KR100339713B1 - Production method of bead wire coated with a little amount of coating material - Google Patents

Abstract

The present invention relates to a method for producing a low plating coating amount bead wire used for reinforcing bead portions of automobile tires.

The production method of the low plating adhesion amount bead wire of the present invention is to form a bronze plating layer having a composition of 83 to 93 wt% Cu and 7 to 17 wt% Sn and a plating layer thickness of 0.03 to 0.06 μm on the surface of the wire, and bead wire before bronze plating. Degreasing treatment using a degreasing solution having a temperature of 60 to 80 DEG C and a degreasing agent of NaOH as 1.0 to 3.0 N, and a sulfuric acid active solution having a temperature of 60 to 80 DEG C and a concentration of sulfuric acid of 2.0 to 5.0 After sequentially carrying out the active treatment with the wt% active liquid, the concentration of Cu is 0.5 to 1.5g / l, the concentration of Sn is 0.1 to 1.0g / l, the iron concentration is 4wt%, and the acid concentration is 1.0 to 2.5N. It is technical in bronze plating in a plating solution at 35 to 60 ° C.

The method of the present invention can improve the plating speed by about 15 to 30%, thereby greatly improving the plating productivity, and by using a plating liquid having a low plating metal concentration, the waste plating solution processing cost can be reduced, and the degreasing solution Considering the increase in energy consumption due to the rise of the temperature of the active liquid and the plating liquid, sufficient production cost reduction is expected.

Description

Production method of bead wire coated with a little amount of coating material}

The present invention relates to a method for producing a bronze plated bead wire used for reinforcing bead portions of automobile tires, and more particularly, to a bronze plated layer for improving adhesion to rubber without degrading adhesion to tire bead portion rubbers. The present invention relates to a method for manufacturing a low-plating adhesion amount bead wire for reinforcing tire bead parts, which can increase the plating work speed by reducing the thickness, thereby improving plating productivity and reducing plating solution.

Generally, as shown in FIG. 1, a tire for a vehicle includes a bead part B closely coupled to an outer circumferential surface of a rim (not shown) of a vehicle wheel, a tread T directly contacting a road surface during driving, and a bead part. Consists of the shoulder portion (S) and the side wall portion (C) to connect the tread portion and serves as a side wall of the tire, the steel cord (1) is embedded in the tread portion for reinforcement of the tire formed in the above shape, In the bead portion, a bead wire, which is a bead reinforcing steel wire, is embedded, and a carcass 3 is embedded along the entire tire cross section.

In the above, the carcass is the basic skeleton of a tire in rubber, which is constantly deformed between air and the road surface, so it is required to be particularly flexible and durable, so it is made of layers of cords. Use polyester, or braided steel cords with very thin steel wires.

The tire bead portion is a portion that serves to maintain a complete wheel shape on the wheel by the air pressure injected into the tire in contact with the rim of the wheel, the inside of the rubber layer constituting the bead portion to reinforce the strength of the rubber constituting the bead portion Bead wires to be embedded descaling → pickling → coating → primary drawing → heat treatment → pickling → coating → secondary drawing → degreasing → blurring → pickling → washing → active treatment → It is manufactured by processing and plating through a series of processes such as plating.

The bead wire manufactured as described above is bronze plated unlike the steel cord for brass plating, and the plating method is a kind of chemical plating, not electroplating or hot dip plating. When the plated material is deposited on the metal plating, metal ions in the plating solution form an alloy coating layer on the surface of the plated material by a catalytic chemical reaction thereof.

Looking at the conditions related to the degreasing treatment, activation treatment and plating operations associated with the plating in the bead wire manufacturing process are shown in Table 1 below.

Pretreatment Plated Degreasing Active treatment Temperature (℃) Concentration (N) Temperature (℃) Concentration (N) Temperature (℃) Acid concentration (N) Cu concentration (g / ℓ) Sn concentration (g / ℓ) Iron concentration (wt%) Plating speed (m / min) 40-70 1.0 or less 50-70 1.0-2.0 20 to 35 0.5 to 1.0 5 to 15 0.2-2.0 3 or less 300 or less

Sulfuric acid is used as the acid used in the activation treatment, and a weakly acidic aqueous solution having a low sulfuric acid concentration acts on the surface of the steel wire to provide a necessary activation energy in the plating process, thereby helping to form a plating layer.

The bronze plating layer thickness of the bead wire manufactured as mentioned above becomes about 0.1-0.2 micrometer. However, as the bead wire manufactured under the conventional plating conditions as described above, it is impossible to increase the plating flux due to maintaining the existing plating thickness and maintaining good adhesion with rubber, so that productivity improvement and cost reduction can no longer be expected, and environmental pollution prevention There is a problem that can not be suppressed to significantly increase the waste liquid management cost for.

As described above, the present invention is to solve all the problems of the conventional bead wire, it is possible to work at a faster plating speed than the conventional bead wire, while maintaining the adhesive force with the rubber even at a low plating amount to improve productivity In addition, it is an object of the present invention to provide a method for producing a low-plating amount of bead wire that can reduce the indirect production costs such as the direct production cost and waste liquid management costs associated with the plating liquid due to low plating amount.

1 is a partial cutaway perspective view of a radial tire for an automobile.

((Explanation of symbols for main part of drawing))

1. steel cord 2. bead wire

3. Carcass C. Sidewall Division

S. shoulder section T. tread section

The above object of the present invention is achieved by maintaining the combined conditions by adjusting the treatment temperature and acid concentration of the degreasing treatment, the activation treatment, and by adjusting the plating liquid temperature upward and the downward adjustment of the copper and tin concentration.

