JP7475984B2 - Resin composition and method for improving thermal conductivity - Google Patents

Description

The present invention relates to a resin composition containing a thermally conductive filler and a method for improving thermal conductivity.

Taking advantage of the excellent characteristics based on their unique chemical structure, fluorene derivatives are used in various fields as materials for forming organic semiconductors and optical components, and are usually used as resins containing fluorene derivatives as monomer components. US Pat. No. 2,299,948 (Patent Document 1) describes that 9,9-di-(β-carbamoyl-ethyl)fluorene, represented by the following formula, is useful as an intermediate for preparing synthetic resins.

U.S. Pat. No. 2,299,948

In the examples of Patent Document 1, 9,9-di-(β-cyanoethyl)fluorene is reacted with sulfuric acid under specific conditions to prepare the above-mentioned 9,9-di-(β-carbamoyl-ethyl)fluorene.

However, Patent Document 1 does not state or suggest anything about using 9,9-di-(β-carbamoyl-ethyl)fluorene as an additive for resins, particularly as an additive for improving the thermal conductivity of resins.

Therefore, the object of the present invention is to provide a resin composition that exhibits high thermal conductivity.

As a result of intensive research into achieving the above object, the inventors discovered that adding a fluorene derivative having a specific chemical structure to a resin together with a thermally conductive filler can greatly improve thermal conductivity, and thus completed the present invention.

That is, the resin composition of the present invention contains a resin, a thermally conductive filler, and a compound (fluorene derivative) represented by the following formula (1).

[In the formula, R ¹ represents a substituent, k represents an integer of 0 to 8,
R ^2a , R ^2b , R ^2c and R ^2d each independently represent a hydrogen atom or a substituent;
R ^3a and R ^3b each independently represent a hydrogen atom or a substituent;
X ^1a and X ^1b each independently represent a group represented by the following formula (X1):

(wherein R ⁴ and R ⁵ each independently represent a hydrogen atom or a hydrocarbon group, or R ⁴ and R ⁵ combine with each other to form a heterocycle together with the adjacent nitrogen atom).

In the formula (1) or (X1), at least one of ^R4 and ^R5 may be a hydrogen atom. More preferably, one of ^R4 and ^R5 may be a hydrogen atom and the other may be a hydrocarbon group.

The thermally conductive filler may be a nitrogen compound. The resin may contain a curable resin. The ratio of the compound represented by formula (1) may be about 5 to 15 parts by mass relative to 100 parts by mass of the resin, the ratio of the thermally conductive filler may be about 40 to 100 parts by mass relative to 100 parts by mass of the resin, and the ratio of the compound represented by formula (1) to the thermally conductive filler may be the former/latter (mass ratio) = about 1/99 to 20/80.

The present invention includes a cured product formed by curing a resin composition (curable composition) in which the resin contains the curable resin.

The present invention also includes a method of improving thermal conductivity by adding the compound represented by formula (1) and the thermally conductive filler to the resin. Furthermore, the present invention also includes a thermal conductivity improver that includes the compound represented by formula (1) and a thermally conductive filler as an additive (thermal conductivity improver) that improves the thermal conductivity of the resin.

In addition, the present invention may solve the following problems as a secondary objective:

That is, another object of the present invention is to provide a method for improving the thermal conductivity of resin.

Yet another object of the present invention is to provide an additive (thermal conductivity enhancer) that improves the thermal conductivity of resin.

In this specification and claims, the number of carbon atoms of a substituent may be indicated as _C1 , _C6 , _C10 , etc. For example, an alkyl group having one carbon atom is indicated as a " _C1 alkyl" and an aryl group having 6 to 10 carbon atoms is indicated as a " _C6-10 aryl."

The resin composition of the present invention exhibits high thermal conductivity (or heat dissipation) because it contains a fluorene derivative having a specific chemical structure, a thermally conductive filler, and a resin. The present invention also provides a thermal conductivity enhancer that contains the fluorene derivative and a thermally conductive filler, and a method for improving thermal conductivity using the thermal conductivity enhancer.

FIG. 1 is a ¹ H-NMR spectrum of DEAA-FL obtained in Synthesis Example 1. FIG. 2 is a ¹ H-NMR spectrum of DMAA-FL obtained in Synthesis Example 2. FIG. 3 is a ¹ H-NMR spectrum of NIPAM-FL obtained in Synthesis Example 3. FIG. 4 is a ¹ H-NMR spectrum of AAD-FL obtained in Synthesis Example 4.

The resin composition contains at least a resin, a thermally conductive filler, and a compound represented by the following formula (1) (hereinafter also referred to as a fluorene derivative), and the fluorene derivative and the thermally conductive filler function as a thermal conductivity improver (or a heat dissipation improver).

[Fluorene derivatives]

[In the formula, R ¹ represents a substituent, k represents an integer of 0 to 8,
R ^2a , R ^2b , R ^2c and R ^2d each independently represent a hydrogen atom or a substituent;
R ^3a and R ^3b each independently represent a hydrogen atom or a substituent;
X ^1a and X ^1b each independently represent a group represented by the following formula (X1):

(wherein R ⁴ and R ⁵ each independently represent a hydrogen atom or a hydrocarbon group, or R ⁴ and R ⁵ are bonded to each other to form a heterocycle together with the adjacent nitrogen atom).

In the formula (1), the group R ¹ may be a non-reactive substituent that is inert to the reaction, and examples thereof include a cyano group; a halogen atom such as a fluorine atom, a chlorine atom, or a bromine atom; and a hydrocarbon group such as an alkyl group or an aryl group. Examples of the aryl group include a C _6-10 aryl group such as a phenyl group. Preferred groups R ¹ are a cyano group, a halogen atom, or an alkyl group, and particularly an alkyl group.

Examples of the alkyl group include C _1-12 alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group and t-butyl group, preferably C _1-8 alkyl groups, and particularly C _1-4 alkyl groups such as methyl group.

In addition, when the number k of substitutions of the group R ¹ is more than one (2 or more), the types of the two or more groups R ¹ substituted on the same benzene ring among the two benzene rings constituting the fluorene ring may be the same or different, and the types of the two or more groups R ¹ substituted on different benzene rings may be the same or different. In addition, the bonding position (substitution position) of the group R ¹ is not particularly limited as long as it is the 1st to 8th positions of the fluorene ring, and examples thereof include the 2nd position, 7th position, and 2,7th positions of the fluorene ring.

The number of substitutions k may be, for example, an integer of about 0 to 6, and preferred ranges are, in the following stepwise order, integers of 0 to 4, 0 to 3, and 0 to 2, preferably 0 or 1, and particularly preferably 0. Note that in the two benzene rings constituting the fluorene ring, the respective numbers of substitutions of the group R ¹ may be different from each other, but are usually the same.

The substituents represented by R ^2a , R ^2b , R ^2c and R ^2d may be non-reactive substituents that are inactive in the reaction, and examples thereof include hydrocarbon groups such as alkyl groups, cycloalkyl groups, aryl groups and aralkyl groups.

Examples of the alkyl group include linear or branched _C1-10 alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, s-butyl, and t-butyl groups, and are preferably linear or branched _C1-6 alkyl groups, and more preferably linear or branched _C1-4 alkyl groups.

Examples of the cycloalkyl group include a C _5-10 cycloalkyl group such as a cyclopentyl group and a cyclohexyl group.

Examples of the aryl group include C _6-12 aryl groups such as a phenyl group, an alkylphenyl group, a biphenylyl group, a naphthyl group, etc. Examples of the alkylphenyl group include mono- to tri-C _1-4 alkyl-phenyl groups such as a methylphenyl group (or a tolyl group) and a dimethylphenyl group (or a xylyl group).

Examples of the aralkyl group include a C _6-10 aryl-C _1-4 alkyl group such as a benzyl group or a phenethyl group.

Preferred substituents represented by R ^2a , R ^2b , R ^2c and R ^2d include alkyl groups, and preferred alkyl groups are, in the following order, a C _1-6 alkyl group, a C _1-5 alkyl group, a C _1-4 alkyl group and a C _1-3 alkyl group, more preferably a C _1-2 alkyl group, and particularly preferably a methyl group.

Preferred R ^2a , R ^2b , R ^2c , and R ^2d are a hydrogen atom or a hydrocarbon group, more preferably a hydrogen atom or an alkyl group, and even more preferably a hydrogen atom. It is preferable that at least R ^2c and R ^2d are hydrogen atoms, and in such an embodiment, preferred R ^2a and R ^2b are a hydrogen atom or a hydrocarbon group, more preferably a hydrogen atom or an alkyl group, and particularly preferably a hydrogen atom (i.e., R ^2a , R ^2b , R ^2c , and R ^2d are all hydrogen atoms).

Furthermore, the types of R ^2a , R ^2b , R ^2c and R ^2d may be different from one another, but it is preferable that R ^2a and R ^2b are the same, and R ^2c and R ^2d are the same.

The substituents represented by ^R3a and ^R3b may be non-reactive substituents that are inactive in the reaction, and examples of such substituents include hydrocarbon groups such as alkyl groups, cycloalkyl groups, aryl groups, and aralkyl groups. Examples of such hydrocarbon groups include the same groups as the hydrocarbon groups exemplified as the substituents represented by ^R2a and ^R2b .

Among the substituents represented by R ^3a and R ^3b , preferred substituents are alkyl groups, and preferred alkyl groups are, in the following stepwise order, a C _1-6 alkyl group, a C _1-5 alkyl group, a C _1-4 alkyl group, and a C _1-3 alkyl group, more preferably a C _1-2 alkyl group, and particularly preferably a methyl group.

Moreover, R ^3a and R ^3b are preferably a hydrogen atom or an alkyl group, more preferably a hydrogen atom or a methyl group, and particularly preferably a hydrogen atom.

In X ^1a and X ^1b (or formula (X1)), examples of the hydrocarbon group represented by R ⁴ and R ⁵ include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and groups formed by combining a plurality of these groups.

