Conjugated diene-based polymer and method for producing conjugated diene-based polymer

Description

1 / 122 “CONJUGATED DIENE-BASED POLYMER AND METHOD FOR PRODUCING CONJUGATED DIENE-BASED POLYMER” FIELD OF TECHNIQUE

[001] The present invention relates to a conjugated diene-based polymer and to a method for producing a conjugated diene-based polymer. Background of the technique

[002] One of the basic functions required of a vehicle tire tread is its braking property on the road. Due to climate change in recent years, road surfaces can become wet due to sudden rain, or they can become covered in ice and snow due to a sudden blizzard. In these environments, there is a demand for a rubber material to be used in a tire tread that has excellent braking properties, not only on dry road surfaces, but also on icy and snowy or wet road surfaces.

[003] In general, wet grip performance, which is a property of a rubber compound necessary for it to exhibit braking properties on a wet road surface, and low-temperature performance, which is a property of a rubber compound necessary for it to exhibit braking properties in snow, are contradictory, and improving one tends to cause deterioration in the other. A tire tread rubber compound is needed to resolve the contradiction between these properties.

[004] In addition, to improve performance at low temperatures, there is conventionally a known rubber compound whose modulus of elasticity is reduced at low temperatures to ensure high grip capacity of a tire on a snowy road surface, and a Petition 870250088330, dated 09 / 29 / 2025, page 7 / 139 2 / 122 technique for reducing the glass transition temperature of a rubber material to reduce the glass transition temperature of a rubber compound.

[005] On the other hand, there is a known method in which the glass transition temperature of a rubber compound is increased to improve wet grip performance, and a technique for increasing the glass transition temperature of a rubber material to increase the glass transition temperature of a rubber compound has been proposed.

[006] For example, Patent Document 1 discloses a rubber composition containing a modified low-temperature glass transition conjugate diene-based polymer obtained by reacting an alkoxysilane with an amino group with an active end of a silica-conjugate diene-based polymer, and thus proposes a technique for improving low-temperature performance.

[007] Patent Document 2 discloses a rubber composition containing a diene-based polymer conjugated with a high glass transition temperature and silica and therefore proposes a technique for improving wet grip performance. List of citations Patent document Patent document 1: International publication no. WO2021 / 005295 Patent document 2: Japanese patent no. 3438317 Summary of the invention Problem of the technique

[008] All-weather tires, usable in all seasons, are considered to have become popular in Europe and elsewhere, and there is a demand for a rubber compound with improved wet grip performance in a Petition 870250088330, dated 09 / 29 / 2025, page 8 / 139 3 / 122 wide temperature range.

[009] However, when the present inventors examined in detail the conventional rubber compositions disclosed in Patent Documents 1 and 2, it was found that conventional rubber compositions have a problem: there is room for improvement in the balance between wet grip performance and low temperature performance of a vulcanized version thereof.

[0010] Specifically, a rubber compound containing a conjugated diene-based polymer must have unreduced flexibility at low temperatures and have excellent braking properties even on icy and snowy road surfaces, improving the wet grip performance of a vulcanized compound thereof.

[0011] Therefore, an objective of the present invention is to provide a conjugated diene-based polymer from which a tire with excellent grip performance on wet surfaces and at low temperatures can be obtained, and a method for producing the conjugated diene-based polymer. Solution to the problem

[0012] The present inventors have carried out serious studies to solve the problems described above, resulting in the finding that when a polymer with prescribed properties in relation to the glass transition temperature is used, a vulcanizate of the polymer can be good in both wet grip performance and low temperature performance and, therefore, the present invention was realized.

[0013] Specifically, the present invention provides the following: [1] A conjugated diene-based polymer, wherein an estimated glass transition temperature (estimated Tg) derived from Petition 870250088330, dated 09 / 29 / 2025, page 9 / 139 4 / 122 a microstructure of the conjugated diene-based polymer is -72°C or more and -45°C or less, the conjugated diene-based polymer has only one glass transition temperature (Tg) measured by differential scanning calorimetry (DSC), and a difference between an extrapolated initial temperature and an extrapolated final temperature of the glass transition temperature (Tg) is 15°C or more and 35°C or less. [2] The conjugated diene-based polymer according to [1], containing a first polymeric segment not containing an aromatic vinyl monomer unit and a second polymeric segment containing an aromatic vinyl monomer unit, wherein a vinyl linkage amount Yi (mol%) in the conjugated diene linked to the first polymeric segment satisfies the following expression (2): < Yi < 45 ... (2) an estimated glass transition temperature (estimated Tg) derived from a microstructure of the second polymer segment is greater than -45°C and -5°C or less. [3] The conjugated diene-based polymer according to [1] or [2], wherein a molecular weight distribution corresponding to a ratio Mw / Mn between a weight-average molecular weight Mw and a number-average molecular weight Mn is 1.7 or more and 2.5 or less. [4] The diene-based conjugated polymer according to [2] or [3], wherein a segment ratio of the first polymer segment is 20% by mass or more and 80% by mass or less. [5] The diene-based conjugated polymer according to any one of [1] to [4], having a weight-average molecular weight of 300,000 or more and 1,350,000 or less. [6] The diene-based polymer conjugated according to any one of [1] to [5], containing a nitrogen atom. [7] The diene-based conjugate polymer according to [6], wherein a modification ratio of the diene-based polymer con- Petition 870250088330, dated 09 / 29 / 2025, page 10 / 139 5 / 122 judged is 70% or more. [8] A method for producing the conjugated diene-based polymer according to any one of [2] to [7], using two or more continuous reactors, wherein the method includes: a first polymerization step (P1) of continuous formation of the first polymeric segment of the conjugated diene-based polymer with a conjugated diene compound, a polymerization initiator and a polar material added to the continuous reactors; and a second polymerization step (P2) of formation of the second polymeric segment at one end of the first polymeric segment with an aromatic vinyl compound and a polar material added to the continuous reactors. [9] The method for producing the conjugated diene-based polymer according to [8], also including, after the second polymerization step (P2), a coupling step (P3) of reaction of a coupling agent with the conjugated diene-based polymer.

[10] The method for producing the conjugated diene-based polymer according to [8] or [9], wherein a mass ratio between the conjugated diene compound added in the first polymerization step (P1) and a total amount of the conjugated diene compound and the added aromatic vinyl compound is 20% by mass or more and 80% by mass or less.

[11] The method for producing the conjugated diene-based polymer according to any one of [8] to

[10] , wherein a polymerization reaction rate in the first polymerization step (P1) is 75% or more and 95% or less.

[12] The method for producing the conjugated diene-based polymer according to any one of [8] to

[11] , wherein a mass ratio between an amount of the added aromatic vinyl compound and an amount of the added conjugated diene compound Petition 870250088330, dated 09 / 29 / 2025, page 11 / 139 6 / 122 in the second polymerization stage (P2) is 0.15 or more and 0.70 or less.

[13] The method for producing the conjugated diene-based polymer according to any one of [8] to

[12] , wherein the polar material is added in the second polymerization step (P2) in a greater quantity than the quantity of polar material added in the first polymerization step (P1).

[14] The method for producing the conjugated diene-based polymer according to any one of [9] to

[13] , wherein the coupling agent is an aminoalkoxysilane compound. Advantageous effect of the invention

[0014] The present invention provides a conjugated diene-based polymer whose vulcanizate is excellent in both wet grip performance and low temperature performance. Description of the modalities

[0015] Now, one embodiment for carrying out the present invention (hereinafter referred to as the present embodiment) will be described in detail.

[0016] It should be noted that the following embodiment is merely an example to describe the present invention and is not intended to limit it to the content that follows. The present invention can be practiced with various modifications appropriately made within the scope thereof. Conjugated diene-based polymer

[0017] A conjugated diene-based polymer of the present embodiment contains a conjugated diene monomer unit and an aromatic vinyl monomer unit.

[0018] The conjugated diene-based polymer of the present embodiment has an estimated glass transition temperature derived from Petition 870250088330, dated 09 / 29 / 2025, page 12 / 139 7 / 122 a microstructure of the conjugated diene-based polymer (hereinafter sometimes referred to as estimated Tg) of -72°C or higher and -45°C or lower.

[0019] The estimated glass transition temperature (estimated Tg) is derived from a microstructure of the diene-based conjugated polymer, as described below.

[0020] The conjugated diene-based polymer of the present embodiment has only one glass transition temperature (Tg) measured by differential scanning calorimetry (DSC), and the difference between an extrapolated initial temperature and an extrapolated final temperature of the glass transition temperature (Tg) is 15°C or more and 35°C or less.

[0021] The configuration described above provides a conjugated diene-based polymer from which an excellent vulcanizate can be obtained in terms of both wet grip performance and low temperature performance. Conjugated diene compound

[0022] Examples of a conjugated diene compound forming the conjugated diene monomeric unit 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 point of view of industrial availability. One of them can be used individually, or two or more of them can be used together.

[0023] The conjugated diene compound is preferentially 1,3-butadiene or isoprene, and more preferably 1,3-butadiene from the point of view of availability and structure controllability in polymer synthesis. Aromatic vinyl compound

[0024] Examples of an aromatic vinylic compound that forms the Petition 870250088330, dated 09 / 29 / 2025, page 13 / 139 8 / 122 aromatic vinyl monomeric units include, but are not limited to, styrene, p-methylstyrene, α-methylstyrene, vinylethylbenzene, vinylxylene, vinylnaphthalene, and diphenylethylene. Among these, styrene is preferred from the point of view of industrial availability. One of them can be used individually, or two or more of them can be used together.

[0025] The aromatic vinyl compound is preferably styrene from the point of view of availability and structure controllability in polymer synthesis. Microstructure

[0026] Microstructure herein refers to a polymer composition, including the type of isomer, in the diene-based conjugated polymer using the aromatic vinyl compound and the diene-conjugated compound, or in a polymer segment described below.

[0027] In the conjugated diene-based polymer of the present embodiment, the mass of a copolymer consisting of styrene and butadiene is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more relative to the mass of the entire conjugated diene-based polymer. Quantity of bound aromatic vinyl monomer unit (Xtotal)

[0028] The estimated Tg of the conjugated diene-based polymer of the present embodiment is derived from the microstructure of the conjugated diene-based polymer, and an example of the microstructure includes an amount of linked aromatic vinyl monomer unit (Xtotal).

[0029] The amount of linked aromatic vinyl monomer unit (Xtotal) (% by mass) herein refers to a mass fraction value of one linked aromatic vinyl monomer unit in the total mass of the conjugated diene-based polymer of the present Petition 870250088330, dated 09 / 29 / 2025, page 14 / 139 9 / 122 dalidade.

[0030] Here, the amount of the linked aromatic vinyl monomer unit can be calculated by measuring the ultraviolet absorption of a phenyl group contained in a derived portion of the aromatic vinyl compound of the conjugated diene-based polymer (hereinafter sometimes referred to as the linked aromatic vinyl monomer unit or aromatic vinyl monomer unit). When the conjugated diene-based polymer contains both the linked aromatic vinyl monomer unit and a linked conjugated diene monomer unit, the amount of the linked conjugated diene monomer unit can be obtained based on the amount of the linked aromatic vinyl monomer unit obtained as described above. Specifically, the amount can be measured by a method described in the examples below. Amount of vinyl bond (Ytotal) in the conjugated diene bonded

[0031] The estimated Tg of the conjugated diene-based polymer of the present embodiment is derived from the microstructure of the conjugated diene-based polymer, and an example of the microstructure includes a vinyl bond quantity (Ytotal) in the bonded conjugated diene.

[0032] The amount of vinyl linkage (Ytotal) (mol %) in the conjugated diene linkage refers here to a molar fraction (mol %) of a 1,2 linkage unit in a polymer unit derived from the conjugated diene compound contained in the conjugated diene-based polymer of the present embodiment.

[0033] When the conjugated diene-based polymer of the present embodiment is a butadiene-styrene copolymer, the amount of vinyl linkage in the conjugated diene can be obtained by determining the amount of vinyl linkage (1,2 linkage amount) in the butadiene linked by Hampton's method (RR Hampton, Analytical Petition 870250088330, dated 09 / 29 / 2025, p. 15 / 139 10 / 122 Chemistry, 21, 923 (1949)). Specifically, the quantity can be measured by a method described in the examples below. Content of the linked aromatic vinyl monomer unit block

[0034] The conjugated diene-based polymer of the present embodiment preferably contains few or no blocks in which 4 or more linked aromatic vinyl monomer units are chained (hereinafter sometimes referred to as the linked aromatic vinyl monomer unit block).

[0035] The conjugated diene-based polymer of the present embodiment contains few or no linked aromatic vinyl monomer block units and, therefore, tends to be unlikely to have two or more glass transition temperatures.

[0036] The block content of the linked aromatic vinyl monomer unit in the conjugated diene-based polymer can be measured, when the conjugated diene-based polymer is a butadiene-styrene polymer, using a known method in which the conjugated diene-based polymer is decomposed by the Kolthoff method (a method described by IM KOLTHOFF, et al., J. Polym. Sci. 1, 429 (1946)) to analyze the amount of polystyrene insoluble in methanol. The block content of the linked aromatic vinyl monomer unit measured by such method is preferably 1.0% by mass or less, and more preferably 0.1% by mass or less relative to the total amount of the conjugated diene-based polymer.When the block of the linked aromatic vinyl monomer unit is not contained in a conjugated diene copolymer and in the polymer segment described below, the conjugated diene-based polymer of the present embodiment tends to exhibit a consecutive property against temperature changes. As a result, a vulcanizate that uses the conjugated diene-based polymer of the present embodiment. Petition 870250088330, dated 09 / 29 / 2025, page 16 / 139 11 / 122 changes consecutively over a wide temperature range and tends to have excellent tensile strength. Method for estimating the glass transition temperature of the diene-based conjugated polymer: Estimated glass transition temperature (estimated Tg)

[0037] The glass transition temperature of the conjugated diene-based polymer of the present embodiment can be calculated by the Gordon Taylor formula expanded for two or more component series of the following expression (1) (Gordon, M., Taylor JSJ, Appl. Chem. 1952, 2, 493). A value calculated by this method is called the estimated glass transition temperature (estimated Tg). I it 1 n.) Estimated Tg = ------—---- ... ( 1 ) y / Δ (Tf VAT Pi '

[0038] In expression (1), a subscript i of each variable indicates each component of the microstructure contained in the conjugated diene-based polymer, Δα denotes a difference in the coefficient of thermal expansion of a homopolymer of component i caused by the glass transition, w denotes a mass ratio of component i in the conjugated diene-based polymer, Tg denotes the glass transition temperature of the homopolymer of component i, ep denotes the density of the homopolymer of component i. As these values, a document value or a measured value may be used. For example, when the conjugated diene-based polymer contains styrene, and one of the components i is a styrene component, Δα can be 3.6 χ ​​10-4K-1 based on the coefficient of thermal expansion of polystyrene (J. BRANDRUP et al., Polymer Handbook, 3rd edition, (USA), John Wiley & Sons, Inc., 1966, VI-75), Tg can be 105.3°C based on the measured value of the glass transition temperature, and pi can be 1.02 g / cm3 with Petition 870250088330, dated 09 / 29 / 2025, page 17 / 139 12 / 122 based on the measured density value.

[0039] For example, when the conjugated diene-based polymer is a butadiene-styrene copolymer, the estimated glass transition temperature (Tg estimated) can be calculated according to the following expression (i) using the amount of linked aromatic vinyl monomer unit Xtotai (% by mass), the amount of vinyl linkage Ytotai (% by mol) in the linked conjugated diene and the coefficient of thermal expansion (Aai), the glass transition temperature (Tg,), and the density (pi) of each of the following: polystyrene (PS), poly-1,2-butadiene (1,2-PBd) and poly-1,4-butadiene (1,4-PBd): Estimated Tg P(PS)P(PBd) P(PS) P(PBd) ^X37.2+ íl-^]x{(l-^)x(-57.5)+(^)x(-5.38)} 100 k 100 / Ά 100 / v______Jkioo / x______ / J#. · ( £ Í^XO.36+ (1-^)χ{( 1-^^(0.56)+(^^(0.46)} 100 k 100 / A 100? 'Jkl00 / / J -5750+94.7XXau + 52.12XraZZ-0.5212xXaUxyau 56—o.2x xaii-o.ixyaii+o.ooixxaiíxraíí• · (i) Legend: Xaii = Xtotai Yall=Ytotai

[0040] The influence, in the denominator of expression (i), of a product of the amount of linked aromatic vinyl monomer unit Xtotai (% by mass) and the amount of vinyl linkage Ytotai (% by mol) in the linked conjugated diene is very small and, therefore, the expression can be approximated to the following expression (ii). Furthermore, expression (ii) can be approximated to the following expression (iii). Estimated Tg = -5750 + 94.7 x XtQtai+ 52.12 xYtotaÍ-0.5212 x XtQtaÍxYtQtBÍ...(ÜJ - 0.2 x Χ,^ι-0.1 xYtotsi Estimated Tg = -5750 + 95 χΧΜΗί+ 52.12 x YtQtai- 0.52 x ΧμβιχΥ^ι — 0.2 X Xtotai— 0.1 X Ytotai

[0041] Specifically, when using a butadiene homopolymer, Petition 870250088330, dated 09 / 29 / 2025, p. 18 / 139 13 / 122 or a butadiene-styrene based copolymer, the physical property of the conjugated diene based polymer can be predicted according to expression (iii) based on a value normally used in design.

[0042] According to expression (1), a mass relationship between the microstructure components can be obtained based on the microstructure, such as the amount of linked aromatic vinyl monomer unit Xtotal (% by mass) in the conjugated diene-based polymer of the present embodiment and the amount of vinyl linkage Ytotal (% by mol) in the linked conjugated diene, and the glass transition temperature (Tg) of the conjugated diene-based polymer can be estimated. In other words, the estimated Tg is a standard that indicates the change in the glass transition temperature of the conjugated diene-based polymer in relation to the change in the amount of linked aromatic vinyl monomer unit Xtotal (% by mass) and the amount of vinyl linkage Ytotal (% by mol) in the linked conjugated diene.

[0043] When the estimated Tg has a small value, the glass transition temperature (Tg) of the conjugated diene-based polymer of the present embodiment is low, and when the estimated Tg has a large value, the glass transition temperature (Tg) of the conjugated diene-based polymer of the present embodiment is high.

[0044] For example, when the estimated Tg is -70, the glass transition temperature of the conjugated diene-based polymer is estimated to be -70°C, and when the estimated Tg is -45, the glass transition temperature of the conjugated diene-based polymer is estimated to be -45°C.

[0045] Thus, the estimated Tg value obtained based on the microstructure of the conjugated diene-based polymer is an index of the glass transition temperature of the conjugated diene-based polymer in general. The present inventors have found, however, that when the relaxation of a conjugated diene-based polymer in Petition 870250088330, dated 09 / 29 / 2025, page 19 / 139 14 / 122 In the vicinity of a measured glass transition temperature, the actual viscoelasticity of a vulcanizate does not always agree with the viscoelasticity based on the estimated glass transition temperature calculated from the microstructure. Specifically, when a difference in the estimated Tg value between the polymer segments described below is 33 or more, or the mass ratio of a first polymer segment described below is within a section of 40 to 60, the discrepancy between the estimated glass transition temperature based on expression (1) (estimated Tg) and a measured glass transition temperature (Tg) tends to be noticeable.Therefore, it was found that, from the point of view of controlling the performance of a vulcanizate affected by the glass transition temperature, it is more effective to control the estimated Tg value calculated based on the microstructure to a specific value than to control the measured glass transition temperature of the conjugated diene-based polymer to a specific value. This appears to occur because small energy changes are detected in the DSC (differential scanning calorimetry) measurement, and therefore the entire glass transition temperature is affected by the onset of relaxation of a low-Tg portion of the conjugated diene-based polymer, resulting in the measured glass transition temperature decreasing to a value lower than the estimated glass transition temperature.For example, it has been experimentally confirmed that in diene-based polymers conjugated with the same overall microstructure, the glass transition temperature measured by DSC can differ by approximately 2 to 5°C depending on the difference in the microstructure of each segment.

[0046] When the estimated Tg of the conjugated diene-based polymer of the present embodiment has a value in a numerical range of -72°C or more and -45°C or less, the glass transition temperature Petition 870250088330, dated 09 / 29 / 2025, page 20 / 139 15 / 122 measurement obtained in the form of a vulcanized product becomes an optimal value and, therefore, the balance between wet grip performance and low-temperature performance tends to be excellent.

[0047] In the conjugated diene-based polymer of the present embodiment, the lower limit of the estimated Tg derived from the microstructure is -72°C or more, preferably -70°C or more, and more preferably -68°C or more. When the lower limit of the estimated Tg falls within this range, the wet grip performance of a vulcanizate of the conjugated diene-based polymer of the present embodiment tends to be improved.

[0048] The upper limit of the estimated Tg is -45°C or less, preferably -48°C or less, and more preferably -50°C or less. When the upper limit of the estimated Tg falls within this range, the low-temperature performance of the vulcanizate of the conjugated diene-based polymer of the present embodiment tends to be improved.

[0049] The estimated Tg can be controlled to fall within the numerical range described above by adjusting the microstructure of the diene-based conjugate polymer. For example, when the diene-based conjugate polymer is a butadiene-styrene copolymer, the estimated Tg can be controlled to fall within the numerical range described above by adjusting the amount of bound styrene Xtotal (% by mass) of the diene-based conjugate polymer and the amount of vinyl linkage Ytotal (% by mol) in the bound butadiene according to expression (iii). Polymeric segment

[0050] The conjugated diene-based polymer of the present embodiment preferably has two or more polymeric segments.

[0051] The polymeric segment refers to a part of the conjugated diene-based polymer containing a di monomer unit. Petition 870250088330, dated 09 / 29 / 2025, page 21 / 139 16 / 122 conjugated ene and an aromatic vinyl monomer unit, or containing a conjugated diene monomer unit.

[0052] Furthermore, in the conjugated diene-based polymer of the present embodiment, the polymer segment preferably contains few or no blocks in which 4 or more linked aromatic vinyl monomer units are chained. When the block in which 4 or more aromatic vinyl monomer units are chained is present, the Tg range tends to be wide, which is preferable from the point of view of increasing the difference between the extrapolated initial temperature and the extrapolated final temperature, but the glass transition temperature obtained by DSC measurement tends to be easily divided into two.

[0053] The plurality of polymeric segments contained in the conjugated diene-based polymer of the present embodiment have mutually different microstructures. In the respective polymer segments, for example, the amount of the linked aromatic vinyl monomer unit and the amount of the vinyl linkage in the linked conjugated diene may be different. The respective polymeric segments can be distinguished by a method described in the examples below. First polymeric segment

[0054] The conjugated diene-based polymer of the present embodiment preferably contains a first polymeric segment that does not contain an aromatic vinyl monomer unit and a second polymeric segment that contains an aromatic vinyl monomer unit. Thus, the estimated Tg value of the first polymeric segment is less than the estimated Tg value of the conjugated diene-based polymer of the present embodiment (whole polymer value obtained by expression (1)). In this case, the estimated Tg of the first polymeric segment is calculated by assigning the respective microstructure components of the conjugated diene-based polymer. Petition 870250088330, dated 09 / 29 / 2025, page 22 / 139 17 / 122 gado to expression (1). When the conjugated diene-based polymer is a butadiene-styrene copolymer, or a butadiene homopolymer, the estimated Tg of the conjugated diene-based polymer is calculated based on the amount of styrene bonded Xtotal (% by mass) of the conjugated diene-based polymer and the amount of vinyl bonding Ytotal (% by mol) in the bonded butadiene according to expression (iii).

