Light-absorbing composition, light absorber, and apparatus

Abstract

The present invention provides a light absorber that exhibits high transmittance in the visible light region, particularly in the red band, and can effectively block near-infrared light. [Solution] The transmission spectrum of the light absorber 10 at an incident angle of 0° satisfies the following conditions: (I) The average transmittance in the wavelength range of 450nm to 600nm is 75% or more. (II) The first wavelength at which the transmittance is 50% in the wavelength range of 350nm to 450nm is between 380nm and 440nm. (III) The second wavelength at which the transmittance is 50% in the wavelength range of 650nm to 750nm is between 680nm and 740nm. (IV) The maximum transmittance in the wavelength range of 350nm to 370nm is 1% or less. (V) The maximum transmittance in the wavelength range of 800nm ​​to 900nm is 5% or less. (VI) The maximum transmittance in the wavelength range of 1100nm to 1200nm is 5% or less.

Description

[Technical Field]

[0001] The present invention relates to a light absorber, an article with a light absorber, an imaging device, and a light-absorbing composition. [Background technology]

[0002] In imaging devices using solid-state image sensors such as CCDs (Charge Coupled Devices) or CMOSs ​​(Complementary Metal Oxide Semiconductors), various optical filters are placed in front of the solid-state image sensor to obtain images with good color reproduction. Generally, solid-state image sensors have spectral sensitivity over a wide wavelength range from the ultraviolet region to the infrared region. On the other hand, human visual sensitivity exists only in the visible light region. For this reason, in order to bring the spectral sensitivity of the solid-state image sensor in an imaging device closer to human visual sensitivity, a technique is known in which an optical filter that blocks some infrared or ultraviolet light is placed in front of the solid-state image sensor.

[0003] Traditionally, optical filters typically used dielectric multilayer films to block infrared or ultraviolet light through light reflection. However, in recent years, optical filters equipped with films containing light-absorbing agents have attracted attention. Because the transmittance characteristics of optical filters with films containing light-absorbing agents are less affected by the angle of incidence, good images with minimal color changes can be obtained even when light is incident on the optical filter at an oblique angle in the imaging device. Furthermore, light-absorbing optical filters that do not use light-reflective films can suppress the occurrence of ghosting and flare caused by multiple reflections by light-reflective films, making it easier to obtain good images in backlit conditions and when shooting night scenes. In addition, optical filters with films containing light-absorbing agents are also advantageous in terms of miniaturization and thinning of imaging devices.

[0004] As such light absorbers, those formed from phosphonic acid and copper ions are known. For example, Patent Document 1 describes an optical filter comprising a light-absorbing layer containing a light absorber formed from phosphonic acid having a phenyl group or a halogenated phenyl group (phenyl-based phosphonic acid) and copper ions.

[0005] Furthermore, Patent Document 2 describes an optical filter equipped with a UV-IR absorbing layer capable of absorbing infrared and ultraviolet rays. The UV-IR absorbing layer contains a UV-IR absorbent formed from phosphonic acid and copper ions. To ensure that the optical filter satisfies predetermined optical properties, the UV-IR absorbing composition contains, for example, phenyl phosphonic acid and phosphonic acid having an alkyl group or a halogenated alkyl group (alkyl phosphonic acid).

[0006] Furthermore, Patent Document 3 describes an infrared cut filter comprising an organic dye-containing layer and a copper phosphonate-containing layer.

[0007] On the other hand, Patent Document 4 describes an optical filter comprising an absorption layer, a reflective layer, and a transparent substrate, which satisfies predetermined requirements in the spectral transmittance curve at an incident angle of 0°. The absorption layer contains a near-infrared absorbing dye such as a squarylium dye. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Patent No. 6339755 [Patent Document 2] Patent No. 6232161 [Patent Document 3] Patent No. 6281023 [Patent Document 4] International Publication No. 2020 / 004641 [Overview of the project] [Problems that the invention aims to solve]

[0009] In the optical filters described in Patent Documents 1 to 3, the cutoff wavelength near the infrared region is adjusted to the range of 600 to 680 nm. While this is advantageous from the viewpoint of effectively shielding infrared light, it is not particularly advantageous from the viewpoint of increasing transmittance in the red band. On the other hand, in the optical filter described in Patent Document 4, although the wavelength at which transmittance is 50% near the infrared region is 680 nm or higher, a reflective layer is required, and the reflective layer must compensate for the insufficient shielding of light by the absorption layer. For this reason, the optical filter described in Patent Document 4 requires a complicated process for forming the reflective layer.

[0010] Therefore, the present invention provides a light absorber that tends to have high transmittance in the visible light region, particularly in the red band, and that can effectively block near-infrared light. [Means for solving the problem]

[0011] The present invention The present invention provides a light absorber whose transmission spectrum at an incident angle of 0° satisfies the following conditions (I), (II), (III), (IV), (V), and (VI). (I) The average transmittance in the wavelength range of 450 nm to 600 nm is 75% or higher. (II) The first wavelength at which the transmittance is 50% in the wavelength range of 350 nm to 450 nm is between 380 nm and 440 nm. (III) The second wavelength at which the transmittance is 50% in the wavelength range of 650 nm to 750 nm is between 680 nm and 740 nm. (IV) The maximum transmittance in the wavelength range of 350 nm to 370 nm is 1% or less. (V) The maximum transmittance in the wavelength range of 800nm ​​to 900nm is 5% or less. (VI) The maximum transmittance in the wavelength range of 1100 nm to 1200 nm is 5% or less.

[0012] Furthermore, the present invention is Goods and, A light absorber formed on a part of the surface of the article, comprising: We provide articles equipped with light absorbers.

[0013] Furthermore, the present invention is A light-absorbing composition, The present invention provides a light-absorbing composition in which the transmission spectrum of a light absorber obtained by curing the light-absorbing composition satisfies the following conditions (i), (ii), (iii), (iv), (v), and (vi) at an incident angle of 0°. (i) The average transmittance in the wavelength range of 450 nm to 600 nm is 75% or higher. (ii) The first wavelength at which the transmittance is 50% in the wavelength range of 350 nm to 450 nm is between 380 nm and 440 nm. (iii) The second wavelength at which the transmittance is 50% in the wavelength range of 650 nm to 750 nm is between 680 nm and 740 nm. (iv) The maximum transmittance in the wavelength range of 350 nm to 370 nm is 1% or less. (v) The maximum transmittance in the wavelength range of 800 nm to 900 nm is 5% or less. (vi) The maximum transmittance in the wavelength range of 1100 nm to 1200 nm is 5% or less. [Effects of the Invention]

[0014] In the above-described light absorber, the transmittance tends to be high in the visible light region, particularly in the red band. In addition, the above-described light absorber can effectively block near-infrared light. [Brief explanation of the drawing]

[0015] [Figure 1A] Figure 1A is a cross-sectional view showing an example of a light absorber according to the present invention. [Figure 1B] Figure 1B is a cross-sectional view showing an example of an article with a light absorber according to the present invention. [Figure 1C] Figure 1C is a cross-sectional view showing another example of an article with a light absorber according to the present invention. [Figure 1D]Figure 1D is a cross-sectional view showing an example of an optical component equipped with a light absorber according to the present invention. [Figure 2] Figure 2 shows an example of an imaging device according to the present invention. [Figure 3A] Figure 3A shows the transmission spectrum of the optical filter according to Example 1. [Figure 3B] Figure 3B shows the transmission spectrum of the optical filter according to Example 1. [Figure 3C] Figure 3C shows the transmission spectrum of the optical filter according to Example 1. [Figure 4A] Figure 4A shows the transmission spectrum of the optical filter according to Example 2. [Figure 4B] Figure 4B shows the transmission spectrum of the optical filter according to Example 2. [Figure 4C] Figure 4C shows the transmission spectrum of the optical filter according to Example 2. [Figure 5A] Figure 5A shows the transmission spectrum of the optical filter according to Example 3. [Figure 5B] Figure 5B shows the transmission spectrum of the optical filter according to Example 3. [Figure 5C] Figure 5C shows the transmission spectrum of the optical filter according to Example 3. [Figure 6] Figure 6 shows the transmission spectrum of the optical filter according to Comparative Example 1. [Figure 7] Figure 7 shows the transmission spectrum of the optical filter according to Comparative Example 2. [Figure 8] Figure 8 shows the transmission spectrum of the optical filter according to Comparative Example 3. [Figure 9] Figure 9 shows the transmission spectrum of the optical filter according to Comparative Example 4. [Figure 10] Figure 10 shows the optical filter transmission spectrum according to Example 9. [Modes for carrying out the invention]

[0016] It is conceivable to mount cameras equipped with CMOS sensors, etc., on vehicles as part of an in-vehicle system. In addition, such cameras could be used in driving devices, mobility devices, and transport devices for drones and autonomous robots. In this case, the camera primarily acquires information such as captured images of the external situation, and this acquired information can support the operation of the driver, operator, or control system for autonomous operation. In this case, from the viewpoint of improving the accuracy of external environment recognition, it is advantageous for the camera to be equipped with an optical filter that has high transmittance in the visible light range and can effectively block infrared rays. The visible light range is the range of wavelengths in electromagnetic waves that humans can perceive as light, with the lower limit of this wavelength range being 360-400 nm and the upper limit being 760-830 nm. Furthermore, according to the Japanese Industrial Standard (JIS) Z 8120:2001, the visible light range can also be in the range of 380-780 nm. Infrared rays, especially near-infrared rays (NIR), are defined as electromagnetic waves with wavelengths in the range up to approximately 1400 nm, which is beyond the wavelength range of the visible light range.

