JP5626482B2 - Insulating film for flat cable and flat cable - Google Patents

Description

  The present invention relates to an insulating film for a flat cable and a flat cable.

Conventionally, a flat cable including an adhesive layer that covers a conductor and two base films sandwiching the adhesive layer is widely used. In such a flat cable, in order to allow access to the conductor bonded to the adhesive layer, it is necessary to provide openings at both ends in advance to expose the conductor. For this reason, a flat cable including an adhesive layer that adheres to a conductor is cut into a predetermined length in advance, and cannot be used after being cut into an arbitrary length during use.
In addition, a flat cable including a polyvinyl chloride resin layer covering a conductor and two base films sandwiching the polyvinyl chloride resin layer is also widely used (see, for example, Patent Document 1). In such a flat cable, since the polyvinyl chloride resin layer is not bonded to the conductor, the polyvinyl chloride resin layer can be pulled out of the conductor by making cuts at both ends of the flat cable. Therefore, a flat cable including a polyvinyl chloride resin layer that does not adhere to a conductor does not need to be cut into a predetermined length in advance, and can be cut into an arbitrary length when used.

JP 2001-250429 A

On the other hand, in recent years, development of a flat cable that does not contain a polyvinyl chloride resin is desired as an environmentally compliant product that complies with safety standards (UL standard, CSA standard, SAE-AMS standard, etc.).
However, as a flat cable that can be used after being cut to an arbitrary length, only a cable including a polyvinyl chloride resin described in Patent Document 1 has been proposed. Moreover, when using resin other than a polyvinyl chloride resin, the drawability from the conductor of a resin layer must be favorable.

  This invention is made | formed in view of the above-mentioned situation, and provides the insulating film for flat cables and flat cable which do not contain a polyvinyl chloride resin and the drawing property from the conductor of a resin layer is favorable. With the goal.

  The insulating film for flat cables which concerns on the 1st viewpoint of this invention is equipped with the resin layer which has the surface layer containing polyolefin resin, and the support layer which supports a resin layer. The dynamic friction coefficient of the surface of the resin layer is 0.5 or more and 1.0 or less when measured according to JISK7125.

  A flat cable according to a second aspect of the present invention includes a first resin layer having a first surface layer containing a polyolefin-based resin, a first support layer that supports the first resin layer, a polyolefin-based resin, A second resin layer having a second surface layer thermally fused to one surface layer, a second support layer supporting the second resin layer, and a conductor embedded between the first resin layer and the second resin layer; . The dynamic friction coefficient of the first contact surface in contact with the conductor in the first surface layer and the dynamic friction coefficient of the second contact surface in contact with the conductor in the second surface layer are 0.5 or more and 1 when measured according to JISK7125. 0.0 or less.

  ADVANTAGE OF THE INVENTION According to this invention, the insulation film and flat cable for flat cables which do not contain a polyvinyl chloride resin and are favorable in the drawability from the conductor of a resin layer can be provided.

Cross section of insulation film Perspective view of flat cable AA sectional view of FIG. Cross section of insulation film

  Embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, the drawings are schematic, and the ratio of each dimension may be different from the actual one. Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

(Configuration of insulating film 100)
The configuration of the insulating film 100 according to the embodiment will be described with reference to the drawings. FIG. 1 is a cross-sectional view of the insulating film 100.

  The insulating film 100 is suitably used for producing a flat cable 200 (see FIG. 2) described later. The insulating film 100 includes a support layer 10, an anchor coat layer 20, and a resin layer 30.

  The support layer 10 supports the anchor coat layer 20 and the resin layer 30. The support layer 10 is preferably made of a material having insulating properties, flexibility, heat resistance, chemical resistance, and the like. Examples of such materials include polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate, polyimide resins, polyphenylene sulfide resins, polyamide resins, and liquid crystal polymers. The thickness of the support layer 10 can be 9 μm or more and 50 μm or less. The width and length of the support layer 10 can be set according to the dimensions of the flat cable 200.

