JPH08302029A - Production of rubber composition for tire - Google Patents

Abstract

PURPOSE: To produce a rubber composition for tires, having low rolling resistance and high abrasion resistance of the tires by mixing a diene-based synthetic rubber with a natural rubber, carbon black and other components according to a specific method. CONSTITUTION: (A) A diene-based synthetic rubber (e.g. a styrene-butadiene copolymer or a polybutadiene rubber) is initially mixed with (B) carbon black in an amount of 50-100wt.% based on the total amount to provide a masterbatch, which is subsequently mixed with (C) a natural rubber and the remainder of the carbon black and (D) other components. When plural kinds are used as the carbon black, e.g. carbon black capable of reducing the rolling resistance of tires and carbon black capable of increasing the abrasion resistance thereof are used. For example, an antioxidant or zinc white can be used as the component (D).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a rubber composition for a tire.

[0002]

2. Description of the Related Art Rubber compositions for treads of fuel-efficient tires for passenger cars include styrene-butadiene rubber (SB
R), natural rubber, and components such as carbon black. By the way, conventionally, when manufacturing the said rubber composition, styrene butadiene rubber and natural rubber were simultaneously mixed with carbon black.

[0003]

In the above conventional manufacturing method, it is difficult to uniformly disperse carbon black in rubber,
This increases the rolling resistance of the tire,
There has been a problem that wear resistance is deteriorated. An object of the present invention is to provide a method for producing a rubber composition for tires which can solve the above problems.

[0004]

In order to achieve the above object, the method for producing a rubber composition for a tire according to the present invention is characterized in that a diene synthetic rubber and a natural rubber (NR) are used.
And a method for producing a rubber composition for tires containing components such as carbon black, a diene-based synthetic rubber is mixed with 50 to 100% by weight of the total amount of carbon black to produce a masterbatch. , (1)
Natural rubber and (2) the rest of carbon black,
(3) The point is to mix other components. The carbon black may be composed of plural kinds of carbon black. In addition, the carbon black may be composed of (A) carbon black that reduces the rolling resistance of the tire and (B) carbon black that increases the wear resistance of the tire.

The present invention will be described in detail below. The present invention is generally applied to a method for producing a rubber composition for a tread of a tire, but may be applied to a method for producing a rubber composition of another portion such as a rubber composition for a sidewall in a tire. As the diene-based synthetic rubber, styrene-butadiene rubber (SBR, styrene-butadiene copolymer), synthetic polyisoprene rubber (IR), polybutadiene rubber (BR)
Etc. These diene-based synthetic rubbers are
Alternatively, they are mixed and used.

Any kind of carbon black may be used. As the carbon black, usually, a single type of carbon black is used, but if necessary, a plurality of types of carbon black having different average particle sizes and different properties are used. When using a plurality of types of carbon black, for example, carbon black having a low rolling resistance of the tire and carbon black having a high abrasion resistance are used. In addition to the rubber component and carbon black, the rubber composition for a tire contains various additives such as an antioxidant and zinc white, if necessary.

When producing a rubber composition for tires,
50 to 1 of the total amount of carbon black in diene synthetic rubber
A masterbatch (intermediate rubber compound, intermediate product, intermediate) is prepared by mixing 00% by weight, and natural rubber, the rest of carbon black, and other components are mixed into the masterbatch. As a result, the carbon black is uniformly dispersed in the rubber, which reduces the rolling resistance of the tire and increases the wear resistance.

[0008]

The present invention will be further described below with reference to examples and comparative examples, but the present invention is not limited to the examples. All the following "parts" represent "parts by weight". Example 1 A rubber composition for tires was produced from the components shown in Table 1 below. In this production, a solution-polymerized styrene-butadiene rubber was mixed with 50% by weight of the total amount of carbon black N339 to produce a masterbatch. Were mixed to produce a rubber composition for a tire.

