JP7257973B2 - Rubber composition and tire - Google Patents

Description

The present invention relates to rubber compositions and tires.

In recent years, there has been a strong demand for low fuel consumption of automobiles, and tires with low rolling resistance are required. Therefore, a rubber composition having a low tan δ and excellent low heat build-up is desired as a rubber composition for use in tire treads and the like.

In order to achieve low heat build-up in conventional pneumatic tires, measures such as increasing the particle size of carbon black in the rubber composition or reducing the amount of carbon black compounded can be considered. At the same time, there is a problem that the abrasion resistance of the tread rubber is lowered, and the fracture resistance such as cut resistance and chipping resistance of the rubber is lowered.

Therefore, it has been desired to develop a technique capable of improving low heat build-up without deteriorating other physical properties such as wear resistance.
As one of those techniques, for example, Patent Document 1 discloses that carbon black and a specific hydrazide compound are blended into an elastomer containing natural rubber for the purpose of improving the chemical interaction between the rubber component and carbon black. A rubber composition is disclosed.

Japanese translation of PCT publication No. 2014-501827

However, the technology disclosed in Patent Document 1 is not sufficient in low heat build-up, and further improvement in low heat build-up is required to meet the demand for low fuel consumption of automobiles. In addition, when the technique of Patent Document 1 is used to improve the low heat build-up, polymer gel is generated in the rubber composition, and it is considered that the processability may deteriorate (increase in viscosity). Further improvement was also desired in terms of sexuality.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a rubber composition having low heat build-up, excellent wear resistance and workability. Another object of the present invention is to provide a tire having low heat build-up, excellent wear resistance and productivity.

The present inventors have made intensive studies on rubber compositions containing a rubber component and a filler in order to solve the above problems. Then, the present inventors have focused on the fact that by including a hydrazide compound having a specific structure in the rubber composition, the interaction between the rubber component and carbon black can be enhanced, and as a result, more excellent low heat build-up can be achieved. Then, regarding the problem of deterioration of processability due to the formation of the polymer gel described above, by further containing an anti-aging agent containing a compound having a phenol group in the rubber composition, excellent low heat build-up and The inventors have found that both wear resistance and excellent workability can be achieved, and have completed the present invention.

（式中、Ａは、アリール基であり、少なくとも２つの極性基を有し、該極性基は同じであっても、異なっていてもよい。Ｒ¹及びＲ²は、それぞれ独立して、水素原子、アシル基、アミド基、アルキル基、シクロアルキル基及びアリール基からなる群から選択される少なくとも一種の置換基であり、さらに、該置換基は、Ｏ、Ｓ及びＮ原子のうちの一種以上を含んでいてもよい。）
上記構成を具えることによって、優れた低発熱性、耐摩耗性及び加工性を実現できる。That is, the rubber composition of the present invention comprises a rubber component containing a diene rubber, a filler, a compound represented by the following formula (I), and an antioxidant containing a compound having a phenol group. characterized by comprising

(In the formula, A is an aryl group, has at least two polar groups, and the polar groups may be the same or different. R ¹ and R ² are each independently hydrogen at least one substituent selected from the group consisting of an atom, an acyl group, an amide group, an alkyl group, a cycloalkyl group and an aryl group, and the substituent is one or more of O, S and N atoms may contain.)
By providing the above configuration, excellent low heat build-up, wear resistance and workability can be achieved.

Further, in the rubber composition of the present invention, at least one of the polar groups of A in the compound represented by the formula (I) is preferably a hydroxyl group, an amino group or a nitro group, and the polar group is more preferably a hydroxyl group, and particularly preferably at least two of the polar groups are hydroxyl groups. This is because better low heat build-up and wear resistance can be achieved.

Furthermore, in the rubber composition of the present invention, A in the compound represented by formula (I) is preferably a phenyl group or a naphthyl group. This is because more excellent low heat build-up and wear resistance can be achieved, and it is also excellent in terms of practicality.

Moreover, in the rubber composition of the present invention, both R ¹ and R ² in the compound represented by formula (I) are preferably hydrogen atoms. This is because better low heat build-up and wear resistance can be achieved.

Further, in the rubber composition of the present invention, it is preferable that the compound represented by the formula (I) has a molecular weight of 250 or less. This is because better low heat build-up and wear resistance can be achieved.

Furthermore, in the rubber composition of the present invention, the melting point of the compound represented by formula (I) is preferably 80°C or higher and lower than 250°C. This is because better low heat build-up and wear resistance can be achieved.

Further, in the rubber composition of the present invention, the content of the compound represented by formula (I) is preferably 0.05 to 30 parts by mass with respect to 100 parts by mass of the rubber component. This is because more excellent low heat build-up and wear resistance can be achieved, and deterioration of workability can be effectively suppressed.

Furthermore, in the rubber composition of the present invention, the compound represented by the formula (I) is 2,6-dihydroxybenzohydrazide, 2,3-dihydroxybenzohydrazide, 2,4-dihydroxybenzohydrazide, 2,5 -dihydroxybenzohydrazide, 4-amino-2-hydroxybenzohydrazide, 3,5-dihydroxynaphthalene-2-carbohydrazide, 4-amino-3-hydroxynaphthalene-2-carbohydrazide, 3-hydroxy-4-nitronaphthalene- at least one selected from the group consisting of 2-carbohydrazide, 1,3-dihydroxynaphthalene-2-carbohydrazide, 2,4,6-trihydroxybenzohydrazide and 2,6-dihydroxy-4-methylbenzohydrazide Preferably. This is because better low heat build-up and wear resistance can be achieved.

Further, in the rubber composition of the present invention, the diene rubber is preferably natural rubber. This is because excellent wear resistance can be achieved.

Furthermore, in the rubber composition of the present invention, the filler preferably contains carbon black. This is because excellent wear resistance can be achieved.

Furthermore, in the rubber composition of the present invention, the content of the filler is preferably 10 to 160 parts by mass with respect to 100 parts by mass of the rubber component. This is because better low heat build-up and wear resistance can be achieved.

Further, in the rubber composition of the present invention, the compound having a phenol group preferably has a ratio of molecular weight to the number of phenol groups of 250 or less. This is because better workability can be realized.

Furthermore, in the rubber composition of the present invention, the total content of the anti-aging agent is preferably 0.05 to 10 parts by mass with respect to 100 parts by mass of the rubber component. This is because better processability can be achieved without causing deterioration in viscosity.

Furthermore, in the rubber composition of the present invention, it is preferable that the proportion of the compound having a phenol group in the anti-aging agent is 20 to 100% by mass. This is because more excellent workability can be realized while obtaining an anti-aging effect.

Further, in the rubber composition of the present invention, the anti-aging agent further contains an amine-based anti-aging agent, and the proportion of the amine-based anti-aging agent in the anti-aging agent is 80% by mass or less. preferable. This is because deterioration of workability can be suppressed more reliably.

A tire of the present invention is characterized by using the rubber composition described above.
By providing the above configuration, excellent low heat build-up, wear resistance and productivity can be achieved.

ADVANTAGE OF THE INVENTION According to this invention, the rubber composition excellent in low heat build-up property, abrasion resistance, and workability can be provided. Moreover, according to the present invention, it is possible to provide a tire having low heat build-up, excellent wear resistance, and excellent productivity.

（式中、Ａは、アリール基であり、少なくとも２つの極性基を有し、該極性基は同じであっても、異なっていてもよい。Ｒ¹及びＲ²は、それぞれ独立して、水素原子、アシル基、アミド基、アルキル基、シクロアルキル基及びアリール基からなる群から選択される少なくとも一種の置換基であり、さらに、該置換基は、Ｏ、Ｓ及びＮ原子のうちの一種以上を含んでいてもよい。）Embodiments of the present invention will be specifically described below by way of illustration.
<Rubber composition>
The rubber composition of the present invention is a rubber composition containing a rubber component, a filler, a compound represented by the following formula (I), and an antioxidant containing a compound having a phenol group.

