JP2019028431A - Ur-ir absorbent composition - Google Patents

Abstract

To provide an optical filter capable of exerting desired optical performance with a simple configuration.SOLUTION: An optical filter (1a) is provided with a UV-IR absorption layer and has characteristics (i) to (v) indicated below when light having wavelength of 300-1200 nm is incident thereon at an angle of incidence of 0°. (i) Average transmittance in wavelength of 450-600 nm is 78% or more. (ii) Spectral transmittance in wavelength of 750-1080 nm is 1% or less. (iii) Spectral transmittance in wavelength of 300-350 nm is 1% or less. (iv) Spectral transmittance decreases together with increase in wavelength in wavelength of 600-750 nm, and first IR cutoff wavelength is present in a range of wavelength of 620-680 nm. (v) Spectral transmittance increases together with increase in wavelength in wavelength of 350-450 nm, and first UV cutoff wavelength is present in a range of wavelength of 380-430 nm.SELECTED DRAWING: Figure 1A

Description

  The present invention relates to an optical filter.

  In an imaging apparatus using an imaging device such as a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor), various optical filters are arranged on the front surface of the imaging device in order to obtain an image having good color reproducibility. Yes. In general, an image sensor has spectral sensitivity in a wide wavelength range from an ultraviolet region to an infrared region. On the other hand, human visibility exists only in the visible light region. For this reason, a technique is known in which an optical filter that shields infrared rays or ultraviolet rays is disposed on the front surface of an image pickup element in order to bring the spectral sensitivity of the image pickup element in the image pickup apparatus close to human visibility.

  Examples of the optical filter include an optical filter that uses reflection of light, 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 are optical filters that use absorption of light. The latter is desirable in that it has a spectral characteristic that hardly varies with the incident angle of incident light.

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

JP 2011-203467 A

  Although the near-infrared absorption filter described in Patent Document 1 can effectively absorb light at wavelengths of 800 nm to 1200 nm, it is difficult to say that it has desirable light absorption characteristics at wavelengths of 350 nm to 400 nm and wavelengths of 650 nm to 800 nm. . Therefore, the present invention provides an optical filter that can exhibit desired optical performance, which is difficult to achieve with only the near-infrared absorption filter described in Patent Document 1, with a simple configuration.

The present invention
It has a UV-IR absorption layer that can absorb infrared and ultraviolet rays,
When light having a wavelength of 300 nm to 1200 nm is incident at an incident angle of 0 °,
(I) having an average transmittance of 78% or more at a wavelength of 450 nm to 600 nm;
(Ii) having a spectral transmittance of 1% or less at wavelengths of 750 nm to 1080 nm,
(Iii) having a spectral transmittance of 1% or less at a wavelength of 300 nm to 350 nm,
(Iv) The first IR cut-off wavelength having a spectral transmittance that decreases with an increase in wavelength at a wavelength of 600 nm to 750 nm and a spectral transmittance of 50% at a wavelength of 600 nm to 750 nm is within the wavelength range of 620 nm to 680 nm. Exists,
(V) A first UV having a spectral transmittance that increases with an increase in wavelength at a wavelength of 350 nm to 450 nm and a spectral transmittance of 50% at a wavelength of 350 nm to 450 nm.
The cutoff wavelength is in the wavelength range of 380 nm to 430 nm,
An optical filter is provided.

  The above optical filter can exhibit desired optical performance with 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 the transmittance spectrum of the infrared-absorbing glass substrate used in Example 21. FIG. 8B is a transmittance spectrum of the optical filter according to Example 21. FIG. 9 is a transmittance spectrum of the optical filter according to Example 22. FIG. 10 is a transmittance spectrum of the optical filter according to Example 23. FIG. 11 is a transmittance spectrum of the optical filter according to Example 24. FIG. 12 is a transmittance spectrum of the optical filter according to Example 38.

  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 to these.

  The optical filter may desirably have characteristics 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 does not emit light having a wavelength of 350 nm to 400 nm and light having a wavelength of 650 nm to 800 nm. In order to cut, another light absorption layer or light reflection film is required. As described above, it is not easy to realize an optical filter having the above desirable characteristics with a simple configuration (for example, a single layer). Actually, the present inventor repeated trial and error many times in order to realize an optical filter having the above-mentioned desirable characteristics with a simple configuration. As a result, the inventor finally devised an optical filter according to the present invention.

As shown in FIG. 1A, the optical filter 1 a includes a UV-IR absorption layer 10. The UV-IR absorption layer 10 is a layer that can absorb 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 transmittance of 78% or more at wavelengths of 450 nm to 600 nm (ii) Spectral transmittance of 1% or less at wavelengths of 750 nm to 1080 nm (iii) Spectral transmittance of 1% or less at wavelengths of 300 nm to 350 nm (iv) Wavelength of 600 nm Spectral transmittance decreasing with increasing wavelength at ˜750 nm, and first IR cutoff wavelength (v) existing within the wavelength range of 620 nm to 680 nm (v) Spectral transmittance and wavelength increasing with increasing wavelength at 350 nm to 450 nm First UV cutoff wavelength present in the range of 380 nm to 430 nm

  In this specification, “spectral transmittance” is transmittance when incident light of a specific wavelength is incident on an object such as a sample, and “average transmittance” is spectral transmittance within a predetermined wavelength range. The “maximum transmittance” is the maximum value of spectral transmittance within a predetermined wavelength range. Further, in this specification, the “transmittance spectrum” is obtained by arranging spectral transmittances at respective wavelengths within a predetermined wavelength range in order of wavelength.

  In this 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 the optical filter at a predetermined incident angle. It means wavelength. The “first IR cutoff wavelength” is an IR cutoff wavelength when light is incident on the optical filter at an incident angle of 0 °. In addition, the “UV cutoff wavelength” is a wavelength indicating a spectral transmittance of 50% in a wavelength range of 450 nm or less when light having a wavelength of 300 nm to 1200 nm is incident on the optical filter at a predetermined incident angle. means. The “first UV cutoff wavelength” is a UV cutoff wavelength when light is incident on the optical filter at an incident angle of 0 °.

  When the optical filter 1a exhibits the optical performances (i) to (v) described above, the optical filter 1a has a large amount of transmitted 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. For this reason, 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, even if the optical filter 1a is not provided with a layer other than the UV-IR absorption layer 10, the optical performances (i) to (v) described above can be exhibited.

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

Regarding the above (iii), the optical filter 1a desirably has a wavelength of 300 nm to 360 nm.
And has a spectral transmittance of 1% or less. Thereby, the optical filter 1a can cut light in the ultraviolet region more effectively.

  Regarding the above (iv), the first IR cut-off wavelength (wavelength exhibiting a spectral transmittance of 50%) is desirably in the wavelength range of 630 nm to 650 nm. Thereby, the transmission spectrum of the optical filter 1a is more suitable for human visibility.

  With regard to (v) above, the first UV cutoff wavelength (wavelength exhibiting a spectral transmittance of 50%) is desirably in the wavelength range of 390 nm to 420 nm. Thereby, the transmission spectrum of the optical filter 1a is more suitable for human visibility.

