TWI766845B - Optical element for an ultraviolet illuminating apparatus, optical unit for an ultraviolet illuminating apparatus and ultraviolet illuminating apparatus - Google Patents

Abstract

An ultraviolet absorbing paint able to form a coating film that can suppress the generation of the stray light with a thin film configuration and exhibit an excellent durability is provided. The ultraviolet absorbing paint comprises the precursor of the oxide of at least one transition metal selected from the group consisting of: Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn and Ce. The precursor of the oxide of the at least one transition metal is preferably the metallic salt, the metallic acid salt, or the organic metallic compound of at least one transition metal selected from the group consisting of: Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn and Ce.

Description

Optical elements for UV irradiation devices, for UV irradiation The optical unit of the radiation device and the ultraviolet light radiation device

The present invention relates to an ultraviolet absorbing paint, an ultraviolet absorbing film, a light absorbing film, an optical element, an optical unit and a light irradiation device.

For optical elements such as lenses and lenses generally used in optical instruments such as cameras and microscopes, the incident light to the optical element enters from the ridgeline of the optical element, the edge of the lens (side surface of the lens) and other peripheral parts, or enters The light is reflected on the inner surface of the edge, etc., so stray light (stray light) is generated, and the stray light is mixed into the original illumination light, which will cause reflection spots and ghosts in the imaged image, thereby reducing the optical quality. Optical properties of the instrument.

In order to prevent the above-mentioned stray light, it is known to apply a black paint having an internal reflection preventing function to peripheral portions such as ridges and edges of an optical element to form a coating film of the black paint.

As the above-mentioned black paint having an internal reflection preventing function, for example, a paint containing a metal oxide such as iron oxide, carbon black, a binder resin, a phthalocyanine compound, and a dispersant and a solvent containing a polymer-based dispersant have been proposed (refer to Patent Literature 1 (Japanese Patent Laid-Open No. 2014-21231 )).

prior art literature

Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2014-21231

The black paint described in Patent Document 1 is a paint in which metal oxide particles and carbon black particles are used as light absorbing components, and is obtained by dispersing the above-mentioned particles in a vehicle (binder resin and solvent), but has the following problems : Not only does the dispersion treatment of the above-mentioned particles take time, and it is difficult to prepare easily, but after the preparation, each of the above-mentioned particles aggregates and settles to easily become non-uniform, and the pot life (usable time) is short.

In addition, the existing antireflection coatings such as the black paint described in Patent Document 1 target visible light, infrared light, etc., and are basically used in an environment where the light intensity is not so strong. Since the ultraviolet light with high light intensity tends to be absorbed, the stray light to be absorbed also becomes light with high light energy and light intensity.

When the black paint described in Patent Document 1 is used to form a coating film on the surface of an optical element, although the solvent evaporates and disappears, organic components such as binder resin and dispersant remain. Therefore, when ultraviolet light is incident on the optical element This organic component is degraded, and since carbon black is also a carbon element substance, it is easy to degrade when high-intensity ultraviolet light is incident.

The light absorbed by the coating film is converted into heat, and when the intensity of the incident light is high, the deterioration of the binder resin, dispersing agent, etc. is accelerated, and the coating film is not only degraded. Cracks are generated and peeled off, and carbon black is also deteriorated and easily discolored.

For example, as an ultraviolet LED (UV-LED) as a light source for curing ultraviolet-curable resins and ultraviolet-curable inks, an LED that emits ultraviolet light with a wavelength of 365 nm and 1 W by supplying a power of 3 W to a 1 mm square LED wafer is used. In this case, the irradiation light amount is 1 W/mm ² , which corresponds to 30,000 to 50,000 times the amount of ultraviolet light contained in sunlight. Therefore, as a black paint having an internal reflection preventing function used in such a light source device, it is required to have resistance to strong ultraviolet rays.

In addition, 2W of the 3W power supplied to the above-mentioned ultraviolet LEDs is converted into heat energy, so that the LED chip itself reaches a high temperature. Therefore, as a black paint with an internal reflection prevention function, in addition to ultraviolet resistance, heat (temperature) tolerance.

In order to solve the above-mentioned technical problem, the inventors have conducted studies, and have come up with the idea of forming an ultraviolet-absorbing film that does not contain an organic component as the above-mentioned coating film.

As a material for forming such an ultraviolet absorbing film, colored low-melting glass or low-melting glass containing an inorganic pigment can be considered, but when these materials are used to form a coating film, the thickness of the coating film is, for example, several hundreds of micrometers ( μm), in contrast, the processing tolerance of optical components such as lenses is about ±0.05~0.10mm (50~100μm). When the coating film becomes thicker, it cannot be incorporated into a given position, making it difficult to correct.

In addition, for low-melting glass, if the difference between the thermal expansion coefficient and the thermal expansion coefficient of optical elements such as lenses and lenses is not controlled within a certain range, cracks may occur in the optical element or the low-melting glass layer (coating film), or low melting point glass Since peeling occurs, it is difficult to continue to use the optical instrument having the optical element.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide an ultraviolet absorbing paint capable of forming a coating film that can highly suppress the generation of stray light in a thin film state and exhibit excellent durability, as well as an ultraviolet absorbing film and a light absorbing film , optical elements, optical units and light irradiation devices.

In order to achieve the above objects, the inventors have conducted intensive research and found that the use of oxide precursors containing one or more transition metals selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn and Ce The ultraviolet-absorbing paint can solve the above-mentioned technical problems, and the present invention has been completed based on this knowledge.

That is, the present invention provides the following technical solutions:

(1) An ultraviolet absorbing paint containing an oxide precursor of one or more transition metals selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn and Ce.

(2) The ultraviolet absorbing paint described in (1) above, wherein the oxide precursor of the transition metal is one selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn and Ce Metal salts, metal salts or organometallic compounds of the above transition metals.

(3) The ultraviolet absorbing paint according to (1) or (2) above, which contains 0.5 to 20.0 mass % of the transition metal oxide precursor in terms of transition metal oxide.

(4) The ultraviolet absorbing paint described in (1) to (3) above, further comprising one or more selected from the group consisting of a silicon oxide precursor and an aluminum oxide precursor.

(5) The ultraviolet absorbing paint according to (1) to (4) above, which further contains a colorant.

(6) An ultraviolet absorbing film containing oxides of one or more transition metals selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Ce.

(7) The ultraviolet absorbing film according to (6) above, which further contains silicon oxide or aluminum oxide.

(8) The ultraviolet absorbing film according to (6) or (7) above, which contains 20 to 100% by mass of the oxide of the transition metal.

(9) The ultraviolet absorbing film according to any one of (6) to (8) above, which has a film thickness of 50 μm or less.

(10) A light absorbing film comprising a laminate, which is a laminate of the ultraviolet absorbing film described in any one of (6) to (9) above and an absorbing film that absorbs at least visible light or infrared rays thing.

(11) An optical element having the ultraviolet absorbing film according to any one of the above (6) to (9) or the light absorbing film according to the above (10) on the surface.

(12) An optical unit including the optical element described in (11) above.

(13) A light irradiation device including the optical unit described in (12) above.

ADVANTAGE OF THE INVENTION According to the present invention, it is possible to provide an ultraviolet absorbing paint capable of forming a coating film that can highly suppress the generation of stray light in a thin film state and exhibit excellent durability, and can also provide an ultraviolet absorbing film, a light absorbing film, an optical element, and an optical unit and light irradiation device.

1: Wafer

1a: Resist film

A: UV absorbing film

B: substrate

C: UV absorbing film

D: LED chip

d: sag width

E: edge part

G: Quartz glass substrate

I: UV light

L: lens

L1: first lens

L2: Second lens

L3: Third lens

LR: light receiving part

M: mirror surface

MB:Mirror Case

P: Optically polished surface

R: Receiver

S: Stray Light

T: lens barrel

U: Optical unit

W: frosted surface

Fig. 1 is a schematic diagram showing an example of an embodiment of a conventional optical element (Fig. 1(a)) and a schematic diagram of an example of an embodiment of the optical element of the present invention (Fig. 1(b)).

FIG. 2 is a schematic diagram showing an example of an embodiment of the optical element of the present invention.

FIG. 3 is a schematic diagram showing an example of an embodiment of the optical element of the present invention.

FIG. 4 is a schematic diagram showing an example of an embodiment of the optical element of the present invention.

FIG. 5 is a schematic diagram showing an example of an embodiment of the optical unit of the present invention.

FIG. 6 is a schematic diagram showing an example of an embodiment of the light irradiation device of the present invention.

FIG. 7 is a graph showing the transmittance curve of the substrate with the _{FexOy -} based ultraviolet absorbing film obtained in Example 1. FIG.

FIG. 8 is a schematic diagram for explaining the evaluation method of the ultraviolet absorption effect.

