JP6013563B2 - Episulfide compound having fluorene skeleton and cured product thereof - Google Patents

Description

  The present invention relates to a novel episulfide compound having a fluorene skeleton (specifically, a 9,9-bis (aryl) fluorene skeleton) and a cured product thereof.

  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.

  On the other hand, a compound having a 9,9-bisphenylfluorene skeleton is known to have an excellent function in heat resistance, and it is also known to use such a compound as an epoxy resin raw material.

  For example, Japanese Patent No. 3659533 (Patent Document 1) discloses an epoxy resin represented by the following formula (1).

(In the formula, each R independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and G represents a glycidyl group.)
The epoxy resin of this document is an epoxy compound having an oxyethylene unit using bisphenoxyethanol fluorene (BPEF) as a raw material among compounds having a 9,9-bisphenylfluorene skeleton, and therefore 9,9-bis (4 -Compared with epoxy compounds derived from phenolic compounds such as glycidyloxyphenyl) fluorene, it has a low viscosity and excellent handling properties. However, the introduction of oxyethylene units reduces heat resistance, refractive index, and the like as compared to BPFG.

  Therefore, development of a material having excellent handling properties is desired without impairing excellent functions such as high heat resistance and high refractive index.

  JP-A-2001-181276 (Patent Document 2) 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 May be different)
In the examples of this document, 9,9-bisphenolfluorene type epoxy resin is used, and in the above formula, X is a sulfur atom, and R _{1 to} R ₈ are all hydrogen atoms. A compound obtained by mixing this aromatic episulfide compound with tetra-n-butylammonium chloride and S-phenylthioacetate was heated to produce a self-cured product having a refractive index of 1.678 at 25 ° C. It is described that it was obtained.

  As described above, the episulfide compound of the above formula is a compound obtained by episulfiding an epoxy compound derived from a compound having a phenolic hydroxyl group such as 9,9-bis (4-glycidyloxyphenyl) fluorene. In this document, episulfidation of an epoxy compound derived from a fluorene compound having an oxyethylene unit is not assumed. Moreover, since said episulfide compound is solid and melt viscosity is also high, a moldability and handling property are not enough.

Japanese Patent No. 3659533 (Claim 1) JP 2001-181276 A (Claim 1, Example)

  Accordingly, an object of the present invention is to provide a fluorene skeleton-containing episulfide compound and a cured product thereof that can achieve both excellent characteristics such as high heat resistance and high refractive index and excellent handling properties.

  Another object of the present invention is to provide a fluorene skeleton-containing episulfide compound excellent in curability and a cured product thereof.

  Still another object of the present invention is to provide a fluorene skeleton-containing episulfide compound which can be cured even at a relatively low temperature, and a cured product thereof.

  Another object of the present invention is to provide a fluorene skeleton-containing episulfide compound capable of forming a cured product having excellent transparency while having excellent properties such as high heat resistance and a high refractive index, and a cured product thereof. It is in.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have found that 9,9-bis (glycidyloxy (poly) alkoxyphenyl) fluorene, among other epoxy compounds having a 9,9-bisarylfluorene skeleton, etc. A compound obtained by episulfiding (or thioepoxidizing or epithiolating) an epoxy compound having an oxyalkylene unit has a good balance between excellent properties such as high heat resistance and high refractive index and excellent handling properties, and Surprisingly, such a novel episulfide compound is cured to such an extent that it can be cured alone without using not only a curing agent but also a curing catalyst and an initiator as envisaged in Patent Document 2. The present invention has been completed by finding that it has excellent properties and can be cured even at relatively low temperatures.

  That is, the episulfide compound (thioepoxy compound) of the present invention is represented by the following formula (1).

(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 of 0 or more.)
In the above formula (1), Z may be, for example, a benzene ring or a naphthalene ring, and the total of two m may be, for example, about 2 to 20. Moreover, in said Formula (1), 2-6 or 7-16 may be sufficient as the sum total of two m.

  The episulfide compound may be curable alone.

  The present invention also includes a cured product obtained by curing the curable component composed of the episulfide compound. The curable component may be a curable component that does not contain a curing agent and a curing accelerator. The curable component may further include another curable resin composed of an epoxy resin (particularly, an epoxy resin having a fluorene skeleton).

  The cured product of the present invention is excellent in transparency. For example, the light transmittance at wavelengths of 350 nm, 400 nm, and 450 nm may be 90% or more.

  Such a cured product of the present invention can be produced by heating and curing the curable component. In particular, in such a method, heat treatment may be performed at a relatively low temperature (for example, 160 ° C. or lower).

  In the present specification, the “class” such as a compound name includes a case of “having no substituent” and a case of “having a substituent”, and “may have a substituent”. May mean.

