KR100270171B1 - Steel cords for reinforcement of rubber articles - Google Patents

Abstract

According to the present invention, in a steel cord two-layer lead (n + m) structure consisting of a core wire and a side wire, the entire core wire cord twisted with two to three filaments (n) is passed through a pre-sided serrated roller to create a spiral deformation on the surface. The steel cord for reinforcing rubber products, which improves the rubber penetration force by extending the interval between the side filaments by twisting 4-10 strands of side filament (m) thereon. When the rubber is rolled up and down in the direction of steel cord (shorter diameter) with a wider gap between the side filaments, the thickness of the rubber can be reduced and the rubber penetration force to the steel cord can be improved. Its advantage is that the range of use is wide for product reinforcement.

Description

Steel cord for rubber product reinforcement

The present invention relates to a steel cord for reinforcing rubber products, and more specifically, in a two-layered steel steel cord, the rubber is subjected to a certain distance to the side cord by applying a spiral deformation to the whole core cord before twisting the side cord, The present invention relates to a steel cord for reinforcing rubber products further improving penetration.

Steel cords are alloy-plated with 1 to 4 elements selected from copper, zinc, nickel, cobalt and tin with a thickness of 0.1 to 0.4 mm in a wire rod of 0.1 to 0.4 mm in diameter made of carbon steel with carbon content of 0.6 to 0.95% by weight. After that, the wire is twisted into various structures (1 × 3, 1 × 4, 2 + 2, 2 + 7, 3 + 6, 3 + 9 + 15, etc.) according to the application. The strength, modulus, heat resistance It is used to reinforce rubber products such as tires and conveyor belts because of its excellent fatigue resistance compared to other types of inorganic and organic fibers.

In addition, the structure of a conventional steel cord is simply twisted two to three strands of filament to produce a core cord, and four to 10 strands of the filament twisted together to produce a side cord cord (layer cord + core cord + It is widely used for reinforcing belt and carcass parts of heavy duty tires such as trucks and buses.

As described above, the steel cord should be excellent in adhesion with rubber, which is a heterogeneous material because it is used as a reinforcement material for tires, and should be excellent in the harsh environment formed while the vehicle is driving. Efforts have been made.

U.S. Patent No. 3,032,963 discloses a commonly used steel cord two-layer lead 3 + 6 structure, while U.S. Patent No. 3,336,774 discloses a steel cord two-layer lead two +6 structure. Since the steel cord does not penetrate the inside of the steel cord, the rubber cord does not penetrate the inside of the steel cord. There is a problem.

In order to solve this problem, U.S. Patent No. 4,586,324 proposed a 2 + 5 structure with fewer side players than the existing 2 + 6 structure, and Japanese Laid Open No. 63-256782 had fewer side players than the existing 3 + 9 structure. A 3 + 8 structure is proposed. However, the method of making the side bow less than the conventional method has difficulty in uniformly matching the spacing between the filaments in the twisted pair process of twisting the side line, so that there is a nonuniformity between the wide spacing between the filaments and the narrow spacing between the filaments.

In Japanese Laid-Open Publication Nos. 5-279973 and 8-13363, one of three strands constituting the core in a 3 + 6 steel cord is provided with a spiral deformation before twisting to give twist. Steel cords have been proposed to improve the rubber penetration by increasing the diameter of the cord slightly to widen the gap between the side filaments. However, in this case, when a spiral strain is applied to one strand of the core filament, an excessive stress is likely to cause a disconnection phenomenon in which the line breaks, and only one strand of the core filament gives a spiral deformation to increase the distance between the side lines. The effect was so small that the improvement of rubber penetration was not so improved.

The present invention overcomes the above-mentioned problems in the prior art, by providing a spiral deformation to the entire core wire cord, and by twisting the side wire, thereby widening the interval between the side filaments, greatly improving the rubber penetration force, and producing less disconnection in the twisted wire process. It is to provide an easy steel cord.

