JP2000256442A - Themosetting resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition excellent in rapid hardening and storage stability by using as essential components a compound having not less than two epoxy groups, a compound having not less than two phenolic hydroxyl groups and a compound obtained by reacting tetraphenylphosphoniumtetraphenyl borate with bis(hydroxyphenyl)methane. SOLUTION: Tetraphenylphosphoniumtetraphenyl borate (X) is reacted with a compound (Y) represented by formula (substitution position of a hydroxyl group is ortho or para with respect to methylene) at a temp. of 150-230 deg.C for not less than 1 hour, the ratio of X to Y being 1 to 2-4. Further the reaction is continued in a solvent having a boiling point of not less than 60 deg.C to produce a compound (C) having a boron content of not more than 0.6 wt.%. A thermosetting resin composition is obtained by mixing as essential components a compound (A) having not less than two epoxy groups in a molecule, a compound (B) having not less than two phenolic hydroxyl groups in a molecule and a compound (C).

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] In order to meet such demands, the present inventors have made intensive studies to improve curability and preservability, and as a result, tetraphenylphosphonium tetraphenylborate (X) is represented by the following general formula (1). The compound (Y) having a specific structure is thermally reacted at a specific ratio, and the reaction is further promoted in a solvent to use a compound having a boron content of 0.6 wt% or less as a curing accelerator. It has been found that a thermosetting resin composition having the above properties can be obtained.

The most important technique in the present invention is to carry out a thermal reaction in a molar ratio of borate (X) to compound (Y) in the range of 1: 2 to 4, and further, in a solvent having a boiling point of 60 ° C. or more. By promoting the reaction, a compound having an excellent curing promoting action is obtained. The difference between the technology of the present invention and the conventional technology will be described below.

[0005] JP-B-56-45491 discloses a curing agent obtained by heat-treating a novolak-type phenol resin having a specified molecular weight and tetraphenylphosphonium tetraphenyl borate at a temperature higher than the softening point of the phenol resin. There is described a technique for obtaining an epoxy resin composition which gives a cured product having good storage stability and excellent moisture resistance using the above method. Further, JP-A-6-228280
The publication discloses a non-novolak phenolic resin and tetraphenylphosphonium tetraphenylborate, using a curing agent obtained by heating and mixing at a temperature equal to or higher than the softening point of the non-novolak phenolic resin, to achieve storage stability and fluidity. It is described that an epoxy resin composition having good properties and providing a cured product having excellent curability and moisture resistance is obtained.

However, the techniques described in these publications disclose the use of a phenolic resin as a curing agent for an epoxy resin,
It is clear that the technology has been developed based on the idea that the desired performance is achieved by preliminarily heating and mixing the borate (X) at a temperature higher than the softening point of the phenolic resin and uniformly dispersing the borate. The epoxy resin composition containing a curing agent disclosed in JP-B-56-45491 is capable of increasing the reaction activity of tetraphenylphosphonium tetraphenylborate having good storage stability and moisture resistance to some extent, but has a higher curing property. The curability and preservability were insufficient for use in required applications. Similarly, when the curing agent disclosed in JP-A-6-228280 is used for the resin composition, there is also a problem that the curability and storage stability are insufficient.

On the other hand, the present invention provides a thermal reaction between tetraphenylphosphonium tetraphenylborate (X) and compound (Y) at a predetermined molar ratio,
The phenyl group on the boron side is subjected to a nucleophilic substitution reaction with the phenoxide anion of the compound (Y), and the product is further reacted in a solvent having a boiling point of 60 ° C. or higher, so that boron is formed in the structure of the curing accelerator. Activating the hardening accelerator by releasing from the core is the gist of the technology. Further, in the present invention, in most cases, borate (X)
Is 50 parts by weight based on 100 parts by weight of the compound (Y).
Far more than parts by weight. In this respect, too,
This is different from the technique described in Japanese Patent Publication No. 228280.

