Insulated wire and preparation method thereof, coil and electronic / electrical device

Abstract

The present invention discloses an insulated wire and a preparation method thereof, a coil and an electronic / electrical device, which relate to the technical field of insulated wires, and include a conductor and a bottom layer and an outer insulating layer sequentially arranged on the periphery of the conductor, wherein the bottom layer and the outer insulating layer serve together as the insulating layer of the insulated wire; wherein the material of the bottom layer is phenolphthalein polyaryletherketone; and the material of the outer insulating layer is obtained by blending and granulating polyetheretherketone and phenolphthalein polyaryletherketone. The insulated wire provided by the present invention adds a PEK-C layer as a bottom layer between the outer insulating layer and the metal conductor, which can improve the adhesion between PEEK and copper and reduce the risk of tube derailment and fracture; at the same time, the outer insulating layer adopts a blended resin obtained by blending PEEK and PEK-C, which can improve the flexibility of the outer insulating layer, improve the adhesion between the outer insulating layer and the bottom layer, and reduce the friction coefficient of the outer insulating layer.

Description

Technical Field

[0001] The present invention relates to the technical field of insulated wires, and more particularly to an insulated wire and a preparation method thereof, a coil and an electronic / electrical device. Background Art

[0002] Polyetheretherketone (PEEK) is a high-performance thermoplastic polymer known for its excellent mechanical properties, chemical resistance and good electrical insulation properties. Especially in the field of electrical engineering, PEEK is often considered as an insulating material for wires due to its excellent electrical insulation properties and high operating temperature range. However, some problems have been encountered in the actual application of PEEK in insulated wires, including poor adhesion between PEEK and metal conductors. This poor adhesion not only affects the mechanical strength of the product, but may also lead to the risk of insulation peeling during use, which in turn affects the safe operation of electrical equipment.

[0003] Phenolphthalein-based Polyaryl ether ketone (PEK-C) is an amorphous polymer in the PAEK family, with high heat resistance, high strength, high modulus and excellent dimensional stability. In addition, PEK-C also exhibits good electrical insulation, corrosion resistance, radiation resistance, self-flammability and excellent fatigue resistance, making it an ideal choice for many high-performance applications. Especially in terms of tribological properties, PEK-C shows advantages over PEEK.

[0004] Although PEK-C has many advantages, there are few research reports in the existing technical literature on combining it with PEEK to improve the performance of insulated wires.

[0005] The present invention aims to propose a new solution based on the synergistic effect of PEEK and PEK-C to solve the above-mentioned technical problems faced by traditional PEEK insulated wires. Summary of the invention

[0006] In view of this, an object of the present invention is to provide a new insulated wire to solve the problems of low adhesion between PEEK resin and conductor and poor flexibility of the insulated wire in the prior art.

[0007] To achieve the above object, the technical solution of the present invention is as follows:

[0008] The structure of the phenolphthalein polyaryletherketone has a repeating unit as shown in the following formula 1:

[0009]

[0010] Formula 1.

[0011] The phenolphthalein polyaryletherketone may be a conventional commercially available product, such as the phenolphthalein polyaryletherketone (Mw is about 52,000) produced by Xuzhou Engineering Plastics Factory of Changchun Institute of Applied Chemistry, Chinese Academy of Sciences.

[0012] In addition, the present invention also obtains PEK-C by laboratory synthesis. Phenolphthalein and dichlorobenzophenone are added to a mixed solution of DMAC and ethylbenzene in an equivalent ratio, and the temperature is gradually increased from 150 to 200°C under alkaline catalysis conditions for 2 hours. After the reaction, the viscosity of the system is about 1.1 dL / g, and the weight average molecular weight (Mw) of the product is about 50,000.

[0013] The first aspect of the present invention is to provide a device including a conductor, and a bottom layer and an outer insulating layer sequentially arranged on the periphery of the conductor; wherein the material of the bottom layer is phenolphthalein polyaryletherketone.

[0014] In the present invention, along the unilateral direction outward from the conductor, the thickness of the bottom layer is not more than 10 μm, preferably, the thickness of the bottom layer is 5-10 μm.

