JP2017088775A - Curable composition and cured product thereof, and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curable composition which can form a self-supporting film with a high refractive index.SOLUTION: A curable composition comprising a curable component represented by formula (1) and metal oxide nanoparticles is prepared (where ring Z is an aromatic hydrocarbon ring, Ris a substituent, Ris an alkylene group, Ris a substituent, X is a sulfur atom or an oxygen atom, k is an integer of 0-4, m is an integer of 1 or more, and n is an integer of 0 or more).SELECTED DRAWING: None

Description

  The present invention relates to a curable composition containing a curable component having a fluorene skeleton and an oxirane ring and / or thiirane ring and a metal oxide, and a cured product and a method for producing the cured product.

  The epoxy resin is cured with various curing agents to form a cured product having excellent mechanical properties, water resistance, chemical resistance, heat resistance, electrical properties, and the like. Therefore, epoxy resins are used in a wide range of fields such as adhesives, paints, laminates, molding materials and casting materials. Conventionally, bisphenol A-type epoxy resins and the like are known as the most commonly used epoxy resins in the industry, but such epoxy resins sometimes have insufficient heat resistance depending on applications. Furthermore, epoxy resins are also used for optical materials and the like. However, recent optical materials require high optical properties, and thus require a high refractive index. Therefore, in order to satisfy such requirements, attempts have been made to introduce a 9,9-bisphenylfluorene skeleton into a resin raw material and to use an episulfide compound instead of an epoxy compound.

  JP-A-2001-181276 (Patent Document 1) discloses an episulfide compound represented by the following formula.

(In the formula, X represents an oxygen atom or a sulfur atom, and at least one is a sulfur atom. R _{1 to} R ₈ represent a hydrogen atom, a halogen atom or an alkyl group having 1 to 4 carbon atoms, and Or different.)

  In this document, as the episulfide compound curing agent, a known epoxy resin curing agent is exemplified, and it is described that polyvalent carboxylic acid anhydrides and polyphenols are preferable. Furthermore, in the examples of this document, methylhexahydrophthalic anhydride or tetrahydrophthalic anhydride is used as a curing agent.

  However, since this episulfide compound is solid and has a high melt viscosity, moldability and handling properties are not sufficient.

  Therefore, as a fluorene skeleton-containing episulfide compound capable of achieving both excellent handling properties, high heat resistance, a high refractive index, and the like, JP2013-124339A (Patent Document 2) is represented by the following formula (1). Episulfide compounds are disclosed.

(In the formula, ring Z is an aromatic hydrocarbon ring, R ¹ is a substituent, R ² is an alkylene group, R ³ is a substituent, k is an integer of 0 to 4, m is an integer of 1 or more, and n is It is an integer greater than or equal to 0).

  In this document, the reactivity with a curing agent can be improved by mixing the episulfide compound with an epoxy resin. As the curing agent, an amine curing agent, a polyaminoamide curing agent, an acid anhydride curing agent, phenol It describes that a system hardening agent can be used.

  However, when combined with an epoxy resin, it becomes difficult to achieve both excellent handling properties and high heat resistance and a high refractive index.

  In particular, in recent optical materials, there is an application that requires a high refractive index, and any of the cured products of Patent Documents 1 and 2 has an insufficient refractive index for such an application.

  On the other hand, “Network Polymer” Vol.27 No.1 (2006), p30-36 (Non-patent Document 1) describes a titanium alkoxide monomer or oligomer (titanium tetraisopropoxide) for hydrogenated bisphenol A type episulfide resin. ) Is used as a curing agent, and a high refractive material is disclosed. This document describes that in the hybrid body, the content of the curing agent can be increased to 10% by weight and the refractive index can be increased to 1.57.

  However, even this hybrid body is not sufficient for applications that require a high refractive index.

JP 2001-181276 A (Claim 1, paragraph [0026], Example) JP 2013-124339 A (Claim 1, paragraphs [0082] [0091], Example)

"Network Polymer" Vol.27 No.1 (2006), p30-36

  Accordingly, an object of the present invention is to provide a curable composition capable of forming a self-supporting film having a high refractive index, a cured product thereof, and a method for producing the cured product.

  Another object of the present invention is to provide a curable composition capable of forming a self-supporting film excellent in transparency, heat resistance, high dielectric property and insulation, and a cured product thereof and a method for producing the cured product.

  Still another object of the present invention is to provide a curable composition capable of forming a self-supporting film excellent in light resistance, a cured product thereof, and a method for producing the cured product.

  As a result of intensive studies to achieve the above-mentioned problems, the inventors have carried out a combination of a curable component having a fluorene skeleton, an oxirane ring and / or a thiirane ring, and metal oxide nanoparticles to achieve high curing. The present invention was completed by finding that a free-standing film having a refractive index can be formed.

  That is, the curable composition of the present invention includes a curable component represented by the following formula (1) and metal oxide nanoparticles.

(In the formula, ring Z is an aromatic hydrocarbon ring, R ¹ is a substituent, R ² is an alkylene group, R ³ is a substituent, X is a sulfur atom or an oxygen atom, k is an integer of 0 to 4, m Is an integer of 1 or more, and n is an integer of 0 or more).

The metal oxide nanoparticles may be periodic table group 4A metal oxide nanoparticles (particularly zirconium oxide nanoparticles). The metal oxide nanoparticles may have an average particle size of 30 nm or less. The weight ratio between the curable component represented by the formula (1) and the metal oxide nanoparticles is about the former / the latter = 70/30 to 5/95 (particularly 30/70 to 10/90). In the formula (1), R ¹ is an alkyl group, k is 0 to 1, R ² is a C _2-4 alkylene group, m is 1 to 10, R ³ is an alkyl group or an aryl group, n is 0 to 4, X may be a sulfur atom.