  Although the novel episulfide compound of the present invention has excellent properties (high heat resistance, high refractive index, low elastic modulus, etc.), it has excellent solvent solubility and low viscosity properties. It is possible to achieve both excellent characteristics and excellent handling properties. Moreover, such episulfide compounds are excellent in curability. This can also be confirmed by the fact that it can be cured alone without using a curing agent or a curing catalyst. Therefore, not only when used alone, but also when a curing catalyst or the like is used, it can be efficiently cured, and the excellent properties as described above can be efficiently imparted to the cured product. In particular, the novel episulfide compound of the present invention can be cured (or molded) even at relatively low temperatures. The episulfide compound tends to be colored at high temperatures because of the proximity effect of sulfur. Further, when cured at a high temperature, hydrogen sulfide is generated by decomposition. Also from these viewpoints, the episulfide compound of the present invention that can be cured at a relatively low temperature (and excellent in curability) without impairing curability and excellent functions (high refractive index, etc.) has extremely usefulness. high.

  Furthermore, in the present invention, it has excellent properties such as high heat resistance, high refractive index, low elastic modulus, etc. in relation to excellent curability and low temperature curable properties, etc., and excellent transparency. The cured product can be formed.

  Furthermore, in the present invention, by adjusting the amount of oxyalkylene units, a cured product having a desired hardness can be obtained while having properties such as a high refractive index and high heat resistance. Therefore, in this invention, hard or soft hardened | cured material can be obtained according to a use, and hardened | cured material which has adhesiveness can also be obtained.

[Episulfide compounds]
(Episulfide compound represented by formula (1))
The episulfide compound of the present invention is represented by the following formula (1).

(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 of 0 or more.)
In the above 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 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 (particularly 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 k 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. Further, the two groups R ² may be the same or different, and may usually be the same.

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). 18, preferably 1 to 15, more preferably 1 to 12 (for example, 1 to 10), particularly about 1 to 8 (for example, 1 to 7). 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 25), preferably 2 to 20 (for example, 2 to 18), and more preferably 2 to 16 (for example, 2-14).

  In addition, hardness, a viscosity, etc. in hardened | cured material change with the sum total of two m. Therefore, the sum of the two m values may be adjusted according to desired characteristics. For example, in the formula (1), the sum of two m may be made relatively small (for example, 2 to 6, preferably 2 to 5, more preferably 2 to 4, particularly about 2 to 3). Thus, when the sum of two m is made small, it is easy to obtain a hard cured product with a high refractive index and high heat resistance. In addition, an episulfide compound having further excellent curability can be obtained efficiently.

  On the other hand, in the formula (1), the sum of two m is relatively large [for example, 6 or more (for example, 6.5 to 20), preferably 7 to 18 (for example, 7 to 16), and more preferably 8 to 14 (for example, 8.5 to 12), particularly 9 to 12 (for example, about 9.5 to 11.5)]. When the sum of the two m is increased in this way, it is easy to obtain a cured product having softness or flexibility while having a relatively high refractive index and heat resistance, and obtaining a cured product having tackiness (tack). You can also. Moreover, when the total of two m is enlarged, it will be easy to obtain the episulfide compound which is much lower viscosity and was excellent in handling property.

  The episulfide compound represented by the formula (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 and the like). A group —SR ⁴ such as an alkylthio group (C _1-8 alkylthio group such as a methylthio group, preferably a C _1-6 alkylthio group); wherein R ⁴ is as defined above; an acyl group (acetyl group) C _1-6 acyl group such as); alkoxycarbonyl group (such as C _1-4 alkoxy-carbonyl group such as methoxycarbonyl group); halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom etc.); hydroxyl group A non-epoxy substituent such as a nitro group, a cyano group, and a substituted amino group (for example, a dialkylamino group such as a dimethylamino 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, a substituted amino group, and the like. Particularly preferred groups R ³ are hydrocarbon groups [eg alkyl groups (eg C _1-4 alkyl groups)], alkoxy groups (C _1-4 alkoxy groups etc.), halogen atoms (fluorine atoms, chlorine atoms, bromines). Atoms, iodine atoms, etc.).

In the same ring Z, when n 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.

  In the formula (1), the following formula

The substitution position of the group represented by [thioepoxy group-containing group or episulfide group-containing group] is not particularly limited, and may be substituted at an appropriate position on 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). Etc.), and typically, the combination of the thioepoxy group-containing group of the naphthalene ring and the substitution position of fluorene is often the 1,5-position or the 2,6-position.

  Representative episulfide compounds 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) (in formula (1)) A compound in which the ring Z is a naphthalene ring).

(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 , k and m are the same as described above.)
Typical episulfide compounds represented by the formula (1) include 9,9-bis [(2,3-epithiopropoxy) (poly) alkoxyphenyl] fluorenes (or the formula (1A)). Compound), 9,9-bis [(2,3-epithiopropoxy) (poly) alkoxynaphthyl] fluorenes (such as a compound represented by the formula (1B)), and the like.

