JP5737129B2 - Epoxy resin, epoxy resin composition and cured product - Google Patents

Description

  In the present invention, all the unit skeletons contained in the resin are biphenyl skeletons, and have sufficient film-forming properties and elongation properties to be applied to processes such as film molding and coating, and have heat conductivity and heat resistance. The present invention relates to an epoxy resin excellent in flexibility balance. The present invention also relates to an epoxy resin composition containing the epoxy resin and a curing agent, and a cured product obtained by curing the epoxy resin composition.

  Epoxy resins are excellent in heat resistance, adhesiveness, water resistance, mechanical strength, and electrical properties, so they are used in various fields such as adhesives, paints, materials for civil engineering and construction, and insulating materials for electrical and electronic parts. It is used. In particular, in the electric / electronic field, it is widely used in insulating casting, laminated materials, sealing materials and the like.

  In recent years, multilayer circuit boards used in electrical and electronic equipment have been reduced in size, weight, and functionality, and further increased in number of layers, density, thickness, weight, reliability, and Improvements in molding processability are required.

  In connection with this, the heat dissipation of the material used has become a problem. Conventionally, the heat dissipation has been covered by the thermal conductivity of the filler. However, for further higher integration, improvement in the thermal conductivity of the epoxy resin itself as a matrix has been demanded.

  Up to now, epoxy-based high thermal conductive materials have been developed, but many of them are aimed at optimizing the composition of a composition containing a high thermal conductive filler rather than the thermal conductivity of the epoxy resin itself as a matrix. It was.

For example, in Patent Documents 1 and 2, an inorganic compound powder or fiber having high thermal conductivity is blended as a high thermal conductive filler, and an epoxy resin having a very high molecular weight is used as a general bisphenol A type epoxy resin. It does not mention the thermal conductivity of the epoxy resin itself. That is, in Patent Documents 1 and 2, the thermal conductivity is borne by the filler, and the epoxy resin only provides ease of handling as a film.
Further, Patent Document 3 characterizes the shape of the filler, and Patent Document 4 improves the decrease in adhesion and the like due to the blending of the filler by blending a high molecular weight resin compatible with the epoxy resin or a reactive high molecular weight resin. The epoxy resins that are used are very common novolac type epoxy resins and bisphenol A type epoxy resins.

  On the other hand, recently, several inventions have been disclosed that attempt to improve the thermal conductivity of the epoxy resin itself by introducing a mesogenic skeleton.

  For example, Non-Patent Document 1 describes the improvement of thermal conductivity of epoxy resins by introducing various mesogenic skeletons, but it is practical in consideration of cost, process, hydrolysis resistance and thermal stability. I can't say that.

  Patent Document 5 discloses an epoxy resin having a good thermal conductivity using only a biphenyl skeleton and having both a substituted biphenyl skeleton and an unsubstituted biphenyl skeleton.

Japanese Patent Laid-Open No. 04-339815 Japanese Patent Laid-Open No. 04-339854 Japanese Patent Laid-Open No. 05-259312 Japanese Patent Laid-Open No. 10-183086 JP 2010-001427 A

Latest technology of epoxy resin for electronic parts (CMC Publishing, 2006, Chapter 1 P24-31, Chapter 5 P114-121)

According to detailed examinations by the present inventors, only a very low molecular weight epoxy resin is actually synthesized in Patent Document 5, and since this epoxy resin lacks film forming properties, it can be used as a thin film. It was difficult. Furthermore, since the thermal conductivity of the epoxy resin alone has not been measured, it has not been clarified whether the thermal conductivity disclosed in the examples is expressed by the epoxy resin. Moreover, the hardened | cured material obtained using the epoxy resin synthesize | combined in patent document 5 is anticipated that elongation is low, an elasticity modulus is high, and flexibility is low. For this reason, when using as an actual hardened | cured material, modification | denaturation, such as adding a rubber component, is needed, and there exists a concern about the fall of the heat conductivity by modification | denaturation in that case.

Although it is known that the mesogen skeleton is excellent in thermal conductivity, there has been no epoxy resin having a mesogen skeleton that has been proposed in the past that can achieve both elongation and thermal conductivity.
Also, considering practicality, it does not require a special material composition or a special curing process, and it can be replaced by simply replacing the constituent components of epoxy resin compositions that are currently in practical use, or simply adding flexibility. It is considered that a material that improves the thermal conductivity while maintaining the cured product characteristics is required.

  On the other hand, in order to use it as an insulating layer of an electrical laminate, etc., a material excellent in process applicability such as handling and application as a film is required, but conventionally, such required characteristics have been satisfied. Above, no epoxy resin with high thermal conductivity is provided.

  In view of the above problems, the present invention has sufficient film forming properties and stretchability to be applied to processes such as film forming and coating, and various physical properties such as thermal conductivity, heat resistance, and flexibility. It is another object of the present invention to provide an epoxy resin and an epoxy resin composition excellent in the balance of cured product properties such as thermal conductivity, heat resistance, and flexibility when cured.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that all unit skeletons contained in the resin are specific biphenyl skeletons, and epoxy resins having specific epoxy equivalents are used in processes such as film molding and coating. Excellent balance of physical properties such as film-forming properties, stretchability, thermal conductivity, heat resistance, and flexibility sufficient for application, and balance of cured product properties such as thermal conductivity and flexibility I found it to be excellent.

  The present invention has been achieved on the basis of such findings, and the gist thereof is as follows.

[1] An epoxy resin represented by the following formula (1) and having an epoxy equivalent of 2,500 g / equivalent to 30,000 g / equivalent.

(In the above formula (1), A is a biphenyl skeleton represented by the following formula (2), and B is a hydrogen atom or a group represented by the following formula (3) (however, in the formula (1) N of the two Bs are not hydrogen atoms.) , N is the number of repetitions, and the average value is 1 <n <100.)

(In the above formula (2), R ¹ is a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, or a halogen element, which may be the same or different from each other . R ¹ includes both a hydrogen atom and a hydrocarbon group having 1 to 10 carbon atoms .)

[2] R ¹ in the formula (2) is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and the biphenyl skeleton represented by the formula (2) has at least one hydrogen atom and at least one carbon number. The epoxy resin according to [1], which has 1 to 4 alkyl groups.

[3] In an epoxy resin composition containing an epoxy resin component and a curing agent, the epoxy resin component includes at least the epoxy resin according to claim 1 or 2, and the epoxy resin component as a solid component. An epoxy resin composition containing 0.1 to 60% by weight based on the total amount of curing agents.

[4] A cured product obtained by curing the epoxy resin composition according to [3].

