Direct-weldable polyurethane enameled copper flat wire and preparation process therefor

Abstract

The present invention belongs to the technical field of enameled copper flat wires, and relates to a direct-weldable polyurethane enameled copper flat wire and a preparation process therefor. In the present invention, by means of adding a rare-earth element, halloysite nanotubes, silicon carbide and graphene, a polyurethane paint in an intermediate layer is modified, and the performance of the polyurethane paint in the intermediate layer is thus effectively improved. By means of adding the rare-earth element, grains of the polyurethane paint can be refined, such that the polyurethane paint can be better coated on a copper flat wire; adding the halloysite nanotubes enables a polymer to form a network structure, such that the polyurethane paint has better mechanical strength; and adding silicon carbide and graphene further improves the mechanical strength of the polyurethane paint, also enhances the barrier properties of the polyurethane paint, and reduces the permeation of external substances, such as moisture and oxygen, to the polyurethane paint, thereby contributing to improving the oxidation resistance of the polyurethane paint.

Description

A straight soldering polyurethane enameled copper flat wire and a preparation process thereof TECHNICAL FIELD

[0001] The present application belongs to the technical field of enameled copper flat wire, and relates to a straight soldering polyurethane enameled copper flat wire and a preparation process thereof. BACKGROUND

[0002] At present, the polyurethane enameled copper flat wire widely used in household appliances, precision instruments, telecommunications and instruments adopts ordinary polyurethane paint, has straight soldering property, good high-frequency resistance, easy coloring, good moisture resistance, but poor mechanical strength and heat resistance, and poor flexibility and adhesion in production of large-size wires, so that the product is mostly small-size round wires with a diameter of less than 2.00 mm; and the coating process of the previous polyurethane enameled copper flat wire adopts felt coating, which has the defects that the paint film thickness between wires is not easy to be consistent; high-viscosity insulating paint cannot be used, solvent consumption is large, the coating felt is baked by high temperature at the lower furnace mouth, which causes the felt to age and shorten the service life, the operation skill requirement is high, and the product quality consistency is poor.

[0003] In addition, the existing ordinary enameled copper flat wire mostly contains only one insulating layer, and a skeleton is needed for fixing and forming during the manufacture of coils, and the enameled copper flat wire has poor folding resistance, voltage resistance, wear resistance and heat resistance, the paint film is easy to break, cannot be directly used for soldering, has insufficient lubricity, is easy to cause mechanical damage during processing, and causes the performance of the processed product to change, and is commonly used in ordinary motors, electrical appliances, instruments, transformers and the like, but is not suitable for high-tech computer display, color TV picture tube deflection coil, high-frequency inductor high-frequency coil, telecommunications winding, high-speed variable frequency motor and the like, and cannot meet the requirements of the telecommunications and electronic industries.

[0004] Therefore, the polyurethane paint is modified to solve the above problems, the mechanical strength is improved, and a layer of thermosetting polyamide resin paint is added to the outer layer to further improve the mechanical strength of the enameled copper flat wire. SUMMARY

[0005] The present application aims to provide a straight soldering polyurethane enameled copper flat wire and a preparation process thereof, which has the characteristics of high mechanical strength and is not easy to age.

[0006] The object of the present application can be achieved by the following technical solutions:

[0007] A straight soldering polyurethane enameled copper flat wire, the straight soldering polyurethane enameled copper flat wire comprises an internal copper round wire, a middle layer of modified polyurethane paint and an outer layer of thermosetting polyamide resin paint, wherein the preparation method process of the middle layer of modified polyurethane paint is as follows,

[0008] S1: 20~30% of polyester polyol resin, 30~40% of blocked polyurethane resin, 15~20% of inorganic filler, 1~5% of titanium dioxide, 1~3% of rare earth element, 3~5% of halloysite nanotube, 1~3% of silicon carbide, 1~2% of graphene, 1~2% of dispersing agent, 1~2% of curing agent, first mix the polyester polyol resin and the blocked polyurethane resin in proportion, heat to 160℃ after uniform mixing, so that the mixture is in a molten state, stir at a speed of 300r / min, the stirring time is 2h, to obtain mixture A;

