JPH09185912A - Flat cable and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low cost flat cable which is easily flexible, can save space, maintains insulation performance for a long period and displays an excellent cable function even if it is used at a place exposed to high temperature and high humidity atmosphere and even if it is used in bending. SOLUTION: A conductor 1 is sandwiched by a film having an adhesive layer 2, particularly hot melt adhesive, on one side faces of insulation layers 3, 5, and a film having a primer layer 4 on one side faces of the insulation layers 3, 5 so that the adhesive layer 2 and a primer layer 4 touch each other. One side insulation layer 3 exists on one face of the conductor 1 in the lengthwise direction via the adhesive layer 2, and the other insulation layer 5 exists on the opposite face via the primer layer 4 of 0.01 to 3μm thick.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat cable having a conductor covered with an electrically insulating synthetic resin and a method for manufacturing the flat cable.

[0002]

2. Description of the Related Art Conventionally, in electric wire mounting technology, a conductor having a flat cross section and a plurality of copper conductors and the like are sandwiched from both sides with an electrically insulating synthetic resin film. Coated flat cables are widely used because they streamline wiring work. For example, an undercarpet electric wire for arranging an electric wire under a carpet so that wiring connecting each electric device in a building is not exposed on the floor, an electric wire for a device used as an internal wiring of an electronic electric device such as an OA device, It is also used as an electric wire or the like for electrically connecting the operation part of a driver's seat of an automobile and various electric devices. Since the flat cable is lightweight and easy to install, its application is being studied especially in the automobile industry in order to improve the efficiency of wiring work and the weight of the vehicle body. For example, when it is used for a door portion of an automobile, it is necessary to provide a curved portion or a bent portion in a circuit pattern according to the use place in order to facilitate wiring in a narrow place. In addition, when it is necessary to add a circuit pattern due to the addition of electric equipment, a plurality of flat cables may be stacked and used.
Furthermore, when it rains or when the vehicle is washed, water enters the interior of the door through the gaps between the windows to create a high-humidity atmosphere inside the door, and when the vehicle body is subsequently heated by direct sunlight, it becomes a high-temperature, high-humidity atmosphere. Therefore, the electric wire mounted inside the door will be exposed to the above-mentioned severe conditions for a long time with the curved part, the bent part, and the branch line, and will be exposed to such an atmosphere for a long time. However, it is required that the electrical insulation performance does not significantly decrease.

For this reason, conventional flat cables have been manufactured by using a laminate tape in which an adhesive layer is laminated on an insulating film and sandwiching the conductor from both sides. That is, in order to fully exhibit the electric insulation performance even under the severe conditions of high temperature and high humidity atmosphere as described above, the conductors are sandwiched with the insulating film laminated with the adhesive on both sides, It was necessary to firmly bond the adhesives to each other by bonding them together, and to completely surround the conductors to insulate the individual circuits. However, since both surfaces of the conductor are bonded by the electric insulating film laminated with the adhesive, there is a problem that the thickness of the flat cable itself obtained by that is increased and the bending performance is deteriorated. Also, the adhesives used there, especially hot melt adhesives, are expensive,
The flat cable obtained by using it also becomes expensive.

Japanese Patent Publication No. 7-120492 discloses an insulating film (insulating layer (base material) / thermosetting adhesive layer / thermoplastic adhesive layer) and an insulating layer (base material) / thermosetting property. A flat cable formed by sandwiching a flat conductor with an insulating film formed of an adhesive layer has been exemplified and proposed. In the case of this flat cable, thermosetting,
Although there are differences in the resin called thermoplasticity, since the adhesives are adhered to each other, it is necessary to increase the thickness of each adhesive in order to secure the adhesive force. Therefore, the thickness of the obtained flat cable also increases in proportion to the thickness of each adhesive layer, which leads to a decrease in bending performance, and both the thermosetting adhesive and the thermoplastic adhesive are expensive. The traditional problem of expensive cables has not been solved.

The object of the present invention is to maintain the insulation performance for a long period of time even if the flat cable is used in a place exposed to a high temperature and high humidity atmosphere, or even when it is bent and used. To provide a flat cable with reduced thickness at low cost.

