JP6962014B2 - Oligophenol mixture, resin and cured product - Google Patents

Description

The present invention relates to a mixture of novel oligophenol compounds. More specifically, the present invention relates to an oligophenol mixture which gives excellent elasticity at high temperature when made into a resin and is particularly suitable as an electric / electronic material, a resin obtained by using this oligophenol mixture, and a cured product thereof.

Oligophenol compounds are generally made into resins with excellent mechanical and electrical properties by polymerizing them by various methods to obtain polymers. Therefore, adhesives, paints, civil engineering and construction materials, electricity and It is used in various fields such as electronic materials. In particular, an epoxy resin cured product obtained by curing and polymerizing an oligophenol compound as a curing agent for an epoxy compound has an excellent balance of insulating properties, water absorption resistance, adhesiveness, etc., and is an insulating material, a laminated material, and a sealing material. It is used in a wide range of fields, including for electrical and electronic materials such as.

In recent years, especially for electrical and electronic materials such as multi-layer circuit boards, equipment has become smaller, lighter, and more sophisticated, and further multi-layer, high-density, thin, and reliable improvements have been made. It has been demanded. In such applications, cracks and warpage of the substrate due to stress generation due to shrinkage of the resin during curing polymerization may become a problem, and the residual stress during curing polymerization is relaxed to affect the substrate. There is a widespread demand for materials that can be made smaller.

Examples of oligophenol compounds generally used as a curing agent for epoxy compounds include compounds obtained by polymerizing various phenol compounds and formaldehyde. For example, Non-Patent Document 1 discloses an example in which phenol novolac, which is obtained by polycondensing phenol and formaldehyde, is used as a curing agent for an epoxy compound.

Review Epoxy Resin Volume 1 (published by Epoxy Resin Technology Association), First Edition, page 182

However, as a result of diligent studies by the present inventor, the method of Non-Patent Document 1 has a high elastic modulus of the cured resin at a particularly high temperature, and there is a risk that cracks or warpage may occur in the substrate due to residual stress during curing polymerization. There was found.

In view of the above problems, it is an object of the present invention to provide an oligophenol mixture that does not cause problems due to residual stress during curing polymerization when it is made into a resin.

As a result of repeated diligent studies, the present inventor has found that a specific oligophenol mixture can solve a problem caused by residual stress due to curing polymerization when it is made into a resin, and has completed the present invention.
That is, the gist of the present invention lies in the following [1] to [7].

[1] A mixture of oligophenol compounds composed of a group of compounds represented by the following formula (1), in which the average value of n calculated from the hydroxyl value is within the range of 0.015 or more and 1.5 or less. An oligophenol mixture characterized by being present.

(In the above formula (1), n represents an integer of 0 or more, R ¹ represents an alkyl group having 6 or more carbon atoms and 13 or less ^{carbon atoms, and R 2} represents a hydrogen atom or an alkyl group or an alkenyl group having 1 to 4 carbon atoms. show.)
[2] The oligophenol mixture according to [1], wherein ^{R 1} is an n-undecylic group and R ^{2 is a hydrogen atom.}
[3] The oligophenol mixture according to [1] or [2], wherein the average value of n calculated from the hydroxyl value is 0.7 or less.
[4] A resin obtained by polymerizing the oligophenol mixture according to any one of [1] to [3].
[5] An epoxy resin composition comprising the oligophenol mixture according to any one of [1] to [3].
[6] An epoxy resin cured product obtained by curing the epoxy resin composition according to [5].

According to the present invention, it is possible to provide an oligophenol mixture capable of solving problems such as warping and cracking of a substrate due to residual stress during curing polymerization when a resin is produced. Further, it is possible to provide a composition containing the oligophenol mixture and a high-quality resin obtained by polymerizing the composition, particularly an epoxy resin composition and an epoxy resin cured product.

The embodiments of the present invention will be described in detail below, but the description of the constituent elements described below is an example of the embodiments of the present invention, and the following description contents do not exceed the gist of the present invention. It is not limited to. In addition, when the expression "~" is used in this specification, it shall be used as an expression including numerical values or physical property values before and after the expression.

[mechanism]
The reason why the resin obtained by using the mixture of the oligophenol compounds of the present invention (hereinafter, sometimes referred to as "oligophenol of the present invention") as a raw material is excellent in stress relaxation during curing and polymerization is considered as follows.
In other words, the oligo phenol compound represented by the formula (1) below, have an alkyl group R ¹ of the long-chain in the side chain, by that part acts as a flexible portion at the time of curing polymerization, in particular It is considered that the elastic modulus at high temperature could be greatly reduced. Further, by substituting the long-chain alkyl group R ¹ with a methylene cross-linked site instead of the phenol site, the long-chain alkyl groups R ¹ are sterically close to each other and easily interact with each other at the time of curing polymerization, so that the flexible site can be formed. It is considered that the stress relaxation effect could be enhanced by increasing the size.

[Oligophenol]
<Structure>
The oligophenol of the present invention is a mixture of oligophenol compounds composed of a group of compounds represented by the following formula (1), and the average value of n calculated from the hydroxyl value is 0.015 or more and 1.5 or less. It is characterized in that it is within the range of.

(In the above formula (1), n represents an integer of 0 or more, R ¹ represents an alkyl group having 6 or more carbon atoms and 13 or less ^{carbon atoms, and R 2} represents a hydrogen atom or an alkyl group or an alkenyl group having 1 to 4 carbon atoms. show.)

In the above formula (1), R ¹ represents an alkyl group having 6 to 13 carbon atoms. When the oligophenol ^{of the present invention is used as a resin raw material when the number of carbon atoms of R 1} is equal to or higher than the above lower limit value, the obtained resin is preferable in that it easily exhibits excellent properties such as flexibility, and the above upper limit value is preferable. When the value is less than or equal to the value, when the oligophenol of the present invention is used as a resin raw material, the obtained resin is preferable in that it easily exhibits excellent properties such as mechanical strength and heat resistance. Further, when ^{the carbon number of R 1} is within the above lower limit value and upper limit value, the oligophenol of the present invention easily develops a low melting point property and can be suitably used as a specific color developer. become.

Examples of the alkyl group having 6 to 13 carbon atoms of R ¹ include a linear or branched alkyl group and an alkyl group having a partially cyclic structure. Among them, the raw material is easily available and the present invention is used. A linear or branched alkyl in that the oligophenol is easily available and that when the oligophenol of the present invention is used as a resin raw material, the obtained resin is more likely to exhibit excellent properties such as flexibility. It is preferably a group, more preferably a linear alkyl group.

Specific examples of the linear alkyl group of R ¹ include an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, and an n-dodecyl group. Examples thereof include an n-tridecyl group, and a linear chain having 7 to 12 carbon atoms such as an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group and an n-dodecyl group. A linear alkyl group having 8 to 11 carbon atoms of an n-octyl group, an n-nonyl group, an n-decyl group and an n-undecyl group is more preferable, and an n-undecyl group is particularly preferable.

As a specific example of the branched alkyl group of ^{R 1,}
Methylpentyl group, methylhexyl group, methylheptyl group, methyloctyl group, methylnonyl group, methyldecyl group, methylundecyl group, methyldodecyl group;
Dimethylbutyl group, dimethylpentyl group, dimethylhexyl group, dimethylheptyl group, dimethyloctyl group, dimethylnonyl group, dimethyldecyl group, dimethylundecyl group;
Trimethylhexyl group, trimethylheptyl group, trimethyloctyl group, trimethylnonyl group, trimethyldecyl group;
Ethylbutyl group, ethylpentyl group, ethylhexyl group, ethylheptyl group, ethyloctyl group, ethylnonyl group, ethyldecyl group, ethylundecyl group;
Propylhexyl group, propylheptyl group, propyloctyl group, propylnonyl group, propyldecyl group;
Butylhexyl group, butylheptyl group, butyloctyl group, butylnonyl group;
And so on.

Of these, branched alkyl groups having 6 to 10 carbon atoms such as ethylbutyl group, ethylpentyl group, ethylhexyl group, ethylheptyl group and ethyloctyl group are preferable, ethylpentyl group and ethylhexyl group are more preferable, and ethylpentyl group is preferable. Especially preferable.

In the above example of the branched alkyl group, the branching position is arbitrary.

Specific examples of the alkyl group having a partially cyclic structure of R ^{1 include}
Cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, cyclodecyl group, cycloundecyl group, cyclododecyl group;
Cyclohexylmethyl group, cycloheptylmethyl group, cyclooctylmethyl group, cyclononylmethyl group, cyclodecylmethyl group, cycloundecylmethyl group, cyclododecylmethyl group;
Cyclohexylethyl group, cycloheptylethyl group, cyclooctylethyl group, cyclononylethyl group, cyclodecylethyl group, cycloundecylethyl group;
Cyclohexylpropyl group, cycloheptylpropyl group, cyclooctylpropyl group, cyclononylpropyl group, cyclodecylpropyl group;
Methylcyclohexyl group, methylcycloheptyl group, methylcyclooctyl group, methylcyclononyl group, methylcyclodecyl group, methylcycloundecyl group, methylcyclododecyl group;
Dimethylcyclohexyl group, dimethylcycloheptyl group, dimethylcyclooctyl group, dimethylcyclononyl group, dimethylcyclodecyl group, dimethylcycloundecyl group;
Ethylcyclohexyl group, ethylcycloheptyl group, ethylcyclooctyl group, ethylcyclononyl group, ethylcyclodecyl group, ethylcycloundecyl group;
Propylcyclohexyl group, propylcycloheptyl group, propylcyclooctyl group, propylcyclononyl group, propylcyclodecyl group;
Hexylcyclohexyl group, hexylcycloheptyl group;
Methylcyclohexylmethyl group, Methylcycloheptylmethyl group, Methylcyclooctylmethyl group, Methylcyclononylmethyl group, Methylcyclodecylmethyl group, Methylcycloundecylmethyl group;
Methylcyclohexylethyl group, methylcycloheptylethyl group, methylcyclooctylethyl group, methylcyclononylethyl group, methylcyclodecylethyl group;
Methylcyclohexylpropyl group, methylcycloheptylpropyl group, methylcyclooctylpropyl group, methylcyclononylpropyl group;
Dimethylcyclohexylmethyl group, dimethylcycloheptylmethyl group, dimethylcyclooctylmethyl group, dimethylcyclononylmethyl group, dimethylcyclodecylmethyl group;
Dimethylcyclohexylethyl group, dimethylcycloheptylethyl group, dimethylcyclooctylethyl group, dimethylcyclononylethyl group;
Dimethylcyclohexylpropyl group, dimethylcycloheptylpropyl group, dimethylcyclooctylpropyl group, dimethylcyclononylpropyl group;
And so on.