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 - Al 9,9-bis [2- (2,3-epithio) such as 9,9-bis {4- [2- (2,3-epithiopropoxy) ethoxy] -3-phenylphenyl} fluorene Propoxy) 9,9-bis [(2,3-epithiopropoxy) alkoxyphenyl] fluorenes such as C _2-4 alkoxy-arylphenyl] fluorene (compounds wherein m is 1 in formula (1A)), these In the formula (1A), a compound in which the sum of two m exceeds 2 is 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, 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.

(Complex episulfide compound)
As will be described later, the episulfide compound is usually obtained by episulfiding a corresponding epoxy compound (a compound represented by the formula (A) described later). Body (compound represented by formula (B) described later) and a monofunctional epoxy compound having one epoxy group (compound represented by formula (C) described later) may be included. Epoxy compounds that do not contain such multimers and monofunctional epoxy compounds can be obtained by manufacturing conditions and purification, but composite epoxy compounds containing such multimers and monofunctional epoxy compounds (epoxy compositions) ) and when episulfide as a raw material, in addition to the episulfide compound represented by the formula (1), tables in episulfide compound represented by the following formula (2) (multimer et pin sulfide compound) and formula (3) The composite episulfide compound (episulfide composition) containing the episulfide compound (monofunctional episulfide compound) is obtained.

  Such multimeric episulfide compounds and monofunctional episulfide compounds may reduce curability and physical properties of the cured product, so it is not preferable to be included in a large amount, but from the viewpoint of improving handling properties, In other words, it may be preferable that it is included. Therefore, the episulfide compound includes an episulfide compound represented by the above formula (1), an episulfide compound represented by the formula (2) (multimeric compound) and / or an episulfide compound represented by the formula (3) (monofunctional). And a composite episulfide compound (episulfide composition) containing an episulfide compound).

(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 described above.)
In the above formula (2), n 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 n is 1 in the formula (2). The ratio of the compound in which n is 1 in the formula (2) to the whole compound represented by the formula (2) is, for example, 40% or more (for example, 45 to 100%), preferably 50% or more (for example, 55 to 99%), more preferably 60% or more (for example, 65 to 97%), particularly 70% or more (for example, 75 to 95%).

  In the composite episulfide compound, the proportion of the episulfide compound represented by the formula (1) can be selected from the range of 50% or more (for example, 50 to 99%) of the entire composite episulfide compound depending on the application and the like, for example, 55% Or more (for example, 55 to 98%), preferably 60% or more (for example, 60 to 97%), more preferably 65% or more (for example, 65 to 96%), particularly 70% or more (for example, 70 to 95%) ), Particularly preferably 75% or more (for example, 75 to 94%), and usually 80% or more (for example, 80 to 95%, preferably 85 to 93%).

  In the composite episulfide compound, the proportion of the compound represented by the formula (2) is 50% or less (for example, 1 to 45%), preferably 40% or less (for example, 2 to 35%) of the entire composite episulfide compound, Preferably, it may be 30% or less (for example, 3 to 25%).

  In the composite episulfide compound, the proportion of the compound represented by the formula (3) is 30% or less (for example, 0.5 to 25%), preferably 25% or less (for example, 1 to 22%) of the entire composite episulfide compound. More preferably, it may be 20% or less (for example, 2 to 18%).

  In the composite episulfide compound, the ratio of the total amount of the compound represented by the formula (2) and the compound represented by the formula (3) is 50% or less (for example, 1 to 45%) of the entire composite episulfide compound, preferably May be 40% or less (for example, 3 to 35%), more preferably 30% or less (for example, 5 to 25%), and usually about 3 to 20% (for example, 5 to 15%). Also good.

  In the composite episulfide compound, the ratio of 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). 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). There may be.

  In the composite episulfide compound, the ratio of the compounds represented by formulas (1) to (3) can be determined by measuring the purity (area ratio, area%) by high performance liquid chromatography (HPLC). .

  In the composite episulfide 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 as a raw material. Moreover, the compound represented by Formula (2) and the compound represented by Formula (3) can be separately prepared and mixed with the compound represented by Formula (1) to prepare a composite episulfide compound.

  Note that the compound episulfide compound is a compound in which episulfidation has not completely progressed (one-end episulfide compound), for example, in the formula (1) or the formula (2), if one sulfur atom is oxygen. It may contain compounds that are atoms.

  However, since the desired characteristics may not be obtained if the proportion of such a compound is too large, the proportion in the composite episulfide compound is preferably small. In addition, the ratio of such a one-terminal episulfide compound can be easily adjusted by selecting reaction conditions for episulfation.

(Production method)
The episulfide compound represented by the formula (1) can be produced, for example, by episulfiding an epoxy compound represented by the following formula (A).

(In the formula, Z, R ¹ , R ² , R ³ , k, m, and n are the same as described above.)
As the epoxy compound represented by the formula (A), a commercially available product may be used, which is produced by a conventional method (for example, a method of reacting a compound represented by the following formula with epichlorohydrin). May be used.

