JPS587706A - Insulator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Furthermore, KIFPL< uses fine mica scales and an inorganic binder with a specific composition in a specific ratio, so it has good insulation even in a high humidity atmosphere, and has excellent water resistance, heat resistance,
Arc resistance. Excellent mechanical strength and cutting rings, such as arc chutes for arc-extinguishing circuit breakers.

Or it relates to an insulator that can be applied to an arc-resistant insulating ring of a contactor.

Conventionally, this mild insulating material has been made of asbestos bound with phosphoric acid and aluminum phosphate. Although this insulator has thermal shock resistance, it has the disadvantage that its insulation properties deteriorate in a humid atmosphere.

In addition, zircon-based, alumina-based, and magnesia-based porcelain insulators all have good insulation properties and are water resistant and heat resistant in high humidity environments, but they have poor thermal shock resistance and are expensive. It has certain drawbacks.

The present invention provides an insulator that does not have the drawbacks of these conventional insulators, improves the insulation properties and water resistance in a high-humidity atmosphere, and has good heat resistance, arc resistance, thermal shock resistance, mechanical strength, and machinability. The goal is to provide it at a low price.

As a result of intensive research to achieve the above object, the present inventors found that fine mica scales qo-to-weight, preferably jO-
70% by weight, consisting of phosphoric acid and boric acid.

and the weight ratio of P2O, :B,0, is 0.7 to /2,
Preferably 0.7 to 10% by weight of an inorganic binder, preferably 30 to 60% by weight of SO. It has been found that the above object can be achieved. The present invention was completed based on this finding.

The insulator of the present invention can be manufactured as follows.

After stirring and mixing fine mica scales and an inorganic binder consisting of phosphoric acid and boric acid in the form of a wet slurry in the above ratio,
Dry until the moisture content is 70-9%. Charge the dry material into a mold, ioo~/000yu/CC1
It is obtained by shaping at zero pressure and then sintering at too much °C.

The three components of fine mica scales -P2O and -B20° of the insulator of the present invention are located at points A, B, and on the triangular table shown in the drawing.
O.

D, preferably point M' r B' r O', D/
It will be surrounded by. As fine mica scales,
One or two of hard mica, soft mica, and synthetic mica
More than one species can be used, and those that have been made fine by, for example, a water jet are used.

When the content of fine mica scales exceeds 10% by weight, mechanical strength decreases and water absorption increases, resulting in poor water resistance. In addition, if the content is less than the weight, it will easily foam during sintering and will be heat resistant.

Thermal shock resistance deteriorates.

When the bar ratio of P2O5/B2O3 of the inorganic binder is larger than 12, mica-P2 in the vitrified part of the binder
The amount of P2O5 in the O5-B2O5 solid solution increases, and although there is little decrease in mechanical strength, the water soluble content increases and water resistance and insulation properties decrease. Also, s P 205 /B2O
5 is smaller than 0.3, mica-B2O5-820 in the vitrified part of the binder, B20.5 in the solid solution. As the amount of water increases, the water soluble content increases and not only water resistance and insulation properties decrease, but also heat resistance and mechanical strength decrease. In either case, it is not preferred as an inorganic insulator.

The insulating material of the present invention has improved insulation properties under high humidity as shown in the following examples by using a specific ratio of fine mica scales and an inorganic binder consisting of a specific ratio of P2O5 and B20°. , water resistance, heat resistance, arc resistance, thermal shock resistance, and 9 mechanical strength, and can be effectively used as a heat-resistant inorganic insulator for electrical equipment.

Example: Add water as necessary to raw materials with one type of composition below,
After stirring and mixing each mixture for 2 hours using a kneading machine, the mixture was dried until the water content was 70 to 9%, and about Ef of each was charged into a mold, and the mixture was pressurized at room temperature at 300 YU and 70 W2 to shape it. did. This was sintered at 100° C. for 2 hours to create a 9×I5×3D fugenu test piece. The construction of those pillars was as follows.

Notes (1) Insulation resistance, arc resistance 1 bending strength, JIS
Kbu9//.

(2) Heat resistance was determined by the Segelkorn melting method (Ceramic Handbook, p. 13j); (3) Water absorption and water soluble content were determined by soaking the test piece in water for 30 minutes.
This was done by soaking for 1 hour and also by boiling in water for 2 hours.

As the above test results show, the insulator of the present invention has ~ heat resistance and arc resistance, high insulation resistance in a high humidity atmosphere, water absorption rate of <<, and no water soluble content at all. It is water resistant.

[Brief explanation of the drawing]

The drawing shows mica, p2o5 and B20. FIG. 3 is a diagram showing the composition range of the insulator of the present invention having ternary elements. The composition ratios at points A, B, C, D, A', B', O', and D' are as follows.

Claims (1)

[Claims] 1. Fine mica scales o-to weight%, P, O,
:B20. An inorganic binder consisting of phosphoric acid and boric acid with a weight ratio of O, J ~ / 0 - 60 weight C, -
An insulator made of fine mica scales bound together with an inorganic binder.