JP2021046384A - Phosphonium compound, and hardening accelerator - Google Patents

Abstract

To provide a new phosphonium compound excellent in storage stability and hardening ability when used as a hardening accelerator for an epoxy resin.SOLUTION: A phosphonium compound is represented by general formula (I), (R1A indicates a substituted or unsubstituted hydrocarbon group of 1-18 carbons; R1B indicates a substituted or unsubstituted hydrocarbon group of 1-18 carbons; n indicates an integer of 0-3; and Xa- indicates a monovalent anion of a phthalic acid derivative and a divalent anion of a tetracarboxylic acid benzene derivative).SELECTED DRAWING: None

Description

The present invention relates to phosphonium compounds and curing accelerators.

Conventionally, curable resins such as epoxy resins have been widely used in the fields of molding materials, laminated board materials, adhesive materials and the like. Since these curable resins are required to have fast curability from the viewpoint of improving productivity, a compound that promotes a curing reaction, that is, a curing accelerator is generally used in the curable resin composition. Further, in the field of sealing technology for elements of electronic components such as transistors, ICs (Integrated Circuits), and LSIs (Large Scale Integration), among curable resins, compositions based on epoxy resins are widely used. There is. The reason is that the epoxy resin is well-balanced in various properties such as moldability, electrical properties, moisture resistance, heat resistance, mechanical properties, and adhesiveness to insert products. In particular, the combination of the orthocresol novolac type epoxy resin and the phenol novolac type curing agent has an excellent balance in the above-mentioned characteristics, and therefore has become the mainstream as a base resin for a molding material for IC encapsulation. Also in such an epoxy resin composition, a curing accelerator such as an amine compound such as a tertiary amine or imidazole, a phosphorus compound such as phosphine or phosphonium is generally used.

On the other hand, in recent years, in the field of device encapsulation technology for electronic components, high-density mounting of electronic components on printed wiring boards has progressed, and along with this, surface mount type packages have become more mainstream than conventional pin insertion type packages. Is becoming. However, the surface mount type package tends to have lower resistance to package cracks during soldering, that is, so-called reflow crack resistance, as compared with the pin insertion type package. That is, in surface mount ICs such as ICs and LSIs, the volume occupied by the device with respect to the package gradually increases in order to increase the mounting density, and the wall thickness of the package becomes very thin. In addition, surface mount packages will be exposed to more severe conditions during their soldering process than pin insert packages. More specifically, in the pin insertion type package, since the pins are inserted into the wiring board and then soldered from the back surface of the wiring board, the package is not directly exposed to high temperature. On the other hand, in the surface mount type IC, the package is directly exposed to a high soldering temperature because the surface of the wiring board is temporarily fixed and then processed by a solder bath, a reflow device, or the like. As a result, when the IC package absorbs moisture, the moisture absorbed during soldering may rapidly expand and lead to package cracks, which is a big problem in package molding.

Under such circumstances, an epoxy resin composition having an increased content of an inorganic filler has been reported in order to improve the reflow crack resistance of the surface mount type package. However, as the content of the inorganic filler increases, the fluidity of the resin composition decreases, resulting in poor filling during molding, molding problems such as voids, and poor continuity due to disconnection of the bonding wire of the IC chip. In many cases, the performance of the package deteriorates. Therefore, there is a limit to the increase in the content of the inorganic filler, and as a result, it is difficult to achieve a significant improvement in reflow crack resistance. In particular, from the viewpoint of quick curing, such epoxy resin compositions include phosphorus-based curing accelerators such as triphenylphosphine, amine-based curing accelerators such as 1,8-diazabicyclo [5.4.0] undecene-7, and the like. When is added, the fluidity of the resin composition tends to be significantly reduced. Therefore, in addition to improving the reflow crack resistance of the package, it is currently desired to improve the fluidity of the resin composition. Is.

In order to improve the fluidity of an epoxy resin composition containing a high proportion of an inorganic filler, for example, a method of using an addition reaction product of triphenylphosphine and 1,4-benzoquinone as a curing accelerator has been proposed. (See, for example, Patent Document 1). Alternatively, there is a method of using tetraphenylphosphonium tetraphenylborate as a curing accelerator (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 9-157497 Special Publication No. 51-24399

However, according to the method described in Patent Document 1 in which an addition reaction product of triphenylphosphine and 1,4-benzoquinone is used as a curing accelerator, the epoxy resin composition tends to be easily affected by the outside air humidity and has poor storage stability. There is. Therefore, the package characteristics tend to vary, and strict control in the environment during manufacturing, transportation, and use is required, which tends to be inferior in handleability.
Further, according to the method described in Patent Document 2 in which tetraphenylphosphonium tetraphenylborate is used as a curing accelerator, the epoxy resin composition exhibits excellent storage stability, while it takes time for the cured product to achieve a certain hardness. This tends to reduce the productivity during sealing work.

The present disclosure has been made in view of the above-mentioned conventional circumstances, and provides a novel phosphonium compound having excellent storage stability and curability when used as a curing accelerator for an epoxy resin, and a curing accelerator containing the novel phosphonium compound. With the goal.

Specific means for achieving the above-mentioned problems are as follows.
<1> A phosphonium compound represented by the following general formula (I).

(In general formula (I), R ^1A each independently represents a substituted or unsubstituted hydrocarbon group having 1 to 18 carbon atoms. Two R ^1A arbitrarily selected from three R ^1A are linked to each other. Then, a cyclic structure may be formed together with the phosphorus atom ^{to which R 1A is bonded. R 1B} each independently represents a substituted or unsubstituted hydrocarbon group having 1 to 18 carbon atoms. N is 0 to 0. Indicates an integer of 3. If n is 2 or 3, the two ^R1Bs may be connected to each other to form a cyclic structure. A indicates 1 or 2. If a is 1, X ^{a. −} Indicates a monovalent anion represented by the following general formula (IA), and when a is 2, X a ⁻ represents a divalent anion represented by the following general formula (IB). )

(In the general formula (IA), R ^1C independently represents an alkyl group, a hydroxyl group, an amino group or an alkoxy group. P represents an integer of 0 to 4. In the general formula (IB), R ^1D represents. , Each independently indicates an alkyl group, a hydroxyl group, an amino group or an alkoxy group. Q indicates an integer of 0 to 2.)
<2> A curing accelerator containing the phosphonium compound according to <1>.

