JP6552454B2 - Rubber composition for tire and pneumatic tire - Google Patents

Description

The present invention relates to a rubber composition for a tire and a pneumatic tire using the same.

Since a tire for an automobile uses a rubber composition made of natural rubber and diene based synthetic rubber as a raw material, there is a possibility that a crack may occur due to the progress of deterioration in the presence of ozone. In order to suppress the occurrence and progress of cracks in the presence of ozone, for example, an antioxidant (N- (1,3-dimethylbutyl) -N′-phenyl-p-phenylenediamine (6PPD), poly (2 , 2,4-trimethyl-1,2-) dihydroquinoline (TMDQ), etc.) and additives such as petroleum waxes are blended in the rubber composition.

The above-mentioned anti-aging agent and petroleum wax function to protect the rubber from ozone by migrating (blooming) from the vulcanized rubber to the surface of the rubber such as a tire. However, excessive blooming of the anti-aging agent and petroleum wax in a short period of time causes white discoloration. In addition, an antiaging agent that has been deteriorated by ozone causes browning, and similarly, excessive blooming leads to stronger browning. Further, when the wax or the like deposited on the tire surface is uneven, light irregular reflection occurs, brown discoloration due to the deteriorated anti-aging agent becomes more conspicuous, and the tire gloss is lost.

Patent Document 1 describes that deterioration of the appearance of a tire can be prevented by blending an ether type nonionic surfactant of polyoxyethylene. However, there is room for improvement in terms of improving the color fastness and the appearance of the tire while maintaining or improving the good fuel economy and the abrasion resistance.

Japanese Patent Laid-Open No. 05-194790

The present invention aims at providing discoloration resistance, a rubber composition for a tire can improve the appearance of the tire, and a pneumatic tire using the same.

In the present invention, the content of styrene butadiene rubber is 30 to 100 mass% in 100 mass% of the rubber component, contains a pluronic nonionic surfactant and sulfur, and the total content of carbon black and silica is rubber It is related with the rubber composition for tires which is 20-140 mass parts with respect to 100 mass parts of components.

The tire rubber composition preferably includes 0.1 to 5.0 parts by mass of the pluronic-type nonionic surfactant with respect to 100 parts by mass of the rubber component.

The tire rubber composition preferably contains 0.1 to 6.0 parts by mass of the sulfur with respect to 100 parts by mass of the rubber component.

The tire rubber composition is preferably used as a tread rubber composition.

The present invention also relates to a pneumatic tire having a tire member produced using the rubber composition.

The tire member is preferably a tread.

According to the present invention, the content of the styrene butadiene rubber is 30 to 100% by mass in 100% by mass of the rubber component, and includes the pluronic-type nonionic surfactant and sulfur, and the total content of carbon black and silica is Since the rubber composition for a tire is 20 to 140 parts by mass with respect to 100 parts by mass of the rubber component, the color resistance and the appearance of the tire can be maintained while maintaining or improving good low fuel consumption and abrasion resistance. It is possible to provide a pneumatic tire that can be improved and has excellent fuel economy, abrasion resistance, discoloration resistance and tire appearance.

The rubber composition for tires of the present invention has a styrene butadiene rubber content of 30 to 100% by mass in 100% by mass of a rubber component, contains a pluronic type nonionic surfactant and sulfur, and contains carbon black and silica. The total content is 20 to 140 parts by mass with respect to 100 parts by mass of the rubber component.

In the present invention, in a rubber composition in which a specific rubber component, a specific amount of filler (carbon black and / or silica), and sulfur are blended, a wax or the like can be obtained by blending a specific nonionic surfactant. The unevenness of the tire surface (bloom layer) formed by precipitation is smoothed and irregular reflection of light is suppressed. Thereby, discoloration resistance, such as reducing the above-mentioned brown discoloration and white discoloration, is also improved. In addition, the tire appearance is improved by giving the tire surface an appropriate black appearance and gloss. At the same time, good fuel efficiency and wear resistance can be maintained or improved.

