DE60017408T2 - SWITCH - Google Patents

Description

TECHNICAL AREA:

The The present invention relates to a switch using a molded article, made of a flame retardant material with flame retardant Property is built up.

STATE OF THE ART:

When describes conventional flame retardant material for a switch e.g. JP-A-8-171847 a material which is a polyamide, a glass fiber and magnesium hydroxide.

The Japanese Utility Model Laid-Open 2-125943 discloses flame retardant material for a container for one Lighting device comprising a polyester, a glass fiber, calcium carbonate, Aluminum hydroxide, a halogen-based flame retardant and antimony oxide includes.

EP-A1-278 555 describes a polyamide composition, e.g. at least 40% by weight of a polyamide, 5 to 50% by weight of a glass fiber, at most 50% by weight of magnesium hydroxide and 4 to 15% by weight of red phosphorus.

The flame retardant material for a switch described in JP-A-8-171847 contains magnesium hydroxide as Flame retardant, which gives the flame retardant material a high flame retardancy. However, this flame retardant material can not have much higher flame retardancy. To an even higher Flame retardancy, such as in materials containing a halogen-based flame retardant or red phosphorus, to ensure that the flame retardant Material a bigger one Include amount of magnesium hydroxide. A flame-retardant material, the one bigger Contains amount of magnesium hydroxide tends to flawed appearance, such as. a white appearance of the resulting molded Article, or a reduced compressive strength, and is suitable not as a flame retardant material for a switch.

The Technologies disclosed in the Japanese Utility Model 2-125943 and EP-A1-278555 are not for use thought in a switch and belong to another technical Area as the present invention. In addition, these can Technologies problems, such as pollution or corrosion metallic contact parts, as described below, do not solve and can not to be used in a switch.

The flame retardant material for a container for one Lighting device disclosed in Japanese Utility Model Laid Open 2-125943, although has a high flame retardancy, is however not suitable for use in a switch. This is because the material contains a halogen-based flame retardant and some types of halogen-based flame retardants used therein contaminate metallic parts such as contacts or electronic parts or can corrode if they as materials for a switch part can be used. It is believed that the metallic part through a gradual halogen gas formed from the halogen-based flame retardant is contaminated or corroded. In such a device, the halogen gas considered as a polluting gas or as a corrosive gas. additionally can such halogen-based flame retardants may possibly form dioxins and therefore lead to environmental pollution problems. As a flame retardant excipient used antimony is a heavy metal and can pollute the environment.

The Flame retardant material disclosed in EP-A1-278 555 includes at least 40% by weight of a polyamide, 5 to 50% by weight of a glass fiber, at most 50 magnesium hydroxide and 4 to 15 wt% red phosphorus, has one high flame retardancy, is not for suitable for use in a switch. This is because of that this flame-retardant material is magnesium hydroxide and red phosphorus involves as a flame retardant and the inventors have found that this material is satisfactorily flame retardant, however Metallic parts are contaminated or corroded. It is believed that metallic parts of gradually red phosphorus pollutant or corrosive gas Gas contaminated or corroded.

As used herein, the term "contaminant or corrosion" refers to at least one of forming an insulator on the surface of a metallic part, increased volume resistivity of the metallic part, and detecting a highly reactive element (elemental halogen or phosphorus) the surface of the metal.

Of the Expression "polluting or corrosive gas " a gas that is believed to be contaminant or corrosion caused.

One due to contamination or corrosion, degraded, insulating Resistance presents a high barrier to miniaturization and the maximization of the breaking capacity of a switch. Regardless of this a satisfactory flame retardancy of a thin-walled part is necessary to the To reduce the weight of a switch.

Accordingly It is an object of the present invention to address the above problems to solve and thereby provide a switch having a highly flame retardant, molded article includes.

