JPWO2018139112A1 - Epoxy resin, epoxy resin composition containing the same, and cured product using the epoxy resin composition - Google Patents

Abstract

An object of the present invention is to provide an epoxy resin in which the obtained cured product is excellent in heat resistance and toughness. Specifically, an epoxy resin which is a reaction product of 1,6-dihydroxynaphthalene and epihalohydrin, wherein the epoxy resin is a trifunctional epoxy represented by the following chemical formula (1) and / or chemical formula (2) It is an epoxy resin which contains a compound and whose content of the said trifunctional epoxy compound is 5.0 mass% or less with respect to solid content of an epoxy resin.

Description

  The present invention relates to an epoxy resin, an epoxy resin composition containing the same, and a cured product using the epoxy resin composition.

  An epoxy resin is a curable resin which contains an epoxy group in the molecule and can be cured by forming a crosslinked network with the epoxy group. A cured product of epoxy resin has excellent mechanical strength, heat resistance, water resistance, insulation properties, etc., and is therefore used for matrix of fiber reinforced composite material, heat dissipation member, adhesive, paint, semiconductor, printed wiring board etc. Has been applied.

  In recent years, epoxy resins have been provided for various uses. For example, in the use of fiber-reinforced composite materials, their use has been expanded, for example, their characteristics such as excellent heat resistance and excellent mechanical strength are attracting attention, though they are lightweight. . Along with this, the required characteristics of the cured product of the epoxy resin are improved, and the higher performance of the epoxy resin is required.

  For example, Patent Document 1 describes an epoxy resin obtained by reacting dihydroxy naphthalenes with epihalohydrin. According to Patent Document 1, when using an epoxy resin composition comprising an epoxy resin of the specific structure, a predetermined curing agent and a predetermined inorganic filler, it is described that the cured product is excellent in heat conduction. ing.

  In addition, it is described that the epoxy resin of patent document 1 is obtained by making dihydroxy naphthalenes and epihalohydrin react, and epoxidizing.

JP, 2013-60607, A

  Although the epoxy resin described in Patent Document 1, that is, the epoxy resin obtained by reacting dihydroxynaphthalenes and epihalohydrin, the cured product has a certain thermal conductivity, it has sufficient heat resistance and toughness. It turned out that there may not be.

  Then, this invention aims at providing the epoxy resin which the hardened | cured material obtained is excellent in heat resistance and toughness.

  The present inventors diligently conducted research to solve the above-mentioned problems. As a result, it is found that the above problems can be solved by controlling the content of a predetermined component of a composition obtained by using a predetermined dihydroxy naphthalene and reacting with an epihalohydrin, and the present invention is completed. The

  That is, the present invention relates to an epoxy resin which is a reaction product of 1,6-dihydroxynaphthalene and epihalohydrin. At this time, the epoxy resin contains a trifunctional epoxy compound represented by the following chemical formula (1) and / or chemical formula (2), and the content of the trifunctional epoxy compound is relative to the solid content of the epoxy resin: It is characterized by being 5.0 mass% or less.

  According to the present invention, an epoxy resin is provided in which the resulting cured product is excellent in heat resistance and toughness.

  Hereinafter, modes for carrying out the present invention will be described in detail.

<Epoxy resin>
The epoxy resin which concerns on this form is a reaction product of 1, 6- dihydroxy naphthalene and epihalohydrin.

  The reaction of 1,6-dihydroxynaphthalene with epihalohydrin generally proceeds with glycidyl etherification reaction at the 1- and 6-position hydroxy groups of 1,6-dihydroxynaphthalene. However, various other reactions may proceed, and as a result, the reaction product of 1,6-dihydroxynaphthalene and epihalohydrin may contain various epoxy compounds. The physical properties of the epoxy resin which is such a reaction product and the physical properties of its cured product are limited to only the bifunctional epoxy compound which can be the main component such as 1,6-bis (2,3-epoxypropan-1-yloxy) naphthalene. It may not be affected by other epoxy compounds.

  The epoxy resin which concerns on this form controls the content of the said trifunctional epoxy compound paying attention to the predetermined | prescribed trifunctional epoxy compound which may be contained in a reaction product. Thereby, the hardened | cured material obtained is excellent in heat resistance and toughness.

[1,6-dihydroxy naphthalene]
1,6-dihydroxy naphthalene is represented by the following chemical formula.

[Epihalohydrin]
The epihalohydrin is not particularly limited, and examples thereof include epichlorohydrin, epibromohydrin, epiiodohydrin and the like. These epihalohydrins may be used alone or in combination of two or more.

  Although the addition amount of epihalohydrin is not particularly limited, it is preferably 1.5 to 10.0 mol and is 2.0 to 7.5 mol with respect to 1 mol of hydroxy group of 1,6-dihydroxynaphthalene. Is more preferred. It is preferable that the addition amount of epihalohydrin is 1.5 mol or more because a low viscosity epoxy resin having a small amount of oligomer components can be produced. On the other hand, it is preferable that the addition amount of epihalohydrin is 10.0 mol or less, because the amount of excess epihadhydrin which becomes unnecessary after the reaction can be reduced.

[reaction]
The reaction of 1,6-dihydroxynaphthalene with epihalohydrin is not particularly limited and can be carried out by known methods. In one embodiment, the reaction comprises the step (1) of reacting a mixture containing 1,6-dihydroxynaphthalene and epihalohydrin in the presence of a basic compound. At this time, if necessary, the obtained reactant may further include the step (2) of reacting in the presence of a basic compound.