Moreover, as a result of blending the specific non-ionic surfactant with the rubber composition, the compatibility between the rubber composition and the specific non-ionic surfactant is appropriately controlled, as described above, It is presumed that the tire appearance can be improved while maintaining or improving the low fuel consumption and wear resistance.

In the rubber composition of the present invention, a specific amount of styrene butadiene rubber (SBR) is used. As a result, good fuel economy and wear resistance can be obtained, and the bloom of the nonionic surfactant can be suitably controlled, and the effects of the present invention can be obtained satisfactorily.
Specifically, the content of SBR in 100% by mass of the rubber component is 30% by mass or more, preferably 40% by mass or more, more preferably 50% by mass or more, and may be 100% by mass. When other rubber components are also used, the content is preferably 90% by mass or less. If the SBR content is less than 30% by mass, fuel economy and wear resistance cannot be sufficiently obtained.

SBR is not particularly limited, and those generally used in the tire industry, such as emulsion-polymerized styrene butadiene rubber (E-SBR) and solution-polymerized styrene butadiene rubber (S-SBR), can be appropriately selected according to use conditions and purposes. . These may be used alone or in combination of two or more. For example, SL series manufactured by JSR Corp., Tuffden series manufactured by Asahi Kasei Chemicals Corp., Asaprene E15 manufactured by Asahi Kasei Chemicals Corp., Nipol series manufactured by Nippon Zeon Co., Ltd., etc. can be used.

The styrene content of SBR is preferably 5% by mass or more, more preferably 10% by mass or more, and still more preferably 15% by mass or more. The styrene content is preferably 60% by mass or less, more preferably 50% by mass or less, still more preferably 40% by mass or less, particularly preferably 30% by mass or less. When the styrene content is within the above range, the effect of the present invention can be more suitably obtained.
In the present invention, the styrene content of SBR is calculated by H ¹ -NMR measurement.

In the present invention, at least one rubber selected from the group consisting of butadiene rubber (BR), natural rubber (NR), and isoprene rubber (IR) may be used together with SBR. These may be used alone or in combination of two or more. Among them, NR and BR are preferable because the effect of the present invention (particularly, abrasion resistance) is more suitably obtained, and it is more preferable to use BR together with SBR.

As NR, for example, those common in the tire industry, such as SIR20, RSS # 3 and TSR20, can be used. These may be used alone or in combination of two or more.

The IR is not particularly limited, and those commonly used in the tire industry can be used. These may be used alone or in combination of two or more.

It does not specifically limit as BR, For example, high cis content BR, such as BR730 made by JSR Co., Ltd., BR1220 made by Nippon Zeon Co., Ltd., BR130 B made by Ube Industries, Ltd., BR150B, BR710 etc. can be used. . These may be used alone or in combination of two or more. Among them, the cis content of BR is preferably 90% by mass or more because the effects of the present invention can be more suitably obtained.

When the rubber composition contains BR, the content of BR in 100% by mass of the rubber component is preferably 15% by mass or more, and more preferably 25% by mass or more. The BR content is preferably 55% by mass or less, more preferably 45% by mass or less. The effect of this invention is acquired more suitably as content of BR is in the said range.

There are no particular limitations on rubber components that can be used other than SBR, BR, NR, and IR, and styrene isoprene butadiene rubber (SIBR), chloroprene rubber (CR), acrylonitrile butadiene rubber (NBR), ethylene propylene diene rubber (EPDM), Examples include diene rubbers such as butyl rubber (IIR) and halogenated butyl rubber (X-IIR). A rubber component may be used independently and may use 2 or more types together.

（式（Ｉ）中、ａ、ｂ、ｃは整数を表す。） In the present invention, a pluronic nonionic surfactant is used. Pluronic type nonionic surfactant is also called polyoxyethylene polyoxypropylene glycol, polyoxyethylene polyoxypropylene block polymer, polypropylene glycol ethylene oxide adduct, and is generally nonionic represented by the following formula (I) It is a surfactant. As represented by the following formula (I), the pluronic-type nonionic surfactant has a hydrophilic group composed of an ethylene oxide structure on both sides, and is composed of a propylene oxide structure so as to be sandwiched between the hydrophilic groups. Has a hydrophobic group.

