KR101442216B1 - Rubber composition for tire tread and tire manufactured by using the same - Google Patents

Abstract

The present invention relates to a rubber composition for a tire tread and a tire produced using the same. The rubber composition for a tire tread of the present invention comprises 100 parts by weight of a raw rubber, 1 to 150 parts by weight of a reinforcing filler, 20 parts by weight.
The rubber composition for a tire tread can maintain both the braking performance, the wear performance and the low fuel consumption performance at an appropriate level or more, and can prevent the environmental pollution as the waste rubber as the industrial waste is recycled, and can greatly reduce the manufacturing cost .

Description

TECHNICAL FIELD [0001] The present invention relates to a rubber composition for a tire tread, and a tire manufactured using the same. BACKGROUND OF THE INVENTION [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber composition for a tire tread and a tire produced using the rubber composition. More particularly, the present invention relates to a rubber composition for a tire tread, The present invention relates to a rubber composition for a tire tread capable of preventing contamination and greatly reducing manufacturing cost, and a tire made using the same.

Recently, environmental problems have been rising all over society. Polymers and rubber materials used for various household goods, automobile parts, parts for electric and electronic products, etc., It is becoming a problem.

Therefore, in order to effectively utilize resources and prevent environmental pollution, which has emerged as a serious social problem, interest and research on the treatment and recycling of industrial waste materials including polymer and rubber materials are continuously being continued.

In particular, the recycling of tire rubber is generally performed by removing the worn tread and re-vulcanizing it to make recycled tires. However, after the use of recycled tires, it is converted to waste, which is not a fundamental solution to the problem of environmental pollution.

In addition, there is a method in which rubber waste is made into a small particle powder or a piece of rubber chip to be recycled, and the rubber chip is partially used as a floor material such as a sidewalk block or an exercise facility and an exterior material of a building, However, when a rubber chip is applied, no chemical bond is formed between the interface of the rubber and the waste rubber chip, so that stress at the interface between the rubber and the waste rubber chip at the time of material breakage The cracks are easily generated and the fracture is easily caused.

Also, a patent for a rubber composition for a tire tread, which is obtained by collecting waste tires, pulverizing the rubber tires to a size of 45 to 250 탆 and using 5 to 30 parts by weight of the rubber and using 5 to 30 parts by weight of unvulcanized rubber 2002-0032848). However, since this technique does not form any chemical bond between the rubber and the waste rubber powder like the waste rubber chip technology, stress is concentrated at the interface between the rubber and the waste rubber chip when the material is broken, There is a problem in that it easily occurs and breakage due to this occurs easily. In addition, there is a case where the regenerant after grinding is mixed and heated to about 200 ° C to cause heat aging and depolymerization to soften and regenerate and mix with the new rubber to produce a rubber product, In the case of vulcanization, the physical properties such as tensile strength, elongation and tensile strength of the finally produced elastomer are remarkably lowered, and the practical utilization is low.

Korea Patent No. 0187496 (published on December 31, 1998) Korean Patent Publication No. 2002-0032848 (published on May 4, 2002)

It is an object of the present invention to provide a rubber composition for a tire tread according to the present invention in which both the braking performance, the abrasion performance and the low fuel consumption performance are maintained at an appropriate level or higher and the environmental pollution can be prevented by recycling the waste rubber as the industrial waste, The manufacturing cost can be reduced.

Another object of the present invention is to provide a tire produced by using the rubber composition for a tire tread.

In order to achieve the above object, the rubber composition for a tire tread according to an embodiment of the present invention comprises 100 parts by weight of raw rubber, 1 to 150 parts by weight of a reinforcing filler, and 5 to 20 parts by weight of a desulfurized regenerated rubber.

The sulfur content of the desulfurized regenerated rubber may be 0.020 wt% or less with respect to the total amount of the desulfurized regenerated rubber.

The desulfurized regenerated rubber may be pulverized to 80 to 120 mesh.

The desulfurized regenerated rubber may have a content of polyaromatic hydrocarbon of 10% by weight or less with respect to the whole of the desulfurized recycled rubber.

The rubber composition for a tire tread may further comprise 30 to 80 parts by weight of carbon black having a nitrogen adsorption specific surface area of 30 to 200 m 2 / g and a dibutyl phthalate oil absorption of 60 to 130 cc / 100 g.

The rubber composition for a tire tread may contain carbon black and silica in a weight ratio of 50:20 to 40:30.

