JP2010196015A - Resin composition and resin cured product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition giving a uniform resin cured product with high electric insulation property and heat conductivity and being excellent in moldability, and a uniform resin cured product with high electric insulation property and heat conductivity. <P>SOLUTION: The resin composition contains a compound having a liquid crystal unit containing a mesogen group, flexible units bonded to both ends of the liquid crystal unit, and a polymerizable group at a terminal end. The flexible unit is a resin composition, i.e., one kind or more of groups selected from the group consisting of a group represented by formula: (wherein, n is an integer of 4 or more). Further, the resin cured product is obtained by polymerizing the resin composition. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a resin composition and a cured resin, and more particularly to a resin composition and a cured resin used in the production of an insulating sheet having excellent electrical insulation and thermal conductivity.

  In recent years, with the increase in functionality, size, and weight of electronic devices, the density of electronic components has been increasing. As a result, the amount of heat generated in the electronic component is remarkably increased, which contributes to a decrease in reliability and life of the component. As described above, the heat problem in electronic devices is a very important issue, and heat dissipation materials used for the countermeasures are required to further improve thermal conductivity. Among heat dissipation materials, resin is used as a heat dissipation material, especially in fields where electrical insulation is required. To improve the thermal conductivity of this resin, inorganic fillers such as inorganic ceramics with high thermal conductivity are added. The technique to do is common. However, in this method, since it is difficult to obtain sufficient thermal conductivity due to the limitation of the addition amount, it is desired to improve the thermal conductivity of the resin itself.

  For the reasons described above, the problem of achieving high thermal conductivity in the resin itself is extremely important, and it contains an epoxy resin having a mesogenic group as a resin cured product with improved thermal conductivity. A resin composition to be used is known (for example, see Patent Document 1). The cured resin obtained from this resin composition is characterized in that a high thermal conductivity of 0.6 W / m · K or more can be obtained without adding an inorganic filler because the mesogenic skeleton is regularly arranged. It is.

Japanese Patent No. 4118691

However, the epoxy resin having a mesogenic group described in Patent Document 1 has a high melting point, and must be melted at a high temperature in order to be uniformly mixed with the epoxy resin curing agent. When this epoxy resin is mixed with a curing agent for epoxy resin at a high temperature, the curing reaction of the epoxy resin proceeds rapidly and the gelation time is shortened. There is a problem that it cannot be obtained. Furthermore, when manufacturing a sheet-like cured resin (that is, an insulating sheet), a resin composition to which a solvent is added is generally used. The epoxy resin described in Patent Document 1 has solubility in a solvent. Since it is low, there also exists a problem that it is difficult to shape | mold into a sheet form with the resin composition using this epoxy resin.
Therefore, the present invention has been made to solve the above-described problems, and provides a cured resin product having a high electrical insulation property and high thermal conductivity, and provides a resin composition excellent in moldability. The purpose is to do. Another object of the present invention is to provide a homogeneous resin cured product having high electrical insulation and thermal conductivity.

In the compound having a liquid crystal unit containing a mesogenic group, the present inventors reduce the melting point by introducing a predetermined flexible unit at both ends of the liquid crystal unit, and reduce the melting point of the solvent generally used in the resin composition. It has been found that the solubility can be improved.
That is, the present invention is a resin composition comprising a compound having a liquid crystal unit containing a mesogenic group, a flexible unit bonded to both ends of the liquid crystal unit, and a terminal polymerizable group, the flexible unit comprising: And the following formula:

It is a resin composition characterized by being one or more groups selected from the group consisting of (wherein n is an integer of 4 or more).
The present invention also provides a cured resin obtained by polymerizing the above resin composition.

  ADVANTAGE OF THE INVENTION According to this invention, the resin composition excellent in the moldability which can give the homogeneous resin hardened | cured material with high electrical insulation and heat conductivity can be provided. Moreover, according to this invention, the homogeneous resin hardened | cured material with high electrical insulation and heat conductivity can be provided.

Embodiment 1 FIG.
The resin composition of the present invention contains a compound having a liquid crystal unit containing a mesogenic group, a flexible unit bonded to both ends of the liquid crystal unit, and a terminal polymerizable group.
The mesogenic group is a functional group exhibiting liquid crystallinity, for example, phenyl benzoate, biphenyl, cyanobiphenyl, terphenyl, cyanoterphenyl, phenylbenzoate, azobenzene, diazobenzene, azomethine, azoxybenzene, stilbene, phenylcyclohexyl, Biphenyl cyclohexyl, phenoxyphenyl, benzylidene aniline, benzyl benzoate, phenyl pyrimidine, phenyl dioxane, benzoyl aniline, tolan and derivatives thereof. Among these, from the viewpoint of thermal conductivity, phenyl benzoate, biphenyl, stilbene, diazobenzene, benzylideneaniline, and derivatives thereof are preferable. In particular, as the liquid crystal unit, those having a biphenyl ester structure (1), a biphenyl ether structure (2), a biphenyl ketone structure (3) and a biphenyl amide structure (4) represented by the following formula are more preferable.

