Curable resin composition for lens, cured product, diffractive optical element, and multilayer diffractive optical element

Abstract

To provide a curable resin composition for a lens enabling acquisition of a cured product which enables wavelength dependence of a refractive index thereof be controlled to a desired level from near-infrared rays to short wavelength-infrared rays, and enables production of a cured product exhibiting high transmittance in the wavelength region, and to provide a cured product, a diffraction optical element, and a multi-layered optical element each obtained using the curable resin composition for a lens.SOLUTION: A curable resin composition for a lens is provided, including a dye A having maximum absorption at a wavelength of 520-620 nm, wherein wavelength dispersion WD calculated by the following expression (X) of the cured product of the composition is 2.0×10-5 or more. A cured product, a diffraction optical element and a multi-layered optical element each obtained by using the curable resin composition for a lens are also provided. Expression (X): WD=(nC-n(1129)) / (1129-656). In the expression, nC represents a refractive index at a wavelength of 656 nm, and n(1129) represents a refractive index at a wavelength of 1,129 nm.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a curable resin composition for lenses. The present invention also relates to a cured product, a diffractive optical element, and a multilayer diffractive optical element obtained by using the above curable resin composition for lenses.

Background Art

[0002] By using a diffractive optical element, a lens can be obtained in which the focal length is shorter for longer wavelengths and the chromatic aberration is opposite to that of a conventional refractive lens. Different from a refractive lens that requires a plurality of lenses for chromatic aberration correction, the chromatic aberration can be corrected by changing the period of the diffraction structure of the lens. Therefore, by using a diffractive optical element, a more compact and high-performance lens unit can be designed.

[0003] In a multilayer diffractive optical element having a configuration in which diffractive optical elements formed of two different materials are in contact with each other at their grating surfaces, by forming one diffractive optical element with a material having a relatively high refractive index and a high Abbe number and the other diffractive optical element with a material having a relatively low refractive index and a low Abbe number, the occurrence of flare in the lens can be suppressed, and the chromatic aberration reduction effect can be fully utilized. At this time, if the optical characteristics are such that the refractive index difference between the two diffractive optical elements is larger at longer wavelengths, the chromatic aberration reduction effect can be obtained over a wide wavelength range.

[0004] In recent years, in order to obtain a chromatic aberration reduction effect over a wide wavelength range as described above, it has been proposed to add ITO (indium tin oxide) particles to a low Abbe number diffractive optical element in a multilayer diffractive optical element. For example, Patent Document 1 describes a resin composition containing ITO particles and a near-ultraviolet light-absorbing organic compound. According to this resin composition, by improving the refractive index on the short-wavelength side, the wavelength dependence of the refractive index is adjusted, and while suppressing the blending amount of ITO particles and increasing the transmittance in the near-infrared wavelength region, a cured product having a desired low refractive index and a low Abbe number can be obtained.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] International Publication No. 2020 / 171197 [Summary of the Invention] [Problems to be Solved by the Invention]

[0006] Conventionally, since general digital cameras and the like have been assumed as the application targets of lenses using diffractive optical elements, as described in Patent Document 1, in the visible light wavelength range visible to humans or in the near-infrared wavelength range of approximately 1.0 μm from visible light, a diffractive optical element with a low Abbe number having a high wavelength dependence of refractive index (high wavelength dispersion) and high transmittance has been developed. However, in recent years, the required resolution level of surveillance camera lenses has been increasing, and there has been a demand for diffractive optical elements corresponding to a wavelength range of approximately 1.0 to 1.7 μm in the wavelength range from near-infrared to short-wave infrared (hereinafter also referred to as the "NIR~SWIR wavelength range" in the present invention). Therefore, for the lenses to be applied, in order to obtain an action of reducing chromatic aberration in the NIR~SWIR wavelength range, a diffractive optical element having a wavelength dependence of refractive index and high transmittance desired as a high wavelength dispersion diffractive optical element in this wavelength range is required. However, according to the studies of the present inventors, in the technology described in Patent Document 1, since a near-ultraviolet light-absorbing organic compound and ITO particles having absorption at 1750 nm are used, the wavelength dispersion and transmittance are low in the NIR~SWIR wavelength range, and it has been found that it is difficult to achieve high wavelength dispersion and high transmittance in this wavelength range.

[0007] An object of the present invention is to provide a curable resin composition for lenses that can control the wavelength dependence of the refractive index to a desired level over the wavelength range from near-infrared to short-wave infrared and can obtain a cured product showing high transmittance in this wavelength range. Another object of the present invention is to provide a cured product obtained from this curable resin composition for lenses, as well as a diffractive optical element and a multilayer diffractive optical element containing this cured product.

Means for Solving the Problem

[0008] The above problems have been solved by the following means. [1] A curable resin composition for lenses, the composition containing a dye A having a maximum absorption at a wavelength of 520 to 620 nm, and the wavelength dispersion WD calculated by the following formula (X) of the cured product of the composition being 2.0×10 -5 or more, a curable resin composition for lenses. WD = (nC - n(1129)) / (1129 - 656) Formula (X) In the above formula, nC represents the refractive index at a wavelength of 656 nm, and n(1129) represents the refractive index at a wavelength of 1129 nm. [2] The curable resin composition for lenses according to [1], wherein the dye A is a tetraazaporphyrin dye. [3] The curable resin composition for lenses according to [2], wherein the dye A is a compound represented by the following general formula (α). [Chemical Formula] In the above formula, M represents Pd, Cu, Ni, Co, V(=O). Z 1 ~Z 8 is, in each combination of Z 1 and Z 2 , Z 3 and Z 4 , Z 5 and Z 6 , and Z 7 and Z 8 , one group constituting the combination is a substituted phenyl group and the other group is a hydrocarbon group having 1 to 6 carbon atoms. [4] The curable resin composition for lenses according to any one of [1] to [3], containing at least one of a polyfunctional (meth)acrylate monomer and a monofunctional (meth)acrylate monomer, and the glass transition temperature of the monofunctional (meth)acrylate monomer as a homopolymer being 100°C or higher. [5] The content of the above-mentioned dye A in the curable resin composition for lenses is 15% by mass or more, or contains a metal oxide having a maximum absorption at a wavelength of 1900 to 4000 nm, and the curable resin composition for lenses according to any one of [1] to [4]. 〔6〕 A cured product of the curable resin composition for lenses according to any one of [1] to [5]. 〔7〕 A diffractive optical element including the cured product according to [6] and having a surface formed with a diffractive grating shape formed by this cured product. 〔8〕 Including a first diffractive optical element and a second diffractive optical element, The first diffractive optical element is the diffractive optical element according to [7], A multilayer diffractive optical element in which the surface having a diffractive grating shape in the first diffractive optical element faces the surface having a diffractive grating shape of the second diffractive optical element.

[0009] In the present invention, regarding the representation of compounds and substituents, in addition to the compounds themselves and the substituents themselves, they are used in the meaning including their salts and their ions. For example, a carboxy group or the like may have a hydrogen atom dissociated to have an ionic structure or may have a salt structure. That is, in the present invention, the "carboxy group" is used in the meaning including a carboxylate ion or its salt. The same applies to other acidic groups. As the monovalent or polyvalent cations constituting the above salt structure, there is no particular limitation, and examples include inorganic cations and organic cations. Specifically, Na + 、Li + and K + and other cations of alkali metals such as Mg 2+ 、Ca 2+ and Ba 2+ and other cations of alkaline earth metals, and organic ammonium cations such as trialkylammonium cations and tetraalkylammonium cations. In the case of a salt structure, the type of the salt may be one kind, or two or more kinds may be mixed, and a group having a salt type and a free acid structure may be mixed in the compound, or a compound having a salt structure and a compound having a free acid structure may be mixed. In the present invention, when there are a plurality of substituents, linking groups, structural units, etc. (hereinafter referred to as substituents, etc.) represented by specific codes or formulas, or when a plurality of substituents, etc. are defined simultaneously, unless otherwise specified, each of the substituents, etc. may be the same as or different from each other (regardless of the presence or absence of the expression "each independently", each of the substituents, etc. may be the same as or different from each other). This also applies to the definition of the number of substituents, etc. Further, when a plurality of substituents, etc. are close to each other (especially when adjacent), unless otherwise specified, they may be linked to each other to form a ring. Further, unless otherwise specified, a ring, such as an alicyclic ring, an aromatic ring, or a heterocyclic ring, may be further condensed to form a fused ring. In the present invention, unless otherwise specified, for a double bond, when both E-type and Z-type exist in the molecule, either one or a mixture thereof may be used. Also, in the present invention, unless otherwise specified, when a compound has one or more asymmetric carbons, the stereochemistry of such asymmetric carbons may each independently take either the (R)-form or the (S)-form. As a result, the compound may be a mixture of stereoisomers such as optical isomers or diastereoisomers, or may be a racemate. Also, in the present invention, the representation of the compound includes those in which a part of the structure is changed within a range not impairing the effects of the present invention. Further, for a compound in which substitution or non-substitution is not specified, it means that it may have any substituent within a range not impairing the effects of the present invention. In the present invention, for a substituent (the same applies to a linking group and a ring) in which substitution or non-substitution is not specified, it means that it may have any substituent on the group within a range not impairing the desired effect, and the number of substituents that may be present is not particularly limited. For example, in the case of an "alkyl group", it means including both an unsubstituted alkyl group and a substituted alkyl group. Similarly, in the case of an "aryl group", it means including both an unsubstituted aryl group and a substituted aryl group. In the present invention, when defining the number of carbon atoms of a certain group, this number of carbon atoms means the number of carbon atoms of the entire group, unless otherwise specified in the present invention or this specification. That is, when this group has a substituent, it means the total number of carbon atoms including this substituent.

[0010] In the present invention, the numerical range represented by "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value. In the present invention, each component may be used alone or in combination of two or more. In the description of the content of each component in the curable resin composition for lenses of the present invention, when the curable resin composition for lenses contains a solvent, the content of each component is based on the component composition obtained by removing the solvent from the curable resin composition for lenses. For example, when the curable resin composition for lenses is composed of 20 parts by mass of a solvent, 40 parts by mass of component A, and 40 parts by mass of component B, a total of 100 parts by mass, the content of this component A in the composition is based on 80 parts by mass obtained by removing the solvent, so it is 50% by mass.

[0011] In the present invention, "(meth)acrylate" represents either acrylate or methacrylate, or both, and "(meth)acryloyl" represents either acryloyl or methacryloyl, or both. The monomer in the present invention is distinguished from an oligomer and a polymer, and refers to a compound having a weight average molecular weight of 1000 or less.

[0012] In the present invention, the term "aliphatic hydrocarbon group" means a group obtained by removing any one hydrogen atom from a straight-chain or branched alkane, a straight-chain or branched alkene, or a straight-chain or branched alkyne. In the present invention, the aliphatic hydrocarbon group is preferably an alkyl group obtained by removing any one hydrogen atom from a straight-chain or branched alkane. Examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, 1-methylbutyl group, 3-methylbutyl group, hexyl group, 1-methylpentyl group, 4-methylpentyl group, heptyl group, 1-methylhexyl group, 5-methylhexyl group, 2-ethylhexyl group, octyl group, 1-methylheptyl group, nonyl group, 1-methyloctyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group and the like. In the present invention, the aliphatic hydrocarbon group (unsubstituted) is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 12 carbon atoms.

