JP6546023B2 - Curable composition containing episulfide compound, cured product and method for producing the same - Google Patents

Description

  The present invention relates to a curable composition containing an episulfide compound having a fluorene skeleton and an amine-based curing agent, and a cured product and a method for producing the cured product.

  Epoxy resins are cured with various curing agents to form cured products excellent in 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 epoxy resins and the like have been known as the most industrially used epoxy resins, but such epoxy resins sometimes have insufficient heat resistance depending on the application. Furthermore, although epoxy resins are also used for optical materials and the like, recent optical materials require high optical properties, so high refractive index and the like are also required. Therefore, in order to satisfy such requirements, attempts have been made to use an episulfide compound instead of an epoxy compound while introducing a 9,9-bisphenylfluorene skeleton into a resin raw material.

  The episulfide compound represented by following formula is disclosed by Unexamined-Japanese-Patent No. 2001-181276 (patent document 1).

(Wherein, X represents an oxygen atom or a sulfur atom, and at least one is a sulfur atom. Also, R _{1 to} R ₈ represent a hydrogen atom, a halogen atom or an alkyl group having 1 to 4 carbon atoms, and are the same) May or may not differ).

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

  However, since this episulfide compound is solid and has high melt viscosity, its formability and handleability are not sufficient.

  Therefore, as a fluorene skeleton-containing episulfide compound capable of achieving both excellent handling properties and high heat resistance, high refractive index, etc., it is represented by the following formula (1) in JP 2013-124339 A (patent document 2) Episulfide compounds are disclosed.

(Wherein, 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, n is It is an integer of 0 or more).

  This document describes that the reactivity with a curing agent can be improved by mixing the episulfide compound with an epoxy resin, and an amine curing agent is preferable as the curing agent. The proportion of the curing agent may be about 0.1 to 1000 parts by weight, preferably 0.5 to 500 parts by weight, and more preferably about 1 to 300 parts by weight with respect to 100 parts by weight of the curable resin. Have been described. In the example of this document, diaminodiphenylmethane is blended as a curing agent to a curable resin obtained by combining bisglycidyl oxyethoxy phenyl fluorene (epoxy resin) and an episulfide compound of bis glycidyl oxyethoxy phenyl fluorene (episulfide resin) ing. The proportion of the curing agent is such that the amino group is about 1.4 to about 1.8 times the molar number of the total number of moles of the epoxy group and the episulfide group of the cured resin.

  However, even with this episulfide compound, the crosslink density (gel fraction) was low, and the strength of the cured product was not sufficient. Furthermore, when it combines with an epoxy resin, it becomes difficult to make the outstanding handling nature, high heat resistance, high refractive index, etc. make compatible.

JP 2001-181276 A (claim 1, paragraph [0026], an embodiment) JP 2013-124339 A (claim 1, paragraph [0082] [0090] [0091] [0093], an example)

  Therefore, an object of the present invention is to provide a curable composition having a high gel fraction and high strength of a cured product, and a method for producing the cured product and the cured product, even if the curable component is an episulfide compound having a fluorene skeleton. It is to provide.

  Another object of the present invention is to provide a curable composition capable of achieving both excellent handling and high heat resistance, high refractive index, etc., and a method for producing a cured product and a cured product thereof.

  Still another object of the present invention is to provide a curable composition which can be cured even at a relatively low temperature, and a method for producing the cured product and the cured product.

  The inventors of the present invention conducted intensive studies to achieve the above problems, and as a result, a curable component containing an episulfide compound having a fluorene skeleton and an amine curing agent were added to the thioepoxy group (episulfide group) of the curable component. Even if the curable component is an episulfide compound having a fluorene skeleton, the gel fraction can be obtained by adjusting the ratio of nitrogen atoms (amino group, tertiary nitrogen atom, etc.) of the amine curing agent to a specific range and combining them. High, and the strength of the cured product can be improved, thus completing the present invention.

  That is, the curable composition of the present invention is a curable composition containing a curable component containing an episulfide compound represented by the following formula (1) and an amine curing agent, and the thioepoxy group of the curable component is The molar ratio (equivalent ratio) of the amine curing agent to the nitrogen atom is thioepoxy group / nitrogen atom = 100 / 0.1 to 100/65.

(Wherein, 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, n is It is an integer of 0 or more).

  The amine curing agent may be a primary amine (in particular, at least one selected from the group consisting of cyclic aliphatic polyamines, araliphatic polyamines and aromatic polyamines). The molar ratio (equivalent ratio) of the thioepoxy group of the curable component to the amino group of the primary amine is: thioepoxy group / amino group = 100/30 to 100/65 (particularly 100/35 to 100/60) It is an extent.

The proportion of the episulfide compound represented by the formula (1) may be 50 mol% or more with respect to the entire curable component. In the above 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 aryl group, n is 0 to 4 It may be.

  The amine curing agent may be an amine (in particular, imidazoles) containing a tertiary nitrogen atom. The molar ratio (equivalent ratio) of the thioepoxy group of the curable component to the tertiary nitrogen atom of the amine is about thioepoxy group / tertiary nitrogen atom = 100 / 0.3 to 100/5.

  The present invention also includes a cured product obtained by curing the composition. The gel fraction of this cured product may be 90% by weight or more. Further, the present invention also includes a method for producing a cured product in which the composition is heat treated to be cured.

  As described above, the present inventors have found that the proportion of the amine-based curing agent is important for the curing of the episulfide compound, which was extremely unexpected from the common technical knowledge at the time of filing. . That is, since the episulfide compound is a compound having a structure similar to that of the epoxy compound, it was recognized in the common technical knowledge at the time of filing that the curing action is also similar. Therefore, in order to improve the strength of the cured product, as with the epoxy resin, a primary amine-based curing agent is blended so that amino groups react equimolarly to the episulfide group, and amine-based curing It was not assumed to improve the strength of the cured product by adjusting the compounding ratio of the agent. In particular, in the example of Patent Document 2, it is considered that the episulfide resin is less reactive than the epoxy resin, so an amine curing agent is excessively blended, and this is more than the thioepoxy group of the curing component. It was not assumed at all to blend the curing agent at a ratio of a small amount of amino group equivalent. The reason why the gel fraction of the cured product can be improved by a small amount of amine curing agent is not clear, but in the epoxy compound, the epoxy group and the secondary amino group react at an equivalent ratio of 1 to 1, In the episulfide compound, it is possible to estimate that the thioepoxy group further reacts with the formed intermediate (twitter ion), and the thioepoxy group and the secondary amino group finally react at an equivalent ratio of 2 to 1.

  Furthermore, when using an amine containing a tertiary nitrogen atom as the amine-based curing agent, the amount of the amine-based curing agent may act catalytically, which is smaller than that of the primary amine-based curing agent. Even, it was found that a cured product was obtained. This cured product has a high density, and can further improve the heat resistance and the refractive index.