  The flexible unit is a unit that lowers the melting point of the compound and gives the effect of improving the solubility of the compound in the solvent. This flexible unit is bonded to both ends of the liquid crystal unit and is a group represented by the following formula.

In the above formula, n is an integer of 4 or more. When n is less than 4, the effect of lowering the melting point of the compound and the solubility of the compound in the solvent are not sufficient. In the above formula, the carbon portion is bonded to the liquid crystal unit.
Here, the flexible unit can be directly coupled to the liquid crystal unit, but may be coupled via a predetermined atom such as oxygen. From the viewpoint of ease of synthesis, the flexible unit is preferably bonded to the liquid crystal unit via oxygen.

  The compound can have a branched structure from the viewpoint of improving solubility in an organic solvent and lowering the melting point. The branch structure is not particularly limited, and the liquid crystal unit may be branched or may be branched by connecting two or more flexible units to both ends of the liquid crystal unit.

  The compound has at least one polymerizable group at the end in accordance with the purpose of use in order to be used as various resin raw materials. The polymerizable group is not particularly limited, and examples thereof include an epoxy group, a vinyl group, an amino group, a hydroxyl group, an acryloyl group, a cyclohexene group, a methacryloyl group, a cinnamoyl group, an isocyanate group, and a dicarboxylic acid anhydride group. Can be mentioned. In particular, these exemplified polymerizable groups are preferable because they are excellent in crosslinking reactivity.

  The compound having the structure as described above can be generally prepared by a known synthesis method. For example, after reacting and bonding raw material compounds that become liquid crystal units and flexible units, a polymerizable group may be introduced at the terminal. Since the specific conditions for this reaction differ depending on the raw material compounds used, the reaction method, and the like, they cannot be uniquely defined. Therefore, it is necessary to set appropriately according to the raw material compound used, the reaction method, and the like.

In the resin composition of the present invention, the liquid crystal unit, the flexible unit, and the compound having a polymerizable group have a low melting point and a high solubility in a solvent. Therefore, various resin raw materials (for example, for preparing a homopolymer) Monomer, epoxy resin, epoxy resin curing agent, etc.).
When the terminal polymerizable group is a homopolymerizable group (for example, a vinyl group), the compound is used as a monomer for preparing a homopolymer. The resin composition containing this monomer can give a cured resin cured by the reaction between the monomers. Moreover, this resin composition can further contain a polymerization initiator.
The polymerization initiator that can be used in the resin composition is not particularly limited, and for example, an azo initiator, a peroxide initiator, a persulfate initiator, and the like can be used. These polymerization initiators may be used alone or in combination of two or more.

  Examples of the azo initiator include 2,2′-azobisisobutyronitrile (AIBN), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), and 2,2′-azobis. (2-amidinopropane) dihydrochloride, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis-2-methylbutyronitrile, 1,1-azobis (1-cyclohexanecarbo) Nitrile), 2,2′-azobis (2-cyclopropylpropionitrile), 2,2′-azobis (methylisobutyrate) and the like.

Examples of the peroxide initiator include benzoyl peroxide, acetyl peroxide, lauroyl peroxide, decanoyl peroxide, dicetyl peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, di (2 -Ethylhexyl) peroxydicarbonate, t-butylperoxypivalate, t-butylperoxy-2-ethylhexanoate, and dicumyl peroxide.
Examples of persulfate initiators include potassium persulfate, sodium persulfate, and ammonium persulfate.
What is necessary is just to set suitably the compounding quantity of the polymerization initiator in this resin composition according to each component to be used, and generally 0.1 mass part or more and 200 mass parts or less with respect to 100 mass parts monomer. is there.

When the terminal polymerizable group is an epoxy group, the compound is used as an epoxy resin. The resin composition containing this epoxy resin can give the resin cured material bridge | crosslinked by reaction of an epoxy resin and the curing agent for epoxy resins by further mix | blending the curing agent for epoxy resins.
The curing agent for epoxy resin that can be used in this resin composition is not particularly limited, and examples thereof include alicyclic acid anhydrides such as methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, and hymic anhydride. Aliphatic acid anhydrides such as dodecenyl succinic anhydride; aromatic acid anhydrides such as phthalic anhydride and trimellitic anhydride; organic dihydrazides such as dicyandiamide and adipic acid dihydrazide; and tris (dimethylaminomethyl) phenol Dimethylbenzylamine, 1,8-diazabicyclo (5,4,0) undecene and derivatives thereof, and imidazoles such as 2-methylimidazole, 2-ethyl-4-methylimidazole, and 2-phenylimidazole. . These epoxy resin curing agents may be used alone or in combination of two or more.

