JP7372830B2 - Rubber composition for tire sidewalls, tire sidewalls and tires - Google Patents

Description

The present invention relates to a rubber composition for tire sidewalls, a tire sidewall, and a tire.

Tire sidewalls are subject to severe repeated vibrations, so superior toughness, especially improved tear strength, is required. One way to achieve this is to increase the amount of reinforcing agent carbon black. However, it has the disadvantage of worsening the processability of rubber kneading.

Patent Document 1 discloses that by using a rubber composition for tire sidewalls containing diene rubber and hydrogenated liquid polybutadiene as rubber components, excellent tear strength and processability can be achieved without increasing the amount of carbon black blended. It has been shown to have

However, even if the rubber composition of Patent Document 1 is used, it cannot be said that the toughness and processability of the tire sidewall are necessarily improved sufficiently.

Japanese Patent Application Publication No. 2010-70642

An object of the present invention is to provide a rubber composition for tire sidewalls that has excellent toughness, flexibility, and excellent processability during the production of tire sidewalls.

Another object of the present invention is to provide a tire sidewall that exhibits excellent toughness.

Another object of the present invention is to provide a tire that exhibits excellent toughness.

As a result of extensive studies to solve the above-mentioned problems, the inventors of the present invention have discovered that butadiene rubber can be improved by using a rubber component and a pyrazolone compound containing 35 to 65% by mass of the 100% by mass of the rubber component. It has been found that a rubber composition for tire sidewalls that has processability is obtained, and that sidewalls made from the rubber composition for tire sidewalls have excellent toughness and flexibility.

That is, the present invention provides a rubber composition for a tire sidewall, a tire sidewall, a method for producing the rubber composition for a tire sidewall, and a tire shown below.
Item 1.
A rubber composition for tire sidewalls containing the following components (a), (b), and (c).
Component (a) a rubber component containing 35 to 65% by mass of butadiene rubber,
Component (b) at least one compound selected from the group consisting of a compound represented by formula (1), a compound represented by formula (2), and a salt of the compound,
Component (c) carbon black and/or inorganic filler.

（式（１）中、Ｒ^１、Ｒ^２、Ｒ^３及びＲ^４は同一又は異なって、水素原子、アルキル基、アラルキル基、アリール基、又は複素環基を示す。Ｒ^３とＲ^４とは互いに結合してアルキリデン基を形成してもよく、Ｒ^２、Ｒ^３及びＲ^４のいずれか２つが互いに結合してアルキレン基を形成してもよい。これら各基は、それぞれ１個以上の置換基を有していてもよい。）

(In formula (1), R ¹ , R ² , R ³ and R ⁴ are the same or different and represent a hydrogen atom, an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group. What are R ³ and R ⁴ ? They may be combined with each other to form an alkylidene group, or any two of R ² , R ³ and R ⁴ may be combined with each other to form an alkylene group. Each of these groups has one or more substituents. (It may have a group.)

（式（２）中、Ｒ^５、Ｒ^７及びＲ^８は同一又は異なって、水素原子、アミノ基、アルキル基、アラルキル基、アリール基、又は複素環基を示し、Ｒ^６はアルキル基、アラルキル基、アリール基、又は複素環基を示す。これら各基は、それぞれ１個以上の置換基を有していてもよい。）
項２．
前記成分（ｂ）が式（１）により表される化合物である、項１に記載のタイヤサイドウォール用ゴム組成物。
項３．
前記成分（ａ）が天然ゴムを３５～６５質量％を含む、項１又は２に記載のタイヤサイドウォール用ゴム組成物。
項４．
項１～３のいずれかに記載のタイヤサイドウォール用ゴム組成物を用いて作製されたタイヤサイドウォール。
項５．
項４に記載のタイヤサイドウォールを有するタイヤ。
項６．
前記成分（ａ）、（ｂ）及び（ｃ）を含む原料成分を混合する工程（Ａ）を含む、タイヤサイドウォール用ゴム組成物の製造方法。
項７．
前記工程（Ａ）が、前記成分（ａ）及び（ｂ）を混合する工程（Ａ－１）、並びに工程（Ａ－１）で得られた混合物及び前記成分（ｃ）を混合する工程である、項６に記載の製造方法。

(In formula (2), R ⁵ , R ⁷ and R ⁸ are the same or different and represent a hydrogen atom, an amino group, an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group, and R ⁶ is an alkyl group, an aralkyl group. group, aryl group, or heterocyclic group. Each of these groups may have one or more substituents.)
Item 2.
Item 2. The rubber composition for tire sidewalls according to item 1, wherein the component (b) is a compound represented by formula (1).
Item 3.
Item 3. The rubber composition for tire sidewalls according to Item 1 or 2, wherein the component (a) contains 35 to 65% by mass of natural rubber.
Item 4.
Item 3. A tire sidewall produced using the rubber composition for tire sidewall according to any one of Items 1 to 3.
Item 5.
Item 4. A tire having the tire sidewall according to item 4.
Item 6.
A method for producing a rubber composition for tire sidewalls, comprising a step (A) of mixing raw components containing the components (a), (b), and (c).
Section 7.
The step (A) is a step (A-1) of mixing the components (a) and (b), and a step of mixing the mixture obtained in step (A-1) and the component (c). , the manufacturing method according to item 6.

The present invention provides a rubber composition for tire sidewalls that has excellent toughness, flexibility, and excellent processability during the production of tire sidewalls, and a method for producing the rubber composition for tire sidewalls. can do.

INDUSTRIAL APPLICABILITY The present invention can provide a tire sidewall and a tire that exhibit excellent toughness.

The present invention will be explained in detail below.
1. Rubber composition for tire sidewall
The rubber composition for tire sidewalls of the present invention contains the following components (a), (b), and (c).
Component (a) a rubber component containing 35 to 65% by mass of butadiene rubber,
Component (b) at least one compound selected from the group consisting of a compound represented by formula (1), a compound represented by formula (2), and a salt of the compound,
Component (c) carbon black and/or inorganic filler.

（式（１）中、Ｒ^１、Ｒ^２、Ｒ^３及びＲ^４は同一又は異なって、水素原子、アルキル基、アラルキル基、アリール基、又は複素環基を示す。Ｒ^３とＲ^４とは互いに結合してアルキリデン基を形成してもよく、Ｒ^２、Ｒ^３及びＲ^４のいずれか２つが互いに結合してアルキレン基を形成してもよい。これら各基は、それぞれ１個以上の置換基を有していてもよい。）

(In formula (1), R ¹ , R ² , R ³ and R ⁴ are the same or different and represent a hydrogen atom, an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group. What are R ³ and R ⁴ ? They may be combined with each other to form an alkylidene group, or any two of R ² , R ³ and R ⁴ may be combined with each other to form an alkylene group. Each of these groups has one or more substituents. (It may have a group.)

（式（２）中、Ｒ^５、Ｒ^７及びＲ^８は同一又は異なって、水素原子、アミノ基、アルキル基、アラルキル基、アリール基、又は複素環基を示し、Ｒ^６はアルキル基、アラルキル基、アリール基、又は複素環基を示す。これら各基は、それぞれ１個以上の置換基を有していてもよい。）

(In formula (2), R ⁵ , R ⁷ and R ⁸ are the same or different and represent a hydrogen atom, an amino group, an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group, and R ⁶ is an alkyl group, an aralkyl group. group, aryl group, or heterocyclic group. Each of these groups may have one or more substituents.)

1.1. Component (a)
Component (a) is a rubber component containing 35 to 65% by mass of butadiene rubber.

If the content of butadiene rubber in 100% by mass of component (a) is less than 35% by mass, wear resistance will deteriorate. On the other hand, if the content of butadiene rubber in 100% by mass of component (a) exceeds 65% by mass, mechanical properties such as tear strength will deteriorate due to poor dispersion.

As the butadiene rubber, a wide variety of known butadiene rubbers can be used, and there are no particular limitations. For example, hydrogenated butadiene rubber, halogen-modified butadiene rubber, alkoxysilane-modified butadiene rubber, aminoalkoxysilane-modified butadiene rubber, amino-modified butadiene rubber, epoxy-modified butadiene rubber, hydroxyl-modified butadiene rubber, carboxylic acid-modified butadiene rubber, acrylic-modified butadiene rubber. Examples include butadiene rubber, methacrylic group-modified butadiene rubber, isocyanate-modified butadiene rubber, urethane-modified butadiene rubber, carboxyl group-modified butadiene rubber, homopolymer butadiene rubber, and the like. These may be used alone or in combination of two or more.

Further, there is no particular restriction on the cis/trans/vinyl ratio of the double bond in the butadiene rubber, and any ratio can be suitably used. The number average molecular weight and molecular weight distribution of the butadiene rubber are not particularly limited, but preferably a number average molecular weight of 500 to 3,000,000 and a molecular weight distribution of 1.5 to 15.

The rubber components of the rubber composition for tire sidewalls of the present invention are not particularly limited in terms of rubber components other than butadiene rubber, and examples of rubber components other than butadiene rubber include natural rubber (NR), synthetic diene rubber, and rubber components other than butadiene rubber. Examples include mixtures of natural rubber and synthetic diene rubber, as well as non-diene rubbers other than these.

Examples of natural rubber include natural rubber latex, technically graded rubber (TSR), smoked sheet (RSS), gutta-percha, natural rubber derived from mori, natural rubber derived from guayule, and natural rubber derived from Russian dandelion. Modified natural rubbers such as epoxidized natural rubber, methacrylic acid-modified natural rubber, halogen-modified natural rubber, deproteinized natural rubber, maleic acid-modified natural rubber, sulfonic acid-modified natural rubber, and styrene-modified natural rubber can also be used in the present invention. Contains natural rubber.

Synthetic diene rubbers include styrene-butadiene copolymer rubber (SBR), isoprene rubber (IR), nitrile rubber (NBR), chloroprene rubber (CR), and ethylene-propylene-diene terpolymer rubber (EPDM). , styrene-isoprene-styrene triblock copolymer (SIS), styrene-butadiene-styrene triblock copolymer (SBS), and modified synthetic diene rubbers thereof. Modified synthetic diene rubbers include diene rubbers produced by modification methods such as main chain modification, one-terminal modification, and both-terminal modification. Here, the modified functional groups of the modified synthetic diene rubber include various functional groups such as epoxy groups, amino groups, alkoxysilyl groups, and hydroxyl groups, and one or more of these functional groups are present in the modified synthetic diene rubber. May be included in rubber.

The method for producing the synthetic diene rubber is not particularly limited, and examples include emulsion polymerization, solution polymerization, radical polymerization, anionic polymerization, and cationic polymerization. Further, there is no particular restriction on the glass transition point of the synthetic diene rubber.

Furthermore, there is no particular restriction on the cis/trans/vinyl ratio of the double bond in natural rubber and synthetic diene rubber, and any ratio can be suitably used. Further, the number average molecular weight and molecular weight distribution of the diene rubber are not particularly limited, but preferably a number average molecular weight of 500 to 3,000,000 and a molecular weight distribution of 1.5 to 15. As the non-diene rubber, a wide variety of known rubbers can be used.

Regarding rubber components other than these butadiene rubbers, two or more rubber components may be mixed (blended) and used.