Of these, a partially cyclic group having 6 to 7 carbon atoms such as a cyclohexyl group, a cycloheptyl group, a cyclohexylmethyl group, a cycloheptylmethyl group, a cyclohexylethyl group, a cycloheptylethyl group, a methylcyclohexylmethyl group, and a methylcycloheptylmethyl group. An alkyl group having a structure is preferable, a group containing a cyclohexyl group is more preferable, and a cyclohexyl group is particularly preferable.

In the above-mentioned alkyl group having a partially cyclic structure, the substitution position of the substituent is arbitrary.

In the formula (1), R ² represents a hydrogen atom or an alkyl group or an alkenyl group having 1 to 4 carbon atoms.
Specific examples of the alkyl group or alkenyl group having 1 to 4 carbon atoms include
Linear alkyl groups of methyl group, ethyl group, n-propyl group, n-butyl group;
Branched alkyl groups of isopropyl group, 1-methylpropyl group, 2-methylpropyl group, t-butyl group;
Linear or branched alkenyl groups such as ethenyl group, 1-propenyl group, allyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, isopropenyl group;
And so on.

Of these, when the oligophenol of the present invention is used as a resin raw material, R ² is a hydrogen atom or a methyl group, an ethyl group, or propyl in that the obtained resin is more likely to exhibit excellent properties such as heat resistance. It is preferably a group having 1 to 3 carbon atoms such as a group, an allyl group and an isopropyl group, and more preferably a linear group such as a hydrogen atom or a methyl group, an ethyl group, a propyl group and an allyl group. It is particularly preferably a hydrogen atom or a methyl group, and most preferably a hydrogen atom.

Substitution positions of the methylene group having ^{R 1 and R 2} with respect to the phenol structure in the above formula (1) are not particularly specified, but the ortho or para position with respect to the phenol structure (that is, the ortho with respect to the hydroxyl group of the benzene ring of the phenol moiety, respectively). Substitution with a position or para position) is preferable in that the oligophenol of the present invention can be easily obtained.

In the above equation (1), n represents an integer of 0 or more. The upper limit is not particularly specified as long as the average value of n in the oligophenol of the present invention is within the range described later, but is 10 or less in that the melt viscosity is lowered and the oligophenol of the present invention can be easily handled. It is preferably 7 or less, more preferably 5 or less, and most preferably 3 or less.

The oligophenol of the present invention is characterized in that the average value of n calculated from the hydroxyl value is in the range of 0.015 or more and 1.5 or less. The average value of n is preferably 0.020 or more, more preferably 0.030 or more, further preferably 0.050 or more, and particularly preferably 0.10 or more. When the average value of n is not more than the above lower limit value, it tends to be easy to obtain excellent properties such as mechanical strength when this oligophenol is polymerized to form a resin. On the other hand, the average value of n is preferably 1.2 or less, more preferably 1.0 or less, further preferably 0.75 or less, and particularly preferably 0.7 or less. It is particularly preferable that it is 0.6 or less. When the average value of n is not more than the above upper limit value, the oligophenol of the present invention tends to have low viscosity when melted, and tends to be excellent in handleability.

The average value of n of the oligophenol of the present invention can be controlled, for example, by adjusting the ratio of phenols / aldehydes used as a raw material in the production of the oligophenol of the present invention described later. That is, by increasing phenols with respect to aldehydes, the average value of n of the obtained oligophenols of the present invention tends to be lowered. Further, in the precipitation step described later, the average value of n as a mixture is adjusted by taking out a part of the oligophenol compound or mixing oligophenol compounds having different average values of n at an arbitrary ratio. be able to.

The average value of n of the oligophenol of the present invention is calculated by the following method.
That is, by determining the hydroxyl value by the method described in JIS K0070: 1992, converting the hydroxyl value into mass grams per molar hydroxyl group in the oligophenol of the present invention, and then solving the following formula (A). The average value of n can be calculated. The molecular weight of each component can be calculated using the average value (5 significant figures) of the atomic weight of each atom shown in the atomic weight table (2015).
n = (2c-a) / (ba-c) Equation (A)
a: Molecular weight of the bisphenol compound represented by the following formula (2) b: Molecular weight of the trisphenol compound represented by the following formula (3) c: The hydroxyl value was converted into a mass gram per molar hydroxyl group in the oligophenol of the present invention. thing

(The above formula (2), (in ^3), R 1, ^{R 2} have the same meanings as ^R 1, ^{R 2} in the formula (1).)

<Moisture content>
The oligophenol of the present invention may contain water. The water content is usually 0.001% by mass or more, preferably 0.01% by mass or more, and particularly preferably 0.1% by mass or more. On the other hand, it is usually 10% by mass or less, preferably 5% by mass or less, and particularly preferably 1.5% by mass or less. When the oligophenol of the present invention is used as a resin raw material, when the water content is at least the above lower limit value, it tends to be handled safely in terms of handling such as suppressing the generation of static electricity, which is preferable. On the other hand, when the water content is equal to or less than the above upper limit, when the oligophenol of the present invention is used as a resin raw material, it tends to be handled safely in terms of handling, such as suppressing foaming and bumping of the resin raw material due to steam generation. It is preferable.

<Solvent content>
The oligophenol of the present invention may contain an organic solvent. The solvent content is usually 25% by mass or less, preferably 20% by mass or less, more preferably 15% by mass or less, further preferably 10% by mass or less, and 5% by mass or less. Is particularly preferable, and particularly preferably 1% by mass or less. When the solvent content is not more than the above upper limit, when the oligophenol of the present invention is used as a resin raw material, it tends to be handled safely in terms of handling, such as suppressing poisoning and ignition risk due to volatilization of the organic solvent, which is preferable. .. Although the lower limit of the solvent content is not particularly specified, it is preferably 0.0001% by mass or more, more preferably 0.0005% by mass or more, in terms of making the oligophenol of the present invention easily available. preferable.

<Example>
Below, the structure of the oligophenol compound represented by the formula (1) is illustrated by the combination of ^{R 1} and R ^2. The oligophenol compound according to the present invention is not limited to the following examples.

Among them, as the oligophenol compound according to the present invention, compound (P-3), compound (P-4), compound (P-5), compound (P-6), compound (P-7), compound ( P-11), compound (P-14), compound (P-15) are preferable, and compound (P-6) is particularly preferable. Such a mixture of oligophenol compounds can be particularly preferably used as a raw material for a resin or a color developer.

[Manufacturing of oligophenol]
The oligophenol of the present invention can be easily produced by a known method, for example, by condensing corresponding aldehydes, acetals, thioacetals, trioxane and other aldehydes with phenols under an acid catalyst. As an example, a method of reacting an aldehyde compound represented by the following formula (4) with a phenol compound represented by the following formula (5) can be mentioned.

(In the formula (4), R ¹ is synonymous with ^{R 1} in the formula (1).)

(In the formula (5), R ² is synonymous with ^{R 2} in the formula (1).)

<Aldehydes>
The aldehydes used in the production of the oligophenol of the present invention represent at least one selected from the group consisting of aldehyde compounds and their corresponding acetal compounds, thioacetal compounds, trioxane compounds and the like, and among them, production of by-products. Aldehyde compounds are preferable because the amount is small, the purification process can be simplified and the amount of waste is small because the main by-product is water.

Specific examples of the aldehyde compound include linear alkyl aldehydes, branched alkyl aldehydes, and alkyl aldehydes having a partially cyclic structure. Of these, when the oligophenol of the present invention is used as a resin raw material, a linear alkyl aldehyde or a branched alkyl aldehyde is preferable in that characteristics such as mechanical strength of the obtained resin are easily exhibited. It is particularly preferably a linear alkyl aldehyde.

Specific examples of the linear alkyl aldehyde include n-heptanal, n-octanal, n-nonanal, n-decanal, n-undecanal, n-dodecanal, n-tridecanal, and n-tetradecanal. , N-nonanal, n-decanal, n-undecanal, n-dodecanal and other linear alkylaldehydes having 8 to 12 carbon atoms are preferable, and n-dodecanal is particularly preferable.

Specific examples of branched alkyl aldehydes include
Methylpentylaldehyde, methylhexylaldehyde, methylheptylaldehyde, methyloctylaldehyde, methylnonalaldehyde, methyldecylaldehyde, methylundecylaldehyde, methyldodecylaldehyde;
Dimethylpentylaldehyde, dimethylhexylaldehyde, dimethylheptylaldehyde, dimethyloctylaldehyde, dimethylnonalaldehyde, dimethyldecylaldehyde;
Trimethylhexyl aldehyde, trimethyl heptyl aldehyde, trimethyl octyl aldehyde, trimethyl nonanal aldehyde, trimethyl decyl aldehyde;
Ethylbutyraldehyde, ethylpentylaldehyde, ethylhexylaldehyde, ethylheptylaldehyde, ethyloctylaldehyde, ethylnonalaldehyde, ethyldecylaldehyde, ethylundecylaldehyde;
Propylhexyl aldehyde, propyl heptyl aldehyde, propyl octyl aldehyde, propyl nonanal aldehyde, propyl decyl aldehyde;
Butyrhexyl aldehyde, butyl heptyl aldehyde, butyl octyl aldehyde, butyl nonanal aldehyde;
And so on.

