CN113415991A

CN113415991A - Optical glass and optical element

Info

Publication number: CN113415991A
Application number: CN202110857806.2A
Authority: CN
Inventors: 蔡冬雪
Original assignee: CDGM Glass Co Ltd
Current assignee: CDGM Glass Co Ltd
Priority date: 2021-07-28
Filing date: 2021-07-28
Publication date: 2021-09-21

Abstract

The invention provides an optical glass, which comprises the following components in percentage by mole: SiO 2₂：10～30％；B₂O₃：40～60％；Al₂O₃：5～20％；La₂O₃：5～20％；Y₂O₃: 1 to 15% of (SiO)₂+Al₂O₃)/B₂O₃0.3 to 1.1. Through reasonable component design, the optical glass obtained by the invention has excellent chemical stability and higher hardness while having the expected refractive index and Abbe number.

Description

Optical glass and optical element

Technical Field

The invention relates to optical glass, in particular to optical glass with a refractive index of 1.65-1.70 and an Abbe number of 51-59.

Background

In recent years, with the development of digital camera devices, image pickup devices, projection devices, and in-vehicle devices, etc., the demand for optical elements has been increasing, and development and production of optical glasses with higher performance have been demanded. In the optical glass for manufacturing optical elements, the market demand for medium refractive index low dispersion optical glass, which can correct chromatic aberration and miniaturize an optical system, and has a refractive index of 1.65 to 1.70 and an abbe number of 51 to 59, is increasing. Since monitoring cameras, vehicle-mounted cameras and the like, which are in increasing demand in recent years, are often used outdoors, existing glass imaging elements are often exposed to weather or sand and dust environments, and in the case of long-term use, glass is required to have excellent chemical stability and high hardness to improve the service life of monitoring equipment and vehicle-mounted equipment.

Disclosure of Invention

The invention aims to provide optical glass with excellent chemical stability and high hardness.

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

optical glass, the components of which, expressed in molar percentages, contain: SiO 2₂：10～30％；B₂O₃：40～60％；Al₂O₃：5～20％；La₂O₃：5～20％；Y₂O₃: 1 to 15% of (SiO)₂+Al₂O₃)/B₂O₃0.3 to 1.1.

Further, the optical glass comprises the following components in percentage by mole: gd (Gd)₂O₃: 0 to 10 percent; and/or MgO: 0 to 10 percent; and/or CaO: 0 to 10 percent; and/or SrO: 0 to 10 percent; and/or BaO: 0 to 10 percent; and/or Zr0₂: 0 to 5 percent; and/or Ta₂O₅: 0 to 5 percent; and/or Nb₂O₅: 0 to 5 percent; and/or ZnO: 0 to 10 percent; and/or Rn₂0: 0 to 10 percent; and/or a clarifying agent: 0 to 1%, of the total amount of Rn₂0 is Li₂O、Na₂O、K₂One or more of O and Sb as clarifier₂O₃、SnO₂SnO and CeO₂One or more of (a).

Optical glass, the composition of which, expressed in mole percent, is represented by SiO₂：10～30％；B₂O₃：40～60％；Al₂O₃：5～20％；La₂O₃：5～20％；Y₂O₃：1～15％；Gd₂O₃：0～10％；MgO：0～10％；CaO：0～10％；SrO：0～10％；BaO：0～10％；Zr0₂：0～5％；Ta₂O₅：0～5％；Nb₂O₅：0～5％；ZnO：0～10％；Rn₂0: 0 to 10 percent; a clarifying agent: 0 to 1% of a component of (SiO)₂+Al₂O₃)/B₂O₃0.3 to 1.1, the Rn₂0 is Li₂O、Na₂O、K₂One or more of O and Sb as clarifier₂O₃、SnO₂SnO and CeO₂One or more of (a).