  According to the present invention, it has sufficient film forming properties and stretchability to be applied to processes such as film forming and coating, and has excellent balance of physical properties such as thermal conductivity, heat resistance, and flexibility. Provided are an epoxy resin and an epoxy resin composition excellent in the balance of cured product characteristics such as thermal conductivity, heat resistance and flexibility when cured.

DESCRIPTION OF EMBODIMENTS Embodiments of the present invention will be described in detail below. However, the description of the constituent elements described below is an example of the embodiments of the present invention, and the present invention is described below unless the gist of the present invention is exceeded. It is not limited to.
In the present specification, when the expression “to” is used, it is used as an expression including numerical values or physical property values before and after the expression.

[Epoxy resin]
The epoxy resin of the present invention is represented by the following formula (1) and has an epoxy equivalent of 2,500 g / equivalent to 30,000 g / equivalent. Hereinafter, the epoxy resin of the present invention may be referred to as “epoxy resin (1)”.

(In the above formula (1), A is a biphenyl skeleton represented by the following formula (2), and B is a hydrogen atom or a group represented by the following formula (3) (however, in the formula (1) N of the two Bs are not hydrogen atoms.) , N is the number of repetitions, and the average value is 1 <n <100.)

(In the above formula (2), R ¹ is a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, or a halogen element, which may be the same or different from each other . R ¹ includes both a hydrogen atom and a hydrocarbon group having 1 to 10 carbon atoms .)

<Action mechanism>
The epoxy resin of the present invention has sufficient film-forming properties and stretchability to be applied to processes such as film molding and coating, and has an excellent balance of thermal conductivity, heat resistance, flexibility, etc. Excellent balance of cured product characteristics.

(About stretchability)
Although the details of the reason why the epoxy resin of the present invention is excellent in elongation are not clear, it has a molecular chain length that can withstand stretching when tensile stress is applied, and in order to relieve the stress, overlapping biphenyl This is presumably because the skeletons can “slide”. In addition, at this time, if the crystallinity is too high, it is brittle and breaks without elongation. Therefore, it is important to have an appropriate amorphous portion. In the epoxy resin of the present invention, the biphenyl skeleton is substituted. By having a group, the crystallinity can be reduced moderately, which is considered to lead to the expression of elongation. Therefore, from the viewpoint of extensibility, it is preferable that R ¹ in the formula (2) is not all hydrogen atoms but one or more R ¹ is a hydrocarbon group or a halogen element.

(About thermal conductivity)
Thermal conduction is governed by phonons and conduction electrons, and when there are free electrons like metal, the contribution of conduction electrons is large, but epoxy resin is generally an insulator, and phonons are the main heat conduction in insulators. Is a factor. Since heat conduction by phonons is propagation of vibration energy, vibrations are less likely to be attenuated, and the higher the crystallinity material, the better the heat conductivity.
The details of the reason why the epoxy resin of the present invention is excellent in thermal conductivity are not clear, but since all the skeletons are biphenyl skeletons, the degree of freedom of the structure is small, vibration energy is not easily attenuated, and the biphenyl skeleton is flat. It is presumed that this is due to the good overlap between molecules and the ability to restrain molecular motion more.

(About heat resistance)
Epoxy resins tend to have better heat resistance when crystallinity is better. If the epoxy resin has the same structure, the resin having a larger molecular weight or epoxy equivalent tends to have better heat resistance. The epoxy resin of the present invention is excellent in heat resistance by having appropriate crystallinity and an epoxy equivalent size.

(About flexibility)
Since the epoxy resin of the present invention has a large epoxy equivalent, it is excellent in flexibility. Moreover, since there are few crosslinking points with respect to the whole epoxy resin also when it is set as hardened | cured material, a crosslinking density becomes low and it is excellent also in the flexibility as hardened | cured material characteristic.

<N>
In said Formula (1), n is a repeating number and is an average value. The range of the value is 1 <n <100, but is preferably more than 10, more preferably more than 15, still more preferably more than 20, and particularly preferably 25 from the balance of elongation and resin handling. Greater than, particularly preferably greater than 35, while preferably less than 80, more preferably less than 60, particularly preferably less than 50. For example, n is preferably 10 <n <80, particularly 20 <n <50, particularly 35 <n <50. If n in the formula (1) is 1 or less, the elongation does not appear at all, and if it is 100 or more, the viscosity of the epoxy resin tends to be high and handling tends to be difficult.

<A>
In the formula (1), A is a biphenyl skeleton represented by the formula (2). In the formula (2), R ¹ may be the same or different from each other, and may be a hydrogen atom, carbon 1 represents a hydrocarbon group having 1 to 10 or a halogen element, but one epoxy resin includes both a hydrogen atom and a hydrocarbon group having 1 to 10 carbon atoms as R ¹ It is preferable from the viewpoint of the whole crystallinity and handling. When R ¹ is the same, the crystallinity becomes high and the thermal conductivity can be increased. However, when the crystallinity is too high, the elongation when the epoxy resin is formed into a film tends to be small.

R ¹ in the formula (2) is a hydrocarbon group having 1 to 10 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, particularly preferably a methyl group.
The hydrocarbon group for R ¹ may have a substituent, and the substituent is not particularly limited, but has a molecular weight of 200 or less.
Further, the halogen element R ^1, fluorine element, elemental chlorine, refers to elemental bromine, which may include a plurality of kinds in only one kind.

The biphenyl skeleton of A is 2,2′-biphenyl skeleton, 2,3′-biphenyl skeleton, 2,4′-biphenyl skeleton, 3,3-biphenyl skeleton, 3,4′-biphenyl skeleton, 4,4′- Any of the biphenyl skeletons may be used, but a 4,4′-biphenyl skeleton is preferred.
The hydrogen atom as R ¹ is preferably in the 2-position and / or 6-position, and preferably has a hydrocarbon group in the 3-position and / or 5-position.

<Epoxy equivalent>
The epoxy equivalent of the epoxy resin of the present invention is 2,500 g / equivalent to 30,000 g / equivalent. The epoxy equivalent is preferably 2,500 g / equivalent or more from the viewpoint of elongation when the epoxy resin is film-formed and from the viewpoint of flexibility. The epoxy equivalent of the epoxy resin of the present invention is preferably 3,000 g / Equivalent or higher, more preferably 5,000 g / equivalent or higher. On the other hand, the epoxy equivalent is preferably 30,000 g / equivalent or less from the viewpoint of reactivity during curing, and the epoxy equivalent of the epoxy resin of the present invention is preferably 15,000 g / equivalent or less, more preferably 10,000 g / equivalent. It is below the equivalent. The epoxy equivalent of an epoxy resin is calculated | required by the method described in the term of the below-mentioned Example.