DISCLOSURE OF THE INVENTION:

in the In particular, the present invention provides a switch which includes a molded article made of a flame retardant Material is constructed, wherein the flame-retardant material 35 to 50 % By weight of a resin, 20 to 60% by weight of a reinforcing agent, 5 to 40% by weight an inorganic compound and 0.3 to 1.8% by weight of red phosphorus including the inorganic compound at temperatures, that meet or exceed a predetermined temperature, a dehydration reaction is received.

The The present invention provides a switch wherein the content on red phosphorus 0.5 to 1.8 wt.% Is.

The The present invention provides a switch wherein the contents of inorganic compound and red phosphorus 30 to 40 wt.% or 0.5 to 1.0 wt.% Be.

Of Further, the present invention provides a switch, wherein the resin is a thermoplastic resin.

The The present invention provides a switch wherein the thermoplastic Resin is a polyamide.

The The present invention provides a switch that supports the molded body Includes article at least as part of a housing bottom.

Additionally poses the present invention provides a switch that the molded Article in the vicinity of an arc generated between contacts includes in the other areas a building material, which has a mechanical strength higher than that of the formed one Article.

Of the Expression "% by weight" as used in this Description refers to the ratio of the respective component to the total weight of the composition. In other words, the Total content of the above components in% by weight less than 100% by weight.

DETAILED DESCRIPTION THE INVENTION:

The The present invention will now be illustrated in further detail.

Of the comprises molded articles to be used in the present invention a flame retardant material comprising at least one of the following components includes: 35 to 50% by weight of a thermoplastic resin, 20 up to 60% by weight of a reinforcing agent, 5 to 40% by weight of at least one inorganic compound and 0.3 to 1.8 wt.% Red phosphorus, wherein the inorganic compound is able to withstand temperatures of the molding temperature of the thermoplastic Resin (a predetermined temperature) or exceed this, to undergo a dehydration reaction. Preferably, the content is on red phosphorus 0.5 to 1.8 wt.%. Alternatively, the content is inorganic compound 30 to 40 wt.% And the content of red Phosphorus 0.5 to 1.0% by weight.

Thermoplastic resins:

The thermoplastic resin includes, for example, poly (butylene terephthalate), Poly (ethylene terephthalate), polyamides, aliphatic polyketones, poly (phenylene sulfide) and mixtures of these thermoplastic resins. Of these are typically polyamides due to their satisfactory Heat resistance, Compressive strength, as well as the insulation performance of the resulting Switch after formation of an arc preferred.

Reinforcing agent:

The reinforcing agents is used to improve the compressive strength, and is at least one of the elements selected from the group consisting of glass fibers, inorganic minerals and ceramic fibers. As a reinforcing agent the flame retardant material preferably comprises at least 20% by weight a fiberglass.

Inorganic compounds:

Of the contains molded articles the flame-retardant material, including the inorganic compound. This inorganic compound is capable of a dehydration reaction to address and improve the flame retardancy of the serve shaped article.

This This is probably because if the molded article has elevated temperatures (e.g., temperatures of 340 ° C or more), the inorganic Compound is thermally decomposed in the molded article, the resulting Water vapor slows the heat and one on the formation the water vapor following endothermic reaction which has become vacant Heat absorbed.

The inorganic compound capable of a dehydration reaction to enter and contained in the flame-retardant material in the molded article is, unlike halogen-based or halogen-based flame retardants Flame retardants made of red phosphorus, no contamination or corrosion of metals. Furthermore, the experiments carried out by the inventors indicate suggest that the inorganic compound serves the purpose of Red phosphorus caused contamination or corrosion of metals to prevent. In detail, the inventors have a special ratio of the found inorganic compound to the red phosphorus, wherein the Inorganic compound is able to withstand temperatures of a predetermined Temperature or exceed this, a dehydration reaction enter into. The resulting molded article containing the material containing the specific composition is both in terms of Flame retardancy as well as the durability across from Contamination or corrosion of metals satisfactory.