[0006]

As a result of various investigations by the present inventors in order to achieve the above-mentioned object, as a result, instead of providing an adhesive layer on one insulating film, a base treatment agent (primer for improving adhesion) is used. It was discovered that the thickness of the obtained flat cable can be reduced by providing a layer) without lowering the adhesiveness between the insulating films, and the present invention has been completed. That is, the present invention is as follows. (1) In a flat cable in which a conductor is sandwiched between insulating layers, one insulating layer is present on one surface in the longitudinal direction of the conductor via an adhesive layer, and the other insulating surface is provided on the surface facing the insulating layer. A flat cable in which the layers are present via a primer layer having a thickness of 0.01 to 3 μm. (2) The flat cable according to (1) above, wherein the adhesive layer is a layer of a hot melt adhesive. (3) The flat cable according to (2), wherein the hot melt adhesive is a polyolefin adhesive or a polyester adhesive. (4) The flat cable as described in (1) above, wherein the primer layer is a urethane primer or organic titanium primer layer. (5) The flat cable according to (1) above, wherein the adhesive layer is a polyolefin adhesive layer, and the primer layer is a urethane primer layer or an organic titanium primer layer. (6) The adhesive layer is a polyolefin adhesive layer, and the primer layer is a urethane primer layer (5)
The flat cable described. (7) The flat cable according to (1) above, wherein the adhesive layer is a polyester adhesive layer and the primer layer is a urethane primer layer. (8) The flat cable as described in (1) above, which has an intermediate layer between the insulating layer and the adhesive layer facing the primer layer with the conductor interposed therebetween. (9) A step of sandwiching a conductor between a film having an adhesive layer on one surface of an insulating layer and a film having a primer layer on one surface of an insulating layer so that the adhesive layer and the primer layer are in contact with each other Flat cable manufacturing method. (10) The method for producing a flat cable according to (9) above, wherein the adhesive layer is a hot melt adhesive layer. (11) The method for producing a flat cable according to (10) above, wherein the hot melt adhesive is a polyolefin adhesive or a polyester adhesive. (12) The method for producing a flat cable according to (9) above, wherein the primer layer is a urethane primer or organic titanium primer layer. (13) The method for producing a flat cable according to (9) above, wherein the adhesive layer is a polyolefin adhesive layer, and the primer layer is a urethane primer or organic titanium primer layer. (14) The adhesive layer is a polyolefin adhesive layer and the primer layer is a urethane primer layer.
3) The method for producing a flat cable as described above. (15) The adhesive layer is a polyester adhesive layer, and the primer layer is a urethane primer layer (9)
The manufacturing method of the described flat cable.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of the configuration of the flat cable of the present invention. In the figure, a conductor 1 is a flat cable sandwiched between insulating layers 3 and 5, and one insulating layer 3 is present on one surface in the longitudinal direction of the conductor 1 via an adhesive layer 2, The other insulating layer 5 is present on the opposite surface via the primer layer 4.

Examples of the conductor 1 include bare copper, tin-plated copper, and silver, and foil-shaped or rectangular-shaped conductors thereof are used.

Although the thickness of the conductor is not particularly limited, it is usually 0.065 to 0.2 mm, preferably 0.08 to 0 from the viewpoints of rigidity, current capacity, securing a surface area for the purpose of heat dissipation of the wiring pattern, and the like. It is 0.15 mm.

The synthetic resins used as the insulating layers 3 and 5 are not particularly limited, but those having heat resistance, tensile strength and water resistance required for a flat cable are preferably used. . Examples of such synthetic resin include polyester such as polyethylene terephthalate and polybutylene terephthalate, polyamide such as nylon and aramid, polyolefin such as polyethylene and polypropylene, polyvinyl chloride, polyimide, polyarylate, polyphenyl sulfide, polyether sulfone, Examples thereof include polyether ether ketone and polyether imide. Among them, polyethylene terephthalate is preferable in terms of heat resistance and flexibility. The types of insulating synthetic resin forming the insulating layers 3 and 5 are the insulating layer 3,
5 may be the same type, or different types of resins may be used.

