Conjugated diene polymer, molded article, method for producing conjugated diene polymer, rubber composition, and tire

Abstract

The present invention provides a display device that satisfies the following lt; condition (i) gt; -lt; condition (iii) gt; and a conjugated diene polymer. Lt; condition (i) gt; the Mooney viscosity measured at 100 DEG C is from 80 to 170 (inclusive). Lt; condition (ii) gt; the Mooney stress relaxation (MSR) measured at 100 DEG C is from 0.30 to 0.80 (inclusive). Lt; condition (iii) gt; the polymer has a downward convex extreme value in a branching degree distribution curve indicating the relationship between the absolute molecular weight and the branching degree (Bn) according to a GPC-light scattering measurement method with a viscosity detector.

Description

Technical Field

[0001] The present invention relates to a conjugated diene polymer, a molded product, a method for producing a conjugated diene polymer, a rubber composition and a tire. Background Art

[0002] In recent years, the demand for lower fuel consumption in automobiles has increased, and there is a demand for improvements in rubber materials used in automobile tires, especially tire treads that come into contact with the road. Due to the increasing fuel consumption regulations for automobiles, there is an increasing demand for resin-based automobile parts and thinner tires for the purpose of reducing the weight of automobiles.

[0003] As a constituent component of the rubber material, a conjugated diene polymer is used. In order to improve the breaking strength and abrasion resistance of the conjugated diene polymer, the molecular weight of the conjugated diene polymer is being increased.

[0004] However, high molecular weight conjugated diene polymers have the following problems: polymer particles are easily detached from the surface of the conjugated diene polymer agglomerate, and the surrounding area of ​​the molding machine or the surrounding area of ​​the conveyor that transfers the agglomerates after molding is contaminated by the polymer particles. Therefore, there is room for improvement in the working environment.

[0005] As a method for suppressing the fall-off of such a high molecular weight conjugated diene polymer from the surface of the agglomerate, there is mentioned a method of adding process oil.

[0006] For example, Patent Document 1 discloses a method of adding a process oil to a solution of a conjugated diene polymer to prepare an oil-extended conjugated diene polymer, thereby suppressing the falling of polymer particles from the surface of a compact.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Publication No. 2019-131810 Summary of the invention

[0010] Problems to be solved by the invention

[0011] Conventionally, conjugated diene polymers are usually oil-extended conjugated diene polymers to which process oil is added in order to improve the moldability of briquetting and the processability after kneading. On the other hand, in recent years, it has been desired to reduce the amount of process oil added to the conjugated diene polymer as much as possible in order to improve the degree of freedom in compounding when preparing the rubber composition.

[0012] However, in the case of the agglomerate of the conjugated diene polymer disclosed in Patent Document 1, there is a problem that sufficient moldability may not be obtained if the amount of process oil added is reduced.

[0013] For example, when the molecular weight of the conjugated diene polymer is increased to improve wear resistance or the glass transition temperature of the conjugated diene polymer is set low to improve low hysteresis loss properties, there is a problem that polymer particles are easily detached from the surface of the compact if the amount of process oil added in the formulation is small or no process oil is included.

[0014] Therefore, an object of the present invention is to provide a conjugated diene polymer having excellent briquetting properties even in the form of a non-oil-extended product to which no process oil is added.

[0015] Means for solving problems

[0016] The present inventors have conducted intensive studies to solve the above-mentioned problems and have found that a conjugated diene polymer having a predetermined Mooney viscosity and Mooney stress relaxation rate (MSR) and having a specific shape in a branching distribution curve measured by a GPC-light scattering method with a viscosity detector can solve the above-mentioned problems, thereby completing the present invention.

[0017] That is, the present invention is as follows. [1]

[0019] A conjugated diene polymer that satisfies the following <condition (i)> to <condition (iii)>.

[0020] <Condition (i)>

[0021] The Mooney viscosity measured at 100°C is 80 or more and 170 or less.

[0022] <Condition (ii)>

[0023] The Mooney stress relaxation ratio (MSR) measured at 100°C is 0.30 or more and 0.80 or less.

[0024] <Condition (iii)>

[0025] According to the GPC-light scattering method with a viscosity detector, the branching degree distribution curve showing the relationship between the absolute molecular weight and the branching degree (Bn) has an extreme value that is convex downward. [2]

[0027] The conjugated diene polymer as described in the above [1], wherein

[0028] The glass transition temperature is -90℃~-40℃,

[0029] When the height of the peak top in the absolute molecular weight distribution curve determined by GPC-light scattering method with a viscosity detector (wherein, when there are multiple peak tops in the absolute molecular weight distribution curve, the height of the peak top with the largest absolute molecular weight) Hi is used as a reference, the degree of branching of the conjugated diene polymer at the highest absolute molecular weight Mw(high) of at least two absolute molecular weights when the height in the absolute molecular weight distribution curve is 1 / 2 of Hi (1 / 2Hi) is set as Bn(high), the degree of branching of the conjugated diene polymer at the lowest absolute molecular weight Mw(low) is set as Bn(low), and the degree of branching of the conjugated diene polymer at the peak top of the absolute molecular weight distribution curve is set as Bn(top), the following conditions (I) to (III) are satisfied.

[0030] <Condition (I)>

[0031] (Bn(high))-(Bn(top))≧1.0

[0032] <Condition (II)>

[0033] (Bn(low))-(Bn(top))≧0.5

[0034] <Condition (III)>

[0035] (Bn(high)) / (Bn(low))=1.1~2.0 [3]

[0037] The conjugated diene polymer according to the above [2], wherein the extreme value of the branching degree distribution curve is located at an absolute molecular weight between the Mw(low) and the Mw(high). [4]

[0039] The conjugated diene polymer according to any one of [1] to [3] above, wherein the molecular weight distribution (PDI; MWD) is 1.4 to 3.5. [5]

[0041] The conjugated diene polymer according to any one of [1] to [4], wherein the degree of branching at the extreme value in the branching degree distribution curve is 3.0 or more and 8.0 or less. [6]

[0043] The conjugated diene polymer according to any one of [1] to [5] above, wherein the modification rate is 60% by mass or more. [7]

[0045] The conjugated diene polymer according to any one of [1] to [6] above, comprising:

[0046] A fork-shaped portion [A] having a plurality of conjugated diene polymer chains bonded to one end of a main chain branch structure portion and a single chain of another conjugated diene polymer bonded to the other end of the main chain branch structure portion; and

[0047] A star-shaped polymer structure [B] having three or more branches to which one or more fork-shaped parts [A] are bonded

[0048] Conjugated diene polymers. [8]

[0050] The conjugated diene polymer as described in any one of [1] to [7] above, comprising:

[0051] A conjugated diene polymer having a fork-shaped portion [A] in which a plurality of conjugated diene polymer chains are bonded to one end of a main chain branch structure portion and a single chain of another conjugated diene polymer is bonded to the other end of the main chain branch structure portion; and

[0052] A conjugated diene polymer having a three-branched or more star-shaped polymer structure [B] to which one or more fork-shaped portions [A] are bonded. [9]

[0054] A shaped body comprising:

[0055] 100 parts by mass of the conjugated diene polymer described in any one of [1] to [8] above; and

[0056] Less than 1 part by mass of softener component.

[10]

[0058] A method for producing a conjugated diene polymer, which is the method for producing a conjugated diene polymer according to any one of [1] to [8] above, wherein the method comprises the following steps:

[0059] A step of polymerizing at least a conjugated diene compound using an organic lithium compound as a polymerization initiator;

[0060] A step of adding a branching agent; and

[0061] A step of adding two or more coupling modifiers having different coupling numbers.

[11]

[0063] The method for producing a conjugated diene polymer as described in

[10] above, wherein the two or more coupling modifiers include:

[0064] A coupling modifier having 2 or less alkoxysilyl groups, and

[0065] A coupling modifier comprising greater than 2 alkoxysilyl groups.

[12]

[0067] A rubber composition comprising:

[0068] 100 parts by mass of a rubber component; and

[0069] 5.0 parts by mass or more and 150 parts by mass or less of a filler,

[0070] The rubber component contains 10 parts by mass or more of the conjugated diene polymer described in any one of [1] to [8] above, based on 100 parts by mass of the total amount of the rubber component.

[13]

[0072] A tire comprising the rubber composition described in

[12] above.

[0073] Effects of the Invention

[0074] According to the present invention, it is possible to provide a conjugated diene polymer having excellent briquetting properties even in the case of a non-oil-extended product to which no process oil is added. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] Figure 1 This is a schematic diagram showing the relationship between the absolute molecular weight curve obtained by the GPC-light scattering measurement method with a viscosity detector and the branching degree distribution. DETAILED DESCRIPTION

[0076] A specific embodiment of the present invention (hereinafter referred to as “this embodiment”) will be described in detail below.

[0077] It should be noted that the following embodiments are examples for explaining the present invention, and the present invention is not limited to the following embodiments. The present invention can be implemented by appropriately modifying the present invention within the scope of the gist thereof.

[0078] [Conjugated diene polymer]

[0079] The conjugated diene polymer of the present embodiment satisfies the following <condition (i)> to <condition (iii)>.