According to the present disclosure, it is possible to provide a novel phosphonium compound having excellent storage stability and curability when used as a curing accelerator for an epoxy resin, and a curing accelerator containing the novel phosphonium compound.

¹ H-NMR spectrum of the phosphonium compound 1 obtained in Example 1. It is an IR spectrum of the phosphonium compound 1 obtained in Example 1.

Hereinafter, embodiments for carrying out the present invention will be described in detail. However, the present invention is not limited to the following embodiments. In the following embodiments, the components (including element steps and the like) are not essential unless otherwise specified. The same applies to the numerical values and their ranges, and does not limit the present invention.

The numerical range indicated by using "~" in the present disclosure includes the numerical values before and after "~" as the minimum value and the maximum value, respectively.
In the numerical range described stepwise in the present disclosure, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of another numerical range described stepwise. .. Further, in the numerical range described in the present disclosure, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples.
In the present disclosure, each component may contain a plurality of applicable substances. When a plurality of substances corresponding to each component are present in the composition, the content or content of each component is the total content or content of the plurality of substances present in the composition unless otherwise specified. Means quantity.
In the present disclosure, the particles corresponding to each component may include a plurality of types of particles. When a plurality of particles corresponding to each component are present in the composition, the particle size of each component means a value for a mixture of the plurality of particles present in the composition unless otherwise specified.

<Phononium compounds>
The phosphonium compound of the present disclosure is represented by the following general formula (I).

In the general formula (I), R ^1A independently represents a substituted or unsubstituted hydrocarbon group having 1 to 18 carbon atoms. Two R ^1As , arbitrarily selected from the three R ^1A's, may be linked to each other to form a cyclic structure with the phosphorus atom ^{to which the R 1A is attached.} R ^1B each independently represents a substituted or unsubstituted hydrocarbon group having 1 to 18 carbon atoms. n represents an integer from 0 to 3. When n is 2 or 3, the two ^R1Bs may be connected to each other to form an annular structure. a indicates 1 or 2. When a is 1, X ^a- represents a monovalent anion represented by the following general formula (IA), and when a is 2, X a ⁻ is represented by the following general formula (IB). Shows a divalent anion.

In the general formula (IA), R ^1C independently represents an alkyl group, a hydroxyl group, an amino group or an alkoxy group. p represents an integer from 0 to 4. In the general formula (IB), R ^1D independently represents an alkyl group, a hydroxyl group, an amino group or an alkoxy group. q indicates an integer of 0 to 2.

In the general formula (I), ^{the substituted or unsubstituted hydrocarbon group having 1 to 18 carbon atoms represented by R 1A} or R ^1B is a hydrocarbon group having 1 to 18 carbon atoms and has a substituent. It contains a group hydrocarbon group, an aliphatic hydrocarbon group having no substituent, an aromatic hydrocarbon group having a substituent, and an aromatic hydrocarbon group having no substituent. When the hydrocarbon group has a substituent, the number of carbon atoms of the hydrocarbon group does not include the number of carbon atoms contained in the substituent.

The aliphatic hydrocarbon group may be a linear or branched saturated aliphatic hydrocarbon group or a linear or branched unsaturated aliphatic hydrocarbon group. The number of carbon atoms is 1 to 18, but from the viewpoint of storage stability, the number of carbon atoms is preferably 1 to 12, and more preferably 3 to 8.
More specifically, the aliphatic hydrocarbon group includes a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an s-butyl group, a t-butyl group, a pentyl group, a hexyl group, an octyl group and a decyl group. , Saturated aliphatic hydrocarbon groups such as dodecyl group, tetradecyl group, hexadecyl group and octadecyl group; unsaturated aliphatic hydrocarbon groups such as allyl group and vinyl group can be mentioned.

The aliphatic hydrocarbon group may be an alicyclic hydrocarbon group. The alicyclic hydrocarbon group may be an alicyclic saturated hydrocarbon group or an alicyclic unsaturated hydrocarbon group. Specific examples of the alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group and the like.

The aliphatic hydrocarbon group may have a substituent. Examples of the substituent in the aliphatic hydrocarbon group include an alkoxy group, an aryl group, a hydroxyl group, an amino group, a halogen atom and the like. When the aliphatic hydrocarbon group has a substituent, the position of the substituent and the number of the substituents are not particularly limited. If they have two or more substituents, they may be the same or different.

The aromatic hydrocarbon group preferably has 6 to 18 carbon atoms, and more preferably 6 to 14 carbon atoms. Specific examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, an anthracenyl group and the like. The aromatic hydrocarbon group may have a substituent. Examples of the substituent in the aromatic hydrocarbon group include an alkyl group, an alkoxy group, an aryl group, a hydroxyl group, an amino group, a halogen atom and the like. When the aromatic hydrocarbon group has a substituent, the position of the substituent and the number of the substituents are not particularly limited. If they have two or more substituents, they may be the same or different.

More specifically, as the substituted or unsubstituted aromatic hydrocarbon group, an aryl group such as a phenyl group or a naphthyl group; a tolyl group, a dimethylphenyl group, an ethylphenyl group, an n-butylphenyl group, a t-butylphenyl group or the like. Alkyl group-substituted aryl group; Examples thereof include an alkoxy group-substituted aryl group such as a methoxyphenyl group, an ethoxyphenyl group, a butoxyphenyl group, and a t-butoxyphenyl group. They may be further substituted with an alkyl group, an alkoxy group, an aryl group, an aryloxy group, an amino group, a halogen atom or the like.