(In formula (I), a, b, and c represent integers.)

The degree of polymerization of the polypropylene oxide block of the pluronic-type nonionic surfactant (b in the above formula (I)) and the addition amount of polyethylene oxide (a + c in the above formula (I)) are not particularly limited, and the use conditions, purpose, etc. It can be selected appropriately according to The higher the proportion of polypropylene oxide blocks, the higher the affinity to rubber and the slower the transition to the rubber surface tends to be. Among them, the degree of polymerization of the polypropylene oxide block (b in the above formula (I)) is preferably 100, because the bloom of the nonionic surfactant can be suitably controlled and the effects of the present invention can be more suitably obtained. Or less, more preferably 10 to 70, still more preferably 10 to 60, particularly preferably 20 to 60, and most preferably 20 to 45. Similarly, the addition amount of polyethylene oxide (a + c of the above formula (I) is preferably 100 or less, more preferably 3 to 65, still more preferably 5 to 55, particularly preferably 5 to 40, most preferably 10-40. When the polymerization degree of the polypropylene oxide block and the addition amount of polyethylene oxide are in the above ranges, the bloom of the nonionic surfactant can be suitably controlled, and the effect of the present invention can be more suitably obtained.

As Pluronic type nonionic surfactants, Pluronic series manufactured by BASF Japan Ltd., New Pole PE series manufactured by Sanyo Chemical Industries, Ltd., Adeka Pluronic L or F series manufactured by Asahi Denka Kogyo Co., Ltd., first There may be mentioned Epan series manufactured by Kogyo Seiyaku Co., Ltd., Pronon series manufactured by NOF Corporation, or Unilobe. These may be used alone or in combination of two or more.

The content of the pluronic nonionic surfactant is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, and still more preferably 0.6 parts by mass or more with respect to 100 parts by mass of the rubber component. is there. If the amount is less than 0.1 parts by mass, the effects of the present invention may not be sufficiently obtained. The content is preferably 5.0 parts by mass or less, more preferably 4.0 parts by mass or less, and still more preferably 3.0 parts by mass or less. If it exceeds 5.0 parts by mass, handling stability, crack resistance, ozone resistance and discoloration resistance may be deteriorated.

In the present invention, sulfur is used to form an appropriate cross-linked chain in the polymer chain. Thereby, the bloom of the said nonionic surfactant can be controlled suitably and the effect of this invention is acquired favorably. Sulfur includes powdery sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersible sulfur, soluble sulfur and the like generally used in the rubber industry. These may be used alone or in combination of two or more.

The sulfur content is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and still more preferably 1.0 parts by mass or more with respect to 100 parts by mass of the rubber component. There exists a possibility that the effect of this invention may not fully be acquired as it is less than 0.1 mass part. The sulfur content is preferably 6.0 parts by mass or less, more preferably 5.0 parts by mass or less, still more preferably 4.0 parts by mass or less, particularly preferably 3.0 parts by mass or less, most preferably 2. It is 5 parts by mass or less. If it exceeds 6.0 parts by mass, fuel economy and wear resistance may be deteriorated.

In the present invention, as the vulcanizing agent, in addition to sulfur, an alkylphenol-sulfur chloride condensate (for example, Tackiroll V200 manufactured by Taoka Chemical Industry Co., Ltd.) may be used.

In the present invention, the total content of carbon black and silica is a specific amount. Thereby, good reinforcement can be obtained, and good fuel economy and wear resistance can be obtained. In addition, the bloom of the nonionic surfactant can be suitably controlled, and the effects of the present invention can be favorably obtained.
Specifically, the total content of carbon black and silica is 20 parts by mass or more, preferably 30 parts by mass or more, more preferably 40 parts by mass or more, still more preferably 55 parts by mass with respect to 100 parts by mass of the rubber component As described above, particularly preferably 65 parts by mass or more. The total content is 140 parts by mass or less, preferably 130 parts by mass or less, and more preferably 105 parts by mass or less. If the total content is less than 20 parts by mass, the reinforcing property tends to deteriorate, and if the total content exceeds 140 parts by mass, the fuel economy and the abrasion resistance tend to be deteriorated.