Further, the optical glass has the components expressed by mole percent, and satisfies more than one of the following 5 conditions:

1)(SiO₂+Al₂O₃)/B₂O₃0.4 to 1.0;

2)Al₂O₃/Ln₂O₃0.3 to 1.5;

3)Ln₂O₃the/RO is more than 2.0;

4) RO is 0-15%;

5)Ln₂O₃8 to 30%, wherein RO is the total content of MgO, CaO, SrO and BaO, Ln₂O₃Is La₂O₃、Y₂O₃And Gd₂O₃The total content of (a).

Further, the optical glass comprises the following components in mol percentage: SiO 2₂: 12-25%; and/or B₂O₃: 42-55%; and/or Al₂O₃: 7-18%; and/or La₂O₃: 8-18%; and/or Y₂O₃: 2-12%; and/or Gd₂O₃: 0 to 5 percent; and/or MgO: 0-8%; and/or CaO: 0-8%; and/or SrO: 0-8%; and/or BaO: 0-8%; and/or Zr0₂: 0 to 3 percent; and/or Ta₂O₅: 0 to 3 percent; and/or Nb₂O₅: 0 to 3 percent; and/or ZnO: 0 to 5 percent; and/or Rn₂0: 0 to 5 percent; and/or a clarifying agent: 0 to 0.5%, the Rn₂0 is Li₂O、Na₂O、K₂One or more of O and Sb as clarifier₂O₃、SnO₂SnO and CeO₂One or more of (a).

1)(SiO₂+Al₂O₃)/B₂O₃0.5 to 0.8;

2)Al₂O₃/Ln₂O₃0.4 to 1.2;

3)Ln₂O₃the/RO is more than 3.0;

4) RO is 0-10%;

5)Ln₂O₃10 to 26% of a total amount of RO, Ln, MgO, CaO, SrO and BaO₂O₃Is La₂O₃、Y₂O₃And Gd₂O₃The total content of (a).

Further, the optical glass comprises the following components in mol percentage: SiO 2₂: 15-22%; and/or B₂O₃: 45-52 percent; and/or Al₂O₃: 8-15%; and/or La₂O₃: 10-16%; and/or Y₂O₃: 3-10%; and/or Gd₂O₃: 0-2%; and/or MgO: 0-6%; and/or CaO: 0-6%; and/or SrO: 0-6%; and/or BaO: 0-6%; and/or Zr0₂: 0 to 1 percent; and/or Ta₂O₅: 0 to 1 percent; and/or Nb₂O₅: 0 to 1 percent; and/or ZnO: 0 to 1 percent; and/or Rn₂0: 0-2%; and/or a clarifying agent: 0 to 0.1%, the Rn₂0 is Li₂O、Na₂O、K₂One or more of O and Sb as clarifier₂O₃、SnO₂SnO and CeO₂One or more of (a).

Further, the optical glass has the components expressed by mole percent, and satisfies more than one of the following 4 conditions:

1)Al₂O₃/Ln₂O₃0.5 to 0.8;

2)Ln₂O₃the/RO is more than 4.0;

3) RO is 0-8%;

4)Ln₂O₃15 to 22%, wherein RO is the total content of MgO, CaO, SrO and BaO, Ln₂O₃Is La₂O₃、Y₂O₃And Gd₂O₃The total content of (a).

Further, the refractive index n of the optical glass_d1.65 to 1.70, preferably a refractive index n_d1.66 to 1.69, and more preferably a refractive index n_dIs 1.67 to 1.68, and has an Abbe number v_d51 to 59, preferably Abbe number v_dIs 52 to 58, and the Abbe number v is more preferable_dIs 53 to 57.

Further, the stability of the optical glass against water action D_WIs 2 or more, preferably 1; and/or stability against acid action D_AIs 4 or more, preferably 3 or more; and/or Knoop hardness H_KIs 650 x 10⁷Pa or more, preferably 670X 10⁷Pa is above; and/or a density p of 3.70g/cm³Hereinafter, it is preferably 3.60g/cm³The following.

