阅读说明：本技术 具有光吸收层的光学玻璃及其制备方法 (Optical glass with light absorption layer and preparation method thereof ) 是由 那天一 贾金升 郑京明 吕学良 李开宇 李自金 石钰 洪升 李惠全 孙勇 曹振博 于 2020-05-18 设计创作，主要内容包括：本发明是关于一种具有光吸收层的光学玻璃及其制备方法,该制备方法包括：在还原气氛下,对待处理的光学玻璃进行第一处理,所述第一处理的压力为0.5MPa～100MPa；在还原气体和氮气的混合气氛下,对所述第一处理后的光学玻璃进行第二处理,所述第二处理的温度T满足：Tg<T<Tf；对所述第二处理后的光学玻璃进行后处理,得到具有光吸收层的光学玻璃。该光学玻璃包括学玻璃基体和光吸收层,所述光吸收层与所述光学玻璃基体之间的界面反射率小于1％；其中,所述光吸收层为自基底光吸收层,所述光吸收层的光吸收率大于99％。该制备方法解决了难以在结构致密的光学玻璃中制备光吸收层的问题,且不存在受热或者收外界作用力后发生脱落的问题。(The invention relates to an optical glass with a light absorption layer and a preparation method thereof, wherein the preparation method comprises the following steps: carrying out first treatment on optical glass to be treated in a reducing atmosphere, wherein the pressure of the first treatment is 0.5-100 MPa; and carrying out second treatment on the optical glass after the first treatment under a mixed atmosphere of reducing gas and nitrogen, wherein the temperature T of the second treatment satisfies the following conditions: tg < T < Tf; and carrying out post-treatment on the optical glass after the second treatment to obtain the optical glass with the light absorption layer. The optical glass comprises an optical glass substrate and a light absorption layer, wherein the interface reflectivity between the light absorption layer and the optical glass substrate is less than 1%; the light absorption layer is a self-substrate light absorption layer, and the light absorption rate of the light absorption layer is more than 99%. The preparation method solves the problem that the light absorption layer is difficult to prepare in the optical glass with a compact structure, and has no problem of falling off after being heated or receiving external acting force.)

1. A method for producing an optical glass having a light absorbing layer, comprising:

carrying out first treatment on optical glass to be treated in a reducing atmosphere, wherein the pressure of the first treatment is 0.5-100 MPa;

and carrying out second treatment on the optical glass after the first treatment under a mixed atmosphere of reducing gas and nitrogen, wherein the temperature T of the second treatment satisfies the following conditions: tg < T < Tf;

and carrying out post-treatment on the optical glass after the second treatment to obtain the optical glass with the light absorption layer.

2. The method for producing optical glass having a light-absorbing layer according to claim 1, wherein the reducing atmosphere comprises H₂CO and CH₄At least one of (1).

3. The method for producing optical glass having a light-absorbing layer according to claim 1, wherein the time of the first treatment is 1 to 2 hours.

4. The method for producing optical glass having a light-absorbing layer according to claim 1, wherein the temperature of the first treatment is 20 to 30 ℃.

5. The method for producing optical glass having a light-absorbing layer according to claim 1, wherein the volume ratio of the reducing gas to the nitrogen gas in the mixed atmosphere of the reducing gas and the nitrogen gas is 1 to 3: 1, the reducing gas comprises H₂CO and CH₄At least one of (1).

6. The method for producing optical glass having a light-absorbing layer according to claim 1, wherein the pressure of the second treatment is 0.1 to 1 MPa.

7. The method for producing optical glass having a light-absorbing layer according to claim 1, wherein the second treatment time is 1 to 2 hours.

8. The method for producing optical glass having a light-absorbing layer according to claim 1, wherein the post-treatment comprises:

cooling the optical glass after the second treatment to room temperature in a nitrogen atmosphere;

the processed optical glass is cut, ground and polished as necessary to obtain an optical glass having a light absorbing layer.