1 (a) and (b) are cross-sectional views of a conventional 3 × 0.20 + 6 × 0.35 steel cord,

Figure 2 (c) and (d) is a cross-sectional view of the present invention 3 × 0.20 + 6 × 0.35 steel cord,

3 is a front view of a 3 × 0.20 + 6 × 0.35 steel cord of the present invention.

That is, in the present invention, in the steel cord two-layer lead (n + m) structure consisting of core and side lines, the entire core wire cord twisted with two to three filaments (n) is passed through a tooth roller before side twisting to form a spiral deformation. After providing, 4-10 strands of side filament (m) are stranded on it, and the space | interval between side line filaments is extended, and the steel cord for reinforcement of rubber products which improved rubber penetration force is provided.

Hereinafter, the present invention will be described in more detail.

Steel cord of the present invention is a two-layered steel cord structure consisting of a core wire and a side wire, as shown in Figure 3, twisted two to three strands of filament generally used for steel cord to the core cord and then to the core cord Spiral strain is applied to the core surface by passing a toothed roller having a constant strain rate, and then stranded with 4 to 10 sideline filaments thereon, and spaced between each sideline filament as shown in (c) and (d) of FIG. To be uniformly generated periodically from as narrow as 0.1mm to as wide as 2.0mm.

At this time, the strain pitch P2 of the core cord passed through the feed roller is 0.5 to 2.5 times the core cord pitch P1, and the strain peak D2 of the core cord is 1.1 to 5.0 times larger than the cord diameter of the core cord. do. Such strain pitch and strain height of the core wire cord can be easily adjusted by changing the pitch of the feed roller and the depth of the groove.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following Examples are only for the purpose of description and the present invention is not limited by the following Examples.

Example 1

As shown in Table 1 below, twisted filament 3 strands of 0.20 mm diameter were made to produce core cords, and after the spiral deformation was applied, 6 strands of filament 0.35 mm in diameter were stranded on the core cords to provide a 3 × 0.20 + 6 × 0.35 structure. Steel cords were prepared, and their physical properties were evaluated and shown in Table 1 below.

Example 2

After twisting three strands of 0.175mm diameter filament to produce a core cord, and giving spiral deformation, the strands of 0.175mm diameter filament were stranded on the core cord to manufacture a steel cord having a 3 + 9 × 0.175 structure according to the present invention. The evaluation is shown in Table 1 together.

Example 3

Core wire cord was prepared by twisting three strands of 0.22mm diameter filament, and after the spiral deformation was applied, 9 strands of filament 0.22mm diameter were stranded on the core cord to prepare a steel cord of the present invention 3 + 9 × 0.22 structure, and evaluated physical properties. The results are shown in Table 1 below.

Comparative Example 1

Core cord was prepared by twisting three strands of 0.20mm diameter filament, and six strands of 0.35mm diameter filament were stranded on the core cord to manufacture a steel cord having a conventional 3 × 0.20 + 6 × 0.35 structure as shown in FIG. Then, the physical properties were evaluated and the results are shown in Table 1 below.

Comparative Example 2

Spiral strain is applied to one strand of filament 0.20 mm in diameter, twisted together with two strands of filament that are not helically deformed, and the core cord is manufactured, followed by stranding six filament strands of 0.35 mm diameter on the core cord. Steel cord having a 3 × 0.20 + 6 × 0.35 structure as shown in Korean Patent Application Laid-Open No. 5-279973) was prepared, and the results of evaluation of physical properties are shown in Table 1 below.

Comparative Example 3

Core cord is prepared by twisting three strands of 0.175mm diameter filament, and nine strands of filament 0.175mm diameter are stranded on the core cord to prepare a steel cord having a conventional 3 + 9 × 0.175 structure. Table 1 shows.

