CN112028474A

CN112028474A - Optical glass

Info

Publication number: CN112028474A
Application number: CN202010952510.4A
Authority: CN
Inventors: 毛露路; 郝良振; 匡波
Original assignee: CDGM Glass Co Ltd
Current assignee: CDGM Glass Co Ltd
Priority date: 2020-09-11
Filing date: 2020-09-11
Publication date: 2020-12-04
Anticipated expiration: 2040-09-11
Also published as: CN112028474B

Abstract

The invention provides an optical glass with a refractive index of 1.50-1.56, an Abbe number of 57-67 and a bubble degree and a fringe degree meeting the requirements of an imaging grade, which comprises the following components in percentage by weight: SiO 2₂：50～80％；B₂O₃：3～20％；Li₂O+Na₂O+K₂O: 5 to 25% of B, wherein₂O₃/SiO₂Is 0.36 or less, (Li)₂O+Na₂O+K₂O)/B₂O₃0.8 to 3.0. Through reasonable component design, the optical glass obtained by the invention has excellent chemical stability and weather resistance, excellent internal quality and light transmittance and low raw material cost, and can be used in the fields of manufacturing high-precision imaging-grade vehicle-mounted headlamp lenses and the like.

Description

Optical glass

Technical Field

The present invention relates to an optical glass, and more particularly to an optical glass excellent in chemical stability and weather resistance, and a glass preform, an optical element and an optical instrument made therefrom.

Background

In the prior art, the automobile headlamp lens is usually made of pyrex glass, and the pyrex glass has a lower thermal expansion coefficient and higher chemical stability and has greater advantages in manufacturing the automobile lens. With the development of vehicle-mounted headlamp technology towards intellectualization, high power, precise control, laser light source and other directions, the quality of an automobile lens is correspondingly improved towards an imaging level, and even a more precise aspheric lens needs to be manufactured. The high-temperature viscosity of the pyrex glass is very high, and the bubble degree and the streak degree of the glass can not meet the optical grade imaging requirement even at the melting temperature of 1600 ℃. Meanwhile, because of the need of very high melting temperature during production, the corrosion of the glass solution to the refractory material is very serious, so that transition metal ion impurities in the refractory material enter the glass, the light transmittance of the glass cannot meet the requirement of optical-level imaging, and the glass even becomes green in serious cases.

On the other hand, the refractive index of the pyrex glass is 1.47, which is lower than the requirements of the design of the lens of the vehicle lamp in the future. Therefore, based on the fact that the conventional pyrex glass cannot meet the development requirements of the future lamp lens, the lamp lens manufacturers try to use the optical glass with the refractive index of 1.50-1.56 and the Abbe number of 57-67 to manufacture the automobile headlight lens. The optical glass with the refractive index and the Abbe number range belongs to crown optical glass, the optical glass is mainly used for precise optical imaging equipment in the initial development stage, and the requirement of bearing the severe use condition similar to that of an automobile headlamp lens is basically not considered. In addition, the optical glass is applied to an imaging system, extremely high transmittance, striae and bubble degree are required, and the raw material cost and the production cost are several times higher than those of the traditional automobile headlamp lens glass material for illumination. Therefore, such optical glasses are currently difficult to achieve the expectations of manufacturers of automotive headlamp lenses in terms of chemical stability and weatherability, as well as cost control.

Disclosure of Invention

Aiming at the defects of the prior art and the development requirements of the vehicle lamp lens in the future, the invention aims to solve the technical problem of providing the optical glass which has the advantages of 1.50-1.56 of refractive index, 57-67 of Abbe number, excellent chemical stability and weather resistance, high light transmittance and imaging level requirements of bubble degree and stripe degree and can be used for manufacturing the high-precision imaging level vehicle-mounted headlamp lens.

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 2₂：50～80％；B₂O₃：3～20％；Li₂O+Na₂O+K₂O: 5 to 25% of B, wherein₂O₃/SiO₂Is 0.36 or less, (Li)₂O+Na₂O+K₂O)/B₂O₃0.8 to 3.0.

(2) The optical glass according to (1), which comprises the following components in percentage by weight: al (Al)₂O₃+ZrO₂: 0.05-5%; and/or TiO₂: 0 to 4 percent; and/or BaO + CaO: 0 to 5 percent; and/or ZnO: 0 to 5 percent; and/or MgO: 0 to 3 percent; and/or SrO: 0 to 5 percent; and/or La₂O₃: 0 to 5 percent; and/or Gd₂O₃: 0 to 5 percent; and/or Y₂O₃: 0 to 5 percent; and/or Sb₂O₃：0～1％。

(3) Optical glass containing SiO₂、B₂O₃And an alkali metal oxide, the components of which are expressed in weight percent, wherein B₂O₃/SiO₂Is 0.36 or less, (Li)₂O+Na₂O+K₂O)/B₂O₃0.8 to 3.0, the refractive index n of the optical glass_dIs 1.50 to 1.56, and has an Abbe number v_d57 to 67, stability of acid resistance of optical glass D_AIs of class 2 or more, and has a coefficient of thermal expansion of alpha_20/300℃Is 92 x 10^-7and/K is less than or equal to.

