Cured products, optical elements, optical equipment, imaging devices

Abstract

To provide an optical material which has high transmittance and high secondary dispersion characteristics.SOLUTION: A cured product is a cured product of a resin composition, and the resin composition contains a compound represented by the general formula (1). R1-R4 are selected from a polymerizable functional group, a substituted or unsubstituted 1-8C alkyl group, a substituted or unsubstituted 1-6C alkyl group having a polymerizable functional group at a terminal thereof, a substituted or unsubstituted 2-6C alkyl group having a polymerizable functional group at a terminal thereof and one of CH2 in the main chain substituted by O or S. R5-R9 are independently selected from H and CF3. However, at least one of R1-R4 is a polymerizable functional group or a substituent group having a polymerizable functional group, and at least one of R5-R9 has CF3.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a cured product for optical elements, an optical element using the cured product, and an optical instrument and an imaging device using the optical element. [Background technology]

[0002] In general, optical materials such as glass materials and organic resins have a gradually increasing refractive index toward the shorter wavelength side. The Abbe number (ν d ) and second-order dispersion characteristics (θ g,F ) are known. The Abbe number and secondary dispersion characteristics are values ​​specific to each optical material, but in most cases they fall within a certain range. d Abbe number based on the d line) and second-order dispersion characteristics (θ g,F ) is expressed by the following formula: ν d =(n d -1) / (n F -n C ) θ g,F =(n g -n F ) / (n F -n C ) n d : Refractive index at wavelength 587.6 nm n F : Refractive index at wavelength 486.1 nm n C : Refractive index at wavelength 656.3 nm n g : Refractive index at wavelength 435.8 nm However, by carefully designing the composition (material type and molecular structure) of optical materials (glass materials, organic resins, etc.), optical materials with high second-order dispersion characteristics outside of this certain range of values ​​have also been synthesized. Furthermore, when manufacturing optical elements having aspherical shapes or the like that offer excellent chromatic aberration correction capabilities, molding an organic resin onto a spherical glass or the like has the advantages of being more suitable for mass production, easier to mold, more flexible in shape, and lighter in weight than using glass material. However, the optical properties of conventional organic resins fall within the aforementioned fixed range, and few exhibit unique dispersion characteristics. Patent Document 1 discloses a cured product of a triarylamine compound in which two benzene rings and a fluorene skeleton are bonded, as an optical material having a high Abbe number and high second-order dispersion characteristics. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-165355 Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention aims to provide an optical material having higher transmittance and secondary dispersion characteristics than the cured product of the triarylamine compound disclosed in Patent Document 1, and an optical element and optical device using the optical material. [Means for solving the problem]

[0005] The present invention relates to a cured product of a resin composition, wherein the resin composition is a compound represented by the following general formula (1): and at least one of an acrylic compound and a methacrylic compound copolymerizable with the compound represented by the general formula (1), in a mass ratio of the acrylic compound and the methacrylic compound to the compound represented by the general formula (1) in the range of 0.01 to 0.30. It is characterized by containing

[0006] [ka] In general formula (1), R1 to R4 are each independently selected from a polymerizable functional group, a substituted or unsubstituted alkyl group having from 1 to 8 carbon atoms, a substituted or unsubstituted alkyl group having from 1 to 6 carbon atoms and having a polymerizable functional group at its terminal, and a group in which one CH2 in the main chain of a substituted or unsubstituted alkyl group having from 2 to 6 carbon atoms and having a polymerizable functional group at its terminal is substituted with an oxygen atom or a sulfur atom. R5 to R9 are each independently selected from a hydrogen atom and a trifluoromethyl group. However, at least one of R1 to R4 is a polymerizable functional group or a substituent having a polymerizable functional group, and at least one of R5 to R9 has a trifluoromethyl group. The polymerizable functional group is an acryloyloxy group or a methacryloyloxy group. The present invention further provides an optical element comprising the above-mentioned cured product, and an optical instrument and an imaging device comprising the optical element. [Effects of the Invention]

[0007] According to the present invention, the second-order dispersion characteristic of the refractive index (θ g,F ), i.e., an optical element containing a cured product having a high chromatic aberration correction function and a high transmittance can be provided. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view in the thickness direction schematically illustrating the configuration of an example of an optical element of the present invention. [Figure 2] 1 is a cross-sectional view schematically showing the configuration of an imaging device using an optical element of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] As a result of intensive research, the present inventors have found that a cured product of a resin composition containing a specific triarylamine compound exhibits high secondary dispersion properties and high transmittance. Specifically, the inventors have found that when two of the three aryl groups in the triarylamine compound are fluorenyl groups and the remaining aryl group is a phenyl group substituted with a trifluoromethyl group, both high secondary dispersion properties and high transmittance can be achieved.

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the following embodiments, and appropriate modifications and improvements to the following embodiments based on the common knowledge of those skilled in the art are also included within the scope of the present invention, provided they do not deviate from the spirit of the present invention. Furthermore, in the present invention, a "resin composition containing a compound represented by the following general formula (1)" refers to a composition that becomes a cured product by polymerization (curing) of the compound, and does not necessarily contain a resin component, polymer component, or polymer component before curing, and also includes compositions consisting only of low-molecular-weight components.

