JP2007018842A - Insulated electric wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insulated electric wire capable of improving weather resistance without reducing insulation resistance. <P>SOLUTION: The insulated wire comprises a conductor 2 and an insulator 3 covering the conductor 2. A water-repellent layer 4 is formed by coating a silicone on the insulator 3. The insulator 3 is composed of a polyvinyl chloride resin as a main material. A hydrophobized silica of 0.1 to 10 pts.wt. is blended in the polyvinyl chloride resin of 100 pts.wt. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an insulated wire, and more particularly, to an insulated wire having improved weather resistance without reducing insulation resistance.

  Insulated wires such as outdoor polyvinyl chloride insulated wires used outdoors are subject to deterioration phenomena such as hardening over time and becoming brittle when exposed to sunlight or rainwater for many years. This deterioration over time is a phenomenon in which the insulator of the insulated wire is mainly deteriorated. One reason for this is, for example, that polyvinyl chloride resin, which is the main material of the insulator, is subjected to polychlorination by ultraviolet rays in direct sunlight. It is said that the main chain of the vinyl resin is cleaved, resulting in a decrease in molecular weight and insolubilization due to a crosslinking reaction. And the compatibility with the plasticizer mix | blended with this resin falls in the polyvinyl chloride resin which the insolubilization by the reduction | decrease of molecular weight and crosslinking reaction produced. The plasticizer blended in the polyvinyl chloride resin easily escapes from the polyvinyl chloride resin when moisture such as rainwater adhering to the insulator permeates into the resin. The polyvinyl chloride resin from which the plasticizer has escaped becomes hard and gradually loses its flexibility and deteriorates over time. Therefore, conventionally, in order to prevent the polyvinyl chloride resin from being deteriorated by ultraviolet irradiation, carbon black is added to the polyvinyl chloride resin, and the polyvinyl chloride insulated wire for outdoor use in which the color of the wire is given black. Is used.

  However, for polyvinyl chloride insulated electric wires for outdoor use, electric wires with colors such as gray, green, and blue other than black are also used to identify the electric wires. This outdoor polyvinyl chloride insulated wire with a color other than black tends to deteriorate over time as compared to the outdoor polyvinyl chloride insulated wire with black color, that is, it is inferior in weather resistance.

Then, the outdoor polyvinyl chloride insulated wire provided with colors other than black has been improved in weather resistance by adding an ultraviolet absorber. As such a thing, what mixed ultraviolet absorbers, such as a chloro benzotriazole, with a coloring agent, such as an azo pigment, in polyolefin resin (for example, refer patent document 1).
JP 2001-93351 A (pages 2 to 3)

  However, since the insulated wire using the plastic blend for electric wires according to the invention described in Patent Document 1 cannot improve the weather resistance even if a small amount of ultraviolet absorber is added, a large amount of ultraviolet absorber is added. Has been. The plastic blend for electric wires to which a large amount of the ultraviolet absorber is added may cause a decrease in the insulation properties of the insulated wires. Therefore, even if the weather resistance can be improved, it is preferably used as an insulator for the insulated wires. Have the problem of not.

  The objective of this invention is providing the insulated wire which can aim at the improvement of a weather resistance, without reducing an insulation resistance.

  The insulated wire according to claim 1, wherein a water repellent layer made of a water repellent agent is formed on the insulator of the insulated wire formed by covering the conductor and the conductor with the insulator. The main feature is that the main component is vinyl chloride resin, and 0.1 to 10 parts by weight of hydrophobized silica is blended with 100 parts by weight of the polyvinyl chloride resin. With this configuration, an insulated wire in which a water-repellent layer is formed on an insulator containing hydrophobicized silica can be obtained. Insulated wires with a water-repellent layer can form rain and moisture attached to the surface of the water-repellent layer in the form of water droplets and shed from the surface of the water-repellent layer, making it difficult for moisture to penetrate inside the insulator. Become.