9. An optical glass having a light absorbing layer, comprising: the optical glass comprises an optical glass substrate and a light absorption layer, wherein the light absorption layer is positioned at the peripheral part of the optical glass substrate, and the interface reflectivity between the light absorption layer and the optical glass substrate is less than 1%; the light absorption layer is a self-substrate light absorption layer, and the light absorption rate of the light absorption layer is more than 99%.

10. The optical glass having a light-absorbing layer according to claim 9, wherein the light-absorbing layer has a thickness of 0.2 to 0.7 mm.

Technical Field

The invention relates to the technical field of optical glass processing, in particular to optical glass with a light absorption layer and a preparation method thereof.

Background

The component made of optical glass is a key element in an optical instrument and can be used for receiving a target optical signal. However, the optical glass itself inevitably generates a certain amount of interfering stray light due to the boundary reflection of the glass material, and the presence of the interfering stray light will undoubtedly affect the imaging accuracy of the optical instrument, and it is necessary to avoid the influence of the light interference as much as possible for the high-accuracy optical instrument. Therefore, some necessary measures are required to reduce or eliminate the adverse effect of the optical interference, thereby improving the accuracy of the optical instrument.

In the field of optical instrument production, the current method for improving stray light eliminating technology is a light absorption layer coating method, namely, a light absorption layer is coated on the edge of an optical lens to absorb stray light scattered to the edge of a device. The technology is simple and easy to implement, has proper cost, and is the method which is most applied at present. However, this method has some disadvantages while having the above advantages, such as: an interface inevitably exists between a coating layer of the optical glass device and the device, and the interface necessarily generates corresponding interface reflection, and the imaging definition of an optical instrument system is also influenced, so that certain influence is exerted on the observation precision; secondly, the difference between the expansion coefficients of the coating layer and the optical lens coated with the coating layer is large, when the lens continuously works in a certain high-low temperature environment or bears high-magnitude mechanical vibration, the coating layer may fall off from the edge of the lens with high probability, so that the normal work of an optical system is influenced, and even the system is scrapped if the coating layer is serious. Based on the above problems, research for exploring a novel stray light eliminating technology with simple process and high stability has received wide attention from researchers at home and abroad.

In order to solve the problem of stray light removal, in recent years, a process for performing high-temperature reduction treatment on an optical lens is also proposed, so that the problem of optical crosstalk of a part of optical glass is solved, but most of the optical glass has a compact structure, and reducing gas is difficult to diffuse into the glass even if the reduction treatment is performed under a high-temperature condition; even if a small portion of the stray light enters, it is difficult to form an absorption layer having a certain thickness, and thus the effect of absorbing a sufficient amount of stray light cannot be achieved.

Disclosure of Invention

The invention mainly aims to provide a preparation method of optical glass with a light absorption layer and a preparation method thereof, and aims to solve the technical problem that the existing high-temperature reduction process cannot meet the requirement of preparing the light absorption layer in the optical glass with a compact structure.

The purpose of the invention and the technical problem to be solved are realized by adopting the following technical scheme. The invention provides a preparation method of optical glass with a light absorption layer, which comprises the following steps:

carrying out first treatment on optical glass to be treated in a reducing atmosphere, wherein the pressure of the first treatment is 0.5-100 MPa;

and carrying out second treatment on the optical glass after the first treatment under a mixed atmosphere of reducing gas and nitrogen, wherein the temperature T of the second treatment satisfies the following conditions: tg < T < Tf;

and carrying out post-treatment on the optical glass after the second treatment to obtain the optical glass with the light absorption layer.

The object of the present invention and the technical problems solved thereby can be further achieved by the following technical measures.

Preferably, in the method for manufacturing optical glass having a light absorbing layer, the reducing atmosphere includes H₂CO and CH₄At least one of (1).

Preferably, in the method for manufacturing the optical glass with the light absorption layer, the time of the first treatment is 1 to 2 hours.

Preferably, in the method for manufacturing an optical glass having a light absorbing layer, the temperature of the first treatment is 20 to 30 ℃.