The optical filter 1a desirably 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 °. Thereby, infrared rays having a relatively long wavelength (wavelength 1000 to 1100 nm) can be shielded. Conventionally, in order to cut light of this wavelength, a light reflecting film made of a dielectric multilayer film is often used. However, according to the optical filter 1a, light having this wavelength can be effectively cut without using such a dielectric multilayer film. Even if a light reflection film composed of a dielectric multilayer film is required, the level of reflection performance required for the light reflection film can be lowered, so the number of dielectric layers in the light reflection film can be reduced, and the light reflection film The cost required for formation can be reduced.
(Vi) Spectral transmittance of 3% or less at a wavelength of 1000 to 1100 nm

The optical filter 1a desirably 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 (
1100-1200 nm) can be cut. As a result, the optical filter 1a can effectively cut light of this wavelength without using a dielectric multilayer film or even when the number of dielectric layers in the dielectric multilayer film is small.
(Vii) Spectral transmittance of 15% or less at a wavelength 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 an 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 in the vicinity of the first IR cutoff wavelength of the optical filter 1a is unlikely to vary with respect to the incident angle of the light incident on the optical filter 1a. As a result, it is possible to suppress the occurrence of different colors at the central portion and the peripheral portion of the image obtained by the imaging device in which the optical filter 1a is disposed in front of the imaging device.

  In the optical filter 1a, the absolute value of the difference between the second IR cutoff wavelength and the first IR cutoff wavelength is desirably 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 greatly, it is possible to suppress the change in the transmittance characteristic near the first IR cutoff wavelength of the optical filter 1a. As a result, even if the optical filter 1a is arranged in front of the imaging device of the imaging device capable of imaging with a wide angle of view, a high-quality image is 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 an 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 imaging device of the imaging device capable of imaging with a wide angle of view, a high-quality image is 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 in the vicinity of the first UV cutoff wavelength of the optical filter 1a is unlikely to change with respect to the incident angle of the light incident on the optical filter 1a. As a result, it is possible to suppress the occurrence of different colors at the central portion and the peripheral portion of the image obtained by the imaging device in which the optical filter 1a is disposed in front of the imaging device.

  In the optical filter 1a, the absolute value of the difference between the second UV cutoff wavelength and the first UV cutoff wavelength is desirably 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 greatly, it is possible to suppress a change in the transmittance characteristic near the first UV cutoff wavelength of the optical filter 1a. As a result, even if the optical filter 1a is arranged in front of the imaging device of the imaging device capable of imaging with a wide angle of view, a high-quality image is 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 imaging device of the imaging device capable of imaging with a wide angle of view, a high-quality image is easily obtained.

The optical filter 1a desirably 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 desirably 0.1% or less of spectral transmittance at a wavelength of 800 to 950 nm

The optical filter 1a desirably 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 desirably 0.1% or less of spectral transmittance at a wavelength of 800 to 1000 nm

  Each color filter corresponding to RGB used in the imaging apparatus may not only transmit light in a wavelength range corresponding to each RGB but also transmit light having a wavelength of 800 nm or more. For this reason, unless the spectral transmittance in the wavelength range of the infrared cut filter used in the imaging device is low to some extent, the light in the wavelength range enters the pixel of the imaging element, and a signal is output from the pixel. . When a digital image is acquired using such an imaging device, if the amount of light in the visible light region is sufficiently strong, it can be obtained even if low-intensity infrared rays pass through the color filter and the pixels of the imaging device receive light. There is no big impact on digital images. However, when the amount of light in the visible light region is small or in the dark part of an image, it is easily affected by such infrared rays, and sometimes blue or reddish colors are mixed in those images.

As described above, a color filter used together with an image sensor such as a CMOS and a CCD may transmit light in a wavelength range of 800 to 950 nm or 800 to 1000 nm. Since the optical filter 1a has the optical performances (xii) and (xiii) described above, 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) described above. Contains the formed UV-IR absorber.

  When the UV-IR absorption layer 10 includes a UV-IR absorber formed by phosphonic acid and copper ions, the phosphonic acid includes, for example, a first phosphonic acid having an aryl group. In the first phosphonic acid, the aryl group is bonded to the phosphorus atom. Thereby, the optical filter 1a tends to exhibit the optical performance of said (i)-(v).

The aryl group of the first 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 substituted 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 first phosphonic acid has, in part, a halogenated phenyl group. In this case, the optical filter 1a can easily exhibit the optical performances (i) to (v) more reliably.

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

  The alkyl group that the second phosphonic acid has 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 absorber layer 10 includes a UV-IR absorber formed by phosphonic acid and copper ions, the UV-IR absorber layer 10 desirably includes a phosphate ester that disperses the UV-IR absorber; And a matrix resin.

The phosphate ester contained in the UV-IR absorption layer 10 is not particularly limited as long as the UV-IR absorber can be appropriately dispersed. For example, the phosphate diester represented by the following formula (c1) and the following formula ( at least one of phosphoric acid monoesters represented by c2). In the following formula (c1) and the following formula (c2), R ₂₁ , R ₂₂ , and R ₃ are each a monovalent functional group represented by — (CH ₂ CH ₂ O) _n R ₄ , 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 the same or different types of functional groups.

  The phosphate ester is not particularly limited. For example, Plysurf A208N: polyoxyethylene alkyl (C12, C13) ether phosphate ester, Plysurf A208F: polyoxyethylene alkyl (C8) ether phosphate ester, Plysurf A208B: Polyoxyethylene lauryl ether phosphate ester, plysurf A219B: polyoxyethylene lauryl ether phosphate ester, plysurf AL: polyoxyethylene styrenated phenyl ether phosphate ester, plysurf A212C: polyoxyethylene tridecyl ether phosphate ester Or Plysurf A215C: Polyoxyethylene tridecyl ether phosphate. These are all products manufactured by Daiichi Kogyo Seiyaku. Further, the phosphate ester is NIKKOL DDP-2: polyoxyethylene alkyl ether phosphate ester, NIKKOL DDP-4: polyoxyethylene alkyl ether phosphate ester, or NIKKOL DDP-6: polyoxyethylene alkyl ether phosphate ester. possible. These are all products manufactured by Nikko Chemicals.

The matrix resin contained in the UV-IR absorption layer 10 is, for example, a resin that can disperse a UV-IR absorber and can be cured by heat or ultraviolet light. Furthermore, when a 0.1 mm resin layer is formed of 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, desirably 75% or more, and more desirably. May be a resin that is 80% or more. 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 absorption layer 10 is not particularly limited as long as the above properties are satisfied. For example, (poly) olefin resin, polyimide resin, polyvinyl butyral resin, polycarbonate resin, polyamide resin, polysulfone resin, polyether Sulphone resin, polyamideimide resin, (modified) acrylic resin, epoxy resin, or 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 absorption layer 10 is hard (rigid), as the thickness of the UV-IR absorption layer 10 increases, cracks tend to occur due to curing shrinkage during the manufacturing process of the optical filter 1a. When the matrix resin is a silicone resin containing an aryl group, the UV-IR absorption layer 10 tends to have good crack resistance. In addition, when a silicone resin containing an aryl group is used, the UV-IR absorber hardly aggregates when it contains the UV-IR absorber formed by the phosphonic acid and copper ions. Further, when the matrix resin of the UV-IR absorption layer 10 is a silicone resin containing an aryl group, the phosphoric acid ester contained in the UV-IR absorption layer 10 is a 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. Because of the interaction based on the combination of the above-described phosphonic acid, a silicone resin containing an aryl group, and a phosphate ester having a linear organic functional group such as an oxyalkyl group, the UV-IR absorber is unlikely to aggregate, In addition, the UV-IR absorption layer can be provided with good rigidity and good flexibility. 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. These are all silicone resins manufactured by Shin-Etsu Chemical Co., Ltd.