[0080] <Condition (i)>

[0081] The Mooney viscosity measured at 100°C is 80 or more and 170 or less.

[0082] <Condition (ii)>

[0083] The Mooney stress relaxation ratio (MSR) measured at 100°C is 0.30 or more and 0.8 or less.

[0084] <Condition (iii)>

[0085] According to the GPC-light scattering method with a viscosity detector, the branching degree distribution curve showing the relationship between the absolute molecular weight and the branching degree (Bn) has an extreme value that is convex downward.

[0086] The conjugated diene polymer of the present embodiment has excellent briquetting properties even in the case of a non-oil-extended product to which no process oil is added.

[0087] The conjugated diene polymer of the present embodiment may be any of a homopolymer of a single conjugated diene compound, a copolymer which is a polymer of different types of conjugated diene compounds, and a copolymer of a conjugated diene compound and a vinyl aromatic compound.

[0088] As conjugated diene compounds, for example, 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 can be cited but are not limited thereto. Among these, 1,3-butadiene and isoprene are preferred from the aspect of effectively and surely exerting the effect of the present embodiment. These conjugated diene compounds can be used alone or in combination of two or more.

[0089] In addition, examples of vinyl aromatic compounds include, but are not limited to, styrene, p-methylstyrene, α-methylstyrene, vinylethylbenzene, vinylxylene, vinylnaphthalene, and diphenylethylene. Among these, styrene is preferred from the perspective of effectively and reliably exerting the effects of the present embodiment. These vinyl aromatic compounds may be used alone or in combination of two or more.

[0090] (Condition (i): Mooney viscosity of conjugated diene polymer)

[0091] Mooney viscosity is an index showing the comprehensive characteristics of a conjugated diene polymer, including information on the molecular weight, molecular weight distribution, degree of branching, and content of a softener of the conjugated diene polymer. In addition, the Mooney viscosity measurement method is specified by ISO 289, and the error of the measured value due to mechanical error is also very small, which is extremely effective in controlling the performance of the conjugated diene polymer.

[0092] The Mooney viscosity of the conjugated diene polymer of the present embodiment measured at 100°C (hereinafter also referred to as "Mooney viscosity" or "ML") is 80 or more, and is preferably 90 or more, and more preferably 100 or more, from the perspective of handling stability, breaking strength, and wear resistance when the cross-linked rubber composition containing the conjugated diene polymer of the present embodiment is used in a tire.

[0093] On the other hand, the upper limit is 170 or less, and is preferably 160 or less, more preferably 150 or less, and further preferably 145 or less, from the perspective of moldability and productivity of various shapes of molded products such as sheets and blocks or rubber compositions containing the conjugated diene polymer of the present embodiment, and processability of rubber compositions mixed with fillers and the like.

[0094] Usually, the higher the Mooney viscosity of a conjugated diene polymer is, the more the handling stability, breaking strength and wear resistance of the conjugated diene polymer and its rubber composition when used for tires are improved. On the other hand, the moldability of the sheet-like or block-shaped molded body and the rubber composition containing the conjugated diene polymer is more deteriorated. Usually, when the Mooney viscosity of the conjugated diene polymer is more than 80, in order to be molded into a briquette, it is necessary to mix the operating oil, but in the conjugated diene polymer of the present embodiment, as described below, there is a significant feature in the following aspects: in the branching distribution curve representing the relationship between the absolute molecular weight and the degree of branching (Bn), by being limited to a shape with a downwardly convex extreme value, even if it is usually difficult to carry out briquetting molding of the Mooney viscosity of more than 80 conjugated diene polymers without adding operating oil, briquetting molding can be carried out. In addition, by being limited to a Mooney viscosity of less than 170, the conjugated diene polymer can be suppressed from falling off the briquette, showing good briquetting moldability.

[0095] Regarding the Mooney viscosity of the conjugated diene polymer, a sample of a plate made by pressing the conjugated diene polymer is placed in a measuring device, and the sample is first preheated at 100° C. for 1 minute, and then the rotor is rotated at 2 rpm. The torque is measured after 4 minutes, and the measured value is taken as the Mooney viscosity (ML (1+4) ). More specifically, it can be measured by the method described in the examples described later.

[0096] The Mooney viscosity of the conjugated diene polymer of the present embodiment can be controlled within the above numerical range by adjusting the type, use timing and amount of the branching agent and coupling modifier, the molecular weight, molecular weight distribution and branching degree of the conjugated diene polymer.

[0097] (Condition (ii): Mooney stress relaxation rate of conjugated diene polymer)

[0098] The Mooney stress relaxation rate (hereinafter also referred to as "Mooney stress relaxation rate" or "MSR") of the conjugated diene polymer of the present embodiment measured at 100°C is 0.8 or less, preferably 0.75 or less, and more preferably 0.72 or less from the viewpoint of processability of a rubber composition obtained by blending a filler and the like with the conjugated diene polymer. On the other hand, the Mooney stress relaxation rate is 0.30 or more, preferably 0.35 or more, more preferably 0.40 or more, and even more preferably 0.45 or more from the viewpoint of handling stability and breaking strength when the conjugated diene polymer of the present embodiment is used as a material for a tire.

[0099] The Mooney stress relaxation rate is also affected by the molecular weight, molecular weight distribution, degree of branching, and content of the softener of the conjugated diene polymer, similarly to the Mooney viscosity, and is an index representing the overall characteristics of the conjugated diene polymer.

[0100] MSR can be measured using a Mooney viscometer as follows.

[0101] The Mooney stress relaxation rate was calculated by preheating the sample at 100°C for 1 minute, rotating the rotor at 2 rpm, and calculating the Mooney viscosity (ML) based on the torque after 4 minutes. (1+4) ) is measured, and then the rotation of the rotor is stopped immediately. The torque is recorded in Mooney units every 0.1 seconds from 1.6 seconds to 5 seconds after stopping. The torque and time (seconds) are plotted logarithmically, and the slope of the straight line at this time is calculated, and its absolute value is taken as the Mooney stress relaxation rate (MSR).

[0102] More specifically, it can be measured by the method described in the Examples below.

[0103] The Mooney stress relaxation rate of the conjugated diene polymer of this embodiment can be controlled within the above numerical range by adjusting the type, use timing and amount of the branching agent and coupling modifier, the molecular weight, molecular weight distribution and branching degree of the conjugated diene polymer.

[0104] (Condition (iii): Shape of branching degree distribution curve)

[0105] In the conjugated diene polymer of the present embodiment, even in the case of a non-extended product to which a process oil is not added, the polymer exhibits excellent processability and has excellent breaking strength and wear resistance. In a branching degree distribution curve obtained by plotting the degree of branching (Bn) obtained by GPC-light scattering measurement with a viscosity detector (hereinafter also referred to as "degree of branching (Bn)", "degree of branching" or "Bn") against the absolute molecular weight obtained by GPC-light scattering measurement with a viscosity detector (hereinafter also referred to as "absolute molecular weight"), that is, a branching degree distribution curve indicating the relationship between the absolute molecular weight and the degree of branching (Bn), the polymer is limited to a shape having an extreme value that is convex downward.

[0106] The branching distribution curve is an index showing the degree of branching (Bn) of each molecular weight component of the conjugated diene polymer.

[0107] Generally, the degree of branching (Bn) is an index showing the branch structure of a polymer. For example, in the case of a common four-branched star polymer (a polymer having four polymer chains connected in the center (without further side chains)), the degree of branching (Bn) is evaluated as 2 when the arms (side chains) of two polymer chains are bonded to the longest polymer main chain.

[0108] In the case of a typical 8-branched star polymer (a polymer having 8 polymer chains connected in the center (without further side chains)), the branching degree (Bn) is evaluated as 6 when the arms (side chains) of 6 polymer chains are bonded to the longest polymer main chain.

[0109] Here, "branch" refers to a structure formed by bonding other polymer chains to one polymer chain. In addition, "branching degree (Bn)" refers to the number of polymer chains directly or indirectly bonded to each other relative to the longest polymer main chain. That is, not only the side chain bonded to the longest polymer chain, but also the number of branches of the side chain when the side chain is further branched is taken into account. Therefore, when one polymer chain is bonded to the longest polymer chain in the form of a side chain and other polymer chains are further bonded to the side chain, its branching degree is 2.

[0110] In this specification, the degree of branching (Bn) is calculated using the contraction factor (g') according to the formula g'=6Bn / {(Bn+1)(Bn+2)}. Here, the contraction factor (g') is the following value.

[0111] Generally, the molecular size of a polymer having branches tends to be smaller when compared to a linear polymer having the same absolute molecular weight. Here, "molecular size" refers to the volume substantially occupied by the molecule. The contraction factor (g') relatively represents the molecular size of the polymer as a subject, and is an indicator of the ratio of the molecular size of the polymer as a subject to the molecular size of a linear polymer having the same absolute molecular weight as the polymer as a subject. That is, if the degree of branching of a polymer is large, its size is relatively reduced, and therefore there is a tendency for the contraction factor (g') to decrease.

[0112] Here, it is known that there is a correlation between the molecular size of a polymer and the intrinsic viscosity ratio, so in this embodiment, the shrinkage factor (g') is defined as the intrinsic viscosity ratio. That is, the shrinkage factor (g') is defined as the ratio ([η] / [η0]) of the intrinsic viscosity [η] of the target polymer to the intrinsic viscosity [η0] of a linear polymer having the same absolute molecular weight as the target polymer.

