JPS592293B2 - Rubber fittings - Google Patents

Description

Detailed Description of the Invention The present invention is characterized in that an aromatic linear polyester resin is blended into rubber, and after vulcanization, it has good adhesion to metal materials and fiber materials and good cut resistance. The present invention relates to a rubber composition.

Conventionally, when bonding rubber and a metal material such as a steel cord, or rubber and a fiber material such as a nylon cord, the former method is generally known by plating the surface of the steel or steel cord with a copper alloy such as brass or bronze. The latter method is generally known in which the surface of the nylon cord is treated with RFL liquid (resorcinol-formaldehyde-latex).

However, as automobile tires become faster, even higher adhesion strength is required, especially in vehicle tires. In recent years, in order to further improve the adhesive strength with metal materials and fiber materials, so-called H
RH systems have come into use.

However, due to the remarkable sublimation property of resorcinol, the HRH rubber composition generated smoke and odor during Banbury mixing or roll mixing, resulting in environmental pollution and poor workability. Recently, in order to improve the above-mentioned drawbacks of resorcin, a method of using an initial condensate of resorcin and formalin (such as BondingAgent R-6 manufactured by Uniroyal, Inc. in the United States) in place of resorcin in HRH rubber compositions has been known. (For example, special public relations
066) o However, in this case, there was a problem that the vulcanized physical properties of the rubber composition and the adhesiveness with metal materials and fiber materials were reduced. In addition, cut resistance of the tire tread is the most important characteristic in OTR (Off The Road) tires for civil engineering and construction and tires for trucks and buses used under high load conditions.

In the past, attempts have been made to improve these cut resistances by appropriately selecting diene polymers such as natural rubber and styrene-butadiene copolymers, and by incorporating carbon black and inorganic reinforcing agents. I came.

However, although cut resistance is improved to some extent by these methods, it is not satisfactory, and when the amount of carbon black or inorganic reinforcing agent is increased, the processability during compounding of the rubber composition decreases. The drawback was that the product generated a lot of heat during use.

Japanese Patent Publication No. 48-38615 discloses that a cyclopentadiene resin is added to a styrene-bumediene copolymer to improve the cut resistance of tielets, but this improvement is still unsatisfactory. isn't it. The purpose of the present invention is to improve the safety and hygiene of unvulcanized rubber compositions, improve the adhesion between rubber and metal materials or rubber and fiber materials after vulcanization, and further improve cut resistance. with the aim of
In particular, it is an object of the present invention to provide a rubber composition that can be used not only for tire overheads and carcass but also for tire inlets and other general rubber products.

The rubber composition of the present invention contains 1 to 100 parts by weight of the rubber substance.
It is characterized by blending 30 parts by weight of aromatic linear polyester resin.

The rubber material used in the present invention is natural rubber, synthetic rubber, or a mixture of natural rubber and synthetic rubber, and is vulcanizable.

The aromatic linear polyester resin used in the present invention is
It is a polyester resin obtained by polyesterifying an aromatic compound having two carboxyl groups with glycols.
NOH (n-3 to 20) polymethylene glycols,
8 General formula HO(CH2CH2O)NH(n-2~200
It is a polyester resin obtained by polyesterification with glycols such as polyethylene glycols (), alkylene glycols (8), glycols having an aromatic group between two -0H groups, and the like.

Further, it is desirable to add 1 to 30 parts by weight, preferably 5 to 20 parts by weight, of the aromatic linear polyester resin used in the present invention per 100 parts by weight of the rubber material. If more than 30 parts by weight is added, the hardness after vulcanization will increase, elasticity will be reduced, and heat generation will increase, making it impossible to put it into practical use. If it is less than 1 part by weight, the purpose of the present invention cannot be achieved. .

The present invention will be explained in more detail with reference to the following examples, but the present invention is not limited to these examples.

The formulations of Examples 1 to 7, Standard Example 1, and Comparative Examples 1 to 2 are shown in Table 1 below, and the test results are shown in Table 2.

(Preparation and vulcanization of rubber compound) A masterbatch was compounded in a Banbury mixer, and a vulcanization system was mixed therein with a roll to prepare a rubber compound.

Vulcanization for physical property testing was carried out at 145°C for 30 minutes. (Adhesion test with steel cord) A fabric (2 inches embedded) coated with a rubber compound on both sides of brass-plated steel cords arranged in parallel at 12.5 mm intervals was vulcanized at 145°C for 45 minutes, and then the steel cords were coated with a rubber compound. A pull test was conducted in accordance with ASTM D2229.

1 Examples 8 to 12, Standard Example 2, and Comparative Examples 3 to 4 were blended in the same manner as [1], and vulcanization and measurement were performed under the following conditions.

The combination recipe is shown in Table 3, and the results are shown in Table 4. The conditions for measuring physical properties were 148°C x 30 minutes. (Adhesion test with nylon cord) This was conducted in accordance with the H test according to ASTM D2138.

The vulcanization system was 148°C for 30 minutes, and the other conditions were the same as [D]. w Examples 13 to 15, standard example 3, and comparative example 5 [1] were blended in the same manner as in Example 13 to 15, standard example 3, and comparative example 5 [1], and vulcanization and measurement were performed under the following conditions.

The combination recipe is shown in Table 5, and the results are shown in Table 6. The conditions for measuring physical properties were 150°C x 30 minutes. (Cut resistance test: impact drop test) A 12.98k9 steel blade was placed on a vulcanized rubber test piece,
? Evaluation is based on the depth of the cut caused by dropping from a height of

However, the standard example was expressed as an index of 100. The larger the number, the greater the improvement effect. Second
From the table, it can be seen that the rubber composition according to the present invention has almost no change in vulcanized properties compared to conventional rubber compositions containing resorcinol, etc., but the adhesion strength to brass-plated steel cords is equal to or higher than that during mixing work. It is clear that there is no smoke or odor, and there is no blooming after blending. From Table 4, the physical properties of the rubber composition of the present invention are equivalent to conventional rubbers compounded with resorcinol, etc., and the adhesion strength to nylon cords is determined regardless of whether the nylon cords are untreated nylon cords or RFL-treated nylon cords. It is clear that the adhesive strength is almost the same as that of rubber compounded with resorcin, etc., and the adhesive strength is greatly improved compared to Standard Example 2 (no resorcin added).

Furthermore, the smoke generation properties during blending and the blooming properties of the blends are also significantly improved. From Table 6, it is clear that the rubber composition of the present invention has significantly improved cut resistance after vulcanization compared to the conventional rubber composition.

As explained above, the rubber composition of the present invention has excellent adhesion to steel cords or nylon cords and cut resistance, so it can be used as a new rubber kneading adhesive and as a cut resistance improver. Available.

Claims (1)

[Claims] 1 to the rubber substance, 1 to 30 per 100 parts by weight of the rubber substance
A rubber composition having good adhesion to metal materials or fiber materials and good cut resistance after vulcanization, characterized in that it contains a weight part of aromatic linear polyester resin.