[0011] [Compound] The resin composition of the present invention before curing contains a triarylamine compound represented by the following general formula (1).

[0012] [ka]

[0013] In general formula (1), R1 to R4 are each independently selected from a polymerizable functional group, a substituted or unsubstituted alkyl group having from 1 to 8 carbon atoms, a substituted or unsubstituted alkyl group having from 1 to 6 carbon atoms and having a polymerizable functional group at its terminal, and a group in which one CH2 in the main chain of a substituted or unsubstituted alkyl group having from 2 to 6 carbon atoms and having a polymerizable functional group at its terminal is substituted with an oxygen atom or a sulfur atom. R5 to R9 are each independently selected from a hydrogen atom and a trifluoromethyl group. However, at least one of R1 to R4 is a polymerizable functional group or a substituent having a polymerizable functional group, and at least one of R5 to R9 has a trifluoromethyl group.

[0014] In general, compounds with long conjugated structures, such as aromatic compounds, have smaller band gaps than general-purpose materials, resulting in absorption edges in the ultraviolet region closer to the visible light region. As a result, compounds with long conjugated structures have high refractive indices and high second-order dispersion characteristics. However, simply linking aromatic compounds to construct long conjugated structures does not produce practical materials. For example, large aromatic compounds present challenges in terms of synthesis, coloring, reduced transmittance at the short wavelength end of the visible light region, compatibility with other compounds, and crystal precipitation in compositions.

[0015] Therefore, when using them as optical materials, it is necessary to adjust the length of the conjugated structure from the viewpoint of improving transmittance and suppressing crystallinity. However, shortening the conjugated structure of aromatic compounds or widening the intermolecular distance by steric hindrance of the substituents in order to improve transmittance or suppress crystallinity leads to a decrease in the refractive index and secondary dispersion characteristics.

[0016] The inventors consider the triarylamine compound represented by the above general formula (1) according to the present invention as follows. Having two fluorenyl groups in the compound results in high secondary dispersion properties. Introducing a polymerizable functional group into the compound creates steric hindrance, widening the intermolecular distance and suppressing crystallinity compared to a compound without the polymerizable functional group. Introducing a trifluoromethyl group also creates steric hindrance, suppressing crystallinity. Widening the intermolecular distance through steric hindrance also leads to improved transmittance. By keeping the intermolecular distance widened within a narrow range that does not degrade the secondary dispersion properties, high secondary dispersion properties can be maintained, making it possible to achieve both high secondary dispersion properties and high transmittance.

[0017] The triarylamine compound according to the present invention will be described below. R1 to R9 in general formula (1) are as follows.

[0018] Examples of the substituted or unsubstituted alkyl group having 1 to 8 carbon atoms represented by R1 to R4 include, but are not limited to, methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, and 2-ethylhexyl groups. In terms of secondary dispersion properties, alkyl groups having 1 to 6 carbon atoms are preferred, and methyl and ethyl groups are more preferred.

[0019] The substituted or unsubstituted alkyl group having 1 to 6 carbon atoms and having a polymerizable functional group at its terminal, represented by R1 to R4, is a group in which the terminal H of an alkyl group having 1 to 6 carbon atoms is substituted with a polymerizable functional group, and the alkyl group may have a further substituent in addition to the polymerizable functional group. Examples of the alkyl group having 1 to 6 carbon atoms include, but are not limited to, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, etc. From the viewpoint of ease of synthesis, a methyl group, an ethyl group, an n-propyl group, and an n-butyl group are preferred.

[0020] The group represented by R1 to R4, in which one CH2 in the main chain of a substituted or unsubstituted alkyl group having from 2 to 6 carbon atoms and a polymerizable functional group at its terminal is substituted with an oxygen atom or a sulfur atom, is a group in which one CH2 in the main chain of an alkyl group having from 2 to 6 carbon atoms is substituted with an oxygen atom or a sulfur atom, resulting in a skeleton having from 1 to 5 carbon atoms, and the terminal is substituted with a polymerizable functional group. The alkyl group may further have a substituent other than the polymerizable functional group. Examples of the alkyl group include an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an n-pentyl group, and an n-hexyl group. From the viewpoint of ease of synthesis, a group derived by replacing one CH2 in the main chain of the alkyl group with an oxygen atom is more preferred.

[0021] At least one of R1 to R4 is a polymerizable functional group, an alkyl group having the polymerizable functional group, or a group in which CH2 in the main chain of an alkyl group is substituted with an oxygen atom or a sulfur atom. That is, in the compound represented by general formula (1), the polymerizable functional group may be directly bonded to the fluorenyl group or may be bonded to the fluorenyl group via an alkylene group or an alkylene group substituted with an oxygen atom or a sulfur atom.

[0022] Examples of the polymerizable functional group contained in the compound represented by general formula (1) include an active hydrogen group, an unsaturated polymerizable group, and an epoxy group. Examples of the active hydrogen group include a hydroxyl group, a carboxyl group, an amino group, a thiol group, and a methoxy group, and preferably a hydroxyl group. Examples of the unsaturated polymerizable group include a vinyl group, an acryloyloxy group, and a methacryloyloxy group, and preferably an acryloyloxy group and a methacryloyloxy group.

