Stripping-resistant insulated cable and preparation method thereof

Abstract

The invention relates to the technical field of cable manufacturing, in particular to a stripping-resistant insulated cable and a preparation method thereof.Fluorine-containing polyaryletherketone resin PI-PAEK containing an imide side chain is adopted as a bonding layer outside a conductor, so that the bonding strength between a polyaryletherketone outer coating layer and a copper conductor is improved; the stripping-resistant insulating cable has the advantages that the stripping-resistant insulating cable is high in stripping resistance and can generate good compatibility with the polyaryletherketone outer coating layer, so that the integral coating layer outside the conductor forms a whole-layer structure with good compatibility, the bending and torsion performance of the stripping-resistant insulating cable can meet the requirements, meanwhile, the dielectric constant is smaller, the electrical insulation performance is better, and the requirements of vehicle cables can be met.

Description

Technical Field

[0001] The present invention relates to the technical field of cable manufacturing, and particularly relates to a peel-resistant insulated cable and a preparation method thereof. Background Art

[0002] Automotive cables mainly serve components such as vehicle generators, small in-vehicle motors, and electric motors and busbars of new energy vehicles. Due to its comprehensive advantages such as excellent temperature difference resistance performance, good flexibility, stable chemical properties, excellent electrical properties, outstanding dielectric strength, radiation resistance, insulation characteristics, and self-extinguishing function, polyether ether ketone (PEEK) material plays a key role in the early development stage of new products and fully meets the special requirements of oil-cooled electric motors. However, the adhesion of pure PEEK material is poor, and its compatibility with impregnating coatings is poor, making it difficult to adhere, which has become an obstacle to its application in the field of wires and cables.

[0003] The prior art such as patent CN111554443B provides a processing technology for PEEK magnet wires. In this technology, copper wires are coated and baked with polyamide-imide insulating paint of grade 220 or polyimide insulating paint of grade 240 for more than eighteen passes until the paint film reaches the specified thickness, and then a polyether ether ketone enameled wire is coated on the outside. This technology is relatively cumbersome and complex, and still requires expensive polyamide or polyamide-imide as an intermediate layer.

[0004] Therefore, developing a cable with a simple process, low cost, and good adhesion is the technical problem to be solved by the present invention. Summary of the Invention

[0005] In order to solve the above technical problems, a peel-resistant insulated cable and a preparation method thereof are provided. The present invention uses a fluorinated polyaryletherketone resin containing an imide side chain as a bonding layer outside the conductor, which improves the bonding strength between the polyaryletherketone outer coating layer and the copper conductor, and can have good compatibility with the polyaryletherketone outer coating layer, so that the overall coating layer outside the conductor forms a whole layer structure with better compatibility. The bending and torsion performance of the peel-resistant insulated cable of the present invention can meet the requirements, and it has good electrical insulation performance and can meet the requirements of automotive cables.

[0006] To achieve the above objectives, the present invention is realized through the following technical solutions:

[0007] A peel-resistant insulated cable includes a conductor, and a bonding layer and an outer coating layer provided outside the conductor;

[0008] Wherein the material of the bonding layer is a fluorinated polyaryletherketone resin containing an imide side chain, and the specific chemical structure is as follows:

[0009]

[0010] Further, the number-average molecular weight M of the fluorinated polyaryletherketone resin containing imide side chains n is between 15,000 g / mol and 30,000 g / mol, the weight-average molecular weight M w is between 35,000 g / mol and 120,000 g / mol, the molecular weight distribution index is between 1.8 and 2.6, and the melt viscosity at 400 °C is 90 Pa·s to 150 Pa·s. The synthesis method of this compound refers to Example 1 of the applicant's patent CN202411516988.7, and the preparation of this compound corresponding to the protection scope of this patent can obtain this compound within the corresponding above range.