Two R ^1A from three R ^1A in the general formula (I) is selected arbitrarily may form a cyclic structure together with the phosphorus atom to which R ^1A is attached and connected to each other. When two R ^1A and a phosphorus atom form a cyclic structure, the number of rings formed may be one or two or more. Further, the cyclic structure may include a crosslinked ring structure.
^{Specifically, R 1A} capable of forming a cyclic structure together with a phosphorus atom is an alkylene group such as an ethylene group, a propylene group, a butylene group, a pentylene group or a hexylene group; an alkenyl group such as an ethyleneyl group, a propyrenyl group or a butylenel group; An aralkylene group such as a phenylene group; an arylene group such as a phenylene group, a naphthylene group, and anthracenylene can be mentioned. These may be substituted with an alkyl group, an alkoxy group, an aryl group, an aryloxy group, an amino group, a hydroxyl group, a halogen atom or the like.

From the viewpoint of availability of raw materials, R ^1A has a phenyl group, a p-tolyl group, an m-tolyl group, an o-tolyl group, a p-methoxyphenyl group, an m-methoxyphenyl group, an o-methoxyphenyl group, p-Hydroxyphenyl group, m-hydroxyphenyl group, o-hydroxyphenyl group, 2,5-dihydroxyphenyl group, 4- (4-hydroxyphenyl) phenyl group, 1-naphthyl group, 2-naphthyl group, 1-( 2-Hydroxynaphthyl) group, 1- (4-hydroxynaphthyl) group and other unsubstituted and substituted aryl groups, as well as methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, s-butyl group, It is preferably a monovalent group selected from the group consisting of linear, branched and cyclic alkyl groups such as t-butyl group, octyl group and cyclohexyl group.
Furthermore, a phenyl group, a p-tolyl group, an m-tolyl group, an o-tolyl group, a p-methoxyphenyl group, an m-methoxyphenyl group, an o-methoxyphenyl group, a p-hydroxyphenyl group, an m-hydroxyphenyl group, o-Hydroxyphenyl group, 2,5-dihydroxyphenyl group, 4- (4-hydroxyphenyl) phenyl group, 1-naphthyl group, 2-naphthyl group, 1- (2-hydroxynaphthyl) group, 1- (4- (4-hydroxyphenyl) group It is more preferable that it is a monovalent group selected from the group consisting of an unsubstituted aryl group such as a hydroxynaphthyl) group and a substituted aryl group.

In the general formula (I), n represents an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and even more preferably 0.
When n is 2 or 3, the two ^R1Bs may be connected to each other to form an annular structure. When n is 3, two R ^1Bs arbitrarily selected from the three R ^1Bs may form an annular structure.
When two ^R1Bs form a cyclic structure, the number of rings formed may be one or two or more. Further, the cyclic structure may include a crosslinked ring structure.
^{Specific examples of R 1B} capable of forming a cyclic structure are the same as those of ^{R 1A} capable of forming a cyclic structure together with the phosphorus atom described above.

In the general formula (IA), the ^{alkyl group represented by R 1C} is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, and is preferably a methyl group, an ethyl group, an n-propyl group, or the like. Examples thereof include an isopropyl group, an n-butyl group, an s-butyl group, an isobutyl group and a t-butyl group, and a methyl group is preferable.
In the general formula (IA), the ^{alkoxy group represented by R 1C} is preferably a linear or branched alkoxy group having 1 to 4 carbon atoms, and is preferably a methoxy group, an ethoxy group, an n-propoxy group, and the like. Examples thereof include an isopropoxy group, an n-butoxy group, an s-butoxy group, an isobutoxy group, a t-butoxy group and the like, and a methoxy group is preferable.
In the general formula (IA), p is preferably an integer of 0 to 2, more preferably 0 or 1, and even more preferably 0.
Examples of the compound that is the source of the monovalent anion represented by the general formula (IA) include phthalic acid, 4-methylphthalic acid, 4-hydroxyphthalic acid, 4-aminophthalic acid, 4-methoxyphthalic acid and the like. ..

In the general formula (IB), specific examples and preferable examples of the alkyl group represented by ^{R 1D} are the same as in the case of the alkyl group ^{represented by R 1C.}
In the general formula (IB), specific examples and preferable examples of the alkoxy group represented by ^{R 1D} are the same as in the case of the alkoxy group ^{represented by R 1C.}
In the general formula (IB), q is preferably 0 or 1, more preferably 0.
Examples of the compound that is the source of the divalent anion represented by the general formula (IB) include pyromellitic acid and the like.

Phthalic acid is preferable as the compound that is the source of the monovalent or divalent anion represented by ^Xa-.

