Near-infrared absorbing composition, near-infrared absorbing cured film, and optical member

Abstract

The present invention addresses the problem of providing: a near-infrared absorbing composition which has excellent storage stability; a near-infrared absorbing cured film which uses the near-infrared absorbing composition and has excellent moisture and heat resistance, and excellent antifogging properties; and an optical member.　A near-infrared absorbing composition according to the present invention is characterized by containing component (A) that is a near-infrared absorbing compound, component (B) that is a dispersant, and a solvent.

Description

Near-infrared absorbing composition, near-infrared absorbing cured film, and optical component

[0001] The present invention relates to a near-infrared absorbing composition, a near-infrared absorbing cured film, and an optical component. More specifically, the present invention relates to a near-infrared absorbing composition having excellent storage stability, a near-infrared absorbing cured film having excellent moist heat resistance and anti-fogging properties, and an optical component.

[0002] In recent years, solid-state imaging elements for capturing color images have been used in imaging devices such as video cameras, digital still cameras, and mobile phones with camera functions. Examples of solid-state imaging elements include CCD (Charge Coupled Device) and CMOS (Complementary Metal Oxide Semiconductor) image sensors. These solid-state imaging elements use silicon photodiodes in their light receiving sections. However, since silicon photodiodes are also sensitive to light in the near-infrared wavelength region, the solid-state imaging elements require luminosity correction. To correct the luminosity, a near-infrared cut filter, which is an optical filter, is often used.

[0003] Near-infrared cut filters are broadly divided into absorption type and reflection type, with reflection type filters being the most commonly used. Reflection type near-infrared cut filters utilize light reflection by a dielectric multilayer film to block infrared or ultraviolet rays.

[0004] However, the reflectance and transmittance of the reflective layer applied to a reflective near-infrared cut filter are likely to change depending on the angle of incidence of light. Therefore, total absorption near-infrared cut filters have been studied recently. Among them, optical filters using a film containing a light absorber have attracted attention.

[0005] Optical filters using a film containing a light absorber are advantageous in terms of miniaturizing and thinning an imaging device. Furthermore, the transmittance of such optical filters is less affected by the angle of incidence of light. Therefore, by using such optical filters, good images with little change in color can be obtained even when light is incident on a solid-state imaging device at an oblique angle.

[0006] As a material for such a near-infrared cut filter, a near-infrared absorbing composition using a copper phosphonate complex has been disclosed.

[0007] For example, Patent Document 1 discloses a near-infrared absorbing composition containing a near-infrared absorber containing a phosphate ester compound, a phosphonic acid compound, and copper ions, and a Ti compound. However, the composition disclosed in Patent Document 1 has room for improvement in terms of storage stability, moist heat resistance of the cured film, and anti-fogging property.

[0008] International Publication No. 2019-221061

[0009] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a near-infrared absorbing composition having excellent storage stability, a near-infrared absorbing cured film using the same having excellent moist heat resistance and anti-fogging properties, and an optical component.

[0010] The present inventors have investigated the causes of the above-mentioned problems in order to solve them. As a result, the present inventors have found that the above-mentioned problems can be solved by using a specific copper phosphonate complex as a near-infrared absorbent and a specific phosphate ester as a dispersant in a solvent, and have arrived at the present invention. That is, the above-mentioned problems according to the present invention are solved by the following means.

[0011] 1. A near-infrared absorbing composition comprising the following component (A) which is a near-infrared absorbing compound, the following component (B) which is a dispersant, and a solvent: Component (A) which is a near-infrared absorbing compound: a copper complex coordinated with a compound having a structure represented by the following general formula (I):

[0012]

[0013] [In general formula (I), R １ is an alkyl group having 1 to 20 carbon atoms, which may further have a substituent.] Component (B) as a dispersant: a compound having a structure represented by the following general formula (II). General formula (II) Z(-O-R ２ ) ｘ [In general formula (II), R ２represents an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 1 to 30 carbon atoms, or an aryl group having 6 to 30 carbon atoms. x represents 1 or 2. When x is 1, Z has a structure represented by the following general formula (Z-2). When x is 2, Z has a structure represented by the following general formula (Z-1). In the following general formulas (Z-1) and (Z-2), * represents the bonding site with the O atom in general formula (II).

[0014]

[0015] 2. R in general formula (II) ２ is an alkyl group having a branched structure and having 6 to 30 carbon atoms.

[0016] 3. The near-infrared absorbing composition according to item 1 or 2, further comprising the following component (C) and component (D): Component (C): a compound having a structure represented by the following general formula (III) or (IV): General formula (III) (R ３ O-) ４－ｍ Ti(-O-R ４ -OH) ｍ General formula (IV) (R ３ O-) ４－ｍ Ti(-OCOR ５ ) m [In general formulas (III) and (IV), m represents an integer of 1 to 4. R ４ represents an alkylene group having 1 to 30 carbon atoms, which may further have a substituent. ３ and R ５ each independently represents an alkyl group having 1 to 30 carbon atoms, and may further have a substituent.] Component (D): A compound having a structure represented by the following general formula (V). General formula (V): R ６ - (CH ２ ) ｍ -Si(-CH ３ ) ｎ (-OR ７ ) ３－ｎ [In general formula (V), R ６represents a vinyl group, a styryl group, an acryloxy group, a methacryloxy group, a mercapto group, an epoxy group, an epoxycyclohexyl group, or a glycidoxy group, and may further have a substituent. ７ represents an alkyl group having 1 to 3 carbon atoms, m represents an integer of 0 to 8, and n is 0 or 1.

[0017] 4. The polar term δ of the Hansen solubility parameter of the solvent Ｐ The value of is in the range of 3 to 6, and the hydrogen bond term δ Ｈ 3. The near-infrared absorbing composition according to item 1 or 2, wherein the value of

[0018] 5. The near-infrared absorbing composition according to item 3, wherein the content of the component (C) is within a range of 1 to 30 parts by mass per 100 parts by mass of the component (A).

[0019] 6. The near-infrared absorbing composition according to item 3, wherein the content of the component (D) is within a range of 1 to 30 parts by mass per 100 parts by mass of the component (A).

[0020] 7. The near-infrared absorbing composition according to item 1 or 2, wherein the solvent is cyclopentyl methyl ether or 4-methyltetrahydropyran.

[0021] 8. A near-infrared absorbing cured film comprising a cured product of the near-infrared absorbing composition according to item 1.

[0022] 9. An optical member comprising a cured product of the near-infrared absorbing composition according to item 1.

[0023] The above-mentioned means of the present invention can provide a near-infrared absorbing composition having excellent storage stability, a near-infrared absorbing cured film using the same having excellent moist heat resistance and anti-fogging properties, and an optical component.

[0024] The mechanism by which the effects of the present invention are exhibited or the mechanism of action is not clear, but is presumed to be as follows: In the following, the "near-infrared absorbing composition" will also be referred to simply as the "composition," and the "near-infrared absorbing cured film" will also be referred to simply as the "cured film."

[0025] In a composition containing a copper phosphonate complex as a near-infrared absorbing agent, a phosphate ester compound functions effectively as a dispersant for the copper phosphonate complex. However, if the structure of the phosphate ester compound contains a hydrophilic moiety, it is presumed that the storage stability of the near-infrared absorbing composition will be reduced. In addition, the hydrophilic moiety has a high affinity for water molecules. Therefore, it is presumed that the moist heat resistance and anti-fogging properties of a cured film formed using the near-infrared absorbing composition will be reduced.

