JP2015069874A - Insulation electric wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insulation electric wire having an insulation layer including crosslinked silicone rubber, excellent in battery liquid resistance.SOLUTION: Regarding an insulation electric wire in which the circumference of a conductor is coated with an insulation layer including crosslinked silicone rubber, the insulation layer includes a filler surface-treated with an amino-based silane coupling agent.

Description

  The present invention relates to an insulated wire, and more particularly to an insulated wire that is suitably used in automobiles, electrical equipment, electronic devices, and the like.

  Insulating materials for insulated wires used in vehicles such as automobiles are required to have various characteristics such as mechanical characteristics, flame retardancy, heat resistance, and cold resistance. Conventionally, as this type of insulating material, a material containing halogen such as a compound containing a vinyl chloride resin or a halogen-based flame retardant is often used.

  Since this type of insulating material contains halogen, corrosive gas may be generated when discarded by incineration. Therefore, there is an attempt to use an insulating material that does not contain halogen from the viewpoint of environmental protection.

  For example, Patent Document 1 describes that a non-halogen insulating material in which aluminum hydroxide is blended with uncrosslinked silicone rubber is used as an insulating material for an insulated wire. Silicone rubber is heated and used as a crosslinked silicone rubber.

Japanese Patent No. 3555101

  However, an insulated wire using a crosslinked silicone rubber as an insulating layer has a problem of poor battery liquid resistance. Therefore, it is desired to improve the battery liquid resistance of insulated wires.

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

In order to solve the above problems, the insulated wire according to the present invention is:
In an insulated wire whose conductor is covered with an insulating layer containing a crosslinked silicone rubber,
The gist is that the insulating layer contains a filler surface-treated with an amino-based silane coupling agent.

  In the insulated wire, the amino silane coupling agent is preferably at least one of 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane.

  The said insulated wire WHEREIN: It is preferable that the surface treatment amount with respect to the filler of the said amino-type silane coupling agent exists in the range of 0.1-5 mass% of the total amount of a silane coupling agent and a filler.

  In the insulated wire, the filler is preferably at least one of calcium carbonate and barium sulfate.

  The said insulated wire WHEREIN: It is preferable that content of the said filler exists in the range of 0.1-100 mass parts with respect to 100 mass parts of crosslinked silicone rubber.

  The said insulated wire WHEREIN: It is preferable that the average particle diameter of the said filler is 1 micrometer or less.

  The insulated wire according to the present invention is an insulated wire whose conductor is covered with an insulating layer containing a crosslinked silicone rubber, wherein the insulating layer contains a filler whose surface is treated with an amino-based silane coupling agent. Therefore, the basicity of the amino-based silane coupling agent can suppress the erosion of the battery liquid coating and improve the battery liquid resistance.

  Embodiments of the present invention will be described in detail. The insulated wire according to the present invention has at least a conductor and an insulating layer covering the periphery of the conductor. The insulating layer contains at least a crosslinked silicone rubber and a surface-treated filler. The filler is surface-treated with an amino silane coupling agent.

  An amino-based silane coupling agent is a compound having an amino group and an alkoxysilyl group in the molecule. The amino silane coupling agent has basicity derived from an amino group. Since the filler is surface-treated with a basic silane coupling agent, the basicity blocks the penetration of dilute sulfuric acid in the battery solution into the insulator of the wire coating. The wire coating of the insulated wire is prevented from being eroded by the battery liquid. As a result, the battery liquid resistance of the insulated wire is improved.

  The amino silane coupling agent can be used as long as the aqueous solution has alkalinity, and is not particularly limited. Examples of the amino silane coupling agent include N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane (KBM-602), N-2- (aminoethyl) -3-aminopropyltrimethoxysilane ( KBM-603), 3-aminopropyltrimethoxysilane (KBM-903), 3-aminopropyltrimeethoxysilane (KBE-903), 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine (KBE-9103), N-phenyl-3-aminopropyltrimethoxysilane (KBM-573), and the like. The names in parentheses above are trade names of Shin-Etsu Chemical Co., Ltd.

