Polymer and resin composition for optical lens

Abstract

Provided is a polymer which has both a high refractive index and excellent lens moldability and contains a structural unit represented by formula (1) (however, a structural unit represented by formula (1a) is excluded). (In the formula, X each independently represents a methyl group, an ethyl group, a methoxy group, an ethoxy group or a hydroxy group, and n represents an integer of 1-6.)

Description

Polymer and resin composition for optical lens

[0001] The present invention relates to a polymer, a resin composition for optical lenses, and a microlens obtained from the resin composition.

[0002] In recent years, in the field of electronic devices such as liquid crystal displays, organic EL displays, light-emitting diodes, solar cells, and CCD / CMOS image sensors, resin compositions employing polymeric materials with high refractive indexes have been widely used for optical components such as protective films, planarizing films, insulating films, anti-reflection films, refractive index control films, microlenses, inner-layer lenses, optical waveguides, and film substrates. For example, by applying a high refractive index material to a microlens for a CCD / CMOS image sensor, improvement in sensor performance can be expected.

[0003] One known method for manufacturing microlenses for CCD / CMOS image sensors is the etch-back method (see Patent Documents 1 and 2). Specifically, a resist pattern is formed on a microlens resin layer formed on a color filter layer, and the resist pattern is reflowed by heat treatment to form a lens pattern. Using the lens pattern formed by reflowing the resist pattern as an etching mask, the underlying microlens resin layer is etched back, and the lens pattern shape is transferred to the microlens resin layer, thereby producing a microlens.

[0004] In the etch-back method, the lens formability by dry etching is important. For example, when transferring the lens pattern shape to the underlying microlens resin layer, it is required that the dry etching rate X of the lens pattern and the dry etching rate Y of the microlens resin layer are equivalent (X:Y=1:0.8 to 1.2) (Patent Document 3). In addition, to improve the light collection efficiency, it is desirable that the gap between adjacent microlenses is narrow. In other words, a material is required that allows the width of the microlenses formed after dry etching to be larger than the width of the lens pattern before dry etching. Such lens formability depends largely on the material of the microlens resin layer.

[0005] On the other hand, known means for increasing the refractive index of a polymeric material include introducing into the molecule of the polymeric material aromatic rings, halogen atoms other than fluorine atoms, sulfur atoms, metal atoms, hydrogen bonds, etc. For example, it has recently been discovered that polyphenylene sulfide having phenolic hydroxy groups is a polymeric material with a high refractive index due to the effects of introducing aromatic rings, sulfur atoms, and hydrogen bonds (Patent Document 4 and Non-Patent Document 1).

[0006] Japanese Patent Laid-Open No. 1-10666 Japanese Patent Laid-Open No. 6-112459 International Publication No. 2013 / 005619 International Publication No. 2022 / 065381 Japanese Patent Laid-Open No. 2015-168790 Japanese Patent Laid-Open No. 2017-52834

[0007] Macromolecules, 2022, 55, 6, 2252-2259

[0008] However, experiments by the present inventors revealed that although polyphenylene sulfide having a phenolic hydroxy group certainly has a high refractive index, it is not necessarily a suitable material from the viewpoint of lens formability. There has been a demand for the development of a material that not only exhibits a high refractive index but also has excellent lens formability.

[0009] The present invention has been made in light of the above circumstances, and an object of the present invention is to provide a polymer and a resin composition that combine a high refractive index with excellent lens moldability.

[0010] As a result of extensive research into solving the above problems, the present inventors have found that the above problems can be solved by using a polynaphthylene sulfide resin, and have thus completed the present invention.

[0011] That is, the present invention provides the following [1] to

[11] : [1] A polymer containing a structural unit represented by the following formula (1) (excluding the structural unit represented by the following formula (1a)). (In the formula, X's each independently represent a methyl group, an ethyl group, a methoxy group, an ethoxy group, or a hydroxy group, and n represents an integer of 1 to 6.) [2] A polymer of [1], wherein n represents 1 in the structural unit represented by formula (1). [3] A polymer of [1] or [2], wherein X represents a methyl or ethyl group in the structural unit represented by formula (1). [4] A polymer of [1] or [2], wherein X represents a methoxy group or an ethoxy group in the structural unit represented by formula (1). [5] A polymer of [1] or [2], wherein X represents a hydroxy group in the structural unit represented by formula (1). [6] A method for producing a polymer containing a structural unit represented by formula (1), comprising a step of oxidatively polymerizing a disulfide monomer represented by formula (2) below (excluding a disulfide monomer represented by formula (2a) below) and / or a thiol monomer represented by formula (3) below (excluding a thiol monomer represented by formula (3a) below). (In the formula, X and n are defined as in formula (1) above.) [7] A resin composition for optical lenses, comprising (A) the polymer of [1] or [2] and / or a polymer containing a structural unit represented by the following formula (4), and (B) an organic solvent: [8] The resin composition for optical lenses according to [7], wherein the component (B) includes at least one organic solvent selected from the group consisting of ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, ethyl lactate, n-butyl lactate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, 2-heptanone, cyclopentanone, cyclohexanone, γ-butyrolactone, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, and N-ethyl-2-pyrrolidone. [9] The resin composition for optical lenses according to [7], further comprising (C) a polyfunctional epoxy compound.

[10] The resin composition for optical lenses according to [7], which is used for producing microlenses.

[11] A microlens obtained from the resin composition for optical lenses according to

[10] .

[0012] According to the present invention, a resin film containing a polynaphthylene sulfide resin exhibits a high refractive index of 1.75 or more at a wavelength of 550 nm, and it is possible to form microlenses with narrow gaps between adjacent lenses by an etch-back method.

[0013] The polymer and resin composition for optical lenses of the present invention will be described in more detail below. The resin composition for optical lenses of the present invention is characterized by containing the components (A) and (B) described below. In the following description, the solid content refers to the components other than the solvent that constitute the resin composition.

[0014] [Polymer] The polymer of the present invention is not particularly limited as long as it contains a structural unit represented by the following formula (1) (excluding the structural unit represented by the following formula (1a)).

[0015] (In the formula, X's each independently represent a methyl group, an ethyl group, a methoxy group, an ethoxy group, or a hydroxy group, and n represents an integer of 1 to 6.)

