Method for producing modified hydrogenated conjugated diene rubber, rubber composition, and tire

Abstract

To provide a method for producing a modified hydrogenated conjugated diene rubber that allows easy vulcanization, a rubber composition, and a tire.SOLUTION: A method for producing a modified hydrogenated conjugated diene rubber is provided, whereby the modified hydrogenated conjugated diene rubber is produced by reacting a hydrogenated conjugated diene rubber, which has a conjugated diene unit 1 containing a repeating unit having a carbon-carbon double bond and a hydrogenated conjugated diene unit 3, and in which a content of the conjugated diene unit 1 is 90 mass% or less in a total amount of the conjugated diene unit 1 and the hydrogenated conjugated diene unit 3, with a conjugated diene rubber containing a repeating unit having a carbon-carbon double bond, in the presence of a metathesis catalyst. Also provided are: a modified hydrogenated conjugated diene rubber produced by the above method; a rubber composition containing the modified hydrogenated conjugated diene rubber and sulfur; and a tire produced by using the rubber composition.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for producing a modified hydrogenated conjugated diene rubber, a rubber composition, and a tire. [Background technology]

[0002] Rubber compositions containing hydrogenated SBR are known (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-26685 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present inventors have studied the rubber composition disclosed in Patent Document 1 and have found that when the rubber composition contains hydrogenated SBR, there is a drawback in that the hydrogenated SBR is difficult to vulcanize.

[0005] Therefore, an object of the present invention is to provide a method for producing a modified hydrogenated conjugated diene rubber which is easily vulcanized. Another object of the present invention is to provide a modified hydrogenated conjugated diene rubber, a rubber composition, and a tire. [Means for solving the problem]

[0006] As a result of intensive research into solving the above problems, the present inventors have found that the problems can be solved by the following configuration.

[0007] [1] A method for producing a modified hydrogenated conjugated diene rubber, comprising reacting a hydrogenated conjugated diene rubber having a repeating unit having a carbon-carbon double bond and a hydrogenated conjugated diene unit 3, in which the content of the conjugated diene unit 1 is 90 mass% or less of a total amount of the conjugated diene unit 1 and the hydrogenated conjugated diene unit 3, with a conjugated diene rubber having a repeating unit having a carbon-carbon double bond, in the presence of a metathesis catalyst, to produce a modified hydrogenated conjugated diene rubber. [2] The method for producing a modified hydrogenated conjugated diene rubber according to [1], wherein the content of the conjugated diene unit 1 is 10 to 90 mass % or less of the total amount of the conjugated diene unit 1 and the hydrogenated conjugated diene unit 3. [3] The method for producing a modified hydrogenated conjugated diene rubber according to [1] or [2], wherein the conjugated diene rubber has a weight average molecular weight of 10,000 to 2,000,000. [4] A modified hydrogenated conjugated diene rubber produced by the method for producing a modified hydrogenated conjugated diene rubber according to any one of [1] to [3]. [5] The modified hydrogenated conjugated diene rubber according to [4], wherein the weight average molecular weight of the modified hydrogenated conjugated diene rubber is 10,000 or more. [6] The modified hydrogenated conjugated diene rubber according to [4] or [5], which has a conjugated diene unit 2 and a hydrogenated conjugated diene unit 4, and the content of the conjugated diene unit 2 is 30 mass% or more of the total amount of the conjugated diene unit 2 and the hydrogenated conjugated diene unit 4. [7] The modified hydrogenated conjugated diene rubber has 2 conjugated diene units and 4 hydrogenated conjugated diene units, The modified hydrogenated conjugated diene rubber according to any one of [4] to [6], wherein the content of the repeating unit having a vinylene group in the conjugated diene unit 2 is 10 to 90 mass % in the total amount of the conjugated diene unit 2 and the hydrogenated conjugated diene unit 4. [8] The modified hydrogenated conjugated diene rubber has 2 conjugated diene units and 4 hydrogenated conjugated diene units, The modified hydrogenated conjugated diene rubber according to any one of [4] to [7], wherein the content of the repeating unit having a vinyl group in the conjugated diene unit 2 is 10 to 80 mass % in the total amount of the conjugated diene unit 2 and the hydrogenated conjugated diene unit 4. [9] A rubber composition comprising the modified hydrogenated conjugated diene rubber according to any one of [4] to [8] and sulfur.

[10] A tire manufactured using the rubber composition described in [9]. Effect of the Invention

[0008] According to the present invention, a method for producing a modified hydrogenated conjugated diene rubber which is easily vulcanized can be provided. The present invention also provides a modified hydrogenated conjugated diene rubber, a rubber composition, and a tire that are easily vulcanized. [Brief description of the drawings]

[0009] [Figure 1] 1 is a partial cross-sectional schematic view of a tire showing an example of an embodiment of a tire of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention will be described in detail below. The following description of the components may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. In the present specification, each component may be used alone or in combination of two or more kinds. In this specification, when two or more types of a component are used in combination, the "content" of the component means the total content of those two or more types, unless otherwise specified. In the present specification, the method for producing each component is not particularly limited unless otherwise specified. For example, a conventionally known method may be used.

[0011] [Method for producing modified hydrogenated conjugated diene rubber] The method for producing the modified hydrogenated conjugated diene rubber of the present invention (the method for producing the modified hydrogenated conjugated diene rubber of the present invention) is as follows: A method for producing a modified hydrogenated conjugated diene rubber, comprising reacting a hydrogenated conjugated diene rubber having a repeating unit having a carbon-carbon double bond and a hydrogenated conjugated diene unit 3, in which the content of the conjugated diene unit 1 is 90 mass% or less of the total amount of the conjugated diene unit 1 and the hydrogenated conjugated diene unit 3, with a conjugated diene rubber having a repeating unit having a carbon-carbon double bond, in the presence of a metathesis catalyst, to produce a modified hydrogenated conjugated diene rubber.

[0012] In this specification, the conjugated diene units 1 refer to all repeating units formed by conjugated dienes and having a carbon-carbon double bond in the hydrogenated conjugated diene rubber. The same applies to the conjugated diene units 2 in the modified hydrogenated conjugated diene rubber. In this specification, the hydrogenated conjugated diene units 3 refer to all repeating units formed by hydrogenated conjugated diene in the hydrogenated conjugated diene rubber. The same applies to the hydrogenated conjugated diene units 4 in the modified hydrogenated conjugated diene rubber.

