CN109775981B

CN109775981B - Optical glass, glass preform, optical element and optical instrument

Info

Publication number: CN109775981B
Application number: CN201910243830.XA
Authority: CN
Inventors: 孙伟
Original assignee: CDGM Glass Co Ltd
Current assignee: CDGM Glass Co Ltd
Priority date: 2019-03-28
Filing date: 2019-03-28
Publication date: 2022-04-15
Anticipated expiration: 2039-03-28
Also published as: CN109775981A

Abstract

The invention provides a high-refractive-index low-dispersion optical glass, which comprises the following components in percentage by weight: b is₂O₃：20～35％、La₂O₃：32～52％、Y₂O₃：6～20％、Gd₂O₃：0～15％、ZrO₂: 1 to 12% of, wherein Y₂O₃/(Y₂O₃+Gd₂O₃) 0.6 to 1.0, and the Young's modulus E of the optical glass is 10000 x 10⁷Pa or above. Through reasonable component design, the optical glass has high refractive index, low dispersion, low production cost, excellent devitrification resistance and high Young modulus.

Description

Optical glass, glass preform, optical element and optical instrument

Technical Field

The invention relates to optical glass, in particular to optical glass with high refractive index and low dispersion.

Background

Today, with the rapid development of technology, devices such as digital cameras, digital video cameras, and mobile phones capable of taking pictures are becoming more and more popular. Taking a traditional single lens reflex as an example, a plurality of spherical lenses are needed in one lens, and a plurality of spherical lenses can be replaced by one lens by the aspheric lens processed by high-refractive-index low-dispersion optical glass, so that the weight of the lens is greatly reduced. The combination of the lens formed by the high-refractive-index low-dispersion optical glass and the lens formed by the high-refractive-index high-dispersion optical glass can correct chromatic aberration, so that an optical system is miniaturized, and particularly, the market demand is increasing for the high-refractive-index low-dispersion environment-friendly optical glass with the refractive index nd of 1.75-1.81 and the Abbe number vd of 45-51.

At present, the high-refractive-index low-dispersion optical glass is widely applied to the fields of vehicle-mounted monitoring, security protection and the like, and the optical glass is required to have higher hardness, Young modulus and other properties. On the other hand, optical glass is required to be not easy to crystallize and excellent in devitrification resistance in the production and manufacturing process. Chinese patent CN102849942A discloses an optical glass with a refractive index of 1.74-1.80 and an Abbe number of 45-55, which contains 16-23% of Gd₂O₃Poor devitrification resistance and large amount of expensive Gd₂O₃The introduction of (2) also increases the production cost of the optical glass.

Disclosure of Invention

The invention aims to provide optical glass which has high refractive index, low dispersion, low production cost, excellent devitrification resistance and high Young modulus.

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

(1) optical glass comprising the components in weight percentThe ratio, expressed, contains: b is₂O₃：20～35％、La₂O₃：32～52％、Y₂O₃：6～20％、Gd₂O₃：0～15％、ZrO₂: 1 to 12% of, wherein Y₂O₃/(Y₂O₃+Gd₂O₃) 0.6 to 1.0, and the Young's modulus E of the optical glass is 10000 x 10⁷Pa or above.

(2) The optical glass according to (1), which further comprises, in terms of weight percent: SiO 2₂：0～10％、Nb₂O₅：0～10％、ZnO：0～9.5％、Yb₂O₃：0～10％、WO₃：0～5％、TiO₂：0～5％、RO：0～10％、Rn₂O：0～10％、Al₂O₃：0～5％、Ta₂O₅：0～5％、P₂O₅：0～5％、Sb₂O₃: 0-2%, RO is one or more of MgO, CaO, SrO and BaO, Rn₂O is Li₂O、Na₂O、K₂One or more of O.

(3) The optical glass comprises the following components in percentage by weight: b is₂O₃：20～35％、La₂O₃：32～52％、Y₂O₃：1～20％、Gd₂O₃：0～15％、ZrO₂：1～12％、SiO₂：0～10％、Nb₂O₅：0～10％、ZnO：0～9.5％、RO：0～10％、Rn₂O: 0-10%, RO is one or more of MgO, CaO, SrO and BaO, and Rn₂O is Li₂O、Na₂O、K₂One or more of O.