  The present invention also includes a cured product obtained by curing the curable composition. The refractive index of the cured product may be 1.7 or more. Moreover, the manufacturing method of the hardened | cured material which heat-processes and hardens the said curable composition is also contained in this invention.

  In the present invention, since the (thio) epoxy compound (episulfide compound and / or epoxy compound) having a fluorene skeleton and the metal oxide nanoparticles are thermoset together, a self-supporting film having a high refractive index can be formed. In addition, a self-supporting film excellent in transparency, heat resistance, high dielectric property, and insulation can be formed. Furthermore, when zirconium oxide nanoparticles are used as the metal oxide nanoparticles, the light resistance of the self-supporting film can be improved, and a high refractive index can be imparted to the self-supporting film. Maintain the desired characteristics.

[Curable component represented by formula (1)]
The curable composition of this invention contains the curable component (curable component (1)) represented by Formula (1).

In the formula (1), examples of the aromatic hydrocarbon ring represented by the ring Z include a benzene ring, a condensed polycyclic aromatic hydrocarbon ring [for example, a condensed bicyclic hydrocarbon ring (for example, an indene ring, naphthalene, C _8-20 condensed bicyclic hydrocarbon rings such as rings, preferably C _10-16 condensed bicyclic hydrocarbon rings), condensed tricyclic hydrocarbon rings (eg, anthracene ring, phenanthrene ring, etc.) Bi- to tetracyclic hydrocarbon rings, etc.]. Preferred aromatic hydrocarbon rings include a benzene ring, a naphthalene ring, an anthracene ring and the like, and a benzene ring or a naphthalene ring (particularly a benzene ring) is particularly preferable. The two rings Z substituted at the 9-position of fluorene may be the same or different rings, and may usually be the same ring.

  In addition, the substitution position of the ring Z substituted at the 9th position of fluorene is not particularly limited. For example, the naphthyl group substituted at the 9th position of fluorene may be a 1-naphthyl group, a 2-naphthyl group, or the like. Particularly preferred is a 2-naphthyl group.

In the formula (1), examples of the substituent represented by the group R ¹ include a cyano group, a halogen atom (fluorine atom, chlorine atom, bromine atom, etc.), a hydrocarbon group [eg, alkyl group, aryl Non-reactive substituents (especially non-epoxy substituents) such as a group (C _6-10 aryl group such as a phenyl group), etc., especially a halogen atom, a cyano group or an alkyl group (especially an alkyl group) There are many cases. Examples of the alkyl group include C _1-6 alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, and a t-butyl group (for example, a C _1-4 alkyl group, particularly a methyl group). . In addition, when the group R ¹ is plural (two or more), the groups R ¹ may be different from each other or the same. Further, the groups R ¹ substituted on the two benzene rings constituting the fluorene (or fluorene skeleton) may be the same or different. Further, the bonding position (substitution position) of the group R ¹ with respect to the benzene ring constituting the fluorene is not particularly limited, and examples thereof include the 2nd, 7th, 2nd and 7th positions of the fluorene ring. The preferred substitution number k is 0 to 1, in particular 0. In the two benzene rings constituting fluorene, the number of substitutions k may be the same or different from each other.

In the formula (1), examples of the alkylene group represented by the group R ² include C _2-6 alkylene groups such as ethylene group, propylene group, trimethylene group, 1,2-butanediyl group, and tetramethylene group, Is a C _2-4 alkylene group, more preferably a C _2-3 alkylene group, particularly an ethylene group. When m is 2 or more, the alkylene group may be composed of different alkylene groups, and usually may be composed of the same alkylene group.

The number (addition mole number) m of the oxyalkylene group (group OR ² ) may be an integer of 1 or more, and can be selected from a range of, for example, about 1 to 25 (for example, 1 to 20). 15, preferably 1 to 10, more preferably 1 to 8 (for example, 1 to 5), particularly about 1 to 3 (for example, 1 to 2). Two m's may be the same or different.

  In the formula (1), the sum of two m is, for example, 2 to 30 (for example, 2 to 20), preferably 2 to 15 (for example, 2 to 10), and more preferably 2 to 6 (for example, 2-4). The sum of the two m can adjust the hardness and viscosity of the cured product, and by adjusting to such a range, it is easy to obtain a hard cured product with a high refractive index and high heat resistance. Moreover, the sclerosing | hardenable component (1) which was further excellent in sclerosis | hardenability can be obtained efficiently. Two m's may be the same or different.

  The curable component (1) may be an aggregate of compounds having the same value of m, or an aggregate of compounds having different values of m. In the latter case, the value of m and the sum of the two m are average values (arithmetic average or arithmetic average).

Examples of the substituent R ³ substituted on the ring Z include an alkyl group (for example, a C _1-12 alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, preferably a C _1-8 alkyl group). More preferably a C _1-6 alkyl group), a cycloalkyl group (C _5-8 cycloalkyl group such as a cyclohexyl group, preferably a C _5-6 cycloalkyl group etc.), an aryl group (for example, a phenyl group). , C _6-14 aryl groups such as tolyl group and xylyl group, preferably C _6-10 aryl group, more preferably C _6-8 aryl group, etc., aralkyl groups (C _6-10 such as benzyl group, phenethyl group, etc.) Hydrocarbon groups such as aryl-C _1-4 alkyl groups; alkoxy groups (C _1-8 alkoxy groups such as methoxy groups, preferably C _1-6 A group such as a alkoxy group), a cycloalkoxy group (such as a C _5-10 cycloalkyloxy group), and an aryloxy group (such as a C _6-10 aryloxy group) —OR ⁴ [wherein R ⁴ represents a hydrocarbon group ( The above-exemplified hydrocarbon groups, etc.]; groups such as alkylthio groups (C _1-8 alkylthio groups such as methylthio groups, preferably C _1-6 alkylthio groups) and the like —SR ⁴ (wherein R ⁴ represents An acyl group (C _1-6 acyl group such as acetyl group); alkoxycarbonyl group (C _1-4 alkoxy-carbonyl group such as methoxycarbonyl group); halogen atom (fluorine atom, chlorine atom, bromine) Atom, iodine atom, etc.); hydroxyl group; nitro group; non-epoxy substituents such as cyano group.

