Hydrogenated diene polymer, gum, rubber composition and tire

Abstract

Provided is a hydrogenated diene polymer in which the branching degree (Bn) obtained by GPC-light scattering measurement with a viscosity detector is 1.5 or greater, the composition ratio (mol%) of a structural unit represented by the following formula (1), a structural unit represented by the following formula (2), a structural unit represented by the following formula (3), and a structural unit represented by the following formula (4) is set to a, b, c, and d in this order, respectively, the following mathematical formula (S) is satisfied, and the hydrogenation rate is 40 to 85%. Mathematical formula (S): 10 ≦ [(a+b) / (a+b+c+d)] × 100 ≦ 70

Description

Technical Field

[0001] This invention relates to hydrogenated diene polymers, bales, rubber compositions, and tires. Background Technology

[0002] In recent years, the widespread adoption of all-season tires has rapidly increased, creating a strong demand for improved low-temperature performance of tires.

[0003] In the past, as a way to improve the low-temperature performance of tires, in order to reduce the elastic modulus at low temperatures and ensure the high traction of the tread rubber to the road surface at low temperatures, methods have been proposed such as adding rubber materials with low glass transition temperatures, such as high cis polybutadiene rubber or natural rubber, and adding oil as a plasticizer.

[0004] However, such a method has the problem of reducing the tensile strength of the rubber composition.

[0005] In view of this problem, as a method to improve the low-temperature performance of a rubber composition while maintaining its tensile strength, a method of adding liquid rubber as a plasticizer to the rubber composition has been proposed (see Patent Document 1). Liquid rubber has unsaturated bonds, which bond during vulcanization, thereby improving the tensile strength of the rubber composition.

[0006] However, by adding liquid rubber, the rubber composition suffers from reduced viscosity and decreased abrasion resistance.

[0007] In recent years, in the fields of tire treads, sheets, films, and rubber compositions for asphalt modification, a rubber composition comprising a rubber-like polymer having an ethylene structure and incorporating crosslinkable unsaturated groups has been proposed to improve mechanical strength and compression set. By containing such a rubber-like polymer, the tensile strength of the rubber composition is improved, and the wear resistance of the tire is also improved (see, for example, Patent Documents 1-5).

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 2008-50432

[0011] Patent Document 2: International Publication No. 2003 / 085010

[0012] Patent Document 3: International Publication No. 2019 / 151126

[0013] Patent Document 4: International Publication No. 2019 / 151127

[0014] Patent Document 5: International Publication No. 2019 / 078083 Summary of the Invention

[0015] The problem that the invention aims to solve

[0016] However, the previously proposed rubber-like polymers with ethylene structures and crosslinkable unsaturated groups have the following problems: they tend to have poor processability, which reduces the dispersibility of silica-based fillers in the rubber composition, thereby impairing the low oil consumption of the rubber composition.

[0017] Therefore, in view of the problems of the prior art, the object of the present invention is to provide a hydrogenated diene polymer for use in a rubber composition, which can be made into a vulcanizate with excellent low-temperature performance and abrasion resistance, and thus excellent fracture strength.

[0018] Methods for solving problems

[0019] In order to solve the problems of the prior art, the inventors conducted in-depth research and found that by setting the degree of branching of the hydrogenated diene polymer used in the rubber composition, the composition ratio of the polymer structural units, and the hydrogenation rate within a specific range, a rubber composition with excellent low-temperature performance and wear resistance and excellent fracture strength after being made into a sulfide can be obtained, thus completing the present invention.

[0020] That is, the present invention is as follows. [1]

[0022] A hydrogenated diene polymer, wherein,

[0023] The degree of branching (Bn) determined by GPC-light scattering with a viscosity detector is greater than 1.5.

[0024] When the composition ratios (mol%) of the structural units represented by equation (1), equation (2), equation (3), and equation (4) are respectively set as a, b, c, and d, the following mathematical expression (S) is satisfied.

[0025] The hydrogenation rate is 40-85%.

[0026] Mathematical expression (S): 10≦[(a+b) / (a+b+c+d)]×100≦70

[0027] [Chemistry 1]

[0028] 1) (2)

[0029] (3) (4) [2]

[0031] The hydrogenated diene polymer described above [1], wherein,

[0032] The degree of branching (Bn) determined by GPC-light scattering with a viscosity detector is greater than 1.5.

[0033] Satisfying the following mathematical expression (S),

[0034] The hydrogenation rate is 40-80%.

[0035] Mathematical expression (S): 10≦[(a+b) / (a+b+c+d)]×100≦60 [3]

[0037] The hydrogenated diene polymer as described in [1] or [2] above, wherein the following mathematical formula (X) is 2.0 or less.

[0038] Mathematical expression (X): (a+c) / (a+b) [4]

[0040] The hydrogenated diene polymer described above [3], wherein the mathematical formula (X) is 0.8 or more and 2.0 or less. [5]

[0042] The hydrogenated diene polymer as described in any one of [1] to [4] above, wherein the hydrogenation rate is 51% or more. [6]

[0044] The hydrogenated diene polymer as described in any one of [1] to [5] above, wherein the hydrogenation rate is 71% or less. [7]

[0046] The hydrogenated diene polymers described in any one of [1] to [6] above contain nitrogen atoms. [8]

[0048] The hydrogenated diene polymer as described in any one of [1] to [7] above, wherein the modification rate is 65% by mass or more. [9]

[0050] The hydrogenated diene polymer as described in any one of [1] to [8] above, wherein the aluminum content is less than 2 ppm.

[10]

[0052] A type of adhesive block, which is a molded body of the hydrogenated diene polymer described in any one of [1] to [9] above.

[11]

[0054] A rubber composition comprising:

[0055] 100 parts by weight of the rubber component, comprising 10 to 50 parts by weight of the hydrogenated diene polymer described in any one of [1] to [9] above, and 50 to 90 parts by weight of diene-based rubber, and

[0056] 20 to 100 parts by weight of silica-based inorganic filler.

[12]

[0058] The rubber composition described above

[11] contains 2 to 25 parts by mass of liquid rubber.

[13]

[0060] A tire, which is a molded body of the rubber composition described above

[12] .

[0061] The effects of the invention

[0062] According to the present invention, a hydrogenated diene polymer for use in a rubber composition is provided, the rubber composition being formulated into a vulcanizate with excellent low-temperature performance and abrasion resistance, and consequently excellent tensile strength. Detailed Implementation

[0063] The specific embodiments of the present invention (hereinafter referred to as "this embodiment") will be described in detail below.

[0064] It should be noted that the following embodiments are illustrative of the present invention, and the present invention is not limited to the following embodiments. The present invention can be suitably modified within the scope of its essential points.

[0065] [Hydrogenated diene polymer]

[0066] In the hydrogenated diene polymer of this embodiment, the degree of branching (Bn) determined by GPC-light scattering measurement with a viscosity detector is 1.5 or more; when the composition ratio (mol%) of the structural unit represented by the following formula (1), the structural unit represented by the following formula (2), the structural unit represented by the following formula (3), and the structural unit represented by the following formula (4) are set as a, b, c, and d respectively, the following mathematical formula (S) is satisfied; the hydrogenation rate is 40 to 85%.

[0067] Mathematical expression (S): 10≦[(a+b) / (a+b+c+d)]×100≦70

[0068] [Chemistry 2]

[0069] I) (2)

[0070] (3) (4)

[0071] The hydrogenated diene polymer of this embodiment uses conjugated diene monomer units and, if necessary, other monomer units as constituent monomer units.

[0072] The hydrogenated diene polymer of this embodiment is characterized by the fact that, as the monomer unit constituting the polymer, it does not substantially contain aromatic vinyl monomer units.

[0073] It should be noted that "substantially not containing" means that "aromatic vinyl compounds" are not used as polymer monomers. Strictly speaking, considering the possibility of their presence as impurities does not mean that the content is completely zero; for example, it means that the content is below the lower limit of values ​​that are normally detectable when used as polymer monomers, in the case of NMR analysis of the polymer structure.

[0074] In the hydrogenated diene polymer of this embodiment, it is preferable to hydrogenate a portion of the conjugated diene monomer unit after copolymerization of the conjugated diene monomer, thereby forming a structure comprising an ethylene structure and a conjugated diene monomer unit.

[0075] Furthermore, as described above, the hydrogenated diene polymer of this embodiment does not substantially contain structural units derived from aromatic vinyl compounds (hereinafter also referred to as "aromatic vinyl monomer units"). Therefore, when a rubber composition using the hydrogenated diene polymer of this embodiment is vulcanized, improved low-temperature performance can be achieved.

[0076] Therefore, in this specification, "substantially does not contain" means that it does not contain levels that would affect the low-temperature performance of the conjugated diene polymer. Specifically, since the content of aromatic vinyl monomer units tends to affect the low-temperature performance of the sulfide, it is preferable to suppress the content of aromatic vinyl monomer units to a level where the effect is 5% or less. As a specific concentration, it is preferably 0.1% by mass or less relative to the total mass of the hydrogenated diene polymer of this embodiment.

[0077] For example, since styrene and the like can easily affect the low fuel consumption performance of the rubber composition using the hydrogenated diene polymer of this embodiment after it has been vulcanized, the styrene content in the hydrogenated diene polymer of this embodiment is preferably 0.1% by mass or less.

[0078] Monomer units derived from monomers other than aromatic vinyl monomer units are preferably not at levels that would affect the low-temperature performance of sulfides of the hydrogenated diene polymers used in this embodiment.

[0079] Low-temperature performance is related to the degree of low elastic modulus of the rubber composition at low temperatures. The hydrogenated diene polymer of this embodiment, since it substantially does not contain aromatic vinyl monomer units, has a lower glass transition temperature and superior low-temperature performance compared to SBR. Furthermore, the composition ratio 'a' of the structural units represented by the above formula (1) formed in the diene polymer through hydrogenation contributes to a reduction in the elastic modulus at low temperatures. Based on this, the hydrogenation rate of the hydrogenated diene polymer of this embodiment is 40–85%, satisfying the mathematical formula (S): 10 ≦ [(a+b) / (a+b+c+d)] × 100 ≦ 70.

[0080] The preferred hydrogenation rate is 40-75%, satisfying the mathematical formula (S): 40≦[(a+b) / (a+b+c+d)]×100≦70.

[0081] More preferably, the hydrogenation rate is 40-60%, satisfying the mathematical formula (S): 50≦[(a+b) / (a+b+c+d)]×100≦70.

[0082] In the hydrogenated diene polymer of this embodiment, by making the hydrogenation rate and mathematical formula (S) within the above range, the structural unit represented by the above formula (1) is sufficiently present in the hydrogenated diene polymer, the composition ratio a is a sufficient value, and the rubber composition containing the hydrogenated diene polymer has excellent low-temperature performance.

[0083] It should be noted that in this specification, "monomer" refers to the compound before polymerization, and "monomer unit" refers to the structural unit that constitutes the polymer.

[0084] In addition, the "ethylene structure" includes both the structure generated by hydrogenating a portion of the double bond portion of the conjugated diene monomer unit and the ethylene monomer unit when ethylene is used as the monomer.

[0085] The hydrogenated diene polymer of this embodiment can be manufactured by hydrogenating conjugated diene monomers and, if necessary, other monomers after polymerization.

[0086] As a specific method, it is preferred to manufacture the product by means of methods described in publications such as International Publication No. 96 / 05250, Japanese Patent Application Publication No. 2000-053706, International Publication No. 2003 / 085010, International Publication No. 2019 / 151126, International Publication No. 2019 / 151127, International Publication No. 2002 / 002663, and International Publication No. 2015 / 006179: polymerizing the conjugated diene monomer by anionic polymerization under various additives and conditions, copolymerizing it with other monomers as needed, and then hydrogenating it.

[0087] Examples of conjugated diene monomers include, but are not limited to, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 3-methyl-1,3-pentadiene, 1,3-hexadiene, and 1,3-heptadiene. Among these, 1,3-butadiene and isoprene are preferred from the perspective of ease of industrial availability, and 1,3-butadiene is more preferred. They can be used individually or in combination of two or more.

[0088] In addition, other monomers include, but are not limited to, non-conjugated polyene monomers such as ethylene norbornene, dicyclopentadiene, and vinyl norbornene; and cyclic non-conjugated polyene monomers such as dicyclopentadiene, vinyl norbornene, and ethylene norbornene. By using such other monomers, there is a tendency to further improve the balance of sulfides, particularly in tire applications, in terms of breaking strength, low fuel consumption, wet grip, and abrasion resistance. They can be used alone or in combination of two or more.

[0089] (Hydrogenation rate)

[0090] The hydrogenation rate of the hydrogenated diene polymer in this embodiment is 40% or more, preferably 45% or more, more preferably 51% or more, and even more preferably 55% or more.

[0091] By increasing the hydrogenation rate to over 40%, the ethylene structure increases, and the molecular weight between the entanglement points of the molecular chains—that is, the minimum molecular weight of a molecular chain required to entangle one molecular chain with another—decreases. As a result, the number of molecular chain entanglements increases, and there is a tendency to further improve the fracture strength after the sulfide is made.