<Weight average molecular weight>
The weight average molecular weight Mw of the epoxy resin of the present invention is preferably 10,000 or more and 200,000 or less. If the weight average molecular weight is less than 10,000, the extensibility and flexibility tend to be low, and if it is higher than 200,000, the resin tends to be difficult to handle. The weight average molecular weight of an epoxy resin is calculated | required by the method described in the term of the below-mentioned Example.

<Thermal conductivity>
The thermal conductivity (thermal conductivity before curing) of the epoxy resin of the present invention is usually 0.18 W / mK or higher, preferably 0.19 W / mK or higher, more preferably 0.20 W / mK or higher. In general, the thermal conductivity of an epoxy resin is often evaluated as a cured product of an epoxy resin, and the thermal conductivity of a general uncured bisphenol A type epoxy resin is usually lower than this value and is liquid. Therefore, it is often impossible to prepare a sample for measuring elongation. The epoxy resin of the present invention has a sufficient film-forming property and thermal conductivity even in the state of the resin itself before curing, and is excellent in balance between stretchability. In addition, the heat conductivity of an epoxy resin is measured by the method described in the term of the below-mentioned Example.

<Glass transition temperature: Tg (DSC)>
The epoxy resin of the present invention has excellent heat resistance, and can be 100 ° C. or higher and 220 ° C. or lower when evaluated by the glass transition temperature Tg (DSC) shown in the Examples section below. The Tg (DSC) of the epoxy resin is preferably higher in applications using the epoxy resin of the present invention described later, preferably 105 ° C. or higher, more preferably 115 ° C. or higher, still more preferably 120 ° C. or higher. If the (DSC) is too high, the curing reaction does not proceed sufficiently at the heating temperature used in the processing process, the quality may not be stable, and the required physical properties may not be exhibited. Usually, it is preferably 200 ° C.

<Manufacturing method>
The epoxy resin of the present invention can be obtained, for example, by a two-stage method in which a bifunctional epoxy resin (X) having a biphenyl skeleton and a biphenol compound (Y) are reacted. It can also be obtained by a one-step method in which one or more biphenol compounds (Y) and epichlorohydrin are directly reacted. However, since the biphenol compound (Y) is not good in solvent solubility, a solvent generally used in the one-step method may not be applicable, and therefore, the two-step method is preferably used.

  The bifunctional epoxy resin (X) used for the production of the epoxy resin of the present invention is a compound having a biphenyl skeleton and having two epoxy groups in the molecule, and is represented by the following formula (5). Examples of the bifunctional epoxy resin (X) include an epoxy resin obtained by reacting a biphenol compound represented by the following formula (4) with epihalohydrin.

(In the above formula (4), ^{R 2} has the same meaning as ^{R 1} in formula (2), also in the above formula (5), R ^{2 'has} the same meaning as ^{R 1} to definitive formula (2).)

  Examples of the biphenol compound represented by the formula (4) include 2,2′-biphenol, 2,3′-biphenol, 2,4′-biphenol, 3,3′-biphenol, and 3,4′-biphenol. 4,4′-biphenol, 2-methyl-4,4′-biphenol, 3-methyl-4,4′-biphenol, 2,2′-dimethyl-4,4′-biphenol, 3,3′-dimethyl -4,4'-biphenol, 3,3 ', 5,5'-tetramethyl-4,4'-biphenol, 2,2', 3,3 ', 5,5'-hexamethyl-4,4'- Biphenol, 2,2 ′, 3,3 ′, 5,5 ′, 6,6′-octamethyl-4,4′-biphenol and the like can be mentioned. Among these, 4,4′-biphenol, 3,3′-dimethyl-4,4′-biphenol, 3,3 ′, 5,5′-tetramethyl-4,4′-biphenol are preferable. . In conducting the condensation reaction with epihalohydrin, these biphenol compounds may be used alone or in combination of two or more. Moreover, bifunctional epoxy resin (X) obtained by condensing such a biphenol compound and epihalohydrin can also be used together.

  As the bifunctional epoxy resin (X), a bifunctional epoxy resin (X) having a hydrolysis chlorine concentration as an end group impurity of 200 ppm or less and an α glycol group concentration of 100 meq / kg or less is used as a raw material. Is preferred. When the hydrolyzed chlorine concentration is higher than 200 ppm or when the α glycol group concentration is higher than 100 meq / kg, it is not preferable because the molecular weight is not sufficiently increased.

  On the other hand, the biphenol compound (Y) is a compound in which two hydroxyl groups are bonded to the biphenyl skeleton, and is represented by the formula (4). As the biphenol compound (Y), as described above, for example, 2,2′-biphenol, 2,3′-biphenol, 2,4′-biphenol, 3,3′-biphenol, 3,4′-biphenol, 4 , 4′-biphenol, 2-methyl-4,4′-biphenol, 3-methyl-4,4′-biphenol, 2,2′-dimethyl-4,4′-biphenol, 3,3′-dimethyl-4 , 4′-biphenol, 3,3 ′, 5,5′-tetramethyl-4,4′-biphenol, 2,2 ′, 3,3 ′, 5,5′-hexamethyl-4,4′-biphenol, 2,2 ′, 3,3 ′, 5,5 ′, 6,6′-octamethyl-4,4′-biphenol and the like. Among these, 4,4′-biphenol, 3,3′-dimethyl-4,4′-biphenol, 3,3 ′, 5,5′-tetramethyl-4,4′-biphenol are preferable. . These biphenol compounds can be used in combination.

  The biphenyl skeleton contained in the bifunctional epoxy resin (X) and the biphenol compound (Y) is preferably not unsubstituted at the same time, and preferably has one or more substituents in one molecule. When all are unsubstituted biphenyl skeletons, the resulting epoxy resin has high crystallinity and tends to have poor elongation.

  In the production of the epoxy resin of the present invention, the above-mentioned bifunctional epoxy resin (X) and biphenol compound (Y) are used in an equivalent ratio of epoxy group: phenolic hydroxyl group = 1: 0.90-1. 10 is preferable. When the equivalent ratio is in the above range, the molecular weight can be sufficiently increased.

  A catalyst may be used for the synthesis of the epoxy resin of the present invention, and any catalyst may be used as long as it has a catalytic ability to promote a reaction between an epoxy group and a phenolic hydroxyl group, an alcoholic hydroxyl group or a carboxyl group. Something like that. For example, alkali metal compounds, organic phosphorus compounds, tertiary amines, quaternary ammonium salts, cyclic amines, imidazoles and the like can be mentioned.

