KR100656552B1 - rubber composition improved dispersion for tire - Google Patents

Abstract

The present invention relates to a rubber composition for tires with improved dispersibility. More specifically, by adding a dispersant having a low zinc content to the rubber composition, viscosity and physical properties are improved by improving compatibility and dispersibility of carbon black and raw material rubber. The present invention relates to a rubber composition for tires that is environmentally friendly and has improved dispersibility.

In the rubber composition for tires using carbon black as a reinforcing agent, an object of the present invention is to provide a rubber composition for tires that can improve the dispersibility of carbon black in a rubber compound by using a metal fatty acid salt known as a silica dispersant. It is done.

In the rubber composition for tires using carbon black as a reinforcing agent, it is possible to provide a rubber composition for tires that is environmentally friendly and has improved dispersibility by using a metal fatty acid salt having a low zinc content as a dispersant.

The present invention provides a zinc-potassium soap having a zinc content of 0.1 to 1% with respect to 100 phr of raw rubber in order to improve the compatibility and dispersibility of the carbon black with the raw rubber. (zinc-potassium soap) The rubber composition for tires containing 1-10 phr is shown.

Description

Rubber composition improved dispersion for tires

The present invention relates to a rubber composition for tires with improved dispersibility. More specifically, by adding a dispersant having a low zinc content to the rubber composition, viscosity and physical properties are improved by improving compatibility and dispersibility of carbon black and raw material rubber. The present invention relates to a rubber composition for tires that is environmentally friendly and has improved dispersibility.

When silica is used as a reinforcing agent in rubber compositions for conventional tires, its high polarity and hydrophilic group make it poorly compatible with non-polar rubber compared to carbon black, weak interaction with rubber, and strong cohesion between silica, which is very disadvantageous in terms of processing. Do.

To solve this problem, silica surface was treated with silane coupling agent or silane coupling agent was used in rubber composition to improve compatibility and dispersibility of silica and raw material rubber. Reinforcement tends to be somewhat inferior, such as falling, and silica dispersing aid is added in addition to a silane coupling agent to improve the dispersibility of silica.

The dispersing aid is a compound mainly composed of metal fatty acid salts. The metal ion is mainly zinc or potassium, and is an amphiphilic substance having both hydrophilic groups and hydrophobic groups by fatty acids.

The metal ions of the dispersion aid react with silanol groups on the silica surface to reduce surface energy between molecules against silica agglomerating, which is strongly bound to each other by hydrogen bonding or dipole bonding. Induces de-agglomerating.

Fatty acid of the dispersing aid is excellent in the rubber chain and usability and plays a role of dilute rubber chains (dilute).

However, zinc, which is used as a metal ion in dispersing aids, has recently been regulated as a heavy metal that may cause toxicity to the ecosystem from an environmental point of view, thus reducing the zinc content in rubber compositions.

In addition, when carbon black is used as a reinforcing agent in rubber compositions, compatibilizers such as oils or resins are mainly used. However, when metal fatty acid salts known as silica dispersants are used, the dispersibility of carbon black is improved and the compression process is effective. Indicates.

The present invention provides a rubber composition for a tire in which a rubber composition using carbon black as a reinforcing agent can improve the dispersibility of the carbon black in the rubber compound by using a metal fatty acid salt known as a silica dispersant. The purpose.

Another object of the present invention is to provide a tire comprising a rubber having a low zinc content as a dispersing agent for carbon black and a rubber including rubber having improved viscosity and physical properties by improving compatibility and dispersibility of carbon black with raw rubber. It is done.

On the other hand, the present invention in the rubber composition for tires using carbon black as a reinforcing agent, by using a metal fatty acid salt with a low zinc content as a dispersant can provide an environmentally friendly, rubber composition for tires with improved dispersibility.

In order to achieve the above-mentioned object, the present invention provides a rubber composition containing carbon black as a reinforcing agent, and has a zinc content of 0.1 to 100 phr as a dispersant to improve the compatibility and dispersibility of the carbon black and the raw material rubber. The rubber composition for tires containing 1-10 phr of zinc-potassium soap is shown.

In the present invention, the raw material rubber can be used as long as it can be used as the raw material rubber of the conventional rubber composition for tires.

In the present invention, as an example of such raw rubber, natural rubber or synthetic rubber may be used alone, or mixed rubber in which natural rubber and synthetic rubber are mixed in a weight ratio of 1: 9 to 9: 1.

The synthetic rubber may be any one or more selected from styrene butadiene rubber, butadiene rubber, styrene butadiene rubber containing isoprene, styrene butadiene rubber including nitrile, neoprene rubber, chloro butyl rubber and bromo butyl rubber.

Meanwhile, in the present invention, the raw material rubber may use a mixed rubber of two or more synthetic rubbers. At this time, the two types of synthetic rubber can be used as a raw material rubber mixed rubber in a weight ratio of 1: 9 to 9: 1.

In the present invention, the dispersant used to improve the dispersibility of carbon black with raw rubber and other rubber compound is zinc-potassium soap dispersing agent having a zinc content of 0.1 to 1% based on 100 phr of raw rubber. 1 to 10 phr can be used.

In the present invention, the zinc-potassium soap, which is a dispersant, preferably uses a zinc content of 1% or less, more preferably 0.1 to 1% in order to provide an environmentally friendly dispersant.

In the present invention, when the dispersing agent is less than 1 phr of the raw material rubber, it is difficult to obtain a rubber having improved viscosity and physical properties by improving the dispersibility of carbon black. There is concern.

