JP2004010746A - Rubber composition and tire using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce rolling resistance without extremely decreasing abrasion resistance of a tire. <P>SOLUTION: The rubber composition comprises (A) 100 pts. wt. rubber component, (B) 0.5-3 pts. wt. alkyl phenol disulfide resin and (C) a reinforcing material comprising silica and/or carbon black. The content of the carbon black in the silica and/or the carbon black of the reinforcing material (C) is ≥55 wt.%. The tire comprises the rubber composition. The rubber composition preferably contains (D) N,N'-bis(2-methyl-2-nitropropyl)-1,6-hexamethylenediamine besides them. <P>COPYRIGHT: (C)2004,JPO

Description

【００４６】
【表２】

【００４７】
【発明の効果】
本発明によれば、タイヤのトレッド部分に、アルキルフェノールジスルフィドレジンおよび特定割合のカーボンブラックを含む補強剤をそれぞれ特定量配合したゴム組成物を採用することにより、タイヤの耐摩耗性を大幅に低下させることなく、低転がり抵抗化（ＬＲＲ化）が図れる。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a rubber composition, and more particularly, to a rubber composition capable of realizing low fuel consumption without significantly lowering wear resistance, and a tire comprising the rubber composition.
[0002]
[Prior art]
In recent years, social demands for lower fuel consumption of automobiles have increased, and the development of low fuel consumption technology (PCR) for reducing the rolling resistance of tires has been actively performed. In order to reduce the rolling resistance, it is general to reduce the hysteresis loss of the rubber composition for a tread.
[0003]
As a technique, for a rubber composition for a tread, for example,
1) a method of controlling the microstructure of the polymer using solution-polymerized SBR or vinyl polyisoprene 2) a method of using an incompatible polymer 3) a method of using a silane coupling agent in combination with silica as a reinforcing agent (polymer / A silane coupling agent has been employed as a method for improving the interaction between fillers.)
4) Method of reducing the amount of carbon black as a reinforcing agent 5) Low rolling resistance (LRR) has been achieved by techniques such as a method of compounding a polymer compatibilizer.
[0004]
In particular, use of the silane coupling agent of 3) is employed.
[0005]
However, further reduction in rolling resistance is desired from the viewpoint of reducing the load on the environment. However, it is not preferable that the wear resistance is impaired.
[0006]
[Problems to be solved by the invention]
An object of the present invention is to provide a rubber composition having reduced rolling resistance without significantly lowering wear resistance, and a tire comprising the rubber composition.
[0007]
[Means for Solving the Problems]
As a result of studying to solve the above problem, it was found that the above problem can be solved by blending an alkylphenol disulfide resin with a rubber composition in which carbon black is a main reinforcing agent, and the present invention has been completed. .
[0008]
That is, the present invention comprises (A) 100 parts by weight of a rubber component, (B) 0.5 to 3 parts by weight of an alkylphenol disulfide resin, and (C) a reinforcing agent comprising silica and / or carbon black. It relates to a rubber composition in which 55% by weight or more of the agent (C) is carbon black.
[0009]
The rubber composition further comprises (D) N, N'-bis (2-methyl-2-nitropropyl) -1,6-hexanediamine 0.3 to 1.100 parts by weight based on 100 parts by weight of the rubber component (A). It is preferable to contain 0 parts by weight.
[0010]
Further, the present invention relates to a tire comprising the rubber composition.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
The rubber composition of the present invention comprises (A) a rubber component, (B) an alkylphenol disulfide resin, and (C) a reinforcing agent.
[0012]
The rubber component (A) is not particularly limited as long as it has been conventionally used for a tread of a tire. For example, diene such as styrene-butadiene rubber (SBR), butadiene rubber (BR), and isoprene rubber (IR) The system rubber and the natural rubber (NR) can be used alone or in any combination.
[0013]
Examples of the alkylphenol disulfide resin (B) include Suncellar AP manufactured by Sanshin Chemical Industry Co., Ltd.
[0014]