[0009]

[Table 1] Solution-polymerized styrene-butadiene rubber 60 parts Natural rubber 40 parts Carbon black N339 50 parts Zinc white 3 parts Stearic acid 2 parts Antioxidant 6C 1.5 parts Paraffin wax 2 parts Aroma oil 10 parts Vulcanization accelerator CZ 1 part sulfur 1.7 parts

[Examples 2 and 3] In the same manner as in Example 1,
A rubber composition for tires was produced. The difference from Example 1 is only the carbon distribution rate. In Example 2, the carbon distribution rate is 75%, and in Example 3, the carbon distribution rate is 1.
It is 00%. The carbon distribution ratio indicates the ratio (% by weight) of carbon black to be mixed with styrene-butadiene rubber in the total amount of carbon black during the production of the masterbatch.

Comparative Examples 1 to 3 In the same manner as in Example 1,
A rubber composition for tires was produced. The carbon distribution ratio is 25% in Comparative Example 1 and 0% in Comparative Examples 2 and 3. The carbon distribution ratio of 0% means that styrene-butadiene rubber and natural rubber were simultaneously mixed with carbon black. In Comparative Example 3, as carbon black,
N351 was used.

[Test Example 1] The rubber compositions for tires obtained in Examples and Comparative Examples were kneaded with a Banbury mixer and rolls, and each unvulcanized rubber was heated at 150 ° C for 3 hours.
Press vulcanization was performed for 0 minutes to prepare samples of each example and each comparative example. Next, for each sample, the internal loss (t
an δ 0 ℃), internal loss at 50 ℃ (tan δ 50
Lambourn wear was measured. The measurement results are shown in Table 2. The internal loss at 0 ° C is an index of wet performance.
The larger the size, the better the performance. The internal loss at 50 ° C. is an index of rolling resistance, and the smaller the internal loss, the better the performance. Lambourn wear is an index of wear resistance, and the larger it is, the better the performance is. In addition, in Table 2, the measurement result of Comparative Example 2 is set to 100 and is displayed as an index.

[0013]

[Table 2]

As shown in Table 2, in Examples 1 to 3, rolling resistance was low and abrasion resistance was high, and Comparative Examples 1 to 3
Is better than

[Examples 4 to 6] In the same manner as in Example 1,
A rubber composition for tires was produced. In addition, as carbon black, 25 parts of N351 for reducing rolling resistance,
Twenty-five parts of N339, which has high abrasion resistance, was used.

Comparative Examples 4 to 7 Rubber compositions for tires were produced in the same manner as in Examples 4 to 6. In Comparative Examples 4 and 5, the same carbon blacks as in Examples 4 to 6 were used, and in Comparative Example 3, only N351 was used.
In Comparative Example 4, only N339 was used. The carbon distribution ratio was set to 25% in Comparative Example 4 and 0% in Comparative Examples 5 to 7.

[Test Example 2] The same measurement as in Test Example 1 was performed. Table 3 shows the measurement results. In addition, in Table 3, the measurement result of the comparative example 5 is set to 100 and is displayed as an index.

[0018]

[Table 3]

Looking at Table 3, carbon black N351
Although the rolling resistance can be reduced in Comparative Example 6 in which only No. 1 is used, there is a problem in wear resistance. Further, in Comparative Example 7 using only carbon black N339, abrasion resistance can be increased, but rolling resistance cannot be reduced. On the other hand, in Examples 4 to 6, the rolling resistance can be reduced and the abrasion resistance can be increased.

[0020]

As described in detail above, according to the present invention,
The rolling resistance of the tire can be reduced and the wear resistance can be increased.

Claims (3)

[Claims] 1. A method for producing a rubber composition for a tire, which comprises components such as diene synthetic rubber, natural rubber and carbon black, wherein the diene synthetic rubber contains 50 to 1 of the total amount of carbon black.
A masterbatch was prepared by mixing 00% by weight, and (1) natural rubber and (2) were added to the masterbatch.
A method for producing a rubber composition for a tire, which comprises mixing (3) other components with the balance of carbon black. 2. The method for producing a tire rubber composition according to claim 1, wherein the carbon black comprises a plurality of types of carbon black. 3. A carbon black comprising: (A) carbon black for reducing rolling resistance of a tire; and (B)
The method for producing a rubber composition for a tire according to claim 1 or 2, which is composed of carbon black which has high wear resistance of the tire.