[0017] In traffic signals and road signs, indicators related to danger or safety are sometimes displayed in red. For example, in addition to red lights, regulatory signs such as "no entry," "stop," and "slow down" on traffic signs (road signs) fall into this category. In the transmission spectrum of an optical filter, high transmittance in the wavelength range corresponding to red is important for accurately recognizing surrounding objects, including the red lights and regulatory signs mentioned above. The red color displayed in regulatory signs, etc., exhibits high reflectance in a wavelength range with a lower limit of 580-620 nm and an upper limit exceeding approximately 780 nm, depending on the specifications of the material such as retroreflective sheet. Assuming the upper limit of the visible light wavelength range is 780 nm, it is advantageous for the transmission spectrum of an optical filter to have high transmittance in the wavelength range of 580-780 nm, or high transmittance in the wavelength range of 620-760 nm, or high transmittance in the wavelength range of 620-750 nm.

[0018] In addition, the ability of the optical filter to effectively block infrared radiation is important to suppress problems such as the camera being unable to obtain good images due to the influence of infrared sensing in vehicles, mobile devices, or transport devices traveling in the vicinity. It is understood that the characteristics of the optical filter described in Patent Document 4 have been adjusted from this perspective. On the other hand, the optical filter described in Patent Document 4 has a reflective layer in addition to an absorbing layer. For this reason, the inventors have gone through considerable trial and error to develop a technology that can achieve high transmittance in the red band and effectively block near-infrared radiation without using a reflective layer. As a result, the present invention has finally been completed.

[0019] In this specification, unless otherwise specified, the visible light range or visible light region is defined as the wavelength range of 380 to 780 nm, and the red band is defined as the wavelength range of 580 to 780 nm or a portion of that range. Unless otherwise specified, infrared radiation is defined as light (electromagnetic waves) with a wavelength greater than 780 nm, the upper limit of the visible light range, and belonging to the range up to 1400 nm, and corresponds to near-infrared radiation (NIR). Ultraviolet radiation is defined as light (electromagnetic waves) belonging to the wavelength range from 280 nm to 380 nm, the lower limit of the visible light range, and corresponds to UV-A and a portion of UV-B.

[0020] The following describes embodiments of the present invention. Note that the following description is illustrative and not limited to the embodiments described below.

[0021] (Light-absorbing material) Figure 1A is a cross-sectional view showing the light absorber 10. The transmission spectrum of the light absorber 10 at an incident angle of 0° satisfies the following conditions (I), (II), (III), (IV), (V), and (VI). (I) Average value T of transmittance in the wavelength range of 450 nm to 600 nm A 0(450-600) The percentage is over 75%. (II) The first wavelength λ in which the transmittance is 50% in the wavelength range of 350 nm to 450 nm 50 0(UV)is 380 nm or more and 440 nm or less. (III) A second wavelength λ at which the transmittance is 50% in the wavelength range of 650 nm to 750 nm 50 0(IR) is 680 nm or more and 740 nm or less. (IV) The maximum value T of the transmittance in the wavelength range of 350 nm to 370 nm M 0(350-370) is 1% or less. (V) The maximum value T of the transmittance in the wavelength range of 800 nm to 900 nm M 0(800-900) is 5% or less. (VI) The maximum value T of the transmittance in the wavelength range of 1100 nm to 1200 nm M 0(1100-1200) is 5% or less.

[0022] (I), (II), and (III) conditions are satisfied, so the transmittance in the visible light region tends to be high. In particular, when (III) condition is satisfied, the transmittance in the red band of the light absorber 10 tends to be high. In addition, when (V) and (VI) conditions are satisfied, the light absorber 10 can shield infrared rays well. Also, when (IV) condition is satisfied, the light absorber 10 can shield ultraviolet rays well.

[0023] (I) Regarding the condition, the average value T A 0(450-600) is preferably 80% or more, more preferably 85% or more. In addition, the transmittance spectrum of the light absorber 10 at an incident angle of 0° preferably further satisfies the following condition (Ia). (Ia) The average value T of the transmittance in the wavelength range of 650 nm to 670 nm A 0(650-670) is 70% or more.

[0024] (Ia) Regarding the condition, the average value T A 0(650-670) is preferably 72% or more, more preferably 74% or more.

[0025] Regarding condition (II), the first wavelength λ 50 0(UV) The wavelength is preferably between 385 nm and 420 nm, and more preferably between 390 nm and 410 nm.

[0026] Regarding condition (III), the second wavelength λ 50 0(IR) Preferably, the wavelength is greater than 680 nm and less than or equal to 740 nm, more preferably between 685 nm and 730 nm, and even more preferably between 690 nm and 720 nm.

[0027] Regarding condition (IV), the maximum value T M 0(350-370) The percentage should preferably be 0.5% or less.

[0028] Regarding the condition (V), the maximum value T M 0(800-900) Ideally, this should be 3% or less.

[0029] Regarding the condition in (VI), the maximum value T M 0(1100-1200) Ideally, this should be 3% or less.

[0030] The transmission spectrum of the light absorber 10 at an incident angle of 0° further satisfies, for example, the following condition (VII). This makes it more likely that the transmittance of the light absorber 10 in the red band will be higher. (VII) Transmittance T at a wavelength of 750 nm 0(750) The percentage is 7% or more.

[0031] Regarding the conditions of (VII), transmittance T 0(750) The percentage is preferably 10% or more, and more preferably 15% or more.

[0032] The transmission spectrum of the light absorber 10 at an incident angle of 0° further satisfies, for example, the following condition (VIII). This makes it more likely that the transmittance of the light absorber 10 in the red band will be higher. (VIII) Transmittance T at a wavelength of 780 nm 0(780) The percentage is 3% or more.

[0033] Regarding the conditions of (VIII), transmittance T 0(780) The percentage is preferably 4% or higher, and more preferably 5% or higher.

[0034] The transmission spectrum of the light absorber 10 at an incident angle of 55° is, for example, the third wavelength λ at which the transmittance is 50% in the wavelength range of 350 nm to 450 nm. 50 55(UV) It has the third wavelength λ 50 55(UV) and the first wavelength λ 50 0(UV) The absolute value of the difference between Δλ 50 0 / 55(UV) For example, it is 12 nm or less. This makes it easier to reduce the incident angle dependence of the transmission spectrum of the light absorber 10. For this reason, for example, color changes can be suppressed in the central and peripheral parts of an image obtained by an imaging device equipped with the light absorber 10. In addition, color changes can be suppressed in images of subjects within the field of view that can be captured by the imaging device equipped with the light absorber 10. Absolute value Δλ 50 0 / 55(UV) The wavelength is preferably 10 nm or less, more preferably 8 nm or less, and even more preferably 6 nm or less.

[0035] The transmission spectrum of the light absorber 10 at an incident angle of 55° is, for example, the fourth wavelength λ at which the transmittance is 50% in the wavelength range of 650 nm to 750 nm. 50 55(IR) It has the fourth wavelength λ 50 55(IR) and the second wavelength λ 50 0(IR) The absolute value of the difference between Δλ 50 0 / 55(IR) For example, it is 24 nm or less. This makes it easier to reduce the incident angle dependence of the transmission spectrum of the light absorber 10. For this reason, for example, color changes can be suppressed in the central and peripheral parts of an image obtained by an imaging device equipped with the light absorber 10. In addition, color changes can be suppressed in images of subjects within the field of view that can be captured by the imaging device equipped with the light absorber 10. Absolute value Δλ 500 / 55(IR) The wavelength is preferably 20 nm or less, more preferably 18 nm or less, and even more preferably 16 nm or less.

[0036] The transmission spectrum of the light absorber 10 at an incident angle of 45° is, for example, the wavelength λ at which the transmittance is 50% in the wavelength range of 350 nm to 450 nm. 50 45(UV) It has a wavelength λ 50 45(UV) and the first wavelength λ 50 0(UV) The absolute value of the difference between Δλ 50 0 / 45(UV) For example, it is 10 nm or less, preferably 8 nm or less, and more preferably 5 nm or less.

[0037] The transmission spectrum of the light absorber 10 at an incident angle of 35° is, for example, the wavelength λ at which the transmittance is 50% in the wavelength range of 350 nm to 450 nm. 50 35(UV) It has a wavelength λ 50 35(UV) and the first wavelength λ 50 0(UV) The absolute value of the difference between Δλ 50 0 / 35(UV) For example, the wavelength is 8 nm or less, preferably 6 nm or less, and more preferably 4 nm or less.

[0038] The transmission spectrum of the light absorber 10 at an incident angle of 45° is, for example, the wavelength λ at which the transmittance is 50% in the wavelength range of 650 nm to 750 nm. 50 45(IR) It has a wavelength λ 50 45(IR) and the second wavelength λ 50 0(IR) The absolute value of the difference between Δλ 50 0 / 45(IR) For example, the wavelength is 18 nm or less, preferably 16 nm or less, and more preferably 12 nm or less.

