JP2007134116A - Insulation composition, insulation material, insulated wire and cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insulation composition containing polylactate and having desired flexibility, to provide an insulation material, and to provide an insulated wire and cable. <P>SOLUTION: The insulated wire 10 comprises a conductor 11, and a cover material 12 covering the conductor 11. The covering material 12 is formed of this insulation composition containing polylactate and an ethylene-ethyl acrylate copolymer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an insulating composition, an insulating material, an insulated wire, and a cable.

In recent years, it has been studied to use an insulating material made of an insulating composition containing polylactic acid as a covering material for insulated wires (see Patent Document 1). Polylactic acid is a thermoplastic resin obtained by chemically polymerizing lactic acid produced by fermenting starch or sugars obtained from plants such as corn or sugar beet, and is environmentally friendly and has excellent insulating properties.
JP 2002-358829 A

  However, conventional insulating compositions containing polylactic acid are relatively brittle and lack flexibility. For this reason, an insulated wire using an insulating material made of such an insulating composition as a covering material, for example, when it is bent with a relatively large curvature (that is, a small radius) as seen in low-voltage wiring. There is a possibility that a crack will be generated in the wire and the insulation withstand voltage of the wire will be lowered.

  The present invention has been made to address such conventional problems. Therefore, an object of the present invention is to provide an insulating composition, an insulating material, an insulated wire, and a cable that contain polylactic acid and have desired flexibility.

  In order to solve the above-mentioned problems, an insulating composition according to the present invention includes polylactic acid and an ethylene-ethyl acrylate copolymer resin.

  The insulating material according to the present invention includes the insulating composition.

  The insulated wire according to the present invention comprises a conductor and a covering material that covers the conductor, and the covering material comprises the insulating material.

  The cable according to the present invention includes a conductor and a covering material that covers the conductor, and the covering material includes the insulating material.

  ADVANTAGE OF THE INVENTION According to this invention, the insulating composition and insulating material which have flexibility are provided, and the insulated wire and cable excellent in the bending characteristic are provided.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

  First, referring to FIG. 1 to FIG. 3, the insulating composition 3 (FIG. 3), the insulating material 5 (FIG. 3), the insulated wire 10 (FIG. 1 to FIG. 3), and the cable 20 ( 2 and 3) will be described. FIG. 1 is a cross-sectional view of an insulated wire 10 extruded by using the insulating composition 3 as a covering material 12, and FIG. 2 is a cross-sectional view of a cable 20 extruded by using the insulating composition 3 as a covering material. FIG. 3 is a manufacturing process diagram.

  The insulated wire 10 is composed of a good electrical conductor 11 made of copper and a covering material 12 made of an insulating composition that covers and insulates the conductor 11. The covering material 12 is formed by extruding an insulating material 5 containing polylactic acid (PLA) 1, ethylene-ethyl acrylate copolymer resin (EEA) 2, and an additive 4 for electric wires onto a conductor 11, and showing a joint line indicated by a virtual line It is commercialized in a state 13 that is seamlessly molded so that 12a is eliminated.

  The cable 20 includes insulated wires 10, 10, 10 arranged in parallel and a substantially flat covering material 22 that covers and insulates these insulated wires 10, 10, 10 in common. The covering material 22 also extrudes insulating material 5 including PLA (polylactic acid) 1, EEA (ethylene-ethyl acrylate copolymer resin) 2, and wire additive 4 above and below the insulated wires 10, 10, 10, The product is made into a state 23 that is seamlessly molded so that the joint line 22a indicated by the phantom line is eliminated.

  Next, the manufacturing method of the insulated wire 10 and the cable 20 will be described.

  This manufacturing method includes a preparation step 30 for preparing the insulating material 5 for electric wires and a processing step 40 for extruding the prepared insulating material 5 as a covering material.

  The preparation step 30 includes a step of kneading 31 PLA 1 and EEA 2 to obtain the insulating composition 3. When obtaining the insulating material 5, the wire additive 4 (for example, a flame retardant) is added and kneading 31 is performed.

  In the processing step 40, the insulated wire 10 is manufactured by extruding 41 the insulating material 5 on the conductor 11 as the covering material 12. Further, the cable 20 is manufactured by extruding the insulating material 5 onto the insulated wire 10.

  Insulating composition 3 includes PLA1 and EEA2, and PLA1 has insulating properties, has good biodegradability, and EEA2 provides flexibility. Therefore, the insulating composition 3 is environmentally friendly and flexible. Function as.

  Since the insulating material 5 is composed of the insulating composition 3 and the wire additive 4, it functions as an environment-friendly and flexible insulating material.