(Step (1))
Step (1) is a step of reacting a mixture containing 1,6-dihydroxynaphthalene and epihalohydrin in the presence of a basic compound.

  The mixture comprises 1,6-dihydroxynaphthalene and epihalohydrin. In addition, if necessary, a solvent, a basic compound and the like may further be included.

1,6-Dihydroxynaphthalene and Epihalohydrin The 1,6-dihydroxynaphthalene and the epihalohydrin are as described above, and thus the description thereof is omitted here.

Solvent The solvent is not particularly limited, and examples thereof include alcohols such as methanol, ethanol, isopropyl alcohol and butanol; ketones such as acetone and methyl ethyl ketone; ethers such as dioxane; dimethyl sulfone and dimethyl sulfoxide. These solvents may be used alone or in combination of two or more.

  The addition amount of the solvent is preferably 5 to 100% by mass, more preferably 5 to 60% by mass, and still more preferably 5 to 50% by mass with respect to the addition amount of the epihalohydrin. And 10 to 30% by mass is particularly preferable.

Basic compound The basic compound has a function of promoting a nucleophilic reaction and a ring closure reaction of 1,6-dihydroxynaphthalene with an epihalohydrin.

  The basic compound is not particularly limited, and examples thereof include potassium hydroxide, sodium hydroxide, barium hydroxide, magnesium oxide, sodium carbonate, potassium carbonate and the like. Among these, potassium hydroxide and sodium hydroxide are preferably used. These basic compounds may be used alone or in combination of two or more.

Reaction The reaction is typically a first reaction (nucleophilic reaction) of 1,6-dihydroxynaphthalene with epihalohydrin and a second reaction (cyclization of the resulting halo alcohol) as shown below. Reaction).

  The first reaction and the second reaction may be allowed to proceed simultaneously or sequentially. From the viewpoint of efficiently performing the reaction, the first reaction and the second reaction are preferably allowed to proceed sequentially. At this time, it is preferable to perform the second reaction as the main reaction by removing the epihalohydrin after performing the first reaction as the main reaction.

  Although the addition amount of the basic compound in the case of performing the first reaction is not particularly limited, it is preferably 0.05 to 0.7 mol with respect to 1 mol of 1,6-dihydroxynaphthalene. It is more preferable that it is -0.5 mol.

  The reaction temperature in the case of carrying out the first reaction is not particularly limited, but is preferably 20 to 120 ° C., and more preferably 30 to 80 ° C.

  The reaction time for carrying out the first reaction is not particularly limited, but is preferably 2 to 7 hours.

  In addition, the addition amount of the basic compound in the case of performing the second reaction is not particularly limited, but is preferably 0.4 to 3.0 mol with respect to 1 mol of 1,6-dihydroxynaphthalene, and 0 More preferably, it is from 6 to 2.0 moles.

  The reaction temperature in the case of carrying out the second reaction is not particularly limited, but is preferably 20 to 120 ° C., and more preferably 30 to 80 ° C.

  The reaction time for carrying out the second reaction is not particularly limited, but is preferably 1 to 10 hours.

(Step (2))
Step (2) is a step of reacting the reaction product obtained in step (1) in the presence of a basic compound. In the reaction product obtained in the step (1), the second reaction described above may not proceed, and the unreacted haloalcohol obtained by the first reaction may remain. By performing step (2), such unreacted haloalcohols can be ring-closed to eliminate or reduce the unreacted haloalcohols in the epoxy resin.

  About the process (2), the addition amount of a basic compound, reaction temperature, and reaction time are the same as that of the above-mentioned 2nd reaction.

  From the viewpoint of suitably performing step (2), it is preferable to remove epihalohydrin and the like from the reaction product obtained in step (1) before performing step (2).

[Product of reaction]
The reaction product contains an epoxy compound. Also, the reaction product may contain a solvent and other compounds.

  In addition, the said epoxy compound mainly contains a bifunctional epoxy compound. In addition, monofunctional epoxy compounds, trifunctional epoxy compounds, polyfunctional epoxy compounds, and oligomers of epoxy compounds may be included.

(Bifunctional epoxy compound)
The bifunctional epoxy compound is one obtained by introducing two glycidyl ether groups into 1,6-dihydroxynaphthalene. Although it does not restrict | limit especially as the specific example, The compound represented by following Chemical formula (3) is mentioned.

(Monofunctional epoxy compound)
The monofunctional epoxy compound is obtained by introducing one glycidyl ether group into 1,6-dihydroxynaphthalene. Although it does not restrict | limit especially as the specific example, The compound represented by following formula is mentioned.

(Trifunctional epoxy compound)
The trifunctional epoxy compound is obtained by introducing three glycidyl ether groups into 1,6-dihydroxynaphthalene. Specific examples thereof include, but are not particularly limited to, compounds represented by chemical formulas (1) and (2).

(Multifunctional epoxy compound)
The polyfunctional epoxy compound is one in which four or more glycidyl ether groups are introduced into 1,6-dihydroxynaphthalene. Although it does not restrict | limit especially as the specific example, The compound represented by following formula is mentioned.

(Oligomer)
The oligomer is obtained by further reacting at least one of a monofunctional epoxy compound, a bifunctional epoxy compound, a trifunctional epoxy compound, and a polyfunctional epoxy compound with 1,6-dihydroxynaphthalene.

