JP3382999B2 - Optical element and method of bonding the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical element made of glass which is used for bonding other than an optically effective surface, and a method for bonding the same.

[0002]

2. Description of the Related Art Conventionally, adhesives such as balsam, epoxy type, acrylate type ultraviolet curing type, and cyanoacrylate type instant adhesive have been used for bonding optical elements used in optical systems. However, recently, a highly accurate optical system has been required in the optical technical field, and an optical system using an adhesive having a high elasticity or flexibility and having an extremely small optical distortion has been proposed. For example, JP-A-59-1354
No. 06 and Japanese Patent Laid-Open No. 59-228615 disclose a technique of bonding a lens to a holding frame using an adhesive having a low elastic modulus (high flexibility and high elasticity). Further, Japanese Patent Application Laid-Open No. 2-173718 discloses an adhesive technique using a silicone adhesive as a specific adhesive.

On the other hand, in the optical system, it is also necessary to hold the optical element with sufficient strength. Therefore, as disclosed in Japanese Patent Laid-Open No. 1-277208, the adhesive is extruded and Is disclosed as a structural part, or as disclosed in Japanese Patent Laid-Open No. 63-11550, a technique for enhancing the adhesiveness by performing a surface treatment with a silane coupling agent or the like is disclosed. In addition, irregular reflection of light on the surface to which the optical element is adhered causes flare and the like, which significantly deteriorates the optical characteristics. On the other hand, black coating is applied to the end surface of the optical element, which is called edge coating.

[0004]

However, some optical glass materials have extremely poor adhesiveness, and the adhesiveness is S
Depends on the content of metal oxides such as iO ₂ and Al ₂ O ₃ ,
The glass material containing less metal oxide has poorer adhesion. Therefore, fluorite, a glass material made of a fluoride, or a glass material such as a lanthanum glass material having a very small amount of SiO ₂ and other metal oxides may not be sufficiently adhered and held. Silicone-based adhesives are particularly suitable for bonding optical elements because of their high flexibility, but because chemical bonding with metal oxides is extremely important for developing adhesiveness with glass. However, it is difficult to hold the glass materials having low adhesiveness as mentioned above.

Further, when an adhesive is used as a structural material as described in JP-A-1-277208, the adhesive itself needs to have a high elastic modulus and is not suitable for optical adhesion.

On the other hand, in the surface treatment with a silane coupling agent, one functional group of the silane coupling agent reacts and bonds with the resin or the adhesive, and the other functional group chemically bonds with the glass for adhesion. However, in reality, among the components of the glass, since it is bonded to a metal oxide such as SiO ₂ which is usually contained in a large amount and exhibits adhesiveness, as described above, It has been confirmed that the surface treatment effect on glass having low adhesiveness is extremely low.

[0007] Such low adhesiveness is not only a problem in the adhesive step, but also a cause of deterioration in the adhesiveness of the edge coating paint or the like as a countermeasure against flare due to diffused reflection on the lens end face or the like.

The present invention has been made in view of the above problems, and an optical element and a bonding method therefor capable of increasing the adhesiveness even in a glass material having low adhesiveness and preventing diffuse reflection on the adhesive surface. The purpose is to provide.

[0009]

The optical element of the present invention is an optical element made of glass which is used for bonding other than the optically effective surface, and a pigment and at least silicon oxide or metal oxide are formed on a part or all of the surface used for bonding. The method of the present invention is a method for adhering an optical element in which a surface other than an optically effective surface is used for adhesion, and a pigment and a part of the surface used for adhesion are used. A step of applying a solution containing at least an organic silicon compound or an organic metal oxide and heating it to form a coating film containing a pigment and at least silicon oxide or a metal oxide; and an adhesive contacting at least the coating film. As described above.