(4) The optical glass according to (3), which comprises the following components in percentage by weight: SiO 2₂: 50-80%; and/or B₂O₃: 3-20%; and/or Li₂O+Na₂O+K₂O: 5-25%; and/or Al₂O₃+ZrO₂: 0.05-5%; and/or TiO₂: 0 to 4 percent; and/or BaO + CaO: 0 to 5 percent; and/or ZnO: 0 to 5 percent; and/or MgO: 0 to 3 percent; and/or SrO: 0 to 5 percent; and/or La₂O₃: 0 to 5 percent; and/or Gd₂O₃: 0 to 5 percent; and/or Y₂O₃: 0 to 5 percent; and/or Sb₂O₃：0～1％。

(5) Optical glass, the composition of which is expressed in weight percentage by SiO₂：50～80％；B₂O₃：3～20％；Li₂O+Na₂O+K₂O：5～25％；Al₂O₃+ZrO₂：0.05～5％；TiO₂：0～4％；BaO+CaO：0～5％；ZnO：0～5％；MgO：0～3％；SrO：0～5％；La₂O₃：0～5％；Gd₂O₃：0～5％；Y₂O₃：0～5％；Sb₂O₃: 0 to 1% of a component B₂O₃/SiO₂Is 0.36 or less, (Li)₂O+Na₂O+K₂O)/B₂O₃0.8 to 3.0.

(6) The optical glass according to any one of (1) to (5), which comprises the following components in percentage by weight: SiO 2₂: 55-78%; and/or B₂O₃: 5-18%; and/or Li₂O+Na₂O+K₂O: 7-22%; and/or Al₂O₃+ZrO₂: 0.05-3%; and/or TiO₂: 0-2%; and/or BaO + CaO: 0.1-4%; and/or ZnO: 0 to 3 percent; and/or MgO: 0-2%; and/or SrO: 0 to 3 percent; and/or La₂O₃: 0 to 3 percent; and/or Gd₂O₃: 0 to 3 percent; and/or Y₂O₃: 0 to 3 percent; and/or Sb₂O₃：0～0.8％。

(7) The optical glass according to any one of (1) to (5), which comprises the following components in percentage by weight: SiO 2₂: 60-75%; and/or B₂O₃: 6-17%; and/or Li₂O+Na₂O+K₂O: 9-20%; and/or Al₂O₃+ZrO₂: 0.05-1.5%; and/or BaO + CaO: 0.5-3%; and/or Sb₂O₃：0～0.5％。

(8) The optical glass according to any one of (1) to (5), which comprises the following components in percentage by weight: (Li)₂O+Na₂O+K₂O+B₂O₃)/(SiO₂+Al₂O₃) 0.2 to 0.8, preferably (Li)₂O+Na₂O+K₂O+B₂O₃)/(SiO₂+Al₂O₃) 0.25 to 0.7, more preferably (Li)₂O+Na₂O+K₂O+B₂O₃)/(SiO₂+Al₂O₃) 0.3 to 0.6, and more preferably (Li)₂O+Na₂O+K₂O+B₂O₃)/(SiO₂+Al₂O₃) 0.3 to 0.5.

(9) The optical glass according to any one of (1) to (5), which comprises the following components in percentage by weight: b is₂O₃/SiO₂Is 0.3 or less, preferably B₂O₃/SiO₂Is 0.25 or less, more preferably B₂O₃/SiO₂0.1 to 0.2.

(10) The optical glass according to any one of (1) to (5), which comprises the following components in percentage by weight: (Li)₂O+Na₂O+K₂O)/B₂O₃1.1 to 2.8, preferably (Li)₂O+Na₂O+K₂O)/B₂O₃1.2 to 2.5, more preferably (Li)₂O+Na₂O+K₂O)/B₂O₃Is 1.2 to 2.0.

(11) The optical glass according to any one of (1) to (5), which comprises the following components in percentage by weight: k₂O/Na₂O is 0.15 to 0.9, preferably K₂O/Na₂O is 0.2 to 0.85, and K is more preferably₂O/Na₂O is 0.3 to 0.8, and K is more preferably₂O/Na₂O is 0.5 to 0.75.