[0015] In order to obtain better flexibility of the outer insulating layer, in the present invention, the outer insulating layer is a blended resin obtained by blending and granulating polyetheretherketone and phenolphthalein polyaryletherketone, wherein the mass ratio of phenolphthalein polyaryletherketone is not more than 50%.

[0016] The crystallinity of the blended resin of the outer insulating layer of the present invention is not less than 10%, and the crystallinity of the blended resin of the outer insulating layer is 10-28%. In the present invention, PEK-C is amorphous. In the blending of PEK-C and PEEK, PEK-C and PEEK have good compatibility. PEK-C reduces the crystallinity of PEEK, so that the material exhibits better flexibility.

[0017] The second part of the present invention is to provide a method for preparing the insulated wire, characterized in that the insulated wire is prepared by an extrusion method, specifically comprising the following steps:

[0018] After the bottom layer resin is heated to a temperature of 370-400°C to reach a molten state, the bottom layer resin material is extruded through the first flow channel of the screw extruder and evenly coated on the copper conductor to obtain a core wire. After the outer insulating layer resin material is heated to a temperature of 370-400°C to reach a molten state, the outer insulating layer resin material is extruded through the second flow channel of the screw extruder and evenly coated on the core wire, and the insulated wire is obtained after cooling.

[0019] A third object of the present invention is to provide a coil composed of the above-mentioned insulated wire.

[0020] The present invention also aims to provide an electrical or electronic device prepared from the coil.

[0021] The present invention also aims to provide a co-extrusion die for processing the insulated wire, the die comprising a die core, a conductor delivery channel being formed through the center of the die core, a first flow channel and a second flow channel being formed in an annular shape and concentrically arranged along the outer periphery of the conductor delivery channel in sequence, the longitudinal cross-sections of the first flow channel and the second flow channel being trumpet-shaped, comprising an inclined flow channel section and a horizontal section parallel to the conductor delivery channel, the conductor of the insulated wire being delivered from the front end to the rear end of the die core via the conductor delivery channel, the resin material of the bottom layer in a molten state flows in via the inclined section of the first flow channel, then flows out via the horizontal section of the first flow channel, and is coated on the outer periphery of the conductor to form the bottom layer of the insulated wire; at the same time, the resin material of the outer insulating layer in a molten state flows in via the inclined section of the second flow channel, then flows out via the horizontal section of the second flow channel, and is coated on the outer periphery of the bottom layer to form the outer insulating layer of the insulated wire, and the insulated wire is formed after cooling.

[0022] The mold for processing insulated wires provided by the present invention can form a bottom layer and an outer insulating layer on a conductor at the same time without preheating the conductor multiple times, thereby improving production and processing efficiency.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] The insulated wire provided by the present invention adds a PEK-C layer as a bottom layer between the outer insulating layer and the metal conductor, which can improve the adhesion between PEEK and copper and reduce the risk of tube detachment and breakage; at the same time, PEK-C is mixed into the outer insulating layer PEEK, which can improve the adhesion between the outer insulating layer and the bottom layer, while also reducing the overall crystallinity of the outer insulating layer and improving the flexibility of the wire. The low friction coefficient of PEK-C can also make the insulated wire have a lower static friction coefficient, which is convenient for insertion into the stator. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural diagram of a mold used for processing an insulated wire in the present invention.

[0026] Figure 2 It is a schematic diagram of the side cross-sectional structure of the insulated wire in the present invention.

[0027] In the figure,

[0028] 1. Mold core; 2. Conductor conveying channel; 3. First flow channel; 4. Second flow channel; 5. Inclined section; 6. Horizontal section.