A tire according to another embodiment of the present invention is manufactured using the rubber composition for a tire tread.

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

The rubber composition for a tire tread according to an embodiment of the present invention includes 100 parts by weight of raw rubber, 1 to 150 parts by weight of a reinforcing filler, and 5 to 20 parts by weight of a desulfurized regenerated rubber.

The raw material rubber may be any one selected from the group consisting of natural rubber, synthetic rubber, and combinations thereof.

The natural rubber may be a general natural rubber or a modified natural rubber.

The above-mentioned general natural rubber may be used as long as it is known as natural rubber, and the country of origin and the like are not limited. The natural rubber includes cis-1,4-polyisoprene as a main component, but may also include trans-1,4-polyisoprene depending on required characteristics. Therefore, in addition to natural rubber containing cis-1,4-polyisoprene as a main component, natural rubber including trans-1,4-isoprene as a main component, such as balata, Rubber may also be included.

The modified natural rubber means that the general natural rubber is modified or purified. Examples of the modified natural rubber include epoxidized natural rubber (ENR), deproteinized natural rubber (DPNR), hydrogenated natural rubber and the like.

The synthetic rubber may be at least one selected from the group consisting of styrene butadiene rubber (SBR), modified styrene butadiene rubber, butadiene rubber (BR), modified butadiene rubber, chlorosulfonated polyethylene rubber, epichlorohydrin rubber, fluorine rubber, silicone rubber, Butadiene rubber, nitrile rubber, nitrile butadiene rubber (NBR), modified nitrile butadiene rubber, chlorinated polyethylene rubber, styrene ethylene butylene styrene (SEBS) rubber, ethylene propylene rubber, ethylene propylene diene (EPDM) rubber, Ethylene vinyl acetate rubber, acrylic rubber, hydrin rubber, vinyl benzyl chloride styrene butadiene rubber, bromomethyl styrene butyl rubber, maleic styrene butadiene rubber, carboxylic styrene butadiene rubber, epoxy isoprene rubber, ethylene propylene rubber maleic acid, Nitrile butadiene rubber Brominated polyisobutyl isoprene-co-paramethystyrene (BIMS), and combinations thereof. The term " polyisobutyl isoprene-co-paramethystyrene "

The reclaimed rubber may be a reclaimed rubber produced through a crushing and desulfurizing process of the tire tread. Specifically, the reclaimed rubber is obtained by pulverizing a waste tire, removing a cord and other foreign matter, and subjecting it to a desulfurization process. Since the rubber composition for a tire tread contains both the crushed and desulfurized recycled rubber, both the braking performance, the wear performance and the low fuel consumption performance are maintained at an appropriate level or higher, the environmental pollution is prevented by recycling the waste rubber as the industrial waste, The manufacturing cost can be reduced. In addition, the regenerated rubber forms some chemical bonds with the unvulcanized rubber as a raw rubber by a desulfurization step, so that the physical properties of the vulcanized rubber can be prevented from lowering.

The regenerated rubber may have a sulfur content of 0.020 wt% or less, preferably 0.015 wt% or less. When the sulfur content of the reclaimed rubber exceeds 0.020 wt%, chemical bonds are not formed between the recycled rubber and the rubber due to a large number of crosslinked sulfur in the reclaimed rubber, so that stress is concentrated on the interface between the rubber and the waste rubber chip There is a problem that cracks easily occur and breakage due to the cracks easily occurs.

The reclaimed rubber has a particle size of 80 to 120 mesh. If the particle size of the reclaimed rubber is less than 80 mesh, the mechanical properties may be deteriorated due to the dispersion problem in the rubber due to the large particle size. If the size exceeds 120 mesh, The price of the raw material may increase.

The regenerated rubber may be an eco-friendly regenerated rubber having a content of polyaromatic hydrocarbons of 10 wt% or less with respect to the whole of the regenerated rubber as it is desulfurized.

The reclaimed rubber may be included in an amount of 5 to 20 parts by weight, preferably 10 to 20 parts by weight, based on 100 parts by weight of the raw rubber. When the content of the reclaimed rubber is less than 10 parts by weight with respect to 100 parts by weight of the raw material rubber, the effect of remarkably reducing the manufacturing cost is insufficient. When the reclaimed rubber exceeds 20 parts by weight, Physical properties such as abrasion performance and low fuel consumption performance may be deteriorated.

