KR101354443B1 - Tire tread rubber composition improved dispersion property of silica - Google Patents

Abstract

The present invention relates to a tire tread rubber composition having improved dispersibility of silica, and more particularly, to a tire tread rubber composition having silica, capable of improving the dispersibility of high-specific surface area silica by including 60-80 parts by weight of high-specific area silica having a specific area of 180 m^2/g or more and 1-10 parts by weight of at least one silica dispersant selected from Chemical Formulas (1) and (2) below, based on 100 parts by weight of a rubber raw material, thereby preventing material degradations, such as, a defect in the mix and dispersion of high-specific area silica, a defect in extruding processability, and a temperature increase at the time of rubber composition mixing, and improving rotation resistance.

Description

Tire tread rubber composition improved dispersion property of silica

The present invention relates to a tire tread rubber composition having improved silica dispersibility. More specifically, in a tire tread rubber composition including silica, a high specific surface area silica having a specific surface area of at least 180 m ² / g based on 100 parts by weight of raw material rubber It contains 60 to 80 parts by weight, 1 to 10 parts by weight of any one or more silica dispersants selected from the following formulas (1) and (2) to improve the dispersibility of the high specific surface area silica, resulting in poor dispersion and extrusion processability of the high specific surface area silica. It relates to a tire tread rubber composition that can improve the rotational resistance characteristics as well as preventing performance deterioration, such as temperature rise during the formulation of the rubber composition.

...화학식(1)

(1)

... Formula (2)

The tire has several parts in structure, and the most important part of the tire part is a tread part which is in contact with the ground and directly acts on the movement, rotation, and stopping of the vehicle.

Since the tread of the tire is in direct contact with the ground, such as moving, turning, and stopping the vehicle, various characteristics such as abrasion resistance, braking resistance, steering stability, and low rolling resistance are required for this role.

Tire tread uses various kinds of additives to meet the required characteristics, and in particular, carbon black and silica are used as reinforcing fillers to improve the reinforcement of the tire tread rubber composition.

Among the reinforcing fillers used in tire tread rubber compositions, silica not only contributes to improved fuel efficiency by lowering rolling resistance, but also superior to carbon black in terms of braking and steering stability, and thus the use of silica as a reinforcing filler is continuously increasing.

Silica mainly uses Z-115 grade or Z-175 grade general purpose silica, but the specific surface area is gradually increased because the use of high specific surface area silica is better than that of general purpose silica. High specific surface area silica of 180 m ² / g or more is used.

On the other hand, silica has a property to agglomerate with each other. Thus, when silica is not aggregated with each other in the rubber composition and evenly dispersed in the rubber composition, the physical properties of the rubber are reduced by agglomeration at specific sites of the silica. In order to prevent agglomeration of silica, a silica dispersant is used to improve dispersibility of silica in the rubber composition including silica, and a silane coupling agent including silane is mainly used for a silica dispersant which is generally used. have.

However, as mentioned above, when a high specific surface area silica having a specific surface area of 180 m ² / g or more is used in a rubber composition, when a general silica dispersant is used to improve the dispersibility of high specific surface area silica, silica dispersibility is insignificant. There is a problem that is difficult to prevent.

Accordingly, in the present invention, the rubber composition containing the high specific surface area silica having a specific surface area of 180 m ² / g or more is included as a silica dispersant so as to include any one or more selected from the following formulas (1) and (2). The present invention aims to provide a tire tread rubber composition that can improve the rotational resistance characteristics as well as prevent performance deterioration such as poor mixing and dispersing of high specific surface area silica, poor extrusion processability, and temperature rise during mixing of the rubber composition.

...화학식(1)

(1)

...화학식(2)

... Formula (2)

On the other hand, in the tread rubber composition for improving tire rolling resistance and braking property according to the prior art related to the present invention, the nitrogen adsorption specific surface area of 150 to 180 ㎡ with respect to 100 phr of synthetic rubber Rubber composition for tire treads, characterized in that 40 to 60 phr of silica having a absorption rate of 270 to 300 cc / 100 g / g of dioxyl phthalate, 2 to 8 phr of dispersant is added, and 2 to 3 phr of diethylene glycol is used to prevent moisture absorption of the accelerator. Indicates.