Of these, branched alkyl aldehydes having 7 to 11 carbon atoms such as ethyl butyraldehyde, ethyl pentyl aldehyde, ethyl hexyl aldehyde, ethyl heptyl aldehyde, and ethyl octyl aldehyde are preferable, ethyl pentyl aldehyde and ethyl hexyl aldehyde are more preferable, and ethyl pentyl aldehyde is more preferable. Aldehydes are particularly preferred.

In the above example of the branched alkylaldehyde, the branching position is arbitrary.

Specific examples of alkylaldehydes having a partially cyclic structure include
Formylcyclohexane, formylcycloheptane, formylcyclooctane, formylcyclononane, formylcyclodecane, formylcycloundecane, formylcyclododecane;
Formylmethylcyclohexane, formylmethylcycloheptane, formylmethylcyclooctane, formylmethylcyclononane, formylmethylcyclodecane, formylmethylcycloundecane, formylmethylcyclododecane;
Formyldimethylcyclohexane, formyldimethylcycloheptane, formyldimethylcyclooctane, formyldimethylcyclononane, formyldimethylcyclodecane, formyldimethylcycloundecane;
Formylethylcyclohexane, formylethylcycloheptane, formylethylcyclooctane, formylethylcyclononane, formylethylcyclodecane, formylethylcycloundecane ,;
Formyl diethylcyclohexane, formyldiethylcycloheptane, formyldiethylcyclooctane, formyldiethylcyclononane;
Formylpropylcyclohexane, formylpropylcycloheptane, formylpropylcyclooctane, formylpropylcyclononane, formylpropylcyclodecane;
And so on.

Among these, a partially cyclic structure having 7 to 8 carbon atoms such as formylcyclohexane, formylcycloheptane, formylmethylcyclohexane, formylmethylcycloheptane, formylethylcyclohexane, formylethylcycloheptane, formyldimethylcyclohexane, formyldimethylcycloheptane, etc. Aldehydes having an alkyl aldehyde are preferable, aldehydes containing a cyclohexyl group are more preferable, and formylcyclohexane is particularly preferable.

In the example of the alkylaldehyde having a partially cyclic structure, the substitution position of the formyl group is arbitrary.

<Phenols>
Specific examples of the phenols represented by the formula (5) used in the production of the oligophenol of the present invention include phenol; linear alkyl groups of methylphenol, ethylphenol, n-propylphenol, and n-butylphenol. Phenol; Phenol containing branched alkyl groups of isopropylphenol, (1-methylpropyl) phenol, (2-methylpropyl) phenol, t-butylphenol; ethenylphenol, (1-propenyl) phenol, allylphenol, (1- Examples thereof include phenols containing linear or branched alkenyl groups such as butenyl) phenol, (2-butenyl) phenol, (3-butenyl) phenol, and isopropenylphenol.

Of these, when the oligophenol of the present invention is used as a resin raw material, the obtained resin is more likely to exhibit excellent properties such as heat resistance, and thus phenol or methylphenol, ethylphenol, n-propylphenol, etc. Phenol containing a group having 1 to 3 carbon atoms such as allylphenol and isopropylphenol is preferable, and phenol or phenol containing a linear group such as methylphenol, ethylphenol, n-propylphenol and allylphenol. More preferably, it is particularly preferably phenol or methylphenol, and most preferably phenol.

In the example of phenol having the above-mentioned substituent, the position of the substituent is arbitrary.

<Ratio of phenols / aldehydes>
The ratio of aldehydes to phenols in producing the oligophenol of the present invention is not particularly specified as long as the conditions for producing the oligophenol of the present invention are satisfied, but the ratio of phenols to aldehydes is usually 1 mol times or more. It is preferably 2 mol times or more, and particularly preferably 3 mol times or more. When the amount of phenols is at least the above lower limit, the oligophenol of the present invention tends to be efficiently produced, which is preferable. On the other hand, the ratio of phenols to aldehydes is usually 20 mol times or less, preferably 15 mol times or less, and particularly preferably 10 mol times or less. When the amount of phenols is not more than the above upper limit, the load of the step of separating unreacted phenols tends to be reduced in the production of the oligophenol of the present invention, which is preferable.

The average value of n in the oligophenol of the present invention can be easily controlled by the ratio of phenols / aldehydes. For example, by increasing phenols with respect to aldehydes, the average value of n of the obtained oligophenols of the present invention tends to decrease. Therefore, taking advantage of this tendency, n is determined by the ratio of phenols / aldehydes. The average value of can be controlled.

<Acid catalyst>
Examples of the acid catalyst used for producing the oligophenol of the present invention include inorganic acid catalysts such as phosphoric acid, oxalic acid, hydrochloric acid and sulfuric acid; acetic acid, trifluoroacetic acid, methanesulfonic acid, toluenesulfonic acid and trifluoromethanesulfonic acid. Organic acid catalysts such as solid acids, heterogeneous acid catalysts such as cation exchange resins, and the like. The type and amount of these acid catalysts are selected in consideration of various points such as ease of handling when producing the oligophenol of the present invention, reaction selectivity at the time of production, and cost. These acid catalysts may be used alone or in combination of two or more.

<Third component>
When producing the oligophenol of the present invention, the reaction system may contain a third component for the purpose of shortening the reaction time. Specific examples of the third component include quaternary ammonium salts such as tetraethylammonium bromide, tetrabutylammonium hydrosulfate, and tetrabutylammonium chloride; methanethiol, ethanethiol, butanethiol, octanethiol, dodecanethiol, and mercaptoacetic acid. , 3-Mercaptopropionic acid, 2-Mercaptoethanol, 2-Aminoethanethiol, Ethylthiolactic acid, Thiobutyric acid, Pentaerythritol tetrakis (Mercaptoacetic acid), 1,4-Butanediolbis (thioglycolic acid), 2-Ethylhexyl ( Examples thereof include sulfur-containing compounds such as thioglycolic acid). Of these, it is preferable to use a sulfur-containing compound as the third component because the oligophenol of the present invention can be easily produced. On the other hand, it is preferable that these third components are not contained because the separation of the oligophenol of the present invention and the third component becomes unnecessary and the purification step of the oligophenol of the present invention can be simplified. In addition, these third components may be used in a state of being supported on a resin or the like.

The amount of the third component used in producing the oligophenol of the present invention is not particularly specified as long as the oligophenol of the present invention can be efficiently produced, but the amount of the third component with respect to the aldehydes to be subjected to the reaction is usually 0.001. It is mol times or more, preferably 0.005 times or more, and particularly preferably 0.01 mol times or more. When the amount of the third component is at least the above lower limit value, the oligophenol of the present invention tends to be efficiently produced, which is preferable. The amount of the third component with respect to the aldehydes to be subjected to the reaction is usually 1 mol times or less, preferably 0.5 mol times or less, and particularly preferably 0.2 mol times or less. When the amount of the third component is not more than the above upper limit value, the load of the step of separating the third component after the reaction tends to be reduced in the production of the oligophenol of the present invention, which is preferable. These third components may be used alone or in combination of two or more.

<Solvent>
When producing the oligophenol of the present invention, a solvent may be used. Specific examples of the solvent include a linear hydrocarbon solvent having 5 to 18 carbon atoms such as n-pentane, n-hexane, n-heptane, n-octane and petroleum ether; and a branch having 5 to 18 carbon atoms such as isooctane. Chain hydrocarbon solvent; cyclic hydrocarbon solvent having 5 to 18 carbon atoms such as cyclohexane, cyclooctane and methylcyclohexane; water; linear alcohol solvent such as ethanol and n-butanol; isopropanol, 2-butanol, isobutanol and the like Branched chain alcohol solvent; nitrile solvent such as acetonitrile; ether solvent such as dibutyl ether; ketone solvent such as methyl ethyl ketone and methyl isobutyl ketone; ester solvent such as ethyl acetate and butyl acetate; nitrogen-containing solvent such as dimethylformamide and dimethylacetamide. Sulfur-containing solvents such as dimethyl sulfoxide and sulfolane; chlorine-containing solvents such as methylene chloride, chloroform and dichloroethane; aromatic hydrocarbon solvents such as benzene, toluene and xylene can be mentioned. It is preferable to use these solvents because the operability of the reaction can be improved, such as suppressing the solidification of the raw material during the reaction and suppressing an unexpected side reaction due to internal heat generation. As the reaction solvent, a solvent containing at least one of water or a hydrocarbon solvent is used because it prevents unexpected side reactions between the solvent and the raw material and facilitates the removal of by-products during the production of the oligophenol of the present invention. It is preferable to use it. On the other hand, it is preferable not to use these solvents because the separation of the oligophenol of the present invention and the solvent becomes unnecessary and the purification step of the oligophenol of the present invention can be simplified.

The amount of the solvent used for producing the oligophenol of the present invention is not particularly specified as long as the oligophenol of the present invention can be produced efficiently, but the amount of the solvent with respect to the aldehydes to be subjected to the reaction is usually 0.1% by mass or more. Yes, preferably 0.2 mass times or more, and particularly preferably 0.5 mass times or more. When the amount of the solvent is at least the above lower limit value, the effect of the solvent tends to be exhibited more efficiently during the production of the oligophenol of the present invention, which is preferable. The amount of the solvent with respect to the aldehydes to be subjected to the reaction is usually 20 times by mass or less, preferably 10 times by mass or less, and particularly preferably 5 times by mass or less. When the amount of the solvent is not more than the above upper limit value, the oligophenol of the present invention tends to be efficiently produced, which is preferable.

<Reaction temperature>
The reaction temperature at the time of producing the oligophenol of the present invention is usually 0 ° C. or higher, preferably 15 ° C. or higher, and particularly preferably 30 ° C. or higher. When the reaction temperature is at least the above lower limit value, it tends to be easy to prevent the reaction mixture from solidifying, which is preferable. On the other hand, the reaction temperature is usually 150 ° C. or lower, preferably 120 ° C. or lower, and particularly preferably 90 ° C. or lower. When the reaction temperature is not more than the above upper limit value, the oligophenol of the present invention tends to be efficiently produced, which is preferable.

