JP2000226495A - Phenolic resin molding material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a phenolic resin molding material which has high mechanical strengths, good electrical insulating properties and excellent sliding characteristics. SOLUTION: The phenolic resin molding material comprises, as essential ingredients, a high-molecular phenolic novolak resin having a number average molecular weight of 1,000-1,500, a fine powder of a polytetrafluoroethylene resin and a polyimide powder, and contains 5-40 wt.% of the fine powder of a polytetrafluoroethylene resin and 1-5 wt.% of the polyimide powder based on the whole molding material.

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 are 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, although the phenolic resin molding material containing tetrafluoroethylene resin or graphite improves the sliding characteristics, the mechanical strength is remarkably reduced, and particularly, the one containing graphite reduces the electrical insulation property. 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 conducted intensive studies to achieve the above-mentioned object, and as a result, a specific amount of a tetrafluoroethylene resin fine powder and a specific amount of a polyimide powder together with a specific novolak type phenol resin have been obtained. It has been found that by blending, a molding material excellent in mechanical strength, electrical insulation and sliding properties can be obtained, and the present invention has been completed.

That is, the present invention provides a number average molecular weight of 1,000 to 1,000.
1500 novolak-type phenolic resin, tetrafluoroethylene resin fine powder and polyimide powder as essential components, 5 to 40% by weight of said tetrafluoroethylene resin fine powder relative to the whole molding material, said polyimide powder Is contained at a ratio of 1 to 5% by weight, respectively.

Hereinafter, the present invention will be described in detail.

The novolak type phenol resin used in the present invention includes phenols such as phenol and cresol, or phenols modified with molasses, lignin, xylene, naphthalene and petroleum aromatic hydrocarbons.
Aldehydes such as formalin, paraform, etc.
A number average molecular weight of from 1,000 to 1,500, preferably from 1 to 9, in a molar ratio of 0.90 and reacted under an acidic catalyst such as oxalic acid.
A phenol novolak resin of 200 to 1400,
This is used in the molding material formulation in the state of the initial condensate in which the dehydration step is omitted. It is desirable to mix the phenolic resin such that the resin content is 0.1 to 70% by weight based on the entire molding material, and more preferably 30 to 70% by weight.
60% by weight. If this ratio is less than 0.1% by weight,
There is no effect of improving the mechanical strength and the electrical properties, and if it exceeds 70% by weight, it becomes difficult to produce a molding material by a dry method, which is not preferable.

The fine particles of the ethylene tetrafluoride resin used in the present invention preferably have an average particle size of 10 to 50 μm and a maximum particle size of 50 to 100 μm. More preferably, the average particle size is 20 to 40 μm, and the maximum particle size is 60 to 80 μm.
m. The molecular weight of the tetrafluoroethylene resin fine powder is not particularly limited.

The compounding amount of the fine powder of tetrafluoroethylene resin 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. In addition, 40% by weight
If it exceeds, the sliding characteristics are improved, but the mechanical strength is inferior, which is not preferable.

The particle size of the polyimide powder used in the present invention is 500 μm or less, preferably 200 μm or less, from the viewpoint of dispersibility.

The mixing ratio of the polyimide powder must be 1 to 5% by weight based on the whole molding material. If it is less than 1% by weight, the compounding effect on the sliding properties is small, and if it exceeds 5% by weight, when it is made into a molding material, it is not easy to disperse, resulting in poor appearance of the molded article.

The phenolic resin molding material of the present invention contains the above-mentioned phenolic resin, fine powder of tetrafluoroethylene resin and polyimide powder as essential components, but within the scope not inconsistent with the object of the present invention, and if necessary, For example, inorganic fillers such as calcium carbonate, clay and talc, natural waxes, synthetic waxes, metal salts of linear fatty acids, release agents such as acid amides, esters and paraffins, paraffin chloride, bromotoluene, and hexane Flame retardants such as bromobenzene and antimony trioxide, curing agents such as hexamethylenetetramine, and various curing accelerators can be appropriately added and blended.

The phenolic resin molding material of the present invention is usually produced as follows. The above-mentioned novolak-type phenol resin, tetrafluoroethylene resin fine powder, polyimide powder and other additives are added and mixed as necessary, and then uniformly dispersed. Then, the mixture is heated and kneaded with a kneader, and then cooled and solidified. And pulverized to an appropriate size to obtain a molding material.

[0015]

The phenolic resin molding material of the present invention uses a high molecular weight novolak type phenolic resin,
Although the slidability was improved with the fine powder of tetrafluoroethylene resin and polyimide powder, it was possible to obtain excellent mechanical strength.

[0016]

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 1 Novolak type phenol resin 5 having a number average molecular weight of 1300
0%, 8% hexamine, fine powder of tetrafluoroethylene resin 1
5%, 3% of polyimide powder, 12% of wood flour, 5% of calcium carbonate, and 7% of other additives were mixed at room temperature, kneaded with a hot roll, cooled, and then pulverized to produce a phenolic resin molding material. .

Comparative Example 1 Novolak type phenol resin 50 having a number average molecular weight of 700
%, Hexamine 8%, fine powder of tetrafluoroethylene resin 15
%, Polyimide powder 3%, wood flour 12%, calcium carbonate 5%, and other additives 7% were mixed at room temperature, kneaded with a hot roll, cooled, and then pulverized to produce a phenolic resin molding material.

Comparative Example 2 Novolak type phenol resin 5 having a number average molecular weight of 1300
0%, 8% hexamine, fine powder of tetrafluoroethylene resin 1
8%, 12% of wood flour, 5% of calcium carbonate, and 7% of other additives were mixed at room temperature, kneaded with a hot roll, cooled, and then pulverized to produce a phenolic resin molding material.

Comparative Example 3 Novolak type phenol resin 5 having a number average molecular weight of 1300
0%, Hexamine 8%, Graphite powder 15%, Polyimide powder 3%, Wood flour 12%, Calcium carbonate 5
%, And 7% of other additives were mixed at room temperature, kneaded with a hot roll, cooled, and then pulverized to produce a phenolic resin molding material.

The phenolic resin molding materials produced in Example 1 and Comparative Examples 1 to 3 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. Table 1 shows the results.
It exhibited excellent properties and well-balanced properties, confirming the effects of the present invention.

[0022]

[Table 1]

[0023]

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.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor, Noriyuki Nakajima 5-14-25 Ryoke, Kawaguchi City, Saitama Prefecture Toshiba Chemical Corporation Kawaguchi Plant F-term (reference) 4J002 BD152 CC041 CM043 FD010 FD130 FD140 FD160

Claims (1)

[Claims] 1. A novolak-type phenol resin having a number average molecular weight of 1,000 to 1,500, a fine powder of tetrafluoroethylene resin and polyimide powder as essential components, and the fine powder of tetrafluoroethylene resin is added to the entire molding material in an amount of 5 to 5 parts. ~
A phenolic resin molding material containing 40% by weight of the polyimide powder and 1 to 5% by weight of the polyimide powder.