  In the present invention, the ratio of the nitrogen atom of the amine curing agent to the thioepoxy group (episulfide group) of the curing component containing the episulfide compound having a fluorene skeleton and the amine curing agent is within a specific range The gel fraction is high and the strength of the cured product can be improved, even if the curable component is an episulfide compound having a fluorene skeleton, because it is adjusted and combined. Furthermore, it is compatible with excellent handling properties and high heat resistance, high refractive index, and the like. In addition, since curing can be performed even at a relatively low temperature, it is possible to suppress coloring that causes a problem at high temperature curing. In particular, when a primary amine is used as the amine-based curing agent, the properties of the cured product can be easily controlled by the curing agent, and for example, the target mechanical properties and refractive index can be easily adjusted. On the other hand, when an amine containing a tertiary nitrogen atom is used as the amine-based curing agent, excellent properties of the episulfide compound having a fluorene skeleton can be maintained with almost no deterioration, so high heat resistance and optical properties can be realized.

FIG. 1 is a graph showing the relationship between the proportion of the episulfide compound and the refractive index of the cured product in the examples.

[Curable component]
The curable composition of the present invention contains a curable component and an amine curing agent, and the curable component contains the episulfide compound (episulfide compound (1)) represented by the above formula (1).

(Episulfide compound represented by formula (1))
In the above formula (1), as the aromatic hydrocarbon ring represented by ring Z, a benzene ring, a fused polycyclic aromatic hydrocarbon ring [for example, a fused bicyclic hydrocarbon ring (for example, an indene ring, naphthalene, Condensation such as C _8-20 fused bicyclic hydrocarbon ring such as ring, preferably C _10-16 fused bicyclic hydrocarbon ring), fused tricyclic hydrocarbon ring (eg, anthracene ring, phenanthrene ring, etc.) A di- to tetra-cyclic hydrocarbon ring etc.] and the like. As a preferable aromatic hydrocarbon ring, a benzene ring, a naphthalene ring, an anthracene ring and the like can be mentioned, and in particular, a benzene ring or a naphthalene ring (particularly, a benzene ring) is preferable. The two rings Z substituted at position 9 of fluorene may be the same or different rings, and may usually be the same ring.

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

Further, in the formula (1), examples of the substituent represented by the group R ¹ include a cyano group, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom etc.), a hydrocarbon group [eg an alkyl group, an aryl Non-reactive substituents (especially non-epoxy based substituents) such as groups (C _6-10 aryl groups such as phenyl groups) etc., and in particular halogen atoms, cyano groups or alkyl groups (especially alkyl groups) There are many cases. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, _{t-C 1-6} alkyl group such as butyl groups _{(e.g., C 1-4} alkyl group, especially methyl group) can be exemplified such as . In the case group R ¹ is a plurality (2 or more), groups R ¹ may be different from each other, may be identical. Furthermore, the radicals R ¹ to be substituted with two benzene rings constituting the fluorene (or fluorene skeleton) may be the same or may be different. Further, the bonding position (substituting position) of the group R ¹ to the benzene ring constituting fluorene is not particularly limited, and examples thereof include the 2-, 7-, 2- and 7-positions of the fluorene ring. The preferred substitution number k is 0 to 1, in particular 0. In addition, in two benzene rings which comprise fluorene, substitution number k may mutually be the same, and may differ.

In the above formula (1), the alkylene group represented by the group R ² is preferably, for example, a C _2-6 alkylene group such as ethylene group, propylene group, trimethylene group, 1,2-butanediyl group, tetramethylene group, etc. Is a C _2-4 alkylene group, more preferably a C _2-3 alkylene group, particularly an ethylene group. In addition, when m is 2 or more, the alkylene group may be comprised by a different alkylene group, and usually may be comprised by 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, for example, from the range of about 1 to 25 (for example, 1 to 20). It may be about 15, preferably 1 to 10, more preferably 1 to 8 (e.g. 1 to 5), particularly 1 to 3 (e.g. 1 to 2). In addition, two m may be the same or different.

  Also, in the formula (1), the sum of two m's is, for example, 2 to 30 (eg, 2 to 20), preferably 2 to 15 (eg, 2 to 10), more preferably 2 to 6 (eg, 2 to 4). The hardness, viscosity and the like of the cured product can be adjusted by the sum of two m, and by adjusting to such a range, a hard cured product having a high refractive index, high heat resistance, and the like can be easily obtained. Moreover, the episulfide compound which was further excellent in hardenability can be obtained efficiently. In addition, two m may be the same or different.

  The episulfide compound (1) may be a collection of compounds having the same value of m, or may be a collection of compounds having different values of m. In the latter case, the value of m and the sum of the two m is the mean value (arithmetic mean or arithmetic mean).

The substituent R ³ to be substituted on the ring Z is, for example, 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 or a butyl group, preferably a C _1-8 alkyl group More preferably a C _1-6 alkyl group etc., a cycloalkyl group (a C _5-8 cycloalkyl group such as a cyclohexyl group, preferably a C _5-6 cycloalkyl group etc.), an aryl group (eg a phenyl group) , A C _6-14 aryl group such as tolyl group or xylyl group, preferably a C _6-10 aryl group, more preferably a C _6-8 aryl group, etc., C _6-10 such as an aralkyl group (benzyl group, phenethyl group etc. A hydrocarbon group such as aryl-C _1-4 alkyl group etc .; an alkoxy group (C _1-8 alkoxy group such as a methoxy group, preferably C _1-6 A group -OR ⁴ such as a alkoxy group), a cycloalkoxy group (eg, a C _5-10 cycloalkyloxy group), an aryloxy group (eg, a C _6-10 aryloxy group), wherein R ⁴ is a hydrocarbon group said illustrates an example such as a hydrocarbon group)]; _{C 1-8} alkylthio group such as an alkylthio group (methylthio group, preferably the radical -SR ⁴ (wherein like _C such as _1-6 alkylthio group), ^{R 4} is the The same as above; 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) And atoms, iodine atoms, etc.); hydroxyl groups; nitro groups; non-epoxy based substituents such as cyano groups.

Among them, 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, etc. 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).

Note that in the same ring Z, when group R ³ is a plurality (2 or more), groups R ³ may be different from each other, may be identical. Further, in two rings Z, the groups R ³ may be identical or different. Moreover, preferable substitution number n may be 0 to 8, preferably 0 to 6 (for example, 1 to 5), more preferably 0 to 4, and particularly 0 to 2 (for example, 0 to 1). In the two rings Z, the substitution numbers n may be the same as or different from each other.