[0055] The first polymeric segment does not contain an aromatic vinyl monomer unit and the amount of vinyl linkage Y1 (mol %) in the conjugated diene bonded preferably satisfies the following expression (2): < Yi < 45 ... (2)

[0056] The lower bound of Yi is more preferably greater than 10, even more preferably 12 or more, and even more preferably 15 or more.

[0057] The upper bound of Yi is more preferably less than 45, even more preferably 43 or less, and even more preferably 40 or less.

[0058] When expression (2) is satisfied, the flexibility of the conjugated diene-based polymer of the present embodiment in a low temperature region is improved, and a vulcanizate thereof tends to have excellent abrasion resistance.

[0059] The amount of vinyl linkage Yi (mol%) in the conjugated diene bonded can be controlled to fall within the numerical range described above by adjusting the amount of a polar material to be added in a first polymerization step producing the first polymer segment. Second polymeric segment

[0060] The conjugated diene-based polymer of the present embodiment preferably contains the first polymeric segment that does not contain an aromatic vinyl monomer unit and the second Petition 870250088330, dated 09 / 29 / 2025, page 23 / 139 18 / 122 polymeric segment containing an aromatic vinyl monomer unit, as described above.

[0061] The second polymer segment has an estimated Tg value greater than the estimated Tg value of the conjugated diene-based polymer of the present embodiment. In this case, the estimated Tg of the second polymer segment is calculated by assigning the respective microstructure components of the second polymer segment to expression (1). When the conjugated diene-based polymer is a butadiene-styrene copolymer, or a butadiene homopolymer, the estimated Tg of the conjugated diene-based polymer is calculated based on the amount of styrene bonded Xtotal (% by mass) of the conjugated diene-based polymer and the amount of vinyl bonding Ytotal (% by mol) in the bonded butadiene according to expression (iii).

[0062] The second polymer segment has an estimated Tg of preferably more than -45°C and -5°C or less. The estimated Tg of the second polymer segment can be obtained based on the microstructure, such as the amount of bonded aromatic vinyl monomer unit Xtotal (% by mass) of the second polymer segment and the amount of vinyl linkage Ytotal (% by mol) in the bonded conjugated diene according to expression (1).

[0063] In the conjugated diene-based polymer of the present embodiment, the lower limit of the estimated Tg of the second polymer segment is preferably greater than -45°C, more preferably -44°C or more, and even more preferably -43°C or more.

[0064] The upper limit of the estimated Tg of the second polymer segment is preferably -5°C or less, more preferably -10°C or less, and even more preferably -15°C or less.

[0065] When the estimated Tg of the second polymeric segment falls within the numerical range described above, the conjugated diene-based polymer of the present embodiment has its hysteresis loss increased. Petition 870250088330, dated 09 / 29 / 2025, page 24 / 139 19 / 122 in a high-temperature region, and vulcanized from the same tends to exhibit excellent grip performance on wet surfaces.

[0066] The estimated Tg of the second polymeric segment of the conjugated diene-based polymer of the present embodiment calculated according to expression (1) can be controlled to fall within the numerical range described above by adjusting the microstructure of the second polymeric segment.

[0067] The conjugated diene-based polymer of the present embodiment may contain another polymeric segment in addition to the first polymeric segment and the second polymeric segment. For example, to increase the reactivity between the conjugated diene-based polymer and a coupling agent after the synthesis of the first and second polymeric segments, a third polymeric segment containing a conjugated diene compound may be included.

[0068] Polymer segments can be coupled together directly or can be coupled by means of a coupling agent. Ratio of polymeric segments

[0069] The ratio of polymer segments of a conjugated diene-based polymer refers to the average mass fraction of each polymer segment in the entire conjugated diene-based polymer.

[0070] The ratios of the first and second polymeric segments in the conjugated diene-based polymer of the present embodiment are defined as mass ratios, relative to the total mass of the conjugated diene-based polymer, of the polymer segments obtained in a first polymerization step (P1), which is a production step of the first polymeric segment, and a second polymerization step (P2), which is a production step of the second polymeric segment described below.

[0071] Regarding the ratio of the first polymeric segment (n) and Petition 870250088330, dated 09 / 29 / 2025, page 25 / 139 20 / 122 a ratio of the second polymeric segment (r2) in the conjugated diene-based polymer of the present embodiment, the segment ratio (n) of the first polymeric segment is preferably 20% by mass or more and 80% by mass or less, more preferably 30% by mass or more and 70% by mass or less, and even more preferably 40% by mass or more and 60% by mass or less.

[0072] When the lower limit of the ratio of the first polymer segment (1*1) falls within the range described above, the ratio of the first polymer segment in the conjugated diene-based polymer of the present embodiment falls within a preferable range, the flexibility of the conjugated diene-based polymer in a low-temperature region obtained in the form of a vulcanizate is improved, and the vulcanizate tends to have excellent abrasion resistance. When the ratio of the first polymer segment (n) satisfies the upper limit range, the ratio of the second polymer segment (r2) in the conjugated diene-based polymer falls within a preferable range, and excellent wet grip performance tends to be obtained.

[0073] The segment ratio (ιί) of the first polymeric segment in the conjugated diene-based polymer of the present embodiment can be controlled to fall within the numerical range described above by adjusting the polymerization conditions, such as the amount of a monomer to be added and a polymerization time, employed in the first polymerization step (P1).

[0074] A method for introducing a plurality of polymeric segments into a molecule of the conjugated diene-based polymer of the present embodiment is not particularly limited, and an example includes a method in which a continuous solution polymerization method using a plurality of reactors arranged in series is employed with a conjugated diene compound, an aromatic vinyl compound, a polar material and a solvent added successively. Petition 870250088330, dated 09 / 29 / 2025, page 26 / 139 21 / 122 subsequently to their respective reactors, as described below. The substances to be added successively may be the same or different between reactors. Glass transition temperature (Tg) and the difference between the extrapolated initial temperature and the extrapolated final temperature of the glass transition temperature (Tg).

[0075] The conjugated diene-based polymer of the present embodiment has only one glass transition temperature (Tg) measured by differential scanning calorimetry (DSC), and the difference between the extrapolated initial temperature and the extrapolated final temperature of the glass transition temperature (Tg) is 15°C or more and 35°C or less. Since a conjugated diene-based polymer has a glass transition caused over a wide temperature range, i.e., it has a relaxation region from an elastic to a viscous body over a wide temperature range, a vulcanizate thereof becomes easily viscous in a low-temperature region, thus achieving excellent low-temperature performance. Furthermore, the elastic region of the vulcanizate also continues into a high-temperature region, thus achieving excellent wet grip performance, and these properties can be perfectly balanced.

[0076] The conjugated diene-based polymer of the present embodiment has only one glass transition temperature (Tg) obtained by DSC measurement, as described above. It is effective, by having one glass transition temperature (Tg), that the conjugated diene-based polymer does not contain an isolated aromatic vinyl monomer unit (a segment consisting only of an aromatic vinyl monomer block or an aromatic vinyl monomer unit) and that a random conjugated diene-based polymer with a high ratio of an aromatic vinyl monomer unit is not Petition 870250088330, dated 09 / 29 / 2025, page 27 / 139 22 / 122 is present locally in an uneven way within it.

[0077] For example, when a linkage of aromatic vinyl monomer units is contained only in a portion corresponding to 30% by mass of the conjugated diene-based polymer end, and 40% by mass of the same corresponds to aromatic vinyl monomer units, the conjugated diene-based polymer has two glass transition temperatures.

[0078] The conjugated diene-based polymer that has only one glass transition temperature (Tg) means that the conjugated diene-based polymer is not separated into phases and tends to exhibit good low-temperature performance when in the form of a vulcanizate.

[0079] The glass transition temperature (Tg) of the conjugated diene-based polymer of the present embodiment indicates a point close to the midpoint between the extrapolated initial temperature and the extrapolated final temperature of differential scanning calorimetry (DSC). The measured Tg value is preferably -75°C or higher, and more preferably -70°C or higher. Furthermore, the glass transition temperature (Tg) of the conjugated diene-based polymer of the present embodiment is preferably -45°C or lower, and more preferably -50°C or lower. The glass transition temperature (Tg) may fall within a range obtained by the arbitrary combination of any of the upper and lower limits described above. The glass transition temperature (Tg) of the conjugated diene-based polymer of the present embodiment is measured in accordance with ISO 22768:2006.More specifically, a DSC curve is recorded by measuring differential scanning calorimetry (DSC) with an increasing temperature within a prescribed temperature range, and an inflection point of the DSC curve is defined as the glass transition temperature. Specifically, it can be measured by a... Petition 870250088330, dated 09 / 29 / 2025, page 28 / 139 23 / 122 method described in the examples below.

[0080] The conjugated diene-based polymer of the present embodiment may contain a plastic component, such as a resin or a process oil described below, and it is necessary to exclude such component in the DSC measurement to obtain the Tg of the conjugated diene-based polymer of the present embodiment.

[0081] The glass transition temperature (Tg) of the conjugated diene-based polymer varies depending on the amount of aromatic vinyl monomer unit attached to the conjugated diene-based polymer and the amount of vinyl linkage in the attached conjugated diene. Specifically, the glass transition temperature (Tg) is increased by increasing the amount of aromatic vinyl monomer unit attached and the amount of vinyl linkage in the attached conjugated diene, and the glass transition temperature (Tg) is decreased by decreasing the amount of aromatic vinyl monomer unit attached and the amount of vinyl linkage in the attached conjugated diene.

[0082] In the conjugated diene-based polymer of the present embodiment, the measured glass transition temperature (Tg) can be controlled to fall within a preferable range by controlling the estimated Tg described above to a more suitable numerical range by adjusting the microstructure.

[0083] The extrapolated initial temperature of the glass transition temperature (Tg) of the conjugated diene-based polymer of the present embodiment is preferably -90°C or higher and more preferably -85°C or higher. The extrapolated initial temperature is preferably -60°C or lower, and more preferably -65°C or lower. When the extrapolated initial temperature satisfies the range, a vulcanizate of the conjugated diene-based polymer of the present embodiment tends to be even more excellent in terms of tensile properties. The extrapolated final temperature of the glass transition temperature (Tg) of the Petition 870250088330, dated 09 / 29 / 2025, p. 29 / 139 24 / 122 The conjugated diene-based polymer of the present embodiment is preferably -70°C or lower and more preferably -65°C or lower. The extrapolated final temperature is preferably -40°C or lower, and more preferably -45°C or lower. When the extrapolated final temperature satisfies the range, a vulcanizate of the conjugated diene-based polymer of the present embodiment tends to be even more excellent in terms of low hysteresis loss property.

[0084] The conjugated diene-based polymer of the present embodiment has only one glass transition temperature (Tg) obtained by DSC measurement, and the difference between the extrapolated initial temperature and the extrapolated final temperature of the glass transition temperature is 15°C or more and 30°C or less. Thus, a vulcanizate obtained from it has a high hysteresis loss in a temperature region higher than the glass transition temperature and therefore tends to be excellent in terms of wet grip performance, and has a wide flexibility range at a temperature lower than the glass transition temperature and therefore tends to be excellent in terms of low-temperature performance.

[0085] From the point of view of being excellent in both wet grip performance and low temperature performance, the conjugated diene-based polymer of the present embodiment is a conjugated diene-based polymer in which the difference between the extrapolated initial temperature and the extrapolated final temperature of only one glass transition temperature is 15°C or more. The lower limit of the difference between the extrapolated initial temperature and the extrapolated final temperature is preferably 15.5°C or more, and more preferably 18°C ​​or more. The upper limit is preferably 35°C or less, and more preferably 30°C or less.

[0086] The extrapolated initial temperature varies depending on the amount of vinyl bonding Y1 in the conjugated diene bonded to the first Petition 870250088330, dated 09 / 29 / 2025, page 30 / 139 25 / 122 polymeric segment. Specifically, when the amount of vinyl linkage Yi in the linked conjugated diene is increased, the extrapolated initial temperature increases. Conversely, the extrapolated initial temperature decreases when the amount of linked aromatic vinyl monomer unit Xi, and the amount of vinyl linkage Yi in the linked conjugated diene of the first polymer segment are decreased.

[0087] For example, when Yi is 20 (mol %), the extrapolated initial temperature is -76.5°C, and when Yi is 15 (mol %), the extrapolated initial temperature is -78.0°C.

[0088] Furthermore, the extrapolated final temperature varies depending on the amount of linked aromatic vinyl monomer unit X2, and the amount of vinyl bond Y2 in the linked conjugated diene of the second polymeric segment and the ratio of the second polymeric segment r2. Specifically, the extrapolated final temperature increases when the amount of linked aromatic vinyl monomer unit X2, the amount of vinyl bond Y2 in the linked conjugated diene, and the ratio of the second polymeric segment r2 are increased. Conversely, the extrapolated final temperature decreases when the amount of linked aromatic vinyl monomer unit X2, the amount of vinyl bond Y2 in the linked conjugated diene, and the ratio of the second polymeric segment r2 are decreased.

[0089] For example, when r2 is 50 (% by mass), and a value calculated according to expression (iii) is -23, the extrapolated final temperature is -53.0°C, and when r2 is 50 (% by mass), and a value calculated according to expression (3) is -43, the extrapolated initial temperature is -58.0°C.

[0090] When a value calculated according to expression (iii) is -38, and r2 is 55, the final extrapolated temperature is -46.0°C.

[0091] Weight-average molecular weight Petition 870250088330, dated 09 / 29 / 2025, page 31 / 139 26 / 122

[0092] The weight-average molecular weight (Mw) of the conjugated diene-based polymer of the present embodiment measured by a GPC measurement method is preferably 27 x 10⁴ or more, more preferably 30 x 10⁴ or more, even more preferably 40 x 10⁴ or more, and even more preferably 45 x 10⁴ or more. When the lower limit of the weight-average molecular weight measured by the GPC measurement method satisfies the range described above, a vulcanizate thereof tends to be excellent in terms of abrasion resistance.

[0093] The weight-average molecular weight is preferably 135 x 10⁴ or less, more preferably 90 x 10⁴ or less, and even more preferably 70 x 10⁴ or less. When the upper limit of the weight-average molecular weight satisfies the range described above, the vulcanizate tends to be more excellent in terms of the ability to disperse a filler contained therein.

[0094] The weight-average molecular weight may fall within a range obtained by the arbitrary combination of any of the upper and any of the lower limits described above. The weight-average molecular weight of the conjugated diene-based polymer may be measured by a GPC measurement method and, specifically, may be measured by a method described in the examples below. number average molecular weight

[0095] The number average molecular weight of the conjugated diene-based polymer of the present embodiment, measured by a GPC measurement method, is preferably 17 x 10⁴ or more, more preferably 19 x 10⁴ or more, and even more preferably 23 x 10⁴ or more. When the lower limit of the number average molecular weight measured by the GPC measurement method satisfies the range described above, a vulcanizate thereof tends to be excellent in terms of abrasion resistance. The number average molecular weight is preferably 80 x 10⁴ or less, more preferably 50 x 10⁴ or less. Petition 870250088330, dated 09 / 29 / 2025, p. 32 / 139 27 / 122 less, and preferably 40 x 104 or less. When the upper limit of the number average molecular weight satisfies the range described above, the vulcanizate tends to be more excellent in terms of the dispersion capacity of a filler contained therein. The number average molecular weight can fall within a range obtained by the arbitrary combination of any of the upper and any of the lower limits described above. The number average molecular weight of the conjugated diene-based polymer can be measured by a GPC measurement method and, specifically, can be measured by a method described in the examples below.

[0096] The weight-average molecular weight and the number-average molecular weight of the conjugated diene-based polymer can be controlled to fall within the ranges described above by adjusting a ratio between the amount of a polymerization initiator to be used and the amount of monomer to be used, and the type and amount of a coupling agent to be used. Molecular weight distribution

[0097] A molecular weight distribution of the conjugated diene-based polymer of the present embodiment is represented by a ratio between the weight-average molecular weight (Mw) and the number-average molecular weight (Mn). The molecular weight distribution of the conjugated diene-based polymer of the present embodiment is preferably 1.7 or more and 2.5 or less. A conjugated diene-based polymer with a molecular weight distribution within this range tends to be more excellent in terms of processability in obtaining a vulcanizate from it.

[0098] The molecular weight distribution of the conjugated diene polymer of the present embodiment is more preferably 1.75 or more, and even more preferably 1.8 or more. The molecular weight distribution is more preferably 2.4 or less, and even more preferably Petition 870250088330, dated 09 / 29 / 2025, page 33 / 139 28 / 122 preferably 2.2 or less.

[0099] Mooney's viscosity

[00100] A Mooney viscosity measured at 100°C of the conjugated diene-based polymer of the present embodiment is preferably 30 or more and 150 or less, more preferably 60 or more and 130 or less, and even more preferably 60 or more and 115 or less. When the Mooney viscosity falls within the range described above, the fluidity of the conjugated diene-based copolymer of the present embodiment is reduced to obtain excellent moldability, and the fracture performance and abrasion resistance of a vulcanizate thereof tend to be even better. The Mooney viscosity of the conjugated diene-based polymer of the present embodiment can be measured by a method described in the examples below. Reason for modification

[00101] The conjugated diene-based polymer of the present embodiment preferably has a nitrogen atom and, more specifically, has a modifying group with a nitrogen atom.

[00102] Here, the term modification ratio refers to, when a mixture of a modified conjugated diene-based polymer and an unmodified conjugated diene-based polymer can be obtained by modifying a conjugated diene-based polymer with a modifier having a nitrogen atom, a content, expressed as % by mass, of a conjugated diene-based polymer component having, in a polymer molecule, a specific functional group with affinity or reactivity for binding with a filler to the total amount of the mixture of conjugated diene-based polymers. Thus, when the specific functional group has a nitrogen atom, the modification ratio indicates a mass ratio of a conjugated diene-based polymer containing a nitrogen atom to the total amount of the mixture of conjugated diene-based polymers. Petition 870250088330, dated 09 / 29 / 2025, page 34 / 139 29 / 122 conjugated diene.

[00103] For example, when a conjugated diene-based polymer containing a modified conjugated diene-based polymer is obtained by reacting a terminal end of the conjugated diene-based polymer with a nitrogen-containing modifier, a mass ratio of a conjugated diene-based polymer having a nitrogen-containing functional group derived from the nitrogen-containing modifier to the total amount of the conjugated diene-based polymer corresponds to the modification ratio.

[00104] The modification ratio can be measured by chromatography capable of separating a modified component containing a functional group and an unmodified component.

[00105] An example of a method employing chromatography includes a method in which a gel permeation chromatography column using, as packing, a polar material that adsorbs a specific functional group, such as silica, is used to perform quantitative determination using an internal standard of a non-adsorbed component for comparison.

[00106] More specifically, the modification ratio can be obtained by measuring an amount of adsorption on a silica column based on the difference between a chromatogram measured on a sample solution containing a sample and a low molecular weight internal standard polystyrene using a polystyrene-based gel column and a chromatogram measured using a silica-based column. More specifically, the modification ratio can be measured by a method described in the examples.

[00107] In the conjugated diene-based polymer of the present embodiment, the modification ratio can be controlled by adjusting the amount of modifier to be added and a reaction method.

[00108] For example, when a method in which polymerization is Petition 870250088330, dated 09 / 29 / 2025, page 35 / 139 30 / 122 performed using, as a polymerization initiator, a lithium organic compound having at least one nitrogen atom in a molecule described below, a method in which a monomer having at least one nitrogen atom in a molecule is copolymerized, and a method in which a modifier having a structural formula described below is used are combined, and the polymerization conditions are controlled, and thus, a desired modification ratio can be obtained.

[00109] In the conjugated diene-based polymer of the present embodiment, from the point of view of a low hysteresis loss property of a vulcanizate thereof, the modification ratio is preferably 60% or more, more preferably 65% ​​or more, and even more preferably 70% or more in relation to the total amount of the conjugated diene-based polymer.

[00110] Method for the production of conjugated diene-based polymer

[00111] An example of a method for producing a conjugated diene-based polymer of the present embodiment includes, for example, but is not limited to, a method that uses two or more continuous reactors, including a first polymerization step (P1) of continuous formation of a first polymeric segment of the conjugated diene-based polymer with a conjugated diene compound, a polymerization initiator and a polar material added to the continuous reactors; and a second polymerization step (P2) of formation of a second polymeric segment at one end of the first polymeric segment with an aromatic vinyl compound and a polar material added to the continuous reactors.

[00112] Continuous reactors preferably have a configuration that includes two or more reactors. Polymerization initiator Petition 870250088330, dated 09 / 29 / 2025, page 36 / 139 31 / 122

[00113] At least one monolithium organic compound can be used as a polymerization initiator.

[00114] Examples of monolithium organic compounds include, but are not limited to, monolithium organic compounds of a low molecular weight compound and a soluble oligomer.

[00115] Examples of monolithium organic compounds also include, in terms of the type of bonding between an organic group and the lithium contained therein, a compound with a carbon-lithium bond, a compound with a nitrogen-lithium bond, and a compound with a tin-lithium bond.

[00116] The amount of monolithium organic compound to be used as a polymerization initiator is preferably determined depending on the molecular weight of a conjugated diene-based polymer or modified conjugated diene-based polymer to be obtained.

[00117] The amount of a monomer, such as a conjugated diene compound, to be used relative to the amount of polymerization initiator to be used refers to a degree of polymerization. Specifically, the amount of a monomer to be used relative to the amount of polymerization initiator to be used tends to relate to the number-average molecular weight and the weight-average molecular weight.

[00118] Consequently, to increase the molecular weight, the amount of polymerization initiator to be used can be adjusted to be decreased, and to decrease the molecular weight, the amount of polymerization initiator to be used can be adjusted to be increased.

[00119] When a nitrogen atom is to be introduced into the conjugated diene-based polymer using the polymerization initiator, the monolithium organic compound is preferably one with Petition 870250088330, dated 09 / 29 / 2025, page 37 / 139 32 / 122 alkyl-lithium compound with a substituted amino group, or dialkylamino-lithium from the point of view that the compound is used in one of the methods for introducing a nitrogen atom into a conjugated diene-based polymer.

[00120] In this case, a diene-based polymer is obtained conjugated with a nitrogen atom from an amino group at the polymerization start.

[00121] A substituted amino group refers to an amino group that has no active hydrogen or that has a structure that includes protected active hydrogen.

[00122] Examples of alkyl-lithium compounds containing an amino group without an active hydrogen include, but are not limited to, 3-dimethylaminopropyl-lithium, 3-diethylaminopropyl-lithium, 4-(methylpropylamino)butyl-lithium and 4-hexamethyleneiminobutyl-lithium.

[00123] Examples of alkyl-lithium compounds containing an amino group with a structure including protected active hydrogen include, but are not limited to, 3-bistrimethylsilylaminopropyl-lithium and 4-trimethylsilylmethylaminobutyl-lithium.

[00124] Examples of dialkylaminolithium include, but are not limited to, lithium dimethylamide, lithium diethylamide, lithium dipropylamide, lithium dibutylamide, lithium di-n-hexylamide, lithium diheptylamide, lithium diisopropylamide, lithium dioctylamide, lithium-di-2-ethylhexylamide, lithium didecylamamide, lithium ethylpropylamide, lithium ethylbutylamide, lithium ethylbenzylamide, lithium methylphenethylamide, lithium hexamethyleneimide, lithium pyrrolide, lithium piperide, lithium heptamethyleneimide, lithium morpholide, 1-lithioazacyclooctane, 6-lithium-1,3,3-trimethyl-6-azabicyclo[3.2.1]octane and 1-lithium-1,2,3,6-tetrahydropyridine.

