Methods for manufacturing epoxy resins, polyhydroxy resins, epoxy resin compositions, epoxy resin cured products, and polyhydroxy resins.

Abstract

This invention provides an epoxy resin, a polyhydroxy resin, and epoxy resin compositions using the above, which are useful for insulating materials used in electrical / electronic components, exhibit excellent workability as a solid at room temperature, low viscosity during molding, and excellent solvent solubility, as well as a cured product obtained therefrom with excellent thermal conductivity and high heat resistance. An epoxy resin is represented by the following general formula (1). (Where A represents an aromatic group containing a benzene ring, biphenyl, or naphthalene ring, G represents a glycidyl group, R independently represents a hydrocarbon group having 1 to 10 carbon atoms, and n represents a number from 3 to 10.)

Description

Technical Field

[0001] This invention relates to an epoxy resin, a polyhydroxy resin, an epoxy resin composition, a cured epoxy resin, and a method for manufacturing a polyhydroxy resin. More specifically, it relates to an epoxy resin, a polyhydroxy resin, and an epoxy resin composition that are useful as insulating materials for electrical / electronic components such as semiconductor seals, multilayer boards, and heat dissipation substrates, exhibiting excellent workability as a solid at room temperature, low viscosity during molding, and excellent solvent solubility. Furthermore, it relates to a cured epoxy resin with excellent high thermal conductivity, heat resistance, and low thermal expansion, obtained by using these and curing them. Finally, it relates to a method for manufacturing the aforementioned polyhydroxy resin. Prior Technology

[0002] Epoxy resins have long been widely used in industry, but in recent years, the performance requirements have become increasingly stringent. In the electrical / electronic field and power electronics, where electronic circuits are becoming increasingly dense and high-frequency, the heat dissipation of epoxy resin compositions used for insulation has become a problem due to the increased heat generated from electronic circuits. Previously, this heat dissipation was addressed by utilizing the thermal conductivity of fillers, but with further increasing integration, there is a need to improve the thermal conductivity of the epoxy resin itself as the matrix.

[0003] As epoxy resin compositions with excellent thermal conductivity, epoxy resins having liquid crystal atom structures are known. For example, Patent Document 1 discloses an epoxy resin composition with biphenol-type epoxy resin and polyphenol resin curing agent as essential components, and reveals excellent stability and strength at high temperatures, making it suitable for use in a wide range of fields such as bonding, casting, sealing, molding, and lamination. Furthermore, Patent Document 2 discloses an epoxy compound having two liquid crystal atom structures linked by bent chains within the molecule. Moreover, Patent Document 3 discloses a resin composition containing an epoxy compound having liquid crystal atom groups.

[0004] However, epoxy resins with this liquid crystal structure have high melting points. During mixing, the high-melting-point components are difficult to dissolve, resulting in residual solvents and consequently reduced curing properties or heat resistance. Furthermore, high temperatures are required for uniform mixing of this epoxy resin with the hardener. At high temperatures, the curing reaction of the epoxy resin proceeds rapidly, and the gelation time is shortened, severely limiting the mixing process and making it difficult to operate. Moreover, if a third solvent is added to compensate for this drawback, the resin's melting point decreases, making it easier to mix uniformly, but the cured product will experience a decrease in thermal conductivity.

[0005] As a high thermal conductivity resin capable of melt mixing, Patent Document 4 discloses an epoxy resin formed by epoxidizing a mixture of hydroquinone and 4,4'-dihydroxybiphenyl, and Patent Document 5 discloses an epoxy resin formed by epoxidizing a mixture of 4,4'-dihydroxydiphenylmethane and 4,4'-dihydroxybiphenyl. However, these resins lack solvent solubility, limiting their applications. Patent Document 6 discloses a composition of epoxy resin having a diphenyl ether structure, but the curing agent is limited, and common curing agents such as phenolic varnishes have insufficient thermal conductivity and heat resistance. On the other hand, calixarene compounds, which exhibit strong crystallinity, are known as cyclic compounds, but their low solvent solubility is a problem. Furthermore, Patent Document 7 discloses a resin composition formed by mixing resorcinol-aldehyde condensate with epoxy resin, but its use is limited to that of a curing agent, and the heat resistance of the cured product is below 210°C. Patent Document 8 discloses a resin containing a cyclic compound of naphthalene, but the content of the cyclic compound is low, and the heat stabilization effect is not sufficient. [Existing Technical Documents] [Patent Literature]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 7-90052 [Patent Document 2] Japanese Patent Application Publication No. 9-118673 [Patent Document 3] Japanese Patent Application Publication No. 11-323162 [Patent Document 4] No. WO2009 / 110424 [Patent Document 5] Japanese Patent Application Publication No. 2010-43245 [Patent Document 6] Japanese Patent Application Publication No. 2012-17405 [Patent Document 7] Japanese Patent Application Publication No. 2001-106868 [Patent Document 8] Japanese Patent Application Publication No. 2012-201798 Summary of the Invention

