JP6778222B2 - Optical filter and camera module - Google Patents

Description

The present invention relates to an optical filter.

In an image pickup device using an image sensor such as a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor), various optical filters are arranged in front of the image sensor in order to obtain an image having good color reproducibility. There is. Generally, the image sensor has spectral sensitivity in a wide wavelength range from the ultraviolet region to the infrared region. On the other hand, human luminosity factor exists only in the visible light region. Therefore, in order to bring the spectral sensitivity of the image sensor in the image sensor closer to the human visual sensitivity, there is known a technique of arranging an optical filter that shields infrared rays or ultraviolet rays in front of the image sensor.

The optical filter includes an optical filter that utilizes light reflection, such as an optical filter having a dielectric multilayer film, and an optical filter that has a film containing a light absorber capable of absorbing light of a predetermined wavelength. There is an optical filter that utilizes light absorption. The latter is desirable in that it has a spectral characteristic that does not easily fluctuate with respect to the incident angle of the incident light.

For example, Patent Document 1 describes a near-infrared absorbing filter formed of a near-infrared absorbing agent and a resin. The near-infrared absorber is obtained from a predetermined phosphonic acid compound, a predetermined phosphoric acid ester compound, and a copper salt. A given phosphonic acid compound has a monovalent group R ¹ represented by −CH ₂ CH ₂ −R ¹¹ attached to the phosphorus atom P. R ¹¹ is a hydrogen atom with 1 to 20 carbon atoms
Alkyl group, or fluorinated alkyl group having 1 to 20 carbon atoms.

Japanese Unexamined Patent Publication No. 2011-203467

Although the near-infrared absorption filter described in Patent Document 1 can effectively absorb light at a wavelength of 800 nm to 1200 nm, it cannot be said that it has desirable light absorption characteristics at a wavelength of 350 nm to 400 nm and a wavelength of 650 nm to 800 nm. .. Therefore, the present invention provides an optical filter capable of exhibiting desired optical performance that is difficult to achieve only with the near-infrared absorbing filter described in Patent Document 1 in a simple configuration.

The present invention
It has a UV-IR absorption layer that can absorb some infrared rays and ultraviolet rays.
When light with a wavelength of 300 nm to 1200 nm is incident at an incident angle of 0 °,
It has an average transmittance of 78% or more at wavelengths of 450 nm to 600 nm.
The first IR cutoff wavelength, which has a spectral transmittance that decreases with increasing wavelength at a wavelength of 600 nm to 750 nm and exhibits a spectral transmittance of 50% at a wavelength of 600 nm to 750 nm, exists in the wavelength range of 620 nm to 680 nm.
The first UV cutoff wavelength, which has a spectral transmittance that increases with an increase in wavelength at a wavelength of 350 nm to 450 nm and exhibits a spectral transmittance of 50% at a wavelength of 350 nm to 450 nm, exists in the wavelength range of 380 nm to 430 nm.
The difference between the second IR cutoff wavelength, which shows a spectral transmittance of 50% at a wavelength of 600 nm to 750 nm, and the first IR cutoff wavelength when light having a wavelength of 300 nm to 1200 nm is incident at an incident angle of 40 °. The absolute value is 10 nm or less,
The difference between the second UV cutoff wavelength, which shows 50% spectral transmission at a wavelength of 350 nm to 450 nm when light with a wavelength of 300 nm to 1200 nm is incident at an incident angle of 40 °, and the first UV cutoff wavelength. Absolute value is 10 nm or less,
An optical filter is provided.

The above optical filter can exhibit desired optical performance in a simple configuration.

FIG. 1A is a cross-sectional view showing an example of the optical filter of the present invention. FIG. 1B is a cross-sectional view showing another example of the optical filter of the present invention. FIG. 1C is a cross-sectional view showing still another example of the optical filter of the present invention. FIG. 1D is a cross-sectional view showing still another example of the optical filter of the present invention. FIG. 1E is a cross-sectional view showing still another example of the optical filter of the present invention. FIG. 1F is a cross-sectional view showing still another example of the optical filter of the present invention. FIG. 2 is a cross-sectional view showing an example of a camera module provided with the optical filter of the present invention. FIG. 3 is a transmittance spectrum of the optical filter according to the first embodiment. FIG. 4 is a transmittance spectrum of the optical filter according to the second embodiment. FIG. 5 is a transmittance spectrum of the optical filter according to Example 16. FIG. 6 is a transmittance spectrum of the optical filter according to Example 17. FIG. 7 is a transmittance spectrum of the optical filter according to Example 18. FIG. 8A is a transmission spectrum of the infrared absorbing glass substrate used in Example 21. FIG. 8B is a transmission spectrum of the optical filter according to the twenty-first embodiment. FIG. 9 is a transmittance spectrum of the optical filter according to the 22nd embodiment. FIG. 10 is a transmittance spectrum of the optical filter according to the 23rd embodiment. FIG. 11 is a transmittance spectrum of the optical filter according to the 24th embodiment. FIG. 12 is a transmittance spectrum of the optical filter according to the 38th embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following description relates to an example of the present invention, and the present invention is not limited thereto.

It may be desirable that the optical filter has a property of transmitting light having a wavelength of 450 nm to 600 nm and cutting light having a wavelength of 300 nm to 400 nm and a wavelength of 650 nm to 1100 nm. However, for example, the optical filter described in Patent Document 1 does not have sufficient light absorption characteristics at a wavelength of 350 nm to 400 nm and a wavelength of 650 nm to 800 nm, and emits light having a wavelength of 350 nm to 400 nm and light having a wavelength of 650 nm to 800 nm. A separate light absorbing layer or light reflecting film is required to cut. As described above, it is not easy to realize an optical filter having the above-mentioned desirable characteristics with a simple structure (for example, a single layer). In fact, the present inventor has repeated trial and error in order to realize an optical filter having the above-mentioned desired characteristics with a simple configuration. As a result, the present inventor has finally devised an optical filter according to the present invention.

As shown in FIG. 1A, the optical filter 1a includes a UV-IR absorption layer 10. The UV-IR absorption layer 10 is a layer capable of absorbing infrared rays and ultraviolet rays. The optical filter 1a exhibits the following optical performances (i) to (v) when light having a wavelength of 300 nm to 1200 nm is incident at an incident angle of 0 °.
(I) Average transmission rate of 78% or more at wavelengths of 450 nm to 600 nm (ii) Spectral transmission rate of 1% or less at wavelengths of 750 nm to 1080 nm (iii) Spectral transmission rate of 1% or less at wavelengths of 300 nm to 350 nm (iv) Spectrum 600 nm Spectral transmission that decreases with increasing wavelength at ~ 750 nm and first IR cutoff wavelength (v) existing in the range of 620 nm to 680 nm Spectral transmission and wavelength that increases with increasing wavelength at wavelength 350 nm to 450 nm First UV cutoff wavelength in the range of 380 nm to 430 nm

In the present specification, the "spectral transmission rate" is the transmission rate when incident light of a specific wavelength is incident on an object such as a sample, and the "average transmission rate" is the spectral transmission within a predetermined wavelength range. It is an average value of the rate, and the "maximum transmission rate" is the maximum value of the spectral transmission rate within a predetermined wavelength range. Further, in the present specification, the "transmittance spectrum" is a spectrum in which the spectral transmittances at each wavelength within a predetermined wavelength range are arranged in the order of wavelength.

In the present specification, the "IR cutoff wavelength" indicates a spectral transmittance of 50% in a wavelength range of 600 nm or more when light having a wavelength of 300 nm to 1200 nm is incident on an optical filter at a predetermined incident angle. Means wavelength. The "first IR cutoff wavelength" is the IR cutoff wavelength when light is incident on the optical filter at an incident angle of 0 °. The "UV cutoff wavelength" is a wavelength that exhibits 50% spectral transmission in a wavelength range of 450 nm or less when light having a wavelength of 300 nm to 1200 nm is incident on an optical filter at a predetermined incident angle. means. The "first UV cutoff wavelength" is the UV cutoff wavelength when light is incident on the optical filter at an incident angle of 0 °.

Since the optical filter 1a exhibits the above optical performances (i) to (v), the optical filter 1a transmits a large amount of light having a wavelength of 450 nm to 600 nm, and has a wavelength of 300 nm to 400 nm and a wavelength of 650 nm to 1100 nm. Can cut light effectively. Therefore, the transmission spectrum of the optical filter 1a is more suitable for human visual sensitivity than the transmission spectrum of the near-infrared absorption filter described in Patent Document 1. Moreover, the optical filter 1a can exhibit the above optical performances (i) to (v) even if it does not include a layer other than the UV-IR absorbing layer 10.

With respect to the above (i), the optical filter 1a preferably has an average transmittance of 80% or more, and more preferably 82% or more, at a wavelength of 450 nm to 600 nm.

With respect to (iii) above, the optical filter 1a preferably has a wavelength of 300 nm to 360 nm.
Has a spectral transmittance of 1% or less. As a result, the optical filter 1a can cut light in the ultraviolet region more effectively.

With respect to (iv) above, the first IR cutoff wavelength (a wavelength exhibiting a spectral transmission of 50%) preferably exists in the wavelength range of 630 nm to 650 nm. As a result, the transmission spectrum of the optical filter 1a is more suitable for human visual sensitivity.

With respect to (v) above, the first UV cutoff wavelength (wavelength exhibiting 50% spectral transmittance) preferably exists in the wavelength range of 390 nm to 420 nm. As a result, the transmission spectrum of the optical filter 1a is more suitable for human visual sensitivity.

The optical filter 1a preferably exhibits the following optical performance (vi) when light having a wavelength of 300 nm to 1200 nm is incident at an incident angle of 0 °. This makes it possible to block infrared rays having a relatively long wavelength (wavelength 1000 to 1100 nm). Conventionally, a light reflecting film made of a dielectric multilayer film is often used to cut light of this wavelength. However, according to the optical filter 1a, light of this wavelength can be effectively cut without using such a dielectric multilayer film. Even if a light-reflecting film made of a dielectric multilayer film is required, the level of reflection performance required for the light-reflecting film can be lowered, so that the number of laminated dielectrics in the light-reflecting film can be reduced, and the light-reflecting film can be used. The cost required for formation can be reduced.
(Vi) Spectral transmission of 3% or less at wavelengths of 1000 to 1100 nm

The optical filter 1a preferably exhibits the following optical performance (vii) when light having a wavelength of 300 nm to 1200 nm is incident at an incident angle of 0 °. In this case, the longer wavelength (
It can cut infrared rays having (1100 to 1200 nm). As a result, the optical filter 1a can effectively cut light of this wavelength even if the dielectric multilayer film is not used or the number of laminated dielectrics in the dielectric multilayer film is small.
(Vii) Spectral transmittance of 15% or less at wavelengths of 1100 to 1200 nm

For example, in the optical filter 1a, the absolute value of the difference between the second IR cutoff wavelength and the first IR cutoff wavelength is 10 nm or less (optical performance (viii)). The second IR cutoff wavelength is the IR cutoff wavelength when light having a wavelength of 300 nm to 1200 nm is incident on the optical filter 1a at an incident angle of 40 °. In this case, the transmittance characteristic of the optical filter 1a near the first IR cutoff wavelength is unlikely to fluctuate with respect to the incident angle of the light incident on the optical filter 1a. As a result, it is possible to suppress the generation of different colors in the central portion and the peripheral portion of the image obtained by the imaging device in which the optical filter 1a is arranged in front of the imaging element.

