CN110963701A

CN110963701A - Optical glass, glass preform, optical element and optical instrument

Info

Publication number: CN110963701A
Application number: CN201911346197.3A
Authority: CN
Inventors: 毛露路; 郝良振; 何波; 匡波
Original assignee: CDGM Glass Co Ltd
Current assignee: CDGM Glass Co Ltd
Priority date: 2019-12-24
Filing date: 2019-12-24
Publication date: 2020-04-07
Also published as: CN115072990A

Abstract

The invention provides optical glass with a refractive index of 1.65-1.79 and an Abbe number of 48-56, which comprises the following components in percentage by weight: SiO 2₂：10～30％、B₂O₃：5～20％、Al₂O₃：10～35％、La₂O₃：15～40％、Y₂O₃：10～45％、ZrO₂: 0.5-8%, MgO: 0.5 to 8% of Al₂O₃/SiO₂0.4 to 2.0. Through reasonable component design, the optical glass obtained by the invention has higher hardness and excellent chemical stability while having expected refractive index, Abbe number and refractive index temperature coefficient, and is suitable for being used in the fields of vehicle-mounted monitoring and security protection and the like.

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 1.65-1.79 and an Abbe number of 48-56, and a glass prefabricated member, an optical element and an optical instrument which are made of the optical glass.

Background

The lanthanum-containing optical glass with the refractive index of 1.65-1.79 and the Abbe number of 48-56 belongs to lanthanum crown glass, has the advantages of high refractive index and low dispersion compared with common crown glass, and can greatly improve the field angle of a lens and improve the imaging quality when being applied to an optical imaging system.

With the development of intelligent driving technology, intelligent security technology and environment perception technology, the lens in the field needs to work in severe environments such as sand storm, acid rain, high-low temperature alternation and the like for a long time and keeps extremely high reliability, which puts forward a new requirement on the environmental stability of the lens material, different from the traditional lens (such as a single lens reflex) working in a better environment. Taking a vehicle-mounted lens as an example, the requirement of large field of view and high definition requires that the material has the characteristics of high refractive index and low dispersion. More importantly, the vehicle-mounted lens is related to personal safety, the design service life of the vehicle-mounted lens is consistent with the service life of a vehicle, more than 15 years are needed, and extremely high requirements are provided for the reliability of the vehicle-mounted lens.

When the vehicle-mounted lens is exposed to a severe working environment for a long time, the first lens is very easy to be rubbed by sandy soil at a high speed, the main component in the sandy soil is quartz microparticles which have very high hardness, such as the Knoop hardness of glass (hereinafter, H is used)_kExpressed) below 650 x 10⁷Pa, the glass is easily scratched, thereby reducing the imaging quality.

The vehicle-mounted lens also needs to have good acid resistance, such as resistance to acid rain, acid snow-melting agents and the like. At present, lanthanum crown glass is mainly composed of B₂O₃-La₂O₃The system composition, the acid resistance of the powder method can only reach 3 types or lower, and the powder method is easy to be corroded by acid substances when used under long-term severe conditions and is difficult to meet the use requirements of the vehicle-mounted field.

Because the refractive index of the glass material changes along with the temperature change, the performance is called the temperature coefficient of the refractive index of the glass, and if the temperature coefficient of the refractive index of the glass is too large, when the working temperature is greatly changed, such as a monitoring camera lens and a high-temperature furnace observation lens of an automobile driving to a tropical zone and a high-cold area in a cold zone, the lenses cannot be accurately focused, so that the definition is reduced. Therefore, the development of optical glass with a specific temperature coefficient of refractive index is required, which is a new subject for optical design and optical material research.

Disclosure of Invention

The invention aims to provide optical glass with expected refractive index, Abbe number and temperature coefficient of refractive index, high hardness and excellent chemical stability.

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

(1) the optical glass comprises the following components in percentage by weight: SiO 2₂：10～30％、B₂O₃：5～20％、Al₂O₃：10～35％、La₂O₃：15～40％、Y₂O₃：10～45％、ZrO₂: 0.5-8%, MgO: 0.5 to 8% of Al₂O₃/SiO₂0.4 to 2.0.

(2) The optical glass according to (1), which comprises the following components in percentage by weight: p₂O₅：0～5％、Gd₂O₃：0～10％、TiO₂：0～10％、Nb₂O₅：0～5％、ZnO：0～10％、CaO：0～8％、SrO+BaO：0～8％、Li₂O：0～4％、Na₂O：0～4％、K₂O: 0-4% of a clarifying agent: 0 to 2 percent.