Examples of the phosphorus compounds of the present disclosure include 2,5-dihydroxyphenyl (triphenyl) phosphonium hydrogen phthalate, 2,5-dihydroxyphenyl (triphenyl) phosphonium hydrogen 4-methylphthalate, and 2,5-dihydroxyphenyl (triphenyl). ) Phosphonium Hydrogen 4-Hydroxyphthalates, 2,5-Dihydroxyphenyl (Tri-p-Tolyl) phosphonium Hydrogen phthalates, 2,5-Dihydroxyphenyl (Tri-p-Toril) phosphonium Hydrogen 4-Methylphthalates, 2, 5-Dihydroxyphenyl (tri-p-tolyl) phosphonium hydrogen 4-hydroxyphthalate, 2,5-dihydroxyphenyl (tri-n-butyl) phosphonium hydrogen phthalate, 2,5-dihydroxyphenyl (tri-n-butyl) Phosphonium Hydrogen 4-Methylphthalates, 2,5-Dihydroxyphenyl (Tri-n-Butyl) Phosphonium Hydrogen 4-Hydroxyphthalates, Bis [2,5-Dihydroxyphenyl (Triphenyl) Phosphonium] Dihydrogen Pyromericates, Bis [2,5-dihydroxyphenyl (tri-p-tolyl) phosphonium] dihydrogen pyromerite, bis [2,5-dihydroxyphenyl (tri-n-butyl) phosphonium] dihydrogen pyromerite, 1, 4-Dihydroxynaphthalenyl (triphenyl) phosphonium hydrogen phthalates, 1,4-dihydroxynaphthalenyl (tri-p-tolyl) phosphonium hydrogen phthalates, 1,4-dihydroxynaphthalenyl (tri-n-butyl) Phosphosphonium Hydrogenphthalates, Bis [1,4-Dihydroxynaphthalenyl (Triphenyl) Phosphonium] Dihydrogen Pyromeritates, Bis [1,4-Dihydroxynaphthalenyl (Tri-p-Tolyl) Phosphonium] Dihydrogen Examples thereof include pyromeritate, bis [1,4-dihydroxynaphthalenyl (tri-n-butyl) phosphonium] dihydrogen pyromerite.
The phosphonium compound of the present disclosure can be suitably used as a curing accelerator for an epoxy resin.

<Manufacturing method of phosphonium compound>
The phosphonium compound of the present disclosure may be produced by any method.
For example, ^{a solution of a phosphine compound represented by P (R 1A} ) ₃ and a solution of a p-quinone compound are stirred under a temperature condition of room temperature to 80 ° C., and the precipitated yellow-brown crystals are filtered and taken out to obtain phosphine. An addition reaction product of the compound and the p-quinone compound can be obtained. In this case, methanol, a mixed solvent of methanol and water, acetone, a mixed solvent of acetone and toluene and the like can be used as the organic solvent.
As another method, for example, a phosphine compound and a halogen-substituted diphenol compound having two hydroxyl groups substituted on the aromatic ring and a halogen atom substituted on the aromatic ring in the same molecule can be used as a coupling catalyst, if necessary. A method for producing by dehydrohalogenating with a basic compound or the like after reacting by using or irradiating with ultraviolet rays, phosphindihalide compound and halogen substitution. Examples thereof include a method of producing the compound by reacting it with a diphenol compound and then reacting it with dehydrohalogenation.

Next, an acid such as an inorganic acid or an organic acid is added to the obtained addition reaction product to form an intermolecular salt, and then the intermolecular salt and a monovalent or divalent anion represented by ^Xa- The phosphonium compound of the present disclosure can be produced by a method in which an alkali metal salt of the compound which is the source of the above is reacted with heating and stirring in the range of room temperature to 100 ° C. to exchange the anion portion of the intermolecular salt. ..
The obtained phosphonium compound may be purified according to a conventional method.
Specific examples of the acid are not particularly limited as long as it is a Bronsted acid that forms a salt with an addition reaction product produced by reacting a phosphine compound and a p-quinone compound. Examples of the inorganic acid include, but are not limited to, hydrochloric acid, sulfuric acid, nitric acid and the like. Examples of the organic acid include, but are not limited to, oxalic acid, acetic acid, benzoic acid and the like.
A reaction solvent can also be used in forming the intermolecular salt of the addition reaction product and the acid. As a preferable reaction solvent for achieving the reaction between the addition reaction product of the phosphine compound and the p-quinone compound and the alkali metal salt of the compound which is the source of the monovalent or divalent anion represented by ^{Xa-, it is preferable.} The compound is not particularly limited as long as the above reaction can be achieved, and examples thereof include methanol, a methanol / water mixed solvent, and the like.

<Curing accelerator>
The curing accelerators of the present disclosure include the phosphonium compounds of the present disclosure. The curing accelerator of the present disclosure is effective as a component that promotes the curing of the epoxy resin.
In addition to the phosphonium compound of the present disclosure, the curing accelerator of the present disclosure may contain a raw material or solvent used for the synthesis of the phosphonium compound, a by-product generated during the synthesis, and the like.

<Epoxy resin composition>
The phosphonium compound of the present disclosure can be suitably used as a curing accelerator for an epoxy resin.
The epoxy resin composition containing the phosphonium compound of the present disclosure may contain an epoxy resin, the phosphonium compound of the present disclosure, and other components such as a curing agent and an inorganic filler, if necessary.

-Phononium compounds-
The epoxy resin composition contains the phosphonium compound of the present disclosure. The phosphonium compounds of the present disclosure may be used alone or in combination of two or more.
The content of the phosphonium compound in the epoxy resin composition is preferably 0.1% by mass to 20% by mass, preferably 0.5% by mass, based on the total amount of the epoxy resin and the curing agent used if necessary. It is more preferably% to 15% by mass, and further preferably 1.0% by mass to 10% by mass.

-Epoxy resin-
The epoxy resin composition contains an epoxy resin. The type of epoxy resin is not particularly limited, and known epoxy resins can be used.
Specifically, for example, it is selected from the group consisting of phenol compounds (eg, phenol, cresol, xylenol, resorcin, catechol, bisphenol A and bisphenol F) and naphthol compounds (eg, α-naphthol, β-naphthol and dihydroxynaphthalene). Epoxy of novolak resin obtained by condensing or co-condensing at least one of the above with an aldehyde compound (eg, formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde and salicylaldehyde) under an acidic catalyst (eg, phenol). Novolak type epoxy resin and orthocresol novolak type epoxy resin); at least selected from the group consisting of bisphenol (eg, bisphenol A, bisphenol AD, bisphenol F and bisphenol S) and biphenol (eg, alkyl-substituted or unsubstituted biphenol). One diglycidyl ether; an epoxie of a phenol-aralkyl resin; an epoxidate of an adduct or a heavy adduct of a phenol compound and at least one selected from the group consisting of dicyclopentadiene and terpen compounds; polybasic acid ( For example, a glycidyl ester type epoxy resin obtained by the reaction of phthalic acid and dimer acid) and epichlorohydrin; a glycidylamine type epoxy resin obtained by the reaction of polyamine (for example, diaminodiphenylmethane and isocyanuric acid) and epichlorohydrin; Examples include linear aliphatic epoxy resins obtained by oxidation with (for example, peracetic acid); and alicyclic epoxy resins. One type of epoxy resin may be used alone, or two or more types may be used in combination.