(12) The optical glass according to any one of (1) to (5), which comprises the following components in percentage by weight: li₂O: 0 to 5%, preferably Li₂O: 0 to 3 percent; and/or BaO: 0-3%, preferably BaO: 0 to 2%, more preferably BaO: 0.1-2%; and/or CaO: 0-3%, preferably CaO: 0-2%, more preferably CaO: 0.1 to 2 percent.

(13) The optical glass according to any one of (1) to (5), wherein the components do not contain Li₂O; and/or no ZnO; and/or does not contain TiO₂(ii) a And/or does not contain SrO; and/or does not contain MgO; and/or do not contain La₂O₃(ii) a And/or does not contain Y₂O₃(ii) a And/or does not contain Gd₂O₃。

(14) The refractive index n according to any one of (1) to (5)_d1.50 to 1.56, preferably 1.50 to 1.55, more preferably 1.51 to 1.54; and/or Abbe number v_d57 to 67, preferably 60 to 66, and more preferably 62 to 65.

(15) The optical glass according to any one of (1) to (5) having a light transmittance τ_400nm98.0% or more, preferably 99.0% or more, more preferably 99.5% or more, further preferably 99.7% or more, and further preferably 99.8% or more; and/or the optical glass has a weatherability CR of 2 or more, preferably 1; and/or stability of the optical glass against acid action D_AIs 2 or more, preferably 1; and/or the coefficient of thermal expansion alpha of the optical glass_20/300℃Is 92 x 10^-7Preferably 90X 10 or less,/K^-7A value of less than or equal to K, more preferably 88X 10^-7below/K; and/or the viscosity of the optical glass at 1400 ℃ is 200 poise or less, preferably 180 poise or less, more preferably 150 poise or less; and/or the optical glass has a viscosity of 1500 poise or less, preferably 1200 poise or less, more preferably 1000 poise or less at 1200 ℃; and/or the optical glass has a bubble degree of class A or more, preferably class A₀More preferably A or more₀₀A stage; and/or the optical glass has a striae of D class or more, preferably C class or more, and more preferably B class or more.

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

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

(18) An optical device comprising the optical glass according to any one of (1) to (15) and/or the optical element according to (17).

The invention has the beneficial effects that: through reasonable component design, the optical glass obtained by the invention has excellent chemical stability and weather resistance, excellent internal quality and light transmittance and low raw material cost, and can be used in the fields of manufacturing high-precision imaging-grade vehicle-mounted headlamp lenses and the like.

In some embodiments, the optical glass obtained by the invention has low high-temperature viscosity, good process performance, low unit production energy consumption and low nitrogen oxide emission, and can meet the requirements of a one-time dropping forming process. In some embodiments, the optical glass obtained by the invention has a low thermal expansion coefficient, is suitable for drawing a glass bar stock, has small surface shrinkage of the bar stock when the bar stock is drawn, and has high yield and strong thermal shock resistance.

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, the contents and total contents of the respective components are all expressed in terms of weight percent (wt%) relative 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 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 >

SiO₂Is the basic component of the glass formed by the invention and is the main component forming the glass network. If SiO₂The content of (A) exceeds 80%, the glass becomes refractory, the high-temperature viscosity is sharply increased, and inclusions such as bubbles or stones are easily generated in the product, so that the internal quality requirement cannot be met, and the refractive index of the glass cannot meet the design requirement. Thus, SiO₂The content of (b) is limited to 80% or less, preferably 78% or less, and more preferably 75% or less. On the other hand, if SiO₂The content of (A) is less than 50%, and the acid resistance of the glass does not meet the design requirement. Thus, SiO₂The content of (b) is 50% or more, preferably 55% or more, more preferably 60% or more.

B₂O₃In the glasses according to the invention, the refractive index and the dispersion are greatly influenced if B₂O₃Is higher than 20%, B₂O₃The structure of (2) is developed towards loosening, the refractive index is rapidly reduced to be difficult to meet the design requirement, and meanwhile, the acid resistance and the weather resistance of the glass are rapidly reduced. If the content is less than 3%, the dispersion of the glass is higher than the design requirement, the melting temperature and the high-temperature viscosity are increased, the inherent quality of the glass is poor, and the unit energy consumption for producing the glass is increased. Thus, in the present invention B₂O₃The content is 3 to 20%, preferably 5 to 18%, and more preferably 6 to 17%.