(3) Optical glass containing SiO₂、B₂O₃、Al₂O₃、La₂O₃And Y₂O₃The components of which are expressed in weight percentage, wherein Al₂O₃/SiO₂0.4 to 2.0, La₂O₃/Y₂O₃0.5 to 2.1, the refractive index n of the optical glass_dIs 1.65-1.79, and has Abbe number v_dIs 48 to 56.

(4) The optical glass according to (3), which comprises the following components in percentage by weight: SiO 2₂：10～30％、B₂O₃：5～20％、Al₂O₃：10～35％、La₂O₃：15～40％、Y₂O₃：10～45％、ZrO₂：0.5～8％、MgO：0.5～8％、P₂O₅：0～5％、Gd₂O₃：0～10％、TiO₂：0～10％、Nb₂O₅：0～5％、ZnO：0～10％、CaO：0～8％、SrO+BaO：0～8％、Li₂O：0～4％、Na₂O：0～4％、K₂O: 0-4% of a clarifying agent: 0 to 2 percent.

(5) The optical glass according to any one of (1) to (4), wherein the composition is represented by weight percentage, wherein Al₂O₃/SiO₂0.5 to 1.8, preferably Al₂O₃/SiO₂0.7 to 1.4.

(6) The optical glass according to any one of (1) to (4), wherein the composition is represented by weight percentage, wherein Al₂O₃/B₂O₃0.5 to 4.0, preferably Al₂O₃/B₂O₃0.7 to 3.5, more preferably Al₂O₃/B₂O₃0.8 to 3.0.

(7) The optical glass according to any one of (1) to (4), wherein the composition is represented by weight percentage, wherein La₂O₃/Y₂O₃0.5 to 2.1, preferably La₂O₃/Y₂O₃0.6 to 1.9, more preferably La₂O₃/Y₂O₃0.7 to 1.7.

(8) The optical glass according to any one of (1) to (4), wherein the composition is, in terms of weight percentage, CaO/MgO in the range of 0 to 1.2, preferably CaO/MgO in the range of 0 to 1.0, and more preferably CaO/MgO in the range of 0 to 0.8.

(9) The optical glass according to any one of (1) to (4), wherein the composition is represented by weight percentage, wherein (Na)₂O+K₂O)/Li₂O is 0 to 1.1, preferably (Na)₂O+K₂O)/Li₂O is 0 to 1.0, more preferably (Na)₂O+K₂O)/Li₂O is 0 to 0.8.

(10) The optical glass according to any one of (1) to (4), which comprises, in terms of weight percent: SiO 2₂: 12-28%, and/or B₂O₃: 7 to 18%, and/or Al₂O₃: 12-30% and/or La₂O₃: 18 to 35%, and/or Y₂O₃: 13 to 40%, and/or ZrO₂: 0.5-6%, and/or MgO: 0.5 to 6%, and/or P₂O₅: 0 to 3%, and/or Gd₂O₃: 0 to 5%, and/or TiO₂: 0 to 5%, and/or Nb₂O₅: 0-3%, and/or ZnO: 0.5-8%, and/or CaO: 0-6%, and/or SrO + BaO: 0 to 4%, and/or Li₂O: 0 to 3%, and/or Na₂O: 0 to 3%, and/or K₂O: 0-3%, and/or a clarifying agent: 0 to 1 percent.

(11) The optical glass according to any one of (1) to (4), which comprises, in terms of weight percent: SiO 2₂: 14 to 25%, and/or B₂O₃: 9 to 16% and/or Al₂O₃: 14 to 22%, and/or La₂O₃: 20 to 30%, and/or Y₂O₃: 15 to 35%, and/or ZrO₂: 0.5-4%, and/or MgO: 0.5-4%, and/or ZnO: 0.5-5%, and/or CaO: 0 to 3%, and/or Li₂O: 0.1-2%, and/or a clarifying agent: 0 to 0.5 percent.

(12) The optical glass according to any one of (1) to (4), wherein P is not contained in the component₂O₅And/or does not contain Gd₂O₃And/or does not contain TiO₂And/or no Nb₂O₅And/or does not contain BaO, and/or does not contain SrO, and/or does not contain K₂O, and/or does not contain Na₂O。

(13) The optical glass according to any one of (1) to (4), wherein the refractive index n of the optical glass_d1.65 to 1.79, preferably 1.66 to 1.77; abbe number v_d48 to 56, preferably 50 to 54.