The compounding amount of the alkylphenol disulfide resin (B) is 0.5 to 3 parts by weight, preferably 1 to 3 parts by weight, more preferably 1 to 2.5 parts by weight based on 100 parts by weight of the rubber component (A). is there. When the amount of the alkylphenol disulfide resin is less than 0.5 part by weight, LRR formation is not observed, and when the amount exceeds 3 parts by weight, abrasion resistance is significantly reduced.
[0015]
The reinforcing agent (C) consists of silica and / or carbon black, and 55% by weight or more consists of carbon black. The proportion of carbon black is preferably 55 to 95% by weight, more preferably 60 to 90% by weight. If the ratio of carbon black is less than 55% by weight, the amount of silica increases, resulting in an increase in cost. On the other hand, when the proportion of carbon black exceeds 95% by weight, heat generation becomes high, and there is a tendency that LRR cannot be achieved. Further, the rubber composition of the present invention has a higher abrasion resistance than the rubber composition using a reinforcing agent having a high silica compounding ratio by using the reinforcing agent (C) having a high compounding ratio of carbon black. ing.
[0016]
The type of the silica is not particularly limited, and for example, dry process silica (silicic anhydride), wet process silica (hydrous silicate) and the like can be used. Preferable examples of the wet process silica include Ultrasil VN3 (trade name) manufactured by Degussa, and Nipsil VN3 (trade name) manufactured by Nippon Silica Industry Co., Ltd.
[0017]
The type of the carbon black is not particularly limited, and examples thereof include HAF, ISAF, and SAF.
[0018]
The compounding amount of the reinforcing agent (C) is preferably 30 to 80 parts by weight, more preferably 40 to 65 parts by weight, based on 100 parts by weight of the rubber component (A). If the amount of the reinforcing agent is less than 30 parts by weight, the reinforcing effect tends to be small, and the abrasion resistance tends to decrease. If the amount exceeds 80 parts by weight, the heat generation becomes high, and the LRR tends not to be formed.
[0019]
The rubber composition of the present invention further comprises (D) N, N'-bis (2-methyl-2-nitropropyl) in addition to the rubber component (A), the alkylphenol disulfide resin (B), and the reinforcing agent (C). ) It is preferable to mix -1,6-hexanediamine.
[0020]
N, N'-bis (2-methyl-2-nitropropyl) -1,6-hexanediamine (D) is added in an amount of 0.3 to 1.0 part by weight based on 100 parts by weight of the rubber component (A). Is preferred. If the amount of N, N'-bis (2-methyl-2-nitropropyl) -1,6-hexanediamine (D) is less than 0.3 part by weight, the effect of reducing tan δ is insufficient and exceeds 1 part by weight. And the hardness of rubber tends to increase remarkably, and the fatigue resistance tends to decrease significantly.
[0021]
In the present invention, the reduction of the abrasion resistance is within an allowable range or hardly reduced by blending the alkylphenol disulfide resin (B) with the rubber composition comprising carbon black as the main reinforcing agent system, It is possible to greatly improve tan δ, which is an index of the rolling resistance. Further, by simultaneously using the alkylphenol disulfide resin (B) and N, N'-bis (2-methyl-2-nitropropyl) -1,6-hexanediamine (D), LRR and abrasion resistance are further improved. Can improve.
[0022]
When N, N'-bis (2-methyl-2-nitropropyl) -1,6-hexanediamine is used alone in a rubber composition containing carbon black as a main reinforcing agent, rolling occurs. The effect of reducing the resistance is very small.
[0023]
In addition, in addition to silica and carbon black, for example, clay, calcium carbonate, and the like can be added to the rubber composition of the present invention as a reinforcing agent.
[0024]
The rubber composition of the present invention may contain a silane coupling agent in combination with the silica.
[0025]