In the silica rubber composition known from Korean Patent Laid-Open No. 2002-0080021, a silica rubber composition having improved dispersibility is characterized in that it comprises 3 to 12 phr of recycled soap made from waste vegetable oil as a dispersant with respect to 100 phr of raw rubber. It is shown.

However, the present invention and the prior art are inventions with different configurations of the invention because of different technical features of the invention.

The present invention improves the dispersibility of high specific surface area silica in a rubber composition containing high specific surface area silica having a specific surface area of 180 m ² / g or more, such as poor mixing and dispersing of high specific surface area silica, poor processability in extrusion, and a temperature rise during mixing of the rubber composition. To provide a tire tread rubber composition that can prevent performance degradation as well as improve the rolling resistance characteristics.

The present invention improves the dispersibility of high specific surface silica by including at least one selected from the following formulas (1) and (2) as a silica dispersant in a rubber composition containing high specific surface area silica having a specific surface area of 180 m ² / g or more. It is to provide a tire tread rubber composition that can improve the rotational resistance characteristics as well as to prevent performance degradation such as poor mixing and dispersing of high specific surface area silica, poor extrusion processability, temperature increase when mixing the rubber composition.

...화학식(1)

(1)

...화학식(2)

... Formula (2)

The present invention improves the dispersibility of high specific surface area silica in a rubber composition containing high specific surface area silica having a specific surface area of 180 m ² / g or more, such as poor mixing and dispersing of high specific surface area silica, poor processability in extrusion, and a temperature rise during mixing of the rubber composition. It is possible to provide a tire tread rubber composition that can prevent performance degradation and improve rolling resistance characteristics.

In the tire tread rubber composition comprising silica, 60 to 80 parts by weight of the specific surface area silica having a specific surface area of 180 m ² / g or more, based on 100 parts by weight of the raw material rubber, selected from the following formula (1) and formula (2) A tire tread rubber composition comprising 1 to 10 parts by weight of any one or more silica dispersants is shown.

...화학식(1)

(1)

...화학식(2)

... Formula (2)

The raw rubber may be a natural rubber alone.

The synthetic rubber may be used alone as the raw material rubber.

The raw rubber may be a mixed rubber in which natural rubber and synthetic rubber are mixed.

The raw rubber may be a mixed rubber in which the natural rubber and the synthetic rubber are mixed in a weight ratio of 5: 95: 5 to 95.

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, Butadiene rubber, maleic acid styrene butadiene rubber, epoxy styrene butadiene rubber, epoxy isoprene rubber, maleic acid ethylene propylene rubber, carboxymethyl styrene butadiene rubber, acrylonitrile butadiene rubber, acrylonitrile butadiene rubber, acrylonitrile butadiene rubber, acrylonitrile butadiene rubber, ethylene vinyl acetat rub, acryl rubber, hydrin rubber, vinyl benzyl chloride styrene butadiene rubber, Bicarboxylic acid nitrile butadiene rubber and BIMS (brominated polyisobutyl isoprene e-co-paramethyl styrene) may be used.

The high specific surface area silica having a specific surface area of 180 m ² / g or more does not mean to use high specific surface area silica as a reinforcing filler when it is used less than 60 parts by weight based on 100 parts by weight of the raw material rubber. There is no apparent increase in the effects of the use of surface area silica, and there is a concern that the physical properties of the rubber composition may decrease.

Therefore, 60 to 80 parts by weight of high specific surface area silica having a specific surface area of 180 m ² / g or more is preferably used.

In the above, the high specific surface area silica having a specific surface area of 180 m ² / g or more may use silica having a specific surface area of 180 to 250 m ² / g.

In the above-described high specific surface area silica having a specific surface area of 180 m ² / g or more, silica having a specific surface area of 185 to 235 m ² / g may be used.

When the silica dispersant is less than 1 part by weight based on 100 parts by weight of the raw material rubber, the role of the silica dispersant is insignificant. When the silica dispersant is used in excess of 10 parts by weight, there is no obvious effect increase due to the use of excess silica dispersant, and the rubber composition There is a fear that the physical properties of.

