JP2021140019A - Optical element and manufacturing method therefor - Google Patents

Abstract

To provide a light-shield film and optical element for suppressing deterioration in optical performance even when dealing with complicated optical glass.SOLUTION: An optical element having a light shield film provided on at least a part of an outer periphery of a base material is provided, the light shield film comprising an epoxy resin, a resin containing at least coumarone or indene, and a dye.SELECTED DRAWING: Figure 2

Description

The present invention relates to a light-shielding film, an optical element, and a method for manufacturing an optical element used in an optical device such as a camera, binoculars, and a microscope.

The light-shielding film used for an optical element is a coating film mainly formed on the surface of glass. The optical element may be a lens, a prism, or other optical glass, but the light-shielding film will be described below using a lens as an example.

As shown in FIG. 1, the light-shielding film 1 of the optical element is formed on the outer peripheral portion of the lens 2. When the light hits only the lens 2 like the incident light 3, it is transmitted as the transmitted light 4. On the other hand, when the incident light 5 is incident from an oblique angle, the light hits the light-shielding film 1. At this time, if the light-shielding film 1 is not formed (lower side of the lens in FIG. 1), the light 5 that hits the outer periphery of the lens 2 is internally reflected and the light 6 that is internally reflected and has nothing to do with the image is the lens 2. It goes out and causes flare and ghosts, resulting in poor image quality. By providing the light-shielding film 1 (upper side of the lens in FIG. 1), it is possible to reduce the internal reflection of the incident light 5 from an angle, so that the internal reflected light 6 which adversely affects the image is reduced, and flare and ghost are prevented. It is possible to do.

Optical elements used in optical systems have become more compact and have higher performance in recent years, and optical elements having a more complicated shape are used, and a light-shielding film is also formed into a complicated shape.

Patent Document 1 discloses a light-shielding film for an optical element that reduces internal reflection by absorbing light with a dye.
Patent Document 2 contains (A) epoxy resin, (B) amine-based curing agent, and (C) hydroxyl group-containing kumaron resin, and the hydroxyl group-containing kumaron resin is used in an amount of 1 to 500 parts by weight based on 100 parts by weight of the epoxy resin. Provided is an anticorrosion coating composition characterized by being contained in an amount of, which is excellent in seawater resistance and can form a light-colored coating film such as gray, and can also be used for surface coating of underwater pipelines and the like. In particular, the present invention relates to an anticorrosion coating composition which is useful for painting the inside of a ship such as a ballast tank.

Japanese Unexamined Patent Publication No. 2011-186437 International Publication No. 2007/129564

In the light-shielding film described in Patent Document 1, as shown in FIG. 3A, for example, when a light-shielding film is formed on an optical element having a ridge line 12 as a complicated shape, a phenomenon 13 in which the light-shielding paint moves during drying occurs. It occurs and the film thickness of the ridge line portion decreases as shown in FIG. 3 (b). Further, in the ridge line portion, not only the film thickness of the coating film is thinned, but also a phenomenon that the concentration of the dye for absorbing light decreases occurs, and it is difficult to obtain sufficient light-shielding performance. The dye is relatively small in size among the components in the light-shielding paint and moves at high speed in the paint component, so that the dye selectively moves from the ridgeline portion.

The present invention has been made in view of such a background technique, and even when a light-shielding film is provided on the base material of an optical element having a complicated shape, the optical property suppresses internal reflection and has good optical characteristics. It provides an element.

The optical element of the present invention is an optical element in which a light-shielding film is provided on a part of the outer peripheral portion of the base material, and the light-shielding film is an epoxy resin, at least a resin having kumaron or indene (hereinafter, "Kumaron-inden"). It is also referred to as "based resin"), and is characterized by having a dye.

The method for manufacturing an optical element of the present invention is a method for manufacturing an optical element in which a light-shielding film is provided on a part of the outer peripheral portion of the base material, and is a step of applying a light-shielding paint to the outer peripheral surface of the base material. It is characterized by having a step of curing the applied light-shielding paint to produce a light-shielding film.

