JP2017139071A - Insulated electric wire and cable, and molded compact - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insulated electric wire which is excellent in adhesion to a mold material while using a fluorine-containing elastomer composition and a cable, and to provide a molded compact using the insulated electric wire and the cable.SOLUTION: There is provided a molded compact 100 which has an insulated electric wire 10 that has a conductor 1 and an insulating layer 2 being the outermost layer formed from a fluorine-containing elastomer composition, and a mold material 4 provided on the outer periphery of the insulated electric wire 10, where the insulating layer 2 has a ratio (C=O/C-C) between a C=O bond and a C-C bond of the surface thereof of 0.5 or more.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an insulated wire, a cable, and a molded body.

  When connecting a device part such as a sensor or an electrode terminal to an electric wire or a cable, the connection part and its periphery are generally covered with a mold resin for protection.

  Equipment parts such as these sensors are used in automobiles, robots, electronic equipment, etc. that require high reliability. Therefore, the airtightness between the molded resin molding and the wires and cables is a very important characteristic. One. For this reason, it is important to use a combination of a molding material and an electric wire / cable coating material that has excellent adhesion (see Patent Documents 1 and 2).

  In such applications, polyamide resin, polyurethane resin and the like are mainly used as the molding material.

  On the other hand, higher heat resistance is required for electric wires and cables. In particular, as electric wires and cables having excellent heat resistance, electric wires coated with a fluorine-containing elastomer composition are used (see Patent Document 3).

JP 2012-28123 A JP 2014-141650 A JP-A-6-76643

  However, since the adhesiveness is poor between the fluorine-containing elastomer composition and the molding material such as polyamide resin or polyurethane resin, it is difficult to ensure the desired airtightness. In particular, in a cross-linked fluorine-containing elastomer composition, the effect of exhibiting adhesiveness due to an anchor effect or the like due to mutual diffusion of materials due to heat at the time of molding cannot be expected, and thus the desired airtightness cannot be obtained.

  As a countermeasure against the above problems, the heat-tight tube has conventionally been installed between the wire / cable and the mold material, but on the other hand, the number of parts increases, so the size of the molded body and the cost are reduced. There was a limit to reducing this.

  Accordingly, an object of the present invention is to provide an insulated wire and a cable excellent in adhesiveness to a molding material and a molded product using the insulated wire and the cable while using the fluorine-containing elastomer composition. .

  In order to achieve the above object, the present invention provides the following insulated wires and cables, and molded products.

[1] An outermost layer made of a fluorine-containing elastomer composition is provided, and the outermost layer has an insulating ratio of surface C═O bond to C—C bond (C═O / C—C) of 0.5 or more. Electrical wire.
[2] The insulated wire according to [1], wherein the fluorine-containing elastomer composition contains a tetrafluoroethylene / propylene copolymer as a base polymer.
[3] The fluorine-containing elastomer composition contains 5 to 60 parts by mass of calcium carbonate as an inorganic filler with respect to 100 parts by mass of the base polymer, and is crosslinked. Insulated wires.
[4] The insulated wire according to any one of [1] to [3], wherein the outermost layer is subjected to an atmospheric pressure plasma treatment.
[5] A molded body comprising the insulated wire according to any one of [1] to [4] and a molding material provided on an outer periphery of the insulated wire.
[6] A cable comprising an outermost layer made of a fluorine-containing elastomer composition, wherein the outermost layer has a surface C = O bond to C—C bond ratio (C═O / C—C) of 0.5 or more. .
[7] The cable according to [6], wherein the fluorine-containing elastomer composition contains a tetrafluoroethylene / propylene copolymer as a base polymer.
[8] The fluorine-containing elastomer composition contains 5 to 60 parts by mass of calcium carbonate as an inorganic filler with respect to 100 parts by mass of the base polymer, and is crosslinked. Cable.
[9] The cable according to any one of [6] to [8], wherein the outermost layer is subjected to an atmospheric pressure plasma treatment.
[10] A molded article comprising the cable according to any one of [6] to [9] and a molding material provided on an outer periphery of the cable.

