JP3256007B2 - Method for producing phenolic resin molding material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a phenol which does not generate dust because the glass fiber in the molding material remains for a long time, the adhesion to the resin is improved, the static strength and the impact strength are both balanced. The present invention relates to a method for producing a resin molding material.

[0002]

2. Description of the Related Art Conventionally, phenolic resin molding materials have been:
Because of its excellent cost performance such as heat resistance, mechanical strength characteristics, and electrical properties, it is used in a wide range of industrial fields such as automobiles, electricity, and machinery. Conventional phenolic resin molding material is a mixture of resin and glass fiber and compounding raw materials such as filler, curing agent, release agent, and coloring agent.
It is a general manufacturing method to knead the mixture by pressurizing and heating with a kneading device such as a kneader or a screw extruder, and to process the mixture into a shape and size suitable for molding.

[0003] In such a conventional production method, when kneaded with a roll kneader, fine powder is generated due to pulverization into crushed granules, and dust is scattered at the time of use, which is not preferable in terms of environmental hygiene. For this reason, a thermosetting material without fine powder is granulated by using a kneader or a screw extruder, and a part thereof is also manufactured and used. In any case, the glass fiber is broken and shortened in the kneading step of pressing and heating, so that the glass fiber remaining in the molding material is extremely short regardless of the initial length. As a result, there is a limit to the improvement of heat resistance and mechanical strength by glass fibers.

[0004]

SUMMARY OF THE INVENTION The present invention has been completed as a result of various studies to solve the above-mentioned problems in the conventional glass fiber / phenolic resin molding material. Leave the glass fiber long,
It is an object of the present invention to provide a dust-free phenolic resin molding material which has an excellent balance between static strength and dynamic strength by enhancing the adhesion between a resin and glass fiber and which does not adversely affect environmental hygiene such as air pollution.

[0005]

According to the present invention, 5 to 30 parts by weight of water is added to a compounded composition containing 100 to 250 parts by weight of glass fiber with respect to 100 parts by weight of a phenol resin, and kneaded. Characterized by granulation with an extrusion granulator
Of dust-free phenolic resin molding material
Production method. It is about. Hereinafter, the present invention will be described in detail. The present invention can be applied to a novolak-type phenolic resin or a resol-type phenolic resin, and any phenolic resin molding material. The blended composition is based on 100 parts by weight of phenolic resin and 100 parts by weight of glass fiber as filler.
-250 parts by weight, and if necessary, one or more inorganic fillers such as magnesium hydroxide, aluminum hydroxide, silica, or silicate minerals such as clay and mica, and are used as a molding material. Therefore, a curing agent, a release agent, a coloring agent, a glass surface treatment agent, and the like are usually added to the above components.

Further, in the present invention, water is uniformly dispersed in the above composition at a ratio of 5 to 30 parts by weight with respect to 100 parts by weight of the phenol resin, and then the mixture is kneaded with a kneading apparatus such as a roll, kneader or screw extruder. It is made into a molding material by kneading. The screw extruder can use either a single screw or a twin screw. Water can be added by spraying the mixture while stirring it in a mixer, or by uniformly adding the glass fiber and filler alone or in a mixture, and then mixing with resin or other components, or pressurizing in the barrel zone of a screw extruder. This is done by injection.
If you use a granulation method in which a granulator is inlined with a screw extruder or a single-screw extruder, a granular dust-free phenol resin molding material that does not generate fine powder is economically efficient,
It can be obtained in high yield.

As described above, the amount of water added is 5 to 30 parts by weight based on 100 parts by weight of the phenol resin. If the amount of water is less than 5 parts by weight, the melt viscosity is high and the glass fibers are significantly broken. If the amount exceeds 30 parts by weight, the material conveying efficiency in the screw extruder or the single-screw granulator decreases, which is not economical and has a bad influence on the characteristics of the molded product. The phenolic resin molding material obtained from such a compound is capable of accurately controlling the temperature of the material discharged from the granulator to 90 to 105 ° C.
The length of the glass fiber in the molding material is 400 to 800 μm
It is much longer than the conventional method, and its fluidity is stable, so it has good moldability and high heat resistance and mechanical properties.
Demonstrate strength . Thus, for the first time in the present invention,
It has become possible to provide a dust-free phenolic resin molding material without impairing economic efficiency.

[0008]

EXAMPLES (Blending Composition of Phenolic Resin Molding Material) Phenol Resin (Resol Type) 100 parts by weight Glass fiber 160 Clay 10 Slaked lime 10 Stearic acid 6 Carbon black 6 The above blending composition is a comparative example, and is an example. Is the basis of the formulation. All components are commercial products. The glass fiber used was E glass having a diameter of 10 μm and a cut length of 3 mm. The kneading and granulation of the compounded composition were performed in an in-line process using a commercially available twin-screw extruder and a single-screw granulator.

In Comparative Example 1, kneading and granulation were performed in the above-described steps according to the above-mentioned composition. Since the melting torque was high, the screw rotation speed was limited and it was difficult to increase the speed. The length of the glass fiber in the molding material is as short as 50 μm. The Charpy impact strength in this case was 0.35 J / cm. In Example 1, a phenol resin was added to the above composition.
5 parts by weight of water was added to 100 parts by weight , and kneading and granulation were performed in the same steps as in the comparative example. Granulation could be carried out without any problems. The results shown in Table 1 were obtained. In Example 2, the amount of water added was increased to 15 parts by weight in the same manner as in Example 1, and granulation was performed in the same steps as in Comparative Example. Example 1
As in the case above, granulation could be performed without any problem. In Example 3, the amount of water added was further increased to 25 parts by weight as compared with Example 2, and granulation was performed in the same process as in Comparative Example. As in Example 1, granulation could be performed without any problem.

[0010]

[Table 1]

(Test method) Glass fiber length in molding material:
About 2 g of the molding material was converted into ash which was heated in an electric furnace at a temperature of 700 ° C., and this was magnified 50 times with a microscope, a photograph was taken, the length of the glass fiber was measured on the photograph, and the average fiber length was measured. I asked. Melting torque: Labo Plastmill / Plastcorder manufactured by Toyo Seiki Co., Ltd., temperature 100 ° C, mixer rotation speed 30
rpm. Mechanical strength: According to JIS K 6911. The test piece was manufactured by transfer molding.

[0012]

As is clear from the above examples, the phenolic resin molding material obtained according to the present invention is a dust-free granular molding material and has an appropriate melting torque during molding. Good nature. Since the glass fiber length in the molding material is long, the mechanical strength is also excellent.

Claims (1)

(57) [Claims] An extruded granulation is obtained by adding and mixing 5 to 30 parts by weight of water to a composition containing 100 to 250 parts by weight of glass fiber with respect to 100 parts by weight of a phenol resin.
Granular dust-free, characterized by granulation by equipment
・ Method of manufacturing phenolic resin molding material.