Among the curing agents for epoxy resins, from the viewpoint of improving the alignment of the liquid crystal structure of a resin cured product (polymer) obtained by polymerizing a resin composition, such as diaminodiphenylmethane, diaminodiphenylethane, and diaminodiphenylsulfone. Aromatic diamines; and catechol, methyl catechol, dimethyl catechol, butyl catechol, phenyl catechol, methoxy catechol, pyrogallol, methyl hydroquinone, tetrahydroxybenzene, bromo catechol, 1,2-dihydroxynaphthalene, methyl-1,2-dihydroxynaphthalene, Dimethyl-1,2-dihydroxynaphthalene, butyl-1,2-dihydroxynaphthalene, methoxy-1,2-dihydroxynaphthalene, hydroxy-1,2-dihydroxynaphthalene, dihydro Ci-1,2-dihydroxynaphthalene, bromo-1,2-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, methyl-2,3-dihydroxynaphthalene, dimethyl-2,3-dihydroxynaphthalene, butyl-2,3-dihydroxy Naphthalene, methoxy-2,3-dihydroxynaphthalene, hydroxy-2,3-dihydroxynaphthalene, dihydroxy-2,3-dihydroxynaphthalene, bromo-2,3-dihydroxynaphthalene, 1,8-dihydroxynaphthalene, methyl-1,8 -Dihydroxynaphthalene, dimethyl-1,8-dihydroxynaphthalene, butyl-1,8-dihydroxynaphthalene, methoxy-1,8-dihydroxynaphthalene, hydroxy-1,8-dihydroxynaphthalene, dihydroxy-1,8- Hydroxynaphthalene, and polyhydric phenol compound such as bromo-1,8-dihydroxynaphthalene are preferred.
What is necessary is just to set suitably the compounding quantity of the hardening | curing agent for epoxy resins in this resin composition according to each component to be used, and generally 0.1 mass part or more and 200 mass parts or less with respect to 100 mass parts epoxy resin. It is.

When the terminal polymerizable group is a group capable of reacting with an epoxy resin (for example, a hydroxyl group or an amino group), the compound is used as a curing agent for the epoxy resin. The resin composition containing this epoxy resin curing agent can give a cured resin cured by the reaction of the epoxy resin curing agent and the epoxy resin by further blending the epoxy resin.
The epoxy resin that can be used in this resin composition is not particularly limited. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, anthracene type epoxy resin, Examples include ortho-cresol novolac type epoxy resins, phenol novolac type epoxy resins, alicyclic aliphatic epoxy resins, and glycidyl-aminophenol type epoxy resins. These epoxy resins may be used alone or in combination of two or more.

Among the above epoxy resins, biphenyl type epoxy resin, naphthalene type epoxy resin, and anthracene type epoxy resin are used from the viewpoint of improving the alignment of the liquid crystal structure of the cured resin (polymer) obtained by polymerizing the resin composition. preferable.
What is necessary is just to set suitably the compounding quantity of the hardening | curing agent for epoxy resins in this resin composition according to each component to be used, and generally 0.1 mass part or more and 200 mass parts or less with respect to 100 mass parts epoxy resin. It is.

  Since each of the above resin compositions contains a compound having a liquid crystal unit containing a mesogenic group, the resin composition has a property that a mesogenic structure is regularly arranged to be in a liquid crystal state in a specific temperature range. Examples of the liquid crystal state include a nematic phase, a smectic phase, and a cholesteric phase. Also, a resin cured product (polymer) obtained by polymerizing this resin composition can give a structure in which mesogenic structures are regularly arranged as in the liquid crystal state. This arrangement structure is preferably a smectic phase and a nematic phase in which the mesogenic structure is oriented in a certain direction. Here, the smectic phase means a state in which the major axis direction of the polymer is aligned in a certain direction and the polymer is arranged in a layered manner. The nematic phase means that the polymer has no order at the center of gravity, but its major axis is aligned in a certain direction. The higher the regularity of such an array structure, the higher the thermal conductivity.

The resin composition of the present invention can further contain an inorganic filler from the viewpoint of improving the thermal conductivity of the cured resin.
The inorganic filler that can be used in the resin composition of the present invention is not particularly limited, and examples thereof include metals such as nickel, tin, aluminum, gold, silver, copper, iron, cobalt, indium, and alloys thereof. Particles: Metal oxide particles such as aluminum oxide (alumina), zinc oxide, indium tin oxide (ITO), magnesium oxide, beryllium oxide, and titanium oxide; metal nitride particles such as boron nitride, silicon nitride, and aluminum nitride; silicon carbide And carbon compound particles such as graphite, diamond, amorphous carbon, carbon black and carbon fiber; and silica compound powders such as quartz and quartz glass. These inorganic fillers may be used alone or in combination of two or more.
Among the inorganic fillers, aluminum oxide, zinc oxide, magnesium oxide, beryllium oxide, titanium oxide, boron nitride, silicon nitride, aluminum nitride, diamond, quartz, quartz glass, and the like are preferable from the viewpoint of insulating properties of the cured resin. .