As a solution containing an organosilicon compound,
For example, a solution comprising a silylisocyanate compound, a chlorosilane compound, perhydropolysilazane, and the like, and a solution of an organometallic compound, for example, an aluminum alcoholate compound, an aluminum chelate compound, an aluminum organic compound such as a cyclic aluminum oligomer, an alumina sol, A solution containing a titanate compound, a Zr alcoholate compound, or the like is used. As a coating method, for example, brush coating, dropping, spin coating, spraying or the like is used. As the adhesive, a solvent-eliminating type, a moisture-curing type, a UV-curing type or the like made of a silicone type, an acrylate type, an epoxy type or the like is used.

The target glass material contains a small amount of metal oxide such as YGH51, fluorite, PBH50, or the like.
Application to a glass material that does not contain it at all is particularly effective in improving the adhesive strength. In addition, as a pigment to be added to prevent irregular reflection of light, a black one is generally used.
Carbon particles or the like are used. As the target optical element, for example, a lens, a lens array, a filter,
It can be applied to prisms, glass mirrors, inorganic optical fibers and the like.

[0012]

According to the above-mentioned means, the organosilicon compound or the organometallic compound containing the pigment is heated after being applied to a portion other than the optically effective surface of the substrate, that is, the optical element, and the adhesive surface or a portion where diffuse reflection is desired to be prevented. Thus, a coating film made of silicon oxide containing a pigment or a metal oxide firmly adhered to the substrate is formed. In particular, if the base material contains even a small amount of the metal oxide, when the organosilicon compound or the organometallic compound reacts, it also binds to the metal compound of the base material, and the base material and the coating film become extremely strong. In close contact.

[0013] and thus obtained coating film, a silane coupling agent or silicone adhesive, the silanol groups (-Si-OH) produced during the reaction, a coating film made of the metal oxide, such as SiO ₂ Present on the surface of Si
-OH group and -Si-O-Si by dehydration condensation reaction
A strong chemical bond is formed to firmly adhere. Therefore, in terms of adhesion, a metal oxide composed of Si, Al, Pb, Ti, Zr, Ca, Ba, etc. plays an extremely large role.

As in the above means, by providing a coating film of a metal oxide on at least a part or the entire surface of the optical element used for bonding, the adhesiveness of that part can be enhanced, and the adhesion of the adhesive can be improved. It is possible to improve the sex. Moreover, since the pigment is added to the solution containing the organosilicon compound or other organometallic compound, it is not necessary to apply the edge coating afterwards, and the adhesiveness can be improved and the diffused reflection can be prevented in one step. An optical element can be obtained.

[0015]

First Embodiment (Structure) FIG. 1 shows a means for providing a film on the end surface of a lens. In the figure, reference numeral 1 is a lens made of LAL61 (manufactured by Ohara Optical Co., Ltd.) (metal oxide content is 30% or less), and reference numeral 3 is an organometallic compound, here tetraisocyanate silane (Si (NCO) ₄ ). A brush diluted with ethanol and containing a solution containing 10% of carbon particles as a pigment. In this method, while holding the lens 1 rotating as shown in the drawing, the solution is applied to the end surface of the lens by the brush 3 and then heated at about 200 ° C. As a result, as shown in FIG. 2, the coating film 2 made of SiO ₂ containing carbon is formed on the lens end surface. The lens 1 thus obtained was bonded to the lens frame 4 as shown in FIG. Silicone adhesive 5 "KE
66 "(manufactured by Shin-Etsu Chemical Co., Ltd.) was used for positioning and temporary curing at room temperature and normal humidity for 1 day, and left for 1 week for main curing.

(Operation / Effect) Since the lens 1 has excellent adhesiveness on the end surface used for bonding, when the lens 1 is bonded to the lens frame 4, the lens 1 is firmly bonded to the lens frame 4 as shown in FIG. Since a silicone-based adhesive having high flexibility can be used as the adhesive, it is possible to prevent the occurrence of optical distortion. Since this film 2 contains carbon, it has the same function as an edge coating film as a countermeasure against flare due to diffused reflection on the lens end surface. Therefore, it is possible to perform the process in one step including post-processing while improving the adhesiveness, and it is possible to improve the function and reduce the cost by omitting the step.

