WO2023112393A1

WO2023112393A1 - Tire rubber composition, and tire

Info

Publication number: WO2023112393A1
Application number: PCT/JP2022/032293
Authority: WO
Inventors: 皓介齋藤
Original assignee: 株式会社ブリヂストン
Priority date: 2021-12-15
Filing date: 2022-08-26
Publication date: 2023-06-22
Also published as: JP2023088674A

Abstract

The present invention addresses the problem of providing a tire rubber composition that achieves both scorch resistance and bloom resistance. The problem is solved by a tire rubber composition characterized by including a rubber component, an amine anti-aging agent, and a vulcanization retarder, and moreover characterized in that the amine anti-aging agent is represented by general formula (1), the amine anti-aging agent content is 0.1 part by mass or more per 100 parts by mass of the rubber component, the vulcanization retarder is represented by general formula (2), and the vulcanization retarder content is 0.005 part by mass or more per 100 parts by mass of the rubber component. [In formula (1), R¹ and R² each independently represent a monovalent saturated hydrocarbon group; in formula (2), R³ and R⁴ each independently represent a substituted or unsubstituted monovalent aromatic hydrocarbon group, and R⁵ represents a halogen-substituted alkyl group.]

Description

Tire rubber composition and tire

The present invention relates to rubber compositions for tires and tires.

In general, various rubber members that constitute a tire may deteriorate under the influence of the ambient environment such as the presence of ozone, and as the deterioration progresses, cracks and the like may occur. In order to deal with such problems, rubber compositions containing anti-aging agents are often applied to various rubber members constituting tires.
For example, in Patent Document 1 below, a specific quinoline antioxidant and N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine (antiaging agent 6PPD) are selected and blended. It is disclosed that cracks and discoloration of the tire surface can be suppressed by applying the resulting rubber composition to the rubber constituting the surface of the tire.

WO2018/056384

However, the N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine (anti-aging agent 6PPD) used in Patent Document 1 may have an impact on the environment. Considering the possibility of regulation by European regulations in the future, it is desired to use anti-aging agents that have a lower environmental load.

On the other hand, the present inventor has a phenylenediamine moiety similar to the antioxidant 6PPD, but uses an amine-based antioxidant with a specific structure that does not have a double bond other than the phenylenediamine moiety. I came up with However, the present inventors have found that when an amine-based antioxidant having such a specific structure is blended into a rubber composition, premature vulcanization (scorch) occurs, resulting in a problem in workability during kneading of the rubber composition. I found out.

On the other hand, as a means of suppressing premature vulcanization (scorch) of rubber compositions, a technique of using a vulcanization retarder is known. However, as a result of investigation by the present inventors, when a general vulcanization retarder such as N-cyclohexylthiophthalimide is used together with the amine anti-aging agent having the specific structure described above, the vulcanization retarder blooms from the rubber composition. As a result, the adhesiveness (tack) of the rubber composition is lowered, and it has been found that there is a problem in workability during molding of the rubber composition.

Accordingly, an object of the present invention is to solve the above problems and to provide a rubber composition for a tire that achieves both scorch resistance and bloom resistance.
A further object of the present invention is to provide a tire using such a rubber composition and having excellent productivity.

The main structure of the tire rubber composition and tire of the present invention for solving the above problems is as follows.

[1] containing a rubber component, an amine anti-aging agent, and a vulcanization retarder,
The amine antioxidant has the following general formula (1):

[Wherein, R ¹ and R ² are each independently a monovalent saturated hydrocarbon group],
The content of the amine-based antioxidant is 0.1 parts by mass or more with respect to 100 parts by mass of the rubber component,
The vulcanization retarder has the following general formula (2):

[Wherein, R ³ and R ⁴ are each independently a substituted or unsubstituted monovalent aromatic hydrocarbon group, and R ⁵ is a halogen-substituted alkyl group],
A rubber composition for a tire, wherein the content of the vulcanization retarder is 0.005 parts by mass or more with respect to 100 parts by mass of the rubber component.