The average particle size of the inorganic filler is preferably 0.1 μm or more and 150 μm or less, more preferably 3 μm or more and 120 μm or less. When the average particle size of the inorganic filler is less than 0.1 μm, it may be difficult to disperse the inorganic filler due to secondary aggregation. On the other hand, when the average particle size of the inorganic filler exceeds 150 μm, surface roughness of the cured resin product may easily occur when molded into a sheet shape.
The blending ratio of the inorganic filler in the resin composition of the present invention is such that the inorganic filler is preferably 20% by volume to 80% by volume, more preferably 30% by volume to 70% by volume in the resin cured product. A ratio is desirable. If it is the ratio of this range, when shape | molding a resin composition in a sheet form, while being excellent in workability | operativity, the heat conductivity of resin cured material can be improved further. If the proportion of the inorganic filler in the cured resin is less than 20% by volume, a cured resin having desired thermal conductivity may not be obtained. On the other hand, when the ratio of the inorganic filler in the cured resin exceeds 80% by volume, it becomes difficult to uniformly disperse the inorganic filler in the cured resin when the sheet-shaped cured resin is produced. May cause troubles in formability and formability.

In addition, the inorganic filler can be subjected to a coupling treatment for the purpose of improving the wettability of the inorganic filler, reinforcing the interface between the resin component and the inorganic filler, and improving the dispersibility of the inorganic filler. Examples of coupling agents that can be used for this treatment include γ-glycidoxypropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, and N-phenyl-γ-aminopropyltrimethoxysilane. , And γ-mercaptopropyltrimethoxysilane and the like. These coupling agents may be used alone or in combination of two or more.
The amount of the coupling agent used may be appropriately set according to the resin component, the type of the coupling agent, and the like, but is generally 0.01 parts by mass or more and 1 part by mass or less with respect to 100 parts by mass of the resin component. It is.

The resin composition of the present invention can be molded into a desired shape and then polymerized by heating to obtain a cured resin having a desired shape. In particular, in the case of producing a sheet-like cured resin, the resin composition of the present invention may be applied to an alignment substrate and dried, and then heated for polymerization.
The coating method on the alignment substrate is not particularly limited, and either a melting method or a solution method may be adopted, but a solution method is preferable from the viewpoint of workability. Moreover, when coating by a solution method, suitable coating machines, such as a bar coater, a multi-coater, a spinner, a roll coater, can be used. Moreover, it is appropriate to use the casting method in terms of the surface quality of the cured resin.

When using a solution method, a solvent can be mix | blended with the resin composition of this invention. The solvent is not particularly limited, and examples thereof include halogenated hydrocarbons such as chloroform, dichloromethane, dichloroethane, tetrachloroethane, trichloroethylene, tetrachloroethylene, and chlorobenzene; phenols such as phenol and parachlorophenol; benzene, Aromatic hydrocarbons such as toluene, xylene, methoxybenzene, and 1,2-dimethoxybenzene; acetone; ethyl acetate; tert-butyl alcohol; glycerin; ethylene glycol; triethylene glycol; ethylene brickol monomethyl ether; Ethyl cellosolve; butyl cellosolve; 2-pyrrolidone; N-methyl-2-pyrrolidone; pyridine; triethylamine; tetrahydrofuran; Le formamide; dimethylacetamide; dimethylsulfoxide; acetonitrile; butyronitrile; carbon disulfide; methyl ethyl ketone; cyclohexanone; cyclopentanone and the like.
The content of the solvent in the resin composition is not particularly limited, and is generally 50% by mass or more and 70% by mass or less.

The resin composition coated on the alignment substrate can be dried at room temperature, but may be heated to 80 ° C. or higher and 150 ° C. or lower as necessary to promote solvent volatilization.
The heating temperature for polymerizing the resin composition needs to be appropriately set according to each component, but is generally 60 ° C. or higher and 280 ° C. or lower. Similarly, the polymerization time needs to be appropriately set according to the amount of each component and resin composition.

Since the cured resin obtained from the resin composition of the present invention has high thermal conductivity and insulation, it can be used as an insulating sheet that is generally used as a heat dissipation material for electronic devices.
When the cured resin is used as an insulating sheet, the thickness of the insulating sheet is preferably 20 μm or more and 800 μm or less, more preferably 30 μm or more and 300 μm or less. When the thickness of the insulating sheet is less than 20 μm, when the insulating sheet is sandwiched between the members, the followability to the unevenness of the sandwiching surface is insufficient, and the interfacial thermal resistance may increase. On the other hand, if the thickness of the insulating sheet exceeds 800 μm, the heat transfer distance becomes long, and the thermal resistance may increase.

EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated concretely, this invention is not limited to the following Example.
Example 1
21.2 g of 4-hydroxybenzoic acid methyl ester, 25 g of 6-bromo-1-hexene, 57.8 g of potassium carbonate, and 200 mL of dimethylformamide were placed in an eggplant-shaped flask and subjected to nitrogen substitution. And reacted for 24 hours while stirring. After completion of the reaction, the reaction product was added to 1 L of water, and 300 mL of dichloromethane was added to the reaction product for extraction. This dichloromethane solution was washed with 200 mL of water three times, magnesium sulfate was added to remove water, and then dichloromethane was removed with an evaporator. The obtained crude product was purified by column chromatography using a mixed solvent of dichloromethane and hexane (volume ratio: dichloromethane / hexane = 10/1) to give 4- (5-hexenylosyloxy) benzoic acid as a yellow liquid. 35 g of methyl ester was obtained.