Examples of the alkyl group include linear or branched C1-12 alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, n _- butyl group, isobutyl group, s-butyl group, t-butyl group, pentyl group, neopentyl group, hexyl group, octyl group, and decyl group.

Examples of the cycloalkyl group include a C _5-10 cycloalkyl group such as a cyclopentyl group and a cyclohexyl group.

Examples of the aryl group include C _6-12 aryl groups such as a phenyl group, an alkylphenyl group, a biphenylyl group, a naphthyl group, etc. Examples of the alkylphenyl group include mono- to tri-C _1-4 alkyl-phenyl groups such as a methylphenyl group (or a tolyl group) and a dimethylphenyl group (or a xylyl group).

Examples of the aralkyl group include a C _6-10 aryl-C _1-4 alkyl group such as a benzyl group or a phenethyl group.

Of the hydrocarbon groups represented by R ⁴ and R ⁵ , preferred are linear or branched alkyl groups, more preferred are, in the following order, linear or branched C _1-8 alkyl groups, linear or branched C _1-6 alkyl groups, linear or branched C _1-4 alkyl groups, and among these, linear or branched C _1-3 alkyl groups such as methyl, ethyl, and isopropyl groups are preferred, and from the viewpoint of better dispersibility (or compatibility) in the resin, linear or branched C _2-4 alkyl groups are preferred, more preferably linear or branched C _2-3 alkyl groups. When both R ⁴ and R ⁵ are hydrocarbon groups, the types of R ⁴ and R ⁵ may be different from each other, but are preferably the same.

In addition, the heterocycle (N-containing heterocycle) that may be formed by R ⁴ and R ⁵ bonding together with the adjacent nitrogen atom [i.e., the nitrogen atom that bonds with R ⁴ , R ⁵ and the carbonyl group to form an amide group (amide bond or carboxylic acid amide)] may contain the nitrogen atom as a heteroatom, and may further contain one or more heteroatoms in addition to the nitrogen atom as necessary. Examples of the heteroatom that may be further contained include a nitrogen atom, an oxygen atom, a sulfur atom, and the like, and may contain at least one heteroatom selected from these, and preferably contains at least an oxygen atom. The number of heteroatoms constituting the heterocycle may be, for example, about 1 to 3, preferably 1 to 2, and more preferably 2. The heterocycle is often, for example, a 5- to 7-membered ring (5- to 7-membered heterocycle), preferably a 5- or 6-membered ring, and more preferably a 6-membered ring. In addition, the heterocycle may be aromatic, but is preferably non-aromatic.

Representative heterocyclic rings include, for example, heterocyclic rings containing one or more nitrogen atoms, such as a pyrrolidine ring, a piperidine ring, a homopiperidine ring (an azepane ring, a hexahydroazepine ring, or a hexamethyleneimine ring), and heterocyclic rings containing a nitrogen atom and a heteroatom of a different kind, such as a morpholine ring, and preferably non-aromatic 5- to 7-membered heterocyclic rings containing a nitrogen atom and a heteroatom of a different kind, particularly an oxygen atom, such as a morpholine ring.

In formula (X1), R ⁴ and R ⁵ adjacent to the nitrogen atom may both be hydrogen atoms; one may be a hydrogen atom and the other a hydrocarbon group; R ⁴ and R ⁵ may both be hydrocarbon groups or may be bonded to each other to form a heterocycle. That is, the groups [-C(=O)-X ^1a ] and [-C(=O)-X ^1b ] may be unsubstituted amide groups (primary amide groups); monosubstituted amide groups (or N-substituted amide groups); or disubstituted amide groups (or N,N-disubstituted amide groups).

When the groups [-C(=O)-X ^1a ] and [-C(=O)-X ^1b ] are disubstituted amide groups, it is preferable that both R ⁴ and R ⁵ are aliphatic hydrocarbon groups. Furthermore, the types of X ^1a and X ^1b may be different from each other, but are preferably the same.

From the viewpoint of effectively improving thermal conductivity, it is preferable that at least one of R ⁴ and R ⁵ is a hydrogen atom (i.e., the groups [-C(=O)-X ^1a ] and [-C(=O)-X ^1b ] are unsubstituted amide groups or mono-substituted amide groups), and it is more preferable that one of R ⁴ and R ⁵ is a hydrogen atom and the other is a hydrocarbon group (i.e., the groups [-C(=O)-X ^1a ] and [-C(=O)-X ^1b ] are mono-substituted amide groups). Furthermore, when the groups [-C(=O)-X ^1a ] and [-C(=O)-X ^1b ] are mono-substituted amide groups, the hydrocarbon group represented by either R ⁴ or R ⁵ is preferably an aliphatic hydrocarbon group such as an alkyl group or a cycloalkyl group, more preferably an alkyl group, still more preferably a linear or branched C _1-6 alkyl group such as a methyl group, an ethyl group or an isopropyl group, of which a linear or branched C _2-4 alkyl group is preferred, and a linear or branched C ₃ alkyl group such as an isopropyl group is particularly preferred.

Although the reason why the thermal conductivity is improved by adding a fluorene derivative is not clear, it is speculated that the relationship between the polarity of groups such as an unsubstituted amide group and a monosubstituted amide group, [-C(=O) ^-X1a ] or [-C(=O) ^-X1b ], and the polarity of a thermally conductive filler formed of an inorganic compound or the like, is suitable for dispersing the thermally conductive filler appropriately in the resin composition, thereby enabling efficient formation of a thermally conductive path (or route).

Representative compounds represented by the formula (1) include, for example, compounds in which R ^2a , R ^2b , R ^2c and R ^2d are hydrogen atoms, R ^3a and R ^3b are hydrogen atoms or methyl groups, and both R ⁴ and R ⁵ are hydrogen atoms in the formula (1), specifically, for example, 9,9-bis(2-carbamoyl)C _2-3 alkyl fluorenes such as 9,9 ^- bis( ^{2 -} carbamoylethyl)fluorene and ^{9,9- bis} ( ^{2 -} carbamoylpropyl)fluorene; Compounds in which one of R 2a , R 2b , R 2c and R 2d are hydrogen atoms, R 3a and R 3b are hydrogen atoms or methyl groups, R 4 and R ⁵ are alkyl groups, specifically, for example, 9,9-bis[2-(N-methylcarbamoyl)ethyl]fluorene, 9,9-bis[2-(N-methylcarbamoyl)propyl]fluorene, 9,9-bis[2-(N-ethylcarbamoyl) ^ethyl ]fluorene, _9,9 -bis[2-(N-isopropylcarbamoyl)ethyl]fluorene ^, 9,9 _- bis[ ^2- (N-isopropylcarbamoyl) ^propyl ]fluorene, 9,9-bis[ ^2- (N- ^{butylcarbamoyl} )ethyl]fluorene and the like ^; Compounds in which ⁵ is an alkyl group, specifically, for example, 9,9-bis[2-(N,N-diC 1-6 alkyl-carbamoyl)C 2-3 alkyl]fluorenes such as 9,9-bis[2-(N,N-dimethylcarbamoyl)ethyl]fluorene, 9,9-bis[2-(N,N-dimethylcarbamoyl)propyl]fluorene, 9,9-bis[2-(N,N-diethylcarbamoyl)ethyl]fluorene, 9,9-bis[2-(N,N-diethylcarbamoyl)propyl]fluorene, 9,9 _- bis[ ^2- (N,N-diisopropylcarbamoyl)ethyl]fluorene, ^{and 9,9} _- bis[ ^2- (N, ^N- dibutylcarbamoyl)ethyl]fluorene; Compounds in which ^3b is a hydrogen atom or a methyl group, and R ⁴ and R ⁵ are bonded to each other to form a 5- to 7-membered heterocycle which may further contain at least one heteroatom selected from a nitrogen atom, an oxygen atom, and a sulfur atom in addition to the nitrogen atom constituting the amide group, specifically, for example, 9,9-bis[2-(morpholin-4-yl-carbonyl)ethyl]fluorene, 9,9-bis[2-(morpholin-4-yl-carbonyl)propyl]fluorene, 9,9-bis[2-(pyrrolidin- ₁ -yl-carbonyl)ethyl]fluorene, 9,9-bis[2-(piperidin-1-yl-carbonyl)ethyl]fluorene, 9,9-bis[2-(homopiperidin-1-yl-carbonyl)ethyl]fluorene, and the like, can be mentioned.

These fluorene derivatives can be used alone or in combination of two or more. Among these fluorene derivatives, the following are preferred: in formula (1), R ^2a , R ^2b , R ^2c and R ^2d are hydrogen atoms, R ^3a and R ^3b are hydrogen atoms or methyl groups, and both R ⁴ and R ⁵ are hydrogen atoms (unsubstituted amide compounds); in formula (1), R ^2a , R ^2b , R ^2c and R ^2d are hydrogen atoms, R ^3a and R ^3b are hydrogen atoms or methyl groups, and one of R ⁴ and R ⁵ is a hydrogen atom and the other is an alkyl group (N-alkyl-substituted compounds); in formula (1), R ^2a , R ^2b , R ^2c and R ^2d are hydrogen atoms, R ^3a and R ^3b are hydrogen atoms or methyl groups, and both R ⁴ and R ⁵ are alkyl groups (N,N-dialkyl-substituted compounds). Among these fluorene derivatives, from the viewpoint of effectively improving thermal conductivity, unsubstituted amide compounds and N-alkyl substituted compounds are preferred, and N-alkyl substituted compounds are more preferred.

Preferred unsubstituted amide compounds include 9,9-bis(2-carbamoylC _2-3 alkyl)fluorenes such as 9,9-bis(2-carbamoylethyl)fluorene and 9,9-bis(2-carbamoylpropyl)fluorene.