  The oligomer is not particularly limited, and examples thereof include an oligomer represented by the following formula, which is obtained by reacting a bifunctional epoxy compound represented by the chemical formula (3) with 1,6-dihydroxynaphthalene.

  In the above formula, n is 1 or more, preferably 1 to 5.

(solvent)
The solvent is not particularly limited, and includes, in addition to the solvent used for the above-mentioned reaction, water, a solvent and the like which can be intentionally added in the purification step and the like.

(Other compounds)
The other compounds are not particularly limited, and include compounds other than epoxy compounds produced by the reaction of 1,6-dihydroxynaphthalene and epihalohydrin. Specifically, unreacted 1, 6-dihydroxy naphthalene, unreacted epihalohydrin, unreacted basic compound, and compounds derived therefrom (by-products and the like) can be mentioned.

  In addition, since the conditions of the reaction are usually controlled or purified, the contents of other compounds tend to be low.

[Epoxy resin composition]
The epoxy resin which concerns on this form is an above-mentioned reaction product. Under the present circumstances, an epoxy resin contains the trifunctional epoxy compound represented by said Chemical formula (1) and / or (2).

  Content of the said trifunctional epoxy compound is 5.0 mass% or less with respect to solid content of an epoxy resin, Preferably it is 3.0 mass% or less, More preferably, it is 0.01-3.0 mass. %, More preferably 0.03 to 2.0% by mass. At this time, when the epoxy resin contains both the trifunctional epoxy compound represented by the chemical formula (1) and the trifunctional epoxy compound represented by the chemical formula (2), the total value of these contents is the above content. It should be satisfied. In the present specification, “solid content of epoxy resin” means the total mass of components excluding the solvent in the epoxy resin. Therefore, when the epoxy resin does not contain a solvent, the total mass of the epoxy resin corresponds to the solid content.

  The trifunctional epoxy compound has three functional groups. By containing such a trifunctional epoxy compound in the epoxy resin, the resulting cured product can have high heat resistance and high strength. In addition, by setting the content of the trifunctional epoxy resin to 5.0% by mass or less, the decrease in elongation can be suppressed or prevented, and as a result, high toughness can be obtained.

  The content of the bifunctional epoxy compound in the epoxy resin is preferably 30 to 97% by mass, and more preferably 50 to 95% by mass, with respect to the total mass of the epoxy compound. When the content of the bifunctional epoxy compound is 30% by mass or more, it is preferable because the viscosity can be reduced. On the other hand, the content of the bifunctional epoxy compound is preferably 97% by mass or less because heat resistance can be increased.

  The content of the monofunctional epoxy compound in the epoxy resin is preferably 2 to 15% by mass, and more preferably 4 to 10% by mass, with respect to the total mass of the epoxy compound. It is preferable from the ability to make viscosity low that content of a monofunctional epoxy compound is 2 mass% or more. On the other hand, the content of the monofunctional epoxy compound is preferably 15% by mass or less because heat resistance can be increased.

  The content of the polyfunctional epoxy compound in the epoxy resin is preferably 2 to 10% by mass, and more preferably 2 to 8% by mass, with respect to the total mass of the epoxy compound. It is preferable from the ability to make heat resistance high that content of a polyfunctional epoxy compound is 2 mass% or more. On the other hand, it is preferable from the ability to make viscosity low that content of a polyfunctional epoxy compound is 10 mass% or less.

  It is preferable that it is 4-40 mass% with respect to the total mass of an epoxy compound, and, as for content of the oligomer in an epoxy resin, it is more preferable that it is 5-30 mass%. It is preferable from the point which is excellent in toughness that content of an oligomer is 4 mass% or more. On the other hand, it is preferable from the ability to make viscosity low that content of an oligomer is 40 mass% or less.

  It is preferable that it is 5 mass% or less, and, as for the other compound in an epoxy resin, it is more preferable that it is 0.05-5 mass%.

  In addition, in this specification, content of each component in an epoxy resin shall employ | adopt the value measured by the method of the high performance liquid chromatography (HPLC) as described in an Example.

  Adjustment of the content of the component in the epoxy resin may be performed by control of the reaction and control of the purification step, or may be performed by adding a component separately. Under the present circumstances, it is preferable to control reaction and to adjust content of the component of an epoxy resin from a viewpoint which can prepare an epoxy resin efficiently. The content of the component of the epoxy resin can be adjusted by controlling the reaction, for example, by appropriately changing the addition amount of the epihalohydrin, the reaction temperature, the reaction time, the evaporation of the epihalohydrin, and the like.

  The epoxy equivalent of the epoxy resin is not particularly limited, but is preferably 130 to 220 g / equivalent (Eq.), Preferably 135 to 200 g / Eq. It is more preferable that Epoxy equivalent is 130 g / Eq. It is preferable from the ability to make viscosity low as it is more than. On the other hand, epoxy equivalent is 220 g / Eq. It is preferable from the ability to make heat resistance high as it is the following. In addition, the value of "epoxy equivalent" shall employ | adopt the value measured by the method described in the Example in this specification.

  The viscosity of the epoxy resin is not particularly limited, but is preferably 500 to 1700 mPa · s, and more preferably 650 to 1500 mPa · s. It is preferable from the ability to suppress the sag at the time of shaping | molding that the viscosity of an epoxy resin is 500 mPa * s or more. On the other hand, when the viscosity of the epoxy resin is 1700 mPa · s or less, it is preferable because the impregnating property to the reinforcing fiber is excellent. In addition, the value of the "viscosity of an epoxy resin" shall employ | adopt the value measured by the method described in the Example in this specification.