Of further, the inorganic compound that is capable of to undergo a dehydration reaction and flame retardant Material of the molded article is included, for the prevention of a reduced insulation after formation of an arc between the contacts of electrodes when the switch between the electrodes a closed circuit makes or interrupts contribute.

This is based on the following: When the switch makes or breaks a circuit between the electrodes, an arc is formed between the contacts of the electrodes and the temperature generally increases in the range of about 4,000 to about 6,000 ° C. Because of this, the internal metallic components of the electrodes, the contacts and the switch are heated, a metallic vapor or a droplet of molten metal is formed from the metal and released. At the same time, not only the arc, but also the metallic vapor or droplet of molten metal will decompose the housing of the switch and the internal organic components of the switch, releasing carbon. An insulating property imparting gas is then formed from the inorganic compound contained in the molded article, and this gas imparting an insulating property converts the free carbon or the sublimated metal or the molten metal droplet into an insulator and contributes to the prevention of reduced insulation after formation of an arc. For example, when the inorganic compound undergoing the dehydration reaction is magnesium hydroxide, it is considered that the gas giving an insulating property is H ₂ O. In this regard, when a circuit breaker establishes or breaks a circuit between the electrodes, the free carbon is formed, for example, from the housing or the internal mechanical parts which are molded articles made of flame retardant material, and the sublimed metal is removed from the contacts formed of the internal metallic components from which also the droplet of molten metal is released.

If the free carbon, the metal vapor and the droplet molten metal to be converted into insulators is going through the arc in the vicinity of the contacts a vapor under high pressure formed and stretched, and the gas formed, which is an insulating Lends property, can not penetrate into the environment of the contacts. Accordingly, one of the free carbon, the metal vapor and the droplet derived from molten metal insulating layer in the Environment of the contacts is not formed, and therefore does not inhibit the excitement of the circuit.

The Dehydration reaction of the inorganic compound used in the It is possible to enter into a dehydration reaction at a temperature of 250 ° C or more initiated to initiate a dehydration reaction of the inorganic Connection during kneading, i. when using the thermoplastic resin and others Components are kneaded to work around.

Such inorganic compounds capable of undergoing dehydration reaction at temperatures of 250 ° C or more include, for example, calcium aluminate (Ca ₃ Al ₂ (OH) ₁₂ ), zinc borate (2ZnO, 3B ₂ O ₃ , 3.5H ₂ O ), Calcium hydroxide (Ca (OH) ₂ ) and magnesium hydroxide (Mg (OH) ₂ ).

If the thermoplastic resin is a polyamide, the temperature rises a mixture of the thermoplastic resin, the reinforcing agent, the inorganic compound and red phosphorus during the Kneading or molding in the range of 340 ° C, due to a fixed Temperature of the kneading process and that caused by the shearing Heat. In this case, is to while kneading or molding a dehydration reaction of the inorganic acid, the is able to undergo a dehydration reaction to get around the initiation temperature of the dehydration reaction of the inorganic Compound that is capable of a dehydration reaction to enter, preferably 340 ° C. or more. On the other hand, the decomposition of a polymer generally becomes at temperatures in the range of 400 to 550 ° C, temperatures just below the combustion temperature are initiated. Accordingly, when the initiation temperature of the dehydration reaction is disproportionately high in other words, if the initiation temperature of the dehydration the inorganic compound capable of dehydration reaction higher as the initiation temperature of the decomposition of the polymer sufficient flame retardant effect is not achieved and is also not wanted.

inorganic Compounds that are capable of a dehydration reaction to enter and which meet these requirements, close for example, calcium hydroxide and magnesium hydroxide.

Under magnesium hydroxide is typically preferred because of its efficiency the flame retardancy with increasing heat absorption per unit mass increases.

Under the inorganic compounds that are capable of a dehydration reaction are calcium hydroxide, calcium aluminate and magnesium hydroxide not toxic and preferable.