Examples of the silane coupling agent include bis (3-triethoxysilylpropyl) tetrasulfide, bis (triethoxysilylpropyl) disulfide, triethoxysilylpropylisocyanate, vinyltriethoxysilane, vinyltrimethoxysilane, and γ-methacryloxypropyl. Trimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-mercaptopropyltrimethoxysilane, γ- (polyethyleneamino) -propyltrimethoxysilane, N-β- (amino Ethyl) -γ-aminopropyltrimethoxysilane, N′-vinylbenzyl-N-trimethoxysilylpropylethylenediamine salt and the like. These may be used alone or in combination of two or more. Among these, bis (3-triethoxysilylpropyl) tetrasulfide and the like are preferable from the viewpoint of achieving both the effect of adding the coupling agent and the cost.
[0026]
The compounding amount of the silane coupling agent is preferably 3 to 15% by weight, more preferably 5 to 10% by weight of the compounding amount of the silica. If the compounding amount of the silane coupling agent is less than 3% by weight, the bond between silica and rubber is weakened, the calorific value increases, and tan δ increases. The cost tends to be high just by adding the ring agent in excess.
[0027]
The rubber composition of the present invention includes a rubber component (A), an alkylphenol disulfide resin (B), a reinforcing agent (C), N, N'-bis (2-methyl-2-nitropropyl) -1,6-hexane. In addition to diamine (D), other reinforcing agents, silane coupling agents, compounding agents usually used as rubber compositions, for example, wax, antioxidant, stearic acid, zinc oxide, extender oil, vulcanizing agent, A vulcanization accelerator or the like can be appropriately compounded.
[0028]
The rubber composition of the present invention comprises the rubber component, alkylphenol disulfide resin, N, N'-bis (2-methyl-2-nitropropyl) -1,6-hexanediamine, silica and / or carbon black, and if necessary. The other compounding agents can be obtained by kneading using a usual processing device, for example, a roll, a Banbury mixer, a kneader or the like.
[0029]
The tire of the present invention is produced by a usual method using the rubber composition, particularly for a tread of a tire. That is, the rubber composition is extruded into a shape of a tread portion of a tire at an unvulcanized stage, and is bonded by an ordinary method on a tire molding machine to form an unvulcanized tire. The unvulcanized tire is heated and pressed in a vulcanizer to obtain a tire. The tire thus obtained has a reduced rolling resistance without drastically reducing the wear resistance.
[0030]
【Example】
Next, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. In the examples and comparative examples, the following materials were used.
[0031]
Natural rubber: RSS # 3
IR: IR2200 manufactured by Zeon Corporation
BR: BR150B manufactured by Ube Industries, Ltd.
SBR: Solution polymerization SBR manufactured by Sumitomo Chemical Co., Ltd.
Silica: Nipsil VN3 manufactured by Nippon Silica Industry Co., Ltd.
Silane coupling agent: Si69 manufactured by Degussa
(Bis (3-triethoxysilylpropyl) tetrasulfide)
Carbon black ISAF: N220 manufactured by Mitsubishi Chemical Corporation
Wax: Sannoc N manufactured by Ouchi Shinko Chemical Industry Co., Ltd.
Anti-aging agent 6C: Nocrack 6C manufactured by Ouchi Shinko Chemical Industry Co., Ltd.
Stearic acid: Zinc oxide manufactured by NOF Corporation: Sulfur manufactured by Toho Zinc Co., Ltd .: Sulfur vulcanization accelerator NS manufactured by Tsurumi Chemical Industry Co., Ltd. NS: Noxeller NS-P manufactured by Ouchi Shinko Chemical Co., Ltd.
N, N'-bis (2-methyl-2-nitropropyl) -1,6-hexanediamine: Sumifine 1162S (N, N'-bis (2-methyl-2-nitropropyl) manufactured by Sumitomo Chemical Co., Ltd. ) 33% by weight of -1,6-hexanediamine and 67% by weight of calcined clay)
Alkylphenol disulfide resin: Suncellar AP manufactured by Sanshin Chemical Industry Co., Ltd.
[0032]
Examples 1-3 and Comparative Examples 1-2
(Processing method)
According to the mixing ratio in Table 1, components other than sulfur and the vulcanization accelerator were mixed at 160 ° C. for 3.5 minutes using a Banbury internal mixer, and the sulfur and vulcanization accelerator were opened in the obtained master batch. It was added on a roll and kneaded at 85 to 90 ° C. for 3 minutes to obtain a rubber composition. Next, the obtained rubber composition was vulcanized at 150 ° C. for 35 minutes.
[0033]
Using the vulcanized rubber compositions of Examples 1 to 3 and Comparative Examples 1 and 2, evaluation tests of the following properties were performed.
[0034]
(Loss tangent)
