JPH03152811A - Manufacture of heat resisting thin insulated wire - Google Patents

Abstract

PURPOSE:To obtain an excellently flexible thin insulated wire by extruding a thermoplastic polyether ether ketone resin or polyimide resin for coating while heating to a determined temperature or more into fused state, when a coat layer having less than a determined thickness is extruded on a conductor by use of the resin. CONSTITUTION:A conductor 11 supplied from a supply 10 is preliminarily heated to a temperature of 100 deg.C or more by passing through a preheating material 12, and then guided to an extruder cross head 13. Then, a heat resisting resin 16 such as polyether ether ketone or polyimide heated and melted to at least the melting point (350 deg.C) or more is extruded on the conductor from an extruder 15 by use of a die 14 to coat the conductor followed by cooling and solidifying by a cooling tank 17, received by a receiver 18, and wound on a winder 19. In this constitution, the thickness of the layer extruded on the conductor 11 for coating is regulated to less than 0. 25mm, and the temperature of the melted resin is 100 deg.C or above.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a manufacturing method for obtaining thin-walled insulated wires by extrusion molding using thermoplastic polyetheretherketone resin or polyimide resin having extremely high heat resistance.

[Conventional technology and its issues]

For example, polyether-1, which has relatively high strength at temperatures above 100°C, compensates for the heat resistance, which is one of the drawbacks of general-purpose plastic materials such as polyethylene (PE) and polypropylene (PP). Materials called engineering plastics, such as (PC) and polybutylene terephthalate (PBT), were promoted from 1960 to 1980.

And in recent years, it has even higher heat resistance, has a softening temperature of 300°C or higher, and can be used for long periods of time even at high temperatures of about 150°C. For example, polyetheretherketone (PEEK)
), polyimide (PI), and other materials commonly known as super engineering plastics have been developed, and because of their excellent physical properties, light weight, chemical resistance, and abrasion resistance, they are adding value to various fields. It is attracting a lot of interest as a new material that enhances the quality of life.

For example, if a heat-resistant material such as PEEK or PI is used as a wire sheathing material, the thickness of the conventional sheathing material can be reduced, making it possible to develop insulated wires that are lighter and thinner.

[Means to solve the problem]

The present invention uses thermoplastic polyetheretherketone resin or polyimide resin, which has extremely high heat resistance,
As a result of various studies on a method for manufacturing insulated wires with improved flexibility by forming a coating layer with a thickness of less than 0.25+ am on a conductor by melt extrusion molding, we found that 100
It has been found that a heat-resistant, thin-walled insulated wire with excellent flexibility can be obtained by extrusion coating to a thickness of less than 0.25 ma+ on a conductor heated to a temperature of .degree. C. or higher.

That is, the present invention uses thermoplastic polyetheretherketone resin or polyimide resin to coat the conductor with a thickness of 0.
．． The present invention relates to a method for manufacturing a heat-resistant thin-walled insulated wire, which comprises extrusion-molding a molten resin onto a conductor heated to 100° C. or higher to form a coating layer of less than 25 mm.

One embodiment of the present invention is shown in FIG. Supply (10
) The conductor (11) supplied from the extruder crosshead (
13), and at Dan 9F4), the extruder (15)
Heat-resistant resin (16
) is extrusion coated onto the conductor, followed by cooling bath (I
7), and is taken up and wound up by a take-up machine (18) (19).

In the manufacturing method of such a heat-resistant insulated wire, Figure 2 shows the flexibility of the insulated wire (self-diameter winding) obtained by obtaining the relationship between the temperature of the conductor introduced into the crosshead of the extruder and the extruded coating thickness. (Cranks that generate coating layers)

From now on, when extruding materials such as PEEK or PI with a coating thickness of 0.25+ma or more, the conductor temperature will not have as much of an effect as on the left, but as the thickness decreases from 0.25m1, the conductor should be heated to 100℃ or more. The insulated wire obtained by this heating can be a heat-resistant, thin-walled insulated wire with excellent flexibility and no cracks in the coating layer even when wound on its own diameter.

In fact, a method for obtaining heat-resistant thin-walled insulated wires using resins such as PEEK and PI is to extrude coat the conductor by ordinary extrusion molding at a high temperature above the melting point (350°C). It is done by

The heat-resistant, thin-walled insulated wire thus obtained is required not only to have heat resistance and electrical insulation properties, but also to have flexibility when wiring the insulated wire in a space-saving manner. The important point is that no cracks (crank) occur in the coating layer when the wire is bent by bending.
If it is 5+w or more, cracks will not occur in the coating layer even if it is wrapped around the minimum diameter (diameter equal to the wire outer diameter: self diameter), but as the coating thickness becomes less than 0.25 m, cracks will not occur in the bending layer. The diameter gradually increases, i.e.
The thinner the wire, the more likely it is that cracks will form in the coating layer if the bending diameter is small, making it unsuitable for space-saving wiring, which is the original purpose of heat-resistant thin-walled insulated wire. There is a troubling phenomenon. Although not all of the reasons have been clearly established, it is assumed that the reasons for this are as follows.

