even a small amount of BaO contained causes the devitrification property of the glass to tend to deteriorate, and therefore in some embodiments, it is particularly preferable not to contain BaO.

In some embodiments of the invention, Rn₂Total content of O and RO and Y₂O₃Ratio of (Rn)₂O+RO)/Y₂O₃When the amount exceeds 0.5, the optical glass has a reduced devitrification resistance and chemical stability, and the degree of blistering is reduced, so that (Rn)₂O+RO)/Y₂O₃Is 0.5 or less, preferably 0.3 or less, more preferably 0.2 or less, and further preferably 0.1 or less.

Al₂O₃The chemical stability of the glass can be improved, but when the content exceeds 10%, the dispersion of the glass increases and the meltability deteriorates. Thus, Al of the invention₂O₃The content of (b) is 0 to 10%, preferably 0 to 5%, more preferably 0 to 2%, and further preferably no incorporation.

By adding small amounts of Sb₂O₃、SnO、SnO₂、CeO₂One or more of the components may act as a fining agent to improve the fining effect of the glass, but when Sb is present₂O₃At contents exceeding 2%, 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 2%, preferably 0 to 1%, and more preferably 0 to 0.5%. SnO and SnO₂However, when the content exceeds 2%, the glass is colored, or when the glass is heated, softened, press-molded or the like and then re-molded, Sn becomes a starting point of crystal nucleus generation, and thus, devitrification tends to occur. Thus the SnO of the invention₂The content of (b) is preferably 0 to 2%, more preferably 0 to 1%, further preferably 0 to 0.5%, further preferably not contained; the SnO content is preferably 0 to 2%, more preferably 0 to 1%, even more preferably 0 to 0.5%, and even more preferably not contained. CeO (CeO)₂Action and addition amount ratio of (B) and SnO₂The content is preferably 0 to 2%, more preferably 0 to 1%, further preferably 0 to 0.5%, and further preferably not contained.

F can reduce glass dispersion and improve the devitrification resistance of the glass, but the volatilization of the F during the melting and forming process can increase the data fluctuation of the glass, and meanwhile, the volatilization of the F during the forming process can cause the generation of stripes; in addition, volatilization of F can pose a potential safety threat to humans and the environment. In the present invention, the content of F is limited to 4% or less, preferably 3% or less, more preferably 1% or less, and further preferably not incorporated.

In order to achieve the object of the present invention and obtain an optical glass with excellent properties, the glass of the present invention preferably contains SiO in terms of weight percentage₂、B₂O₃、La₂O₃、Gd₂O₃And ZrO₂The total content of (A) is more than 92%; more preferably SiO₂、B₂O₃、La₂O₃、Gd₂O₃、Y₂O₃And ZrO₂The total content of (A) is 95% or more; further preferred is SiO₂、B₂O₃、La₂O₃、Gd₂O₃、Y₂O₃And ZrO₂The total content of (A) is 97% or more; SiO is more preferable₂、B₂O₃、La₂O₃、Gd₂O₃、Y₂O₃、ZrO₂ZnO and Sb₂O₃The total content of (A) is 99% 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 does not contain As₂O₃And PbO. Although As₂O₃Has the effects of eliminating bubbles and better preventing the glass from coloring, but As₂O₃The addition of (b) increases the platinum attack of the glass on the furnace, particularly on the platinum furnace, resulting in more platinum ions entering the glass, which adversely affects the service life of the platinum furnace. PbO can significantly improve the high-refractivity and high-dispersion properties of the glass, but PbO and As₂O₃All cause environmental pollution.

The term "not introduced", "not containing" or "0%" as used herein means that the compound, molecule or element is not intentionally added as a raw material to the optical glass of the present invention; 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 >

The refractive index (nd) and Abbe number (vd) of the optical glass were measured according to the method specified in GB/T7962.1-2010.

The refractive index (nd) of the optical glass is 1.70-1.80, preferably 1.72-1.79, more preferably 1.73-1.78, and further preferably 1.74-1.77; the Abbe number (vd) is 48 to 58, preferably 49 to 56, more preferably 50 to 55, and further preferably 51 to 54.

< stability against Water action >

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

Stability to Water action of the optical glass of the invention (D)_W) Is 2 or more, preferably 1.