(In the formula, A is an aryl group, has at least two polar groups, and the polar groups may be the same or different. R ¹ and R ² are each independently hydrogen at least one substituent selected from the group consisting of an atom, an acyl group, an amide group, an alkyl group, a cycloalkyl group and an aryl group, and the substituent is one or more of O, S and N atoms may contain.)

(rubber component)
The rubber component contained in the rubber composition of the present invention is not particularly limited as long as it contains a diene rubber.
Examples of the diene rubber include natural rubber, polybutadiene rubber (BR), polyisoprene rubber (IR), styrene-butadiene copolymer rubber (SBR), styrene-isoprene-butadiene rubber (SIBR), and chloroprene rubber (CR). , acrylonitrile-butadiene rubber (NBR) and other synthetic diene rubbers, and among these, at least natural rubber is preferably included. This is because more excellent low heat build-up can be achieved, and an improvement in wear resistance can also be expected.
Incidentally, the diene rubber may be contained singly or as a blend of two or more.

As for the rubber component, in addition to the above-mentioned diene-based rubbers, non-diene-based rubbers such as ethylene propylene diene rubber (EPDM), ethylene propylene rubber (EPM), butyl rubber (IIR) and the like are used within a range that does not impair the effects of the invention. It is also possible to include synthetic rubber.

The content of the diene rubber in the rubber component is not particularly limited, but from the viewpoint of maintaining excellent low heat build-up and abrasion resistance, it is preferably 80% by mass or more, and 90% by mass. % or more is more preferable.

(filler)
The rubber composition of the present invention contains a filler in addition to the rubber component described above.
By including the filler together with the rubber component and the compound represented by the formula (I) described later, the dispersibility of the filler is enhanced, and performance such as strength and wear resistance is maintained at a high level, and excellent Low heat build-up can be achieved.

Here, the content of the filler is not particularly limited, but it is preferably 10 to 160 parts by mass, more preferably 30 to 100 parts by mass, with respect to 100 parts by mass of the rubber component. preferable. This is because by optimizing the amount of the filler, it is possible to achieve better low heat build-up and wear resistance. When the content is 160 parts by mass or less, deterioration of low heat build-up can be suppressed.

Also, the type of the filler is not particularly limited. For example, carbon black, silica, and other inorganic fillers can be included. Among these, the filler preferably contains carbon black. This is because more excellent low heat build-up can be achieved, and an improvement in wear resistance can also be expected.
Examples of the carbon black include carbon blacks of GPF, FEF, SRF, HAF, ISAF, IISAF, and SAF grades.

The content of the carbon black is preferably 10 parts by mass or more, more preferably 30 parts by mass or more, with respect to 100 parts by mass of the rubber component, from the viewpoint of obtaining more excellent abrasion resistance. Preferably, it is more preferably 50 parts by mass or more. This is because the abrasion resistance of the rubber composition can be further improved by setting the content of the carbon black to 10 parts by mass or more with respect to 100 parts by mass of the rubber component. In addition, the content of the carbon black is preferably 160 parts by mass or less, more preferably 90 parts by mass or less, and further preferably 70 parts by mass or less with respect to 100 parts by mass of the rubber component. preferable. By setting the content of the carbon black to 160 parts by mass or less with respect to 100 parts by mass of the rubber component, it is possible to further improve low heat build-up and workability while maintaining a high level of wear resistance. .

The silica used as the filler is not particularly limited, and for example, wet silica, dry silica, colloidal silica, and the like can be used.
As the other inorganic filler, it is also possible to use, for example, an inorganic compound represented by the following formula (II).
_{nM.xSiOY.zH2O (} II)
(In the formula, M is a metal selected from the group consisting of Al, Mg, Ti, Ca and Zr, oxides or hydroxides of these metals, hydrates thereof, and carbonates of these metals n, x, y and z are each an integer of 1 to 5, an integer of 0 to 10, an integer of 2 to 5, and an integer of 0 to 10.)

Examples of the inorganic compound of formula (II) include alumina ( _{Al2O3 )} such as γ-alumina and _α -alumina; alumina monohydrate ( _Al2O3 · _H2O ) such as boehmite and diaspore; , bayerite and other aluminum hydroxide [Al(OH) ₃ ]; aluminum carbonate [ _Al2 ( _CO3 ) ₃ ], magnesium hydroxide [Mg(OH) ₂ ], magnesium oxide (MgO), magnesium carbonate ( _MgCO3 ), talc ( _{3MgO.4SiO2.H2O} ), _attapulgite ( _{5MgO.8SiO2.9H2O} ), titanium white ( _TiO2 ), titanium black ( _{TiO2n-1 )} , calcium oxide (CaO), hydroxide _Calcium [Ca(OH _{) 2 ]} , _magnesium aluminum oxide _{( MgO.Al2O3} ), clay ( _Al2O3.2SiO2 ), kaolin ( _{Al2O3.2SiO2.2H2O} ), _pyrophyllite ( _{Al2O3.4SiO2.H2O ) , bentonite ( Al2O3.4SiO2.2H2O )} , _aluminum silicate _{( Al2SiO5} , _{Al4.3SiO4.5H2O , etc.} ), Magnesium silicate ( _Mg2SiO4 , _MgSiO3 , etc.), calcium _silicate ( _{Ca2SiO4 , etc.} ), aluminum calcium silicate ( _{Al2O3.CaO.2SiO2 , etc.} ), magnesium calcium silicate ( _CaMgSiO4 ) , calcium carbonate ( _CaCO3 ), zirconium oxide ( _ZrO2 ), zirconium hydroxide [ZrO(OH) _2.nH2O ], zirconium carbonate [Zr( _CO3 ) ₂ ], various _zeolites to compensate for charge Crystalline aluminosilicates containing hydrogen, alkali metals or alkaline earth metals and the like can be mentioned.

式（Ｉ）の、Ａは、アリール基である。ここで、該アリール基は、任意の位置に少なくとも２つの極性基を有し、該極性基は同じであっても、異なっていてもよく、前記極性基の位置については、アリール基の芳香環中のどこであってもよい。
また、式（Ｉ）のＲ¹及びＲ²は、それぞれ独立して、水素原子、アシル基、アミド基、アルキル基、シクロアルキル基及びアリール基からなる群から選択される少なくとも一種の置換基である。さらに、これらの置換基については、Ｏ、Ｓ及びＮ原子のうちの一種以上を含んでいてもよい。(Compound represented by formula (I))
The rubber composition of the present invention contains the compound represented by Formula (I) in addition to the rubber component and filler described above.

In formula (I), A is an aryl group. Here, the aryl group has at least two polar groups at arbitrary positions, and the polar groups may be the same or different. can be anywhere in the
R ¹ and R ² in formula (I) are each independently at least one substituent selected from the group consisting of a hydrogen atom, an acyl group, an amido group, an alkyl group, a cycloalkyl group and an aryl group; be. Furthermore, these substituents may contain one or more of O, S and N atoms.

In the compound represented by the above formula (I), the aryl group represented by A has a high affinity with fillers such as carbon black, and the portion having a hydrazide skeleton has a high affinity with the rubber component. Therefore, by blending in the rubber composition, chemical interaction between the rubber component and the filler can be greatly improved. As a result, it is possible to reduce hysteresis loss caused by friction between fillers, and as a result, it is possible to obtain extremely excellent low heat build-up as compared with the conventional art. In addition, better wear resistance can be achieved by improving the dispersibility of the filler.
In addition, as a result of the greatly improved chemical interaction between the rubber component and the filler, it is possible to suppress the increase in the viscosity of the unvulcanized rubber while maintaining the low heat build-up and abrasion resistance of the rubber composition. can also be improved.

