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, including 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, soluble polytetrafluoroethylene 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, PFA is mixed into the outer insulating layer PEEK, which can improve the flexibility of the outer insulating layer on the one hand, and can also enhance the dielectric properties at high temperatures.

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 to 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. On the other hand, in an environment above 200°C, the dielectric constant of PEEK resin will show an upward trend with the increase of operating temperature, resulting in a decrease in its insulation performance. Summary of the invention

[0003] In view of this, the 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, and to improve the high temperature dielectric properties.

[0004] To achieve the above object, the technical solution of the present invention is as follows:

[0005] The structure of the phenolphthalein polyaryletherketone has a repeating unit as shown in the following formula 1:

[0006]

[0007] Formula 1.

[0008] The phenolphthalein polyaryletherketone can 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.

[0009] 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 catalytic 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.

[0010] 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.

[0011] In the present invention, along the unilateral direction outward from the conductor, the thickness of the bottom layer is not greater than 10 μm, and preferably, the thickness of the bottom layer is 5-10 μm.

[0012] In order to improve the high temperature dielectric properties of the material, the present invention further adds soluble polytetrafluoroethylene (Polyfluoroalkoxy, PFA for short) into the outer insulating layer.

[0013] In a specific embodiment of the present invention, the outer insulating layer is made of a blend of PEEK and PFA, wherein the mass ratio of PEEK to PFA is 90:10 to 10:90.

[0014] In another embodiment of the present invention, the outer insulating layer further comprises PEK-C, wherein the mass ratio of PEK-C in the outer insulating layer is 2-10%. In this case, in the blended resin of the outer insulating layer, preferably, the total mass ratio of PEEK and PEK-C is 10%-90%.

[0015] In the present invention, adding PFA and / or PEK-C can reduce the crystallinity of the outer insulating layer. The crystallinity of the mixed resin of the outer insulating layer of the present invention is 3-35%.

[0016] 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:

[0017] After the bottom layer resin is heated to a temperature of 370-400°C to reach a molten state, the PEK-C resin material is extruded through the first flow channel of the screw extruder and evenly coated on the copper conductor to obtain core wire one, and the outer insulating layer resin material is heated to a temperature of 370-400°C to reach a molten state, and then the outer insulating layer resin material is extruded through the second flow channel of the screw extruder and evenly coated on the core wire one to obtain core wire two. After the core wire two is cooled, an insulated wire is obtained.

[0018] A third object of the present invention is to provide a coil composed of the above-mentioned insulated wire.

[0019] The present invention also aims to provide an electrical or electronic device prepared from the coil.

[0020] 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.

[0021] 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.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 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 breakage; at the same time, PFA is mixed into the outer insulating layer PEEK, which improves the high-temperature dielectric properties of PEEK on the one hand, while reducing the overall crystallinity of the outer insulating layer and improving the flexibility of the wire. In addition, PEK-C is further added to the outer insulating layer, which improves the adhesion and compatibility between the outer insulating layer and the bottom layer, and reduces the friction coefficient of the outer insulating layer, making it easier for the coil to be inserted into the stator. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural diagram of a mold used for processing an insulated wire in the present invention.

[0025] Figure 2 It is a schematic diagram of the side cross-sectional structure of the insulated wire in the present invention.

[0026] In the figure,

[0027] 1. Mold core; 2. Conductor conveying channel; 3. First flow channel; 4. Second flow channel; a. Inclined section; b. Horizontal section.

[0028] 10. Conductor; 20. Bottom layer; 30. Outer insulation layer. DETAILED DESCRIPTION

[0029] 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.

[0030] 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.

[0031] 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 longitudinal cross-sections of the first flow channel 3 and the second flow channel 4 are trumpet-shaped, including a flow channel inclined section a and a horizontal section b parallel to the conductor conveying channel 2. 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 of the first flow channel 3, and then flows out through the horizontal section of the first flow channel 3, and is coated on the outer periphery of the conductor 10 to form a 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 of the second flow channel 4, and then flows out through the horizontal section of the second flow channel 4, and is coated on the outer periphery of the bottom layer 20 to form an outer insulating layer 30 of the insulated wire, and the insulated wire is formed after cooling. Specifically, when the outer insulating layer is a blend of PEEK and PFA, PEEK and PFA are blended at 370-400°C through a twin-screw extruder to form a uniform mixed system, which is then granulated into a particle polymer material by a pelletizer after cooling. When the outer insulating layer is a blend of PEEK, PFA and PEK-C, the three resins of PEEK, PFA and PEK-C are blended at a certain mass ratio through a twin-screw extruder at 370-400°C to form a uniform mixed system, which is then granulated into a particle polymer material by a pelletizer after cooling.

