JP2012113901A - Insulation wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insulation wire which has an insulation layer including a crosslinked acrylic rubber and is excellent in flexibility and heat resistance.SOLUTION: In an insulation wire in which a periphery of a conductor is coated with an insulation layer including a crosslinked acrylic rubber, the insulation layer contains a stabilizer having a melting point of 150°C or above. The content of the stabilizer is preferably within a range from 0.1 to 20 pts.mass relative to 100 pts.mass of the crosslinked acrylic rubber. The stabilizer is preferably a hindered phenolic antioxidant.

Description

  The present invention relates to an insulated wire, and more particularly to an insulated wire suitable for automobiles, electrical / electronic devices, and the like.

  Various properties such as mechanical properties, flame retardancy, heat resistance, and cold resistance are required for members and insulating materials used in automobiles, electrical / electronic devices, and the like. Conventionally, an insulated wire in which an insulating layer is formed of a composition containing acrylic rubber has been proposed as a heat-resistant insulating material having flexibility (Patent Document 1).

JP 2009-269979 A

  Conventionally proposed heat-resistant materials include an example in which polyolefin is mixed with acrylic rubber as seen in Patent Document 1, but this insulated wire has a problem of insufficient heat resistance.

  The problem to be solved by the present invention is to provide an insulated wire having an excellent heat resistance in an insulated wire having an insulating layer containing a crosslinked acrylic rubber having excellent heat resistance.

  In order to solve the above problems, the insulated wire according to the present invention is an insulated wire in which the periphery of the conductor is covered with an insulating layer containing a cross-linked acrylic rubber, and the insulating layer contains a stabilizer having a melting point of 150 degrees or more. Is a summary.

  In the insulated wire, the stabilizer is preferably a hindered phenol-based antioxidant. The said insulated wire WHEREIN: It is preferable that content of the said stabilizer exists in the range of 0.1-20 mass parts with respect to 100 mass parts of said crosslinked acrylic rubber. In the above insulated wire, the insulating layer may further contain a flame retardant.

  In the insulated wire according to the present invention, the insulating layer containing the crosslinked acrylic rubber contains a stabilizer having a melting point of 150 ° C. or more. For this reason, the fluidity of the stabilizer in the crosslinked acrylic rubber is low even at high temperatures, and the dispersion state of the stabilizer in the crosslinked acrylic rubber at the time of blending is maintained even at high temperatures. Therefore, the insulated wire according to the present invention is excellent in heat resistance.

  Next, an embodiment of the present invention will be described in detail.

  The insulated wire according to the present invention has a conductor and an insulating layer covering the periphery of the conductor. The insulating layer contains a crosslinked acrylic rubber and a stabilizer.

  The crosslinked acrylic rubber is obtained by crosslinking uncrosslinked acrylic rubber (raw rubber). Uncrosslinked acrylic rubber (raw rubber) is an elastic body mainly composed of an acrylate ester, and the crosslinked acrylic rubber obtained by crosslinking this is excellent in heat resistance and flexibility. The uncrosslinked acrylic rubber can be crosslinked by heating, but if necessary, a crosslinking agent (crosslinking agent) may be used for the uncrosslinked acrylic rubber.

  The acrylic rubber is mainly composed of an acrylic ester and is copolymerized with other monomer components as required. Examples of the acrylate ester include ethyl acrylate, butyl acrylate, methoxyethyl acrylate, and the like. Examples of other monomer components include 2-chloroethyl vinyl ether and acrylonitrile. Examples of the comonomer for crosslinking the acrylic rubber include halogen-containing compounds such as 2-chloroethyl vinyl ether, epoxy compounds such as glycidyl acrylate and allyl glycidyl ether, and diene compounds such as ethylidene norbornene. .

  The crosslinking agent can be appropriately selected according to the type of acrylic rubber monomer, crosslinking conditions, and the like, and is not particularly limited. Examples of the crosslinking agent include radical generators such as organic peroxides, metal soaps, amines, thiols, thiocarbamates, and organic carboxylic acids. The crosslinking agent is preferably an organic peroxide-based crosslinking agent such as an organic peroxide from the viewpoint of improving the crosslinking rate.

