CN114772924A

CN114772924A - Optical glass

Info

Publication number: CN114772924A
Application number: CN202210581108.9A
Authority: CN
Inventors: 李丹
Original assignee: CDGM Glass Co Ltd
Current assignee: CDGM Glass Co Ltd
Priority date: 2017-08-21
Filing date: 2017-08-21
Publication date: 2022-07-22
Also published as: CN107399906A

Abstract

The invention provides optical glass which does not contain fluorine, phosphorus and tantalum, and has the advantages of good chemical stability, excellent crystallization performance and good transmittance. The optical glass comprises the following components in percentage by weight: SiO 2₂：13.13‑40％；B₂O₃：5‑17.86％；La₂O₃: greater than 5% but less than or equal to 15%; BaO: 20 to 50 percent. The optical glass lambda has the refractive index of 1.62-1.70 and the Abbe number of 50-60 and simultaneously has reasonable formula design₈₀Less than or equal to 360nm, the upper limit of glass crystallization temperature is less than 940 ℃, and the water-resistant stability D of the glass_WIs more than 1 type, does not contain fluorine, phosphorus and tantalum, and is optical glass with good chemical stability, crystallization performance and transmittance.

Description

Optical glass

The application is a divisional application of an invention patent application with the application number of 201710719334.8 and the application date of 2017, 08 and 21 and named as 'optical glass'.

Technical Field

The invention relates to an optical glass with a refractive index of 1.62-1.70 and an Abbe number of 50-60, and a glass preform and an optical element which are composed of the optical glass.

Background

In recent years, with the development of optoelectronic systems, optical glasses having a refractive index of 1.62 to 1.70 and an abbe number of 50 to 60 have been widely used. Optical glass must have excellent internal qualities such as striae, bubbles, inclusions, and the like, in addition to the optical properties required to be set. In the process of melting, fluorine and phosphorus have certain volatility, so that the optical glass with large fluorine content or large phosphorus content is easy to generate stripes and fluctuation of optical constants. In the production of optical glass, platinum or a platinum alloy is generally used as a melting tool, and when fluorine or phosphorus is contained in the glass composition, the corrosion of platinum is large, thereby producing inclusions in the glass.

CN1303024C discloses an optical glass with a refractive index of 1.60-1.68 and an Abbe number of 40-65, wherein the glass component contains 5-10 mol% of phosphorus and 15-35 mol% of fluorine, and the striae and the inherent quality of the glass are not easy to control. CN101643314A discloses an optical glass with a refractive index of 1.55-1.62 and an Abbe number of 55-62, the glass component contains 35-45 wt% of P₂O₅Glass is highly volatile, striae and of poor intrinsic quality.

In recent years, due to the rapid development of smart phones capable of taking pictures, the market sales of digital cameras are continuously shrinking, and the market competition of optical glass is becoming fierce. Meanwhile, the price of the optical glass raw material is obviously increased, so that the manufacturing cost of the glass is further increased. Only products with low raw material cost and excellent comprehensive performance have stronger competitiveness.

CN1323281A discloses an optical glass with a refractive index of 1.65-1.73 and an Abbe number of 50-60, the glass component contains a certain amount of Ta₂O₅Due to Ta₂O₅The price is high, the production cost of the glass can be greatly improved, and the competitiveness of the glass is reduced.

After polishing the optical element, the optical part needs to be cleaned before coating. At present, ultrasonic cleaning is mainly adopted, and water on the surface of a part is evaporated in a drying dish after the cleaning is finished. In the process, the surface of the part is exposed to water for a certain time. Therefore, if the water resistance of the glass is not good, the polishing layer of the glass is damaged, which brings difficulty to the subsequent coating process. Therefore, the optical glass needs to have better chemical stability so as to improve the yield in the subsequent processing and coating processes.

The optical glass with the refractive index of 1.62-1.70 and the Abbe number of 50-60, and under the condition that phosphorus, fluorine and tantalum are not contained, the glass component contains a certain amount of alkaline earth metal or alkali metal, the chemical stability of the glass is poor, and the subsequent processing is not facilitated.

Disclosure of Invention

The invention aims to provide optical glass which does not contain fluorine, phosphorus and tantalum, and has the advantages of good chemical stability, excellent crystallization performance and good transmittance.