Of these, the group R ³ is preferably a hydrocarbon group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an aralkyloxy group, an acyl group, a halogen atom, a nitro group, a cyano group, and the like. R ³ represents a hydrocarbon group [eg, alkyl group (eg, C _1-4 alkyl group)], alkoxy group (C _1-4 alkoxy group, etc.), halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom). Etc.).

In addition, in the same ring Z, when the group R ³ is plural (two or more), the groups R ³ may be different from each other or the same. In the two rings Z, the groups R ³ may be the same or different. The preferred substitution number n may be 0 to 8, preferably 0 to 6 (for example, 1 to 5), more preferably 0 to 4, particularly 0 to 2 (for example, 0 to 1). In the two rings Z, the number of substitutions n may be the same or different from each other.

  The curable component (1) is an episulfide compound (episulfide compound (1)) in which X is a sulfur atom in the formula (1), and an epoxy compound (epoxy compound (1) in which X is an oxygen atom in the formula (1). ). Furthermore, in the formula (1), the curable component (1) may be a compound in which one X is a sulfur atom and the other X is an oxygen atom. The episulfide compound (1) and the epoxy compound (1) And a mixture thereof. Of these, the episulfide compound (1) is preferably contained, and the episulfide compound (1) alone is particularly preferred from the viewpoint that both high optical properties and mechanical properties can be achieved.

  In the formula (1), the following formula

The substitution position of the group represented by the formula [hereinafter simply referred to as “(thio) epoxy group-containing group”] is not particularly limited, and it may be substituted at an appropriate position on the ring Z. For example, when ring Z is a benzene ring, the thioepoxy group-containing group may be substituted at the 3-position or 4-position, particularly 4-position. Further, when the ring Z is a condensed polycyclic aromatic hydrocarbon ring, in particular, a hydrocarbon ring different from the hydrocarbon ring bonded to the 9th position of fluorene (for example, the 5th and 6th positions of the naphthalene ring). Typically, the combination of the (thio) epoxy group-containing group of the naphthalene ring and the substitution position of fluorene is often in the 1,5-position or the 2,6-position. .

  Representative curable components (1) include a compound represented by the following formula (1A) (a compound in which ring Z is a benzene ring in formula (1)), a compound represented by the following formula (1B) (formula And compounds in which ring Z is a naphthalene ring in (1).

(In the formula, n1 represents an integer of 0 to 4, n2 and n3 each represents an integer of 0 to 3, and R ¹ , R ² , R ³ , X, k and m are the same as above).

  Typical curable components (1) include 9,9-bis [(2,3-epithiopropoxy) (poly) alkoxyphenyl] fluorenes (or an episulfide in which X is a sulfur atom in formula (1A)) Compound), 9,9-bis [(2,3-epithiopropoxy) (poly) alkoxynaphthyl] fluorenes (such as an episulfide compound in which X is a sulfur atom in formula (1B)), 9,9-bis [ Glycidyloxy (poly) alkoxyphenyl] fluorenes (or an epoxy compound in which X is an oxygen atom in formula (1A)), 9,9-bis [glycidyloxy (poly) alkoxynaphthyl] fluorenes (in formula (1B), X And an epoxy compound in which is an oxygen atom.

As 9,9-bis [(2,3-epithiopropoxy) (poly) alkoxyphenyl] fluorenes, for example, 9,9-bis {4- [2- (2,3-epithiopropoxy) ethoxy] 9,9-bis [2- (2,3-epi) such as phenyl} fluorene (or 9,9-bis {4- [2- (2,3-thioepoxypropoxy) ethoxy] phenyl} fluorene, the same applies hereinafter) _{thiopropoxy) C 2-4} alkoxyphenyl] fluorene; 9,9-bis {4- [2- (2,3-epithiopropyl propoxy) ethoxy] -3-methylphenyl} fluorene, 9,9-bis {4- [2- (2,3-epithiopropyl propoxy) ethoxy] -3,5-dimethylphenyl} fluorene 9,9-bis [2- (2,3-epithiopropyl _{propoxy) C 2-4} alkoxy - mono Is dialkylphenyl] fluorene; 9,9-bis {4- [2- (2,3-epithiopropoxy) ethoxy] -3-phenylphenyl} fluorene and other 9,9-bis [2- (2,3- Epithiopropoxy) 9,9-bis [(2,3-epithiopropoxy) alkoxyphenyl] fluorenes such as C _2-4 alkoxy-arylphenyl] fluorene (compound in which m is 1 in formula (1A)) In addition, in the formula (1A), a compound in which the sum of two m exceeds 2 is included.

  The 9,9-bis [glycidyloxy (poly) alkoxyphenyl] fluorenes include epoxy compounds corresponding to these episulfide compounds.

Examples of 9,9-bis [(2,3-epithiopropoxy) (poly) alkoxynaphthyl] fluorenes include 9,9-bis {6- [2- (2,3-epithiopropoxy) ethoxy]. 9,9-bis [2- (2,3-), such as 2-naphthyl} fluorene, 9,9-bis {5- [2- (2,3-epithiopropoxy) ethoxy] -1-naphthyl} fluorene Epithiopropoxy) 9,9-bis [(2,3-epithiopropoxy) alkoxynaphthyl] fluorenes such as C _2-4 alkoxynaphthyl] fluorene (compounds in which m is 1 in formula (1B)), these In the formula (1B), a compound in which the sum of two m exceeds 2 is included.