FIG. 9 is a schematic diagram for explaining a method for evaluating the durability of an ultraviolet absorbing film.

FIG. 10 is a graph showing a transmittance curve of a substrate with a chromium oxide (Cr _x O _y )-SiO ₂ ultraviolet absorbing film obtained in Example 2. FIG.

11 is a graph showing a transmittance curve of the substrate with a manganese oxide (Mn _x O _y )-based ultraviolet absorbing film obtained in Example 3. FIG.

FIG. 12 is a graph showing the transmittance curve of the substrate with the manganese oxide (Mn _x O _y )-SiO ₂ type ultraviolet absorbing film obtained in Example 4. FIG.

FIG. 13 is a graph showing the transmittance curves of the glass substrates after each of the coating liquids for absorbing film formation obtained in Example 5 and Example 6 were applied and dried.

FIG. 14 is a diagram showing the transmittance curve of the glass substrate after the coating liquid for forming an absorbing film obtained in Example 5 and Example 6 was applied, dried, and then heat-treated.

FIG. 15 is a graph showing the transmittance curves of the coating liquids for forming an absorbing film themselves obtained in Examples 5 and 6. FIG.

FIG. 16 is a schematic diagram for explaining the shape of the edge portion of the silicon wafer obtained in Example 7 and Comparative Example 2. FIG.

First, the ultraviolet absorbing paint of the present invention will be described.

The ultraviolet absorbing paint of the present invention contains one or more transition metal oxide precursors selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn and Ce.

Hereinafter, in the present disclosure, ultraviolet rays refer to light with wavelengths ranging from 250 to 420 nm. In addition, in the present disclosure, the oxide precursor of a transition metal refers to a substance capable of forming an oxide of the transition metal by heating.

The ultraviolet absorbing paint of the present invention contains one or more transition metal oxide precursors selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn and Ce As an oxide precursor of a transition metal, the transition metal is preferably one or more selected from Ti, Cr, Mn, Fe, Co, Ni, Cu and Zn, more preferably Ti, Cr, Mn, One or more of Fe, Cu, and Zn.

The transition metal oxide precursor is preferably a transition metal metal salt, metal salt or organometallic compound.

The metal salt of the transition metal is not particularly limited as long as it can form an oxide of the transition metal under heating and can be dissolved in the ultraviolet absorbing paint, and examples thereof include nitrates, sulfates, acetates, chlorine One or more metal salts of compounds, phosphates, carbonates, hydroxides, etc.

The metal salt of the transition metal is not particularly limited as long as it can form an oxide of the transition metal under heating and can be dissolved in the ultraviolet absorbing paint, and examples thereof include vanadates, chromates, One or more of chromate, manganate, permanganate, ferrite, ferrite, cobaltate, nickelate, cuprate, zincate, ceria, etc.

The organometallic compound of the transition metal is not particularly limited as long as it can form an oxide of the transition metal under heating and can be dissolved in the ultraviolet absorbing paint, and examples thereof include metal alkoxides and derivatives of metal alkoxides (such as , an organometallic compound obtained by substituting a part or all of the alkoxy groups of metal alkoxides with ligands such as acetylacetone and ethyl acetate), stearic acid soap, lauric acid soap, ricinoleic acid soap, caprylic acid One or more of soaps, naphthenic acid soaps, montanic acid soaps, behenic acid soaps, sebacic acid soaps, myristic acid soaps, palmitic acid soaps, 12-hydroxystearic acid soaps, and the like.

Oxides of one or more transition metals selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Ce exhibit strong absorptivity for light in the ultraviolet region.

The ultraviolet absorbing coating material of the present invention can form an ultraviolet absorbing film containing a transition metal oxide on the surface of a coating object such as an optical element by applying it to an object to be coated such as an optical element and heating it. In a device that outputs high-intensity ultraviolet light with high light energy, even when an ultraviolet-absorbing coating is used to absorb ultraviolet light, the generation of stray light can be highly suppressed in a thin film state. In addition, the ultraviolet-absorbing coating contains organic components such as solvents. Even in the case of the above-mentioned heat treatment, the organic components can be removed and a uniform transition metal oxide film can be formed. Therefore, the obtained ultraviolet absorbing film can suppress the deterioration of the organic components. Discoloration, peeling, disappearance, etc., can exhibit excellent durability well.

The ultraviolet absorbing paint of the present invention may further contain at least one selected from the group consisting of silicon oxide precursors and aluminum oxide precursors.

In the present disclosure, silicon oxide precursors refer to substances capable of forming silicon oxides by heating, such as: tetraethoxysilane, tetramethoxysilane, methyltriethoxysilane, methyltrimethylsilane Oxysilane, dimethyldiethoxysilane, dimethyldimethoxysilane, oligomers formed from one or more of them, and polysilazane.

In the present disclosure, the aluminum oxide precursor refers to a substance that can form aluminum oxide by heating, for example, aluminum alkoxides selected from aluminum sec-butoxide, aluminum isobutoxide, etc., acetylacetone, acetylacetic acid, etc. Aluminum chelate compounds obtained by modifying part or all of the alkoxy groups of the above-mentioned aluminum alkoxides with chelating agents such as ethyl esters, aluminum soaps such as aluminum stearate, aluminum octoate, and aluminum naphthenate, aluminum nitrate nonahydrate, One or more of aluminum salts such as aluminum chloride and polyaluminum chloride.

The ultraviolet absorbing paint of the present invention further contains at least one selected from the group consisting of silicon oxide precursors and aluminum oxide precursors, so that transition metal oxides and silicon oxides or aluminum oxides can be easily formed during the formation of an ultraviolet absorbing film. The composite film can improve the adhesion of the UV-absorbing film obtained by coating the UV-absorbing coating to the optical element, and make the UV-absorbing film difficult to peel off.

The ultraviolet absorbing paint of the present invention may further contain a colorant.

When the ultraviolet absorbing paint of the present invention contains a colorant, the colorant is a colorant that is stably dissolved or dispersed in the paint without gelation or precipitation of the absorbing film material, and has light-absorbing ability to visible light. Preferably, a colorant that can disappear by decomposition, volatilization, etc., at a temperature at which the oxide precursor of a transition metal contained in the ultraviolet absorbing paint forms a metal oxide, or a colorant that can form an inorganic oxide.

As said coloring agent, dyes, such as a dye and a pigment, are mentioned, and a dye is preferable. Dye is preferably used as the colorant from the viewpoints of being easily dissolved in the coating material and hard to agglomerate.

In the case where the above-mentioned colorant is a dye, the dye is not particularly limited as long as it can be dissolved in the ultraviolet absorbing paint to make the coating film visible, and examples thereof include methylene blue, triphenylmethane dyes (for example, malachite green ), ice dyes, azo dyes, acridine, aniline dyes (eg, nigrosine), indanthrene, eosin, Congo red, indoline, phenazine derivative pigments (eg, neutral red) , phenolphthalein, magenta, luciferin, Para red, aniline violet (mauve), caramel color, gardenia color, anthocyanin color, annatto color, capsaicin, safflower color, Red yeast pigment, flavonoid pigment, cochineal pigment, amaranth (Red No. 2), Erythrosine (Red No. 3), Allura Red AC (Allura Red AC) (Red No. 40), New Coccine (Red No. 102), Phloxine (Red No. 104), Rose Bengal (Red No. 105), Acid Red (Red No. 106), Tartrazine (Yellow No. 4), Sunset Yellow FCF One or more of (Sunset Yellow FCF) (Yellow No. 5), Fast Green FCF (Green No. 3), Brilliant Blue FCF (Blue No. 1) and Sulfonated Indigo (Blue No. 2).

In the case where the colorant is a pigment, the pigment is not particularly limited as long as it is a pigment that does not easily aggregate, and examples thereof include iron oxide red, ultramarine blue, Prussian blue, carbon black, and isoindoline. ketones, isoindolines, carbamidolines, anthraquinones, anthrones, xanthenes, diketopyrrolopyrroles, perylenes, perinones, quinacridones, indigoids, dioxins One or more of oxazine and phthalocyanine.

The UV-absorbing film obtained from the UV-absorbing paint of the present invention can highly suppress the generation of stray light even in a thin film state. The thickness of the lens is also reduced, and it is difficult to identify whether it is coated on a given part, whether the required amount is coated, and whether it is attached to the non-coated surface such as the entrance surface and the exit surface of the lens. When the UV-absorbing paint is transparent, it becomes more difficult to identify the coating film. Although the UV-absorbing paint may be pre-colored with the transition metal oxide precursor used, etc., when the degree of coloring is low and the above-mentioned When the thickness of the coating film is reduced, it is also difficult to recognize the coating film. Before drying and heat-treating the above-mentioned coating film to form an ultraviolet absorbing film, the coated film may be mistakenly wiped off, and when the heat-treatment is directly performed, it is difficult to sinter on the surface of the optical element. remove, The yield of the product is reduced.