[2] The rubber composition for tires according to [1], wherein the content of the vulcanization retarder is 0.01 to 3.5 parts by mass with respect to 100 parts by mass of the rubber component.

[3] [1] or [2], wherein R ¹ and R ² in the general formula (1) are each independently a linear or cyclic monovalent saturated hydrocarbon group having 1 to 20 carbon atoms; The rubber composition for tires according to .

[4] The rubber composition for tires according to any one of [1] to [3], wherein the vulcanization retarder has a molecular weight of 300 or more and 800 or less.

[5] The rubber composition for tires according to any one of [1] to [4], wherein the vulcanization retarder has 13 to 30 carbon atoms.

[6] A tire comprising a rubber member made of the tire rubber composition according to any one of [1] to [5].

ADVANTAGE OF THE INVENTION According to this invention, the rubber composition for tires which compatible scorch resistance and bloom resistance can be provided.
Moreover, according to the present invention, it is possible to provide a tire having excellent productivity using such a rubber composition.

The rubber composition for tires and the tire of the present invention are exemplified in detail below based on the embodiments thereof.

<Rubber composition for tires>
The rubber composition for tires of the present invention comprises a rubber component, an amine antioxidant, and a vulcanization retarder. In the rubber composition for tires of the present invention, the amine antioxidant is , the following general formula (1):

[In the formula, R ¹ and R ² are each independently a monovalent saturated hydrocarbon group], and the content of the amine antioxidant is 0 per 100 parts by mass of the rubber component. .1 part by mass or more, and the vulcanization retarder has the following general formula (2):

[Wherein, R ³ and R ⁴ are each independently a substituted or unsubstituted monovalent aromatic hydrocarbon group, and R ⁵ is a halogen-substituted alkyl group], The content of the vulcanization retarder is 0.005 parts by mass or more with respect to 100 parts by mass of the rubber component.

In the rubber composition for tires of the present invention, the amine anti-aging agent represented by the general formula (1) is contained in an amount of 0.1 parts by mass or more per 100 parts by mass of the rubber component, thereby improving the durability of the rubber composition. Ozone resistance can be sufficiently ensured, and in particular, deterioration of elongation at break (EB) and tensile strength (TB) of the aged rubber composition can be suppressed.
Further, in the rubber composition for tires of the present invention, the vulcanization retarder represented by the above general formula (2) is contained in an amount of 0.005 parts by mass or more with respect to 100 parts by mass of the rubber component. Premature vulcanization (scorch) can be suppressed, and workability during kneading of the rubber composition can be improved. In addition, the vulcanization retarder represented by the above general formula (2) is less likely to bloom even when used in combination with the amine antioxidant represented by the above general formula (1). It is possible to sufficiently secure bloom resistance and suppress a decrease in adhesiveness (tack) of the rubber composition.
Therefore, the rubber composition for tires of the present invention can achieve both scorch resistance and bloom resistance while having sufficient ozone resistance, and is excellent in workability during both kneading and molding. .

(rubber component)
The rubber composition for tires of the present invention comprises a rubber component, which provides rubber elasticity to the composition. As the rubber component, diene rubber is preferable, and isoprene skeleton rubber, styrene-butadiene rubber (SBR), butadiene rubber (BR), and chloroprene rubber (CR) are more preferable. Here, the isoprene-skeletal rubber is a rubber having isoprene units as a main skeleton, and specific examples thereof include natural rubber (NR), synthetic isoprene rubber (IR), and the like. When the rubber component contains at least one selected from the group consisting of isoprene skeleton rubber, styrene-butadiene rubber, butadiene rubber, and chloroprene rubber, the rubber composition has excellent rubber elasticity and is more suitable for tire applications. becomes. Further, when the rubber component contains at least one selected from the group consisting of isoprene skeleton rubber, styrene-butadiene rubber, butadiene rubber, and chloroprene rubber, the effect of the present invention (ozone resistance by amine antioxidant improvement effect, improvement effect of scorch resistance and bloom resistance by a vulcanization retarder) tends to appear remarkably. The content of diene rubber such as isoprene skeleton rubber, styrene-butadiene rubber, butadiene rubber and chloroprene rubber in the rubber component is preferably 80% by mass or more, more preferably 90% by mass or more, and may be 100% by mass. The rubber component may be used alone or in a blend of two or more.