Next, 30 g of 4- (5-hexenyloxy) benzoic acid methyl ester was added to 3N aqueous potassium hydroxide solution and stirred at 80 ° C. for 24 hours. After filtering this solution, it cooled to room temperature and acidified by performing 6N hydrochloric acid aqueous solution slowly throwing in. Then, 25.8g of 4- (5-hexenyloxy) benzoic acid of the white crystal | crystallization was obtained by drying under reduced pressure using calcium chloride as a desiccant.
Next, 10 g of 4- (5-hexenyloxy) benzoic acid was added to the flask, and then 100 mL of thionyl chloride was slowly added thereto, followed by stirring at 40 ° C. for 2 hours. Then, 23 g of 4- (5-hexenyloxy) benzoic acid chloride was obtained by removing excess thionyl chloride by distillation under reduced pressure.
Next, after 4.7 g of biphenyl-4,4′-diol and 7.7 g of triethylamine were dissolved in 100 mL of tetrahydrofuran at room temperature, the solution was cooled in an ice bath. To this cooled solution, 100 mL of tetrahydrofuran in which 15.8 g of 4- (5-hexenyloxy) benzoic acid chloride was dissolved was slowly added dropwise, and the mixture was stirred at room temperature for 4 hours after the completion of the addition. Next, the obtained solution was filtered to remove triethylamine hydrochloride, and then the solvent was removed by an evaporator. Then, 13.9g of vinyl compounds represented by following formula (5) of a white crystal | crystallization were obtained by wash | cleaning the obtained product with methanol.

The structure of the synthesized vinyl compound was confirmed by infrared spectroscopic analysis and ¹ H-NMR and ¹³ C-NMR measurements. Further, the melting point of the vinyl compound was measured using differential scanning calorimetry (DSC) under conditions of a heating rate of 10 ° C./min. In the following examples, the confirmation of the structure of the compound and the measurement of the melting point were carried out in the same manner as in this method.
A uniform resin composition was prepared by adding 10 g of this vinyl compound to an aluminum petri dish, adding 0.028 g of 2,2′-azobisisobutyronitrile (AIBN) as a polymerization initiator, and stirring and mixing. This resin composition was polymerized by heating in an oven at 180 ° C. for 4 hours to obtain a homogeneous cured resin product. When the cured resin was observed using a polarizing microscope, the orientation of the polymer was confirmed.

(Example 2)
After dissolving 13.9 g of the vinyl compound represented by the above formula (5) in 100 mL of chloroform, 6.9 g of 3-chloroperbenzoic acid was slowly added, and the mixture was stirred at room temperature for 48 hours to be reacted. After completion of the reaction, the reaction solution was transferred to a separatory funnel and washed with 100 mL of 1N aqueous sodium hydrogen carbonate solution. After repeating this washing operation three times, magnesium sulfate was added to the organic layer to remove moisture, and the solvent was removed with an evaporator. The obtained solid was dissolved in 50 mL of dichloromethane and re-precipitated by adding it to 300 mL of hexane to obtain 13 g of an epoxy resin represented by the following formula (6).

  10 g of this epoxy resin is placed in an aluminum petri dish placed on a hot plate maintained at 180 ° C., and 1.59 g of a diaminodiphenylmethane (DDM) curing agent previously dissolved in an oven at 150 ° C. is added and mixed by stirring. A uniform resin composition was prepared. This resin composition was polymerized by heating in an oven at 180 ° C. for 4 hours to obtain a homogeneous cured resin product. When the cured resin was observed using a polarizing microscope, the orientation of the polymer was confirmed.

(Example 3)
2 g of biphenyl-4,4′-diol and 10 ml of triethylamine were dissolved in 50 mL of tetrahydrofuran at room temperature, and then the solution was cooled in an ice bath. To this cooled solution, 20 mL of tetrahydrofuran in which 7 g of 3,4,5-trimethoxybenzoyl chloride was dissolved was slowly added dropwise, and stirred at room temperature for 4 hours after the completion of the addition. Next, the obtained solution was filtered to remove triethylamine hydrochloride, and then the solvent was removed by an evaporator. Thereafter, the obtained product was washed with methanol to obtain 3.9 g of biphenyl-4,4′-diylbis (3,4,5-trimethoxybenzoate).
Next, 3 g of biphenyl-4,4′-diylbis (3,4,5-trimethoxybenzoate) was dissolved in 200 mL of dichloromethane and cooled in an ice bath, and 30 g of tribromide was added to the cooled solution. Boron was slowly added dropwise. The precipitated solid was filtered and then dried in a vacuum drier to obtain 2.5 g of biphenyl-4,4′-diylbis (3,4,5-trihydroxybenzoate).