According to the present invention, it is possible to provide an optical element having good optical characteristics for suppressing flare and ghost, a light-shielding film made of a light-shielding paint, and a method for manufacturing the optical element even in an optical glass having a complicated shape.

It is a schematic diagram which showed the progress of the light of the inner surface reflected light. It is a schematic diagram which shows the light-shielding film of the optical element of this invention. It is a schematic diagram which shows the movement of a light-shielding paint at the time of paint drying. It is a schematic diagram which shows the measuring method of the inner surface reflection.

Hereinafter, preferred embodiments of the present invention will be described.
The light-shielding film made of a light-shielding paint used for the optical element of the present invention can provide an optical element having a sufficient internal reflection reduction function even in an optical glass having a complicated shape.

Hereinafter, the internal reflection of the optical element will be described. Next, the configuration of the light-shielding film according to the present invention will be described. Next, a method for manufacturing a light-shielding paint, a light-shielding film, an optical element, a light-shielding film, and a method for manufacturing an optical element according to the present invention to achieve them will be described.

[Internal reflection of optical element]
First, the transmitted light 10 of the optical element will be described with reference to FIG. The internal reflection of the optical element mainly occurs at the two interfaces 7 and 8. That is, the incident light 3 passes through the base material (lens) 2 and partially becomes the first reflected light 9 at the interface 7 between the base material (lens) 2 and the light-shielding film 1. The transmitted light 10 transmitted through the light-shielding film 1 is attenuated by the light-shielding film 1 and then becomes the second reflected light 11 at the interface 8 between the light-shielding film 1 and the air.

The first reflected light 9 can be reduced by bringing the refractive indexes of the light-shielding film 1 and the base material (lens) 2 close to each other. The reason why the internal reflection decreases when the refractive index is brought closer is that the refractive index R at the interface between the light-shielding film 1 and the lens 2 is the refractive index n _{0 of the lens 2 on the incident light 3 side, as shown in the following equation (1).} This is because it is determined by the difference in _{the refractive index n 1} of the light-shielding film 1, and the smaller the difference, the smaller the difference.

Further, the second reflected light 11 can be reduced by absorbing the transmitted light 10 transmitted through the light-shielding film. In order to efficiently absorb the transmitted light 10 into the coating film, it is preferable to include a colorant in the light-shielding film 1 to increase the blackness of the film.

[Characteristics of the light-shielding film of the optical element of the present invention]
As shown in FIG. 3A, the light-shielding film 1 of the optical element of the present invention prevents the selective movement of the dye due to the movement of the light-shielding paint even when the optical element has a ridge line 12. By doing so, it is possible to suppress a decrease in the dye concentration at the ridgeline portion.

In order to suppress the reduction of the dye concentration even when the optical element has a ridge line 12, the light-shielding film 1 according to the present invention is at least an epoxy resin or dye cured with an amine-based curing agent. And at least one type of kumaron-inden resin. In the present specification, the kumaron-inden resin is a resin having at least kumaron or indene, and is a kumaron and inden resin, a kumaron resin, or an inden resin. Kumaron and indene resins are resins containing kumaron and inden as main monomer components constituting the skeleton (main chain) of the resin, and styrene and the like are other monomer components contained in the skeleton in addition to kumaron and inden. Can be mentioned. The kumaron resin is a resin containing kumaron as a main monomer component constituting the skeleton (main chain) of the resin. The indene resin is a resin containing indene as a main monomer component constituting the skeleton (main chain) of the resin. Kumaron and indene resins are preferable because of their availability.

(Technical Kumaron-Inden resin effect)
In Patent Document 2, kumaron-indene resin is used for imparting coating film strength and corrosion resistance. However, the present inventors have found that the addition of the kumaron-indene resin suppresses the movement of the dye in the drying step of the light-shielding paint. Since the kumaron-indene resin is a resin mainly composed of kumaron and indene consisting of a five-membered ring and a six-membered ring, the molecule is very bulky and the movement of a dye having a relatively small molecular size can be suppressed. I can guess. Further, since Kumaron and Inden have good compatibility with the dye, it was found that the dye can be dispersed in the entire light-shielding paint and the movement can be suppressed. Therefore, the movement of the light-shielding paint during painting can suppress the selective movement of the dye in the portion where the film thickness is reduced. As a result, it was found that the dye concentration did not decrease even in the portion where the film thickness of the light-shielding film was decreased, and the internal reflection could be effectively suppressed.