[0026] The near-infrared absorbing composition of the present invention can improve the storage stability of the near-infrared absorbing composition by selecting a specific phosphate ester with a controlled hydrophilic moiety as a dispersant. Furthermore, a cured film formed using the composition contains the specific phosphate ester with a controlled hydrophilic moiety. This is presumably effective in improving the moist heat resistance and anti-fogging properties of the cured film.

[0027] Schematic cross-sectional view showing an example of the configuration of a near-infrared cut filter. Schematic cross-sectional view showing an example of the configuration of an image sensor for a solid-state imaging device. Schematic cross-sectional view showing an example of the configuration of a camera module.

[0028] The near-infrared absorbing composition of the present invention is characterized by containing the above-mentioned component (A), component (B), and a solvent. This characteristic is a technical characteristic common to or corresponding to the following embodiments.

[0029] In an embodiment of the present invention, R of a compound having a structure represented by the general formula (II) ２ Preferably, the alkyl group has a branched structure and has 6 to 30 carbon atoms. This enhances the effect of component (B) as a dispersant, and further improves the storage stability of the composition.

[0030] In an embodiment of the present invention, the composition preferably contains the above-mentioned component (C) and component (D), thereby improving the storage stability of the composition and improving the moist heat resistance of the cured film.

[0031] In an embodiment of the present invention, the polar term δ of the Hansen solubility parameter of the solvent Ｐ The value of is in the range of 3 to 6, and the hydrogen bond term δ ＨIt is preferable that the value of is within the range of 3 to 6. This allows the composition to be dispersed in an appropriate state, and the storage stability of the composition is further improved.

[0032] In an embodiment of the present invention, the content of the component (C) is preferably within a range of 1 to 30 parts by mass per 100 parts by mass of the component (A), which provides a good balance between the storage stability of the composition and the moist heat resistance of the cured film.

[0033] In an embodiment of the present invention, the content of the component (D) is preferably within a range of 1 to 30 parts by mass per 100 parts by mass of the component (A), which provides a good balance between the storage stability of the composition and the moist heat resistance of the cured film.

[0034] In an embodiment of the present invention, the solvent is preferably cyclopentyl methyl ether or 4-methyltetrahydropyran, which allows the composition to be dispersed in an appropriate state and further improves the storage stability of the composition.

[0035] The near-infrared absorbing cured film of the present invention is characterized by containing a cured product of the near-infrared absorbing composition of the present invention. This allows the effects of the present invention to be realized and the problems to be solved. The optical member of the present invention is characterized by containing a cured product of the near-infrared absorbing composition of the present invention. This allows the effects of the present invention to be realized and the problems to be solved.

[0036] The present invention, its components, and modes and aspects for carrying out the present invention will be described in detail below. In this application, the symbol "to" is used to mean that the numerical values ​​before and after it are included as lower and upper limits.

[0037] 1. Overview of Near-Infrared Absorbing Composition The near-infrared absorbing composition is characterized by containing a component (A) that is a near-infrared absorbing compound, a component (B) that is a dispersant, and a solvent.

[0038] In this specification, "near infrared" refers to light in the wavelength range of 700 to 2500 nm. "Near infrared absorbing" refers to having a maximum absorption wavelength in the wavelength range of 700 to 2500 nm.

[0039] 2. Constitution of near-infrared absorbing composition The near-infrared absorbing composition contains a component (A) which is a near-infrared absorbing compound, a component (B) which is a dispersant, and a solvent. In addition, the near-infrared absorbing composition may contain a component (C) which is a Ti compound, a component (D) which is a Si compound, an organic dye, an ultraviolet absorber, other additives, etc.

[0040] The near-infrared absorbing composition preferably further contains a Ti compound (component (C)) and a Si compound (component (D)). By containing these, the storage stability of the composition and the moist heat resistance of the cured film can be both achieved. The mechanism of their manifestation or action is not clear, but is presumed to be as follows.

[0041] When the composition contains the Ti compound component (C), a crosslinked structure of the Ti compound is formed in the cured film formed using the composition. As a result, water molecules are less likely to penetrate into the cured film, improving the moist heat resistance. However, if the Ti compound is contained alone in the composition, a crosslinked structure of the Ti compound is formed in the composition, reducing the dispersibility and storage stability of the composition. Therefore, the Ti compound is contained in the composition in combination with the Si compound component (D). This allows the Si compound and the solvent to interact, suppressing the crosslinking action of the Ti compound in the composition and preventing a decrease in the storage stability of the composition. Note that the solvent is removed when the composition is used to form a cured film. Therefore, the interaction between the Si compound and the solvent is eliminated, allowing the suppressed crosslinking action of the Ti compound to be expressed, presumably improving the moist heat resistance of the cured film.

[0042] It is presumed that the storage stability of the composition is improved not only by suppressing the crosslinking action of the Ti compound but also by the interaction of components (A), (B), (C), (D), and the solvent. It is also presumed that the crosslinked structure formed in the cured film is due to the action of not only the Ti compound but also the Si compound.

[0043] (1) Component (A) which is a near-infrared absorbing compound Component (A) which is a near-infrared absorbing compound is a copper complex in which a compound having a structure represented by the following general formula (I) is coordinated. The compound having the structure represented by the following general formula (I) is a phosphonic acid compound. That is, component (A) is a phosphonic acid copper complex. Component (A) is a near-infrared absorbing compound and has a maximum absorption wavelength in the wavelength range of 700 to 2500 nm.

[0044]

[0045] [In general formula (I), R １ is an alkyl group having 1 to 20 carbon atoms, which may further have a substituent.

[0046] R １ The alkyl group having 1 to 20 carbon atoms, represented by the formula (I), may have a linear or branched structure. Examples of the alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, an n-hexyl group, a 2-ethylhexyl group, an n-octyl group, a 2-butyloctyl group, a 2-hexyloctyl group, an n-decyl group, an n-dodecyl group, and a 2-hexyldecyl group.

[0047] R １ Examples of the substituent that may be possessed by include an alkyl group (for example, a methyl group, an ethyl group, a trifluoromethyl group, an isopropyl group, etc.), an alkoxy group (for example, a methoxy group, an ethoxy group, etc.), a halogen atom (for example, a fluorine atom, etc.), a cyano group, a nitro group, a dialkylamino group (for example, a dimethylamino group, etc.), and a trialkylsilyl group (for example, a trimethylsilyl group, etc.).

[0048] Among them, R １ It is more preferable that the alkyl group has 1 to 4 carbon atoms, since this can achieve both near-infrared absorption and visible light transmittance.

[0049] R １Examples of phosphonic acids in which is an alkyl group having 1 to 20 carbon atoms include methylphosphonic acid, ethylphosphonic acid, propylphosphonic acid, butylphosphonic acid, pentylphosphonic acid, hexylphosphonic acid, heptylphosphonic acid, octylphosphonic acid, nonylphosphonic acid, and decylphosphonic acid. Among these, propylphosphonic acid or butylphosphonic acid is preferred. Phosphonic acids can be synthesized with reference to known methods described in, for example, JP-A Nos. 2016-94512 and 2016-124903. Commercially available phosphonic acids may also be used.

[0050] The phosphonic acid copper complex as component (A) may coordinate at least one phosphonic acid molecule. The phosphonic acid copper complex may also coordinate with multiple types of phosphonic acid molecules having different alkyl groups. Furthermore, the phosphonic acid copper complex may also coordinate with a component other than a phosphonic acid molecule.

[0051] The structure of the phosphonic acid copper complex as component (A) is represented, for example, by the following general formula (IC).

[0052]

[0053] R in the above general formula (IC) １ represents R in general formula (I). １ Among the hydroxy groups of phosphonic acid, the hydroxy group directly bonded to the phosphorus atom is called a "reactive hydroxy group." In general formula (IC), each oxygen atom of the two reactive hydroxy groups coordinates with the same copper ion to form a copper complex.