In some embodiments, B₂O₃/SiO₂The value of (A) has a great influence on the binding capacity of alkali metal ions, and influences the precipitation of the alkali metal ions, thereby influencing the weather resistance and the acid resistance of the glass. When the glass contains B in a proper amount₂O₃In addition, the alkali metal ion pair SiO can be repaired₂The network is broken, so that the binding capacity of the glass network to alkali metal ions is improved. However, with B₂O₃/SiO₂Gradually increases, especially over 0.36, B₂O₃The network of the glass starts to be destroyed, and the binding capacity to alkali metal ions is rapidly reduced, thereby causing the acid resistance and weather resistance of the glass to be reduced. Therefore, B is preferred₂O₃/SiO₂Has a value of 0.36 or less, more preferably B₂O₃/SiO₂A value of (B) is 0.3 or less, and B is more preferably₂O₃/SiO₂Has a value of 0.25 or moreNext, B is more preferable₂O₃/SiO₂The value of (b) is 0.1 to 0.2.

Li₂O、Na₂O、K₂O belongs to alkali metal oxide, and can improve the glass forming performance of the glass, reduce the melting temperature and high-temperature viscosity of the glass, and can adjust the refractive index and dispersion of the glass by cooperating with other components.

In some embodiments of the present invention, it is desirable to obtain glasses having excellent weatherability and acid resistance, which is primarily to prevent and reduce precipitation of alkali metal ions; on the other hand, the glass is expected to have lower high-temperature viscosity, so that the difficulty and energy consumption of the production process are reduced; on the other hand, the obtained glass is expected to have a lower thermal expansion coefficient, the reduction of the thermal expansion coefficient of the glass can reduce the surface shrinkage of a bar when the bar is drawn, the yield is high, and meanwhile, the thermal shock resistance of the glass is strong.

In the prior art, it has been difficult to obtain the above-mentioned desired weather resistance, acid resistance, high-temperature viscosity and thermal expansion coefficient simultaneously for the present system glass. The inventors found through research that if Li₂O、Na₂O、K₂The total amount of O is less than 5 percent, the high-temperature viscosity of the glass is higher than the design requirement, and the acid resistance and the weather resistance of the glass cannot meet the design requirement easily; if the total content is more than 25%, the thermal expansion coefficient of the glass is higher than the design requirement, and the acid resistance and weather resistance of the glass are difficult to meet the design requirement. Therefore, Li is preferable₂O、Na₂O、K₂Total amount of O Li₂O+Na₂O+K₂O is 5 to 25%, and Li is more preferable₂O+Na₂O+K₂O is 7 to 22%, and Li is more preferable₂O+Na₂O+K₂O is 9-20%.

Of the three alkali metal oxides mentioned above, Li₂O has the strongest ability to lower the high-temperature viscosity while causing the least deterioration of acid resistance and weather resistance, and is preferably contained in view of lowering the high-temperature viscosity and improving the acid resistance and weather resistance, but if the content exceeds 5%, the time taken for the glass to cool from the liquid state to the solid state in the molding process rapidly increasesThis brings fatal influence to the yield of thick specification product and bar stock product. Thus, Li₂The content of O is limited to 5% or less, preferably 3% or less. Further, Li₂O is more preferably Li-free because O is likely to precipitate during the compression molding to contaminate the mold and the raw material cost is high₂O。

In some embodiments of the invention, a suitable amount of alkali metal oxide promotes B in the glass₂O₃The glass is transformed to a compact structure direction, so that the weather resistance of the glass is improved, and the thermal expansion coefficient of the glass is reduced. When (Li)₂O+Na₂O+K₂O)/B₂O₃When the value of (b) is less than 0.8, the above effect is not significant. When (Li)₂O+Na₂O+K₂O)/B₂O₃When the value of (b) is more than 3.0, excess free oxygen in the glass causes destruction of the glass network, thereby lowering the weather resistance of the glass and rapidly increasing the thermal expansion coefficient of the glass. Therefore, (Li) is preferable₂O+Na₂O+K₂O)/B₂O₃The value of (B) is 0.8 to 3.0, more preferably (Li)₂O+Na₂O+K₂O)/B₂O₃The value of (B) is 1.1 to 2.8, and (Li) is more preferable₂O+Na₂O+K₂O)/B₂O₃The value of (B) is 1.2 to 2.5, and (Li) is more preferable₂O+Na₂O+K₂O)/B₂O₃The value of (b) is 1.2 to 2.0.

Na₂O and K₂O is an alkali metal oxide present predominantly in the glasses of the present invention and has been found by study of the inventors that, in some embodiments of the invention, K₂O/Na₂The ratio of O is closely related to the confinement ability of the glass network to alkali metal ions. When K is₂O/Na₂When the value of O is in the range of 0.15 to 0.9, preferably 0.2 to 0.85, more preferably 0.3 to 0.8, the acid resistance and weather resistance of the glass are optimum, and K is more preferably used₂O/Na₂The value of O is 0.5 to 0.75.

