JP3126686B2 - Method for producing phenol aralkyl resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a phenol aralkyl resin which is inexpensive and has excellent storage stability. More specifically, the present invention relates to a method for producing a high-purity phenol aralkyl resin that hardly deteriorates with time when used as an epoxy resin curing agent for semiconductor encapsulants.

[0002]

2. Description of the Related Art Phenol aralkyl resins are useful compounds as curing agents, adhesives and molding materials for epoxy resins for semiconductor encapsulants. Their production method is to use aromatic compounds such as dichloro-p-xylene as raw material compounds. Generally, an aromatic bisalkoxymethyl compound such as an aromatic bishalogenomethyl compound or dimethoxy-p-xylene is used, and a compound is produced from these and a phenol by a condensation reaction.

An important use of a phenol aralkyl resin is as a curing agent for an epoxy resin for a semiconductor encapsulant, but when used for this purpose, it is necessary to minimize the incorporation of ionic impurities such as polymerized metal components and acidic substances. As a method for producing such a high-purity phenol aralkyl resin, for example, a method of reacting the above aromatic bishalogenomethyl compound with a phenol compound without a catalyst has been proposed (Japanese Patent Application Laid-Open No. 6-10667).

[0004] However, although the phenol aralkyl resin obtained by the reaction without a catalyst is a high-purity product, it has a problem that it is oxidized during storage and its curability decreases with time when used as an epoxy resin curing agent. is there. In particular, this deterioration with time is likely to occur when triphenylphosphine (TPP), which is the most common curing accelerator for semiconductor encapsulant applications, is used.

[0005] On the other hand, if the above-mentioned aromatic bisalkoxymethyl compound containing no halogen is used as a xylylene compound and synthesized using an acidic compound as a catalyst, such a problem of a change with time does not occur. In this method, as a catalyst, sulfuric acid, diethyl sulfate, p-toluenesulfonic acid, and a Friedel-Crafts type catalyst such as stannic chloride, zinc chloride, and ferric chloride are used. However, this method is disadvantageous in cost because an expensive xylylene compound is used as a raw material. In addition, there is also a possibility that a large amount of ionic impurities derived from the acid catalyst may be problematic.

[0006]

SUMMARY OF THE INVENTION The present inventors have conducted intensive studies to solve this problem. As a result, it has been found that the curability over time when a TPP curing accelerator is used is partially reduced during storage. Was found to be oxidized to form a peroxide, which caused the TPP as a curing accelerator to be oxidized and deactivated.
The inventors have found that deactivation by oxidation of P can be prevented by the presence of a trace amount of an acid, a salt comprising an acid and an organic base, or an organic base in the resin, and have completed the present invention.

Accordingly, an object of the present invention is to solve the above problems and provide a method for producing a high-purity phenol aralkyl resin which is inexpensive and has excellent storage stability by using an inexpensive aromatic bishalogenomethyl compound as a raw material. Is to do.

[0008]

The present invention provides a compound represented by the following general formula (1): R- (CH ₂ X) ₂ (1) wherein R is a phenyl group, an alkyl-substituted phenyl group,
X represents a biphenyl group, a divalent diphenyl ether residue, or a naphthyl group, and X represents a halogen atom), and a phenol compound is reacted with a phenol compound without adding a catalyst substance. And a salt comprising an acid and an organic base or an organic base in an amount of from 20 to 200 ppm.

[0009]

Hereinafter, the present invention will be described in detail. The phenol aralkyl resin of the present invention is obtained by reacting an aromatic bishalogenomethyl compound represented by the above general formula (1) with a phenol compound without adding a catalyst substance, and then reacting with an acid, an organic base, or both. Can be produced by adding the following salt.

The aromatic bishalogenomethyl compound which is a raw material of the method of the present invention is represented by the following general formula (1). R- (CH ₂ X) ₂ (1) where R is the same aromatic hydrocarbon group as described above,
Is a halogen atom such as chlorine, bromine or fluorine, and chlorine is particularly preferable.