The present invention also provides a glass preform, an optical element and an optical instrument formed of the above optical glass.

The technical scheme adopted by the invention for solving the technical problem is as follows: the optical glass comprises the following components in percentage by weight: SiO 2₂：10-40％；B₂O₃: 5-20% (not including 20%); la₂O₃: greater than 5% but less than or equal to 15%; BaO: 20 to 50 percent.

Further, the method also comprises the following steps: gd (Gd)₂O₃：0-10％；Y₂O₃：0-15％；Yb₂O₃：0-10％；Li₂O：0-10％；Na₂O：0-10％；K₂O：0-10％；MgO：0-10％；CaO：0-15％；SrO：0-10％；ZnO：0-10％；ZrO₂：0-10％；Al₂O₃：0-10％；TiO₂：0-10％；WO₃：0-10％；Nb₂O₅：0-10％；Sb₂O₃: 0 to 1 percent; and/or SnO: 0 to 1 percent; and/or Sn₂O: 0 to 1 percent; and/or CeO₂：0-1％。

The optical glass comprises the following components in percentage by weight: SiO 2₂：10-40％；B₂O₃: 5-20% (not including 20%); la₂O₃: greater than 5% but less than or equal to 15%; BaO: 20 to 50 percent; gd (Gd)₂O₃：0-10％；Y₂O₃：0-15％；Yb₂O₃：0-10％；Li₂O+Na₂O+K₂O：0-10％；MgO：0-10％；CaO：0-15％；SrO：0-10％；ZnO：0-10％；ZrO₂：0-10％；Al₂O₃：0-10％；TiO₂：0-10％；WO₃：0-10％；Nb₂O₅：0-10％；Sb₂O₃: 0 to 1 percent; and/or SnO: 0 to 1 percent; and/or Sn₂O: 0 to 1 percent; and/or CeO₂：0-1％。

Further, the content of each component meets one or more than one of the following 7 conditions:

1)SiO₂+B₂O₃：25-60％；

2)SiO₂/B₂O₃：1-6；

3)(SiO₂+B₂O₃)/La₂O₃：2-7；

4)La₂O₃+Gd₂O₃+Y₂O₃：5-20％；

5)BaO/(SiO₂+B₂O₃)：0.3-1.6；

6)(MgO+CaO+SrO+BaO)/(SiO₂+B₂O₃)：0.3-1.7；

7)Li₂O+Na₂O+K₂O：0-10％。

further, wherein: SiO 2₂: 15 to 35 percent; and/or B₂O₃: 6 to 15 percent; and/or La₂O₃: 7 to 12 percent; and/or BaO: 25 to 45 percent; and/or Gd₂O₃: 0 to 5 percent; and/or Y₂O₃: 0 to 10 percent; and/or Yb₂O₃: 0 to 5 percent; and/or Li₂O: 0 to 5 percent; and/or MgO: 0 to 5 percent; and/or CaO: 0 to 10 percent; and/or SrO: 0 to 5 percent; and/or ZnO: 0.1 to 10 percent; and/or ZrO₂: 0 to 5 percent; and/or Al₂O₃: 0 to 5 percent; and/or TiO₂: 0 to 5 percent; and/or WO₃: 0 to 5 percent; and/or Nb₂O₅: 0 to 5 percent; and/or Sb₂O₃: 0 to 0.5 percent; and/or SnO: 0 to 0.5 percent; and/or Sn₂O: 0 to 0.5 percent; and/or CeO₂：0-0.5％。

Further, wherein: SiO 2₂: 20 to 35 percent; and/or BaO: 30-45%; and/or CaO: 0 to 5 percent; and/or ZnO: 0.1 to 7 percent.

