JP2016134268A - Insulated wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insulated wire improved in heat resistance.SOLUTION: An insulated wire (1) includes: an insulation coating layer (3) which contains a vinyl chloride resin, a modified resin having a glass transition point of 100°C or higher, and a plasticizer; and a conductor (2) covered with the insulation coating layer. In the insulation coating layer, the content of the plasticizer is 25-50 pts.mass based on 100 pts.mass of the total of the vinyl chloride resin and the modified resin. In the insulation coating layer, the content ratio of the vinyl chloride resin to the modified resin is 90:10-70:30 (vinyl chloride resin:modified resin) by mass.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an insulated wire. In detail, this invention relates to the insulated wire which improved heat resistance.

  High heat resistance is required for insulated wires used in high-temperature environments such as automobile engine rooms. For this reason, a cross-linked polyethylene is mainly used as a covering material for insulated wires used in such a place. The main reason for using cross-linked polyethylene as the coating material is that its heat aging characteristics are excellent, and that heat resistance can be increased by a cross-linking treatment.

  However, since the heat resistance cannot be increased unless the cross-linked polyethylene is subjected to a cross-linking treatment, the load exerted on the environment in terms of production is large. For this reason, it has been studied to use a vinyl chloride resin as a covering material that does not need to be subjected to a crosslinking treatment and is inexpensive and easy to process.

  For example, in Patent Document 1, (A) a plasticizer containing trimellitic acid plasticizer and / or pyromellitic acid plasticizer in polyvinyl chloride, (B) chlorinated polyolefin, (C) methyl methacrylate-butadiene- A wire coating material containing styrene is disclosed. And it describes that such a wire coating material improves cold resistance, abrasion resistance, and trauma resistance. Patent Document 2 discloses an electric wire covering material containing polyvinyl chloride, a plasticizer, chlorinated polyethylene, and an MBS resin. It is described that such a wire covering material can be inserted into a terminal without buckling and has improved flexibility.

JP 2011-126980 A JP 2012-252869 A

  However, the electric wires of Patent Documents 1 and 2 have insufficient heat resistance, and when used in a high temperature environment, there is a fear that sufficient electrical insulation cannot be ensured.

  The present invention has been made in view of the problems of such conventional techniques. And the objective of this invention is providing the insulated wire which improved heat resistance.

  The insulated wire according to the first aspect of the present invention includes an insulating coating layer containing a vinyl chloride resin, a modified resin having a glass transition point of 100 ° C. or higher, and a plasticizer, and a conductor coated with the insulating coating layer. Is provided. And in an insulation coating layer, content of a plasticizer with respect to a total of 100 mass parts of a vinyl chloride resin and modified resin is 25-50 mass parts, and the content ratio of a vinyl chloride resin and modified resin is 90: by mass ratio. 10-70: 30 (vinyl chloride resin: modified resin).

  The insulated wire according to the second aspect of the present invention relates to the insulated wire of the first aspect, and the modified resin includes a maleimide resin.

  In the insulated wire of the present invention, the insulating coating layer contains a predetermined amount of each of a vinyl chloride resin, a modified resin having a glass transition point of 100 ° C. or higher, and a plasticizer. Therefore, high heat resistance can be secured for a long period of time, and good electrical insulation can be obtained even when used in a high temperature environment.

It is sectional drawing which shows the insulated wire which concerns on embodiment of this invention.

  Hereinafter, the insulated wire concerning the embodiment of the present invention is explained in detail using a drawing. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio.

  As shown in FIG. 1, the insulated wire 1 according to the present embodiment includes a conductor 2 and an insulating coating layer 3 that covers the periphery of the conductor 2.

  As the conductor 2, a single wire constituted by one strand may be used, or a stranded wire constituted by twisting a plurality of strands may be used. A stranded wire is also a concentric stranded wire in which one or several strands are centered and the strands are concentrically twisted around it; a collective stranded wire in which a plurality of strands are twisted together in the same direction; Any of composite stranded wires obtained by twisting a plurality of aggregate strands concentrically can be used.

  The diameter of the conductor 2 and the diameter of each strand constituting the conductor 2 are not particularly limited. Furthermore, the material of the conductor 2 is not particularly limited, and a known conductive metal material such as copper, copper alloy, aluminum, and aluminum alloy can be used. The surface of the conductor 2 may be plated, for example, tin plating, silver plating, or nickel plating.