Therefore, it is preferable to use 1-10 weight part of silica dispersing agents with respect to 100 weight part of raw material rubbers.

In the case where the silica dispersant of the formula (1) and the silica dispersant of the formula (2) are used simultaneously as the silica dispersant, the silica dispersant of the formula (1) and the silica dispersant of the formula (2) are 1: 9 to 9: 1 Mixed silica dispersants mixed in weight ratios can be used.

Tire tread rubber composition comprising a silica of the present invention may further include an additive for improving physical properties.

The additive may be used in an amount of 5 to 15 parts by weight based on 100 parts by weight of the raw rubber.

The additive may be carbon fiber.

The additive may be a carbon fiber having a size of 0.1 to 1 mm.

The present invention, in addition to the above-mentioned raw rubber, high specific surface area silica and silica dispersant, various additives used in the conventional tire tread rubber composition may be appropriately selected and used in a predetermined content as necessary. However, these are general components used in conventional tire tread rubber compositions and are not essential constituents of the present invention, and therefore, detailed description thereof will be omitted.

Since the tire tread rubber composition of the present invention was carried out under various conditions, in order to achieve the object of the present invention, it is preferable to provide a tire tread rubber composition under the above-mentioned conditions.

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

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

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

The present invention includes a tire containing a rubber composed of the above-mentioned rubber composition, wherein the tire is any one selected from the group of automobile tires, truck tires, bus tires, aircraft tires, and motorcycle tires .

Hereinafter, the present invention will be described in detail with reference to Examples, Comparative Examples and Test Examples. However, these are for the purpose of illustrating the present invention in more detail, and the scope of the present invention is not limited thereto.

≪ Example 1 >

60 parts by weight of high specific surface area silica, 3 parts by weight of silica dispersant of formula (1), 3 parts by weight of zinc oxide (ZnO), stearic acid (stearic) based on 100 parts by weight of a raw material rubber composed of 100 parts by weight of styrene butadiene rubber (SBR-1500) acid), 2 parts by weight of wax, 1.5 parts by weight of wax, and 2 parts by weight of N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine as an anti-aging agent were added to a Banbury mixer to mix the rubber compound. Got it.

Rubber parts were prepared by adding 2 parts by weight of sulfur as a vulcanizing agent and 1 part by weight of N-cyclohexyl-2-benzothiazole-sulfenamide (CZ) as a vulcanizing agent and vulcanizing at 160 ° C. for 25 minutes. .

In the above-described high specific surface area silica, silica (200 MP) having a specific surface area of 220 m ² / g was used.

...화학식(1)

(1)

The rubber composition of Example 1 is shown in Table 1 below.

<Example 2>

A rubber specimen was prepared in the same manner as in Example 1 except for using the silica dispersant of the formula (2) as the silica dispersant.

...화학식(2)

... Formula (2)

<Comparative Example>

A rubber specimen was prepared in the same manner as in Example 1 except for using HT-204 of Struktol as a silica dispersant instead of the silica dispersant of Formula (1).

Composition of Example 1-2 and Comparative Example Item Comparative Example Example 1 Example 2 Raw material rubber (SBR-1500) 100 100 100 Silica (200 MP) 60 60 60 Silica dispersant 3 3 3 Zinc oxide (ZnO) 3 3 3 Stearic acid 2 2 2 Wax 1.5 1.5 1.5 Antioxidant 2 2 2 brimstone 2 2 2 Vulcanization accelerator (NS) One One One

&Lt; Test Example 1 >

ASTM-related physical properties such as rheometer, Mooney viscosity, Tensile, GABO, and Abrasion for each rubber specimen prepared in Examples 1, 2, and Comparative Examples Measured according to the regulations and the results are summarized in Table 2 below.