Further, the content of each component satisfies one or more of the following 7 conditions:

1)SiO₂+B₂O₃：35.5-55％；

2)SiO₂/B₂O₃：1.5-5；

3)(SiO₂+B₂O₃)/La₂O₃：3-6；

4)La₂O₃+Gd₂O₃+Y₂O₃：5.5-16％；

5)BaO/(SiO₂+B₂O₃)：0.5-1.2；

6)(MgO+CaO+SrO+BaO)/(SiO₂+B₂O₃)：0.5-1.3；

7)Li₂O+Na₂O+K₂O：0-5％。

further, wherein: SiO 2₂/B₂O₃: 2-4; and/or (SiO)₂+B₂O₃)/La₂O₃: 3.5-5.5; and/or La₂O₃+Gd₂O₃+Y₂O₃: 6.5 to 12 percent; and/or BaO/(SiO)₂+B₂O₃): 0.8-1.1; and/or (MgO + CaO + SrO + BaO)/(SiO)₂+B₂O₃)：0.9-1.1。

Furthermore, the refractive index of the glass is 1.62-1.70, the Abbe number is 50-60, and the corresponding wavelength lambda is when the transmittance of the glass reaches 80 percent₈₀Is 360nm or less.

Furthermore, the upper limit crystallization temperature of the glass is below 940 ℃; stability of the glass to Water action D_WIs more than 1 type.

The glass preform is made of the optical glass.

The optical element is made of the optical glass.

The optical instrument is made of the optical glass.

The beneficial effects of the invention are: the optical glass has the refractive index of 1.62-1.70 and the Abbe number of 50-60 and simultaneously has the lambda number₈₀Less than or equal to 360nm, glass crystallization upper limit temperature below 940 ℃, and water-resistant effect stability D of glass_WIs more than 1 type, does not contain fluorine, phosphorus and tantalum, and has good chemical stability, crystallization performance and transmittance.

Detailed Description

I, optical glass

The composition of the optical glass of the present invention will be described in detail below, and the content and the total content of each glass component are expressed in weight% and the ratio of the content to the total content of the glass component is expressed in weight% unless otherwise specified.

SiO₂Is a glass network generation body, is a framework of optical glass, and has the functions of improving the chemical stability of the glass and maintaining the devitrification resistance of the glass. When SiO₂When the content is less than 10%, the above effects are difficult to achieve; when SiO is present₂Above 40%, the glass becomes very refractory and the desired refractive index of the invention cannot be achieved. Thus, SiO₂The content of (A) is 10 to 40%, preferably in the range of 15 to 35%, more preferably 20 to 35%.

B₂O₃Is a glass network former, in particular in the glass according to the invention, B₂O₃Is an essential component for obtaining stable glass. When B is present₂O₃When the content is less than 5%, the crystallization stability of the glass is not ideal enough; but when B is₂O₃When the content is more than 20%, the chemical stability of the glass is lowered. Thus, B₂O₃The content is limited to 5 to 20% (20% excluded), preferably 6 to 15%.

In the present invention, B₂O₃And SiO₂The network former has the effects of reducing the refractive index and dispersion of glass and improving the crystallization resistance of glass. If B is₂O₃And SiO₂Total amount of (B)₂O₃+SiO₂) Less than 25%, the devitrification resistance stability of the glass does not meet the design requirements(ii) a When B is₂O₃And SiO₂Total amount of (B)₂O₃+SiO₂) When the content is more than 60%, the optical constant of the glass is difficult to satisfy. Thus, the present invention is preferably B₂O₃And SiO₂The total amount of (B) is controlled to 25 to 60%, preferably 35.5 to 55%.

SiO₂And B₂O₃Although it is also a network former of glass, the structure and function formed in glass are not uniform. The proportional relationship of the two network formers is closely related to the internal structure of the glass. That is, in the glass system of the present invention, SiO₂And B₂O₃The proportion relationship of (A) is closely related to the chemical stability and the production performance of the glass. If SiO₂And B₂O₃Ratio of (SiO)₂/B₂O₃Too high, the melting property of the glass may be deteriorated. In addition, too low SiO₂/B₂O₃The chemical stability of the glass can not meet the design requirements. When SiO is present₂/B₂O₃Between 1 and 6, the glass has suitable chemical stability, melting properties and production properties. Thus, the SiO of the invention₂/B₂O₃Is 1 to 6, preferably 1.5 to 5, and more preferably 2 to 4.