[0011] Further, the material of the outer coating layer is polyaryletherketone, or a melt blend of polyaryletherketone and the fluorinated polyaryletherketone resin containing imide side chains. The proportion of polyetheretherketone in the melt blend is between 50 wt% and 100 wt%. Since the glass transition temperature of the fluorinated polyaryletherketone resin containing imide side chains is relatively high, about 185 °C, while the glass transition temperature of pure PEEK is 143 °C, blending the two can obtain a blend with a higher glass transition temperature, enabling the cable to be applied in higher temperature environments;

[0012] The polyaryletherketone is selected from one or more of polyetheretherketone (PEEK), polyetherketone (PEK), polyetherketoneketone (PEKK), polyetheretherketoneketone (PEEKK), and polyetherketoneetherketoneketone (PEKEKK).

[0013] Still further, the dielectric constant of the bonding layer at 25 °C is below 3.0, and the dielectric constant of the outer coating layer at 25 °C is below 3.5.

[0014] Still further, the thickness of the bonding layer is between 10 μm and 100 μm; the thickness of the outer coating layer is between 100 μm and 500 μm; the bonding layer and the outer coating layer can form an integral body.

[0015] The preparation method of the above-mentioned peel-resistant insulating cable includes the following steps:

[0016] Coat the bonding layer solution on the conductor by the multiple solution impregnation method, and after drying, form a bonding layer outside the conductor. Repeat or do not repeat the coating-drying operation until the bonding layer reaches the required thickness to obtain an intermediate product;

[0017] Then extrude and coat an outer coating layer outside the intermediate product by the extrusion coating method to obtain a peel-resistant insulating cable;

[0018] Wherein the bonding layer solution contains a fluorinated polyaryletherketone resin containing imide side chains;

[0019] Wherein, the material of the outer coating layer is polyaryletherketone or a melt blend of polyaryletherketone and the fluorinated polyaryletherketone resin containing imide side chains.

[0020] Furthermore, the mass percentage of the adhesive layer solution is at least 5%, preferably 10%-50%. The solvents for dissolving the fluorinated polyaryletherketone resin containing imide side chains are selected from one or more of DMF, DMAc, NMP, DMSO, CHCl 3 , THF.

[0021] Furthermore, in the extrusion coating method, a screw extruder is used to extrude the intermediate product, and the extrusion parameters are set as follows: the temperature of the feeding section of the screw extruder is 140-200°C along the extrusion direction, the temperatures of each zone in the melting section increase within the range of 250-420°C, the temperature of the metering section is within the range of 350-400°C, and the temperature of the die head is 370-400°C.

[0022] Beneficial technical effects:

[0023] In the present invention, the fluorinated polyaryletherketone resin PI-PAEK containing imide side chains is used as the adhesive layer outside the conductor, which improves the bonding strength between the polyaryletherketone outer coating layer and the copper conductor, and can have good compatibility with the polyaryletherketone outer coating layer, so that the overall coating layer outside the conductor forms a whole layer structure with better compatibility. The bending and torsion properties of the peel-resistant insulated cable of the present invention can meet the requirements. At the same time, the dielectric constant is smaller and the electrical insulation is better, which can meet the requirements of vehicle-use cables. Specific embodiments

[0024] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0025] Unless otherwise specifically stated, the numerical values set forth in these embodiments do not limit the scope of the present invention. Technologies and methods known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies and methods should be regarded as part of the specification. In all examples shown and discussed herein, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values.

[0026] In the following examples, the experimental methods without specific conditions are usually determined according to national standards; if there is no corresponding national standard, they are carried out according to general standard requirements or general methods.

[0027] In the following, polyaryletherketone is taken as an example of polyetheretherketone. PEEK is synthesized by Shandong Junhao High-Performance Polymer Co., Ltd., with a size of 200 mesh to 3 mm, a melt index of 5 to 16 g / 10 min (400 °C, 2.16 kg), and a melt viscosity of 120 to 410 Pa·s (400 °C). Its chemical structure is as follows:

[0028]

[0029] Preparation Example 1

[0030] The preparation method of the bisphenol AF type polyaryletherketone (PI-PAEK) with imide side groups used below can be found in the Chinese patent with the application number 202411516988.7 of Shandong Junhao High-Performance Polymer Co., Ltd. The preparation method of this polymer is described in detail in Example 1. Specifically, it is prepared by polycondensation of bisphenol AF containing two imide groups and 4,4'-difluorobenzophenone.

