KR20000001556A - Rubber composition for tire thread improving abrasion-proof - Google Patents

Abstract

PURPOSE: A rubber composition provides the tire thread to improve abrasion-proof, having a low exothermicity and a low mileage, by using butadiene rubber to be made by the solution polymerization and using a specific carbon black as a useful reinforce for controlling the composition of butadiene Tg (glass transition temperature) and a fine structure. CONSTITUTION: The rubber composition for tire thread consists of the material rubbers 100 weight % containing of raw rubbers, i.e., diene-series rubber 100 % and butadiene rubbers 30 weight % or below; carbon blacks 30 to 100 PHR; and usual additives.

Description

Rubber composition for tire treads with improved wear resistance

The present invention relates to a rubber composition for tire treads with improved wear resistance. More specifically, the present invention provides a rubber composition that improves low heat generation, low fuel consumption as well as wear resistance by using a specific carbon black as a natural rubber and a useful reinforcing agent prepared by a solution polymerization method to control the glass transition temperature and the composition of the microstructure. It is about.

Most of the development of tires can be concentrated on the structural aspects and the development of application technology of materials used in tires. In particular, most researches have been made on the development of tires that focus on energy saving aspects and environmental issues. Recently, the tire development direction that has been made in terms of materials has been trying to develop low-cost-cost tires, high wear-resistant tires, high braking tires, and a combination of characteristics thereof. In particular, the recent tire rubber compounding technology is concentrated on the combination technology between these characteristics, and for this purpose, research and development applying many new materials recently developed have been attempted.

For example, Japanese Laid-Open Patent Publication Nos. 55-12133 and 56-127650 disclose rubber compounding compositions to which high vinyl butadiene rubber (hereinafter referred to as V-BR) are applied to heads 57-55204 and 57-. 73030 discloses a rubber compounding composition using high vinyl styrene butadiene rubber (hereinafter referred to as V-SBR), but these rubber compositions exhibit excellent high wet braking and low heat generation, while exhibiting inferior wear resistance.

In addition, although 61-141741 and 61-42552 also use V-SBR, it is known that it does not solve inferior abrasion resistance performance. Therefore, when it is difficult to expect the improvement of the physical properties through the polymer, the problem was solved by applying the increase and decrease of carbon black and a new concept of carbon black.

For example, in Patent Publication No. 59-2451, the smallest unit in which carbon black exhibits a reinforcing effect in rubber compounding is used, as well as conventional methods such as using carbon black having a small particle size or reducing the amount of carbon black used. The results of the research on the size of the gate (aggregate) have been applied to invent a formulation that improves low fuel efficiency and processability of bambury mixer (B / M) while maintaining other properties (high wear resistance and high braking). Wear resistance did not increase significantly.

In the case of the TBR tread composition, most of the rubber composition development direction is focused on the prevention of separation of the tread site through low heat and the improvement of wear-related properties (improvement of abnormal wear and chip / cut).

In particular, since the wear resistance of the tire tread portion is more influenced by the design factor of the structural aspect than the composition of the tread rubber, it is often necessary to use a method combined with the design factor. In other words, even if the tread rubber composition has a high heat generation, the tire that can obtain a stable level of tread block movement with the help of the structural technology is not generated from the structural technology and the overall heat generation is higher than that of the tire using the low heat tread rubber composition. It shows better heat generation characteristics in terms of aspect.

Already, most tire manufacturers have established stable dynamics in the tread area through Structural Mechanics (FEM), which has led to global tread abrasion resistance technologies, such as special chemicals that improve aging resistance in rubber compositions. DP-900, Durazone-37, etc. and carbon black with excellent reinforcement are used to improve vulcanizability and to improve wear resistance.

This invention makes it a subject to improve the wear resistance which is a disadvantage of the conventional low heat generation and low fuel consumption tire.

The present invention relates to a rubber composition for tire treads composed of carbon black 30 to 100 PHR and conventional additives based on 100 parts by weight of raw rubber including butadiene rubber in an amount of 30% by weight or less in natural rubber which is 100% diene rubber.

Hereinafter, the present invention will be described in detail.

As the raw material rubber of the present invention, butadiene rubber is mixed with 30% by weight or less of natural rubber which is 100% diene rubber.