La₂O₃Is an essential component for obtaining the glass of the invention, if the content is insufficient, the optical constant is difficult to reach the design requirement; however, when the content is too large, the devitrification resistance of the glass is remarkably deteriorated. Thus, La of the present invention₂O₃Is greater than 5% but less than or equal to 15%, preferably in a content of 7-12%.

The devitrification behavior of the glass has a significant impact on the production of the glass. The glass has high crystallization temperature, so that the viscosity of the glass is too low during glass forming, which is not beneficial to eliminating glass stripes, and the damage to platinum and refractory materials is large, which is not beneficial to reducing the cost, therefore, the reduction of the crystallization temperature of the glass has important significance for improving the glass process performance. The inventors of the present invention found through research that La₂O₃With SiO₂、B₂O₃When a certain proportion exists between the two, the glass with good crystallization performance can be obtained. When (SiO)₂+B₂O₃)/La₂O₃When the refractive index is more than 7, the glass has good crystallization performance, but the refractive index of the glass cannot meet the requirement easily; when (SiO)₂+B₂O₃)/La₂O₃When less than 2, the refractive index of the glass is large, but La is used₂O₃The content of (A) is large, and the devitrification property of the glass is deteriorated. Therefore, the present invention defines (SiO)₂+B₂O₃)/La₂O₃The range is 2 to 7, preferably 3 to 6, and more preferably 3.5 to 5.5.

Gd₂O₃Is helpful for increasing refractive index and reducing dispersion, and partially replaces La₂O₃The devitrification resistance and the chemical stability of the glass can be improved. But the expensive raw material price limits Gd₂O₃Use in glass. Thus, Gd₂O₃The content of (B) is 0 to 10%, preferably 0 to 5%, and more preferably not contained.

Y may also be incorporated into the glass composition of the present invention₂O₃In order to improve the melting property and devitrification resistance of the glass, and to lower the upper limit temperature of devitrification of the glass to improve the chemical stability of the glass, when the content exceeds 15%, the stability and devitrification resistance of the glass are lowered. Thus, Y₂O₃The content is in the range of 0-15%, preferably in the range of 0-10%.

La₂O₃、Gd₂O₃、Y₂O₃All can play a role in improving refractive index and reducing dispersion when La₂O₃、Gd₂O₃And Y₂O₃Total amount of (La)₂O₃+Gd₂O₃+Y₂O₃) When it is too small, it is insufficient to maintain the optical constants of the glass, and when La₂O₃、Gd₂O₃And Y₂O₃Total amount of (La)₂O₃+Gd₂O₃+Y₂O₃) Too large, the devitrification resistance of the glass becomes poor, so that La₂O₃+Gd₂O₃+Y₂O₃The range is defined as 5 to 20%, preferably 5.5 to 16%, and more preferably 6.5 to 12%.

Yb₂O₃Also, when the content of the component which can be added to the glass of the present invention exceeds 10%, the stability and devitrification resistance of the glass are lowered. Thus, Yb₂O₃The content range is defined as 0 to 10%, preferably 0 to 5%, further preferably not incorporated.

As alkali metal oxide Li₂O、Na₂O and K₂O, it is possible to make the glass have a low transition temperature and improve the glass melting effect. But when the total content of the above components (Li)₂O+Na₂O+K₂O) exceeding 10% lowers the chemical stability and weather resistance of the glass, so Li₂O、Na₂O and K₂Total content of O (Li)₂O+Na₂O+K₂O) should be limited to 0-10%, preferably in the range of 0-5%.

In the alkali metal oxide, Li₂O has a great effect on lowering the glass transition temperature, but the raw material cost is relatively high and mass production is not economical, so that the content thereof must be 10% or less, more preferably 5% or less, and still more preferably none.

Na₂O and K₂O is added as necessary to improve the melting property of the glass, but Na is added to maintain the devitrification resistance and chemical stability₂O and K₂The amount of O should be less than 10% each.

BaO is a component for increasing the refractive index of glass and improving the transmittance of glass. When the content is too large, the devitrification resistance and chemical stability of the glass are deteriorated. Therefore, the content is limited to 20 to 50%, preferably 25 to 45%, and more preferably 30 to 45%.

