JPH0680443A - Method for manufacturing glass optical element - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to a method for manufacturing a glass optical element, which can reliably remove a black thin film of lead or the like and a white turbid minute scratch generated on the surface of a glass optical element hot-press molded. An object of the present invention is to provide a method for manufacturing a glass optical element that can obtain a glass optical element having high transparency and stable characteristics with good yield. In a method of manufacturing a glass optical element molded by hot press molding, the glass optical element after molding is subjected to a physical or chemical treatment to change the element distribution or shape of the surface portion of the glass optical element. A method for manufacturing a glass optical element, comprising:

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a glass optical element used for an optical component or the like, and more specifically, a black thin film of lead or the like or cloudiness produced on the surface of a glass optical element formed by hot pressing. The present invention relates to a method for manufacturing a glass optical element capable of reliably removing minute scratches and obtaining a glass optical element having high transparency and stable characteristics.

[0002]

2. Description of the Related Art Conventionally, a method for manufacturing a glass optical element has been
For example, a hot press molding method of lead-containing flint glass is known. When this flint-based glass is hot-press molded, lead ions, which are the constituent components of the glass, diffuse at the interface with the mold and react with a trace amount of reducing substances such as hydrocarbons present on the mold surface to form metallic lead. This metallic lead corrodes the mold material and causes fusion between the glass and the mold.
For this reason, a black thin film of lead or the like is formed on the surface of the glass molded product, or minute scratches are generated to cause clouding. Thus, if a black thin film, cloudy microscopic scratches, etc. occur on the surface of the glass, there is a drawback that the transmittance is lowered and a glass optical element having desired characteristics cannot be obtained.

Therefore, in order to solve the above problem, there has been a conventional technique disclosed in, for example, Japanese Patent Laid-Open No. 145920/1985. Here, a vapor deposition method is previously performed on the surface of an optical glass element before hot press molding. The antireflection film is formed by the above method. Also, for example, Japanese Patent Publication 4-2160
According to Japanese Patent No. 6, a surface layer portion in which the concentration of easily evaporative components such as lead is lower than that of the glass base material is provided on the surface of the glass base material before hot press molding.

In the conventional method for manufacturing a glass optical element disclosed in Japanese Patent Laid-Open No. 60-145920 and Japanese Patent Publication No. 4-21606, the forming method is different, but both are preliminarily formed on the glass surface before hot press molding. Since the barrier layer is provided, it is possible to make it difficult to deposit lead and the like on the glass surface during hot press molding, and to make it difficult to form a black thin film of lead and the like on the glass surface. In addition, even if white turbidity micro scratches occur in the barrier layer, it is possible to prevent scratches from reaching the base material that determines the optical characteristics.

[0005]

However, in the above-mentioned conventional method for manufacturing a glass optical element in which a barrier layer is provided on the glass surface portion in advance before hot press molding, a black thin film of lead or the like on the hot press surface or optical It is possible to prevent white turbidity minute scratches from occurring on the glass substrate that determines the characteristics, but with the recent demands for severe optical characteristics, the above methods may not be able to adequately meet the requirements, and the yield may deteriorate. There was a problem.

In all of these conventional methods, since the treatment is performed before hot press molding, it is not possible to completely guarantee that after hot press molding. If a white turbid minute scratch occurs, it may not be reused and may be incorporated into the device as it is. Therefore, the present invention can reliably remove the black thin film and white turbidity micro scratches such as lead generated on the surface of the glass optical element molded by hot pressing, and the yield of glass optical elements with high transparency and stable characteristics is high. It is an object of the present invention to provide a method for producing a glass optical element that can be obtained.

[0007]

To achieve the above object, the present invention provides a method for forming a glass optical element molded by hot press molding, wherein the glass optical element after molding is treated physically or chemically. The element distribution or shape of the surface of the glass optical element is changed.

In the present invention, it is preferable that the treated surface of the glass optical element has a thickness of 1000 Å or less. In this case, if the treatment is made thicker than 1000 Å, the treatment proceeds even to the glass substrate that determines the element characteristics of the optical element, and the element characteristics such as the refractive index are deteriorated, which is not preferable. Therefore, if the treatment is performed at 1000 Å or less, only the altered portion of the glass surface portion can be removed or modified (regenerated), and an optical element having better element characteristics can be obtained, which is preferable. Considering the characteristics, the more preferable range of the processed film thickness is 300 Å or more and 500 Å or less.