  Examples of the organic peroxide include dialkyl peroxides such as dihexyl peroxide, dicumyl peroxide, t-butylcumyl peroxide, and 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane. Examples thereof include peroxyketals such as oxide and n-butyl 4,4-di (t-butyl peroxide) valerate.

  As the stabilizer, a stabilizer having a melting point of 150 degrees or more is used. By using a high melting point stabilizer, the fluidity of the stabilizer in the crosslinked acrylic rubber is low even at high temperatures, and the dispersion state of the stabilizer in the crosslinked acrylic rubber during blending is maintained even at high temperatures. Thereby, since the stabilizer can sufficiently exhibit its function even at high temperatures, the heat resistance of the crosslinked acrylic rubber can be enhanced.

  From the viewpoint of lowering the fluidity of the stabilizer at high temperatures, the melting point of the stabilizer is more preferably 160 degrees or more, and further preferably 180 degrees or more. On the other hand, from the viewpoint of availability, the upper limit of the melting point of the stabilizer is preferably 300 degrees or less. More preferably, it is 280 degrees, and more preferably 270 degrees.

  Examples of the stabilizer include hindered phenol-based antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants. Of these, hindered phenolic antioxidants are particularly preferred because of their high stabilizing effect. The hindered phenol-based antioxidant is a phenol-based antioxidant having a tertiary butyl group at the 2,6-position of the phenol hydroxyl group.

  As the hindered phenol-based antioxidant, “Irganox 3114” (melting point 220 ° C.), “Irganox 1098” (melting point 160 ° C.), “Irganox 1330” (melting point 240 ° C.), “ “Irganox 3790” (melting point 162 ° C.), “AO-20” (melting point 220 ° C.), “AO-30” (melting point 186 ° C.), “AO-40” (melting point 210 ° C.), “AO— 330 "(melting point 244 degrees)," Sinox 326M "(melting point 244 degrees) manufactured by Sipro Kasei Co., Ltd.," Sumilyzer BBM-S "(melting point 209 degrees) manufactured by Sumitomo Chemical.

  Phosphorous antioxidants include “PEP-24G” (melting point 165 degrees), “PEP-36” (melting point 237 degrees), “2112” (melting point 183 degrees) manufactured by Adeka Corporation, “Song” manufactured by Sumitomo Chemical Co., Ltd. Nox 1680 "(melting point 181 degrees)," Song Knox 6260 "(melting point 175 degrees), and the like.

  Examples of the sulfur-based antioxidant include “Sinox BCS” (melting point: 164 ° C.) manufactured by Sipro Kasei Co., Ltd. and “Sumilyzer WXR” (melting point: 160 ° C.) manufactured by Sumitomo Chemical.

  It is preferable that the compounding quantity of a stabilizer exists in the range of 0.1-20 mass parts with respect to 100 mass parts of crosslinked acrylic rubber. If the blending amount is less than 0.1 part by mass, the heat resistance improvement effect may not be sufficiently exhibited. On the other hand, if the blending amount exceeds 20 parts by mass, the dispersibility of the stabilizer in the crosslinked acrylic rubber tends to deteriorate. That is, since there are too many compounding quantities of a stabilizer, a stabilizer becomes difficult to mix uniformly with crosslinked acrylic rubber, and there exists a possibility that a stabilizer may appear on the outer side of an insulating layer. As a compounding quantity of a stabilizer, More preferably in the range of 0.2-18 mass parts with respect to 100 mass parts of crosslinked acrylic rubber, More preferably, it exists in the range of 0.5-15 mass parts.

  In addition to the crosslinked acrylic rubber and stabilizer, the insulating layer may contain various additives as long as the properties of the insulating layer are not impaired. As such an additive, the common additive used for the insulating layer of an insulated wire can be mentioned. Specific examples include flame retardants, fillers, antioxidants, anti-aging agents, and pigments. Examples of the flame retardant include metal hydrate, brominated flame retardant, antimony trioxide and the like. These flame retardants may be used alone or in combination of two or more.

  Examples of the metal hydrate include magnesium hydroxide and aluminum hydroxide. Magnesium hydroxide may be any one obtained by pulverizing a naturally occurring mineral, one synthesized from seawater by a crystal growth method, or one synthesized by reaction of magnesium chloride and calcium hydroxide.