[0008]

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.

[0009]

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,
And a compound (C) obtained by reacting the tetraphenylphosphonium tetraphenylborate (X) with the compound (Y) represented by the general formula (1) as an essential component, and the compound (C) is represented by X: After a thermal reaction in a molar ratio of Y of 1: 2 to 4, the reaction is further carried out in a solvent having a boiling point of 60 ° C. or higher, and the boron content in the compound is 0.1%.
It is a thermosetting resin composition characterized by being 6 wt% or less.

[0010]

Embedded image In the formula, the position of the hydroxyl group substituted on the phenyl group is either ortho or para to methylene, and the positions of the two hydroxyl groups may be symmetric or asymmetric.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The compound (A) used in the present invention is not limited as long as it has two or more epoxy groups in one molecule. For example, biphenyl type epoxy resin, novolak type epoxy resin, naphthalene Epoxy resins produced by reacting epichlorohydrin with hydroxyl groups such as phenols such as biphenol, phenolic resins, and naphthols, and olefins such as alicyclic epoxy resins. Epoxy resins that have been oxidized and epoxidized, and those obtained by epoxidizing dihydroxybenzenes such as hydroquinone with epichlorohydrin are also included.

Further, two phenolic hydroxyl groups are contained in one molecule.
The compound (B) having at least one compound acts as a curing agent for the compound (A). 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 in which two or more hydrogen atoms bonded to a sex ring are substituted with a hydroxyl group may be used.

The most important technique in the present invention is to carry out a thermal reaction between tetraphenylphosphonium tetraphenylborate (X) and compound (Y) in a molar ratio of X: Y of 1: 2-4. The product is further reacted in a solvent having a boiling point of 60 ° C. or higher to obtain a boron content of 0.6 wt%.
This is a step of obtaining a compound (C) as described below. In the thermal reaction before this step, the phenyl group, which is the boron-side substituent of borate (X), is deactivated and activated by a kind of nucleophilic substitution reaction of boron with phenolic hydroxyl group. That is, it is a 4-2 functional group reaction of boron having four reaction points and compound (Y) having two reaction points. When the molar ratio of X: Y is 1: 2, theoretically, the boron side Are substituted with the phenoxide anion of the compound (Y), and all the hydroxyl groups of the compound (Y) also react with boron. When the molar ratio of X: Y is 1: 4, all of the substituents on the boron side are substituted with the phenoxide anion of compound (Y), and all of the hydroxyl groups of compound (Y) have reacted uniformly. In this case, one of the two hydroxyl groups of the compound (Y) will be consumed.

When the synthesis reaction is actually carried out, the molar ratio X: Y of the borate (X) to the compound (Y) becomes almost the same as the theory,
An excellent curing accelerator can be obtained when thermally reacted in the range of 1: 2 to 4. When the amount of borate (X) is more than 1: 2, the nucleophilic substitution reaction does not sufficiently occur, and the reaction in the subsequent solvent is also insufficient. If the compound (Y) is in excess of 1: 4, an excess of the compound (Y) will be mixed into the product after the second-stage reaction, and the curing acceleration effect will decrease. As the compound (Y) to be used, a mixture of isomers usually available as an industrial raw material, for example, bisphenol FD manufactured by Honshu Chemical Industry is inexpensive and suitable, but bis (2-hydroxyphenyl) methane and bis (4 -Hydroxyphenyl) methane or the like may have a single structure.

This substitution reaction can be monitored by the amount of distilling benzene during the reaction. It is desirable that the benzene distillation rate, that is, the actual generated weight is 80 wt% or more based on the theoretical generated weight of benzene generated when all the phenyl groups of tetraphenylphosphonium tetraphenylborate are substituted. When the amount is less than 80 wt%, as described in the related art, the phenyl group on the boron side of tetraphenylphosphonium tetraphenyl borate has a small ratio of substitution with phenoxide. is there. The thermal reaction is 15
When the reaction is performed for 1 hour or more in a temperature range of 0 ° C. or more and 230 ° C. or less, the above-described substitution reaction can be sufficiently advanced. If the temperature is lower than 150 ° C., the reaction tends to be slow,
If the temperature exceeds 0 ° C., thermal decomposition of the product may occur.