<Acid catalyst removal process>
The step of producing the oligophenol of the present invention preferably includes a step of removing the acid catalyst used after the reaction. Specific examples of the acid catalyst removal step include a base neutralization step, a removal step by dissolving in a solvent, a removal step by filtration, and the like. Of these, when an inorganic acid catalyst or an organic acid catalyst is used as the acid catalyst, a neutralization step with a base is included, and when a heterogeneous acid catalyst is used, a removal step by filtration is included. It tends to be able to remove the catalyst, which is preferable. The acid catalyst removing steps may be used alone or in combination of two or more.

When these removal steps are carried out, it is preferable to carry out the reaction mixture containing the oligophenol of the present invention obtained through the reaction in a state of being dissolved or suspended in a solvent. Specific examples thereof include a solvent that can be used in producing the oligophenol of the present invention. Of these solvents, it is preferable to use a solvent selected from at least one of the hydrocarbon solvents because the purification treatment of the oligophenol of the present invention can be facilitated and the cost at the time of production can be reduced. It is particularly preferable to use a solvent containing a hydrocarbon solvent. These solvents may be used alone or in combination of two or more. When a solvent is used in the reaction step of the oligophenol of the present invention, the solvent may be used as it is as the solvent in the removal step.

Specific examples of the base used in the base neutralization step include sodium hydrogen carbonate, potassium hydrogen carbonate, sodium carbonate, potassium carbonate, cesium carbonate, sodium acetate, potassium acetate, cesium acetate, sodium hydroxide, potassium hydroxide, and phosphorus. Inorganic bases having alkali metal atoms or alkaline earth metal atoms such as sodium monohydrogen acid, potassium monohydrogen phosphate, sodium phosphate, potassium phosphate, magnesium hydroxide, calcium hydroxide, sodium hydride, sodium amide; Organic bases having alkali metal atoms or alkaline earth metal atoms such as sodium acid, potassium citrate, sodium succinate, potassium succinate, calcium succinate, sodium methoxyde, potassium methoxyde, potassium-tert-butoxide; pyridine, Examples thereof include nitrogen-containing compounds such as aniline, triethylamine, N, N-dimethylaniline, morpholine, 1,4-diazabicyclo [2,2,2] octane, and diazabicycloundecene. Of these, sodium hydrogen carbonate, potassium hydrogen carbonate, sodium carbonate, potassium carbonate, cesium carbonate, sodium acetate, potassium acetate, cesium acetate, sodium hydroxide, potassium hydroxide, sodium monohydrogen phosphate, potassium monohydrogen phosphate, Bases having alkali metal atoms or alkaline earth metal atoms such as sodium phosphate, potassium phosphate, magnesium hydroxide, calcium hydroxide, sodium hydride, sodium citrate, potassium citrate, sodium succinate, potassium succinate, etc. It is preferable to use it because it facilitates removal of the neutralizing salt. In addition, these bases may be used alone or in combination of two or more.

In the neutralization step, a second component may be added for the purpose of adjusting the acidity of the reaction mixture. Specific examples thereof include organic acids such as acetic acid, citric acid, succinic acid and malic acid; heteroatoms other than oxygen such as phosphoric acid, sodium dihydrogen phosphate, potassium dihydrogen phosphate, ammonium chloride and monosodium citrate. Examples include acids containing. The type and amount of the second component are variously selected depending on the type and amount of the acid catalyst used in the reaction step and the base used in the neutralization step, and the target value of the acidity of the reaction mixture after neutralization.

It is preferable that the reaction mixture after the neutralization step is weakly acidic or weakly basic because the stability of the oligophenol of the present invention tends to be improved. When the reaction mixture is weakly acidic or weakly basic, the pH of the aqueous layer is usually 2 or more when water is added to the mixture to adjust the mass ratio of water and other components to 1: 3. It means that it is preferably 3 or more, particularly preferably 4 or more, usually 11 or less, preferably 10 or less, and particularly preferably 9 or less. When the pH of the aqueous layer is within the above range, the stability of the oligophenol of the present invention tends to be improved, which is preferable.

Specific examples of the solvent used in the acid catalyst removal step by dissolving in a solvent include water; organic solvents such as methanol, ethanol, propanol, dimethyl sulfoxide, diethyl ether, and N-methylpyrrolidone. Of these, it is preferable to use water because the purification process can be simplified.

In the acid catalyst removal step by dissolving in a solvent, a second component may be added in order to increase the removal efficiency. Specific examples thereof include organic salts such as sodium methanesulfonate; and inorganic salts such as sodium chloride and sodium sulfate. The type and amount of the second component are variously selected depending on the removal efficiency of the acid catalyst.

Filter agents used in the acid catalyst removal step by filtration include powdery, crushed or spherical filters such as activated carbon, silica gel, activated clay, and diatomaceous earth; fibrous or cloth-like filters such as filter paper, filter cloth, and thread-wound filter. Examples thereof include a filter agent molded into the above. Various filters are selected based on the properties of the acid catalyst used, the possibility of reusing the acid catalyst, and the like.

In addition, these removal steps are a part of components other than the oligophenol and the acid catalyst of the present invention such as the second and third components used at the time of the reaction or in the removal step of the unreacted raw materials, by-products, reaction or acid catalyst, or It may also serve as a step of removing all of them.

<Concentration process>
The method for producing an oligophenol of the present invention is a low boiling point component such as a solvent or an unreacted raw material from a reaction mixture containing the oligophenol of the present invention obtained through the reaction step or the acid removal step, preferably both steps. It is preferable to include a step of removing the solvent by concentration (hereinafter, may be referred to as a concentration step). By carrying out this step, when the oligophenol of the present invention is used as a resin raw material, its handleability tends to be improved. The concentration step is usually carried out under heating and depressurizing conditions. The heating temperature is preferably 40 ° C. or higher, more preferably 60 ° C. or higher, and particularly preferably 80 ° C. or higher. Further, it is usually 200 ° C. or lower, preferably 180 ° C. or lower, and particularly preferably 160 ° C. or lower. When the heating temperature is within the above temperature range, the concentration step can be efficiently carried out, and the decomposition of the oligophenol of the present invention tends to be suppressed. The heating temperature in this concentration step refers to the temperature of the heat medium used for heating. The degree of decompression is usually less than 760 Torr, preferably 200 Torr or less, more preferably 100 Torr or less, and particularly preferably 50 Torr or less. When the degree of decompression is not more than the above upper limit value, the concentration step tends to be carried out efficiently. On the other hand, the lower limit of the degree of decompression is not particularly specified, but is usually 0.1 Torr or more, preferably 1 Torr or more, and more preferably 10 Torr or more from the viewpoint that a widely and generally used decompression device can be used. , Particularly preferably 20 Torr or more.

<Rough purification process>
When producing the oligophenol of the present invention, a reaction mixture obtained through the above-mentioned reaction between aldehydes and phenols, a subsequent acid catalyst removal step, or an acid catalyst removal step and a concentration step is usually used in the present invention. It is a mixture containing the oligophenol as the main component. The step of producing the oligophenol of the present invention includes a crude purification step of roughly removing components other than the oligophenol of the present invention from the reaction mixture containing the oligophenol of the present invention as a main component, prior to the precipitation step described later. Is preferable.
In this crude purification step, preferably, the oligophenol of the present invention is extracted from the reaction mixture with an extraction solvent, the extractor layer containing the oligophenol of the present invention is washed with water, and then the extractor layer is subjected to reduced pressure. This is done by removing the extraction solvent with.

The extraction solvent used for this extraction may be a good solvent of the oligophenol of the present invention, and is not particularly limited. Specific examples thereof include a solvent that can be used for producing the oligophenol of the present invention. Among them, those excluding water and the like can be mentioned. Of these, it is preferable to contain at least one of a solvent selected from an ether solvent, a ketone solvent, an ester solvent, a chlorine-containing solvent, and an aromatic hydrocarbon solvent, because the oligophenol of the present invention can be easily extracted. It is more preferable to contain at least a solvent selected from any of an ether solvent, a ketone solvent, an ester solvent, a chlorine-containing solvent, and an aromatic hydrocarbon solvent, and particularly preferably to contain at least a solvent selected from the aromatic hydrocarbon solvent. Among them, it is preferable to contain a solvent or xylene, and it is most preferable to contain a solvent.
These extracts may be used alone or in combination of two or more.

The extraction solvent is preferably used in an amount of 0.1% by mass or more, more preferably 0.5% by mass or more, and particularly preferably 1% by mass or more with respect to the reaction mixture. When the amount of the extraction solvent is at least the above lower limit value, the oligophenol of the present invention tends to be efficiently extracted. The extraction solvent is preferably used in an amount of 20 times by mass or less, more preferably 10 times by mass or less, and particularly preferably 5 times by mass or less with respect to the reaction mixture. When the amount of the extraction solvent is not more than the above upper limit value, the production efficiency of the oligophenol of the present invention tends to be improved.

The amount of water used for washing the extractor layer containing the oligophenol of the present invention obtained by extraction is usually 0.1% by mass or more, 0.5% by mass or more, based on the total amount of the extraction layer. The above is preferable, and it is particularly preferable that the mass is 1 mass or more. When the amount of water is equal to or higher than the above lower limit, the purification efficiency in the crude purification step tends to improve. The amount of water is usually 10 times by mass or less, preferably 5 times by mass or less, and particularly preferably 3 times by mass or less with respect to the total amount of the extractor layer. When the amount of water is not more than the above upper limit value, the production efficiency of the oligophenol of the present invention tends to be improved.

The number of times the extractant layer is washed with water is usually about 1 to 20 times, preferably 2 to 10 times, and particularly preferably 3 to 6 times. When the number of washings with water is not less than the above lower limit value, the purification efficiency in the crude purification step tends to be improved, and when it is not more than the above upper limit value, the production efficiency of the oligophenol of the present invention tends to be improved.