  The average particle size of the metal hydrate is preferably in the range of 0.1 to 20 μm. If the average particle size is less than 0.1 μm, secondary aggregation is likely to occur, and mechanical properties are likely to deteriorate. When the average particle size exceeds 20 μm, it tends to appear on the surface of the insulating layer and tends to be poor in appearance.

  It is preferable that the compounding quantity of a metal hydrate exists in the range of 0.1-200 mass parts with respect to 100 mass parts of crosslinked acrylic rubber. If the compounding amount of the metal hydrate is less than 0.1 parts by mass, the flame retardancy may be insufficient, and if the compounding amount of the metal hydrate exceeds 200 parts by mass, the dispersion may be poor. .

  Of the metal hydrate, the surface of magnesium hydroxide may be surface-treated with a surface treatment agent. When the magnesium hydroxide is surface-treated, the dispersibility in the crosslinked acrylic rubber is excellent. Examples of the surface treatment agent for magnesium hydroxide include homopolymers of α-olefins such as 1-heptene, 1-octene, 1-nonene and 1-decene, mutual copolymers, and mixtures thereof. it can.

  The surface treatment agent for magnesium hydroxide may be modified. Examples of the modifier include unsaturated carboxylic acids or derivatives thereof. Specific examples of the modifier include maleic acid and fumaric acid. Examples of the derivative include maleic anhydride (MAH), maleic acid monoester, maleic acid diester and the like. These may be used alone or in combination of two or more. Of these, maleic acid and maleic anhydride are preferred. Examples of a method for introducing an acid into the surface treatment agent include a graft method and a direct method. Moreover, as an acid modification amount, it is 0.1-20 mass% with respect to a polymer, Preferably it is 0.2-10 mass%, More preferably, it is 0.2-5 mass%.

  A method for treating the surface treatment agent with respect to magnesium hydroxide is not particularly limited. As a treatment method, surface treatment may be performed on magnesium hydroxide having a predetermined particle diameter, or a surface treatment agent may be treated at the same time when magnesium hydroxide is synthesized. Moreover, as a processing method, the wet process using a solvent may be sufficient and the dry process which does not use a solvent may be sufficient. In the wet treatment, examples of suitable solvents include aliphatic solvents such as pentane, hexane, and heptane, and aromatic solvents such as benzene, toluene, and xylene. Furthermore, a surface treating agent may be kneaded when preparing the composition for forming the insulating layer.

  As the brominated flame retardant, ethylene bis-tetrabromophthalimide, ethylene bis-tribromophthalimide-based brominated flame retardant having a phthalimide structure and the like are suitable. A brominated flame retardant having a phthalimide structure may be used alone, but can also be used in combination with the following brominated flame retardants. For example, ethylene bis (pentabromobenzene), tetrabromobisphenol A (TBBA), hexabromocyclododecane, TBBA carbonate oligomer, TBBA epoxy oligomer, brominated polystyrene, TBBA bis (dibromopropyl ether), poly (dibromopropyl ether), Examples include hexabromobenzene.

  Antimony trioxide is used as a flame retardant aid for brominated flame retardants. The purity of antimony trioxide is preferably 99% or more. As a method for producing antimony trioxide, there is a method obtained by pulverizing antimony trioxide produced as a mineral. In that case, the average particle diameter of antimony trioxide is preferably 3 μm or less, and more preferably 1 μm or less.

  Antimony trioxide may be subjected to a surface treatment. Examples of the surface treatment agent for antimony trioxide include silane coupling agents, titanate coupling agents, higher fatty acids such as stearic acid, higher fatty acid esters, higher fatty acid metal salts, and olefinic waxes. The olefin wax is an α-olefin such as 1-heptene, 1-octene, 1-nonene, 1-decene, a homopolymer or a copolymer thereof, or a mixture thereof. As the usage-amount (surface treatment amount) of a surface treating agent, the range of 0.1-10 mass parts is preferable with respect to 100 mass parts of antimony trioxide, More preferably, it is 0.1-5 mass parts.

  The surface treatment agent for antimony trioxide may be modified. As the modifier, an unsaturated carboxylic acid or a derivative thereof can be used. Specific examples of the unsaturated carboxylic acid include maleic acid and fumaric acid. Examples of the unsaturated carboxylic acid derivative include maleic anhydride (MAH), maleic acid monoester, maleic acid diester and the like. Of these, maleic acid, maleic anhydride and the like are preferable. These surface treating agent modifiers may be used alone or in combination of two or more.

