JP3088076B2 - Rubber composition for tire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a rubber composition for a tire.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for fuel economy in automobiles, and since the characteristics of tires have a significant effect on fuel economy, tire rubber compositions having excellent fuel economy have been developed. It is strongly desired. On the other hand, from the viewpoint of running safety, importance is placed on grip on wet road surfaces (hereinafter referred to as "wet grip").

[0003] However, it is generally necessary to reduce the hysteresis loss in order to obtain a fuel-saving tire. However, since a small hysteresis loss means a low rolling resistance, the grip force is reduced.
On the other hand, the improvement of the wet grip force is to increase the rolling resistance, but in this case, the hysteresis loss is increased and the fuel economy is deteriorated. As described above, the two have a conflicting relationship, and therefore, research and development of a rubber composition that satisfies both are proceeding.

[0004] For example, a rubber composition for tires using carbon black as a reinforcing agent is generally used. However, the general fact that the hysteresis loss increases as the amount of carbon black added increases. Attempts have been made to improve the dispersibility of carbon black by making it easier to form chemical bonds and to reduce hysteresis loss. Substances that facilitate the chemical bond between rubber molecules and carbon black are generally called chemical promoters. For example, it has been reported that the addition of a nitroso compound reduces hysteresis loss (Kenneth W. et al. Doak et al; Rubber Chem. Tec
nol, 28, 895 (1995); Payne, AR et al .; J. Rubb. Res. Inst.
aya, 22,275 (1969), Walker, LA et al .; Rubber Age 90.925
(1962), Patts.KT et al .; Rubber Chem. Tecnol, 47, 289 (197
4), Daneil F. Graves; Rubber Chem. Tecnol, 66, 61 (199
3)). According to these reports, reduction in hysteresis loss is achieved in any case, but it is described that there is a problem in crack growth resistance.

As another chemical promoter for reducing the hysteresis loss, a carbon black / rubber coupling agent based on dinitroamine has been proposed (Yamaguchi,
T. et al .; Kautschuk Gummi. Kunnst., 42, 403 (1989)). However, according to this report, dinitroamine-based carbon black / rubber coupling agents are effective for polyisoprene-based rubber, but are not particularly effective for butadiene-based rubber such as SBR (Yamaguchi , T. et al .; K
autschuk Gummi.Kunnst., 42, 403 (1989), p. 406)
.

It is well known that the use of silica (white carbon) as a rubber reinforcing agent other than carbon black and the combined use of a silane coupling agent reduce the hysteresis loss. The use of silica instead of black has the problem of reducing wear resistance.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a rubber composition which is used in a tire having excellent abrasion resistance and wet grip and high fuel efficiency.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies based on the above technical trends, and as a result, have found a coupling agent for carbon black which is effective for both polyisoprene rubber and butadiene rubber. They have found and completed the present invention. That is, the rubber composition for a tire of the present invention is a composition comprising a compound represented by the following general formula (1) and at least one of a salt thereof, a thiol-based compound, a diene-based rubber and carbon black. is there.

[0009]

Embedded image

(Wherein, R ¹ and R ² are a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and X is a hydrocarbon group having a straight-chain alkylene group.) Specific surface area is 50-2
50m ² / g, DBP oil absorption 60-150ml / 10
0 g, and 100 parts by weight of the diene rubber.
It is preferable that the amount is 0 to 150 parts by weight.

The loss coefficient at −10 ° C. (tan δ (−10
° C)) and the loss factor at 70 ° C (tanδ (70
C)) preferably satisfies the following formula: 0.03 ≦ tan δ (70 ° C.) ≦ 0.35 WIR = {tan δ (−10 ° C.) − Tan δc (−10 ° C.)} /
tan δc (−10 ° C.) RIR = {tan δc (70 ° C.) − tan δ (70 ° C.)} /
tanδc (70 ° C.) TIR = WIR + 2 × (RIR) ≧ 0.2 (where tanδc (−10 ° C.) and tanδc (7
0 ° C.) are -10 ° C. and 70 ° C. of a control rubber composition having the same composition except that the thiol-based compound was not contained.
Is tan δ. The thiol-based compound is preferably incorporated in an amount of 0.01 to 100 mmol per 100 g of the diene-based rubber.