(In the formula, Z, R ¹ , R ² , R ³ , k, m, and n are the same as described 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, in addition to the epoxy compound represented by the formula (A), a multimer of the epoxy compound represented by the formula (A) (compound represented by the following formula (B)) Alternatively, a monofunctional epoxy compound (a compound represented by the following formula (C)) may be generated.

(In the formula, Z, R ¹ , R ² , R ³ , k, m, n, and p are the same as above.)
And the epoxy compound (composite epoxy) containing the epoxy compound represented by Formula (A), the multimer epoxy compound represented by the said Formula (B), and the monofunctional epoxy compound represented by Formula (C) When the compound) is episulfided, a composite episulfide compound as described above is obtained.

  The method for episulfiding the epoxy compound represented by the formula (2) is not particularly limited, but typically, the epoxy compound represented by the formula (2) and a sulfur-containing compound (thiourea, thiocyanic acid) The method of making this react is 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, 2) with respect to 1 mol of the epoxy compound (or composite epoxy compound) represented by the formula (A). 0.1 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 or composite episulfide compound represented by the formula (1)) can be separated by a conventional method such as filtration, concentration, extraction, crystallization, recrystallization, column chromatography and the like. These may be separated and purified by a separation means combining these.

[Cured product]
The cured product of the present invention is formed by curing a curable component composed of the episulfide compound (including a complex episulfide compound). In particular, since the episulfide compound of the present invention is excellent in curability, it can be cured alone. Therefore, even if the curable component does not contain a curing agent or a curing catalyst, a cured product can be formed.

  Since the curable resin constituting the curable component (curable resin component) can be singly cured as described above, it may be composed only of an episulfide compound, and depending on the use and desired characteristics, You may comprise with another curable resin.

  Examples of other curable resins include epoxy resins. Examples of the epoxy resin include glycidyl ether type epoxy resins such as bisphenol type epoxy resins (bisphenol A type epoxy resin, bisphenol F type epoxy resin, etc.), phenol novolac type epoxy resins, cresol novolac type epoxy resins, dicyclopentadiene modified phenols ( 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 (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.

  By mixing with the epoxy resin, the reactivity with the curing agent can be improved or improved. Therefore, a wide range of curing agents including acid anhydride curing agents can be used.

  In particular, the epoxy resin may be composed of an epoxy resin having at least a fluorene skeleton. Epoxy resins having a fluorene skeleton are suitable because they have a common fluorene skeleton, and are excellent in affinity with an episulfide compound, and easily maintain properties such as refractive index and heat resistance. Moreover, since the episulfide compound is excellent in curability as described above, by mixing with an epoxy resin having a fluorene skeleton, the characteristics derived from the episulfide compound can be maintained while improving the storage stability. Furthermore, the curing temperature can be lowered efficiently.

  Examples of the epoxy resin having a fluorene skeleton include a compound represented by the following formula (D).

(In the formula, m1 represents 0 or an integer of 1 or more, and Z, R ¹ , R ² , R ³ , k, and n are the same as described above.)
In the above formula (D), m1 may be 0 or an integer of 1 or more, and when it is 1 or more, it can be selected from the same range as m in the formula (1). The sum of the two m1s is the same as described above when m1 is 1 or more. In particular, m1 may be 1 or more like m. When the cured product is required to have flexibility or the like, an epoxy resin having m 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.

  When an episulfide compound is combined with another curable resin (especially an epoxy resin), these ratios can be selected in consideration of handling properties, curability, desired characteristics, etc. For example, the former / the latter (weight ratio) Can be selected from the range of about 99/1 to 1/99 (for example, 98/2 to 2/98), 97/3 to 3/97, preferably 96/4 to 4/96, and more preferably 95/5. It may be about 5/95 (for example, 93/7 to 7/93), particularly about 90/10 to 10/90.

  The ratio of such other curable resins may be relatively small or large depending on desired performance requirements (refractive index, heat resistance, flexibility, storage stability, curability, etc.) and the like. When making it comparatively small, the ratio of an episulfide compound and other curable resin (especially epoxy resin) is, for example, the former / the latter (weight ratio) = 99/1 to 40/60 (for example, 98/2 to 45 / 55), preferably 97/3 to 50/50, more preferably 96/4 to 55/45, and even more preferably 95/5 to 60/40 (for example, 90/10 to 65/35). Good.

  On the other hand, when making it comparatively small, the ratio of an episulfide compound and other curable resin (especially epoxy resin) is, for example, the former / the latter (weight ratio) = 50/50 to 1/99 (for example, 45/55). 2/98), preferably 40/60 to 3/97 (for example, 35/65 to 5/95), more preferably about 30/70 to 7/93 (for example, 25/75 to 10/90). May be.

  The curable component may contain a curing agent. As described above, the episulfide compound of the present invention can be singly cured, but includes a curing agent in the case of promoting curability or including other curable resin (epoxy resin) as described above. May be.