If the content of inorganic compound which is capable of Temperatures of the mold temperature of the thermoplastic resin match or exceed this to undergo a dehydration reaction is 40% by weight or more the resulting molded article thereto, decreased tensile strength show, as well as to a white appearance on its surface, the This contributes to a faulty appearance of the switch.

Red phosphorus:

When red phosphorus become red phosphor particles with an average particle size in the range of 25 to 35 μm, and which are coated with phenol used.

A content of red phosphorus exceeding 1.0% by weight tends to deteriorate the electroconductive property. This tendency is noticeable when the content exceeds 1.8% by weight. This tendency is believed to be due to the increased content of flame retardant red phosphorus. This is probably due to the fact that phosphine (PH ₃ ) and phosphoric acid (H ₂ PO ₃ ), which are phosphorus compounds capable of contaminating or corroding metals, are formed from the flame-retardant red phosphorus and that these substances are attached to the Make contacts of the switch insulating compounds, and thereby contaminate the metal of the contacts or corrode.

If in contrast, the content of red phosphorus is less than 0.5 % By weight and especially less than 0.3% by weight, the flame retardant tends Effect to become inadequate.

Of the Content in% by weight of red phosphorus is given as red phosphorus.

Around to avoid a degradation of the power line characteristic, i. to avoid contamination or corrosion of metal the red phosphor preferably at least one of surface coating of red phosphorus and adsorbent for phosphorus compounds.

In addition will preferably in combination with the red phosphorus, an impurity or corrosion inhibitor used. The impurity or corrosion inhibitor is a substance that causes red phosphorus pollution or corrosion of metals. For example, a alkaline substance preferred when the resin is a polyamide.

includes a molded article not the inorganic compound used in able to withstand temperatures of a predetermined temperature match or exceed this to undergo a dehydration reaction, but the red phosphorus, the reinforcing agent and the thermoplastic resin, it tends to form after the formation of a Arc, i. after being exposed to the arc, have a reduced electrical resistance. This is probably because of a carbonized layer on the inner surface of the switch housing, or to a surface the internal components of the switch is bound.

Of the Red phosphorus is not a halogen-based flame retardant and does not form any Dioxins.

As described above, a molded article for a Switch, both in terms of its flame retardancy as well as its permanence against the contamination of the metal or the corrosion of the metal is satisfactory, by the combined use of red phosphorus and an inorganic compound, in addition to the resin and the reinforcing agents and by the specific selection of the ratio of red phosphorus and the inorganic compound, wherein the inorganic Compound is able to withstand temperatures specific to one Temperature or exceed this, a dehydration reaction enter into.

in the Individual one assumes that within the above mentioned quantity ratio the amount of red phosphorus extremely is low, thereby forming a carbonized layer and that lends an insulating property Gas that's made of the inorganic compound that is able to to undergo a dehydration reaction that is carbonated Layer converted into an insulator. A decrease in the electrical Resistance is thereby prevented, thereby reducing the Isolation after the formation of an arc to inhibit. In addition, both the red phosphorus flame retardant as well as the inorganic compound, which is capable of undergoing a dehydration reaction, the flame retardancy increase.

The Flame retardant material includes extremely small traces (0.3 to 1.8 wt.%) of red phosphorus, as well as a small amount (5 to 40% by weight) of an inorganic compound which is able to undergo a dehydration reaction, and can achieve a very high degree of flame retardancy, which only by large amounts of the inorganic compound can be achieved alone can. In this case, all that is needed in terms of flame retardancy and durability against contamination of the metal or corrosion of the metal a relatively small amount (5% by weight or more) of the inorganic compound, the resulting molded article has no reduced compressive strength up and can be a thin one Wall to be shaped. The flame retardancy generally decreases 5 wt.% Of the inorganic compound with increasing amount of inorganic Connection.