[0113] It is known that the intrinsic viscosity [η0] of a linear polymer follows the rule [η0] = 10 -3.498 M 0.711 In the formula, M is the absolute molecular weight. Therefore, by measuring the absolute molecular weight and intrinsic viscosity of the polymer as a target using the GPC-light scattering method with a viscosity detector, the shrinkage factor (g') and the degree of branching (Bn) can be calculated. The calculated degree of branching (Bn) accurately shows the number of polymer chains that are directly or indirectly bonded to each other relative to the longest polymer main chain.

[0114] Here, "absolute molecular weight" refers to the molecular weight measured by light scattering. As mentioned above, usually, in the case of a linear polymer with the same absolute molecular weight, the molecular size of the polymer with branches tends to decrease. Therefore, in the GPC determination method (a method for determining the molecular weight by screening the molecular size of the polymer and comparing it with a standard polystyrene sample), the molecular weight of the polymer with branched structure tends to be evaluated too little. On the other hand, in the light scattering method, the molecular weight is measured by directly observing the molecule. Therefore, the light scattering method is not affected by the influence of the polymer structure and the influence of the interaction with the column filler, and the molecular weight can be accurately measured. It should be noted that the absolute molecular weight can be measured by the method described in the embodiment described later.

[0115] In addition, "intrinsic viscosity" preferably means the viscosity [η] calculated by the following formula (I).

[0116] In the formula (I), η1 represents the viscosity when the target polymer is dissolved in a solvent at a concentration c, and η2 represents the viscosity of the solvent.

[0117] In this specification, the value measured by the method described in Examples described later is used as the intrinsic viscosity.

[0118] [Number 1]

[0119]

[0120] In the conjugated diene polymer of the present embodiment, the shape of the branching degree distribution curve obtained by plotting the branching degree (Bn) obtained by the GPC-light scattering method with a viscosity detector against the absolute molecular weight has an extreme value that is convex downward. Therefore, the conjugated diene polymer of the present embodiment tends to have excellent block formability.

[0121] In the past, as a method for manufacturing a polymer with branches, it is known that anions polymerize conjugated diene polymers, react the polymerization termination ends with a coupling modifier having a plurality of functional groups, and thus branch the polymer. In this case, the low molecular weight component is an uncoupled polymer chain and is a straight chain, and the branching curve of the degree of branching is bent according to the number of branches corresponding to the number of functional groups of the coupling modifier, and the number of branches increases in the coupled component to form a high molecular weight. That is, it becomes a curve diagram in which the number of branches increases with the molecular weight, and the degree of branching distribution curve does not have an extreme value.

[0122] In contrast, the conjugated diene polymer of the present embodiment shows a downwardly convex extreme value in the branching distribution curve, which indicates that the low molecular weight polymer has branched, and the increase in the number of branches on the high molecular weight side relative to the extreme value corresponds to the component coupled at the polymerization termination terminal.

[0123] When such a branching degree distribution is exhibited, the following reasons can be cited as the main reasons for improving the block moldability of the conjugated diene polymer, but the reasons are not limited to the following reasons.

[0124] Generally, the greater the absolute molecular weight of a polymer, the more excellent the wear resistance and breaking strength of the polymer. However, when the absolute molecular weight of a polymer with a low degree of branching increases, the particles of the polymer easily fall off from the surface of the briquette, and the briquette formability deteriorates. In addition, there is a tendency that the viscosity during vulcanization increases significantly and the processability during vulcanization deteriorates significantly. Therefore, if it is a polymer with a low degree of branching, even if a large amount of functional groups are introduced into the polymer in order to improve the affinity and / or reactivity of the silicon oxide mixed as a filler, silicon oxide cannot be fully dispersed in the polymer in the mixing process. As a result, the design freedom of molecular weight is limited due to the restriction of processability of the polymer with a low degree of branching.

[0125] On the other hand, the conjugated diene polymer of the present embodiment has a characteristic in that the branching degree distribution curve has a shape of an extreme value convex downward. The shape of the branching degree distribution curve having an extreme value convex downward is formed by keeping the branching degree near the peak of the molecular weight distribution relatively low and increasing the branching degree on the low molecular weight side and the high molecular weight side. Thus, the briquetting property is improved. By making the low molecular weight component also a branched structure, the rise of viscosity during vulcanization accompanied by the rise of the absolute molecular weight can be suppressed.

[0126] From the aspect of making the balance between the branch structure and the viscosity fall into an appropriate range, such a conjugated diene polymer having a branching degree distribution curve with a shape of an extreme value convex downward is obtained by forming a mixture of polymers containing components with different branching degrees. Specifically, it is obtained by adjusting the type and addition amount of the branching agent described later, or using two or more coupling modifiers described later and adjusting their types and respective addition amounts. Thus, the wear resistance, fuel consumption performance and fracture characteristics of the sulfide can be improved without damaging the briquetting formability of the conjugated diene polymer and the processability of the rubber composition.

[0127] (Glass transition temperature of conjugated diene polymer)

[0128] The glass transition temperature (hereinafter also referred to as "Tg") of the conjugated diene polymer of the present embodiment is preferably above -90°C, more preferably above -78°C, and further preferably above -65°C. By setting the glass transition temperature to above -90°C, there is a tendency for excellent processability during vulcanization. In addition, the glass transition temperature of the conjugated diene polymer of the present embodiment is preferably below -10°C, more preferably below -20°C, further preferably below -40°C, further more preferably below -45°C, further preferably below -50°C, and particularly preferably below -55°C. By setting the glass transition temperature to below -10°C, there is a tendency for the sulfide of the conjugated diene polymer to have excellent breaking strength, wear resistance, and low hysteresis loss.

[0129] The glass transition temperature can also be set within the range of any combination of the above upper limit and lower limit. The glass transition temperature of the conjugated diene polymer can be measured according to ISO 22768:2017. In more detail, while heating in a specified temperature range, differential scanning calorimetry (DSC) is performed to record the DSC curve, and the peak (inflection point) of the DSC differential curve is used as the glass transition temperature. Specifically, it can be measured by the method described in the examples described below.

[0130] Due to the microstructure of conjugated diene polymer (bonded vinyl aromatic monomer unit amount, bonded conjugated diene monomer unit amount and the ratio of the vinyl bond amount in the bonded conjugated diene monomer unit) will affect the glass transition temperature of conjugated diene polymer, therefore from the aspect of controlling the glass transition temperature, bonded vinyl aromatic monomer unit amount, vinyl bond amount have a preferred range. In the microstructure of conjugated diene polymer, bonded vinyl aromatic monomer unit amount is not particularly limited, relative to the whole conjugated diene polymer, preferably 1 mass % or more and 40 mass % or less, more preferably 1 mass % or more and 36 mass % or less, further preferably 1 mass % or more and 30 mass % or less, further more preferably 2 mass % or more and 29 mass % or less, further preferably 3 mass % or more and 28 mass % or less, particularly preferably 5 mass % or more and 27 mass % or less. If the bonded vinyl aromatic monomer unit amount is within the above range, there is a tendency that the breaking strength, wear resistance and low hysteresis loss of the sulfide of conjugated diene polymer are more excellent. It should be noted that, as the amount of the bonded vinyl aromatic monomer unit increases, the Tg of the conjugated diene polymer tends to increase, and as it decreases, the Tg tends to decrease.

[0131] In the present specification, the "amount of bonded vinyl aromatic monomer units" refers to the content of the unit derived from the aromatic vinyl compound used as a monomer.

[0132] In the microstructure of the conjugated diene polymer, the amount of the bonded conjugated diene monomer unit is not particularly limited, and is preferably 60% by mass or more and 99% by mass or less, more preferably 64% by mass or more and 99% by mass or less, further preferably 70% by mass or more and 99% by mass or less, further more preferably 71% by mass or more and 98% by mass or less, further preferably 72% by mass or more and 97% by mass or less, and particularly preferably 73% by mass or more and 95% by mass or less. If the amount of the bonded conjugated diene monomer unit is within the above range, the destructive strength, wear resistance and low hysteresis loss of the sulfide of the conjugated diene polymer are more excellent. It should be noted that in this specification, "the amount of the bonded conjugated diene monomer unit" refers to the content of the part of the conjugated diene compound used as a monomer.

[0133] In the microstructure of the conjugated diene polymer, the amount of vinyl bonds in the bonded conjugated diene monomer unit (hereinafter also referred to as "vinyl bond amount") is not particularly limited, and is preferably 11 mol% to 60 mol% relative to the entire bonded conjugated diene monomer unit, more preferably 11 mol% to 40 mol%, further preferably 12 mol% to 35 mol%, further more preferably 13 mol% to 34 mol%, further preferably 14 mol% to 33 mol%, and particularly preferably 15 mol% to 30 mol%. If the vinyl bond amount is within the above range, the linearity of the structure of the conjugated diene part in the conjugated diene polymer is improved, and the entanglement of the polymer chains is strengthened, so there is a tendency to have better breaking strength and wear resistance. In addition, if the vinyl bond amount is within the above range, there is a tendency for its sulfide to have better low hysteresis loss.