  In equation (1), the following equation

The substitution position of the group [thioepoxy group-containing group or episulfide group-containing group] represented by is not particularly limited as long as it is substituted at an appropriate position of the ring Z. For example, when the ring Z is a benzene ring, the thioepoxy group-containing group may be substituted at the 3- or 4-position, particularly the 4-position. Also, when the ring Z is a fused polycyclic aromatic hydrocarbon ring, a hydrocarbon ring other than the hydrocarbon ring bonded to the 9-position of fluorene (for example, the 5- and 6-positions of the naphthalene ring) And the like, and typically, the combination of the thioepoxy group-containing group of the naphthalene ring and the substitution position of fluorene is often at the 1,5 position or the 2,6 position.

  Representative episulfide compounds (1) include compounds represented by the following formula (1A) (compounds in which ring Z is a benzene ring in formula (1)), compounds represented by the following formula (1B) (formula (1)) Compounds in which the ring Z is a naphthalene ring in 1) and the like are included.

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

  Representative episulfide compounds (1) include 9,9-bis [(2,3-epithiopropoxy) (poly) alkoxyphenyl] fluorenes (or a compound represented by formula (1A)), 9,9 And -bis [(2,3-epithiopropoxy) (poly) alkoxynaphthyl] fluorenes (such as a compound represented by the formula (1B)) and the like.

Examples of 9,9-bis [(2,3-epithiopropoxy) (poly) alkoxyphenyl] fluorenes include 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, and so forth) Thiopropoxy) C _2-4 alkoxyphenyl] fluorene; 9,9-bis {4- [2- (2,3-epithiopropoxy) 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 - Al 9,9-bis [2- (2,3-epithio) such as 9,9-bis {4- [2- (2,3-epithiopropoxy) ethoxy] -3-phenylphenyl} fluorene; _{propoxy) C 2-4} alkoxy - 9,9-bis such aryl phenyl] fluorene [(2,3-epithiopropyl propoxy) alkoxyphenyl] fluorenes (formula (1A) in the compound m is 1), these In the formula (1A), compounds in which the sum of two m is more than 2 are included.

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 and 9,9-bis {5- [2- (2,3-epithiopropoxy) ethoxy] -1-naphthyl} fluorene 9,9-bis [(2,3-epithiopropoxy) alkoxynaphthyl] fluorenes (compounds in which m is 1 in the formula (1B)) such as epithiopropoxy) _C2-4 alkoxynaphthyl] fluorene, and the like In the formula (1B), a compound in which the sum of two m is more than 2 is included.

  The curable component may contain the episulfide compound (1), but the episulfide compound (1) may be contained as a main component of the curable component in that it can improve the crosslinking density and improve the strength of the cured product. preferable. The proportion of the episulfide compound (1) can be selected from the range of 50 mol% or more (for example, 50 to 100 mol%) with respect to the entire curable component, for example, 60 mol% or more (for example, 65 to 99 mol%) , Preferably 70 mol% or more (e.g. 75 to 98 mol%), more preferably 80 mol% or more (especially 85 to 97 mol%), usually 80 to 95 mol% (e.g. 85 to 93 mol%) ) May be. If the proportion of the episulfide compound (1) is too small, the strength and refractive index of the cured product may be reduced.

(Method for producing episulfide compound (1))
The episulfide compound represented by Formula (1) can be manufactured by, for example, episulfideating the epoxy compound represented by following formula (A).

(Wherein, Z, R ¹ , R ² , R ³ , k, m and n are as defined above).

  A commercial item may be used for the epoxy compound represented by Formula (A), and it manufactured by the conventional method (For example, the method of making the compound represented by a following formula, and epichlorohydrin, etc. react, etc.) May be used.

(Wherein, Z, R ¹ , R ² , R ³ , k, m and n are as defined above).

  In addition, the compound represented by Formula (A) can also be manufactured with reference to Unexamined-Japanese-Patent No. 2009-155256 etc.

  In addition, when manufacturing as mentioned above, the multimer of the epoxy compound represented by Formula (A) other than the epoxy compound represented by Formula (A) (compound represented by following formula (B)) Or, a monofunctional epoxy compound (a compound represented by the following formula (C)) may be 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 as defined above).

  Then, the epoxy composition containing the epoxy compound represented by the formula (A), the multimeric epoxy compound represented by the formula (B), and the monofunctional epoxy compound represented by the formula (C) is episulfided. Then, the episulfide composition mentioned later is obtained.

  The method of episulfideating the epoxy compound represented by the formula (A) is not particularly limited, but typically, the epoxy compound represented by the formula (A) and the sulfur-containing compound (thiourea, thiocyanic acid) The method of making it react is mentioned.

  The sulfur-containing compound is not particularly limited as long as it can be episulfided, 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.

  The proportion of the sulfur-containing compound can be selected according to the proportion of the epoxy group, and is, for example, 2 or more (for example, 2 mol or more) per 1 mol of the epoxy compound (or the composition of the epoxy compound) represented by the formula (A) 2.1 to 30 mol), preferably 2.5 to 20 mol, more preferably 3 to 15 mol (e.g. 3 to 10 mol).

  The reaction may be carried out in a solvent. As the solvent, alcohols (alkyl alcohols such as ethanol, propanol and isopropanol, glycols such as ethylene glycol and propylene glycol), hydrocarbons (aliphatic hydrocarbons such as hexane, alicyclic carbon such as cyclohexane) Hydrogen, aromatic hydrocarbons such as toluene and xylene), halogenated hydrocarbons (such as methylene chloride and chloroform), ethers (such as linear 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 (such as acetonitrile, And organic solvents such as benzonitrile and the like). The solvents 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, about 30 to 120 ° C., preferably 35 to 100 ° C., and more preferably about 40 to 70 ° C. The reaction time may be, for example, about 30 minutes to 100 hours, usually about 1 to 80 hours, and preferably about 2 to 60 hours.

  The reaction may be carried out under reflux or may be carried out while removing by-products. The reaction may be carried out with stirring, may be carried out in an inert atmosphere (nitrogen, noble gas etc.), and may be carried out under normal pressure, under pressure or under reduced pressure.

  In addition, the produced compound (episulfide compound or episulfide composition represented by said Formula (1)) can be obtained by a conventional method, for example, separation means such as filtration, concentration, extraction, crystallization, recrystallization, column chromatography, etc. Alternatively, they may be separated and purified by separation means combining them.

(Other episulfide compounds)
The curable component may contain, in addition to the episulfide compound (1), other episulfide compounds. Other episulfide compounds may be any one as long as it has a thioepoxy group, and is not particularly limited. For example, other episulfide compounds mixed in the production process of episulfide compound (1) may be used. That is, as described above, the episulfide compound is generally obtained by episulfideating the corresponding epoxy compound (the compound represented by the formula (A)), and such an epoxy compound is preferably an epoxy compound The polymer (compound represented by said Formula (B)) and the monofunctional epoxy compound (compound represented by said Formula (C)) which has one epoxy group may be included. Although it is possible to obtain an epoxy compound which does not contain such multimers or monofunctional epoxy compounds depending on the production conditions or purification, an episulfide is made from an epoxy composition containing such multimers or monofunctional epoxy compounds as a raw material In addition to the episulfide compound (1), it contains an episulfide compound (multimeric eposulfide compound) represented by the following formula (2) and an episulfide compound (monofunctional episulfide compound) represented by the following formula (3): An episulfide composition is obtained. Such a multimeric episulfide compound or monofunctional episulfide compound is not preferable to be contained in a large amount because there is a risk of lowering the curability and physical properties of the cured product, etc. If it is, it may be preferable to include it.