[Light-shielding paint]
Next, the material composition of the light-shielding paint for forming the light-shielding film for the optical element of the present invention will be described. Hereinafter, unless otherwise specified, the content of each material used in the light-shielding paint is described with respect to the light-shielding paint containing a curing agent.

The light-shielding coating material according to the present invention has an epoxy resin, a kumaron-indene resin, a dye, and an amine-based curing agent.

The viscosity of the light-shielding coating material according to the present invention is preferably 20.0 mPa · s or more and 65.0 mPa · s or less, and more preferably 30.0 mPa · s or more and 50.0 mPa · s or less. If the viscosity of the light-shielding paint is less than 20 mPa · s, the viscosity becomes too low and the paint easily moves during drying, resulting in poor coatability. On the other hand, if the viscosity of the light-shielding paint exceeds 65.0 mPa · s, the leveling property at the time of application deteriorates, and the obtained light-shielding film has poor appearance such as streaks and unevenness.

Next, each material contained in the light-shielding paint according to the present invention will be described.
(Epoxy resin)
The epoxy resin contained in the light-shielding coating material according to the present invention includes bisphenol A type, bisphenol F type, polyfunctional epoxy resin, flexible epoxy resin, brominated epoxy resin, glycidyl ester type epoxy resin, polymer type epoxy resin, and biphenyl. It is possible to use a type epoxy resin. One type of epoxy resin may be used alone, or a plurality of types may be mixed and used.

The content of the epoxy resin contained in the light-shielding paint according to the present invention is preferably 5.0% by mass or more and 25.0% by mass or less in the light-shielding paint. If the content of the epoxy resin is less than 5.0% by mass, the resin component in the light-shielding paint is small, so that the solvent resistance is lowered. Further, when the content of the epoxy resin exceeds 25.0% by mass, the refractive index is lowered and the internal reflection becomes large.

(Kumaron-Inden resin)
Since the kumaron-inden resin contained in the light-shielding coating material according to the present invention is a polymer using at least one of kumaron and inden, it may be a kumaron resin alone or an inden resin alone. Kumaron and indene resins are preferable because of their availability.

The content of the kumaron-indene resin is preferably 100 parts by mass or more and 300 parts by mass or less with respect to 100 parts by mass of the epoxy resin. If the content is less than 100 parts by mass, the effect of suppressing the movement of the dye is insufficient, and if it is more than 300 parts by mass, the cross-linking ratio of the epoxy resin becomes small, which causes a problem of elution from the light-shielding film. be.

(dye)
As the dye contained in the light-shielding paint according to the present invention, at least one or more kinds of dyes can be used. The dye may be any material that absorbs visible light having a wavelength of 400 nm to 700 nm and can be dissolved in any solvent. One type of dye may be used, or several types of dyes such as black, red, yellow, and blue may be mixed.

The content of the dye is preferably 46 parts by mass or more and 115 parts by mass or less with respect to 100 parts by mass of the kumaron-indene resin. If the content of the dye is less than 46 parts by mass, the light-shielding performance becomes insufficient, and if it is more than 115 parts by mass, elution of the dye from the light-shielding film becomes a problem.

(Pigment)
Optical lenses generally have a high refractive index, and it is necessary to increase the refractive index of the light-shielding film in order to reduce the reflection at the interface between the light-shielding film and the optical glass. For this purpose, as described in Patent Document 1, particles having a high refractive index may be introduced as a pigment. For example, titania and zirconia can be mentioned.

In addition, black particles may be used as the pigment, and carbon black, titanium black, iron oxide, and copper-iron-manganese composite oxide can be used.

The average particle size of the number of pigments is preferably 5 nm or more and 200 nm or less. When the average particle size of the number of pigments is less than 5 nm, the stability of the light-shielding paint is lowered. Further, when the number average particle size of the pigment is larger than 200 nm, the inner surface reflection when the light-shielding film is formed becomes large.

