JPH01201454A - Composite material - Google Patents

Abstract

PURPOSE:To improve the adhesion between rubber and metallic material in a composite material to be obtained over the period ranging from the initial stage to the stages after heat aging and wet heat aging by constituting the above composite material of a rubber composition containing organic-acid cobalt salt and sulfur and a metallic material plated with Cu-Zn-Ni alloy. CONSTITUTION:A composite material is prepared by means, e.g., of embedding a metallic material, such as steel cord, plated with Cu-Zn-Ni ternary alloy in a rubber composition containing, based on 100pts.wt. of rubber 0.5-5pts.wt. organic-acid cobalt salt, such as cobalt stearate, and 1-7pts.wt. sulfur. Further, it is desirable that the above plating has a composition consisting of, by weight, 60-75% Cu, 0.1-20% Ni, and the balance Zn and also Co content in the organic-acid cobalt salt is regulated to 8-10%. By the above constitution, the composite material excellent in adhesive strength between the rubber after aging and the metallic material can be obtained, and accordingly, this material is suitable for vehicle tyre, conveyor belt, etc.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a composite material made of rubber and a metal material, which is used particularly for rubber industrial products such as vehicle tires and conveyor healds, and which This invention relates to a composite material with excellent adhesion between rubber and metal.

(Prior Art) In recent years, a wide variety of performances have been required of vehicle tires, conveyor belts, and the like. Especially in vehicle tires, radial tires have changed from passenger car tires to truck tires.
It has become a mainstream product, even in large tires for buses, and combined with advances in tread rubber compounding technology, tire life has been significantly improved. Further, after the first life of large tires for trucks and buses has ended, the tires are used for a second or even a third time by retreading the tread. Therefore,
Vehicle tire belts and carcass weigh approximately 100,000 kilograms.
It must withstand use for up to m.

The above-mentioned radial tire uses a steel cord material whose heald or carcass is coated with a rubber layer in order to improve its handling stability, structural durability, wear resistance, and puncture resistance.

In such tires, adhesion between rubber and metal becomes a problem.

Usually, rubber and metal materials are bonded together by the reaction between the sulfur mixed into the rubber during vulcanization and the copper in the plating of the metal material, forming sulfide at the interface between the rubber and metal materials. .

When this adhesion is broken due to heat generation due to hysteresis loss of the rubber material while the tire is running, the steel cord and its covering rubber layer separate, causing a so-called "severe lane" and making the tire unable to run.

Additionally, the tire trend or sidewall may be damaged during driving. If this damage reaches the steel cord material, the moisture that has entered through the damage vaporizes due to the heat generated during running and enters between the filaments of the steel cord, destroying the adhesion between the steel cord and its covering rubber, and causing the separation. induce.

Furthermore, if the air filled in the tire contains moisture, the moisture may enter from inside the tire, where the rubber is thin, and reach the steel cord, causing the same separation as described above.

Conventionally, in order to prevent this phenomenon, the adhesion between the rubber and the steel cord has been improved (an elaborate technique has been made public).

One of these is the technology of compounding the rubber that coats the steel cord.

It has been discovered since the 1950s that the adhesion can be improved by adding an organic acid cobalt salt to rubber, and many studies have been conducted on the amount and type of cobalt salt added. For example, JP-A-60-42440 discloses improving adhesion by optimizing the respective amounts of sulfur and organic acid cobalt salt. Further, an HR11 composition containing white carbon, resorcinol, and hexamethylenetetraamine has been proposed.

However, adding a large amount of organic acid cobalt salt causes deterioration of unvulcanized rubber and decreases adhesive strength due to high temperature vulcanization, long-term vulcanization, or heat aging after running, and HRH-based rubber compositions are susceptible to environmental pollution, Rubber baking has problems during production.

There are also techniques for improving the plating of metal materials.

Japanese Patent Publication No. 51-8389, Japanese Patent Publication No. 55-10554
No. 8 discloses a plating layer containing nickel,
Furthermore, alloy plating containing three to four types of metals,
JP-A-55-45884, JP-A-55-7188
Publication No. 7, JP-A-55-105548, JP-A-5
6-826045, JP 54-89940, JP 61-243194, and JP 61-7
This method is disclosed in Japanese Patent No. 2545 and the like.

(Problems to be Solved by the Invention) The present invention provides adhesive properties after heat aging and adhesive properties after heat aging (
To provide a composite material consisting of a rubber tread and a metal material that has improved heat resistance (hereinafter referred to as "heat resistance" and "temperature resistance") without causing other problems, especially problems during production. This objective is achieved by a combination of a metal material having an improved plating layer and a rubber having an appropriate formulation for the metal material.

