KR100746336B1 - Tire tread rubber composition - Google Patents

Abstract

Provided is a tire tread rubber composition which is improved in heat build-up resistance, blow out characteristics, abrasion resistance, and cut and chip characteristics. A tire tread rubber composition comprises 100 parts by weight of a rubber material; 30-50 parts by weight of the carbon black having an iodine adsorption number of 155-170 mg/g, a DBP absorption of 100-120 mL/100 g and a coloring degree of 110-130 %; 5-20 parts by weight of the precipitated silica having a BET adsorption value of 150-170 m^2/g and a DBP absorption of 180-200 mL/100 g; and 1-5 parts by weight of a silica dispersant which is a fatty acid metal compound of a fatty acid and at least one metal selected from zinc and calcium and has a softening point of 95-105 deg.C.

Description

Tire tread rubber composition

The present invention relates to a tire tread rubber composition, and more particularly, to a conventional tire tread rubber composition, including carbon black, precipitated silica, and silica dispersant, to improve heat resistance, blowout characteristics, wear resistance, and cut and chip characteristics. The present invention relates to a tire tread rubber composition.

As vehicle development and road conditions improve, vehicle running speed gradually increases, and the severity applied to tires increases gradually as vehicle performance improves.

The heat and wear resistance of the tread rubber composition is determined by the properties of the tread surface layer that moves in contact with the ground.The heat inevitably generated during high-speed driving causes a decrease in tire durability due to a drop in physical properties, abrasion resistance, and an increase in heat generation temperature. have.

Conventionally, in order to solve this problem, it is possible to improve the heat stability by using excessive amount of anti-aging agent with excellent heat resistance in natural rubber compound, mixing of raw material rubber, crosslinking agent to single or double sulfur bonding rather than multiple sulfur bonding. I'm trying to make it work.

However, these conventional methods have a problem in improving tensile strength, abrasion resistance, and heat resistance performance of rubber properties.

Various rubber compositions have been developed to improve the wear resistance of tire tread rubber compositions. For example, Korean Patent Laid-Open Publication No. 2004-0003995 discloses 2,2,4-trimethyl-1,2-dihydro having a ratio of monomers and multimers of 1: 9 to 1.5: 8.5 as a heat resistant antiaging agent based on 100 parts by weight of raw rubber. There is a description of a tire tread rubber composition for trucks and buses that phomes 1-3 parts by weight of quinoline.

In addition, Korean Patent Laid-Open Publication No. 2003-0096856 improves braking performance by using a solution-polymerized styrene-butadiene rubber in which the terminal is modified with tertiary amine in the raw material rubber, and the tertiary amine at the chain end reacts with the functional group on the surface of carbon black. There is a description of a tire tread rubber composition for truck buses that can reduce the movement of the chain ends by forming chemical bonds, thereby reducing rolling resistance due to energy loss and providing wear resistance at all times.

However, the above-mentioned prior arts, in the conventional tire tread rubber composition, include a carbon black, precipitated silica, silica dispersant, the present invention showing a tire tread rubber composition that can improve the heat resistance, blowout characteristics, wear resistance and cut and chip characteristics The invention and the technical configuration are different from each other.

The present invention, in the conventional tire tread rubber composition, including a carbon black, precipitated silica, silica dispersant for the purpose of providing a tire tread rubber composition that can improve heat resistance, blowout characteristics, wear resistance and cut and chip characteristics do.

The present invention includes a tire containing a rubber composed of the above-mentioned tire tread rubber composition.

Tire tread rubber composition of the present invention for achieving the above-mentioned object is 30 to 50 parts by weight of carbon black, 5 to 20 parts by weight of precipitated silica, silica dispersant with respect to 100 parts by weight of the raw material rubber in the conventional tire tread rubber composition It contains 1-5 weight part.

In the present invention, the raw material rubber can be used as long as it can be used as the raw material rubber in the conventional tire tread rubber composition. As one example of such raw rubber, any one or more rubber selected from natural rubber and synthetic rubber may be used as raw rubber.

Of the raw material rubber, 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 and neoprene rubber.

In order to improve the heat resistance and abrasion resistance of the tire tread rubber composition, the reinforcing filler is carbon black and silica.

In the carbon black, 155 to 170 mg / g of iodine adsorption, 100 to 120 ml / 100 g, and a coloring degree of 110 to 130% may be used to improve the heat resistance and wear resistance of the tire tread rubber composition.

