JP2001207017A - Phenol resin molding material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a granulated phenol resin molding material excellent in resistances to impact, tracking, and wear. SOLUTION: This granulated phenol resin molding material is characterized in that it comprises 40-60 wt.% of a resol type phenol resin, 30-50 wt.% of pulverized cotton fabric, and 5-15 wt.% of inorganic powder and that it is prepared by melt mixing in a high-speed agitation mixer such as a Henschel mixer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a granular phenolic resin molding material having excellent impact strength, tracking resistance and abrasion resistance.

[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. In particular, recently, the demand for the reliability of products has become strict, and electric performance such as tracking resistance has been demanded.

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

Furthermore, electric 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. Conventionally, a granular novolak type phenol resin molding material having high impact resistance and abrasion resistance has been used for these parts, but cannot be used for parts requiring reliability because of its low tracking resistance.

[0005]

The present invention has been made as a result of various studies to solve such problems of the conventional granular phenolic resin molding material. Another object of the present invention is to provide a granular phenolic resin molding material having excellent tracking resistance and abrasion resistance.

[0006]

According to the present invention, a resol type phenol resin is used in an amount of 40 to 60% by weight and a crushed cotton fabric is used in an amount of 30% by weight.
The present invention relates to a granular phenolic resin molding material, which comprises about 50% by weight and 5 to 15% by weight of a powdery inorganic filler and is melt-mixed by a high-speed stirring mixer.

The shape of the phenolic resin molding material of the present invention is granular. A general phenolic resin molding material is a granular material obtained by kneading with a twin-screw roll or the like and then pulverizing, but since the molding material of the present invention is kneaded with a Henschel mixer, the resin content is evenly distributed on the pulverized cloth. Coated, corner-free granular shape. A material obtained by kneading and pulverizing the compounding formulation of the present invention with a twin-screw roll cannot be used because the apparent density becomes small due to the separation of the pulverized cotton fabric from the resin component.

The resole type phenol resin used in the present invention is used for ordinary molding materials, and dimethylene ether type resole resin, methylol type phenol resin and the like can be used. The purpose is to have higher tracking resistance than a novolak type phenol resin. If necessary, a novolak-type phenol resin can be used in combination, but the tracking resistance is lowered, so that it is preferably 10% or less of the whole composition. The compounding amount of the resole type phenol resin is 40 to 60 of the whole composition.
% By weight is preferred. If the amount is less than 40% by weight, good granularity will not be obtained. If the amount exceeds 60% by weight, the tracking resistance will decrease, and the cost of the molding material will increase, leading to a reduction in practicality.

The pulverized cotton fabric used in the present invention may be one usually used for a phenolic molding material, and the purpose is to improve impact resistance and abrasion resistance. Movable parts such as electric parts, especially magnet switches, have collisions with the contact parts more than tens of thousands of times, and are required to have higher impact strength and wear resistance than general-purpose phenolic resin. Since the crushed cotton fabric has excellent impact resistance, low ash content, and excellent abrasion resistance, it is indispensable to add a crushed cotton fabric. The crushed cotton fabric is 3% of the total composition.
0 to 50% by weight is preferred. If it is less than 30% by weight, the impact resistance is reduced, and if it exceeds 50% by weight, the moldability is reduced and the apparent density is reduced.

In the present invention, a powdery inorganic filler is used for improving tracking resistance. The inorganic filler has higher tracking resistance than organic fillers such as organic powders and the above-mentioned crushed cotton fabric. A phenolic resin molding material mainly containing a resin and a crushed cotton fabric is used without using an inorganic filler in a member that does not require tracking resistance. The compounding amount of the inorganic filler is 5 to 15 of the whole composition.
% By weight is preferred. If the amount is less than 5% by weight, the tracking resistance decreases, and if it exceeds 15% by weight, the abrasion resistance decreases.
As a powdery inorganic filler, silica, alumina, glass,
Talc, clay and the like can be mentioned, and one or more kinds can be used. Inorganic fillers having water of crystallization such as talc and unfired clay are preferable because they have good tracking resistance and are effective in small amounts. As other fillers, various additives such as a lubricant, a curing accelerator, and a flame retardant can be appropriately compounded.

The phenolic resin molding material of the present invention can be produced by blending a phenolic resin component, a filler and other additives, and melt-mixing the mixture with a high-speed stirring mixer such as a Henschel mixer.

[0012]

The present invention will be described below in more detail with reference to examples. In Table 1, the composition described in the upper column was melt-mixed at 80 ° C. with a Henschel mixer to obtain a molding material.

[0013]

[Table 1]

(Measurement Method) All test pieces were formed by transfer molding at 175 ° C. for 3 minutes. 1. The Charpy impact strength was measured according to JIS K 6911. 2. The tracking resistance was measured according to JIS C 2134. 3. The wear resistance was measured by sliding two molded products (10 × 4t and φ18 × 10) under the conditions of a load of 3 kgf, a peripheral speed of 60 rpm, and 24 hours.

[0015]

According to the granular phenolic resin molding material of the present invention, the molded article obtained therefrom is excellent in impact resistance, tracking resistance and abrasion resistance, and electric and electronic parts, in particular, which are required to have these characteristics. It is suitable for movable contact parts such as magnet switches.

Claims (1)

[Claims] 1. A resol-type phenolic resin of 40 to 60.
A granular phenolic resin molding material, comprising 30% to 50% by weight of a crushed cotton fabric and 5 to 15% by weight of a powdered inorganic filler, and melt-mixed by a high-speed stirring mixer.