The glass preform is made of the optical glass.

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

An optical device comprising the above optical glass and/or comprising the above optical element.

The invention has the beneficial effects that: through reasonable component design, the optical glass obtained by the invention has excellent chemical stability and higher hardness while having the expected refractive index and Abbe number.

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. Note that, although the description of the duplicate description may be appropriately omitted, the gist of the invention is not limited to this. In the following, the optical glass of the present invention is sometimes simply referred to as glass.

[ optical glass ]

The ranges of the respective components (components) of the optical glass of the present invention are explained below. In the present invention, unless otherwise specified, the contents and total contents of the respective components are all expressed in terms of mole percent (mol%), that is, the contents and total contents of the respective components are expressed in terms of mole percent relative to the total amount of glass matter converted into the composition of oxides. Here, the term "composition in terms of 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 into oxides, the total molar 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 >

SiO₂Is an essential component of the present invention by containing more than 10% SiO₂To improve the processability and chemical stability of the glass. Thus, SiO₂The content of (b) is 10% or more, preferably 12% or more, more preferably 15% or more. On the other hand, by mixing SiO₂The content of (b) is limited to 30% or less, and a larger refractive index can be easily obtained, and deterioration of glass meltability and excessive increase in viscosity can be suppressed. Thus, SiO₂The content of (b) is 30% or less, preferably 25% or less, more preferably 22% or less.

B₂O₃Is an essential component of the present invention, by containing more than 40% of B₂O₃This has the effect of improving the meltability of glass and resistance to devitrification. Thus, B₂O₃The content of (b) is 40% or more, preferably 42% or more, and more preferably 45% or more. On the other hand, by mixing B₂O₃The content of (b) is limited to 60% or less, and deterioration of chemical stability of the glass can be suppressed. Thus, B₂O₃The content of (b) is 60% or less, preferably 55% or less, more preferably 52% or less.

Al₂O₃Is an essential component of the present invention, has the effect of improving processability, resistance to devitrification and chemical stability, and Al in the present invention₂O₃The content of the component (B) is 5% or more, preferably 7% or more, more preferably 8% or more. Particularly, the SiO content is more than 15%₂When the component (C) is contained, 8% or more of Al is added₂O₃Can inhibit SiO₂The devitrification due to the component (B) gives a glass excellent in devitrification resistance. On the other hand, by mixing Al₂O₃The content of the component is limited to 20% or less, and excessive Al content can be prevented₂O₃Deterioration of resistance to devitrification and reduction of refractive index due to the component. Thus, Al₂O₃The content of the component (B) is 20% or less, preferably 18% or less, more preferably 15% or less.

In some embodiments of the invention, the composition is prepared by reacting (SiO)₂+Al₂O₃)/B₂O₃The value of (A) is limited to more than 0.3, so that the chemical stability and hardness of the glass can be improved; on the other hand, by mixing (SiO)₂+Al₂O₃)/B₂O₃The limit of 1.1 or less improves the glass processability, and suppresses the deterioration of the melting property of the glass raw material and the excessive increase of the viscosity. Therefore, (SiO) is preferable₂+Al₂O₃)/B₂O₃0.3 to 1.1, more preferably (SiO)₂+Al₂O₃)/B₂O₃0.4 to 1.0, and more preferably (SiO)₂+Al₂O₃)/B₂O₃0.5 to 0.8.

La₂O₃Has the effect of improving the refractive index and Abbe number of the glass, and contains more than 5% of La₂O₃To obtain the above effects, La is preferable₂O₃The content of (A) is 8% or more, more preferably La₂O₃The content of (A) is more than 10%. On the other hand, by mixing La₂O₃The content of (2) is limited to 20% or less, and the stability of the glass can be prevented from being lowered. Thus, La₂O₃The content of (A) is 20% or less, preferably 18% or less, more preferably 16% or less。

Will Y₂O₃The content of (b) is limited to 1% or more, and the specific gravity of the glass can be reduced compared with other rare earth components while suppressing the increase in the material cost of the glass while maintaining a high refractive index and a high Abbe number. On the other hand, by mixing Y₂O₃The content of the component (A) is limited to 15% or less, and the devitrification resistance and the chemical stability of the glass can be prevented from being lowered. Thus, Y₂O₃The content of the component (A) is 1 to 15%, preferably 2 to 12%, more preferably 3 to 10%.