The content of component (a) in the total of 100% by mass of components (a), (b), and (c) in the rubber composition for tires is preferably 20 to 99.5% by mass, and 25% by mass. More preferably, it is 99% by mass. When component (a) is contained in an amount of 20% by mass or more, wear resistance is improved. On the other hand, when the component (a) contained in the tire rubber composition is 99.5% by mass or less, the cost of the rubber composition can be reduced, and as a result, the economic efficiency can be improved.

A preferred mixing ratio is 35 to 65 mass % of butadiene rubber and 35 to 65 mass % of rubber components other than butadiene rubber out of 100 mass % of the rubber component, and a more preferred ratio is that of butadiene rubber out of 100 mass % of the rubber component. 37 to 63% by mass of rubber, and 37 to 63% by mass of rubber components other than butadiene rubber, and a particularly preferable range is 40 to 60% by mass of butadiene rubber and rubber components other than butadiene rubber out of 100% by mass of rubber components. It is 40 to 60% by mass.

Among rubber components other than butadiene rubber, preferred rubber components are natural rubber, IR, SBR, or a mixture of two or more selected from these, and more preferably natural rubber, SBR, or two or more selected from these. A mixture of the above, more preferably natural rubber.

When butadiene rubber and natural rubber are mixed, the preferred mixing ratio is 35 to 65% by mass of butadiene rubber and 35 to 65% by mass of natural rubber out of 100% by mass of the rubber component, and the more preferred ratio is Out of 100% by mass, butadiene rubber is 37 to 63% by mass, and natural rubber is 37 to 63% by mass, and a more preferable range is 40 to 60% by mass of butadiene rubber and 40% by mass of natural rubber, out of 100% by mass of the rubber component. ~60% by mass.

1.2. Component (b)
Component (b) is a compound represented by the following formula (1), a compound represented by the following formula (2), and the compound (a compound represented by the formula (1) and a compound represented by the formula (2)). ) is at least one compound selected from the group consisting of salts of In this specification, the compound corresponding to component (b) is also referred to as a "pyrazolone compound."

（式（１）中、Ｒ^１、Ｒ^２、Ｒ^３及びＲ^４は同一又は異なって、水素原子、アルキル基、アラルキル基、アリール基、又は複素環基を示す。Ｒ^３とＲ^４とは互いに結合してアルキリデン基を形成してもよく、Ｒ^２、Ｒ^３及びＲ^４のいずれか２つが互いに結合してアルキレン基を形成してもよい。これら各基は、それぞれ１個以上の置換基を有していてもよい。）

(In formula (1), R ¹ , R ² , R ³ and R ⁴ are the same or different and represent a hydrogen atom, an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group. What are R ³ and R ⁴ ? They may be combined with each other to form an alkylidene group, or any two of R ² , R ³ and R ⁴ may be combined with each other to form an alkylene group. Each of these groups has one or more substituents. (It may have a group.)

（式（２）中、Ｒ^５、Ｒ^７及びＲ^８は同一又は異なって、水素原子、アミノ基、アルキル基、アラルキル基、アリール基、又は複素環基を示し、Ｒ^６はアルキル基、アラルキル基、アリール基、又は複素環基を示す。これら各基は、それぞれ１個以上の置換基を有していてもよい。）

(In formula (2), R ⁵ , R ⁷ and R ⁸ are the same or different and represent a hydrogen atom, an amino group, an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group, and R ⁶ is an alkyl group, an aralkyl group. group, aryl group, or heterocyclic group. Each of these groups may have one or more substituents.)

In this specification, the "alkyl group" is not particularly limited, and includes, for example, linear, branched, or cyclic alkyl groups, and specifically includes, for example, methyl, ethyl, n-propyl, Straight chain or branched alkyl groups having 1 to 4 carbon atoms such as isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, furthermore, 1-ethylpropyl, n-pentyl, isopentyl, neopentyl, n -Hexyl, isohexyl, 3-methylpentyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, 5-propylnonyl, n-tridecyl, n-tetradecyl, n-pentadecyl , hexadecyl, heptadecyl, octadecyl, etc. linear or branched alkyl group having 5 to 18 carbon atoms; cyclic alkyl group having 3 to 8 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, etc. Examples include groups.

In this specification, the "aralkyl group" is not particularly limited and includes, for example, benzyl, phenethyl, trityl, 1-naphthylmethyl, 2-(1-naphthyl)ethyl, 2-(2-naphthyl)ethyl, etc. Can be mentioned.

In the present specification, the "aryl group" is not particularly limited, and includes, for example, phenyl, biphenyl, naphthyl, dihydroindenyl, 9H-fluorenyl group, and the like.

In this specification, the "heterocyclic group" is not particularly limited, and includes, for example, 2-pyridyl, 3-pyridyl, 4-pyridyl, 2-pyrazinyl, 2-pyrimidyl, 4-pyrimidyl, 5-pyrimidyl, 3-pyridyl, Pyridazyl, 4-pyridazyl, 4-(1,2,3-triazyl), 5-(1,2,3-triazyl), 2-(1,3,5-triazyl), 3-(1,2,4 -triazyl), 5-(1,2,4-triazyl), 6-(1,2,4-triazyl), 2-quinolyl, 3-quinolyl, 4-quinolyl, 5-quinolyl, 6-quinolyl, 7- Quinolyl, 8-quinolyl, 1-isoquinolyl, 3-isoquinolyl, 4-isoquinolyl, 5-isoquinolyl, 6-isoquinolyl, 7-isoquinolyl, 8-isoquinolyl, 2-quinoxalyl, 3-quinoxalyl, 5-quinoxalyl, 6-quinoxalyl, 7-quinoxalyl, 8-quinoxalyl, 3-cinnolyl, 4-cinnolyl, 5-cinnolyl, 6-cinnolyl, 7-cinnolyl, 8-cinnolyl, 2-quinazolyl, 4-quinazolyl, 5-quinazolyl, 6-quinazolyl, 7- Quinazolyl, 8-quinazolyl, 1-phthaladyl, 4-phthaladyl, 5-phthaladyl, 6-phthaladyl, 7-phthaladyl, 8-phthaladyl, 1-tetrahydroquinolyl, 2-tetrahydroquinolyl, 3-tetrahydroquinolyl, 4- Tetrahydroquinolyl, 5-tetrahydroquinolyl, 6-tetrahydroquinolyl, 7-tetrahydroquinolyl, 8-tetrahydroquinolyl, 1-pyrrolyl, 2-pyrrolyl, 3-pyrrolyl, 2-furyl, 3-furyl, 2- thienyl, 3-thienyl, 1-imidazolyl, 2-imidazolyl, 4-imidazolyl, 5-imidazolyl, 1-pyrazolyl, 3-pyrazolyl, 4-pyrazolyl, 5-pyrazolyl, 2-oxazolyl, 4-oxazolyl, 5-oxazolyl, 2-thiazolyl, 4-thiazolyl, 5-thiazolyl, 3-isoxazolyl, 4-isoxazolyl, 5-isoxazolyl, 3-isothiazolyl, 4-isothiazolyl, 5-isothiazolyl, 4-(1,2,3-thiadiazolyl), 5- (1,2,3-thiadiazolyl), 3-(1,2,5-thiadiazolyl), 2-(1,3,4-thiadiazolyl), 4-(1,2,3-oxadiazolyl), 5-(1 , 2,3-oxadiazolyl), 3-(1,2,4-oxadiazolyl), 5-(1,2,4-oxadiazolyl), 3-(1,2,5-oxadiazolyl), 2-(1,3 ,4-oxadiazolyl), 1-(1,2,3-triazolyl), 4-(1,2,3-triazolyl), 5-(1,2,3-triazolyl), 1-(1,2,4 -triazolyl), 3-(1,2,4-triazolyl), 5-(1,2,4-triazolyl), 1-tetrazolyl, 5-tetrazolyl, 1-indolyl, 2-indolyl, 3-indolyl, 4- Indolyl, 5-indolyl, 6-indolyl, 7-indolyl, 1-isoindolyl, 2-isoindolyl, 3-isoindolyl, 4-isoindolyl, 5-isoindolyl, 6-isoindolyl, 7-isoindolyl, 1-benzimidazolyl, 2-benzimidazolyl, 4-benzimidazolyl, 5-benzimidazolyl, 6-benzimidazolyl, 7-benzimidazolyl, 2-benzofuranyl, 3-benzofuranyl, 4-benzofuranyl, 5-benzofuranyl, 6-benzofuranyl, 7-benzofuranyl, 1-isobenzofuranyl, 3-iso Benzofuranyl, 4-isobenzofuranyl, 5-isobenzofuranyl, 6-isobenzofuranyl, 7-isobenzofuranyl, 2-benzothienyl, 3-benzothienyl, 4-benzothienyl, 5-benzothienyl, 6 -Benzothienyl, 7-benzothienyl, 2-benzoxazolyl, 4-benzoxazolyl, 5-benzoxazolyl, 6-benzoxazolyl, 7-benzoxazolyl, 2-benzothiazolyl, 4- Benzothiazolyl, 5-benzothiazolyl, 6-benzothiazolyl, 7-benzothiazolyl, 1-indazolyl, 3-indazolyl, 4-indazolyl, 5-indazolyl, 6-indazolyl, 7-indazolyl, 2-morpholyl, 3-morpholyl, 4-morpholyl, 1-piperazyl, 2-piperazyl, 1-piperidyl, 2-piperidyl, 3-piperidyl, 4-piperidyl, 2-tetrahydropyranyl, 3-tetrahydropyranyl, 4-tetrahydropyranyl, 2-tetrahydrothiopyranyl, 3 -Tetrahydrothiopyranyl, 4-tetrahydrothiopyranyl, 1-pyrrolidyl, 2-pyrrolidyl, 3-pyrrolidyl, furanyl, 2-tetrahydrofuranyl, 3-tetrahydrofuranyl, 2-tetrahydrothienyl, 3-tetrahydrothienyl, 5-methyl -3-oxo-2,3-dihydro-1H-pyrazol-4-yl group and the like.

In the present specification, the "alkylene group" is not particularly limited, and includes, for example, an ethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, and the like. These alkylene groups may contain a nitrogen atom, an oxygen atom, a sulfur atom, or may have a phenylene group interposed therebetween. Examples of such _alkylene groups include -CH ₂ NHCH ₂ -, -CH _{2 NHCH 2} CH 2 -, -CH ₂ NHNHCH ₂ -, -CH ₂ CH 2 NHCH ₂ CH ₂ -, -CH ₂ NHNHCH ₂ CH ₂ -, -CH ₂ NHCH ₂ NHCH ₂ -, -CH ₂ CH 2 CH ₂ NHCH ₂ CH ₂ CH ₂ -, -CH ₂ OCH ₂ CH ₂ -, -CH ₂ CH ₂ OCH _{2 CH 2 -} , -CH ₂ SCH ₂ CH ₂ -, -CH ₂ CH ₂ SCH ₂ CH ₂ -,

等が挙げられる。

etc.

In the present specification, the "alkylidene group" is not particularly limited and includes, for example, methylidene, ethylidene, propylidene, isopropylidene, butylidene groups, and the like.