  Specific examples of the alkali metal compound include alkali metal hydroxides such as sodium hydroxide, lithium hydroxide and potassium hydroxide, alkali metal salts such as sodium carbonate, sodium bicarbonate, sodium chloride, lithium chloride and potassium chloride, sodium Examples include alkali metal alkoxides such as methoxide and sodium ethoxide, alkali metal phenoxides, alkali metal hydrides such as sodium hydride and lithium hydride, and alkali metal salts of organic acids such as sodium acetate and sodium stearate.

  Specific examples of the organic phosphorus compound include tri-n-propylphosphine, tri-n-butylphosphine, triphenylphosphine, tetramethylphosphonium bromide, tetramethylphosphonium iodide, tetramethylphosphonium hydroxide, Trimethylcyclohexylphosphonium chloride, trimethylcyclohexylphosphonium bromide, trimethylbenzylphosphonium chloride, trimethylbenzylphosphonium bromide, tetraphenylphosphonium bromide, triphenylmethylphosphonium bromide, triphenylmethylphosphonium iodide, triphenylethylphosphonium chloride, triphenylethylphosphonium bromide, Triphenylethylphosphonium iodai , Triphenyl benzyl phosphonium chloride, triphenyl benzyl phosphonium bromide and the like.

  Specific examples of the tertiary amine include triethylamine, tri-n-propylamine, tri-n-butylamine, triethanolamine, benzyldimethylamine and the like.

  Specific examples of the quaternary ammonium salt include tetramethylammonium chloride, tetramethylammonium bromide, tetramethylammonium hydroxide, triethylmethylammonium chloride, tetraethylammonium chloride, tetraethylammonium bromide, tetraethylammonium iodide, tetrapropylammonium bromide, Tetrapropylammonium hydroxide, tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium iodide, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethylammonium hydroxide, benzyltributylammonium chloride Id, and a phenyl trimethyl ammonium chloride.

  Specific examples of cyclic amines include 1,8-diazabicyclo (5,4,0) undecene-7,1,5-diazabicyclo (4,3,0) nonene-5.

  Specific examples of imidazoles include 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole and the like.

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

  The amount of catalyst used is usually 0.001 to 1% by weight in the solid content of the reaction. However, when an alkali metal compound is used, the alkali metal component remains in the epoxy resin obtained, and insulation of the printed wiring board using it. Since the properties tend to deteriorate, the total content of Li, Na and K in the epoxy resin needs to be 60 ppm or less, preferably 50 ppm or less.

  In addition, when organophosphorus compounds, tertiary amines, quaternary ammonium salts, cyclic amines, imidazoles, etc. are used as catalysts, these remain as catalyst residues in the resulting epoxy resin, and the alkali metal content Since the insulating properties of the printed wiring board may be deteriorated as well as the residual, the nitrogen content in the epoxy resin needs to be 300 ppm or less, and the phosphorus content in the epoxy resin needs to be 300 ppm or less. More preferably, the content of nitrogen in the epoxy resin is 200 ppm or less, and the content of phosphorus in the epoxy resin is 200 ppm or less.

  The epoxy resin of the present invention may use a solvent in the step of the synthesis reaction at the time of production, and any solvent may be used as long as it dissolves the epoxy resin. For example, aromatic solvents, ketone solvents, amide solvents, glycol ether solvents and the like can be mentioned.

Specific examples of the aromatic solvent include benzene, toluene, xylene and the like.
Specific examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, 2-heptanone, 4-heptanone, 2-octanone, cyclohexanone, acetylacetone, and dioxane.
Specific examples of the amide solvent include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, 2-pyrrolidone, N-methylpyrrolidone and the like.
Specific examples of glycol ether solvents include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol Examples include mono-n-butyl ether, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol mono-n-butyl ether, propylene glycol monomethyl ether acetate.

  These solvents may be used alone or in combination of two or more.

The solid concentration in the synthesis reaction during the production of the epoxy resin is preferably 35 to 95% by weight.
Further, when a highly viscous product is produced during the reaction, the reaction can be continued by adding an additional solvent. After completion of the reaction, the solvent can be removed or further added as necessary.

  In the production of the epoxy resin, the polymerization reaction between the bifunctional epoxy resin (X) and the biphenol compound (Y) is carried out at a reaction temperature at which the used catalyst is not decomposed. If the reaction temperature is too high, the produced epoxy resin may be deteriorated. Conversely, if the temperature is too low, the reaction may not proceed sufficiently. For these reasons, the reaction temperature is preferably 50 to 230 ° C, more preferably 120 to 200 ° C. Moreover, reaction time is 1 to 12 hours normally, Preferably it is 3 to 10 hours. When using a low boiling point solvent such as acetone or methyl ethyl ketone, the reaction temperature can be ensured by carrying out the reaction under high pressure using an autoclave.

[Epoxy resin composition]
The epoxy resin composition of the present invention contains at least the above-described epoxy resin of the present invention as an epoxy resin component, that is, the epoxy resin (1) and a curing agent, and is excellent in thermal conductivity and required for various applications. Gives a cured product that sufficiently satisfies various physical properties.
The epoxy resin composition of the present invention may contain only the epoxy resin (1) as an epoxy resin component, and an epoxy resin other than the epoxy resin (1) together with the epoxy resin (1) (hereinafter “other epoxy resin”). May be referred to as “.”.

<Action mechanism>
The design philosophy of high thermal conductivity epoxy resin reported so far is that molecules (chains) are spontaneously oriented by utilizing the interaction between mesogenic sites, or molecules containing mesogens by applying an external magnetic field ( The main purpose was to improve thermal conductivity by reducing phonon scattering by orienting the chain. For this reason, almost all conventional high thermal conductivity epoxy resins are epoxy resins designed to increase thermal conductivity, and there are many limitations in the curing process including curing conditions, and the degree of freedom in selection is high. It was low. For this reason, when it is going to apply the conventional high heat conductive epoxy resin to products, such as a member, a sealing agent, and an adhesive agent, it was very difficult to make the required physical property of a product and high heat conductivity compatible.

  On the other hand, since the epoxy resin (1) of the present invention is excellent in thermal conductivity itself and can add the desired amount as an epoxy resin component, the thermal conductivity of the cured product can be increased. It is possible to provide the epoxy resin composition of the present invention capable of satisfying both required physical properties and high thermal conductivity.

