CN116234851A

CN116234851A - Epoxy resin, curable resin composition, and cured product thereof

Info

Publication number: CN116234851A
Application number: CN202180063925.9A
Authority: CN
Inventors: 远岛隆行; 洼木健一; 鎗田正人; 中西政隆; 川野裕介
Original assignee: Nippon Kayaku Co Ltd
Current assignee: Nippon Kayaku Co Ltd
Priority date: 2020-11-19
Filing date: 2021-11-11
Publication date: 2023-06-06
Also published as: JP7256160B2; TW202221054A; WO2022107678A1; JP2022080916A; KR20230107539A

Abstract

The invention provides an epoxy resin and an epoxy resin composition, wherein a hardened product of the epoxy resin composition has high heat resistance, high elastic modulus and low water absorption. An epoxy resin represented by the following formula (1), wherein the total content of the epoxy resins represented by the following formulas (2) to (4) is 80 area% or less in the epoxy resin represented by the following formula (1). (in the formula (1), n is a repetition number, and the average value thereof is 1 < n < 5.)

Description

Epoxy resin, curable resin composition, and cured product thereof

Technical Field

The present invention relates to an epoxy resin having a specific structure, a curable resin composition, and a cured product thereof.

Background

Epoxy resins are cured with various curing agents to form cured products excellent in mechanical properties, water resistance, chemical resistance, heat resistance, electrical properties, and the like, and are used in a wide variety of fields such as adhesives, paints, laminates, molding materials, casting materials, and the like. Carbon fiber reinforced composite materials (carbon fiber reinforced plastics (carbon fiber reinforced plastic, CFRP)) obtained by impregnating reinforcing fibers with an epoxy resin and a curing agent as matrix resins (matrix resin) can impart characteristics such as weight reduction and high strength, and therefore, they have been widely used in recent years for computer applications such as structural members for aircraft, blades for windmills, automobile outer panels and integrated circuit (integrated circuit, IC) trays, housings (cases) for notebook personal computers, and the like, and particularly for matrix resins for aircraft by utilizing the characteristics of lightweight and high strength of molded articles thereof.

In general, as a resin used for a matrix resin such as CFRP, a bisphenol a type epoxy resin, a bisphenol F type epoxy resin, a tetraglycidyl diamino diphenyl methane, and the like are used, and in aviation applications, a glycidylamine type epoxy resin, a tetraglycidyl diamino diphenyl methane, and the like are used.

In recent years, CFRP has been required to have strict characteristics, and when applied to structural materials for aerospace applications, vehicles, and the like, heat resistance of 180 ℃ or higher is required (patent document 1). The glycidylamine-based material has high heat resistance, but has a problem of high water absorption and deterioration of the properties after water absorption. On the other hand, a typical glycidyl ether type epoxy resin has a relatively low water absorption rate, but has a problem of low elastic modulus. Therefore, a material having high heat resistance and high elastic modulus and satisfying low water absorption is demanded.

Prior art literature

Patent literature

Patent document 1: international publication No. 2010/204173

Disclosure of Invention

Problems to be solved by the invention

In view of the above problems, an object of the present invention is to provide an epoxy resin and an epoxy resin composition, wherein the cured product has high heat resistance, high elastic modulus and low water absorption.

Technical means for solving the problems

The present inventors have made an effort to solve the above problems, and as a result, have completed the present invention. That is, the present invention relates to the following [1] to [8].

[1]

An epoxy resin represented by the following formula (1), wherein,

the total content of the epoxy resins represented by the following formulas (2) to (4) is 80 area% or less in the epoxy resin represented by the following formula (1).

[ chemical 1]

(in the formula (1), n is a repetition number, and the average value thereof is 1 < n < 5.)

[ chemical 2]

[2]

The epoxy resin according to the preceding item [1], wherein the component of n=1 in the formula (1) is 80 area% or less.

[3]

The epoxy resin according to the preceding item [1] or the preceding item [2] is represented by the following formula (5).

[ chemical 3]

(in the formula (5), n is a repetition number, and the average value thereof is 1 < n < 5.)

[4]

A curable resin composition comprising the epoxy resin according to any one of the preceding items [1] to [3 ].

[5]

The curable resin composition according to item [4], further comprising a hardener.

[6]

A cured product obtained by curing the curable resin composition according to the above [4] or the above [5 ].

ADVANTAGEOUS EFFECTS OF INVENTION

The present invention relates to an epoxy resin having a specific structure, a curable resin composition, and a cured product thereof, which has high heat resistance, high elastic modulus, and low water absorption.

Therefore, the present invention can be effectively used for insulating materials (high-reliability semiconductor sealing materials and the like) for electric and electronic parts, laminated boards (printed wiring boards, build-up boards and the like), various composite materials typified by CFRP, adhesives, paints and the like.

Drawings

FIG. 1 shows a gel permeation chromatograph (gel permeation chromatography, GPC) diagram of Synthesis example 1.

FIG. 2 shows a hydrogen nuclear magnetic resonance (1H-nuclear magnetic resonance, 1H-NMR) chart of Synthesis example 1.