A preferred N-alkyl substituted compound is 9,9-bis[2-(N-C _1-6 alkyl-carbamoyl)C _2-3 alkyl]fluorene, more preferably 9,9-bis[2-(N-C _2-5 alkyl-carbamoyl)C _2-3 alkyl]fluorene, of which 9,9-bis[2-(N-isopropylcarbamoyl)ethyl]fluorene and other 9,9-bis[2-(N-C _2-4 alkyl-carbamoyl)C _2-3 alkyl]fluorenes are preferred.

[Method of producing fluorene derivative]
The method for producing the compound represented by formula (1) is not particularly limited. For example, the compound represented by formula (2) below may be reacted with compounds represented by formulas (3a) and (3b) below (Michael addition reaction) to prepare the compound represented by formula (1).

(In the formula, ^R1 and k are the same as those in the above formula (1) including preferred embodiments).

(In the formula, R ^2a , R ^2b , R ^2c and R ^2d , R ^3a and R ^3b , X ^1a and X ^1b are the same as in the above formula (1) including preferred embodiments).

A representative example of the compound represented by formula (2) above is 9H-fluorene.

In addition, the compounds represented by the formulas (3a) and (3b) may be either E- or Z-forms depending on the types of R ^2a , R ^2b , R ^2c and R ^2d .

Representative compounds represented by the formulae (3a) and (3b) include, for example, compounds in which R ^2a , R 2b , R ^2c and R ^2d are hydrogen atoms, R ^3a and R 3b are hydrogen atoms or methyl groups, and both R ⁴ and R ⁵ are hydrogen atoms, specifically (meth)acrylamide ^{, etc.; compounds in which R 2a , R 2b , R 2c and R 2d are hydrogen atoms, R 3a and R 3b are hydrogen atoms} or methyl groups, and one of R ⁴ and R ⁵ is a hydrogen atom and the other is an alkyl group, specifically N-C _1-6 ^alkyl- (meth)acrylamide, etc.; compounds in which R ^2a , R ^2b , R ^{2c and R 2d are} hydrogen atoms, R ^3a and R ^3b are hydrogen atoms or methyl groups, and R ⁴ and R Compounds in which both of R and ^{R 5} are alkyl groups, specifically N,N-diC _1-6 alkyl-(meth)acrylamides such as N,N-dimethyl(meth)acrylamide and N,N-diethyl(meth)acrylamide; compounds in which R ^2a , R ^2b , R ^2c and R ^2d are hydrogen atoms, R ^3a and R ^3b are hydrogen atoms or methyl groups, and R ⁴ and R ⁵ are bonded to each other to form a 5- to 7-membered heterocycle which may further contain at least one heteroatom selected from nitrogen atoms, oxygen atoms and sulfur atoms in addition to the nitrogen atom constituting the amide group, specifically N-(meth)acryloyl N-containing heterocycles such as N-(meth)acryloylmorpholine. It is preferable that the compounds represented by the formulas (3a) and (3b) are the same compound.

The ratio of the amount of the compound represented by formula (2) to the total amount of the compounds represented by formulas (3a) and (3b) may be, for example, the former/latter (molar ratio) = about 1/2 to 1/10, and the preferred ranges are 1/2 to 1/5, 1/2.01 to 1/3, and 1/2.03 to 1/2.1 in the following stepwise order.

The reaction may be carried out in the presence of a base, such as a metal hydroxide, a metal carbonate or hydrogen carbonate, or a metal alkoxide.

Examples of metal hydroxides include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and alkaline earth metal hydroxides such as barium hydroxide.

Examples of metal carbonates or bicarbonates include alkali metal carbonates or bicarbonates such as sodium carbonate, potassium carbonate, and sodium bicarbonate.

Examples of metal alkoxides include alkali metal alkoxides such as sodium methoxide, sodium ethoxide, and potassium t-butoxide.

These bases may be used alone or in combination of two or more. Of these bases, metal hydroxides are preferred, and alkali metal hydroxides such as potassium hydroxide are more preferred. The ratio of the base may be, for example, about 0.001 to 0.1 mol, and preferably 0.01 to 0.05 mol, per 1 mol of the compound represented by formula (2).

The reaction may be carried out in the presence or absence of a phase transfer catalyst. Examples of phase transfer catalysts include tetraalkylammonium halides such as tetrabutylammonium bromide (TBAB) and trioctylmethylammonium chloride. These phase transfer catalysts may be used alone or in combination of two or more. Of these phase transfer catalysts, TBAB is preferred. The ratio of the phase transfer catalyst may be, for example, about 0.001 to 0.1 moles, and is preferably 0.01 to 0.05 moles, per mole of the compound represented by formula (2).

The reaction may be carried out in the absence or presence of a solvent inert to the reaction. Examples of the solvent include water; alcohols such as methanol and ethanol; ethers such as cyclic ethers and linear ethers; sulfoxides such as dimethyl sulfoxide (DMSO); and hydrocarbons such as aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons.

Examples of cyclic ethers include 1,4-dioxane and tetrahydrofuran. Examples of chain ethers include dialkyl ethers such as diethyl ether and diisopropyl ether, and glycol ethers. Examples of the glycol ethers include (poly)alkylene glycol monoalkyl ethers such as methyl cellosolve and methyl carbitol, and (poly)alkylene glycol dialkyl ethers such as dimethoxyethane.

Examples of aliphatic hydrocarbons include hexane and dodecane. Examples of alicyclic hydrocarbons include cyclohexane. Examples of aromatic hydrocarbons include toluene and xylene.

These solvents can be used alone or in combination of two or more. Of these solvents, a mixed solvent of water, a sulfoxide such as DMSO, and an aromatic hydrocarbon such as toluene is preferred. Water may be added in the form of an aqueous solution of the above-mentioned base. The amount of solvent used is not particularly limited as long as it does not hinder the progress of the reaction, and may be, for example, about 10 to 500 mL, preferably 50 to 200 mL, per 100 g of the total amount of the compounds represented by the formulas (2), (3a), and (3b).

The reaction may be carried out under an inert gas atmosphere, for example, nitrogen or a rare gas such as helium or argon. The reaction temperature is, for example, 50 to 200°C, preferably 80 to 100°C. The reaction time is not particularly limited and may be, for example, about 0.5 to 10 hours.

After the reaction is completed, the reaction mixture may be separated and purified, if necessary, by conventional separation and purification methods, such as neutralization, washing, extraction, filtration, decantation, concentration, dehydration, drying, crystallization, chromatography, or a combination of these methods.

(Characteristics of fluorene derivatives)
The fluorene derivative obtained as described above may be in a crystalline or amorphous form. In the case of a crystalline form, the melting point may be, for example, about 200 to 300°C, preferably 230 to 280°C, more preferably 240 to 270°C, when the group [-C(=O)-X ^1a ], [-C(=O)-X ^1b ] is an unsubstituted amide group, and may be, for example, about 150 to 300°C, preferably 200 to 270°C, more preferably 220 to 250°C, when the group [-C(=O)-X ^1a ], [-C(=O)-X ^1b ] is a monosubstituted amide group, and may be, for example, about 50 to 200°C, preferably 70 to 180°C, more preferably 80 to ¹⁶⁰ °C, when the group [-C(=O)-X ^1a ], [-C(=O)-X 1b ] is a disubstituted amide group.

The 5% mass loss temperature of the fluorene derivative may be, for example, about 200 to 400°C, and is preferably 230 to 380°C, 250 to 360°C, 280 to 350°C, 300 to 340°C, and 310 to 330°C in the following stepwise order. As such, since the fluorene derivative has high heat resistance, it can be effectively used as a thermal conductivity improver even in high temperature environments.

In this specification and claims, the melting point and 5% mass loss temperature can be measured by the method described in the examples below.

[Thermal conductive filler]
Thermally conductive fillers exhibiting high thermal conductivity are usually fillers of inorganic compounds with high insulating properties, and examples thereof include carbon compounds such as silicon carbide, fluorocarbon, boron carbide, titanium carbide, tungsten carbide, diamond, carbon nanotubes, and graphite; nitrogen compounds (or nitrides) such as boron nitride, aluminum nitride, silicon nitride, carbon nitride, titanium nitride, and gallium nitride; oxygen compounds (or metal oxides) such as silicon oxide (or silica), aluminum oxide (or alumina), magnesium oxide, zinc oxide, and beryllium oxide; and phosphorus compounds such as boron phosphide, aluminum phosphide, and gallium phosphide.

These thermally conductive fillers can be used alone or in combination of two or more. Of these thermally conductive fillers, nitrogen compounds such as boron nitride and aluminum nitride are preferred because of their excellent thermal conductivity, with boron nitride being particularly preferred. The boron nitride may be hexagonal boron nitride (h-BN), which has a crystal structure similar to graphite, or cubic boron nitride (c-BN), which has a diamond structure, with the hexagonal system being more preferred.

The shape of the thermally conductive filler may be, for example, particulate (or powder), plate-like (or scale-like), fibrous, or irregular. Of these shapes, plate-like (scale-like) fillers are preferred. The shape of these particles may be that of primary particles, or may be that of secondary particles formed by agglomeration of primary particles.

The average particle diameter D ₅₀ of the thermally conductive filler can be appropriately selected, for example, from a range of about 0.05 to 50 μm, and the preferred ranges are 1 to 50 μm, 10 to 45 μm, 20 to 40 μm, and 25 to 35 μm in the following stepwise manner. The average primary particle diameter of the thermally conductive filler can be appropriately selected, for example, from a range of about 0.05 to 50 μm, and the preferred ranges are 1 to 50 μm, 10 to 45 μm, 20 to 40 μm, and 25 to 35 μm in the following stepwise manner. In this specification and claims, the average particle diameter D ₅₀ and the average primary particle diameter may be based on volume or the like. When the thermally conductive filler is plate-shaped, the average particle diameter may be the average diameter of the plate surface (the average value of the major axis and the minor axis on the plate surface). The aspect ratio of the average diameter and the thickness of the plate surface (average diameter/thickness of the plate surface) may be, for example, about 2 to 100.

