KR100563139B1 - Rubber composition for tire - Google Patents

Abstract

The present invention relates to a tire rubber composition, by using oil-coated zinc oxide instead of zinc oxide added as an activator in the tire rubber composition to improve the dispersion of zinc oxide in the rubber composition and ultimately the physical property deviations between the rubber compositions. B, there is provided no rubber scorch, and even when two or more rubbers are bonded, there is provided a tire rubber composition that does not have a drop in adhesion or deterioration in quality and defects in contact surfaces.

Description

Tire composition for tire

The present invention relates to a tire rubber composition, and more particularly, to a tire rubber composition in which zinc oxide used in the rubber industry is oil-coated to improve the dispersibility of zinc oxide in rubber.

In general, the role of zinc oxide used in the rubber industry is to activate organic promoters used when the rubber and sulfur are vulcanized.

In the rubber industry, the amount of zinc oxide used is adjusted according to the required rubber properties.

Zinc oxide is electrostatic and agglomerates with each other, resulting in a decrease in dispersion in rubber when used excessively. When the dispersion degree of zinc oxide decreases, physical property deviations occur between the rubber compositions, and locally exist in excess, causing scorching of the rubber.

In addition, when zinc oxide is exposed on the rubber surface due to a decrease in dispersion degree, it is necessary to bond two or more rubbers during processing, which may cause deterioration of adhesion and deterioration of quality such as local over-curing and defects. Tao is a very important quality control item.

In order to improve the dispersibility of zinc oxide in the rubber composition, conventionally, a method of granulating a powder type zinc oxide has been used, but there is a problem in that the granule is broken and becomes a powder during transportation and storage, thereby decreasing the dispersibility.

Therefore, the inventors of the present invention have been searching for a method of improving the dispersion of zinc oxide in the tire rubber composition, and as a result of using oil coated zinc oxide, the oil coated on the surface prevents zinc oxide from agglomerating. The present invention has been made to improve the degree of dispersion in the rubber composition.

Accordingly, it is an object of the present invention to provide a tire rubber composition with improved dispersion of zinc oxide.

The tire rubber composition of the present invention for achieving the above object is to include zinc oxide as an active agent, wherein zinc oxide is characterized in that the surface is zinc oxide coated with oil.

The present invention relates to a tire rubber composition comprising zinc oxide with improved dispersibility.

The zinc oxide having improved dispersibility is zinc oxide coated with an oil. The oil is not particularly limited, but is preferably a process oil (aromatic) used in the tire rubber composition, and the coating amount is zinc oxide. It is preferable that it is 2-10 weight% with respect to.

The method of oil coating on zinc oxide is not particularly limited. For example, zinc oxide may be mixed in a container and sprayed with oil from above.

The content of such oil-coated zinc oxide is generally 1.0 to 20 parts by weight based on 100 parts by weight of the raw material rubber, in accordance with the content of zinc oxide in the tire rubber composition. If the content of oil-coated zinc oxide is less than 1 part by weight based on 100 parts by weight of the raw material rubber, if it does not function properly as an activator of the accelerator during vulcanization, and if it is more than 20 parts by weight, the dispersion degree and surface precipitation phenomenon due to supersaturation in rubber The back will rise.

On the other hand, in the tire rubber composition of the present invention, natural rubber or synthetic rubber may be used as the raw rubber, and yellow ribbed smoke sheets or technical standard rubbers according to international standard samples, preferably diene-based natural rubber, may be used. .

In addition, conventional blending agents added in the tire rubber composition include, but are not limited to, stearic acid, process oil, sulfur, and accelerators.

Hereinafter, the present invention will be described in more detail with reference to Examples. The present invention is not limited by the Examples.

Comparative Example 1

As shown in Table 1 below, 100 parts by weight of the dark brown to yellow ribbed smoke sheet, 45 parts by weight of carbon black (HAF), 5 parts by weight of zinc oxide, 3 parts by weight of stearic acid, aromatic by diene-based natural rubber international standard sample Rubber parts were prepared by mixing 2 parts by weight of oil, 2.2 parts by weight of sulfur and 1 part by weight of accelerator NS in a Banbury mixer.