[0031] Specifically, bisphenol AF containing two imide groups is first synthesized. The chemical reaction process and the structure of bisphenol AF containing two imide groups are as follows:

[0032]

[0033] Then, the fluorinated polyaryletherketone with imide side chains (PI-PAEK) is produced. The chemical reaction process and the chemical structure of PI-PAEK are as follows:

[0034]

[0035] According to the polycondensation reaction temperature of 160 - 180 °C and the reaction time of 4 - 12 h, the number-average molecular weight M of the PI-PAEK prepared n is between 15000 g / mol and 30000 g / mol, the weight-average molecular weight M w is between 35000 g / mol and 120000 g / mol, the molecular weight distribution index is between 1.8 and 2.6, and the melt viscosity at 400 °C is 90 Pa·s to 150 Pa·s.

[0036] Using the PI-PAEK prepared with the polycondensation reaction temperature of 160 °C and the reaction time of 7 h in Example 1 of the Chinese patent with the application number 202411516988.7, its M n = 2.58×10 4 g / mol, M w = 5.7×104 g / mol, PDI = 2.21; T g = 185 °C, its tensile strength is 87 MPa, and the elongation at break reaches over 30%; it can be heated and dissolved in DMF, DMAc, NMP, and DMSO, and can be dissolved at room temperature in CHCl 3 , THF. The following examples use PI-PAEK with these parameters. Of course, in other examples, PI-PAEK with other parameters within the above range can also be used.

[0037] Example 1

[0038] A method for preparing a peel-resistant insulated cable, comprising the following steps:

[0039] S1. Preliminary preparation

[0040] Material drying: Bake PI-PAEK and PEEK at a temperature of 120 °C for 5 hours respectively;

[0041] Drawing step: Feed an oxygen-free copper rod with a diameter of 2.5 mm into a drawing box through a pay-off device. After multiple draws, reach the specified product specification (diameter 1 mm). Then, clean and blow dry the residual water stains on the wire surface, and then perform annealing treatment; during annealing, the temperature of the annealing furnace is 500 °C; the annealing temperature in the furnace is heated by electric heating tubes, and the temperature is monitored in real time by a thermocouple; steam is used to protect the copper rod in the annealing furnace, and the copper wire is cleaned again after annealing;

[0042] S2. Preparation of the bonding layer

[0043] Dissolve PI-PAEK with N,N-dimethylformamide to prepare a 25 wt% binder solution. Immerse and coat the copper wire treated in S1 with the binder solution, and then bake in a drying tunnel to remove the organic solvent, forming a PI-PAEK binder layer on the outer surface of the copper wire conductor. Repeat the immersion-baking process until the coated binder layer reaches a thickness of 30 μm to form an intermediate product; then wind the intermediate product onto a spool through a take-up device. There is no lubricant on the surface of the core wire before winding.

[0044] S3. Preparation of the outer coating layer

[0045] The parameters of the extruder are set as follows: along the extrusion direction, the feeding section temperature of the screw extruder is set at 160 °C, the temperatures of each zone in the melting section increase from 280 - 380 °C, the metering section temperature is 380 - 390 °C, and the die head temperature is 380 - 390 °C. After waiting for each section to reach the set temperature and maintaining the temperature for 30 minutes, load the PEEK resin. At the same time, unwind the intermediate product, and extrude and wrap the PEEK around the intermediate product. Since the temperature also reaches the melting temperature of the PI - PAEK adhesive layer, during the extrusion and wrapping process, the PI - PAEK adhesive layer and the PEEK outer coating form an integral layer due to their good compatibility. After cooling and winding, a peel - resistant insulated cable with the designed thickness is obtained.

[0046] Example 2

[0047] A method for preparing a peel - resistant insulated cable includes the following steps:

[0048] S1. The preliminary preparation is the same as in Example 1.

