KR20040012063A - A rubber composition for tire-tube - Google Patents

Abstract

PURPOSE: A rubber composition for tire tube with improved adhesiveness while maintaining its resistance to air-permeability, thereby enhancing the adhesiveness in tube joint and further preventing accidents caused by tube failure, is provided by adding a certain amount of epoxidized natural rubber to butyl rubber, as a base rubber. CONSTITUTION: The rubber composition for tire tube comprised of butyl rubber as a base rubber, carbon black, zinc oxide, stearic acid, processing oil, accelerating agent, and vulcanizing agent comprises 10-30 pts.wt of epoxidized natural rubber based on 70-90 pts.wt. of butyl rubber as a base rubber.

Description

A rubber composition for tire-tube

The present invention relates to a tube rubber composition for a tire, and more particularly, to improve adhesion of a tube rubber to improve adhesion of a tube joint part, thereby reducing the defect of the tube during the manufacture of the tube, and occurring when used in actual tire mounting. It relates to a tube rubber composition for a tire that can prevent the tube accident to be prevented.

In general, a vehicle tube is mounted inside a tube-type tire such as a bias tire and a radial tire to maintain air pressure.

Since such automotive tubes have the purpose of maintaining the injected air pressure, the raw material rubber mainly uses butyl rubber having good air permeability.

Such butyl rubber has a problem in that air permeability is good, while adhesiveness is poor, and thus, a lot of manufacturing defects are generated due to the unevenness of the tube when the tube rubber is manufactured.

In order to compensate for such drawbacks, an adhesive may be added, but since the butyl rubber used as a raw material rubber is very poor, no satisfactory effect has been shown.

Another method is to use a mixture of natural rubber and butyl rubber in order to improve the adhesiveness of the tube rubber, but in this case, the adhesiveness of the rubber is improved, but the air permeability, which is inherent to the tube, decreases rapidly. There was a problem.

Therefore, the present invention is configured to solve the above problems, while improving the adhesiveness of the tube rubber while maintaining the air permeability, which is the required material properties of the tube rubber to improve the adhesion of the tube joint (joint) portion of the tube during manufacturing It is an object of the present invention to provide a tube rubber composition for tires which can prevent defects and prevent tube accidents generated during use by actually mounting on a tire.

The present invention to achieve the above object,

In the automotive tube rubber composition comprising butyl rubber as the raw material rubber and composed of carbon black, zinc oxide, stearic acid, process oil, accelerator, and vulcanizing agent,

The raw material rubber can be achieved by providing a tube rubber composition for a tire, characterized in that 10 to 30 parts by weight of epoxidized natural rubber is blended with respect to 70 to 90 parts by weight of butyl rubber.

Hereinafter, the tube rubber composition for tires of the present invention will be described in more detail.

In the present invention, the tube rubber composition is characterized in that it has an effect of improving the adhesive strength of the twisted portion of the tube rubber, which is prepared by blending butyl rubber as a raw material rubber in a certain ratio.

The epoxidized natural rubber as described above can not only increase the adhesion of the tube rubber produced due to the properties of the epoxy group, but also reduce the air permeability, which is the most important physical property of the tube.

Such epoxidized natural rubber is effective to blend 10 to 30 parts by weight based on 100 parts by weight of the raw material rubber containing butyl rubber, which is when the epoxidized natural rubber is added to less than 10 parts by weight Since the improvement effect is insignificant, it is difficult to have a predetermined effect disclosed in the present invention, and on the contrary, when 30 parts by weight is added, the amount of butyl rubber is relatively decreased, so the air permeability, which is the most important property of the tube rubber, is sharply decreased. It's hard to function properly.

Tube rubber manufactured by combining the above epoxidized natural rubber with butyl rubber as natural rubber improves the adhesiveness of the tube rubber while maintaining the air permeability, which is the most important material property, and adheres to the tube joint. It is possible to reduce the defects during the manufacture of the tube and to prevent the tube accidents that occur when used in the actual tire to be used in advance.

