JP2008130375A - Arc-extinguishing resin processed product, and circuit breaker using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an arc-extinguishing resin processed product capable of generating a pyrolysis gas hardly contributing to internal pressure rise and capable of efficiently extinguishing an arc generated in shutting off a circuit, having heat resistance resistant to temperature rise occurring then, and pressure tightness resistant to internal pressure rise, and excelling in flame resistance; and a circuit breaker using it. <P>SOLUTION: In this circuit breaker provided with a fixed contact having a fixed contact point, a moving contact having a moving contact point contacting the fixed contact, and carrying out switching operation with respect to the fixed contact, and an arc-extinguishing device extinguishing an arc generated when the fixed contact and the moving contact carry out the switching operation, this arc-extinguishing resin processed product is composed, for the arc-extinguishing device, by molding a resin composition containing a polyolefin resin containing 0.2-0.7 mol of a hydrocarbon group in 1 mol of a methylene group with a part of hydrogen atoms of a methylene chain substituted by the hydrocarbon group, and a reactive organic phosphorous-based flame retarder having a terminal unsaturated bond, and thereafter applying radiation crosslinking thereto. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an arc-extinguishing resin processed product having flame retardancy and a circuit breaker using the same, which are used to extinguish an arc generated from a contact at the time of current interruption such as a circuit breaker.

  In a circuit breaker or the like, when the contact of the movable contact and the contact of the fixed contact are opened when an excess current or a rated current is applied, an arc is generated between the contacts. In order to extinguish this arc, an arc extinguishing device having an arc extinguishing chamber made of an arc extinguishing member is usually arranged around the arc generating portion. Then, the arc extinguishing member is pyrolyzed by the arc, and the arc is extinguished by the pyrolysis gas generated from the arc extinguishing member.

  These arc extinguishing members include thermosetting resins such as unsaturated polyester resins (see Patent Document 1) and melamine resins (see Patent Document 2), polyolefin resins, polyamide resins, and polyacetal resins (see Patent Document 3). A thermoplastic resin or the like is mainly used as the matrix resin.

  However, since the thermosetting resin tends to generate burrs during molding, there is a problem that molding processability is inferior to that of a thermoplastic resin. Furthermore, when arc extinguishing, pyrolysis gas is generated from the arc extinguishing member, so that the internal pressure in the arc extinguishing device increases. However, it is relatively hard, but it is easily damaged and the thermosetting resin having poor pressure strength is extinguished. It was difficult to reduce the size of the arc device.

  In addition, the thermoplastic resin hardly generates burrs during molding, but has poor strength, pressure resistance, and heat resistance, and the arc extinguishing member tends to be deformed or deteriorated with time. On the other hand, a thermoplastic resin having a large aromatic ring content, such as an aromatic polyamide resin, is relatively excellent in strength, pressure resistance, and heat resistance, but easily releases free carbon during combustion. For this reason, there exists a possibility that an arc-extinguishing apparatus may be corroded by carbon, and there existed a problem that the insulation of an arc-extinguishing apparatus was impaired.

  Moreover, in order to improve the strength, pressure resistance, heat resistance, etc. of thermoplastic resins and thermosetting resins, attempts have been made to add inorganic fillers such as reinforcing fibers (see Patent Documents 1 to 4), but inorganic As the filler content increased, the amount of pyrolysis gas tended to decrease, and there was a problem that arc extinguishing performance decreased.

  On the other hand, Patent Document 5 below discloses a circuit breaker using a resin processed product obtained by subjecting a thermoplastic resin such as polyester or polyamide to electron beam treatment.

In recent years, the flame retardancy level required for resin materials used for circuit breakers has been increasing. As a countermeasure, it is conceivable to use a flame retardant resin as a matrix resin for the arc extinguishing material. And, it is known that halogen compounds such as bromine are effective for making the resin flame-retardant, and resins to which a halogen compound is added are widely used as flame-retardant resins. However, flame retardant resins containing a large amount of halogen compounds may generate dioxins depending on the combustion conditions. From the standpoint of environmental impact, the use of non-halogen flame retardant resins that do not contain halogen compounds has recently been used. It is desired.
Japanese Patent No. 3098042 JP-A-2-256110 Japanese Patent Laid-Open No. 7-302535 JP-A-8-171847 International Publication No. 2003-044818 Pamphlet

  Although the improvement in strength, heat resistance, pressure resistance and the like was recognized by applying a crosslinking treatment to the thermoplastic resin, no improvement was observed in the arc extinguishing property. In addition, the increase in internal pressure in the arc extinguishing device due to pyrolysis gas generated during arc extinguishing could hardly be suppressed, and the arc extinguishing device was easily damaged by the increase in internal pressure during arc extinguishing. Furthermore, it has a problem about flame retardancy.

  Therefore, an object of the present invention is to generate a pyrolysis gas that can suppress the arc generated at the time of circuit interruption with little increase in internal pressure, and further withstand heat resistance and internal pressure increase that can withstand the temperature increase that occurs at that time. An object of the present invention is to provide an arc-extinguishing resin processed article having excellent pressure resistance and excellent flame retardancy, and a circuit breaker using the same.

  In order to achieve the above object, in the arc extinguishing resin processed product of the present invention, a part of the hydrogen atoms of the methylene chain is substituted with a hydroxyl group, and the hydroxyl group is 0.2 to 0.7 mol per 1 mol of the methylene group. The resin composition containing the contained polyolefin resin (A) and the reactive organophosphorus flame retardant (B) having a terminal unsaturated bond is subjected to radiation crosslinking after molding.

  According to the arc extinguishing resin processed product of the present invention, the terminal unsaturated bond of the reactive organophosphorus flame retardant (B) reacts with the polyolefin resin (A) by radiation, and is crosslinked in a three-dimensional network. Therefore, the flame retardant component is stably incorporated in the resin. For this reason, there is little bleed-out of a flame retardant, it can exhibit flame retardance over a long period of time, and since the polyolefin resin (A) is crosslinked in a three-dimensional network, the strength, heat resistance, and pressure resistance are improved. .