  Here, the blending amount of silica is 0.1 to 10 parts by weight with respect to 100 parts by weight of the polyvinyl chloride resin. When the blending amount is less than 0.1 parts by weight, the effect of hydrophobizing silica is obtained. It is because it cannot be demonstrated. On the other hand, when the compounding amount exceeds 10 parts by weight, the flexibility of the insulator is impaired because the compounding amount of silica is large. In addition, the water repellent preferably has a water repellent that has a small surface tension compared to the surface tension of water and a large difference.

  The insulated wire according to claim 2 is characterized in that the water repellent according to claim 1 is composed of one or more of silicone, liquid paraffin, and fluorinated oil. With this configuration, a water repellent layer composed of one or more of silicone, liquid paraffin, and fluorine oil is formed on the insulator. Here, the surface tension of silicone, liquid paraffin, and fluorinated oil is small compared to the surface tension of water, and the difference is large. For this reason, since the water-repellent action of silicone, liquid paraffin, and fluorinated oil is large, the water adhering to the insulator is easily repelled.

  According to the first aspect of the present invention, since the water repellent layer is formed on the insulator blended with the hydrophobized silica, the insulator can maintain the water repellency effect for a long period of time. Therefore, the weather resistance can be improved without lowering the insulation resistance.

  According to the invention described in claim 2, a water repellent layer made of a water repellent having a large effect of repelling water adhering to the insulator is formed on the insulator blended with hydrophobized silica. Therefore, the insulator can maintain the water repellency effect for a long time. Therefore, according to the present invention, it is possible to improve the weather resistance without reducing the insulation resistance.

  The present invention provides a conductor and a water-repellent layer coated with water-repellent silicone on an insulator of an insulated wire formed by coating an insulator on the conductor, and the insulator is a polyvinyl chloride resin. This is realized by a constitution in which 0.1 to 10 parts by weight of hydrophobized silica is blended with 100 parts by weight of the polyvinyl chloride resin.

  Hereinafter, the Example of the insulated wire which concerns on this invention is described in detail based on FIG.

  FIG. 1 shows a cross-sectional view of an outdoor polyvinyl chloride insulated wire as an insulated wire according to an embodiment of the present invention.

  In FIG. 1, reference numeral 1 denotes an outdoor polyvinyl chloride insulated wire. An outdoor polyvinyl chloride insulated wire 1 is composed of a conductor 2 made of annealed copper wire and an insulator 3 coated on the conductor 2. A polyvinyl chloride resin is used as the main material of the insulator 3, and various additives described later are blended in the polyvinyl chloride resin as necessary. A water repellent layer 4 is formed on the surface of the insulator 3 by applying a water repellent such as silicone, liquid paraffin, or fluorine oil. Here, the water-repellent layer 4 is formed on the insulator 3 because the rain and moisture adhering to the surface of the water-repellent layer 4 are formed in the form of water droplets and repelled from the surface of the water-repellent layer 4. This is to prevent moisture from penetrating into the interior and improve weather resistance.

  The insulator 3 of the outdoor polyvinyl chloride insulated wire 1 configured as described above includes a main material polyvinyl chloride resin, a plasticizer, a stabilizer, a filler, a flame retardant, a flame retardant aid, a crosslinking agent, and a crosslinking agent. Various additives such as auxiliaries are blended as necessary, and silica hydrophobized by surface treatment is blended. In addition to having a water repellent effect, this hydrophobized silica has an effect that it can be used without impairing the color for identification as compared with titanium oxide or carbon black. The hydrophobizing treatment of silica is performed by a known method such as a silane coupling agent or a titanate coupling agent. For example, the method using a silane coupling agent is performed by the following procedure.

  First, a silane coupling agent (for example, trade name: KBM-603, manufactured by Shin-Etsu Chemical Co., Ltd.) is adjusted to a concentration of 1% aqueous solution and stored in a predetermined container. Then, a predetermined amount of silica (for example, powder having an average particle size of 0.1 to 10 μm) is put into this container and mixed with a 1% aqueous solution. Next, the 1% aqueous solution mixed with the silica is stirred by a mixer to uniformly disperse the silica in the liquid. Then, when left in this state for one day, silica is hydrophobized by the silane coupling agent. Finally, in order to recover the hydrophobized silica from the container, a 1% aqueous solution mixed with silica is filtered, and the filtered silica is dehydrated and dried.