FIG. 3 shows a high performance liquid chromatography (high performance liquid chromatography, HPLC) chart of Synthesis example 1.

FIG. 4 shows a GPC chart of example 1.

FIG. 5 shows a 1H-NMR chart of example 1.

FIG. 6 shows an HPLC chart of example 1.

Fig. 7 shows a GPC diagram of reference example 1.

FIG. 8 shows a 1H-NMR chart of reference example 1.

Fig. 9 shows an HPLC diagram of reference example 1.

Detailed Description

The present invention will be described in detail below.

The epoxy resin of the present invention may use an aromatic amine resin represented by the following formula (6) as a precursor.

[ chemical 4]

(in the formula (6), n is a repetition number, and the average value thereof is 1 < n < 5.)

The aromatic amine resin represented by the formula (6) is more preferable when represented by the following formula (7). The reason for this is that: in comparison with the case where the substitution position of each isopropylidene linkage with respect to the benzene ring to which an amino group is not bonded is ortho-or para-in the formula (6), crystallinity is lowered. By decreasing the crystallinity, the solvent stability increases, and the preparation of the resin solution becomes easy. In addition, regarding the compound derived therefrom, crystallinity can also be reduced. Therefore, crystallization can be suppressed even in the storage after the composition is formed.

[ chemical 5]

(in the formula (7), n is a repetition number, and the average value thereof is 1 < n < 5.)

The method for producing the aromatic amine resin represented by the formula (6) or (7) is not particularly limited. For example, in Japanese patent application laid-open No. 61-000044, the n=1 body in the above formula (4) can be obtained by reacting aniline with m-diisopropenylbenzene or m-di (α -hydroxyisopropyl) benzene in the presence of an acidic catalyst at 180 to 250℃as the main component, but contains three isomers of 1, 3-bis (p-amino cumyl) benzene, 1- (o-amino cumyl) -3- (p-amino cumyl) benzene, 1, 3-bis (o-amino cumyl) benzene. Further, n=2 to 5 is also produced as a subcomponent, but in japanese patent laid-open No. 61-000044, these were purified by crystallization to obtain 1, 3-bis (p-amino cumyl) benzene having a purity of 98%.

In the present invention, an epoxy resin having high heat resistance, low water absorption, high elastic modulus and low viscosity has been developed by taking into account isomers and polymer components in an aromatic amine resin which have been removed as unnecessary components before and by epoxidizing these components instead of removing them.

That is, since the amine resin as the raw material of the epoxy resin of the present invention does not require a purification step such as crystallization, it can be produced in a short time at low cost, and thus the industrial applicability can be improved.

Examples of the acidic catalyst used in synthesizing the aromatic amine resin represented by the above formula (6) include: hydrochloric acid, phosphoric acid, sulfuric acid, formic acid, zinc chloride, ferric chloride, aluminum chloride, p-toluenesulfonic acid, methanesulfonic acid, activated clay, ion exchange resins and the like. These may be used singly or in combination of two or more. The amount of the catalyst to be used is 0.1 to 50% by weight, preferably 1 to 30% by weight, based on the aniline to be used, and if the amount is too large, the viscosity of the reaction solution becomes too high, stirring becomes difficult, and if the amount is too small, the progress of the reaction becomes slow.

The reaction may be carried out using an organic solvent such as toluene or xylene, if necessary, or may be carried out in the absence of a solvent. For example, when the catalyst contains water after adding an acidic catalyst to a mixed solution of aniline and a solvent, it is preferable to remove water from the system by azeotropic distillation. Then diisopropenylbenzene or di (alpha-hydroxyisopropyl) benzene is added, and then the temperature is raised while removing the solvent from the system, and the reaction is carried out at 140 to 220 ℃, preferably 160 to 200 ℃ for 5 to 50 hours, preferably 5 to 30 hours. Water is by-produced when bis (α -hydroxyisopropyl) benzene is used, and is therefore removed from the system while azeotroping with the solvent at the time of heating. After the reaction, the acid catalyst was neutralized with an aqueous alkali solution, a water-insoluble organic solvent was added to the oil layer, and the water washing was repeated until the wastewater became neutral, after which the solvent and the excess aniline derivative were removed under reduced pressure and heating. In the case of using activated clay or ion exchange resin, the reaction solution is filtered after the completion of the reaction to remove the catalyst.

Further, since diphenylamine is by-produced depending on the reaction temperature or the kind of the catalyst, the diphenylamine derivative is removed to 1% by weight or less, preferably 0.5% by weight or less, more preferably 0.2% by weight or less at a high temperature under a high vacuum or by means of steam distillation or the like.

The epoxy resin of the present invention is represented by the following formula (1), and the total content of the epoxy resins represented by the following formulas (2) to (4) is 80 area% or less in the epoxy resin represented by the following formula (1).

[ chemical 6]

[ chemical 7]

In formula (1), n is preferably 1 < n < 5, more preferably 1 < n < 3.

The total content of the epoxy resins represented by the formulas (2) to (4) in the epoxy resin represented by the formula (1) can be determined by an analysis method using both gel permeation chromatography and high performance liquid chromatography. In the present invention, the analysis was performed under the following conditions.