[0013] The reason why the modified hydrogenated conjugated diene rubber obtained by the production method of the present invention having the above configuration (the modified hydrogenated conjugated diene rubber of the present invention) can solve the problems of the present invention is not necessarily clear, but the present inventors speculate as follows. Note that the following speculation does not limit the mechanism by which the effect is obtained. In other words, even if the effect is obtained by a mechanism other than the following, it is included in the scope of the present invention. Generally, hydrogenated conjugated diene rubber obtained by hydrogenating a conjugated diene rubber is difficult to vulcanize because the repeating units formed by the conjugated diene that constitute the rubber have fewer carbon-carbon double bonds, such as vinyl groups and / or vinylene groups, than before hydrogenation. However, in the production method of the present invention, the conjugated diene unit 1 containing a repeating unit having a carbon-carbon double bond in the hydrogenated conjugated diene rubber reacts with the conjugated diene rubber containing a repeating unit having a carbon-carbon double bond in the presence of a metathesis catalyst (metathesis reaction), thereby introducing a carbon-carbon double bond derived from the conjugated diene rubber into the hydrogenated conjugated diene rubber, and the content of repeating units having a carbon-carbon double bond in the resulting modified hydrogenated conjugated diene rubber can be increased compared to the hydrogenated conjugated diene rubber. As a result, it is presumed that the modified hydrogenated conjugated diene rubber obtained by the production method of the present invention is easier to vulcanize.

[0014] The modified hydrogenated conjugated diene rubber produced by the production method of the present invention (the modified hydrogenated conjugated diene rubber of the present invention) is considered to have a structure derived from the conjugated diene rubber by a reaction in the presence of a metathesis catalyst (metathesis reaction). 1 =C 2 Compounds A and C having 3 =C 4 is an exchange reaction between compound B with C 1 =C 3 , C 1 =C 4 , C 2 =C 3 , C 2 =C 4 In the present invention, the combinations of exchanges in the metathesis reaction are diverse and complex, so that it is possible to produce at least a compound having each of the following (C 1 =C 2 Examples of the vinylene group and vinyl group that the hydrogenated conjugated diene rubber may have include C 3 =C 4Examples of the groups include vinylene groups or vinyl groups that the conjugated diene rubber may have. Metathesis reactions between hydrogenated conjugated diene rubbers and between conjugated diene rubbers may also occur. ), it is impossible or almost impractical to specify the specific structure of the modified hydrogenated conjugated diene rubber obtained. In the present invention, it is considered that the desired effect is obtained by introducing a structure derived from the conjugated diene rubber. Therefore, it is impossible or almost impractical to directly specify the structure of the modified hydrogenated conjugated diene rubber produced by the production method of the present invention.

[0015] [Hydrogenated conjugated diene rubber] In the production method of the present invention, the hydrogenated conjugated diene rubber used as a raw material has conjugated diene units 1 containing repeating units having a carbon-carbon double bond and hydrogenated conjugated diene units 3. In the present invention, the content of the conjugated diene units 1 is 90 mass % or less of the total amount of the conjugated diene units 1 and the hydrogenated conjugated diene units 3.

[0016] [Conjugated diene unit 1] In the present invention, the hydrogenated conjugated diene rubber has a conjugated diene unit 1, and the conjugated diene unit 1 includes a repeating unit having a carbon-carbon double bond. The repeating unit having the carbon-carbon double bond is a repeating unit constituted by a conjugated diene. The repeating unit contained in the conjugated diene unit 1 may have, as the carbon-carbon double bond, for example, a vinyl group (for example, a vinyl group contained in a 1,2-vinyl bond when the conjugated diene is 1,3-butadiene) or a vinylene group (for example, a vinylene group contained in a 1,4-bond when the conjugated diene is 1,3-butadiene).

[0017] The conjugated diene as a monomer capable of forming the conjugated diene unit 1 is not particularly limited. For example, butadiene (e.g., 1,3-butadiene), chloroprene, etc. are included. Among them, it is preferable that the conjugated diene contains 1,3-butadiene.

[0018] [Hydrogenated conjugated diene unit 3] In the present invention, the hydrogenated conjugated diene rubber has 3 hydrogenated conjugated diene units. One of the preferred embodiments of the hydrogenated conjugated diene unit 3 is a unit obtained by hydrogenating (hydrogenating) the above-mentioned conjugated diene unit 1. In the above-mentioned case, in the hydrogenated conjugated diene unit 3, the vinyl group and vinylene group that the conjugated diene unit 1 may have are hydrogenated. The hydrogenated conjugated diene unit 3 does not contain the conjugated diene unit 1.

[0019] (Aromatic vinyl repeating unit) The hydrogenated conjugated diene rubber preferably further contains a repeating unit based on an aromatic vinyl. Examples of aromatic vinyls include styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-ethylstyrene, 3-ethylstyrene, 4-ethylstyrene, 2,4-diisopropylstyrene, 2,4-dimethylstyrene, 4-t-butylstyrene, 5-t-butyl-2-methylstyrene, vinylnaphthalene, dimethylaminomethylstyrene, and dimethylaminoethylstyrene. Among these, at least one selected from the group consisting of styrene, α-methylstyrene, and 4-methylstyrene is preferred, and styrene is more preferred.

[0020] (Total amount of conjugated diene unit 1 and hydrogenated conjugated diene unit 3) The total proportion of the conjugated diene unit 1 and the hydrogenated conjugated diene unit 3 in the hydrogenated conjugated diene rubber may be more than 0 mass % and 100 mass % or less based on the total amount of the hydrogenated conjugated diene rubber. The ratio of the total amount of the conjugated diene unit 1 and the hydrogenated conjugated diene unit 3 in the hydrogenated conjugated diene rubber is not particularly limited, but is preferably 5 to 95 mass%, more preferably 8 to 93 mass%. Note that the above range can be the ratio of the total amount of the conjugated diene unit 1 and the hydrogenated conjugated diene unit 3 in the hydrogenated conjugated diene rubber in the case where the hydrogenated conjugated diene rubber further has a repeating unit of aromatic vinyl.

