Friction-resistant and corrosion-resistant varnished wire varnishing method

Abstract

The invention relates to the technical field of varnished wires, in particular to a varnishing method for a friction-resistant and corrosion-resistant varnished wire, which comprises the following steps of: enabling a wrapped fiber copper wire to pass through a heating water tank filled with sodium hydroxide, a silane coupling agent and lauric acid at a constant speed, and then drying at a low temperature under negative pressure; the preparation method comprises the following steps: mixing polyester-imide resin, diisocyanate and composite functional powder, adding the mixture into an organic solvent added with a catalyst to prepare composite paint, and loading the composite paint into a painting tank; and the treated copper wires wrapped with the fibers pass through a varnishing groove, are cured through a constant-temperature box and then are dried and packaged after passing through water vapor. According to the invention, the polymer grid integrated structure is formed on the surface of the wrapping fiber, the composite functional powder is packaged in the grid, the fiber and polymer grid integrated structure enables the enameled wire to have friction resistance and aging resistance, and the composite functional powder packaged in the grid improves the corrosion resistance of the enameled wire.

Description

Technical Field

[0001] The invention relates to the technical field of enameled wires, and in particular to a method for painting friction-resistant and corrosion-resistant enameled wires. Background Art

[0002] Enameled wire is a conductor coated with insulating paint on the outside of the conductor and used to wind the coil. Friction-resistant enameled wire should be subjected to friction during production or use, such as friction when winding or inserting into the motor slot, so better wear resistance is required. During service, corrosion is inevitable due to the relatively complex environment, so the enameled wire is required to have long-term corrosion resistance while being friction-resistant.

[0003] The preparation of friction-resistant and corrosion-resistant enameled wire includes three aspects: material selection, process improvement and surface treatment. Material selection, such as using high-strength, heat-resistant and aging-resistant insulating paints such as polyurethane and polyesterimide; process improvement, such as multi-layer coating, or increasing the thickness of the coating, but too thick may cause problems, such as affecting heat dissipation or flexibility; surface treatment, such as adding lubricants or nanomaterials to improve surface smoothness, reduce friction coefficient, or add materials with anti-corrosion factors; in addition, there are curing processes, such as high-temperature curing, to make the paint film denser and the structure more stable.

[0004] According to the principle that properties determine applications, improvements to the polymer paint itself to give the enameled wire additional friction and corrosion resistance have limited effect, and functional components must be added, usually powder particles. Particulate matter will reduce the continuity of the polymer paint and reduce other properties of the enameled wire. Therefore, the negative impact of the introduced functional substances on the enameled wire should be avoided as much as possible. Summary of the invention

[0005] In view of the above problems existing in the existing polyamide enameled wire, the present invention provides a method for painting a friction-resistant and corrosion-resistant enameled wire, comprising the following steps: 1. Modified copper wire outer fiber The outer fiber copper wire is passed through a heated water tank filled with sodium hydroxide, silane coupling agent and lauric acid, and then dried at low temperature under negative pressure at a uniform speed, and rolled up for use; 2. Preparation of composite paint The polyester imide resin, diisocyanate and composite functional powder are mixed, added into an organic solvent with a catalyst, and a composite paint with a solid content of 35-45% is prepared, and the composite paint is loaded into the paint tank of the enameled wire production line; 3. Winding and painting The outer fiber copper wire treated in step 1 is passed through the paint tank in step 2, and after being painted, it is cured in a constant temperature box; 4. Finalized packaging The painted outer fiber copper wire cured in step 3 is passed through steam and then dried and rolled.

[0006] Furthermore, the diameter of the copper wire used in the present invention is 0.2-2 mm, and the outer fiber of the copper wire is one of nylon fiber, aramid fiber or polyacrylonitrile fiber. The outer fiber can be coated on the copper wire using existing enameled wire technology, such as nylon outer coated copper enameled wire.

[0007] Furthermore, in step 1, the concentration of sodium hydroxide is 5wt%~20wt%, and the weight ratio of sodium hydroxide, silane coupling agent and lauric acid is 100:(10~30):(5~15); the heating temperature of the water tank is 40~70°C; the negative pressure is 10~100Pa, and the low-temperature drying temperature is 30~40°C.