  The 9,9-bis [glycidyloxy (poly) alkoxynaphthyl] fluorenes include epoxy compounds corresponding to these episulfide compounds.

(Method for producing curable component (1))
Of the curing component (1), a commercially available product may be used as the epoxy compound (1), and a conventional method (for example, a method of reacting a compound represented by the following formula (A) with epichlorohydrin). Etc.) may be used.

(In the formula, Z, R ¹ , R ² , R ³ , k, m, and n are the same as above).

  In addition, this epoxy compound (1) can also be manufactured with reference to Unexamined-Japanese-Patent No. 2009-155256.

  On the other hand, the episulfide compound (1) can be produced, for example, by episulfiding the epoxy compound (1).

  When the epoxy compound (1) is produced as described above, in addition to the epoxy compound (1), a multimer of the epoxy compound (1) (compound represented by the following formula (B)) or monofunctional In some cases, a functional epoxy compound (compound represented by the following formula (C)) is produced.

(In the formula, p represents an integer of 1 or more, and Z, R ¹ , R ² , R ³ , k, m, and n are the same as above).

  Then, when the epoxy compound (1) and the epoxy composition containing the multimeric epoxy compound represented by the formula (B) or the monofunctional epoxy compound represented by the formula (C) are episulfided, an episulfide compound ( An episulfide composition comprising 1) is obtained.

  The method for episulfiding the epoxy compound (1) is not particularly limited, but representatively, a method of reacting the epoxy compound (1) with a sulfur-containing compound (thiourea, thiocyanic acid) can be mentioned.

  The sulfur-containing compound is not particularly limited as long as it can be episulfidized, and examples thereof include thiourea, thiocyanic acid or a salt thereof. The sulfur-containing compounds may be used alone or in combination of two or more. Typically, thiourea may be used.

  In addition, the ratio of a sulfur containing compound can be selected according to the ratio of an epoxy group, for example, 2 mol or more (for example, with respect to 1 mol of an epoxy compound (1) (or an epoxy composition containing an epoxy compound (1)) 2.1 to 30 mol), preferably 2.5 to 20 mol, more preferably about 3 to 15 mol (for example, 3 to 10 mol).

  The reaction may be performed in a solvent. Solvents include alcohols (alkyl alcohols such as ethanol, propanol and isopropanol, glycols such as ethylene glycol and propylene glycol), hydrocarbons (aliphatic hydrocarbons such as hexane, cycloaliphatic carbons such as cyclohexane, etc. Hydrogen, aromatic hydrocarbons such as toluene and xylene), halogenated hydrocarbons (methylene chloride, chloroform, etc.), ethers (chain ethers such as dimethyl ether and diethyl ether), cyclic ethers such as dioxane and tetrahydrofuran Etc.), esters (methyl acetate, ethyl acetate, butyl acetate, etc.), ketones (acetone, ethyl methyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), cellosolves, carbitols, propylene glycol Monoalkyl ethers, glycol ether esters (such as ethylene glycol monomethyl ether acetate), amides (such as N, N-dimethylformamide, N, N-dimethylacetamide), sulfoxides (such as dimethyl sulfoxide), nitriles (acetonitrile, Organic solvents such as benzonitrile). The solvent can be used alone or as a mixed solvent.

  The reaction temperature and reaction time can be appropriately selected according to the type of raw material used. The reaction temperature may be, for example, 30 to 120 ° C, preferably 35 to 100 ° C, more preferably about 40 to 70 ° C. The reaction time may be, for example, 30 minutes to 100 hours, usually 1 to 80 hours, preferably about 2 to 60 hours.

  The reaction may be performed while refluxing or may be performed while removing by-products. The reaction may be performed with stirring, may be performed in an inert atmosphere (nitrogen, rare gas, etc.), or may be performed under normal pressure, increased pressure, or reduced pressure.

  The produced compound (episulfide compound (1) or episulfide composition) is separated by a conventional method, for example, separation means such as filtration, concentration, extraction, crystallization, recrystallization, column chromatography, or a combination thereof. It may be separated and purified by means.

[Metal oxide nanoparticles]
The curable composition of the present invention further contains metal oxide nanoparticles as a curable component (polymerization component) in addition to the curable component (1). In the present invention, the nanometer-sized metal oxide particles react with the curing component (1) by heating (polymerization) even if the nano-sized metal oxide particles exhibit a unique behavior in the nano-size, and are not self-supporting. A film can be formed. In addition, since it has excellent reactivity to the curable component (1), it can form a self-supporting film even if it is blended in a large amount with the curable component (1), and the characteristics (high refractive index, etc.) due to the metal oxide are self-supporting. Can be applied to the membrane. In particular, when the Group 4A metal oxide nanoparticles of the periodic table are used as the metal oxide nanoparticles, a high refractive index of 1.7 or more can be realized.

  Examples of the metal oxide constituting the metal oxide nanoparticles include a Group 4A metal oxide (for example, titanium oxide and zirconium oxide), a Group 5A metal oxide (for example, vanadium oxide), and Group 6A of the periodic table. Metal oxide (such as molybdenum oxide and tungsten oxide), Group 7A metal oxide (such as manganese oxide), Group 8 metal oxide (such as nickel oxide and iron oxide), Group 1B metal oxide (such as copper oxide) Group 2B metal oxides (such as zinc oxide), Group 3B metal oxides (such as aluminum oxide and indium oxide), Group 4B metal oxides (such as tin oxide), Group 5B metal oxides (such as antimony oxide) ) And the like. The metal oxide nanoparticles formed of these metal oxides can be used alone or in combination of two or more.