<Other epoxy resins>
The epoxy resin composition of the present invention can contain other epoxy resins in addition to the epoxy resin (1) of the present invention.
The other epoxy resin preferably has two or more epoxy groups in the molecule. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene type epoxy resin, phenol novolac type epoxy resin, Various epoxy resins such as a cresol novolac type epoxy resin, a phenol aralkyl type epoxy resin, a biphenyl type epoxy resin, a triphenylmethane type epoxy resin, and a dicyclopentadiene type epoxy resin can be used.
These can be used alone or as a mixture of two or more.

<Curing agent>
A curing agent is blended in the epoxy resin composition of the present invention.
The curing agent in the present invention refers to a substance that contributes to a crosslinking reaction between epoxy groups of an epoxy resin.

  There is no restriction | limiting in particular as a hardening | curing agent used for this invention, What is generally known as an epoxy resin hardening | curing agent can be used. For example, phenolic curing agents, aliphatic amines, polyether amines, alicyclic amines, aromatic amines and other amine curing agents, acid anhydride curing agents, amide curing agents, tertiary amines, imidazoles, Organic phosphines, phosphonium salts, tetraphenylboron salts, organic acid dihydrazides, boron halide amine complexes, polymercaptan curing agents, isocyanate curing agents, block isocyanate curing agents, and the like.

  Specific examples of the phenolic curing agent include bisphenol A, bisphenol F, 4,4′-dihydroxydiphenylmethane, 4,4′-dihydroxydiphenyl ether, 1,4-bis (4-hydroxyphenoxy) benzene, 1,3- Bis (4-hydroxyphenoxy) benzene, 4,4′-dihydroxydiphenyl sulfide, 4,4′-dihydroxydiphenyl ketone, 4,4′-dihydroxydiphenyl sulfone, 4,4′-dihydroxybiphenyl, 2,2′-dihydroxy Biphenyl, 10- (2,5-dihydroxyphenyl) -10H-9-oxa-10-phosphaphenanthrene-10-oxide, phenol novolak, bisphenol A novolak, o-cresol novolak, m-cresol novolak, p- The Zole novolak, xylenol novolak, poly-p-hydroxystyrene, hydroquinone, resorcin, catechol, t-butylcatechol, t-butylhydroquinone, fluoroglycinol, pyrogallol, t-butyl pyrogallol, allylated pyrogallol, polyallylated pyrogallol, 1, 2,4-benzenetriol, 2,3,4-trihydroxybenzophenone, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxy Naphthalene, 1,7-dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,4-dihydroxynaphthalene, 2,5-dihydroxynaphthalene, 2 Examples include 6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2,8-dihydroxynaphthalene, allylated or polyallylated dihydroxynaphthalene, allylated bisphenol A, allylated bisphenol F, allylated phenol novolak, allylated pyrogallol, etc. Is done.

  Specific examples of the amine curing agent include aliphatic diamines such as ethylenediamine, 1,3-diaminopropane, 1,4-diaminopropane, hexamethylenediamine, 2,5-dimethylhexamethylenediamine, trimethylhexamethylenediamine, Examples include diethylenetriamine, iminobispropylamine, bis (hexamethylene) triamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, N-hydroxyethylethylenediamine, tetra (hydroxyethyl) ethylenediamine, and the like. Examples of polyether amines include triethylene glycol diamine, tetraethylene glycol diamine, diethylene glycol bis (propylamine), polyoxypropylene diamine, polyoxypropylene triamines, and the like. Cycloaliphatic amines include isophorone diamine, metacene diamine, N-aminoethylpiperazine, bis (4-amino-3-methyldicyclohexyl) methane, bis (aminomethyl) cyclohexane, 3,9-bis (3-amino). Propyl) -2,4,8,10-tetraoxaspiro (5,5) undecane, norbornenediamine and the like. Aromatic amines include tetrachloro-p-xylenediamine, m-xylenediamine, p-xylenediamine, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, 2,4-diaminoanisole, 2,4 -Toluenediamine, 2,4-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diamino-1,2-diphenylethane, 2,4-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, m-aminophenol, m-aminobenzylamine, benzyldimethylamine, 2-dimethylaminomethyl) phenol, triethanolamine, methylbenzylamine, α- (m-aminophenyl) ethylamine, α- (p-aminophenyl) ethylamine , Diaminodiethyl Examples include rudimethyldiphenylmethane, α, α'-bis (4-aminophenyl) -p-diisopropylbenzene.

  Specific examples of acid anhydride curing agents include dodecenyl succinic anhydride, polyadipic acid anhydride, polyazeline acid anhydride, polysebacic acid anhydride, poly (ethyloctadecanedioic acid) anhydride, poly (phenylhexadecanedioic acid) Anhydride, Methyltetrahydrophthalic anhydride, Methylhexahydrophthalic anhydride, Hexahydrophthalic anhydride, Methylhymic anhydride, Tetrahydrophthalic anhydride, Trialkyltetrahydrophthalic anhydride, Methylcyclohexene dicarboxylic anhydride, Methylcyclohexene tetracarboxylic Acid anhydride, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, ethylene glycol bistrimellitic dianhydride, het anhydride, nadic anhydride, methyl nadic anhydride, 5- ( 2, -Dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexane-1,2-dicarboxylic anhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene-2-succinic acid Examples of the anhydride include 1-methyl-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride.

  Examples of the amide type curing agent include dicyandiamide and polyamide resin.

  Examples of the tertiary amine include 1,8-diazabicyclo (5,4,0) undecene-7, triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris (dimethylaminomethyl) phenol. .

  Examples of imidazoles include 2-phenylimidazole, 2-ethyl-4 (5) -methylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1 -Cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino- 6- [2′-Methylimidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino-6- [2′-ethyl-4′-methylimidazolyl- (1 ′)]-ethyl-s -Triazine, 2,4-diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl s-Triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and epoxy resin and the above imidazoles And adducts are exemplified.

  Examples of organic phosphines include tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine, phenylphosphine and the like, and phosphonium salts include tetraphenylphosphonium / tetraphenylborate, tetraphenylphosphonium / ethyltriphenylborate, Examples include tetrabutylphosphonium / tetrabutylborate, and examples of the tetraphenylboron salt include 2-ethyl-4-methylimidazole / tetraphenylborate, N-methylmorpholine / tetraphenylborate, and the like.

  These curing agents may be used alone or in a combination of two or more in any combination and ratio.

[Inorganic filler]
The epoxy resin composition of the present invention may contain an inorganic filler, and by including the inorganic filler, it is possible to further improve the thermal conductivity.

  The inorganic filler used in the present invention preferably has high thermal conductivity, and the inorganic filler is preferably a high thermal conductive inorganic filler having a thermal conductivity of 1 W / m · K or more, preferably 2 W / m · K or more. .

