WO2018139112A1

WO2018139112A1 - Epoxy resin, epoxy resin composition containing same, and cured object obtained from said epoxy resin composition

Info

Publication number: WO2018139112A1
Application number: PCT/JP2017/045470
Authority: WO
Inventors: 森永　邦裕; 真実木村; 弘司林; 菜々杉本
Original assignee: Dic株式会社
Priority date: 2017-01-24
Filing date: 2017-12-19
Publication date: 2018-08-02
Also published as: JPWO2018139112A1

Abstract

A purpose of the present invention is to provide an epoxy resin giving cured objects which are excellent in terms of heat resistance and toughness. Specifically, the epoxy resin is a product of the reaction of 1,6-dihydroxynaphthalene with an epihalohydrin, and includes the trifunctional epoxy compound(s) represented by chemical formula (1) and/or chemical formula (2), the content of the trifunctional epoxy compound(s) being 5.0 mass% or less with respect to the solid matter of the epoxy resin.

Description

Epoxy resin, epoxy resin composition containing the same, and cured product using the epoxy resin composition

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

The epoxy resin is a curable resin that contains an epoxy group in the molecule and can be cured by forming a crosslinked network with the epoxy group. Epoxy resin cured products have excellent mechanical strength, heat resistance, water resistance, insulation, etc., so they can be used for applications such as fiber-reinforced composite materials, heat dissipation members, adhesives, paints, semiconductors, and printed wiring boards. 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 is expanding, for example, features such as excellent heat resistance and mechanical strength while being lightweight. . In connection with this, the required characteristic of the hardened | cured material of an epoxy resin is improving, and the higher performance of an epoxy resin is calculated | required.

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

In addition, it is described that the epoxy resin described in Patent Document 1 can be obtained by reacting dihydroxynaphthalene and epihalohydrin and epoxidizing them.

JP 2013-60607 A

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

Therefore, 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.

The present inventors have conducted intensive research to solve the above problems. As a result, it has been found that the above-mentioned problems can be solved by controlling the content of a predetermined component of a composition obtained by using a predetermined dihydroxynaphthalene and reacting with epihalohydrin, thereby completing the present invention. It was.

That is, the present invention relates to an epoxy resin that is a reaction product of 1,6-dihydroxynaphthalene and epihalohydrin. At this time, the epoxy resin includes 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 based on the solid content of the epoxy resin. It is 5.0 mass% or less, It is characterized by the above-mentioned.

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

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

<Epoxy resin>
The epoxy resin according to this embodiment is a reaction product of 1,6-dihydroxynaphthalene and epihalohydrin.

When 1,6-dihydroxynaphthalene and epihalohydrin are reacted, glycidyl etherification reaction generally proceeds at the 1-position 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 as a reaction product and the cured product thereof can be obtained only with a bifunctional epoxy compound that can be a main component such as 1,6-bis (2,3-epoxypropan-1-yloxy) naphthalene. And may be affected by other epoxy compounds.

The epoxy resin according to the present embodiment pays attention to a predetermined trifunctional epoxy compound that can be included in the reaction product, and controls the content of the trifunctional epoxy compound. Thereby, the obtained hardened | cured material is excellent in heat resistance and toughness.

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

[Epihalohydrin]
Although it does not restrict | limit especially as an epihalohydrin, Epichlorohydrin, epibromohydrin, epiiodohydrin etc. are mentioned. These epihalohydrins may be used alone or in combination of two or more.

The amount of epihalohydrin added is not particularly limited, but is preferably 1.5 to 10.0 moles and preferably 2.0 to 7.5 moles with respect to 1 mole of the hydroxy group of 1,6-dihydroxynaphthalene. It is more preferable. It is preferable that the addition amount of epihalohydrin is 1.5 mol or more because a low-viscosity epoxy resin with less oligomer components can be obtained. On the other hand, when the added amount of epihalohydrin is 10.0 mol or less, the amount of excess epihahydrin that becomes unnecessary after the reaction can be reduced, which is preferable.

[reaction]
The reaction between 1,6-dihydroxynaphthalene and epihalohydrin is not particularly limited and can be performed by a known method. In one embodiment, the reaction includes a step (1) of reacting a mixture containing 1,6-dihydroxynaphthalene and epihalohydrin in the presence of a basic compound. Under the present circumstances, the process (2) with which the obtained reaction material is made to react in presence of a basic compound may be further included as needed.

