JPH072830B2 - Method for producing phenolic resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention has the general formula [I] (Wherein R represents a methyl group or a hydrogen atom and n represents an integer of 0 to 15).

[Problems to be Solved by Prior Art and Invention]

Among phenolic resins, phenol novolac resins have recently been used in large amounts as curing agents for epoxy resins for electrical and electronic materials. In particular, high-purity phenol novolac has been used as a curing agent for ortho-cresol novolac epoxy resin used for electronic materials. However, with the high integration and size of integrated circuits, internal stress and hygroscopicity generated during curing have become problems.

On the other hand, the inventors of the present invention disclosed in Japanese Patent Application Laid-Open No. 61-123618 (Japanese Patent Application No.
9-245795), as seen in JP-A-60-244769,
We have examined the use of epoxidized polymers of dicyclopentadiene and phenols and their use as epoxy resin curing agents.

However, in the conventional method for preparing a polymer found in JP-A No. 61-123618, unreacted monomer and Lewis acid remain in the resin, so the polymer may be used as a curing agent for an epoxy resin, or a polymer may be further added. When epoxidized into an epoxy resin, there is a drawback that residual ionic impurities and monomers have a bad influence on electrical characteristics and hygroscopicity.

[Means for solving problems]

Therefore, as a result of intensive studies, the present inventors have obtained a high-purity polymer having less residual monomer and residual catalyst by dissolving the polymer in an organic solvent after completion of the polymerization reaction and adding a washing step with an aqueous alkali hydroxide solution. I found a thing.

〔The invention's effect〕

The high-purity polymer obtained by the method of the present invention can be used as a curing agent for an epoxy resin and also as a raw material for an epoxy resin.

[Work]

 The present invention will be described in detail below.

Implementation of the manufacturing method of the present invention involves three steps. First
The step is a step of polymerizing phenols and dicyclopentadiene using a catalyst, and the second step is to dissolve the polymer as it is in an organic solvent, extract the residual monomer and the residual catalyst from the organic layer with an aqueous alkali hydroxide solution, and wash with water. The step and the third step are steps of heating the organic solvent from the organic layer, distilling it off under reduced pressure, and concentrating.

Examples of the phenols used in the first step include phenol, orthocresol, metacresol, isopropylphenol, nonylphenol and the like.

Any Lewis acid can be used as the catalyst used in the first step. As the Lewis acid, AlCl
₃ , BF ₃ , ZnCl ₂ , H ₂ SO ₄ , TiCl ₄ , H ₃ PO _{4 and the} like can be mentioned. It is also possible to use one kind or a mixture of two or more kinds.

The phenols are heated and melted, a catalyst is added thereto and uniformly dissolved, and then dicyclopentadiene is added dropwise at 50 to 180 ° C, preferably 80 to 150 ° C. The amount of each catalyst added is 0.001 to 0.10 per mol of dicyclopentadiene.
Mol, preferably 0.005-0.08 mol and phenols 0.1-
It is 10.00 mol, preferably 0.3 to 4 mol. In this step, dicyclopentadiene and phenols may be added. Further, the catalyst may be gradually added to the mixture of dicyclopentadiene and phenols. Depending on the raw material composition, the addition time is 1 to 10 hours, and then the reaction is performed for several hours.

In the second step, the polymer obtained in the first step is dissolved in an organic solvent.

Organic solvents used here include halogenated hydrocarbons such as chloroform, methylene chloride, carbon tetrachloride, ketones such as methyl isobutyl ketone and methyl ethyl ketone, nitrobenzene, benzene, carbon disulfide, etc. Any organic solvent that is stable to the alkaline aqueous solution and has low compatibility with water may be used.

An aqueous solution of alkali hydroxide is added to the polymer solution to extract the monomer and the residual catalyst. The concentration of the aqueous solution of alkali hydroxide is 30% to 0.001%, and it is preferably 5% to 0.01% although it varies depending on the amount of the polymer, the concentration of the organic layer, and the type and amount of the residual monomer. The extracted organic layer is washed repeatedly with water to remove neutral and ionic impurities. At that time, hydrochloric acid, sulfuric acid, phosphoric acid or the like may be used for neutralizing the organic layer.