The butadiene rubber is prepared by a solution polymerization method, and the microstructure composition (%) of butadiene rubber is preferably used so that the sheath content is 96% or more and the glass transition temperature (hereinafter referred to as Tg) is -100 ° C or less. Do.

In addition, 30 to 100 PHR of carbon black is used as a useful reinforcing agent.

The colloidal properties of the carbon black are preferably as follows.

CTAB (ASTM D3765-90) is 110 to 130 m 2 / g,

95 ml / 100g or more of C-DBP (ASTM D3493),

Toluene decolorization (ASTM D1613 @ 342μm) is 30 or less,

TINT (ASTM D3265-93) is greater than or equal to 115,

N2SA (ASTM D3037-93) is 110-145 m 2 / g,

STSA is 100-136 m 2 / g,

N2SA / STSA is 1.05 to 1.2, N2SA-STSA is 6 to 30.

If the CTAB is less than 110, low heat generation is excellent, but wear resistance is disadvantageous, and if it exceeds 130, heat generation is too severe and difficult to use. In addition, the C-DBP value should be greater than 95 ml / 100 g, and less than 95 ml / 100 g, which is disadvantageous to wear resistance. In addition, the surface activity and roughness factors of N2SA / STSA and N2SA-STSA should be about 1.05 to 1.2 and 6 to 30, respectively, which provide a proper combination of low heat generation and abrasion resistance. New argument.

The STSA surface area, which measures the outer surface area of carbon black, was measured using the equations proposed by DeBoer and BJH (Barrett, joyner, Halenda), and the reinforcing effect of carbon black can be defined as the surface state of carbon black than any other known method. It is proposed in the present invention as a factor.

When the amount of carbon black is too small (less than 30 PHR), a low heat generation composition may be obtained, but the reinforcing effect is lowered. When the carbon black is used in excess of 100 PHR, heat generation is increased due to poor workability, and adversely affects wear resistance.

Conventional additives used in the present invention include zinc oxide, stearic acid, 6PPD (amine antioxidant), RD (quinoline antioxidant), wax, G-SULFUR, N-tert-butyl-2-benzothiazyl sulfone Amide, N-cyclohexylthioptalimide, and the like.

Hereinafter, the present invention will be described with reference to Examples.

Examples 1-9

According to the present invention, natural rubber, glass transition temperature is -104 ℃, microstructure composition of vinyl-butadiene content of 1, trans-butadiene content of 2, cis-butadiene content of more than 96% butadiene rubber, carbon black and conventional additives To prepare a rubber composition by blending in the component ratios described in Table 1.

Comparative Examples 1 to 7

Rubber compositions were prepared in the same manner as in Examples 1 to 9, based on the component ratios shown in Table 1 below.

The unit of the component ratio of the composition of Table 1 is PHR.

Test Example

With the rubber composition specimens prepared in Examples 1 to 9 and Comparative Examples 1 to 7, the following physical properties were measured and the results are shown in Table 1 together.

Table 1

Example Comparative Example One 2 3 4 5 6 7 8 9 One 2 3 4 5 6 7 Natural rubber ^{# 1} 100 80 100 100 100 100 100 100 100 100 100 100 70 100 100 100 Butadiene rubber ^{# 2)} 30 30 30 30 30 30 30 30 30 30 30 40 30 30 30 ZnO 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 St-acid 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 6PPD 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 RD One One One One One One One One One One One One One One One One Wax (Universal) One One One One One One One One One One One One One One One One G-SULFUR 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 NS ^{# 3)} 1.4 1.4 1.4 1.4 1.4 1.4 1.4 1.4 1.4 1.4 1.4 1.4 1.4 1.4 1.4 1.4 PVI ^{# 4)} 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 Carbon black N110 50 C / B-A 50 50 90 20 50 30 N220 50 C / B-B 50 C / B-C 50 C / B-D 50 C / B-E 50 C / B-F 50 C / B-G 50 C / B-H 50 C / B-I 50 Vulcanization Hardness 73 69 74 74 78 70 74 71 73 54 76 72 66 76 64 75 M300 162 158 186 191 161 198 191 173 188 146 170 162 148 217 142 218 The tensile strength 253 230 255 272 285 249 259 263 267 198 245 233 209 233 223 243 Height @ BREAK 520 420 490 470 360 460 500 500 500 420 420 520 380 420 620 420 Wear Performance ^{# 5)} (INDEX) 100 98 100 104 106 99 101 105 103 85 105 95 93 95 96 98 BF-CHIP / CUT ^{# 6)} (INDEX) 100 104 115 114 170 108 105 142 103 85 99 85 85 72 98 96 Rebound @ 60 ℃ 53 56 51 53 53 54 52 54 52 56 53 53 56 51 54 52 Viscoelastic ^{# 7)} (INDEX) tanδ @ 0 ℃ 100 105 100 105 97 100 105 105 102 115 93 98 105 96 101 100 tanδ @ 60 ℃ 100 105 102 106 100 104 103 115 104 120 92 100 108 98 102 95