[0054] The form of the phosphonate copper complex is not limited to this. The component (A) contained in the near-infrared absorbing composition may be a single type or a combination of two or more types. In the near-infrared absorbing composition, the phosphonate copper complex is mainly present in the form of particles.

[0055] The content of component (A) in the near-infrared absorbing composition is preferably within the range of 3 to 40% by mass, and more preferably within the range of 10 to 30% by mass. When the content is 3% by mass or more, a thick cured film is easily formed. When the content is 10% by mass or more, a thick cured film is more easily formed. When the content is 40% by mass or less, aggregation of the phosphonate copper complex particles and an increase in the viscosity of the composition can be suppressed, and the storage stability of the composition is good. When the content is 30% by mass or less, the storage stability of the composition is even better.

[0056] From the viewpoint of spectroscopic properties, it is preferable that the fine particles of the phosphonate copper complex are uniformly dispersed when a cured film is formed. Therefore, it is preferable that the particle size of the phosphonate copper complex in the composition (dispersion liquid) is small. The average particle size of the phosphonate copper complex in the composition is preferably 200 nm or less, more preferably 100 nm or less, and even more preferably 80 nm or less. The average particle size of the phosphonate copper complex can be measured by dynamic light scattering using, for example, a zeta potential / particle size measurement system "ELSZ-1000ZS" (manufactured by Otsuka Electronics Co., Ltd.).

[0057] (2) Component (B) as a Dispersant Component (B) is a compound having a structure represented by the following general formula (II), and is a phosphate ester compound. Component (B) exerts the effect of forming small nano-sized particles when the copper phosphonate complex particles are formed. Component (B) also contributes to maintaining the dispersibility of the copper phosphonate complex particles in the medium.

[0058] General formula (II) Z(-OR ２ ) ｘ

[0059] [In general formula (II), R ２represents an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 1 to 30 carbon atoms, or an aryl group having 6 to 30 carbon atoms. x represents 1 or 2. When x is 1, Z has a structure represented by the following general formula (Z-2). When x is 2, Z has a structure represented by the following general formula (Z-1). In the following general formulas (Z-1) and (Z-2), * represents the bonding site with the O atom in general formula (II).

[0060]

[0061] R ２ The alkyl group having 1 to 30 carbon atoms, represented by the formula (I), may be linear or branched. Examples of the alkyl group having 1 to 30 carbon atoms include the following. Examples of the linear alkyl group include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, an n-tridecyl group, an n-tetradecyl group, an n-hexadecyl group, an n-octadecyl group (an n-stearyl group), an n-eicosyl group, an n-docosyl group, an n-tetracosyl group, an n-hexacosyl group, an n-octacosyl group, and an n-triacontyl group.

[0062] Examples of branched alkyl groups include an isopropyl group, a sec-butyl group, a tert-butyl group, an isohexyl group, a 2-ethylhexyl group, a 3,7-dimethyloctyl group, a 2-butyloctyl group, an isododecyl group, an isotridecyl group, a 2-hexyloctyl group, a 2-methyltridecyl group, a 2-methyltetradecyl group, a 2-methylpentadecyl group, a 2-hexyldecyl group, a 2-methylhexadecyl group, a 2-octyldecyl group, a 2-hexyldodecyl group, a 2-methylheptadecyl group, an isostearyl group, a 2-methyloctadecyl group, a 2-octyldodecyl group, a 2-decyltetradecyl group, a 2-dodecyltridecyl group, a 2-dodecyltetradecyl group, a 2-dodecylhexadecyl group, and a 2-tetradecylhexadecyl group.

[0063] R ２ The alkenyl group having 1 to 30 carbon atoms represented by the formula (R) may be linear or branched. ２Examples of the alkenyl group having 1 to 30 carbon atoms represented by the formula (I) include ethenyl group (vinyl group), propenyl group, butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, nonenyl group, decenyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, oleyl group, and linoleyl group. ２ The alkenyl group having 1 to 30 carbon atoms represented by the formula (I) is preferably a dodecenyl group, an oleyl group, or a linoleyl group.

[0064] R ２ Examples of the aryl group having 6 to 30 carbon atoms represented by the formula (I) include a phenyl group, a tolyl group, a xylyl group, a mesityl group, a naphthyl group, an anthryl group, an azulenyl group, an acenaphthenyl group, a fluorenyl group, a phenanthryl group, an indenyl group, a pyrenyl group, and a biphenylyl group. ２ The aryl group having 6 to 30 carbon atoms represented by the formula (I) is preferably a phenyl group, a naphthyl group, a fluorenyl group, a phenanthryl group or a biphenylyl group.

[0065] In general formula (II), R ２ is preferably an alkyl group having a branched structure and a carbon number of 6 to 30. This improves the dispersibility and storage stability of the phosphonate copper complex in the composition, and allows the phosphonate copper complex to be compatible in a cured film formed using the composition.

[0066] R ２Examples of alkyl groups having a branched structure and 6 to 30 carbon atoms, represented by the formula (I), include a 2-ethylhexyl group, a 3,7-dimethyloctyl group, a 2-butyloctyl group, an isododecyl group, an isotridecyl group, a 2-hexyloctyl group, a 2-methyltridecyl group, a 2-methyltetradecyl group, a 2-methylpentadecyl group, a 2-hexyldecyl group, a 2-methylhexadecyl group, a 2-octyldecyl group, a 2-hexyldodecyl group, a 2-methylheptadecyl group, an isostearyl group, a 2-methyloctadecyl group, a 2-octyldodecyl group, a 2-decyltetradecyl group, a 2-dodecyltridecyl group, a 2-dodecyltetradecyl group, a 2-dodecylhexadecyl group, a 2-tetradecylhexadecyl group, and a 2-tetradecyloctadecyl group.

[0067] The compound having the structure represented by general formula (II) is a diester when x is 2, i.e., Z is formula (Z-1), and is a monoester when x is 1, i.e., Z is formula (Z-2). Component (B) may be either a diester or a monoester, but a mixture of a diester and a monoester is preferred. In component (B), the mixing ratio of the diester and the monoester, i.e., the molar ratio of the diester to the total amount of the diester and the monoester, is preferably within the range of 30 to 95%.

[0068] Specific examples of component (B) are shown in Tables I and II below. Note that component (B) shown in Tables I and II below is a mixture of diester and monoester compounds having a structure represented by general formula (II). However, the compound having a structure represented by general formula (II) according to the present invention is not limited to these.

[0069]

[0070]

[0071] Exemplary mixture II-1 will be specifically described. Exemplary mixture II-1 is a mixture of a compound (diester) in which Z is represented by formula (Z-1) and a compound (monoester) in which Z is represented by formula (Z-2).

[0072] A compound (diester) in which Z is formula (Z-1) is represented, for example, by the structure of the following exemplary compound II-1-1. A compound (monoester) in which Z is formula (Z-2) is represented, for example, by the structure of the following exemplary compound II-1-2.

[0073]

[0074]

[0075] In Exemplary Mixture II-1, the molar ratio of the compound (diester) in which Z is represented by Formula (Z-1) is 50%. That is, Exemplary Mixture II-1 contains Exemplary Compound II-1-1 and Exemplary Compound II-1-2 in the same molar amounts.

[0076] Compounds having a structure represented by general formula (II) can be synthesized by referring to the methods described in the following documents, for example: JP 2005-255608 A JP 2015-000396 A JP 2015-000970 A JP 2015-178072 A JP 2015-178073 A Japanese Patent No. 4422866 A International Publication No. 2019-221061

[0077] The near-infrared absorbing composition may contain one or more types of component (B). That is, the component (B) may be composed of, for example, one of the above-mentioned exemplified mixtures, or may be composed of multiple types of the above-mentioned exemplified mixtures.