[0023] In general formula (1), the number of polymerizable functional groups is preferably two or more from the viewpoint of curability, more preferably two or four from the viewpoint of ease of synthesis, and more preferably two from the viewpoint of secondary dispersion properties.

[0024] In addition to the polymerizable functional group, examples of the substituents that R1 to R4 may have include a methyl group and an ethyl group.

[0025] The number of trifluoromethyl groups represented by R5 to R9 in general formula (1) in the compound is preferably one from the viewpoint of transmittance, and the substitution position is more preferably the para position relative to the nitrogen atom, i.e., R7 in general formula (1), from the viewpoint of achieving both secondary dispersion properties and transmittance.

[0026] Preferred specific examples of the compound represented by formula (1) are shown below.

[0027] [Table 1]

[0028] The method for producing the compound represented by the above general formula (1) will be explained below using an example. The method for producing the compound represented by general formula (1) is not particularly limited, and the compound can be synthesized using a known synthesis method. For example, the compound can be synthesized using a known synthesis method described in JP-A-2018-165355.

[0029] There are two methods for providing a compound represented by general formula (1) with a polymerizable functional group. One is a method of directly introducing a polymerizable functional group to form a structure represented by general formula (1). The other is a method of introducing a structure having a polymerizable functional group or a functional group of a precursor of a polymerizable functional group into a precursor of the compound represented by general formula (1). The latter method includes, for example, a method of introducing a functional group-containing aryl group based on a monoarylamine derivative using a coupling reaction using a metal catalyst and a base.

[0030] The following methods can be used to make the compound represented by general formula (1) have an unsaturated hydrocarbon group (e.g., an acrylic group or a methacrylic group): a method of reacting a derivative having a structure represented by general formula (1) with a hydroxy group with a (meth)acrylate, or a method of directly introducing an unsaturated hydrocarbon group so as to have a structure represented by general formula (1).

[0031] Metal-catalyzed coupling reactions can be performed in any desired manner, including the Ullmann reaction using copper, the Buchwald-Hartwig reaction using amines, the Suzuki coupling using boric acid, the Stille coupling using organotin, and the Negishi coupling using organozinc.

[0032] Any method can be selected for the (meth)acrylate reaction. Typical methods include esterifying a hydroxyl group using a (meth)acrylic acid halide or (meth)acrylic anhydride, and transesterification using a lower alcohol ester of (meth)acrylic acid. Other suitable methods include direct esterification, in which (meth)acrylic acid and the diol undergo dehydration condensation using a dehydration condensing agent such as N,N'-dicyclohexylcarbodiimide, and heating (meth)acrylic acid and the diol in the presence of a dehydrating agent such as sulfuric acid.

[0033] A polymerization inhibitor may also be used in a resin composition containing a compound represented by general formula (1) to prevent polymerization during reaction or storage of the compound. Examples of usable inhibitors include hydroquinones such as p-benzoquinone, hydroquinone, hydroquinone monomethyl ether, and 2,5-diphenylparabenzoquinone, and N-oxy radicals such as tetramethylpiperidinyl-N-oxy radical (TEMPO). Other examples include substituted catechols such as t-butylcatechol, amines such as phenothiazine, diphenylamine, and phenyl-β-naphthylamine, nitrosobenzene, picric acid, molecular oxygen, sulfur, and copper(II) chloride. Among these, hydroquinones, phenothiazine, and N-oxy radicals are preferred in terms of versatility and polymerization inhibition, with hydroquinones being particularly preferred.

[0034] The amount of the polymerization inhibitor used relative to the compound represented by general formula (1) is usually 10 ppm or more, preferably 50 ppm or more, with the upper limit usually being 10,000 ppm or less, preferably 1,000 ppm or less. At 10 ppm or more, the effect as a polymerization inhibitor becomes significant, and the progress of polymerization during the reaction or during concentration in the post-treatment process can be suppressed. Furthermore, by using it at 10,000 ppm or less, the risk of adverse effects such as inhibiting polymerization reactivity as an impurity is reduced.

[0035] Next, a resin composition containing a compound represented by general formula (1) will be described. The resin composition used in the present invention contains a compound represented by general formula (1), a polymerization initiator, a polymerization inhibitor, and, if necessary, a photosensitizer, a heat stabilizer, a light stabilizer, an antioxidant, a monomer component copolymerizable with the compound, and a resin component.

[0036] The content of the compound represented by general formula (1) contained in the resin composition is preferably 1.0 mass % or more and 99 mass % or less, more preferably 50 mass % or more and 99 mass % or less, based on the total mass of the resin composition.

[0037] Examples of the polymerization initiator include, but are not limited to, those that generate radical species or cation species upon irradiation with light, and those that generate radical species upon heat. Examples of polymerization initiators that generate radical species upon irradiation with light include 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone and 1-hydroxycyclohexylphenyl ketone. Other examples include 2-hydroxy-2-methyl-1-phenylpropan-1-one, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 4-phenylbenzophenone, and 4-phenoxybenzophenone. Other examples include, but are not limited to, 4,4'-diphenylbenzophenone and 4,4'-diphenoxybenzophenone.