GPC (gel permeation chromatography) analysis

And (3) pipe column: showa (SHODEX) GPC KF-601 (two), KF-602, KF-602.5, KF-603

Flow rate: 0.5ml/min.

Column temperature: 40 DEG C

Solvent was used: tetrahydrofuran (THF)

A detector: RI (refractive index) (differential refractive detector)

HPLC (high Performance liquid chromatography) analysis

And (3) pipe column: xionsil ODS-2

Flow rate: 1.0ml/min.

Column temperature: 40 DEG C

Solvent was used: acetonitrile/10 mmol/L phosphoric acid aqueous solution

A detector: light diode array (274 nm)

Specifically, the content (α) of the n=1 component in the epoxy resin represented by the above formula (1) can be obtained by gel permeation chromatography, and the contents (β2 to β4) of the epoxy resins represented by the above formulas (2) to (4) contained in the n=1 component can be obtained by high performance liquid chromatography. Therefore, for example, the product of α and β2 becomes the content of the epoxy resin represented by the formula (2) contained in the epoxy resin represented by the formula (1).

In the epoxy resin of the present invention, the total content of the epoxy resins represented by the formulas (2) to (4) in the epoxy resin represented by the formula (1) is preferably 80% by area or less, more preferably 70% by area or less, and most preferably 60% by area or less. The reason for this is that: when the content is 80 area% or less, the orientation and the molecular weight distribution can be controlled, and thus an epoxy resin having characteristics which are hardly exhibited at the same time, that is, high heat resistance, low water absorption and high elastic modulus can be obtained. The lower limit value may be 0 area%, but is preferably 20 area% or more, and more preferably 40 area% or more.

In the epoxy resin of the present invention, the component n=1 in the formula (1) is preferably 80 area% or less, more preferably 70 area% or less, and most preferably 65 area% or less. The reason for this is that: when the amount is 80 area% or less, the rigidity of the molecule becomes higher, and therefore, the high elastic modulus and low water absorption are likely to be exhibited. The lower limit value may be 0 area%, but is preferably 20 area% or more, and more preferably 40 area% or more.

The epoxy resin represented by the formula (1) is more preferable when represented by the following formula (5). The reason for this is that: the isopropylidene structures and the crosslinking points are further adjacent to each other, whereby the rigidity of the molecule is improved due to the steric hindrance, and the high elastic modulus and the low water absorption are easily exhibited.

[ chemical 8]

In the formula (5), the value and preferable range of n are the same as those of the formula (1).

The method for producing the epoxy resin of the present invention is not particularly limited, and it can be obtained, for example, by subjecting the aromatic amine resin represented by the formula (6) and an epihalohydrin to addition or ring-closure reaction in the presence of a solvent or a catalyst. The amount of epihalohydrin to be used is usually 3.0 to 20.0 mol, preferably 3.5 to 10.0 mol, based on 1 mol of the amino group of the amine compound.

Examples of the alkali metal hydroxide that can be used in the epoxidation reaction include sodium hydroxide and potassium hydroxide. The alkali metal hydroxide may be a solid substance, or an aqueous solution thereof may be used. In the case of using an aqueous solution, the following method may be used: the aqueous solution of the alkali metal hydroxide is continuously added to the reaction system, and water and the epihalohydrin are continuously distilled off under reduced pressure or normal pressure, and further separated to remove water, so that the epihalohydrin is continuously returned to the reaction system. The amount of the alkali metal hydroxide to be used is usually 0.9 to 2.5 moles, preferably 0.95 to 1.5 moles, relative to 1 mole of the amino group of the amine compound. If the amount of the alkali metal hydroxide used is small, the reaction does not proceed sufficiently. On the other hand, the use of an alkali metal hydroxide in an amount exceeding 2.5 moles relative to 1 mole of the amino group of the amine compound may result in the by-production of unnecessary waste.

In order to promote the reaction, a quaternary ammonium salt such as tetramethylammonium chloride, tetramethylammonium bromide, trimethylbenzyl ammonium chloride, etc. may be added as a catalyst. The amount of the quaternary ammonium salt used is usually 0.1g to 15g, preferably 0.2g to 10g, based on 1 mol of the amino group of the amine compound. If the amount is too small, a sufficient reaction promoting effect cannot be obtained, and if the amount is too large, the amount of quaternary ammonium salt remaining in the epoxy resin increases, which may cause deterioration of electrical reliability.

In the epoxidation reaction, it is preferable to add alcohols such as methanol, ethanol and isopropanol, aprotic polar solvents such as dimethyl sulfone, dimethyl sulfoxide, tetrahydrofuran and dioxane for the reaction. In the case of using an alcohol, the amount thereof is usually 2 to 50% by weight, preferably 4 to 20% by weight, relative to the amount of epihalohydrin. In the case of using the aprotic polar solvent, the amount thereof to be used is usually 5 to 100% by weight, preferably 10 to 80% by weight, relative to the amount of the epihalohydrin to be used. The reaction temperature is usually 30℃to 90℃and preferably 35℃to 80 ℃. The reaction time is usually 0.5 to 100 hours, preferably 1 to 30 hours.