  The anchor coat layer 20 is interposed between the support layer 10 and the resin layer 30 in order to improve the adhesion between the support layer 10 and the resin layer 30. The anchor coat layer 20 is preferably composed of a thermosetting resin. Examples of the thermosetting resin include a two-component urethane adhesive and a two-component olefin adhesive. The thickness of the anchor coat layer 20 can be 1 μm or more and 10 μm or less.

  The resin layer 30 is disposed on the anchor coat layer 20. The resin layer 30 is supported by the support layer 10. The resin layer 30 according to the present embodiment has a single layer structure. The resin layer 30 has heat fusibility. Therefore, the resin layers 30 can be heat-sealed by heating in a state where the resin layers 30 of the two insulating films 100 are in close contact with each other. The resin layer 30 contains a polyolefin resin. The resin layer 30 may contain a polyolefin resin as a main component. Examples of polyolefin resins include α-olefin homopolymers or copolymers such as polyethylene, polypropylene, and polybutene, ionomer resins, and acid-modified polyolefins. On the other hand, the resin layer 30 according to the present embodiment does not contain a polyvinyl chloride resin. The thickness of the resin layer 30 can be 20 μm or more and 100 μm or less.

  Further, a lubricant composed of a fatty acid ester or a fatty acid amide is added to the resin layer 30. Examples of the lubricant composed of the fatty acid ester include glycerin fatty acid ester and propylene glycol fatty acid ester. Examples of the lubricant composed of fatty acid amides include erucic acid amide, stearic acid amide, lauric acid amide, oleic acid amide, and behenic acid amide.

  In addition, a flame retardant or a filler component other than the flame retardant may be added to the resin layer 30. Examples of the flame retardant include flame retardants containing halogens such as chlorine and bromine, and non-halogen flame retardants such as phosphorus flame retardants, nitrogen flame retardants, metal hydroxide flame retardants, and the like. Examples of the filler component include silica fine particles, talc, calcium carbonate, and pigment. In addition, when the resin layer 30 has a multilayer structure, the presence or absence, addition amount, etc. of a flame retardant and a filler component can be changed for every layer.

  Here, the resin layer 30 has a surface 30S on which a conductor 220 (see FIG. 2) described later is placed. The dynamic friction coefficient of the surface 30S is preferably 0.5 or more and 1.0 or less when measured by a dynamic friction coefficient test method based on JIS K7125 (a load of 200 g on a rolled copper foil having a thickness of 25 μm as a sliding piece). . The dynamic friction coefficient of the surface 30S can be controlled by adjusting the content of the lubricant in the “surface layer” forming the surface 30S of the resin layer 30. The content of the lubricant in the resin layer 30 “surface layer” is preferably 0.01 parts by mass or more and 1.00 parts by mass or less with respect to 100 parts by mass of the polyolefin resin.

Further, the tensile elastic modulus of the “surface layer” forming the surface 30S in the resin layer 30 is preferably 300 MPa or more, and more preferably 800 MPa or more. Such tensile elastic modulus can be controlled by selecting the type of polyolefin resin constituting the “surface layer”.
When the resin layer 30 has a single layer structure as in the present embodiment, the entire resin layer 30 is a “surface layer”, but when the resin layer 30 has a multilayer structure, the outermost layer (that is, The layer farthest from the support layer 10) is the “surface layer”. The case where the resin layer 30 has a multilayer structure will be described later.

(Configuration of flat cable 200)
The configuration of the flat cable 200 according to the embodiment will be described with reference to the drawings. FIG. 2 is a perspective view of the flat cable 200. FIG. 3 is a cross-sectional view taken along the line AA of FIG.

  As shown in FIG. 2, the flat cable 200 includes a covering member 210 and a plurality of conductors 220. The flat cable 200 is used for internal wiring of a liquid crystal television or a digital camera, for example. When the flat cable 200 is used, both ends of the conductor 220 are exposed by pulling the first end 210A and the second end 210B of the covering member 210 outward (in the direction of the arrow in the figure). A support substrate or the like is attached to both ends of the exposed conductor 220. The width and length of the flat cable 200 can be set according to the application.

