JP2013120645A - Covered electric wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a covered electric wire excellent in sliding wear resistance and long-term heat resistance characteristics.SOLUTION: The covered electric wire is formed by covering a conductor with a resin composition containing (A) 100 parts by mass of a polyarylene sulfide resin, (B) 3.0-30 parts by mass of a silicone elastomer having no functional group, and (C) 0.05-2 parts by mass of a silane compound. It is preferable that the viscosity of a polyphenylene sulfide is 50-600 Pa s.

Description

  The present invention relates to a covered electric wire, and more particularly to a covered electric wire suitable for electric wiring in vehicles such as automobiles and trucks.

  Coated wires used in wire harnesses for automobiles, etc. have a structure in which a conductor is covered with a coating material (insulator), and the coating material is a thermoplastic resin that has excellent electrical properties, low dielectric constant, and low dielectric loss. A composition is used. As such a thermoplastic resin composition, a resin composition mainly composed of a polyvinyl chloride resin has been conventionally used because of its relatively high insulation resistance, low production cost, and excellent flame retardancy alone. Widely used. However, a thermoplastic resin composition containing a polyvinyl chloride resin has a problem that a toxic gas such as hydrogen chloride gas is generated when burned.

  Therefore, in recent years, an attempt has been made to use an olefin resin composition such as polyethylene as a coating material as an insulator not using a halide. And since this olefin-type resin composition does not have a flame retardance independently, metal hydrates, such as magnesium hydroxide, are mixed as a flame retardant, and the flame retardance is provided.

  However, an insulator mainly composed of an olefin-based resin composition has a problem that wear resistance decreases when a metal hydrate such as magnesium hydroxide is mixed. To reduce the wear resistance, it is necessary to reduce the amount of metal hydrate to be mixed. However, if it is necessary to focus on improving flame retardancy, a large amount of metal hydrate is mixed. Inevitably, the wear resistance was significantly reduced.

In order to solve the above problems, Patent Document 1 discloses polyphenylene sulfide as a flame retardant resin for a coating material as a coated electric wire having sufficient flame retardancy and excellent wear resistance without using a flame retardant. A covered electric wire using a resin is disclosed. Although a certain amount of wear resistance is obtained by the covered electric wire described in Patent Document 1, it is difficult to say that it has sufficient wear resistance because it contains a flexible resin.
In particular, coated wires used in automobile wire harnesses are rubbed due to vibration during vehicle travel, and the coating material on the surface is worn, causing short circuits. Hereinafter, it is called “sliding wear resistance”), but the covered electric wire described in Patent Document 1 is difficult to satisfy the requirement.
Further, in an automobile, especially around the engine is exposed to high temperatures for a long period of time, so that it is required to maintain heat resistance for a long period of time.

JP 2009-298976 A

  This invention is made | formed in view of the said prior art, The subject is providing the covered electric wire excellent in sliding abrasion resistance and long-term heat-resistant characteristic.

The present invention for solving the above problems is as follows.
(1) (A) 100 parts by mass of polyarylene sulfide resin;
(B) 3.0 to 30 parts by mass of a silicone elastomer having no functional group;
(C) A covered electric wire comprising a conductor coated with a resin composition containing 0.05 to 2 parts by mass of a silane compound.

(2) The coated electric wire according to (1), wherein the polyarylene sulfide has a viscosity of 50 to 600 Pa · s.

  According to the present invention, it is possible to provide a coated electric wire excellent in sliding wear resistance and long-term heat resistance.

It is a figure which shows the result of the long-term heat test in each Example and a comparative example with a graph.

The covered electric wire of the present invention comprises (A) 100 parts by mass of polyarylene sulfide resin, (B) 3.0 to 30 parts by mass of a silicone elastomer having no functional group, and (C) 0.05 to 2 parts by mass of a silane compound. A conductor is coated on the conductor.
First, each component of the resin composition used for coating the conductor will be described below.