Here, examples of the aryl group represented by A in the compound represented by formula (I) include aromatic hydrocarbon groups such as phenyl, naphthyl, anthryl, phenanthryl and triphenylenyl groups. Among these, the aryl group is preferably a phenyl group or a naphthyl group, more preferably a phenyl group. Since it exhibits excellent affinity with fillers, it is possible to achieve better low heat build-up and abrasion resistance, and since the number of aromatic rings can be reduced, it is advantageous in terms of cost and practicality.

In addition, the number of polar groups possessed by the aryl group represented by A in the compound represented by formula (I) is two or more. By having two or more polar groups in the aromatic ring, it is possible to obtain a high affinity with a filler such as carbon black. However, the low heat build-up and abrasion resistance of the rubber composition may be lowered.
Further, the type of the polar group is not particularly limited. , carbonyl group, epoxy group, oxycarbonyl group, nitrogen-containing heterocyclic group, oxygen-containing heterocyclic group, tin-containing group, alkoxysilyl group, alkylamino group, nitro group and the like. Among them, at least one of the polar groups is preferably a hydroxyl group, an amino group or a nitro group, more preferably a hydroxyl group, and particularly preferably at least two are hydroxyl groups. This is because it exhibits an even better affinity with the filler, and can further improve the low heat build-up and abrasion resistance of the rubber composition.

In addition, with respect to the hydrazide group connected to A in the compound represented by the formula (I), R ¹ and R ² are each independently a hydrogen atom, an acyl group, an amide group, an alkyl group, a cycloalkyl group and an aryl is at least one substituent selected from the group consisting of groups; These substituents may contain one or more of O, S and N atoms.
Furthermore, R ¹ and R ² are preferably a hydrogen atom or an alkyl group among the substituents described above, and more preferably both R ¹ and R ² are hydrogen atoms. This is because it has a high affinity with the rubber component and provides excellent low heat build-up, wear resistance and workability.

２，３－ジヒドロキシベンゾヒドラジド

２，４－ジヒドロキシベンゾヒドラジド

２，５－ジヒドロキシベンゾヒドラジド

４－アミノ－２－ヒドロキシベンゾヒドラジド

３，５－ジヒドロキシナフタレン－２－カルボヒドラジド

４－アミノ－３－ヒドロキシナフタレン－２－カルボヒドラジド

３－ヒドロキシ－４－ニトロナフタレン－２－カルボヒドラジド

１，３－ジヒドロキシナフタレン－２－カルボヒドラジド

２，４，６－トリヒドロキシベンゾヒドラジド

２，６－ジヒドロキシ－４－メチルベンゾヒドラジド

Here, some suitable examples of the compound represented by the above formula (I) are shown below. By using these compounds, the low heat build-up of the rubber composition can be further improved. In addition, these compounds can be used individually by 1 type, and can also be used in mixture of multiple types.
2,6-dihydroxybenzohydrazide

2,3-dihydroxybenzohydrazide

2,4-dihydroxybenzohydrazide

2,5-dihydroxybenzohydrazide

4-amino-2-hydroxybenzohydrazide

3,5-dihydroxynaphthalene-2-carbohydrazide

4-amino-3-hydroxynaphthalene-2-carbohydrazide

3-hydroxy-4-nitronaphthalene-2-carbohydrazide

1,3-dihydroxynaphthalene-2-carbohydrazide

2,4,6-trihydroxybenzohydrazide

2,6-dihydroxy-4-methylbenzohydrazide

The molecular weight of the compound represented by formula (I) is preferably 250 or less, more preferably 200 or less, and even more preferably 180 or less. This is because the affinity with each molecule of natural rubber is increased, so that excellent low heat build-up can be obtained, and wear resistance can also be improved.

The melting point of the compound represented by formula (I) is preferably 80°C or higher and lower than 250°C, more preferably 80 to 200°C. This is because, by lowering the melting point of the hydrazide compound, the affinity with each molecule of natural rubber is increased, and excellent low heat build-up can be obtained, and abrasion resistance can also be improved.

The content of the compound represented by the formula (I) in the rubber composition of the present invention is preferably 0.05 to 30 parts by mass, preferably 0.05 parts by mass, with respect to 100 parts by mass of the rubber component. It is more preferably 10 parts by mass, and particularly preferably 0.05 to 5 parts by mass. By setting the content to 0.05 parts by mass or more with respect to 100 parts by mass of the rubber component, more excellent low heat build-up and abrasion resistance can be obtained, and by setting it to 30 parts by mass or less, processability is improved. This is because deterioration can also be prevented.

(Antiaging agent)
The rubber composition of the present invention further contains an antioxidant in addition to the rubber component, filler and compound represented by formula (I) described above. The anti-aging agent is required to contain a compound having a phenol group (hereinafter sometimes referred to as a "phenol group-containing compound").
By including the compound represented by the formula (I), it has become possible to greatly improve the chemical interaction between the rubber component and the filler. thought it would get worse. Therefore, in the present invention, by using a phenol group-containing compound as an anti-aging agent in the rubber composition, it is possible to improve the processability while maintaining the low heat build-up at an excellent level.

Here, the type of the phenol group-containing compound is not particularly limited, and can be appropriately selected from known antioxidants and used.
Examples of the phenol group-containing compounds include monophenol-based compounds, bisphenol-based compounds, thiobisphenol-based compounds, hindered phenol-based compounds, and polyphenol-based compounds.

Further, with respect to the phenol group-containing compound, among the compounds described above, the ratio of the molecular weight to the number of phenol groups (molecular weight/number of phenol groups) is preferably 250 or less, more preferably 200 or less. . This is because better workability can be obtained. Regarding the number of phenol groups in the phenol group-containing compound, a compound in which two phenol groups are bonded to one benzene ring (such as hydroquinone) is assumed to have two phenol groups.
In addition, 2,2′-methylenebis(4-methyl-6-tert -butylphenol), 4,4′-butylidenebis(3-methyl-6-tert-butylphenol), 2,6-di-tert-butyl-4-methylphenol, 2,5-di-tert-amylhydroquinone, 2, 5-di-tert-butylhydroquinone, 1,1-bis(4-hydroxyphenyl)cyclohexane, 4,4'-thiobis(3-methyl-6-tert-butylphenol), 2,6 di-tert-butyl-4 -ethylphenol and bis(3,5-di-tert-butyl-4-hydroxybenzyl)sulfide.

Furthermore, the proportion of the phenol group-containing compound in the antioxidant is preferably 20 to 100% by mass, more preferably 20 to 80% by mass. By setting the ratio of the phenol group-containing compound to 20% by mass or more, deterioration of the processability of the rubber composition can be suppressed. Moreover, although it can consist only of the said phenol-group containing compound, by making it 80 mass % or less, an anti-aging effect can be obtained more reliably.

The anti-aging agent may contain an anti-aging agent other than the phenol group-containing compound for the purpose of improving the anti-aging action, etc., as long as the effects of the present invention are not impaired. For example, it may further contain an amine anti-aging agent. In that case, the content of the amine antioxidant in the antiaging agent is preferably 80% by mass or less, more preferably 60% by mass or less. This is because deterioration of the processability of the rubber composition can be suppressed by setting the content of the amine-based antioxidant in the anti-aging agent to 80% by mass or less.

Further, the total content of the anti-aging agent in the rubber composition of the present invention is preferably 0.05 to 10 parts by mass, preferably 0.05 to 5 parts by mass, with respect to 100 parts by mass of the rubber component. is more preferable. By setting the total content of the anti-aging agent to 0.05 parts by mass or more with respect to 100 parts by mass of the rubber component, the anti-aging effect can be obtained more reliably, and the content of the anti-aging agent is By making it 10 parts by mass or less with respect to 100 parts by mass of the rubber component, deterioration of workability can be suppressed.

(other ingredients)
The rubber composition of the present invention is commonly used in the rubber industry in addition to the rubber component, the filler, the antioxidant containing the compound represented by the formula (I), and the compound having a phenol group. Compounding agents such as softening agents, silane coupling agents, zinc oxide, vulcanization accelerators, vulcanizing agents, etc. can be appropriately selected and included within the range not impairing the object of the present invention. Commercially available products can be suitably used as these compounding agents.