Preferably, the diene rubber contains butadiene rubber, and the butadiene rubber accounts for at least 20% by weight of the diene rubber.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The rubber composition for a tire of the present invention comprises:
It is a composition comprising a thiol compound, a diene rubber and carbon black. The type of diene rubber used in the rubber composition of the present invention is not particularly limited, and isoprene rubbers such as natural rubber and polyisoprene rubber; polybutadiene rubber, styrene-butadiene rubber (SBR)
Any butadiene rubber can be used,
One type or two or more types can be used as needed. Among them, a diene-based rubber containing butadiene-based rubber is preferable because of good balance in terms of various processing characteristics and tire performance. When the butadiene-based rubber is at least 20% by weight or more of the diene-based rubber, it is more preferable. preferable.

The carbon black has a nitrogen adsorption specific surface area of 50 to 250 m ² / g and a DBP oil absorption of 60 to ¹
Carbon black having a characteristic of 50 ml / 100 g is preferably used. Nitrogen adsorption specific surface area is 50m ² / g
If it is less than or the DBP oil absorption is less than 60 ml / 100 g, the reinforcing property is poor. In addition, the nitrogen adsorption specific surface area is 250 m ² /
g, the dispersibility becomes poor, and the DBP oil absorption becomes 150
If the amount exceeds ml / 100 g, the viscosity is too high, and the processability is deteriorated. As carbon black, the nitrogen adsorption specific surface area is 70 to 230 m ² / g, and the DBP oil absorption is 70 to 14
Carbon black having a characteristic of 0 ml / 100 g is more preferably used.

The compounding amount of carbon black is abrasion resistance,
Considering the overall balance of various properties such as wet grip, fuel economy, durability, steering stability, workability, etc., it is preferably 20 to 150 parts by weight per 100 parts by weight of the rubber component, and preferably 25 to 80 parts by weight. More preferably, the amount is part by weight. The rubber composition of the present invention contains at least one thiol-based compound selected from the compounds represented by the following general formula (1) and salts thereof.

[0016]

Embedded image

(Wherein, R ¹ and R ² are a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and X is a hydrocarbon group having a linear alkylene group.) Specific examples of R ¹ and R ² Examples include a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, and the like. Among them, R ¹ and R ² are preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom.

X is not particularly limited as long as it is a hydrocarbon group having a linear alkylene group.
Is preferable because of excellent fuel economy and wet grip, and more preferably a linear alkylene group having 3 to 8 carbon atoms. As a thiol-based compound, a compound represented by the general formula (1)
The compound represented by can be blended as it is,
In general, thiols having such a structure may be unstable, and thus a salt obtained by reacting the compound represented by the general formula (1) with an acid such as hydrochloric acid can be used as the thiol-based compound. .

As the thiol compound, for example, 2-
Aminoethanethiol, dimethylaminoethanethiol, cysteamine, 3-aminopropanethiol, 4-
Aminobutanethiol, 5-aminopentanethiol,
6-aminohexanethiol and hydrochlorides thereof are exemplified. The amount of the thiol compound is appropriately selected. Generally, in order to satisfy the relationship of tan δ described below,
The thiol compound is added in an amount of 0.1 g per 100 g of the diene rubber.
It is preferable that the compounding amount be from 01 to 100 mmol, because the abrasion resistance and the wet grip are further improved and the fuel economy is further improved. Further, if the compounding amount is large, the scorch time tends to be short, and the processing stability may be deteriorated. Therefore, the compounding amount of the thiol compound is more preferably 0.05 to 50 with respect to 100 g of the diene rubber. Mmol, most preferably 0.1 to 30 mmol.