These alkyl groups, aralkyl groups, aryl groups, heterocyclic groups, and alkylene groups may each have one or more substituents at any substitutable position. The "substituent" is not particularly limited, and includes, for example, a halogen atom, an amino group, an aminoalkyl group, an alkoxycarbonyl group, an acyl group, an acyloxy group, an amide group, a carboxyl group, a carboxyalkyl group, a formyl group, and a nitrile group. , nitro group, alkyl group, hydroxyalkyl group, hydroxyl group, alkoxy group, aryl group, aryloxy group, heterocyclic group, thiol group, alkylthio group, arylthio group, and the like. The substituent may preferably have 1 to 5, more preferably 1 to 3 substituents.

In this specification, the "halogen atom" includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and preferably a chlorine atom, a bromine atom, and an iodine atom.

In this specification, the "amino group" includes not only the amino group represented by -NH ₂ but also, for example, methylamino, ethylamino, n-propylamino, isopropylamino, n-butylamino, isobutylamino, s - Straight chain or branched monomers such as butylamino, t-butylamino, 1-ethylpropylamino, n-pentylamino, neopentylamino, n-hexylamino, isohexylamino, 3-methylpentylamino groups, etc. Alkylamino group: Substituted amino groups such as dialkylamino groups having two linear or branched alkyl groups such as dimethylamino, ethylmethylamino, and diethylamino groups are also included.

In this specification, the "aminoalkyl group" is not particularly limited, and includes, for example, aminomethyl, methylaminomethyl, ethylaminomethyl, dimethylaminomethyl, ethylmethylaminomethyl, diethylaminomethyl, 2-aminoethyl, 2- (Methylamino)ethyl, 2-(ethylamino)ethyl, 2-(dimethylamino)ethyl, 2-(ethylmethylamino)ethyl, 2-(diethylamino)ethyl, 3-aminopropyl, 3-(methylamino)propyl , 3-(ethylamino)propyl, 3-(dimethylamino)propyl, 3-(ethylmethylamino)propyl, 3-(diethylamino)propyl, and other aminoalkyl groups, monoalkyl-substituted aminoalkyl groups or dialkyl-substituted aminoalkyl groups Examples include groups.

In this specification, the "alkoxycarbonyl group" is not particularly limited and includes, for example, methoxycarbonyl, ethoxycarbonyl, and the like.

In the present specification, the "acyl group" is not particularly limited, and examples thereof include linear or branched alkylcarbonyl groups having 1 to 4 carbon atoms such as acetyl, propionyl, and pivaloyl groups.

In the present specification, the "acyloxy group" is not particularly limited and includes, for example, acetyloxy, propionyloxy, n-butyryloxy, and the like.

In this specification, the "amide group" is not particularly limited, and includes, for example, carboxylic acid amide groups such as acetamide and benzamide groups; thioamide groups such as thioacetamide and thiobenzamide groups; N-methylacetamide and N-benzylacetamide. N-substituted amide groups such as groups; and the like.

In this specification, the "carboxyalkyl group" is not particularly limited, and includes, for example, carboxymethyl, carboxyethyl, carboxy-n-propyl, carboxy-n-butyl, carboxy-n-pentyl, carboxy-n-hexyl group. Examples include carboxyalkyl groups such as.

In the present specification, the "hydroxyalkyl group" is not particularly limited, and includes, for example, hydroxyalkyl groups such as hydroxymethyl, hydroxyethyl, hydroxy-n-propyl, and hydroxy-n-butyl groups.

In the present specification, the "alkoxy group" is not particularly limited and includes, for example, linear, branched or cyclic alkoxy groups, and specifically includes, for example, methoxy, ethoxy, n-propoxy, Straight chain or branched alkoxy groups such as isopropoxy, n-butoxy, t-butoxy, n-pentyloxy, neopentyloxy, n-hexyloxy groups; cyclopropyloxy, cyclobutyloxy, cyclopentyloxy, cyclohexyloxy , cycloheptyloxy, cyclooctyloxy, and other cyclic alkoxy groups.

In this specification, the "aryloxy group" is not particularly limited and includes, for example, phenoxy, biphenyloxy, naphthoxy groups, and the like.

In the present specification, the "alkylthio group" is not particularly limited and includes, for example, a methylthio group, an ethylthio group, and an n-propylthio group.

In this specification, the "arylthio group" is not particularly limited, and includes, for example, a phenylthio group, a naphthylthio group, a biphenylthio group, and the like.

Component (b) in the rubber composition for tire sidewalls of the present invention may contain only one kind of these compounds, or may contain a mixture of two or more kinds.

In compound (1), R ¹ , R ³ and R ⁴ are the same or different and are a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, an aralkyl group, an aryl group, or a heterocyclic ring. Compounds that are groups are preferred.

Among compounds (1), compounds in which R ¹ is a hydrogen atom are preferred.

Among compounds (1), compounds in which R ² is a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, an aralkyl group, an aryl group, or a heterocyclic group are preferred; More preferably, the compound is a linear or branched alkyl group having 1 to 4 carbon atoms, a benzyl group, a phenyl group, a naphthyl group, or a furyl group, and a hydrogen atom or a linear alkyl group having 1 to 4 carbon atoms. Certain compounds are particularly preferred.

Among compounds (1), compounds in which at least one of R ³ and R ⁴ is a hydrogen atom are preferred, and compounds in which both R ³ and R ⁴ are hydrogen atoms are more preferred.

Among compound (1), R ¹ is a hydrogen atom, R ² is a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, an aralkyl group, an aryl group, or a heterocyclic group, Compounds in which R ³ and R ⁴ are both hydrogen atoms, R ¹ is a hydrogen atom, R ² is a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, an aralkyl group, an aryl group , or a heterocyclic group, and a compound in which R ³ and R ⁴ together form an alkylidene group is more preferred, R ¹ is a hydrogen atom, and R ² is a hydrogen atom or has 1 to 4 carbon atoms. Particularly preferred are compounds in which R ³ and R ⁴ are both hydrogen atoms.

In compound (2), R ⁵ is a hydrogen atom, R ⁶ is a linear or branched alkyl group having 1 to 4 carbon atoms, an aralkyl group, or an aryl group, and R ⁷ and R ⁸ are the same Alternatively, compounds which are hydrogen atoms, linear or branched alkyl groups having 1 to 4 carbon atoms, aralkyl groups, aryl groups, amino groups or heterocyclic groups are preferred.

Among compounds (2), compounds in which R ⁶ is a linear alkyl group having 1 to 4 carbon atoms, an aralkyl group, or an aryl group are preferred; Certain compounds are more preferred.

Among compounds (2), compounds in which R ⁷ and R ⁸ are the same or different and are a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms, or an amino group are preferred.

In compound (2), R ⁵ is a hydrogen atom, R ⁶ is a linear alkyl group having 1 to 4 carbon atoms, or an aryl group, and R ⁷ and R ⁸ are the same or different, and a hydrogen atom, Preferably, the compound is a linear alkyl group having 1 to 4 carbon atoms or an amino group.

Among compound (1) and compound (2), compound (1) is particularly preferred.

Specifically, compound (1) includes, for example, 5-pyrazolone, 3-methyl-5-pyrazolone, 3-(naphthalen-2-yl)-1H-pyrazol-5(4H)-one, 3-(furan) -2-yl)-1H-pyrazol-5(4H)-one, 3-phenyl-1H-pyrazol-5(4H)-one, 3-propyl-1H-pyrazol-5(4H)-one, 3-undecyl -1H-pyrazol-5(4H)-one, 4-(2-hydroxyethyl)-3-methyl-1H-pyrazol-5(4H)-one, 4-benzyl-3-methyl-1H-pyrazol-5( 4H)-one, 4,4'-(phenylmethylene)bis(5-methyl-1H-pyrazol-3(2H)-one), 4-[(dimethylamino)methylidene]-3-methyl-1H-pyrazol-5 (4H)-one, 4-methyl-2,3-diazospiro[4.4]non-3en-1-one, 5-methyl-2-(4-nitrophenyl)-1H-pyrazole-3(2H) -one, 5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one, 4,5,6,7-tetrahydro-2H-indazol-3(3aH)-one, 4-{[ 4-dimethylamino]phenyl}methylidene}-3-methyl-1H-pyrazol-5(4H)-one, 4,4'-(4-hydroxyphenylmethylene)bis(5-methyl-1H-pyrazol-3(2H) )-one), 1,3-diphenyl-1H-pyrazol-5(4H)-one, and 4,4'-(4-nitrophenylmethylene)bis(5-methyl-1H-pyrazol-3(2H) -on), etc.

Specifically, compound (2) includes, for example, 1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one, 1-phenyl-1H-pyrazol-3(2H)-one, 4 -amino-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one and the like.

Among them, a preferred compound is compound (1), among which 5-pyrazolone, 3-methyl-5-pyrazolone, 3-(naphthalen-2-yl)-1H-pyrazol-5(4H)-one, 3 -(furan-2-yl)-1H-pyrazol-5(4H)-one, 3-phenyl-1H-pyrazol-5(4H)-one, and 3-propyl-1H-pyrazol-5(4H)-one is more preferable.

Component (b) in the rubber composition for tire sidewalls of the present invention may contain only one type of the compounds described above as compounds (1) and (2), or may contain a mixture of two or more. good.

Some compounds (1) or (2) generate tautomers. When tautomerization is possible (eg, in solution), a chemical equilibrium of tautomers can be reached. Compound (1) or (2) can exist, for example, as tautomers represented by formulas (3) to (9).

In the above formula (1), the compound (compound (1)-A) in which R ¹ and R ³ are hydrogen atoms has tautomers represented by the following formulas (3) to (5). .

（式中、Ｒ^２及びＲ^４は、前記に同じ。）

(In the formula, R ² and R ⁴ are the same as above.)

In the formula (1), the compound (compound (1)-B) in which R ³ is a hydrogen atom has tautomers represented by the following formulas (6) and (7).

（式中、Ｒ^１、Ｒ^２及びＲ^４は、前記に同じ。）

(In the formula, R ¹ , R ² and R ⁴ are the same as above.)

In the above formula (1), the compound (compound (1)-C) in which R ¹ is a hydrogen atom has a tautomer represented by the following formula (8).

（式中、Ｒ^２、Ｒ^３及びＲ^４は、前記に同じ。）

(In the formula, R ² , R ³ and R ⁴ are the same as above.)

In the above formula (2), the compound (compound (2)-A) in which R ⁵ is a hydrogen atom has a tautomer represented by the following formula (9).

（式中、Ｒ^６、Ｒ^７及びＲ^８は、前記に同じ。）

(In the formula, R ⁶ , R ⁷ and R ⁸ are the same as above.)

The tautomers represented by formulas (3) to (9) above and compound (1) or (2) have reached an equilibrium state in which both isomers coexist. Therefore, unless otherwise stated herein, all tautomeric forms of compound (1) or (2) are within the scope of the present invention.

Furthermore, the salt of the compound represented by formula (1) or (2) is not particularly limited and includes all kinds of salts. Examples of such salts include inorganic acid salts such as hydrochloride, sulfate, and nitrate; organic acid salts such as acetate and methanesulfonate; alkali metal salts such as sodium salt and potassium salt; magnesium salt and calcium salt. Alkaline earth metal salts such as salts; ammonium salts such as dimethylammonium and triethylammonium; and the like.

