JPH05105801A - Production of phenolic resin molding material - Google Patents

Abstract

PURPOSE:To improve the storage stability of a resol resin as the material of a phenolic resin molding material, to improve the storage stability of a molding material containing the resol resin, and to shorten the time necessary to mold the molding material. CONSTITUTION:A tert. amine [e.g. (C2H5)3N] having a small reaction accelerating effect is used as a catalyst for the synthesis of a resol resin. When a molding material is produced by adding a filler to the resol resin and kneading the resulting mixture under agitation, an alkaline earth metal hydroxide [e.g. Ca(OH)2] having a large reaction accelerating effect is used as a cure accelerator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a phenol resin molding material suitable for molding automobile engine parts such as insulators and plates.

[0002]

2. Description of the Related Art A resole resin, which is a raw material for a phenol resin molding material, is conventionally synthesized by reacting phenols and formaldehyde under a Ca (OH) ₂ catalyst. Then, a filler, an additive, and a curing accelerator Ca (OH) ₂ are mixed with the resole resin, mixed and kneaded, and then pulverized to obtain a molding material.

[0003]

However, in the above-mentioned conventional techniques, Ca (OH) ₂ having a large curing accelerating property is used as a catalyst and a curing accelerating agent both at the time of synthesizing a resole resin and at the time of forming a molding material. Therefore, there is a problem that the reaction is sensitive to temperature and the reaction is likely to proceed, and the storage stability of the resol resin and the storage stability after forming the molding material are poor. The problem to be solved by the present invention is to improve the storage stability of a resole resin, which is a raw material of a phenol resin molding material, as well as the storage stability of a molding material using the same, and to shorten the time required for molding.

[0004]

In order to solve the above problems, the production method according to the present invention uses a tertiary amine catalyst in the step of synthesizing a resole resin. Further, it is characterized in that a hydroxide of an alkaline earth metal is used as a hardening accelerator when forming a molding material.

[0005]

In the production method according to the present invention, since the tertiary amine catalyst having a small reaction progress is used during the synthesis of the resole resin, the synthesized resole resin has excellent storage stability. Since the curability at the time of molding is poor as it is, the curing at the time of molding becomes faster by adding a hydroxide of an alkaline earth metal, which has a large curing accelerating property, when forming a molding material. Although the curing at the time of molding is fast, the storage stability of the molding material is excellent in such a combination of the tertiary amine and the alkaline earth metal hydroxide.

[0006]

EXAMPLES Phenols used in the reaction in the production method according to the present invention are monovalent phenols such as phenol, cresol and xylenol, and polyhydric phenols such as catechol and resorcin. Formaldehyde is paraformaldehyde and formalin. The tertiary amine used for synthesizing the resole resin is triethylamine, trimethylamine, or the like. The alkaline earth metal hydroxide used as the curing accelerator is calcium hydroxide, barium hydroxide, potassium hydroxide or the like. In addition to glass fibers, inorganic fillers such as silica, glass powder, talc, kaolin clay, and silica-alumina are suitable as the filler to be added when forming the molding material. Coloring agents such as carbon black and release agents such as zinc stearate and stearic acid are appropriately added as additives. Hereinafter, examples according to the present invention will be described in detail.

Example In the formulation shown in Table 1, phenol and paraformaldehyde were heated and reacted at 60 to 100 ° C. for 4 to 5 hours in the presence of a (C ₂ H ₅ ) ₃ N catalyst, and then ammonia was added to the mixture for 90 to 90 minutes.
A resol resin was synthesized by reacting at 95 ° C for 2 to 3 hours.
A glass fiber, a glass powder, an additive, and a curing accelerator Ca (OH) ₂ were blended with this resole resin, mixed and kneaded with a Henschel mixer, and ground to obtain a phenol resin molding material.

Conventional Example With the formulation shown in Table 1, phenol and paraformaldehyde were heated and reacted at 60 to 80 ° C. for 1 to 3 hours in the presence of a Ca (OH) ₂ catalyst, and then ammonia was added to the mixture to further add 80 to 1
Resole resin was synthesized by reacting at 00 ° C. for 3 to 7 hours.
Hereinafter, a phenol resin molding material was obtained in the same manner as in the examples.

[0009]

[Table 1]

The resole resins in the above-mentioned examples and conventional examples were allowed to stand in a thermostatic chamber at 40 ° C., and GT (gelling time) was taken every day.
Was measured. Further, the phenol resin molding material was left in a thermostatic chamber at 30 ° C., and SF (spiral flow) was measured every two days. These are for evaluating the storage stability of the resole resin and the phenol resin molding material. The evaluation results are shown in FIGS. 1 and 2. In addition, an actual molded product (insulator) is molded with a 100-ton injection molding machine by using the phenol resin molding materials in the above-mentioned examples and conventional examples, and the molding cycle time (that is, curability) is determined from the holding pressure at the time of molding. evaluated. The results of evaluation are shown in Table 2.

[0011]

[Table 2]

[0012]

As is apparent from FIG. 1, the storage stability of the resole resin is good in the method according to the present invention. Further, as is clear from FIG. 2, in the method according to the present invention,
The number of days after the phenol resin molding material can be molded is long, and the storage stability is good. Further, it can be seen from Table 2 that the phenol resin molding material produced by the method according to the present invention has a short molding cycle, that is, good curability.

[Brief description of drawings]

FIG. 1 is a diagram showing the relationship between the storage time of a resole resin and GT (gel time).

FIG. 2 is a diagram showing a relationship between a storage time of a phenol resin molding material and SF (spiral flow).

Claims (1)

[Claims] 1. A step of reacting phenols and formaldehyde in the presence of a tertiary amine catalyst to synthesize a resole resin, and adding a hydroxide of an alkaline earth metal as a curing accelerator to the resole resin together with a filler. A method for producing a phenol resin molding material, which comprises a step of mixing and kneading.