(Amine anti-aging agent)
The rubber composition for tires of the present invention contains an amine anti-aging agent, and the amine anti-aging agent is represented by the general formula (1). The amine antioxidant represented by the general formula (1) contains a phenylenediamine moiety like N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine (antioxidant 6PPD). However, it differs from antiaging agent 6PPD in that it has no double bond other than the phenylenediamine moiety. In addition, the amine anti-aging agent represented by the general formula (1) improves the ozone resistance of the rubber composition, and reduces the maintenance rate of elongation at break (EB) and tensile strength (TB) after aging. has the effect of suppressing

In general formula (1) above, R ¹ and R ² are each independently a monovalent saturated hydrocarbon group. R ¹ and R ² may be the same or different, but are preferably the same from the viewpoint of synthesis.

The monovalent saturated hydrocarbon group preferably has 1 to 20 carbon atoms, more preferably 3 to 10 carbon atoms, and particularly preferably 6 and 7 carbon atoms. When the number of carbon atoms in the saturated hydrocarbon group is 20 or less, the number of moles per unit mass becomes large, so that the anti-aging effect becomes large and the ozone resistance of the rubber composition is improved.
From the viewpoint of further improving the ozone resistance of the rubber composition, R ¹ and R ² in the general formula (1) each independently represent a linear or cyclic monovalent saturated hydrocarbon having 1 to 20 carbon atoms. It is preferably a group.

Examples of the monovalent saturated hydrocarbon group include an alkyl group and a cycloalkyl group. The alkyl group may be linear or branched, and the cycloalkyl group may further include an alkyl group as a substituent. etc. may be combined.
Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, 1,2-dimethylbutyl group, 1,3- dimethylbutyl group, 2,3-dimethylbutyl group, n-pentyl group, isopentyl group, neopentyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, 1,2 -dimethylpentyl group, 1,3-dimethylpentyl group, 1,4-dimethylpentyl group, 2,3-dimethylpentyl group, 2,4-dimethylpentyl group, 3,4-dimethylpentyl group, n-hexyl group, Examples include 1-methylhexyl group, 2-methylhexyl group, various octyl groups, various decyl groups, various dodecyl groups, etc. Among these, 1,4-dimethylpentyl group is preferred.
Examples of the cycloalkyl group include a cyclopentyl group, a methylcyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, etc. Among these, a cyclohexyl group is preferred.

Specific examples of the amine antioxidant represented by the general formula (1) include N,N'-bis(1,4-dimethylpentyl)-p-phenylenediamine (antiaging agent 77PD), N, N'-bis(1-ethyl-3-methylpentyl)-p-phenylenediamine, N,N'-dicyclohexyl-p-phenylenediamine (antiaging agent CCPD) and the like, among these, N,N' -Bis(1,4-dimethylpentyl)-p-phenylenediamine (antiaging agent 77PD), N,N'-dicyclohexyl-p-phenylenediamine (antiaging agent CCPD) are preferred, and N,N'-bis(1 ,4-dimethylpentyl)-p-phenylenediamine (antiaging agent 77PD) is particularly preferred. The amine anti-aging agents may be used singly or in combination of two or more.