The thickness of the insulating layer is not particularly limited, and is appropriately selected depending on the thickness of the conductor, desired withstand voltage characteristics, flexibility and durability. It is usually selected from the range of 10 to 300 μm, preferably 25 to 200 μm.

The insulating layer contains an inorganic filler, an antioxidant,
Known additives such as a copper damage inhibitor, an ultraviolet absorber, a flame retardant, and a flame retardant aid may be blended.

As the adhesive used in the present invention, a known adhesive can be used and is not particularly limited as long as it adheres to the primer layer. For example, it has electric insulation and has a lower melting point and / or lower softening point than the resin used for the insulating layer,
It may be a resin (adhesive) capable of embedding a conductor in the adhesive layer at the time of manufacturing or flowing into the periphery of the conductor to prevent or fix contact with another adjacent conductor. Specifically, a polyolefin adhesive and / or a polyester adhesive is preferable, and a hot melt type adhesive is particularly preferable.

Examples of the above-mentioned polyolefin-based adhesive include high-density polyethylene (HDPE), low-density polyethylene (LDPE) and linear low-density polyethylene (LL).
DPE), ultra low density polyethylene, polypropylene (P
P) and resins such as copolymers thereof, unsaturated carboxylic acids thereof (acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, citraconic acid, etc.), or acid anhydrides (maleic anhydride). Graft modified products with acid, itaconic anhydride, citraconic anhydride, etc. can be used. In addition, ethylene-vinyl acetate (EV
A) Copolymer, ethylene-ethyl acrylate (EEA)
Copolymer, ethylene-methacrylic acid (EMAA) copolymer, ethylene-vinyl acetate glycidyl methacrylic acid (E
-VA-GMA) copolymers and the like, and resins obtained by graft-modifying these resins with alkoxysilane,
Ionomer (ethylene-metal acrylate copolymer, ethylene-methacrylate copolymer, etc.) can be used. Preferred are graft modified products with acid anhydrides (maleic anhydride, itaconic anhydride, citraconic anhydride, etc.).

The saturated copolymerized polyester hot melt adhesive is an acid component such as an aromatic dicarboxylic acid such as terephthalic acid or isophthalic acid, an aliphatic carboxylic acid such as adipic acid or sebacic acid, and ethylene glycol as a diol component. , 1,4-butanediol, diethylene glycol, neopentyl glycol and the like, each of which is polycondensed in combination of one or more. Moreover, you may mix | blend an antioxidant and a copper damage inhibitor as needed.

The saturated copolymerized polyester hot melt adhesive used in the present invention has a glass transition point (Tg) of 40.
Preferably, the softening point is about 70 to 70 ° C and the softening point is about 130 to 160 ° C.

Antioxidants added to the adhesive include
2,6-di-tert-butyl-4-methylphenol,
2,6-di-tert-butyl-4-ethylphenol,
4,4'-thiobis- (6-tert-butyl-3-methylphenol), 4,4'-thiobis- (6-tert-butyl-o-cresol), tetrakis- [methylene-3-
(3 ', 5'-di-tert-butyl-4'-hydroxyphenylpropionate)] A phenolic antioxidant such as methane is used as a copper damage inhibitor, and 1,2,3-benzotriazole, 3 -(N-salicyloyl) amino-1,
Benzotriazole-based copper damage inhibitors such as 2,4-triazole are preferred. Also, if necessary, the adhesive
Flame retardants such as antimony oxide, decabromodiphenyl ether, red phosphorus, aluminum hydroxide and magnesium hydroxide, colorants and the like may be appropriately mixed.

Other known additives such as tackifiers and stabilizers may be added to the adhesive.

The thickness of the adhesive layer may be appropriately selected according to the thickness of the conductor 1, but is usually selected in the range of 1 to 300 μm, preferably 30 to 200 μm.

