DE2806663A1 - Hardenable resin compsn. for arc extinguishing materials - comprises a polyacetal and an unsatd. polyester resin - Google Patents

Abstract

A heat hardenable resin compsn. for arc extinguishing materials comprises a finely divided polyacetal (I) and a hardenable cpd. (II) esp. an unsatd. polyester. The compsn. pref. comprises 10-300 (20-250) wt. % (I) and 100 wt. % (II). The compsn. has a strong arc extinguishing effect and good dimensional stability under arcing and may be used in switches and cut out devices.

Description

Thermosetting compound

The priority of the Japanese patent application dated February 19, 1977 with the File number 17307/77 is used.

The invention relates to a thermosetting composition for arc extinguishing Material.

Heat-curable masses produce thermosetting plastics when cured, in other words, cross-linked plastics.

In electrical devices for switching electrical circuits takes place under load, for example in circuit breakers or switches switching mostly by mechanical means. There are numerous switching mechanisms with diverse procedures for extinguishing the arc, with the most varied Materials are used.

Materials such as those used for the housings of electrical switchgear facilities are required, should support the switching process and prevent re-ignition of the Secure the arc. Such materials are said to be under the action of an electric arc or at high temperatures release gases that support arc extinction0 The material should not change either in its structure or in its shape change in an undesirable way. The material should therefore have the required properties and, on the other hand, can be shaped by machine using injection molding technology.

Glass fibers and melamine resins are used as arc-extinguishing materials especially used for relatively low voltages and small currents. At high voltages and high currents, these materials have the disadvantage that they can only slightly support the arc extinguishing and char easily. When charring, they lose their original shape and they become under the action of the arc deteriorated in their properties to the point of uselessness.

On the other hand, materials such as ceramics or bricks are used from a variety of thermosetting resin compositions containing large amounts of inorganic fillers can be added to obtain materials that retain their shape. Such materials however, they have another disadvantage: they can only give off small amounts of gas and therefore often do not support switching in the desired manner. Other such Materials are not suitable for practical use.

The invention is based on the object of a thermosetting composition to develop, while avoiding the disadvantages described for arc extinguishing material suitable, which is strongly gas-emitting, but shape and properties when used in Switching devices such as miniature circuit breakers also under higher voltage and larger Maintains currents, but on the other hand already at low voltages and small ones Currents is effective.

The object described is achieved according to the invention in that a polyacetal compound in finely divided form of a thermosetting compound is admitted. This resin compound is suitable for arc extinguishing material Requirements such as those made for electrical switching devices such as miniature circuit breakers will.

The thermosetting resin composition can be easily produced by a Polyacetal compound in powder form or as granules of a thermosetting compound is optionally admixed together with customary fillers. As a thermosetting Connection are conventional thermosetting compounds offered on the market, which were already in use for arc-extinguishing material. Particularly suitable such thermosetting compounds known to be arcing keep their shape. The resin composition according to the invention, the cheap Properties, however, unexpectedly strongly promoted.

An unsaturated compound is advantageously used as the thermosetting compound Related to polyester compound. But there are also epoxy resins, silicones and Dialiyl phthalates and phenolic resins. Mixtures of such resins are also suitable.

It is favorable to add 10 to 300 percent by weight of the polyacetal compound 100 percent by weight of a thermosetting Compound in finely divided Admit form. 20 to 250 percent by weight are particularly advantageous.

A molded body can then be made from such a resin composition in the usual manner getting produced.

A polyacetal compound is suitable for the resin composition according to the invention, as is available on the market, for example high molecular weight polyoxymethylene. 10 to 300 percent by weight of the polyacetal compound, preferably 20 to 250 percent by weight are added to 100 percent by weight of the thermosetting compound.

The production of arc-extinguishing material can be varied with the addition common fillers: Inorganic fillers such as silica, i.e. silicon dioxide, aluminum oxide, aluminum oxide hydrate, calcium carbonate or calcium sulfate. Glass fibers or spun glass fiber material are suitable as reinforcement materials (glass chopped strand). As a release agent to prevent it from being released from an injection mold Additives such as zinc stearate are suitable to make it easier or, if necessary, as plasticizers. Finally, you can use a free radical catalyst, for example Add benzoyl peroxide, in the case of a thermosetting compound made from diallyl phthalate. If epoxy resin is used, a commercially available hardener for epoxy resins is used to.

The thermosetting resin composition gives moldings with surprisingly strong arc-extinguishing effect, which also changes its shape under the action of the arc maintained.

Practical experiments using self-switches, which are known as Miniature circuit breakers are common, have when using the thermosetting Resin mass produced material: the insulation resistance between the arc extinguishing plates is larger after switching than 100 Mn and the material is hardly attacked. Such attempts also show the Superiority of the material in terms of arc resistance, tracking resistance and temperature resistance.

The invention will now be explained further with the aid of examples: Example 1 Unsaturated polyester resin is used as a thermosetting compound, that is, as Starting material, related; Calcium carbonate as a filler, spun fiberglass material (glass chopped strand) as reinforcement material, zinc stearate as plasticizer or Release agent, benzoyl peroxide paste with 50 percent dilution - as a catalyst and powdery polyacetal resin are thus at a weight ratio according to Table 1 mixed. The mixture is kneaded as is usual in the production process Polyester is common in a ready-to-use mixture for the production of plastics. the thermosetting resin composition is then available.

To test the electrical properties, the thermosetting Resin mass molded body at a temperature of 120 + 10 0C (393.16 + 10 OK) and one Curing time of 2 to 5 minutes under an injection pressure of 20 to 100 kg / cm2 (1.96 N / mm2- 9.807 N / mm2). The relevant physical properties of the Workpieces manufactured on an experimental basis are summarized in the lower part of Table 1.