In addition, can the combined use of red phosphorus and inorganic Compound that is capable of withstanding temperatures that are predetermined Temperature or exceed this, a dehydration reaction reduce the amount of red phosphorus needed the same flame retardancy to maintain, and can the resistance to contamination of the metal or corrosion, compared to the use of the Flame retardant red phosphorus as flame retardant alone, improve.

When the red phosphorus in conjunction with the inorganic compound capable of, at temperature, which exceeds or exceeds a predetermined temperature, a dehydration is used, and the inorganic compound capable of undergoing a dehydration reaction is an alkaline substance such as hydroxide, it is considered that the inorganic compound has the role of impurity with respect to the red phosphorus or corrosion inhibitors, so as to effectively inhibit the contamination or corrosion of the metal.

BRIEF DESCRIPTION OF THE DRAWINGS:

1 Fig. 12 is a cross-sectional view of the side of a switch according to Example 1 of the present invention;

2 is a cross-section along the plane of the switch 1 ;

3 Fig. 12 is a perspective view, partially in section, of the housing base of a switch according to Example 2 of the present invention.

EXAMPLES

The The present invention will be described with reference to some examples below illustrated in more detail.

EXAMPLE 1

Test pieces were of flame retardant materials, as shown in Table 1 below, molded and exposed to the following combustion tests.

1 is a cross-section through the side of a switch corresponding to Example 1 of the present invention, and 2 is a cross-section along the plane of the switch 1 ,

Combustion test 1 (glow-wire test acc GWFI (glow-wire flammability index) at 960 ° C]

This Combustion test is in the Japanese Industrial Standards (JIS) C0074, wherein a filament heated at 960 ° C for a period of 30 seconds against a test piece depressed and after removal of the wire, the condition of the test piece is evaluated has been.

Each of the test pieces was 75 mm ² with an optionally set thickness.

The Criteria of this test are that a flame or a glow within of 30 seconds disappeared and that one placed under the test piece Tissue paper not inflamed. If the test piece these criteria at constant thickness three or more times in a row fulfilled, it had passed. In this review, test pieces were after the thickness with which the test piece had passed, classified.

Combustion test 2 (Hot Wire Ignition Test, HWI):

This Combustion test is described in IEC 974-1, where a mandatory Nichrome wire around a test piece was wound, whereupon fed a prescribed power was, so the test piece to heat until it ignited. After ignition of the test piece the power was turned off and the time elapsed until ignition was arrested. Of each material tested, 5 became test pieces tested. In this review, a test piece had passed when the time the one to the ignition passed, 30 seconds or more.

Test pieces are 150 mm long and 13 mm wide, with an optionally fixed thickness. The nichrome wire was five times wound, with intervals of 6 mm.

Test of resistance against contamination (corrosion) of metal:

One according to The molded article obtained in Example 1 was subjected to the following test Subject to contamination or corrosion of metal.

The molded article was the pedestal ( 1 ) one in. the 1 and 2 shown housing.

When article to be contaminated or corroded (hereinafter "contaminated article Called article ") two articles, i. a copper plate (C11001 / 4H) and a Silverplated copper plate obtained from this copper plate, respectively 28mm × 14 mm × 1 mm, used.

The article to be contaminated (including one layer of the copper plate and two layers of the silver plated plate) was subjected to ultrasonic cleaning in acetone and applied to the in 2 shown underside of the socket ( 5 ) placed.

Next, the socket ( 1 ) to trap gas contaminating metal or gas corroding the metal formed from the pedestal and to prevent gas from entering the packaging in a thermostat (climatic chamber) described below.

Then the packaged sample, the pedestal ( 1 ), for 3,000 hours in the thermostat (120 ° C) left.

After leaving in the thermostat, a non-contact surface between the article to be corroded and the molded article (base ( 1 ) was analyzed with the SEM (Scanning Electron Microscope) and the XMA (Energy Dispersive X-ray Analyzer) to evaluate the resistance to metal contamination or metal corrosion.

