Rubber composition for coating steel wire

Abstract

As tire lifespans increase, rubber compositions for steel wire coatings are required to maintain hardness and tensile strength while improving elongation at break, and to exhibit good adhesion to steel wires even after degradation. [Solution] The above problem was solved by a rubber composition for coating a steel wire coated with a metal plating compound, wherein the rubber composition contains 100 parts by mass of diene rubber including natural rubber, 40 to 80 parts by mass of a filler consisting of carbon black and / or silica, 1 to 16 parts by mass of basic magnesium sulfate fibers having an average length of 1 μm to 50 μm and an aspect ratio of 5 or more, and 3.5 parts by mass or more of zinc oxide, and the ratio of the basic magnesium sulfate fibers to the zinc oxide and the basic magnesium sulfate fibers is 5 to 60 mol%.

Description

Technical Field

[0001] The present invention relates to a rubber composition for coating steel wire, which improves the elongation at break while maintaining the hardness and breaking strength, and has good adhesion to steel wire even after deterioration.

Background Art

[0002] A pneumatic tire is mainly composed of a pair of left and right bead portions, sidewall portions, and a tread portion continuous with both sidewall portions. A carcass layer is provided inside the tire, and both ends of the carcass layer are folded back so as to wrap the bead core from the inside to the outside of the tire. The tread portion consists of a cap tread and an under tread, and a belt layer is disposed between the under tread and the carcass layer. Since a strong impact or a large load is applied to this belt layer, steel wire coated with a metal plating compound is used as a reinforcing material. The rubber that coats such steel wire requires good adhesion to the steel wire, and therefore, there is a method of blending an organic metal salt into the rubber. On the other hand, as the service life of the tire becomes longer, the rubber composition for coating steel wire is required to have good adhesion to the steel wire even after deterioration.

[0003] In addition, Patent Document 1 below discloses a rubber composition containing a rubber component, silica, and a water-soluble inorganic filler having a whisker structure, and the mass ratio [(a) / (b)] of the content (a) of silica to the content (b) of the water-soluble inorganic filler is 2.5 to 40. However, Patent Document 1 does not disclose or suggest any technical idea of blending basic magnesium sulfate fibers and zinc oxide into the rubber component, setting the blending amount of the zinc oxide to a specific amount or more, and applying the obtained composition to the use of coating steel wire to impart good adhesion to the steel wire even after deterioration.

Prior Art Documents

[0004] [Patent Document 1] International Open Brochure WO2020 / 121788 [Overview of the project] [Problems that the invention aims to solve]

[0005] The object of the present invention is to provide a rubber composition for coating steel wires that improves elongation at break while maintaining hardness and breaking strength, and that has good adhesion to steel wires even after deterioration. [Means for solving the problem]

[0006] As a result of diligent research, the inventors discovered that a rubber composition containing a specific composition of diene rubber, a specific amount of filler, zinc oxide, and basic magnesium sulfate fibers can solve the above problems, and thus completed the present invention.

[0007] In other words, the present invention is a rubber composition for coating a steel wire coated with a metal plating compound, The rubber composition contains, with respect to 100 parts by mass of diene rubber including natural rubber and / or synthetic isoprene rubber, 40 to 80 parts by mass of a filler consisting of carbon black and / or silica, 1 to 16 parts by mass of basic magnesium sulfate fibers having an average length of 1 μm to 50 μm and an aspect ratio of 5 or more, and 3.5 parts by mass or more of zinc oxide. The ratio of the basic magnesium sulfate fibers to the total amount of zinc oxide and basic magnesium sulfate fibers is 5 to 60 mol%. This invention provides a rubber composition for coating steel wires characterized by the following features. [Effects of the Invention]

[0008] The present invention relates to a rubber composition for coating a steel wire coated with a metal plating compound, wherein the rubber composition contains 100 parts by mass of a diene rubber including natural rubber and / or synthetic isoprene rubber, 40 to 80 parts by mass of a filler consisting of carbon black and / or silica, 1 to 16 parts by mass of basic magnesium sulfate fibers having an average length of 1 μm to 50 μm and an aspect ratio of 5 or more, and 3.5 parts by mass or more of zinc oxide, and the ratio of the basic magnesium sulfate fibers to the total zinc oxide and basic magnesium sulfate fibers is 5 to 60 mol%, so that a rubber composition for coating steel wire can be provided that improves the elongation at break while maintaining hardness and breaking strength, and has good adhesion to the steel wire even after deterioration.

