JPH11189703A - Phenol resin molding material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject molding material having excellent mechanical properties, electrical insulating properties and sliding characteristics by including specific amounts of a phenol novolak resin and fluorinated ethylene resin fine powder. SOLUTION: This phenol resin molding material comprises (A) a phenol novolak resin having 10,000-50,000 weight-average molecular weight and (B) tetrafluoroethylene resin fine powder as essential components in the ratio of 0.1-40 wt.% of based on the total molding material of the component B. The component A is obtained by formulating and reacting a phenol with an aldehyde in the molar ratio to the aldehyde of 0.85-0.90 in the presence of an acidic catalyst such as oxalic acid or the like and preferably 30-60 wt.% of the component A is mixed with the total of the molding material. Preferably the component B has 20-40 μm average particle diameter and 60-80 μm maximum particle diameter. The molding material can be optionally compounded with an inorganic filler such as calcium carbonate, clay, talc or the like and a natural wax.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phenol resin molding material having excellent mechanical, electrical and sliding properties.

[0002]

2. Description of the Related Art Conventionally, molded parts obtained by molding a phenolic resin molding material containing a substance having excellent sliding properties, such as tetrafluoroethylene resin and graphite, have excellent sliding properties and have been used as mechanical parts. Have been. And
With the intention of improving the strength of components used, demands for higher strength have been increasing, and materials having excellent electrical insulation properties have been desired.

[0003] Although a high-strength phenolic resin molding material filled with glass fibers at a high level is on the market, it has a problem in sliding characteristics. That is, although the mechanical strength is improved by highly filling the glass fiber, the sliding characteristics are reduced, and it is very difficult to achieve both the mechanical strength and the sliding characteristics. In addition, the phenolic resin molding compound containing tetrafluoroethylene resin or graphite improves the sliding characteristics, but the mechanical strength is remarkably reduced.Especially, the compound containing graphite also decreases the electrical insulation. It was difficult to meet the aforementioned requirements.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is a phenolic resin molding material having high mechanical strength, good electrical insulation, and excellent sliding properties. It is intended to provide.

[0005]

Means for Solving the Problems The inventors of the present invention have made intensive studies to achieve the above-mentioned objects, and as a result, together with a phenol novolak resin having a weight average molecular weight of 10,000 to 50,000.
4 It has been found that a molding material excellent in mechanical strength, electrical insulation and sliding properties can be obtained by mixing a specific amount of fine powder of fluoroethylene resin, and the present invention has been completed.

[0006] That is, the present invention provides a method for preparing a weight-average molecular weight of 10,000-
A phenol resin characterized by comprising 50,000 phenol novolak resin and fine powder of tetrafluoroethylene resin as essential components, and containing 0.1 to 40% by weight of the fine powder of tetrafluoroethylene resin with respect to the whole molding material. It is a molding material.

Hereinafter, the present invention will be described in detail.

The phenol novolak resin used in the present invention includes phenols such as phenol and cresol;
Alternatively, aldehydes such as formalin and paraform are blended in a molar ratio of 0.85 to 0.90 with respect to phenols modified by molasses, lignin, xylene, naphthalene and petroleum aromatic hydrocarbons, and reacted under an acidic catalyst such as oxalic acid. It is a phenol novolak resin having a weight-average molecular weight of 10,000 to 50,000, preferably 30,000 to 40,000, which is used for compounding a molding material in the state of an initial condensate without a dehydration step. It is desirable that the phenolic resin is blended so as to contain 0.1 to 70% by weight, more preferably 30 to 60% by weight, based on the whole molding material. This ratio is 0.
If the amount is less than 1% by weight, there is no effect of improving the mechanical strength and the electrical properties, and if it exceeds 70% by weight, it is difficult to produce a molding material by a dry method, which is not preferable. In addition to the phenol novolak resin, a novolak phenol resin having a weight-average molecular weight of less than 10,000 can be used as needed. However, it is preferred that the phenol novolak resin does not exceed 70% by weight, based on the total molding material.