  As shown in FIG. 1A, the optical filter 1 a 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 the UV-IR absorption 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) at 450 nm to 600 nm. In some cases, the transparent dielectric substrate 20 may have an absorptivity in the ultraviolet region or the 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. Infrared absorbing glass such as phosphate glass or fluorophosphate glass containing copper. When the transparent dielectric substrate 20 is an infrared absorbing glass such as a phosphate glass containing copper or a fluorophosphate glass containing copper, the infrared absorbing performance and UV of the transparent dielectric substrate 20 are included. -The infrared absorption performance required for the optical filter 1a can be realized in combination with the infrared absorption performance of the IR absorption layer 10. For this reason, 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 Schott, 500EXL manufactured by Nippon Electric Glass, or HOYA. CM5000, CM500, C5000, or C500S manufactured by the company. Further, the infrared absorbing glass may have an ultraviolet absorbing property.

The transparent dielectric substrate 20 may be a crystalline substrate having transparency such as magnesium oxide, sapphire, or quartz. For example, since sapphire has high hardness, it is hard to be damaged. For this reason, the plate-like sapphire may be disposed as a scratch-resistant protective material (protect filter) in front of a camera module or a lens provided in a mobile terminal such as a smartphone or a mobile phone. By forming the UV-IR absorption layer 10 on such plate-like sapphire, it is possible to shield ultraviolet rays or infrared rays as well as protecting the camera module and the lens. This eliminates the need to arrange an optical filter having ultraviolet or infrared shielding properties around an image sensor such as a CCD or CMOS or inside a camera module. For this reason, if the UV-IR absorption layer 10 is formed on the plate-like sapphire, it can contribute to the low profile of the camera module.

  When the transparent dielectric substrate 20 is made of a resin, the resin is, for example, (poly) olefin resin, polyimide resin, polyvinyl butyral resin, polycarbonate resin, polyamide resin, polysulfone resin, polyethersulfone 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.

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

  First, an example of a method for preparing a UV-IR absorbing 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 copper salt solution. 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. Also, the first phosphonic acid is added to a predetermined solvent such as THF and stirred to prepare a liquid B. When a plurality of types of phosphonic acid are used as the first phosphonic acid, the phosphonic acid is added to a predetermined solvent such as THF and stirred, and a plurality of preliminary solutions prepared for each type of phosphonic acid are mixed to prepare a solution B May be prepared. Desirably, an alkoxysilane monomer is added in the preparation of solution B.

  When an alkoxysilane monomer is added to the UV-IR absorbing composition, the particles of the UV-IR absorber can be prevented from aggregating with each other, so even if the phosphate ester content is reduced, the UV-IR absorbing property can be reduced. The UV-IR absorber is well dispersed in the composition. Further, when the optical filter 1a is produced using the UV-IR absorbing composition, a siloxane bond (—Si—O) is obtained by treating the alkoxysilane monomer so that hydrolysis reaction and condensation polymerization 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 higher bond energy and is chemically stable than bonds such as -C-C- bond and -C-O- bond, and is excellent in heat resistance and moisture resistance.

Next, while stirring the liquid A, the liquid B is added to the liquid A and stirred for a predetermined time. Next, a predetermined solvent such as toluene is added to this solution and stirred to obtain liquid C. Next, desolvation treatment is performed for a predetermined time while heating the C liquid to obtain the D liquid. Thereby, 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 generated by the first 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 that has dissociated from the copper salt. In the solvent removal treatment, C
Solvents such as toluene (boiling point: about 110 ° C.) used to obtain the liquid also volatilize. Since it is desirable for this solvent to remain to some extent in the UV-IR absorbing composition, the addition amount of the solvent and the time for desolvation treatment are preferably determined from this viewpoint. In addition, in order to obtain C liquid, it can replace with toluene and can use o-xylene (boiling point: about 144 degreeC). In this case, since the boiling point of o-xylene is higher than that of toluene, the addition amount can be reduced to about one-fourth of the addition amount of toluene.

  When the UV-IR absorbing composition further contains a secondary phosphonic acid, for example, liquid H is further prepared 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 copper salt solution. 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 copper salt solution and stirred to prepare a solution E. To do. Further, the second phosphonic acid is added to a predetermined solvent such as THF and stirred to prepare a solution 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 stirred to mix a plurality of preliminary solutions prepared for each type of secondary phosphonic acid. The F solution may be prepared. While stirring E liquid, F liquid is added to E liquid and stirred for a predetermined time. Next, a predetermined solvent such as toluene is added to this solution and stirred to obtain a solution G. Next, a solvent removal process is performed for a predetermined time while the G solution is heated to obtain the H solution. Thereby, components generated by dissociation of a solvent such as THF and a copper salt such as acetic acid are removed, and another UV-IR absorber is generated by the second phosphonic acid and the copper ion. The temperature for heating the G liquid is determined in the same manner as in the C liquid, and the solvent for obtaining the G liquid is also determined in the same manner as in the C liquid.

  A UV-IR absorbing composition can be prepared by adding a matrix resin such as a silicone resin to D solution and stirring. In addition, when the UV-IR absorbing composition contains a UV-IR absorber formed by the second phosphonic acid and copper ions, it is obtained by adding a matrix resin such as a silicone resin to the liquid D and stirring. A UV-IR absorbing composition can be prepared by further adding H solution to the obtained I solution and stirring.

The UV-IR absorbing composition is applied to one main surface of the transparent dielectric substrate 20 to form a coating film. For example, a liquid UV-IR absorbing composition is applied to one main surface of the transparent dielectric substrate 20 by spin coating or dispenser coating to form a coating film. Next, the coating film is cured by performing a predetermined heat treatment on 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 absorbing 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%. Thereby, a repeating structure (Si—O) _{n of} siloxane bonds is formed. In this way
The optical filter 1a can be manufactured. In general, in the hydrolysis and polycondensation reaction of an alkoxysilane containing a monomer, the alkoxysilane and water may coexist in the liquid composition to cause these reactions. However, if water is added to the UV-IR absorbing composition in advance when manufacturing the optical filter, the phosphate ester or the UV-IR absorber is deteriorated in the process of forming the UV-IR absorbing layer. , UV-IR absorption performance may be deteriorated and durability of the optical filter may be impaired. For this reason, it is desirable to perform a humidification process after hardening a coating film by predetermined | prescribed heat processing.

  When the transparent dielectric substrate 20 is a glass substrate, in order to improve the adhesion between the transparent dielectric substrate 20 and the UV-IR absorption layer 10, a resin layer containing a silane coupling agent is applied to the transparent dielectric substrate 20 and the UV. -You may form between IR absorption layers 10.

<Modification>
The optical filter 1a can be changed from various viewpoints. For example, the optical filter 1a is
The optical filters 1b to 1f shown in FIGS. 1B to 1F may be changed. The optical filters 1b to 1f are configured in the same manner as the optical filter 1a unless otherwise described. Constituent elements of the optical filters 1b to 1f that are the same as or correspond to the constituent elements of the optical filter 1a are denoted by the same reference numerals, and detailed description thereof is omitted. The description regarding the optical filter 1a also applies to the optical filters 1b to 1f unless there is a technical contradiction.

  As shown in FIG. 1B, an optical filter 1 b according to another example of the present invention has UV-IR absorption layers 10 formed on both main surfaces of a transparent dielectric substrate 20. As a result, the optical filter 1b can exhibit the optical performances (i) to (v) described above not by the single UV-IR absorption layer 10 but by the two UV-IR absorption layers 10. The thickness of the UV-IR absorption layer 10 on both main surfaces of the transparent dielectric substrate 20 may be the same or different. That is, the UV-IR absorption layer 10 necessary for the optical filter 1b to obtain desired optical characteristics is uniformly or non-uniformly distributed on both main surfaces of the transparent dielectric substrate 20 with UV. -IR absorption layer 10 is formed. Thereby, the thickness of each UV-IR absorption layer 10 formed on both main surfaces of the transparent dielectric substrate 20 is relatively small. Thereby, the internal pressure of a coating film is low and generation | occurrence | production of a crack can be prevented. Moreover, 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 absorption layer 10 is formed only on one main surface of the transparent dielectric substrate 20, the UV-IR absorption layer 10 is formed from the UV-IR absorbing composition. There is a possibility that the optical filter is warped by the stress caused by the shrinkage. However, since the UV-IR absorption layer 10 is formed on both main surfaces of the transparent dielectric substrate 20, even when the transparent dielectric substrate 20 is thin, warpage is suppressed in the optical filter 1b. Also in this case, in order to improve the adhesion between the transparent dielectric substrate 20 and the UV-IR absorption layer 10, a resin layer containing a silane coupling agent is interposed between the transparent dielectric substrate 20 and the UV-IR absorption layer 10. You may form in.