In some embodiments of the present invention, (Li) is used from the viewpoint of reducing the melting temperature and high-temperature viscosity of the glass₂O+Na₂O+K₂O+B₂O₃)/(SiO₂+Al₂O₃) If the value of (A) is less than 0.2, the glass is difficult to melt, and the high-temperature viscosity at 1400 ℃ and 1200 ℃ is higher than the design requirement, so that the problems of increased production energy consumption, reduced service life of a furnace body and the like are caused. If (Li)₂O+Na₂O+K₂O+B₂O₃)/(SiO₂+Al₂O₃) The value of (A) is higher than 0.8, the thermal expansion coefficient of the glass is higher than the design requirement, and the drawing of bar stock is not facilitated and the thermal shock resistance is improved. Therefore, (Li) is preferable₂O+Na₂O+K₂O+B₂O₃)/(SiO₂+Al₂O₃) The value of (B) is 0.2 to 0.8, more preferably (Li)₂O+Na₂O+K₂O+B₂O₃)/(SiO₂+Al₂O₃) The value of (B) is 0.25 to 0.7, and (Li) is more preferable₂O+Na₂O+K₂O+B₂O₃)/(SiO₂+Al₂O₃) The value of (B) is 0.3 to 0.6, and (Li) is more preferable₂O+Na₂O+K₂O+B₂O₃)/(SiO₂+Al₂O₃) The value of (b) is 0.3 to 0.5.

In the glass of the present invention, Al is contained in an appropriate amount₂O₃And ZrO₂The corrosion of the glass to the refractory material can be reduced, so that impurities in the refractory material are reduced to enter the glass, the light transmittance of the glass is further improved, and meanwhile, the service life of the furnace body is also greatly prolonged. Al (Al)₂O₃And ZrO₂Total content of Al₂O₃+ZrO₂If the content is less than 0.05%, the effect is not obvious; if Al is present₂O₃+ZrO₂Above 5%, the viscosity of the glass at high temperature, in particular at 1200 ℃, rises rapidly. Thus, Al₂O₃And ZrO₂Total content of Al₂O₃+ZrO₂0.05-5%, preferably 0.05-3%, more preferably 0.05-1.5%.

TiO₂The compactness of the internal network of the glass can be obviously improved in the glass, thereby improving the thermal shock resistance and the heat shock resistance of the glassChemical stability. If TiO₂The content of (A) is higher than 4%, and the dispersion of the glass rapidly rises and cannot meet the design requirement. Thus, TiO₂The content of (b) is 4% or less, preferably 2% or less. Further, a small amount of TiO₂The light transmittance of the glass can be greatly reduced in the reducing atmosphere in the production process, and if a high-transmittance product is to be produced, a stable oxidizing atmosphere needs to be kept, so that the production process difficulty is increased. With a small amount of TiO₂In glass, the light transmittance of glass is greatly attenuated under the irradiation of 400 to 480nm laser, which is a fatal problem for an illumination system using a laser light source. In summary, it is more preferred in some embodiments to exclude TiO₂。

ZnO, BaO, SrO, CaO and MgO belong to divalent metal oxides, and the refractive index of the glass can be improved in the glass, so that the stability of the glass is enhanced.

A small amount of ZnO can improve the weather resistance of the glass, but because the dispersion of ZnO is high, if the content of ZnO exceeds 5 percent, the Abbe number of the glass can not meet the design requirement. In the present invention, by containing 5% or less of ZnO, preferably 3% or less of ZnO, the surface tension of the glass can be reduced and the inherent quality of the glass product can be improved while achieving the above-described effects. In some embodiments, it is more preferred that no ZnO be present if the glass is chemically stable and has a degree of blistering that meets design requirements.

In the present invention, BaO and CaO may be contained in a total amount of not more than 5% to adjust the refractive index and dispersion of the glass, increase the stability of the refractive index and Abbe number of the glass during the production process, and prevent the acid resistance of the glass from being lowered. Therefore, the total content of BaO and CaO, BaO + CaO, is 0 to 5%, preferably 0.1 to 4%, and more preferably 0.5 to 3%. Further, the content of BaO is limited to 0 to 3%, preferably 0 to 2%, more preferably 0.1 to 2%. The content of CaO is limited to 0 to 3%, preferably 0 to 2%, and more preferably 0.1 to 2%.

In the present invention, SrO may be contained in an amount of 5% or less to reduce the high-temperature viscosity and surface tension of the glass and to solve the problems of the refractive index and abbe number stability during mass production, but since the raw material cost of SrO is high, the SrO content is 0 to 5%, preferably 0 to 3%, and more preferably SrO is not contained.

A small amount of MgO in the glass can improve glass dispersion and acid resistance. However, the refractive index of MgO is low, the dispersion is large, particularly, the accurate content of MgO is not easy to be measured because the Mg-containing raw material is easy to absorb moisture, and the stability of the refractive index and Abbe number is easy to be deteriorated when the Mg-containing raw material is added into glass in mass production. Therefore, the content of MgO is limited to 0 to 3%, preferably 0 to 2%, and more preferably no MgO.