In the present invention, either carbon black or silica may be used alone, or both may be used in combination.

Examples of carbon black include GPF, FEF, HAF, ISAF, and SAF, but are not particularly limited. These may be used alone or in combination of two or more.

Nitrogen adsorption specific surface area _(N 2 SA) of carbon black is preferably not less than ^{20 m} 2 / g, more preferably at least ^{50 m} 2 / g. If it is less than 20 m < ² > / g, there exists a possibility that sufficient reinforcement may not be acquired. It said _N 2 SA is preferably 180 m ² / g or less, more preferably 120 m ² / g, more preferably ^90m 2 / g or less, ^{80 m} 2 / g or less is particularly preferred. If it exceeds 180 m ² / g, it will be difficult to disperse, and fuel economy and abrasion resistance will tend to deteriorate.
Incidentally, _N 2 SA of carbon black, JIS K 6217-2: determined by 2001.

50 ml / 100 g or more is preferable and, as for the dibutyl phthalate oil absorption amount (DBP) of carbon black, 80 ml / 100 g or more is more preferable. If it is less than 50 ml / 100 g, sufficient reinforcement may not be obtained. In addition, DBP of carbon black is preferably 200 ml / 100 g or less, more preferably 135 ml / 100 g or less, and still more preferably 115 ml / 100 g or less. When it exceeds 200 ml / 100 g, it becomes difficult to disperse, and fuel economy and abrasion resistance tend to deteriorate.
In addition, DBP of carbon black is measured based on JISK6217-4: 2001.

When the rubber composition contains carbon black, the content of carbon black is preferably 2 parts by mass or more, more preferably 3 parts by mass or more with respect to 100 parts by mass of the rubber component. If the amount is less than 2 parts by mass, sufficient reinforcement may not be obtained. The content is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, still more preferably 20 parts by mass or less, and particularly preferably 15 parts by mass or less. If it exceeds 50 parts by mass, fuel economy and wear resistance tend to deteriorate. In addition, although it is feared that the fuel consumption and the abrasion resistance are deteriorated by blending a large amount of carbon black, in the present invention, the fuel consumption and the abrasion resistance are obtained by setting the content of the carbon black to a specific amount. It is possible to suppress the deterioration of sex.

The silica is not particularly limited, and examples thereof include dry process silica (anhydrous silicic acid), wet process silica (hydrous silicic acid) and the like. These may be used alone or in combination of two or more. Of these, wet-process silica is preferred because it has many silanol groups.

The nitrogen adsorption specific surface area (N ₂ SA) of silica is preferably 50 m ² / g or more, more preferably 100 m ² / g or more, and further preferably 150 m ² / g or more. If it is less than 50 m < ² > / g, there exists a tendency for low-fuel-consumption property and abrasion resistance to fall. The N ₂ SA is preferably 250 m ² / g or less, more preferably 210 m ² / g or less. When it exceeds 250 m ² / g, it becomes difficult to disperse, and there is a tendency that low fuel consumption and wear resistance deteriorate.
The _N 2 SA of silica is a value determined by the BET method in accordance with ASTM D3037-93.

When the rubber composition contains silica, the content of silica is preferably 10 parts by mass or more, more preferably 30 parts by mass or more, still more preferably 50 parts by mass or more, based on 100 parts by mass of the rubber component Preferably it is 60 mass parts or more. The silica content is preferably 140 parts by mass or less, more preferably 120 parts by mass or less, and still more preferably 100 parts by mass or less. When the content of silica exceeds 140 parts by mass, fuel economy, wear resistance, discoloration resistance, and tire appearance tend to deteriorate. By making the content of silica within the above range, the appearance of the tire can be further improved and a reinforcing effect can be obtained.