Also, the polyolefin resin (A), because it is easy OH group is dissociated with the thermal decomposition in the side chain, can generate hydrogen gas, H 2 _O, a high pyrolysis gas of the content of O ₂ and O. For this reason, the arc can be extinguished quickly, and the content of components such as tar that do not contribute significantly to the arc extinction is small, and the internal pressure in the arc extinguishing device can be suppressed. Further, since carbon is hardly attached to the arc extinguishing device during arc extinguishing, the insulating property of the arc extinguishing device is not impaired.

  In the arc extinguishing resin processed product of the present invention, the resin composition contains a polyacetal-based resin (C) in which the content of repeating units derived from oxymethylene is 75 to 100 mol%, and the polyolefin resin ( A) It is preferable to contain 5-90 mass parts with respect to 100 mass parts. Polyacetal-based resins can generate pyrolysis gas with high arc extinguishing action, but are inferior in molding processability due to difficulty in molding by melt-kneading, and the generation amount of pyrolysis gas is high. Since pyrolysis gas has a relatively high contribution to the increase in internal pressure, the internal pressure in the arc extinguishing device tends to increase. According to this aspect, by using the polyolefin resin (A) and the polyacetal resin (C) in combination, it is possible to improve arc extinguishing properties without impairing the moldability of the resin composition.

  Further, in the arc extinguishing resin processed product of the present invention, the resin composition is selected from glass fiber, barium titanate whisker, silica gel fine particles, boehmite, talc, magnesium carbonate and metal hydroxide. It is preferable to contain 1-70 mass% of 1 or more types of inorganic fillers (D). According to this aspect, the strength and pressure resistance of the resin processed product can be improved.

  In the arc extinguishing resin processed product of the present invention, the decomposition latent heat of the polyolefin resin (A) is preferably 30 cal / g or more.

  In the arc extinguishing resin processed product of the present invention, the polyolefin resin (A) is preferably an ethylene-vinyl alcohol copolymer.

  According to each said aspect, since the pyrolysis gas excellent in arc extinguishing property can be generated, an arc can be extinguished rapidly and an arc voltage is hard to be impaired.

  Further, in the arc extinguishing resin processed product of the present invention, the responsive organophosphorus flame retardant (B) is an organophosphorus compound represented by the following formula (I) and / or the following formula (II): It is preferable to contain 0.5-20 mass% in a thing.

(In formula (I), R ^{1 to} R ⁴ each represents CH ₂ ═CY ¹ —Y ² — or a monofunctional aromatic hydrocarbon group that may contain a hetero atom, and R ⁵ represents a hetero atom. X ^{1 to} X ⁴ each represents a group selected from —O—, —NH—, and — (CH ₂ ═CY ¹ —Y ² ) N—. And at least one of X ^{1 to} X ⁴ contains —NH— or — (CH ₂ ═CY ¹ —Y ² ) N—, wherein at least one of R ^{1 to} R ⁴ and X ^{1 to} X ⁴ is CH. ₂ = CY ¹ -Y ² -is included, Y ¹ represents hydrogen or a methyl group, Y ² represents an alkylene group having 1 to 5 carbon atoms, or —COO—Y ³ —, where Y ³ represents carbon. Represents an alkylene group of formula 1-5.)

(In the formula (II), at least one P—C bond is contained in one molecule, and Ar ₁ and Ar ₂ are each a bifunctional aromatic hydrocarbon group containing no mobile hydrogen having 20 or less carbon atoms. N is an integer of 0 to 2. R ^{6 to} R ¹⁰ are —NHCH ₂ CH═CH ₂ , —N (CH ₂ CH═CH ₂ ) ₂ , —OCH ₂ CH═CH ₂ , — _{CH 2 CH = CH 2, -CH} 2 CH 2 OCH = CH 2, - (C 6 H 4) -CH = CH 2, -O (C 6 H 4) -CH = CH 2, -CH 2 (C 6 _{H 4) -CH = CH 2,} -NH (C 6 H 4) -CH = CH 2, -N (CH 2 CH = CH 2) - (C 6 H 4) -CH = CH 2, -O-R A group selected from —OOC—C (R ′) ═CH ₂ , —NH—R—NHCO—C (R ′) ═CH ₂ and an aryl group having 12 or less carbon atoms; Here, R represents an alkylene group having 2 to 5 carbon atoms, R ′ represents hydrogen or a methyl group, and at least one of R ^{6 to} R ¹⁰ is —CH═CH ₂ group or —C (CH ₃ ) ═. Including CH ₂ groups)
The responsive organophosphorous flame retardant (B) is stable in terms of energy, hardly vaporizes during kneading and molding into a resin, and further difficult to be decomposed by heat or shearing, thus impairing molding processability. There is nothing.

  In the arc extinguishing resin processed product of the present invention, the polyacetal resin (C) is preferably an oxymethylene-oxyethylene copolymer or an oxymethylene polymer. According to this aspect, since the pyrolysis gas excellent in arc extinguishing properties can be generated, the arc can be extinguished quickly and the arc voltage is not easily lost.

  In the arc extinguishing resin processed product of the present invention, it is preferable that the polyacetal resin (C) is dispersed in the polyolefin resin (A) to form a microphase separation structure. According to this aspect, when the arc extinguishing resin processed product is pyrolyzed, the polyacetal-based resin (C) is easily pyrolyzed, so that it is possible to release a pyrolysis gas having high arc extinguishing properties, and to extinguish the arc quickly. it can.

  Meanwhile, the circuit breaker of the present invention includes a fixed contact having a fixed contact, a movable contact having a movable contact that contacts the fixed contact, and opening and closing the fixed contact, and the fixed contact. In a circuit breaker comprising an arc extinguishing device that extinguishes an arc generated when a child and the movable contact are opened and closed, the arc extinguishing device is made of the arc extinguishing resin processed product. And According to the circuit breaker of the present invention, it is possible to effectively extinguish an arc generated from the contact when the current is interrupted, and to suppress an increase in internal pressure in the arc extinguishing device. For this reason, it can be set as a circuit breaker excellent in interruption | blocking performance, such as overload interruption | blocking and short circuit interruption | blocking, by size reduction.