[0016] Examples of the structural unit of the polymer include structural units represented by the following formulae (1ba) to (1bn), (1ca) to (1cn), (1da) to (1dn), (1ea) to (1en), and (1fn) to (1fn).

[0017]

[0018] (In the formula, OMe represents a methoxy group.)

[0019] (In the formula, OEt represents an ethoxy group.)

[0020] (In the formula, Me represents a methyl group.)

[0021] (In the formula, Et represents an ethyl group.)

[0022] The proportion of the structural unit represented by formula (1) (excluding the structural unit represented by formula (1a)) in the polymer is preferably 10 mol % or more, more preferably 30 mol % or more, even more preferably 50 mol % or more, and even more preferably 80 mol % or more. By setting the proportion of the structural unit within the above range, it becomes possible to produce microlenses with a narrower gap between adjacent lenses.

[0023] In the formula (1), X represents a methyl group, an ethyl group, a methoxy group, an ethoxy group, or a hydroxy group, and among these, a methyl group, a methoxy group, or a hydroxy group is preferred, and a hydroxy group is particularly preferred from the viewpoint of improving solubility in organic solvents and improving refractive index. In addition, in the formula (1), n ​​is preferably 1 from the viewpoint of ease of synthesis.

[0024] The molecular weight of the polymer is preferably 500 to 100,000, more preferably 1,000 to 30,000, and even more preferably 1,000 to 10,000, as a weight average molecular weight calculated in terms of polystyrene standards by gel permeation chromatography (GPC).

[0025] The polymer can be synthesized, for example, by applying various known methods for producing polyarylene sulfides to a naphthalene derivative (such as polycondensation using an aromatic halogen compound and sodium sulfide, or oxidative polymerization of an aromatic thiol compound or an aromatic disulfide compound). A polymer having hydroxy groups may be synthesized by applying various known methods for producing polyarylene sulfides to a naphthol derivative in which the hydroxy groups are protected, and then deprotecting some or all of the protecting groups.

[0026] The method for producing the polymer is preferably an oxidative polymerization method. In particular, from the viewpoint of being able to produce the polymer at room temperature and normal pressure without using a metal catalyst, the oxidative polymerization method using a quinone-based oxidizing agent and an acid, as described in Patent Document 5 and Patent Document 6, is preferably used. Specific methods for producing the polymer include a method of oxidatively polymerizing an aromatic thiol compound containing a methyl group, an ethyl group, a methoxy group, an ethoxy group, or a hydroxy group, or an aromatic disulfide compound containing a methyl group, an ethyl group, a methoxy group, an ethoxy group, or a hydroxy group, as a monomer, using a quinone-based oxidizing agent and an acid, and a method of oxidatively polymerizing an aromatic thiol compound containing a protected hydroxy group, or an aromatic disulfide compound containing a protected hydroxy group, as a monomer, using a quinone-based oxidizing agent and an acid, followed by deprotection of some or all of the protecting groups. The protected hydroxy group is not particularly limited as long as polymerization proceeds, but is preferably an alkoxy group from the viewpoint of stability in that it does not interfere with the quinone-based oxidizing agent or the acid, and more preferably a methoxy group or an ethoxy group. A methoxy group is particularly preferred because it allows the deprotection reaction to proceed more easily. The alkoxy group can be converted to a hydroxy group by removing the alkyl group through the action of an acid, etc. Examples of the acid include Lewis acids such as trisubstituted boron compounds (e.g., boron tribromide) and aluminum chloride, and Bronsted acids such as thiol compounds (e.g., dodecanethiol) and hydrogen bromide, but are not particularly limited as long as they can be converted to a hydroxy group. All protecting groups may be deprotected, or some may remain. By appropriately adjusting the deprotection rate, the optical properties and solubility can be controlled.

[0027] When the oxidative polymerization method is used, the disulfide monomer represented by the formula (2) (excluding the disulfide monomer represented by the formula (2a)) and / or the thiol monomer represented by the formula (3) (excluding the thiol monomer represented by the formula (3a)) can be preferably used.

[0028] The monomers used in the synthesis of the polymer may be used alone or in combination of two or more. From the viewpoint of adjusting optical properties and solubility in organic solvents, a disulfide monomer not represented by formula (2) or a thiol monomer not represented by formula (3) may be used as necessary. That is, the polymer may contain at least one structural unit represented by formula (1), and may be either a homopolymer or a copolymer. When the polymer is a copolymer, its repeating structure is not particularly limited, and it may be any of an alternating copolymer, a block copolymer, a gradient copolymer, and a random copolymer. Furthermore, the polymer may be branched depending on the polymerization conditions.

[0029] [Component (A)] The component (A) is not particularly limited as long as it is a polymer containing a structural unit represented by formula (1) (excluding the structural unit represented by formula (1a)) and / or a polymer containing a structural unit represented by formula (4). Furthermore, the component (A) may contain structural units other than the structural units represented by formula (1) and formula (4) as long as the effects of the present invention are not impaired. Examples of the structural units other than the structural units represented by formula (5) to formula (17) below can be mentioned.

[0030] (In the formula, OMe represents a methoxy group.)

[0031] The proportion of the structural unit represented by formula (1) (excluding the structural unit represented by formula (1a)) and / or the structural unit represented by formula (4) in component (A) is preferably 10 mol % or more, more preferably 30 mol % or more, even more preferably 50 mol % or more, and even more preferably 80 mol % or more. By setting the proportion of the structural unit within the above range, it is possible to produce microlenses with narrower gaps between adjacent lenses.

[0032] The structural unit represented by the formula (1) has reduced crystallinity due to the presence of a substituent, and is therefore superior to the structural unit represented by the formula (4) in terms of solubility in organic solvents. X in the formula (1) represents a methyl group, an ethyl group, a methoxy group, an ethoxy group, or a hydroxy group, and among these, a methyl group, a methoxy group, or a hydroxy group is preferred, and a hydroxy group is particularly preferred from the viewpoints of improving solubility in organic solvents and improving the refractive index. Furthermore, from the viewpoint of ease of synthesis, n in the formula (1) is preferably 1.

[0033] The molecular weight of component (A) is preferably 500 to 100,000, more preferably 1,000 to 30,000, and even more preferably 1,000 to 10,000, as calculated by gel permeation chromatography (GPC) and converted into polystyrene equivalent weight average molecular weight.

