JP5869956B2 - Rubber composition for tire - Google Patents

Description

  The present invention relates to a tire rubber composition. More specifically, the present invention improves the dispersibility of fine particle size silica in a tire rubber composition, does not increase the viscosity of unvulcanized rubber, and can improve heat generation. The present invention also relates to a rubber composition for tires that also has good processability.

With the recent social demands for energy saving, silica is often used as a filler to achieve both low heat buildup of tire rubber compositions and grip on wet roads for the purpose of saving fuel consumption in automobiles. Yes.
The silica used tends to aggregate particles due to hydrogen bonding of silanol groups, which are surface functional groups, and it is necessary to lengthen the kneading time in order to improve the dispersion of the silica in the rubber. Further, since the silica is not sufficiently dispersed in the rubber, the rubber composition has a high Mooney viscosity, and has disadvantages such as inferior processability such as extrusion. Furthermore, since the surface of the silica particles is acidic, the basic substance used as a vulcanization accelerator is adsorbed, the rubber composition is not sufficiently vulcanized, and the storage elastic modulus does not increase. Was. For this reason, there has been a demand for improvement in processability and the like in a silica-containing rubber composition.

  Conventionally, as a technique for improving processability and the like in a silica-containing rubber composition, for example, 1) weak chemical reactivity to silica as a processing aid for improving dispersion of a reinforcing silica filler in a rubber composition Technology of adding an amide compound (fatty acid amide) having a polar terminal showing a non-polar terminal showing weak chemical reactivity to an elastic polymer to a silica-blended rubber (for example, see Patent Document 1), 2) Class 3 A technique for improving the dispersibility of silica by adding an amine compound to silica-containing rubber (for example, see Patent Document 2) is known.

  However, Patent Document 1 describes that the processability is improved by adding an amide compound (fatty acid amide) having a structure different from that of the present invention to the silica-containing rubber, but the vulcanization speed is slowed down. There is a problem, and Patent Document 2 has a description that the processability is improved by adding a tertiary amine compound having a structure different from that of the present invention to the silica-blended rubber. There is a problem that scorch time is increased and rubber scorch occurs.

  On the other hand, there is known a sulfur bloom inhibitor for rubber composed of a specific alkanolamide compound, and a technique for blending this sulfur bloom inhibitor into a rubber composition (for example, see Patent Document 3). However, the present invention differs from the present invention in terms of the subject matter, usage, and technical idea.

JP 2003-533574 A (Claims, Examples, etc.) JP 2010-59272 A (Claims, Examples, etc.) JP-A-58-113235 (Claims, Examples, etc.)

  The present invention intends to solve the above-mentioned problems of the prior art and improves the dispersibility of silica, in particular, the dispersibility of fine particle size silica in a rubber composition for tires. An object of the present invention is to provide a rubber composition for a tire that does not increase the viscosity of the rubber, can improve the heat build-up, and has good processability.

  As a result of intensive investigations in view of the above-mentioned problems of the prior art, the present inventor has found that a specific fine particle size silica, a specific silica is used for at least one rubber component selected from natural rubber and / or diene synthetic rubber. The inventors have found that a rubber composition for a tire can be obtained by blending at least one monoalkanolamide, and have completed the present invention.