Gd₂O₃The refractive index and Abbe number of the glass may be increased, in some embodiments of the invention, by the incorporation of Gd₂O₃The content of (B) is limited to 10% or less, and the increase of the specific gravity of the glass can be suppressed. Thus, Gd₂O₃The content of (b) is 10% or less, preferably 5% or less, more preferably 2% or less.

In some embodiments of the invention, the La is prepared by subjecting La₂O₃、Y₂O₃And Gd₂O₃Total content Ln of₂O₃By controlling the refractive index and Abbe number of the glass to 8% or more, the refractive index and Abbe number of the glass can be increased, and the glass having a desired refractive index and Abbe number can be easily obtained. Thus, Ln₂O₃Preferably 8% or more, more preferably 10% or more, and still more preferably 15% or more. On the other hand, by mixing Ln₂O₃The content of (b) is limited to 30% or less, and the liquid phase temperature of the glass can be lowered to prevent devitrification of the glass and improve the chemical stability of the glass. Thus, Ln₂O₃The content of (b) is preferably 30% or less, more preferably 26% or less, and further preferably 22% or less.

In some embodiments, Al is added₂O₃/Ln₂O₃The chemical stability and hardness of the glass are improved by controlling the content of the glass to be more than 0.3; on the other hand, by mixing Al₂O₃/Ln₂O₃The glass processability can be improved by limiting the glass to 1.5 or less. Therefore, Al is preferable₂O₃/Ln₂O₃0.3 to 1.5, furtherPreferably Al₂O₃/Ln₂O₃0.4 to 1.2, and further preferably Al₂O₃/Ln₂O₃0.5 to 0.8.

MgO can improve the low-temperature melting property of the glass, and by setting the content of MgO to 10% or less, deterioration in chemical stability due to the inclusion of an excessive MgO component can be suppressed. Therefore, the content of the MgO component is 10% or less, preferably 8% or less, and more preferably 6% or less.

While CaO can improve the low-temperature fusibility of the glass, limiting the content of CaO to 10% or less can suppress deterioration of chemical stability due to the excessive content of CaO component. Therefore, the content of the CaO component is 10% or less, preferably 8% or less, and more preferably 6% or less.

SrO can improve the low-temperature melting property of the glass, and on the other hand, by limiting the content of the SrO component to 10% or less, deterioration in chemical stability due to the excessive SrO component can be suppressed. Therefore, the content of the SrO component is 10% or less, preferably 8% or less, and more preferably 6% or less.

BaO can improve the low-temperature melting property of the glass, and on the other hand, by limiting the content of the BaO component to 10% or less, deterioration of chemical stability due to the excessive BaO component can be suppressed. Therefore, the content of the BaO component is 10% or less, preferably 8% or less, and more preferably 6% or less.

In some embodiments of the present invention, by limiting the total content R0 of MgO, CaO, SrO, and BaO to 15% or less, deterioration in chemical stability of the glass due to the excessive content of R0 can be suppressed. Therefore, the content of R0 is preferably 15% or less, more preferably 10% or less, and still more preferably 8% or less.

In some embodiments, by mixing Ln₂O₃the/RO is controlled to be more than 2.0, and the chemical stability of the glass can be improved. Therefore, Ln is preferable₂O₃The ratio of/RO is 2.0 or more, and Ln is more preferable₂O₃The ratio of/RO is 3.0 or more, and Ln is more preferable₂O₃The ratio of/RO is 4.0 or more.