  The insulating coating layer 3 covering the outer periphery of the conductor 2 is formed of a resin composition that can ensure electrical insulation with respect to the conductor 2. Specifically, the insulating coating layer 3 contains a vinyl chloride resin and a plasticizer. Furthermore, in this embodiment, in order to improve the heat resistance of the insulation coating layer 3, the modified resin whose glass transition point is 100 degreeC or more is contained. By mixing such a modified resin together with a vinyl chloride resin and a plasticizer, the heat resistance of the insulating coating layer is improved over a long period of time, and electrical insulation is ensured even in a high temperature environment such as an engine room of an automobile. It becomes possible.

  Examples of the vinyl chloride resin used for the insulating coating layer 3 include polyvinyl chloride, chlorinated polyvinyl chloride, polyvinylidene chloride, chlorinated polyethylene, vinyl chloride-vinyl acetate copolymer, vinyl chloride-ethylene copolymer, Vinyl chloride-propylene copolymer, vinyl chloride-styrene copolymer, vinyl chloride-isobutylene copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-styrene-maleic anhydride copolymer, vinyl chloride-styrene- Acrylonitrile copolymer, vinyl chloride-butadiene copolymer, vinyl chloride-isoprene copolymer, vinyl chloride-chlorinated propylene copolymer, vinyl chloride-vinylidene chloride-vinyl acetate copolymer, vinyl chloride-maleic acid ester copolymer Polymer, vinyl chloride-methacrylate copolymer, vinyl chloride-acrylic Nitrile copolymer, vinyl chloride - may be mentioned various vinyl ether copolymers. These vinyl chloride resins may be used individually by 1 type, and may be used in combination of 2 or more type. The polymerization method of the vinyl chloride resin is not particularly limited, such as bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization.

  The average degree of polymerization (weight average degree of polymerization) of the vinyl chloride resin is not particularly limited, but is preferably 500 to 5000, and more preferably 1500 to 3000. When the average degree of polymerization is 500 or more, a decrease in heat resistance of the insulating coating layer 3 to be obtained can be suppressed. Moreover, when the average degree of polymerization is 5000 or less, an increase in melt viscosity at the time of extrusion molding can be suppressed, and further deterioration of molding processability can be prevented. In addition, in the insulating coating layer 3 of this embodiment, you may use the vinyl chloride resin which exists in the range of the said polymerization degree 1 type or in combination of 2 or more types.

  The plasticizer used for the insulating coating layer 3 is not particularly limited as long as it penetrates between the molecules of the vinyl chloride resin, weakens the intermolecular force of the resin, and gives the vinyl chloride resin flexibility. However, in this embodiment, it is preferable that a plasticizer contains 1 type, or 2 or more types selected from a trimellitic acid type plasticizer and a pyromellitic acid type plasticizer. The trimellitic acid plasticizer and pyromellitic acid plasticizer are excellent in heat resistance and weather resistance, and are low in volatility, and thus are suitable for the insulating coating layer 3 that requires long-term heat resistance.

  Examples of trimellitic acid plasticizers include trimellitic acid esters. Examples of pyromellitic acid plasticizers include pyromellitic acid esters. In the trimellitic acid ester and pyromellitic acid ester, examples of the alcohol constituting the ester by dehydration condensation include saturated aliphatic alcohols having 8 to 13 carbon atoms. These alcohols can be used singly or in combination of two or more.

  The plasticizer used for the insulating coating layer 3 may contain a plasticizer other than the trimellitic acid plasticizer and the pyromellitic acid plasticizer. Examples of other plasticizers include phthalic acid plasticizers and aliphatic plasticizers. If the blending amount of the entire plasticizer is within a specific range described later and the blending amounts of trimellitic acid-based plasticizer and pyromellitic acid-based plasticizer are within a specific range, the insulating coating layer 3 is flexible. Heat resistance can be improved. In addition, it is preferable that the plasticizer used for the insulating coating layer 3 is mainly composed of at least one of trimellitic acid plasticizer and pyromellitic acid plasticizer. That is, in the plasticizer used for the insulating coating layer 3, the total content of trimellitic acid plasticizer and pyromellitic acid plasticizer is preferably 50% by mass or more, and preferably 70% by mass or more. More preferably, it is particularly preferably 95% by mass or more.

  Examples of the phthalic acid plasticizer include phthalic acid esters. In the phthalate ester, examples of the alcohol constituting the ester by dehydration condensation include saturated aliphatic alcohols having 8 to 13 carbon atoms. Moreover, these alcohol can be used 1 type or in combination of 2 or more types. More specifically, the phthalic acid plasticizer is, for example, from the group consisting of di-2-ethylhexyl phthalate, di-n-octyl phthalate, diisononyl phthalate, dinonyl phthalate, diisodecyl phthalate and ditridecyl phthalate. There may be mentioned at least one selected.