Preferably, in the method for manufacturing optical glass having a light absorbing layer, the volume ratio of the reducing gas to the nitrogen gas in the mixed atmosphere of the reducing gas and the nitrogen gas is 1:1, and the reducing gas includes H₂CO and CH₄At least one of (1).

Preferably, in the method for producing an optical glass having a light absorbing layer, the pressure of the second treatment is 0.1 to 1 MPa.

Preferably, in the method for manufacturing the optical glass with the light absorption layer, the time of the second treatment is 1 to 2 hours.

Preferably, the method for producing an optical glass having a light absorbing layer described above, wherein the post-treatment comprises:

cooling the optical glass after the second treatment to room temperature in a nitrogen atmosphere;

the processed optical glass is cut, ground and polished as necessary to obtain an optical glass having a light absorbing layer.

The object of the present invention and the technical problem to be solved are also achieved by the following technical means. According to the present invention, there is provided an optical glass having a light absorbing layer, comprising: the optical glass comprises an optical glass substrate and a light absorption layer, wherein the light absorption layer is positioned at the peripheral part of the optical glass substrate, and the interface reflectivity between the light absorption layer and the optical glass substrate is less than 1%; the light absorption layer is a self-substrate light absorption layer, and the light absorption rate of the light absorption layer is more than 99%.

The object of the present invention and the technical problems solved thereby can be further achieved by the following technical measures.

Preferably, the optical glass with the light absorption layer has a thickness of 0.2 to 0.7 mm.

By the technical scheme, the optical glass with the light absorption layer and the preparation method thereof provided by the invention at least have the following advantages:

1. the preparation method of the optical glass with the light absorption layer provided by the invention mainly comprises the following two steps: firstly, carrying out high-pressure treatment in a high-pressure reducing atmosphere to ensure that reducing gas is more fully and fully diffused and permeated on the surface layer of the optical glass; then, high-temperature reduction is performed in a mixed atmosphere of a reducing gas and nitrogen, and the surface layer of the optical glass permeated with the reducing gas is easily subjected to a reduction reaction at high temperature, so that the optical glass having the light absorbing layer is obtained. The preparation method separately carries out high-pressure treatment and high-temperature treatment, firstly, the requirements on equipment are reduced, the requirements on high temperature and high pressure do not need to be met simultaneously, and the problem that the high temperature and high pressure are difficult to reach simultaneously due to the limitation of the material of a furnace body is solved; and secondly, the problem that the light absorption layer is difficult to prepare in the optical glass with a compact structure is solved.

2. The optical glass prepared by the method has a self-substrate light absorption layer, and the light absorption efficiency of the light absorption layer is detected to be more than 99 percent, so that the optical glass reduces the optical crosstalk caused by the optical glass. Because the light absorption layer is generated by the reduction reaction of the optical glass from the substrate, the absorption layer and the base glass are originally integrated, the interface reflectivity between the light absorption layer and the optical glass base is less than 1 percent, the interface reflection is prevented, and the problem of falling off after being heated or receiving external acting force does not exist, thereby being more suitable for practical use.

3. The method of the invention can be suitable for most brands of optical glass on the market, and particularly for high-density optical glass, the technical problem that the surface layer of the high-density optical glass is difficult to restore is solved.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings.

Drawings

Fig. 1 is a schematic view showing an optical glass having a light absorbing layer according to an embodiment of the present invention;

FIG. 2 is a schematic view showing an external structure of a high-pressure furnace according to an embodiment of the present invention;

FIG. 3 is a schematic sectional view showing a high-pressure furnace according to an embodiment of the present invention;

fig. 4 is a schematic view showing an external structure of a high temperature reduction furnace according to an embodiment of the present invention;

fig. 5 is a schematic cross-sectional view of a high temperature reduction furnace according to an embodiment of the present invention.