  The reason why the silica surface is hydrophobized by the silane coupling agent in this manner is that the silane coupling agent forms a siloxane (Si—O—Si) bond on the silica surface. Note that the siloxane bond refers to a structure having a structure in which silicon (Si) and oxygen (O) are alternately arranged, and a hydrocarbon or the like is bonded to silicon.

  And this hydrophobized silica is mix | blended 0.1-10 weight part with respect to 100 weight part of polyvinyl chloride resin which is the main material of the insulator 3. FIG. Here, the blending amount of silica was set to 0.1 to 10 parts by weight with respect to 100 parts by weight of the polyvinyl chloride resin. This is because the interaction with the water repellent constituting the water repellent layer 4 is not sufficient. On the other hand, when the blending amount exceeds 10 parts by weight, even if the interaction between the hydrophobized silica and the water repellent agent of the water-repellent layer 4 is sufficient, the blending amount of silica is large, so This is because flexibility and the like are impaired.

  Thus, a predetermined amount of the hydrophobized silica is blended in the polyvinyl chloride resin which is the main material of the insulator 3. This polyvinyl chloride resin is blended with required amounts of various additives such as plasticizers, stabilizers, fillers, flame retardants, flame retardant aids, cross-linking agents, and cross-linking aids, as well as hydrophobized silica. And melt-kneading (for example, 200 ° C.). Thereafter, the polyvinyl chloride resin in which necessary amounts of various additives are blended is extruded together with the conductor 2 by a known extruder, and the outdoor polyvinyl chloride insulated wire 1 is formed by this extrusion. In addition, although the silica used for the present Example is hydrophobized by the method of the silane coupling agent, it is not necessarily limited to the method of the silane coupling agent, and is a known hydrophobizing treatment. Can be used without any problem.

  By the way, in this outdoor polyvinyl chloride insulated wire 1, a water repellent is further applied on the insulator 3 to form a water repellent layer 4. As this water repellent, one having a large water repellent effect is preferable. Specifically, the surface tension is smaller than that of water and the difference from the surface tension of water is large, and silicone, liquid paraffin, fluorine oil, and the like are suitable. Among these, silicone is preferable when comprehensively evaluating water repellency, handleability, price, and the like. This silicone is composed of a siloxane (Si—O—Si) bond and a hydrocarbon group, and is excellent in heat resistance, lubricity, water repellency and the like.

  Silicone includes straight silicone such as dimethyl silicone, methylphenyl silicone, and methylhydrosilicone, and modified silicone such as epoxy-modified silicone, amino-modified silicone, carboxyl-modified silicone, and alkyl-modified silicone. In the water-repellent layer 4 of this embodiment, oil-like or emulsion-like straight silicone adjusted to an appropriate viscosity (for example, trade name: KF96 manufactured by Shin-Etsu Chemical Co., Ltd.) is applied on the insulator 3. Is formed. Here, the viscosity of the silicone applied to the outdoor polyvinyl chloride insulated wire 1 is adjusted to a range of 10 to 1000 cSt (25 ° C.) in consideration of the workability of the application. For the application of silicone, a suitable method corresponding to this viscosity is suitably used from the viewpoint of workability, and a known application method such as a brush, a roller or a spray is preferably used. Further, the thickness of the water repellent layer 4 is not particularly limited, but may be any as long as the water repellency can be maintained for a long period of time. For example, a thickness of 0.05 to 1 mm is preferable.

  Silicone forming the water repellent layer 4 is less likely to be peeled off from the insulator due to the interaction with the hydrophobic silica blended in the polyvinyl chloride resin of the insulator 3. Therefore, the water repellent layer 4 formed on the insulator 3 is held on the insulator 3 for a long time, and the water repellent effect of the insulator 3 can be maintained for a long time. If the water-repellent effect is maintained for a long period of time, the penetration of moisture adhering to the surface of the insulator 3 into the insulator 3 is prevented for a long period of time, so that the plasticizer blended in the polyvinyl chloride resin of the insulator 3 And the like are retained in the polyvinyl chloride resin for a long time. Therefore, even if the required amount of plasticizer is maintained for a long period of time, even if it is chemically deteriorated by ultraviolet rays, the mechanical properties of the polyvinyl chloride resin, for example, the deterioration of flexibility is prevented for a long period of time. The weather resistance can be improved as compared with a polyvinyl chloride resin in which the required amount of plasticizer is not maintained for a long time.