<Epoxy resin composition>
According to one aspect of the present invention, an epoxy resin composition is provided. The epoxy resin composition contains the above-described epoxy resin and a curing agent. The epoxy resin composition may further contain other epoxy resins, other resins, curing accelerators, organic solvents, inorganic fillers, additives, etc., as necessary.

[Epoxy resin]
As the epoxy resin may be used as described above, the description is omitted here.

  It is preferable that it is 30-99 mass% with respect to solid content of a resin composition, and, as for content of an epoxy resin, it is more preferable that it is 40-97 mass%. When the content of the epoxy resin is 30% by mass or more, it is preferable because the performance of the epoxy resin is easily expressed. On the other hand, it is preferable from the option of a hardening agent spreading that content of an epoxy resin is 99 mass% or less. In addition, in this specification, "solid content of a resin composition" means the gross mass of the component except the organic solvent mentioned later in a composition. Thus, when the resin composition does not contain a solvent, the total mass of the composition corresponds to the solid content.

[Other epoxy resin]
Another epoxy resin is an epoxy resin containing epoxy compounds other than the epoxy compound contained in the above-mentioned epoxy resin.

  Specifically, a reaction product of substituted 1,6-dihydroxynaphthalene with epihalohydrin or substituted epihalohydrin, substituted or unsubstituted 1,4-dihydroxynaphthalene, substituted or unsubstituted 1,5-dihydroxynaphthalene, Examples thereof include reaction products of substituted or unsubstituted 2,6-dihydroxynaphthalene, substituted or unsubstituted 2,7-dihydroxynaphthalene, and epihalohydrin or substituted epihalohydrin.

  In this case, “substituted” means that at least one of the hydrogen atoms bonded to naphthalene of dihydroxy naphthalene is substituted by a substituent. At this time, the “substituent” refers to methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, decyl and the like. Alkyl group having 1 to 10 carbon atoms; cycloalkyl group having 3 to 10 carbon atoms such as cyclopropyl group, cyclobutyl group, methylcyclobutyl group, cyclopentyl group, cyclohexyl group, cyclodecyl group, etc .; vinyl group, allyl group, butenyl Group, alkenyl group having 2 to 10 carbon atoms such as octenyl group; alkynyl group having 2 to 10 carbon atoms such as propargyl group and butynyl group; 1 to 10 carbon atoms such as methoxy group, ethoxy group and propyloxy group Alkyloxy group having 2 to 10 carbon atoms such as acetyl and ethyl carbonyl; Aryl group having 6 to 10 carbon atoms such as nyl group, tolyl group, xylyl group, chlorophenyl group, etc .; aralkyl group having 7 to 10 carbon atoms such as benzyl group; fluorine atom, chlorine atom, bromine atom, iodine atom etc. A halogen atom etc. are mentioned. These substituents may be present singly or in combination of two or more.

  Further, “substituted epihalohydrin” is not particularly limited, but means that at least one of the hydrogen atoms constituting the epihalohydrin is substituted by a substituent, and specifically, 3-chloro-2-methyl-1, 2-epoxypropane, 3-chloro-3-methyl-1,2-epoxypropane, 3-chloro-2-ethyl-1,2-epoxypropane, 3-chloro-3-ethyl-1,2-epoxypropane, 3-chloro-2-propyl-1,2-epoxypropane, 3-chloro-3-propyl-1,2-epoxypropane and the like can be mentioned.

  In addition, the other epoxy resin may be an epoxy resin other than an epoxy resin containing a dihydroxy naphthalene skeleton. Such an epoxy resin is not particularly limited, but is a bisphenol type epoxy resin such as bisphenol A type epoxy resin and bisphenol F type epoxy resin; biphenyl type epoxy resin such as biphenyl type epoxy resin and tetramethylbiphenyl type epoxy resin; phenol Novolac epoxy resin, cresol novolac epoxy resin, bisphenol A novolac epoxy resin, epoxidized product of condensation product of phenols and aromatic aldehyde having phenolic hydroxyl group, novolac epoxy resin such as biphenyl novolac epoxy resin; tri Phenylmethane type epoxy resin; tetraphenylethane type epoxy resin; dicyclopentadiene-phenol addition reaction type epoxy resin; phenol aralkyl type epoxy resin; Runoborakku type epoxy resin, naphthol aralkyl type epoxy resin, naphthol - phenol co-condensed novolak type epoxy resin, naphthol - cresol co-condensed novolac type epoxy resin, diglycidyl oxy naphthalene, phosphorus-containing epoxy resin and the like.

  The other epoxy resins described above may be used alone or in combination of two or more.

[Other resin]
Other resins mean resins other than epoxy resin. The other resin may be a thermosetting resin or a thermoplastic resin. Specific examples of other resins are not particularly limited, and polycarbonate resins, polyphenylene ether resins, polyethylene terephthalate resins, polybutylene terephthalate resins, polyethylene resins, polypropylene resins, polyimide resins, polyamideimide resins, polyetherimide resins, polyether Sulfone resin, polyketone resin, polyether ketone resin, polyether ether ketone resin, phenol resin are mentioned. These other resins may be used alone or in combination of two or more.

[Hardener]
The curing agent is not particularly limited, and examples thereof include amine compounds, amide compounds, acid anhydride compounds, and phenol compounds.

