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

Abstract

Provided are: a near-infrared-absorbing composition capable of forming a cured film excellent in dispersibility and storage stability and excellent in moist heat resistance and cold-heat cycle resistance; and a near-infrared-absorbing cured film and optical member in both of which said composition is used.　A near-infrared-absorbing composition according to the present invention contains components (A) through (D) and a dispersion medium. Component (A): A copper complex in which a compound having a structure represented by general formula (I) is coordinated. Component (B): A compound having a structure represented by general formula (II). Component (C): A compound having a structure represented by general formula (III) or (IV). Component (D): A silicone oligomer

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. In particular, the present invention relates to a near-infrared absorbing composition that can form a cured film that has excellent dispersibility and storage stability, and is excellent in resistance to moist heat and thermal cycles. Furthermore, the present invention relates to a near-infrared absorbing cured film and an optical component that use the near-infrared absorbing composition of the present invention.

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

[0003] Such near-infrared cut filters are broadly divided into absorption type and reflection type. Conventionally, reflection type near-infrared cut filters have been used, which utilize light reflection by a dielectric multilayer film to block infrared or ultraviolet rays.

[0004] However, the reflective layer used in reflective types is susceptible to dependence on the angle of incidence. For this reason, total absorption types have been mainly considered in recent years. In recent years, optical filters using films containing light-absorbing agents have been attracting attention.

[0005] Optical filters using a film containing a light absorber are also advantageous in terms of miniaturizing and thinning imaging devices. When light is incident on the optical filter, the transmittance characteristics of the optical filter are less affected by the angle of incidence. Therefore, by using the optical filter, good images with little change in color can be obtained during shooting, even when light is incident at an oblique angle.

[0006] In recent years, near-infrared absorbing compositions using copper phosphonate complexes have been disclosed as materials for producing such near-infrared cut filters.

[0007] For example, Patent Document 1 discloses a near-infrared absorbing composition containing a near-infrared absorbent and a Ti compound. The near-infrared absorbent contains a phosphate ester compound, a phosphonic acid compound, and copper ions.

[0008] Patent Document 2 discloses an infrared absorbing composition containing a light absorber and an alkoxysilane monomer. The light absorber is formed from a phosphonic acid having a phenyl group or a halogenated phenyl group and copper ions.

[0009] International Publication No. 2019-221061 International Publication No. 2018-173386

[0010] As described above, Patent Documents 1 and 2 disclose near-infrared absorbing compositions using copper phosphonate complexes. However, the composition described in Patent Document 1 leaves room for improvement in terms of storage stability, moist heat resistance, and thermal cycle resistance of the cured film. Furthermore, the composition described in Patent Document 2 has problems in terms of storage stability, moist heat resistance, and thermal cycle resistance of the cured film.

[0011] The present invention has been made in view of the above circumstances. An object of the present invention is to provide a near-infrared absorbing composition that can form a cured film that is excellent in dispersibility and storage stability, and that is excellent in moist heat resistance and thermal cycle resistance. Another object of the present invention is to provide a near-infrared absorbing cured film and an optical component that use the near-infrared absorbing composition.

[0012] In order to solve the above problems, the present inventors have investigated the above points to be improved, the problems, and their causes, etc. As a result, the present inventors have found that the above problems can be solved by a composition containing a specific copper phosphonate complex, a specific phosphate ester, a specific Ti compound, a silicone oligomer, and a dispersion medium.

[0013] That is, the above-mentioned problems of the present invention are solved by the following means.

[0014] 1. A near-infrared absorbing composition comprising the following components (A) to (D) and a dispersion medium:

[0015] Component (A): A copper complex coordinated with a compound having a structure represented by the following general formula (I):

[0016] [In general formula (I), R １ is an alkyl group having 1 to 20 carbon atoms, which may further have a substituent.

[0017] Component (B): A compound having a structure represented by the following general formula (II):

[0018] [In general formula (II), R ２ R is an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and may further have a substituent. ２１ ~R ２４ each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ２１ ~R ２４ represents the average number of partial structural units added, each of which is a hydrogen atom, and is in the range of 0 to 19. ２１ ~R ２４ represents the average number of partial structural units added, at least one of which is an alkyl group having 1 to 4 carbon atoms, and is within the range of 0 to 19. m+n represents the total number of m and n, and is within the range of 1 to 20. Z represents a structural unit selected from the following formulae (Z-1) and (Z-2).

[0019]

[0020] 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 is an integer of 1 to 4. R ４is an alkylene group having 1 to 30 carbon atoms, which may further have a substituent. ３ and R ５ are each independently an alkyl group having 1 to 30 carbon atoms, and may further have a substituent.

[0021] Component (D): Silicone oligomer

[0022] 2. The near-infrared absorbing composition according to item 1, wherein m and n in general formula (II) are each within a range of 1 to 19, and m+n is within a range of 2 to 20.

[0023] 3. The near-infrared absorbing composition according to item 1, 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).

[0024] 4. The near-infrared absorbing composition according to item 1, wherein the content of the component (D) is within a range of 10 to 70 parts by mass per 100 parts by mass of the component (A).

[0025] 5. The near-infrared absorbing composition according to item 1, wherein the water content is 0.01% by mass or less.

[0026] 6. A near-infrared absorbing cured film comprising a cured product of the near-infrared absorbing composition according to any one of items 1 to 5.

[0027] 7. An optical member comprising a cured product of the near-infrared absorbing composition according to any one of items 1 to 5.

[0028] The near-infrared absorbing composition of the present invention contains the above components (A) to (D) and a dispersion medium. Therefore, the near-infrared absorbing composition of the present invention can form a cured film that is excellent in dispersibility and storage stability, and is also excellent in moist heat resistance and cold-heat cycle resistance. Furthermore, the near-infrared absorbing cured film of the present invention is a film containing such a cured product of the near-infrared absorbing composition of the present invention, and therefore is excellent in moist heat resistance and cold-heat cycle resistance. Furthermore, the optical member of the present invention contains such a cured product of the near-infrared absorbing composition of the present invention, and therefore is excellent in moist heat resistance and cold-heat cycle resistance.

[0029] 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."

