JPH08325434A - Production of resol resin molding material and of molded article - Google Patents

Abstract

PURPOSE: To obtain a process for producing a resol resin molding material excellent in mold filling property and a process in which excellent mold filling property is attained in producing a molded article. CONSTITUTION: A resol resin obtained by condensing a phenol with formaldehyde in the presence of an alkali and dehydrating the condensate is kneaded with a filler, a release agent, and a curing aid to disperse the additives, and the resultant composition is granulated to obtain a resol resin molding material. The resin has a number - average mol.wt. of 600-800 and is liquid at 80-100 deg.C. This molding material is injection-molded to produce a molded article.

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 resol resin molding material and a method for producing a molded product.

[0002]

2. Description of the Related Art A resole resin molding material is a condensate obtained by reacting phenol and formaldehyde in the presence of an alkali, dehydration and cooling to form a solidified product, and the solidified product is pulverized to obtain a powdery resole. A manufacturing method has been adopted in which a resin is obtained, and further, the resol resin, filler, release agent, curing aid, solvent and the like are mixed and dispersed, and granulated by a granulator such as a Henschel mixer. When a molded article is manufactured by injection molding using the resole resin molding material obtained by this method, the melt viscosity is high and the fluidity tends to be poor, and an injection molding machine capable of high-pressure injection molding must be used. However, there was a problem that the cylinder stability was poor and the mold filling property was poor.

[0003]

The present invention has been made in view of the above facts, and an object of the present invention is to produce a resole resin molding material excellent in mold filling property and molding excellent in filling property. It is to provide the manufacturing method of the product.

[0004]

The method for producing a resole resin molding material according to claim 1 of the present invention comprises a condensation reaction of phenol and formaldehyde in the presence of an alkali, followed by dehydration to obtain a resole resin filler, In the method for producing a resole resin molding material that is granulated after being mixed and dispersed with a release agent and a curing aid, the resole resin is a liquid resole resin having a number average molecular weight of 600 to 800 and a temperature of 80 to 100 ° C. It is characterized by

The method for producing a molded article according to claim 2 of the present invention is as follows:
The resole resin molding material obtained by the method for producing a resole resin molding material according to claim 1 is injection-molded to manufacture a molded article.

The present invention will be described in detail below. In the method for producing the resole resin molding material of the present invention, a resol type condensate is obtained by subjecting phenol and formaldehyde to a condensation reaction in the presence of an alkali. The compounding ratio of phenol and formaldehyde is preferably such that the molar ratio F / P of the number F of formaldehyde and the number P of phenol is 1.2 to 2.5. That is, when the molar ratio F / P is less than 1.2, even if the desired resole resin molding material is molded at a high temperature, a curing reaction is difficult to occur.
If it exceeds, gelation tends to occur.

As the alkali used when the phenol and formaldehyde are reacted, a commonly used alkali compound can be applied, and examples thereof include metal hydroxides such as sodium hydroxide or barium hydroxide, or ammonia or hexamethylenetetramine. It is possible to use the organic amine compounds of

Even if the reaction temperature of formaldehyde and phenol is relatively wide, the reaction proceeds, but 80 to 13
0 ° C is desirable.

When the reaction is carried out under such conditions, a resol type condensate can be obtained, but after the reaction, it is dehydrated to give a liquid resol resin. The number average molecular weight of this liquid resol resin by GPC analysis is limited to 600 to 800. That is, when the number average molecular weight of the resole resin is less than 600, the phenol monomer remains, so that when the target resole resin molding material is molded, mold clouding is likely to occur, and when it exceeds 800, the resole resin molding material is When molding to produce a molded product, fluidity,
This is because the cylinder stability and the mold filling property deteriorate.
Since this liquid resol resin exhibits a property of increasing in viscosity as the temperature becomes lower, it is necessary to keep it at 80 to 100 ° C. That is, the liquid resol resin kept at 80 to 100 ° C. can be continuously supplied to the next step of mixing and dispersing the filler, the release agent, and the curing aid. In this mixing and dispersing step, for example, a mixer (trade name; universal mixer) manufactured by Tsukishima Kikai Co., Ltd. is used, and a resole resin is used as a filler,
If necessary, the mixture is mixed and dispersed with a release agent and a curing aid, and then granulated to obtain a resole resin molding material.

Examples of the filler in which the liquid resol resin is mixed and dispersed include wood powder, pulp, cotton powder, silica, calcium carbonate and the like, and examples of the release agent include zinc stearate and calcium stearate. As the curing aid, for example, various metal hydroxides such as alkali compound calcium hydroxide and magnesium hydroxide can be used.

A molding product such as a coil bobbin is obtained by injection-molding the resole resin molding material using an injection molding machine at a mold temperature of about 180 ° C., for example.