Therefore, the zinc-potassium soap dispersant having a zinc content of less than 1% is preferably used in an amount of 1 to 10 phr based on 100 phr of raw rubber.

In the present invention, carbon black may be used as long as it is used as a reinforcing agent in a conventional rubber composition for tires.

As an example of the carbon black in the present invention, carbon black having a characteristic of 80 to 150 mg / g of iodine adsorption value and 70 to 125 mg / 100 g of DBP adsorption value may be used at 40 to 60 phr with respect to 100 phr of raw rubber.

According to the present invention, various additives such as reinforcing agents, activators, anti-aging agents, process oils, vulcanizing agents, and vulcanization accelerators, which are used in conventional rubber compositions for tires, in addition to the above-mentioned raw rubbers and carbon black, may be appropriately selected. Can be used as However, these are general components used in a rubber composition for a tire and are not essential components of the present invention.

On the other hand, the present invention includes a tire containing a rubber made of the rubber composition for the tire. In this case, the tire includes any one selected from tires for automobiles, tires for trucks, and tires for buses.

Hereinafter, the present invention will be described by the following comparative examples, examples and test examples. However, these are not limited to the scope of the present invention by these as an embodiment of the present invention.

<Example 1>

As shown in Table 1 below, natural rubber is used as the raw material rubber, and 50 phr of carbon black (N103) is used for 100 phr of raw rubber, 3 phr of silica dispersant with low zinc content, zinc oxide 4 phr, stearic acid 3 phr, aromatic oil 2 phr, wax 1.0 phr, and aging. 3.5 phr of the inhibitor (2,2,4-trimethyl-1,2-dihydroquinoline, RD) was placed in a Banbury mixer, mixed and released at 160 ° C. for 15 minutes.

Then, 2.0 phr of sulfur and 1.0 phr of vulcanization accelerator (N-cyclohexyl-2-benzothiazolsulfen amide, CZ) were placed in a Banbury mixer containing the rubber compound, mixed and vulcanized at 145 ° C. for 30 minutes to prepare a rubber.

<Example 2>

A rubber was manufactured in the same manner as in Example 1, except that 5 phr of a silica dispersant having a low zinc content was used.

<Example 3>

A rubber was manufactured in the same manner as in Example 1, except that 10 phr of a silica dispersant having a low zinc content was used.

Comparative Example

A rubber was manufactured in the same manner as in Example 1, except that 3 phr of a silica dispersant, which was a conventionally used agent, was used instead of a silica dispersant having a low zinc content.

TABLE 1 COMPARATIVE EXAMPLES AND EXAMPLES Composition Components of Rubber (Unit: phr)

Item Comparative example Example 1 Example 2 Example 3 Raw material rubber 100 100 100 100 Carbon black (N103) 50 50 50 50 Dispersant (1) - 3 5 10 Compatibilizer (2) 3 - - - Aromatic oils 2 2 2 2 Anti-aging 3.5 3.5 3.5 3.5 Wax 1.0 1.0 1.0 1.0 Zinc Oxide (ZnO) 4 4 4 4 Stearic acid 3 3 3 3 sulfur 2.0 2.0 2.0 2.0 Vulcanization accelerator 1.0 1.0 1.0 1.0

(1) dispersants zinc-potassium soaps with a zinc content of 0.5%

(2) The compatibilizer is zinc-potassium soap with a zinc content of 8.3% (Struktol 40MS).

<Test Example>

Physical properties such as rheometer, Mooney test, tensile test, dynamic test, exothermic test, and abrasion test of the rubber prepared in Comparative Examples and Examples were measured by ASTM-related regulations, and the results are shown in Table 1 below. .

TABLE 2 Physical property results of rubbers

Item Comparative example Example 1 Example 2 Example 3 Rheometer T40 15.6 15.7 15.5 15.8 T90 23.2 23.3 24.3 25.4 Torque 41.6 42.0 41.8 43.2 Mooney test Viscosity 68 68 65 62 Scorch time (minutes) 31.0 29.5 29.0 28.6 Tensile test Hardness 67 67 67 68 300% modulus 139 135 137 142 The tensile strength 293 283 295 300 Elongation 515 517 529 516 Dynamic test Tanδ0 ℃ 0.185 0.186 0.189 0.197 Tanδ60 ℃ 0.118 0.109 0.094 0.089 Fever test ΔTemp. (℃) 22.5 22.5 22.5 22.5 Compression set (%) 97 97 97 97 Wear test DIN (g) 0.135 0.130 0.127 0.125 PICO (mg) 24.5 23.7 23.0 20.5

As shown in Table 2 of the above test example, the rubber composition made of the rubber composition according to the present invention is excellent in properties for the tensile test and the dynamic test, and thus the carbon black is improved in the present invention by the dispersing agent. Can be.

As described above, although described with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and modified within the scope of the present invention without departing from the spirit and scope of the present invention described in the claims below. It will be appreciated that it can be changed.

Claims (2)

In a rubber composition using carbon black as a reinforcing agent, In order to improve the compatibility and dispersibility of carbon black and raw material rubber, zinc phosphate soap 1 to 10 phr having a zinc content of 0.1 to 1% is included as a dispersant based on 100 phr of raw material rubber. A rubber composition comprising 150 mg / g, DBP adsorption of 70 to 125 mg / 100 g and 40 to 60 phr. delete