[0030] In a composition containing a copper phosphonate complex as a near-infrared absorbent, a phosphate ester compound functions effectively as a dispersant for the copper phosphonate complex. When a Ti compound is added to the composition, the addition of the Ti compound has the effect of suppressing deterioration of dispersibility due to the inclusion of trace amounts of moisture in the composition. However, the addition of the Ti compound deteriorates the storage stability of the near-infrared absorbing composition over time. This is presumably due to the crosslinking action of the Ti compound.

[0031] The near-infrared absorbing composition of the present invention further contains a silicone oligomer. This allows the synergistic effect of the phosphate ester compound and the silicone oligomer to suppress aggregation of Cu complex particles. Furthermore, the silicone oligomer suppresses the crosslinking action of the Ti compound, thereby improving the dispersibility and storage stability of the near-infrared absorbing composition. Furthermore, when a cured film is formed, the crosslinking action of the Ti compound, which had been suppressed, is expressed by removing the dispersion medium. At the same time, the synergistic effect of the crosslinking action of the silicone oligomer improves the moist heat resistance of the cured film. Furthermore, the crosslinking action, which is effectively achieved by the molecular weight of the silicone oligomer and does not result in excessive hardness, imparts flexibility and pliability to the cured film. This is presumably responsible for the improved thermal cycle resistance.

[0032] 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;

[0033] One embodiment of the near-infrared absorbing composition of the present invention is characterized by containing the above-mentioned components (A) to (D) and a dispersion medium. This feature is a technical feature common to or corresponding to the following embodiments.

[0034] In the near infrared absorbing composition of the present embodiment, it is preferable that m and n in the general formula (II) are each within a range of 1 to 19, and m+n is within a range of 2 to 20. This improves the function of the near infrared absorbing composition of the present embodiment as a dispersant for the component (B), and provides better dispersibility for the component (A).

[0035] In the near-infrared absorbing composition of the present embodiment, 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). This provides a good balance between the storage stability of the near-infrared absorbing composition of the present embodiment and the moist heat resistance of the near-infrared absorbing cured film. The near-infrared absorbing cured film is a cured film containing a cured product of the near-infrared absorbing composition of the present embodiment.

[0036] In the near-infrared absorbing composition of the present embodiment, the content of the component (D) is preferably within a range of 10 to 70 parts by mass per 100 parts by mass of the component (A). This provides a good balance between the storage stability of the near-infrared absorbing composition of the present embodiment and the moist heat resistance of the near-infrared absorbing cured film. The near-infrared absorbing cured film is a cured film containing a cured product of the near-infrared absorbing composition of the present embodiment.

[0037] The near-infrared absorbing composition of the present embodiment preferably has a water content of 0.01% by mass or less. This makes the near-infrared absorbing composition of the present embodiment excellent in storage stability, and the near-infrared absorbing cured film excellent in moist heat resistance. The near-infrared absorbing cured film is a cured film containing a cured product of the near-infrared absorbing composition of the present embodiment.

[0038] One embodiment of the near-infrared absorbing cured film of the present invention is a cured film containing a cured product of the near-infrared absorbing composition of this embodiment. As a result, the near-infrared absorbing cured film of this embodiment has excellent resistance to moist heat and cold cycles.

[0039] One embodiment of the optical member of the present invention is a member containing a cured product of the near-infrared absorbing composition of this embodiment, which has excellent resistance to moist heat and cold cycles.

[0040] The present invention, its components, and modes and aspects for carrying out the present invention will be described in detail below. In this specification, "to" is sometimes used to mean that the numerical values ​​before and after it are included as lower and upper limits. "to" is also sometimes used to mean the alphabets before and after it and the alphabets between them.

[0041] [Near-infrared absorbing composition] The near-infrared absorbing composition of the present embodiment is characterized by containing the following components (A) to (D) and a dispersion medium.

[0042] [Component (A)] The component (A) is a copper complex coordinated with a compound having a structure represented by the following general formula (I). The compound having a structure represented by the following general formula (I) is a phosphonic acid compound. That is, the component (A) is a phosphonic acid copper complex. The component (A) is a near-infrared absorber.

[0043] [In general formula (I), R １ is an alkyl group having 1 to 20 carbon atoms, which may further have a substituent.

[0044] R １ The alkyl group having 1 to 20 carbon atoms represented by the formula (I) may be linear or branched. 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.

[0045] R １Examples of the substituents that may be possessed by include an alkyl group, an alkoxy group, a halogen atom, a cyano group, a nitro group, a dialkylamino group, and a trialkylsilyl group. Examples of the alkyl group include a methyl group, an ethyl group, a trifluoromethyl group, and an isopropyl group. Examples of the alkoxy group include a methoxy group and an ethoxy group. Examples of the halogen atom include a fluorine atom. Examples of the dialkylamino group include a dimethylamino group. Examples of the trialkylsilyl group include a trimethylsilyl group.

[0046] 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.

[0047] R １ is an alkyl group having 1 to 20 carbon atoms, examples of which include methylphosphonic acid, ethylphosphonic acid, propylphosphonic acid, butylphosphonic acid, pentylphosphonic acid, hexylphosphonic acid, heptylphosphonic acid, octylphosphonic acid, nonylphosphonic acid, and decylphosphonic acid.

[0048] As the compound having the structure represented by general formula (I) in component (A), propylphosphonic acid or butylphosphonic acid is particularly preferred.

[0049] The near-infrared absorbing composition may contain, as the component (A), a plurality of copper complexes in which phosphonic acids with different alkyl groups are coordinated.

[0050] As the compound having the structure represented by general formula (I), commercially available products can be used.

[0051] Copper ions (Cu ２＋ The copper complex in which a compound having a structure represented by general formula (I) is coordinated to a copper complex having at least one compound having a structure represented by general formula (I) is sufficient as long as at least one compound having a structure represented by general formula (I) is coordinated. The copper complex may also be one in which both a compound having a structure represented by general formula (I) and another compound are coordinated.

[0052] The structure of the copper complex coordinated with the compound having the structure represented by general formula (I) is represented, for example, by the following general formula (IC).