The insulator 3 and the water repellent layer 4 configured as described above are specifically shown as examples in Tables 1 and 2. Based on Tables 1 and 2, the insulator 3 and the water repellent layer 4 will be described in detail.

  Table 1 shows the composition of the insulator 3 of the insulated wire 1 shown in Examples 1 to 3, the presence or absence of the water-repellent layer 4, and the results of the evaluation of the properties of the insulator 3. Table 2 shows the composition of the insulators of the insulated wires shown in Comparative Examples 1 to 5, the presence / absence of the water-repellent layer, and the results of the physical property evaluation of the insulators. The physical properties are evaluated for weather resistance, tensile elongation characteristics, and insulation resistance described later.

  The insulators of Examples 1 to 3 and Comparative Examples 1 to 4 shown in Table 1 are composed of the compositions shown below.

[Example 1]
In the insulator of Example 1, a general-purpose polyvinyl chloride resin (PVC) is used as a main material, and hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., trade name: AEROSIL R972) is 0.1 per 100 parts by weight of this PVC. Parts by weight, plasticizer DOP (dioctyl phthalate) (manufactured by J-Plus Co., Ltd.) 50 parts by weight, stabilizer Ca-Zn (Asahi Denka Kogyo Co., Ltd., trade name: RUP-103) 5 parts by weight, The filler is composed of 40 parts by weight of calcium carbonate (trade name: VIGOT-10, manufactured by Shiraishi Calcium Co., Ltd.). On this insulator, silicone (manufactured by Shin-Etsu Silicone Co., Ltd., trade name: KF96) is applied with a brush to form a water repellent layer. This insulator does not contain an ultraviolet absorber.

[Example 2]
The insulator of Example 2 uses a general-purpose polyvinyl chloride resin (PVC) as a main material, and 5 parts by weight of hydrophobized silica (manufactured by Nippon Aerosil Co., Ltd., trade name: AEROSIL R972) with respect to 100 parts by weight of this PVC. 50 parts by weight of plasticizer DOP (dioctyl phthalate) (manufactured by J-Plus Co., Ltd.), 5 parts by weight of stabilizer Ca—Zn (manufactured by Asahi Denka Kogyo Co., Ltd., trade name: RUP-103), filler And 40 parts by weight of calcium carbonate (trade name: VIGOT-10, manufactured by Shiraishi Calcium Co., Ltd.). On this insulator, silicone (manufactured by Shin-Etsu Silicone Co., Ltd., trade name: KF96) is applied with a brush to form a water repellent layer. This insulator does not contain an ultraviolet absorber.

Example 3
In the insulator of Example 3, general-purpose polyvinyl chloride resin (PVC) is used as a main material, and 10 parts by weight of hydrophobized silica (manufactured by Nippon Aerosil Co., Ltd., trade name: AEROSIL R972) with respect to 100 parts by weight of PVC. 50 parts by weight of plasticizer DOP (dioctyl phthalate) (manufactured by J-Plus Co., Ltd.), 5 parts by weight of stabilizer Ca—Zn (manufactured by Asahi Denka Kogyo Co., Ltd., trade name: RUP-103), filler And 40 parts by weight of calcium carbonate (trade name: VIGOT-10, manufactured by Shiraishi Calcium Co., Ltd.). On this insulator, silicone (manufactured by Shin-Etsu Silicone Co., Ltd., trade name: KF96) is applied with a brush to form a water repellent layer. This insulator does not contain an ultraviolet absorber.

