JP2000319361A - Thermosetting resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermosetting resin composition for reconciling high curing properties and storage stability, useful in the field of electric and electronic materials. SOLUTION: This composition comprises a compound (A) containing two or more epoxy groups in one molecule, a compound (B) containing two or more phenolic hydroxyl groups in one molecule and a compound (C) having a molecular association structure composed of one molecule of tetraphenylphosphonium (X) and 2-2.5 molecules of a compound (Y) containing two phenolic hydroxyl groups in one molecule in which the compound (Y) is composed of a phenoxide type compound in which one of the phenolic hydroxyl group is a conjugate base as essential components.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosetting resin composition having good curability and storage stability and useful in the field of electric and electronic materials.

[0002]

2. Description of the Related Art In recent years, electric and electronic materials, especially IC encapsulating materials, are required to have fast curability for the purpose of improving production efficiency and to improve storability for improving handling during distribution and storage. It is becoming.

[0003] Conventionally, epoxy resins for the electronic and electric fields have used amines, imidazole compounds, and the like as curing catalysts.
Various compounds such as nitrogen-containing heterocyclic compounds such as diazabicycloundecene and quaternary ammonium, phosphonium or arsonium compounds have been used.

[0004] These commonly used curing catalysts often exhibit a curing promoting action even at a relatively low temperature such as room temperature. This causes a decrease in quality as a product, such as an increase in viscosity during production and storage of the resin composition, a decrease in fluidity, and a variation in curability.

In order to solve this problem, research on so-called latent curing accelerators has recently been made which suppresses the time-dependent changes in viscosity and fluidity at low temperatures and causes a curing reaction only by heating during shaping and molding. It is being prospered. As a means for protecting the active site of the curing accelerator with an ion pair, studies have been made to develop latentness.
No. 41290 discloses a latent curing accelerator having a salt structure of various organic acids and phosphonium ions. However, this phosphonium salt does not have a specific higher-order molecular structure, and the ion pair is relatively easily affected by the external environment. Therefore, in recent years, semiconductor encapsulants using low-molecular epoxy resins or phenol aralkyl resins have However, there is a problem that storage stability is reduced.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermosetting resin composition which is compatible with the field of electric and electronic materials and has both fast curing properties and storage stability. is there.

[0007]

That is, the present invention provides a compound (A) having two or more epoxy groups in one molecule, a compound (B) having two or more phenolic hydroxyl groups in one molecule, Phenylphosphonium (X)
It has a structure of a molecular aggregate formed by one molecule and 2 to 2.5 molecules of a compound (Y) having two phenolic hydroxyl groups in one molecule, and in the structure, the compound (Y) Relates to a thermosetting resin composition comprising, as an essential component, a molecular compound (C) comprising a phenoxide-type compound in which one of the phenolic hydroxyl groups is a conjugate base, and has a reaction activity as a curing accelerator. The present inventors have found that a composition having extremely excellent curability and preservability can be obtained by utilizing the structure of a molecular compound having a protected point, and have completed the present invention.

[0008]

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a compound (A) having two or more epoxy groups in one molecule, a compound (B) having two or more phenolic hydroxyl groups in one molecule, and tetraphenylphosphonium tetra It is obtained by reacting phenyl borate (Z) (hereinafter abbreviated as borate (Z)) with compound (Y) having two phenolic hydroxyl groups in one molecule (hereinafter abbreviated as compound (Y)). Of one molecule of tetraphenylphosphonium (X) and two compounds (Y) having two phenolic hydroxyl groups per molecule.
And a compound (Y) having a structure of a molecular association formed with 2.5 molecules, and in the structure, the compound (Y) is a molecular compound (C) comprising a phenoxide-type compound in which one of its phenolic hydroxyl groups is a conjugate base. ) Is blended with the thermosetting resin composition to obtain extremely excellent curability and storage stability.