(Process (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 contains 1,6-dihydroxynaphthalene and epihalohydrin. In addition, a solvent, a basic compound, etc. may be further included as needed.

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; dimethyl sulfoxide and the like. 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 further preferably 5 to 50% by mass with respect to the addition amount of epihalohydrin. It is particularly preferably 10 to 30% by mass.

Basic Compound The basic compound has a function of promoting the nucleophilic reaction and ring-closing reaction between 1,6-dihydroxynaphthalene and epihalohydrin.

The basic compound is not particularly limited, and examples thereof include potassium hydroxide, sodium hydroxide, barium hydroxide, magnesium oxide, sodium carbonate, and potassium carbonate. Of these, potassium hydroxide and sodium hydroxide are preferably used. In addition, these basic compounds may be used independently or may be used in combination of 2 or more type.

Reaction Typically, the reaction includes a first reaction (nucleophilic reaction) of 1,6-dihydroxynaphthalene and epihalohydrin and a second reaction (ring closure) of the resulting haloalcohol as shown below. Reaction).

The first reaction and the second reaction may 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 remove the epihalohydrin after the first reaction as the main reaction and to perform the second reaction as the main reaction.

The amount of the basic compound added in the first reaction is not particularly limited, but is preferably 0.05 to 0.7 mol with respect to 1 mol of 1,6-dihydroxynaphthalene. More preferably, it is ˜0.5 mol.

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

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

The amount of the basic compound added in 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. More preferably, it is 6 to 2.0 mol.

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

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

(Process (2))
Step (2) is a step of reacting the reaction product obtained in step (1) in the presence of a basic compound. The reaction product obtained in the step (1) does not proceed with the second reaction described above, and an unreacted haloalcohol obtained by the first reaction may remain. By performing the step (2), such an unreacted haloalcohol can be closed and the unreacted haloalcohol in the epoxy resin can be eliminated or reduced.

In step (2), the amount of basic compound added, the reaction temperature, and the reaction time are the same as in the second reaction described above.

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

[Reaction product]
The reaction product includes an epoxy compound. In addition, the reaction product may include a solvent and other compounds.

The epoxy compound mainly includes a bifunctional epoxy compound. In addition, a monofunctional epoxy compound, a trifunctional epoxy compound, a polyfunctional epoxy compound, an oligomer of an epoxy compound, and the like may be included.

(Bifunctional epoxy compound)
The bifunctional epoxy compound is a compound in which two glycidyl ether groups are introduced into 1,6-dihydroxynaphthalene. Specific examples thereof include, but are not limited to, compounds represented by the following chemical formula (3).

(Monofunctional epoxy compound)
The monofunctional epoxy compound is a compound in which one glycidyl ether group is introduced into 1,6-dihydroxynaphthalene. Specific examples thereof include, but are not limited to, compounds represented by the following formulas.

(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 limited to, compounds represented by chemical formulas (1) and (2).

(Polyfunctional epoxy compound)
The polyfunctional epoxy compound is a compound in which four or more glycidyl ether groups are introduced into 1,6-dihydroxynaphthalene. Specific examples thereof include, but are not limited to, compounds represented by the following formulas.

(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 obtained by reacting a bifunctional epoxy compound represented by the above 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 examples thereof include water, a solvent, and the like that can be intentionally added in the purification step, in addition to the solvent used in the above-described reaction.

(Other compounds)
The other compound is not particularly limited, and examples thereof include compounds other than the epoxy compound generated by the reaction of 1,6-dihydroxynaphthalene and epihalohydrin. Specific examples include unreacted 1,6-dihydroxynaphthalene, unreacted epihalohydrin, unreacted basic compounds, and compounds derived from these (byproducts, etc.).

In addition, since the reaction conditions are usually controlled and purified, the content of other compounds tends to be low.

[Configuration of epoxy resin]
The epoxy resin according to this embodiment is the above-described reaction product. At this time, the epoxy resin contains a trifunctional epoxy compound represented by the chemical formula (1) and / or (2).