[0038] Furthermore, as a polymerization initiator that generates cationic species upon irradiation with light, a suitable example is iodonium(4-methylphenyl)[4-(2-methylpropyl)phenyl]-hexafluorophosphate, but is not limited to this.

[0039] Furthermore, examples of polymerization initiators that generate radical species by heat include azo compounds such as azobisisobutylnitrile (AIBN), benzoyl peroxide, t-butyl peroxypivalate, and t-butyl peroxyneohexanoate, as well as peroxides such as t-hexyl peroxyneohexanoate, t-butyl peroxyneodecanoate, t-hexyl peroxyneodecanoate, and cumyl peroxyneohexanoate, but are not limited to these.

[0040] When polymerization is initiated by irradiation with ultraviolet light or the like, known sensitizers can also be used. Examples of sensitizers include benzophenone, 4,4-diethylaminobenzophenone, and 1-hydroxycyclohexylphenyl ketone. Other examples include isoamyl p-dimethylaminobenzoate, methyl 4-dimethylaminobenzoate, benzoin, benzoin ethyl ether, benzoin isobutyl ether, benzoin isopropyl ether, and 2,2-diethoxyacetophenone. Other examples include, but are not limited to, methyl o-benzoylbenzoate, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and acylphosphine oxide.

[0041] The content ratio of the photopolymerization initiator to the polymerizable component (polymerizable component) can be appropriately selected depending on the amount of light irradiation and the additional heating temperature, and can also be adjusted depending on the target average molecular weight of the resulting polymer.

[0042] The content of the photopolymerization initiator used in the polymerization (curing) and molding of the resin composition used in the present invention is preferably in the range of 0.01% by mass to 10.00% by mass based on the polymerizable component. Depending on the reactivity of the polymerizable component and the wavelength of light irradiation, a single type of photopolymerization initiator can be used, or two or more types can be used in combination.

[0043] There are no particular limitations on the light resistance stabilizer, as long as it does not significantly affect the optical properties of the cured product. Typical examples include benzotriazole-based materials, such as 2-(2H-benzotriazol-2-yl)-p-cresol and 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol. Other examples include 2-[5-chloro(2H)-benzotriazol-2-yl]-4-methyl-6-(tert-butyl)phenol and 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol. Another example is 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol. Other examples include 2,2'-methylenedibis[6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)]phenol and 2-(2H-benzotriazol-2-yl)-6-dodecyl-4-methylphenol. Other examples include cyanoacrylate-based materials such as ethyl 2-cyano-3,3-diphenylacrylate and 2-ethylhexyl 2-cyano-3,3-diphenylacrylate. Other examples include triazine-based materials, benzophenone-based materials such as octabenzone and 2,2'-4,4'-tetrahydrobenzophenone. The light resistance stabilizer may also function as a photosensitizer, in which case it may not be added.

[0044] The content of the light resistance stabilizer used in the polymerization (curing) and molding of the resin composition used in the present invention is preferably in the range of 0.01% by mass to 10.00% by mass based on the total amount of polymerizable components.

[0045] The heat-resistant stabilizer is not particularly limited as long as it does not significantly affect the optical properties of the cured product. For example, hindered phenolic materials include pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)]propionate. Other examples include octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and benzenepropanoic acid 3,5-bis(1,1-dimethylethyl)-4-hydroxy, C7-C9 side chain alkyl ester. Other examples include 4,6-bis(octylthiomethyl)-o-cresol, 4,6-bis(dodecylthiomethyl)-o-cresol, and ethylenebis(oxyethylene)bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)]propionate. Other examples include hexamethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)]propionate. Furthermore, phosphorus-based materials such as tris(2,4-di-tert-butylphenyl) phosphite, sulfur-based materials such as dioctadecyl 3,3'-thiodipropionate, and the like can also be used.

[0046] The content of the heat resistance stabilizer used in the polymerization (curing) and molding of the resin composition used in the present invention is preferably in the range of 0.01% by mass to 10.00% by mass based on the total amount of polymerizable components.

[0047] The antioxidant is not particularly limited as long as it does not significantly affect the optical properties of the molded article, and representative examples include hindered amine-based materials, such as bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate and bis(1,2,2,6,6-pentamethyl-4-piperidyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonate.

[0048] The content of the antioxidant used in the polymerization (curing) and molding of the resin composition used in the present invention is preferably in the range of 0.01% by mass to 10.00% by mass based on the total amount of polymerizable components.