From the viewpoint of preventing corrosion of aluminum wiring or copper wiring on an element such as an IC, the purity of the epoxy resin is preferably high, and the amount of hydrolyzable chlorine is preferably small. From the viewpoint of improving the moisture resistance of the epoxy resin composition, the amount of hydrolyzable chlorine is preferably 500 ppm or less on a mass basis.

Here, the amount of hydrolyzable chlorine is a value obtained by dissolving 1 g of the epoxy resin of the sample in 30 ml of dioxane, adding 5 ml of a 1N-KOH methanol solution, refluxing for 30 minutes, and then performing potentiometric titration.

The content of the epoxy resin in the epoxy resin composition is preferably 2.5% by mass to 10% by mass, more preferably 3.0% by mass to 8.0% by mass, and 3.5% by mass. It is more preferably% to 7.5% by mass.
The content of the epoxy resin in the epoxy resin composition excluding the inorganic filler used as needed is preferably 40% by mass to 99% by mass, more preferably 45% by mass to 98% by mass. , 48% by mass to 97% by mass, more preferably.

-Hardener-
The epoxy resin composition may contain a curing agent. The type of curing agent is not particularly limited, and known curing agents can be used.
Specifically, for example, it is selected from the group consisting of phenol compounds (eg, phenol, cresol, xylenol, resorcin, catechol, bisphenol A and bisphenol F) and naphthol compounds (eg, α-naphthol, β-naphthol and dihydroxynaphthalene). A novolak resin obtained by condensing or co-condensing at least one of these compounds with an aldehyde compound (for example, formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde and salicylaldehyde) under an acidic catalyst; phenol-aralkyl resin; biphenyl-aralkyl. Resins; as well as naphthol-aralkyl resins; One type of curing agent may be used alone, or two or more types may be used in combination.

The curing agent is blended so that the equivalent of the functional group (for example, phenolic hydroxyl group in the case of novolak resin) of the curing agent is 0.5 equivalent to 1.5 equivalents with respect to 1 equivalent of the epoxy group of the epoxy resin. In particular, it is preferable that the curing agent is blended so as to have an amount of 0.7 equivalent to 1.2 equivalent.

-Inorganic filler-
The epoxy resin composition may contain an inorganic filler. When the epoxy resin composition contains an inorganic filler, the hygroscopicity of the epoxy resin composition tends to be reduced, and the strength in a cured state tends to be improved.

As the inorganic filler, one type may be used alone, or two or more types may be used in combination.
Examples of the case where two or more kinds of inorganic fillers are used in combination include the case where two or more kinds of inorganic fillers having different components, average particle diameters, shapes and the like are used.
The shape of the inorganic filler is not particularly limited, and examples thereof include a square shape, a powder shape, a spherical shape, and a fibrous shape. From the viewpoint of fluidity during molding and mold wear resistance of the epoxy resin composition, it is preferably spherical.

The inorganic filler preferably contains at least one of alumina and silica, and more preferably contains alumina from the viewpoint of high thermal conductivity. Examples of silica include spherical silica and crystalline silica.
Other inorganic fillers that can be used in combination with at least one of alumina and silica include zircon, magnesium oxide, calcium silicate, calcium carbonate, potassium titanate, silicon carbide, silicon nitride, boron nitride, aluminum nitride, beryllium, zirconia and the like. Can be mentioned. Further, examples of the inorganic filler having a flame-retardant effect include aluminum hydroxide and zinc borate.

The content of the inorganic filler is preferably 50% by volume or more, preferably 70% by volume, based on the entire epoxy resin composition, from the viewpoints of moisture absorption, reduction of linear expansion coefficient, strength improvement and solder heat resistance. The above is more preferable, and 75% by volume or more is further preferable. The content of the inorganic filler may be 95% by volume or less.

When alumina is used, the average particle size of the inorganic filler is preferably 4 μm or more, more preferably 7 μm or more, still more preferably 10 μm or more when alumina is used.
The thermal conductivity of the cured product of the epoxy resin composition tends to increase as the average particle size of the inorganic filler increases.
The average particle size of the inorganic filler is preferably 75 μm or less, more preferably 55 μm or less, and even more preferably 45 μm or less, from the viewpoint of narrow gap filling property.
The average particle size of the inorganic filler can be measured by the following method.

The inorganic filler to be measured is added to the solvent (pure water) together with 1% by mass to 8% by mass of the surfactant in the range of 1% by mass to 5% by mass, and a 110 W ultrasonic cleaner is used for 30 seconds to 5%. Vibrate for minutes to disperse the inorganic filler. About 3 mL of the dispersion is injected into the measurement cell and measured at 25 ° C. The measuring device uses a laser diffraction type particle size distribution meter (HORIBA, Ltd., LA920) to measure the volume-based particle size distribution. The average particle size is obtained as the particle size (D50%) when the accumulation from the small diameter side is 50% in the volume-based particle size distribution.