  The arc extinguishing resin processed product of the present invention is excellent in strength, pressure resistance, heat resistance, flame retardancy, and molding processability, and generates a pyrolytic gas having a high arc extinguishing action. The arc generated from the arc can be extinguished efficiently, and an increase in internal pressure in the arc extinguishing device can be suppressed. For this reason, the circuit breaker of the present invention using this arc-extinguishing resin processed product can be miniaturized and can have excellent interruption performance such as overload interruption and short-circuit interruption.

In the arc extinguishing resin processed product of the present invention, part of the hydrogen atoms of the methylene chain is substituted with a hydroxyl group, and the hydroxyl group (—OH) is 0.2 to 0 with respect to 1 mol of the methylene group (—CH ₂ —). The resin composition containing 0.7 mol of the polyolefin resin (A) and the reactive organophosphorus flame retardant (B) having a terminal unsaturated bond was obtained by subjecting the resin composition to radiation crosslinking after molding.

  The polyolefin resin (A) contains 0.2 to 0.7 mol of hydroxyl group per mol of methylene group, and 0.2 to 0.65 mol of hydroxyl group per mol of methylene group. It is preferable to contain. When the hydroxyl group is less than 0.2 in the above ratio, it is difficult to generate a pyrolysis gas excellent in arc extinguishing property during pyrolysis, and not only the arc cannot be extinguished quickly but also the internal pressure in the arc extinguishing device during arc extinguishing Tend to be larger. On the other hand, when the hydroxyl group exceeds 0.7 in the above ratio, the heat resistance is lowered, and further, the thermal decomposition temperature is lowered and the molding process by melt kneading tends to be difficult.

  The polyolefin resin (A) preferably has a decomposition latent heat of 30 cal / g or more, and more preferably 40 cal / g or more. Here, in order to improve the decomposition latent heat of the polyolefin resin (A), the content of the hydroxyl group may be increased. For example, in one mole of methylene group in which a part of the hydrogen atoms of the methylene chain is substituted with a hydroxyl group. On the other hand, the polyolefin resin containing 0.2 to 0.7 mol of hydroxyl group has a latent heat of decomposition of 30 to 50 cal / g. The latent heat of decomposition of the resin can be measured by thermally decomposing the resin to be measured in an inert atmosphere.

  As such a polyolefin resin, an ethylene-vinyl alcohol copolymer is preferable, and an ethylene-vinyl alcohol copolymer is particularly preferable because of excellent arc extinguishing properties. However, polyethylene has poor arc-extinguishing properties, and polyvinyl alcohol limits the molding method.

  Moreover, the said reactive organophosphorus flame retardant (B) is an organophosphorus compound which has a terminal unsaturated bond, and the organophosphorus compound shown by following formula (I) and following formula (II) is preferable.

(In formula (I), R ^{1 to} R ⁴ each represents CH ₂ ═CY ¹ —Y ² — or a monofunctional aromatic hydrocarbon group that may contain a hetero atom, and R ⁵ represents a hetero atom. X ^{1 to} X ⁴ each represents a group selected from —O—, —NH—, and — (CH ₂ ═CY ¹ —Y ² ) N—. And at least one of X ^{1 to} X ⁴ contains —NH— or — (CH ₂ ═CY ¹ —Y ² ) N—, wherein at least one of R ^{1 to} R ⁴ and X ^{1 to} X ⁴ is CH. ₂ = CY ¹ -Y ² -is included, Y ¹ represents hydrogen or a methyl group, Y ² represents an alkylene group having 1 to 5 carbon atoms, or —COO—Y ³ —, where Y ³ represents carbon. Represents an alkylene group of formula 1-5.)

(In the formula (II), a bifunctional aromatic hydrocarbon system containing at least one P—C bond in one molecule, and Ar ₁ and Ar ₂ each containing no mobile hydrogen having 20 or less carbon atoms Represents a group, and n is an integer of 0 to 2. R ^{6 to} R ¹⁰ are —NHCH ₂ CH═CH ₂ , —N (CH ₂ CH═CH ₂ ) ₂ , —OCH ₂ CH═CH ₂ , respectively. _{-CH 2 CH = CH 2, -CH} 2 CH 2 OCH = CH 2, - (C 6 H 4) -CH = CH 2, -O (C 6 H 4) -CH = CH 2, -CH 2 (C _{6 H 4) -CH = CH 2} , -NH (C 6 H 4) -CH = CH 2, -N (CH 2 CH = CH 2) - (C 6 H 4) -CH = CH 2, -O- R—OOC—C (R ′) ═CH ₂ , —NH—R—NHCO—C (R ′) ═CH ₂ , a group selected from aryl groups having 12 or less carbon atoms Here, R represents an alkylene group having 2 to 5 carbon atoms, R ′ represents hydrogen or a methyl group, and at least one of R ^{6 to} R ¹⁰ is —CH═CH ₂ group or —C (CH ₃ ). = CH ₂ group included.)
That is, the organic phosphorus compound is a compound including at least one —CH═CH ₂ group or —C (CH ₃ ) ═CH ₂ group which is a terminal unsaturated bond. This functional group is a functional group for bonding to the polyolefin resin (A) by irradiation with radiation. In addition, it is preferable to have two or more terminal unsaturated bonds in one molecule.

In the compound represented by the formula (I), the CH ₂ ═CY ¹ —Y ² — group specifically includes CH ₂ ═CH—CH ₂ —, CH ₂ ═CH—CH ₂ CH ₂ CH ₂ —, _{CH 2 = C (CH 3)} -CH 2 -, CH 2 = CHCOO-CH 2 CH 2 -, CH 2 = C (CH 3) COO-CH 2 CH 2 - and the like.

The aromatic hydrocarbon-based group R ¹ to R ⁴ in or monofunctional also contain a hetero atom, preferably an aromatic hydrocarbon group having 6 to 14 carbon atoms. Specifically, _-C 6 _{H 5} (phenyl _{group), - C 6 H 5 OH} ( hydroxyphenyl _{group), - C 6 H 5 -C} 6 H 5 OH ( hydroxybiphenyl group), _- CH _{2 C} 6 H ₅ (benzyl group), -α-C ₁₀ H ₇ (α-naphthyl group), -β-C ₁₀ H ₇ (β-naphthyl group) and the like.