The BET specific surface area (unit: m ² /g) of the thermally conductive filler may be, for example, about 0.1 to 30, preferably 0.5 to 10, and more preferably 1 to 5.

The bulk density (unit: g/cm ³ ) of the thermally conductive filler may be, for example, about 0.2 to 1, preferably 0.3 to 0.8, and more preferably 0.5 to 0.7.

[resin]
Examples of the resin include thermoplastic resins, curable resins (thermosetting or photosetting resins), etc. These resins can be used alone or in combination of two or more kinds.

Examples of thermoplastic resins include polyolefin resins, styrene resins, (meth)acrylic resins, vinyl acetate resins, vinyl chloride resins, fluororesins, polyester resins; polycarbonate resins (PC), polyamide resins (PA), polyacetal resins (POM), polyphenylene ether resins (PPE), polyether ketone resins, phenoxy resins, polyketone resins, polyphenylene sulfide resins (PPS), polysulfone resins, cellulose derivatives, thermoplastic polyimide resins, polyether nitrile resins, and thermoplastic elastomers (TPEs).

Examples of polyolefin resins include linear olefin resins such as polyethylene resins and polypropylene resins, and cyclic olefin resins.

Examples of styrene-based resins include polystyrene (PS) such as general purpose polystyrene (GPPS) and syndiotactic polystyrene (SPS), and styrene-based copolymers. Examples of styrene-based copolymers include styrene-methyl methacrylate copolymer (MS resin), styrene-acrylonitrile copolymer (AS resin), rubber component-containing styrene-based resin or rubber grafted styrene-based copolymer. Examples of rubber component-containing styrene-based resin or rubber grafted styrene-based copolymer include high impact polystyrene (HIPS), acrylonitrile-butadiene-styrene copolymer (ABS resin), AXS resin, methyl methacrylate-butadiene-styrene copolymer (MBS resin), and the like. Examples of AXS resins include acrylonitrile-acrylic rubber-styrene copolymer (AAS resin), acrylonitrile-chlorinated polyethylene-styrene copolymer (ACS resin), acrylonitrile-(ethylene-propylene-diene rubber)-styrene copolymer (AES resin), and the like.

Examples of (meth)acrylic resins include homopolymers or copolymers of (meth)acrylic monomers such as polymethyl methacrylate (PMMA) and (meth)acrylic acid-(meth)acrylic acid ester copolymers.

Examples of vinyl acetate resins include polyvinyl acetate (PVAc), polyvinyl alcohol (PVA), and polyvinyl acetal. Examples of polyvinyl acetal include polyvinyl formal (PVF) and polyvinyl butyral (PVB).

Examples of vinyl chloride resins include vinyl chloride resins and vinylidene chloride resins. Examples of vinyl chloride resins include vinyl chloride homopolymers (PVC); vinyl chloride copolymers such as vinyl chloride-vinyl acetate copolymers; and the like. Examples of vinylidene chloride resins include vinylidene chloride copolymers such as vinylidene chloride-vinyl chloride copolymers and vinylidene chloride-acrylonitrile copolymers.

Examples of fluororesins include polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), ethylene-tetrafluoroethylene copolymer (ETFE), and ethylene-chlorotrifluoroethylene copolymer (ECTFE).

Examples of polyester resins include polyalkylene arylate resins, polyarylate resins, liquid crystal polyesters (LCPs), etc. Examples of polyalkylene arylate resins include polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), poly 1,4-cyclohexyldimethylene terephthalate (PCT), polyethylene naphthalate, etc.

Examples of polycarbonate resins (PC) include bisphenol-type polycarbonate resins such as bisphenol A-type polycarbonate resins.

Examples of polyamide resins (PA) include aliphatic polyamide resins such as polyamide 6 and polyamide 66, aromatic polyamide resins such as poly m-phenylene isophthalamide and poly p-phenylene terephthalamide, and aramid resins.

Examples of polyetherketone resins include polyetherketone resin (PEK), polyetheretherketone resin (PEEK), and polyetherketoneetherketoneketone (PEKEKK).

Examples of polyketone resins include aliphatic polyketone resins.

Examples of polysulfone-based resins include polysulfone resin (PSF) and polyethersulfone (PES).

Examples of cellulose derivatives include cellulose esters such as nitrocellulose, cellulose acetate, and cellulose acetate propionate, and cellulose ethers such as ethyl cellulose.

Examples of thermoplastic polyimide resins include polyetherimide (PEI) and polyamideimide.

Examples of thermoplastic elastomers (TPEs) include polystyrene-based TPEs, polyolefin-based TPEs (TPOs), polydiene-based TPEs, chlorine-based TPEs, fluorine-based TPEs, polyurethane-based TPEs (TPUs), polyester-based TPEs (TPEEs), and polyamide-based TPEs (TPAs).

These thermoplastic resins can be used alone or in combination of two or more.

Examples of curable resins include phenolic resins such as resol-type phenolic resins and novolac-type phenolic resins; amino resins such as urea resins, melamine resins, and guanamine resins; furan resins; unsaturated polyester resins; diallyl phthalate resins; vinyl ester resins (or epoxy (meth)acrylate resins); multifunctional (meth)acrylate resins; epoxy resins; urethane resins; polyimide resins such as bismaleimide resins; and silicone resins.

These curable resins can be used alone or in combination of two or more.

Of these resins, the resin composition is preferably a curable composition that contains at least a curable resin. In the curable composition, the proportion of the curable resin may be selected from a range of, for example, about 1% by mass or more relative to the total resin, and the preferred ranges are as follows, in the following order: 10% by mass or more, 30% by mass or more, 50% by mass or more, 70% by mass or more, 90% by mass or more, 95% by mass or more, and particularly substantially 100% by mass.

Among the curable resins, epoxy resins are preferred. There are no particular limitations on the epoxy resin as long as it is a compound having two or more epoxy groups, and conventional epoxy resins may be used, such as glycidyl ether type epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, cyclic aliphatic type epoxy resins, heterocyclic epoxy resins, and bromine-containing epoxy resins.

Examples of glycidyl ether type epoxy resins include bi- or bisphenol type epoxy resins; novolac type epoxy resins such as phenol novolac type epoxy resins and cresol novolac type epoxy resins; condensed polycyclic aromatic hydrocarbon modified epoxy resins such as 1,6-bis(glycidyloxy)naphthalene; and tetrakisphenol type epoxy resins such as tetrakis(glycidyloxyphenyl)ethane.

Examples of glycidyl ester type epoxy resins include diglycidyl esters of aromatic dicarboxylic acids such as diglycidyl phthalate; diglycidyl esters of hydrogenated aromatic dicarboxylic acids such as diglycidyl tetrahydrophthalate and diglycidyl hexahydrophthalate.

Examples of glycidylamine type epoxy resins include tetraglycidyldiaminodiphenylmethane, triglycidyl-p-aminophenol, triglycidyl-m-aminophenol, tetraglycidyl-m-xylylenediamine, and tetraglycidylbisaminomethylcyclohexane.

Examples of cyclic aliphatic epoxy resins include 3-(3,4-epoxycyclohexyl)-8,9-epoxy-2,4-dioxaspiro[5.5]undecane, bis(3,4-epoxycyclohexylmethyl)adipate, (3,4-epoxycyclohexyl)methyl-3,4-epoxycyclohexanecarboxylate, and 4-vinylcyclohexene dioxide.

Examples of heterocyclic epoxy resins include isocyanurate-type epoxy resins such as triglycidyl isocyanate, and hydantoin-type epoxy resins such as diglycidyl hydantoin.

Examples of bromine-containing epoxy resins include tetrabromobisphenol A type epoxy resins, reaction products of bisphenol A type epoxy resins and tetrabromobisphenol A, reaction products of brominated phenol novolac resins and epichlorohydrin, and diglycidyl tribromoaniline.

These epoxy resins may be monomers or polymers such as dimers and trimers. These epoxy resins may be used alone or in combination of two or more. Among these epoxy resins, glycidyl ether type epoxy resins are preferred, and bi- or bisphenol type epoxy resins are more preferred.

Examples of biphenols that form biphenol- or bisphenol-type epoxy resins include bisphenols such as bis(hydroxyaryl)alkanes, bis(hydroxyaryl)-arylalkanes, bis(hydroxyaryl)cycloalkanes, bis(hydroxyaryl)ethers, bis(hydroxyaryl)ketones, bis(hydroxyaryl)sulfides, bis(hydroxyaryl)sulfoxides, bis(hydroxyaryl)sulfones, and 9,9-bis(hydroxyaryl)fluorenes; biphenols; and alkylene oxide (alkylene carbonate or haloalkanol) adducts thereof.

Examples of bis(hydroxyaryl)alkanes include bis(hydroxyphenyl)C 1-6 alkanes such as bis(4-hydroxyphenyl)methane (bisphenol F), 1,1-bis(4-hydroxyphenyl)ethane (bisphenol AD), 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), 1,1-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)butane (bisphenol B), and 2,2-bis(4-hydroxyphenyl)-3-methylbutane; bis(hydroxy-C _1-6 alkyl-phenyl)C _1-6 alkanes such as 2,2-bis(4-hydroxy-3-isopropylphenyl)propane (bisphenol G); and bis(hydroxy-phenylphenyl)C _1-6 alkanes such as _2,2 -bis(4-hydroxy-3-phenylphenyl)propane.

Examples of bis(hydroxyaryl)-arylalkanes include bis(hydroxyphenyl)-mono- or diphenyl-C 1-6 alkanes such as 1,1-bis(4-hydroxyphenyl)-1-phenylethane (bisphenol AP) and bis(4-hydroxyphenyl) _{-diphenylmethane} (bisphenol BP).