In the present invention, it is preferable that the physical treatment is carried out by subjecting the glass optical element after molding to ultrasonic treatment in a liquid. In this case, the physical treatment is simply conducted in liquid without ultrasonic treatment. Since it is possible to efficiently heat the glass surface portion rather than the inside of the glass than in the case, it is possible to efficiently remove or modify the deteriorated portion of the glass surface portion. Moreover, the treatment thickness can be controlled by appropriately adjusting the conditions such as ultrasonic treatment.

In the present invention, it is preferable that the physical treatment is carried out by polishing with a member harder than the glass optical element after molding, and in this case, the white turbid minute scratches generated on the glass surface are efficiently removed. can do. The polishing member is preferably fine particles in terms of processing accuracy, and examples of this member include cerium oxide and alumina.

In the present invention, the physical treatment is preferably carried out by reactive dry etching. In this case, the deteriorated layer on the glass surface can be removed with good controllability. The reactive dry etching includes, for example, etching with argon ions and the like, and RIE such as oxygen plasma ashing. In the present invention, the chemical treatment is preferably carried out by a wet treatment with an inorganic or organic acid. In this case, an inorganic acid such as nitric acid or an organic acid such as acetic acid can be used. According to this, it is possible to remove an altered layer or the like on the glass surface portion without causing precipitation of hydrochloride, sulfate or the like that is likely to occur with hydrochloric acid or sulfuric acid.

In the present invention, it is preferable that the chemical treatment is carried out by a wet treatment using a fluorine-containing compound. In this case, a fluorine-containing compound such as hydrofluoric acid can be used. Can be removed efficiently. In the present invention, the chemical treatment is preferably performed by a wet treatment with an inorganic or organic alkali, in which case the constituent elements of the altered portion of the glass surface portion and the constituent elements of the inorganic or organic alkali may be ion-exchanged. Therefore, the altered layer on the glass surface can be removed and modified at the same time. For example, when lead-containing glass is treated with sodium hydroxide as an inorganic alkali, lead and sodium can be ion-exchanged, so the deteriorated layer can be removed together with the removal of lead, and the strength of glass can be improved by adding sodium. The workability can be improved. In addition, diethylamine etc. are mentioned as an organic alkali.

In the present invention, the chemical treatment is preferably a wet treatment with a chelating reagent. In this case, the constituent element ions on the glass surface can be selectively removed. The altered layer and the like can be removed. For example, if lead-containing glass is EDT
When treated with a chelating agent such as A, the lead ions of the constituent elements of the glass surface portion can be selectively removed, and at the same time, the altered layer can be removed.

In the present invention, the chemical treatment is preferably carried out by a wet treatment of immersing in the molten salt. In this case, the constituent element ions of the glass surface portion and the constituent ions of the molten salt are ion-exchanged to obtain a glass surface. It is possible to remove and modify the deteriorated layer and the like at the same time. For example, when lead-containing glass is treated in a molten salt of sodium nitrate, lead and sodium can be ion-exchanged, so that the deteriorated layer can be removed together with the removal of lead, and the strength of glass can be improved by adding sodium. The workability can be improved.

In the present invention, the chemical treatment is carried out by dipping in a solution of a suitable solvent such as water or ethanol, or by treating the solution in a vaporized atmosphere. In this case, the base material that determines the optical characteristics of the glass optical element is less likely to be damaged, and the altered layer and the like can be removed. In the present invention, it is preferable that at least two or more of the physical treatments or chemical treatments be performed simultaneously or successively, and in this case, the scratches formed on the glass surface, the adhesion film of lead, etc. It can be appropriately selected in combination and can be effectively removed, for example.

[0016]

In the present invention, since the element distribution or shape of the surface of the glass optical element can be changed, it is possible to reliably remove the black thin film of lead or the like and the white turbidity micro scratches on the surface of the glass after molding. . Therefore, it is possible to efficiently obtain a glass optical element having desired characteristics with high transparency, such as black or cloudiness. Therefore, it is possible to reuse the deteriorated one after hot press molding.

[0017]

【Example】

(Embodiment 1) Hereinafter, the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating a method of manufacturing a glass optical element according to the first embodiment of the present invention. In FIG. 1, reference numeral 1 is a glass optical element such as lead-containing heavy flint glass hot-press molded into a desired shape, and 2a is a lead thin film formed by deposition of lead on the surface of the glass optical element 1 during press molding. It is a colored (black) layer, and 2b is an opaque layer of minute scratches generated on the surface of the glass optical element 1 during hot press molding.