(4) The optical glass according to (3), which comprises the following components in percentage by weight: y is₂O₃: 6 to 20% and/or Yb₂O₃: 0 to 10%, and/or WO₃: 0 to 5%, and/or TiO₂: 0 to 5%, and/or Al₂O₃: 0 to 5%, and/or Ta₂O₅: 0 to 5%, and/or P₂O₅：05% and/or Sb₂O₃: 0 to 2%, and/or Y₂O₃/(Y₂O₃+Gd₂O₃) 0.6 to 1.0.

(5) The optical glass according to any one of (1) to (4), which has a composition satisfying, in terms of weight percent, one or more of the following 8 conditions:

1)ZnO/Y₂O₃is 1.0 or less;

2)Y₂O₃/La₂O₃0.15 to 0.60;

3)ZnO/ZrO₂is less than 0.8;

4)Nb₂O₅/(Nb₂O₅+TiO₂) 0.6 to 1.0;

5)Nb₂O₅/ZrO₂0.15 to 1.5;

6)Ta₂O₅/Nb₂O₅is 1.0 or less;

7)(Nb₂O₅+Y₂O₃)/(B₂O₃+SiO₂+La₂O₃) 0.15 to 0.45;

8)Y₂O₃/(Y₂O₃+Gd₂O₃) 0.75 to 1.0.

(6) The optical glass according to any one of (1) to (4), which comprises, in terms of weight percent: b is₂O₃: 23 to 33%, and/or La₂O₃: 38-48%, and/or Y₂O₃: 8 to 18%, and/or Nb₂O₅: 0.5 to 8%, and/or ZrO₂: 2-10%, and/or ZnO: 0 to 6%, and/or SiO₂: 0 to 8%, and/or Gd₂O₃: 0 to 10% and/or Yb₂O₃: 0 to 5%, and/or WO₃: 0 to 3%, and/or TiO₂: 0-3%, and/or RO: 0 to 5%, and/or Rn₂O: 0 to 5%, and/or Al₂O₃: 0 to 3%, and/or Ta₂O₅: 0 to 3%, and/or P₂O₅: 0 to 3%, and/or Sb₂O₃: 0-1%, RO is one or more of MgO, CaO, SrO and BaO, Rn₂O is Li₂O、Na₂O、K₂One or more of O.

(7) The optical glass according to any one of (1) to (4), which has a composition satisfying, in terms of weight percent, one or more of the following 8 conditions:

1)ZnO/Y₂O₃is less than 0.8;

2)Y₂O₃/La₂O₃0.20 to 0.45;

3)ZnO/ZrO₂is less than 0.5;

4)Nb₂O₅/(Nb₂O₅+TiO₂) 0.8 to 1.0;

5)Nb₂O₅/ZrO₂0.2 to 1.0;

6)Ta₂O₅/Nb₂O₅is 0.6 or less;

7)(Nb₂O₅+Y₂O₃)/(B₂O₃+SiO₂+La₂O₃) 0.20 to 0.40;

8)Y₂O₃/(Y₂O₃+Gd₂O₃) 0.8 to 1.0.

(8) The optical glass according to any one of (1) to (4), which comprises, in terms of weight percent: b is₂O₃: 25 to 31%, and/or La₂O₃: 40-45%, and/or Y₂O₃: 10 to 15%, and/or Nb₂O₅: 1 to 6%, and/or ZrO₂: 4-8%, and/or ZnO: 0 to 4%, and/or SiO₂: 0 to 5%, and/or Gd₂O₃: 0 to 5% 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 to 2%, and/or P₂O₅: 0 to 2%, and/or Sb₂O₃: 0-0.5%, RO is one or more of MgO, CaO, SrO and BaO, Rn₂O is Li₂O、Na₂O、K₂One or more of O.

(9) The optical glass according to any one of (1) to (4), which has a composition satisfying, in terms of weight percent, one or more of the following 8 conditions:

1)ZnO/Y₂O₃is less than 0.5;

2)ZnO/ZrO₂0.35 or less;

3)Nb₂O₅/(Nb₂O₅+TiO₂) 0.9 to 1.0;

4)Nb₂O₅/ZrO₂0.3 to 0.8;

5)Ta₂O₅/Nb₂O₅is less than 0.5;

6)(Nb₂O₅+Y₂O₃)/(B₂O₃+SiO₂+La₂O₃) 0.20 to 0.35;

7)Y₂O₃/(Y₂O₃+Gd₂O₃) 0.9 to 1.0;

8)Y₂O₃/La₂O₃0.25 to 0.40.