Component (b) in the rubber composition for tire sidewalls of the present invention may include a mixture containing compound (1) or compound (2) in any proportion.

The amount of component (b) blended is usually preferably 0.01 to 50 parts by mass, and 0.1 to 30 parts by mass, based on 100 parts by mass of component (a) in the rubber composition. The amount is more preferably 0.5 to 10 parts by mass. When the amount of component (b) is 0.01 part by mass or more per 100 parts by mass of component (a), good processability and excellent tear strength can be imparted to the rubber composition. On the other hand, it is preferable that the amount of component (b) is 50 parts by mass or less per 100 parts by mass of component (a), since this reduces the cost of the rubber composition and improves economic efficiency.

The content of component (b) in the total 100 mass% of components (a), (b), and (c) in the rubber composition for tires is preferably 0.001 to 20 mass%, and 0. More preferably, it is .005 to 15% by mass. By containing component (b) in an amount of 0.001% by mass or more, early vulcanization can be suppressed. On the other hand, when the component (b) contained in the rubber composition for tires is 20% by mass or less, the cost of the rubber composition can be reduced, and as a result, the economic efficiency can be improved.

1.3. Component (c)
Component (c) is carbon black and/or inorganic filler.

Carbon black is commonly used to improve the toughness of rubber. Note that in this specification, carbon black is not included in the inorganic filler.

The carbon black is not particularly limited, and examples thereof include commercially available carbon black, Carbon-Silica dual phase filler, and the like. By containing carbon black in the rubber component, it is possible to enjoy the effect of lowering the electrical resistance of the rubber, suppressing charging, and further improving the strength of the rubber.

Examples of carbon black include high, medium or low structure SAF, ISAF, IISAF, N110, N134, N220, N234, N330, N339, N375, N550, HAF, FEF, GPF, SRF grade carbon black, etc. It will be done. Among these, preferred carbon blacks are SAF, ISAF, IISAF, N134, N234, N330, N339, N375, HAF, or FEF grade carbon black.

The average particle size of carbon black is preferably 10 to 300 nm, more preferably 20 to 150 nm, and even more preferably 50 to 70 nm.

The DBP absorption amount of carbon black is not particularly limited, and is preferably 10 to 200 cm ³ /100g, more preferably 20 to 180 cm ³ /100g or more, and even more preferably 25 to 160 cm ³ /100g.

Further, the nitrogen adsorption specific surface area (N2SA, measured according to JISK6217-2:2001) of carbon black is preferably 30 to 200 m ² /g, more preferably 40 to 180 m ² /g, particularly preferably 50 to 200 m 2 /g. It is 160 m ² /g.

The inorganic filler is not particularly limited as long as it is an inorganic compound commonly used in the rubber industry. Inorganic compounds that can be used include, for example, silica; alumina (Al ₂ O ₃ ) such as γ-alumina and α-alumina; alumina monohydrate (Al ₂ O ₃ .H ₂ O) such as boehmite and diaspore; gibbsite. , Bayerite, etc., aluminum hydroxide [Al(OH) ₃ ]; aluminum carbonate [Al ₂ (CO ₃ ) ₃ ], magnesium hydroxide [Mg(OH) ₂ ], magnesium oxide (MgO), magnesium carbonate (MgCO _{3 )} ), talc (3MgO・4SiO ₂・H ₂ O), attapulgium (5MgO・8SiO ₂・9H ₂ O), titanium white (TiO ₂ ), titanium black (TiO _2n-1 ), calcium oxide (CaO), hydroxide Calcium [Ca(OH) ₂ ], magnesium aluminum oxide (MgO・Al ₂ O ₃ ), clay (Al ₂ O ₃・2SiO ₂ ), kaolin (Al ₂ O ₃・2SiO ₂・2H ₂ O), pyrophyllite ( _{Al2O3.4SiO2.H2O ) , bentonite ( Al2O3.4SiO2.2H2O )} , _aluminum silicate _{( Al2SiO5} , _{Al4.3SiO4.5H2O , etc.} ), Magnesium silicate ( _Mg2SiO4 , _MgSiO3 , etc.), calcium silicate ( _Ca2.SiO4 , etc. ₎ , aluminum calcium silicate ( _{Al2O3.CaO.2SiO2 , etc.} ), magnesium calcium silicate (CaMgSiO4 _{, etc.} ) ), calcium carbonate (CaCO ₃ ), zirconium oxide (ZrO ₂ ), zirconium hydroxide [ZrO(OH) ₂ ·nH ₂ O], zirconium carbonate [Zr(CO ₃ ) ₂ ], zinc acrylate, zinc methacrylate, Examples include crystalline aluminosilicates containing hydrogen, alkali metals, or alkaline earth metals that correct charge, such as various zeolites. The surface of these inorganic fillers may be organically treated in order to improve their affinity with the rubber component.

As the inorganic filler, silica is preferred from the viewpoint of imparting rubber strength, and more preferably silica can be used alone or in combination with silica and one or more inorganic compounds commonly used in the rubber industry. When silica and the above-mentioned inorganic compounds other than silica are used together as an inorganic filler, the total amount of all components of the inorganic filler may be adjusted as appropriate so that it falls within the above range. Silica is preferably added because it can impart rubber strength.

Any commercially available silica can be used. Among these, preferable silica is wet silica, dry silica, or colloidal silica, and wet silica is more preferable. The surface of these silicas may be organically treated in order to improve the affinity with the rubber component.

There is no particular limitation on the BET specific surface area of silica, and for example, a range of 40 to 350 m ² /g can be mentioned. Silica having a BET specific surface area within this range has the advantage of being able to achieve both rubber toughness and dispersibility in the rubber component. The BET specific surface area is measured in accordance with ISO5794/1.

From this point of view, preferred silica is silica with a BET specific surface area of 80 to 300 m ² /g, more preferably silica with a BET specific surface area of 100 to 270 m ² /g, particularly preferably: Silica has a BET specific surface area of 110 to 270 m ² /g.

Commercial products of such silica include those available from Quechen Silicon Chemical Co.; , Ltd. Product names "HD165MP" (BET specific surface area = 165 m ² /g), "HD115MP" (BET specific surface area = 115 m ² /g), "HD200MP" (BET specific surface area = 200 m ² /g), "HD250MP" ( BET specific surface area = 250 m ² /g), product name "Nip Seal AQ" manufactured by Tosoh Silica Co., Ltd. (BET specific surface area = 205 m ² /g), "Nip Seal KQ" (BET specific surface area = 240 m ² /g), Degussa For example, "Ultrasil VN3" (BET specific surface area = 175 m ² /g) manufactured by Co., Ltd. under the trade name of "Ultrasil VN3".

The amount of component (c) blended is usually preferably 2 to 200 parts by weight, more preferably 20 to 180 parts by weight, and 30 to 130 parts by weight, based on 100 parts by weight of component (a). It is more preferable that

The content of component (c) in the total of 100% by mass of components (a), (b), and (c) in the rubber composition for tires is preferably 1 to 70% by mass, and 1.5% by mass. More preferably, it is 60% by mass. By containing component (c) in an amount of 1% by mass or more, strength can be imparted to the rubber composition. On the other hand, when the component (c) contained in the rubber composition for tires is 70% by mass or less, low heat build-up can be imparted to the rubber composition.

In the above component (c), when both carbon black and inorganic filler are blended, the total amount of both components may be adjusted as appropriate so that it falls within the above range.

In the above component (c), if the blending amount of carbon black and/or inorganic filler is 2 parts by mass or more, it is preferable from the viewpoint of improving the toughness of the rubber composition, and if it is 200 parts by mass or less, rolling resistance is reduced. preferred from the viewpoint of

In the above component (c), the amount of carbon black blended is usually 2 to 200 parts by mass, preferably 30 to 130 parts by mass, and more preferably 35 to 100 parts by mass, per 100 parts by mass of the rubber component. Department.

In the above component (c), if the blending amount of carbon black is 2 parts by mass or more, it is preferable from the viewpoint of ensuring antistatic performance and rubber strength performance, and if it is 200 parts by mass or less, it is preferable from the viewpoint of reducing rolling resistance. .

In the above component (c), the amount of inorganic filler blended is preferably 2 to 200 parts by weight, more preferably 35 to 130 parts by weight, based on 100 parts by weight of the rubber component.

In the above component (c), the amount of silica blended is usually 2 to 200 parts by mass, preferably 30 to 130 parts by mass, and more preferably 35 to 130 parts by mass, per 100 parts by mass of the rubber component. It is.

In the above component (c), the amount of silica blended is usually 2 to 200 parts by mass, preferably 2 to 200 parts by mass, based on 100 parts by mass of component (a), especially when achieving both maneuverability and fuel efficiency. The amount is 30 to 130 parts by weight, more preferably 35 to 130 parts by weight.

1.4. Other compounding agents In addition to the above-mentioned components (a), (b), and (c), the rubber composition for tire sidewalls of the present invention may contain compounding agents commonly used in the rubber industry, such as anti-aging agents. , anti-ozonants, softeners, processing aids, waxes, resins, blowing agents, oils, fatty acids having 8 to 30 carbon atoms such as stearic acid, zinc oxide (ZnO), vulcanization accelerators, vulcanization retarders, vulcanization A sulfur agent (sulfur) and the like can be appropriately selected and blended within a range that does not impede the purpose of the present invention. Commercially available products can be suitably used as these compounding agents.

In addition, in the rubber composition containing the above component (c), silane is added for the purpose of increasing the toughness of the rubber composition by carbon black and/or silica, or for the purpose of increasing the tear strength and abrasion resistance of the rubber composition. A coupling agent, titanate coupling agent, aluminate coupling agent, or zirconate coupling agent may be blended.

The silane coupling agent that can be used in combination with the component (c) is not particularly limited, and commercially available products can be suitably used. Examples of such silane coupling agents include sulfide-based, polysulfide-based, thioester-based, thiol-based, olefin-based, epoxy-based, amino-based, and alkyl-based silane coupling agents.

Examples of sulfide-based silane coupling agents include bis(3-triethoxysilylpropyl)tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(3-methyldimethoxysilylpropyl)tetrasulfide, and bis(3-trimethoxysilylpropyl)tetrasulfide. 2-triethoxysilylethyl)tetrasulfide, bis(3-triethoxysilylpropyl)disulfide, bis(3-trimethoxysilylpropyl)disulfide, bis(3-methyldimethoxysilylpropyl)disulfide, bis(2-triethoxysilyl) ethyl)disulfide, bis(3-triethoxysilylpropyl)trisulfide, bis(3-trimethoxysilylpropyl)trisulfide, bis(3-methyldimethoxysilylpropyl)trisulfide, bis(2-triethoxysilylethyl)trisulfide Sulfide, bis(3-monoethoxydimethylsilylpropyl)tetrasulfide, bis(3-monoethoxydimethylsilylpropyl)trisulfide, bis(3-monoethoxydimethylsilylpropyl)disulfide, bis(3-monomethoxydimethylsilylpropyl) Tetrasulfide, bis(3-monomethoxydimethylsilylpropyl)trisulfide, bis(3-monomethoxydimethylsilylpropyl)disulfide, bis(2-monoethoxydimethylsilylethyl)tetrasulfide, bis(2-monoethoxydimethylsilylethyl) ) trisulfide, bis(2-monoethoxydimethylsilylethyl) disulfide, and the like. Among these, bis(3-triethoxysilylpropyl)tetrasulfide is particularly preferred.