  Of these metal oxide nanoparticles, Group 4A metal oxide nanoparticles and Group 2B metal oxide nanoparticles are preferable, and Group 4A metal oxide nanoparticles are particularly preferable because of the large effect of improving the refractive index. preferable. Furthermore, zirconium oxide nanoparticles (particularly zirconium dioxide nanoparticles) are preferable from the viewpoint that the refractive index can be improved and the light resistance of the free-standing film can be improved.

  The metal oxide nanoparticles may be in the form of a dispersion dispersed in a solvent. Examples of the solvent include water, alcohols (lower alcohols such as methanol, ethanol, isopropanol, butanol, cyclohexanol, etc.), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), esters (methyl acetate, acetic acid, etc.). Ethyl, propyl acetate, butyl acetate, methyl formate, ethyl formate, etc.), ethers (diethyl ether, dioxane, tetrahydrofuran, etc.), aliphatic hydrocarbons (hexane, etc.), alicyclic hydrocarbons (cyclohexane, etc.), aromatic Group hydrocarbons (such as benzene), halogenated carbons (such as dichloromethane and dichloroethane), cellosolves (such as methyl cellosolve and ethyl cellosolve), cellosolve acetates, amides (dimethylformamide, di Such as chill acetamide), and the like. These solvents can be used alone or in combination of two or more. Of these solvents, aliphatic ketones such as methyl ethyl ketone are widely used. The concentration of the metal oxide nanoparticles in the dispersion is, for example, about 0.1 to 50% by weight, preferably about 1 to 40% by weight, and more preferably about 5 to 30% by weight.

  The surface of the metal oxide nanoparticles may be subjected to a conventional surface treatment with a surface treatment agent such as a silane coupling agent from the viewpoint of improving dispersibility in a solvent. From this point, nanoparticles that are not surface-treated are preferable. In the present invention, although the conventional reactive group having reactivity to the (thio) epoxy group is not introduced by the surface treatment agent, it exhibits the unique behavior at the nanosize, or the curability Excellent reactivity with component (1).

  The shape of the metal oxide nanoparticles is not particularly limited, and examples thereof include a spherical shape, an elliptical shape, a polygonal shape (polygonal pyramid shape, a rectangular parallelepiped shape, a rectangular parallelepiped shape, etc.), a plate shape, a rod shape, an indefinite shape, and the like. An isotropic shape such as a substantially spherical shape is preferred.

  The average particle size (number average primary particle size) of the metal oxide nanoparticles may be a nanometer size, but is 50 nm or less (particularly 30 nm or less) from the viewpoint of excellent reactivity with the curable component (1). For example, 1-30 nm, Preferably it is 5-25 nm, More preferably, it is a 10-23 nm (especially 15-20 nm) grade. When the average particle diameter of the metal oxide nanoparticles is too large, the reactivity with the curable component (1) is lowered, and there is a possibility that a self-supporting film cannot be formed.

  In the present invention, the average particle diameter of the metal oxide nanoparticles can be measured based on a conventional method, for example, a scanning electron microscope (SEM) photograph.

  The weight ratio between the curable component (1) and the metal oxide nanoparticles can be selected from the range of the former / the latter = about 90/10/1/99. A cured product (or polymer) with the sex component (1) can be formed, for example 70/30 to 5/95, preferably 50/50 to 7/93 (for example 40/60 to 15/85), more preferably 30/70 to 10/90 (especially 25/75 to 15/85). If the ratio of the metal oxide nanoparticles is too small, the refractive index of the cured film may be lowered, and if it is too large, the mechanical strength of the cured film may be lowered.

[Other curable components]
The curable composition of the present invention may contain other curable components in addition to the curable component (1) and the metal oxide nanoparticles. The other curable component includes a (thio) epoxy compound mixed in the manufacturing process of the curable component (1), a general-purpose epoxy resin, and the like.

  The (thio) epoxy compound is the above-described epoxy compound mixed in the production process of the epoxy compound (1) or a compound obtained by episulfiding the epoxy compound, that is, the (thio) epoxy compound represented by the following formula (2) It may be a (multimeric (thio) epoxy compound) or a (thio) epoxy compound (monofunctional (thio) epoxy compound) represented by the following formula (3). Such multimeric (thio) epoxy compounds and monofunctional (thio) epoxy compounds may reduce curability and physical properties of the cured product, so it is not preferable that they are contained in large quantities. From the viewpoint of improvement or the like, it may be preferable that it is contained in a trace amount.

(In the formula, Z, R ¹ , R ² , R ³ , X, k, m, n, and p are the same as above).

  In the formula (2), p may be, for example, 1 to 10, preferably 1 to 4, more preferably 1 to 3, particularly 1 to 2. Usually, the compound represented by the formula (2) includes at least a compound in which p is 1 in the formula (2). The ratio of the compound in which p is 1 in the formula (2) to the whole compound represented by the formula (2) is, for example, 40 mol% or more (for example, 45 to 100 mol%), preferably 50 mol%. It may be more (for example, 55 to 99 mol%), more preferably 60 mol% or more (for example, 65 to 97 mol%), particularly 70 mol% or more (for example, 75 to 95 mol%).

  The proportion of the compound represented by the formula (2) is 50 mol% or less (for example, 1 to 45 mol%), preferably 40 mol% or less (for example, 2 to 35 mol%) of the entire (thio) epoxy compound, More preferably, it may be 30 mol% or less (for example, 3 to 25 mol%).

  The proportion of the compound represented by formula (3) is 30 mol% or less (for example, 0.5 to 25 mol%), preferably 25 mol% or less (for example, 1 to 22 mol%) of the entire (thio) epoxy compound. ), More preferably 20 mol% or less (for example, 2 to 18 mol%).

