JP2010248338A - Rubber composition and tire using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubber composition capable of improving the grip performance of a tire while suppressing the reduction of abrasion resistance by softening when used as a tread rubber of the tire, and to provide the tire using the rubber composition, and having high grip performance and moderate abrasion resistance. <P>SOLUTION: The rubber composition is obtained by compounding a plasticizer of 50-210 pts.mass with a rubber component of 100 pts.mass. 1-20 pts.mass of the compounded plasticizer is composed of a fatty acid metal salt. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rubber composition and a tire using the rubber composition, and in particular, a rubber capable of improving the grip of the tire and suppressing a decrease in wear resistance when used in a tread portion of the tire. The present invention relates to a composition and a tire using the rubber composition.

  Conventionally, as a rubber composition for tire treads used in low fuel consumption tires with reduced rolling resistance, the viscosity of unvulcanized rubber is lowered to improve processability, and the rolling resistance of vulcanized rubber is reduced and the wear resistance is improved. Therefore, a rubber composition is known in which 1 to 10 parts by weight of a processing aid composed of a fatty acid zinc salt is blended with 100 parts by weight of a diene rubber (for example, see Patent Document 1).

  However, in the fuel-efficient tire using the rubber composition as described above, although the rolling resistance can be reduced, there is a fear that sufficient grip force cannot be obtained as the rolling resistance is reduced.

  Therefore, in order to obtain a tire having sufficient grip performance, a tire using a soft rubber made of a rubber composition in which an oil such as spindle oil, aroma oil, liquid oil or the like is blended as a plasticizer with a rubber component is used for the tread portion. Attempts have been made to improve grip performance.

JP-A-6-248114

  However, when the rubber composition containing the conventional plasticizer (oil) as described above is used for the tread portion, the tread rubber is softened by adding a large amount of plasticizer (reducing the modulus of the vulcanized rubber). However, although it is possible to improve the grip performance of the tire, there has been a problem that the wear resistance of the tire is greatly lowered due to the softening of the tread rubber.

  For this reason, there has been a demand for a rubber composition that can improve the grip performance of a tire while suppressing a reduction in wear resistance due to softening when used in a tread portion of a tire. There has also been a demand for a tire using the rubber composition that has high grip performance and constant wear resistance.

  As a result of intensive studies to solve the above problems, the present inventor has improved the grip performance of the tire by obtaining the same modulus reduction effect of vulcanized rubber as that of a conventional plasticizer when blended with a rubber component. As a substance capable of reducing the decrease in breaking strength (TB) as compared with the case where a conventional plasticizer is added, a fatty acid metal salt has been found. Then, a part of the plasticizer (oil) conventionally blended with the rubber component is replaced with the fatty acid metal salt, and a predetermined amount of the fatty acid metal salt and the conventional plasticizer are blended with the rubber component to obtain a rubber composition. As a result, the present invention has been completed.

  That is, the rubber composition of the present invention is a rubber composition in which 50 to 210 parts by mass of a plasticizer is blended with 100 parts by mass of a rubber component, and 1 to 20 parts by mass of the plasticizer is a fatty acid metal salt. It is characterized by comprising. In this way, by using a fatty acid metal salt as a part of the plasticizer to be blended, achieving both improvement in tire grip performance and suppression of wear resistance reduction when used in the tread portion of the tire Thus, it is possible to obtain a rubber composition capable of suppressing the decrease in wear resistance while obtaining the effect of reducing the modulus of vulcanized rubber. In addition, when the compounding amount of the plasticizer with respect to 100 parts by mass of the rubber component is less than 50 parts by mass, the effect of reducing the modulus of the vulcanized rubber is not sufficient, and when it exceeds 210 parts by mass, the wear resistance decreases. As it passes, rolling resistance becomes too large. Moreover, when the amount of the fatty acid metal salt in the plasticizer is less than 1 part by mass, the effect of suppressing the reduction in wear resistance is small.

  In the rubber composition of the present invention, 11 to 20 parts by mass of the plasticizer is preferably composed of a fatty acid metal salt.