[0034] The component (A) can be synthesized, for example, by applying various known polyarylene sulfide production methods to a naphthalene derivative (such as polycondensation using an aromatic halogen compound and sodium sulfide, or oxidative polymerization of an aromatic thiol compound or an aromatic disulfide compound). A polymer having hydroxy groups may be synthesized by applying various known polyarylene sulfide production methods to a naphthol derivative in which the hydroxy groups are protected, and then deprotecting some or all of the protecting groups.

[0035] The preferred method for producing component (A) is oxidative polymerization. From the viewpoint of enabling production at room temperature and normal pressure without using a metal catalyst, the oxidative polymerization method using a quinone-based oxidizing agent and an acid, as described in Patent Documents 5 and 6, is particularly preferred. Specific methods for producing component (A) include a method of oxidatively polymerizing an aromatic thiol compound that may contain a methyl group, an ethyl group, a methoxy group, an ethoxy group, or a hydroxy group, or an aromatic disulfide compound that may contain a methyl group, an ethyl group, a methoxy group, an ethoxy group, or a hydroxy group, as a monomer, using a quinone-based oxidizing agent and an acid, and a method of oxidatively polymerizing an aromatic thiol compound that contains a protected hydroxy group, or an aromatic disulfide compound that contains a protected hydroxy group, as a monomer, using a quinone-based oxidizing agent and an acid, followed by deprotection of some or all of the protecting groups. The protected hydroxy group is not particularly limited as long as polymerization proceeds, but is preferably an alkoxy group from the viewpoint of stability, not interfering with the quinone-based oxidizing agent or the acid, and more preferably a methoxy group or an ethoxy group. A methoxy group is particularly preferred because it allows the deprotection reaction to proceed more easily. The alkoxy group can be converted to a hydroxy group by removing the alkyl group through the action of an acid, etc. Examples of the acid include Lewis acids such as trisubstituted boron compounds (e.g., boron tribromide) and aluminum chloride, and Bronsted acids such as thiol compounds (e.g., dodecanethiol) and hydrogen bromide, but are not particularly limited as long as they can be converted to a hydroxy group. All protecting groups may be deprotected, or some may remain. By appropriately adjusting the deprotection rate, the optical properties and solubility can be controlled.

[0036] When a polymer containing a structural unit represented by the formula (1) (excluding the structural unit represented by the formula (1a)) is synthesized using an oxidative polymerization method, a disulfide monomer represented by the formula (2) (excluding the disulfide monomer represented by the formula (2a)) and / or a thiol monomer represented by the formula (3) (excluding the thiol monomer represented by the formula (3a)) can be suitably used. Furthermore, when a polymer containing a structural unit represented by the formula (4) is synthesized using an oxidative polymerization method, a disulfide monomer represented by the following formula (18) and / or a thiol monomer represented by the following formula (19) can be suitably used.

[0037]

[0038] The monomer used in the synthesis of component (A) may be used alone or in combination of two or more. From the viewpoint of adjusting optical properties and solubility in organic solvents, disulfide monomers not represented by formula (2) and formula (18) (e.g., disulfide monomers represented by formulas (20) to (38) below) or thiol monomers not represented by formula (3) and formula (19) (e.g., thiol monomers represented by formulas (39) to (57) below) may be used, as necessary. That is, the polymer may contain at least one structural unit represented by formula (1) or formula (4) and may be either a homopolymer or a copolymer. When the polymer is a copolymer, its repeating structure is not particularly limited and may be any of an alternating copolymer, a block copolymer, a gradient copolymer, and a random copolymer. Furthermore, the polymer may be branched depending on the polymerization conditions.

[0039] (In the formula, OMe represents a methoxy group.)

[0040] (In the formula, OMe represents a methoxy group.)

[0041] [Component (B)] Component (B) is not particularly limited as long as it is an organic solvent that dissolves component (A). Among them, an organic solvent having a melting point of 15°C or less and a boiling point of 85°C or more is desirable. Here, melting point and boiling point refer to those at 1 atmosphere. A melting point of 15°C or less provides excellent handleability at room temperature for the resin composition. From the viewpoint of storage in a cold place, the melting point is preferably 10°C or less, more preferably 5°C or less. The lower limit of the melting point is not particularly limited, but is preferably, for example, -150°C or more. On the other hand, a boiling point of 85°C or more makes it difficult for the coating film formed by applying the resin composition to a substrate to whiten. The boiling point is preferably 100°C or more, more preferably 115°C or more, from the viewpoint of facilitating the formation of a homogeneous coating film. The upper limit of the boiling point is preferably 300°C or less, more preferably 250°C or less, and even more preferably 220°C or less, from the viewpoint of organic solvent removability.

