JP5155636B2 - Cable assembly forming tape and manufacturing method thereof - Google Patents

Description

  The present invention relates to a cable assembly forming tape used for forming a cable assembly and a manufacturing method thereof.

  In recent years, for example, in a mobile phone, two casings 6A and 6B as shown in FIG. 3 are connected by a hinge portion 60, and the other casing 6B is indicated by an arrow a in FIG. Thus, a structure that can be rotated in the lateral direction is employed. In such a structure, the insertion hole 60a is provided in the hinge part 60, and the cable assembly 9 is arrange | positioned through this insertion hole 60a.

  In the cable assembly 9, a pair of connectors 8 extending in a predetermined direction are connected by a plurality of cables 7, and a portion passing through the insertion hole 60 a of the cable 7 is bound in a substantially cylindrical shape by a binding tape 10. . The binding tape 10 has an adhesive layer formed on one surface of a base material as described in, for example, Patent Document 1, and the base cable is easy to bend the cable after binding and the insertion hole 60a. A polytetrafluoroethylene (hereinafter referred to as “PTFE”) film that is excellent in flexibility and has low friction characteristics so as to move smoothly inside is often used.

In order to form such a cable assembly 9, after a plurality of cables 7 are inserted through the insertion holes 60a, the cables 7 are fixed (temporarily fixed) to a temporary fixing tape in a state where they are aligned at a predetermined pitch. 7 is connected to the connector 8. Thereafter, the temporary fixing tape is peeled off, and the adhesive tape 10 is wound around a predetermined position of the cable 7. As the temporary fixing tape, one having dimensional stability so that the pitch of the cable 7 does not shift is preferable, and one using a polyester film as a base material is often used.
JP 2002-28859 A

  As described above, since two types of tape are used for forming the cable assembly 9 depending on the purpose, there is a demand for making it possible to form the cable assembly with one tape. However, since PTFE films are easy to stretch, the cable pitch may be shifted when used temporarily, and polyester films are difficult to stretch. When used for binding, the cable after binding is difficult to bend.

  In view of such circumstances, an object of the present invention is to provide a cable assembly bundling tape that can be suitably used for both temporary fixing and bundling and a method for manufacturing the tape.

  The inventor of the present invention can achieve the above object by using as a substrate a PTFE porous membrane stretched only in a uniaxial direction at a predetermined stretching ratio as a result of intensive studies to achieve the above object. I found out. That is, the present invention relates to a cable assembly forming tape used for forming a cable assembly, the PTFE porous membrane having a structure in which fibrils extend in the longitudinal direction of the tape and nodes extend in the width direction of the tape; A tape for forming a cable assembly is provided, comprising an adhesive layer formed on one surface of the porous PTFE membrane.

  The present invention also relates to a method for manufacturing a cable assembly forming tape used for forming a cable assembly, wherein a sheet-like molded body made of PTFE extending in a predetermined direction is not less than 4 times and not more than 30 times only in the predetermined direction. A method for producing a cable assembly forming tape is provided in which a PTFE porous membrane is produced by stretching at a magnification, and an adhesive is applied to one surface of the PTFE porous membrane to form an adhesive layer.

  ADVANTAGE OF THE INVENTION According to this invention, the tape for cable assembly formation which cannot be extended easily in a longitudinal direction and is easy to extend in the width direction can be obtained. Therefore, if used for temporary fixing, the pitch of the cable can be maintained, and if used for bundling, the flexibility of the cable after bundling is improved.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, a cable assembly forming tape 1 according to an embodiment of the present invention (hereinafter simply referred to as “tape 1”) includes a PTFE porous membrane 2 and one surface of the PTFE porous membrane 2. And an adhesive layer 3 formed thereon.