In the optical filter 1a, the absolute value of the difference between the second IR cutoff wavelength and the first IR cutoff wavelength is preferably 5 nm or less.

For example, in the optical filter 1a, the absolute value of the difference between the third IR cutoff wavelength and the first IR cutoff wavelength is 15 nm or less (optical performance (ix)). The third IR cutoff wavelength is the IR cutoff wavelength when light having a wavelength of 300 nm to 1200 nm is incident on the optical filter 1a at an incident angle of 50 °. In this case, even if the incident angle of the light incident on the optical filter 1a changes significantly, the change in the transmittance characteristic near the first IR cutoff wavelength of the optical filter 1a can be suppressed. As a result, even if the optical filter 1a is arranged in front of the image pickup device of the image pickup device capable of taking an image with a wide angle of view, a good quality image can be easily obtained.

For example, in the optical filter 1a, the absolute value of the difference between the fourth IR cutoff wavelength and the first IR cutoff wavelength is 20 nm or less. The fourth IR cutoff wavelength is the IR cutoff wavelength when light having a wavelength of 300 nm to 1200 nm is incident on the optical filter 1a at an incident angle of 60 °. In this case, even if the optical filter 1a is arranged in front of the image pickup device of the image pickup device capable of taking an image with a wide angle of view, a good quality image can be easily obtained.

For example, in the optical filter 1a, the absolute value of the difference between the second UV cutoff wavelength and the first UV cutoff wavelength is 10 nm or less (optical performance (x)). The second UV cutoff wavelength is a UV cutoff wavelength when light having a wavelength of 300 nm to 1200 nm is incident on the optical filter 1a at an incident angle of 40 °. In this case, the transmittance characteristic of the optical filter 1a near the first UV cutoff wavelength is unlikely to fluctuate with respect to the incident angle of the light incident on the optical filter 1a. As a result, it is possible to suppress the generation of different colors in the central portion and the peripheral portion of the image obtained by the image pickup device in which the optical filter 1a is arranged in front of the image pickup element.

In the optical filter 1a, the absolute value of the difference between the second UV cutoff wavelength and the first UV cutoff wavelength is preferably 5 nm or less.

For example, in the optical filter 1a, the absolute value of the difference between the third UV cutoff wavelength and the first UV cutoff wavelength is 15 nm or less (optical performance (xi)). The third UV cutoff wavelength is a UV cutoff wavelength when light having a wavelength of 300 nm to 1200 nm is incident on the optical filter 1a at an incident angle of 50 °. In this case, even if the incident angle of the light incident on the optical filter 1a changes significantly, the change in the transmittance characteristic near the first UV cutoff wavelength of the optical filter 1a can be suppressed. As a result, even if the optical filter 1a is arranged in front of the image pickup device of the image pickup device capable of taking an image with a wide angle of view, a good quality image can be easily obtained.

For example, in the optical filter 1a, the absolute value of the difference between the fourth UV cutoff wavelength and the first UV cutoff wavelength is 20 nm or less. The fourth UV cutoff wavelength is a UV cutoff wavelength when light having a wavelength of 300 nm to 1200 nm is incident on the optical filter 1a at an incident angle of 60 °. In this case, even if the optical filter 1a is arranged in front of the image pickup device of the image pickup device capable of taking an image with a wide angle of view, a good quality image can be easily obtained.

The optical filter 1a preferably exhibits the following optical performance (xii) when light having a wavelength of 300 nm to 1200 nm is incident at an incident angle of 0 °.
(Xii) Spectral transmittance of 0.5% or less, more preferably 0.1% or less at wavelengths of 800 to 950 nm.

The optical filter 1a preferably further exhibits the following optical performance (xiii) when light having a wavelength of 300 nm to 1200 nm is incident at an incident angle of 0 °.
(Xiii) Spectral transmittance of 0.5% or less, more preferably 0.1% or less at a wavelength of 800 to 1000 nm.

Each RGB-compatible color filter used in the image pickup apparatus not only transmits light in the wavelength range corresponding to each RGB, but may also transmit light having a wavelength of 800 nm or more. Therefore, if the spectral transmittance of the infrared cut filter used in the image pickup device in the above wavelength range is not low to some extent, light in the above wavelength range is incident on the pixels of the image sensor, and a signal is output from the pixels. .. When a digital image is acquired using such an image sensor, if the amount of light in the visible light region is sufficiently strong, it can be obtained even if a low amount of infrared rays pass through the color filter and are received by the pixels of the image sensor. There is no significant effect on the digital image. However, when the amount of light in the visible light region is small or in a dark part of an image, it becomes easily affected by such infrared rays, and sometimes a tint such as bluish or reddish may be mixed in those images.

As described above, the color filter used together with the image pickup element such as CMOS and CCD may transmit light in the wavelength range of 800 to 950 nm or 800 to 1000 nm. When the optical filter 1a has the above-mentioned optical performances (xii) and (xiii), such image defects can be prevented.

The UV-IR absorption layer 10 is not particularly limited as long as it absorbs infrared rays and ultraviolet rays so that the optical filter 1a can exhibit the optical performances (i) to (v) above, but for example, phosphonic acid and copper ions can be used. Contains the formed UV-IR absorber.

When the UV-IR absorption layer 10 contains a UV-IR absorber formed by phosphonic acid and copper ions, the phosphonic acid includes, for example, a primary phosphonic acid having an aryl group. In the first phosphonic acid, the aryl group is attached to the phosphorus atom. As a result, the optical filter 1a can easily exhibit the optical performances (i) to (v) described above.

The aryl group contained in the primary phosphonic acid is, for example, a phenyl group, a benzyl group, a toluyl group, a nitrophenyl group, a hydroxyphenyl group, a halogenated phenyl group in which at least one hydrogen atom in the phenyl group is replaced with a halogen atom. Alternatively, it is a halogenated benzyl group in which at least one hydrogen atom in the benzene ring of the benzyl group is substituted with a halogen atom. Desirably, the primary phosphonic acid has a phenyl halide group in part thereof. In this case, the optical filter 1a is more likely to exhibit the above optical performances (i) to (v) more reliably.

When the UV-IR absorption layer 10 contains a UV-IR absorber formed by phosphonic acid and copper ions, the phosphonic acid preferably further contains a second phosphonic acid having an alkyl group. In the second phosphonic acid, the alkyl group is attached to the phosphorus atom.

The alkyl group contained in the second phosphonic acid is, for example, an alkyl group having 6 or less carbon atoms. This alkyl group may have either a straight chain or a branched chain.

When the UV-IR absorption layer 10 contains a UV-IR absorber formed by phosphonic acid and copper ions, the UV-IR absorption layer 10 preferably contains a phosphate ester that disperses the UV-IR absorber. Further includes a matrix resin.

The phosphoric acid ester contained in the UV-IR absorbing layer 10 is not particularly limited as long as the UV-IR absorbing agent can be appropriately dispersed. For example, the phosphoric acid diester represented by the following formula (c1) and the following formula (c1) It contains at least one of the phosphoric acid monoesters represented by c2). In the following formula (c1) and the following formula (c2), R ₂₁ , R ₂₂ , and R ₃ are monovalent functional groups represented by − (CH ₂ CH ₂ O) _n R ₄ , respectively, and n. Is an integer of 1 to 25, and R ₄ represents an alkyl group having 6 to 25 carbon atoms. R ₂₁ , R ₂₂ , and R ₃ are functional groups of the same or different types from each other.

The phosphoric acid ester is not particularly limited, and for example, Prysurf A208N: polyoxyethylene alkyl (C12, C13) ether phosphoric acid ester, Plysurf A208F: polyoxyethylene alkyl (C8) ether phosphoric acid ester, Plysurf A208B: Polyoxyethylene lauryl ether phosphate, Plysurf A219B: Polyoxyethylene lauryl ether phosphate, Plysurf AL: Polyoxyethylene styrenated phenyl ether phosphate, Plysurf A212C: Polyoxyethylene tridecyl ether phosphate , Or Prysurf A215C: polyoxyethylene tridecyl ether phosphate. All of these are products manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. The phosphate ester is NIKKOL DDP-2: polyoxyethylene alkyl ether phosphoric acid ester, NIKKOL DDP-4: polyoxyethylene alkyl ether phosphoric acid ester, or NIKKOL DDP-6: polyoxyethylene alkyl ether phosphoric acid ester. possible. All of these are products manufactured by Nikko Chemicals.

The matrix resin contained in the UV-IR absorbing layer 10 is, for example, a resin capable of dispersing a UV-IR absorber and being heat-curable or ultraviolet-curable. Further, when a 0.1 mm resin layer is formed from the resin as the matrix resin, the transmittance of the resin layer with respect to a wavelength of 350 nm to 900 nm is, for example, 70% or more, preferably 75% or more, which is more desirable. A resin having a value of 80% or more can be used. The content of phosphonic acid is, for example, 3 to 180 parts by mass with respect to 100 parts by mass of the matrix resin.