In addition, the manufacturing method of the rubber composition of the present invention is not particularly limited. For example, it can be obtained by blending and kneading a rubber component containing a diene rubber, a filler, a compound represented by formula (I), and an antioxidant by a known method.

<Tire>
The tire of the present invention is characterized by using the rubber composition of the present invention described above. By including the rubber composition of the present invention, which has excellent low heat build-up and workability, as a tire material, excellent low heat build-up and productivity can be achieved.
Regarding the part to which the rubber composition is applied, it is preferable to use it for the tread among tires. A tire using the rubber composition of the present invention in the tread is excellent in low heat build-up.
The tire of the present invention is not particularly limited except that the rubber composition of the present invention is used for any of the tire members, and can be produced according to a conventional method. As the gas to be filled in the tire, in addition to normal air or air with adjusted oxygen partial pressure, inert gas such as nitrogen, argon and helium can be used.

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

(Compounds a to k)
Compounds ak were prepared. The types, melting points, and results of ¹ H-NMR measurement (conditions: 300 MHz, DMSO-d ₆ , δppm) of compounds a to k are shown below.

（融点：１９８℃、¹Ｈ－ＮＭＲ（３００ＭＨｚ，ＤＭＳＯ－ｄ₆，δｐｐｍ）：６．３（ｄ，２Ｈ），７．１（ｔ，１Ｈ），ＮＨ（３Ｈ）及びＯＨ（２Ｈ）は不検出）

・化合物ｂ：２，３－ジヒドロキシベンゾヒドラジド
２，３－ジヒドロキシ安息香酸メチル２．７５ｇ、１００％ヒドラジン一水和物７．００ｇを水１．５ｍLに添加し、１００℃で３時間攪拌した。反応液を濃縮後、析出している固体にイソプロピルアルコールを加えて濾過し、イソプロピルアルコールで洗浄した。得られた固体を減圧乾燥し、淡黄色固体２，３－ジヒドロキシベンゾヒドラジド２．００ｇ（収率７３％）を得た。

（融点：２２３℃、¹Ｈ－ＮＭＲ（３００ＭＨｚ，ＤＭＳＯ－ｄ₆，δｐｐｍ）：４．７（ｂｒ－ｓ，２Ｈ），６．７（ｍ，１Ｈ）， ６．９（ｍ，１Ｈ），７．２（ｍ，１Ｈ），１０．１（ｂｒ－ｓ，１Ｈ），ＯＨ（２Ｈ）は不検出）

・化合物ｃ：２，４－ジヒドロキシベンゾヒドラジド
２，４－ジヒドロキシ安息香酸メチル５．５０ｇ、１００％ヒドラジン一水和物１３．４ｇを水３ｍＬに添加し、１００℃で３時間攪拌した。反応液を濃縮後、析出している固体にイソプロピルアルコールを加えて濾別し、イソプロピルアルコールで洗浄した。得られた固体を減圧乾燥し、淡黄色固体２，４－ジヒドロキシベンゾヒドラジド４．８２ｇ（収率８８％）を得た。

（融点：２３７℃、¹Ｈ－ＮＭＲ（３００ＭＨｚ，ＤＭＳＯ－ｄ₆，δｐｐｍ）：
６．２（ｍ，２Ｈ），７．６（ｍ，１Ｈ），ＮＨ（３Ｈ）及びＯＨ（２Ｈ）は不検出）

・化合物ｄ：２，５－ジヒドロキシベンゾヒドラジド
２，５－ジヒドロキシ安息香酸メチル５．３９ｇ、１００％ヒドラジン一水和物３．２９ｇを１－ブタノール３２ｍＬに添加し、１１７℃で１５時間攪拌した。反応液を冷却後、析出している固体を濾別し、イソプロピルアルコールで洗浄した。得られた固体を減圧乾燥し、淡黄色固体２，５－ジヒドロキシベンゾヒドラジド４．２６ｇ（収率７９％）を得た。

（融点：２１０℃、¹Ｈ－ＮＭＲ（３００ＭＨｚ，ＤＭＳＯ－ｄ₆，δｐｐｍ）：４．６（ｂｒ－ｓ，２Ｈ），６．７（ｍ，１Ｈ）， ６．８（ｍ，１Ｈ），７．２（ｍ，１Ｈ），９．０（ｂｒ－ｓ，１Ｈ），９．９（ｂｒ－ｓ，１Ｈ），１１．５（ｂｒ－ｓ，１Ｈ））

・化合物ｅ：４－アミノ－２－ヒドロキシベンゾヒドラジド
４－アミノ－２－ヒドロキシ安息香酸メチル１２．０ｇ、１００％ヒドラジン一水和物３０．３ｇを水６．６ｍＬに添加し、１００℃で２時間攪拌した。反応液を濃縮後、水を加え、析出した固体を濾別し、水で洗浄した。得られた固体を減圧乾燥し、淡黄色固体４－アミノ－２－ヒドロキシベンゾヒドラジド８．６８ｇ（収率７２％）を得た。

（融点：１９８℃、¹Ｈ－ＮＭＲ（３００ＭＨｚ，ＤＭＳＯ－ｄ₆，δｐｐｍ）：
４．４（ｂｒ－ｓ，２Ｈ），５．７（ｍ，２Ｈ），６．０（ｍ，２Ｈ）， ７．４（ｍ，１Ｈ），９．５（ｍ，１Ｈ），１２．７（ｂｒ－ｓ，１Ｈ））

・化合物ｆ：３，５－ジヒドロキシナフタレン－２－カルボヒドラジド
３，５－ジヒドロキシナフトエ酸４３．０ｇ、濃硫酸４２．０ｍＬをメタノール８６０ｍＬに添加し、６５℃で４４時間攪拌した。反応液を冷却後、水を加え、析出した固体を濾別し、水で洗浄した。得られた固体を減圧乾燥し、淡黄色固体３，５－ジヒドロキシナフタレン－２－カルボン酸メチル４４．７ｇ（収率９７％）を得た。
上記の方法で得た３，５－ジヒドロキシナフタレン－２－カルボン酸メチル８．３９ｇ、１００％ヒドラジン一水和物５．２９ｇをブタノール４０．０ｍＬに添加し、６５℃で２時間攪拌した。反応液を濃縮し、析出した固体をイソプロピルアルコールに懸濁した。析出した固体を濾別し、イソプロピルエーテルで洗浄した。得られた固体を減圧乾燥し、淡黄色固体３，５－ジヒドロキシナフタレン－２－カルボヒドラジド５．０１ｇ（収率６０％）を得た。

（融点：２１９℃、¹Ｈ－ＮＭＲ（３００ＭＨｚ，ＤＭＳＯ－ｄ₆，δｐｐｍ）：
６．８（ｍ，１Ｈ），７．１（ｍ，１Ｈ），７．３（ｍ，１Ｈ）， ７．４（ｓ，１Ｈ），８．３（ｓ，１Ｈ），１０．３（ｂｒ－ｓ，２Ｈ），ＮＨ（３Ｈ）不検出）