Examples of the amine compounds include ethylenediamine, diaminopropane, butane, diethylenetriamine, triethylenetetramine, 1,4-cyclohexanediamine, isophoronediamine, diaminodicyclohexylmethane, diaminodiphenylmethane, diaminodiphenylsulfone, phenylenediamine, imidazole and BF. _{And 3} -amine complexes, guanidine derivatives and the like.

  Examples of the amide compound include dicyandiamide, and a polyamide resin synthesized from a dimer of linolenic acid and ethylene diamine.

  Examples of the acid anhydride-based compound include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methyl nadic anhydride, hexahydrophthalic anhydride, methyl hexameric anhydride. Hydrophthalic anhydride etc. are mentioned.

  As said phenol type compound, phenol novolak resin, cresol novolak resin, aromatic hydrocarbon formaldehyde resin modified phenol resin, dicyclopentadiene phenol addition type resin, phenol aralkyl resin, α-naphthol aralkyl resin, β-naphthol aralkyl resin, biphenyl Aralkyl resin, trimethylol methane resin, tetraphenylol ethane resin, naphthol novolac resin, naphthol-phenol co-convoluted novolak resin, naphthol-cresol co-convoluted novolac resin, and amino group-containing triazine compounds (melamine, benzoguanamine etc.) and phenols The amino triazine modified | denatured phenol resin etc. which are copolymers of phenol, cresol etc. and formaldehyde are mentioned.

  Among them, amine compounds and phenol compounds are preferably used, and diaminodiphenyl sulfone, phenol novolak resin, cresol novolac resin, phenol aralkyl resin, α-naphthol aralkyl resin, β-naphthol aralkyl resin, biphenyl aralkyl resin, amino It is more preferred to use a triazine modified phenolic resin.

  The above-mentioned cured products may be used alone or in combination of two or more.

  The content of the curing agent is preferably 1 to 70% by mass, and more preferably 3 to 60% by mass, with respect to the solid content of the resin composition. It is preferable from the option of a hardening agent spreading that content of a hardening agent is 1 mass% or more. On the other hand, when the content of the curing agent is 70% by mass or less, it is preferable because the performance of the epoxy resin is easily expressed.

[Hardening accelerator]
The curing accelerator has a function to accelerate curing. Thereby, the reaction time can be shortened, and the generation or the like of the unreacted epoxy compound can be prevented or reduced.

  The curing accelerator is not particularly limited, and examples thereof include phosphorus compounds, tertiary amines, imidazoles, organic acid metal salts, Lewis acids, amine complexes, urea derivatives and the like. Among these, imidazoles are preferably used. These curing accelerators may be used alone or in combination of two or more.

  The content of the curing accelerator is preferably 0.1 to 10% by mass, and more preferably 0.5 to 5% by mass, with respect to the solid content of the resin composition. It is preferable from the ability to accelerate | stimulate hardening as content of a hardening accelerator is 0.1 mass% or more. On the other hand, it is preferable from the ability to lengthen pot life that content of a hardening accelerator is 10 mass% or less.

[Organic solvent]
The organic solvent has a function of adjusting the viscosity of the epoxy resin composition. Thereby, the impregnating ability to a base material etc. can be improved.

  The organic solvent is not particularly limited, but ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, carbitol acetate, ethyl diglycol acetate, propylene glycol Acetic esters such as monomethyl ether acetate; Alcohols such as isopropyl alcohol, butanol, cellosolve and butyl carbitol; Aromatic hydrocarbons such as toluene and xylene; Amides such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone Can be mentioned. Among these, alcohols and ketones are preferably used, and butanol and methyl ethyl ketone are more preferably used. These solvents may be used alone or in combination of two or more.

  The content of the organic solvent is preferably 10 to 60% by mass, and more preferably 20 to 50% by mass with respect to the solid content of the epoxy resin. It is preferable from the ability to make viscosity low that content of an organic solvent is 10 mass% or more. On the other hand, it is preferable from the ability to reduce a non-volatile component that content of an organic solvent is 60 mass% or less.

[Inorganic filler]
The inorganic filler has a function of preventing an increase in melt viscosity.

  The inorganic filler is not particularly limited, and examples thereof include fused silica, silica such as crystalline silica, aluminum oxide, silicon nitride, aluminum nitride and the like. Among these, it is preferable to use silica, and it is more preferable to use fused silica. These inorganic fillers may be used alone or in combination of two or more.

  The content of the inorganic filler is preferably 20 to 80% by mass, and more preferably 20 to 60% by mass, with respect to the solid content of the epoxy resin. It is preferable from the ability to make an elastic modulus high as content of an inorganic filler is 20 mass% or more. On the other hand, it is preferable from the ability to make viscosity low that content of an inorganic filler is 80 mass% or less.

[Additive]
The additives which may be contained in the epoxy resin composition are not particularly limited, but reinforcing fibers, flame retardants, mold release agents, pigments, antioxidants, UV absorbers, light stabilizers, antistatic agents, conductivity imparting agents Etc. These additives may be used alone or in combination of two or more.

[Use]
In one embodiment, the epoxy resin composition can be applied to applications such as fiber reinforced composite materials, adhesives, and paints. Hereinafter, the application of the fiber reinforced composite material will be described in detail.

  The fiber reinforced composite material is a sheet-like intermediate material in which an epoxy resin composition is impregnated into reinforcing fibers.