The rubber composition of the present invention may contain, if necessary, vulcanizing agents, vulcanization accelerators, and other reinforcing agents, fillers, softeners, and processing aids used in normal rubber compounding. And an additive such as an antioxidant. The wet grip and processing stability (scorch time) of the rubber composition of the present invention tend to deteriorate as the amount of the thiol compound is increased, but if necessary, the base rubber (diene rubber, carbon black and It is improved by heat treatment at the stage of unvulcanized rubber containing a thiol-based compound but not containing a vulcanizing agent or vulcanization accelerator, or by re-kneading the base rubber with Banbury, etc. to improve wet grip and processing stability. Will be better. The conditions of the above-mentioned heat treatment are preferably at 80 to 180 ° C. for several minutes to several hours, and more preferably at 100 to 160 ° C. for 10 to 60 minutes. The conditions for the above-mentioned re-milling are not particularly limited as long as they are similar to the conditions usually performed for the purpose of improving the dispersibility of carbon black, etc., and the kneading temperature is 80 to 180.
C. for 0.5 to 10 minutes, preferably 100 to 1
More preferably, it is 60 ° C. for 1 to 5 minutes.

The rubber composition for a tire according to the present invention is a rubber composition having the above composition. The rubber composition includes a type of rubber component, a type of thiol compound, a type of carbon black, and a type of other additives. The value of the loss coefficient (tan δ) obtained by the dynamic viscoelasticity measurement may vary depending on the kind, the compounding amount, the kneading method, the vulcanizing method and the like. The rubber composition for tires targeted by the present invention is, in particular, tanδ
Is preferably a rubber composition for a tire that satisfies certain requirements shown below.

Here, wet grip is closely related to tan δ in a low temperature range (for example, -10 to 0 ° C.), and rolling resistance is tan δ in a high temperature range (for example, 50 to 70 ° C.).
Is closely related to The higher the value of tan δ in the low temperature range, the better the wet grip, and the higher the tan δ in the high temperature range.
It is known that the smaller the value of δ, the better the fuel economy (Y. Saito's “New Polymer Development for Lo
w Rolling Resistance Tires, 1986, Kautschuk un
d Gummi Kunststoffe 39).

In the rubber composition for a tire according to the present invention, a loss coefficient at −10 ° C. (tan) is used as an index of wet grip.
δ (−10 ° C.)) and a loss coefficient of 70 ° C. (tan δ (70 ° C.)) as an index of the rolling resistance.
℃ (70 ° C.) and tan δ (70 ° C.) preferably satisfy the following formulas, since wet grip is further improved and fuel economy is further improved.

0.03 ≦ tan δ (70 ° C.) ≦ 0.35 WIR = {tan δ (−10 ° C.) − Tan δc (−10 ° C.)} /
tan δc (−10 ° C.) RIR = {tan δc (70 ° C.) − tan δ (70 ° C.)} /
tanδc (70 ° C.) TIR = WIR + 2 × (RIR) ≧ 0.2 where tanδc (−10 ° C.) and tanδc (70 ° C.)
Is a control rubber composition, that is, a rubber composition having the same composition except that no thiol compound is blended.
Tan δ at 10 ° C and 70 ° C. In general, tan δ
The value greatly depends on the type and amount of carbon black, softening agent, vulcanizing agent, etc., and these are, as described in the prior art, not only wet grip and fuel saving, but also other requirements. It is optimized in balance with various characteristics such as abrasion resistance and workability.
Therefore, in order to examine the improvement effect of the thiol-based compound, it is necessary to compare it with the control base compounded rubber composition. Also, T.I. I. R. In the formula of R. I. R. Is doubled because R.S. I. R. And the benefits obtained by improving R. I. R. Is weighted in consideration of the difficulty of improving.