The content of the amine anti-aging agent is 0.1 parts by mass or more and preferably 11 parts by mass or less with respect to 100 parts by mass of the rubber component. If the content of the amine anti-aging agent is less than 0.1 parts by mass with respect to 100 parts by mass of the rubber component, the ozone resistance of the rubber composition cannot be sufficiently ensured. The reduction in elongation at break (EB) and tensile strength (TB) of the subsequent rubber composition cannot be sufficiently suppressed. Further, when the content of the amine anti-aging agent is 11 parts by mass or less with respect to 100 parts by mass of the rubber component, the adverse effect on rubber physical properties other than ozone resistance (heat buildup, etc.) is reduced, and tire applications is more suitable. From the viewpoint of improving ozone resistance, the content of the amine antioxidant is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, relative to 100 parts by mass of the rubber component. From the viewpoint of further suppressing the influence on rubber physical properties, it is more preferably 10 parts by mass or less, and even more preferably 8 parts by mass or less per 100 parts by mass of the rubber component.

(vulcanization retarder)
The rubber composition for tires of the present invention contains a vulcanization retarder, and the vulcanization retarder is represented by the general formula (2). The vulcanization retarder represented by the general formula (2) has the effect of suppressing premature vulcanization (scorch) of the rubber composition, and the amine anti-aging agent represented by the general formula (1). Even if it is used in combination, it is difficult to bloom. Therefore, by blending the vulcanization retarder of the general formula (2) into the rubber composition, premature vulcanization (scorch) of the rubber composition is suppressed, and the decrease in tackiness of the rubber composition is also suppressed. It is possible to improve the workability during both kneading and molding of the rubber composition.

In general formula (2) above, R ³ and R ⁴ are each independently a substituted or unsubstituted monovalent aromatic hydrocarbon group. R ³ and R ⁴ may be the same or different, but are preferably the same from the viewpoint of synthesis.

The number of carbon atoms in the monovalent aromatic hydrocarbon group is preferably 6-20, more preferably 6-10, and particularly preferably 6. When the number of carbon atoms in the aromatic hydrocarbon group is 20 or less, the number of moles per unit mass increases, so the vulcanization retardation effect increases and the scorch resistance of the rubber composition improves.

Examples of the monovalent aromatic hydrocarbon group include an aryl group and an aralkyl group.
Examples of the aryl group include phenyl group, tolyl group, xylyl group, mesityl group, duryl group, biphenyl group, naphthyl group, anthryl group, terphenyl group, pyrenyl group, phenanthrenyl group and the like. is preferred.
Examples of the aralkyl group include benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group and the like.

A hydrogen atom in the monovalent aromatic hydrocarbon group may or may not be substituted with a substituent. Here, the substituents include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group and tert-butyl group; cyclopentyl group, cyclohexyl group, cycloheptyl group and the like. cycloalkyl group of; vinyl group, 1-propenyl group, allyl group, butenyl group, alkenyl group such as styryl group; methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, isobutoxy group, tert-butoxy group, Alkoxy groups such as pentyloxy group, hexyloxy group, heptyloxy group and octyloxy group; Acyl groups such as acetyl group, propionyl group and butyryl group; Halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom; Methyl chloride a haloalkyl group such as a methyl bromide group, a methyl iodide group, a fluoromethyl group, a difluoromethyl group and a trifluoromethyl group; and a nitro group.

In general formula (2) above, R ⁵ is a halogen-substituted alkyl group (haloalkyl group).
The number of carbon atoms in the halogen-substituted alkyl group is preferably 1 to 10, more preferably 1 to 4, and particularly preferably 1. When the number of carbon atoms in the halogen-substituted alkyl group is 10 or less, the number of moles per unit mass increases, so that the vulcanization retardation effect increases and the scorch resistance of the rubber composition improves.
In the alkyl group substituted with halogen, the number of halogen substitutions is preferably 1 to 10, more preferably 1 to 5, and particularly preferably 3.

Examples of the halogen include fluorine, chlorine, bromine, iodine, etc. Among these, chlorine is preferred.
Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, etc. Among these, methyl group is preferred. .
Further, the halogen-substituted alkyl group specifically includes a fluoromethyl group, a chloromethyl group, a bromomethyl group, a difluoromethyl group, a dichloromethyl group, a trifluoromethyl group, a trichloromethyl group, a fluoroethyl group, and a chloroethyl group. , bromoethyl group and the like, and among these, trichloromethyl group is preferred.