(14) The optical glass according to any one of (1) to (4), which has stability against acid action D_AIs more than 3 types, and preferably has acid resistance stability D_AIs more than 2 types; and/or a temperature coefficient of refractive index dn/dt of 10.0 x 10^-6A temperature coefficient of refractive index dn/dt of 9.0X 10 is preferably not more than/° C^-6A temperature coefficient of refractive index dn/dt of 8.5X 10 or less^-6Less than/° c, and more preferably, the temperature coefficient of refractive index dn/dt is 8.0 as a component10^-6Below/° c; and/or lambda₈₀Is less than or equal to 405nm, preferably lambda₈₀Is less than or equal to 400nm, more preferably lambda₈₀Is less than or equal to 395 nm; and/or Knoop hardness H_KIs 680 x 10⁷Pa or more, preferably Knoop hardness H_KIs 685 × 10⁷Pa or more, more preferably Knoop hardness H_KIs 690X 10⁷Pa or more, and/or a coefficient of thermal expansion α_100/300℃Is 75X 10^-7below/K, the thermal expansion coefficient is preferably α_100/300℃Is 73X 10^-7A thermal expansion coefficient of α or less is more preferable_100/300℃Is 70X 10^-7and/K is less than or equal to.

(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 produced using the optical glass of any one of (1) to (14) or the optical element of (16).

The invention has the beneficial effects that: through reasonable component design, the optical glass obtained by the invention has higher hardness and excellent chemical stability while having expected refractive index, Abbe number and refractive index temperature coefficient, and is suitable for being used in the fields of vehicle-mounted monitoring and security protection and the like.

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. The optical glass of the present invention may be simply referred to as glass in the following.

[ optical glass ]

The ranges of the respective components of the optical glass of the present invention are explained below. In the present specification, the 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, 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 (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. The term "and/or" as used herein is inclusive, e.g., "a; and/or B "means A alone, B alone, or both A and B.

< essential Components and optional Components >

The skeleton of the optical glass is mainly made of SiO₂、B₂O₃、P₂O₅And the like.

SiO₂The formed glass skeleton is compact, can improve the stability of acid resistance of glass, and is combined with B₂O₃、P₂O₅In comparison with the other two network forming oxides, SiO₂The refractive index of (2) is low and the dispersion is large. If SiO₂In excess of 30%, the refractive index and dispersion of the glass may be lower than the design requirements, while also presenting a risk of being difficult to melt; if the content is less than 10%, the stability of the glass against acid action is drastically deteriorated. On the other hand, since the glass of the present invention contains a large amount of rare earth metal oxide and risks rapid deterioration of devitrification resistance of the glass, SiO is used for balancing the refractive index, dispersion, stability of acid resistance and resistance to devitrification of the optical glass of the present invention₂The content of (b) is limited to 10 to 30%, preferably 12 to 28%, more preferably 14 to 25%.

B₂O₃The glass can be added into the glass of the invention to improve the refractive index of the glass and reduce the dispersion of the glass. However, if the content exceeds 20%, the following problems are caused to the glass of the present invention: 1) the acid resistance of the glass decreases sharply. The inventor finds out through a great deal of research that the inventionThe glass system has low alkali metal content and high Al content₂O₃If B is₂O₃The content of (b) exceeds 20%, and the structure thereof rapidly changes abruptly in the direction of porosity, thereby causing a sharp decrease in acid resistance of the glass. 2) If the glass according to the invention is to be strengthened further by means of chemical strengthening (ion exchange), B₂O₃The increase of the content will hinder the ion exchange on the surface of the glass, thereby reducing the chemical strengthening effect, and if the content exceeds 20%, the glass is difficult to increase the strength by the chemical strengthening method. 3) B is₂O₃The higher the content of (A), the stronger the ability to corrode the refractory material, more impurity elements are brought in during the production process, and the transmittance of the product is reduced. Thus, in the present invention B₂O₃The upper limit of the content of (B) is 20%, preferably 18%, more preferably 16%. On the other hand, B₂O₃When the content of (B) is less than 5%, the dispersion of the glass is higher than the design requirement, and the glass is particularly liable to devitrify, resulting in deterioration of the melting property of the glass raw material. Thus, B₂O₃The lower limit of (B) is 5%, the lower limit is preferably 7%, and the lower limit is more preferably 9%.