[00125] A monolithium organic compound with a substituted amino group can be reacted with a small amount of a polymerizable monomer, such as 1,3-butadiene, isoprene, or styrene, Petition 870250088330, dated 09 / 29 / 2025, p. 38 / 139 33 / 122 to be used also as a soluble oligomer monolithium organic compound.

[00126] Alternatively, the polymerization initiator may be that produced by the reaction of an aromatic vinyl compound having a substituted amino group and / or a diene compound conjugated with a monolithium organic compound, and may be that in which a functional group may be introduced at one end of a polymer chain.

[00127] The monolithium organic compound is preferably an alkyllithium compound from the point of view of industrial availability and controllability of the polymerization reaction. In this case, a diene-based polymer conjugated with an alkyl group is obtained at the early end of the polymerization.

[00128] Examples of alkyl-lithium compounds include, but are not limited to, n-butyl-lithium, sec-butyl-lithium, tert-butyl-lithium, n-hexyl-lithium, benzyllithium, phenyllithium, and stilbene-lithium.

[00129] As with the alkyl-lithium compound, from the point of view of industrial availability and the controllability of a polymerization reaction, n-butyl-lithium and sec-butyl-lithium are preferred.

[00130] One of these monolithium organic compounds may be used individually, or two or more of them may be used together. Alternatively, another organic metal compound may be used in conjunction.

[00131] Examples of other organic metallic compounds include alkaline earth metal compounds, other alkali metal compounds, and other organic metallic compounds.

[00132] Examples of alkaline earth metal compounds include, but are not limited to, organic magnesium compounds, organic calcium compounds, and organic strontium compounds. Other examples include alkoxide compounds, sulfonates, and carbonates. Petition 870250088330, dated 09 / 29 / 2025, page 39 / 139 34 / 122 and alkaline earth metal amides.

[00133] Examples of organic magnesium compounds include dibutyl magnesium and ethyl butyl magnesium. Examples of other organic metallic compounds include organic aluminum compounds.

[00134] In the present embodiment of the method for producing a conjugated diene-based polymer, a coupling step (P3) of reacting a coupling agent with the conjugated diene-based polymer can be carried out after the second polymerization step (P2).

[00135] The weight-average molecular weight of the conjugated diene-based polymer before the coupling step (P3) can be controlled by adjusting the amount of polymerization initiator to be used relative to the conjugated diene compound and the aromatic vinyl compound, and as the amount of polymerization initiator to be used decreases, the weight-average molecular weight tends to decrease. The amount of polymerization initiator to be used is preferably 0.15 mol or more and 1.5 mol or less, assuming that the total mass of the conjugated diene compound and the aromatic vinyl compound to be used is 100 kg. Polar material

[00136] In the polymerization step, a polar material can be added. The polar material can cause the aromatic vinyl compound to be randomly copolymerized with the conjugated diene compound, and the polar material tends to be usable as a vinylizing agent to control the microstructure of a conjugated diene moiety. In addition, it also tends to have an effect on accelerating the polymerization reaction or similar.

[00137] Examples of polar material include, but are not limited to, ethers such as tetrahydrofuran, diethyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, dimethyl ether of Petition 870250088330, dated 09 / 29 / 2025, page 40 / 139 35 / 122 diethylene glycol, diethylene glycol dibutyl ether, dimethoxybenzene and 2,2-bis(2-oxolanyl)propane; tertiary amine compounds such as tetramethylethylenediamine, dipiperidineethane, trimethylamine, triethylamine, pyridine and quinuclidine; alkali metal alkoxide compounds such as potassium tert-amylate, potassium tert-butylate, sodium tert-butylate and sodium amylate; and phosphine compounds such as triphenylphosphine.

[00138] One of these polar materials can be used individually, or two or more of them can be used together.

[00139] The amount of polar material to be used is not especially limited and can be selected according to the purpose or similar, and is preferably 0.01 mol or more and 100 mol or less in relation to 1 mol of the polymerization initiator.

[00140] This polar material (vinylizing agent) can be used as an adjuster for the microstructure of the conjugated diene portion of the conjugated diene-based polymer, in an appropriate amount according to a desired amount of vinyl linkage. Many polar materials exhibit an effective randomization effect in the copolymerization of a conjugated diene compound and an aromatic vinyl compound simultaneously, and tend to be able to adjust the randomness of one aromatic vinyl monomer unit and one conjugated diene monomer unit in each polymer segment.

[00141] As a method for randomizing a conjugated diene monomer unit and an aromatic vinyl monomer unit, for example, as described in Japanese Public Domain Patent No. 59-140211, a method can be employed in which a copolymerization reaction is initiated using the entire amount of styrene and a portion of 1,3-butadiene, with the remainder of the 1,3-butadiene added intermittently during the copolymerization reaction. The 1,3-butadiene added here is added to obtain a high rate. Petition 870250088330, dated 09 / 29 / 2025, page 41 / 139 36 / 122 modification ratio in the coupling step (P3) and does not always need to form a polymer segment.

[00142] A polymerization temperature employed in the polymerization step is preferably a temperature at which polymerization of the living anion occurs and, from a productivity standpoint, is preferably 0°C or higher, and more preferably 120°C or lower. When the temperature is within this range, there is a tendency for a sufficient amount of modifier to react at the active end after polymerization is complete. The temperature is even more preferably 50°C or higher and 100°C or lower. Polymerization stage of the polymer segment

[00143] In a suitable aspect of the method for producing a conjugated diene-based polymer of the present embodiment, the polymerization step is carried out in a continuous reactor system using two or more continuous reactors, and the first polymerization step (P1) to obtain a first polymeric segment, and the second polymerization step (P2) to obtain a second polymeric segment are carried out as described above.

[00144] Each of the first polymerization stage (P1) and the second polymerization stage (P2) can be carried out using one reactor or two or more connected reactors. The reactor format can be any of the tank and tubular reactors equipped with a stirrer. It is not essential to assign the first polymerization stage (P1) and the second polymerization stage (P2) to their respective reactors and, for example, the second polymerization stage (P2) can be set to start on the downstream side of a first reactor. The respective reactors may have a temperature control function.

[00145] In a continuous reactor system, one reactor or two or more connected reactors may be used. As a continuous reactor, for example, a tank or tubular reactor equipped with a Petition 870250088330, dated 09 / 29 / 2025, page 42 / 139 37 / 122 agitator. In the continuous reactor system, a monomer, an inert solvent, and a polymerization initiator are preferably fed continuously to the reactor, a polymer solution containing a conjugated diene-based polymer is obtained in the reactor, and the conjugated diene-based polymer solution is continuously discharged.

[00146] In a continuous reactor system, when a monomer, an inert solvent, and a polar material are newly added to a tube connecting the reactors when using continuous tank reactors connected in series, and to an intermediate portion of a reactor when using a tubular reactor, a polymeric segment different from that which was synthesized in the previous polymerization step can be introduced into the conjugated diene-based polymer. Furthermore, the linkage mode of a conjugated diene compound is also altered by changing the polymerization temperature employed in a reactor, and thus a different polymeric segment can be introduced into the conjugated diene-based polymer.

[00147] In the present embodiment of the method for producing a conjugated diene-based polymer, a continuous mode is preferably employed to obtain a conjugated diene-based polymer, in which a polymer is continuously discharged to be fed to a subsequent reaction in a short period of time. More preferably, a reaction system is used in which continuous tank reactors are connected in series, thus increasing the residence time distribution in the reactors and increasing the molecular weight distribution of each polymer segment. In addition, the randomization effect for the aromatic vinyl compound is increased. As a result, in a vulcanizate obtained from it, the microphase separation of the conjugated diene-based polymer is suppressed to obtain only one glass transition temperature and, simultaneously, wet grip performance and the Petition 870250088330, dated 09 / 29 / 2025, page 43 / 139 38 / 122 performance at low temperatures tends to be excellent.

[00148] In the first polymerization step (P1) for the production of a first polymer segment, a conjugated diene compound, a polymerization initiator, and a polar material are added to the reactor to continuously carry out the polymerization. A conjugated diene polymer solution resulting from the first polymerization step (P1) flows continuously out of the reactor to be fed into the next step. The destination of the feed is, for example, preferably the second polymerization step (P2) for the formation of a second polymer segment.

[00149] In the second polymerization step (P2) for a second polymer segment, one reactor or two or more connected reactors are used in the same way as in the polymerization step (P1). To a diene-based polymer conjugated from the first polymer segment obtained in the first polymerization step (P1), an aromatic vinyl compound and an additional polar material are added to continuously carry out the polymerization.

[00150] A conjugated diene polymer solution resulting from the second polymerization step (P2) flows continuously out of the reactor to be fed into the next step.

[00151] The destination of the feed is, for example, preferably the coupling stage (P3) described below.

[00152] The conjugated diene-based polymer of the present embodiment can also be produced by the following method.

[00153] To form a first polymer segment and a second polymer segment in the conjugated diene-based polymer, a continuous polymerization method using two or more reactors is employed. For example, in the first polymerization step (P1) of producing the first polymer segment, an aromatic vinyl compound, a conjugated diene compound, a polymerization initiator Petition 870250088330, dated 09 / 29 / 2025, page 44 / 139 39 / 122 A polar material and a polymerization compound are added to a first reactor to continuously perform the polymerization, and in the second polymerization step (P2) of forming the second polymer segment, without adding an additional aromatic vinyl compound to the second and subsequent reactors, the conditions for the polymerization step employed in the respective reactors are altered. In this way, the conjugated diene-based polymer of the present embodiment can also be produced.

[00154] Specifically, a polymerization reaction rate in the first reactor used in the first polymerization step (P1) is decreased as described below to cause, in the second polymerization step (P2) or later, the polymerization of the conjugated diene compound and the aromatic vinyl compound that did not react in the first polymerization step (P1). In this way, the first polymer segment and the second polymer segment can be formed in the conjugated diene polymer.

[00155] More specifically, the production method described above can be carried out more easily by setting the polymerization reaction rate in the first polymerization step (P1) to 60% or less.

[00156] When a method described in International Publication No. WO2018 / 128285 is employed, the molecular weight distribution in a conjugated diene-based polymer is reduced.

[00157] When the molecular weight distribution of a conjugated diene-based polymer is 1.7 or higher, a vulcanizate thereof tends to have excellent processability.

[00158] In the method for producing a conjugated diene-based polymer of the present embodiment, in the second polymerization step (P2) after the first polymerization step (P1), it is preferable that an aromatic vinyl compound and an additional polar material be Petition 870250088330, dated 09 / 29 / 2025, page 45 / 139 40 / 122 added to a conjugated diene-based polymer of the first polymer segment obtained in the first polymerization step (P1) to continuously perform the polymerization. In the production method described above, unlike the production method in which the second polymerization step (P2) is performed with an aromatic vinyl compound added in the first polymerization step (P1), the polymerization reaction rate in the first polymerization step can be improved. As a result, the molecular weight distribution of the conjugated diene-based polymer can be set to 1.7 or higher, and therefore, a vulcanizate thereof tends to have excellent processability.

[00159] In the method for producing a conjugated diene-based polymer of the present embodiment, the polymerization reaction rate in the first polymerization step (P1) is preferably 75% or more and 95% or less, more preferably 80% or more and 94% or less, and even more preferably 85% or more and 93% or less. When continuous polymerization is carried out using two or more continuous reactors, and the polymerization reaction rate described above is employed, there is a tendency that the molecular weight distribution of the resulting conjugated diene-based polymer can be increased, and that the processability of a vulcanizate thereof can be improved.

[00160] In the method for producing a conjugated diene-based polymer of the present embodiment, a mass ratio between the conjugated diene compound added in the first polymerization step (P1) and the total amount of conjugated diene compound and aromatic vinyl compound to be added is preferably 20% by mass or more and 80% by mass or less, more preferably 30% by mass or more and 70% by mass or less, and even more preferably 40% by mass or more and 60% by mass or less. Petition 870250088330, dated 09 / 29 / 2025, page 46 / 139 41 / 122

[00161] When the polymerization step is carried out with the ratio falling within this range, the ratio of the first polymer segment in the conjugated diene-based polymer can be defined as preferably 20% by mass or more and 80% by mass or less, more preferably 30% by mass or more and 70% by mass or less, and even more preferably 40% by mass or more and 60% by mass or less.

[00162] When the ratio of the first polymer segment satisfies the numerical range described above, the abrasion resistance obtained in the form of a vulcanizate tends to be excellent.

[00163] The polymerization reaction rate in the first polymerization step (P1) can be calculated using the following expression (7).

[00164] For example, the polymerization reaction rate in the first polymerization step (P1) can be calculated based on the solids content of a conjugated diene-based polymer obtained per time after the first polymerization step (P1) in relation to the total amount of conjugated diene compound and aromatic vinyl compound to be added per time in the first polymerization step (P1).

[00165] The solids content (m1) in the conjugated diene-based polymer solution is obtained based on the amount of a non-volatile component in the polymer solution that flows through a discharge port of the first polymerization stage (P1) in a unit of time.

[00166] Specifically, the total amount of polymer solution flowing through the discharge port of the first polymerization stage (P1) is collected for 3 minutes, and immediately after that, a polymerization terminator is added. Then, the collected solution is transferred to a heat-resistant dish or similar, and a mass M1 of a solid remaining after drying the resulting solution is obtained. Petition 870250088330, dated 09 / 29 / 2025, page 47 / 139 42 / 122 in an oven at 140°C for 30 minutes or more is measured. The solids content (m1) is obtained using the following expressions (7) and (8) in combination. Polymerization reaction rate (%) in P1 Polymerization reaction rate (%) in P1 Solids content [g / min] Conjugated diene compound added to the first reactor [g / min] + aromatic vinyl compound added to the first reactor [g / min] (7) Mass of solids Mi[g / 3min]-^3 Conjugated diene compound added to the first reactor [g / min] + aromatic vinyl compound added to the first reactor [g / min] In the second polymerization step (P2) of forming the second polymer segment, an aromatic vinyl compound is preferably added, as described above.

[00167] By controlling a mass ratio between the amount of aromatic vinyl compound to be added and the amount of conjugated diene compound to be added in the second polymerization step (P2), a ratio of one unit of aromatic vinyl monomer in the second polymer segment can be controlled and thus an elastic property of the resulting conjugated diene-based polymer in a high-temperature region tends to be retained. Specifically, the lower limit of the mass ratio is preferably 0.15 or more, more preferably 0.25 or more, and even more preferably 0.30 or more.

[00168] When the amount of aromatic vinyl compound to be added in the second polymerization step (P2) is increased, the amount of aromatic vinyl monomer unit linked to the second polymer segment in the conjugated diene-based polymer is increased, and a vulcanizate thereof tends to have excellent wet grip performance.

[00169] The upper limit of the mass ratio between the quantity of Petition 870250088330, dated 09 / 29 / 2025, page 48 / 139 43 / 122 aromatic vinyl compound to be added and the amount of conjugated diene compound to be added in the second polymerization step (P2) is preferably 0.70 or less, more preferably 0.65 or less, and even more preferably 0.60 or less.

[00170] When the amount of aromatic vinyl compound to be added in the second polymerization step (P2) is within the prescribed range, the amount of aromatic vinyl monomer unit attached to the second polymer segment in the conjugated diene-based polymer can be adjusted to a desired range, and a vulcanizate thereof tends to have excellent directional stability.

[00171] In the second polymerization stage (P2), one or two or more polar materials may be added. Thus, the amount of vinyl bond Y2 in the conjugated diene bonded to the second polymer segment is increased, and a vulcanizate thereof tends to have better wet grip performance.

[00172] The amount of polar material to be added in the second polymerization step (P2) is not especially limited and can be selected according to the purpose or similar, and the total amount thereof, together with the polar material added in the first polymerization step (P1), is preferably 0.01 mol or more and 100 mol or less per mol of polymerization initiator. Furthermore, from the point of view that a bonded aromatic vinyl compound is reacted in the second polymerization step (P2) in such a way as not to form a monomer of bonded aromatic vinyl compound in a block, the amount of polar material to be added in the second polymerization step (P2) is preferably greater than that added in the first polymerization step (P1).Although the relationship in quantity is not especially limited, for example, the previous quantity is preferably greater than 1.0 times and 25 times or less, and more preferably 1.5 times or more and 20 times or less. Petition 870250088330, dated 09 / 29 / 2025, page 49 / 139 44 / 122 nos.

[00173] The production of a conjugated diene-based polymer of the present embodiment may include prescribed steps, respectively, before and after the first polymerization step (P1) and before and after the second polymerization step (P2). For example, a polymerization step forming a polymer segment different from the first polymer segment and the second polymer segment may be included.

[00174] From the point of view of a modification ratio employed in the coupling step described below, the polymerization steps are preferably carried out in the order of the first polymerization step (P1) and the second polymerization step (P2), but the order is not limited to them. For example, when the first polymerization step (P1) is carried out at a high polymerization temperature without adding an aromatic vinyl compound after carrying out the second polymerization step (P2), a modified diene-based polymer is obtained by carrying out the coupling step after obtaining the second polymer segment and the first polymer segment.

[00175] From the point of view of reaction controllability, a conversion rate is preferably high at each polymerization step. Coupling stage (P3)

[00176] In the method for producing a conjugated diene-based polymer of the present embodiment, a coupling step can be performed at an active end of the conjugated diene-based polymer obtained through the polymerization steps described above with a coupling agent, such as a trifunctional or higher reactive compound, and / or a modification step at the active end with a modifier having a group containing atoms Petition 870250088330, dated 09 / 29 / 2025, page 50 / 139 45 / 122 of nitrogen (preferably, a coupling agent having a group containing nitrogen atoms).

[00177] The coupling implementation step and / or the modification step will be referred to as the coupling step (P3) in the following stages.

[00178] In the coupling step (P3), one end of the active end of the conjugated diene-based polymer is subjected to a modification reaction with a coupling agent or a modifier with a nitrogen atom, and thus a modified conjugated diene-based polymer is obtained. Coupling agent

[00179] In the method for producing a conjugated diene-based polymer of the present embodiment, the coupling agent used in the coupling step can have any structure, provided that it is a trifunctional or higher reactive compound, and is preferably a trifunctional or higher reactive compound having a silicon atom.

[00180] Examples of the trifunctional or higher reactive compound having a silicon atom include, but are not limited to, a halogenated silane compound, an epoxidized silane compound, a vinylized silane compound, an alkoxysilane compound, and an alkoxysilane compound containing a nitrogen-containing group, and an aminoalkoxysilane compound is preferred.

[00181] Examples of halogenated silane compounds used as coupling agents include, but are not limited to, methyltrichlorosilane, tetrachlorosilane, tris(trimethylsiloxy)chlorosilane, tris(dimethylamino)chlorosilane, hexachlorodisilane, bis(trichlorosilyl)methane, 1,2-bis(trichlorosilyl)ethane, 1,2-bis(methyldichlorosilyl)ethane, 1,4-bis(trichlorossilyl)butane and 1,4-bis(methyldichlorossilyl)butane.

[00182] Examples of epoxidized silane compounds used as coupling agents include, but are not limited to, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, Petition 870250088330, dated 09 / 29 / 2025, page 51 / 139 46 / 122 3-glycidoxypropylmethyldiethoxysilane and epoxy-modified silicone. Modifier with a group containing a nitrogen atom.

[00183] Examples of the modifier having a group containing a nitrogen atom include, but are not limited to, an isocyanate compound, an isothiocyanate compound, an isocyanuric acid derivative, a carbonyl compound containing a nitrogen atom, a vinyl compound containing a nitrogen atom, and an epoxy compound containing a nitrogen atom.

[00184] In the modifier containing a nitrogen-containing group, the nitrogen-containing group is preferably an amine compound that does not have an active hydrogen, and examples include a tertiary amine compound, a protected amine compound in which the active hydrogen is replaced by a protecting group, an imine compound represented by a general formula, -N=C, and an alkoxysilane compound attached to the nitrogen-containing group.

[00185] Examples of isocyanate compounds used as modifiers having a nitrogen-containing group include, but are not limited to, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenylmethane diisocyanate, polymeric diphenylmethane diisocyanate (C-MDI), phenyl isocyanate, isophorone diisocyanate, hexamethylene diisocyanate, butyl isocyanate, and 1,3,5-benzene triisocyanate.

[00186] Examples of isocyanuric acid derivatives used as modifiers having a nitrogen-containing group include, but are not limited to, 1,3,5-tris(3-trimethoxysilylpropyl)isocyanurate, 1,3,5-tris(3-triethoxysilylpropyl)isocyanurate, 1,3,5-tri(oxiran-2-yl)-1,3,5-triazinane-2,4,6-trione, 1,3,5-tris(isocyanatomethyl)-1,3,5-triazinane-2,4,6-trione and 1,3,5-trivinyl-1,3,5-triazinane-2,4,6-trione.

[00187] Examples of the carbonyl compound used as a modifier Petition 870250088330, dated 09 / 29 / 2025, page 52 / 139 47 / 122 with a group containing a nitrogen atom include, but are not limited to, 1,3-dimethyl-2-imidazolidinone, 1-methyl-3-ethyl-2-imidazolidinone, 1-methyl-3-(2-methoxyethyl)-2-imidazolidinone, N-methyl-2-pyrolidon, N-methyl-2-piperidone, N-methyl-2-quinolone, 4,4'-bis(diethylamino)benzophenone, 4,4'-bis(dimethylamino)benzophenone, 2-methylpyridyl ketone, 4-methylpyridyl ketone, 2-propylpyridyl ketone, 4-di-pyridyl ketone, 2-benzoylpyridine, N,N,N',N'-tetramethylurea, N,N-dimethyl-N',N'-diphenylurea, methyl N,N-diethylcarbamate, Ν,Ν-diethylacetamide, N,N-dimethyl-N',N'-dimethylaminoacetamide, Ν,Ν-dimethyl picolinic acid amide and Ν,Ν-dimethyl isonicotinic acid amide.

[00188] Examples of vinyl compounds used as modifiers having a nitrogen-containing group include, but are not limited to, N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, N-methylmaleimide, N-methylphthalimide, N,N-bistrimethylsylacrylamide, morpholinoacrylamide, 3-(2-dimethylaminoethyl)styrene, (dimethylamino)dimethyl-4-vinylphenylsilane, 4,4'-vinylidane bis(N,N-dimethylaniline), 4,4'-vinylidane bis(N,N-dimethylaniline), 1,1-bis(4-morpholinophenyl)ethylene, and 1-phenyl-1-(4-N,N-dimethylaminophenyl)ethylene.

[00189] An example of an epoxy compound used as a modifier having a group containing a nitrogen atom includes, but is not limited to, a hydrocarbon compound containing an epoxy group bonded to an amino group, which may further have an epoxy group bonded to an ether group.

[00190] An example of such an epoxy compound includes, but is not limited to, an epoxy compound represented by the following general formula (a): (R2-CH-CH-R1-N )n—R— (O—R4—CH—CH—Re)m OR3O(a) Petition 870250088330, dated 09 / 29 / 2025, page 53 / 139 48 / 122

[00191] In formula (a), R represents a divalent or higher hydrocarbon group, or a divalent or higher organic group having at least one polar group selected from a polar group having oxygen, such as ether, epoxy or ketone, a polar group having sulfur, such as thioether or thioketone, and a polar group having nitrogen, such as a tertiary amino group or an imino group.

[00192] A divalent or higher hydrocarbon group is a linear, branched, or cyclic hydrocarbon group that is optionally saturated or unsaturated and includes an alkylene group, an alkenylene group, a phenylene group, and the like. A hydrocarbon group with 1 to 20 carbon atoms is preferred. Examples include groups such as methylene, ethylene, butylene, cyclohexylene, 1,3-bis(methylene)-cyclohexane, 1,3-bis(ethylene)-cyclohexane, o-, m- or p-phenylene, m- or p-xylene and bis(phenylene)-methane.