The matrix resin contained in the UV-IR absorbing layer 10 is not particularly limited as long as the above characteristics are satisfied, but for example, (poly) olefin resin, polyimide resin, polyvinyl butyral resin, polycarbonate resin, polyamide resin, polysulfone resin, polyether. It is a sulfone resin, a polyamideimide resin, a (modified) acrylic resin, an epoxy resin, or a silicone resin. The matrix resin may contain an aryl group such as a phenyl group, and is preferably a silicone resin containing an aryl group such as a phenyl group. If the UV-IR absorbing layer 10 is hard (rigid), cracks are likely to occur due to curing shrinkage during the manufacturing process of the optical filter 1a as the thickness of the UV-IR absorbing layer 10 increases. When the matrix resin is a silicone resin containing an aryl group, the UV-IR absorption layer 10 tends to have good crack resistance. Further, when a silicone resin containing an aryl group is used, the UV-IR absorber is less likely to aggregate when the UV-IR absorber formed by the above phosphonic acid and copper ions is contained. Further, when the matrix resin of the UV-IR absorbing layer 10 is a silicone resin containing an aryl group, the phosphoric acid ester contained in the UV-IR absorbing layer 10 is phosphorus represented by the formula (c1) or the formula (c2). It is desirable to have a linear organic functional group having flexibility such as an oxyalkyl group such as an acid ester. This is because the UV-IR absorber is less likely to aggregate due to the interaction based on the combination of the above phosphonic acid, the silicone resin containing an aryl group, and the phosphoric acid ester having a linear organic functional group such as an oxyalkyl group. Moreover, it is possible to provide good rigidity and good flexibility to the UV-IR absorbing layer. Specific examples of the silicone resin used as the matrix resin include KR-255, KR-300, KR-2621-1, KR-211, KR-311, KR-216, KR-212, and KR-251. be able to. All of these are silicone resins manufactured by Shin-Etsu Chemical Co., Ltd.

As shown in FIG. 1A, the optical filter 1a further includes, for example, a transparent dielectric substrate 20, and at least a part of one main surface of the transparent dielectric substrate 20 is covered with a UV-IR absorbing layer 10. The transparent dielectric substrate 20 is not particularly limited as long as it is a dielectric substrate having a high average transmittance (for example, 80% or more) in 450 nm to 600 nm. In some cases, the transparent dielectric substrate 20 may have an absorbing ability in an ultraviolet region or an infrared region.

The transparent dielectric substrate 20 is made of, for example, glass or resin. When the transparent dielectric substrate 20 is made of glass, the glass contains, for example, borosilicate glass such as D263, soda lime glass (blue plate), white plate glass such as B270, non-alkali glass, or copper. It is an infrared absorbing glass such as a phosphate glass or a borosilicate glass containing copper. When the transparent dielectric substrate 20 is an infrared absorbing glass such as a phosphate glass containing copper or a futh phosphate glass containing copper, the infrared absorbing performance and UV of the transparent dielectric substrate 20 -The infrared absorption performance required for the optical filter 1a can be realized by combining with the infrared absorption performance of the IR absorption layer 10. Therefore, the level of infrared absorption performance required for the UV-IR absorption layer 10 can be lowered. Such infrared absorbing glass is, for example, BG-60, BG-61, BG-62, BG-63, or BG-67 manufactured by Shot Co., Ltd., 500EXL manufactured by Nippon Denki Glass Co., Ltd., or HOYA. CM5000, CM500, C5000, or C500S manufactured by the same company. Further, the infrared absorbing glass may have an ultraviolet absorbing property.

The transparent dielectric substrate 20 may be a transparent crystalline substrate such as magnesium oxide, sapphire, or quartz. For example, sapphire has a high hardness, so it is not easily scratched. Therefore, the plate-shaped sapphire may be arranged in front of a camera module or lens provided in a mobile terminal such as a smartphone or a mobile phone as a scratch-resistant protective material (protect filter). By forming the UV-IR absorbing layer 10 on such a plate-shaped sapphire, it is possible to protect the camera module and the lens and shield ultraviolet rays or infrared rays. This eliminates the need to dispose an optical filter having an ultraviolet ray or infrared ray shielding property around an image sensor such as a CCD or CMOS or inside a camera module. Therefore, if the UV-IR absorption layer 10 is formed on the plate-shaped sapphire, it can contribute to lowering the height of the camera module.

When the transparent dielectric substrate 20 is made of resin, the resin is, for example, (poly) olefin resin, polyimide resin, polyvinyl butyral resin, polycarbonate resin, polyamide resin, polysulfone resin, polyether sulfone resin, polyamideimide resin. , (Modified) acrylic resin, epoxy resin, or silicone resin.

As shown in FIG. 1A, in the optical filter 1a, for example, the UV-IR absorption layer 10 is formed as a single layer. In this case, the structure of the optical filter 1a is simple.

In the optical filter 1a, for example, a composition for forming the UV-IR absorbing layer 10 (UV-IR absorbing composition) is applied to one main surface of the transparent dielectric substrate 20 to form a coating film. It can be produced by drying the coating film. A method for preparing a UV-IR absorbing composition and a method for producing an optical filter 1a will be described by taking as an example a case where the UV-IR absorbing layer 10 contains a UV-IR absorbing agent formed of phosphonic acid and copper ions. ..

First, an example of a method for preparing a UV-IR absorbent composition will be described. A copper salt such as copper acetate monohydrate is added to a predetermined solvent such as tetrahydrofuran (THF) and stirred to obtain a solution of the copper salt. Next, a phosphoric acid ester compound such as a phosphoric acid diester represented by the formula (c1) or a phosphoric acid monoester represented by the formula (c2) is added to the solution of the copper salt and stirred to prepare a solution A. To do. Further, the first phosphonic acid is added to a predetermined solvent such as THF and stirred to prepare solution B. When a plurality of types of phosphonic acids are used as the primary phosphonic acid, the phosphonic acid is added to a predetermined solvent such as THF and then stirred, and a plurality of preliminary solutions prepared for each type of phosphonic acid are mixed and the solution B is used. May be prepared. Desirably, an alkoxysilane monomer is added in the preparation of Liquid B.

When the alkoxysilane monomer is added to the UV-IR absorbent composition, it is possible to prevent the particles of the UV-IR absorbent from aggregating with each other. Therefore, even if the content of the phosphoric acid ester is reduced, the UV-IR absorbent is absorbed. The UV-IR absorber disperses well in the composition. Further, when the optical filter 1a is produced using the UV-IR absorbing composition, a siloxane bond (-Si-O) is formed by treating the optical silane monomer so that the hydrolysis reaction and the polycondensation reaction sufficiently occur. −Si−) is formed, and the optical filter 1a has good moisture resistance. In addition, the optical filter 1a has good heat resistance. This is because the siloxane bond has a higher bond energy than bonds such as -C-C- bond and -C-O- bond, is chemically stable, and is excellent in heat resistance and moisture resistance.

Next, while stirring the solution A, the solution B is added to the solution A and stirred for a predetermined time. Next, a predetermined solvent such as toluene is added to this solution and stirred to obtain a solution C. Next, the solution C is heated and desolvated for a predetermined time to obtain the solution D. As a result, components generated by dissociation of a solvent such as THF and a copper salt such as acetic acid (boiling point: about 118 ° C.) are removed, and a UV-IR absorber is produced by the primary phosphonic acid and copper ions. The temperature at which the liquid C is heated is determined based on the boiling point of the component to be removed dissociated from the copper salt. In the desolvation treatment, C
Solvents such as toluene (boiling point: about 110 ° C.) used to obtain the liquid also volatilize. Since it is desirable that this solvent remains to some extent in the UV-IR absorbent composition, it is preferable that the amount of the solvent added and the time of the desolvent treatment are determined from this viewpoint. In addition, o-xylene (boiling point: about 144 ° C.) can be used instead of toluene to obtain the C solution. In this case, since the boiling point of o-xylene is higher than the boiling point of toluene, the amount of addition can be reduced to about one-fourth of the amount of toluene added.

When the UV-IR absorbing composition further contains a secondary phosphonic acid, the H solution is further prepared, for example, as follows. First, a copper salt such as copper acetate monohydrate is added to a predetermined solvent such as tetrahydrofuran (THF) and stirred to obtain a solution of the copper salt. Next, a phosphoric acid ester compound such as a phosphoric acid diester represented by the formula (c1) or a phosphoric acid monoester represented by the formula (c2) is added to the solution of the copper salt and stirred to prepare a liquid E. To do. Further, the second phosphonic acid is added to a predetermined solvent such as THF and stirred to prepare a liquid F. When multiple types of phosphonic acid are used as the secondary phosphonic acid, the secondary phosphonic acid is added to a predetermined solvent such as THF and then stirred to mix a plurality of preliminary solutions prepared for each type of secondary phosphonic acid. F solution may be prepared. While stirring the E solution, the F solution is added to the E solution and stirred for a predetermined time. Next, a predetermined solvent such as toluene is added to this solution and stirred to obtain a G solution. Next, the solvent removal treatment is performed for a predetermined time while heating the G solution to obtain the H solution. As a result, the components generated by the dissociation of the solvent such as THF and the copper salt such as acetic acid are removed, and another UV-IR absorber is produced by the secondary phosphonic acid and the copper ion. The temperature at which the G solution is heated is determined in the same manner as in the C solution, and the solvent for obtaining the G solution is also determined in the same manner as in the C solution.

A UV-IR absorbent composition can be prepared by adding a matrix resin such as a silicone resin to the liquid D and stirring the mixture. When the UV-IR absorbent composition contains a UV-IR absorber formed by a second phosphonic acid and copper ions, a matrix resin such as a silicone resin is added to the D solution and stirred. A UV-IR absorbing composition can be prepared by further adding solution H to the solution I and stirring the mixture.

The UV-IR absorbent composition is applied to one main surface of the transparent dielectric substrate 20 to form a coating film. For example, a liquid UV-IR absorbent composition is applied to one main surface of the transparent dielectric substrate 20 by spin coating or application with a dispenser to form a coating film. Next, the coating film is subjected to a predetermined heat treatment to cure the coating film. For example, the coating film is exposed to an environment having a temperature of 50 ° C. to 200 ° C. If necessary, the coating film is humidified in order to sufficiently hydrolyze the alkoxysilane monomer contained in the UV-IR absorbent composition. For example, the cured coating film is exposed to an environment having a temperature of 40 ° C. to 100 ° C. and a relative humidity of 40% to 100%. As a result, a repeating structure (Si—O) _{n of} siloxane bond is formed. In this way
The optical filter 1a can be manufactured. Generally, in the hydrolysis and contraction reaction of alkoxysilane containing a monomer, alkoxysilane and water may coexist in the liquid composition to carry out these reactions. However, if water is added to the UV-IR absorbing composition in advance when the optical filter is manufactured, the phosphate ester or UV-IR absorber deteriorates in the process of forming the UV-IR absorbing layer. , UV-IR absorption performance may be reduced and the durability of the optical filter may be impaired. Therefore, it is desirable to perform the humidification treatment after curing the coating film by a predetermined heat treatment.

When the transparent dielectric substrate 20 is a glass substrate, in order to improve the adhesiveness between the transparent dielectric substrate 20 and the UV-IR absorption layer 10, a resin layer containing a silane coupling agent is added to the transparent dielectric substrate 20 and UV. -May be formed between the IR absorption layer 10.