Examples of thioester-based silane coupling agents include 3-hexanoylthiopropyltriethoxysilane, 3-octanoylthiopropyltriethoxysilane, 3-decanoylthiopropyltriethoxysilane, and 3-lauroylthiopropyltriethoxysilane. , 2-hexanoylthioethyltriethoxysilane, 2-octanoylthioethyltriethoxysilane, 2-decanoylthioethyltriethoxysilane, 2-lauroylthioethyltriethoxysilane, 3-hexanoylthiopropyltrimethoxysilane, 3-octanoylthiopropyltrimethoxysilane, 3-decanoylthiopropyltrimethoxysilane, 3-lauroylthiopropyltrimethoxysilane, 2-hexanoylthioethyltrimethoxysilane, 2-octanoylthioethyltrimethoxysilane, 2 -decanoylthioethyltrimethoxysilane, 2-lauroylthioethyltrimethoxysilane and the like.

Examples of thiol-based silane coupling agents include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-[ethoxybis(3,6,9,12,15 -pentaoxaoctacosan-1-yloxy)silyl]-1-propanethiol and the like.

Examples of olefin-based silane coupling agents include dimethoxymethylvinylsilane, vinyltrimethoxysilane, dimethylethoxyvinylsilane, diethoxymethylvinylsilane, triethoxyvinylsilane, vinyltris(2-methoxyethoxy)silane, allyltrimethoxysilane, and allyltrimethoxysilane. Ethoxysilane, p-styryltrimethoxysilane, 3-(methoxydimethoxydimethylsilyl)propyl acrylate, 3-(trimethoxysilyl)propyl acrylate, 3-[dimethoxy(methyl)silyl]propyl methacrylate, 3-(trimethoxysilyl) Examples include propyl methacrylate, 3-[dimethoxy(methyl)silyl]propyl methacrylate, 3-(triethoxysilyl)propyl methacrylate, and 3-[tris(trimethylsiloxy)silyl]propyl methacrylate.

Examples of epoxy-based silane coupling agents include 3-glycidyloxypropyl(dimethoxy)methylsilane, 3-glycidyloxypropyltrimethoxysilane, diethoxy(3-glycidyloxypropyl)methylsilane, and triethoxy(3-glycidyloxypropyl)silane. , 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and the like. Among these, 3-glycidyloxypropyltrimethoxysilane is preferred.

Examples of amino-based silane coupling agents include N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyl Trimethoxysilane, 3-aminopropyltriethoxysilane, 3-ethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N-(vinylbenzyl)- Examples include 2-aminoethyl-3-aminopropyltrimethoxysilane. Among these, 3-aminopropyltriethoxysilane is preferred.

Examples of alkyl-based silane coupling agents include methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, isobutyltrimethoxysilane, and isobutyltriethoxysilane. Examples include silane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, cyclohexylmethyldimethoxysilane, n-octyltriethoxysilane, and n-decyltrimethoxysilane. Among these, methyltriethoxysilane is preferred.

Among these silane coupling agents, bis(3-triethoxysilylpropyl)tetrasulfide can be particularly preferably used.

The titanate coupling agent that can be used in combination with carbon black and/or inorganic filler is not particularly limited, and commercially available products can be suitably used. Examples of such titanate coupling agents include alkoxide-based, chelate-based, and acylate-based titanate coupling agents.

Examples of alkoxide-based titanate coupling agents include tetraisopropyltinate, tetra-n-butyl titanate, butyl titanate dimer, tetraoctyl titanate, tetratert-butyl titanate, tetrastearyl titanate, and the like. Among these, tetraisopropyl titanate is preferred.

Examples of chelate-based titanate coupling agents include titanium acetylacetonate, titanium tetraacetylacetonate, titanium ethyl acetoacetate, titanium dodecylbenzenesulfonic acid compounds, titanium phosphate compounds, titanium octylene glycolate, and titanium ethyl acetoacetate. , titanium lactate ammonium salt, titanium lactate, titanium ethanolaminate, titanium octylene glycolate, titanium aminoethylaminoethanolate, and the like. Among these, titanium acetylacetonate is preferred.

Examples of the acylate-based titanate coupling agent include titanium isostearate.

The aluminate coupling agent that can be used in combination with carbon black and/or inorganic filler is not particularly limited, and commercially available products can be suitably used. Examples of such aluminate coupling agents include 9-octadecenylacetoacetate aluminum diisopropylate, aluminum secondary butoxide, aluminum trisacetylacetonate, aluminum bisethylacetoacetate monoacetylacetonate, aluminum trisethylacetoacetate, etc. can be mentioned. Among these, 9-octadecenyl acetoacetate aluminum diisopropylate is preferred. The zirconate coupling agent that can be used in combination with carbon black and/or inorganic filler is not particularly limited, and commercially available products can be suitably used. Examples of such zirconate coupling agents include alkoxide-based, chelate-based, and acylate-based zirconate coupling agents.

Examples of the alkoxide-based zirconium coupling agent include normal propyl zirconate and normal butyl zirconate. Among these, normal butyl zirconate is preferred.

Examples of chelate-based zirconate coupling agents include zirconium tetraacetylacetonate, zirconium monoacetylacetonate, zirconium ethyl acetoacetate, and zirconium lactate ammonium salt. Among these, zirconium tetraacetylacetonate is preferred.

Examples of the acylate-based zirconate coupling agent include zirconium stearate and zirconium octylate. Among these, zirconium stearate is preferred.

In the present invention, one type of silane coupling agent, titanate coupling agent, aluminate coupling agent, and zirconate coupling agent may be used alone, or two or more types may be used in combination.

The blending amount of the silane coupling agent in the rubber composition for tire sidewalls of the present invention is preferably 0.1 to 20 parts by weight, particularly preferably 3 to 15 parts by weight, based on 100 parts by weight of the component (c). . When it is 0.1 parts by mass or more, the effect of improving the tear strength of the rubber composition can be more suitably expressed, and when it is 20 parts by mass or less, the cost of the rubber composition is reduced and economical efficiency is improved. do.

2. Method for producing a rubber composition for tire sidewalls In the present invention, a method for producing a rubber composition for tire sidewalls is to mix the above components (a), (b), and (c), and the order of blending is as follows: It is sufficient if it is set appropriately. For example, a method including a step (A) of mixing raw material components containing the above components (a), (b) and (c), a step (A) of mixing raw material components containing the above components (a) and (b) ( A), a method including a step (B) of mixing the mixture obtained in step (A), and component (c), and a step (A) of mixing raw material components containing the above components (a) and (c). ), as well as a method including a step (B) of mixing the mixture obtained in step (A) and component (b), among which a preferable manufacturing method is a method including the step (B) of mixing the mixture obtained in step (A) and component (b). This method includes a step (A) of kneading raw material components including (c) and (c).

2.1. Process (A)
Step (A) is a step of mixing raw material components containing the above components (a), (b), and (c).

In this specification, "mixing" includes not only the mode of simply mixing, but also the mode of so-called "kneading".

In step (A), raw material components containing the above components (a), (b) and (c) are mixed. In this mixing method, the entire amount of each component may be mixed at once, or each component may be added in portions and mixed depending on the purpose such as viscosity adjustment. Alternatively, after mixing the above components (a) and (b), the above component (c) is added, or after mixing the above components (a) and (c), the above component (b) is added. may be mixed. The mixing operation may be repeated in order to uniformly disperse each component. It is also possible to use a filler masterbatch rubber in which a filler is added to the rubber in advance by a wet method and/or a dry mixing method.

In the method of mixing within the rubber component of component (a) above, the entire amount of butadiene rubber and rubber components other than butadiene rubber may be mixed at once, or each component may be added in portions depending on the purpose such as adjusting viscosity. They may be mixed together without any particular restriction.

A masterbatch in which the above components (a) and (b) are mixed in advance in an arbitrary ratio may be used. The blending amount of component (b) in the masterbatch is preferably 0.01 to 200 parts by mass, particularly preferably 0.1 to 100 parts by mass, based on 100 parts by mass of component (a).

Further, as another mixing method in step (A), there is a step (A-1) of mixing the above components (a) and (b), and a mixture obtained in step (A-1) and the above components ( A two-step mixing method including the step (A-2) of mixing the raw material components containing c) with the raw material components can be mentioned.

There is no particular restriction on the temperature when mixing the rubber composition in step (A), and for example, the upper limit of the temperature of the rubber composition is preferably 100 to 190°C, and preferably 110 to 175°C. The temperature is more preferably 120 to 170°C.

The mixing time in step (A) is not particularly limited, and for example, it is preferably from 10 seconds to 20 minutes, more preferably from 30 seconds to 10 minutes, and even more preferably from 1 minute to 8 minutes. preferable.

The temperature at which components (a) and (b) are mixed in step (A-1) is preferably 60 to 190°C, more preferably 70 to 180°C, and 80 to 170°C. More preferably, the temperature is .degree. By setting the mixing temperature to 60° C. or higher, the reaction proceeds effectively. Moreover, by setting the mixing temperature to 190° C. or lower, deterioration of the rubber can be prevented. In the case of the liquid mixing method, the temperature of the rubber component is preferably 60 to 190°C, more preferably 70 to 180°C, and even more preferably 80 to 170°C.

The mixing time in step (A-1) is preferably 10 seconds to 20 minutes, more preferably 30 seconds to 10 minutes, and even more preferably 60 seconds to 7 minutes. By setting the mixing time to 10 seconds or more, it is possible to allow the reaction to proceed sufficiently. On the other hand, by setting the mixing time to 20 minutes or less, productivity is improved. In the case of a liquid mixing method, the mixing time is preferably from 10 seconds to 60 minutes, more preferably from 30 seconds to 40 minutes, and even more preferably from 60 seconds to 30 minutes. After the mixing reaction by the liquid mixing method, the solid rubber composition can be recovered by removing the solvent in the mixture, for example, under reduced pressure.

There is no particular restriction on the temperature at which the mixture obtained in step (A-1) and the above component (c) are mixed in step (A-2). For example, the temperature of the mixture is 100 to 190°C. The temperature is preferably 110 to 175°C, even more preferably 130 to 170°C.

The mixing time in step (A-2) is not particularly limited; for example, it is preferably from 10 seconds to 20 minutes, more preferably from 30 seconds to 10 minutes, and from 1 minute to 8 minutes. is even more preferable.

2.2. Process (B)
In step (B), other compounding agents such as stearic acid, zinc oxide, anti-aging agents, and vulcanizing agents may be added to the mixture obtained in step (A), if necessary.

Step (B) can be performed under heating conditions. The heating temperature in this step is not particularly limited, and is preferably, for example, 60 to 140°C, more preferably 80 to 120°C, and even more preferably 90 to 120°C.