[0039] The transmission spectrum of the light absorber 10 at an incident angle of 35° is, for example, the wavelength λ at which the transmittance is 50% in the wavelength range of 650 nm to 750 nm.50 35(IR) It has a wavelength λ 50 35(IR) and the second wavelength λ 50 0(IR) The absolute value of the difference between Δλ 50 0 / 35(IR) For example, the wavelength is 12 nm or less, preferably 10 nm or less, and more preferably 8 nm or less.

[0040] The light absorber 10 typically contains a predetermined light absorber. The light absorber contained in the light absorber 10 is not limited to a specific substance, as long as the transmission spectrum of the light absorber 10 at an incident angle of 0° satisfies conditions (I) to (VI). The light absorber 10 may contain, for example, a light-absorbing compound containing phosphonic acid and a copper component as a light absorber, and may also contain an ultraviolet absorber that absorbs at least a portion of ultraviolet light. The light absorber 10 is in a solid state, such as a film or a membrane formed on a predetermined object, and the light absorber 10 can be produced by curing a liquid light-absorbing composition that is its precursor. If the light absorber 10 contains a compound that can exhibit a predetermined function, the light-absorbing composition that is its precursor may naturally also contain that compound or its precursor.

[0041] (Phosphonic acid) The phosphonic acid in the light-absorbing compound contained in the light-absorbing material 10 or the light-absorbing composition is not limited to a specific phosphonic acid, as long as the transmission spectrum of the light-absorbing material 10 at an incident angle of 0° satisfies conditions (I) to (VI). The phosphonic acid is, for example, represented by the following formula (a). In formula (a), R1 is an alkyl group or a halogenated alkyl group in which at least one hydrogen atom in the alkyl group is substituted with a halogen atom. In this case, the transmission band of the light-absorbing material 10 tends to extend to a wavelength of around 700 nm, and the light-absorbing material 10 tends to have the desired transmittance characteristics.

[0042] [ka]

[0043] Phosphonic acids include, for example, methylphosphonic acid, ethylphosphonic acid, n-(n-)propylphosphonic acid, isopropylphosphonic acid, n-(n-)butylphosphonic acid, isobutylphosphonic acid, sec-butylphosphonic acid, tert-butylphosphonic acid, or bromomethylphosphonic acid.

[0044] (Copper content) The copper component in the light-absorbing compound contained in the light absorber 10 or light-absorbing composition is a concept that includes copper ions, copper complexes, and compounds containing copper. The copper component may have desirable absorption characteristics for a portion of the light belonging to the near-infrared region and high transmittance of light in the visible light region with wavelengths ranging from 450 nm to 680 nm. Specifically, excellent near-infrared absorption characteristics are exhibited by selectively absorbing light of wavelengths belonging to the near-infrared region corresponding to this energy through electron transitions in the d orbitals of divalent copper ions. In particular, divalent copper ions may be mixed with phosphonic acid in the form of a copper salt, and the phosphonic acid may coordinate with the copper ions to form a copper complex (copper salt).

[0045] The sources of copper components used for coordination of phosphonic acid are not limited to these, but may include anhydrous or hydrated copper salts of organic acids such as copper acetate, copper benzoate, copper pyrophosphate, and copper stearate, or mixtures thereof. These copper salts may be used individually, or multiple copper salts or mixtures thereof may be used.

[0046] The copper and phosphonic acid content in the light absorber 10 is not limited to any specific value. The ratio of phosphonic acid content to copper content in the light absorber 10 is, for example, 0.3 to 1.5 on a molar basis. The ratio of phosphonic acid content to copper content in the light absorber 10 may preferably be 0.4 to 1.4, more preferably 0.6 to 1.2, and even more preferably 0.8 to 1.1.

[0047] (Phosphate ester) The light absorber 10 or light-absorbing composition may further contain, for example, a phosphate ester compound. The phosphate ester facilitates the proper dispersion of the light-absorbing compound in the light absorber 10. The phosphate ester may function as a dispersant for the light-absorbing compound, or a portion of it may react with a metal component to form a compound. For example, the phosphate ester may coordinate with the light-absorbing compound or react with the compound, or partially form a complex with a copper component. As long as the light absorber 10 satisfies predetermined transmission spectrum conditions, the compound containing the phosphate ester and copper component may also absorb light of certain wavelengths. The phosphate ester may be substantially omitted in the light-absorbing composition, which is a precursor of the light absorber 10, as long as the light-absorbing substance containing at least phosphonic acid and a copper component is suitably dispersed. Furthermore, if, for example, an alkoxysilane monomer described later is included in the light-absorbing composition to impart dispersion functionality, the amount of phosphate ester added can be reduced.

[0048] Phosphate esters are not limited to specific phosphate esters or their compounds. Phosphate esters, for example, have a polyoxyalkyl group. Examples of such phosphate esters include Prisurf A208N: polyoxyethylene alkyl (C12, C13) ether phosphate ester, Prisurf A208F: polyoxyethylene alkyl (C8) ether phosphate ester, Prisurf A208B: polyoxyethylene lauryl ether phosphate ester, Prisurf A219B: polyoxyethylene lauryl ether phosphate ester, Prisurf AL: polyoxyethylene styrene-phenyl ether phosphate ester, Prisurf A212C: polyoxyethylene tridecyl ether phosphate ester, or Prisurf A215C: polyoxyethylene tridecyl ether phosphate ester. All of these are products manufactured by Daiichi Kogyo Seiyaku Co., Ltd. In addition, examples of phosphate esters include 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. These are all products manufactured by Nikko Chemicals Co., Ltd. These phosphate ester compounds may be used individually or in combination.

[0049] The content of phosphonic acid and phosphate ester in the light absorber 10 is not limited to any specific value. The ratio of the phosphonic acid content to the phosphate ester content in the light absorber 10 is, for example, 0.6 to 1.6 by mass. This suppresses the hydrolysis of the phosphate ester even when the light absorber 10 comes into contact with water vapor, making the light absorber 10 more likely to have good weather resistance. The ratio of the phosphonic acid content to the phosphate ester content in the light absorber 10 may preferably be 0.7 to 1.5, and more preferably 0.8 to 1.4.

[0050] Furthermore, the ratio of the copper content to the phosphorus content in the light absorber 10 is not limited to a specific value. The ratio of the copper content to the phosphorus content in the light absorber 10 may be, for example, 1.0 to 3.0 by mass, and preferably 1.5 to 2.0. The phosphorus component may be derived from phosphonic acid contained in the light absorber 10 or its precursor light-absorbing composition, or from phosphonic acid and phosphate ester contained in the light absorber 10 or its precursor light-absorbing composition, or it may also be contained in other additives.

[0051] (Alkoxysilane or its hydrolysate) The light absorber 10 or light-absorbing composition may further contain, for example, an alkoxysilane. The alkoxysilane includes alkoxysilane monomers or hydrolyzed portions thereof. The presence of alkoxysilane prevents the particles of the light absorber from aggregating, so that even if the content of the phosphate ester mentioned above is reduced, the light absorber is well dispersed in the light-absorbing composition or the light absorber obtained by curing it. Preferably, when manufacturing a light absorber or light-absorbing filter using the light-absorbing composition, by processing so that the hydrolysis and condensation polymerization reactions of the alkoxysilane occur sufficiently, siloxane bonds (-Si-O-Si-) are formed, and the light absorber has good moisture resistance. In addition, the light absorber has good heat resistance. This is because siloxane bonds have higher bond energy and are chemically stable than bonds such as -CC- bonds and -CO- bonds, and therefore have excellent heat resistance and moisture resistance.

[0052] Furthermore, if the light-absorbing composition contains alkoxysilane, when curing the light-absorbing composition to produce a light absorber, a so-called humidification treatment may be performed, in which the composition is exposed to a relatively high-humidity atmosphere for a certain period of time. It is believed that the water component in the atmosphere promotes the hydrolysis of the alkoxysilane contained in the light-absorbing composition or light absorber, thereby promoting the formation of siloxane bonds. In addition, the humidification treatment allows for the formation of a hard, dense light absorber 10 without aggregation of the fine particles containing the light absorber.

[0053] The alkoxysilane is not limited to a specific alkoxysilane, as long as it can form a hydrolyzable condensate compound having a siloxane bond in the light absorber 10 through hydrolysis and condensate polymerization reactions. The alkoxysilane may be a monomer such as tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, or 3-glycidoxypropylmethyldiethoxysilane, or a dimer or oligomer in which some of these are bonded.