（２） 前記式（Ｉ）中のＲ_１は、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、イソブチル基、ｔ−ブチル基、ペンチル基、イソペンチル基、ヘキシル基、イソヘプチル基、２−エチルヘキシル基、オクチル基、ノニル基、イソノニル基、デシル基、ウンデシル基、ドデシル基、トリデシル基、又はイソトリデシル基を表し、また、Ｒ_２は、ヒドロキシアルキル基またはオキシアルキレンユニットを有するヒドロキシアルキル基であることを特徴とする上記（１）記載のタイヤ用ゴム組成物。
（３） 前記ゴム成分１００質量部に対し、上記シリカを５〜２００質量部、及び上記式（Ｉ）で表されるモノアルカノールアミドを０．５〜１５質量部配合してなることを特徴とする上記（１）又は（２）記載のタイヤ用ゴム組成物。
（４） 前記式（Ｉ）中のＲ_２は、下記式（II）で表され、Ｒ_３は炭素数１〜６のアルキレン基であり、また、ｎは１〜５となる数であることを特徴とする上記（１）〜（３）の何れか一つに記載のタイヤ用ゴム組成物。
−（Ｒ_３Ｏ）ｎ−Ｈ ………（II）
（５） 更に、シランカップリング剤を配合することを特徴とする上記（１）〜（４）の何れか一つに記載のタイヤ用ゴム組成物。
（６） シランカップリング剤の配合量が、シリカ１００質量部に対し、１〜２０質量部である上記（５）記載のタイヤ用ゴム組成物。
（７） 前記式（Ｉ）で表されるモノアルカノールアミドの配合量が、上記シリカ１００質量部に対して、０．５〜２０質量部であることを特徴とする請求項１〜６の何れか一つに記載のタイヤ用ゴム組成物。 That is, the present invention resides in the following (1) to (7).
(1) Silica having a cetyltrimethylammonium bromide (CTAB) adsorption specific surface area of 180 to 250 (m ² / g) with respect to at least one rubber component selected from natural rubber and / or diene-based synthetic rubber; A rubber composition for tires, comprising at least one monoalkanolamide represented by the following formula (I).

(2) R ₁ in the formula (I) is methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group, isopentyl group, hexyl group, isoheptyl group, 2 -Represents an ethylhexyl group, an octyl group, a nonyl group, an isononyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, or an isotridecyl group, and R ₂ represents a hydroxyalkyl group or a hydroxyalkyl group having an oxyalkylene unit. The rubber composition for a tire according to the above (1), characterized in that it exists.
(3) The rubber component is formed by blending 5 to 200 parts by mass of the silica and 0.5 to 15 parts by mass of the monoalkanolamide represented by the formula (I) with respect to 100 parts by mass of the rubber component. The tire rubber composition according to the above (1) or (2).
(4) R ₂ in the formula (I) is represented by the following formula (II), R ₃ is an alkylene group having 1 to 6 carbon atoms, and n is a number of 1 to 5. The rubber composition for tires according to any one of the above (1) to (3), wherein
_{- (R 3 O) n-} H ......... (II)
(5) The rubber composition for tires according to any one of the above (1) to (4), further comprising a silane coupling agent.
(6) The tire rubber composition according to (5), wherein the amount of the silane coupling agent is 1 to 20 parts by mass with respect to 100 parts by mass of silica.
(7) The amount of the monoalkanolamide represented by the formula (I) is 0.5 to 20 parts by mass with respect to 100 parts by mass of the silica. The tire rubber composition according to claim 1.

  According to the present invention, the dispersibility of the fine particle size silica in the tire rubber composition is improved, the viscosity of the unvulcanized rubber is not increased, the heat generation can be improved, and the workability is improved. A rubber composition is provided.

Hereinafter, embodiments of the present invention will be described in detail.
The rubber composition for tires of the present invention has a cetyltrimethylammonium bromide (CTAB) adsorption specific surface area of 180 to 250 (m ² / m) with respect to at least one rubber component selected from natural rubber and / or diene synthetic rubber. It is characterized by blending silica as g) and at least one monoalkanolamide represented by the following formula (I).

  The rubber component used in the rubber composition for tires of the present invention comprises natural rubber and / or a diene synthetic rubber. Here, examples of the diene-based synthetic rubber include polyisoprene rubber (IR), polybutadiene rubber (BR), styrene-butadiene copolymer rubber (SBR), butyl rubber (IIR), and ethylene-propylene copolymer. It is done. These rubber components may be used alone or in a blend of two or more.

Silica used in the rubber composition for tires of the present invention needs to have a cetyltrimethylammonium bromide (CTAB) adsorption specific surface area of 180 to 250 (m ² / g).
The fine particle size silica having CATB in the above range is greatly improved in dispersibility in the rubber component by the combination with the monoalkanolamide represented by the above formula (I) of the present invention. Further, the viscosity of the unvulcanized rubber is not increased, the exothermic property can be improved, and the workability can be highly compatible.