Proper amount of P₂O₅The glass dispersion can be reduced and the chemical strengthening performance of the glass can be improved when the glass is added into the glass, but if the content of the glass exceeds 5 percent, the glass has serious ceramization tendency, the volatilization amount is increased in the smelting process, and the controllability of key indexes such as refractive index, dispersion and the like is reduced. Thus, P₂O₅The content of (B) is limited to 5% or less, preferably 3% or less, and more preferably no P is added₂O₅。

Al₂O₃Is the main component of the glass of the invention, the content of which added to the glass is SiO₂、B₂O₃And alkali metal oxides (e.g., Li)₂O、Na₂O、K₂O, etc.) and the like. The inventors have found that Al changes when other components of the glass are changed₂O₃The effect therein also changes. Specifically, 1) when the content of the alkali metal oxide is less than 2%, Al₂O₃Is added in a maximum amount up to35 percent, greatly improves the acid resistance of the glass, simultaneously quickly reduces the thermal expansion coefficient of the glass, and obviously improves the thermal shock resistance; if the content is more than 35%, the melting property of the glass is rapidly deteriorated, and a large amount of infusible matter appears in the glass even if an extremely high melting temperature is used. 2) When the content of the alkali metal oxide is more than 2%, the chemical strengthening property of the glass is enhanced, but it is required to control Al₂O₃Below 30%, otherwise the glass raw material becomes extremely refractory. 3) If Al is present₂O₃The content of (b) is less than 10%, the acid resistance of the glass is rapidly reduced, and the thermal expansion coefficient of the glass is rapidly increased, so that the thermal shock resistance of the glass is greatly reduced. Thus, Al₂O₃The content of (B) is 10 to 35%, preferably 12 to 30%, more preferably 14 to 22% in the present invention.

In the present glass system, Al₂O₃Content of (D) and SiO₂、B₂O₃The content of (A) is closely related to the content of (B) because of Al³ ⁺Ions in the glass structure will follow SiO₂、B₂O₃The content change of (a) produces a structural change, thereby affecting the refractive index, acid resistance and thermal shock resistance of the glass. When Al is present₂O₃/B₂O₃When the value of (b) is less than 0.5, the dispersion of the glass is higher than the design requirement, and the acid resistance of the glass is rapidly reduced; if Al is present₂O₃/B₂O₃When the value of (b) is more than 4.0, the thermal expansion coefficient of the glass stops decreasing and the glass material becomes extremely refractory. Thus, Al₂O₃/B₂O₃The value of (b) is 0.5 to 4.0, preferably 0.7 to 3.5, and more preferably 0.8 to 3.0.

When Al is present₂O₃/SiO₂When the value of (b) is higher than 2.0, the hardness and acid resistance of the glass stop rising rapidly and tend to decrease, while the glass becomes extremely refractory and the transmittance remarkably decreases; when Al is present₂O₃/SiO₂When the value of (A) is less than 0.4, the temperature coefficient of the glass refractive index rapidly rises, failing to meet the design requirements. Thus, Al₂O₃/SiO₂Has a value of 0.4 to 2.0, preferably 0.5 to 1.8, more preferably 0.7 to E1.4。

The traditional lanthanum crown optical glass generally adopts La₂O₃To achieve high refractive index and low dispersion, a large amount of La is introduced to achieve the desired refractive index₂O₃. The inventor researches and discovers that the La is too high₂O₃The problem that the acid resistance and the thermal shock resistance of the glass cannot meet the design requirements due to the deterioration of the acid resistance and the improvement of the thermal expansion coefficient of the glass is caused in Al₂O₃The content is more obvious when the content is more than 10 percent. However, if La is not added₂O₃The refractive index and dispersion of the glass do not meet the design requirements. Therefore, to ensure that the refractive index and Abbe number of the glass of the present invention meet the design expectations, La₂O₃The content of (b) is 15% or more, preferably 18% or more, more preferably 20% or more. If La₂O₃The content of (b) is more than 40%, the acid resistance of the glass is rapidly deteriorated, and the thermal expansion coefficient is rapidly increased, so that the content is 40% or less, preferably 35% or less, and more preferably 30% or less.

In the invention, 45% or less of Y is introduced₂O₃Can reduce La₂O₃In an amount of (B) while using Y³⁺The ion field has the advantage of high intensity, so that the acid resistance of the glass is improved and the thermal expansion coefficient of the glass is reduced while high refractive index and low dispersion are realized; if Y is₂O₃The addition amount of the glass is less than 10 percent, the acid resistance and the thermal shock resistance of the glass can not meet the design requirements, and the hardness of the glass is reduced. Thus, Y in the present invention₂O₃The content of (b) is 10 to 45%, preferably 13 to 40%, more preferably 15 to 35%.