The vulcanization retarder preferably has a molecular weight of 300 or more and 800 or less. When the molecular weight of the vulcanization retarder is 300 or more, the vulcanization retarder is more difficult to bloom, and the bloom resistance of the rubber composition is further improved. Further, when the molecular weight of the vulcanization retarder is 800 or less, the number of moles per unit mass increases, so the vulcanization retarding effect increases, and the scorch resistance of the rubber composition further improves. From the viewpoint of scorch resistance, the molecular weight of the vulcanization retarder is more preferably 700 or less, still more preferably 600 or less, and even more preferably 500 or less.

The vulcanization retarder preferably has 13 to 30 carbon atoms. When the number of carbon atoms in the vulcanization retarder is 13 or more, the vulcanization retarder is more difficult to bloom, and the bloom resistance of the rubber composition is further improved. Further, when the number of carbon atoms in the vulcanization retarder is 30 or less, the number of moles per unit mass increases, so the vulcanization retarding effect increases, and the scorch resistance of the rubber composition further improves. From the viewpoint of scorch resistance, the number of carbon atoms in the vulcanization retarder is preferably 25 or less, still more preferably 20 or less, and even more preferably 15 or less.

Specific examples of the vulcanization retarder represented by the general formula (2) include N-phenyl-N-(monochloromethylthio)benzenesulfonamide, N-phenyl-N-(dichloromethylthio)benzenesulfonamide, N -phenyl-N-(trichloromethylthio)benzenesulfonamide, N-phenyl-N-(trichloroethylthio)benzenesulfonamide, N-phenyl-N-(trichloropropylthio)benzenesulfonamide, N-phenyl-N-( Monochloromethylthio)toluenesulfonamide, N-phenyl-N-(dichloromethylthio)toluenesulfonamide, N-phenyl-N-(trichloromethylthio)toluenesulfonamide, etc. Among these, N-phenyl-N-( Trichloromethylthio)benzenesulfonamide (also called "N-phenyl-N-(trichloromethylsulfenyl)-benzenesulfonamide") is preferred. The vulcanization retarders may be used singly or in combination of two or more.

The content of the vulcanization retarder is 0.005 parts by mass or more, preferably 0.01 parts by mass or more, and preferably 3.5 parts by mass or less with respect to 100 parts by mass of the rubber component. If the content of the vulcanization retarder is less than 0.005 parts by mass with respect to 100 parts by mass of the rubber component, premature vulcanization (scorch) of the rubber composition cannot be sufficiently suppressed, while 0.01 parts by mass If it is above, it is possible to further suppress premature vulcanization (scorch) of the rubber composition, and further improve the scorch resistance of the rubber composition. Further, when the content of the vulcanization retarder is 3.5 parts by mass or less with respect to 100 parts by mass of the rubber component, the vulcanization retarder becomes more difficult to bloom, and the bloom resistance of the rubber composition is further improved. improves. When the content of the vulcanization retarder is 0.01 to 3.5 parts by mass with respect to 100 parts by mass of the rubber component, both scorch resistance and bloom resistance can be achieved at a high level.

(Quinoline anti-aging agent)
The rubber composition for tires of the present invention may contain a quinoline antioxidant. The quinoline anti-aging agent is an anti-aging agent having a quinoline moiety or a derivative thereof (such as a dihydroquinoline moiety). The quinoline anti-aging agent has the effect of improving the ozone resistance of the rubber composition.