  The PTFE porous membrane 2 has an unfired structure in which fibrils extend in the longitudinal direction of the tape 1 (direction perpendicular to the paper surface of FIG. 1) and nodes extend in the width direction of the tape 1 (left-right direction in FIG. 1). Is. When the fired PTFE porous membrane is used, the adhesive force of the adhesive surface (the surface of the adhesive layer) against the self-back surface (the other surface of the PTFE porous membrane) when wound around the cable is weak, and the tape may be easily peeled off However, if the porous PTFE membrane is not fired, sufficient adhesive strength can be obtained.

  The elongation at break in the longitudinal direction of the tape 1 of the porous PTFE membrane 2 having the adhesive layer 3 is preferably 200% or less. This is because when the tape has a break elongation exceeding 200%, when the cable is temporarily fixed at a predetermined pitch, the tape may extend and the cable pitch may be greatly disturbed. More preferably, the elongation at break is 100% or more and 200% or less.

  Moreover, it is preferable that the breaking strength in the longitudinal direction of the tape 1 of the porous PTFE membrane 2 having the adhesive layer 3 is 50 MPa or more and 80 MPa or less. If the tape has a breaking strength of less than 50 MPa, elongation may occur during the bonding process and the thickness may become non-uniform. If the tape has a breaking strength of more than 80 MPa, shrinkage occurs after the bonding process. This is because the cable pitch may be greatly disturbed.

  The thickness of the PTFE porous membrane 2 is preferably 20 μm or more and 60 μm or less. If the thickness is too small, there is a high risk that the tape will be torn during handling.If the thickness is too large, the cable is bonded to the tape to pass the cable through the insertion hole in the hinge, and the tape is rolled. This is because the outer diameter becomes large.

  The adhesive layer 3 is formed by applying a silicone adhesive or an acrylic adhesive. In addition, as shown in FIG. 2, when a tape 1 is wound around a core material to constitute a wound body, a release agent such as silicone fluoride is applied on at least one surface to release layer. You may make it cover the adhesion layer 3 with the separator 5 in which 4 was formed.

  Next, a method for manufacturing the tape 1 will be described.

  First, a paste-like mixture obtained by adding a liquid lubricant to PTFE fine powder is preformed. PTFE fine powder is suitable as a PTFE raw material because of the ease of paste extrusion. The liquid lubricant is not particularly limited as long as it can wet the surface of the PTFE fine powder and can be removed by extraction or heating. For example, hydrocarbons such as liquid paraffin, naphtha, and white oil can be used. . The addition amount of the liquid lubricant is suitably about 5 to 50 parts by weight with respect to 100 parts by weight of PTFE fine powder. The preforming is performed at a pressure that does not squeeze out the liquid lubricant.

  Subsequently, the obtained preform is preferably formed into a sheet-like molded body extending in a predetermined direction by paste extrusion, and the liquid lubricant is removed from the sheet-like molded body by a heating method or an extraction method.

  Thereafter, the sheet-like molded body is magnified 4 times to 30 times, more preferably 6 times to 20 times (more preferably 10 times or more) only in the uniaxial direction of the longitudinal direction, which is the direction in which the sheet-shaped molded body extends. The PTFE porous membrane 2 having a thickness of 15 to 100 μm is produced by stretching at a magnification of 20 times or less. This stretching is performed at a temperature lower than the melting point of PTFE in order to obtain an unsintered PTFE porous membrane 2, and the stretching temperature is usually in the range of 240 to 300 ° C., preferably 270 to 290 ° C. If stretching is performed at a temperature lower than 240 ° C., stretching at a high magnification becomes difficult and breakage occurs, or stretching unevenness occurs in the longitudinal direction or the width direction orthogonal to the longitudinal direction, and uniform stretching cannot be performed. There is a fear. On the other hand, if the stretching is performed at a temperature exceeding 300 ° C., the structure may be changed by being close to the melting point of PTFE.