[0092] On the other hand, the hydrogenation rate of the hydrogenated diene polymer in this embodiment is 85% or less, preferably 80% or less, more preferably 75% or less, more preferably 71% or less, and even more preferably 65% ​​or less.

[0093] By keeping the hydrogenation rate below 85%, the ease of crosslinking is improved, and the hysteresis loss is reduced due to the absence of tiny crystals from the ethylene structure, which tends to further improve the low fuel consumption after the product is made into a sulfide.

[0094] Hydrogenation rate can be achieved through the use shown in the examples. 1 Calculated using the H-NMR method.

[0095] The hydrogenation rate of the hydrogenated diene polymer in this embodiment can be controlled within the above-mentioned numerical range by adjusting the amount of double bonds contained in the conjugated diene monomer unit.

[0096] (Branching degree)

[0097] From the perspective of suppressing cold flow after the rubber block is formed and improving processability, such as the ease of mixing with fillers and crosslinking agents, the degree of branching (Bn) (hereinafter simply referred to as "degree of branching (Bn)") of the hydrogenated diene polymer of this embodiment is 1.5 or more, preferably 3.0 or more, and more preferably 4.0 or more, as determined by the GPC-light scattering measurement method with a viscosity detector.

[0098] Branching degree (Bn) represents the number of polymer chains bonded to the longest polymer backbone.

[0099] For example, a branching degree (Bn) of 2 or more means that in the hydrogenated diene polymer of this embodiment, there are two or more side polymer chains on the substantially longest polymer backbone.

[0100] Regarding the degree of branching (Bn) of the hydrogenated diene polymer in this embodiment, the shrinkage factor (g') measured by GPC-light scattering method with viscosity detector is defined as g' = 6Bn / {(Bn+1)(Bn+2)}.

[0101] Generally, compared to straight-chain polymers with the same absolute molecular weight, branched polymers tend to have smaller molecular sizes.

[0102] The shrinkage factor (g') is an indicator of the proportion of a molecule's size relative to a linear polymer with the same absolute molecular weight. That is, the greater the degree of branching of the polymer, the smaller the shrinkage factor (g') tends to be.

[0103] Regarding this shrinkage factor, in the hydrogenated diene polymer of this embodiment, intrinsic viscosity is used as an indicator of molecular size, and linear polymers are set to conform to intrinsic viscosity [η] = -3.883M. 0.771 The relationship is given by the formula above, where M is the absolute molecular weight.

[0104] However, the shrinkage factor shows the rate of reduction in molecular size, but does not accurately represent the branched structure of the polymer.

[0105] Therefore, the degree of branching (Bn) of the hydrogenated diene polymer is calculated using the shrinkage factor (g') at each absolute molecular weight. The calculated degree of branching (Bn) accurately reflects the number of polymers directly or indirectly bonded to the longest main chain structure.

[0106] The calculated degree of branching (Bn) is an indicator of the branched structure of the hydrogenated diene polymer.

[0107] For example, in the case of a typical 4-arm star polymer (with 4 polymer chains connected in the central part), the branching degree (Bn) is evaluated as 2 when 2 polymer chains are bonded to the longest highly branched main chain structure.

[0108] In the case of a typical 8-arm star polymer, the arm with 6 polymer chains bonded to the longest highly branched main chain structure is evaluated as having a branching degree (Bn) of 6.

[0109] Here, "branch" refers to a polymer chain formed by direct or indirect bonding with other polymers relative to a single polymer. Additionally, "degree of branching (Bn)" refers to the number of polymers directly or indirectly bonded to the longest main chain structure.

[0110] By making the degree of branching (Bn) of the hydrogenated diene polymer of this embodiment 1.5 or more, cold flow after forming rubber blocks can be suppressed, the processability (workability) when making vulcanides is excellent, and the fracture strength and elongation at break after forming vulcanides are excellent.

[0111] From the same perspective, the degree of branching (Bn) of the hydrogenated diene polymer in this embodiment is preferably 3.0 or more, and more preferably 4.0 or more.

[0112] In addition, there is no particular limit to the upper limit of branching degree (Bn), which can be above the detection limit value, but is preferably 84 or less, more preferably 80 or less, even more preferably 64 or less, and even more preferably 57 or less.

[0113] In the hydrogenated diene polymer of this embodiment, by making the degree of branching (Bn) 84 or less, it tends to have excellent fracture strength and elongation at break when it is made into a sulfide.

[0114] (Mathematical expression (S))

[0115] In the hydrogenated diene polymer of this embodiment, when the composition ratio (mol%) of the structural unit represented by the following formula (1), the structural unit represented by the following formula (2), the structural unit represented by the following formula (3) and the structural unit represented by the following formula (4) are respectively set as a, b, c and d, the following mathematical formula (S) is satisfied.

[0116] Mathematical expression (S): 10≦[(a+b) / (a+b+c+d)]×100≦70

[0117] The proportions of a, b, c, and d mentioned above can be controlled by adjusting the type and amount of polar compound, the polymerization temperature, and the amount of hydrogen used in the reaction when polymerizing the polymer before hydrogenation.

[0118] [Chemistry 3]

[0119] 1) (2)

[0120] (3) (4)

[0121] The mathematical formula (S) above represents the molar ratio (mol%) of 1,2-vinyl bonds and hydrogenated 1,2-vinyl bonds in the hydrogenated diene polymer.

[0122] In the hydrogenated diene polymer of this embodiment, from the perspective of improving anti-slip properties, the above mathematical formula (S) is 10 mol% or more, more preferably 15 mol% or more, and even more preferably 20 mol% or more.

[0123] Furthermore, from the perspective of improving wear resistance, the above mathematical formula (S) is 70 mol% or less, preferably 60 mol% or less, more preferably 40 mol% or less, and even more preferably 30 mol% or less.

[0124] As a method to control the mathematical formula (S) within the aforementioned range, one can cite adjusting the polymerization temperature or adding polar compounds. For example, adding 0.1 molar equivalents of polar compound relative to 1 mole of organolithium compound can increase the 1,2-bond ratio by about 2%.

[0125] It should be noted that (a+c) / (a+b+c+d) calculated from a, b, c, and d above represents the hydrogenation rate mentioned above.

[0126] When a conjugated diene polymer composed of structural units represented by formula (2) and formula (4) is hydrogenated, the structural unit represented by formula (2) preferentially reacts and becomes the structural unit represented by formula (1). In the case of the hydrogenation reaction shown in this embodiment, when the total amount of structural units represented by formula (2) is set to 100 mol%, after 80 to 90 mol% of them are hydrogenated to become the structural unit represented by formula (1), there is a tendency for the reaction of the structural unit represented by formula (4) to begin.

[0127] The method for determining the above mathematical formula (S) caused by the butadiene bonding unit contained in the hydrogenated diene polymer of this embodiment is not particularly limited, and can be performed, for example, by the method described in the following examples.

[0128] (Mathematical expression (X))

[0129] In the hydrogenated diene polymer of this embodiment, when the composition ratio (mol%) of the structural units represented by the above formulas (1) to (4) is set as a, b, c, and d respectively, the following mathematical formula (X) using these a, b, c, and d is defined as follows.

[0130] The mathematical expression (X) = (a+c) / (a+b)

[0131] The mathematical formula (X) represents the linearity in the hydrogenated diene polymer, that is, the ratio of low-linearity repeating units to hydrogenated repeating units.

[0132] When the ratio of b and a, which are 1,2-vinyl bonds and hydrogenated 1,2-vinyl bonds, is low, the linearity of the molecule is high, the denominator decreases, and the mathematical formula (X) increases. Since a affects both the molecule and the denominator, the size of c tends to contribute to the size of the molecule. The larger the proportion of c, which is a structural unit in formula (3), the greater the tendency to exhibit crystallinity from the ethylene structural chain. Since the crystal structure causes the elastic modulus of the diene polymer to increase sharply, the rubber becomes harder.

[0133] The inventors believe that the mathematical formula (X) reflects the structure of the hydrogenated diene polymer and can express the properties described above. Using specific hydrogenated diene polymers, the relationship between specific values ​​and the properties of the hydrogenated diene polymers was investigated, and the following trend was found.

[0134] That is, the mathematical formula (X) is preferably 2.0 or less, more preferably 1.8 or less, and even more preferably 1.6 or less. By making the mathematical formula (X) 2.0 or less, it is possible to suppress the crystallization of the hydrogenated diene polymer from the ethylene structural chain, and a sharp increase in the elastic modulus can be avoided. As a result, the hydrogenated diene polymer of this embodiment does not become too hard, and the moldability of the block made of the hydrogenated diene polymer is excellent.

[0135] The formability of the rubber block can be determined by the method described in the examples below.

[0136] The mathematical formula (X) of the hydrogenated diene polymer in this embodiment is preferably 0.8 or more, more preferably 1.0 or more, and even more preferably 1.2 or more. When the mathematical formula (X) is 0.8 or more, as an example, the structure of the hydrogenated diene polymer satisfies a=32, b=8, c=0, d=60. In the hydrogenated diene polymer of this embodiment, when b and d coexist, b is preferentially hydrogenated. Therefore, by making the mathematical formula (X) 0.8 or more, the proportion of b, which is a reactive unsaturated group, in the hydrogenated diene polymer can be 8% or less, thereby improving the thermal stability of the hydrogenated diene polymer. As a result, gelation is less likely to occur during the compounding of rubber compositions using the hydrogenated diene polymer of this embodiment.

[0137] The above mathematical formula (X) can be controlled within the above numerical range by adjusting the type and amount of polar compound, the polymerization temperature, and the amount of hydrogen used in the reaction when polymerizing the unhydrogenated polymer.

[0138] (Modification rate)

[0139] In the hydrogenated diene polymer of this embodiment, nitrogen atoms are preferred from the viewpoint of improving the low fuel consumption after the product is made into a sulfide.

[0140] Nitrogen atoms can be introduced through modifiers. Therefore, the dispersibility of silica-based inorganic fillers used as tire reinforcement materials tends to be further improved.

[0141] In the hydrogenated diene polymer of this embodiment, from the perspective of the dispersibility of the silica-based inorganic filler as a tire reinforcement material, the modification rate is preferably 65% ​​by mass or more, more preferably 70% by mass or more, and even more preferably 75% by mass or more.

[0142] In the hydrogenated diene polymer of this embodiment, there is no particular upper limit to the modification rate. From the perspective of reducing the viscosity of the compound after mixing and improving processability, it is preferably 98% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less.

[0143] In this specification, "modification rate" refers to the mass ratio of the polymer with nitrogen-containing functional groups to the total amount of hydrogenated diene polymer.

[0144] The nitrogen atom can be introduced into the hydrogenated diene polymer in this embodiment at any position at the polymerization initiation end, in the molecular chain (including grafting), or at the polymerization end.

[0145] When the hydrogenated diene polymer of this embodiment is manufactured by polymerizing conjugated diene monomers and then hydrogenating them, from the perspectives of polymerization productivity, high modification rate, and low fuel consumption after the sulfide is produced, it is preferable to use a coupling agent containing nitrogen atoms to introduce nitrogen atoms.

[0146] As coupling agents containing nitrogen atoms, isocyanate compounds, isothiocyanate compounds, isocyanuric acid derivatives, carbonyl compounds containing nitrogen groups, vinyl compounds containing nitrogen groups, epoxy compounds containing nitrogen groups, and alkoxysilane compounds containing nitrogen groups are preferred from the perspective of polymerization productivity and high modification rate.

[0147] Furthermore, from the perspective of improving processability during sulfide production, a coupling agent with a high number of branches is preferred. The number of branches is not particularly limited, but from the perspective of suppressing cold flow, 3 or more branches are preferred, more preferably 4 or more branches. There is no particular upper limit to the number of branches, but from the perspective of productivity, 30 or fewer branches are preferred.

[0148] As coupling agents containing nitrogen atoms, alkoxysilane compounds containing nitrogen groups are preferred from the perspectives of polymerization productivity of hydrogenated diene polymers, high modification rate, and tensile strength after being made into tires.