When the ultraviolet-absorbing paint of the present invention further contains a colorant, the ultraviolet-absorbing paint can easily recognize the presence or absence of a coating film during application, and can easily improve the production efficiency of optical elements and the yield of products.

In the case where the ultraviolet absorbing paint of the present invention contains a colorant, the content ratio of the colorant is calculated as an increase ratio (that is, the amount of the colorant added/the total amount of the ultraviolet absorbing paint after adding the colorant) to the ultraviolet absorbing paint. Preferably it is 0.005-20 mass %, More preferably, it is 0.01-10 mass %, More preferably, it is 0.05-5 mass %.

The UV-absorbing paint of the present invention may further contain a binder component or a solvent.

When the ultraviolet absorbing paint of the present invention contains a binder component or a solvent, the binder component or solvent is preferably decomposed and volatilized at a temperature at which the oxide precursor of a transition metal contained in the ultraviolet absorbing paint forms a metal oxide. Adhesive components or solvents that disappear after waiting.

As said binder component, 1 or more types chosen from polyvinyl pyrrolidone, polyethylene glycol, polyvinyl alcohol, hydroxyethyl cellulose, hydroxypropyl cellulose, polyvinyl acetate, chitosan, etc. are mentioned.

By including a binder component in the ultraviolet absorbing paint of the present invention, the oxide precursor of the transition metal can be stably and uniformly applied to the base material, and the ultraviolet absorbing film can be easily formed.

The above-mentioned binder can be appropriately selected according to the type of the oxide precursor of the transition metal contained in the UV-absorbing paint. For example, in the UV-absorbing paint When the precursor containing manganese oxide is used as the oxide precursor of the transition metal, it is preferable to contain polyvinylpyrrolidone as a binder. By containing polyvinylpyrrolidone as a binder, the precursor of manganese oxide can be well dissolved in the ultraviolet absorbing paint. middle.

Moreover, as a solvent, the solvent which disappears by decomposition, volatilization, etc. at the temperature at which the oxide precursor of the transition metal contained in an ultraviolet-absorbing coating material forms a metal oxide is preferable.

Examples of the solvent include butanols such as methanol, ethanol, n-propanol, isopropanol, and n-butanol, 2-methoxyethanol, 2-ethoxyethanol, ethylene glycol, and diethylene glycol. , one or more of methyl acetate, ethyl acetate, propyl acetate, butyl acetate, propionic acid, butyric acid, etc.

In the ultraviolet absorbing paint of the present invention, the content ratio of the oxide precursor of the transition metal in terms of the oxide of each transition metal is preferably 0.1 to 20.0 mass %, more preferably 0.5 to 15.0 mass %, and still more preferably 1.0 ~10.0 mass %.

In the ultraviolet-absorbing coating material of the present invention, when the content ratio of the transition metal oxide precursor is within the above-mentioned range, the occurrence of cracks and peeling can be favorably suppressed when forming the ultraviolet-absorbing film.

Generally, when an inorganic oxide film is formed on a substrate using a precursor of a metal oxide, the surface side of the substrate of the generated inorganic oxide film is bonded to the substrate to easily suppress shrinkage. The outer surface side of the oxide film is free to shrink, and it is accompanied by a large volume shrinkage. Since the metal oxide film is less flexible than the organic film, the stress caused by the above volume shrinkage is affected. Under use, the oxide film will be prone to cracking and peeling.

When the content ratio of the transition metal oxide precursor is less than 0.1 mass %, the thickness of the obtained transition metal oxide film tends to be thin, and it is difficult to obtain the target absorption characteristics. When the ratio exceeds 20.0 mass %, the film thickness of the obtained transition metal oxide film becomes thick, the above-mentioned stress is likely to increase, and the above-mentioned cracking and peeling are likely to occur.

It should be noted that, in the present disclosure, for the oxides of transition metals when calculating the content ratio of transition metals, when the transition metal is Ti, it refers to TiO ₂ , and when the transition metal is V, it refers to V ₂ O ₅ , Cr ₂ O ₃ when the transition metal is Cr, Mn ₂ O ₃ when the transition metal is Mn, Fe ₂ O ₃ when the transition metal is Fe, and CoO when the transition metal is Co, When the transition metal is Ni, it means NiO, when the transition metal is Cu, it means CuO, when the transition metal is Zn, it means ZnO, and when the transition metal is Ce, it means CeO ₂ .

In the ultraviolet-absorbing coating material of the present invention, when the content ratio of the transition metal falls within the above-mentioned range, not only the transition metal can be favorably dissolved, but also an ultraviolet-absorbing film having a desired thickness can be easily formed.

When the ultraviolet absorbing paint of the present invention further contains at least one selected from the group consisting of silicon oxide precursors and aluminum oxide precursors, the transition metal oxides converted to the above oxides are converted to these oxides. The total content of the precursors is preferably 1.0 to 30.0 mass %, more preferably 2.0 to 25.0 mass %, and further preferably 3.0 to 20.0 mass %.

In the ultraviolet absorbing paint of the present invention, the total content ratio of one or more selected from the silicon oxide precursor and the aluminum oxide precursor is Within the above range, the adhesiveness of the obtained ultraviolet absorbing film to the base material can be improved, and the occurrence of the above-mentioned cracks and peeling can be easily suppressed.

It should be noted that, in the present disclosure, the oxide of the silicon oxide precursor when the content ratio is calculated refers to SiO ₂ , and the oxide of the aluminum oxide precursor when the content ratio is calculated refers to Al ₂ O ₃ .

For the ultraviolet absorbing coating of the present invention, for example, by mixing a transition metal oxide precursor and optionally a silicon oxide precursor and an aluminum oxide precursor in the presence of a suitable binder, solvent, etc. One or more dissolved in the desired amount can be easily prepared.

ADVANTAGE OF THE INVENTION According to this invention, the ultraviolet-absorbing coating material which can form the coating film which can suppress the generation|occurence|production of stray light in a thin film state highly, and can exhibit excellent durability can be provided.

Next, the ultraviolet absorbing film of the present invention will be described.

The ultraviolet absorbing film of the present invention is characterized by containing an oxide of one or more transition metals selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Ce.

The transition metal is preferably one or more selected from Ti, Cr, Mn, Fe, Co, Ni, Cu, and Zn, and more preferably one or more selected from Ti, Cr, Mn, Fe, Cu, and Zn.

Transition metals usually have multiple valence states, so transition metal oxides can also be in multiple forms. In the present disclosure, transition metal oxides not only refer to being composed of a specific transition metal oxide, but also include a mixture of multiple oxides. form of existence.

In addition, the ultraviolet absorbing film of the present invention may be an ultraviolet absorbing film in which two or more transition metal oxides coexist.

Oxides of one or more transition metals selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Ce exhibit strong absorptivity for light in the ultraviolet region.

Since the ultraviolet absorbing film of the present invention contains the oxide of the transition metal described above, in a device capable of outputting ultraviolet light with high light energy at high intensity, even when it is used for absorbing ultraviolet light, it can be highly suppressed in a thin film state. The generation of stray light, and even when irradiated with ultraviolet rays for a long time, the discoloration, peeling, disappearance, etc. of the coating film can be suppressed, and excellent durability can be exhibited well.

In addition, the ultraviolet absorbing film of the present invention may further contain at least one selected from the group consisting of silicon oxides and aluminum oxides in addition to the transition metal oxides.

By further containing one or more selected from silicon oxides and aluminum oxides in the ultraviolet absorbing film of the present invention, a composite film of transition metal oxides, silicon oxides, aluminum oxides, etc. can be formed, and the composite film can improve the The adhesion of the base material can easily suppress the occurrence of the above-mentioned cracks and peeling.

The ultraviolet absorbing film of the present invention preferably contains 20 to 100 mass % of the oxide of the transition metal, more preferably 30 to 100 mass %, and further preferably 35 to 100 mass %.

The film thickness of the ultraviolet absorbing film of the present invention is preferably 50 μm or less, more preferably 25 μm or less, still more preferably 10 μm or less, and still more preferably 5 μm or less.

Although the ultraviolet absorbing film of the present invention can sufficiently absorb ultraviolet light even if it is a thin film, in order to achieve the object of the present invention, the film thickness of the ultraviolet absorbing film is preferably 0.01 μm or more, more preferably 0.02 μm or more, and still more preferably 0.05 μm Above, more preferably 0.10 μm or more.

When the ultraviolet absorbing film of the present invention is provided on the surface of an optical element, in particular, since many optical elements for LEDs are very small in shape, the processing tolerance of the optical element is usually ±100 μm, and in severe cases, ±50 μm . Although the ultraviolet absorbing film is required to be a thin film in order to accurately center the optical elements, and when a plurality of various optical elements are arranged in a configuration, ultraviolet rays are also required to suppress the positional displacement of the individual optical elements The absorbing film is a thin film, however, the ultraviolet absorbing performance of the ultraviolet absorbing film is generally lowered when it is formed into a thin film.