  Here, in the rubber composition of the present invention, at least 70% by mass of the rubber component is preferably composed of a styrene-butadiene copolymer rubber having a styrene content of 20 to 60% by mass, preferably 31 to 60% by mass. . By using at least 70% by mass of the rubber component as a styrene-butadiene copolymer rubber (SBR) having a styrene content of 20 to 60% by mass, the modulus of the vulcanized rubber is further reduced and the wear resistance is reduced. A more suppressed rubber composition can be provided. Here, when the amount of SBR in the rubber component is less than 70% by mass, the characteristics of SBR cannot be exhibited sufficiently. Further, when the styrene content is less than 20% by mass, a sufficient modulus reduction effect cannot be obtained, and when it exceeds 60% by mass, the rolling resistance becomes too large. The SBR in the rubber component may be composed of only one type of SBR, or may be composed of a mixture of a plurality of types of SBR having different styrene contents.

  In the rubber composition of the present invention, the vinyl content of the butadiene portion of the styrene-butadiene copolymer rubber is preferably 30 to 60% by mass. This is because when the vinyl content of the butadiene portion is less than 30% by mass, a sufficient modulus reduction effect cannot be obtained, and when it exceeds 60% by mass, the rolling resistance becomes too large. .

  The rubber composition of the present invention preferably contains 60 to 200 parts by mass of carbon black with respect to 100 parts by mass of the rubber component.

  The tire of the present invention is characterized in that at least a tread portion is composed of the above rubber composition. Thus, by constituting the tread portion of the tire with the rubber composition, a tire with high grip performance can be obtained without significantly reducing the wear resistance. In addition, as a tire which comprises a tread part with the said rubber composition, the high performance tire containing a racing tire is especially preferable.

  According to the present invention, by using a fatty acid metal salt instead of a part of a conventional plasticizer, it is possible to obtain a modulus reduction effect of vulcanized rubber and improve grip properties when used in a tread portion of a tire. It is possible to provide a rubber composition that is capable of suppressing wear resistance reduction. Moreover, the tire which improved the grip performance can be provided using the said rubber composition, without reducing abrasion resistance significantly.

It is sectional drawing of an example of the tire of this invention.

<Rubber composition>
Below, the rubber composition of this invention is demonstrated in detail. The rubber composition according to the present invention is a rubber composition in which 50 to 210 parts by mass of a plasticizer is blended with 100 parts by mass of a rubber component, and 1 to 20 parts by mass of the plasticizer is composed of a fatty acid metal salt. It is characterized by suppressing the decrease in wear resistance while obtaining the effect of reducing the modulus of vulcanized rubber.

  Here, the rubber component is composed of natural rubber (NR), synthetic rubber, or a mixture thereof. Specific examples of the synthetic rubber include styrene-butadiene copolymer rubber (SBR), polyisoprene rubber (IR). ), Polybutadiene rubber (BR), polychloroprene rubber (CR), isoprene-isobutylene copolymer rubber (IIR), acrylonitrile-butadiene copolymer rubber (NBR), and ethylene-propylene copolymer rubber (EPDM).

  The rubber component is composed of a styrene-butadiene copolymer rubber (SBR) having at least 70% by mass, a styrene content of 20 to 60% by mass, and a vinyl content of the butadiene portion of 30 to 60% by mass. It is preferable.

  Examples of the plasticizer blended with the rubber component include conventional plasticizers such as spindle oil, aroma oil, liquid oil, or mixtures thereof, and fatty acid metal salts. And it is preferable that 1-20 mass parts is a fatty acid metal salt among the plasticizer mix | blended in the ratio of 50-210 mass parts with respect to 100 mass parts of rubber components, and 11-20 mass parts is fatty acid metal salt. More preferably.

  Here, as the fatty acid metal salt, a metal salt of a saturated fatty acid, a metal salt of an unsaturated fatty acid, or a mixture thereof can be used. Specifically, fatty acid metal salts include saturated fatty acids such as palmitic acid, stearic acid, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, arachidic acid, behenic acid, serotic acid, montanic acid, and melicic acid. Or metal salts of zomarinic acid, petroceric acid, oleic acid, erucic acid, whale oil acid, linoleic acid, eleostearic acid, moloctic acid, valinalic acid, sardine acid, hiragasiraic acid, nisinic acid, ricinoleic acid, lauroleic acid, Examples thereof include metal salts of unsaturated fatty acids such as elaidic acid, erucic acid, linoelaidic acid, linolenic acid and arachidonic acid. And as a metal element which forms a metal salt with the saturated fatty acid or unsaturated fatty acid mentioned above, zinc etc. are mentioned.