The reason that tan δ (70 ° C.) is limited to the above range is that when tan δ (70 ° C.) is less than 0.03, the wear resistance becomes extremely poor, and when tan δ (70 ° C.) exceeds 0.35, the fuel economy becomes extremely poor. This is because it is not preferable. Also, T.I. I.
R. The value of is set to 0.2 or more because it is easy to confirm that the fuel economy is excellent when this technology is actually applied.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to specific embodiments. -Rubber composition No. A1 to A9- Rubber composition No. having the compounding composition (unit: phr) shown in Table 1 A1 to A9 are prepared, and each rubber composition is -10 ° C.
And tan δ at 70 ° C. were measured. I. R. , T .; I. R. , R .; I. R. Was calculated. Table 1 also shows these values. No. A1, A
Nos. 5 and A7 correspond to the control rubber composition containing no thiol compound. A9 corresponds to a comparative example in that X is a thiol compound having an aromatic nucleus and does not belong to the thiol compound according to the present invention. Others correspond to the embodiment.

The tan δ was measured using VES-FIII2 manufactured by Iwamoto Seisakusho at 10 Hz and a dynamic amplitude of ± 0.
It was measured under the condition of 25%.

[0028]

[Table 1]

* 1: ISAF (nitrogen adsorption specific surface area: 111 m)
² / g, DBP oil absorption 115 ml / 100 g) * 2: HAF (nitrogen adsorption specific surface area 76 m ² / g, DBP oil absorption 100 ml / 100 g) * 3: N-cyclohexyl-2-benzothiazolylsulfenamide * 4: N-tert-butyl-2-benzothiazolylsulfenamide For each rubber composition, a tire was prepared by changing only the tread portion and making the other components the same, and the wet grip and the fuel saving were obtained. Was measured based on the following evaluation method, and the results are shown in Table 2. [Evaluation method] Wet grip: Using a μ-S measurement vehicle equipped with a tire prepared using a rubber composition, a wet road surface was driven at a speed of 40 km / h.
, The friction coefficient (μ) was measured from when the brake was applied to lock the wheels to when the measurement vehicle stopped, and the maximum friction coefficient during this time was measured. Rubber composition N
o. The maximum friction coefficient of a tire made of another rubber composition was represented by an index, with the maximum friction coefficient of the tire made in A1 being 100. The higher the index, the better the wet grip.

Fuel saving: The tire was rotated at a speed of 80 km / h under a load of 350 kgf to measure the rolling friction coefficient. Rubber composition No. Taking the rolling friction coefficient of the tire prepared in A1 as 100, the rolling friction coefficient of a tire prepared with another rubber composition was represented by an index. The smaller the index, the smaller the rolling resistance and the better the fuel economy.

[0031]

[Table 2]

[Evaluation] As can be seen from A1 to A4, the addition of the thiol compound according to the present invention slightly increases tan δ (−10 ° C.) and the wet grip becomes the same or more, and tan δ (70 ° C.)
It can be seen that the fuel efficiency has been improved due to the reduction in

In addition, No. A1 and No. A5, by changing the type of carbon black and increasing the amount of the vulcanization-based additive (sulfur, vulcanization accelerator), tan δ
(70 ° C.) to improve fuel economy, but the wet grip is reduced. On the other hand, also in this case, it is found that the addition of the thiol-based compound can prevent a decrease in wet grip while maintaining excellent fuel economy.

Similarly, No. A5 and No. From A7,
By using natural rubber instead of SBR for the rubber component, tan δ (70 ° C.) can be reduced to improve fuel economy, but tan δ (-10 ° C.) also decreases and wet grip decreases. I understand. On the other hand, N
o. As can be seen from A8, also in this case, the tan δ (70
° C), the fuel economy is improved. In addition, No. A7-No. From the comparison of A9, even when the thiol compound was added, the value of tan δ (70 ° C.) was different depending on the type of the thiol compound, and in the thiol compound having an aromatic nucleus in the molecule (see No. A9), It is understood that the fuel economy may be lower than the case where it is not added.