[0008] Further, in step 2, the composite functional powder has a particle size of 100-500 nm and is composed of the following components: 10-50 parts of aluminum oxide, 5-30 parts of titanium dioxide, 5-20 parts of silicon nitride and 0-15 parts of talc; the diisocyanate is one of MDI, TDI, HDI and HMDI; the weight ratio of polyesterimide resin, diisocyanate and composite functional powder is 100:(20-30):(5-8); the catalyst is an organic tin catalyst, and the organic solvent is one of DMSO, DMAc, N-methyl-2-pyrrolidone, 2-butanol or methyl acetate.

[0009] Furthermore, in step three, the temperature of the thermostat is 45-65°C.

[0010] Compared with the existing nylon enameled wire, the special feature of the present invention is that the outer fiber of the copper wire is first modified to release the amino and hydroxyl groups on the fiber surface. After passing through the paint tank, the polyesterimide resin, diisocyanate and composite functional powder will be evenly attached to the fiber surface and penetrate into the fiber gaps. When passing through the constant temperature box, under the action of the catalyst, the polyesterimide resin and diisocyanate will react to form polyurethane. At the same time, the diisocyanate will react with the amino or hydroxyl groups on the fiber surface and then graft the polyesterimide resin. Finally, a polymer grid integrated structure is formed on the surface of the outer fiber, and the composite functional powder is encapsulated in the grid. The fiber and polymer grid integrated structure makes the enameled wire have friction resistance and anti-aging performance. The composite functional powder encapsulated in the grid increases the diffusion resistance of the corrosion factor and improves the corrosion resistance of the enameled wire. DETAILED DESCRIPTION

[0011] The present invention is described below in conjunction with examples, which are only used to explain the present invention and are not used to limit the scope of the present invention.

[0012] Example 1 A method for painting a friction-resistant and corrosion-resistant nylon 66 coated copper enameled wire comprises the following steps: 1. Pass the nylon 66 copper wire wrapped with 20D / 10F through a heating water tank filled with 100 parts by weight of sodium hydroxide, 20 parts by weight of silane coupling agent and 10 parts by weight of lauric acid, control the concentration of sodium hydroxide to 18wt%, the temperature of the water tank to 60°C, pass through at a uniform speed of 0.5m / s, dry at 40°C under 100Pa, and roll for use; 2. Take 30 parts by weight of aluminum oxide, 18 parts by weight of titanium dioxide, 12 parts by weight of silicon nitride and 10 parts by weight of talc, all of which have a particle size of 100 nm, mix them evenly to obtain a composite functional powder, mix the polyester imide resin, MDI and the composite functional powder evenly at a weight ratio of 100:25:6, add them to DMSO added with an organic tin catalyst, and prepare a composite paint with a solid content of 45%, and load the composite paint into the paint tank of the enameled wire production line; 3. The outer nylon 66 copper wire treated in step 1 is passed through the paint tank of step 2, and after painting, it is passed through a constant temperature box at 60°C for 30 minutes. After curing, it is passed through water vapor, dried, and rolled.

[0013] Example 2 A method for painting a friction-resistant and corrosion-resistant aramid-coated copper enameled wire, comprising the following steps: 1. Pass the aramid copper wire with a monofilament fineness of 2D through a heating water tank filled with 100 parts by weight of sodium hydroxide, 30 parts by weight of silane coupling agent and 15 parts by weight of lauric acid, control the concentration of sodium hydroxide to be 10wt%, the temperature of the water tank to be 40°C, pass through at a uniform speed of 0.8m / s, dry at 30°C under 50Pa, and roll for use; 2. Take 50 parts by weight of aluminum oxide, 5 parts by weight of titanium dioxide and 5 parts by weight of silicon nitride, all with a particle size of 200 nm, mix them evenly to obtain a composite functional powder, mix polyester imide resin, TDI and the composite functional powder at a weight ratio of 20:4:1, add them to N-methyl-2-pyrrolidone added with an organic tin catalyst, and prepare a composite paint with a solid content of 35%, and load the composite paint into the paint tank of the enameled wire production line; 3. The outer-wrapped aramid copper wire treated in step 1 is passed through the painting tank in step 2, and after painting, it is passed through a constant temperature box at 45° C. for 40 minutes. After curing, it is passed through water vapor, dried, and rolled.