[0049] The monomer component copolymerizable with the compound represented by general formula (1) is not particularly limited, and examples thereof include 1,3-adamantanediol dimethacrylate, 1,3-adamantanedimethanol dimethacrylate, tricyclodecane dimethanol diacrylate, pentaerythritol tetraacrylate, propoxylated neopentyl glycol diacrylate, dipropylene glycol diacrylate, ethoxylated bisphenol A dimethacrylate, tris(2-hydroxyethyl)isocyanurate triacrylate, 2(2-ethoxy)ethyl acrylate, stearyl acrylate, tetrahydrofurfuryl acrylate, 2-phenoxyethyl acrylate, isodecyl acrylate, isobornyl acrylate, isobornyl methacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, diethylene glycol Lithium diacrylate, 1,6-hexanediol diacrylate, triethylene glycol diacrylate, tripropylene glycol diacrylate, dipropylene glycol diacrylate, triethylene glycol dimethacrylate, ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, diethylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, tripropylene glycol dimethacrylate, dipropylene glycol dimethacrylate, trimethylolpropane trimethacrylate, 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene, 9,9-bis[4-(2-methacryloyloxyethoxy)phenyl]fluorene, 9,9-Bis[4-(2-methacryloyloxy)phenyl]fluorene, benzyl acrylate, benzyl methacrylate, butoxyethyl acrylate, butoxymethyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxymethyl methacrylate, glycidyl acrylate, glycidyl methacrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate, phenyl methacrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate acrylate, ethylene glycol bisglycidyl acrylate, ethylene glycol bisglycidyl methacrylate, bisphenol A diacrylate, bisphenol A dimethacrylate, 2,2-bis(4-acryloxyethoxyphenyl)propane, 2,2-bis(4-methacryloxyethoxyphenyl)propane, 2,2-bis(4-acryloxydiethoxyphenyl)propane, 2,2-bis(4-methacryloxydiethoxyphenyl)propane, bisphenol F diacrylate, bis Phenol F dimethacrylate, 1,1-bis(4-acryloxyethoxyphenyl)methane, 1,1-bis(4-methacryloxyethoxyphenyl)methane, 1,1-bis(4-acryloxydiethoxyphenyl)methane, 1,1-bis(4-methacryloxydiethoxyphenyl)methane, 1,1-bis(4-acryloxyethoxyphenyl)sulfone, 1,1-bis(4-methacryloxyethoxyphenyl)sulfone, 1,1-bis(4-acryloxydiethoxyphenyl)sulfone, 1,1-Bis(4-methacryloxydiethoxyphenyl)sulfone, dimethyloltricyclodecane diacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, glycerol diacrylate, glycerol dimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, methyl thioacrylate, methyl thiomethacrylate, phenyl thioacrylate, benzyl thiomethacrylate, xylylenedithiol diacrylate, xylylenedithiol Examples of suitable acrylic resins include (meth)acrylate compounds such as aryl dimethacrylate, mercaptoethyl sulfide diacrylate, and mercaptoethyl sulfide dimethacrylate; allyl compounds such as allyl glycidyl ether, diallyl phthalate, diallyl terephthalate, diallyl isophthalate, diallyl carbonate, and diethylene glycol bisallyl carbonate; vinyl compounds such as styrene, chlorostyrene, methylstyrene, bromostyrene, dibromostyrene, divinylbenzene, and 3,9-divinylspirobi(m-dioxane); and diisopropenylbenzene, but are not limited to these. From the viewpoint of excellent optical properties and moldability, acrylic compounds and methacrylic compounds are particularly preferred.

[0050] The resin composition used in the present invention may also contain a thermoplastic resin, for example, polyolefin resins such as ethylene homopolymers, random or block copolymers of ethylene with one or more α-olefins such as propylene, 1-butene, 1-pentene, 1-hexene, and 4-methyl-1-pentene, random or block copolymers of ethylene with one or more α-olefins such as vinyl acetate, acrylic acid, methacrylic acid, methyl acrylate, and methyl methacrylate, propylene homopolymers, random or block copolymers of propylene with one or more α-olefins other than propylene such as 1-butene, 1-pentene, 1-hexene, and 4-methyl-1-pentene, 1-butene homopolymers, ionomer resins, and mixtures of these polymers; carbon resins such as petroleum resins and terpene resins. Examples of suitable resins include hydrogen hydride resins; polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyamide resins such as nylon 6, nylon 66, nylon 11, nylon 12, nylon 610, nylon 6 / 66, nylon 66 / 610, and nylon MXD; acrylic resins such as polymethyl methacrylate; styrene-acrylonitrile resins such as polystyrene, styrene-acrylonitrile copolymer, styrene-acrylonitrile-butadiene copolymer, and polyacrylonitrile; polyvinyl alcohol resins such as polyvinyl alcohol and ethylene-vinyl alcohol copolymer; polycarbonate resins; polyketone resins; polymethylene oxide resins; polysulfone resins; polyimide resins; and polyamide-imide resins. These may be used alone or in combination of two or more.

[0051] The content of the monomer component and the resin component contained in the resin composition is 0.01% by mass or more and 99% by mass or less. Considering the refractive index characteristics and brittleness of the cured product obtained from the resin composition, the content is preferably 0.01% by mass or more and 50% by mass or less. Furthermore, in order to maintain secondary dispersion characteristics and transmittance, it is more preferable to contain at least one of an acrylic compound and a methacrylic compound as a copolymerization component in a mass ratio of 0.01 to 0.20 relative to the compound represented by general formula (1).

[0052] [Optical element] Next, the optical element of the present invention will be described while referring to the drawings.

[0053] The optical element of the present invention is characterized by having a cured product made of a polymer of a resin composition containing a compound represented by the general formula (1). Since the cured product according to the present invention exhibits high secondary dispersion characteristics of 0.80 or more, in the optical element of the present invention, chromatic aberration can be efficiently removed.

[0054] FIG. 1 shows a schematic cross-sectional view in the thickness direction in one embodiment of the optical element of the present invention. In FIG. 1(a), a thin film of the cured product 1 is provided on one surface of the transparent substrate 2.