The reinforcing filler may be any one selected from the group consisting of carbon black, silica, and mixtures thereof.

When the rubber composition for a tire tread including the desulfurized reclaimed rubber contains carbon black alone as a reinforcing filler, the braking performance and the manufacturing cost are reduced, while the wear performance and the fuel consumption performance are slightly lowered .

Therefore, the rubber composition for a tire tread may contain the carbon black and the silica in a weight ratio of 50:20 to 40:30 in order to prevent the abrasion performance and the fuel-efficiency deterioration. When carbon black and silica are used together at the same weight ratio, even when the recycled rubber is used in an amount of 5 to 20 parts by weight, the abrasion performance and the low fuel consumption performance can be secured, and the wet road surface braking performance can be improved.

If the weight ratio of the silica is more than 30, there is no effect of improving the abrasion performance of the tire due to the decrease in hardness. If the weight ratio is less than 20, the improvement of the fuel consumption performance may not be obtained.

The reinforcing filler may be included in an amount of 1 to 150 parts by weight, preferably 50 to 90 parts by weight, based on 100 parts by weight of the raw rubber. When the content of the reinforcing filler is less than 1 part by weight with respect to 100 parts by weight of the raw material rubber, the reinforcing performance by the filler may be insufficient. When the content is more than 150 parts by weight, the workability of the tire rubber composition may be deteriorated.

When carbon black is used alone as the reinforcing filler, the carbon black may have a nitrogen surface area per gram (N 2 SA) of 30 to 200 m ² / g, preferably 60 to 120 m ² / g . If the N2SA value of the carbon black exceeds 200 m ² / g, there is a surface favorable for reinforcing the cutting and chipping performance, but the workability of the tire rubber composition may be deteriorated. If the N ² SA value is less than 30 m ² / g, The blackness may rather deteriorate the stiffness.

The carbon black may be a high surface area carbon black having a large nitrogen adsorption specific surface area value or a low surface area carbon black having a small nitrogen adsorption specific surface area value. The high surface area carbon black may have a nitrogen adsorption specific surface area in a range of 105 to 200 m 2 / g, preferably a nitrogen adsorption specific surface area in a range of 120 to 180 m 2 / g, more preferably a nitrogen adsorption specific surface area Lt; 2 > / g. The high surface area carbon black may be, for example, tread black ASTM N100 grade and N200 grade carbon black. The low surface area carbon black may have a nitrogen adsorption specific surface area of 30 m 2 / g or more and less than 105 m 2 / g, preferably a nitrogen adsorption specific surface of 50 m 2 / g or more and less than 105 m 2 / g, The surface area may be less than 70 m2 / g and less than 105 m2 / g. The low surface area carbon black may be, for example, tread black ASTM N300 grade carbon black.

The carbon black may have an oil absorption of DBP (n-dibutyl phthalate) of 60 to 130 cc / 100 g. If the DBP oil absorption of the carbon black exceeds 130 cc / 100 g, the workability of the rubber composition may be deteriorated. If the DBP oil absorption is less than 60 cc / 100 g, the reinforcing performance by the carbon black as the filler may be deteriorated.

The silica may have a nitrogen adsorption specific surface area of 100 to 180 m2 / g and a CTAB value of 110 to 170 m2 / g, but the present invention is not limited thereto. Ultrasil 7000 (Ebonic Degussa) Ultrasil VN2 (Ebonic Degussa), Ultrasil VN3 (Ebonic Degussa), and the like can be used as the above-mentioned silica. 1165MP (Rhodia) and the like can be used.

The rubber composition for a tire may further include various additives such as additional vulcanizing agents, vulcanization accelerators, vulcanization accelerators, coupling agents, anti-aging agents, and softening agents. Any of the various additives may be used as long as they are commonly used in the field to which the present invention belongs. The content thereof is not particularly limited as long as it is dependent on the blending ratio used in a conventional rubber composition for a tire.

The rubber composition for a tire can be produced through a conventional two-step continuous production process. That is, during the finishing step in which the first step (referred to as the non-production step) and the crosslinking system are thermom mechanically treated or kneaded at a maximum temperature of 110 to 190 캜, preferably at a high temperature of 130 to 180 캜, And a second step (referred to as a production step) of mechanically treating at a low temperature of less than 110 deg. C, for example, 40 to 100 deg. C, in a suitable mixer, but the present invention is not limited thereto.