  Moreover, the ratio of the total amount of the compound represented by Formula (2) and the compound represented by Formula (3) is 50 mol% or less (for example, 1-45 mol%) of the whole (thio) epoxy compound, Preferably It may be 40 mol% or less (for example, 3 to 35 mol%), more preferably 30 mol% or less (for example, 5 to 25 mol%), and usually 3 to 20 mol% (for example, 5 to 15 mol%). ) Degree.

  The ratio (molar ratio) between the compound represented by the formula (2) and the compound represented by the formula (3) is, for example, the former / the latter = 99/1 to 1/99 (for example, 97/3 to 3/3). 10/90), preferably 95/5 to 15/85 (for example, 93/7 to 20/80), more preferably about 90/10 to 30/70 (for example, 85/15 to 40/60). May be.

  In the present invention, the proportion of the (thio) epoxy compound represented by the formulas (1) to (3) can be determined by measuring the purity (area ratio, area%) by high performance liquid chromatography (HPLC). .

  In the (thio) epoxy compound, the ratio of the compound represented by the formula (2) and the compound represented by the formula (3) can be easily adjusted depending on the production conditions of the epoxy compound used as a raw material. Alternatively, a compound represented by formula (2) or a compound represented by formula (3) may be separately prepared and mixed with a compound represented by formula (1) to prepare a (thio) epoxy composition. it can.

  General-purpose epoxy resins include glycidyl ether type epoxy resins such as bisphenol type epoxy resins (bisphenol A type epoxy resins, bisphenol F type epoxy resins, etc.), phenol novolac type epoxy resins, cresol novolak type epoxy resins, dicyclopentadiene modified Phenol (or cresol) novolac type epoxy resin, biphenyl type epoxy resin, triphenolalkane type epoxy resin (such as triphenolmethane type epoxy resin), phenol aralkyl type epoxy resin, heterocyclic type epoxy resin (epoxy resin containing xanthene unit) ), Stilbene type epoxy resins, condensed ring aromatic hydrocarbon modified epoxy resins (1,6-bis (glycidyloxy) naphthalene, bis (2,7-bis (glycidylo)) Shi) naphthyl) naphthalene ring-containing epoxy resins such as alkanes), glycidyl ester type epoxy resins, and epoxy resins having a fluorene skeleton. These epoxy resins may be used alone or in combination of two or more.

  The proportion of the general-purpose epoxy resin may be 30 mol% or less, for example, 20 mol% or less, preferably 10 mol% or less, more preferably 5 mol% or less (for example, 0 mol% or less). 0.01 to 5 mol%). When there are too many ratios of a general purpose epoxy resin, there exists a possibility that the intensity | strength and refractive index of hardened | cured material may fall.

[Other additives]
The curable composition of the present invention may contain other additives in addition to the curable component and the curing agent. Other additives include, for example, solvents, curing agents (e.g., conventional curing agents for episulfide compounds and epoxy compounds, such as amine curing agents, polyaminoamide curing agents, acid anhydride curing agents, phenol curing agents, etc. ), Curing accelerators, diluents (reactive diluents such as monofunctional (thio) epoxy compounds), colorants, stabilizers (thermal stabilizers, antioxidants, UV absorbers, etc.), fillers, charging An inhibitor, a flame retardant, a flame retardant aid, and the like may be included. You may use another additive individually or in combination of 2 or more types. The ratio of other additives may be 30% by weight or less (for example, 10% by weight or less) with respect to the entire curable composition.

[Hardened product]
The cured product can be obtained by reacting (curing treatment) the curable composition. Such a curing treatment may be performed while molding or molding (or preforming) the curable composition according to the desired shape of the cured product. In addition, as a shape of hardened | cured material, one-dimensional or two-dimensional hardened | cured material, such as a three-dimensional hardened | cured material, a cured film, and a hardened pattern, a point or dot-shaped hardened | cured material, etc. are mentioned. Specifically, the molded body is a product having a desired shape formed from a cured product of the curable composition, a cured film formed from a cured product of the curable composition formed on a substrate ( Coating film) or the like. For example, the curable composition is melted by heating, poured into a predetermined mold and heated to be cured, and a molded body having a desired shape can be obtained. Moreover, a cured film can be formed on a base material by apply | coating a liquid curable composition on a base material, drying, and then heating. The curable composition may be dissolved or dispersed in a solvent to obtain a liquid curable composition. The molding method and the curing conditions are not particularly limited. For example, when molding using a predetermined mold, a molding method by heating and pressurization or a low-temperature molding method called cold press is used.

  The curing treatment can be performed by heating or the like, and may be performed in combination. Usually, the curing treatment is often performed at least by heating.

  In the curing treatment, the heating temperature may be 50 ° C. or higher, for example, 50 to 300 ° C., preferably 80 to 250 ° C., more preferably about 100 to 200 ° C. (especially 150 to 180 ° C.). If the heating temperature is too low, a free-standing film may not be formed.

  The heating time (curing time) may be, for example, about 10 minutes to 24 hours, preferably 30 minutes to 18 hours, and more preferably about 1 to 12 hours (particularly 2 to 8 hours). In order to relieve internal stress due to curing, the curing process may be performed in stages, for example, after a heat treatment at a relatively low temperature, the heat treatment may be performed at a higher temperature.

  The curing process (heat treatment) may be performed in an inert gas atmosphere. By performing in inert gas, coloring of hardened | cured material can be suppressed efficiently. Moreover, you may perform a hardening process under a normal pressure or pressurization.

  Moreover, when forming hardened | cured material in a film form (film form, thin film form), you may form by apply | coating a curable composition to a board | substrate (or base | substrate). The substrate is, for example, an insulating substrate such as resin, glass or ceramic, a semiconductor substrate such as crystalline silicon or amorphous silicon, a conductor substrate such as metal, a conductor layer formed on these substrates, or a composite of these. Things.