[0007] [The problem that the invention aims to solve]

[0008] Therefore, the object of the present invention is to solve the aforementioned problems and to provide an epoxy resin, a polyhydroxy resin, and epoxy resin that are useful for insulating materials used in electrical / electronic components such as semiconductor seals, multilayer boards, and heat dissipation substrates with excellent reliability, which are solid at room temperature, have excellent workability, and exhibit low viscosity and excellent solvent solubility during molding, as well as epoxy resin compositions using the above. The invention also provides a cured product with excellent high thermal conductivity and high heat resistance obtained therefrom, and a method for manufacturing the polyhydroxy resin as a raw material therefrom. [Methods for solving problems]

[0009] Through diligent research, the inventors discovered that epoxy resin compositions using specific epoxy resins and / or polyhydroxy resins solve the aforementioned problems, and that the cured products exhibit excellent thermal conductivity and heat resistance, thus completing this invention.

[0010] That is, the present invention relates to an epoxy resin represented by the following general formula (1). [Chemistry 1] (Where, A represents an aromatic group containing a benzene ring, biphenyl, or naphthalene ring, G represents a glycidyl group, R represents a hydrocarbon group with 1 to 10 carbon atoms, and n represents a number from 3 to 10.)

[0011] The epoxy resin of the present invention is preferably the epoxy resin represented by the following general formula (2). [Chemistry 2] (Where, G represents glycidyl group, R independently represents hydrocarbon groups with 1 to 10 carbon atoms, and n represents a number from 3 to 10.)

[0012] In addition, the present invention relates to a polyhydroxy resin represented by the following general formula (3). [Chemistry 3] (Where R independently represents hydrocarbon groups with 1 to 10 carbon atoms, and n represents a number from 3 to 10.)

[0013] Furthermore, the present invention is an epoxy resin composition, characterized in that the epoxy resin is used as an essential component and / or as a curing agent, the polyhydroxy resin is used as an essential component, and it is an epoxy resin cured product obtained by curing the epoxy resin composition.

[0014] In addition, the present invention relates to a method for manufacturing a polyhydroxy resin represented by the general formula (3), and to a method for manufacturing a polyhydroxy resin by reacting hydroquinone represented by the following formula (4) with aldehydes represented by the following formula (5) and / or formula (6) in the presence of a strong acid. [Chemistry 4] [Chemistry 5] (Where, R represents a hydrocarbon group with 1 to 10 carbon atoms) [Chemistry 6] (Where, R represents a hydrocarbon group with 1 to 10 carbon atoms) [The effects of the invention]

[0015] The epoxy resin and the polyhydroxy resin used as a curing agent of the present invention exhibit good melt mixing properties and excellent solvent solubility at temperatures below 100°C, making them suitable for epoxy resin compositions and their cured products used in applications such as lamination, molding, casting, and bonding. Furthermore, the cured products also possess excellent heat resistance, thermal decomposition stability, and thermal conductivity, making them suitable for applications such as sealing of electrical / electronic components and circuit board materials. Simple Explanation of the Diagram

[0016] Figure 1 shows the FD-MS spectrum of the phenolic compound (polyhydroxy resin) obtained in Example 1. Figure 2 is a GPC diagram of the phenolic compound (polyhydroxy resin) obtained in Example 1. Figure 3 shows the FD-MS spectrum of the epoxy resin obtained in Example 2. Figure 4 is a GPC diagram of the epoxy resin obtained in Example 2. Implementation

[0017] The present invention will now be described in detail.

[0018] The epoxy resin of the present invention is represented by the general formula (1), where A represents an aromatic group comprising a benzene ring, biphenyl, or naphthalene ring. Multiple A groups may be mixed. G represents a glycidyl group. R independently represents a hydrocarbon group having 1 to 10 carbon atoms, and n represents a number from 3 to 10. Furthermore, as indicated by "independently," the epoxy resin of formula (1) of the present invention can be a mixture of different structures of A. n is the number of repetitions (number average), representing a number from 3 to 10. Preferably, it is a mixture of components with different n values.

[0019] The epoxy resin of the present invention may also be a mixture of a linear epoxy resin represented by the following general formula (7). Preferably, the linear component is 60% or less, more preferably 40% or less. When the linear component is more abundant, the heat resistance tends to decrease. [Chemistry 7] (Where, A represents an aromatic group containing a benzene ring, biphenyl, or naphthalene ring, G represents a glycidyl group, R represents a hydrocarbon group with 1 to 10 carbon atoms, and m represents a number from 0 to 15.)

[0020] In the general formula (1) or general formula (7), R independently represents a hydrocarbon group having 1 to 10 carbon atoms. R can be a mixture of hydrocarbons with different carbon atoms. R is sometimes only chain-like and contains aromatics. When it is only chain-like, the larger the carbon number, the better the solvent solubility, but the heat resistance tends to decrease. In particular, for heat resistance, it is preferable that R has a hydrocarbon group with 7 or fewer carbon atoms. More preferably, it has 1 to 4 carbon atoms. When R contains aromatics, the heat resistance is excellent, but the solvent solubility tends to decrease.