The primer layer 4 provided on one surface of the insulating layer 5 is preferably one that has good adhesion to the insulating layer 5 and the adhesive layer 2, and has water resistance, heat resistance, and withstand voltage characteristics. Used for. Examples of the primer include a polyurethane-based primer, an organic titanium-based primer, and a silane-modified polyolefin-based primer. Examples of the polyurethane-based primer include a polyurethane-based (isocyanate-based) primer having an active isocyanate (NCO) group, and examples thereof include dibasic acid components (phthalic acid, terephthalic acid, adipic acid, etc.) and glycols (ethylene glycol, triglyceride). Copolymers of ethylene glycol, neopentyl glycol, 1,4-butanediol, etc.) and polyester polyols such as polycaprolactone, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenylmethane-4,4 ′
A polyfunctional isocyanate such as diisocyanate, polymethylene polyphenyl diisocyanate, hexamethylene diisocyanate, hexahydrometa xylylene diisocyanate, triphenylmethane-p, p ′, p ″ -triisocyanate, polyisocyanate and / or a mixture thereof, Examples include those containing a modified product as a main component. Further, the polyurethane-based primer may be either one-component or two-component curing type. Examples of the organotitanium-based primer include organotitanium-based primers having an alkoxyl group, such as Ti (OR ¹ ) (OR ² )
(OR ³ ) (OR ⁴ ) [wherein R ^{1 to} R ⁴ may be the same or different and each represents an alkyl group or an allyl group having 1 to 27, preferably 3 to 19 carbon atoms] Alkyl titanate. Specifically, tetra-i-propyl titanate (TPT), tetra-n-butyl titanate (TBT), tetra (2-ethylhexyl) titanate (TOT), tetrastearyl titanate (TST), di-i-propoxy bis. (Acetylacetonato) titanium (TAA) etc. are mentioned. These may be used alone or in combination of two or more. Since the -OR group in the molecule of the above-mentioned alkyl titanate is dissociated by hydrolysis, the organotitanium-based primer becomes a colorless, transparent and very thin polymer titanium oxide film having a structure similar to titanium oxide. Examples of the silane-modified polyolefin-based primer include ethylene-ethyl acrylate (EEA) and ethylene-vinyl acrylate (EV
Examples thereof include copolymers obtained by graft-polymerizing A) and the like with alkoxysilanes such as methoxysilane and butoxysilane.

The thickness of the primer layer is 0.01 to 3 μm.
m, preferably 0.1 to 1 μm. When the thickness of the primer layer is less than 0.01 μm, there is a lack of wettability of the primer solution to the adhered surface, lack of the primer, unevenness of the adhered surface, stain on the adhered surface, etc. Since the primer is not applied, or uneven coating occurs, the initial adhesive strength is insufficient and the adhesive strength is significantly reduced after use under the severe conditions described above, which is not preferable in terms of insulation performance of the flat cable. On the other hand, when the thickness is more than 3 μm, the adhesive strength is remarkably reduced due to cohesive failure of the primer layer itself due to poor drying of the primer layer or insufficient cohesive force, and the bending performance is also deteriorated, which causes a problem in the insulation performance of the flat cable. There is.

As a combination with the adhesive layer 2 and the primer layer 4, a polyolefin-based adhesive and a urethane-based primer or an organotitanium-based primer, or a polyester-based adhesive and a urethane-based primer are used because of their adhesiveness. Preferred, and withstand voltage characteristics,
It is also preferable in terms of heat resistance and water resistance. In particular, a combination of a polyolefin adhesive and a urethane primer is preferable.

In the present invention, in order to further improve the adhesiveness between the insulating layer 3 and the adhesive layer 2, an intermediate layer may be provided between the layers. As the material used for the intermediate layer, the same material as the primer can be used. The thickness of the intermediate layer is 0.5.
It is preferably about 30 μm.

The flat cable manufacturing method of the present invention is
A conductor having a film having an adhesive layer on one surface of the insulating layer and a film having a primer layer on one surface of the insulating layer, and sandwiching the adhesive layer so that the adhesive layer and the primer layer are in contact with each other. And

The film having the adhesive layer on one surface of the insulating layer may be produced by a method known per se, for example, a gravure roll method, a direct roll method, a dip roll method,
An extrusion method and the like can be mentioned. Further, a primer layer can be provided between the layers, if necessary.