[0009] The metals contained in the metal plating compound used to coat steel wires combine with sulfur in the rubber during vulcanization, resulting in adhesion between the rubber and the steel wire. However, these metals easily diffuse into the rubber, forming a depleted layer with reduced metal density. If a large amount of this depleted layer exists, there is a problem that delamination between the rubber and the steel wire may occur, for example, when humid heat degradation occurs, starting from this depleted layer. For example, if the metal plating compound is brass plating, copper ions and zinc ions combine with sulfur ions in the rubber during vulcanization, forming copper-sulfur compounds or zinc-sulfur compounds combined with zinc oxide. These enhance the adhesion between the rubber and the steel wire. However, copper and zinc easily diffuse into the rubber, and a depleted layer with reduced copper and zinc metal density forms on the steel wire side, creating a depleted layer, which may start from the aforementioned delamination. In this invention, by blending zinc oxide and basic magnesium sulfate fibers in specific amounts, the magnesium, which has a particularly high ionization tendency, contained in the basic magnesium sulfate fibers, is thought to suppress the excessive diffusion of metals contained in the metal plating compound coating the steel wire into the rubber, thereby minimizing the occurrence of the depletion layer. This makes it possible to maintain good adhesion and durability with the steel wire over a long period of time. Furthermore, since the basic magnesium sulfate fibers have a specific average length and aspect ratio and exhibit a so-called whisker-like shape, they act as a barrier to the diffusion of metal ions, which may also contribute to suppressing the occurrence of the depletion layer. [Modes for carrying out the invention]

[0010] The present invention will be described in more detail below. (Diene-based rubber) The diene rubber used in the steel wire coating rubber composition of the present invention comprises natural rubber (NR) and / or synthetic isoprene rubber (IR) as essential components. The amount of NR and / or IR is preferably 80 parts by mass or more when the total diene rubber is 100 parts by mass. Other diene rubbers besides NR and IR can also be used, such as butadiene rubber (BR), styrene-butadiene copolymer rubber (SBR), and acrylonitrile-butadiene copolymer rubber (NBR). These may be used individually or in combination of two or more. Furthermore, their molecular weight and microstructure are not particularly limited, and they may be end-modified with amine, amide, silyl, alkoxysilyl, carboxyl, hydroxyl groups, etc., or epoxidized. The weight-average molecular weight (Mw) of the diene rubber is not particularly limited, but for reasons that the effects of the present invention are superior, it is preferably 100,000 to 5,000,000, more preferably 200,000 to 3,000,000, and even more preferably 300,000 to 2,000,000. In this specification, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) are standard polystyrene equivalent values ​​obtained by gel permeation chromatography (GPC) measurement.

[0011] (Filler) The rubber composition for coating steel wires of the present invention incorporates a filler consisting of carbon black and / or silica. From the viewpoint of improving the effectiveness of the present invention, the nitrogen adsorption specific surface area (N2SA) of carbon black should be 30 to 100 m². 2 It is preferable that the concentration is / g. In this specification, the nitrogen adsorption specific surface area (N2SA) of carbon black shall be measured in accordance with JIS K6217-7. Furthermore, from the viewpoint of improving the effectiveness of the present invention, the specific surface area of ​​silica adsorbing CTAB is 100 to 200 m². 2 It is preferable that the value is / g. In this specification, the CTAB adsorption specific surface area of ​​silica is the value obtained by measuring the amount of n-hexadecyltrimethylammonium bromide adsorbed onto the silica surface in accordance with JIS K6217-3:2001 "Part 3: Method for determining specific surface area - CTAB adsorption method".

[0012] (Basic magnesium sulfate fiber) The basic magnesium sulfate fibers used in this invention can be obtained, for example, by hydrothermal synthesis using magnesium hydroxide and magnesium sulfate produced from seawater as raw materials, and this is well known.