  After obtaining the PTFE porous membrane 2, an adhesive is applied on one surface of the PTFE porous membrane 2 to form the adhesive layer 3. As the pressure-sensitive adhesive, either a silicone pressure-sensitive adhesive or an acrylic pressure-sensitive adhesive can be used, but when the cable sheath is a fluororesin, a higher adhesive force than the acrylic pressure-sensitive adhesive can be obtained. It is preferable to use a silicone-based adhesive.

  Finally, the separator 5 made of a polyester film and having the release layer 4 formed on one surface is made of a PTFE porous membrane so that the surface of the adhesive layer 3 and the surface of the release layer 4 are in contact with each other. Then, the laminate is conveyed by applying a pressure of 0.1 to 0.3 MPa with a pair of pressure-bonding rolls. Thus, a tape 1 having a thickness excluding the separator 5 (hereinafter referred to as “total thickness”) of 25 to 110 μm can be obtained.

  In addition, you may cut | disconnect the obtained tape 1 by desired width (10-150 mm) in the width direction. In order to construct a wound body as shown in FIG. 2, the tape 1 before or after cutting is wound so that the other surface of the PTFE porous membrane 2 and the other surface of the separator 5 are in contact with each other. That's fine.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not restrict | limited to these Examples at all.

Example 1
A PTFE fine powder was used to form a sheet-like molded body having a thickness of 0.17 mm by paste extrusion, and this sheet-like molded body was stretched 20 times only in the uniaxial direction at 280 ° C. to give a PTFE porous film having a thickness of 20 μm. Was made. A pressure-sensitive adhesive layer is formed on one surface of the obtained porous PTFE membrane using a silicone-based pressure sensitive adhesive, and a release layer is formed on one surface of the separator made of a polyester film having a thickness of 50 μm. The laminated separator was laminated, and this laminated body was passed between a pair of crimping rolls to obtain a cable assembly forming tape having a total thickness of 30 μm.

(Example 2)
A cable assembly-forming tape having a total thickness of 40 μm was obtained in the same manner as in Example 1 except that a 30-μm-thick PTFE porous membrane was prepared by increasing the draw ratio of the sheet-like molded product to 15 times.

(Example 3)
A cable assembly-forming tape having a total thickness of 70 μm was obtained in the same manner as in Example 1 except that a PTFE porous membrane having a thickness of 60 μm was prepared by increasing the draw ratio of the sheet-like molded body to 6 times.

Example 4
A cable assembly forming tape having a total thickness of 110 μm was obtained in the same manner as in Example 1 except that a 100-μm-thick PTFE porous membrane was prepared by increasing the draw ratio of the sheet-like molded body to 4 times.

(Example 5)
A cable assembly forming tape having a total thickness of 25 μm was obtained in the same manner as in Example 1 except that the stretch ratio of the sheet-like molded body was 30 times to prepare a PTFE porous membrane having a thickness of 15 μm.

(test)
1) Adhesive strength After the tapes of Examples 1 to 5 were cut into strips having a length of 250 mm and a width of 19 mm extending in the longitudinal direction of the tape, the separator was peeled off, stacked on a stainless steel plate, and a mass of 2 kg from above. The rubber roller was reciprocated once for adhesion. After 20 to 40 minutes had elapsed after bonding, the tape was pulled while being peeled off at a speed of 300 mm / min, and the adhesive force (tensile force) was measured.

2) Breaking strength and breaking elongation The tapes of Examples 1 to 5 were cut into strips having a length of 100 mm and a width of 20 mm extending in the longitudinal direction of the tape, and then the separator was peeled off. RTG-1310) manufactured by A & D Co., Ltd. was fixed on a chuck and pulled at a speed of 200 mm / min.

Strength (MPa) = Tensile force at break (N) ÷ Cross sectional area (Thickness × Width) (mm ² )
Elongation (%) = distance between chucks at break ÷ initial distance between chucks x 100
3) Cable temporary fixing test On the tapes of Examples 1 to 5, 40 cables with a diameter of 0.3 mm are aligned in a row at a pitch of 0.3 mm so as to be aligned in the longitudinal direction of the tape 1, and crimped. They were laminated using a roll. Thereafter, the tape was rolled from the end in the longitudinal direction to form a cable bundle, and the outer diameter of the cable bundle was measured.