Examples of the curing agent include amine-based curing agents [in particular, primary amines such as chain aliphatic amines (for example, chain aliphatic polyamines such as ethylenediamine, hexamethylenediamine, diethylenetriamine, and triethylenetetramine). Cycloaliphatic amines (eg mensendiamine, isophoronediamine, bis (4-amino-3-methylcyclohexyl) methane, 3,9-bis (3-aminopropyl) -2,4,8,10-tetraoxa Monocyclic aliphatic polyamines such as spiro (5.5) undecane; bridged cyclic polyamines such as norbornane diamine), araliphatic polyamines such as xylylenediamine, aromatic amines such as metaphenylenediamine, Diaminodiphenylmethane etc.)], polyaminoamide type hard Agents, acid anhydride curing agents (for example, aliphatic acid anhydrides such as dodecenyl succinic anhydride and polyadipic anhydride; tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride Aliphatic acid anhydrides such as acid, methylhymic anhydride, methylcyclohexene dicarboxylic acid anhydride; aromatic acids such as phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride Anhydrides), phenolic curing agents {eg, phenol resins (eg, novolak resins such as phenol novolak resins and cresol novolak resins); phenols having a fluorene skeleton [eg, 9,9-bis (hydroxyphenyl) fluorene (eg, 9,9-bis (4-hydroxy Phenyl) fluorene), 9,9-bis (alkyl-hydroxyphenyl) fluorene (eg, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, 9,9-bis (4-hydroxy-3, 9,9-bis (mono- or di-C _1-4 alkyl-hydroxyphenyl) fluorene) such as 5-dimethylphenyl) fluorene, 9,9-bis (aryl-hydroxyphenyl) fluorene (eg, 9,9-bis ( 9,9-bis (hydroxyphenyl) fluorenes such as 9,9-bis (mono or diC _6-10 aryl-hydroxyphenyl) fluorene) such as 4-hydroxy-3-phenylphenyl) fluorene; Phenol compounds such as bis (hydroxynaphthyl) fluorenes] and the like. These curing agents may be used alone or in combination of two or more.

  In addition, when the curable component contains only an episulfide compound as a curable resin or when the ratio of the episulfide compound is large, curing is not promoted with an acid anhydride curing agent or the like (does not act as a curing agent or acts as a curing agent). May be difficult). In such a case, an episulfide compound curing agent such as an amine curing agent can be preferably used. The curing agent can be selected according to the application, for example, a phenolic curing agent for semiconductor and structural materials, an amine curing agent for adhesives, and an acid anhydride curing agent for transparent materials. May be suitably used. In the present invention, as described above, by combining with an epoxy resin (particularly, an epoxy resin having a fluorene skeleton), a wide range of curing agents including an acid anhydride curing agent can be used.

  In the curable component, the ratio of the curing agent can be selected according to the ratio of the episulfide group in the episulfide compound, the ratio of the epoxy group in the epoxy resin as another curable resin, or the like. For example, the ratio of the curing agent may be 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. .

  The curable component may further contain a curing accelerator. As described above, the episulfide compound of the present invention can be singly cured, but includes a curing accelerator in cases where the curability is promoted or other curable resins (epoxy resins) are included as described above. You may go out. Moreover, when using an acid anhydride type hardening | curing agent as a hardening | curing agent, the hardening accelerator may be included suitably.

The curing accelerator (or curing catalyst or initiator) can be selected according to the type of the curing agent, for example, amines [for example, tertiary amines (for example, triethylamine, tributylamine, benzyldimethylamine, trimethylamine, Ethanolamine, dimethylaminoethanol, tris (dimethylaminomethyl) phenol, 1,8-diazabicyclo (5.4.0) undecene-1), imidazoles (for example, alkylimidazole such as 2-methylimidazole; 2-phenyl Arylimidazoles such as imidazole) and derivatives thereof (for example, salts such as phenol salts, phenol novolak salts, carbonates, formate salts, etc.)], quaternary ammonium salts [for example, tetra-n-butylammonium chloride, etc. Corresponds to tertiary amine Quaternary ammonium salts, etc.], alkali metal or alkaline earth metal alkoxides, phosphines (such as triphenylphosphine, triethylphosphine, tri-n-butylphosphine), amide compounds (such as dimer acid polyamide), Lewis acid complex compounds (3 such as boron fluoride-ethylamine complex), sulfur compounds [e.g., polysulfide, (For example, 2-mercaptoethanol, thioglycolic acid esters, trimethylolpropane tris (beta-thiopropionate) mercaptan compound etc.), thioester compound ( For example, S-phenylthioacetate etc.], boron compounds (phenyldichloroborane etc.), condensable organometallic compounds (organic titanium compounds, organoaluminum compounds etc.) and the like. The curing accelerators may be used alone or in combination of two or more.

  In the curable component, the proportion of the curing accelerator depends on the type, but is, for example, 0.001 to 50 parts by weight, preferably 0.005 to 30 parts by weight with respect to 100 parts by weight of the curable resin. Preferably, it may be about 0.01 to 10 parts by weight.