<Modification example>
The optical filter 1a can be changed from various viewpoints. For example, the optical filter 1a
The optical filters 1b to 1f shown in FIGS. 1B to 1F may be changed, respectively. The optical filters 1b to 1f are configured in the same manner as the optical filters 1a, unless otherwise specified. The components of the optical filters 1b to 1f that are the same as or correspond to the components of the optical filter 1a are designated by the same reference numerals, and detailed description thereof will be omitted. The description of the optical filter 1a also applies to the optical filters 1b to 1f unless technically inconsistent.

As shown in FIG. 1B, in the optical filter 1b according to another example of the present invention, the UV-IR absorption layer 10 is formed on both main surfaces of the transparent dielectric substrate 20. As a result, the optical filter 1b can exhibit the above-mentioned optical performances (i) to (v) not by one UV-IR absorbing layer 10 but by two UV-IR absorbing layers 10. The thickness of the UV-IR absorbing layer 10 on both main surfaces of the transparent dielectric substrate 20 may be the same or different. That is, UV on both main surfaces of the transparent dielectric substrate 20 so that the thickness of the UV-IR absorbing layer 10 required for the optical filter 1b to obtain the desired optical properties is evenly or unevenly distributed. -The IR absorption layer 10 is formed. As a result, the thickness of each UV-IR absorbing layer 10 formed on both main surfaces of the transparent dielectric substrate 20 is relatively small. As a result, the internal pressure of the coating film is low and the occurrence of cracks can be prevented. Further, the time for applying the liquid UV-IR absorbing composition can be shortened, and the time for curing the coating film of the UV-IR absorbing composition can be shortened. When the transparent dielectric substrate 20 is thin, when the UV-IR absorbing layer 10 is formed only on one main surface of the transparent dielectric substrate 20, the UV-IR absorbing layer 10 is formed from the UV-IR absorbing composition. The optical filter may warp due to the stress associated with the shrinkage that occurs in. However, since the UV-IR absorption layers 10 are formed on both main surfaces of the transparent dielectric substrate 20, warpage is suppressed in the optical filter 1b even when the transparent dielectric substrate 20 is thin. Also in this case, in order to improve the adhesion between the transparent dielectric substrate 20 and the UV-IR absorbing layer 10, a resin layer containing a silane coupling agent is placed between the transparent dielectric substrate 20 and the UV-IR absorbing layer 10. May be formed in.

As shown in FIG. 1C, the optical filter 1c according to another example of the present invention includes an antireflection film 30. The antireflection film 30 is a film formed so as to form an interface between the optical filter 1c and air to reduce the reflection of light in the visible light region. The antireflection film 30 is a film formed of a dielectric material such as a resin, an oxide, and a fluoride. The antireflection film 30 may be a multilayer film formed by laminating two or more types of dielectrics having different refractive indexes. In particular, the antireflection film 30 may be a dielectric multilayer film composed of a low refractive index material such as SiO ₂ and a high refractive index material such as TiO ₂ or Ta ₂ O ₅ . In this case, Fresnel reflection at the interface between the optical filter 1c and air is reduced, and the amount of light in the visible light region of the optical filter 1c can be increased. Also in this case, in order to improve the adhesion between the transparent dielectric substrate 20 and the UV-IR absorbing layer 10, a resin layer containing a silane coupling agent is placed between the transparent dielectric substrate 20 and the UV-IR absorbing layer 10. May be formed in. In some cases, in order to improve the adhesiveness of the antireflection film 30, a resin layer containing a silane coupling agent may be formed between the UV-IR absorption layer 10 and the antireflection film 30. The antireflection film 30 may be arranged on both main surfaces of the optical filter 1c, or may be arranged only on one main surface.

As shown in FIG. 1D, the optical filter 1d according to another example of the present invention is composed of only the UV-IR absorption layer 10. The optical filter 1d is formed by applying a UV-IR absorbing composition to a predetermined substrate such as a glass substrate, a resin substrate, a metal substrate (for example, a steel substrate or a stainless steel substrate) to form a coating film, and the coating film is formed. Can be manufactured by peeling from the substrate after curing. The optical filter 1d may be manufactured by a melt molding method. The optical filter 1d is thin because it does not include the transparent dielectric substrate 20. Therefore, the optical filter 1d can contribute to lowering the profile of the image sensor and the optical system.

As shown in FIG. 1E, the optical filter 1e according to another example of the present invention is the UV-IR absorption layer 1.
0 and a pair of antireflection films 30 arranged on both sides thereof are provided. In this case, the optical filter 1e can contribute to lowering the height of the image sensor and the optical system, and can increase the amount of light in the visible light region as compared with the optical filter 1d.

As shown in FIG. 1F, the optical filter 1f according to another example of the present invention comprises a UV-IR absorbing layer 10 and a reflective film 40 that reflects infrared rays and / or ultraviolet rays arranged on one of the main surfaces thereof. I have. The reflective film 40 is, for example, a film formed by depositing a metal such as aluminum, or a dielectric multilayer film in which layers made of a high refractive index material and layers made of a low refractive index material are alternately laminated. is there. As the high refractive index material, a material having a refractive index of 1.7 to 2.5 such as TiO ₂ , ZrO ₂ , Ta ₂ O ₅ , Nb ₂ O ₅ , ZnO, and In ₂ O ₃ is used. As the low refractive index material, a material having a refractive index of 1.2 to 1.6 such as SiO ₂ , Al ₂ O ₃ , and Mg F ₂ is used. The method for forming the dielectric multilayer film is, for example, a chemical vapor deposition (CVD) method, a sputtering method, or a vacuum vapor deposition method. Further, such a reflective film may be formed so as to form both main surfaces of the optical filter (not shown). When the reflective film is formed on both main surfaces of the optical filter, the stress is balanced on both the front and back surfaces of the optical filter, and there is an advantage that the optical filter is less likely to warp.

The optical filters 1a to 1f may be modified to include an infrared absorbing film (not shown) separately from the UV-IR absorbing layer 10, if necessary. The infrared absorbing film contains, for example, an organic infrared absorber such as cyanine-based, phthalocyanine-based, squarylium-based, diimmonium-based, and azo-based infrared absorbers or an infrared absorber composed of a metal complex. The infrared absorber film contains, for example, one or more infrared absorbers selected from these infrared absorbers. This organic infrared absorber has a small wavelength range (absorption band) of light that can be absorbed, and is suitable for absorbing light having a wavelength in a specific range.

Each of the optical filters 1a to 1f may be modified to include an ultraviolet absorbing film (not shown) in addition to the UV-IR absorbing layer 10, if necessary. The UV absorbing film contains, for example, a benzophenone-based, triazine-based, indole-based, merocyanine-based, and oxazole-based UV absorber. The UV absorbing film contains, for example, one or more UV absorbers selected from these UV absorbers. These ultraviolet absorbers may include those that absorb ultraviolet rays in the vicinity of, for example, 300 nm to 340 nm, emit light (fluorescence) having a wavelength longer than the absorbed wavelength, and function as a fluorescent agent or a fluorescent whitening agent. The ultraviolet absorbing film can reduce the incident of ultraviolet rays that cause deterioration of the material used for the optical filter such as resin.

The above-mentioned infrared absorber or ultraviolet absorber may be contained in the transparent dielectric substrate 20 made of resin in advance. The infrared absorbing film or the ultraviolet absorbing film can be formed, for example, by forming a film containing an infrared absorbing agent or an ultraviolet absorbing agent. In this case, the resin needs to be able to appropriately dissolve or disperse the infrared absorber or the ultraviolet absorber, and to be transparent. Such resins include (poly) olefin resin, polyimide resin, polyvinyl butyral resin, polycarbonate resin, polyamide resin, polysulfone resin, polyether sulfone resin, polyamideimide resin, (modified) acrylic resin, epoxy resin, and silicone resin. Can be exemplified.

The optical filters 1a to 1f may be modified to further include a reflective film that reflects infrared rays and / or ultraviolet rays, if necessary. As such a reflective film, for example, a film formed by depositing a metal such as aluminum, or a dielectric in which layers made of a high refractive index material and layers made of a low refractive index material are alternately laminated. A multilayer film can be used. Such a reflective film may be formed so as to form both main surfaces of the optical filter, or may be formed so as to form one main surface of the optical filter. When the reflective film is formed as in the former case, the stress is balanced on both the front and back sides of the optical filter, and the optical filter is less likely to warp. When the reflective film is a dielectric multilayer film, for example, 1.7 to _2. High refractive index materials such as TiO ₂ , ZrO ₂ , Ta ₂ O ₅ , Nb ₂ O ₅ , ZnO, and In ₂ O ₃ . A material having a refractive index of 5 is used, and as a low refractive index material, a material having a refractive index of 1.2 to 1.6 such as SiO ₂ , Al ₂ O ₃ , and Mg F ₂ is used. The method for forming the dielectric multilayer film is, for example, a chemical vapor phase growth (CVD) method, a sputtering method, or a vacuum vapor deposition method.

The optical filters 1a to 1f are arranged on the front surface (closer to the subject) of the image pickup device such as CCD or CMOS inside the image pickup device, for example, in order to bring the spectral sensitivity of the image pickup device in the image pickup device closer to the human visual sensitivity. To.

Further, as shown in FIG. 2, for example, a camera module 100 using an optical filter 1a can be provided. In addition to the optical filter 1a, the camera module 100 includes, for example, a lens system 2, a low-pass filter 3, an image pickup element 4, a circuit board 5, an optical filter support housing 7, and an optical system housing 8. The peripheral edge of the optical filter 1a is fitted, for example, in an annular recess in contact with an opening formed in the center of the optical filter support housing 7. The optical filter support housing 7 is fixed to the optical system housing 8. Inside the optical system housing 8, the lens system 2, the low-pass filter 3, and the image sensor 4 are arranged in this order along the optical axis. The image sensor 4 is, for example, CCD or CMOS. The light from the subject is collected by the lens system 2 after the ultraviolet rays and infrared rays are cut by the optical filter 1a, and further passes through the low-pass filter 3 and enters the image sensor 4. The electric signal generated by the image sensor 4 is sent to the outside of the camera module 100 by the circuit board 5.