Rubber Specimen Property Results of Examples 1-2 and Comparative Examples Item Comparative Example Example 1 Example 2 Rheometer
(Rheo)
Toq (Max) 64.7 63.5 63.5 T90 8.9 9.2 9.2 Mooney
Viscosity
Viscosity 98 93 90 T05 15.5 16.4 16.4 Tensile properties
(Tensile)
Hard's 79 79 79 100% modulus
(100% Modulus) 58 60 62 Tensile Strength (T.S) 195 210 222 GABO

Tg -29.5 -31.2 -31.2 Tan δ (0 ℃) 0.243 0.252 0.255 Tan δ (70 ° C) 0.120 0.118 0.117 Abrasion DIN 0.058 0.056 0.056

* Tan δ (0 ℃): Wet predicts the wet traction characteristics of wet tires. The higher the value, the better.

* Tan δ (70 ℃): It is a value that can predict rolling resistance characteristics of tire performance. The lower the value, the better.

* DIN: It shows the wear resistance. The lower the value, the better the wear resistance.

As shown in the results of Table 2, it can be seen that the rubber prepared in Examples 1 and 2 of the present invention has excellent tensile properties, wear resistance, braking force, and rolling resistance when compared with the rubber prepared in Comparative Example.

&Lt; Test Example 2 &

100 ℃ Capillary shrinkage (1mm / s surface roughness and 2mm / s surface roughness) for each rubber specimen prepared in Examples 1, 2 and Comparative Examples was measured according to ASTM regulations and the results are as follows. Table 3 shows the result.

Rubber Specimen Property Results of Examples 1-2 and Comparative Examples division Comparative Example Example 1 Example 2 100 ℃ Capillary
Shrinkage rate
1mm / s
Surface roughness 97.5%
Surface defect 99.3%
Surface superiority 98.8%
Surface superiority 2mm / s
Surface roughness 97.0%
Surface defect 98.7%
Surface superiority 98.5%
Surface superiority

As a result of comparing the capillary passing speed, shrinkage rate and surface roughness assuming extrusion speed as shown in Table 3, Example 1 and Example 2 were much lower in shrinkage rate than the comparative example, and therefore, excellent in profile numerical stability of the extrudate. . In addition, since the surface roughness is excellent, it is advantageous for the stamping of the surface of the extrudate, which may contribute to the reduction in overall productivity and defective rate.

<Example 3>

60 parts by weight of high specific surface area silica, 100 parts by weight of a raw material rubber consisting of 100 parts by weight of styrene butadiene rubber (SBR-1500), 3 parts by weight of a silica dispersant in which the following formulas (1) and (2) are mixed in a weight ratio of 1: 1 , 3 parts by weight of zinc oxide (ZnO), 2 parts by weight of stearic acid, 1.5 parts by weight of wax, N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylene as an antioxidant 2 parts by weight of diamine was added to a Banbury mixer and blended to obtain a rubber compound.

Rubber parts were prepared by adding 2 parts by weight of sulfur as a vulcanizing agent and 1 part by weight of N-cyclohexyl-2-benzothiazole-sulfenamide (CZ) as a vulcanizing agent and vulcanizing at 160 ° C. for 25 minutes. .

In the above-described high specific surface area silica, silica (200 MP) having a specific surface area of 220 m ² / g was used.

...화학식(1)

(1)

...화학식(2)

... Formula (2)

&Lt; Example 4-1 >

70 parts by weight of high specific surface area silica, 5 parts by weight of silica dispersant of formula (1), 5 parts by weight of carbon fiber, and zinc oxide (ZnO) 3 with respect to 100 parts by weight of a raw material rubber composed of 100 parts by weight of styrene butadiene rubber (SBR-1500) Parts by weight, 2 parts by weight of stearic acid, 1.5 parts by weight of wax, and 2 parts by weight of N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine as an anti-aging agent to a Banbury mixer. It was added and blended to obtain a rubber compound.

Rubber parts were prepared by adding 2 parts by weight of sulfur as a vulcanizing agent and 1 part by weight of N-cyclohexyl-2-benzothiazole-sulfenamide (CZ) as a vulcanizing agent and vulcanizing at 160 ° C. for 25 minutes. .

In the above-described high specific surface area silica, silica (200 MP) having a specific surface area of 220 m ² / g was used.

In the above, the carbon fiber used was 0.5mm in size.