There is no particular restriction on the mixing time, and for example, it is preferably from 10 seconds to 20 minutes, more preferably from 30 seconds to 10 minutes, and even more preferably from 60 seconds to 5 minutes.

When proceeding from step (A) to step (B), it is preferable to proceed to the next step (B) after lowering the temperature by 30° C. or more from the temperature after the completion of the previous step.

In step (A), mixing is performed using a Banbury mixer, a roll, an intensive mixer, a kneader, a single screw extruder, a twin screw extruder, or the like. Thereafter, it is extruded and processed in an extrusion process to form a tire sidewall member. Subsequently, the green tire is molded by pasting and molding using a conventional method on a tire molding machine. This raw tire is heated and pressurized in a vulcanizer to obtain a tire.

In the method for producing a rubber composition for tire sidewalls of the present invention, other compounding agents such as stearic acid, zinc oxide, anti-aging agents, and vulcanizing agents, which are usually blended into the rubber composition, may be added to the rubber composition in the process as necessary. It can be added not only in (B) but also in step (A).

Other compounding agents may be added in either step (A) or step (B), or may be added separately in step (A) and step (B). In addition, among other compounding agents, it is preferable to add a vulcanizing agent or a vulcanization accelerator in step (B).

2.3. Method for Molding Rubber Composition for Tire Sidewalls The rubber composition for tire sidewalls in the present invention is mixed using a Banbury mixer, a roll, an intensive mixer, a kneader, a single-screw extruder, a twin-screw extruder, or the like. Thereafter, it is extruded and processed in an extrusion process to form a tire sidewall.

3. Tire Sidewall The tire sidewall of the present invention is a tire sidewall produced using the rubber composition for tire sidewalls of the present invention.

The sidewall section is, for example, the section from the lower side of the shoulder section to the bead section of a pneumatic radial tire, which protects the carcass and is the section that bends the most during running.

The tire sidewall of the present invention has excellent toughness.

4. Tire The tire of the present invention includes the tire sidewall of the present invention. It can be manufactured according to methods hitherto known in the field of tires.

Examples of the tire of the present invention include pneumatic tires (radial tires, bias tires, etc.), solid tires, and the like.

The use of the tire is not particularly limited and includes, for example, tires for passenger cars, tires for heavy loads, tires for motorcycles (two-wheeled motor vehicles), studless tires, etc. Among them, it can be suitably used for tires for passenger cars.

The shape, structure, size, and material of the tire of the present invention are not particularly limited and can be appropriately selected depending on the purpose.

In the tire of the present invention, a green tire is molded by attaching and molding a member molded as a tire sidewall on a tire molding machine using a conventional method. It is obtained by heating and pressurizing this green tire in a vulcanizer.

The tire of the present invention has excellent toughness.

Although the embodiments of the present invention have been described above, the present invention is not limited to these examples at all, and it goes without saying that the present invention can be implemented in various forms without departing from the gist of the present invention.

Hereinafter, embodiments of the present invention will be described in more detail based on Examples, but the present invention is not limited thereto.

Production Example 1: Production of 3-(naphthalen-2-yl)-1H-pyrazol-5(4H)-one (compound (b)-2) 8.5 g ( 52.1 mmol) of carbonyldiimidazole was added to a 100 mL eggplant flask. and 60 mL of dehydrated tetrahydrofuran were added, and the mixture was stirred at room temperature. Then, 7.5 g (43.6 mmol) of 2-naphthoic acid was added to this mixture, and the mixture was stirred at room temperature overnight. Hereinafter, this obtained reaction solution will be referred to as "reaction solution 1."
14.8 g (87.0 mmol) of potassium monoethylmalonate, 210 mL of dehydrated acetonitrile, and 18.3 mL (132.4 mmol) of triethylamine were added to a 500 mL four-necked flask, and the mixture was stirred under ice cooling. Then, 10.4 g (109.2 mmol) of magnesium chloride was added to this mixture, and the mixture was stirred at room temperature for 4 hours. The above reaction solution 1 was added dropwise to the obtained reaction solution, and the mixture was stirred overnight at room temperature.
The reaction solution was concentrated, and 125 mL of toluene was added to the resulting residue, which was washed with 70 mL of 4M hydrochloric acid and 70 mL of water. The organic layer was dried over anhydrous magnesium sulfate, and then concentrated under reduced pressure. This was purified by silica gel column chromatography (n-hexane:ethyl acetate = 4:1 (volume ratio)) to obtain a colorless and transparent liquid.
2.2 mL (44.8 mmol) of hydrazine monohydrate was added to this liquid, 2.0 mL (35.0 mmol) of acetic acid was added dropwise, and the mixture was refluxed for 4 hours. The reaction solution was returned to room temperature, 30 mL of diisopropyl ether was added, and the precipitated crystals were filtered to obtain 8.22 g of 3-(naphthalen-2-yl)-1H-pyrazol-5(4H)-one as a white solid. Ta.
Melting point: 204℃
^1H -NMR (300MHz, _d6 -DMSO, δppm):
11.94 (1H, br), 8.20-8.21 (1H, J=1.2Hz, d), 7.82-7.96 (4H, m), 7.47-7.56 (2H , m), 6.02 (1H, s) ¹³ C-NMR (500 MHz, d ₆ -DMSO, δppm):
168.13, 160.95, 143.83, 133.06, 132.39, 128.30, 127.90, 127.62, 126.55, 126.06, 123.28, 123.14, 87. 10

Production Example 2: Production of 3-(furan-2-yl)-1H-pyrazol-5(4H)-one (compound (b)-3) 8.7 g (53.5 mmol) of carbonyldiimidazole was added to a 100 mL eggplant flask. and 60 mL of dehydrated tetrahydrofuran were added, and the mixture was stirred at room temperature. Next, 5.0 g (45.0 mmol) of 2-furancarboxylic acid was added to this mixture, and the mixture was stirred at room temperature overnight. Hereinafter, this obtained reaction solution will be referred to as "reaction solution 2."
14.8 g (87.0 mmol) of potassium monoethylmalonate, 200 mL of dehydrated acetonitrile, and 18.3 mL (132.4 mmol) of triethylamine were added to a 500 mL four-necked flask, and the mixture was stirred under ice cooling. Then, 10.4 g (109.2 mmol) of magnesium chloride was added to this mixture, and the mixture was stirred at room temperature for 4 hours. The above reaction solution 2 was added dropwise to this reaction solution, and the mixture was stirred at room temperature overnight.
The resulting reaction solution was concentrated, 120 mL of chloroform was added, and washed with 70 mL of 4M hydrochloric acid and 70 mL of water. The organic layer was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to obtain a colorless and transparent liquid.
2.5 mL (50.7 mmol) of hydrazine monohydrate was added to the obtained liquid, 2.0 mL (35.0 mmol) of acetic acid was added dropwise, and the mixture was refluxed for 4 hours. The resulting reaction solution was returned to room temperature, 30 mL of diisopropyl ether was added, and the precipitated crystals were filtered to form a white solid of 3-(furan-2-yl)-1H-pyrazol-5(4H)-one 5. 47g was obtained. Melting point: 231℃
^1H -NMR (300MHz, _d6 -DMSO, δppm):
11.79 (2H, br), 7.68-7.69 (1H, m), 6.69 (1H, J = 3.3Hz, d), 6.55 (1H, J = 1.8, 1 .5, 1.8Hz, dd), 5.69 (1H, s)
^13C -NMR (500MHz, _d6 -DMSO, δppm):
160.23, 146.16, 142.24, 135.84, 111.50, 105.77, 85.88

Production Example 3: Production of 3-phenyl-1H-pyrazol-5(4H)-one (compound (b)-4) Add 25 g (0.13 mol) of ethyl benzoylacetate and 25 mL of ethanol to a 100 mL four-necked flask and stir. did. While cooling this in a water bath, 6.5 mL (0.13 mol) of hydrazine monohydrate was added dropwise. After stirring at room temperature for 4 hours, the precipitated solid was filtered, washed with 50 mL of a mixed solution of water: methanol = 1:1 (volume ratio), and dried to obtain 3-phenyl-1H-pyrazole-5 as a white solid. 18.8 g of (4H)-one was obtained.
Melting point: 236℃
^1H -NMR (500MHz, _d6 -DMSO, δppm):
12.03 (1H, br), 9.69 (1H, br), 7.66 (2H, m), 7.39 (2H, m), 7.30 (1H, m), 5.88 (1H ,s)
^13C -NMR (500MHz, _d6 -DMSO, δppm):
161.00, 143.48, 130.48, 128.73, 127.71, 124.73, 86.87

Production Example 4: Production of 3-propyl-1H-pyrazol-5(4H)-one (compound (b)-5) In a 500 mL four-necked flask, 24.8 g (0.16 mol) of methyl 3-oxohexanoate, and 260 mL of ethanol was added and stirred. While cooling this in an ice bath, 8.6 mL (0.18 mol) of hydrazine monohydrate was added dropwise, and after stirring for 2 hours under ice cooling, the mixture was heated under reflux for 2 hours, and the reaction solution was cooled to room temperature. The precipitated solid was filtered, washed with 50 mL of a mixed solution of water:methanol = 1:1 (volume ratio), and dried to obtain 3-propyl-1H-pyrazol-5(4H)-one 13. as a white solid. 2g was obtained.
Melting point: 205-206℃
^1H -NMR (500MHz, _d6 -DMSO, δppm):
11.11 (1H, br), 9.42 (1H, br), 5.23 (1H, s), 2.41 (2H, J=7.5Hz, t), 1.54 (2H, m) , 0.88 (3H, J=7.3Hz, t)
^13C -NMR (500MHz, _d6 -DMSO, δppm):
160.87, 144.04, 87.93, 27.67, 21.93, 13.57

Production Example 5: Production of 4,4'-(phenylmethylene)bis(5-methyl-1H-pyrazol-3(2H)-one) (compound (b)-6) In a 2L four-necked flask, add 1L of water, 10 g (0.10 mol) of 3-methyl-5-pyrazolone, 5.4 g (0.05 mol) of benzaldehyde, and 0.73 g (2.5 mmol) of sodium dodecyl sulfate were added, stirred at room temperature for 30 minutes, and then refluxed for 1 hour. did. After stirring the reaction solution for 30 minutes while cooling it in an ice bath, the precipitated solid was filtered, washed with 500 mL of water, and dried to form a pale yellow solid of 4,4'-(phenylmethylene)bis(5). -Methyl-1H-pyrazol-3(2H)-one) was obtained.
Melting point: 230-232℃
^1H -NMR (500MHz, _d6 -DMSO, δppm):
11.31 (4H, br), 7.20 (2H, m), 7.12 (3H, m), 4.81 (1H, s), 2.07 (6H, s)
^13C -NMR (500MHz, _d6 -DMSO, δppm):
161.24, 143.33, 139.73, 127.67, 127.47, 125.35, 104.21, 32.72, 10.34