(Wherein, Z, R ¹ , R ² , R ³ , k, m, n and p are as defined above).

  In the above formula (2), p may be, for example, about 1 to 10, preferably 1 to 4, more preferably 1 to 3, particularly about 1 to 2. Usually, the compound represented by formula (2) contains at least a compound in which p is 1 in formula (2). The proportion of the compound in which p is 1 in the formula (2) is, for example, 40 mol% or more (for example, 45 to 100 mol%), preferably 50 mol%, based on the whole compound represented by the formula (2) More than (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%) may be used.

  The proportion of the compound represented by the formula (2) is 50 mol% or less (e.g. 1 to 45 mol%), preferably 40 mol% or less (e.g. 2 to 35 mol%) of the entire curable component, more preferably May be 30 mol% or less (e.g., 3 to 25 mol%).

  The proportion of the compound represented by the 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 curable component. More preferably, it may be 20 mol% or less (for example, 2 to 18 mol%).

  Further, the ratio of the total amount of the compound represented by the formula (2) and the compound represented by the formula (3) is 50 mol% or less (for example, 1 to 45 mol%) of the total curable component, preferably 40 mol % Or less (eg, 3 to 35 mol%), more preferably 30 mol% or less (eg, 5 to 25 mol%), and usually about 3 to 20 mol% (eg, 5 to 15 mol%) It may be

  The ratio (molar ratio) of the compound represented by the formula (2) to the compound represented by the formula (3) is, for example, the former / the latter 99/1 to 1/99 (for example, 97/3 to 3/9) 10/90), preferably about 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 episulfide 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 curable component, the ratio of the compound represented by the formula (2) or the compound represented by the formula (3) can be easily adjusted by the production conditions of the epoxy compound as the raw material. Moreover, the compound represented by Formula (2) and the compound represented by Formula (3) can be separately prepared, and it can also be mixed with the compound represented by Formula (1), and an episulfide composition can also be prepared.

  In addition, if the curable component is a small amount, a compound (one-end episulfide compound) whose episulfidation does not proceed completely, for example, one sulfur atom is oxygen in the formula (1) or the formula (2) It may contain a compound or the like that is an atom.

  However, if the proportion of such a compound is too large, desired properties may not be obtained, so the proportion in the curable component is preferably small. The proportion of such a single-end episulfide compound can be easily adjusted by selection of reaction conditions for episulfidation and the like.

(Other curable components)
The curable component is preferably composed of an episulfide compound alone, but may contain another curable component such as an epoxy resin as long as the effects of the present invention are not impaired.

  As epoxy resin, glycidyl ether type epoxy resin, for example, bisphenol type epoxy resin (bisphenol A type epoxy resin, bisphenol F type epoxy resin, etc.), phenol novolac type epoxy resin, cresol novolac type epoxy resin, dicyclopentadiene modified phenol ( Or cresol) novolac epoxy resin, biphenyl epoxy resin, triphenol alkane epoxy resin (triphenol methane epoxy resin etc.), phenol aralkyl epoxy resin, heterocyclic epoxy resin (including epoxy resin containing xanthene unit) Stilbene type epoxy resin, condensed ring aromatic hydrocarbon modified epoxy resin (1,6-bis (glycidyloxy) naphthalene, bis (2,7-bis (glycidyloxy) Futaren) 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.

  In particular, the epoxy resin may be composed of an epoxy resin having at least a fluorene skeleton. The epoxy resin having a fluorene skeleton is preferable because it has a common fluorene skeleton, so it has excellent affinity with the episulfide compound and can easily maintain characteristics such as refractive index and heat resistance. Further, since the episulfide compound is excellent in the curability as described above, mixing with the epoxy resin having a fluorene skeleton can maintain the characteristics derived from the episulfide compound while improving the storage stability. Furthermore, the curing temperature can be efficiently lowered.

  Examples of the epoxy resin having a fluorene skeleton include compounds represented by the following formula (D), and the like.

(Wherein, m1 represents an integer of 0 or 1 and Z, R ¹ , R ² , R ³ , k and n are as defined above).

  In the formula (D), m1 may be 0 or an integer of 1 or more, and in the case of 1 or more, m1 can be selected from the same range as m in the formula (1). The sum of two m1's is also the same as above when m1 is 1 or more. In particular, m1 may be one or more as in the case of m. When the cured product is required to be flexible, an epoxy resin having m1 of 1 or more may be suitably used. Moreover, you may use suitably the epoxy compound represented by Formula (A) used as the raw material of episulfide.

  The proportion of the other curable component (in particular the epoxy resin) may be 30 mol% or less with respect to the entire curable component, for example, 20 mol% or less, preferably 10 mol% or less, more preferably 5 mol % Or less (e.g., 0.01 to 5 mol%). If the proportion of other curable components is too large, the strength and refractive index of the cured product may be reduced.

(Amine curing agent)
As an amine curing agent, a primary amine used as a conventional amine curing agent, an amine containing a tertiary nitrogen atom and the like can be mentioned. Primary amines and amines containing tertiary nitrogen atoms can be selected according to the application, and may be primary amines if necessary to adjust the mechanical properties and refractive index with a curing agent. When high heat resistance and optical properties (such as high refractive index) are required, amines containing tertiary nitrogen atoms may be used.

  Primary amines include linear aliphatic amines, cyclic aliphatic amines, araliphatic amines, aromatic amines and the like. These primary amines can be used alone or in combination of two or more.

  Examples of chain aliphatic amines include chains such as ethylenediamine, 1,3-diaminopropane, dipropylenediamine, 1,4-diaminobutane, hexamethylenediamine, 2,5-dimethylhexamethylenediamine, trimethylhexamethylenediamine and the like Aliphatic (or alkane) diamines; linear aliphatic (or polyalkylene) polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine and the like. These linear aliphatic amines can be used alone or in combination of two or more.

  Examples of cyclic aliphatic amines include mensene diamine, isophorone diamine, diaminodicyclohexylmethane, bis (4-amino-3-methylcyclohexyl) methane, and 1,3-bis (aminomethyl) cyclohexane (1,3-BAC). , Monocyclic aliphatic diamines such as N-aminoethyl piperazine, 3,9-bis (3-aminopropyl) -2,4,8,10-tetraoxaspiro (5.5) undecane; Crosslinks such as norbornane diamine Cyclic polyamine etc. are mentioned.