  In addition, a curable component (or curable composition) is used as necessary, in addition to a diluent (such as a reactive diluent such as a monofunctional epoxy compound), as well as conventional additives such as a colorant and a stabilizer. (A heat stabilizer, an antioxidant, an ultraviolet absorber, etc.), a filler, an antistatic agent, a flame retardant, a flame retardant aid and the like may be included. Diluents and additives may be used alone or in combination of two or more.

  The cured product can be obtained by reacting (curing treatment) the curable component. Such a curing treatment may be performed while molding a curable component or after molding (or preforming) depending on the 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 includes a product having a desired shape formed from a cured product of the curable component, and a cured film (coating film) formed from the cured product of the curable component formed on a substrate. Or the like. For example, the curable component is melted by heating, poured into a predetermined mold, and cured by heating to obtain a molded body having a desired shape. Moreover, a cured film can be formed on a base material by apply | coating a liquid curable component on a base material, drying, and then heating. A curable component may be dissolved or dispersed in a solvent to obtain a liquid curable component. 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 is, for example, 50 to 250 ° C., preferably 60 to 200 ° C., more preferably 70 to 180 ° C. (for example, 80 to 170 ° C.), and more preferably about 90 to 150 ° C. It may be 160 ° C. or lower [eg, 60 to 155 ° C., preferably 150 ° C. or lower (eg, 70 to 145 ° C.), preferably 140 ° C. or lower (eg, 90 to 135 ° C.)]. The episulfide compound of the present invention is excellent in curability and can be cured at a relatively low temperature even when it is cured alone.

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

  The curable component applied to the substrate may be dried as necessary. A drying process can be performed using a well-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 warming changes also with the solvent to be used and the drying method, it is 40-200 degreeC normally, Preferably it is 50-170 degreeC, More preferably, about 60-150 degreeC may be sufficient.

  As described above, the coating film applied to the substrate is usually 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 characteristics such as a high refractive index and high heat resistance. Moreover, it is excellent in transparency, for example, the 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, a cured product of 90% or more (for example, 92 to 99.5%) can also be obtained.

  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))
A sample was dissolved in tetrahydrofuran using HLC-8320GPC manufactured by Tosoh Corporation, and measurement was performed at a flow rate of 1.0 mL / min, an injection amount of 100 μL, and a temperature of 40 ° C.

(HPLC)
Using Hitachi L-2000, sample dilution rate of 2000 times (acetonitrile), temperature 30 ° C., wavelength 254 nm, flow rate 0.5 mL / min, water / acetonitrile (weight ratio) = 30/70 for 30 minutes, Then, it measured for 30 minutes by water / acetonitrile (weight ratio) = 0/100.

(Refractive index)
Using a multi-wavelength Abbe refractometer “DR-M2 / 1550” (manufactured by Atago Co., Ltd.), measurement was performed at a light source wavelength of 589 nm and a measurement temperature of 25 ° C.

(Light transmittance)
Using a spectrophotometer “U3000” (manufactured by Hitachi High-Tech), measurement was performed at a wavelength of 300 to 800 nm.

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

  Further, 29.27 parts by weight (385 mmol) of thiourea (manufactured by Nacalai Tesque) and 462 parts by weight 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 parts by weight). 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. 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 1.6262.

(Example 2)
The episulfide compound obtained in Example 1 was cured alone as follows without using a curing agent or a curing catalyst (curing accelerator).

  First, the viscous liquid obtained in Example 1 was dissolved in ethyl acetate. The obtained 30% by weight ethyl acetate solution was bar-coated on a slide glass with a thickness of about 60 μm and dried at 60 ° C. for 24 hours. Then, it heated at 130 degreeC for 2 hours, and obtained the film of the colorless and transparent hardened | cured material of thickness 43 micrometers. During heating, hydrogen sulfide was not generated, and the touch of the film was hard. Moreover, the refractive index (25 degreeC, 589 nm) of the film was 1.6487. Furthermore, the transmittance of the film converted to a thickness of 100 μm was 94.3% at 350 nm, 97.1% at 400 nm, and 97.7% at 450 nm, and had high transparency.

(Example 3)
In Example 2, the thickness was 61 μm in the same manner as in Example 2 except that bar coating was performed at a thickness of about 80 μm and heating was performed stepwise (heating at 130 ° C. for 2 hours and 150 ° C. for 2 hours). A colorless and transparent cured product film was obtained. During heating, hydrogen sulfide was not generated, and the touch of the film was hard.

Example 4
In Example 2, a colorless and transparent cured product film having a thickness of 68 μm was obtained in the same manner as in Example 2, except that spin coating (3000 rpm, 3 seconds) was performed at a thickness of about 80 μm instead of bar coating. During heating, hydrogen sulfide was not generated, and the touch of the film was hard.