Table 1 L 28 oooort rO 5 \ bo 4 XXF n . Polyester (*) 20 oo ~ Ln O 0 rl No noor 4 l 5 oo U r OF h 70 X hn t To (glass chopped strand) 10 10 10 10 o cu c Zinc stearate 1 1 1 1 F9CUrDr r (paste) r 0.4 0.4 0.4 . . . Q No o F or 4 according to ASTM (sec) o 145180 137145 14614 O r after o (V) not lower than 600 0> Specific resistance in normal state 5x1014 4x1014 3x1014 2x1014 (cm) after boiling 8x1 0 3 2x1 0 3x1 o9 2x1 0> lS ç s> H not lower than 200 + 273.16 ~ s N / mm2. 9.80665 x,; 9.2 5.1; L, h # t ~ wx U ha N wd) +) + t 2 Ws hs: 4 + 'gw. + 'hht ho, + 'X 9q z <X X hhhhh HX xo + ' X ç qq @ UA 0X 9 H @ @ : Y h D w ç O +)) 9 E 9 NPN) N) h NO uaSunpulqJaA U3 zTeQsSU STS s (*) "Poriraito ODR-185" manufactured by the Japanese company Dainippon Inki Kagaku Kogyo.

Further tests with the material according to the test series A1, B1, C1 and D1 as the material for the housing of the arc chamber of a circuit breaker at a voltage of 600 volts, a current strength of 12 kA and a power factor of 0.32 have resulted in: The electrical resistance between the quenching plates in the arcing chamber is never lower after the arc has been switched off been like this as 100M. The wall material showed hardly any arcing effects.

A series of comparative tests, tests 1 to 3, carried out with materials available on the market: Experiment 1 ceramic material, layered Melamine resin panels with glass, then panes made of silicone plastic in composite with Glass and polyester resin - with calcium carbonate as a filler and with glass fiber reinforcement - - were used as wall material for the extinguishing chamber of the circuit breaker, who supplied the measured values for Table 1. Under the same conditions a resistance of 0 M 2 was determined between the quenching plates.

It has been shown that such materials give off little gas, support the arc quenching so only insufficiently, and the shutdown properties can deteriorate, especially at low voltage and small currents.

Experiment 2 Another comparative experiment under the conditions of Experiment 1 was carried out with glass fiber material. It has been shown that such Material is seriously impaired in its properties, even perforated and does not retain its original shape.

Experiment 3 Finally, another comparative experiment is a Plastic made from 50 parts of powdered melanin resin with 23 parts of an unsaturated one Polyester compound, 15 parts of glass chopped strand and 0.5 Share benzoyl peroxide as a catalyst as a wall material for the arc chamber according to Example 1 and Experiments 1 and 2 have been used. Even at 555 volts, 10.3 A and a power factor of 0.41 was a resistor between the quenching plates determined from only 0 to 20 M. Such a material therefore also meets the requirements to a material for arc chambers.

Example 2 Material made from thermosetting resin composition according to Table 2 is produced according to Example 1 and tested according to Table 1. The results are shown in Table 2. Subsequent shutdown tests have shown that the materials of the test series A2, B2, C2 and D2 maintain a resistance of 100 M and above between the quenching plates. The walls of the arc chamber have proven to be true to shape, Table 2 Resin mass A2 32 C2 D2 ; 1 polyester (*) 25 25 25 25 I 0 0 = bn cM rrn (uo 5 10 S o 0 Ln MLlr o 30 30 20 10 0 0 a, H o moo cV In O 0 0 Ln UCU-Oic \ Cy omxx c- o (glass chopped strand) h 20 hr 0> k 1 1 1 1 cU Ln 0 0 0 0 0 Benzoyl peroxide ot = vx vx A o 0 ~ n A according to ASTM (sec) 3 150 180 I60 180 150-180 S n ao OOO r ~ according to IEC rn n More specific ° x in normal state 5.0x1014 3.5x1014 3.7x10 3.8x10 o d 0 8 Deformation temperature t not lower than 600 p 273.16 t O ta co N hh Z> ho 9.80665 tsa 10.0 10.7 10.9 * ho D3 ~ vo v H tQ Cb U oX a o N nnnth N a)> 4 bO 4 ç 4o ç ç S H oh ç z X. hh O P4 g tq ~ E bO X t A h bO eo uz X # h ç X # HX .n O ç o 9 @ OOQ QX oh QU h U 9 to. @ o DX hh O o ç X 4 qq HEXOH o> .d UO U: fd zz DU w S n S 9 E 9 SXO. . 9 X o ç O. H @ h r1 g HXN x ONO @ UU n HUH <O. <H A @ < S: vz <. c) cr N an. G ~ uz nm 8 0 9 8 3 4 n 7 n? uaSunPUFql @ t ua; osuaBIs (*) "Poriraito ODR-185" manufactured by the Japanese company Dainippon Inki Kagaku Kogyo.

Claims (4)

Claims 1. Thermosetting resin composition for arc extinguishing Material that does not indicate that a polyacetal compound is added in finely divided form to a thermosetting compound. 2. The thermosetting resin composition according to claim 1, d a d u r c h g e k e It should be noted that the thermosetting compound is an unsaturated polyester compound is. 3. Thermosetting resin composition according to claim 1 or 2, d a d u r c h It is noted that 10 to 300 percent by weight of the polyacetal compound are added to 100 percent by weight of the thermosetting compound. 4. The thermosetting resin composition according to claim 3, d a d u r c h g e k e It is noted that 20 to 250 percent by weight of polyacetal compound to 100 Weight percent of the thermosetting compound are added.