  The results of the above test were as shown in Table 1.

  Since the tapes of Examples 1 to 5 were difficult to extend in the longitudinal direction and easily extended in the width direction, they could be suitably used for temporarily fixing and binding cables.

  Further, as can be seen from Table 1, since the outer diameter of the cable bundle is less than 3 mm, the cable bundle could be passed through the insertion hole having a diameter of 3 mm in the hinge portion. After that, when the tape was straightened out, the cable pitch was hardly disturbed, and was kept at about 0.3 mm. For this reason, the cable could be connected to the connector without realigning the cables. In Example 4, the outer diameter of the cable bundle was 2.9 mm, and it was difficult to pass through the insertion hole with a diameter of 3 mm. In Example 5, although the outer diameter of the cable bundle was 2.38 mm, the total thickness was very thin at 25 μm, so that wrinkles were easily generated when the cable was rolled.

  That is, if the tape of the present invention is used, the cable can be temporarily fixed and then passed through the insertion hole of the hinge portion, and if the tape is spread after passing through the insertion hole, the temporarily fixed state can be restored. Connection to the connector becomes easy.

  However, in Examples 1 to 3 in which the draw ratio was 6 to 20 times, the breaking elongation in the longitudinal direction when the separator was peeled was 200% or less, and the breaking strength in the longitudinal direction was 50 MPa or more and 80 MPa or less. I was able to keep it.

It is sectional drawing of the tape for cable assembly formation which concerns on one Embodiment of this invention. It is explanatory drawing which shows the state by which the tape of FIG. 1 was wound. It is explanatory drawing which shows the conventional cable assembly.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cable assembly formation tape 2 PTFE porous membrane 3 Adhesive layer 4 Release layer 5 Separator

Claims (7)

A cable assembly forming tape used for forming a cable assembly,
A polytetrafluoroethylene porous membrane having a structure in which fibrils extend in the longitudinal direction of the tape and nodes extend in the width direction of the tape, and an adhesive layer formed on one surface of the polytetrafluoroethylene porous membrane It equipped with a door,
A cable assembly forming tape, wherein the polytetrafluoroethylene porous membrane is unfired .   2. The cable assembly according to claim 1, wherein the polytetrafluoroethylene porous membrane having the adhesive layer has a breaking elongation of 200% or less and a breaking strength of 50 MPa or more and 80 MPa or less in the longitudinal direction of the tape. Tape.   The tape for forming a cable assembly according to claim 1 or 2, wherein the polytetrafluoroethylene porous membrane has a thickness of 20 µm to 60 µm.   The cable assembly forming tape according to any one of claims 1 to 3, wherein the adhesive layer is formed by applying a silicone-based adhesive. The separator further comprises a separator having a release layer formed on at least one surface, and the polytetrafluoroethylene porous membrane and the separator are laminated so that the surface of the adhesive layer and the surface of the release layer are in contact with each other. The cable assembly forming tape according to any one of claims 1 to 4 , wherein the tape is wound so that the other surface of the polytetrafluoroethylene porous membrane and the other surface of the separator are in contact with each other. A method for manufacturing a cable assembly forming tape used for forming a cable assembly, comprising:
A sheet-shaped molded body made of polytetrafluoroethylene extending in a predetermined direction is stretched at a magnification of 4 to 30 times only in the predetermined direction at 240 to 300 ° C. to produce a polytetrafluoroethylene porous film, A method for manufacturing a tape for forming a cable assembly, wherein an adhesive is applied on one surface of a polytetrafluoroethylene porous membrane to form an adhesive layer. The method for producing a cable assembly forming tape according to claim 6 , wherein a ratio of stretching the sheet-shaped molded body is 6 times or more and 20 times or less.

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