As shown in FIG. 1C, the optical filter 1 c according to another example of the present invention includes an antireflection film 30. The antireflection film 30 is a film that is formed so as to form an interface between the optical filter 1c and the air and reduces reflection of light in the visible light region. The antireflection film 30 is a film formed of a dielectric material such as resin, oxide, and fluoride. The antireflection film 30 may be a multilayer film formed by laminating two or more kinds of dielectrics having different refractive indexes. In particular, the antireflection film 30 may be a dielectric multilayer film made 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 absorption layer 10, a resin layer containing a silane coupling agent is interposed between the transparent dielectric substrate 20 and the UV-IR absorption layer 10. You may form in. In some cases, a resin layer containing a silane coupling agent may be formed between the UV-IR absorption layer 10 and the antireflection film 30 in order to improve the adhesion of the antireflection film 30. The antireflection film 30 may be disposed on both main surfaces of the optical filter 1c, or may be disposed only on one main surface.

  As illustrated in FIG. 1D, the optical filter 1 d according to another example of the present invention is configured by only the UV-IR absorption layer 10. For example, the optical filter 1d forms a coating film by applying a UV-IR absorbing composition to a predetermined substrate such as a glass substrate, a resin substrate, or a metal substrate (for example, a steel substrate or a stainless steel substrate). Can be produced by peeling the substrate from the substrate. 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. For this reason, the optical filter 1d can contribute to lowering the height of the imaging device and the optical system.

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

As shown in FIG. 1F, an optical filter 1f according to another example of the present invention includes a UV-IR absorption layer 10 and a reflective film 40 that reflects infrared rays and / or ultraviolet rays disposed on one main surface thereof. I have. The reflective film 40 is, for example, a film formed by vapor deposition of 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 _{TiO 2, ZrO 2, Ta 2} O 5, Nb 2 O 5, ZnO, and In ₂ O ₃ material having a refractive index of 1.7 to 2.5, such as are 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 MgF ₂ is used. A method for forming the dielectric multilayer film is, for example, a chemical vapor deposition (CVD) method, a sputtering method, or a vacuum deposition method. Further, such a reflective film may be formed so as to form both main surfaces of the optical filter (not shown). When reflective films are formed on both main surfaces of the optical filter, the stress is balanced on both the front and back surfaces of the optical filter, so that the optical filter is less likely to warp.

  Each of the optical filters 1a to 1f may be modified to include an infrared absorption film (not shown) separately from the UV-IR absorption layer 10 as necessary. The infrared absorbing film contains, for example, an organic infrared absorbing agent such as cyanine-based, phthalocyanine-based, squarylium-based, diimmonium-based, and azo-based or an infrared absorbing agent made of a metal complex. The infrared absorbing 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 in a specific range of wavelengths.

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

  The above infrared absorber or ultraviolet absorber may be preliminarily contained in the resin-made transparent dielectric substrate 20. The infrared absorbing film and the ultraviolet absorbing film can be formed, for example, by forming a resin 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 be transparent. Such resins include (poly) olefin resins, polyimide resins, polyvinyl butyral resins, polycarbonate resins, polyamide resins, polysulfone resins, polyethersulfone resins, polyamideimide resins, (modified) acrylic resins, epoxy resins, and silicone resins. Can be illustrated.

Each of the optical filters 1a to 1f may be modified so as to further include a reflective film that reflects infrared rays and / or ultraviolet rays, as 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 surfaces of the optical filter, and the optical filter is less likely to warp. If the reflective film is a dielectric multilayer film, for example, TiO ₂ as a high refractive index _{material, ZrO 2, Ta 2 O 5} , Nb 2 O 5, ZnO, and the like In ₂ O ₃ 1.7~2. A material having a refractive index of 5 is used, and a material having a refractive index of 1.2 to 1.6 such as SiO ₂ , Al ₂ O ₃ , and MgF ₂ is used as the low refractive index material. A method for forming the dielectric multilayer film is, for example, a chemical vapor deposition (CVD) method, a sputtering method, or a vacuum deposition method.

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

  Moreover, as shown in FIG. 2, for example, the camera module 100 using the 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 sensor 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 into an annular recess that is in contact with an opening formed in the center of the optical filter support housing 7, for example. The optical filter support housing 7 is fixed to the optical system housing 8. Inside the optical system casing 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, a CCD or a CMOS. Light from the subject is condensed by the lens system 2 after being cut off by the optical filter 1 a by ultraviolet rays and infrared rays, 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 (protect filter) for protecting the lens system 2. In this case, a sapphire substrate is preferably used as the transparent dielectric substrate 20 in the optical filter 1a. Since the sapphire substrate has high scratch resistance, for example, it is desirable that the sapphire substrate is disposed on the outer side (the side opposite to the imaging element 4 side). As a result, the optical filter 1a has high scratch resistance against external contact and the like, and has the optical performances (i) to (v) (desirably further optical performances (vi) to (xiii)). Have. As a result, it is not necessary to dispose an optical filter for cutting infrared rays or ultraviolet rays in the vicinity of the image sensor 4 and the camera module 100 can be easily lowered. Note that the camera module 100 shown in FIG. 2 is a schematic diagram for illustrating the arrangement and the like of each component, and explains an aspect in which the optical filter 1a is used as a protection filter. As long as the optical filter 1a functions as a protection filter, the camera module using the optical filter 1a is not limited to that shown in FIG. 2, and the low-pass filter 3 may be omitted as necessary. Other filters may be provided.

  The examples illustrate the invention in more detail. The present invention is not limited to the following examples. First, the evaluation method of the optical filter which concerns on an Example and a comparative example is demonstrated.

<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 (product name: V-670 manufactured by JASCO Corporation). . The transmittance spectrum at each angle was measured by changing the incident angle of the incident light with respect to the optical filter in increments of 5 ° from 0 ° to 65 °.

<Measurement of thickness of UV-IR absorption layer>
The thickness of the optical filter which concerns on an Example and a comparative example was measured with the digital micrometer. For optical filters having a transparent dielectric substrate such as glass among the optical filters according to Examples and Comparative Examples, UV-IR absorption in the optical filter is obtained by subtracting the thickness of the glass substrate from the thickness of the optical filter measured with a digital micrometer. The layer thickness 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 Prisurf A208N (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 Liquid A. To 0.441 g of phenylphosphonic acid (C ₆ H ₅ PO (OH) ₂ ) (manufactured by Nissan Chemical Industries), 10 g of THF was added and stirred for 30 minutes.
One liquid was obtained. To 0.661 g of 4-bromophenylphosphonic acid (C ₆ H ₄ BrPO (OH) ₂ ) (manufactured by Tokyo Chemical Industry Co., Ltd.), 10 g of THF was added and stirred for 30 minutes to obtain a liquid B-2. Next, the B-1 liquid and the B-2 liquid are mixed and stirred for 1 minute, and 1.934 g of methyltriethoxysilane (MTES: CH ₃ Si (OC ₂ H ₅ ) ₃ ) (manufactured by Shin-Etsu Chemical Co., Ltd.) Tetraethoxysilane (TEOS: Si (OC ₂ H ₅ ) ₄ ) (special grade made by Kishida Chemical Co., Ltd.) 0.634 g was added to add 1
Stirring was performed for a minute to obtain liquid B. Liquid B was added to liquid A while stirring liquid A, and the mixture was stirred at room temperature for 1 minute. Next, 25 g of toluene was added to this solution, followed by stirring at room temperature for 1 minute to obtain a liquid C. The solution C was put into a flask and heated with an oil bath (Tokyo Rika Kikai Co., Ltd., model: OSB-2100), and the solvent was removed by a rotary evaporator (Tokyo Rika Kikai Co., Ltd., model: N-1110SF). went. The set temperature of the oil bath was adjusted to 105 ° C. Thereafter, the liquid D after the solvent removal treatment 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.