[00193] In formula (a), R1 and R4 are a hydrocarbon group with 1 to 10 carbon atoms and R1 and R4 are optionally the same or different.

[00194] In formula (a), R2 and R5 are hydrogen, or a hydrocarbon group with 1 to 10 carbon atoms, and R2 and R5 are optionally the same or different.

[00195] In formula (a), R3 is a hydrocarbon group with 1 to 10 carbon atoms, or a structure represented by the following formula (a1).

[00196] R1, R2, and R3 may be a mutually linked cyclic structure.

[00197] When R3 is a hydrocarbon group, R3 can be a cyclic structure mutually bonded to R. In the cyclic structure, N bonded to R3 can be directly bonded to R.

[00198] In formula (a), n is an integer of 1 or more, in is 0, or an integer of 1 or more. Petition 870250088330, dated 09 / 29 / 2025, page 54 / 139 49 / 122 r2—ch—ch—r1— (a1)

[00199] In formula (a1), R1 and R2 are defined in the same way as R1 and R2 in formula (a), and R1 and R2 are optionally equal or different.

[00200] The epoxy compound used as a modifier having a group containing a nitrogen atom preferably has a hydrocarbon group containing an epoxy group and, more preferably, has a hydrocarbon group containing a glycidyl group.

[00201] A hydrocarbon group containing an epoxy group linked to an amino group or an ether group is not particularly limited, and examples thereof include a glycidylamino group, a diglycidylamino group, and a glycidoxy group. The epoxy compound preferably used as a modifier is any of the compounds containing epoxy groups containing respectively a glycidylamino group or a diglycidylamino group and a glycidoxy group, and an example thereof includes a compound represented by the following general formula (a2): CCHz-CH—CH2-N )n— R — (O-CH2-CH-CHz)m OR' (a2)

[00202] In formula (a2), R is defined in the same way as R in formula (a), and R6 is a hydrocarbon group with 1 to 10 carbon atoms, or a structure represented by the following formula (a3).

[00203] When R6 is a hydrocarbon group, R6 can be a cyclic structure mutually bonded to R and, in this case, N bonded to R6 can be directly bonded to R.

[00204] In formula (a2), n is an integer of 1 or more, in is 0, Petition 870250088330, dated 09 / 29 / 2025, page 55 / 139 50 / 122 or a whole number of 1 or more. CHa—CH—CHa— O (a3)

[00205] The epoxy compound used as a modifier having a group containing nitrogen atoms is, particularly preferably, a compound having one or more diglycidylamino groups and one or more glycidoxy groups in a molecule.

[00206] Examples of epoxy compounds used as modifiers having a nitrogen-containing group include, but are not limited to, N,N-diglycidyl-4-glycidoxyaniline, 1-N,N-diglycidylaminomethyl-4-glycidoxy-cyclohexane, 4-(4-glycidoxyphenyl)-(N,N-diglycidyl)aniline, 4-(4-glycidoxyphenoxy)-(N,N-diglycidyl)aniline, 4-(4-glycidoxybenzyl)-(N,N-diglycidyl)aniline, 4-(N,N'-diglycidyl-2-piperazinyl)-glycidoxybenzene, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-m-xylenediamine, 4,4-methylene-bis(N,N-diglycidylaniline), 1,4-bis(N,N-diglycidylamino)cyclohexane, N,N,N',N'-tetraglycidyl-p-phenylenediamine, 4,4'-bis(diglycidylamino)benzophenone, 4-(4-glycidylpiperazinyl)-(N,N-diglycidyl)aniline, 2-[2-(N,N-diglycidylamino)ethyl]-1-glycidylpyrrolidine, N,N-diglycidylaniline, 4,4'-diglycidyl-dibenzylmethylamine, N,N-diglycidylaniline, Ν,Ν-diglycidyl ortho-toluidine, and Ν,Ν-diglycidylaminomethylcyclohexane. Among these, N,N-diglycidyl-4-glycidoxyaniline, and 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane are particularly pre Petition 870250088330, dated 09 / 29 / 2025, page 56 / 139 51 / 122 injured.

[00207] From the point of view that the effects of the present embodiment are presented in an effective and definitive manner, the modifier is preferably an alkoxysilane compound with a group containing nitrogen atoms. Examples of such a modifier include, but are not limited to, 3-dimethylaminopropyltrimethoxysilane, 3-dimethylaminopropylmethyldimethoxysilane, 3-diethylaminopropyltriethoxysilane, 3-morpholinopropyltrimethoxysilane, 3-piperidinopropyltriethoxysilane, 3-hexamethyleneiminopropylmethyldiethoxysilane, 3-(4-methyl-1-piperazino)propyltriethoxysilane, 1-[3-(triethoxysilyl)-propyl]-3-methylhexahydropyrimidine, 3-(4-trimethylsilyl-1-piperazino)propyltriethoxysilane, 3-(3-triethylsilyl-1-imidazolidinyl)propylmethyldiethoxysilane, 3-(3-trimethylsilyl-1-hexahydropyrimidinyl)propyltrimethoxysilane, 3-dimethylamino-2-(dimethylaminomethyl)propyltrimethoxysilane, bis(3-dimethoxymethylsilylpropyl)-N-methylamine, bis(3-trimethoxysilylpropyl)-N-methylamine, bis(3-triethoxysilylpropyl)methylamine, tris(trimethoxysilyl)amine, tris(3-trimethoxysilylpropyl)amine, N,N,N',N-tetra(3-trimethoxysilylpropyl)ethylenediamine, 3-isocyanatopropyltrimethoxysilano, 3-cyanopropyltrimethoxysilano, 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane, 2,2-diethoxy-1-(3-triethoxysilylpropyl)-1-aza-2-silacyclopentane, 2-2-dimethoxy-1-(4-triemthoxysilylbutyl)-1-aza-2-silacylcohexane, 2,2-dimethoxy-1-(3-dimethoxymethylsilylpropyl)-1-aza-2-silacyclopentane, 2,2-dimethoxy-1-phenyl-1-aza-2-silacyclopentane, 2,2-diethoxy-1-butyl-1-aza-2-silacyclopentane, 2,2-dimethoxy-1-methyl-1-aza-2-silacyclopentane, 2,2-dimethoxy-8-(4-methylpiperazinyl)methyl-1,6-dioxa-2-sylacyclooctane, and Petition 870250088330, dated 09 / 29 / 2025, page 57 / 139 52 / 122 2,2-dimethoxy-8-(N,N-diethylamino)methyl-1,6-dioxa-2-sylacyclooctane.

[00208] Particularly preferred examples of the alkoxysilane compound having a nitrogen-containing group include the following:

[00209] Specific examples include tris(3-trimethoxysilylpropyl)amine, tris(3-triethoxysilylpropyl)amine, tris(3-tripropoxysilylpropyl)amine, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]amine, tetracis(3-trimethoxysilylpropyl)-1,3-propanediamine (also designated as N,N,N',N'-tetracis(3-trimethoxysilylpropyl)-1,3-propanediamine), tris(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]amine o)propyl]-1,3-propanediamine, tris(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-methyl-1-syl-2-azacyclopentane)pr opyl]-1,3-propanediamine, bis(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-[3-( 1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, tetracys(3-trimethoxysilylpropyl)-1,3-bisaminomethylcyclohexane, tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]1,3-bisaminomethylcyclohexane, tetracis(3-trimethoxysilylpropyl)-1,6-hexamethylenediamine, pentacis(3-trimethoxysilylpropyl)-diethylenetriamine, tris(3-trimethoxysilylpropyl)-methyl-1,3-propanediamine, tetracis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane, bis(3-trimethoxysilylpropyl)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl) silane, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-methoxy-1-trimethylsilyl-1-sila-2-azacyclopentane)propyl]silane, 3-tris[2-(2,2-dimethoxy-1-aza-2-silacyclopentane)ethoxy]silyl-1-trimethoxysilylpropano, Petition 870250088330, dated 09 / 29 / 2025, page 58 / 139 53 / 122 1-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-3,4,5-tris(3-trimethoxysilylpropyl)-cyclohexane, 1-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-3,4,5-tris(3-trimethoxysil ylpropyl)-cyclohexane, ether 3,4,5-tris(3-trimethoxysilylpropyl)-cyclohexyl-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl] phosphate, (3-trimethoxysilylpropyl) phosphate, and bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]phosphate.

[00210] Other examples include bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)phosphate, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]phosphate, N-(1,3-dimethylbutylidene)-3-(triethoxysilyl)-1 -propanamina, N-(1,3-dimethylbutylidene)-3-(trimethoxysilyl)-1-propanamina, N-benzylidene-3-(triethoxysilyl)propan-1-amina, N-benzylidene-3-(trimethoxysilyl)propan-1-amina, 1,1-(1,4-phenylene)bis(N-(3-(triethoxysilyl)propyl)methanamina), 1,1-(1,4-phenylene)bis(N-(3(trimethoxysilyl)propyl)methanamina), 2-methoxy-2-methyl-1-(benzylideneaminoethyl)-1-aza-2-silacyclopentane, and 2-methoxy-2-methyl-1-(4-methoxybenzylideneaminoethyl)-1-aza-2-silacyclopentane.

[00211] Other examples still include 1-methyl-4-[3-(trimethoxyxylyl)propyl]piperazine, 1-methyl-4-[3-(triethoxyxylyl)propyl]piperazine, 1-methyl-4-[3-(methyldimethoxyxylyl)propyl]piperazine, 3,3'-(1,1,3,3-tetramethoxydysiloxane-1,3-di-yl) bis(N,N-dimethylpropan-1-amine), 3,3'-(1,1,3,3-tetraethoxydysiloxane-1,3-di-yl) bis(N,N-dimethylpropan-1-amine 3,3'-(1,1,3,3-tetrapropoxydisiloxano-1,3-di-yl) bis(N,N-dimethylpropan-1-amine), 3,3'-(1,1,3,3-tetramethoxydisiloxane-1,3-di-yl) bis(N,N-diethylpropane-1-amine Petition 870250088330, dated 09 / 29 / 2025, p. 59 / 139 54 / 122 3,3'-(1,1,3,3-tetramethoxydysiloxane-1,3-di-yl) bis(N,N-dipropylpropane-1-amine), and 3,3'-(1,1,3,3-tetraethoxydysiloxane-1,3-di-yl) bis(N,N-diethylpropane-1-amine).

[00212] Further examples include 3,3'-(1,1,3,3-tetraethoxidisiloxane-1,3-di-yl) bis(N,N-diethylpropan-1 -amine), 3,3'-(1,1,3,3-tetraethoxidisiloxane-1,3-di-yl) bis(N,N-dipropylpropan-1-amine), 3,3'-(1,1,3,3-tetrapropoxidisiloxane-1,3-di-yl) bis(N,N-dipropylpropan-1-amine), 3,3'-(1,1,3,3-tetramethoxidisiloxane-1,3-di-yl) bis(N,N-diethylmethane-1-amine), 3,3'-(1,1,3,3-tetraethoxidisiloxane-1,3-di-yl) bis(N,N-diethylmethane-1 -amine), 3,3'-(1,1,3,3-tetrapropoxidisiloxane-1,3-di-yl) bis(N,N-diethylmethane-1 -amine), 3,3'-(1,1,3,3-tetramethoxidisiloxane-1,3-di-yl) bis(N,N-dimethylmethane-1 -amine), 3,3'-(1,1,3,3-tetramethoxidisiloxane-1,3-di-yl) bis(N,N-dipropylmethane-1 -amine), 3,3'-(1,1,3,3-tetrapropoxidisiloxane-1,3-di-yl) bis(N,N-dimethylmethane-1 -amine), 3,3'-(1,1,3,3-tetrapropoxydisiloxane-1,3-di-yl) bis(N,N-dipropylmethan-1-amine), 3,3'-(1,1,3,3-tetraethoxydisiloxane-1,3-di-yl) bis(N,N-dimethylmethan-1-amine), 3,3'-(1,1,3,3-tetraethoxydisiloxane-1,3-di-yl) bis(N,N-dipropylmethan-1-amine), 1,3-bis(3-(1H-imidazol-1-yl)propyl) 1,1,3,3-tetramethoxydisiloxane, 1,3-bis(3-(1H-imidazol-1-yl)propyl) 1,1,3,3-tetraethoxydisiloxane, and 1,3-bis(3-(1H-imidazol-1-yl)propyl) 1,1,3,3-tetrapropoxydisiloxane. Petition 870250088330, dated 09 / 29 / 2025, p. 60 / 139 55 / 122

[00213] In coupling modifiers that have a group containing nitrogen atoms, an example of a protected amine compound in which the active hydrogen is replaced by a protecting group includes a compound that has alkoxysilane and a protected amine in one molecule.

[00214] Examples of such compounds include, but are not limited to, N,N-bis(trimethylsilyl)aminopropyltrimethoxysilane, N,N-bis(trimethylsilyl)aminopropylmethyldimethoxysilane, N,N-bis(trimethylsilyl)aminopropyltriethoxysilane, N,N-bis(trimethylsilyl)aminopropylmethyldiethoxysilane, N,N-bis(trimethylsilyl)aminoethyltrimethoxysilane, N,N-bis(trimethylsilyl)aminoethylmethyldiethoxysilane, N,N-bis(triethylsilyl)aminopropylmethyldiethoxysilane, 3-(4-trimethylsilyl-1-piperazino)propyltriethoxysilane, 3-(3-triethylsilyl-1-imidazolidinyl)propylmethyldiethoxysilane, 3-(3-trimethylsilyl-1-hexa-hydropyrimidinyl)propyltrimethoxysilane, 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane, 2,2-diethoxy-1-(3-triethoxysilylpropyl)-1-aza-2-silacyclopentane, 2,2-dimethoxy-1-(4-trimethoxysilylbutyl)-1-aza-2-silacyclo-hexane, 2,2-dimethoxy-1-(3-dimethoxymethylsilylpropyl)-1-aza-2-silacyclopentane, 2,2-dimethoxy-1-phenyl-1 -aza-2-silacyclopentane, 2,2-diethoxy-1-butyl-1-aza-2-silacyclopentane, and 2,2-dimetoxy-1-metil-1-aza-2-silacyclopentano.

[00215] Other examples include N-(1,3-dimethylbutylidene)-3-methyl(dimethoxysilyl)-1-propanamine, N-(1,3-dimethylbutylidene)-3-methyl(diethoxysilyl)-1-propanamine, N-(1-methylethylidene)-3-(triethoxysilyl)-1-propanamine, N-(1-methylethylidene)-3-(trimethoxysilyl)-1-propanamine, N-(1-methylethylidene)-3-methyl(dimethoxysilyl)-1-propanamine, N-(1-methylethylidene)-3-methyl(diethoxysilyl)-1-propanamine, Petition 870250088330, dated 29 / 09 / 2025, p. 61 / 139 56 / 122 N-ethylidene-3-(triethoxysilyl)-1-propanamina, N-ethylidene-3-(trimethoxysilyl)-1-propanamina, N-ethylidene-3-methyl(dimethoxysilyl)-1-propanamina, N-ethylidene-3-methyl(diethoxysilyl)-1-propanamina, N-(1-methylpropylidene)-3-(triethoxysilyl)-1 -propanamina, N-(1-methylpropylidene)-3-(trimethoxysilyl)-1 -propanamina, N-(1-methylpropylidene)-3-methyl(dimethoxysilyl)-1-propanamina, N-(1-methylpropylidene)-3-methyl(diethoxysilyl)-1-propanamina, N-benzylidene-3-methyl(dimethoxysilyl)propan-1-amina, N-benzylidene-3-methyl(dimethoxysilyl)propan-1-amina, N-4-methylbenzylidene-3-(triethoxysilyl)propan-1-amina, N-4-methylbenzylidene-3-(trimethoxysilyl)propan-1-amina, N-4-methylbenzylidene-3-methyl(dimethoxysilyl)propan-1-amina, N-4-methylbenzylidene-3-methyl(diethoxysilyl)propan-1-amina, N-naphthylidene-3-(triethoxysilyl)propan-1-amina, N-naphthylidene-3-(triethoxysilyl)propan-1-amina, N-naphthylidene-3-methyl(dimethoxysilyl)propan-1-amina, 1,1-(1,4-phenylene)bis(N-(3methyl(dimethoxysilyl)propyl)methanamina), 1,1-(1,4-phenylene)bis(N-(3methyl(diethoxysilyl)propyl)methanamine), 2-ethoxy-2-methyl-1-(benzylideneaminoethyl)-1-aza-2-silacyclopentane, 2-methoxy-2-methyl-1-(methylisobutylideneaminoethyl)-1-aza-2-silacyclopentane, 1-trimethylsilyl-4-[3-(trimethoxysilyl)propyl]piperazine, and, 1-trimethylsilyl-4-[3-(triethoxysilyl)propyl]piperazine.

[00216] In the method for producing a conjugated diene-based polymer of the present embodiment, when the coupling step is carried out, it is further preferred that a modifier having a group containing nitrogen atoms represented by any of the following formulas (A) to (D) be used in the coupling step.

[00217] One of them may be used individually, or two or more of them may be used in combination. Petition 870250088330, dated 09 / 29 / 2025, page 62 / 139 57 / 122zR8 R7—NZN—R10—Si—(0Rn)a\ R9zZ(A)

[00218] Here, R10 and R11 are a hydrocarbon group with 1 to 12 carbon atoms, optionally possessing an unsaturated bond and optionally being the same or different, and R12 is a hydrocarbon group with 1 to 20 carbon atoms.

[00219] R8 and R9 are an aliphatic hydrocarbon group with 1 to 6 carbon atoms, optionally possessing an unsaturated bond and optionally being the same or different.

[00220] R7 is a hydrocarbon group with 1 to 20 carbon atoms optionally substituted by an organic group containing Si, O or N, and without active hydrogen, and optionally with an unsaturated bond.

[00221] a is an integer from 1 to 3.

[00222] In formula (B), A represents a hydrocarbon group with 1 to 20 carbon atoms, or an organic group that has at least one atom selected from the group consisting of an oxygen atom. Petition 870250088330, dated 09 / 29 / 2025, page 63 / 139 58 / 122 nio, one nitrogen atom, one silicon atom, one sulfur atom, and one phosphorus atom, and has no active hydrogen.

[00223] Each R13, R14, and R15 independently represents a single bond, or an alkylene group with 1 to 20 carbon atoms.

[00224] Each R16, R17, R18, R19, and R21 independently represents an alkyl group with 1 to 20 carbon atoms.

[00225] Each R20 and R22 independently represents an alkylene group with 1 to 20 carbon atoms.

[00226] Each R23 independently represents an alkyl group with 1 to 20 carbon atoms, or a trialkylsyl group.

[00227] Each b independently represents an integer from 1 to 3, each c independently represents 1 or 2, i represents an integer from 0 to 6, j represents an integer from 0 to 6, k represents an integer from 0 to 6 and a sum of i, jek is an integer from 4 to 10. (R24O)S— Si— R3Q— N— R31— Si— (OR25), I (C) R32 Si — R^Su) (R26O)U

[00228] In formula (C), each R24, R25, R26, R27, R28, and R29 independently represents an alkyl group with 1 to 20 carbon atoms, or an aryl group with 6 to 20 carbon atoms.

[00229] each R30, R31, and R32 independently represents an alkylene group with 1 to 20 carbon atoms.

[00230] each s, teu independently represents an integer from 1 to 3, and a sum of s, teu is an integer from 4 or Petition 870250088330, dated 09 / 29 / 2025, p. 64 / 139 59 / 122 more. . ! OR33OR35 II / NB i S i---0---S i---B3N L2I I\ I : OR34OR36(D)

[00231] In formula (D), each B1 and B2 independently represents a divalent hydrocarbon group having from 1 to 20 carbon atoms containing or not containing an oxygen atom.

[00232] R33a R36 each independently represent a monovalent hydrocarbon group with 1 to 20 carbon atoms.

[00233] L1a L4 each independently represent a divalent, trivalent or tetravalent alkylsilyl group substituted by an alkyl group with 1 to 10 carbon atoms, or a monovalent hydrocarbon group with 1 to 20 carbon atoms, or L1 and L2, and L3 and L4 are optionally linked together to form a ring with 1 to 5 carbon atoms, and when L1 and L2, and L3 and L4 are linked together to form a ring, the ring thus formed optionally contains 1 to 3 heteroatoms of one or more selected from the group consisting of N, O and S.

[00234] Specifically, in formula (D), B1 and B2 are each independently an alkylene group with 1 to 10 carbon atoms, R33 and R36 are each independently an alkyl group with 1 to 10 carbon atoms, L1 and L4 are each independently a tetravalent alkylsilyl group substituted by an alkyl group having 1 to 5 carbon atoms, or an alkyl group having 1 to 10 carbon atoms, or L1 and L2, and L3 and L4 are optionally linked together to form a ring with 1 to 3 carbon atoms, and when L1 and L2, and L3 and L4 are linked together to form a ring, the ring Petition 870250088330, dated 09 / 29 / 2025, p. 65 / 139 The 60 / 122 structure thus formed optionally contains 1 to 3 heteroatoms from one or more selected from the group consisting of N, O, and S.

[00235] Examples of the coupling modifier represented by formula (A) include, but are not limited to, 1-methyl-4-[3-(trimethoxysilyl)propyl]piperazine, 1-methyl-4-[3-(triethoxysilyl)propyl]piperazine, 1-propyl-4-[3-(trimethoxysilyl)propyl]piperazine, 1-propyl-4-[3-(triethoxysilyl)propyl]piperazine, -trimethylsilyl-4-[3-(trimethoxysilyl)propyl]piperazine and 1-trimethylsilyl-4-[3-(triethoxysilyl)propyl]piperazine.

[00236] Among these, one represented by formula (A), where a is 3, is preferred from the point of view of increasing the reactivity and interaction between the conjugated diene-based polymer of the present embodiment and an inorganic filler, such as silica, and from the point of view of increasing processability.

[00237] A reaction temperature and reaction time in the coupling step using the coupling modifier represented by formula (A) are not particularly limited, and the reaction is preferably carried out at 0°C or more and 120°C or less, and preferably for 30 seconds or more.

[00238] The amount of coupling modifier represented by formula (A) to be added corresponds to a total number of moles of an alkoxy group linked to a silyl group of the compound represented by formula (A) of preferably 0.2 or more times and 2.0 or less times, more preferably 0.3 or more times and 1.5 or less times, and even more preferably 0.4 or more times and 1.0 or less times of a number of moles of polymerization initiator to be added. From the point of view that the modified diene-based polymer thus obtained has a molecular weight that falls within a more preferable range, the amount is preferable Petition 870250088330, dated 09 / 29 / 2025, page 66 / 139 61 / 122 is preferably 0.2 or more times, and from the point of view of long-term storage stability, the quantity is preferably 2.0 or less times.

[00239] More specifically, the amounts of polymerization initiator and coupling modifier represented by formula (A) to be added can be adjusted so that the number of rnols of coupling modifier represented by formula (A) can preferably be 0.1 or more times and 1.0 or less times the number of rnols of polymerization initiator.