[0149] Examples of nitrogen-containing alkoxysilane compounds include, but are not limited to, 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silazane, 2,2-diethoxy-1-(3-triethoxysilylpropyl)-1-aza-2-silazane, 2,2-dimethoxy-1-(4-trimethoxysilylbutyl)-1-aza-2-silazane, 2,2-dimethoxy-1-(5-trimethoxysilylpentyl)-1-aza-2-silazaneheptane, and 2,2- Dimethoxy-1-(3-dimethoxymethylsilylpropyl)-1-aza-2-silazopentane, 2,2-diethoxy-1-(3-diethoxyethylsilylpropyl)-1-aza-2-silazopentane, 2-methoxy-2-methyl-1-(3-trimethoxysilylpropyl)-1-aza-2-silazopentane, 2-ethoxy-2-ethyl-1-(3-triethoxysilylpropyl)-1-aza-2-silazopentane, 2-methoxy-2-methyl-1-(3-dimethoxymethylsilylpropyl) propyl)-1-aza-2-silazane, 2-ethoxy-2-ethyl-1-(3-diethoxyethylsilylpropyl)-1-aza-2-silazane, tris(3-trimethoxysilylpropyl)amine, tris(3-methyldimethoxysilylpropyl)amine, tris(3-triethoxysilylpropyl)amine, tris(3-methyldiethoxysilylpropyl)amine, tris(trimethoxysilylmethyl)amine, tris(2-trimethoxysilylethyl)amine, tris(4-trimethoxysilylbutyl)amine, tetra[3-( [2,2-Dimethoxy-1-aza-2-silazane-cyclopentane]-1,3-propanediamine, tetra(3-trimethoxysilylpropyl)-1,3-propanediamine, tetra(3-trimethoxysilylpropyl)-1,3-diaminomethylcyclohexane, and N1-(3-(bis(3-(trimethoxysilyl)propyl)amino)propyl)-N1-methyl-N3-(3-(methyl(3-(trimethoxysilyl)propyl)amino)propyl)-N3-(3-(trimethoxysilyl)propyl)-1,3-propanediamine.

[0150] In this embodiment, when the hydrogenated diene polymer is a copolymer of ethylene and a conjugated diene monomer, it is preferable to contain tin atoms, nitrogen atoms, and silicon atoms, considering the low oil consumption, wear resistance, and flexibility of the sulfide after it is made.

[0151] Furthermore, from the perspective of the manufacturability of hydrogenated diene polymers, it is preferable to use the following method: when the polymerization reaction reaches 100%, a coupling agent containing tin atoms, nitrogen atoms, and silicon atoms is used for introduction.

[0152] Examples of coupling agents containing tin, nitrogen, and silicon atoms include, but are not limited to, tin-containing compounds such as bis(1-octadecyl maleate) dioctyltin, isocyanate compounds such as 4,4-diphenylmethane diisocyanate, and alkoxysilane compounds such as glycidylpropyltrimethoxysilane.

[0153] (weight-average molecular weight)

[0154] From the perspectives of shape stability of the molded body of the rubber composition containing the hydrogenated diene polymer, tensile strength of the crosslinked body using the rubber composition, and wear resistance, the weight-average molecular weight of the hydrogenated diene polymer in this embodiment is preferably 150,000 or more, and more preferably 200,000 or more.

[0155] On the other hand, from the perspective of processability when the hydrogenated diene polymer of this embodiment is made into a crosslinking rubber composition, it is preferable to have a yield of 1 million or less, more preferably 500,000 or less, and even more preferably 400,000 or less.

[0156] From the perspective of low fuel consumption when using the hydrogenated diene polymer of this embodiment in sulfides, the molecular weight distribution (weight-average molecular weight / number-average molecular weight) of the hydrogenated diene polymer of this embodiment is preferably 2.0 or less, more preferably 1.8 or less, and even more preferably 1.6 or less.

[0157] On the other hand, from the perspective of processability when the hydrogenated diene polymer of this embodiment is made into a crosslinking rubber composition, the molecular weight distribution of the hydrogenated diene polymer is preferably 1.05 or more, more preferably 1.2 or more, and even more preferably 1.4 or more.

[0158] The weight-average molecular weight and molecular weight distribution can be calculated based on the molecular weight of polystyrene determined by GPC (gel permeation chromatography).

[0159] (additive)

[0160] The hydrogenated diene polymer of this embodiment can be supplemented with additives such as deactivators and neutralizers as needed in the final stage of the polymerization process.

[0161] Examples of deactivating agents include, but are not limited to, water; methanol, ethanol, isopropanol, and other alcohols.

[0162] It should be noted that the final stage of the polymerization process refers to the state in which more than 95% of the added monomers are consumed during polymerization.

[0163] Examples of neutralizing agents include, but are not limited to, carboxylic acids such as stearic acid, oleic acid, and tertiary carbonic acid (a mixture of multi-branched carboxylic acids with 9 to 11 carbon atoms, with 10 as the central element); aqueous solutions of inorganic acids; and carbon dioxide.

[0164] In addition, from the perspective of preventing gel formation and improving processing stability, it is preferable to add a rubber stabilizer at the final stage of the polymerization process of the hydrogenated diene polymer.

[0165] As stabilizers for rubber, antioxidants such as, but not limited to, 2,6-di-tert-butyl-4-hydroxytoluene (hereinafter also referred to as "BHT"), octadecyl 3-(4'-hydroxy-3',5'-di-tert-butylphenol)propionate, and 2-methyl-4,6-bis[(octylthio)methyl]phenol are preferred substances.

[0166] In addition, rubber softeners can be added as needed in the final stage of the polymerization process of hydrogenated diene polymers to improve polymer productivity and processability when inorganic fillers are mixed in during tire manufacturing.

[0167] There are no particular limitations on rubber softeners; examples include filler oils, liquid rubbers, and resins. However, filler oils are preferred from the perspectives of processability, productivity, and economy.

[0168] As a method for adding a rubber softener to the hydrogenated diene polymer of this embodiment, the following method is preferred, but not limited to: adding a rubber softener to a polymer solution, mixing to prepare a polymer solution containing a rubber softener, and then desolventizing it.

[0169] Preferred filler oils include, for example, aromatic oils, cycloalkanes, and paraffins. Among these, from the perspectives of environmental safety, prevention of oil seepage, and anti-slip properties, alternative aromatic oils with a polycyclic aromatic (PCA) content of 3% by mass or less based on the IP346 standard are preferred.

[0170] As alternative aromatic oils, examples include TDAE (Treated Distillate Aromatic Extracts), MES (Mild Extraction Solvate), and RAE (Residual Aromatic Extracts), as shown in Kautschuk Gummi Kunststoffe 52(12)799(1999).

[0171] From the perspective of suppressing the deterioration of tires over the years, the content of filler oil in the rubber composition using the hydrogenated diene polymer of this embodiment is preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 10% by mass or less, and even more preferably 5% by mass or less.

[0172] Preferred resins include, but are not limited to, aromatic petroleum resins, benzofuran-indene resins, terpene resins, rosin derivatives (including tung oil resins), tall oil, tall oil derivatives, rosin ester resins, natural and synthetic terpene resins, aliphatic hydrocarbon resins, aromatic hydrocarbon resins, mixed aliphatic / aromatic hydrocarbon resins, coumarin-indene resins, phenol resins, p-tert-butylphenol-acetylene resins, phenol-formaldehyde resins, xylene-formaldehyde resins, oligomers of monoolefins, oligomers of dienes, hydrogenated aromatic hydrocarbon resins, cyclic aliphatic hydrocarbon resins, hydrogenated hydrocarbon resins, hydrocarbon resins, hydrogenated tung oil resins, hydrogenated oil resins, and esters of hydrogenated oil resins with monofunctional or polyfunctional alcohols.

[0173] These resins can be used in one or more combinations. During hydrogenation, all unsaturated groups can be hydrogenated, or some may remain.

[0174] In addition to improving the processability of rubber compositions made by blending hydrogenated diene polymers and fillers, the effect of adding resins can also be attributed to improving the breaking strength of the resulting sulfide.

[0175] The amount of filler oil, liquid rubber, or resin added as a rubber softener is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 20 parts by mass or more, relative to 100 parts by mass of the hydrogenated diene polymer. By setting the amount added within this range, it is desirable to obtain a rubber composition with excellent abrasion resistance and crack resistance. In addition, from the perspective of improving low oil consumption, it is preferably 35 parts by mass or less, more preferably 30 parts by mass or less, and even more preferably 25 parts by mass or less.

[0176] As a method for obtaining the hydrogenated diene polymer of this embodiment by removing the solvent from the polymer solution, known methods can be used. Examples of such methods include: separating the solvent by stripping or the like, filtering out the hydrogenated diene polymer, and further dehydrating and drying it to obtain the hydrogenated diene polymer; concentrating it using a flash tank and further performing devolatilization using an exhaust extruder or the like; and directly performing devolatilization using a rotary dryer or the like.

[0177] (Aluminum content)

[0178] The hydrogenated diene polymer of this embodiment preferably has an aluminum content of less than 2 ppm. When the aluminum content is within this range, it tends to suppress the increase in viscosity of the hydrogenated diene polymer of this embodiment over time.

[0179] The reason why the viscosity of the hydrogenated diene polymer of this embodiment can be suppressed from increasing over time by keeping the aluminum concentration low is as follows. Specifically, it is believed that when the aluminum content in the hydrogenated diene polymer is 2 ppm or higher, the dispersion obtained by dispersing the aluminum-containing compound in particulate form interacts with the heteroatoms of the hydrogenated diene polymer and the residues of the coupling agent, causing the viscosity to increase. Therefore, by keeping the aluminum content below 2 ppm, this increase in viscosity can be suppressed.

[0180] Especially when the hydrogenated diene polymer contains nitrogen atoms, and when these nitrogen atoms readily form primary amines, and when it contains coupling agents with alkoxysilanes, the effect of suppressing viscosity increase over time is significant by keeping the aluminum content less than 2 ppm.

[0181] The aluminum content of the hydrogenated diene polymer can be determined by the method described in the examples below, and can be controlled within the above-mentioned range by adjusting the type and amount of polymerization catalyst and hydrogenation catalyst, deashing, or the conditions of the solvent removal process described below.

[0182] [Method for manufacturing hydrogenated diene polymers]

[0183] The hydrogenated diene polymer of this embodiment can be manufactured through a polymerization process, a modification process, and a hydrogenation process.

[0184] (Polymerization process)

[0185] There are no particular restrictions on the polymerization method in the polymerization process. Any of the following methods can be used: solution polymerization, gas-phase polymerization, and bulk polymerization. However, from a commercial production perspective, solution polymerization is particularly preferred.

[0186] Furthermore, regarding the polymerization method, in this embodiment, a batch polymerization method is preferred from the perspective of suppressing side reactions and easily controlling the molecular structure.

[0187] When using solution polymerization, the monomer concentration in the solution is preferably 5% by mass or more, more preferably 10% by mass or more. Maintaining a monomer concentration of 5% by mass or more ensures a sufficient amount of polymer is obtained, which is preferable from a cost perspective. Furthermore, the monomer concentration in the solution is preferably 50% by mass or less, more preferably 30% by mass or less. A monomer concentration of 50% by mass or less prevents the solution viscosity from becoming too high, facilitates stirring, and promotes ease of polymerization.

[0188] <Polymerization initiator>

[0189] In the case of anionic polymerization in the polymerization process, there are no particular restrictions on the polymerization initiator, but organolithium compounds are preferred.

[0190] As organolithium compounds, organolithium compounds having alkyl groups having 2 to 20 carbon atoms are preferred. Examples include, but are not limited to, ethyl lithium, n-propyl lithium, isopropyl lithium, n-butyl lithium, sec-butyl lithium, tert-butyl lithium, tert-octyl lithium, n-decyl lithium, phenyl lithium, 2-naphthyl lithium, 2-butyl-phenyl lithium, 4-phenyl-butyl lithium, cyclohexyl lithium, cyclopentyl lithium, and the reaction product of diisopropenylbenzene and butyl lithium. Among these, n-butyl lithium and sec-butyl lithium are preferred from the perspectives of ease of acquisition and safety.

[0191] In the case of coordination polymerization in the polymerization process, the polymerization catalyst composition described in Japanese Patent Application Publication No. 2020-45500 is preferably used as the polymerization initiator.

[0192] <Aggregation Methods>

[0193] There are no particular restrictions on the method of producing diene polymers by using a polymerization initiator to anionicly polymerize or coordinately polymerize a specified monomer; existing known methods can be used.

[0194] Specifically, in a reaction-inert organic solvent, such as aliphatic, alicyclic, or aromatic hydrocarbon compounds, 1,3-butadiene, ethylene, etc., can be polymerized in the presence of a polar compound, for example, by using butyllithium as a polymerization initiator, thereby obtaining the target diene polymer.

[0195] <Hydrocarbon solvents>

[0196] As a hydrocarbon solvent, hydrocarbons with 3 to 8 carbon atoms are preferred, including but not limited to propane, n-butane, isobutane, n-pentane, isopentane, n-hexane, cyclohexane, propylene, 1-butene, isobutene, trans-2-butene, cis-2-butene, 1-pentene, 2-pentene, 1-hexene, 2-hexene, benzene, toluene, xylene, ethylbenzene, etc.

[0197] They can be used individually or in combination of two or more.

[0198] <Polar Compounds in Anionic Polymerization>

[0199] Polar compounds can be added during the polymerization process.

[0200] Polar compounds are compounds used to control the microstructure of the conjugated diene moiety in polymers. Examples include compounds that increase the number of 1,2-bonds in butadiene and 3,4-bonds in isoprene.