Copper acetate monohydrate 0.225 g and THF 36 g were mixed and stirred for 3 hours to obtain a copper acetate solution. Next, 0.129 g of PRISURF A208N, which is a phosphate ester compound, was added to the obtained copper acetate solution and stirred for 30 minutes to obtain solution E. In addition, n-butylphosphonic acid (C ₄
10 g of THF was added to 0.144 g of H ₉ PO (OH) ₂ ) (manufactured by Nippon Chemical Industry Co., Ltd.), and the mixture was stirred for 30 minutes to obtain Liquid F. While stirring E solution, F solution was added to E solution and stirred at room temperature for 1 minute. Next, 25 g of toluene was added to this solution, followed by stirring at room temperature for 1 minute to obtain a solution G. The solvent G was put into a flask and heated with an oil bath, and the solvent was removed by a rotary evaporator. The set temperature of the oil bath was adjusted to 105 ° C. Thereafter, the liquid H after the solvent removal treatment was taken out from the flask. The 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 the D liquid and stirred for 30 minutes to obtain a I liquid. Liquid H was added to liquid I and stirred for 30 minutes to obtain a UV-IR absorbing composition (liquid J) according to Example 1. For the UV-IR absorbing composition (liquid J) according to Example 1, the content of each component on the basis of mass is shown in Table 1, the content on the basis of the amount of each component and the basis of the amount of each phosphonic acid The content 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 the range of 30 mm x 30 mm at the center of one main surface of a transparent glass substrate (product name: D263, manufactured by SCHOTT) made of borosilicate glass having dimensions of 76 mm x 76 mm x 0.21 mm A 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%. In order to prevent the coating solution from flowing out when the UV-IR absorbing composition is applied to the transparent glass substrate, a frame having an opening corresponding to the coating range of the coating solution was placed on the transparent glass substrate to block the coating solution. . A coating film having a target thickness was obtained by adjusting the amount of the coating solution. Next, the transparent glass substrate having an undried coating film was put in an oven and heat-treated at 85 ° C. for 6 hours to cure the coating film. Thereafter, the transparent glass substrate on which the above-mentioned coating film is formed is 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 is applied on the transparent glass substrate. The optical filter according to Example 1 in which the absorption layer was formed was obtained. The humidification treatment promotes hydrolysis and polycondensation of alkoxysilane contained in the UV-IR absorbing composition applied on the transparent glass substrate to form 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 transmittance spectrum of the optical filter according to Example 1 at an incident angle of 0 ° to 65 ° was measured. FIG. 3 shows transmittance spectra at incident angles of 0 °, 40 °, 50 °, and 60 °. Tables 7 and 8 show the results obtained from the transmittance spectrum of the optical filter according to Example 1 when the incident angle is 0 °. The “wavelength range having a transmittance of 78% or more” in Table 8 is a wavelength range showing a spectral transmittance of 78% or more at a wavelength of 400 nm to 600 nm. The “wavelength range with a transmittance of 1% or less” relating to the infrared region characteristics in Table 8 is a wavelength range showing a spectral transmittance of 1% or less at wavelengths of 700 nm to 1200 nm. The “wavelength range having a transmittance of 0.1% or less” relating to 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” relating to 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 is also true in Table 10, Table 12, Table 14, Table 16, Table 18, and Table 20. Furthermore, Table 11 and the results (incident angles: 0 ° to 65 °) of the optical filter according to Example 1 observed from the transmittance spectrum when the incident angles are 0 °, 30 ° to 65 ° (in increments of 5 °). Table 12 shows.

<Examples 2 to 15>
UV-IR absorbing compositions according to Examples 2 to 15 were prepared in the same manner as in Example 1 except that the addition amount of each compound was adjusted as shown in Table 1. Instead of the UV-IR absorbing composition according to Example 1, the UV-IR absorbing composition according to Examples 2 to 15 was used, and the thickness of the UV-IR absorbing layer was adjusted as shown in Table 1. Except for the above, optical filters according to Examples 2 to 15 were produced in the same manner as Example 1. Table 2 shows the content and content of each phosphonic acid based on the substance amount. Since the content of each phosphonic acid is obtained by rounding off the second decimal place, 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. FIG. 4 shows transmittance spectra at incident angles of 0 °, 40 °, 50 °, and 60 °. Tables 7 and 8 show the results obtained from the transmittance spectrum of the optical filter according to Example 2 when the incident angle is 0 °. Furthermore, Table 13 and Table 14 show the results observed from the transmittance spectrum of the optical filter according to Example 2 when the incident angle is 0 °, 30 ° to 65 ° (in increments of 5 °). Tables 7 and 8 show the results obtained from the transmittance spectrum of the optical filters according to Examples 3 to 15 when the incident angle is 0 °.

<Example 16>
Conducted using a dispenser in the range of 30 mm x 30 mm at the center of one main surface of a transparent glass substrate (product name: D263, manufactured by SCHOTT) made of borosilicate glass having dimensions of 76 mm x 76 mm x 0.21 mm The UV-IR absorbing composition according to Example 2 was applied to form a coating film having a predetermined thickness. In order to prevent the coating solution from flowing out when the UV-IR absorbing composition is applied to the transparent glass substrate, a frame having an opening corresponding to the coating range of the coating solution was placed on the transparent glass substrate to block the coating solution. . Next, the transparent glass substrate having an undried coating film was put in an oven and heat-treated at 85 ° C. for 6 hours to cure the coating film. Then, this coating film was peeled from the transparent glass substrate. The optical film according to Example 16 which is composed of only the UV-IR absorption layer by performing the 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. A filter was obtained. The measurement with the digital micrometer measured the thickness of only the light absorption layer. 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. FIG. 5 shows transmittance spectra at incident angles of 0 °, 40 °, 50 °, and 60 °. Tables 7 and 8 show the results obtained from the transmittance spectrum of the optical filter according to Example 16 when the incident angle is 0 °. Furthermore, Table 15 and Table 16 show the results observed from the transmittance spectrum of the optical filter according to Example 16 at an incident angle of 0 °, 30 ° to 65 ° (in increments of 5 °).