In this method, possible areas to be measured of the article to be contaminated are both a contact surface and a non-contact surface of the article to be contaminated with the molded article (pedestal). 1 )), however, the non-contact surface in this test was measured and evaluated as a result of the following preliminary examination.

After leaving in the thermostat, a contact surface and a non-contact surface between the article to be contaminated and the molded article (base ( 1 )) with the SEM (Scanning Electron Microscope) and the XMA (Energy Dispersive X-ray Analyzer). As a result, a larger amount of red phosphorus was present in the non-contact surface between the article to be contaminated and the molded article (pedestal). 1 )). It was believed that this contamination or corrosion is not corrosion occurring on a contact surface with the molded article, but contamination or corrosion caused by gas exiting the formed article in a jet. Accordingly, the resistance to contamination of metal as described above was measured on a noncontact surface of the article to be contaminated with the molded article (pedestal). 1 )) rated.

Measurement of volume resistance:

The volume resistivity was measured in the following manner: After standing in the thermostat, two layers of the silvered plate were removed from the packaged sample (base ( 1 1) was fed between the two plates while applying a set contact pressure to the overlapping region, and the volume resistivity was determined from the voltage drop in the overlapping region of the test pieces.

The edge of the silver plated copper plate test pieces to be overlapped to measure the volume resistivity was 14 × 15 mm, and the contact pressure was about 98 KPa (about 1.0 kg / cm ² ).

The surface of the article to be contaminated was analyzed by SEM and XMA (voltage applied to the electron gun: 15 kV). The area to be analyzed by XMA was about 10 × 7 mm ² .

The surface of the article to be contaminated was based on an SEM image and XMA signals (especially one calculated from the P and Ag signals Mass ratio) analyzed.

Test results:

The Test results are described below. Table 1 is one Table showing the test results of samples 1 to 7.

rehearse 1 to 3 each comprised 40 to 50 wt% of nylon 6, 45 to 60 % By weight of a glass fiber or a mixture of glass fiber and wollastonite as a reinforcing agent, 5 wt.% Or more of magnesium hydroxide and 1.2 to 5.4 wt.% Of red phosphorus as a flame retardant.

rehearse 4 to 6 each comprised 40 to 50 wt% of nylon 6, 20 wt% of one Glass fiber as reinforcing agent, 30 to 40% by weight of magnesium hydroxide and a very small amount, 0.3 to 1 wt.%, Of red phosphorus as a flame retardant.

sample 7 comprised 50% by weight of nylon 6, 20% by weight of a glass fiber as reinforcing agent and 30 wt.% of magnesium hydroxide as the sole flame retardant.

sample 1 (containing 5.4% by weight of red phosphorus and 5% by weight of magnesium hydroxide) pointed out in the glow wire test GWFI at 960 ° C was a satisfactory flame retardancy of 1.5 mm, but was in terms of the resistance insufficient against contamination or corrosion of metal.

To standing at 120 ° C for about For 1,000 hours, a phosphorus compound in areas of the surface of this Sample was found and phosphorus was on a surface of the detected by SEM and XMA silver plated copper plate.

In addition, the volume resistivity in a region where two layers of the silvered plates overlapped was remarkably increased, indicating that phosphorus was detected. If a molded article composed of a flame-retardant material is used as a housing for a switch, the phosphorus compound may be applied to surfaces of immobile contact (FIG. 2 ) as well as the mobile contact ( 3 ) and thereby cause a defective passage of electricity.

There in the silvered plate phosphorus was detected, the Copper plate subjected to any analysis by SEM or XMA, in the a higher one Amount of phosphorus was detected.

sample 2 (containing 1.8% by weight of red phosphorus and 5% by weight of magnesium hydroxide) and Sample 3 (containing 1.2% by weight of red phosphorus and 5% by weight). magnesium hydroxide) in the glow wire test according to GWFI at 960 ° C a satisfactory Flame retardancy 2.0 mm and were also tested for contamination or corrosion Satisfactory on the silvered plate.