< Density >

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

The optical glass of the present invention has a density (. rho.) of 4.60g/cm³Hereinafter, it is preferably 4.50g/cm³Hereinafter, more preferably 4.45g/cm³The following.

< Knoop hardness >

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

The Knoop hardness (H) of the optical glass of the invention_K) Is 700 x 10⁷Pa or more, preferably 710X 10⁷Pa or more, more preferably 720X 10⁷Pa or more, more preferably 725X 10⁷Pa or above.

< coefficient of thermal expansion >

The coefficient of thermal expansion (alpha) of the optical glass of the present invention_-30/70℃) And testing data at-30-70 ℃ according to a method specified in GB/T7962.16-2010.

The coefficient of thermal expansion (. alpha.) of the optical glass of the present invention_-30/70℃) Is 80X 10^-7Preferably 70X 10 or less,/K^-7A value of less than or equal to K, more preferably 65X 10^-7and/K is less than or equal to.

< degree of coloration of optical glass >

Lambda for the degree of coloration of the optical glass of the present invention₈₀/λ₅And (4) showing. Lambda [ alpha ]₈₀Refers to the wavelength, lambda, corresponding to a glass having a transmittance of 80%₅The wavelength corresponding to the glass transmittance of 5% is referred to. Wherein λ is₈₀Was 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.

Optical glass lambda of the present invention₈₀Less than or equal to 400nm, preferably lambda₈₀In the range of less than or equal to 390nm, more preferably lambda₈₀In the range of less than or equal to 385 nm; lambda [ alpha ]₅Less than or equal to 310nm, preferably lambda₅In the range of less than or equal to 300nm, more preferably λ₅Is less than or equal to 295 nm.

[ 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 conventional processes, carbonate, nitrate, sulfate, hydroxide, oxide and the like are used as raw materials, the materials are mixed according to a conventional method, the mixed furnace burden is put into a smelting furnace at 1200-1300 ℃ for smelting, and after clarification, stirring and homogenization, homogeneous molten glass without bubbles and undissolved substances is obtained, and the molten glass is cast in a mold 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 optical glass produced by, for example, grinding or press molding such as reheat press molding or precision press molding. That is, the glass preform may be produced by machining the optical glass by grinding, polishing, or the like, or by producing a preform for press molding from the optical glass, subjecting the preform to reheat press molding, and then polishing, or by precision press molding the preform obtained by polishing.

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, image pickup equipment, display 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 3 were obtained by the above-mentioned method for producing optical glasses. The properties of each glass were measured by the test method described in the present invention, and the measurement results are shown in tables 1 to 3, where K1 in tables 1 to 3 indicates Gd₂O₃/(Gd₂O₃+Y₂O₃) K2 represents ZnO/Y₂O₃K3 denotes (Y)₂O₃+ZrO₂)/La₂O₃K4 denotes (SiO)₂+ZnO)/La₂O₃K5 denotes (Rn)₂O+Ta₂O₅)/(SiO₂+ZrO₂) K6 denotes (Rn)₂O+RO)/Y₂O₃K7 denotes B₂O₃/(SiO₂+La₂O₃+Y₂O₃)。

TABLE 1

TABLE 2

TABLE 3

< glass preform example >

The optical glasses obtained in examples 1 to 10 in table 1 were cut into a predetermined size, and then a release agent was uniformly applied to the surface of the optical glass, followed by heating, softening, and press-molding to prepare preforms of various lenses and prisms 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.

< optical element example >

The preforms obtained in the above examples of glass preforms were annealed to reduce the deformation in the glass and to fine-tune the optical properties such as refractive index to 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 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 glass, characterized in that its components, expressed in weight percent, contain: b is₂O₃：20～40%、La₂O₃：20～45%、Gd₂O₃：1～35%、SiO₂：0～10%、ZrO₂：0～10%、Y₂O₃：0～8%，（Y₂O₃+ZrO₂）/La₂O₃0.215 to 0.6; gd (Gd)₂O₃/（Gd₂O₃+Y₂O₃) 0.726 to 1.0; (SiO)₂+ZnO）/La₂O₃0.065 to 0.45, the refractive index nd of the optical glass is 1.70 to 1.80, the Abbe number vd is 48 to 58, and the Knoop hardness H is_KIs 700 x 10⁷Pa or above, SiO₂、B₂O₃、La₂O₃、Gd₂O₃And ZrO₂The total content of (A) is 92% or more.