After the reaction, the reaction product is washed with water, or the epihalohydrin, the solvent, or the like is removed under reduced pressure and heating without washing with water. In order to produce an epoxy resin having less hydrolyzable halogen, the recovered epoxy resin may be dissolved in a solvent such as toluene or methyl isobutyl ketone, and an aqueous solution of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide may be added to react with each other to thereby ensure ring closure. In this case, the amount of the alkali metal hydroxide to be used is usually 0.01 to 0.3 mol, preferably 0.05 to 0.2 mol, based on 1 mol of the amino group of the amine compound used for glycidation. The reaction temperature is usually 50 to 120 ℃, and the reaction time is usually 0.5 to 24 hours. After the completion of the reaction, the produced salt is removed by filtration, washing with water or the like, and then the solvent is distilled off under reduced pressure with heating, whereby the epoxy resin of the present invention is obtained.

The epoxy resin of the present invention is usually in the form of a liquid to solid resin at ordinary temperature, and its softening point is preferably 100 ℃ or less, more preferably 80 ℃ or less. When the softening point is higher than 100 ℃, the viscosity is high, and the fiber impregnation property is reduced when the prepreg is produced. The epoxy equivalent is preferably 142g/eq to 1000g/eq, more preferably 150g/eq to 500g/eq, particularly preferably 170g/eq to 450g/eq, and most preferably 180g/eq to 400g/eq.

The epoxy resin composition of the present invention will be described below.

In the epoxy resin composition of the present invention, the epoxy resin represented by formula (1) may be used alone or in combination with other epoxy resins. In the case of using the epoxy resin represented by the formula (1) in combination, the proportion of the epoxy resin is preferably 10 to 98% by weight, more preferably 20 to 95% by weight, and still more preferably 30 to 95% by weight, based on the total amount of the epoxy resins. When the amount of the additive is 10% by weight or more, the elastic modulus can be improved and the water absorption can be reduced.

Specific examples of the other epoxy resin that can be used in combination with the epoxy resin of the present invention include: polycondensates of bisphenols (bisphenol a, bisphenol F, bisphenol S, biphenol, bisphenol AD, etc.) or phenols (phenol, alkyl-substituted phenol, aromatic-substituted phenol, naphthol, alkyl-substituted naphthol, dihydroxybenzene, alkyl-substituted dihydroxybenzene, dihydroxynaphthalene, etc.) with various aldehydes (formaldehyde, acetaldehyde, alkyl aldehyde, benzaldehyde, alkyl-substituted benzaldehyde, hydroxybenzaldehyde, naphthalene aldehyde, glutaraldehyde, phthalaldehyde, crotonaldehyde, cinnamaldehyde, etc.); polymers of the phenols with various diene compounds (dicyclopentadiene, terpenes, vinylcyclohexene, norbornadiene, vinylnorbornene, tetrahydroindene, divinylbenzene, divinylbiphenyl, diisopropenylbiphenyl, butadiene, isoprene, etc.); polycondensates of said phenols with ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone, etc.); polycondensates of the above-mentioned phenols with aromatic diols (such as xylylene glycol and biphenyldimethanol); polycondensates of the above phenols with aromatic dichloromethyl groups (α, α' -dichloroxylene, dichloromethyl biphenyl, etc.); polycondensates of the phenols with aromatic dialkoxymethyl groups (dimethoxymethylbenzene, dimethoxymethylbiphenyl, diphenoxymethylbiphenyl, etc.); the polycondensates of the bisphenol and various aldehydes or glycidyl ether-based epoxy resins, alicyclic epoxy resins, glycidyl amine-based epoxy resins, glycidyl ester-based epoxy resins, and the like obtained by glycidation of alcohols and the like are not limited to these, as long as they are epoxy resins that are generally used. These may be used alone or in combination of two or more.