Comparative Example 2

A specimen was prepared using the composition and method of Comparative Example 1, except that 10 parts by weight of zinc oxide was used as shown in Table 1 below.

Comparative Example 3

A specimen was prepared using the composition and method of Comparative Example 1, except that 15 parts by weight of zinc oxide was used as shown in Table 1 below.

Comparative Example 4

A specimen was prepared using the composition and method of Comparative Example 1, except that 20 parts by weight of zinc oxide was used as shown in Table 1 below.

Example 1

As shown in Table 1 below, 100 parts by weight of a dark brown to yellow ribbed smoke sheet, 45 parts by weight of carbon black (HAF), 5 parts by weight of oil-coated zinc oxide, and 3 parts by weight of stearic acid according to the international standard specimen of the diene-based natural rubber 2 parts by weight of aromatic oil, 2.2 parts by weight of sulfur and 1 part by weight of accelerator NS were mixed in a Banbury mixer to prepare a rubber specimen.

Example 2

A specimen was prepared using the composition and method of Example 1, except that 10 parts by weight of oil-coated zinc oxide was used as shown in Table 1 below.

Example 3

A specimen was prepared using the composition and method of Example 1, except that 15 parts by weight of oil-coated zinc oxide was used as in Table 1 below.

Example 4

A specimen was prepared using the composition and method of Example 1, except that 20 parts by weight of oil-coated zinc oxide was used as shown in Table 1 below.

(Unit: parts by weight) Item Comparative example Example One 2 3 4 One 2 3 4 Raw material rubber 100 100 100 100 100 100 100 100 Carbon black 45 45 45 45 45 45 45 45 Zinc oxide 5 10 15 20 - - - - Oil coating zinc oxide - - - - 5 10 15 20 Stearic acid 3 3 3 3 3 3 3 3 A # 2 Oil 2 2 2 2 2 2 2 2 brimstone 2.2 2.2 2.2 2.2 2.2 2.2 2.2 2.2 NS One One One One One One One One Oil Coated Zinc Oxide: Zinc oxide coated with aromatic oil 2 to 10% by weight relative to zinc oxide

<Test Example>

Rmax (180 ° C.) was measured 20 times for each part of the rubber specimens prepared by the rubber compositions and methods of Comparative Examples and Examples. The standard deviation of the Tmax values of each rubber specimen was measured, and the dispersion degree of zinc oxide is shown in Table 2 below. The smaller the standard deviation value of the Tmax value, the better the zinc oxide dispersion.

Item Comparative example Example One 2 3 4 One 2 3 4 Tmax standard deviation (20 measurements) 0.43 0.65 1.24 1.97 0.21 0.27 0.32 0.38 Tmin standard deviation (20 measurements) 0.32 0.35 0.36 0.40 0.17 0.22 0.25 0.28 Zinc Oxide Dispersion Good disadvantage disadvantage Very disadvantaged Very good Very good Good Good

From the results in Table 2, it can be seen that in the case of the tire rubber composition to which the oil-coated zinc oxide is added, the dispersion degree of zinc oxide is improved compared with the zinc oxide used conventionally.

As described in detail above, the rubber composition using zinc oxide having an oil-coated surface according to the present invention improves the dispersion degree of zinc oxide in the rubber composition, and ultimately there is no property deviation or rubber scorch generation between the rubber compositions. Even when two or more rubbers are bonded, there is no deterioration in adhesion or deterioration in quality and defects on the contact surface.

Claims (4)

In a tire rubber composition comprising zinc oxide as a raw material rubber and an activator, The zinc oxide is a tire rubber composition, characterized in that the surface is zinc oxide coated with oil. (Correction) The tire rubber composition according to claim 1, wherein the zinc oxide coated on the surface is contained in an amount of 1 to 20 parts by weight based on 100 parts by weight of the raw material rubber. 3. The tire rubber composition according to claim 1 or 2, wherein the zinc oxide coated on the surface is zinc oxide coated with the process oil so as to be 2 to 10% by weight relative to zinc oxide. The tire rubber composition according to claim 1, wherein the raw material rubber is a single rubber or a mixed rubber thereof selected from natural rubber and synthetic rubber.