JPH11166100A - Phenol resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain both a phenol resin composition excellent in dielectric breakdown strength and tracking and abrasion resistances, and a molding material using the phenol resin composition. SOLUTION: This phenol resin composition contains 25-35 wt.% of a resol type phenol resin and >=40 wt.%. of an inorganic filler releasing water of crystallization at >=200 deg.C as a flame retardant component in the composition. At least one kind thereof is an inorganic filler releasing >=20 wt.% water of crystallization at 200 deg.C and contained in an amount of >=10 wt.% in the whole composition. Furthermore, an aramid chopped polymer having <=500 μm average particle diameter as an abrasion resistant component is contained in an amount of 1-3 wt.% in the whole composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phenolic resin composition excellent in dielectric strength, tracking resistance, flame resistance, and abrasion resistance, and a molding material using the same.

[0002]

2. Description of the Related Art Phenolic resin molding materials are excellent in heat resistance, dimensional stability, moldability and the like, and have been used for a long time in basic industrial fields such as automobiles, electricity and electronics. Particularly in recent years, the demands for the reliability of products have become strict, and electric performances such as dielectric strength and tracking resistance have been demanded.

[0003] Usually, for parts requiring electrical performance, resins having excellent electrical properties such as unsaturated polyester, diallyl phthalate, melamine, and melamine phenol resin are often used, but heat resistance, moldability, cost, etc. There is also a problem, and it is desired to impart higher tracking resistance, dielectric strength, flame resistance, and abrasion resistance while maintaining excellent heat resistance and moldability of the phenolic resin molding material.

[0004] Electrical parts, especially movable parts such as magnet switches, have problems of contact contamination and malfunction due to generation of wear powder, and are also required to have wear resistance.

[0005] The characteristics of a molding material using a resol type phenolic resin are that, in addition to not generating ammonia gas from the molded product, the ionic impurities of the contained inorganic filler are suppressed to a low level, and the electrical properties, particularly the moisture resistance and the dielectric breakdown strength, are reduced. That is good. Generally, a pulverized product of a laminate, an inorganic filler, and the like are often used, but on the other hand, there is a problem in that the abrasion resistance of the molded product is reduced, and thus, it is not always satisfactory.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been made as a result of various studies to solve such problems of the conventional resol-type phenolic resin composition or resol-type phenolic resin molding material. It is an object of the present invention to provide a phenol resin composition and a molding material having excellent tracking resistance, dielectric breakdown strength, flame resistance, and abrasion resistance.

[0007]

According to the present invention, an inorganic filler containing 25 to 35% by weight of a resole type phenol resin and releasing crystallization water at a temperature of 200 ° C. or higher as a flame retardant component is contained in a composition of 40 to 70%. At least one of them is an inorganic filler which releases at least 20% by weight of water of crystallization at 200 ° C., which contains at least 10% by weight in the total composition, and further has a wear-resistant component. Average particle size 500 μm
The following aramid chopped polymer is contained in the composition in an amount of 1 to 3
The present invention relates to a phenol resin composition characterized by containing by weight, and a molding material using the same.

[0008] The resol type phenol resin used here is one used for ordinary molding materials, and dimethylene ether type resole resin, methylol type resole resin and the like can be used. If necessary, a novolak-type phenol resin can also be used in combination. However, it is preferable not to use hexamethylenetetramine as a curing agent from the viewpoints of deterioration of moisture resistance and electric characteristics due to generation of ammonia from a molded product. The amount of phenolic resin was 25% of the total composition.
The content is preferably from 35% by weight to 35% by weight. If it is less than this, the wettability with the base material is not sufficiently obtained, and the strength is reduced and the moldability is reduced due to insufficient flow. On the other hand, if it exceeds this, the tracking resistance will decrease, and the cost of the material will increase, and the practicability will be lacking.

The filler used as the flame retardant component is an inorganic filler that releases water of crystallization at 200 ° C. or higher. 40-70% by weight in the composition, preferably 45-6%
It is necessary to contain 5% by weight. Such fillers include zinc borate, calcium borate, talc, unfired clay, and the like. At least one of them is an inorganic filler that releases 20% by weight or more of crystallization water at 200 ° C., and it is necessary to use 10% by weight or more based on the total composition. Examples of such a filler include aluminum hydroxide and magnesium hydroxide. If the total amount of the inorganic filler as a flame-retardant component is less than 40% by weight, sufficient tracking resistance cannot be obtained. If the total amount exceeds 70% by weight, it becomes difficult to mix uniformly. If not more than 10% by weight of the inorganic filler to be released is used in the whole composition, there is a problem that sufficient flame resistance cannot be obtained.

The aramid chopped polymer used as the abrasion-resistant component is obtained by finely pulverizing a resin that forms aramid fibers, and has an average particle diameter of 500 μm or less.
Preferably, those having a size of 200 μm or less are used. If the particle size is larger than this, there is a problem that sufficient dispersibility cannot be obtained and the strength of the molded article is reduced. Further, the addition amount is preferably 1% by weight or more and 3% by weight or less. If it is less than 1% by weight, sufficient wear resistance cannot be imparted, and 3% by weight
When it exceeds, although the abrasion resistance is good, sufficient wettability is not obtained and strength is lowered, and the method is not practical and costs increase. The commercially available aramid chopped polymer is Twaron 500 from Nippon Aramid Co., Ltd.
3, Twaron 5010 and the like.

As other fillers, pulverized cloth, pulverized powder of laminated board, and pulverized powder usually used for resol type phenol resin are used.
Although calcined clay and calcium carbonate are used, those having less ionic impurities are more desirable from the viewpoint of electrical characteristics.

The molding material obtained from the phenolic resin composition of the present invention is suitable for electric contact parts such as electric switches and electronic parts, especially magnet switches, which require dielectric strength, tracking resistance and abrasion resistance. .

The phenolic resin molding material of the present invention is prepared by adding a mold release agent, a curing accelerator, etc., which are used for a general phenolic resin molding material, in addition to the above composition, uniformly mixing these raw materials, The mixture is heated and kneaded by a kneader such as a kneader, a co-kneader or a twin-screw extruder, and then pulverized.

[0014]

EXAMPLES Table 1 shows Examples and Comparative Examples. The mixture was heated and kneaded with a usual two-roll mill in the composition described in the above column to obtain a molding material. The molded article characteristics of these molding materials were measured, and the results shown in the lower column of Table 1 were obtained.

[0015]

[Table 1]

[0016]

According to the phenolic resin composition and the phenolic resin molding material of the present invention, the molded article obtained therefrom is excellent in heat resistance, dielectric strength, tracking resistance and abrasion resistance, and these characteristics are required. It is suitable for electric and electronic parts, especially movable contact parts such as magnet switches.

Claims (3)

[Claims] 1. The method according to claim 1, wherein the resole type phenol resin is 25-35.
The composition contains 40 to 70% by weight of an inorganic filler that releases water of crystallization at 200 ° C. or higher as a flame retardant component, and at least one of them contains 20% at 200 ° C.
It is an inorganic filler that releases 10% by weight or more of crystallization water, contains 10% by weight or more of the entire composition, and further contains an aramid chopped polymer having an average particle size of 500 μm or less as a wear-resistant component in the composition. A phenol resin composition characterized by containing by weight. 2. The phenolic resin composition according to claim 1, wherein hexamethylenetetramine is not contained as a curing agent. 3. A phenolic resin molding material containing the phenolic resin composition according to claim 1 as an essential component.