The content of the trifunctional epoxy compound is 5.0% by mass or less, preferably 3.0% by mass or less, more preferably 0.01 to 3.0% by mass, based on the solid content of the epoxy resin. %, And more preferably 0.03 to 2.0% by mass. Under the present circumstances, when an epoxy resin contains both the trifunctional epoxy compound represented by Chemical formula (1) and the trifunctional epoxy compound represented by Chemical formula (2), the total value of these content is the said content. Just fill it. In the present specification, the “solid content of the epoxy resin” means the total mass of the 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 matches the solid content.

The trifunctional epoxy compound has three functional groups. When the epoxy resin contains such a trifunctional epoxy compound, the resulting cured product can have high heat resistance and high strength. Moreover, the fall of elongation can be suppressed or prevented because content of a trifunctional epoxy resin shall be 5.0 mass% or less, and high toughness can be obtained as a result.

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. It is preferable that the content of the bifunctional epoxy compound is 30% by mass or more because the viscosity can be reduced. On the other hand, it is preferable that the content of the bifunctional epoxy compound is 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 that the content of the monofunctional epoxy compound is 2% by mass or more because the viscosity can be lowered. On the other hand, when the content of the monofunctional epoxy compound is 15% by mass or less, heat resistance can be increased, which is preferable.

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 that the content of the polyfunctional epoxy compound is 2% by mass or more because heat resistance can be increased. On the other hand, when the content of the polyfunctional epoxy compound is 10% by mass or less, the viscosity can be lowered, which is preferable.

The content of the oligomer in the epoxy resin is preferably 4 to 40% by mass, and more preferably 5 to 30% by mass with respect to the total mass of the epoxy compound. It is preferable that the oligomer content is 4% by mass or more because of excellent toughness. On the other hand, when the oligomer content is 40% by mass or less, the viscosity can be lowered, which is preferable.

The other compound in the epoxy resin is preferably 5% by mass or less, and more preferably 0.05 to 5% by mass.

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

Adjustment of the content of the component in the epoxy resin may be performed by controlling the reaction and controlling the purification process, or may be performed by adding a separate component. At this time, from the viewpoint of efficiently preparing the epoxy resin, it is preferable to adjust the content of the component of the epoxy resin by controlling the reaction. For example, by appropriately changing the addition amount of epihalohydrin, reaction temperature, reaction time, distillation of epihalohydrin, and the like, the content of the epoxy resin component can be adjusted by controlling the reaction.

The epoxy equivalent of the epoxy resin is not particularly limited, but is preferably 130 to 220 g / equivalent (Eq.), And 135 to 200 g / Eq. It is more preferable that Epoxy equivalent is 130 g / Eq. The above is preferable because the viscosity can be lowered. On the other hand, the epoxy equivalent was 220 g / Eq. The following is preferable because heat resistance can be increased. In addition, the value measured by the method described in an Example shall be employ | adopted for the value of "epoxy equivalent" 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 for the viscosity of the epoxy resin to be 500 mPa · s or more because sagging during molding can be suppressed. On the other hand, when the viscosity of the epoxy resin is 1700 mPa · s or less, it is preferable because the impregnation property to the reinforcing fiber is excellent. In addition, the value measured by the method described in an Example shall be employ | adopted for the value of "viscosity of an epoxy resin" in this specification.

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

[Epoxy resin]
Since the epoxy resin described above can be used, the description thereof is omitted here.

The content of the epoxy resin is preferably 30 to 99% by mass and more preferably 40 to 97% by mass with respect to the solid content of the resin composition. It is preferable that the content of the epoxy resin is 30% by mass or more because the performance of the epoxy resin is easily developed. On the other hand, when the content of the epoxy resin is 99% by mass or less, the choice of the curing agent is preferable. In the present specification, the “solid content of the resin composition” means the total mass of components in the composition excluding the organic solvent described later. Therefore, when the resin composition does not contain a solvent, the total mass of the composition matches the solid content.

