JPS6035935B2 - Adhesion method of metal and rubber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for adhering metal and rubber. For example, when manufacturing automobile tires (steel tires) or industrial rubber belts in which metal filaments are embedded, metal and rubber as reinforcing filaments are bonded. This relates to a method of improving adhesion with.

BACKGROUND ART For a long time, steel tires with embedded metal stripes have been widely used in order to improve the tires' high-speed durability and high-speed stability. Furthermore, industrial rubber belts with metal wire bodies embedded therein are often used indoors and outdoors for transporting heavy objects. These automobile tires and rubber belts require strong adhesion between the rubber and the metal filament as a reinforcing material embedded therein, so the metal filament with galvanized plus plating (Cu-Zn) is used on the surface. , in combination with rubbers mixed with organic cobalt salts, such as cobalt naphthenate, have been used in the past. In addition,
In addition to the above-mentioned organic cobalt salt, rubber containing HRH or high sulfur is also used in brass plating on the surface of the metal filament. When using rubber containing organic cobalt salt (hereinafter referred to as cobalt compound rubber),
Usually, 1 to 1 part by weight of Atsushi is blended with 100 parts by weight of rubber, and the mixture is mixed using a roll. However, the composite of the cobalt-based compounded rubber and the metal filament thus obtained did not necessarily have sufficient adhesive properties over a long period of time. The reason for this is not fully understood today, but organic cobalt salts gradually react due to the effects of vulcanization accelerators, anti-aging agents, and other additives blended into the rubber, as well as moisture absorption. It is assumed that this causes the rubber to deteriorate. For these reasons,
Simply increasing the amount of cobalt blended into rubber to improve long-term adhesion between rubber and metal has little effect, and instead has a negative effect on rubber elasticity and causes problems such as recovery during overvulcanization. Besides the problem, the use of expensive organic cobalt salt increases the cost of the product. By the way, when metal and rubber are bonded using a steel tire or a rubber belt, the bonding interface is of the order of lr, and the bonding properties at this point are particularly problematic.

For this reason, the inventors conducted various experiments to improve this adhesive interface, and the results showed that when bonding metal and rubber, expensive organic cobalt salt "exists only as a thin film at the adhesive interface between the two." It was discovered that if a large amount of organic cobalt salt was blended throughout the unvulcanized rubber as in the past, the properties of the rubber itself would be lost, and this invention was thus completed. In other words, this invention involves a metal surface plated with copper, zinc, copper-zinc, zinc-cobalt, or copper-zinc-cobalt, and unvulcanized rubber with a thin film of organic cobalt salt interposed therebetween. The method is characterized in that the unvulcanized rubber is vulcanized.

The details of this invention will be explained below regarding the steel cord used in steel tires. After steel-zinc-cobalt plating, it is drawn into a cord. In this case, the plating thickness is 0.1 or more, preferably 0.
．． 2 mm or more, and the wire diameter after final wire drawing is 0.1 to 0.5 ribs. Organic cobalt salt is applied to the surface of the cord thus obtained.
For example, cobalt naphthenate, cobalt stearate, and cobalt rosin acid are diluted with a solvent, sprayed in small amounts, and dried to form a thin film.The solvent used here is toluene, xylene, and all other ordinary organic solvents. Next, this cord is embedded in a rubber compound according to a conventional method and vulcanized under appropriate pressure and heating conditions to make a steel tire with the cord embedded in rubber.The organic cobalt salt is As mentioned above, it is not necessarily necessary to apply the coating to the surface of the metal cord, but it may be applied to the bonding surface of the unvulcanized rubber cord to be bonded to it in the same manner as above. According to the present invention, an expensive organic cobalt salt can be formed between Cu, Zn, Cu-Zn, Zn-Co, Cu-
Even though only a small amount of Zn-Co was used as a thin film at the interface between the metal and the unvulcanized rubber, a composite with strong adhesion between the metal and the rubber was obtained, and its adhesive strength will be explained later. As shown in the examples, it can be seen that the performance is equivalent to or better than when using a vulcanized rubber in which an organic cobalt salt is blended into the entire unvulcanized rubber.

It can be seen that other properties such as pulling force and rubber adhesion are also excellent. Example 1 Surface galvanized, brass plated (Cu=66%)
Three types of 1 x 5 x 0.25-legged cords, each coated with zinc-cobalt plating (Co = 10%), were coated with a gloin solution containing 1% by volume of cobalt naphthenate, and then coated with a gloin solution that did not contain cobalt. Vulcanized rubber was adhered and vulcanized in a mold.

After the heating process was completed, the pulling force and rubber adhesion rate of the cooled Shishita were examined in comparison with those without the cobalt salt thin film, and the results were as shown in Table 1. Note that the adhesion test method was conducted according to ASTM. Table 1 Example 2 The same procedure as Example 1 was carried out except that cobalt naphthenate was not applied to the surface of the metal cord but to the unvulcanized rubber side.

When the results were compared with those using cobalt compounded rubber, the results were as shown in Table 2. Table 2

Claims (1)

[Claims] 1 Copper, zinc, copper-zinc, zinc-cobalt, copper-zinc-
A metal surface plated with any one of cobalt and unvulcanized rubber is brought into close contact with a thin film of organic cobalt salt interposed therebetween, and then the unvulcanized rubber is vulcanized. Rubber bonding method.