[0053]

[0054] R in the following general formula (IC) １ represents R in general formula (I). １ is the same as

[0055] Among the hydroxy groups possessed by phosphonic acid, the hydroxy group directly bonded to the phosphorus atom is called a "reactive hydroxy group." In general formula (IC), two reactive hydroxy groups of one phosphonic acid react with the same copper ion to form a copper complex. However, the form of the phosphonic acid copper complex is not limited to this.

[0056] The near-infrared absorbing composition may contain one or more types of component (A).

[0057] Phosphonic acid can be synthesized by referring to known methods described in, for example, JP-A-2016-94512 and JP-A-2016-124903.

[0058] In the near-infrared absorbing composition, the phosphonic acid copper complex as component (A) is preferably mainly in the form of fine particles. Hereinafter, the fine particle-shaped phosphonic acid copper complex as component (A) may also be referred to as "copper complex fine particles."

[0059] The content of component (A) in the near-infrared absorbing composition is preferably in the range of 3 to 40% by mass, more preferably in 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, particle aggregation and an increase in viscosity of the composition can be suppressed, and the storage stability of the composition is improved. When the content is 30% by mass or less, the storage stability of the composition is further improved.

[0060] From the viewpoint of spectral characteristics, it is preferable that the copper complex fine particles are uniformly dispersed when a cured film is formed. To this end, it is preferable that the particle size of the copper complex fine particles in the near-infrared absorbing composition (dispersion) is small. The average particle size of the copper complex fine particles in the near-infrared absorbing composition is preferably 200 nm or less, more preferably 100 nm or less, and more preferably 80 nm or less. An example of an apparatus for measuring the average particle size of copper complex fine particles is the ELSZ-1000ZS manufactured by Otsuka Electronics Co., Ltd. The average particle size of the copper complex fine particles can be measured by a dynamic light scattering method using this measuring apparatus.

[0061] [Component (B)] Component (B) is a phosphate ester compound having a structure represented by the following general formula (II). Component (B) exerts the effect of forming nano-sized small particle diameters when a phosphonate copper complex is formed. Component (B) also contributes to maintaining the dispersibility of the phosphonate copper complex particles in a medium.

[0062] [In general formula (II), R ２ is an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and may further have a substituent. ２１ ~R ２４ each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ２１ ~R ２４ represents the average number of partial structural units added, each of which is a hydrogen atom, and is in the range of 0 to 19. ２１ ~R ２４ represents the average number of partial structural units added, at least one of which is an alkyl group having 1 to 4 carbon atoms, and is within the range of 0 to 19. m+n represents the total number of m and n, and is within the range of 1 to 20. Z represents a structural unit selected from the following formulae (Z-1) and (Z-2).

[0063]

[0064] R ２１ ~R ２４ When all of are hydrogen atoms, the partial structure in the parentheses in the formula is called an "ethylene oxide structure." In the formula, m is the average number of ethylene oxide structures added.

[0065] R ２１ ~R ２４ The partial structure in the parentheses in the formula, in which at least one of the above is an alkyl group having 1 to 4 carbon atoms and the others are hydrogen atoms, is called an "alkyl-substituted ethylene oxide structure." n in the formula is the average number of alkyl-substituted ethylene oxide structures added.

[0066] In the compound having the structure represented by general formula (II), either m or n is equal to or greater than 1. This gives the compound a high ability to form a complex with copper, and a high effect as a dispersant.

[0067] In general formula (II), m and n each preferably fall within the range of 1 to 19, and m+n preferably falls within the range of 2 to 20. This indicates that the compound having the structure represented by general formula (II) simultaneously has at least one partial structure that satisfies the following condition (i) and at least one partial structure that satisfies the following condition (ii). This further enhances the effect of component (B) as a dispersant. Condition (i): R ２１ ~R ２４ are all hydrogen atoms. ２１ ~R ２４ At least one of the groups is an alkyl group having 1 to 4 carbon atoms.

[0068] The compound having the structure represented by general formula (II) has a large number of isomers due to the combination of the ethylene oxide structure and the alkyl-substituted ethylene oxide structure. This increases the entropy, and therefore the compound is highly effective as a dispersant. In addition, the compound has a substituent (R ２１ ~R ２４ The effect of steric hindrance of the ethylene oxide structure and the alkyl-substituted ethylene oxide structure is suppressed, and the copper complex can be finely dispersed. Therefore, the effects of the ethylene oxide structure and the alkyl-substituted ethylene oxide structure are exerted in a well-balanced manner. Therefore, the compound can improve the dispersibility and dispersion stability of the near-infrared absorbing composition.

[0069] In general formula (II), R ２１ ~R ２４It is more preferable that at least one of the groups is a methyl group from the viewpoint of dispersibility of the copper complex.

[0070] In general formula (II), R ２ is preferably an alkyl group having 6 to 16 carbon atoms from the viewpoint of dispersibility of the copper complex and resistance to humidity and heat.

[0071] In formula (Z-1) and formula (Z-2) of general formula (II), "*" indicates the bonding site where Z bonds to the oxygen atom "O". A compound having a structure represented by general formula (II) becomes a diester when Z is formula (Z-1), and becomes a monoester when Z is formula (Z-2). A compound of general formula (II) becomes a structure in which two "groups obtained by removing Z from the structure represented by general formula (II)" bond to formula (Z-1) when Z is formula (Z-1).

[0072] The mixing ratio of the diester and the monoester is preferably such that the molar ratio of the monoester to the total amount of the diester and the monoester is within the range of 20 to 95%.

[0073] Specific examples of compounds having a structure represented by general formula (II) are shown in Tables I to V below. The compounds having a structure represented by general formula (II) related to the near-infrared absorbing composition of the present embodiment are not limited to these. In this specification, compounds shown as specific examples of the general formula may be referred to as "exemplary compounds."

[0074] In Tables I to V, which list exemplary compounds (Nos. II-1 to II-91), both (Z-1) and (Z-2) are listed in the "Structure" column for "Z." These exemplary compounds are mixtures of "compounds in which Z is formula (Z-1)" and "compounds in which Z is formula (Z-2)."

[0075]

[0076]

[0077]

[0078]

[0079]

[0080] A specific description will be given of Exemplary Compound II-1 (No. II-1) in Table I. Exemplary Compound 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).