[0009] S2: mix the inorganic filler, titanium dioxide, rare earth element, halloysite nanotube, silicon carbide and graphene in proportion, grind in a ball mill under a nitrogen atmosphere at a speed of 400r / min, the grinding time is 4h, to obtain mixture B;

[0010] S3: add mixture B to mixture A under a nitrogen atmosphere, continue to stir at 160℃, add the dispersing agent, after stirring for 2h, cool to 100℃, then add the curing agent and continue to stir for 2h, slowly cool to room temperature at a rate of 2℃ / min after the stirring is completed, stand for 24h, to obtain the modified polyurethane paint.

[0011] Further, the polyester polyol resin in S1 is one of ethylene glycol dicarbonate, propylene glycol dicarbonate and hexanediol dicarbonate.

[0012] Further, the inorganic filler in S1 is one of bentonite, talcum powder, glass fiber, barium sulfate and calcium carbonate.

[0013] Further, the rare earth element in S1 is one or more of La, Ce and Pr.

[0014] Further, the dispersing agent in S1 is one of sodium acrylate, water-based acrylic resin and polyoxyethylene stearyl alcohol ether.

[0015] Further, the curing agent in S1 is one of diisocyanate and triisocyanate.

[0016] A preparation method of a direct solderable polyurethane enameled copper flat wire, the preparation method of the direct solderable polyurethane enameled copper flat wire is as follows,

[0017] S71: put the copper round wire into the wire drawing machine, the temperature of the wire drawing oil in the wire drawing machine is <40℃;

[0018] S72: transfer the copper round wire drawn into the annealing furnace, anneal at a speed of 150 m / min under a nitrogen atmosphere;

[0019] S73: The modified polyurethane paint is coated on the surface of the copper round wire with a pull line, and the drying treatment is performed by laser irradiation, and after drying, it is placed for 12h;

[0020] S74: The thermosetting polyamide resin is further coated on the surface of the product prepared in S73, dried at 60℃ for 12h, and after standing for 24h, the product of straight soldering polyurethane enameled copper flat wire is obtained.

[0021] Further, the laser power of the laser irradiation in S73 is 200W, the temperature is 70℃, and the irradiation time is 30min.

[0022] In the present application, the addition of lanthanide rare earth elements in the polyurethane paint refines the crystal grains of the polyurethane paint, thereby increasing the number of grain boundaries and improving the mechanical strength of the polyurethane paint. This is because the rare earth elements can act as heterogeneous cores during the solidification process, increasing the number of crystallization cores and hindering the growth of crystal grains. The lanthanide rare earth elements also increase the bonding strength between the polyurethane paint and the copper round wire, making the polyurethane paint more firmly attached to the copper round wire. This improves the mechanical properties and service life of the product. In addition, the lanthanide rare earth elements can increase the hardness and wear resistance of the polyurethane paint, making it more resistant to external mechanical pressure and friction. This helps to improve the durability and use effect of the product.

[0023] In the present application, the addition of halloysite nanotubes in the polyurethane paint improves the performance of the polyurethane paint. Halloysite nanotubes have a large specific surface area and can form a network structure in the polymer matrix, thereby enhancing the mechanical properties of the polyurethane paint such as hardness, wear resistance and tensile strength. Halloysite nanotubes can also reduce the penetration of water and other small molecular substances in the polyurethane paint, which helps to improve the barrier properties of the polyurethane paint and prolong the service life. The addition of halloysite nanotubes can also improve the rheological properties of the polyurethane paint, making it easier to coat and level during construction.

[0024] In the present application, the addition of silicon carbide and graphene further improves the performance of the polyurethane paint. Silicon carbide and graphene both have extremely high hardness and strength, and their addition can significantly improve the hardness and wear resistance of the polyurethane paint. Silicon carbide and graphene have excellent thermal stability and can maintain structural stability at high temperatures. Their addition can increase the thermal decomposition temperature of the polyurethane paint, allowing it to maintain good performance in high temperature environments. The addition of silicon carbide and graphene can enhance the barrier properties of the polyurethane paint, reducing the penetration of external substances such as water and oxygen, which helps to improve the oxidation resistance of the polyurethane paint and slow down the aging of the enameled copper flat wire.