[0054] (curable resin) The light absorber 10 or light-absorbing composition further contains, for example, a curable resin. The resin is required to be capable of dispersing or dissolving and retaining the light-absorbing compound containing the phosphonic acid and copper component described above. Furthermore, it is desirable that the resin is liquid in an uncured or unreacted state and capable of dispersing or dissolving the light-absorbing compound containing the phosphonic acid and copper component described above. Moreover, it is desirable that the uncured liquid resin containing the light-absorbing compound can be applied to any object by coating methods such as spin coating, spraying, dipping, and dispensing to form a coating film. The object on which the coating film is formed is a substrate having any surface, whether flat or curved. It is desirable that the uncured liquid resin can be cured by heating, humidification, irradiation with energy such as light, or a combination thereof. The resin is not limited to any particular resin, as long as it satisfies either condition (I) to (VI) for the transmission spectrum of the light absorber 10 at an incident angle of 0°, or condition (90% or more) for the transmission spectrum of a plate-like body formed by curing the resin, having a smooth surface and a thickness of 1 mm, in the wavelength range of 450 nm to 800 nm. Examples of resins include cyclic polyolefin resins, epoxy resins, polyimide resins, modified acrylic resins, silicone resins, and polyvinyl resins such as PVB.

[0055] (curing catalyst) The light absorber 10 or its precursor, a light-absorbing composition, may contain a curing catalyst related to the curing of the resin described above. The curing catalyst may be a catalyst capable of controlling conditions such as the curing speed of the resin, the reactivity of the resin curing, and the hardness of the cured resin.

[0056] As the curing catalyst, an organic compound containing a metal component (organometallic compound) is preferred. The organometallic compound is not limited to a specific compound. As the organometallic compound, organoaluminum compounds, organotitanium compounds, organozirconium compounds, organozinc compounds, or organotin compounds may be used.

[0057] Organoaluminum compounds are not limited to these, but include aluminum salt compounds such as aluminum triacetate and aluminum octylate, aluminum alkoxide compounds such as aluminum trimethoxide, aluminum triethoxide, aluminum dimethoxide, aluminum diethoxide, aluminum triallyloxide, aluminum diallyloxide, and aluminum isopropoxide, as well as aluminum methoxybis(ethyl acetate), aluminum methoxybis(acetylacetonate), aluminum ethoxybis(ethyl acetate), aluminum ethoxybis(acetylacetonate), and aluminum isopropoxybis(ethyl acetate). Examples of aluminum chelate compounds include aluminum isopropoxybis(methylacetate), aluminum isopropoxybis(t-butylacetate), aluminum butoxybis(ethylacetate), aluminum dimethoxy(ethylacetate), aluminum dimethoxy(acetylacetonate), aluminum diethoxy(ethylacetate), aluminum diethoxy(acetylacetonate), aluminum diisopropoxy(ethylacetate), aluminum diisopropoxy(methylacetate), aluminum tris(ethylacetate), and aluminum tris(acetylacetonate). These may be used individually or in combination.

[0058] Examples of organotitanium compounds include, but are not limited to, titanium chelates such as titanium tetraacetylacetonate, dibutyloxytitanium diacetylacetonate, titanium ethylacetoacetate, titanium octylene glycolate, and titanium lactate, as well as titanium alkoxides such as tetraisopropyl titanate, tetrabutyl titanate, tetramethyl titanate, tetra(2-ethylhexyl titanate), titanium tetra-2-ethylhexoxide, titanium butoxydimer, titanium tetran-butoxide, titanium tetraisopropoxide, and titanium diisopropoxybis(ethylacetoacetate). These may be used individually or in combination.

[0059] Examples of organozirconium compounds include, but are not limited to, zirconium chelates such as zirconium tetraacetylacetonate, zirconium dibutoxybis(ethyl acetate), zirconium monobutoxyacetylacetonate bis(ethyl acetate), zirconium triputoxymonoacetylacetonate, and zirconium tetraacetylacetonate, as well as zirconium alkoxides such as zirconium tetran-n-butoxide and zirconium tetran-n-propoxide. These may be used individually or in combination.

[0060] Examples of organozinc compounds include zinc alkoxides such as dimethoxyzinc, diethoxyzinc, and ethylmethoxyzinc. These may be used individually or in combination.

[0061] Examples of organotin compounds include tin alkoxides such as dimethyl tin oxide, diethyl tin oxide, dipropyl tin oxide, dibutyl tin oxide, dipentyl tin oxide, dihexyl tin oxide, diheptyl tin oxide, and dioctyl tin oxide. These may be used individually or in combination.

[0062] As a curing catalyst, it may further contain at least one alkoxide having a metal component and a hydrolysate of an alkoxide having a metal component, as described above. Alkoxides having a metal component and hydrolysates of alkoxides having a metal component are collectively referred to as "metal alkoxide compounds." Metal alkoxides have the general formula M(OR) n Represented as (where M is a metal element and n is an integer greater than or equal to 1), it is a compound in which a hydrogen atom of the hydroxyl group of an alcohol is replaced by the metal element M. Metal alkoxides form M-OH through hydrolysis and further form MOM bonds through reaction with other metal alkoxide molecules. For example, when a light-absorbing composition contains compounds such as a curable resin, and the fluid light-absorbing composition is cured to form a light absorber 10, the metal alkoxide compound may function as a catalyst to promote the curing of the light-absorbing composition. When a light-absorbing composition is cured by heat treatment, the higher the heat treatment temperature, the more likely it is that environmental resistance such as heat resistance will improve. On the other hand, if the heat treatment temperature is high, the properties of some light-absorbing compounds or the ultraviolet absorbers described later may deteriorate. If the properties of the ultraviolet absorbers deteriorate, the wavelength of light absorbed by the ultraviolet absorbers may deviate from the intended absorption wavelength. There is also a possibility that the absorption capacity of the ultraviolet absorbers will decrease or disappear. However, if the light absorber 10 contains a metal alkoxide compound, the curing of the light-absorbing composition can be promoted even if the heat treatment temperature is not high. As a result, the light absorber 10 is likely to have high environmental resistance.

[0063] The metal component contained in the metal alkoxide compound is not limited to specific components. Examples of the metal component are, for example, Al, Ti, Zr, Zn, Sn, and Fe. As the metal alkoxide, for example, CAT-AC and DX-9740 which are aluminum alkoxides manufactured by Shin-Etsu Chemical Co., Ltd., Organicx AL-3001 which is an aluminum alkoxide manufactured by Matsumoto Fine Chemical Co., Ltd., aluminum isopropoxide which is an aluminum alkoxide manufactured by Tokyo Chemical Industry Co., Ltd., D-20, D-25, and DX-175 which are titanium alkoxides manufactured by Shin-Etsu Chemical Co., Ltd., Organicx TA-8, TA-21, TA-30, TA-80, and TA-90 which are titanium alkoxides manufactured by Matsumoto Fine Chemical Co., Ltd., D-15 and D-31 which are zirconia alkoxides manufactured by Shin-Etsu Chemical Co., Ltd., and Organicx ZA-45 and ZA-65 which are zirconia alkoxides manufactured by Matsumoto Fine Chemical Co., Ltd. can be used.

[0064] The ratio of the content of the copper component to the content of the metal component contained in the metal alkoxide compound in the light absorber 10 is not limited to a specific value. The ratio of the content of the copper component to the content of the metal component contained in the metal alkoxide compound in the light absorber 10 is, on a mass basis, 1×10 2 ~7×10 2 and may be, preferably 2×10 2 ~6×10 2 and may be, more preferably 3×10 2 ~5×10 2 and may be.

[0065] Furthermore, the ratio of the content of the phosphorus component to the content of the metal component contained in the metal alkoxide compound in the light absorber 10 is not limited to a specific value. The ratio of the content of the phosphorus component to the content of the metal component contained in the metal alkoxide compound in the light absorber 10 is, on a mass basis, 0.5×10 2 ~5×10 2 and may be, preferably 1×10 2 ~4×10 2 and may be, more preferably 1.5×10 2 ~3×102 It may be.

[0066] (Ultraviolet absorber) The light absorber 10 or the light-absorbing composition which is a precursor thereof may contain an ultraviolet absorber that absorbs a part of light belonging to ultraviolet rays. The ultraviolet absorber is not limited to a specific compound as long as the transmission spectrum of the light absorber 10 at an incident angle of 0° satisfies the conditions (I) to (VI). The ultraviolet absorber is, for example, a compound that does not have both a hydroxy group and a carbonyl group in the molecule, and when represented by a structural formula, is a compound that does not have both a hydroxy group and a carbonyl group in one molecule. The curing of the light-absorbing composition can be promoted by the coordination of a reactant or a precursor at a specific position in the molecule such as an alkoxide having a metal component. For example, if there is a group that is likely to coordinate with a substance other than the substance used for the reaction for curing the light-absorbing composition, the action of the catalyst may be weakened. In particular, both the hydroxy group and the carbonyl group have a high electron-donating property, and when an alkoxide compound reacts or coordinates with an ultraviolet absorber having these groups, and a part of them forms a complex, the ultraviolet absorption characteristics originally possessed by the ultraviolet absorber may change. However, when the ultraviolet absorber is a compound that does not have both a hydroxy group and a carbonyl group in the molecule, the alkoxide compound is less likely to form a complex with the ultraviolet absorber, and the original ultraviolet absorption characteristics of the ultraviolet absorber are likely to be exhibited. Note that the ultraviolet absorber may contain only one of the hydroxy group and the carbonyl group in the molecule.