In these samples were tested for contamination or corrosion the copper plate detected a small amount of phosphorus (P / Cu = 0.03), but the amount was very small and one for use limited in a switch insignificant level.

sample 4 (containing 1.0% by weight of red phosphorus and 40% by weight of magnesium hydroxide) and Sample 5 (containing 0.5% by weight of red phosphorus and 30% by weight). magnesium hydroxide) in the GWFI glow wire test at 960 ° C had a satisfactory flame retardancy of 1.5 mm, and in the HWI test of 1.5 mm, on. In the test for contamination or corrosion on the silver plated plate of Samples 2 and 3 no phosphorus was detected and in each of these samples was the Content of red phosphorus higher and the content of magnesium hydroxide lower than in the samples 4 and 5, wherein the magnesium hydroxide as impurity or corrosion inhibitor served. Accordingly, it was assumed that in the tests on Contamination or corrosion on the silvered plates of samples 4 and 5, which had fewer factors to deliver phosphorus, no Phosphorus was detected.

sample 5 was reduced by the addition of a small amount (0.5 wt.%) Of red Phosphorus to sample 7 was in terms of durability satisfactory against the contamination of metal or the corrosion of metal and had a significantly improved flame retardancy compared to Sample 7. Around with the sole use of magnesium hydroxide as a flame retardant to achieve an equivalent flame retardancy, the Material an even bigger Amounts of magnesium hydroxide include (e.g., over 50 wt% of magnesium hydroxide). A content of magnesium hydroxide exceeding 40% by weight may become white Appearance of surfaces, and otherwise cause defective appearance of the molded article and can degrade the compressive strength.

sample 6 (containing 0.3% by weight of red phosphorus and 30% by weight of magnesium hydroxide) exhibited a satisfactory flame retardancy, as they were in the glow wire test GWFI at 960 ° C failed with 1.5 mm and consisted of 2.0 mm, and in the inflammatory test with the hot wire with 1.5 mm did not exist and with 2.0 mm was. This sample was also re their consistency against the contamination of metal or the corrosion of metal satisfactory, and it was neither in the silvered plate still detected in the copper plate phosphorus.

Sample 7 was a comparative example which did not contain red phosphorus, was in its inventory satisfactory against metal contamination or corrosion of metal, but inferior to Samples 1 to 6 in their flame retardancy.

These Results show that from the flame retardant materials of samples 2 to 6 obtained molded articles both in their flame retardancy as also their consistency against the contamination of metal or the corrosion of metal are satisfactory, and that from the flame-retardant materials molded articles obtained from Samples 4 and 5 both in terms of their Flame retardancy as well as regarding their consistency against the contamination of metal or the corrosion of metal are even more satisfactory.

If the content of red phosphorus is 1.8% by weight or less, so the durability against the contamination or corrosion of the resulting flame retardant Good material, as far as it contains 5% or more of magnesium hydroxide, what suggesting that magnesium hydroxide in this quantity is satisfactory serves as an impurity inhibitor or as a corrosion inhibitor. Samples 4 to 7 comprise a large amount, 30 to 40% by weight, of magnesium hydroxide, around the flame retardancy to improve.

EXAMPLE 2

3 is a perspective view, partially in cross section, of a housing base of a switch according to Example 2 of the present invention. In 3 the housing of a disconnector includes the base ( 11 ), and the underside of the socket ( 13 ) represents an outer surface of the base ( 11 ) and is disposed in a position far away from an arc formed between contacts not shown. The bottom of the socket ( 13 ) is composed of a structural material having satisfactory mechanical strength, such as a thermosetting resin or a thermoplastic resin alone or a composite including these resins, and a reinforcing agent as described in Example. The arched part of the base ( 15 ) is so at a position of the base ( 11 ) is exposed to the arc formed between the contacts not shown, and is composed of the composite described in the embodiment (1). The arched part of the base ( 15 ) is hatched for reasons of clarity.