[(A) Polyarylene sulfide resin (PAS resin)]
The PAS resin as the component (A) used in the present invention is a polymer compound mainly composed of — (Ar—S) — (wherein Ar is an arylene group) as a repeating unit, and is generally known in the present invention. A PAS resin having the molecular structure described above can be used.

  Examples of the arylene group include a p-phenylene group, m-phenylene group, o-phenylene group, substituted phenylene group, p, p′-diphenylene sulfone group, p, p′-biphenylene group, p, p′-. A diphenylene ether group, p, p′-diphenylenecarbonyl group, naphthalene group and the like can be mentioned. The PAS resin may be a homopolymer consisting only of the above repeating units, or a copolymer containing the following different types of repeating units may be preferable from the viewpoint of processability and the like.

  As the homopolymer, PPS using a p-phenylene sulfide group as an arylene group and a p-phenylene sulfide group as a repeating unit is preferably used. As the copolymer, among the arylene sulfide groups comprising the above-mentioned arylene groups, two or more different combinations can be used, and among them, a combination containing a p-phenylene sulfide group and an m-phenylene sulfide group is particularly preferably used. It is done. Of these, those containing 70 mol% or more, preferably 80 mol% or more of p-phenylene sulfide groups are suitable from the viewpoint of physical properties such as heat resistance, moldability and mechanical properties. Further, among these PAS resins, a high molecular weight polymer having a substantially linear structure obtained by condensation polymerization from a monomer mainly composed of a bifunctional halogen aromatic compound can be particularly preferably used. The (A) PAS resin used in the present invention may be a mixture of two or more different molecular weight PAS resins.

  In addition to the linear PAS resin, a partially branched or crosslinked structure is formed by using a small amount of a monomer such as a polyhaloaromatic compound having 3 or more halogen substituents when performing condensation polymerization. Examples thereof include polymers obtained by heating a polymer having a low molecular weight and a linear structure polymer having a low molecular weight at a high temperature in the presence of oxygen or the like to increase the melt viscosity by oxidative crosslinking or thermal crosslinking, thereby improving moldability. However, from the viewpoint of color and toughness, a polymer in which a branched structure or a crosslinked structure is formed is not preferable as the amount of the branched structure or the crosslinked structure is increased.

The melt viscosity (310 ° C./slip rate of 1000 sec ⁻¹ ) of the PAS resin as the base resin used in the present invention is preferably 50 to 600 Pa · s including the above mixed system, and more preferably in the range of 80 to 500 Pa · s. Some are particularly preferred because they have an excellent balance between mechanical properties and fluidity. If the melt viscosity is less than 50 Pa · s, the elongation and toughness may be insufficient, and if the melt viscosity exceeds 600 Pa · s, it may be difficult to coat cleanly and may cause problems.

[(B) Silicone elastomer having no functional group]
As the silicone elastomer as the component (B) used in the present invention, one having no functional group is used. The reason why one having no functional group is used is that, for example, when a silicone elastomer containing an epoxy group as a functional group is used, the slidability deteriorates. The reason is not necessarily clear, but it is presumed that OH groups are usually present on the metal surface, and if there are polar groups on the resin side, the affinity with the metal increases and the metal surface tends to adhere.

  The silicone elastomer having no functional group that can be used in the present invention is a silicone elastomer in which an organopolysiloxane is crosslinked, which is kneaded with a curing agent and thermally crosslinked, or in the presence of a catalyst, heated and irradiated with ultraviolet rays. A silicone elastomer in which at least one kind of organopolysiloxane having a reactive group is cross-linked, and does not contain functional groups such as epoxy functional group, amino functional group, polyether group, and carboxyl group at the side chain and terminal. Silicone elastomer. Typical examples of the organopolysiloxane include polydimethylsiloxane and polymethylphenylsiloxane, and examples thereof include polydimethyldiphenylsiloxane copolymer, polydimethylphenylmethylsiloxane copolymer, and polymethylphenyldiphenylsiloxane copolymer. As a silicone elastomer having no functional group, DY33-315 manufactured by Toray Dow Corning Co., Ltd. is commercially available.