Next, 2.0 g biphenyl-4,4′-diylbis (3,4,5-trihydroxybenzoate), 8.0 g 6-bromo-1-hexanoic acid, 6.9 g potassium carbonate, and 150 mL Dimethylformamide was placed in an eggplant-shaped flask and purged with nitrogen. Then, the reaction was conducted by heating and stirring at 80 ° C. for 24 hours. After the completion of the reaction, the reaction product was poured into 1 L of water, and then the precipitate was filtered off and washed with methanol to obtain 6,6 ′, 6 ″-(5-((4 ′-(4- (4 -Carboxybutoxy) -3,5-bis (5-carboxypentyloxy) benzoyloxy) biphenyl-4-yloxy) carbonyl) benzene-1,2,3-triyl) tris (oxy) trihexanoic acid.
Next, 4 g of this compound and 9.3 g of 4-allyloxybenzoic acid 4-hydroxyphenyl ester were dissolved in 10 mL of N-methyl-2-pyrrolidone, and then diphenyl (2,3-dihydro-2 as a condensing agent). -Thioxo-3-benzoxazoyl) phosphonate (9.3 g of DBOP) was added and stirred for 24 hours at room temperature, and then the reaction solution was poured into 200 mL of 1N aqueous sodium hydrogen carbonate solution. After washing with methanol, drying under reduced pressure was performed to obtain 13 g of a vinyl compound represented by the following formula (7).

  A uniform resin composition was prepared by putting 10 g of this vinyl compound into an aluminum petri dish, adding 0.006 g of 2,2′-azobisisobutyronitrile (AIBN) as a polymerization initiator, and stirring and mixing. This resin composition was polymerized by heating in an oven at 180 ° C. for 4 hours to obtain a homogeneous cured resin product. When the cured resin was observed using a polarizing microscope, the orientation of the polymer was confirmed.

Example 4
After dissolving 5 g of the vinyl compound represented by the above formula (7) in 200 mL of chloroform, 30 g of 3-chloroperbenzoic acid was slowly added, and the mixture was stirred at room temperature for 48 hours to be reacted. After completion of the reaction, the reaction solution was transferred to a separatory funnel, and washed with 100 mL of 1N aqueous sodium hydrogen carbonate solution. After repeating this washing operation three times, magnesium sulfate was added to the organic layer to remove water, and the solvent was further removed by an evaporator. The obtained solid was dissolved in 200 mL of dichloromethane, and this was poured into 500 mL of hexane to reprecipitate, thereby obtaining 4.5 g of an epoxy resin represented by the following formula (8).

  10 g of this epoxy resin is placed in an aluminum petri dish placed on a hot plate maintained at 180 ° C., and 1.07 g of a diaminodiphenylmethane (DDM) curing agent previously dissolved in an oven at 150 ° C. is added and mixed by stirring. A uniform resin composition was prepared. This resin composition was polymerized by heating in an oven at 180 ° C. for 4 hours to obtain a cured resin. When the cured resin was observed using a polarizing microscope, the orientation of the polymer was confirmed.

(Example 5)
After putting 10 g of biphenyl, 53 g of iron (III) chloride and 200 mL of dichloromethane in a 500 mL three-necked flask, 100 mL of dichloromethane solution in which 55 g of 4-methoxybenzoyl chloride was dissolved was slowly added dropwise while cooling in an ice bath bath. . After the dropwise addition, the mixture was stirred for 8 hours in an ice bath and further stirred for 4 hours at room temperature. After completion of the reaction, the reaction solution was added to ice, hydrochloric acid was slowly added, and the mixture was stirred for 6 hours. The solid was filtered and then dissolved in 200 mL of chloroform. The solution was transferred to a separatory funnel and washed three times with 100 mL of water, then three more times with 100 mL of 1N aqueous sodium bicarbonate and finally with 100 mL of water. After removing water by adding magnesium sulfate to the organic layer, the solvent was removed by an evaporator, and the remaining solid was washed with methanol to obtain 9 g of biphenyl-4,4′-diylbis (4-methoxyphenyl) methanone. .
Next, 8 g of biphenyl-4,4′-diylbis (4-methoxyphenyl) methanone was dissolved in 200 mL of dichloromethane, and then cooled in an ice bath, to which 19 g of boron tribromide was slowly added dropwise. . The precipitated solid was filtered and dried with a vacuum drier to obtain 7.5 g of biphenyl-4,4′-diylbis (4-hydroxyphenyl) methanone.

Next, 7 g of biphenyl-4,4′-diylbis (4-hydroxyphenyl) methanone, 8.7 g of 6-bromo-1-hexene, 8 g of potassium carbonate, and 200 ml of dimethylformamide were placed in a flask and purged with nitrogen. After performing, it was made to react by stirring at 80 degreeC for 24 hours. After completion of the reaction, the reaction product was poured into 1 L of water, and 300 mL of dichloromethane was added for extraction. The resulting dichloromethane solution was washed 3 times with 200 mL of water. Next, magnesium sulfate was added to remove moisture, and then dichloromethane was removed by an evaporator. The obtained crude product was purified by column chromatography using a mixed solvent of dichloromethane and hexane (volume ratio: dichloromethane / hexane = 10/1) to give white solid biphenyl-4,4′-diylbis (4- ( 8 g of 5-hexenyloxy) cyphenyl) methanone were obtained.
Next, 5 g of biphenyl-4,4′-diylbis (4- (5-hexenyloxy) cyphenyl) methanone was dissolved in 100 mL of chloroform, and then 7.7 g of 3-chloroperbenzoic acid was slowly added thereto. For 48 hours with stirring. After completion of the reaction, the reaction solution was transferred to a separatory funnel and washed with 100 mL of 1N aqueous sodium hydrogen carbonate solution. After repeating this washing operation three times, magnesium sulfate was added to the organic layer to remove moisture, and the solvent was removed with an evaporator. The obtained solid was dissolved in 50 mL of dichloromethane and re-precipitated by adding it to 300 mL of hexane to obtain 4 g of an epoxy resin represented by the following formula (9).