2. The optical glass according to claim 1, wherein the composition, expressed in weight percent, further comprises: ZnO: 0 to 9.5% of Yb₂O₃：0～10%、WO₃：0～10%、TiO₂：0～10%、RO：0～10%、Rn₂O：0～10%、Al₂O₃：0～10%、Ta₂O₅：0～10%、Nb₂O₅: 0-10% of a clarifying agent: 0-2%, RO is one or more of MgO, CaO, SrO and BaO, Rn₂O is Li₂O、Na₂O、K₂One or more of O and Sb as clarifier₂O₃、SnO₂SnO and CeO₂One or more of (a).

3. Optical glass, characterized in that its components, expressed in weight percent, contain: b is₂O₃：20～40%、La₂O₃：20～45%、Gd₂O₃：1～35%、Y₂O₃：0～15%、SiO₂：0～10%、ZrO₂：0～10%、ZnO：0～9.5%、Yb₂O₃：0～10%、WO₃：0～10%、TiO₂：0～10%、RO：0～10%、Rn₂O：0～10%、Al₂O₃：0～10%、Ta₂O₅：0～10%、Nb₂O₅: 0-10% of a clarifying agent: 0-2%, (Rn)₂O+Ta₂O₅）/（SiO₂+ZrO₂) Is less than 0.5; (Y)₂O₃+ZrO₂）/La₂O₃0.215 to 0.6; gd (Gd)₂O₃/（Gd₂O₃+Y₂O₃) 0.726 to 1.0; (SiO)₂+ZnO）/La₂O₃0.065-0.45, wherein RO is one or more of MgO, CaO, SrO and BaO, and Rn₂O is Li₂O、Na₂O、K₂One or more of O and Sb as clarifier₂O₃、SnO₂SnO and CeO₂The Abbe number vd of the optical glass is 48-58.

4. An optical glass according to claim 1 or 2, characterised in that its composition, expressed in weight percentages, is such that: b is₂O₃: 23 to 36%, and/or La₂O₃: 25-40%, and/or Y₂O₃: 1 to 8%, and/or Nb₂O₅: 0 to 5%, and/or ZrO₂: 0.5-8%, and/or ZnO: 0 to 6%, and/or SiO₂: 0 to 8%, and/or Gd₂O₃: 6 to 30% and/or Yb₂O₃: 0 to 5%, and/or WO₃: 0 to 5%, and/or TiO₂: 0-5%, and/or RO: 0 to 5%, and/or Rn₂O: 0 to 5%, and/or Al₂O₃: 0 to 5%, andor Ta₂O₅: 0-5%, and/or a clarifying agent: 0-1%, RO is one or more of MgO, CaO, SrO and BaO, Rn₂O is Li₂O、Na₂O、K₂One or more of O and Sb as clarifier₂O₃、SnO₂SnO and CeO₂One or more of (a).

5. An optical glass according to claim 3, characterised in that its composition, expressed in percentages by weight, is such that: b is₂O₃: 23 to 36%, and/or La₂O₃: 25-40%, and/or Y₂O₃: 1 to 10%, and/or Nb₂O₅: 0 to 5%, and/or ZrO₂: 0.5-8%, and/or ZnO: 0 to 6%, and/or SiO₂: 0 to 8%, and/or Gd₂O₃: 6 to 30% and/or Yb₂O₃: 0 to 5%, and/or WO₃: 0 to 5%, and/or TiO₂: 0-5%, and/or RO: 0 to 5%, and/or Rn₂O: 0 to 5%, and/or Al₂O₃: 0 to 5%, and/or Ta₂O₅: 0-5%, and/or a clarifying agent: 0-1%, RO is one or more of MgO, CaO, SrO and BaO, Rn₂O is Li₂O、Na₂O、K₂One or more of O and Sb as clarifier₂O₃、SnO₂SnO and CeO₂One or more of (a).