[Comparative Example 1]
The insulator of Comparative Example 1 uses a general-purpose polyvinyl chloride resin (PVC) as a main material, and 50 parts by weight of plasticizer DOP (dioctyl phthalate) (manufactured by J-Plus Co., Ltd.) with respect to 100 parts by weight of this PVC. , 5 parts by weight of the stabilizer Ca-Zn (Asahi Denka Kogyo Co., Ltd., trade name: RUP-103) and 40 parts by weight of calcium carbonate (Shiraishi Calcium Co., Ltd., trade name: VIGOT-10) as the filler Formulated and configured. On this insulator, silicone (manufactured by Shin-Etsu Silicone Co., Ltd., trade name: KF96) is applied with a brush to form a water repellent layer. This insulator does not contain hydrophobized silica and an ultraviolet absorber.

[Comparative Example 2]
The insulator of Comparative Example 2 uses a general-purpose polyvinyl chloride resin (PVC) as a main material, and 10 parts by weight of hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., trade name: AEROSIL R972) with respect to 100 parts by weight of PVC. , 50 parts by weight of plasticizer DOP (dioctyl phthalate) (manufactured by J-Plus), 5 parts by weight of stabilizer Ca—Zn (manufactured by Asahi Denka Kogyo Co., Ltd., trade name: RUP-103), filler And 40 parts by weight of calcium carbonate (product name: VIGOT-10, manufactured by Shiraishi Calcium Co., Ltd.). In addition, since silicone is not apply | coated on this insulator, the water repellent layer is not formed. Further, this insulator does not contain an ultraviolet absorber.

[Comparative Example 3]
The insulator of Comparative Example 3 uses a general-purpose polyvinyl chloride resin (PVC) as a main material, and 20 parts by weight of hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., trade name: AEROSIL R972) with respect to 100 parts by weight of PVC. , 50 parts by weight of plasticizer DOP (dioctyl phthalate) (manufactured by J-Plus Co., Ltd.), 5 parts by weight of stabilizer (manufactured by Asahi Denka Kogyo Co., Ltd., trade name: RUP-103), and calcium carbonate ( The product is composed of 40 parts by weight of Shiroishi Calcium Co., Ltd., trade name: VIGOT-10). On this insulator, silicone (trade name: KF96, manufactured by Shin-Etsu Silicone Co., Ltd.) is applied to form a water repellent layer. Note that no ultraviolet absorber is added to this insulator.

[Comparative Example 4]
The insulator of the insulated wire of Comparative Example 4 uses a general-purpose polyvinyl chloride resin (PVC) as a main material, and an ultraviolet absorber (Asahi Denka Kogyo Co., Ltd., trade name: ADK STAB 1413) with respect to 100 parts by weight of PVC. 1 part by weight of Adeka Stub LA51 mixed 1: 1), 50 parts by weight of plasticizer DOP (dioctyl phthalate) (manufactured by J-Plus Co., Ltd.), stabilizer Ca-Zn (Asahi Denka Kogyo Co., Ltd.) Manufactured, trade name: RUP-103) and 40 parts by weight of calcium carbonate (trade name: VIGOT-10) manufactured by Shiraishi Calcium Co., Ltd. as a filler. In addition, since silicone is not apply | coated on this insulator, the water repellent layer is not formed. Further, this insulator does not contain hydrophobized silica.

[Comparative Example 5]
The insulator of the insulated wire of Comparative Example 5 is made of general-purpose polyvinyl chloride resin (PVC) as a main material, and plasticizer DOP (dioctyl phthalate) (manufactured by J-Plus Co., Ltd.) with respect to 100 parts by weight of this PVC. 50 parts by weight, 5 parts by weight of stabilizer (Asahi Denka Kogyo Co., Ltd., trade name: RUP-103), 40 parts by weight of calcium carbonate (Shiraishi Calcium Co., Ltd., trade name: VIGOT-10) as a filler And configured. In addition, since silicone is not apply | coated on this insulator, the water repellent layer is not formed. Further, this insulator does not contain hydrophobized silica and an ultraviolet absorber.

  Insulators of Examples 1 to 3 and Comparative Examples 1 to 5 having such a composition are kneaded and extruded by a known extruder, and formed as an insulator of an insulated wire.

  Next, the evaluation contents and the results of the weather resistance, tensile elongation characteristics, and insulation resistance of the insulator having such a composition will be described.