The aromatic hydrocarbon group which may bifunctional contain heteroatoms R ^5, preferably an aromatic hydrocarbon group having a carbon number of 10 to 14. _{Specifically, -p-C 6 H 4 -p} -C 6 H 4 -, - p-C 6 H 4 -CH 2 -p-C 6 H 4 -, - p-C 6 H 4 -C ( _{CH 3) 2 -p-C 6} H 4 -, - p-C 6 H 4 -C (= O) -p-C 6 H 4 -, - p-C 6 H 4 -SO 2 -p-C 6 _{H 4 -, 2,6-C 10} H 6 <(2,6- naphthylene group).

Note that the aromatic hydrocarbon group in the present invention, for example, a phenyl group or _{-p-C 6 H 4 -p-} C 6 H 4 above _- not only aromatic hydrocarbon groups such as, for example, the above hydroxyphenyl group or _{-p-C 6 H 4 -SO 2} -p-C 6 H 4 - like, and also include groups containing heteroatoms such as more oxygen or sulfur in addition to an aromatic hydrocarbon radical To do.

  And as an organophosphorus compound of the said formula (I), the compound shown by following structural formula (I-1)-(I-18) is mentioned, for example.

  Said compound is compoundable by the method described in international publication WO2005 / 012415 pamphlet etc. For example, the compound of (I-1) is reacted by adding dropwise a solution of DMAc in which 4,4′-biphenyl alcohol and triethylamine are dissolved, to this solution, adding phosphorus oxychloride to dimethylacetamide (DMAc). Subsequently, it can obtain by making the liquid mixture of an allylamine and a triethylamine react.

In the compound represented by the formula (II), examples of the aryl group having 12 or less carbon atoms include —C ₆ H ₅ (phenyl group), —C ₆ H ₅ OH (hydroxyphenyl group), and —C ₆ H. _5- C ₆ H ₅ OH (hydroxybiphenyl group), -α-C ₁₀ H ₇ (α-naphthyl group), -β-C ₁₀ H ₇ (β-naphthyl group) and the like can be mentioned.

In addition, examples of the bifunctional aromatic hydrocarbon group that does not include the mobile hydrogen having 20 or less carbon atoms of Ar ₁ and Ar ₂ include -p-C ₆ H ₄ -and -p-C ₆ H _{4. -O -, - O-p-} C 6 H 4 -O -, - p-C 6 H 4 -p-C 6 H 4 -, - p-C 6 H 4 -CH 2 -p-C 6 H 4 _{-, - p-C 6 H} 4 -C (CH 3) 2 -p-C 6 H 4 -, - p-C 6 H 4 -C (= O) -p-C 6 H 4 -, - p- C ₆ H ₄ —SO ₂ —p—C ₆ H ₄ —, 2,6-C ₁₀ H ₆ <(2,6-naphthylene group) and the like can be mentioned. Here, as mobile hydrogen, it is easy to form hydrogen bonds such as —OH (hydroxyl group), —NHCO— (amide bond), —NHCOO— (urethane bond), etc. It means highly reactive hydrogen contained in a functional group that easily reacts to generate hydrogen.

  And as an organophosphorus compound of the said formula (II), the compound shown by following structural formula (II-1)-(II-23) is mentioned, for example. Among these, (II-1 to II-12) are examples in which n is zero, that is, there are two phosphorus atoms in one molecule. Further, (II-13 to II-20) is an example in which n is 1, that is, three phosphorus atoms in one molecule. Further, (II-21) to (II-23) are examples in which n is 2, that is, four phosphorus atoms in one molecule.

  Said compound is compoundable by the method described in international publication WO2005 / 087852 pamphlet etc. For example, the compound of (II-1) above uses 4,4′-dichlorobiphenyl as a starting material, reacts this with phosphorus oxychloride, and further reacts with allyl bromide to form an unsaturated group at the end. It can synthesize | combine by introduce | transducing.

  And it is preferable to contain 0.5-20 mass% of the said reactive organophosphorus flame retardant (B) in a resin composition, and 4-12 mass% is more preferable. If the content of the reactive organophosphorus flame retardant (B) is less than 0.5% by mass, the flame retardancy can hardly be improved, and further the crosslinking density of the resin composition is inferior, Physical properties such as strength, pressure resistance and heat resistance can hardly be improved. When the amount exceeds 20% by mass, the reactive organophosphorus flame retardant becomes excessive, and there is a possibility that unreacted monomer and decomposition gas of the reactive organophosphorus flame retardant may be generated or oligomerized bleed out. .

  It is preferable that the resin composition used for the arc extinguishing resin processed product of the present invention further contains a polyacetal resin (C). Polyacetal-based resins can generate pyrolysis gas with high arc extinguishing action, but are inferior in molding processability due to difficulty in molding by melt-kneading, and the generation amount of pyrolysis gas is high. Since pyrolysis gas has a relatively high contribution to the increase in internal pressure, the internal pressure in the arc extinguishing device tends to increase. By using the polyacetal-based resin and the polyolefin resin (A) in combination, the arc extinguishing performance can be improved without impairing the molding processability of the resin composition, and further, in the arc extinguishing apparatus during arc extinguishing An increase in internal pressure can be suppressed.

  In the polyacetal resin (C), the content of repeating units derived from oxymethylene is preferably 75 to 100 mol%, and more preferably 80 to 100 mol%. When the content of the repeating unit is less than 75 mol%, the arc extinguishing property is inferior and the arc cannot be extinguished quickly.

  As such a polyacetal resin, an oxymethylene-oxyethylene copolymer or an oxymethylene polymer is preferable, and an oxymethylene-oxyethylene copolymer or an oxymethylene polymer is particularly preferable because of excellent arc extinguishing properties. . However, polyoxyethylene has poor arc-extinguishing properties.

  And it is preferable that content of polyacetal type-resin (C) is 5-90 mass parts with respect to 100 mass parts of polyolefin resin (A), and 7-88 mass parts is more preferable. When the content of the polyacetal-based resin (C) is less than 5 parts by mass in the above proportion, the effect of the polyacetal-based resin (C) is poor, and the arc-extinguishing property can hardly be improved. The amount of gas generated increases and the internal pressure in the arc extinguishing device tends to increase.