(10) The optical glass according to any one of (1) to (4), ZnO/Y₂O₃0.3 or less, and/or Ta₂O₅/Nb₂O₅Is 0.2 or less, and/or (Nb)₂O₅+Y₂O₃)/(B₂O₃+SiO₂+La₂O₃) 0.20 to 0.30.

(11) The optical glass according to any one of (1) to (4), wherein WO is not contained in the composition₃And/or TiO-free₂And/or RO-free, and/or Rn-free₂O, and/or does not contain Ta₂O₅And/or does not contain P₂O₅And/or does not contain Gd₂O₃。

(12) The optical glass according to any one of (1) to (4) having a refractive index nd of 1.75 to 1.81, preferably 1.76 to 1.80, more preferably 1.77 to 1.80; the Abbe number vd is 45 to 51, preferably 45 to 50, and more preferably 46 to 49.

(13) The optical glass according to any one of (1) to (4) above, which has a Young's modulus E of 10000X 10⁷Pa or more, preferably 11000X 10⁷Pa or more, more preferably 12000X 10⁷Pa is above; and/or stability against water action D_WIs 2 or more, preferably 1; and/or coefficient of thermal expansion alpha_-30/70℃Is 80X 10^-7Preferably 70X 10 or less,/K^-7A value of 68X 10 or less, more preferably^-7below/K; and/or a density rho of 4.60g/cm³Hereinafter, it is preferably 4.50g/cm³Hereinafter, more preferably 4.40g/cm³The following; and/or Knoop hardness H_KIs 630X 10⁷Pa or more, preferably 640X 10⁷Pa or more, more preferably 645X 10⁷Pa or above.

(14) A glass preform made of the optical glass according to any one of (1) to (13).

(15) An optical element produced from the optical glass according to any one of (1) to (13) or the glass preform according to (14).

(16) An optical device produced using the optical glass of any one of (1) to (13) or the optical element of (15).

The invention has the beneficial effects that: through reasonable component design, the obtained optical glass has high refractive index, low dispersion, low production cost, excellent devitrification resistance and high Young modulus.

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 glass network forming component, has the functions of improving glass meltability and devitrification resistance and reducing glass transition temperature and density, and in order to achieve the above-mentioned effects, the invention introduces more than 20% 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 35%, the glass stability is lowered and the refractive index is lowered, and therefore, B of the present invention₂O₃The upper limit of the content of (B) is 35%, preferably 33%, more preferably 31%.

SiO₂Also a glass former, with B₂O₃The loose chain-like layered networks formed are different, SiO₂The three-dimensional network of silicon-oxygen tetrahedrons is formed in the glass, and is very compact and firm. Such networks are incorporated into glass for loose boroxine [ BO ]₃]The network is reinforced to be compact, so that the high-temperature viscosity of the glass is improved; if SiO₂The content of (b) exceeding 10% increases the glass transition temperature and lowers the glass meltability, and therefore,SiO in the invention₂The content is 0 to 10%, preferably 0 to 8%, more preferably 0 to 5%, and further preferably 0 to 4%.

La₂O₃Is an essential component for obtaining the desired optical properties of the present invention, in the formulation system of the present 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 32%, it is difficult to achieve desired optical characteristics; however, when the content exceeds 52%, devitrification resistance and melting property of the glass are rather deteriorated. Thus, the La of the present invention₂O₃The content of (b) is 32 to 52%, preferably 38 to 48%, more preferably 40 to 45%.

Gd₂O₃Has the effect of increasing the refractive index, but when the content exceeds 15%, the devitrification resistance of the glass decreases and the transition temperature tends to rise, so that Gd in the present invention₂O₃The content of (b) is 15% or less, preferably 0 to 10%, more preferably 0 to 5%, and further preferably 0 to 3%. In some embodiments, it is further preferred not to introduce Gd₂O₃The devitrification resistance of the glass can be improved and the problem of expensive Gd₂O₃Resulting in a problem of increased cost.

The high-refractive low-dispersion component of the invention preferably also incorporates more than 1% of Y₂O₃By the simultaneous introduction of Y₂O₃And La₂O₃In addition, the glass can be improved in melting property and devitrification resistance while maintaining a high refractive index and a low dispersion, and the glass can be reduced in crystallization upper limit temperature and specific gravity, but if the content exceeds 20%, the glass is reduced in stability and devitrification resistance. Thus, Y in the present invention₂O₃The content of (b) is 1 to 20%, preferably 6 to 20%, more preferably 8 to 18%, and further preferably 10 to 15%.