〔Weatherability〕
The evaluation of the weather resistance of the insulator in this example is to evaluate the degree of deterioration because the insulator deteriorates when exposed to sunlight (ultraviolet rays) or rain for a long time. ) Sunshine weather meter in accordance with JIS B 7753 is used as an accelerated test method. This sunshine weather meter uses a sunshine carbon arc as a light source, a size of 150 × 70 mm and a maximum thickness of 15 mm as a test piece, and the sample surface irradiance of this test piece is 255 W / m ² (± 10%). , Adjust the black panel temperature in the testing machine to 63 ± 3 ° C and the relative humidity of the air in the testing machine to 50 ±% RH, and set the watering time to 18 minutes / 120 minutes (1 cycle) and repeat continuously For a predetermined time. In this example, this test time is 3000 hours. Incidentally, under the above conditions, when the test time is 1000 hours, it corresponds to 10 years of exposure time in the outdoor exposure test.

  In addition, a test piece extrudes the insulator composition comprised based on the composition of Example 1- Example 3 and Comparative Example 1- Comparative Example 5 with a well-known extruder, and becomes a sheet | seat of 1-2 mm in thickness. After being produced and left at room temperature for 24 hours or more after being extruded, it is produced in a predetermined shape. For the insulators of Examples 1 to 3, Comparative Example 1, and Comparative Example 3, a method in which silicone was preliminarily adjusted to have a substantially uniform thickness, for example, 0.5 mm, on the surface of the test piece. Apply with (brush).

  Here, the evaluation of the weather resistance of the insulator is based on whether the color tone of the surface of the test piece can be identified by visually observing the appearance of the test piece removed from the sunshine weather meter after 3000 hours of the test time, This is done by discriminating discrimination. In this evaluation, “◎” indicates that discrimination is good, “◯” indicates that discrimination is possible, “Δ” indicates that discrimination is somewhat difficult, and “×” indicates that discrimination is difficult. And the result evaluated based on such a content is shown by Table 1 and Table 2, and this evaluation result is demonstrated in detail below.

  First, it was Example 1, Example 2, Example 3, and Comparative Example 4 that were evaluated as “◎” in the weather resistance evaluation. This is because the insulator of Example 1 is blended with 0.1 parts by weight of silica (based on 100 parts by weight of PVC), and silicone is applied on the insulator, thereby preventing deterioration due to water for a long period of time. As a result, it was evaluated as “性” because of its good discrimination. Further, the insulator of Example 2 was blended with 5 parts by weight of silica (based on 100 parts by weight of PVC), and silicone was applied on the insulator, so that deterioration due to water was prevented for a long period of time. Therefore, it was evaluated as “◎” because of its good discrimination. Further, the insulator of Example 3 was blended with 5 parts by weight of silica (based on 100 parts by weight of PVC), and silicone was applied on the insulator, so that deterioration due to water was prevented for a long time. Therefore, it was evaluated as “◎” because of its good discrimination.

  The insulator of Comparative Example 4 is different from the insulators of Examples 1 to 3 in that the silica is not blended in the insulator and the silicone is not applied on the insulator. However, since the insulator of Comparative Example 4 is blended with 1 part by weight of the ultraviolet absorber (based on 100 parts by weight of PVC) in the insulator, deterioration due to ultraviolet rays can be prevented for a long period of time, so that the distinguishability is good. Therefore, it was evaluated as “◎”. In addition, according to the evaluation result of the insulation resistance mentioned later, since the ultraviolet absorber is mix | blended with the insulator of the comparative example 4, the insulation resistance is inferior.

  Next, in Comparative Example 1 and Comparative Example 3, the evaluation of the weather resistance was “◯”. In Comparative Example 1, since silicone is applied on an insulator, deterioration due to water can be prevented by silicone. However, in Comparative Example 1, since silica is not blended in the insulator, the water repellent effect of silicone cannot be maintained in a good state for a long period of time. The weather resistance was evaluated as “◯” because it was not in good condition. In Comparative Example 3, 20 parts by weight of silica (based on 100 parts by weight of PVC) is blended in the insulator, and silicone is applied on the insulator, so that the water repellent effect of silicone is good for a long time. Can be maintained. However, Comparative Example 3 was not in a good state even though it could be recognized that there was discriminability due to the effect that silica was blended in a large amount in the insulator [20 parts by weight (relative to 100 parts by weight of PVC)]. Therefore, the weather resistance was evaluated as “○”.