[0067] UV absorbers are preferably selected from the viewpoint of absorbing light in a desired wavelength range, being compatible with specific solvents, dispersing well in light-absorbing compositions, especially curable resins, and having excellent environmental resistance. Examples of UV absorbers include benzophenone compounds, benzotriazole compounds, salicylic acid compounds, and triazine compounds. For example, Tinuvin PS, Tinuvin 99-2, Tinuvin 234, Tinuvin 326, Tinuvin 329, Tinuvin 900, Tinuvin 928, Tinuvin 405, and Tinuvin 460 can be used as UV absorbers. These are UV absorbers manufactured by BASF, and Tinuvin is a registered trademark.

[0068] The amount of ultraviolet absorber in the light absorber 10 is not limited to a specific value, as long as the transmission spectrum of the light absorber 10 at an incident angle of 0° satisfies conditions (I) to (VI). High absorption capacity can be achieved with a small amount of ultraviolet absorber. The ratio of the amount of ultraviolet absorber to the amount of copper component in the light absorber 10 is, for example, 0.01 to 1 by mass, preferably 0.02 to 0.5, and more preferably 0.07 to 0.14. The ratio of the amount of ultraviolet absorber to the amount of phosphorus component in the light absorber 10 is, for example, 0.02 to 2 by mass, preferably 0.04 to 1, and more preferably 0.12 to 0.26.

[0069] As shown in Figure 1A, the light absorber 10 is, for example, a film. In this specification, "film" is synonymous with "coating" or "layer." The light absorber 10 is not limited to being a film.

[0070] The thickness of the light absorber 10 is not limited to a specific value, as long as the transmission spectrum of the light absorber 10 at an incident angle of 0° satisfies conditions (I) to (VI). The thickness of the light absorber 10 is, for example, 120 μm or less, preferably 100 μm or less, and more preferably 80 μm or less. A small thickness of the light absorber 10 is advantageous from the viewpoint of lowering the background of the imaging device equipped with the light absorber 10.

[0071] In order to impart flexibility to the film-like light absorber 10 and to allow the inclusion of a light-absorbing compound containing phosphonic acid and copper components, which have excellent light-absorbing properties, as a light absorber, it is preferable to include a silicone resin as the curable resin. Furthermore, a curing catalyst may be added to improve the curability of the resin, such as the silicone resin. The curing catalyst for the silicone resin is preferably a compound containing a metal component, such as a chelate containing a metal component or an alkoxide containing a metal component. On the other hand, when an ultraviolet absorber is added for the purpose of controlling the spectrum on the short-wavelength side, interactions occur between the metal component contained in the curing catalyst, etc., and the ultraviolet absorber, which can change the absorption characteristics inherent in the ultraviolet absorber, such as causing a large shift in the cut-off wavelength on the short-wavelength side. For this reason, conventionally, the layer containing the ultraviolet absorber and the layer containing the resin containing the light absorber containing phosphonic acid and copper had to be provided as separate layers, which tended to increase the thickness of the light absorber. In the present invention, even when a curing catalyst of a resin made of a compound containing a metal component is included in a single layer or film, the ultraviolet absorber can be encapsulated in the same layer or film by using a specific ultraviolet absorber. This makes it possible to allow the UV absorber to exhibit its original UV absorption performance, enabling the light absorber 10 to be obtained with fewer layers, and consequently reducing the thickness of the light absorber 10.

[0072] The light absorber 10 can be prepared, for example, by curing a predetermined light-absorbing composition.

[0073] The light-absorbing composition is not limited to a specific composition, as long as the transmission spectrum of the light absorber 10 at an incident angle of 0° satisfies conditions (I) to (VI). The light-absorbing composition may, for example, contain a light-absorbing compound comprising phosphonic acid and a copper component, and an ultraviolet absorber that absorbs at least a portion of ultraviolet light. With regard to the light-absorbing compound, refer to the description of the light-absorbing compound in the light absorber 10.

[0074] The light-absorbing composition further contains, for example, at least one alkoxide having a metal component and a hydrolysate of the alkoxide having a metal component. For details regarding the alkoxide having a metal component and the hydrolysate of the alkoxide having a metal component, refer to the description of the alkoxide compound in the light absorber 10.

[0075] As long as the transmission spectrum of the light absorber 10 at an incident angle of 0° satisfies conditions (I) to (VI), the ultraviolet absorber in the light-absorbing composition is not limited to a specific compound. For example, refer to the description of the ultraviolet absorber in the light absorber 10. An ultraviolet absorber is, for example, a compound that does not contain both a hydroxyl group and a carbonyl group in its molecule. In other words, the ultraviolet absorber may be a compound that contains only one of either a hydroxyl group or a carbonyl group.

[0076] The light-absorbing composition further contains, for example, a phosphate ester. This facilitates the proper dispersion of the light-absorbing compound in the light-absorbing composition. Regarding the phosphate ester, refer to the description of the phosphate ester in light absorber 10.

[0077] The light-absorbing composition further contains, for example, a curable resin. For details regarding the curable resin, please refer to the description of the resin in the light absorber 10.

[0078] In the preparation of light-absorbing compositions, the source of the copper component in the light-absorbing compound is not limited to a specific substance. A copper component source is, for example, a copper salt. The copper salt may be an anhydrous or hydrate of copper chloride, copper formate, copper stearate, copper benzoate, copper pyrophosphate, copper naphthenate, and copper citrate. For example, copper acetate monohydrate is represented as Cu(CH3COO)2·H2O, and 1 mole of copper acetate monohydrate supplies 1 mole of copper ions.

[0079] For example, a component on which a light absorber 10 is formed on the surface of an article can be used as an optical filter. In addition, the light absorber 10 can be formed on the surface of an article and then peeled off, allowing the light absorber 10 itself to be used independently as an optical filter. The method for manufacturing the light absorber 10 is not limited to any particular method. The light absorber 10 may be manufactured by methods such as casting, compression molding, vacuum forming, press molding, injection molding, blow molding, and extrusion molding.

[0080] As shown in Figure 1A, the light absorber 10 may be used alone. On the other hand, as shown in Figure 1B, an article 1a with a light absorber can be provided. The article 1a with a light absorber comprises an article 20 and a light absorber 10. The light absorber 10 covers at least a portion of the surface of the article 20.

[0081] The shape of article 20 in article 1a with light absorber is not limited to a specific shape. Article 20 may be a flat plate-shaped member or substrate. Article 20 is not limited to a specific article. Article 20 may be, for example, an optical element (including acousto-optical elements) such as a lens, mirror, prism, diffuser, planar microlens array, polarizer, diffraction grating, hologram, optical modulator, optical deflection element, and filter. Article 20 may also be a solid-state imaging device, a window or windshield of a building or automobile, a light-transmitting shield such as a helmet and goggles, or a display device such as a display and screen. Article 1a with light absorber may be a so-called optical filter. The surface of article 20 covered by the light absorber 10 may be flat, curved, or have irregularities.

[0082] A light absorber 10 may be obtained by molding an optical element such as a lens using a light-absorbing composition. In this case, the light absorber 10 may be used alone.

[0083] (Functional membrane) As shown in Figures 1C and 1D, the article 1a with a light absorber or the light absorber 10 may be equipped with other functional films 30. The other functional films are not limited to a specific film and may include a hard coating film (hard coat) for improving scratch resistance, a reflection reduction film or anti-reflection film (hereinafter collectively referred to as "anti-reflection film") for reducing or preventing reflected light belonging to a specific wavelength range from their surfaces when light is incident on the article 1a with a light absorber or the light absorber 10, a film (hereinafter referred to as "reflective film") for reflecting more light belonging to a specific wavelength range from their surfaces when light is incident on the article 1a with a light absorber or the light absorber 10, a polarizing film for reducing the transmittance of light with polarization directions other than a specific direction when light is incident on the article 1a with a light absorber or the light absorber 10, or a selective wavelength light absorption film that absorbs light in a certain wavelength range by other configurations or predetermined actions. The functional film 30 may consist of any one of these functional films individually, or it may be composed of multiple functional films.

[0084] If the article 1a with a light absorber or the light absorber 10 is equipped with an anti-reflective coating as a functional film 30, the article 1a with a light absorber or the light absorber 10 may be equipped with the anti-reflective coating on one main surface or on both main surfaces. Here, the main surface is the surface of the substrate such as the article 1a with a light absorber or the light absorber 10 that has the largest surface area.

[0085] An anti-reflective coating has, for example, one or more layers made of one or more types of materials. The materials constituting the anti-reflective coating are not limited to specific materials. For example, an anti-reflective coating may be made of SiO2 or SiO2. 1.5 , TiO2 and TiO 1.5The anti-reflective film may be formed by a sol-gel method or the like with the main component being TiO2, or it may be a film in which hollow fine particles or fine particles of a low refractive index material are dispersed in the main component. The anti-reflective film may contain TiO2, Ta2O3, SiO2, Nb2O5, ZnS, MgF, or a mixture thereof, and may be a film formed by a method such as vapor deposition, sputtering, or ion plating. The vapor deposition method may be an ion beam-assisted vapor deposition method. The anti-reflective film may be a single-layer film containing the above materials, or it may be a multilayer film (dielectric multilayer film) in which films of different materials are alternately stacked. Furthermore, the anti-reflective film may be formed in contact with the light absorber 10, or in contact with other functional layer films formed in contact with the light absorber 10.