The compound (A) having two or more epoxy groups in one molecule used in the present invention is not particularly limited as long as it has two or more epoxy groups in one molecule. Novolak-type epoxy resins, naphthalene-type epoxy resins, phenols such as biphenols, phenolic resins, epoxy resins produced by reacting epichlorohydrin with hydroxyl groups such as naphthols, and alicyclic epoxy resins. Epoxy resins obtained by oxidizing olefins with a peracid and epoxidized, and those obtained by epoxidizing dihydroxybenzenes such as hydroquinone with epichlorohydrin are also included.

The compound (B) having two or more phenolic hydroxyl groups in one molecule used in the present invention acts as a curing agent for the compound (A) having two or more epoxy groups in one molecule. Specific examples include a phenol novolak resin, a cresol novolak resin, an alkyl-modified novolak resin, a phenol aralkyl resin, and a resin obtained by co-condensing a naphthol and a phenol with a carbonyl group-containing compound. Any compound may be used as long as two or more hydrogen atoms bonded to the sex ring are substituted with a hydroxyl group.

The compound (Y) to be reacted with borate (Z) for synthesizing molecular compound (C) used in the present invention is a compound represented by formula (1), bis (4)
-Hydroxy-3,5-dimethylphenyl) methane (commonly known as tetramethylbisphenol F), 4,4'-sulfonyldiphenol and 4,4 'represented by the formula (2)
-Isopropylidene diphenol (commonly known as bisphenol A), bis (4-hydroxyphenyl) methane, bis (2-hydroxyphenyl) methane, (2-hydroxyphenyl) (4-hydroxyphenyl) methane and, among these, bis (4-hydroxyphenyl) methane Hydroxyphenyl) methane, bis (2-hydroxyphenyl) methane, and (2-hydroxyphenyl) (4-hydroxyphenyl) methane (for example, bisphenol F-
Bisphenols such as D), dihydroxybenzenes such as 1,2-benzenediol, 1,3-benzenediol and 1,4-benzenediol, and various isomers of dihydroxynaphthalenes such as 1,6-dihydroxynaphthalene; And various isomers of biphenols such as 2,2′-biphenol and 4,4′-biphenol. In the present invention, borate (Z) and compound (Y)
The compound (Y) is desirably selected from the group consisting of compounds represented by the formula (2) in terms of reactivity and workability in the synthesis method for obtaining the molecular compound (C) by the reaction with

[0012]

Embedded image

[0013]

Embedded image In the formula, R represents CH ₂ or C (CH ₃ ) ₂ .

Particularly important techniques in the present invention include a synthesis method for obtaining a specific molecular compound by a reaction between borate (Z) and the above-mentioned compound (Y), and a resulting molecular compound having a specific molar ratio ( C).

The method for synthesizing the molecular compound (C) includes tetraphenylphosphonium tetraphenylborate (Z),
After reacting the compound (Y) having two phenolic hydroxyl groups in one molecule with a molar ratio of Z: Y = 1: 2 to 4, and further performing a thermal reaction in a solvent having a boiling point of 60 ° C. or more. It is performed by

The preceding stage of the reaction in the synthesis of molecular compound (C) is a reaction involving a substitution reaction on boron. The phenolic hydroxyl group of compound (Y) is deeply involved in this substitution reaction, and the molar ratio of borate (Z) having four substituents on boron to compound (Y) having two phenolic hydroxyl groups is present. Is uniquely determined. Specifically, there are two cases, in which both two phenolic hydroxyl groups in one molecule can participate in the reaction, and when only one of them can participate in the reaction, and the corresponding borate (Z) and compound The molar ratio of (Y) is Z: Y =
1: 2 and 1: 4.

If the molar ratio of the compound (Y) to the borate (Z) is less than 1: 2, for example, the hydroxyl group required for the reaction is insufficient, and the substitution reaction on boron is sufficiently performed. Therefore, the thermal reaction in the latter solvent may not be performed sufficiently. When the molar ratio of the compound (Y) to the borate (Z) exceeds 1: 4, the excessively added compound (Y) cannot be completely removed, and the molecular compound (C)
Is considered to degrade the characteristics of. In fact, in the present invention,
It has been confirmed by the inventors that the reaction is optimally performed by setting the molar ratio of the borate (Z) and the compound (Y) within this range. This reaction can be monitored by the amount of benzene generated when the phenyl group on the boron is replaced by a phenolic hydroxyl group, and the reaction is usually sufficient if 80% by weight or more of benzene is generated based on the theoretical amount generated. Progressing.