[0013] In the present invention, the term "alkyl group" means a linear or branched alkyl group. Examples of the alkyl group include the above. The same applies to the alkyl group in a group containing an alkyl group (alkoxy group, alkoxycarbonyl group, acyl group, etc.). In the present invention, examples of the linear alkylene group include groups obtained by removing one hydrogen atom bonded to the terminal carbon atom from the linear alkyl groups among the above alkyl groups.

[0014] In the present invention, the alicyclic hydrocarbon ring means a saturated hydrocarbon ring (cycloalkane). Examples of the alicyclic hydrocarbon ring include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane and the like. In the present invention, the unsaturated hydrocarbon ring means a hydrocarbon ring having a carbon-carbon unsaturated double bond and not being an aromatic ring. Examples of the unsaturated hydrocarbon ring include indene, indane, fluorene.

[0015] In the present invention, the alicyclic hydrocarbon group means a cycloalkyl group obtained by removing one arbitrary hydrogen atom from cycloalkane. Examples of the alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecyl group, etc., and a cycloalkyl group having 3 to 12 carbon atoms is preferable. In the present invention, the cycloalkylene group represents a divalent group obtained by removing two arbitrary hydrogen atoms from cycloalkane. An example of the cycloalkylene group is a cyclohexylene group.

[0016] In the present invention, the aromatic ring means either one or both of an aromatic hydrocarbon ring and an aromatic heterocyclic ring.

[0017] In the present invention, the aromatic hydrocarbon ring means an aromatic ring formed only by carbon atoms. The aromatic hydrocarbon ring may be a monocyclic ring or a condensed ring. Examples of the aromatic hydrocarbon ring include benzene, naphthalene, anthracene, phenanthrene, etc. In the present invention, when the aromatic hydrocarbon ring is bonded to another ring, the aromatic hydrocarbon ring may be substituted on the other ring as a monovalent or divalent aromatic hydrocarbon group. Also, in the present invention, the unsubstituted aromatic hydrocarbon ring is preferably an aromatic hydrocarbon ring having 6 to 14 carbon atoms.

[0018] In the present invention, when the monovalent group is an aromatic hydrocarbon group (also referred to as an aryl group), it means a monovalent group obtained by removing one arbitrary hydrogen atom from an aromatic hydrocarbon ring. Examples of the monovalent aromatic hydrocarbon group include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthracenyl group, a 2-anthracenyl group, a 3-anthracenyl group, a 4-anthracenyl group, a 9-anthracenyl group, a 1-phenanthryl group, a 2-phenanthryl group, a 3-phenanthryl group, a 4-phenanthryl group, a 9-phenanthryl group, etc. Among these, a phenyl group, a 1-naphthyl group, and a 2-naphthyl group are preferable.

[0019] In the present invention, the divalent aromatic hydrocarbon group means a divalent group obtained by removing any two hydrogen atoms from an aromatic hydrocarbon ring. Examples of the divalent aromatic hydrocarbon group include divalent groups obtained by removing any one hydrogen atom from the above-mentioned monovalent aromatic hydrocarbon groups. Among these, a phenylene group is preferable, and a 1,4-phenylene group is more preferable.

[0020] In the present invention, the aromatic heterocyclic ring means an aromatic ring formed by carbon atoms and heteroatoms. Examples of the heteroatom include an oxygen atom, a nitrogen atom, and a sulfur atom. The aromatic heterocyclic ring may be a monocyclic ring or a condensed ring, and the number of atoms constituting the ring is preferably 5 to 20, more preferably 5 to 14. The number of heteroatoms in the atoms constituting the ring is not particularly limited, but is preferably 1 to 3, more preferably 1 to 2. Examples of the aromatic heterocyclic ring include furan, thiophene, pyrrole, imidazole, isothiazole, isoxazole, pyridine, pyrazine, quinoline, benzofuran, benzothiazole, benzoxazole, and the like. In the present invention, when the aromatic heterocyclic ring is bonded to another ring, the aromatic heterocyclic ring may be substituted on the other ring as a monovalent or divalent aromatic heterocyclic group.

[0021] In the present invention, when referring to a monovalent group as an aromatic heterocyclic group (also referred to as a heteroaryl group), it means a monovalent group obtained by removing any one hydrogen atom from an aromatic heterocyclic ring. Examples of the monovalent aromatic heterocyclic group include a furyl group, a thienyl group (preferably a 2-thienyl group), a pyrrolyl group, an imidazolyl group, an isothiazolyl group, an isoxazolyl group, a pyridyl group, a pyrazinyl group, a quinolyl group, a benzofuranyl group (preferably a 2-benzofuranyl group), a benzothiazolyl group (preferably a 2-benzothiazolyl group), a benzoxazolyl group (preferably a 2-benzoxazolyl group), and the like. Among these, a furyl group, a thienyl group, a benzofuranyl group, a benzothiazolyl group, and a benzoxazolyl group are preferable, and a 2-furyl group and a 2-thienyl group are more preferable.

[0022] In the present invention, the divalent aromatic heterocyclic group means a divalent group obtained by removing two arbitrary hydrogen atoms from an aromatic heterocyclic ring. Examples of the divalent aromatic heterocyclic group include divalent groups obtained by removing one arbitrary hydrogen atom from the above-mentioned monovalent aromatic heterocyclic groups. In the present invention, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom, a chlorine atom, or a bromine atom is preferable.

Effects of the Invention

[0023] By subjecting the curable resin composition for a lens of the present invention to a curing reaction, a cured product can be obtained which exhibits a desired wavelength dependence of refractive index and a high transmittance over a wavelength range from near-infrared to short-wave infrared. Further, the cured product of the present invention can exhibit a desired wavelength dependence of refractive index and a high transmittance over a wavelength range from near-infrared to short-wave infrared, and can be suitably used for a diffractive optical element and a multilayer diffractive optical element.

Modes for Carrying Out the Invention

[0024] <<Curable Resin Composition for a Lens>> The curable resin composition for a lens of the present invention contains a dye A having a maximum absorption at a wavelength of 520 to 620 nm, and the wavelength dispersion WD calculated by the following formula (X) of the cured product of this composition is 2.0×10 -5 or more. WD = (nC - n(1129)) / (1129 - 656) Formula (X) In the above formula, nC represents the refractive index at a wavelength of 656 nm, and n(1129) represents the refractive index at a wavelength of 1129 nm.

[0025] The wavelength dispersion WD calculated by the above formula (X) is calculated using the refractive index in the cured state of the curable resin composition for lenses of the present invention. If the curable resin composition for lenses of the present invention is cured, the production conditions of the cured product are not particularly limited. For example, when the curable resin composition for lenses of the present invention is photocured, for the cured product produced by the method described in Evaluation 1 of the examples below, the refractive index is measured and the above wavelength dispersion WD is calculated. The wavelength dispersion WD calculated by the above formula (X) is 3.0×10 -5 or more, preferably 5.0×10 -5 or more, more preferably 7.0×10 -5 or more.

[0026] By using the dye A having a maximum absorption at a wavelength of 520 to 620 nm in the curable resin composition for lenses of the present invention, the wavelength dispersion WD calculated by the above formula (X) of the cured product of this composition can be made 2.0×10 -5 or more, and it can exhibit a desired wavelength dependence (high wavelength dispersion) of the refractive index over the wavelength range of NIR to SWIR. Further, as described in the above Patent Document 1, since it does not contain ITO particles having an absorption at 1750 nm, it can exhibit a high transmittance over the wavelength range of NIR to SWIR. Compared with the near-ultraviolet light-absorbing organic compound described in the above Patent Document 1, a compound having an absorption in the visible light region has a high planarity in order to shift the absorption to a longer wavelength, and has a structure in which the π-conjugated system is long. On the other hand, a compound (solute) having a high planarity and a long π-conjugated system is generally inferior in solubility in a resin (solvent). Therefore, the resin composition described in the above Patent Document 1 does not assume using a compound having an absorption in the visible light region instead of the near-ultraviolet light-absorbing organic compound.

[0027] The curable resin composition for lenses of the present invention is a curable composition, a composition capable of obtaining a cured product (resin) by curing, and means a composition for lens applications. The curable resin composition for lenses of the present invention may contain other components described below in addition to the above components. The following components will be described.

[0028] <Dye A having a maximum absorption at a wavelength of 520 to 620 nm> The curable resin composition for lenses of the present invention contains a dye A (hereinafter also referred to as "dye A") having a maximum absorption at a wavelength of 520 to 620 nm. The above "having a maximum absorption at a wavelength of 520 to 620 nm" means that the absorption maximum wavelength of dye A measured in the cured state of the curable resin composition for lenses of the present invention (that is, the state of the cured product obtained from the curable resin composition for lenses of the present invention) exists in the wavelength range of 520 to 620 nm. Specifically, it is measured in the state of the cured product under the conditions described in the section of absorbance measurement and light resistance test in Evaluation 2 of the examples described later. Also, when there are a plurality of absorption maximum wavelengths in the region of 520 to 620 nm, it is sufficient that the absorption maximum wavelength showing the largest absorbance exists in the above wavelength region. For example, when dye A is a compound represented by the following general formula (α) and is a mixture of 2 to 4 isomers described later, the maximum absorption of the above dye A means the maximum absorption showing the largest absorbance as a mixture.

[0029] The above dye A is not particularly limited as long as it has a maximum absorption at a wavelength of 520 to 620 nm, and examples thereof include tetraazaporphyrin dyes and merocyanine dyes.

[0030] Merocyanine dyes are usually compounds represented by the following general formula (β). That is, an amino group represented by -NR 1 R 2 substitutes one of the carbon atoms constituting the carbon-carbon double bond, and a heterocycle is bonded to the other carbon atom via a linking group X containing a carbon-carbon unsaturated bond.

[0031]

Chemical formula

[0032] In the above formula, R 1 ~R4 represents a hydrogen atom or a substituent, and R 1 and R 2 , and R 2 and R 3 may be bonded to each other to form a ring structure. X represents a linking group containing a carbon-carbon unsaturated bond, preferably a linking group containing a carbon-carbon double bond, and more preferably a linking group in which a carbon-carbon double bond and a carbon-carbon single bond are alternately linked such that the linking portion with Y is a carbon-carbon double bond. Y represents a heterocyclic ring.

[0033] The tetraazaporphyrin dye is a compound having a tetraazaporphyrin skeleton structure. From the viewpoint of further improving the wavelength dispersion WD calculated by the above formula (X), the above dye A is preferably a tetraazaporphyrin dye, more preferably a tetraazaporphyrin metal complex dye in which tetraazaporphyrin is coordinated to a metal atom, and even more preferably a compound represented by the following general formula (α).

[0034]

Chemical formula

[0035] In the above formula, M represents Pd, Cu, Ni, Co, V(=O). Z 1 ~Z 8 is such that in each combination of two groups of Z 1 and Z 2 , Z 3 and Z 4 , Z 5 and Z 6 , and Z 7 and Z 8 , one group α constituting the combination is a phenyl group having a substituent (substituted phenyl group), and the other group β is a hydrocarbon group having 1 to 6 carbon atoms. In the above formula, the nitrogen atoms located above and below M on the paper surface are coordinated to M by non-bonding electron pairs. The same applies to the exemplified compounds and the compounds used in the examples described later.

[0036] Among the above Ms, Pd, Cu, Ni, and Co are divalent metals, and V(=O) is a metal having an oxy group. When M is V(=O), it binds as represented by the compound (TAP-5) described later. The above M is preferably Pd, Cu, Ni, Co, or V(=O), and more preferably Pd or Cu.

