JP2013163822A - Method for producing rubber composition, rubber composition produced by the same, and tire using the rubber composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a rubber composition simultaneously satisfying LRR (low rolling resistance=low tanδ), high steering stability (=high E*) and chipping (=fracture energy=high EB%).SOLUTION: A method for producing a rubber composition includes (1) a step (MB) of adding and kneading a dienic rubber and zinc oxide in a predetermined mass ratio to thereby prepare a master batch, (2) a step (X) of adding 10 to 100 pts.mass of silica based on 100 pts.mass of a dienic rubber and kneading the mixture, and (3) then, a step (F2) of adding the master batch obtained in the step (MB) to the kneaded material obtained in the step (X), further adding 0.1 to 10 pts.mass of a methacrylic acid metal salt, and sulfur and a vulcanization accelerator in predetermined amounts, and kneading the mixture, wherein 100 pts.mass of the dienic rubber contains 10 to 100 pts.mass of the silica and 0.1 to 10 pts.mass of the methacrylic acid metal salt.

Description

  The present invention relates to a method for producing a rubber composition, a rubber composition obtained thereby, and a tire using the rubber composition.

  In developing a rubber composition for tires, it is difficult to achieve both of LRR (low rolling resistance = low tan δ), high steering stability (= high E *), and chipping (= fracture energy = high EB%). It is. In order to achieve both low tan δ, high E * and high EB%, the following measures are taken.

(1) Replace carbon with silica. Furthermore, large particle silica is used.
(2) A natural rubber (NR) excellent in breaking energy is used in a rubber component in an amount of 60% by mass or more. Furthermore, high molecular weight NR is used.
(3) A sulfur-containing crosslinking aid (for example, Takuro Chemical V200 (alkylphenol / sulfur chloride condensate) manufactured by Taoka Chemical Co., Ltd.) and a sulfur-free crosslinking aid (eg, HTS (hexa Methylenebisthiosulfate disodium salt dihydrate): Duralink HTS manufactured by Flexis, PK900: PERKALINK900 (1,3-bis (citraconimidomethyl) benzene) manufactured by Flexis.

  By the methods (1) to (3), it is possible to form a thermally stable cross-link between the polymers, reduce the polymer cutting when the bound sulfur once formed is released, suppress reversion, and increase the molecular weight of the polymer. Can hold.

(4) Using modified S-SBR and modified BR, the bonding force between the filler and the polymer is increased, and the filler dispersion is also improved. Furthermore, a heat-resistant silica coupling agent having excellent bonding strength is used.
(5) A modified resorcin (for example, resorcin-alkylphenol-formalin copolymer (Sumikanol 620 manufactured by Sumitomo Chemical Co., Ltd.)) is blended to increase E * and simultaneously reduce the filler blending amount.
(6) Zinc methacrylate is added to the base and added simultaneously with silica to increase E * and simultaneously reduce filler.

  However, even if the above (1) to (5) are adopted in response to the recent demand for LRR (low rolling resistance = low tan δ), the current situation is that the needs have not yet been fully met.

  Further, even when the above (6) is adopted, E * can be accumulated, but LRR (low rolling resistance = low tan δ) cannot be obtained (that is, tan δ is increased), and the amount of filler is reduced. The low tan δ decrease is offset.

  For example, in Patent Document 1, for the purpose of providing a rubber composition having a reduced rolling resistance and a tire comprising the rubber composition without significantly reducing the wear resistance, (A) rubber component 100 is provided. 1 to 3 parts by weight of a carboxylic acid metal salt selected from the group consisting of (B) magnesium methacrylate, zinc methacrylate and aluminum methacrylate with respect to parts by weight, (C) N, N′-bis (2-methyl-) 2-nitropropyl) -1,6-hexanediamine in an amount of 1 to 3 parts by weight, and (D) silica and / or carbon black, and 65 to 100% by weight of the silica and / or carbon black (D) is silica. Certain rubber compositions are disclosed. However, in Patent Document 1, a carboxylic acid metal salt selected from the group consisting of a rubber component, magnesium methacrylate, zinc methacrylate and aluminum acrylate, silica and / or carbon black and a silane coupling agent are simultaneously applied at 150 ° C. or higher. Therefore, it is considered that adsorption of silica and zinc white (zinc oxide) occurs, and high tan δ (that is, rolling resistance is not excellent) occurs.