When the extraction solvent is removed after the washing with water, it is usually carried out at a temperature of 40 to 200 ° C. under a reduced pressure of 760 to 1 Torr. The above-mentioned temperature represents the temperature of the heat medium used.

The crude purification step may be carried out in combination with the acid catalyst removing step and the concentration step described above.

<Precipitation process>
The method for producing an oligophenol of the present invention is a crude reaction mixture containing the oligophenol of the present invention, preferably a crude oligophenol of the present invention which has undergone purification steps such as the acid removal step, the concentration step, and the crude purification step. From the refined product (hereinafter, may be referred to as "the crude product of the present invention"), a part of the oligophenol of the present invention or the oligo of the present invention contained in the crude product of the present invention such as a by-product. It may include a step of precipitating and taking out a component other than phenol (hereinafter, may be referred to as a "precipitation step"). By going through this precipitation step, it tends to be easy to control the average value of n of the oligophenol of the present invention, and it is easy to reduce components other than the oligophenol of the present invention such as by-products. For example, the average value of n of the oligophenol of the present invention can be controlled by changing the type of solvent used in the present precipitation step, the precipitation conditions, and the like.

In the present precipitation step, the crude product of the present invention is usually dissolved in a solvent to prepare a solution, and then the oligophenol of the present invention contained in the crude product of the present invention such as a part of the oligophenol of the present invention or a by-product is contained. It is carried out by precipitating components other than the above. Specific examples of the crystallization solvent include specific examples of solvents that can be used in producing the oligophenol of the present invention. These solvents may be used alone or in combination of two or more. Of these, it is preferable to use a solvent containing water or a hydrocarbon solvent in that the purification efficiency of the oligophenol of the present invention is improved and the production is facilitated, and it is particularly preferable to contain a hydrocarbon solvent. Among them, it is preferable to contain a saturated chain hydrocarbon solvent such as the above-mentioned linear hydrocarbon solvent having 5 to 18 carbon atoms and a branched chain hydrocarbon solvent having 5 to 18 carbon atoms.

The melting point of the solvent is usually 30 ° C. or lower, but it is preferably 15 ° C. or lower, more preferably 5 ° C. or lower, and −10 ° C. or lower in terms of facilitating the production of the oligophenol of the present invention. It is particularly preferable to have. The lower limit of the melting point is not particularly specified as long as the boiling point of the solvent is within the range described later. Here, the melting point of the solvent represents the melting point of the solvent after mixing when two or more kinds of solvents are mixed and used.

The boiling point of the solvent is usually 40 ° C. or higher, preferably 50 ° C. or higher, and more preferably 60 ° C. or higher. On the other hand, it is usually 150 ° C. or lower, preferably 135 ° C. or lower, and more preferably 120 ° C. or lower. When the boiling point is at least the above lower limit value, the purification efficiency of the oligophenol of the present invention tends to be improved, and when it is at least the above upper limit value, the solvent is efficiently removed from the oligophenol of the present invention, and the present invention It is preferable because the production of oligophenol tends to be easy. Here, the boiling point of the solvent represents the boiling point of the mixed solvent when two or more kinds of solvents are mixed and used.

The mixing ratio of the crude product of the present invention and the above-mentioned crystallization solvent is not particularly specified as long as the target component can be efficiently precipitated, but usually, the total crystallization solvent of the crude product of the present invention is used. The mass ratio is preferably 0.2 times or more, more preferably 0.5 times or more, and particularly preferably 1 time or more. On the other hand, it is preferably 100 times or less, more preferably 50 times or less, and particularly preferably 10 times or less. When the mass ratio of the total crystallization solvent is at least the above lower limit value, the oligophenol of the present invention tends to be preferentially precipitated, while when it is at least the above upper limit value, the oligophenol of the present invention is produced. It tends to improve efficiency, which is preferable.

When two or more kinds of solvents are used as the crystallization solvent when mixing the crude product of the present invention and the crystallization solvent, even if each solvent is added separately, the crude product of the present invention is mixed in advance. May be mixed with. From the viewpoint of improving the production efficiency of the oligophenol of the present invention, it is preferable that each solvent is mixed in advance.

The temperature at which the crude product of the present invention and the crystallization solvent are mixed is usually 0 ° C. or higher, preferably 20 ° C. or higher, particularly preferably 40 ° C. or higher, and usually below the boiling point of the crystallization solvent, preferably (crystallization). The boiling point of the solvent is −5) ° C. or lower, more preferably (boiling point of the crystallization solvent −10) ° C. or lower, and particularly preferably (boiling point −20) ° C. or lower of the crystallization solvent. When the temperature at the time of mixing is equal to or higher than the above lower limit value, the solvent solubility of the crude product of the present invention can be improved and the solution can be efficiently dissolved, which is preferable. On the other hand, when the temperature at the time of mixing is not more than the above upper limit value, boiling and volatilization of the solvent can be suppressed and the crude product of the present invention can be efficiently dissolved, which is preferable. Here, when two or more of the above-mentioned solvents are mixed and used as the crystallization solvent, the boiling point of the above-mentioned solvent represents the boiling point of the mixed solvent.

In the step of precipitating components other than the oligophenol of the present invention contained in the crude product of the present invention, such as the oligophenol of the present invention or by-products, from a solution obtained by dissolving the crude product of the present invention in a crystallization solvent, cooling is performed. Various methods generally used for crystallization from a solution can be applied, such as precipitation by, adding a poor solvent, and evaporating the solvent. Of these, it is preferable to include a step of precipitating by cooling in that the oligophenol of the present invention can be easily produced. The temperature at which components other than the oligophenol of the present invention contained in the crude product of the present invention such as the oligophenol of the present invention or by-products are precipitated is not particularly limited as long as the characteristics of the oligophenol of the present invention are not impaired. Although it can be set as appropriate, it is usually −20 ° C. or higher, preferably −10 ° C. or higher, and more preferably 0 ° C. or higher. On the other hand, it is usually lower than the above mixing temperature, preferably 70 ° C. or lower, preferably 65 ° C. or lower, more preferably 60 ° C. or lower, particularly preferably 55 ° C. or lower, still more preferably 50 ° C. or lower. be. When the temperature at the time of precipitation is within the above range, the production efficiency of the oligophenol of the present invention tends to be improved, which is preferable.

In the step of precipitating the oligophenol of the present invention from a solution in which the crude product of the present invention is dissolved in a crystallization solvent, a seed crystal of the oligophenol of the present invention may be added in order to improve the precipitation efficiency. The amount of seed crystals is usually 0.0001 to 10% by mass ratio with respect to the crude product of the present invention containing the oligophenol of the present invention from the viewpoint of improving the production efficiency of the oligophenol of the present invention, and is 0. It is preferably 0005 to 5%, and particularly preferably 0.001 to 1%.

After precipitating components other than the oligophenol of the present invention contained in the crude product of the present invention such as the oligophenol of the present invention or by-products in the above precipitation step, solid-liquid separation is performed by filtration, centrifugation, decantation or the like. By doing so, components other than the oligophenol of the present invention contained in the crude product of the present invention, such as the oligophenol of the present invention or by-products, are recovered from the crystallization solvent used. After the components other than the oligophenol of the present invention contained in the crude product of the present invention such as by-products are precipitated and solid-liquid separated, the oligophenol of the present invention contained in the separation liquid is subjected to the above-mentioned concentration step and precipitation step. Separate and collect by such means.

The number of precipitation steps is variously selected according to the degree of purification of the oligophenol of the present invention, but from the viewpoint of simplifying the purification process, it is usually preferably 3 times or less, and more preferably 2 times or less. It is preferable, and it is particularly preferable that it is once.

<Washing process>
The oligophenol of the present invention obtained in the above precipitation step may be further washed with a solvent for the purpose of surface washing. Specific examples of the solvent used in this washing step include the solvent exemplified as the crystallization solvent. The temperature of the main cleaning treatment is usually −20 ° C. or higher, preferably −10 ° C. or higher, particularly preferably 0 ° C. or higher, and usually 70 ° C. or lower, preferably 60 ° C. or lower, particularly preferably 50 ° C. or lower. When the washing temperature is within the above range, it tends to be possible to suppress excessive dissolution of the oligophenol of the present invention in the cleaning solvent, which is preferable.

<Drying process>
The oligophenol of the present invention obtained through the above-mentioned precipitation step or the precipitation step and the washing step is further subjected to solvent removal treatment by heating, depressurization, air drying, etc. to obtain the oligophenol of the present invention substantially containing no solvent. Is also good. The temperature at the time of the desolvation treatment in this drying step is usually 20 ° C. or higher, preferably 40 ° C. or higher in order to allow the desolvation treatment to proceed smoothly. The upper limit of the drying temperature is usually equal to or lower than the melting point of the oligophenol of the present invention, preferably 100 ° C. or lower, further preferably 75 ° C. or lower, and particularly preferably 72 ° C. or lower.

<Use>
The oligophenol of the present invention can be used in various applications such as optical materials, recording materials, insulating materials, transparent materials, electronic materials, adhesive materials, and heat-resistant materials. Here, as the usage form of the oligophenol of the present invention used for this purpose, it may be used without polymerization or as a polymerized resin. Examples of use without polymerization include pH adjusters, surfactants, color formers, synthetic intermediates and the like. On the other hand, examples of the polymerized resin include various thermoplastic resins such as polyether resin, polyester resin, polycarbonate resin and polyurethane resin, and various thermosetting resins such as epoxy resin, unsaturated polyester resin and phenol resin. Examples thereof include a resin composition and a resin obtained by polymerizing the composition.
Here, the oligophenol of the present invention is preferably used as a resin obtained by polymerizing an oligophenol mixture. Among these, it is preferable to use a polyester resin, a polycarbonate resin, a resin composition for an epoxy resin, and a resin obtained by polymerizing the composition, because the properties derived from the oligophenol of the present invention are easily exhibited. , It is more preferable that it is for an epoxy resin, and it is particularly preferable that it is for an epoxy resin.

Hereinafter, the epoxy resin composition of the present invention using the oligophenol of the present invention and the cured epoxy resin composition of the present invention obtained by polymerizing and curing the same will be described.