[0021] The epoxy resin of the present invention preferably has the structure represented by the general formula (2). The glycidyl group is preferably substituted at the para position. In the case of the meta-resorcinol type, the glycidyl groups of the cyclic compound are close together, which may make it difficult to control the reaction in terms of stereostructure. On the other hand, in the case of the para-hydroquinone type, a stable structure that can control the reaction can be obtained, and a cured product with high heat resistance can be obtained. In addition, in terms of heat resistance, the structure of A in the general formula is preferably biphenyl or naphthalene ring, and in terms of solvent solubility, it is preferably benzene ring.

[0022] The softening point of the epoxy resin of the present invention, or a mixture thereof with an epoxy resin represented by the general formula (7) as required, is preferably below 130°C. If the softening point is above 130°C, the melt compatibility decreases, and in the case of crystallinity, the solvent solubility also decreases further.

[0023] The method for preparing the epoxy resin of the present invention is not particularly limited, and it can be prepared by reacting a cyclic phenolic compound (polyhydroxy resin) of the following formula (8) with epichlorohydrin. The reaction can be carried out in the same manner as a conventional epoxidation reaction. [Chemistry 8] (Where, A represents an aromatic group containing a benzene ring, biphenyl, or naphthalene ring, R independently represents a hydrocarbon group with 1 to 10 carbon atoms, and n represents a number from 3 to 10.)

[0024] As the phenolic compound of formula (8), as described above, it is preferably hydroquinone with the hydroxyl group at the para position, and in order to obtain the epoxy resin represented by the general formula (2), it is more preferably A to be a benzene ring as in formula (3).

[0025] The reaction of the phenolic compound of formula (8) with epichlorohydrin can be illustrated by the following method: after dissolving the phenolic compound in excess epichlorohydrin, the reaction is carried out in the presence of alkali metal hydroxides such as sodium hydroxide and potassium hydroxide at a temperature of 50°C to 150°C, preferably 60°C to 100°C, for 1 to 10 hours. The amount of alkali metal hydroxide used is 0.8 to 2.0 mol, preferably 0.9 to 1.5 mol, relative to 1 mol of the hydroxyl group in the phenolic compound. Epichlorohydrin is used in excess relative to the hydroxyl group in the phenolic compound; typically, it is 1.5 to 15 mol relative to 1 mol of the hydroxyl group in the phenolic compound. After the reaction is complete, the excess epichlorohydrin is removed by distillation, the residue is dissolved in solvents such as toluene and methyl isobutyl ketone, filtered, and washed with water to remove inorganic salts. The solvent is then removed by distillation, thereby obtaining the target epoxy resin.

[0026] The epoxy resin of the present invention is obtained as a mixture with the epoxy resin represented by the general formula (7) when the raw material contains a phenolic compound comprising a linear polyhydroxy resin represented by general formula (9). [Chemistry 9] (Where, A, R, and m have the same meaning as in equation (7))

[0027] Regarding the purity of the epoxy resin of the present invention, particularly the amount of hydrolyzable chlorine, from the viewpoint of improving the reliability of electronic components used in the application, a lower amount is preferable. While not particularly limited, it is preferably below 1000 ppm, and more preferably below 500 ppm. Furthermore, the hydrolyzable chlorine content described in the present invention refers to a value obtained by the following method: 0.5 g of the sample is dissolved in 30 ml of dioxane, 10 ml of 1N-KOH is added, and the mixture is boiled and refluxed for 30 minutes. After cooling to room temperature, 100 ml of 80% acetone water is added, and the value is obtained by potentiometric titration with a 0.002N-AgNO3 aqueous solution.

[0028] Here, there is no limitation on the phenolic compound represented by formula (8). For example, it can be obtained by condensing aldehydes such as acetaldehyde, propionaldehyde, n-butyraldehyde, paraldehyde, benzaldehyde, 4-methylbenzaldehyde, 3-methylbenzaldehyde, 2-methylbenzaldehyde, 4-ethylbenzaldehyde, 2,4-dimethylbenzaldehyde, 3,4-dimethylbenzaldehyde, 4-isopropylbenzaldehyde, and 4-tert-butylbenzaldehyde in the presence of organic or inorganic acids with hydroquinone, catechol, resorcinol, etc. Difunctional phenolic compounds such as 4,4'-biphenol, 2,2'-biphenol, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,4-dihydroxynaphthalene, 2,5-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, and 2,8-dihydroxynaphthalene (for example, refer to the methods described in "Aldrichimica Acta", Vol. 28, No. 1, 1995, pp. 3-9).

[0029] As an aldehyde, a variety of mixtures can be used, but in terms of heat resistance and solvent solubility, it is preferred to use acetaldehyde with R being methyl or to use trimerized acetaldehyde, with a molar ratio of acetaldehyde to more than 50% of the total aldehydes.