[0037] In the compound represented by the above general formula (α), the above Z 1 and Z 2 , Z 3 and Z 4 , Z 5 and Z 6 , and, Z 7 and Z 8 In each combination consisting of two groups of the above, depending on which of the two groups constituting the combination becomes the group α, four types of isomers are included. As described in paragraph

[0045] of JP-A-2012-121821, for the convenience of synthesizing the compound represented by the above general formula (α), it is usually obtained as a mixture of four types of isomers. In the present invention, the compound represented by the above general formula (α) may contain at least one of the four types of isomers, and may be a mixture of two to four types of isomers.

[0038] (Group α) In the above group α, examples of the substituent in the substituted phenyl group include a halogen atom, a nitro group, a cyano group, a hydroxy group, an alkyl group, and an alkoxy group, and a halogen atom or an alkyl group is preferable. As the halogen atom, a fluorine atom, a chlorine atom or a bromine atom is preferable, a fluorine atom or a chlorine atom is more preferable. As the alkyl group, an alkyl group having 1 to 3 carbon atoms is preferable, and as the alkoxy group, an alkoxy group having 1 to 3 carbon atoms is preferable. The alkyl group may be substituted with a substituent, and examples thereof include a substituent substituted with a halogen atom or a dialkylamino group, and a fluorinated alkyl group or a dialkylaminoalkyl group is preferable. The substitution position of the substituent possessed by the phenyl group is not particularly limited, but it is preferable that at least one of the ortho position and the para position of the phenyl group is substituted, more preferably at least one of the ortho positions of the phenyl group is substituted, and even more preferably only one of the ortho positions of the phenyl group has a substituent. Further, when the phenyl group of the above group α has two adjacent substituents, these substituents may be bonded to each other to form a ring. The formed ring preferably has 5 or 6 ring members, and may be an aliphatic ring or an aromatic ring, but an aromatic ring is preferable, and examples thereof include a benzene ring. As the substituent in which the phenyl group has two adjacent substituents and these substituents are bonded to each other to form a ring, a naphthyl group is preferable, and a 1-naphthyl group is more preferable. As the above group α, a halogen atom, a phenyl group having an unsubstituted alkyl group or a fluorinated alkyl group as a substituent, or a naphthyl group is preferable, and 2-fluorophenyl group, 4-fluorophenyl group, 2,4-difluorophenyl group, 2,6-difluorophenyl group, 2-chlorophenyl group, 4-chlorophenyl group, 2,4-dichlorophenyl group, 2,6-dichlorophenyl group, 2-bromophenyl group, 4-bromophenyl group, 2,4-dibromophenyl group, 2,6-dibromophenyl group, 2-methylphenyl group, 4-methylphenyl group, 2,4-dimethylphenyl group, 2,6-dimethylphenyl group, 2-trifluoromethylphenyl group, 4-trifluoromethylphenyl group, 2,4-bis(trifluoromethyl)phenyl group, 2,6-bis(trifluoromethyl)phenyl group or 1-naphthyl group is more preferable.

[0039] (Base β) In the above base β, as the hydrocarbon group having 1 to 6 carbon atoms, an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms is preferable. As the above base β, a linear, branched or cyclic alkyl group such as methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, 2-methylbutyl group, 1-methylbutyl group, neo-pentyl group, 1,2-dimethylpropyl group, 1,1-dimethylpropyl group, cyclopentyl group, n-hexyl group, 4-methylpentyl group, 3-methylpentyl group, 2-methylpentyl group, 1-methylpentyl group, 3,3-dimethylbutyl group, 2,3-dimethylbutyl group, 1,3-dimethylbutyl group, 2,2-dimethylbutyl group, 1,2-dimethylbutyl group, 1,1-dimethylbutyl group, 3-ethylbutyl group, 2-ethylbutyl group, 1-ethylbutyl group, 1,1,2-trimethylpropyl group, 1-ethyl-2-methylpropyl group or cyclohexyl group is preferable. Among these, a tert-butyl group or a cyclohexyl group is more preferable.

[0040] Examples of the merocyanine dye include the compound represented by formula (MC1) described in JP-A-2017-68221 and the compound represented by general formula (II) described in JP-A-2006-188582. Examples of the tetraazaporphyrin dye include the following compounds (TAP-1) to (TAP-8). The wavelengths described in the following compounds mean the maximum absorption wavelengths. The maximum absorption wavelengths described in this paragraph and the next paragraph mean the maximum absorption wavelengths measured for a solution in which the compound is dissolved in a solvent. By using these compounds, the cured product obtained from the curable resin composition for lenses of the present invention can exhibit a maximum absorption wavelength in the range of 520 to 620 nm.

[0041] [Chemical formula]

[0042] Examples of commercially available products of the above-mentioned dye A include FDG-002 (maximum absorption wavelength: 525 nm, merocyanine dye), FDG-003 (maximum absorption wavelength: 547 nm, merocyanine dye), FDG-004 (maximum absorption wavelength: 578 nm), FDG-005 (maximum absorption wavelength: 583 nm, tetraazaporphyrin dye), and FDG-007 (maximum absorption wavelength: 594 nm, tetraazaporphyrin dye), all of which are manufactured by Yamada Chemical Industry Co., Ltd. There are no particular restrictions on the method of obtaining the above-mentioned dye A. Commercially available products described above may be used, or those obtained by synthesis may be used. When obtaining by synthesis, there are no particular restrictions on the manufacturing method of dye A, and it can be manufactured according to conventional methods with reference to the methods described in JP-A-2012-121821 and the examples described later.

[0043] The content of the above-mentioned dye A in the curable resin composition for lenses of the present invention may be adjusted according to the maximum absorption wavelength of dye A and also according to components other than dye A that may be contained, such as the metal oxide T described later. Typically, the content of the above-mentioned dye A in the curable resin composition for lenses of the present invention is preferably 1 to 30% by mass, more preferably 2 to 25% by mass, still more preferably 5 to 20% by mass, and particularly preferably 7 to 20%. When the metal oxide T described later is contained, the content of dye A can be reduced. For example, it can be 1 to 25% by mass, preferably 1 to 20% by mass, and more preferably 1 to 15% by mass. By setting the content of the above-mentioned dye A within the above-mentioned preferred range, the effect of improving the wavelength dispersion characteristics in the wavelength range of NIR to SWIR can be sufficiently obtained.

[0044] Two or more kinds of the above-mentioned dye A may be contained in the curable resin composition for lenses of the present invention. When two or more kinds of the above-mentioned dye A are contained, it is preferable that the total content is within the above-mentioned range.

[0045] <Other Components> The curable resin composition for lenses of the present invention may further contain other components in addition to the above pigment A. Specific examples of the other components include (meth)acrylate monomer compounds, metal oxides, polymer dispersants, polymerization initiators, polymers, and the like.

[0046] [[(meth)acrylate monomer]] The curable resin composition for lenses of the present invention may contain a (meth)acrylate monomer. The (meth)acrylate monomer may be a polyfunctional (bifunctional or higher) (meth)acrylate monomer compound having two or more (meth)acryloyl groups in the molecule, or a monofunctional (meth)acrylate monomer having one (meth)acryloyl group in the molecule. There is no particular upper limit on the number of (meth)acryloyl groups possessed by the (meth)acrylate monomer, and for example, it can be 8-functional or less. Specific examples of the (meth)acrylate monomer include, for example, monomer 1 (phenoxyethyl acrylate), monomer 2 (benzyl acrylate), monomer 3 (tricyclodecane dimethanol diacrylate), and monomer 4 (dicyclopentanyl acrylate). Also, M-1 (1,6-hexanediol diacrylate), M-2 (1,6-hexanediol dimethacrylate), M-3 (benzyl acrylate), M-4 (isobornyl methacrylate), M-5 (dicyclopentanyl methacrylate), M-6 (dodecyl methacrylate), M-7 (2-ethylhexyl acrylate), M-8 (2-hydroxyethyl acrylate), M-9 (hydroxypropyl acrylate), M-10 (4-hydroxybutyl acrylate), M-11 (2-ethylhexyl methacrylate), and M-12 (decyl methacrylate) can be mentioned. In addition, (meth)acrylate monomers described in paragraphs 0037 to 0046 of JP-A-2012-107191 and the like can be mentioned. Among the above, as the (meth)acrylate monomer, 2-ethylhexyl methacrylate, decyl methacrylate or dodecyl methacrylate is preferable, and from the viewpoints of excellent light resistance and transparency, decyl methacrylate or dodecyl methacrylate is more preferable. The molecular weight of the (meth)acrylate monomer is preferably 100 to 500.

[0047]

Chemical formula

[0048]

Chemical formula

[0049] There is no particular limitation on the method for obtaining the (meth)acrylate monomer, and it may be obtained commercially or synthesized by a conventional method. When obtaining commercially, for example, Biscoat #192 PEA (the above monomer 1) (manufactured by Osaka Organic Chemical Industry Co., Ltd.), Biscoat #160 BZA (the above monomer 2) (manufactured by Osaka Organic Chemical Industry Co., Ltd.), Light Ester Bz (the above monomer 2) (manufactured by Kyoeisha Chemical Co., Ltd.), A-DCP (the above monomer 3) (manufactured by Shin-Nakamura Chemical Co., Ltd.), FA-513AS (the above monomer 4) (manufactured by Hitachi Chemical Co., Ltd.), A-HD-N (the above M-1) (manufactured by Shin-Nakamura Chemical Co., Ltd.), HD-N (the above M-2) (manufactured by Shin-Nakamura Chemical Co., Ltd.), FA-BZA (the above M-3) (manufactured by Hitachi Chemical Co., Ltd.), Light Ester IB-X (the above M-4) (manufactured by Kyoeisha Chemical Co., Ltd.), FA-513M (the above M-5) (manufactured by Hitachi Chemical Co., Ltd.), Light Ester L (the above M-6) (manufactured by Kyoeisha Chemical Co., Ltd.), 2EHA (the above M-7) (manufactured by Toagosei Co., Ltd.), HEA (the above M-8) (manufactured by Osaka Organic Chemical Industry Co., Ltd.), Light Ester HOP-A(N) (the above M-9) (manufactured by Kyoeisha Chemical Co., Ltd.), 4-HBA (the above M-10) (manufactured by Osaka Organic Chemical Industry Co., Ltd.), DCP (the above M-13) (manufactured by Shin-Nakamura Chemical Co., Ltd.) can be preferably used.

[0050] In addition, when it is necessary to increase the hardness or abrasion resistance of the surface of the cured product, the curable resin composition for lenses preferably contains a polyfunctional (meth)acrylate monomer having three or more (meth)acryloyl groups in the molecule. By including a polyfunctional (meth)acrylate monomer having three or more (meth)acryloyl groups in the molecule, the crosslink density of the cured product can be effectively improved, so that the surface hardness and abrasion resistance can be increased while maintaining a high partial dispersion ratio. The upper limit of the number of (meth)acryloyl groups of the polyfunctional (meth)acrylate monomer having three or more (meth)acryloyl groups in the molecule is not particularly limited, but is preferably 8, and more preferably 6. When commercially available, for example, A-TMPT (monomer 5), A-TMMT (monomer 6), AD-TMP (monomer 7), A-DPH (monomer 8) (manufactured by Shin-Nakamura Chemical Co., Ltd.) can be preferably used.