The solvent used in the thermal reaction in the solvent at the latter stage in the synthesis of the molecular compound (C) is not particularly limited as long as it has a boiling point of 60 ° C. or higher.
Solvents having at least one hydroxyl group in the molecule and having a boiling point of 60 ° C. or higher are preferred, and alcohol solvents that are usually used, such as methanol, ethanol, propanol and butanol, are particularly preferred.

The thermal reaction time in the solvent is desirably 1 hour or more. However, the thermal reaction does not necessarily have to be a reflux reaction, and may be carried out under conditions that allow heating to substantially 60 ° C. or more. It does not need to be refluxed. Under the conditions described above, in this process, the reaction product is sufficiently diffused into the solvent, and components derived from boron and an extra component (Y) are removed to form a molecular compound (C).

It is also possible that the solubility is temporarily increased by heating the alcoholic solvent to dissolve the insoluble matter and then re-precipitate the desired molecular compound (C) by cooling again. This is an excellent point of this condition.

The compound (Y) contained in the molecular compound (C) used in the present invention is a mixture with a compound of a conjugate base type in which a phenolic hydroxyl group is converted to a phenolate. From the result of analysis by the neutralization titration in C), it is considered to be equal to the number of moles of phosphonium. That is, compound (Y) is 2.0 to 2.5 moles per 1 mole of phosphonium, and one of the phenolic hydroxyl groups is considered to be a phenoxide-type compound that is a conjugate base.

As described above, the molecular compound (C) used in the present invention has a phosphonium-phenoxide type salt in its structure, which is different from the conventional phosphonium-organic acid anion salt type compound in the present invention. The molecular compound (C) used in the present invention is characterized in that a higher-order structure due to a hydrogen bond surrounds this ionic bond. In the salt of the prior art, the reactivity was controlled only by the strength of the ionic bond. On the other hand, in the molecular compound (C) used in the present invention, the enclosing by the higher order structure of the anion at room temperature protected the active site. On the other hand, in the actual shaping stage, the active sites are exposed due to the collapse of the higher-order structure, and so-called latency, which expresses reactivity, is imparted.

The ratio of the compound (A) having two or more epoxy groups in one molecule to the compound (B) having two or more phenolic hydroxyl groups in one molecule, which functions as a curing agent, used in the present invention is as follows. And phenolic hydroxyl groups in an amount of 0.5 to 2 mol, preferably 0.1 to 2 mol, per mol of epoxy group.
When used in a molar ratio of about 8 to 1.2, the curability, heat resistance, electrical characteristics, and the like are further improved. The molecular compound (C), which functions as a curing accelerator, has a weight of 0.5 when the total weight of the compounds (A) and (B) is 100.
About 20 parts by weight is preferable because the curability, storage stability and other properties are well balanced.

The thermosetting resin composition of the present invention may be combined with additives known to those skilled in the art, such as an inorganic filler, a release agent, and a coupling agent, and auxiliary materials, if necessary. When the thermosetting resin composition of the present invention is used for an epoxy resin sealing material, the inorganic filler is a compound (A),
When the total weight of (B) is 100, 100 to 240
About 0 parts by weight, 0.1 to 2 parts of the release agent and the coupling agent
About 0 parts by weight is suitable.

The resin composition of the present invention can be produced by mixing and heating and kneading the above components using a heating kneader, an extruder, a hot roll or the like.

[0026]

Embodiments of the present invention will be described below, but the present invention is not limited by these embodiments.