[0081] A compound (monoester) in which Z is formula (Z-2) is represented, for example, by the structure of the following exemplary compound II-1-1. A compound (diester) in which Z is formula (Z-1) is represented, for example, by the structure of the following exemplary compound II-1-2.

[0082]

[0083] In Exemplary Compound II-1, the molar ratio of the compound (monoester) in which Z is represented by Formula (Z-2) is 50%. That is, Exemplary Compound II-1 contains Exemplary Compound II-1-1 and Exemplary Compound II-1-2 in equimolar amounts.

[0084] m and n are the average addition numbers. Therefore, even in the case of Exemplified Compound II-1, in which both m and n are 5, one molecule does not necessarily contain five EO structures and five alkyl-substituted EO structures. The "EO structure" means an ethylene oxide structure.

[0085] In general formula (II), the order of the ethylene oxide structure and the alkyl-substituted ethylene oxide structure is not particularly limited. Compounds in which each structure is randomly arranged are also included in the compounds having the structure represented by general formula (II). The order of the ethylene oxide structure and the alkyl-substituted ethylene oxide structure can be arbitrarily changed depending on the synthesis method.

[0086] 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

[0087] The near-infrared absorbing composition may contain one or more types of component (B).

[0088] 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, per 100 parts by mass of the component (A), which allows for a better balance between the storage stability of the near-infrared absorbing composition and the moist heat resistance of the cured film.

[0089] 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, it has been found that the phosphate ester compound (component (B)) causes cloudiness in high-temperature, high-humidity environments. Therefore, by reducing the proportion of component (B), the moist heat resistance of the cured film improves. However, a certain amount of the phosphate ester compound is necessary to maintain the dispersibility of the copper complex microparticles.

[0090] [Component (C)] Component (C) is a compound having a structure represented by the following general formula (III) or (IV), and is a Ti compound.

[0091] 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

[0092] [In general formula (III) and general formula (IV), m is an integer of 1 to 4. R ４ is an alkylene group having 1 to 30 carbon atoms, which may further have a substituent. ３ and R ５ are each independently an alkyl group having 1 to 30 carbon atoms, and may further have a substituent.

[0093] R ３ and R ５ The alkyl group having 1 to 30 carbon atoms represented by the formula (I) may be linear or branched.

[0094] Examples of alkyl groups having 1 to 30 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-hexyl, 2-ethylhexyl, n-octyl, 2-butyloctyl, 2-hexyloctyl, n-decyl, n-dodecyl, 2-hexyldecyl, n-stearyl, and isostearyl. ３ and R ５ Among the alkyl groups having 1 to 30 carbon atoms represented by the formula (I), alkyl groups having 6 to 20 carbon atoms are preferred.

[0095] R ４ The alkylene group having 1 to 30 carbon atoms represented by the formula (I) may be linear or branched.

[0096] Examples of alkylene groups having 1 to 30 carbon atoms include methylene, ethylene, n-propylene, isopropylene, n-butylene, tert-butylene, n-hexylene, 2-ethylhexylene, n-octylene, 2-butyloctylene, 2-hexyloctylene, n-decylene, n-dodecylene, 2-hexyldecylene, n-stearylene, and isostearylene. ４ Among the alkylene groups having 1 to 30 carbon atoms represented by the formula (I), alkylene groups having 6 to 20 carbon atoms are preferred.

[0097] R ３ , R ４ and R ５ Examples of the substituents that each of may have include an alkyl group, an alkoxy group, a halogen atom, a cyano group, a nitro group, a dialkylamino group, and a trialkylsilyl group. Examples of the alkyl group include a methyl group, an ethyl group, a trifluoromethyl group, and an isopropyl group. Examples of the alkoxy group include a methoxy group and an ethoxy group. Examples of the halogen atom include a fluorine atom. Examples of the dialkylamino group include a dimethylamino group. Examples of the trialkylsilyl group include a trimethylsilyl group.

[0098] 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:

[0099] Examples of the 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 the titanium chelate compounds, titanium octylene dioleate is preferred.

[0100] Specific examples of the compound having the structure represented by general formula (III) are shown below: The compound having the structure represented by general formula (III) according to the present invention is not limited to these.

[0101]

[0102]

[0103] Compounds having a structure represented by general formula (III) are also available as commercially available products, such as "Orgatix TC245" (manufactured by Matsumoto Fine Chemical Co., Ltd.).

[0104] The compound having the structure represented by general formula (IV) is more preferably a compound that forms an acylate structure, and examples of such compounds include the following titanium acylate compounds:

[0105] Examples of the titanium acylate compound include titanium caprylate, titanium caprate, titanium laurate, titanium myristylates, titanium palmitates, titanium stearate, and titanium isostearate. Of the titanium acylate compounds, titanium isostearate is preferred.

[0106] Specific examples of the compound having the structure represented by general formula (IV) are shown below: The compound having the structure represented by general formula (IV) according to the present invention is not limited to these.

[0107]

[0108] Compounds having a structure represented by general formula (IV) are also available as commercially available products, such as "Orgatix TC-800" (manufactured by Matsumoto Fine Chemical Co., Ltd.).

[0109] 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.

[0110] The near-infrared absorbing composition may contain one or more types of component (C).

[0111] The content of the component (C) is preferably in the range of 1 to 30 parts by mass, more preferably in the range of 3 to 20 parts by mass, per 100 parts by mass of the component (A). This results in a good balance between the dispersibility and storage stability of the near-infrared absorbing composition and the moist heat resistance of the near-infrared absorbing cured film. When the content of the component (C) is a certain amount or more, the dispersibility of the near-infrared absorbing composition and the moist heat resistance of the cured film tend to be good. When the content of the component (C) is a certain amount or less, the storage stability of the near-infrared absorbing composition tends to be good.

[0112] [Component (D)] The silicone oligomer of component (D) is not particularly limited as long as it is an oligomer of a silane compound having an alkoxy group. Examples of the silicone oligomer of component (D) include silicone oligomers represented by general formula (V):

[0113] General formula (V) [-Si(OR ６ ) (R ７ )-O-]m

[0114] [In the formula, R ６ represents an alkyl group. ７ represents an alkyl group or an aryl group. m represents the number of repeating monomer units and represents an integer of 2 to 100. ６ , and m R ７ may be the same or different.