[0017]

Second Embodiment (Structure) As the lens 1 in FIG. 1, LAH66 (Ohara Optical Co., Ltd.)
Made of (made of metal oxide about 30%),
As the brush 3, an organometallic compound "Tonen Polysilazane PHP-2" (manufactured by Tonen KK) was used as the brush 3 in a polymer concentration of 20.
A brush was used in which a solution prepared by adding 5% of carbon particles as a pigment was added to a solution diluted with xylene so as to be 10%. Then, while the lens 1 is rotated and held as shown in the same figure, after the solution is applied to the end surface of the lens by the brush 3,
The heating is performed at about 200 ° C to 400 ° C. As a result, as shown in FIG. 2, the lens 1 having the film 2 including SiO ₂ and carbon particles and having a good light-shielding property and a good adhesive property is formed on the lens end face. The lens thus obtained was bonded to the lens frame 4 as shown in FIG. A silicone-based adhesive “KE66” (manufactured by Shin-Etsu Chemical Co., Ltd.) was used for adhesion.

(Operation / Effect) Similar to the first embodiment, in the lens 1, not only the end face used for adhesion has excellent adhesiveness, but also the obtained coating film 2
Has the same function as an edge coating film as a countermeasure against flare due to diffused reflection on the end surface of the lens, and has high adhesion to the substrate. Therefore, it is possible to perform the process in one step including post-processing while improving the adhesiveness, and it is possible to improve the function and reduce the cost by omitting the step.

Although carbon was used as the pigment to be added in the present embodiment, titanium oxide and other inorganic or organic pigments can be used according to the purpose, and they can be mixed. It is also possible to use it.

[0020]

Third Embodiment (Structure) FIG. 4 shows means for providing a film made of a metal oxide on the lens end surface. In the figure, reference numeral 1 is LAL6
A lens made of 1 (manufactured by OHARA OPTICS CO., LTD.), Reference numeral 7 is an organometallic compound, here "NT-L2003" (manufactured by NISSAN CHEMICAL INDUSTRIES CO., LTD.) Solution, and 10% carbon particles as a pigment.
It is a syringe filled with the added solution 6. Then, as shown in the figure, while holding the lens 1 rotating, the solution is dropped onto the lens end surface by the syringe 7, the solution is applied only to the outer peripheral portion, and then heating is performed at about 300 ° C. As a result, the lens 1 having the coating film 2 made of SiO ₂ containing carbon and having excellent adhesiveness is formed on the lens end face (FIG. 5). The lens thus obtained was adhered to the lens frame 4 as shown in FIG. Silicone adhesive "KE66" (manufactured by Shin-Etsu Chemical Co., Ltd.) was used for adhesion.

(Operation / Effect) The effect is similar to that of the first embodiment. Also, the syringe 7
In addition, if a dispensing unit that is generally commercially available is used in combination, it is possible to cope with the automation of the coating operation.

[0022]

Fourth Embodiment (Structure) FIG. 6 shows a means for providing a film made of a metal oxide on the end face of a prism. In FIG. 6, reference numeral 8 is LA.
H66 (Ohara Optical Co., Ltd.) (Metal oxide content 30
%), And the reference numeral 6 is an organometallic compound, here mono SEC butoxyaluminum diisopropylate ((CH ₃ ) ₂ CHCH ₂ —O—Al (O—CH).
A container was filled with a solution prepared by adding 10% of carbon particles as a pigment to a 10% solution of (CH ₃ ) ₂ ) in n-hexane. Then, as shown in the figure, the end surface used for bonding the prism 8 is dipped in the container and then heated at about 200 ° C. to form the coating film 2 containing Al ₂ O ₃ . As a result, the prism 11 having the coating film 2 made of alumina containing carbon and having good adhesiveness is obtained on the prism end surface (FIG. 7). Prism 1 thus obtained
1 was adhered to the holding table 10 as shown in FIG. Silicone adhesive "KE66" (manufactured by Shin-Etsu Chemical Co., Ltd.) was used for adhesion.