  The amino silane coupling agent is preferably at least one of 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane. Since the silane coupling agent has a relatively small molecular weight among amino silane coupling agents, it has an advantage of good coating properties.

  Although it does not specifically limit as said filler, From the point of the dispersibility improvement with respect to silicone rubber, it is preferable that it is at least 1 sort (s) of calcium carbonate and barium sulfate. The filler may be either surface-treated or untreated that has not been surface-treated.

  The average particle size of the filler is preferably 1 μm or less, more preferably in the range of 0.01 to 0.8 μm. If the average particle size of the filler exceeds 1 μm, the dispersibility may be deteriorated.

  Examples of the calcium carbonate include trade names of Shiroishi Calcium Co., Ltd., white gloss flower CC (0.05 μm), white gloss flower CCR (0.08 μm), white gloss flower O (0.03 μm), white gloss flower DD (0.05 μm), and Vigot 10 (0 0.1 μm), Vigot 15 (0.15 μm), and white luster AA (0.05 μm). The inside of the parenthesis is the average particle size (the same applies hereinafter).

  Examples of the barium sulfate include trade names of Sakai Chemical Co., Ltd., barium sulfate 100 (0.5 μm), barium sulfate BM-110 (0.5 μm), barium sulfate BF-20 (0.03 μm), barium sulfate 300 ( 0.7 μm).

  Examples of fillers other than the above calcium carbonate and barium sulfate include crown clay (0.6 μm), kaolin clay (1.3 μm), and trade name UD-653 (3 μm) of Ube Materials as magnesium hydroxide. It is done.

  The surface treatment method using a silane coupling agent for the filler is not particularly limited. As the surface treatment method, for example, a filler having a predetermined particle diameter may be surface-treated, or may be treated simultaneously during synthesis. The surface treatment method may be a wet treatment using a solvent or a dry treatment without using a solvent. In the wet treatment, suitable solvents include water, alcohols such as methanol and ethanol, aliphatic solvents such as pentane, hexane and heptane, and aromatic solvents such as benzene, toluene and xylene. Moreover, when preparing the composition of an insulating layer, you may knead | mix a surface treating agent simultaneously with silicone rubber.

  As a treatment method of the filler with a silane coupling agent, for example, a surface treatment can be performed by adding a silane coupling agent and a filler to water and stirring by heating.

  The surface treatment amount of the silane coupling agent relative to the filler is preferably in the range of 0.1 to 5 mass% of the total amount of the silane coupling agent and the filler. The surface treatment amount is the amount of the silane coupling agent added during the surface treatment. If the surface treatment amount of the silane coupling agent is less than 0.1% by mass, the battery liquid resistance may be insufficient, and if it exceeds 5% by mass, the fillers may aggregate.

  The content of the filler surface-treated with the amino-based silane coupling agent in the insulating layer is preferably in the range of 0.1 to 100 parts by mass, more preferably 0.1 to 100 parts by mass of the crosslinked silicone rubber. It is in the range of 5 to 95 parts by mass. If the filler content is less than 0.1 parts by mass, the battery liquid resistance may be insufficient, and if it exceeds 100 parts by mass, the wire appearance may be poor.

  The uncrosslinked silicone rubber may be either a millable type (heat cross-linked type) that becomes an elastic body by kneading a cross-linking agent and then cross-linking by heating, or a liquid rubber type that is liquid before cross-linking. The liquid rubber type silicone rubber includes a room temperature crosslinking type (RTV) capable of crosslinking near room temperature and a low temperature crosslinking type (LTV) capable of crosslinking when heated near 100 ° C. after mixing.

  As the millable silicone rubber, a commercially available rubber compound containing a linear organopolysiloxane as a main raw material (raw rubber) and a dispersion accelerator and other additives may be used.

  In the rubber composition for the insulating layer, the uncrosslinked silicone rubber can be crosslinked by heating or the like, but may be crosslinked by adding a crosslinking agent (vulcanizing agent) to the composition.