[0134] It should be noted that if the amount of vinyl bonds increases, Tg increases; if it decreases, Tg decreases. In this specification, "the amount of vinyl bonds in the bonded conjugated diene monomer unit" refers to the proportion of the part with vinyl bonds in the part derived from the conjugated diene compound used as a monomer (hereinafter referred to as "bonded conjugated diene monomer unit").

[0135] (Relationship between absolute molecular weight curve and degree of branching of polymer)

[0136] As described above, the conjugated diene polymer of the present embodiment preferably has a shape having a downwardly convex extreme value in the branching degree distribution curve near the peak top of the molecular weight distribution curve.

[0137] In the conjugated diene polymer of the present embodiment, the height of the peak top in the absolute molecular weight distribution curve based on the GPC-light scattering method with a viscosity detector (wherein, when there are multiple peak tops in the absolute molecular weight distribution curve, the height of the peak top with the largest absolute molecular weight) Hi is used as a reference, and the degree of branching of the conjugated diene polymer at the highest absolute molecular weight Mw(high) among at least two absolute molecular weights when the height in the absolute molecular weight distribution curve is 1 / 2 of Hi (1 / 2Hi) is set as Bn(high), the degree of branching of the conjugated diene polymer at the lowest absolute molecular weight Mw(low) is set as Bn(low), and the degree of branching of the conjugated diene polymer at the peak top of the absolute molecular weight distribution curve is set as Bn(top), preferably satisfying the following conditions (I) to (III).

[0138] <Condition (I)>

[0139] (Bn(high))-(Bn(top))≧1.0

[0140] <Condition (II)>

[0141] (Bn(low))-(Bn(top))≧0.5

[0142] <Condition (III)>

[0143] (Bn(high)) / (Bn(low))=1.1~2.0

[0144] It should be noted that, for the absolute molecular weight distribution curve, when the peak top is used as a reference to distinguish between the high molecular weight side component and the low molecular weight side component, the branching degree (Bn (high)) of the conjugated diene polymer at the absolute molecular weight Mw (high) and the branching degree (Bn (low)) of the conjugated diene polymer at the absolute molecular weight Mw (low) are equivalent to the average branching degree of each high molecular weight side component and low molecular weight side component.

[0145] Satisfying the above <Condition (I)> (Bn(high))-(Bn(top))≧1.0 and the above <Condition (II)> (Bn(low))-(Bn(top))≧0.5 means that in the above polymer chain as a whole, the degree of branching in the low molecular weight region and the high molecular weight region is high, and the degree of branching in the peak top region of the absolute molecular weight curve is low.

[0146] From the aspects of the block moldability and processability of the conjugated diene polymer during vulcanization, (Bn(high))-(Bn(top)) in the above <Condition (I)> is preferably 1.0 or more, more preferably 1.5 or more, further preferably 1.9 or more, and further preferably 2.4 or more. In addition, (Bn(low))-(Bn(top)) in the above <Condition (II)> is preferably 0.5 or more, more preferably 0.6 or more, further preferably 0.7 or more, and further preferably 0.9 or more.

[0147] The (Bn(high)) / (Bn(low)) in the above-mentioned <condition (III)> is an index showing the positioning of the average degree of branching of the high molecular weight component relative to the average degree of branching of the low molecular weight component, and is preferably 1.1 or more, more preferably 1.2 or more, further preferably 1.25 or more, and further preferably 1.3 or more from the aspects of the block moldability and processability of the conjugated diene polymer during vulcanization. In addition, it is preferably 2.0 or less, more preferably 1.8 or less, further preferably 1.7 or less, further more preferably 1.6 or less, and further preferably 1.5 or less.

[0148] In the conjugated diene polymer of the present embodiment, in order to make the relationship between the absolute molecular weight distribution curve and the degree of branching satisfy the above <Condition (I)> to <Condition (III)>, it is effective to adjust the type and addition amount of the branching agent and the type and addition amount of the coupling modifier in the method for producing the conjugated diene polymer. Specifically, as described below, it is effective to use a branching agent that can constitute a main chain branch structure portion in combination with two or more coupling modifiers having different coupling numbers.

[0149] As described above, the conjugated diene polymer of the present embodiment has a shape having a downwardly convex extreme value in the branching distribution curve showing the relationship between the absolute molecular weight and the degree of branching (Bn). That is, the branching distribution curve has a downwardly convex extreme value near the peak of the absolute molecular weight distribution curve.

[0150] Here, the vicinity of the peak top of the molecular weight distribution curve refers to a range where the absolute molecular weight in the molecular weight distribution curve is not less than Mw(low) and not more than Mw(high).

[0151] Figure 1 This is a schematic diagram showing an example of the relationship between the absolute molecular weight distribution curve and the branching degree distribution curve obtained by the GPC-light scattering measurement method with a viscosity detector.

[0152] Figure 1 In FIG. 1 , the dotted line B and the solid line C are branching degree distribution curves showing the relationship between the absolute molecular weight and the branching degree of the conjugated diene polymer, and the solid line A is an absolute molecular weight distribution curve.

[0153] Generally, in the case of a conjugated diene polymer having a simple star structure formed by reacting a coupling modifier with one of the active terminals of the conjugated diene polymer, Figure 1 As shown by the dotted line B, the degree of branching tends to increase as the molecular weight increases.

[0154] On the other hand, about the conjugated diene polymer of the present embodiment, as shown by the solid line C, the branching degree in the low molecular weight region and the high molecular weight region is high, and has a shape with a downwardly convex extreme value. The extreme value is preferably present near the peak of the absolute molecular weight curve (solid line A) as shown by the solid line C. That is, in the conjugated diene polymer of the present embodiment, not only the branching degree of the high molecular weight component is high, but also the branched structure is introduced into the low molecular weight component, and its branching degree is improved. Thus, even if it is non-oil-filled, its briquetting formability is also excellent. Generally, compared with the high molecular weight component, the low molecular weight component is not easy to become a powdered rubber, and has a tendency to be easily formed into a briquetting, but by further introducing a branched structure into the low molecular weight component, the briquetting formability of the conjugated diene polymer is more excellent.

[0155] It should be noted that, in a conjugated diene polymer containing a vinyl aromatic monomer unit, if the vinyl bond content in the conjugated diene monomer unit and the content of the vinyl aromatic monomer unit are set to be low, there is a tendency that the Tg of the conjugated diene polymer is lowered, and the wear resistance and low hysteresis of the sulfide after being made into an improved state, and therefore there is a demand for designing a polymer having such a structure. On the other hand, if the vinyl bond content and the content of the vinyl aromatic monomer unit are set to be low, there is a negative impact on the moldability when made into a block-shaped briquetting molded body and the processability when made into a sulfide. In particular, for non-oil-extended products that are not easy to be briquetting, the reduction of the vinyl bond content and the content of the vinyl aromatic monomer unit tends to be limited in actual use.

[0156] In view of these problems, the present inventors have found that by limiting the branching distribution curve as described above, even when the conjugated diene polymer is not oil-extended, the block moldability is good. Therefore, in the microstructure design of the non-oil-extended product, the restriction that the vinyl bond amount and the content of the vinyl aromatic monomer unit cannot be reduced is relaxed, and the glass transition temperature can be set low.

[0157] (Mooney viscosity curve)

[0158] The conjugated diene polymer of the present embodiment preferably has two or more extreme values ​​in a Mooney viscosity curve (hereinafter also referred to as “ML curve”) measured at 100°C.

[0159] The Mooney viscosity curve (hereinafter also referred to as "ML curve") is generally obtained by plotting the Mooney viscosity value against the measurement time. For example, in the case of a polymer having a linear structure, the entanglement between polymer chains is slowly untied over time during the Mooney viscosity measurement, thereby forming a Mooney viscosity curve without an extreme value. In addition, in the case of a linear molecular structure and an increased molecular weight, the entanglement between polymer chains is not untied within the measurement time, and the Mooney viscosity curve reaches saturation at a certain Mooney viscosity value, and the attenuation behavior of the Mooney viscosity is not observed.

[0160] On the other hand, in the case of a polymer having a branched structure, there is a tendency for the molecular entanglement to be reduced when compared with a straight-chain polymer of the same molecular weight. Therefore, even in the case of a polymer having a high molecular weight structure, the entanglement between polymer chains is untied within the measurement time, and thus the Mooney viscosity curve tends to have an upward convex extreme value.

[0161] It should be noted that, as described above, Mooney viscosity is an index that indicates the comprehensive characteristics of a conjugated diene polymer, including information on the molecular weight, molecular weight distribution, degree of branching, and content of a softener of the conjugated diene polymer. In addition, the method for determining the Mooney viscosity is specified in ISO 289, and the error of the measured value due to mechanical error is also very small, which is extremely effective in controlling the performance of the conjugated diene polymer.

[0162] In the conjugated diene polymer of the present embodiment, from the aspects of productivity of the conjugated diene polymer, handling stability after the rubber composition is made into a vulcanizate, and breaking strength, it is preferred that the glass transition temperature is within a specific numerical range, the Mooney viscosity curve has two or more extreme values, and more preferably the first extreme value is convex downward and the second extreme value is convex upward. The two extreme values ​​of the Mooney viscosity curve are derived from the case where the branching distribution curve has a shape that is convex downward, and each extreme value is considered to correspond to the relaxation of the low molecular weight component containing a branch structure and the high molecular weight component containing a branch structure, that is, the reduction in the degree of entanglement.