[0030] The mole ratio for the reaction of phenolic compounds with aldehydes is not particularly limited, but the ratio of aldehydes to phenolic compounds is preferably 0.3 to 1.2 mol, more preferably 0.5 to 1.0 mol, relative to 1 mol of phenolic compound. Furthermore, when the aldehyde is a polymeric aldehyde, it is preferable that the mole amount of the polymer multiplied by the degree of polymerization of the polymer satisfies the aforementioned mole range. For example, 1 mol of metaldehyde is equivalent to 3 mol of acetaldehyde; therefore, when using metaldehyde, a ratio of 0.1 to 0.4 mol relative to 1 mol of phenolic compound is preferred.

[0031] As a catalyst, there are no particular restrictions as long as the reaction proceeds; any known type of catalyst can be used, such as inorganic acids or organic acids. Specific examples include hydrobromic acid, hydrochloric acid, sulfuric acid, phosphoric acid, oxalic acid, trifluoroacetic acid, p-toluenesulfonic acid, methanesulfonic acid, and boron trifluoride. Hydrochloric acid and sulfuric acid, which are strong acids, are particularly preferred.

[0032] The amount of catalyst relative to the phenolic compound is preferably 0.1% to 30.0% by mass, more preferably 1.0% to 10.0% by mass. If the amount of catalyst is less than the lower limit of the range, the reaction rate tends to slow down; if it is higher than the upper limit, the reaction control tends to become difficult.

[0033] There are no particular restrictions on the reaction solvent, but water or a hydrocarbon-based solvent is preferred. Examples of hydrocarbon-based solvents include n-hexane, cyclohexane, and toluene. A single reaction solvent or a mixture of two or more solvents can be used.

[0034] The preferred reaction temperature for the phenolic compounds with aldehydes is 20°C to 150°C, more preferably 60°C to 110°C. If the reaction temperature is below the lower limit of the range, the reaction tends to slow down; if it is above the upper limit, the reaction tends to become difficult to control.

[0035] The reaction products precipitated from the reaction of the phenolic compounds with aldehydes can be recovered using known solid-liquid separation processes such as filtration. After recovery, further treatment such as washing, purification, and recrystallization may be performed as needed.

[0036] In order to manufacture the polyhydroxy resin represented by formula (3), the aldehydes represented by formula (5) and / or formula (6) are preferably reacted with hydroquinone represented by formula (4) in the phenolic compound represented by formula (8). More preferably, acetaldehyde and / or triacetaldehyde in formula (5) and / or (6) where R is methyl are used, under the conditions described above.

[0037] In the epoxy resin of the present invention, in addition to the epoxy resin of formula (1) or any epoxy resin of formula (7) used as an essential component, other epoxy resins having two or more epoxy groups in the molecule may also be used as epoxy resin components. For example, there are bisphenol A, bisphenol F, 3,3',5,5'-tetramethyl-4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl ketone, fluorenebisphenol, 4,4'-biphenol, 3,3',5,5'-tetramethyl-4,4'-dihydroxybiphenyl, 2,2'-biphenol, resorcinol, phthalic acid, etc. Phenol, tert-butylcatechol, tert-butylhydroquinone, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,4-dihydroxynaphthalene, 2,5-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2,8-dihydroxynaphthalene, and the aforementioned Allylated or polyallylated dihydroxynaphthalenes, allylated bisphenol A, allylated bisphenol F, allylated phenolic varnishes, and other diphenolic compounds, or phenolic varnishes, bisphenol A varnishes, o-cresol varnishes, m-cresol varnishes, p-cresol varnishes, xylenol varnishes, poly-p-hydroxystyrene, tris-(4-hydroxyphenyl)methane, 1,1,2,2-tetra(4-hydroxyphenyl) Ethane, fluoroglycinol, pyrogallol, tert-butylpyrogallol, allylated pyrogallol, polyallylated pyrogallol, 1,2,4-benzenetriol, 2,3,4-trihydroxybenzophenone, phenolic aralkyl resins, naphthol aralkyl resins, dicyclopentadiene resins, and other ternary or higher phenols, or glycidyl ethers derived from halogenated bisphenols such as tetrabromobisphenol A, etc. One or more of these epoxy resins may be used, or a mixture of two or more may be used.

[0038] The epoxy resin composition of the present invention comprises an epoxy resin and a curing agent, and may also contain any other components described below. In this case, the epoxy resin composition of the present invention preferably uses the epoxy resin represented by the general formula (1) and / or uses the polyhydroxy resin represented by the general formula (8) as the curing agent, and more preferably uses the general formula (3).

[0039] When using an epoxy resin composition containing an epoxy resin represented by general formula (1), the mixing ratio of the epoxy resin in formula (1) is preferably 30 wt% or more of the total epoxy resin, and more preferably 50 wt% or more. If it is less than this, the effect of improving the heat resistance and other physical properties when the cured product is made may be reduced.