(Operation / effect) This is similar to the first embodiment.

[0024]

Fifth Embodiment (Structure) The lens material used, the organometallic compound solution, and the method of applying the solution are the same as in the first embodiment. The silane coupling agent “KB” is applied to the end surface of the lens 1 thus obtained.
A 3% ethanol diluted solution of "M-503" (manufactured by Shin-Etsu Chemical Co., Ltd.) is applied and heat-treated at 80 ° C. for 10 minutes, and then adhered to the lens frame 4 as shown in FIG. A urethane acrylate-based UV curable resin was used as the adhesive 5, and after the resin was injected into the gap between the lens 1 and the lens frame 4, the resin was cured by irradiating ultraviolet rays from above in the figure.

(Operation / Effect) The same as in the first embodiment, but S containing carbon is also obtained by a resin adhesive having low adhesiveness to glass.
Since the effect of improving the adhesiveness of the coupling agent to the iO ₂ film is high, it is possible to sufficiently hold and fix the lens 1.

Although the embodiments of the present invention made by the present inventor have been described above, the present invention is not limited to the embodiments and various modifications can be made without departing from the scope of the invention. .

For example, the target glass material is not particularly limited, but may be YGH51, fluorite, PBH50, etc.
Application to a glass material containing a small amount of metal oxide or containing no metal oxide is particularly effective in improving the adhesiveness with an adhesive. The target optical element can be applied to a lens, a lens array, a filter, a prism, a glass mirror, an inorganic optical fiber, or the like. The application method is brush painting,
Dropping, spin coating, spraying, etc. are possible. Adhesives are not limited to those used in the examples, and almost all adhesives are effective, but it is preferable to use silicone-based, acrylate-based, urethane acrylate-based, epoxy acrylate-based, epoxy-based, etc. Yes, solvent removal type, moisture curing type, UV curing type, heat curing type, EB curing type,
Any of anaerobic curing type and the like can be used. Further, it is needless to say that an antireflection coating, a mirror coating, etc. can be formed on the optically effective surface of the optical element by a method such as vapor deposition and sputtering regardless of whether the contents of the present invention are carried out.

[0028]

As described in the above embodiments, according to the present invention, it is possible to prevent diffuse reflection in a portion used for bonding while improving the adhesiveness of the portion used for bonding even in a glass material having low adhesiveness. A possible optical element can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic view of means for providing a coating film on an end surface of a lens.

FIG. 2 is a diagram showing a part of a lens having a coating film formed thereon.

FIG. 3 is a diagram showing a bonded state of a lens.

FIG. 4 is a diagram showing a method for forming a coating film with a syringe.

FIG. 5 is a diagram showing a lens having a coating film formed by a syringe.

FIG. 6 is a diagram showing a method of forming a coating film on a prism.

FIG. 7 is a diagram showing a prism on which a coating film is formed.

FIG. 8 is a diagram showing a method of adhering a prism having a coating film formed thereon.

[Explanation of symbols]

1 lens 2 coating film 4 mirror frame 5 adhesive

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Claims (2)

(57) [Claims] 1. An optical element made of glass used for bonding other than an optically effective surface, wherein a coating film containing a pigment and at least silicon oxide or metal oxide is provided on part or all of the bonding surface. An optical element characterized by. 2. A method for adhering an optical element using a surface other than an optically effective surface for adhesion, wherein a solution containing a pigment and at least an organosilicon compound or an organometallic compound is applied to a part or the entire surface used for adhesion and heated. And a step of providing a coating film containing a pigment and at least silicon oxide or a metal oxide, and a step of adhering the coating film so that the adhesive comes into contact with the coating film. Method.