[0055] For the transparent substrate 2, a transparent resin or transparent glass can be used. Here, in this specification, transparent means that the transmittance in the entire visible light range (light with a wavelength in the range of 380 nm or more and 780 nm or less) is 30% or more. It is preferable to use glass for the transparent substrate 2. For example, general optical glasses typified by silicate glass, borosilicate glass, and phosphate glass, quartz glass, and glass ceramics can be used. The transparent substrate 2 is preferably circular in plan view.

[0056] As a method for producing the optical element of FIG. 1(a), for example, a method of forming a thin layer structure on a transparent substrate is adopted. Specifically, a mold made of a metal material is provided at a certain distance from the transparent substrate 2, and a resin composition having fluidity is filled into the gap between the mold and the transparent substrate 2, and then mold forming is performed by gently pressing. Then, polymerization of the resin composition is carried out while maintaining that state as necessary.

[0057] The light irradiation used for the polymerization reaction is carried out using light of a suitable wavelength, typically ultraviolet or visible light, depending on the mechanism resulting from radical generation using a photopolymerization initiator. For example, light is uniformly irradiated onto raw materials such as monomers of the resin composition through a light-transmitting material used as the transparent substrate 2. The amount of light irradiation is appropriately selected depending on the mechanism resulting from radical generation using the photopolymerization initiator and the content ratio of the photopolymerization initiator contained.

[0058] On the other hand, when curing a resin composition by such a photopolymerization reaction, it is more preferable that the irradiated light is uniformly applied to the entire molded resin composition. Therefore, it is more preferable to select light of a wavelength that allows uniform irradiation through the light-transmitting material used for the transparent substrate 2. In this case, it is more suitable for the present invention to reduce the thickness of the cured product 1 formed on the transparent substrate 2.

[0059] FIG. 1(b) shows a thin film of a cured product 1 obtained by curing the resin composition sandwiched between a first transparent substrate 3 and a second transparent substrate 4. In FIG. 1(b), the transparent substrates 3 and 4 each have a concave surface on the opposing side and are in contact with each other at their peripheries, resulting in a cured product 1 in the form of a lens with convex surfaces on both sides. The transparent substrates 3 and 4 can be made of a transparent resin or transparent glass, preferably glass. Examples of glass that can be used include common optical glasses such as silicate glass, borosilicate glass, and phosphate glass, as well as quartz glass and glass ceramics. The transparent substrates 3 and 4 are preferably circular when viewed from above.

[0060] 1(b), for example, the resin composition is poured between transparent substrates 3 and 4 and gently pressed down to form the resin composition. While maintaining this state, the resin composition is photopolymerized. This results in a laminate in which the cured product 1 is sandwiched between the transparent substrates 3 and 4.

[0061] Similarly, the cured product 1 can also be produced by thermal polymerization. In this case, it is desirable to make the overall temperature more uniform, and reducing the total thickness of the cured product of the resin composition formed on the substrate of the light-transmitting material is more suitable for the present invention. Furthermore, when increasing the total thickness of the cured product of the resin composition to be formed, it is necessary to select the irradiation amount, irradiation intensity, light source, etc., taking into consideration the film thickness and the absorption of each component.

[0062] [Optical equipment] Specific application examples of the optical element of the present invention will be described. Specific application examples include lenses constituting optical equipment (photography optical systems) for cameras and video cameras, and lenses constituting optical equipment (projection optical systems) for liquid crystal projectors. The optical element can also be used as a pickup lens for DVD recorders and the like. These optical systems are comprised of at least one lens arranged in a housing, and at least one of the lenses can be the optical element described above.

[0063] [Imaging device] Fig. 2 shows a preferred embodiment of an imaging device using the optical element of the present invention, and illustrates the configuration of a single-lens reflex digital camera 10. Fig. 2 is a schematic cross-sectional view including the optical axis of the optical element used. In Fig. 2, a camera body 12 is coupled to a lens barrel 11, which is an optical device, and the lens barrel 11 is a so-called interchangeable lens that can be attached to and detached from the camera body 12.

[0064] Light from a subject is photographed via an optical system consisting of multiple lenses 13, 15, etc., arranged on the optical axis of the photographing optical system within housing 30 of lens barrel 11. The optical element of the present invention can be used, for example, for lenses 13, 15. Here, lens 15 is supported by inner barrel 14 and is movably supported relative to the outer barrel of lens barrel 11 for focusing and zooming.

[0065] During the observation period before shooting, light from the subject is reflected by the main mirror 17 inside the camera body housing 31, passes through a prism 21, and then is projected to the photographer through a viewfinder lens 22. The main mirror 17 is, for example, a half mirror, and light passing through the main mirror is reflected by a sub-mirror 18 toward an AF (autofocus) unit 23. This reflected light is used, for example, for distance measurement. The main mirror 17 is attached and supported by a main mirror holder 40, for example, by adhesive. During shooting, a drive mechanism (not shown) moves the main mirror 17 and sub-mirror 18 out of the optical path, opens the shutter 19, and allows the image sensor 20 to receive light that has entered through the lens barrel 11 and passed through the shooting optical system, forming a shooting light image. The aperture 16 is configured so that the brightness and depth of focus during shooting can be changed by changing the aperture area.