  The covering member 210 is constituted by two insulating films 100 (see FIG. 1) that are heat-sealed. Specifically, as shown in FIG. 3, the covering member 210 includes a first support layer 10A, a first anchor coat layer 20A, a first resin layer 30A, a second support layer 10B, and a second anchor coat layer. 20B and the second resin layer 30B. In the present embodiment, the entire first resin layer 30A is a “first surface layer”, and the entire second resin layer 40A is a “second surface layer”.

  Each of the first support layer 10A and the second support layer 10B has a configuration similar to that of the support layer 10 described above. Each of the first anchor coat layer 20A and the second anchor coat layer 20B has the same configuration as the anchor coat layer 20 described above. Each of the first resin layer 30 </ b> A and the second resin layer 30 </ b> B has the same configuration as the resin layer 30 described above. The first resin layer 30A and the second resin layer 30B are heat-sealed by being heated to about 100 ° C. to 200 ° C., for example.

  Here, the first resin layer 30 </ b> A has a first contact surface 30 </ b> Sa that contacts the conductor 220. The second resin layer 30 </ b> B has a second contact surface 30 </ b> Sb that contacts the conductor 220. The dynamic friction coefficient of each of the first contact surface 30Sa and the second contact surface 30Sb is 0 when measured by a dynamic friction coefficient test method based on JIS K7125 (a load of 200 g is applied to a rolled copper foil having a thickness of 25 μm as a sliding piece). It is preferable that it is 0.5 or more and 1.0 or less.

  Further, the tensile elastic modulus of the inner layer having the first contact surface 30Sa in the first resin layer 30A and the inner layer having the second contact surface 30Sb in the second resin layer 30B is preferably 300 MPa or more, and more than 800 MPa. It is more preferable that These inner layers correspond to the “surface layer” of the resin layer 30 included in the insulating film 100 described above.

  The plurality of conductors 220 are embedded in the covering member 210. Specifically, the plurality of conductors 220 are sandwiched between the first resin layer 30A and the second resin layer 30B. In the present embodiment, it is assumed that about 80 conductors 220 (width 0.3 mm, thickness 0.035 mm) are arranged at a pitch of 0.5 mm, but the present invention is not limited to this. The size and number of the plurality of conductors 220 can be appropriately changed according to the use of the flat cable 200.

(Function and effect)
(1) The insulating film 100 according to this embodiment includes a support layer 10 and a resin layer 30. The resin layer 30 contains a polyolefin resin. The dynamic friction coefficient of the surface of the resin layer 30 is 0.5 or more and 1.0 or less when measured according to JISK7125.

  Therefore, when the first and second end portions 210A and 210B of the covering member 210 are pulled out, the sliding of the first end portion 210A and the second end portion 210B with respect to the plurality of conductors 220 can be improved. For this reason, it is possible to prevent the plurality of exposed conductors 220 from extending or shifting.

  (2) The tensile elastic modulus of the surface layer constituting the surface 30S of the resin layer 30 is preferably 300 MPa or more, and more preferably 800 MPa or more.

  Thereby, it is possible to suppress a part of the resin layer 30 from adhering to the exposed conductor 220.

(Other embodiments)
Although the present invention has been described according to the above-described embodiments, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  (A) In the said embodiment, although the insulating film 100 was provided with the anchor coat layer 20, it is not restricted to this. If the adhesiveness between the support layer 10 and the resin layer 30 is good, the insulating film 100 may not include the anchor coat layer 20.