[0078] The content of the component (B) is preferably within a range of 40 to 80 parts by mass, and more preferably within a range of 50 to 70 parts by mass, relative to 100 parts by mass of the component (A), which makes it possible to better achieve both the dispersibility and storage stability of the near-infrared absorbing composition and the moist heat resistance of the cured film.

[0079] When the proportion of component (B) is low, the proportion of component (A), which is effective in absorbing near-infrared rays, increases, resulting in good near-infrared absorption. Furthermore, the phosphate ester compound (component (B)) tends to become cloudy in high-temperature, high-humidity environments. Therefore, by reducing the proportion of component (B), the moist heat resistance of the cured film is improved. It is preferable to reduce the content of component (B) as much as possible within a range that maintains the dispersibility of the phosphonate copper complex particles.

[0080] (3) Component (C) Component (C) is a compound having a structure represented by the following general formula (III) or (IV), and is a Ti compound.

[0081] General formula (III) (R ３ O-) ４－ｍ Ti(-O-R ４ -OH) ｍ General formula (IV) (R ３ O-) ４－ｍ Ti(-OCOR ５ ) ｍ

[0082] In general formulas (III) and (IV), m represents an integer of 1 to 4. ４ represents an alkylene group having 1 to 30 carbon atoms, which may further have a substituent. ３ and R ５ each independently represents an alkyl group having 1 to 30 carbon atoms, which may further have a substituent.

[0083] R ３ and R ５ The alkyl group having 1 to 30 carbon atoms, represented by the formula (I), may be linear or branched. Examples of the alkyl group having 1 to 30 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, an n-hexyl group, a 2-ethylhexyl group, an n-octyl group, a 2-butyloctyl group, a 2-hexyloctyl group, an n-decyl group, an n-dodecyl group, a 2-hexyldecyl group, an n-stearyl group, and an isostearyl group. An alkyl group having 6 to 20 carbon atoms is preferred.

[0084] R ４The alkylene group having 1 to 30 carbon atoms, represented by the formula (I), may be linear or branched. Examples of the alkylene group having 1 to 30 carbon atoms include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, an n-butylene group, a tert-butylene group, an n-hexylene group, a 2-ethylhexylene group, an n-octylene group, a 2-butyloctylene group, a 2-hexyloctylene group, an n-decylene group, an n-dodecylene group, a 2-hexyldecylene group, an n-stearylene group, and an isostearylene group. An alkylene group having 6 to 20 carbon atoms is preferred.

[0085] R ３ , R ４ and R ５ Examples of the substituent that each of the groups may have include an alkyl group (e.g., a methyl group, an ethyl group, a trifluoromethyl group, an isopropyl group, etc.), an alkoxy group (e.g., a methoxy group, an ethoxy group, etc.), a halogen atom (e.g., a fluorine atom, etc.), a cyano group, a nitro group, a dialkylamino group (e.g., a dimethylamino group, etc.), a trialkylsilyl group (e.g., a trimethylsilyl group, etc.), etc.

[0086] The compound having the structure represented by general formula (III) is more preferably a compound that forms a chelate structure. Examples of such compounds include the following titanium chelate compounds. Examples of titanium chelate compounds include titanium ethylene dioleate, titanium propylene dioleate, titanium butylene dioleate, titanium pentylene dioleate, titanium hexylene dioleate, titanium-2-ethyl-1,3-hexylene dioleate, and titanium octylene dioleate. Of these, titanium octylene dioleate is preferred.

[0087] Specific examples of the compound having the structure represented by general formula (III) are shown below, but the compound having the structure represented by general formula (III) according to the present invention is not limited to these.

[0088]

[0089]

[0090] Compounds having a structure represented by general formula (III) are also available as commercially available products, such as "Orgatix (registered trademark) TC245" (manufactured by Matsumoto Fine Chemical Co., Ltd.).

[0091] The compound having the structure represented by general formula (IV) is preferably a compound that forms an acylate structure. Examples of such compounds include the following titanium acylate compounds. Examples of titanium acylate compounds include titanium caprylate, titanium caprate, titanium laurate, titanium myristylates, titanium palmitates, titanium stearate, and titanium isostearate. Of these, titanium isostearate is preferred.

[0092] Specific examples of compounds having a structure represented by general formula (IV) are shown below, but the compounds having a structure represented by general formula (IV) according to the present invention are not limited to these.

[0093]

[0094] Compounds having a structure represented by general formula (IV) are also available as commercially available products, such as "Orgatix (registered trademark) TC-800" (manufactured by Matsumoto Fine Chemical Co., Ltd.).

[0095] The compound having the structure represented by general formula (III) or general formula (IV) can be obtained by referring to the synthesis method described in, for example, JP-A-2011-219704.

[0096] The near-infrared absorbing composition may contain one or more types of component (C).

[0097] The content of the component (C) is preferably in the range of 1 to 30 parts by mass, and more preferably in the range of 3 to 20 parts by mass, per 100 parts by mass of the component (A). This allows for a better balance between the storage stability of the near-infrared absorbing composition and the moist heat resistance of the cured film. When the content of the component (C) is 1 part by mass or more per 100 parts by mass of the component (A), the moist heat resistance of the cured film is improved. When the content of the component (C) is 30 parts by mass or less per 100 parts by mass of the component (A), the storage stability of the near-infrared absorbing composition is improved.

[0098] (4) Component (D) Component (D) is a compound having a structure represented by the following general formula (V), and is a Si compound.

[0099] The compound having the structure represented by general formula (V) suppresses the crosslinking action of the Ti compound in the near-infrared absorbing composition, and improves the storage stability of the near-infrared absorbing composition.In addition, when forming a cured film, the crosslinking action of the Ti compound and the Si compound exerts a synergistic effect.Therefore, when the Ti compound and the Si compound are used in combination, the wet heat resistance of the cured film is improved compared to when the Ti compound is used alone.

[0100] General formula (V) R ６ - (CH ２ ) ｍ -Si(-CH ３ ) ｎ (-OR ７ ) ３－ｎ

[0101] [In general formula (V), R ６ represents a vinyl group, a styryl group, an acryloxy group, a methacryloxy group, a mercapto group, an epoxy group, an epoxycyclohexyl group, or a glycidoxy group, and may further have a substituent. ７ represents an alkyl group having 1 to 3 carbon atoms, m represents an integer of 0 to 8, and n is 0 or 1.

[0102] Among them, R ６ is preferably an acryloxy group or a methacryloxy group, which further improves the storage stability of the near-infrared absorbing composition and the moist heat resistance of the cured film.

[0103] Specific examples of compounds having a structure represented by general formula (V) are shown below, but the compounds having a structure represented by general formula (V) according to the present invention are not limited to these.

[0104]

[0105]

[0106] Compounds having a structure represented by general formula (V) are also available as commercially available products. Examples of commercially available products include "KBM-1003, KBE-1003, KBM-1083, KBM-303, KBM-402, KBM-403, KBE-402, KBE-403, KBM-4803, KBM-1403, KBM-502, KBM-503, KBE-502, KBE-503, KBM-5803, KBM-5103, KBM-802, and KBM-803" (all manufactured by Shin-Etsu Chemical Co., Ltd.).

[0107] The near-infrared absorbing composition may contain one or more types of component (D).

[0108] The compound having the structure represented by general formula (V) can be obtained by referring to the synthesis method described in, for example, JP-A-9-157280.