[0040] In the case of epoxy resin compositions using epoxy resins represented by general formula (1), all known epoxy resin curing agents can be used, including dicyandiamine, acid anhydrides, polyphenols, aromatic and aliphatic amines, etc. Among these, polyphenols are preferred as curing agents in fields requiring high electrical insulation, such as semiconductor sealing materials. Furthermore, binary phenols are preferred as curing agents with excellent thermal conductivity. Specific examples of curing agents are shown below.

[0041] Examples of polyphenols include binary phenols such as bisphenol A, bisphenol F, bisphenol S, fluorenebisphenol, 4,4'-biphenol, 2,2'-biphenol, hydroquinone, resorcinol, and naphthalene glycol, as well as ternary or higher phenols represented by tri-(4-hydroxyphenyl)methane, 1,1,2,2-tetra(4-hydroxyphenyl)ethane, phenolic varnish, o-cresol phenolic varnish, naphthol phenolic varnish, and polyvinylphenol. Furthermore, there are polyphenolic compounds synthesized by combining binary phenols such as phenols, naphthols, bisphenol A, bisphenol F, bisphenol S, fluorenebisphenol, 4,4'-biphenol, 2,2'-biphenol, hydroquinone, resorcinol, and naphthalene glycol with condensing agents such as formaldehyde, acetaldehyde, benzaldehyde, p-hydroxybenzaldehyde, and terephthalic acid diethanolamide.

[0042] Examples of acid anhydride curing agents include phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylheptahydrophthalic anhydride, dodecynyl succinic anhydride, nadic anhydride, and trimellitic anhydride.

[0043] As amine-based curing agents, there are aromatic amines such as 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenylmethane, m-phenylenediamine, and p-phenylenediamine, as well as aliphatic amines such as ethylenediamine, hexamethylenediamine, diethylenetriamine, and triethylenetetramine.

[0044] The epoxy resin composition may use one or more of these hardeners in combination.

[0045] Regarding the mixing ratio of epoxy resin and hardener, it is preferable to make the ratio of epoxy groups to functional groups in the hardener in an equivalent ratio of 0.8 to 1.5. If it is outside the range, unreacted epoxy groups or functional groups in the hardener will remain after curing, which will reduce the reliability of the sealing function and is therefore undesirable.

[0046] As an epoxy resin composition of the present invention, if a polyhydroxy resin represented by the general formula (8) (preferably general formula (3)) is used as a curing agent, the epoxy resin is not limited to the formula (1). As this epoxy resin, all of the epoxy resins can be used without restriction. In terms of heat resistance and thermal conductivity, epoxy resins having a divalent rigid structure are preferred, such as 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl ketone, 4,4'-dihydroxydiphenyl ether, 4,4'-biphenol, 2,2'-biphenol, hydroquinone, resorcinol, catechol, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, Glycidyl ether compounds derived from 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,4-dihydroxynaphthalene, 2,5-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, and 2,8-dihydroxynaphthalene, are preferred, and more preferably, glycidyl ether compounds derived from 4,4'-dihydroxydiphenyl ketone, 4,4'-dihydroxydiphenyl ether, 4,4'-biphenol, and hydroquinone are preferred. In this case, the proportion of the polyhydroxy resin represented by the general formula (8) (preferably general formula (3)) as the curing agent is preferably 20 wt% or more, more preferably 50 wt% or more of the total curing agent. If it is less than this, the effect of improving the heat resistance and other physical properties when the cured product is produced may be reduced.

[0047] The epoxy resin composition of this invention may also be appropriately formulated with oligomers or polymers such as polyester, polyamide, polyimide, polyether, polyurethane, petroleum resin, indene resin, indene / coumarone resin, and phenoxy resin as other modifiers. Regarding the amount added, it is generally in the range of 1 to 30 parts by weight relative to 100 parts by weight of the total resin components.

[0048] The epoxy resin composition of the present invention may be formulated with inorganic fillers, pigments, flame retardants, weathering agents, coupling agents, flow improvers, and other additives. Examples of inorganic fillers include spherical or fragmented molten silica powder, crystalline silica powder, alumina powder, glass powder, or mica, talc, calcium carbonate, alumina, hydrated alumina, etc., and the preferred formulation amount for use in semiconductor sealing materials is 70% by weight or more, and more preferably 80% by weight or more.

[0049] As pigments, there are organic or inorganic extender pigments, flake pigments, etc. As viscotropic agents, examples include: silicone-based, castor oil-based, aliphatic amide waxes, oxidized polyethylene waxes, organobentonite-based, etc.