6. An optical glass according to any one of claims 1 to 3, wherein the composition is expressed in weight percent, wherein: b is₂O₃: 25-35% and/or La₂O₃: 30-40%, and/or Y₂O₃: 2 to 8%, and/or Nb₂O₅: 0 to 2%, and/or ZrO₂: 1-5%, and/or ZnO: 0 to 4%, and/or SiO₂: 1 to 6%, and/or Gd₂O₃: 11 to 28% and/or Yb₂O₃: 0 to 3%, and/or WO₃: 0 to 2%, and/or TiO₂: 0-2%, and/or RO: less than 1%, and/or Rn₂O: less than 1%, and/or Al₂O₃: 0 to 2%, and/or Ta₂O₅: 0-2%, and/or a clarifying agent: 0-0.5%, RO is one or more of MgO, CaO, SrO and BaO, Rn₂O is Li₂O、Na₂O、K₂One or more of O and Sb as clarifier₂O₃、SnO₂SnO and CeO₂One or more of (a).

7. An optical glass according to any one of claims 1 to 3, characterised in that its composition, expressed in weight percent, is ZnO/Y₂O₃Is 1.0 or less.

8. An optical glass according to any one of claims 1 to 3, characterised in that its composition, expressed in weight percent, is ZnO/Y₂O₃Is 0.8 or less.

9. An optical glass according to any one of claims 1 to 3, characterised in that its composition, expressed in weight percent, is ZnO/Y₂O₃Is 0.5 or less.

10. An optical glass according to any one of claims 1 to 3, characterised in that its composition, expressed in weight percent, is ZnO/Y₂O₃Is 0.4 or less.

11. An optical glass according to any one of claims 1 to 3, characterised in that its composition, expressed in weight percentage, is Gd₂O₃/（Gd₂O₃+Y₂O₃) 0.726 to 0.95.

12. An optical glass according to any one of claims 1 to 3, characterised in that its composition, expressed in weight percentage, is Gd₂O₃/（Gd₂O₃+Y₂O₃) 0.726 to 0.9.

13. The E.E. 1E3 the optical glass according to any one of above, wherein the component (Y) is represented by weight percentage₂O₃+ZrO₂）/La₂O₃0.215 to 0.5.

14. An optical glass according to any one of claims 1 to 3, characterised in that its composition, expressed in weight percent, (Y)₂O₃+ZrO₂）/La₂O₃0.215 to 0.4.

15. An optical glass according to any one of claims 1 to 3, characterised in that its composition, expressed in weight percent, (Y)₂O₃+ZrO₂）/La₂O₃0.215 to 0.35.

16. An optical glass according to any one of claims 1 to 3, characterised in that its composition is, in weight percent, (SiO)₂+ZnO）/La₂O₃0.065-0.35.

17. An optical glass according to any one of claims 1 to 3, characterised in that its composition is, in weight percent, (SiO)₂+ZnO）/La₂O₃0.065 to 0.25.

18. An optical glass according to any one of claims 1 to 2, wherein the components are expressed in weight percent (Rn)₂O+Ta₂O₅）/（SiO₂+ZrO₂) Is 0.5 or less.

19. An optical glass according to any of claims 1 to 3, characterised in that its components, expressed in weight percent, (Rn)₂O+Ta₂O₅）/（SiO₂+ZrO₂) Is 0.3 or less.

20. An optical glass according to any one of claims 1 to 3, characterised in that it consists ofRatio representation (Rn)₂O+Ta₂O₅）/（SiO₂+ZrO₂) Is 0.2 or less.

21. An optical glass according to any one of claims 1 to 3, characterised in that its components, expressed in weight percent, (Rn)₂O+Ta₂O₅）/（SiO₂+ZrO₂) Is 0.1 or less.

22. An optical glass according to any one of claims 1 to 3, characterised in that its components, expressed in weight percent, (Rn)₂O+RO）/ Y₂O₃Is 0.5 or less.

23. An optical glass according to any one of claims 1 to 3, characterised in that its components, expressed in weight percent, (Rn)₂O+RO）/ Y₂O₃Is 0.3 or less.

24. An optical glass according to any one of claims 1 to 3, characterised in that its components, expressed in weight percent, (Rn)₂O+RO）/ Y₂O₃Is 0.2 or less.

25. An optical glass according to any of claims 1 to 3, characterised in that its components, expressed in weight percent, (Rn)₂O+RO）/ Y₂O₃Is 0.1 or less.