  The raw material of the reinforcing fiber is not particularly limited, but carbon fibers such as polyacrylonitrile carbon fiber, pitch carbon fiber, rayon carbon fiber, glass fiber, aramid fiber, boron fiber, alumina fiber, silicon carbide fiber and the like are mentioned. Be Among these, it is preferable to use carbon fiber.

  The form of the reinforcing fiber includes twisted yarn, untwisted yarn, non-twisted yarn and the like. Among these, untwisted yarn and non-twisted yarn are preferable because they have excellent formability. In addition, the form of the reinforcing fiber may be one in which the fiber direction is aligned in one direction, or may be a woven fabric such as plain weave or satin weave.

  The above-mentioned reinforcing fibers may be used alone or in combination of two or more.

  The content of reinforcing fibers in the fiber-reinforced composite material is preferably 40 to 85% by volume with respect to the total volume of the fiber-reinforced composite material, and more preferably 50 to 70% by volume from the viewpoint of excellent strength. preferable. The flame retardance of the hardened | cured material obtained is acquired as the content rate of a reinforced fiber is 40 volume% or more, and it is preferable from a viewpoint which is excellent in physical properties, such as a specific elastic modulus and a specific strength. On the other hand, the adhesiveness of an epoxy resin composition and a reinforced fiber becomes favorable for the content rate of a reinforced fiber to be 85 volume% or less, for example, when laminating a prepreg, it is preferable from the ability to prevent delamination of a prepreg.

  The degree of impregnation of the reinforcing fiber of the epoxy resin composition in the fiber-reinforced composite material is not particularly limited, either, and the epoxy resin composition may be impregnated to the inside of the fiber bundle of the reinforcing fiber or near the surface of the sheet-like fiber It may be localized.

  The method for producing the fiber-reinforced composite material is not particularly limited, and any known method may be employed as appropriate. Specifically, a wet method or a hot melt method may be mentioned.

  In the wet method, a varnish is prepared by uniformly mixing the components contained in the epoxy resin composition, and then impregnated while being immersed in a sheet-like fiber made of reinforcing fiber, and the organic solvent is evaporated in an oven or the like to make the fiber It is a method of obtaining a reinforced composite material.

  In the hot melt method, the epoxy resin composition is reduced in viscosity by heating without using an organic solvent to form a film on a roll or release paper, and then from both sides or one side of a sheet-like fiber made of reinforcing fibers It is the method of making it impregnate by overlapping and heating and pressurizing a film.

  Under the present circumstances, in the hot melt method, it is preferable that it is 50-250 degreeC, and, as for the temperature of the resin composition at the time of impregnating a reinforced fiber, it is more preferable that it is 50-100 degreeC. It is preferable from the fact that the temperature of the resin composition at the time of impregnation is 50 ° C. or more, since the reinforcing fiber is easily impregnated. On the other hand, when the temperature of the resin composition at the time of impregnation is 250 ° C. or less, it is preferable because an increase in the glass transition temperature due to the progress of a partial curing reaction can be suppressed and appropriate drapability can be maintained.

  Among the above, it is preferable to use a hot melt method which does not generate a residual organic solvent.

<Cured product>
According to one aspect of the present invention, a cured product is provided. The cured product is obtained by curing the above-mentioned epoxy resin composition. The cured product has high heat resistance and high toughness.

  The shape of the cured product is not particularly limited, and may be a sheet shape, or may be a shape in which the cured product is impregnated with another material (such as a fibrous reinforcing material).

  The glass transition point (Tg) of the cured product is not particularly limited, but is preferably 200 to 270 ° C., and more preferably 200 to 250 ° C. It is preferable from the ability to make heat resistance high that a glass transition point (Tg) is 200 degreeC or more. On the other hand, it is preferable from the point which is excellent in toughness that a glass transition point (Tg) is 270 degrees C or less. In addition, the value of the "glass transition point (Tg)" shall employ | adopt the value measured by the method described in the Example in this specification.

  The curing temperature of the epoxy resin composition is preferably 50 to 250 ° C, and more preferably 70 to 200 ° C. When the curing temperature is 50 ° C. or higher, the curing reaction can be rapidly performed, which is preferable. On the other hand, if curing temperature is 250 degrees C or less, it is preferable from the ability to suppress the energy amount required at the time of hardening.

  In one embodiment, the above-mentioned cured product can be applied to uses such as a fiber reinforced resin molded product, a heat dissipation member, a semiconductor, a printed wiring board and the like. Hereafter, the case where it applies to a fiber reinforced resin molded product is demonstrated in detail.

  The fiber-reinforced resin molded product is a cured product of the above-described fiber-reinforced composite material.

  The content of reinforcing fibers is preferably 40 to 85% by volume, and more preferably 50 to 70% by volume from the viewpoint of strength, with respect to the total volume of the fiber-reinforced resin molded product.

  The method for producing a fiber-reinforced resin molded article is not particularly limited, but after cutting a fiber-reinforced composite material into a predetermined size, a method of curing an epoxy resin composition while applying heat and pressure to a laminate obtained by laminating a predetermined number of sheets. Can be mentioned.

  The heat curing method is not particularly limited, and examples thereof include a press molding method, an autoclave molding method, a bagging molding method, a wrapping tape method, an internal pressure molding method and the like.

  For example, in the case of producing a plate-like fiber-reinforced resin molded product as the above-mentioned production method, first, a sheet-like fiber-reinforced composite material is cut into a predetermined size, and then a predetermined number of sheets on a rigid tool Laminate and seal with flexible film. Next, the space between the rigid tool and the flexible film is evacuated by a vacuum pump. And after installation in an autoclave, a fiber reinforced resin molded article can be manufactured by heating and pressurizing.