Detailed Description

To further illustrate the technical means and effects of the present invention adopted to achieve the predetermined objects, the following detailed description of the optical glass with a light absorption layer and the preparation method thereof, the structure, the features and the effects thereof according to the present invention will be made with reference to the accompanying drawings and the preferred embodiments. In the following description, different "one embodiment" or "an embodiment" refers to not necessarily the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

As shown in fig. 1, a method for manufacturing an optical glass having a light absorbing layer according to an embodiment of the present invention specifically includes the following steps:

and step S1, putting the optical glass to be processed into a high-pressure furnace, introducing sufficient high-pressure reducing gas into the high-pressure furnace to keep the pressure in the high-pressure furnace between 0.5MPa and 100MPa, and carrying out high-pressure processing at the normal temperature of about 25 ℃, preferably at the temperature of 20-30 ℃ for 1-2h, so that the reducing gas is fully diffused or permeated on the surface layer of the optical glass under the action of high pressure.

For the same optical glass, the higher the pressure, the longer the high-pressure treatment time, and the deeper the depth to which the reducing gas diffuses or penetrates into the surface layer of the optical glass, the higher the concentration, at a certain temperature, and the pressure and the high-pressure treatment time can be determined according to the desired thickness of the light absorbing layer. For different kinds of optical glass, the pressure can be selected according to the compactness of the optical glass, and the higher the compactness, the higher the pressure is selected, such as green sheet glass Soda-lime (0.5-10MPa), D236T, B270(0-50MPa), Borofloot, Eagles200(50-100MPa) and the like.

In step S1, the optical glass to be treated contains metal ions, in the optical glass, the metal ions are mostly present in the form of oxides, and the oxides of the metal ions are colorless and have no light absorbing property; meanwhile, the metal ion oxide is easy to reduce to form a metal simple substance, and the formed metal simple substance can stably exist and has good light absorption performance. The metal ions in this embodiment include, but are not limited to, silver ions and copper ions, and in a reducing atmosphere, the metal ions are reduced to a simple metal, and the optical glass containing the simple metal can absorb stray light, and can also shield external stray light to prevent the stray light from affecting the performance of the optical glass. The reducing gas is selected from gases having reducing properties, and the present invention does not limit the kind of the reducing gas as long as reduction of relevant components in the optical glass can be achieved, and the reducing gas includes, but is not limited to, H₂CO and CH₄At least one of (1).

In some embodiments, the structure of the high-pressure furnace is as shown in fig. 2 and 3, which are respectively an appearance structure schematic diagram and a cross-sectional structure schematic diagram of the high-pressure furnace, the high-pressure furnace includes a high-pressure furnace body 21, which is a high-pressure cavity, for performing high-pressure treatment on the optical glass 1 to be treated, the high-pressure furnace body 21 is disposed on a base 22, the high-pressure furnace body 21 is provided with an air inlet 24 for introducing required high-pressure reducing gas, and the high-pressure furnace body 21 is provided with a reinforcing hoop 23, so that the high-pressure. In order to discharge the interference of gases such as oxygen in the air, before introducing the high-pressure reducing gas, the high-pressure furnace body is vacuumized.

And S2, sending the optical glass processed in the step S1 into a high-temperature reduction furnace, introducing mixed gas of reducing gas and nitrogen at a certain pressure as heating protective gas, raising the temperature to be between Tg and Tf of the optical glass, and performing high-temperature reduction treatment for 1-2 hours.

In step S2, the pressure of the treatment is not required to be controlled intentionally, and may be set to 0.1 to 1MPa, for example, 1 atm (101.325 kPa). In the mixed atmosphere of the reducing gas and the nitrogen, the volume ratio of the reducing gas to the nitrogen is 1-3: 1, the reducing gas comprises H₂CO and CH₄Preferably the volume ratio of the reducing gas to nitrogen is 1 to 3: 1, more preferably the volume ratio of the reducing gas and nitrogen gas is 1:1, the proportion can reduce the amount of oxygen possibly mixed in during container exchange to the minimum, and simultaneously ensure the safety,

tg is the glass transition temperature of the optical glass; tf is the melting temperature of the optical glass, and the Tg-Tf is in a high-elastic state, so that the reducing gas is favorable for reducing easily reducible substances in the optical glass in the high-elastic state. In some embodiments, the structure of the high temperature reduction furnace is as shown in fig. 4 and 5, which are respectively an appearance structure schematic diagram and a cross-sectional structure schematic diagram of the high temperature reduction furnace, the high temperature reduction furnace includes a high temperature reduction furnace body 31, the high temperature reduction furnace body 31 is sequentially provided with a heating layer 34 and an insulating layer 31 from inside to outside, the optical glass 1 is placed in a furnace chamber of the high temperature reduction furnace body 31, and a sealing cover 33 is further provided on the top of the high temperature reduction furnace body 31.