  In this invention, the compounding quantity of (B) silicone elastomer which does not have a functional group is 3.0-30 mass parts with respect to 100 mass parts of (A) PAS resin, and 5.0-18 mass parts is preferable. . If the silicone elastomer is less than 3.0 parts by mass, the amount of resin wear in sliding with the metal part increases, which is not preferable. Further, the tensile fracture strain retention rate by the heat resistance test is low, and the effect of improving ductility is poor, which is not preferable. On the other hand, when the blending amount of the silicone elastomer exceeds 30 parts by mass, it is not preferable because offgassing and processing difficulty occur, and a decrease in tensile strength increases.

[(C) Silane compound]
The silane compound used as the component (C) in the present invention is used for improving elongation. In particular, the resin composition according to the present invention is an essential component for imparting toughness because no filler is added.
The silane compound is not particularly limited, and examples thereof include alkoxysilanes such as epoxyalkoxysilane, aminoalkoxysilane, vinylalkoxysilane, and mercaptoalkoxysilane, and one or more of these are used. In addition, as for carbon number of an alkoxy group, 1-10 are preferable, Most preferably, it is 1-4.

  Examples of the epoxyalkoxysilane include γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and the like.

  Examples of aminoalkoxysilane include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, N- (β-aminoethyl)- Examples thereof include γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-diallylaminopropyltrimethoxysilane, and γ-diallylaminopropyltriethoxysilane.

  Examples of vinylalkoxysilane include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, and the like.

  Examples of mercaptoalkoxysilanes include γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane.

  Of these, epoxyalkoxysilane and aminoalkoxysilane are preferable, and γ-aminopropyltriethoxysilane is particularly preferable.

  In this invention, the compounding quantity of (C) silane compound is 0.05-2 mass parts with respect to 100 mass parts of (A) PAS resin, and 0.1-1.5 mass parts is preferable. When the blending amount of the silane compound is less than 0.05 parts by mass, the compatibility is poor and problems such as molding peeling may occur, and the burr suppressing ability is insufficient. Moreover, when the compounding quantity of a silane compound exceeds 2 mass parts, problems, such as generating gas increasing, may arise.

[Other ingredients]
The resin composition according to the present invention includes a flame retardant, a flame retardant aid, an antioxidant, a metal deactivator, other anti-aging agent, a lubricant, a UV absorber, and a stabilizer as long as the effects of the present invention are not hindered. Further, it may contain a polymer such as a plasticizer, an anti-aging agent, a pigment, a dye, a colorant, an antistatic agent, a foaming agent, other resins, or an additive.

The covered electric wire of the present invention is formed by coating a conductor with the above resin composition. That is, the resin composition can be produced by melt-mixing various additives as necessary, and coating the obtained composition on the conductor surface using an extruder or the like according to a conventional method. As a means for mixing the composition, compoundable equipment such as an extruder, a Henschel mixer, a kneader, a shaft kneader, a Banbury mixer, and a roll mill can be used.
Further, the diameter and material of the conductor are not particularly limited, and can be appropriately determined according to the application. Further, the thickness of the coating layer obtained by coating the resin composition is not particularly limited, and can be appropriately determined in consideration of the conductor diameter and the like.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

[Examples 1 to 4, Comparative Examples 1 to 7]
(A)-(C) component was mixed by the compounding part number shown in Table 1, and the resin composition was obtained.
Each component used is as follows.
PPS: Kureha Co., Ltd. Fortron KPS W214A
Silicone elastomer: Toray Dow Corning Co., Ltd., DY33-315
Epoxy group-containing silicone elastomer: Toray Fill E601 manufactured by Toray Dow Corning Co., Ltd.
Silicone oil: Toray Fill F202 manufactured by Toray Dow Corning
γ-aminopropyltriethoxysilane: Shin-Etsu Chemical Co., Ltd., KBE-903P
In addition, the silicone oil used in Comparative Examples 4 to 5 is a silicone oil supported on inorganic powder at a high concentration (60%). Therefore, although the compounding quantity of the silicone oil in Table 1 is a large numerical value because it contains inorganic powder, the compounding quantity of only the silicone oil is 5.3 parts by mass in each of Comparative Examples 4 to 5, 11.2 parts by mass.