[0021] (Content of aromatic vinyl repeating units) When the hydrogenated conjugated diene rubber further has a repeating unit of aromatic vinyl, the content of the repeating unit of aromatic vinyl is not particularly limited, but is preferably 5 to 95 mass%, more preferably 7 to 92 mass%, of the total amount of the hydrogenated conjugated diene rubber. In addition, when the hydrogenated conjugated diene rubber further has a repeating unit based on aromatic vinyl, from the viewpoint of being able to introduce a large amount of repeating units based on aromatic vinyl into the obtained modified hydrogenated conjugated diene rubber, the content ratio of the repeating units based on aromatic vinyl in the hydrogenated conjugated diene rubber is preferably 10 to 40 mass% of the total amount of the hydrogenated conjugated diene rubber. In addition, when the hydrogenated conjugated diene rubber further has a repeating unit based on aromatic vinyl, the proportion of the total amount of the conjugated diene unit 1 and the hydrogenated conjugated diene unit 3 in the hydrogenated conjugated diene rubber can be set to a range or value obtained by excluding the proportion of the content of the repeating unit based on aromatic vinyl in the hydrogenated conjugated diene rubber from the total amount of the hydrogenated conjugated diene rubber.

[0022] Examples of the hydrogenated conjugated diene rubber include hydrogenated conjugated diene-aromatic vinyl copolymers such as hydrogenated polybutadiene, hydrogenated polychloroprene, and hydrogenated styrene-butadiene copolymers (hydrogenated SBR).

[0023] (Microstructure of Hydrogenated Conjugated Diene Rubber) (1) Content of repeating units formed by conjugated dienes and having vinylene groups In the hydrogenated conjugated diene rubber, the conjugated diene unit 1 may have a repeating unit formed by a conjugated diene and having a vinylene group. The content of the repeating unit formed by a conjugated diene and having a vinylene group in the conjugated diene unit 1 may be, for example, 90 mass% or less, and preferably more than 0 and 30 mass%, of the total amount of the conjugated diene unit 1 and the hydrogenated conjugated diene unit 3. (2) Content of repeating units formed by conjugated dienes and having vinyl groups In the hydrogenated conjugated diene rubber, the conjugated diene unit 1 is formed by a conjugated diene and may or may not have a repeating unit having a vinyl group.

[0024] (3) Content of repeating units formed from conjugated dienes and having hydrogenated vinylene groups In the hydrogenated conjugated diene rubber, the hydrogenated conjugated diene unit 3 may have a repeating unit formed by a conjugated diene and having a hydrogenated vinylene group (the vinylene group is hydrogenated). The content of the repeating unit formed by a conjugated diene and having a hydrogenated vinylene group in the conjugated diene unit 3 may be, for example, 10 to 90 mass% of the total amount of the conjugated diene unit 1 and the hydrogenated conjugated diene unit 3. (4) Content of repeating units formed from conjugated dienes and having hydrogenated vinyl groups The hydrogenated conjugated diene unit 3 may have a repeating unit formed from a conjugated diene and having a hydrogenated vinyl group (the vinyl group is hydrogenated). The content of the repeating unit formed from a conjugated diene and having a hydrogenated vinyl group (the vinyl group is hydrogenated) in the hydrogenated conjugated diene unit 3 may be, for example, 30 to 50 mass % in the total amount of the conjugated diene unit 1 and the hydrogenated conjugated diene unit 3. In this specification, the microstructure is 1 The compound was analyzed by 1 H-NMR analysis (solvent: deuterated chloroform) and IR analysis. Furthermore, in the above microstructure, the contents of the above (1) to (4) can be combined so that the total of the contents of the above (1) to (4) is 100% by mass. The total of the contents of the above (1) to (2) may be within the range of the content of the conjugated diene unit 1 described below. The total of the contents of the above (3) to (4) may be within the range of the content of the hydrogenated conjugated diene unit 3. The range of the content of the hydrogenated conjugated diene unit 3 may be the remainder obtained by excluding the range of the content of the conjugated diene unit 1 described below from the total of the conjugated diene unit 1 and the hydrogenated conjugated diene unit 3, which is 100% by mass.

[0025] [Content of conjugated diene unit 1] In the present invention, the content of the conjugated diene unit 1 in the hydrogenated conjugated diene rubber is 90 mass % or less based on the total amount of the conjugated diene unit 1 and the hydrogenated conjugated diene unit 3. The lower limit of the content of the conjugated diene unit 1 may be more than 0 mass % of the above total amount.

[0026] The content of the conjugated diene unit 1 is preferably 5 to 50 mass %, more preferably 8 to 30 mass %, of the total amount of the conjugated diene unit 1 and the hydrogenated conjugated diene unit 3, from the viewpoint of achieving the effects of the present invention (ease of vulcanization; the same applies below) and facilitating the metathesis reaction.

[0027] Generally, in a conjugated diene rubber, the vinyl group is more easily hydrogenated than the vinylene group, which is contained in the repeating unit constituting the rubber. Therefore, in the present invention, when the content of the conjugated diene unit 1 is 30% by mass or less in the total amount of the conjugated diene unit 1 and the hydrogenated conjugated diene unit 3 (i.e., when the hydrogenation rate in the total amount of the repeating units of the conjugated diene is 30% or less), the amount of the repeating units having a vinyl group in the total amount of the repeating units of the conjugated diene is considered to be approximately zero% by mass.

[0028] (Weight average molecular weight and molecular weight distribution of hydrogenated conjugated diene rubber) The weight average molecular weight of the hydrogenated conjugated diene rubber is preferably from 10,000 to 2,000,000 (g / mol), and more preferably from 50,000 to 1,500,000 (g / mol). The molecular weight distribution of the hydrogenated conjugated diene rubber is preferably 1.0 to 2.0. In this specification, the number average molecular weight (Mn), weight average molecular weight (Mw), and molecular weight distribution (Mw / Mn) are values ​​calculated as standard polystyrene by gel permeation chromatography (GPC) measurement under the following conditions. Solvent: Tetrahydrofuran Detector: RI detector

[0029] (Glass transition temperature of hydrogenated conjugated diene rubber) The glass transition temperature (Tg) of the hydrogenated conjugated diene rubber is preferably from -100 to 0°C. In this specification, the glass transition temperature (Tg) is measured using a differential scanning calorimeter (DSC) at a temperature rise rate of 20° C. / min and calculated by the midpoint method.