[0032] Example 1

[0033] 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 insulating layer includes two layers, namely a bottom layer and an outer insulating layer. Among them, the metal conductor is a 1.50ⅹ2.20mm metal flat wire. The material of the bottom layer in contact with the conductor is phenolphthalein polyaryletherketone (PEK-C). The material of the outer insulating layer is prepared from a blend of polyetheretherketone (PEEK) and PFA, and the content of PFA in the blend is 10% by weight, and the rest is PEEK. Conductor preheating temperature: 280-330℃; PEK-C extrusion temperature: 370-400℃; outer insulating layer extrusion temperature: 370-400℃. The thickness of the bottom layer is 10μm, the thickness of the outer insulating layer is 120μm, and the total thickness of the insulating layer is 130μm.

[0034] Example 2

[0035] An insulated wire was prepared by the method of Example 1, wherein the content of PFA in the outer insulating layer blend was 20% by weight, and the rest was PEEK. The thickness of the bottom layer was 8 μm, the thickness of the outer insulating layer was 102 μm, and the total thickness of the insulating layer was 110 μm.

[0036] Example 3

[0037] An insulated wire was prepared by the method of Example 1, wherein the content of PFA in the outer insulating layer blend was 30% by weight, and the rest was PEEK. The thickness of the bottom layer was 10 μm, the thickness of the outer insulating layer was 140 μm, and the total thickness of the insulating layer was 150 μm.

[0038] Example 4

[0039] An insulated wire was prepared by the method of Example 1, wherein the content of PFA in the outer insulating layer blend was 40% by weight, and the rest was PEEK. The thickness of the bottom layer was 10 μm, the thickness of the outer insulating layer was 120 μm, and the total thickness of the insulating layer was 130 μm.

[0040] Example 5

[0041] An insulated wire was prepared by the method of Example 1, wherein the content of PFA in the outer insulating layer blend was 50% by weight, and the rest was PEEK. The thickness of the bottom layer was 10 μm, the thickness of the outer insulating layer was 120 μm, and the total thickness of the insulating layer was 130 μm.

[0042] Example 6

[0043] An insulated wire was prepared by the method of Example 1, wherein the content of PFA in the outer insulating layer blend was 60% by weight, and the rest was PEEK. The thickness of the bottom layer was 10 μm, the thickness of the outer insulating layer was 120 μm, and the total thickness of the insulating layer was 130 μm.

[0044] Example 7

[0045] An insulated wire was prepared by the method of Example 1, wherein the content of PFA in the outer insulating layer blend was 70% by weight, and the rest was PEEK. The thickness of the bottom layer was 10 μm, the thickness of the outer insulating layer was 120 μm, and the total thickness of the insulating layer was 130 μm.

[0046] Example 8

[0047] An insulated wire was prepared by the method of Example 1, wherein the content of PFA in the outer insulating layer blend was 80% by weight, and the rest was PEEK. The thickness of the bottom layer was 10 μm, the thickness of the outer insulating layer was 120 μm, and the total thickness of the insulating layer was 130 μm.

[0048] Example 9

[0049] An insulated wire was prepared by the method of Example 1, wherein the content of PFA in the outer insulating layer blend was 90% by weight, and the rest was PEEK. The thickness of the bottom layer was 10 μm, the thickness of the outer insulating layer was 120 μm, and the total thickness of the insulating layer was 130 μm.

[0050] Example 10

[0051] An insulated wire is prepared by the method of Example 1, and the material of the outer insulating layer is prepared from a blend of polyetheretherketone (PEEK), PFA and PEK-C. The content of PFA in the outer insulating layer blend is 10% by weight, the content of PEK-C is 2% by weight, and the rest is PEEK. Conductor preheating temperature: 280-330°C; PEK-C extrusion temperature: 370-400°C; outer insulating layer extrusion temperature: 370-400°C. The thickness of the PEK-C bottom layer is 10μm, the thickness of the outer insulating layer is 120μm, and the total thickness of the insulating layer is 130μm.