[00240] In formula (B), A is preferably represented by any of the following formulas (I) to (IV). —IN— D1^h( I )

[00241] In formula (I), D1 represents a single bond, or a divalent hydrocarbon group with 1 to 20 carbon atoms, eh represents an integer from 1 to 10. D1, if present in more than one, is respectively independent. D3 -4 N--D2--N-)—hdl)

[00242] In formula (II), D2 represents a single bond, or a divalent hydrocarbon group with 1 to 20 carbon atoms. D3 represents an alkyl group with 1 to 20 carbon atoms, h represents an integer from 1 to 10. Each of D2 and D3, if present in more than one, is respectively independent. Petition 870250088330, dated 09 / 29 / 2025, p. 67 / 139 62 / 122 -4- Si— D4-)—h(III)

[00243] In formula (III), D4 represents a single bond, or a divalent hydrocarbon group with 1 to 20 carbon atoms, h represents an integer from 1 to 10. D4, if present in more than one, is respectively independent. -^0—Si— D54I ho (iv)

[00244] In formula (IV), D5 represents a single bond, or a divalent hydrocarbon group with 1 to 20 carbon atoms, h represents an integer from 1 to 10. D5, if present in more than one, is respectively independent.

[00245] In formula (B), examples of the coupling modifier where A is represented by formula (I) include, but are not limited to, tris(3-trimethoxysilylpropyl)amine, bis(3-trimethoxysilylpropyl)-[3(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]amine, bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)amine, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]amine, tris(3-ethoxysilylpropyl)amine, bis(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]amine, bis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)a Petition 870250088330, dated 09 / 29 / 2025, p. 68 / 139 63 / 122 mina, tris[3-(2,2-dietóxi-1 -aza-2-silaciclopentano)propil]amina, tetracis(3-trimetoxissililpropil)-1,3-propanodiamina, tris(3-trimetoxissililpropil)-[3-(2,2-dimetóxi-1-aza-2-silaciclopentano)pro pil]-1,3-propanodiamina, bis(3-trimetoxissililpropil)-bis[3-(2,2-dimetóxi-1-aza-2-silaciclopentano)p ropil]-1,3-propanodimano, e tris[3-(2,2-dimetóxi-1-aza-2-silaciclopentano)propil]-(3-trimetoxissililpro pil)1,3-propanodiamina.

[00246] Outros exemplos include tetracis[3-(2,2-dimetóxi1 -aza-2-silaciclopentano)propil]-1,3-propanodiamina, tris(3-trimethoxysilylpropil)-[3-(1-metóxi-2-trimetilsilil-1-sila-azaciclopentano)propil]-1,3-propanodiamina, bis(3-trimethoxysilylpropil)-[3-(2,2-dimetóxi-1-aza-2-silaciclopentano)prop pil]-[3-(1-metóxi-2-trimetilsilil-1-sila-2-azaciclopentano)propil]-1,3-propa nodiamina, bis[3-(2,2-dimetóxi-1-aza-2-silaciclopentano)propil] pil)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentano)propyl]-1,3-propane diamine, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentano)propyl]-[3-(1-methoxy-2-trim ethylsilyl-1-sila-2-azacyclopentano)propyl]-1,3-propanediamine, tetracis(3-triethoxysilylpropyl)-1,3-propanediamine, and tris(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentano)propyl]1,3-propanediamine.

[00247] Other examples also include bis(3-triethoxysilylpropyl)-bis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tris[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)1,3-propanediamine, tetracis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tris(3-triethoxysilylpropyl)-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentan. Petition 870250088330, dated 09 / 29 / 2025, page 69 / 139 64 / 122 o)propil]-1,3-propanodiamina, bis(3-trietoxysililpropil)-[3-(2,2-dietóxi-1-aza-2-silacyclopentano)propil]-[ 3-(1-etóxi-2-trimetilsilil-1 -sila-2-azaciclopentano)propil]-1,3-propanodia mina, bis[3-(2,2-dietóxi-1-aza-2-silacyclopentano)propil]-(3-trietoxissililpropil)-[ 3-(1-etóxi-2-trimetilsilil-1 -sila-2-azaciclopentano)propil]-1,3-propanodia mina, tris[3-(2,2-dietoxi-1-aza-2-silaciclopentano)propyl]-[3-(1-etoxi-2-trimetilsi lil-1-sila-2-azacyclopentano)propyl]-1,3-propanodiamina, e tetracis(3-trimetoxysilylpropyl)-1,3-bisaminomethylciclo-hexano.

[00248] Other examples also include tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, bis(3-trimethoxysilylpropyl)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-1,3-bisaminomethylcyclohexane, tetracis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tris(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)pro pil]-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, and bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpro pil)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisam inomethylcyclohexane.

[00249] Other examples also include tris[3-(2,2-dimethoxy-1-aza-2-cyclopentane)propyl]-[3-(1-methoxy-2-trimethylsilyl-1-silyl-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, te Petition 870250088330, dated 09 / 29 / 2025, page 70 / 139 65 / 122 tricis(3-triethoxysilylpropyl)-1,3-propanediamina, tris(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentano)propyl]1,3-bisaminomethylcyclo-hexane, bis(3-trimethoxysilylpropyl)-bis[3-(2,2-diethoxy-1-aza-2-silacyclopentano)propyl]-1,3-bisaminomethylcyclo-hexane, tris[3-(2,2-diethoxy-1-aza-2-silacyclopentano)propyl]-(3-triethoxysilylpropyl)1,3-propanediamina, tetracis[3-(2,2-diethoxy-1-aza-2-silacyclopentano)propyl]-1,3-propanediamina, tris(3-triethoxysilylpropyl)-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentano)propyl]-1,3-bisaminomethylcyclo-hexane, bis(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentano)propyl]-[3-(1-ethoxy-2-trimethylsilyl-1 -sila-2-azacyclopentano)propyl]-1,3-bisaminomethylcyclo-hexane, bis[3-(2,2-diethoxy-1-aza-2-silacyclopentano)propyl]-(3-triethoxysilylpropyl)-[3-(1-ethoxy-2-trimethylsilyl-1 -sila-2-azacyclopentano)propyl]-1,3-bisaminomethylcyclo-hexane, tris[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-ethoxy-2-trimethylsilyl-1-syl-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, tetracys(3-trimethoxysilylpropyl)-1,6-hexamethylenediamine, and pentacis(3-trimethoxysilylpropyl)-diethylenetriamine.

[00250] In formula (B), examples of a coupling modifier wherein A is represented by formula (II) include, but are not limited to, tris(3-trimethoxysilylpropyl)-methyl-1,3-propanediamine, bis(2-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-methyl-1,3-propanediamine, bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-methyl-1,3-propanediamine, tris(3-triethoxysilylpropyl)-methyl-1,3-propanediamine, bis(2-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]methyl-1,3-propanediamine, Petition 870250088330, dated 09 / 29 / 2025, page 71 / 139 66 / 122 bis[3-(2,2-diethoxy-1-aza-2-silacyclopentano)propyl]-(3-triethoxysilylpropyl)methyl-1,3-propanediamina, N1,N1'-(propano-1,3-di-yl)bis(N1-methyl-N3,N3-bis(3-(trimethoxysilyl)propyl )-1,3-propanediamina), and N1 -(3-(bis(3-(trimethoxysilyl)propyl)amino)propyl)-N1-methyl-N3-(3-(methyl(3-(trimethoxysilyl)propyl)amino)propyl)-N3-(3-(trimethoxysilyl)propyl)amino)propyl)-1,3-propanediamina.

[00251] In formula (B), examples of a coupling modifier wherein A is represented by formula (III) include, but are not limited to, tetracis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)silane, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]silane, bis(3-trimethoxysilylpropyl)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane, (3-trimethoxysilyl)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane, [...] bis(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-syl-2-azacyclopentane)propyl]-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]silane, bis[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-bis(3-trimethoxysilylpropyl)silane, and bis(3-trimethoxysilylpropyl)-bis[3-(1-methoxy-2-methyl-1-sila-2-azacyclopentane)propyl]silane.

[00252] In formula (B), examples of the coupling modifier in which A is represented by formula (IV) include, but are not, Petition 870250088330, dated 09 / 29 / 2025, page 72 / 139 67 / 122 limited to, 3-tris[2-(2,2-dimethoxy-1-aza-2-silacyclopentane)ethoxy]silyl-1 (2,2-dimethoxy-1-aza-2-silacyclopentane)propane, and 3-tris[2-(2,2-dimethoxy-1-aza-2-silacyclopentane)ethoxy]silyl-1-trimethoxysilyl propane.

[00253] The amount of modifier represented by formula (B) to be added is preferably determined based on a ratio between a number of moles of polymerization initiator to be added and a number of moles of modifier represented by formula (B) to be added. Thus, the diene-based conjugated polymer and the modifier can be adjusted to react with each other in a desired stoichiometric ratio.

[00254] More specifically, the amounts of the polymerization initiator and the coupling modifier represented by formula (B) to be added can be adjusted so that the number of moles of the coupling modifier represented by formula (B) can preferably be 0.012 or more times and 1.0 or less times, and more preferably 0.02 or more times and 0.5 or less times the number of moles of the polymerization initiator. In this case, the number of functional groups of the modifier in formula (B) (for example, when iej are 2 or more, each of wex is present in more than one, and the plural fs and gs are respectively equal, fxi + (g + 1) xj + k) is preferably an integer from 5 to 10, and more preferably an integer from 6 to 10. From the point of view of defining the molecular weight of a modified diene-based polymer to be obtained in a preferred range, the number of moles of the modifier is preferably 0.012 or more times.Furthermore, from the point of view of long-term storage stability, the number of moles is preferably 0.2 or less.

[00255] Among these, from the point of view of increased reactivity and Petition 870250088330, dated 09 / 29 / 2025, page 73 / 139 68 / 122 interaction between the modified conjugated diene-based polymer and an inorganic filler, such as silica, and from the point of view of increasing processability, i, jek in formula (B) are preferably all 3.

[00256] Examples of the coupling modifier represented by formula (C) include, but are not limited to, 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.

[00257] A reaction temperature and a reaction time in the coupling step using the coupling modifier represented by formula (C), although not limited to the following, for example, the reaction is preferably carried out at 0°C or more and 120°C or less, preferably for 30 seconds or more.

[00258] The amount of coupling modifier represented by formula (C) to be added corresponds to a total number of moles of alkoxy groups linked to silyl groups of the compound represented by formula (C) of preferably 0.1 or more times and 2.0 or less times, more preferably 0.2 or more times and 1.0 or less times, and even more preferably 0.3 or more times and 0.5 or less times the number of moles of polymerization initiator being added. From the point of view of the molecular weight of a modified diene-based polymer to be obtained, the number of moles is preferably 0.1 or more times. From the point of view of long-term storage stability, the number of moles is preferably 2.0 times or less.

[00259] Examples of the coupling modifier represented by formula (D) include 3,3'-(1,1,3,3-tetramethoxydisiloxane-1,3-di-yl)bis(N,N-dimethylpropan-1-amine), Petition 870250088330, dated 09 / 29 / 2025, page 74 / 139 69 / 122 3,3'-(1,1,3,3-tetraethoxydisiloxane-1,3-di-yl) bis(N,N-dimethylpropan-1-amine), 3,3'-(1,1,3,3-tetrapropoxydisiloxane-1,3-di-yl) bis(N,N-dimethylpropan-1-amine), 3,3'-(1,1,3,3-tetramethoxydisiloxane-1,3-di-yl) bis(N,N-diethylpropan-1-amine), 3,3'-(1,1,3,3-tetramethoxydisiloxane-1,3-di-yl) bis(N,N-dipropylpropan-1-amine), and 3,3'-(1,1,3,3-tetraethoxydisiloxane-1,3-diyl)bis(N,N-diethylpropan-1-amine).

[00260] The reaction temperature and reaction time in the coupling step using the coupling modifier represented by formula (D) are not especially limited, and the reaction is preferably carried out at 0°C or more and 120°C or less, and preferably for 30 seconds or more.

[00261] The amount of coupling modifier represented by formula (D) to be added corresponds to a total number of moles of alkoxy groups linked to silyl groups of the compound represented by formula (D) of preferably 0.25 or more times and 2.0 or less times, more preferably 0.3 or more times and 1 or less times, and even more preferably 0.35 or more times and 0.5 or less times the number of moles of polymerization initiator to be added. From the point of view of the molecular weight of a modified diene-based polymer to be obtained, and from the point of view of long-term storage stability, the number of moles is preferably 2.0 times or less.

[00262] The method for producing a conjugated diene-based polymer of the present embodiment may include, after the coupling step and / or before the coupling step, a condensation reaction step to cause a condensation reaction by the addition Petition 870250088330, dated 09 / 29 / 2025, page 75 / 139 70 / 122 of a condensation accelerator.

[00263] In the present embodiment of the method for producing a conjugated diene-based polymer, after the coupling step, a deactivator and / or a neutralizer or similar may be added, if necessary, to the resulting polymer solution.

[00264] Examples of the deactivator include, but are not limited to, water and alcohols such as methanol, ethanol, and isopropanol.

[00265] Examples of neutralizers include, but are not limited to, carboxylic acids such as stearic acid, oleic acid and versicolor acid (a mixture of highly branched carboxylic acids with 9 to 11 carbon atoms and containing, as a major component, one with 10 carbon atoms), an aqueous solution of an inorganic acid and carbon dioxide gas.

[00266] From the point of view of preventing gel formation after polymerization and from the point of view of improving stability in processing, a rubber stabilizer is preferably added to the conjugated diene-based polymer of the present embodiment.

[00267] Although the rubber stabilizer is not limited to the following, any of the known ones can be used, and preferred examples include antioxidants such as 2,6-di-tert-butyl-4-hydroxytoluene (BHT), n-octadecyl-3-(4'-hydroxy-3',5'-di-tert-butylphenol)propionate and 2-methyl-4,6-bis[(octylthio)methyl]phenol.

[00268] Step for obtaining polymer from polymer solution

[00269] The method for producing a conjugated diene-based polymer of the present embodiment may include a step for obtaining the resulting conjugated diene-based polymer from the polymer solution. As a method for obtaining the conjugated diene-based polymer from the polymer solution, any of the methods Petition 870250088330, dated 09 / 29 / 2025, page 76 / 139 71 / 122 all known methods can be employed and, for example, the following methods can be employed. Examples of the method include a method in which the conjugated diene-based polymer is filtered after separation from a solvent by steam extraction or similar, and the result is dehydrated and dried to obtain the conjugated diene-based polymer; a method in which the solution is concentrated in a discharge tank, and the result is devolatilized using a curved extruder or similar to obtain the conjugated diene-based polymer; and a method in which the solution is directly devolatilized using a drum dryer or similar to obtain the conjugated diene-based polymer. Step for obtaining an extended conjugated diene-based polymer

[00270] In the present embodiment of the method for producing a conjugated diene-based polymer, at least any one selected from the group consisting of an extender oil, a liquid rubber and a resin may be added to the produced conjugated diene-based polymer to obtain an extended conjugated diene-based polymer.

[00271] Note that the extended conjugated diene-based polymer encompasses not only an extended conjugated diene-based polymer in oil containing an oil, but also a polymer containing a liquid polybutadiene or any of several resins, except an oil.

[00272] Thus, the processability of the conjugated diene-based polymer can be further improved.

[00273] As a method for adding an extender oil to the conjugated diene-based polymer, although not limited to the following, a method is preferred in which an extender oil is added to the conjugated diene-based polymer solution to be mixed, and the extended polymer solution thus obtained is desolvated. Petition 870250088330, dated 09 / 29 / 2025, p. 77 / 139 72 / 122

[00274] Examples of extender oil include an aromatic oil, a naphthenic oil, a paraffin oil, and a vegetable oil. The vegetable oil may be prepared from an oil selected from the group consisting of linseed oil, safflower oil, soybean oil, corn oil, cottonseed oil, castor oil, tung oil, pine oil, sunflower oil, palm oil, olive oil, coconut oil, peanut oil, and grapeseed oil. Among these, from the point of view of environmental safety and from the point of view of oil spill prevention and wet grip performance, an alternative aromatic oil containing 3% by mass or less of a polycyclic aromatic compound (PCA) according to IP 346 is preferred.

[00275] Examples of alternative aromatic oil include TDAE (Treated Distilled Aromatic Extracts) and MES (Soft Extraction Solvate) mentioned in Kautschuk Gummi Kunststoffe 52 (12) 799 (1999) and RAE (Residual Aromatic Extracts).

[00276] Examples of liquid rubber include, but are not limited to, liquid polybutadiene and liquid styrene-butadiene rubber.

[00277] Examples of the resin include, but are not limited to, an aromatic petroleum resin, a coumarone-indene resin, a terpene-based resin, a rosin derivative (including a wood oil resin), tall oil, a tall oil derivative, a rosin ester resin, a natural or synthetic terpene resin, an aliphatic hydrocarbon resin, an aromatic hydrocarbon resin, a mixed aliphatic / aromatic hydrocarbon resin, a coumarin-indene resin, a phenolic resin, a p-tert-butylphenol-acetylene resin, a phenol-formaldehyde resin, a xylene-formaldehyde resin, a monoolefin oligomer, a diolefin oligomer, a hydrogenated aromatic hydrocarbon resin, a cyclic aliphatic hydrocarbon resin, a hydrocarbon resin Petition 870250088330, dated 09 / 29 / 2025, pp. 78 / 139 73 / 122 hydrogenated, a hydrogenated wood oil resin, a hydrogenated oil resin and an ester of a hydrogenated oil resin and a monofunctional or polyfunctional alcohol.

[00278] One of these resins can be used alone, or two or more of them can be used together.

[00279] When this resin is hydrogenated, all unsaturated groups can be hydrogenated, or some can be left unhydrogenated.

[00280] The amount to be added of at least one selected from the group consisting of an extender oil, a liquid rubber and a resin is not particularly limited and is preferably from 1 to 60 parts by mass, more preferably from 10 to 60 parts by mass and even more preferably from 15 to 37.5 parts by mass relative to 100 parts by mass of the conjugated diene-based polymer of the present embodiment. Rubber composition

[00281] The conjugated diene-based polymer of the present embodiment can be formed into a rubber composition (hereinafter sometimes referred to as the rubber composition of the present embodiment) by adding a filler thereto.

[00282] The rubber composition of the present embodiment contains a rubber component containing the conjugated diene-based polymer of the present embodiment and 5.0 parts by mass or more and 150 parts by mass or less of a filler in relation to 100 parts by mass of the rubber component, and the rubber component preferably contains 10 parts by mass or more of the conjugated diene-based polymer of the present embodiment in relation to 100 parts by mass of the total quantity of the rubber component. When the filler is dispersed in the rubber component containing the conjugated diene-based polymer of the present embodiment Petition 870250088330, dated 09 / 29 / 2025, page 79 / 139 In the 74 / 122 embodiment, an even better rubber composition can be obtained in terms of processability in vulcanization and even better in terms of low hysteresis loss, fracture performance, and abrasion resistance of a vulcanizate obtained from it. When the rubber component contains the conjugated diene-based polymer of the present embodiment in a prescribed ratio, the low hysteresis loss, processability, and abrasion resistance tend to be further enhanced.

[00283] Examples of the filler include, but are not limited to, an inorganic silica-based filler, carbon black, a metal oxide, and a metal hydroxide. Among these, an inorganic silica-based filler is preferred. In particular, when the rubber composition of the present embodiment is used in a tire, a vehicle component such as an anti-vibration rubber, or a vulcanized rubber for footwear or similar, an inorganic silica-based filler is preferably contained. One of these fillers may be used alone, or two or more of them may be used together.

[00284] The silica-based inorganic filler is not particularly limited; any of the known fillers may be used. A solid particle containing SiO2 or SiaAl as a constituent unit is preferred, and a solid particle containing SiO2 or Si3Al as the principal component of a constituent unit is more preferable. Herein, the principal component refers to a component contained in the silica-based inorganic filler in an amount of more than 50% by mass, preferably 70% by mass or more, and most preferably 80% by mass or more.

[00285] Examples of silica-based inorganic fillers include, but are not limited to, silica, clay, talc, mica, diatomite, wollastonite, montmorillonite, zeolite, and inorganic fibrous substances such as fiber. Petition 870250088330, dated 09 / 29 / 2025, p. 80 / 139 75 / 122 glass fiber. Alternatively, an inorganic silica-based filler with a hydrophobized surface and a mixture of an inorganic silica-based filler and an inorganic filler other than silica may be used. Among these, from the point of view of further improving the strength and abrasion resistance of the rubber composition of the present embodiment, silica or glass fiber are preferred, and silica is more preferred. Silica is not particularly limited, and examples include dry silica, wet silica, and synthetic silicate. Among these silicas, wet silica is preferred from the point of view of further improving the fracture resistance of the resulting rubber composition.

[00286] From the point of view of reliably obtaining a rubber compound with practically favorable abrasion and fracture resistance, a specific nitrogen adsorption surface area of ​​the silica-based inorganic filler, as measured by the BET absorption method, is preferably 100 m² / g or more and 300 m² / g or less, and more preferably 170 m² / g or more and 250 m² / g or less. Furthermore, a silica-based inorganic filler with a comparatively small specific surface area (e.g., a specific surface area of ​​less than 200 m² / g) and a silica-based inorganic filler with a comparatively large specific surface area (e.g., 200 m² / g or more) may be used in combination, if necessary.Particularly when an inorganic silica-based filler with a comparatively large specific surface area (e.g., 200 m² / g or more) is used, the rubber composition of the present embodiment is even better in terms of silica dispersion capacity. As a result, the rubber composition tends to have excellent abrasion resistance, fracture resistance, and low hysteresis loss.

[00287] Examples of carbon black include, but are not limited to Petition 870250088330, dated 09 / 29 / 2025, p. 81 / 139 76 / 122 carbon blacks of the SRF, FEF, HAF, ISAF and SAF classes. Among these, a carbon black with a specific nitrogen adsorption surface area of ​​50 m2 / g or more and dibutyl phthalate (DBP) oil absorption of 80 mL / 100 g or less is preferred.

[00288] The metallic oxide is not especially limited, as long as it is a solid particle containing a main component of a constituent unit represented by the chemical formula MxOy (where M represents a metal atom, x and y independently represent an integer from 1 to 6), and examples include alumina, titanium oxide, magnesium oxide, and zinc oxide.

[00289] Examples of metal hydroxides include, but are not limited to, aluminum hydroxide, magnesium hydroxide, and zirconium hydroxide.

[00290] The filler content in the rubber composition of the present embodiment is preferably 5.0 parts by mass or more and 150 parts by mass or less, more preferably 20 parts by mass or more and 100 parts by mass or less, and even more preferably 30 parts by mass or more and 90 parts by mass or less in relation to 100 parts by mass of the rubber component. When the filler content satisfies this range, the rubber composition tends to be even better in terms of processability in vulcanization and even better in the property of low hysteresis loss, fracture performance and abrasion resistance of a vulcanizate thereof.

[00291] From the point of view of reliably providing the required performance for use as a tire or similar, such as dry grip and conductivity, the rubber composition of the present embodiment preferably contains 0.5 parts by mass or more and 100 parts by mass or less of carbon black relative to 100 parts by mass of the rubber component containing the Petition 870250088330, dated 09 / 29 / 2025, page 82 / 139 77 / 122 conjugated diene-based polymer of the present embodiment. From a similar point of view, the rubber composition contains carbon black in an amount more preferably of 3.0 parts by mass or more and 100 parts by mass or less, and even more preferably of 5.0 parts by mass or more and 50 parts by mass or less relative to 100 parts by mass of the rubber component containing the conjugated diene-based polymer of the present embodiment.

[00292] The rubber composition of the present embodiment may also contain a silane coupling agent. When the rubber composition contains a silane coupling agent, the interaction between the rubber component and the filler may be further enhanced.

[00293] Examples of silane coupling agents are, but are not limited to, preferably a compound containing in one molecule a sulfur linking moiety and an alkoxysilyl group or a silanol moiety. Examples of such a compound include, but are not limited to, bis-[3-(triethoxysilyl)-propyl]-tetrasulfide, bis-[3-(triethoxysilyl)-propyl]-disulfide and bis-[2-(triethoxysilyl)-ethyl]-tetrasulfide.