In the camera module 100, the optical filter 1a also functions as a cover (protection filter) for protecting the lens system 2. In this case, preferably, a sapphire substrate is used as the transparent dielectric substrate 20 in the optical filter 1a. Since the sapphire substrate has high scratch resistance, it is desirable that the sapphire substrate is arranged on the outside (the side opposite to the side of the image sensor 4), for example. As a result, the optical filter 1a has high scratch resistance against contact from the outside and the like, and at the same time, the optical performances (i) to (v) (preferably, the optical performances of (vi) to (xiii)) are improved. Have. As a result, it is not necessary to arrange an optical filter for cutting infrared rays or ultraviolet rays near the image sensor 4, and the camera module 100 can be easily lowered. The camera module 100 shown in FIG. 2 is a schematic view for exemplifying the arrangement and the like of each component, and describes an embodiment in which the optical filter 1a is used as a protect filter. As long as the optical filter 1a functions as a protect filter, the camera module using the optical filter 1a is not limited to the one shown in FIG. 2, and the low-pass filter 3 may be omitted if necessary. Other filters may be provided.

The present invention will be described in more detail by way of examples. The present invention is not limited to the following examples. First, an evaluation method of an optical filter according to an example and a comparative example will be described.

<Measurement of transmittance spectrum of optical filter>
The transmittance spectrum when light having a wavelength of 300 nm to 1200 nm was incident on the optical filters according to Examples and Comparative Examples was measured using an ultraviolet visible spectrophotometer (manufactured by JASCO Corporation, product name: V-670). .. The angle of incidence of the incident light on the optical filter was changed from 0 ° to 65 ° in 5 ° increments, and the transmittance spectrum at each angle was measured.

<Measurement of UV-IR absorption layer thickness>
The thickness of the optical filter according to the examples and the comparative examples was measured with a digital micrometer. Among the optical filters according to Examples and Comparative Examples, for an optical filter having a transparent dielectric substrate such as glass, the thickness of the glass substrate is subtracted from the thickness of the optical filter measured by a digital micrometer to absorb UV-IR in the optical filter. The thickness of the layer was determined.

<Example 1>
1.125 g of copper acetate monohydrate ((CH ₃ COO) ₂ Cu · H ₂ O) and 60 g of tetrahydrofuran (THF) were mixed and stirred for 3 hours to obtain a copper acetate solution. Next, 0.412 g of Prysurf A208N (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), which is a phosphoric acid ester compound, was added to the obtained cupric acetate solution and stirred for 30 minutes to obtain a solution A. Add 10 g of THF to 0.441 g of phenylphosphonic acid (C ₆ H ₅ PO (OH) ₂ ) (manufactured by Nissan Chemical Industries, Ltd.), stir for 30 minutes, and stir B-
One liquid was obtained. To 0.661 g of 4-bromophenylphosphonic acid (C ₆ H ₄ BrPO (OH) ₂ ) (manufactured by Tokyo Kasei Kogyo Co., Ltd.), 10 g of THF was added and stirred for 30 minutes to obtain a B-2 solution. Next, the B-1 solution and the B-2 solution were mixed and stirred for 1 minute to obtain 1.934 g of methyltriethoxysilane (METES: CH ₃ Si (OC ₂ H ₅ ) ₃ ) (manufactured by Shin-Etsu Chemical Co., Ltd.). Add 0.634 g of tetraethoxysilane (TEOS: Si (OC ₂ H ₅ ) ₄ ) (special grade manufactured by Kishida Chemical Co., Ltd.) and add 1 more.
The mixture was stirred for 1 minute to obtain solution B. Solution B was added to solution A while stirring solution A, and the mixture was stirred at room temperature for 1 minute. Next, 25 g of toluene was added to this solution, and the mixture was stirred at room temperature for 1 minute to obtain Solution C. This liquid C is placed in a flask and heated in an oil bath (manufactured by Tokyo Rika Kikai Co., Ltd., model: OSB-2100) while being desolvated by a rotary evaporator (manufactured by Tokyo Rika Kikai Co., Ltd., model: N-1110SF). went. The set temperature of the oil bath was adjusted to 105 ° C. Then, the desolvent-treated liquid D was taken out from the flask. Liquid D, which is a dispersion of fine particles of phenyl-based copper phosphonate (absorbent) containing copper phenylphosphonate and copper 4-bromophenylphosphonate, was transparent, and the fine particles were well dispersed.

0.225 g of copper acetate monohydrate and 36 g of THF were mixed and stirred for 3 hours to obtain a copper acetate solution. Next, 0.129 g of Plysurf A208N, which is a phosphoric acid ester compound, was added to the obtained cupric acetate solution and stirred for 30 minutes to obtain a solution E. Also, n-butylphosphonic acid (C ₄₎
H ₉ PO (OH) ₂ ) (manufactured by Nippon Kagaku Kogyo Co., Ltd.) 0.144 g was added with 10 g of THF and stirred for 30 minutes to obtain a liquid F. Solution F was added to solution E while stirring solution E, and the mixture was stirred at room temperature for 1 minute. Next, 25 g of toluene was added to this solution, and the mixture was stirred at room temperature for 1 minute to obtain a G solution. This G solution was placed in a flask and heated in an oil bath while being desolvated by a rotary evaporator. The set temperature of the oil bath was adjusted to 105 ° C. Then, the desolvent-treated H solution was taken out from the flask. Liquid H, which is a dispersion of fine particles of copper butylphosphonate, was transparent, and the fine particles were well dispersed.

2.200 g of silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-300) was added to solution D and stirred for 30 minutes to obtain solution I. Solution H was added to solution I and stirred for 30 minutes to obtain the UV-IR absorbent composition (solution J) according to Example 1. Regarding the UV-IR absorbent composition (Liquid J) according to Example 1, the mass-based content of each component is shown in Table 1, and the content of each component based on the substance amount and the content of each phosphonic acid based on the substance amount are shown in Table 1. The content rate is shown in Table 2. Since the content of each phosphonic acid is obtained by rounding off the second decimal place, the total may not be 100 mol%.

Conducted using a dispenser in a range of 30 mm x 30 mm at the center of one main surface of a transparent glass substrate (manufactured by SCHOTT, product name: D263) made of borosilicate glass having a size of 76 mm x 76 mm x 0.21 mm. The UV-IR absorbing composition according to Example 1 was applied to form a coating film. The thickness of the coating film was determined by trial and error so that the average transmittance of the optical filter at a wavelength of 700 to 730 nm was about 1%. A frame having an opening corresponding to the coating range of the coating liquid was placed on the transparent glass substrate to dam the coating liquid so that the coating liquid would not flow out when the UV-IR absorbent composition was applied to the transparent glass substrate. .. By adjusting the amount of the coating liquid, a coating film having a target thickness was obtained. Next, a transparent glass substrate having an undried coating film was placed in an oven and heat-treated at 85 ° C. for 6 hours to cure the coating film. After that, a transparent glass substrate on which the above coating film was formed was placed in a constant temperature and humidity chamber set at a temperature of 85 ° C. and a relative humidity of 85% for 20 hours to perform a humidification treatment, and UV-IR was performed on the transparent glass substrate. An optical filter according to Example 1 in which an absorption layer was formed was obtained. The humidification treatment promotes the hydrolysis and contraction polymerization of the alkoxysilane contained in the UV-IR absorbing composition coated on the transparent glass substrate, and forms a hard and dense matrix in the UV-IR absorbing layer. went. The thickness of the UV-IR absorption layer of the optical filter according to Example 1 was 170 μm. The transmission spectrum of the optical filter according to Example 1 was measured at an incident angle of 0 ° to 65 °. The transmittance spectra at incident angles of 0 °, 40 °, 50 °, and 60 ° are shown in FIG. Tables 7 and 8 show the results of the optical filter according to Example 1 taken from the transmittance spectrum when the incident angle is 0 °. The “wavelength range with a transmittance of 78% or more” in Table 8 is a wavelength range showing a spectral transmission rate of 78% or more at a wavelength of 400 nm to 600 nm. The “wavelength range with a transmittance of 1% or less” regarding the infrared region characteristics in Table 8 is a wavelength range showing a spectral transmittance of 1% or less at a wavelength of 700 nm to 1200 nm. The “wavelength range with a transmittance of 0.1% or less” regarding the infrared region characteristics in Table 8 is a wavelength range showing a spectral transmittance of 0.1% or less at a wavelength of 700 nm to 1200 nm. The “wavelength range with a transmittance of 1% or less” regarding the ultraviolet region characteristics in Table 8 is a wavelength range showing a spectral transmittance of 1% or less at a wavelength of 300 nm to 400 nm. The “wavelength range with a transmittance of 0.1% or less” regarding the ultraviolet region characteristics in Table 8 is a wavelength range showing a spectral transmittance of 0.1% or less at a wavelength of 300 nm to 400 nm. This also applies to Table 10, Table 12, Table 14, Table 16, Table 18, and Table 20. Further, Table 11 and Table 11 show the results (incident angle: 0 ° to 65 °) of the optical filter according to Example 1 taken from the transmittance spectrum when the incident angle is 0 ° and 30 ° to 65 ° (in 5 ° increments). It is shown in Table 12.

<Examples 2 to 15>
The UV-IR absorbing compositions according to Examples 2 to 15 were prepared in the same manner as in Example 1 except that the amount of each compound added was adjusted as shown in Table 1. The thickness of the UV-IR absorbing layer was adjusted as shown in Table 1 by using the UV-IR absorbing composition according to Examples 2 to 15 instead of the UV-IR absorbing composition according to Example 1. The optical filters according to Examples 2 to 15 were produced in the same manner as in Example 1 except for the above. Table 2 shows the content and content of each phosphonic acid based on the amount of substance. Since the content of each phosphonic acid is obtained by rounding off the second fraction, the total may not be 100 mol%. The transmittance spectrum of the optical filter according to Example 2 at an incident angle of 0 ° to 65 ° was measured. The transmission spectra at the incident angles of 0 °, 40 °, 50 ° and 60 ° are shown in FIG. Tables 7 and 8 show the results of the optical filter according to the second embodiment, which were taken from the transmission spectrum when the incident angle was 0 °. Further, Tables 13 and 14 show the results of the optical filter according to Example 2 taken from the transmittance spectra at an incident angle of 0 ° and 30 ° to 65 ° (in 5 ° increments). Tables 7 and 8 show the results of the optical filters according to Examples 3 to 15 taken from the transmittance spectrum when the incident angle is 0 °.