Further, the inventors have found that when La is used₂O₃/Y₂O₃When the value of (d) is greater than 2.1, the acid resistance of the glass is rapidly reduced; when La₂O₃/Y₂O₃When the value of (A) is less than 0.5, the temperature coefficient of refractive index of the glass rapidly rises, and the glass does not meet the design requirement, and simultaneously the stability of the glass rapidly falls. Thus, La₂O₃/Y₂O₃The value of (A) is in the range of 0.5 to 2.1, preferablyThe acid resistance, the temperature coefficient of the refractive index and the glass stability are most balanced when the content is in the range of 0.6 to 1.9, and more preferably in the range of 0.7 to 1.7.

An appropriate amount of Gd₂O₃The addition to the glass can reduce the tendency of the glass to devitrify, especially in the Y₂O₃The effect is more remarkable when the content exceeds 20%, but if the content exceeds 10%, the devitrification resistance of the glass is sharply reduced. Thus, Gd₂O₃The content of (b) is limited to 10% or less, preferably 5% or less. In some embodiments, it is more preferable not to add Gd if the glass has a margin in devitrification resistance₂O₃。

Appropriate amount of TiO₂The thermal expansion coefficient of the glass can be rapidly reduced by adding the glass into the glass, so that the thermal shock resistance is rapidly improved. However, TiO₂The dispersion is large, and if the content exceeds 10%, the dispersion of the glass is higher than the design requirement. More importantly, since the glass of the present invention has less free oxygen, more than 10% TiO₂The addition to the glass causes a sharp decrease in transmittance. Thus, TiO₂The content of (b) is limited to 10% or less, preferably 5% or less. In some embodiments, it is more preferable not to add TiO if the glass has a margin in its thermal shock resistance₂。

Appropriate amount of ZrO₂The glass is added into the glass, so that the thermal expansion coefficient of the glass can be reduced, and the acid resistance of the glass is improved. If ZrO of₂The content exceeds 8%, the glass meltability becomes poor, and the risk of reduction in transmittance and inclusion is brought; if ZrO of₂The content is less than 0.5 percent, and the corrosion of the glass to refractory materials in the melting process is increased rapidly, thereby bringing about the problems of transmittance reduction and smelting furnace service life reduction. Thus, ZrO₂The content of (B) is limited to 0.5 to 8%, preferably 0.5 to 6%, more preferably 0.5 to 4%.

Nb₂O₅The addition of the glass into the glass can improve the refractive index of the glass and the stability of the glass, but the dispersion is large, and if the addition amount exceeds 5%, the dispersion of the glass cannot meet the design requirement, so the content of the glass is limited to be less than 5%. Nb with a margin of glass stability₂O₅The content is preferably 3% or less, and more preferably no Nb is added₂O₅。

The addition of an appropriate amount of ZnO to the glass can lower the thermal expansion coefficient of the glass, raise the refractive index of the glass, and particularly, it is important to raise the acid resistance of the glass, and if the content is more than 10%, the dispersion of the glass is higher than the design requirement, and the hardness of the glass is lower than the design requirement, so that the content of ZnO is limited to 10% or less. In some embodiments, when the content of ZnO is less than 0.5%, the effect of improving acid resistance is not significant, and the content of ZnO is preferably 0.5 to 8%, and more preferably 0.5 to 5%.

MgO, CaO, SrO and BaO belong to alkaline earth metal oxides, and when the MgO, the CaO, the SrO and the BaO are added into glass, the refractive index of the glass can be improved, and the stability of the glass can be improved. The inventors have found through studies that the introduction of alkaline earth metal oxides, particularly BaO and SrO, greatly reduces the acid resistance of the glass, and at the same time, the thermal expansion coefficient of the glass rapidly increases, and the thermal shock resistance of the glass decreases.

The inventor further researches and discovers that the stability of the glass can be improved by introducing proper amount of MgO and CaO, the acid resistance is not reduced basically, and the hardness and the thermal shock resistance of the glass are slightly improved. Therefore, in the present invention, the alkaline earth metal oxide is preferably introduced as MgO and CaO.