[0025] The beneficial effects of the present application are:

[0026] The rare earth element can refine the crystal grains of the polyurethane paint, so that the polyurethane paint can be better coated on the copper flat wire; the addition of the halloysite nanotube can make the polymer form a network structure, so that the polyurethane paint has better mechanical strength; the addition of the silicon carbide and the graphene further improves the mechanical strength of the polyurethane paint, and also enhances the barrier property of the polyurethane paint, reduces the penetration of external substances such as moisture and oxygen into the polyurethane paint, which helps to improve the oxidation resistance of the polyurethane paint. DETAILED DESCRIPTION

[0027] In order to further illustrate the technical means and effects adopted by the present application to achieve the predetermined object, the specific embodiments, structures, features and effects according to the present application are described in detail as follows in combination with examples.

[0028] Proportioning ratio 1: ethylene glycol dicarbonate 30%, blocked polyurethane resin 30%, bentonite 20%, titanium dioxide 5%, rare earth element Ce 3%, halloysite nanotube 5%, silicon carbide 3%, graphene 2%, water-based acrylic resin 1%, diisocyanate 1%;

[0029] Proportioning ratio 2: ethylene glycol dicarbonate 20%, blocked polyurethane resin 40%, bentonite 20%, titanium dioxide 5%, rare earth element Ce 3%, halloysite nanotube 5%, silicon carbide 3%, graphene 2%, water-based acrylic resin 1%, diisocyanate 1%;

[0030] Proportioning ratio 3: ethylene glycol dicarbonate 25%, blocked polyurethane resin 40%, bentonite 15%, titanium dioxide 5%, rare earth element Ce 3%, halloysite nanotube 3%, silicon carbide 3%, graphene 2%, water-based acrylic resin 2%, diisocyanate 2%;

[0031] Proportioning ratio 4: ethylene glycol dicarbonate 25%, blocked polyurethane resin 40%, bentonite 15%, titanium dioxide 5%, rare earth element Ce 3%, halloysite nanotube 3%, silicon carbide 3%, graphene 2%, water-based acrylic resin 2%, diisocyanate 2%;

[0032] The preparation method of the intermediate layer modified polyurethane paint is as follows,

[0033] S1: first, mix ethylene glycol dicarbonate and blocked polyurethane resin according to the proportion, mix uniformly, heat to 160 DEG C, make the mixture in a molten state, stir at a speed of 300 r / min, the stirring time is 2h, get the mixture A;

[0034] S2: proportionally mix bentonite, titanium dioxide, rare earth element Ce, halloysite nanotube, silicon carbide, graphene, and grind in a ball mill under a nitrogen atmosphere at a rotating speed of 400 r / min for 4 h to obtain a mixture B;

[0035] S3: add the mixture B to the mixture A under a nitrogen atmosphere, continue to stir at 160℃, add an aqueous acrylic resin, and stir for 2 h, then cool to 100℃, add diisocyanate and continue to stir for 2 h, slowly cool to room temperature at 2℃ / min after completion of stirring, and stand for 24 h to obtain the modified polyurethane paint.

[0036] Example 1

[0037] S71: put the copper round wire into a wire drawing machine to draw the wire, and the temperature of the wire drawing oil in the wire drawing machine is <40℃;

[0038] S72: transfer the drawn copper round wire into an annealing furnace, and anneal at a speed of 150 m / min under a nitrogen atmosphere;

[0039] S73: coat the modified polyurethane paint prepared according to the proportioning ratio 1 on the surface of the drawn copper round wire, and perform drying treatment by laser irradiation, the laser power is 200 W, the temperature is 70℃, the irradiation time is 30 min, and the product is stood for 12 h after drying;

[0040] S74: further coat a thermosetting polyamide resin paint on the surface of the product prepared in S73, dry at 60℃ for 12 h, and obtain the product straight soldering polyurethane enameled copper flat wire after standing for 24 h.