...화학식(1)

(1)

&Lt; Example 4-2 >

A rubber specimen was manufactured in the same manner as in Example 4-1, except that 10 parts by weight of carbon fibers were used.

<Example 4-3>

A rubber specimen was manufactured in the same manner as in Example 4-1, except that 15 parts by weight of carbon fibers were used.

&Lt; Example 5-1 >

70 parts by weight of high specific surface area silica, 5 parts by weight of silica dispersant of formula (2), 5 parts by weight of carbon fiber, and zinc oxide (ZnO) 3 with respect to 100 parts by weight of a raw material rubber composed of 100 parts by weight of styrene butadiene rubber (SBR-1500) Parts by weight, 2 parts by weight of stearic acid, 1.5 parts by weight of wax, and 2 parts by weight of N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine as an anti-aging agent to a Banbury mixer. It was added and blended to obtain a rubber compound.

Rubber parts were prepared by adding 2 parts by weight of sulfur as a vulcanizing agent and 1 part by weight of N-cyclohexyl-2-benzothiazole-sulfenamide (CZ) as a vulcanizing agent and vulcanizing at 160 ° C. for 25 minutes. .

In the above-described high specific surface area silica, silica (200 MP) having a specific surface area of 220 m ² / g was used.

In the above, the carbon fiber used was 0.5mm in size.

...화학식(2)

... Formula (2)

&Lt; Example 5-2 >

A rubber specimen was manufactured in the same manner as in Example 5-1, except that 10 parts by weight of carbon fibers were used.

&Lt; Example 5-3 >

A rubber specimen was manufactured in the same manner as in Example 5-1, except that 15 parts by weight of carbon fibers were used.

&Lt; Example 6-1 >

60 parts by weight of high specific surface area silica, 100 parts by weight of a raw material rubber consisting of 100 parts by weight of styrene butadiene rubber (SBR-1500), 3 parts by weight of a silica dispersant in which the following formulas (1) and (2) are mixed in a weight ratio of 1: 1 , 5 parts by weight of carbon fiber, 3 parts by weight of zinc oxide (ZnO), 2 parts by weight of stearic acid, 1.5 parts by weight of wax, N- (1,3-dimethylbutyl) -N'- as an antioxidant 2 parts by weight of phenyl-p-phenylenediamine was added to a Banbury mixer and blended to obtain a rubber compound.

Rubber parts were prepared by adding 2 parts by weight of sulfur as a vulcanizing agent and 1 part by weight of N-cyclohexyl-2-benzothiazole-sulfenamide (CZ) as a vulcanizing agent and vulcanizing at 160 ° C. for 25 minutes. .

In the above-described high specific surface area silica, silica (200 MP) having a specific surface area of 220 m ² / g was used.

...화학식(1)

(1)

...화학식(2)

... Formula (2)

&Lt; Example 6-2 >

A rubber specimen was manufactured in the same manner as in Example 6-1, except that 10 parts by weight of carbon fibers were used.

&Lt; Example 6-3 >

A rubber specimen was manufactured in the same manner as in Example 6-1, except that 15 parts by weight of carbon fibers were used.

The present invention improves the dispersibility of high specific surface area silica in a rubber composition containing high specific surface area silica having a specific surface area of 180 m ² / g or more, such as poor mixing and dispersing of high specific surface area silica, poor processability in extrusion, and a temperature rise during mixing of the rubber composition. In addition to preventing performance degradation, it is possible to provide a tire tread rubber composition that can improve rolling resistance characteristics, thereby contributing to the development of tire-related industries, and thus there is industrial applicability.

Claims (4)

In a tire tread rubber composition comprising silica,
60 to 80 parts by weight of high specific surface area silica having a specific surface area of 180 m ² / g or more, and 1 to 10 parts by weight of any one or more silica dispersants selected from the following formulas (2) with respect to 100 parts by weight of the raw material rubber: Tire tread rubber composition.

(1)

... Formula (2) The method of claim 1,
High specific surface area silica is a tire tread rubber composition, characterized in that the specific surface area of 180 ~ 250m ² / g. A rubber comprising the rubber composition of claim 1. A tire comprising a rubber comprising the rubber composition of claim 1 or 2.