[0042] Specific examples of component (B) include methylcyclohexane, ethylcyclohexane, n-heptane, toluene, o-xylene, m-xylene, mesitylene, chlorobenzene, o-dichlorobenzene, m-dichlorobenzene, anisole, phenetole, di-n-propyl ether, di-n-butyl ether, diisobutyl ether, di-n-pentyl ether, diisopentyl ether, di-n-hexyl ether, n-butyl ethyl ether, methyl-n-pentyl ether, cyclopentyl methyl ether, tetrahydropyran, 1,3-dioxane, and the like. ethanol, 1,4-dioxane, 1-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, 1-pentanol, 2-pentanol, 3-pentanol, cyclopentanol, benzyl alcohol, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether, triethylene glycol monomethyl ether, triethylene glycol dimethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol dimethyl ether, dipropylene glycol monomethyl ether , dipropylene glycol dimethyl ether, n-butyl formate, isobutyl formate, n-pentyl formate, isopentyl formate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, tert-butyl acetate, n-pentyl acetate, isopentyl acetate, n-hexyl acetate, isohexyl acetate, n-heptyl acetate, isoheptyl acetate, n-octyl acetate, isooctyl acetate, ethylene glycol monomethyl ether acetate,Ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol diacetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, propylene glycol diacetate, triacetin, ethyl propionate butyl propionate, n-propyl propionate, isopropyl propionate, n-butyl propionate, isobutyl propionate, tert-butyl propionate, propylene glycol monomethyl ether propionate, methyl butyrate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, n-butyl butyrate, isobutyl butyrate, tert-butyl butyrate, methyl isobutyrate, ethyl isobutyrate, n-propyl isobutyrate, isopropyl isobutyrate, n-butyl isobutyrate, isobutyl isobutyrate Butyl isobutyrate, tert-butyl isobutyrate, methyl lactate, ethyl lactate, n-propyl lactate, isopropyl lactate, n-butyl lactate, isobutyl lactate, tert-butyl lactate, methyl acetoacetate, ethyl acetoacetate, n-propyl acetoacetate, isopropyl acetoacetate, n-butyl acetoacetate, isobutyl acetoacetate, tert-butyl acetoacetate, dimethyl malonate, diethyl malonate, methyl glycolate, ethyl glycolate, methyl pyruvate, pyruvate ethyl propionate, ethyl ethoxyacetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, dimethyl carbonate, diethyl carbonate, 2-pentanone, 3-pentanone, cyclopentanone, 2,4-pentanedione, 4-methyl-2-pentanone, 4-hydroxy-4-methyl-2-pentanone, 2-hexanone, 3-hexanone, 3-methyl-2-hexanone, 5-methyl-2-hexanone, 2-methyl-3-hexanone, 5-methyl-3-hexanone,Examples of the alkyl esters include cyclohexanone, 2-methylcyclohexanone, 3-methylcyclohexanone, 4-methylcyclohexanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-methyl-3-heptanone, 5-methyl-3-heptanone, 2,6-dimethyl-4-heptanone, cycloheptanone, γ-butyrolactone, γ-valerolactone, γ-caprolactone, δ-valerolactone, δ-caprolactone, ε-caprolactone, N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylisobutyramide, N-methyl-2-pyrrolidone, and N-ethyl-2-pyrrolidone.

[0043] From the viewpoint of improving the leveling properties of a coating film formed by applying the resin composition to a substrate, the component (B) is preferably ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, ethyl lactate, n-butyl lactate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, 2-heptanone, cyclopentanone, cyclohexanone, γ-butyrolactone, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, or N-ethyl-2-pyrrolidone, and from the viewpoint of the solubility of the component (A), cyclopentanone or γ-butyrolactone is particularly preferred.

[0044] The component (B) may be used alone or in combination of two or more. It may also be appropriately mixed with a solvent other than the component (B). In this case, the content of the component (B) is preferably 50% by mass to 100% by mass, more preferably 60% by mass to 100% by mass, and even more preferably 70% by mass to 100% by mass of the total solvent including the component (B) and other solvents.

[0045] Specific examples of the other solvents include methanol, ethanol, 2-propanol, dichloromethane, 1,2-dichloroethane, chloroform, acetone, 2-butanone, dimethyl sulfoxide (DMSO), tetrahydrofuran (THF), ethyl acetate, and acetonitrile.

[0046] [(C) Polyfunctional Epoxy Compound] The resin composition of the present invention may further contain (C) a polyfunctional epoxy compound for the purpose of improving chemical resistance. The component (C) is not particularly limited as long as it is a compound having at least two oxirane rings in the molecule, and for example, the following products and compounds can be used. TEPIC (registered trademark)-G, -L, -VL, -S, -SP, -SS, and -HP (all manufactured by Nissan Chemical Industries, Ltd.), Marproof (registered trademark) G-01100, G-0105SA, G-0130SF, G-0130SP, G-0150M, G-0250SF, G-0250SP, G-05100, G-2050M, and G-017581 (all manufactured by NOF Corporation), and OGSOL (registered trademark) PG-100, CG-500, EG-200, and EG-2 80 (all manufactured by Osaka Gas Chemicals Co., Ltd.), GTR-1800 (all manufactured by Nippon Kayaku Co., Ltd.), EPICLON (registered trademark) 830, 830-S, 835, 840, 840-S, 850, 850-S, 850-LC, HP-820 (all manufactured by DIC Corporation), DENACOL (registered trademark) EX-201, EX-211, EX-212, EX-252, EX-810, EX-811, EX-821, EX-830, EX-832, EX-8 41, EX-850, EX-851, EX-861, EX-920, EX-931, EX-991L, EX-313, EX-314, EX-321, EX-321L, EX-411, EX-421, EX-512, EX-521, EX-612, EX-614, EX-614B, and EX-622 (all manufactured by Nagase ChemteX Corporation), jER (registered trademark) 152, jER 604, jER 630, jER 806, jER 806H, jER 807, and jER 825, Tetrad 827, Tetrad 828, Tetrad 828EL, Tetrad 828US, Tetrad 828XA, Tetrad 834, Tetrad 890, Tetrad 1031S, Tetrad 1032H60, Tetrad 1750, Tetrad YL980, Tetrad YL983U, Tetrad YL6121HA, Tetrad YL6677, Tetrad YL6810, Tetrad YX4000, Tetrad YX4000H, Tetrad YX4000HS, Tetrad YX7700, Tetrad YX8000, Tetrad YX8034, Tetrad YX8800 (all manufactured by Mitsubishi Chemical Corporation), Tetrad (registered trademark) -C, Tetrad -X (all manufactured by Mitsubishi Gas Chemical Company, Inc.),Celoxide (registered trademark) 2021P, Celoxide (registered trademark) 2081, Epolead (registered trademark) GT401, EHPE (registered trademark) 3150, EHPE (registered trademark) 3150CE (all manufactured by Daicel Corporation), Epotohto (registered trademark) YD-115, YD-115CA, YD-127, YD-128, YD-128G, YD-128S, YD-128CA, YD-8125, YD-825GS, YDF-170, YDF-170N, YDF-8170C, YDF-87 0GS, ZX-1059, YH-404, YH-434, YH-434L, YH-513, YH-523, ST-3000 (all manufactured by Nippon Steel Chemical & Material Co., Ltd.), ADEKA RESIN (registered trademark) EP-4100, EP-4100G, EP-4100E, EP-4100TX, EP-4300E, EP-4100, EP-4400, EP-4520S, EP-4530, EP-4901, EP-4901E, EP- 4000, EP-4005, EP-7001, EP-4080E, EPU-6, EPU-7N, EPU-11F, EPU-15F, EPU-1395, EPU-73B, EPU-17, EPU-17T-6, EPR-1415-1, EPR-2000, EPR-2007, ADEKA GLYCILOR (registered trademark) ED-503, ED-503G, ED-506, ED-523T, and ED-505 (all manufactured by ADEKA Corporation) , Sumiepoxy (registered trademark) ELM-434, ELM-434L, ELM-434VL, ELM-100, ELM-100H (all manufactured by Sumitomo Chemical Co., Ltd.), Epolite M-1230, Epolite 40E, Epolite 100E, Epolite 200E, Epolite 400E, Epolite 70P, Epolite 200P, Epolite 400P, Epolite 1500NP, Epolite 1600, Epolite 80MF, Epolite 4000, Epolite 3002(N) (all manufactured by Kyoeisha Chemical Co., Ltd.), and multifunctional epoxy resins such as THI-DE (manufactured by ENEOS Corporation).