[0163] (Average molecular weight and molecular weight distribution)

[0164] In the conjugated diene polymer of the present embodiment, the weight average molecular weight measured by the GPC measurement method is preferably 35×10 4 More preferably 40×10 4 More preferably, 50×10 4 More preferably, 55×10 4 More preferably, 60×10 4 If the weight average molecular weight measured by GPC is 35×10 4 The weight average molecular weight is preferably 250×10 4 Less than, more preferably 200×10 4 Below, more preferably 150×10 4 Below, more preferably 100×10 4 If the weight average molecular weight is 250×10 4 If the filler has a lower content than the sulfide, the dispersibility of the filler in the sulfide thereof will be further improved, and there is a tendency that practically sufficient fracture characteristics can be obtained.

[0165] The weight average molecular weight may be within a range obtained by arbitrarily combining the above upper limit value and lower limit value.

[0166] The weight average molecular weight of the conjugated diene polymer can be measured by the method described in the examples below.

[0167] In the conjugated diene polymer of the present embodiment, the number average molecular weight measured by the GPC measurement method is preferably 20×10 4 More preferably, 25×10 4 More preferably, 30×10 4 The above number average molecular weight may also be 35×10 4 If the number average molecular weight measured by GPC is 20×10 4 The above number average molecular weight is preferably 100×10 4 Below, more preferably 90×10 4 Below, more preferably 80×10 4 Below, more preferably 70×10 4 If the number average molecular weight is 20×10 4 As described above, the dispersibility of the filler in the sulfide thereof is further improved, and there is a tendency that practically sufficient fracture characteristics can be obtained.

[0168] The number average molecular weight may be within a range formed by arbitrarily combining the above upper limit value and lower limit value.

[0169] The number average molecular weight of the conjugated diene polymer can be measured by the method described in the examples below.

[0170] In the conjugated diene polymer of the present embodiment, from the aspect of processability during vulcanization, the wear resistance of the sulfide, and the breaking strength, the weight average molecular weight (Mw) measured by the GPC determination method relative to the number average molecular weight (Mn) measured by the GPC determination method (Mw / Mn) (molecular weight distribution) is preferably 1.4 or more, more preferably 1.5 or more, further preferably 1.5 or more, and further more preferably 1.6 or more. The upper limit of molecular weight distribution is not particularly limited, and is usually preferably 3.5 or less, more preferably 2.5 or less, further preferably 2.0 or less, and further more preferably 2.0 or less.

[0171] The molecular weight distribution of the conjugated diene polymer can be controlled within the above numerical range by adjusting polymerization conditions such as the monomer, polymerization initiator, type and amount of polar compound added, polymerization time, polymerization temperature, amount and type of coupling modifier added, and combination of two or more when using the coupling modifier.

[0172] (Degree of branching at the extreme value of the branching distribution curve)

[0173] In the branching degree distribution curve of the conjugated diene polymer of the present embodiment, as described above, it is a preferred embodiment that the branching degree distribution curve has a shape having an extreme value that is convex downward near the peak top of the molecular weight distribution curve.

[0174] From the perspectives of processability when the conjugated diene polymer of the present embodiment is vulcanized, abrasion resistance of the vulcanizate, and breaking strength, the degree of branching of the conjugated diene polymer at the downward convex extreme value of the branching distribution curve is preferably 3.0 to 8.0, more preferably 3.0 to 7.0, further preferably 3.0 to 6.0, and even more preferably 3.0 to 5.0.

[0175] The degree of branching of the conjugated diene polymer at the downward convex extreme value of the branching distribution curve can be controlled by the type and addition amount of the branching agent described later. For example, when the degree of branching of the extreme value is less than 3.0, the degree of branching can be controlled to be more than 3.0 by increasing the addition amount of the branching agent or by using a branching agent with a large number of branches (diphenylethylene, etc.). On the contrary, when the degree of branching exceeds 8.0, on the contrary, by reducing the addition amount of the branching agent or changing to a branching agent with a small expected value of the number of branches, the degree of branching can be controlled to be less than 8.0.

[0176] (Modifying Group)

[0177] The conjugated diene polymer according to the present embodiment preferably has a modified group.

[0178] The "modifying group" refers to a functional group having affinity or bonding reactivity with the filler, and an example thereof includes a functional group containing a nitrogen atom.

[0179] The conjugated diene polymer of the present embodiment has such a modified group, and the interaction with the filler is further improved, so when the composition of the conjugated diene polymer comprising the conjugated diene polymer and the filler is made, the destructive strength of the above-mentioned composition is further improved. From the same aspect, the conjugated diene polymer of the present embodiment preferably has a modified group containing a nitrogen atom, and more preferably has a modified group containing a nitrogen atom and a silicon atom. It is also not necessary to make a modified group or a coupling modifier contain both nitrogen atoms and silicon atoms, and the modified group containing only one or the coupling modifier with a modified group can be combined and set according to the mode that the polymer contains nitrogen and silicon.

[0180] (Modification rate)

[0181] In this specification, in the case of obtaining a mixture of a modified conjugated diene polymer and a conjugated diene polymer that is not modified by modifying a conjugated diene polymer using a coupling modifier, "modification rate" represents the content of the total amount of a mixture of a modified conjugated diene polymer component having a specific functional group (which has affinity or bonding reactivity with a filler) in a polymer molecule relative to a conjugated diene polymer in mass %. Therefore, when the above-mentioned specific functional group contains a nitrogen atom, the mass ratio of the conjugated diene polymer containing the nitrogen atom relative to the total amount of a mixture of a conjugated diene polymer is represented.

[0182] In this specification, unless otherwise specified or clearly distinguished such as by describing in parallel as "conjugated diene polymer or modified conjugated diene polymer", "conjugated diene polymer" includes unmodified conjugated diene polymer and modified conjugated diene polymer.

[0183] In addition, when "a conjugated diene polymer or a modified conjugated diene polymer" is described in parallel, "a conjugated diene polymer" means an unmodified conjugated diene polymer.

[0184] For example, in a conjugated diene polymer including a modified conjugated diene polymer obtained by reacting a nitrogen atom-containing modifier with a terminal end, the mass ratio of the modified conjugated diene polymer having a nitrogen atom-containing functional group derived from the nitrogen atom-containing modifier relative to the total amount of the conjugated diene polymer is taken as the modification rate.

[0185] The conjugated diene polymer of the present embodiment is modified with a functional group preferably containing at least a portion of nitrogen atoms (more preferably containing nitrogen atoms and silicon atoms). Such a modified conjugated diene polymer has better processability when mixed with fillers and the like to form a rubber composition, and the wear resistance, breaking strength and low hysteresis loss of the above-mentioned rubber composition after being made into a sulfide also tend to be more excellent. It should be noted that, as described above, it is not necessary to make a modifying group or a coupling modifier contain both nitrogen atoms and silicon atoms, and a modifying group or a coupling modifier containing only one of them can be combined and set in a manner that the modified conjugated diene polymer finally obtained contains both nitrogen and silicon.

[0186] From the aspect of improving the low hysteresis loss in the sulfide, the modification rate of the conjugated diene polymer of the present embodiment is preferably 60% by mass or more, more preferably 65% ​​by mass or more, more preferably 70% by mass or more, further more preferably 75% by mass or more, and further preferably 80% by mass or more relative to the total amount of the conjugated diene polymer. There is no particular limitation on the upper limit of the above-mentioned modification rate, and it can be 100% by mass, can be 98% by mass or less, can be 95% by mass or less, and can also be 90% by mass or less. In addition, when comparing the modified conjugated diene polymers with the same glass transition point, there is a tendency that the modification rate is high and the low hysteresis loss is excellent.

[0187] In the conjugated diene polymer of the present embodiment, the modification rate can be measured by a chromatography method capable of separating the modified component containing the functional group from the non-modified component. As a method using the chromatography method, a gel permeation chromatography column using a polar substance such as silicon oxide that adsorbs specific functional groups as a filler and a method of using an internal standard of the non-adsorbed component for comparison and quantitative determination (column adsorption GPC method) can be cited.

[0188] More specifically, the modification rate can be obtained by calculating the amount of adsorption on the silica column from the difference between the chromatogram obtained by measuring a sample solution containing a sample and a low molecular weight internal standard polystyrene using a polystyrene gel column and the chromatogram obtained by measuring the sample solution using a silica column. Specifically, the modification rate can be measured by the method described in the examples described below.

[0189] In the conjugated diene polymer of the present embodiment, the modification ratio can be controlled within the above numerical range by adjusting the amount of the coupling modifier added and the reaction method between the conjugated diene compound and the modifier.

[0190] For example, a method of performing polymerization using an organic lithium compound having at least one nitrogen atom in its molecule as a polymerization initiator, a method of copolymerizing a monomer having at least one nitrogen atom in its molecule, and a method of using a modifier having the structural formula described below can be combined.