[Epoxy resin composition]
The epoxy resin composition of the present invention is characterized by containing the oligophenol of the present invention. The epoxy resin composition of the present invention has an excellent feature that it becomes a resin having excellent stress relaxation during curing and polymerization by containing the oligophenol of the present invention. The epoxy resin composition of the present invention is particularly suitable for adhesives, paints, materials for civil engineering and construction, as well as electrical and electronic materials.

The epoxy resin composition of the present invention is characterized by containing (A) an epoxy resin in addition to the oligophenol of the present invention. In addition to these components, (B) phenol resins other than the oligophenols of the present invention (hereinafter referred to as "other phenol resins") are referred to as, as long as the effects expressed by the oligophenols of the present invention are not significantly impaired. In some cases, it may contain (C) a curing accelerator, (D) a filler, (E) other additives, (F) a solvent and the like.

<(A) Epoxy resin>
The epoxy resin (A) contained in the epoxy resin composition of the present invention preferably has two or more epoxy groups in the molecule. Specifically, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, phenol aralkyl type epoxy resin, biphenyl type epoxy resin, triphenylmethane Various epoxy resins such as type epoxy resin and dicyclopentadiene type epoxy resin can be used. In addition, for example, "Plastic Functional Polymer Materials Dictionary" (1st edition, Industrial Research Council, 2004), pp. 448-465, "Overview Epoxy Resin Volumes 1 to 4" (1st Edition, Epoxy Resin Technology) Association, 2003) or "Review Epoxy Resin Recent Progress I" (1st Edition, Epoxy Resin Technology Association, 2009) may be used. It should be noted that these may be used alone or in any combination and ratio of two or more.

<(B) Other phenolic resins>
The epoxy resin composition of the present invention may contain (B) another phenol resin as long as the effects expressed by the oligophenol of the present invention are not significantly impaired. Specific examples thereof include bisphenol A, bisphenol F, bisphenol S, bisphenol AD, hydroquinone, resorcin, methylresorsin, biphenol, tetramethylbiphenol, dihydroxynaphthalene, dihydroxydiphenyl ether, thiodiphenols, phenol novolac resin, and cresol novolac resin. Multivalent values such as phenol aralkyl resin, trisphenol methane resin, biphenyl aralkyl resin, naphthol aralkyl resin, terpenphenol resin, dicyclopentadienephenol resin, bisphenol A novolak resin, naphthol novolac resin, brominated bisphenol A, brominated phenol novolac resin. Phenols; Polyhydric phenol resins obtained by the condensation reaction of phenols with aldehydes such as benzaldehyde, hydroxybenzaldehyde, Crotonaldehyde, and glioxal; Polyvalent phenol resins obtained by the condensation reaction of xylene resin and phenols; Examples thereof include phenol resins such as heavy oils, pitches, phenols and co-condensation resins of formaldehydes. Of these, phenol novolac resin, phenol aralkyl resin, trisphenolmethane resin, biphenyl aralkyl resin, naphthol aralkyl resin, phenol / benzaldehyde / xylylene dimethoxide polycondensate, phenol / benzaldehyde / 4,4'-dimethoxybiphenyl polycondensate. Things such as things are preferable. These other phenolic resins may be used alone or in combination of two or more.

When (B) other phenol resin is contained, it is relative to (B) the total amount of the other phenol resin and the oligophenol of the present invention in the epoxy resin composition of the present invention (hereinafter, may be referred to as "total amount of phenol"). The mass ratio of the oligophenol of the present invention is usually 1% by mass or more, preferably 5% by mass or more, particularly preferably 10% by mass or more, still more preferably 20% by mass or more. On the other hand, it is usually 99% by mass or less, preferably 97% by mass or less, particularly preferably 90% by mass or less, and further preferably 90% by mass or less. When the mass ratio of the oligophenol of the present invention is at least the above lower limit value, the effect of the oligophenol of the present invention tends to be easily exerted. On the other hand, when it is equal to or less than the above upper limit value, the effect of (B) other phenolic resins tends to be easily exerted.

<Mole ratio of epoxy group to hydroxyl group>
The ratio of the total amount of (A) epoxy resin and phenol (total of oligophenol of the present invention and (B) other phenolic resin) in the epoxy resin composition of the present invention is the molar ratio of epoxy groups and hydroxyl groups contained therein. Is regulated. That is, (A) the total amount of hydroxyl groups contained in the total amount of phenol with respect to the total amount of epoxy groups contained in the epoxy resin (hereinafter, may be referred to as "total hydroxyl groups / total epoxy groups") is usually 0.2 mol times. The above is preferably 0.5 mol times or more, particularly preferably 0.8 mol times or more, and further preferably 0.9 mol times or more. On the other hand, it is usually 2 mol times or less, preferably 1.5 mol times or less, particularly preferably 1.2 mol times or less, and further preferably 1.1 mol times or less. When the molar ratio of total hydroxyl groups / total epoxy groups is within the above range, it tends to be possible to form a cured resin product having excellent moldability and strength during curing polymerization. The total hydroxyl group / total epoxy group can be obtained from the epoxy equivalent and the hydroxyl value specified in JIS K7236: 2009 and JIS K0070: 1992, respectively.

<(C) Curing accelerator>
The epoxy resin composition of the present invention may contain (C) a curing accelerator for the purpose of controlling the reactivity at the time of curing polymerization. Specific examples thereof include imidazole-based curing accelerators, tertiary amine-based curing accelerators, organic phosphine-based curing accelerators, phosphonium salt-based curing accelerators, tetraphenylboron salt-based curing accelerators, metal-based curing accelerators, and organic substances. Examples thereof include acid dihydrazide and boron halide amine complex.

Specific examples of the imidazole-based curing accelerator include 2-methylimidazole, 2-undecyl imidazole, 2-heptadecyl imidazole, 1,2-dimethyl imidazole, 2-ethyl-4-methyl imidazole, 2-phenyl imidazole, 2 −Phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2 -Ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecyl imidazolium trimerite, 1-cyanoethyl-2-phenylimidazolium trimerite, 2,4-diamino- 6- [2'-methylimidazolyl- (1')] -ethyl-s-triazine, 2,4-diamino-6- [2'-undecylimidazolyl- (1')]-ethyl-s-triazine, 2 , 4-Diamino-6- [2'-ethyl-4'-methylimidazolyl- (1')] -ethyl-s-triazine, 2,4-diamino-6- [2'-methylimidazolyl- (1') ] -Ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid-a] benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium citrate adduct, 2-phenyl-4,5-dihydroxy Imidazole compounds such as methylimidazole, 2-phenyl-4-methyl-5 hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo [1,2 lolide, 2-methylimidazoline, 2-phenylimidazolin, and imidazole compounds and epoxy resins. The adduct body with.

Specific examples of the tertiary amine-based curing accelerator include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, and 2,4,6, -tris (dimethylaminomethyl) phenol. , 1,8-Diazabicyclo (5,4,0) -Undecene and the like, and adducts of these tertiary amine compounds and epoxy resins.

The content of the imidazole-based curing accelerator and the amine-based curing accelerator contained in the epoxy resin composition of the present invention is preferably large in that the epoxy resin composition of the present invention can be sufficiently cured in a short time. .. On the other hand, the epoxy resin composition of the present invention is preferably stable in storage, has a low coefficient of thermal expansion, and is less likely to be affected by the curing accelerator on the cured product. Specifically, it is preferably used so as to be 0.1% by mass or more, and 0.2% by mass or more, based on the total amount of the epoxy resin (A) contained in the epoxy resin composition of the present invention. On the other hand, it is more preferable to use it so as to be 20% by mass or less, and it is further preferable to use it so as to be 10% by mass or less.

Examples of the organic phosphine-based curing accelerator, phosphonium salt-based curing accelerator, and tetraphenylboron salt-based curing accelerator include triphenylphosphine, diphenyl (p-tolyl) phosphine, tris (alkylphenyl) phosphine, and tris (alkoxyphenyl) phosphine. , Tris (alkyl / alkoxyphenyl) phosphine, tris (dialkylphenyl) phosphine, tris (trialkylphenyl) phosphine, tris (tetraalkylphenyl) phosphine, tris (dialkoxyphenyl) phosphine, tris (trialkoxyphenyl) phosphine, tris (Tetraalkoxyphenyl) Organic phosphines such as phosphine, trialkylphosphine, dialkylarylphosphine, alkyldiarylphosphine; complexes of these organic phosphines and organic borons; these organic phosphines include maleic anhydride, 1,4 -Benzoquinone, 2,5-toluquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1,4-benzoquinone, 2,3-dimethoxy Examples thereof include quinone compounds such as -1,4-benzoquinone and phenyl-1,4-benzoquinone, and compounds to which a compound such as diazophenylmethane is added. In the epoxy resin composition of the present invention, these curing accelerators have a content of 0.001 mass by mass of these curing accelerators with respect to the total amount of the (A) epoxy resin contained in the epoxy resin composition of the present invention. It is preferably used so as to be% or more, more preferably 0.005% by mass or more, and on the other hand, it is preferably used so as to be 20% by mass or less, and 10% by mass or less. It is more preferable to use it so as to be 5% by mass or less.

Examples of the metal-based curing accelerator include organic metal complexes of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin, or organic metal salts. Specific examples of the organometallic complex include organic cobalt complexes such as cobalt (II) acetylacetonate and cobalt (III) acetylacetonate, organic copper complexes such as copper (II) acetylacetonate, and zinc (II) acetylacetonate. Examples thereof include organic zinc complexes such as iron (III) acetylacetonate, organic nickel complexes such as nickel (II) acetylacetonate, and organic manganese complexes such as manganese (II) acetylacetonate. Examples of the organic metal salt include zinc octylate, tin octylate, zinc naphthenate, cobalt naphthenate, tin stearate, zinc stearate and the like. Of these, from the viewpoint of solvent solubility and curability of the epoxy resin composition of the present invention, cobalt (II) acetylacetonate, cobalt (III) acetylacetonate, zinc (II) acetylacetonate, zinc naphthenate, Iron (III) acetylacetonate is preferable, and cobalt (III) acetylacetonate and zinc naphthenate are particularly preferable.

