KR20000031879A - Rubber composition for color sidewall - Google Patents

Abstract

PURPOSE: A rubber composition for color side wall is provided which satisfies mechanical properties required to side wall part and exhibits various colors compared with existing white side wall rubber composition by a method characterized by adding color pigments to existing white rubber. CONSTITUTION: The rubber composition for color side wall comprises, with respect to 100 weight part of rubber component consisting of 20 - 70 weight part of natural rubber, 20 - 60 weight part of chlorobutyl rubber and 10 - 40 weight part of EPDM rubber, 0 - 40 weight part of clay, 0 - 40 weight part of bony coal, 10 - 40 weight part of titanium dioxide, and 2 - 5 weight part of at least one pigment selected from the group consisting of a monoazo, a diazo, a phthalocyanine and a quinacrydine pigment.

Description

Rubber Composition for Collar Sidewalls

The present invention relates to a rubber composition for a color sidewall of a tire, and more particularly, to a rubber composition for a color sidewall made by adding color pigments showing various colors to a conventional white rubber.

In general, the rubber for the sidewall of the tire is required to have better fatigue resistance, crack growth resistance and weather resistance than other rubber parts, and also have an excellent appearance that may affect the consumer's purchase conditions. In particular, as vehicles of various colors and designs are recently released, color tires are required.

Conventionally, in order to improve the appearance of tires, a knurling method, a method of decorating using colorful fonts, and a method of decorating fonts with white rubber have been used. However, until now, the rubber for sidewalls has not been diverse, and only two colors, black or white, have been used, which do not satisfy the wider needs of consumers.

Accordingly, the present invention can exhibit a variety of colors by adding a color pigment to the conventionally used white rubber in order to improve the appearance of such a simple and limited side wall portion, the rubber composition for the color side wall satisfying the required performance that the side wall portion The purpose is to provide.

The present invention is 20 to 70 parts by weight of natural rubber, 20 to 60 parts by weight of chlorobutyl rubber, 0 to 40 parts by weight of clay, 0 to 40 parts by weight of hard coal, It is to provide a rubber composition for color sidewall consisting of 10 to 40 parts by weight of titanium dioxide and at least 2 to 5 parts by weight of at least one pigment among monoazo, diazo, phthalocyanine and queen acridine pigments.

Hereinafter, the present invention will be described in more detail.

In the rubber composition of the present invention, the basic rubber component is made of natural rubber, chlorobutyl and EPDM rubber, and includes carbon black, titanium dioxide, clay and hard coal as reinforcing materials. These stiffeners affect the color of the tires, mainly carbon black, black titanium, clay and hard coal white.

In the present invention, at least one of monoazo, diazo, phthalocyanine and quinacridin pigments may be selected and used as the pigment.

Generally, pigments can be broadly divided into inorganic and organic pigments. Inorganic metal oxides are excellent in heat resistance and light resistance, but in the case of a single metal oxide, the color range is narrow and inferior in sharpness, and organic pigments have a basic skeleton in chemical structure. Substituents are introduced to improve color change and various properties. Of these, the pigments used in the present invention are all organic pigments as described above.

In addition, the pigment is composed of a chromophore and a chromophore, and depending on the chromophore, for example, it can be classified into several types such as nitro, azo, acridine, and phthalocyanine.

More than half of the organic pigments belong to the azo system, which is divided into monoazo, diazo, triazo and tetrakizo, depending on the number of azo groups, which are basically produced by diazonation and coupling. The diazos are among the insolubles of the azos.

Among such pigments, the pigments usable in the present invention are pigments of a component without deteriorating weather resistance and other various properties. They use fine amounts, but in order to improve their dispersibility, the total mixing time is increased by 35 seconds to achieve excellent color and at the same time maintain the physical properties of the white rubber.

Among the pigments usable in the present invention are red 185, which is monoazo, and red 149, which is perylene, quinacrine, and yellow 83, which is diazo, and yellow, which is phthalocyanine. There is Green 7.

It is preferable to use 2-5 weight part of pigments with respect to 100 weight part of said rubber components. When the pigment is used in less than 2 parts by weight, the physical properties of the rubber exhibit the same properties as those of the white sidewall rubber composition, but the color is not good for appearance, and when used in excess of 5 parts by weight, the dispersion of the pigment is lowered. Ozone property and crack growth resistance fall.