[0109] The content of component (D) is preferably in the range of 1 to 30 parts by mass, and more preferably in the range of 3 to 20 parts by mass, per 100 parts by mass of component (A). This allows both the storage stability of the composition and the moist heat resistance of the cured film to be achieved. When the content of component (D) is 30 parts by mass or less per 100 parts by mass of component (A), the moist heat resistance of the cured film is improved. When the content of component (D) is 1 part by mass or more per 100 parts by mass of component (A), the storage stability of the composition is improved.

[0110] (5) Solvent The solvent that can be used in the near-infrared absorbing composition is not particularly limited. Examples of the solvent include hydrocarbon solvents.

[0111] Among them, the solvent has a polarity term δ of the Hansen solubility parameter Ｐ is preferably in the range of 3 to 6, and the hydrogen bond term δ ＨIt is preferable that the value of is in the range of 3 to 6.

[0112] The Hansen solubility parameter (HSP) is a value that indicates the solubility of a substance. The HSP is a solubility parameter introduced by Hildebrand, expressed as a function of the dispersion term δ Ｄ , polar term δ Ｐ , hydrogen bond term δ Ｈ It is divided into three components and represented in three-dimensional space.

[0113] Dispersion term δ Ｄ represents the energy derived from dispersion forces. Ｐ represents the energy derived from polar forces. The hydrogen bond term δ Ｈ represents the energy derived from the hydrogen bonding force. Ｄ , δ Ｐ and δ Ｈ The unit is [MPa １／２ ].

[0114] The definition and calculation method of HSP are described in the following literature: "Hansen Solubility Parameters: A User's Handbook" by Charles M. Hansen (CRC Press, 2007).

[0115] Compounds with similar HSP vectors can be judged to have high solubility. The similarity of the vectors can be determined by the HSP distance. HSP can be an indicator not only of solubility but also of how easily a substance exists in another substance, i.e., dispersibility.

[0116] The HSP of various solvents used in this specification is a value determined using the following commercially available computer software: "Hansen Solubility Parameters in Practice (HSPiP)"

[0117] The solvent is not particularly limited, but preferably satisfies the above requirements for HSP, and among these, an ether solvent is preferred.

[0118] The solvent preferably has a cycloalkyl group or a cycloether group from the viewpoint of dispersibility. The cycloalkyl group is more preferably a cyclopentyl group or a cyclohexyl group from the viewpoint of dispersibility. The cycloether group is more preferably a tetrahydrofuran group or a tetrahydropyran group from the viewpoint of dispersibility.

[0119] In this specification, "dispersibility" refers to the performance or function of a dispersion medium that disperses various components constituting the near-infrared absorbing composition in an appropriate state in the near-infrared absorbing composition. In this specification, "storage stability" refers to the performance or function of maintaining the dispersion state of various components constituting the near-infrared absorbing composition in an appropriate state without or with little change over time, due to changes in environmental conditions, etc.

[0120] The solvent is more preferably cyclopentyl methyl ether or 4-methyltetrahydropyran, and particularly preferably cyclopentyl methyl ether, which can disperse the near infrared absorbing composition in an appropriate state and further improve the storage stability of the near infrared absorbing composition.

[0121] Specific examples of solvents are shown in Table III, but the solvents according to the present invention are not limited to these.

[0122]

[0123] The boiling point of the solvent is preferably within the range of 80 to 150° C. from the viewpoint of preventing cracks during the formation of a cured film.

[0124] The near-infrared absorbing composition may contain one or more solvents.

[0125] The content of the solvent is preferably within a range of 50 to 95% by mass relative to the total mass of the near-infrared absorbing composition from the viewpoints of dispersibility and storage stability.

[0126] 3. Near-infrared-absorbing cured film The near-infrared-absorbing cured film is characterized by containing a cured product of a near-infrared-absorbing composition. The near-infrared-absorbing cured film is suitable for constituting the following members and parts for, for example, CCDs, CMOSs, or other light-receiving elements. Examples of members and parts include visibility correction members, photometric members, heat-absorbing members, composite optical filters, lens members (eyeglasses, sunglasses, goggles, optical systems, optical waveguides), fiber members (optical fibers), noise-cutting members, display covers or display filters such as plasma display front panels, projector front panels, light source heat-cutting members, color correction members, illumination brightness adjustment members, optical elements (light amplifiers, wavelength conversion elements, etc.), optical communication functional devices such as Faraday elements and isolators, and optical disc elements.

[0127] The near-infrared absorbing cured film can be produced, for example, by the following procedure. First, a resin material is dissolved in a near-infrared absorbing composition (dispersion) to prepare a coating liquid for forming a cured film. The coating liquid is applied onto a substrate by a wet coating method. The coating film is cured by performing a predetermined heat treatment or the like.

[0128] Examples of the wet coating method include a drop casting method, a dispenser method, a spin coater method, a slit spin coater method, a slit coater method, a screen printing method, an applicator method, and an inkjet method.

[0129] The thickness of the near-infrared absorbing cured film is preferably in the range of 10 to 500 μm, and more preferably in the range of 10 to 300 μm.

[0130] The resin material preferably has optical transparency to visible light and near-infrared light, and is capable of dispersing fine particles of the near-infrared absorbing composition.

[0131] The component (A), which is a copper phosphonate complex, is a substance with relatively low polarity and disperses well in hydrophobic materials. Therefore, the resin material for forming the cured film is preferably a resin material having a polysiloxane structure, or a resin material having an acrylic group, an epoxy group, or a phenyl group. Among these, resins having a polysiloxane structure are particularly preferred because they are resistant to thermal decomposition, have high optical transparency to visible light and near-infrared light, and are also highly heat-resistant.

[0132] Examples of resin materials having a polysiloxane structure include "KR-211, KR-212, KR-216, KR-251, KR-255, KR-2621-1, KR-300, and KR-311" (all manufactured by Shin-Etsu Chemical Co., Ltd.). Examples of resin materials having epoxy groups include "KJC-X5" (manufactured by Shin-Etsu Chemical Co., Ltd.) and "EpiFine (registered trademark) series" (manufactured by KISCO Corporation).

[0133] As the resin material having an acrylic group, a (meth)acrylic acid ester-based monomer is preferred. Examples of the (meth)acrylic acid ester-based monomer include alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, and n-butyl (meth)acrylate. Examples of the (meth)acrylic acid ester-based monomer include modified (meth)acrylates such as phenoxy (meth)acrylate, and polyfunctional (meth)acrylates such as trimethylolpropane tri(meth)acrylate and pentaerythritol tetra(meth)acrylate.

[0134] A polymer (resin polymer) may be used as the resin material for forming the cured film. Examples of the polymer (resin polymer) include polymers of (meth)acrylic acid ester compounds, polymers of aromatic vinyl compounds (styrene, α-methylstyrene, methoxystyrene, divinylbenzene, etc.), and cycloolefin polymers (COP). In this specification, the term "(meth)acrylic group" refers to both a "methacrylic group" and an "acrylic group."

[0135] The coating liquid for forming a cured film may contain other additives to the extent that the intended effects of the present invention are not impaired. Examples of other additives include sensitizers, crosslinking agents, curing accelerators, polymerization initiators, fillers, thermal curing accelerators, thermal polymerization inhibitors, plasticizers, etc. The coating liquid may further contain other components such as auxiliary agents. Examples of auxiliary agents include conductive particles, fillers, antifoaming agents, flame retardants, leveling agents, release accelerators, antioxidants, fragrances, surface tension modifiers, chain transfer agents, surface treatment agents, etc. By appropriately adding these components to the coating liquid, the stability of the cured film, film physical properties, etc. can be adjusted.