[0201] There are no particular restrictions on the polar compound used; any known compound that is conventionally used as a polar compound can be used. Examples include, but are not limited to, ethers and tertiary amines such as dimethoxybenzene, tetrahydrofuran, dimethoxyethane, diethylene glycol dibutyl ether, diethylene glycol dimethyl ether, 2,2-bis(2-tetrahydrofuranyl)propane, triethylamine, pyridine, N-methylmorpholine, N,N,N',N'-tetramethylethylenediamine, and 1,2-dipiperidinylethane. Potassium salts such as potassium tert-amyloxide and potassium tert-butoxide, and sodium salts such as sodium tert-amyloxide can also be used.

[0202] These polar compounds can be used alone or in combination of two or more.

[0203] Furthermore, the amount of the polar compound used is preferably 0.01 molar equivalents or more, more preferably 0.05 molar equivalents or more, relative to 1 mole of the organolithium compound used as a polymerization initiator. The polar compound is also known as a vinylizing agent. By using 0.01 molar equivalents or more of the polar compound, an additive effect can be obtained, and it tends to easily increase 1,2-bonds. For example, when 0.1 molar equivalents are added relative to 1 mole of the organolithium compound, the 1,2-bond ratio can be increased by about 2%. Additionally, the amount of the polar compound used as a vinylizing agent is preferably 1000 molar equivalents or less, more preferably 500 molar equivalents or less, relative to 1 mole of the organolithium compound. By using 1000 molar equivalents or less of the polar compound, significant changes in the monomer reaction rate can be prevented, and it tends to control the polymerization reaction.

[0204] <Reaction Temperature>

[0205] Regarding the reaction temperature during polymerization, there is no particular limitation as long as the reaction can proceed appropriately, but it is preferably -10℃ to 100℃, more preferably 25℃ to 70℃.

[0206] (Modification process)

[0207] By reacting the active ends of the diene polymer obtained from the above polymerization process with a compound having functional groups that interact with silica, functional groups that interact with silica can be introduced into the polymerization termination ends of the diene polymer. This yields a diene polymer with modified polymerization termination ends.

[0208] In the modification reaction (hereinafter also referred to as the end modification reaction), the diene polymer used can have an active end, and the polymerization start end can be either unmodified or modified.

[0209] Furthermore, the compounds used in the modification process are not particularly limited as long as they have functional groups that interact with silicon dioxide and can react with the active ends of the polymer. For example, end modifiers containing tin or nitrogen atoms are preferred, and end modifiers containing nitrogen atoms are more preferred.

[0210] The modification process also includes a coupling process that involves an increase in molecular weight.

[0211] Specifically, atactic diene polymers with branched structures can be obtained by reacting a coupling agent with two or more reaction sites with the active ends of the polymer.

[0212] Just as coupling agents containing nitrogen are called modifiers, coupling effects can be achieved through a modification process by selecting compounds with coupling functions as modifiers.

[0213] In modification reactions involving an increase in molecular weight, the modification rate (coupling rate) affects the molecular weight distribution of the modified polymer. Therefore, from the perspective of controlling the molecular weight distribution to be below 1.75, the modification rate is preferably 65% ​​by mass or more, more preferably 70% by mass or more, and even more preferably 75% by mass or more.

[0214] When a modifier with two or more functional groups is used to carry out the modification process, a multi-branched polymer is generated through a coupling reaction. However, regardless of the number of functional groups, if the modification rate is high, the molecular weight distribution tends to shift while maintaining sharpness.

[0215] The structure of the modifier has little effect on the molecular weight distribution, so the modifier can be selected based on the desired function of the modified diene polymer.

[0216] It should be noted that the modification rate can be determined using the method described in the examples below.

[0217] As end modifiers containing nitrogen atoms, from the perspective of polymerization productivity and high modification rate, preferred substances include isocyanate compounds, isothiocyanate compounds, isocyanuric acid derivatives, carbonyl compounds containing nitrogen groups, vinyl compounds containing nitrogen groups, epoxy compounds containing nitrogen groups, and alkoxysilane compounds containing nitrogen groups.

[0218] As end modifiers containing nitrogen atoms, alkoxysilane compounds containing nitrogen groups are preferred from the perspectives of polymerization productivity, high modification rate, and tensile strength when made into tires.

[0219] Examples of nitrogen-containing alkoxysilane compounds include, but are not limited to, 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silazane, 2,2-diethoxy-1-(3-triethoxysilylpropyl)-1-aza-2-silazane, 2,2-dimethoxy-1-(4-trimethoxysilylbutyl)-1-aza-2-silazane, 2,2-dimethoxy-1-(5-trimethoxysilylpentyl)-1-aza-2-silazaneheptane, and 2,2-di... Methoxy-1-(3-dimethoxymethylsilylpropyl)-1-aza-2-silazopentane, 2,2-diethoxy-1-(3-diethoxyethylsilylpropyl)-1-aza-2-silazopentane, 2-methoxy-2-methyl-1-(3-trimethoxysilylpropyl)-1-aza-2-silazopentane, 2-ethoxy-2-ethyl-1-(3-triethoxysilylpropyl)-1-aza-2-silazopentane, 2-methoxy-2-methyl-1-(3-dimethoxymethylsilylpropyl) )-1-aza-2-silazopentane, and 2-ethoxy-2-ethyl-1-(3-diethoxyethylsilylpropyl)-1-aza-2-silazopentane, tris(3-trimethoxysilylpropyl)amine, tris(3-methyldimethoxysilylpropyl)amine, tris(3-triethoxysilylpropyl)amine, tris(3-methyldiethoxysilylpropyl)amine, tris(trimethoxysilylmethyl)amine, tris(2-trimethoxysilylethyl)amine, and tris(4-trimethoxysilylbutyl)amine, tetra[3- [2,2-Dimethoxy-1-aza-2-silazopentane]-1,3-propanediamine, tetra(3-trimethoxysilylpropyl)-1,3-propanediamine, tetra(3-trimethoxysilylpropyl)-1,3-diaminomethylcyclohexane, and N1-(3-(bis(3-(trimethoxysilyl)propyl)amino)propyl)-N1-methyl-N3-(3-(methyl(3-(trimethoxysilyl)propyl)amino)propyl)-N3-(3-(trimethoxysilyl)propyl)propyl)-1,3-propanediamine.

[0220] The end-modification reaction of the polymer can be carried out, for example, in the form of a solution reaction. This solution reaction can be carried out using a solution containing unreacted monomers from the polymerization process, or it can be carried out after separating and dissolving the polymer in the solution in a suitable solvent such as cyclohexane. Furthermore, in the case of a continuous polymerization process, the end-modification reaction is also preferably continuous.

[0221] There are no particular restrictions on the method of adding end modifiers; examples include uniform addition, multiple additions, and continuous addition.

[0222] The amount of compound used in the end-modification reaction can be appropriately set according to the type of compound used in the reaction. It is preferably 0.1 molar equivalent or more, more preferably 0.3 molar equivalent or more, relative to 1 mole of metal atoms participating in the polymerization reaction contained in the polymerization initiator. By setting it to 0.1 molar equivalent or more, the modification reaction can be carried out sufficiently, and the dispersibility of silica can be appropriately improved in the rubber composition containing the modified polymer and silica.

[0223] The temperature of the end-modification reaction is usually the same as that of the polymerization reaction described above, preferably -20 to 150°C, more preferably 0 to 120°C, and even more preferably 20 to 100°C. If the temperature of the modification reaction is low, the viscosity of the modified polymer tends to increase.

[0224] On the other hand, if the temperature of the modification reaction is high, the active ends of the polymerization are easily deactivated. The reaction time of the modification reaction is preferably 1 minute to 5 hours, more preferably 2 minutes to 1 hour.

[0225] (Reaction termination process)

[0226] In the case of anionic polymerization in the polymerization process, the polymerization reaction can be terminated by adding a known reaction terminator. Examples of reaction terminators include, but are not limited to, alcohols such as methanol, ethanol, and isopropanol; polar solvents with active protons such as acetic acid; mixtures thereof; or mixtures of the above polar solvents with nonpolar solvents such as hexane and cyclohexane.

[0227] The amount of reaction terminator added is usually preferably the same as or twice the molar amount of the anionic polymerization initiator.

[0228] (Hydrogenation process)

[0229] In the method for manufacturing the hydrogenated diene polymer of this embodiment, there are no particular limitations on the hydrogenation method or reaction conditions; hydrogenation can be carried out using known methods under known conditions.

[0230] It is usually carried out in the presence of a hydrogenation catalyst under hydrogen pressure of 20–150°C and 0.1–10 MPa.

[0231] It should be noted that the hydrogenation rate can be controlled by adjusting the amount of hydrogenation catalyst, the hydrogen pressure during the hydrogenation reaction, and the reaction time.

[0232] As hydrogenation catalysts, compounds containing any element from Groups 4 to 11 of the periodic table can generally be used. Such compounds can be, but are not limited to, those containing Ti, V, Co, Ni, Zr, Ru, Rh, Pd, Hf, Re, and Pt atoms. More specifically, examples include metallocene compounds of Ti, Zr, Hf, Co, Ni, Pd, Pt, Ru, Rh, and Re; supported heterogeneous catalysts consisting of metals such as Pd, Ni, Pt, Rh, and Ru supported on carbon, silica, alumina, diatomaceous earth, etc.; homogeneous Ziegler-type catalysts consisting of organic salts or acetylacetone salts of metals such as Ni and Co combined with reducing agents such as organoaluminum; organometallic compounds or complexes of Ru and Rh; and hydrogen-containing fullerenes and carbon nanotubes.

[0233] Among these, metallocene compounds containing any one of Ti, Zr, Hf, Co, and Ni are preferred from the perspective of being able to undergo a homogeneous hydrogenation reaction in an inert organic solvent. Furthermore, metallocene compounds containing any one of Ti, Zr, and Hf are even more preferred.

[0234] Hydrogenation catalysts can be used alone or in combination of two or more.

[0235] The preferred method for manufacturing the hydrogenated diene polymer of this embodiment is as follows: performing solution polymerization, directly using the obtained polymer solution and performing a modification process as needed, and then performing a hydrogenation process as needed.

[0236] The hydrogenated diene polymer of this embodiment is obtained by desolventizing and separating the polymer from the polymer solution obtained above. Examples of methods for separating the polymer include known desolventizing methods such as stripping, and methods involving drying operations such as heat treatment using a dehydrating extruder, a drying extruder, or a conveyor.

[0237] [Glue block]

[0238] The adhesive block in this embodiment is formed by molding the hydrogenated diene polymer described in this embodiment.

[0239] The rubber block is a block-shaped molded body, preferably 1000cm. 3 The above-mentioned molded body. Alternatively, a rectangular block weighing 17.5 kg to 35 kg is more preferred.

[0240] The molding compression pressure of the molded body is preferably 3 to 30 MPa, more preferably 10 to 20 MPa. When the compression pressure during molding is below 30 MPa, the device can be designed to be compact and the installation efficiency is good; when the compression pressure during molding is above 3 MPa, the moldability is good.

[0241] The temperature of the hydrogenated diene polymer during molding is preferably 30–120°C, and more preferably 50–100°C to reduce residual solvent and suppress thermal degradation.

[0242] When the temperature of the hydrogenated diene polymer during molding is above 30°C, the molding properties are good. On the other hand, when the temperature is below 120°C, gel formation caused by thermal degradation of the rubber composition can be suppressed, which is therefore preferred.

[0243] The higher the temperature and pressure during molding, the smaller the specific surface area of ​​the rubber block.

[0244] The holding time during molding is preferably 3 to 30 seconds, more preferably 5 to 20 seconds. When the holding time during compression is less than 30 seconds, the production efficiency is good, and when it is more than 5 seconds, the formability is good.

[0245] To avoid the molded parts from sticking together, it is preferable to use resin film (packaging sheet) for packaging.

[0246] Regarding the type of resin used in the membrane, for example, polyethylene, ethylene copolymer resin, polystyrene, high-impact polystyrene, and PET can be used.

[0247] From the perspectives of ease of handling during transport of the molded body and minimizing condensation in the gap between the packaging sheet and the rubber block, the packaging sheet with good sealing properties is preferred.

[0248] [Rubber Composition]

[0249] The rubber composition of this embodiment contains 100 parts by weight of rubber component (which includes the hydrogenated diene polymer and other diene rubbers of this embodiment described above) and 20 to 100 parts by weight of silica-based inorganic filler.

[0250] In this embodiment, the hydrogenated diene polymer in 100 parts by weight of the rubber component is preferably 10 parts by weight or more, more preferably 20 parts by weight or more, and even more preferably 30 parts by weight or more.

[0251] By ensuring the amount of hydrogenated diene polymer in the rubber component is within the aforementioned range, there is a tendency for excellent breaking strength after the vulcanization is produced. Furthermore, from the perspective of excellent processability during vulcanization production, 50 parts by weight or less is preferred, more preferably 45 parts by weight or less, and even more preferably 40 parts by weight or less.