[Other epoxy resins]
Another epoxy resin is an epoxy resin containing an epoxy compound other than the epoxy compound contained in the above-described 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 a reaction product 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 hydrogen atom bonded to naphthalene of dihydroxynaphthalene is substituted with a substituent. In this case, the “substituent” means methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, decyl, etc. An alkyl group having 1 to 10 carbon atoms; a cycloalkyl group having 3 to 10 carbon atoms such as cyclopropyl group, cyclobutyl group, methylcyclobutyl group, cyclopentyl group, cyclohexyl group, cyclodecyl group; vinyl group, allyl group, butenyl An alkenyl group having 2 to 10 carbon atoms such as a propylene group or an octenyl group; an alkynyl group having 2 to 10 carbon atoms such as a propargyl group or a butynyl group; 1 to 10 carbon atoms such as a methoxy group, an ethoxy group or a propyloxy group An alkyloxy group having 2 to 10 carbon atoms such as an acetyl group or an ethylcarbonyl group; Aryl groups having 6 to 10 carbon atoms such as nyl group, tolyl group, xylyl group and chlorophenyl group; aralkyl groups having 7 to 10 carbon atoms such as benzyl group; fluorine atom, chlorine atom, bromine atom and iodine atom A halogen atom etc. are mentioned. These substituents may be used alone or in combination of two or more.

The “substituted epihalohydrin” is not particularly limited, but means that at least one of the hydrogen atoms constituting the epihalohydrin is substituted with a substituent, 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, Examples include 3-chloro-2-propyl-1,2-epoxypropane and 3-chloro-3-propyl-1,2-epoxypropane.

Further, the other epoxy resin may be an epoxy resin other than an epoxy resin containing a dihydroxynaphthalene skeleton. Such epoxy resins are not particularly limited, but are bisphenol type epoxy resins such as bisphenol A type epoxy resin and bisphenol F type epoxy resin; biphenyl type epoxy resins such as biphenyl type epoxy resin and tetramethylbiphenyl type epoxy resin; phenol Novolac epoxy resins, cresol novolac epoxy resins, bisphenol A novolac epoxy resins, epoxidized products of condensation products of phenols and aromatic aldehydes having phenolic hydroxyl groups, novolac epoxy resins such as biphenyl novolac epoxy resins; 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 resins]
The other resin means a resin other than the epoxy resin. The other resin may be a thermosetting resin or a thermoplastic resin. Specific examples of other resins include, but are not limited to, polycarbonate resin, polyphenylene ether resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene resin, polypropylene resin, polyimide resin, polyamideimide resin, polyetherimide resin, polyether. Examples include sulfone resins, polyketone resins, polyetherketone resins, polyetheretherketone resins, and phenolic resins. These other resins may be used alone or in combination of two or more.

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

Examples of the amine compound include ethylenediamine, diaminopropane, diaminobutane, diethylenetriamine, triethylenetetramine, 1,4-cyclohexanediamine, isophoronediamine, diaminodicyclohexylmethane, diaminodiphenylmethane, diaminodiphenylsulfone, phenylenediamine, imidazole, and BF. Examples thereof include ₃ -amine complexes and guanidine derivatives.

Examples of the amide compounds include polyamide resins synthesized from dicyandiamide and a dimer of linolenic acid and ethylenediamine.

Examples of the acid anhydride compounds include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methyl nadic anhydride, hexahydrophthalic anhydride, methylhexa And hydrophthalic anhydride.

Examples of the phenolic compound include phenol novolak resin, cresol novolak resin, aromatic hydrocarbon formaldehyde resin-modified phenol resin, dicyclopentadiene phenol addition resin, phenol aralkyl resin, α-naphthol aralkyl resin, β-naphthol aralkyl resin, biphenyl. Aralkyl resins, trimethylol methane resins, tetraphenylol ethane resins, naphthol novolak resins, naphthol-phenol co-condensed novolac resins, naphthol-cresol co-condensed novolac resins, and amino group-containing triazine compounds (melamine, benzoguanamine, etc.) and phenols ( Phenol, cresol, and the like) and formaldehyde, and aminotriazine-modified phenolic resin.

Of these, amine compounds and phenol compounds are preferably used. Diaminodiphenyl sulfone, phenol novolac resin, cresol novolac resin, phenol aralkyl resin, α-naphthol aralkyl resin, β-naphthol aralkyl resin, biphenyl aralkyl resin, amino It is more preferable to use a triazine-modified phenol resin.