(B) Although the case where the resin layer 30 has a single layer structure has been mainly described in the above embodiment, the resin layer 30 may have a multilayer structure.
For example, as shown in FIG. 4, the insulating film 100 may include a resin layer 40 having a three-layer structure. The resin layer 40 includes a surface layer 41, an intermediate layer 42, and an inner layer 43. The surface layer 41 is a layer farthest from the support layer 10 in the resin layer 40. The surface layer 41 has the same configuration and characteristics as the resin layer 30 according to the embodiment. That is, the surface layer 41 contains a polyolefin resin, and the dynamic friction coefficient of the surface 41S of the surface layer 41 is 0.5 or more and 1.0 or less when measured by a dynamic friction coefficient test method based on JIS K7125. Is preferred. Further, the tensile elastic modulus of the surface layer 41 is preferably 300 MPa or more, and more preferably 800 MPa or more. Note that a flame retardant and a filler component may not be added to the surface layer 41 in consideration of appearance quality and handling at the time of manufacture (for example, at the time of extrusion molding). The intermediate layer 42 is disposed between the surface layer 41 and the inner layer 43. The intermediate layer 42 may be made of a urethane resin or a polyester resin other than polyolefin. A flame retardant may be added to the intermediate layer 42 in order to ensure the flame retardancy of the insulating film 100. The inner layer 43 is a layer closest to the support layer 10 in the resin layer 40. In FIG. 4, the case where the inner layer 43 is in contact with the anchor coat layer 20 is illustrated, but the inner layer 43 may be in contact with the support layer 10. The inner layer 43 may be made of a urethane resin or a polyester resin other than the polyolefin resin. The resin used for the inner layer 43 can be selected in consideration of the adhesion with the support layer 10 and the anchor coat layer 20.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.

(Production of Examples 1 to 9 and Comparative Examples 1 to 3)
First, a film-like resin layer was formed by melt extrusion using the resins A to M shown in Table 2. As shown in Table 1, the resin layer has a one-layer structure in Examples 1 and 2 and Comparative Example 1, and has a two-layer structure in Examples 3 to 5 and Comparative Example 2, and Examples 6 to 9 and Comparative Example Example 3 has a three-layer structure. In Table 1, the first layer constitutes the “surface layer” of the resin layer, and the elastic modulus of the resin constituting the “surface layer” is described. In addition, the structure of each of the resin A to the resin M is shown in Table 2, and the structure of the additive in Table 2 is shown in Table 3. In Tables 2 and 3, parts by mass are displayed.

  Next, on a PET film (Toray; Lumirror P60, thickness 12 μm) as a support layer, a two-component urethane adhesive (Mitsui Chemicals; Takelac A-310: Takenate A-3 = 10) as an anchor coat layer. 1) was applied to a thickness of 3 μm.

  Next, after placing the resin layer on the anchor coat layer and laminating at 60 ° C., curing was performed at 40 ° C. for 3 days to produce an insulating film.

  Next, 80 soft copper foils (width 0.3 mm, thickness 0.035 mm) were arranged at a pitch of 0.5 mm on the resin layer of one insulating film.

  Next, 80 soft copper foils were covered with another insulating film.

  Next, the two insulating films were sandwiched by a laminator at 150 ° C., whereby the resin layers of the two insulating films were thermally fused. Thereby, the coating | covering material which coat | covers an annealed copper foil was formed, and the 30 mm long flat cable was completed.

(Measurement of dynamic friction coefficient of resin layer)
In the insulating films according to Examples 1 to 9 and Comparative Examples 1 to 3, the dynamic friction coefficient of the surface of the resin layer was measured by the following method based on JIS K7125. Specifically, a rolled copper foil having a thickness of 25 μm is placed on the surface of the resin layer, and the dynamic friction coefficient is calculated based on the dynamic friction force when the surface is slid in a state where a load of 200 g is uniformly applied to the rolled copper foil. Calculated. The measurement results of the dynamic friction coefficient are shown in Table 1.

(Evaluation of drawability of coating material)
The state of the annealed copper foil when the coating material was pulled out from both ends of the flat cables according to Examples 1 to 9 and Comparative Examples 1 to 3 was observed. Specifically, after inserting a blade into the 2 mm portions of both ends of the flat cable and forming a cut only in the covering material, the covering material having a width of 2 mm is drawn from 80 soft copper foils, and the shape of the 80 soft copper foils, The arrangement and appearance were observed.

  (A) As shown in Table 1, in Comparative Example 1 and Comparative Example 2 manufactured using an insulating film having a dynamic friction coefficient larger than 1.0, the soft copper foil extended in the direction in which the coating material was pulled out. This is because the dynamic friction coefficient on the surface of the resin layer is too large and the covering material cannot be pulled out smoothly.