[0115] In general formula (V), the silicon atom terminal usually has a group "-OR６ " is bonded to the oxygen atom side end, and the group "R ７ " is bonded to the silicon atom. The group is also sometimes called an alkoxysilyl group, including a silicon atom bonded to an alkoxy group.

[0116] In the above general formula (V), R ６ and R ７ Examples of the alkyl group represented by the formula (I) include the following. That is, the alkyl group includes a linear or branched alkyl group having 1 to 6 carbon atoms. Specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, etc. The alkyl group is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, more preferably a linear alkyl group having 1 to 4 carbon atoms, and even more preferably a methyl group. R ７ Examples of the aryl group represented by the formula (I) include aryl groups having 6 to 10 carbon atoms, such as a phenyl group, a 1-naphthyl group, a 2-naphthyl group, and a p-tolyl group. Of these, a phenyl group is preferred as the aryl group. ７ The substituent represented by the formula (I) is particularly preferably a group having a methyl group or a phenyl group.

[0117] The weight average molecular weight of the silicone oligomer of component (D) is preferably 300 to 10,000, and more preferably 400 to 8,000.

[0118] The silicone oligomer of component (D) is also available as a commercially available product, examples of which include KR-213, KR-401N, KR-500, KR-510, KR-515, KR-9218, KC-89S, X-40-9225, X-40-9227, X-40-9246, and X-40-9250 (all manufactured by Shin-Etsu Chemical Co., Ltd.).

[0119] The near-infrared absorbing composition may contain one or more types of component (D).

[0120] The content of component (D) is preferably within a range of 10 to 70 parts by mass, and more preferably within a range of 30 to 50 parts by mass, per 100 parts by mass of component (A). This provides a good balance between the storage stability of the near-infrared absorbing composition and the moist heat resistance of the near-infrared absorbing cured film. Furthermore, by imparting flexibility and pliability to the cured film, resistance to thermal cycling can be improved.

[0121] [Water Content] It has been confirmed that the dispersibility of the component (A) in the near-infrared absorbing composition of the present embodiment deteriorates when water is present. Therefore, the water content of the near-infrared absorbing composition is preferably 0.01% by mass or less. It is more preferable that the near-infrared absorbing composition contains substantially no water. This improves the storage stability of the near-infrared absorbing composition and the moist heat resistance of the near-infrared absorbing cured film.

[0122] The water content can be measured using a Karl Fischer moisture meter, such as KF-06 (manufactured by Mitsubishi Chemical Corporation).

[0123] [Dispersion medium] The dispersion medium that can be used in the near-infrared absorbing composition of the present embodiment is not particularly limited. Examples of the dispersion medium include an ether-based compound (dispersion medium) and a hydrocarbon-based compound (dispersion medium).

[0124] The dispersion medium preferably has a polarity term δ of the Hansen solubility parameter Ｐ The value of is in the range of 2 to 6, and the hydrogen bond term δ Ｈ The value of is in the range of 2 to 6.

[0125] 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 , polarity term δ Ｐ , hydrogen bond term δ Ｈ It is divided into three components and represented in three-dimensional space.

[0126] Dispersion term δ Ｄ represents the energy derived from dispersion forces. Ｐrepresents the energy derived from polar forces. The hydrogen bond term δ Ｈ represents the energy derived from hydrogen bonding forces.

[0127] In the present invention, δ Ｄ , δ Ｐ and δ Ｈ The unit is MPa １／２ is.

[0128] 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).

[0129] Compounds with similar HSP vectors can be judged to have high solubility. The similarity of the vectors can be determined by the HSP distance.

[0130] HSP can be an indicator not only of solubility but also of the degree to which a substance is likely to exist in another substance, i.e., dispersibility.

[0131] The HSP of each dispersion medium used in the near-infrared absorbing composition of the present embodiment is a value determined using the following commercially available computer software: "Hansen Solubility Parameters in Practice (HSPiP)"

[0132] The dispersion medium is not particularly limited other than the above requirements for HSP, but is preferably an ether-based dispersion medium.

[0133] From the viewpoint of dispersibility, the dispersion medium preferably has a cycloalkyl group or a cycloether group.

[0134] From the viewpoint of dispersibility, the cycloalkyl group is preferably a cyclopentyl group or a cyclohexyl group, and the cycloether group is preferably a tetrahydrofuran group or a tetrahydropyran group.

[0135] The term "dispersibility" refers to the performance or function as a dispersion medium that disperses components constituting the near-infrared absorbing composition in an appropriate state in the near-infrared absorbing composition.

[0136] The term "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 due to the passage of time, changes in environmental conditions, etc.

[0137] The dispersion medium is more preferably cyclopentyl methyl ether or 4-methyltetrahydropyran, and particularly preferably cyclopentyl methyl ether. These can disperse the near-infrared absorbing composition in an appropriate state. This further improves the storage stability of the near-infrared absorbing composition.

[0138] Specific examples of the dispersion medium are shown in Table VI, but the dispersion medium according to the present invention is not limited to these.

[0139]

[0140] The boiling point of the dispersion medium is preferably within the range of 80 to 150° C. from the viewpoint of preventing cracks during the formation of the cured film.

[0141] The near-infrared absorbing composition may contain one or more types of dispersion medium.

[0142] The content of the dispersion medium is more preferably within a range of 50 to 95% by mass based on the total amount of the near-infrared absorbing composition, from the viewpoints of dispersibility and storage stability.

[0143] [Near-infrared absorbing cured film] One embodiment of 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 embodiment.

[0144] The near-infrared absorbing cured film of this embodiment is suitable for constituting the following, for example, for CCDs, CMOSs, or other light-receiving elements: That is, the near-infrared absorbing cured film of this embodiment is suitable for constituting visibility correction members, photometric members, heat ray 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 ray-cutting members, color tone correction members, illumination brightness adjustment members, optical elements (light amplifiers, wavelength conversion elements, etc.), Faraday elements, optical communication functional devices such as isolators, and optical disc elements.

