JPS61109207A - Insulated stranded wire - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to twisted insulated wires used as internal wiring for various electronic devices. In particular, it relates to twisted insulated wires in which a thin layer of insulating paint is applied to twisted conductors and cured.

(Prior Art and Problems) Twisted insulated wires used as internal wires of various electronic devices have conventionally been manufactured by coating twisted conductors with an insulating material by extrusion. Such insulated wires have been used alone or as elements of shielded wires, coaxial cables, or flat cables.

In recent years, as electronic devices have become smaller and lighter, there has been a trend toward making insulated wires, shielded wires, cables, and the like even thinner. One method is to make the insulating film covering the conductor thinner. For example, examples of insulated wires in which the twisted conductor is completely coated with insulating paint have already been published in Japanese Utility Model Applications No. 54-114783 and No. 57-99314. The present inventors have diligently studied thin film coating and curing technology and have proceeded with filing an application. As one of these methods, we have developed a method in which insulation paint is completely applied and cured.

When an insulating paint is applied and cured, a thin-film twisted insulated wire can be obtained. However, in the case of stranded wires compared to solid wires, even though the coating is properly hardened, if external force is applied to bend the coating, Ca cracks will occur in the coating compared to when the coating is applied to a single wire such as an enameled wire. There are many things to do.

The present application relates to a twisted insulated wire whose film thickness is designed so that the film does not crack when it is bent by applying an external force, and will be described in detail below.

(Structure of the Invention) The main point of the present invention is to provide a twisted insulated wire having a coating thickness ratio of 15% or more to the radius of the twisted conductor, in which the twisted conductor is completely coated with insulation paint and cured. be.

Twisted insulated wires are used as in-machine wiring for various electronic devices, so they are often bent or stretched under external forces, and if the external forces cause cracks in the coating, they cannot be put to practical use. A film obtained by applying an insulating paint to a twisted conductor and curing it can be made much thinner than a film coated by an extrusion method. However, when thinning the film, when conducting a so-called self-returning test in which twisted insulated wires were wound around a mandrel with the same finished outer diameter, cracks occurred in the film even though the film had been cured to an appropriate degree. I had something to do. When we investigated the use of insulating paint for enamelled wire, solvent-free hot melt paint, or UV or electron beam irradiation hardening paint, we found that in any case, self-winding would result in cracks in the film. Occasionally this occurred.

On the other hand, when an insulating paint is applied to a single conductor such as an enameled wire and cured, when the paint is self-wrapped, cracks hardly occur in the film.

The present inventors manufactured stranded insulated wires by changing the fundamental sound of the coating on stranded conductors of various sizes, and found that in order to pass the self-winding test, the ratio of the coating thickness to the diameter of the stranded conductor must be 15% or more in most cases. It was discovered that the coating of the stranded insulated wire coated on the stranded conductor of the present invention is thicker at the gap between the strands, as shown in FIG. It is estimated that if self-warping is carried out in such a film state, the force applied to the film will be different even if the same elongation is applied to the entire film, and the degree of adhesion between the single wire that makes up the twisted conductor and the film will decrease. . Furthermore, since a plurality of twisted conductors are twisted into a single wire, there are gaps between the twisted wires, and the single wires that make up the entire twisted conductor are relatively likely to move and deform in response to external forces. the result,
The elongation of the film varies depending on the part, and some parts are extremely elongated. The degree of adhesion decreases in areas with good elasticity. A film with reduced adhesion to the conductor shows a tendency to crack or break more easily due to external forces than when the adhesion with the conductor is maintained strongly.

In order to prevent the occurrence of such film cracks, it is conceivable to improve the degree of adhesion between the conductor and the film, or to make the original sound of the film above a certain level in order to maintain the overall strength of the film above a certain level. It is quite difficult to increase the degree of adhesion between the conductor and the coating when the conductor material or coating material is determined. is a twisted conductor, (2-1) is an insulating film existing between the twisted wires, and (2-2) is also an insulating film.

In the present invention, the twisted conductor radius ftD1 is defined as the total thickness of the insulation coating. Then, when self-returning winding was performed depending on the ratio of the insulation coating thickness d to the radius of the twisted conductor (d/DX100C%), the coating either cracked or did not crack. In the experiments conducted by the present inventors, there was some variation in the modulus of elasticity and elongation at break depending on the type of insulation film.-1
It has been fully understood that in many cases it is necessary to provide a film with an original sound exceeding d/Dx100=15C%].