  The crosslinking agent can be appropriately selected depending on the type of uncrosslinked rubber, the crosslinking conditions, and the like. Examples of the crosslinking agent include radical generators such as organic peroxides, compounds such as metal soaps, amines, thiols, thiocarbamates, and organic carboxylic acids. As the crosslinking agent, an organic peroxide or the like is preferable 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.

  The amount of the crosslinking agent can be determined as appropriate. It is preferable to mix | blend the compounding quantity of a crosslinking agent in 0.01-10 mass% with respect to the total amount of uncrosslinked rubber | gum and a crosslinking agent, for example.

  The insulating layer may contain various additives in addition to the crosslinked silicone rubber and filler 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. Specifically, a flame retardant, a crosslinking agent, a filler, an antioxidant, an anti-aging agent, a pigment, and the like can be given.

  The insulated wire according to the present invention can be manufactured, for example, as follows. First, a rubber composition for an insulating layer for forming an insulating layer is prepared. Next, the prepared rubber composition is extruded around the conductor to form a coating layer containing uncrosslinked rubber around the conductor. Next, the uncrosslinked rubber of the coating layer is crosslinked by crosslinking means such as heating. Thereby, the insulated wire by which the circumference | surroundings of the conductor were coat | covered with the insulating layer containing crosslinked rubber can be manufactured.

  The insulated wire according to the present invention may also be formed by coating a rubber composition for an insulating layer around a conductor to form a coating layer, and crosslinking the uncrosslinked rubber of the coating layer by a crosslinking means such as heating. Can be manufactured.

  The rubber composition for the insulating layer can be prepared by kneading uncrosslinked silicone rubber, a filler, and various additives such as a crosslinking agent blended as necessary.

  When kneading the components of the rubber composition, for example, it can be uniformly dispersed using a conventional kneader such as a Banbury mixer, a pressure kneader, a kneading extruder, a biaxial kneading extruder, or a roll.

  For extrusion molding of the rubber composition for the insulating layer, an electric wire extrusion molding machine or the like used for production of a normal insulated wire can be used.

  The conductor of an insulated wire can utilize what is used for a normal insulated wire. 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.

  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. For example, although the insulated wire of the said aspect was comprised from the single-layer insulation layer, you may comprise the insulated wire of this invention from multiple layers of an insulating layer or 2 layers or more.

  The insulated wire according to 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 requiring high heat resistance and battery liquid resistance. For example, in an insulated wire for automobiles, such high heat resistance and battery liquid resistance are required for applications such as a power cable for 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.
A rubber composition for an insulating layer containing an uncrosslinked silicone rubber, a filler, and a crosslinking agent in the composition shown in Table 1 (Examples 1 to 7) and Table 2 (Comparative Examples 1 to 7) using a Banbury mixer. Mixed at room temperature. Then, using an extruder, the rubber composition for the insulating layer was extruded and coated to a thickness of 0.2 mm on the outer periphery of a conductor (cross-sectional area 0.5 mm ² ) of an annealed copper twisted wire obtained by twisting seven annealed copper wires. A coating layer containing uncrosslinked rubber was formed. Next, the uncrosslinked rubber was crosslinked by performing a heat treatment of the coating layer at 200 ° C. for 4 hours. Thereby, the insulated wire of the Example and the comparative example was obtained.

  The insulated wires of Examples 1 to 7 and Comparative Examples 1 to 7 were evaluated by performing a cold resistance test, an abrasion resistance test, and a battery liquid resistance test. The results are shown in Tables 1 and 2. In addition, the detail of each component of Table 1 and Table 2, the test method, and evaluation are as follows.