  The resin composition used in the arc extinguishing resin processed product of the present invention may further contain a resin other than the resin such as a general-purpose thermoplastic resin. 0-15 mass parts is preferable with respect to 100 mass parts of said polyolefin resin (A), and, as for content of these resin, 0-12 mass parts is more preferable.

  Moreover, it is preferable that the said resin composition used for the arc extinguishing resin processed article of this invention contains a radiation crosslinking agent further. By containing a radiation cross-linking agent, the resin can be cross-linked into a three-dimensional network structure due to the bond between the radiation cross-linking agent and the resin by irradiation, so that the cross-linking density becomes dense and physical strength, pressure resistance, heat resistance, etc. Improved characteristics.

  As such a radiation cross-linking agent, a bifunctional or higher functional reaction such as melamine-based trimethallyl acrylate and triallyl acrylate, isocyanate tri (methyl) acrylate, which does not have an aromatic ring and easily generates hydrogen gas. A compound having a functional group. Specifically, triallyl isocyanurate, trimethallyl isocyanurate and oligomers obtained by radical oligomerization thereof, triallyl trimellitic acid, trimellitic acid trimethallyl ester, pyromellitic acid tetraallyl, pyromellitic acid tetrametall For example, N-N, N, N ′, N ′, N ″, N ″ -hexaallyl melamine, N, N, N ′, N ′, N ″, N ″ -hexamethallyl melamine and the like.

  And it is preferable to contain 0.5-20 mass% of said radiation crosslinking agents in a resin composition, and 1-12 mass% is more preferable. If the content of the radiation crosslinking agent is less than 0.5% by mass, the crosslinkability of the resin composition can hardly be improved. If the content exceeds 20% by mass, bleeding out due to the radiation crosslinking agent may occur. There is.

  The resin composition used in the arc extinguishing resin processed product of the present invention is at least one selected from reinforcing fibers, barium titanate whiskers, silica gel fine particles, boehmite, talc, magnesium carbonate and metal hydroxide. It is preferable to contain an inorganic filler (D). By containing the inorganic filler, the strength, pressure resistance and heat resistance of the arc extinguishing resin processed product can be improved, and the dimensional stability can be improved.

  For example, examples of the reinforcing fiber include glass fiber, carbon fiber, and metal fiber, and it is preferable to use glass fiber from the viewpoint of strength and adhesiveness with a resin or an inorganic filler. These reinforcing fibers may be used alone or in combination of two or more thereof, and may be treated with a known surface treatment agent such as a silane coupling agent. The glass fiber is preferably surface-treated and further coated with a resin. Thereby, adhesiveness with resin can further be improved.

  Moreover, as said metal hydroxide, if a particle size is 1-10 micrometers, the improvement of a dispersibility with resin is mentioned and aluminum hydroxide, boehmite, and magnesium hydroxide are preferable from the reason that an internal pressure raise can be suppressed.

  And it is preferable to contain 1-70 mass% of said inorganic fillers (D) in a resin composition, and 20-70 mass% is more preferable. When the content of the inorganic filler (D) is less than 1% by mass, the effect of the inorganic filler is hardly obtained.

  In addition, the resin composition used in the arc extinguishing resin processed product of the present invention is within the range that does not significantly impair the physical properties such as heat resistance, pressure resistance, arc extinguishing property, and strength, which are the objects of the present invention. Various conventional additive components other than the above, such as crystal nucleating agents, colorants, antioxidants, mold release agents, plasticizers, heat stabilizers, lubricants, and UV inhibitors can be added.

  The arc extinguishing resin processed product of the present invention can be obtained by irradiating the resin composition with radiation after molding.

  Conventionally known methods are used for molding the resin composition. For example, the resin composition may be melt-kneaded and pelletized, and then molded by conventionally known injection molding, extrusion molding, vacuum molding, inflation molding, or the like. it can. The melt-kneading can be performed using a normal melt-kneading machine such as a single or twin screw extruder, a Banbury mixer, a kneader, or a mixing roll. The kneading temperature is preferably 170 to 230 ° C. When the temperature is lower than 170 ° C., melt kneading is difficult, and when the temperature exceeds 230 ° C., the hydroxyl group of the resin composition is dissociated and the arc-extinguishing property is lowered. Especially, in this invention, after melt-kneading the resin composition containing the said polyolefin resin (A) and the said polyacetal-type resin (C) at 180-220 degreeC in inert atmosphere, it shape | molds, It is preferable to cool to ~ 60 ° C. By molding in this way, the polyacetal resin (C) in the polyolefin resin (A) is in the submicron order of 0.1 to 0.9 μm, in the form of sea-island or hexagonal cylinder (hexagonal). A resin molded article having a microphase separation structure dispersed in a cylinder shape or a lamellae shape is obtained. By forming the microphase-separated structure, the polyacetal resin (C) is easily pyrolyzed and a pyrolysis gas having a high arc extinguishing property can be emitted, so that the arc can be extinguished quickly. In this stage, since the crosslinking has not progressed at all, the extra spool portion at the time of molding can be recycled.

  And it can be set as the arc extinguishing resin processed product of this invention by irradiating the resin molded product obtained in this way with radiation. The microphase separation structure can be immobilized by a crosslinking reaction by irradiation with radiation.

  As the radiation applied to the resin molded product, α rays, γ rays, X rays, ultraviolet rays and the like can be used, and γ rays are preferable because of its high transparency and uniform irradiation.

  The radiation dose is preferably 10 kGy or more, more preferably 10 to 45 kGy. If it is this range, the arc-extinguishing resin processed product which is excellent in said physical property by bridge | crosslinking will be obtained. If the irradiation dose is less than 10 kGy, the formation of a three-dimensional network structure due to cross-linking becomes non-uniform, and the unreacted cross-linking agent may bleed out. On the other hand, if it exceeds 45 kGy, the internal distortion of the resin processed product due to the oxidative decomposition product remains, which may cause deformation or shrinkage.

  The arc extinguishing resin processed product of the present invention thus obtained is excellent in strength, pressure resistance, heat resistance, arc extinguishing properties, and flame retardancy, and can be suitably used as an arc extinguishing device for a circuit breaker. .