[0013] Basic magnesium sulfate fibers can have the following structures: MgSO4·5Mg(OH)2·3H2O

[0014] The basic magnesium sulfate fibers used in this invention have an average length of 1 μm to 50 μm and an aspect ratio of 5 or more. By satisfying these conditions, the effects of this invention can be well expressed. Furthermore, from the viewpoint of improving the effects of this invention, the average length of the basic magnesium sulfate fibers is preferably 5 μm to 50 μm, more preferably 7 μm to 35 μm, and the aspect ratio is even more preferably 8 to 90. In addition, the average diameter of the basic magnesium sulfate fibers is preferably 0.5 μm or more and less than 1 μm. The average length, aspect ratio, and average diameter of basic magnesium sulfate fibers can be calculated from the short and long axes of 100 particles, as well as their respective average values, measured from magnified images obtained using a scanning electron microscope (SEM). Furthermore, the basic magnesium sulfate fibers used in the present invention are preferably poorly soluble in water. Specifically, the basic magnesium sulfate fibers used in the present invention are preferably 0.05 g / l or less in solubility in water at 0°C, and more preferably 0.04 g / l or less. The basic magnesium sulfate fibers used in this invention may be synthesized according to known methods, but they are also commercially available from Ube Materials Co., Ltd. as the Mosshydee series.

[0015] (Ratio of rubber composition) The rubber composition for coating steel wires of the present invention is characterized by containing 40 to 80 parts by mass of a filler consisting of carbon black and / or silica, 1 to 16 parts by mass of basic magnesium sulfate fibers having an average length of 1 μm to 50 μm and an aspect ratio of 5 or more, and 3.5 parts by mass or more of zinc oxide, with the ratio of the basic magnesium sulfate fibers to the total amount of zinc oxide and basic magnesium sulfate fibers being 5 to 60 mol%. If the amount of filler added is less than 40 parts by mass per 100 parts by mass of diene rubber, the hardness decreases. Conversely, if it exceeds 80 parts by mass, the elongation at break and adhesion to wires decrease. When the amount of basic magnesium sulfate fiber is less than 1 part by mass with respect to 100 parts by mass of the diene rubber, the amount is too small to exhibit the effects of the present invention. Conversely, when it exceeds 16 parts by mass, the breaking strength decreases. When the amount of zinc oxide is less than 3.5 parts by mass with respect to 100 parts by mass of the diene rubber, the adhesion to the steel wire after deterioration decreases. When the ratio of the basic magnesium sulfate fiber to the whole of zinc oxide and basic magnesium sulfate fiber is less than 5 mol%, the effects of the present invention cannot be achieved. Conversely, when it exceeds 60 mol%, the breaking strength and the adhesion to the steel wire after deterioration decrease.

[0016] From the viewpoint of improving the effects of the present invention, with respect to 100 parts by mass of the diene rubber, the amount of the filler is preferably 55 to 65 parts by mass, the amount of zinc oxide is preferably 5 to 15 parts by mass, the amount of the basic magnesium sulfate fiber is preferably 2 to 5 parts by mass, and the ratio of the basic magnesium sulfate fiber to the whole of zinc oxide and basic magnesium sulfate fiber is preferably 10 to 45 mol%.

[0017] In the amount of the filler, the amount of carbon black is preferably 5 to 30 parts by mass with respect to 100 parts by mass of the diene rubber, and the amount of silica is preferably 10 to 50 parts by mass.

[0018] From the viewpoint of improving the effects, it is more preferable that the rubber composition for coating a steel wire of the present invention satisfies one or more of the following conditions. (1) The rubber composition for coating a steel wire of the present invention further contains an organic acid cobalt salt in an amount of 0.05 to 2.0% by mass in terms of cobalt. Examples of the organic acid cobalt salt include cobalt naphthenate, cobalt neodecanoate, cobalt stearate, cobalt rosinate, cobalt versatic acid, cobalt tallate, cobalt neodecanoate borate, cobalt acetylacetonate, etc. Further, an organic acid cobalt salt containing boron, such as cobalt orthoborate, can also be used. (2) The rubber composition for coating steel wire of the present invention further comprises sulfur and a vulcanization accelerator, wherein the amount of sulfur is preferably 3 to 10 parts by mass per 100 parts by mass of the diene rubber. (3) The ratio of sulfur to the vulcanization accelerator is 2 to 35 by mass, preferably 10 to 25.