First, a molecular compound (C) serving as a curing accelerator is synthesized from the borate (Z) and the phenol compound (Y), and then the obtained molecular compound (C) is converted into an epoxy group in one molecule. (A) having two or more phenolic hydroxyl groups in one molecule (B) is added to a compound (A) having two or more phenolic hydroxyl groups in a molecule, and the mixture is pulverized and mixed. Thus, a sample of the composition was prepared.
For property evaluation, the curing torque was measured by a curast meter and the residual rate of curing heat generation was measured by differential scanning calorimetry (DSC). The evaluation method is as follows.

1. Curing Torque Using a resin composition prepared by the sample preparation method described above, a curast meter (JS
R Curastometer PS type), 175 ° C, 45
The torque after seconds was determined. Torque in a curast meter is a parameter of curability, and a larger value indicates higher curability.

2. Residual Curing Calorific Value (Evaluation of Preservability) Using the resin composition prepared by the sample preparation method described above, the initial curing calorific value immediately after preparation and the curing calorific value after storage treatment at 40 ° C. for 3 days were measured. Curing heat value (mj) after preservation treatment relative to initial curing heat value (mj / mg)
/ Mg) was calculated. In addition, the measurement of the calorific value of the curing was performed by differential thermal analysis under a condition of a heating rate of 10 ° C./min. A larger value indicates better storage stability.

3. Neutralization determination To evaluate the active group equivalent of the curing accelerator, the alkali equivalent of the synthesized molecular compound (C) was measured using oxalic acid and sodium hydroxide in a methanol / water-based solvent. Specifically, the molecular compound (C) is reacted with an excess of oxalic acid having a known weight, and the remaining oxalic acid is quantified with an aqueous sodium hydroxide solution having a normality, and the normality per weight of the molecular compound (C) is determined. N / g) was calculated. The reciprocal of this value is the phosphonium phenoxide equivalent.

4. Determination of composition ratio In order to obtain the composition ratio of tetraphenylphosphonium (X) and compound (Y) containing a conjugate base type in the synthesized molecular compound (C), ¹ H-NMR measurement was performed in a heavy methanol solvent, The area of the phenyl proton of tetraphenylphosphonium and the area of the phenyl proton of the compound (Y) containing a conjugate base were calculated. Using this value, the composition ratio (X / Y) of the components can be calculated.

[Synthesis of Curing Accelerator] (Synthesis Example 1) 300.3 g (1.5 mol) of bisphenol FD (corresponding to compound (Y)) manufactured by Honshu Chemical Industry Co., Ltd., and tetraphenylphosphonium tetraphenylborate (Z ) 325.6 g (0.5 mol) were charged into a 3 L separable flask and reacted at 200 ° C. for 3 hours. The amount of benzene distilled in this reaction was 97 wt% of the theoretical amount.
(That is, the benzene distillation rate was 97%). The crude product resulting from this reaction is finely pulverized, charged into a separable flask, 2-propanol is added in an amount three times the charged weight of the crude product, and the mixture is heated at an internal temperature of 82.4 ° C. (boiling point temperature of 2-propanol) to 1.5 times. Allowed to stir for hours. Thereafter, most of the 2-propanol was removed, and low-boiling components were further removed under reduced pressure by heating. The obtained product is referred to as compound C1. ¹ C1 of H-
The NMR data is shown in FIG. The measurement solvent was heavy methyl alcohol, and the peaks around 4.8 ppm and 3.3 ppm were the peaks of the solvent. Here, 6.4 ~
The peak group around 7.1 ppm is assigned to the phenyl proton of bisphenol F as the raw material, and the peak group around 7.6 to 8.0 ppm is assigned to the phenyl proton of the tetraphenylphosphonium group, and the molecular compound ( In C), the molar ratio of tetraphenylphosphonium (X) and the compound (Y) containing a conjugated base type is such that X / Y = 1 /
It can be calculated to be 2.2.

(Synthesis Examples 2 to 9) In Synthesis Examples 2 to 9, Table 1
Under the conditions shown in (1), all the basic operations were performed in the same manner as in Synthesis Example 1 to prepare compounds C2 to C9, respectively.