[0145] The near-infrared absorbing cured film of this embodiment can be produced, for example, by the following procedure. First, a resin material is dissolved in the near-infrared absorbing composition (dispersion) of this embodiment to prepare a coating liquid for forming the near-infrared absorbing cured film. The coating liquid is applied to a substrate by a wet coating method. The coating film is cured by performing a predetermined heat treatment or the like. This results in a near-infrared absorbing cured film of this embodiment containing a cured product of the near-infrared absorbing composition of this embodiment. The near-infrared absorbing cured film of this embodiment may further contain a cured product of a resin material as described above.

[0146] 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.

[0147] The thickness of the near-infrared absorbing cured film is preferably in the range of 10 to 500 μm, more preferably in the range of 10 to 300 μm.

[0148] 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.

[0149] 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 near-infrared absorbing 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, a resin material having a polysiloxane structure is particularly preferred because it is resistant to thermal decomposition, has high optical transparency for visible light and near-infrared light, and is also highly heat-resistant.

[0150] 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.).

[0151] Examples of resin materials having epoxy groups include KJC-X5 (manufactured by Shin-Etsu Chemical Co., Ltd.) and EpiFine series (manufactured by KISCO Corporation).

[0152] The resin material having an acrylic group is preferably a (meth)acrylic acid ester monomer, examples of which include alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, and n-butyl (meth)acrylate, modified (meth)acrylates such as phenoxy (meth)acrylate, and polyfunctional (meth)acrylates such as trimethylolpropane tri(meth)acrylate and pentaerythritol tetra(meth)acrylate.

[0153] A polymer (resin polymer) may be used as the resin material for forming the near-infrared absorbing film. Examples of the polymer (resin polymer) include polymers of (meth)acrylic acid ester compounds, polymers of aromatic vinyl compounds such as styrene, α-methylstyrene, methoxystyrene, and divinylbenzene, and cycloolefin polymers (COP).

[0154] In this specification, the term "(meth)acrylic group" means both a "methacrylic group" and an "acrylic group."

[0155] The coating liquid for forming a near-infrared absorbing 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, and plasticizers. 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, and surface treatment agents. By appropriately adding these components to the coating liquid, the stability, film properties, and other properties of the near-infrared absorbing cured film can be adjusted.

[0156] [Spectral Properties of Near-Infrared Absorbing Composition (Dispersion)] The near-infrared absorbing composition preferably has an average spectral transmittance of 70% or more in a wavelength region of 450 to 600 nm, more preferably 80% or more, and even more preferably 90% or more. This is the value measured after diluting the near-infrared absorbing composition with a dispersion medium so that the maximum spectral transmittance in a wavelength region of 850 to 1000 nm is 10%. This results in a good visible light transmittance of the cured film.

[0157] As a device for measuring the spectral transmittance, for example, a spectrophotometer V-570 manufactured by JASCO Corporation can be used.

[0158] [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 has an average spectral transmittance of 80% or more in the wavelength region of 450 to 600 nm.

[0159] From the viewpoint of near-infrared absorbing properties, it is preferable that the average spectral transmittance of the near-infrared absorbing cured film in the wavelength region of 850 to 1000 nm is 10% or less.

[0160] From the viewpoint of near-infrared absorbing properties, it is preferable that the near-infrared absorbing cured film has an average spectral transmittance of 1% or less in the wavelength region of 850 to 1080 nm.

[0161] The cutoff wavelength is the wavelength at which the spectral transmittance decreases with increasing wavelength from 600 to 700 nm, and the wavelength at which the spectral transmittance is 50% from 600 to 800 nm. 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 improves the near-infrared absorbing properties of the cured film.

[0162] [Optical Member] One embodiment of the optical member of the present invention is characterized by containing a cured product of the near-infrared absorbing composition of the present embodiment.

[0163] The near-infrared absorbing cured film of the present embodiment containing the cured product of the near-infrared absorbing composition of the present embodiment can be used as various optical members or parts. The optical members or parts are the optical member of the present embodiment or parts equipped with the optical member of the present embodiment.

[0164] Hereinafter, examples of application of the near-infrared absorbing composition or the near-infrared absorbing cured film as an optical member or part will be described.

[0165] (Near-infrared cut filter) The optical member of this embodiment is, for example, a near-infrared cut filter. The near-infrared cut filter includes, for example, a near-infrared absorbing layer on at least one surface of a transparent dielectric substrate. The near-infrared absorbing layer is a cured product of the near-infrared absorbing composition of this embodiment.

[0166] It is preferable to further provide a dielectric multilayer film on at least one surface of the transparent dielectric substrate, since this allows more flexible adjustment of the spectral characteristics of the near-infrared cut filter.

[0167] 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 an intermediate layer.

[0168] FIG. 1 is a schematic cross-sectional view showing an example of the configuration of a near-infrared cut filter.

[0169] 1 includes a near-infrared absorbing layer 22 on one surface of a transparent dielectric substrate 21. The near-infrared absorbing filter 9 further includes a dielectric multilayer film 23 on the other surface of the transparent dielectric substrate 21.

[0170] The material of the transparent dielectric substrate is not particularly limited as long as the object of the present invention is achieved. The transparent dielectric substrate may be made of, for example, glass or optical resin. Examples of optical resin include polycarbonate (PC), polymethyl methacrylate (PMMA), cycloolefin polymer (COP), and silicone.

[0171] The thickness of the transparent dielectric substrate is preferably 0.01 to 1 mm.

[0172] 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.

[0173] The near-infrared absorbing cured film of this embodiment can be used for the near-infrared absorbing layer 22 .

[0174] A near-infrared cut filter can be produced by forming a near-infrared absorbing cured film directly on a transparent dielectric substrate as a near-infrared absorbing layer.

[0175] A dielectric multilayer film is a film formed by stacking multiple layers made of materials with different refractive indices. The dielectric multilayer film is used to control the transmittance of each wavelength of light. By incorporating a dielectric multilayer film and a near-infrared absorbing layer together, the spectral characteristics of a near-infrared cut filter can be adjusted more freely.

[0176] The spectral characteristics of the dielectric multilayer film can be adjusted by the thickness and material of each layer. For example, the following dielectrics can be used as the material for each layer of the dielectric multilayer film. The dielectrics that can be used for the materials for each layer include 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.

[0177] 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.

[0178] 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.

[0179] (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. The 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.

[0180] The image sensor for a solid-state imaging device may include a planarizing layer, a glass substrate, and the like in addition to the near-infrared cut filter.