[0066] Although the imaging device has been described here using a single-lens reflex digital camera, the optical element of the present invention can also be used in mobile devices such as smartphones and tablets, compact digital cameras, and the like. [Example]

[0067] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples unless it deviates from the gist of the invention. The synthesized products were analyzed using an NMR device (product name "JNM-ECA400" manufactured by JEOL Ltd.).

[0068] [Synthesis Example 1: Exemplary Compound M1] (1) Synthesis of intermediate A The following components were placed in a 500 mL three-neck flask under a nitrogen atmosphere to form a mixture. 2-aminofluorene 10.0g 2-Iodo-9,9-dimethylfluorene 17.66g 4-Bromobenzotrifluoride 12.42g Sodium tert-butoxide 21.21g Bis(dibenzylideneacetone)palladium 0.32g 2-Dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl 0.53g Orthoxylene 350mL The mixture was heated to 120°C and stirred at that temperature for 6 hours. The mixture was allowed to cool to 25°C, and the organic phase was extracted with ethyl acetate. The resulting organic phase was washed with saturated brine and water, and then dried over anhydrous magnesium sulfate. The resulting crude product was purified by column chromatography to obtain 16.0 g of intermediate A (yield 62%).

[0069] (2) Synthesis of intermediate B Under a nitrogen atmosphere, 15.0 g of intermediate A obtained in (1) above and 160 mL of N,N-dimethylacetamide were placed in a 500 mL three-neck flask and stirred. Then, 9.7 g of sodium tert-butoxide was added and the flask was cooled to 5°C. A solution of 14.5 g of 4-bromobutyl acetate in 40 mL of N,N-dimethylacetamide was added dropwise over 30 minutes. After the dropwise addition, the flask was heated to 20°C and stirred at that temperature (20°C) for 20 hours. After stirring, the flask was cooled to 5°C, and 4.7 g of sodium methoxide was added. The temperature was gradually raised to 20°C. After the temperature was raised, the flask was stirred at that temperature (20°C) for 10 hours. After stirring, the reaction mixture was poured into ice water, and the organic layer was extracted with toluene. The resulting organic phase was washed with saturated brine and then water and dried over anhydrous magnesium sulfate. The resulting crude product was purified by column chromatography to obtain 10.6 g of intermediate B (yield: 55%).

[0070] (3) Synthesis of M1 Under a nitrogen atmosphere, 8.0 g of intermediate B obtained in (2) above, 350 mL of tetrahydrofuran, 0.09 g of hydroquinone monomethyl ether (MEHQ), 0.02 g of 4-dimethylaminopyridine, and 8.5 mL of triethylamine were added to a 500 mL three-neck flask and then cooled to 10°C. Then, 7.5 g of methacrylic anhydride was added dropwise, and the temperature was gradually raised to 20°C. After the temperature was raised, the mixture was stirred at that temperature (20°C) for 10 hours. The reaction solution was diluted with toluene, and the resulting organic phase was washed with acidic and basic aqueous solutions. The organic phase was then dried over saturated saline and anhydrous magnesium sulfate. The solvent was removed, and the resulting crude product was purified by silica gel chromatography to obtain 7.3 g (75% yield) of exemplary compound M1 listed in Table 1.

[0071] Example 1 (1) Quadratic dispersion characteristics (θ g,F ) measurement A resin composition was placed on a 1 mm-thick high-refractive index glass substrate ("S-TIH11" manufactured by HOYA CORPORATION). The resin composition contained 4 g of the exemplary compound M1 synthesized in Synthesis Example 1 above, 0.2 g of copolymerization component 1 (1,6-hexanediol methacrylate, manufactured by Tokyo Chemical Industry Co., Ltd.), 0.001 g of a polymerization inhibitor (methoxyphenol, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 0.015 g of a polymerization initiator (diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, manufactured by Tokyo Chemical Industry Co., Ltd.). Next, a quartz glass plate was placed on the resin composition to be measured and spread to a thickness of 500 μm via a spacer. The resin composition sandwiched between the two glass substrates was cured by irradiating the sample with a high-pressure mercury lamp ("EX250" manufactured by HOYA-SCHOTT CORPORATION) equipped with a short-wavelength cut filter (UV: 385 nm) as a light source. After curing, the resin was heated at 100°C for 12 hours to complete the reaction, and a measurement sample was prepared. The refractive index of the measurement sample was measured using an Abbe refractometer (manufactured by Kalnew Optical Co., Ltd.), and the second-order dispersion characteristic (θ g,F ) was calculated and evaluated according to the following criteria. The glass substrate used had a refractive index higher than that of the cured product of the resin composition. The evaluation results are shown in Table 2. The evaluation criteria are as follows: A: 0.84 or higher B: 0.82 or more and less than 0.84 C: 0.80 or more and less than 0.82