<Example 16>
Conducted using a dispenser in a range of 30 mm x 30 mm at the center of one main surface of a transparent glass substrate (manufactured by SCHOTT, product name: D263) made of borosilicate glass having dimensions of 76 mm x 76 mm x 0.21 mm. The UV-IR absorbent composition according to Example 2 was applied to form a coating film having a predetermined thickness. A frame having an opening corresponding to the coating range of the coating liquid was placed on the transparent glass substrate to dam the coating liquid so that the coating liquid would not flow out when the UV-IR absorbent composition was applied to the transparent glass substrate. .. Next, a transparent glass substrate having an undried coating film was placed in an oven and heat-treated at 85 ° C. for 6 hours to cure the coating film. Then, this coating film was peeled off from the transparent glass substrate. The optics according to Example 16 composed of only the UV-IR absorption layer was subjected to a humidification treatment by placing the peeled coating film in a constant temperature and humidity chamber set at a temperature of 85 ° C. and a relative humidity of 85% for 20 hours. I got a filter. In the measurement with a digital micrometer, the thickness of only the light absorbing layer was measured. As a result, the thickness of the optical filter according to Example 16 was 132 μm. The transmittance spectrum of the optical filter according to Example 16 at an incident angle of 0 ° to 65 ° was measured. The transmission spectra at the incident angles of 0 °, 40 °, 50 °, and 60 ° are shown in FIG. Tables 7 and 8 show the results of the optical filter according to Example 16 taken from the transmittance spectrum when the incident angle is 0 °. Further, Tables 15 and 16 show the results of the optical filter according to Example 16 taken from the transmission spectrum at an incident angle of 0 ° and 30 ° to 65 ° (in 5 ° increments).

<Example 17>
Conducted using a dispenser in a range of 30 mm x 30 mm at the center of one main surface of a transparent glass substrate (manufactured by SCHOTT, product name: D263) made of borosilicate glass having dimensions of 76 mm x 76 mm x 0.21 mm. The UV-IR absorbent composition according to Example 2 was applied to form a coating film having a thickness of about half the thickness of the coating film in Example 2. A frame having an opening corresponding to the coating range of the coating liquid was placed on the transparent glass substrate to dam the coating liquid so that the coating liquid would not flow out when the UV-IR absorbent composition was applied to the transparent glass substrate. .. Next, a transparent glass substrate having an undried coating film was placed in an oven and heat-treated at 85 ° C. for 6 hours to cure the coating film. Next, the UV-IR absorbent composition according to Example 2 was applied to an area of 30 mm × 30 mm at the center of the other main surface of the transparent glass substrate using a dispenser to determine the thickness of the coating film in Example 2. A coating film having a thickness of about half was formed. A frame having an opening corresponding to the coating range of the coating liquid was placed on the transparent glass substrate to dam the coating liquid so that the coating liquid would not flow out when the UV-IR absorbent composition was applied to the transparent glass substrate. .. Next, a transparent glass substrate having an undried coating film was placed in an oven and heat-treated at 85 ° C. for 6 hours to cure the coating film. Next, a transparent glass substrate having the above coating film formed on both main surfaces was placed in a constant temperature and humidity chamber set at a temperature of 85 ° C. and a relative humidity of 85% for 20 hours to perform humidification treatment, and the transparent glass substrate was subjected to humidification treatment. An optical filter according to Example 17 in which UV-IR absorbing layers were formed on both sides of the glass was obtained. The total thickness of the UV-IR absorbing layers formed on both sides of the transparent glass substrate was 193 μm. The transmission spectrum of the optical filter according to Example 17 at an incident angle of 0 ° to 65 ° was measured. The transmittance spectra at the incident angles of 0 °, 40 °, 50 ° and 60 ° are shown in FIG. Tables 7 and 8 show the results of the optical filter according to Example 17 taken from the transmittance spectrum when the incident angle is 0 °. Tables 17 and 18 show the results of the optical filter according to Example 17 taken from the transmittance spectra at an incident angle of 0 ° and 30 ° to 65 ° (in 5 ° increments).

<Example 18>
In the same manner as in Example 17, a transparent glass substrate of the same type as the transparent glass substrate used in Example 17 having a thickness of 0.07 mm was used instead of the transparent glass substrate used in Example 17. An optical filter according to Example 18 in which UV-IR absorbing layers were formed on both sides of a transparent glass substrate was produced. The total thickness of the UV-IR absorbing layers formed on both sides of the transparent glass substrate was 183 μm. The transmittance spectrum of the optical filter according to Example 18 at an incident angle of 0 ° to 65 ° was measured. The transmittance spectra at the incident angles of 0 °, 40 °, 50 ° and 60 ° are shown in FIG. Tables 7 and 8 show the results of the optical filter according to Example 18 as seen from the transmission spectrum when the incident angle is 0 °. Tables 19 and 20 show the results of the optical filter according to Example 18 taken from the transmittance spectra at an incident angle of 0 ° and 30 ° to 65 ° (in 5 ° increments).

<Example 19>
As the phosphoric acid ester compound, Plysurf A208F (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was used instead of Plysurf A208N, and the addition amount of each compound was adjusted as shown in Table 1 in the same manner as in Example 1. The UV-IR absorbing composition according to Example 19 was prepared. Example 1 and Example 1 except that the UV-IR absorbing composition according to Example 19 was used instead of the UV-IR absorbing composition according to Example 1 and the thickness of the UV-IR absorbing layer was adjusted to 198 μm. Similarly, the optical filter according to Example 19 was produced. Tables 7 and 8 show the results obtained by measuring the transmission spectrum of the optical filter according to Example 19 and observing the transmission spectrum when the incident angle is 0 °.

<Example 20>
Instead of 4-bromophenyl phosphonic acid, 4-fluorophenyl acid _{(C 6 H 4 FPO (OH} ) 2) (manufactured by Tokyo Kasei Kogyo Co., Ltd.), the amount of each compound was adjusted as shown in Table 1 A UV-IR absorbing composition according to Example 20 was prepared in the same manner as in Example 1 except for the above. Example 1 and Example 1 except that the UV-IR absorbing composition according to Example 20 was used instead of the UV-IR absorbing composition according to Example 1 and the thickness of the UV-IR absorbing layer was adjusted to 168 μm. Similarly, the optical filter according to Example 20 was produced. Tables 7 and 8 show the results obtained by measuring the transmittance spectrum of the optical filter according to Example 20 and observing from the transmittance spectrum when the incident angle is 0 °.

<Example 21>
Example 21 was the same as in Example 2 except that an infrared absorbing glass substrate having a thickness of 100 μm was used instead of the transparent glass substrate used in Example 2 and the thickness of the UV-IR absorbing layer was adjusted to 76 μm. The optical filter according to the above was produced. This infrared absorbing glass substrate contained copper and had the transmittance spectrum shown in FIG. 8A. The transmission spectrum of the optical filter according to Example 21 at an incident angle of 0 ° was measured. The result is shown in FIG. 8B. Tables 7 and 8 show the results of the optical filter according to Example 21 as seen from the transmission spectrum at an incident angle of 0 °.

<Examples 22 to 37>
Example 22 in the same manner as in Example 2 except that the conditions for the humidification treatment of the dried coating film were changed as shown in Table 3 and the thickness of the UV-IR absorbing layer was adjusted as shown in Table 3. Optical filters according to ~ 37 were produced. The transmittance spectrum of the optical filter according to Examples 22 to 24 at an incident angle of 0 ° was measured. The results are shown in FIGS. 9 to 11, respectively. Tables 7 and 8 show the results of the optical filters according to Examples 22 to 24, which were taken from the transmission spectrum when the incident angle was 0 °. Tables 7 and 8 show the results obtained by measuring the transmittance spectra of the optical filters according to Examples 25 to 37 and recognizing them from the transmittance spectra when the incident angle is 0 °.

<Example 38>
Example 38 in the same manner as in Example 2 except that a sapphire substrate having a thickness of 0.3 mm was used instead of the transparent glass substrate used in Example 2 and the thickness of the UV-IR absorption layer was adjusted to 168 μm. The optical filter according to the above was produced. The transmittance spectrum of the optical filter according to Example 38 at an incident angle of 0 ° was measured. The result is shown in FIG. Tables 7 and 8 show the results of the optical filter according to Example 38 taken from the transmittance spectrum when the incident angle is 0 °.

<Comparative example 1>
Liquid D (dispersion of fine particles of phenylphosphonate) according to Comparative Example 1 was prepared in the same manner as in Example 1 except that the amount of each compound added was adjusted as shown in Tables 4 and 5. .. 2.200 g of silicone resin (manufactured by Shinetsu Chemical Industry Co., Ltd., product name: KR-300) was added to the D solution according to Comparative Example 1 and stirred for 30 minutes to obtain a UV-IR absorbent composition according to Comparative Example 1. It was. Example 1 except that the thickness of the UV-IR absorbing layer was adjusted to 126 μm by using the UV-IR absorbing composition according to Comparative Example 1 instead of the UV-IR absorbing composition according to Example 1. The optical filter according to Comparative Example 1 was produced in the same manner as in the above. Tables 9 and 10 show the results obtained by measuring the transmittance spectrum of the optical filter according to Comparative Example 1 and recognizing it from the transmittance spectrum when the incident angle is 0 °. Further, the thickness of the UV-IR absorption layer of the optical filter according to Comparative Example 1 was changed to 200 μm based on the result of the transmittance spectrum measurement when the incident angle was 0 ° of the optical filter according to Comparative Example 1. The transmittance spectrum of the case is calculated, and the results that can be seen from the transmittance spectrum are shown in Tables 9 and 10 as Comparative Calculation Example 1.

<Comparative example 2>
Liquid D (dispersion of fine particles of phenylphosphonate) according to Comparative Example 2 was prepared in the same manner as in Example 1 except that the amount of each compound added was adjusted as shown in Tables 4 and 5. did. 4.400 g of a silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-300) was added to the D solution according to Comparative Example 2 and stirred for 30 minutes to obtain a UV-IR absorbent composition according to Comparative Example 2. It was. Using the UV-IR absorbing composition according to Comparative Example 2 instead of the UV-IR absorbing composition according to Example 1, the thickness of the UV-IR absorbing layer is adjusted to 217 μm, and the coating film is cured. An optical filter according to Comparative Example 2 was produced in the same manner as in Example 1 except that the conditions for the heat treatment and the humidification treatment were changed as shown in Table 6. Tables 9 and 10 show the results that can be seen from the transmission spectrum when the incident angle is 0 ° by measuring the transmission spectrum of the optical filter according to Comparative Example 2. Further, the thickness of the UV-IR absorption layer of the optical filter according to Comparative Example 2 was changed to 347 μm based on the result of the transmission spectrum measurement when the incident angle was 0 ° of the optical filter according to Comparative Example 2. The transmission spectrum of the case is calculated, and the results that can be seen from the transmission spectrum are shown in Tables 9 and 10 as Comparative Calculation Example 2.