The film having a primer layer on one surface of the insulating layer can be obtained, for example, by applying a primer diluted with a solvent on the insulating layer by a known method and drying. The drying temperature is usually 30 to 150 ° C, preferably 80 to 12
The drying time at 0 ° C. is usually 30 seconds to 10 minutes, preferably 2 to 5 minutes. Further, it is desirable to carry out curing at 20 to 50 ° C., preferably 30 to 40 ° C. for 1 to 168 hours, preferably 2 to 48 hours.

Placing and bonding a conductor between the film having an adhesive layer on one surface of the insulating layer obtained as described above and the film having a primer layer on one surface of the insulating layer. A flat cable is obtained by.

For the adhesion, conventional methods such as hot pressing and laminating can be applied. As the adhesion conditions, for example, in the case of hot pressing, the adhesion temperature is usually 100 to 250 ° C., preferably 1
50 to 200 ° C., adhesion time is usually 15 seconds to 5 minutes, preferably 1 to 2 minutes, adhesion pressure is usually 0.5 to 20 k
g / cm, preferably 2 to 10 kg / cm. In the case of laminating, the bonding temperature is usually 100 to 25.
0 ° C., preferably 150 to 200 ° C., the adhesive pressure is usually 4 to 13 kg / cm, preferably 6 to 10 kg / cm,
The adhesion speed is usually 0.5 to 5 m / min, preferably 0.5.
~ 4 m / min. Within the above-mentioned adhesion conditions, there is no problem that the flow of the adhesive between the conductors is reduced, the adhesion between the primer layer and the adhesive layer may be poor, or the insulation may be poor. It does not cause problems such as protrusion or defective appearance after molding.

[0029]

EXAMPLES The present invention will be described more specifically below based on examples, but the present invention is not limited to these examples.

Example 1 Five strips of a copper conductor having a width of 3.0 mm and a conductor spacing of 1 mm and a thickness of 8
Polyethylene terephthalate (P having a thickness of 50 μm) having a 0 μm polyolefin hot melt adhesive (maleic acid modified product of linear low-density polyethylene) layer on one surface.
ET) was laid on the adhesive layer surface of the film and temporarily adhered to obtain a linear adhesive film with 4 mm aligned on one side of the ear. In addition, a two-component curing type polyurethane-based primer (polyester polyol / modified MDI) was applied to 50 μm of an electrical PET film by a direct roll coater, and then 100
Dry for 2 minutes at ℃, primer layer (thickness: 0.02μ
A PET film having m) was obtained. The primer layer surface of the PET film was aligned with the adhesive layer surface of the adhesive film, and a flat cable was obtained by laminating at 180 ° C. × 0.5 m / min × 9 kg / cm.

Example 2 Example 1 except that the thickness of the primer layer was 0.1 μm.
A flat cable was obtained in the same manner as in.

Example 3 Example 1 except that the thickness of the primer layer was 1.0 μm.
A flat cable was obtained in the same manner as in.

Example 4 Example 1 except that the thickness of the primer layer was 2.0 μm.
A flat cable was obtained in the same manner as in.

Example 5 Example 1 except that the thickness of the primer layer was 2.5 μm.
A flat cable was obtained in the same manner as in.

Comparative Example 1 A flat cable was obtained in the same manner as in Example 1 except that the primer layer was not used.

Comparative Example 2 A flat cable was obtained in the same manner as in Example 1 except that the thickness of the primer layer was 0.005 μm.

Comparative Example 3 A flat cable was obtained in the same manner as in Example 1 except that the thickness of the primer layer was 4 μm.

Comparative Example 4 A flat cable was obtained in the same manner as in Example 1 except that the thickness of the primer layer was 10.0 μm.

Example 6 As a primer, an organotitanium-based primer (TPT, T
A mixture of OT and TST) was used, and a flat cable was obtained in the same manner as in Example 1 except that the thickness of the primer layer was 0.015 μm.

Example 7 A flat cable was obtained in the same manner as in Example 2 except that the same organotitanium-based primer as used in Example 6 was used as the primer.

Example 8 A flat cable was obtained in the same manner as in Example 3 except that the same organotitanium-based primer as used in Example 6 was used as the primer.

Example 9 A flat cable was obtained in the same manner as in Example 4 except that the same organotitanium-based primer as used in Example 6 was used as the primer.