  The coating method for forming a coating film (thin film) on the substrate is not particularly limited. For example, spin coating method, roll coating method, bar coating method, slit coating method, gravure coating method, spray coating method, dipping method, screen The printing method etc. can be mentioned.

  The thickness of the coating film (or cured product) is, for example, 0.01 μm to 10 mm, preferably 0.05 μm to 1 mm, more preferably 0.1 to 100 μm (particularly 0.5 to 10 μm) depending on the use of the cured product. ) Degree.

  The curable composition applied to the substrate may be subjected to a drying treatment as necessary. A drying process can be performed using a well-known method. You may perform a drying process under normal pressure, pressurization, or pressure reduction, for example. In addition, the drying treatment may be performed at room temperature, or may be performed by heating with a heating means (hot plate, oven, etc.).

  As described above, the coating film applied to the substrate is subjected to a curing treatment after being dried as necessary. In the curing process, the heating temperature and the heating time can be selected from the same ranges as described above.

  The cured product of the present invention has a high refractive index. Specifically, the cured product may have a refractive index (light source wavelength of 632 nm) of 1.7 or more, for example, 1.73 or more (for example, 1.73 to 1). .9), preferably 1.75 or more (for example, 1.75 to 1.89), more preferably 1.8 or more (for example, 1.8 to 1.88).

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. Various characteristics were measured and evaluated by the following methods.

(GPC (gel permeation chromatography))
Using a high-speed GPC device (“HLC-8320GPC” manufactured by Tosoh Corporation), the sample was dissolved in tetrahydrofuran and measured at a flow rate of 1.0 mL / min, an injection amount of 100 μL, and a temperature of 40 ° C.

(HPLC)
Using high performance liquid chromatography (“L-2000” manufactured by Hitachi High-Technologies Corporation), the sample was diluted 2000 times (acetonitrile), temperature 30 ° C., wavelength 254 nm, flow rate 0.5 mL / min, water / Acetonitrile (weight ratio) = 30/70 was measured for 30 minutes, and then water / acetonitrile (weight ratio) = 0/100 was measured for 30 minutes.

(FT-IR spectrum)
A Fourier transform infrared device (“Spectrum 100” manufactured by PERKIN ELMER) was used as a measurement device, and measurement was performed under the conditions of measurement range: 5000 to 400 cm ⁻¹ , integration count: 4 times, and resolution: 4 cm ⁻¹ .

(NMR)
Using a nuclear magnetic resonance apparatus (“AL-300” manufactured by JEOL Ltd.), 0.02 g of the sample was dissolved in 0.4 ml of deuterated chloroform, and the ¹ H-NMR spectrum of the sample was measured.

(Refractive index)
In Comparative Examples 1 and 2, the measurement was performed at a light source wavelength of 589 nm and a measurement temperature of 25 ° C. using a multiwavelength Abbe refractometer “DR-M2 / 1550” (manufactured by Atago Co., Ltd.).

  In Examples 1 and 2, an ellipsometer ("ESM-1T" manufactured by ULVAC, Inc., rotating analyzer method) is used, and a He-Ne laser having a wavelength of 632 nm is used as the measurement light, and the incident angle is fixed at 70 °. It was measured.

Comparative Example 1
42 g (0.096 mol) of 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene (Osaka Gas Chemical Co., Ltd., hereinafter referred to as BPEF) was added to chloromethyloxirane (special grade, Kishida Chemical Co., Ltd.). The product was dissolved in 88 g (0.96 mol), and 2.0 g of benzyltriethylammonium chloride (special grade, manufactured by Kanto Chemical Co., Inc.) was further added, followed by stirring at 60 ° C. for 1 hour. Next, under reduced pressure (650 mmHg), 30 g of a 40% aqueous sodium hydroxide solution was added dropwise at 45 ° C. over 1.5 hours. Meanwhile, the water produced was removed from the system by azeotropy with chloromethyloxirane, and the distilled chloromethyloxirane was returned to the system. After completion of the dropwise addition, the reaction was continued for another 3 hours. Then, the salt produced | generated by filtration was removed, and also after washing with water, chloromethyl oxirane was distilled off and the viscous liquid was obtained. The obtained viscous liquid was analyzed by HPLC and GPC. As a result, 9,9-bis [4- (2-glycidyloxyethoxy) phenyl] fluorene [or 9,9-bis (4-hydroxyethoxyphenyl) fluorene diene was analyzed. It was confirmed that it was an epoxy compound (epoxy resin) mainly containing glycidyl ether and BPF-2EOG].

  60.46 g of the obtained viscous liquid and 567 g of tetrahydrofuran (THF, manufactured by Nacalai Tesque) were added and dissolved.

  Further, 29.27 g (385 mmol) of thiourea (manufactured by Nacalai Tesque) and 462 g of methanol were added to another 1 L flask to obtain a methanol solution of thiourea.

  A dropping funnel was attached to a 2 L flask, a methanol solution of thiourea was added, and the mixture was added dropwise at room temperature over 0.5 hours. After completion of the dropwise addition, the mixture was heated to 40 to 54 ° C. and reacted for 44 hours. The progress of the reaction was confirmed by HPLC analysis, and the reaction was continued until the peak corresponding to BPF-2EOG disappeared. Thereafter, the reaction solution returned to room temperature is concentrated to about 100 g with a rotary evaporator, and 400 mL of distilled water is added thereto, followed by extraction with ethyl acetate (each extraction with 400 mL and 200 mL each), brine washing, and magnesium sulfate. Dried.