Hereinafter, the present invention will be described in more detail as examples.

Example 1

Natural rubber, chlorobutyl rubber, EPDM rubber, hard coal (CaCO ₃ ), titanium dioxide, yellow 83 and the usual additives as a pigment was mixed in a composition ratio of the following Table 1 and vulcanized to prepare a yellow rubber specimen.

Example 2

A green rubber specimen was prepared in the same manner as in Example 1 except that Green 7 was used as the pigment.

Example 3

A red rubber specimen was prepared in the same manner as in Example 1 except that Red 185 was used as the pigment.

Comparative example

A white rubber specimen was prepared in the same manner as in Example 1 except that no pigment was added.

Table 1

ingredient Example 1 Example 2 Example 3 Comparative example Natural rubber 55 55 55 55 Chlorobutyl 25 25 25 25 EPDM Rubber 20 20 20 20 Clay 30 30 30 30 wonderment 25 25 25 25 TiO ₂ 25 25 25 25 Pigment 4.3 4.3 3.0 -

Test Example

The rubber specimens of Examples 1 to 3 and Comparative Examples were measured in the following physical properties, and are shown in Table 2 below.

ML 1 + 4 and t5

The processability of the unvulcanized rubber was evaluated at a similar temperature to that during processing using a patterned viscometer, that is, at 125 ° C. The unvulcanized rubber was placed in an enclosed space and the viscosity after a certain time while rotating the rotor in one direction (ML 1 + 4) ) And Scorch time (t5). If the viscosity is too high, the processing is not easy, and if the scorch time is too short, the scorch in which a part of the unvulcanized rubber is vulcanized during processing is difficult to process.

300% M, Eb, Tb

Tensile test shows strength at a certain elongation (300% M) Physical property test to obtain elongation and strength at breakage is higher 300% M, elongation and tensile strength is more advantageous.

F-F

In the fatigue resistance test, a certain strain (100%) is repeatedly stretched to confirm the cycle in which the specimen is broken. The larger the value, the more favorable the fatigue resistance. It can also be used as a means for evaluating the degree of dispersion.

Di matia

Flexural fatigue test is to evaluate the degree of flexural cracking at the cycle or growth rate of cracking by giving the flexural fatigue to the specimen. This test can also be used as a means of assessing the degree of dispersion.

Ozone resistance

To evaluate the weather resistance in the ozone chamber, to evaluate the occurrence time and extent of cracking caused by ozone at a certain strain (20-100%). In this test, 20% strain was measured by ASTM D1149 A.

TABLE 2

Water test Example 1 Example 2 Example 3 Comparative example ML 1 + 4 / t5 35.0 / 22: 09 38.2 / 20: 43 35.7 / 20: 28 39.5 / 27: 17 300% M / Eb / Tb 38/630/136 38/620/124 39/610/120 41/610/135 F-F 9.2 19.9 24.4 13.0 De MAttia 0.19 0.23 0.19 0.15 Ozone Resistance Static (2.5 months) No crack No crack No crack No crack

As shown in Table 2, Examples 1 to 3, which are the rubber compositions of the present invention, are compared with the white sidewall rubber compositions of the comparative example, the tensile properties are not significantly reduced and are maintained at the same level, and the fatigue resistance and the bending fatigue resistance are pigments. Although slightly different depending on the overall excellent, the ozone resistance was not seen a large crack, but as a result of confirming the good order, in the order of Example 2, Example 3, Example 1.

The sidewall rubber composition of the present invention can obtain a rubber composition of various colors compared to the conventional white sidewall rubber composition by using at least one pigment among monoazo, diazo, phthalocyanine and quinacridin pigments. It is possible to obtain a collar sidewall rubber composition which maintains the same physical properties as the white sidewall rubber composition.

Claims (1)

20 to 70 parts by weight of natural rubber, 20 to 60 parts by weight of chlorobutyl rubber, 0 to 40 parts by weight of clay, 0 to 40 parts by weight of hard coal, titanium dioxide 10 To 40 parts by weight and at least one pigment 2 to 5 parts by weight of a monoazo, diazo, phthalocyanine-based and quinacridine-based pigments for a rubber sidewall rubber composition.