[00294] In the rubber composition of the present 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 part by mass or more and 15 parts by mass or less in relation to 100 parts by mass of the filler. When the content of the silane coupling agent falls within the range described above, there is a tendency for the interaction between the rubber component and the filler to be further improved.

[00295] The rubber composition of the present embodiment may contain, as a rubber component, a polymer similar to Petition 870250088330, dated 09 / 29 / 2025, page 83 / 139 78 / 122 rubber other than the conjugated diene-based polymer of the present embodiment (hereinafter simply referred to as rubber-like polymer).

[00296] Examples of rubber-like polymers include, but are not limited to, a conjugated diene-based polymer and a hydrogenated product thereof, a random copolymer of a conjugated diene-based compound and an aromatic vinyl compound and a hydrogenated product thereof, a block copolymer of a conjugated diene-based compound and an aromatic vinyl compound and a hydrogenated product thereof, a non-diene-based polymer and a natural rubber.

[00297] Examples of rubber-like polymers include, but are not limited to, butadiene rubber and a hydrogenated product thereof, isoprene rubber and a hydrogenated product thereof, styrene-based elastomers such as styrene-butadiene rubber and a hydrogenated product thereof, a styrene-butadiene block copolymer and a hydrogenated product thereof, and a styrene-isoprene block copolymer and a hydrogenated product thereof, and acrylonitrile-butadiene rubber and a hydrogenated product thereof.

[00298] Examples of non-diene-based polymers include, but are not limited to, olefin-based 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, fluorine rubber, silicone rubber, chlorinated polyethylene rubber, epichlorohydrin rubber, diene copolymer rubber conjugated with α,β-unsaturated acrylic-nitrile ester, urethane rubber and rubber of Petition 870250088330, dated 09 / 29 / 2025, page 84 / 139 79 / 122 polysulfide.

[00299] Examples of natural rubber include, but are not limited to, smoked sheets of RSS Nos. 3 to 5, SMR and epoxidized natural rubber.

[00300] The rubber-like polymer may be in the form of a modified rubber possessing a polar functional group, such as a hydroxyl group or an amino group. When the rubber composition of the present invention is used in a tire, the rubber-like polymer is preferably one or more selected from the group consisting of butadiene rubber, isoprene rubber, styrene-butadiene rubber, natural rubber, and butyl rubber.

[00301] The weight-average molecular weight of the rubber-like polymer is preferably 2,000 or more and 2,000,000 or less, and more preferably 5,000 or more and 1,500,000 or less from the points of view of abrasion resistance, fracture resistance and balance between a low hysteresis loss property and processability of the resulting rubber composition. As with the rubber-like polymer, a low molecular weight rubber-like polymer, i.e., what is called liquid rubber, can be used. One of these rubber-like polymers can be used alone, or two or more of them can be used together.

[00302] When the rubber composition of the present embodiment contains the rubber-like polymer in addition to the conjugated diene-based polymer of the present embodiment, a content ratio (in a mass ratio) between the conjugated diene-based polymer and the rubber-like polymer is, in terms of (the conjugated diene-based polymer / the rubber-like polymer), preferably 10 / 90 or more and 100 / 0 or less, more preferably 20 / 80 or more and 99 / 1 or less, and even more preferably 30 / 70 or more and 95 / 5 or less. Petition 870250088330, dated 09 / 29 / 2025, p. 85 / 139 80 / 122 nos. In other words, the rubber component contains, in relation to 100 parts by mass of the total quantity of the rubber component, preferably 10 parts by mass or more and 100 parts by mass or less, more preferably 20 parts by mass or more and 90 parts by mass or less, and even more preferably 30 parts by mass or more and 80 parts by mass or less of the conjugated diene-based polymer of the present embodiment. When the ratio of the conjugated diene-based polymer of the present embodiment contained in the rubber component falls within the range described above, a vulcanizate of the rubber composition tends to be even better in terms of abrasion resistance and low hysteresis loss property.

[00303] A rubber softener may be added to the rubber composition of the present embodiment in addition to the rubber component, in order to further improve processability.

[00304] Like rubber softeners, the same ones described as examples to be contained in the conjugated diene-based polymer described above can be used, a mineral oil or a low molecular weight liquid or synthetic softener being suitable.

[00305] A mineral oil-based rubber softener, which is used to soften, expand, and improve the processability of a rubber component and is designated as process oil or extender oil, is a mixture of an aromatic ring, a naphthenic ring, and a paraffin chain. In particular, one in which the number of carbon atoms in the paraffin chain is 50% or more is designated as a paraffin-based softener, one in which the number of carbon atoms in the naphthenic ring is 30% or more and 45% or less is designated as a naphthenic-based softener, and one in which the number of carbon atoms belonging to aromatic carbons exceeds 30% of the number of all carbon atoms is designated as an aromatic-based softener. The composition Petition 870250088330, dated 09 / 29 / 2025, p. 86 / 139 81 / 122 of the rubber composition of the present embodiment preferably contains, as a rubber softener, one that has an appropriate aromatic content. When such a rubber softener is present, the compatibility with the conjugated diene-based polymer is further enhanced.

[00306] The rubber softener content in the rubber composition of the present embodiment is expressed as a sum of the amount of rubber softener previously added to the conjugated diene-based polymer or rubber-like polymer and the amount of rubber softener added in the formation of the rubber composition.

[00307] In the rubber composition of the present embodiment, the content of the rubber softener is preferably 0 parts by mass or more and 100 parts by mass or less, more preferably 10 parts by mass or more and 90 parts by mass or less, and even more preferably 30 parts by mass or more and 90 parts by mass or less in relation to 100 parts by mass of the rubber component. When the content of the rubber softener is 100 parts by mass or less in relation to 100 parts by mass of the rubber component, bleeding can be suppressed, and the stickiness of the surface of the rubber composition can be further suppressed.

[00308] The rubber composition may be produced by mixing the conjugated diene-based polymer, the rubber-like polymer, the filler, the silane coupling agent, the rubber softener, and the like. The mixing method is not particularly limited, and examples include a melt kneading method using a general mixer, such as an open roll, a Banbury mixer, a kneader, a single-shaft screw extruder, a twin-shaft screw extruder, or a multi-shaft screw extruder, and a method in which the respective components are melted and mixed, followed by the removal of a solvent by heating. Petition 870250088330, dated 09 / 29 / 2025, page 87 / 139 82 / 122 Among these methods, the melt kneading method using a roller, a Banbury mixer, a kneader, or an extruder is preferred from the point of view of productivity and high kneading capacity. Furthermore, the rubber component, filler, silane coupling agent, and additive can all be kneaded together or mixed separately in several batches.

[00309] The rubber composition of the present embodiment may be in the form of a vulcanizate obtained by vulcanization with a vulcanizing agent. The vulcanizing agent is not particularly limited, and examples include radical generators such as organic peroxides and azo compounds, oxime compounds, nitroso compounds, polyamine compounds, sulfur and sulfur compounds. Sulfur compounds include sulfur monochloride, sulfur dichloride, disulfide compounds, high molecular weight polysulfide compounds and the like.

[00310] In the rubber composition of the present embodiment, the content of the vulcanizing agent is preferably 0.01 parts by mass or more and 20 parts by mass or less, and more preferably 0.1 parts by mass or more and 15 parts by mass or less in relation to 100 parts by mass of the rubber component. As a method of vulcanization, any of the conventionally known methods may be employed. A vulcanization temperature is preferably 120°C or more and 200°C or less, and more preferably 140°C or more and 180°C or less.

[00311] For the vulcanization of the rubber composition, a vulcanization accelerator and / or a vulcanization aid may be used, if necessary. As the vulcanization accelerator, any of the conventionally known materials may be used, and examples include, but are not limited to, sulfenamide-based, guanidine-based, and thiuram-based vulcanization accelerators. Petition 870250088330, dated 09 / 29 / 2025, page 88 / 139 83 / 122 based on aldehyde-amine, aldehyde-ammonia, thiazole, thiourea and dithiocarbamate.

[00312] In addition, examples of vulcanizing aids include, but are not limited to, zinc oxide and stearic acid.

[00313] The contents of the vulcanization accelerator and the vulcanization auxiliary are, respectively, preferably 0.01 parts by mass or more and 20 parts by mass or less, and more preferably 0.1 parts by mass or more and 15 parts by mass or less in relation to 100 parts by mass of the rubber component.

[00314] In the rubber composition of the present embodiment, provided that the effects of the present embodiment are not impaired, various additives, such as another softener and filler, excluding those described above, a heat resistance stabilizer, an antistatic agent, a weathering stabilizer, an anti-aging agent, a dye and a lubricant may be used. Any known softener may be used as a softener.

[00315] Examples of fillers, excluding those described above, include, but are not limited to, calcium carbonate, magnesium carbonate, aluminum sulfate, and barium sulfate. As heat-resistant stabilizers, antistatic agents, weathering stabilizers, anti-aging agents, colorants, and lubricants, any of the known materials may be used, respectively.

[00316] The rubber compound of the present embodiment is suitably used as a rubber compound for a tire. The rubber compound of the present embodiment can be suitably used in, but not especially limited to, various tires, such as a fuel-efficient tire, an all-season tire, a high-performance tire, and a studless tire; and various tire parts, such as tread, carcass, sidewall, and bead. Petition 870250088330, dated 09 / 29 / 2025, p. 89 / 139 84 / 122

[00317] Note that each numerical range described above as a preferred or similar range may be a numerical range obtained by the arbitrary combination of any of the values ​​described as upper limits and any of the values ​​described as lower limits, even when not specifically stated. Examples

[00318] The present embodiment will now be described in more detail with reference to specific examples and comparative examples, and it is noted that the present invention is not limited to the following examples and comparative examples.

[00319] Several physical properties of the examples and comparative examples were measured by the following methods.

[00320] (Physical Property 1) Amount of bonded aromatic vinyl monomer unit (amount of bonded styrene)

[00321] Amount of Styrene Bound Xtotal in the Conjugated Diene-Based Polymer

[00322] A conjugated diene-based polymer containing no rubber softener was used as a sample, and 100 mg of the sample were diluted to 100 mL with chloroform and dissolved to obtain a measurement sample.

[00323] The amount of bound styrene (% by mass) in 100% by mass of the conjugated diene-based polymer used as a sample was measured by measuring the amount of absorption at an ultraviolet absorption wavelength (in the vicinity of 254 nm) by a phenyl group of styrene (measuring instrument: UV-2450 spectrophotometer manufactured by Shimadzu Corporation). Amount of styrene bound X1 in the first polymer segment

[00324] The amount of styrene bound in the first polymer segment was calculated in the same way as that used for the amount of styrene bound in a segment of the polymer based on Petition 870250088330, dated 09 / 29 / 2025, pp. 90 / 139 85 / 122 diene conjugate, except that the sample was changed from the diene conjugate-based polymer to the first polymeric segment. Amount of styrene bound X2 in the second polymer segment

[00325] A segment ratio (n) of the first polymer segment and a segment ratio (r2) of the second polymer segment were calculated by a method described below, and an amount of styrene bound Xaii in the conjugated diene-based polymer and the amount of styrene bound X1 in the first polymer segment calculated based on the measurement were used to calculate the amount of styrene bound (X2) in the second polymer segment according to the following expression (9): ΙΟΟΧ,ιι-ηΧ. X=-----a1 1(9) Í2 (Physical property 2) Amount of vinyl linkage in the conjugated diene (amount of 1,2-vinyl linkage in the butadiene) Amount of vinyl linkage Ytotai in the conjugated diene-based polymer

[00326] A conjugated diene polymer that did not contain rubber softener was used as a sample, and 50 mg of the sample were dissolved in 10 mL of carbon disulfide to obtain a measurement sample.

[00327] An infrared spectrum of each sample was measured in a range of 600 to 1,000 cm-1 using a Fourier transform infrared spectrophotometer (trade name FT-IR230 manufactured by JASCO Corporation).

[00328] According to Hampton's method (method described by RR Hampton, Analytical Chemistry 21, 923 (1949)), an amount of 1,2-vinyl bonding (mol%) in bonded butadiene was obtained based on absorbance at a prescribed wavelength. Petition 870250088330, dated 09 / 29 / 2025, pp. 91 / 139 86 / 122 Amount of vinyl linkage Yi in the first polymer segment

[00329] The amount of vinyl linkage in the first polymer segment was calculated in the same way as that used for the amount of vinyl linked in a conjugated diene polymer, except that the sample was changed from conjugated diene polymer to the first polymer segment.

[00330] In the Tables, when the numerical range of Expression (2) was satisfied, O was shown, and when not, x was shown. Amount of vinyl linkage Y2 in the second polymer segment

[00331] A segment ratio (n) of the first polymer segment and a segment ratio (r2) of the second polymer segment were calculated by a method described below, and the amount of styrene linked Xtotai in the conjugated diene-based polymer, the amount of styrene linked X1 in the first polymer segment, the amount of styrene linked X2 in the second polymer segment, the amount of vinyl linkage Ytotai in the conjugated diene-based polymer and the amount of vinyl linkage Y1 in the first polymer segment, all calculated based on measurement, were used to calculate the amount of vinyl linkage Y2 in the second polymer segment according to the following expression (10): (1 0 0-Xall)x YallX l 0 0-(1 0 0-X , )x Y, X n ( 1 0 Q-Xs )χ Γ2 •••(10) (Physical Property 3) Ratio of the polymeric segment Ratio of the first polymeric segment n

[00332] A ratio of the first polymer segment was calculated using the following expression (11).

[00333] A ratio of a polymer segment in the first polymerization step (P1) of producing a first polymer segment was calculated based on the solids content of the diene-based polymer. Petition 870250088330, dated 09 / 29 / 2025, pp. 92 / 139 87 / 122 conjugated by time after the first polymerization step (P1) in relation to the total amount of conjugated diene compound and aromatic vinyl compound added by time to polymerize the conjugated diene-based polymer.

[00334] The solids content in the conjugated diene-based polymer solution was obtained based on the amount of a non-volatile component in the polymer solution flowing through a discharge port of the first polymerization stage (P1) in a unit of time.

[00335] The total amount of polymer solution flowing through the discharge port of the first polymerization stage (P1) was collected for 3 minutes, and immediately after that, a polymerization terminator was added. Then, the collected solution was transferred to a heat-resistant dish or similar, and a mass M1 of a solid remaining after drying the result in an oven at 140°C for 30 minutes or more was measured.

[00336] Here, a solids content m1 and the ratio of the first polymeric segment (n) were obtained according to the following expression (11). Ratio of the first polymeric segment r1 (%) Solids content ml[g / min] total amount of conjugated diene compound added [g / min] + total amount of aromatic vinyl compound added [g / min] Mass M1 of solid [g / min] + 3 conjugated diene compound added to the first reactor [g / min] + aromatic vinyl compound added to the first reactor [g / min] + conjugated diene compound added to the second reactor [g / min] + aromatic vinyl compound added to the second reactor [g / min] Ratio of the second polymeric segment r2

[00337] A ratio of the second polymer segment (r2) was calculated using the following expression (12).

[00338] The ratio of the second polymer segment in the second polymerization step (P2) of second polymer segment formation was calculated based on the difference between the solids content of the polymer. Petition 870250088330, dated 09 / 29 / 2025, pp. 93 / 139 88 / 122 based on conjugated diene by time after the second polymerization step (P2) and the solids content of the conjugated diene-based polymer by time after the first polymerization step (P1) in relation to the total amount of conjugated diene compound and aromatic vinyl compound added by time to polymerize the conjugated diene-based polymer.

[00339] The solids content in the conjugated diene-based polymer solution was obtained based on the amount of a non-volatile component in the polymer solution flowing through a discharge port of the second polymerization stage (P2) in a unit of time.

[00340] The total amount of polymer solution flowing through the discharge port of the second polymerization stage (P2) was collected for 3 minutes and, immediately after that, a polymerization terminator was added. Then, the collected solution was transferred to a heat-resistant plate or similar, and a mass M2 of a solid remaining after drying the resultant in an oven at 140°C for 30 minutes or more was measured. Based on the mass M1 of the solid obtained in the first polymerization stage (P1) described above and the mass M2 of the solid, the ratio of the second polymer segment Γ2 was obtained according to the following expression (12). Ratio of the second polymeric segment r2 (%) Solids content m2 [g / min] - solids content m1 [g / min] total amount of conjugated diene compound added [g / min] + total amount of aromatic vinyl compound added [g / min] mass M2 of solid (g / 3 min) + 3 - mass m1 of solid (g / 3 min) 4- 3 conjugated diene compound added to the first reactor (g / min) + aromatic vinyl compound added to the first reactor (g / min) + conjugated diene compound added to the second reactor (g / min) + (1 D aromatic vinyl compound added to the second reactor (g / min) (Physical Property 4) Estimated glass transition temperature

[00341] The estimated glass transition temperature of a conjugated diene-based polymer was obtained using expression (iii). (Physical Property 5) Molecular Weight Petition 870250088330, dated 09 / 29 / 2025, pp. 94 / 139 89 / 122

[00342] A conjugated diene-based polymer was used as a sample to measure a chromatogram using a GPC measuring instrument (trade name HLC-8320GPC manufactured by Tosoh Corporation), including a series of three columns using a polystyrene-based gel as packing and an RI detector (trade name HLC8020 manufactured by Tosoh Corporation). Based on a calibration curve obtained using standard polystyrene, a weight-average molecular weight (Mw), a number-average molecular weight (Mn), and a molecular weight distribution (Mw / Mn) were obtained.

[00343] THF (tetrahydrofuran) containing 5 mmol / L of triethylamine was used as an eluent.

[00344] The TSKguardcolumn Super MP(HZ)-H trademark, manufactured by Tosoh Corporation, was used as a protective column in an earlier stage, connected to a series of three TSKgel Super Multipore HZ-H trademark columns, also manufactured by Tosoh Corporation.

[00345] Ten (10) mg of a sample for measurement were dissolved in 10 mL of THF to obtain a measurement solution, and 10 μL of the measurement solution were injected into the GPC measuring apparatus to perform the measurement under conditions of a furnace temperature of 40°C and a THF flow rate of 0.35 mL / min. (Physical Property 6) Mooney viscosity of the polymer

[00346] A conjugated diene-based polymer was used as a sample to measure Mooney viscosity using a Mooney viscometer (trade name VR1132 manufactured by Ueshima Seisakusho Co., Ltd.) according to ISO 289 standard with an L-type rotor used and with a measurement temperature set to 100°C.

[00347] After the sample was preheated to the test temperature for 1 minute, the rotor was rotated at 2 rpm and a torque was measured 4 minutes later to measure the Mooney viscosity (ML(1 4)). Petition 870250088330, dated 09 / 29 / 2025, pp. 95 / 139 90 / 122 (Physical Property 7) Glass Transition Temperature (Tg)

[00348] When a conjugated diene-based polymer was an oil-extended product, the conjugated diene-based polymer after the extension oil extraction was used as a sample, and according to ISO 22768: In 2006, a heating DSC curve was recorded with a Mac Science-manufactured DSC 3200S differential scanning calorimeter with the temperature decreased from 20°C at 20°C / min to -120°C and increased from -120°C at 10°C / min under a 50 mL / min helium flow rate. Then, only one inflection point observed in the heating DSC curve between -100°C and -20°C was determined as the glass transition temperature.

[00349] An extrapolated initial temperature was determined as a temperature at a point of intersection between a straight line drawn extending, towards the high-temperature side, the baseline on the low-temperature side and a tangent line drawn at a point corresponding to the maximum gradient of a curve of a gradually changing portion of the glass transition.

[00350] An extrapolated final temperature was determined as a temperature at a point of intersection between a straight line drawn extending, towards the low-temperature side, the baseline on the high-temperature side and the tangent line drawn at the point corresponding to the maximum gradient of the gradual change portion of the glass transition curve. (Physical Property 8) Modification Rate

[00351] A modification ratio of a conjugated diene-based polymer from each of the Examples and Comparative Examples was measured by adsorption on a GPC column as follows.

[00352] A conjugated diene-based polymer was used as a sample to perform measurements using a characteristic whereby a modified basic polymer component adsorbs onto a co Petition 870250088330, dated 09 / 29 / 2025, pp. 96 / 139 91 / 122 GPC luna using a silica-based gel as filler.

[00353] Based on the difference between a chromatogram obtained by measurement with a polystyrene-based column and a chromatogram obtained by measurement with a silica-based column, which were obtained from a sample solution containing the sample and the internal standard of low molecular weight polystyrene, the amount of absorption on the silica-based column was measured to obtain a modification ratio.

[00354] Sample solution preparation:

[00355] 10 mg of the sample and 5 mg of standard polystyrene were dissolved in 20 mL of THF (tetrahydrofuran) to obtain the sample solution.

[00356] GPC measurement conditions using a polystyrene-based column:

[00357] Using an instrument with the commercial name HLC-8320GPC manufactured by Tosoh Corporation, and with THF containing 5 mmol / L triethylamine used as eluent, 10 μL of the sample solution were injected into the instrument to obtain a chromatogram with an RI detector under conditions of a column oven temperature of 40°C and a THF flow rate of 0.35 mL / min.

[00358] As columns, a series of three TSKgel Super Multipore HZ-H columns manufactured by Tosoh Corporation were connected with a TSKguardcolumn SuperMP(HZ)-H column manufactured by Tosoh Corporation connected as a protective column at an earlier stage. GPC measurement conditions using a silica-based column

[00359] The GPC measurement was performed using a device with the commercial name HLC-8320GPC manufactured by Tosoh Corporation and an RI detector (commercial name HLC8020 manufactured by Tosoh Corporation).

[00360] THF was used as the eluent, and 50 pL of a solution of Petition 870250088330, dated 09 / 29 / 2025, pp. 97 / 139 Sample 92 / 122 was injected into the GPC apparatus to obtain a chromatogram under column oven temperature conditions of 40°C and a THF flow rate of 0.5 mL / min.

[00361] A series of columns with the trade names Zorbax PSM-1000S, PSM-300S and PSM-60S manufactured by Agilent Technologies Japan Ltd., and a shielding column with the trade name DIOL 4.6 x 12.5 mm 5 microns connected in a previous stage were used.

[00362] Calculation method for modification ratio:

[00363] In the chromatogram obtained using the polystyrene-based column, it was assumed that the entire peak area was 100, that the peak area of ​​the sample was p1, that the peak area of ​​the standard polystyrene was p2, and in the chromatogram obtained using the silica-based column, it was assumed that the entire peak area was 100, that the peak area of ​​the sample was p3, and that the peak area of ​​the standard polystyrene was p4, and thus, a modification ratio (%) was obtained based on the following expression: Change rate (%) = [1 - (p2 x p3) / (p1 χ p4)] x 100 where p1 + p2 = p3 + p4 = 100. Production of polymer based on conjugated diene Example 1

[00364] Two tank pressure vessels, each of which was a tank reactor fitted with a stirrer with an internal volume of 10 L and an internal height (L) to diameter (D) ratio of 4.0, having an inlet at the bottom and an outlet at the top, and fitted with a stirrer and a temperature control jacket, were connected to each other as a polymerization reactor.