Zr0₂The refractive index and Abbe number of the glass can be improved, and the processability of the glass can be improved. On the other hand, by adding Zr0₂The content of (3) is limited to 5% or less, and the content of excess Zr0 can be reduced₂Resulting in devitrification of the glass. Thus, Zr0₂The content of (b) is 5% or less, preferably 3% or less, more preferably 1% or less.

Ta₂O₅Can improve the refractive index and the anti-devitrification performance of the glass. On the other hand, by using expensive Ta₂O₅The composition is limited to 5% or less, and the raw material cost of the glass can be reduced. Thus, Ta₂O₅The content of (b) is 5% or less, preferably 3% or less, more preferably 1% or less. Ta may not be contained from the viewpoint of cost reduction₂O₅。

Nb₂O₅Can increase the refractive index of the glass by adding Nb₂O₅The content of (B) is limited to 5% or less, and the content of excess Nb can be reduced₂O₅Devitrification due to the component(s) and a decrease in the transmittance of the glass to visible light (particularly, a wavelength of 500nm or less) can be suppressed. Thus, Nb₂O₅The content of (b) is 5% or less, preferably 3% or less, more preferably 1% or less.

While ZnO can improve the low-temperature melting property of the glass, by limiting the content of ZnO to 10% or less, the decrease in abbe number caused by the excessive content of ZnO can be suppressed. Therefore, the ZnO content is 10% or less, preferably 5% or less, and more preferably 1% or less.

Rn₂0(Rn₂0 is Li₂O、Na₂O、K₂One or more kinds of O) can adjust the refractive index of the glass and improve the meltability of the glass. By mixing Rn₂The content of 0 is controlled to 10% or less, and excess Rn due to the inclusion can be suppressed₂0 component, and deterioration of chemical stability. Thus, Rn₂The content of 0 is 10% or less, preferably 5% or less, and more preferably 2% or less.

Clarifying with 0-1%The agent can improve the clarification effect of glass, and Sb can be adopted in the invention₂O₃、SnO₂SnO and CeO₂As a clarifying agent. However, the present invention has a reasonable formulation design, and therefore, the present invention preferably contains 0 to 0.5% of a clarifying agent, more preferably 0 to 0.1% of a clarifying agent, and even more preferably no clarifying agent, because of its excellent clarifying effect and excellent air bubble degree.

< 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.

"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 1.66, more preferably 1.67. In some embodiments, the refractive index (n) of the optical glass of the present invention_d) The upper limit of (a) is 1.70, preferably the upper limit is 1.69, and more preferably the upper limit is 1.68.

In some embodiments, the Abbe number (v) of the optical glass of the present invention_d) The lower limit of (2) is 51, preferably 52, and more preferably 53. In some embodiments, the Abbe number (v) of the optical glass of the present invention_d) The upper limit of (3) is 59, preferably 58, more preferably 57.

< 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.

< stability against acid Effect >

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

In some embodiments, the stability to acid action of the optical glasses of the invention (D)_A) Is in 4 or more types, preferably 3 or more typesThe above.

< Knoop hardness >

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

In some embodiments, the Knoop hardness (H) of the optical glasses of the present invention_K) Is 650 x 10⁷Pa or more, preferably 670X 10⁷Pa or above.

< Density >

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

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

[ method for producing optical glass ]

The method for manufacturing the optical glass comprises the following steps: the glass of the invention can be produced by adopting conventional raw materials and processes, including but not limited to using carbonate, nitrate, sulfate, hydroxide, oxide, fluoride and the like as raw materials, mixing the raw materials according to a conventional method, putting the mixed furnace charge into a smelting furnace (such as a platinum or platinum alloy crucible) at 1250-1350 ℃ for smelting, obtaining homogeneous molten glass without bubbles and undissolved substances after clarification and homogenization, casting the molten glass in a mould and annealing.