In the third step, the washed polymer solution is heated with an organic solvent,
Evaporate under reduced pressure to obtain a high-purity dicyclopentadiene phenol aggregate.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. All parts below indicate parts by weight.

Example 1 1000 parts of para-cresol was charged into a reactor equipped with a thermometer, a cooler, and a stirrer dropping tube, and maintained at 100 ± 5 ° C.
After adding 15 parts of 7% BF ₃ ether complex, 4169 parts of dicyclopentadiene was added dropwise over 4 hours. After dropping
After maintaining at 100 ± 5 ° C. for 2 hours, the mixture was allowed to cool and the polymer was dissolved in 3920 parts of methyl isobutyl ketone. 2350 parts of a 2% aqueous sodium hydroxide solution was added to the polymer solution, and the mixture was shake-extracted twice. After that, the organic layer was repeatedly washed with water, and methyl isobutyl ketone was distilled off from the polymer solution by heating.

The solvent distillation conditions were finally 3.0 mmHg and 160 ° C. After distilling off the solvent, 1274 parts of a high-purity dicyclopentadiene phenol polymer was obtained.

The IR and GPC charts and analytical values of the obtained polymer are shown in FIGS. 1 and 2 and Table 1, respectively.

Comparative Example 1 After the polymerization reaction in Example 1, the unreacted monomer and the catalyst were removed only by heating, depressurizing and distilling without performing the extraction operation. The polymerization reaction conditions and the like were the same as in Example 1.

The GPC chart of the obtained polymer is shown in FIG. 3, and the analytical values are shown in Table 1.

Example 2 1000 parts of para-cresol and 315 parts of dicyclopentadiene were used, and 3500 parts of chloroform was used as an organic solvent. Thereafter, the same operation as in Example 1 was carried out to obtain 717 parts of a polymer. Fig. 4 shows the GPC chart of the polymer and Fig. 5 shows the IR chart.
The figures and analysis values are shown in Table 1, respectively.

Example 3 1000 parts of orthocresol and 315 parts of dicyclopentadiene were used, and 3500 parts of chloroform was used as an organic solvent.
Thereafter, the same operation as in Example 1 was carried out to obtain 729 parts of a polymer. Figure 6 shows the GPC chart of polymer and IR chart shows 7
The figures and analysis values are shown in Table 1, respectively.

Example 4 1000 parts of phenol and 366 parts of dicyclopentadiene were used, and 3500 parts of chloroform was used as an organic solvent. Thereafter, the same operation as in Example 1 was carried out to obtain 582 parts of a polymer.

The GPC chart of the polymer is shown in FIG. 8, the IR chart is shown in FIG. 9, and the analytical values are shown in Table 1.

[Brief description of drawings]

1 and 2 are charts showing IR and GPC of the polymer obtained in Example 1 of the present invention, and FIG. 3 is Comparative Example 1
FIG. 4 is a chart showing GPC of the polymer obtained in Example 1, FIGS. 4 and 5 are charts showing GPC and IR of the polymer obtained in Example 2, and FIGS. 9 is a table showing GPC and IR of the polymer obtained in Example 3, and FIGS. 8 and 9 are GPC and IR of the polymer obtained in Example 4.
FIG.

Claims (3)

[Claims] 1. The following three steps, (1) a step of polymerizing phenols and dicyclopentadiene using a catalyst, (2) a polymer is dissolved in an organic solvent, and an alkali hydroxide aqueous solution is prepared from the organic solution. Represented by the following general formula [I], which comprises a step of extracting and removing unreacted monomers and a catalyst by means of, followed by washing the organic layer after extraction with water, and (3) a step of heating the organic solvent from the organic layer and distilling it off under reduced pressure. Method for producing high-purity phenolic resin. (In the formula, R represents a methyl group or a hydrogen atom, and n represents an integer of 0 to 15.) 2. The method for producing a high-purity phenol resin according to claim 1, wherein the organic solvent is a halogenated hydrocarbon. 3. The method for producing a high-purity phenol resin according to claim 1, wherein the organic solvent is a ketone.