Examples of the bis(hydroxyaryl)cycloalkanes include bis(hydroxyphenyl)C _5-10 cycloalkanes such as 1,1-bis(4-hydroxyphenyl)cyclopentane and 1,1-bis(4-hydroxyphenyl)cyclohexane (bisphenol Z); and bis(hydroxyphenyl)-mono- to tri-C _1-6 alkyl-C _5-10 cycloalkanes such as 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (bisphenol TMC).

Examples of bis(hydroxyaryl) ethers include bis(hydroxyphenyl) ethers such as bis(4-hydroxyphenyl) ether.

Examples of bis(hydroxyaryl)ketones include bis(hydroxyphenyl)ketones such as bis(4-hydroxyphenyl)ketone.

Examples of bis(hydroxyaryl)sulfides include bis(hydroxyphenyl)sulfides such as bis(4-hydroxyphenyl)sulfide.

Examples of bis(hydroxyaryl)sulfoxides include bis(hydroxyphenyl)sulfoxides such as bis(4-hydroxyphenyl)sulfoxide.

Examples of bis(hydroxyaryl)sulfones include bis(hydroxyphenyl)sulfones such as bis(4-hydroxyphenyl)sulfone (bisphenol S).

Examples of the 9,9-bis(hydroxyaryl)fluorenes include 9,9-bis(hydroxyphenyl)fluorene such as 9,9-bis(4-hydroxyphenyl)fluorene; 9,9-bis(hydroxy-mono- or di-C _1-6 alkyl-phenyl)fluorene such as 9,9-bis(4-hydroxy-3-methylphenyl)fluorene and 9,9-bis(4-hydroxy-3,5-dimethylphenyl)fluorene; 9,9-bis(hydroxy-mono- or di-C _6-10 arylphenyl)fluorene such as 9,9-bis(4-hydroxy-3-phenylphenyl)fluorene; and 9,9-bis(hydroxynaphthyl)fluorene such as 9,9-bis(6-hydroxy-2-naphthyl)fluorene and 9,9-bis(5-hydroxy-1-naphthyl)fluorene.

Examples of biphenols include o,o'-biphenol, m,m'-biphenol, and p,p'-biphenol.

Examples of alkylene oxide (alkylene carbonate or haloalkanol) adducts of bisphenols or biphenols include _C2-4 alkylene oxide adducts such as ethylene oxide adducts. The number of moles of alkylene oxide (alkylene carbonate or haloalkanol) added may be, for example, about 2 to 20 moles per mole of bisphenols or biphenols.

The bi- or bisphenol-type epoxy resin may be formed by using these bi- or bisphenols alone or in combination of two or more. Among these bi- or bisphenols, bis(hydroxyaryl)alkanes are preferred, bisphenol F, bisphenol AD, bisphenol A and other bis(hydroxyphenyl)C _1-4 alkanes are more preferred, and bisphenol A is particularly preferred.

Representative bi- or bisphenol-type epoxy resins include, for example, diglycidyl ethers of bis(hydroxyaryl)alkanes (or alkylene oxide adducts) such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, and bisphenol AD type epoxy resin; diglycidyl ethers of bis(hydroxyaryl)sulfones (or alkylene oxide adducts) such as bisphenol S type epoxy resin; epoxy resins having a 9,9-bisarylfluorene skeleton; and diglycidyl ethers of biphenols (or alkylene oxide adducts) such as p,p'-biphenol.

Examples of epoxy resins having a 9,9-bisarylfluorene skeleton include 9,9-bis(glycidyloxyaryl)fluorenes such as 9,9-bis(4-glycidyloxy-phenyl)fluorene, 9,9-bis(6-glycidyloxy-2-naphthyl)fluorene, and 9,9-bis(5-glycidyloxy-1-naphthyl)fluorene; and 9,9-bis[glycidyloxy(poly)alkoxyaryl]fluorenes such as 9,9-bis[4-(2-glycidyloxyethoxy)-phenyl]fluorene, 9,9-bis[4-(2-glycidyloxypropoxy)-phenyl]fluorene, 9,9-bis[4-(2-(2-glycidyloxyethoxy)ethoxy)-phenyl]fluorene, and 9,9-bis[6-(2-glycidyloxyethoxy)-2-naphthyl]fluorene. In this specification and claims, "(poly)alkoxy" is used to mean both alkoxy groups and polyalkoxy groups.

These bi- or bisphenol-type epoxy resins can be used alone or in combination of two or more. Among these bi- or bisphenol-type epoxy resins, diglycidyl ethers of bis(hydroxyaryl)alkanes such as bisphenol A-type epoxy resins are preferred.

[Other ingredients]
The resin composition may or may not contain other components, such as a curing agent, a curing accelerator, a solvent, etc., as necessary.

(Hardening agent)
When the resin contains a curable resin, it may contain a curing agent for curing the curable resin. The curing agent can be appropriately selected depending on the type of the curable resin. When the curable resin is a phenol resin, for example, hexamethylenetetramine (hexamine), paraformaldehyde, 1,3,5-trioxane, and other formaldehyde derivatives, formalin, and the like can be used.

When the curable resin is a resin having a polymerizable unsaturated bond, such as an unsaturated polyester resin, a vinyl ester resin (epoxy (meth)acrylate resin), or a polyfunctional (meth)acrylate resin, examples of the polymerization initiator include a thermal polymerization initiator (thermal radical generator) and a photopolymerization initiator (photoradical generator).

Examples of the thermal polymerization initiator include organic peroxides and azo compounds. Examples of the organic peroxides include dialkyl peroxides such as di-t-butyl peroxide; diacyl peroxides such as lauroyl peroxide and benzoyl peroxide; peracids (or peresters) such as t-butyl hydroperoxide, cumene hydroperoxide, and t-butyl peracetate; ketone peroxides; peroxycarbonates; and peroxyketals. Examples of the azo compounds include azonitrile compounds such as 2,2'-azobis(isobutyronitrile), azoamide compounds, and azoamidine compounds.

Examples of photopolymerization initiators include benzoins, specifically benzoin alkyl ethers such as benzoin and benzoin ethyl ether; acetophenones such as acetophenone and 2-hydroxy-2-methyl-1-phenylpropan-1-one; aminoacetophenones such as 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinoaminopropanone-1; anthraquinones such as anthraquinone and 2-methylanthraquinone; thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, and 2-chlorothioxanthone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenones such as benzophenone; and xanthones. The photopolymerization initiator may also be combined with a photosensitizer. Representative examples of photosensitizers include conventional photosensitizers such as tertiary amines, for example, trialkylamines; trialkanolamines such as triethanolamine; dialkylaminobenzoic acid alkyl esters, specifically, N,N-dimethylaminobenzoic acid ethyl such as p-(dimethylamino)benzoic acid ethyl, N,N-dimethylaminobenzoic acid amyl such as p-(dimethylamino)benzoic acid amyl; bis(dialkylamino)benzophenone such as 4,4-bis(diethylamino)benzophenone; and dialkylaminobenzophenone such as 4-(dimethylamino)benzophenone.

When the curable resin is an epoxy resin, examples of the curing agents include conventional curing agents for epoxy resins, such as amine-based curing agents, polyaminoamide-based curing agents, acid anhydride-based curing agents, and phenolic resin-based curing agents.

As the amine-based curing agent, primary amines are usually preferred, and examples thereof include linear aliphatic polyamines such as ethylenediamine, hexamethylenediamine, diethylenetriamine, and triethylenetetramine; cyclic aliphatic amines such as monocyclic, polycyclic, cross-linked cyclic, and spirocyclic aliphatic polyamines; aromatic aliphatic polyamines such as xylylenediamine; and aromatic amines such as metaphenylenediamine, diaminodiphenylmethane, and 4,4'-diaminodiphenylsulfone. Examples of monocyclic aliphatic polyamines include menthene diamine and isophorone diamine, examples of polycyclic aliphatic polyamines include bis(4-amino-3-methylcyclohexyl)methane, examples of cross-linked cyclic aliphatic polyamines include norbornane diamine, and examples of spirocyclic aliphatic polyamines include 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro[5.5]undecane, etc.

Examples of polyaminoamide-based hardeners include condensates of polyethylene polyamines such as ethylenediamine, diethylenetriamine, and triethylenehexamine with dimer acid and, if necessary, fatty acids.

Examples of acid anhydride curing agents include aliphatic acid anhydrides such as dodecenyl succinic anhydride and polyadipic anhydride; alicyclic acid anhydrides such as tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylhimic anhydride, and methylcyclohexenetetracarboxylic dianhydride; and aromatic acid anhydrides such as phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, and benzophenonetetracarboxylic anhydride.

Examples of phenolic resin-based hardeners include novolac-type phenolic resins such as phenol novolac resin and cresol novolac resin; resol-type phenolic resin; aralkyl-type phenolic resins such as phenol aralkyl resin and naphthol aralkyl resin; epoxidized or butylated modified novolac-type phenolic resin; epoxy-modified phenolic resins such as epoxidized novolac-type phenolic resin; butyl-modified phenolic resins such as butylated (or butyl-etherified) novolac-type phenolic resin; dicyclopentadiene-modified phenolic resin; paraxylene-modified phenolic resin; and multifunctional phenolic resins such as triphenol alkane-type phenolic resin.

These curing agents can be used alone or in combination of two or more. Of these curing agents, epoxy resin curing agents are preferred, and phenolic resin curing agents such as phenol novolac resins are more preferred.

The ratio of the curing agent may be appropriately selected depending on the type of curable resin and curing agent. For example, in the case of a curing agent for an epoxy resin, the ratio of the curing agent may be selected depending on the epoxy equivalent of the epoxy resin that is the curable resin. Specifically, the curing agent may be blended so that the ratio of reactive functional groups or active hydrogen of the curing agent is, for example, 0.5 to 1.5 moles, preferably 0.8 to 1.2 moles, and more preferably approximately equimolar to 1 mole of epoxy groups of the epoxy resin.