[0051]

Chemical formula

[0052] The curable resin composition for lenses of the present invention contains at least one of a polyfunctional (meth)acrylate monomer and a monofunctional (meth)acrylate monomer, and it is preferable that the glass transition temperature (Tg) of the monofunctional (meth)acrylate monomer as a homopolymer is 100°C or higher. In particular, in the curable resin composition for lenses of the present invention, by combining a tetraazaporphyrin dye as dye A having a maximum absorption at a wavelength of 520 to 620 nm and at least one of a bifunctional or higher (meth)acrylate monomer and a monofunctional (meth)acrylate monomer having a Tg of 100°C or higher as a homopolymer as components constituting the resin in the cured product, a decrease in absorbance due to light irradiation can be suppressed and the light resistance can be further improved. Although this is an estimate, it is considered as follows. The curable resin composition for lenses of the present invention containing at least one difunctional or higher (meth)acrylate monomer and at least one monofunctional (meth)acrylate monomer having a glass transition temperature (Tg) of the homopolymer of 100°C or higher can effectively increase the hardness of the resulting cured product. Dye molecules in the cured product excited by light irradiation usually deactivate through a path of decomposition by reaction with other molecules and a path of deactivation to the ground state by thermal deactivation. However, for tetraazaporphyrin dyes, since they hardly undergo the above thermal deactivation path and undergo the above decomposition path, by making the curable resin composition for lenses of the present invention a composition containing at least one difunctional or higher (meth)acrylate monomer and at least one monofunctional (meth)acrylate monomer having a glass transition temperature (Tg) of the homopolymer of 100°C or higher, it is considered that the decomposition of the dye by reaction with other molecules as described above can be suppressed and excellent light resistance can be exhibited.

[0053] The Tg of the homopolymer obtained from the above monofunctional (meth)acrylate monomer means, for example, the Tg obtained by dynamic viscoelasticity measurement (for example, using Rheogel-E4000 (trade name) manufactured by UBM, measurement in the measurement temperature range of -50°C to 250°C) for the homopolymer obtained by curing the monofunctional (meth)acrylate monomer. Examples of the monofunctional (meth)acrylate monomer having a Tg of the homopolymer of 100°C or higher include the above-mentioned monomer 4 (Tg 120°C), M-4 (Tg 180°C), and M-5 (Tg 175°C). For the Tg of the above homopolymer, for example, the values described in Polymer Handbook (4th Edition, published by Wiley-Interscience) can be referred to. The Tg of the homopolymer exhibited by the above monofunctional (meth)acrylate monomer is preferably 105°C or higher, more preferably 110°C or higher, and even more preferably 115°C or higher. There is no particular limitation on the upper limit value, but 250°C or lower is practical.

[0054] When the curable resin composition for lenses contains a (meth)acrylate monomer, the content of the (meth)acrylate monomer in the curable resin composition for lenses is preferably 20 to 99% by mass, more preferably 30 to 97% by mass, and even more preferably 40 to 95% by mass. By adjusting the amount of the (meth)acrylate monomer in the curable resin composition for lenses, the function of relaxing the stress when the cured product undergoes thermal changes can be adjusted.

[0055] 〔Metal oxide〕 The curable resin composition for lenses of the present invention preferably contains a metal oxide having a maximum absorption at a wavelength of 1900 to 4000 nm (hereinafter, also referred to as "metal oxide T"). By combining the above-mentioned dye A having a maximum absorption at a wavelength of 520 to 620 nm and a metal oxide having a maximum absorption at a wavelength of 1900 to 4000 nm, it is possible to improve the wavelength dispersion WD calculated by the above formula (X) while reducing the content of the dye. The metal oxide T is not particularly limited as long as it has a maximum absorption at a wavelength of 1900 to 4000 nm, and examples thereof include antimony-doped tin oxide and tin-doped indium oxide (in the present invention, also referred to as "indium tin oxide"), and indium tin oxide (in the present invention, also abbreviated as "ITO") is preferred. From the viewpoint of suppressing polarization at XY, the metal oxide T is preferably metal oxide particles, and more preferably ITO particles. Regarding the particle size, the description related to the particle size of the following ITO particles can be applied. The maximum absorption wavelength of the metal oxide T is preferably in the range of 1950 to 3800 nm, and more preferably in the range of 2000 to 3600 nm. Hereinafter, the ITO particles will be described in detail. It should be noted that the description of the ITO particles in the following description related to the metal oxide or metal oxide particles can also be applied by substituting the ITO particles with the metal oxide or metal oxide particles.

[0056] (Indium tin oxide particles (ITO particles)) The particle diameter of the ITO particles is preferably 5 to 50 nm. By setting it to 50 nm or less, it is possible to prevent a decrease in transmittance due to Rayleigh scattering. Also, at 5 nm or more, it is possible to manufacture ITO particles without technical difficulties. The particle diameter of the ITO particles can be determined by averaging the particle diameters measured by a transmission electron microscope (TEM). That is, for one particle in the electron micrograph taken by TEM, the minor axis and the major axis are measured, and the average value is determined as the particle diameter of one particle. In the present invention, the particle diameters of 500 particles are randomly determined, and the average value (arithmetic mean) of these 500 particle diameters is calculated and used as the average primary particle diameter (particle diameter of the ITO particles).

[0057] When the curable resin composition for a lens of the present invention contains ITO particles, it is preferable that the curable resin composition for a lens of the present invention is prepared by mixing the ITO particles in a dispersed state in a solvent with the above-mentioned dye A and a polymer (dispersant) described later. After mixing, the solvent used for dispersing the ITO particles may or may not be removed from the curable resin composition for a lens by distillation or the like, but it is preferably removed.

[0058] The ITO particles can be made into surface-modified ITO particles to improve the dispersibility in a solvent. The surface modification of the ITO particles is preferably performed, for example, using a monocarboxylic acid having 6 to 20 carbon atoms as a surface modification compound. The surface modification of the ITO particles with the monocarboxylic acid is preferably carried out by the carboxy group derived from the monocarboxylic acid forming an ester bond with the oxygen atom on the surface of the ITO particles, or by the carboxy group coordinating to the In or Ti atom. Examples of the monocarboxylic acid having 6 to 20 carbon atoms include oleic acid (18 carbon atoms), stearic acid (18 carbon atoms), palmitic acid (16 carbon atoms), myristic acid (14 carbon atoms), or decanoic acid (10 carbon atoms), and oleic acid (18 carbon atoms) is preferable.

[0059] In the curable resin composition for lenses, the site derived from the surface modification compound in the above surface-modified ITO particles (for example, a group derived from a monocarboxylic acid having 6 to 20 carbon atoms) may be directly bonded to the ITO particles, a part of it may be replaced by a group derived from a polymer described later, or all of it may be replaced by a group derived from a polymer described later. In the curable resin composition for lenses of the present invention, it is preferable that both a site derived from a surface modification compound (for example, a group derived from a monocarboxylic acid having 6 to 20 carbon atoms) and a group derived from a polymer described later are bonded to the ITO particle surface.

[0060] As the above solvent, it is preferable that the component of the polar term (δp) of the solubility parameter (SP value) is 0 to 6 MPa (1 / 2) is the solvent. The component (δp) of the polar term of the SP value is a value calculated by the Hansen solubility parameter. The Hansen solubility parameter is composed of the intermolecular dispersion force energy (δd), the intermolecular polar energy (δp), and the intermolecular hydrogen bonding energy (δh). In the present invention, the Hansen solubility parameter is assumed to be calculated using HSPiP (version 4.1.07) software. Specifically, the solvent is preferably toluene (1.4), xylene (1.0) or hexane (0), and toluene is more preferable. The values in parentheses are the values of δp, and the unit is MPa (1 / 2) is.

[0061] The method for producing the ITO particles is not particularly limited. For example, it can be produced according to the procedure described in ACS Nano 2016, 10, 6942-6951. According to the procedure of this reference, a dispersion of surface-modified ITO particles can be obtained. Specifically, a solution obtained by mixing a monocarboxylic acid having 6 to 20 carbon atoms, an indium salt (for example, indium acetate), and a tin salt (for example, tin acetate) is dropped into an alcohol (a long-chain alcohol such as oleyl alcohol) heated to a high temperature, and the high temperature is maintained to form particles. Thereafter, a poor solvent (such as a lower alcohol like ethanol) with low solubility of the polymer is added to precipitate the particles, and then the supernatant is removed. By redispersing in a solvent such as toluene described above, a dispersion of surface-modified ITO particles can be obtained.

[0062] When the curable resin composition for lenses of the present invention contains a metal oxide T (more preferably ITO particles), the content ratio of the metal oxide T (more preferably ITO particles) in the curable resin composition for lenses of the present invention is preferably 10 to 65% by mass, more preferably 15 to 60% by mass, and even more preferably 20 to 55% by mass.

[0063] From the viewpoint of further improving the wavelength dispersion WD calculated by the above formula (X) of the cured product of the curable resin composition for lenses of the present invention, the content of the above-mentioned dye A in the composition is 15% by mass or more, or it preferably contains a metal oxide having a maximum absorption at a wavelength of 1900 to 4000 nm.

[0064] 〔Polymer (Dispersant)〕 The curable resin composition for lenses of the present invention preferably contains a polymer (hereinafter, this polymer is also referred to as "polymer dispersant") that functions as a dispersant for the above metal oxide in the curable resin composition for lenses. The polymer dispersant is not particularly limited as long as it has a function of dispersing the above metal oxide (preferably metal oxide particles) in the curable resin composition for lenses of the present invention. However, it preferably has a structural unit represented by the following general formula (P) and has an acidic group at one end of the polymer chain (hereinafter, referred to as "polymer dispersant P").

[0065]

Chemical formula

[0066] In the above formula, L P represents a single bond or a divalent linking group, Ar P represents an aryl group, and R P1 represents a hydrogen atom or a methyl group. However, ArP does not contain the above acidic group. * indicates a bonding site for incorporation into the polymer main chain. Ar P As the aryl group of, a phenyl group, 1-naphthyl group or 2-naphthyl group is preferable. Examples of the substituent that the aryl group may have include an alkyl group, an alkoxy group and an aryl group. R P1 The methyl group that can be adopted as preferably does not contain the above acidic group as a substituent.

[0067] The above polymer dispersant P has an acidic group that is an adsorption group for a metal oxide T such as ITO particles at one end of the polymer chain, and also has a structural unit represented by the general formula (P) containing Ar P (aryl group). The curable resin composition for a lens of the present invention contains the above polymer dispersant P together with the above metal oxide T such as ITO particles and the above dye A, so that Ar P in the side chain of the polymer dispersant P and the π-π interaction between the aromatic ring of the above dye A, the interaction between the acidic group of the polymer dispersant P and the above metal oxide T such as ITO particles, etc. enhance the compatibility of the two components, and the preparation time and medium- and long-term dispersion stability of the composition can be effectively enhanced.

