JP2017103157A - Cable and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cable capable of achieving excellent slidability without depending on blending techniques and a manufacturing method therefor.SOLUTION: A cable 10 has a silica membrane 6 on a surface of a sheath 4 which is an outermost coating layer. The silica membrane has convexoconcave on its surface. The outermost coating layer consists of a composition containing one or more kind selected from silicone, polyvinyl chloride, polyethylene, chlorinated polyethylene and chloroprene rubber. A process for forming the silica membrane is conducted by spraying plasma.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a cable and a manufacturing method thereof.

  In recent years, the use of cables has been diversified, and functional requirements such as flame resistance, heat resistance, flexibility, slidability, wear resistance, and flame resistance for cables have been increasing.

  In order to meet these functional requirements, development of a blending technique of an insulator material and a sheath material has been performed so far (see, for example, Patent Document 1).

JP 2002-367444 A

  However, for example, it takes a lot of time and labor to develop a blending technology that can satisfy various other functional requirements while satisfying slidability. For this reason, it has been difficult to quickly respond to the user's demands.

  Therefore, an object of the present invention is to provide a cable capable of realizing excellent slidability and a method for manufacturing the same, regardless of the blending technique.

  In order to achieve the above object, the present invention provides the following cable and manufacturing method thereof.

[1] A cable having a silica film on the surface of the outermost coating layer.
[2] The cable according to [1], wherein the silica film is provided on a surface of the outermost coating layer in a state of being separated into a plurality of sections.
[3] The cable according to [1] or [2], wherein the silica film has irregularities on a surface thereof.
[4] The outermost coating layer is any one of [1] to [3], which is composed of a composition containing at least one selected from silicone, polyvinyl chloride, polyethylene, chlorinated polyethylene, and chloroprene rubber. Cable described in.
[5] The cable manufacturing method according to any one of [1] to [4], including a step of forming the silica film on a surface of the outermost coating layer.
[6] The method for manufacturing a cable according to [5], wherein the step of forming the silica film is performed by spraying plasma.
[7] The cable manufacturing method according to [5] or [6], wherein the step of forming the silica film is performed after the step of cleaning the surface of the outermost coating layer.

  According to the present invention, it is possible to provide a cable capable of realizing excellent slidability and a method for manufacturing the same regardless of the blending technique.

It is a cross-sectional view showing an example of a cable according to an embodiment of the present invention. It is a figure which shows the manufacture example of the cable which concerns on embodiment of this invention. It is a figure which shows the manufacture example of the film-forming sheet base material evaluated in the Example. It is a photograph which shows the state of the film | membrane surface of an Example and a comparative example. It is a graph which shows the static friction coefficient of an Example and a comparative example. It is the photograph which shows the state of the film | membrane surface of the Example which performed the bending test, (a) is the state of the film | membrane surface before a bending test, (b) is the state of the film | membrane surface after 100 times of bending | flexion, (c) is bending | flexion. The state of the film surface after 300 times, (d) is a photograph showing the state of the film surface after 500 times of bending. It is the photograph which shows the state of the film | membrane surface of the Example which performed the extending | stretching test, (a) is the state of the film | membrane surface before an extending | stretching test, (b) is the state of the film | membrane surface after 30% of extending | stretching, (c) is extending | stretching. The film surface state after 100%, (d) is a photograph showing the film surface state after returning to 0% after 100% stretching.

〔cable〕
The cable according to the embodiment of the present invention has a silica film on the surface of the outermost coating layer.

  A cable according to 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 a cable according to an embodiment of the present invention.

  A cable 10 according to the present embodiment shown in FIG. 1 includes a twisted core 5 in which three electric wires 3 are twisted together, a sheath 4 that is extrusion-coated on the outer periphery of the twisted core 5, and an outer periphery of the sheath 4. And a formed silica film 6. The electric wire 3 may be a single core or a multi-core stranded wire other than a three-core.