・化合物ｇ：４－アミノ－３－ヒドロキシナフタレン－２－カルボヒドラジド
３－ヒドロキシ－２－ナフトエ酸５０．０ｇをクロロホルム２７０ｍＬに加え、氷冷後、６０％硝酸２４．３ｍＬを滴下した。３５分間攪拌した後、析出した固体を濾別し、水、クロロホルムで洗浄した。得られた固体を減圧乾燥し、橙色固体３－ヒドロキシ－４－ニトロ－２－ナフトエ酸４７．７ｇ（収率７７％）を得た。
上記の方法で得た３－ヒドロキシ－４－ニトロ－２－ナフトエ酸１２．５ｇ、濃硫酸１ｍＬをブタノール２００ｍＬに添加し、１１７℃で４８時間攪拌した。反応液を濃縮後、析出している固体を濾別し、ブタノールで洗浄した。得られた固体を減圧乾燥し、黄色固体３－ヒドロキシ－４－ニトロナフタレン－２－カルボン酸ブチル７．５２ｇ（収率４８％）を得た。
上記の方法で得た３－ヒドロキシ－４－ニトロナフタレン－２－カルボン酸ブチル２８．７ｇ、パラジウムカーボン２．９０ｇをメタノール４９４ｍＬに添加し、水素で置換して室温で８時間攪拌した。反応液を濃縮後、得られた固体にヒドラジン一水和物１７．７ｇ、ブタノール３３０ｍＬを加え、７５℃で１３時間攪拌した。反応液を冷却後、析出している固体を濾別し、ブタノールで洗浄した。得られた固体を減圧乾燥し、淡黄色固体４－アミノ－３－ヒドロキシナフタレン－２－カルボヒドラジド２１．１ｇ（収率９８％）を得た。

（融点：１８１℃、¹Ｈ－ＮＭＲ（３００ＭＨｚ，ＤＭＳＯ－ｄ₆，δｐｐｍ）：
４．７（ｂｒ－ｓ，２Ｈ），７．３（ｍ，１Ｈ）， ７，４（ｍ，１Ｈ），７．６（ｍ，１Ｈ），７．７（ｓ，１Ｈ），８．０（ｍ，１Ｈ），１０．４（ｂｒ－ｓ，１Ｈ），ＮＨ（３Ｈ）不検出）

・化合物ｈ：３－ヒドロキシ－４－ニトロナフタレン－２－カルボヒドラジド
３－ヒドロキシ－２－ナフトエ酸５０．０ｇをクロロホルム２７０ｍＬに加え、氷冷後、６０％硝酸２４．３ｍＬを滴下した。３５分間攪拌した後、固体を濾別し、水、クロロホルムで洗浄した。得られた固体を減圧乾燥し、橙色固体３－ヒドロキシ－４－ニトロ－２－ナフトエ酸４７．７ｇ（収率７７％）を得た。
上記の方法で得た３－ヒドロキシ－４－ニトロ－２－ナフトエ酸１２．５ｇ、濃硫酸１ｍＬをブタノール２００ｍＬに添加し、１１７℃で４８時間攪拌した。反応液を濃縮後、析出した固体を濾別し、ブタノールで洗浄した。得られた固体を減圧乾燥し、黄色固体３－ヒドロキシ－４－ニトロナフタレン－２－カルボン酸ブチル７．５２ｇ（収率４８％）を得た。
上記の方法で得た３－ヒドロキシ－４－ニトロナフタレン－２－カルボン酸ブチル１７．１ｇをメタノール１７５ｍＬに溶解し、１００％ヒドラジン一水和物６．２８ｇを添加し、６５℃で１６時間攪拌した。反応液を冷却後、析出した固体を濾別し、メタノールで洗浄した。得られた固体を減圧乾燥し、橙色固体３－ヒドロキシ－４－ニトロナフタレン－２－カルボヒドラジド１４．６ｇ（収率１００％）を得た。

（融点：１８５℃、¹Ｈ－ＮＭＲ（３００ＭＨｚ，ＤＭＳＯ－ｄ₆，δｐｐｍ）：
７．１（ｍ，１Ｈ）， ７．４（ｍ，２Ｈ），７．８（ｍ，１Ｈ），８．４（ｍ，１Ｈ），ＮＨ（３Ｈ），ＯＨ（１Ｈ）不検出）

・化合物ｉ：１，３－ジヒドロキシナフタレン－２－カルボヒドラジド
マロン酸ジエチル５．００ｇのアセトニトリル５０ｍＬ溶液に塩化マグネシウム２．９７ｇを加え、氷冷した。次に、トリエチルアミン６．３０ｇを滴下して３０分間攪拌した後、フェニル酢酸クロリド４．８２ｇを滴下し、室温に戻し、４．５時間攪拌した。再び反応液を氷冷し、２Ｎ塩酸２００ｍＬを加え、酢酸エチルで抽出し、有機層を飽和食塩水で洗浄した。無水硫酸マグネシウムで乾燥し、濃縮後、減圧乾燥した。得られた淡黄色油状物残渣を氷冷し、濃硫酸１５ｍＬを滴下し、室温に戻して１７時間攪拌した。反応液を氷冷し、氷水３５ｍＬをゆっくり加え、析出した固体を濾別し、水洗した。得られた固体を減圧乾燥し、黄色固体１，３－ジヒドロキシナフタレン－２－カルボン酸エチル６．０９ｇ（収率８４％）を得た。
上記の方法で得た１，３－ジヒドロキシナフタレン－２－カルボン酸エチル８００ｍｇのメタノール３ｍＬ溶液に室温で１００％ヒドラジン一水和物０．２１ｇを加え、２．５時間加熱還流し、室温に戻して１２時間攪拌した。析出した固体を濾別し、得られた固体をメタノールで洗浄し、減圧乾燥して黄土色固体１，３－ジヒドロキシナフタレン－２－カルボヒドラジド５４０ｍｇ（収率７２％）を得た。

（融点：２０５℃、¹Ｈ－ＮＭＲ（３００ＭＨｚ，ＤＭＳＯ－ｄ₆，δｐｐｍ）：
６．６（ｓ，１Ｈ）， ７．２（ｍ，１Ｈ），７．４（ｍ，１Ｈ），７．５（ｄ，１Ｈ），８．０（ｄ，１Ｈ），ＮＨ（３Ｈ），ＯＨ（２Ｈ）不検出）

・化合物ｊ：２，４，６－トリヒドロキシベンゾヒドラジド
２，４，６－トリヒドロキシ安息香酸１水和物１０．０ｇのアセトン１００ｍＬ溶液に、室温で炭酸ナトリウム２．９６ｇを加えて１０分間攪拌し、ジメチル硫酸７．０４ｇを加えて５０℃に昇温し、５時間攪拌した。反応液を濃縮し、水を加えて酢酸エチルで抽出し、有機層を飽和食塩水で洗浄した。更に無水硫酸マグネシウムで乾燥し、濃縮後、析出した固体を酢酸エチルとヘキサンの混合溶媒に懸濁して濾別し、減圧乾燥してピンク色固体２，４，６－トリヒドロキシ安息香酸メチル６．０３ｇ（収率６２％）を得た。
上記の方法で得た２，４，６－トリヒドロキシ安息香酸メチル２．４０ｇをメタノール１０ｍＬに懸濁させ、室温で１００％ヒドラジン一水和物０．９８ｇを加え、１．５時間加熱還流し、室温に戻して１２時間攪拌した。析出した固体を濾別し、得られた固体をメタノールで洗浄し、減圧乾燥してベージュ色固体２，４，６－トリヒドロキシベンゾヒドラジド９６０ｍｇ（収率４０％）を得た。

（融点：２０７℃、¹Ｈ－ＮＭＲ（３００ＭＨｚ，ＤＭＳＯ－ｄ₆，δｐｐｍ）：
４．３（ｂｒ－ｓ，２Ｈ），５．８（ｓ，２Ｈ），７．２（ｓ，１Ｈ），９．３（ｂｒ－ｓ，１Ｈ），１２．３（ｂｒ－ｓ，２Ｈ））