  The rigid tool is not particularly limited, and examples thereof include metals such as steel and aluminum; fiber reinforced plastic (FRP); wood; gypsum and the like.

  The flexible film is not particularly limited, and examples thereof include nylon, fluorocarbon resin, and silicone resin.

  The heating temperature is not particularly limited, but is preferably 50 to 250 ° C., and more preferably 80 to 220 ° C. A heating temperature of 50 ° C. or higher is preferable because a suitable curing rate can be obtained. On the other hand, a heating temperature of 250 ° C. or less is preferable because generation of warpage due to thermal distortion can be prevented or suppressed. The heating may be performed sequentially. Specifically, after pre-curing at 50 to 100 ° C. to obtain a tack-free cured product, a method of heating at 120 to 200 ° C., and the like can be mentioned.

The pressure varies depending on the thickness of the prepreg and the volume content of reinforcing fibers, but is preferably ¹ to 10 kgf / cm ² . It is preferable that the pressure is 1 kgf / cm ² or more because the generation or prevention of local uncured parts can be prevented or the occurrence of warpage can be prevented or the like, while the pressure is 10 kgf / cm ² or less. It is preferable from the prevention or suppression of generation of the non-impregnated part and the prevention or suppression of resin leakage.

  The fiber reinforced molded article may be manufactured by other methods. As the other method, for example, a fiber aggregate is placed in a mold and a hand lay-up method, a spray-up method, or a male type or a female type in which the above varnishes are laminated are used. The base material is stacked and impregnated while impregnating the varnish and molded, covered with a flexible mold that can apply pressure to the molded product, vacuum-sealed the one that has been hermetically sealed, and containing reinforcing fibers in advance A prepreg is prepared by impregnating the above-mentioned varnish with the above-mentioned varnish by the SMC press method of compression molding a sheet of varnish into a sheet with a mold, the RTM method of injecting the above varnish into a laminated mold in which fibers are spread, And the like, and the like.

  Hereinafter, the present invention will be described using examples, but the present invention is not limited to the description of the examples. In addition, although the display of "part" is used in an Example, unless otherwise indicated, it represents a "mass part."

Example 1
<Production of epoxy resin>
160 parts (1.0 mol) of 1,6-dihydroxynaphthalene, 925 parts (10.0 mol) of epichlorohydrin, and 139 parts of n-butanol in a flask equipped with a nitrogen introducing pipe, a cooling pipe, a thermometer and a stirrer And 2 parts of tetraethylbenzylammonium chloride were charged and dissolved.

  The temperature of the resulting solution was raised to 65 ° C., and the pressure was reduced to an azeotropic pressure, and 90 parts (1.1 mol) of a 49% aqueous sodium hydroxide solution was added dropwise over 5 hours. After the dropwise addition, the azeotropic distillation was separated by a Dean-Stark apparatus, the aqueous layer was removed, and the reaction was carried out for 30 minutes while returning only the oil layer to the reaction system.

  Unreacted epichlorohydrin was distilled by distillation under reduced pressure, and the obtained crude product was dissolved by adding 59 parts of methyl ethyl ketone and 177 parts of n-butanol. Next, 10 parts of a 10% aqueous sodium hydroxide solution was added, the temperature was raised to 80 ° C., and the reaction was performed for 2 hours.

  The reaction product obtained was washed with 150 parts of water. This was repeated three times, and it was confirmed that the pH of the cleaning solution became neutral. Dehydration was carried out by azeotropic distillation, and after precision filtration, the solvent was distilled off under reduced pressure to obtain 263.8 parts of an epoxy resin.

  The contents of the trifunctional epoxy compound represented by the chemical formula (1) and the trifunctional epoxy compound represented by the chemical formula (2) contained in the obtained epoxy resin are respectively measured by high performance liquid chromatography (HPLC) did. In addition, regarding the conditions of HPLC, a measuring apparatus is "Prominece" (made by Shimadzu Corp.), a column is "ODS-100V" (made by Tosoh Corp.), and a detector is UV254 nm. The measurement conditions are that the column temperature is 40 ° C., and the solvent is a mixed solution of water and acetonitrile and acetonitrile (held in a mixed solvent of water: acetonitrile = 70: 30 (volume ratio) for 2.5 minutes, and then The developing solvent of the column is maintained as water: acetonitrile = 0: 100 over 15 minutes using acetonitrile), and the flux is 0.3 mL / min. And, the standard substance is polystyrene. In addition, as a sample, what filtered the acetonitrile solution of 0.5 mass% (solid content conversion) with a 100 micrometers micro filter is used. As a result, the content of the trifunctional epoxy compound represented by the chemical formula (1) in the epoxy resin is 0.4% by mass, and the content of the trifunctional epoxy compound represented by the chemical formula (2) is 0.4 It was mass%. The content of the trifunctional epoxy compound was 0.8% by mass.

<Production of Epoxy Resin Composition>
With respect to 70 parts of the above-mentioned epoxy resin, 30 parts of 4,4'- diamino diphenyl sulfone which is a hardening agent was melt mixed on the conditions of 100 ° C and 2 hours, and the epoxy resin composition was obtained.

<Manufacture of cured product>
The epoxy resin composition prepared above was poured between glass plates sandwiching a 2 mm spacer, and cured at 150 ° C. for 1 hour and then at 180 ° C. for 3 hours to produce a cured product.