The ratio of the curing agent is, for example, 10 to 100 parts by mass, preferably 30 to 80 parts by mass, and more preferably 50 to 60 parts by mass, relative to 100 parts by mass of the curing resin. When the curing resin contains an epoxy resin, the epoxy equivalent of the epoxy resin and the active hydrogen equivalent of the curing agent may be, for example, the former/latter (equivalent ratio) = about 1/0.8 to 1/1.2, preferably 1/0.9 to 1/1.1, more preferably 1/0.95 to 1/1.05, and it is particularly preferable to add the curing agent so that the ratio is substantially 1/1.

(Cure Accelerator)
When the resin contains a curable resin, it may contain a curing accelerator for accelerating curing. The curing accelerator may also be appropriately selected depending on the type of curable resin. Representative curing accelerators include curing accelerators for epoxy resins, such as amines; alkali metal or alkaline earth metal alkoxides; phosphines; amide compounds such as dimer acid polyamide; Lewis acid complex compounds such as boron trifluoride-ethylamine complex; sulfur compounds such as polysulfides and mercaptan compounds (thiol compounds); boron compounds such as phenyldichloroborane; condensable organometallic compounds such as organotitanium compounds and organoaluminum compounds; urethanes such as 1,3-bis(phenylaminocarbonyloxy)benzene; manganese complexes; and sulfonic acid esters.

Examples of amines include tertiary amines, imidazoles and their derivatives. Examples of tertiary amines include triethylamine, tributylamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo[5.4.0]-7-undecene (DBU), and 1,5-diazabicyclo[4.3.0]-5-nonene (DBN). Examples of imidazoles include alkyl imidazoles such as 2-methyl-4-methylimidazole, 2-ethyl-4-methylimidazole, and 1-cyanoethyl-2-ethyl-4-methylimidazole; aryl imidazoles such as 2-phenylimidazole, 2-phenyl-4-methylimidazole, and 2-phenyl-4-methyl-5-hydroxyimidazole; benzimidazoles such as 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole; and 2,4-dicyano-6-[2-methylimidazo-1-yl]ethyltriazine. Derivatives may be, for example, salts such as phenol salts, phenol novolac salts, carbonates, and formates.

Examples of phosphines include organic phosphine compounds such as first phosphines, second phosphines, and third phosphines. Examples of first phosphines include alkyl phosphines such as ethylphosphine and butylphosphine; and aryl phosphines such as phenylphosphine. Examples of second phosphines include dialkyl phosphines such as dimethylphosphine, dipropylphosphine, and methylethylphosphine; and diaryl phosphines such as diphenylphosphine. Examples of third phosphines include trialkyl phosphines such as trimethylphosphine and triethylphosphine; and triaryl phosphines such as triphenylphosphine.

Examples of sulfonate esters include _C1-10 alkyl esters such as p-toluenesulfonic acid neopentyl ester, corresponding benzenesulfonate esters, arenesulfonate alkyl esters such as naphthalenesulfonate ester, _C3-10 cycloalkyl esters such as p-toluenesulfonate cyclohexyl ester, and arenesulfonate cycloalkyl esters such as benzenesulfonate esters and naphthalenesulfonate esters corresponding to this compound.

These curing accelerators may be used alone or in combination of two or more. Among these curing accelerators, phosphines such as tertiary phosphines are preferred, and triarylphosphines such as triphenylphosphine are more preferred.

The ratio of the curing accelerator is, for example, 0.01 to 30 parts by mass, preferably 0.05 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and particularly preferably 0.5 to 5 parts by mass, per 100 parts by mass of the curable resin.

(solvent)
The resin composition of the present invention may or may not contain a solvent (solvent or dispersion medium). The solvent is not particularly limited as long as it can dissolve or disperse the components of the resin composition such as the resin, and examples of the solvent include hydrocarbons, specifically, aliphatic hydrocarbons such as hexane and heptane, alicyclic hydrocarbons such as cyclohexane, and aromatic hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as methylene chloride, chloroform, 1,2-dichloroethane, and chlorobenzene; alcohols such as methanol, ethanol, isopropanol, butanol, and cyclohexanol; glycols (or (poly)alkylene glycols) such as ethylene glycol and dipropylene glycol; glycol ethers, specifically, cellosolves such as ethylene glycol monomethyl ether (or methyl cellosolve), ethyl cellosolve, and butyl cellosolve; carbitols such as diethylene glycol monomethyl ether (or methyl carbitol) and ethyl carbitol; propylene glycol methyl ether, di ... (poly)alkylene glycol (mono- or di)alkyl ethers such as ethylene glycol dimethyl ether; glycol ether acetates, specifically, (poly)alkylene glycol monoalkyl ether acetates such as methyl cellosolve acetate, propylene glycol monomethyl ether acetate, diethylene glycol monobutyl ether acetate, etc.; ethers, specifically, dialkyl ethers such as diethyl ether and diisopropyl ether, cyclic ethers such as dioxane and tetrahydrofuran, etc.; ketones, specifically, chain ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, etc., cyclic ketones such as cyclohexanone, etc.; esters, specifically, acetate esters such as methyl acetate, ethyl acetate, butyl acetate, etc.; nitriles such as acetonitrile; amides such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc.; sulfoxides such as dimethyl sulfoxide, etc.

These solvents may be used alone or in combination as a mixed solvent of two or more. When a solvent is included, the solids concentration of the resin composition is not particularly limited and may be adjusted to exhibit the desired fluidity, for example, about 0.1 to 70 mass%.

(Additive)
The resin composition may further contain conventional additives. Examples of the additives include conventional additives such as fillers or reinforcing agents such as silica, talc, and mica; colorants such as dyes and pigments; flame retardants such as phosphorus-based flame retardants, halogen-based flame retardants, and inorganic flame retardants; flame retardant assistants; plasticizers; lubricants; stabilizers such as antioxidants, ultraviolet absorbers, and heat stabilizers; release agents; conductive agents; antistatic agents; surfactants; dispersants; flow control agents; leveling agents; defoamers; surface modifiers; stress reducing agents; carbon materials; antibacterial agents; and preservatives. These additives may be used alone or in combination of two or more. The proportion of these additives is, for example, 10% by mass or less, preferably 3% by mass or less, based on the entire resin composition (solid content). The proportion may be, for example, about 0.01 to 5% by mass, preferably 0.1 to 1% by mass.

[Preferable ratio in resin composition]
The ratio of the fluorene derivative represented by the formula (1) may be selected from a range of, for example, about 1 to 20 parts by mass relative to 100 parts by mass of the resin, and the preferred ranges are, in the following stepwise order, 3 to 18 parts by mass, 5 to 15 parts by mass, 6 to 12 parts by mass, and more preferably 7 to 10 parts by mass. The ratio of the fluorene derivative represented by the formula (1) is, for example, 1 to 20% by mass, preferably 2 to 10% by mass, more preferably 3 to 8% by mass, and particularly 4 to 6% by mass, relative to the total amount of the components excluding the thermally conductive filler in the resin composition. The "total amount of the components excluding the thermally conductive filler in the resin composition" may be, for example, the total amount of the resin, the fluorene derivative, and the aforementioned additives such as the curing agent, the curing accelerator, and the conventional additives, that is, the total amount of the components (or solids) excluding the thermally conductive filler and the solvent from the resin composition. If the proportion of the fluorene derivative represented by the formula (1) is too small, the thermal conductivity may not be effectively improved, whereas if it is too large, the physical properties such as the mechanical properties of the cured product may be deteriorated.

The proportion of the thermally conductive filler may be selected from a range of, for example, about 10 to 500 parts by mass relative to 100 parts by mass of the resin, and the preferred ranges are 30 to 300 parts by mass, 40 to 100 parts by mass, 50 to 90 parts by mass, 60 to 80 parts by mass, and more preferably 65 to 75 parts by mass. The proportion of the thermally conductive filler is, for example, 1 to 70% by mass, preferably 10 to 50% by mass, more preferably 20 to 40% by mass, and particularly 25 to 35% by mass, relative to the entire resin composition. The "entire resin composition" may be, for example, the total amount of components (or solids) excluding the solvent from the resin composition. If the proportion of the thermally conductive filler is too small, the thermal conductivity may not be effectively improved, and conversely, if it is too large, the physical properties such as the mechanical properties of the cured product, such as flexibility (toughness), may be reduced.

The ratio of the fluorene derivative represented by the formula (1) to the thermally conductive filler may be selected from the range of, for example, the former/latter (mass ratio) = about 0.1/99 to 30/70, 1/99 to 20/80, 5/95 to 15/85, more preferably 7/93 to 13/87, and particularly 8/92 to 12/88. If the ratio of the fluorene derivative represented by the formula (1) is too small, the thermal conductivity may not be effectively improved, and if the ratio of the thermally conductive filler is too small, the thermal conductivity may not be effectively improved. The ratio may be the ratio in a thermal conductivity improver (or heat dissipation improver) containing a fluorene derivative and a thermally conductive filler.

When the fluorene derivative, thermally conductive filler, and resin are combined in the above ratio, the dispersion state of the thermally conductive filler in the resin (or resin composition, particularly the curable composition) is adjusted by the fluorene derivative, and a thermal conduction path (or pathway) is efficiently formed (perhaps because the dispersion state is suitable for the formation of a thermal conduction path), thereby effectively improving thermal conductivity.

[Method of producing resin composition]
The resin composition of the present invention can be prepared by a method including a mixing step of mixing and dispersing the resin, the thermally conductive filler, the fluorene derivative represented by the formula (1), and other components as necessary, in a mixer (or kneader) or stirrer.The mixing (or kneading) may be a conventional method such as dry mixing or melt kneading, and the obtained resin composition may be in the form of pellets or the like.

Examples of mixers (or kneaders) or stirrers include rolls (mixing rolls), ball mills, tumble mixers, ribbon blenders, Henschel mixers, kneaders, and Banbury mixers. Of these, mixing with a mixing roll is preferred.