Examples of the hardener that can be used in the epoxy resin composition of the present invention include: amine compounds, acid anhydride compounds, amide compounds, phenol compounds, and the like. As specific examples of the usable hardener, examples thereof include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 4' -diaminodiphenyl sulfone, 3' -diaminodiphenyl sulfone, 2' -diaminodiphenyl sulfone, diethyltoluenediamine, dimethylthiotoluenediamine, diaminodiphenylmethane, 3' -dimethyl-4, 4' -diaminodiphenylmethane, 3' -diethyl-4, 4' -diaminodiphenylmethane, 4' -diamino-3, 3' -diethyl-5, 5' -dimethyldiphenylmethane, 4' -diamino-3, 3',5,5' -tetramethyl diphenylmethane, 4' -diamino-3, 3',5,5' -tetraethyl-diphenyl-methane, 4' -diamino-3, 3',5,5' -tetraisopropyl diphenylmethane, 4' -methylenebis (N-methylaniline), bis (aminophenyl) fluorene, 3,4' -diaminodiphenyl ether, 4' -diaminodiphenyl ether, 2' -bis [4- (4-aminophenoxy) phenyl ] propane, bis [4- (4-aminophenoxy) phenyl ] sulfone, 1,3' -bis (4-aminophenoxy) benzene, 1,4' -bis (4-aminophenoxy) biphenyl, 4' - (1, 3-phenylenediisopropylidene) diphenylamine, 4' - (1, 4-phenylenediisopropylidene) diphenylamine, and, aromatic amine compounds such as naphthalene diamine, benzidine, dimethyl benzidine, and aromatic amine compounds described in Synthesis example 1 and Synthesis example 2 of International publication No. 2017/170551; aliphatic amines such as 1, 3-bis (aminomethyl) cyclohexane, isophorone diamine, 4' -methylenebis (cyclohexylamine), norbornanediamine, ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylene diamine, hexamethylenediamine, dimer diamine, triethylenetetramine, and the like, but are not limited thereto, and can be suitably used depending on the properties to be imparted to the composition. In order to ensure pot life, an aromatic amine is preferably used, and in the case where immediate hardenability is to be imparted, an aliphatic amine is preferably used. By using an amine compound containing a difunctional component as a main component as a curing agent, a network having high linearity can be constructed at the time of curing reaction, and particularly excellent toughness can be exhibited. Further, amide compounds such as dicyandiamide, and polyamide resins synthesized from dimer of linoleic acid and ethylenediamine; anhydride compounds such as phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, and methylhexahydrophthalic anhydride; bisphenol (bisphenol a, bisphenol F, bisphenol S, biphenol, bisphenol AD, etc.) or a polymer of phenols (phenol, alkyl-substituted phenol, aromatic-substituted phenol, naphthol, alkyl-substituted naphthol, dihydroxybenzene, alkyl-substituted dihydroxybenzene, dihydroxynaphthalene, etc.) with various aldehydes (formaldehyde, acetaldehyde, alkyl aldehyde, benzaldehyde, alkyl-substituted benzaldehyde, hydroxybenzaldehyde, naphthalene aldehyde, glutaraldehyde, phthalaldehyde, crotonaldehyde, cinnamaldehyde, etc.), or a polymer of phenols with various diene compounds (dicyclopentadiene, terpenes, vinylcyclohexene, norbornadiene, vinylnorbornene, tetrahydroindene, divinylbenzene, butadiene, isoprene, etc.), or a polycondensate of phenols with ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone, etc.), or a polycondensate of phenols with aromatic dimethyiols (xylylene, diphenyl dimethoxide, etc.), or a polycondensate of phenols with aromatic dichloromethyl (α, α' -dimethylbiphenyl, methyl chloride, bisphenol, etc.), a polycondensate of bisphenols with methyl, bisphenol, etc.), or a modified bisphenol, etc.; imidazole, trifluoroborane-amine complexes, guanidine derivatives, and the like, but are not limited thereto.

In the epoxy resin composition of the present invention, the amount of the hardener to be used is preferably 0.5 to 1.5 equivalents, particularly preferably 0.6 to 1.2 equivalents, relative to 1 equivalent of the epoxy group of the epoxy resin. By setting the amount to 0.5 to 1.5 equivalents, good hardening properties can be obtained.

When the hardening reaction is carried out using the hardening agent, a hardening accelerator may also be used in combination. Examples of usable hardening accelerators include: imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole, and 2-ethyl-4-methylimidazole; tertiary amines such as 2- (dimethylaminomethyl) phenol, triethylenediamine, triethanolamine, 1, 8-diazabicyclo (5, 4, 0) undecene-7; organic phosphines such as triphenylphosphine, diphenylphosphine, tributylphosphine, etc.; metal compounds such as tin octoate; tetra-substituted phosphonium tetra-substituted borates such as tetraphenylphosphonium tetra-phenylborates and tetraphenylphosphonium ethyl triphenylborates; tetraphenylboron salts such as 2-ethyl-4-methylimidazole-tetraphenylborate and N-methylmorpholine-tetraphenylborate; carboxylic acid compounds such as benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, naphthoic acid, and salicylic acid. From the viewpoint of promoting the curing reaction of the amine compound and the epoxy resin, a carboxylic acid compound such as salicylic acid is preferable. The hardening accelerator may be used in an amount of 0.01 to 15 parts by weight, as required, based on 100 parts by weight of the epoxy resin.

Further, an inorganic filler may be added to the epoxy resin composition of the present invention as needed. Examples of the inorganic filler include powders of crystalline silica, fused silica, alumina, zircon, calcium silicate, calcium carbonate, silicon carbide, silicon nitride, boron nitride, zirconia, forsterite (forsterite), steatite (steatite), spinel, titania, talc, and the like, and beads obtained by spheroidizing these, but the present invention is not limited thereto. These may be used alone or in combination of two or more. The amount of the inorganic filler used varies depending on the application, but is preferably 20% by weight or more, more preferably 30% by weight or more, particularly preferably 70% by weight to 95% by weight in terms of heat resistance, moisture resistance, mechanical properties, flame retardancy, and the like of a cured product of the epoxy resin composition when used for a sealant for a semiconductor, for example.