[0047] The component (C) may be used alone or in combination of two or more. When the resin composition of the present invention contains the component (C), the content of the component (C) is preferably 5 to 50 parts by mass, more preferably 10 to 30 parts by mass, per 100 parts by mass of the component (A). By setting the content of the component (C) within the above range, it is possible to further improve chemical resistance without impairing the refractive index.

[0048] [Surfactant] The resin composition of the present invention may optionally contain a surfactant for the purpose of improving coatability. Examples of the surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether; polyoxyethylene alkylaryl ethers such as polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl ether; polyoxyethylene / polyoxypropylene block copolymers; sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, and sorbitan tristearate; polyoxyethylene fatty acid esters such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate. Nonionic surfactants such as polyethylene sorbitan fatty acid esters: Eftop (registered trademark) EF301, EF303, EF352 (all manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.), Megafac (registered trademark) F-171, F-173, R-30, R-40, R-40-LM (all manufactured by DIC Corporation), Fluorad FC430, FC431 (all manufactured by Sumitomo 3M Limited), Asahiguard (registered trademark) AG710, Surflon (registered trademark) S-382, Surflon SC1 Fluorine-based surfactants such as Ftergent series (manufactured by Neos Corporation), including FTX-01, SC102, SC103, SC104, SC105, and SC106 (manufactured by AGC Corporation), FTX-206D, FTX-212D, FTX-218, FTX-220D, FTX-230D, FTX-240D, FTX-212P, FTX-220P, FTX-228P, and FTX-240G, and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can be mentioned. These surfactants can be used alone or in combination of two or more.

[0049] When the resin composition of the present invention contains a surfactant, the content of the surfactant is preferably 0.001 to 3 parts by mass, more preferably 0.005 to 1 part by mass, and even more preferably 0.01 to 0.5 parts by mass, relative to 100 parts by mass of the total solid content.

[0050] [Other Additives] The resin composition of the present invention may further contain additives such as a curing aid, an antioxidant, a light stabilizer (HALS), an ultraviolet absorber, a plasticizer, and an adhesion aid, as needed, as long as the effects of the present invention are not impaired.

[0051] [Method for Preparing Resin Composition] The method for preparing the resin composition of the present invention is not particularly limited, but examples include a method in which component (A) and component (B), and optionally component (C) and other components, are mixed to form a homogeneous solution. If necessary, the resulting solution may be filtered using a filter with a pore size of 0.1 μm to 10 μm. The solids concentration of the resin composition thus obtained is typically 1% by mass to 50% by mass, from the viewpoint of coatability onto a substrate.

[0052] [Method of Producing Resin Film] The resin composition of the present invention is applied to a substrate (e.g., a PET film, a TAC film, a semiconductor substrate, a glass substrate, a quartz substrate, a silicon wafer, or a substrate having various metal films or color filters formed on its surface) using an appropriate application method such as a spinner or coater, and then baked using a heating means such as a hot plate or an oven to produce a resin film. The baking conditions are appropriately selected from a baking temperature of 50°C to 300°C and a baking time of 0.1 to 360 minutes. The baking process when producing the resin film may be performed in two or more steps. The thickness of the resin film formed is 0.001 μm to 1,000 μm, preferably 0.01 μm to 100 μm, and more preferably 0.1 μm to 10 μm.

[0053] [Method for Producing Microlenses] A resist is applied to the resin film produced by the above-described [Method for Producing Resin Films], the resist is exposed through a predetermined mask, and if necessary, post-exposure baked (PEB), followed by alkali development, rinsing, and drying to form a resist pattern on the resin film. Examples of light sources that can be used for exposure include g-line, i-line, KrF excimer laser, and ArF excimer laser. The resist pattern is then reflowed by heat treatment to form a lens pattern. Using the lens pattern as an etching mask, the resin film below the lens pattern is etched back, and the shape of the lens pattern is transferred to the resin film to produce a microlens. In this method, when transferring the lens pattern shape to the underlying resin film (microlens resin layer), it is necessary to make the dry etching rate X of the resist pattern and the dry etching rate Y of the microlens resin layer equivalent (X:Y=1:0.8 to 1.2).

[0054] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0055] [Measurement of polystyrene-equivalent weight-average molecular weight of polymer] Apparatus: GPC system manufactured by JASCO Corporation Column: Shodex (registered trademark) KF-804L and KF-803L Column oven: 40°C Flow rate: 1 mL / min Eluent: tetrahydrofuran Sample concentration: 10 mg / mL Sample injection amount: 20 μL Standard substance: monodisperse polystyrene Detector: differential refractometer

[0056] [Production of Monomer] <Monomer Synthesis Example 1> 44.4 g of 2-methoxynaphthalene, 800 mL of tetrahydrofuran, and 184 mL of a hexane solution of n-butyllithium (1.6 mol / L) were added in this order to a flask containing a stirrer in an ice bath and stirred for 1 hour, then cooled to -80°C, and 9.0 g of sulfur was added. The mixture was then stirred at room temperature for 20 hours and subjected to a liquid separation treatment with a saturated aqueous ammonium chloride solution. The resulting organic layer was dehydrated with sodium sulfate and filtered, and the filtrate was evaporated to obtain 53.5 g of 2-methoxy-1-naphthalenethiol as a yellow-green solid.