As described above, the thiol-based compound having a specific structure acts as a chemical promoter for forming a bond between carbon black and especially butadiene-based rubber, and improves the dispersibility of carbon black, thereby lowering the rolling resistance. At least, it is thought that fuel economy has been achieved. -Rubber composition No. Rubber compositions No. B1 to B8 having the compounding composition (unit: phr) shown in Table 3 B1 to B8 were prepared, and each rubber composition was -10 ° C.
Tan δ at 70 ° C. and the rubber composition No. A1
To A9, and based on the measured values. I.
R. , T .; I. R. , R .; I. R. Was calculated. Table 3 also shows these values. No. B1, B3, B5, B
7 corresponds to a control rubber composition containing no thiol compound. Others correspond to the embodiment. No. B2 contains only styrene-butadiene rubber as a diene rubber,
No. B4 contains only natural rubber as a diene rubber.
In addition, No. B6 and B6 contain natural rubber and styrene-butadiene rubber as diene rubbers,
The proportion of butadiene rubber is at least 20% by weight.

[0036]

[Table 3]

* 1: N-cyclohexyl-2-benzothiazolylsulfenamide * 2: N-tert-butyl-2-benzothiazolsulfenamide * 3: Amount of thiol compound per 100 g of diene rubber (mm
ol) * 4: Sumitomo Chemical's solution-polymerized SBR (Sty 29wt%, Vy 39wt%)
Vy means a vinyl group in a butadiene unit.

* 5: Solution-polymerized SBR made by Asahi Kasei * 6 Solution-polymerized SBR made by Nippon Synthetic Rubber * 7: Solution-polymerized SBR made by Nippon Zeon * 8: Wax * 9: Antioxidant * 10: Nitrogen adsorption specific surface area is 142 m ² / g, DBP oil absorption is 116 ml / 100 g.

* 11: The specific surface area of nitrogen adsorption is 183 m ² /
g, DBP oil absorption is 120 ml / 100 g. For each rubber composition, wet grip and fuel economy were measured based on the above evaluation method, and the results are shown in Table 4.

[0040]

[Table 4]

[Evaluation] As can be seen from B1 to B8, when the tire using the rubber compound of the example is compared with the respective comparative examples, the wet grip is almost at the same level, but a significant improvement in fuel economy is recognized. -Rubber composition No. B9 to B17-Rubber compositions No. having the compounding composition (unit: phr) shown in Table 5 B9 to B17 were prepared, and -10 of each rubber composition was prepared.
C. and 70.degree. A
1 to A9 and measured based on the measured values.
I. R. , T .; I. R. , R .; I. R. Was calculated. Table 5 also shows these values. No. B9 corresponds to the control rubber composition containing no thiol-based compound. B
17 is a thiol compound in which X is an aromatic nucleus, which does not belong to the thiol compound according to the present invention; I. R. Does not satisfy the requirements of the present invention. Others correspond to the embodiment, and In B10 to B16, the amount of cysteamine hydrochloride, which is a thiol-based compound, was changed in the range of 1 to 100 mmol per 100 g of the diene-based rubber.

[0042]

[Table 5]

* 1: N-cyclohexyl-2-benzothiazolylsulfenamide * 2: N-tert-butyl-2-benzothiazolsulfenamide * 3: Amount of thiol compound per 100 g of diene rubber (mm
ol) For each rubber composition, wet grip and fuel economy were measured based on the above evaluation method, and the results are shown in Table 6.

[0044]

[Table 6]

[Evaluation] As can be seen from B9 to B17, when the tire using the rubber compound of the example and the respective comparative examples are compared, the wet grip is almost at the same level, but the improvement in fuel economy is observed. Further, even if a thiol-based compound is not included in the present invention (B17), no improvement in fuel economy is observed.

The content of cysteamine hydrochloride and T.V. I.
R. Is plotted, T.E.C. is small even when the amount of cysteamine hydrochloride, which is a thiol compound, is as small as 1 to 10 mmol. I. R. Is large and the blending amount is 10m
Up to about mol. I. R. Increases monotonically.
When the amount exceeds 10 mmol, T.V. I. R. Value gradually starts to decrease. I. R.
Is found to decrease.

Rubber composition No. C1-C7- Rubber composition No. having the compounding composition (unit: phr) shown in Table 7 C1 to C7 are prepared, and each rubber composition is −10 ° C.
Tan δ at 70 ° C. and the rubber composition No. A1
To A9, and based on the measured values. I.
R. , T .; I. R. , R .; I. R. Was calculated. Table 7 also shows these values.