  Examples of a method for introducing an acid into the surface treatment agent include a graft method and a direct method. Moreover, as an acid modification amount, it is 0.1-20 mass% of a surface treating agent, Preferably it is 0.2-10 mass%, More preferably, it is 0.2-5 mass%.

  The surface treatment method of the surface treatment agent for antimony trioxide is not particularly limited. As a treatment method, for example, surface treatment may be performed on antimony trioxide having a predetermined particle diameter in advance, or treatment may be performed simultaneously with pulverization. Moreover, as a processing method, the wet process using a solvent may be sufficient and the dry process which does not use a solvent may be sufficient. In the wet treatment, examples of suitable solvents include aliphatic solvents such as pentane, hexane, and heptane, and aromatic solvents such as benzene, toluene, and xylene. Moreover, when preparing the composition which forms an insulating layer, you may knead | mix a surface treating agent simultaneously with another material.

  When the brominated flame retardant and antimony trioxide are used in combination as the flame retardant, the total amount of both is preferably in the range of 0.1 to 100 parts by mass with respect to 100 parts by mass of the acrylic rubber. If the total amount of these flame retardants is less than 0.1 parts by mass with respect to 100 parts by mass of the acrylic rubber, the flame retardancy may be insufficient, and if the total amount exceeds 100 parts by mass, the dispersion is poor. There is a risk.

  The ratio when the brominated flame retardant and antimony trioxide are used in combination is the mass ratio of brominated flame retardant and antimony trioxide, and it is within the range of brominated flame retardant / antimony trioxide = 1-5. Is preferable because it is suitable and excellent in flame retardancy. When the ratio between the brominated flame retardant and antimony trioxide is out of the above range, if the blending amount of antimony trioxide is too large, the cost may increase. If the amount of antimony trioxide is too small, flame retardancy may be reduced.

  A more preferable ratio (mass ratio) of brominated flame retardant and antimony trioxide is in the range of brominated flame retardant / antimony trioxide = 1.5 to 4.5, more preferably brominated flame retardant / trioxide. Antimony is in the range of 2-4.

  Next, the manufacturing method of an insulated wire is demonstrated.

  Insulated wires are made by kneading a composition containing acrylic rubber, a stabilizer, and a flame retardant, a crosslinking agent, and other additives that are blended as necessary, and then extruding this around the conductor to surround the conductor. After the insulating layer is formed, the acrylic rubber of the insulating layer is crosslinked by means such as heating.

  As the kneading method, for example, a Banbury mixer, a pressure kneader, a kneading extruder, a biaxial kneading extruder, a method of melting and kneading with a normal kneading machine such as a roll, and the like can be used. The kneading is preferably performed at about 50 to 60 ° C. by water cooling or the like. As the extruder, an electric wire extrusion molding machine or the like used for manufacturing a normal insulated wire can be used.

  In the insulated wire which concerns on this invention, what is used for a normal insulated wire can be utilized for a conductor. For example, a single wire conductor or a stranded wire conductor made of a copper-based material or an aluminum-based material can be used. Moreover, the diameter of a conductor, the thickness of an insulating layer, etc. are not specifically limited, It can determine suitably according to the use etc. of an insulated wire. The insulating layer may be a single layer or may be composed of two or more layers.

  The insulated wire of the present invention can be used for insulated wires used in automobiles, electronic / electrical equipment. It is particularly suitable as an insulated wire for applications that require high heat resistance and flame resistance. For example, in an insulated electric wire for automobiles, applications requiring such high heat resistance include high voltage and large current applications such as a power cable connecting an engine and a battery of a hybrid vehicle or an electric vehicle.

  Examples of the present invention and comparative examples are shown below.

[Examples 1-8, Comparative Examples 1-9]
Each component was mixed at room temperature using a Banbury mixer so as to have the blending composition shown in Tables 1 and 2. Thereafter, using an extruder, an insulating layer was formed by extruding the outer periphery of an annealed copper stranded wire conductor (cross-sectional area of 0.5 mm ² ) of 7 annealed copper wires to a thickness of 0.2 mm. Then, heat treatment was performed at 180 ° C. for 4 hours to complete the crosslinking, and insulated wires of Examples 1 to 8 and Comparative Examples 1 to 9 were obtained. The obtained insulated wire was evaluated by performing a cold resistance test and a heat resistance test. The results are shown in Tables 1 and 2. In addition, each component of Table 1 and Table 2, a cold resistance test method, and a heat resistance test method are as follows.