The solvent used for the reaction in the latter solvent must have a boiling point of 60 ° C. or higher. If the boiling point is lower than 60 ° C., the reaction temperature cannot be increased, and the curing promoting action cannot be sufficiently activated. The type of the solvent is not particularly limited as long as it has a boiling point of 60 ° C. or higher.
Solvents at 0 ° C. or higher are preferred, and particularly commonly used alcohol solvents such as methanol, ethanol, propanol and butanol are preferred.

The reaction time in the solvent is desirably 1 hour or more. However, this reaction does not necessarily have to be a reflux reaction. Need not be.

In the reaction process in the latter solvent, the former reaction product is activated by a substantial change. That is, the boron contained in the structure is released from the molecular structure due to the interaction with the solvent, the boron is lost from the curing accelerator, and the curing promoting property is very activated. The reason that there is a correlation between the boron content and the activity of the curing accelerator is that it is generally considered that trisubstituted borane or the like is similar to the phenomenon that curing inhibition is caused by its Lewis acidity. The degree of progress of the above-mentioned reaction in the solvent and the degree of separation and removal of the released boron component from the curing accelerator determine the boron content contained in the second-stage reaction product (C). When the content is 0.6 wt% or less, an extremely excellent curing promoting effect is exhibited.

In the present invention, the boron content is determined by an oxygen flask combustion method. That is, 10 mg of a sample is burned in a combustion flask made of oxygen in which oxygen has been replaced, and the boron contained in the sample is absorbed in the form of borate ions in an absorbing solution of hydrogen peroxide, which is then subjected to ion exclusion chromatography or the like. And converted to the boron content in the sample.

Using the compound (C) thus synthesized, a compound (A) having two or more epoxy groups in one molecule and a compound (B) having two or more phenolic hydroxyl groups in one molecule And acts as a curing accelerator to promote the reaction of

On the other hand, the thermosetting resin composition of the present invention is also characterized by having a good preservability, but its action mechanism is currently under study. In addition, 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 as needed.

[0022]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the invention thereto.

First, the borate (X) is thermally reacted with the compound (Y), and the product is further reacted in a solvent to synthesize the compound (C). A compound (A) having two or more epoxy groups therein, and 1
In addition to the compound (B) having two or more phenolic hydroxyl groups in the molecule, the mixture is pulverized and mixed, melt-kneaded at 100 ° C. for 5 minutes on a hot plate, and then cooled and pulverized to prepare a sample of the composition. Used for evaluation. Curing torque with a curastometer and differential scanning calorimetry (D
SC). Each measurement method was as follows.

1. Curing Torque (Evaluation of Curability) Using a sample of the resin composition prepared by the method described above, a curast meter (JSR, manufactured by Orientec, Inc.)
(Culastometer PS type), the torque after 175 ° C. and 45 seconds was determined. Torque in a curast meter is a parameter of curability, and a larger value indicates higher curability.

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

Synthesis Example 1 Bisphenol FD (corresponding to compound (Y), manufactured by Honshu Chemical Industry Co., Ltd.) 300.3 g (1.5)
Mol) and 325.6 g of tetraphenylphosphonium tetraphenylborate (X) (0.5 mol, 100 parts by weight of bisphenol FD (Y)) and borate (X) 1
08 parts) in a 3 L separable flask and reacted at 215 ° C. for 4 hours. The amount of benzene distilled in this reaction was 97% by weight of the theoretical amount (that is, the benzene distillation rate was 97%). The resulting product is pulverized,
The mixture was charged in a separable flask, 3 times the amount of the charged weight was added thereto, and the mixture was stirred and reacted at an internal temperature of 82.4 ° C. (boiling point temperature of isopropanol) for 1.5 hours. Thereafter, most of the isopropanol was removed, and low boiling components were further removed under reduced pressure by heating. The product obtained is converted to compound C1
-1. The boron content was determined to be 0.10
wt%.