[0012]

The method for producing a resole resin molding material according to claim 1 of the present invention comprises a condensation reaction of phenol and formaldehyde in the presence of an alkali, followed by dehydration to obtain a resole resin, which is used as a filler, a release agent and a curing aid. In the method for producing a resole resin molding material that is granulated after being mixed and dispersed with an agent, the resole resin is a liquid resole resin having a number average molecular weight of 600 to 800 and a temperature of 80 to 100 ° C.
Since the liquid resole resin has an appropriate viscosity, it is easy to mix and disperse it with a filler, a release agent and a curing aid, and to produce a molded article by injection molding a resole resin molding material, fluidity, cylinder Good stability.

The method for producing a molded article according to claim 2 of the present invention is
The resole resin molding material obtained by the method for producing a resole resin molding material according to claim 1 is injection-molded to produce a molded product, so that the mold filling property is excellent, and the resulting molded product has good filling property.

[0014]

EXAMPLES The present invention will be specifically described below with reference to examples.

Example 1 80 kg of phenol, 90 kg of 47% by weight formalin and 520 g of zinc acetate were placed in a reaction vessel and reacted at 100 to 120 ° C. for 6 hours, and then this product was dried in a vacuum dehydration vessel. The mixture was heated at 110 ° C. under reduced pressure of 40 Toor for 2 hours for dehydration to obtain a liquid resol resin. The molar ratio F / P of formaldehyde F and phenol P was 1.84. The number average molecular weight of the liquid condensate as determined by GPC analysis was 650. The viscosity of this liquid condensate at 90 ° C. is 40
It was 000 cps. 90% of this liquid resol resin
Leave it in a vacuum dehydrator kept at ℃, 10k of which
The stirring blade (agitator) was put into a mixer (trade name: universal mixer) manufactured by Tsukishima Kikai Co., Ltd. whose temperature was adjusted to 70 ° C. at a low speed of 5 m / s, and then a high speed rotation of 15 m / s was performed. This was carried out for 8 minutes to obtain a resole resin molding material containing almost no fine powder. In addition, a liquid resole resin was added to the filler, the curing aid, and the release agent having the following composition, which were previously mixed in the mixer.

12 kg of wood powder (filler), 7.5 kg of calcium carbonate (filler), 3 kg of cotton powder (filler),
600 g of calcium hydroxide (hardening aid), 500 g of zinc stearate (release agent).

The obtained resol resin molding material had a monoflow of 30 seconds and a disc flow of 85 mm.

The obtained resole resin molding material was injection molded at a mold temperature of 180 ° C. using an injection molding machine equipped with a coil bobbin mold, and a coil bobbin (manufactured by Matsushita Electric Works, Ltd .; product number SB48W20S1) ) Got.

The fluidity and cylinder stability during injection molding were good, and the mold filling property was excellent.

(Comparative Example 1) In the same manner as in Example 1, except that the pulverized product of the resol resin obtained by cooling and pulverizing the liquid resol resin was put into a mixer (trade name; universal mixer) manufactured by Tsukishima Kikai Co., Ltd. , As in Example 1,
A coil bobbin (manufactured by Matsushita Electric Works, Ltd .; product number SB48W20S1) was obtained as a resol resin molding material and a molded product.

The obtained resol resin molding material had a monoflow of 80 seconds and a disc flow of 100 mm. The fluidity and the cylinder stability during injection molding were poor, and the mold filling property was poor.

From the above, it was confirmed that the examples had better cylinder stability and better mold filling property than the comparative examples.

[0023]

According to the method for producing the resole resin molding material according to the first aspect of the present invention, since the liquid resole resin has an appropriate viscosity, it is easy to mix and disperse the filler, the release agent and the curing aid. In the case of producing a molded product by injection molding a resole resin molding material, the fluidity and the cylinder stability are good, and the mold filling property is excellent.

According to the method for producing a molded article according to claim 2 of the present invention, a molded article is produced by injection-molding the resole resin molding material obtained by the method for producing a resole resin molding material according to claim 1, so that a molded article is produced. A mold product having excellent mold filling property and good filling property can be obtained.

Claims (2)

[Claims] 1. A resole resin molding material for granulating after mixing and dispersing a resol resin obtained by condensation reaction of phenol and formaldehyde in the presence of alkali and dehydration with a filler, a release agent and a curing aid. In the method for producing, the resol resin has a number average molecular weight of 600 to 800.
And a method of producing a resole resin molding material, which is a liquid resole resin having a temperature of 80 to 100 ° C. 2. A method for producing a molded article, which comprises producing a molded article by injection-molding the resole resin molding material obtained by the method for producing a resole resin molding material according to claim 1.