[0136] 4. Spectral Properties of Near-Infrared Absorbing Composition (Dispersion) The near-infrared absorbing composition preferably has an average spectral transmittance in the wavelength region of 450 to 600 nm of 70% or more, more preferably 80% or more, and even more preferably 90% or more. The average spectral transmittance here is a value measured after diluting the near-infrared absorbing composition with a solvent so that the maximum spectral transmittance in the wavelength region of 850 to 1000 nm is 10%. An average spectral transmittance of 70% or more allows the cured film to have a high visible light transmittance.

[0137] As a device for measuring the spectral transmittance, for example, a spectrophotometer "V-570" (manufactured by JASCO Corporation) can be used.

[0138] 5. Spectral Properties of Near-Infrared Absorptive Cured Film From the viewpoint of visible light transmittance, it is preferable that the near-infrared absorptive cured film have an average spectral transmittance of 80% or more in the wavelength region of 450 to 600 nm. From the viewpoint of near-infrared absorptivity, it is preferable that the near-infrared absorptive cured film have an average spectral transmittance of 10% or less in the wavelength region of 850 to 1000 nm. From the viewpoint of near-infrared absorptivity, it is preferable that the near-infrared absorptive cured film have an average spectral transmittance of 1% or less in the wavelength region of 850 to 1080 nm.

[0139] The wavelength at which the spectral transmittance decreases with increasing wavelength in the 600 to 700 nm wavelength region, and the wavelength at which the spectral transmittance is 50% in the 600 to 800 nm wavelength region, is defined as the "cutoff wavelength." The cutoff wavelength of the near-infrared absorbing cured film for light incident on the surface at an incident angle of 0° is preferably within the range of 600 to 750 nm. This allows the cured film to have good near-infrared absorbency.

[0140] 6. Optical Component The optical component of the present invention is characterized by containing a cured product of the near-infrared absorbing composition. The near-infrared absorbing cured film of the present invention can be used as various optical components or parts. Below, examples of application of the near-infrared absorbing composition or the near-infrared absorbing cured film as optical components or parts will be described.

[0141] (1) Near-infrared cut filter The optical member of the present invention is, for example, a near-infrared cut filter. The near-infrared cut filter includes, for example, a transparent dielectric substrate and a near-infrared absorbing layer on at least one surface of the substrate. The near-infrared absorbing layer is a cured product of the near-infrared absorbing composition of the present invention.

[0142] It is preferable to further provide a dielectric multilayer film on at least one surface of the transparent dielectric substrate, from the viewpoint of enabling more flexible adjustment of the spectral characteristics of the near-infrared cut filter. The near-infrared absorbing layer and the dielectric multilayer film may be provided in contact with the transparent dielectric substrate, or may be provided via another intermediate layer.

[0143] Fig. 1 is a schematic cross-sectional view showing an example of the configuration of a near-infrared cut filter. The near-infrared cut filter 9 shown in Fig. 1 comprises a near-infrared absorbing layer 22 on one surface of a transparent dielectric substrate 21. The near-infrared cut filter 9 further comprises a dielectric multilayer film 23 on the other surface of the transparent dielectric substrate 21.

[0144] The material of the transparent dielectric substrate is not particularly limited as long as the object of the present invention is achieved. Examples of the transparent dielectric substrate include glass and optical resin. Examples of optical resin include polycarbonate (PC), polymethyl methacrylate (PMMA), cycloolefin polymer (COP), and silicone.

[0145] The thickness of the transparent dielectric substrate is preferably within the range of 0.01 to 1 mm.

[0146] The transparent dielectric substrate is required to transmit visible light, and therefore preferably has an average spectral transmittance of 80% or more in the wavelength range of 450 to 600 nm.

[0147] The near-infrared absorbing cured film of the present invention can be used as the near-infrared absorbing layer. A near-infrared cut filter can be produced by directly forming the near-infrared absorbing cured film as the near-infrared absorbing layer on a transparent dielectric substrate.

[0148] A dielectric multilayer film is a film formed by laminating multiple layers made of materials with different refractive indices, and is used to control the transmittance of each wavelength of light. By combining a dielectric multilayer film with a near-infrared absorbing layer, the spectral characteristics of the near-infrared cut filter can be adjusted more freely.

[0149] The spectral characteristics of the dielectric multilayer film can be adjusted by the thickness and type of material of each layer, such as titanium oxide, silicon oxide, aluminum oxide, zirconium oxide, tantalum pentoxide, niobium pentoxide, lanthanum oxide, yttrium oxide, zinc oxide, zinc sulfide, indium oxide, silica, alumina, lanthanum fluoride, magnesium fluoride, and sodium aluminum hexafluoride.

[0150] A near-infrared cut filter having a dielectric multilayer film can be produced by laminating each dielectric layer on a transparent dielectric substrate by, for example, vacuum deposition, chemical vapor deposition, sputtering, etc.

[0151] A near-infrared cut filter having a dielectric multilayer film can also be produced by laminating a separately prepared dielectric multilayer film to a transparent dielectric substrate with an adhesive.

[0152] (2) Image Sensor for Solid-State Imaging Device The near-infrared cut filter can be provided in an image sensor for a solid-state imaging device. An image sensor for a solid-state imaging device is a component mainly composed of a solid-state imaging device substrate equipped with a light-receiving element. In addition to the near-infrared cut filter, the image sensor for a solid-state imaging device may also include a planarizing layer, a glass substrate, etc.

[0153] Fig. 2 is a schematic cross-sectional view showing an example of the configuration of an image sensor for a solid-state imaging device. The image sensor 14 for a solid-state imaging device shown in Fig. 2 includes a solid-state imaging device substrate 10 having a light-receiving element on the light-receiving surface of a silicon substrate, a planarization layer 8 provided on the solid-state imaging device substrate 10, a near-infrared cut filter 9 provided on the planarization layer 8, and a glass substrate 3 (light-transmitting substrate) arranged above the near-infrared cut filter 9. Each component is bonded with an adhesive 2.

[0154] (3) Camera Module The image sensor for a solid-state imaging device can be provided in a camera module, which may be composed of an imaging lens, a lens holder, a light-shielding and electromagnetic shield, etc. in addition to the image sensor for a solid-state imaging device.

[0155] Fig. 3 is a schematic cross-sectional view showing an example of the configuration of a camera module. The camera module 1 shown in Fig. 3 includes a solid-state imaging element image sensor similar to that shown in Fig. 2, a lens holder 5, an imaging lens 4, and a light-shielding and electromagnetic shield 6. As in Fig. 2, the solid-state imaging element image sensor is composed of a solid-state imaging element substrate 10, a planarization layer 8, a near-infrared cut filter 9, and a glass substrate 3. The light-shielding and electromagnetic shield 6 is disposed so as to surround the periphery of the solid-state imaging element image sensor. Each component is bonded with an adhesive 7.

[0156] Furthermore, the camera module 1 is connected to a circuit board 12, which is a mounting board, via solder balls 11 (connecting material), which are connecting members.

[0157] In the camera module 1, incident light L from the outside passes through the imaging lens 4, the glass substrate 3, the near-infrared cut filter 9, and the planarization layer 8 in this order. Thereafter, the incident light L reaches the light receiving element of the solid-state imaging element substrate 10.

[0158] The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. In the following examples, unless otherwise specified, operations were carried out at room temperature (25°C). In the following examples, unless otherwise specified, "%" and "parts" mean "% by mass" and "parts by mass", respectively.

[0159] 1. Preparation of Near-Infrared Absorbing Composition Near-infrared absorbing composition No. 1 was prepared according to the following method.