[0072] (2) Transmittance measurement In the same manner as in the measurement of the second-order dispersion characteristics described above, a 500 μm-thick transmittance measurement sample and a 1000 μm-thick transmittance measurement sample were prepared. Note that the refractive index measurement sample prepared for measuring the second-order dispersion characteristics described above may be used as the 500 μm-thick transmittance measurement sample. The transmittance of the transmittance measurement samples of each film thickness was measured using a spectrophotometer (product name "U-4000" manufactured by Hitachi High-Technologies Corporation), converted into internal transmittance (1000 μm) at a wavelength of 450 nm, and evaluated according to the following criteria. The evaluation results are shown in Table 2. The evaluation criteria are as follows: A: 98% or more B: 97% or more but less than 98% C: 96% to less than 97%

[0073] Examples 2 to 10 As shown in Table 2, the sample was prepared in the same manner as in Example 1, except that the type of the exemplary compound, the copolymerization component, and the mass ratio of the exemplary compound and the copolymerization component were changed. g,F The evaluation results are shown in Table 2. Copolymerization component 2: Triethylene glycol dimethacrylate (Tokyo Chemical Industry Co., Ltd.) Copolymerization component 3: Tricyclodecane dimethanol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.)

[0074] (Comparative Example 1) A resin composition was prepared in the same manner as in Example 1, except that the exemplary compound M1 was replaced with the comparative compound R1 described below. However, the comparative compound R1 was not compatible with the other components and precipitated, resulting in poor secondary dispersion properties (θ g,F ) and transmittance measurements were not performed.

[0075] [ka]

[0076] [Table 2]

[0077] As shown in Table 2, the cured products of Examples 1 to 10 all had secondary dispersion properties of 0.80 or more and high transmittances of 96% or more at a wavelength of 450 nm. On the other hand, the resin composition of Comparative Example 1 had high crystallinity of Comparative Example Compound R1, which was incompatible with the other components, making it impossible to evaluate secondary dispersion properties and transmittance. Examples 1, 2, and 5 to 10 had higher transmittances at a wavelength of 450 nm than Examples 3 and 4. This is thought to be due to the fact that the compounds represented by general formula (1) in the resin compositions of Examples 3 and 4 have two trifluoromethyl groups.

[0078] Furthermore, Examples 1 to 6, 8, and 9 exhibited higher secondary dispersion properties than Examples 7 and 10. This is thought to be due to the fact that the compound represented by general formula (1) in the resin composition of Example 7 has four polymerizable functional groups, and that in Example 10, the mass ratio of the copolymerization component to the compound represented by general formula (1) is 0.30. In other words, it can be seen that high secondary dispersion properties and high transmittance can be obtained by having two polymerizable functional groups and a mass ratio of the copolymerization component to the compound represented by general formula (1) of 0.01 or more and 0.20 or less.

[0079] Furthermore, it can be seen that in the compound represented by general formula (1), by bonding a trifluoromethyl group to the R7 position in general formula (1), both higher secondary dispersion characteristics and higher transmittance can be achieved.

[0080] From the above, it can be seen that the cured resin composition containing the compound represented by general formula (1) has high secondary dispersion properties (θ g,F ) and high transmittance. [Explanation of symbols]

[0081] 1: cured product, 2, 3, 4: transparent substrate, 10: digital camera (imaging device), 13, 15: lenses, 20: imaging element, 30: housing

Claims

1. A cured product of a resin composition, characterized in that the resin composition contains a compound represented by the following general formula (1) and at least one of an acrylic compound and a methacrylic compound copolymerizable with the compound represented by the general formula (1), wherein the mass ratio of the acrylic compound and the methacrylic compound to the compound represented by the general formula (1) is in the range of 0.01 or more and 0.30 or less. 【Chemistry 1】 In general formula (1), R 1 ~R 4 each independently represents a CH in the main chain of a polymerizable functional group, a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms and having a polymerizable functional group at the terminal, or a substituted or unsubstituted alkyl group having 2 to 6 carbon atoms and having a polymerizable functional group at the terminal. 2 is selected from groups in which one of the groups is substituted with an oxygen atom or a sulfur atom. R 5 ~R 9 are each independently selected from a hydrogen atom and a trifluoromethyl group. However, R 1 ~R 4 At least one of R is a polymerizable functional group or a substituent having a polymerizable functional group, 5 ~R 9 At least one of these has a trifluoromethyl group. The polymerizable functional group is an acryloyloxy group or a methacryloyloxy group.

2. The cured product according to claim 1 , wherein the polymerizable functional groups are two.

3. 3. The cured product according to claim 1, wherein the number of the trifluoromethyl groups is one or two.

4. The number of the trifluoromethyl groups is one, and the R 7 The cured product according to claim 3, characterized in that is a trifluoromethyl group.

5. An optical element comprising the cured product according to claim 1 .

6. 6. The optical element according to claim 5, further comprising a transparent substrate, the cured product being disposed on the transparent substrate.

7. 6. The optical element according to claim 5, further comprising a first transparent substrate and a second transparent substrate, wherein the cured product is sandwiched between the first transparent substrate and the second transparent substrate.

8. 8. An optical device comprising a housing and an optical system having at least one lens disposed within the housing, wherein at least one of the lenses is an optical element according to any one of claims 5 to 7.

9. 8. An imaging device comprising: a housing; an optical system having at least one lens disposed within the housing; and an imaging element that receives light that has passed through the optical system, wherein at least one of the lenses is an optical element according to any one of claims 5 to 7.

10. 10. The imaging device according to claim 9, wherein the imaging device is a camera.

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