  ADVANTAGE OF THE INVENTION According to this invention, while using the fluorine-containing elastomer composition, the molded object using the insulated wire and cable excellent in adhesiveness with a molding material and the said insulated wire and cable can be provided.

It is a cross-sectional view which shows an example of the insulated wire which concerns on embodiment of this invention. It is a cross-sectional view showing an example of a cable according to an embodiment of the present invention. It is a cross-sectional view which shows an example (use the insulated wire of FIG. 1) of the molded object which concerns on embodiment of this invention. It is a cross-sectional view which shows another example (use the cable of FIG. 2) of the molded object which concerns on embodiment of this invention. It is a figure which shows the outline of the test apparatus which tests the airtightness between the insulated wire and mold material in the molded object of an Example and a comparative example.

[Insulated wire]
An insulated wire according to an embodiment of the present invention includes an outermost layer made of a fluorine-containing elastomer composition, and the outermost layer has a ratio of a surface C═O bond (hereinafter also referred to as a carbonyl group) to a C—C bond. (C = O / C-C) is 0.5 or more.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view showing an example of an insulated wire according to an embodiment of the present invention.

  An insulated wire 10 according to the embodiment of the present invention shown in FIG. 1 includes a conductor 1 and an insulating layer 2 as an outermost layer made of a fluorine-containing elastomer composition and coated on the outer periphery of the conductor 1.

  Known materials can be used for the conductor 1, and examples thereof include copper, annealed copper, silver, and aluminum. Moreover, tin plating, nickel plating, silver plating, gold plating, etc. may be given to these surfaces. The number of conductors 1 is not limited to one as shown in FIG. 1, and a plurality of strands may be twisted.

  The fluorine-containing elastomer composition constituting the insulating layer 2 as the outermost layer preferably contains a tetrafluoroethylene / propylene copolymer as a base polymer, and further contains an ethylene / tetrafluoroethylene copolymer. Is more preferable. Base polymers other than these may be appropriately contained.

(Tetrafluoroethylene / propylene copolymer)
Tetrafluoroethylene / propylene copolymer has a large modification effect by atmospheric pressure plasma and imparts adhesion to various molding materials. The tetrafluoroethylene / propylene copolymer may be either one containing or not containing a double bond in the polymer main chain. Two or more types of tetrafluoroethylene / propylene copolymers may be used.

  The tetrafluoroethylene / propylene copolymer may be a copolymer obtained by further copolymerizing tetrafluoroethylene and propylene which are main components. Examples include, but are not limited to, isobutylene, acrylic acid, chloroethyl vinyl ether, and the like.

  The tetrafluoroethylene / propylene copolymer used in the present embodiment preferably has a Mooney viscosity at 100 ° C. of 200 ML or less, and more preferably 100 ML or less, from the viewpoint of processability.

(Ethylene / tetrafluoroethylene copolymer)
Although the ethylene-tetrafluoroethylene copolymer has a lower modification effect by atmospheric pressure plasma than the tetrafluoroethylene-propylene copolymer, the tetrafluoroethylene-propylene copolymer such as toughness (tensile strength, etc.) Use as a complement to inferior properties. Two or more kinds of ethylene / tetrafluoroethylene copolymers may be used.

  The ethylene / tetrafluoroethylene copolymer preferably has a melt flow rate (297 ° C., 49 N) of 10 (g / 10 min) or more and a melting point of 240 from the viewpoints of suppression of self-heating during extrusion and suppression of foaming. It is preferable that it is below ℃.

  The ethylene / tetrafluoroethylene copolymer may contain a third component other than ethylene and tetrafluoroethylene as main components. Examples of the third component include, but are not limited to, fluoroolefin.