The specific surface area of the inorganic filler, from the viewpoint of fluidity and moldability, is preferably from ^{0.7m 2 /g~6.0m 2 / g, 0.9m} 2 /g~5.5m 2 / g more preferably, still more preferably 1.0m ² /g~5.0m ² / g.
The fluidity of the epoxy resin composition tends to increase as the specific surface area of the inorganic filler decreases.
In the present disclosure, the specific surface area of the inorganic filler refers to the specific surface area of the mixture of the inorganic filler when at least two kinds of inorganic fillers are used in combination.
The specific surface area (BET specific surface area) of the inorganic filler can be measured from the nitrogen adsorption capacity according to JIS Z 8830: 2013. As the evaluation device, QUANTACHROME: AUTOSORB-1 (trade name) can be used. Since it is considered that the water adsorbed on the sample surface and the structure affects the gas adsorption capacity, it is preferable to first perform a pretreatment for removing water by heating when measuring the BET specific surface area. ..
In the pretreatment, the measurement cell in which 0.05 g of the measurement sample is charged is decompressed to 10 Pa or less with a vacuum pump, heated at 110 ° C., held for 3 hours or more, and then kept at room temperature (reduced pressure). Naturally cool to 25 ° C.). After this pretreatment, the evaluation temperature is set to 77K, and the evaluation pressure range is measured as a relative pressure (equilibrium pressure with respect to saturated vapor pressure) of less than 1.

-Curing accelerator-
The epoxy resin composition may further contain other curing accelerators other than the phosphonium compounds of the present disclosure. The types of other curing accelerators are not particularly limited, and known curing accelerators can be used.
Specifically, 1,8-diaza-bicyclo [5.4.0] undecene-7, 1,5-diaza-bicyclo [4.3.0] nonene, 5,6-dibutylamino-1,8- Diaza-bicyclo [5.4.0] Undecene-7 and other cycloamidine compounds, cycloamidine compounds with maleic anhydride, 1,4-benzoquinone, 2,5-turquinone, 1,4-naphthoquinone, 2,3-dimethyl Kinone compounds such as benzoquinone, 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, phenyl-1,4-benzoquinone, diazo Compounds with intramolecular polarization formed by adding compounds with π bonds such as phenylmethane and phenol resin, tertiary amine compounds such as benzyldimethylamine, triethanolamine, dimethylaminoethanol and tris (dimethylaminomethyl) phenol, Derivatives of tertiary amine compounds, imidazole compounds such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, derivatives of imidazole compounds, tetraphenylphosphonium tetraphenylborate, triphenylphosphonium tetraphenylborate, 2 -Ethyl-4-methylimidazolium tetraphenylborate, tetraphenylborate salt such as N-methylmorpholinium tetraphenylborate, derivative of tetraphenylborate salt, triphenylphosphine-triphenylborane complex, morpholin-triphenylborane complex Such as triphenylboran complex and the like. As the curing accelerator, one type may be used alone, or two or more types may be used in combination.

The content of the curing accelerator is preferably 0.1% by mass to 20% by mass with respect to the total amount of the epoxy resin and the curing agent used as needed.

(Ion trap agent)
The epoxy resin composition may further contain an ion trap agent.
The ion trap agent that can be used in the present disclosure is not particularly limited as long as it is an ion trap agent that is generally used in a sealing material used for manufacturing semiconductor devices. Examples of the ion trapping agent include compounds represented by the following general formula (VI-1) or the following general formula (VI-2).

Mg _1-a Al _a (OH) ₂ (CO ₃ ) _{a / 2} · uH ₂ O (VI-1)
(In the general formula (VI-1), a is 0 <a≤0.5 and u is a positive number.)
BiO _b (OH) _c (NO ₃ ) _d (VI-2)
(In the general formula (VI-2), b is 0.9 ≦ b ≦ 1.1, c is 0.6 ≦ c ≦ 0.8, and d is 0.2 ≦ d ≦ 0.4.)

The ion trap agent is available as a commercial product. As a compound represented by the general formula (VI-1), for example, "DHT-4A" (Kyowa Chemical Industry Co., Ltd., trade name) is available as a commercially available product. Further, as a compound represented by the general formula (VI-2), for example, "IXE500" (Toagosei Co., Ltd., trade name) is available as a commercially available product.

Examples of ion trapping agents other than the above include hydrous oxides of elements selected from magnesium, aluminum, titanium, zirconium, antimony and the like.
One type of ion trapping agent may be used alone, or two or more types may be used in combination.

When the epoxy resin composition contains an ion trapping agent, the content of the ion trapping agent is preferably 1 part by mass or more with respect to 100 parts by mass of the epoxy resin from the viewpoint of realizing sufficient moisture resistance reliability. .. From the viewpoint of fully exerting the effects of the other components, the content of the ion trap agent is preferably 15 parts by mass or less with respect to 100 parts by mass of the epoxy resin.

The average particle size of the ion trap agent is preferably 0.1 μm to 3.0 μm, and the maximum particle size is preferably 10 μm or less. The average particle size of the ion trap agent can be measured in the same manner as in the case of the inorganic filler.

(Coupling agent)
The epoxy resin composition may further contain a coupling agent. The type of the coupling agent is not particularly limited, and a known coupling agent can be used. Examples of the coupling agent include a silane coupling agent and a titanium coupling agent. One type of coupling agent may be used alone, or two or more types may be used in combination.

Examples of the silane coupling agent include vinyltrichlorosilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane. , Γ-Glysidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ- [bis (β-hydroxyethyl)] aminopropyltriethoxysilane, N -(Β-Aminoethyl) -γ-aminopropyltrimethoxysilane, γ- (β-aminoethylamino) propyldimethoxymethylsilane, N- (dimethoxymethylsilylisopropyl) ethylenediamine, methyltrimethoxysilane, methyltriethoxysilane, N- (β- (N-vinylbenzylamino) ethyl) -γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, hexamethyldisilane, γ-anilinopropyltrimethoxysilane, vinyltrimethoxysilane and γ − Mercaptopropylmethyldimethoxysilane.