Example 2
<Production of epoxy resin>
An epoxy resin was produced in the same manner as in Example 1 except that 555 parts (6.0 mol) of epichlorohydrin was used.

  With respect to the obtained epoxy resin, the content of the trifunctional epoxy compound represented by the chemical formula (1), the content of the trifunctional epoxy compound represented by the chemical formula (2), and 3 in the same manner as in Example 1 The content of the functional epoxy compound was measured. As a result, the content of the trifunctional epoxy compound represented by the chemical formula (1) is 1.0% by mass, and the content of the trifunctional epoxy compound represented by the chemical formula (2) is 1.3% by mass The content of the trifunctional epoxy compound was 2.3% by mass.

<Production of Epoxy Resin Composition and Cured Product>
In the same manner as in Example 1, an epoxy resin composition and a cured product were produced.

[Example 3]
<Production of epoxy resin>
An epoxy resin was produced in the same manner as in Example 1 except that 370 parts (4.0 mol) of epichlorohydrin was used.

  With respect to the obtained epoxy resin, the content of the trifunctional epoxy compound represented by the chemical formula (1), the content of the trifunctional epoxy compound represented by the chemical formula (2), and 3 in the same manner as in Example 1 The content of the functional epoxy compound was measured. As a result, the content of the trifunctional epoxy compound represented by the chemical formula (1) is 1.9% by mass, and the content of the trifunctional epoxy compound represented by the chemical formula (2) is 2.0% by mass The content of the trifunctional epoxy compound was 3.9% by mass.

<Production of Epoxy Resin Composition and Cured Product>
In the same manner as in Example 1, an epoxy resin composition and a cured product were produced.

Comparative Example 1
<Production of epoxy resin>
An epoxy resin was produced in the same manner as in Example 1 except that 185 parts (2.0 mol) of epichlorohydrin was used.

  With respect to the obtained epoxy resin, the content of the trifunctional epoxy compound represented by the chemical formula (1), the content of the trifunctional epoxy compound represented by the chemical formula (2), and 3 in the same manner as in Example 1 The content of the functional epoxy compound was measured. As a result, the content of the trifunctional epoxy compound represented by the chemical formula (1) is 2.6% by mass, and the content of the trifunctional epoxy compound represented by the chemical formula (2) is 3.2% by mass The content of the trifunctional epoxy compound was 5.8% by mass.

<Production of Epoxy Resin Composition and Cured Product>
In the same manner as in Example 1, an epoxy resin composition and a cured product were produced.

  The epoxy resins produced in Examples 1 to 3 and Comparative Example 1 are shown in Table 1 below.

<Evaluation>
[Evaluation of epoxy resin]
The epoxy equivalent weight, viscosity, and glass transition point (Tg) of the epoxy resins produced in Examples 1 to 3 and Comparative Example 1 were measured.

(Epoxy equivalent)
The epoxy equivalent of the epoxy resin was measured by the method of JIS K 7236: 2009. The obtained results are shown in Table 2 below.

(viscosity)
The viscosity of the epoxy resin at 52 ° C. was measured using a B-type viscometer (manufactured by Eiko Seiki Co., Ltd.). The obtained results are shown in Table 2 below.

[Evaluation of cured product]
The glass transition point, flexural strength, flexural modulus, tensile strength, tensile modulus, and elongation were measured for the cured epoxy products produced in Examples 1 to 3 and Comparative Example 1 (glass transition point (Tg))
Maximum change in elastic modulus of cured product using a visco-elasticity measuring device (DMA: solid visco-elasticity measuring device RSAII manufactured by Rheometrics, rectangular tension method; frequency 1 Hz, heating rate 3 ° C./min, maximum measuring temperature 300 ° C.) The temperature at which the rate of change in tan δ was the largest was measured, and this was evaluated as the glass transition temperature (Tg). The results are shown in Table 2 below.

(Bending strength · bending elastic modulus)
According to JIS K6911: 2006, it measured using Shimadzu Corp. make AUTOGRAPH AG-I, and measured the flexural strength and flexural modulus of elasticity of a hardened material. The obtained results are shown in Table 2 below.

(Tensile strength, tensile modulus, elongation)
According to JIS K7161: 1994, it measured using Shimadzu Corp. make AUTOGRAPH AG-I, and measured the tensile strength of the hardened | cured material, the tensile elasticity modulus, and elongation. The obtained results are shown in Table 2 below.

  As apparent from Table 2 above, the cured products of the epoxy resins obtained in Examples 1 to 3 have high glass transition points (Tg) and are found to be excellent in heat resistance.

  Moreover, it is understood that the cured products obtained in Examples 1 to 3 have high flexural strength, flexural modulus, tensile strength, tensile modulus, and elongation, and are excellent in toughness.

Claims (4)

An epoxy resin which is a reaction product of 1,6-dihydroxynaphthalene and epihalohydrin,
The epoxy resin has the following chemical formula (1) and / or chemical formula (2):

Containing a trifunctional epoxy compound represented by
The epoxy resin whose content of the said trifunctional epoxy compound is 5.0 mass% or less with respect to the solid content of an epoxy resin.   The epoxy resin according to claim 1 whose content of said trifunctional epoxy compound is 3.0 mass% or less to solid content of an epoxy resin.   An epoxy resin composition comprising the epoxy resin according to claim 1 and a curing agent.   A cured product obtained by curing the epoxy resin composition according to claim 3.