(Example 5)
In Example 2, instead of bar coating, spin coating (3000 rpm, 3 seconds) was performed at a thickness of about 90 μm, and heating was performed stepwise (heating at 130 ° C. for 2 hours and 150 ° C. for 2 hours in this order). Obtained a transparent and transparent cured film having a thickness of 74 μm in the same manner as in Example 2. During heating, hydrogen sulfide was not generated, and the touch of the film was hard.

(Example 6)
In Example 2, the viscous liquid (episulfide compound) obtained in Example 1 was put into a mold without dissolving in ethyl acetate, and heated stepwise (80 ° C. for 24 hours, 100 ° C. for 24 hours, 120 ° C. A transparent single cured product (33 mm square, thickness 4.1 mm) was obtained in the same manner as in Example 2 except that heating was performed in the order of 18 hours. During heating, hydrogen sulfide was not generated and the cured product was hard to touch.

(Comparative example 1, Examples 7-12)
BPF-2EOG was measured in an aluminum cup and completely dissolved on a hot plate set at 80 ° C. Subsequently, the viscous liquid obtained in Example 1 was added and stirred on a hot plate set at 80 ° C. until uniform. Thereafter, 4,4-diaminodiphenylmethane (DDM) was added as a curing agent, and the mixture was stirred again on a hot plate set at 80 ° C. until uniform. The mixture was heated at 80 ° C. under reduced pressure for 15 minutes, and then cured by heating stepwise in the order of 100 ° C. for 2 hours, 120 ° C. for 2 hours, 140 ° C. for 2 hours, and 160 ° C. for 2 hours. The heating rate was 2 ° C./min.

  The ratio of each component is as shown in the table, and various characteristics measured at various ratios are shown in the table. In the table, for comparison, a comparative example (Comparative Example 1) in which only BPF-2EOG is cured is also described. In Comparative Example 1, curing was performed by heating at 130 ° C. for 2 hours, 170 ° C. for 2 hours, and 200 ° C. for 2 hours in this order. In the table, epoxy is “BPF-2EOG”, episulfide is “solid content of the viscous liquid obtained in Example 1”, and “wt%” of episulfide is a ratio to the total amount of episulfide and epoxy. .

  As is clear from the results in Table 1, the refractive index increased as the content of episulfide was increased, although the Abbe number was unexpectedly maintained at a substantially constant value. Moreover, the elastic modulus decreased.

(Synthesis Example 1)
9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene (manufactured by Osaka Gas Chemical Co., Ltd., hereinafter referred to as BPEF) 1 in the same manner as in Example 2 of JP 2009-139651 A The reaction was carried out using 8 mol of ethylene oxide (EO) per mol to obtain 755 g of product (yield 96% based on BPEF). From the hydroxyl value of the obtained product, 10.8 mol of EO is added to 1 mol of BPEF, that is, 10 mol of 1 mol of 9,9- (4-hydroxy) phenylfluorene (BPF). It was found to be a compound with 0 mol of EO added.

  Subsequently, 95 g (0.12 mol) of the obtained BPF-10EO was dissolved in 88 g (0.96 mol) of chloromethyloxirane (special grade, manufactured by Kishida Chemical Co., Ltd.), and further benzyltriethylammonium chloride (special grade, Kanto Chemical Co., Ltd. (2.0 g) was added, and the mixture was stirred 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. As a result of analyzing the obtained viscous liquid by HPLC and GPC, diglycidyl ether (BPF-10EOG) of a compound in which an average of 10 mol of ethylene oxide was added to 1 mol of 9,9-bis (4-hydroxyphenyl) fluorene. )).

(Example 13)
To a 2 L flask, BPF-10EOG (52.85 g) obtained in Synthesis Example 1 and THF (461 g) were added and dissolved. Moreover, thiourea (15.60 g, 205 mmol) was put into another 1 L flask, and methanol (373 g) was added thereto 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 2 hours. After completion of dropping, the mixture was heated to 40 ° C. and reacted for 43 hours. The progress of the reaction was confirmed by HPLC analysis, and the reaction was continued until the peak corresponding to BPF-10EOG disappeared. The reaction solution returned to room temperature is concentrated to approximately 300 g using a rotary evaporator, then poured into 1 L of distilled water, extracted with ethyl acetate (each extracted once with 300 mL and 200 mL), washed with brine, and dried over magnesium sulfate. did. Dried over magnesium sulfate. Thereafter, the solvent was distilled off to obtain a viscous liquid (57.69 g). 7.9% ethyl acetate remained in the product, and the yield of solid content was 97.1% by weight. As a result of analyzing the obtained viscous liquid by HPLC, GPC, FT-IR and NMR, the main component was an episulfide compound of BPF-10EOG (a compound in which the sum of two m (average value) is 10 in the following formula). Confirmed as including. 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), 6.7 (d, 4H), 4.0 (dd, 2H), 3.8 (dd, 2H), 3.6 (m, 34H), 3.5 (m, 2H), 3.2 (q, 2H), 2.5 (dd , 2H), 2.2 (dd, 2H)
Furthermore, the refractive index (25 degreeC, 589 nm) of the obtained episulfide compound was 1.5789.