In addition, the above-mentioned hardened | cured material may be used independently or may be used in combination of 2 or more type.

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. When the content of the curing agent is 1% by mass or more, it is preferable because choices of the curing agent are expanded. On the other hand, it is preferable that the content of the curing agent is 70% by mass or less because the performance of the epoxy resin is easily developed.

[Curing accelerator]
The curing accelerator has a function of promoting curing. Thereby, reaction time can be shortened, generation of unreacted epoxy compounds can be prevented or reduced, and the like.

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. Of 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 from 0.1 to 10% by mass, more preferably from 0.5 to 5% by mass, based on the solid content of the resin composition. It is preferable that the content of the curing accelerator is 0.1% by mass or more because curing can be accelerated. On the other hand, when the content of the curing accelerator is 10% by mass or less, it is preferable because the pot life can be lengthened.

[Organic solvent]
The organic solvent has a function of adjusting the viscosity of the epoxy resin composition. Thereby, the impregnation property 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 Is mentioned. Of these, alcohols and ketones are preferably used, and butanol and methyl ethyl ketone are more preferably used. In addition, these solvents may be used independently or may be used in combination of 2 or more type.

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 that the content of the organic solvent is 10% by mass or more because the viscosity can be lowered. On the other hand, it is preferable that the content of the organic solvent is 60% by mass or less because nonvolatile components can be reduced.

[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 silica such as fused silica and crystalline silica, aluminum oxide, silicon nitride, and aluminum nitride. Of these, silica is preferably used, and fused silica is more preferably used. In addition, these inorganic fillers may be used independently or may be used in combination of 2 or more type.

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 that the content of the inorganic filler is 20% by mass or more because the elastic modulus can be increased. On the other hand, when the content of the inorganic filler is 80% by mass or less, it is preferable because the viscosity can be lowered.

[Additive]
Additives that can be contained in the epoxy resin composition are not particularly limited, but include reinforcing fibers, flame retardants, release agents, pigments, antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, and conductivity-imparting agents. Etc. These additives may be used alone or in combination of two or more.

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

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

The raw material of the reinforcing fiber is not particularly limited, but includes carbon fibers such as polyacrylonitrile-based carbon fiber, pitch-based carbon fiber, rayon-based carbon fiber, glass fiber, aramid fiber, boron fiber, alumina fiber, silicon carbide fiber, etc. It is done. Of these, it is preferable to use carbon fibers.

Examples of the form of the reinforcing fiber include twisted yarn, untwisted yarn, and non-twisted yarn. Of these, untwisted yarns and non-twisted yarns are preferred because they have excellent moldability. The form of the reinforcing fiber may be one in which the fiber directions are 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 the reinforcing fiber 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. When the content of the reinforcing fiber is 40% by volume or more, flame retardancy of the obtained cured product is obtained, and this is preferable from the viewpoint of excellent physical properties such as specific elastic modulus and specific strength. On the other hand, when the content of the reinforcing fibers is 85% by volume or less, the adhesiveness between the epoxy resin composition and the reinforcing fibers becomes good, and for example, when the prepregs are laminated, delamination of the prepregs can be prevented.

The impregnation degree of the reinforcing fiber of the epoxy resin composition in the fiber reinforced composite material is not particularly limited, 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 a known method can be adopted as appropriate. Specific examples include a wet method and a hot melt method.

In the wet method, a varnish in which each component contained in the epoxy resin composition is uniformly mixed is prepared, 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 obtain a fiber. This is a method for obtaining a reinforced composite material.

In the hot melt method, the viscosity of the epoxy resin composition is reduced 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. This is a method of impregnating a film by heating and pressurizing it.

In this case, in the hot melt method, the temperature of the resin composition when impregnating the reinforcing fibers is preferably 50 to 250 ° C., and more preferably 50 to 100 ° C. It is preferable that the temperature of the resin composition at the time of impregnation is 50 ° C. or higher because the reinforcing fibers are easily impregnated. On the other hand, it is preferable that the temperature of the resin composition at the time of impregnation is 250 ° C. or lower because an increase in the glass transition temperature due to the progress of a partial curing reaction can be suppressed and appropriate drape can be maintained.

Of the above, it is preferable to use a hot melt method in which no residual organic solvent is generated.