[0057] Next, 53.5 g of the resulting 2-methoxy-1-naphthalenethiol and 500 mL of chloroform were placed in a flask containing a stirrer, and a solution of 35.7 g of iodine dissolved in 250 mL of methanol was added dropwise and stirred at room temperature for 20 hours. Next, the mixture was separated into 1 M hydrochloric acid, 1 M aqueous sodium hydroxide, and brine, in that order. The resulting organic layer was dehydrated over sodium sulfate and filtered, and the filtrate was evaporated to obtain a yellow oil. This oil was dissolved in 200 mL of chloroform, and then 200 mL of methanol was added to cause crystallization. The resulting solid was dried under reduced pressure at 50°C for 3 hours to obtain a white solid monomer [bis(2-methoxynaphthyl)disulfide].

[0058] Monomer Synthesis Example 2: 22.4 g of 2-methoxybenzenethiol and 300 mL of chloroform were placed in a flask containing a stirrer, and a solution of 20.7 g of iodine dissolved in 150 mL of methanol was added dropwise thereto, followed by stirring at room temperature for 1 hour. Next, 20 mL of a 1 N aqueous solution of sodium thiosulfate was added to remove any remaining iodine, followed by liquid separation treatment with 1 M hydrochloric acid, 1 M aqueous sodium hydroxide, and brine, in that order. The resulting organic layer was dehydrated over sodium sulfate and filtered, and the filtrate was evaporated to obtain a monomer [bis(2-methoxyphenyl)disulfide] as a pale yellow solid.

[0059] Monomer Synthesis Example 3: 25.0 g of 2-naphthalenethiol and 300 mL of chloroform were placed in a flask containing a stirrer, and then a solution of 20.2 g of iodine dissolved in 150 mL of methanol was added dropwise thereto, followed by stirring at room temperature for 2 hours. The resulting precipitate was washed with methanol and dried under reduced pressure at 50°C for 3 hours, yielding a light yellow solid monomer (di-2-naphthyl disulfide).

[0060] Monomer Synthesis Example 4: 16.0 g of sulfur and 497 mL of tetrahydrofuran were placed in a flask equipped with a stirrer and stirred in an ice bath. Next, a solution prepared by dissolving 12.1 g of magnesium and 100 g of 1-bromo-2-methylnaphthalene in 452 mL of tetrahydrofuran was added dropwise in an ice bath and stirred for 1 hour. After stirring at room temperature for 20 hours, the mixture was subjected to a separation treatment with a saturated aqueous ammonium chloride solution. The resulting organic layer was dehydrated with sodium sulfate and filtered, and the filtrate was evaporated to obtain 78.8 g of 2-methyl-1-naphthalenethiol.

[0061] Next, 78.8 g of the resulting 2-methyl-1-naphthalenethiol and 680 mL of chloroform were placed in a flask containing a stirrer, and a solution of 57.4 g of iodine dissolved in 340 mL of methanol was added dropwise and stirred at room temperature for 1 hour. Next, the mixture was separated into 1 M hydrochloric acid, 1 M aqueous sodium hydroxide, and brine, in that order. The resulting organic layer was dehydrated over sodium sulfate and filtered, and the filtrate was evaporated to obtain a yellow oil. This oil was dissolved in 450 mL of chloroform, and then 900 mL of methanol was added to cause crystallization. The resulting solid was dried under reduced pressure at 50°C for 3 hours to obtain a yellow solid monomer [bis(2-methylnaphthyl)disulfide].

[0062] [Production of Polymer or Copolymer] <Polymer Synthesis Example 1> 4.6 g (20 mmol) of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, 2.2 g (20 mmol) of trifluoroacetic acid, and 10 mL of chloroform were placed in a flask containing a stirrer and stirred. 7.6 g (20 mmol) of the monomer obtained in Monomer Synthesis Example 1 was then added and stirred for 40 hours. Next, 20.6 g (180 mmol) of trifluoroacetic acid and 190 mL of chloroform were added to the reaction solution, and the mixture was stirred for an additional 24 hours. The precipitate was removed by filtration, and the filtrate was added dropwise to 2,000 mL of stirred ethanol / 12 N hydrochloric acid (volume ratio: 95 / 5). The precipitate formed by the dropwise addition was collected and washed successively with ethanol, methanol, a 3% by mass aqueous potassium hydroxide solution, and purified water. Next, the obtained precipitate was dissolved again in 100 mL of chloroform and added dropwise to 1,000 mL of stirred methanol / 12N hydrochloric acid = 95 / 5 (volume ratio). The precipitate formed by the dropwise addition was collected, washed in this order with methanol, a 3 mass% potassium hydroxide aqueous solution, and pure water, and then dried at 80°C under reduced pressure to obtain 5.8 g of a polymer of the present invention [poly(2-methoxynaphthylene sulfide)] containing a structural unit represented by the formula (1ca). The polystyrene-equivalent weight average molecular weight M W was 1,300.

[0063] Polymer Synthesis Example 2: 5.8 g of the polymer obtained in Polymer Synthesis Example 1 and 75 mL of dichloromethane were placed in a flask containing a stirrer under a nitrogen atmosphere, and the mixture was cooled to 0°C in an ice bath. 60 mL of a dichloromethane solution of boron tribromide (1 mol / L) was then added dropwise, and the mixture was stirred for 20 hours. 60 mL of pure water was then added dropwise to quench the reaction, and the precipitate was washed with dichloromethane and pure water and then dried at 50°C under reduced pressure, yielding 3.6 g of a polymer of the present invention [poly(2-hydroxynaphthylene sulfide)] containing a structural unit represented by formula (1ba).

[0064] Polymer Synthesis Example 3: 4.6 g (20 mmol) of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, 0.8 g (7 mmol) of trifluoroacetic acid, and 7 mL of chloroform were placed in a flask containing a stirrer and stirred. Then, 5.6 g (20 mmol) of the monomer obtained in Monomer Synthesis Example 2 was added and stirred for 40 hours. Next, 73 mL of chloroform was added to the reaction solution, and the precipitate was removed by filtration. The filtrate was then added dropwise to 800 mL of stirred ethanol / 12 N hydrochloric acid (volume ratio: 95 / 5). The precipitate formed by the addition was collected and washed with ethanol, methanol, a 3% by mass aqueous potassium hydroxide solution, and purified water, followed by redissolution in 80 mL of chloroform and dropwise addition to 800 mL of stirred methanol / 12 N hydrochloric acid (volume ratio: 95 / 5). The precipitate formed by the dropwise addition was collected, washed successively with methanol, a 3% by mass aqueous solution of potassium hydroxide, and pure water, and then dried at 80°C under reduced pressure to obtain 4 g of a polymer [poly(2-methoxyphenylene sulfide)] containing a structural unit represented by the following formula. The polystyrene-equivalent weight average molecular weight M of the obtained polymer was W was 3,000.