  Further, in the rubber composition of the present invention, 60 to 200 parts by mass of carbon black, particularly SAF, ISAF, and HAF grade carbon black may be blended as a reinforcing filler with respect to 100 parts by mass of the rubber component. good. Moreover, you may mix | blend normally used compounding agents, such as a vulcanizing agent, a vulcanization accelerator, a filler, an anti-aging agent, with the rubber composition of this invention suitably.

  The rubber composition of the present invention is not particularly limited except that the plasticizer is blended with the rubber component in the above blending amount. For example, the rubber composition can be produced as follows.

  The plasticizer containing the fatty acid metal salt is blended with a rubber component together with an optional filler (carbon black or the like) and an additive and kneaded. The method for preparing the rubber composition of the present invention is not particularly limited. For example, using a Banbury mixer, a roll or the like, a rubber component is kneaded with a plasticizer and various compounding agents appropriately selected as necessary. Can be prepared.

<Tire>
The tire of the present invention is characterized in that at least a part thereof is composed of the rubber composition, and other than that, it can be manufactured using the same manufacturing method as that of a normal tire.

  Next, the tire of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of an example of the tire of the present invention. The tire shown in FIG. 1 has a pair of bead portions 1, a pair of sidewall portions 2, and a tread portion 3 connected to both sidewall portions 2, and extends in a toroid shape between the pair of bead portions 1. The carcass 4 that reinforces the parts 1, 2, and 3 and the belt 5 that is located on the outer side in the tire radial direction of the crown portion of the carcass 4 are provided.

  In the illustrated tire, the carcass 4 is composed of a single carcass ply, and a main body portion extending in a toroid shape between a pair of bead cores (wires) 6 disposed in the bead portion 1, and each bead core 6. And a folded portion wound up radially outward from the inner side to the outer side in the tire width direction. In the illustrated example, the carcass 4 is composed of one carcass ply. However, in the tire of the present invention, a plurality of carcass plies may be provided.

  In the illustrated tire, the belt 5 is composed of two belt layers. However, in the tire of the present invention, the number of belt layers constituting the belt may be one or more, and is not limited thereto. Absent. Furthermore, the tire of the present invention may further include a belt reinforcing layer made of a rubberized layer of cords arranged substantially parallel to the tire circumferential direction on the outer side in the tire radial direction of the belt 5. Further, an interlayer rubber can be provided between the belt reinforcing layer and the belt reinforcing layer.

  And the tire of the example of illustration uses the rubber composition mentioned above for the tread part 3 at least.

  In addition, as gas with which the tire of the present invention is filled, an inert gas such as nitrogen, argon, helium, etc. can be used in addition to air having normal or oxygen partial pressure adjusted.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.

(Examples 1-6)
A rubber composition having a formulation shown in Table 1 was prepared according to a conventional method. And the tire (size: 225/40 R18) for passenger cars which used the produced rubber composition as a tread rubber was produced by the normal method. The produced tire was measured and evaluated for grip properties and wear resistance by the following methods. The results are shown in Table 1.

(Examples 7 to 12)
A rubber composition having the formulation shown in Table 2 was prepared in the same manner as in Examples 1 to 6 except that the blending amounts of carbon black and aroma oil were changed. And the tire for passenger cars was produced similarly to Examples 1-6, and grip property and abrasion resistance were evaluated. The results are shown in Table 2.

(Examples 13 to 18)
A rubber composition having the formulation shown in Table 3 was prepared in the same manner as in Examples 1 to 6 except that the blending amounts of carbon black and aroma oil were changed. And the tire for passenger cars was produced similarly to Examples 1-6, and grip property and abrasion resistance were evaluated. The results are shown in Table 3.