The rubber composition No. In C1 to C7, the scorch time (t ₁₀ ) was measured at 130 ° C. using a Mooney viscometer (Model SMV-202) manufactured by Shimadzu Corporation. Table 7 shows the results. No. C1 corresponds to the control rubber composition containing no thiol compound and does not belong to the thiol compound according to the present invention. Others correspond to the embodiment, and N
o. In C2 to C6, the amount of cysteamine, which is a thiol compound, is set to 0.13 to 100 g per 100 g of diene rubber.
It was changed within the range of 9.07 mol.

[0049]

[Table 7]

* 1: Solution-polymerized SBR (Sty 22 wt%, Vy 57 wt%)
Vy means a vinyl group in a butadiene unit. * 2: Nitrogen adsorption specific surface area 84 m ² / g, DBP oil absorption 12
5 ml / 100 g * 3: N-tert-butyl-2-benzothiazolsulfenamide * 4: Amount of thiol compound per 100 g of diene rubber (mm
ol) For each rubber composition, wet grip and fuel economy were measured based on the above evaluation method, and the results are shown in Table 8.

[0051]

[Table 8]

[Evaluation] As can be seen from C1 to C7, when the tire using the rubber compound of the example and the comparative example are compared, the wet grip is almost at the same level, but the improvement in fuel economy is observed. The amount of cysteamine and T.I. I. R. And plotting
When the amount of cysteamine, which is a thiol-based compound, is 0.1
Even if 3 mmol, T.I. I. R. Is large, and it can be seen that even a small amount of the compound is effective. Also, T.I. I.
R. Is between 0.13 and 9.07 of cysteamine.
It increases monotonically in the range of mmol.

Further, from Table 7, it can be seen that the scorch time (t ₁₀ ) tends to be shorter when the amount of cysteamine is increased, but in this range the scorch time is relatively long and the processing stability is excellent. -Rubber composition No. C8-C14- In order to see the effect of improving wet grip and scorch time by heat treatment and re-kneading, diene rubber, carbon black, cysteamine, zinc white and stearic acid were used in each composition (unit: phr) shown in Table 9. Was subjected to heat treatment or re-kneading under the conditions shown in Table 10 to obtain a rubber composition No. C8-C14
Was prepared. The tan δ at −10 ° C. and 70 ° C. of each rubber composition was measured using the rubber composition No. A1 to A9 were measured in the same manner as described above. I. R. , T .; I.
R. , R .; I. R. Was calculated. Table 9 also shows these values.

Rubber composition No. For C8 to C14, the scorch time (t ₁₀ ) was measured at 130 ° C. using a Mooney viscometer (Model SMV-202) manufactured by Shimadzu Corporation. Table 9 shows the results. No. C8 and C9 correspond to the control rubber composition containing no thiol compound, and do not belong to the thiol compound according to the present invention. Others correspond to the embodiment, and No heat treatment or re-kneading was performed in C10, but No. In C11 to C13, heat treatment was performed on the base rubber. In C14, heat treatment was performed on the base rubber.

[0055]

[Table 9]

* 1: Solution-polymerized SBR (Sty 29 wt%, Vy 39 wt%)
Vy means a vinyl group in a butadiene unit. * 2: Nitrogen adsorption specific surface area 183m ² / g, DBP oil absorption 1
20 ml / 100 g * 3: N-cyclohexyl-2-benzothiazolylsulfenamide * 4: Amount of thiol compound per 100 g of diene rubber (mm
ol)

[0057]

[Table 10]

* 1: Heat treatment was performed in an oven set at each temperature. * 2: The temperature of the rubber when it is put into Banbury, kneaded, and discharged. For each rubber composition, wet grip and fuel economy were measured based on the above evaluation method, and the results were shown in Table 11.
Shown in

[0059]

[Table 11]

[Evaluation] No. of Table 11 As can be seen from C8 to C14, when the tire using the rubber compound of the example and the comparative example are compared, the wet grip is almost at the same level, but the improvement in fuel economy is observed. Table 1
No. 1 As can be seen from C10 to C14, when heat treatment or re-kneading is performed (Nos. C11 to C14), the wet grip does not perform heat treatment or re-kneading. C10
It can be seen from Table 9 that the scorch time is longer and the processing stability is excellent.