  Since the covering materials 12 and 22 are formed of the insulating material 5, the insulated wire 10 and the cable 20 function as environment-friendly and flexible insulated wires and cables.

  EEA2 contains an ethyl acrylate (EA) amount of 28 wt% or more, MFR at 190 ° C. and 2.16 kg is 25 g / 10 min or more, and preferably 20 parts by mass or more with respect to 100 parts by mass of PLA. . Here, MFR indicates melt mass flow rate. If the EEA is increased from 100 parts by mass, the characteristics of the EEA become stronger and the meaning of applying the PLA is weakened. Therefore, the EEA is preferably made 100 parts by mass with respect to 100 parts by mass of the PLA.

  Experimental Examples 1 to 4 were performed as preferred examples of the above embodiment, Experimental Examples 5 to 7 were performed as experiments for knowing the blending conditions, and Experimental Example 8 was further performed for comparison.

1. Sample Preparation Each sample was tried to add flexibility to PLA by kneading PLA and flexible EEA. The PLA used was Mitsui Chemicals Lacia H400, and EEA was A-703, -704, -707, -709 manufactured by Mitsui DuPont Polychemical Co., Ltd.

Experimental example 1
100 parts by mass of PLA and 100 parts by mass of A-709 were kneaded. A-709 contains 34 wt% EA, and MFR is 25 g / 10 min. In Example 1 as a whole, the total EEA was 100 parts by mass, the average EA content in EEA was 34 wt%, and the average MFR of EEA was 25 g / 10 min.

Experimental example 2
100 parts by mass of PLA and 20 parts by mass of A-709 were kneaded. In the entire experimental example 2, the total EEA is 20 parts by mass, the average EA content in the EEA is 34 wt%, and the average MFR of EEA is 25 g / 10 min.

Experimental example 3
100 parts by mass of PLA, 13 parts by mass of A-709, and 7 parts by mass of A-707 were kneaded. A-707 contains 17 wt% EA and MFR is 25 g / 10 min. In Example 3 as a whole, the total EEA was 20 parts by mass, the average EA content in EEA was 28 wt%, and the average MFR of EEA was 25 g / 10 min.

Experimental Example 4
100 parts by mass of PLA, 8 parts by mass of A-704, and 12 parts by mass of A-703 were kneaded. A-703 contains 25 wt% EA, and MFR is 5 g / 10 min. In the whole Experimental Example 4, the total EEA is 20 parts by mass, the average EA content in the EEA is 25 wt%, and the average MFR of EEA is 25 g / 10 min.

Experimental Example 5
100 parts by mass of PLA and 20 parts by mass of A-707 were kneaded. In Example 5 as a whole, the total EEA was 20 parts by mass, the average EA content in EEA was 17 wt%, and the average MFR of EEA was 25 g / 10 min.

Experimental Example 6
100 parts by mass of PLA and 15 parts by mass of A-709 were kneaded. In Example 6 as a whole, the total EEA was 15 parts by mass, the average EA content in EEA was 34 wt%, and the average MFR of EEA was 25 g / 10 min.

Experimental Example 7
100 parts by mass of PLA and 20 parts by mass of A-703 were kneaded. In the entire experimental example 7, the total EEA is 20 parts by mass, the average EA content in the EEA is 25 wt%, and the average MFR of EEA is 5 g / 10 min.

Experimental Example 8
Experimental Example 8 was obtained by adding 100 parts by mass of PLA to which EEA was not added.

  Here, MFR was measured at 190 ° C. and 2.16 kg based on the plastic-thermoplastic melt mass flow rate (MFR) and melt volume flow rate (MVR) test methods described in JIS K 7210.

  Samples obtained in each experimental example were evaluated by a sheet U-shaped bending test and a bending withstand voltage test.

2. Sheet U-shaped Bending Test FIG. 4 is an explanatory diagram of the sheet U-shaped bending test. As shown in the figure, the insulating material 5 obtained in each experimental example is used as a sample, and this sample is pressed to produce a sheet, which is formed into a strip-shaped sheet 50 having a length of 100 mm, a width of 10 mm, and a thickness of 1 mm. Disconnected. This strip-like sheet 50 was wound around a 20 mmφ metal cylinder 51, and the surface of the bent portion 50a was observed.

3. Bending withstand voltage test First, an insulated wire having a conductor diameter of 1.6 mm and a covering material thickness, that is, an insulation thickness of 0.8 mm was used as a sample, and this sample was n times the diameter (n = 3, 10, 20). The sample wire 63 was wound around a metal tube having an outer diameter of 3 turns, and the surface thereof was observed.