In the present invention by reacting Y₂O₃And La₂O₃Ratio Y of₂O₃/La₂O₃Within the range of 0.15-0.60, can effectively reduceWhile the glass density is low, the hardness of the glass is increased and the thermal expansion coefficient of the glass is reduced, and Y is preferred₂O₃/La₂O₃In the range of 0.20 to 0.45, more preferably Y₂O₃/La₂O₃In the range of 0.25 to 0.40.

By controlling Y₂O₃/(Y₂O₃+Gd₂O₃) A value of (A) is 0.6 or more, the density of the glass can be reduced, and the chemical stability of the glass can be improved, especially Y₂O₃/(Y₂O₃+Gd₂O₃) The value of (A) is 0.75 or more, and the Young's modulus of the glass can be further improved. Thus Y in the invention₂O₃/(Y₂O₃+Gd₂O₃) The value of (b) is 0.6 to 1.0, preferably 0.75 to 1.0, more preferably 0.8 to 1.0, and further preferably 0.9 to 1.0.

Yb₂O₃And is a component imparting high-refractivity, low-dispersion properties, and when the amount incorporated exceeds 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%.

Nb₂O₅The refractive index of the glass can be effectively 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 is increased, the devitrification resistance is reduced, and the short-wave transmittance in a visible light region is reduced, so that the Nb content of less than 10 percent is introduced into the glass₂O₅The amount of incorporation is preferably 0.5 to 8%, more preferably 1 to 6%.

In the present invention, (Nb) is preferably₂O₅+Y₂O₃)/(B₂O₃+SiO₂+La₂O₃) Within the range of 0.15-0.45, the devitrification resistance and the glass forming stability of the glass can be improved, and the Young modulus of the glass can be improved, (Nb)₂O₅+Y₂O₃)/(B₂O₃+SiO₂+La₂O₃) More preferably 0.20 to 0.40, still more preferably 0.20 to 0.35, and still more preferably 0.20 to 0.30.

ZrO₂Can effectively adjust optical constant and improve anti-devitrification capability and chemical stability, so more than 1 percent of ZrO is introduced in the invention₂(ii) a If ZrO of₂When the content exceeds 12%, the melting property of the glass is lowered, the melting temperature is increased, inclusions in the glass are likely to occur, the transmittance of the glass is likely to be lowered, and it is difficult to maintain a low transition temperature. Thus, ZrO₂The content is set to 1-12%, preferably 2-10%, and more preferably 4-8%.

In some embodiments of the invention, the Nb is reduced₂O₅/ZrO₂Between 0.15 and 1.5, the chemical stability and devitrification resistance of the glass can be improved, and Nb is preferred₂O₅/ZrO₂0.20 to 1.0, more preferably Nb₂O₅/ZrO₂0.30 to 0.80.

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 the present invention, when ZnO and Y are present₂O₃Ratio of (ZnO/Y)₂O₃When the ratio exceeds 1.0, the thermal expansion coefficient of the glass increases and the striae of the glass decreases, so that ZnO/Y is preferable in the present invention₂O₃Below 1.0. Further, by making ZnO/Y₂O₃At less than 0.8, the glass can be optimized in chemical stability while desired optical constants can be obtained easily, and therefore ZnO/Y is more preferable₂O₃At most 0.8, ZnO/Y is more preferable₂O₃At most 0.5, ZnO/Y is more preferable₂O₃Below 0.3.

In some embodiments, if ZnO/ZrO₂When the amount exceeds 0.8, the degree of striae of the glass is deteriorated and the water resistance is lowered, so that ZnO/ZrO in the present invention₂The control is below 0.8. Further, tongOver-rendering ZnO/ZrO₂When the content is 0.5 or less, the hardness of the glass can be increased, so that ZnO/ZrO is preferable in the present invention₂Is 0.5 or less, and ZnO/ZrO is more preferable₂Below 0.35.

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 5% or less, preferably 3% 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 glass when added into the glass, and is added with TiO in proper amount₂In the glass of the present invention, the glass stability can be increased. But if too much TiO₂When added to glass, the objective of low dispersion development is difficult to achieve, and the glass has a significantly reduced transmittance and deteriorated stability. Thus TiO₂The content of (b) is 5% or less, preferably 3% or less, more preferably 2% or less, and further preferably not incorporated.