In the present invention, the cetyltrimethylammonium bromide adsorption specific surface area (CTAB) is the specific surface area (m ² / g) of silica (hydrous silicic acid) calculated from the amount of cetyltrimethylammonium bromide adsorbed on the silica (hydrous silicic acid) surface. is there.
Moreover, the measurement of CTAB can be performed in accordance with the method described in ASTM D3765-92. Since the method described in ASTM D3765-92 is a method for measuring CTAB of carbon black, it is slightly modified. That is, a standard solution of cetyltrimethylammonium bromide (hereinafter abbreviated as CE-TRAB) is prepared without using a carbon black standard product, and thereby a hydrous silicate OT (sodium di-2-ethylhexylsulfosuccinate) solution is prepared. The specific surface area is calculated from the adsorption amount of CE-TRAB, assuming that the adsorption cross-sectional area per molecule of CE-TRAB on the hydrous silicate surface is 0.35 nm ² .

The fine particle size silica (hydrous silicic acid) used in the present invention has a CTAB of 180 to 250 (m ² / g). If this CTAB is 180 (m ² / g) or more, it is preferable from the viewpoint of expressing the effects of the present invention, and if it is 250 (m ² / g) or less, it is preferable from the viewpoint of workability and workability.

The fine particle size silica having the above characteristics is produced according to the method for producing hydrous silicic acid by precipitation method. For example, sodium silicate and sulfuric acid are placed in a reaction vessel in which a certain amount of warm water is previously filled while controlling pH and temperature, and a hydrous silicate slurry is obtained after a certain period of time.
Subsequently, the hydrated silicate slurry is filtered and washed by a filter capable of cake washing such as a filter press to remove the by-product electrolyte, and then the obtained hydrated silicate cake is slurried, and a spray dryer or the like It is dried and manufactured using a dryer.
Further, the characteristic ^{[CTAB: 180~250 (m 2 / g} ) A commercially available product having, for example, Zeosil Premium 200MP ^{[CTAB: 200 (m 2 / g} ) ], the Zeosil HRS 1200MP [CTAB: 195 (m ² / G)] and the like.
These silicas may be used alone or in combination of two or more.

The compounding amount of the fine particle size silica of the CTAB is preferably in the range of 5 to 200 parts by weight, more preferably in the range of 10 to 150 parts by weight, and still more preferably 100 parts by weight of the rubber component. Preferably, the range is 20 to 120 parts by mass. In particular, in the case of the present invention, the effect of the present invention can be exhibited even if the fine particle size silica is a high blend of 60 parts by mass or more with respect to 100 parts by mass of the rubber component.
From the viewpoint of the effect of reducing the hysteresis with respect to 100 parts by mass of the rubber component, the compounding amount of the fine particle size silica is preferably 5 parts by mass or more, and from the viewpoint of improving workability, it is preferably 200 parts by mass or less. .

In the present invention, when the fine particle silica is used, it is preferable to use a silane coupling agent from the viewpoint of reinforcement.
The silane coupling agent that can be used is not particularly limited, and examples thereof include bis (3-triethoxysilylpropyl) tetrasulfide, bis (3-triethoxysilylpropyl) trisulfide, and bis (3-triethoxysilylpropyl) disulfide. Bis (2-triethoxysilylethyl) tetrasulfide, bis (3-trimethoxysilylpropyl) tetrasulfide, bis (2-trimethoxysilylethyl) tetrasulfide, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltri Ethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, 3-nitropropyltrimethoxysilane, 3-nitropropyltriethoxysilane, 3-chloropropylmethoxysilane, 3- Lolopropyltriethoxysilane, 2-chloroethyltrimethoxysilane, 2-chloroethyltriethoxysilane, 3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-triethoxysilylpropyl-N, N- Dimethylthiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-trimethoxysilylpropylbenzothiazole tetrasulfide, 3-triethoxysilylpropylbenzothiazole tetrasulfide, 3-triethoxysilyl Propyl methacrylate monosulfide, 3-trimethoxysilylpropyl methacrylate monosulfide, bis (3-diethoxymethylsilylpropyl) tetrasulfide, 3-mer At least one of ptopropyldimethoxymethylsilane, 3-nitropropyldimethoxymethylsilane, 3-chloropropyldimethoxymethylsilane, dimethoxymethylsilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide, dimethoxymethylsilylpropylbenzothiazole tetrasulfide, etc. Is mentioned.