  As an aromatic aliphatic polyamine, xylylene diamine etc. are mentioned, for example. Examples of the aromatic amine include metaphenylene diamine, diaminodiphenylmethane, diaminodiphenyl sulfone, diaminodiethyldiphenylmethane and the like.

  Among these primary amines, polyamines such as diamines are preferred from the viewpoint of reactivity with the episulfide compound (1), etc. From the viewpoint of the properties of the cured product etc., cyclic aliphatic polyamines, araliphatic polyamines and aromas Group amines are particularly preferred, and from the viewpoints of reactivity, toughness and transparency, cyclic aliphatic diamines (especially monocyclic aliphatic diamines such as 1,3-BAC) are widely used.

  The amine containing a tertiary nitrogen atom includes tertiary amines, imidazoles and the like.

  Examples of tertiary amines include trialkylamines such as triethylamine and tributylamine; aralkyldialkylamines such as benzyldimethylamine; trialkanolamines such as triethanolamine; dialkylalkanolamines such as dimethylaminoethanol; tris (dimethylamino) Dialkylaminophenols such as methyl) phenol; cyclic such as 1,5-diazabicyclo (4.3.0) nonene-5 (DBN), 1,8-diazabicyclo (5.4.0) -undecene-7 (DBU) An amine etc. are mentioned.

The imidazoles include, for example, 2- _C1-18 alkylimidazole such as 2-methylimidazole, 2-ethylimidazole and 2-isopropylimidazole; 2-ethyl-4-methylimidazole and 2-isopropyl-4-methylimidazole 2-C _1-18 alkyl-4-C _1-4 alkylimidazole; 2-arylimidazole such as 2-phenylimidazole; 2-aryl-4-C _1-4 alkyl such as 2-phenyl-4-methylimidazole Imidazole etc. are mentioned.

  The amine containing these tertiary nitrogen atoms may be a derivative (eg, a salt such as phenol salt, phenol novolac salt, carbonate, formate and the like).

The amines containing these tertiary nitrogen atoms can be used alone or in combination of two or more. Among the amines containing these tertiary nitrogen atoms, imidazoles are preferable from the viewpoint of excellent curability, and from the viewpoint of excellent handleability, alkylimidazoles (especially 2-C ₂ such as 2-ethyl-4-methylimidazole) Particular preference is given to _-4 alkyl-4- _C1-3 alkylimidazole).

  The proportion of the amine-based curing agent is such that it forms the thioepoxy group of the curable component (the total thioepoxy group in the case of containing plural types of thioepoxy compounds) and the nitrogen atom of the amine-based curing agent (especially amino group and amine skeleton) It is possible to select from the range of thioepoxy group / nitrogen atom = 100 / 0.1 to 100/65 by the molar ratio (equivalent ratio when the valence of nitrogen atom is “1”) with nitrogen atom), for example 100 / It is about 0.5 to 100/60, preferably about 100/1 to 100/50. If the proportion of the amine-based curing agent is too small, the strength of the cured product may decrease, and if the proportion of the amine-based curing agent is too large, not only the strength of the cured product may decrease but also the refractive index of the cured product may decrease. There is.

  In particular, in the present invention, it is preferable to adjust the ratio with the curable component according to the type of the amine curing agent, and the ratio of the primary amine is determined by the thioepoxy group of the curable component and the primary compound. It is possible to select from the range of thioepoxy group / amino group = 100/30 to 100/65, for example 100/35, in molar ratio with amino group of amine (equivalent ratio when the valence of amino group is “1”). It is about 100/60, preferably 100/40 to 100/55, more preferably 100/45 to 100/55 (particularly 100/45 to 100/50). Thus, in the case of primary amines, a relatively large amount of curing agent is incorporated into the cured product, so that the properties of the curing agent can be reflected in the cured product. Therefore, the type and ratio of the curing agent can be adjusted to control the refractive index and the strength of the cured product. If the ratio of the primary amine is too small, the strength of the cured product may be reduced, and if the ratio of the primary amine is too large, not only the strength of the cured product may be reduced, but also the refractive index of the cured product may be reduced. There is.

  On the other hand, when the ratio of the amine containing a tertiary nitrogen atom is such that the thioepoxy group of the curable component and the tertiary nitrogen atom of the amine (where the valence of the tertiary nitrogen atom is “1”, The equivalent ratio can be selected from the range of thioepoxy group / tertiary nitrogen atom = 100 / 0.1 to 100/10, for example 100 / 0.3 to 100/5, preferably 100 / 0.5 to 100 / And more preferably about 100 / 0.8 to 100/2 (particularly about 100/1 to 100 / 1.5). As described above, in the case of an amine containing a tertiary nitrogen atom, high heat resistance and optical characteristics can be realized because the proportion of the curing agent is small. If the proportion of amines containing tertiary nitrogen atoms is too low, the strength of the cured product is reduced, and if too large, not only the strength of the cured product is reduced, but also the heat resistance and refractive index of the cured product are reduced. There is a risk of

(Other additives)
The curable composition may further contain other additives in addition to the curable component and the amine curing agent. Other additives include other curing agents, curing accelerators, conventional additives and the like.

Other curing agents may be added, for example, when an episulfide compound is used in combination with an epoxy resin. Other curing agents include, for example, polyaminoamide-based curing agents (for example, condensates of polyethylene polyamine and fatty acid), acid anhydride-based curing agents (for example, aliphatics such as dodecenyl succinic anhydride, polyadipic anhydride and the like) Alicyclic acid anhydrides such as tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylhymic anhydride, methylcyclohexenedicarboxylic acid anhydride, etc .; Aromatic acid anhydrides such as phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic acid anhydride, etc., phenolic curing agents {for example, phenol resins (novolaks such as phenol novolac resin, cresol novolac resin, etc.) Resin etc.); having a fluorene skeleton [9, 9-bis (alkyl-hydroxyphenyl) fluorene (eg, 9, 9, 9-bis (hydroxyphenyl) fluorene such as 9, 9-bis (4-hydroxyphenyl) fluorene, etc.) 9,9-Bis (mono or di C _1-4 alkyl- such as 9-bis (4-hydroxy-3-methylphenyl) fluorene, 9,9-bis (4-hydroxy-3,5-dimethylphenyl) fluorene 9,9-bis (mono or di C ₆ ) such as hydroxyphenyl) fluorene), 9,9-bis (aryl-hydroxyphenyl) fluorene (eg, 9,9-bis (4-hydroxy-3-phenylphenyl) fluorene 9,9-Bis (hydroxyphenyl) fluorenes such as _-10 aryl-hydroxyphenyl) fluorene) And phenol compounds such as 9,9-bis (hydroxynaphthyl) fluorene etc.] and the like. These curing agents may be used alone or in combination of two or more.