(Synthesis Example 2) Under the same conditions as in Synthesis Example 1, bisphenol FD (Y) and tetraphenylphosphonium tetraphenylborate (X) were thermally reacted.
The obtained product was pulverized, charged into a separable flask, and toluene was added in an amount 3 times the charged weight, and the internal temperature was adjusted to 11.
The mixture was stirred and reacted at 0.6 ° C. (boiling point temperature of toluene) for 4 hours. Thereafter, most of the toluene was removed, and low boiling components were further removed under reduced pressure by heating. The obtained product is compound C
1-2, and the boron content was measured to be 0.3 wt.
%Met.

(Synthesis Examples 3 to 7) Type of compound (Y), X
All the basic operations were performed in the same manner as in Synthesis Example 1 except that the molar ratio of / Y and other reaction conditions were as shown in Table 1, and compounds C2, C3, C4, C5,
C6 was prepared. The boron content of these compounds was measured, and the results are shown in Table 1.

[0029]

[Table 1]

(Comparative Synthesis Example 1) JP-B-56-45491
In accordance with the description in JP-A No. 10-110, 100 parts of a phenol novolak resin having an average molecular weight of about 800 and a softening point of 80 to 90 ° C., and 10 parts of tetraphenylphosphonium tetraphenylborate are pulverized and mixed by a mixer, and mixed into a 500 ml four-necked round. The mixture was placed in a bottom flask, heated to 140 ° C. in an oil bath, and heated and mixed with a stirring motor for 15 minutes to obtain a curing agent 1.

(Comparative Synthesis Example 2) JP-A-6-228280
No. 1,100,1,3-triphenolpropane having a softening point of 110 ° C. and 10 parts of tetraphenylphosphonium tetraphenylborate are placed in a 1-liter four-necked flask and placed at 150 ° C. for 1 hour. After standing, the mixture was mixed at 200 ° C. for 1 hour to obtain a curing agent 2.

(Comparative Synthesis Example 3) Bisphenol FD
(Y, manufactured by Honshu Chemical Industry) 300.3 g (1.5 mol), 32.6 g of tetraphenylphosphonium tetraphenylborate (X) (0.05 mol, molar ratio X: Y = 1:
30, a ratio of 10.9 parts of borate (X) to 100 parts by weight of bisphenol FD (Y)) was charged into a 3 L separable flask and reacted at 150 ° C. for 6 hours. The amount of benzene distilled was 93 wt% of the theoretical amount (that is, the benzene distillation rate was 93%). The obtained product was pulverized, charged in a separable flask, added with diethyl ether three times the charged weight, and stirred and reacted at an internal temperature of 34.6 ° C. (the boiling point of diethyl ether) for 6 hours. Thereafter, most of the diethyl ether was removed, and the components having a low boiling point were further removed under reduced pressure by heating. The resulting product was converted to compound C7
The boron content was measured and found to be 0.17 wt%.

However, this is because the molar ratio X: Y of borate (X) to bisphenol FD (Y) is 1:30, and there is an excess of Y, so that the boron content already exists at the time of the first-stage reaction product. 0.6 wt% or less, which is outside the scope of the present invention.

(Comparative Synthesis Example 4) Bisphenol FD
(Y) 100.1 g (0.5 mol) and tetraphenylphosphonium tetraphenylborate (X) 325.6 g
(0.5 mol) was charged into a 3 L separable flask and reacted at 230 ° C. for 8 hours. The amount of benzene distilled in this reaction was 31 wt% of the theoretical amount (that is, the benzene distillation rate was 31%). The obtained product was pulverized, charged into a separable flask, added with diethyl ether three times the charged weight, and stirred and reacted at 34.6 ° C. for 6 hours. Thereafter, most of the solvent was removed, and low boiling components were further removed under reduced pressure by heating. The obtained product was used as compound C8, and the boron content was determined to be 1.3 wt%.