  That is, there is room for improvement in terms of achieving both of LRR (low rolling resistance = low tan δ), high steering stability (= high E *), and chipping (= fracture energy = high EB%).

JP 2003-213045 A

  The present invention provides a method for producing a rubber composition that achieves both LRR (low rolling resistance = low tan δ), high steering stability (= high E *), and chipping (= fracture energy = high EB%). With the goal.

The second aspect of the present invention is the following steps (MB), (X) and (F2):
(1) There is a step (MB) of adding a diene rubber and zinc oxide at a mass ratio of 1: 0.2 to 1: 4.0 and kneading to prepare a master batch,
(2) Step (X) of adding and kneading 10 to 100 parts by mass of silica to 100 parts by mass of diene rubber.
(3) Next, to the kneaded material obtained in the step (X), 1 to 10 parts by mass of the master batch obtained in the step (MB) is added to 100 parts by mass of the diene rubber. Furthermore, the process (F2) which knead | mixes together 0.1-10 mass parts of metal methacrylate, sulfur, and a vulcanization accelerator with respect to 100 mass parts of said diene rubbers.
A process for producing a rubber composition comprising:
The present invention relates to a method for producing a rubber composition containing 10 to 100 parts by mass of silica and 0.1 to 10 parts by mass of a metal methacrylate based on 100 parts by mass of a diene rubber.

  The present invention relates to a rubber composition obtained by the production method.

  The present invention relates to a tire using a rubber composition obtained by the above production method as a base tread.

  According to the production method of the present invention, a rubber composition capable of achieving both LRR (low rolling resistance = low tan δ), high steering stability (= high E *), and chipping (= fracture energy = high EB%) is obtained. Can be obtained. When the tan δ value of the rubber composition is low, it indicates that the rolling resistance is low (LRR), which is good. A high E * (complex elastic modulus) value of the rubber composition indicates excellent steering stability. When the value of EB (%) (elongation at break) is high, the fracture energy (crack growth and chipping) is excellent.

  The manufacturing method of the 1st rubber composition of this invention is demonstrated.

The first aspect of the present invention is the following steps (X) and (F1):
(1) Step (X) of adding and kneading 10 to 100 parts by mass of silica to 100 parts by mass of diene rubber
(2) Next, with respect to the kneaded material obtained by the step (X), 0.1 to 10 parts by mass of a metal methacrylate salt, sulfur and a vulcanization accelerator are added to 100 parts by mass of the diene rubber. Step of adding and kneading (F1)
A process for producing a rubber composition comprising:
It is a manufacturing method of the rubber composition which contains 10-100 mass parts of silica and 0.1-10 mass parts of methacrylic acid metal salt with respect to 100 mass parts of diene rubbers.

  In the manufacturing method of the 1st rubber composition of this invention, there exists the process (X) kneaded. In the kneading step (X), 10 to 100 parts by mass of silica is added and kneaded with respect to 100 parts by mass of the diene rubber.

  The diene rubber contained in the kneading step (X) is not particularly limited as long as it is used for tires. For example, natural rubber (NR), isoprene rubber (IR), butadiene Examples thereof include rubber (BR), styrene butadiene rubber (SBR), acrylonitrile butadiene rubber (NBR), chloroprene rubber (CR), and ethylene propylene diene rubber (EPDM). These diene rubbers may be used alone or in combination of two or more. Among these diene rubbers, natural rubber (NR) is preferably used because of its excellent breaking strength and processability. In addition, because of its low heat build-up and excellent reversion suppression, solution-polymerized styrene butadiene rubber (S-SBR) (for example, HPR340 manufactured by JSR Corporation (terminal structure of molecular chain: structure having interaction with silica, Bonded styrene content: 10%, vinyl content: 42%)) is preferred.

  The silica contained in the kneading step (X) is not particularly limited as long as it is used for tires.

The nitrogen adsorption specific surface area (N ₂ SA) of silica is preferably 100 m ² / g or more, more preferably 110 m ² / g or more, because it is excellent in durability (reinforcing property). The N ₂ SA of the silica, for the reason that it is possible to prevent the heat generation is increased by the dispersion deteriorates, preferably 300 meters ² / g or less, more preferably 290 m ² / g.