これらは、単独で用いても構わないし、複数を混合して用いても良い。 (Amine-based curing agent)
The light-shielding paint according to the present invention contains an amine-based curing agent for curing the epoxy resin contained in the light-shielding paint. As the amine-based curing agent, linear aliphatic-based, polyamide-based, alicyclic, aromatic, other dicyandiamide, and adipic acid dihydrazide can be used. Further, since the amino group of the amine-based curing agent is active, the active amino group may be protected by the structure represented by the formula (2). For example, the structure represented by formula (2) is hydrolyzed in the presence of water to become an active amino group. Therefore, when the light-shielding paint is formed, the amount of amino groups is small, so that the reaction with the components in the light-shielding paint can be suppressed.

These may be used alone or in combination of two or more.

The content of the amine-based curing agent contained in the light-shielding coating material according to the present invention is preferably 80 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the epoxy resin. When the content of the amine-based curing agent is less than 80 parts by mass, the degree of curing of the light-shielding film is lowered, and the adhesion of the light-shielding film to the substrate is lowered. Further, when the content of the amine-based curing agent is more than 150 parts by mass, the optical characteristics are deteriorated.

(Organic solvent)
The light-shielding coating material according to the present invention preferably contains an organic solvent in order to adjust the viscosity. The organic solvent used in the light-shielding coating material of the present invention is not particularly limited as long as it satisfies the solubility of the epoxy resin, the colorant and the amine-based curing agent and the dispersibility of the pigment. Examples of the organic solvent include propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, methyl ethyl ketone, methyl isobutyl ketone, 1-butoxy-2-propanol, dipropylene glycol dimethyl ether, diethylene glycol dimethyl ether, 3-methoxybutyl acetate, 4 −methoxy-4-methyl-2-pentanone, xylene, toluene, benzyl alcohol, isopropyl alcohol, acetone, ethanol can be used. These organic solvents may be used alone or in admixture of a plurality of types.

(Curing catalyst)
The light-shielding coating material according to the present invention may contain a curing catalyst in order to increase the crosslink density of the epoxy resin when a light-shielding film is formed and improve the solvent resistance. As the curing catalyst used in the present invention, it is preferable to use a tertiary amine or an imidazole compound. As the tertiary amine, benzyldimethylamine, 2- (dimethylaminomethyl) phenol, 2,4,6-tris (diaminomethyl) phenol, and tri-2-ethylhexylate can be used. Examples of the imidazole compound include 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1-benzyl-2-methylimidazole and 1-cyanoethyl. -2-Methylimidazole, 2,4-diamino-6- [2-methylimidazolyl- (1)]-ethylS-triazine can be used.

The content of the curing catalyst contained in the light-shielding paint according to the present invention is preferably 7.5 parts by mass or more and 35 parts by mass or less in the light-shielding paint. If the content of the curing catalyst is less than 7.5 parts by mass, the solvent resistance of the produced light-shielding film may decrease. Further, when the content of the curing catalyst is larger than 35 parts by mass, the crosslink density of the formed light-shielding film may increase and the toughness of the film may decrease.

(Coupling agent)
The light-shielding paint according to the present invention preferably contains a coupling agent in order to improve the adhesion between the resin and the pigment when the light-shielding film is formed. As an example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 2- (3, 4 Epoxycyclohexyl) ethyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyl Diethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3- Aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane , 3-Ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, 3-isocyanuppropyltriethoxysilane However, it is not limited to them.

(Plasticizer)
In the light-shielding paint according to the present invention, it is preferable to add a plasticizer in order to improve the flexibility when a light-shielding film is formed and to make it hard to crack. Examples of the plasticizer used in the present invention include dioctyl phthalate, diisononyl phthalate, diisodecyl phthalate, dibutyl phthalate, dioctyl adipate, diisononyl adipate, trioctyl trimellitic acid, polyester, tricresyl phosphate, tributyl acetylcitrate, and sebacine. Acid esters, xylene resins, epoxidized soybean oils, epoxidized flaxseed oils, azelaic acid esters, maleic acid esters, and benzoic acid esters can be used.

(Additive)
The light-shielding coating material according to the present invention may contain additives as long as the original purpose is not impaired. As the additive, a viscosity modifier, a fungicide, and an antioxidant can be added.