[0019] (Other ingredients) In addition to the components mentioned above, the rubber composition for steel wire coating of the present invention may contain various additives commonly used in rubber compositions, such as vulcanizing or crosslinking agents; vulcanizing or crosslinking accelerators; silane coupling agents; various other fillers such as clay and talc; various oils; antioxidants; and plasticizers. These additives can be mixed in a conventional manner to form a composition that can then be used for vulcanization or crosslinking. The amounts of these additives can also be conventional amounts, as long as they do not contradict the purpose of the present invention.

[0020] The steel wire coated with the rubber composition for steel wire coating of the present invention is coated with a metal plating compound. The metal plating compound is not particularly limited, but preferred examples include metal plating compounds selected from brass plating, copper-tin plating, copper plating, zinc plating, nickel plating, chromium plating, and copper-zinc-cobalt ternary plating.

[0021] Applications of the rubber composition for coating steel wires of the present invention include, for example, tires, belt conveyors, electric wires, hoses, and vibration-damping rubber. In the case of tire applications, steel wires coated with the rubber composition for coating steel wires of the present invention can be applied to belts embedded in the undertread, carcasses, beads (including the bead core and the steel wires housed therein), etc.

[0022] The rubber composition for coating steel wires of the present invention can be prepared, for example, by mixing the various components mentioned above using a general-purpose mixer such as a Banbury mixer or a roll mixer. By embedding steel wires in this composition and vulcanizing it according to a conventional method, it can be used for the various applications described above.

[0023] Furthermore, in the case of tire applications, the manufacturing method is not particularly limited, and tires can be manufactured according to known technologies. The tires are preferably pneumatic tires, and can be filled with air, inert gases such as nitrogen, and other gases. [Examples]

[0024] The present invention will be further described below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0025] Standard Example 1, Examples 1-4, Comparative Examples 1-5 In the formulations (parts by mass) shown in Table 1, the components excluding the vulcanization system (vulcanization accelerator, sulfur) were kneaded in a 1.7-liter sealed Banbury mixer for 5 minutes, then released from the mixer and cooled to room temperature to obtain an unvulcanized rubber composition. Subsequently, the vulcanization system was added, and the unvulcanized rubber composition was vulcanized at 170°C for 10 minutes to prepare test specimens, and the hardness (Hs), breaking strength (TB), and breaking elongation (EB) were measured. For the wire pull-out test (wire adhesion after hot water degradation), a wire was coated with the unvulcanized rubber composition, and the test specimens vulcanized under the above vulcanization conditions were immersed in hot water at 70°C for 4 weeks to perform hot water degradation treatment, and the test was conducted under the following conditions.

[0026] Hardness (Hs): Measured at 20°C in accordance with JIS K 6253. The results are shown as an index, with the value of Standard Example 1 set to 100. A higher index indicates higher hardness. The values ​​are expressed as exponents, with 100 as the baseline. A higher exponent indicates greater hardness. Breaking strength (TB): Tested at room temperature according to JIS K 6251. Results are shown as an index, with the value of Standard Example 1 set to 100. A higher index indicates higher breaking strength. Elongation at break (EB): Tested at room temperature according to JIS K 6251. Results are shown as an index, with the value of Standard Example 1 set to 100. A higher index indicates a higher elongation at break. Pull-out force: In accordance with ASTM D-2, steel wires were pulled from the test specimens after hot water degradation, and the pull-out force was measured. The results are expressed exponentially, with the value of Standard Example 1 set to 100. A higher value indicates better adhesion to rubber after hot water degradation. Rubber Adhesion Amount: In accordance with ASTM D-2229, the amount of rubber adhesion was measured by pulling out steel wires from the test specimens after hot water degradation. The results are expressed exponentially, with the value of Standard Example 1 set to 100. A higher value indicates better adhesion to rubber after hot water degradation. The results are shown in Table 1.

[0027] [Table 1]