  When silica is blended as a filler, the blending amount of silica is 10 to 100 parts by mass, preferably 20 to 100 parts by mass of the rubber component, from the viewpoint of excellent wet grip and rolling resistance characteristics (low heat generation). -90 mass parts, More preferably, it is 30-80 mass parts.

  When silica is used in the present invention, it is preferable to contain a silane coupling agent. The silane coupling agent that can be suitably used in the present invention can be any silane coupling agent conventionally used in combination with silica. Specifically, bis (3-triethoxysilylpropyl) tetrasulfide, bis (2-triethoxysilylethyl) tetrasulfide, bis (4-triethoxysilylbutyl) tetrasulfide, bis (3-trimethoxysilylpropyl) Tetrasulfide, bis (2-trimethoxysilylethyl) tetrasulfide, bis (4-trimethoxysilylbutyl) tetrasulfide, bis (3-triethoxysilylpropyl) trisulfide, bis (2-triethoxysilylethyl) trisulfide Bis (4-triethoxysilylbutyl) trisulfide, bis (3-trimethoxysilylpropyl) trisulfide, bis (2-trimethoxysilylethyl) trisulfide, bis (4-trimethoxysilylbutyl) trisulfide, bis (3- Riethoxysilylpropyl) disulfide, bis (2-triethoxysilylethyl) disulfide, bis (4-triethoxysilylbutyl) disulfide, bis (3-trimethoxysilylpropyl) disulfide, bis (2-trimethoxysilylethyl) disulfide Bis (4-trimethoxysilylbutyl) disulfide, 3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-triethoxysilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide, 2-triethoxy Silylethyl-N, N-dimethylthiocarbamoyl tetrasulfide, 2-trimethoxysilylethyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-trimethoxysilylpropylbenzothiazolylte Sulfides such as rasulfide, 3-triethoxysilylpropylbenzothiazole tetrasulfide, 3-triethoxysilylpropyl methacrylate monosulfide, 3-trimethoxysilylpropyl methacrylate monosulfide, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltrisulfide Mercapto series such as ethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, vinyl series such as vinyltriethoxysilane, vinyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltri Amino series such as methoxysilane, 3- (2-aminoethyl) aminopropyltriethoxysilane, 3- (2-aminoethyl) aminopropyltrimethoxysilane, γ Glycidoxy systems such as glycidoxypropyltriethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, 3-nitropropyltrimethoxysilane, Nitro-based compounds such as 3-nitropropyltriethoxysilane, chloro-based compounds such as 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 2-chloroethyltrimethoxysilane and 2-chloroethyltriethoxysilane It is done. Bis (3-triethoxysilylpropyl) tetrasulfide, bis (3-triethoxysilylpropyl) disulfide, 3-mercaptopropyltrimethoxysilane and the like are preferably used because of the effect of adding a coupling agent and cost. These silane coupling agents may be used alone or in combination of two or more. Examples of the silane coupling agent include Si69 (bis (3-triethoxysilylpropyl tetrasulfide), Si75 (bis (3-triethoxysilylpropyl disulfide), Si266, and the like, and the effect of improving the dispersibility of silica can be mentioned. It is preferable to use Si266 because it is obtained and rubber burn hardly occurs.

  The blending amount of the silane coupling agent is preferably 1 to 15 parts by mass with respect to 100 parts by mass of silica from the viewpoint that a coupling effect can be obtained at an appropriate cost and that even better reinforcement and wear resistance can be achieved. 4-10 mass parts is more preferable.

  The kneading temperature in the kneading step (X) is preferably 140 to 170 ° C., more preferably 150 to 165 ° C., from the reason that the silica is sufficiently dispersed to prevent rubber burning. Silica dispersion is involved in LRR (= tan δ 30 ° C.).

  The kneading time in the kneading step (X) varies depending on the kneader, the rotational speed of the kneader used, and the rubber filling rate.

  In the manufacturing method of the 1st rubber composition of this invention, there exists a process (F1) knead | mixed. In the kneading step (F1), 0.1 to 10 parts by mass of a metal methacrylate and 0.1 to 10 parts by mass of sulfur and vulcanized with respect to 100 parts by mass of the diene rubber with respect to the kneaded product obtained in the step (X). Add accelerator and knead.