[0050] Curing accelerators may be used in the epoxy resin composition of the present invention as needed. Examples include amines, imidazoles, organophosphorus compounds, Lewis acids, etc., specifically including: tertiary amines such as 1,8-diazabicyclo(5,4,0)undecene-7, triethyldiamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris(dimethylaminomethyl)phenol, 2-methylimidazolium, 2-phenylimidazolium, 2-ethyl-4-methylimidazolium, 2-phenyl-4-methylimidazolium, 2-heptadecylimidazolium, tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine, phenylphosphine, tetraphenylphosphonium / tetraphenylborate, tetraphenylphosphonium / ethyltriphenylborate, tetrabutylphosphonium / tetrabutylborate, 2-ethyl-4-methylimidazolium / tetraphenylborate, N-methylmorpholine / tetraphenylborate, etc. As an addition amount, it is typically in the range of 0.01 parts by weight to 5 parts by weight relative to 100 parts by weight of the total resin components.

[0051] Furthermore, as needed, release agents such as carnauba wax and OP wax, coupling agents such as γ-glycidoxypropyltrimethoxysilane, colorants such as carbon black, flame retardants such as antimony trioxide, low-stress agents such as silicone oil, and lubricants such as calcium stearate can be used in the epoxy resin composition of the present invention.

[0052] The epoxy resin composition of the present invention can be prepared by impregnating a fibrous material such as glass cloth, polyaramid nonwoven fabric, or polyester nonwoven fabric containing dissolved organic solvents, after the solvent is removed, to produce a prepreg. Alternatively, depending on the circumstances, it can be coated onto sheet materials such as copper foil, stainless steel foil, polyimide film, or polyester film to form a laminate.

[0053] By heating and curing the epoxy resin composition of the present invention, the resin-cured product of the present invention can be produced. The cured product can be obtained by molding the epoxy resin composition using methods such as casting, compression molding, or transfer molding. The temperature at this time is typically in the range of 120°C to 220°C. Regarding heat resistance, a Tg of over 250°C is observed, and a Tg of over 300°C is also possible. Compared to the typical Tg limit of around 250°C for epoxy resin cured products, the cured product of the present invention exhibits exceptional heat resistance. Furthermore, cured products with high heat resistance typically have a high residual carbon content and are prone to forming a carbonized layer, making it difficult to simultaneously achieve leakage resistance. However, the cured product of the present invention has a low residual carbon content, making it difficult to form a carbonized layer, implying excellent voltage resistance or leakage resistance. Therefore, applications in the field of electronic materials, particularly in power devices requiring heat resistance, automotive applications, and electronic materials used under high voltage conditions, are expected. [Example]

[0054] The present invention will now be specifically described by way of examples and comparative examples. However, the present invention is not limited to these examples. Unless otherwise specified, "parts" refers to parts by weight, and "%" refers to percentage by weight. Furthermore, the determination methods are as follows.

[0055] 1) Epoxy equivalent A potentiometric titration apparatus was used, with methyl ethyl ketone as the solvent, and tetraethylammonium bromide acetic acid solution was added. The determination was performed using a 0.1 mol / L perchloric acid-acetic acid solution via the potentiometric titration apparatus.

[0056] 2) OH equivalent Using a potentiometric titration apparatus, 1,4-dioxane was used as the solvent, acetylated with 1.5 mol / L acetylated chloride, excess acetylated chloride was decomposed with water, and titrated with 0.5 mol / L potassium hydroxide.

[0057] 3) Melting point The differential scanning calorimetry (DSC) peak temperature was determined using a differential scanning calorimetry (DSC) device (manufactured by SII Nano Technology Co., Ltd., EXSTAR 6000 DSC / 6200) at a heating rate of 5°C / min. That is, the DSC peak temperature was taken as the melting point of the resin.

[0058] 4) Melt viscosity The measurements were performed at 150°C using a Brookfield CAP2000H rotational viscometer.

[0059] 5) Softening point The test was conducted using the ring and ball method in accordance with Japanese Industrial Standards (JIS) K-2207.

[0060] 6) GPC measurement The apparatus (manufactured by Tosoh Corporation, HLC-8220GPC) used a device comprising four TSKgel SuperMultipore HZ-N columns in series, with the column temperature set to 40°C. Tetrahydrofuran (THF) was used as the eluent at a flow rate of 0.35 mL / min, and a differential refractive index detector was used. The sample was measured using 50 μL of a solution containing 0.1 g of the sample dissolved in 10 mL of THF and filtered through a microfilter. Data processing was performed using the GPC-8020 Model II version 6.00 manufactured by Tosoh Corporation.

[0061] 7) Glass transition point (Tg) Dynamic viscoelasticity was measured using a thermomechanical measurement apparatus (manufactured by SII Nano Technology Co., Ltd., EXSTAR DMS6100) under nitrogen flow conditions, with a heating rate of 3°C / min and 10 Hz. The peak value of tanδ was taken as the glass transition temperature.

[0062] 8) 5% weight reduction temperature (Td5), residual carbon content The 5% weight loss temperature (Td5) was determined using a thermogravimetric / differential thermal analysis apparatus (manufactured by SII Nano Technology, EXSTAR DMA7300) under nitrogen conditions, with a heating rate of 10°C / min. Additionally, the weight loss at 700°C was measured and calculated as the residual carbon percentage.