[0049] S2. Preparation of the adhesive layer

[0050] Use CHCl 3 Dissolve PI - PAEK to prepare a 35 wt% binder solution. Let the copper wire after S1 treatment be impregnated and coated with the binder solution, and then baked in a drying oven to remove the organic solvent, forming a PI - PAEK binder layer on the outer surface of the copper wire conductor. Repeat the impregnation - baking process until the coated binder layer reaches a thickness of 40 μm to form an intermediate product; then wind the intermediate product onto a spool through a take - up device, and there is no lubricant on the surface of the core wire before take - up.

[0051] S3. Preparation of the outer coating

[0052] The parameters of the extruder are set as follows: along the extrusion direction, the feeding section temperature of the screw extruder is set at 150 °C, the temperatures of each zone in the melting section increase from 300 - 390 °C, the metering section temperature is 390 - 400 °C, and the die head temperature is 390 - 400 °C. After waiting for each section to reach the set temperature and maintaining the temperature for 30 minutes, load the PEEK resin. At the same time, unwind the intermediate product, and extrude and wrap the PEEK around the intermediate product. Since the temperature also reaches the melting temperature of the PI - PAEK adhesive layer, during the extrusion and wrapping process, the PI - PAEK adhesive layer and the PEEK outer coating form an integral layer due to their good compatibility. After cooling and winding, a peel - resistant insulated cable with the designed thickness is obtained.

[0053] Example 3

[0054] A method for preparing a peel - resistant insulated cable includes the following steps:

[0055] S1. The preliminary preparation is the same as in Example 1.

[0056] S2. Preparation of the adhesive layer

[0057] Dissolve PI-PAEK in CHCl 3 Prepare a 45 wt% binder solution by dissolving PI-PAEK. Immerse and coat the copper wire after S1 treatment with the binder solution, and then bake it in a drying oven to remove the organic solvent, forming a PI-PAEK binder layer outside the copper wire conductor. Repeat the immersion-baking process until the coated binder layer reaches a thickness of 50 μm to form an intermediate product. Then, wind the intermediate product onto a spool through a take-up device. There is no lubricant on the surface of the core wire before taking up the wire.

[0058] S3. Preparation of the outer coating layer

[0059] Set the parameters of the extruder as follows: Set the temperature of the feeding section of the screw extruder at 180 °C along the extrusion direction, the temperatures of each zone in the melting section increase from 260 - 380 °C, the temperature of the metering section is 380 - 390 °C, and the temperature of the die head is 390 - 400 °C. After waiting for each section to reach the set temperature and maintaining for 30 minutes, feed the PEEK resin, and at the same time pay out the intermediate product, and extrude and wrap the PEEK outside the intermediate product. Since the temperature also reaches the melting temperature of the PI-PAEK binder layer, during the extrusion and wrapping process, the PI-PAEK binder layer and the PEEK outer coating layer form an integral layer due to their good compatibility. After cooling and winding, a peel-resistant insulated cable with the designed thickness is obtained.

[0060] Example 4

[0061] The preparation of this case is the same as that of Example 2, except that the material of the outer coating layer is a melt blend of PEEK and PI-PAEK, and the mass ratio of PEEK to PI-PAEK is 8:2. After mixing the two evenly, carry out melt blending extrusion granulation at 360 - 400 °C, and then extrude and wrap the melt blend outside the intermediate product to form an integral body.

[0062] Comparative Example 1

[0063] The preparation of this case is the same as that of Example 2, except that the material of the binder layer is hexafluorobisphenol A type polyaryletherketone (PAEK-AF), and the specific chemical structure is as follows:

[0064]

[0065] The preparation reference of this compound: "Synthesis and Characterization of Polyaryletherketone Containing Trifluoromethyl Group", Engineering Plastics Application [J], 2012, Vol. 40, No. 1, P73 - 76; the specific number average molecular weight M n of this compound is 34800 g / mol, PDI = 2.56, and the melt viscosity at 400 °C is 144 Pa·s.

[0066] Comparative Example 2

[0067] The preparation of this example is the same as that of Example 2, except that step S2 is not included, and a PEEK outer coating is directly extruded outside the copper wire conductor.

[0068] The above examples and comparative examples were subjected to performance tests, and the results are shown in Table 1.