The rubber composition for a tire may be included in various rubber components constituting the tire. Said rubber components include treads (tread caps and tread bases), sidewalls, sidewall inserts, apex, chafer, wire coat or inner liner. Preferably a rubber composition for a tire tread.

A tire according to another embodiment of the present invention is manufactured using the rubber composition for a tire. The method of manufacturing a tire using the rubber composition for a tire may be any method conventionally used for manufacturing a tire, and a detailed description thereof will be omitted herein.

The tires may be automobile tires, racing tires, airplane tires, agricultural tires, off-the-road tires, truck tires or bus tires. Further, the tire may be a radial tire or a bias tire, and preferably a radial tire.

The rubber composition for a tire tread of the present invention can maintain both the braking performance, the wear performance and the low fuel consumption performance at an appropriate level or higher, and can prevent the environmental pollution as the waste rubber as the industrial waste is recycled, .

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

[ Manufacturing example  1: Preparation of rubber composition]

Rubber compositions for tire treads according to the following Examples and Comparative Examples were prepared using the compositions shown in Table 1 below. The production of the rubber composition was in accordance with the usual production method of the rubber composition.

(Unit: parts by weight) Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 E-SBR ⁽¹⁾ 90 (23) Ni-BR ⁽²⁾ 10 Recycled rubber ⁽³⁾ - - 10 20 30 Waste of rubber ⁽⁴⁾ - 20 - - - Carbon black 80 80 80 80 80 Softener (TDAE oil) 5 Zinc oxide 3 Stearic acid 2 Antioxidant 5 brimstone 2 accelerant 1.8

Company

(1) E-SBR: Emulsion-polymerized styrene-butadiene rubber (E-SBR) prepared by a batch process in which the styrene content is 25 to 40 wt% and the vinyl content in the butadiene is 25 to 50 wt%, TDAE oil 23.5 PHR extended (The number in parentheses is the oil content)

(2) Ni-BR: Nickel-butadiene rubber made by Kumho Petrochemical Co.

(3) Regenerated rubber: Korean industrial desulfurized regenerated rubber 80 MESH (sulfur content 0.015 wt% or less)

(4) Waste rubber powder: Waste rubber powder Particle size 150 to 250 탆 (content of sulfur 0.025% by weight)

[ Experimental Example  1: Measurement of physical properties of the prepared rubber composition]

The physical properties of the rubber specimens prepared in Examples 1 and 2 were measured and the results are shown in Table 2 below.

Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Mooney viscosity (125 ° C) 69 73 73 71 70 Hardness (Shore A) 67 71 66 67 66 300% modulus (Mpa) 12.1 12.5 11.8 10.8 10.0 Elongation (%) 486 397 426 444 480 Wear Index 100 80 95 94 84 0 deg. 0.191 0.182 0.214 0.209 0.196 60 deg. 0.175 0.172 0.174 0.178 0.184 Manufacturing Price (Index) 100 91 97 94 91

- Mooney viscosity (ML1 + 4 (125 占 폚)) was measured according to ASTM standard D1646.

- Hardness was measured by DIN 53505.

- 300% Modulus and elongation were measured according to ISO 37 standard.

- Index is a value obtained by indexing the loss of abraded rubber by rotating at a slip ratio of 25% at normal temperature and a load of 1.5 kg as a ratio of Lambourn abrasion tester, based on Comparative Example 1.

* Wear = (worn amount of the comparative example / worn amount of the embodiment) x 100

- The viscoelasticity was measured by using an RDS measuring instrument at a temperature of -60 ° C to 80 ° C at a frequency of 10 Hz at a strain of 0.1%.

- The manufacturing unit cost is indexed based on Comparative Example 1.

As can be seen from the results of Table 2 above, the rubber specimens of Examples 1 to 3 produced by the tread rubber composition of the present invention had better braking performance and wear performance than the rubber specimen of Comparative Example 1, Fuel efficiency performance is maintained at an appropriate level and above. In particular, it shows the effect of preventing environmental pollution caused by the recycling of waste rubber, which is an industrial waste, and greatly reducing the manufacturing cost.

On the other hand, when the waste rubber powder not subjected to desulfurization is used as in Comparative Example 2, chemical bonding with rubber does not occur, so that wear and braking performance are inevitably reduced.

[ Manufacturing example  2: Preparation of rubber composition]

Rubber compositions for tire treads according to the following Examples and Comparative Examples were prepared using the compositions shown in Table 3 below. The production of the rubber composition was in accordance with the usual production method of the rubber composition.