  The proportion of these curing agents is about 50 mol% or less, preferably 30 mol% or less, and more preferably 10 mol% or less (e.g., 0.01 to 10 mol%) based on the total amount of the curing agent.

  The curing accelerator (or curing catalyst or initiator) can be selected according to the type of curing agent and the like, and, for example, quaternary ammonium salts [for example, the above-mentioned amine curing agents such as tetra-n-butyl ammonium chloride and the like] Quaternary ammonium salts corresponding to tertiary amines exemplified in Section 1], alkali metal or alkaline earth metal alkoxides, phosphines (triphenylphosphine, triethylphosphine, tri-n-butylphosphine etc.), amide compounds (Dimer acid polyamide etc.), Lewis acid complex compound (boron trifluoride ethylamine complex etc.), sulfur compound [eg polysulfide, mercaptan compound (eg. 2-mercaptoethanol, thioglycolic acid ester, trimethylolpropane tris ( β-thiopropionate) ), Thioester compounds (eg, S-, phenyl thioacetate), etc.], boron compounds (phenyl dichloroborane, etc.), condensable organic metal compound (an organic titanium compound, an organoaluminum compound) and the like. In addition, when the amine curing agent is a primary amine, the curing acceleration of the amine (tertiary amine and imidazoles) containing a tertiary nitrogen atom exemplified in the section of the amine curing agent on the primary amine You may use as an agent. The curing accelerators may be used alone or in combination of two or more.

  Although the proportion of the curing accelerator depends on its type, it is, for example, 0.001 to 50 parts by weight, preferably 0.005 to 30 parts by weight, and more preferably 0.01 to 100 parts by weight of the curable component. It may be about 10 parts by weight.

  Conventional additives include, for example, diluents (reactive diluents such as monofunctional epoxy compounds), colorants, stabilizers (heat stabilizers, antioxidants, UV absorbers, etc.), fillers, charging It may contain an inhibitor, a flame retardant, a flame retardant auxiliary and the like. Diluents and additives may be used alone or in combination of two or more.

[Cured product]
The cured product of the present invention is formed by curing the curable composition. In particular, since the episulfide compound (1) of the present invention is excellent in curability, a cured product having high strength can be formed by blending a small amount of an amine-based curing agent.

  A cured product can be obtained by reacting (curing) the curable composition. Such curing may be performed while molding or after molding (or preforming) the curable composition, depending on the desired shape of the cured product. The shape of the cured product may be a three-dimensional cured product, a one-dimensional or two-dimensional cured product such as a cured film or a cured pattern, or a dot or dot cured product. Specifically, the molded product is a product of a desired shape formed of a cured product of the curable composition, a cured film formed of a cured product of the curable composition formed on a substrate And the like. For example, the curable composition can be heated and melted, poured into a predetermined mold and cured by heating to obtain a molded product having a desired shape. A cured film can be formed on a substrate by applying a liquid curable composition on a substrate, drying, and then heating. The curable composition may be dissolved or dispersed in a solvent to obtain a liquid curable composition. Although the molding method and the curing conditions are not particularly limited, for example, in the case of molding using a predetermined mold, a molding method by heat and pressure or a low temperature molding method called cold press is used.

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

  In the curing treatment, the heating temperature may be, for example, 50 to 250 ° C., preferably 60 to 200 ° C., more preferably 80 to 180 ° C. (particularly 90 to 170 ° C.), 160 ° C. or less [eg, 60 to 155 ° C., preferably 150 ° C. or less (eg, 70 to 145 ° C.), more preferably 140 ° C. or less (eg, 90 to 135 ° C.)]. The curable composition of the present invention is excellent in curability and can be cured at a relatively low temperature.

  The heating time (curing time) may be, for example, about 10 minutes to 24 hours, preferably about 30 minutes to 18 hours, and more preferably about 1 to 12 hours (for example, 2 to 8 hours). In addition, in order to relieve the internal stress by hardening, hardening treatment may be performed stepwise, for example, after heat-processing by comparatively low temperature, you may heat-process by higher temperature.

  The curing treatment (heat treatment) may be performed in an inert gas atmosphere. By carrying out in inert gas, coloring of hardened | cured material may be able to be efficiently suppressed. The curing treatment may be performed under normal pressure or under pressure.

  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 may be, 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, or a substrate obtained by forming a conductor layer on these substrates, or a composite of these. The thing is mentioned.

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

  The thickness of the coating (or the cured product) may be, for example, about 0.01 μm to 10 mm, preferably about 0.05 μm to 1 mm, and more preferably about 0.1 to 100 μm, depending on the application of the cured product. In the present invention, a cured product having a relatively large thickness (eg, 1 μm or more (eg, 5 to 1000 μm), preferably 10 μm or more (eg, 15 to 800 μm), more preferably 20 μm or more (eg, 30 to 500 μm)) You can also get

  The curable composition applied to the substrate may be subjected to a drying treatment, if necessary. The drying process can be performed using a known method. The drying treatment may be performed, for example, under normal pressure, under pressure or under reduced pressure, or may be performed by heating with a heating means (hot plate, oven, etc.). Although the temperature at the time of heating varies depending on the solvent used and the drying method, it may be generally 40 to 200 ° C., preferably 50 to 170 ° C., and more preferably about 60 to 150 ° C.

  The coating film applied to the substrate is, as described above, dried as necessary, and then usually cured. In the curing treatment, the heating temperature and the heating time can be selected from the same range as described above.

  The cured product of the present invention has properties such as high refractive index and high heat resistance. The glass transition temperature of the cured product may be 80 ° C. or higher, and when an amine containing a tertiary nitrogen atom such as imidazoles is used as the amine curing agent, it may be 120 ° C. or higher, preferably 120 It may be about -180 ° C, more preferably about 130-150 ° C.

  The refractive index of the cured product (light source wavelength 589 nm) may be 1.64 or more, and is, for example, 1.645 or more when an amine containing a tertiary nitrogen atom such as imidazoles is used as the amine curing agent. It may be about 1.645 to 1.66, more preferably about 1.65 to 1.66.

  Moreover, it is excellent in transparency, for example, light transmittance at wavelengths of 350 nm, 400 nm and 450 nm is 80% or more (for example, 82 to 100%), preferably 85% or more (for example, 88 to 99.9%) More preferably, 90% or more (for example, 92 to 99.5%) of a cured product can also be obtained.

  The cured product of the present invention is strongly crosslinked, and the gel fraction may be, for example, 50% by weight or more (particularly 90% by weight or more), and for example, 50 to 100% by weight, preferably 80 to It may be about 100% by weight, more preferably about 90 to 100% by weight (especially 95 to 100% by weight). In detail, a gel fraction can be measured by the measuring method as described in the Example mentioned later.

  The present invention will be described in more detail based on examples given below, but the present invention is not limited by these examples.