・化合物ｋ：２，６－ジヒドロキシ－４－メチルベンゾヒドラジド
２，６－ジヒドロキシ－４－メチル安息香酸５．００ｇのアセトン５０ｍＬ溶液に、室温で炭酸ナトリウム１．６６ｇを加えて１０分間攪拌し、ジメチル硫酸３．９４ｇを加えて５０℃に昇温し、５時間攪拌した。反応液を濃縮し、水を加えて酢酸エチルで抽出し、有機層を飽和食塩水で洗浄した。更に無水硫酸マグネシウムで乾燥し、濃縮後、析出した固体を冷ヘキサンに懸濁して濾別し、減圧乾燥して白色固体２，６－ジヒドロキシ－４－メチル安息香酸メチル４．９４ｇ（収率９１％）を得た。
上記の方法で得た２，６－ジヒドロキシ－４－メチル安息香酸メチル４．５０ｇをメタノール１２ｍＬに懸濁させ、室温で１００％ヒドラジン一水和物１．８５ｇを加え、１２時間加熱還流した。室温に戻し、析出した固体を濾別し、得られた固体をメタノールで洗浄し、減圧乾燥してピンク色固体２，６－ジヒドロキシ－４－メチルベンゾヒドラジド３．０９ｇ（収率６９％）を得た。

（融点：１８０℃、¹Ｈ－ＮＭＲ（３００ＭＨｚ，ＤＭＳＯ－ｄ₆，δｐｐｍ）：
２．１４（ｓ，３Ｈ），５．１（ｂｒ－ｓ，２Ｈ），６．１（ｓ，２Ｈ），９．９（ｂｒ－ｓ，１Ｈ），１２．５（ｂｒ－ｓ，２Ｈ））Compound a: 2,6-dihydroxybenzohydrazide 5.29 g of methyl 2,6-dihydroxybenzoate and 3.30 g of 100% hydrazine monohydrate were added to 32 mL of 1-butanol and stirred at 117° C. for 15 hours. After cooling the reaction solution, the precipitated solid was filtered and washed with isopropyl alcohol. The resulting solid was dried under reduced pressure to obtain 2.85 g of pale yellow solid 2,6-dihydroxybenzohydrazide (yield 54%).

(melting point: 198° C., ¹ H-NMR (300 MHz, DMSO-d ₆ , δ ppm): 6.3 (d, 2H), 7.1 (t, 1H), NH (3H) and OH (2H) detection)

Compound b: 2,3-dihydroxybenzohydrazide 2.75 g of methyl 2,3-dihydroxybenzoate and 7.00 g of 100% hydrazine monohydrate were added to 1.5 mL of water and stirred at 100° C. for 3 hours. After concentrating the reaction solution, isopropyl alcohol was added to the precipitated solid, filtered, and washed with isopropyl alcohol. The resulting solid was dried under reduced pressure to obtain 2.00 g of pale yellow solid 2,3-dihydroxybenzohydrazide (yield 73%).

(melting point: 223° C., ¹ H-NMR (300 MHz, DMSO-d ₆ , δ ppm): 4.7 (br-s, 2H), 6.7 (m, 1H), 6.9 (m, 1H), 7.2 (m, 1H), 10.1 (br-s, 1H), OH (2H) not detected)

• Compound c: 2,4-dihydroxybenzohydrazide 5.50 g of methyl 2,4-dihydroxybenzoate and 13.4 g of 100% hydrazine monohydrate were added to 3 mL of water and stirred at 100°C for 3 hours. After concentrating the reaction solution, isopropyl alcohol was added to the precipitated solid, the solid was separated by filtration, and washed with isopropyl alcohol. The obtained solid was dried under reduced pressure to obtain 4.82 g of pale yellow solid 2,4-dihydroxybenzohydrazide (yield 88%).

(Melting point: 237° C., ¹ H-NMR (300 MHz, DMSO-d ₆ , δ ppm):
6.2 (m, 2H), 7.6 (m, 1H), NH (3H) and OH (2H) not detected)

Compound d: 2,5-dihydroxybenzohydrazide 5.39 g of methyl 2,5-dihydroxybenzoate and 3.29 g of 100% hydrazine monohydrate were added to 32 mL of 1-butanol and stirred at 117° C. for 15 hours. After cooling the reaction solution, the precipitated solid was separated by filtration and washed with isopropyl alcohol. The resulting solid was dried under reduced pressure to obtain 4.26 g of pale yellow solid 2,5-dihydroxybenzohydrazide (yield 79%).

(melting point: 210° C., ¹ H-NMR (300 MHz, DMSO-d ₆ , δ ppm): 4.6 (br-s, 2H), 6.7 (m, 1H), 6.8 (m, 1H), 7.2 (m, 1H), 9.0 (br-s, 1H), 9.9 (br-s, 1H), 11.5 (br-s, 1H))

Compound e: 4-amino-2-hydroxybenzohydrazide 12.0 g of methyl 4-amino-2-hydroxybenzoate and 30.3 g of 100% hydrazine monohydrate are added to 6.6 mL of water, and Stirred for hours. After concentrating the reaction solution, water was added, and the precipitated solid was separated by filtration and washed with water. The resulting solid was dried under reduced pressure to obtain 8.68 g of pale yellow solid 4-amino-2-hydroxybenzohydrazide (yield 72%).

(Melting point: 198° C., ¹ H-NMR (300 MHz, DMSO-d ₆ , δ ppm):
4.4 (br-s, 2H), 5.7 (m, 2H), 6.0 (m, 2H), 7.4 (m, 1H), 9.5 (m, 1H), 12.7 (br-s, 1H))

Compound f: 3,5-dihydroxynaphthalene-2-carbohydrazide 43.0 g of 3,5-dihydroxynaphthoic acid and 42.0 mL of concentrated sulfuric acid were added to 860 mL of methanol and stirred at 65° C. for 44 hours. After cooling the reaction solution, water was added, and the precipitated solid was separated by filtration and washed with water. The resulting solid was dried under reduced pressure to obtain 44.7 g of methyl 3,5-dihydroxynaphthalene-2-carboxylate as a pale yellow solid (yield 97%).
8.39 g of methyl 3,5-dihydroxynaphthalene-2-carboxylate obtained by the above method and 5.29 g of 100% hydrazine monohydrate were added to 40.0 mL of butanol and stirred at 65° C. for 2 hours. The reaction solution was concentrated, and the precipitated solid was suspended in isopropyl alcohol. The precipitated solid was filtered off and washed with isopropyl ether. The resulting solid was dried under reduced pressure to obtain 5.01 g of pale yellow solid 3,5-dihydroxynaphthalene-2-carbohydrazide (yield 60%).

(Melting point: 219° C., ¹ H-NMR (300 MHz, DMSO-d ₆ , δ ppm):
6.8 (m, 1H), 7.1 (m, 1H), 7.3 (m, 1H), 7.4 (s, 1H), 8.3 (s, 1H), 10.3 (br -s, 2H), NH (3H) not detected)

Compound g: 4-amino-3-hydroxynaphthalene-2-carbohydrazide 50.0 g of 3-hydroxy-2-naphthoic acid was added to 270 mL of chloroform, and after cooling with ice, 24.3 mL of 60% nitric acid was added dropwise. After stirring for 35 minutes, the precipitated solid was filtered off and washed with water and chloroform. The obtained solid was dried under reduced pressure to obtain 47.7 g of orange solid 3-hydroxy-4-nitro-2-naphthoic acid (yield 77%).
12.5 g of 3-hydroxy-4-nitro-2-naphthoic acid obtained by the above method and 1 mL of concentrated sulfuric acid were added to 200 mL of butanol and stirred at 117° C. for 48 hours. After concentrating the reaction solution, the precipitated solid was separated by filtration and washed with butanol. The resulting solid was dried under reduced pressure to obtain 7.52 g of yellow solid butyl 3-hydroxy-4-nitronaphthalene-2-carboxylate (yield 48%).
28.7 g of butyl 3-hydroxy-4-nitronaphthalene-2-carboxylate obtained by the above method and 2.90 g of palladium carbon were added to 494 mL of methanol, replaced with hydrogen, and stirred at room temperature for 8 hours. After concentrating the reaction solution, 17.7 g of hydrazine monohydrate and 330 mL of butanol were added to the obtained solid, and the mixture was stirred at 75° C. for 13 hours. After cooling the reaction solution, the precipitated solid was separated by filtration and washed with butanol. The resulting solid was dried under reduced pressure to obtain 21.1 g of pale yellow solid 4-amino-3-hydroxynaphthalene-2-carbohydrazide (yield 98%).