The blending amount of these silane coupling agents varies depending on the blending amount of silica, but preferably 1 to 20 parts by weight, more preferably 6 from the viewpoint of exothermicity, with respect to 100 parts by weight of silica. A range of ˜12 parts by mass is desirable.
The blending amount of the silane coupling agent is preferably 1 part by mass or more from the viewpoint of the effect of adding the coupling agent to 100 parts by mass of silica, and from the viewpoint of maintaining reinforcement and heat generation, 20 parts by mass or less. preferable.

In the present invention, carbon black or the like can be used as a reinforcing filler other than the silica.
Carbon black that can be used is not particularly limited, and grades such as FEF, SRF, HAF, ISAF, and SAF can be used.
The blending amount of these carbon blacks is also not particularly limited, but is preferably 0 to 60 parts by mass, more preferably 10 to 50 parts by mass with respect to 100 parts by mass of the rubber component. . In addition, 60 mass parts or less are preferable from a viewpoint of maintaining exothermic property.

The monoalkanolamide represented by the following formula (I) used in the present invention is blended in order to reduce the unvulcanized viscosity of the above-mentioned fine particle size silica-blended rubber, improve the workability and exert the effects of the present invention. To do.

In the above formula (I), R ₁ is an alkyl group or alkenyl group having 1 to 13 carbon atoms from the viewpoint of reducing the unvulcanized viscosity and tan δ. Any of branched and cyclic may be used, for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group, isopentyl group, hexyl group, isoheptyl group, 2-ethylhexyl. Group, octyl group, nonyl group, isononyl group, decyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group and other alkyl groups, allyl group, 3-butenyl group, methallyl group, 2-methyl-3-butenyl group, Examples include alkenyl groups such as 3-methyl-3-butenyl group, 1,1, -dimethyl-2-propenyl group, 4-pentenyl group, and the like. In order to further express the fruit, it is preferably an alkyl group or alkenyl group having 6 to 13 carbon atoms, more preferably 11 to 13 carbon atoms, and still more preferably 11 carbon atoms. It may be any of linear, branched and cyclic, preferably heptyl group, 2-ethylhexyl group, nonyl group, undecyl group and tridecyl group, more preferably undecyl group and tridecyl group, still more preferably. Undecyl group. Preferred examples of the fatty acid used as a raw material for the monoalkanolamide include octanoic acid, lauric acid, tetradecanoic acid, myristic acid, and the like.
In the present invention, R ₁ in the formula (I) is an alkyl group or alkenyl group having 1 to 13 carbon atoms, preferably an alkyl group having 6 to 13 carbon atoms, more preferably an alkyl group having 11 to 13 carbon atoms, as described above. The reason for limiting to the alkenyl group is that those having more than 13 carbon atoms tend to exhibit less effect of the present invention than those having 1 to 13 carbon atoms.

In the formula (I), R ₂ is a hydroxyalkyl group or a hydroxyalkyl group having an oxyalkylene unit. As said alkyl group, a C1-C6 linear or branched alkyl group is preferable, and C2-C3 is more preferable.
Further, R ₂ in the above formula (I) is preferably represented by the following formula (II), R ₃ is an alkylene group having 1 to 6 carbon atoms, and n is a number from 1 to 5. It is preferable that
_{- (R 3 O) n-} H ......... (II)
Among them, R ₃ is preferably an ethylene group or a propylene group, n is preferably 1 to ₃ , more preferably 1, R ₃ is an ethylene group, and n is more preferably 1. The n R _{3 s} may be the same or different.