The ultraviolet absorbing film of the present invention contains an oxide of a specific transition metal, and therefore, in a device capable of outputting ultraviolet light with high light energy at high intensity, even when it is used for absorbing ultraviolet light, the film can be used in the form of a thin film. The generation of stray light is highly suppressed.

It should be noted that, in the present disclosure, the film thickness of the ultraviolet absorbing film refers to the use of a micrometer (MDH-25M manufactured by Mitutoyo Corporation) to measure the total thickness of the base material and the ultraviolet absorbing film and the thickness of the base material, respectively. The value obtained from the difference between the two.

In the ultraviolet absorbing film of the present invention, the optical density (OD) of the ultraviolet absorbing film is preferably 1 or more, more preferably 2 or more, and still more preferably 3 or more.

By making the optical density (OD) within the above-mentioned range, it is possible to obtain a high-intensity In a device that outputs ultraviolet light with a large light energy, even when it is used for absorbing ultraviolet light, the generation of stray light can be highly suppressed in the form of a thin film.

It should be noted that, in the present disclosure, optical density (OD) refers to the use of an ultraviolet-visible-near-infrared spectrophotometer (U-4100 manufactured by Hitachi, Ltd.), when irradiating light with a wavelength or wavelength range that is an absorption target The value measured when irradiated with light.

It is desirable that the ultraviolet absorbing film of the present invention has no cracks (cracks) when observed with the naked eye.

By making the ultraviolet absorbing film of the present invention free from cracks (cracks), peeling of the ultraviolet absorbing film from an object to be formed such as an optical element can be easily suppressed, the formation of chips and the like can be easily suppressed, and desired stray light absorption can be easily obtained Effect.

The ultraviolet absorbing film of the present invention is preferably provided on the surface of a portion other than the original optical path among optical elements/optical elements such as lenses, lenses, and lens barrels. The surface of the part other than the entrance/exit surface, the inner surface of the lens barrel, etc.

By providing the ultraviolet absorbing film of the present invention on the surface of the portion other than the original optical path in this way, in a device capable of outputting ultraviolet light with a high intensity and high light energy, even when it is used for absorbing ultraviolet rays, it is possible to form a film in the form of a film. The generation of stray light is highly suppressed.

The ultraviolet absorbing film of the present invention can be preferably produced using the ultraviolet absorbing paint of the present invention.

Examples of the method for producing the ultraviolet absorbing film of the present invention include For example, a method of forming a film by a sol-gel method by applying the ultraviolet absorbing paint of the present invention to a substrate (a target for forming an absorbing film).

As a method for producing such an ultraviolet absorbing film, for example, a coating of a desired thickness is formed by applying the ultraviolet absorbing coating material of the present invention to an object to be film-formed using a brush, a sprayer, or by a dipping method or a spin coating method. A method of fabricating the film, and then appropriately performing drying treatment and heat treatment. The temperature at the time of the heat treatment is preferably 300 to 1000° C., and the treatment time at the time of the heat treatment is preferably 1 minute to 12 hours.

By the above-described method, a target metal oxide film (ultraviolet absorbing film) can be formed.

The ultraviolet absorbing film of the present invention can highly suppress the generation of stray light in a thin film form even when used for absorbing ultraviolet light in a device capable of outputting ultraviolet light with high light energy at high intensity.

Next, the light-absorbing film of the present invention will be described.

The light absorbing film of the present invention is characterized by comprising a laminate which is a laminate of the ultraviolet absorbing film of the present invention and an absorbing film that absorbs at least visible light or infrared light.

The details of the ultraviolet absorbing film of the present invention are as described above.

In the light absorbing film of the present invention, the absorbing film absorbing visible light or infrared light can be provided on the ultraviolet absorbing film of the present invention by applying a known coating agent capable of forming a visible light or infrared absorbing film.

Examples of the above-mentioned coating agent include anti-reflection coatings (manufactured by CANON CHEMICALS, model CS-37, etc.), near-infrared shielding One or more of cover materials (manufactured by Sumitomo Metal Mining Co., Ltd., model YMF-02A, etc.), etc.

The light absorbing film of the present invention may be provided so that the ultraviolet absorbing film is located on the light incident side, or may be provided so that the absorbing film absorbing visible light or infrared light is located on the light incident side.

The light absorbing film of the present invention, by having an absorbing film that absorbs at least any one of visible light or infrared light on the ultraviolet absorbing film that absorbs ultraviolet light of the present invention, can be applied even if it is applied to a light source that emits ultraviolet light and visible light including large light energy, Also in the case of a light-emitting body of infrared light, the generation of stray light can be highly suppressed.

Examples of light-emitting bodies that emit light including ultraviolet light, visible light, and infrared light with high luminous energy include lamps such as mercury xenon lamps, xenon lamps, and metal halide lamps, ultraviolet LEDs (UV-LEDs), white LEDs, and on-substrate lamps. Light-emitting elements such as LED units that incorporate multi-wavelength LEDs are mixed.

Next, the optical element of the present invention will be described.

The optical element of the present invention is characterized by having the ultraviolet absorbing film or the light absorbing film of the present invention on the surface thereof.

The details of the ultraviolet absorbing film or the light absorbing film of the present invention are as described above. In addition, in the optical element of the present invention, the details of the film-forming position and the film-forming method of the ultraviolet absorbing film are also as described above.

Examples of the optical element of the present invention include one or more items selected from what are generally called optical elements, optical elements, etc., such as lenses, lenses, lens barrels, mirrors, and the like.

Hereinafter, the optical element of the present invention will be described with reference to specific examples. Bright.

FIG. 1 is a schematic diagram showing a cross section of a conventional optical element (lenticular lens L) as an optical element (FIG. 1(a)) and a cross section of an optical element (lenticular lens L) of the present invention as an example of the optical element Schematic diagram (Fig. 1(b)), in general, for a lenticular lens, as shown in Fig. 1(a), part of the ultraviolet light I incident on the optical surface is incident from the edge (side) of the lens, However, as shown in Fig. 1(b), since the optical element of the present invention has an ultraviolet absorbing film A at the edge of the lenticular lens L, it can effectively absorb ultraviolet rays at the edge of the lens. light, the generation of stray light S (stray light S generated when the lenticular lens L does not have the ultraviolet absorbing film A is shown by the dotted line in FIG. 1(b) for convenience).

In Fig. 1, a biconvex lens is exemplified as the lens L, but for the lens L, any one of a biconcave lens, a plano-convex lens, and a plano-concave lens may be used instead of the biconvex lens. In this case, the ultraviolet absorbing film A is provided at the edge of each lens.

FIG. 2 is a schematic diagram showing a cross section of a meniscus lens, which is an example of the optical element of the present invention. Generally, in a meniscus lens, as shown in FIG. 2 , part of the ultraviolet light I incident on the optical surface is The edge (side) of the lens is incident or reflected on the inner wall surface of the lens edge, thereby generating stray light S. However, since the optical element of the present invention has the ultraviolet absorbing film A at the edge of the lens L, it can effectively By absorbing ultraviolet light, the generation of stray light can be suppressed (for convenience, the stray light S generated when the meniscus lens L does not have the ultraviolet absorbing film A is indicated by a broken line in FIG. 2).

In addition, in the meniscus lens shown in FIG. 2, in order to allow light to selectively enter the concave portion of the incident surface, a light shield is usually provided on the flat portion of the incident surface to block light. However, in the case where the shield is not provided Next, stray light S is similarly generated by light incident from the flat portion of the incident surface. Therefore, in the example shown in FIG. 2, the ultraviolet absorbing film A is also provided on the flat portion of the incident surface, and the flat portion on the incident surface side effectively absorbs ultraviolet light, which can also serve as the above-mentioned mask and suppress stray light at the same time. production.

FIG. 3 is a schematic diagram showing a cross section of a lens barrel, which is an example of the optical element of the present invention. Generally, in the lens barrel, as shown in FIG. 3, a part of the incident light I entering the lens barrel surface is The inner wall surface of the lens barrel is reflected to generate stray light S, but since the lens barrel shown in Fig. 3 has an ultraviolet absorbing film A on the inner wall surface of the lens barrel T, the inner wall surface can effectively absorb light and stray light can be suppressed (for convenience, the stray light S generated when the lens barrel T does not have the ultraviolet absorbing film A is represented by a broken line in Fig. 3).