When mixing (kneading) with a mixing roll, the roll rotation speed may be, for example, about 10 to 50 rpm, preferably 15 to 30 rpm, and more preferably 20 to 25 rpm. The roll rotation speed between the two rolls is often different, and the difference in roll rotation speed between the front and back may be, for example, about 1 to 10 rpm, preferably 1.5 to 5 rpm, and more preferably 2 to 3 rpm.

The mixing (kneading) temperature is, for example, 10 to 200°C, preferably 50 to 150°C, and more preferably 80 to 120°C, and the mixing (kneading) time may be, for example, about 1 to 10 minutes. In addition, if the resin contains a curable resin, the temperature and time may be such that the curable resin does not completely cure.

The resin composition can form a molded article with excellent thermal conductivity. The shape of the molded article is not particularly limited and can be selected according to the application. For example, it may have a one-dimensional structure such as a line or thread, a two-dimensional structure such as a film, sheet or plate, or a three-dimensional structure such as a hollow block, rod, tube or tubular shape.

The molded body may be manufactured using conventional molding methods such as injection molding, injection compression molding, extrusion molding, transfer molding, blow molding, pressure molding, and casting molding.

[Cured product]
(Method for producing the cured product)
When the resin composition is a curable composition (when the resin contains a curable resin), the curable composition can be cured by applying active energy (or active energy rays) to prepare a cured product exhibiting high thermal conductivity. The active energy may be thermal energy and/or light energy.

When curing is performed using thermal energy (heating), the heating temperature can be appropriately selected depending on the type of curable resin, and is, for example, 80 to 300°C, preferably 120 to 250°C, more preferably 150 to 200°C, and particularly preferably 170 to 190°C. The heating time can be selected, for example, from the range of about 1 minute to 12 hours, and is preferably 5 to 60 minutes, and more preferably 10 to 20 minutes.

When light energy such as ultraviolet light or X-rays is used for light irradiation, the amount of light irradiation energy can be appropriately selected depending on the application, and is, for example, 50 to 10,000 mJ/cm ² , preferably 100 to 5,000 mJ/cm ² , and more preferably 500 to 3,000 mJ/cm ² .

The curing process may be performed while applying pressure (press molding) using a press or the like. The molding pressure is, for example, 0.1 to 15 MPa, and preferably 0.5 to 10 MPa. In addition, after press molding, post-curing (or post-baking) may be performed. The heating temperature in post-curing can be appropriately selected depending on the type of curable resin, and is, for example, 80 to 300°C, preferably 120 to 250°C, more preferably 150 to 200°C, and particularly 170 to 190°C. The heating time in post-curing may be selected, for example, from the range of about 0.5 to 24 hours, and is preferably 1 to 12 hours, and more preferably 2 to 6 hours.

The shape of the cured product is not particularly limited, and may be a three-dimensional cured product such as a block, rod, tube, or complex shape; a two-dimensional cured product (or cured film) such as a film, sheet, or plate; or a one-dimensional cured product such as a line or fiber.

Depending on the shape, the cured product may be produced by molding the curable composition or casting (injecting) it into a predetermined mold, followed by a curing treatment (heating and/or light irradiation). In addition, in the case of a two-dimensional cured product, for example, the curable composition may be applied to a base material or substrate, for example, a metal such as aluminum; an inorganic material or ceramic such as titanium oxide, glass, or quartz; an organic material or plastic such as a cyclic olefin resin or polycarbonate resin; or a porous body such as wood, to form a film-like coating (or thin film), which is then cured.

(Characteristics of Resin Composition or Cured Product)
The resin composition or cured product thus obtained has high thermal conductivity. Therefore, the thermal conductivity of the resin composition or cured product is, for example, 0.3 to 3 W/(m·K), preferably 0.5 to 1.5 W/(m·K), more preferably 0.9 to 1.2 W/(m·K), particularly 0.95 to 1.1 W/(m·K). In this specification and claims, the thermal conductivity can be measured at a temperature of 23°C by a disk heat flow meter method in accordance with ASTM E1530, and specifically, can be measured by the method described in the examples below.

The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples. Details of the evaluation method and the reagents used are provided below.

[Evaluation method]
(HPLC)
The HPLC (high performance or high performance liquid chromatograph) device used was an "LCMS-2020" manufactured by Shimadzu Corporation, and the column used was a "KINTEX XB-C18" manufactured by Shimadzu Corporation. The mobile phase was changed from acetonitrile/water (volume ratio) = 50/50 to 95/5 over 10 minutes, and then held at 95/5 for 5 minutes. Measurements were performed under these conditions.

( ^1H -NMR)
The sample was dissolved in a deuterated solvent (CDCl ₃ ) containing tetramethylsilane as an internal standard substance, and ^{the 1} H-NMR spectrum was measured using a nuclear magnetic resonance apparatus ("AVANCE III HD" manufactured by BRUKER).

(Melting Point)
The measurement was carried out using a BUCHI "Melting point M-565" under conditions of a temperature rise rate of 0.5°C/min from a temperature of 50°C.

(5% mass loss temperature)
Using a thermogravimetry-differential thermal analyzer (TG-DTA) ("TGA-4000" manufactured by PerkinElmer), the temperature at which the mass of the sample decreased by 5% by mass was measured under the conditions of a nitrogen atmosphere, a measurement temperature range of 50 to 400° C., and a heating rate of 10° C./min.

(Thermal conductivity)
In accordance with ASTM E1530, the measurement was performed by a disk heat flow meter method using a TA Instruments "DTC-300" under the conditions of a test piece shape: disk (Φ50 mm × thickness about 4 mm), a measurement temperature: 23°C, and a number of measurements: n = 1.

[Reagents, etc.]
(material)
N,N-diethylacrylamide: "DEAA (registered trademark)" manufactured by KJ Chemicals Co., Ltd.
N,N-Dimethylacrylamide: "DMAA (registered trademark)" manufactured by KJ Chemicals Co., Ltd.
N-isopropylacrylamide: "NIPAM (registered trademark)" manufactured by KJ Chemicals Co., Ltd.
N-Acryloylmorpholine: "ACMO (registered trademark)" manufactured by KJ Chemicals Co., Ltd.
Acrylamide: Fujifilm Wako Pure Chemical Industries, Ltd. (Other)
DMSO: dimethyl sulfoxide, manufactured by Kanto Chemical Co., Ltd. Toluene: manufactured by Kanto Chemical Co., Ltd. TBAB: tetrabutylammonium bromide, manufactured by Tokyo Chemical Industry Co., Ltd. KOH: potassium hydroxide, manufactured by Kanto Chemical Co., Ltd. Isopropanol: manufactured by Kanto Chemical Co., Ltd. (curable resin)
Bisphenol A type epoxy resin: "jER828" manufactured by Mitsubishi Chemical Corporation
(Hardening agent)
Novolac phenolic resin: "PSM-4261" manufactured by Gun-ei Chemical Industry Co., Ltd.
(Cure Accelerator)
TPP: Triphenylphosphine, manufactured by Kanto Chemical Co., Ltd. (thermally conductive filler)
Boron nitride: "Hexagonal boron nitride (H-BN) grade HSL" manufactured by Dandong Chemical Engineering Institute Co., flake shape, average particle diameter D ₅₀ : 30 μm, average primary particle diameter: 30 μm, specific surface area (BET): 2 m ² /g, bulk density: 0.6 g/cm ³ .

[Synthesis Example 1]
A reactor equipped with a magnetic stirrer and a three-way cock was charged with 9H-fluorene (19.4 g; 0.117 mol), DMSO (30 mL), toluene (30 mL), TBAB (0.6 g; 0.0019 mol), and N,N-diethylacrylamide (30.5 g; 0.24 mol), and purged with nitrogen. The temperature was raised to 65° C., and complete dissolution was confirmed. A 48% by mass KOH aqueous solution (0.56 g; 0.0048 mol (4.8 mmol) in terms of KOH) was added to the resulting solution, and the temperature was raised to 90° C. and the mixture was heated and stirred for 2 hours. The reaction was terminated when disappearance of 9H-fluorene was confirmed by HPLC. The resulting reaction solution was cooled to 50 ° C., and 10% by mass HCl aqueous solution (0.9 g; 0.0025 mol (2.5 mmol) in terms of HCl) and ion-exchanged water (17 mL) were added and stirred to neutralize, after which toluene (18.1 g) and saturated saline (36.1 g × 3 times) were added and an extraction operation was performed. The resulting extract was cooled to 0 ° C. and left to stand overnight, whereupon white crystals precipitated. The crystals were filtered off and washed with ion-exchanged water (37.3 mL) and isopropanol (10 mL), to obtain the target product represented by the following formula (1-1) (DEAA-FL, 30.2 g; yield 61.4%).

The melting point of the obtained DEAA-FL was 87 to 89° C., and the 5% mass loss temperature was 294° C. The results of ¹ H-NMR of the obtained DEAA-FL are shown below and in FIG.

^1H -NMR ( _CDCl3 , 300MHz): δ (ppm) = 7.69-7.72 (2H, m), 7.27-7.43 (6H, m), 3.18 (4H, q), 2.79 (4H, q), 2.42-2.48 (4H, m), 1.47-1.53 (4H, m), 0.96 (6H, t), 0.76 (6H, t).

[Synthesis Example 2]
A reactor equipped with a magnetic stirrer and a three-way cock was charged with 9H-fluorene (19.4 g; 0.117 mol), DMSO (30 mL), toluene (30 mL), TBAB (0.6 g; 0.0019 mol), and N,N-dimethylacrylamide (23.8 g; 0.24 mol), and purged with nitrogen. The temperature was raised to 65° C., and complete dissolution was confirmed. A 48% by mass KOH aqueous solution (0.56 g; 0.0048 mol (4.8 mmol) in terms of KOH) was added to the resulting solution, and the temperature was raised to 90° C. and the mixture was heated and stirred for 2 hours. The reaction was terminated when disappearance of 9H-fluorene was confirmed by HPLC. The resulting reaction solution was cooled to 50°C, and a 10% by mass HCl aqueous solution (0.9 g; 0.0025 mol (2.5 mmol) in terms of HCl) and ion-exchanged water (17 mL) were added and stirred, whereby white crystals gradually precipitated, forming a white suspension. The suspension was filtered and washed with hot water (77.7 mL) and isopropanol (15 mL), yielding the target product represented by the following formula (1-2) (DMAA-FL, 30.0 g; yield 82.4%).