In the epoxy resin composition of the present invention, a release agent may be formulated in order to improve the release from the mold during molding. As the release agent, any conventionally known one can be used, and examples thereof include: ester waxes such as carnauba wax (carnauba wax) and montan wax (montan wax); fatty acids such as stearic acid and palmitic acid, and metal salts thereof; polyolefin waxes such as oxidized polyethylene and nonoxidized polyethylene. These may be used alone or in combination of two or more. The amount of these release agents to be blended is preferably 0.5 to 3% by weight based on the total organic components. If the amount is too small, the release from the mold becomes poor, and if the amount is too large, the adhesion to the lead frame or the like becomes poor.

In the epoxy resin composition of the present invention, a coupling agent may be formulated in order to improve the adhesion between the inorganic filler and the resin component. As the coupling agent, any of conventionally known ones can be used, and examples thereof include: vinyl alkoxy silane, epoxy alkoxy silane, styryl alkoxy silane, methyl acryloxy alkoxy silane, amino alkoxy silane, mercapto alkoxy silane, isocyanato alkoxy silane and other alkoxy silane compounds, alkoxy titanium compound, aluminum chelate compound, etc. These may be used alone or in combination of two or more. The method of adding the coupling agent may be to mix the inorganic filler with the resin after the surface of the inorganic filler is treated with the coupling agent in advance, or may be to mix the inorganic filler after the coupling agent is mixed with the resin.

Further, in the epoxy resin composition of the present invention, a known additive may be formulated as needed. Specific examples of the additive that can be used include: polybutadiene and its modified product, modified product of acrylonitrile copolymer, polyphenylene ether, polystyrene, polyethylene, polyimide, fluororesin, maleimide compound, cyanate ester compound, silicone gel, silicone oil, and coloring agent such as carbon black, phthalocyanine blue and phthalocyanine green.

The epoxy resin composition of the present invention is obtained by uniformly mixing the above-mentioned components. The epoxy resin composition of the present invention can be easily prepared into a cured product by the same method as the conventionally known method. For example, the epoxy resin composition of the present invention is obtained by sufficiently mixing the epoxy resin with the curing agent and, if necessary, the curing accelerator, the inorganic filler, the mold release agent, the silane coupling agent and the additive to uniformity using an extruder, a kneader, a roll or the like, molding the composition by a melt casting method, a transfer molding method, an injection molding method, a compression molding method or the like, and further heating the composition at 80 to 200℃for 2 to 10 hours, whereby a cured product can be obtained.

The epoxy resin composition of the present invention may contain a solvent as required. The cured product of the epoxy resin composition of the present invention can be produced by impregnating a fibrous substance (base material) such as glass fibers, carbon fibers, polyester fibers, polyamide fibers, alumina fibers, paper, etc. with an epoxy resin composition (epoxy resin varnish) containing a solvent, heating and drying the resultant prepreg to obtain a prepreg, and hot-press-molding the obtained prepreg. The solvent content of the epoxy resin composition is usually about 10 to 70 wt%, preferably about 15 to 70 wt% based on the internal proportion. Examples of the solvent include: gamma-butyrolactones; amide solvents such as N-methylpyrrolidone, N-dimethylformamide, N-dimethylacetamide, and N, N-dimethylimidazolidone; sulfones such as tetramethylene sulfone; ether solvents such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether acetate, and propylene glycol monobutyl ether, preferably mono-or di-lower (C1-3) alkyl ethers of lower (C1-3) alkylene glycols; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, more preferably, di-lower (C1-3) alkyl ketones having the same or different alkyl groups; aromatic solvents such as toluene and xylene. These may be used alone or in combination of two or more kinds.

The sheet-like adhesive (sheet of the present invention) can be obtained by applying the epoxy resin varnish on a release film, and removing the solvent under heating to perform B-staging. The sheet-like adhesive can be used as an interlayer insulating layer in a multilayer substrate or the like.

The cured product obtained in the present invention can be used for various applications. Specifically, general uses using thermosetting resins such as epoxy resins are exemplified by: adhesive, paint, coating agent, molding material (including sheet, film, FRP, etc.), insulating material (including printed board, wire coating, etc.), sealant, and further additives to other resins, etc.

Examples of the adhesive include: an adhesive for civil engineering, construction, automobile, general business, medical use, and an adhesive for other electronic materials. Among these, as an adhesive for electronic materials, there can be mentioned: an interlayer adhesive for a multilayer substrate such as a build-up substrate, a die-bonding agent, an adhesive for a semiconductor such as an underfill agent, etc.; and mounting adhesives such as underfill for Ball Grid Array (BGA) reinforcement, anisotropic conductive film (anisotropic conductive film, ACF), anisotropic conductive paste (anisotropic conductive paste, ACP), and the like.

As the sealant, there may be mentioned: infusion sealing, dip sealing, transfer mold sealing for capacitors, transistors, diodes, light emitting diodes, ICs, large scale integrated circuits (large scale integration circuit, LSI), etc.; perfusion sealing for ICs, LSI-like Chip On Board (COB), chip On Film (COF), tape automated bonding (tape automated bonding, TAB), and the like; underfill for flip-chip; and sealing (including reinforcing underfill) at the time of mounting an IC package such as a quad flat package (quad flat package, QFP), a Ball Grid Array (BGA), a chip size package (chip size package, CSP), or the like.