[0030] (Method for preparing hydrogenated conjugated diene rubber) The method for preparing the hydrogenated conjugated diene rubber is not particularly limited. For example, a method can be mentioned in which styrene and butadiene are charged in a nitrogen-substituted reactor, and an organic lithium such as n-butyl lithium is added under the condition of 0 to 60°C to polymerize styrene and butadiene to prepare a conjugated diene rubber (for example, the above-mentioned styrene butadiene rubber) (polymerization step), and then the above-mentioned conjugated diene rubber is hydrogenated in the presence of a catalyst such as titanocene dichloride (hydrogenation step) to prepare a hydrogenated conjugated diene rubber (for example, the above-mentioned hydrogenated SBR). In this specification, when an aromatic vinyl such as styrene is further used as a monomer in the polymerization step, the repeating units of the aromatic vinyl contained in the conjugated diene rubber used in the hydrogenation step are not hydrogenated in the hydrogenation step.

[0031] [Conjugated diene rubber] The conjugated diene rubber used in the production method of the present invention is a conjugated diene rubber containing a repeating unit having a carbon-carbon double bond. The repeating unit having a carbon-carbon double bond is a repeating unit constituted by a conjugated diene. The conjugated diene rubber does not include the above-mentioned hydrogenated conjugated diene rubber.

[0032] The conjugated diene as a monomer capable of forming the conjugated diene rubber is not particularly limited. For example, butadiene (e.g., 1,3-butadiene), chloroprene, etc. are included. Among them, the conjugated diene preferably contains 1,3-butadiene. The monomers forming the conjugated diene rubber preferably contain a conjugated diene in a proportion of 90 to 100 mol %, and more preferably 100 mol %, of the total amount of monomers. Examples of conjugated diene rubbers include polybutadiene (BR) and polychloroprene.

[0033] The repeating unit of the conjugated diene rubber may have, for example, a vinyl group (e.g., a vinyl group in a 1,2-vinyl bond when the conjugated diene is 1,3-butadiene) or a vinylene group (e.g., a vinylene group in a 1,4-bond when the conjugated diene is 1,3-butadiene) as the carbon-carbon double bond. The conjugated diene rubber preferably has a repeating unit having a bond containing a vinyl group (for example, a 1,2-vinyl bond when the conjugated diene is 1,3-butadiene) and a repeating unit having a bond containing a vinylene group (for example, a 1,4-bond when the conjugated diene is 1,3-butadiene). The content of the repeating units having a bond containing a vinylene group in all repeating units constituting the conjugated diene rubber is preferably 30 to 60 mass % from the viewpoint of achieving superior effects of the present invention. The content of the repeating units having a bond containing a vinyl group in all repeating units constituting the conjugated diene rubber is preferably 40 to 70 mass % from the viewpoint of achieving superior effects of the present invention.

[0034] (Weight average molecular weight and molecular weight distribution of conjugated diene rubber) From the viewpoint of obtaining superior effects of the present invention, the weight average molecular weight of the conjugated diene rubber is preferably 10,000 to 2,000,000 (g / mol; the same applies below), more preferably 50,000 to 1,500,000, and even more preferably 100,000 to 1,000,000. From the viewpoint of obtaining superior effects of the present invention, a preferred embodiment of the conjugated diene rubber is liquid at 25°C. The molecular weight distribution of the conjugated diene rubber is preferably 1.0 to 2.0, from the viewpoint of obtaining superior effects of the present invention.

[0035] (Method for preparing conjugated diene rubber) An example of a method for preparing a conjugated diene rubber is a method for preparing a conjugated diene rubber by anionically polymerizing a conjugated diene such as 1,3-butadiene in the presence of an organolithium compound such as n-butyllithium at 0 to 50°C. Conjugated diene rubbers prepared by anionic polymerization are preferred because the content ratio of repeating units having bonds containing vinylene groups and the content ratio of repeating units having bonds containing vinyl groups can each be set within an appropriate range.

[0036] (Amount of conjugated diene rubber used) From the viewpoint of obtaining superior effects of the present invention, the amount of the conjugated diene rubber used is preferably 1 to 30 parts by mass, and more preferably 5 to 20 parts by mass, per 100 parts by mass of the hydrogenated conjugated diene rubber.

[0037] [Metathesis catalyst] The metathesis catalyst used in the production method of the present invention is not particularly limited. For example, Grubbs catalyst (first generation), Grubbs catalyst (second generation), Grubbs catalyst (third generation), Schrock catalyst, and Hoveyda-Grubbs catalyst can be mentioned. From the viewpoint of achieving superior effects of the present invention, the metathesis catalyst preferably contains a catalyst known as a Grubbs catalyst (second generation) (structure shown below).

[0038] [ka]

[0039] (Metathesis catalyst amount used) The amount of the metathesis catalyst used is preferably 0.1 to 10 parts by mass, and more preferably 0.5 to 5.0 parts by mass, based on 100 parts by mass of the hydrogenated conjugated diene rubber, from the viewpoint of obtaining superior effects of the present invention.

[0040] (Reaction process) In the reaction step of reacting the hydrogenated conjugated diene rubber with the conjugated diene rubber in the presence of a metathesis catalyst, for example, a solvent may be used as necessary. Examples of the solvent include tetrahydrofuran (THF), toluene, and alkyl solvents such as hexane and cyclohexane. When a solvent is used in the reaction step, the amount of the solvent used can be, for example, 500 to 2000 mL per 100 g of the hydrogenated conjugated diene rubber. The above reaction is preferably carried out with stirring. The reaction time in the reaction step can be, for example, 1 to 24 hours. The temperature condition in the reaction step can be, for example, 0 to 40°C. After the reaction, a reaction terminator such as ethyl vinyl ether is added to the reaction system to terminate the metathesis reaction, thereby obtaining a modified hydrogenated conjugated diene rubber. The modified hydrogenated conjugated diene rubber produced by the production method of the present invention may contain unreacted hydrogenated conjugated diene rubber and / or conjugated diene rubber, as well as by-products (for example, products of metathesis reaction between hydrogenated conjugated diene rubbers or between conjugated diene rubbers). After the reaction, for example, the reaction solution may be filtered through a filter, and the filtrate may be added to alcohol to purify the alcohol-insoluble components, thereby purifying the modified hydrogenated conjugated diene rubber. The refined modified hydrogenated conjugated diene rubber may contain, for example, unreacted hydrogenated conjugated diene rubber as an impurity.

