JP2002080876A - Lubricant composition for steel filament, steel filament treated therewith, and rubber/steel filament composite - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubricant composition used for the surface treatment of steel filaments in drawing them for enhancing the adhesion between steel filaments and a rubber. SOLUTION: The lubricant composition for steel filaments is formed by blending a mono alkali metal salt of triazinethiol, and/or at least one compound selected from boric acid and boric esters.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricant composition used in wire drawing of a steel filament constituting a steel cord used as a reinforcing material for a rubber article, a steel filament treated with the lubricant composition, and the steel. The present invention relates to a rubber-steel filament composite using a filament.

[0002]

2. Description of the Related Art Conventionally, a steel cord has been used as a reinforcing material for rubber articles such as automobile tires, hoses, conveyor belts, and the like. Brass plating is applied. However, simple brass plating alone is not sufficient in corrosion resistance, adhesion stability, wet adhesion, heat-resistant adhesion and the like.

In order to solve such a problem, various methods have been proposed. As one of the methods, there is a method of treating the surface of a steel filament with a lubricant in a wire drawing step. For example, Japanese Patent Application Laid-Open No. 5-185 discloses a method in which a triazine thiol derivative is added to a lubricant to perform surface treatment.
136 and JP-A-6-341073. However, even the steel filament surface-treated in this way still has insufficient adhesion to rubber. On the other hand, as a coating rubber for steel filament, there is a method of using a rubber composition obtained by compounding an organic acid cobalt salt having an adhesion promoting action in rubber. However, the cobalt salt of an organic acid shows a high adhesive strength immediately after vulcanization, but has a disadvantage of deteriorating the rubber properties during heat aging.

[Problems to be solved by the invention]

[0004] The present invention solves the above-mentioned problems, and provides a lubricant composition used for wire drawing of a steel filament.
And a steel filament treated with the lubricant composition and a rubber-steel filament composite using the steel filament.

[Means for Solving the Problems]

The present inventor has studied various substances to be added to a lubricant composition used in a steel filament drawing process, and when a compound described later is added to the lubricant composition and treated, the adhesiveness to rubber is improved. The present inventors have found that a steel filament excellent in the present invention can be obtained, and have completed the present invention.

[0006] The present invention resides in a lubricant for steel filaments, characterized by containing a triazinethiol monoalkali metal salt.

In the triazinethiol monoalkali metal salt, the metal element is preferably lithium, sodium or potassium.

Furthermore, it is preferable to blend at least one selected from boric acid and boric acid esters. Particularly, as the borate ester, it is preferable that the borate ester has 1 to 3 boron elements per molecule and has an alcohol residue having 1 to 4 carbon atoms.

Further, the present invention relates to a steel filament having the lubricant composition layer on the surface, and a rubber-steel filament composite comprising the steel filament and a rubber composition.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. In the present invention, the steel filament is drawn by an ordinary wet drawing method using a wet type drawing machine. In this case, the steel wire is drawn through a die attached to a lubrication tank of a wire drawing machine to a predetermined wire diameter. As the steel filament, unplated bare steel filament, copper-plated steel filament, brass-plated steel filament, nickel-plated steel filament, and the like can be used. The steel filament is subjected to surface treatment during wire drawing by the lubricant composition in the lubrication tank, and a lubricant composition layer is formed on the surface of the steel filament.

The lubricant composition is a so-called emulsion type emulsion in which an extreme pressure inhibitor, an oil agent, an emulsifier, a foam inhibitor and the like are dispersed in a solvent. As these components, those usually used in wet drawing can be appropriately selected and used. The present invention is characterized in that, in addition to the above-mentioned components, a lubricant composition is constituted by blending at least one selected from triazinethiol monoalkali metal salts or boric acid and borate esters.

The triazinetrithiol monoalkali metal salt is represented by the following general formula and can react with the metal surface and the double bond of the polymer to adhere them.

Embedded image

On the other hand, a diazine or trialkali metal salt of triazinetrithiol is not preferred because the hygroscopicity (deliquescence) of the chemicals is increased and the adhesiveness, especially the initial adhesiveness, is deteriorated.

The preferred amount of the triazine trithiol monoalkali metal salt is 1 to 40 parts by weight based on 100 parts by weight of the lubricant composition.

Further, boric acid or boric acid ester can be used in combination. In this case, it acts on a metal surface to form a film, blocks corrosion factors, exhibits a rust-preventive effect, and improves water-resistant adhesiveness. Can be done. As the borate ester, (CH ₃ O) ₃ B, (CH ₃ CH ₂ CH
₂ O) ₃ B and the like.

The amount of boric acid or boric acid ester is 1 to 40 parts by weight based on 100 parts by weight of the lubricant composition.