[0029] 10. Conductor; 20. Bottom layer; 30. Outer insulation layer. DETAILED DESCRIPTION

[0030] Many specific details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar modifications without violating the connotation of the present invention, so the present invention is not limited to the specific implementation disclosed below.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0032] like Figure 1 and Figure 2 As shown, the present invention provides a mold for processing an insulated wire, which includes a mold core 1, a conductor conveying channel 2 is formed through the center of the mold core 1, and a first flow channel 3 and a second flow channel 4 are formed in an annular shape and concentrically arranged along the outer periphery of the conductor conveying channel 2 in sequence, the first flow channel 3 and the second flow channel 4 have a trumpet-shaped longitudinal cross-section, and include an inclined section 5 and a horizontal section 6 parallel to the conductor conveying channel 2, and the conductor 10 of the insulated wire is conveyed from the front end to the rear end of the mold core 1 through the conductor conveying channel 2, and the resin material of the bottom layer in a molten state flows in through the inclined section 5 of the first flow channel 3, and then flows out through the horizontal section 6 of the first flow channel 3, and is coated on the outer periphery of the conductor 10 to form the bottom layer 20 of the insulated wire; at the same time, the resin material of the outer insulating layer in a molten state flows in through the inclined section 5 of the second flow channel 4, and then flows out through the horizontal section 6 of the second flow channel 4, and is coated on the outer periphery of the bottom layer 20 to form the outer insulating layer 30 of the insulated wire, and the insulated wire is formed after cooling. Specifically, when the outer insulating layer is a blended resin, the blended resin is obtained by blending PEEK granules and PEK-C granules at 370-400° C. through a twin-screw extruder to form a uniform mixing system, which is then granulated into a particle polymer material through a pelletizer after cooling.

[0033] Example 1

[0034] The present embodiment provides an insulated wire, which can be prepared by co-extrusion using the mold and method provided above, and includes a metal conductor copper and an outer insulating layer wrapped around the outer periphery of the copper, and the outer insulating layer includes two layers, namely a bottom layer and an outer insulating layer on the outside. Among them, the metal conductor is a 1.00ⅹ2.00 (mm) metal flat wire. The bottom layer in contact with the conductor is phenolphthalein polyaryletherketone. The material of the outer insulating layer is polyetheretherketone (PEEK). Conductor preheating temperature: 280-330℃; PEK-C extrusion temperature: 370-400℃; PEEK extrusion temperature: 370-400℃. The thickness of the bottom layer is 8μm, and the thickness of the PEEK outer insulating layer is 92μm, that is, the total thickness of the insulating layer is 100μm.

[0035] Example 2

[0036] An insulated wire was prepared by the method of Example 1, wherein the thickness of the PEK-C bottom layer was 10 μm, the thickness of the PEEK outer insulating layer was 110 μm, and the total thickness of the insulating layer was 120 μm.

[0037] Example 3

[0038] An insulated wire was prepared by the method of Example 1, wherein the thickness of the PEK-C bottom layer was 5 μm, the thickness of the PEEK outer insulating layer was 75 μm, and the total thickness of the insulating layer was 80 μm.

[0039] Example 4

[0040] The method as in Example 1 is adopted, wherein the material of the outer insulating layer is prepared from a blend of PEEK and PEK-C. Conductor preheating temperature: 280-330°C; PEK-C extrusion temperature: 370-400°C; outer insulating layer extrusion temperature: 370-400°C. In the blend, PEK-C accounts for 10% by weight, and the rest is PEEK. The thickness of the PEK-C bottom layer of the extruded wire is 10 μm, and the thickness of the outer insulating layer is 110 μm, that is, the total thickness of the insulating layer is 120 μm.

[0041] Example 5

[0042] The method of Example 4 is adopted, wherein the material of the outer insulating layer is prepared from a blend of PEEK and PEK-C. In the blend, PEK-C accounts for 5% by weight, and the rest is PEEK. The thickness of the PEK-C bottom layer of the extruded wire is 10 μm, the thickness of the outer insulating layer is 110 μm, and the total thickness of the insulating layer is 120 μm.

[0043] Example 6

[0044] The method of Example 4 is adopted, wherein the material of the outer insulating layer is prepared from a blend of PEEK and PEK-C. In the blend, PEK-C accounts for 20% by weight, and the rest is PEEK. The thickness of the PEK-C bottom layer of the extruded wire is 5 μm, the thickness of the outer insulating layer is 75 μm, and the total thickness of the insulating layer is 80 μm.