[0068] The acidic group that the polymer dispersant P has at one end of the polymer chain is preferably selected from a carboxy group (-COOH), a phosphono group (-P(=O)(OH)2), a phosphonoxy group (-OP(=O)(OH)2), a hydrohydroxyphosphoryl group (-PH(=O)(OH)), a sulfino group (-S(=O)(OH)), a sulfo group (-S(=O)2(OH)) and a sulfanyl group (-SH). The other end of the polymer chain in the above polymer dispersant P is not particularly limited as long as the desired dispersibility can be obtained, but preferably does not have an acidic group, and this other end can be, for example, a hydrogen atom, an alkyl group or the like. Incidentally, for convenience of synthesis, the polymer dispersant P may contain a small amount of a polymer having acidic groups at both ends of the polymer chain in addition to the polymer having an acidic group at one end of the polymer chain. However, as long as the polymer dispersant P is substantially composed of a polymer having an acidic group at one end of the polymer chain, even if the polymer having acidic groups at both ends is contained, the dispersion stability of the composition can be enhanced. Further, the polymer dispersant P may contain an acidic group in the side chain of the polymer chain within a range where a desired dispersibility can be obtained. However, when an acidic group is contained in the side chain, since the ITO particles are likely to aggregate, it is preferably not contained. The acidic group exhibits an adsorption action on the surface of the indium tin oxide particles by at least one of ionic bond, covalent bond, hydrogen bond or coordination bond. From the viewpoint of further improving the medium- and long-term dispersion stability, the acidic group is more preferably a carboxy group, a phosphono group or a phosphonoxy group, and even more preferably a carboxy group.

[0069] In the general formula (P), L P Examples of the divalent linking group that can be taken as include an alkylene group, *-(alkylene-O) n -, and ester (-O-(C=O)-). The number of carbon atoms in the above alkylene moiety is preferably 1 to 4, more preferably 1 to 2. n is preferably 1 to 10, more preferably 1 to 6, even more preferably 1 to 2, and particularly preferably 1. L P is preferably a single bond, an alkylene group or *-(alkylene-O) n -, more preferably a single bond, -CH2-, *-CH2O- or *-CH2CH2O-. In the description of the above L P *, indicates a bond on the side that does not bond to Ar P .

[0070] The main chain backbone portion of the polymer dispersant P may be linear or branched. Among them, being linear is preferred.

[0071] The above polymer dispersant may have a structural unit represented by the following general formula (P2) in addition to the structural unit represented by the above general formula (P) within the range where the desired dispersibility can be obtained.

[0072]

Chemical formula

[0073] In the above formula, R P3 represents a hydrogen atom or a methyl group, and R P2 represents a monovalent substituent. However, R P2 is not -L P -Ar P in the above general formula (P). * represents a bonding site for incorporation into the polymer main chain. R P2 is preferably an alkyl group or an alicyclic hydrocarbon group, and an alkyl group is preferred. The monovalent substituent that can be adopted as R P2 is preferably free of the above acidic group from the viewpoint of suppressing the aggregation of ITO particles. The carbon number of this alkyl group is preferably 1 to 20, more preferably 1 to 12, and even more preferably 1 to 8. R P3 is preferably free of the above acidic group as a substituent.

[0074] The above polymer dispersant P preferably consists of a structural unit represented by the above general formula (P) in terms of the main chain structure and side chain structure, and also preferably consists of a structural unit represented by the above general formula (P) and a structural unit represented by the above general formula (P2). Also, within the range where the desired dispersibility can be obtained, it may have a structural unit different from the structural units represented by each of the general formulas (P) and (P2) (a structural unit derived from a monomer having an ethylenic unsaturated bond that is not the structural unit represented by each of the general formulas (P) and (P2)). When the above polymer dispersant P is a copolymer, it may be either random or block.

[0075] The proportion of the general formula (P) in all the constituent units constituting the polymer dispersant P is not particularly limited, but for example, 5 mol% or more is preferable. From the viewpoint of further improving the dispersion stability in the medium and long term, the proportion is more preferably 10 mol% or more, and even more preferably 15 mol% or more. There is no particular limitation on the upper limit value of this proportion, and it is also preferable that all the constituent units in the polymer dispersant P are the constituent units represented by the general formula (P). When the polymer dispersant P contains a constituent unit represented by the general formula (P2), the proportion of the general formula (P2) in all the constituent units constituting the polymer dispersant P is preferably, for example, 95 mol% or less, more preferably 90 mol% or less, and even more preferably 85 mol% or less. There is no particular limitation on the lower limit value of this proportion when the constituent unit represented by the general formula (P2) is contained, and it may be more than 0 mol%. The constituent units constituting the polymer dispersant P mean the constituent units derived from the monomer components, and can be calculated from the content ratio of the monomer components. The content of the constituent unit represented by the general formula (P) in the polymer dispersant P is not particularly limited, but for example, 20% by mass or more is preferable. From the viewpoint of further improving the dispersion stability in the medium and long term, the proportion is more preferably 30% by mass or more, and even more preferably 50% by mass or more. There is no particular limitation on the upper limit value of this proportion, and it is also preferable that all the constituent units in the polymer dispersant P are the constituent units represented by the general formula (P).

[0076] The polymer dispersant P preferably has, as the structural part containing the acidic group, a structural part represented by the following general formula (PA) at one end of the polymer chain.

[0077]

Chemical formula

[0078] In the above formula, A P represents an acidic group, LL represents a single bond or a linking group with a valence of x + 1, x is an integer from 1 to 8. * indicates the bonding position with the remaining part of the polymer dispersant P.

[0079] A P The acidic group that can be adopted as such is synonymous with the acidic group described above, and the preferred forms are also the same. Examples of the (x + 1)-valent linking group LL that can be adopted include a (x + 1)-valent saturated fatty acid hydrocarbon group (a group obtained by removing x + 1 hydrogen atoms from an alkane) and a (x + 1)-valent alicyclic hydrocarbon group (a group obtained by removing x + 1 hydrogen atoms from an alicyclic hydrocarbon). Further, examples include a (x + 1)-valent group composed of a combination of these groups and a bond selected from -O-, -(C=O)-O-, and -(C=O)-NH-. LL is preferably a group composed of a (x + 1)-valent alkane or a combination of a (x + 1)-valent alkane and -O-. x is preferably an integer of 1 to 6, more preferably an integer of 2 to 4, and even more preferably an integer of 2.

[0080] The structure represented by the above general formula (PA) is preferably the structure represented by the following general formula (PA1). From the viewpoint of improving the adsorptivity to the metal oxide T such as ITO particles by having a carboxy group in a neighboring site, it is more preferably the structure represented by the following formula (PA2).

[0081]

Chemical formula

[0082] LL and x in the above formula have the same meanings as LL and x in the above general formula (PA). * indicates the bonding position with the remaining site of the polymer dispersant.

[0083] The acid value of the above polymer dispersant is preferably 2.0 mgKOH / g or more and less than 100 mgKOH / g, more preferably 2.0 mgKOH / g or more and less than 70 mgKOH / g, and even more preferably 10 mgKOH / g or more and less than 50 mgKOH / g. The acid value means the number of mg of potassium hydroxide required to neutralize the acidic components present in 1 g of the polymer. By adjusting the molecular weight of the polymer dispersant and the number of acidic groups such as carboxyl groups so that the acid value of the polymer dispersant falls within the above-preferred range, it is possible to achieve both an appropriate viscosity and particle dispersion performance as a curable resin composition for lenses. When the acid value of the polymer dispersant is 2.0 mgKOH / g or more, the polymer dispersant P can be sufficiently adsorbed and dispersed on the metal oxide T such as ITO particles. Further, when the acid value of the polymer dispersant is less than the above-preferred upper limit value, the number of adsorbing groups and the molecular size can be adjusted, and the viscosity of the curable resin composition for lenses can be adjusted to an appropriate range.

[0084] The weight average molecular weight of the above polymer dispersant is not particularly limited, but for example, 1000 to 30000 is preferable, 1000 to 20000 is more preferable, 1000 to 15000 is even more preferable, and 1000 to 13000 is particularly preferable from the viewpoint of further improving the long-term dispersion stability. By setting it to 1000 or more, the incorporation of bubbles generated during the curing of the curable resin composition for lenses can be suppressed. Further, by setting it to be equal to or less than the above-preferred upper limit value, the fluidity is less likely to decrease even when the amount necessary for the dispersion of the metal oxide T such as ITO particles is added to the curable resin composition for lenses, and when forming a cured product having a diffraction grating shape, air gaps are less likely to occur at the steps of the mold. The weight average molecular weight of the polymer dispersant is a value measured by the method described in the examples below.

[0085] Specific examples of the above polymer dispersant P are listed below, but are not limited to these structures. All of the specific examples shown below are homopolymers, but may be copolymers and may have structural units other than the structural units represented by the above general formula (P). Further, the specific examples shown below have a structural part containing an acidic group at one end, and the other end is a methyl group, but may be a group other than the methyl group. n is synonymous with n in the above general formula (P) P and has the same meaning as n in L.

[0086]

Chemical formula

[0087] The above polymer dispersant P can be produced by a conventional method. For example, it can be produced by reacting a (meth)acrylate monomer with a compound capable of terminating the polymerization reaction of this monomer and having an acidic group (preferably a carboxyl group). Examples of such a compound include mercaptosuccinic acid, mercaptosuccinic acid, or mercaptomalonic acid, and mercaptosuccinic acid is preferred. For a polymer dispersant having a phosphonooxy group at one end, the method described in JP-A-6-20261 can be referred to.

[0088] In the curable resin composition for a lens of the present invention, when containing a polymer dispersant and the above metal oxide T, the content of the polymer dispersant with respect to 100 parts by mass of the content of the metal oxide T is preferably 1 to 50 parts by mass, more preferably 3 to 30 parts by mass, and even more preferably 4 to 30 parts by mass. By setting the content ratio within the above preferred range, it is possible to stably disperse the metal oxide T such as ITO particles in the curable resin composition for a lens and suppress the incorporation of bubbles generated during curing.

[0089] [Polymerization initiator] The curable resin composition for a lens of the present invention preferably contains at least one of a thermal radical polymerization initiator and a photo radical polymerization initiator as a polymerization initiator.

[0090] (Thermal radical polymerization initiator) The curable resin composition for a lens of the present invention preferably contains a thermal radical polymerization initiator. By thermally polymerizing the curable resin composition for a lens of the present invention by the action of this thermal radical polymerization initiator, a cured product having high heat resistance can be obtained.

[0091] As the thermal radical polymerization initiator, a compound usually used as a thermal radical polymerization initiator can be appropriately used according to the conditions of the subsequent thermal polymerization (thermal curing) step. For example, organic peroxides and the like can be mentioned, and specifically, the following compounds can be used. For example, 1,1-di(t-hexylperoxy)cyclohexane, 1,1-di(t-butylperoxy)cyclohexane, 2,2-di(4,4-di-(t-butylperoxy)cyclohexyl)propane, t-hexylperoxyisopropyl monocarbonate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, dicumyl peroxide, di-t-butyl peroxide, t-butylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, cumene hydroperoxide, t-butyl hydroperoxide, t-butylperoxy-2-ethylhexyl, 2,3-dimethyl-2,3-diphenylbutane, etc. can be mentioned.

[0092] When containing a thermal radical polymerization initiator, the content of the thermal radical polymerization initiator in the curable resin composition for lenses of the present invention is preferably 0.01 to 10% by mass, more preferably 0.05 to 5.0% by mass, and even more preferably 0.05 to 2.0% by mass.

[0093] (Photo radical polymerization initiator) The curable resin composition for lenses of the present invention preferably contains a photo radical polymerization initiator. As the photo radical polymerization initiator, compounds usually used as photo radical polymerization initiators can be appropriately used according to the conditions of the photopolymerization (photocuring) process described later, and specifically, the following compounds can be used. For example, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,6-dimethylbenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,6-dichlorobenzoyl)-2,4,4-trimethylpentylphosphine oxide, 1-phenyl-2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 1,2-diphenylethanedione, methyl phenyl glyoxylate, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, etc. can be mentioned.