La can be incorporated into the glass₂O₃、Y₂O₃、Gd₂O₃And oxides are added to improve the refractive index of the glass and reduce the dispersion of the glass. While La₂O₃、Y₂O₃、Gd₂O₃And the high-temperature viscosity of the glass can be reduced, and the weather resistance of the glass is improved. The three components have higher field intensity in the glass, and if the single content exceeds 5 percent, the devitrification resistance of the glass is deteriorated, particularly under the production condition that long-time heating and molding are needed. Therefore, La in the present invention₂O₃、Y₂O₃、Gd₂O₃The content of La alone is limited to 5% or less, preferably 3% or less, and more preferably not containing La₂O₃(ii) a And/or does not contain Y₂O₃(ii) a And/or does not contain Gd₂O₃。

Sb₂O₃Is a fining agent, and makes bubble elimination in the glass easier. Sb in the invention₂O₃The content is limited to 0 to 1%, preferably 0 to 0.8%, more preferably 0 to 0.5%.

< component which should not be contained >

In the glass of the present invention, even when a small amount of oxides of transition metals such as V, Cr, Mn, Fe, Co, Ni, Cu, Ag, and Mo is contained singly or in combination, the glass is colored and absorbs at a specific wavelength in the visible light region, thereby impairing the property of the present invention to improve the effect of visible light transmittance.

In recent years, oxides of Th, Cd, Tl, Os, Be, and Se tend to Be used as harmful chemical substances in a controlled manner, and measures for protecting the environment are required not only in the glass production process but also in the processing process and disposal after commercialization. Therefore, when importance is attached to the influence on the environment, it is preferable that these components are not substantially contained except for inevitable mixing. Thereby, the optical glass becomes practically free from substances contaminating the environment. Therefore, the optical glass of the present invention can be manufactured, processed, and discarded without taking special measures for environmental countermeasures.

In order to achieve environmental friendliness, the optical glass of the present invention preferably does not contain As₂O₃And PbO. 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.

"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_d) Is 1.50 to 1.56, preferably 1.50 to 1.55, and more preferably 1.51 to 1.54.

In some embodiments, the Abbe number (v) of the optical glass_d) 57 to 67, preferably 60 to 66, and more preferably 62 to 65.

< light transmittance >

Light transmittance (tau) of optical glass_400nm) The test was carried out according to the method specified in GB/T7962.12-2010.

In some embodiments, the optical glass has a light transmittance (τ)_400nm) Is 98.0% or more, preferably 99.0% or more, more preferably 99.5% or more, still more preferably 99.7% or more, and still more preferably 99.8% or more.

< weather resistance >

The weather resistance (CR) of the optical glass was measured in the following manner.

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

TABLE 1 weather resistance Classification

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

< stability against acid Effect >

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

In some embodiments, the stability of the optical glass against acid action (D)_A) Is 2 or more, preferably 1.

< coefficient of thermal expansion >

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

In some embodiments, the optical glass has a coefficient of thermal expansion (α)_20/300℃) Is 92 x 10^-7Preferably 90X 10 or less,/K^-7A value of less than or equal to K, more preferably 88X 10^-7and/K is less than or equal to.

< high temperature viscosity >

The high-temperature viscosity of the optical glass was measured as follows: the high temperature viscosity of the glass was measured using a THETA Rheotronic II high temperature viscometer using a rotational method and the numerical value is dPaS (poise) and the smaller the value, the smaller the viscosity.

In some embodiments, the optical glass has a viscosity of 200 poise or less, preferably 180 poise or less, and more preferably 150 poise or less at 1400 ℃.

In some embodiments, the optical glass has a viscosity of 1500 poise or less, preferably 1200 poise or less, and more preferably 1000 poise or less at 1200 ℃.

< degree of bubbling >

The bubble degree of the optical glass is tested according to the method specified in GB/T7962.8-2010.

In some embodiments, the optical glass has a bubble degree of class a or more, preferably class a₀More preferably A or more₀₀And (4) stages.

< degree of striae >

The degree of striae of the glass of the present invention was measured according to the method specified in MLL-G-174B. The method is that a fringe instrument composed of a point light source and a lens is used for comparing and checking with a standard sample from the direction of most easily seeing the fringes, the 4 grades are respectively A, B, C, D grades, A grade is that under the specified detection condition, A grade is that no visible fringes exist under the specified detection condition, B grade is that under the specified detection condition, fine and scattered fringes exist, C grade is that under the specified detection condition, slight parallel fringes do not exist, and D grade is that under the specified detection condition, coarse fringes exist.