As the inorganic filler, alumina (Al ₂ O ₃ : thermal conductivity 30 W / m · K), aluminum nitride (AlN: thermal conductivity 260 W / m · K), boron nitride (BN: thermal conductivity 3 W / m · K) K (thickness direction), 275 W / m · K (in-plane direction)), silicon nitride (Si ₃ N ₄ : thermal conductivity 23 W / m · K), silica (SiO ₂ : thermal conductivity 1.4 W / m · K) and the like. Among them, Al ₂ O ₃ , AlN, BN, and SiO ₂ are preferable, and Al ₂ O ₃ , BN, and SiO ₂ are particularly preferable.

If the inorganic filler is too granular, voids tend to remain in the cured product, and if it is too small, it tends to agglomerate and dispersibility, so if it is a granular or flat inorganic filler, It is preferable to use those having an average particle size of about 0.05 to 1000 μm.
Moreover, in the case of an agglomerated inorganic filler, it is preferable to use one having an average crystal diameter of 0.01 μm to 5 μm and an average aggregate diameter of 1 to 1000 μm.

  These inorganic fillers may be used alone or in a combination of two or more in any combination and ratio.

[solvent]
The epoxy resin composition of the present invention may be blended with a solvent in order to appropriately adjust the viscosity of the epoxy resin composition during handling during coating film formation.

  Examples of the solvent that can be contained in the epoxy resin composition of the present invention include ketones such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, cyclohexanone, esters such as ethyl acetate, ethers such as ethylene glycol monomethyl ether, N, Examples thereof include amides such as N-dimethylformamide and N, N-dimethylacetamide, alcohols such as methanol and ethanol, alkanes such as hexane and cyclohexane, and aromatics such as toluene and xylene.

  These solvents may be used alone or in a combination of two or more in any combination and ratio.

[Other additives]
The epoxy resin composition of the present invention may contain various additives for the purpose of further improving its functionality.

  Such other additives include coupling agents such as silane coupling agents and titanate coupling agents as additive components for improving the adhesion to the substrate and the adhesion between the matrix resin and the inorganic filler. UV protection agent for improving storage stability, antioxidant, plasticizer, flux for removing oxide film of solder, flame retardant, colorant, dispersant, emulsifier, low elasticity agent, diluent, antifoam Agents, ion trapping agents and the like.

  Here, as the silane coupling agent, epoxy silane such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ, -Aminopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, γ-aminopropyltrimethoxysilane, γ-ureidopropyltri Aminosilane such as ethoxysilane, mercaptosilane such as 3-mercaptopropyltrimethoxysilane, p-styryltrimethoxysilane, vinyltrichlorosilane, vinyltris (β-methoxyethoxy) silane, vinyltrimethoxysilane, vinyltriethoxysila And vinyl silanes such as γ-methacryloxypropyltrimethoxysilane, and epoxy, amino and vinyl polymer type silanes.

  On the other hand, titanate coupling agents include isopropyl triisostearoyl titanate, isopropyl tri (N-aminoethyl / aminoethyl) titanate, diisopropyl bis (dioctyl phosphate) titanate, tetraisopropyl bis (dioctyl phosphite) titanate, tetraoctyl bis ( Ditridecyl phosphite) titanate, tetra (2,2-diallyloxymethyl-1-butyl) bis (ditridecyl) phosphite titanate, bis (dioctyl pyrophosphate) oxyacetate titanate, bis (dioctyl pyrophosphate) ethylene titanate It is done.

  Any of these may be used alone or in a combination of two or more in any combination and ratio.

<Composition composition>
In the epoxy resin composition of the present invention, the epoxy resin component may be composed only of the epoxy resin (1), or may be composed of the epoxy resin (1) and another epoxy resin. In the epoxy resin composition of the present invention, the proportion of the epoxy resin (1) in the total epoxy resin component as a solid content is usually 1 to 100% by weight, preferably 1 to 99% by weight, more preferably 5 to 95% by weight. %. When the proportion of the epoxy resin (1) is 1% by weight or more, the effect of improving the thermal conductivity by blending the epoxy resin (1) can be sufficiently obtained, and the desired high thermal conductivity can be obtained. it can. When the proportion of the epoxy resin (1) is 99% by weight or less and the other epoxy resin is 1% by weight or more, the blending effect of the other epoxy resin is exhibited, and the curability and physical properties of the cured product are sufficient. Become. In the present invention, the “solid content” means a component excluding a solvent that volatilizes at room temperature (20 ° C.), and includes not only a solid but also a semi-solid or viscous liquid.
Moreover, content of the hardening | curing agent in the epoxy resin composition of this invention is 0.1 to 60 weight% with respect to the sum total of all the epoxy resin components and hardening | curing agents as solid content.

When the curing agent is a phenolic curing agent, an amine curing agent, or an acid anhydride curing agent, the equivalent ratio of the epoxy group in the epoxy resin to the functional group in the curing agent is in the range of 0.8 to 1.5. It is preferable to use so that it becomes. Outside this range, unreacted epoxy groups and functional groups of the curing agent may remain, and desired physical properties may not be obtained.
Curing agents are amide-based curing agents, tertiary amines, imidazoles, organic phosphines, phosphonium salts, tetraphenyl boron salts, organic acid dihydrazides, boron halide amine complexes, polymercaptan-based curing agents, isocyanate-based curing agents. In the case of a block isocyanate-based curing agent or the like, it is preferably used in the range of 0.1 to 20% by weight with respect to the total of all epoxy resin components and the curing agent as a solid content in the epoxy resin composition.

When the epoxy resin composition of the present invention contains an inorganic filler, the blending ratio of the inorganic filler is the total solid content in the epoxy resin composition (usually, the total solid content in the epoxy resin composition is in the resin composition). 5 to 98% by weight, more preferably 10 to 95% by weight, and the volume ratio in the cured product obtained by curing this epoxy resin composition. Preferably it is 10-90 volume%, More preferably, it is 15-85 volume%.
When the blending amount of the inorganic filler is not less than the above lower limit value, the effect of improving the thermal conductivity by blending the inorganic filler becomes sufficient, the desired high thermal conductivity can be obtained, and the above upper limit value. By being below, favorable characteristics can be obtained without impairing the film formability, adhesiveness, and cured product.

  In the epoxy resin composition of the present invention, as described above, the solvent is used in order to ensure the handleability and workability in the molding of the epoxy resin composition, and the amount used is not particularly limited.