(Unit: parts by weight) Comparative Example 3 Comparative Example 4 Example 4 Example 5 Example 6 Example 7 NR ⁽¹⁾ 20 S-SBR ⁽²⁾ 40 (15) Ni-BR ⁽³⁾ 40 Recycled rubber ⁽⁴⁾ - - 10 10 20 20 Carbon black 60 50 60 50 40 30 Silica - 20 - 20 30 40 Coupling agent - 3.5 - 3.5 4.7 5.9 Softener (TDAE oil) 5 Zinc oxide 3 Stearic acid One Antioxidant 5 brimstone 1.5 accelerant 2

Company

(1) NR: natural rubber obtained from nature, the chemical name is polyisoprene

(2) E-SBR: solution polymerized styrene-butadiene rubber (S-SBR) prepared by the continuous process in which the styrene content is 25 to 40 wt% and the vinyl content in the butadiene is 25 to 50 wt%, TDAE oil 37.5 PHR extended (content in parentheses is oil content)

(3) Ni-BR: Nickel-butadiene rubber made by Kumho Petrochemical Co.

(4) Regenerated rubber: Korean industrial desulfurized regenerated rubber 80 MESH (sulfur content 0.015 wt% or less)

[ Experimental Example  2: Measurement of physical properties of the prepared rubber composition]

The physical properties of the rubber specimens prepared in Examples and Comparative Examples were measured and the results are shown in Table 4 below.

Comparative Example 3 Comparative Example 4 Example 4 Example 5 Example 6 Example 7 Mooney viscosity (125 ° C) 75 77 77 77 76 79 Hardness (Shore A) 67 68 67 68 66 65 300% modulus (Mpa) 10.9 10.1 10.0 10.5 10.3 9.8 Elongation (%) 492 500 435 474 471 480 Wear Index 100 101 97 101 100 96 0 deg. 0.209 0.213 0.218 0.223 0.225 0.220 60 deg. 0.170 0.168 0.174 0.168 0.169 0.184 Manufacturing Price (Index) 100 102 96 98 97 99

- Mooney viscosity (ML1 + 4 (125 占 폚)) was measured according to ASTM standard D1646.

- Hardness was measured by DIN 53505.

- 300% Modulus and elongation were measured according to ISO 37 standard.

- Index is a value obtained by indexing the loss of abraded rubber by rotating at a slip ratio of 25% at normal temperature and a load of 1.5 kg as a ratio of Lambourn abrasion tester, based on Comparative Example 1.

* Wear = (worn amount of the comparative example / worn amount of the embodiment) x 100

- The viscoelasticity was measured by using an RDS measuring instrument at a temperature of -60 ° C to 80 ° C at a frequency of 10 Hz at a strain of 0.1%.

- The manufacturing unit cost is indexed based on Comparative Example 1.

As can be seen from the results of Table 4, the rubber specimens of Examples 4 to 7 prepared by the tread rubber composition of the present invention had better braking performance and wear performance than the rubber specimens of Comparative Examples 3 and 4, And fuel efficiency performance are both maintained at an appropriate level. In particular, it shows the effect of preventing environmental pollution caused by the recycling of waste rubber, which is an industrial waste, and a significant reduction in manufacturing cost.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

Claims (7)

100 parts by weight of the raw rubber,
1 to 150 parts by weight of a reinforcing filler comprising carbon black and silica, and
5 to 20 parts by weight of a desulfurized regenerated rubber,
Carbon black, and silica in a weight ratio of 10: 50: 20 to 20: 40: 30. The method according to claim 1,
And the sulfur content of the desulfurized recycled rubber is 0.020% by weight or less based on the total amount of the desulfurized recycled rubber. The method according to claim 1,
Wherein the desulfurized regenerated rubber is pulverized to 80 to 120 mesh. The method according to claim 1,
Wherein the rubber composition for a tire tread has a polyaromatic hydrocarbon content of 10% by weight or less with respect to the whole rubber composition for a tire tread. The method according to claim 1,
Wherein the rubber composition for a tire tread further comprises 30 to 80 parts by weight of carbon black having a nitrogen adsorption specific surface area of 30 to 200 m < 2 > / g and a dibutyl phthalate oil absorption of 60 to 130 cc / 100 g. delete A tire produced by using the rubber composition for a tire tread according to claim 1.