Conventionally, the lens barrel has been processed with a black aluminum oxide film in which black dye is impregnated with cavities generated by an aluminum oxide film treatment on the inner wall surface. However, since the black dye is an organic substance, it cannot be used under short-wavelength light such as ultraviolet light. , When high-intensity light irradiates the lens barrel, the dye will be decomposed and faded, and stray light will be easily generated. In contrast, since the optical element of the present invention has the ultraviolet absorbing film of the present invention containing a transition metal oxide, it exhibits excellent durability even against intense ultraviolet light, and can suppress the generation of stray light.

FIG. 4 is a schematic diagram showing a cross section of a mirror box as an example of the optical element of the present invention. Generally, in a mirror box, as shown in FIG. 4 , ultraviolet light from an entrance port of the mirror box is emitted from an exit port. , part of the incident UV light I The stray light S is generated by reflection on the inner wall surface of the mirror box. In contrast, in the mirror box MB shown in FIG. 4, since the inner wall surface of the mirror box MB has the ultraviolet absorbing film A on the inner wall surface other than the mirror portion, the edges of the entrance or exit, Therefore, it is possible to effectively absorb the ultraviolet light on the inner surfaces other than the mirror surface M, and to suppress the generation of stray light (for convenience, the stray light generated when the mirror box MB does not have the ultraviolet absorbing film A is indicated by a dotted line in FIG. 4 ) Astigmatism S).

In addition, although not shown in the figure, the optical element of the present invention may be an optical element in which the ultraviolet absorbing film of the present invention is provided on surfaces other than the incident surface, the output surface, and the reflection surface of the radium.

In the optical element of the present invention, in a device capable of outputting ultraviolet light having a high light energy at high intensity, even when it is used for absorbing ultraviolet light, when it is used for absorbing visible light or infrared light at the same time as absorbing ultraviolet light Even in this case, the generation of stray light can be suppressed with a thin film height.

Next, the optical unit of the present invention will be described.

The optical unit of the present invention is characterized by having the optical element of the present invention.

The details of the optical element of the present invention are as described above.

The optical unit of the present invention is not particularly limited as long as it includes the optical element of the present invention.

The optical unit of the present invention generally has an optical element and a light source.

The light source is not particularly limited as long as it can irradiate light including ultraviolet light, and examples thereof include at least one selected from discharge lamps such as ultraviolet LEDs (UV-LEDs), short arc lamps, and long arc lamps.

Fig. 5 is a diagram illustrating an optical unit of the present invention, the upper diagram of Fig. 5 is a schematic diagram viewed from the upper side, and the lower diagram of Fig. 5 is a schematic cross-sectional diagram viewed from the side.

In the optical unit shown in Fig. 5, four ultraviolet LEDs (LED wafer D) are arranged on the substrate B, and the first lens L1, the second lens L2 and the third lens are arranged in order from the ultraviolet LED side (irradiation side) to the exit side. The edge of the first lens L1, the second lens L2 and the third lens L3 has the ultraviolet absorbing film of the present invention.

The optical unit of the present invention can highly suppress stray light even when used in a device capable of outputting ultraviolet light with high light energy at high intensity, or when absorbing visible light or infrared light while absorbing ultraviolet light. generated, and simultaneously irradiated with light.

Next, the light irradiation apparatus of this invention is demonstrated.

The light irradiation apparatus of this invention has the optical unit of this invention, It is characterized by the above-mentioned.

The details of the optical unit of the present invention are as described above.

Examples of the light irradiation device of the present invention include a point type ultraviolet light source, a line type ultraviolet light source, a surface type ultraviolet light source, a light guide type ultraviolet light source, and a light source device for peripheral exposure.

The light irradiation device of the present invention contains one or more optical units of the present invention, and usually contains two or more optical units of the present invention.

FIG. 6 is a plan view illustrating the light irradiation device of the present invention. In the example shown in FIG. 6 , the light irradiation device includes 25 optical elements shown in FIG. 5 . Unit U, when in use, these optical units can work together to irradiate the object to be irradiated.

Even if the light irradiation device of the present invention is a device capable of outputting ultraviolet light with high light energy at high intensity, or a device capable of outputting ultraviolet light and visible light or infrared light, the optical unit of the present invention can highly suppress stray light The generation of stray light can be highly suppressed from mixing into the original illumination light.

[Example]

Hereinafter, the present invention will be further described with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

(Example 1)

In a glass vessel, 19.4 g of ethylene glycol (indicative formula: C ₂ H ₄ (OH) ₂ ) and 12.6 g of iron (III) nitrate nonahydrate (indicative formula: Fe(NO ₃ ) ₃ 9H ₂ O) were added g, use a magnetic stirrer to stir at room temperature for 2 hours, dissolve iron (III) nitrate nonahydrate in ethylene glycol, and then add isopropanol (representative formula: CH ₃ CH(OH)CH ₃ ) 68.0 g , and further stirred at room temperature for 2 hours, thereby preparing 100 g of a brown transparent and uniform coating liquid for forming an absorbing film _{( FexOy} -based ultraviolet absorbing paint).

The solid content in the obtained coating liquid for forming an absorption film was 2.5 mass % in terms of Fe ₂ O ₃ assuming that the coating liquid was heat-treated to form oxides of all iron nitrate.

The coating liquid for absorbing film formation was applied to both surfaces of a glass sheet substrate (S1127, manufactured by Matsunami Glass Co., Ltd., length 76 mm×width 26 mm×thickness 1.0-1.2 mm) by a dipping method at a lifting speed of 30 cm/min. The resulting film is pale orange Colored transparent uniform film.

The glass sheet substrate with the thin film was dried at 70°C for 1 hour, then placed in a heat treatment furnace, heated from room temperature to 500°C at 200°C/hour in the atmosphere, and kept at 500°C for 1 hour. This forms an iron oxide _{( FexOy} )-based ultraviolet absorbing film on the glass sheet substrate. The thickness of the obtained ultraviolet-absorbing film was less than 1 μm.

By the above-mentioned heat treatment, the thin film changed from light orange to dark orange, the obtained ultraviolet absorbing film was uniform, and the occurrence of cracks and peeling was not confirmed.

Fig. 7 shows the transmittance curves of the obtained substrate with the ultraviolet absorbing film and the substrate without the ultraviolet absorbing film.

The dotted line in Fig. 7 is the transmittance curve of the substrate alone (without the ultraviolet absorbing film), and the solid line is the transmittance curve of the substrate with the _{FexOy -} based ultraviolet absorbing film. Absorption by iron oxides constituting the ultraviolet absorbing film occurs in the region, so the transmittance of the solid line (with the ultraviolet absorbing film) is highly suppressed in the entire ultraviolet region compared to the dotted line (substrate alone).

(Evaluation of ultraviolet absorption effect)

In the state where the optically polished surface of the quartz glass substrate (length 20mm x width 50mm x thickness 2mm, length 20mm x width 50mm is the optically polished surface, and the other major surface is the #1000 frosted surface) with masking tape, pass The above-mentioned coating liquid for absorbing film formation was applied to the frosted surface by a dipping method at a lifting speed of 30 cm/min.

The masking tape was peeled off from the quartz glass substrate with the thin film, dried at 70°C for 1 hour, placed in a heat treatment furnace, heated from room temperature to 500°C at 200°C/hour, and held at 500°C for 1 hour, thereby An iron oxide _{( FexOy} )-based ultraviolet absorbing film was formed on the frosted surface of the quartz glass substrate. The obtained iron oxide _{( FexOy} )-based ultraviolet absorbing film had a film thickness of less than 1 μm.

Using the obtained quartz glass substrate with an ultraviolet absorbing film, as schematically shown in FIG. (The upper part of Fig. 8 is a schematic diagram showing the entire measurement system, and the lower part of Fig. 8 is a schematic diagram of an enlarged portion surrounded by a circle in the upper figure).

That is, (1) the quartz glass substrate G (length 20 mm×width 50 mm×thickness 2 mm, length 20 mm) is placed on the light receiver R including the light receiving portion LR so as to have the arrangement shown in FIG. 8 . The main surface with a width of 50mm is the optically polished surface P, the other main surface is the #1000 frosted surface W), and the output of the UV-LED light source (peak wavelength 365nm) is adjusted so that the edge of the quartz glass substrate is viewed from the side When the ultraviolet light I is irradiated horizontally, the display value of the light-receiving part LR is 10.00 mW/cm ² , (2) Next, as shown in FIG. and the quartz glass substrate G with the optical polishing surface P as the main surface (length 20mm×width 50mm×thickness 2mm, the main surface of the length 20mm×width 50mm is the optical polishing surface P, and the other main surface is the #1000 frosted surface W), and In the same manner as described above, the end side of the quartz glass substrate was irradiated with the ultraviolet light I horizontally, and at this time, (3) the incident light was internally reflected in the quartz glass substrate and absorbed by the ultraviolet absorption film C at the same time, and the output to the light-receiving part LR was measured. The ratio of the intensity Il of the outgoing light on the side to the intensity IO of the incident light ((Il/IO)×100).