  Next, the circuit breaker of the present invention will be described.

  The circuit breaker of the present invention includes a fixed contact having a fixed contact, a movable contact having a movable contact that contacts the fixed contact, and opening and closing the fixed contact, and the fixed contact. And an arc extinguishing device made of the arc extinguishing resin processed product for extinguishing an arc generated when the movable contactor opens and closes.

  As an example of such a circuit breaker, for example, those shown in FIGS. 1 is a cutaway perspective view of a circuit breaker, FIG. 2 is a perspective view of an arc extinguishing device, and FIG. 3 is a cross-sectional view of the circuit breaker.

  In FIG. 1, the opposite end portion of the fixed contact 5 with which the power supply side terminal 4 is integrally formed is folded back in a U-shape along the movable contact 1, and the movable contact at the tip of the folded portion 5a. A fixed contact 7 that contacts one movable contact 6 is provided. An arc horn 9 for guiding an arc generated between the movable and fixed contacts 6 and 7 toward the arc extinguishing device is attached to the fixed contact 5.

  The arc extinguishing device includes a grit 2 and an arc extinguishing chamber 13. A plurality of grids (5 in the figure) are stacked on the insulator 12 at a predetermined interval, and the movable contact 1 is indicated by a solid line in FIG. 1 through a V-shaped notch 2a formed in the grid 2. It is configured to open and close between the closed position and the open position indicated by the chain line. Further, an arc extinguishing chamber 13 formed of the arc extinguishing resin processed product of the present invention is installed between the movable contact 1 and the grid 2.

  1 and 3, the insulator 12 includes a pair of left and right side walls 12a and connecting portions 12b and 12c that connect the side walls 12a and 12b at the upper and lower portions, respectively, and is integrally formed by arc-resistant melamine mold resin. Has been. On the opposing surfaces of the left and right side walls 12a, a strip 14 having a square cross section is formed in multiple stages so as to rise obliquely from the load side end face (the right end face in FIG. 3) of the side wall 12a. Is press-fitted into the groove 14.

  On the other hand, the arc extinguishing chamber 13 includes a pair of left and right side walls 13 a and a front wall 13 b that connects the upper end portions of the left and right side walls 13 a along an arc along the notch 2 a of the grid 2. In the arc extinguishing chamber 13, a partition wall 15 that partitions the arc extinguishing device and the opening / closing mechanism and an insulating cover 16 that covers the upper surface of the fixed contact 5 are integrally formed. The partition 15 is provided with a slit 15 a along the opening / closing movement path of the movable contact 1, and the insulating cover 16 is provided with a window hole 16 a for exposing the fixed contact 7. The arc extinguishing chamber 13 is combined from the right side of FIG. 3 so that the partition wall 15 is in contact with the end surface of the insulator side wall 12 a inside the insulator 12, and is supported on the fixed contact 5 via the insulating cover 16. The circuit breaker is fixed by being pressed by a body cover (not shown). In this state, the side wall 13a of the arc extinguishing chamber 13 covers both legs of the grid 2 located on both sides of the movable contact 1 (both sides of the notch 2a) from the inside, and the front wall 13b is as shown in FIG. The uppermost grid 2 is located at the back of the notch 2a.

  In the above configuration, when the current is interrupted, an arc is generated between the movable and fixed contacts 6 and 7, and this arc is drawn into the grid 2 to extinguish the arc. The side wall 13a is covered from the inside and shielded from the arc, so that this part is prevented from melting and scattering by the arc, and a highly extinguishing pyrolytic gas is generated from the side wall 13a adjacent to the arc. Arc cooling is accelerated and extinguishes quickly.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example, this invention is not limited to these Examples.

(Example 1)
67 parts by mass of a polyolefin resin (trade name; “EVAL-L104B” manufactured by Kuraray Co., Ltd.) containing 0.58 mol of hydroxyl group per mol of methylene group, and the content of repeating units derived from oxymethylene As a reactive organophosphorus flame retardant, 25 parts by mass of polyoxymethylene-oxyethylene copolymer (trade name; “TENAC-C 4520” manufactured by Asahi Kasei Co., Ltd.) having a mol of 90 mol% is mixed. 8 parts by mass of the compound of the above formula (I-14) was added and kneaded at 220 ° C. using a side flow type twin screw extruder (manufactured by Nippon Steel Co., Ltd.) to obtain resin pellets. Next, the resin pellets were dried at 80 ° C. for 7 hours, and then molded using an injection molding machine (manufactured by FUNUC: α50C) under conditions of a resin temperature of 215 ° C. and a mold temperature of 50 ° C. When the cross-sectional state of the molded body was observed with an SEM, a microphase separation state having a lamella spherulite and a uniform sea-island structure could be confirmed.

  Thereafter, the molded product was irradiated with 25 kGy of γ rays using cobalt 60 as a radiation source to obtain an arc-extinguishing resin processed product of Example 1. When the cross-sectional state of the arc extinguishing resin processed product was observed with an SEM, a lamellar spherulite and a micro phase separation state having a uniform sea-island structure could be confirmed.

(Example 2)
50 parts by mass of a polyolefin resin (trade name; “EVAL-L104B” manufactured by Kuraray Co., Ltd.) containing 0.58 mol of hydroxyl group per mol of methylene group, and the content of repeating units derived from oxymethylene After melting and mixing 20 parts by mass of a polyoxymethylene-oxyethylene copolymer (trade name; “Tenac-C 4520”, manufactured by Asahi Kasei Co., Ltd.) with 90 mol%, boehmite (trade name) "BMT-10" 10 parts by weight of Kawai Lime Industry Co., Ltd. and 15 parts by weight of silane-treated glass fiber (trade name; "03.JAFT2Ak25" manufactured by Asahi Fiber Glass Co., Ltd.) and the above as a reactive organic phosphorus flame retardant 5 parts by mass of the compound of the formula (II-3) was added and kneaded at 220 ° C. using a side flow type twin screw extruder (manufactured by Nippon Steel Co., Ltd.). The resin pellets were then dried at 80 ° C. for 7 hours, and then molded using an injection molding machine (FUNUC: α50C) under conditions of a resin temperature of 215 ° C. and a mold temperature of 50 ° C. When the cross-sectional state of this molded body was observed with an SEM, a microphase-separated state having a lamellar spherulite and a uniform sea-island structure could be confirmed.