[0045] Example 7

[0046] The method of Example 4 is adopted, wherein the material of the outer insulating layer is prepared from a blend of PEEK and PEK-C. In the blend, PEK-C accounts for 30% by weight, and the rest is PEEK. The thickness of the PEK-C bottom layer of the extruded wire is 8 μm, the thickness of the outer insulating layer is 92 μm, and the total thickness of the insulating layer is 100 μm.

[0047] Example 8

[0048] The method of Example 4 is adopted, wherein the material of the outer insulating layer is prepared from a blend of PEEK and PEK-C. In the blend, PEK-C accounts for 40% by weight, and the rest is PEEK. The thickness of the PEK-C bottom layer of the extruded wire is 10 μm, the thickness of the outer insulating layer is 110 μm, and the total thickness of the insulating layer is 120 μm.

[0049] Example 9

[0050] The method of Example 4 is adopted, wherein the material of the outer insulating layer is prepared from a blend of PEEK and PEK-C. In the blend, PEK-C accounts for 49% by weight, and the rest is PEEK. The thickness of the PEK-C bottom layer of the extruded wire is 10 μm, the thickness of the outer insulating layer is 110 μm, and the total thickness of the insulating layer is 120 μm.

[0051] Comparative Example 1

[0052] The insulated wire was prepared by the method of Example 1, without extruding the bottom layer, and the PEEK outer insulating layer was directly coated on the metal conductor. The thickness of the outer insulating layer was 100 μm, and the total thickness of the insulating layer was 100 μm.

[0053] Comparative Example 2

[0054] An insulated wire was prepared by the method of Example 1, wherein the thickness of the PEK-C bottom layer was 15 μm, the thickness of the PEEK outer insulating layer was 85 μm, and the total thickness of the insulating layer was 100 μm.

[0055] Comparative Example 3

[0056] An insulated wire was prepared by the method of Example 1, wherein the thickness of the PEK-C bottom layer was 20 μm, the thickness of the PEEK outer insulating layer was 80 μm, and the total thickness of the insulating layer was 100 μm.

[0057] Comparative Example 4

[0058] An insulated wire was prepared by the method of Example 1, wherein the thickness of the PEK-C bottom layer was 25 μm, the thickness of the PEEK outer insulating layer was 75 μm, and the total thickness of the insulating layer was 100 μm.

[0059] Comparative Example 5

[0060] The method of Example 4 is adopted, wherein the material of the outer insulating layer is prepared from a blend of PEEK and PEK-C. In the blend, PEK-C accounts for 60% by weight, and the rest is PEEK. The thickness of the PEK-C bottom layer of the extruded wire is 10 μm, the thickness of the outer insulating layer is 110 μm, and the total thickness of the insulating layer is 120 μm.

[0061] Comparative Example 6

[0062] The method of Example 4 is adopted, wherein the material of the outer insulating layer is prepared from a blend of PEEK and PEK-C. In the blend, PEK-C accounts for 80% by weight, and the rest is PEEK. The thickness of the PEK-C bottom layer of the extruded wire is 10 μm, the thickness of the outer insulating layer is 110 μm, and the total thickness of the insulating layer is 120 μm.

[0063] Comparative Example 7

[0064] The method of Example 4 is adopted, wherein the material of the outer insulating layer is made of PEEK. The thickness of the PEK-C bottom layer of the extruded wire is 10 μm, the thickness of the outer insulating layer is 110 μm, and the total thickness of the insulating layer is 120 μm.

[0065] Performance Testing

[0066] The following tests were performed on the insulated wires prepared in Examples 1-9 and Comparative Examples 1-7:

[0067] 1. Adhesion test

[0068] The adhesion test method provided by IEC-60851-3 2019 Test Method 8 is used for testing. The specific steps are as follows:

[0069] Take 300 mm of the insulated wire obtained in the embodiment and the comparative example as a sample, cut a circle of the sample in the middle position until the conductor, and then place the sample between two clamps. The sample and the clamp are placed on the same axis, clamp both ends, stretch 15% at a rate of 300 mm / min, and measure the length of the sample insulation layer that loses adhesion.

[0070] 2. Flexibility test

[0071] The insulated wires of the embodiments and comparative examples were tested for flexibility according to the following methods.