  Moreover, there is no restriction | limiting in particular in the compounding quantity of another additive, It is used with the compounding quantity of a normal resin composition to such an extent that required functionality is obtained.

  In addition, it is preferable that the addition amount of a coupling agent shall be about 0.1 to 2.0 weight% with respect to the total solid in an epoxy resin composition among other additives. If the amount of the coupling agent is small, the effect of improving the adhesion between the matrix resin and the inorganic filler due to the incorporation of the coupling agent cannot be obtained sufficiently. The agent may bleed out.

[Cured product]
The cured product of the present invention is obtained by curing the above-described epoxy resin composition of the present invention, and has an excellent balance of extensibility, thermal conductivity, and heat resistance, and exhibits excellent cured product characteristics. Since the hardened | cured material of this invention has said outstanding hardened | cured material characteristic, it is useful for the various uses described below.

[Usage]
The epoxy resin and the epoxy resin composition of the present invention have sufficient elongation to be applied to processes such as film molding and coating, and are excellent in balance between thermal conductivity and heat resistance, and also have cured product characteristics. It is excellent and can be applied to various fields such as adhesives, paints, materials for civil engineering and construction, insulating materials for electrical and electronic parts, especially insulating casting, laminating materials and sealing materials in the electrical and electronic fields. Useful as such.
Examples of uses of the epoxy resin and the epoxy resin composition of the present invention include multilayer printed wiring boards, film adhesives, liquid adhesives, semiconductor sealing materials, underfill materials, 3D-LSI interchip fills, and insulating sheets. , Prepreg, heat dissipation substrate, etc. are mentioned, but it is not limited to these.

EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example, this invention is not limited at all by the following example. In addition, the values of various production conditions and evaluation results in the following examples are meaningful as preferred values of the upper limit or lower limit in the embodiment of the present invention, and the preferred range is the above-described upper limit or lower limit value, It may be a range defined by a combination of values of the following examples or values of the examples.
In the following, all “parts” indicate “parts by weight”.
Moreover, the measuring method of the various characteristics below is as follows.

[Measurement method of characteristics]
<Molecular weight>
Using a high-speed gel permeation chromatography (GPC) apparatus (HLC-8320GPC EcoSEC (registered trademark) manufactured by Tosoh Corporation), TSK Standard Polystyrene: F-128 (Mw1,090) as standard polystyrene under the following measurement conditions , 000, Mn 1,030,000), F-10 (Mw 106,000, Mn 103,000), F-4 (Mw 43,000, Mn 42,700), F-2 (Mw 17,200, Mn 16,900), A A calibration curve using −5000 (Mw 6,400, Mn 6,100), A-2500 (Mw 2,800, Mn 2,700), A-300 (Mw 453, Mn 387) was prepared, and the weight average molecular weight and number average molecular weight were determined. It measured as a polystyrene conversion value.
Column: “TSKGEL SuperHM-H + H5000 + H4000 + H3000 + H2000” manufactured by Tosoh Corporation
Eluent: Tetrahydrofuran Flow rate: 0.5 ml / min Detection: UV (wavelength 254 nm)
Temperature: 40 ° C
Sample concentration: 0.1% by weight
Injection volume: 10 μl

<N number>
The value of n and the average value in the formula (1) were calculated from the number average molecular weight determined above.

<Epoxy equivalent>
Measured according to JIS K 7236 and expressed as a solid content converted value.

<Glass transition temperature of epoxy resin: Tg (DSC)>
The epoxy resin from which the solvent was removed by drying was measured using a differential scanning calorimeter “DSC7020” manufactured by SII NanoTechnology Co., Ltd., heated to 30 to 200 ° C. at 10 ° C./min.

<Elongation>
The epoxy resin solution was applied to a separator (silicone-treated polyethylene terephthalate film, thickness: 100 μm) with an applicator and dried under the following conditions a or b to obtain an epoxy resin film having a thickness of about 50 μm.
a: 1 hour at 60 ° C., then 1 hour at 150 ° C., then 1 hour at 200 ° C. b: 2 hours at 150 ° C., then 1 hour at 200 ° C. The average value measured three times at 5 mm / min using Ron's INSTRON 5582 type) is shown.

<Thermal conductivity>
Epoxy resin solutions (Examples 1-1 to 1-3 and Comparative Example 1-1) or epoxy resin compositions (Examples 2-1 to 2-5, Comparative Example 2-1, Examples 3-1 to 3) -3 and Comparative Example 3-1) were applied to a separator (silicone-treated polyethylene terephthalate film, thickness: 100 μm) with a doctor blade.
The epoxy resin solution was heat-dried under the following conditions a or b to obtain an epoxy resin film having a thickness of about 50 μm (Examples 1-1 to 1-3 and Comparative Example 1-1).
a: 1 hour at 60 ° C., then 1 hour at 150 ° C., and further 1 hour at 200 ° C. b: 2 hours at 150 ° C., then 1 hour at 200 ° C. For the epoxy resin composition, Or it hardened by heating on the conditions of b, and obtained the film of the hardened | cured material of thickness about 50 micrometers (Example 2-1 to 2-5, Comparative example 2-1, Examples 3-1 to 3-3. And Comparative Example 3-1).
About these films, the thermal diffusivity, specific gravity, and specific heat were measured with the following apparatus, and the thermal conductivity was calculated | required by multiplying these three measured values.
Thermal diffusivity: Eye phase "eye phase mobile 1u"
Specific gravity: METTLER TOLEDO Co., Ltd. “Balance XS-204” (using “Solid Specific Gravity Measurement Kit”)
Specific heat: Seiko Instruments Inc. "DSC320 / 6200"

<Glass transition temperature of cured product: Tg (DMA) and storage elastic modulus E ′>
The glass transition temperature Tg (DMA) and the elastic modulus at 30 ° C. and 200 ° C. of the obtained cured film were measured with a dynamic viscoelasticity measuring device (DMA). The values of storage elastic modulus E ′ and loss elastic modulus E ″ are obtained by dynamic viscoelasticity measurement. The glass transition temperature Tg (DMA) was determined from the maximum value of the loss tangent tan δ (= E ″ / E ′). Moreover, the value of the storage elastic modulus E ′ was used for the elastic modulus at 30 ° C. and 200 ° C.
The higher the glass transition temperature Tg (DMA), the better the heat resistance, and the lower the elastic modulus (storage elastic modulus E ′), the better the flexibility.
The measurement conditions for the dynamic viscoelasticity measurement are as follows.
Apparatus: TASA Corporation RSAIII
Measurement temperature range: 30 ° C to 200 ° C
Tensile load: 100 mN (initial static load)
Frequency: 1Hz
Temperature increase rate: 2 ° C / min Sample width: 3mm
Distance between spans: 20mm

[Production and evaluation of epoxy resin]
<Examples 1-1 to 1-3 and Comparative Example 1-1>
The compound (X), the compound (Y), the catalyst and the reaction solvent were put in a pressure-resistant reaction vessel equipped with a stirrer with the formulation shown in Table 1 and reacted at 180 ° C. for 5 hours in a nitrogen gas atmosphere. Solvent was added to adjust the solid content concentration. After removing the solvent from the reaction product by a conventional method, the obtained resin was analyzed. The results are shown in Table-1.