Comparative Example 4

Core cord was prepared by twisting three strands of 0.22mm diameter filament and 9 strands of 0.22mm diameter filament were stranded on the core cord to prepare a steel cord having a conventional 3 + 9 × 0.22 structure, and evaluated for physical properties. 1 is shown.

Physical property measurement method used in the present invention is as follows.

1) rubber adhesion

ASTM D-2229 was applied, and the applied compound used Korean A tire rubber.

2) Rubber Permeability (CC / min)

After the steel cord was vulcanized with rubber, a rubber block sample (length 14 mm) was prepared, and the compressed air was blown to one end of the steel cord to evaluate the amount of air coming out from the opposite side.

In addition, in Table 1

P1: twisted pitch of core cord, D1: cord diameter of core cord,

P2: Twist pitch of side cord, D2: Cord diameter of steel cord,

When the long and short diameters of the core cord and steel cord are present, both the long and short diameters are marked.

Steel cord structure Core cord Siding code Rubber Adhesion (Kg / 2inch) Rubber permeability (cc / min) Comparative Example 1 3 × 0.20 + 6 × 0.35 P1 = 10mm D1 = 0.43mm P2 = 18mm D2 = 1.13mm 150 50 Comparative Example 2 3 × 0.20 + 6 × 0.35 core wire 1 strand spiral deformation P1 = 10mm D1 = 0.45mm P2 = 18mm D2 = 1.15mm 155 45 Example 1 3 × 0.20 + 6 × 0.35 Core Cord Spiral Deformation P1 = 10mm long diameter = 65mm short diameter = 43mm P2 = 18mm long diameter = 1.33mm short diameter = 1.13mm 190 5 Comparative Example 3 3 + 9 × 0.175 P1 = 10mm D1 = 0.38mm P2 = 12mm D2 = 0.73mm 80 45 Example 2 Inventive 3 + 9 × 0.175 core cord spiral deformation P1 = 10mm Long Diameter = 0.65mm Short Diameter = 0.43mm P2 = 12mm Long Diameter = 0.95mm Short Diameter = 0.73mm 95 5 Comparative Example 4 3 + 9 × 0.22 P1 = 12mm D1 = 0.47mm P2 = 12mm D2 = 0.91mm 110 55 Example 3 3 + 9 × 0.22 core cord spiral deformation P1 = 12mm Long Diameter = 0.65mm Short Diameter = 0.43mm P2 = 12mm Long Diameter = 1.13mm Short Diameter = 0.91mm 125 5

As described above, the surface of the core cord is deformed before the side twist is applied to give a certain interval between the side filaments, so that no fritting occurs due to the friction between the filaments during tire manufacture and after use, and the fatigue resistance is excellent. In addition to extending the service life of the tire, and also by providing a spiral deformation in the left and right direction to the core wire cord, it is possible to reduce the thickness of the rubber when rolling the rubber up and down in the direction of steel cord (short diameter) with a large distance between the side filaments, It is possible to improve rubber penetration into steel cords.

Therefore, the steel cord of the present invention is advantageous in that the use range is wide for the reinforcement of rubber products such as high pressure hoses, conveyor belts as well as tire applications.

Claims (3)

In the steel cord two-layer lead (n + m) structure consisting of a core wire and a side wire, the entire core wire cord twisted with two or three filaments (n) is passed through a tooth roller before side twisting to impart a spiral deformation, Steel cord for reinforcement of rubber products, which improves rubber penetration by extending the distance between the side filaments by stranding the side filaments (m) of ˜10 strands. 2. The strain pitch P2 of a core cord provided with a waveform strain to the core cord before sideline twist is 0.1 to 0.5 times the twist pitch P1 of the core cord, and the strain peak D2 of the core cord is a core cord. Steel cord for reinforcing rubber products, characterized in that 1.1 to 3.0 times larger than the diameter (D1). The steel cord for reinforcing rubber products according to claim 1, wherein the core cord is helically deformed in the lateral direction to have a long diameter / short diameter ratio of 1.1 to 3.0.