In the present invention, by using Nb₂O₅/(Nb₂O₅+TiO₂) Above 0.6, the devitrification resistance of the glass can be improved, the coloring degree of the glass is optimized, and the temperature coefficient of the refractive index of the glass is reduced, so that the Nb in the invention₂O₅/(Nb₂O₅+TiO₂) 0.6 to 1.0, preferably Nb₂O₅/(Nb₂O₅+TiO₂) 0.8 to 1.0, more preferably Nb₂O₅/(Nb₂O₅+TiO₂) 0.9 to 1.0.

RO (RO is one or more of BaO, SrO, CaO, or MgO) improves the meltability of the glass and lowers the glass transition temperature, but when the content thereof exceeds 10%, the devitrification resistance of the glass is lowered and the chemical stability 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.

Rn₂O(Rn₂O is Li₂O、Na₂O or K₂One or more of O) improves the meltability of the glass, lowers the glass transition temperature, and when the content thereof exceeds 10%, the glass stability becomes poor, 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.

Al₂O₃The chemical stability of the formed glass can be improved, but when the content exceeds 5%, the dispersion of the glass increases and the meltability deteriorates. Thus, Al of the invention₂O₃The content of (b) is 0 to 5%, preferably 0 to 3%, more preferably 0 to 2%, and further preferably no incorporation.

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, Ta of the present invention₂O₅The content is limited to 0 to 5%, preferably 0 to 3%, more preferably 0 to 2%, and further preferably not incorporated.

In some embodiments of the invention, the composition is prepared by reacting Ta₂O₅And Nb₂O₅Ratio of (Ta)₂O₅/Nb₂O₅Less than 1.0, the glass can obtain excellent chemical stability and optimize the thermal stability of the glass, and Ta is preferred₂O₅/Nb₂O₅Is 0.6 or less, and Ta is more preferable₂O₅/Nb₂O₅Is 0.5 or less, and Ta is more preferable₂O₅/Nb₂O₅Is 0.2 or less.

P₂O₅Is an optional component which may improve the devitrification resistance of the glass, particularly by reacting P₂O₅The content of (A) is 5% or less, and the reduction of the chemical durability, particularly the water resistance, of the glass can be suppressed. Therefore, the content is limited to 5% or less, preferably 3% or less, more preferably 2% or less, and further preferably not incorporated.

By adding small amounts of Sb₂O₃As a fining agent, the fining effect of the glass can be improved, but when Sb is used₂O₃At 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%.

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 5% or less, preferably 3% or less, more preferably 1% or less, and further preferably not incorporated.

In order to better achieve the object of the invention, the glass preferably comprises the components in percent by weight, preferably SiO₂、B₂O₃、La₂O₃、Y₂O₃、Nb₂O₅、ZrO₂ZnO and Sb₂O₃The total content of (A) is 95% or more; more preferably SiO₂、B₂O₃、La₂O₃、Y₂O₃、Nb₂O₅、ZrO₂ZnO and Sb₂O₃The total content of (A) is 97% or more; further preferred is SiO₂、B₂O₃、La₂O₃、Y₂O₃、Nb₂O₅、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 "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 >

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 1.75-1.81, preferably 1.76-1.80, and more preferably 1.77-1.80; the Abbe number (vd) is 45 to 51, preferably 45 to 50, and more preferably 46 to 49.

< 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 4.40g/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 630X 10⁷Pa or more, preferably 640X 10⁷Pa or more, more preferably 645X 10⁷Pa or above.

< Young's modulus >

The Young's modulus (E) of the glass is obtained by measuring the longitudinal wave velocity and the transverse wave velocity of the glass by ultrasonic waves and calculating according to the following formula.

Wherein G ═ V_S ²ρ

In the formula:

e is Young's modulus, Pa;

g is shear modulus, Pa;

V_Tis the transverse wave velocity, m/s;

V_Sis the longitudinal wave velocity, m/s;

rho is the density of the glass, g/cm³；

The Young's modulus (E) of the optical glass of the present invention is 10000X 10⁷Pa or more, preferably 11000X 10⁷Pa or more, more preferably 12000X 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 68X 10 or less, more preferably^-7and/K is less than or equal to.

< transition temperature >

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

Transition temperature (T) of the optical glass of the present invention_g) Is 700 ℃ or lower, preferably 690 ℃ or lower, and more preferably 685 ℃ or lower.