  10 g of this epoxy resin is placed in an aluminum petri dish placed on a hot plate maintained at 180 ° C., and 1.68 g of diaminodiphenylmethane (DDM) curing agent previously dissolved in an oven at 150 ° C. is added and mixed by stirring. A uniform resin composition was prepared. This resin composition was polymerized by heating in an oven at 180 ° C. for 4 hours to obtain a homogeneous cured resin product. When the cured resin was observed using a polarizing microscope, the orientation of the polymer was confirmed.

(Example 6)
2.7 g of biphenyl-4,4′-diol, 36 g of 1,6-dibromohexane, 20 g of potassium carbonate, and 100 mL of acetone were placed in an eggplant-shaped flask and purged with nitrogen. For 24 hours to react. After completion of the reaction, acetone was removed by an evaporator, 10 mL of tetrahydrofuran was added for dilution, and this was poured into 200 mL of water. The resulting precipitate was filtered off and washed with hexane to obtain 5.3 g of 4,4′-bis (6-bromohexyloxy) biphenyl.
Next, 5 g of 4,4′-bis (6-bromohexyloxy) biphenyl, 10.7 g of hydroquinone, 13.5 g of potassium carbonate, and 100 mL of dimethylformamide were placed in a flask and reacted at 80 ° C. for 6 hours. I let you. After completion of the reaction, the reaction solution was poured into 500 mL of water. The resulting precipitate was filtered off and then recrystallized using dimethyl sulfoxide, whereby 4,4 ′-(6,6 ′-(biphenyl-4,4′-diylbis (oxy) bis (hexane-6, 2.3 g of 1-diyl) bis (oxy) diphenol was obtained.

Next, 2.3 g of 4,4 ′-(6,6 ′-(biphenyl-4,4′-diylbis (oxy) bis (hexane-6,1-diyl) bis (oxy) diphenol, 2.9 g Allyl bromide, 3.3 g of potassium carbonate, and 30 mL of acetone were placed in a flask and purged with nitrogen, followed by heating and refluxing for 6 hours with stirring, after which the acetone was removed by an evaporator. After diluting with 3 mL of tetrahydrofuran, this was poured into 100 mL of water, and the resulting precipitate was filtered off, washed with hexane, and 4,4′-bis (6- (4-allyloxy) hexyloxy). 2 g of biphenyl was obtained.
Next, 1.5 g of 4,4′-bis (6- (4-allyloxy) hexyloxy) biphenyl was dissolved in 50 mL of chloroform, and then 5 g of 3-chloroperbenzoic acid was slowly added thereto. For 48 hours with stirring. After completion of the reaction, the reaction solution was transferred to a separatory funnel and washed with 100 mL of 1N aqueous sodium hydrogen carbonate solution. After repeating this washing operation three times, magnesium sulfate was added to the organic layer to remove moisture, and the solvent was removed with an evaporator. The obtained solid was dissolved in 50 mL of dichloromethane and re-precipitated by adding it to 200 mL of hexane to obtain 1.2 g of an epoxy resin represented by the following formula (10).

  10 g of this epoxy resin is placed in an aluminum petri dish placed on a hot plate maintained at 160 ° C., and 1.45 g of diaminodiphenylmethane (DDM) curing agent previously dissolved in an oven at 150 ° C. is added and mixed by stirring. A uniform resin composition was prepared. This resin composition was polymerized by heating in an oven at 180 ° C. for 4 hours to obtain a homogeneous cured resin product. When the cured resin was observed using a polarizing microscope, the orientation of the polymer was confirmed.

(Example 7)
In the same manner as in Example 6, 4,4′-bis (6- (4-allyloxy) hexyloxy) biphenyl, which is a curing agent for epoxy resin represented by the following formula (11), was synthesized.
5 g of this epoxy resin curing agent was placed in an aluminum petri dish placed on a hot plate maintained at 160 ° C., and a phenol novolac type epoxy resin (Epicoat 154, manufactured by Japan Epoxy Resin Co., Ltd.) heated in an oven at 150 ° C. in advance. ) 3.12 g was added and mixed by stirring to prepare a uniform resin composition. This resin composition was polymerized by heating in an oven at 180 ° C. for 4 hours to obtain a homogeneous cured resin. When the cured resin was observed using a polarizing microscope, the orientation of the polymer was confirmed.