[0041] Example 2

[0042] S71: put the copper round wire into a wire drawing machine to draw the wire, and the temperature of the wire drawing oil in the wire drawing machine is <40℃;

[0043] S72: transfer the drawn copper round wire into an annealing furnace, and anneal at a speed of 150 m / min under a nitrogen atmosphere;

[0044] S73: coat the modified polyurethane paint prepared according to the proportioning ratio 2 on the surface of the drawn copper round wire, and perform drying treatment by laser irradiation, the laser power is 200 W, the temperature is 70℃, the irradiation time is 30 min, and the product is stood for 12 h after drying;

[0045] S74: further coat a thermosetting polyamide resin paint on the surface of the product prepared in S73, dry at 60℃ for 12 h, and obtain the product straight soldering polyurethane enameled copper flat wire after standing for 24 h.

[0046] Example 3

[0047] S71: Put the copper round wire into the wire drawing machine for wire drawing, the temperature of the wire drawing oil in the wire drawing machine is <40℃;

[0048] S72: Transfer the copper round wire after wire drawing into the annealing furnace, and anneal at a speed of 150 m / min under nitrogen atmosphere;

[0049] S73: Apply the modified polyurethane paint prepared according to the proportioning ratio 3 to the surface of the copper round wire after wire drawing, and perform drying treatment by laser irradiation, the laser power is 200W, the temperature is 70℃, the irradiation time is 30min, and after drying, the product is placed for 12h;

[0050] S74: Further apply the thermosetting polyamide resin to the surface of the product prepared in S73, dry at 60℃ for 12h, and after standing for 24h, the product of the straight soldering polyurethane enameled copper flat wire is obtained.

[0051] Example 4

[0052] S71: Put the copper round wire into the wire drawing machine for wire drawing, the temperature of the wire drawing oil in the wire drawing machine is <40℃;

[0053] S72: Transfer the copper round wire after wire drawing into the annealing furnace, and anneal at a speed of 150 m / min under nitrogen atmosphere;

[0054] S73: Apply the modified polyurethane paint prepared according to the proportioning ratio 4 to the surface of the copper round wire after wire drawing, and perform drying treatment by laser irradiation, the laser power is 200W, the temperature is 70℃, the irradiation time is 30min, and after drying, the product is placed for 12h;

[0055] S74: Further apply the thermosetting polyamide resin to the surface of the product prepared in S73, dry at 60℃ for 12h, and after standing for 24h, the product of the straight soldering polyurethane enameled copper flat wire is obtained.

[0056] Comparative Example 1

[0057] S71: Put the copper round wire into the wire drawing machine for wire drawing, the temperature of the wire drawing oil in the wire drawing machine is <40℃;

[0058] S72: Transfer the copper round wire after wire drawing into the annealing furnace, and anneal at a speed of 150 m / min under nitrogen atmosphere;

[0059] S73: Apply the unmodified polyurethane paint to the surface of the copper round wire after wire drawing, and perform drying treatment by laser irradiation, the laser power is 200W, the temperature is 70℃, the irradiation time is 30min, and after drying, the product is placed for 12h;

[0060] S74: again coating the thermosetting polyamide resin paint to the surface of the product prepared in S73, drying at 60 DEG C for 12h, and after standing for 24h, obtaining the product straight soldering polyurethane paint covered copper flat wire.

[0061] The comparative example uses unmodified polyurethane paint without adding rare earth element Ce, halloysite nanotube, silicon carbide and graphene, and other proportions are the same as those in proportion 2.

[0062] The straight soldering polyurethane paint covered copper flat wire prepared is subjected to mechanical strength test according to the ISO 527 tensile test method, and the specific test method is as follows,

[0063] 1. mounting the test sample on the tensile testing machine, ensuring that the mounting direction of the sample is consistent with the tensile direction;

[0064] 2. setting the tensile speed to 2mm / s, the tensile force to 200N, and the tensile time to 20s;

[0065] 3. recording the tensile condition and analyzing the tensile strength of the sample.

[0066] The experimental results of the examples and the comparative examples are as follows,

[0067] Modified polyurethane paint formula proportion Tensile strength (MPa) Example 1 Proportion 1 13 Example 2 Proportion 2 17 Example 3 Proportion 3 16 Example 4 Proportion 4 15 Comparative example 1 Proportion 2 101

[0068] From the experimental results, it can be seen that the modification of the polyurethane paint effectively improves the mechanical strength of the prepared product straight soldering polyurethane paint covered copper flat wire, and example 2 is the best example.