[ 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 1150-1300 ℃ 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, camera 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 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.

TABLE 1

TABLE 2

< 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 is₂O₃：20～35％、La₂O₃：32～52％、Y₂O₃：6～20％、Gd₂O₃：0～15％、ZrO₂: 1 to 12% of, wherein Y₂O₃/(Y₂O₃+Gd₂O₃) 0.6 to 1.0, and the Young's modulus E of the optical glass is 10000 x 10⁷Pa or more, Nb₂O₅/ZrO₂0.365 to 1.5, ZnO/ZrO₂Is 0.376 or less.

2. The optical glass according to claim 1, wherein the composition, expressed in weight percent, further comprises: SiO 2₂：0～10％、Nb₂O₅：0～10％、ZnO：0～9.5％、Yb₂O₃：0～10％、WO₃：0～5％、TiO₂：0～5％、RO：0～10％、Rn₂O：0～10％、Al₂O₃：0～5％、Ta₂O₅：0～5％、P₂O₅：0～5％、Sb₂O₃: 0-2%, RO is one or more of MgO, CaO, SrO and BaO, Rn₂O is Li₂O、Na₂O、K₂One or more of O.

3. Optical glass, characterized in that its components, expressed in weight percent, contain: b is₂O₃：20～35％、La₂O₃：32～52％、Y₂O₃：1～20％、Gd₂O₃：0～15％、ZrO₂：1～12％、SiO₂：0～10％、Nb₂O₅：0～10％、ZnO：0～9.5％、RO：0～10％、Rn₂O: 0 to 10 percent ofRO is one or more of MgO, CaO, SrO and BaO, Rn₂O is Li₂O、Na₂O、K₂One or more of O, Nb₂O₅/ZrO₂0.365 to 1.5, ZnO/ZrO₂Is 0.376 or less.

4. An optical glass according to claim 3, characterised in that its composition, expressed in weight percent, comprises: y is₂O₃: 6 to 20% and/or Yb₂O₃: 0 to 10%, and/or WO₃: 0 to 5%, and/or TiO₂: 0 to 5%, and/or Al₂O₃: 0 to 5%, and/or Ta₂O₅: 0 to 5%, and/or P₂O₅: 0 to 5%, and/or Sb₂O₃: 0 to 2%, and/or Y₂O₃/(Y₂O₃+Gd₂O₃) 0.6 to 1.0.

5. An optical glass according to any one of claims 1 to 4, wherein the composition, expressed in weight percent, satisfies one or more of the following 6 conditions:

1)ZnO/Y₂O₃is 1.0 or less;

2)Y₂O₃/La₂O₃0.15 to 0.60;

3)Nb₂O₅/(Nb₂O₅+TiO₂) 0.6 to 1.0;

4)Ta₂O₅/Nb₂O₅is 1.0 or less;

5)(Nb₂O₅+Y₂O₃)/(B₂O₃+SiO₂+La₂O₃) 0.15 to 0.45;

6)Y₂O₃/(Y₂O₃+Gd₂O₃) 0.75 to 1.0.

6. An optical glass according to any one of claims 1 to 4, characterised in that it consists ofThe weight percentage shows that the composition comprises: b is₂O₃: 23 to 33%, and/or La₂O₃: 38-48%, and/or Y₂O₃: 8 to 18%, and/or Nb₂O₅: 0.5 to 8%, and/or ZrO₂: 2-10%, and/or ZnO: 0 to 6%, and/or SiO₂: 0 to 8%, and/or Gd₂O₃: 0 to 10% and/or Yb₂O₃: 0 to 5%, and/or WO₃: 0 to 3%, and/or TiO₂: 0-3%, and/or RO: 0 to 5%, and/or Rn₂O: 0 to 5%, and/or Al₂O₃: 0 to 3%, and/or Ta₂O₅: 0 to 3%, and/or P₂O₅: 0 to 3%, and/or Sb₂O₃: 0-1%, RO is one or more of MgO, CaO, SrO and BaO, Rn₂O is Li₂O、Na₂O、K₂One or more of O.