[0028] *1: NR (RSS#3) *2: Carbon Black HAF (Seas 3 manufactured by Tokai Carbon Co., Ltd.) *3: Silica (Precipitated silica K160 manufactured by FengHai Rice Biotechnology) *4: Silane coupling agent (Si69 manufactured by Evonik DeGussa, bis(3-triethoxysilylpropyl)tetrasulfide) *5: Zinc oxide (3 types of zinc oxide manufactured by Seido Chemical Industry Co., Ltd.) *6: Magnesium sulfate 1 (USN-00 manufactured by Maiko Chemical Industries Co., Ltd., particle size = 3-6 μm, aspect ratio = 1-2) *7: Magnesium sulfate 2 (magnesium sulfate manufactured by Kanto Chemical Co., Ltd., average length = 250 μm, aspect ratio = 2.5) *8: Basic magnesium sulfate fiber (MossHydee manufactured by Ube Materials Co., Ltd., average length = 10 μm, aspect ratio = 22, average diameter = 0.5 μm) *9: Anti-aging agent (Flexis Santoflex 6PPD) *10: Organic cobalt acid salt (DICNATE NBC-II, manufactured by DIC Corporation; cobalt borate neodecanoate) *11: Sulfur (Crystex HT OT 20, manufactured by AkzoNobel Co., Ltd.) *12: Vulcanization accelerator DZ (Noxellar DZ manufactured by Ouchi Shinko Chemical Industry Co., Ltd.)

[0029] As shown in Table 1, the rubber composition of each example contains 100 parts by mass of diene rubber including natural rubber and / or synthetic isoprene rubber, 40 to 80 parts by mass of a filler consisting of carbon black and / or silica, 1 to 16 parts by mass of basic magnesium sulfate fibers having an average length of 1 μm to 50 μm and an aspect ratio of 5 or more, and 3.5 parts by mass or more of zinc oxide. The ratio of the basic magnesium sulfate fibers to the total zinc oxide and basic magnesium sulfate fibers is 5 to 60 mol%, thus improving the elongation at break while maintaining hardness and breaking strength, and having good adhesion to steel wire even after degradation. On the other hand, Comparative Example 1 is an example in which magnesium sulfate 1 with an aspect ratio of 1 to 2 was used instead of basic magnesium sulfate fibers, resulting in reduced elongation at break and decreased wire adhesion after hot water degradation. Comparative Example 2 is an example in which magnesium sulfate II with an average length of 250 μm was used instead of basic magnesium sulfate fibers, resulting in decreased tensile strength and elongation at break, and reduced wire adhesion after hot water degradation. In Comparative Example 3, the tensile strength decreased because the proportion of basic magnesium sulfate fibers exceeded the upper limit specified in the present invention. In Comparative Example 4, the proportion of zinc oxide used was below the lower limit specified in the present invention, resulting in reduced wire adhesion after hot water degradation. In Comparative Example 5, the ratio of basic magnesium sulfate fibers to the total zinc oxide and basic magnesium sulfate fibers exceeded the upper limit specified in the present invention, resulting in reduced tensile strength and decreased wire adhesion after hot water degradation.

[0030] Standard Example 2, Examples 5-8, Comparative Examples 6-10 In the aforementioned "Standard Example 1, Examples 1-4, and Comparative Examples 1-5," the process was repeated except that the blending amounts (parts by mass) of each raw material were changed as shown in Table 2. The results are shown in Table 2. Examples 5-8 and Comparative Examples 6-10 are compared with Standard Example 2.

[0031] [Table 2]

[0032] As shown in Table 2, the rubber composition of each example contains 100 parts by mass of diene rubber including natural rubber and / or synthetic isoprene rubber, 40 to 80 parts by mass of a filler consisting of carbon black and / or silica, 1 to 16 parts by mass of basic magnesium sulfate fibers having an average length of 1 μm to 50 μm and an aspect ratio of 5 or more, and 3.5 parts by mass or more of zinc oxide. The ratio of the basic magnesium sulfate fibers to the total zinc oxide and basic magnesium sulfate fibers is 5 to 60 mol%, thus improving the elongation at break while maintaining hardness and breaking strength, and having good adhesion to steel wire even after degradation. On the other hand, Comparative Example 6 is an example in which magnesium sulfate 1 with an aspect ratio of 1 to 2 was used instead of basic magnesium sulfate fibers, resulting in reduced elongation at break and decreased wire adhesion after hot water degradation. Comparative Example 7 is an example in which magnesium sulfate II with an average length of 250 μm was used instead of basic magnesium sulfate fibers, resulting in decreased tensile strength and elongation at break, and reduced wire adhesion after hot water degradation. In Comparative Example 8, the tensile strength decreased because the proportion of basic magnesium sulfate fibers exceeded the upper limit specified in the present invention. In Comparative Example 9, the proportion of zinc oxide used was below the lower limit specified in the present invention, resulting in reduced wire adhesion after hot water degradation. In Comparative Example 10, the ratio of basic magnesium sulfate fibers to the total zinc oxide and basic magnesium sulfate fibers exceeded the upper limit specified in the present invention, resulting in reduced tensile strength and decreased wire adhesion after hot water degradation.