Although the present invention will be described in more detail with reference to the following examples, the following examples are merely illustrative of the present invention, and the present invention is not limited by the following examples.

Comparative Example

As raw material rubber, 100g of butyl rubber, 70g of carbon black, 4g of zinc oxide, 1g of stearic acid, 20g of process oil were mixed and discharged at 160 ° C. After leaving sufficiently, 2g of sulfur and 2g of accelerator were added and released at 110 ° C. Tire rubber for tubes was used as a comparative example.

<Example 1>

Prepared in the same manner as in the comparative example, but the tube rubber for the tire prepared by adding the pressure-sensitive adhesive 5g to the raw material rubber was set to Example 1.

<Example 2>

A tire tube rubber prepared in the same manner as in Comparative Example, but prepared by mixing 80 g of butyl rubber and 20 g of natural rubber as a raw material rubber, was used as Example 2.

<Example 3>

A tire tube rubber prepared in the same manner as in Comparative Example except that 95 g of butyl rubber and 5 g of epoxidized natural rubber was used as a raw material rubber was used as Example 3.

<Example 4>

A tire tube rubber prepared in the same manner as in Comparative Example, but using 80 g of butyl rubber and 20 g of epoxidized natural rubber as a raw material rubber, was used as Example 4.

Example 5

A tire tube rubber prepared in the same manner as in Comparative Example except that 60 g of butyl rubber and 40 g of epoxidized natural rubber was used as a raw material rubber, was used as Example 5.

Experimental Example 1

For the tire tube rubbers manufactured in the same manner as in Comparative Examples and Examples 1 to 3, the adhesive strength and air permeability measured in Comparative Example were 100, respectively, and the values for each Example were compared with those of Comparative Example. Measured as shown in Table 1 below. (The internal air permeability was measured by 0.3m / m thick specimens, and the upper and lower pressure difference was given to measure the degree of air movement from the large pressure part to the low pressure part.)

Comparative example Example 1 Example 2 Example 3 Example 4 Example 5 Cuint Adhesion 100 103 110 103 130 134 Air permeability 100 99 70 99 96 82

As can be seen through Table 1, when looking at the respective examples based on the comparative example, in the case of Example 1 to which the pressure-sensitive adhesive is added it can be seen that the air permeability does not change significantly, but the adhesive strength is not significantly improved. In the case of Example 2 using the mixture of butyl rubber and natural rubber as the raw material rubber, the adhesive strength was relatively improved, but air permeability was significantly decreased.

In addition, looking at the case of Examples 3 to 5 prepared by mixing butyl rubber and epoxidized rubber as the raw material rubber, the Example 3 shows that the adhesive strength was not significantly improved because of the small amount of epoxidized natural rubber. On the contrary, in the case of Example 5, the amount of epoxidized natural rubber is added so much that the air permeability is significantly lowered. On the other hand, in the case of Example 4 it can be seen that the air permeability does not change significantly while the adhesive strength is significantly improved.

As described above, the tube rubber composition for tires of the present invention improves the adhesiveness of the tube rubber while maintaining the air permeability, which is the main property of the tube rubber, which is produced by mixing the butyl rubber with the epoxidized natural rubber at a predetermined mixing ratio as a raw material rubber. By improving the adhesion of the tube joint (joint) part is to reduce the defects during the manufacturing of the tube and to bring the effect that can be prevented in advance the tube accidents generated when used in the actual tire.

Claims (1)

In the automotive tube rubber composition comprising butyl rubber as the raw material rubber and composed of carbon black, zinc oxide, stearic acid, process oil, accelerator, and vulcanizing agent, Tube rubber composition for tires, characterized in that the raw material rubber is 10 to 30 parts by weight of epoxidized natural rubber with respect to 70 to 90 parts by weight of butyl rubber.