[0181] FIG. 2 is a schematic cross-sectional view showing an example of the configuration of an image sensor for a solid-state imaging device.

[0182] The solid-state imaging element image sensor 14 shown in Figure 2 includes a solid-state imaging element substrate 10, a planarization layer 8, a near-infrared cut filter 9, and a glass substrate 3. Each component is bonded with an adhesive 2. The solid-state imaging element substrate 10 includes a light-receiving element on the light-receiving surface of a silicon substrate. The planarization layer 8 is provided on the solid-state imaging element substrate 10. The near-infrared cut filter 9 is provided on the planarization layer 8. The glass substrate 3 is disposed above the near-infrared cut filter 9. The glass substrate 3 is a light-transmitting substrate.

[0183] (Camera Module) The image sensor for a solid-state imaging device can be provided in a camera module. The camera module can 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.

[0184] FIG. 3 is a schematic cross-sectional view showing an example of the configuration of a camera module.

[0185] 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 planarizing 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.

[0186] 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.

[0187] 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.

[0188] The present invention will be specifically described below with reference to examples. The present invention is not limited to these examples. In the following examples, unless otherwise specified, operations were performed at room temperature (25°C). In the following examples, unless otherwise specified, "%" and "parts" mean "% by mass" and "parts by mass", respectively.

[0189] <Preparation of Near-Infrared Absorbing Composition> Near-infrared absorbing composition No. 1 was prepared according to the following method.

[0190] The following compounds and solvents were mixed in the amounts shown below, stirred for 3 hours, and filtered to remove insoluble matter, to prepare solution A: Copper (II) acetate monohydrate 18 g Tetrahydrofuran 800 g

[0191] The following compounds were dissolved in the following solvents in the following amounts to prepare solutions. Exemplary compound II-66 is a compound (component (B)) having a structure represented by general formula (II). Solution A was added to this, and the mixture was stirred at room temperature for 30 minutes to prepare solution B.

[0192] Exemplary compound II-66 10 g Tetrahydrofuran 70 g

[0193] The following compounds were dissolved in the following solvents in the following amounts to prepare a solution C. Butylphosphonic acid is a compound having a structure represented by general formula (I): Butylphosphonic acid 12 g Tetrahydrofuran 70 g

[0194] Solution C was added to solution B while stirring, and the mixture was stirred at room temperature for 16 hours. The resulting solution was designated solution D.

[0195] The entire amount of Solution D and 300 g of methylcyclohexane were placed in a flask. This was heated to 50-100°C and subjected to solvent and acetic acid removal treatments using a rotary evaporator. Then, 300 g of cyclopentyl methyl ether was added to this. The solvent removal operation using the rotary evaporator was repeated three times. In this way, the solvent was replaced with cyclopentyl methyl ether (dispersion medium), and the concentration of component (A) was adjusted to 10 mass%. Component (A) is a copper complex in which a compound (butylsulfonic acid) having a structure represented by general formula (I) is coordinated to copper ions as a ligand. The solution obtained is designated Solution E.

[0196] The following compound and silicone oligomer (component (D)) were dissolved in the following amounts in the following dispersion medium. Exemplary compound IV-1 is a compound having a structure represented by general formula (IV) (component (C)). This was added to 100 g of solution E and stirred at room temperature for 30 minutes to obtain near-infrared absorbing composition No. 1. In near-infrared absorbing composition No. 1, cyclopentyl methyl ether is a dispersion medium in which the copper complex, which is component (A), is dispersed. Exemplary compound IV-1 1.0 g Silicone oligomer KR213 (trade name) (manufactured by Shin-Etsu Chemical Co., Ltd.) 4.0 g Cyclopentyl methyl ether 10 g

[0197] Near infrared absorbing compositions Nos. 2 to 40 were prepared in the same manner as near infrared absorbing composition No. 1, except that the following components and dispersion medium types were changed as shown in Tables VII and VIII. The compound type refers to the type of compound, and the silicone oligomer type and dispersion medium type also refer to their respective types. Component (A): Compound type having a structure represented by general formula (I) Component (B): Compound type having a structure represented by general formula (II) Component (C): Compound type and amount added having a structure represented by general formula (III) or (IV) Component (D): Silicone oligomer type and amount added Dispersion medium type

[0198] In the column for the chemical species of component (D), "KR510" means silicone oligomer KR510 (product name) (manufactured by Shin-Etsu Chemical Co., Ltd.), and "TEOS" means tetraethoxysilane (manufactured by Tokyo Chemical Industry Co., Ltd.).

[0199] The resulting near-infrared absorbing compositions were evaluated for dispersibility and storage stability (changes in particle size and viscosity) and their water contents (moisture contents) were measured by the following methods. The results are shown in Tables VII and VIII.

[0200]

[0201]

[0202] <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 immediately after preparation was diluted with toluene so that the solid content concentration was 0.5% by mass, and the average particle size was measured. The average particle size was measured using a particle size measuring device (ELSZ-1000ZS manufactured by Otsuka Electronics Co., Ltd.) using a dynamic light scattering method. Evaluation was performed according to the following evaluation criteria, which was used as a measure of dispersibility. Evaluation criteria A indicates the highest dispersibility, followed by B, C, and D, in that order. A and B indicate excellent dispersibility, and C and D indicate poor dispersibility.

[0203] 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.

[0204] <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.

[0205] (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 using the same method as described above. The average particle size variation rate [%] (the ratio of the variation to the average particle size before standing) was calculated from the average particle sizes before and after standing. The variation rate was the value obtained by subtracting the average particle size before standing from the average particle size after standing. The average particle size variation rate [%] was evaluated according to the following criteria. Evaluation criterion A indicates the highest storage stability, followed by B, C, and D, in that order. A and B indicate excellent storage stability, and C and D indicate poor storage stability.

[0206] 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.

[0207] (Change in Viscosity) The viscosity of the near-infrared absorbing composition was measured immediately after preparation. 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 [%] (ratio of the variation to the viscosity before heating) was calculated from the viscosities before and after heating. The variation rate is the value obtained by subtracting the viscosity before standing from the viscosity after standing. The viscosity variation rate [%] was evaluated according to the following criteria. Evaluation criteria A indicates the highest storage stability, followed by B, C, and D, in that order. A and B indicate excellent storage stability, and C and D indicate poor storage stability. The viscosity was measured using a vibration viscometer (VM-10A manufactured by Sekonic Corporation).