As the test piece, a slab sheet having a thickness of 2 mm and a width of 4 mm was used, the distance between sample sandwiches was 2 cm, and the initial elongation was 10%. Using a viscoelastic spectrometer manufactured by Iwamoto Seisakusho, the loss tangent (tan δ) was measured under the conditions of a tensile dynamic strain of 2%, a frequency of 10 Hz and 70 ° C., and an index using Comparative Example 1 as a reference value (100). Indicated by. The smaller this index is, the lower the rolling resistance is, and the more excellent it is.
[0035]
(Wear resistance)
Each rubber composition vulcanized using a Lambourn abrasion tester manufactured by Iwamoto Seisakusho under the conditions of a surface rotation speed of 50 m / min, a load of 2.5 kgf, a falling sand amount of 16.0 g / min, and a slip ratio of 40%. The weight loss of the object was measured. The reciprocal of this measured value was determined and indicated by an index using Comparative Example 1 as a reference value (100). The larger the index, the better the wear resistance.
[0036]
Table 1 shows the results.
[0037]
Examples 4 to 10 and Comparative Examples 3 to 6
(Processing method)
A vulcanized rubber composition was obtained in the same manner as in Examples 1 to 3 and Comparative Examples 1 and 2, except that the contents and the proportions in Table 2 were used.
[0038]
Using the obtained vulcanized rubber composition, the same evaluation test as in Examples 1 to 3 and Comparative Examples 1 and 2 was performed. As the index of the physical property value, the physical property value of Comparative Example 3 was used as a reference value (100).
[0039]
Table 2 shows the results.
[0040]
As shown in Table 1, the rolling resistance (tan δ) of Examples 1 to 3 in which a prescribed amount of alkylphenol disulfide resin was blended in the reinforcing rubber composition mainly composed of carbon black was higher than that of Comparative Example 1 in which the compound was not blended. Index ratio) has been greatly reduced. The reduction in wear resistance was within an allowable range.
[0041]
In Comparative Example 2 in which the alkylphenol disulfide resin was added in an amount exceeding the specified amount, although the rolling resistance (tan δ index ratio) was greatly reduced, the abrasion resistance was lowered beyond the allowable range.
[0042]
Also, in Table 2, Examples 4 to 10 in which a prescribed amount of alkylphenol disulfide resin was blended in the reinforcing rubber composition mainly composed of carbon black, compared to Comparative Example 3 in which the compound was not blended. The resistance (tan δ index ratio) was greatly reduced. The reduction in wear resistance was within an allowable range. Further, in Examples 4 to 9 in which N, N'-bis (2-methyl-2-nitropropyl) -1,6-hexanediamine was blended, the rolling resistance (tan δ index ratio) was further reduced.
[0043]
On the other hand, in Comparative Examples 4 and 5, in which the alkylphenol disulfide resin was added in an amount exceeding the specified amount, the rolling resistance (tan δ index ratio) was reduced, but the abrasion resistance was lowered beyond the allowable range.
[0044]
In Comparative Example 6, in which only N, N'-bis (2-methyl-2-nitropropyl) -1,6-hexanediamine was added, the rolling resistance (tan δ index ratio) did not decrease.
[0045]
[Table 1]

[0046]
[Table 2]

[0047]
【The invention's effect】
According to the present invention, the wear resistance of the tire is significantly reduced by employing a rubber composition in which a specific amount of a reinforcing agent containing an alkylphenol disulfide resin and a specific ratio of carbon black is blended in the tread portion of the tire. Without this, low rolling resistance (LRR) can be achieved.

Claims (3)

(B) 0.5 to 3 parts by weight of an alkylphenol disulfide resin and (C) a reinforcing agent composed of silica and / or carbon black with respect to 100 parts by weight of the rubber component. A rubber composition in which at least% by weight is carbon black. Further, (D) 0.3 to 1.0 part by weight of N, N'-bis (2-methyl-2-nitropropyl) -1,6-hexanediamine is contained based on 100 parts by weight of the rubber component (A). The rubber composition according to claim 1. A tire comprising the rubber composition according to claim 1.