(Comparative Synthesis Example 5) A compound obtained by thermally reacting bisphenol FD (Y) with tetraphenylphosphonium tetraphenylborate (X) under the same conditions as in Synthesis Example 1 was used as Compound D And (D is not subjected to a reaction treatment in a solvent.)

(Examples 1 to 7 and Comparative Examples 1 to 6) Samples of the resin composition were prepared by the above-described method according to the formulations shown in Table 2 and evaluated. In Comparative Examples 1 and 2, curing agents 1 and 2 were used instead of the compounds (B) and (C) in Examples.
2, and in Comparative Examples 3 and 6, triphenylphosphine and compound D were used instead of compound (C). The evaluation results of each resin composition are collectively 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, while Comparative Examples 1 to 3 In the case of the method according to the prior art, the curability is clearly poor and the storage stability is also poor. Further, Comparative Examples 4 and 5 have good preservability but not good curability. Compound C7 used in Comparative Example 4 was subjected to a thermal reaction between tetraphenylphosphonium tetraphenylborate (X) and compound (Y) at a molar ratio of 1/30 (used in excess of compound (Y)), and the boiling point was This is an example in which the reaction treatment was carried out in a solvent lower than 60 ° C., and the compound C8 used in Comparative Example 5 had a molar ratio of 1/1 (excess use of borate (X)).
This is an example in which a thermal reaction is performed in a solvent having a boiling point lower than 60 ° C. Compound D used in Comparative Example 6 did not react in a solvent and had a boron content of 1.16.
wt% and higher than 0.6 wt%, the preservability is good,
Curability has not reached the level of Examples 1-7.

[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.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Nagata 2-5-8 Higashishinagawa, Shinagawa-ku, Tokyo Sumitomo Bakelite Co., Ltd. (72) Inventor Hitto Akiyama 2-5-2 Higashishinagawa, Shinagawa-ku, Tokyo No. Sumitomo Bakelite Co., Ltd. F-term (reference) 4J036 AC01 AC05 AD07 AF05 AF06 AJ14 AK01 FA09 FA10 FA14 FB06 FB07 FB08 GA29 JA07

Claims (5)

[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 tetraphenylphosphonium tetraphenylborate (X). A compound (C) obtained by reacting the compound (Y) represented by the general formula (1) is an essential component, and the compound (C) has a molar ratio of X: Y in the range of 1: 2 to 4. A thermosetting resin composition obtained by further proceeding the reaction in a solvent having a boiling point of 60 ° C. or more, and having a boron content of 0.6 wt% or less in the compound. . Embedded image In the formula, the position of the hydroxyl group substituted on the phenyl group is either ortho or para to methylene, and the positions of the two hydroxyl groups may be symmetric or asymmetric. 2. The thermal reaction between tetraphenylphosphonium tetraphenylborate (X) and compound (Y) is as follows.
The thermosetting resin composition according to claim 1, wherein the heat treatment is performed for 1 hour or more in a temperature range of 0 ° C or more and 230 ° C or less. 3. The method according to claim 1, wherein the amount of benzene generated during the thermal reaction between the tetraphenylphosphonium tetraphenylborate (X) and the compound (Y) is 80% by weight or more of the theoretical amount. The thermosetting resin composition according to claim 1 or 2. 4. The solvent according to claim 1, wherein the solvent having a boiling point of 60 ° C. or more has at least one hydroxyl group in one molecule, and the reaction in the solvent is carried out for 1 hour or more. Thermosetting resin composition. 5. The solvent according to claim 1, wherein the solvent having a boiling point of 60 ° C. or higher is an alcohol solvent.
The thermosetting resin composition according to the above.