[0069] Table 1 Product Performance of Examples and Comparative Examples

[0070]

[0071] As can be seen from Table 1, the present invention introduces a PI-PAEK binder layer with a low dielectric constant between the PEEK outer coating and the copper wire conductor. This layer has good adhesion to the copper wire. At the same time, it has good compatibility with PEEK and forms an integral body when the PEEK outer coating is extruded subsequently, improving the peel strength of the overall product, making the overall product have a good peel resistance effect, and the bending and torsion properties can meet the requirements. At the same time, the dielectric constant is smaller and the electrical insulation is better, which can meet the requirements of automotive insulation cables; in addition, due to the relatively high glass transition temperature of PI-PAEK, when it is blended with PEEK and used as the outer coating material, the cable can be applied in higher temperature usage scenarios, improving the service life of the insulation cable at high temperatures.

[0072] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A stripping-resistant insulated cable, characterized in that: It comprises a conductor, and a bonding layer and an outer coating layer arranged outside the conductor; The material of the bonding layer is a fluorinated polyaryletherketone resin containing imide side chains, and the specific chemical structure is as follows:

2. The stripping-resistant insulated cable according to claim 1, characterized in that: The number average molecular weight M of the fluorinated polyaryletherketone resin containing imide side chains is n Between 15000g / mol~30000g / mol, weight average molecular weight M w The molecular weight is between 35000 g / mol and 120000 g / mol, the molecular weight distribution index is between 1.8 and 2.6, and the melt viscosity at 400°C is between 90 Pa·s and 150 Pa·s.

3. The stripping-resistant insulated cable according to claim 2, characterized in that: The material of the outer coating layer is polyaryletherketone, or a melt blend of polyaryletherketone and the fluorine-containing polyaryletherketone resin containing imide side chains, wherein the polyetheretherketone accounts for 50wt%-100wt% in the melt blend; The polyaryletherketone is selected from one or more of polyetheretherketone, polyetherketone, polyetherketoneketone, polyetheretherketoneketone, and polyetherketoneetherketoneketone.

4. The stripping-resistant insulated cable according to claim 3, characterized in that: The dielectric constant of the bonding layer at 25° C. is less than 3.0, and the dielectric constant of the outer coating layer at 25° C. is less than 3.

5.

5. The stripping-resistant insulated cable according to any one of claims 1 to 4, characterized in that: The thickness of the bonding layer is between 10 μm and 100 μm; the thickness of the outer coating layer is between 100 μm and 500 μm; the bonding layer and the outer coating layer can form a whole.

6. A method for preparing a stripping-resistant insulated cable according to any one of claims 1 to 5, characterized in that: The steps include: The conductor is coated with a bonding layer solution by multiple solution dipping method, and after drying, a bonding layer is formed on the outside of the conductor, and the coating-drying operation is repeated or not until the bonding layer reaches a desired thickness to obtain an intermediate product; Then, an outer coating layer is extruded on the outside of the intermediate product by an extrusion coating method, so as to obtain a peeling-resistant insulated cable; The bonding layer solution contains a fluorine-containing polyaryletherketone resin containing imide side chains; The material of the outer coating layer is polyaryletherketone, or a melt blend of polyaryletherketone and the fluorine-containing polyaryletherketone resin containing imide side chains.

7. The method for preparing a stripping-resistant insulated cable according to claim 6, characterized in that: The mass percentage of the bonding layer solution is at least 5%, preferably 10%-50%, and the solvent for dissolving the fluorinated polyaryletherketone resin containing imide side chains is selected from one or more of DMF, DMAc, NMP, DMSO, CHCl3, and THF.

8. The method for preparing a stripping-resistant insulated cable according to claim 6, characterized in that: The extrusion coating method uses a screw extruder to extrude the intermediate product, and the extrusion parameters are set as follows: the feed section temperature of the screw extruder is set at 140-200°C along the extrusion direction, the temperature of each zone in the melting section increases gradually within the range of 250-420°C, the temperature of the metering section is within the range of 350-400°C, and the head die temperature is 370-400°C.

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