Example 10 The same organotitanium-based primer as used in Example 6 was used as the primer, and the thickness of the primer layer was 2.8 μm.
A flat cable was obtained in the same manner as in Example 1 except that m was set.

Comparative Example 5 A flat cable was obtained in the same manner as in Comparative Example 2 except that the same organotitanium-based primer as used in Example 6 was used as the primer.

Comparative Example 6 A flat cable was obtained in the same manner as in Example 1 except that the same organotitanium-based primer as used in Example 6 was used as the primer and the thickness of the primer layer was 5 μm.

Comparative Example 7 A flat cable was obtained in the same manner as in Comparative Example 4 except that the same organotitanium-based primer as used in Example 6 was used as the primer.

Example 11 A polyester-based adhesive (saturated copolymerized polyester-based hot melt adhesive consisting of terephthalic acid and isophthalic acid as acid components and ethylene glycol and 4-butanediol as diol components) was used as the adhesive. A flat cable was obtained in the same manner as in Example 6.

Example 12 A flat cable was obtained in the same manner as in Example 2 except that the same polyester-based adhesive as used in Example 11 was used as the adhesive.

Example 13 A flat cable was obtained in the same manner as in Example 3 except that the same polyester-based adhesive as used in Example 11 was used as the adhesive.

Example 14 A flat cable was obtained in the same manner as in Example 4 except that the same polyester-based adhesive as used in Example 11 was used as the adhesive.

Example 15 A flat cable was obtained in the same manner as in Example 5 except that the same polyester-based adhesive as used in Example 11 was used as the adhesive.

Comparative Example 8 A flat cable was obtained in the same manner as in Example 11 except that the primer was not used.

Comparative Example 9 A flat cable was obtained in the same manner as in Comparative Example 2 except that the same polyester adhesive as that used in Example 11 was used as the adhesive.

Comparative Example 10 A flat cable was obtained in the same manner as in Comparative Example 6 except that the same polyester-based adhesive as that used in Example 11 was used as the adhesive.

Comparative Example 11 A flat cable was obtained in the same manner as in Comparative Example 4 except that the same polyester-based adhesive as used in Example 11 was used as the adhesive.

Comparative Example 12 100 parts by weight of a saturated polyester resin (manufactured by Unitika Ltd .; trade name UE-3221) was added to 35 parts by weight of methyl ethyl ketone, and 1 part by weight of a curing agent tolylene diisocyanate (TD).
I, manufactured by Nippon Polyurethane Industry Co., Ltd .; trade name Coronate L)
Was dissolved and diluted in 15 parts by weight of toluene, respectively, and these solutions were mixed to prepare a primer solution. A flat cable was prepared using this primer solution in the same manner as in Example 1 (thickness of primer layer: 5 μm).

Comparative Example 13 A flat cable was obtained in the same manner as in Comparative Example 12 except that the same polyester adhesive as that used in Example 11 was used as the adhesive.

Using the flat cable obtained as described above as a test piece, the following water resistance, heat resistance test, and bending heating test were carried out, and the appearance,
Peeling and withstand voltage tests were conducted.

[Water Resistance Test] The above test piece was immersed in hot water at 80 ° C., taken out 168 hours later, and after observing the appearance,
The following peel test and withstand voltage test were performed. Here, the case where there is no abnormal appearance was evaluated as ◯. Withstand Voltage Test After the center portion 30 cm of the above test piece was immersed in 5% salt water for 1 hour, a DC power supply was used and a voltage was applied in salt water for 1 kV × 1 minute. Here, those that did not cause dielectric breakdown were rated as ◯ (pass) and those that caused dielectric breakdown were rated as x (fail). Peel test Peel strength is measured by Tensilon tensile tester (UCT-500,
180 degree peeling (electrically insulating resin layer side having a primer), peeling speed 50m
It was measured in m / min.

[Heat Resistance Test] After leaving the above test piece in a gear oven at 135 ° C. for 168 hours, the appearance was observed,
A withstand voltage test and a peeling test were conducted in the same manner as the water resistance test.

[Bending Heating Test] The test piece was folded in half at the center (completely bent by 180 °) and left as it was in a gear oven at 90 ° C. for 120 hours. This was taken out and restored at room temperature, and then the appearance was observed. Further, a withstand voltage test was conducted in the same manner as above.