[0041] The modified hydrogenated conjugated diene rubber produced as described above is not particularly limited as long as it is a polymer formed by combining the above-mentioned hydrogenated conjugated diene rubber, which is a raw material, and the above-mentioned conjugated diene rubber. For example, hydrogenated SBR as the hydrogenated conjugated diene rubber and polybutadiene as the conjugated diene rubber are reacted to produce hydrogenated SBR modified by polybutadiene as the modified hydrogenated conjugated diene rubber.

[0042] (Weight average molecular weight of modified hydrogenated conjugated diene rubber) From the viewpoint of obtaining superior effects of the present invention, the weight average molecular weight of the modified hydrogenated conjugated diene rubber produced as described above is preferably 10,000 (g / mol; units will be omitted below) or more, more preferably 100,000 to 1,000,000, and even more preferably 300,000 to 500,000. The weight average molecular weight of the modified hydrogenated conjugated diene rubber produced as described above is preferably from 200,000 to 1,000,000 in view of its high molecular weight.

[0043] (Molecular weight distribution of modified hydrogenated conjugated diene rubber) From the viewpoint of obtaining superior effects of the present invention, the molecular weight distribution (Mw / Mn) of the modified hydrogenated conjugated diene rubber produced as described above is preferably 1.0 to 4.0, and more preferably 1.0 to 3.0.

[0044] (Conjugated diene unit 2 and hydrogenated conjugated diene unit 4) The modified hydrogenated conjugated diene rubber preferably has the conjugated diene unit 2 and the hydrogenated conjugated diene unit 4 . At least a part of the conjugated diene unit 2 can be derived from the above-mentioned raw material conjugated diene rubber and introduced into the modified hydrogenated conjugated diene rubber by a metathesis reaction. The conjugated diene unit 2 may include a part derived from the conjugated diene unit 1 contained in the above-mentioned raw material hydrogenated conjugated diene rubber. Therefore, the conjugated diene unit 2 can have a repeating unit formed by a conjugated diene and having a vinylene group, and / or a repeating unit formed by a conjugated diene and having a vinyl group. The hydrogenated conjugated diene units 4 can be derived from the hydrogenated conjugated diene rubber as a raw material and introduced into the modified hydrogenated conjugated diene rubber by a metathesis reaction. Therefore, the hydrogenated conjugated diene unit 4 can have a repeating unit formed by a conjugated diene and having a hydrogenated vinylene group, and / or a repeating unit formed by a conjugated diene and having a hydrogenated vinyl group.

[0045] (Content of conjugated diene unit 2) From the viewpoint of achieving superior effects of the present invention, the modified hydrogenated conjugated diene rubber has conjugated diene units 2 and hydrogenated conjugated diene units 4, and the content of the conjugated diene units 2 is preferably 30 mass% or more, more preferably 30 to 70 mass%, and even more preferably more than 30 mass% but not more than 50 mass% of the total amount of the conjugated diene units 2 and the hydrogenated conjugated diene units 4. The content of the conjugated diene unit 2 in the total amount of the conjugated diene unit 2 and the hydrogenated conjugated diene unit 4 in the modified hydrogenated conjugated diene rubber is preferably higher than the content of the conjugated diene unit 1 in the total amount of the conjugated diene unit 1 and the hydrogenated conjugated diene unit 3 in the hydrogenated conjugated diene rubber as a raw material. For example, the content of the conjugated diene unit 2 can be higher than the content of the conjugated diene unit 1 by, for example, 10 to 40% by mass.

[0046] (Content of Repeating Units Having Vinylene Group) The content of the repeating unit having a vinylene group in the conjugated diene unit 2 of the modified hydrogenated conjugated diene rubber (for example, the amount of 1,4-bonds when the conjugated diene is butadiene) is preferably 10 to 90 mass %, more preferably 15 to 30 mass %, of the total amount of the conjugated diene unit 2 and the hydrogenated conjugated diene unit 4, from the viewpoint of obtaining superior effects of the present invention. In addition, one preferred embodiment is one in which the content of the repeating unit having a vinylene group in the conjugated diene unit 2 in the total amount of the conjugated diene unit 2 and the hydrogenated conjugated diene unit 4 is greater than the content of the repeating unit having a vinylene group in the conjugated diene unit 1 in the total amount of the conjugated diene unit 1 and the hydrogenated conjugated diene unit 3.

[0047] (Content of repeating units having vinyl groups) From the viewpoint of obtaining superior effects of the present invention, the content of repeating units having a vinyl group in the conjugated diene units 2 of the modified hydrogenated conjugated diene rubber (for example, the vinyl amount (Vn amount) when the conjugated diene is butadiene) is preferably 5 to 80 mass %, more preferably 10 to 20 mass %, and further preferably 13 to 17 mass % of the total amount of the conjugated diene units 2 and the hydrogenated conjugated diene units 4. In addition, one preferred embodiment is one in which the content of the repeating unit having a vinyl group in the conjugated diene unit 2 in the total amount of the conjugated diene unit 2 and the hydrogenated conjugated diene unit 4 is greater than the content of the repeating unit having a vinyl group in the conjugated diene unit 1 in the total amount of the conjugated diene unit 1 and the hydrogenated conjugated diene unit 3.

[0048] (Hydrogenated conjugated diene unit 4 content) From the viewpoint of obtaining superior effects of the present invention, the content of the hydrogenated conjugated diene units 4 in the modified hydrogenated conjugated diene rubber is preferably 70 mass% or less, more preferably 30 to 70 mass%, and even more preferably 50 to 70 mass%, of the total amount of the conjugated diene units 2 and the hydrogenated conjugated diene units 4.

[0049] (Aromatic vinyl repeating unit) The modified hydrogenated conjugated diene rubber preferably further contains a repeating unit of aromatic vinyl. Examples of aromatic vinyls include styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-ethylstyrene, 3-ethylstyrene, 4-ethylstyrene, 2,4-diisopropylstyrene, 2,4-dimethylstyrene, 4-t-butylstyrene, 5-t-butyl-2-methylstyrene, vinylnaphthalene, dimethylaminomethylstyrene, and dimethylaminoethylstyrene. Among these, at least one selected from the group consisting of styrene, α-methylstyrene, and 4-methylstyrene is preferred, and styrene is more preferred. In the case where the modified hydrogenated conjugated diene rubber further contains an aromatic vinyl repeating unit, a preferred embodiment of the aromatic vinyl repeating unit is derived from an aromatic vinyl repeating unit that the hydrogenated conjugated diene rubber can further have.