# 1) Natural rubber: Select one among RSS # 3, # 2, # 1, SMR-L, TSR-20.

# 2) Butadiene rubber: REG. BR (KOSIN), trans: 2, cis: 96%, TG:-1040 ° C.

# 3) N-tert-butyl-2-benzothiazyl sulfonamide, manufactured by FLEXSYS.

# 4) N-cyclohexylthiophthalimid, manufactured by RLEXSYS.

# 5) Index the amount of rambon abrasion that measured the wear of the specimen using abrasive stone.

# 6) The result obtained by BF-GOODRICH CHIP & CUT TESTER is indexed. The larger the index, the better.

# 7) Measured by RDS (Viscoelasticity Meter) (Strain: 5%, Frequency: 10Hz, Temperature Sweep).

The basic characteristics of the carbon black as a reinforcing agent used in the rubber composition of Table 1 are shown in Table 2 below.

TABLE 2

N110 C / B-A N220 C / B-B C / B-C C / B-D C / B-E C / B-F C / B-G C / B-H C / B-I CTAB (㎡ / g) 125 115 111 119 126 119 117 131 119 110 121 C-DBP (m1 / 100g) 100 109.5 96 108 102 128 107 96 102 106 95 N2SA (㎡ / g) 132 130 115 127 147 131 129 145 129 114 136 I2SA (㎡ / g) 141 113 117 116 127 119 119 112 117 97 117 TINT (%) 115 121 115 124 126 110 121 132 117 119 130 STSA (㎡ / g) 127 116 113 114 124 126 112 136 127 108 124 N2SA-STSA (㎡ / g) 5 14 2 13 23 5 17 9 2 6 12 N2SA / STSA 1.04 1.12 1.02 1.11 1.19 1.04 1.10 1.07 1.02 1.06 1.10 toluene @ 425nm 95 81 90 91 86 93 85 74 86 72 92 @ 342nm 98 10 98 22 12 60 7 2 85 2 28

As shown in Table 1, Examples 1 to 9 according to the present invention were excellent in low fuel consumption and wear resistance.

On the other hand, Comparative Examples 1 to 7 using carbon black blended with a composition ratio different from the present invention or outside the scope of the present invention do not have excellent physical properties as a whole, and at least one is inferior.

As described above, the present invention can obtain a rubber composition having improved heat resistance and low fuel consumption by using butadiene rubber prepared by a solution polymerization method and a specific carbon black which is a useful reinforcing agent to control Tg and microstructure composition of butadiene.

Claims (3)

A rubber composition for tire treads composed of carbon black 30 to 100 PHR and conventional additives based on 100 parts by weight of raw rubber including butadiene rubber in an amount of 30% by weight or less in natural rubber which is 100% diene rubber. The rubber composition for a tire tread according to claim 1, wherein the butadiene rubber has a glass transition temperature of -100 ° C. or lower and 1,2-cis-butadiene content in a microstructure composition of 96% or more. According to claim 1, wherein the carbon black has a colloidal property of CTAB of 110 to 130 m 2 / g, C-DBP of 95ml / 100g or more, toluene decolorization (@ 342μm) of 30 or less, TINT of 115 or more, N2SA 110 To 145 m 2 / g, STSA is 100 to 136 m 2 / g, N2SA / STSA is 1.05 to 1.2, N2SA-STSA is 6 to 30 rubber composition for tire tread.