[0252] The rubber composition of this embodiment preferably comprises a diene-based rubber other than the hydrogenated diene polymer of this embodiment. Examples of such diene-based polymers include, but are not limited to, conjugated diene polymers or their hydrogenates, random copolymers of conjugated diene compounds and vinyl aromatic compounds or their hydrogenates, block copolymers of conjugated diene compounds and vinyl aromatic compounds or their hydrogenates, non-diene polymers, and natural rubber.

[0253] Specifically, examples include, but are not limited to, styrene-based elastomers such as butadiene rubber or its hydrogenated form, isoprene rubber or its hydrogenated form, styrene-butadiene rubber or its hydrogenated form, styrene-butadiene block copolymer or its hydrogenated form, styrene-isoprene block copolymer or its hydrogenated form, and nitrile rubber or its hydrogenated form.

[0254] The hydrogenated diene polymer of this embodiment has compatibility parameters similar to those of natural rubber, and therefore can generally also function as a compatibilizer for natural rubber and other rubbers. Specifically, the rubber composition consisting of a rubber incompatible with natural rubber, natural rubber, and the hydrogenated diene polymer of this embodiment exhibits excellent abrasion resistance and elongation at break, properties that cannot be achieved without the hydrogenated diene polymer of this embodiment.

[0255] The rubber composition described above is not particularly limited, and examples include a rubber composition consisting of the hydrogenated diene polymer of this embodiment, natural rubber, and high cis-butadiene.

[0256] Examples of natural rubber include, but are not limited to, RSS3-5, SMR, and epoxidized natural rubber, which are used as smoked sheets.

[0257] Other diene-based rubbers besides the hydrogenated diene polymers described in these embodiments can be modified rubbers endowed with polar functional groups such as hydroxyl and amino groups. For tire applications, butadiene rubber, isoprene rubber, styrene-butadiene rubber, natural rubber, and butyl rubber are preferred.

[0258] In addition, the rubber composition of this embodiment can be used in combination with non-diene polymers.

[0259] Examples of non-diene polymers include, but are not limited to, olefin elastomers such as ethylene-propylene rubber, ethylene-propylene-diene rubber, ethylene-butene-diene rubber, ethylene-butene rubber, ethylene-hexene rubber, and ethylene-octene rubber; butyl rubber; brominated butyl rubber; acrylic rubber; fluororubber; silicone rubber; chlorinated polyethylene rubber; epichlorohydrin rubber; α,β-unsaturated nitrile-acrylate-conjugated diene copolymer rubber; polyurethane rubber; and polysulfide rubber.

[0260] Regarding the weight-average molecular weight of the diene rubbers other than the hydrogenated diene polymer used in this embodiment and the non-diene rubbers used in the rubber composition of this embodiment, from the perspective of balancing performance and processing characteristics, a weight-average molecular weight of 2,000 to 2,000,000 and a weight-average molecular weight of 5,000 to 1,500,000 is preferred, and a weight-average molecular weight of 5,000 to 1,500,000 is more preferable. Alternatively, low molecular weight diene rubbers or non-diene rubbers, i.e., so-called liquid rubbers, may also be used. One type of diene rubber or non-diene rubber may be used alone, or two or more may be used in combination.

[0261] In addition, the rubber composition of this embodiment contains a silica-based inorganic filler.

[0262] In the rubber composition of this embodiment, by dispersing the silica-based inorganic filler, there is a tendency for better processability when making sulfides, and a tendency for better balance between abrasion resistance, breaking strength, low hysteresis loss and anti-slip properties after sulfide formation.

[0263] The rubber composition of this embodiment, by containing a silica-based inorganic filler, can be appropriately used in vulcanized rubber applications for automotive parts such as tires and vibration damping rubber, as well as shoes.

[0264] From the perspective of excellent wear resistance and breaking strength after being made into a sulfide, the content of silica-based inorganic filler in the rubber composition of this embodiment is 20 parts by mass or more, preferably 50 parts by mass or more, more preferably 60 parts by mass or more, and even more preferably 70 parts by mass or more, relative to 100 parts by mass of the rubber component including the hydrogenated diene polymer of this embodiment and other diene-based rubbers.

[0265] Furthermore, from the perspective of excellent processability during the production of sulfides and the excellent balance between low hysteresis loss and anti-slip properties after the sulfides are produced, the content is 100 parts by weight or less, preferably 90 parts by weight or less, more preferably 85 parts by weight or less, and even more preferably 80 parts by weight or less.

[0266] There are no particular limitations on silica-based inorganic fillers; known substances can be used. Solid particles containing SiO2 or Si3Al as structural units are preferred, and solid particles containing SiO2 or Si3Al as the main structural unit are even more preferred.

[0267] Here, the main component refers to the component contained in the silica-based inorganic filler, which is 50% or more by mass, preferably 70% or more by mass, and more preferably 80% or more by mass.

[0268] Specific examples of silica-based inorganic fillers include, but are not limited to, inorganic fibrous materials such as silica, clay, talc, mica, diatomaceous earth, wollastonite, montmorillonite, zeolite, and glass fiber. Other examples include silica-based inorganic fillers with hydrophobicated surfaces, and mixtures of silica-based inorganic fillers with inorganic fillers other than silica. Among these, silica and glass fiber are preferred from the perspectives of strength and wear resistance, with silica being more preferred. Examples of silica include, for instance, dry silica, wet silica, and synthetic silicate silica. Among these silicas, wet silica is preferred from the perspective of a superior balance between improved breaking strength and anti-slip properties.

[0269] In the rubber composition of this embodiment, from the perspective of obtaining practically good abrasion resistance and breaking strength, the nitrogen adsorption specific surface area of ​​the silica-based inorganic filler, determined by the BET adsorption method, is preferably 100 m². 2 / g or more 300m 2 / g or less, more preferably 170m 2 / g or more 250m 2 / g or less. Additionally, products with smaller specific surface areas (e.g., specific surface area less than 200m²) can be supplied as needed. 2 / g) of silica-based inorganic filler with a large specific surface area (e.g., 200m²) 2 The rubber composition of this embodiment uses a combination of silica-based inorganic fillers with a specific surface area of ​​200 m² or more. 2 In the case of silica-based inorganic fillers (at least / g), the dispersibility of silica is improved in the rubber composition containing the hydrogenated diene polymer of this embodiment, which is particularly effective in improving abrasion resistance and tends to achieve a high balance between good breaking strength and low hysteresis loss.

[0270] The rubber composition of this embodiment may contain fillers other than silica-based inorganic fillers. Examples of such fillers include carbon black, metal oxides, and metal hydroxides.

[0271] Examples of carbon black include, but are not limited to, various grades such as SRF, FEF, HAF, ISAF, and SAF. Among these, carbon black with a nitrogen adsorption specific surface area of ​​50 m² is preferred. 2 Carbon black with an oil absorption of 80 mL / 100 g or more and a dibutyl phthalate (DBP) oil absorption of 80 mL / 100 g or less.

[0272] In the rubber composition of this embodiment, the carbon black content is preferably 0.5 parts by mass or more but less than 100 parts by mass, more preferably 3.0 parts by mass or more but less than 100 parts by mass, and even more preferably 5.0 parts by mass or more but less than 50 parts by mass, relative to 100 parts by mass of the rubber component containing the hydrogenated diene polymer of this embodiment. In the rubber composition of this embodiment, from the perspective of exhibiting dry grip performance, electrical conductivity, and other properties required for applications such as tires, the carbon black content is preferably 0.5 parts by mass or more relative to 100 parts by mass of the rubber component; from the perspective of dispersibility, the carbon black content is preferably less than 100 parts by mass relative to 100 parts by mass of the rubber component.

[0273] Metal oxides are solid particles whose main structural units are the chemical formula MxOy (where M represents a metal atom, and x and y each independently represent integers from 1 to 6).

[0274] Examples of metal oxides include, but are not limited to, aluminum oxide, titanium oxide, magnesium oxide, and zinc oxide.

[0275] Examples of metal hydroxides include, but are not limited to, aluminum hydroxide, magnesium hydroxide, and zirconium hydroxide.

[0276] The rubber composition of this embodiment may contain a silane coupling agent. The silane coupling agent preferably has the function of strengthening the interaction between the rubber component and the inorganic filler, has groups having affinity or bonding with the rubber component and the silica-based inorganic filler respectively, and is a compound having a sulfur-bonded portion and an alkoxysilyl or silanol portion in one molecule. Such compounds are not particularly limited; examples include bis-[3-(triethoxysilyl)-propyl]-tetrasulfide, bis-[3-(triethoxysilyl)-propyl]-disulfide, and bis-[2-(triethoxysilyl)-ethyl]-tetrasulfide.

[0277] In the rubber composition of this embodiment, the content of the silane coupling agent is preferably 0.1 parts by mass or more and 30 parts by mass or less, more preferably 0.5 parts by mass or more and 20 parts by mass or less, and even more preferably 1.0 parts by mass or more and 15 parts by mass or less, relative to 100 parts by mass of the aforementioned silica-based inorganic filler. When the content of the silane coupling agent is within the above range, there is a tendency to make the above-mentioned additive effects brought about by the silane coupling agent more significant.

[0278] The rubber composition of this embodiment may include a rubber softener from the perspective of improving its processability.

[0279] Regarding the amount of rubber softener added, relative to 100 parts by mass of the rubber component containing the hydrogenated diene polymer of this embodiment, it is expressed as the amount of rubber softener that is pre-included in the hydrogenated diene polymer and other diene-based rubbers, and the total amount of rubber softener added when making the rubber composition.

[0280] As a rubber softener, it is suitable for use with filler oils, liquid rubbers, and resins.

[0281] Mineral oil-based rubber softeners, known as process oils or extender oils, are used to soften, compatibilize, and improve the processability of rubber. They are mixtures of aromatic rings, cycloalkane rings, and alkanes. Substances in which the carbon atoms of the alkane chain account for more than 50% of the total carbon are called alkane systems. Substances in which the carbon atoms of the cycloalkane ring account for more than 30% but less than 45% of the total carbon are called cycloalkane systems. Substances in which the aromatic carbon atoms account for more than 30% of the total carbon are called aromatic systems.

[0282] In the rubber composition of this embodiment, the content of the rubber softener relative to 100 parts by mass of the rubber component is preferably 0 parts by mass or more than 100 parts by mass, more preferably 10 parts by mass or more than 90 parts by mass, and even more preferably 30 parts by mass or more than 90 parts by mass. By keeping the content of the rubber softener relative to 100 parts by mass of the rubber component at 100 parts by mass, there is a tendency to suppress exudation and suppress the stickiness of the rubber composition surface.

[0283] In this embodiment, the rubber composition preferably includes liquid rubber from the perspective of improving low-temperature performance.

[0284] Examples of liquid rubbers include liquid butadiene rubber, liquid styrene-butadiene rubber, and liquid isoprene rubber. These liquid rubbers can be used individually or in combination of two or more types.

[0285] By adding liquid rubber, the rubber composition of this embodiment exhibits a decrease in elastic modulus at low temperatures, thus tending to have excellent low-temperature performance. Furthermore, the liquid rubber selected above possesses unsaturated bonds within its molecules, and by combining with the rubber components during the vulcanization of the rubber composition, it tends to increase its breaking strength.

[0286] The molecular weight of the liquid rubber is preferably 1000 or more, more preferably 1500 or more. By keeping the molecular weight within this range, the number of entanglements in the molecular chains constituting the liquid rubber increases, tending to result in excellent breaking strength. Furthermore, the molecular weight of the liquid rubber is preferably 10000 or less, more preferably 9000 or less. By keeping the molecular weight within this range, the viscosity decreases, resulting in excellent processability when producing vulcanizates.

[0287] Relative to 100 parts by mass of the rubber component containing the hydrogenated diene polymer of this embodiment, the amount of liquid rubber added to the rubber composition of this embodiment is preferably 2 parts by mass or more, more preferably 5 parts by mass or more, and even more preferably 10 parts by mass or more. By keeping the amount added within this range, the elastic modulus of the rubber composition decreases at low temperatures, tending to exhibit excellent low-temperature performance. Furthermore, from the perspective of improving the abrasion resistance of the rubber composition, it is preferably 25 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less. If the content of liquid rubber is too high, the rubber composition becomes soft and its abrasion resistance decreases. By keeping the content of liquid rubber within this range, the hardness of the rubber composition when made into a vulcanizate increases, tending to improve abrasion resistance.

[0288] The rubber composition can be prepared by mixing the hydrogenated diene polymer of this embodiment, other diene rubbers, silica-based inorganic fillers, and, if necessary, additives such as carbon black, other fillers, silane coupling agents, and rubber softeners.

[0289] Methods for preparing rubber compositions include, but are not limited to, melt mixing methods using common mixers such as open mills, Banbury mixers, kneaders, single-screw extruders, twin-screw extruders, and multi-screw extruders; and methods for dissolving and mixing the components and then heating to remove the solvent.