[0065] (In the formula, OMe represents a methoxy group.)

[0066] Polymer Synthesis Example 4: 4 g of the polymer obtained in Polymer Synthesis Example 3 and 86 mL of dichloromethane were placed in a flask containing a stirrer under a nitrogen atmosphere, and the mixture was cooled to 0°C in an ice bath. 86 mL of a dichloromethane solution of boron tribromide (1 mol / L) was then added dropwise, and the mixture was stirred for 18 hours. 100 mL of pure water was then added dropwise to quench the reaction, and the precipitate was washed with dichloromethane and pure water and then dried at 50°C under reduced pressure to obtain 3.6 g of a polymer [poly(2-hydroxyphenylene sulfide)] containing a structural unit represented by the following formula:

[0067]

[0068] Polymer Synthesis Example 5: 4.6 g (20 mmol) of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, 2.2 g (20 mmol) of trifluoroacetic acid, and 20 mL of dichloromethane were placed in a flask containing a stirrer and stirred. Then, 2.8 g (10 mmol) of the monomer obtained in Monomer Synthesis Example 2 and 3.2 g (10 mmol) of the monomer obtained in Monomer Synthesis Example 3 were added and stirred for 70 hours. Next, 60 mL of chloroform was added to the reaction solution, and the precipitate was removed by filtration. The filtrate was then added dropwise to 800 mL of stirred ethanol / 12 N hydrochloric acid = 95 / 5 (volume ratio). The precipitate formed by the addition was collected and washed in this order with ethanol, methanol, a 3% by mass aqueous potassium hydroxide solution, and purified water. Then, the precipitate was dissolved again in 80 mL of chloroform and added dropwise to 800 mL of stirred methanol / 12 N hydrochloric acid = 95 / 5 (volume ratio). The precipitate formed by the dropwise addition was collected, washed successively with methanol, a 3% by mass aqueous solution of potassium hydroxide, and pure water, and then dried at 80°C under reduced pressure to obtain 3.0 g of a copolymer of the present invention [poly(2-naphthylene sulfide / 2-methoxyphenylene sulfide)] containing two structural units represented by the following formula. The polystyrene-equivalent weight average molecular weight M of the obtained copolymer was W was 1,300.

[0069] (In the formula, OMe represents a methoxy group.)

[0070] Polymer Synthesis Example 6 In a flask equipped with a stirrer, 2.0 g of the copolymer obtained in Polymer Synthesis Example 5, 0.8 g of sodium hydroxide, 2.0 g of 1-dodecanethiol, and 14 mL of N-methyl-2-pyrrolidone were placed under a nitrogen atmosphere, and the mixture was stirred for 3 hours at 130° C. Next, dilute hydrochloric acid was added to the reaction solution to neutralize it, and the precipitate was washed with pure water and hexane and dried at 80° C. under reduced pressure, thereby obtaining 1.8 g of a copolymer of the present invention [poly(2-naphthylene sulfide / 2-hydroxyphenylene sulfide)] containing two structural units represented by the following formula:

[0071]

[0072] Polymer Synthesis Example 7: 4.6 g (20 mmol) of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, 2.2 g (20 mmol) of trifluoroacetic acid, and 20 mL of dichloromethane were placed in a flask containing a stirrer and stirred. Then, 2.8 g (10 mmol) of the monomer obtained in Monomer Synthesis Example 2 and 3.5 g (10 mmol) of the monomer obtained in Monomer Synthesis Example 4 were added and stirred for 70 hours. Next, 60 mL of chloroform was added to the reaction solution, and the precipitate was removed by filtration. The filtrate was then added dropwise to 800 mL of stirred ethanol / 12 N hydrochloric acid (volume ratio: 95 / 5). The precipitate formed by the addition was collected and washed with ethanol, methanol, a 3% by mass aqueous potassium hydroxide solution, and purified water, followed by redissolution in 80 mL of chloroform and addition dropwise to 800 mL of stirred methanol / 12 N hydrochloric acid (volume ratio: 95 / 5). The precipitate formed by the dropwise addition was collected, washed successively with methanol, a 3% by mass aqueous solution of potassium hydroxide, and pure water, and then dried at 80°C under reduced pressure to obtain 2.0 g of a copolymer of the present invention [poly(2-methyl-1-naphthylene sulfide / 2-methoxyphenylene sulfide)] containing two structural units represented by the following formula. The polystyrene-equivalent weight average molecular weight M of the obtained copolymer was W was 1,700.

[0073] (In the formula, Me represents a methyl group, and OMe represents a methoxy group.)

[0074] Polymer Synthesis Example 8 In a flask equipped with a stirrer, 2.0 g of the polymer obtained in Polymer Synthesis Example 7, 0.8 g of sodium hydroxide, 2.0 g of 1-dodecanethiol, and 14 mL of N-methyl-2-pyrrolidone were placed under a nitrogen atmosphere, and the mixture was stirred for 3 hours at 130° C. Next, dilute hydrochloric acid was added to the reaction solution to neutralize it, and the precipitate was washed with pure water and hexane and dried at 80° C. under reduced pressure, thereby obtaining 1.7 g of a copolymer of the present invention [poly(2-methyl-1-naphthylene sulfide / 2-hydroxyphenylene sulfide)] containing two structural units represented by the following formula:

[0075] (In the formula, Me represents a methyl group.)

[0076] [Preparation of Resin Composition] Example 1 3.6 g of the polymer obtained in Polymer Synthesis Example 2 above as the component (A), 19.7 g of cyclopentanone as the component (B), 0.7 g of triglycidyl isocyanurate as the component (C) (20 parts by mass relative to 100 parts by mass of the component (A)), and 0.001 g of R-40 (manufactured by DIC Corporation) as a surfactant were blended to form a homogeneous solution. The solution was then filtered using a polyethylene microfilter with a pore size of 0.2 μm to obtain a resin composition (solids concentration 18% by mass).