Examples of such a raw material compound are those in which R is a phenyl group, such as 1,2-di (chloromethyl) benzene, 1,2-di (bromomethyl) benzene,
Di (chloromethyl) benzene, 1,3-di (fluoromethyl) benzene, 1,4-di (chloromethyl) benzene, 1,4-di (bromomethyl) benzene, 1,4-di (fluoromethyl) benzene, etc. , R is an alkyl-substituted phenyl group, for example, 1,4-di (chloromethyl) 2,5-dimethylbenzene, 1,3-di (chloromethyl) -4,6-dimethylbenzene, 1,3 -Di (chloromethyl) -2,4-dimethylbenzene, examples of the case where R is a biphenyl group include 4,4'-bis (chloromethyl) biphenyl, 4,4'-bis (bromomethyl) biphenyl, and R is 4,4'-bis (chloromethyl) diphenyl ether as an example when it is a biphenyl ether residue, and 2,7-di (chloromethyl) na as an example when R is a naphthyl group And the like can be given the array type.

Of these aromatic bishalogenomethyl compounds, 1,4-di (chloromethyl) benzene is the most readily available and common raw material.

The phenol compound used as the other raw material in the production method of the present invention includes phenol,
(O-, m-, p-) cresol, xylenol, (o
-, P-) Monocyclic phenol compounds such as ethylphenol, butylphenol, halogenated phenol, catechol, resorcin, or biphenol, bisphenol A, bisphenol S, bisphenol F, α-
Examples thereof include polycyclic phenol compounds such as naphthol and β-naphthol. One or more of these can be used, but phenol is particularly preferred.

In the present invention, the production of the phenol aralkyl resin is carried out without adding a catalytic substance, and the reaction product obtained by the condensation reaction is obtained by removing the unreacted monomer from the reaction product. Or an organic base is added later.

In the present invention, no catalyst substance such as an acid catalyst is added in the condensation reaction. This is because the water contained in the raw material hydrolyzes with the aromatic bishalogenomethyl compound to generate hydrogen halide, and a part of the hydrogen halide acts as an acid catalyst to cause a reaction. . Therefore, water may be added from outside to promote the reaction. When water is added, it may be added in an amount of 0.005 to 1, preferably 0.005 to 0.5% by weight based on the total amount of the raw materials.
Even if the added amount of water is further increased, no improvement in the added effect is observed.

Acids added after removing unreacted monomers from the condensation reaction product include organic acids such as oxalic acid, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, and diethylsulfuric acid, sulfuric acid, phosphorus acid, and the like. And inorganic acids such as acid and nitric acid.

Examples of the organic base include 2-methylimidazole, 2,4-dimethylimidazole, and 2-ethyl-imidazole.
Imidazole compounds such as 4-methylimidazole, tertiary amines such as triethylamine, triethylenediamine, 1,8-diazabicyclo (5,4,0) undecene-7, and organic phosphine compounds such as triphenylphosphine, trimethylphosphine and triethylphosphine. Is mentioned.

Further, a salt comprising an acid and an organic base can be added. Acids and organic bases to form salts are
The above-mentioned acids and organic bases mentioned as additives can be used. In the present invention, it is particularly preferable to add a salt composed of trifluoromethanesulfonic acid and 1,8-diazabicyclo (5,4,0) undecene-7.

An acid to be added later, a salt comprising an acid and an organic base,
Alternatively, the added amount of the organic base is 20 to 200 ppm, more preferably 30 to 150 ppm. 20p added
pm or less, the storage stability is inferior, and when it is 200 ppm or more, ionic impurities become too large, the electric conductivity of the extraction water becomes high, and the high purity point characteristic of the phenol aralkyl resin of the present invention is lost. Would.

The additives after the reaction in the present invention include:
An acid, an organic base or a salt composed of both can provide an effect of improving storage stability.However, from the viewpoint of suppressing an increase in electric conductivity of resin extraction water, a salt composed of an acid and an organic base is present. Is most preferred.

The reaction between the aromatic bishalogenomethyl compound and the phenol compound in the present invention can be carried out by a known method. The reaction ratio of the raw material is such that the bishalogenomethyl compound is added to the phenol compound in an amount of 1 mole per mole.
It is preferably in the range of 1 to 0.8 mol, particularly 0.2 to 0.6 mol. If the amount of the bishalogenomethyl compound is less than 0.1 mol, unreacted phenol increases and the yield decreases, which is not preferable. Further, the molecular weight is reduced, the softening point is lowered, and cold flow is easily caused. On the other hand, when the amount of the bishalogenomethyl compound exceeds 0.8 mol, the molecular weight increases and the melt viscosity increases, so that the fluidity at the time of molding tends to decrease.