[0208] 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.

[0209] <Evaluation of Water Content> The water content (water content) contained in the near-infrared absorbing composition was measured using a Karl Fischer moisture meter (KF-06 manufactured by Mitsubishi Chemical Corporation). The water content was calculated by the formula "(water content / mass of infrared absorbing composition) × 100".

[0210] The results shown in Tables VII and VIII show that the near-infrared absorbing composition of the present invention is excellent in dispersibility and storage stability.

[0211] <Preparation of near-infrared absorbing cured film> The near-infrared absorbing composition and the following resin material were mixed in the combinations shown in Tables IX and X so that the solid content ratio of the resin material was 70 mass %. In this way, coating solutions for forming near-infrared absorbing cured films No. 1 to 60 were prepared, respectively.

[0212] Details of the resin materials used are as follows.

[0213] (Resin Material No. 1) 80% by mass of 2-ethylhexyl methacrylate, 19% by mass of trimethylolpropane triacrylate, and 1.0% by mass of a polymerization initiator, Perbutyl ND (manufactured by NOF Corporation), were mixed together to obtain Resin Material No. 1.

[0214] (Resin Material No. 2) Silicone resin KR311 (manufactured by Shin-Etsu Chemical Co., Ltd.) was used as resin material No. 2.

[0215] The above-described coating liquids for forming near-infrared absorbing cured films Nos. 1 to 60 were cast-coated onto glass substrates. At this time, the coating amounts were adjusted so as to obtain thicknesses that would result in a maximum spectral transmittance of 10% in a wavelength range of 850 to 1000 nm after curing. The glass substrates coated with the coating liquids were pre-baked on a hot plate at 110°C for 2 minutes.

[0216] The composition was then cured by heating 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.

[0217] In this way, near-infrared absorbing cured films Nos. 1 to 60 were prepared.

[0218] The obtained near-infrared absorbing cured film was evaluated for its resistance to moist heat and thermal cycles by the following methods. The results are shown in Tables IX and X.

[0219]

[0220]

[0221] <Evaluation of moist heat resistance of near-infrared absorbing cured film> The average transmittance T of the near-infrared absorbing cured film in the wavelength region of 400 to 700 nm immediately after preparation 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 transmittance T ａｖｅ２ The average transmittance was measured using a spectrophotometer V-570 manufactured by JASCO Corporation.

[0222] T ａｖｅ１ T for ａｖｅ２ The decrease in visible light transmittance (T ａｖｅ１ -T ａｖｅ２ ) (%) was calculated. The extent of decrease in visible light transmittance was evaluated according to the following criteria, and this was used as a measure of moist heat resistance. Evaluation criteria A indicates the highest moist heat resistance, followed by B, C, and D, in that order. A and B indicate excellent moist heat resistance, and C and D indicate poor moist heat resistance.

[0223] 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.

[0224] <Evaluation of Thermal Cycle Resistance of Near-Infrared Absorbing Cured Film> The thermal cycle resistance of the prepared near-infrared absorbing cured film was evaluated (tested) using a thermal shock device (TSA manufactured by Espec Corporation). The test conditions were -45°C to 85°C, a holding time of 60 minutes, and 250 cycles. The evaluation method involved visually checking the change in appearance of the cured film, and the evaluation criteria were A to D below. Evaluation criteria A indicates the highest thermal cycle resistance, followed by B, C, and D, in that order. A and B indicate excellent thermal cycle resistance, and C and D indicate poor thermal cycle resistance.

[0225] A: No defects in appearance such as foaming or peeling are observed over the entire surface of the cured film. B: Only slight lifting is observed at the corners of the cured film. C: Slight lifting is observed at the edges of the cured film. D: Foaming is observed over the entire surface of the polarizing plate or lifting of 1 mm or more is observed at the edges.

[0226] The results shown in Tables IX and X show that the near-infrared absorbing cured film of the present invention is excellent in resistance to moist heat and cold cycles.

[0227] From the above results, it can be confirmed that the near-infrared absorbing composition of the present invention is excellent in dispersibility and storage stability, and can form a cured film that is excellent in moist heat resistance and thermal cycle resistance.

[0228] According to the present invention, it is possible to provide a near-infrared absorbing composition that is excellent in dispersibility and storage stability, and is capable of forming a cured film that is excellent in resistance to moist heat and thermal cycles.

[0229] 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 components (A) to (D) and a dispersion medium: Component (A): 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): a compound having a structure represented by the following general formula (II). [In general formula (II), R ２ R is an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and may further have a substituent. ２１ ~R ２４ each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ２１ ~R ２４ represents the average number of partial structural units added, each of which is a hydrogen atom, and is in the range of 0 to 19. ２１ ~R ２４ represents the average number of partial structural units added, at least one of which is an alkyl group having 1 to 4 carbon atoms, and is within the range of 0 to 19. m+n represents the total number of m and n, and is within the range of 1 to 20. Z represents a structural unit selected from the following formulae (Z-1) and (Z-2). 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 is an integer of 1 to 4. R ４ is an alkylene group having 1 to 30 carbon atoms, which may further have a substituent. ３ and R ５ are each independently an alkyl group having 1 to 30 carbon atoms, and may further have a substituent.] Component (D): Silicone oligomer 2. The near-infrared absorbing composition according to claim 1, wherein m and n in the general formula (II) are each within the range of 1 to 19, and m+n is within the range of 2 to 20.

3. The near-infrared absorbing composition according to claim 1, 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).

4. The near-infrared absorbing composition according to claim 1, characterized in that the content of the component (D) is within the range of 10 to 70 parts by mass per 100 parts by mass of the component (A).

5. The near-infrared absorbing composition according to claim 1, characterized in that the water content is 0.01% by mass or less.

6. A near-infrared absorbing cured film comprising a cured product of the near-infrared absorbing composition according to any one of claims 1 to 5.

7. An optical component comprising a cured product of the near-infrared absorbing composition according to any one of claims 1 to 5.

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