  In addition, the measurement and evaluation of various characteristics were performed by the following methods.

(GPC (gel permeation chromatography))
The sample was dissolved in tetrahydrofuran using a high-speed GPC apparatus (“HLC-8320 GPC” manufactured by Tosoh Corp.), 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 Corp.), the sample dilution ratio 2000 times (acetonitrile), temperature 30 ° C, wavelength 254 nm, flow rate 0.5 mL / min, water / The measurement was performed for 30 minutes with acetonitrile (weight ratio) = 30/70, and then for 30 minutes with water / acetonitrile (weight ratio) = 0/100.

(Gel fraction)
The cured products obtained in Examples and Comparative Examples were stirred in tetrahydrofuran (THF) solvent at 60 ° C. for 12 hours. The cured product was then dried under reduced pressure at 80 ° C. for 1 day. In addition, THF of the extraction solvent was replaced every 2 hours. And gel fraction was computed using following Formula from weight change of hardened | cured material before and behind extraction.

    Gel fraction (%) = (weight of cured product after extraction / weight of cured product before extraction) × 100.

(Tensile strength)
The tensile test was performed using an Instron type tensile tester ("AGS-J" manufactured by Shimadzu Corporation). The measurement conditions were a crosshead speed of 2 mm / min and a maximum load of 100 kg. The size and shape of the test piece conform to JIS-K-7161 and JIS-K-7162, and the test piece size is 1 (1/5) type, the total length is 30 mm, the width is 4 mm, the thickness is 1.5 mm, The length of the parallel portion was 12 mm, the width of the parallel portion was 2 mm, the radius of roundness was 12 mm, the distance between the jaws was 23 mm, and the distance between marking lines was 10 mm.

(Glass-transition temperature)
The glass transition temperature was obtained by measuring tan δ of dynamic viscoelasticity measurement by measuring the peak top. The dynamic viscoelasticity measurement was performed using a non-resonance forced vibration type viscoelasticity measurement / analysis device ("DVE-V4" manufactured by UBM Co., Ltd.). The measurement conditions were performed by adding a sine wave addition in tension mode while changing the temperature. The measurement temperature range was -150 ° C to 250 ° C, the temperature rise rate was 2.0 ° C / min, the frequency was 10 Hz, and the displacement amplitude was 5 μm. Moreover, the test piece was made into the rectangular parallelepiped of thickness 0.4 mm * width 4.0 mm * length 30.0 mm. The storage elastic modulus E ′ and the tan δ value were calculated by the following equations.

(Wherein E ₀ : complex modulus, E ′: storage modulus, E ′ ′: loss modulus, W: test strip width, T: test strip thickness, CD: test strip length, DF: Amplitude of stress signal, DD: amplitude of distortion signal, δ: phase difference).

(Refractive index)
It measured by light source wavelength 589 nm and measurement temperature 25 degreeC using multi-wavelength Abbe refractometer "DR-M2 / 1550" (made by Atago Co., Ltd.).

(Light transmittance)
It measured by the wavelength of 300-800 nm using spectrophotometer "U3000" (made by Hitachi High-Technologies Corp.).

(density)
The measurement of the density was performed based on "the measuring method of the density and specific gravity by the in-liquid weighing method" of JISZ8807.

Example 1
9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene (Osaka Gas Chemical Co., Ltd. product, hereinafter referred to as BPEF) 42 g (0.096 mol) of chloromethyl oxirane (special grade, Kishda 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., Ltd.) was further added, and the mixture was stirred at 60 ° C. for 1 hour. Next, 30 g of a 40% aqueous solution of sodium hydroxide was added dropwise over 1.5 hours at 45 ° C. under reduced pressure (650 mmHg). During the reaction, water produced was removed out of the system by azeotropic distillation with chloromethyl oxirane, and the distilled chloromethyl oxirane was returned to the system. After completion of the addition, the reaction was further continued for 3 hours. Then, after removing the salt produced | generated by filtration and washing with water further, chloromethyl oxirane was distilled off and the viscous liquid was obtained. As a result of analyzing the obtained viscous liquid by HPLC and GPC, it is found that 9,9-bis [4- (2-glycidyloxyethoxy) phenyl] fluorene [or 9,9-bis (4-hydroxyethoxyphenyl) fluorene di] It confirmed that it was an epoxy compound (epoxy resin) which mainly contains glycidyl ether and BPF-2 EOG.

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

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

  The dropping funnel was attached to a 2 L flask, and a methanol solution of thiourea was added and dropped over 0.5 hours at room temperature. 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 performed 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, 400 mL of distilled water is added, extraction with ethyl acetate (extraction once each with 400 mL and 200 mL), brine washing, and magnesium sulfate It was dry.

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

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

  Furthermore, the refractive index (25 ° C., 589 nm) of the obtained episulfide compound was 1.6262.

  After 3.000 g of this episulfide compound was measured in an aluminum cup and completely dissolved on a hot plate set at 110 ° C., 1,3-BAC (“1, 3-bis” manufactured by Tokyo Chemical Industry Co., Ltd.) was used as a curing agent. 0.365 g of aminocyclohexane ") was added and stirred until uniform on a hot plate set at 110 ° C. The molar ratio (equivalent ratio) of the thioepoxy group of the episulfide compound to the amino group of the curing agent was thioepoxy group / amino group = 100/40. The mixture was heat cured at 40 ° C. for 2 hours, at 80 ° C. for 2 hours, and at 120 ° C. for 2 hours to obtain a cured product. The heating rate was 2 ° C./min.

Example 2
A cured product was obtained in the same manner as Example 1, except that the molar ratio (equivalent ratio) of the thioepoxide group of the episulfide compound to the amino group of the curing agent was set to thioepoxy group / amino group = 100/50.

Reference Example 1
A cured product was obtained in the same manner as Example 1, except that the molar ratio (equivalent ratio) of the thioepoxy group of the episulfide compound to the amino group of the curing agent was set to thioepoxy group / amino group = 100/20.

Comparative Example 1
A cured product was obtained in the same manner as Example 1, except that the molar ratio (equivalent ratio) of the thioepoxy group of the episulfide compound to the amino group of the curing agent was set to thioepoxy group / amino group = 100/70.

Comparative example 2
The molar ratio (equivalent ratio) of the epoxy group of the epoxy compound to the amino group of the curing agent is set to epoxy group / amino group = 100/70 using the epoxy compound before episulfide conversion instead of the fluorene episulfide compound A cured product was obtained in the same manner as Example 1 except for the above.

  The gel fractions of the cured products obtained in Examples 1 and 2 and Reference Example 1 and Comparative Examples 1 and 2 and the tensile strength and refractive index of Example 2 were measured. The results are shown in Table 1.

  As apparent from the results of Table 1, the gel fraction of the cured product of the example was high while the gel fraction of the cured product of the comparative example was low.