  Specific examples of monoalkanolamides represented by the above formula (I) include octanoic acid monoethanolamide, octanoic acid monoisopropanepropanolamide, POE (2) octanoic acid monoethanolamide, lauric acid monoester. Examples include at least one of ethanolamide, lauric acid monoisopropanolamide, hexanoic acid monoethanolamide, octanoic acid monoethanolamide, tetradecanoic acid monoethanolamide, and POE (2) lauric acid monoethanolamide. Isopropanolamide, hexanoic acid monoethanolamide, octanoic acid monoethanolamide, decanoic acid monoethanolamide, lauric acid monoethanolamide, tetradecanoic acid monoethanolamide, POE ( ) Use of lauric acid monoethanolamide is desirable. In addition, the synthesis method of the monoalkanolamide represented by the said formula (I) is known, can be obtained by various manufacturing methods, and may use a commercially available thing.

The compounding amount of these monoalkanolamides is preferably 0.5 to 15 parts by mass, more preferably 1 to 10 parts by mass with respect to 100 parts by mass of the rubber component, more preferably from the viewpoint of exerting further effects of the present invention. 2-10 mass parts is more preferable, and 3-10 mass parts is still more preferable. Moreover, 0.5-20 mass parts is preferable with respect to 100 mass parts of silica of the said characteristic, as for the compounding quantity of monoalkanolamide, 1-15 mass parts is more preferable, and 2-12 mass parts is still more preferable.
When the blending amount of this monoalkanolamide is 0.5 parts by mass or more with respect to 100 parts by mass of the rubber component, the effect of reducing the unvulcanized viscosity is high, whereas when it is 15 parts by mass or less, the effect on the vulcanization speed is affected. Small and preferable.

The rubber composition for tires of the present invention includes a rubber in addition to the rubber component, fine particle silica having a CTAB of 180 to 250 (m ² / g), and a monoalkanolamide represented by the above formula (I). Additives usually used in the industry, such as anti-aging agents, softeners, stearic acid, zinc white, vulcanization accelerators, vulcanization accelerators, vulcanizers, etc., in a range that does not impair the object of the present invention It can select suitably and mix | blend it. As these compounding agents, commercially available products can be suitably used.
Moreover, the rubber composition for tires of the present invention comprises a rubber component, fine particle silica having a CTAB of 180 to 250 (m ² / g), the monoalkanolamide, and various blends appropriately selected as necessary. It is obtained by kneading with a kneader such as a roll or an internal mixer, heating, extruding, etc., and after molding, vulcanizing, tire tread, under tread, carcass, sidewall, It can use suitably for the use of the tire member of tires, such as a bead part.

The tire rubber composition thus configured improves the dispersibility of the fine particle silica in the tire rubber composition, does not increase the viscosity of the unvulcanized rubber, and can also improve the heat generation. Whether or not the workability is good is presumed as follows.
That is, in the tire rubber composition of the present invention, the CTAB having the above characteristics is 180 to 250 (m ² / g) with respect to at least one rubber component selected from natural rubber and / or diene synthetic rubber. When at least one monoalkanolamide represented by the above formula (I) is blended with a blending system in which a certain silica is blended, aggregation of silica is suppressed by hydrophobizing the silica surface with a fine particle size. It is presumed that the processability is good. In addition, the silica surface hydrophobizing effect is higher than fatty acid amides, tertiary amines and the like, and the processability is better than these compounds.

  A tire can be manufactured by a normal method using the rubber composition for tires of the present invention. For example, the tire rubber composition of the present invention in which various compounding agents are blended as described above is extruded into a tread member, for example, as a tire member at an unvulcanized stage, and a normal method on a tire molding machine. Is pasted and molded to form a green tire. This green tire is heated and pressurized in a vulcanizer to provide excellent low productivity and low fuel consumption, as well as excellent processability of the tire rubber composition. It will be.