<Comparative example 3>
1.125 g of copper acetate monohydrate and 60 g of THF were mixed and stirred for 3 hours to obtain a copper acetate solution. Next, 0.624 g of Prysurf A208F (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) was added to the obtained copper acetate solution and stirred for 30 minutes to obtain a solution A. 10 g of THF was added to 0.832 g of phenylphosphonic acid (manufactured by Nissan Chemical Industries, Ltd.) and stirred for 30 minutes to obtain a B-1 solution. 1.274 g of MTES (manufactured by Shin-Etsu Chemical Co., Ltd.) and 1.012 g of TEOS (special grade manufactured by Kishida Chemical Co., Ltd.) were added to the B-1 solution and stirred for another 1 minute to obtain the B solution. Solution B was added to solution A while stirring solution A, and the mixture was stirred at room temperature for 1 minute. Next, 25 g of toluene was added to this solution, and the mixture was stirred at room temperature for 1 minute to obtain Solution C. This liquid C is placed in a flask and heated with an oil bath (manufactured by Tokyo Rika Kikai Co., Ltd., model: OSB-2100) while being desolvated by a rotary evaporator (manufactured by Tokyo Rika Kikai Co., Ltd., model: N-1110SF). went. The set temperature of the oil bath was adjusted to 105 ° C. Then, the liquid D according to Comparative Example 3 after the desolvation treatment was taken out from the flask. The liquid D (dispersion of fine particles of copper phenylphosphonate) according to Comparative Example 3 was transparent, and the fine particles were well dispersed.

4.400 g of a silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-300) was added to the D solution according to Comparative Example 3 and stirred for 30 minutes to obtain a UV-IR absorbent composition according to Comparative Example 3. It was. Using the UV-IR absorbing composition according to Comparative Example 3 instead of the UV-IR absorbing composition according to Example 1, the thickness of the UV-IR absorbing layer is adjusted to 198 μm, and the coating film is cured. An optical filter according to Comparative Example 3 was produced in the same manner as in Example 1 except that the conditions for the heat treatment for the purpose were adjusted as shown in Table 6. Tables 9 and 10 show the results obtained by measuring the transmittance spectrum of the optical filter according to Comparative Example 3 and observing the transmittance spectrum when the incident angle is 0 °. Further, based on the result of the transmittance spectrum measurement of the optical filter according to Comparative Example 3, the transmittance spectrum when the thickness of the UV-IR absorption layer of the optical filter according to Comparative Example 3 was changed to 303 μm was calculated. The results that can be seen from this transmittance spectrum are shown in Tables 9 and 10 as Comparative Calculation Example 3.

<Comparative example 4>
1.125 g of copper acetate monohydrate and 60 g of THF were mixed and stirred for 3 hours to obtain a copper acetate solution. Next, 0.891 g of Prysurf A208F, which is a phosphoric acid ester compound, was added to the obtained copper acetate solution and stirred for 30 minutes to obtain a liquid E. Further, 10 g of THF was added to 0.670 g of n-butylphosphonic acid (manufactured by Nippon Chemical Industrial Co., Ltd.) and stirred for 30 minutes to obtain a liquid F. Solution F was added to solution E while stirring solution E, and the mixture was stirred at room temperature for 1 minute. Next, 25 g of toluene was added to this solution, and the mixture was stirred at room temperature for 1 minute to obtain a G solution. This G solution was placed in a flask and heated in an oil bath while being desolvated by a rotary evaporator. The set temperature of the oil bath was adjusted to 105 ° C. Then, the liquid H according to Comparative Example 4 after the desolvation treatment was taken out from the flask. Liquid H, which is a dispersion of fine particles of copper butylphosphonate, was transparent, and the fine particles were well dispersed.

4.400 g of silicone resin (manufactured by Shinetsu Chemical Industry Co., Ltd., product name: KR-300) was added to the H solution according to Comparative Example 4 and stirred for 30 minutes to obtain a UV-IR absorbent composition according to Comparative Example 4. It was. Using the UV-IR absorbing composition according to Comparative Example 4 instead of the UV-IR absorbing composition according to Comparative Example 2, the thickness of the UV-IR absorbing layer was adjusted to 1002 μm, and the coating film was humidified. The optical filter according to Comparative Example 4 was produced in the same manner as in Comparative Example 2 except that the above was not performed. Tables 9 and 10 show the results obtained by measuring the transmittance spectrum of the optical filter according to Comparative Example 4 and recognizing it from the transmittance spectrum when the incident angle is 0 °. Further, the thickness of the UV-IR absorption layer of the optical filter according to Comparative Example 4 was changed to 1216 μm and 385 μm based on the result of the transmittance spectrum measurement when the incident angle was 0 ° of the optical filter according to Comparative Example 4. The transmittance spectra are calculated respectively, and the results that can be seen from these transmittance spectra are shown in Tables 9 and 10 as Comparative Calculation Example 4-A and Comparative Calculation Example 4-B, respectively.

<Comparative example 5>
The optical filter according to Comparative Example 5 was produced in the same manner as in Example 2 except that the thickness of the UV-IR absorbing layer was adjusted to 191 μm and the coating film was not humidified. Tables 9 and 10 show the results that can be seen from the transmission spectrum when the incident angle is 0 ° by measuring the transmission spectrum of the optical filter according to Comparative Example 5. When the thickness of the UV-IR absorption layer of the optical filter according to Comparative Example 5 is changed to 148 μm based on the result of the transmittance spectrum measurement of the optical filter according to Comparative Example 5 when the incident angle is 0 °. The transmittance spectrum is calculated, and the results that can be seen from the transmittance spectrum are shown in Tables 9 and 10 as Comparative Calculation Example 5.

<Comparative Examples 6 and 7>
The optical filters according to Comparative Examples 6 and 7 were used in the same manner as in Example 2 except that the thickness of the UV-IR absorbing layer was adjusted as shown in Table 9 and the humidification treatment of the coating film was adjusted as shown in Table 6. Made. Tables 9 and 10 show the results obtained by measuring the transmittance spectra of the optical filters according to Comparative Examples 6 and 7 and observing them from the transmittance spectra when the incident angle is 0 °. When the thickness of the UV-IR absorption layer of the optical filter according to Comparative Example 6 is changed to 155 μm based on the result of the transmittance spectrum measurement of the optical filter according to Comparative Example 6 when the incident angle is 0 °. The transmittance spectrum is calculated, and the results that can be seen from the transmittance spectrum are shown in Tables 9 and 10 as Comparative Calculation Example 6. Further, the thickness of the UV-IR absorption layer of the optical filter according to Comparative Example 7 was changed to 161 μm based on the result of the transmission spectrum measurement when the incident angle was 0 ° of the optical filter according to Comparative Example 7. The transmission spectrum of the case is calculated, and the results that can be seen from the transmission spectrum are shown in Tables 9 and 10 as Comparative Calculation Example 7.

<Comparative Example 8>
In the same manner as in Comparative Example 1, the solution D (dispersion of fine particles of phenyl phosphonate) according to Comparative Example 8 was prepared. 0.225 g of copper acetate monohydrate and 36 g of THF were mixed and stirred for 3 hours to obtain a copper acetate solution. Next, 0.178 g of Prysurf A208F (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), which is a phosphate ester compound, was added to the obtained copper acetate solution and stirred for 30 minutes to obtain a solution E. Further, 10 g of THF was added to 0.134 g of n-butylphosphonic acid (manufactured by Nippon Chemical Industrial Co., Ltd.) and stirred for 30 minutes to obtain a liquid F. Solution F was added to solution E while stirring solution E, and the mixture was stirred at room temperature for 1 minute. Next, 25 g of toluene was added to this solution, and the mixture was stirred at room temperature for 1 minute to obtain a G solution. This G solution was placed in a flask and heated in an oil bath while being desolvated by a rotary evaporator. The set temperature of the oil bath was adjusted to 105 ° C. Then, the liquid H according to Comparative Example 8 after the desolving treatment was taken out from the flask. 2.200 g of a silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-300) was added to the D solution according to Comparative Example 8 and stirred for 30 minutes to obtain the I solution according to Comparative Example 8. The solution H according to Comparative Example 8 was added to the solution I according to Comparative Example 8 and stirred, but agglomeration of copper phosphonate particles occurred, and a highly transparent UV-IR absorbing composition could not be obtained. ..

<Comparative Example 9>
An attempt was made to prepare a UV-IR absorbent composition containing only n-butylphosphonic acid as the phosphonic acid and not containing the alkoxysilane monomer in the amount shown in Table 4, but the copper phosphonate particles agglomerated, which was high. It was not possible to obtain a transparent and homogeneous UV-IR absorbent composition.

According to Table 7, the optical filters according to Examples 1 to 38 had the optical performances (i) to (vii) described above. Further, according to Table 11, Table 13, Table 15, Table 17, and Table 19, the optical filters according to Examples 1, 2, 16 to 18 further have the optical performances (viii) to (xi) described above. Was. Further, according to another result of the transmittance spectrum measurement regarding the optical filters according to Examples 3 to 15 and Examples 19 to 38 (incident angle: 0 ° to 65 °, not shown), the optics according to these examples. The filter also had the above-mentioned optical performances (viii) to (xi).

According to Table 9, the optical filter according to Comparative Example 1 did not have the optical performances (ii), (vi), and (vii) described above, and did not have the desired characteristics in the infrared region. .. Further, according to Comparative Calculation Example 1, by increasing the thickness of the UV-IR absorption layer, the characteristics in the infrared region can be improved, but the first IR cutoff wavelength is shortened (iv). It was suggested that performance could not be achieved. As described above, it was suggested that even if the UV-IR absorbing composition according to Comparative Example 1 was used, an optical filter having all the optical performances (i) to (v) above could not be produced. Similarly, according to the results of Comparative Example 2 and Comparative Calculation Example 2 and Comparative Example 3 and Comparative Calculation Example 3 in Table 9, even if the UV-IR absorbing composition according to Comparative Examples 2 and 3 is used, the above ( It was suggested that an optical filter having all the optical performances of i) to (v) could not be produced.

According to Table 9, the optical filter according to Comparative Example 4 did not have the optical performances (iii) and (v) above, and did not have the desired characteristics in the ultraviolet region. Further, according to Comparative Calculation Example 4-A, by increasing the thickness of the UV-IR absorption layer, the above (iii) and (v) are obtained.
It was suggested that although the optical performance of ()) can be realized, it is difficult to realize the optical performance of (i) above. Further, according to Comparative Calculation Example 4-B, by reducing the thickness of the UV-IR absorbing layer, the optical performance of the above (i) is improved, but the optical performance of the above (iii) and (v) is further improved. In addition, it was suggested that the maximum transmittance at wavelengths of 750 to 180 nm also increased. Therefore, it was suggested that an optical filter having all the optical performances (i) to (v) above could not be produced even by using the UV-IR absorbing composition according to Comparative Example 4.