<Hardened product>
According to one form of this invention, hardened | cured material is provided. The cured product is formed by curing the above-described 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., more preferably 200 to 250 ° C. A glass transition point (Tg) of 200 ° C. or higher is preferable because heat resistance can be increased. On the other hand, a glass transition point (Tg) of 270 ° C. or less is preferable because of excellent toughness. In addition, the value measured by the method described in an Example shall be employ | adopted for the value of "glass transition point (Tg)" in this specification.

The curing temperature of the epoxy resin composition is preferably 50 to 250 ° C, and more preferably 70 to 200 ° C. It is preferable for the curing temperature to be 50 ° C. or higher because the curing reaction can be carried out quickly. On the other hand, if the curing temperature is 250 ° C. or lower, it is preferable because the amount of energy required for curing can be suppressed.

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

The fiber reinforced resin molded product is obtained by curing the above-mentioned fiber reinforced composite material.

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

The manufacturing method of the fiber reinforced resin molded product is not particularly limited, but after the fiber reinforced composite material is cut into a predetermined size, the epoxy resin composition is cured while applying heat and pressure to a laminate in which a predetermined number of layers are laminated. Is mentioned.

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

As a manufacturing method, for example, when manufacturing a plate-like fiber reinforced resin molded product, first, after cutting a sheet-like fiber reinforced composite material into a predetermined dimension, a predetermined number of sheets are placed on a rigid tool in a predetermined fiber axis direction. Laminate and seal with flexible film. Next, the space between the rigid tool and the flexible film is sucked with a vacuum pump to be deaerated. And after installing in an autoclave, a fiber reinforced resin molded product 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; plaster and the like.

Further, the flexible film is not particularly limited, and examples thereof include nylon, fluororesin, and silicone resin.

The heating temperature is not particularly limited, but is preferably 50 to 250 ° C, 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, it is preferable that the heating temperature is 250 ° C. or lower because warpage due to thermal strain can be prevented or suppressed. Heating may be performed sequentially. Specifically, a method of pre-curing at 50 to 100 ° C. to form a tack-free cured product and then heating at 120 to 200 ° C. can be used.

The pressure varies depending on the thickness of the prepreg and the volume content of the reinforcing fibers, but is preferably 1 to 10 kgf / cm ² . When the pressure is 1 kgf / cm ² or more, prevent or suppress the occurrence of localized uncured portions, preferred because it is prevented or suppressed, such as warping of the generator, whereas, when the pressure is 10 kgf / cm ² or less, It is preferable because it is possible to prevent or suppress the occurrence of unimpregnated portions and to prevent or suppress leakage of the resin.

Note that the fiber-reinforced molded product may be manufactured by other methods. As the other method, for example, a fiber aggregate is laid on a mold, and the hand lay-up method or spray-up method in which the varnish is stacked in multiple layers is used. Vacuum bag method in which the base material is stacked while impregnated with varnish, molded, covered with a flexible mold that can apply pressure to the molded product, and hermetically sealed is vacuum (reduced pressure) molding, contains reinforcing fibers in advance A prepreg in which a reinforced varnish is impregnated with the varnish is manufactured by an SMC press method in which a sheet of varnish is compression-molded with a mold, an RTM method in which the varnish is injected into a mating mold in which fibers are spread, And a method of baking and hardening in a large autoclave.

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, "mass part" is represented.

[Example 1]
<Manufacture of epoxy resin>
In a flask equipped with a nitrogen inlet tube, a condenser tube, a thermometer, and a stirrer, 160 parts (1.0 mol) of 1,6-dihydroxynaphthalene, 925 parts (10.0 mol) of epichlorohydrin, 139 parts of n-butanol , And 2 parts of tetraethylbenzylammonium chloride were charged and dissolved.

The resulting solution was heated to 65 ° C. and then decompressed to an azeotropic pressure, and 90 parts (1.1 mol) of a 49% aqueous sodium hydroxide solution was added dropwise over 5 hours. After dropping, the azeotropic distillate 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 59 parts of methyl ethyl ketone and 177 parts of n-butanol were added to and dissolved in the obtained crude product. Next, 10 parts of a 10% aqueous sodium hydroxide solution was added, the temperature was raised to 80 ° C., and the reaction was carried out for 2 hours.