  Next, although a manufacture example, an Example, and a comparative example are given and this invention is demonstrated in more detail, this invention is not limited to the following Example at all.

<Production Examples 1-5>
The monoalkanolamide used was obtained by the following production methods.
(Production Example 1)
A 500 mL four-necked flask was charged with 350 g (1.63 mol) of methyl laurate and 122.6 g (1.63 mol) of 2-amino-1-propanol, and 0.05 mass% sodium of the resulting mixture. Metoxide was added, and methanol produced by the reaction was removed by stirring at 85 ° C. for 7 hours under reduced pressure (45 mmHg) / nitrogen atmosphere. Thereafter, sodium methoxide as a catalyst was neutralized with an equivalent amount of phosphoric acid and filtered to obtain 396 g of lauric acid monoisopropanolamide.

(Production Example 2)
A 2.5-liter ethylene oxide addition device was charged with 900 g (3.70 mol) of Aminone C-01 [manufactured by Kao Corporation] and 0.1% by mass of sodium methoxide, and 326 g of ethylene oxide (120 ° C.) 7.40 mol) was added. Then, it deaerated in vacuum, cooled to 70 degreeC, and extracted. Thereafter, sodium methoxide as a catalyst was neutralized with an equivalent amount of phosphoric acid and filtered to obtain 1140 g of POE (2) lauric acid monoethanolamide.

(Production Example 3)
The reaction was conducted in the same manner as in Production Example 1 except that the ester was changed to 320 g (2.46 mol) of methyl hexanoate and the amine was changed to 150.1 g (2.46 mol) of monoethanolamine from Production Example 1 above. 362 g of hexanoic acid monoethanolamide was obtained.

(Production Example 4)
The reaction was conducted in the same manner as in Production Example 1 except that the ester was changed to 340 g (2.15 mol) of methyl octoate and the amine was changed to 131.2 g (2.15 mol) of monoethanolamine. 371 g of octanoic acid monoethanolamide was obtained.

(Production Example 5)
The reaction was conducted in the same manner as in Production Example 1 except that the ester was changed to 380 g (1.57 mol) of methyl tetradecanoate and the amine was changed to 95.8 g (1.57 mol) of monoethanolamine. Then, 401 g of tetradecanoic acid monoethanolamide was obtained.

[Examples 1-7 and Comparative Examples 1-3]
A rubber composition for tires was prepared by a conventional method with the formulation shown in Table 1 below. The numerical value in a table | surface is a mass part. In addition, CTAB of the used silica was measured by the following method.
About each obtained rubber composition for tires, the unvulcanized rubber viscosity was measured with the following measuring method. Further, the obtained rubber composition was vulcanized at 160 ° C. for 14 minutes. The obtained vulcanized rubber was measured for viscoelasticity (tan δ) by the following measurement method.
These results are shown in Table 1 below.

[Measurement of CTAB]
This was carried out in accordance with the method described in ASTM D3765-92. Since the method described in ASTM D3765-92 is a method for measuring CTAB of carbon black, some modifications were made. That is, a standard solution of cetyltrimethylammonium bromide (hereinafter abbreviated as CE-TRAB) is prepared without using IRB # 3 (83.0 m ² / g), which is a standard product of carbon black, and thereby containing water. The silicate OT (sodium di-2-ethylhexylsulfosuccinate) solution was standardized, and the adsorption cross section per molecule of CE-TRAB on the hydrous silicic acid surface was set to 0.35 nm ² from the adsorption amount of CE-TRAB. m ² / g) was calculated. This is because carbon black and hydrous silicic acid have different surfaces, and it is considered that there is a difference in the amount of CE-TRAB adsorbed even with the same surface area.

[Measurement method of unvulcanized rubber viscosity]
The unvulcanized rubber viscosity and scorch time were determined in accordance with JIS K 6300-1: 2001 (Mooney viscosity, Mooney scorch time).
The evaluation was expressed as an index with the value of Comparative Example 1 being 100. The smaller the value of the unvulcanized rubber viscosity, the better the workability.