[0072] The flexibility test is carried out using the flexibility test method provided by IEC60851-3 2019 test method 8. The specific steps are as follows:

[0073] Take two 500mm long straight insulated wires, bend them 180±2° around a polished test core, one for flat winding (core diameter = N times wire thickness), the other for vertical winding (core diameter = N times wire width). In this test, after flat winding and vertical winding, the product with smooth surface and no cracks is recorded as "qualified"; the surface cracks are recorded as "unqualified".

[0074] Table 1. Properties of composite wires with PEK-C bottom layer and PEEK outer insulation layer

[0075]

[0076] Table 2. Properties of composite wires made of PEK-C bottom layer and PEEK and PEK-C mixture outer insulation layer

[0077]

[0078] It can be seen from the above embodiments that adding PEK-C to PEEK can well compensate for the lack of flexibility. The thickness of the bottom layer is preferably less than 10μm. Experiments show that if the PEK-C layer is too thick, it is easy to cause insufficient elongation at break of the insulating layer, thereby reducing adhesion. PEK-C has no phase change at high temperature and has a lower thermal expansion coefficient, so it has good adhesion to copper. Using PEK-C as the outer insulating layer can increase the adhesion of the insulated wire, and PEK-C and PEEK belong to the same polyaryletherketone class and have good compatibility. The second layer uses a blend of PEK-C and PEEK to improve the flexibility of the entire outer insulating layer, and due to the low friction coefficient of PEK-C, it can also make the insulated wire have a lower static friction coefficient, which is convenient for insertion into the stator.

[0079] In terms of processing methods, the bottom layer of the present application is processed by extrusion, which is not only highly efficient but also environmentally friendly. And there is less damage to the conductor. In the past, it was necessary to coat the paint liquid on the outside of the conductor multiple times, and obtain the bottom layer after multiple baking and cooling. During this period, the conductor needs to undergo multiple heating and cooling shocks, which will inevitably reduce the performance of the conductor. Moreover, multiple coatings will make the baking degree of each layer inconsistent. The baking time of the innermost layer is the longest, and the baking time of the outermost layer is the shortest, which makes the innermost layer have the risk and disadvantage of over-baking, and the outermost layer has the disadvantage of insufficient baking. The bottom layer and the outer insulating layer of the present application are extruded at the same time, and the processing conditions of the two layers are consistent, which will not add additional burden to the conductor.

[0080] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0081] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An insulated wire, characterized in that: The invention comprises a conductor and a bottom layer and an outer insulating layer sequentially arranged on the periphery of the conductor; wherein the material of the bottom layer is phenolphthalein polyaryletherketone, and the structure of the phenolphthalein polyaryletherketone has a repeating unit as shown in the following formula 1: Formula 1; The thickness of the bottom layer along the conductor outward in a single direction is not greater than 10 μm; The outer insulating layer is a blended resin obtained by blending and granulating polyetheretherketone and phenolphthalein polyaryletherketone, wherein the mass ratio of the phenolphthalein polyaryletherketone in the outer insulating layer is not greater than 50%.

2. The insulated wire according to claim 1, wherein: The crystallinity of the blended resin of the outer insulating layer is not less than 10%.

3. The insulated wire according to claim 2, wherein: The crystallinity of the blended resin of the outer insulating layer is 20-28%.

4. A method for preparing an insulated wire according to any one of claims 1 to 3, characterized in that: The insulated wire is prepared by an extrusion method, which specifically comprises the following steps: After the bottom layer resin is heated to a temperature of 370-400°C to reach a molten state, the bottom layer resin material is extruded through the first flow channel of the screw extruder and evenly coated on the copper conductor to obtain a core wire. After the outer insulating layer resin material is heated to a temperature of 370-400°C to reach a molten state, the outer insulating layer resin material is extruded through the second flow channel of the screw extruder and evenly coated on the core wire, and the insulated wire is obtained after cooling.

5. A coil, characterized in that: The insulated wire is composed of any one of claims 1 to 3.

6. An electronic / electrical device, characterized in that: The invention comprises the coil as claimed in claim 5.

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