The quinoline antioxidant preferably has a dihydroquinoline moiety, more preferably a 1,2-dihydroquinoline moiety.
Specific examples of the quinoline antioxidant include a polymer of 2,2,4-trimethyl-1,2-dihydroquinoline (antioxidant TMDQ), 6-ethoxy-2,2,4-trimethyl-1 ,2-dihydroquinoline, 6-anilino-2,2,4-trimethyl-1,2-dihydroquinoline and the like.
The quinoline antioxidant preferably contains a polymer of 2,2,4-trimethyl-1,2-dihydroquinoline (antiaging agent TMDQ). A quinoline anti-aging agent containing a polymer of 2,2,4-trimethyl-1,2-dihydroquinoline is said to be highly effective in improving the ozone resistance of a rubber composition, and is less likely to discolor the rubber composition. It also has advantages.
The polymer of 2,2,4-trimethyl-1,2-dihydroquinoline includes dimers, trimers and tetramers of 2,2,4-trimethyl-1,2-dihydroquinoline. mentioned.

The content of the quinoline antioxidant is preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the rubber component. When the content of the quinoline antioxidant is 0.1 parts by mass or more with respect to 100 parts by mass of the rubber component, the ozone resistance of the rubber composition is further improved. On the other hand, when the content of the quinoline anti-aging agent is 5 parts by mass or less with respect to 100 parts by mass of the rubber component, it is possible to suppress adverse effects on rubber physical properties (heat buildup, etc.) other than ozone resistance. , more suitable for tire applications. From the viewpoint of ozone resistance, the content of the quinoline antioxidant is preferably 0.3 parts by mass or more, more preferably 0.5 parts by mass or more, with respect to 100 parts by mass of the rubber component. From the viewpoint of influence on rubber physical properties, it is preferably 4 parts by mass or less, more preferably 3 parts by mass or less per 100 parts by mass of the rubber component.

(wax)
The rubber composition for tires of the present invention may further contain wax. When the rubber composition contains wax, the ozone resistance of the rubber composition is further improved.
Examples of the wax include paraffin wax and microcrystalline wax.
The content of the wax is preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the rubber component. When the wax content is 0.1 parts by mass or more with respect to 100 parts by mass of the rubber component, the ozone resistance of the rubber composition is further improved. Further, when the wax content is 5 parts by mass or less with respect to 100 parts by mass of the rubber component, the effect on rubber physical properties other than ozone resistance is small. From the viewpoint of ozone resistance, the content of the wax is more preferably 0.5 parts by mass or more, and even more preferably 1 part by mass or more, with respect to 100 parts by mass of the rubber component. From the viewpoint of influence, it is more preferably 4 parts by mass or less, and even more preferably 3 parts by mass or less with respect to 100 parts by mass of the rubber component.

(sulfur)
The tire rubber composition of the present invention preferably contains sulfur. When the rubber composition contains sulfur, it becomes vulcanizable, and the durability (in particular, elongation at break (EB) and tensile strength (TB)) of the rubber composition is improved.
As the sulfur, various types of sulfur can be used, but ordinary sulfur (soluble sulfur (powder sulfur), etc.) is preferable to insoluble sulfur, and oil treated sulfur, etc. are also preferable. Here, insoluble sulfur is sulfur insoluble in carbon disulfide (amorphous polymeric sulfur), and soluble sulfur (powder sulfur) is sulfur soluble in carbon disulfide.
The sulfur content is preferably in the range of 0.1 to 10 parts by mass, more preferably in the range of 1 to 5 parts by mass, per 100 parts by mass of the rubber component. If the sulfur content is 0.1 parts by mass or more per 100 parts by mass of the rubber component, the durability of the vulcanized rubber can be ensured, and if it is 10 parts by mass or less per 100 parts by mass of the rubber component , sufficient rubber elasticity can be ensured.