[0191] (Structure of conjugated diene polymer)

[0192] The conjugated diene polymer of the present embodiment is substantially a collection of polymers of different shapes. Since it is a collection of polymers of different branch numbers and molecular weights, the branching degree distribution curve shows a downward convex shape.

[0193] A preferred embodiment is as follows: the component on the lower molecular weight side compared to the extreme value is a forked structure in which the polymer chain branches into a plurality of polymer chains midway, and the component on the higher molecular weight side compared to the extreme value is a structure in which the forked structure forms a plurality of star-shaped branches. The branched portion of the forked structure is referred to as the "main chain branch structure portion", and is preferably an atomic group containing alkoxysilyl and halosilyl heteroatoms as described later. A plurality of conjugated diene polymer chains are bonded to one end of the main chain branch structure portion, and a single chain of another conjugated diene polymer is bonded to the other end, thereby forming a fork portion [A].

[0194] The specific manufacturing method is as follows. A branching agent having a functional group that reacts with the polymerization active ends of a plurality of polymer chains and a portion that continues to polymerize is reacted, and the branching agent is bonded to a plurality of conjugated diene polymer chains and continues to polymerize, thereby forming the above-mentioned "main chain branch structure portion". The single chain of the conjugated diene polymer that continues to polymerize from the branching agent is further bonded to one or more coupling modifiers that form a star-shaped branch structure with more than three branches, thereby forming a star-shaped branched structure (star-shaped polymer structure portion [B]). A portion of the fork-shaped portion [A] is coupled, thereby forming a star-shaped polymer structure portion [B] with more than three branches, and the uncoupled remain in an uncoupled state directly in the form of a polymer having a fork-shaped portion [A], thereby forming a shape in which the molecular weight distribution curve as a whole is convex downward.

[0195] The conjugated diene polymer of the present embodiment is a polymer containing a conjugated diene polymer having the above-mentioned uncoupled fork-shaped portion [A] but not having a star-shaped polymer structure portion [B], and a conjugated diene polymer having a star-shaped polymer structure portion [B] coupled to the above-mentioned fork-shaped portion [A]. This is a preferred embodiment, and their ratios may be arbitrary. Preferably, the mass ratio of the conjugated diene polymer having only the uncoupled fork-shaped portion [A] is increased relative to the conjugated diene polymer having the star-shaped polymer structure portion [B].

[0196] The "main chain branch structure" as used herein refers to a structure in which a polymer chain forms a branch point and a polymer chain (arm) further extends from the branch point. Typically, the number of branch points formed by a portion derived from a vinyl monomer containing an alkoxysilyl group or a halosilyl group is 2 or more, preferably 3 or more, and more preferably 4 or more.

[0197] The "star polymer structure" as used herein refers to a structure in which three polymer chains (arms) are bonded from one central branch point. The branches from the star polymer structure are preferably 3 or more, more preferably 4 or more, further preferably 6 or more, and further preferably 8 or more.

[0198] In addition, the central branch point mentioned here is a group (atomic group) of substituents containing atoms derived from the coupling modifier or nitrogen atoms derived from the modifier, and does not mean a single atom. For example, a group having an alkoxysilyl group separated from the amino group by 1 to 5 carbon atoms, preferably 2 to 3 carbon atoms is a representative central branch point.

[0199] <Main Chain Branch Structure and Branching Agent>

[0200] The vinyl monomer containing an alkoxysilyl group or a halosilyl group used to construct the "main chain branch structure" referred to in this specification is referred to as a "branching agent".

[0201] As the branching agent, a vinyl monomer containing an alkoxysilyl group or a halosilyl group represented by the following formula (1) or (2) is preferably used. That is, the "main chain branch structure" is preferably composed of an atomic group derived from a vinyl monomer containing an alkoxysilyl group or a halosilyl group represented by the following formula (1) or (2).

[0202] [Chemistry 1]

[0203]

[0204] [Chemistry 2]

[0205]

[0206] In formula (1), R 1 The group represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and a part of the group may have a branched structure.

[0207] R 2 ~R 3 Each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and a part of them may have a branched structure. 1 ~R 3 Each one is independent.

[0208] X 1 represents an independent halogen atom.

[0209] m represents an integer of 0 to 2, n represents an integer of 0 to 3, and l represents an integer of 0 to 3. (m+n+l) represents 3.

[0210] In formula (2), R 4 ~R 7 Each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and a part of them may have a branched structure.

[0211] When there are multiple R4 ~R 7 Each one is independent.

[0212] X 2 ~X 3 represents an independent halogen atom.

[0213] m represents an integer of 0 to 2, n represents an integer of 0 to 3, and l represents an integer of 0 to 3.

[0214] (m+n+l) means 3.

[0215] a represents an integer of 0 to 3, b represents an integer of 0 to 2, and c represents an integer of 0 to 3. (a+b+c) represents an integer of 3.

[0216] The conjugated diene polymer of the present embodiment preferably has a monomer unit based on a compound represented by the above formula (1), and R of the above formula (1) 1 It is a hydrogen atom, m=0.

[0217] This increases the number of branches in the entire conjugated diene copolymer, thereby achieving effects of improving abrasion resistance and processability.

[0218] The conjugated diene polymer of the present embodiment is preferably a modified conjugated diene polymer having a monomer unit based on a compound represented by the above formula (2), wherein m=0 and b=0.

[0219] This can improve the wear resistance and processability.

[0220] The conjugated diene polymer of the present embodiment preferably has a monomer unit based on a compound represented by formula (1), and R 1 It is a hydrogen atom, m=0, l=0.

[0221] This increases the degree of branching of the entire conjugated diene copolymer, thereby achieving effects of improving abrasion resistance and processability.

[0222] The conjugated diene polymer of the present embodiment is preferably a conjugated diene polymer having a monomer unit based on a compound represented by the above formula (2), wherein m=0, l=0, a=0, and b=0.

[0223] This can improve wear resistance and processability.

[0224] Furthermore, the conjugated diene polymer of the present embodiment is more preferably a conjugated diene polymer having a monomer unit based on a compound represented by the above formula (1), wherein R 1 It is a hydrogen atom, l=0, and n=3.

[0225] This improves the modification rate and the degree of branching, and can achieve the effects of improving fuel efficiency, wear resistance, and processability.

[0226] <Long-handled forked conjugated diene polymer>

[0227] The structure in which the single chain of the fork-shaped part [A] is long is called a long-handled fork. This structure can also be formed by continuous polymerization of a single chain, but when the long-handled fork-shaped conjugated diene polymer and the polymer having a three-branched or more star-shaped polymer structure part [B] to which one or more fork-shaped parts [A] are bonded are simultaneously produced, it is appropriate to adopt a method in which the single chain of the fork-shaped part [A] is reacted with a two-branched coupling modifier.

[0228] The long-handled fork-shaped conjugated diene polymer is constructed by continuously polymerizing to increase the molecular weight after constructing the comb-shaped structure part from the main chain branch structure. It is preferred that the molecular weight is increased by continuously polymerizing after constructing the comb-shaped structure part from the main chain branch structure, and then modified with a coupling modifier having a function of less than 2. It is more preferred to use a coupling modifier having a function of 2 to further increase the molecular weight of the handle part.

[0229] The long-shank forked conjugated diene polymer having a single-chain side structure of the fork-shaped portion [A] preferably contains a structure having a nitrogen atom-containing group represented by any of the following general formulas (3), (4-1) and (4-2) in the long-shank portion.

[0230] [Chemistry 3]

[0231]

[0232] In formula (3), P 1 , P 2 They are polymer chains, one of which is a fork-shaped portion [A] having a main chain branch structure portion, and the other is a linear polymer chain without a branch structure.

[0233] R 8 is a hydrocarbon group or hydrocarbon group having 1 to 20 carbon atoms, R 10 It is a hydrocarbon group having 1 to 20 carbon atoms, may be substituted with an organic group containing S, O or N having no active hydrogen, may have an unsaturated bond, and each may be the same or different.

[0234] R 11 , R 12 is an aliphatic hydrocarbon group having 1 to 6 carbon atoms, which may have an unsaturated bond, and each may be the same or different, R 13 It is a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with an organic group containing Si, O or N and having no active hydrogen, and may have an unsaturated bond.

[0235] [Chemistry 4]

[0236]

[0237] [Chemistry 5]

[0238]

[0239] In the above formulas (4-1) and (4-2), P 1 , P 2 They are polymer chains, one of which is a fork-shaped portion [A] having a main chain branch structure, and the other is a linear polymer chain without a branch structure.

[0240] R 14 , R 15 is a hydrocarbon group or hydrocarbon group having 1 to 20 carbon atoms, R 16 It is a hydrocarbon group having 1 to 20 carbon atoms, may have an unsaturated bond, may be substituted with an organic group containing O or N and having no active hydrogen, and each may be the same or different.

[0241] R 17 , R 18 It is a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with an organic group containing Si, O or N and having no active hydrogen, and may have an unsaturated bond.