[Shading film]
Next, the light-shielding film according to the present invention will be described.
The light-shielding film according to the present invention is produced by applying the above-mentioned light-shielding paint and then curing it. The light-shielding film has a composition obtained by removing an organic solvent from the composition of the above-mentioned light-shielding paint. That is, the light-shielding film according to the present invention contains at least an epoxy resin, a kumaron-indene resin, a dye, and an amine-based curing agent, and may have each material of the above-mentioned light-shielding paint in addition to these.
The film thickness of the light-shielding film is preferably 0.3 μm or more and 100 μm or less, and more preferably 0.5 μm or more and 50 μm or less.

[Optical element]
The optical element of the present invention is an optical element in which a light-shielding film is provided on a part of the outer peripheral portion of the base material, and the light-shielding film is the above-mentioned light-shielding film.

A lens or prism can be used as the glass substrate which is an optical element. The refractive index of the d-line of the glass substrate is preferably 1.60 or more and 2.00 or less, and more preferably 1.80 or more and 2.00 or less.

The optical element of the present invention can be used as an element constituting an optical device such as a lens, a prism, a reflecting mirror, and a diffraction grating. For example, it is an optical element used for any of a camera, binoculars, a microscope, and a semiconductor exposure apparatus, and can be used as an optical element in which a light-shielding film is formed outside the optically effective surface.

[Manufacturing method of optical element]
The method for manufacturing an optical element of the present invention is a method for manufacturing an optical element in which a light-shielding film is provided on a part of the outer peripheral portion of the base material, and is a step of applying a light-shielding paint to the surface of the outer peripheral portion of the base material and coating. It has a step of curing the light-shielding paint. The above-mentioned light-shielding paint is used as the light-shielding paint used in the method for manufacturing an optical element of the present invention. In the method for manufacturing an optical element of the present invention, the materials and conditions of the above optical element can be used. Each process will be described below.

(Adjustment of light-shielding paint)
The light-shielding paint used in the method for manufacturing an optical element of the present invention is preferably prepared by mixing and dispersing the above-mentioned light-shielding paint material. As a mixing / dispersing method, a ball mill, a bead mill, a collision dispersion device, a planetary rotary stirring device, a homogenizer, and a stirrer can be used.

When a pigment is used, it is preferably nano-dispersed. As a specific method of nano-dispersion, there is a method of nano-dispersion with a bead mill or a collision dispersion device. Further, it may be synthesized by a sol-gel method and nano-dispersed during the synthesis, or a commercially available product which has been nano-dispersed in advance may be used.

(Process of applying light-shielding paint)
In the step of applying the light-shielding paint, the above-mentioned light-shielding paint of the present invention is applied to a part of the surface of the glass base material.

As a method of applying the light-shielding paint, a dipping method, a spin coating method, a slit coating method, an electrostatic coating method, a brush, a sponge, a bar coater, or the like is used according to the desired coating shape. Various coating methods can be selected.

(Process to cure light-shielding paint)
In the step of curing the light-shielding paint, the applied light-shielding paint is cured. In order to cure the light-shielding paint, the applied light-shielding paint may be dried or fired. In order to accelerate the curing reaction between the epoxy resin used in the present invention and the curing agent, it is desirable to perform the following drying. When it is dried, it is preferably dried at a temperature of 20 ° C. or higher and 100 ° C. or lower, more preferably at a temperature of 40 ° C. or higher and 80 ° C. or lower, and further preferably at a temperature of 40 ° C. or higher and 60 ° C. or lower. The drying time is preferably 10 minutes or more and 24 hours or less, more preferably 30 minutes or more and 24 hours or less, and further preferably 1 hour or more and 24 hours or less. In the case of firing, the temperature is preferably 40 ° C. or higher and 300 ° C. or lower, more preferably 40 ° C. or higher and 250 ° C. or lower, and further preferably 40 ° C. or higher and 200 ° C. or lower. The firing time is preferably 10 minutes or more and 10 hours or less, and more preferably 10 minutes or more and 6 hours or less.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples of the present invention.
In the examples and comparative examples, the following measurement methods and evaluation methods were used.
The "part" shown below means a "part by mass".