[0063] 9) Thermal conductivity Thermal conductivity was measured using a NETZSCH LFA447 thermal conductivity meter via the transient hot wire method.

[0064] 10) Melt-mixability Confirm the melt-mixability at 100℃. Let ○ represent: mixable, △: difficult to mix, ×: contains unmelted components.

[0065] 11) Solvent solubility Weigh 2 g of resin composition and 2 g of methyl ethyl ketone into a sample bottle, heat them to dissolve, and then gradually lower the temperature in a constant temperature bath to measure the temperature of the resin precipitation in the bath. Set the precipitation temperature below 25℃ as ○, set the precipitation temperature above 26℃ and below 60℃ as △, and set the precipitation temperature above 60℃ as ×.

[0066] 12) Field Desorption-Mass Spectrometry (FD-MS) The determination was performed using a JMS-T100GCV mass spectrometer (manufactured by Nippon Electron Ltd.). The sample was dissolved in acetone for analysis.

[0067] Example 1 110.0 g of hydroquinone, 16.0 g of 36% hydrochloric acid, and 220.0 g of water were added to a 2 L four-necked separable flask containing a thermometer, stirrer, cooling tube, and Dean-Stark tube. Under a nitrogen stream, the mixture was stirred and heated to 90 °C. 32.4 g of n-butyraldehyde and 19.8 g of metaldehyde were added dropwise, and the mixture was refluxed for dehydration while reacting for 6 hours. After cooling to room temperature, the mixture was repeatedly filtered, neutralized, and washed with water, and then dried under reduced pressure to obtain 102 g of a pale yellow solid phenolic compound (hardener a). Hardener a had an OH equivalent of 70 g / eq. and a number average molecular weight of 1200. The FD-MS spectrum of the obtained phenolic compound is shown in Figure 1, and the GPC diagram is shown in Figure 2. In Figure 1, the cyclic compounds of the general formula (3) with n=4 were identified (R=CH3 only, which is 544; R=CH3 / CH2CH2CH3=1 / 3, which is 573; R=CH3 / CH2CH2CH3=2 / 2, which is 600) and the cyclic compounds with n=5 were identified (R=CH3 only, which is 680; R=CH3 / CH2CH2CH3=1 / 4, which is 708; R=CH3 / CH2CH2CH3=2 / 3, which is 736).

[0068] Example 2 Instead of using butyraldehyde, the amount of metaldehyde used was set to 39.6 g. Otherwise, the reaction was carried out in the same manner as in Example 1 to obtain 98 g of the phenolic compound. The obtained phenolic compound had an OH equivalent of 70 g / eq. and a number average molecular weight of 1200. Next, 25.0 g of the obtained phenolic compound, 500 g of epichlorohydrin, and 100 g of diethylene glycol dimethyl ether were charged into a 1 L four-necked separable flask. Under reduced pressure (approximately 130 Torr), 32.4 g of a 48% sodium hydroxide aqueous solution was added dropwise at 65°C for 3 hours. During this process, the generated water was removed from the system by azeotropic reaction with epichlorohydrin, and the distilled epichlorohydrin was returned to the system. After the addition was complete, the reaction was continued for another hour for dehydration. After the reaction was complete, filtration and drying under reduced pressure yielded 34.0 g of a pale yellow solid epoxy resin (epoxy resin A). The softening point of the obtained epoxy resin A was 101°C, the epoxy equivalent was 155 g / eq., and the number average molecular weight was 1600. The FD-MS spectrum of the obtained epoxy resin is shown in Figure 3, and the GPC diagram is shown in Figure 4. The main peaks m / z = 992, 1240, and 1489 in Figure 3 correspond to the cyclic compounds of general formula (2) with R = CH3 and n = 4, 5, and 6, respectively.

[0069] Example 3 The amount of butyraldehyde used was set to 13.0 g, and the amount of metaldehyde used was set to 31.7 g. Otherwise, the reaction was carried out in the same manner as in Example 1 to obtain 91 g of phenolic compound. The obtained phenolic compound had an OH equivalent of 75 g / eq. and a number average molecular weight of 1290. 25.0 g of the obtained phenolic compound was epoxidized in the same manner as in Example 2 to obtain 34.0 g of a pale yellow solid epoxy resin (epoxy resin B). The obtained epoxy resin B had a softening point of 69°C, an epoxy equivalent of 160 g / eq., and a number average molecular weight of 1660.