<Example 17>
Conducted using a dispenser in the range of 30 mm x 30 mm at the center of one main surface of a transparent glass substrate (product name: D263, manufactured by SCHOTT) made of borosilicate glass having dimensions of 76 mm x 76 mm x 0.21 mm The UV-IR absorbing composition according to Example 2 was applied to form a coating film having a thickness about half the thickness of the coating film in Example 2. In order to prevent the coating solution from flowing out when the UV-IR absorbing composition is applied to the transparent glass substrate, a frame having an opening corresponding to the coating range of the coating solution was placed on the transparent glass substrate to block the coating solution. . Next, the transparent glass substrate having an undried coating film was put in an oven and heat-treated at 85 ° C. for 6 hours to cure the coating film. Next, the UV-IR absorbing composition according to Example 2 was applied using a dispenser to a range of 30 mm × 30 mm in the center of the other main surface of the transparent glass substrate. About half the thickness of the coating film was formed. In order to prevent the coating solution from flowing out when the UV-IR absorbing composition is applied to the transparent glass substrate, a frame having an opening corresponding to the coating range of the coating solution was placed on the transparent glass substrate to block the coating solution. . Next, the transparent glass substrate having an undried coating film was put in an oven and heat-treated at 85 ° C. for 6 hours to cure the coating film. Next, in a constant temperature and humidity chamber set at a temperature of 85 ° C. and a relative humidity of 85%, the transparent glass substrate on which the above-mentioned coating film is formed on both main surfaces is placed for 20 hours to perform a humidification treatment. Thus, an optical filter according to Example 17 in which UV-IR absorption layers were formed on both sides was obtained. The total thickness of the UV-IR absorption layers formed on both surfaces of the transparent glass substrate was 193 μm. The transmittance spectrum of the optical filter according to Example 17 at an incident angle of 0 ° to 65 ° was measured. FIG. 6 shows transmittance spectra at incident angles of 0 °, 40 °, 50 °, and 60 °. Tables 7 and 8 show the results obtained from the transmittance spectrum of the optical filter according to Example 17 when the incident angle is 0 °. Tables 17 and 18 show the results obtained from the transmittance spectrum of the optical filter according to Example 17 when the incident angle is 0 °, 30 ° to 65 ° (in increments of 5 °).

<Example 18>
Instead of the transparent glass substrate used in Example 17, the same type of transparent glass substrate as that used in Example 17 having a thickness of 0.07 mm was used. An optical filter according to Example 18 in which UV-IR absorption layers were formed on both surfaces of a transparent glass substrate was produced. The total thickness of the UV-IR absorption layers formed on both surfaces 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. FIG. 7 shows transmittance spectra at incident angles of 0 °, 40 °, 50 °, and 60 °. Tables 7 and 8 show the results obtained from the transmittance spectrum of the optical filter according to Example 18 when the incident angle is 0 °. Tables 19 and 20 show the results observed from the transmittance spectrum of the optical filter according to Example 18 at an incident angle of 0 °, 30 ° to 65 ° (in increments of 5 °).

<Example 19>
Except that Prisurf A208F (Daiichi Kogyo Seiyaku Co., Ltd.) was used as the phosphate ester compound instead of Prisurf A208N, and the addition amount of each compound was adjusted as shown in Table 1, it was the same as in Example 1. Thus, a UV-IR absorbing composition according to Example 19 was prepared. 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, an optical filter according to Example 19 was produced. Tables 7 and 8 show the results obtained by measuring the transmittance spectrum of the optical filter according to Example 19 and viewing from the transmittance spectrum when the incident angle is 0 °.

<Example 20>
Instead of 4-bromophenylphosphonic acid, 4-fluorophenylphosphonic acid (C ₆ H ₄ FPO (OH) ₂ ) (manufactured by Tokyo Chemical Industry Co., Ltd.) was used, and the addition 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 Example 1 except for the above. 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, an 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 considering the transmittance spectrum when the incident angle is 0 °.

<Example 21>
Example 21 was carried out in the same manner 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 which concerns on was produced. This infrared absorption glass substrate contained copper and had the transmittance spectrum shown in FIG. 8A. The transmittance 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 transmittance spectrum at an incident angle of 0 °.

<Example 22 to Example 37>
Example 22 was carried out in the same manner as Example 2 except that the conditions of the humidification treatment of the dried coating film were changed as shown in Table 3 and the thickness of the UV-IR absorption layer was adjusted as shown in Table 3. Optical filters according to ˜37 were prepared. The transmittance spectrum of the optical filters according to Examples 22 to 24 at an incident angle of 0 ° was measured. The results are shown in FIGS. Tables 7 and 8 show the results obtained from the transmittance spectra of the optical filters according to Examples 22 to 24 at an incident angle of 0 °. The transmittance | permeability spectrum of the optical filter which concerns on Examples 25-37 is measured, and the result observed from the transmittance | permeability spectrum when an incident angle is 0 degree is shown in Table 7 and Table 8.

<Example 38>
Instead of the transparent glass substrate used in Example 2, a sapphire substrate having a thickness of 0.3 mm was used, and the thickness of the UV-IR absorption layer was adjusted to 168 μm. The optical filter which concerns on 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 obtained from the transmittance spectrum of the optical filter according to Example 38 at an incident angle of 0 °.

<Comparative Example 1>
Except that the addition amount of each compound was adjusted as shown in Tables 4 and 5, a liquid D (dispersion liquid of phenyl-based copper phosphonate fine particles) according to Comparative Example 1 was prepared in the same manner as in Example 1. . 2.200 g of silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-300) is added to the liquid D according to Comparative Example 1 and stirred for 30 minutes to obtain a UV-IR absorbing composition according to Comparative Example 1. It was. Example 1 except that the UV-IR absorbing composition according to Comparative Example 1 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 126 μm. In the same manner, an optical filter according to Comparative Example 1 was produced. Tables 9 and 10 show the results obtained by measuring the transmittance spectrum of the optical filter according to Comparative Example 1 and observing the transmittance spectrum when the incident angle is 0 °. In addition, 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 transmittance spectrum measurement result of the optical filter according to Comparative Example 1 when the incident angle was 0 °. The transmittance spectrum in the case is calculated, and the results that can be seen from this transmittance spectrum are shown as Comparative Calculation Example 1 in Table 9 and Table 10.

<Comparative example 2>
Except that the addition amount of each compound was adjusted as shown in Table 4 and Table 5, the D liquid (dispersion liquid of phenyl-based copper phosphonate fine particles) according to Comparative Example 2 was prepared in the same manner as in Example 1. did. 4.400 g of a silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-300) is added to the liquid D according to Comparative Example 2 and stirred for 30 minutes to obtain a UV-IR absorbing 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. The optical filter which concerns on the comparative example 2 was produced like Example 1 except having changed the conditions of the heat processing and humidification process for it as shown in Table 6. Tables 9 and 10 show the results of measuring the transmittance spectrum of the optical filter according to Comparative Example 2 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 2 when the incident angle was 0 °, the thickness of the UV-IR absorption layer of the optical filter according to Comparative Example 2 was changed to 347 μm. The transmittance spectrum in the case is calculated, and the results that can be seen from this transmittance spectrum are shown as Comparative Calculation Example 2 in Table 9 and Table 10.