[Silico Rubber]
Silicone rubber 1: Product name “931” (composition: dimethylsiloxane) manufactured by Shin-Etsu Chemical Co., Ltd.
・ Silicone rubber 2: manufactured by Shin-Etsu Chemical Co., Ltd., trade name “541” (composition: dimethylsiloxane)
Silicone rubber 3: manufactured by Toshiba Corporation, trade name “2267” (composition: dimethylsiloxane)
Silicone rubber 4: manufactured by Toshiba Corporation, trade name “2277” (composition: dimethylsiloxane)

[Fillers used in Examples]
・ White glossy DD (KBM-602: 2% treatment)
Calcium carbonate: trade name “Shiraka Hana DD” manufactured by Shiraishi Calcium Co., Ltd.
Silane coupling agent: N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “KBM-602”)
Surface treatment amount of silane coupling agent: 2% by mass of the total amount of calcium carbonate and silane coupling agent
・ Barium sulfate 300 (KBM-903: 3% treatment)
Barium sulfate: trade name “barium sulfate 300” manufactured by Sakai Chemical Industry Co., Ltd., average particle size 0.7 μm
Silane coupling agent: 3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “KBM-903”)
Surface treatment amount of silane coupling agent: 3% by mass of the total amount of barium sulfate and silane coupling agent

[Fillers used in comparative examples]
A filler not treated with an amino silane coupling agent was used.
・ Crown clay (particle size 0.6μm)
Product name "Crown Clay", manufactured by Shiraishi Calcium Co., Ltd., average particle size 0.6μm
・ Barium sulfate 300 (particle size 0.7μm)
Made by Sakai Chemical Industry Co., Ltd., trade name “Barium sulfate 300”, average particle size 0.7 μm

[Crosslinking agent]
・ Crosslinking agent (Perhexyl D)
Di-t-hexyl peroxide (Nippon Yushi Co., Ltd., trade name "Perhexyl D")

[Cold resistance test method]
The cold resistance test 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.

[Abrasion resistance test method]
The abrasion resistance test was performed by a blade reciprocation method in accordance with the automobile technical standard “JASO D618”. That is, the insulated wire of an Example and a comparative example was cut out to 750 mm length, and it was set as the test piece. Then, the blade is reciprocated at a speed of 50 times per minute with a length of 10 mm or more in the axial direction with respect to the coating material (insulating layer) of the test piece at room temperature of 23 ± 5 ° C. until the blade contacts the conductor. The number of round trips was measured. At this time, the load applied to the blade was 7N. About the number of times, the thing of 200 times or more was made into the pass "(circle)", and the thing less than 200 times was made into the disqualified "x". In addition, “◎” is particularly excellent when the number of times is 300 times or more.

[Battery liquid resistance test method]
The battery liquid resistance test was performed in accordance with Method 2 of ISO 6722 (2011 edition). That is, a 25% aqueous sulfuric acid solution having a density of 1.28 is dropped on an electric wire and put into a 90 ° C. constant temperature bath, and after 8 hours, 16 hours and 32 hours, the sulfuric acid aqueous solution is dropped again and put into the constant temperature bath. Repeatedly, it was removed after 48 hours. Then, after being immersed in 3% salt water for 10 minutes, a withstand voltage test of 1 kV × 1 minute was performed. As a result of the withstand voltage test, those that did not break down were rated as “good”, and those that were broken down were rated as “bad”.

  As shown in Table 2, Comparative Examples 1 to 7 had poor battery liquid resistance, but the insulated wires of Examples 1 to 7 had good battery liquid resistance as shown in Table 1, The cold resistance and wear resistance were also good.

  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 (6)

In an insulated wire whose conductor is covered with an insulating layer containing a crosslinked silicone rubber,
The insulated wire, wherein the insulating layer contains a filler surface-treated with an amino silane coupling agent.   The insulated wire according to claim 1, wherein the amino-based silane coupling agent is at least one of 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane.   The surface treatment amount with respect to the filler of the said amino-type silane coupling agent exists in the range of 0.1-5 mass% of the total amount of a silane coupling agent and a filler, The Claim 1 or 2 characterized by the above-mentioned. Insulated wire.   The insulated wire according to any one of claims 1 to 3, wherein the filler is at least one of calcium carbonate and barium sulfate.   The insulated wire according to any one of claims 1 to 4, wherein a content of the filler is in a range of 0.1 to 100 parts by mass with respect to 100 parts by mass of the crosslinked silicone rubber.   The insulated wire according to any one of claims 1 to 5, wherein an average particle size of the filler is 1 µm or less.