[0070] Comparative Example 1 In a flask fitted with a Dean-Stark tube, 300.0 g of hydroquinone, 28.9 g of formaldehyde, and 263.1 g of diethylene glycol dimethyl ether were added. The mixture was heated to approximately 100°C under a nitrogen atmosphere with stirring to dissolve the compounds. Next, 0.33 g of p-toluenesulfonic acid was added, and the mixture was heated to 160°C. The reaction was carried out for 6 hours while simultaneously dehydrating the mixture, producing a phenolic compound. The diethylene glycol dimethyl ether was removed by distillation. After adding methyl isobutyl ketone, the mixture was neutralized, washed with water, and filtered. The methyl isobutyl ketone was then removed by vacuum distillation to obtain 295 g of the phenolic compound (hardener b). Hardener b had an OH equivalent of 75 g / eq, a number average molecular weight of 1500, and a softening point of 80°C.

[0071] Comparative Example 2 Instead of using n-butyraldehyde, the amount of triacetaldehyde used was set to 39.6 g, and resorcinol 110.0 g was used to replace hydroquinone. Otherwise, the reaction was carried out in the same manner as in Example 1 to obtain 105 g of a white solid phenolic compound (curing agent c). The OH equivalent of curing agent c was 73 g / eq., and the melting point was above 300°C. Furthermore, if the obtained phenolic compound is subjected to epoxidation in the same manner as in Example 2, it exhibits self-polymerization properties, making reaction control difficult and impossible to synthesize.

[0072] Examples 4 to 6 and Comparative Examples 3 to 7 Using epoxy resin A obtained in Example 2, epoxy resin B obtained in Example 3, epoxy resin C (o-cresol phenolic varnish type epoxy resin, YDCN-700-3, epoxy equivalent 200 g / eq., softening point 65°C, manufactured by JITCO Chemical & Materials), and epoxy resin D (4,4'-dihydroxydiphenyl ether type epoxy resin, epoxy equivalent 163 g / eq.; YSLV-80DE, manufactured by JITCO Chemical & Materials) as epoxy resin components, and using curing agent a obtained in Example 1, curing agent b obtained in Comparative Example 1, curing agent c obtained in Comparative Example 2, and curing agent d (4,4'-dihydroxydiphenyl ether, OH equivalent 101 g / eq., manufactured by Tokyo Chemical Industry) as curing agents, and triphenylphosphine as a curing accelerator, epoxy resin compositions were obtained according to the formulation shown in Table 1. The values ​​in the table represent parts by weight in the formulation. The epoxy resin composition was molded at 175°C and cured after 5 hours at 175°C to obtain a hardened test piece, which was then used for various property tests. In Comparative Example 7 only, the resin composition was heated and dissolved in 30 g of cyclohexanone, and then cured under vacuum at reduced pressure, at 130°C for 15 minutes and at 250°C for 80 minutes at 2 MPa, and the resulting product was used for property evaluation.

[0073] [Table 1] Example 4 Example 5 Example 6 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Epoxy Resin A 18.2 Epoxy Resin B 18.4 Epoxy Resin C 19.9 21.8 22.0 Epoxy Resin D 21.0 20.6 20.7 hardener a 9.0 hardener b 9.4 8.2 hardener c 9.3 8.0 hardener d 11.8 11.6 10.1 hardening accelerator 0.24 0.24 0.24 0.24 0.24 0.24 0.24 0.24 Melt-mixing properties ○ ○ ○ ○ ○ ○ × × Solvent solubility ○ ○ ○ ○ ○ ○ × × Tg (°C) >300 >300 260 142 138 183 Unable to form 201 Td5(℃) 382 383 381 384 385 378 365 Residual carbon content (wt%) 27 26 twenty two twenty two 31 35 20 thermal conductivity (W / m·K) 0.27 0.26 0.25 0.21 0.23 0.20 0.20

[0074] These results confirm that the epoxy resin obtained in the examples has excellent melt mixing and solvent solubility, and its cured product has good thermal stability and thermal conductivity, thus making it suitable for power devices and automotive applications.

[0075] none

Claims

1. An epoxy resin, represented by the following general formula (2); wherein, G represents glycidyl group, R represents hydrocarbon groups with 1 to 10 carbon atoms, and n represents a number from 3 to 10.

2. A polyhydroxy resin, represented by the following general formula (3); wherein, R represents hydrocarbon groups with 1 to 10 carbon atoms, and n represents a number from 3 to 10.

3. An epoxy resin composition comprising an epoxy resin and a curing agent, characterized in that the epoxy resin as described in claim 1 is an essential component.

4. An epoxy resin composition comprising an epoxy resin and a curing agent, wherein the epoxy resin composition is characterized in that, as part or all of the curing agent, it comprises a polyhydroxy resin as described in claim 2 as an essential component.

5. An epoxy resin cured material obtained by curing an epoxy resin composition as described in claim 3 or claim 4.

6. A method for manufacturing a polyhydroxy resin, comprising a method for manufacturing a polyhydroxy resin represented by the following general formula (3), wherein, R represents a hydrocarbon group having 1 to 10 carbon atoms, and n represents a number from 3 to 10. The product is characterized by reacting hydroquinone represented by formula (4) with an aldehyde represented by formula (5) and / or formula (6) in the presence of a strong acid; wherein R represents a hydrocarbon group having 1 to 10 carbon atoms.

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