<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 PRISURF A208F (Daiichi Kogyo Seiyaku Co., Ltd.) was added to the obtained copper acetate solution and stirred for 30 minutes to obtain Liquid 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. To the B-1 solution, 1.274 g of MTES (manufactured by Shin-Etsu Chemical Co., Ltd.) and 1.012 g of TEOS (special grade made by Kishida Chemical Co., Ltd.) were added and further stirred for 1 minute to obtain a B solution. Liquid B was added to liquid A while stirring liquid A, and the mixture was stirred at room temperature for 1 minute. Next, 25 g of toluene was added to this solution, followed by stirring at room temperature for 1 minute to obtain a liquid C. The solution C was put into a flask and heated with an oil bath (Tokyo Rika Kikai Co., Ltd., model: OSB-2100), and the solvent was removed by a rotary evaporator (Tokyo Rika Kikai Co., Ltd., model: N-1110SF). went. The set temperature of the oil bath was adjusted to 105 ° C. Thereafter, the liquid D according to Comparative Example 3 after the solvent removal treatment was taken out from the flask. Liquid D (dispersion liquid of copper phenylphosphonate fine particles) 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) is added to the liquid D according to Comparative Example 3 and stirred for 30 minutes to obtain a UV-IR absorbing composition according to Comparative Example 3. It was. Instead of the UV-IR absorbing composition according to Example 1, the thickness of the UV-IR absorbing layer is adjusted to 198 μm by using the UV-IR absorbing composition according to Comparative Example 3, and the coating film is cured. The optical filter which concerns on the comparative example 3 was produced like Example 1 except having adjusted the conditions of the heat processing for it as shown in Table 6. FIG. Tables 9 and 10 show the results obtained by measuring the transmittance spectrum of the optical filter according to Comparative Example 3 and viewing 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 is changed to 303 μm is calculated, The results that can be seen from the transmittance spectrum are shown in Table 9 and Table 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 Prisurf A208F, which is a phosphoric ester compound, was added to the obtained copper acetate solution and stirred for 30 minutes to obtain solution E. Further, 10 g of THF was added to 0.670 g of n-butylphosphonic acid (manufactured by Nippon Chemical Industry Co., Ltd.), and the mixture was stirred for 30 minutes to obtain a liquid F. While stirring E solution, F solution was added to E solution and stirred at room temperature for 1 minute. Next, 25 g of toluene was added to this solution, followed by stirring at room temperature for 1 minute to obtain a solution G. The solvent G was put into a flask and heated with an oil bath, and the solvent was removed by a rotary evaporator. The set temperature of the oil bath was adjusted to 105 ° C. Thereafter, the liquid H according to Comparative Example 4 after the solvent removal treatment was taken out from the flask. The 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 Shin-Etsu Chemical Co., Ltd., product name: KR-300) was added to the liquid H according to Comparative Example 4 and stirred for 30 minutes to obtain a UV-IR absorbing 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 is adjusted to 1002 μm, and the coating film is humidified. The optical filter which concerns on the comparative example 4 was produced like the comparative example 2 except not having performed. The transmittance spectrum of the optical filter according to Comparative Example 4 is measured, and the results that can be seen from the transmittance spectrum when the incident angle is 0 ° are shown in Tables 9 and 10. Further, based on the result of the transmittance spectrum measurement of the optical filter according to Comparative Example 4 when the incident angle is 0 °, the thickness of the UV-IR absorption layer of the optical filter according to Comparative Example 4 is changed to 1216 μm and 385 μm. The transmittance spectra in the case of the above are calculated, and the results that can be seen from these transmittance spectra are shown as Comparative Calculation Example 4-A and Comparative Calculation Example 4-B in Table 9 and Table 10, respectively.

<Comparative Example 5>
An optical filter according to Comparative Example 5 was produced in the same manner as Example 2 except that the thickness of the UV-IR absorbing layer was adjusted to 191 μm and the coating film was not subjected to humidification treatment. Tables 9 and 10 show the results obtained by measuring the transmittance spectrum of the optical filter according to Comparative Example 5 and observing the transmittance spectrum when the incident angle is 0 °. 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 transmittance spectrum measurement result when the incident angle of the optical filter according to Comparative Example 5 is 0 °. The transmittance spectrum is calculated, and the results that can be seen from this transmittance spectrum are shown in Table 9 and Table 10 as Comparative Calculation Example 5.

<Comparative Examples 6 and 7>
The optical filters according to Comparative Examples 6 and 7 were prepared in the same manner as in Example 2 except that the thickness of the UV-IR absorption layer was adjusted as shown in Table 9 and the humidification treatment of the coating film was adjusted as shown in Table 6. Produced. 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 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 when the incident angle of the optical filter according to Comparative Example 6 is 0 °. The transmittance spectrum is calculated, and the results that can be seen from the transmittance spectrum are shown in Table 9 and Table 10 as Comparative Calculation Example 6. Further, based on the result of the transmittance spectrum measurement of the optical filter according to Comparative Example 7 when the incident angle was 0 °, the thickness of the UV-IR absorption layer of the optical filter according to Comparative Example 7 was changed to 161 μm. The transmittance spectrum in this case is calculated, and the results that can be seen from this transmittance spectrum are shown as Comparative Calculation Example 7 in Table 9 and Table 10.

<Comparative Example 8>
In the same manner as in Comparative Example 1, a D liquid (a dispersion of phenyl-based copper phosphonate fine particles) according to Comparative Example 8 was prepared. Copper acetate monohydrate 0.225 g and THF 36 g were mixed and stirred for 3 hours to obtain a copper acetate solution. Next, 0.178 g of Prisurf A208F (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 solution E. Moreover, 10 g of THF was added to 0.134 g of n-butylphosphonic acid (manufactured by Nippon Chemical Industry Co., Ltd.), and the mixture was stirred for 30 minutes to obtain Liquid F. While stirring E solution, F solution was added to E solution and stirred at room temperature for 1 minute. Next, 25 g of toluene was added to this solution, followed by stirring at room temperature for 1 minute to obtain a solution G. The solvent G was put into a flask and heated with an oil bath, and the solvent was removed by a rotary evaporator. The set temperature of the oil bath was adjusted to 105 ° C. Thereafter, the liquid H according to Comparative Example 8 after the solvent removal 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 liquid according to Comparative Example 8 and stirred for 30 minutes to obtain a liquid I according to Comparative Example 8. The H liquid according to Comparative Example 8 was added to the I liquid according to Comparative Example 8 and stirred. However, aggregation of the copper phosphonate particles occurred, and a UV-IR absorbing composition having high transparency could not be obtained. .

<Comparative Example 9>
Attempts were made to prepare a UV-IR absorbing composition containing only n-butylphosphonic acid as the phosphonic acid and no alkoxysilane monomer in the amounts shown in Table 4, but agglomeration of the copper phosphonate particles occurred, which was high. A homogeneous UV-IR absorbing composition with transparency could not be obtained.

According to Table 7, the optical filter which concerns on Examples 1-38 had the optical performance of said (i)-(vii). Further, according to Table 11, Table 13, Table 15, Table 17, and Table 19, the optical filters according to Examples 1, 2, and 16 to 18 further have the optical performances (viii) to (xi) described above. Was. In addition, 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 optical performances (viii) to (xi) described above.

According to Table 9, the optical filter according to Comparative Example 1 did not have the optical performances (ii), (vi), and (vii), and did not have desired characteristics in the infrared region. . Further, according to the comparative calculation example 1, although the characteristics in the infrared region can be improved by increasing the thickness of the UV-IR absorption layer, the first IR cutoff wavelength is shortened, and the optical of (iv) It was suggested that performance could not be realized. Thus, 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 when the UV-IR absorbing compositions according to Comparative Examples 2 and 3 were used, the above ( It was suggested that an optical filter having all the optical performances 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) described above, and did not have 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
It was suggested that it is difficult to realize the optical performance of (i) above. Further, according to Comparative Calculation Example 4-B, although the optical performance of (i) is improved by reducing the thickness of the UV-IR absorption layer, the optical performance of (iii) and (v) is further improved. It was suggested that the maximum transmittance at wavelengths of 750 to 1080 nm also increased. For this reason, even if it used the UV-IR absorptive composition concerning comparative example 4, it was suggested that the optical filter which has all the optical performances of the above (i)-(v) cannot be produced.