  The compounds, catalysts and solvents used for the reaction are as follows.

<Compound (X)>
(X-A): Mitsubishi Chemical Corporation product name “YL6121H” (4,4′-biphenol type epoxy resin and 3,3 ′, 5,5′-tetramethyl-4,4′-biphenol type epoxy resin) 1: 1 mixture, epoxy equivalent 171 g / equivalent)
(X-B): Mitsubishi Chemical Corporation product name “YX4000” (3,3 ′, 5,5′-tetramethyl-4,4′-biphenoldiglycidyl ether, epoxy equivalent 186 g / equivalent)

<Compound (Y)>
(YA): 3,3′-dimethyl-4,4′-biphenol (OH equivalent 107 g / equivalent, Honshu Chemical Co., Ltd.)
(YB): 3,3 ′, 5,5′-tetramethyl-4,4′-biphenol (OH equivalent 121 g / equivalent)
(Y-C): 4,4′-biphenol (OH equivalent 93 g / equivalent)

<Catalyst>
(C-1): 27 wt% tetramethylammonium hydroxide aqueous solution (C-2): 50 wt% tetramethylammonium chloride aqueous solution

<Solvent>
(S-1): Cyclohexanone (S-2): Methyl ethyl ketone

[Production and evaluation of epoxy resin composition]
<Example 2-1>
2.5 g of epoxy resin (Mw59,741) obtained in Example 1-1 (resin solid content: 0.75 g; 60 parts by weight) and bisphenol A novolac type polyfunctional epoxy resin 80% by weight MEK solution (Mitsubishi Chemical) (Trade name "157S65B80)") 0.625 g (resin solid content 0.5 g; 40 parts by weight) and 2-ethyl-4 (5) -methylimidazole (manufactured by Mitsubishi Chemical Corporation) as a curing agent 0.032 g (curing agent weight 0.00625 g; 0.5 parts by weight) of a 20 wt% solution (trade name “EMI24”) (solvent MEK) was weighed and stirred and mixed and defoamed with a rotating and rotating mixer. About this epoxy resin composition, the cured film was produced by the above-mentioned method, and the heat conductivity was calculated | required. The results are shown in Table-2.

<Examples 2-2 to 2-5, Comparative Example 2-1, Examples 3-1 to 3-3, and Comparative Example 3-1>
An epoxy resin composition was produced in the same manner as in Example 2-1, except that the composition of the epoxy resin composition was changed as shown in Table-2 or Table-3, and the curing shown in Table-2 or Table-3. A cured film was obtained under the conditions. In the same manner as in Example 2-1, the thermal conductivity was measured by the above-described method. Examples 3-1 to 3-3 and Comparative Example 3-1 were further subjected to the glass transition temperature Tg ( TMA), and storage elastic modulus E ′ at 30 ° C. and 200 ° C., respectively.

In addition, the meanings of the abbreviations in “Other Epoxy Resins” and “Curing Agents” in Table-2 and Table-3 are as follows.
-Other epoxy resin "1256B40": Mitsubishi Chemical Corporation bisphenol A type epoxy resin 40 wt% MEK solution "157S65B80": Mitsubishi Chemical Corporation bisphenol A novolak type polyfunctional epoxy resin 80 wt% MEK solution "NC -3000-H ": Nippon Kayaku Co., Ltd. biphenyl type polyfunctional epoxy resin" NC-3000 ": Nippon Kayaku Co., Ltd. biphenyl type polyfunctional epoxy resin and curing agent" EMI24 ": Mitsubishi Chemical Corporation 2-Ethyl-4 (5) -methylimidazole

From the results shown in Table 1, the epoxy resins of Examples 1-1 to 1-3 were compared with the epoxy resin of Comparative Example 1-1 (epoxy resin similar to Example 1 of JP 2010-001427 A). It can be seen that the film-forming property, elongation property, and heat resistance are excellent.
Moreover, it turns out from the result of Table-2 that the epoxy resin of Examples 2-1 to 2-5 is more excellent in thermal conductivity than Comparative Example 2-1.
Furthermore, from the result of Table-3, although the epoxy resins of Examples 3-1 to 3-3 have a rigid skeleton than the epoxy resin of Comparative Example 3-1, the cured product is It turns out that it has the same flexibility and thermal conductivity is superior to that of Comparative Example 3-1.

  From the above results, it can be seen that the epoxy resin of the present invention has sufficient film formability and stretchability to be applied to processes such as film molding and coating, and is excellent in balance between thermal conductivity and heat resistance. . Moreover, the elastic modulus of the cured product obtained from the epoxy resin of the present invention is equivalent to that of the comparative example, and while maintaining flexibility, it is only necessary to replace existing materials without requiring a special material composition or curing process. It can be seen that the thermal conductivity can be improved.

Claims (4)

An epoxy resin represented by the following formula (1) and having an epoxy equivalent of 2,500 g / equivalent to 30,000 g / equivalent.

(In the above formula (1), A is a biphenyl skeleton represented by the following formula (2), and B is a hydrogen atom or a group represented by the following formula (3) (however, in the formula (1) N of the two Bs are not hydrogen atoms.) , N is the number of repetitions, and the average value is 1 <n <100.)

(In the above formula (2), R ¹ is a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, or a halogen element, which may be the same or different from each other . R ¹ includes both a hydrogen atom and a hydrocarbon group having 1 to 10 carbon atoms .)

R ¹ in the formula (2) is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and the biphenyl skeleton represented by the formula (2) has at least one hydrogen atom and at least one carbon atom having 1 to 4 carbon atoms. The epoxy resin of Claim 1 which has the alkyl group of these.   In the epoxy resin composition containing an epoxy resin component and a curing agent, the epoxy resin component includes at least the epoxy resin according to claim 1 or 2, and the curing agent comprises all the epoxy resin components and the curing agent as solid components. An epoxy resin composition containing 0.1 to 60% by weight based on the total.   Hardened | cured material formed by hardening | curing the epoxy resin composition of Claim 3.