  The electric wire 3 includes a conductor 1 made of a general-purpose material, such as pure copper or tin-plated copper, and an insulator 2 coated on the outer periphery of the conductor 1. The insulator 2 is not particularly limited as long as it can be used as an insulator material for electric wires. For example, rubber materials such as polyethylene, polyvinyl chloride, kapton, silicone, ethylene propylene (EPR), ETFE, It is made of fluorine resin such as FEP, PFA, PTFE and the like. The number of conductors 1 is not limited to one, and a plurality of strands may be twisted.

  The sheath 4 is not particularly limited as long as it can be used as a sheath material. For example, silicone, polyvinyl chloride, polyethylene, chlorinated polyethylene, and chloroprene rubber are preferable. In particular, when the sheath 4 is made of a material having low slidability, that is, a material having high frictional force or a material having high adhesiveness, the application value of the present invention is high. For example, rubber compositions such as silicone and chloroprene rubber that are accompanied by adhesion (stickiness) having a static friction coefficient μ of 0.7 or more when used as a sheet base material can be mentioned as representatives. The above materials can be used not only alone but also as a composition containing two or more kinds.

  A general compounding agent such as various crosslinking agents, crosslinking catalysts, anti-aging agents, plasticizers, lubricants, fillers, flame retardants, stabilizers, and colorants may be added to the composition that becomes the sheath material.

  The sheath 4 can be provided by extrusion coating, and is subjected to a crosslinking treatment as necessary.

  The sheath 4 can also have a multilayer structure. In this case, if the outermost layer of the multilayer structure is made of the above-mentioned material, the applicability of the present invention is high.

  The silica film 6 is preferably provided on the surface of the sheath 4 that is the outermost coating layer in a state of being separated into a plurality of sections. The “state separated into a plurality of sections” means, for example, a state separated into a plurality of island-shaped portions as shown in photographs (FIGS. 6 and 7) taken in an example described later. It can be said that the film has cracks. The plurality of sections (island-shaped portions) may increase when the cable is bent or stretched. That is, the number of cracks in the film may increase. During bending or expansion / contraction, the width (gap) of the crack widens or narrows (particularly, see FIGS. 7C and 7D). Thereby, it is considered that the silica film 6 is hardly peeled off even if the cable is bent or stretched.

The surface area of each compartment (island portion) are those often in the range of 25μm ² ~1600μm ^2. The number and shape of the compartments are not particularly limited.

  Moreover, as the silica film 6 is shown by the photograph (refer to B section in FIG. 5) image | photographed in the Example mentioned later, it is preferable that the surface has an unevenness | corrugation. Thereby, since a contact area with the thing which contacts when a cable is moved can be made small, a frictional force further reduces and slidability improves. Specifically, for example, the surface roughness is preferably 0.2 μm or more, more preferably 0.5 μm or more, and further preferably 1.0 μm or more in arithmetic mean roughness (Ra). preferable.

  The thickness of the silica film 6 is not particularly limited, but is preferably 0.2 μm or more, and more preferably 1 μm or more.

  In the present embodiment, a separator, a braid, a shield tape made of metal foil, or the like may be further applied as necessary.

  The cable according to the embodiment of the present invention can be applied to cables for various uses. In particular, cables such as medical cables (endoscope cables, probe cables, catheter cables, etc.) and cabtire cables, or contacts with each other. Suitable for applications where friction with objects is a concern.

[Cable manufacturing method]
A cable manufacturing method according to an embodiment of the present invention is a cable manufacturing method according to the above-described embodiment of the present invention, and includes a step of forming the silica film described above on the surface of the outermost coating layer of the cable described above. .

  A cable manufacturing method according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 2 is a diagram showing an example of manufacturing the cable according to the embodiment of the present invention.

  The steps until the sheath 4 of the outermost coating layer is provided can be performed by a method similar to a known cable manufacturing method, and thus the description thereof is omitted.

  After producing the cable 10A (the cable 10 before forming the silica film 6) in which the sheath 4 is the outermost coating layer, the cable 10A is moved inline in the direction of the arrow (right direction) in FIG. Then, the silica film 6 is formed.