The obtained reaction product was washed with 150 parts of water. This was repeated 3 times, and it was confirmed that the pH of the cleaning liquid became neutral. An azeotropic dehydration operation was performed, and after fine filtration, the solvent was distilled off under reduced pressure to obtain 263.8 parts of an epoxy resin.

The content 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 is measured by high performance liquid chromatography (HPLC). did. Regarding the HPLC conditions, the measuring apparatus is “Prominece” (manufactured by Shimadzu Corporation), the column is “ODS-100V” (manufactured by Tosoh Corporation), and the detector is UV254 nm. The measurement conditions were that the column temperature was 40 ° C., the solvent was a mixed solution of water and acetonitrile and acetonitrile (water: acetonitrile = 70: 30 (volume ratio) mixed solvent was maintained for 2.5 minutes, The column developing solvent is maintained as water: acetonitrile = 0: 100 using acetonitrile for 15 minutes), and the flux is 0.3 mL / min. The standard material is polystyrene. In addition, as a sample, what filtered 0.5 mass% (solid content conversion) acetonitrile solution with a 100 micrometer 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.

<Manufacture of epoxy resin composition>
To 70 parts of the epoxy resin described above, 30 parts of 4,4′-diaminodiphenylsulfone as a curing agent was melt-mixed at 100 ° C. for 2 hours to obtain an epoxy resin composition.

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

[Example 2]
<Manufacture 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.

About the obtained epoxy resin, by the method similar to Example 1, content of the trifunctional epoxy compound represented by Chemical formula (1), content of the trifunctional epoxy compound represented by Chemical formula (2), and 3 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.

<Manufacture 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]
<Manufacture 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.

About the obtained epoxy resin, by the method similar to Example 1, content of the trifunctional epoxy compound represented by Chemical formula (1), content of the trifunctional epoxy compound represented by Chemical formula (2), and 3 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.

[Comparative Example 1]
<Manufacture 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.

About the obtained epoxy resin, by the method similar to Example 1, content of the trifunctional epoxy compound represented by Chemical formula (1), content of the trifunctional epoxy compound represented by Chemical formula (2), and 3 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.

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 resin produced in Examples 1 to 3 and Comparative Example 1 was measured for epoxy equivalent, viscosity, and glass transition point (Tg).

(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]
With respect to the epoxy cured products produced in Examples 1 to 3 and Comparative Example 1, the glass transition point, bending strength, bending elastic modulus, tensile strength, tensile elastic modulus, and elongation were measured (glass transition point (Tg)).
Using a viscoelasticity measuring device (DMA: solid viscoelasticity measuring device RSAII manufactured by Rheometric, rectangular tension method; frequency 1 Hz, temperature rising rate 3 ° C./min, maximum measuring temperature 300 ° C.) (The tan δ change rate is the highest) was measured, and this was evaluated as the glass transition temperature (Tg). The results are shown in Table 2 below.

(Bending strength / flexural modulus)
According to JIS K6911: 2006, it measured using AUTOGRAPH AG-I made by Shimadzu Corporation, and the bending strength and bending elastic modulus of the cured product were measured. The obtained results are shown in Table 2 below.

(Tensile strength, tensile modulus, elongation)
In accordance with JIS K7161: 1994, measurement was performed using AUTOGRAPH AG-I manufactured by Shimadzu Corporation, and the tensile strength, tensile elastic modulus, and elongation of the cured product were measured. The obtained results are shown in Table 2 below.

As apparent from Table 2 above, it can be seen that the cured epoxy resins obtained in Examples 1 to 3 have a high glass transition point (Tg) and excellent heat resistance.

It can also be seen that the cured products obtained in Examples 1 to 3 have high bending strength, flexural modulus, tensile strength, tensile modulus, and elongation, and are excellent in toughness.

Claims

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

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 solid content of an epoxy resin.
The epoxy resin according to claim 1, wherein the content of the trifunctional epoxy compound is 3.0% by mass or less based on the solid content of the epoxy resin.
An epoxy resin composition comprising the epoxy resin according to claim 1 or 2 and a curing agent.
Hardened | cured material formed by hardening | curing the epoxy resin composition of Claim 3.