The reaction is usually carried out at 80 to 180 ° C. for 1 hour.
This is performed for about 10 hours. The reaction may be performed while all the raw materials are charged at once and the temperature is raised, or may be performed by sequentially adding an aromatic bishalogenomethyl compound while keeping the phenol compound at a constant temperature in advance. The reaction can be carried out without a solvent, but an organic compound that does not directly participate in the reaction (eg, toluene, xylene, monochlorobenzene, dichlorobenzene, etc.) may coexist as a solvent. By the coexistence of the solvent, the raw material components can be dissolved and homogenized, and the separation and recovery of the reaction product become easy.

In the reaction of the present invention, hydrogen halide gas is generated as the reaction proceeds, and a part thereof acts as an acid catalyst for the reaction. This hydrogen halide gas is an inert gas such as nitrogen gas. May be removed from the system by aeration, or may be removed under reduced pressure. After the reaction, the unreacted phenol compound and the solvent are removed by a method such as distillation under reduced pressure, and the acid, a salt composed of an acid and an organic base, or an organic base is added, whereby the phenol aralkyl resin of the present invention is added. Get.

Most of the hydrogen halide by-produced in the reaction can be removed by blowing an inert gas during the reaction, and furthermore, if the unreacted phenol compound is distilled off under reduced pressure, there is a practical problem. It can be removed to an unacceptable level.

[0025]

The present invention will be described below in detail with reference to examples. In the examples, parts and% are parts by weight and% by weight unless otherwise specified. The methods for evaluating the physical properties of the phenol aralkyl resins obtained in Examples and Comparative Examples are as follows.

(1) Measurement of Gel Time The resin immediately after production in Examples and Comparative Examples was pulverized using a coffee mill, and about 10 g of the resin was sealed in an aluminum pack and placed in a thermostat at 25 ° C. After leaving for 14 days, each resin was mixed with a biphenyl-type epoxy resin at an equivalent ratio of 1: 1 and triphenylphosphine as a curing accelerator was further mixed with 1 phr, and the gel time was initially and after standing at 25 ° C. for 14 days. Was measured. The gel time was measured by a stroke cure method on a hot plate at 160 ° C.

(2) Measurement of Electric Conductivity 8 g of the resin was extracted with 80 g of pure water at 95 ° C. for 20 hours, and the extracted water was used with an electric conductivity meter “DS-12” manufactured by HORIBA. I went.

Example 1 A four-necked flask equipped with a stirrer, a thermometer, a condenser, and a nitrogen gas inlet tube was prepared as follows:
1,4-di (chloromethyl) benzene 175 as raw material
Parts (1 mol) and 188 parts (2 mol) of phenol containing 0.02% by weight of water were charged, and the temperature was increased while stirring under a nitrogen stream to raise the internal temperature to 120 ° C. and maintained for 2 hours. Thereafter, the temperature was raised to 150 ° C. and maintained for another 2 hours. The hydrogen chloride generated at this time was removed by trapping with an aqueous sodium hydroxide solution.

Next, unreacted phenol in the system was distilled off under reduced pressure to obtain a condensation reaction product. Next, trifluoromethanesulfonic acid (TFMS) and 1,8-diazabicyclo (5,4,0) undecene-7 were added to the condensation reaction product.
(DBU) was prepared to have a molar ratio of 1/1.
% Mixed aqueous solution was added so as to be 900 ppm with respect to the condensation reaction product (TFMS / DBU added amount 90 ppm)
Then, the mixture was stirred at 150 ° C. for 30 minutes and uniformly mixed.

The phenol aralkyl resin, which is a condensation reaction product, has a softening point of 82 ° C. and a melt viscosity at 150 ° C. of 310.
The cps and the hydroxyl equivalent were 170 g / eq. Gel time and electric conductivity of the obtained resin were measured.
Table 1 shows the results.

Example 2 A condensation reaction and unreacted phenol were distilled off in the same manner as in Example 1 to obtain a condensation reaction product. To this condensation reaction product, a 10% methanol solution of diethyl sulfate was added so as to be 500 ppm with respect to the condensation reaction product (the addition amount of diethyl sulfate was 50 ppm), and the mixture was stirred at 150 ° C. for 30 minutes and uniformly mixed.

The phenol aralkyl resin of the condensation reaction product has a softening point of 83 ° C. and a melt viscosity at 150 ° C. of 320 c.
ps and the hydroxyl equivalent were 172 g / eq. Gel time and electric conductivity of the obtained resin were measured. Table 1 shows the results.