[Ingredients in Tables 1 and 2]
・ Acrylic rubber 1 [Product name "4200", manufactured by Electrochemical Co., Ltd.]
・ Acrylic rubber 2 [manufactured by Nippon Zeon, trade name “Nipol AR14”]
・ Acrylic rubber 3 [made by Unimatec, trade name “A-5098”]
・ Acrylic rubber 4 [made by Unimatec, trade name “PA-422”]
・ Polypropylene (Nippon Polypro, trade name “EC7”)
-PE 5% coated water mug [Surface treatment magnesium hydroxide, surface treatment agent: polyethylene, surface treatment amount: 5% by mass]
As the surface-treated magnesium hydroxide, magnesium hydroxide having an average particle diameter of 1.0 μm by a crystal growth method was used. Moreover, the product name "800P" by Mitsui Chemicals, Inc. was used for the surface treatment agent polyethylene. The surface treatment amount is mass% with respect to magnesium hydroxide.
・ Brominated flame retardant [Ethylenebis (pentabromobenzene)]
・ Antimony trioxide [manufactured by Yamanaka Sangyo Co., Ltd., trade name “antimony trioxide”]
Stabilizer 1 [Ciba Japan, trade name “Irganox 3114” (melting point: 220 degrees)]
Stabilizer 2 [Adeka Co., Ltd., trade name “AO-20” (melting point: 220 degrees)]
Stabilizer 3 [Cypro Kasei Co., Ltd., trade name “Sinox BCS” (melting point: 164 degrees)]
Stabilizer 4 [manufactured by Sumitomo Chemical Co., Ltd., trade name “Sumilyzer BBM-S” (melting point 209 degrees]]
Stabilizer 5 [manufactured by Sumitomo Chemical Co., Ltd., trade name “Sumilyzer TPL-R” (melting point: 37 ° C.]]
・ Stabilizer 6 [manufactured by Sumitomo Chemical Co., Ltd., trade name “Sumilyzer TPM” (melting point 49 ° C.]]
・ Crosslinking agent [Nippon Yushi Co., Ltd., trade name “Perhexyl D” (di-t-hexyl peroxide)]

[Cold resistance test method]
This was performed in accordance with JIS C3055. That is, the produced insulated wire was cut into a length of 38 mm to obtain a test piece. The test piece was mounted on a cold resistance tester, cooled to a predetermined temperature, hit with a hitting tool, and the state after hitting the test piece was observed. Using five test pieces, the temperature at which all five test pieces were broken was defined as the cold resistant temperature.

[Heat resistance test method]
The wire coating was peeled off, the conductor was pulled, and the insulation coating was removed about 100 mm in length to obtain a test piece. The test piece was subjected to a deterioration test at 200 ° C. for 10 days, and then a tensile test was performed. A case where the residual elongation rate was 50% or more was evaluated as pass (◯), and a case where the elongation percentage was less than 50% was determined as reject (x).

  As shown in Table 1, it was confirmed that all of the insulated wires in Examples 1 to 8 had good cold resistance and heat resistance of the wires, and were excellent in flexibility and heat resistance. On the other hand, although the insulated wire of Comparative Examples 1-9 had cold resistance and was flexible, it was confirmed that all the heat resistances were unacceptable and inferior in heat resistance.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

Claims (4)

  An insulated wire in which a conductor is covered with an insulating layer containing a crosslinked acrylic rubber, wherein the insulating layer contains a stabilizer having a melting point of 150 degrees or more.   The insulated wire according to claim 1, wherein the stabilizer is a hindered phenol-based antioxidant.   The insulated wire according to claim 1 or 2, wherein a content of the stabilizer is in a range of 0.1 to 20 parts by mass with respect to 100 parts by mass of the crosslinked acrylic rubber.   The insulated wire according to any one of claims 1 to 3, wherein the insulating layer further includes a flame retardant.