<Evaluation of optical characteristics>
As shown in FIG. 4, the inner surface reflectance was measured using a spectrophotometer (U-4000; Hitachi High-Tech). A triangular prism was used as the measurement sample. Reference numeral 14 indicates a prism. The triangular prism 14 has a length of 30 mm and a thickness of 10 mm on one side sandwiching a right angle, and the material is S-LaH53 (nd = 1.8; manufactured by O'Hara).

FIG. 4 is a schematic view showing a measurement method in which the incident angle b with respect to the triangular prism 14 is 90 °. First, a measurement method using a spectrophotometer will be described with reference to FIG. The light emitted from the spectrophotometer is incident on the triangular prism 14 at an incident angle b = 90 °. At this time, the refraction of light occurs due to the difference between the refractive index of air and the refractive index (n) of the triangular prism 14. The angle of incidence after refraction is c = 68.13 °. The angle e after refraction with respect to the incident angle d was calculated by the following formula (3). Further, the incident angle c was calculated from e after refraction.
n = sin d / sin e equation (3)

Subsequently, the light refracted by the triangular prism 14 hits the bottom surface of the triangular prism 14, is reflected, and goes out of the triangular prism 14. The intensity of this reflected light was detected by a detector in the visible light region having a wavelength of 400 nm to 700 nm. The background is a sample in which nothing is applied to the bottom surface of the triangular prism 14 having the bottom surface, the incident surface, and the reflecting surface, and the three surfaces of the bottom surface, the incident surface, and the reflecting surface are the bottom surface of the triangular prism 14 having a mirror surface. The inner surface reflectance when the light-shielding film 1 was formed was measured. As for the inner surface reflectance, the inner surface reflection of visible light having a wavelength of 400 nm to 700 nm was measured at 1 nm intervals, and the average value of the results was described.

<Viscosity evaluation of light-shielding paint at a temperature of 20 ° C>
The viscosity of the light-shielding coating material at a temperature of 20 ° C. was evaluated using a sound fork vibration viscous meter (SV-1H [product name] (manufactured by A & D Co., Ltd.)) at a constant temperature.

<Brightness evaluation of the paint moving part of the light-shielding paint>
In the application evaluation of the dye concentration for the optical element, a light-shielding paint was applied to flat glass (MICRO SLIDGLASS S1126 (manufactured by Matsunami Glass Ind.)) To cause the paint to move during drying.

Specifically, two 10 mm × 100 mm × 0.065 mm Kapton tapes are laminated on both ends of a 30 mm × 100 mm × 1 mm flat glass, and a step (0.130 mm) between the flat glass and the Kapton tape is attached. A sample was prepared.

A light-shielding paint for an optical element was uniformly applied to a coated portion (10 mm × 100 mm × 0.196 mm) of the obtained flat plate sample with a slide star, and the brightness of the coating film at the coated end after 1 hour of drying was evaluated.

The evaluation of the brightness value was made by placing the sample coated on the flat glass on white paper so that the coated surface was on the upper surface, photographing the upper surface of the coated surface, and then performing image processing. From the obtained image, the coated end portion was extracted, and the brightness value was binarized with 256 gradations, and then the average value was calculated and used as the brightness value. It was confirmed that there is a linear correlation between the obtained 256-gradation brightness and the result of internal reflection. The same processing was performed using the luminance value in Comparative Example 1 as a reference value, and the luminance values of each sample were compared.
The effect was evaluated according to the following criteria.
A: The effect of reducing the luminance value is reduced by 10% or more as compared with the reference value, which is good.
B: The effect of reducing the luminance value is less than 10% as compared with the reference value, which is insufficient.

<Appearance evaluation of light-shielding film>
The appearance of the light-shielding film for the optical element was evaluated by forming a flat glass of S-LaH53 (nd = 1.8; manufactured by OHARA Corporation) with a thickness of 10 μm as a material for evaluation and evaluating it according to the following criteria.
A: There is no visual cracking of the light-shielding film or peeling of the light-shielding film, and the color is uniform.
B: Corresponds to any one of visual light-shielding film cracking, light-shielding film peeling, and non-uniform color.