The melting point of the obtained DMAA-FL was 158 to 159° C., and the 5% mass loss temperature was 318° C. The results of ¹ H-NMR of the obtained DMAA-FL are shown below and in FIG.

^1H -NMR ( _CDCl3 , 300MHz): δ(ppm) = 7.70-7.71 (2H, m), 7.27-7.41 (6H, m), 2.74 (6H, s), 2.51 (6H, s), 2.42-2.47 (4H, m), 1.48-1.54 (4H, m).

[Synthesis Example 3]
A reactor equipped with a magnetic stirrer and a three-way cock was charged with 9H-fluorene (19.4 g; 0.117 mol), DMSO (30 mL), toluene (30 mL), TBAB (0.6 g; 0.0019 mol), and N-isopropylacrylamide (27.2 g; 0.24 mol), and purged with nitrogen. The temperature was raised to 65° C., and complete dissolution was confirmed. A 48% by mass KOH aqueous solution (0.56 g; 0.0048 mol (4.8 mmol) in terms of KOH) was added to the resulting solution, and the temperature was raised to 90° C. and the mixture was heated and stirred for 2 hours. The reaction was terminated when the disappearance of 9H-fluorene was confirmed by HPLC. The resulting reaction solution was cooled to 50°C, and a 10% by mass HCl aqueous solution (0.9 g; 0.0025 mol (2.5 mmol) in terms of HCl) and ion-exchanged water (17 mL) were added and stirred, whereby white crystals gradually precipitated, forming a white suspension. The suspension was filtered and washed with hot water (77.7 mL) and isopropanol (15 mL), yielding the target product represented by the following formula (1-3) (NIPAM-FL, 32.8 g; yield 71.4%).

The melting point of the obtained NIPAM-FL was 235 to 237° C., and the 5% mass loss temperature was 257° C. The results of ¹ H-NMR of the obtained NIPAM-FL are shown below and in FIG.

^1H -NMR ( _CDCl3 , 300MHz): δ(ppm) = 7.68-7.71 (2H, m), 7.32-7.42 (6H, m), 4.73 (2H, m), 3.84 (2H, m), 2.42 (4H, m), 1.33 (4H, m), 0.97 (12H, d).

[Synthesis Example 4]
9H-fluorene (19.4 g; 0.117 mol), DMSO (30 mL), toluene (30 mL), TBAB (0.6 g; 0.0019 mol), and acrylamide (17.0 g; 0.24 mol) were charged into a reactor equipped with a magnetic stirrer and a three-way cock, and the mixture was replaced with nitrogen. The temperature was raised to 65 ° C., and it was confirmed that the mixture was completely dissolved. A 48% by mass KOH aqueous solution (0.56 g; 0.0048 mol (4.8 mmol) in terms of KOH) was added to the obtained solution, and the temperature was raised to 90 ° C., and the mixture was heated and stirred for 2 hours. The reaction was terminated when the disappearance of 9H-fluorene was confirmed by HPLC. The obtained reaction solution was cooled to 50 ° C., and a 10% by mass HCl aqueous solution (0.9 g; 0.0025 mol (2.5 mmol) in terms of HCl) and ion-exchanged water (17 mL) were added and stirred, and white crystals were gradually precipitated, forming a white suspension. The suspension was filtered and washed with hot water (77.7 mL) and isopropanol (15 mL), to obtain the target product represented by the following formula (1-4) (AAD-FL, 31.8 g; yield 88.4%).

The melting point of the obtained AAD-FL was 254 to 259° C., and the 5% mass loss temperature was 320° C. The results of ¹ H-NMR of the obtained AAD-FL are shown below and in FIG.

^1H -NMR (DMSO- _d6 , 300MHz): δ(ppm) = 7.82-7.84 (2H,m), 7.47-7.49 (2H,m), 7.35-7.40 (4H,m), 6.97 (2H,s), 6.52 (2H,s), 2.24 (4H,m), 1.26 (4H,m).

[Synthesis Example 5]
A reactor equipped with a magnetic stirrer and a three-way cock was charged with 9H-fluorene (19.4 g; 0.117 mol), DMSO (30 mL), toluene (30 mL), TBAB (0.6 g; 0.0019 mol), and N-acryloylmorpholine (33.8 g; 0.24 mol), and the contents were substituted with nitrogen. The temperature was raised to 65° C., and it was confirmed that the contents were completely dissolved. A 48% by mass aqueous solution of KOH (0.56 g; 0.0048 mol (4.8 mmol) in terms of KOH) was added to the resulting solution, and the temperature was raised to 90° C., followed by heating and stirring for 2 hours. The reaction was terminated when the disappearance of 9H-fluorene was confirmed by HPLC. The resulting reaction solution was cooled to 50°C, and a 10% by mass HCl aqueous solution (0.9 g; 0.0025 mol (2.5 mmol) in terms of HCl) and ion-exchanged water (17 mL) were added and stirred, whereby white crystals gradually precipitated, forming a white suspension. The suspension was filtered and washed with hot water (77.7 mL) and isopropanol (15 mL), yielding the target product (ACMO-FL) represented by the following formula (1-5).

[Examples 1 to 2, Comparative Example 1]
A curable composition was prepared by kneading a bisphenol A type epoxy resin as a curable resin, a novolac phenol resin as a curing agent, TPP as a curing accelerator, the fluorene derivative obtained in the synthesis example, and boron nitride in the ratios shown in Table 1 (in Comparative Example 1, kneading was performed without adding the fluorene derivative). That is, in the curable compositions of the examples and comparative examples, the ratio of the fluorene derivative was 5 mass% relative to the total amount of the components excluding boron nitride (curable resin, curing agent, curing accelerator, and fluorene derivative); the ratio of boron nitride was 30 mass% relative to the entire curable composition; the epoxy resin and the curing agent were prepared so that the epoxy equivalent ratio was 1:1; and the curing accelerator was 2 mass parts relative to 100 mass parts of the epoxy resin.

The kneading was carried out using a 6-inch mixing roll DY6-15 manufactured by Daihan Co., Ltd. under the following conditions: temperature: 100°C, time: 5 minutes, roll rotation speed: (front) 23.0 rpm/(back) 20.7 rpm, and charge amount: approximately 100 g/batch.

The obtained curable composition was placed in a Φ50 mm pressing die coated with a release agent (Daikin Industries, Ltd.'s "Daifree GF500") and press molded using a Toho Press Manufacturing Co., Ltd. 26-ton hydraulic molding machine under the following conditions: molding temperature: 180°C, molding time: 15 minutes, molding pressure: approximately 5 MPa. The obtained molded body was post-cured (post-baked) in a hot air circulating oven at 180°C for 4 hours to prepare a test specimen (cured product). The thermal conductivity of the obtained test specimen was measured, and the results are shown in Table 1.

As is clear from the results in Table 1, the thermal conductivity of the examples was significantly improved compared to the comparative examples. In particular, the improvement was more significant in Example 2, in which NIPAM-FL was added.

The resin composition of the present invention has excellent thermal conductivity and may be used for a variety of purposes, including heat dissipation materials such as heat dissipation sheets (or heat dissipation films), electrical laminates, insulating varnishes and other molded articles in the electrical and electronic fields, insulating films such as interlayer insulating films and anisotropic conductive films, transparent plastic substrates, optical materials such as optical waveguides, resin modifiers, sealants, adhesives, films, and materials for base station antennas.

Claims (9)

A resin, a thermally conductive filler, and a compound represented by the following formula (1)

[In the formula, R ¹ represents a hydrocarbon group , k represents an integer of 0 to 8,
R ^2a , R ^2b , R ^2c and R ^2d each independently represent a hydrogen atom or a hydrocarbon group ;
R ^3a and R ^3b each independently represent a hydrogen atom or a hydrocarbon group ;
X ^1a and X ^1b each independently represent the following formula (X1):

(In the formula, ^R4 and ^R5 each independently represent a hydrogen atom or a hydrocarbon group, or ^R4 and ^R5 are bonded to each other to form a heterocycle together with the adjacent nitrogen atom.)
It represents a group represented by the following formula:
A resin composition comprising a compound represented by the formula: The resin composition according to claim 1, wherein in the formula (1), at least one of R ⁴ and R ⁵ is a hydrogen atom. 3. The resin composition according to claim 1, wherein in the formula (1), one of ^R4 and ^R5 is a hydrogen atom and the other is a hydrocarbon group. The resin composition according to any one of claims 1 to 3, wherein the thermally conductive filler is a nitrogen compound. The resin composition according to any one of claims 1 to 4, wherein the resin includes a curable resin. The ratio of the compound represented by the formula (1) is 5 to 15 parts by mass relative to 100 parts by mass of the resin,
The ratio of the thermally conductive filler is 40 to 100 parts by mass relative to 100 parts by mass of the resin,
The resin composition according to any one of claims 1 to 5, wherein the ratio of the compound represented by the formula (1) to the thermally conductive filler is the former/latter (mass ratio) = 1/99 to 20/80. A cured product obtained by curing the resin composition according to claim 5 or 6. A method for improving the thermal conductivity of a resin by adding a compound represented by formula (1) according to claim 1 and a thermally conductive filler to the resin. An additive for improving the thermal conductivity of a resin, the thermal conductivity improver comprising a compound represented by formula (1) according to claim 1 and a thermally conductive filler.

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