[0052] Embodiment 11

[0053] An insulated wire was prepared by the method of Example 10, wherein the content of PFA in the outer insulating layer blend was 20% by weight, the content of PEK-C was 3% by weight, and the rest was PEEK. The thickness of the PEK-C bottom layer was 8 μm, the thickness of the outer insulating layer was 102 μm, and the total thickness of the insulating layer was 110 μm.

[0054] Example 12

[0055] An insulated wire was prepared by the method of Example 10, wherein the content of PFA in the outer insulating layer blend was 30% by weight, the content of PEK-C was 4% by weight, and the rest was PEEK. The thickness of the PEK-C bottom layer was 10 μm, the thickness of the outer insulating layer was 140 μm, and the total thickness of the insulating layer was 150 μm.

[0056] Embodiment 13

[0057] An insulated wire was prepared by the method of Example 10, wherein the content of PFA in the outer insulating layer blend was 40% by weight, the content of PEK-C was 5% by weight, and the rest was PEEK. The thickness of the PEK-C bottom layer was 10 μm, the thickness of the outer insulating layer was 120 μm, and the total thickness of the insulating layer was 130 μm.

[0058] Embodiment 14

[0059] An insulated wire was prepared by the method of Example 10, wherein the content of PFA in the outer insulating layer blend was 50% by weight, the content of PEK-C was 6% by weight, and the rest was PEEK. The thickness of the PEK-C bottom layer was 10 μm, the thickness of the outer insulating layer was 120 μm, and the total thickness of the insulating layer was 130 μm.

[0060] Embodiment 15

[0061] An insulated wire was prepared by the method of Example 10, wherein the content of PFA in the outer insulating layer blend was 60% by weight, the content of PEK-C was 7% by weight, and the rest was PEEK. The thickness of the PEK-C bottom layer was 10 μm, the thickness of the outer insulating layer was 120 μm, and the total thickness of the insulating layer was 130 μm.

[0062] Example 16

[0063] An insulated wire was prepared by the method of Example 10, wherein the content of PFA in the outer insulating layer blend was 70% by weight, the content of PEK-C was 8% by weight, and the rest was PEEK. The thickness of the PEK-C bottom layer was 10 μm, the thickness of the outer insulating layer was 120 μm, and the total thickness of the insulating layer was 130 μm.

[0064] Embodiment 17

[0065] An insulated wire was prepared by the method of Example 10, wherein the content of PFA in the outer insulating layer blend was 80% by weight, the content of PEK-C was 10% by weight, and the rest was PEEK. The thickness of the PEK-C bottom layer was 10 μm, the thickness of the outer insulating layer was 120 μm, and the total thickness of the insulating layer was 130 μm.

[0066] Embodiment 18

[0067] An insulated wire was prepared by the method of Example 10, wherein the content of PFA in the outer insulating layer blend was 90% by weight, the content of PEK-C was 9% by weight, and the rest was PEEK. The thickness of the PEK-C bottom layer was 10 μm, the thickness of the outer insulating layer was 120 μm, and the total thickness of the insulating layer was 130 μm.

[0068] Comparative Example 1

[0069] An insulated wire was prepared by the method of Example 1, wherein the content of PFA in the outer insulating layer blend was 95% by weight, and the rest was PEEK. The thickness of the bottom layer was 10 μm, the thickness of the outer insulating layer was 120 μm, and the total thickness of the insulating layer was 130 μm.

[0070] Comparative Example 2

[0071] An insulated wire was prepared by the method of Example 1, wherein the outer insulating layer was PEEK, the thickness of the bottom layer was 10 μm, the thickness of the outer insulating layer was 120 μm, and the total thickness of the insulating layer was 130 μm.

[0072] Comparative Example 3

[0073] An insulated wire was prepared by the method of Example 1, wherein the outer insulating layer was PFA, the thickness of the bottom layer was 10 μm, the thickness of the outer insulating layer was 120 μm, and the total thickness of the insulating layer was 130 μm.

[0074] Comparative Example 4

[0075] An insulated wire was prepared by the method of Example 1, wherein the content of PFA in the outer insulating layer blend was 10% by weight, and the rest was PEEK. No bottom layer was provided, and the outer insulating layer was directly extruded onto the metal conductor. The thickness of the outer insulating layer was 130 μm, and the total thickness of the insulating layer was 130 μm.