In some embodiments, the optical glass has a striae of D-grade or greater, preferably C-grade or greater, and more preferably B-grade or greater.

[ production method ]

The method for manufacturing the optical glass comprises the following steps: the glass is produced by adopting conventional raw materials and a conventional process, 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 (such as a platinum crucible, a quartz crucible and the like) at 1250-1450 ℃ 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 of the invention can also be used for manufacturing the glass prefabricated member by adopting a one-step dripping forming method. The optical glass is particularly suitable for manufacturing vehicle headlamp lenses.

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 glass or 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. The optical glass or the optical element is particularly suitable for vehicle-mounted lighting/optical equipment and is applied to the fields of vehicle-mounted, monitoring security and the like.

Examples

< example of optical glass >

In order to further clarify the explanation and explanation of the technical solution of the present invention, the following non-limiting examples are provided.

In this example, optical glasses having compositions shown in tables 2 to 3 were obtained by the above-mentioned method for producing optical glasses. The characteristics of each glass were measured by the test method described in the present invention, and the measurement results are shown in tables 2 to 3.

Table 2.

Table 3.

< glass preform example >

Various lenses such as a concave meniscus lens, a convex meniscus lens, a biconvex lens, a biconcave lens, a plano-convex lens and a plano-concave lens, and preforms such as prisms 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 its components, expressed in weight percent, contain: SiO 2₂：50～80％；B₂O₃：3～20％；Li₂O+Na₂O+K₂O: 5 to 25% of B, wherein₂O₃/SiO₂Is 0.36 or less, (Li)₂O+Na₂O+K₂O)/B₂O₃0.8 to 3.0.

2. An optical glass according to claim 1, characterised in that it further comprises, in percentages by weight: al (Al)₂O₃+ZrO₂: 0.05-5%; and/or TiO₂: 0 to 4 percent; and/or BaO + CaO: 0 to 5 percent; and/or ZnO: 0 to 5 percent; and/or MgO: 0 to 3 percent; and/or SrO: 0 to 5 percent; and/or La₂O₃: 0 to 5 percent; and/or Gd₂O₃: 0 to 5 percent; andor Y₂O₃: 0 to 5 percent; and/or Sb₂O₃：0～1％。

3. An optical glass characterized by containing SiO₂、B₂O₃And an alkali metal oxide, the components of which are expressed in weight percent, wherein B₂O₃/SiO₂Is 0.36 or less, (Li)₂O+Na₂O+K₂O)/B₂O₃0.8 to 3.0, the refractive index n of the optical glass_dIs 1.50 to 1.56, and has an Abbe number v_d57 to 67, stability of acid resistance of optical glass D_AIs of class 2 or more, and has a coefficient of thermal expansion of alpha_20/300℃Is 92 x 10^-7and/K is less than or equal to.

4. An optical glass according to claim 3, characterised in that its composition, expressed in weight percentage, contains: SiO 2₂: 50-80%; and/or B₂O₃: 3-20%; and/or Li₂O+Na₂O+K₂O: 5-25%; and/or Al₂O₃+ZrO₂: 0.05-5%; and/or TiO₂: 0 to 4 percent; and/or BaO + CaO: 0 to 5 percent; and/or ZnO: 0 to 5 percent; and/or MgO: 0 to 3 percent; and/or SrO: 0 to 5 percent; and/or La₂O₃: 0 to 5 percent; and/or Gd₂O₃: 0 to 5 percent; and/or Y₂O₃: 0 to 5 percent; and/or Sb₂O₃：0～1％。

5. Optical glass, characterized in that its composition, expressed in weight percentage, is represented by SiO₂：50～80％；B₂O₃：3～20％；Li₂O+Na₂O+K₂O：5～25％；Al₂O₃+ZrO₂：0.05～5％；TiO₂：0～4％；BaO+CaO：0～5％；ZnO：0～5％；MgO：0～3％；SrO：0～5％；La₂O₃：0～5％；Gd₂O₃：0～5％；Y₂O₃：0～5％；Sb₂O₃: 0 to 1% of a component B₂O₃/SiO₂Is 0.36 or less, (Li)₂O+Na₂O+K₂O)/B₂O₃0.8 to 3.0.