  On the other hand, as shown in Table 1, in the comparative example 3 produced using the insulating film with a dynamic friction coefficient smaller than 0.5, arrangement | positioning of the annealed copper foil was shifted | deviated. This is because the dynamic friction coefficient on the surface of the resin layer was too small to hold the soft copper foil with the coating material.

  From the above, it was found that the dynamic friction coefficient on the surface of the resin layer is preferably 0.5 or more and 1.0 or less.

  (B) Moreover, as shown in Table 1, although the dynamic friction coefficient is 0.5 or more and 1.0 or less, in Example 9 where the elastic modulus of the surface layer of the resin layer is smaller than 300 MPa, the surface of the annealed copper foil Resin residue was observed. This is because the elastic modulus of the surface layer is too low and a part of the surface layer is peeled off by friction with the soft copper foil during drawing.

  From this, it was found that the elastic modulus of the surface layer of the resin layer is preferably 300 MPa or more.

(Production of Examples 10 to 14)
Using the resin shown in Table 5 or Table 2, a film-like resin layer was formed by a melt extrusion method. As shown in Table 4, the resin layer has a one-layer structure in Example 14, a two-layer structure in Examples 10 to 11, and a three-layer structure in Examples 12 to 13. In Table 4, the first layer constitutes the “surface layer” of the resin layer, and the elastic modulus of the resin constituting the “surface layer” is described. In addition, Table 5 shows the configuration of each of the resin N to the resin S. Table 5 shows parts by mass.

Next, by the same material and method as in Examples 1 to 9 and Comparative Examples 1 to 3, the resin layer is laminated on a support layer provided with an anchor coat layer to produce an insulating film, and then the two insulating films A flat cable was prepared by covering 80 annealed copper foils.

Moreover, the measurement of the dynamic friction coefficient of the resin layer and the evaluation of the drawability of the coating material were performed in the same manner as in the Examples and Comparative Examples, and the results are also shown in Table 4.

As shown in Tables 4 and 5, in Examples 10 to 14, the surface layer of the resin layer does not contain a lubricant. However, the coefficient of dynamic friction was 0.5 or more and 1.0 or less depending on the type of resin, and as a result, the evaluation of the drawability of the coating material was good, and there was no elongation deviation of the soft copper foil. Further, the tensile modulus of the surface layer was all 300 MPa or more, and no resin residue was observed on the surface of the annealed copper foil.

（注）本添加剤の成分は表３に示されたものである。

(Note) The ingredients of this additive are those shown in Table 3.

DESCRIPTION OF SYMBOLS 100 ... Insulating film 10 ... Support layer 20 ... Anchor coat layer 30 ... Resin layer 200 ... Flat cable 210 ... Cover member 210A ... 1st end part 210B ... 2nd end part 220 ... Conductor

Claims (5)

A resin layer having a surface layer containing a polyolefin-based resin;
A support layer for supporting the resin layer;
With
The dynamic friction coefficient of the surface of the resin layer is 0.5 or more and 1.0 or less when measured according to JISK7125.
Insulation film for flat cable. The surface layer has a tensile modulus of elasticity of 300 MPa or more.
The insulating film for flat cables according to claim 1. The surface layer contains a lubricant composed of a fatty acid ester or a fatty acid amide,
The content of the lubricant in the surface layer is 0.01 parts by mass or more and 1.0 parts by mass or less with respect to 100 parts by mass of the polyolefin resin.
The insulating film for flat cables according to claim 1 or 2. The resin layer has a thickness of 20 μm or more and 100 μm or less.
The insulating film for flat cables in any one of Claims 1 thru | or 3. A first resin layer having a first surface layer containing a polyolefin-based resin;
A first support layer for supporting the first resin layer;
A second resin layer comprising a polyolefin resin and having a second surface layer thermally fused to the first surface layer;
A second support layer for supporting the second resin layer;
A conductor embedded between the first resin layer and the second resin layer;
With
The dynamic friction coefficient of the first contact surface in contact with the conductor in the first surface layer and the dynamic friction coefficient of the second contact surface in contact with the conductor in the second surface layer are 0 when measured according to JISK7125. .5 or more and 1.0 or less,
Flat cable.

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