[0076] Comparative Example 5

[0077] An insulated wire was prepared by the method of Example 10, wherein the outer insulating layer blend did not contain PFA, the content of PEK-C was 2% by weight, and the rest was PEEK. The thickness of the PEK-C bottom layer was 10 μm, the thickness of the outer insulating layer was 120 μm, and the total thickness of the insulating layer was 130 μm.

[0078] Comparative Example 6

[0079] An insulated wire was prepared by the method of Example 10, wherein the outer insulating layer was composed of PFA, the thickness of the PEK-C bottom layer was 10 μm, the thickness of the outer insulating layer was 120 μm, and the total thickness of the insulating layer was 130 μm.

[0080] Comparative Example 7

[0081] An insulated wire was prepared by the method of Example 10, wherein the PFA content in the outer insulating layer blend was 10% by weight, the PEK-C content was 2% by weight, and the remainder was PEEK. No bottom layer was provided, and the outer insulating layer was directly extruded onto the metal conductor. The thickness of the outer insulating layer was 130 μm, and the total thickness of the insulating layer was 130 μm.

[0082] Performance Testing

[0083] The following tests were performed on the insulated wires prepared in Examples 1-9 and Comparative Examples 1-7:

[0084] 1. Adhesion test

[0085] The adhesion test method provided by IEC-60851-3 2019 Test Method 8 is used for testing. The specific steps are as follows:

[0086] 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.

[0087] 2. Flexibility test

[0088] The insulated wires of the embodiments and comparative examples were tested for flexibility according to the following methods.

[0089] 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:

[0090] Take two 500mm long straight insulated wires, bend them 180±2° around a polished test core, one for flat winding (core diameter = 1 times wire thickness), the other for vertical winding (core diameter = 1 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".

[0091] 3. Insulation breakdown voltage test

[0092] The insulation breakdown voltage is tested using the breakdown voltage test method provided by IEC60851-5 2019 test method 13. The specific steps are as follows:

[0093] Remove the insulation from one end of the insulated wire, bend it flat on a round rod with a diameter of 1 times the wire width, and put it into a metal steel ball container with a thickness of at least 5mm. The end of the sample should extend long enough to avoid flashover. Apply the test voltage between the conductor and the metal steel ball. Boost the voltage at a boost speed of 500V / s and a leakage current of 5mA. Test 5 times and take the average value as the insulation breakdown voltage.

[0094] Table 1. Properties of composite wires made of PEK-C bottom layer and PEEK and PFA mixture outer insulation layer

[0095]

[0096] The metal conductor is 1.5ⅹ2.2mm metal flat wire.

[0097] Table 2. Composite wire properties of PEK-C bottom layer and PEEK, PFA and PEK-C mixture outer insulation layer

[0098]

[0099] The metal conductor is 1.5ⅹ2.2mm metal flat wire.

[0100] It can be seen from the above examples that PEK-C can improve the adhesion between the outer insulating layer and copper. The thickness of the bottom layer needs to be controlled below 10um. If the bottom layer is too thick, the adhesion will decrease. PFA is added to PEEK to improve the dielectric properties at high temperatures. PFA is introduced to reduce the crystallinity of the mixed resin, and PFA has good crack resistance. PEEK has too much rigidity, and adding PFA can prevent cracks from occurring.

[0101] 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.

[0102] 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.

[0103] 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; and the outer insulating layer is made of a mixed material comprising PEEK and PFA; The thickness of the bottom layer along the conductor outward in a single direction is not greater than 10 μm; The outer insulating layer further comprises PEK-C; Among them, the mass ratio of PEK-C in the outer insulation layer is 2~10%; The total mass proportion of the PEEK and PEK-C is 10% to 90%.

2. The insulated wire according to claim 1, wherein: The crystallinity of the mixed resin of the outer insulating layer is 3-35%.

3. The method for preparing the insulated wire according to any one of claims 1 to 2, 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 PEK-C resin material is extruded through the first flow channel of the screw extruder and evenly coated on the copper conductor to obtain core wire one, and the outer insulating layer resin material is heated to a temperature of 370-400°C to reach a molten state, and then the outer insulating layer resin material is extruded through the second flow channel of the screw extruder and evenly coated on the core wire one to obtain core wire two. After the core wire two is cooled, an insulated wire is obtained.

4. A coil, characterized in that: The insulated wire is composed of any one of claims 1 to 2.

5. An electronic / electrical device, characterized in that: The invention comprises the coil as claimed in claim 4.

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