The content of the metal-based curing accelerator contained in the epoxy resin composition of the present invention is preferably high in that a conductor layer having excellent peel strength can be easily formed on the surface of a low-roughness insulating layer. On the other hand, it is preferable that the epoxy resin composition of the present invention is small in that it is excellent in storage stability and insulating properties. Therefore, the content of these metal-based curing accelerators is such that the amount of the metal derived from the metal-based curing accelerator is 500 mass ppm or less with respect to the total amount of the (A) epoxy resin contained in the epoxy resin composition of the present invention. The amount is preferably 200 mass ppm or less, and on the other hand, the amount is preferably 20 mass ppm or more, and is 30 mass ppm or more. It is more preferable that the amount is as such.

Other examples of the epoxy resin composition of the present invention include, for example, "Review Epoxy Resin Volume 1" (1st Edition, Epoxy Resin Technology Association, 2003), pp. 119-209, or "Review Epoxy Resin Recent Progress I". (1st Edition, Epoxy Resin Technology Association, 2009), pages 43-84, may be used.

<(D) Filler>
When the epoxy resin composition of the present invention contains the filler (D), the epoxy resin composition of the present invention is cured to obtain low linear expansion rate, high thermal conductivity, flame retardancy, conductivity, etc. (D) The physical properties of the filler can be imparted to the cured product. (D) The type of filler may be selected according to desired physical characteristics and the like. For example, when it is desired to obtain an insulating composition at low cost, it is preferable to use an insulating filler such as alumina, aluminum nitride, boron nitride, silicon nitride, or silica, and among these, a composition having particularly high thermal conductivity. If you want to obtain it, alumina, aluminum nitride, boron nitride and the like are preferable. When it is desired to obtain a conductive composition, it is preferable to use an electrically conductive filler such as aluminum, silver, copper, carbon, or silicon carbide. Among these, when it is desired to obtain a composition having particularly excellent processability, it is preferable to use an electrically conductive filler. , Silver is preferred.

The shape and particle size of the filler (D) are not particularly limited as long as the desired effect of containing the filler (D) is exhibited without significantly hindering the excellent physical characteristics of the epoxy resin composition of the present invention. .. However, regarding the shape of the filler (D), if it is desired to obtain a composition having excellent processability, a filler having a small surface area such as a spherical shape is a fiber in that functions such as thermal conductivity of the filler are likely to be exhibited. A filler having a large surface area such as a shape is preferable, and a filler having an intermediate surface area such as a flat shape is preferable in that it is easy to balance the two.

The particle size of the filler (D) is preferably small in that voids are unlikely to occur in the cured product obtained by curing the epoxy resin composition of the present invention, but is large in that the filler does not aggregate and easily disperses. Is preferable. Therefore, specifically, the particle size of the filler (D) is preferably 0.05 μm or more, more preferably 0.1 μm or more, particularly preferably 0.5 μm or more, and further. On the other hand, it is preferably 1000 μm or less, more preferably 200 μm or less, and particularly preferably 100 μm or less. Here, the particle size of the filler (D) can be measured by a method such as a laser diffraction / scattering method or a sedimentation method.

When the epoxy resin composition of the present invention contains (D) a filler, the content of the (D) filler is preferably large in that the effect of using the (D) filler is likely to be exhibited. It is preferable that the epoxy resin composition of the present invention is small in that it tends to be excellent in processability. Therefore, specifically, the content of the filler (D) in the epoxy resin composition of the present invention is preferably 10% by mass or more, preferably 20% by mass or more, and on the other hand, It is preferably 95% by mass or less, and more preferably 90% by mass or less. (D) The filler may be used alone or in any combination and ratio of two or more. When two or more kinds of (D) fillers are used, the total amount thereof is preferably in the above-mentioned preferable range.

<(E) Other additives>
Other additives (E) that may be contained in the epoxy resin composition of the present invention include, for example, coupling agents such as silane coupling agents and titanate coupling agents; mold release agents; ultraviolet inhibitors; oxidation. Examples thereof include an inhibitor; a plasticizer; a flux; a flame retardant; a colorant; a dispersant; an emulsifier; a low elastic agent; a diluent; an antifoaming agent; an ion trapping agent, and the like can be appropriately included as needed. However, the epoxy resin composition of the present invention does not prevent the blending of components other than those listed above.

Among these, silane coupling agents include epoxysilanes such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane; γ-Aminopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, γ-aminopropyltrimethoxysilane, γ-ureidopropyl Aminosilanes such as triethoxysilane; mercaptosilanes such as 3-mercaptopropyltrimethoxysilane; p-styryltrimethoxysilane, vinyltricrolsilane, vinyltris (8-methoxyethoxy) silane, vinyltrimethoxysilane, vinyltriethoxysilane, γ -Vinylsilanes such as methacryloxypropyltrimethoxysilanes; epoxy-based, amino-based, vinyl-based polymer-type silanes and the like can be mentioned.

Examples of the titanate coupling agent include isopropyltriisostearoyl titanate, isopropyltri (N-aminoethyl / aminoethyl) titanate, diisopropylbis (dioctylphosphate) titanate, tetraisopropylbis (dioctylphosphate) titanate, and tetraoctylbis (ditridecyl). Examples thereof include phosphite) titanate, tetra (2,2-diallyloxymethyl-1-butyl) bis (ditridecyl) phosphite titanate, bis (dioctylpyrophosphate) oxyacetate titanate, and bis (dioctylpyrophosphate) ethylene titanate.

When the epoxy resin composition of the present invention contains a coupling agent, the content of the coupling agent is preferably large in that it is easy to obtain an adhesive effect by blending the coupling agent, but it is difficult for the coupling agent to bleed out. It is preferable that the amount is small. Therefore, specifically, the content of the coupling agent with respect to the total solid content in the epoxy resin composition of the present invention is preferably 0.1% by mass or more and 2.0% by mass or less. The coupling agent may be used alone or in any combination and ratio of two or more. When two or more kinds of coupling agents are used, the total amount thereof is preferably in the above-mentioned preferable range. The total solid content in the epoxy resin composition of the present invention refers to the total of the components other than the solvent (F) described later contained in the epoxy resin composition of the present invention.

Examples of the release agent that may be contained in the epoxy resin composition of the present invention include natural waxes such as carnauba wax; synthetic waxes such as polyethylene wax; higher fatty acids such as stearic acid and zinc stearate, and metals thereof. Salts; Examples thereof include hydrocarbon release agents such as paraffin. These may be used alone or in combination of two or more in any combination and blending ratio.

When the epoxy resin composition of the present invention contains a mold release agent, the content of the mold release agent is preferably 0.1 to 5% by mass, based on the total amount of the (A) epoxy resin in the epoxy resin composition. It is preferably 0.5 to 3.0% by mass. When the content of the release agent is within the above range, it is preferable because good releasability can be exhibited while maintaining the curing characteristics of the epoxy resin composition.

Examples of the flame retardant that may be contained in the epoxy resin composition of the present invention include a halogen-based flame retardant such as a brominated epoxy resin and a brominated phenol resin, an antimony compound such as antimon trioxide, red phosphorus, and phosphoric acid. Examples thereof include phosphorus-based flame retardants such as esters and phosphins, nitrogen-based flame retardants such as melamine derivatives, and inorganic flame retardants such as aluminum hydroxide and magnesium hydroxide.

<(F) Solvent>
The epoxy resin composition of the present invention may contain a solvent (F) in order to adjust the viscosity during processing and improve the handleability during curing. Examples of the solvent (F) include a solvent that can be used when producing the oligophenol of the present invention, and specific examples thereof include ketones such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, and cyclohexanone. Esters such as ethyl acetate; Ethers such as ethylene glycol monomethyl ether; Amids such as N, N-dimethylformamide, N, N-dimethylacetamide; Alcohols such as methanol, ethanol and isopropanol; Alkanes such as hexane and cyclohexane. Alkanes; examples include aromatic hydrocarbons such as toluene and xylene. The epoxy resin composition of the present invention preferably does not use (F) a solvent or has a low solvent content, but the epoxy resin composition is high in that voids are unlikely to be formed in the cured product due to solvent residue. It is preferable to use the solvent (F) and to use a large amount of the solvent (F) in that cracks due to the viscosity are unlikely to occur. These solvents may be used alone or in any combination and ratio of two or more.

[Epoxy resin cured product]
By curing the epoxy resin composition of the present invention, the cured epoxy resin composition of the present invention can be obtained. Since the epoxy resin cured product of the present invention is obtained by curing the epoxy resin composition of the present invention containing the oligophenol of the present invention, it is excellent in stress relaxation at high temperatures. The curing method and conditions are not particularly specified as long as the epoxy resin composition of the present invention can be cured. However, thermosetting is preferable because it is easy to mold.

[Use]
The epoxy resin composition of the present invention and the cured epoxy resin obtained by curing the epoxy resin composition have excellent stress relaxation properties at high temperatures, and are used in various fields such as adhesives, paints, civil engineering and construction materials, and insulating materials in the electrical and electronic fields. It can be applied as a material for. In particular, it is useful as an insulating casting, a laminated material, a sealing material, etc. in the electrical and electronic fields.
Examples of applications of the epoxy resin composition of the present invention and its cured product include a multilayer printed wiring substrate, a film-like adhesive, a liquid adhesive, a semiconductor encapsulating material, an underfill material, an interchip fill for 3D-LSI, and insulation. Examples include sheets, prepregs, heat dissipation substrates and the like.

Examples of the present invention are shown below, but the present invention is not limited thereto.
The various analysis and evaluation methods in the examples are as follows. The symbols of the respective compounds are based on Table 1 of the above-mentioned example of the oligophenol compound represented by the above formula (1).