7. An optical glass according to any one of claims 1 to 4, wherein the composition, expressed in weight percent, satisfies one or more of the following 7 conditions:

1)ZnO/Y₂O₃is less than 0.8;

2)Y₂O₃/La₂O₃0.20 to 0.45;

3)Nb₂O₅/(Nb₂O₅+TiO₂) 0.8 to 1.0;

4)Nb₂O₅/ZrO₂0.365 to 1.0;

5)Ta₂O₅/Nb₂O₅is 0.6 or less;

6)(Nb₂O₅+Y₂O₃)/(B₂O₃+SiO₂+La₂O₃) 0.20 to 0.40;

7)Y₂O₃/(Y₂O₃+Gd₂O₃) 0.8 to 1.0.

8.An optical glass according to any one of claims 1 to 4, comprising, in weight percent: b is₂O₃: 25 to 31%, and/or La₂O₃: 40-45%, and/or Y₂O₃: 10 to 15%, and/or Nb₂O₅: 1 to 6%, and/or ZrO₂: 4-8%, and/or ZnO: 0 to 4%, and/or SiO₂: 0 to 5%, and/or Gd₂O₃: 0 to 5% 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 to 2%, and/or P₂O₅: 0 to 2%, and/or Sb₂O₃: 0-0.5%, RO is one or more of MgO, CaO, SrO and BaO, Rn₂O is Li₂O、Na₂O、K₂One or more of O.

9. An optical glass according to any one of claims 1 to 4, wherein the composition, expressed in weight percent, satisfies one or more of the following 8 conditions:

1)ZnO/Y₂O₃is less than 0.5;

2)ZnO/ZrO₂0.35 or less;

3)Nb₂O₅/(Nb₂O₅+TiO₂) 0.9 to 1.0;

4)Nb₂O₅/ZrO₂0.365 to 0.8;

5)Ta₂O₅/Nb₂O₅is less than 0.5;

6)(Nb₂O₅+Y₂O₃)/(B₂O₃+SiO₂+La₂O₃) 0.20 to 0.35;

7)Y₂O₃/(Y₂O₃+Gd₂O₃) 0.9 to 1.0;

8)Y₂O₃/La₂O₃0.25 to 0.40.

10. The optical glass according to any of claims 1 to 4, wherein ZnO/Y is₂O₃0.3 or less, and/or Ta₂O₅/Nb₂O₅Is 0.2 or less, and/or (Nb)₂O₅+Y₂O₃)/(B₂O₃+SiO₂+La₂O₃) 0.20 to 0.30.

11. An optical glass according to any of claims 1 to 4, characterised in that its composition does not contain WO₃And/or TiO-free₂And/or RO-free, and/or Rn-free₂O, and/or does not contain Ta₂O₅And/or does not contain P₂O₅And/or does not contain Gd₂O₃。

12. An optical glass according to any one of claims 1 to 4, wherein the optical glass has a refractive index nd of 1.75 to 1.81; the Abbe number vd is 45-51.

13. An optical glass according to any one of claims 1 to 4, wherein the optical glass has a refractive index nd of 1.76 to 1.80; the Abbe number vd is 45-50.

14. An optical glass according to any one of claims 1 to 4, wherein the optical glass has a refractive index nd of 1.77 to 1.80; the Abbe number vd is 46 to 49.

15. An optical glass according to any one of claims 1 to 4, wherein the Young's modulus E of the optical glass is 10000X 10⁷Pa is above; and/or stability against water action D_WIs more than 2 types; and/or coefficient of thermal expansion alpha_-30/70℃Is 80X 10^-7below/K; and/or a density rho of 4.60g/cm³The following; and/or Knoop hardness H_KIs 630X 10⁷Pa or above.

16. An optical glass according to any one of claims 1 to 4, wherein the Young's modulus E of the optical glass is 11000 x 10⁷Pa is above; and/or stability against water action D_WIs of type 1; and/or coefficient of thermal expansion alpha_-30/70℃Is 70X 10^-7below/K; and/or a density rho of 4.50g/cm³The following; and/or Knoop hardness H_KIs 640 multiplied by 10⁷Pa or above.

17. An optical glass according to any one of claims 1 to 4, wherein the Young's modulus E of the optical glass is 12000X 10⁷Pa is above; and/or coefficient of thermal expansion alpha_-30/70℃Is 68 x 10^-7below/K; and/or a density rho of 4.40g/cm³The following; and/or Knoop hardness H_KIs 645X 10⁷Pa or above.

18. A glass preform made of the optical glass according to any one of claims 1 to 17.

19. An optical element produced from the optical glass according to any one of claims 1 to 17 or the glass preform according to claim 18.

20. An optical device comprising the optical glass according to any one of claims 1 to 17 or the optical element according to claim 19.