[0290] Among these, melt mixing methods based on rollers, Banbury mixers, kneaders, and extruders are preferred in terms of productivity and good mixability. Alternatively, methods that involve mixing the rubber component with other fillers, silane coupling agents, and additives in a single step, or methods that involve mixing in multiple stages, can also be used.

[0291] The rubber composition of this embodiment can be used to prepare a vulcanized composition that has undergone vulcanization treatment using a vulcanizing agent. Examples of vulcanizing agents include, but are not limited to, free radical initiators such as organic peroxides and azo compounds, oxime compounds, nitroso compounds, polyamine compounds, sulfur, and sulfur-containing compounds. Sulfur-containing compounds include sulfur monochloride, sulfur dichloride, disulfide compounds, and high-molecular-weight polysulfide compounds.

[0292] In the rubber composition of this embodiment, the content of the vulcanizing agent is preferably 0.01 parts by mass or more and 20 parts by mass or less, more preferably 0.1 parts by mass or more and 15 parts by mass or less, relative to 100 parts by mass of the rubber component. As the vulcanization method, a known method can be used, and the vulcanization temperature is preferably 120°C or more and 200°C or less, more preferably 140°C or more and 180°C or less.

[0293] Vulcanization accelerators can be used as needed during vulcanization.

[0294] As a vulcanization accelerator, existing known materials can be used, including but not limited to sulfenamide, guanidine, thiuram, aldehyde-amine, aldehyde-amine, thiazole, thiourea, and dithiocarbamate vulcanization accelerators.

[0295] In addition, examples of vulcanizing aids include, but are not limited to, zinc white and stearic acid.

[0296] The content of the vulcanization accelerator is preferably 0.01 parts by mass or more and 20 parts by mass or less, more preferably 0.1 parts by mass or more and 15 parts by mass or less, relative to 100 parts by mass of the rubber component containing the hydrogenated diene polymer of this embodiment.

[0297] In the rubber composition of this embodiment, other softeners and fillers, heat stabilizers, antistatic agents, weather stabilizers, anti-aging agents, colorants, lubricants and other additives other than those mentioned above may be used within the scope that does not impair the purpose of this embodiment.

[0298] Other softening agents may be used as known softening agents. Other fillers are not particularly limited; examples include calcium carbonate, magnesium carbonate, aluminum sulfate, and barium sulfate. Known materials may be used as the aforementioned heat stabilizers, antistatic agents, weather stabilizers, anti-aging agents, colorants, and lubricants.

[0299] [tire]

[0300] The rubber composition of this embodiment is suitable for use as a rubber composition for tires. That is, the tire of this embodiment is a molded body of the rubber composition.

[0301] As a tire rubber composition, it can be applied to various parts of tires, including but not limited to the tread, carcass, sidewall, and bead of various tires such as fuel-efficient tires, all-season tires, high-performance tires, and studless tires. In particular, the tire rubber composition exhibits excellent balance between abrasion resistance, breaking strength, low hysteresis loss, and wet skid resistance after being vulcanized, making it suitable for use in the tread of fuel-efficient and high-performance tires.

[0302] Example

[0303] The following specific embodiments and comparative examples are provided to further illustrate this implementation in detail, but the present invention is not limited to the following embodiments and comparative examples.

[0304] The various physical properties in the examples and comparative examples were determined by the methods shown below.

[0305] [Methods for determining physical properties]

[0306] (Weight-average molecular weight (Mw) of hydrogenated diene polymers)

[0307] The hydrogenated diene polymers prepared in the examples and comparative examples described later were used as samples for determination. The chromatograms were measured using a GPC assay apparatus connected to three columns packed with polystyrene gel. The weight-average molecular weight (Mw) was determined based on the calibration curve using standard polystyrene.

[0308] The specific measurement conditions are as follows.

[0309] Inject 20 μL of the following assay solution into the GPC assay apparatus for measurement.

[0310] <Measurement Conditions>

[0311] Device: Trademark name "HLC-8320GPC" manufactured by Tosoh Corporation

[0312] Eluent: Tetrahydrofuran (THF) containing 5 mmol / L triethylamine.

[0313] Guard column: TSK guard column SuperH-H manufactured by Tosoh Corporation.

[0314] Separation column: It is made by connecting the products manufactured by Tosoh Corporation under the trade names "TSKgel SuperH5000", "TSKgel SuperH6000" and "TSKgel SuperH7000" in sequence.

[0315] Oven temperature: 40℃

[0316] Flow rate: 0.6 mL / min

[0317] Detector: RI detector (manufactured by Tosoh Corporation, trade name "HLC8020")

[0318] Assay solution: The assay solution is prepared by dissolving 10 mg of the sample in 20 mL of THF.

[0319] (Mounney viscosity of hydrogenated diene polymer and rubber composition)

[0320] The hydrogenated diene polymer and rubber compositions prepared in the examples and comparative examples described later were used as samples for testing. The Mooney viscosity was measured using a Mooney viscometer (trade name "VR1132" manufactured by Uejima Manufacturing Co., Ltd.) with an L-shaped rotor in accordance with ISO 289.

[0321] Specifically, the sample was first preheated at 100°C for 1 minute, then the rotor was rotated at 2 rpm, and the torque was measured after 4 minutes. This torque was taken as the Mooney viscosity (ML) at 100°C. (1+4) ).

[0322] (Modification rate of hydrogenated diene polymer)

[0323] Taking advantage of the column adsorption property of the modified hydrogenated diene polymer, the modification rate of the hydrogenated diene polymer was determined by column adsorption GPC method as follows.

[0324] The amount of adsorption on the silica column is determined by comparing the chromatogram obtained from measuring a sample solution containing the test sample and a low molecular weight internal standard polystyrene using a column filled with polystyrene gel with the chromatogram obtained using a column filled with silica gel. The modification rate is then calculated.

[0325] The GPC determination conditions using polystyrene columns are shown below.

[0326] Inject 20 μL of the following assay solution into the GPC assay apparatus for measurement.

[0327] <GPC Determination Conditions Using Polystyrene Columns>

[0328] Device: Trademark name "HLC-8320GPC" manufactured by Tosoh Corporation

[0329] Eluent: THF containing 5 mmol / L triethylamine was added.

[0330] Guard column: Manufactured by Tosoh Corporation, product name "TSK guard column SuperH-H"

[0331] Pillar: Composed by sequentially linking the product names "TSKgel SuperH5000", "TSKgel SuperH6000", and "TSKgel SuperH7000" manufactured by Tosoh Corporation.

[0332] Oven temperature: 40℃

[0333] Flow rate: 0.6 mL / min

[0334] Detector: RI detector (HLC8020 manufactured by Tosoh Corporation)

[0335] Test solution: Dissolve 10 mg of the sample and 5 mg of standard polystyrene in 20 mL of THF to prepare the sample solution.

[0336] The GPC determination conditions using silica-based columns are shown below.

[0337] Inject 50 μL of the following assay solution into the GPC assay apparatus for measurement.

[0338] <GPC Determination Conditions Using Silica-Based Columns>

[0339] Device: Trademark name "HLC-8320GPC" manufactured by Tosoh Corporation

[0340] Elution buffer: THF

[0341] Protective pillar: Manufactured by GL Sciences under the trade name "DIOL 4.6×12.5mm 5micron"

[0342] Separation column: Consists of Agilent Technologies' trade names "Zorbax PSM-1000S", "PSM-300S", and "PSM-60S" linked together in sequence.

[0343] Oven temperature: 40℃

[0344] Flow rate: 0.5 mL / min

[0345] Detector: RI detector (HLC8020 manufactured by Tosoh Corporation)

[0346] The modification rate is calculated as follows: When using a polystyrene column, the peak area of ​​the chromatogram is set to 100, the peak area of ​​the sample is set to P1, and the peak area of ​​the standard polystyrene is set to P2. When using a silica column, the peak area of ​​the chromatogram is set to 100, the peak area of ​​the sample is set to P3, and the peak area of ​​the standard polystyrene is set to P4. The modification rate (%) is then calculated using the following formula.

[0347] Modification rate (%) = [1 - (P2 × P3) / (P1 × P4)] × 100

[0348] (Where, P1 + P2 = P3 + P4 = 100)

[0349] (Hydrogenation rate of the hydrogenated diene polymer, mathematical formula (S), mathematical formula (X) obtained by a to d as the composition ratio (mol%) of the structural units represented by the above formulas (1) to (4), and amount of bonded styrene)

[0350] pass 1 The integral values ​​of the unsaturated bonds in the diene polymer before hydrogenation were obtained by H-NMR determination.

[0351] Next, a large amount of methanol is added to the reaction solution after hydrogenation to precipitate the hydrogenated diene polymer for recovery.

[0352] Next, the hydrogenated diene polymer was extracted with acetone and then vacuum dried.

[0353] Use it as 1The composition ratios a to d (mol%) of the structural units represented by the above formula (1), the above formula (2), the above formula (3), and the above formula (4) of the sample were determined by H-NMR. The hydrogen conversion rate (hydrogen transformation rate) (hereinafter referred to as "hydrogen conversion rate") of the double bonds of the structural units from 1,3-butadiene, the above mathematical formula (S), and the amount of bonded styrene were determined. 1 The conditions for H-NMR measurement are as follows.

[0354] <Measurement Conditions>

[0355] Measuring instrument: JNM-LA400 (manufactured by JEOL)

[0356] Solvent: Deuterated chloroform

[0357] Test samples: Extracts of the polymer before and after hydrogenation.

[0358] Sample concentration: 50 mg / mL

[0359] Observation frequency: 400MHz

[0360] Chemical shift reference: TMS (tetramethylsilane)

[0361] Pulse delay: 2.904 seconds

[0362] Number of scans: 64

[0363] Pulse width: 45°

[0364] Measurement temperature: 26℃

[0365] (Degree of branching (Bn) of hydrogenated diene polymer)

[0366] The hydrogenated diene polymers prepared in the examples and comparative examples described below were used as samples, and the degree of branching (Bn) was determined by the GPC-light scattering method with a viscosity detector as follows.

[0367] Using a gel permeation chromatography (GPC) apparatus (trade name "GPCmax VE-2001" manufactured by Malvern) with three columns packed with polystyrene-based gel, the absolute molecular weight of the sample was determined by three detectors connected in the order of light scattering detector, differential refractive index (RI) detector, and viscosity detector (trade name "TDA305" manufactured by Malvern). The intrinsic viscosity of the sample was determined by the results from the RI detector and the viscosity detector.

[0368] The linear polymer conforms to the intrinsic viscosity [η] = -3.883 M. 0.771The material is used to calculate the shrinkage factor (g'), which is the ratio of the intrinsic viscosity corresponding to each molecular weight. It should be noted that in this formula, M represents the absolute molecular weight.

[0369] Subsequently, the degree of branching (Bn), defined as g' = 6Bn / {(Bn+1)(Bn+2)}, was calculated using the obtained shrinkage factor (g').

[0370] The eluent used was tetrahydrofuran (hereinafter also referred to as "THF") containing 5 mmol / L triethylamine.

[0371] Regarding the column, use the product names "TSKgel G4000HXL", "TSKgel G5000HXL" and "TSKgel G6000HXL" manufactured by Tosoh Corporation.

[0372] 20 mg of the sample to be tested was dissolved in 10 mL of THF to prepare the test solution. 100 μL of the test solution was injected into the GPC test apparatus and the test was performed at an oven temperature of 40 °C and a THF flow rate of 1 mL / min.

[0373] (Al content of hydrogenated diene polymer)

[0374] The aluminum content (Al content, in ppm) of the hydrogenated diene polymers prepared in the examples and comparative examples described below was determined by elemental analysis using inductively coupled plasma (ICP, manufactured by Shimadzu Corporation, device name: ICPS-7500).

[0375] [Methods for evaluating characteristics]

[0376] (Evaluation 1: Changes in Mooney viscosity of hydrogenated diene polymers over time)

[0377] The Mooney viscosity of the hydrogenated diene polymers prepared in the examples and comparative examples described below was measured under the following conditions.

[0378] The Mooney viscosity was determined using a Mooney viscometer (trade name "VR1132" manufactured by Uejima Seisakusho Co., Ltd.) according to ISO 289, using an L-shaped rotor.

[0379] Assume the measurement temperature is 100℃.

[0380] First, the sample was preheated at the test temperature for 1 minute. Then, the rotor was rotated at 2 rpm, and the torque was measured after 4 minutes. This torque was taken as the Mooney viscosity (ML). (1+4) ).

[0381] The Mooney viscosity measured within 4 hours after the hydrogenated diene polymer is manufactured is compared with the Mooney viscosity after being stored at 25°C and 30% humidity for 1 month, and the difference is used as ΔML for evaluation.

[0382] ΔML is recorded as 〇 when it is 0 or more but less than 8, and as × when it is 8 or more.

[0383] When ΔML is less than 8, it is considered good in practical applications.