[0033] This disclosure encompasses the following inventions: Embodiment 1: A rubber composition for coating steel wires coated with a metal plating compound, The rubber composition contains, with respect to 100 parts by mass of diene rubber including natural rubber and / or synthetic isoprene rubber, 40 to 80 parts by mass of a filler consisting of carbon black and / or silica, 1 to 16 parts by mass of basic magnesium sulfate fibers having an average length of 1 μm to 50 μm and an aspect ratio of 5 or more, and 3.5 parts by mass or more of zinc oxide. The ratio of the basic magnesium sulfate fibers to the total amount of zinc oxide and basic magnesium sulfate fibers is 5 to 60 mol%. A rubber composition for coating steel wires, characterized by the following features. Embodiment 2: The rubber composition for coating steel wires according to Embodiment 1, further characterized in that it contains 0.05 to 2.0% by mass of an organic acid cobalt salt as cobalt. Embodiment 3: The rubber composition for coating steel wires according to Embodiment 1 or 2, further comprising sulfur and a vulcanization accelerator, wherein the amount of sulfur is 3 to 10 parts by mass per 100 parts by mass of the diene rubber, and the ratio of sulfur to vulcanization accelerator is 2 to 35 by mass. Embodiment 4: The rubber composition for coating steel wire according to any one of Embodiments 1 to 3, characterized in that when the total diene rubber is 100 parts by mass, the natural rubber and / or synthetic isoprene rubber accounts for 80 parts by mass or more. Embodiment 5: A rubber composition for coating steel wire according to any one of Embodiments 1 to 4, characterized in that, with respect to 100 parts by mass of the diene rubber, the amount of carbon black is 5 to 30 parts by mass and the amount of silica is 10 to 50 parts by mass. Embodiment 6: The rubber composition for coating steel wire according to any one of Embodiments 1 to 5, characterized in that the metal plating compound is a metal plating compound selected from brass plating, copper-tin plating, copper plating, zinc plating, nickel plating, chromium plating, and copper-zinc-cobalt ternary plating. Embodiment 7: A tire, belt conveyor, electric wire, hose, or vibration-damping rubber using the steel wire coating rubber composition described in any of Embodiments 1 to 6.

Claims

1. A rubber composition for coating steel wires coated with a metal plating compound, The rubber composition contains, with respect to 100 parts by mass of diene rubber including natural rubber and / or synthetic isoprene rubber, 40 to 80 parts by mass of a filler consisting of carbon black and / or silica, 1 to 16 parts by mass of basic magnesium sulfate fibers having an average length of 1 μm to 50 μm and an aspect ratio of 5 or more, and 3.5 parts by mass or more of zinc oxide. The ratio of the basic magnesium sulfate fibers to the total amount of zinc oxide and basic magnesium sulfate fibers is 5 to 60 mol%. A rubber composition for coating steel wires, characterized by the following features.

2. The rubber composition for coating steel wires according to claim 1, further comprising 0.05 to 2.0% by mass of an organic acid cobalt salt as a cobalt content.

3. The rubber composition for coating steel wires further comprises sulfur and a vulcanization accelerator, wherein the amount of sulfur is 3 to 10 parts by mass per 100 parts by mass of the diene rubber, and the ratio of sulfur to vulcanization accelerator is 2 to 35 by mass, as described in claim 1.

4. The rubber composition for coating steel wires according to claim 1, characterized in that when the total diene rubber is 100 parts by mass, the natural rubber and / or synthetic isoprene rubber accounts for 80 parts by mass or more.

5. The steel wire coating rubber composition according to claim 1, characterized in that, with respect to 100 parts by mass of the diene rubber, the amount of carbon black is 5 to 30 parts by mass and the amount of silica is 10 to 50 parts by mass.

6. The rubber composition for coating steel wires according to claim 1, characterized in that the metal plating compound is a metal plating compound selected from brass plating, copper-tin plating, copper plating, zinc plating, nickel plating, chromium plating, and copper-zinc-cobalt ternary plating.

7. A tire, belt conveyor, electric wire, hose, or vibration-damping rubber using the steel wire coating rubber composition described in claim 1.

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