  The blending mass ratio of the tetrafluoroethylene / propylene copolymer to the ethylene / tetrafluoroethylene copolymer (tetrafluoroethylene / propylene copolymer: ethylene / tetrafluoroethylene copolymer) is preferably 100: 0 to 60: 40, more preferably 95: 5 to 65:35, and still more preferably 90:10 to 70:30. When the amount of the ethylene / tetrafluoroethylene copolymer is too large, the adhesiveness tends to be insufficient, and the target airtightness is hardly obtained.

(Inorganic filler)
The fluorine-containing elastomer composition preferably contains calcium carbonate, talc, silica, clay, hydrotalcite, magnesium hydroxide, aluminum hydroxide, etc. as the inorganic filler, and among them, calcium carbonate and silica are preferable. . Although the detailed cause is unknown, fillers other than calcium carbonate and silica tend to have poor heat resistance.

  As for the particle size of the inorganic filler used in the embodiment of the present invention, the average particle size measured by a laser diffraction particle size distribution measuring device is preferably in the range of 0.1 to 10 μm. When the average particle size is smaller than 0.1 μm, the heat resistance may be insufficient, and when larger than 10 μm, the tensile strength may be insufficient.

  The filling amount of the inorganic filler used in the embodiment of the present invention is preferably 5 parts by mass or more and 60 parts by mass or less, and preferably 10 parts by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the base polymer. Is more preferably 10 parts by mass or more and 30 parts by mass or less. When the amount is less than 5 parts by mass, the appearance during extrusion may be rough. When the amount is more than 60 parts by mass, the heat resistance may be insufficient.

(Other additives)
In addition to the inorganic filler, the fluorine-containing elastomer composition is appropriately cross-linked, cross-linking auxiliary, filler, stabilizer, antioxidant, lubricant, flame retardant, plasticizer within the range of achieving the object of the present invention. An agent or the like may be added.

  In the embodiment of the present invention, the fluorine-containing elastomer composition constituting the insulating layer 2 is preferably crosslinked. As the crosslinking method, electron beam irradiation crosslinking is suitable.

  In the embodiment of the present invention, the insulating layer 2 as the outermost layer has a surface ratio of C═O bonds to C—C bonds (C═O / C—C) of 0.5 or more, preferably 0.8. It is 6 or more, More preferably, it is 0.8 or more, More preferably, it is 1.0 or more.

  As a method for adjusting the ratio of the surface C═O bond to the C—C bond (C═O / C—C) within the above range, for example, there is a method of subjecting the insulating layer 2 to atmospheric pressure plasma treatment. At this time, the blending mass ratio of the tetrafluoroethylene / propylene copolymer and the ethylene / tetrafluoroethylene copolymer is preferably within the above-mentioned range.

  As processing conditions for atmospheric pressure plasma processing, for example, an atmospheric pressure plasma jet apparatus (for example, a commercial apparatus manufactured by Nihon Plasma Treat Co., Ltd.) is used, and the processing speed is 0.1 to 5 m / min from the nozzle hole to the insulated wire. Is carried out as 3 to 7 mm. Nitrogen, dry air, etc. can be applied as the type of gas that generates atmospheric pressure plasma. Further, if the distance from the nozzle hole to the insulated wire exceeds 7 mm, the airtightness may be insufficient.

  Other methods for adjusting the ratio of C═O bond to C—C bond (C═O / C—C) on the surface within the above range include, for example, the above base polymer and maleic acid modified polymer or epoxy modified polymer ( A polymer having a modified functional group having a C═O group), specifically, a blend of the above base polymer with maleic acid-modified ethylene / propylene / diene rubber (EPDM) or ethylene / glycidyl methacrylate (EGMA). Examples thereof include a method used, a method in which acrylic acid or the like is reacted with a polymer side chain and grafted.

  In the present embodiment, the insulating layer 2 may be a single layer, or may have a multilayer structure. Furthermore, you may give a separator, a braiding, etc. as needed.

〔cable〕
A cable according to an embodiment of the present invention includes an outermost layer made of a fluorine-containing elastomer composition, and the outermost layer has a ratio of C═O bond to C—C bond on the surface (C═O / C—C). Is 0.5 or more.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 2 is a cross-sectional view showing an example of a cable according to the embodiment of the present invention.