Examples of the titanium coupling agent include isopropyltriisostearoyl titanate, isopropyltris (dioctylpyrophosphate) titanate, isopropyltri (N-aminoethyl-aminoethyl) titanate, tetraoctylbis (ditridecylphosphite) titanate, and tetra (ditridecylphosphite) titanate. 2,2-Diallyloxymethyl-1-butyl) bis (ditridecylphosphite) titanate, bis (dioctylpyrophosphate) oxyacetate titanate, bis (dioctylpyrophosphate) ethylene titanate, isopropyltrioctanoyl titanate, isopropyldimethacrylic iso Examples thereof include stearoyl titanate, isopropyltridodecylbenzenesulfonyl titanate, isopropylisostearoyl diacrylic titanate, isopropyltri (dioctyl phosphate) titanate, isopropyltricylphenyl titanate and tetraisopropylbis (dioctyl phosphate) titanate.

When the epoxy resin composition contains a coupling agent, the content of the coupling agent is preferably 10% by mass or less with respect to the entire epoxy resin composition, and from the viewpoint of exerting the effect, it is 0. It is preferably 1% by mass or more.

(Release agent)
The epoxy resin composition may further contain a mold release agent. The type of release agent is not particularly limited, and a known release agent can be used. Specific examples thereof include higher fatty acids, carnauba wax and polyethylene wax. As the release agent, one type may be used alone, or two or more types may be used in combination.
When the epoxy resin composition contains a mold release agent, the content of the mold release agent is preferably 10% by mass or less with respect to the total amount of the epoxy resin and the curing agent, and from the viewpoint of exerting the effect. Is preferably 0.5% by mass or more.

(Colorants and modifiers)
The epoxy resin composition may contain a colorant (eg, carbon black). Moreover, the epoxy resin composition may contain a modifier (for example, silicone and silicone rubber). As the colorant and the modifier, one type may be used alone, or two or more types may be used in combination.

When conductive particles such as carbon black are used as the colorant, the conductive particles preferably have a particle size of 10 μm or more and a content of 1% by mass or less.
When the epoxy resin composition contains conductive particles, the content of the conductive particles is preferably 3% by mass or less with respect to the total amount of the epoxy resin and the curing agent.

<Method for producing epoxy resin composition>
The method for producing the epoxy resin composition is not particularly limited, and a known method can be used. For example, it can be produced by sufficiently mixing a mixture of raw materials in a predetermined blending amount with a mixer or the like, kneading the mixture with a hot roll, an extruder or the like, cooling, pulverizing or the like. The state of the epoxy resin composition is not particularly limited and may be in the form of powder, solid, liquid or the like.

Hereinafter, the present invention will be described based on examples, but the present invention is not limited thereto. In the following examples,% indicates mass% unless otherwise specified.

[ ^{1 1} H-NMR measurement]
10 mg of crystals were dissolved in about 0.5 ml of heavy DMSO (dimethyl sulfoxide), placed in a sample tube of φ5 mm, and ¹ H-NMR spectrum was measured with JNM-ECS400 manufactured by JEOL RESONANCE Co., Ltd. The shift value was based on DMSO (δ = 2.49 ppm).
[IR measurement]
The IR spectrum was measured by the ATR method using ALPHA manufactured by Bruker Optex Co., Ltd.

[Example 1]
104 g of 35% hydrochloric acid was added dropwise over 30 minutes to a slurry in which 370 g of an addition reaction product of triphenylphosphine and 1,4-benzoquinone synthesized by the method described in JP-A-9-157497 was suspended in 2000 mL of methanol. Then, 2000 mL of water and 204 g of potassium hydrogen phthalate were added, and the mixture was heated and stirred at 80 ° C. for 1 hour. After cooling the reaction solution to 10 ° C., the precipitated crystals were filtered and washed twice with 1000 mL of purified water.
To the obtained crude crystals, 1200 mL each of methanol and purified water were added, and the mixture was heated and stirred at 80 ° C. for 1 hour. After cooling the reaction solution to 10 ° C., the precipitated crystals were filtered and washed twice with 1000 mL of purified water. The obtained crystals were dried under reduced pressure to obtain 387 g (yield 72.1%) of 2,5-dihydroxyphenyl (triphenyl) phosphonium hydrogen phthalate (phosphonium compound 1). The melting point of the phosphonium compound 1 was 206 ° C.
For phosphonium compound 1, ^{1 1} H-NMR measurement was carried out. The measurement results are as follows. In addition, the ¹ H-NMR spectrum is shown in FIG. 1 and the IR spectrum is shown in FIG.

^{1 1} H-NMR: 20.35 ppm (1H, br), 10.97 ppm (1H, br), 9.57 ppm (1H, br), 8.20 ppm to 8.10 ppm (2H, dd), 7.93 ppm to 7 .82ppm (3H, t), 7.80ppm-7.60ppm (12H, m), 7.52ppm-743ppm (2H, dd), 7.23ppm-7.15ppm (1H, m), 7.03ppm ~ 6.89ppm (1H, m), 6.38ppm ~ 6.25ppm (1H, m)

[Example 2]
35% hydrochloric acid was added to a slurry in which 310 g of an addition reaction product of tri-n-butylphosphine and 1,4-benzoquinone, which was synthesized by the same method as described in JP-A-9-157497, was suspended in 1250 mL of methanol. 104 g was added dropwise over 30 minutes, then 1250 mL of water and 204 g of potassium hydrogen phthalate were added, and the mixture was heated and stirred at 80 ° C. for 1 hour. After adding 1250 mL of water to the reaction solution, methanol was distilled off by concentration under reduced pressure, 1250 mL of toluene was added and the mixture was cooled to 10 ° C., and the precipitated crystals were filtered and washed twice with 1000 mL of purified water.
To the obtained crude crystals, 400 mL of methanol and 800 mL of purified water were added, and the mixture was heated and stirred at 80 ° C. for 1 hour. After adding 1250 mL of toluene to the reaction solution, methanol was distilled off by concentration under reduced pressure, the mixture was cooled to 10 ° C., the precipitated crystals were filtered, and the mixture was washed twice with 1000 mL of purified water. The obtained crystals were dried under reduced pressure to obtain 404 g (yield 84.8%) of 2,5-dihydroxyphenyl (tri-n-butyl) phosphonium hydrogen phthalate (phosphonium compound 2). The melting point of the phosphonium compound 2 was 132 ° C.
For phosphonium compound 2, ^{1 1} H-NMR measurement was carried out. The measurement results are as follows.