(others)
The rubber composition for tires of the present invention may contain, in addition to the aforementioned rubber component, amine-based anti-aging agent, vulcanization retarder, quinoline-based anti-aging agent, wax, and sulfur, if necessary, the rubber industry. Various components commonly used in, for example, fillers (silica, carbon black, calcium carbonate, etc.), silane coupling agents, softeners, processing aids, resins, surfactants, organic acids (stearic acid, etc.), oxidation Zinc (zinc white), a vulcanization accelerator, a vulcanizing agent other than sulfur, and the like may be appropriately selected and contained within a range that does not impair the object of the present invention. Commercially available products can be suitably used as these compounding agents.
In addition, the amine anti-aging agent represented by the general formula (1) may be supported on any carrier. For example, the amine anti-aging agent represented by the above general formula (1) may be supported on inorganic fillers such as silica and calcium carbonate.
Moreover, the amine anti-aging agent represented by the general formula (1) may form a masterbatch together with the rubber component. Here, the rubber component used in forming the masterbatch is not particularly limited, and may be diene rubber such as natural rubber (NR), ethylene-propylene-diene rubber (EPDM), or the like. .
Moreover, the amine anti-aging agent represented by the general formula (1) may be a salt with an organic acid. Here, the organic acid used for forming the salt is not particularly limited, but stearic acid and the like can be mentioned.

(Method for producing rubber composition)
The method for producing the rubber composition is not particularly limited. It can be produced by kneading, heating, extruding, or the like. Further, vulcanized rubber can be obtained by vulcanizing the obtained rubber composition.

The kneading conditions are not particularly limited, and various conditions such as the input volume of the kneading device, the rotation speed of the rotor, the ram pressure, the kneading temperature, the kneading time, the type of the kneading device, etc. It can be selected as appropriate. Examples of the kneading device include Banbury mixers, intermixes, kneaders, rolls, etc., which are usually used for kneading rubber compositions.

There are no particular restrictions on the heating conditions, and various conditions such as the heating temperature, heating time, and heating device can be appropriately selected according to the purpose. Examples of the heating device include a heating roll machine or the like which is usually used for heating the rubber composition.

The extrusion conditions are also not particularly limited, and various conditions such as extrusion time, extrusion speed, extrusion equipment, and extrusion temperature can be appropriately selected according to the purpose. Examples of the extrusion device include an extruder or the like that is usually used for extrusion of a rubber composition. The extrusion temperature can be determined appropriately.

There are no particular restrictions on the vulcanization apparatus, method, conditions, etc., and they can be appropriately selected according to the purpose. As a vulcanization apparatus, a molding vulcanizer with a mold used for vulcanization of a rubber composition can be used. As a vulcanization condition, the temperature is, for example, about 100 to 190.degree.

<Tire>
A tire of the present invention is characterized by comprising a rubber member made of the rubber composition for a tire described above. Since the tire of the present invention includes a rubber member made of the rubber composition for tires, it has excellent productivity. In addition, the tire of the present invention has excellent ozone resistance and excellent durability after aging. Furthermore, the tire of the invention also has the advantage of being environmentally friendly.
Suitable examples of rubber members to which the tire rubber composition is applied include side rubbers, tread rubbers, inner liners, and the like, which constitute the tire surface. The rubber member to which the above rubber composition for tires is applied may be a rubber member that constitutes the inside of a tire. is mentioned.

Depending on the type of tire to be applied, the tire of the present invention may be obtained by vulcanizing after molding using an unvulcanized rubber composition, or using a semi-vulcanized rubber that has undergone a pre-vulcanization step or the like. After molding, it may be obtained by further vulcanization. The tire of the present invention is preferably a pneumatic tire, and the gas to be filled in the pneumatic tire may be normal air or oxygen partial pressure-adjusted air, or an inert gas such as nitrogen, argon, or helium. can be used.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

<Preparation of rubber composition>
Rubber compositions were produced according to the formulations shown in Tables 1 and 2.

