JPH0749688Y2 - Shielded insulated wire - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a shielded insulated wire in which the end treatment of the shield layer is easy when cut to a desired length.

[Conventional technology]

As a shielded insulated wire, as shown in FIG.
In some cases, an insulating coating 32 is applied on top of which an annealed copper wire or a tin-plated annealed copper wire braid 33 is applied to form a shield layer 34, and an outer jacket 35 is formed on the outer periphery thereof.

As can be seen from the structure of this shielded insulated wire, the shielded insulated wire is cut to a desired length, and when it is connected to a device or a connector, the shield layer 34 at the terminal portion is peeled off to process the shielded insulated wire. Need to

From the above circumstances, in order to facilitate the end treatment of the shield layer 34, “for a plurality of insulating wire cores traveling in parallel, the shield layer (copper foil, aluminum foil, etc. is intermittently provided in the length direction. ) Is simultaneously advanced, and the tape is longitudinally formed along the length of the tape while the tape is cut so as to match the number of wire cores in the lengthwise direction. It is disclosed in the publication.

According to the above-mentioned publication, the shield layer is intermittently applied on the plastic tape, and therefore the terminal treatment can be easily performed by cutting the insulated wire at the portion where the shield layer is not present.

However, it is extremely difficult to accurately and intermittently bond the copper foil or the aluminum foil onto the plastic film, the productivity is poor, and there is a problem in terms of profitability.

On the other hand, Japanese Utility Model Laid-Open No. 60-193621 discloses "a technique for forming a coating shield layer for a signal line on a surface coated with a conductive paint".

Therefore, in the cable described in the above-mentioned publication, it is possible to form the intermittent shield layer with conductive paint.

However, conventional conductive paints have low conductivity, so
Even if it is used for the shield layer, a sufficient shield effect cannot be expected. For example, Japanese Patent Application Laid-Open No. 62-253 filed by the applicant of the present application
With the conductive paint described in Japanese Patent No. 675, the conductivity is not sufficient,
Insufficient as a paint for forming a shield layer (see the shield property test described later).

Under the above circumstances, the present invention provides a shielded electric wire covered with a plastic film, which is intermittently provided with the shield layer described in the above-mentioned publication, and the shield layer is a coating layer of a conductive paste made of the following conductive paint. The configuration made in was adopted.

Description "Resin mixture 10-25 containing 35-50% by weight of melamine resin, 20-35% by weight of polyester resin and 15-30% by weight of resol-type phenolic resin per 100 parts by weight of metallic copper powder.
A conductive coating composition comprising 0.1 part by weight, 0.1-2 parts by weight of a fatty acid or a metal salt of a fatty acid, and 0.5-4 parts by weight of a chelating agent. (See Japanese Patent Application No. 62-328095 (JP-A-1-67385)).

As the plastic film, it is possible to use a film such as polyethylene, polyester, polyimide, polyamide, etc. It is particularly desirable that it can withstand the heating temperature and its heating time in the step of curing the conductive coating, and that it can withstand the above curing conditions. As long as it is another plastic film, it is not particularly limited.

[Action]

In the present invention configured as described above, a plastic film having a shield layer coated with the conductive paste is continuously formed with high precision by a printing method using the conductive paste on the plastic film while providing a portion which is not applied intermittently. It is economical because it uses what can be manufactured.

Further, the terminal processing work can be performed by accurately cutting the portion where the conductive paste is not applied, and the attachment of the connector and the connection to the device become easy.

Furthermore, as a resin mixture, a resol type phenol resin is used, and a conductive coating material in which a chelating agent is dissolved is
Superior in conductivity to conventional ones. Therefore, the insulated wire according to the present invention has a high shielding effect.

By the way, it is considered that the improvement of the conductivity is largely contributed by the fact that the chelating agent prevents the metal copper powder from being oxidized. Generally, the oxide film is an insulator, and if the surface of the copper powder is oxidized, the film deteriorates the conduction between the copper powder,
The conductivity of the entire coated surface is reduced.

〔Example〕

 Next, an embodiment of the present invention will be described with reference to the drawings.

According to the present invention, a shielded polyester film 4 is obtained by coating a conductor 1 with a rubber or plastic insulator 2 and applying a conductive paste 3 on the outer periphery thereof while providing a portion 10 on which the paste is not applied intermittently. It is vertically attached, covered on the insulator 2, and an outer cover 5 is applied on the insulator 2 to form a shielded insulated wire.

Next, the portion 10 where the conductive paste 3 is not applied intermittently
The production of the polyester film with a shield 4 which is applied and cured while providing the above will be described below.