According to the present invention, a method of manufacturing a low-plating-adhesive bead wire provides a stable and uniform low-plating layer on the surface of a wire even at high plating speeds by appropriately controlling degreasing, activation, and plating conditions, which are related to plating pretreatment. There is a technical feature in the downward adjustment of the plating deposition amount within a range that can be maintained well without forming a drop in the adhesive force between the bead wire and the rubber for tires.

In addition, the bead wire manufactured by the method of the present invention has a bonding strength of not less than 0.03 to 0.06 μm, which is 1/3 to 1/6 level while having an adhesive strength equal to or higher than that of the rubber for tires, compared to conventional bead wires. There is a characteristic.

At this time, the minimum plating thickness is controlled to 0.03㎛ because the thinner the plating layer, the lower the adhesion to tire rubber can be caused, and if the maximum thickness is adjusted to 0.06㎛, the cost reduction and productivity improvement effect are exceeded. Because it is reduced.

Looking at the pre-treatment conditions for the plating operation of the bead wire of the present invention is shown in Table 2.

Pretreatment Plated Degreasing Active treatment Temperature (℃) Concentration (N) Temperature (℃) Concentration (N) Temperature (℃) Acid concentration (N) Cu concentration (g / ℓ) Sn concentration (g / ℓ) Iron concentration (wt%) Plating speed (m / min) 60 to 80 1.0 to 3.0 60 to 80 2.0 to 5.0 35 to 60 1.0 to 2.5 0.5 to 1.5 0.1-1.0 4 or less 350-450

Comparing the conditions of Table 2 with those of Table 1, which is a conventional manufacturing method, it can be seen that other concentrations and temperature conditions except for the concentration of copper and tin contained in the plating liquid are controlled upward.

That is, in the method of manufacturing the low-plating amount of the bead wire of the present invention, after degreasing of the non-plating material is completely performed by improving the degreasing force and the active force, the activity of the non-plating material is improved to be suitable for plating, and the temperature of the plating solution is raised. As a result, the plating adhesion amount at which the adhesion force with the tire rubber is ensured even under the plating metal concentration to be controlled downward is ensured, and the required time is reduced, thereby increasing the plating operation speed and improving productivity.

In addition, the materials used for the degreasing treatment and the active treatment are NaOH and sulfuric acid.

Through the following examples of the bead wire manufactured by applying the above pre-plating conditions and plating conditions, it will be clearly understood the specific working effects of the bead wire and the manufacturing method of the present invention.

After the secondary drawing, the carbon content was 0.82wt% and the steel wire having a diameter of 0.96mm was blued to give mechanical properties as a bead wire, and then bronze plating was completed. The plating conditions at this time are shown in Table 3 below.

division Plating solution concentration (g / ℓ) Working speed (m / min) Cu Sn Example One 0.803 0.154 350 2 1.092 0.153 3 1.163 0.172 Comparative example 4 5.042 1.465 280 5 6.321 1.523 6 7.635 1.628

In Table 3, it can be seen that the plating operation speed of the embodiment is more than 25% higher than that of the conventional comparative example, which is due to the change of the conditions of the degreasing and activation treatment and the control of the plating liquid temperature upward. The properties of each bead wire manufactured below are shown in Table 4 below.

division Plating layer composition (wt%) Plating layer thickness (㎛) Adhesion to rubber (kgf) Rubber 1 Rubber 2 Rubber 3 Cu Sn Average maximum at least Average maximum at least Average maximum at least Example 83-93 7-17 0.03 to 0.06 101.7 107.2 96.2 50.0 55.2 47.3 109.3 118.5 102.5 Comparative example 83-93 7-17 0.1 to 0.2 100.3 108.5 93.5 49.1 55.0 46.5 107.0 115.2 100.6

* The numerical values in Table 4 above are the numerical values obtained from the respective specimens of Examples and Comparative Examples.

It is comprehensive.

* Rubber 1,2,3 means rubber for tires with different composition.

Looking at Table 4, although the thickness of the plated layer of the embodiment bead wire of the present invention is significantly reduced compared to the conventional bead wire of the comparative example, the adhesion strength with the rubber is equal or more.

As described above, the bead wire manufactured by the method of the present invention has a good adhesive strength with the rubber is maintained even with a significantly thin plated layer compared to the conventional bead wire, thereby increasing the plating work speed, thereby improving the plating productivity and In addition, cost reduction by low plating amount can greatly increase the price competitiveness of the bead wire.

In addition, by using a plating solution with a low concentration of plated metal, significant reductions in waste plating solution processing costs and environmental management are expected. Therefore, sufficient production cost is reduced even when energy consumption increases due to degreasing solution, active liquid, and plating solution temperature rise. The effect is expected.

Claims (3)

delete A method for producing a bead wire used for reinforcing a bead portion of a car tire, comprising: a degreasing treatment having a temperature of 60 to 80 ° C. of a degreasing liquid and a concentration of 1.0 to 3.0 N of a degreasing agent to a bead wire before bronze plating; After the activation process of sulfuric acid active liquid temperature of 60-80 ° C. and sulfuric acid concentration of 2.0-5.0 wt% was sequentially performed, the concentration of Cu 0.5-1.5 g / l, the concentration of Sn 0.1-1.0 g / l, iron A method for producing a low-plating coating weight bead wire, characterized in that it is bronze plated in a plating solution at 35 to 60 ° C. having a concentration of 4 wt% and an acid concentration of 1.0 to 2.5 N. The method of manufacturing a low plating amount bead wire according to claim 2, wherein the method for producing a low plating amount bead wire has a plating operation speed in a range of 350 to 450 m per minute.