(Example 8)
After stirring and mixing 30 g of the epoxy resin of the above formula (6), 4.78 g of diaminodiphenylmethane (DDM) curing agent and 104.34 g of methyl ethyl ketone (MEK), boron nitride particles (inorganic filler, A uniform resin composition was prepared by adding 65.79 g of boron nitride particles such that Showa Denko Co., Ltd.) was 50% by volume and sufficiently stirring and mixing. The resin composition was coated on a PET film with a multi coater and dried, and then heated and polymerized at 180 ° C. for 4 hours to obtain a uniform resin cured sheet having a thickness of 100 μm. The resin composition also had good coating properties and sheet formability.

(Comparative Example 1)
A biphenyl type epoxy resin represented by the following formula (12) was synthesized by a known method.
A resin composition was prepared by heating 10 g of this biphenyl type epoxy resin to 200 ° C., adding 3.1 g of diaminodiphenylmethane curing agent (DDM) and stirring and mixing. However, the curing reaction of the epoxy resin progressed rapidly, and uniform mixing was difficult, and a uniform resin composition could not be obtained. This resin composition was heated in an oven at 200 ° C. for 4 hours for polymerization to obtain a cured resin product. When this cured resin was observed using a polarizing microscope, the orientation of the polymer was confirmed. Moreover, this cured resin was heterogeneous.

(Comparative Example 2)
After uniformly stirring and mixing 30 g of the biphenyl type epoxy resin represented by the above formula (12) and 9.3 g of diaminodiphenylmethane (DDM) curing agent, boron nitride particles in the cured resin (inorganic filler, Showa Denko) Boron nitride particles (74.34 g) were added so that 50% by volume was obtained, and 117.9 g of methyl ethyl ketone (MEK) was further added, followed by sufficient stirring and mixing to prepare a resin composition. When this resin composition was coated on a PET film with a multicoater and dried, the resin component was peeled off during drying, and a sheet of a cured resin product worthy of evaluation could not be obtained. This result is considered to be due to the fact that the biphenyl type epoxy resin used has high crystallinity and thus has low solubility in a solvent and a high melting point.

  About the resin hardened | cured material obtained in Examples 1-8 and Comparative Examples 1-2, and its sheet | seat, each resin hardened | cured material and sheet | seat were measured by the laser flash method thermal constant measuring apparatus (LF / TCM-FA8510B by Rigaku Corporation). The thermal diffusivity and specific heat in the thickness direction were measured, and the density of each cured resin and sheet was measured by an underwater substitution method. Using the obtained measured values, the thermal conductivity of each cured resin and sheet was calculated (thermal conductivity = thermal diffusivity × specific heat × density). The results are shown in Table 1.

  In Table 1, as can be seen from comparison between Examples 1 to 7 and Comparative Example 1, the compound having the predetermined flexible unit had a lower melting point than the compound not having the predetermined flexible unit. The cured resin obtained from a resin composition containing a compound having a predetermined flexible unit has a high thermal conductivity, whereas the cured resin obtained from a resin composition containing a compound not having a predetermined flexible unit. Had low thermal conductivity. Furthermore, as can be seen from a comparison between Example 8 and Comparative Example 2, the resin composition containing a compound having a predetermined flexible unit has high solubility in a solvent and can be uniformly mixed in the resin composition. Therefore, while the moldability was also good, the resin composition containing a compound that does not have a predetermined flexible unit has low solubility in a solvent and cannot be uniformly mixed in the resin composition. Sufficient moldability was not obtained.

  As can be seen from the above results, according to the present invention, a homogenous resin cured product having high electrical insulation and thermal conductivity is obtained, and a resin composition having excellent moldability, and electrical insulation and thermal conductivity. Can provide a highly uniform cured resin.

Claims (10)

A resin composition containing a liquid crystal unit containing a mesogenic group, a flexible unit bonded to both ends of the liquid crystal unit, and a terminal polymerizable group, wherein the flexible unit has the following formula:

A resin composition characterized by being one or more groups selected from the group consisting of (wherein n is an integer of 4 or more).   The resin composition according to claim 1, wherein the liquid crystal unit includes a biphenyl ester structure, a biphenyl ether structure, a biphenyl ketone structure, or a biphenylamide structure.   The resin composition according to claim 1, wherein the compound has a branched structure.   The polymerizable group is one or more groups selected from the group consisting of epoxy groups, vinyl groups, amino groups, hydroxyl groups, acryloyl groups, cyclohexene groups, methacryloyl groups, cinnamoyl groups, isocyanate groups, and dicarboxylic anhydride groups. It is a resin composition as described in any one of Claims 1-3 characterized by the above-mentioned.   The resin compound according to claim 1, wherein the compound is a monomer having a homopolymerizable group as the polymerizable group.   The said compound is an epoxy resin which has an epoxy group as said polymeric group, The resin composition as described in any one of Claims 1-3 characterized by the above-mentioned.   The said compound is a hardening | curing agent for epoxy resins which has the group which can react with an epoxy group as said polymeric group, The resin composition as described in any one of Claims 1-3 characterized by the above-mentioned.   The resin composition according to any one of claims 1 to 7, further comprising an inorganic filler.   A resin cured product obtained by polymerizing the resin composition according to claim 1.   The cured resin product according to claim 9, wherein the cured resin product is used as an insulating sheet.