  Thereafter, the molded product was irradiated with 25 kGy of γ rays using cobalt 60 as a radiation source to obtain an arc extinguishing resin processed product of Example 2. When the cross-sectional state of the arc extinguishing resin processed product was observed with an SEM, a lamellar spherulite and a micro phase separation state having a uniform sea-island structure could be confirmed.

(Example 3)
53 parts by mass of a polyolefin resin (trade name; “EVAL-L104B” manufactured by Kuraray Co., Ltd.) containing 0.58 mol of hydroxyl group per mol of methylene group and the content of repeating units derived from oxymethylene 20 parts by mass of a polyoxymethylene-oxyethylene copolymer (trade name: “TENAC-C 4520” manufactured by Asahi Kasei Co., Ltd.) having a N content of 90 mol% was melt mixed at 220 ° C. in an N ₂ atmosphere. . Next, 15 parts by mass of boehmite (trade name; “BMT-10” Kawai Lime Industry Co., Ltd.) as an inorganic filler and 12 parts by mass of the compound of the above formula (I-18) as a reactive organic phosphorus flame retardant are added. The resin pellets were obtained by kneading at 220 ° C. using a side flow type twin screw extruder (Nippon Steel Co., Ltd.) substituted with N ₂ gas. Then, the resin pellets at 80 ° C., dried 7 hours, an injection molding machine (FUNUC Co.: α50C) _{N 2} atmosphere using a resin temperature of 215 ° C., it was molded under the conditions of a mold temperature of 50 ° C. . When the cross-sectional state of the molded body was observed with an SEM, a microphase separation state having a lamella spherulite and a uniform sea-island structure could be confirmed.

Thereafter, the molded product was irradiated with 25 kGy of γ rays using cobalt 60 as a radiation source to obtain an arc extinguishing resin processed product of Example 2. When the cross-sectional state of the arc extinguishing resin processed product was observed with an SEM, a microphase separation state having a lamellar spherulite and a uniform sea-island structure could be confirmed (Comparative Example 1).
In Example 1, resin pellets were obtained by kneading under the same conditions as in Example 1 except that no reactive organophosphorous flame retardant was blended. The obtained resin pellets were dried at 80 ° C. for 7 hours, and then molded using an injection molding machine (FUNUC: α50C) at a resin temperature of 215 ° C. and a mold temperature of 50 ° C. for comparison. The arc extinguishing resin processed product of Example 1 was obtained.

(Comparative Example 2)
In Example 2, resin pellets were obtained by kneading under the same conditions as in Example 2 except that no reactive organophosphorous flame retardant was blended. The obtained resin pellets were dried at 80 ° C. for 7 hours, and then molded using an injection molding machine (FUNUC: α50C) at a resin temperature of 215 ° C. and a mold temperature of 50 ° C. for comparison. The arc extinguishing resin processed product of Example 2 was obtained.

(Comparative Example 3)
In Example 2, instead of the reactive organophosphorus flame retardant, an additive type organophosphorus flame retardant having no reactivity (trade name: “HCA-HQ” manufactured by Sanko Chemical Co., Ltd.) was used. In the same manner as in Example 2, an arc-extinguishing resin processed product of Comparative Example 3 was obtained.

(Comparative Example 4)
In Example 2, a brominated flame retardant (trade name; “Great Lakes pdbs-80” manufactured by Great Lakes) was used in place of the reactive organophosphorous flame retardant, and a comparative example was performed in the same manner as in Example 2. Four arc extinguishing resin processed products were obtained.

(Comparative Example 5)
In Example 2, instead of a polyolefin resin (trade name; “EVAL-l104B” manufactured by Kuraray Co., Ltd.) containing 0.58 mole of hydroxyl group per mole of methylene group, a polyethylene resin (trade name; “ An arc extinguishing resin processed product of Comparative Example 5 was obtained in the same manner as in Example 2 except that “HJ362” (manufactured by Nippon Polyethylene Co., Ltd.) was used.

(Comparative Example 6)
25 parts by mass of unsaturated polyester resin (trade name; “7527” manufactured by Upica Co., Ltd.), 35 parts by mass of Al (OH) ₃ , 5 parts by mass of a styrene-vinyl acetate copolymer, and t as a polymerization initiator -Glass fiber (trade name: “03.JAFT2Ak25” manufactured by Asahi Fiber Glass Co., Ltd.), kneaded with 0.3 parts by mass of butyl peroxide-Z and 4.7 parts by mass of a viscosity modifier with a kneader. 35 parts by mass was added and dispersed to obtain a bulk mold compound. This bulk mold compound was molded and polymerized at 140 to 150 ° C. to obtain an arc-extinguishing resin processed product of Comparative Example 6.

(Comparative Example 7)
99.8 parts by mass of nylon 6 resin (trade name: “UBE nylon 1015B” manufactured by Ube Industries, Ltd.) and 0.2 part by mass of an antioxidant (manufactured by Ciba Geigy: Irgano Irganox 1010) were kneaded. Resin pellets were obtained. And after drying the obtained resin pellet at 105 degreeC for 4 hours, it shape | molds on the conditions of the resin temperature of 260 degreeC and metal mold | die temperature of 85 degreeC using the injection molding machine (FUNUC company make: α50C), and compared. The arc extinguishing resin processed product of Example 7 was obtained.

  The moldability of the arc extinguishing resin processed products of Examples 1 to 3 and Comparative Examples 1 to 7 was evaluated. In addition, this arc extinguishing resin processed product was used as the arc extinguishing chamber 13 of the circuit breaker of FIG. 1, and a short circuit test, a heat resistance test, and a flame retardance test were performed.

  In the short-circuit test, in the open state, current is passed under the condition of three-phase 440V / 50kA to open the movable contact to generate an arc current. This arc current is interrupted (arc extinction) and the arc-extinguishing device is damaged. The presence or absence (internal pressure property) and surface state (heat resistance) were confirmed.