  The step of forming the silica film 6 can be performed, for example, by spraying plasma. For example, the plasma is preferably sprayed at 5 to 150 ° C. in an atmospheric pressure atmosphere. As for atmospheric temperature, 80 degrees C or less is more preferable. This method is preferable in that film formation can be performed on the cable surface at a low temperature and under atmospheric pressure.

Specifically, as shown in FIG. 2, using a film forming apparatus 30 (pulse power supply) capable of generating plasma, air or N ₂ gas 21 is supplied to the film forming apparatus 30 from the end of the apparatus. The air or N ₂ gas 21 molecules are turned into plasma by discharge inside the apparatus. Subsequently, Si-containing material gas 31 (for example, hexamethyldisiloxane (HMDSO)) is introduced from the side of the apparatus 30 to cause the generated air or N ₂ plasma gas to collide with material gas molecules. The material molecules are turned into plasma (ion, electron and activated molecules are generated). Silica film 6 is formed on the surface of sheath 4 by jetting the plasma-formed film material gas 32 containing air or N ₂ plasma gas from the tip of device 30 toward cable 10A. The position of the plasma nozzle is adjusted and the reflector is provided so that at least two or more film forming apparatuses 30 are provided at a plurality of locations so that the film is formed on the entire circumference of the cable 10A, or the plasma gas flows around the back surface. Adopting means such as providing. Thereby, the cable 10 in which the silica film 6 is formed over the entire circumference can be obtained. As the film forming apparatus 30, for example, a commercial name: PlasmaPlus (registered trademark) manufactured by Plasmatreat Co., Ltd. can be used.

  The step of forming the silica film 6 is preferably performed after the step of cleaning the surface of the sheath 4 that is the outermost coating layer. Thereby, the silica film 6 can be made more difficult to peel off from the surface of the sheath 4.

Specifically, for example, as shown in FIG. 2, using a cleaning device 20 (pulse power source) capable of generating plasma, plasma is generated by discharging 21 molecules of air or N ₂ gas inside the device. To do. The generated plasma 22 is ejected from the tip of the device 20 toward the cable 10A, whereby the surface of the sheath 4 is cleaned. In order to clean the entire circumference of the cable 10A, at least two film forming apparatuses 20 are provided at a plurality of positions, or the position of the plasma nozzle is adjusted so that the plasma gas flows around the back surface, and a reflector is provided. Adopting means such as providing. As the purification apparatus 20, the same apparatus as the film forming apparatus 30 can be used, which is different from the film forming process in that only the air or N ₂ gas 21 is allowed to flow into the apparatus without flowing the material gas 31.

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

[Observation of surface of silica film and measurement of static friction coefficient]
FIG. 3 is a diagram showing a production example of a film forming sheet base material evaluated in Examples.
As shown in FIG. 3, using a film forming apparatus 30 (trade name: PlasmaPlus (registered trademark), manufactured by Plasmatreat), silica is formed on the surface of a sheet base material 40 (thickness 1.5 mm, length 100 mm × width 100 mm). A film 16 was formed. The thicknesses were set to about 200 nm, 400 nm, and 600 nm, respectively, at a rate of 100 mm / s, 50 mm / s, and 25 mm / s in the arrow direction Y (left direction) in FIG. 3 (50 mm / s and 25 mm / s is carried out only when silicone is used as the base material).

  As the sheet substrate 40, silicone, polyvinyl chloride (PVC), and chlorinated polyethylene were used, air was used as the gas 21, and hexamethyldisiloxane was used as the material gas 31.

  After film formation on the sheet base material 40, the film surface of the silica film 16 was observed and the static friction coefficient was measured.

  FIG. 4 is a photograph showing the state of the film surfaces of Examples and Comparative Examples (when silicone is used as the sheet base material 40), and the left half of the figure is the surface of the non-film-formed sheet base material 40 (Comparative Example). The right half of the figure is the surface (Example) of the sheet base material 40 on which the silica film 16 having a film thickness of 200 nm is formed.