According to Table 9, the optical filter according to Comparative Example 5 did not have the optical performances of (i) and (iv) above. According to Comparative Calculation Example 5, by reducing the thickness of the UV-IR absorbing layer, the average transmission rate at a wavelength of 450 to 600 nm is increased, but the IR cutoff wavelength hardly changes, and the maximum transmission at a wavelength of 750 to 80 nm. It was suggested that the rate would also increase. Therefore, it was suggested that the method for producing an optical filter according to Comparative Example 5 could not produce an optical filter having all the optical performances (i) to (v) above. Hydrolysis and polycondensation of the alkoxysilane monomer contained in the UV-IR absorbing composition are promoted by the humidification treatment, and in addition to the curing of the UV-IR absorbing layer, the humidification treatment shows the transmittance spectrum of the optical filter. Was also suggested to have an effect.

According to Table 9, the optical filter according to Comparative Example 6 did not have the optical performance described in (iv) above. According to Comparative Calculation Example 6, it was suggested that by reducing the thickness of the UV-IR absorbing layer, the IR cutoff wavelength was increased, but the maximum transmittance at a wavelength of 750 to 80 nm was also increased. Therefore, it was suggested that the method for producing an optical filter according to Comparative Example 6 could not produce an optical filter having all the optical performances (i) to (v) above. In particular, it was suggested that the conditions of the humidification treatment in Comparative Example 6 were not sufficient.

According to Table 9, the optical filter according to Comparative Example 7 did not have the optical performances of (i) and (iv) above. According to Comparative Calculation Example 7, it was suggested that by reducing the thickness of the UV-IR absorbing layer, the IR cutoff wavelength was increased, but the maximum transmittance at a wavelength of 750 to 80 nm was also increased. Therefore, it was suggested that the method for producing an optical filter according to Comparative Example 7 could not produce an optical filter having all the optical performances (i) to (v) above. In particular, it was suggested that the conditions of the humidification treatment in Comparative Example 7 were not sufficient.

As shown in Table 2, among the UV-IR absorbing compositions according to Examples 3 to 5, the content of n-butylphosphonic acid in the UV-IR absorbing composition according to Example 3 is the highest, and Example 5 The content of n-butylphosphonic acid in the UV-IR absorbing composition according to the above is the lowest. According to this and Table 8, when the content of alkyl-based phosphonic acid in the UV-IR absorbing composition is high, the wavelength range and the spectral transmittance in which the spectral transmittance is 1% or less at a wavelength of 700 to 1200 nm are increased. It was suggested that the wavelength range of 0.1% or less expands toward the long wavelength side. The same can be said for Examples 6 to 8, 9 and 10, and 11 to 15.

As shown in Table 2, among the UV-IR absorbing compositions according to Examples 11 to 15, the content of n-butylphosphonic acid in the UV-IR absorbing composition according to Example 11 was the highest, and Example 12 The content of n-butylphosphonic acid in the UV-IR absorbing composition according to Example 13 is the second highest, and the content of n-butylphosphonic acid in the UV-IR absorbing composition according to Example 13 is the third highest. , The content of n-butylphosphonic acid in the UV-IR absorbing composition according to Example 15 is the lowest. According to the results of Examples 11 to 15 in Table 7, the maximum transmittance of the optical filter at wavelengths of 1000 to 1100 nm and the maximum transmittance of the optical filter at wavelengths of 1100 to 1200 nm are the lowest in Example 11, and in Example 12. It is the second lowest, the third lowest in Example 13, and the highest in Example 15. This suggests that increasing the content of alkyl sulfonic acid in a predetermined range in the UV-IR absorbing composition improves the shielding property of the wavelength in the infrared region.

As shown in Table 2, among the UV-IR absorbing compositions according to Examples 7, 10 and 13, the content of 4-bromophenylphosphonic acid in the UV-IR absorbing composition according to Example 7 is the highest. , The content of 4-bromophenylphosphonic acid in the UV-IR absorbing composition according to Example 13 is the lowest. According to the results of Examples 7, 10 and 13 in Table 7, the higher the content of 4-bromophenylphosphonic acid in the UV-IR absorbing composition, the larger the UV cutoff wavelength. This suggests that the optical performance of the optical filter can be optimized by adjusting the content of 4-bromophenylphosphonic acid in the UV-IR absorbing composition.

UV-IR for producing optical filters according to Examples 22 to 37 and Comparative Examples 5 to 7.
Although the absorbent composition is prepared in the same manner as the UV-IR absorbent composition according to Example 2, as shown in Tables 7 to 10, the optical filters according to these Examples and these Comparative Examples are , It had different optical performance from the optical filter according to Example 2. As described above, the humidification treatment is carried out for the purpose of promoting the hydrolysis and contraction polymerization of the alkoxysilane contained in the UV-IR absorbing composition, but depending on the mode of the humidification treatment, these examples and these In the optical filter according to the comparative example of No. 1, there was a difference in the average transmittance and the IR cutoff wavelength at a wavelength of 450 to 600 nm.

According to the results of Comparative Calculation Examples 5 to 7 in Table 9, the UV cutoff wavelength can be adjusted by changing the thickness of the UV-IR absorbing layer, but according to the method for producing the optical filter according to Comparative Examples 5 to 7. , (I)-(xi), it is difficult to keep the IR cutoff wavelength within a desired range while satisfying the other optical performances. Therefore, the amount of water vapor (exposed water vapor amount) in the environment to which the article to be treated is exposed in the humidification treatment of each example and some of the comparative examples was determined as follows. The results are shown in Tables 3 and 6. The saturated water vapor pressure e [hPa] at the temperature t [° C.] was determined by the approximate expression of Tetens: e = 6.11 × 10 ^{(7.5t / (t + 237.3))} . From the saturated water vapor pressure e [hPa] and the relative humidity φ [%], the water vapor density ρv [g / m ³ ] was calculated from the formula ρv = 217 × e × φ / (t + 273.15). The amount of water vapor x time [mol / m ³ · hour] was defined as the amount of exposed water vapor. As shown in Tables 3 and 6, it was suggested that in the humidification treatment, good optical performance can be obtained when the temperature is 60 ° C. or higher, the relative humidity is 70% or higher, and the treatment time is 1 hour or longer. This treatment condition corresponds to the condition of the amount of exposed water vapor of 5.0 [mol / m ³ hours] or more, but when the temperature in the humidification treatment is as low as 40 ° C. and the relative humidity is 70%, and when the humidity is humidified. It was suggested that even when the temperature in the treatment is 60 ° C. and the relative humidity is as low as 40%, good optical performance can be obtained by extending the treatment time to the same amount of exposed water vapor. From these results, it was suggested that it is desirable to perform the humidification treatment for a short time in an environment of a temperature of 60 ° C. or higher and a relative humidity of 70% or higher from the viewpoint of efficiently bringing good optical performance to the optical filter.

1a to 1f Optical filter 2 Lens system 3 Low-pass filter 4 Imaging element 5 Circuit board 7 Optical filter support housing 8 Optical system housing 10 UV-IR absorption layer 20 Transparent dielectric substrate 30 Antireflection film 40 Antireflection film 100 Camera module

Claims (9)

It has a UV-IR absorption layer that can absorb some infrared rays and ultraviolet rays.
When light with a wavelength of 300 nm to 1200 nm is incident at an incident angle of 0 °,
It has an average transmittance of 78% or more at wavelengths of 450 nm to 600 nm.
The first IR cutoff wavelength, which has a spectral transmittance that decreases with increasing wavelength at a wavelength of 600 nm to 750 nm and exhibits a spectral transmittance of 50% at a wavelength of 600 nm to 750 nm, exists in the wavelength range of 620 nm to 680 nm.
The first UV cutoff wavelength, which has a spectral transmittance that increases with an increase in wavelength at a wavelength of 350 nm to 450 nm and exhibits a spectral transmittance of 50% at a wavelength of 350 nm to 450 nm, exists in the wavelength range of 380 nm to 430 nm.
The maximum value of transmittance at wavelengths of 1000 nm to 1100 nm is 3% or less.
The maximum value of the transmittance at a wavelength 1100nm~1200nm when the incident angle is 40 ° is rather smaller than the maximum value of the transmittance at a wavelength 1100nm~1200nm when the incident angle is 0 °,
The first UV cutoff wavelength is smaller than the second UV cutoff wavelength, which shows 50% spectral transmittance at a wavelength of 350 nm to 450 nm when light having a wavelength of 300 nm to 1200 nm is incident at an incident angle of 40 °.
Optical filter. The difference between the second IR cutoff wavelength, which shows a spectral transmittance of 50% at a wavelength of 600 nm to 750 nm, and the first IR cutoff wavelength when light having a wavelength of 300 nm to 1200 nm is incident at an incident angle of 40 °. The absolute value is 10 nm or less,
Said second UV cutoff wavelength, the absolute value of the difference between the first UV cutoff wavelength of 10nm or less,
The optical filter according to claim 1. The first IR cutoff wavelength, has a spectral transmittance at a wavelength 600nm~750nm is greater than the second IR cutoff wavelength showing 50% when applying a light having a wavelength 300nm~1200nm at an angle of incidence of 40 °, the optical filter according to請Motomeko 1 or 2. The optical filter according to any one of claims 1 to 3 , wherein the maximum value of the transmittance at a wavelength of 1100 nm to 1200 nm is 15% or less when the incident angle is 0 °. The difference between the third IR cutoff wavelength, which shows a spectral transmittance of 50% at a wavelength of 600 nm to 750 nm, and the first IR cutoff wavelength when light having a wavelength of 300 nm to 1200 nm is incident at an incident angle of 50 °. Absolute value is 15 nm or less,
The difference between the third UV cutoff wavelength, which shows 50% spectral transmittance at a wavelength of 350 nm to 450 nm when light having a wavelength of 300 nm to 1200 nm is incident at an incident angle of 50 °, and the first UV cutoff wavelength. Absolute value is 15 nm or less,
The optical filter according to any one of claims 1 to 4 . The optical filter according to any one of claims 1 to 5 , wherein at an incident angle of 0 ° to 65 °, the maximum value of the transmittance at a wavelength of 1100 nm to 1200 nm decreases as the incident angle increases. The optical filter according to any one of claims 1 to 6 , wherein the UV-IR absorbing layer has a thickness of 132 μm to 215 μm. The optical filter according to any one of claims 1 to 7 , further comprising a transparent dielectric substrate. A camera module comprising the optical filter according to any one of claims 1 to 8 .

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