  The cable 20 according to the embodiment of the present invention shown in FIG. 2 includes a two-core stranded wire obtained by twisting two insulated wires 10 each having a conductor 1 covered with an insulating layer 2 and an outer periphery thereof that is extrusion-coated. And a sheath 3 as an outermost layer made of a fluorine elastomer composition. The insulated wire 10 may be a single core or a multi-core stranded wire other than a two-core. Moreover, although the insulated wire 10 which concerns on embodiment of this invention was used here, you may use another insulated wire.

  The sheath 3 is preferably composed of the aforementioned fluorine-containing elastomer composition.

  In the embodiment of the present invention, the fluorine-containing elastomer composition constituting the sheath 3 is preferably cross-linked. As the crosslinking method, electron beam irradiation crosslinking is suitable.

  In the embodiment of the present invention, the sheath 3 as the outermost layer has a surface C═O bond to C—C bond ratio (C═O / C—C) of 0.5 or more, preferably 0.6. It is above, More preferably, it is 0.8 or more, More preferably, it is 1.0 or more.

  As a method for adjusting the ratio of the surface C═O bond to the C—C bond (C═O / C—C) within the above range, for example, there is a method in which the sheath 3 is subjected to atmospheric pressure plasma treatment. At this time, the blending mass ratio of the tetrafluoroethylene / propylene copolymer and the ethylene / tetrafluoroethylene copolymer is preferably within the above-mentioned range. Other methods include those described above.

  In the present embodiment, the sheath 3 may be composed of a single layer or a multilayer structure. Further, a separator, a braid, a shield tape made of metal foil, or the like may be applied as necessary.

[Molded body]
Next, the molded product according to the embodiment of the present invention will be described.

  FIG. 3 is a cross-sectional view showing an example of the molded product (using the insulated wire of FIG. 1) according to the embodiment of the present invention, and FIG. 4 shows the molded product according to the embodiment of the present invention. It is a cross-sectional view which shows another example (using the cable of FIG. 2).

  A molded body 100 according to an embodiment of the present invention includes the above-described insulated wire 10 according to an embodiment of the present invention and a molding material 4 provided on the outer periphery of the insulated wire 10.

  The molded body 200 according to the embodiment of the present invention includes the cable 20 according to the embodiment of the present invention and the molding material 4 provided on the outer periphery of the cable 20.

  As the molding material 4, for example, a polyamide resin or a polyurethane resin can be used.

  The method of providing the molding material 4 on the outer periphery of the insulated wire 10 and the cable 20 is not particularly limited, and for example, it can be provided by fusing.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

[Production of compound]
The contents of the blend are as described in Table 1. The fluorine-containing elastomer composition was produced as follows. Each compounding agent was put into a kneader maintained at 160 ° C., melted and kneaded while raising the temperature to 250 ° C., then put into a short shaft extruder, extruded into a strand shape, passed through a pelletizer, and formed into a pellet shape.

[Manufacture of insulated wires]
A fluorine-containing elastomer composition was extrusion-coated on a copper conductor having a cross-sectional area of 0.5 mm ² so as to have an outer diameter of 1.7 mm using an extruder having a cylinder diameter of 80 mm. In this case, the set temperature of the extruder was set to 240 ° C. for all of the cylinder, head, and die. The extruded electric wire was irradiated with a 15 kGy electron beam and cross-linked to prepare a cross-linked electric wire for each example / comparative example.

[Atmospheric pressure plasma treatment]
Plasma treatment was performed on the insulated wire using an atmospheric pressure plasma jet apparatus (manufactured by Nippon Plasma Treat Co., Ltd.). The nozzle hole had a diameter of 20 mm and the irradiation width was 20 mm. The scanning speed (m / min), the distance from the nozzle hole to the insulated wire, and the gas type are as described in Table 2.