The fine powder of tetrafluoroethylene resin used in the present invention has an average particle diameter of 10 to 50 μm and a maximum particle diameter of 50 to 50 μm.
Desirably, it is 100 μm. More preferably, the average particle size is 20 to 40 μm, and the maximum particle size is 60 to 80 μm. 4 The molecular weight of the fluorinated ethylene resin fine powder is not particularly limited.

4 The compounding amount of the fluorinated ethylene resin fine powder is as follows:
It is necessary to contain 0.1 to 40% by weight with respect to the whole molding material, and more preferably, it is in the range of 10 to 30% by weight. If the compounding amount is less than 0.1% by weight, the sliding characteristics deteriorate, which is not preferable. On the other hand, if it exceeds 40% by weight, the sliding characteristics are improved, but the mechanical strength is poor, which is not preferable.

[0011] The phenolic resin molding material of the present invention contains the above-mentioned phenolic resin and fine powder of tetrafluoroethylene resin.
If necessary, for example, calcium carbonate, clay,
Inorganic fillers such as talc, natural waxes, synthetic waxes, metal salts of linear fatty acids, mold release agents such as acid amides, esters, paraffins, paraffin chloride, bromtoluene, hexabromobenzene, antimony trioxide, etc. , A curing agent such as hexamethylenetetramine, various curing accelerators, and the like can be appropriately added and blended.

The phenolic resin molding material of the present invention is usually manufactured as follows. After adding and mixing the above-mentioned phenol resin, fine powder of tetrafluoroethylene resin and other additives as necessary, and uniformly dispersing,
The mixture is heated and kneaded by a kneader, then solidified by cooling and pulverized to an appropriate size to obtain a molding material.

[0013]

The phenolic resin molding material of the present invention uses a high-molecular-weight phenol novolak resin,
Despite improving the slidability with the fine powder of the fluorinated ethylene resin, excellent mechanical strength could be obtained.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described specifically by way of examples, but the present invention is not limited to the following examples. Hereinafter, “%” means “% by weight” unless otherwise specified.

Example 50% of a water-containing initial condensate of a phenol novolak resin having a weight average molecular weight of 38,000 (resin content), 8% of hexamine, 15% of fine powder of tetrafluoroethylene resin, 15% of wood flour, calcium carbonate
5% and 7% of other additives were mixed at room temperature, kneaded with a hot roll, cooled, and pulverized to produce a phenolic resin molding material.

Comparative Example 1 Phenol novolak resin 50 having a weight average molecular weight of 6,000
%, Hexamine 8%, tetrafluoroethylene resin fine powder 15
%, Wood flour 15%, calcium carbonate 5%, other additives 7%
Were mixed at room temperature, further kneaded with a hot roll, cooled, and then pulverized to produce a phenolic resin molding material.

Comparative Example 2 50% of a dehydrated phenol novolak resin having a weight average molecular weight of 38,000, 8% of hexamine, 15% of graphite powder,
15% of wood flour, 5% of calcium carbonate and 7% of other additives were mixed at room temperature, kneaded and cooled by an extruder, and then pulverized to produce a phenolic resin molding material.

The phenolic resin molding materials produced in Examples and Comparative Examples 1 and 2 were molded and cured in a mold heated to 170 ° C. by injection molding to obtain molded parts. The obtained molded parts were tested for mechanical properties, electrical properties, and coefficient of friction. The results are shown in Table 1. As shown in the table, the present invention was excellent in various characteristics and exhibited well-balanced characteristics, thereby confirming the effects of the present invention.

[0019]

[Table 1]

[0020]

As is apparent from the above description and Table 1, the phenolic resin molding material of the present invention is excellent in slidability while maintaining high mechanical strength and electrical characteristics.

Claims (1)

[Claims] A phenol novolak resin having a weight average molecular weight of 10,000 to 50,000 and a fine powder of tetrafluoroethylene resin as essential components, and a ratio of the fine powder of tetrafluoroethylene resin of 0.1 to 40% by weight to the whole molding material. A phenolic resin molding material characterized by containing