Compared to general-purpose resins such as polyethylene and polypropylene, resins such as PEEK and PI are characterized by their extremely high melting point, high crystallinity, and extremely low elongation at room temperature. When the conductor is extruded and coated in its molten state, heat is removed by the conductor, resulting in changes in flow characteristics (melt viscosity and melt tension) in the thickness direction.
and the crystal structure changes complicatedly, especially in the case of thin walls,
This seems to be due to the fact that the overall thickness cannot cover the complex changes in the state near the conductor, and the originally low elongation becomes even lower.

As can be seen from FIG. 2, the heating temperature of the conductor is more preferably 160° C. or higher in order to easily form the conductor, no matter how thin the conductor is.

In addition, the wire extrusion equipment used in the present invention is basically any equipment that can raise the temperature of the material to a temperature higher than the softening temperature.
An extruder for extruding general-purpose resins (PE, PP, etc.) or a crosshead (die, nipple, etc.) for extruding electric wires can be used as is. In particular, it is preferable to use a crosshead that has been developed as a non-aligning type.

〔Example〕

Comparative Example 1 Polyetheretherketone resin (manufactured by Mitsui Toatsu Co., Ltd.,
The extrusion temperature was 4 using a 30φ extruder using a softening temperature of 334°C.
At 00℃, on a 0.9φ copper wire (with a pull diameter of 0.9I),
Covering pressure 0.25mm (Dice diameter 1.4mm) Covering pressure 0.2mm (Dice diameter 1.3mm) without preheating the conductor.
am), coating thickness 0.15mm (Dice diameter), 2m
m), coating thickness 0.1 mm (Dice thickness 1.], mm)
Extrusion coating was performed under each condition with a coating thickness of 0.05 nu (dice diameter of 1.0 mm).

Then, the obtained insulated wire was wound to a diameter 3 times its own diameter and a diameter 5 times its own diameter, and the presence or absence of wrinkles occurring in the coating layer was examined. The results obtained are shown in Table 1.

Comparative Example 2 Thermoplastic polyimide resin (manufactured by Mitsui Toatsu Co., Ltd.) was extrusion coated using a 30φ extruder at an extrusion temperature of 450"C using a softening temperature of 390"C under the same conditions as Comparative Example 1. The obtained insulated wire was evaluated in the same manner as in Comparative Example 1. The obtained results are shown in Table 1.

Example 1 In Comparative Example 1, the heating temperature of the conductor was set to 100°C and 1160°C.
An insulated wire was manufactured under the conditions of extrusion coating with a coating thickness of 0.25 to 0.05 mm, and the obtained insulated wire was evaluated in the same manner as in Comparative Example 1. The results are shown in Table 1.

Example 2 In Comparative Example 2, the heating temperature of the conductor was set to 100"C1160
An insulated wire was manufactured under the conditions of extrusion coating with a coating thickness of 0.25 to 0.05 mm in degrees Celsius, and the obtained insulated wire was evaluated in the same manner as in Comparative Example 1. Table 1 shows the results.

〔Effect of the invention〕

As is clear from the examples described above, in the extrusion production of heat-resistant thin-walled insulated wires with a coating thickness of 0.25 mm or less using PEEK or PI resin, flexible It is possible to obtain thin-walled insulated wires with excellent performance, and has great industrial value in the field of manufacturing heat-resistant, thin-walled insulated wires with excellent workability and space-saving wiring, for which demand is expected to increase in the future. There is.

[Brief explanation of the drawing]

Figure 1 is a production line diagram of one embodiment of the method of the present invention, and Figure 2 is a plot of the relationship between the conductor temperature introduced into the extruder crosshead and the extruded coating thickness and the flexibility of the insulated wire. This is a diagram. 10... Supply, 11... Conductor, 12...
Preheater, 13... Crosshead, 14... Dice, 15... Extruder, 16... Molten resin, ]7.
...Cooling water tank, 18...Take-up machine, 19... Winding machine.

Claims (1)

[Claims] When extruding a coating layer with a thickness of less than 0.25 mm on a conductor using thermoplastic polyetheretherketone resin or polyimide resin, the molten resin is heated to 100°C.
A method for producing a heat-resistant, thin-walled insulated wire, the method comprising extruding coating onto a conductor heated as described above.