Example 3
After the fluorene episulfide compound obtained in Example 1 was weighed into a container and completely dissolved at 85 ° C., 2E4MZ (2-ethyl-4-methylimidazole) as a curing accelerator was cured with the thioepoxy group of the episulfide compound. The molar ratio (equivalent ratio) of the agent to the tertiary nitrogen atom was added so that thioepoxy group / tertiary nitrogen atom = 100 / 0.65, and the mixture was stirred at 85 ° C. until uniform. The mixture was heat cured at 40 ° C. for 2 hours, at 80 ° C. for 2 hours, and at 120 ° C. for 2 hours. The temperature rising rate was 2 ° C./min.

Example 4
Similar to Example 3 except that the molar ratio (equivalent ratio) of the thioepoxy group of the episulfide compound to the tertiary nitrogen atom of the curing agent is set to thioepoxy group / tertiary nitrogen atom = 100 / 1.3. A cured product was obtained.

Example 5
Similar to Example 3 except that the molar ratio (equivalent ratio) of the thioepoxide group of the episulfide compound to the tertiary nitrogen atom of the curing agent is set to thioepoxy group / tertiary nitrogen atom = 100 / 2.6. A cured product was obtained.

Example 6
Similar to Example 3 except that the molar ratio (equivalent ratio) of the thioepoxide group of the episulfide compound to the tertiary nitrogen atom of the curing agent is set to thioepoxy group / tertiary nitrogen atom = 100 / 5.2. A cured product was obtained.

Comparative example 3
Instead of the fluorene episulfide compound, the molar ratio (equivalent ratio) of the epoxy group of the epoxy compound to the tertiary nitrogen atom of the curing agent is calculated using the epoxy compound before being episulfideized, epoxy group / tertiary nitrogen atom A cured product was obtained in the same manner as in Example 3 except that the ratio was set to 100 / 0.65.

Comparative example 4
In the same manner as Comparative Example 3 except that the molar ratio (equivalent ratio) of the epoxy group of the epoxy compound to the tertiary nitrogen atom of the curing agent is set to epoxy group / tertiary nitrogen atom = 100 / 1.3. A cured product was obtained.

Comparative example 5
In the same manner as Comparative Example 3 except that the molar ratio (equivalent ratio) of the epoxy group of the epoxy compound to the tertiary nitrogen atom of the curing agent is set to epoxy group / tertiary nitrogen atom = 100 / 2.6. A cured product was obtained.

Comparative example 6
In the same manner as Comparative Example 3 except that the molar ratio (equivalent ratio) of the epoxy group of the epoxy compound to the tertiary nitrogen atom of the curing agent is set to epoxy group / tertiary nitrogen atom = 100 / 5.2. A cured product was obtained.

  The gel fraction, glass transition temperature, refractive index and tensile strength of the cured products obtained in Examples 3 to 6 and Comparative Examples 3 to 6 were measured. The results are shown in Table 2.

  As apparent from the results of Table 2, the refractive index of the cured product of the comparative example was low while the high refractive index of the cured product of the example was shown. In particular, in the examples, when the proportion of the curing agent decreased, the refractive index tended to improve. Furthermore, while the cured product of the example shows a high glass transition temperature at a curing agent amount of 1.3 equivalents, the cured product of the comparative example shows a high glass transition temperature at a curing agent amount of 5.2 equivalents. In order to improve the heat resistance, a large amount of a curing agent is required, and the optical properties are deteriorated.

In addition, the result of having measured the density of the hardened | cured material of Example 1 and 3 shows that the density of the hardened | cured material of Example 3 is 1.255 g / cm to the hardened | cured material of Example 1 being 1.236 g / cm < ³ >. It was cm ³ and the cured product using imidazoles as a curing agent had a higher density.

  Furthermore, in Examples 1 and 3, all or part (30 mol% or 10 mol%) of the episulfide compound was replaced with the epoxy compound to produce a cured product, and the result of measuring the refractive index is shown in FIG. FIG. 1 shows the relationship between the ratio of the episulfide compound on the horizontal axis and the refractive index on the vertical axis, but in any of the examples, the refractive index also improved as the ratio of the episulfide compound increased. Furthermore, Example 3 using imidazole (2E4MZ) showed a higher refractive index than Example 1 using a primary amine (1,3-BAC) as a curing agent.

  The curable composition of the present invention has excellent properties such as high refractive index and high heat resistance. Moreover, since it has a fluorene skeleton, it is excellent also in the dispersibility of additives, such as a pigment.

  Such curable compositions (or cured products) of the present invention are useful as insulating materials between layers of electronic parts, solder resists for printed circuit boards, resist materials such as cover lays, etc., color filters, inks ( Printing ink, etc.) Sealing agent (Semiconductor sealing agent etc.), paint, coating agent, adhesive, adhesive, underfill, antistatic agent, filler, conductive member or conductive material, laminate material, heat sensitive material Materials for paper, etc.), carbon materials, insulating materials, foams, pressure-sensitive materials, films for fuel cells, optical materials (transparent materials) [eg lenses (reflow lenses, pickup lenses, microlenses etc.), polarizing films, reflections Protection film, film for touch panel, film for flexible substrate, film for display, optical fiber, optical waveguide, hologram That the material (electric and electronic materials, optical materials) useful as.

Claims (8)

A curable composition comprising a curable component containing an episulfide compound represented by the following formula (1) and an amine curing agent,
The proportion of the episulfide compound represented by the formula (1) is 50 mol% or more based on the entire curable component,
The amine curing agent is a primary amine, and the molar ratio of the thioepoxy group of the curing component to the amino group of the primary amine is thioepoxy group / amino group = 100/30 to 100/65. Or
The amine-based curing agent is an amine containing a tertiary nitrogen atom, and the molar ratio of the thioepoxy group of the curing component to the tertiary nitrogen atom of the amine-based curing agent is thioepoxy group / tertiary nitrogen atom = 100 / 0.3 to 100/5 in which the curable composition.

(Wherein, 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, n is Is an integer greater than or equal to 0) The amine curing agent is a primary amine, and the molar ratio of the thioepoxy group of the episulfide compound to the amino group of the primary amine is thioepoxy group / amino group = 100/35 to 100/60. The curable composition according to 1 ). The curable composition according to claim 1 or 2 , wherein the primary amine is at least one selected from the group consisting of cycloaliphatic polyamines, araliphatic polyamines and aromatic polyamines. The curable composition of claim 1, wherein the amine containing tertiary nitrogen atoms are imidazoles. 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 aryl group, and n is 0 to 4 The curable composition according to any one of claims 1 to 4 . A cured product obtained by curing the composition according to any one of claims 1 to 5 . The cured product according to claim 6 , which has a gel fraction of 90% by weight or more. The manufacturing method of the hardened | cured material which heat-processes and hardens the composition in any one of Claims 1-5 .

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