A tin-plated copper wire and its manufacturing process

Abstract

This invention discloses a tin-plated copper wire and its manufacturing process, relating to the field of wire and cable technology. In preparing the tin-plated copper wire, the invention first involves a transesterification reaction of 2-amino-1,3-propanediol and tetraethyl orthosilicate to obtain a protective solution. The copper wire is then drawn using a traction machine and sequentially subjected to pickling, washing, drying, protective solution treatment, preheating and low-temperature tinning, high-temperature tinning, cooling, pickling, washing, drying, and winding to obtain the tin-plated copper wire. The tin-plated copper wire prepared by this invention has high quality, high tensile strength, and is easy to industrialize.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric wire and cable, in particular to a tinned copper wire and a production process thereof. BACKGROUND

[0002] The tinned copper wire refers to a copper wire plated with a thin layer of tin on the surface. The tinned copper wire is relatively soft in material and has good electrical conductivity. Compared with bare copper wire, the tinned copper wire has stronger corrosion resistance and oxidation resistance, and can greatly prolong the service life of weak electric cable. The tinned copper wire is widely used in the conductive core of some rubber-insulated electric wire and cable and the conductive core of instrument installation wire. The former is to prevent the rubber from sticking and the copper wire core from becoming black and brittle after the rubber directly contacts the copper wire. The latter is to improve the weldability of the conductive core.

[0003] At present, the production of tinned copper wire in the cable industry in China still mostly adopts hot tinning process. However, the tin layer is not easy to control in the hot tinning process, and the continuity and adhesion are poor. The uneven thickness causes the surface of the wire body to be not smooth, and the like. Therefore, the production process of the tinned copper wire is improved. SUMMARY

[0004] The present application aims to provide a tinned copper wire and a production process thereof to solve the problems in the prior art.

[0005] As an optimization, the production process of the tinned copper wire mainly includes the following process steps:

[0006] (1) Pickling: The copper wire is pulled by a pulling machine to enter the pickling solution. The pickling solution is a hydrochloric acid solution with a pH of 1.9-2.1. The time for the same point on the copper wire to enter the liquid surface to the liquid surface out of the pickling solution is 8-12 s. The temperature of the pickling solution is 20-30℃;

[0007] (2) Water washing: After the pickling solution, the copper wire enters the pure water. The temperature of the pure water is 40-50℃. The time for the same point on the copper wire to enter the liquid surface of the pure water to the liquid surface out of the pure water is 8-12 s;

[0008] (3) Drying: After the pure water, the copper wire enters the drying section at 80-90℃. The time for the same point on the copper wire to pass through the drying section is 14-16 s;

[0009] (4) Protective liquid treatment: After the copper wire passes through the drying section, the copper wire enters the protective liquid. The temperature of the protective liquid is 110-120℃. The time for the same point on the copper wire to enter the liquid surface of the protective liquid to the liquid surface out of the protective liquid is 8-12 s. When the liquid surface out of the protective liquid, the redundant protective liquid is blown off by nitrogen gas with a temperature of 110-120℃ and a flow rate of 30-40 cm / s. The blowing direction of the nitrogen gas is opposite to the pulling direction of the copper wire. The length of the blowing nitrogen gas is 20-30 cm;

[0010] (5) preheating and low-temperature tin: continue to pull the copper wire into the preheating section, the preheating temperature is 160~180℃, the same point on the copper wire passes through the preheating section for 14~16s, and then enters the low-temperature tin water with a temperature of 240~250℃, the same point on the copper wire takes 6~8s from entering the liquid surface of the low-temperature tin water to leaving the liquid surface of the low-temperature tin water, and the temperature of the liquid surface of the low-temperature tin water is 240~250℃, the flow rate of nitrogen gas used to blow off the excess low-temperature tin water is 30~40cm / s, the direction of the nitrogen gas blowing is opposite to the direction of pulling the copper wire, and the length of the nitrogen gas blowing is 20~30cm;

