JPH08102219A - Thin insulated wire - Google Patents

Abstract

PURPOSE: To combine wear resistance and chemical resistance for a thin insulated wire which is formed by covering a conductor with an insulator by specifying the composition of the insulator. CONSTITUTION: A thin insulated wire is formed by covering a conductor 1 with an insulator 4. The insulator 4 has a combination of polyurethane layer mainly containing polyurethane of less than 25wt.% content macropolyol and polyvinyl chloride layer. Both of the polyurethane layer and the polyvinyl chloride layer are preferably formed by extrusion molding. Polyurethane as main component of the polyurethane composition layer is polymer, which is based on the polymerization of three components, long chained diol called macropolyol, short chained diol called chain extending agent and diisocyanate, with polyaddition reaction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin-wall insulated wire. More specifically, the present invention relates to a thin-walled insulated wire suitable as a wire harness for automobiles and an insulated wire for electronic devices.

[0002]

2. Description of the Related Art In recent years, along with the weight reduction of automobiles and the miniaturization of electronic equipment, weight reduction of wire harnesses and insulated wires used for them has been demanded. The task is to do so. However, in general, the insulator of these insulated wires is composed of a resin composition mainly composed of polyvinyl chloride, and this resin composition is inferior in mechanical strength when thinned, particularly wear resistance. The limit is about 0.35 mm. Therefore, recently, it has been proposed to further reduce the thickness of the resin composition mainly composed of polyvinyl chloride by using a resin composition mainly composed of polyurethane having excellent wear resistance (actual application). (Sho 61-23213).

However, in the case of such a resin composition mainly composed of polyurethane excellent in abrasion resistance, the chemical resistance is low, that is, when it is brought into contact with a chemical such as alcohol or glycol, cracking occurs and it deteriorates. Therefore, the range of use is narrow and the reliability is low.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object thereof is to eliminate the above-mentioned drawbacks of the prior art and to improve wear resistance and chemical resistance. It is to provide a combined thin-walled insulated wire.

[0005]

SUMMARY OF THE INVENTION The gist of the present invention is to provide a thin insulated wire comprising a conductor covered with an insulator, wherein the insulator has a macropolyol content of 25 wt%.
A thin-walled insulated electric wire is characterized by comprising a composite layer of a polyurethane layer whose main component is less than polyurethane and a polyvinyl chloride layer.

As a result of a detailed study of the relationship between the composition of polyurethane and the wear resistance and chemical resistance, the inventors have found that polyurethane having a macropolyol content of less than 25 wt% is a thin-wall insulated wire from the viewpoint of wear resistance. It has been found to be the best insulator. However, such polyurethane is vulnerable to chemicals such as alcohol and glycol, and could not be put into practical use.

Therefore, the inventors of the present invention have made earnest studies on this improvement, and as a result, other than that, by forming a composite layer with a polyvinyl chloride layer, a thin-walled insulated wire excellent in chemical resistance could be obtained. Is.

That is, the thin insulation of the present invention uses the polyurethane layer as an inner layer or an outer layer and polyvinyl chloride as an outer layer or an inner layer.

Both the polyurethane layer and the polyvinyl chloride layer are preferably formed by extrusion molding. In this case, it is desirable to bring both layers into contact with each other in a molten state in order to improve the adhesion between the layers.

For example, two extruders are connected to a common crosshead, a common extrusion method of simultaneously extruding two layers, a tandem extrusion method of arranging extruders in series and extruding an outer layer immediately after extruding an inner layer. Good adhesion can be obtained by the above.

The number of layers is not particularly specified, but from the viewpoint of cost, it is preferable that the number is 2 or 3. Regarding the order of the polyurethane layer and the polyvinyl chloride layer, either may be the inner layer or the outer layer.

In the present invention, the polyurethane component of the polyurethane composition layer is basically a polyaddition of three components, a long chain diol called a macropolyol, a short chain diol called a chain extender and a diisocyanate. It is a polymer obtained by increasing the molecular weight by a reaction.

As the macropolyol, polyester polyols such as polyethylene adipate glycol, polyethylene butanediol adipate glycol, polycaprolactone glycol and polycarbonate glycol having a molecular weight of about 500 to 5000, and polyoxytetramethylene ether glycol, polypropylene oxide ether glycol and the like. Can be used.