[0384] (Rating 2: Cold Current)

[0385] A molded body measuring 40 mm × 40 mm × 50 mm thickness (H0) was prepared using the hydrogenated diene polymer described in the examples and comparative examples described later, and this body was used as the test specimen. A load of 1 kg was applied to the test specimen at 25°C, and the specimen was left to stand for 60 minutes. The thickness (H60) was then measured. The rate of change (%) of the thickness was calculated using the following formula.

[0386] Thickness change rate (%) = (H0 - H60) × 100 / H0

[0387] Let the rate of change of thickness represent the value of cold flow, and exponentialize the result of Example 1 as 100.

[0388] The smaller the index, the smaller the cold flow during storage, which is considered an excellent performance.

[0389] An index of 80 or above but below 89 is considered good (◎ in the table), 90 or above but below 99 is considered practically problem-free (〇 in the table), 100 or above but below 105 is considered slightly poor (Δ in the table), and above 105 is considered practically problem-free (× in the table).

[0390] (Evaluation 3: Molding properties of the glue block)

[0391] Using 35 kg of the hydrogenated diene polymer prepared in the examples and comparative examples described later, a rubber block was formed at a molding pressure of 10 MPa and a molding temperature of 80°C.

[0392] Based on the size of the compressed and released rubber block, the moldability of the rubber block is determined according to the following procedure.

[0393] 〇: The volume of the glue block is 40000 cm³ 3 Above and less than 50000cm 3 .

[0394] Δ: The volume of the glue block is 50000 cm³. 3 Above and less than 55000cm 3 .

[0395] ×: The volume of the glue block is 55000 cm³. 3 above.

[0396] For a rubber block formed under specified molding temperature and molding pressure, if its dimensions do not easily change before and after the pressure is released, it is considered to have excellent moldability.

[0397] The rubber blocks are compressed to a size that allows a specified number to be contained in a transport container. Therefore, if they expand instead of being shaped to the specified size, the required number cannot be contained, potentially causing problems during transport. By shaping the rubber blocks to the desired size after compression, they can be contained in containers of the specified dimensions for transport, which is advantageous from a transportation cost perspective.

[0398] [Method for manufacturing hydrogenated diene polymers]

[0399] (Preparation of hydrogenation catalyst)

[0400] In the examples and comparative examples described later, the hydrogenation catalyst used in the preparation of the hydrogenated diene polymer was prepared by the following method.

[0401] <Manufacturing Example 1>

[0402] Two liters of dried and purified cyclohexane were added to a nitrogen-purified reaction vessel, in which 40 mmol of bis(n-5-cyclopentadiene)bis(p-tolyl)titanium and 150 g of 1,2-polybutadiene (1,2-vinyl bond content approximately 85%) with a molecular weight of approximately 1000 were dissolved. A cyclohexane solution containing 60 mmol of n-butyllithium was then added to the reaction vessel, and the reaction was carried out at room temperature for 5 minutes. Immediately afterwards, 40 mmol of n-butanol was added, and the mixture was stirred to obtain the hydrogenation catalyst (TC-1). The obtained hydrogenation catalyst (TC-1) was stored at room temperature.

[0403] <Manufacturing Example 2>

[0404] One liter of dried and purified cyclohexane was added to a nitrogen-purified reaction vessel, along with 100 mmol of bis(n-5-cyclopentadiene)titanium dichloride. While stirring thoroughly, a hexane solution containing 200 mmol of trimethylaluminum was added, and the reaction was carried out at room temperature for approximately 3 days to obtain the hydrogenation catalyst (TC-2). The obtained hydrogenation catalyst (TC-2) was stored at room temperature.

[0405] (Polymerization of hydrogenated diene polymers)

[0406] <(Example 1) Hydrogenated diene polymer (sample A)>

[0407] A 40L autoclave equipped with a stirrer and jacket and capable of temperature control was used as the reactor. 2700g of 1,3-butadiene and 21000g of cyclohexane, which had been pre-removed of impurities, were added to the reactor, and the internal temperature of the reactor was maintained at 46°C.

[0408] As a polymerization initiator, 6.0 mmol of n-butyllithium was supplied to the reactor described above.

[0409] After the polymerization reaction began, the temperature inside the reactor started to rise due to the exothermic reaction, eventually reaching 76°C. Two minutes after reaching this peak temperature, 1.5 mmol of 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silazopentane (compound 1) was added to the reactor, and a coupling reaction was carried out for 20 minutes. 1.2 mmol of methanol was then added to the polymer solution as a reaction terminator to obtain a diene polymer solution.

[0410] The prepared hydrogenation catalyst (TC-1) was further added to the obtained diene polymer solution at a concentration of 50 ppm relative to 100 parts by mass of the diene polymer (based on Ti). The hydrogenation reaction was carried out for 1 hour at a hydrogen pressure of 0.8 MPa and an average temperature of 85 °C to obtain a hydrogenated diene polymer solution.

[0411] 12.6 g of octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid and 3.0 g of 4,6-bis(octylthiomethyl)-o-cresol were added as antioxidants to the solution of the obtained hydrogenated diene polymer. The solvent was then removed by stripping, and the polymer was dried using a dryer to obtain the hydrogenated diene polymer (sample A). The results of the analysis of sample A are shown in Table 1.

[0412] <(Example 2) Hydrogenated diene polymer (Sample B)>

[0413] Except that the amount of hydrogenation catalyst (TC-1) added was changed to 75 ppm, the process was carried out in the same manner as in Example 1 to obtain hydrogenated diene polymer (sample B).

[0414] The results of the analysis of sample B are shown in Table 1.

[0415] <(Example 3) Hydrogenated diene polymer (sample C)>

[0416] Except for changing the amount of hydrogenation catalyst (TC-1) added to 90 ppm, the process was carried out in the same manner as in Example 1 to obtain hydrogenated diene polymer (sample C).

[0417] The results of the analysis of sample C are shown in Table 1.

[0418] <(Example 4) Hydrogenated diene polymer (sample D)>

[0419] After adding 1,3-butadiene and cyclohexane to the reactor, 2.0 mmol of tetrahydrofuran (THF) and 4.0 mmol of 2,2-bis(2-tetrahydrofuranyl)propane (BOP) as polar compounds were added to the reactor, and the process was otherwise carried out in the same manner as in Example 2 to obtain a hydrogenated diene polymer (sample D). The results of the analysis of sample D are shown in Table 1.

[0420] <(Example 5) Hydrogenated diene polymer (sample E)>

[0421] After adding 1,3-butadiene and cyclohexane to the reactor, 3.0 mmol of tetrahydrofuran (THF) and 5.0 mmol of 2,2-bis(2-tetrahydrofuranyl)propane (BOP) as polar compounds were added to the reactor, and the process was otherwise carried out in the same manner as in Example 2 to obtain a hydrogenated diene polymer (sample E). The results of the analysis of sample E are shown in Table 1.

[0422] <(Example 6) Hydrogenated diene polymer (sample F)>

[0423] The 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silazane (compound 1) was replaced with tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (compound 2), and the addition amount was changed to 1.0 mmol. All other procedures were performed in the same manner as in Example 2 to obtain the hydrogenated diene polymer (sample F). The results of the analysis of sample F are shown in Table 1.

[0424] <(Example 7) Hydrogenated diene polymer (sample G)>

[0425] The 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silazane (compound 1) was replaced with bis(diethoxymethylsilylpropyl)-N-methylamine (compound 4), and the addition amount was changed to 3.0 mmol. Otherwise, the procedure was the same as in Example 2, yielding the hydrogenated diene polymer (sample G). The results of the analysis of sample G are shown in Table 1.

[0426] <(Example 8) Hydrogenated diene polymer (sample H)>

[0427] The 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silazopentanane (compound 1) was replaced with tetraethoxysilane (compound 5), and the process was otherwise the same as in Example 2, to obtain the hydrogenated diene polymer (sample H). The results of the analysis of sample H are shown in Table 1.

[0428] <(Example 9) Hydrogenated diene polymer (Sample I)>

[0429] The amount of 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silazane (compound 1) added was changed to 1.2 mmol, and the same procedure as in Example 2 was followed to obtain the hydrogenated diene polymer (sample I). The results of the analysis of sample I are shown in Table 1.

[0430] <(Example 10) Hydrogenated diene polymer (sample J)>

[0431] The amount of 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silazane (compound 1) added was changed to 0.8 mmol, and the same procedure as in Example 2 was followed to obtain the hydrogenated diene polymer (sample J). The results of the analysis of sample J are shown in Table 1.

[0432] <(Example 11) Hydrogenated diene polymer (sample K)>

[0433] The hydrogenation catalyst was changed to the one prepared above (TC-2), and the process was otherwise the same as in Example 2 to obtain the hydrogenated diene polymer (sample K). The results of the analysis of sample K are shown in Table 1.

[0434] <(Example 12) Hydrogenated diene polymer (sample L)>

[0435] The amount of n-butyllithium added was 12.0 mmol, the amount of 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silazane (compound 1) added was changed to 3.0 mmol, and the amount of ethanol added as a reaction terminator was changed to 2.2 mmol. All other procedures were performed in the same manner as in Example 2 to obtain the hydrogenated diene polymer (sample L). The results of the analysis of sample L are shown in Table 1.

[0436] <(Example 13) Hydrogenated diene polymer (sample M)>

[0437] The amount of n-butyllithium added was 3.0 mmol, the amount of 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silazopentane (compound 1) added was changed to 0.7 mmol, and the amount of ethanol added as a reaction terminator was changed to 0.5 mmol. All other procedures were performed in the same manner as in Example 2 to obtain the hydrogenated diene polymer (sample M). The results of the analysis of sample M are shown in Table 1.

[0438] <(Example 40) Hydrogenated diene polymer (sample T)>

[0439] The amount of 2,2-bis(2-tetrahydrofuranyl)propane (BOP) added was changed to 5.0 mmol, and the amount of hydrogenation catalyst (TC-1) added was changed to 90 ppm. Otherwise, the same procedure as in Example 4 was followed to obtain the hydrogenated diene polymer (sample T). The results of the analysis of sample T are shown in Table 2.

[0440] <(Example 41) Hydrogenated diene polymer (sample U)>

[0441] The tetrahydrofuran (THF) was changed to 3.0 mmol, and the amount of 2,2-bis(2-tetrahydrofuranyl)propane (BOP) was changed to 5.0 mmol, otherwise the same procedure as in Example 4 was performed to obtain the hydrogenated diene polymer (sample U). The results of the analysis of sample U are shown in Table 2.

[0442] <(Example 42) Hydrogenated diene polymer (sample V)>

[0443] In the hydrogenation process, the hydrogenation reaction was carried out for 1 hour at a hydrogen pressure of 0.8 MPa and an average temperature of 85°C, with the amount of hydrogen added varying. Otherwise, the process was the same as in Example 40, yielding a hydrogenated diene polymer (sample V). The results of the analysis of sample V are shown in Table 2.

[0444] <(Example 43) Hydrogenated diene polymer (sample W)>

[0445] In the hydrogenation process, the hydrogenation reaction was carried out for 1 hour at a hydrogen pressure of 0.8 MPa and an average temperature of 85°C, with the amount of hydrogen added varying. Otherwise, the process was the same as in Example 40, yielding a hydrogenated diene polymer (sample W). The results of the analysis of sample W are shown in Table 2.

[0446] <(Example 44) Hydrogenated diene polymer (sample X)>

[0447] The tetrahydrofuran (THF) was changed to 3.5 mmol, and the amount of 2,2-bis(2-tetrahydrofuranyl)propane (BOP) was changed to 6.0 mmol, otherwise the procedure was the same as in Example 40, to obtain the hydrogenated diene polymer (sample X). The results of the analysis of sample X are shown in Table 2.

[0448] <(Example 45) Hydrogenated diene polymer (sample Y)>

[0449] Except that the amount of hydrogenation catalyst (TC-1) added was changed to 75 ppm, the procedure was the same as in Example 44 to obtain the hydrogenated diene polymer (sample Y). The results of the analysis of sample Y are shown in Table 2.

[0450] <(Comparative Example 1) Hydrogenated diene polymer (sample N)>

[0451] Except that the amount of hydrogenation catalyst (TC-1) added was changed to 120 ppm, the procedure was the same as in Example 1 to obtain the hydrogenated diene polymer (sample N). The results of the analysis of sample N are shown in Table 2.

[0452] <(Comparative Example 2) Hydrogenated diene polymer (sample 0)>

[0453] Except that the amount of hydrogenation catalyst (TC-1) added was changed to 40 ppm, the procedure was the same as in Example 1 to obtain the hydrogenated diene polymer (sample O). The results of the analysis of sample O are shown in Table 2.

[0454] <(Comparative Example 3) Hydrogenated diene polymer (sample P)>

[0455] After adding 1,3-butadiene and cyclohexane to the reactor, 5.0 mmol of tetrahydrofuran (THF) and 7.0 mmol of 2,2-bis(2-tetrahydrofuranyl)propane (BOP) as polar compounds were added to the reactor, and the process was otherwise carried out in the same manner as in Example 2 to obtain the hydrogenated diene polymer (sample P). The results of the analysis of sample P are shown in Table 2.