[0086] Furthermore, if the article 1a with a light absorber or the light absorber 10 is equipped with a light-reflective film as a functional film 30, the light absorber 10 and the light-reflective film may work together to provide a light shielding function. This cooperation can reduce or shield the transmission of light belonging to a specific wavelength range, thereby reducing the burden on the light absorber 10 in terms of light absorption characteristics. For example, the thickness of the light absorber 10 can be reduced. In addition, the content of light-absorbing compounds such as light absorbers or ultraviolet absorbers in the light absorber 10 can also be reduced.

[0087] The selective wavelength light-absorbing film is not limited to a specific film, and may be a film of metal such as Ag (silver), Al (aluminum), Au (gold), and Pt (platinum), or a film containing one or more of these metals or other metals. In particular, metal films can be used as simple films that exhibit light reflection or light absorption functions because they can cover a wide wavelength range and have a simple structure. Such selective wavelength light-absorbing films can be used as neutral density (ND) films or half mirrors.

[0088] When a light absorber uses an ultraviolet absorber containing both hydroxyl and carbonyl groups, the ultraviolet absorber may react with metal ions contained in functional films such as reflective and anti-reflective films, leading to structural changes associated with complex formation. In such cases, the ultraviolet absorption capacity changes, such as a shift in the absorption band to longer wavelengths, making it impossible to obtain the desired optical properties. Since the ultraviolet absorber contained in light absorber 10 is a compound that does not have both hydroxyl and carbonyl groups in its molecule, even when a functional film containing metal components other than Si, such as Ti, Mg, and Ta, is formed, changes in optical properties due to the reaction between the metal components and the ultraviolet absorber, particularly a decrease in transmittance in the visible range, do not occur at the interface between the functional film and the light absorber, which is advantageous. It is also advantageous in that problems such as film peeling or wrinkle formation due to complex formation reactions can be suppressed at the same interface.

[0089] A device equipped with a light absorber 10 can be provided. The applications of such a device are not limited to specific uses. Examples of such devices include in-vehicle cameras and in-vehicle sensors. In this case, since the light absorber 10 has a predetermined ultraviolet absorption capacity, the image sensor and sensor element can be protected from ultraviolet light. Furthermore, since the light absorber 10 has a high transmittance around a wavelength of 700 nm, the light absorber 10 can be used in sensing systems such as light detection and ranging (Lidar) systems using infrared or red lasers. In particular, the light absorber 10 has high transmittance of red light, so a device equipped with the light absorber 10 tends to have a higher ability to recognize objects such as red traffic lights and road signs. In addition, since the light absorber 10 shields light in a specific wavelength range by absorption, ghosting and flare can be suppressed in a device equipped with the light absorber 10. Furthermore, Lidar systems can be installed not only in in-vehicle equipment but also in portable information terminals such as smartphones.

[0090] As shown in Figure 2, for example, an imaging device 100 equipped with a light absorber 10 can be provided. The imaging device 100 further comprises, for example, a lens system 40 and an image sensor 50. The light absorber 10 is positioned, for example, between the lens system 40 and the image sensor 50. The application of the imaging device 100 is not limited to a specific product. The imaging device 100 can be applied, for example, as a camera module mounted on a portable information terminal such as a smartphone, a device incorporated into an in-vehicle sensing module, and a device incorporated into a sensing module in an unmanned aerial vehicle such as a drone or an unmanned surface vehicle (USV). The light absorber 10 may also be applied to an ambient light sensor for detecting the ambient brightness of a device on which the light absorber 10 is mounted. [Examples]

[0091] The present invention will be described in more detail by reference to examples. However, the present invention is not limited to the following examples. First, the evaluation method for optical filters in each example and comparative example will be described.

[0092] (Transmission spectrum measurement) The transmission spectra of the optical filters according to each example were measured at incident angles of 0°, 35°, 45°, and 55° using a UV-Vis-Near-Infrared Spectrophotometer V-670 manufactured by JASCO Corporation. The transmission spectra of the optical filters according to Examples 1 to 3 are shown in Figures 3A to 5C. Similarly, the transmission spectra of the optical filters according to each comparative example were measured at an incident angle of 0°. The results are shown in Figures 6 to 9. The characteristic values ​​of each optical filter obtained from these transmission spectra are shown in Tables 7 to 9. In Tables 7 to 9, the subscript "IA" in each item indicates the incident angle [°].

[0093] (Thickness measurement) The thickness of the optical filter was measured using a Keyence LK-H008 laser displacement meter. The results are shown in Table 7.

[0094] <Example 1> 4.500 g of copper acetate monohydrate and 240 g of tetrahydrofuran (THF) were mixed and stirred for 3 hours to obtain a copper acetate solution. Next, 2.572 g of the phosphate ester compound Prysurf A208N, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., was added to the obtained copper acetate solution and stirred for 30 minutes to obtain solution A. Also, 2.886 g of n-butylphosphonic acid was mixed with 40 g of THF and stirred for 30 minutes to obtain solution B. Solution B was added to solution A while stirring and stirred at room temperature for 1 minute. Next, 100 g of toluene was added to this solution and stirred at room temperature for 1 minute to obtain solution C. Solution C was placed in a flask and desolvated using a rotary evaporator (manufactured by Tokyo Rikakikai Co., Ltd., model: N-1110SF) while being heated in an oil bath (manufactured by Tokyo Rikakikai Co., Ltd., model: OSB-2100). The oil bath temperature was set to 105°C. After that, solution D was removed from the flask after desolvation. In this way, composition α containing a compound formed by phosphonic acid and a copper component was obtained. It was inferred that the compound formed by phosphonic acid and a copper component was dispersed as fine particles in the composition.

[0095] 5 g of the benzotriazole-based ultraviolet absorber Tinuvin 326, manufactured by BASF, was added to 95 g of toluene, and the mixture was stirred for 30 minutes to obtain composition β-1 containing the ultraviolet absorber. Tinuvin 326 contained 2-[5-Chloro-(2H)-Benzotriazol-2-yl]-4-methyl-6-(tert-butyl)phenol, represented by the following formula (b-1).

[0096] [ka]

[0097] Composition α, 2.0 g of Composition β-1, and 0.09 g of CAT-AC manufactured by Shin-Etsu Chemical Co., Ltd., which contains an aluminum alkoxide compound, were added to 8.80 g of silicone resin KR-300 manufactured by Shin-Etsu Chemical Co., Ltd., and stirred for 30 minutes to obtain the light-absorbing composition according to Example 1. The amount of materials added in the preparation of the light-absorbing composition or the content of the predetermined components in the light-absorbing composition is shown in Table 1. The ratio of the component content is shown in Table 4. The average molecular weight of Prysurf A208N used as the phosphate ester was determined to be 632 g / mol.

[0098] A fluorine treatment agent (active ingredient concentration: 0.1% by mass) was prepared by mixing 0.1 g of Optool DSX, a surface antifouling coating agent manufactured by Daikin Industries, Ltd. (active ingredient concentration: 20% by mass), with 19.9 g of Novec 7100, a hydrofluoroether-containing liquid manufactured by 3M, and stirring for 5 minutes. This fluorine treatment agent was applied to a borosilicate glass substrate (manufactured by SCHOTT, product name: D263 T eco) with dimensions of 130 mm × 100 mm × 0.70 mm using the flow-coating method. The glass substrate was then left at room temperature for 24 hours to dry the fluorine treatment agent coating, and then the glass surface was lightly wiped with a dust-free cloth containing Novec 7100 to remove excess fluorine treatment agent. A fluorine-treated substrate was thus prepared.

[0099] A light-absorbing composition according to Example 1 was applied to an 80 mm × 80 mm area in the center of one main surface of a fluorine-treated substrate using a dispenser to form a coating film. After the obtained coating film was thoroughly dried at room temperature, it was placed in an oven and dried by slowly increasing the temperature in the range of room temperature to 45°C to evaporate the solvent, and finally heat-treated at 85°C for 6 hours to completely evaporate the solvent and cure it. After that, the coating film was peeled off the fluorine-treated substrate to obtain an optical filter according to Example 1 consisting of a film-like light absorber. The transmission spectra of the optical filter according to Example 1 at incident angles of 0° and 35°, 0° and 45°, and 0° and 55° are shown in Figures 3A, 3B, and 3C, respectively. The parameters observed from the transmission spectra are shown in Table 7.

[0100] <Example 2> As an ultraviolet absorber, 5.0 g of Tinuvin 234, a benzotriazole-based ultraviolet absorber manufactured by BASF, was added to 95.0 g of toluene and stirred for 30 minutes to prepare composition β-2 containing the ultraviolet absorber. Tinuvin 234 contained Phenol,2-(2H-Benzotriazol-2-yl)-4,6-bis(1-methyl-1-Phenylethyl), represented by the following formula (b-2). The light-absorbing composition according to Example 2 was prepared in the same manner as in Example 1, except that 3.6 g of composition β-2 was added instead of 2.0 g of composition β-1. The amount of material added in the preparation of the light-absorbing composition or the content of the specified components in the light-absorbing composition is shown in Table 1. The ratio of the component content is shown in Table 4.