Production Example 6: Production of 4,4'-(4-hydroxyphenylmethylene)bis(5-methyl-1H-pyrazol-3(2H)-one) (compound (b)-7) In a 3L four-necked flask, Add 2.5 L of water, 25.0 g (0.26 mol) of 3-methyl-5-pyrazolone, 15.6 g (0.13 mol) of 4-hydroxybenzaldehyde, and 1.84 g (6.4 mmol) of sodium dodecyl sulfate to room temperature. After stirring for 30 minutes, the mixture was refluxed for 1 hour. After stirring the reaction solution for 30 minutes while cooling it in an ice bath, the precipitated solid was filtered, washed with 2.5 L of water, and dried to form a pale yellow solid of 4,4'-(4-hydroxyphenyl). 33.5 g of methylene)bis(5-methyl-1H-pyrazol-3(2H)-one) was obtained.
Melting point: 262-264℃
^1H -NMR (500MHz, _d6 -DMSO, δppm):
11.22 (4H, br), 9.03 (1H, s), 6.91 (2H, J=8.5Hz, d), 6.59 (2H, J=8.5Hz, d), 4. 71 (1H, s), 2.06 (6H, s)
^13C -NMR (500MHz, _d6 -DMSO, δppm):
161.12, 155.03, 139.67, 133.44, 128.27, 114.42, 104.84, 31.91, 10.35

Production Example 7: Production of 4,4'-(4-nitrophenylmethylene)bis(5-methyl-1H-pyrazol-3(2H)-one) (compound (b)-8) In a 3L four-necked flask, Add 2.5 L of water, 25.0 g (0.26 mol) of 3-methyl-5-pyrazolone, 19.3 g (0.13 mol) of 4-nitrobenzaldehyde, and 1.84 g (6.4 mmol) of sodium dodecyl sulfate to room temperature. After stirring for 30 minutes, the mixture was refluxed for 1 hour. After stirring the reaction solution for 30 minutes while cooling it in an ice bath, the precipitated solid was filtered, washed with 500 mL of methanol, and dried to produce 4,4'-(4-nitrophenylmethylene) as a pale yellow solid. 37.8 g of bis(5-methyl-1H-pyrazol-3(2H)-one) was obtained.
Melting point: 300-302℃
^1H -NMR (500MHz, _d6 -DMSO, δppm):
11.40 (4H, br), 8.12 (2H, J=8.8Hz, d), 7.38 (2H, J=8.8Hz, d), 4.98 (1H, s), 2. 10 (6H, s)
^13C -NMR (500MHz, _d6 -DMSO, δppm):
160.82, 151.71, 145.56, 139.71, 128.76, 122.94, 103.24, 32.95, 10.28

Production Example 8: Production of 4-[(dimethylamino)methylidene]-3-methyl-1H-pyrazol-5(4H)-one (compound (b)-9) Into a 500 mL four-necked flask, add 300 mL of xylene, 3- 14.7 g (0.15 mol) of methyl-5-pyrazolone and 21.6 g (0.18 mol) of N,N-dimethylformamide dimethyl acetal were added and stirred at 110° C. overnight. After cooling the reaction solution to room temperature, the precipitated solid was filtered, washed with 300 mL of toluene, and dried to obtain a yellow solid of 4-[(dimethylamino)methylidene]-3-methyl-1H-pyrazole-5 (4H )-one 20.3g was obtained.
Melting point: 158-159℃
^1H -NMR (500MHz, _d6 -DMSO, δppm):
10.30 (1H, br), 7.27 (1H, s), 3.75 (3H, s), 3.26 (3H, s), 1.97 (3H, s)
^13C -NMR (500MHz, _d6 -DMSO, δppm):
164.77, 152.66, 149.66, 97.13, 46.74, 42.44, 13.35

Production Example 9: Production of 4-{[4-dimethylamino]phenyl}methylidene}-3-methyl-1H-pyrazol-5(4H)-one (compound (b)-10) In a 3L four-necked flask, add ethanol. 2.7 L, 27.0 g (0.28 mol) of 3-methyl-5-pyrazolone, 44.4 g (0.30 mol) of 4-dimethylaminobenzaldehyde, and 4.7 g (55 mmol) of piperidine were added, and the mixture was refluxed for 3 hours. . After stirring this reaction solution overnight at room temperature, the precipitated solid was filtered and dried to give a pale yellow solid of 4-{[4-dimethylamino]phenyl}methylidene}-3-methyl-1H-pyrazole-5. 46.3 g of (4H)-one was obtained.
Melting point: 164℃
^1H -NMR (500MHz, _d7 -DMF, δppm):
10.91 (1H, br), 8.70 (2H, J=9.3Hz, d), 7.45 (1H, s), 6.83 (2H, J=9.3Hz, d), 3. 15 (6H, s), 2.18 (3H, s)
^13C -NMR (500MHz, _d7 -DMF, δppm):
166.74, 153.84, 150.55, 146.23, 136.92, 122.49, 120.74, 111.43, 39.58, 12.98

Production Example 10: Production of 3-undecyl-1H-pyrazol-5(4H)-one (compound (b)-11) Add 2.8 g (17.4 mmol) of carbonyldiimidazole and 20 mL of chloroform to a 50 mL eggplant flask. , stirred at room temperature. Then, 2.9 g (14.5 mmol) of lauric acid was added to this mixture, and the mixture was stirred at room temperature overnight. Hereinafter, this obtained reaction solution will be referred to as "reaction solution 3."
4.9 g (30.0 mmol) of potassium monoethylmalonate, 70 mL of dehydrated acetonitrile, and 6.1 mL (44.1 mmol) of triethylamine were added to a 200 mL four-necked flask, and the mixture was stirred under ice cooling. Then, 3.5 g (36.4 mmol) of magnesium chloride was added to the obtained mixture, and the mixture was stirred at room temperature for 4 hours. The above reaction solution 3 was added dropwise to this reaction solution, and the mixture was stirred at room temperature overnight. The resulting reaction solution was concentrated, 42 mL of chloroform was added, and washed with 48 mL of 2M hydrochloric acid and 48 mL of water. The organic layer was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to obtain an intermediate.
To the obtained intermediate were added 20 mL of ethanol and 0.7 mL (14.9 mmol) of hydrazine monohydrate, 0.7 mL (11.7 mmol) of acetic acid was added dropwise, and the mixture was refluxed for 4 hours. The reaction solution was returned to room temperature, 10 mL of diisopropyl ether was added, and the precipitated crystals were filtered to obtain 2.83 g of 3-undecyl-1H-pyrazol-5(4H)-one as a white solid.
Melting point: 188℃
^1H -NMR (300MHz, _d6 -DMSO, δppm):
11.05 (1H, br), 9.45 (1H, br), 5.21 (1H, s), 2.39 to 2.44 (2H, J = 7.5Hz, t), 1.48 to 1.53 (2H, m), 1.30 (16H, s), 0.83 to 0.88 (3H, m)
^13C -NMR (500MHz, _d6 -DMSO, δppm):
160.85, 144.20, 87.84, 31.27, 29.01, 28.98, 28.95, 28.71, 28.68, 28.62, 28.57, 25.60, 22. 06,13.90

Production Example 11: Production of 4-(2-hydroxyethyl)-3-methyl-1H-pyrazol-5(4H)-one (compound (b)-12) In a 100 mL four-necked flask, α-acetyl-γ- 24.3 g (0.19 mol) of butyrolactone and 24 mL of ethanol were added and stirred. While cooling this in an ice bath, 9.7 mL (0.20 mol) of hydrazine monohydrate was added dropwise, and the mixture was stirred at room temperature for 3 hours. The precipitated solid was filtered, washed with 50 mL of isopropanol, and dried to obtain 23.8 g of 4-(2-hydroxyethyl)-3-methyl-1H-pyrazol-5(4H)-one as a white solid. .
Melting point: 182℃
^1H -NMR (500MHz, _d7 -DMF, δppm):
10.62 (2H, br), 3.78 (2H, J=7.0Hz, t), 3.66 (1H, br), 2.69 (2H, J=7.0Hz, t), 2. 31 (3H, s)
^13C -NMR (500MHz, _d7 -DMF, δppm):
160.88, 137.87, 98.61, 62.29, 26.18, 9.66

Production Example 12: Production of 4-benzyl-3-methyl-1H-pyrazol-5(4H)one (compound (b)-13) In a 100 mL four-necked flask, 24.5 g (0.0 g) of ethyl 2-benzylacetoacetate was added. 11 mol) and 25 mL of ethanol were added and stirred. While cooling the mixture in an ice bath, 5.7 mL (0.12 mol) of hydrazine monohydrate was added dropwise thereto, followed by stirring at room temperature for 3 hours. The precipitated solid was filtered, washed with 50 mL of a mixed solution of water:methanol = 1:1 (volume ratio), and dried to obtain 4-benzyl-3-methyl-1H-pyrazole-5 (4H) as a white solid. 15.6 g of on was obtained.
Melting point: 228-229℃
^1H -NMR (500MHz, _d6 -DMSO, δppm):
11.08 (1H, br), 9.46 (1H, br), 7.24 (2H, m), 7.14 (3H, m), 3.55 (2H, s), 2.01 (3H ,s)
^13C -NMR (500MHz, _d6 -DMSO, δppm):
159.58, 141.90, 136.82, 128.06, 127.96, 125.37, 99.94, 27.28, 9.94

Production Example 13: Production of 1-phenyl-1H-pyrazol-3(2H)-one (compound (b)-14) In a 1 L four-necked flask, 10 g (62 mmol) of 1-phenyl-3-pyrazolidone and N, 150 mL of N-dimethylformamide was added and stirred. To this was added 317 mg (3.2 mmol) of copper(I) chloride, and the mixture was stirred overnight in an open system. After adding 750 mL of water to the reaction solution and stirring for 30 minutes while cooling in an ice bath, the precipitated solid was filtered, washed with 750 mL of water, and dried to obtain 1-phenyl-1H-pyrazole-3 as a light brown solid. 6.1 g of (2H)-one was obtained.
Melting point: 152℃
^1H -NMR (500MHz, _d6 -DMSO, δppm):
10.22 (1H, br), 8.22 (1H, s), 7.68 (2H, m), 7.42 (2H, m), 7.18 (1H, m), 5.80 (1H ,s)
^13C -NMR (500MHz, _d6 -DMSO, δppm):
162.64, 139.79, 129.29, 128.37, 124.59, 116.76, 94.47

Production Example 14: Production of 4-methyl-2,3-diazospiro[4.4]non-3en-1-one (compound (b)-15) 7.2 g of methyl acetoacetate (62 0 mmol), 23.1 g (75 mmol) of 1,4-diiodobutane, 42.9 g (310 mmol) of potassium carbonate, and 220 mL of dimethyl sulfoxide were added, and the mixture was stirred at room temperature overnight. After adding 220 mL of water to the reaction solution and stirring for 10 minutes, the organic layer obtained by extraction with 300 mL of isopropyl ether was washed twice with 200 mL of water. The organic layer was dried over sodium sulfate, concentrated, and subjected to column purification (hexane:ethyl acetate = 50:1 (volume ratio)) to obtain 6.5 g (36 mmol) of an intermediate.
The obtained intermediate and 6 mL of ethanol were mixed, and while cooling on an ice bath, 1.8 mL (39 mmol) of hydrazine monohydrate was added, and the mixture was stirred at 60° C. overnight. The solid obtained by concentrating the reaction solution was washed with 40 mL of a mixture of hexane:ethyl acetate = 5:1 (volume ratio) to obtain 4-methyl-2,3-diazospiro[4.4] as a white solid. 3.8 g of non-3en-1-one was obtained.
Melting point: 83-84℃
^1H -NMR (500MHz, _d6 -DMSO, δppm):
10.77 (1H, s), 1.92 (3H, s), 1.86-1.66 (8H, m)
^13C -NMR (500MHz, _d6 -DMSO, δppm):
181.64, 163.37, 55.78, 33.53, 26.48, 13.34