  Thereafter, the solvent was distilled off to obtain a viscous liquid (66.39 g). In the viscous liquid, 5.3% by weight of ethyl acetate remained, and the yield of the solid content was 99.1% by weight. As a result of analyzing the obtained viscous liquid by HPLC, GPC, FT-IR and NMR, an episulfide compound of 9-bis [4- (2-glycidyloxyethoxy) phenyl] fluorene (compound represented by the following formula) was obtained. It was confirmed that the liquid was mainly contained. The purity was 96.2%. Purity was determined by area ratio by HPLC.

¹ H-NMR: δ (ppm) = 7.7 (d, 2H), 7.2-7.4 (m, 6H), 7.1 (d, 4H) 6.8 (d, 4H), 4 .1 (dd, 2H), 3.8 (dd, 2H), 3.7 (dd, 2H), 3.5 (dd, 2H), 3.1 (q, 2H), 2.5 (dd, 2H) 2H), 2.2 (dd, 2H).

  Furthermore, the refractive index (25 degreeC, 589 nm) of the obtained episulfide compound was 1.626.

  After measuring 3 g of this episulfide compound in an aluminum cup and completely dissolving it on a hot plate set at 110 ° C., 1,3-BAC (manufactured by Tokyo Chemical Industry Co., Ltd., “1,3-bisaminocyclohexane” ]) 0.365 g was added and stirred on a hot plate set at 110 ° C. until uniform. This mixture was heat-cured at 40 ° C. for 2 hours, 80 ° C. for 2 hours, and 120 ° C. for 2 hours to obtain a cured product. The heating rate was 2 ° C./min. The obtained cured film had a refractive index of 1.640.

Comparative Example 2
After measuring 3 g of the fluorene episulfide compound obtained in Comparative Example 1 in an aluminum cup and completely dissolving it at 85 ° C., 2E4MZ (“2-ethyl-4-methylimidazole” manufactured by Tokyo Chemical Industry Co., Ltd.) was used as a curing agent. ) 0.0075 g was added and stirred on a hot plate set at 85 ° C. until uniform. This mixture was heat-cured at 40 ° C. for 2 hours, 80 ° C. for 2 hours, and 120 ° C. for 2 hours to obtain a cured product. The heating rate was 2 ° C./min. The obtained cured film had a refractive index of 1.652.

Example 1
2 g of the fluorene episulfide compound obtained in Comparative Example 1 was added to 10 g of zirconium oxide nanoparticle dispersion (manufactured by Solar Co., Ltd., solvent: methyl ethyl ketone, concentration: 30 wt%, average particle size of nanoparticles: 15-20 nm). And mixed. The obtained mixed solution was applied onto a silicone wafer using a spin coater to obtain a 0.5 μm thin film. The solvent was removed by drying at room temperature for 1 day, and cured by heating at 150 ° C. for 2 hours and 180 ° C. for 2 hours to obtain a cured film. The heating rate was 2 ° C./min. The refractive index of the obtained cured film was 1.747. Further, the obtained cured film had a strength as a self-supporting film by polymerization of the fluorene episulfide compound and the zirconium oxide nanoparticles. In addition, the weight ratio of the zirconium oxide nanoparticles (zirconium oxide unit) in the cured film is 60% by weight.

Example 2
A cured film was obtained in the same manner as in Example 1 except that the weight ratio of the zirconium oxide nanoparticles in the cured film was changed to 80% by weight. The refractive index of the obtained cured film was 1.850. Further, the obtained cured film had a strength as a self-supporting film by polymerization of the fluorene episulfide compound and the zirconium oxide nanoparticles.

  The curable composition of the present invention is useful as an insulating material between layers of electronic components, a solder resist for printed circuit boards, a resist material such as a coverlay, etc., color filters, inks (printing inks, etc.), sealants (Semiconductor sealing agents, etc.), paints, coating agents, adhesives, adhesives, underfills, antistatic agents, fillers, conductive members or conductive materials, laminated materials, thermal materials (thermal paper materials, etc.), carbon materials , Insulating materials, foams, pressure sensitive materials, fuel cell membranes, optical materials (transparent materials) [eg lenses (reflow lenses, pickup lenses, micro lenses, etc.), polarizing films, antireflection films, touch panel films, flexible Substrate films, display films, optical fibers, optical waveguides, holograms], and other materials (electric and electronic materials) It is useful as an optical material).

Claims (10)

A curable composition comprising a curable component represented by the following formula (1) and metal oxide nanoparticles.

(In the formula, ring Z is an aromatic hydrocarbon ring, R ¹ is a substituent, R ² is an alkylene group, R ³ is a substituent, X is a sulfur atom or an oxygen atom, k is an integer of 0 to 4, m Is an integer greater than or equal to 1, and n is an integer greater than or equal to 0)   The curable composition according to claim 1, wherein the metal oxide nanoparticles are Group 4A metal oxide nanoparticles of the periodic table.   The curable composition according to claim 1 or 2, wherein the metal oxide nanoparticles are zirconium oxide nanoparticles.   The curable composition according to claim 1, wherein the metal oxide nanoparticles have an average particle size of 30 nm or less.   The curable composition according to any one of claims 1 to 4, wherein a weight ratio of the curable component represented by the formula (1) and the metal oxide nanoparticles is the former / the latter = 70/30 to 5/95. object.   The curable composition according to any one of claims 1 to 5, wherein a weight ratio of the curable component represented by the formula (1) and the metal oxide nanoparticles is the former / the latter = 30/70 to 10/90. object. In Formula (1), R ¹ is an alkyl group, k is 0 to 1, R ² is a C _2-4 alkylene group, m is 1 to 10, R ³ is an alkyl group or an aryl group, n is 0 to 4, X Is a sulfur atom, The curable composition in any one of Claims 1-6.   Hardened | cured material which hardened the curable composition in any one of Claims 1-7.   The cured product according to claim 8, wherein the refractive index is 1.7 or more.   The manufacturing method of the hardened | cured material which heat-processes and cures the curable composition in any one of Claims 1-7.