Next, a method of manufacturing the glass optical element will be described. Here, the method of treating the glass optical element after hot press molding, which is a feature of the present invention, will be specifically described. First, as shown in FIG.
The glass optical element 1 is formed by hot press molding using a mold at 100 ° C. and 100 Kgcm ⁻² for 1 minute (glass type: SF2). At this time, if a large number of glass optical elements 1 are molded, as shown in FIG. 1B, lead is deposited on the surface of the glass optical element 1 to form a colored layer 2a of lead, or minute scratches are formed on the surface of the glass optical element 1. The white turbid layer 2b may occur.

Next, as shown in FIGS. 1 (c) and 1 (d), the glass optical element 1 having the colored layer 2a and the cloudy layer 2b is
The colored layer 2a of lead on the glass surface is removed by oxidation by ultrasonic treatment in M nitric acid for 15 minutes. Then, 1 in a mixed solution of hydrofluoric acid (4M) and nitric acid (1.3M)
By soaking for a minute, the colored layer 2a on the glass surface and the cloudy layer 2b due to minute scratches are efficiently etched. At this time, the etching amount can be appropriately adjusted by appropriately repeating the ultrasonic treatment step in nitric acid and the treatment step in the mixed solution of hydrofluoric acid and nitric acid. Therefore, the colored layer 2a and the cloudy layer 2b generated on the glass optical element 1 can be reliably removed.

Then, the glass optical element 1 from which the colored layer 2a and the cloudy layer 2b are removed is rinsed with pure water and dried to obtain the glass optical element 1 having high transparency. As described above, in the present embodiment, the colored layer 2a and the cloudy layer 2b formed on the glass optical element 1 are subjected to ultrasonic treatment in nitric acid,
By appropriately repeating the treatment in the mixed solution of hydrofluoric acid and nitric acid, it is possible to remove efficiently and surely. Therefore, the glass optical element 1 having high transparency and stable characteristics can be obtained with high yield. Moreover, it is possible to reuse the deteriorated one after the hot press forming.

In the first embodiment, the case where the colored layer 2a formed on the glass optical element 1 is removed by ultrasonic treatment in nitric acid has been described, but the present invention is not limited to this. Treatment with 1 M sodium hydroxide or a 10% EDTA aqueous solution set to an applicable pH value (about 10) may be performed, or exposure to formic acid vapor for 15 minutes may be performed. The same effect can be obtained.

In Example 1, the colored layer 2a formed on the glass optical element 1 by the treatment in the mixed solution of hydrofluoric acid and nitric acid.
Although the case where the cloudy layer 2b and the cloudy layer 2b are removed has been described, the present invention is not limited to this. For example, ultrasonic treatment may be carried out for 15 minutes in an aqueous solution of cerium oxide 7 g / 100 ml. It is possible to obtain substantially the same effect as. In this way, when ultrasonic treatment is performed, Ce (OH) ₄ reaching the surface is activated, and Ce- at the glass surface portion
The formation of the active complex of O—Si can be uniformly promoted, and polishing by ultrasonic vibration of CeO ₂ can be efficiently performed.

(Example 2) In Example 1, the case where the glass optical element 1 in which the colored layer 2a and the cloudy layer 2b were formed was treated was described, but only the colored layer 2a is the glass optical element 1.
If it occurs, the processing may be performed as in this embodiment.
Hereinafter, a specific description will be given with reference to the drawings. FIG. 2 is a diagram illustrating a method of manufacturing a glass optical element according to the second embodiment of the present invention. 2, the same reference numerals as those in FIG. 1 indicate the same or corresponding parts.

Next, a method of manufacturing the glass optical element will be described. Here, a method of treating a glass optical element after hot press molding, which is a feature of the present invention, will be specifically described. First, as shown in FIG.
The glass optical element 1 is formed by hot press molding using a mold at 100 ° C. and 100 Kgcm ⁻² for 1 minute (glass type: SF2). At this time, as shown in FIG. 2B, the glass optical element 1
Lead is deposited on the surface to form the colored layer 2a.

Next, as shown in FIG. 2C, the colored layer 2a
Of the glass optical element 1 in which the occurrence of oxygen is caused by RIE by oxygen plasma
Etching by the method. At this time, the colored layer 2a generated on the glass optical element 1 is removed. As described above, in this embodiment, the colored layer 2a formed on the glass optical element 1 can be efficiently and surely removed by treating the colored layer 2a by RIE using oxygen plasma. Therefore, the glass optical element 1 having high transparency and stable characteristics can be obtained with high yield.