In the process of transferring the optical glass from the high-pressure furnace in the step S1 to the high-temperature reduction furnace in the step S2, care should be taken to avoid contact with air as much as possible to cause oxidation or excessive escape of hydrogen, so that the optical glass needs to be protected as quickly as possible in the process of transferring the optical glass, and inert gas or nitrogen can be blown into the optical glass all the time to transfer the optical glass under the protection of the inert gas or nitrogen.

And step S3, cooling the optical glass after the second treatment to room temperature in a nitrogen atmosphere to obtain the optical glass with the light absorption layer with the required thickness. The processed optical glass may be cut, ground, and polished as necessary to obtain an optical glass element having a light absorbing layer.

In order to achieve the purpose of using the optical glass, the optical absorption layer of the obtained optical glass needs to be further processed, the reduction process of the optical glass is reduced all around, post-processing is needed, the optical absorption layer in the light-passing area is removed to form a required optical absorption layer at the peripheral part of the optical glass substrate, and the middle part is used for receiving a target optical signal, and two processing methods can be adopted, wherein one method is that before the optical glass is processed, a coating film or a protective adhesive is coated on the optical area of the optical glass so that the optical glass cannot be oxidized at high temperature and high pressure; alternatively, the surface layer of the optical glass is subjected to reduction treatment, after the light absorbing layer is formed on the surface layer of the optical glass, the light absorbing layer in the optical region of the optical glass is polished, and the light absorbing layer on the surface layer is removed by grinding, polishing or the like.

The present embodiment divides the preparation of the light absorbing layer into two steps: firstly, putting optical glass to be processed into a high-pressure-resistant cavity, introducing high-pressure reducing gas into the cavity at normal temperature, and allowing the reducing gas to be fully diffused and permeated on the surface layer of the optical glass under high pressure; then the optical glass which finishes the permeation of the reducing gas is transferred into a high-temperature reducing furnace for high-temperature reduction to generate a light absorption layer, so that the thickness, the quality and the function of the light absorption layer of the optical glass from the substrate are improved. Through the steps of splitting the reducing gas pressurization and the high-temperature reduction, the reducing gas can reach the pressure intensity (limited by the material of the furnace body) which is difficult to reach at high temperature, so that the diffusion and the permeation of the reducing gas on the surface of the optical glass are more sufficient, the preparation of the optical glass self-substrate light absorption layer is realized, the better reduction effect is achieved, and the stray light absorption layer which is more in line with the standard is manufactured. Experiments prove that the preparation method has reasonable theoretical basis and feasible operation process. The method solves the problem that the traditional high-temperature reduction process cannot meet the requirement of preparing the light absorption layer in the optical glass with a compact structure.

According to the basic principle of glass technology, glass is an amorphous material and has a net structure, and is characterized by short-range order and long-range disorder, so that more dangling bonds, particularly non-bridging oxygen positions, exist among atoms in the amorphous glass. Therefore, small molecules or atoms of the reducing gas can gradually diffuse into the glass interior to undergo redox reactions with the ions. Therefore, the mass concentration of the metal simple substance reduced by the metal ions of the glass decreases from the surface layer to the inside in order, and the metal simple substance concentration on the surface is the largest.