（式中、Ｍは金属、ｘは１または２の整数である）
で表される。 The metal methacrylate used in the method for producing the first rubber composition of the present invention,

(Wherein M is a metal, x is an integer of 1 or 2)
It is represented by

  As a result of the synergistic effect of the metal M contained in the methacrylic acid metal salt with the crosslinking precursor formed by sulfur, a vulcanization accelerator, and zinc oxide (ZnO), when the metal M is Zn (zinc), the crosslinking efficiency is the highest. Zinc is preferred because it is expensive. Usually, a complex of [sulfur]-[vulcanization accelerator]-[ZnO] accelerates the crosslinking reaction. In the present invention, the complex complex of [sulfur]-[vulcanization accelerator]-[ZnO]-[zinc methacrylate] has good dispersibility and has a large number of complexes, so that it is considered that the crosslinking reaction is promoted.

  When the metal methacrylate is mixed, the amount of the metal methacrylate is 0.1 relative to 100 parts by mass of the diene rubber because the E * of the rubber can be improved and tan δ can be reduced. -10 parts by mass, preferably 0.5-8 parts by mass, more preferably 1.0-6 parts by mass.

  The method for producing the rubber composition of the present invention does not involve kneading a metal methacrylate salt (preferably a zinc methacrylate salt) at the same time as silica or a coupling agent. However, it is characterized by kneading in a kneading stage (stage) after silica or a coupling agent.

  The reason why the metal salt of methacrylic acid is not kneaded at the same time as silica is based on the adsorption mechanism of zinc oxide and silica. In the base kneading, the silica and the coupling agent are efficiently bonded, and the silica and the rubber polymer are also efficiently bonded, so that the silica is efficiently dispersed in the rubber component. However, zinc oxide inhibits these cycles. Therefore, metal methacrylate salts, particularly zinc methacrylate salts, are better dispersed in rubber than zinc oxide, and zinc of zinc methacrylate attracts OH groups (hydroxyl groups) on the silica surface with high probability. Zinc methacrylate can promote the sulfur cross-linking reaction and further improve the physical properties without sacrificing the original advantages of silica and coupling agent blending (strong chemical bond with polymer, high dispersion). The effect of vulcanization acceleration is derived from the fact that zinc methacrylate is highly dispersed, so that a large number of composite vulcanization accelerator precursors of vulcanization accelerator / zinc white (zinc oxide) / stearic acid can be produced. It is believed that. As a result, LRR / high maneuverability / chipping can be improved in a balanced manner.

  When sulfur is used in the kneading step (F1), the brand, solubility, or insolubility are not particularly limited.

  The kneading temperature in the kneading step (F1) prevents the vulcanized rubber from being burned by sulfur and a vulcanization accelerator, and can promote the dispersion of the chemical compounded in the kneading step (F1). 80 to 120 ° C is preferable, and 90 to 115 ° C is more preferable.

  The kneading time in the kneading step (F1) varies depending on the kneader, the rotational speed of the kneader used, and the rubber filling rate.

  Next, the manufacturing method of the 2nd rubber composition of this invention is demonstrated.

The second aspect of the present invention is the following steps (MB), (X) and (F2):
(1) There is a step (MB) of adding a diene rubber and zinc oxide at a mass ratio of 1: 0.2 to 1: 4.0 and kneading to prepare a master batch,
(2) Step (X) of adding and kneading 10 to 100 parts by mass of silica to 100 parts by mass of diene rubber.
(3) Next, to the kneaded material obtained in the step (X), 1 to 10 parts by mass of the master batch obtained in the step (MB) is added to 100 parts by mass of the diene rubber. Furthermore, the process (F2) which knead | mixes together 0.1-10 mass parts of metal methacrylate, sulfur, and a vulcanization accelerator with respect to 100 mass parts of said diene rubbers.
A process for producing a rubber composition comprising:
It is a manufacturing method of the rubber composition which contains 10-100 mass parts of silica and 0.1-10 mass parts of methacrylic acid metal salt with respect to 100 mass parts of diene rubbers.

  In the manufacturing method of the 2nd rubber composition of this invention, there exists a process (MB) which prepares a masterbatch first. In the step of preparing a master batch (MB), a diene rubber and zinc oxide are added at a mass ratio of 1: 0.2 to 1: 4.0 and kneaded to prepare a master batch.