[0011] (6) temperature rising and high-temperature tin: continue to pull the copper wire to rise the temperature, after the temperature rising, enter the high-temperature tin water with a temperature of 750~800℃, the same point on the copper wire takes 20~30s from entering the liquid surface of the high-temperature tin water to leaving the liquid surface of the high-temperature tin water, and the temperature of the liquid surface of the high-temperature tin water is 750~800℃, the flow rate of nitrogen gas used to blow off the excess high-temperature tin water is 30~40cm / s, the direction of the nitrogen gas blowing is opposite to the direction of pulling the copper wire, and the length of the nitrogen gas blowing is 20~30cm;

[0012] (7) temperature falling and winding: continue to pull the copper wire to fall the temperature, after the temperature falling, repeat steps (1), (2) and (3) once in turn, and finally wind, to obtain the tinned copper wire.

[0013] As an optimization, the copper wire in step (1) has a diameter of 0.4~2mm and a purity of greater than 99.9%.

[0014] As an optimization, the preparation method of the protective liquid in step (4) is as follows: uniformly mix 2-amino-1,3-propanediol and tetraethyl orthosilicate according to a molar ratio of 1.4:1~1.8:1, then add p-toluenesulfonic acid with a mass of 0.01~0.02 times that of the tetraethyl orthosilicate, stir at 80~90℃ and 300~500r / min for 20~30min, continue to stir at 130~140℃ for 6~8h, cool to room temperature, and then stand at 50~60℃ and 1~2kPa for 30~40min.

[0015] As an optimization, the temperature rising method in step (6) is as follows: pull the copper wire into the temperature rising section, the temperature rising section is divided into four temperature rising chambers arranged from low to high temperature, and the temperatures of the four temperature rising chambers are 280~300℃, 380~400℃, 480~500℃ and 580~600℃ in turn, and the same point on the copper wire takes 20~30s to pass through each temperature rising chamber.

[0016] As optimization, the method for cooling in step (7) is: the copper wire is pulled into a cooling section, the cooling section is divided into four cooling chambers arranged from high to low temperature, and the four cooling chambers are 580-600 DEG C, 440-460 DEG C, 280-300 DEG C and 140-160 DEG C in sequence, and the time for the same point on the copper wire to pass through each cooling chamber is 30-40 s.

[0017] Compared with the prior art, the present application has the following beneficial effects:

[0018] In the preparation of the tinned copper wire, the copper wire is pulled by a pulling machine, and the copper wire sequentially passes through acid washing, water washing, drying, protective liquid treatment, preheating and low-temperature tinning, temperature rising and high-temperature tinning, cooling, acid washing, water washing, drying and winding to prepare the tinned copper wire.

[0019] Firstly, the ester exchange reaction is carried out between 2-amino-1,3-propanediol and tetraethyl orthosilicate to obtain the protective liquid, the amino group on the protective liquid is protected by metal coordination adsorption on the copper wire, and the amino group is protected in the subsequent high-temperature tinning, the protective liquid is cracked into siloxane free radicals and organic small molecules, the organic small molecules overflow, the surface is uneven, the interface tooth effect is formed in the subsequent high-temperature tinning, the interface bonding effect is improved, the siloxane free radicals and the copper wire and tin are connected through the siloxane bond, and the interface bonding effect is further improved, so that the quality and tensile strength are improved.

[0020] Secondly, the preheating and low-temperature tinning and the temperature rising and high-temperature tinning are carried out, the product has better quality through two times of tinning, the whole process is easy to implement through simple mechanical equipment, the performance of the obtained product is stable, and the product is easy to popularize and industrialize. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the present application. EMBODIMENT

[0022] A production process of tinned copper wire mainly includes the following process steps:

[0023] (1) acid washing: the copper wire with a diameter of 0.5 mm is pulled by a pulling machine, the copper wire enters the acid washing liquid, the acid washing liquid is a hydrochloric acid solution with a pH of 1.9, the time for the same point on the copper wire to pass from the liquid surface to the liquid surface is 12 s, and the temperature of the acid washing liquid is 20 DEG C.