The inventor finds that BaO and SiO are present in the composition₂、B₂O₃When a certain proportional relation exists between the two components, the glass which needs the refractive index and has good transmittance can be obtained. When BaO/(SiO)₂+B₂O₃) When the glass transmittance is less than 0.3, the glass transmittance is high, butThe refractive index of the glass is difficult to meet the requirement; when BaO/(SiO)₂+B₂O₃) If it exceeds 1.6, BaO contained in the glass in a large amount tends to break the intrinsic structure of the glass, resulting in deterioration of transmittance. Therefore, the present invention defines BaO/(SiO)₂+B₂O₃) When the range is 0.3 to 1.6, the range is preferably 0.5 to 1.2, more preferably 0.8 to 1.1.

The addition of SrO to glass makes it possible to adjust the refractive index and Abbe number of the glass, but if the addition amount is too large, the stability of glass and devitrification resistance are deteriorated, and the cost of glass is rapidly increased. Therefore, the SrO content is limited to 0 to 10%, preferably 0 to 5%.

CaO helps to increase the refractive index of the glass, and increases the mechanical strength and hardness of the glass. However, when CaO is added in an excessive amount, the devitrification resistance of the glass is deteriorated. Therefore, the CaO content is limited to 0 to 15%, preferably 0 to 10%, and more preferably 0 to 5%.

If the amount of MgO added is too large, although it is helpful to improve the chemical stability of the glass, the refractive index of the glass does not meet the design requirements, the devitrification resistance of the glass is reduced, and the cost of the glass is rapidly increased. Therefore, the MgO content is limited to 0 to 10%, preferably 0 to 5%, and more preferably not added.

BaO, SrO, CaO and MgO belong to alkaline earth metal oxides and belong to the network outer body in the glass, and the BaO, SrO, CaO and MgO are added into the glass to adjust the refractive index and dispersion of the glass and reduce the high-temperature viscosity of the glass. However, once the loading of the network matrix exceeds the load-bearing capacity of the network structure, the chemical stability and devitrification resistance of the glass is significantly deteriorated. The inventor researches and discovers that when the total content of BaO, SrO, CaO and MgO is equal to that of B₂O₃、SiO₂(BaO + SrO + CaO + MgO)/(B)₂O₃+SiO₂) Between 0.3 and 1.7, the mechanical strength, devitrification resistance and chemical stability of the glass can be brought within the optimum ranges, (BaO + SrO + CaO + MgO)/(B)₂O₃+SiO₂) Preferably 0.5 to 1.3, and more preferably 0.9 to 1.1.

ZnO is an effective component for improving the chemical stability of the glass, and the existence of ZnO can reduce the transition temperature and high-temperature viscosity of the glass, thereby being beneficial to eliminating bubbles in the glass. When the content is small, the above effects cannot be obtained, but when the content is too large, on the one hand, the abbe number of the glass is lowered and the requirement for optical constants cannot be satisfied, and on the other hand, the devitrification resistance and chemical stability of the glass are lowered. Therefore, the content of ZnO is limited to 0 to 10%, preferably 0.1 to 10%, and more preferably 0.1 to 7%.

ZrO₂The glass can improve the thermal stability of the glass and the refractive index of the glass, but when the content of the glass is too high, the glass is difficult to smelt, the manufacturing cost of the glass is increased, and the product competitiveness is reduced. Thus, ZrO of the present invention₂The content of (B) is 0 to 10%, preferably 0 to 5%.

Al₂O₃The chemical stability of the glass can be improved, but when the content exceeds 10%, the dispersion of the glass increases and the meltability deteriorates. Thus, Al of the invention₂O₃The content of (B) is 0 to 10%, preferably 0 to 5%.

TiO₂The glass also has the effect of improving the refractive index of the glass, can participate in the formation of a glass network, can stabilize the glass by being introduced in a proper amount, but the dispersion of the glass is obviously increased after the glass is introduced, and simultaneously, the transmissivity of a short wave part in a visible light area of the glass is reduced, and the tendency of coloring the glass is increased. Thus, the TiO of the present invention₂The content of (B) is 0 to 10%, preferably 0 to 5%, and more preferably not incorporated.