  In Comparative Example 2, the weather resistance was evaluated as “Δ”. In Comparative Example 2, 10 parts by weight of silica (based on 100 parts by weight of PVC) is blended in the insulator, but no silicone is applied on the insulator, so it adheres to the insulator. The water repellent water could not be sufficiently repelled, so the discrimination was somewhat difficult, and the weather resistance was evaluated as “Δ”. Further, Comparative Example 5 was evaluated as “×”. This is because Comparative Example 5 can repel water adhering to the insulator because silica is not blended in the insulator and silicone is not applied on the insulator. Since it was not possible, it was difficult to distinguish, so the weather resistance was evaluated as “x”.

[Tensile elongation characteristics]
The evaluation of the tensile elongation characteristic of the insulator in this example is to measure the elongation of a test piece under a predetermined tensile stress in order to evaluate the flexibility of the insulator, and is JIS of Japanese Industrial Standard (JIS). A tensile test according to C3005 is used. This tensile test is performed according to the following procedure.

  First, as an evaluation test sample, an insulator composition configured based on the compositions of Examples 1 to 3 and Comparative Examples 1 to 5 was extruded with an extruder into a sheet having a thickness of 1 to 2 mm. Produced. The produced sheet is allowed to stand for 24 hours or more after being extruded at room temperature, and then produced into a predetermined shape (JIS No. 3 dumbbell piece).

  The test piece is then correctly and reliably attached at one end to the chuck of the tensile tester so that the test piece does not become distorted or otherwise incurred during the test. And the test piece attached to the testing machine is pulled at a predetermined pulling speed (200 mm / min) and is eventually broken. Based on the broken specimen, the elongation of the specimen is obtained by the following procedure. First, the length between the marked lines is measured before the tensile test. Next, the length between the marked lines of the test piece is measured from the test piece broken in the tensile test, and this measured length is the length between the marked lines measured before the test (original length). And subtract the value after this subtraction by the original length. Then, this divided value is displayed as a percentage, and the value represented by this percentage is evaluated as the elongation of the test piece. That is, the elongation (%) is expressed as a percentage with the maximum elongation when the test piece is stretched as a relative ratio to the original length. In addition, the length between marked lines means the length (distance) between two marked lines attached to the parallel part of the test piece before the test for the purpose of measuring elongation (strain).

  Here, the target value of the elongation of the insulator is “300% or more”. The reason why the elongation target value is set to 300% or more is that an insulator having excellent flexibility cannot be obtained if the elongation is less than 300%. In Table 1, since the sample determined as “◯” has an elongation of 300% or more, when the target value is satisfied, the sample determined as “x” has an elongation of less than 300%. It is shown that it does not meet. And the result evaluated based on such a content is shown by Table 1 and Table 2, and this evaluation result is demonstrated below.

  In Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2, Comparative Example 4, and Comparative Example 5 were evaluated as “◯” in the evaluation of tensile elongation characteristics. In Comparative Example 3, only “x” was given in the tensile elongation evaluation. This is because Example 1 with an evaluation of “◯” is 0.1 parts by weight of silica, 100 parts by weight of polyvinyl chloride resin, Example 2 is 5 parts by weight of silica, Example 3 is 10 parts by weight of silica, Comparative Examples 1, 4 and 5 contain 0 part by weight of silica, and Comparative Example 2 contains 10 parts by weight of silica, so that the flexibility of the insulator is not lost, and the elongation exceeds 300% of the target. It was because it was over. On the other hand, in Comparative Example 3 with an evaluation of “×”, 20 parts by weight of silica is blended with 100 parts by weight of the polyvinyl chloride resin which is the main material of the insulator. This is because the flexibility was lost and the elongation was below the target of 300%.