  The diene rubber contained in the masterbatch is not particularly limited as long as it is used for tires. For example, natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), Examples thereof include styrene butadiene rubber (SBR), acrylonitrile butadiene rubber (NBR), chloroprene rubber (CR), ethylene propylene diene rubber (EPDM) and the like. These rubber components (A) may be used alone or in combination of two or more. Among these rubber components (A), natural rubber (NR) or isoprene rubber (IR) is used because the processability and the cohesiveness (dispersibility) with zinc oxide (zinc white) can be maintained well. It is preferable to use natural rubber (NR).

  In the step (MB) of preparing the master batch, diene rubber and zinc oxide are added for the reason that dispersibility, further wear resistance and elongation at break can be improved by pre-blending zinc white with rubber. : Added at a mass ratio of 0.2 to 1: 4.0 and kneaded. When the compounding ratio of zinc oxide is small (that is, when the mass ratio of diene rubber and zinc oxide is less than 1: 0.2), the master batch obtained by the process (MB) in the following process (F2) Since it is necessary to add a large amount, the performance of the final rubber compounding is not preferable. The weight of diene rubber and zinc oxide is 1: 0.3 because the dispersion of zinc oxide is good, the rubber cohesion (= workability) is maintained, and the rubber compounding performance is finally good. It is preferable to add and knead by ratio, and it is more preferable to add and knead by mass ratio of 1: 3.

  In the manufacturing method of the 2nd rubber composition of this invention, there exists the process (X) knead | mixed. In the kneading step (X), 10 to 100 parts by mass of silica is added and kneaded with respect to 100 parts by mass of the diene rubber. The aspect of the kneading step (X) in the method for producing the second rubber composition of the present invention is the same as the method for producing the first rubber composition of the present invention described above.

  In the manufacturing method of the 2nd rubber composition of this invention, there exists a process (F2) knead | mixed. In the kneading step (F2), the master batch obtained in the step (MB) is added to the kneaded product obtained in the step (X), and further to 100 parts by mass of the diene rubber. Kneading together 0.1 to 10 parts by mass of a metal salt of methacrylic acid, sulfur and a vulcanization accelerator.

  In the kneading step (F2), silica and zinc white are prevented from being adsorbed, and the number of bonds (efficiency) of silica-coupling agent-polymer can be increased. The master batch obtained in the step (MB) is added to the kneaded product and kneaded. The blending amount of the master batch depends on the blending of the step (X) or the following step (F2), but with respect to the kneaded product obtained by the step (X), 100 parts by mass of the diene rubber, The master batch obtained in the step (MB) is added and kneaded so that the amount of zinc oxide is preferably 1 to 10 parts by mass, more preferably 2 to 5 parts by mass.

  In the kneading step (F2), 0.1 to 10 parts by mass of a metal methacrylate salt, sulfur and a vulcanization accelerator are further added and kneaded with respect to 100 parts by mass of the diene rubber.

  The metal methacrylate used in the method for producing the second rubber composition of the present invention is the same as the metal methacrylate used in the method for producing the first rubber composition of the present invention.

  Kneading step (F2) The sulfur to be used is the same as the sulfur used in the above-described method for producing the first rubber composition of the present invention, and there is no particular limitation on the brand, solubility and insolubility.

  The kneading temperature in the kneading step (F2) and the kneading time in the kneading step (F2) are the same as those in the method for producing the first rubber composition of the present invention described above.

  The following rubber composition manufacturing method (third rubber composition manufacturing method) will be described.

The method for producing the third rubber composition includes the following steps (X), (Y) and (F3):
(1) Step (X) of adding and kneading 10 to 100 parts by mass of silica to 100 parts by mass of diene rubber
(2) Next, a step of adding 0.1 to 10 parts by mass of a metal methacrylate salt to 100 parts by mass of the diene rubber and kneading the kneaded product obtained in the step (X). (Y),
(3) Next, the step of kneading the kneaded product obtained in the step (Y) with further adding sulfur and a vulcanization accelerator to 100 parts by mass of the diene rubber (F3)
A process for producing a rubber composition comprising:
It is a manufacturing method of the rubber composition which contains 10-100 mass parts of silica and 0.1-10 mass parts of methacrylic acid metal salt with respect to 100 mass parts of diene rubbers.