(Example 14)
The episulfide compound obtained in Example 13 was cured alone as follows without using a curing agent or a curing catalyst (curing accelerator).

  First, the viscous liquid obtained in Example 13 was dissolved in ethyl acetate. The obtained 30% by weight ethyl acetate solution was bar-coated on a slide glass with a thickness of about 90 μm and dried at 60 ° C. for 24 hours. Then, it heated at 130 degreeC for 2 hours, and obtained the film of the colorless and transparent hardened | cured material with a thickness of 76 micrometers. During heating, hydrogen sulfide was not generated, and the film was a film having some tackiness (tack) and flexibility. Moreover, the refractive index (25 degreeC, 589 nm) of the film was 1.5841. Furthermore, the transmittance of the film converted to a thickness of 100 μm was 96.7% at 350 nm, 98.1% at 400 nm, and 98.7% at 450 nm, and had high transparency.

(Example 15)
In Example 14, the thickness was 53 μm in the same manner as in Example 14 except that bar coating was performed at a thickness of about 60 μm and heating was performed stepwise (heating at 130 ° C. for 2 hours and 150 ° C. for 2 hours). A colorless and transparent cured product film was obtained. During heating, hydrogen sulfide was not generated, and the film was a film having a slightly sticky flexibility.

(Example 16)
In Example 14, the viscous liquid (episulfide compound) obtained in Example 13 was placed in a mold without dissolving in ethyl acetate and heated stepwise (80 ° C. for 24 hours, 100 ° C. for 24 hours, 120 ° C. A transparent single cured product (33 mm square, thickness 3.7 mm) was obtained in the same manner as in Example 14 except that heating was performed in the order of 18 hours. During heating, hydrogen sulfide was not generated, and the film was a film having a slightly sticky flexibility.

(Comparative Example 2)
17.4 g of the viscous liquid (epoxy compound) obtained in Synthesis Example 1 and 0.4 g of triphenylphosphine were mixed with 10 g of an acid anhydride-based curing agent [Licacid MH700 (manufactured by Shin Nippon Rika)], and the mixture was mixed at 130 ° C. for 2 hours. Heated but did not cure under these conditions.

(Example 17)
17.4 g of the viscous liquid (epoxy compound) obtained in Synthesis Example 1 and 3.0 g of the viscous liquid (episulfide compound) obtained in Example 13 were added to 10 g of the acid anhydride-based curing agent [Licacid MH700 (manufactured by Nippon Nippon Chemical Co., Ltd.)]. When 0.4 g of triphenylphosphine was mixed and heated at 130 ° C. for 2 hours, curing proceeded.

  The episulfide compound (or cured product) of the present invention has excellent properties such as high refractive index and high heat resistance. Further, since it has a fluorene skeleton, it is excellent in dispersibility of additives such as pigments.

  Such an episulfide compound (or cured product) of the present invention is useful as an insulating material between electronic component layers, a solder resist for printed circuit boards, a resist material such as a coverlay, and the like, as well as a color filter, an ink (printing ink) Etc.), sealant (semiconductor sealant, etc.), paint, coating agent, adhesive, adhesive, underfill, antistatic agent, filler, conductive member or conductive material, laminate material, thermal material (for thermal paper) Materials), carbon materials, insulating materials, foams, pressure sensitive materials, optical materials (transparent materials) [for example, lenses (reflow lenses, pickup lenses, micro lenses, etc.), polarizing films, antireflection films, touch panel films, Flexible substrate film, display film, fuel cell membrane, optical fiber, optical waveguide, hologram] Any material (electric and electronic materials, optical materials) of which is useful as.

Claims (8)

A curable resin composition comprising an episulfide compound represented by the following formula (1), an epoxy resin, and a curing agent, wherein the curing agent is an amine curing agent, a polyaminoamide curing agent, an acid anhydride A thermosetting resin composition comprising at least one curing agent selected from a system curing agent and a phenol curing agent, and capable of being cured by heating .

(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 1, n is 0 or more. (It is an integer.) The thermosetting resin composition according to claim 1, wherein, in formula (1), Z is a benzene ring or a naphthalene ring. The thermosetting resin composition according to claim 1 or 2, wherein the curing agent comprises an acid anhydride curing agent . And episulfide compound, the proportion of the epoxy resin, the former / the latter (weight ratio) = 99 / 1-1 / 99 in which the thermosetting resin composition according to any one of claims 1 to 3. Epoxy resin, a thermosetting resin composition according to claim 1 is an epoxy resin having a fluorene skeleton. Hardened | cured material which the thermosetting resin composition in any one of Claims 1-5 hardened | cured. The hardened | cured material of Claim 6 whose light transmittance in wavelength 350nm, 400nm and 450nm is all 90% or more. The method according to claim 6 or 7 cured according to curing by heating the thermosetting resin composition according to any one of claims 1 to 5.