[0242] <Conjugated diene polymer having a star-shaped polymer structure [B]>

[0243] The conjugated diene polymer having a star-shaped polymer structure [B] is a conjugated diene polymer having a star-shaped polymer structure with three or more branches, which is constructed by continuously polymerizing after constructing a comb-shaped structure portion derived from a main chain branch structure, and then modifying it with a coupling modifier having three or more functionalities. The conjugated diene polymer has a portion derived from a vinyl monomer containing an alkoxysilyl group or a halosilyl group in at least one branch of the star-shaped structure. Regarding the method for obtaining a conjugated diene polymer having a main chain branch structure in the portion derived from a vinyl monomer containing an alkoxysilyl group or a halosilyl group, the above-mentioned "star-shaped polymer structure" can be formed by adjusting the number of functional groups of the modifier and the amount of the modifier added, and the "main chain branch structure" can be controlled by adjusting the number of functional groups of the branching agent, the amount of the branching agent added, and the timing of adding the branching agent.

[0244] <Conjugated diene polymer having a star-shaped polymer structure [B]>

[0245] The conjugated diene polymer of the present embodiment preferably has a structure having a nitrogen atom-containing group represented by any of the following general formulae (5-1) to (5-4), (7-1) to (7-2), (8), and (9-1) to (9-2) in its star-shaped branched structure.

[0246] [Chemistry 6]

[0247]

[0248] [Chemistry 7]

[0249]

[0250] [Chemistry 8]

[0251]

[0252] [Chemistry 9]

[0253]

[0254] In the above formulas (5-1) to (5-4), R is a hydrocarbon group with a valence of 2 or more, or a divalent organic group with a valence of 2 or more having at least one polar group selected from polar groups having oxygen such as ether, epoxy, ketone, polar groups having sulfur such as thioether, thioketone, and polar groups having nitrogen such as tertiary amino, imino, etc.

[0255] The hydrocarbon group with a valency of more than 2 is saturated or unsaturated and may be straight-chain, branched or cyclic, including alkylene, alkenylene and phenylene. Preferably, the hydrocarbon group has 1 to 20 carbon atoms. For example, methylene, ethylene, butylene, cyclohexylene, 1,3-bis(methylene)-cyclohexane, 1,3-bis(ethylene)-cyclohexane, o-phenylene, m-phenylene, p-phenylene, m-xylene, p-xylene, bis(phenylene)-methane and the like can be cited.

[0256] In the above formulas (5-1) to (5-4), R 24 , R 27 is a hydrocarbon group having 1 to 10 carbon atoms, R 24 , R 27 They can be the same as or different from each other.

[0257] In the above formulas (5-1) to (5-4), R 25 , R 28 is hydrogen or a hydrocarbon group having 1 to 10 carbon atoms, R 25 , R 28 They can be the same as or different from each other.

[0258] In the above formulas (5-1) to (5-4), P 3 , P 4It is a polymer chain and has a forked portion [A] of a main chain branch structure or a linear polymer chain without a branch structure.

[0259] In the above formulas (5-1) to (5-4), R 26 It is a hydrocarbon group having 1 to 10 carbon atoms, or a structure of the following formula (6-1) to (6-3).

[0260] [Chemistry 10]

[0261]

[0262] [Chemistry 11]

[0263]

[0264] [Chemistry 12]

[0265]

[0266] In the above formulas (5-1) to (5-4), R 24 , R 25 , R 26 It can be a ring structure bonded to each other.

[0267] In the above formulas (5-1) to (5-4), R 26 In the case of a hydrocarbon group, it may be a cyclic structure bonded to R. In the case of the above cyclic structure, it may be a cyclic structure bonded to R 26 The N on the molecule is directly bonded to the R.

[0268] In the above formulae (5-1) to (5-4), f is an integer of 1 or more, and g is an integer of 0 or 1 or more.

[0269] In the above formulas (6-1) to (6-3), R 29 , R 30 Respectively with R of the above formulas (5-1) to (5-4) 24 , R 25 Similarly, in the above formulas (6-1) to (6-3), P 5 With the above formula (5-1) ~ (5-4) P 3 , P 4 Defined similarly.

[0270] R 29 , R 30 They can be the same as or different from each other.

[0271] [Chemistry 13]

[0272]

[0273] [Chemistry 14]

[0274]

[0275] In the above formulas (7-1) to (7-2), P 6 , P 7 It is a polymer chain, and is a forked portion [A] having a main chain branch structure or a linear polymer chain having no branch structure.

[0276] P 6 , P 7 When there are multiple bonds (when h, i or j is an integer greater than 2), P 6 , P 7 They may be the same as or different from each other.

[0277] R 33 , R 34 Each independently represents an alkyl group or hydrocarbon group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and R 35 represents an alkylene group having 1 to 10 carbon atoms, R 36 It represents an alkylene group having 1 to 20 carbon atoms.

[0278] h represents an integer of 1 to 3, i represents an integer of 1 to 3, j represents an integer of 1 or 2, and (h+i) and (h+j) represent integers of 3 or more.

[0279] [Chemistry 15]

[0280]

[0281] In the above formula (8), P 8 , P 9 , P 10 It is a polymer chain and has a forked portion [A] of a main chain branch structure or a linear polymer chain without a branch structure.

[0282] P 8 , P 9 , P 10 When there are multiple bonds (when m, n or l is an integer greater than 2), P 8 , P 9 , P 10 They may be the same as or different from each other.

[0283] R 40 ~R 42 Each independently represents an alkyl group or hydrocarbon group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and R 43 ~R 45 Each independently represents an alkylene group having 1 to 20 carbon atoms.

[0284] m, n and l each independently represent an integer of 1 to 3, and (m+n+l) represents an integer of 3 or more.

[0285] [Chemistry 16]

[0286]

[0287] [Chemistry 17]

[0288]

[0289] In the above formulas (9-1) to (9-2), P 11 ~P 14 It is a polymer chain and has a forked portion [A] of a main chain branch structure or a linear polymer chain without a branch structure. 11 , P 12 When a plurality of bonds are formed (when o or p is an integer greater than 2), P 11 , P 12 They may be the same as or different from each other.

[0290] R 46 ~R 48 Each independently represents a single bond or an alkylene group having 1 to 20 carbon atoms, and R 49 and R 51 Each independently represents an alkyl group or a hydrocarbon group having 1 to 20 carbon atoms, R 53 and R 56 Each independently represents an alkylene group having 1 to 20 carbon atoms, and R 55 The alkyl group or trialkylsilyl group having 1 to 20 carbon atoms may be substituted with an organic group containing S, O or N and having no active hydrogen, may have an unsaturated bond, and may be the same or different.

[0291] o represents an integer of 1 to 3, p represents 1 or 2, and t represents an integer of 1 to 3.

[0292] When there are multiple R 46 ~R 56 , o, p and t are independent of each other and may be the same or different.

[0293] q represents an integer of 0-6, r represents an integer of 0-6, s represents an integer of 0-6, and (q+r+s) is an integer of 4-10.

[0294] A represents a hydrocarbon group having 1 to 20 carbon atoms; or an organic group having at least one atom selected from the group consisting of an oxygen atom, a nitrogen atom, a silicon atom, a sulfur atom and a phosphorus atom and having no active hydrogen.

[0295] In the above formulae (9-1) to (9-2), A is preferably represented by any one of the following general formulae (I) to (IV).

[0296] [Chemistry 18]

[0297]

[0298] In the above formula (I), B 1 represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, and u represents an integer of 1 to 10. When there are plural B 1 Each one is independent.

[0299] [Chemistry 19]

[0300]

[0301] In the above formula (II), B 2 represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, B 3 represents an alkyl group having 1 to 20 carbon atoms, and u represents an integer of 1 to 10. When there are plural numbers of B 2 and B 3 Each one is independent.

[0302] [Chemistry 20]

[0303]

[0304] In the above formula (III), B 4 represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, and u represents an integer of 1 to 10. When there are plural B 4 Each one is independent.

[0305] [Chemistry 21]

[0306]

[0307] In the above formula (IV), B 5 represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, and u represents an integer of 1 to 10. When there are plural B 5 Each one is independent.

[0308] [Molding body]

[0309] The molded product of the present embodiment is a molded product containing the conjugated diene polymer of the present embodiment described above. From the viewpoint of handling properties, a sheet-like or block-like molded product is preferred.

[0310] The size and thickness of the sheet-shaped or block-shaped molded product are not particularly limited, and examples thereof include a sheet-shaped molded product having a thickness of about 1 cm, a 1,000 cm thick molded product, and a 1,000 cm thick molded product. 3A rectangular or cubic block-shaped body.

[0311] The molded body of the present embodiment is more preferably a block-shaped molded body, and the block shape is preferably a substantially rectangular parallelepiped, and more preferably 1,000 cm 3 The above block-shaped (briquette) molded body. Moreover, a rectangular parallelepiped briquette of 17.5 kg to 35 kg is more preferable.

[0312] As a molding method of the molded body of the present embodiment, for example, it is preferable to produce a molded body having a specific surface area of ​​0.7 m 2 / g~3.2m 2 / g of pellets, and a method of compression molding the pellets. From the viewpoint of moldability, it is preferred to further perform a step of sieving the pellets before molding.