[0024] (2) water washing: after the acid washing solution, into the pure water, the pure water temperature is 40℃, the same point on the copper wire from the liquid surface into the pure water to the liquid surface out of the pure water is 12s;

[0025] (3) drying: after the pure water, into the drying section, at 80℃, the same point on the copper wire through the drying section time is 16s;

[0026] (4) protective liquid treatment: 2-amino-1, 3-propanediol, tetraethyl orthosilicate is mixed uniformly according to the molar ratio of 1.4:1, then 0.01 times the mass of tetraethyl orthosilicate is added to p-toluene sulfonic acid, stirred at 80℃, 300r / min for 30min, then heated to 130℃ and continue to stir for 8h, cooled to room temperature, then placed at 50℃, 1kPa for 40min to prepare the protective liquid; the copper wire enters the protective liquid after the drying section, the protective liquid temperature is 110℃, the same point on the copper wire from the liquid surface into the protective liquid to the liquid surface out of the protective liquid is 12s, when the liquid surface out of the protective liquid, the redundant protective liquid is blown off by nitrogen gas with the temperature of 110℃ and the flow rate of 30cm / s, the direction of the nitrogen gas blowing is opposite to the direction of the copper wire pulling, and the length of the nitrogen gas blowing is 30cm;

[0027] (5) preheating and low temperature tin plating: continue to pull the copper wire into the preheating section, the preheating temperature is 160℃, the same point on the copper wire through the preheating section time is 14s, then into the low temperature tin water with the temperature of 240℃, the same point on the copper wire from the liquid surface into the low temperature tin water to the liquid surface out of the low temperature tin water is 8s, when the liquid surface out of the low temperature tin water, the redundant low temperature tin water is blown off by nitrogen gas with the temperature of 240℃ and the flow rate of 30cm / s, the direction of the nitrogen gas blowing is opposite to the direction of the copper wire pulling, and the length of the nitrogen gas blowing is 30cm;

[0028] (6) temperature rising and high temperature tin plating: continue to pull the copper wire into the temperature rising section, the temperature rising section is divided into four temperature rising chambers, arranged according to the temperature from low to high, in turn, 280℃, 380℃, 480℃, 580℃, the same point on the copper wire through each temperature rising chamber is 30s, after the temperature rising, into the high temperature tin water with the temperature of 750℃, the same point on the copper wire from the liquid surface into the high temperature tin water to the liquid surface out of the high temperature tin water is 30s, when the liquid surface out of the high temperature tin water, the redundant high temperature tin water is blown off by nitrogen gas with the temperature of 750℃ and the flow rate of 30cm / s, the direction of the nitrogen gas blowing is opposite to the direction of the copper wire pulling, and the length of the nitrogen gas blowing is 30cm;

[0029] (7) temperature falling and winding: continue to pull the copper wire into the temperature falling section, the temperature falling section is divided into four temperature falling chambers, arranged according to the temperature from high to low, in turn, 580℃, 440℃, 280℃, 140℃, the same point on the copper wire through each temperature falling chamber is 30s, after the temperature falling, repeat steps (1), (2), (3) once in turn, finally winding, to obtain the tinned copper wire. Embodiment

[0030] A production process of tinned copper wire, which mainly comprises the following process steps:

[0031] (1) pickling: the copper wire with a diameter of 0.5 mm is pulled by a pulling machine to make the copper wire enter the pickling solution, the pickling solution is a hydrochloric acid solution with a pH of 2, the time for the same point on the copper wire to enter the liquid surface to the liquid surface out of the pickling solution is 10 s, and the temperature of the pickling solution is 22℃.