WO₃The effect of increasing the refractive index is exhibited, but when the content exceeds 10%, the dispersion is remarkably increased, and the transmittance on the short wavelength side of the visible light region of the glass is decreased, so that the tendency of coloring is increased. Thus, the present invention WO₃The content of (B) is 0 to 10%, preferably 0 to 5%, and more preferably none.

Nb₂O₅Has the functions of improving the refractive index and dispersion of the glass, and simultaneously has the functions of improving the crystallization resistance and chemical stability of the glass. If the content exceeds 10%, the glass dispersion increases, the optical characteristics of the glass of the present invention cannot be achieved, and the devitrification resistance of the glass deteriorates. Thus, Nb₂O₅The content of (b) is in the range of 0 to 10%, preferably 0 to 5%, further preferably not incorporated.

By adding small amounts of Sb₂O₃The component may improve the refining effect of the glass, but when Sb is used₂O₃When the content exceeds 1%, the glass tends to have a lowered fining property, and the corrosion of platinum or platinum alloy vessels for melting the glass and the deterioration of forming molds are promoted by its strong oxidizing action. Therefore, Sb is preferred in the present invention₂O₃The amount of (B) is 0 to 1%, more preferably 0 to 0.5%.

SnO、SnO₂However, when the content exceeds 1%, the glass is colored, or when the glass is heated, softened, press-molded or the like, Sn becomes a starting point of nucleation and tends to devitrify. Thus the SnO and SnO of the present invention₂The content of (b) is preferably 0 to 1%, more preferably 0 to 0.5%, respectively. CeO (CeO)₂Action and addition amount ratio of (B) and SnO₂In this case, the content is preferably 0 to 1%, more preferably 0 to 0.5%.

[ optical characteristics of optical glass ]

Next, the properties of the optical glass of the present invention will be described.

The optical glass of the present invention has a glass refractive index (n) in view of imparting optical characteristics suitable for the use thereof_d) In the range of 1.62 to 1.70, preferably in the range of 1.64 to 1.68; abbe number (. nu.) of the glass of the invention_d) In the range of 50-60, preferably in the range of 52-58.

[ coloration of optical glass ]

Coloring degree (. lamda.) for short-wave transmittance spectral characteristics of the glass of the present invention₈₀) And (4) showing. Lambda₈₀Refers to the wavelength corresponding to the glass transmittance of 80%, wherein₈₀Was 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_inThrough the glass and out of one planeSurface emission intensity I_outUnder the condition of light of (1) through_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 (b) means that the glass itself is colored very little.

Optical glass lambda of the present invention₈₀Less than or equal to 360nm by making lambda₈₀Less than or equal to 360nm, an optical element constituting an image pickup optical system or a projection optical system excellent in color balance can be provided, and the image pickup optical system and the projection optical system can also be downsized. Accordingly, the optical glass of the present invention is suitable as an optical element material constituting an imaging optical system and a projection optical system.

[ upper limit temperature of devitrification of optical glass ]

Measuring the crystallization performance of the glass by adopting a gradient temperature furnace method, manufacturing the glass into a sample with the size of 180 x 10mm, polishing the side surface, putting the sample into a furnace with a temperature gradient, keeping the temperature for 4 hours, taking out the sample, observing the crystallization condition of the glass under a microscope, and obtaining the highest temperature corresponding to the occurrence of crystals of the glass, namely the crystallization upper limit temperature of the glass. The lower the crystallization upper limit temperature of the glass is, the higher the stability of the glass at high temperature is, and the better the production process performance is.

The upper limit temperature of glass crystallization in the present invention is 940 ℃ or lower, preferably 920 ℃ or lower, and more preferably 900 ℃ or lower.

[ chemical stability of optical glass ]

The ability of the polished surface of an optical glass element to withstand the action of various aggressive media during manufacture and use is referred to as the chemical stability of the optical glass.

Stability to Water action of the glasses according to the invention D_W(powder method) is 1 or more.

Stability to Water action D_W(powder method) according to GB/T17129, calculated according to the following formula:

D_W＝(B-C)/(B-A)*100

in the formula: d_WPercentage of leached glass (%)

B-mass of filter and sample (g)

C-quality (g) of the filter and of the eroded sample

A-Filter Mass (g)

Stabilizing the optical glass against water by the calculated leaching percentage D_WThe classification is 6 in the following table.