In the present invention, the steel filament is drawn by a wet wire drawing machine and, at the same time, is subjected to a surface treatment with the lubricant composition having the above-described structure, so that a lubricant composition layer, particularly a lubricant, is formed on the surface of the steel filament. A coating layer of triazinetrithiol monoalkali metal salt, or further boric acid and / or borate ester, in the components of the composition is formed. Although the formation mechanism of this coating layer is not clear,
It is estimated that: That is, when the steel filament passes through the lubricant composition, the components in the lubricant composition, particularly triazinetrithiol mono-alkali metal salt, or further boric acid and / or borate ester are adsorbed on the surface of the steel filament, When the wire is drawn by passing through a die in this state, the wire is firmly adhered to the surface to form a coating layer.

The steel filament thus treated is used as a monofilament cord or a plurality of twisted strands as a steel cord. When a plurality of strands are twisted, a partially untreated steel filament may be used. For use as a reinforcement for rubber articles, such cords are coated with a coating rubber to form a rubber-steel filament composite. The coating rubber is not particularly limited, and a commonly used rubber composition can be used. In the present invention, the above-mentioned lubricant composition layer, that is, a coating layer of triazinetrithiol monoalkali metal salt, or further boric acid and / or borate ester is present at the interface between the rubber and the steel filament of the composite. Is firmly adhered.

When the rubber-steel filament composite according to the present invention is used as a reinforcing material for a rubber article, the adhesion between the rubber and the steel filament is excellent, so that the steel filament peels from the rubber during use of the rubber article. Without this, the durability is remarkably improved.

[0020]

The present invention will be described below with reference to examples and comparative examples. According to the composition shown in Table 1, a lubricant composition and a rubber composition were prepared. First, brass plating (Cu:
(63% by weight, Zn: 37% by weight) was passed through the above-mentioned lubricant composition by a wet wire drawing machine and drawn to a wire diameter of 0.25 mm. A steel cord (1) is prepared using the steel filament thus treated.
× 5 structure). The steel cord is 12.5m
Samples of the rubber-cord composite were prepared by arranging the rubber composition in parallel at m intervals and bonding the rubber composition from both sides.

After vulcanizing each sample at 160 ° C. for 10 minutes, the steel cord was subjected to ASTM-D-222.
9 and the pulling force at that time was measured. Table 1 shows the measurement results as initial adhesiveness, and Comparative Example 1 shows 1
The index is indicated by an index of 00. In addition, it shows that adhesive strength is so large that a numerical value is large, and initial adhesiveness is favorable.

Next, each sample was subjected to a vulcanization treatment at 160 ° C. for 20 minutes, and further subjected to a heat deterioration treatment at 60 ° C. for 10 days, and the tensile strength of the rubber was measured. The measurement results are shown in Table 1 by the index notation with Comparative Example 1 being 100.
In addition, it shows that intensity | strength is so large that a numerical value is large.

[0023]

[Table 1]

From the results shown in Table 1, it can be seen that each of the examples has no change in the rubber properties and is excellent in the initial adhesiveness as compared with the comparative examples.

[0025]

As described above, triazine trithiol mono-alkali metal salt, or boric acid and / or borate ester is blended in the lubricant composition to perform a surface treatment during wire drawing of a steel filament. Thereby, a steel filament having excellent adhesion to rubber can be obtained. In addition, when a composite of a steel filament and rubber treated in this manner is used as a reinforcing material for a rubber article, it is possible to reduce the amount of the organic acid cobalt salt, and thus the durability of the rubber article without impairing the adhesiveness. Performance can be greatly improved.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C10N 40:32 C10N 40:32

Claims (6)

[Claims] 1. A lubricant composition for steel filaments, comprising a triazinethiol monoalkali metal salt. 2. The lubricant composition according to claim 1, wherein the metal element of the triazinethiol monoalkali metal salt is lithium, sodium or potassium. 3. The lubricant composition according to claim 1, further comprising at least one selected from boric acid and boric acid ester. 4. The method according to claim 1, wherein the borate is present in an amount of 1 to 1 per molecule.
The lubricant composition according to claim 3, wherein the lubricant composition has three boron elements and has an alcohol residue having 1 to 4 carbon atoms. 5. A steel filament characterized by having a lubricant composition layer on the surface thereof, wherein the lubricant composition layer comprises at least one selected from the group consisting of triazinethiol monoalkali metal salts and borate esters. 6. A lubricant composition layer comprising a rubber composition and a steel filament, and having at its interface a lubricant composition layer comprising at least one selected from triazine thiol monoalkali metal salts or further borate esters. Rubber-steel filament composite.