[0101] [ka]

[0102] An optical filter according to Example 2, consisting of a film-like light absorber, was fabricated in the same manner as in Example 1, except that the light-absorbing composition according to Example 2 was used instead of the light-absorbing composition according to Example 1. The transmission spectra of the optical filter according to Example 2 at incident angles of 0° and 35°, 0° and 45°, and 0° and 55° are shown in Figures 4A, 4B, and 4C, respectively. The parameters observed from the transmission spectra are shown in Table 7.

[0103] <Example 3> As an ultraviolet absorber, 5.0 g of Tinuvin 329, a benzotriazole-based ultraviolet absorber manufactured by BASF, was added to 95.0 g of toluene and stirred for 30 minutes to prepare composition β-3 containing the ultraviolet absorber. Tinuvin 329 contained 2Phenol,2-(2H-Benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl), represented by the following formula (b-3). In the preparation of the light-absorbing composition, the light-absorbing composition according to Example 3 was prepared in the same manner as in Example 1, except that 4.0 g of composition β-3 was added instead of 2.0 g of composition β-1. The amount of materials added in the preparation of the light-absorbing composition or the content of the predetermined components in the light-absorbing composition is shown in Table 1. The ratio of the component content is shown in Table 4.

[0104] [ka]

[0105] An optical filter according to Example 3, consisting of a film-like light absorber, was prepared in the same manner as in Example 1, except that the light-absorbing composition according to Example 3 was used instead of the light-absorbing composition according to Example 1. The transmission spectra of the optical filter according to Example 3 at incident angles of 0° and 35°, 0° and 45°, and 0° and 55° are shown in Figures 5A, 5B, and 5C, respectively. The parameters observed from the transmission spectra are shown in Table 7.

[0106] <Example 4> The light-absorbing composition according to Example 4 was prepared in the same manner as in Example 1, except that 0.025 g of aluminum isopropoxide (containing 13.21% by mass of Al component) manufactured by Tokyo Chemical Industry Co., Ltd. was added instead of CAT-AC containing aluminum alkoxide. The amount of material added in the preparation of the light-absorbing composition or the content of the predetermined components in the light-absorbing composition is shown in Table 2. The ratio of the component content is shown in Table 5.

[0107] An optical filter according to Example 4, consisting of a film-like light absorber, was prepared in the same manner as in Example 1, except that the light-absorbing composition according to Example 4 was used instead of the light-absorbing composition according to Example 1. The transmission spectra of the optical filter according to Example 4 were measured at incident angles of 0°, 35°, 45°, and 55°. Table 8 shows the transmission spectra at incident angles of 0° and 55° and the parameters that can be observed from their comparison.

[0108] <Example 5> A light-absorbing composition according to Example 5 was prepared in the same manner as in Example 1, except that 0.038 g of Orgatics AL-3001 (10.7% by mass Al content) manufactured by Matsumoto Fine Chemical Co., Ltd., which contains aluminum trisecondary butoxide, was added instead of CAT-AC containing aluminum alkoxide. The amount of materials added in the preparation of the light-absorbing composition or the content of the predetermined components in the light-absorbing composition is shown in Table 2. The ratio of the component content is shown in Table 5.

[0109] An optical filter according to Example 5, consisting of a film-like light absorber, was prepared in the same manner as in Example 1, except that the light-absorbing composition according to Example 5 was used instead of the light-absorbing composition according to Example 1. The transmission spectra of the optical filter according to Example 5 were measured at incident angles of 0°, 35°, 45°, and 55°. Table 8 shows the transmission spectra at incident angles of 0° and 55° and the parameters that can be observed from their comparison.

[0110] <Example 6> The light-absorbing composition according to Example 6 was prepared in the same manner as in Example 1, except that 0.05 g of Orgatics TA-8 (Ti component content 16.9% by mass), manufactured by Matsumoto Fine Chemical Co., Ltd., which contains titanium tetraisopropoxide, was added instead of CAT-AC, which contains aluminum alkoxide. The amount of material added in the preparation of the light-absorbing composition or the content of the predetermined components in the light-absorbing composition is shown in Table 2. The ratio of the component content is shown in Table 5.

[0111] An optical filter according to Example 6, consisting of a film-like light absorber, was prepared in the same manner as in Example 1, except that the light-absorbing composition according to Example 6 was used instead of the light-absorbing composition according to Example 1. The transmission spectra of the optical filter according to Example 6 were measured at incident angles of 0°, 35°, 45°, and 55°. Table 8 shows the transmission spectra at incident angles of 0° and 55° and the parameters that can be observed from their comparison.

[0112] <Example 7> The light-absorbing composition according to Example 7 was prepared in the same manner as in Example 2, except that 0.07 g of Orgatics TA-30 (Ti component content 8.5% by mass), manufactured by Matsumoto Fine Chemical Co., Ltd., which contains titanium tetra-2-ethylhexoxide, was added instead of CAT-AC, which contains aluminum alkoxide. The amount of materials added in the preparation of the light-absorbing composition or the content of the predetermined components in the light-absorbing composition is shown in Table 2. The ratio of the component content is shown in Table 5.

[0113] An optical filter according to Example 7, consisting of a film-like light absorber, was prepared in the same manner as in Example 2, except that the light-absorbing composition according to Example 7 was used instead of the light-absorbing composition according to Example 2. The transmission spectra of the optical filter according to Example 7 were measured at incident angles of 0°, 35°, 45°, and 55°. Table 8 shows the transmission spectra at incident angles of 0° and 55° and the parameters that can be observed from their comparison.

[0114] <Example 8> A light-absorbing composition according to Example 8 was prepared in the same manner as in Example 1, except that 0.06 g of Orgatics ZA-45 (containing 21.0% by mass of Zr component) manufactured by Matsumoto Fine Chemical Co., Ltd., which contains zirconium tetran-n-propoxide, was added instead of CAT-AC containing aluminum alkoxide. The amount of material added in the preparation of the light-absorbing composition or the content of the predetermined components in the light-absorbing composition is shown in Table 2. The ratio of the component content is shown in Table 5.

[0115] An optical filter according to Example 8, consisting of a film-like light absorber, was prepared in the same manner as in Example 1, except that the light-absorbing composition according to Example 8 was used instead of the light-absorbing composition according to Example 1. The transmission spectra of the optical filter according to Example 8 were measured at incident angles of 0°, 35°, 45°, and 55°. Table 8 shows the transmission spectra at incident angles of 0° and 55° and the parameters that can be observed from their comparison.

[0116] <Comparative Example 1> A light-absorbing composition according to Comparative Example 1 was prepared in the same manner as in Example 1, except that composition β-1 was not added. The amount of material added in the preparation of the light-absorbing composition or the content of the predetermined components in the light-absorbing composition is shown in Table 3. The ratio of the component content is shown in Table 6.

[0117] An optical filter according to Comparative Example 1, consisting of a film-like light absorber, was prepared in the same manner as in Example 1, except that the light-absorbing composition according to Comparative Example 1 was used instead of the light-absorbing composition according to Example 1. The transmission spectrum of the optical filter according to Comparative Example 1 at an incident angle of 0° is shown in Figure 6. The parameters that can be observed from the transmission spectrum are shown in Table 9.

[0118] <Comparative Example 2> As an ultraviolet absorber, 2.0 g of the hydroxybenzophenone-based ultraviolet absorber Uvinul3049 manufactured by BASF was added to 98.0 g of toluene and stirred for 30 minutes to prepare composition β-4 containing the ultraviolet absorber. Uvinul3049 contained a compound represented by the following formula (b-4). A light-absorbing composition according to Comparative Example 2 was prepared in the same manner as in Example 1, except that 5.0 g of composition β-4 was added instead of 2.0 g of composition β-1 in the preparation of the light-absorbing composition. The amount of material added in the preparation of the light-absorbing composition or the content of the predetermined components in the light-absorbing composition is shown in Table 3. The ratio of the component content is shown in Table 6.

[0119] [ka]

[0120] An optical filter according to Comparative Example 2, consisting of a film-like light absorber, was prepared in the same manner as in Example 1, except that the light-absorbing composition according to Comparative Example 2 was used instead of the light-absorbing composition according to Example 1. The transmission spectrum of the optical filter according to Comparative Example 2 at an incident angle of 0° is shown in Figure 7. The parameters that can be observed from the transmission spectrum are shown in Table 9.

[0121] <Comparative Example 3> 2.0 g of the UV absorber Uvinul3049 was added to 98.0 g of toluene and stirred for 30 minutes to prepare a composition containing the UV absorber. 5.0 g of this composition was added to 10.0 g of the silicone resin KR-300 manufactured by Shin-Etsu Chemical Co., Ltd. and stirred for 30 minutes to obtain the light-absorbing composition according to Comparative Example 3. Table 3 shows the amount of material added in the preparation of the light-absorbing composition or the content of the specified components in the light-absorbing composition. Table 6 shows the ratio of the component content.

[0122] An optical filter according to Comparative Example 3, consisting of a film-like light absorber, was prepared in the same manner as in Example 1, except that the light-absorbing composition according to Comparative Example 3 was used instead of the light-absorbing composition according to Example 1. The transmission spectrum of the optical filter according to Comparative Example 3 at an incident angle of 0° is shown in Figure 8. The parameters that can be observed from the transmission spectrum are shown in Table 9.