As a result, the intensity (Il) of the outgoing light to the photoreceptor R side was 10.00 mW/cm ² when the quartz glass substrate without the ultraviolet absorbing film was used. In the case of the quartz glass substrate G of C, the intensity (I1) of the outgoing light to the photoreceptor R side is 0.20 mW/cm ² , and the intensity I1 of the outgoing light to the photoreceptor R side is relative to the intensity IO of the incident light. The ratio ((Il/IO)×100) was 2.0%.

(Durability Evaluation)

As shown in Fig. 9, the same quartz glass substrate with an ultraviolet absorbing film as the quartz glass substrate with an ultraviolet absorbing film used in the above-mentioned "Evaluation of the ultraviolet absorbing effect" was prepared from the frosted surface provided with the ultraviolet absorbing film C. When the surface W side was incident at an incident angle of 90° and an intensity of 2000 mW/cm ² for 5000 hours, no cracks or peeling occurred in the ultraviolet absorbing film C, and the transmittance did not change before and after ultraviolet light irradiation.

(Example 2)

To a mixed solution of 23.6 g of tetraethoxysilane (representative formula: Si(C ₂ H ₅ O) ₄ ) and 18.9 g of isopropanol, a mixture of 16.0 g of a 0.7% by mass hydrochloric acid aqueous solution and 18.9 g of isopropanol was slowly added The solution was stirred for 2 hours, then 22.6 g of chromium (III) nitrate nonahydrate (representative formula: Cr(NO ₃ ) ₃ .9H ₂ O) was added, and further stirred for 2 hours, thereby preparing a navy blue transparent and uniform 100 g of the coating liquid for absorbing film formation (chromium oxide-SiO ₂ type (Cr _x O _y -SiO ₂ type) ultraviolet absorbing paint).

Assuming that the coating liquid was heat-treated to produce all of Cr ₂ O ₃ from chromium (III) nitrate and all of SiO ₂ from tetraethoxysilane, the solid content in the resulting coating liquid for forming an absorption film contained 20 mols % of Cr ₂ O ₃ , 80 mol % of SiO ₂ , and the solid content in the coating solution (assuming that all oxides are formed by heat treatment) is converted into 20Cr ₂ O ₃ . 80SiO ₂ was 11.1 mass %.

The coating liquid for absorbing film formation was applied on both sides of a glass sheet substrate (manufactured by Matsunami Glass Industry Co., Ltd., S1127, length 76 mm×width 26 mm×thickness 1.0-1.2 mm) by a dipping method at a lifting speed of 30 cm/min. The obtained thin film was a transparent and uniform film showing light navy blue.

Using the same conditions as in Example 1, that is, drying the glass sheet substrate with the thin film at 70°C, then placing it in a heat treatment furnace, and heating it from room temperature to 500°C at 200°C/hour in the atmosphere, and At 500°C for 1 hour, a chromium oxide-SiO ₂ type (Cr _x O _y -SiO ₂ type) ultraviolet absorbing film was formed on the glass sheet substrate. The thickness of the obtained chromium oxide-SiO ₂ type (Cr _x O _y -SiO ₂ type) ultraviolet absorbing film was less than 1 μm.

By the above-mentioned heat treatment, the thin film changed from light navy blue to dark green, and the obtained ultraviolet absorbing film was uniform, and the occurrence of cracks and peeling was not confirmed.

Fig. 10 shows the transmittance curves of the obtained substrate with the ultraviolet absorbing film and the substrate without the ultraviolet absorbing film.

The dotted line in Fig. 10 is the transmittance curve of the substrate alone (without the ultraviolet absorbing film), and the solid line is the transmittance curve of the substrate with the Cr _x O _y -SiO ₂ type ultraviolet absorbing film. Absorption occurs in the ultraviolet region of the solid line (with the ultraviolet absorbing film) due to the chromium oxide constituting the ultraviolet absorbing film, so the transmittance of the solid line (with the ultraviolet absorbing film) is highly suppressed in the entire ultraviolet region compared with the dotted line (substrate alone).

Using the coating liquid for forming an absorption film, the ultraviolet absorption effect was evaluated in the same manner as in Example 1. As a result, when the quartz glass substrate G on which the ultraviolet absorption film C was formed was used, the outgoing light was emitted to the side of the light receiver R. The intensity (Il) of the light was 0.19 mW/cm ² , and the ratio ((Il/IO)×100) of the intensity Il of the outgoing light to the light receiver R side to the intensity IO of the incident light was 1.9%.

In addition, the durability was evaluated in the same manner as in Example 1, and as a result, as shown in FIG. 9, an incident angle of 90° was applied to the quartz glass substrate with an ultraviolet absorbing film from the frosted surface side on which the ultraviolet absorbing film C was provided. , 2000mW/cm ² intensity of incident for 5000 hours, the ultraviolet absorbing film C did not crack or peel, and the transmittance did not change before and after ultraviolet light irradiation.

(Example 3)

In a glass vessel, 4.1 g of polyvinylpyrrolidone K-90 was gradually added to 85.1 g of 2-methoxyethanol (representative formula: CH ₃ OCHCH ₂ OH), followed by stirring for 2 hours to dissolve polyvinyl pyrrolidone in 2-methyl methacrylate. oxyethanol. To this solution, 10.6 g of manganese (II) nitrate hexahydrate (representative formula: Mn(NO ₃ ) ₂ 6H ₂ O) was added, and the solution was further stirred for 2 hours, thereby preparing a very light brown uniform absorption film. 100 g of a coating liquid for formation (manganese oxide-based (Mn _x O _y -based)) ultraviolet absorbing paint.

Assuming that the coating liquid was heat-treated to generate Mn ₂ O ₃ from all the manganese (II) nitrate, the solid content in the obtained coating liquid for forming an absorber film was 2.9 mass % in terms of Mn ₂ O ₃ .

The coating liquid for absorbing film formation was applied on both surfaces of a glass sheet substrate (manufactured by Matsunami Glass Co., Ltd., S1127, length 76 mm×width 26 mm×thickness 1.0 to 1.2 mm) by a dipping method at a lifting speed of 20 cm/min. The obtained thin film was a colorless, transparent and uniform film.

Using the same conditions as in Example 1, that is, drying the glass sheet substrate with the thin film at 70°C, then placing it in a heat treatment furnace, and heating it from room temperature to 500°C at 200°C/hour in the atmosphere, and At 500° C. for 1 hour, a manganese oxide-based (Mn _x O _y -based) ultraviolet-absorbing film with a thickness of 1.2 μm was formed on the glass sheet substrate.

By the above-mentioned heat treatment, the thin film changed from colorless and transparent to dark brown, and the obtained ultraviolet absorbing film was uniform, and the occurrence of cracks and peeling was not confirmed.

Fig. 11 shows the transmittance curves of the obtained substrate with the ultraviolet absorbing film and the substrate without the ultraviolet absorbing film.

The dotted line in Fig. 11 is the transmittance curve of the substrate alone (without the ultraviolet absorbing film), and the solid line is the transmittance curve of the substrate with the Mn _x O _y type ultraviolet absorbing film. Absorption occurs in the region due to the manganese oxide constituting the UV-absorbing film, so the transmittance of the solid line (with the UV-absorbing film) is highly suppressed in the entire UV region compared to the dotted line (substrate alone) (it should be noted that Yes, in Fig. 11, the transmittance of the substrate with the _MnxOy -based ultraviolet absorbing film is 0% in the entire measurement wavelength region, so the horizontal axis in Fig. 11 _is the same as the one with the _{MnxOy -} based ultraviolet absorbing film. The transmittance curves of the substrates are superimposed).

Using the coating liquid for forming an absorption film, the ultraviolet absorption effect was evaluated in the same manner as in Example 1. As a result, when the quartz glass substrate G on which the ultraviolet absorption film C was formed was used, the outgoing light was emitted to the side of the light receiver R. The intensity (I1) of the light was 0.15 mW/cm ² , and the ratio ((I1/IO)×100) of the intensity I1 of the outgoing light to the light receiver R side to the intensity IO of the incident light was 1.5%.

In addition, the durability was evaluated in the same manner as in Example 1, and as a result, as shown in FIG. 9, an incident angle of 90° was applied to the quartz glass substrate with an ultraviolet absorbing film from the frosted surface side on which the ultraviolet absorbing film C was provided. , 2000mW/cm ² intensity of incident for 5000 hours, the ultraviolet absorbing film C did not crack or peel, and the transmittance did not change before and after ultraviolet light irradiation.