The rubber composition of the present invention preferably contains a silane coupling agent together with the silica when the silica is blended.
As the silane coupling agent, any silane coupling agent conventionally used in combination with silica can be used in the rubber industry, and examples thereof include sulfide systems such as bis (3-triethoxysilylpropyl) disulfide, 3- Mercapto type such as mercaptopropyltrimethoxysilane, vinyl type such as vinyltriethoxysilane, amino type such as 3-aminopropyltriethoxysilane, glycidoxy type of γ-glycidoxypropyltriethoxysilane, 3-nitropropyltrimethoxy Examples thereof include nitro compounds such as silane and chloro compounds such as 3-chloropropyltrimethoxysilane. These may be used alone or in combination of two or more. Among them, sulfides are preferable, and bis (3-triethoxysilylpropyl) disulfide is more preferable.

When the rubber composition contains a silane coupling agent, the content of the silane coupling agent is preferably 2 parts by mass or more, more preferably 5 parts by mass or more, with respect to 100 parts by mass of silica. If it is less than 2 parts by mass, fuel economy and wear resistance tend to be lowered. The content of the silane coupling agent is preferably 20 parts by mass or less, more preferably 15 parts by mass or less. When it exceeds 20 parts by mass, there is a tendency that an effect commensurate with the increase in cost cannot be obtained.

In the present invention, it is preferable to add a wax in order to suppress the occurrence and progress of cracks due to ozone. In the present invention, as described above, the unevenness of the tire surface (bloom layer) formed by precipitation of wax or the like can be smoothed even if the wax is blended, and irregular reflection of light is suppressed. White discoloration can be reduced. In addition, the tire appearance is improved by giving the tire surface an appropriate black appearance and gloss. Furthermore, in this invention, since it is a specific rubber composition, favorable low fuel consumption and abrasion resistance are maintained or improved.

The wax is not particularly limited, and examples thereof include petroleum waxes, natural waxes and the like, and synthetic waxes obtained by purifying or chemically treating a plurality of waxes can also be used. These waxes may be used alone or in combination of two or more.

Examples of petroleum waxes include paraffin wax and microcrystalline wax. Natural waxes are not particularly limited as long as they are waxes derived from non-petroleum resources. For example, plant waxes such as candelilla wax, carnauba wax, wax wax, rice wax, jojoba wax; beeswax, lanolin, sperm wax, etc. Animal waxes; mineral waxes such as ozokerite, ceresin, petrolactam; and purified products thereof.

When the rubber composition contains a wax, the content of the wax is preferably 0.5 parts by mass or more, more preferably 1.0 part by mass or more with respect to 100 parts by mass of the rubber component. If the amount is less than 0.5 parts by mass, sufficient ozone resistance may not be obtained. The content of the wax is preferably 12 parts by mass or less, more preferably 10 parts by mass or less, and still more preferably 5.0 parts by mass or less. If it exceeds 12 parts by mass, no further improvement in the resistance to ozone can be expected, and the cost may be increased.

The rubber composition of the present invention may contain oil. By blending the oil, the processability is improved, the tire can be made flexible, and the effect of the present invention is better obtained. As the oil, for example, process oil, vegetable oil, or a mixture thereof can be used. As the process oil, for example, paraffin-based process oil, aroma-based process oil, naphthene-based process oil and the like can be used. Specific examples of the paraffinic process oil include PW-32, PW-90, PW-150, and PS-32 manufactured by Idemitsu Kosan Co., Ltd. Moreover, as an aroma system process oil, AC-12, AC-460, AH-16, AH-24, AH-58 etc. made from Idemitsu Kosan Co., Ltd. specifically, etc. are mentioned. As vegetable oil, castor oil, cotton seed oil, linseed oil, rapeseed oil, soybean oil, palm oil, coconut oil, peanut oil, peanut oil, pine oil, pine tar, tall oil, corn oil, corn oil, vegetable oil, sesame oil, Examples include olive oil, sunflower oil, palm kernel oil, camellia oil, jojoba oil, macadamia nut oil, and tung oil. These may be used alone or in combination of two or more. Among these, paraffinic process oil is preferable because the effects of the present invention can be suitably obtained.

When the rubber composition contains an oil, the content of oil is preferably 1.0 parts by mass or more, more preferably 5.0 parts by mass or more, still more preferably 10 parts by mass with respect to 100 parts by mass of the rubber component. Part or more, particularly preferably 15 parts by weight or more. The oil content is preferably 60 parts by mass or less, more preferably 40 parts by mass or less, and still more preferably 30 parts by mass or less. By setting the content of the oil that blooms on the surface of the tire within the above range, the bloom of the nonionic surfactant can be suitably controlled, and the effect of the present invention can be more suitably obtained. Note that when the oil content exceeds 60 parts by mass, fuel efficiency tends to deteriorate.