Examples

The present invention will be described more specifically by way of examples, and unless otherwise specified, parts are parts by weight. Furthermore, the present invention is not limited to these examples. In addition, in examples, the epoxy equivalent is measured by a method according to Japanese Industrial Standard (Japanese Industrial Standards, JIS) K-7236, and the softening point is measured by a method according to JIS K-7234.

GPC (gel permeation chromatography) analysis

And (3) pipe column: showa (SHODEX) GPC KF-601 (two), KF-602, KF-602.5, KF-603

Flow rate: 0.5ml/min.

Column temperature: 40 DEG C

Solvent was used: THF (tetrahydrofuran)

A detector: RI (differential refraction detector)

HPLC (high Performance liquid chromatography) analysis

And (3) pipe column: xionsil ODS-2

Flow rate: 1.0ml/min.

Column temperature: 40 DEG C

Solvent was used: acetonitrile/10 mmol/L phosphoric acid aqueous solution

A detector: light diode array (274 nm)

Synthesis example 1

While nitrogen purging was performed on a flask equipped with a thermometer, a cooling tube, a fractionating tube, and a stirrer, 559 parts of aniline, 291 parts of α, α, α ', α' -tetramethyl xylylene glycol (manufactured by Fuji-hwang film and Wako pure chemical industries, ltd.), 360 parts of toluene, and 63 parts of a 35% aqueous hydrochloric acid solution were added, and stirring was started. The internal temperature was raised to 160℃while the water produced by dehydration was withdrawn together with toluene, and the reaction was carried out for 15 hours. After cooling to room temperature, the toluene and water were returned to the system, 88 parts of 30% aqueous sodium hydroxide solution was added to neutralize. Thereafter, the organic layer was washed with water until the waste liquid became neutral, and then concentrated to obtain 458 parts of an aromatic amine resin (A1). The amine equivalent of the aromatic amine resin (A1) was 185g/eq and the softening point was 58.7 ℃. According to GPC analysis (RI), n=1 body was 61 area%, and according to HPLC analysis, 4'- (1, 3-phenylenediisopropylene) diphenylamine in n=1 body was 16.7 area%, so 4,4' - (1, 3-phenylenediisopropylene) diphenylamine in aromatic amine resin was 10.2 area%. GPC chart of the obtained amine resin (A1) is shown in FIG. 1, and ¹ the H-NMR chart (heavy chloroform) is shown in FIG. 2, and the HPLC chart is shown in FIG. 3. At the position of ¹ Signals derived from amino groups were observed at 3.05ppm to 3.65ppm of the H-NMR chart.

Example 1

186 parts of the aromatic amine resin (A1) obtained in Synthesis example 1, 555 parts of epichlorohydrin, 55 parts of methanol and 5.5 parts of water were added to a flask equipped with a thermometer, a cooling tube, a fractionating tube and a stirrer while nitrogen purging was carried out, and the mixture was reacted at 77℃for 8 hours. The internal temperature was cooled to 65℃and 81 parts of sodium hydroxide were added in portions over 90 minutes. The reaction was continued at 65℃for 3 hours, 500 parts of water was added to chlorinate the organic layerAfter sodium removal, concentration was performed under reduced pressure at 120 ℃. 300 parts of methyl isobutyl ketone (methyl isobutyl ketone, MIBK) and 40 parts of 30% aqueous sodium hydroxide solution were added thereto, and the reaction was continued at 70℃for 6 hours. After the organic layer was washed until the drainage became neutral, it was concentrated under reduced pressure at 120℃to obtain 235 parts of a semisolid epoxy resin (EP 1). The epoxy equivalent is 209.7g/eq. GPC chart of the obtained epoxy resin (EP 1) is shown in FIG. 4, and ¹ the H-NMR chart (heavy chloroform) is shown in FIG. 5, and the HPLC chart is shown in FIG. 6. At the position of ¹ Signals derived from epoxy groups were observed at 2.50ppm to 3.80ppm of the H-NMR chart. According to GPC analysis (RI), n=1 bodies were 61 area%, and according to HPLC analysis (measurement wavelength: 274 nm), 2' - (1, 3-phenylenediisopropyl) bis (diglycidyl aniline) in n=1 bodies were 31.2 area%, 2,4' - (1, 3-phenylenediisopropyl) bis (diglycidyl aniline) were 32.3 area%, and 4,4' - (1, 3-phenylenediisopropyl) bis (diglycidyl aniline) were 33.0 area%. From the above, the 2,2' - (1, 3-phenylenediisopropylene) bis (diglycidyl aniline) contained in EP1 (epoxy resin in which each isopropylidene bond is substituted at the meta position in the epoxy resin represented by formula (2)) was 19.0 area%, the 2,4' - (1, 3-phenylenediisopropylene) bis (diglycidyl aniline) (epoxy resin in which each isopropylidene bond is substituted at the meta position in the epoxy resin represented by formula (3)) was 19.7 area%, and the 4,4' - (1, 3-phenylenediisopropylene) bis (diglycidyl aniline) (epoxy resin in which each isopropylidene bond is substituted at the meta position in the epoxy resin represented by formula (4)) was 20.1 area%.