In the present invention, silica may be used a highly dispersible silica. That is, synthetic hydrated silica obtained by sedimentation can be used. As an example of such silica, precipitated silica having a BET adsorption value of 150 to 170 m ² / g and a DBP adsorption of 180 to ²⁰⁰ ml / 100 g can be used.

Since silica has a strong tendency to agglomerate with each other, the composition to which silica is applied requires an additive for improving the dispersibility of silica in the composition. In the present invention, a silica dispersant is used for dispersibility of such silica.

In the present invention, the silica dispersant is a compound of any one or more metals selected from fatty acids, zinc and potassium, and more specifically, a metal is a fatty acid metal compound by addition of fatty acids, and a softening point of 95 to 105 ° C may be used.

As the fatty acid used in the silica dispersant, saturated fatty acid or unsaturated fatty acid may be used. Examples of saturated fatty acids include acetic acid, propionic acid, butyric acid, gilacetic acid, caproic acid, enanthic acid, caprylic acid, perargonic acid, caprinic acid, undecylic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, Any one or more selected from paroxylic acid, heptadecyl acid, stearic acid, nonadecanoic acid, and arachnic acid can be used. Meanwhile, as an example of the unsaturated fatty acid, any one or more selected from acrylic acid, crotonic acid, undecylenic acid, oleic acid, setleinic acid, ercaic acid, brush zinic acid, sorbic acid, linoleic acid, linolenic acid, and arachidonic acid may be used.

For example, zinc salt is added to acetic acid to zinc acetate, and potassium salt is added to draft to potassium acetate.

In the present invention, the tire tread rubber composition is applied by various compositions and contents. In order to achieve the object of the present invention, it is preferable to apply the tire tread rubber composition to the above-mentioned contents.

The present invention, in addition to the above-mentioned raw rubber, carbon black, silica, silica dispersant, various additives such as reinforcing fillers, activators, antioxidants, process oils, vulcanizing agents and vulcanization accelerators used in conventional tire tread rubber compositions as needed It can be used at a predetermined content by selecting an enemy. However, these are general components used in conventional tire tread rubber compositions, and thus are not essential components of the present invention, and thus the detailed descriptions thereof will be omitted.

On the other hand, the present invention includes a tire containing a rubber made of the tire tread rubber composition. At this time, it preferably comprises a tire containing the rubber made of the tire tread rubber composition as a tread.

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.

Comparative Example

50 parts by weight of carbon black (1), 5.4 parts by weight of silica, 4 parts by weight of process oil, 5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, and antioxidants as raw material rubbers based on 100 parts by weight of natural rubber. 2,2,4-trimethyl-1,2-dihydroquinoline, RD) 3.75 parts by weight, and 1 part by weight of wax were put in a Banbury mixer and blended at 140 ° C. for 30 minutes to obtain a rubber compound. Then, 1.5 parts by weight of sulfur and 0.8 parts by weight of a vulcanization accelerator (N-cyclohexyl-2-benzothiazolsulfen amide, CZ) were added to the rubber mixture, and vulcanized at 150 ° C. for 20 minutes to prepare a rubber specimen.

In the carbon black (1), iodine adsorption was 122mg / g, DBP adsorption was 116ml / 100g, the coloration was used 114%.

In the above silica, precipitated silica having a BET adsorption value of 155m ² / g and a DBP adsorption of 190ml / 100g was used.

Example 1

30.5 parts by weight of carbon black (2), 15 parts by weight of silica, 2 parts by weight of silica dispersant, 4 parts by weight of process oil, 5 parts by weight of zinc oxide, stearic acid 2 Part by weight, 3.75 parts by weight of anti-aging agent (RD) and 1 part by weight of wax were placed in a Banbury mixer and blended at 140 ° C. for 30 minutes to obtain a rubber compound. Then, 1.5 parts by weight of sulfur and 0.8 parts by weight of vulcanization accelerator (CZ) were added to the rubber compound, and vulcanized at 150 ° C. for 20 minutes to prepare a rubber specimen.

In the carbon black (2) was used iodine adsorption 162mg / g, DBP adsorption 111ml / 100g, the coloration 120.5%.

In the above silica, precipitated silica having a BET adsorption value of 155m ² / g and a DBP adsorption of 190ml / 100g was used.