  Examples of the aliphatic plasticizer include at least one selected from the group consisting of adipic acid esters, sebacic acid esters, and azelaic acid esters. In these esters, examples of the alcohol constituting the ester by dehydration condensation include saturated aliphatic alcohols having 3 to 13 carbon atoms. Moreover, these alcohol can be used 1 type or in combination of 2 or more types. More specifically, examples of the aliphatic plasticizer include at least one selected from the group consisting of dioctyl adipate, isononyl adipate, dibutyl sebacate, dioctyl sebacate, and dioctyl azelate.

  As described above, in order to ensure long-term heat resistance and electrical insulation under high temperature conditions, the insulating coating layer 3 of the insulated wire 1 contains a modified resin. As such a modified resin, it is preferable to use a resin having at least one of a glass transition point (Tg) and a flow start point (flow start temperature) higher than that of the vinyl chloride resin. Specifically, the modified resin is preferably a resin having a glass transition point (Tg) of 100 ° C. or higher. When the glass transition point of the modified resin is less than 100 ° C., the glass transition point is preferably 100 ° C. or higher because the heat resistance is poor even when the addition amount is increased.

  Since the processing temperature of the material increases as the glass transition point of the modified resin increases, dehydrochlorination of the vinyl chloride resin proceeds due to the influence of heat during processing, and the long-term heat resistance of the resulting insulating coating layer 3 increases. There is a possibility of lowering. Therefore, the modified resin is preferably a resin having a glass transition point of 100 ° C to 160 ° C. However, it is also possible to use a resin having a glass transition point exceeding 160 ° C. as the modified resin by adjusting the processing method so that dehydrochlorination of the vinyl chloride resin does not proceed easily.

  Further, as the modified resin, a resin having a flow starting point of 100 ° C. or higher is also preferable. When the flow starting point of the modified resin is less than 100 ° C., it is difficult to improve the heat resistance of the insulating coating layer 3, and therefore the flow starting point is preferably 100 ° C. or higher.

  The modified resin preferably contains a maleimide resin. By using a maleimide resin as the modifying resin, it becomes possible to easily polymerize with a vinyl chloride resin and improve the wear resistance at high temperatures. In particular, the modified resin is more preferably a maleimide resin.

  The maleimide resin is preferably a maleimide copolymer. The maleimide copolymer is preferably a copolymer of N-phenylmaleimide and another monomer. In addition, as another monomer copolymerized with N-phenylmaleimide, at least 1 type chosen from the group which consists of methyl methacrylate, styrene, and acrylonitrile can be mentioned. In particular, when the modified resin is a copolymer of N-phenylmaleimide, methyl methacrylate, and styrene, the heat resistance can be further improved because of high compatibility with the vinyl chloride resin. The maleimide copolymer preferably contains 50% by mass or more of N-phenylmaleimide as a main component.

  In addition, in the insulation coating layer 3, it is preferable that content of the plasticizer with respect to a total of 100 mass parts of a vinyl chloride resin and a modified resin is 25-50 mass parts. When the content of the plasticizer is less than 25 parts by mass, the flexibility is lowered and the durability at low temperature may be insufficient. In addition, when the plasticizer content exceeds 50 parts by mass, the flexibility is increased and the workability is improved, but even if a modified resin is added, the wear resistance at high temperatures may be insufficient. There is.

  In the insulating coating layer 3, the content ratio of the vinyl chloride resin and the modified resin is preferably 90:10 to 70:30 (vinyl chloride resin: modified resin) in mass ratio. When the content ratio of the modified resin is less than 10, the hardness of the insulating coating layer 3 decreases, and the wear resistance at high temperatures may be insufficient. In addition, when the content ratio of the modified resin exceeds 30, the hardness of the insulating coating layer 3 is increased, so that the durability at low temperatures is lowered, and the handling of the obtained insulated wire 1 may be difficult. is there. In addition, when the plasticizer has the above-described content, if the content ratio of the modified resin exceeds 30, the long-term heat resistance may be slightly lowered. Therefore, the content ratio of the modified resin is also in the above range from this viewpoint. It is preferable.

  Insulating coating layer 3 of this embodiment can contain various additives in addition to the above materials. Additives include stabilizers, pigments, antioxidants, extenders, metal deactivators, anti-aging agents, lubricants, fillers, reinforcing agents, UV absorbers, dyes, colorants, antistatic agents, foaming agents, etc. Is mentioned.