[0014] Example 3 A method for painting a friction-resistant and corrosion-resistant polyacrylonitrile coated copper enameled wire comprises the following steps: 1. Pass the polyacrylonitrile copper wire with a monofilament fineness of 2.5D through a heating water tank filled with 100 parts by weight of sodium hydroxide, 10 parts by weight of silane coupling agent and 5 parts by weight of lauric acid, control the concentration of sodium hydroxide to 5wt%, the temperature of the water tank to 70°C, pass through at a uniform speed of 0.3m / s, dry at 35°C under 10Pa, and roll for use; 2. Take 10 parts by weight of aluminum oxide, 30 parts by weight of titanium dioxide, 20 parts by weight of silicon nitride and 15 parts of talc, all with a particle size of 500 nm, mix them evenly to obtain a composite functional powder, mix the polyester imide resin, HDI and the composite functional powder at a weight ratio of 50:15:4, add them to DMAc with an organic tin catalyst added, and prepare a composite paint with a solid content of 40%, and load the composite paint into the paint tank of the enameled wire production line; 3. The polyacrylonitrile copper wire treated in step 1 is passed through the paint tank of step 2, and then passed through a constant temperature box at 65°C for 25 minutes. After curing, it is passed through water vapor, dried, and rolled.

[0015] Comparative Examples 1 to 3 are the fiber-coated copper bonding wires in step 1 of Examples 1 to 3, respectively.

[0016] Table 1 shows the performance test of the enameled wires obtained in Examples 1 to 3 and Comparative Examples 1 to 3. From the data in the table, it can be seen that the enameled wires in Examples 1 to 3 have obvious improvements in salt spray resistance, abrasion resistance and tensile properties.

[0017] Table 1. Performance test of enameled wires of Examples 1 to 3 and Comparative Examples 1 to 3 Salt spray test level Wear resistance (relative brightness) Breaking strength Example 1 Level 8 23.76% 568MPa Comparative Example 1 Level 3 35.13% 435MPa Example 2 Level 8 16.35% 793MPa Comparative Example 2 Level 3 24.67% 608MPa Example 3 Level 8 27.92% 512MPa Comparative Example 3 Level 3 39.74% 429MPa Note: 1. The diameter of the copper wire is 1.5 mm, and the fiber coating is 6% of the weight of the copper wire. 2. The wear resistance test standard is GB / T 21196, and the number of frictions is 5000 times.

[0018] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for painting a friction-resistant and corrosion-resistant enameled wire, characterized in that: The following steps are involved:

1. Modified copper wire outer fiber The outer fiber copper wire is passed through a heated water tank filled with sodium hydroxide, silane coupling agent and lauric acid, and then dried at low temperature under negative pressure at a uniform speed, and rolled up for use; 2. Preparation of composite paint The polyester imide resin, diisocyanate and composite functional powder are mixed, added into an organic solvent with a catalyst, and a composite paint with a solid content of 35-45% is prepared, and the composite paint is loaded into the paint tank of the enameled wire production line; 3. Winding and painting The outer fiber copper wire treated in step 1 is passed through the paint tank in step 2, and after being painted, it is cured in a constant temperature box; 4. Finalized packaging The copper wire wrapped around the lacquered fiber cured in step 3 is passed through steam and then dried and rolled.

2. The method according to claim 1, characterized in that The diameter of the copper wire is 0.2-2 mm, and the outer covering fiber is one of nylon fiber, aramid fiber or polyacrylonitrile fiber.

3. The method according to claim 2, characterized in that In step 1, the concentration of sodium hydroxide is 5wt%~20wt%, and the weight ratio of sodium hydroxide, silane coupling agent and lauric acid is 100:(10~30):(5~15); the heating temperature of the water tank is 40~70°C; the negative pressure is 10~100Pa, and the low-temperature drying temperature is 30~40°C.

4. The method according to claim 2, characterized in that: In step 2, the composite functional powder has a particle size of 100-500 nm and is composed of the following components: 10-50 parts of aluminum oxide, 5-30 parts of titanium dioxide, 5-20 parts of silicon nitride and 0-15 parts of talc; the diisocyanate is one of MDI, TDI, HDI and HMDI; the weight ratio of polyesterimide resin, diisocyanate and composite functional powder is 100:(20-30):(5-8); the catalyst is an organic tin catalyst, and the organic solvent is one of DMSO, DMAc, N-methyl-2-pyrrolidone, 2-butanol or methyl acetate.

5. The method according to claim 2, characterized in that: In step 3, the temperature of the thermostat is 45~65℃.