The silica dispersant has a softening point of 100 ° C., and zinc acetate, a compound of a fatty acid and a metal salt, was used.

Example 2

A rubber specimen was prepared in the same manner as in Example 1, except that 38.5 parts by weight of carbon black (2) was used.

Example 3

A rubber specimen was prepared in the same manner as in Example 1, except that 46.5 parts by weight of carbon black (2) was used.

Table 1. COMPARATIVE EXAMPLES AND EXAMPLES Rubber Compositions

Item Comparative example Example 1 Example 2  Example 3 Natural rubber 100 100 100 100 Carbon black (1) 50 - - - Carbon black (2) - 30.5 38.5 46.5 Silica 5.4 15 15 15 Silica dispersant - 2 2 2 Process oil 4 One One One Zinc oxide 5 3.5 3.5 3.5 Stearic acid 2 2 2 2 Anti-aging 3.75 3.5 3.5 3.5 Wax One One One One brimstone 1.5 One One One Vulcanization accelerator 0.8 1.5 1.5 1.5

<Test Example>

The rubber specimens of the Comparative Examples and Examples were prepared according to ASTM-related regulations, such as fairness (Mooney viscosity (100 ° C), scorch time, vulcanization time), tensile properties before and after aging (hardness, 300% modulus, tensile strength, elongation) Physical properties such as thermal properties, blow out, rebound, wear index, and cut and chip index were measured and the results are summarized in Table 2 below.

Table 2. Comparative Examples and Examples Properties of Rubber Specimens

Item Comparative example Example 1 Example 2 Example 3 Fairness Mooney viscosity (100 ℃) 58 62 67 73.5 Scorch time (t5) 26.4 31.9 28.8 23.5 Rush time (t90) 19.9 28.6 23.5 19.6 Tensile Properties (Before Aging) Shore A 63 61 66 72 300% modulus (kg / cm ² ) 96 124 132 151 Tensile Strength (kg / cm ² ) 255 251 275 315 % Elongation 618 614 555 450 Tensile Properties (After Aging) Shore A 67 66 70 73 300% modulus (kg / cm ² ) 121 153 163 172 Tensile Strength (kg / cm ² ) 229 257 264 286 % Elongation 544 601 501 420 Heat resistance (℃) 30 21.4 25.5 36.2 Blowout (time) 4.3 8.6 11.4 20.6 rebound(%) 35.15 35.6 40.27 36.5 Wear index 100 110 124 136 Cut and Chip Index 100 110 105 118

* Heat resistance is measured by applying a certain stroke to rubber specimens using Perry Machinery's hysteresis testing machine, and the lower the value, the better the heat resistance characteristics.

* Blow-Out is a value measured using the B.F.Goodrich Blow-out Test, which means that the longer the blowout time, the better the blowout characteristic.

* The abrasion index is measured by using B.F.Goodrich wear tester, and the wear value of rubber specimen is measured when the comparative example value is 100. The higher the value, the better the wear resistance. do.

* The cut and chip index (cut and chip index) is a measure of the cut and chip of the rubber specimens using a BF Goodrich cut and chip tester (Example when the comparative value is set to 100) The cut-and-chip value is expressed as conversion, and the higher the value, the better the cut-and-chip resistance.

Aging was carried out at 105 ° C. for 5 days.

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.

In the workability and tensile properties of Table 2, the rubber sample of the present invention has a physical property equal to or higher than the comparative example of the conventional rubber sample in terms of workability and tensile properties.

On the other hand, the heat resistance, blowout characteristics, rebound, wear resistance and cut and chip properties of the physical properties of the rubber sample of the present invention was found to be superior to the rubber sample of the comparative example showing a conventional rubber composition.

Claims (3)

In the tire tread rubber composition, 30 to 50 parts by weight of carbon black having 155 to 170 mg / g of iodine adsorption, 100 to 120 ml / 100 g and 110 to 130% coloring degree, BET adsorption value of 150 to 170 m ² / g and DBP adsorption to 100 parts by weight of raw material rubber 5 to 20 parts by weight of precipitated silica of 180 to 200 ml / 100g, fatty acid metal which is a compound of at least one metal selected from fatty acids, zinc and potassium, and contains 1 to 5 parts by weight of a silica dispersant having a softening point of 95 to 105 ° C. A tire tread rubber composition characterized by the above-mentioned. delete delete