[0050] (Total amount of conjugated diene unit 2 and hydrogenated conjugated diene unit 4) The total proportion of the conjugated diene units 2 and the hydrogenated conjugated diene units 4 in the modified hydrogenated conjugated diene rubber may be more than 0 mass % and 100 mass % or less in the total amount of the modified hydrogenated conjugated diene rubber. When the modified hydrogenated conjugated diene rubber further has a repeating unit of aromatic vinyl, the proportion of the total amount of the conjugated diene units 2 and the hydrogenated conjugated diene units 4 in the modified hydrogenated conjugated diene rubber is preferably 5 to 97 mass%, and more preferably more than 90 mass% and 97 mass%, from the viewpoint of obtaining better effects of the present invention. When the modified hydrogenated conjugated diene rubber further has a repeating unit based on aromatic vinyl, the total amount of the conjugated diene units 2 and the hydrogenated conjugated diene units 4 in the modified hydrogenated conjugated diene rubber is preferably 70 to 90 mass%, more preferably 70 to 80 mass%, from the viewpoint of increasing the content of the repeating unit based on aromatic vinyl.

[0051] (Content of aromatic vinyl repeating units) When the modified hydrogenated conjugated diene rubber further has a repeating unit of aromatic vinyl, the content ratio of the repeating unit of aromatic vinyl in all repeating units constituting the modified hydrogenated conjugated diene rubber is preferably 3 to 95 mass%, and more preferably 3 mass% or more and less than 10 mass%, from the viewpoint of obtaining better effects of the present invention. When the modified hydrogenated conjugated diene rubber further has a repeating unit of aromatic vinyl, the content ratio of the repeating unit of aromatic vinyl in all repeating units constituting the modified hydrogenated conjugated diene rubber is preferably 10 to 30 mass%, and more preferably 20 to 30 mass%, from the viewpoint of a high content ratio of the repeating unit of aromatic vinyl. In addition, when the modified hydrogenated conjugated diene rubber further has a repeating unit based on aromatic vinyl, the proportion of the total amount of the conjugated diene unit 2 and the hydrogenated conjugated diene unit 4 in the modified hydrogenated conjugated diene rubber can be a value or range obtained by excluding the proportion of the content of the repeating unit based on aromatic vinyl in the modified hydrogenated conjugated diene rubber from the total repeating units constituting the modified hydrogenated conjugated diene rubber.

[0052] [Modified hydrogenated conjugated diene rubber] The modified hydrogenated conjugated diene rubber of the present invention is a modified hydrogenated conjugated diene rubber produced by the method for producing a modified hydrogenated conjugated diene rubber of the present invention. Details of the modified hydrogenated conjugated diene rubber of the present invention are as described above in the production method of the modified hydrogenated conjugated diene rubber of the present invention.

[0053] [Rubber composition] The rubber composition of the present invention is a rubber composition containing the modified hydrogenated conjugated diene rubber of the present invention and sulfur. The modified hydrogenated conjugated diene rubber contained in the rubber composition of the present invention may be any modified hydrogenated conjugated diene rubber of the present invention. The sulfur contained in the rubber composition of the present invention is not particularly limited, and examples thereof include those conventionally known. The content of sulfur is preferably 0.5 to 10 parts by mass based on 100 parts by mass of the modified hydrogenated conjugated diene rubber.

[0054] The rubber composition of the present invention may further contain additives. Examples of the additives include various additives that are generally used in rubber compositions, such as white fillers such as silica, carbon black, silane coupling agents, zinc oxide (zinc white), stearic acid, resins, antioxidants, waxes, processing aids, oils, liquid polymers, terpene resins, thermosetting resins, and vulcanization accelerators. The rubber composition of the present invention may further contain a rubber component other than the modified hydrogenated conjugated diene rubber of the present invention. Examples of such a rubber component include natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene butadiene rubber (SBR), acrylonitrile-butadiene copolymer rubber (NBR), butyl rubber (IIR), halogenated butyl rubber (Br-IIR, Cl-IIR), chloroprene rubber (CR), etc.

[0055] (Carbon black and / or silica) In one preferred embodiment, the rubber composition of the present invention further contains carbon black and / or silica. The carbon black is not particularly limited, and any conventionally known carbon black can be used. Examples of the carbon black include SAF-HS, SAF, ISAF-HS, ISAF, ISAF-LS, IISAF-HS, HAF-HS, HAF, HAF-LS, FEF, GPF, and SRF carbon black. The silica is not particularly limited, and any conventionally known silica can be used. Examples of the silica include wet silica, dry silica, fumed silica, and diatomaceous earth.

[0056] (Carbon black and / or silica content) From the viewpoint of obtaining superior effects of the present invention, the content of the carbon black and / or the silica is preferably 30 to 100 parts by mass relative to 100 parts by mass of the modified hydrogenated conjugated diene rubber. When the rubber composition of the present invention contains carbon black and silica, the total content of the carbon black and the silica may be within the above range relative to 100 parts by mass of the modified hydrogenated conjugated diene rubber.

[0057] (Silane coupling agent) In one preferred embodiment, the rubber composition of the present invention further contains a silane coupling agent. The silane coupling agent is a compound having a hydrolyzable silyl group and a functional group. The functional group is preferably a vinyl group or a functional group capable of reacting with a group having a vinyl group. Examples of the functional group include an epoxy group, a vinyl group, an acryloyl group, a methacryloyl group, an amino group, a sulfide group, a mercapto group, and a blocked mercapto group (protected mercapto group) (e.g., an octanoylthio group). The functional group is preferably a functional group having sulfur, and more preferably a mercapto group, a sulfide group (including a monosulfide group and a polysulfide group), or a blocked mercapto group. The hydrolyzable silyl group contained in the silane coupling agent is not particularly limited. In the silane coupling agent, the hydrolyzable silyl group and the functional group can be bonded directly or via a linking group, which is not particularly limited.

[0058] Specific examples of the silane coupling agent include bis(3-triethoxysilylpropyl)tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(3-triethoxysilylpropyl)disulfide, mercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane, 3-trimethoxysilylpropyl-N,N-dimethylthiocarbamoyl-tetrasulfide, trimethoxysilylpropyl-mercaptobenzothiazole tetrasulfide, triethoxysilylpropyl-methacrylate-monosulfide, dimethoxymethylsilylpropyl-N,N-dimethylthiocarbamoyl-tetrasulfide, and 3-octanoylthio-1-propyltriethoxysilane.