6. An optical glass according to any one of claims 1 to 5, characterised in that its components are expressed in weight percentage, in which: SiO 2₂: 55-78%; and/or B₂O₃: 5-18%; and/or Li₂O+Na₂O+K₂O: 7-22%; and/or Al₂O₃+ZrO₂: 0.05-3%; and/or TiO₂: 0-2%; and/or BaO + CaO: 0.1-4%; and/or ZnO: 0 to 3 percent; and/or MgO: 0-2%; and/or SrO: 0 to 3 percent; and/or La₂O₃: 0 to 3 percent; and/or Gd₂O₃: 0 to 3 percent; and/or Y₂O₃: 0 to 3 percent; and/or Sb₂O₃：0～0.8％。

7. An optical glass according to any one of claims 1 to 5, characterised in that its components are expressed in weight percentage, in which: SiO 2₂: 60-75%; and/or B₂O₃: 6-17%; and/or Li₂O+Na₂O+K₂O: 9-20%; and/or Al₂O₃+ZrO₂: 0.05-1.5%; and/or BaO + CaO: 0.5-3%; and/or Sb₂O₃：0～0.5％。

8. An optical glass according to any one of claims 1 to 5, characterised in that its components are expressed in weight percentage, in which: (Li)₂O+Na₂O+K₂O+B₂O₃)/(SiO₂+Al₂O₃) 0.2 to 0.8, preferably (Li)₂O+Na₂O+K₂O+B₂O₃)/(SiO₂+Al₂O₃) 0.25 to 0.7, more preferably (Li)₂O+Na₂O+K₂O+B₂O₃)/(SiO₂+Al₂O₃) 0.3 to 0.6, and more preferably (Li)₂O+Na₂O+K₂O+B₂O₃)/(SiO₂+Al₂O₃) 0.3 to 0.5.

9. An optical glass according to any one of claims 1 to 5, characterised in that its components are expressed in weight percentage, in which: b is₂O₃/SiO₂Is 0.3 or less, preferably B₂O₃/SiO₂Is 0.25 or less, more preferably B₂O₃/SiO₂0.1 to 0.2.

10. An optical glass according to any one of claims 1 to 5, characterised in that its components are expressed in weight percentage, in which: (Li)₂O+Na₂O+K₂O)/B₂O₃1.1 to 2.8, preferably (Li)₂O+Na₂O+K₂O)/B₂O₃1.2 to 2.5, more preferably (Li)₂O+Na₂O+K₂O)/B₂O₃Is 1.2 to 2.0.

11. An optical glass according to any one of claims 1 to 5, characterised in that its components are expressed in weight percentage, in which: k₂O/Na₂O is 0.15 to 0.9, preferably K₂O/Na₂O is 0.2 to 0.85, and K is more preferably₂O/Na₂O is 0.3 to 0.8, and K is more preferably₂O/Na₂O is 0.5 to 0.75.

12. An optical glass according to any one of claims 1 to 5, characterised in that its components are expressed in weight percentage, in which: li₂O: 0 to 5%, preferably Li₂O: 0 to 3 percent; and/or BaO: 0-3%, preferably BaO: 0 to 2%, more preferably BaO: 0.1-2%; and/or CaO: 0-3%, preferably CaO: 0-2%, more preferably CaO: 0.1 to 2 percent.

13. According to claimAn optical glass according to any of claims 1 to 5, wherein the composition does not contain Li₂O; and/or no ZnO; and/or does not contain TiO₂(ii) a And/or does not contain SrO; and/or does not contain MgO; and/or do not contain La₂O₃(ii) a And/or does not contain Y₂O₃(ii) a And/or does not contain Gd₂O₃。

14. The optical glass according to any one of claims 1 to 5, wherein the refractive index n of the optical glass_d1.50 to 1.56, preferably 1.50 to 1.55, more preferably 1.51 to 1.54; and/or Abbe number v_d57 to 67, preferably 60 to 66, and more preferably 62 to 65.

15. The optical glass according to any one of claims 1 to 5, wherein the optical glass has a light transmittance τ_400nm98.0% or more, preferably 99.0% or more, more preferably 99.5% or more, further preferably 99.7% or more, and further preferably 99.8% or more; and/or the optical glass has a weatherability CR of 2 or more, preferably 1; and/or stability of the optical glass against acid action D_AIs 2 or more, preferably 1; and/or the coefficient of thermal expansion alpha of the optical glass_20/300℃Is 92 x 10^-7Preferably 90X 10 or less,/K^-7A value of less than or equal to K, more preferably 88X 10^-7below/K; and/or the viscosity of the optical glass at 1400 ℃ is 200 poise or less, preferably 180 poise or less, more preferably 150 poise or less; and/or the optical glass has a viscosity of 1500 poise or less, preferably 1200 poise or less, more preferably 1000 poise or less at 1200 ℃; and/or the optical glass has a bubble degree of class A or more, preferably class A₀More preferably A or more₀₀A stage; and/or the optical glass has a striae of D class or more, preferably C class or more, and more preferably B class or more.

16. A glass preform characterized by being made of the optical glass according to any one of claims 1 to 15.

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

18. An optical device comprising the optical glass according to any one of claims 1 to 15 and/or comprising the optical element according to claim 17.