(Melting point: 181° C., ¹ H-NMR (300 MHz, DMSO-d ₆ , δ ppm):
4.7 (br-s, 2H), 7.3 (m, 1H), 7, 4 (m, 1H), 7.6 (m, 1H), 7.7 (s, 1H), 8.0 (m, 1H), 10.4 (br-s, 1H), NH (3H) not detected)

Compound h: 3-hydroxy-4-nitronaphthalene-2-carbohydrazide 50.0 g of 3-hydroxy-2-naphthoic acid was added to 270 mL of chloroform, and after cooling with ice, 24.3 mL of 60% nitric acid was added dropwise. After stirring for 35 minutes, the solid was filtered off and washed with water and chloroform. The obtained solid was dried under reduced pressure to obtain 47.7 g of orange solid 3-hydroxy-4-nitro-2-naphthoic acid (yield 77%).
12.5 g of 3-hydroxy-4-nitro-2-naphthoic acid obtained by the above method and 1 mL of concentrated sulfuric acid were added to 200 mL of butanol and stirred at 117° C. for 48 hours. After concentrating the reaction solution, the precipitated solid was separated by filtration and washed with butanol. The resulting solid was dried under reduced pressure to obtain 7.52 g of yellow solid butyl 3-hydroxy-4-nitronaphthalene-2-carboxylate (yield 48%).
17.1 g of butyl 3-hydroxy-4-nitronaphthalene-2-carboxylate obtained by the above method was dissolved in 175 mL of methanol, 6.28 g of 100% hydrazine monohydrate was added, and the mixture was stirred at 65° C. for 16 hours. bottom. After cooling the reaction solution, the precipitated solid was filtered off and washed with methanol. The obtained solid was dried under reduced pressure to obtain 14.6 g of orange solid 3-hydroxy-4-nitronaphthalene-2-carbohydrazide (yield 100%).

(Melting point: 185° C., ¹ H-NMR (300 MHz, DMSO-d ₆ , δ ppm):
7.1 (m, 1H), 7.4 (m, 2H), 7.8 (m, 1H), 8.4 (m, 1H), NH (3H), OH (1H) not detected)

• Compound i: 1,3-dihydroxynaphthalene-2-carbohydrazide To a solution of 5.00 g of diethyl malonate in 50 mL of acetonitrile was added 2.97 g of magnesium chloride and cooled with ice. Next, 6.30 g of triethylamine was added dropwise and stirred for 30 minutes, then 4.82 g of phenylacetic acid chloride was added dropwise, the temperature was returned to room temperature, and the mixture was stirred for 4.5 hours. The reaction mixture was ice-cooled again, 200 mL of 2N hydrochloric acid was added, extracted with ethyl acetate, and the organic layer was washed with saturated brine. It was dried over anhydrous magnesium sulfate, concentrated, and dried under reduced pressure. The resulting pale yellow oil residue was ice-cooled, 15 mL of concentrated sulfuric acid was added dropwise, the temperature was returned to room temperature, and the mixture was stirred for 17 hours. The reaction solution was ice-cooled, 35 mL of ice water was slowly added, and the precipitated solid was separated by filtration and washed with water. The resulting solid was dried under reduced pressure to obtain 6.09 g of ethyl 1,3-dihydroxynaphthalene-2-carboxylate as a yellow solid (yield 84%).
0.21 g of 100% hydrazine monohydrate was added to a solution of 800 mg of ethyl 1,3-dihydroxynaphthalene-2-carboxylate in 3 mL of methanol at room temperature, the mixture was heated under reflux for 2.5 hours, and the temperature was returned to room temperature. and stirred for 12 hours. The precipitated solid was separated by filtration, washed with methanol and dried under reduced pressure to obtain 540 mg of ocher-colored solid 1,3-dihydroxynaphthalene-2-carbohydrazide (yield 72%).

(Melting point: 205° C., ¹ H-NMR (300 MHz, DMSO-d ₆ , δ ppm):
6.6 (s, 1H), 7.2 (m, 1H), 7.4 (m, 1H), 7.5 (d, 1H), 8.0 (d, 1H), NH(3H), OH (2H) not detected)

- Compound j: 2,4,6-trihydroxybenzohydrazide To a solution of 10.0 g of 2,4,6-trihydroxybenzoic acid monohydrate in 100 mL of acetone, 2.96 g of sodium carbonate was added at room temperature and stirred for 10 minutes. Then, 7.04 g of dimethyl sulfate was added, the temperature was raised to 50° C., and the mixture was stirred for 5 hours. The reaction mixture was concentrated, water was added, the mixture was extracted with ethyl acetate, and the organic layer was washed with saturated brine. After further drying over anhydrous magnesium sulfate and concentration, the precipitated solid was suspended in a mixed solvent of ethyl acetate and hexane, filtered and dried under reduced pressure to give a pink solid methyl 2,4,6-trihydroxybenzoate6. 03 g (62% yield) was obtained.
2.40 g of methyl 2,4,6-trihydroxybenzoate obtained by the above method was suspended in 10 mL of methanol, 0.98 g of 100% hydrazine monohydrate was added at room temperature, and the mixture was heated under reflux for 1.5 hours. , the mixture was returned to room temperature and stirred for 12 hours. The precipitated solid was separated by filtration, and the obtained solid was washed with methanol and dried under reduced pressure to obtain 960 mg of beige solid 2,4,6-trihydroxybenzohydrazide (yield 40%).

(Melting point: 207° C., ¹ H-NMR (300 MHz, DMSO-d ₆ , δ ppm):
4.3 (br-s, 2H), 5.8 (s, 2H), 7.2 (s, 1H), 9.3 (br-s, 1H), 12.3 (br-s, 2H) )

- Compound k: 2,6-dihydroxy-4-methylbenzohydrazide To a solution of 5.00 g of 2,6-dihydroxy-4-methylbenzoic acid in 50 mL of acetone, 1.66 g of sodium carbonate was added at room temperature and stirred for 10 minutes, 3.94 g of dimethyl sulfate was added, the temperature was raised to 50° C., and the mixture was stirred for 5 hours. The reaction mixture was concentrated, water was added, the mixture was extracted with ethyl acetate, and the organic layer was washed with saturated brine. After further drying over anhydrous magnesium sulfate and concentration, the precipitated solid was suspended in cold hexane, filtered off, and dried under reduced pressure to yield 4.94 g of white solid methyl 2,6-dihydroxy-4-methylbenzoate (yield 91). %) was obtained.
4.50 g of methyl 2,6-dihydroxy-4-methylbenzoate obtained by the above method was suspended in 12 mL of methanol, 1.85 g of 100% hydrazine monohydrate was added at room temperature, and the mixture was heated under reflux for 12 hours. After returning to room temperature, the precipitated solid was separated by filtration, and the obtained solid was washed with methanol and dried under reduced pressure to give 3.09 g of pink solid 2,6-dihydroxy-4-methylbenzohydrazide (yield 69%). Obtained.

(Melting point: 180° C., ¹ H-NMR (300 MHz, DMSO-d ₆ , δ ppm):
2.14 (s, 3H), 5.1 (br-s, 2H), 6.1 (s, 2H), 9.9 (br-s, 1H), 12.5 (br-s, 2H) )

<Examples 1 to 21, Comparative Examples 1 to 3>
Samples of rubber compositions were prepared according to the component composition in Table 1. The compounding amount of each component is expressed in parts by mass with respect to 100 parts by mass of the rubber component.