The results are shown in Tables 1 to 4. The flat cable of the example was good in all of the initial, heat resistance test, water resistance test, and bending heating test results. On the other hand, in Comparative Examples 1, 2, 5, 8, and 9, peeling of the insulating layer (PET), which is considered to be caused by the lack of glue of the primer and uneven coating, was observed in the results of the water resistance test and the bending heating test. And a withstand voltage defect occurred. Comparative Examples 3, 4, 6,
In Nos. 7, 10 and 11, peeling of the insulating film occurred mainly at both ears of the bent portion of the test piece in the bending heating test. Further, in Comparative Examples 12 and 13, due to the influence of the compatibility between the thermosetting adhesive used as the primer and the polyolefin-based adhesive and the polyester adhesive and the effect of hydrolysis of the primer layer, the insulation layer peeled or The adhesive strength was remarkably reduced, the insulating film was peeled off from the bent ear of the test piece in the bending heating test, and the withstand voltage was poor.

[0063]

[Table 1]

[0064]

[Table 2]

[0065]

[Table 3]

[0066]

[Table 4]

[0067]

According to the present invention, it is possible to reduce the thickness of the adhesive layer of the cable, thus improving the flexibility and saving the space. Further, such a flat cable is inexpensive. Can be provided. Further, since the flat cable itself has excellent water resistance and heat resistance, it can be used outdoors, where it has not been conventionally applicable, or in places with high temperature and high humidity. Further, since the weight is reduced, its application can be expanded.

[Brief description of the drawings]

FIG. 1 is a sectional view of a flat cable showing an embodiment of the present invention.

[Explanation of symbols]

 1 conductor 2 adhesive layer 3 insulating layer 4 primer layer 5 insulating layer

Claims (15)

[Claims] 1. A flat cable in which a conductor is sandwiched between insulating layers, wherein one insulating layer is present on one surface in the longitudinal direction of the conductor via an adhesive layer and the other surface is opposite to the insulating layer. The flat cable in which the insulating layer is present via a primer layer having a thickness of 0.01 to 3 μm. 2. The flat cable according to claim 1, wherein the adhesive layer is a layer of hot melt adhesive. 3. The flat cable according to claim 2, wherein the hot melt adhesive is a polyolefin adhesive or a polyester adhesive. 4. The flat cable according to claim 1, wherein the primer layer is a layer of a urethane-based primer or an organic titanium-based primer. 5. The flat cable according to claim 1, wherein the adhesive layer is a polyolefin adhesive layer and the primer layer is a urethane primer or organic titanium primer layer. 6. The flat cable according to claim 5, wherein the adhesive layer is a polyolefin adhesive layer and the primer layer is a urethane primer layer. 7. The flat cable according to claim 1, wherein the adhesive layer is a polyester adhesive layer and the primer layer is a urethane primer layer. 8. The flat cable according to claim 1, further comprising an intermediate layer between the insulating layer and the adhesive layer facing the primer layer with the conductor interposed therebetween. 9. A step of sandwiching a conductor between a film having an adhesive layer on one surface of an insulating layer and a film having a primer layer on one surface of an insulating layer so that the adhesive layer and the primer layer are in contact with each other. Of manufacturing a flat cable having a. 10. The method of manufacturing a flat cable according to claim 9, wherein the adhesive layer is a layer of hot melt adhesive. 11. The hot melt adhesive is a polyolefin adhesive or a polyester adhesive.
The manufacturing method of the flat cable of 0. 12. The method for producing a flat cable according to claim 9, wherein the primer layer is a layer of a urethane-based primer or an organic titanium-based primer. 13. The method of manufacturing a flat cable according to claim 9, wherein the adhesive layer is a polyolefin adhesive layer, and the primer layer is a urethane primer or organic titanium primer layer. 14. The method of manufacturing a flat cable according to claim 13, wherein the adhesive layer is a polyolefin adhesive layer and the primer layer is a urethane primer layer. 15. The method of manufacturing a flat cable according to claim 9, wherein the adhesive layer is a polyester adhesive layer and the primer layer is a urethane primer layer.