[0094] Among them, in the present invention, as the photo radical polymerization initiator, 1-hydroxycyclohexyl phenyl ketone (available, for example, as Irgacure 184 (trade name) manufactured by BASF), bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (available, for example, as Irgacure 819 (trade name) manufactured by BASF), 2,2-dimethoxy-1,2-diphenylethane-1-one (available, for example, as Irgacure 651 (trade name) manufactured by BASF), 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one or 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one can be preferably used.

[0095] When containing a photo radical polymerization initiator, the content of the photo radical polymerization initiator in the curable resin composition for lenses of the present invention is preferably 0.01 to 5.0% by mass, more preferably 0.05 to 1.0% by mass, and even more preferably 0.05 to 0.5% by mass. In addition, the curable resin composition for lenses of the present invention may contain both a photo radical polymerization initiator and a thermal radical polymerization initiator. In this case, the total content of the photo radical polymerization initiator and the thermal radical polymerization initiator in the curable resin composition for lenses of the present invention is preferably 0.01 to 5% by mass, more preferably 0.05 to 1.0% by mass, and even more preferably 0.05 to 0.5% by mass.

[0096] [Polymer having a radical polymerizable group in the side chain] The curable resin composition for lenses of the present invention may contain a polymer having a radical polymerizable group in the side chain. As the polymer having a radical polymerizable group in the side chain, for example, the description of the polymer having a radical polymerizable group in the side chain in

[0088] to

[0095] of International Publication No. 2019 / 044863 can be preferably applied.

[0097] (Other additives, etc.) Unless contrary to the gist of the present invention, the curable resin composition for lenses of the present invention may contain additives such as polymers or monomers, dispersants, plasticizers, heat stabilizers, and release agents other than the above-described components.

[0098] [Cured product] The cured product of the present invention is obtained from the curable resin composition for lenses of the present invention. The cured product is obtained by polymerizing a polymerizable compound (such as a dye A having a polymerizable group, a (meth)acrylate monomer, etc.), but the cured product of the present invention may contain unreacted monomers. The cured product obtained by curing the curable resin composition for lenses of the present invention has high transmittance in the wavelength range of NIR to SWIR, and the wavelength dispersion WD calculated by the above formula (X) is 2.0×10 -5It is as described above and exhibits high wavelength dispersibility, and the refractive index at a wavelength of 656 nm and the refractive index at a wavelength of 1129 nm are both low as described later.

[0099] For example, when the cured product is formed as a sheet with a thickness of 6 μm, a value of 88% or more can be obtained as the transmittance at a wavelength of 1100 nm, and a value of 30% or more can be obtained as the transmittance at a wavelength of 1500 nm, preferably 40% or more, more preferably 50% or more. Here, the transmittance means the value measured with a spectrophotometer (for example, the spectrophotometer "UV-3100 (trade name)" manufactured by Shimadzu Corporation).

[0100] The refractive index nC at a wavelength of 656 nm of the cured product obtained by curing the curable resin composition for lenses of the present invention is preferably 1.45 to 1.65, more preferably 1.47 to 1.62. The refractive index at a wavelength of 1129 nm of the cured product obtained by curing the curable resin composition for lenses of the present invention is preferably 1.42 to 1.63, more preferably 1.45 to 1.60. Note that the refractive index of the cured product is a value specific to the substance that does not depend on the film thickness, and can be measured, for example, by the method described in the examples below.

[0101] [Manufacturing method of cured product] The cured product of the present invention can be manufactured by a method including at least one of a step of photocuring the curable resin composition for lenses of the present invention and a step of thermocuring. When photocuring, it is preferable to contain the above-mentioned photo radical polymerization initiator, and when thermocuring, it is preferable to contain the above-mentioned thermal radical polymerization initiator in the curable resin composition, respectively. As a manufacturing method of the cured product, it is also preferable to include a step of forming a semi-cured product by irradiating the curable resin composition for lenses with light or heating the curable resin composition for lenses, and a step of forming a cured product by irradiating the obtained semi-cured product with light or heating the semi-cured product.

[0102] For the "step of forming a semi-cured product", "step of forming a cured product", and "semi-cured product", the descriptions of the "step of forming a semi-cured product", "step of forming a cured product", and "semi-cured product" in

[0106] to

[0117] ,

[0118] to

[0124] , and

[0125] of International Publication No. 2019 / 044863 can be directly applied as they are.

[0103] <<Use of the curable resin composition for lenses>> The curable resin composition for lenses of the present invention is a curable resin composition for lenses. Specifically, it is suitable for lens applications such as camera lenses for surveillance cameras, etc., short-wave infrared imaging lenses for electronic substrate inspection and solar cell inspection, etc., and lenses where wavelength dispersion in the wavelength range of NIR to SWIR such as in multi-wavelength spectroscopic cameras is required. Among them, it is preferably used as a material for manufacturing diffractive optical elements, and is used as a material for manufacturing diffractive optical elements with low refractive index and high wavelength dispersion in the multi-layer diffractive optical elements described later, and can provide excellent diffraction efficiency.

[0104] <Diffractive optical element> The diffractive optical element of the present invention is a diffractive optical element including a surface having a diffractive grating shape formed of the cured product of the present invention, and is formed by curing the curable resin composition for lenses of the present invention. The diffractive optical element formed by curing the curable resin composition for lenses of the present invention preferably has a maximum thickness of 2 μm to 100 μm. The maximum thickness is more preferably 2 μm to 50 μm, and particularly preferably 2 μm to 30 μm. Also, the step (grating thickness) of the diffractive grating shape (periodic structure) of the diffractive optical element is preferably 1 μm to 100 μm, and more preferably 1 μm to 50 μm. Furthermore, the pitch of the diffractive grating shape of the diffractive optical element may be between 0.1 mm and 10 mm, and it is preferably changed within the same diffractive optical element according to the required optical aberration.

[0105] The diffractive optical element can be manufactured, for example, by the following procedure. The curable resin composition for a lens of the present invention is sandwiched between the above surface of a mold having a surface processed into a diffraction grating shape and a transparent substrate. After that, the curable resin composition for a lens of the present invention may be pressurized and stretched to a desired extent. While being sandwiched, light is irradiated from the transparent substrate side to cure the curable resin composition for a lens of the present invention. Then, the cured product is released from the mold. After release, light may be further irradiated from the side opposite to the transparent substrate side.

[0106] Examples of the above transparent substrate include flat glass and flat transparent resins ((meth)acrylic resin, polycarbonate resin, polyethylene terephthalate, etc.). The transparent substrate used in the above production may be included in the diffractive optical element as it is, or may be peeled off.

[0107] The surface of the mold processed into a diffraction grating shape is preferably subjected to a chromium nitride treatment. Thereby, good mold releasability can be obtained, and the production efficiency of the diffractive optical element can be enhanced. Examples of the chromium nitride treatment include a method of forming a chromium nitride film on the mold surface. Examples of the method of forming a chromium nitride film on the mold surface include a CVD (Chemical Vapor Deposition) method and a PVD (Physical Vapor Deposition) method. The CVD method is a method of forming a chromium nitride film on the substrate surface by reacting a raw material gas containing chromium and a raw material gas containing nitrogen at a high temperature. The PVD method is a method of forming a chromium nitride film on the substrate surface using arc discharge (arc type vacuum evaporation method). This arc type vacuum evaporation method arranges, for example, a cathode (evaporation source) made of chromium in a vacuum chamber, causes an arc discharge between the cathode and the wall surface of the vacuum chamber via a trigger, evaporates the cathode, and at the same time attempts to ionize the metal by the arc plasma, applies a negative voltage to the substrate, and introduces a reaction gas (for example, nitrogen gas) into the vacuum chamber at about several 10 mTorr (1.33 Pa), and reacts the ionized metal and the reaction gas on the surface of the substrate to form a compound film.

[0108] The light used for light irradiation for curing the curable resin composition for lenses of the present invention is preferably ultraviolet light or visible light, and more preferably ultraviolet light. For example, metal halide lamps, low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, germicidal lamps, xenon lamps, LED (Light Emitting Diode) light source lamps, etc. are preferably used. The illuminance of the ultraviolet light used for light irradiation for curing the curable resin composition for lenses of the present invention is preferably 1 to 100 mW / cm 2 and more preferably 1 to 75 mW / cm 2 and even more preferably 5 to 50 mW / cm 2 Ultraviolet light with different illuminances may be irradiated multiple times. The exposure amount of ultraviolet light is preferably 0.4 to 10 J / cm 2 and more preferably 0.5 to 5 J / cm 2 and even more preferably 1 to 3 J / cm 2 The atmosphere during light irradiation is preferably air or an inert gas-substituted atmosphere, and more preferably an atmosphere in which air is replaced with nitrogen until the oxygen concentration becomes 1% or less.

[0109] <Multilayer diffractive optical element> The multilayer diffractive optical element of the present invention includes a first diffractive optical element and a second diffractive optical element, the first diffractive optical element being a diffractive optical element formed of a cured product of the present invention, and a surface having a diffraction grating shape of the first diffractive optical element and a surface having a diffraction grating shape of the second diffractive optical element facing each other. The surfaces having the diffraction grating shapes of each other are preferably in contact. It is preferable to use a diffractive optical element formed by curing the curable resin composition for lenses of the present invention as the first diffractive optical element, and further stack a second diffractive optical element formed of a different material so that the surfaces of the grating shapes face each other to form a multilayer diffractive optical element. At this time, the surfaces of the grating shapes of each other are preferably in contact. By forming the second diffractive optical element with a material having a higher refractive index and lower wavelength dispersion than the first diffractive optical element, the occurrence of flare and the like can be suppressed, and the chromatic aberration reduction effect of the multilayer diffractive optical element can be fully utilized.

[0110] The refractive index of the second diffractive optical element at a wavelength of 656 nm is preferably 1.55 to 1.70, more preferably 1.58 to 1.68. Further, the refractive index of the second diffractive optical element at a wavelength of 656 nm is greater than the refractive index of the first diffractive optical element that is used simultaneously in the multilayer diffractive optical element. That is, it satisfies the refractive index of the second diffractive optical element at a wavelength of 656 nm > the refractive index of the first diffractive optical element at a wavelength of 656 nm. The refractive index of the second diffractive optical element at a wavelength of 1129 nm is preferably 1.55 to 1.70, more preferably 1.58 to 1.68. Further, the refractive index of the second diffractive optical element at a wavelength of 1129 nm is greater than the refractive index of the first diffractive optical element that is used simultaneously in the multilayer diffractive optical element. That is, it satisfies the refractive index of the second diffractive optical element at a wavelength of 1129 nm > the refractive index of the first diffractive optical element at a wavelength of 1129 nm.

[0111] The material for forming the second diffractive optical element is not particularly limited as long as a cured product having a high refractive index and low wavelength dispersibility can be obtained. For example, a curable resin composition for a lens containing a (meth)acrylate monomer compound having a sulfur atom, a halogen atom, or an aromatic ring structure, or a curable resin composition for a lens containing zirconium oxide and a (meth)acrylate monomer compound can be used.