[0032] (2) water washing: after the pickling solution, enter the pure water, the temperature of the pure water is 42℃, the time for the same point on the copper wire to enter the liquid surface of the pure water to the liquid surface out of the pure water is 10 s;

[0033] (3) drying: after the pure water, enter the drying section, at 82℃, the time for the same point on the copper wire to pass through the drying section is 12 s;

[0034] (4) protective liquid treatment: 2-amino-1, 3-propanediol and tetraethyl orthosilicate are mixed uniformly according to a molar ratio of 1.6:1, then p-toluenesulfonic acid with a mass of 0.015 times of the tetraethyl orthosilicate is added, stirred at 85℃ and 400 r / min for 25 min, then heated to 135℃ and continue to stir for 7 h, cooled to room temperature, then placed at 55℃ and 1.5 kPa for 35 min to prepare the protective liquid; the copper wire enters the protective liquid after passing through the drying section, the temperature of the protective liquid is 115℃, the time for the same point on the copper wire to enter the liquid surface of the protective liquid to the liquid surface out of the protective liquid is 10 s, when the liquid surface out of the protective liquid, the redundant protective liquid is blown off by nitrogen gas with a temperature of 115℃ and a flow rate of 35 cm / s, the direction of the nitrogen gas blowing is opposite to the pulling direction of the copper wire, and the length of the nitrogen gas blowing is 25 cm;

[0035] (5) preheating and low-temperature tinning: continue to pull the copper wire to enter the preheating section, the preheating temperature is 170℃, the time for the same point on the copper wire to pass through the preheating section is 15 s, then enter the low-temperature tin water with a temperature of 245℃, the time for the same point on the copper wire to enter the liquid surface of the low-temperature tin water to the liquid surface out of the low-temperature tin water is 7 s, when the liquid surface out of the low-temperature tin water, the redundant low-temperature tin water is blown off by nitrogen gas with a temperature of 240~250℃ and a flow rate of 35 cm / s, the direction of the nitrogen gas blowing is opposite to the pulling direction of the copper wire, and the length of the nitrogen gas blowing is 25 cm;

[0036] (6) heating and high-temperature tin plating: continue to pull the copper wire into the heating section, which is divided into four heating chambers arranged from low to high temperature, namely 290℃, 390℃, 490℃ and 590℃. The same point on the copper wire takes 25s to pass through each heating chamber. After heating, the copper wire enters high-temperature tin water with a temperature of 780℃. The same point on the copper wire takes 25s to pass through the liquid surface of the high-temperature tin water. When the copper wire exits the liquid surface of the high-temperature tin water, nitrogen gas with a temperature of 780℃ and a flow rate of 35cm / s is used to blow off the excess high-temperature tin water. The direction of the nitrogen gas blowing is opposite to the pulling direction of the copper wire. The length of the nitrogen gas blowing is 25cm;

[0037] (7) cooling and winding: continue to pull the copper wire into the cooling section, which is divided into four cooling chambers arranged from high to low temperature, namely 590℃, 450℃, 290℃ and 150℃. The same point on the copper wire takes 35s to pass through each cooling chamber. After exiting the cooling section, repeat steps (1), (2) and (3) once, and finally wind the copper wire, thereby obtaining the tinned copper wire. Embodiment

[0038] A production process of tinned copper wire mainly includes the following process steps:

[0039] (1) acid pickling: pull the copper wire with a diameter of 0.5mm through the pulling machine to make the copper wire enter the acid pickling solution, which is a hydrochloric acid solution with a pH of 2.1. The same point on the copper wire takes 8s to pass through the liquid surface of the acid pickling solution. The temperature of the acid pickling solution is 30℃.

[0040] (2) water washing: after exiting the acid pickling solution, enter the pure water. The temperature of the pure water is 50℃. The same point on the copper wire takes 8s to pass through the liquid surface of the pure water.

[0041] (3) drying: after exiting the pure water, enter the drying section. The temperature of the drying section is 90℃. The same point on the copper wire takes 14s to pass through the drying section.