[0160] (Mixture a) The following compounds and solvent were mixed in the amounts shown below, stirred for 3 hours, and the resulting solution was filtered to remove insoluble matter, to prepare mixture a: Copper (II) acetate monohydrate 18 g Tetrahydrofuran 800 g

[0161] (Mixture b) A mixture was prepared by mixing Exemplary Mixture II-3 with the following solvent in the following amounts. Mixture a was added to this mixture, and the mixture was stirred at room temperature for 30 minutes to prepare Mixture b. Note that Exemplary Mixture II-3 below corresponds to a mixture containing a compound having a structure represented by the above general formula (II). Exemplary Mixture II-3 10 g Tetrahydrofuran 70 g

[0162] (Mixture c) Butylphosphonic acid was mixed with the following solvent in the following amounts to prepare mixture c. Note that butylphosphonic acid corresponds to the compound having the structure represented by the above general formula (I). Butylphosphonic acid 12 g Tetrahydrofuran 70 g

[0163] (Mixture d) Mixture c was added to mixture b while stirring, and then the mixture was stirred at room temperature for 16 hours to prepare mixture d.

[0164] (Mixture e) The entire amount of Mixture d and 300 g of methylcyclohexane were placed in a flask. This mixture was heated within the range of 50 to 100°C and subjected to a solvent removal and acetic acid removal treatment using a rotary evaporator. 300 g of cyclopentyl methyl ether was then added to this mixture. The solvent removal operation using the rotary evaporator was repeated three times. In this way, the solvent was replaced with cyclopentyl methyl ether, and a mixture was prepared so that the concentration of component (A) was 10% by mass. The resulting mixture was designated Mixture e.

[0165] Exemplary Compound III-2 and Exemplary Compound V-10 were mixed in the following amounts in the following solvent. This was added to 100 g of Mixture e and stirred at room temperature for 30 minutes to obtain Near-Infrared Absorbing Composition No. 1. Note that Exemplary Compound III-2 corresponds to the compound having a structure represented by the above general formula (III), and Exemplary Compound V-10 corresponds to the compound having a structure represented by the above general formula (V). Exemplary Compound III-2 1.0 g Exemplary Compound V-10 1.0 g Cyclopentyl methyl ether 10 g

[0166] Near infrared absorbing compositions Nos. 2 to 35 were prepared in the same procedure as for preparing near infrared absorbing composition No. 1, except that the compounds below were changed as shown in Tables V to VII. The exemplary compounds listed in Tables V to VII are the same as the aforementioned exemplary compounds. - Type of compound having a structure represented by general formula (I) - Type of mixture composed of compounds having a structure represented by general formula (II) - Type and amount of compound having a structure represented by general formula (III) or (IV) - Type and amount of compound having a structure represented by general formula (V) - Type of solvent

[0167] Dispersants II-39 to II-41 used in the comparative examples instead of component (B) are as follows. Note that II-39 to II-41 do not fall under the category of mixtures containing a compound having a structure represented by general formula (II) above.

[0168] II-39 A mixture of the following two compounds in a molar ratio of 50%

[0169]

[0170] II-40 A mixture of the following two compounds in a molar ratio of 50%

[0171]

[0172] II-41 A mixture of the following two compounds in a molar ratio of 50%

[0173]

[0174] The values ​​of each component of the Hansen solubility parameters of the solvents used are as follows:

[0175]

[0176] The configuration of each near-infrared absorbing composition is shown in Tables V to VII below. Note that the "content" of the component (C) and the component (D) represents the content [parts by mass] relative to 100 parts by mass of the component (A).

[0177]

[0178]

[0179]

[0180] 2. Evaluation of Near-Infrared Absorbing Composition (1) Evaluation of Dispersibility The dispersibility of the near-infrared absorbing composition was evaluated by measuring the average particle size of particles in the near-infrared absorbing composition. The near-infrared absorbing composition was diluted with toluene to a solids concentration of 0.5% by mass. The average particle size was measured by dynamic light scattering using a zeta potential / particle size measuring system "ELSZ-1000ZS" (manufactured by Otsuka Electronics Co., Ltd.). The average particle size was evaluated according to the following evaluation criteria, and this was used as a measure of dispersibility. The evaluation results are shown in Tables VIII and IX below.

[0181] A: The average particle size is 100 nm or less. B: The average particle size is more than 100 nm and not more than 150 nm. C: The average particle size is more than 150 nm and not more than 200 nm. D: The average particle size is more than 200 nm. A to B were deemed to have no practical problems.

[0182] (2) Evaluation of Storage Stability The storage stability of the near-infrared absorbing composition was evaluated by measuring the change in particle size and viscosity of the near-infrared absorbing composition over time.

[0183] (2.1) Change in particle size The near-infrared absorbing composition was left to stand at room temperature for 7 days. Thereafter, the average particle size of the particles in the near-infrared absorbing composition was measured in the same manner as described above. The average particle size variation rate [%] was calculated from the average particle size before and after standing. The average particle size variation rate [%] was evaluated according to the following criteria. The evaluation results are shown in Tables VIII and IX below. Average particle size variation rate [%] = (|R ２ -R １ | / R １ ) x 100 R １ R: average particle size [nm] of particles in the near infrared absorbing composition before standing ２ : average particle size [nm] of particles in the near infrared absorbing composition after standing

[0184] A: The average particle size fluctuation rate is less than 10%. B: The average particle size fluctuation rate is 10% or more and less than 30%. C: The average particle size fluctuation rate is 30% or more and less than 50%. D: The average particle size fluctuation rate is 50% or more. A to B were deemed to be practically acceptable.

[0185] (2.2) Change in Viscosity The viscosity of the near-infrared absorbing composition was measured. Thereafter, the near-infrared absorbing composition was heated at 45°C for 2 days. After heating, the viscosity of the near-infrared absorbing composition was measured again. The viscosity variation rate [%] was calculated from the viscosity before and after heating. The viscosity variation rate [%] was evaluated according to the following criteria. The evaluation results are shown in Tables VIII and IX below. The viscosity was measured using a vibration viscometer "VM-10A" (manufactured by Sekonic Corporation). Viscosity variation rate [%] = (|η ２ -η １ | / η １ ) × 100 η １ η: Viscosity of near infrared absorbing composition before heating [mPa s] ２ : Viscosity of near-infrared absorbing composition after heating [mPa s]

[0186] A: The viscosity fluctuation rate is less than 10%. B: The viscosity fluctuation rate is 10% or more and less than 30%. C: The viscosity fluctuation rate is 30% or more and less than 50%. D: The viscosity fluctuation rate is 50% or more. A to B were deemed to be no problem in practical use.

[0187] The evaluation results are shown in the following Tables VIII and IX. The evaluation results show that the near-infrared absorbing composition of the present invention is excellent in dispersibility and storage stability.

[0188]

[0189]

[0190] 3. Preparation of near-infrared absorbing cured films The near-infrared absorbing composition and the following resin materials were mixed in the combinations shown in Table IV so that the solid content ratio of the resin materials was 70 mass %. In this way, coating solutions for forming near-infrared absorbing cured films No. 1 to 46 were prepared, respectively.

[0191] Details of the resin materials used are as follows: (Resin material No. 1: Resin material having acrylic groups) A solution in which the following components were mixed in the following proportions: 2-ethylhexyl methacrylate 80% by mass, trimethylolpropane triacrylate 19% by mass, and polymerization initiator "Perbutyl (registered trademark) ND" (manufactured by NOF Corporation) 1.0% by mass.

[0192] (Resin material No. 2: Resin material having a polysiloxane structure) Silicone resin "KR311" (manufactured by Shin-Etsu Chemical Co., Ltd.)

[0193] The coating liquid for forming a near-infrared absorbing cured film was cast-coated onto a glass substrate. The coating amount was adjusted to a thickness such that the maximum spectral transmittance of the cured coating film in the wavelength range of 850 to 1000 nm would be 10%. The glass substrate coated with the coating liquid was pre-baked on a hot plate at 110°C for 2 minutes.