The rubber composition of the present invention preferably contains an antiaging agent in order to suppress the occurrence and progress of cracks due to ozone. In the present invention, even when an anti-aging agent is blended, as described above, while maintaining or improving good fuel economy and wear resistance, browning and white discoloration can be reduced, discoloration resistance and tire appearance can be reduced. It can improve.

The anti-aging agent is not particularly limited. For example, naphthylamines, quinolines, diphenylamines, p-phenylenediamines, hydroquinone derivatives, phenols (monophenols, bisphenols, trisphenols, polyphenols), thiobisphenols There may be mentioned, for example, those based on benzimidazoles, thioureas, phosphorous acids and organic thioacids. These may be used alone or in combination of two or more. Of these, p-phenylenediamine is preferable because ozone resistance is good and the effects of the present invention can be obtained more suitably.

As the p-phenylenediamine anti-aging agent, N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine, N-isopropyl-N'-phenyl-p-phenylenediamine, N-1, 4-dimethylpentyl-N'-phenyl-p-phenylenediamine, N, N'-diphenyl-p-phenylenediamine, N, N'-di-2-naphthyl-p-phenylenediamine, N-cyclohexyl-N'- Phenyl-p-phenylenediamine, N, N'-bis (1-methylheptyl) -p-phenylenediamine, N, N'-bis (1,4-dimethylpentyl) -p-phenylenediamine, N, N'- Bis (1-ethyl-3-methylpentyl) -p-phenylenediamine, N-4-methyl-2-pentyl-N′-phenyl-p-phenylene Amine, N, N'-diaryl -p- phenylenediamine, hindered mistakes aryl -p- phenylenediamine, phenyl hexyl -p- phenylenediamine, and the like phenyloctyl -p- phenylenediamine. These may be used alone or in combination of two or more. Among them, N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylene is preferable because the ozone resistance performance is good, the effects of the present invention are more suitably obtained, and the economy is also excellent. Diamine is more preferred.

When the rubber composition contains an antioxidant, the content of the antioxidant is preferably 0.3 parts by mass or more, more preferably 0.5 parts by mass or more, per 100 parts by mass of the rubber component. Preferably it is 1.0 mass part or more. If the amount is less than 0.3 parts by mass, sufficient ozone resistance may not be obtained. The content of the anti-aging agent is preferably 10 parts by mass or less, more preferably 6.0 parts by mass or less. If the amount is more than 10 parts by mass, the amount of anti-aging agent bloom may increase and the appearance of the tire may be deteriorated.

The rubber composition of the present invention preferably contains a vulcanization accelerator. Examples of the vulcanization accelerator include sulfenamide, thiazole, thiuram, thiourea, guanidine, dithiocarbamic acid, aldehyde-amine or aldehyde-ammonia, imidazoline, or xanthate vulcanization accelerators. Etc. These vulcanization accelerators may be used alone or in combination of two or more. Among them, sulfenamide vulcanization accelerators are preferable because the effects of the present invention are more suitably obtained, and it is more preferable to use a guanidine vulcanization accelerator together with the sulfenamide vulcanization accelerator. .

Examples of the sulfenamide vulcanization accelerator include N-tert-butyl-2-benzothiazolylsulfenamide (TBBS), N-cyclohexyl-2-benzothiazolylsulfenamide (CBS), N, N -Dicyclohexyl-2-benzothiazolylsulfenamide (DCBS) and the like. These may be used alone or in combination of two or more. Among them, CBS is preferable because the effect of the present invention is more suitably obtained, and it is more preferable to use 1,3-diphenylguanidine together with CBS.

In the rubber composition of the present invention, other than the components described above, compounding agents generally used for producing a rubber composition, such as zinc oxide, stearic acid, a tackifier and the like can be appropriately blended.