^{1 1} H-NMR: 20.57 ppm (1H, br), 10.73 ppm (1H, br), 9.59 ppm (1H, br), 8.25 ppm to 8.15 ppm (2H, dd), 7.58 ppm to 7 .47ppm (2H, dd), 7.13ppm to 7.05ppm (1H, m), 7.00ppm to 6.85ppm (2H, m), 2.62ppm to 2.42ppm (6H, m), 1.55ppm ~ 1.32ppm (12H, m), 1.00ppm ~ 0.80ppm (9H, t)

[Example 3]
218 g of pyromellitic anhydride was added to an aqueous solution prepared by dissolving 132 g of potassium hydroxide having a purity of 85% in 4000 mL of water, and the mixture was heated and stirred at 60 ° C. for 30 minutes to obtain an aqueous solution of dipotassium pyromellitic acid.
208 g of 35% hydrochloric acid was added dropwise over 30 minutes to a slurry in which 740 g of an addition reaction product of triphenylphosphine and 1,4-benzoquinone was suspended in 4000 mL of methanol, and then an aqueous solution of dipotassium pyromellitic acid was added at 80 ° C. The mixture was heated and stirred for 1 hour. Methanol was distilled off from the reaction solution by concentration under reduced pressure, the mixture was cooled to 10 ° C., the precipitated crystals were filtered, and the mixture was washed twice with 3000 mL of purified water. The obtained crystals were dried under reduced pressure to obtain 876 g (yield 88.0%) of bis [2,5-dihydroxyphenyl (triphenyl) phosphonium] dihydrogen pyromerite (phosphonium compound 3). The melting point of the phosphonium compound 3 was 260 ° C.
For phosphonium compound 3, ^{1 1} H-NMR measurement was carried out. The measurement results are as follows.

^{1 1} H-NMR: 20.65 ppm (2H, br), 10.89 ppm (2H, br), 9.56 ppm (2H, br), 8.93 ppm (2H, s), 7.93 ppm to 7.82 ppm (6H) , T), 7.81ppm to 7.61ppm (24H, m), 7.23ppm to 7.15ppm (2H, m), 7.03ppm to 6.89ppm (2H, m), 6.38ppm to 6.25ppm (2H, m)

-Storage stability-
The epoxy resin composition was placed in a sealed bag and left in a high temperature and high humidity device in a 25 ° C. and 50% RH environment for 168 hours. We investigated how much the viscosity change with time increased from the initial value. ^{The shear rate was investigated at 175 ° C. and 100s -1} in consideration of the actual molding conditions, and is shown in Table 1.
-Curability-
For the curability, a value measured using a Shore D hardness tester when the epoxy resin composition was molded under the conditions of 175 ° C., 90 sec, and a pressure of 7 MPa was used.

The details of the materials shown in Table 1 are as follows. In Table 1, "-" means that the corresponding material was not used.
〔Epoxy resin〕
・ NC-3000 (trade name, manufactured by Nippon Kayaku Co., Ltd.)
[Curing agent]
・ MEHC-7851SS (trade name, manufactured by Meiwa Kasei Co., Ltd.)
[Curing accelerator]
・ Curing accelerator A ・ ・ ・ 2,5-dihydroxyphenyl (triphenyl) phosphonium hydrogenphthalate ・ Curing accelerator B ・ ・ ・ triphenylphosphine-benzoquinone adduct ・ Curing accelerator C ・ ・ ・ tripalatrilphosphine-benzoquinone Accretionary prism / curing accelerator D ... Tri-n-butylphosphine-benzoquinone adduct [silane compound]
・ KBM-403 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.)
[Pigment]
・ MA600MJ (trade name, manufactured by Mitsubishi Chemical Corporation)
〔Additive〕
・ DHT-4A (trade name, manufactured by Kyowa Chemical Industry Co., Ltd.)
[Inorganic filler]
-Silica particles A ... Silica particles having an average particle diameter of 0.5 μm-Silica particles B ... Silica particles having an average particle diameter of 10 μm

Claims (2)

A phosphonium compound represented by the following general formula (I).

(In general formula (I), R ^1A each independently represents a substituted or unsubstituted hydrocarbon group having 1 to 18 carbon atoms. Two R ^1A arbitrarily selected from three R ^1A are linked to each other. Then, a cyclic structure may be formed together with the phosphorus atom ^{to which R 1A is bonded. R 1B} each independently represents a substituted or unsubstituted hydrocarbon group having 1 to 18 carbon atoms. N is 0 to 0. Indicates an integer of 3. If n is 2 or 3, the two ^R1Bs may be connected to each other to form a cyclic structure. A indicates 1 or 2. If a is 1, X ^{a. −} Indicates a monovalent anion represented by the following general formula (IA), and when a is 2, X a ⁻ represents a divalent anion represented by the following general formula (IB). )

(In the general formula (IA), R ^1C independently represents an alkyl group, a hydroxyl group, an amino group or an alkoxy group. P represents an integer of 0 to 4. In the general formula (IB), R ^1D represents. , Each independently indicates an alkyl group, a hydroxyl group, an amino group or an alkoxy group. Q indicates an integer of 0 to 2.) A curing accelerator containing the phosphonium compound according to claim 1.

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