  In the third method for producing a rubber composition, there is a step (X) of kneading. In the kneading step (X), 10 to 100 parts by mass of silica is added and kneaded with respect to 100 parts by mass of the diene rubber. The aspect of the kneading step (X) in the third method for producing a rubber composition is the same as the method for producing the first rubber composition of the present invention described above.

  In the third method for producing a rubber composition, there is a kneading step (Y). In the kneading step (Y), 0.1 to 10 parts by mass of a metal methacrylate is added to and mixed with 100 parts by mass of the diene rubber to the kneaded product obtained in the step (X). Knead.

  The metal methacrylate used in the method for producing the third rubber composition is the same as the metal methacrylate used in the method for producing the first rubber composition of the present invention.

  The kneading temperature in the kneading step (Y) is such that the methacrylic acid metal salt dissolves and disperses, the silica coupling agent bonded to the polymer is not detached, and the remaining coupling agent is not burned. 90-170 degreeC is preferable and 100-165 degreeC is more preferable from the reason that the remill effect of the further dispersion | distribution improvement of rubber | gum, a silica, and each chemical | medical agent can be anticipated.

  The kneading time in the kneading step (Y) is the same as the kneading step (X) in the above-described method for producing the first rubber composition of the present invention.

  In the third method for producing a rubber composition, there is a kneading step (F3). In the kneading step (F3), the kneaded material obtained in the step (Y) is further kneaded with 100 parts by mass of the diene rubber and sulfur and a vulcanization accelerator.

When sulfur is used in the kneading step (F3), for example, 5% oil-treated powder sulfur manufactured by Tsurumi Chemical Co., Ltd. can be used. Moreover, insoluble sulfur is preferable because it is excellent in dispersibility. Specifically, Kristex HSOT 20 manufactured by Flexis, Sanfel EX manufactured by Sanshin Chemical Industry Co., Ltd., or the like may be used. Here, insoluble sulfur refers to high molecular weight sulfur in which the eight-membered cyclic structure of S ₈ undergoes radical cleavage and is connected in a chain, and is insoluble in carbon disulfide and rubber-like hydrocarbons. It is.

  In the kneading step (F3), sulfur and a vulcanization accelerator are appropriately blended.

  The kneading temperature in the kneading step (F3) prevents the vulcanized rubber from being burned by sulfur and a vulcanization accelerator, and can promote the dispersion of each chemical compounded in the kneading step (F1). Therefore, 80 to 120 ° C is preferable, and 90 to 115 ° C is more preferable.

  The kneading time in the kneading step (F1) varies depending on the kneader, the rotational speed of the kneader used, and the rubber filling rate.

  Moreover, this invention relates to the rubber composition obtained by the manufacturing method of the 1st and 2nd rubber composition of the said invention.

  The rubber composition obtained by the production method of the present invention may contain carbon black when steering stability and E * are required. For preventing tan δ from rising and not deteriorating rolling resistance, 0 to 40 parts by mass of carbon black may be blended with 100 parts by mass of the diene rubber. included. Although it does not necessarily restrict | limit as carbon black, For example, the thing of grades, such as SAF, ISAF-HM, ISAF-LM, ISAF-HS, HAF, and FEF, can be used. N660 to N315 are suitable for use.

  The rubber composition obtained by the production method of the present invention is preferably used as a base tread in a tire because the ultimate low tan δ and good steering stability (E * is moderately high) can be obtained. . Since the rubber composition obtained by the production method of the present invention does not require wear resistance, the filler may be as small as 30 to 40 parts by weight. When used for a side wall, it may be tuned to improve crack growth resistance by blending butadiene rubber.

  The tire of the present invention is produced by a normal method using the rubber composition produced by the production method of the present invention. That is, the rubber composition produced by the production method of the present invention is extruded in accordance with the shape of each member of the tire, preferably the base tread, at an unvulcanized stage, and is processed on a tire molding machine by a usual method. An unvulcanized tire is formed by molding. The unvulcanized tire is heated and pressurized in a vulcanizer to obtain the tire of the present invention.

  The present invention will be specifically described based on examples, but the present invention is not limited to these examples.