The glass of the invention can also be produced by adopting a secondary smelting mode, namely, the mixture of the raw materials is firstly put into a quartz, alumina or zirconium crucible for smelting, the clinker is prepared after the smelting is finished, and then the clinker is put into a platinum or platinum alloy crucible for smelting, so that the required high-quality glass is obtained.

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 of the present invention and the optical element are each formed of the above-described optical glass of the present invention. The glass prefabricated member of the invention has the characteristics of medium refractive index and low dispersion; various optical elements such as lenses and prisms having high optical values can be provided. By having such an intermediate refractive index, a large amount of light refraction can be obtained even when the optical element is thinned. Further, by having such low dispersion, it is possible to reduce the deviation of focus (chromatic aberration) due to the wavelength of light when used as a single lens. Therefore, the optical glass of the present invention is useful in optical design, and particularly in the case of constituting an optical system, it is possible to realize miniaturization of the optical system while realizing high imaging characteristics and the like, and it is possible to expand the degree of freedom in optical design.

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.

Further, since the prism has a relatively high refractive index, by combining the prism with an imaging optical system and bending the optical path to direct the prism in a desired direction, a compact and wide-angle optical system can be realized.

[ 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. The optical glass has excellent chemical stability, and is particularly suitable for being applied to the fields of vehicle-mounted monitoring, security protection and the like.

In order to further understand the technical solution of the present invention, examples of the optical glass of the present invention will be described below. It should be noted that these examples do not limit the scope of the present invention.

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 2 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 1 to 2. In the following table (SiO)₂+Al₂O₃)/B₂O₃Is denoted by K1; ln₂O₃Is denoted by K2; al (Al)₂O₃/Ln₂O₃Is denoted by K3; the value of RO is denoted by K4; ln₂O₃The value of/RO is denoted K5.

TABLE 1

TABLE 2

< glass preform example >

Various lenses such as a concave meniscus lens, a convex meniscus lens, a biconvex lens, a biconcave lens, a plano-convex lens and a plano-concave lens, and preforms such as prisms were produced from the glasses obtained in examples 1 to 20 of optical glass by means of polishing or press molding such as reheat press molding and precision press molding.

< optical element example >

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

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

< optical Instrument example >

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

Claims

1. Optical glass, characterized in that its components, expressed in molar percentages, contain: SiO 2₂：10～30％；B₂O₃：40～60％；Al₂O₃：5～20％；La₂O₃：5～20％；Y₂O₃: 1 to 15% of (SiO)₂+Al₂O₃)/B₂O₃0.3 to 1.1.

2. An optical glass according to claim 1, characterised in that its composition, expressed in mole percentages, further comprises: gd (Gd)₂O₃: 0 to 10 percent; and/or MgO: 0 to 10 percent; and/or CaO: 0 to 10 percent; and/or SrO: 0 to 10 percent; and/or BaO: 0 to 10 percent; and/or Zr0₂: 0 to 5 percent; and/or Ta₂O₅: 0 to 5 percent; and/or Nb₂O₅: 0 to 5 percent; and/or ZnO: 0 to 10 percent; and/or Rn₂0: 0 to 10 percent; and/or a clarifying agent: 0 to 1%, of the total amount of Rn₂0 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 composition, expressed in mole percentage, is represented by SiO₂：10～30％；B₂O₃：40～60％；Al₂O₃：5～20％；La₂O₃：5～20％；Y₂O₃：1～15％；Gd₂O₃：0～10％；MgO：0～10％；CaO：0～10％；SrO：0～10％；BaO：0～10％；Zr0₂：0～5％；Ta₂O₅：0～5％；Nb₂O₅：0～5％；ZnO：0～10％；Rn₂0: 0 to 10 percent; a clarifying agent: 0 to 1% of a component of (SiO)₂+Al₂O₃)/B₂O₃0.3 to 1.1, the Rn₂0 is Li₂O、Na₂O、K₂One or more of O and Sb as clarifier₂O₃、SnO₂SnO and CeO₂One or more of (a).