*1 NR: Natural rubber *2 BR: Butadiene rubber, cis-1,4 bond content = 96% by mass or more *3 Carbon black: Asahi Carbon Co., Ltd., trade name “Asahi #65”
*4 Wax: Microcrystalline wax, the total amount of "Ozoace 0280" (trade name) manufactured by Nippon Seiro Co., Ltd. and "Ozoace 0701" (trade name) manufactured by Nippon Seiro Co., Ltd. *5 Anti-aging agent 6PPD: General formula (1) one of R ¹ and R ² in is an unsaturated hydrocarbon group (phenyl group), N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine, Sumitomo Chemical Manufactured by Co., Ltd., trade name “Antigen 6C”
^* 6 Antioxidant 77PD: An amine antioxidant, N,N'-bis(1 ^, 4-dimethylpentyl)-p-phenylenediamine, manufactured by EASTMAN, trade name “Santoflex 77PD”
* 7 Vulcanization retarder A: N-cyclohexylthiophthalimide, manufactured by Toray Fine Chemicals Co., Ltd., trade name "Retarder CTP"
*8 Vulcanization retarder B: A vulcanization retarder in which ^R3 and ^R4 in the general formula (2) are aromatic hydrocarbon groups (phenyl group) and ^R5 is a halogen-substituted alkyl group (trichloromethyl group). Sulfur retardant, N-phenyl-N-(trichloromethylsulfenyl)-benzenesulfonamide, manufactured by LANXESS Corporation, trade name "Vulkalent E/C"
*9 Anti-aging agent TMDQ: Quinoline anti-aging agent, 2,2,4-trimethyl-1,2-dihydroquinoline polymer *10 Stearic acid: NOF Corporation, trade name “Kirijirushi stearic acid”
*11 Sulfur: Hosoi Chemical Industry Co., Ltd., product name “HK200-5”, 5% oil total amount containing at least

<Evaluation>
The scorch time and tackiness of the obtained rubber composition were evaluated by the following methods. Table 2 shows the results.

(1) Scorch time The scorch time was measured at 130°C according to JIS-K6300-1.
The larger the scorch time value, the less likely rubber scorching occurs, the better the scorch resistance, and the better the processing stability.
Taking the scorch time of the rubber composition obtained in Comparative Example 1 as 100, the relative value of the scorch time was expressed as an index. Table 2 shows the results.

(2) Tackiness The obtained tire rubber composition was formed into a sheet-like sample (thickness: 2 mm) in an unvulcanized state, left to stand for 4 days, and then evaluated for adhesiveness in the unvulcanized state. . The evaluation was performed at room temperature using a pick-up type tackiness meter (Picmatack meter manufactured by Toyo Seiki Co., Ltd.). The evaluation was described in the column of "tackiness" as an index with the value of Comparative Example 2 as 100. The larger the index, the higher the tackiness (adhesive strength) and the better the workability.

From the results in Table 2, it can be seen that the rubber compositions of each example are excellent in both scorch time and tackiness. In addition, the rubber composition of each example has high tackiness, indicating that it is excellent in bloom resistance.

Claims

including a rubber component, an amine anti-aging agent, and a vulcanization retarder,
The amine antioxidant has the following general formula (1):

[Wherein, R 1 and R 2 are each independently a monovalent saturated hydrocarbon group],
The content of the amine-based antioxidant is 0.1 parts by mass or more with respect to 100 parts by mass of the rubber component,
The vulcanization retarder has the following general formula (2):

[Wherein, R 3 and R 4 are each independently a substituted or unsubstituted monovalent aromatic hydrocarbon group, and R 5 is a halogen-substituted alkyl group],
A rubber composition for a tire, wherein the content of the vulcanization retarder is 0.005 parts by mass or more with respect to 100 parts by mass of the rubber component.
The rubber composition for tires according to claim 1, wherein the content of the vulcanization retarder is 0.01 to 3.5 parts by mass with respect to 100 parts by mass of the rubber component.
The tire according to claim 1 or 2, wherein R 1 and R 2 in the general formula (1) are each independently a linear or cyclic monovalent saturated hydrocarbon group having 1 to 20 carbon atoms. rubber composition.
The rubber composition for tires according to any one of claims 1 to 3, wherein the vulcanization retarder has a molecular weight of 300 or more and 800 or less.
The rubber composition for tires according to any one of claims 1 to 4, wherein the vulcanization retarder has 13 to 30 carbon atoms.
A tire comprising a rubber member made of the tire rubber composition according to any one of claims 1 to 5.