[0456] <(Comparative Example 4) Hydrogenated diene polymer (sample Q)>

[0457] The 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silazane (compound 1) was replaced with [N,N-bis(trimethylsilyl)aminopropyl]methyldiethoxysilane (compound 3), and the addition amount was changed to 3.0 mmol. All other procedures were the same as in Example 2, yielding a hydrogenated diene polymer (sample Q). The results of the analysis of sample Q are shown in Table 2.

[0458] <(Comparative Example 5) Hydrogenated diene polymer (sample R)>

[0459] The hydrogenation catalyst was changed to the (TC-2) prepared above, and 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silazane (compound 1) was changed to [N,N-bis(trimethylsilyl)aminopropyl]methyldiethoxysilane (compound 3). The addition amount was changed to 3.0 mmol. Otherwise, the procedure was the same as in Example 2 to obtain the hydrogenated diene polymer (sample R). The results of the analysis of sample R are shown in Table 2.

[0460] <(Comparative Example 6) Hydrogenated Diene Polymer (Sample S)>

[0461] A 40L autoclave equipped with a stirrer and jacket, and capable of temperature control, was used as the reactor. 2160g of 1,3-butadiene, 300g of styrene, and 21000g of cyclohexane (pre-removed impurities) were added to the reactor. 30mmol of tetrahydrofuran (THF), a polar compound, and 4.9mmol of 2,2-bis(2-tetrahydrofuranyl)propane were also added. The reactor temperature was maintained at 42°C. 33.2mmol of n-butyllithium was supplied to the reactor as a polymerization initiator.

[0462] After the polymerization reaction began, the temperature inside the reactor started to rise due to the exothermic reaction, eventually reaching 76°C. Two minutes after reaching this peak temperature, 6.6 mmol of 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silazopentane (compound 1) was added to the reactor, and a coupling reaction was carried out for 20 minutes.

[0463] Adding 6.0 mmol of methanol as a reaction terminator to the polymer solution yields a diene polymer solution.

[0464] The prepared hydrogenation catalyst (TC-1) was further added to the obtained diene polymer solution at a concentration of 50 ppm relative to 100 parts by mass of the diene polymer (based on Ti). The hydrogenation reaction was carried out for 1 hour at a hydrogen pressure of 0.8 MPa and an average temperature of 85 °C to obtain a hydrogenated diene polymer solution.

[0465] 12.6 g of octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid as an antioxidant and 3.0 g of 4,6-bis(octylthiomethyl)-o-cresol were added to the solution of the obtained hydrogenated diene polymer. The solvent was then removed by stripping, and the polymer was dried using a dryer to obtain the hydrogenated conjugated diene polymer (sample S). The results of the analysis of sample S are shown in Table 2.

[0466]

[0467]

[0468] [Preparation of Rubber Compositions]

[0469] (Examples 14-39, 46-51, Comparative Examples 7-16)

[0470] Rubber compositions were prepared using the above-mentioned hydrogenated diene polymers or hydrogenated diene-based polymers (samples A to P), high cis polybutadiene (BR, "UBEPOL U150" manufactured by Ube Industries), natural rubber (NR), and styrene-butadiene rubber (SBR, Y031 manufactured by Asahi Kasei Corporation) as rubber components, according to the proportions shown in Tables 3 to 6 and the conditions shown below.

[0471] The trade names used for each ingredient in Tables 3 to 6 are as follows.

[0472] • Silica (manufactured by Evonik Degussa, trade name "Ultrasil 7000GR") has a nitrogen adsorption specific surface area of ​​170 m². 2 / g)

[0473] • Carbon black (manufactured by Tokai Carbon Co., Ltd., trade name "SEAST KH(N339)")

[0474] • S-RAE oil (trade name "Process NC140" manufactured by JX Nippon Oil & Gas Co., Ltd.)

[0475] • Liquid rubber (trade name "Kuraprene LBR-302" manufactured by KURARAY, molecular weight 5500)

[0476] • Silane coupling agent (trade name "Si75", bis(triethoxysilylpropyl) disulfide, manufactured by Evonik Degussa)

[0477] Anti-aging agent (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine)

[0478] • Vulcanization accelerator 1 (N-cyclohexyl-2-benzothiazole sulfinamide)

[0479] • Vulcanization accelerator 2 (diphenylguanidine)

[0480] The above materials are mixed by the following method to obtain a rubber composition.

[0481] Using a closed mixing mill (0.3L capacity) equipped with a temperature control device as the first stage of mixing, the rubber components (hydrogenated diene polymer, hydrogenated diene polymer, high cis polybutadiene, natural rubber and styrene-butadiene rubber), fillers (silica, carbon black), silane coupling agent, S-RAE oil, liquid rubber, zinc white and stearic acid are mixed under the conditions of 60% filling rate and rotor speed of 30-50 rpm.

[0482] At this point, the temperature of the closed mixer is controlled, and each rubber composition (mixture) is obtained at a discharge temperature of 155-160°C.

[0483] Next, as the second stage of mixing, the mixture obtained above is cooled to room temperature, and an anti-aging agent is added. In order to improve the dispersibility of the filler, the mixture is mixed again.

[0484] In this case, the discharge temperature of the mixture is also adjusted to 155-160°C by controlling the temperature of the mixer.

[0485] After cooling, as the third stage of mixing, sulfur and vulcanization accelerators 1 and 2 are added to an open mill set at 70°C and mixed. Then, molding is performed, and vulcanization is carried out at 160°C using a vulcanization press for 25 minutes.

[0486] The properties of the rubber composition before and after vulcanization were evaluated.

[0487] Specifically, the evaluation was conducted using the methods described below. The results are shown in Tables 3 to 6.

[0488] (Evaluation of physical properties)

[0489] <(Evaluation 4) Processability: Mooney viscosity of the mixture>

[0490] The mixture obtained above after the second stage of mixing and before the third stage of mixing was used as a sample. Using a Mooney viscometer, according to JIS K6300-1, after preheating at 130°C for 1 minute, the rotor was rotated at 2 revolutions per minute for 4 minutes, and then the viscosity was measured.

[0491] The result of Comparative Example 8 is set to 100 and then exponentialized.

[0492] The smaller the index, the better the processability.

[0493] <(Evaluation 5) Fracture Strength>

[0494] The breaking strength was determined according to the tensile test method of JIS K6251.

[0495] The result of Comparative Example 8 was set to 100 and exponentialized. The larger the exponent, the better the fracture strength.

[0496] <(Evaluation 6) Abrasion Resistance>

[0497] The wear was measured using an Akron abrasion tester (manufactured by Yasuda Seiki Co., Ltd.) according to JIS K6264-2 at a load of 44.4 N and 1000 rpm.

[0498] The result of Comparative Example 8 was set to 100 and indexed. The smaller the index, the better the wear resistance.

[0499] <(Evaluation 7 and 8) Low-temperature performance and low fuel consumption: viscoelastic parameters>

[0500] Viscoelastic parameters were determined using an ARES viscoelastic testing machine manufactured by Rheometric Scientific in torsional vibration mode. The results of the rubber composition of Comparative Example 8 were set to 100, and the measured values ​​were indexed.

[0501] The tanδ value, measured at 50℃, 10Hz, and 3% strain, is used as an indicator of low fuel consumption. The smaller the index, the better the fuel consumption.

[0502] The storage modulus (G'), measured at -20℃ under conditions of 10Hz frequency and 1% strain, is used as an indicator of low-temperature performance. The smaller the index, the better the low-temperature performance.

[0503]

[0504]

[0505]

[0506]

[0507] As shown in Tables 4 to 6, compared with Comparative Examples 7 to 16, Examples 14 to 39 and 46 to 51 confirmed that the rubber compositions had excellent low-temperature performance and abrasion resistance, as well as excellent breaking strength.

[0508] This application is based on Japanese Patent Application No. 2020-203168, filed with the Japan Patent Office on December 8, 2020, the contents of which are incorporated herein by reference.

[0509] Industrial applicability

[0510] The rubber composition of the present invention has industrial applicability in the fields of tire treads, automotive interior and exterior parts, vibration damping rubber, belts, footwear, foams, and various industrial products.

Claims

1. A hydrogenated diene polymer, wherein, The degree of branching (Bn) determined by GPC-light scattering with a viscosity detector is greater than 1.

5. When the composition ratios (in mol%) of the structural units represented by equation (1), equation (2), equation (3), and equation (4) are respectively set as a, b, c, and d, the following mathematical expression (S) is satisfied. The hydrogenation rate is 40%–85%. The modification rate is over 70% by mass. The styrene content in the hydrogenated diene polymer is less than 0.1% by mass. The modification rate represents the mass ratio of the polymer with nitrogen-containing functional groups to the total amount of hydrogenated diene polymer. Mathematical expression (S): 10≦[(a+b) / (a+b+c+d)]×100≦70 [Chemistry 1] 。 2. The hydrogenated diene polymer as described in claim 1, wherein, The degree of branching (Bn) determined by GPC-light scattering with a viscosity detector is greater than 1.

5. Satisfying the following mathematical expression (S), The hydrogenation rate is 40%–80%. Mathematical expression (S): 10≦[(a+b) / (a+b+c+d)]×100≦60.

3. The hydrogenated diene polymer as described in claim 1 or 2, wherein, The following mathematical expression (X) is 2.0 or less. Mathematical expression (X): (a+c) / (a+b).

4. The hydrogenated diene polymer according to claim 3, wherein, The mathematical expression (X) is greater than 0.8 and less than 2.

0.

5. The hydrogenated diene polymer as described in claim 1 or 2, wherein, The hydrogenation rate is over 51%.

6. The hydrogenated diene polymer as described in claim 1 or 2, wherein, The hydrogenation rate is below 71%.

7. The hydrogenated diene polymer as described in claim 1 or 2, wherein it contains nitrogen atoms.

8. The hydrogenated diene polymer as claimed in claim 1 or 2, wherein, The aluminum content is less than 2 ppm.

9. The hydrogenated diene polymer as claimed in claim 1 or 2, wherein, The degree of branching (Bn) is below 84.

10. The hydrogenated diene polymer as claimed in claim 1 or 2, wherein, The mathematical formula (S) is: 15≦[(a+b) / (a+b+c+d)]×100≦60.

11. The hydrogenated diene polymer as claimed in claim 1 or 2, wherein, The mathematical formula (S) is: 20≦[(a+b) / (a+b+c+d)]×100≦60.

12. The hydrogenated diene polymer as claimed in claim 1 or 2, wherein, The mathematical formula (S) is: 20≦[(a+b) / (a+b+c+d)]×100≦50.

13. The hydrogenated diene polymer as claimed in claim 1 or 2, wherein, The mathematical formula (S) is: 20≦[(a+b) / (a+b+c+d)]×100≦40.

14. The hydrogenated diene polymer as claimed in claim 1 or 2, wherein, The hydrogenation rate is above 45%.

15. The hydrogenated diene polymer as claimed in claim 1 or 2, wherein, The hydrogenation rate is above 55%.

16. The hydrogenated diene polymer as claimed in claim 1 or 2, wherein, The hydrogenation rate is below 75%.

17. The hydrogenated diene polymer as claimed in claim 1 or 2, wherein, The hydrogenation rate is below 65%.

18. The hydrogenated diene polymer of claim 3, wherein, The mathematical expression (X) is 1.0 or higher.

19. The hydrogenated diene polymer as claimed in claim 1 or 2, wherein, The weight-average molecular weight is between 150,000 and 1,000,000.

20. The hydrogenated diene polymer as claimed in claim 1 or 2, wherein, The content of aromatic vinyl monomer units is less than 5% relative to the total mass of the hydrogenated diene polymer.

21. The hydrogenated diene polymer as claimed in claim 1 or 2, wherein, The content of aromatic vinyl monomer units is less than 0.1% by mass relative to the total mass of the hydrogenated diene polymer.

22. A rubber block, which is a molded body of the hydrogenated diene polymer according to any one of claims 1 to 21.

23. A rubber composition comprising: 100 parts by weight of a rubber component comprising 10 to 50 parts by weight of the hydrogenated diene polymer according to any one of claims 1 to 21, and 50 to 90 parts by weight of a diene-based rubber; and 20 to 100 parts by weight of silica-based inorganic filler.

24. The rubber composition of claim 23, wherein, 100 parts by weight of the rubber composition contain more than 20 parts by weight and less than 45 parts by weight of hydrogenated diene polymer.

25. The rubber composition of claim 23, wherein, It contains 50 to 90 parts by weight of silica-based inorganic filler.

26. The rubber composition of claim 23, wherein, The nitrogen adsorption specific surface area of ​​the silica-based inorganic filler, determined by the BET adsorption method, is 100 m². 2 / g or more 300m 2 / g or less.

27. The rubber composition of claim 23, comprising 2 to 25 parts by mass of liquid rubber.

28. A tire, which is a molded body of the rubber composition of claim 27.

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