<Evaluation>
The rubber composition samples obtained were evaluated as follows.
(1) Low heat build-up (tan δ index)
The rubber composition of each sample was vulcanized at 145° C. for 33 minutes to obtain a vulcanized rubber. The loss tangent (tan δ) of the obtained vulcanized rubber was measured at a temperature of 50° C., a strain of 5%, and a frequency of 15 Hz using a viscoelasticity measuring device [manufactured by Rheometrics Co., Ltd.].
The measured tan δ was reciprocated and then multiplied by 100, and indicated as an exponent value when the reciprocal value of tan δ of Comparative Example 2×100 is 100. A larger index value indicates better low heat build-up. Evaluation results are shown in Table 1.

(2) Wear resistance (wear index)
Each sample rubber composition was vulcanized at 145° C. for 33 minutes to obtain a vulcanized rubber. Using a disc-shaped (diameter 16.2 mm × thickness 6 mm) test piece cut out from each vulcanized rubber obtained, a DIN abrasion test was performed according to JIS-K6264-2:2005, and DIN abrasion was performed at room temperature. The wear amount (mm ³ ) was measured during the test.
As for the amount of wear measured in each sample, the reciprocal of the amount of wear of each sample is shown as the wear index when the reciprocal of the amount of wear in Comparative Example 2 is 100. The larger the index value, the smaller the amount of wear and the better the wear resistance. Evaluation results are shown in Table 1.

(3) Processability evaluation (Mooney viscosity index)
The rubber composition of each sample was measured for Mooney viscosity according to JIS K 6300-1:2001 (Mooney viscosity, Mooney scorch time).
The measured Mooney viscosity was multiplied by 100 after taking the reciprocal. Regarding the Mooney viscosity index, a higher value indicates a lower unvulcanized viscosity and better workability.

*1: RSS#1
*2: "#80" manufactured by Asahi Carbon Co., Ltd.
*3: 3-Hydroxy-N'-(1,3-dimethylbutylidene)-2-naphthoic acid hydrazide synthesized by the following method, not applicable to the compound represented by formula (I) (synthesis method)
A reactor equipped with a Dean-Stark reflux condenser and a stirrer was charged with 500 ml of methyl isobutyl ketone and 50.5 g (0.25 mol) of 3-hydroxy-2-naphthoic acid hydrazide, heated and distilled. The mixture was heated to reflux for 5 hours while removing the remaining water. After cooling the reaction solution to 20° C., the precipitated crystals were filtered off and dried under reduced pressure to obtain slightly yellow crystals (67.6 g, yield 95%). As a result of NMR and IR analysis, the slightly yellow crystals were found to be 3-hydroxy-N'-(1,3-dimethylbutylidene)-2-naphthoic acid hydrazide as shown below.
(Melting point 146° C., 1H-NMR (DMSO) 0.90 (m, 6H), 1.93 (s, 3H), 2.00 (m, 1H), 2.17 (m, 2H), 7.38 (m, 2H), 7.46 (m, 1H), 7.75 (m, 1H), 7.95 (m, 1H), 8.58 (m, 1H), 11.15 (b, 1H) . 600, 550, 480 cm ^-1 )
*4: "A/O MIX" manufactured by Sankyo Yuka Kogyo Co., Ltd.
*5: N-Phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine, "Nocrac 6C" manufactured by Ouchi Shinko Chemical Industry Co., Ltd.
*6: 2,2,4-trimethyl-1,2-dihydroquinoline polymer, "Nocrac 224" manufactured by Ouchi Shinko Chemical Industry Co., Ltd.
*7: N-Cyclohexyl-2-benzothiazole sulfenamide, "Suncellar CM" manufactured by Sanshin Chemical Industry Co., Ltd.
*8: 2,2'-methylenebis(4-methyl-6-tert-butylphenol), "Nocrac NS-6" manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd., molecular weight: 341
*9: 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), "Nocrac NS-30" manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd., molecular weight: 383
*10: 2,6-di-tert-butyl-4-methylphenol, "Nocrac 200" manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd., molecular weight: 220
*11: 1′-Hydroxy[2,2′-methylenebis(4-methyl-6-tert-butylbenzene)]-1-yl acrylate, “Sumilizer GM” manufactured by Sumitomo Chemical Co., Ltd., molecular weight: 395
*12: 1'-Hydroxy[2,2'-ethylidenebis[4,6-bis(1,1-dimethylpropyl)benzene]]-1-yl acrylate, "Sumilizer GS" manufactured by Sumitomo Chemical Co., Ltd., Molecular weight: 548

For each example and comparative example, the total value of Mooney viscosity index, tan δ index, and wear index was calculated and used as a comprehensive evaluation. The higher the overall evaluation, the higher the workability, low heat build-up and wear resistance.
From the results in Table 1, the rubber composition of each example has a higher overall evaluation than the rubber composition of each comparative example, and can achieve both workability, low heat build-up, and wear resistance at a high level. I understand.

ADVANTAGE OF THE INVENTION According to this invention, the rubber composition excellent in low heat build-up property, abrasion resistance, and workability can be provided. Moreover, according to the present invention, it is possible to provide a tire having low heat build-up and excellent productivity.

Claims (14)

A rubber component containing a diene rubber, a filler containing carbon black , a compound represented by the following formula (I), and an antioxidant containing a compound having a phenol group ,
The content of the compound represented by the formula (I) is 0.05 to 30 parts by mass with respect to 100 parts by mass of the rubber component,
A rubber composition, wherein the content of the carbon black is 10 to 160 parts by mass with respect to 100 parts by mass of the rubber component.

(In the formula, A is a phenyl group or a naphthyl group, has at least two polar groups, and the polar groups may be the same or different. Both ^{R 1} and R ² are hydrogen atoms.) 2. The rubber composition according to claim 1, wherein at least one of the polar groups of A in the compound represented by formula (I) is a hydroxyl group, an amino group or a nitro group. 3. The rubber composition according to claim 2, wherein at least one of the polar groups of A in the compound represented by formula (I) is a hydroxyl group. 4. The rubber composition according to claim 3, wherein at least two of the polar groups of A in the compound represented by formula (I) are hydroxyl groups. The rubber composition according to any one of claims 1 to 4, wherein the compound represented by formula (I) has a molecular weight of 250 or less. The rubber composition according to any one of claims 1 to 5, wherein the compound represented by formula (I) has a melting point of 80°C or higher and lower than 250°C. The compound represented by formula (I) is 2,6-dihydroxybenzohydrazide, 2,3-dihydroxybenzohydrazide, 2,4-dihydroxybenzohydrazide, 2,5-dihydroxybenzohydrazide, 4-amino-2- Hydroxybenzohydrazide, 3,5-dihydroxynaphthalene-2-carbohydrazide, 4-amino-3-hydroxynaphthalene-2-carbohydrazide, 3-hydroxy-4-nitronaphthalene-2-carbohydrazide, 1,3-dihydroxynaphthalene -2-carbohydrazide, 2,4,6-trihydroxybenzohydrazide, and 2,6-dihydroxy-4-methylbenzohydrazide, at least one selected from the group consisting of claims 1- 7. The rubber composition according to any one of 6 . The rubber composition according to any one of claims 1 to 7 , wherein the diene rubber is natural rubber. The rubber composition according to any one of claims 1 to 8 , characterized in that the content of said filler is 10 to 160 parts by mass with respect to 100 parts by mass of said rubber component. The rubber composition according to any one of claims 1 to 9 , wherein the compound having a phenol group has a ratio of molecular weight to the number of phenol groups of 250 or less. The rubber composition according to any one of claims 1 to 10 , wherein the total content of the anti-aging agent is 0.05 to 10 parts by mass with respect to 100 parts by mass of the rubber component. thing. The rubber composition according to any one of claims 1 to 11 , wherein the proportion of the compound having a phenol group in the antioxidant is 20 to 100 mass%. Any one of claims 1 to 12 , wherein the anti-aging agent further contains an amine-based anti-aging agent, and the proportion of the amine-based anti-aging agent in the anti-aging agent is 80% by mass or less. 1. The rubber composition according to claim 1. A tire characterized by using the rubber composition according to any one of claims 1 to 13 .