According to Table 9, the optical filter according to Comparative Example 5 did not have the optical performances (i) and (iv). According to Comparative Calculation Example 5, by reducing the thickness of the UV-IR absorption layer, the average transmittance at a wavelength of 450 to 600 nm is increased, but the IR cutoff wavelength is hardly changed, and the maximum transmission at a wavelength of 750 to 1080 nm is achieved. It was suggested that the rate also increased. For this reason, it was suggested that the method for producing an optical filter according to Comparative Example 5 cannot produce an optical filter having all the optical performances (i) to (v). The hydrolysis and condensation polymerization of the alkoxysilane monomer contained in the UV-IR absorbing composition is accelerated by the humidification treatment, and in addition to the curing of the UV-IR absorption layer, the humidification treatment is added to 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 (iv). According to Comparative Calculation Example 6, it was suggested that, by reducing the thickness of the UV-IR absorption layer, the IR cutoff wavelength increases, but the maximum transmittance at wavelengths of 750 to 1080 nm also increases. For this reason, it was suggested that the optical filter production method according to Comparative Example 6 cannot produce an optical filter having all the optical performances (i) to (v). In particular, it was suggested that the humidification conditions 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 (i) and (iv). According to Comparative Calculation Example 7, it was suggested that, by reducing the thickness of the UV-IR absorption layer, the IR cutoff wavelength increases, but the maximum transmittance at wavelengths of 750 to 1080 nm also increases. For this reason, it was suggested that the optical filter production method according to Comparative Example 7 cannot produce an optical filter having all the optical performances (i) to (v). In particular, it was suggested that the conditions for the humidification treatment in Comparative Example 7 were not sufficient.

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

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

  As shown in Table 2, in 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 UV-IR absorbing composition according to Example 13 has the lowest content of 4-bromophenylphosphonic acid. 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 greater the UV cutoff wavelength. This suggested 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 absorptive composition is prepared similarly to the UV-IR absorptive composition according to Example 2, as shown in Tables 7 to 10, the optical filters according to these Examples and Comparative Examples are as follows. The optical filter had optical performance different from that of the optical filter according to Example 2. As described above, humidification treatment is carried out for the purpose of promoting hydrolysis and condensation polymerization of alkoxysilane contained in the UV-IR absorbing composition. In the optical filter according to the comparative example, a difference occurred 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, although the UV cutoff wavelength can be adjusted by changing the thickness of the UV-IR absorption layer, according to the method for producing an optical filter according to Comparative Examples 5 to 7 It is difficult to keep the IR cutoff wavelength within a desired range while satisfying other optical performances of (i) to (xi). Therefore, the water vapor amount (exposure water vapor amount) in the environment where the article to be treated is exposed in the humidification treatment of each example and some 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 Tetens approximation: e = 6.11 × 10 ^{(7.5 t / (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 determined from the equation ρv = 217 × e × φ / (t + 273.15). The amount of water vapor x time [mol / m ³ · hour] was defined as the amount of water vapor exposed. As shown in Tables 3 and 6, it was suggested that when the temperature is 60 ° C. or higher in the humidification treatment, good optical performance can be obtained when the relative humidity is 70% or more and the treatment time is 1 hour or more. This treatment condition corresponds to an exposure water vapor amount condition of 5.0 [mol / m ³ · hour] or more, but when the temperature in the humidification treatment is as low as 40 ° C. and the relative humidity is 70%, and humidification It was suggested that even when the processing temperature is 60 ° C. and the relative humidity is as low as 40%, good optical performance can be obtained by extending the processing time to the same amount of exposed water vapor. From these results, it was suggested that it is desirable to perform humidification 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 providing good optical performance to the optical filter.

DESCRIPTION OF SYMBOLS 1a-1f Optical filter 2 Lens system 3 Low pass filter 4 Image pick-up element 5 Circuit board 7 Optical filter support housing | casing 8 Optical system housing | casing 10 UV-IR absorption layer 20 Transparent dielectric substrate 30 Antireflection film 40 Reflective film 100 Camera module

The present invention relates to a UV-IR absorbing composition .

Although the near-infrared absorption filter described in Patent Document 1 can effectively absorb light at wavelengths of 800 nm to 1200 nm, it is difficult to say that it has desirable light absorption characteristics at wavelengths of 350 nm to 400 nm and wavelengths of 650 nm to 800 nm. . Therefore, the present invention provides a composition for an optical filter that can exhibit desired optical performance, which is difficult to achieve with only the near-infrared absorption filter described in Patent Document 1, with a simple configuration.

The present invention
A first phosphonic acid having an aryl group;
A second phosphonic acid having an alkyl group;
Containing copper ions,
The ratio of the amount of the first phosphonic acid to the amount of the second phosphonic acid is 1.8 to 5.4.
A UV-IR absorbing composition is provided.

The optical filter manufactured using the above UV-IR absorbing composition can exhibit desired optical performance with a simple configuration.

Claims (12)

It has a UV-IR absorption layer that can absorb infrared and ultraviolet rays,
When light having a wavelength of 300 nm to 1200 nm is incident at an incident angle of 0 °,
(I) having an average transmittance of 78% or more at a wavelength of 450 nm to 600 nm;
(Ii) having a spectral transmittance of 1% or less at wavelengths of 750 nm to 1080 nm,
(Iii) having a spectral transmittance of 1% or less at a wavelength of 300 nm to 350 nm,
(Iv) The first IR cut-off wavelength having a spectral transmittance that decreases with an increase in wavelength at a wavelength of 600 nm to 750 nm and a spectral transmittance of 50% at a wavelength of 600 nm to 750 nm is within the wavelength range of 620 nm to 680 nm. Exists,
(V) The first UV cutoff wavelength having a spectral transmittance that increases with an increase in wavelength at a wavelength of 350 nm to 450 nm and a spectral transmittance of 50% at a wavelength of 350 nm to 450 nm is in the range of a wavelength of 380 nm to 430 nm. Exist,
Optical filter. When light having a wavelength of 300 nm to 1200 nm is incident at an incident angle of 0 °,
(Vi) having a spectral transmittance of 3% or less at a wavelength of 1000 to 1100 nm,
The optical filter according to claim 1. When light having a wavelength of 300 nm to 1200 nm is incident at an incident angle of 0 °,
(Vii) having a spectral transmittance of 15% or less at a wavelength of 1100 to 1200 nm,
The optical filter according to claim 1 or 2.   The difference between the second IR cutoff wavelength at which the spectral transmittance is 50% at a wavelength of 600 nm to 750 nm when light having a wavelength of 300 nm to 1200 nm is incident at an incident angle of 40 °, and the first IR cutoff wavelength The optical filter according to any one of claims 1 to 3, wherein an absolute value is 10 nm or less.   The difference between the third IR cutoff wavelength at which the spectral transmittance is 50% at a wavelength of 600 nm to 750 nm when light having a wavelength of 300 nm to 1200 nm is incident at an incident angle of 50 ° and the first IR cutoff wavelength The optical filter of any one of Claims 1-4 whose absolute value is 15 nm or less.   The difference between the second UV cutoff wavelength at which spectral transmittance is 50% 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 ° and the first UV cutoff wavelength The optical filter according to any one of claims 1 to 5, wherein an absolute value is 10 nm or less.   The difference between the third UV cutoff wavelength at which the spectral transmittance is 50% 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 The optical filter of any one of Claims 1-6 whose absolute value is 15 nm or less.   The optical filter according to claim 1, wherein the UV-IR absorption layer includes a UV-IR absorber formed by phosphonic acid and copper ions.   The optical filter according to claim 8, wherein the phosphonic acid includes a first phosphonic acid having an aryl group. The optical filter according to claim 9, wherein the first phosphonic acid has a halogenated phenyl group in which at least one hydrogen atom in the phenyl group is substituted with a halogen atom.   The optical filter according to claim 9 or 10, wherein the phosphonic acid further includes a second phosphonic acid having an alkyl group.   The optical filter according to claim 1, wherein the UV-IR absorption layer is formed as a single layer.

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