The MgO can improve the thermal shock resistance of the glass while adjusting the stability of the glass, but if the content of the MgO exceeds 8 percent, the devitrification resistance of the glass is rapidly reduced, and the glass is cerammed even in smelting; if the content is less than 0.5%, the stability of the glass is lowered and the thermal shock resistance of the glass is lowered. Therefore, the content of MgO is limited to 0.5 to 8%, preferably 0.5 to 6%, and more preferably 0.5 to 4%. The proper amount of CaO added into the glass can obviously improve the hardness of the glass, but if the content of CaO exceeds 8 percent, the acid resistance of the glass is rapidly reduced, and the thermal expansion coefficient of the glass is rapidly increased. Therefore, the content of CaO is limited to 0 to 8%, preferably 0 to 6%, and more preferably 0 to 3%.

In some embodiments of the present invention, the stability, acid resistance and hardness of the glass are most balanced when the CaO/MgO value is between 0 and 1.2, preferably between 0 and 1.0, and more preferably between 0 and 0.8.

In some embodiments, if the glass has a margin in acid and thermal shock resistance, the stability of the glass may be further improved by adding appropriate amounts of BaO and SrO, but the total content of BaO and SrO, BaO + SrO, is not preferably more than 8%. Therefore, the content of BaO + SrO is 0 to 8%, preferably 0 to 4%, and more preferably BaO and SrO are not added.

Li₂O、Na₂O、K₂O belongs to alkali metal oxides, and it is believed that the addition of alkali metal oxides to glass rapidly decreases the acid resistance of the glass, increases the thermal expansion coefficient of the glass, and results in a decrease in the thermal shock resistance. The inventor researches and discovers that the melting temperature of the glass can be reduced and the transmittance of the glass can be improved by adding the proper type and the proper amount of alkali metal oxide into the glass; the glass has low content of alkali earth metal and contains more B₂O₃The addition of a small amount of alkali metal oxide may not reduce or slightly improve the acid resistance and thermal shock resistance, on the contrary. More importantly, the glass has the chemical strengthening capability by adding a proper amount of alkali metal oxide, and the thermal shock resistance of the glass can be greatly improved by the chemical strengthening.

The inventors have further investigated to find that a suitable amount of Li₂O does not damage the acid resistance of the glass, can also reduce the thermal expansion coefficient of the glass, and more importantly, can greatly reduce the melting temperature of the glass; however, Li₂When the O content exceeds 4%, the hardness of the glass is greatly deteriorated. Thus, Li₂The content of O is limited to 4% or less, preferably 3% or less, and Li is more preferable in view of lowering the high-temperature viscosity of the glass₂The content of O is 0.1-2%.

In some embodiments, in the case of glass having a margin in thermal shock resistance and hardness, 4% or less of Na may be added₂O to lower the high temperature viscosity of the glass, preferably Na₂The content of O is 3% or less, and Na is preferably not added₂O。

In some embodiments, the glass has thermal shock resistance and hardnessIf there is a surplus, 4% or less of K may be added₂O to lower the high temperature viscosity of the glass, preferably K₂The content of O is 3% or less, and it is more preferable not to add K₂O。

In some embodiments, when Li is present in the glass₂When it is O, (Na)₂O+K₂O)/Li₂When the value of O is 0 to 1.1, preferably 0 to 1.0, more preferably 0 to 0.8, the glass has an appropriate thermal expansion coefficient and acid resistance and is most excellent in chemical strengthening performance.

In some embodiments of the invention, 0-2% Sb is added₂O₃、SnO₂SnO, NaCl, sulfate and CeO₂As a clarifying agent, preferably Sb is used₂O₃As a fining agent, the fining effect of the glass can be improved. However, the invention has reasonable formula design, good clarification effect and excellent bubble degree, so 0-1% of clarifier is preferably added, 0-0.5% of clarifier is more preferably added, and no clarifier is further preferably introduced.

< 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 "no incorporation", "no inclusion", "no addition" and "0%" described herein mean that the compound, molecule, element or the like 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 >

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.

Refractive index (n) of the optical glass of the present invention_d) 1.65 to 1.79, preferably 1.66 to 1.77; abbe number (v)_d) 48 to 56, preferably 50 to 54.

< stability against acid Effect >

Stability of acid resistance of optical glass (D)_A) (powder method) the test was carried out according to the method prescribed in GB/T17129. Acid resistance stability is sometimes referred to herein simply as acid resistance.

Stability of acid resistance of the optical glass of the present invention (D)_A) Is 3 or more, preferably 2 or more.