As a method for producing the rubber composition of the present invention, a known method can be used. For example, the above-mentioned components are kneaded using a rubber kneading apparatus such as an open roll or a Banbury mixer and then vulcanized. It can be manufactured.

The rubber composition of the present invention can be suitably used for each member of a tire (in particular, a tread and the like which constitute the surface (outer surface) of the tire and have good color fastness, the appearance of the tire, etc.).

The pneumatic tire of the present invention can be produced by a usual method using the rubber composition.
That is, the rubber composition containing the above-mentioned components is extruded according to the shape of the tread or the like in the unvulcanized stage, and is molded together with other tire members by a usual method on a tire molding machine, Unvulcanized tires can be formed. A tire is obtained by heating and pressurizing the unvulcanized tire in a vulcanizer.

The pneumatic tire of the present invention is used as, for example, passenger car tires, truck / bus tires, motorcycle tires, high-performance tires, and the like. In addition, the high-performance tire in this specification is a tire that is particularly excellent in grip performance, and is a concept that includes a competition tire used in a competition vehicle.

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

Hereinafter, various medicines used by an example and a comparative example are summarized and explained.
SBR: Asaprene E15 manufactured by Asahi Kasei Chemicals Corporation
NR: RSS # 3
IR: IR 2200 manufactured by Nippon Zeon Co., Ltd.
BR: BR 730 (cis content: 95% by mass) manufactured by JSR Corporation
Carbon Black: Show Black N330 manufactured by Cabot Japan Co., Ltd. (N ₂ SA: 75 m ² / g, DBP: 102 ml / 100 g)
Silica: Ultrasil VN3 manufactured by Evonik Degussa (N ₂ SA: 175 m ² / g)
Silane coupling agent: Si266 (bis (3-triethoxysilylpropyl) disulfide) manufactured by Evonik Degussa
Wax: Ozo Ace wax oil manufactured by Nippon Seiwa Co., Ltd. Process oil PW-32 manufactured by Idemitsu Kosan Co., Ltd. (paraffin-based process oil)
Surfactant 1: Newpol PE-64 (Pluronic-type nonionic surfactant (PEG / PPG-25 / 30 copolymer) manufactured by Sanyo Kasei Kogyo Co., Ltd. (a + c of the above formula (I): 25, b: 30) )))
Surfactant 2: Newpol PE-74 (Pluronic-type non-ionic surfactant (PEG / PPG-30 / 35 copolymer) manufactured by Sanyo Chemical Industries, Ltd. (a + c: 30 of the above formula (I), b: 35) )))
Surfactant 3: Monosorbic acid polyoxyethylene sorbitan surfactant 4 manufactured by Kanto Chemical Co., Ltd. Surfactant: trioleic acid polyoxyethylene sorbitan surfactant 5 manufactured by Kanto Chemical Co., Ltd. 5: manufactured by Kanto Chemical Co., Ltd. Polyoxyethylene dodecyl ether surfactant 6: Ethylene glycol dibutyl ether antidegradant manufactured by Tokyo Chemical Industry Co., Ltd. Noclack 6C (N- (1,3-dimethylbutyl)-manufactured by Ouchi Emerging Chemical Industry Co., Ltd. N'-phenyl-p-phenylenediamine)
Stearic acid: Sulfur stearate manufactured by NOF Corporation: Powdered sulfur V200 manufactured by Tsurumi Chemical Industry Co., Ltd. Tackirol V200 manufactured by Taoka Chemical Industry Co., Ltd. (alkylphenol-sulfur chloride condensate)
Zinc oxide: Zinc oxide No. 1 vulcanization accelerator manufactured by Mitsui Mining & Smelting Co., Ltd. 1: Noccellar CZ (N-cyclohexyl-2-benzothiazolylsulfenamide) manufactured by Ouchi Emerging Chemical Industry Co., Ltd.
Vulcanization accelerator 2: Noccellar D (1,3-diphenylguanidine) manufactured by Ouchi Shinko Chemical Co., Ltd.