[00365] 1,3-butadiene and normal hexane, from which the water content had been previously removed, were mixed under conditions of 18.8 g / min and 163.4 g / min, respectively, to obtain a solution Petition 870250088330, dated 09 / 29 / 2025, pp. 98 / 139 93 / 122 mixed. N-butyllithium for inactivation of residual impurities was added at 0.104 mmol / min in a static mixer provided in the middle of a tube to supply this mixed solution to the reactor inlet, and the resulting mixture was then continuously fed to the bottom of the reactor. Additionally, 2,2-bis(2-oxolanyl)propane, used as a polarizing material, and n-butyllithium, used as a polymerization initiator, were fed at rates of 0.027 mmol / min and 0.239 mmol / min, respectively, to the bottom of the first reactor, where these substances were vigorously stirred with the stirrer, and the internal temperature of the reactor was maintained at 78°C. After the polymerization reaction was stabilized, a small amount of a conjugated diene-based polymer was removed from the top of the reactor, and an antioxidant (BHT) was added to it to obtain a quantity of 0.2 g per 100 g of polymer.Next, the solvent was removed and the amount of vinyl linkage (Yi) in the conjugated diene bonded from a first polymeric segment was measured.

[00366] Next, the polymer solution was continuously supplied from the top of the first reactor to the bottom of the second reactor and, for the second reactor, 1,3-butadiene, styrene, normal hexane and 2,2-bis(2-oxolanyl)propane used as polar material were stirred, respectively, at rates of 10.6 g / min, 4.5 g / min, 41.9 g / min and 0.415 mmol / min, and the reaction continued at 78°C.

[00367] Next, to the polymer solution that flowed out of the top of the second reactor, 1-methyl-4-[3-(trimethoxysilyl)propyl]piperazine (shown as Coupling Agent A in the Tables) and tetracis(3-trimethoxysilylpropyl)-1,3-propanediamine (shown as Coupling Agent B in the Tables) were continuously added as coupling agents, respectively, at rates of 0.097 mmol / min and 0.010 mmol / min, and the resulting mixture was stirred with the static mixer to cause a coupling reaction. Here, the Petition 870250088330, dated 09 / 29 / 2025, pp. 99 / 139 94 / 122 The time until the addition of the coupling agent to the polymer solution flowing out of the reactor outlet was 4.8 min, the temperature was 68°C, and the difference between the temperature during the polymerization step and the temperature before the addition of the coupling agent was 2°C.

[00368] A small amount of the conjugated diene-based polymer solution was removed after the coupling reaction, an antioxidant (BHT) was added to it to obtain an amount of 0.2 g per 100 g of polymer, and then the solvent was removed and the amount of styrene bonded (X), the amount of vinyl bond (Y), the glass transition temperature, and the extrapolated initial and final temperatures were identified.

[00369] Next, an antioxidant (BHT) was added continuously at 0.055 g / min (in the form of an n-hexane solution) to the polymer solution after the coupling reaction to obtain an amount of 0.2 g per 100 g of polymer, and thus the coupling reaction was completed. Simultaneously with the antioxidant, an SRAE oil (JOMO Process NC 140, manufactured by JX Nippon Oil & Energy Corporation) was added continuously as a rubber softener to obtain an amount of 5.0 g per 100 g of polymer, and the resulting mixture was mixed with the static mixer.

[00370] The solvent was removed by steam extraction, and thus a conjugated diene-based polymer (A1) was obtained. The molecular weight, Mooney viscosity, and modification ratio of the same were identified. Example 2

[00371] To the first reactor, 1,3-butadiene and normal hexane were added under conditions of 15.8 g / min and 156.0 g / min, respectively, and 2,2-bis(2-oxolanyl)propane was added as a polar material at a rate of 0.072 mmol / min, and to the second reactor, 1,3-butadiene, styrene, normal hexane and 2,2-bis(2-oxolanyl)propane were used as Petition 870250088330, dated 09 / 29 / 2025, pp. 100 / 139 95 / 122 polar material were added at rates of 14.0 g / min, 4.4 g / min, 49.9 g / min, and 0.370 mmol / min, respectively. Except for these conditions, the same conditions employed in Example 1 were used to obtain a conjugated diene-based polymer (A2). Example 3

[00372] To the first reactor, 1,3-butadiene and normal hexane were added at rates of 19.8 g / min and 165.6 g / min, respectively, and 2,2-bis(2-oxolanyl)propane was added as a polar material at a rate of 0.145 mmol / min, and to the second reactor, 1,3-butadiene, styrene, normal hexane and 2,2-bis(2-oxolanyl)propane used as a polar material were added at rates of 7.2 g / min, 4.2 g / min, 33.2 g / min and 0.253 mmol / min, respectively, and the internal temperature of the second reactor was adjusted to 78°C. Except for these conditions, the same conditions employed in Example 1 were used to obtain a conjugated diene-based polymer (A3). Example 4

[00373] To the first reactor, 1,3-butadiene and normal hexane were added at rates of 18.8 g / min and 163.4 g / min, respectively, and 2,2-bis(2-oxolanyl)propane was added as a polar material at a rate of 0.023 mmol / min, and the internal temperature of the first reactor was set to 82°C. To the second reactor, 1,3-butadiene, styrene, normal hexane, and 2,2-bis(2-oxolanyl)propane used as a polar material were added at rates of 11.2 g / min, 5.3 g / min, 44.8 g / min, and 0.153 mmol / min, respectively. Except for these conditions, the same conditions employed in Example 1 were used to obtain a conjugated diene-based polymer (A4). Example 5

[00374] 1-Methyl-4-[3-(trimethoxysilyl)propyl]piperazine (shown as Coupling Agent A in the Tables) and tetracis(3-trimethoxysilylpropyl)-1,3-propanediamine (shown as Agent Petition 870250088330, dated 09 / 29 / 2025, pp. 101 / 139 96 / 122 of Coupling B in Tables) were added continuously as a coupling agent, respectively, at rates of 0.110 mmol / min and 0.007 mmol / min. Except for these conditions, the same conditions employed in Example 1 were used to obtain a conjugated diene-based polymer (A5). Example 6

[00375] To the first reactor, n-butyllithium was added as a polymerization initiator at 0.193 mmol / min, 2,2-bis(2-oxolanyl)propane was added as a polar material at 0.019 mmol / min, and to the second reactor, 2,2-bis(2-oxolanyl)propane was added at 0.298 mmol / min, and no coupling agent was added. Except for these conditions, the same conditions employed in Example 1 were used to obtain a conjugated diene-based polymer (A6). Example 7

[00376] To the first reactor, n-butyllithium was added as a polymerization initiator at 0.343 mmol / min, 2,2-bis(2-oxolanyl)propane was added as a polar material at 0.033 mmol / min, and to the second reactor, 2,2-bis(2-oxolanyl)propane was added at 0.596 mmol / min, and 1-methyl-4-[3-(trimethoxysilyl)propyl]piperazine (shown as Coupling Agent A in the tables) was continuously added as a coupling agent at a rate of 0.173 mmol / min. Except for these conditions, the same conditions employed in Example 1 were used to obtain a conjugated diene-based polymer (A7). Example 8

[00377] To the first reactor, n-butyllithium was added as a polymerization initiator at 0.198 mmol / min, 2,2-bis(2-oxolanyl)propane was added as a polar material at 0.019 mmol / min, and to the second reactor, 2,2-bis(2-oxolanyl)propane was added at 0.298 mmol / min, and 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane (shows Petition 870250088330, dated 09 / 29 / 2025, pp. 102 / 139 97 / 122 of the Coupling Agent C in the Tables) was added continuously as a coupling agent at a rate of 0.052 mmol / min. Except for these conditions, the same conditions employed in Example 1 were used to obtain a conjugated diene-based polymer (A8). Example 9

[00378] To the first reactor, n-butyllithium was added as a polymerization initiator at 0.130 mmol / min, 2,2-bis(2-oxolanyl)propane was added as a polar material at 0.015 mmol / min, and to the second reactor, 2,2-bis(2-oxolanyl)propane was added at 0.235 mmol / min, tetracis(3-trimethoxysilylpropyl)-1,3-propanediamine (shown as Coupling Agent B in the Tables) was added continuously as a coupling agent at a rate of 0.017 mmol / min, and an SRAE oil (JOMO Process NC 140, manufactured by JX Nippon Oil & Energy Corporation) was added continuously as a rubber softener to obtain an amount of 25.0 g per 100 g of polymer. Except for these conditions, the same conditions employed in Example 1 were employed to obtain a conjugated diene-based polymer (A9). Example 10

[00379] 1,3-butadiene and styrene were added to the second reactor and normal hexane was added to the second reactor, respectively, at rates of 13.8 g / min, 2.7 g / min and 46.6 g / min continuously. Except for these conditions, the same conditions employed in Example 4 were employed to obtain a conjugated diene-based polymer (A10). Example 11

[00380] 2,2-bis-(2-oxolanyl)propane was added as a polar material to the first reactor and 2,2-bis(2-oxolanyl)propane was added to the second reactor, respectively, at rates of 0.266 mmol / min and 0.176 mmol / min. Petition 870250088330, dated 09 / 29 / 2025, pp. 103 / 139 98 / 122 mmol / min continuously. Except for these conditions, the same conditions employed in Example 1 were used to obtain a conjugated diene-based polymer (A11). Example 12

[00381] To the first reactor, 1,3-butadiene and styrene were added simultaneously at rates of 13.8 g / min and 4.4 g / min, respectively, normal hexane was added at a rate of 104.8 g / min, 2,2-bis(2-oxolanyl)propane was added as a polar material at a rate of 0.003 mmol / min, and the internal temperature of the first reactor was set to 65°C.Furthermore, 1,3-butadiene was added to the second reactor at a rate of 2.9 g / min, no additional styrene was added, normal hexane and 2,2-bis(2-oxolanyl)propane as additional polar material were added, respectively, at rates of 9.5 g / min and 0.020 mmol / min, the internal temperature of the second reactor was adjusted to 65°C, and 1-methyl-4-[3-(trimethoxysilyl)propyl]piperazine (shown as Coupling Agent A in the Tables) and tetracis(3-trimethoxysilylpropyl)-1,3-propanediamine (shown as Coupling Agent B in the Tables) were continuously added as the coupling agent, respectively, at rates of 0.087 mmol / min and 0.009 mmol / min. Except for these conditions, the same conditions employed in Example 1 were used to obtain a conjugated diene-based polymer (A12). Example 13

[00382] n-Butyllithium was added to the first reactor as a polymerization initiator, and 2,2-bis(2-oxolanyl)propane was added as a polar material, respectively at 0.370 mmol / min and 0.036 mmol / min, and 2,2-bis(2-oxolanyl)propane was added to the second reactor at 0.641 mmol / min. Except for these conditions, the same conditions employed in Example 7 were used to obtain a conjugated diene-based polymer (A13). Petition 870250088330, dated 09 / 29 / 2025, pp. 104 / 139 99 / 122 Example 14

[00383] To the first reactor, n-butyllithium was added as a polymerization initiator, and 2,2-bis(2-oxolanyl)propane was added as a polar material, respectively, at 0.062 mmol / min and 0.007 mmol / min, and to the second reactor, 2,2-bis(2-oxolanyl)propane was added at 0.094 mmol / min, tetracis(3-trimethoxysilylpropyl)-1,3-propanediamine (shown as Coupling Agent B in the Tables) was added continuously as a coupling agent at a rate of 0.008 mmol / min, and an SRAE oil (JOMO Process NC 140, manufactured by JX Nippon Oil & Energy Corporation) was added continuously as a rubber softener to obtain an amount of 37.5 g per 100 g of polymer. Except for these conditions, the same conditions employed in Example 9 were used to obtain a conjugated diene-based polymer (A14). Example 15

[00384] To the first reactor, 1,3-butadiene and normal hexane were added under conditions of 21.4 g / min and 170.3 g / min, respectively, and 2,2-bis(2-oxolanyl)propane was added as a polar material at 0.054 mmol / min, and to the second reactor, 1,3-butadiene, styrene, normal hexane and 2,2-bis(2-oxolanyl)propane were continuously added, respectively, at 9.2 g / min, 3.5 g / min, 36.8 g / min and 0.394 mmol / min. Except for these conditions, the same conditions employed in Example 1 were used to obtain a conjugated diene-based polymer (A15). Example 16

[00385] To the first reactor, 1,3-butadiene and normal hexane were added under conditions of 15.4 g / min and 166.0 g / min, respectively, and 2,2-bis(2-oxolanyl)propane was added as a polar material at 0.072 mmol / min, and to the second reactor, 1,3-butadiene, styrene, normal hexane and 2,2-bis(2-oxolanyl)propane were continuously added. Petition 870250088330, dated 09 / 29 / 2025, page 105 / 139 100 / 122 onados, respectively, at 12.6 g / min, 5.3 g / min, 48.2 g / min and 0.340 mmol / min and a polymerization temperature in the second reactor of 80°C. Except for these conditions, the same conditions employed in Example 1 were used to obtain a conjugated diene-based polymer (A16). Example of reference 1

[00386] To the first reactor, 1,3-butadiene and styrene were added simultaneously at 22.3 g / min and 4.2 g / min, respectively, normal hexane was added at 178.8 g / min, 2,2-bis(2-oxolanyl)propane was added as a polar material at a rate of 0.101 mmol / min, and the internal temperature of the first reactor was set to 68°C, and to the second reactor, 1,3-butadiene was added at 7.4 g / min, no additional styrene was added, normal hexane was added at 26.7 g / min, no additional polar material was added, and the internal temperature of the second reactor was set to 73°C. Except for these conditions, the same conditions employed in Example 1 were used to obtain a conjugated diene-based polymer (B1). Comparative example 1

[00387] A conjugated diene-based polymer (B2) was obtained in the same manner as in Example 1, except that 2,2-bis(2-oxolanyl)propane was added as a polar material to the first reactor at a rate of 0.266 mmol / min, and that 1,3-butadiene, additional styrene, normal hexane and 2,2-bis(2-oxolanyl)propane as an additional polar material were added to the second reactor, respectively, at rates of 9.7 g / min, 5.4 g / min, 41.3 g / min and 0.156 mmol / min. Comparative example 2

[00388] The coupling agent addition step was not performed. Except for this, the same conditions employed in Exem Petition 870250088330, dated 09 / 29 / 2025, pp. 106 / 139 101 / 122 Reference Example 1 were used to obtain a conjugated diene-based polymer (B3). Comparative example 3

[00389] A diene-based conjugated polymer (B4) was obtained in the same manner as in Reference Example 1, except that n-butyllithium was added as a polymerization initiator to the first reactor at 0.343 mmol / min, that 2,2-bis(2-oxolanyl)propane was added as a polar material at 0.124 mmol / min, that normal hexane was added as a coupling agent at 109.2 g / min, and that 1-methyl-4-[3-(trimethoxysilyl)propyl]piperazine (shown as Coupling Agent A in the Tables) was added continuously at a rate of 0.173 mmol / min. Comparative example 4

[00390] A conjugated diene-based polymer (B5) was obtained in the same manner as in Reference Example 1, except that n-butyllithium was added as a polymerization initiator to the first reactor at 0.198 mmol / min, and 2,2-bis(2-oxolanyl)propane was added as a polar material at 0.070 mmol / min, and 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane (shown as Coupling Agent C in the Tables) was added continuously as a coupling agent at 0.052 mmol / min, and an SRAE oil (JOMO Process NC 140, manufactured by JX Nippon Oil & Energy Corporation) was then added continuously as a rubber softener to obtain an amount of SRAE oil of 25.0 g per 100 g of polymer. Comparative example 5