（式中、Ｍは亜鉛、ｘは１または２の整数である）
硫黄：鶴見化学工業（株）製の５％オイル処理粉末硫黄
加硫促進剤ＴＢＢＳ：大内新興化学工業（株）製のノクセラーＮＳ（Ｎ−ｔ−ブチル−２−ベンゾチアジル・スルフェンアミド）
加硫促進剤ＤＰＧ：大内新興化学工業（株）製のノクセラーＤ（Ｎ，Ｎ’−ジフェニルグアニジン）
タッキロールＶ２００：田岡化学工業（株）製のタッキロールＶ２００（アルキルフェノール・塩化硫黄縮合物、ｘおよびｙ：２、Ｒ：Ｃ₈Ｈ₁₇のアルキル基、硫黄含有率：２４質量％）

（式中、ｎは０〜１０の整数である） Hereinafter, various chemicals used in Examples, Reference Examples and Comparative Examples will be described together.
<Master batch (MB)>
Natural rubber (NR): TSR20
Zinc Hana: Zinc oxide manufactured by Mitsui Mining & Smelting Co., Ltd.
Solution-polymerized styrene butadiene rubber (S-SBR) (HPR): HPR340 manufactured by JSR Corporation (terminal structure of molecular chain: structure interacting with silica, amount of bonded styrene: 10%, vinyl amount: 42%)
Natural rubber (NR): TSR20
Silica (Z115Gr): Z115GR manufactured by Rhodia (N ₂ SA: 112 m ² / g)
Carbon black: Dia Black E (N550) manufactured by Mitsubishi Chemical Corporation
Silane coupling agent: Si266 (bis (3-triethoxysilylpropyl) disulfide) manufactured by Degussa
Zinc flower: Zinc oxide stearic acid manufactured by Mitsui Mining & Smelting Co., Ltd .: Anti-aging agent manufactured by Nippon Oil & Fats Co., Ltd. (6C): NOCRACK 6C manufactured by Ouchi Shinsei Chemical Co., Ltd. (N-1,3- Dimethylbutyl-N′-phenyl-p-phenylenediamine)
Wax: Sunnock wax aroma oil manufactured by Ouchi Shinsei Chemical Co., Ltd .: Process X-140 manufactured by Japan Energy Co., Ltd.
Zinc methacrylate: PRO (Pro) 11234 manufactured by Sartomer

(Wherein M is zinc and x is an integer of 1 or 2)
Sulfur: 5% oil-treated powder sulfur vulcanization accelerator manufactured by Tsurumi Chemical Co., Ltd. TBBS: Noxeller NS (Nt-butyl-2-benzothiazyl sulfenamide) manufactured by Ouchi Shinsei Chemical Co., Ltd.
Vulcanization accelerator DPG: Noxeller D (N, N'-diphenylguanidine) manufactured by Ouchi Shinsei Chemical Co., Ltd.
Tacchirol V200: Tacakol V200 manufactured by Taoka Chemical Industry Co., Ltd. (alkylphenol / sulfur chloride condensate, x and y: 2, R: alkyl group of C ₈ H ₁₇ , sulfur content: 24% by mass)

(In the formula, n is an integer of 0 to 10)

Examples 9 and 12, Reference Examples 1-8, 10 and 11, and Comparative Examples 1-10
(Preparation of masterbatch)
In Examples 9 and 12, a master batch was used. The maximum kneading temperature was set at 165 ° C.

  In Example 9, a masterbatch was prepared by pre-blending natural rubber and zinc oxide with a kneader at a mass ratio of 1: 3. The content of zinc white in the master batch used in Example 9 is 75% by mass. In Example 9, 3.33 parts by mass of the master batch (zinc oxide MB) was compounded so that the compounding amount of zinc oxide was 2.5 parts by mass, and the natural rubber (NR) contained in the master batch The amount is 0.83 parts by mass.

  In Example 12, a masterbatch was prepared by pre-blending natural rubber and zinc oxide with a kneader at a mass ratio of 1: 1. The content of zinc white in the master batch used in Example 12 is 50% by mass. In Example 12, 5 parts by mass of the master batch (zinc oxide MB) is compounded so that the compounding amount of zinc oxide is 2.5 parts by mass, and the amount of natural rubber (NR) contained in the master batch is 2.5 parts by mass.