Categories	1	2	3	4	5	6
							Percentage leaching (D)_W)	＜0.04	0.04-0.10	0.10-0.25	0.25-0.60	0.60-1.10	＞1.10

II, glass preform and optical element

The present invention also provides an optical glass preform and an optical element, which are formed from the above optical glass according to a method well known to those skilled in the art, and which can be applied to devices such as digital cameras, digital video cameras, camera phones, and the like.

Examples

The present invention is explained by the following examples, but the present invention should not be limited to these examples.

[ optical glass examples ]

First, in order to obtain glass nos. 1 to 30 having compositions shown in tables 1 to 3, carbonates, nitrates, sulfates, hydroxides, oxides, boric acid, etc. were used as raw materials, raw materials corresponding to optical glass components were weighed in proportion, sufficiently mixed to obtain a blended raw material, the blended raw material was put into a platinum crucible, heated to 1250 to 1450 ℃, and clarified and stirred for 3 to 5 hours to obtain a uniform molten glass, and the molten glass was poured into a preheated mold, kept at 600 to 700 ℃ for 2 to 4 hours, and then slowly cooled to obtain each of the optical glasses of glass nos. 1 to 30.

The characteristics of each glass were measured by the following methods, and the measurement results are shown in tables 1 to 3.

(1) Refractive index nd and Abbe number vd

The refractive index and the Abbe number were measured according to the method specified in GB/T7962.11-2010.

(2) Degree of glass coloration (. lamda.)₈₀)

The spectral transmittance was measured using a glass sample having a thickness of 10. + -. 0.1mm with two optically polished planes opposed to each other, and calculated from the result thereof.

(3) Upper limit temperature of glass devitrification

The measurements were carried out as specified above.

(4) Chemical stability D_W

And measuring according to the test method of GB/T17129, and calculating according to a formula.

TABLE 1

TABLE 2

TABLE 3

[ optical preform examples ]

The optical glass obtained in example 1 in table 1 was cut into a predetermined size, and a mold release agent made of boron nitride powder was uniformly applied on the surface, and then heated, softened, and pressure-molded to produce 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 examples ]

The preforms obtained in the above examples of optical preforms were annealed to reduce the deformation inside the glass and to fine-tune the optical properties such as refractive index to the desired values.

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

The optical glass has excellent chemical stability, excellent crystallization performance and good transmittance, the refractive index is 1.62-1.70, the Abbe number is 50-60, and an optical element formed by the glass can meet the requirements of modern novel photoelectric products.

Claims

1. Optical glass, characterized in that its components, expressed in weight percent, contain: SiO 2₂：13.13-40％；B₂O₃：5-17.86％；La₂O₃: greater than 5% but less than or equal to 15%; BaO: 20 to 50 percent.

2. The optical glass of claim 1, further comprising: gd (Gd)₂O₃: 0 to 10 percent; and/or Y₂O₃: 0 to 15 percent; and/or Yb₂O₃: 0 to 10 percent; and/or Li₂O: 0 to 10 percent; and/or Na₂O: 0 to 10 percent; and/or K₂O: 0 to 10 percent; and/or MgO: 0 to 10 percent; and/or CaO: 0 to 15 percent; and/or SrO: 0 to 10 percent; and/or ZnO: 0 to 10 percent; and/or ZrO₂: 0 to 10 percent; and/or Al₂O₃: 0 to 10 percent; and/or TiO₂: 0 to 10 percent; and/or WO₃: 0 to 10 percent; and/or Nb₂O₅: 0 to 10 percent; and/or Sb₂O₃: 0 to 1 percent; and/or SnO: 0 to 1 percent; and/or Sn₂O: 0 to 1 percent; and/or CeO₂：0-1％。

3. The optical glass is characterized by comprising the following components in percentage by weight: SiO 2₂：13.13-40％；B₂O₃：5-17.86％；La₂O₃: greater than 5% but less than or equal to 15%; BaO: 20 to 50 percent; gd (Gd)₂O₃：0-10％；Y₂O₃：0-15％；Yb₂O₃：0-10％；Li₂O+Na₂O+K₂O：0-10％；MgO：0-10％；CaO：0-15％；SrO：0-10％；ZnO：0-10％；ZrO₂：0-10％；Al₂O₃：0-10％；TiO₂：0-10％；WO₃：0-10％；Nb₂O₅：0-10％；Sb₂O₃: 0 to 1 percent; and/or SnO: 0 to 1 percent; and/or Sn₂O: 0 to 1 percent; and/or CeO₂：0-1％。