[Analysis of oligophenols]
<Vaporized content>
10 g of the sample was placed in a 50 ml test tube, the mass was measured, and then the test tube was heated at 120 ° C. for 2 hours under a nitrogen atmosphere. The mass of the obtained residue was measured, and the volatile content was determined by mass ratio. It was carried out twice, and the average value was taken as the volatile content.

<Average value of hydroxyl value / n>
It was measured according to JIS K0070: 1992, converted into a value per solid content excluding the volatile matter obtained in the above volatile matter analysis, and then expressed in mass grams per molar hydroxyl group in oligophenol. The average value of n was obtained according to the above-mentioned calculation formula (A).

[Epoxy resin cured product evaluation]
<Strength of epoxy resin cured film>
When the cured film of the epoxy resin composition is peeled off from the glass plate without any problem and a film having a thickness of 0.5 mm can be obtained, the film has sufficient strength (○), and the film is brittle and when peeled off from the glass plate. , The one in which the film was torn was regarded as insufficient strength (x).

<Storage modulus / Tg>
The epoxy resin cured plate is analyzed by a thermomechanical analyzer (EXSTAR6100 manufactured by Seiko Instruments Inc.) in the three-point bending mode by the following measurement method, and the storage elastic modulus (E') at 40 ° C. and 250 ° C. is determined. It was measured. The peak top of tan δ was defined as the glass transition temperature (Tg).
(Measuring method)
Temperature sweep: 5 ° C / min temperature rise, 30 ° C to 250 ° C
Frequency: 1Hz

[Example 1]
<Production of compound (P-6) (average value of n = 0.020)>
Phenol (220 g, 2.3 mol) was heated to 40 ° C. to melt it, and then 35% concentrated hydrochloric acid (2.9 g, 0.028 mol) was added. A mixed solution of n-dodecanal (86 g, 0.47 mol) and toluene (51 g) was added dropwise thereto at an internal temperature of 45 ° C. or lower over 4 hours. After the dropping, the mixture was aged at 40 ° C. for 1 hour, and then the reaction was stopped with an aqueous sodium hydrogen carbonate solution. Phenol was distilled off from the reaction mixture at 160 ° C. and 20 Torr under reduced pressure, and then the residue (181 g) was extracted with toluene (340 g) and washed 3 times with water (215 g). The solvent was distilled off at 90 ° C. under reduced pressure (20 Torr) to obtain a crude product (170 g). Toluene (430 g) and heptane (430 g) were added to the obtained crude product, and the mixture was heated to 60 ° C. to dissolve it. The temperature was lowered to an internal temperature of 15 ° C. at 10 ° C./hour and then aged for 1 hour. The obtained slurry was filtered and dried at 60 ° C. for 24 hours to obtain a white solid of compound (P-6) (94 g). This product had a volatile content of 0.4%, and the average value of n calculated from the hydroxyl value was 0.020.

<Manufacturing of epoxy resin cured film>
2.0 g of epoxy resin (tetramethylbiphenol type epoxy resin manufactured by Mitsubishi Chemical Co., Ltd., trade name YX4000 epoxy equivalent: 186 g / equivalent) and the compound (P-6) (average value of n = 0.020) obtained above are used. , Epoxy group: hydroxyl group was mixed so as to have a 1: 1 molar ratio, and 10 mg of triphenylphosphine (manufactured by Tokyo Kasei Kogyo Co., Ltd.) was further added as a curing accelerator. Then, the mixture was heated to 100 ° C. and stirred until uniform. The obtained epoxy resin composition was sandwiched between release-treated blue plate glass with a 0.5 mm silicone spacer. This was heated at 175 ° C. for 6 hours to obtain a cured film. After cooling the obtained cured film to room temperature, it was peeled off from the glass plate and the strength was evaluated.

[Example 2]
<Production of compound (P-6) (average value of n = 0.544)>
Isopropanol (77 g) and heptane (430 g) were added to the crude product obtained by reacting, concentrating, extracting, washing, and distilling off the solvent in the same manner as in Example 1, and the mixture was heated to 60 ° C. and dissolved. .. The temperature was lowered to an internal temperature of 15 ° C. at 10 ° C./hour and then aged for 1 hour. The obtained slurry was filtered and the filtrate was concentrated at 130 ° C. and 20 Torr to obtain a pale yellow paste of compound (P-6) (94 g). This product had a volatile content of 0.5%, and the average value of n calculated from the hydroxyl value was 0.544.

<Manufacturing of epoxy resin cured film>
Cured film in the same manner as in Example 1 except that compound (P-6) (average value of n = 0.544) was used instead of compound (P-6) (average value of n = 0.020). Was obtained, and its strength was evaluated.

[Comparative Example 1]
<Production of compound (P-6) (average value of n = 0.002)>
The powder obtained in the filtration step of Example 2 was sprinkled and washed at 15 ° C. with a mixed solution of isopropanol (15 g) and heptane (86 g). The obtained solid was dried under reduced pressure at 70 ° C. for 24 hours to obtain a white solid (60.2 g) of the compound (P-6). This product had a volatile content of 0.9% and an average value of n calculated from the hydroxyl value was 0.002.

<Manufacturing of epoxy resin cured film>
Cured film in the same manner as in Example 1 except that compound (P-6) (average value of n = 0.002) was used instead of compound (P-6) (average value of n = 0.020). Was obtained, and its strength was evaluated.

[Comparative Example 2]
<Production of compound (P-6) (average value of n = 0.012)>
The powder of the compound (P-6) (average value of n = 0.020) obtained in Example 1 and the compound (P-6) (average value of n = 0.002) obtained in Comparative Example 2). By mixing the powders of the above, a powder of the compound (P-6) having an average value of n = 0.012 was prepared.

<Manufacturing of epoxy resin cured film>
Cured film in the same manner as in Example 1 except that compound (P-6) (average value of n = 0.012) was used instead of compound (P-6) (average value of n = 0.020). Was obtained, and its strength was evaluated.

The results of Examples 1 and 2 and Comparative Examples 1 and 2 are shown in Table 2 below.

As is clear from Table 2, the cured films obtained by using the compounds (P-6) obtained in Examples 1 and 2 showed sufficient strength and could be obtained as a 0.5 mm thick film. On the other hand, the cured film obtained by using the compound (P-6) obtained in Comparative Example 1 and Comparative Example 2 was brittle and could not be obtained as a film. From this, it is clear that the oligophenol of the present invention exhibits a curing ability suitable as a curing agent for epoxy resins. The reason why the cured film showed sufficient strength in Examples 1 and 2 is considered to be that the cured product formed a sufficient network during polymerization.

[Examples 3 and 4, Comparative Examples 3 and 4]
<Raw materials used>
The following epoxy resins and hardeners were used.
(Epoxy resin)
EOCN: Orthocresol novolac type epoxy resin (trade name EOCN-1020-65 manufactured by Nippon Kayaku Co., Ltd. (epoxy equivalent: 199 g / equivalent))
YX4000: Tetramethylbiphenol type epoxy resin (trade name YX4000 manufactured by Mitsubishi Chemical Corporation (epoxy equivalent: 186 g / equivalent))
(Hardener)
P-6 (0.544): Compound (P-6) obtained in Example 2 (mean value of n = 0.544)
PSM6200: Phenolenovolac resin (Product name PSM6200 manufactured by Gun Ei Chemical Industry Co., Ltd. (hydroxyl equivalent: 103 g / equivalent))

<Manufacturing of epoxy resin hardened plate>
The epoxy resin (20 g) shown in Table 3 and the curing agent were mixed so that the epoxy group: hydroxyl group had a 1: 1 molar ratio, and 20 mg of triphenylphosphine (manufactured by Tokyo Chemical Industry Co., Ltd.) was further added as a curing accelerator. .. Then, the mixture was heated to 100 ° C. and stirred until uniform to obtain an epoxy resin composition.
Two glass plates in which a release PET film was laminated on one surface were prepared, and these glass plates were made with the release PET film side as the inner surface and the distance between the glass plates was adjusted to 5 mm to prepare a casting plate.
The epoxy resin composition was cast into this casting plate and cured by heating at 120 ° C. for 2 hours and then at 175 ° C. for 6 hours to obtain a cured product. The obtained cured product was cut into a length of 5 cm, a width of 1 cm, and a thickness of 4 mm to obtain an epoxy resin cured plate, which was used for measurement.

The results of Examples 3 and 4 and Comparative Examples 3 and 4 are shown in Table 3 below.

From Table 3, the epoxy resin curing plates of Examples 3 and 4 obtained by using the oligophenol of the present invention as a curing agent are cured of Comparative Examples 3 and 4 obtained by using a normal phenol resin as a curing agent. Compared with the plate, Tg and E'are reduced, and it is clear that the cured product has excellent stress relaxation properties. In particular, E'at 250 ° C. in Examples 3 and 4 is two orders of magnitude lower than that in Comparative Examples 3 and 4, and it is clear that the stress relaxation property is particularly excellent in a high temperature region.
From this, according to the oligophenol of the present invention, in electric / electronic materials such as a multilayer circuit board, cracks and warpage of the substrate caused by stress generation due to shrinkage of the resin during curing and polymerization can be improved. Therefore, it can be seen that the oligophenol of the present invention is suitable for a wide range of applications including this application.

Claims (5)

It is a mixture of oligophenol compounds composed of the compound group represented by the following formula (1), and the average value of n calculated from the hydroxyl value is in the range of 0.015 or more and 0.7 or less. A characteristic oligophenol mixture.

(In the above formula (1), n represents an integer of 0 or more, R ¹ represents a linear alkyl group having 6 or more carbon atoms and 13 or less carbon atoms, and R ² represents a hydrogen atom or a methyl group.) The oligophenol mixture according to claim 1, wherein ^{R 1} is an n-undecylic group and R ^{2 is a hydrogen atom.} A resin obtained by polymerizing the oligophenol mixture according to claim 1 or 2. An epoxy resin composition comprising the oligophenol mixture according to claim 1 or 2. An epoxy resin cured product obtained by curing the epoxy resin composition according to claim 4.