According to the formulation shown in Tables 1 to 3, chemicals other than sulfur, V200 and a vulcanization accelerator were kneaded until reaching 160 ° C. using a 1.7 L Banbury mixer. Next, using an open roll, sulfur, V200 and a vulcanization accelerator were added to the obtained kneaded product and kneaded until it reached 105 ° C. to obtain an unvulcanized rubber composition. Next, the obtained unvulcanized rubber composition was press vulcanized at 160 ° C. for 15 minutes to obtain a vulcanized rubber composition.

The obtained vulcanized rubber composition was evaluated by the following, and the results are shown in Tables 1 to 3. In addition, the reference comparative examples of Tables 1 to 3 were referred to as Comparative Examples 1, 7, and 9, respectively.

<Low fuel consumption>
The tan δ of the vulcanized rubber composition was measured at a dynamic strain amplitude of 1%, a frequency of 10 Hz and a temperature of 50 ° C. using a spectrometer manufactured by Ueshima Seisakusho Co., Ltd. The reciprocal value of tan δ was expressed as an index with the reference comparative example being 100. The larger the index, the lower the rolling resistance and the better the fuel efficiency. The target index was 98 or higher.

<Abrasion resistance>
Using a LAT tester (Laboratory Abbreviation and Skid Tester), the volume loss of each vulcanized rubber composition was measured under the conditions of a load of 50 N, a speed of 20 km / h, and a slip angle of 5 °. The results were indexed using the volume loss of the reference comparative example as 100. The larger the index, the better the wear resistance.

<Preparation of ozone-deteriorated sample>
In accordance with JIS K 6259 “Vulcanized Rubber and Thermoplastic Rubber-Determination of Ozone Resistance”, a test piece of a predetermined size was prepared from the obtained vulcanized rubber composition, and a dynamic ozone deterioration test was performed. And ozone-degraded samples were obtained. The test was performed for 48 hours under conditions of a reciprocating frequency of 0.5 ± 0.025 Hz, an ozone concentration of 50 ± 5 pphm, a test temperature of 40 ° C., and a tensile strain of 20 ± 2%.

<Discoloration resistance evaluation>
The a-value and b-value of the ozone-deteriorated sample were determined using a colorimeter (CR-310) manufactured by Minolta Co., Ltd. (L ^* a ^* b ^* color system). The index was (a ² + b ² ) ^−0.5, and the index of the reference comparative example was 100. An index (index of each composition / index of reference comparative example × 100) was calculated. A larger index indicates less discoloration and better resistance to discoloration.

<Appearance evaluation>
An ozone-degraded sample was taken outdoors and the appearance was evaluated using the following indicators.
黒 Blacker than the standard comparative example and glossy ○ blacker than the standard comparative example slightly brownish 同等 equivalent to the standard comparative example × brown than the standard comparative example

In Examples 1-10, discoloration resistance and the appearance of the tire could be improved while maintaining or improving good fuel economy and wear resistance.

Claims (5)

Containing a rubber component, a nonionic surfactant, sulfur, carbon black and / or silica,
The rubber component comprises at least one selected from the group consisting of styrene butadiene rubber, butadiene rubber, natural rubber, and isoprene rubber,
The total content of carbon black and silica is 20 to 140 parts by mass with respect to 100 parts by mass of the rubber component,
The nonionic surfactant is a nonionic surfactant having a hydrophilic group composed of an ethylene oxide structure on both sides of a hydrophobic group composed of a propylene oxide structure, and represented by the following formula (I): A surfactant,
The rubber composition for tires which contains 0.1-5.0 mass parts of said nonionic surfactants with respect to 100 mass parts of rubber components.

(In formula (I), a, b and c represent integers, b is 20 to 45, and a + c is 3 to 40.) The rubber composition for tires according to claim 1, comprising 5 to 25% by mass of natural rubber in 100% by mass of the rubber component. The rubber composition for a tire according to claim 1, comprising 15 to 55 mass% of butadiene rubber in 100 mass% of the rubber component. The rubber composition for a tire according to any one of claims 1 to 3, wherein the sulfur is contained in an amount of 0.1 to 6.0 parts by mass with respect to 100 parts by mass of the rubber component. The pneumatic tire which has a tire member produced using the rubber composition in any one of Claims 1-4.