4. An optical glass according to any of claims 1 to 3, wherein the content of each component satisfies one or more of the following 7 conditions:

1)SiO₂+B₂O₃: 25-55%, preferably SiO₂+B₂O₃：35.5-55％；

2)SiO₂/B₂O₃: 1-6, preferably SiO₂/B₂O₃: 1.5 to 5, more preferably SiO₂/B₂O₃：2-4；

3)(SiO₂+B₂O₃)/La₂O₃: 2-7, preferably (SiO)₂+B₂O₃)/La₂O₃: 3-6, more preferably (SiO)₂+B₂O₃)/La₂O₃：3.5-5.5；

4)La₂O₃+Gd₂O₃+Y₂O₃: 5-20%, preferably La₂O₃+Gd₂O₃+Y₂O₃: 5.5-16%, more preferably La₂O₃+Gd₂O₃+Y₂O₃：6.5-12％；

5)BaO/(SiO₂+B₂O₃): 0.3-1.6, preferably BaO/(SiO)₂+B₂O₃): 0.5 to 1.2, more preferably BaO/(SiO)₂+B₂O₃)：0.8-1.1；

6)(MgO+CaO+SrO+BaO)/(SiO₂+B₂O₃): 0.3 to 1.7, preferably (MgO + CaO + SrO + BaO)/(SiO)₂+B₂O₃): 0.5 to 1.3, more preferably (MgO + CaO + SrO + BaO)/(SiO)₂+B₂O₃)：0.9-1.1；

7)Li₂O+Na₂O+K₂O: 0-10%, preferably Li₂O+Na₂O+K₂O：0-5％。

5. An optical glass as defined in any of claims 1-3, wherein: SiO 2₂: 15-35%, preferably SiO₂: 20 to 35 percent; and/or B₂O₃: 6 to 15 percent; and/or La₂O₃: 7 to 12 percent; and/or BaO: 25-45%, preferably BaO: 30-45%; and/or Gd₂O₃: 0 to 5 percent; and/or Y₂O₃: 0 to 10 percent; and/or Yb₂O₃: 0 to 5 percent; and/or Li₂O：0-5％；And/or MgO: 0 to 5 percent; and/or CaO: 0-10%, preferably CaO: 0 to 5 percent; and/or SrO: 0 to 5 percent; and/or ZnO: 0.1 to 10%, preferably ZnO: 0.1 to 7 percent; and/or ZrO₂: 0 to 5 percent; and/or Al₂O₃: 0 to 5 percent; and/or TiO₂: 0 to 5 percent; and/or WO₃: 0 to 5 percent; and/or Nb₂O₅: 0 to 5 percent; and/or Sb₂O₃: 0 to 0.5 percent; and/or SnO: 0 to 0.5 percent; and/or Sn₂O: 0 to 0.5 percent; and/or CeO₂：0-0.5％。

6. An optical glass according to any of claims 1 to 3, wherein the refractive index of the optical glass is in the range of 1.62 to 1.70, preferably 1.64 to 1.68, more preferably 1.65000 to 1.66421; the Abbe number is 50 to 60, preferably 52 to 58, more preferably 54.76 to 58, and further preferably 55.32 to 57.11.

7. An optical glass as defined in any of claims 1-3, wherein said optical glass has a transmittance up to 80% at the corresponding wavelength λ₈₀360nm or less, preferably 355nm or less; and/or the upper crystallization temperature is 940 ℃ or lower, preferably 920 ℃ or lower, and more preferably 900 ℃ or lower; and/or stability of the glass to water action D_WIs more than 1 type.

8. A glass preform made of the optical glass according to any one of claims 1 to 7.

9. An optical element produced by using the optical glass according to any one of claims 1 to 7.

10. An optical device made of the optical glass according to any one of claims 1 to 7.