In other words, for twisted insulated wires manufactured by applying insulation paint to a fully twisted conductor and curing it, the value of d/DX100 (%) must be increased by 15% in order to prevent cracks from occurring in the film due to self-winding. It turns out that.

The insulating material used in the present invention can be any material used for general electrical insulating materials. For example, polyvinyl formal, polyester, polyurethane, polyesterimide, and polyamide are insulating paints for enameled wires.
It is possible to use materials such as toimide, polyimide, polysulfone, polyethersulfone, epoxy resin, polycarbonate, etc.

Hereinafter, all embodiments of the present invention will be explained.

Comparative Example 1゜Tin-plated copper wire and fc twisted conductor 710.127 (
A polyester insulating paint was applied to the 7 strands (with a diameter of 0.127 mm) using a die sound and baked. The manufacturing conditions are as follows.

Number of coating and baking: 10 times Film thickness: Q, 010 mm Baking temperature
When a twisted insulated electric wire manufactured at 300° C. and a wire speed of L 5 m/min was wound around a mandrel having a full self-diameter for two turns, cracks occurred in the coating.

Comparative Example 2 Twisted conductor made of copper wire plated with tin (diameter 0.050rr
+n1 7 strands) and polyurethane insulation paint 7e 7L/
) was used to coat and bake.

The manufacturing conditions are as follows.

Number of times of coating and baking: 10 Coating thickness: 0.010 mm Baking temperature: 240°C Wire speed: 20 m/min When the produced twisted insulated wire was wound around a mandrel tζ of its own diameter, cracks were completely generated in the coating.

Comparative Example 3゜Twisted conductor 710.127 (7 strands with a diameter of 0.127 mm) made of tin-plated copper wire was coated with urethane acrylate-based ultraviolet curing paint using a die and irradiated with ultraviolet light. hardened by

The manufacturing conditions are as follows.

Number of times of coating and curing: 4 times Film thickness: 0.0 20 mm UV irradiation
80 W/an, lamp length 1m line speed
When a twisted insulated wire manufactured at a speed of 15 m/min was wound around a self-diameter mandrel, cracks appeared in the coating.

Example 1゜ Everything is the same as Comparative Example 1 except as described below.

Coating and baking: 413 times Coating thickness: 0.0 30 When the manufactured twisted insulated wire was wound around a mandrel having its own diameter, no cracks occurred in the coating.

Example 2゜Same coating and baking times as Comparative Example 2 except as described below.
When the stranded insulated wire with a coating thickness of 0.013ffllI+ was wound around a mandrel of its own diameter 12 times, no cracks occurred in the coating.

Example 3゜ Everything is the same as Comparative Example 3 except as described below.

Number of times of coating and curing: 4 Coating thickness: 0.038 mm When the produced twisted insulated wire was wound around a mandrel of its own diameter, no cracks occurred in the coating.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a twisted insulated wire manufactured by coating a twisted conductor with an insulating paint and curing it. It shows. 1'-Continued Amendment January 1985 l''8 [1 1, Indication of the case 1975 Patent Application No. 231838 OK 2 Name of the invention Twisted insulation 112 glands 3, Person making the amendment Relationship to the case Patent Applicant Address: 15 Kitazume 5-chome, Higashi-ku, Osaka Name (2)
13) Kawakami, President of Sumitomo Electric Zn Type Company
Tetsubu 4, Agent Address: V-3, 1-chome, Shimaya, Konohana-ku, Osaka City, Sumitomo Electric Industries, Ltd. Column 7, Detailed explanation of the invention in 6th supplementary specification 8, Contents (1) Details 9th line 4th line 7 “Application for stranded conductor... 1 application has been reached. 1 application for stranded conductor...
...Correct Jf to j. (2) In the 6th μth line of the specification 3, correct the line [1 [15%...] to ``If it does not exceed 15%, Q...J. (3) In the specification, page 6 From line 17 to line 18, correct d to "(7-strand twist of direct 0.127JII!+) J t r+, 7-strand twist of tsiIIA with diameter 0.127JIJI". (4) Ming [Old 7th Tei No. 8 (Tth to 9th line "Twisted conductor (7 items with diameter iJ, 050n+) J [Twisted conductor 710, U
50 (7 straight 0.050 German m wires) J (5) Correct ``(7 strands with a diameter of 0.127 Jff)'' from the 19th to the 20th lines of the 7th edition of the specification. (Diameter 0.1
Corrected to ``7 strands of 27 tomo single wire)''.

Claims (1)

[Claims] (1) A twisted insulated wire, which has an insulating coating coated and baked on a twisted conductor, and has a ratio of insulation film thickness to twisted conductor radius of more than 15%.