(Example 1)
<Preparation of light-shielding paint>
A light-shielding paint was prepared by the following method.
First, 100 parts of epoxy resin (jER828 [product name] (manufactured by Mitsubishi Chemical Co., Ltd.)), 174 parts of Kumaron-Inden resin (L-20 [product name] (manufactured by Nikko Chemical Co., Ltd.)), dye (1) VALIFAST-BLACK3810 [Product name] (manufactured by Orient Chemical Co., Ltd.) 21 parts, dye (2) VALUESTAT-RED3320 [Product name] (manufactured by Orient Chemical Co., Ltd.) 43 parts, dye (3) VALUESTAT-YELLOW3108 [Product name] (manufactured by Orient Chemical Co., Ltd.) 24 parts, dye (4) VALIFAST-BLUE2620 [product name] (manufactured by Orient Chemical Co., Ltd.) 43 parts, titania dispersion (ND139 [product name] (manufactured by Teika, titania concentration 25% by mass PGME dispersion)) 580 parts, Coupling agent (KBM403 [product name] (Shinetsu Silicone)) 135 parts, organic solvent propylene glycol monomethyl ether (PGME) (manufactured by Kishida Chemical Co., Ltd.) 300 parts, hydrophobic silica (1) (Aerodil R972 [product name] (Japan) Aerodil)) 45 parts, hydrophilic silica (2) (Aerodil 200 [product name] (Nippon Aerodil)) 18 parts, antifungal agent Syntoll (M-100 [product name] (manufactured by Sumika Enviroscience)) 7 The light-shielding coating precursor adjusted in the proportion of parts was put into a stirring container, the stirring container was set on a roll coater, and the mixture was stirred at 66 rpm for 10 hours. The total amount of the solvent is the sum of 75% by mass of PGME345 and PGME300 added as an organic solvent in the titania dispersion.
A curing agent (EH-6019 [product name] (manufactured by ADEKA Corporation)) was mixed with 100 parts of the precursor epoxy resin at a ratio of 110 parts to obtain a light-shielding paint.

Next, the obtained light-shielding paint was applied to a flat glass whose evaluation material was flat glass (MICRO SLIDGLASS S1126 (manufactured by Matsunami Glass Ind.)) To a thickness of 130 μm, and dried at room temperature for 60 minutes. After the light-shielding paint was dried, it was cured in a constant temperature furnace at a temperature of 140 ° C. for 2 hours to obtain a light-shielding film of Example 1. The obtained optical element brightness evaluation was performed under the above conditions.
Next, the obtained light-shielding paint was applied to a flat glass having a material for evaluation of S-LaH53 (nd = 1.8; manufactured by OHARA Corporation) with a film thickness of 10 μm, and dried at room temperature for 60 minutes. After the light-shielding paint was dried, it was cured in a constant temperature furnace at a temperature of 140 ° C. for 2 hours to obtain a light-shielding film of Example 1. The appearance of the obtained light-shielding film was evaluated under the above conditions.

Table 1 shows the main components of the obtained light-shielding film, the obtained optical element brightness evaluation result, and the appearance evaluation result of the film.

(Examples 2 to 5)
A light-shielding paint, a light-shielding film, and an optical element were prepared and evaluated in the same manner as in Example 1 except that the epoxy resin, the curing agent, the kumaron-indene resin, and the dye were used as the materials and conditions shown in Table 1. Table 1 shows the brightness value evaluation results and the appearance evaluation results of the obtained optical elements.

(Examples 6 to 12)
In Examples 6 to 12, a light-shielding paint, a light-shielding film, and an optical element were prepared and evaluated in the same manner as in Example 1 except that the type of kumaron-indene resin was changed. Table 1 shows the appearance, the brightness value, and the coating evaluation result of the obtained optical element.
In Example 6, kumaron-indene resin (V-120 [product name] (manufactured by Nikko Kagaku Co., Ltd.)), and in Example 7, kumaron-inden resin (A-053 [product name] (manufactured by Nikko Kagaku Co., Ltd.)). ), Kumaron-inden resin (G-90 [product name] (manufactured by Nikko Kagaku Co., Ltd.)) in Example 8, and Kumaron-inden resin (V-120S [product name] (Nikko Kagaku Co., Ltd.) in Example 9). )), Kumaron-inden resin (L-5 [product name] (manufactured by Nikko Kagaku Co., Ltd.)) in Example 10, and Kumaron-inden resin (PS-65 [product name] (Nikko)) in Example 11. In Example 12, Kumaron-inden resin (L-80 [product name] (manufactured by Nikko Kagaku Co., Ltd.)) was used.