1,4 butanediol as a chain extender,
1,6 hexanediol, 1,5 pentanediol, 3
-Methyl-1,5 pentanediol and the like can be used. As the diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 4,4 'dicyclohexylmethane diisocyanate or the like can be used.

As a method for producing a polyurethane of this type, a macropolyol and a diisocyanate are partially or completely reacted in advance, and then a chain extender is reacted, that is, a so-called prepolymer method or all reaction raw materials are mixed at once. A known method such as a one-shot method can be adopted.

Further, as a method for polymerizing polyurethane, a continuous synthesis method using an extruder or a batch synthesis method can be adopted.

On the other hand, the polyvinyl chloride composition constituting the polyvinyl chloride layer is represented by polyvinyl chloride resin having an average degree of polymerization of 1000 to 2500, such as di- (2-ethylhexyl) phthalate and tri- (2-ethylhexyl) trimellitate. And a plasticizer to be used.

A colorant, a flame retardant, a lubricant, an anti-hydrolysis agent, an ultraviolet absorber, an antioxidant, a stabilizer, a filler and the like may be added to the polyurethane composition and the polyvinyl chloride composition, respectively, if necessary. can do. These may be compounded during the polymerization process of the polymer or after completion of the polymerization.

In the present invention, the content of macropolyol in the polyurethane, which is the main component of the polyurethane composition layer, is set to 25.
The reason why it is limited to less than wt% is that the abrasion resistance rapidly deteriorates in addition to 25 wt% or more.

[0020]

The thin-walled insulated wire of the present invention is a thin-walled insulated wire in which a conductor is coated with an insulator, wherein the insulator is a polyurethane layer containing polyurethane as a main component having a macropolyol content of less than 25 wt% and polychlorinated. By having a composite layer with a vinyl layer, it is possible to have both abrasion resistance and chemical resistance.

That is, the polyurethane layer alone is inferior in chemical resistance and the polyvinyl chloride layer alone is inferior in abrasion resistance and thus cannot be practically used. However, by extruding these into a plurality of layers, both layers are heat-sealed. It is possible to combine these characteristics.

[0022]

EXAMPLES Examples and comparative examples of the thin-wall insulated wire of the present invention will be described with reference to the drawings.

Table 1 shows the resin composition of polyurethane which is the main component of the polyurethane compositions used in Examples and Comparative Examples, and Table 2 shows the composition of the polyvinyl chloride composition.

Table 3 shows the results of testing various properties of the thin-walled insulated wires of the examples produced by combining the polyurethane composition of Table 1 and the polyvinyl chloride composition of Table 2.

Table 4 shows the results obtained by combining the polyurethane composition shown in Table 1 and the polyvinyl chloride composition shown in Table 2 to prepare a thin-walled insulated electric wire as a comparative example, and testing various properties thereof. is there.

The outer diameter of these thin insulated wires is φ.
100μm thickness on 0.72mm light compression annealed copper stranded conductor
Of the inner layer is then extruded, followed by an outer layer having a thickness of 100
It was extrusion coated to have a thickness of μm.

In the production of the thin-walled insulated wires of Comparative Examples 1 to 4 consisting of a single layer, a light-compression annealed copper stranded wire conductor having an outer diameter of 0.72 mm was extrusion-coated to a thickness of 200 μm. A tandem extrusion method was adopted for extrusion of the two-layer insulator.
A 20 mm extruder was used for the inner layer and a 19 mm extruder was used for the outer layer. Both screws were full flight type with L / D = 26 compression ratio 3. The extrusion temperature of the polyurethane composition is 22
0 to 240 ° C., the extrusion temperature of the polyvinyl chloride composition is 15
The temperature was 0 to 170 ° C.

The contents of the polyurethane chain extender and the diisocyanate, which are the main components of the polyurethane composition, were determined so as to satisfy the following conditions.

Number of moles of diisocyanate / (number of moles of macropolyol + chain extender) = 1 Abrasion resistance test and various insulated wires (Examples 1 to 4 and Comparative Examples 1 to 5) thus produced were tested. A chemical resistance test was conducted to evaluate the wear resistance and chemical resistance of each.

[0030]

[Table 1]

[0031]

[Table 2]

[0032]

[Table 3]

[0033]

[Table 4]

FIG. 1 shows an embodiment of the thin insulated wire of the present invention thus obtained.

In FIG. 1, 1 is a light compression annealed copper stranded conductor, 2
Is an inner layer, 3 is an outer layer, and 4 is an insulator.