4. An optical glass according to any one of claims 1 to 3, wherein the composition, expressed in mole percent, satisfies one or more of the following 5 conditions:

1)(SiO₂+Al₂O₃)/B₂O₃0.4 to 1.0;

2)Al₂O₃/Ln₂O₃0.3 to 1.5;

3)Ln₂O₃the/RO is more than 2.0;

4) RO is 0-15%;

5. An optical glass according to any one of claims 1 to 3, characterised in that its components, expressed in mole percentages, are: SiO 2₂: 12-25%; and/or B₂O₃: 42-55%; and/or Al₂O₃: 7-18%; and/or La₂O₃: 8-18%; and/or Y₂O₃: 2-12%; and/or Gd₂O₃: 0 to 5 percent; and/orMgO: 0-8%; and/or CaO: 0-8%; and/or SrO: 0-8%; and/or BaO: 0-8%; and/or Zr0₂: 0 to 3 percent; and/or Ta₂O₅: 0 to 3 percent; and/or Nb₂O₅: 0 to 3 percent; and/or ZnO: 0 to 5 percent; and/or Rn₂0: 0 to 5 percent; and/or a clarifying agent: 0 to 0.5%, the Rn₂0 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, expressed in mole percent, satisfies one or more of the following 5 conditions:

1)(SiO₂+Al₂O₃)/B₂O₃0.5 to 0.8;

2)Al₂O₃/Ln₂O₃0.4 to 1.2;

3)Ln₂O₃the/RO is more than 3.0;

4) RO is 0-10%;

7. An optical glass according to any one of claims 1 to 3, characterised in that its components, expressed in mole percentages, are: SiO 2₂: 15-22%; and/or B₂O₃: 45-52 percent; and/or Al₂O₃: 8-15%; and/or La₂O₃: 10-16%; and/or Y₂O₃: 3-10%; and/or Gd₂O₃: 0-2%; and/or MgO: 0-6%; and/or CaO: 0-6%; and/or SrO: 0-6%; and/or BaO: 0-6%; and/or Zr0₂: 0 to 1 percent; and/or Ta₂O₅: 0 to 1 percent; and/or Nb₂O₅: 0 to 1 percent; and/or ZnO: 0 to 1 percent; and/or Rn₂0: 0-2%; and/or a clarifying agent: 0 to 0.1%, the Rn₂0 is Li₂O、Na₂O、K₂One or more of O and Sb as clarifier₂O₃、SnO₂SnO and CeO₂One or more of (a).

8. An optical glass according to any one of claims 1 to 3, characterised in that its composition, expressed in mole percentage, satisfies one or more of the following 4 conditions:

1)Al₂O₃/Ln₂O₃0.5 to 0.8;

2)Ln₂O₃the/RO is more than 4.0;

3) RO is 0-8%;

9. An optical glass according to any one of claims 1 to 3, wherein the refractive index n of the optical glass_d1.65 to 1.70, preferably a refractive index n_d1.66 to 1.69, and more preferably a refractive index n_dIs 1.67 to 1.68, and has an Abbe number v_d51 to 59, preferably Abbe number v_dIs 52 to 58, and the Abbe number v is more preferable_dIs 53 to 57.

10. The optical glass according to any one of claims 1 to 3, wherein the optical glass has a water-resistant stability D_WIs 2 or more, preferably 1; and/or stability against acid action D_AIs 4 or more, preferably 3 or more; and/or Knoop hardness H_KIs 650 x 10⁷Pa or more, preferably 670X 10⁷Pa is above; and/or a density p of 3.70g/cm³Hereinafter, it is preferably 3.60g/cm³The following.

11. A glass preform characterized by being made of the optical glass according to any one of claims 1 to 10.

12. An optical element produced from the optical glass according to any one of claims 1 to 10 or the glass preform according to claim 11.

13. An optical device comprising the optical glass according to any one of claims 1 to 10 and/or comprising the optical element according to claim 12.