[0112] The multilayer diffractive optical element can be manufactured, for example, by the following procedure. A material for forming the second diffractive optical element is sandwiched between the diffractive grating-shaped surface (the surface obtained after the above-mentioned mold release) of the diffractive optical element formed by curing the curable resin composition for a lens of the present invention and the transparent substrate. Thereafter, the material may be pressed and stretched to a desired range. While in the sandwiched state, light is irradiated from the transparent substrate side to cure the above-mentioned material. Thereafter, the cured product is released from the mold. That is, as the multilayer diffractive optical element of the present invention, it is preferable that the first diffractive optical element, the second diffractive optical element, and the transparent substrate are arranged in this order.

[0113] Examples similar to the transparent substrate used in the production of the above-mentioned diffractive optical element (first diffractive optical element) can be cited as the above-mentioned transparent substrate. The transparent substrate used in the above production may be included in the multilayer diffractive optical element as it is, or may be peeled off.

[0114] It is preferable that the diffraction efficiency of the multilayer diffractive optical element is high. For example, the diffraction efficiency of the first-order light at a wavelength of 656 nm of the multilayer diffractive optical element is preferably 50% or more, more preferably 80% or more, even more preferably 85% or more, and particularly preferably 95% or more. Also, the diffraction efficiency of the first-order light at a wavelength of 1129 nm of the multilayer diffractive optical element is preferably 90% or more, and more preferably 95% or more. Since the diffraction efficiency of the first-order light of the multilayer diffractive optical element shows a high diffraction efficiency at the above wavelengths of 656 nm and 1129 nm, unnecessary diffracted light can be sufficiently suppressed, and a high-performance lens can be realized.

[0115] The multilayer diffractive optical element preferably has a maximum thickness of 50 μm to 20 mm. The maximum thickness is more preferably 50 μm to 10 mm, and particularly preferably 50 μm to 3 mm.

[0116] <Lens> The above diffractive optical element and multilayer diffractive optical element can each be used as a lens. A film or member can be provided on the surface or around the lens according to the usage environment and application of the lens. For example, a protective film, an antireflection film, a hard coat film, etc. can be formed on the surface of the lens. Also, it can be made into a composite lens laminated on a glass lens or a plastic lens. Furthermore, the periphery of the lens can also be fitted and fixed into a substrate holding frame or the like. However, these films or frames, etc. are members added to the lens and are distinguished from the lens itself referred to in this specification.

[0117] The lens is preferably used for imaging lenses such as mobile phones and digital cameras, shooting lenses such as televisions and video cameras, and in-vehicle lenses.

Examples

[0118] The present invention will be described in more detail based on the following examples. The materials, amounts used, ratios, processing contents, processing procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

[0119] [Synthesis Example]

[0120] [1. Synthesis of ITO Particles] (1) Synthesis of ITO Particles (ITO-1) 75 ml of oleic acid (manufactured by Sigma-Aldrich, technical grade, 90%), 10.060 g (34.5 mmol) of indium acetate (manufactured by Alfa Aesar, 99.99%), and 1.079 g (3.0 mmol) of tin(IV) acetate (manufactured by Alfa Aesar) were introduced into a flask. The mixture in this flask was heated at 160 °C for 1 hour in an environment of nitrogen flow to obtain a yellow transparent precursor solution.

[0121] Subsequently, 90 ml of oleyl alcohol (manufactured by Fujifilm Wako Pure Chemical Corporation (formerly Wako Chemicals), standard content: 65% or more) in another flask was heated to 290 °C in a nitrogen flow. The above precursor solution was dropped into the heated oleyl alcohol at a rate of 1.75 ml / min using a syringe pump. After the dropping of the above precursor solution was completed, the obtained reaction solution was held at 290 °C for 120 minutes, and then the heating was stopped and cooled to room temperature.

[0122] After adding ethanol to the obtained reaction solution, centrifugation was performed to precipitate the particles. The supernatant was removed, and redispersion in toluene was repeated three times to obtain a toluene dispersion of ITO particles (ITO-1) with oleic acid coordination. The solid content concentration in the dispersion was 5% by mass in total, consisting of 4.75% by mass of ITO solid content and 0.25% by mass of the solid content of the surface treatment component. When the above ITO particles (ITO-1) were observed by TEM (product name: JFM-ARM300F2 GRAND, manufactured by JEOL Ltd.), the average primary particle size was 28.5 nm. Specifically, it was measured based on the measurement method of the average primary particle size of the aforementioned ITO particles. The above toluene dispersion was diluted 200-fold with toluene, and spectroscopic measurement was performed using UV-3100 (product name, manufactured by Shimadzu Corporation). As a result, the maximum absorption wavelength was 1750 nm.

[0123] (2) Synthesis of ITO particles (ITO-2) 75 ml of oleic acid (manufactured by Sigma-Aldrich, technical grade, 90%), 10.62 g (36.4 mmol) of indium acetate (manufactured by Alfa Aesar, 99.99%), and 0.400 g (1.1 mmol) of tin(IV) acetate (manufactured by Alfa Aesar) were placed in a flask. The mixture in this flask was heated at 160 °C for 1 hour in an environment of nitrogen flow to obtain a yellow transparent precursor solution.

[0124] Subsequently, 90 ml of oleyl alcohol (manufactured by Fujifilm Wako Pure Chemical Corporation, standard content: 65% or more) in another flask was heated to 285 °C in a nitrogen flow. The above precursor solution was dropped into the heated oleyl alcohol at a rate of 0.70 ml / min using a syringe pump. After the dropping of the above precursor solution was completed, the obtained reaction solution was held at 285 °C for 30 minutes, and then the heating was stopped and cooled to room temperature.

[0125] After adding ethanol to the obtained reaction solution, centrifugation was performed to precipitate the particles. The supernatant was removed, and redispersion in toluene was repeated three times to obtain a toluene dispersion of ITO particles (ITO-2) coordinated with oleic acid. The solid content concentration in the dispersion was 5% by mass in total, which was the sum of 4.75% by mass of ITO solid content and 0.25% by mass of the solid content of the surface treatment component. When the above ITO particles (ITO-2) were observed by TEM (product name: JFM-ARM300F2 GRAND, manufactured by JEOL Ltd.), the average primary particle size was 25 nm. Specifically, it was measured based on the measurement method of the average primary particle size of the aforementioned ITO particles. The above toluene dispersion was diluted 200-fold with toluene, and UV-3100 (product name, manufactured by Shimadzu Corporation) spectroscopic measurement was performed. As a result, the maximum absorption wavelength was 2350 nm.

[0126] [2. Synthesis of Polymer Dispersant] (Polymer Dispersant (P-1)) 10.8 g of benzyl methacrylate (manufactured by Fujifilm Wako Pure Chemical Corporation), 9.2 g of t-butyl methacrylate (manufactured by Fujifilm Wako Pure Chemical Corporation), and 0.95 g of mercaptosuccinic acid (manufactured by Fujifilm Wako Pure Chemical Corporation) were dissolved in 23 mL of methyl ethyl ketone and heated to 70 °C under a nitrogen stream. To this solution, a solution prepared by dissolving 0.20 g of a polymerization initiator (product name: V-65, manufactured by Fujifilm Wako Pure Chemical Corporation) in 9 mL of methyl ethyl ketone was added dropwise over 30 minutes. After completion of the dropwise addition, the reaction was further carried out at 70 °C for 4.5 hours. After allowing to cool, the reaction solution was added dropwise to a mixed solution of 200 mL of cooled water and 600 mL of methanol, and the precipitated powder was collected by filtration and dried to obtain 17 g of a polymer dispersant (P-1) having a carboxy group as an acidic group at one end. This polymer dispersant (P-1) is substantially composed of a polymer having a carboxy group at one end. The weight-average molecular weight (Mw) of the obtained polymer was 5,900 in terms of standard polystyrene by the GPC (Gel Permeation Chromatography) method measured under the following measurement conditions, and the dispersity (Mw / Mn, Mn: number-average molecular weight) was 1.70. Also, when the acid value was determined by measuring the number of mg of potassium hydroxide required to neutralize the free fatty acids present in 1 g of the obtained polymer, it was 20 mgKOH / g. (Measurement conditions) Measuring instrument: HLC-8320GPC (trade name, manufactured by Tosoh Corporation) Column: Connect TOSOH TSKgel SuperHZM-H (trade name, manufactured by Tosoh Corporation), TOSOH TSKgel SuperHZ4000 (trade name, manufactured by Tosoh Corporation), and TOSOH TSKgel SuperHZ2000 (trade name, manufactured by Tosoh Corporation). Carrier: THF Measurement temperature: 40 °C Carrier flow rate: 0.35 mL / min Sample concentration: 0.1% Detector: RI (refractive index) detector

[0127] [Chemical formula]

[0128] [Examples] [1. Preparation of curable resin composition for lenses] (1) Preparation of curable resin compositions for lenses No. 101 to 106, 108 to 111, c02 and c03 Dyes, monomer components, and photoinitiators were mixed so as to have the compositions described in the following table, and stirred to make them uniform, thereby preparing curable compositions for lenses No. 101 to 106, 108 to 111, c02 and c03. (2) Preparation of curable resin composition for lenses No. 107 To 5.2 g of a toluene dispersion of ITO-2 (solid content: 0.26 g), 0.075 g of the tetrathiaporphyrin dye TAP-1 described below, 0.052 g of a polymer dispersant (P-1), and 0.609 g of 1,6-hexanediol dimethacrylate (hereinafter abbreviated as "HDDMA", manufactured by Fujifilm Wako Pure Chemical Corporation) were added and dissolved. While heating in a water bath at about 70 °C, toluene was distilled off under reduced pressure by suction. To the mixture obtained after distillation, 0.004 g of IRGACURE 819 (trade name, manufactured by BASF) was added and dissolved to prepare a curable resin composition No. 107 for lenses. (3) Preparation of curable resin composition No. c01 for lenses To 5.2 g of a toluene dispersion of ITO-1 (solid content: 0.26 g), 0.30 g of the near-ultraviolet light-absorbing organic compound I-1 described below, 0.052 g of a polymer dispersant (P-1), and 0.384 g of HDDMA (manufactured by Fujifilm Wako Pure Chemical Corporation) were added and dissolved. While heating in a water bath at about 70 °C, toluene was distilled off under reduced pressure by suction. To the mixture obtained after distillation, 0.004 g of IRGACURE 819 (trade name, manufactured by BASF) was added and dissolved to prepare a curable resin composition No. c01 for lenses.

[0129] [Evaluation 1: Measurement of optical properties] (1) Preparation of cured product 15 mg of the curable resin composition for lenses prepared above was placed on a mirror-finished SUS plate, sandwiched between hydrophobized glass plates, and irradiated with UV using a UV irradiation device (EXECURE 3000 (trade name), manufactured by HOYA CANDEO OPTRONICS) under the conditions of an integrated light amount of 1.0 J / cm 2 and an illuminance of 30 mW / cm 2 . After UV irradiation, it was irradiated with UV under the conditions of an integrated light amount of 1.0 J / cm 2 and an illuminance of 5 mW / cm 2 to prepare a cured product. The film thickness of the cured product obtained as described above was 10 to 20 μm.