  Next, the wound sample wire 63 was removed from the metal tube, and the withstand voltage test shown in FIG. 5 was performed in accordance with 4.6 of the JIS C3005 rubber / plastic insulated wire test method (underwater voltage withstand voltage). In the withstand voltage test, water 62 is placed in a container 60, the water 62 is kept at the potential of the ground 61 a by the ground circuit 61, the bent portion 63 a of the sample electric wire 63 is immersed in the water 62, and is applied to both ends of the conductor of the sample electric wire 63. A voltage circuit 65 was connected, a predetermined test voltage was applied from the AC voltage 64, and the withstand voltage of the covering material interposed between the conductor and water was measured.

4). Test Results FIG. 6 shows the results of the sheet U-shaped bending test and the bending withstand voltage test.

  As a result of the sheet U-shaped bending test, in Experimental Examples 1 to 4, the bent portion 50a of the strip-shaped sheet 50 was not whitened or cracked, and no change was observed. In contrast, in Experimental Example 8 in which the coating material was formed of PLA alone, a minute crack occurred in the bent portion 50a. In Experimental Example 5, the average MFR of EEA is 25 g / 10 min, and although 20 parts by mass of EEA is blended with 100 parts by mass of PLA, the average EA content in EEA is as low as 17 wt%, so that the bent part 50a is whitened. did. In Experimental Example 6, the average MFR of EEA is 25 g / 10 min, and the average EA content in EEA is 34 wt%. However, since EEA is blended at a ratio of 15 parts by mass with respect to 100 parts by mass of PLA, bending The part 50a was whitened. In Experimental Example 7, 20 parts by mass of EEA is blended with 100 parts by mass of PLA, and the average EA content in EEA is 25 wt%, but the average MFR of EEA is as low as 5 g / 10 min, so there are very small cracks in the bent part 50a. There has occurred. Thus, by mixing PLA and EEA, cracks occurring in the bent portion 50a can be prevented, but when the amount of EEA, the amount of EA, and the MFR are low, whitening or cracks are generated in the bent portion 50a. I understood.

  As a result of the bending withstand voltage test, dielectric breakdown did not occur within the specified time in any of the samples under the test conditions of DC 50 kV 10 min and AC 10 kV 10 min in 20-fold diameter bending. In addition, in 10 times diameter bending, no dielectric breakdown occurred within the specified time in any sample under the test conditions of AC 10 kV 10 min. On the other hand, in the triple diameter bending which bends with a large curvature, under the test conditions of AC 10 kV 10 min, dielectric breakdown did not occur within the specified time in Experimental Examples 1 to 4, but within the specified time in Experimental Examples 5 to 8. Dielectric breakdown occurred, or dielectric breakdown occurred before boosting to the specified voltage. In this way, even in the bending withstand voltage test, dielectric breakdown can be prevented by kneading PLA and EEA. However, if the EEA amount, EA amount, and MFR are low, the dielectric breakdown occurs when bending with a large curvature. It turns out that happens.

  Although the embodiment of the present invention has been described above, it should not be understood that the description and the drawings, which constitute a part of the disclosure of the above embodiment, limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

It is sectional drawing of the insulated wire which extrusion-molded using the insulating composition as a coating | covering material. It is sectional drawing of the cable which extrusion-molded the insulating composition as the coating | covering material. FIG. It is explanatory drawing which shows a sheet | seat U-shaped bending test. It is explanatory drawing which shows a bending withstand voltage test. It is a table | surface which shows the result of a sheet | seat U-shaped bending test and a bending withstand voltage test.

Explanation of symbols

1 ... PLA
2 ... EEA
DESCRIPTION OF SYMBOLS 3 ... Insulating composition 4 ... Additive for electric wire 5 ... Insulating material 10 ... Insulated electric wire 11 ... Conductor 12 ... Covering material 20 ... Cable 22 ... Covering material

Claims (5)

  An insulating composition comprising polylactic acid and an ethylene-ethyl acrylate copolymer resin.   The ethylene-ethyl acrylate copolymer resin contains an ethyl acrylate amount of 28 wt% or more, MFR at 190 ° C. and 2.16 kg is 25 g / 10 min or more, and is 20 parts by mass or more with respect to 100 parts by mass of the polylactic acid. The insulating composition according to claim 1, which is blended.   An insulating material comprising the insulating composition according to claim 1.   An insulated wire comprising a conductor and a covering material covering the conductor, wherein the covering material is made of an insulating composition according to claim 1 or 2. A cable comprising a conductor and a covering material covering the conductor, wherein the covering material is formed of the insulating composition according to claim 1 or 2.

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