(Example 13)
A light-shielding paint, a light-shielding film, and an optical element were produced in the same manner as in Example 1 except that the type of the curing agent was changed to 110 parts of the curing agent (jER Cure (R) H30 [Product Name] (manufactured by Mitsubishi Chemical Corporation)). And evaluated.

(Comparative Example 1)
Example 1 except that the xylene resin (Nicanol Y-50, [product name] (manufactured by Fudo Co., Ltd.)) was used instead of the kumaron-inden resin, and the epoxy resin and the curing agent were used as the materials and conditions shown in Table 1. Similarly, a light-shielding paint, a light-shielding film, and an optical element were prepared and evaluated. Table 1 shows the internal reflection and coating evaluation results of the obtained optical element.

(Comparative Examples 2 to 5)
A light-shielding paint, a light-shielding film, and an optical element were prepared and evaluated in the same manner as in Example 1 except that the kumaron-indene resin was used as the material and conditions shown in Table 1. Table 1 shows the internal reflection and coating evaluation results of the obtained optical element.

<Evaluation results>
In Examples 1 to 13, the effect of reducing the luminance value was reduced by 10% or more as compared with the reference value, which was good. In addition, the appearance of the coating film was also good with no peeling or cracking.

On the other hand, in Comparative Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 5, the effect of reducing the luminance value was less than 10% as compared with the reference value, which was insufficient. In Comparative Example 3, cracks occurred. In Comparative Example 4, the dye was leached out when the solvent was wiped.

The optical element of the present invention can be used in optical devices such as cameras, binoculars, microscopes, and semiconductor exposure devices.

1 Shading film 2 Lens 3 Incident light 4 Transmitted light 5 Incident light 6 Reflected light 7 Interface 8 Interface 9 Reflected light 10 Transmitted light 11 Reflected light 12 Ridge line 13 Phenomenon of light-shielding paint moving 14 Triangular prism

Claims (9)

An optical element in which a light-shielding film is provided on a part of the outer peripheral portion of the base material.
The light-shielding film is an optical element having an epoxy resin, a resin having at least kumaron or indene, and a dye. The optical element according to claim 1, wherein the content of the resin having kumaron or indene is 100 parts by mass or more and 300 parts by mass or less with respect to 100 parts by mass of the epoxy resin. The optical element according to claim 1 or 2, wherein the content of the dye is 46 parts by mass or more and 115 parts by mass or less with respect to 100 parts by mass of the resin having kumaron or indene. The optical element according to any one of claims 1 to 3, wherein the base material is a lens or a prism. The optical element according to any one of claims 1 to 4, wherein the light-shielding film has a film thickness of 0.3 μm or more and 100 μm or less. The optical element according to any one of claims 1 to 5, wherein the optical element is a lens or a prism. A method for manufacturing an optical element in which a light-shielding film is provided on a part of the outer peripheral portion of a base material.
A step of applying a light-shielding paint to the surface of the outer peripheral portion of the base material, and
It has a step of curing the applied light-shielding paint to produce a light-shielding film.
A method for producing an optical element, wherein the light-shielding coating material contains an epoxy resin, a resin having at least kumaron or indene, a dye, and an amine-based curing agent. The method for manufacturing an optical element according to claim 7, wherein the content of the resin having kumaron or indene is 100 parts by mass or more and 300 parts by mass or less with respect to 100 parts by mass of the epoxy resin. The method for producing an optical element according to claim 7 or 8, wherein the content of the dye is 46 parts by mass or more and 115 parts by mass or less with respect to 100 parts by mass of a resin having kumaron or indene.

Images