< temperature coefficient of refractive index >

Refractive index temperature system of optical glassThe number (dn/dt) was measured according to the method specified in GB/T7962.4-2010, and the temperature coefficient of refractive index (d-line dn/dt relative (10)) was measured in the range of 20-40 deg.C^-6/℃))。

The temperature coefficient of refractive index (dn/dt) of the optical glass of the present invention is 10.0X 10^-6Preferably 9.0X 10 or less/° C^-6Lower than/° C, more preferably 8.5X 10^-6Preferably not more than 8.0X 10/° C^-6Below/° c.

< degree of coloration >

Coloring degree (. lamda.) for short-wave transmission spectral characteristics of the glass of the present invention₈₀) And (4) showing. Lambda [ alpha ]₈₀Refers to the wavelength, lambda, corresponding to a glass having a transmittance of 80%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 colored very little.

Optical glass lambda of the present invention₈₀In the range of less than or equal to 405nm, preferably lambda₈₀In the range of less than or equal to 400nm, more preferably λ₈₀Is less than or equal to 395 nm.

< Knoop hardness >

Knoop hardness (H) of optical glass_K) The test is carried out by using the method specified in GB/T7962.18-2010.

Knoop hardness (H) of the optical glass of the present invention_K) Is 680 x 10⁷Pa or more, preferably 685X 10⁷Pa or more, more preferably 690X 10⁷Pa or above.

< coefficient of thermal expansion >

Optical glass 100 ℃ECoefficient of thermal expansion (α) at 300 DEG C_100/300℃) Testing according to the method specified in GB/T7962.16-2010.

Thermal expansion coefficient (α) of the optical glass of the present invention_100/300℃) Is 75X 10^-7Preferably 73X 10 or less,/K^-7A value of 70X 10 or less, more preferably^-7and/K is less than or equal to.

[ production method ]

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 1300-1350 ℃ 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, vehicle-mounted equipment, camera equipment, display equipment, monitoring equipment and the like.

The optical glass has the properties of excellent chemical stability, lower refractive index temperature coefficient and the like, and is particularly suitable for being applied to the fields of vehicle-mounted monitoring and security protection 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 optical glass 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. Wherein Al is₂O₃/B₂O₃Is denoted by K1; al (Al)₂O₃/SiO₂Is denoted by K2; la₂O₃/Y₂O₃Is denoted by K3; the CaO/MgO value is expressed as K4; (Na)₂O+K₂O)/Li₂The value of O is denoted by 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 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 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 glass, characterized in that itThe components are expressed by weight percentage and comprise: SiO 2₂：10～30％、B₂O₃：5～20％、Al₂O₃：10～35％、La₂O₃：15～40％、Y₂O₃：10～45％、ZrO₂: 0.5-8%, MgO: 0.5 to 8% of Al₂O₃/SiO₂0.4 to 2.0.

2. An optical glass according to claim 1, characterised in that it further comprises, in percentages by weight: p₂O₅：0～5％、Gd₂O₃：0～10％、TiO₂：0～10％、Nb₂O₅：0～5％、ZnO：0～10％、CaO：0～8％、SrO+BaO：0～8％、Li₂O：0～4％、Na₂O：0～4％、K₂O: 0-4% of a clarifying agent: 0 to 2 percent.

3. An optical glass characterized by containing SiO₂、B₂O₃、Al₂O₃、La₂O₃And Y₂O₃The components of which are expressed in weight percentage, wherein Al₂O₃/SiO₂0.4 to 2.0, La₂O₃/Y₂O₃0.5 to 2.1, the refractive index n of the optical glass_dIs 1.65-1.79, and has Abbe number v_dIs 48 to 56.

4. An optical glass according to claim 3, characterised in that its composition, expressed in weight percentage, contains: SiO 2₂：10～30％、B₂O₃：5～20％、Al₂O₃：10～35％、La₂O₃：15～40％、Y₂O₃：10～45％、ZrO₂：0.5～8％、MgO：0.5～8％、P₂O₅：0～5％、Gd₂O₃：0～10％、TiO₂：0～10％、Nb₂O₅：0～5％、ZnO：0～10％、CaO：0～8％、SrO+BaO：0～8％、Li₂O：0～4％、Na₂O：0～4％、K₂O: 0-4% of a clarifying agent: 0 to 2 percent.

5. An optical glass according to any one of claims 1 to 4, characterised in that its composition, expressed in weight percentage, is such that Al is present₂O₃/SiO₂0.5 to 1.8, preferably Al₂O₃/SiO₂0.7 to 1.4.