  Next, the manufacturing method of the insulated wire 1 of this embodiment is demonstrated. The insulation coating layer 3 of the insulated wire 1 is prepared by heating and kneading the above-mentioned materials, and a known means can be used for the method. For example, the resin composition constituting the insulating coating layer 3 is obtained by kneading the above-described materials using a known kneader such as a Banbury mixer, a pressure kneader, a kneading extruder, a twin screw extruder, or a roll mill. Can do. Alternatively, the above materials may be dry blended in advance using a tumbler or the like and then kneaded using the above kneader. In addition, after heat-kneading, it takes out from a kneader and obtains a resin composition. At that time, the resin composition may be formed into pellets with a pelletizer or the like.

  And in the manufacturing method of the insulated wire 1, a well-known means can also be used for the method of coat | covering the conductor 2 with the insulation coating layer 3. FIG. For example, the insulating coating layer 3 can be formed by a general extrusion method. And as an extruder used by an extrusion molding method, a single screw extruder or a twin screw extruder is used, for example, and what has a screw, a breaker plate, a crosshead, a distributor, a nipple, and a die can be used.

  As a specific method for manufacturing the insulated wire 1, first, the vinyl chloride resin and the modified resin are put into a twin screw extruder set to a temperature at which the vinyl chloride resin and the modified resin are sufficiently melted. At this time, a plasticizer and, if necessary, the above-described additives are also added. The vinyl chloride resin, the modified resin, and the like are melted and kneaded by a screw, and a certain amount is supplied to the cross head via the breaker plate. The melted vinyl chloride resin, the modified resin, and the like flow into the circumference of the nipple by a distributor and are extruded while being coated on the outer circumference of the conductor by a die. Thereby, the insulation coating layer 3 which coat | covers the outer periphery of the conductor 2 can be obtained.

  The insulated wire 1 of this embodiment includes an insulating coating layer 3 containing a vinyl chloride resin, a modified resin having a glass transition point of 100 ° C. or higher, and a plasticizer, and a conductor 2 covered with the insulating coating layer 3. Prepare. And in the insulation coating layer 3, content of the plasticizer with respect to a total of 100 mass parts of a vinyl chloride resin and modified resin is 25-50 mass parts, and the content ratio of a vinyl chloride resin and modified resin is 90 by mass ratio. : 10 to 70:30 (vinyl chloride resin: modified resin). Since the insulating coating layer 3 in the present embodiment can ensure high heat resistance for a long period of time, it is possible to obtain good electrical insulation even when used in a high temperature environment. Moreover, since the plasticizer is contained in a predetermined amount and the flexibility of the insulating coating layer is increased, not only long-term heat resistance but also durability at low temperatures is improved. Furthermore, when the content ratio of the vinyl chloride resin and the modified resin is within the above range, it is possible to improve not only long-term heat resistance but also wear resistance and handleability.

  In the insulated wire 1 of the present embodiment, the modified resin preferably contains a maleimide resin. By using a maleimide resin as the modifying resin, it is possible to improve compatibility with the vinyl chloride resin and improve the wear resistance at high temperatures.

  The insulated wire 1 of the present embodiment has the insulating coating layer 3 formed of a resin composition having good heat resistance, and therefore can be disposed in the vicinity of an internal combustion engine, a motor, a converter, or the like as a high-temperature part. is there. As a result, the insulated wire 1 can be suitably used for a vehicle such as an electric vehicle. And it is preferable to use such an insulated wire 1 for the wire harness for motor vehicles by which high heat resistance, intensity | strength, electroconductivity, etc. are requested | required.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited to these Examples.

  First, by using a kneader, the following vinyl chloride resins, modified resins, plasticizers, fillers, stabilizers and processing aids were melt-kneaded in the blending amounts shown in Tables 1 to 3, and each Example and The resin composition of the comparative example was prepared.