(Example 4)

To a mixed solution of 25.2 g of tetraethoxysilane (representative formula: Si(C ₂ H ₅ O) ₄ ) and 20.2 g of isopropanol, a mixed solution of 17.1 g of a 0.7% by mass hydrochloric acid aqueous solution and 20.2 g of isopropanol was slowly added , stirred for 2 hours, then added 17.3 g of manganese (II) nitrate hexahydrate, and further stirred for 2 hours, thereby preparing a colorless, transparent and uniform coating solution for forming an absorption film (manganese oxide-SiO ₂ system (Mn _x O _y -SiO ₂ series) UV absorbing paint) 100 g.

Assuming that the coating liquid was heat-treated to form all of the manganese (II) nitrate to form Cr ₂ O ₃ and all of the tetraethoxysilane to form SiO ₂ , the solid content in the obtained coating liquid for forming an absorption film contained 20 mols. % Mn ₂ O ₃ , 80 mol % SiO ₂ , and the solid content in the coating solution (assuming that all oxides are generated by heat treatment) is converted into 20Mn ₂ O ₃ . 80SiO ₂ is 12.0 mass %.

The coating liquid for absorbing film formation was applied on both sides of a glass sheet substrate (manufactured by Matsunami Glass Industry Co., Ltd., S1127, length 76 mm×width 26 mm×thickness 1.0-1.2 mm) by a dipping method at a lifting speed of 30 cm/min. The obtained thin film was a colorless, transparent and uniform film.

Using the same conditions as in Example 1, that is, drying the glass sheet substrate with the thin film at 70°C, then placing it in a heat treatment furnace, and heating it from room temperature to 500°C at 200°C/hour in the atmosphere, and At 500°C for 1 hour, a manganese oxide-SiO ₂ type (Mn _x O _y -SiO ₂ type) ultraviolet absorbing film was formed on the glass sheet substrate. The obtained manganese oxide-SiO ₂ type (Mn _x O _y -SiO ₂ type) ultraviolet absorbing film had a film thickness of less than 1 μm.

By the above-mentioned heat treatment, the thin film changed from colorless and transparent to brown, and the obtained ultraviolet absorbing film was uniform, and the occurrence of cracks and peeling was not confirmed.

Fig. 12 shows the transmittance curves of the obtained substrate with the ultraviolet absorbing film and the substrate without the ultraviolet absorbing film.

The dotted line in Fig. 12 is the transmittance curve of the substrate alone (without the ultraviolet absorbing film), and the solid line is the transmittance curve of the substrate with the Mn _x O _y -SiO ₂ type ultraviolet absorbing film. Absorption occurs in the ultraviolet region of the solid line (with the ultraviolet absorption film) due to the manganese oxide constituting the ultraviolet absorption film, so the transmittance of the solid line (with the ultraviolet absorption film) is highly suppressed in the entire ultraviolet region compared with the dotted line (substrate alone)

Using the coating liquid for forming an absorption film, the ultraviolet absorption effect was evaluated in the same manner as in Example 1. As a result, when the quartz glass substrate G on which the ultraviolet absorption film C was formed was used, the outgoing light was emitted to the side of the light receiver R. The intensity (I1) of the light was 0.21 mW/cm ² , and the ratio ((I1/IO)×100) of the intensity I1 of the outgoing light to the light receiver R side to the intensity IO of the incident light was 2.1%.

In addition, the durability was evaluated in the same manner as in Example 1, and as a result, as shown in FIG. 9, an incident angle of 90° was applied to the quartz glass substrate with an ultraviolet absorbing film from the frosted surface side on which the ultraviolet absorbing film C was provided. , 2000mW/cm ² intensity of incident for 5000 hours, the ultraviolet absorbing film C did not crack or peel, and the transmittance did not change before and after ultraviolet light irradiation.

(Comparative Example 1)

Using a commercially available antireflection coating (GT-7II manufactured by CANON CHEMICALS Co., Ltd.) instead of the coating liquid for forming an absorption film, the ultraviolet absorption effect was evaluated in the same manner as in Example 1. The intensity (I1) of the outgoing light was 0.19 mW/cm ² , and the ratio ((I1/IO)×100) of the intensity I1 of the outgoing light to the light receiver R side to the intensity IO of the incident light was 1.9%.

On the other hand, when the durability was evaluated in the same manner as in Example 1, the color became lighter (from black to gray) as the ultraviolet light irradiation time passed, and peeling occurred when the irradiation time was 1000 hours.

The results of Examples 1 to 4 and Comparative Example 1 are summarized in Table 1.

As can be seen from Table 1, since the ultraviolet absorbing films obtained in Examples 1 to 4 contain oxides of specific transition metals, in a device capable of outputting ultraviolet light with high luminous energy at high intensity, even in a device that absorbs ultraviolet light In the case of use, it is also possible to form an ultraviolet absorbing film that can highly suppress the generation of stray light in a thin film state and can exhibit excellent durability.

In contrast, as can be seen from Table 1, the coating film obtained from the commercially available antireflection paint used in Comparative Example 1 contains an organic resin and does not contain a specific transition metal. Oxide, therefore, discoloration and peeling occurred in the durability test by irradiation with ultraviolet light.

(Example 5)

In Example 3, except that the addition amount of manganese (II) nitrate hexahydrate (representative formula: Mn(NO ₃ ) ₂ 6H ₂ O) was changed from 10.6 g to 12.7 g, the same as in Example 3 In the same manner, 100 g of a light brown uniform coating liquid for absorbing film formation (manganese oxide-based (Mn _x O _y -based) ultraviolet absorbing paint) was prepared.

Assuming that the coating liquid was heat-treated to generate Mn ₂ O ₃ from all the manganese (II) nitrate, the solid content in the obtained coating liquid for absorbing film formation was 3.5 mass % in terms of Mn ₂ O ₃ .

In the same manner as in Example 3, this absorbing film formation was applied to both sides of a glass sheet substrate (manufactured by Matsunami Glass Co., Ltd., S1127, length 76 mm × width 26 mm × thickness 1.0 to 1.2 mm) by the dipping method at a lifting speed of 5 cm/min. coating liquid. The obtained thin film was a colorless, transparent and uniform film.

The glass sheet substrate with the film was dried at 130°C for 1 hour to change the state of the film from colorless and transparent to a light brown transparent and uniform state, and then put into a heat treatment furnace and heated at 200°C/200°C in the atmosphere. The temperature was raised from room temperature to 450°C for 1 hour, and maintained at 450°C for 1 hour, whereby a manganese oxide-based _{( MnxOy} -based) ultraviolet absorbing film with a thickness of 1.0 μm was formed on the glass sheet substrate.

By the above-mentioned heat treatment, the thin film changed from colorless and transparent to dark brown, and the obtained ultraviolet absorbing film was uniform, and the occurrence of cracks and peeling was not confirmed.

(Example 6)

In the same manner as in Example 5, 3.5% by mass of manganese (II) nitrate hexahydrate (representative formula: Mn(NO ₃ ) ₂ 6H ₂ O) in terms of Mn ₂ O ₃ was added to prepare 100 g of a coating solution for forming an extremely light brown uniform absorption film (manganese oxide-based (Mn _x O _y system) ultraviolet absorbing paint), and 0.50 g of methylene blue trihydrate as a colorant was added to the coating solution. , and stirred at room temperature for 1 hour to prepare a colorant-containing coating liquid for forming an absorption film. The obtained coating liquid was a deep navy blue uniform liquid.

In the same manner as in Example 5, the absorption film formation was applied to both sides of a glass sheet substrate (S1127, manufactured by Matsunami Glass Industry Co., Ltd., 76 mm in length, 26 mm in width, and 1.0 to 1.2 mm in thickness) by a dipping method at a lifting speed of 5 cm/min. coating liquid. The obtained thin film was a blue transparent and uniform film.

In the same manner as in Example 5, the above-mentioned glass sheet substrate with a thin film was dried at 130° C. for 1 hour to change the state of the above-mentioned thin film from blue and transparent to a bluish, transparent and uniform state with light brown, and then placed. In a heat treatment furnace, the temperature was raised from room temperature to 450°C at 200°C/hour in the atmosphere, and held at 450°C for 1 hour, thereby forming a manganese oxide-based (Mn _x O _y series) UV absorbing film.

By the above-mentioned heat treatment, the thin film changed from blue and transparent immediately after coating to dark brown, and the obtained ultraviolet absorbing film was uniform, and the occurrence of cracks and peeling was not confirmed.

When the coating liquid for forming an absorbing film containing the colorant is applied to the edge of the lens, a blue transparent coating film can be easily formed, and the presence or absence of the coating film can be easily confirmed with the naked eye. In addition, it is also possible to easily confirm whether or not a small amount of the coating liquid adheres to the incident surface and the output surface of the lens where the adhesion of the coating liquid is restricted.