26. An optical glass according to any one of claims 1 to 3, characterised in that it has the composition, expressed in weight percent, B₂O₃/（SiO₂+La₂O₃+Y₂O₃) 0.35 to 1.0.

27. An optical glass according to any one of claims 1 to 3, characterised in that it has the composition, expressed in weight percent, B₂O₃/（SiO₂+La₂O₃+Y₂O₃) 0.45 to 0.9.

28. An optical glass according to any one of claims 1 to 3, characterised in that it has the composition, expressed in weight percent, B₂O₃/（SiO₂+La₂O₃+Y₂O₃) 0.5 to 0.8.

29. An optical glass according to any one of claims 1 to 3, characterised in that its composition, expressed in weight percentage, is Gd₂O₃The content of (A) is 16-25%.

30. An optical glass according to any of claims 1 to 3, characterised in that it contains no F and/or no WO in its composition₃And/or TiO-free₂And/or RO-free, and/or Rn-free₂O, and/or does not contain Ta₂O₅And/or does not contain Al₂O₃The RO is one or more of MgO, CaO, SrO and BaO, and Rn₂O is Li₂O、Na₂O、K₂One or more of O.

31. An optical glass according to any one of claims 1 to 3, characterised in that its composition, expressed in weight percent, is SiO₂、B₂O₃、La₂O₃、Gd₂O₃、Y₂O₃And ZrO₂The total content of (A) is 95% or more.

32. An optical glass according to any one of claims 1 to 3, characterised in that its composition, expressed in weight percent, is SiO₂、B₂O₃、La₂O₃、Gd₂O₃、Y₂O₃And ZrO₂The total content of (B) is 97% or more.

33. An optical glass according to any one of claims 1 to 3, characterised in that its composition, expressed in weight percent, is SiO₂、B₂O₃、La₂O₃、Gd₂O₃、Y₂O₃、ZrO₂ZnO and Sb₂O₃The total content of (A) is 99% or more.

34. An optical glass according to claim 3, wherein the optical glass has a refractive index nd of 1.70 to 1.80; the Abbe number vd is 48-58.

35. An optical glass according to any one of claims 1 to 3, wherein the optical glass has a refractive index nd of 1.72 to 1.79; the Abbe number vd is 49-56.

36. An optical glass according to any one of claims 1 to 3, wherein the optical glass has a refractive index nd of 1.73 to 1.78; the Abbe number vd is 50-55.

37. An optical glass according to any one of claims 1 to 3, wherein the optical glass has a refractive index nd of 1.74 to 1.77; the Abbe number vd is 51-54.

38. An optical glass according to any one of claims 1 to 3, wherein the optical glass has a water-resistant stability D_WIs more than 2 types; and/or Knoop hardness H_KIs 700 x 10⁷Pa is above; and/or a density rho of 4.60g/cm³The following; and/or coefficient of thermal expansion alpha_-30/70℃Is 80X 10^-7below/K; and/or lambda₈₀Less than or equal to 400 nm; and/or lambda₅Less than or equal to 310 nm.

39. An optical glass according to any one of claims 1 to 3, wherein the optical glass has a water-resistant stability D_WIs of type 1; and/or Knoop hardness H_KIs 710 × 10⁷Pa is above; and/or a density p of 4.50g/cm³The following; and/or coefficient of thermal expansion alpha_-30/70℃Is 70X 10^-7below/K; and/or lambda₈₀Less than or equal to 390 nm;and/or lambda₅Less than or equal to 300 nm.

40. An optical glass according to any one of claims 1 to 3, characterized in that the optical glass has a Knoop hardness H_KIs 720X 10⁷Pa is above; and/or a density rho of 4.45g/cm³The following; and/or coefficient of thermal expansion alpha_-30/70℃Is 65X 10^-7below/K; and/or lambda₈₀Less than or equal to 385 nm; and/or lambda₅Less than or equal to 295 nm.

41. An optical glass according to any one of claims 1 to 3, wherein the Knoop hardness H of the optical glass_KIs 725X 10⁷Pa or above.

42. A glass preform made of the optical glass according to any one of claims 1 to 41.

43. An optical element produced from the optical glass according to any one of claims 1 to 41 or the glass preform according to claim 42.

44. An optical device comprising the optical glass according to any one of claims 1 to 41 or the optical element according to claim 43.