Production Example 15: Production of 4,5,6,7-tetrahydro-2H-indazol-3(3aH)-one (compound (b)-16) Ethyl 2-oxocyclohexanecarboxylate was placed in a 100 mL four-necked flask.24. 5 g (0.14 mol) and 24 mL of ethanol were added and mixed. 7.3 mL (0.15 mol) of hydrazine monohydrate was added dropwise to this while cooling in an ice bath, and the mixture was stirred at 80° C. for 3 hours, and then stirred for 30 minutes while cooling in an ice bath. Thereafter, the precipitated solid was filtered, washed with 50 mL of a mixed solution of water: methanol = 1:1 (volume ratio), and dried to form a white solid of 4,5,6,7-tetrahydro-2H-indazole-3. 17.3 g of (3aH)-one was obtained.
Melting point: 286-288℃
^1H -NMR (500MHz, _d6 -DMSO, δppm):
10.50 (1H, br), 9.66 (1H, br), 2.43 (2H, J=5.7Hz, t), 2.22 (2H, J=5.7Hz, t), 1. 67-1.62 (4H, m)
^13C -NMR (500MHz, _d6 -DMSO, δppm):
158.30, 139.62, 98.41, 22.86, 22.27, 21.26, 18.88

Production Example 16: Production of 1,3-diphenyl-1H-pyrazol-5(4H)-one (compound (b)-17) In a 1 L four-necked flask, 50.0 g (0.26 mol) of ethyl benzoylacetate and phenyl 28.1 g (0.26 mol) of hydrazine, 4.5 mL (0.08 mol) of acetic acid, and 500 mL of water were added and mixed. This was stirred at 100°C for 1 hour, then stirred for 30 minutes while cooling in an ice bath, and the precipitated solid was filtered, washed with 1 L of a mixed solution of water:methanol = 1:1 (volume ratio), and dried. As a result, 58.0 g of 1,3-diphenyl-1H-pyrazol-5(4H)-one as a pale orange solid was obtained.
Melting point: 137-138℃
^1H -NMR (500MHz, _d6 -DMSO, δppm):
11.81 (1H, br), 7.83 (4H, m), 7.49 (2H, m), 7.42 (2H, m), 7.35-7.28 (2H, m), 6 .02 (1H, s)
^13C -NMR (500MHz, _d6 -DMSO, δppm):
153.73, 149.52, 138.85, 133.41, 128.87, 128.51, 127.78, 125.65, 125.04, 121.11, 85.05

Examples 1 to 4 and Comparative Examples 1 to 4: Production of rubber compositions Each component listed in step (A) of Table 1 below was mixed in the proportions (parts by mass) and mixed using a Banbury mixer. After curing until the temperature of the mixture becomes 60°C or less, add each component listed in step (B) of Table 1 in the proportion (parts by mass) and adjust so that the maximum temperature of the mixture becomes 70°C or less. A rubber composition was prepared by mixing the mixture while stirring.

尚、表１における各成分の詳細は、下記の通りである。
※１：成分（ａ）：ＮＲ（天然ゴム）；ＧＵＡＮＧＫＥＮ ＲＵＢＢＥＲ社製、ＴＳＲ－２０
※２：成分（ａ）：ＢＲ（ブタジエンゴム）；Sinopec Qilu Petrochemical Co., Ltd.製、商品名「ＢＲ９０００」
※３：成分（ｃ）：カーボンブラック；Ｃａｂｏｔ社製、Ｎ５５０
※４：老化防止剤（Ｎ－フェニル－Ｎ'－（１,３－ジメチルブチル）－ｐ－フェニレンジアミン）；Ｋｅｍａｉ Ｃｈｅｍｉｃａｌ Ｃｏ．，Ｌｔｄ社製
※５：ワックス；Ｒｈｅｉｎ Ｃｈｅｍｉｅ Ｒｈｅｉｎａｕ社製、Ａｎｔｉｌｕｘ １１１
※６：酸化亜鉛；Ｄａｌｉａｎ Ｚｉｎｃ Ｏｘｉｄｅ Ｃｏ．，Ｌｔｄ社製
※７：ステアリン酸；Ｓｉｃｈｕａｎ Ｔｉａｎｙｕ Ｇｒｅａｓｅ社製
※８：オイル；Hansen & Rosenthal社製、商品名「Ｖｉｖａｔｅｃ ７００」
※９：成分（ｂ）：化合物（ｂ－１）；大塚化学株式会社製、３－メチル－５－ピラゾロン
※１０：加硫促進剤（ Ｎ－シクロヘキシル－２－ベンゾチアゾリルスルフェンアミド）；Kemai Chemical Co., Ltd.製、商品名「ＣＢＳ」
※１１：硫黄 ；Ｓｈａｎｇｈａｉ Ｊｉｎｇｈａｉ Ｃｈｅｍｉｃａｌ Ｃｏ．，Ｌｔｄ社製

The details of each component in Table 1 are as follows.
*1: Component (a): NR (natural rubber); manufactured by GUANGKEN RUBBER, TSR-20
*2: Component (a): BR (butadiene rubber); manufactured by Sinopec Qilu Petrochemical Co., Ltd., product name "BR9000"
*3: Component (c): Carbon black; manufactured by Cabot, N550
*4: Anti-aging agent (N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine); Kemai Chemical Co. , Ltd *5: Wax; Rhein Chemie Rheinau, Antilux 111
*6: Zinc oxide; Dalian Zinc Oxide Co. , Ltd *7: Stearic acid; manufactured by Sichuan Tianyu Grease *8: Oil; manufactured by Hansen & Rosenthal, product name "Vivatec 700"
*9: Component (b): Compound (b-1); manufactured by Otsuka Chemical Co., Ltd., 3-methyl-5-pyrazolone *10: Vulcanization accelerator (N-cyclohexyl-2-benzothiazolylsulfenamide); Manufactured by Kemai Chemical Co., Ltd., product name "CBS"
*11: Sulfur; Shanghai Jinghai Chemical Co. , Ltd.

Examples 1 to 4 and Comparative Examples 1 to 4: Toughness (tear strength) test Each tear strength index of the rubber compositions obtained in Examples 1 to 4 and Comparative Examples 1 to 4 below was determined by crescent type test according to JIS K6252. Measurement was performed using a piece at room temperature and at a tensile speed of 500 mm/min. The value of Comparative Example 1 obtained here was expressed as an index as 100, and the tear strength was calculated based on the following formula. Note that the higher the numerical value of the tear strength, the higher the tear strength and the better the toughness.
Formula: Tear strength index = (Tear strength of the rubber compositions of Examples 1 to 4 and Comparative Examples 2 to 4)/(Tear hardness of Comparative Example 1) x 100

Examples 1 to 4 and Comparative Examples 1 to 4: Processability (Scorch Time) Test Each scorch time index of the unvulcanized rubber compositions obtained in Examples 1 to 4 and Comparative Examples 1 to 4 below was determined according to JIS Scorch time was measured according to K 6300. The value of Comparative Example 1 obtained here was expressed as an index as 100, and the scorch time index was calculated based on the following formula. Note that the larger the value of the scorch time index, the longer the scorch time and the better the processability.
Formula: Scorch time index = (Scorch time of the rubber compositions of Examples 1 to 4 and Comparative Examples 2 to 4)/(Scorch time of Comparative Example 1) x 100

In the examples of the present invention, both the tear strength index and the scorch time index showed larger values compared to Comparative Example 1, and it was confirmed that excellent toughness and workability were exhibited in a well-balanced manner.

The rubber composition for tire sidewalls of the present invention has excellent processability during the production of tire sidewalls, and can impart excellent toughness to the rubber component. Therefore, it can be used as sidewalls of various pneumatic tires for various automobiles.

Claims (7)

Contains the following components (a), (b), and (c),
The blending amount of the component (b) is 0.5 to 10 parts by mass per 100 parts by mass of the component (a),
A rubber composition for tire sidewalls, wherein the amount of component (c) is 30 to 130 parts by mass based on 100 parts by mass of component (a):
Component (a) a rubber component containing 35 to 65% by mass of butadiene rubber,
Component (b) at least one compound selected from the group consisting of a compound represented by formula (1), a compound represented by formula (2), and a salt of the compound,
Component (c) carbon black and/or inorganic filler.

(In formula (1), R ¹ , R ² , R ³ and R ⁴ are the same or different and represent a hydrogen atom, an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group. What are R ³ and R ⁴ ? They may be combined with each other to form an alkylidene group, or any two of R ² , R ³ and R ⁴ may be combined with each other to form an alkylene group. Each of these groups has one or more substituents. (It may have a group.)

(In formula (2), R ⁵ , R ⁷ and R ⁸ are the same or different and represent a hydrogen atom, an amino group, an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group, and R ⁶ is an alkyl group, an aralkyl group. group, aryl group, or heterocyclic group. Each of these groups may have one or more substituents.) The rubber composition for tire sidewalls according to claim 1, wherein the component (b) is a compound represented by formula (1). The rubber composition for tire sidewalls according to claim 1 or 2, wherein the component (a) contains 35 to 65% by mass of natural rubber. A tire sidewall produced using the rubber composition for tire sidewall according to any one of claims 1 to 3. A tire comprising the tire sidewall according to claim 4. A method for producing a rubber composition for tire sidewalls, comprising a step (A) of mixing raw material components containing the following components (a), (b) and (c),
The blending amount of the following component (b) is 0.5 to 10 parts by mass per 100 parts by mass of the following component (a),
The amount of the following component (c) is 30 to 130 parts by mass per 100 parts by mass of the following component (a), a manufacturing method :
Component (a) a rubber component containing 35 to 65% by mass of butadiene rubber,
Component (b) at least one compound selected from the group consisting of a compound represented by formula (1), a compound represented by formula (2), and a salt of the compound,
Component (c) carbon black and/or inorganic filler.

(In formula (1), R ¹ , R ² , R ³ and R ⁴ are the same or different and represent a hydrogen atom, an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group. What are R ³ and R ⁴ ? They may be combined with each other to form an alkylidene group, or any two of R ² , R ³ and R ⁴ may be combined with each other to form an alkylene group. Each of these groups has one or more substituents. (It may have a group.)

(In formula (2), R ⁵ , R ⁷ and R ⁸ are the same or different and represent a hydrogen atom, an amino group, an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group, and R ⁶ is an alkyl group, an aralkyl group. group, aryl group, or heterocyclic group. Each of these groups may have one or more substituents.) The step (A) includes a step (A-1) of mixing the components (a) and (b), and a step (A-1) of mixing the mixture obtained in step (A-1) and the component (c). -2) The manufacturing method according to claim 6.