(Vinyl chloride resin)
Polyvinyl chloride Shin-Etsu Chemical Co., Ltd. product name: TH2000 (degree of polymerization 2000), product name TH3000 (degree of polymerization 3000)
(Modified resin)
Maleimide Copolymer Made by Nippon Shokubai Co., Ltd. Product name: Polyimilex (registered trademark) PML-203 (Glass transition point: 140 ° C., main monomers: N-phenylmaleimide, methyl methacrylate and styrene)
(Plasticizer)
-Trimellitic acid plasticizer Product name: ADEKA Sizer (registered trademark) C-N9 (trimellitic acid isononyl ester)
・ Pyromellitic acid plasticizer Made by ADEKA Co., Ltd. Product name: Adekasizer (registered trademark) UL-100 (Pyromellitic acid mixed linear alkyl ester)
(Filler)
Product name: Calmos (registered trademark)
(Stabilizer)
Ca / Zn-based stabilizer for polyvinyl chloride, manufactured by ADEKA Corporation Product name: ADK STAB (registered trademark) RUP-110
(Processing aid)
Acrylic processing aids made by Mitsubishi Rayon Co., Ltd. Trade name: Metablen (registered trademark) P-551

Next, a copper core wire having a cross-sectional area of 1.8 mm ² was prepared as a metal conductor. Then, the metal conductor was subjected to extrusion molding under a temperature condition of about 210 ° C. using an extrusion coating apparatus for manufacturing an electric wire, and an electric wire test sample coated with the resin composition of each example and comparative example was produced. In addition, it adjusted so that the thickness of the insulation coating layer after a coating might be set to 0.4 mm in the case of extrusion molding.

[Evaluation]
About the electric wire test sample of the said Example and comparative example, long-term heat resistance, high temperature abrasion property, and low temperature evaluation were implemented with the following method. Each evaluation result is shown according to Tables 1 to 3.

<Long-term heat resistance>
First, the copper core wire was removed from the wire test samples obtained in Examples and Comparative Examples, and only the insulating coating layer was heated at 160 ° C. for a predetermined time. Next, the elongation percentage of the insulating coating layer after heating was measured to determine whether or not the elongation percentage was 100% or more. This operation was repeated to determine the heating time when the elongation was less than 100%. When the elongation of the insulating coating layer is less than 100%, the heating time is evaluated as “◯” for 280 hours or more, “△” is evaluated for 240 hours or more and less than 280 hours, and “×” is less than 240 hours. It was evaluated. In addition, the elongation rate of the insulating coating layer was measured at 200 mm / min by a strograph.

<High temperature wear resistance>
The wire test sample of each example obtained above was subjected to a wear test in accordance with the scrape wear standard of IS06722 using a wire having a diameter of 0.45 mm as a wearer. In this test, the wearer was repeatedly slid on the insulating coating layer with a 5N load applied to the wearer in an environment of 100 ° C. And the case where it did not conduct between a metal conductor and a wire even if the number of times of scraping was 10 times or more was evaluated as “◯”, and the case where it was conducted when the number of scrapes was less than 10 was evaluated as “x”.

<Low temperature>
First, the wire test samples obtained in the examples and comparative examples were cooled in air at -40 ° C for 4 hours or more. Next, the cooled wire test sample was spirally wound around a metal mandrel having the same diameter as that of the wire test sample. After that, as a result of applying a withstand voltage at 1 kV for 1 minute between the metal conductor of the wound wire test sample and the metal mandrel, the dielectric breakdown did not occur. Things were rated as “x”.

  From Table 1, it can be seen that the wire test samples of Examples 1 to 10 according to the present embodiment are excellent in long-term heat resistance. That is, if long-term heat resistance is "(circle)" and "(triangle | delta)", it can use suitably as an electric wire for vehicles. Moreover, it turns out that the electric wire test sample of an Example is excellent in the abrasion property at the time of high temperature, and durability at the time of low temperature in addition to long-term heat resistance.

  On the other hand, Comparative Examples 1 and 6 to 8 in which the modified resin is insufficient or not contained are found to have insufficient wear resistance at high temperatures. Moreover, it turns out that durability at the time of low temperature becomes inadequate in the comparative examples 2 and 3 with excess modifying resin. And it turns out that the comparative example 4 with excess plasticizer has insufficient wear resistance at high temperature, and the comparative example 5 with insufficient plasticizer has insufficient durability at low temperature.

  Although the present invention has been described with reference to the examples and comparative examples, the present invention is not limited to these, and various modifications can be made within the scope of the gist of the present invention.

1 Insulated wire 2 Conductor 3 Insulation coating layer

Claims (2)

An insulating coating layer containing a vinyl chloride resin, a modified resin having a glass transition point of 100 ° C. or higher, and a plasticizer;
A conductor coated with the insulating coating layer;
With
In the insulating coating layer, the content of the plasticizer is 25 to 50 parts by mass with respect to a total of 100 parts by mass of the vinyl chloride resin and the modified resin, and the content ratio of the vinyl chloride resin and the modified resin is a mass ratio. 90:10 to 70:30 (vinyl chloride resin: modified resin). The insulated wire according to claim 1, wherein the modified resin includes a maleimide resin.

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