Reference example 1

150 parts of 4,4' - (1, 3-phenylenediisopropylidene) diphenylamine (manufactured by tokyo chemical Co., ltd.), 483 parts of epichlorohydrin, 17 parts of methanol, and 5 parts of water were added to a flask equipped with a thermometer, a cooling tube, a fractionating tube, and a stirrer, followed by nitrogen purging, and the mixture was reacted at 80℃for 3 hours. The internal temperature was cooled to 65℃and 70.3 parts of sodium hydroxide were added in portions over 90 minutes. The reaction was continued at 65℃for 3 hours, 400 parts of water was added, and the organic layer was freed from sodium chloride and concentrated under reduced pressure at 120 ℃. Adding 300 parts of MIBK and 40 parts of 30% sodium hydroxide aqueous solution, and continuing at 70 DEG CThe reaction was continued for 20 hours. After the organic layer was washed until the water discharge became neutral, the organic layer was concentrated under reduced pressure at 120℃to obtain 213 parts of a liquid epoxy resin (EP 2). The epoxy equivalent was 160.3g/eq. GPC chart of the obtained epoxy resin (EP 2) is shown in FIG. 7, wherein ¹ The H-NMR chart (heavy chloroform) is shown in FIG. 8, and the HPLC chart is shown in FIG. 9. At the position of ¹ Signals derived from epoxy groups were observed at 2.50ppm to 3.80ppm of the H-NMR chart. According to GPC analysis (RI), n=1 bodies were 90.2 area%, and according to HPLC analysis (measurement wavelength: 274 nm), 4' - (1, 3-phenylenediisopropyl) bis (diglycidyl aniline) in n=1 bodies was 100 area%. From the above, the content of 4,4' - (1, 3-phenylenediisopropyl) bis (diglycidyl aniline) in EP2 (epoxy resin in which each isopropylidene bond is substituted at the meta position in the epoxy resin represented by formula (4)) was 90.2 area%.

[ example 2, comparative example 1, comparative example 2]

The epoxy resins (EP 1 and EP 2) and the epoxy resins (EP 3; RE-304S, manufactured by Japanese chemical Co., ltd.) obtained in example 1 and reference example 1, and 4,4 '-methylenebis (2, 6-diethylaniline) (manufactured by Tokyo chemical Co., ltd., abbreviation: MDEA (4, 4' -methyl-bis (2, 6-dimethyllaniline)) as a curing agent were used, and were blended at the ratio (parts by weight) shown in Table 1, uniformly mixed and kneaded by using a mixing roll, and cured at 160℃for 6 hours at 180℃after demolding, to obtain test pieces for evaluation.

< measurement of hardening Properties >

The results of measurement of the test piece for evaluation under the following conditions are shown in table 1.

< glass transition temperature >

The measurement was carried out in accordance with JIS K-7244. The peak top temperature of tan delta was set as Tg.

Dynamic viscoelasticity tester: TA-instruments, dynamic thermo-mechanical Analyzer (dynamic thermomechanical analyzer, DMA) -2980

Sample size: 20mm by 5mm by 1mm

Temperature increase rate: 10 ℃/min

Bending strength, bending elasticity >

The measurement was carried out in accordance with JIS K-6911.

Teng Xilong (Tensilon): RTG-1310 (manufactured by A & D Company, limited)

Measurement temperature: room temperature

< Water absorption Rate >)

The mass change of a test piece having a disk shape with a diameter of 5cm by a thickness of 4mm was calculated by maintaining the test piece in a water-immersed condition at 100℃for 24 hours.

TABLE 1

From the results of table 1, it was confirmed that example 2 had high heat resistance, high flexural strength, high elastic modulus, and low water absorption.

Industrial applicability

The epoxy resin of the present invention is useful for applications such as insulating materials (high-reliability semiconductor sealing materials, etc.) for electric and electronic parts, laminated boards (printed wiring boards, BGA substrates, build-up substrates, etc.), adhesives (conductive adhesives, etc.), various composite materials typified by CFRP, and paints, and is particularly useful for applications of various composite materials typified by CFRP, which strongly requires a high elastic modulus.

Claims

1. An epoxy resin represented by the following formula (1),

the total content of the epoxy resins represented by the following formulas (2) to (4) is 80 area% or less in the epoxy resin represented by the following formula (1),

[ chemical 1]

(in the formula (1), n is a repetition number, and the average value is 1 < n < 5)

[ chemical 2]

2. The epoxy resin according to claim 1, wherein the component of n=1 in the formula (1) is 80 area% or less.

3. The epoxy resin according to claim 1 or 2, represented by the following formula (5),

[ chemical 3]

In the formula (5), n is a repetition number, and the average value is 1 < n < 5).

4. A curable resin composition comprising the epoxy resin according to any one of claims 1 to 3.

5. The curable resin composition according to claim 4, further comprising a hardener.

6. A cured product obtained by curing the curable resin composition according to claim 4 or 5.