[0059] (Silane coupling agent content) In the rubber composition of the present invention, the content of the silane coupling agent is not particularly limited, but is preferably 30 parts by mass or less, and more preferably 1 to 25 parts by mass, per 100 parts by mass of the above-mentioned modified hydrogenated conjugated diene rubber.

[0060] (Method of manufacturing rubber composition) The method for producing the rubber composition of the present invention is not particularly limited, and specific examples thereof include a method of mixing the above-mentioned components using a known method or device (e.g., a Banbury mixer, a kneader, a roll, etc.) When the rubber composition of the present invention further contains a vulcanization accelerator, it is preferable to first mix the components other than sulfur and the vulcanization accelerator at a high temperature (preferably 100 to 160°C), cool the mixture, and then mix the sulfur or the vulcanization accelerator. The rubber composition of the present invention can be vulcanized or crosslinked under conventionally known vulcanization or crosslinking conditions.

[0061] (Application) The rubber composition of the present invention can be suitably used for, for example, tires, conveyor belts, hoses, vibration-proof materials, rubber rolls, outer covers of railway cars, and the like.

[0062] [tire] The tire of the present invention is a tire manufactured using the above-mentioned rubber composition of the present invention. FIG. 1 shows a partial cross-sectional schematic view of a tire representing one example of an embodiment of a tire of the present invention, but the tire of the present invention is not limited to the embodiment shown in FIG.

[0063] In FIG. 1, the tire has a bead portion 1 , a sidewall portion 2 , and a tire tread portion 3 . Between the pair of left and right bead portions 1, a carcass layer 4 having fiber cords embedded therein is installed, and the ends of the carcass layer 4 are folded back and wrapped around the bead cores 5 and bead fillers 6 from the inside to the outside of the tire. In the tire tread portion 3, a belt layer 7 is disposed on the outer side of the carcass layer 4 over one circumference of the tire. In addition, a rim cushion 8 is disposed in the bead portion 1 at a portion that comes into contact with the rim.

[0064] There is no particular limitation on which component part of the tire of the present invention the rubber composition of the present invention is applied to, but one preferred embodiment is to apply the rubber composition of the present invention to the tire tread portion of the tire of the present invention.

[0065] The tire of the present invention can be manufactured, for example, according to a conventionally known method. The gas that can be filled into the tire of the present invention can be, for example, normal air or air with an adjusted oxygen partial pressure, or an inert gas such as nitrogen, argon, or helium. EXAMPLES

[0066] The present invention will be described in further detail below with reference to examples. The materials, amounts, ratios, processing contents, processing procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited by the following examples.

[0067] [Production of modified hydrogenated conjugated diene rubber] First, details of hydrogenated SBR1 or 2 used as a raw material in [Production of modified hydrogenated conjugated diene rubber] are shown in Table 1 below.

[0068] [Table 1]

[0069] Next, details of BR1 or BR2 used as a raw material in [Production of modified hydrogenated conjugated diene rubber] are shown in Table 2 below. [Table 2]

[0070] (Reaction between hydrogenated conjugated diene rubber and conjugated diene rubber) Hydrogenated SBR1 or 2 (10 g) in Table 1 above was dissolved in THF (tetrahydrofuran, 100 mL), and a solution of Grubbs catalyst (second generation) (manufactured by Aldrich, 0.1 g) in THF (10 mL) was added at room temperature and stirred. THF (10 mL) of BR1 or 2 (1 g) in Table 2 above, which was synthesized by anionic polymerization of 1,3-butadiene, was added dropwise to the solution and stirred at room temperature for 5 hours. Then, ethyl vinyl ether (1 mL) was added to the reaction system under room temperature conditions and stirred for 6 hours to stop the reaction. The solution was filtered through a stainless steel filter to remove the gel component, and then added dropwise to methanol (500 mL) to separate it into methanol-insoluble and methanol-soluble components. The methanol-insoluble component was dissolved again in THF (20 mL) and added dropwise to methanol (500 mL) to obtain modified hydrogenated SBR1 to 4 as modified hydrogenated conjugated diene rubbers. The amounts of the respective raw materials used in the production of the above modified hydrogenated conjugated diene rubber are summarized in Table 3 below. Table 3 also shows the St amount, the total amount of the conjugated diene unit 2 and the hydrogenated conjugated diene unit 4, the content of the conjugated diene unit 2, the Vn amount, the 1,4-bond amount, the hydrogenated conjugated diene unit 4 amount, the hydrogenated Vn amount, the hydrogenated 1,4-bond amount, the weight average molecular weight (Mw), the molecular weight distribution (Mw / Mn), and the yield of the modified hydrogenated conjugated diene rubber produced in each Example.

[0071] [Table 3]

[0072] [Preparation of Rubber Composition] The components shown in Table 4 below were mixed in the ratios (parts by mass) shown in the same table. Specifically, first, the components shown in Table 4 below, except for sulfur and the vulcanization accelerator, were mixed for 5 minutes in a Banbury mixer at 80° C. Next, the sulfur and the vulcanization accelerator were mixed using a roll to obtain each rubber composition.

[0073] [Evaluation: Ease of vulcanization] The viscosity of each rubber composition obtained was compared before and after heating to evaluate the ease of vulcanization of the rubber composition (and thus the modified hydrogenated conjugated diene rubber). The results are shown in Table 4. 1 g of each of the rubber compositions prepared as above was applied to a spindle viscometer, and the spindle was rotated at a rotation speed of 2 rpm for 10 revolutions at 25° C. to measure the viscosity of the rubber composition before heating. 1 g of each of the rubber compositions prepared as described above was applied to a spindle viscometer, heated for 20 minutes at 150°C, and rotated the spindle 5 times at a rotation speed of 2 revolutions / min to measure the viscosity of the rubber composition after heating. For each rubber composition, the viscosity before heating was set to 100, and the viscosity value after heating was divided by the viscosity value before heating to obtain an index. In the present invention, the rubber was evaluated as being easily vulcanized when the index was equal to or greater than 200. The larger the index is above 200, the easier the rubber is to vulcanize. When the index was less than 200, the rubber was evaluated as being difficult to vulcanize.