[0061]

The rubber composition for a tire of the present invention is a diene rubber composition (particularly a butadiene rubber composition) using carbon black as a reinforcing agent, and contains a thiol compound having a specific structure. Therefore, it is possible to obtain a tire excellent in abrasion resistance and wet grip and high in fuel efficiency.

The carbon black has a nitrogen adsorption specific surface area of 50 to 250 m ² / g and a DBP oil absorption of 60 to 15 m.
When it is 0 ml / 100 g, the reinforcing property, the dispersibility, and the workability are excellent. Further, when 20 to 150 parts by weight is blended with respect to 100 parts by weight of the diene rubber, abrasion resistance,
The overall balance of various properties such as wet grip, fuel economy, durability, handling stability, workability, etc. is good.

The loss coefficient at −10 ° C. (tan δ (−10
° C)) and the loss factor at 70 ° C (tanδ (70
When the value of (° C)) satisfies the above expression, wet grip is further improved, and fuel economy is further improved. The thiol compound is used in an amount of 0.1 g per 100 g of the diene rubber.
When the amount is from 01 to 100 mmol, the above-mentioned tan
The relationship of δ is satisfied, the wear resistance and the wet grip are further improved, and the fuel economy is further improved.

The diene rubber contains a butadiene rubber. When the butadiene rubber is at least 20% by weight or more of the diene rubber, the balance in terms of processing characteristics and tire performance is further improved. .

Continuation of front page (56) References JP-A-58-36705 (JP, A) JP-A-8-217855 (JP, A) JP-A-6-256577 (JP, A) JP-A-63-314255 (JP, A) JP-A-7-330958 (JP, A) JP-A-6-256580 (JP, A) JP-A-4-108837 (JP, A) JP-A-59-6113 (JP, A) 9-278942 (JP, A) JP-A-6-212026 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 21/00 B60C 1/00 C08K 3/04 C08K 5 / 37

Claims (5)

(57) [Claims] 1. A rubber composition for a tire comprising a compound represented by the following general formula (1) and at least one of a salt thereof, a thiol compound, a diene rubber and carbon black. Embedded image (However, in the formula, R ¹ and R ² represent a hydrogen atom or a C ¹ -C 1
The alkyl group 3 and X are a hydrocarbon group having a linear alkylene group. ) 2. The carbon black has a nitrogen adsorption specific surface area of 50-250 m ² / g and a DBP oil absorption of 60-15.
2. The rubber composition for a tire according to claim 1, wherein the rubber composition is 0 ml / 100 g and 20 to 150 parts by weight based on 100 parts by weight of the diene rubber. 3. 3. A loss coefficient at −10 ° C. (tan δ (−10
° C)) and the loss factor at 70 ° C (tanδ (70
The rubber composition for a tire according to claim 1 or 2, wherein the value of (° C) satisfies the following expression. 0.03 ≦ tan δ (70 ° C.) ≦ 0.35 WIR = {tan δ (−10 ° C.) − Tan δc (−10 ° C.)} /
tan δc (−10 ° C.) RIR = {tan δc (70 ° C.) − tan δ (70 ° C.)} /
tanδc (70 ° C.) TIR = WIR + 2 × (RIR) ≧ 0.2 (where tanδc (−10 ° C.) and tanδc (7
0 ° C.) are -10 ° C. and 70 ° C. of a control rubber composition having the same composition except that the thiol-based compound was not contained.
Is tan δ. ) 4. The rubber composition for a tire according to claim 1, wherein the thiol compound is incorporated in an amount of 0.01 to 100 mmol per 100 g of the diene rubber. 5. The rubber composition for a tire according to claim 1, wherein the diene-based rubber contains butadiene-based rubber, and the butadiene-based rubber accounts for at least 20% by weight of the diene-based rubber. .