  The arithmetic average roughness (Ra) measured in the A region (comparative example) and the B region (example) in FIG. The arithmetic average roughness (Ra) was measured using a Keyence Corporation laser microscope system (VK-8500).

  As can be seen from Table 1, the arithmetic average roughness (Ra) of the surface of the sheet base material 40 on which the silica film 16 was formed was increased compared to the surface of the non-film-formed sheet base material 40.

  FIG. 5 is a graph showing the static friction coefficients of Examples and Comparative Examples. “No treatment” described on the horizontal axis of the graph is a measurement result of the static friction coefficient of the surface (comparative example) of an undeposited sheet base material 40, and “100 mm / s, 50 mm / s, 25 mm / s” are the respective results. It is a measurement result of the static friction coefficient of the surface (Example) of the sheet | seat base material 40 which formed the silica film 16 at the film processing speed.

  A set of sheet base materials 40 produced under the same conditions were overlapped so that the silica films 16 were in contact with each other, and the static friction coefficient was calculated by measuring the static friction coefficient in accordance with JIS K7125. Moreover, the static friction coefficient was calculated by superimposing a set of unformed film base materials 40 and measuring the static friction coefficient in accordance with JIS K7125.

  As can be seen from FIG. 5, the static friction coefficient of the surface of the sheet base material 40 on which the silica film 16 was formed was reduced compared to the surface of the non-film-formed sheet base material 40 in each case. In particular, the coefficient of static friction was reduced to about 1/5 for silicone. From the results of FIGS. 4 and 5, the hard silica film 16 is formed on the adhesive silicone surface, whereby the adhesiveness is suppressed, and the silica film 16 has unevenness, so that the contact area is small. It is considered that the static friction coefficient was reduced.

[Bending test and stretching test]
As shown in FIG. 3, using a film forming apparatus 30 (trade name: PlasmaPlus (registered trademark), manufactured by Plasmatreat), silica is formed on the surface of a sheet base material 40 (thickness 1.5 mm, length 20 mm × width 10 mm). A film 16 (thickness 600 nm) was formed. Film formation was performed at a speed of 25 mm / s in the direction of arrow Y (leftward) in FIG.

  Silicone and chloroprene rubber were used as the sheet base material 40, air was used as the gas 21, and hexamethyldisiloxane was used as the material gas 31.

  After the silica film 16 was formed on the sheet base material 40, each test was performed by the following method.

(Bending test)
Photographs of the film surface after repeated bending of + 90 ° were performed 100 times, 300 times, and 500 times on the formed sheet base material 40, respectively, were taken. Moreover, arithmetic mean roughness (Ra) was measured by the method mentioned above (a result is shown in Table 2). The repeated bending was performed at a speed of 10 times / minute by counting the operation of bending and returning to the original state until the radius of curvature r was about 2 mm.

  FIG. 6 is a photograph showing the state of the film surface of an example (when silicone is used as the sheet base material 40) subjected to the bending test, (a) is the state of the film surface before the bending test, and (b). (C) is a photograph showing the state of the film surface after 300 bends, (d) is a photograph showing the state of the film surface after 500 bends.

  In any case after 100 times of bending, 300 times, and 500 times, no film peeling was observed. Moreover, it turns out that the number of divisions is increasing, so that the number of bends increases compared with before a bending test (FIG. 6 (a)) (FIG. 6 (b)-(d)).

  As can be seen from FIG. 6 and Table 2, even if the number of sections increased as the number of bends increased, the arithmetic average roughness did not vary greatly, and the static friction coefficient did not change significantly.

  In the case of chloroprene rubber as the sheet base material 40, the initial stickiness is large and has a static friction coefficient of 1.5 or more, but it was possible to reduce it to 0.7 by performing the same film forming treatment.

(Extension test)
Photographs of the film surface when 30% stretching, 100% stretching, and 0% stretching (return to the original) were sequentially performed on the formed film base material 40 (using silicone) were taken.