[0074] [Table 4]

[0075] Details of each component shown in Table 4 are as follows. Hydrogenated SBR1: This is the same as the hydrogenated SBR1 used as the raw material in the above-mentioned [Production of modified hydrogenated conjugated diene rubber]. Hydrogenated SBR2: This is the same as the hydrogenated SBR2 used as the raw material in the above-mentioned [Production of modified hydrogenated conjugated diene rubber]. Modified hydrogenated SBR1 to 4: The same as the modified hydrogenated SBR1 to 4 produced in the above-mentioned [Production of modified hydrogenated conjugated diene rubber].

[0076] Zinc oxide: Three types of zinc oxide manufactured by Seido Chemical Industry Co., Ltd. Stearic acid: Lunac S-25 (Kao) Sulfur: Akzo Nobel Krystex HS OT 20 Vulcanization accelerator CBBS: Noccela CZ, manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

[0077] From the results in Table 4, it was confirmed that the rubber composition of the present invention containing the modified hydrogenated conjugated diene rubber of the present invention was easily vulcanized. In addition, it is generally considered that, between 1,2-vinyl bonds and 1,4-bonds in butadiene rubber, 1,4-bonds are more likely to contribute to vulcanization. With this in mind, referring to Table 4, the results in Table 4 are considered to indicate that the repeating units having a vinylene group derived from the raw material conjugated diene rubber are introduced into the raw material hydrogenated conjugated diene rubber by the metathesis reaction, and the content of the repeating units having a vinylene group in the modified hydrogenated conjugated diene rubber of the present invention is increased compared to the content of the repeating units having a vinylene group in the raw material hydrogenated conjugated diene rubber. On the other hand, Comparative Examples 1 and 2, which did not contain the modified hydrogenated conjugated diene rubber of the present invention but contained unmodified hydrogenated SBR instead, were difficult to vulcanize.

[0078] (Reactivity of modified hydrogenated conjugated diene rubber with silane coupling agents) The reactivity of the modified hydrogenated conjugated diene rubber with the silane coupling agent was evaluated by the following method. Each of the modified hydrogenated SBRs 1 to 4 (5 g) or hydrogenated SBRs 1 and 2 (5 g) produced as described above was reacted with mercaptopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., 1 g) at 150° C. with stirring. Table 5 shows the yield after the reaction, the weight average molecular weight (Mw), the molecular weight distribution (Mw / Mn) and the reaction rate of the reaction product obtained by the reaction. The reaction rate of modified hydrogenated SBR1-4 before and after the reaction is 1 H-NMR was measured before and after the reaction. 1 It was calculated from the integral value of the 1,4-bond peak (1,4-cis bond: 5.3 ppm, and 1,4-trans bond: 5.35 ppm) and the peak (δ: 0.6 ppm) assigned to the proton of the methylene group adjacent to the silicon atom in H-NMR.

[0079] From the results in Table 5, it was confirmed that the modified hydrogenated conjugated diene rubber of the present invention reacted with the compound having a mercapto group (silane coupling agent). In general, it is considered that, between 1,2-vinyl bonds and 1,4-bonds in butadiene rubber, 1,2-vinyl bonds are more likely to react with compounds having a mercapto group. With reference to Table 5 based on this, the results in Table 5 are considered to indicate that repeating units having vinyl groups derived from the raw material conjugated diene rubber are introduced into the modified hydrogenated conjugated diene rubber of the present invention by the metathesis reaction. On the other hand, in Comparative Examples 3 and 4, which did not use the modified hydrogenated conjugated diene rubber of the present invention, but instead used unmodified hydrogenated SBR1 and 2 that did not have vinyl groups, the reaction rate was low and there was almost no reaction with the compound having a mercapto group.

[0080] [Table 5] [Explanation of symbols]

[0081] 1 Bead section 2 Sidewall 3 Tire tread 4 Carcass layer 5 Bead Core 6 Bead Filler 7 Belt layer 8 Rim cushion

Claims

1. A method for producing a modified hydrogenated conjugated diene rubber, comprising reacting a hydrogenated conjugated diene rubber having a repeating unit having a carbon-carbon double bond and a hydrogenated conjugated diene unit 3, the content of which is 90 mass% or less of a total amount of the conjugated diene unit 1 and the hydrogenated conjugated diene unit 3, with a conjugated diene rubber having a repeating unit having a carbon-carbon double bond, in the presence of a metathesis catalyst, to produce a modified hydrogenated conjugated diene rubber.

2. The method for producing a modified hydrogenated conjugated diene rubber according to claim 1, wherein a content of the first conjugated diene unit is 10 to 90 mass% of a total amount of the first conjugated diene unit and the third hydrogenated conjugated diene unit.

3. The method for producing a modified hydrogenated conjugated diene rubber according to claim 1, wherein the weight average molecular weight of the conjugated diene rubber is from 10,000 to 2,000,000.

4. A modified hydrogenated conjugated diene rubber produced by the method for producing a modified hydrogenated conjugated diene rubber according to any one of claims 1 to 3.

5. The modified hydrogenated conjugated diene rubber according to claim 4, wherein the weight average molecular weight of the modified hydrogenated conjugated diene rubber is 10,000 or more.

6. The modified hydrogenated conjugated diene rubber according to claim 4, wherein the modified hydrogenated conjugated diene rubber has a conjugated diene unit 2 and a hydrogenated conjugated diene unit 4, and a content of the conjugated diene unit 2 is 30 mass% or more of a total amount of the conjugated diene unit 2 and the hydrogenated conjugated diene unit 4.

7. The modified hydrogenated conjugated diene rubber has a conjugated diene unit 2 and a hydrogenated conjugated diene unit 4, The modified hydrogenated conjugated diene rubber according to claim 4, wherein a content of a repeating unit having a vinylene group in the conjugated diene unit 2 is 10 to 90 mass% of a total amount of the conjugated diene unit 2 and the hydrogenated conjugated diene unit 4.

8. The modified hydrogenated conjugated diene rubber has a conjugated diene unit 2 and a hydrogenated conjugated diene unit 4, The modified hydrogenated conjugated diene rubber according to claim 4, wherein the content of the repeating unit having a vinyl group in the conjugated diene unit 2 is 10 to 80 mass% of the total amount of the conjugated diene unit 2 and the hydrogenated conjugated diene unit 4.

9. A rubber composition comprising the modified hydrogenated conjugated diene rubber according to claim 4 and sulfur.

10. A tire manufactured using the rubber composition according to claim 9.

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