[Manufacture of molded products]
As shown in FIG. 3, the periphery of the insulated wire was molded by injection molding with a glass filler-containing polyamide resin (manufactured by DuPont, Zytel FE5382). Moreover, the plasma-processed insulated wire molded the plasma-processed site | part.

[Evaluation]
1. Airtightness evaluation (experimental method)
As shown in FIG. 5, with the sample 4 immersed in the water 42 of the water tank 41, compressed air was fed into the end of the electric wire 10 from the air supply device 43 at 50 kPa for 30 seconds. In the meantime, the case where there was no air bubble 44 between the molding material 4 and the electric wire 10 was determined to be acceptable.

(Evaluation method)
The sample was subjected to a heat shock test under the conditions of −40 ° C. × 30 minutes and 125 ° C. × 30 minutes, and the pass rate at 0, 500, 1000, 2000, 3000, 4000, and 5000 cycles (number of specimens 10). A sample having a pass rate of 100% even after 2000 cycles or more was judged to be sufficiently airtight.

2. Surface analysis The surface state of the manufactured insulated wire was analyzed by X-ray photoelectron spectroscopy. As an analyzer, AXIS-HS manufactured by Shimadzu / KRATOS was used. The narrow scan spectrum of carbon (C) atoms was separated into waveforms, and the ratio of C═O bond amount to C—C bond amount (C═O / C—C) was determined.

  In Examples 1 to 6, which are within the range defined by the present invention, the airtightness between the insulated wire and the molding material was acceptable.

In Comparative Example 1, argon (Ar) gas, which is an inert gas, was used as the gas type, and the amount of carbonyl groups generated with respect to the C—C bond was not sufficient, and thus hermeticity was unacceptable.
In Comparative Example 2, since the distance from the nozzle hole of the atmospheric pressure plasma jet apparatus to the insulated wire was too far, the airtightness was unacceptable.
In Comparative Example 3, since atmospheric pressure plasma treatment was not performed, the amount of carbonyl groups generated with respect to the C—C bond was extremely small, and hermeticity was unacceptable.

  In addition, this invention is not limited to the said embodiment and Example, A various deformation | transformation implementation is possible.

1: Conductor, 2: Insulating layer, 3: Sheath, 4: Mold material 10: Insulated wire, 20: Cable 100, 200: Molded body 41: Water tank, 42: Water, 43: Air supply machine, 44: Air bubbles

Claims (10)

  An insulated wire comprising an outermost layer made of a fluorine-containing elastomer composition, wherein the outermost layer has a surface C = O bond to C-C bond ratio (C = O / C-C) of 0.5 or more.   The insulated wire according to claim 1, wherein the fluorine-containing elastomer composition contains a tetrafluoroethylene / propylene copolymer as a base polymer.   The insulated wire according to claim 1, wherein the fluorine-containing elastomer composition contains 5 parts by mass or more and 60 parts by mass or less of calcium carbonate as an inorganic filler with respect to 100 parts by mass of the base polymer.   The insulated wire according to claim 1, wherein the outermost layer is subjected to atmospheric pressure plasma treatment.   The molded object provided with the insulated wire of any one of Claims 1-4, and the molding material provided in the outer periphery of the said insulated wire.   A cable comprising an outermost layer made of a fluorine-containing elastomer composition, wherein the outermost layer has a surface C = O bond to C-C bond ratio (C = O / C-C) of 0.5 or more.   The cable according to claim 6, wherein the fluorine-containing elastomer composition contains a tetrafluoroethylene / propylene copolymer as a base polymer.   The cable according to claim 6, wherein the fluorine-containing elastomer composition contains 5 to 60 parts by mass of calcium carbonate as an inorganic filler with respect to 100 parts by mass of the base polymer.   The cable according to any one of claims 6 to 8, wherein the outermost layer is subjected to an atmospheric pressure plasma treatment. A molded product comprising the cable according to any one of claims 6 to 9, and a molding material provided on an outer periphery of the cable.

Images