[00391] A conjugated diene-based polymer (B6) was obtained in the same manner as in Reference Example 1, except that n-butyllithium was added as a polymerization initiator to the first reactor at 0.130 mmol / min, and 2,2-bis(2-oxolanyl)propane was added. Petition 870250088330, dated 09 / 29 / 2025, pp. 107 / 139 102 / 122 as a polar material at 0.055 mmol / min, that tetracis(3-trimethoxysilyl propyl)-1,3-propanediamine (shown as Coupling Agent B in the Tables) was added continuously as a coupling agent at a rate of 0.017 mmol / min, and that an SRAE oil (JOMO Process NC 140, manufactured by JX Nippon Oil & Energy Corporation) was then added continuously as a rubber softener to obtain an amount of SRAE oil of 37.5 g per 100 g of polymer. Petition 870250088330, dated 09 / 29 / 2025, pp. 108 / 139 Table 1 Sample no. Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 A1 A2 A3 A4 A5 A6 A7 n-Butyllithium polymerization conditions for treatment (mmol / min) 0.104 0.104 0.104 0.104 0.104 0.104 0.104 n-Butyllithium polymerization initiator (mmol / min) 0.239 0.239 0.239 0.239 0.239 0.193 0.343 Butadiene added to the 1st Reactor (g / min) 18.8 15.8 19.8 18.8 18.8 18.8 18.8 Styrene added to the 1st Reactor (g / min) 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Normal hexane added to the 1st Reactor (g / min) 163.4 156.0 165.6 163.4 163.4 163.4 163.4 Polar material added to the 1st Reactor (mmol / min) 0.027 0.072 0.145 0.023 0.027 0.019 0.033 Polymerization temperature in the 1st Reactor (°C) 78 78 78 82 78 78 78 Butadiene added to the 2nd Reactor (g / min) 10.6 14.0 7.2 11.2 10.6 10.6 10.6 Styrene added to the 2nd Reactor (g / min) 4.5 4.4 4.2 5.3 4.5 4.5 4.5 Normal hexane added to the 2nd reactor (g / min) 41.9 49.9 33.2 44.8 41.9 41.9 41.9 Polar material added to the 2nd reactor (mmol / min) 0.415 0.370 0.253 0.153 0.415 0.298 0.596 Polymerization temperature in the 2nd Reactor (°C) 82 82 78 82 82 82 82 Styrene added to the 2nd Reactor / Butadiene added to the 2nd Reactor (% by mass) 42.3 31.3 58.4 47.3 42.5 42.3 42.3 103 / 122 Petition 870250088330, dated 09 / 29 / 2025, pp. 109 / 139 Sample no. Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 A1 A2 A3 A4 A5 A6 A7 Styrene added to the 2nd Reactor / (Butadiene added to the 2nd Reactor + Styrene added to the 2nd Reactor) (% by mass) 29.7 23.9 36.9 32.1 29.8 29.7 29.7 Polar material added to the 2nd reactor / Polar material added to the 1st reactor (% by mol) 15.3 5.1 1.8 6.7 15.3 15.7 18.1 Polymerization reaction rate in P1 90 90 90 90 90 90 90 Coupling agent A (mmol / min) 0.097 0.097 0.097 0.097 0.110 - 0.173 Coupling agent B (mmol / min) 0.010 0.010 0.010 0.010 0,007 - - Coupling agent C (mmol / min) - - - - - - - First polymeric segment (Physical property 1) Amount of styrene bonded X1 (% by mass) 0 0 0 0 0 0 0 (Physical property 2) Amount of vinyl bond Y1 (% by mol) 20 30 40 15 20 20 20 (Physical property 3) Segment ratio π (% by mass) 50 45 60 50 50 50 50 Expression (2)Y1 OOOOOOO Second segment (Physical property 1) Amount of styrene bonded X2 (% by mass) 25 20 30 20 25 25 25, 104 / 122 Petition 870250088330, dated 09 / 29 / 2025, pp. 110 / 139 Sample no. Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 A1 A2 A3 A4 A5 A6 A7 Polymeric (Physical Property 2) Amount of vinyl bond Y2 (mol %) 60 50 56 42 60 60 60 (Physical Property 3) Segment ratio r2 (mass %) 50 55 40 50 50 50 50 (Physical Property 4) Estimated glass transition temperature (°C) -23 -38 -19 -43 -23 -23 -23 Conjugated diene-based polymer (Physical Property 1) Amount of styrene bonded Xtotal (mass %) 11 11 11 10 11 11 11 (Physical Property 2) Amount of vinyl bond Ytotal (% by mol) 35 35 45 30 35 35 35 (Physical property 4) Estimated glass transition temperature (°C) -61 -61 -53 -67 -61 -61 -61 (Physical property 5) Weight-average molecular weight Mw (10⁴ g / mol) 50 50 50 50 47 51 35 (Physical property 5) Number-average molecular weight Mn (10⁴ g / mol) 27 27 27 27 27 30 19 (Physical property 5) Molecular weight distribution Mw / Mn 1.85 1.85 1.85 1.85 1.74 1.70 1.70 (Physical property 6) Mooney viscosity of the polymer 67 67 67 67 62 63 35, 105 / 122 Petition 870250088330, dated 09 / 29 / 2025, pp. 111 / 139 Sample no. (Physical property 7) Extrapolated initial glass transition temperature (Physical property 7) Glass transition temperature (Physical property 7) Extrapolated final glass transition temperature (Physical property 7) Extrapolated final glass transition temperature - Initial temperature (Physical property 8) Modification rate Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 A1 A2 A3 A4 A5 A6 A7 (°C) -76.5 -74.0 -62.0 -78.0 -76.5 -76.5 -76.5 (°C) -64.0 -58.5 -54.0 -69.0 -64.0 -64.0 -64.0 (°C) -53.0 -46.2 -46.5 -58.0 -53.0 -53.0 -53.0 (°C) 23.5 27.8 15.5 20.0 23.5 23.5 23.5 (%) 78.0 78.0 78.0 78.0 78.0 0.0 78.8 106 / 122 Petition 870250088330, dated 09 / 29 / 2025, pp. 112 / 139 Table 2 Sample no. Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Example 14 Example 15 Example 16 A8 A9 A10 A11 A12 A13 A14 A15 A16 n-Butyllithium polymerization conditions for treatment (mmol / min) 0.104 0.104 0.104 0.104 0.104 0.104 0.104 0.104 0.104 n-Butyllithium polymerization initiator (mmol / min) 0.198 0.130 0.239 0.239 0.224 0.370 0.062 0.239 0.239 Butadiene added to the 1st Reactor (g / min) 18.8 18.8 18.8 18.8 13.8 18.8 18.8 21.4 15.4 Styrene added to the 1st Reactor (g / min) 0.0 0.0 0.0 0.0 4.4 0.0 0.0 0.0 0.0 Normal hexane added to the 1st Reactor (g / min) 163.4 163.4 163.4 163.4 104.8 163.4 163.4 170.3 166.0 Polar material added to the 1st Reactor (mmol / min) 0.019 0.015 0.023 0.266 0.003 0.036 0.007 0.054 0.072 Polymerization temperature In the 1st Reactor (°C) 78 78 82 78 65 78 78 78 78 Butadiene added to the 2nd Reactor (g / min) 10.6 10.6 13.8 10.6 2.9 10.6 10.6 9.2 12.6 Styrene added to the 2nd Reactor (g / min) 4.5 4.5 2.7 4.5 0.0 4.5 4.5 3.5 5.3. Normal hexane added to the 2nd reactor (g / min) 41.9 41.9 46.6 42.0 9.5 41.9 41.9 36.8 48.2 Polar material added to the 2nd reactor (mmol / min) 0.298 0.235 0.153 0.176 0.020 0.641 0.094 0.394 0.340 Polymerization temperature in the 2nd reactor (°C) 82 82 82 82 65 82 82 82 80 Styrene added to the 2nd reactor / Butadiene added to the 2nd reactor (% by mass) 42.3 42.3 19.6 42.5 0.0 42.3 42.3 38.1 42.4 Styrene added to the 2nd Reactor / (Butadiene added to the 2nd Reactor + Styrene added to the 2nd Reactor) (% by mass) 29.7 29.7 16.4 29.8 0.0 29.7 29.7 27.6 29.8 Polar material added to the 2nd reactor / Polar material added to the 1st reactor (% by mol) 15.7 15.7 6.7 0.7 6.7 17.8 13.5 7.3 4.7 Polymerization reaction rate in P1 90 90 90 90 70 90 90 90 90 107 / 122 Petition 870250088330, dated 09 / 29 / 2025, pp. 113 / 139 Sample no. Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Example 14 Example 15 Example 16 A8 A9 A10 A11 A12 A13 A14 A15 A16 Coupling agent A (mmol / min) - - 0.097 0.097 0.087 0.185 - 0.097 0.097 Coupling agent B (mmol / min) - 0.017 0.010 0.010 0.009 - 0.008 0.010 0.010 Coupling agent C (mmol / min) 0.052 - - - - - - - - First polymer segment (Physical property 1) Amount of styrene bonded Xi (% by mass) 0 0 0 0 7 0 0 0 0 (Physical property 2) Amount of vinyl bond Yi (mol %) 20 20 15 50 12 20 20 25 30 (Physical property 3) Segment ratio ri (mass %) 50 50 50 50 70 50 50 58 45 Expression (2) Y1 OOO x OOOOO Second polymeric segment (Physical property 1) Amount of styrene bonded X2 (mass %) 25 25 10 25 40 25 25 20 25 (Physical property 2) Amount of vinyl bond Y2 (mol %) 60 60 42 50 28 60 60 55 57 (Physical property 3) Segment ratio r2 (mass %) 50 50 50 50 30 50 50 4255 (Physical property 4) Estimated glass transition temperature (°C) -23 -23 -57 -31 -24 -23 -23 -34 -25 Conjugated diene-based polymer (Physical property 1) Amount of styrene bonded Xtotal (% by mass) 11 11 5 13 17 11 11 9 13 (Physical property 2) Amount of vinyl bond Ytotal (% by mol) 35 35 31 50 13 35 35 36 43 (Physical property 4) Estimated glass transition temperature (°C) -61 -61 -72 -47 -70 -61 -61 -63 -50 108 / 122 Petition 870250088330, dated 09 / 29 / 2025, pp. 114 / 139 Sample no. Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Example 14 Example 15 Example 16 A8 A9 A10 A11 A12 A13 A14 A15 A16 (Physical Property 5) Weight-average molecular weight Average Mw (10⁴ g / mol) 83 115 50 50 50 29 138 50 50 (Physical Property 5) Number-average molecular weight Mn (10⁴ g / mol) 44 61 27 27 30 17 66 27 27 (Physical Property 5) Molecular weight distribution Mw / Mn 1.89 1.89 1.85 1.85 1.65 1.70 2.10 1.85 1.85 (Physical property 6) Mooney viscosity of the polymer 110 110 67 67 67 23 125 67 67 (Physical property 7) Extrapolated initial glass transition temperature (°C) -76.5 -76.5 -85.0 -58.0 -80.0 -76.5 -76.5 -76.1 -73.7 (Physical property 7) Glass transition temperature (°C) -64.0 -64.0 -74.0 -49.0 -69.0 -64.0 -64.0 -64.7 -57.4 (Physical property 7) Extrapolated final glass transition temperature (°C) -53.0 -53.0 -60.5 -40.0 -58.0 -53.0 -53.0 -54.5 -395 (Physical property 7) Extrapolated final glass transition temperature - Initiation temperature (°C) 23.5 23.5 23.5 18.0 22.0 23.5 23.5 21.6 34.2 (Physical property 8) Modification rate (%) 77.5 78.5 78.0 73.0 65.0 80.0 75.0 78.0 78.0 109 / 122 Petition 870250088330, dated 09 / 29 / 2025, pp. 115 / 139 Table 3 Sample no. Example Ref. 1 Example Example 1 Example Example 2 Example Example 3 Example Example 4 Example Example 5 B1 B2 B3 B4 B5 B6 n-Butyllithium polymerization conditions for treatment (mmol / min) 0.104 0.104 0.104 0.104 0.104 0.104 n-Butyllithium polymerization initiator (mmol / min) 0.239 0.239 0.193 0.343 0.198 0.130 Butadiene added to the 1st Reactor (g / min) 22.3 18.8 22.3 22.3 22.3 22.3 Styrene added to the 1st Reactor (g / min) 4.2 0.0 4.2 4.2 4.2 4.2 Normal hexane added Material added to the 1st Reactor (g / min) 178.8 163.4 109.2 109.2 109.2 109.2 Polar Material added to the 1st Reactor (mmol / min) 0.101 0.266 0.070 0.124 0.070 0.055 Polymerization temperature in the 1st Reactor (°C) 68 78 68 68 68 68 Butadiene added to the 2nd Reactor (g / min) 7.4 9.7 7.4 7.4 7.4 7.4 Styrene added to the 2nd Reactor (g / min) 0.0 5.4 0.0 0.0 0.0 0.0 Normal Hexane added to the 2nd Reactor (g / min) 26.7 41.3 26.7 26.7 26.7 26.7 Polar Material added to the 2nd Reactor (mmol / min) 0.000 0.156 0.000 0.000 0.000 0.Polymerization temperature in the 2nd reactor (°C) 73 82 73 73 73 73 Styrene added to the 2nd reactor / Butadiene added to the 2nd reactor (% by mass) 0.0 55.7 0.0 0.0 0.0 0.0 110 / 122 Petition 870250088330, dated 09 / 29 / 2025, pp. 116 / 139 Sample No. Ex. Ref. 1 Example Ex. 1 Example Ex. 2 Example Ex. 3 Example Ex. 4 Example Ex. 5 B1 B2 B3 B4 B5 B6 Styrene added to the 2nd Reactor / (Butadiene added to the 2nd Reactor + Styrene added to the 2nd Reactor) (% by mass) 0.0 35.8 0.0 0.0 0.0 0.0 Polar material added to the 2nd reactor / Polar material added to the 1st reactor (% by mol) 0.0 0.6 0.0 0.0 0.0 0.0 Polymerization reaction rate in P1 90 90 90 90 90 90 Coupling agent A (mmol / min) 0.097 0.097 - 0.173 - - Coupling agent B (mmol / min) 0.010 0.010 - - - 0.017 Coupling agent C (mmol / min) - - - - 0.052 - First polymeric segment (Physical property 1) Amount of styrene bonded X1 (% by mass) - 0 - - - - (Physical property 2) Amount of vinyl bond Y1 (% by mol) - 50 - - - - (Physical property 3) Segment ratio π (% by mass) - 50 - - - - Expression (2)Y1 (% by mol) - x - - - - 111 / 122 Petition 870250088330, dated 09 / 29 / 2025, pp. 117 / 139 Sample No. Ex. Ref. 1 Example Ex. 1 Example Ex. 2 Example Ex. 3 Example Ex. 4 Example Ex.5 B1 B2 B3 B4 B5 B6 Second polymeric segment (Physical property 1) Amount of styrene bonded X2 (% by mass) - 30 - - - - (Physical property 2) Amount of vinyl bond Y2 (% by mol) - 60 - - - - (Physical property 3) Segment ratio r2 (% by mass) - 50 - - - - (Physical property 4) Estimated glass transition temperature (°C) - -16 - - - - Conjugated diene-based polymer (Physical property 1) Amount of styrene bonded Xtotal (% by mass) 10 15 10 10 10 10 (Physical property 2) Amount of vinyl bond Ytotal (% by mol) 37 55 37 37 37 37 (Physical property 4) Estimated glass transition temperature (°C) -61 -40 -61 -61 -61 -61 (Physical Property 5) Weight-average molecular weight Average Mw (104 g / mol) 50 50 51 35 83 115 (Physical Property 5) Number-average molecular weight Mn (104 g / mol) 27 27 30 19 44 61 (Physical Property 5) Molecular weight distribution Mw / Mn 1.85 1.85 1.70 1.89 1.89 1.89. 112 / 122 Petition 870250088330, dated 09 / 29 / 2025, pp. 118 / 139 Sample no. (Physical property 6) Mooney viscosity of the polymer (Physical property 7) Extrapolated initial glass transition temperature (Physical property 7) Glass transition temperature (Physical property 7) Extrapolated final glass transition temperature (Physical property 7) Extrapolated final glass transition temperature - Initial temperature (Physical property 8) Modification ratio Ex. Ref. 1 Example Ex. 1 Example Ex. 2 Example Ex. 3 Example Ex. 4 Example Ex. 5 B1 B2 B3 B4 B5 B6 67 67 63 35 110 110 (°C) -65.0 -52.0 -65.0 -65.0 -65.0 -65.0 (°C) -61.4 -42.0 -61.4 -61.4 -61.4 -61.4 (°C) -57.9 -32.0 -57.9 -57.9 -57.9 -57.9 (°C) 7.1 20.0 7.1 7.1 7.1 7.1 (%) 85.2 78.0 0.0 78.8 77.5 74.5 113 / 122 Petition 870250088330, dated 09 / 29 / 2025, pp. 119 / 139 114 / 122 Examples 17 to 32, Reference Example 2 and Comparative Examples 6 to 10

[00392] The diene-based conjugated polymers A1 to A16 and B1 to B6 shown in Tables 1 to 3 were used, respectively, as raw material rubbers to obtain rubber compositions containing the respective raw material rubbers according to the following composition:

[00393] Conjugated diene-based polymer (any from A1 to A16 and B1 to B6): 100 parts by mass (excluding oil).

[00394] Silica (trade name Ultrasil 7000GR, manufactured by Evonik Degussa, specific surface area for nitrogen adsorption: 170 m2 / g): 85.0 parts by mass.

[00395] Carbon black (trade name Seast 7HM (N234), manufactured by Tokai Carbon Co., Ltd.): 2.0 parts by mass.

[00396] Silane coupling agent: (trade name Si69, manufactured by Evonik Degussa, bis(triethoxysilylpropyl)tetrasulfide): 6.8 parts by mass.

[00397] SRAE oil (trade name Process NC140, manufactured by JX Nippon Oil & Energy Corporation): 40 parts by mass.

[00398] Zinc oxide: 2.4 parts by mass.

[00399] Stearic acid: 1.25 parts by mass.

[00400] Anti-aging agent (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine): 3.5 parts by mass.

[00401] Sulfur: 1.0 part by mass.

[00402] Vulcanization accelerator 1: tetrabenzylthiuram disulfide: 0.5 parts by mass.

[00403] Vulcanization accelerator 2: N-(tert-butyl)-2-benzothiazolsulfenamide: 2.5 parts by mass.

[00404] Total: 246.95 parts by mass. Petition 870250088330, dated 09 / 29 / 2025, pages 120 / 139 115 / 122

[00405] The materials described above were crushed using the following method to obtain a rubber composition.

[00406] A closed mixer (with an internal volume of 0.3 L) equipped with a temperature controller was used to mix, as the first mixing stage, the rubber raw material (any from A1 to A16 and B1 to B6), the fillers (silica and carbon black), the silane coupling agent, the process oil, zinc oxide, and stearic acid under conditions of a filling rate of 65% and a rotor rotation speed of 30 to 50 rpm. Here, the temperature of the closed mixer was controlled to obtain each rubber compound at a discharge temperature of 145 to 150°C.

[00407] Next, after cooling the compound obtained as described above to room temperature, as a second kneading step, the anti-aging agent was added and the resulting material was kneaded again to improve the dispersion capacity of the silica. Also in this case, the discharge temperature of the compound was adjusted to 120°C by the temperature control of the kneader.

[00408] After cooling, as the third stage of kneading, with sulfur and vulcanization accelerators 1 and 2 added, the resulting material was kneaded with an open roller set to 70°C.

[00409] Next, the resulting material was molded and vulcanized at 160°C for 20 minutes using a vulcanizing press.

[00410] The rubber compositions were evaluated before vulcanization and the rubber compositions after vulcanization.

[00411] Specifically, the assessments were carried out as described below.

[00412] The results are shown in Tables 4 to 6. Petition 870250088330, dated 09 / 29 / 2025, pp. 121 / 139 116 / 122 Assessments 1 to 3: Viscoelasticity parameter

[00413] An ARES viscoelasticity testing machine manufactured by Rheometric Scientific, Inc. was used to measure a viscoelasticity parameter in torsional mode.

[00414] Each measurement value was shown as an index obtained by assuming that the result obtained in the rubber composition of Reference Example 2 was 100. [Rating 1] Low hysteresis loss property

[00415] A tanδ measured at 50°C at a frequency of 10 Hz and 3% deformation was used as an index of the low hysteresis loss property.

[00416] A higher index indicates a better low hysteresis loss property, and it was determined that the composition had a sufficient low hysteresis loss property when the index value was greater than 85. [Evaluation 2] Wet grip performance

[00417] A tanδ measured at 0°C at a frequency of 10 Hz and a deformation of 1% was used as an index of wet grip performance.

[00418] A higher index indicates better wet grip properties.

[00419] It was determined that the composition had sufficient wet grip properties when the index value was 130 or higher. [Evaluation 3] Low temperature performance

[00420] A storage module G' measured at -20°C at a frequency of 10 Hz and 1% deformation was used as an index of low-temperature performance.

[00421] A higher index indicates better properties at low temperatures. Petition 870250088330, dated 09 / 29 / 2025, pages 122 / 139 117 / 122

[00422] It was determined that the composition had sufficient low-temperature properties when the index value was 65 or higher. [Rating 4] Abrasion resistance

[00423] An Acron abrasion tester (manufactured by Yasuda Seiki Seisakusho, Ltd.) was used to measure an amount of abrasion at 1,000 rotations at a load of 44.4 N according to JIS K6264-2, and each measured value was shown as an index obtained assuming that a result from Reference Example 2 was 100.

[00424] A higher index indicates better abrasion resistance.

[00425] The composition was determined to have sufficient abrasion resistance when the index was 70 or higher. [Assessment 5] Processability

[00426] With respect to each of the diene-based conjugated polymers before vulcanization produced by the methods described in Examples and Comparative Examples, an agglomerate (shape) obtained in the formation of the polymer into a sheet shape with a roll immediately after being discharged from a pressurization mixer (immediately after being discharged after completing the kneading with the pressurization mixer in the first stage of kneading) was visually observed to perform the evaluation based on the following criteria by the examiners, each on a scale of 1 to 5. An agglomeration property is an index of the processability of a vulcanizate.

[00427] A higher index indicates better processability.

[00428] It was determined that the composition had sufficient processability when the index was 4 or more. Evaluation criteria 1: A portion of the sheet's end was smooth by 50% or less, and the processability was very unsatisfactory. Petition 870250088330, dated 09 / 29 / 2025, pp. 123 / 139 118 / 122 2: A portion of the sheet's end was smooth in more than 50% and 60% or less, and the processability was unsatisfactory. 3: One end portion of the sheet was smooth in more than 60% and 80% or less, and the processability was good. 4: One end portion of the sheet was smooth in more than 80% and 90% or less, and the processability was excellent. 5: One end portion of the sheet was smooth by more than 90%, and the processability was excellent. [Rating 6] Wet grip performance and low temperature properties

[00429] The sum of the indices calculated in Evaluations 2 and 3 was used as an index of wet grip performance and low temperature properties.

[00430] A higher index indicates that wet grip performance and low temperature properties are good. Table 4 Example 17 Example 18 Example 19 Example 20 Example 21 Example 22 Example 23 Conjugated diene-based polymer A1 A2 A3 A4 A5 A6 A7 (Evaluation 1) Low hysteresis loss property 94 95 93 94 94 62 94 (Evaluation 2) Wet grip performance 140 140 160 135 140 140 140 (Evaluation 3) Low temperature performance 90 92 88 91 90 62 90 (Evaluation 4) Abrasion resistance 100 100 86 110 100 85 80 Petition 870250088330, dated 09 / 29 / 2025, pp. 124 / 139 119 / 122 Example 17 Example 18 Example 19 Example 20 Example 21 Example 22 Example 23 (Evaluation 5) Processability 4 4 4 4 4 4 5 (Evaluation 6) Sum of (Evaluation 2) and (Evaluation 3) 230 232 248 226 230 202 230 Table 5 Example 24 Example 25 Example 26 Example 27 Example 28 Example 29 Example 30 Example 31 Example 32 Conjugated diene-based polymer A8 A9 A10 A11 A12 A13 A14 A15 A16 (Assessment 1) Low hysteresis loss property 89 86 94 87 86 91 83 91 88 (Assessment 2) Wet grip performance 140 140 130 180 130 140 140 137 180 (Assessment 3) Low temperature performance 84 80 96 68 89 100 62 93 79 (Assessment 4) Abrasion resistance 118 121 120 70 90 67 135 104 83 (Evaluation 5) Processability 4 3 4 4 3 5 2 4 4 (Evaluation 6) Sum of (Evaluation 2) and (Evaluation 3) 224 220 226 248 219 240 202 230 259 Petition 870250088330, dated 09 / 29 / 2025, pp. 125 / 139 120 / 122 Table 6 Ex. Ref. 2 Example Comp. 6 Example Comp. 7 Example Comp. 8 Example Comp. 9 Example Comp. 10 Conjugated diene-based polymer B1 B2 B3 B4 B5 B6 (Assessment 1) Low hysteresis loss property 100 85 64 101 99 97 (Assessment 2) Wet grip performance 100 220 100 100 100 100 (Assessment 3) Low temperature performance 100 64 78 104 87 82 (Assessment 4) Abrasion resistance 100 60 85 80 118 121 (Assessment 5) Processability 4 4 5 4 4 3 (Assessment 6) Sum of (Assessment 2) and (Assessment 3) 200 284 178 204 187 182

[00431] As shown in Tables 4 to 6, it was found that the rubber compositions of the conjugated diene-based polymers of Examples 17 to 32 using the conjugated diene-based polymers A1 to A16 that satisfy the estimated Tg are superior in the low-temperature property obtained in the form of vulcanizates compared to the rubber composition of Comparative Example 6 that uses the conjugated diene-based polymer B2.

[00432] As shown in Tables 4 to 6, it was verified that the rubber compositions of the conjugated diene-based polymers of Examples 17 to 21, 23, 27 to 29, 31 and 32 using the conjugated diene-based polymers A1 to A5, A7, A11 to A13, A15 and A16 satisfy the difference between the final and initial temperatures extrapolated from the glass transition temperature of 15°C or more and 35°C or less. Petition 870250088330, dated 09 / 29 / 2025, pp. 126 / 139 121 / 122 are superior in terms of the balance between wet grip performance and low-temperature properties obtained in vulcanized form compared to the rubber compound of Reference Example 2 which uses the conjugated diene-based polymer B1.

[00433] As shown in Tables 4 to 6, the rubber composition of Example 22 using the conjugated diene-based polymer A6 was found to be superior in the balance between wet grip performance and low-temperature properties obtained in the form of a vulcanizate compared to the rubber composition of Comparative Example 7 using the conjugated diene-based polymer B3.

[00434] It was found, in the comparison between Example 23 and Comparative Example 8, between Example 24 and Comparative Example 9, and between Example 25 and Comparative Example 10, that the balance between wet grip performance and low temperature property obtained in the form of a vulcanized material is excellent in the Examples.

[00435] As shown in Tables 4 to 6, it was found that the rubber compositions of Examples 17 to 24, 26, 27, 29, 31 and 32 using the conjugated diene-based polymers A1 to A8, A10, A11, A13, A15 and A16 that satisfy the molecular weight distribution of 1.7 or more and 2.5 or less are excellent in terms of processability obtained in the form of vulcanizates.

[00436] As shown in Tables 4 to 6, the rubber compositions of Examples 17 to 21 and 23 to 32 using the conjugated diene-based polymers A1 to A5 and A7 to A16 were found to be superior in the low hysteresis loss property obtained in the form of vulcanizates compared to the rubber composition of Comparative Example 7 using the conjugated diene-based polymer B3. Petition 870250088330, dated 09 / 29 / 2025, pp. 127 / 139 122 / 122

[00437] This application is based on the Japanese Patent Application filed with the Japanese Patent Office on April 27, 2023 (Japanese Patent Application No. 2023-072838), the full content of which is incorporated herein by reference. Industrial Applicability

[00438] A conjugated diene-based polymer of the present invention is industrially applicable as materials in various fields, such as tire tread, vehicle interior and exterior, anti-vibration rubber, belts, shoes, foam bodywork and various industrial products. Petition 870250088330, dated 09 / 29 / 2025, pages 128 / 139

Claims

1 / 3 CLAIMS 1. A conjugated diene-based polymer, characterized in that an estimated glass transition temperature (estimated Tg) derived from a microstructure of the conjugated diene-based polymer is -72°C or higher and -45°C or lower, the conjugated diene-based polymer has only one glass transition temperature (Tg) measured by differential scanning calorimetry (DSC), and a difference between an extrapolated initial temperature and an extrapolated final temperature of the glass transition temperature (Tg) is 15°C or higher and 35°C or lower.

2. Conjugated diene-based polymer according to claim 1, characterized in that it comprises a first polymeric segment without an aromatic vinyl monomer unit and a second polymeric segment with an aromatic vinyl monomer unit, wherein a vinyl linkage amount Y1 (mol %) in the conjugated diene linked in the first polymeric segment satisfies the following expression (2): 10 < Yi < 45 ... (2) an estimated glass transition temperature (estimated Tg) derived from a microstructure of the second polymeric segment is greater than -45°C and -5°C or less.

3. A conjugated diene-based polymer according to claim 1, characterized in that the molecular weight distribution corresponding to a ratio Mw / Mn between a weight-average molecular weight Mw and a number-average molecular weight Mn is 1.7 or more and 2.5 or less.

4. Conjugated diene-based polymer, according to Petition 870250088330, dated 09 / 29 / 2025, pp. 129 / 139 2 / 3 claim 2, characterized in that a segment ratio of the first polymeric segment is 20% by mass or more and 80% by mass or less.

5. Conjugated diene-based polymer according to claim 1, characterized in that it has a weight-average molecular weight of 300,000 or more and 1,350,000 or less.

6. Conjugated diene-based polymer according to claim 1, characterized in that it comprises a nitrogen atom.

7. Conjugated diene-based polymer according to claim 6, characterized in that the modification ratio of the conjugated diene-based polymer is 70% or more.

8. Method for producing the conjugated diene-based polymer, as defined in claim 2, using two or more continuous reactors, the method characterized in that it comprises: a first polymerization step (P1) of continuous formation of the first polymeric segment of the conjugated diene-based polymer with a conjugated diene compound, a polymerization initiator and a polar material added to the continuous reactors; and a second polymerization step (P2) of formation of the second polymeric segment at one end of the first polymeric segment with an aromatic vinyl compound and a polar material added to the continuous reactors.

9. Method for producing the conjugated diene-based polymer according to claim 8, characterized in that it further comprises, after the second polymerization step (P2): a coupling step (P3) of reacting a coupling agent with the conjugated diene-based polymer.

10. Method for producing the conjugated diene-based polymer according to claim 8, characterized in that Petition 870250088330, dated 09 / 29 / 2025, pp. 130 / 139 3 / 3 a mass ratio between the conjugated diene compound added in the first polymerization step (P1) and a total amount of the conjugated diene compound and the added aromatic vinyl compound is 20% by mass or more and 80% by mass or less.

11. Method for producing the conjugated diene-based polymer according to claim 8, characterized in that the polymerization reaction rate in the first polymerization step (P1) is 75% or more and 95% or less.

12. Method for producing the conjugated diene-based polymer according to claim 8, characterized in that the mass ratio of an amount of the added aromatic vinyl compound to an amount of the conjugated diene compound added in the second polymerization step (P2) is 0.15 or more and 0.70 or less.

13. Method for producing the conjugated diene-based polymer according to claim 8, characterized in that the polar material is added in the second polymerization step (P2) in a greater quantity than the quantity of polar material added in the first polymerization step (P1).

14. Method for producing the conjugated diene-based polymer according to claim 9, characterized in that the coupling agent is an aminoalkoxysilane compound. Petition 870250088330, dated 09 / 29 / 2025, pp. 131 / 139