(Preparation of pellets-evaluation test)
Using the resin composition obtained as described above, it was put into a twin-screw extruder having a cylinder temperature of 320 ° C., and melt-kneaded to prepare resin composition pellets.
Next, various evaluations were performed by the following methods using the prepared pellets.

[Sliding wear resistance test]
A test piece having a width of 13 mm, a thickness of 2 mm, and a length of 130 mm was prepared from the pellets using an injection molding machine at a cylinder temperature of 320 ° C. and a mold temperature of 150 ° C. Next, a reciprocating sliding test is performed in a state where the side surface of a cylindrical metal (SUS304) having a diameter of 10 mm and a height of 20 mm is in contact with the obtained test piece, and the amount of resin abrasion (weight change and dimensional change) is examined. It was evaluated. The reciprocating sliding was measured under the indoor conditions of 23 ° C. and 50% RH under the conditions of a sliding stroke of 8 cm, a load of 1 kgf, and a speed of 5.3 cm / sec. The change in weight indicates the change in the weight of the test piece before and after the test, and the change in dimension indicates the change in the thickness of the test piece before and after the test. Table 1 shows the measurement results of the weight change and the dimensional change.

[Bending test]
In each of the examples and comparative examples, a test piece (width 10 mm, thickness 4 mmt) according to ISO 3167 was prepared by injection molding at a cylinder temperature of 320 ° C. and a mold temperature of 150 ° C., and bending strength (FS) according to ISO 178. The flexural modulus (FM) was measured. The measurement results are shown in Table 1.

[Long-term heat test]
In each of Examples 1 to 3 and Comparative Examples 1 to 5, a dumbbell test piece having a thickness of 4 mmt was produced at a cylinder temperature of 320 ° C. and a mold temperature of 150 ° C. by injection molding, and the test piece was set at 180 ° C. The sample was left in an oven and taken out after 100 hours, 300 hours, 500 hours, and 1000 hours, respectively, and the tensile elongation (TE) was measured according to ISO 527-1, 2 (tensile speed: 5 mm / min). Moreover, tensile elongation was similarly measured about the test piece which cannot be put into oven as an initial state. The result of the tensile elongation retention is shown in FIG.

From Table 1, it can be seen that in Examples 1 to 4, the amount of resin wear is small and the sliding wear resistance is excellent as compared with Comparative Examples 1 to 7. Further, in each of the examples and comparative examples, since the same degree of bending characteristics is exhibited as long as the blending number of the component (B) is the same, a silicone elastomer having no functional group may be used as the component (B). It can be seen that the bending properties are not affected.
Moreover, it turns out that in Examples 1-3, it is excellent in long-term heat-resistant characteristic compared with Comparative Examples 1-5 from FIG.
Furthermore, the comparative example 7 which made only the compounding part number of (B) component outside the range prescribed | regulated to this invention (less than a minimum) was inferior in the sliding wear-resistance test.

Claims (2)

(A) 100 parts by mass of polyarylene sulfide resin;
(B) 3.0 to 30 parts by mass of a silicone elastomer having no functional group;
(C) A covered electric wire comprising a conductor coated with a resin composition containing 0.05 to 2 parts by mass of a silane compound.   The coated electric wire according to claim 1, wherein the polyarylene sulfide has a viscosity of 50 to 600 Pa · s.

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