Fig. 13 is a diagram showing two transmittance curves as follows: The transmittance curve (dotted line) of the coating film obtained after the coating liquid for forming an absorbing film obtained in Example 5 was applied to a glass sheet and dried at 130° C. for 1 hour, and the coating liquid obtained in Example 6 containing The transmittance curve (solid line) of the coating film immediately after the coating liquid for absorption film formation of a colorant was apply|coated to a glass sheet, and was dried at 130 degreeC for 1 hour.

As can be seen from Fig. 13, since the coating liquid obtained in Example 6 has a colorant, the transmittance in the visible light region is lowered, and the visibility is improved.

FIG. 14 is a graph showing two transmittance curves obtained by applying the coating liquid for forming an absorbing film obtained in Example 5 to a glass sheet, drying it at 130° C. for 1 hour, and then heat-treating it. The transmittance curve (dotted line) of the obtained coating film, and the coating liquid for forming an absorbing film containing a colorant obtained in Example 6 was applied to a glass sheet, dried at 130° C. for 1 hour, and then heat-treated The transmittance curve (solid line) of the obtained coating film.

As shown in FIG. 14, it can be seen that when the coating liquid for forming an absorbing film containing no colorant obtained in Example 5 and the coating liquid for forming an absorbing film containing a coloring agent obtained in Example 6 were applied to glass For any kind of dark brown coating film obtained by drying and then heat treatment, since it shows equal transmittance, even if the coating liquid for absorbing film formation contains a colorant, it will not affect the film obtained after heat treatment. the transmittance of the coating film.

Fig. 15 shows the transmittance curve (dotted line) when the coating liquid for forming an absorbing film obtained in Example 5 was placed in a measuring cell made of acrylic resin with an optical path length of 10 mm and measured, and the obtained A graph of the transmittance curve (solid line) when the colorant-containing coating liquid for forming an absorbing film was placed in a measuring cell made of acrylic resin with an optical path length of 10 mm (in Fig. 15, obtained in Example 6) The transmittance of the obtained coating liquid for forming an absorption film containing a colorant was substantially 0% in the entire visible light region, and the transmittance curve was in a state where the horizontal axis was substantially overlapped).

As can be seen from Fig. 15, since the thickness of the measurement object is larger than that of the coating film measured in Fig. 13, in Example 6, it can be clearly recognized that the transmittance in the visible light region decreases due to the presence of the colorant in the coating solution. (visibility improvement) effect.

(Example 7)

As shown in FIG. 5, four UV-LED wafers (light emission wavelength: 395 nm) D of 1 mm long and 1 mm wide are arranged adjacent to each other on the substrate B as light sources, and the UV-LED side (light emission side) light irradiation side The first lens L1, the second lens L2 and the third lens L3 are arranged in order to form an optical unit.

As shown in Fig. 5, the above-mentioned first lens L1, second lens L2 and third lens L3 were coated with the ultraviolet absorbing paint prepared in Example 3 on the entire edge, and then dried at 100°C for 1 hour, and then It was placed in a heat treatment furnace, heated from room temperature to 450°C at 200°C/hour in the atmosphere, and held at 450°C for 1 hour to form a manganese oxide-based ultraviolet absorbing film with a thickness of 1.5 μm on the edges.

Next, as shown in FIG. 6 , a light irradiation device (a light source device for peripheral exposure) was produced by arranging 25 of the above-mentioned optical units in a plane of 5×5.

As schematically shown in FIG. 16( a ), a silicon for semiconductor silicon obtained by coating the entire main surface with a photoresist film 1 a having a thickness of 3 μm under the condition of an accumulated light amount of 25 mJ using the above-mentioned light irradiation device The peripheral portion of the wafer 1 is exposed (peripheral exposure is performed), and then the unnecessary resist on the peripheral portion of the wafer is removed using a chemical agent agent film.

When performing the above-mentioned peripheral exposure, it is desirable to remove the resist film 1a as wide as possible from the edge (end) of the wafer 1 shown in FIG. 16(a), and to expand the resist film 1a as much as possible. Therefore, in the area near the outer periphery of the silicon wafer 1, as schematically shown in FIG. 16(b), for the resist film 1a, the edge portion E is ideally sharpened The way (in the way of steep rise) is removed as far as possible at right angles.

In contrast, as schematically shown in FIG. 16( c ), in the silicon wafer 1 obtained by the above-mentioned peripheral exposure treatment, the edge of the photoresist film is sharpened (with The sag width d of the edge portion E (the lateral width of the portion formed by the inclined portion) was 31 μm (about 10 times the film thickness), except for the steep rise.

The photoresist film of the peripheral part of the silicon wafer for semiconductors was exposed to light by using the above-mentioned light irradiation apparatus continuously for 5000 hours, and the obtained silicon wafer was made such that the edge part of the photoresist film became Removed in a sharp manner (in a manner of steep rise), the sag width d was 30 μm, which was equal to that before continuous use.

(Comparative Example 2)

In Example 7, the optical unit was formed in the same manner as in Example 7, except that the first lens, the second lens, and the third lens forming the optical unit were all lenses that did not have an ultraviolet absorbing film. Example 7 In the same manner, 25 of the optical units were arranged in a plane of 5×5, whereby a light irradiation device (a light source device for peripheral exposure) was produced.

In the same manner as in Example 5, the obtained light irradiation device was used to accumulate light The peripheral portion of a silicon wafer for semiconductors obtained by coating the entire main surface with a photoresist film with a thickness of 3 μm was exposed under the condition of an amount of 25 mJ (peripheral exposure was performed), and then the unnecessary parts of the peripheral portion of the wafer were removed using a chemical agent. resist film.

As schematically shown in FIG. 16(d), the silicon wafer obtained by the above-mentioned treatment is formed by generating a gently inclined sag in the edge portion E of the photoresist film 1a and removing the sag, and the width of the sag is formed. d is 120 μm (40 times the film thickness).

Since silicon wafers are processed while keeping their peripheral portions, if a resist film is also applied to the peripheral portions of the wafers, the resist film peels off during wafer processing and particles are generated, resulting in a decrease in yield. Therefore, it is desirable to remove the unnecessary resist film in the peripheral portion of the wafer in advance.

Therefore, in the case of removing the resist film in the peripheral portion of the silicon wafer, it is desirable to remove the resist film as wide as possible from the edge (edge) of the silicon wafer, from the viewpoint of suppressing the generation of the above-mentioned particles. On the one hand, it is desired to expand the area where the resist film can be used as much as possible. Therefore, in the vicinity of the outer periphery of the silicon wafer, it is required to remove the resist film so that the edge portion becomes sharp (with a steep rise).

However, conventionally, when a resist film is removed by exposure using a light irradiation device, stray light generated by optical elements/optical elements such as lenses is mixed with the original exposure light, and the edge portion of the resist film is easily Produces a gently sloping sag.

It was found that the light irradiation device obtained in Example 7 includes the optical element or optical unit having the ultraviolet absorbing film of the present invention, and thus can not only highly suppress the generation of stray light, but also exhibit excellent durability.

On the other hand, it was found that the light irradiation device obtained in Comparative Example 2 did not contain In the optical element or optical unit having the ultraviolet absorbing film of the present invention, generation of stray light cannot be suppressed, and sagging occurs in the edge portion of the resist film.

Industrial Applicability

ADVANTAGE OF THE INVENTION According to the present invention, it is possible to provide an ultraviolet absorbing paint capable of forming a coating film that can highly suppress the generation of stray light in a thin film state and exhibit excellent durability, and can also provide an ultraviolet absorbing film and a light absorbing film formed from the ultraviolet absorbing paint, An optical element obtained by forming the ultraviolet absorbing film on the surface, an optical unit having the optical element, and a light irradiation device having the optical unit.

A: UV absorbing film

I: UV light

L: lens

S: Stray Light

Claims (6)

An optical element for an ultraviolet light irradiation device, having only an ultraviolet absorbing film on its ridge or its peripheral portion, the ultraviolet absorbing film containing 20 to 100 mass % of one or more transition metals selected from Cr, Mn and Ni of oxides. The optical element for an ultraviolet light irradiation device as described in claim 1, wherein the ultraviolet absorbing film further contains silicon oxide or aluminum oxide. The optical element for an ultraviolet light irradiation device according to any one of claims 1 to 2, wherein the film thickness of the ultraviolet absorbing film is 50 μm or less. An optical element for an ultraviolet light irradiation device only has a light absorbing film on its ridgeline or its peripheral portion, the light absorbing film comprises a laminate, and the laminate contains 20 to 100 mass % of selected materials. A laminate of an ultraviolet absorbing film made of oxides of one or more transition metals among Cr, Mn, and Ni, and an absorbing film that absorbs at least visible light or infrared light. An optical unit for an ultraviolet light irradiation device, which has the optical element for an ultraviolet light irradiation device as described in any one of items 1 to 4 of the patent application scope. An ultraviolet light irradiation device has an optical unit for the ultraviolet light irradiation device as described in item 5 of the patent application scope.

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