[0077] Comparative Example 1 A resin composition (solid content concentration: 18% by mass) was obtained in the same manner as in Example 1, except that the polymer obtained in Polymer Synthesis Example 4 was used as the polymer not corresponding to the component (A).

[0078] Example 2 A resin composition (solid concentration: 18% by mass) was obtained in the same manner as in Example 1, except that the copolymer obtained in Polymer Synthesis Example 6 was used as the component (A).

[0079] Example 3 A resin composition (solid concentration: 18% by mass) was obtained in the same manner as in Example 1, except that the copolymer obtained in Polymer Synthesis Example 8 was used as the component (A).

[0080] [Evaluation of refractive index] The resin compositions prepared in Examples 1 to 3 and Comparative Example 1 were each applied to a silicon wafer using a spin coater and baked on a hot plate at 100°C for 1 minute. This was then baked at 200°C for 5 minutes to form a resin film with a film thickness of 200 nm. The refractive index of these resin films was measured at a wavelength of 550 nm using a spectroscopic ellipsometer M-2000 (manufactured by J.A. Woollam Japan, Inc.). The results are shown in Table 1.

[0081] [Dry Etching Rate Evaluation] Resist solution THMR-iP1800 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied to a silicon wafer using a spin coater and baked on a hot plate at 90°C for 1.5 minutes, 110°C for 1.5 minutes, and then at 180°C for 1 minute to form a 1 μm-thick resist film. The resist film was dry-etched using a dry etching apparatus RIE-10NR (manufactured by Samco Corporation) (etching gas: CF), and the dry etching rate of the resist film was measured. Next, the resin compositions prepared in Examples 1 to 3 and Comparative Example 1 were each applied to a silicon wafer using a spin coater and baked on a hot plate at 100°C for 1 minute. This was then baked at 200°C for 5 minutes to form a 1 μm-thick resin film, and the dry etching rate was similarly measured. The dry etching rates of the resin films obtained from the resin compositions prepared in Examples 1 to 3 and Comparative Example 1 relative to the resist film were calculated. The results are shown in Table 1.

[0082] [Evaluation of Lens Moldability] Each of the resin compositions prepared in Examples 1 to 3 and Comparative Example 1 was applied to a silicon wafer using a spin coater and baked on a hot plate at 100°C for 1 minute. This was then baked at 200°C for 5 minutes to form a resin film with a thickness of 1.2 μm. Next, a resist solution THMR-iP1800 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied to the resin film using a spin coater and baked on a hot plate at 90°C for 1.5 minutes. This was followed by exposure using an i-line stepper (NSR-2205i12D, NA=0.63, manufactured by Nikon Corporation) through a mask forming a 1 μm x 1 μm square dot pattern, followed by baking at 110°C for 1.5 minutes and then development using a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH). This was further baked at 180°C for 1 minute to form a lens pattern on the resin film, and the width of the lens pattern was measured. Then, using a dry etching apparatus 2300 Versys (registered trademark) Kiyo (registered trademark) 45 (manufactured by Lam Research Co., Ltd.) (etching gas: CHF), the resin film was dry etched using the lens pattern as an etching mask until the lens pattern disappeared, and the width of the formed microlenses was then measured.

[0083] When the width of the microlens after dry etching was larger than or the same as the width of the lens pattern before dry etching, the lens formability was evaluated as "○", and when the width of the microlens after dry etching was smaller than the width of the lens pattern before dry etching, the lens formability was evaluated as "×". The results are shown in Table 1.

[0084]

[0085] It was confirmed that a resin film obtained from a resin composition containing the polynaphthylene sulfide resin of the present invention has a high refractive index of 1.75 or more at a wavelength of 550 nm and also exhibits excellent lens moldability by an etch-back method. From the above results, the polymer and resin composition for optical lenses of the present invention are useful for optical lenses, particularly microlenses.

Claims

1. A polymer containing a structural unit represented by the following formula (1) (excluding the structural unit represented by the following formula (1a)). 【Chemistry 1】 (In the formula, X's each independently represent a methoxy group, an ethoxy group, or a hydroxy group, and n represents an integer of 1 to 6.) 【Chemistry 2】

2. 2. The polymer according to claim 1, wherein n represents 1 in the structural unit represented by formula (1).

3. A method for producing a polymer containing a structural unit represented by the following formula (1) (excluding a structural unit represented by the following formula (1a)), the method comprising a step of oxidatively polymerizing a disulfide monomer represented by the following formula (2) (excluding a disulfide monomer represented by the following formula (2a)) and / or a thiol monomer represented by the following formula (3) (excluding a thiol monomer represented by the following formula (3a)). 【Transformation 3】 (In the formula, X's each independently represent a methyl group, an ethyl group, a methoxy group, an ethoxy group, or a hydroxy group, and n represents an integer of 1 to 6.) 【Chemistry 4】 【Transformation 5】 (In the formula, X and n are defined as in formula (1) above.) 【Transformation 6】

4. A resin composition for an optical lens, comprising: (A) a polymer including a structural unit represented by the following formula (1) (excluding a structural unit represented by the following formula (1a)) and / or a polymer including a structural unit represented by the following formula (4); and (B) an organic solvent. 【Transformation 7】 (In the formula, X's each independently represent a methyl group, an ethyl group, a methoxy group, an ethoxy group, or a hydroxy group, and n represents an integer of 1 to 6.) 【Transformation 8】 【Chemistry 9】

5. 5. The resin composition for optical lenses according to claim 4, wherein the component (B) comprises at least one organic solvent selected from the group consisting of ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, ethyl lactate, n-butyl lactate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, 2-heptanone, cyclopentanone, cyclohexanone, γ-butyrolactone, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, and N-ethyl-2-pyrrolidone.

6. 5. The resin composition for optical lenses according to claim 4, further comprising (C) a polyfunctional epoxy compound.

7. 5. The resin composition for optical lenses according to claim 4, which is used for producing microlenses.

8. A microlens obtained from the resin composition for optical lenses according to claim 7.

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