[0069] When the present application is used:

[0070] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above with a preferred embodiment, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content without departing from the scope of the present application, and any equivalent embodiments with equivalent changes are equivalent to the above embodiments. Any modification, change and modification of the above embodiments according to the technical essence of the present application are still within the scope of the present application.

Claims

1. A straight-solderable polyurethane enamelled copper flat wire, characterized by, The straight-soldering polyurethane enameled copper flat wire comprises an internal copper round wire, an intermediate layer of modified polyurethane enamel and an outer layer of thermosetting polyamide resin enamel, wherein the preparation method of the intermediate layer of modified polyurethane enamel comprises the following steps, S1: in terms of weight percentage, 20-30% of polyester polyol resin, 30-40% of blocked polyurethane resin, 15-20% of inorganic filler, 1-5% of titanium dioxide, 1-3% of rare earth element, 3-5% of halloysite nanotube, 1-3% of silicon carbide, 1-2% of graphene, 1-2% of dispersing agent and 1-2% of curing agent are mixed, the mixture is heated to 160 DEG C after uniform mixing, the mixture is stirred at a speed of 300 r / min for 2 h to obtain mixture A; S2: the inorganic filler, titanium dioxide, rare earth element, halloysite nanotube, silicon carbide and graphene are mixed in proportion, and are ground in a ball mill under a nitrogen atmosphere at a speed of 400 r / min for 4 h to obtain mixture B; S3: mixture B is added to mixture A under a nitrogen atmosphere, and stirring is continued at 160 DEG C, the dispersing agent is added, and stirring is continued for 2 h, then the temperature is lowered to 100 DEG C, the curing agent is added and stirring is continued for 2 h, the temperature is slowly lowered to room temperature at a rate of 2 DEG C / min, and the product is left to stand for 24 h to obtain the modified polyurethane enamel.

2. A straight solderable polyurethane enamelled copper flat wire according to claim 1, characterized in that, The polyester polyol resin in S1 is one of ethylene glycol dicarbonate, propylene glycol dicarbonate and hexanediol dicarbonate.

3. A straight solderable polyurethane enamelled copper flat wire according to claim 1, characterized in that, The inorganic filler in S1 is one of bentonite, talcum powder, glass fiber, barium sulfate and calcium carbonate.

4. The straight-solderable polyurethane enamelled copper flat wire according to claim 1, characterized in that, The rare earth element in S1 is one or more of La, Ce and Pr.

5. A straight solderable polyurethane enamelled copper flat wire according to claim 1, characterized in that, The dispersing agent in S1 is one of sodium acrylate, water-based acrylic resin and polyoxyethylene stearyl alcohol ether.

6. A straight solderable polyurethane enamelled copper flat wire according to claim 1, characterized in that, The curing agent in S1 is one of diisocyanate and triisocyanate.

7. A method for preparing a direct soldering polyurethane enameled copper flat wire, based on the direct soldering polyurethane enameled copper flat wire according to any one of claims 1 to 6, characterized in that, The preparation method of the straight-soldering polyurethane enameled copper flat wire comprises the following steps, S71: the copper round wire is placed in a wire drawing machine, and the temperature of the oil in the wire drawing machine is less than 40 DEG C; S72: the copper round wire after wire drawing is transferred into an annealing furnace, and is annealed at a speed of 150 m / min under a nitrogen atmosphere; S73: the modified polyurethane enamel is coated on the surface of the copper round wire after wire drawing, and is dried by laser irradiation, and is left to stand for 12 h after drying; S74: the thermosetting polyamide resin enamel is further coated on the surface of the product prepared in S73, and is dried at 60 DEG C for 12 h, and is left to stand for 24 h to obtain the straight-soldering polyurethane enameled copper flat wire.

8. The method of claim 7, wherein the method further comprises the step of: The laser power of the laser irradiation in S73 is 200 W, the temperature is 70 DEG C, and the irradiation time is 30 min. ​