[Insulation resistance]
The evaluation of the insulation resistance of the insulator in this example is to measure the resistance of the insulator in order to evaluate the insulation of the insulator, and an insulation resistance test based on JIS C3005 of the Japanese Industrial Standard (JIS) is performed. Used. According to this insulation resistance test, the insulation resistance of the insulator is obtained by measuring the resistance of a test piece molded into a predetermined shape with a high insulation resistance meter and evaluating this resistance as the residual ratio of the insulation resistance. . That is, the insulation resistance of the insulator is divided by the insulation resistance of the insulator (referenced to Comparative Example 5 in this embodiment) based on the resistance measured by the high insulation resistance meter. The percentage of insulation resistance is expressed as a percentage, and the percentage of insulation resistance is evaluated. This residual ratio of insulation resistance is an evaluation of how much insulation is present compared to the reference insulator, and the greater the residual ratio of insulation resistance, the greater the insulation.

  The reason why Comparative Example 5 was used as a reference is that the insulator of Comparative Example 5 is preferable as a so-called blank material for testing because silica and an ultraviolet absorber are not blended. Moreover, the test piece extrude | pushed out with the well-known extruder the insulator composition comprised based on the composition of Example 1- Example 3 and Comparative Example 1- Comparative Example 5 to the sheet | seat of 1-2 mm in thickness. After being produced and allowed to stand for 24 hours or more after extrusion at room temperature, it is produced in the shape of a predetermined test piece as a test sample for evaluation.

  Here, in this embodiment, the target value of the remaining ratio of the insulation resistance is “90% or more”. The reason why the target value of the residual ratio of insulation resistance is set to 90% or more is that if the residual ratio of insulation resistance is less than 90%, an insulator having excellent insulating properties cannot be obtained. In Tables 1 and 2, the sample determined as “◯” has a remaining ratio of insulation resistance of 90% or more. Therefore, if the target value is satisfied, the sample determined as “×” indicates the remaining insulation resistance. Since the rate is below 60%, it is shown that the target value is not satisfied. Although not shown in Tables 1 and 2, the middle of the evaluations “◯” and “×”, that is, the evaluation is “△”, is that the insulation resistance remaining rate is less than 90% and 60% or more. Is the body. The insulator evaluated as “Δ” includes a certain degree of insulation, but it is not always recognized that the insulation is excellent.

  The results evaluated according to the criteria thus provided are shown in Tables 1 and 2, and the evaluation results will be described below.

  In Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 5 were evaluated as “◯” in the evaluation of the insulation resistance. And it is only the comparative example 4 that evaluation was made "x". This is because the example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 5 with an evaluation of “◯” do not contain an ultraviolet absorber, so that the insulation resistance This is because the residual ratio of insulation resistance exceeded 90% of the target. On the other hand, in Comparative Example 4 where the evaluation is “x”, the insulation resistance is lowered and the residual ratio of insulation resistance is less than 60% because a large amount of the ultraviolet absorber is blended in the insulator.

  As described above, according to the insulated wire according to the present example, an appropriate amount of the hydrophobized silica is blended with the polyvinyl chloride resin constituting the insulator, and a water-repellent silicone layer is formed on the polyvinyl chloride resin. Therefore, the weather resistance can be improved.

  Moreover, since the insulated wire which concerns on a present Example mix | blends the silica which hydrophobized in the polyvinyl chloride resin which comprises an insulator, a suitable quantity can be obtained with an improvement in a weather resistance.

  Moreover, since the ultraviolet absorber is not mix | blended with the polyvinyl chloride resin which comprises the insulator, the insulated wire which concerns on a present Example can improve a weather resistance, without reducing an insulation resistance.

Sectional drawing of the outdoor polyvinyl chloride insulated wire which concerns on the Example of this invention.

Explanation of symbols

1 …………… Outdoor PVC insulated wire 2 …………… Conductor 3 …………… Insulator 4 …………… Water repellent layer

Claims (2)

Forming a water repellent layer made of a water repellent on the conductor and the insulator of the insulated wire formed by covering the conductor with an insulator;
The insulated wire is characterized in that a polyvinyl chloride resin is a main material, and 0.1 to 10 parts by weight of hydrophobized silica is blended with 100 parts by weight of the polyvinyl chloride resin.   2. The insulated wire according to claim 1, wherein the water repellent is composed of one or more of silicone, liquid paraffin, and fluorine oil.

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