(X kneading, Y kneading and F kneading)
According to the prescription (compounding agent, blending amount) shown in Tables 1 to 4, X-kneading, Y-kneading, and F-kneading are performed. A vulcanized rubber composition was produced.

  X kneading was performed using a Banbury mixer under conditions of a kneading temperature of 150 ° C. and a kneading time of 5 minutes to obtain a kneaded product.

  Y-kneading was performed using a Banbury mixer under conditions of a kneading temperature of 150 ° C. and a kneading time of 4 minutes to obtain a kneaded product.

F kneading is performed using an open roll to add insoluble sulfur, a vulcanization accelerator and CTP to the obtained kneaded product under the conditions of a kneading temperature of 95 ° C. and a kneading time of 3 minutes. Obtained. Vulcanization of Examples 9 and 12, Reference Examples 1 to 8, 10 and 11, and Comparative Examples 1 to 10 was performed by press vulcanizing the obtained unvulcanized rubber composition at 170 ° C. for 12 minutes. A rubber composition was produced.
Each composition at the time of carrying out X kneading, Y kneading, and F kneading is shown in Tables 1-4.

(Viscoelasticity test: Complex modulus (E *) and loss tangent (tan δ))
Using a viscoelastic spectrometer VES manufactured by Iwamoto Seisakusho Co., Ltd., a complex elastic modulus E * (MPa) of a vulcanized rubber composition at a temperature of 30 ° C. under conditions of a frequency of 10 Hz, an initial strain of 10% and a dynamic strain of 2%. ) And loss tangent tan δ were measured. In addition, it shows that rigidity is so high that E * is large and steering stability is excellent, and exothermic property is low and it is excellent, so that tan-delta is small.

(Tensile test)
Using a No. 3 dumbbell-shaped test piece composed of the vulcanized rubber composition, a tensile test was conducted according to JIS K 6251 “Vulcanized Rubber and Thermoplastic Rubber—How to Obtain Tensile Properties”, and elongation at break EB (%) Was measured. In addition, it shows that it is excellent, so that EB is large.

  The said evaluation result is shown to Tables 1-4.

  From Reference Examples 1 to 3, according to the manufacturing method of adding zinc methacrylate by F-kneading, according to the manufacturing method of the present invention, LRR (low rolling resistance = low tan δ), high steering stability (= high E *) A rubber composition capable of achieving both chipping (= fracture energy = high EB%) could be obtained.

  From Reference Example 4, according to the production method of adding zinc methacrylate by Y-kneading, according to the production method of the present invention, LRR (low rolling resistance = low tan δ), high steering stability (= high E *), chipping A rubber composition capable of achieving both (= breaking energy = high EB%) could be obtained.

(Maneuvering stability)
The rubber composition of the present invention is extruded according to the shape of the base tread of the tire at an unvulcanized stage, and molded by a normal method on a tire molding machine to form an unvulcanized tire, A test tire of the present invention was obtained by heating and pressurizing an unvulcanized tire in a vulcanizer. The test tire was mounted on a vehicle (domestic FF2000cc) and the vehicle was run on the test course, and the driving stability was evaluated by sensory evaluation of the driver. Evaluation was made relative with 6 points being the perfect score and Comparative Example 1 being 3 points. The larger the score, the better the steering stability.

Claims (3)

The following steps (MB), (X) and (F2):
(1) There is a step (MB) of adding a diene rubber and zinc oxide at a mass ratio of 1: 0.2 to 1: 4.0 and kneading to prepare a master batch,
(2) Step (X) of adding and kneading 10 to 100 parts by mass of silica to 100 parts by mass of diene rubber.
(3) Next, the masterbatch obtained in the step (MB) is added to the kneaded material obtained in the step (X), and further, metal methacrylate is added to 100 parts by mass of the diene rubber. Step of kneading together 0.1 to 10 parts by mass of salt, sulfur and vulcanization accelerator (F2)
A process for producing a rubber composition comprising:
The manufacturing method of the rubber composition which contains 10-100 mass parts of silica and 0.1-10 mass parts of methacrylic acid metal salt with respect to 100 mass parts of diene rubbers. A rubber composition obtained by the production method according to claim 1. A tire using the rubber composition according to claim 2 as a base tread.