[0194] The composition was then cured by heat treatment on a hot plate. When resin material 1 was used, the heating temperature was 120°C and the heating time was 1 hour. When resin material 2 was used, the heating temperature was 180°C and the heating time was 1 hour. In this way, near-infrared absorbing cured films Nos. 1 to 40 were produced.

[0195] 4. Evaluation of near-infrared absorbing cured film (1) Evaluation of moist heat resistance The average spectral transmittance T of the near-infrared absorbing cured film immediately after preparation in the wavelength range of 400 to 700 nm was ａｖｅ１ The near-infrared absorbing cured film was then left to stand for 1000 hours in an environment of 85°C and 85% RH. The average spectral transmittance T ａｖｅ２ asked for.

[0196] T ａｖｅ１ T for ａｖｅ２ The decrease in the spectral transmittance (T ａｖｅ１ -T ａｖｅ２ The extent of decrease in spectral transmittance was evaluated according to the following criteria, and this was used as a measure of moist heat resistance. The evaluation results are shown in Tables X and XI below.

[0197] A: The decrease in average transmittance is less than 3%. B: The decrease in average transmittance is 3% or more and less than 5%. C: The decrease in average transmittance is 5% or more and less than 10%. D: The decrease in average transmittance is 10% or more. A to B were deemed to be practically acceptable.

[0198] (2) Evaluation of Anti-Fogging Property A water bath at 40°C was prepared. Steam from the water bath was applied only to a predetermined 5 cm x 5 cm area of ​​the near-infrared absorbing cured film, and the time until fogging occurred was measured. The time until fogging occurred was evaluated according to the following criteria, and this was used as a measure of anti-fogging property. The evaluation results are shown in Tables X and XI below.

[0199] A: No fogging for 1 minute 30 seconds or more, and no fluctuation that makes the transmitted image appear blurred. B: No fogging for 30 seconds or more but less than 1 minute 30 seconds, and no fluctuation that makes the transmitted image appear blurred. C: No fogging for 15 seconds or more but less than 30 seconds, and no fluctuation that makes the transmitted image appear blurred. D: Fogging occurs in less than 15 seconds, and the transmitted image cannot be seen. A to B were deemed to be acceptable for practical use.

[0200] The evaluation results are shown in the following Tables X and XI. The evaluation results show that the near-infrared absorbing cured film of the present invention has excellent moist heat resistance and anti-fogging properties.

[0201]

[0202]

[0203] From the above results, it can be confirmed that the near-infrared absorbing composition of the present invention has excellent storage stability and can form a cured film that is excellent in moist heat resistance and anti-fogging properties.

[0204] From the comparison of compositions 2 and 12, it is clear that R ２ However, it can be seen that the dispersibility and storage stability are improved by using an alkyl group having a branched structure and 6 to 30 carbon atoms.

[0205] A comparison of Compositions 1 and 2, or a comparison of Compositions 4 and 5, shows that the inclusion of the above-mentioned components (C) and (D) improves storage stability. Furthermore, a comparison of Cured Films 2 and 4, which are cured products of Compositions 4 and 5, shows that the moist heat resistance is improved.

[0206] Comparison of Compositions 17, 18, 21, and 22 shows that storage stability is improved when the content of component (C) is within the range of 1 to 30 parts by mass per 100 parts by mass of component (A). Furthermore, comparison of the cured products thereof, cured films 21, 22, 25, and 26, shows that moist heat resistance and anti-fogging properties are improved.

[0207] Comparison of Compositions 19, 20, 23, and 24 shows that storage stability is improved when the content of component (D) is within the range of 1 to 30 parts by mass per 100 parts by mass of component (A). Furthermore, comparison of cured films 23, 24, 27, and 28, which are the cured products thereof, shows that moist heat resistance and anti-fogging properties are improved.

[0208] By using the present invention, a near-infrared cut filter having excellent moist heat resistance and anti-fogging properties can be obtained, and a camera module equipped with the near-infrared cut filter has excellent moist heat resistance and anti-fogging properties.

[0209] REFERENCE SIGNS LIST 1 camera module 2 adhesive 3 glass substrate 4 imaging lens 5 lens holder 6 light-shielding and electromagnetic shield 7 adhesive 8 planarizing layer 9 near-infrared cut filter 10 solid-state imaging element substrate 11 solder ball 12 circuit board 14 image sensor for solid-state imaging element 21 transparent dielectric substrate 22 near-infrared absorbing layer 23 dielectric multilayer film

Claims

1. A near-infrared absorbing composition comprising the following component (A) which is a near-infrared absorbing compound, the following component (B) which is a dispersant, and a solvent: Component (A) which is a near-infrared absorbing compound: a copper complex coordinated with a compound having a structure represented by the following general formula (I): [In general formula (I), R １ is an alkyl group having 1 to 20 carbon atoms, which may further have a substituent.] Component (B) which is a dispersant: a compound having a structure represented by the following general formula (II). General formula (II) Z(-O-R ２ )x [In general formula (II), R ２ represents an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 1 to 30 carbon atoms, or an aryl group having 6 to 30 carbon atoms. x represents 1 or 2. When x is 1, Z has a structure represented by the following general formula (Z-2). When x is 2, Z has a structure represented by the following general formula (Z-1). In the following general formulas (Z-1) and (Z-2), * represents a bonding site with the O atom in general formula (II).

2. R in general formula (II) ２ is an alkyl group having a branched structure and having 6 to 30 carbon atoms.

3. The near infrared absorbing composition according to claim 1 or 2, further comprising the following components (C) and (D). Component (C): A compound having a structure represented by the following general formula (III) or (IV). General formula (III) (R ３ O-) ４－ｍ Ti(-O-R ４ -OH) ｍ General formula (IV) (R ３ O-) ４－ｍ Ti(-OCOR ５ ) ｍ In formulas (III) and (IV), m represents an integer of 1 to 4. ４ represents an alkylene group having 1 to 30 carbon atoms, which may further have a substituent. ３ and R ５ R each independently represents an alkyl group having 1 to 30 carbon atoms, and may further have a substituent.] Component (D): A compound having a structure represented by the following general formula (V). General formula (V) R ６ - (CH ２ ) ｍ -Si(-CH ３ ) ｎ (-OR ７ ) ３－ｎ [In general formula (V), R ６ R represents a vinyl group, a styryl group, an acryloxy group, a methacryloxy group, a mercapto group, an epoxy group, an epoxycyclohexyl group, or a glycidoxy group, and may further have a substituent. ７ represents an alkyl group having 1 to 3 carbon atoms, m represents an integer of 0 to 8, and n is 0 or 1.

4. The polar term δ of the Hansen solubility parameter of the solvent Ｐ is in the range of 3 to 6, and the hydrogen bond term δ Ｈ The near infrared absorbing composition according to claim 1 or 2, wherein the value of is within a range of 3 to 6.

5. The near infrared absorbing composition according to claim 3, characterized in that the content of the component (C) is within the range of 1 to 30 parts by mass per 100 parts by mass of the component (A).

6. The near infrared absorbing composition according to claim 3, characterized in that the content of the component (D) is within the range of 1 to 30 parts by mass per 100 parts by mass of the component (A).

7. The near infrared absorbing composition according to claim 1 or 2, characterized in that the solvent is cyclopentyl methyl ether or 4-methyltetrahydropyran.

8. A near infrared absorbing cured film comprising the cured product of the near infrared absorbing composition according to claim 1.

9. An optical component comprising the cured product of the near infrared absorbing composition according to claim 1.

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