[0042] (4) protective liquid treatment: mix 2-amino-1,3-propanediol and tetraethyl orthosilicate uniformly according to a molar ratio of 1.8:1, then add p-toluenesulfonic acid with a mass of 0.02 times that of the tetraethyl orthosilicate, stir and react at 90℃ and 500r / min for 20min, then continue to stir and react at 140℃ for 6h, cool to room temperature, then stand at 60℃ and 2kPa for 30min, thereby obtaining the protective liquid. After the copper wire passes through the drying section, enter the protective liquid. The temperature of the protective liquid is 120℃. The same point on the copper wire takes 8s to pass through the liquid surface of the protective liquid. When the copper wire exits the liquid surface of the protective liquid, nitrogen gas with a temperature of 120℃ and a flow rate of 40cm / s is used to blow off the excess protective liquid. The direction of the nitrogen gas blowing is opposite to the pulling direction of the copper wire. The length of the nitrogen gas blowing is 20cm.

[0043] (5) Preheating and low-temperature tin passing: continue to pull the copper wire into the preheating section, the preheating temperature is 180℃, the same point on the copper wire takes 14s to pass through the preheating section, and then enters the low-temperature tin water with a temperature of 250℃, the same point on the copper wire takes 6s to pass from the liquid surface of the low-temperature tin water to the liquid surface of the low-temperature tin water, and the temperature of the liquid surface of the low-temperature tin water is 240-250℃, the flow rate of nitrogen gas used to blow off the excess low-temperature tin water is 40cm / s, the blowing direction of the nitrogen gas is opposite to the pulling direction of the copper wire, and the length of the nitrogen gas blowing is 20cm;

[0044] (6) Temperature rising and high-temperature tin passing: continue to pull the copper wire into the temperature rising section, the temperature rising section is divided into four temperature rising chambers, which are arranged in the order of 300℃, 400℃, 500℃ and 600℃ from low to high, the same point on the copper wire takes 20s to pass through each temperature rising chamber, and then enters the high-temperature tin water with a temperature of 800℃, the same point on the copper wire takes 20s to pass from the liquid surface of the high-temperature tin water to the liquid surface of the high-temperature tin water, and the temperature of the liquid surface of the high-temperature tin water is 800℃, the flow rate of nitrogen gas used to blow off the excess high-temperature tin water is 40cm / s, the blowing direction of the nitrogen gas is opposite to the pulling direction of the copper wire, and the length of the nitrogen gas blowing is 20cm;

[0045] (7) Temperature falling and winding: continue to pull the copper wire into the temperature falling section, the temperature falling section is divided into four temperature falling chambers, which are arranged in the order of 600℃, 460℃, 300℃ and 160℃ from high to low, the same point on the copper wire takes 30s to pass through each temperature falling chamber, and then repeats steps (1), (2) and (3) once after leaving the temperature falling section, and finally winds up to obtain the tinned copper wire.

[0046] Comparative Example 1

[0047] The preparation method of the magnesium-potassium inorganic material composite fertilizer prepared from the waste resources of Comparative Example 1 is different from that of Example 2 only in that step (4) is not performed, and step (5) is directly performed after step (3) of drying.

[0048] Comparative Example 2

[0049] A production process of tinned copper wire mainly includes the following process steps:

[0050] (1) Acid pickling: a copper wire with a diameter of 0.5mm is pulled by a pulling machine to make the copper wire enter an acid pickling solution, the acid pickling solution is a hydrochloric acid solution with a pH of 2, the same point on the copper wire takes 10s to pass from the liquid surface to the liquid surface, and the temperature of the acid pickling solution is 22℃.