(Comparative Examples 1-12)
Except not using fatty acid zinc salt as a plasticizer, it carried out similarly to Examples 1-18, and produced the rubber composition of the mixing | blending prescription shown in Tables 1-3. And the tire for passenger cars was created like Examples 1-18, and grip property and abrasion resistance were evaluated. The results are shown in Tables 1-3.

(Grip property)
The tires were mounted on a high-performance vehicle capable of traveling at a maximum speed of 300 km / h, and the high-performance vehicle was driven 20 laps on the circuit to measure time. And the average time of measured 20Lap is calculated, and the result is Comparative Example 1 for Examples 1 to 6 and Comparative Examples 2 to 4, and Comparative Example 5 for Examples 7 to 12 and Comparative Examples 6 to 8. In Examples 13 to 18 and Comparative Examples 10 to 12, Comparative Example 9 was indexed as 100 and evaluated in five stages. A positive (+) value means faster time and better tire grip.

(Abrasion resistance)
The tire produced was mounted on a high performance vehicle capable of traveling at a maximum speed of 300 km / h, and the high performance vehicle was allowed to travel 20 laps on the circuit. And the remaining groove | channel of the tread part of the tire after 20 Lap was measured with the depth gauge, the result was compared with Example 1 about Examples 1-6 and Comparative Examples 2-4, Examples 7-12 and Comparative Examples 6-8. The comparative example 5 was indexed, and the comparative examples 9 to 100 were indexed as Comparative Example 5 and Comparative Examples 9 to 100 as 100, and the wear depth was evaluated in five stages. A positive (+) value indicates less wear and higher tire wear resistance.

1) Styrene-butadiene rubber (E-SBR, manufactured by JSR Corporation, 1712): Oil-extended with 37.5 parts by mass of aroma oil based on 100 parts by mass of rubber component, containing 23.5% by mass of styrene
2) Toast Carbon Co., Ltd., Seast 9H (nitrogen adsorption specific surface area (N ₂ SA): 142 m ² / g, dibutyl phthalate oil absorption: 130 ml / 100 g)
3) A / O MIX made by Sankyo Oil Chemical Co., Ltd.
4) Super Oil Y22 made by Nippon Oil Corporation
5) RICON100, manufactured by SARTOMER
6) STRILLTOL VP1405, manufactured by SCHILL & SEILACHER
7) Activ Blast PP, manufactured by RHEIN CHEMIE
8) Microcrystalline wax manufactured by Seiko Chemical Co., Ltd.
9) N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine, manufactured by Ouchi Shinsei Chemical Co., Ltd.
10) Bis (4-methyldibenzothiazolyl-2) -disulfide, manufactured by Sanshin Chemical Industry Co., Ltd.

  From Examples 1 to 18 and Comparative Examples 1 to 12 in Tables 1 to 3, by using a rubber composition containing a fatty acid zinc salt instead of a conventional plasticizer (spindle oil, liquid oil, etc.) as a tread rubber, It has been found that it is possible to provide a tire that improves the grip and suppresses the reduction in wear resistance.

1 Bead part 2 Side wall part 3 Tread part 4 Carcass 5 Belt 6 Bead core

Claims (6)

A rubber composition containing 50 to 210 parts by mass of a plasticizer with respect to 100 parts by mass of a rubber component,
1-20 mass parts among the said plasticizers consist of a fatty-acid metal salt, The rubber composition characterized by the above-mentioned.   2. The rubber composition according to claim 1, wherein at least 70 mass% of the rubber component is made of a styrene-butadiene copolymer rubber having a styrene content of 20 to 60 mass%.   The rubber composition according to claim 1, wherein 11 to 20 parts by mass of the plasticizer is composed of a fatty acid metal salt.   The rubber composition according to claim 2, wherein a vinyl content of a butadiene portion of the styrene-butadiene copolymer rubber is 30 to 60% by mass.   The rubber composition according to any one of claims 1 to 4, wherein 60 to 200 parts by mass of carbon black is blended with 100 parts by mass of the rubber component.   A tire comprising at least a tread portion made of the rubber composition according to any one of claims 1 to 5.

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