(Comparative Synthesis Example 1) Sodium benzoate 7
2.05 g (0.5 mol) dissolved in 200 g of methanol was stirred at room temperature, and 209.6 g (0.5 mol) of tetraphenylphosphonium bromide was dissolved in methanol 2
What was dissolved in 00 g was dropped into this. After the dropwise addition, the solution was heated to redissolve the precipitate, and 150 g of pure water was added thereto to obtain a precipitate. The precipitate was filtered by suction, rinsed several times with pure water, and dried in a vacuum dryer at 80 ° C. for 2 hours to obtain Comparative Synthetic Product D.

[0035]

[Table 1]

[Preparation of Samples of Composition] (Examples 1 to 9 and Comparative Examples 1 and 2) Samples of the composition were prepared according to the formulations shown in Table 2 by the method described above and evaluated. In Comparative Example 1, triphenylphosphine was used instead of the compound (C) in Example, and in Comparative Example 2, the compound (D) synthesized in Comparative Synthesis Example 1 was used. The evaluation results of the obtained compositions were as shown in Table 2.

[0037]

[Table 2]

As is clear from the evaluation results of the examples shown in Table 2, the thermosetting resin composition of the present invention has excellent curability and storage stability, whereas the thermosetting resin composition of Comparative Example 1 Triphenylphosphine, which is a curing accelerator, is clearly inferior in curability and storage stability. In Comparative Example 2, tetraphenylphosphonium (X) and a monofunctional organic acid (OA)
X: OA = 1: 1: 1 molar ratio of a salt,
Although the curability is somewhat high, the storage stability is very poor like triphenylphosphine. From this, it can be seen that the molecular compound (C) of the present invention is much more excellent in curability and storage stability than the conventional curing accelerator.

[0039]

The thermosetting resin composition of the present invention has excellent curability and preservability, and when used as a sealing material for electric / electronic parts, improves the production efficiency and the handling property during distribution and storage. And is useful as a material that can respond to recent demands in the field of electric and electronic materials.

[Brief description of the drawings]

[1] ¹ of the compound C1 obtained in Synthesis Example 1 H-NM
It is an R chart.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Nagata 2-5-8 Higashishinagawa, Shinagawa-ku, Tokyo Sumitomo Bakelite Co., Ltd. (72) Akiko Okubo 2-5-2-8 Higashishinagawa, Shinagawa-ku, Tokyo Sumitomo Bakelite Co., Ltd. F-term (reference) 4J036 AA01 DA04 FB07 GA04 GA06 GA29 JA07

Claims (4)

[Claims] 1. A compound (A) having two or more epoxy groups in one molecule, a compound (B) having two or more phenolic hydroxyl groups in one molecule, and one molecule of tetraphenylphosphonium (X), The compound (Y) having two phenolic hydroxyl groups in one molecule has a structure of a molecular aggregate formed by 2 to 2.5 molecules, and the compound (Y) has the phenolic property in the structure. A thermosetting resin composition comprising, as an essential component, a molecular compound (C) comprising a phenoxide-type compound in which one of the hydroxyl groups is a conjugate base. 2. The method according to claim 1, wherein the molecular compound (C) is tetraphenylphosphonium tetraphenylborate (Z).
And a compound (Y) having two phenolic hydroxyl groups in one molecule in a molar ratio of Z: Y = 1: 2 to 4, and further subjected to a thermal reaction in a solvent having a boiling point of 60 ° C. or higher. 2. The thermosetting resin composition according to claim 1, wherein the thermosetting resin composition is synthesized by allowing the composition to be synthesized. 3. A compound (Y) having two phenolic hydroxyl groups in one molecule, the group consisting of dihydroxybenzenes, bisphenols, biphenols, dihydroxynaphthalenes, and a compound represented by the formula (1). The thermosetting resin composition according to claim 1, wherein the thermosetting resin composition is at least one selected from the group consisting of: Embedded image 4. The thermosetting resin composition according to claim 3, wherein the bisphenol is at least one selected from the group consisting of compounds represented by the formula (2). Embedded image In the formula, R represents CH ₂ or C (CH ₃ ) ₂ .