This abrasion resistance test complies with the scrape (blade) test of JASO D-611 which is a standard for low voltage electric wires for automobiles. Specifically, as shown in FIG. 2, a blade 7 is provided at the tip. A reciprocating drive tester including an arm member 6, a drive unit 5 for horizontally reciprocating the arm member 6, and a weight 8 that loads the arm member 6 is used. The blade 7 provided on the
It is applied to the insulating coating layer 4 of the insulated electric wire A which is installed and fixed on the test table 10 by the clamp 9, and is stroked at a speed of 60 times per minute along the length direction with a width of 10 mm as shown by the arrow in the figure. The number of times until the insulating coating layer 4 is worn and comes into contact with the light compression annealed copper stranded wire conductor 1 is measured.
An insulated wire that can withstand 50 times or more was accepted. The weight 8 has a weight of 510 g, and the blade 7 has a tip radius R of 0.125 mm and a width W of 3 mm.

The chemical resistance test was carried out by winding the produced insulated wire A around its own diameter, immersing it in ethylene glycol at 50 ° C. for 240 hours, and then conducting an AC withstand voltage test at 1 kv / 1 min. Those that endured the test were accepted.

As can be seen from Table 4, in Comparative Examples 1 and 2 using the conventional polyvinyl chloride composition, the chemical resistance was good, but the wear resistance was remarkably low. Further, in Comparative Examples 3 and 4 made of only polyurethane, the abrasion resistance was excellent, but the chemical resistance was insufficient. Further, in Comparative Example 5 in which the inner layer was made of polyurethane C having a macropolyol content of 25 wt%, the chemical resistance passed, but the wear resistance was significantly reduced. As described above, the configurations of Comparative Examples 1 to 5 could not satisfy both the chemical resistance and the abrasion resistance. On the other hand, as can be seen from Table 3, the macropolyol content is 25
%, The thin-walled insulated wires of Examples 1 to 4 formed by combining the polyurethane compositions A and B having a polyol as the main component with the polyvinyl chloride compositions D and E have excellent wear resistance and chemical resistance. He showed his sex.

[0039]

Industrial Applicability The thin insulated wire of the present invention exhibits excellent wear resistance and chemical resistance and is industrially useful.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view showing an embodiment of a thin insulated wire of the present invention.

FIG. 2 is an explanatory diagram showing a wear resistance test method.

FIG. 3 is an enlarged explanatory view showing a size of a blade used in a wear resistance test.

[Explanation of symbols]

 1 Lightly compressed annealed copper stranded conductor 2 Inner layer 3 Outer layer 4 Insulator

Claims (7)

[Claims] 1. A thin-walled insulated wire comprising a conductor coated with an insulator, wherein the insulator has a macropolyol content of 25.
A thin-walled insulated wire comprising a composite layer of a polyurethane layer containing less than wt% of polyurethane as a main component and a polyvinyl chloride layer. 2. The inner layer of the insulator has a macropolyol content of 2
The thin-walled insulated wire according to claim 1, wherein the polyurethane layer whose main component is polyurethane of less than 5 wt% and the outer layer is a polyvinyl chloride layer. 3. The thin insulated wire according to claim 1, wherein the inner layer of the insulator is a polyvinyl chloride layer and the outer layer is a polyurethane layer containing polyurethane having a macropolyol content of less than 25 wt% as a main component. 4. The inner layer of the insulator has a macropolyol content of 2
7. A polyurethane layer containing polyurethane as a main component in an amount of less than 5 wt%, a polyvinyl chloride layer as an intermediate layer, and a polyurethane layer containing polyurethane in a main component having a macropolyol content of less than 25 wt% as a main component. The thin-wall insulated wire according to 1. 5. The insulating layer is characterized in that the inner layer is a polyvinyl chloride layer, the intermediate layer is a polyurethane layer containing polyurethane having a macropolyol content of less than 25 wt% as a main component, and the outer layer is a polyvinyl chloride layer. The thin-walled insulated wire according to Item 1. 6. The thin-walled product according to claim 1, wherein the polyurethane macropolyol is a polyester polyol selected from polyethylene adipate glycol, polyethylene butanediol adipate glycol, polycaprolactone glycol and polycarbonate glycol. Insulated wire. 7. The thin-walled insulated wire according to claim 1, wherein the polyurethane macropolyol is a polyether polyol selected from polyoxytetramethylene ether glycol and polypropylene oxide glycol.