(Example 3) In Example 1, the case where the glass optical element 1 having the colored layer 2a and the cloudy layer 2b was treated was described, but only the colored layer 2a is the glass optical element 1.
If it occurs, the processing may be performed as in this embodiment.
Hereinafter, a specific description will be given with reference to the drawings. FIG. 3 is a diagram illustrating a method of manufacturing a glass optical element according to the third embodiment of the present invention. 3, the same reference numerals as those in FIG. 1 indicate the same or corresponding parts.

Next, a method of manufacturing the glass optical element will be described. Here, a method of treating a glass optical element after hot press molding, which is a feature of the present invention, will be specifically described. First, as shown in FIG.
The glass optical element 1 is formed by hot press molding using a mold at 100 ° C. and 100 Kgcm ⁻² for 1 minute (glass type: SF2). At this time, as shown in FIG. 3B, the glass optical element 1
Lead is deposited on the surface to form the colored layer 2a.

Next, as shown in FIG. 3C, the colored layer 2a.
The colored layer 2a formed on the glass optical element 1 is removed by immersing the glass optical element 1 in which the above occurs in potassium nitrate at 400 ° C. At this time, the colored layer 2a formed by lead on the surface of the glass optical element 1 is removed. Is removed by melting with a potassium nitrate solution (melting of lead) and is removed by exchanging potassium ions in the potassium nitrate solution for lead ions in the colored layer 2a.

As described above, in this embodiment, the colored layer 2a formed on the glass optical element 1 can be efficiently and surely removed by immersing it in the molten salt of potassium nitrate. Therefore, the glass optical element 1 having high transparency and stable characteristics can be obtained with high yield.

[0030]

According to the present invention, a black thin film of lead or the like and white turbid minute scratches formed on the surface of a glass optical element molded by hot pressing can be surely removed, and a glass having high transparency and stable characteristics. There is an effect that an optical element can be obtained with high yield.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a method of manufacturing a glass optical element according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a method of manufacturing a glass optical element according to a second embodiment of the present invention.

FIG. 3 is a diagram illustrating a method of manufacturing a glass optical element according to a third embodiment of the present invention.

[Simple explanation of symbols]

 1 Glass Optical Element 2a Colored Layer 2b Cloudy Layer

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Akito Minato 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Hiroyuki Endo 1-3-6 Nakamagome, Ota-ku, Tokyo Stock company Ricoh

Claims (12)

[Claims] 1. A method of manufacturing a glass optical element molded by hot press molding, wherein the glass optical element after molding is subjected to a physical or chemical treatment to change the element distribution or shape of the surface of the glass optical element. A method for manufacturing a glass optical element, which comprises: 2. The method for manufacturing a glass optical element according to claim 1, wherein the treated thickness of the surface portion of the glass optical element is 1000 Å or less. 3. The method for producing a glass optical element according to claim 1, wherein the physical treatment is performed by subjecting the glass optical element after molding to ultrasonic treatment in a liquid. 4. The method for producing a glass optical element according to claim 1, wherein the physical treatment is performed by polishing with a member harder than the glass optical element after molding. 5. The method for manufacturing a glass optical element according to claim 1, wherein the physical treatment is performed by reactive dry etching. 6. The method for manufacturing a glass optical element according to claim 1, wherein the chemical treatment is performed by a wet treatment with an inorganic or organic acid. 7. The chemical treatment is performed by a wet treatment using a fluorine-containing compound.
A method for manufacturing the glass optical element as described above. 8. The method of manufacturing a glass optical element according to claim 1, wherein the chemical treatment is performed by a wet treatment with an inorganic or organic alkali. 9. The method for manufacturing a glass optical element according to claim 1, wherein the chemical treatment is a wet treatment with a chelating reagent. 10. The method for manufacturing a glass optical element according to claim 1, wherein the chemical treatment is performed by a wet treatment of immersing in a molten salt. 11. The glass according to claim 1, wherein the chemical treatment is performed by immersion treatment in a solution with an appropriate solvent or by treating the solution in an atmosphere of steam. Optical element manufacturing method. 12. At least two of the physical treatment or the chemical treatment.
The method for manufacturing a glass optical element according to claim 2, wherein one or more treatments are performed simultaneously or successively.