[0051] (2) Water washing: after leaving the acid pickling solution, the copper wire enters pure water, the temperature of the pure water is 42℃, and the same point on the copper wire takes 10s to pass from the liquid surface of the pure water to the liquid surface of the pure water;

[0052] (3) Drying: After the pure water is discharged, the copper wire is led into the drying section, and the time for the same point on the copper wire to pass through the drying section at 82℃ is 12s;

[0053] (4) Protective liquid treatment: 2-amino-1, 3-propanediol and tetraethyl orthosilicate are uniformly mixed at a molar ratio of 1.6:1, then para-toluene sulfonic acid with a mass of 0.015 times that of the tetraethyl orthosilicate is added, and the mixture is stirred at 400r / min at 85℃ for 25min, then the temperature is increased to 135℃ and the stirring is continued for 7h, and after the mixture is cooled to room temperature, it is placed at 55℃ and 1.5kPa for 35min to prepare the protective liquid; the copper wire is led into the protective liquid after passing through the drying section, the temperature of the protective liquid is 115℃, and the time for the same point on the copper wire to pass from the liquid surface entering the protective liquid to the liquid surface leaving the protective liquid is 10s; the redundant protective liquid is blown off by nitrogen gas with a temperature of 115℃ and a flow rate of 35cm / s at the liquid surface leaving the protective liquid, the blowing direction of the nitrogen gas is opposite to the pulling direction of the copper wire, and the length of the blowing nitrogen gas is 25cm;

[0054] (5) Heating and high-temperature passing through tin: the copper wire is continuously led into the preheating section, the preheating temperature is 170℃, and the time for the same point on the copper wire to pass through the preheating section is 15s; the copper wire is continuously led into the heating section, the heating section is divided into four heating chambers arranged from low to high in temperature, and the temperatures of the four heating chambers are 290℃, 390℃, 490℃ and 590℃ in sequence; the time for the same point on the copper wire to pass through each heating chamber is 25s; after the heating is completed, the copper wire is led into the high-temperature tin water with a temperature of 780℃, and the time for the same point on the copper wire to pass from the liquid surface entering the high-temperature tin water to the liquid surface leaving the high-temperature tin water is 25s; the redundant high-temperature tin water is blown off by nitrogen gas with a temperature of 780℃ and a flow rate of 35cm / s at the liquid surface leaving the high-temperature tin water, the blowing direction of the nitrogen gas is opposite to the pulling direction of the copper wire, and the length of the blowing nitrogen gas is 25cm;

[0055] (6) Cooling and winding: the copper wire is continuously led into the cooling section, the cooling section is divided into four cooling chambers arranged from high to low in temperature, and the temperatures of the four cooling chambers are 590℃, 450℃, 290℃ and 150℃ in sequence; the time for the same point on the copper wire to pass through each cooling chamber is 35s; after the copper wire leaves the cooling section, steps (1), (2) and (3) are repeated once in sequence, and finally the copper wire is wound to obtain the tinned copper wire.

[0056] Comparative Example 3

[0057] A production process of a tinned copper wire mainly includes the following process steps:

[0058] (1) Acid pickling: a copper wire with a diameter of 0.5mm is pulled by a pulling machine so that the copper wire enters an acid pickling solution which is a hydrochloric acid solution with a pH of 2; the time for the same point on the copper wire to pass from the liquid surface entering the acid pickling solution to the liquid surface leaving the acid pickling solution is 10s, and the temperature of the acid pickling solution is 22℃.

[0059] (2) water washing: after the acid washing solution, into the pure water, the pure water temperature is 42℃, the same point on the copper wire from the liquid surface into the pure water to the liquid surface out of the pure water is 10s;

[0060] (3) drying: after the pure water, into the drying section, at 82℃, the same point on the copper wire through the drying section is 12s;

[0061] (4) protective liquid treatment: 2-amino-1, 3-propanediol, tetraethyl orthosilicate is mixed uniformly according to the molar ratio of 1.6:1, then p-toluenesulfonic acid is added, the mass of tetraethyl orthosilicate is 0.015 times, stirring at 85℃, 400r / min for 25min, then heating to 135℃ and continuing to stir for 7h, cooling to room temperature, then standing at 55℃, 1.5kPa for 35min, to prepare the protective liquid; the copper wire passes through the drying section and then enters the protective liquid, the temperature of the protective liquid is 115℃, the same point on the copper wire from the liquid surface into the protective liquid to the liquid surface out of the protective liquid is 10s, when the liquid surface out of the protective liquid, the nitrogen gas with a temperature of 115℃ and a flow rate of 35cm / s is used to blow off the excess protective liquid, the direction of the nitrogen gas blowing is opposite to the direction of the copper wire pulling, and the length of the nitrogen gas blowing is 25cm;