  The interruption property was determined to be acceptable when the short-circuit current was interrupted.

  Formability was evaluated by visually evaluating the presence or absence of problems such as foaming and nasal sagging at the time of molding.

  For flame retardancy, test specimens (length 5 inches, width 1/2 inches, thickness 3.2 mm) compliant with UL-94 test were prepared, the specimens were mounted vertically, and a 10 second indirect flame with a Bunsen burner. The later burning time was recorded. Furthermore, the second 10 second indirect flame after extinguishing and recording the burning time after flame contact again, the total burning time, the red burning time after the second extinguishing (growing) time and the presence or absence of dripping matter to ignite cotton, The determination was made according to the UL-94 test.

  For metal contamination, the contact resistance after being left in a 120 ° C. environment for 300 hours was measured, and if the contact resistance value was 50 mΩ or less, it was determined to be acceptable.

  The test results are summarized in Table 1.

  From the above results, the arc extinguishing resin processed products of Examples 1 to 3 are excellent in flame retardancy, heat resistance, and moldability, and the circuit breaker using the arc extinguishing device made of this arc extinguishing resin processed product. Can effectively extinguish the arc generated from the contact when the current is interrupted, and the arc-extinguishing chamber was not damaged during the extinction.

It is an example which shows the fracture | rupture perspective view of the circuit breaker of this invention. It is a perspective view of the arc-extinguishing chamber used for the circuit breaker. It is sectional drawing of the arc-extinguishing apparatus used for the circuit breaker.

Explanation of symbols

1: movable contact 2: grit 4: power supply side terminal 5: fixed contact 6: movable contact 7: fixed contact 9: arc horn 12: insulator 13: arc extinguishing chamber 14: groove

Claims (9)

  A part of hydrogen atoms in the methylene chain is substituted with a hydroxyl group, a polyolefin resin (A) containing 0.2 to 0.7 mol of hydroxyl group per 1 mol of methylene group, and a reactive organic compound having a terminal unsaturated bond An arc-extinguishing resin processed product obtained by subjecting a resin composition containing a phosphorus-based flame retardant (B) to radiation crosslinking after molding.   5 to 90 parts by mass of the polyacetal resin (C) in which the resin composition contains 75 to 100 mol% of a repeating unit derived from oxymethylene with respect to 100 parts by mass of the polyolefin resin (A). The arc extinguishing resin processed product according to claim 1, which is contained.   The resin composition contains 1 to 70% by mass of one or more inorganic fillers (D) selected from glass fiber, barium titanate whisker, silica gel fine particles, boehmite, talc, magnesium carbonate and metal hydroxide. The arc extinguishing resin processed product according to claim 1 or 2.   The arc extinguishing resin processed product according to any one of claims 1 to 3, wherein a latent heat of decomposition of the polyolefin resin (A) is 30 cal / g or more.   The arc-extinguishing resin processed product according to any one of claims 1 to 4, wherein the polyolefin resin (A) is an ethylene-vinyl alcohol copolymer. The reactive organophosphorous flame retardant (B) is an organophosphorus compound represented by the following formula (I) and / or the following formula (II), and is contained in an amount of 0.5 to 20% by mass in the resin composition. The arc extinguishing resin processed product according to any one of claims 1 to 5.

(In formula (I), R ^{1 to} R ⁴ each represents CH ₂ ═CY ¹ —Y ² — or a monofunctional aromatic hydrocarbon group that may contain a hetero atom, and R ⁵ represents a hetero atom. X ^{1 to} X ⁴ each represents a group selected from —O—, —NH—, and — (CH ₂ ═CY ¹ —Y ² ) N—. And at least one of X ^{1 to} X ⁴ contains —NH— or — (CH ₂ ═CY ¹ —Y ² ) N—, wherein at least one of R ^{1 to} R ⁴ and X ^{1 to} X ⁴ is CH. ₂ = CY ¹ -Y ² -is included, Y ¹ represents hydrogen or a methyl group, Y ² represents an alkylene group having 1 to 5 carbon atoms, or —COO—Y ³ —, where Y ³ represents carbon. Represents an alkylene group of formula 1-5.)

(In the formula (II), a bifunctional aromatic hydrocarbon system containing at least one P—C bond in one molecule, and Ar ₁ and Ar ₂ each containing no mobile hydrogen having 20 or less carbon atoms Represents a group, and n is an integer of 0 to 2. R ^{6 to} R ¹⁰ are —NHCH ₂ CH═CH ₂ , —N (CH ₂ CH═CH ₂ ) ₂ , —OCH ₂ CH═CH ₂ , respectively. _{-CH 2 CH = CH 2, -CH} 2 CH 2 OCH = CH 2, - (C 6 H 4) -CH = CH 2, -O (C 6 H 4) -CH = CH 2, -CH 2 (C _{6 H 4) -CH = CH 2} , -NH (C 6 H 4) -CH = CH 2, -N (CH 2 CH = CH 2) - (C 6 H 4) -CH = CH 2, -O- R—OOC—C (R ′) ═CH ₂ , —NH—R—NHCO—C (R ′) ═CH ₂ , a group selected from aryl groups having 12 or less carbon atoms R represents an alkylene group having 2 to 5 carbon atoms, R ′ represents hydrogen or a methyl group, and at least one of R ^{6 to} R ¹⁰ is —CH═CH ₂ group or —C (CH ₃ ) ═. Including CH ₂ groups)   The arc-extinguishing resin processed product according to any one of claims 2 to 6, wherein the polyacetal resin (C) is an oxymethylene-oxyethylene copolymer or an oxymethylene polymer.   The arc-extinguishing resin processed product according to any one of claims 2 to 7, wherein the polyacetal resin (C) is dispersed in the polyolefin resin (A) to form a microphase separation structure. A fixed contact having a fixed contact, a movable contact having a movable contact that contacts the fixed contact and opening / closing with respect to the fixed contact, and an opening / closing operation of the fixed contact and the movable contact In a circuit breaker comprising an arc extinguishing device for extinguishing an arc generated when
The circuit breaker, wherein the arc extinguishing device is made of the arc extinguishing resin processed product according to any one of claims 1 to 8.