6. An optical glass according to any one of claims 1 to 4, characterised in that its composition, expressed in weight percentage, is such that Al is present₂O₃/B₂O₃0.5 to 4.0, preferably Al₂O₃/B₂O₃0.7 to 3.5, more preferably Al₂O₃/B₂O₃0.8 to 3.0.

7. An optical glass according to any one of claims 1 to 4, characterised in that its composition is expressed in weight percentage, in which La₂O₃/Y₂O₃0.5 to 2.1, preferably La₂O₃/Y₂O₃0.6 to 1.9, more preferably La₂O₃/Y₂O₃0.7 to 1.7.

8. An optical glass according to any of claims 1 to 4, characterised in that its composition, expressed in weight percentage, is such that CaO/MgO is between 0 and 1.2, preferably CaO/MgO is between 0 and 1.0, more preferably CaO/MgO is between 0 and 0.8.

9. An optical glass according to any of claims 1 to 4, characterised in that its composition is expressed in weight percentage in which (Na)₂O+K₂O)/Li₂O is 0 to 1.1, preferably (Na)₂O+K₂O)/Li₂O is 0 to 1.0, more preferably (Na)₂O+K₂O)/Li₂O is 0 to 0.8.

10. An optical glass according to any one of claims 1 to 4, comprising, in weight percent: SiO 2₂: 12-28%, and/or B₂O₃: 7 to 18%, and/or Al₂O₃: 12-30% and/or La₂O₃: 18 to 35%, and/or Y₂O₃: 13 to 40%, and/or ZrO₂: 0.5-6%, and/or MgO: 0.5 to 6%, and/or P₂O₅: 0 to 3%, and/or Gd₂O₃: 0 to 5%, and/or TiO₂: 0 to 5%, and/or Nb₂O₅: 0-3%, and/or ZnO: 0.5-8%, and/or CaO: 0-6%, and/or SrO + BaO: 0 to 4%, and/or Li₂O: 0 to 3%, and/or Na₂O: 0 to 3%, and/or K₂O: 0-3%, and/or a clarifying agent: 0 to 1 percent.

11. An optical glass according to any one of claims 1 to 4, comprising, in weight percent: SiO 2₂: 14 to 25%, and/or B₂O₃: 9 to 16% and/or Al₂O₃: 14 to 22%, and/or La₂O₃: 20 to 30%, and/or Y₂O₃: 15 to 35%, and/or ZrO₂: 0.5-4%, and/or MgO: 0.5-4%, and/or ZnO: 0.5-5%, and/or CaO: 0 to 3%, and/or Li₂O: 0.1-2%, and/or a clarifying agent: 0 to 0.5 percent.

12. An optical glass according to any of claims 1 to 4, characterised in that it does not contain P in its composition₂O₅And/or does not contain Gd₂O₃And/or does not contain TiO₂And/or no Nb₂O₅And/or does not contain BaO, and/or does not contain SrO, and/or does not contain K₂O, and/or does not contain Na₂O。

13.The optical glass according to any one of claims 1 to 4, wherein the refractive index n of the optical glass is_d1.65 to 1.79, preferably 1.66 to 1.77; abbe number v_d48 to 56, preferably 50 to 54.

14. The optical glass according to any one of claims 1 to 4, wherein the optical glass has an acid-resistance stability D_AIs more than 3 types, and preferably has acid resistance stability D_AIs more than 2 types; and/or a temperature coefficient of refractive index dn/dt of 10.0 x 10^-6A temperature coefficient of refractive index dn/dt of 9.0X 10 is preferably not more than/° C^-6A temperature coefficient of refractive index dn/dt of 8.5X 10 or less^-6A temperature coefficient of refractive index dn/dt of 8.0X 10 or less^-6Below/° c; and/or lambda₈₀Is less than or equal to 405nm, preferably lambda₈₀Is less than or equal to 400nm, more preferably lambda₈₀Is less than or equal to 395 nm; and/or Knoop hardness H_KIs 680 x 10⁷Pa or more, preferably Knoop hardness H_KIs 685 × 10⁷Pa or more, more preferably Knoop hardness H_KIs 690X 10⁷Pa or more, and/or a coefficient of thermal expansion α_100/300℃Is 75X 10^-7below/K, the thermal expansion coefficient is preferably α_100/300℃Is 73X 10^-7A thermal expansion coefficient of α or less is more preferable_100/300℃Is 70X 10^-7and/K is less than or equal to.

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

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

17. An optical device comprising the optical glass according to any one of claims 1 to 14 or the optical element according to claim 16.