[0062] (5) preheating and low temperature tin plating: continue to pull the copper wire into the preheating section, the preheating temperature is 170℃, the same point on the copper wire through the preheating section is 15s, then enter the low temperature tin water with a temperature of 245℃, the same point on the copper wire from the liquid surface into the low temperature tin water to the liquid surface out of the low temperature tin water is 7s, when the liquid surface out of the low temperature tin water, the nitrogen gas with a temperature of 240~250℃ and a flow rate of 35cm / s is used to blow off the excess low temperature tin water, the direction of the nitrogen gas blowing is opposite to the direction of the copper wire pulling, and the length of the nitrogen gas blowing is 25cm;

[0063] (6) cooling and winding: continue to pull the copper wire into the cooling section, the temperature of the cooling section is 150℃, the same point on the copper wire through each cooling section is 35s, after the cooling section, repeat steps (1), (2) and (3) once, and finally wind, to obtain the tinned copper wire.

[0064] Test example

[0065] Quality and tensile property detection

[0066] Detection method: the tinned copper wires prepared in examples 1~3 and comparative examples 1~3 are tested according to GB-T 4910-2009 to test the tensile strength, and the appearance is observed. The results are shown in table 1.

[0067] Table 1

[0068]

[0069] From the comparison of the experimental data of Example 1, 2, 3 and Comparative Example 1 in Table 1, it can be found that the appearance of Example 1, 2, 3 and Comparative Example 1 is good, and the tensile strength is high, which shows that the amino group on the protective liquid can be protected by metal coordination adsorption on the copper wire through pretreatment with the protective liquid. At high temperature, the protective liquid is cracked into siloxane free radicals and small organic molecules, the small organic molecules overflow, making the surface uneven, which forms an interface tooth effect for subsequent high-temperature tinning, improves the interface bonding effect, the siloxane free radicals and copper wire and tin form a connection through siloxane bond, further improve the interface bonding effect, thereby improving the quality and tensile strength. From the comparison of the experimental data of Example 1, 2, 3 and Comparative Example 2, 3 in Table 1, it can be found that the appearance of Example 1, 2, 3 and Comparative Example 2, 3 is good, which shows that two tinning processes can make the product have better quality, and the tensile strength of the product obtained by lacking the heating and high-temperature tinning step is relatively weak.

[0070] It will be apparent to those skilled in the art that the application is not limited to the details of the foregoing exemplary embodiments and that the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. No feature of the application is to be construed as a limitation thereon unless it is expressly stated to be such.