[0130] (2) Measurement of refractive index and WD Using the cured product prepared under the above conditions, the refractive indices at wavelengths of 656 nm and 1129 nm were measured with a multi-wavelength Abbe refractometer DR-M2 (trade name, manufactured by Atago Co., Ltd.), the wavelength dispersion WD was calculated by the following formula (X), and evaluated according to the following criteria. In this test, the evaluation ranks "A1" to "C" are the passing levels. WD = (nC - n(1129)) / (1129 - 656) Formula (X) In the above formula, nC represents the refractive index at a wavelength of 656 nm, and n(1129) represents the refractive index at a wavelength of 1129 nm. For all the cured products prepared under the above conditions, the refractive index nC at a wavelength of 656 was 1.47 to 1.60. - Evaluation Criteria for Wavelength Dispersion WD - A1: 7.0×10 -5 or more. A2: 5.0×10 -5 or more and less than 7.0×10 -5 was satisfied. B: 3.0×10 -5 or more and less than 5.0×10 -5 was satisfied. C: 2.0×10 -5 or more and less than 3.0×10 -5 was satisfied. D: less than 2.0×10 -5 was satisfied. E: Evaluation could not be performed due to coloring of the cured product.

[0131] 〔Evaluation 2: Light Resistance Test〕 (1) Preparation of Cured Product Sample for Light Resistance Test 0.8 μL of the curable resin composition for lenses prepared above was placed on a glass plate of 2.5 cm × 2.5 cm, sandwiched with a glass plate of the same size so that no air bubbles were mixed in, and the curable composition was spread over the entire surface of the glass plate. At this time, the thickness was adjusted so that the absorbance Abs1 measured in the following (2) was 1.7 to 2.0. In an atmosphere with an oxygen concentration of 1% or less, using EXECURE3000 (trade name, manufactured by HOYA) as a UV irradiation device, 2 J / cm 2By irradiating with ultraviolet rays, a cured product (cured product sample for light resistance test) sanded on a glass plate was obtained.

[0132] (2) Absorbance measurement and light resistance test For the cured product sample prepared above, using a spectrophotometer UV-2600 (trade name, manufactured by Shimadzu Corporation), the absorbance in the wavelength range of 200 to 800 nm was measured every 1 nm, and the absorbance Abs1 at λmax was obtained. Then, using a xenon accelerated weathering tester Q-SUN Xe-1 (trade name, manufactured by Q-Lab Corporation, light source: xenon arc lamp), after irradiating for 24 hours under the condition of illuminance 0.4 W / m 2 (340 nm), the absorbance was measured in the same manner as above, and the absorbance Abs2 at λmax was measured. In the above, λmax means the wavelength showing the largest absorbance among the wavelengths showing maximum absorption, and λmax in the following table has the same meaning. The decrease rate (ΔAbs) of the absorbance before and after the light irradiation test was calculated according to the following formula, and the light resistance was evaluated based on the following criteria. In this test, the evaluation ranks "A1" to "C" are considered qualified. ΔAbs = (Abs1 - Abs2) / Abs1 × 100 - Light resistance evaluation - A1: The decrease rate (ΔAbs) of the absorbance was less than 10%. A2: The decrease rate (ΔAbs) of the absorbance was 10% or more and less than 15%. B1: The decrease rate (ΔAbs) of the absorbance was 15% or more and less than 20%. B2: The decrease rate (ΔAbs) of the absorbance was 20% or more and less than 25%. C: The decrease rate (ΔAbs) of the absorbance was 25% or more and less than 30%. D: The decrease rate (ΔAbs) of the absorbance was 30% or more and less than 40%. E: The decrease rate (ΔAbs) of the absorbance was 40% or more.

[0133]

Table 1-1

[0134]

Table 1-2

[0135] Each component in the table is as follows. Note that the description of "-" in each component means that the corresponding component is not contained. Also, "wt%" means mass%, and the blending amount of ITO particles means the amount of solid content in the ITO particle dispersion.

[0136] (Dye) FDG-003: Trade name, manufactured by Yamada Chemical Industry Co., Ltd., merocyanine dye TAP-1 and TAP-2: They are the tetraazaporphyrin dyes TAP-1 and TAP-2 described below, respectively. TAP-1 was synthesized by the method described in Examples 4 and 10 of JP-A-2012-121821, and TAP-2 was synthesized in the same manner as in Examples 4 and 10 of JP-A-2012-121821, except that cuprous chloride was changed to palladium chloride. I-1: It is the near-ultraviolet light-absorbing organic compound I-1 described below. The near-ultraviolet light-absorbing organic compound I-1 was synthesized in the same manner as in <Synthesis of Compound (I-4)> described in the examples of International Publication No. 2020 / 171197, except that 2-hydroxyethyl acrylate was used instead of compound (I-4a).

Chemical formula

[0137] (Monomer component) FA-513AS: Trade name, manufactured by Showa Denko Materials Co., Ltd. The Tg noted together in the following structure is the Tg of the corresponding homopolymer measured by the aforementioned method.

Chemical formula

[0138] (Metal oxide) ITO-1 and ITO-2: They are toluene dispersions of ITO-1 and ITO-2 prepared above, respectively. (Polymer dispersant) P-1: The polymer dispersant (P-1) prepared above (Photoinitiator) Irgacure819: Trade name, manufactured by BASF [Chemical formula]

[0139] From the results in Table 1, the following can be understood. The curable resin compositions No. c01 and c02 for comparison lenses do not contain a dye having a maximum absorption at wavelengths of 520 to 620 nm, and thus are not the curable resin compositions for lenses of the present invention. The cured product obtained from this comparative curable resin composition No. c01 for lenses is a cured product imitating the cured product described in Prior Art Document 1. The wavelength dispersion WD calculated from formula (X) cannot be evaluated for the cured product obtained from this comparative curable resin composition No. c01 for lenses, and it was inferior in both wavelength dispersion characteristics and light resistance in the wavelength range of NIR to SWIR. Also, even for the comparative curable resin composition No. c02 for lenses adjusted so as not to contain ITO with respect to the comparative curable resin composition No. c01 for lenses, still, the wavelength dispersion WD calculated from formula (X) was less than 2.0×10 -5 and it was inferior in both wavelength dispersion WD and light resistance. Also, even when the dye concentration was adjusted to be higher with respect to the comparative curable resin composition No. c02 for lenses, the wavelength dispersion WD was not improved to a level of 2.0×10 -5 or higher. In contrast, the curable resin compositions No. 101 to 111 for lenses of the present invention containing the polymer dispersant defined in the present invention have a cured product with a wavelength dispersion WD calculated from formula (X) of 2.0×10 -5It was at the above level, excellent in wavelength dispersion characteristics in the wavelength range of NIR to SWIR, and also exhibited excellent light resistance. From the comparison between the cured products obtained from the curable resin compositions No. 104, 108 to 110 for lenses of the present invention and the cured product obtained from the curable resin composition No. c03 for lenses, it can be seen that by appropriately adjusting the content of the dye having a maximum absorption at a wavelength of 520 to 620 nm, the wavelength dispersion characteristics in the wavelength range of NIR to SWIR can be adjusted. Among them, when containing a tetraazaporphyrin dye as the dye having a maximum absorption at a wavelength of 520 to 620 nm, it can be seen that the wavelength dispersion WD calculated from the formula (X) is improved (No. 101 compared to No. 102). Further, when using a curable resin composition for lenses containing a tetraazaporphyrin dye as the dye having a maximum absorption at a wavelength of 520 to 620 nm and, as a component constituting the resin in the cured product, a bifunctional or higher (meth)acrylate monomer or a monofunctional (meth)acrylate monomer having a Tg of 100 °C or higher of a homopolymer in combination, it was found that the light resistance was improved (comparison between No. 111 and No. 101, and between No. 103 to 105 and No. 102). Also, when using ITO in combination, it was found that excellent wavelength dispersion characteristics in the wavelength range of NIR to SWIR can be exhibited while keeping the dye concentration having a maximum absorption at a wavelength of 520 to 620 nm low (see No. 107 and 108).

[0140] 〔Evaluation 3: Measurement of Transmittance〕 (1) Preparation of Cured Product Sample for Transmittance Measurement The curable resin composition for lenses prepared above was sandwiched between hydrophobically treated glass plates so as not to mix air bubbles, and using a UV irradiation device (EXECURE 3000 (trade name), manufactured by HOYA CANDEO OPTRONICS Co., Ltd.), the integrated light quantity was 1.0 J / cm 2 , and the illuminance was 30 mW / cm 2 . After UV irradiation under these conditions, the integrated light quantity was 1.0 J / cm 2 , and the illuminance was 5 mW / cm 2Under the above conditions, UV irradiation was performed to prepare a cured product (cured product sample for transmittance measurement). The film thickness of the cured product obtained as described above was 6 μm.

[0141] (2) Measurement of transmittance For the cured product sample prepared under the above conditions, the transmittance at wavelengths of 200 to 2100 nm was measured using a spectrophotometer UV-3100 (trade name, manufactured by Shimadzu Corporation). Among the curable resin compositions for lenses, the transmittances at 1100 nm and 1500 nm for No.107 and c01 containing ITO are summarized in Table 2 below.

[0142]

Table 2

[0143] The cured product obtained from the comparative curable resin composition for lenses No. c01 had low transmittances at both 1100 nm and 1500 nm and was inferior. In contrast, the cured product obtained from the curable resin composition for lenses No.107 of the present invention had high transmittances at both 1100 nm and 1500 nm and satisfied the transmittance characteristics required for a lens applied in the wavelength range of NIR to SWIR. The cured products obtained from the curable resin compositions for lenses No.101 to 106 and 108 to 111 of the present invention showed the transmittances derived from the resin components constituting the cured products, and all showed higher transmittances than the cured product obtained from the curable resin composition for lenses No.107 of the present invention, and satisfied the transmittance characteristics required for a lens applied in the wavelength range of NIR to SWIR.

Claims

1. A curable resin composition for a lens, the composition containing a dye A having a maximum absorption at a wavelength of 520 to 620 nm, and the wavelength dispersion WD calculated by the following formula (X) of the cured product of the composition being 2.0×10 －５ or more, A curable resin composition for a lens, wherein the content of the dye A in the composition is 15% by mass or more, or the composition contains a metal oxide having a maximum absorption at a wavelength of 1900 to 4000 nm. WD = (nC - n(1129)) / (1129 - 656) Formula (X) In the above formula, nC represents the refractive index at a wavelength of 656 nm, and n(1129) represents the refractive index at a wavelength of 1129 nm.

2. The curable resin composition for a lens according to claim 1, wherein the dye A is a tetraazaporphyrin dye.

3. The curable resin composition for a lens according to claim 2, wherein the dye A is a compound represented by the following general formula (α). 【Chemical 1】 In the above formula, M represents Pd, Cu, Ni, Co, V(=O). Z １ to Z ８ is Z １ and Z ２ 、Z ３ and Z ４ 、Z ５ and Z ６ 、and Z ７ and Z ８ In each combination of Z and Z, one group constituting the combination is a substituted phenyl group, and the other group is a hydrocarbon group having 1 to 6 carbon atoms.

4. The curable resin composition for a lens according to any one of claims 1 to 3, which contains at least one of a polyfunctional (meth)acrylate monomer and a monofunctional (meth)acrylate monomer, and the glass transition temperature of the monofunctional (meth)acrylate monomer as a homopolymer is 100°C or higher.

5. A cured product of the curable resin composition for a lens according to any one of claims 1 to 4.

6. A diffractive optical element including the cured product according to claim 5 and having a surface formed in a diffractive grating shape by the cured product.

7. A multilayer diffractive optical element including a first diffractive optical element and a second diffractive optical element, wherein the first diffractive optical element is the diffractive optical element according to claim 6, and the surface having the diffractive grating shape in the first diffractive optical element faces the surface having the diffractive grating shape in the second diffractive optical element.

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