The base ( 11 ) can be obtained by using a composite material for the underside of the base ( 13 ) or a composite material for the curved part of the base ( 15 ) are respectively set in predetermined positions of a model shape, not shown, and the two composite materials are heated and pressed.

As thus described, the domed portion of the socket (FIG. 15 ) of the socket ( 11 ) a molded article which is satisfactory in terms of its flame retardancy and resistance to metal contamination or corrosion, and the underside of the socket ( 13 ), which is far from the source of an arc, consists of a structural material with satisfactory mechanical strength. This configuration can be used to prevent the insulation resistance of a surface of the base ( 11 ) decreases after the formation of an arc, without causing a deterioration of the creep resistance.

In Example 2, an embodiment is explained in which the composition of Example 1 only in the vicinity of contacts of the curved portion of the base ( 15 ) alone, which only a part of an inner surface of the base ( 11 ), since this area is exposed to the arc and its insulation resistance is significantly reduced. It is also effective, the composition of Example 1 on the entire inner surface of the base ( 11 ).

INDUSTRIAL APPLICABILITY:

Of the invention Switch consists of a flame retardant material, comprising 35 up to 50% by weight of a resin, 20 to 60% by weight of a reinforcing agent, 5 to 40% by weight of an inorganic compound and 0.3 to 1.8% by weight on red phosphorus, and the inorganic compound is able to at temperatures that correspond to the predetermined temperature or these exceed, to undergo a dehydration reaction. This switch is with respect to his Flame retardancy and its consistency against the contamination of metal or the corrosion of metal satisfactory.

If the content of red phosphorus is 0.5 to 1.8% by weight, so the resulting switch with respect its flame retardancy even more satisfactory.

If the content of inorganic compound is 30 to 40% by weight, and the Content of red phosphorus is 0.5 to 1.0% by weight, so is the resulting Switch regarding its consistency against the contamination of metal or the corrosion of metal even more satisfactory.

is the resin is a thermoplastic resin, so the material without difficulty to a thin-walled Articles are shaped.

If the thermoplastic resin is a polyamide, so is the resulting Switch satisfactory regarding its insulating property after the formation of an arc.

If the switch comprises a molded article as the base of its housing, so the switch is satisfactory, for example with respect to his Flame retardancy, its insulating property after the formation of an arc as well as its mechanical strength and can be miniaturized.

If the switch the molded article in the vicinity of an arc includes, which is formed between contacts, and in other areas includes a structural material, and the structural material a higher has mechanical strength than that of the molded article, so has the resulting switch satisfactory creep resistance.

Claims (9)

Switch that includes a molded article, which is constructed from a flame-retardant material based on of the total weight of the flame retardant material comprises: (I) 35-50 % By weight of a resin, (ii) 20-60% by weight of a reinforcing agent; (Iii) 5-40% by weight an inorganic compound capable of, at temperatures, that meet or exceed a predetermined temperature, to undergo a dehydration reaction, and (iv) 0.3-1.8% by weight red phosphorus. Switch according to Claim 1, wherein the content of red phosphorus is 0.5-1.8% by weight. is. Switch according to Claim 1, wherein the contents of inorganic compound and red Phosphorus 30-40 Wt.% Or 0.5-1.0 % By weight. Switch according to Claim 1, wherein the resin is a thermoplastic resin. Switch according to Claim 4, wherein the thermoplastic resin is a polyamide. Switch according to Claim 1, the molded article at least as part of the housing bottom includes. Switch according to Claim 6, which the molded article in the environment of between Contacts generated arc, and in the other areas a building material having a mechanical strength, the higher is the one of the molded article. Switch according to at least one of the preceding claims, wherein the red phosphorus coated with phenol. Switch according to at least one of the preceding claims, wherein the flame retardant Material further comprises an absorbent for phosphorus compounds.