Claims

1. A process for the production of tinned copper wire, characterized in that, The production process of the tin-plated copper wire mainly comprises the following process steps: (1) pickling: the copper wire is pulled by a traction machine to enter the pickling solution, the pickling solution is a hydrochloric acid solution with a pH of 1.9-2.1, the time for the same point on the copper wire from entering the liquid surface to leaving the liquid surface is 8-12 s, and the temperature of the pickling solution is 20-30℃; (2) water washing: after leaving the pickling solution, the copper wire enters pure water, the temperature of the pure water is 40-50℃, and the time for the same point on the copper wire from entering the liquid surface of the pure water to leaving the liquid surface of the pure water is 8-12 s; (3) drying: after leaving the pure water, the copper wire enters the drying section, the temperature of the drying section is 80-90℃, and the time for the same point on the copper wire to pass through the drying section is 14-16 s; (4) protective liquid treatment: after passing through the drying section, the copper wire enters the protective liquid, the temperature of the protective liquid is 110-120℃, the time for the same point on the copper wire from entering the liquid surface of the protective liquid to leaving the liquid surface of the protective liquid is 8-12 s, and when leaving the liquid surface of the protective liquid, the excess protective liquid is blown off by nitrogen gas with a temperature of 110-120℃ and a flow rate of 30-40 cm / s, the blowing direction of the nitrogen gas is opposite to the pulling direction of the copper wire, and the length of the blowing nitrogen gas is 20-30 cm; (5) preheating and low-temperature tin plating: the copper wire is continuously pulled to enter the preheating section, the temperature of the preheating section is 160-180℃, the time for the same point on the copper wire to pass through the preheating section is 14-16 s, and then the copper wire enters the low-temperature tin water with a temperature of 240-250℃, the time for the same point on the copper wire from entering the liquid surface of the low-temperature tin water to leaving the liquid surface of the low-temperature tin water is 6-8 s, and when leaving the liquid surface of the low-temperature tin water, the excess low-temperature tin water is blown off by nitrogen gas with a temperature of 240-250℃ and a flow rate of 30-40 cm / s, the blowing direction of the nitrogen gas is opposite to the pulling direction of the copper wire, and the length of the blowing nitrogen gas is 20-30 cm; (6) temperature rising and high-temperature tin plating: the copper wire is continuously pulled to rise in temperature, after the temperature rising is completed, the copper wire enters the high-temperature tin water with a temperature of 750-800℃, the time for the same point on the copper wire from entering the liquid surface of the high-temperature tin water to leaving the liquid surface of the high-temperature tin water is 20-30 s, and when leaving the liquid surface of the high-temperature tin water, the excess high-temperature tin water is blown off by nitrogen gas with a temperature of 750-800℃ and a flow rate of 30-40 cm / s, the blowing direction of the nitrogen gas is opposite to the pulling direction of the copper wire, and the length of the blowing nitrogen gas is 20-30 cm; (7) temperature falling and winding: the copper wire is continuously pulled to fall in temperature, after the temperature falling, steps (1), (2) and (3) are repeatedly performed once, and finally the copper wire is wound, thereby obtaining the tin-plated copper wire.

2. A process for producing tinned copper wire as claimed in claim 1, wherein, In step (1), the copper wire has a diameter of 0.4-2 mm and a purity of greater than 99.9%.

3. A process for producing tinned copper wire as claimed in claim 1, wherein, In step (4), the protective liquid is prepared by the following method: 2-amino-1,3-propanediol and tetraethyl orthosilicate are uniformly mixed according to a molar ratio of 1.4:1-1.8:1, then para-toluenesulfonic acid with a mass of 0.01-0.02 times that of the tetraethyl orthosilicate is added, stirring is performed at 80-90℃ and 300-500 r / min for 20-30 min, the temperature is then increased to 130-140℃, and stirring is continuously performed for 6-8 h, after cooling to room temperature, the prepared protective liquid is placed at 50-60℃ and 1-2 kPa for 30-40 min.

4. A process for producing tinned copper wire as claimed in claim 1, wherein, The method of the temperature rising in step (6) is that the copper wire is pulled into the temperature rising section, the temperature rising section is divided into four temperature rising chambers, which are arranged from low to high according to the temperature, and are 280-300 DEG C, 380-400 DEG C, 480-500 DEG C and 580-600 DEG C in sequence, and the time of the same point on the copper wire passing through each temperature rising chamber is 20-30 s.

5. A process for producing tinned copper wire as claimed in claim 1, wherein, The method of the temperature falling in step (7) is that the copper wire is pulled into the temperature falling section, the temperature falling section is divided into four temperature falling chambers, which are arranged from high to low according to the temperature, and are 580-600 DEG C, 440-460 DEG C, 280-300 DEG C and 140-160 DEG C in sequence, and the time of the same point on the copper wire passing through each temperature falling chamber is 30-40 s.

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