  FIG. 7 is a photograph showing the state of the film surface of the example subjected to the stretching test, (a) is the state of the film surface before the stretching test, (b) is the state of the film surface after 30% stretching, ( c) is a photograph showing the state of the film surface after 100% stretching, and (d) is a photograph showing the state of the film surface after returning to 0% stretching after 100% stretching.

In any case of 30% after stretching, 100% after stretching, and 0% after stretching (return to original), no film peeling was observed. Moreover, it turns out that the number of divisions is increasing compared with the drawing test (FIG. 7A) (FIGS. 7B to 7D). 7C and 7D are schematic diagrams showing the state of the compartment, and the width of the crack forming the compartment is widened by stretching and narrowed by returning to the original state. Indicates that
Further, as a result of evaluating the static friction coefficient before and after stretching, it was a value substantially equal to 0.23 before stretching and 0.24 after stretching.

[Evaluation of cable slidability]
A cable having the structure shown in FIG. 1 was manufactured by the following method, and slidability was evaluated.

The size of each part of the cable (electric wire: 3 × 22 mm ² ) is as follows.
Conductor configuration (conductor outer diameter / number of strands / strand diameter): 7 mm / 20 strands / 0.45 mm
・ Insulator thickness: 1.2 mm
-Sheath thickness: 2.7 mm
-Finished outer diameter: 26mm

  The electric wire 3 was obtained by extruding and covering each color (red, white, black) of sulfur-crosslinked EPR (ethylene propylene rubber) as an insulator 2 on the conductor 1 to a predetermined thickness and then crosslinking with pressurized steam.

  These three (each color) electric wires 3 were twisted to obtain a twisted core 5. The sheath material was extrusion coated on the outer periphery of the twisted core 5 at a speed of 5 m / min by an extruder. Silicone or chloroprene rubber was used as the sheath material.

  After covering the sheath, the surface of the sheath was cleaned with the apparatus shown in FIG. 2, and then a silica film 16 (film thickness: 0.5 μm) was formed on the sheath surface. A cable formed with a silica film was used as a sample of the example, and a cable that was not formed was used as a sample of a comparative example.

  Each of the cables of the example and the comparative example was cut out by 20 cm, and it was measured how many times the operation of taking out and putting it in a polyethylene bag (8.5 cm (opening) × 12 cm) can be performed in 30 seconds. The results are shown in Table 3.

  As can be seen from Table 3, when the sheath material is silicone or chloroprene rubber, the example (cable with the silica film formed) is more in comparison with the comparative example (cable with no silica film formed). It was clearly confirmed that the silica film of the present invention can reduce not only the same silica film but also the static friction coefficient with different materials such as polyethylene.

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

1: conductor, 2, 2a, 2b: insulator, 3: wire, 4: sheath 5: twisted core, 6, 16: silica film 10: cable (film-formed), 10A: cable (not-formed film)
20: cleaning device, 21: air / N ₂ gas, 22: plasma 30: film formation device, 31: material gas 32: air or N ₂ gas molecules converted into plasma and film formation material molecules 40 converted into plasma Sheet base material

Claims (7)

  A cable having a silica film on the surface of the outermost coating layer.   The cable according to claim 1, wherein the silica film is provided on a surface of the outermost coating layer in a state of being separated into a plurality of sections.   The cable according to claim 1, wherein the silica film has irregularities on a surface thereof.   The cable according to any one of claims 1 to 3, wherein the outermost coating layer is made of a composition containing at least one selected from silicone, polyvinyl chloride, polyethylene, chlorinated polyethylene, and chloroprene rubber. It is a manufacturing method of the cable given in any 1 paragraph of Claims 1-4,
A cable manufacturing method comprising a step of forming the silica film on a surface of the outermost coating layer.   The method of manufacturing a cable according to claim 5, wherein the step of forming the silica film is performed by spraying plasma.   The method for manufacturing a cable according to claim 5 or 6, wherein the step of forming the silica film is performed after the step of cleaning the surface of the outermost coating layer.