JPH0535528Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] The present invention relates to a highly flexible insulated wire that is suitable as a wiring material for movable parts of electrical and electronic equipment, particularly for wiring materials that are repeatedly bent in a heated atmosphere. [Prior Art] Wiring materials used in movable parts of electrical and electronic devices that are repeatedly bent are required to have good bending performance. Therefore, these wiring materials generally include ultrafine annealed copper wire or copper as a conductor. Many products are used that have improved bending performance by using a conductor with good flexibility made by twisting together a large number of fine alloy wires, and by using a soft vinyl chloride resin mixture with rubber-like properties with high impact resilience for the insulating coating layer. There is. [Problems to be solved by the invention] However, although the above-mentioned conventional bend-resistant insulated wires exhibit excellent bending performance at room temperature,
It had the disadvantage that the bending performance was significantly reduced when exposed to a heated atmosphere of 80°C to 80°C. This is due to the fact that the elastic modulus, especially the bending elastic modulus, of the soft vinyl chloride resin (hereinafter referred to as soft PVC) that forms the insulating layer decreases significantly as the ambient temperature rises. Due to the decrease in the elastic modulus of the insulating layer, the deformation that occurs in the insulating layer during bending is easily transmitted directly to the conductor as stress, and the bending radius of the insulating layer during bending becomes smaller, causing the conductor to repeatedly experience strong local stress. As a result, the bending performance of the insulated wire was significantly reduced. [Means for Solving the Problems] The present invention aims to improve the above-mentioned drawbacks of conventional bend-resistant insulated wires and provide a highly flexible insulated wire that maintains excellent bending performance even in a heated atmosphere. That is. The highly flexible insulated wire of the present invention uses a plastic insulating material, which has a larger elastic modulus than soft PVC in the temperature range from room temperature to around 80°C, as the inner insulating layer of the soft PVC insulating layer, and is in contact with the conductor. The coating was formed by [Function] FIG. 1 is a cross-sectional view showing an embodiment of the highly flexible insulated wire of the present invention. 1 is a conductor, and a conductor with good bending resistance is used, such as a stranded wire made by twisting a large number of ultra-fine annealed copper wires or ultra-fine copper alloy wires. The outer periphery of the conductor 1 is coated as an inner insulating layer with a plastic insulating material that maintains high elasticity even in a heated atmosphere, and the outer periphery of the inner insulating layer 2 is further coated with an outer insulating layer 3 made of soft PVC. Highly flexible insulated wire 4
is configured. Here, as the plastic insulating material for the inner insulating layer 2, a material whose elastic modulus in the temperature range from room temperature to around 80° C. is larger than that of the soft PVC used for the outer insulating layer 3 is selected. Examples include fluorine-containing resins, high-density polyethylene, polyester elastomers, polyamides, polyether sulfones, and polyether ether ketones. These plastic insulating materials have a much higher elastic modulus than soft PVC from room temperature to around 80°C, and the decrease in elastic modulus due to temperature rise is extremely small. Its representative

〔Example〕

Next, the results of bending performance tests conducted at room temperature and in a heated atmosphere on samples of the present invention and conventional samples are shown below. (1) Sample

【table】 (2) Bending test conditions B Bending method: free bend (b) Radius of curvature of fulcrum: 0.5mm (3) Test results

[Effect of idea]

As mentioned above, as is clear from the bending test results of the embodiments of the present invention, the highly flexible insulated wire of the present invention, which has an insulating layer that maintains high elasticity in a heated atmosphere as an inner insulating layer of a soft PVC insulating layer, has a Since the bending properties in the temperature range from ℃ to 80℃ are greatly improved, it is ideal for use in lead wires for moving parts of electrical and electronic devices where the internal temperature of the device increases.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a highly flexible insulated wire showing an embodiment of the present invention. 1... Conductor, 2... Inner insulating layer, 3... Outer insulating layer (soft PVC insulating layer), 4... Highly flexible insulated wire.

Claims (1)

[Scope of utility model registration request] In a bend-resistant insulated wire in which the outer periphery of a conductor is coated with a soft vinyl chloride resin, the inner insulation layer of the soft vinyl chloride resin insulation layer is in contact with the conductor, and the elastic modulus in the temperature range from room temperature to around 80°C is as described above. A highly flexible insulated wire characterized by being coated with a plastic insulating material having a higher elastic modulus than that of soft vinyl chloride resin.