Example 3 The condensation reaction and unreacted phenol were distilled off in the same manner as in Example 1 to obtain a condensation reaction product. 1,8-diazabicyclo (5,5
(4,0) 10% aqueous solution of undecene-7 (DBU)
Add to 900 ppm based on the condensation reaction product (D
The amount of BU added was 90 ppm), and the mixture was stirred at 150 ° C. for 30 minutes and uniformly mixed.

The condensation reaction product phenol aralkyl resin has a softening point of 80 ° C. and a melt viscosity at 150 ° C. of 300 c.
ps and hydroxyl equivalent were 175 g / eq. Gel time and electric conductivity of the obtained resin were measured. Table 1 shows the results.

Example 4 The condensation reaction and unreacted phenol were distilled off in the same manner as in Example 1 except that 0.1 part of water was added to the raw materials to obtain a condensation reaction product. Then, TFM was added to the condensation reaction product in the same manner as in Example 1.
S / DBU mixed aqueous solution is 900p
pm and uniformly mixed.

The phenol aralkyl resin which is a condensation reaction product has a softening point of 80 ° C. and a melt viscosity at 150 ° C. of 290.
The cps and the hydroxyl equivalent were 170 g / eq. Gel time and electric conductivity of the obtained resin were measured.
Table 1 shows the results.

[Comparative Example 1] The condensation reaction and unreacted phenol were distilled off in the same manner as in Example 1. After the phenol was distilled off, a condensation reaction product was obtained without adding an acid, an organic base or a salt thereof. Was.

The phenol aralkyl resin of the condensation reaction product has a softening point of 83 ° C. and a melt viscosity at 150 ° C. of 320.
The cps and hydroxyl equivalent were 173 g / eq. Gel time and electric conductivity of the obtained resin were measured.
Table 1 shows the results.

Comparative Example 2 Using the same apparatus as in Example 1, 1,4-di (chloromethyl) benzene 17 was used as a raw material.
5 parts (1 mol) and 188 parts (2 mol) of phenol were added, and 0.13 part by weight of diethyl sulfate was further added as a catalyst.
C. and kept for 2 hours. Thereafter, the temperature was raised to 150 ° C. and maintained for another 2 hours. The hydrogen chloride generated at this time was removed by trapping with an aqueous sodium hydroxide solution. Next, unreacted phenol in the system was distilled off by distillation under reduced pressure to obtain a condensation reaction product.

The phenol aralkyl resin of this condensation reaction product has a softening point of 80 ° C. and a melt viscosity at 150 ° C. of 30.
0 cps and the hydroxyl equivalent was 172 g / eq. Gel time and electric conductivity of the obtained resin were measured. Table 1 shows the results.

[0041]

[Table 1]

As is clear from the results shown in Table 1, according to the method of the present invention (Examples 1 to 4) in which an organic acid, an organic base or a salt thereof was added after the reaction without adding a catalytic substance,
A phenol aralkyl resin having good storage stability and relatively high purity can be obtained. On the other hand, in the conventional method of Comparative Example 1, although a high-purity phenol aralkyl resin was obtained by reacting without adding a catalytic substance, the storage stability was poor. The resin obtained by the conventional method of Comparative Example 2 had good storage stability but high electrical conductivity.

[0043]

According to the method of the present invention, the curability hardly deteriorates with time, the storage stability is excellent, and the electric conductivity is low.
A relatively high purity phenol aralkyl resin can be produced. Such a resin can be widely used in the field of electronic materials and adhesives, including semiconductor sealing materials.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08G 61/00-61/12

Claims (3)

(57) [Claims] (1) R- (CH ₂ X) ₂ (1) wherein R is a phenyl group, an alkyl-substituted phenyl group,
X represents a biphenyl group, a divalent diphenyl ether residue, or a naphthyl group, and X represents a halogen atom), and a phenol compound is reacted with a phenol compound without adding a catalyst substance. And a salt comprising an acid and an organic base or an organic base in an amount of from 20 to 200 ppm. 2. Water is added in an amount of 0.005 to the total amount of the reaction raw materials.
The method for producing a phenol aralkyl resin according to claim 1, wherein the reaction is carried out by adding 1 to 1% by weight. 3. A salt comprising an acid and an organic base, wherein trifluoromethanesulfonic acid and 1,8-diazabicyclo (5,
The method for producing a phenol aralkyl resin according to claim 1, which is a salt comprising (4, 0) undecene-7.