First, 100 parts by weight of dendritic metal copper powder having a particle size of 5 to 10 μm, 1 part by weight of potassium oleate, and triethanolamine 3.5.
Parts by weight, 9 parts by weight of butylated melamine resin, 7 parts by weight of polyester resin, 7 parts by weight of resol type phenolic resin are added, a little butyl cellosolve acetate is added as a solvent, and the mixture is kneaded with a triaxial roll for 20 minutes to be suitable. Adjust to a proper viscosity.

Next, this conductive paste 3 is supplied to a conductive paste kneading roll 6, and the homogenized conductive paste 3 is evenly spread by a group of intermediate rolls 7 to a final paste thickness of 30 μm. The conductive paste 3 is transferred to the printing roll 8 which is partially cut on the outer peripheral surface and whose surface is etched. Transferred conductive paste 3
Is transferred to the surface of the polyester film 4'running while being synchronized with the peripheral speed of the printing roll 8 and being pressed by the backup roll 9.

Polyester film 4 on which conductive paste 3 is transferred
Is then passed through a heating zone under curing conditions of 130 to 180 ° C. for 10 to 60 minutes to produce a polyester film with a shield 4.

[Shielding test]

Width of 2m on glass / epoxy resin substrate by screen printing using the above conductive paint (conductive paste 3)
Five conductive circuits of m, thickness 30 ± 5 μm, and length 100 mm were formed and heated at 150 ° C. for 30 minutes to cure the coating film. The volume resistivity of this coating film was measured and the conductivity of the coating film was evaluated. As a result, it was 1 × 10 ⁻⁴ Ω · cm, and there was no deterioration over time.

On the other hand, as a comparative example, the conductive paint described in Japanese Utility Model Publication No. 60-193621, that is, a resin mixture (melamine resin 20 to 60% by weight, and polyol and polyester resin or And alkyd resin 80-40
15% by weight of a resin mixture) and 1 to 8 parts by weight of a saturated fatty acid or an unsaturated resin acid or a metal salt thereof, and a conductive coating material kneaded in the same manner as described above. When a coating film was formed on a glass / epoxy resin substrate and its conductivity was evaluated, it was 1-6 × 10 ^-3.
Ω · cm, and the decrease was observed over time (Japanese Patent Laid-Open No.
(See Table 1 of 62-253675).

From the above comparison, it can be understood that the conductive paint according to the present invention is superior in conductivity as compared with the conventional example. Therefore, the shield layer using the conductive paint also has a high shielding effect.

〔effect〕

Since the present invention is configured as described above and uses the conductive paste intermittently transferred onto the plastic film, which can be continuously produced with high precision, the shielded insulated wire which can be easily terminated is economically manufactured. be able to.

Moreover, since the shield layer made of the conductive paste used is excellent in conductivity, it becomes a shielded insulated wire having good shielding characteristics.

[Brief description of drawings]

FIG. 1 is an explanatory view of a manufacturing process of a shielded insulated wire according to the present invention, FIG. 2 is a schematic view of an apparatus for applying a conductive paste to a plastic film, and FIG. 3 is a perspective view of a conventional example. The reference numerals in the drawings are as follows. 1 ... Conductor, 2 ... Insulator, 3 ... Conductive paste application part, 4 ... Shielded plastic film obtained by curing conductive paste, 4 '... Plastic film,
5 ... Coating, 6 ... Conductive paste kneading roll, 7 ...
Intermediate roll group, 8 ... Printing roll, 9 ... Backup roll, 10 ... Part not coated with conductive paste.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Creator Hisatoshi Murakami 2-3-1, Iwata-cho, Higashi-Osaka City, Osaka Prefecture Tatsuta Electric Wire Co., Ltd. (72) Tsunehiko Terada 2-3, Iwata-cho, Higashi-Osaka City, Osaka Prefecture No. 1 in Tatsuta Electric Wire Co., Ltd. (72) Inventor, Kihachi Ohnishi 2-3-1, Iwata-cho, Higashi-Osaka City, Osaka Prefecture (56) References JP-A-62-253675 (JP, A) ) Shokai 60-193621 (JP, U) JP 62-47328 (JP, B2) JP 6-62900 (JP, B2)

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. A shielded insulated wire in which a plastic film having a shield layer intermittently provided in the lengthwise direction is vertically attached on an insulating core wire, and a sheath is applied on the insulating core wire. A shielded insulated wire comprising a conductive paste coating layer made of the following conductive paint. Description "Resin mixture 10-25 containing 35-50% by weight of melamine resin, 20-35% by weight of polyester resin and 15-30% by weight of resol-type phenolic resin per 100 parts by weight of metallic copper powder.
A conductive coating composition comprising 0.1 part by weight, 0.1-2 parts by weight of a fatty acid or a metal salt of a fatty acid, and 0.5-4 parts by weight of a chelating agent. "