(Means for Solving the Problems) The present invention provides a rubber composition containing 0.5 to 5 parts by weight of an organic acid cobalt salt and 1 to 7 parts by weight of sulfur per 100 parts by weight of rubber;・It is a composite material consisting of a metal material plated with a ternary alloy made of nickel.

Here, as the organic acid cobalt salt, cobalt naphthenate, cobalt oleate, cobalt maleate, cobalt stearate, etc. are applied, but in particular, those with a cobalt content of 8 to 10% are effective in terms of initial adhesion. preferable.

In addition, the shape of the metal material can be freely selected depending on the industrial product to which the composite material is applied, but when applying the composite material of the present invention to the conveyor belt or vehicle tire described above, the metal cord , especially used as steel cord.

The sulfur content is required to be 1 to 7 parts by weight. If it exceeds 7 parts by weight, the heat resistance will decrease, and if it is less than 1 part by weight, sufficient initial adhesive strength will not be obtained.

Next, the plating of metal materials used in the present invention is!
11. Requires ternary alloy plating consisting of zinc and nickel. The composition of this plating is 60 to 75% copper by weight.
A plating alloy containing 0.1 to 20% by weight of nickel and the remainder zinc is preferably used. If the copper content is less than 60% by weight, the initial adhesion strength will be poor, and if it exceeds 75% by weight, the nickel/zinc content will be reduced and the heat resistance and moist heat resistance will tend to be insufficient. Nickel does not require large amounts, but 2
If the position exceeds 0, the adhesive reaction will be inhibited and it will be difficult to obtain the necessary initial adhesive force.

A more preferred embodiment is 1 to 2 parts by weight per 100 parts by weight of rubber.
A rubber composition containing parts by weight of an organic acid cobalt salt, 4 to 6 parts by weight of sulfur, 4 to 10 parts by weight of nickel, and 60 to 6 parts by weight of nickel.
It is composed of a metal material plated with a ternary alloy consisting of copper, zinc, and nickel containing 75% by weight of copper.

(Example) Rubbers were prepared using the basic rubber formulation shown in Table 1, with varying amounts of sulfur and cobalt stearate based on FIG.

Table 1 Next, 1×510.25 steel cords were plated with the compositions shown in Table 2.

Table 2: Add the above cord to the above rubber at a cord density of 5 cords/cta
After making 120 kinds of samples buried in Visual evaluation was made using a 10-point scale. The result is the fourth
Shown in the table. A larger number represents a better result.

Conditions (a) in Table 3 are the initial adhesion strength measurement conditions, conditions (b) and (
c) shows the measurement conditions for heat and humidity resistance, and condition (d) shows the measurement conditions for heat resistance.

Rubber formulations 3 to 15 shown in FIG. 1 and Table 4 are applicable to the composite material of the present invention, and steel cords B-F shown in Tables 2 and 4 are applicable to the composite material of the present invention. Applicable steel cord.

As shown in Table 4, if there is too little sulfur and cobalt stearate, the initial adhesion will be poor, and if too much, the heat resistance will be poor.
When nickel is included in the plating composition of the steel cord, the moisture and heat resistance is improved.

Composite materials consisting of rubber compositions 3 to 15 according to the invention in combination with steel cords B to F showed good results under all conditions.

(Effects of the Invention) According to the present invention, the adhesion between rubber and metal materials is improved at the initial stage, after heat aging, and after wet heat aging, and
It has become possible to solve various problems during production of η dyeing, rubber firing, etc.

[Brief explanation of the drawing]

11 is a diagram showing the content of sulfur and cobalt stearate in the rubber composition used in the test. Patent applicant: Sumitomo Rubber Industries, Ltd.

Claims (4)

[Claims] (1) 0.0% organic acid cobalt salt per 100 parts by weight of rubber.
A composite material comprising a rubber composition containing 5 to 5 parts by weight of sulfur and 1 to 7 parts by weight of sulfur, and a metal material plated with a ternary alloy of copper, zinc, and nickel. (2) The composite material according to claim 1, wherein the composition of the ternary alloy plating is 60 to 75% by weight of copper, 0.1 to 20% by weight of nickel, and the remainder zinc. (3) 1 to 100 parts by weight of organic acid cobalt salt
a rubber composition containing 2 parts by weight and 4 to 6 parts by weight of sulfur;
Claim (1) characterized in that it consists of a metal material subjected to the ternary alloy plating containing 4 to 10% by weight of nickel.
) Composite materials listed. (4) The cobalt content of the organic acid cobalt salt is 8 to 1.
The composite material according to any one of claims (1) to (3), characterized in that the content is 0%.