[Measurement method of viscoelasticity (tan δ)]
Using a viscoelasticity measuring device (manufactured by Rheometrics), tan δ was measured at a temperature of 50 ° C., a strain of 5%, and a frequency of 15 Hz. It shows that low exothermic property is so favorable that this value is small.

* 1 to * 18 in Table 1 are as follows.
* 1) SBR # 1723 (manufactured by JSR) (100 parts by mass of rubber component, 37.5 parts by mass of oil component)
* 2) Seast 7HM [Tokai Carbon Co., Ltd.]
* 3) “Nipsil VN3” manufactured by Tosoh Silica Corporation [CTAB: 144 (m ² / g)]
* 4) “Zeosil Premium 200MP (trade name)” manufactured by Rhodia [CTAB: 200 (m ² / g)]
* 5) “Zeosil HRS 1200MP (trade name)” manufactured by Rhodia [CTAB: 195 (m ² / g)]
* 6) Bis (3-triethoxysilylpropyl) tetrasulfide * 7) Microcrystalline wax, Ozoace 0701 [Nippon Seiwa Co., Ltd.]
* 8) NOCRACK 6C (Ouchi Shinsei Chemical Co., Ltd.)
* 9) Non-flex RD-S [Seiko Chemical Co., Ltd.]
* 10) Noxeller D [Ouchi Shinsei Chemical Co., Ltd.]
* 11) Noxeller DM (Ouchi Shinsei Chemical Co., Ltd.)
* 12) Sunseller CM-G [manufactured by Sanshin Chemical Industry Co., Ltd.]
* 13) Compound of Production Example 1 * 14) Compound of Production Example 2 * 15) Aminone C-01 [lauric acid monoethanolamide, manufactured by Kao Corporation]
* 16) Compound of Production Example 3 * 17) Compound of Production Example 4 * 18) Compound of Production Example 5

  As is clear from Table 1 above, the rubber compositions for tires of Examples 1 to 7 that fall within the scope of the present invention are compared with Comparative Examples 1 to 3 that are outside the scope of the present invention. From the evaluation results of elasticity (tan δ), it was found that the rubber composition for a tire can be obtained in which the viscosity of the unvulcanized rubber is not increased, the heat generation property can be improved, and the processability is good.

  It can be suitably used for a tire member of a pneumatic tire such as a tire tread, an under tread, a carcass, a sidewall, and a bead portion.

Claims (6)

Against natural rubber and / or at least one rubber component 100 parts by weight is selected from the diene synthetic rubbers, silica 5 cetyltrimethylammonium bromide (CTAB) adsorption specific surface area of 180~250 (m ² / g) A rubber composition for tires, comprising 200 parts by mass and 0.5 to 15 parts by mass of at least one monoalkanolamide represented by the following formula (I).

R ₁ in the above formula (I) is methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group, isopentyl group, hexyl group, isoheptyl group, 2-ethylhexyl group. Octyl group, nonyl group, isononyl group, decyl group, undecyl group, dodecyl group, tridecyl group, or isotridecyl group, and R ₂ is a hydroxyalkyl group or a hydroxyalkyl group having an oxyalkylene unit. The tire rubber composition according to claim 1. R ₂ in the above formula (I) is represented by the following formula (II), R ₃ is an alkylene group having 1 to 6 carbon atoms, and n is a number of 1 to 5. The rubber composition for tires according to claim 1 or 2 .
_{- (R 3 O) n-} H ......... (II) Furthermore, a silane coupling agent is mix | blended, The rubber composition for tires as described in any one of Claims 1-3 characterized by the above-mentioned. The rubber composition for tires according to claim 4 , wherein the amount of the silane coupling agent is 1 to 20 parts by mass with respect to 100 parts by mass of silica. Claim 1-5 in which the amount of mono-alkanolamides of the formula (I) is, with respect to the 100 parts by mass of silica, characterized in that 0.5 to 20 parts by weight The rubber composition for tires described in 1.