[0123] <Comparative Example 4> A composition containing the UV absorber was prepared by adding 2.0 g of the UV absorber Uvinul3049 to 98.0 g of toluene and stirring for 30 minutes. 5.0 g of this composition and 0.10 g of aluminum alkoxide CAT-AC manufactured by Shin-Etsu Chemical Co., Ltd. were added to 10.0 g of silicone resin KR-300 manufactured by Shin-Etsu Chemical Co., Ltd. and stirred for 30 minutes to obtain the light-absorbing composition according to Comparative Example 4. The amount of materials added in the preparation of the light-absorbing composition or the content of the specified components in the light-absorbing composition is shown in Table 3. The ratio of the component content is shown in Table 6.

[0124] An optical filter according to Comparative Example 4, consisting of a film-like light absorber, was prepared in the same manner as in Example 1, except that the light-absorbing composition according to Comparative Example 4 was used instead of the light-absorbing composition according to Example 1. The transmission spectrum of the optical filter according to Comparative Example 4 at an incident angle of 0° is shown in Figure 9. The parameters that can be observed from the transmission spectrum are shown in Table 9.

[0125] As shown in Tables 7 and 8, the transmission spectra of the optical filters according to each embodiment indicate that these optical filters had the desired transmittance characteristics. On the other hand, according to the transmission spectrum of the optical filter according to Comparative Example 1 at an incident angle of 0°, the wavelength λ in the range of 350 nm to 450 nm is such that the transmittance is 50%. 50 0(UV) It is 354nm, and T M (350-370) The figure exceeded 70%. Therefore, it was difficult to say that the optical filter according to Comparative Example 1 had the desired transmittance characteristics.

[0126] According to the transmission spectrum of the optical filter in Comparative Example 2 at an incident angle of 0°, λ 50 0(UV) The wavelength was 443 nm. For this reason, it is difficult to say that the optical filter according to Comparative Example 2 had the desired transmittance characteristics. The ultraviolet absorber Uvinul3049 used in the fabrication of the optical filter according to Comparative Example 2 contains both hydroxyl and carbonyl groups in its molecule, and it is presumed that the ultraviolet absorber partially reacted with the alkoxide compound containing a metal component, which was used as a catalyst, causing the original absorption wavelength of the ultraviolet absorber to shift to the longer wavelength side.

[0127] Comparative Examples 3 and 4 are examples for examining the differences in the transmission spectrum of optical filters due to the presence or absence of aluminum alkoxide in the light-absorbing composition. The difference in light absorption characteristics of the optical filters in Comparative Examples 3 and 4 is particularly noticeable at the wavelength λ where the transmittance is 50% in the wavelength range of 350 nm to 450 nm. 50 0(UV)In the optical filter according to Comparative Example 4, which contains both an ultraviolet absorber and an aluminum alkoxide, the wavelength λ 50 0(UV) The wavelength was 444 nm. On the other hand, in the optical filter according to Comparative Example 3, which does not contain aluminum alkoxide, the wavelength λ 50 0(UV) The wavelength was 400 nm. These results suggest that when an ultraviolet absorber containing both hydroxyl and carbonyl groups in its molecule is included together with an alkoxide compound containing a metal component such as aluminum alkoxide, the properties inherent to the ultraviolet absorber change.

[0128] <Example 9> An anti-reflective film was formed on both main surfaces of the optical filter according to Example 1 by vacuum deposition to fabricate the optical filter according to Example 9. The anti-reflective film was a dielectric multilayer film in which layers of SiO2 and TiO2 were alternately stacked, with 9 layers and a film thickness of approximately 0.4 μm. The optical filter according to Example 9 comprises the light absorber according to Example 1 and the anti-reflective film formed on both main surfaces of the light absorber. The transmission spectrum of the optical filter according to Example 9 at an incident angle of 0° is shown in Figure 10. The parameters that can be observed from the transmission spectrum are shown in Table 8.

[0129] [Table 1]

[0130] [Table 2]

[0131] [Table 3]

[0132] [Table 4]

[0133] Table 5

[0134] Table 6

[0135] Table 7

[0136] Table 8

[0137] Table 9

Claims

1. resin and A light absorber containing phosphonic acid and copper components, At least one selected from the group consisting of ultraviolet absorbers having either a hydroxyl group or a carbonyl group in their molecule (excluding compounds having both a hydroxyl group and a carbonyl group in their molecule) and ultraviolet absorbers having a benzotriazole group in their molecule, Includes organometallic compounds containing metal components, Light-absorbing composition.

2. The organometallic compound comprises at least one selected from the group consisting of alkoxides having a metal component and hydrolysates of alkoxides having a metal component. The light-absorbing composition according to claim 1.

3. The light-absorbing composition is capable of forming a light absorber. The light-absorbing composition according to claim 1 or 2.

4. In the light absorber, the mass ratio of the copper content to the content of the metal component derived from the metal component is 1 × 10 2 ~7 x 10 2 That is, The light-absorbing composition according to claim 3.

5. In the light absorber, the mass ratio of the phosphorus content to the content of the metal component derived from the metal component is 0.5 × 10 2 ~5 x 10 2 That is, The light-absorbing composition according to claim 3.

6. In the light absorber, the mass ratio of the ultraviolet absorber content to the copper content is 0.01 to 1. The light-absorbing composition according to claim 3.

7. In the light absorber, the mass ratio of the ultraviolet absorber content to the phosphorus content is 0.02 to 2. The light-absorbing composition according to claim 3.

8. The light-absorbing composition according to claim 3, wherein the transmission spectrum of the light absorber at an incident angle of 0° satisfies the following conditions (i), (ii), (iii), (iv), (v), and (vi). (i) The average transmittance in the wavelength range of 450 nm to 600 nm is 75% or higher. (ii) The first wavelength at which the transmittance is 50% in the wavelength range of 350 nm to 450 nm is between 380 nm and 440 nm. (iii) The second wavelength at which the transmittance is 50% in the wavelength range of 650 nm to 750 nm is between 680 nm and 740 nm. (iv) The maximum transmittance in the wavelength range of 350 nm to 370 nm is 1% or less. (v) The maximum transmittance in the wavelength range of 800 nm to 900 nm is 5% or less. (vi) The maximum transmittance in the wavelength range of 1100 nm to 1200 nm is 5% or less.

9. The light-absorbing composition according to claim 8, wherein the transmission spectrum further satisfies the following condition (vii). (vii) The transmittance at a wavelength of 750 nm is 7% or more.

10. The light-absorbing composition according to claim 8, wherein the transmission spectrum further satisfies the following condition (viii). (viii) The transmittance at a wavelength of 780 nm is 3% or more.

11. The organometallic compound includes the curing catalyst for the resin. The light-absorbing composition according to claim 1 or 2.

12. resin and A light absorber containing phosphonic acid and copper components, At least one selected from the group consisting of ultraviolet absorbers having either a hydroxyl group or a carbonyl group in their molecule (excluding compounds having both a hydroxyl group and a carbonyl group in their molecule) and ultraviolet absorbers having a benzotriazole group in their molecule, Includes organometallic compounds containing metal components, Light absorber.

13. The organometallic compound comprises at least one selected from the group consisting of hydrolysates of alkoxides having a metal component and polymers of hydrolysates of alkoxides having a metal component. The light absorber according to claim 12.

14. The mass ratio of the copper content to the content of the metal component derived from the metal component is 1 × 10² to 7 × 10². The light absorber according to claim 12 or 13.

15. The mass ratio of the phosphorus content to the content of the metal component derived from the metal component is 0.5 × 10² to 5 × 10². The light absorber according to claim 12 or 13.

16. The mass ratio of the content of the ultraviolet absorber to the content of copper is 0.01 to 1. The light absorber according to claim 12 or 13.

17. The mass ratio of the content of the ultraviolet absorber to the content of phosphorus is 0.02 to 2. The light absorber according to claim 12 or 13.

18. The light absorber according to claim 12 or 13, wherein the transmission spectrum at an incident angle of 0° satisfies the following conditions (I), (II), (III), (IV), (V), and (VI). (I) The average transmittance in the wavelength range of 450 nm to 600 nm is 75% or higher. (II) The first wavelength at which the transmittance is 50% in the wavelength range of 350 nm to 450 nm is between 380 nm and 440 nm. (III) The second wavelength at which the transmittance is 50% in the wavelength range of 650 nm to 750 nm is between 680 nm and 740 nm. (IV) The maximum transmittance in the wavelength range of 350 nm to 370 nm is 1% or less. (V) The maximum transmittance in the wavelength range of 800 nm to 900 nm is 5% or less. (VI) The maximum transmittance in the wavelength range of 1100 nm to 1200 nm is 5% or less.

19. A light absorber according to claim 12 or 13, It comprises an optical system including a lens, The light absorber is arranged on the optical path in the optical system. Device.

20. The apparatus is applied to at least one selected from the group consisting of a sensing device that detects an object using light in a specific wavelength band, an imaging device, and an optical environment sensor device that detects the surrounding light environment. The apparatus according to claim 19.

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