According to the diffusion reaction kinetics, the depth of the reducing gas entering the glass depends on the reduction treatment conditions, the pressure, the temperature and the time have an influence on the depth of the reducing gas entering the glass, the greater the pressure, the greater the depth of the reducing gas entering the glass, and the thicker the glass containing the reduced metal; the higher the temperature, the greater the depth of the reducing gas into the glass, and the thicker the thickness of the glass containing the reduced metal; also, the longer the time, the greater the depth of the reducing gas into the glass, and the greater the thickness of the reduced metal containing glass, so that the pressure, temperature and time can be controlled to control the thickness of the reduced metal containing glass.

According to the thermodynamic principle of redox reaction, the reduction temperature cannot be too low and is lower than the Tg of glass, the activation energy of the reduction reaction is insufficient, so that the redox reaction cannot occur or the occurrence rate is extremely low, and metal ions cannot be reduced into metal simple substances; the reduction temperature is not too high and is higher than Tf of the glass, on one hand, higher temperature is easy to cause surface defects such as deformation, chap and the like of the glass surface, and on the other hand, higher temperature also causes volatilization, agglomeration and the like of the generated metal simple substance to influence the light absorption effect.

In the process of the reduction treatment, the conditions of the reduction treatment are controlled to reduce enough metal ions so that the metal ions on the outer surface are reduced, the reduced metal or alloy has the light absorption effect, and meanwhile, the reduction treatment is controlled so that the excessive metal ions cannot be reduced, so that the thickness of the glass containing the reduced metal is too thick, and the optical performance of the whole structure is influenced. Therefore, it is necessary to select the conditions for the reduction treatment according to actual needs.

The light absorption layer obtained by the method has the property of absorbing light, and the reaction probably occurring in the reduction process is mainly that the optical glass contains easily reduced components, such as silver oxide, and after the reduction treatment, metal ions are reduced into a metal simple substance, and the metal simple substance has the property of absorbing light. Because most of optical glass has higher compactness, the reduction reaction gradually weakens from the surface layer of the optical glass to the inside, the surface layer of the optical glass is strongest, and the condition of light absorption can be met as long as the light absorption rate of the outermost light absorption layer is more than 99%.

In principle, the process is suitable for most brands of optical glass on the market, and other types of non-optical special glass can be used for manufacturing functional layers which are more durable or meet various other standards, so that the glass is multifunctional.

As shown in fig. 1, another embodiment of the present invention provides an optical glass having a light absorbing layer, including: the optical glass comprises an optical glass matrix 1 and a light absorption layer 2, wherein the light absorption layer 2 is a self-substrate light absorption layer.

The self-substrate light absorption layer referred to herein means that the light absorption layer is formed by reduction reaction of optical glass from a substrate, and the light absorption layer and the optical glass substrate are integrated. Through reduction treatment of the optical glass, a light absorption layer with the thickness of about 0.1-0.8 mm, preferably 0.2-0.7mm, is generated on the surface of a non-light-transmitting area of the optical glass, and the light absorption layer with the thickness can meet the light absorption effect, is easily obtained through reduction reaction of the optical glass from a substrate, and does not occupy too much optical area. The light absorption layer and the optical glass substrate are of an integrated structure, and the problem of falling off caused by heating or external acting force does not exist. Meanwhile, the interface reflectivity between the light absorption layer and the optical glass substrate can be kept below 1 percent. The light absorption layer has a light absorption rate of greater than 99%. In some embodiments, the optical glass having a light absorbing layer is prepared according to the above-described method for preparing an optical glass having a light absorbing layer.

In the optical glass prepared by the preparation method, the light absorption layer is generated on the surface of the non-light-transmitting area of the optical glass, metal ions in the light absorption layer are reduced into a metal simple substance, and the metal simple substance has a good light absorption effect so as to absorb the formed stray light; meanwhile, the conditions are controlled to prevent metal ions in the light-passing area from being reduced so as to prevent metal simple substances in the light-passing area from causing light loss; therefore, the invention achieves the purpose of absorbing stray light on the premise of ensuring the light transmission performance of the light transmission area.

The present invention will be further described with reference to the following specific examples, which should not be construed as limiting the scope of the invention, but rather as providing those skilled in the art with certain insubstantial modifications and adaptations of the invention based on the teachings of the invention set forth herein.