[0313] When the pellets are subjected to compression molding, since the pellets are closely attached to each other, the specific surface area of ​​the molded body is smaller than the specific surface area of ​​the pellets. The close adhesion of the pellets during compression molding can be controlled by adjusting the molecular weight, composition, structure, rubber softener composition, temperature and pressure during compression of the conjugated diene polymer. For example, in the case of wishing to improve the close adhesion of the pellets and reduce the specific surface area of ​​the compact, it is preferred to apply the conditions of reducing the molecular weight of the conjugated diene polymer, increasing the amount of rubber softener, and increasing the temperature and pressure during compression.

[0314] The specific surface area of ​​the molded article of this embodiment is preferably 0.005 to 0.05 m 2 / g, and more preferably 0.01 to 0.04 m / g from the viewpoint of film packaging properties. 2 / g. By making the specific surface area of ​​the molded body 0.005m 2 / g or more, the expansion of the compact can be suppressed, and the specific surface area of ​​the molded body can be made to be 0.05m 2 / g or less is preferred because the separation of the pellets from the molded body can be reduced.

[0315] The specific surface area of ​​the molded body can be obtained by the BET method.

[0316] Generally, since the specific surface area of ​​a large-sized molded body may differ depending on the position of the molded body, it is preferable to collect from the vicinity of the center of the molded body.

[0317] The granules are preferably sieved according to particle size before molding, and then mixed in an appropriate amount ratio.

[0318] When the specific surface area of ​​the molded body formed directly using the desolventized granules exceeds the upper limit of the above range, it is preferred to increase the composition of large-size granules and reduce the composition of small-size granules in the granules obtained by screening. When the specific surface area does not meet the lower limit, it is preferred to reduce the composition of large-size granules and increase small-size granules.

[0319] The molding compression pressure of the molded body is preferably 3 to 30 MPa, more preferably 10 to 20 MPa. When the compression pressure during molding is 30 MPa or less, the device can be designed compactly and the installation efficiency is good; when the compression pressure during molding is 3 MPa or more, the moldability is good. When the moldability is good, the surface of the molded body is smooth, the polymer will not peel off after the molding process, and there is a tendency to suppress expansion after molding.

[0320] The temperature of the conjugated diene polymer or the rubber composition containing the conjugated diene polymer during molding is preferably 30 to 120° C., and more preferably 50 to 100° C. from the viewpoint of reducing residual solvent and suppressing thermal degradation.

[0321] When the temperature during molding is 30° C. or higher, moldability is good, while when the temperature is 120° C. or lower, gel formation due to thermal degradation of the rubber composition can be suppressed, which is preferred.

[0322] The higher the temperature and pressure during molding, the smaller the specific surface area of ​​the compact.

[0323] The holding time during molding is preferably 3 to 30 seconds, more preferably 5 to 20 seconds. When the holding time during compression is 30 seconds or less, production efficiency is good, and when it is 5 seconds or more, moldability is good.

[0324] In order to avoid close contact between the molded bodies, the molded body of the present embodiment is preferably packaged with a resin film (packaging sheet).

[0325] As the type of the resin of the film, for example, polyethylene, ethylene copolymer resin, polystyrene, high-impact polystyrene, and PET can be used.

[0326] From the viewpoint of ease of handling during transportation of the molded product and the fact that condensation is less likely to occur in the gap between the packaging sheet and the agglomerate, it is preferred that the packaging sheet have good adhesion.

[0327] The molded article of this embodiment is used, for example, for storage in a transport container. If the expansion rate of the molded article after one day from molding is less than 5%, the storage property in the container is good, which is preferable.

[0328] The sheet-shaped or block-shaped molded product using the conjugated diene polymer of the present embodiment may contain a softener component described later. However, in the molded product of the present embodiment, from the perspective of increasing the degree of freedom in compounding during the production of the rubber composition described later, the softener component is preferably 2 parts by mass or less, more preferably 1.5 parts by mass or less, further preferably 1 part by mass or less, further more preferably less than 1 part by mass, and most preferably no softener component is added, relative to 100 parts by mass of the conjugated diene polymer.

[0329] It should be noted that the softener component used in the production of the rubber composition described below is sometimes referred to as a "rubber softener" to distinguish it from the softener component used in the molded product of the conjugated diene polymer in words, but not to distinguish the materials themselves.

[0330] [Method for producing conjugated diene polymer]

[0331] Hereinafter, the method for producing the conjugated diene polymer according to the present embodiment will be described in detail.

[0332] By using the method for producing a conjugated diene polymer according to the present embodiment, the conjugated diene polymer can be obtained reliably and simply. However, the conjugated diene polymer according to the present embodiment is not limited to the polymer produced by the following production method.

[0333] The method for producing a conjugated diene polymer of the present embodiment comprises the following steps: a step of polymerizing a conjugated diene compound and, if necessary, a vinyl aromatic compound using an organic metal compound represented by an organic lithium compound as a polymerization initiator; a step of adding a branching agent to obtain a conjugated diene polymer having a branched structure (hereinafter sometimes collectively referred to as a polymerization branching step); and a step of adding a coupling modifier.

[0334] In the method for producing a conjugated diene polymer according to the present embodiment, it is preferred to add two or more coupling modifiers having different coupling numbers.

[0335] The polymerization reaction of conjugated diene compound and aromatic vinyl compound is preferably the polymerization carried out by the growth reaction based on living anionic polymerization reaction, thus can obtain the conjugated diene polymer with active terminal.As a result, when branching agent is added, conjugated diene polymer reacts efficiently with branching agent.In addition, the manufacture method of the present embodiment also has the tendency that can react efficiently when there is coupling step described later.

[0336] Examples of the polymerization reaction form include, but are not limited to, a batch-type (hereinafter also referred to as a "batch-type") and a continuous-type polymerization reaction form.

[0337] In the continuous method, one or more reactors connected together can be used. As the continuous reactor, for example, a tank-type or tube-type reactor with a stirrer is used. In the continuous method, preferably, monomers, an inert solvent described later, and a polymerization initiator described later are continuously loaded into the reactor, a polymer solution containing a polymer is obtained in the reactor, and the polymer solution is continuously discharged.

[0338] As a batch reactor, for example, a tank reactor with a stirrer is used. In the batch reactor, preferably, monomers, an inert solvent described below, and a polymerization initiator described below are loaded, and monomers are added continuously or intermittently during polymerization as required to obtain a polymer solution containing a polymer in the reactor, and the polymer solution is discharged after the polymerization is completed.

[0339] In the production method of the present embodiment, the polymerization reaction is preferably carried out in a continuous polymerization reaction format in which the polymer can be continuously discharged and provided for the next reaction in a short time, because a conjugated diene polymer having an active terminal can be obtained at a high ratio.

[0340] (Polymerization branching process)

[0341] The polymerization branching step in the method for producing the conjugated diene polymer of the present embodiment is a step of obtaining a conjugated diene polymer having a branched structure by polymerizing at least a conjugated diene compound and, if necessary, a vinyl aromatic compound using a polymerization initiator such as an organolithium compound described later and adding a branching agent. Therefore, in the polymerization branching step, before adding the branching agent, the polymerization reaction of at least the conjugated diene compound and the aromatic vinyl compound is the main reaction, and the branching reaction is initiated after adding the branching agent.

[0342] As the monomer used in the polymerization branching step, i.e., the conjugated diene compound and the vinyl aromatic compound, at least one of the above-mentioned conjugated diene compound and at least one of the above-mentioned vinyl aromatic compound may be used. In addition, from the aspect that a nitrogen atom can be introduced into the conjugated diene polymer, as the above-mentioned conjugated diene compound or the above-mentioned vinyl aromatic compound, a derivative substituted by a mode having at least one nitrogen atom in the molecule may be used.

[0343] The polymerization initiator is not particularly limited, and for example, an organic lithium compound such as an organic monolithium compound can be used.

[0344] Examples of the organic monolithium compound include compounds having a carbon-lithium bond, compounds having a nitrogen-lithium bond, and compounds having a tin-lithium bond in terms of the bonding form between the organic group and the lithium.

[0345] Among them, the organic monolithium compound is preferably an organic lithium compound having at least one nitrogen atom in the molecule, and more preferably an alkyl lithium compound having a substituted amino group or a dialkyl lithium amide, from the viewpoint of being able to introduce a nitrogen atom into the conjugated diene polymer.

[0346] The substituted amino group refers to an amino group having no active hydrogen or an amino group in which the active hydrogen is protected.

[0347] Examples of the alkyl lithium compound having an amino group without active hydrogen include, but are not limited to, piperidinyl lithium, 3-dimethylaminopropyl lithium, 3-diethylaminopropyl lithium, 4-(methylpropylamino)butyl lithium, and 4-hexamethyleneiminobutyl lithium.

[0348] Examples of the alkyl lithium compound having an amino group with protected active hydrogen include, but are not limited to, 3-bistrimethylsilylaminopropyllithium and 4-trimethylsilylmethylaminobutyllithium.

[0349] Examples of the dialkyl lithium amide include, but are not limited to, dimethyl lithium amide, diethyl lithium amide, dipropyl lithium amide, dibutyl lithium amide, di-n-hexyl lithium amide, diheptyl lithium amide, diisopropyl lithium amide, dioctyl lithium amide, di-2-ethylhexyl lithium amide, didecyl lithium amide, ethylpropyl lithium amide, ethylbutyl lithium amide, ethylbenzyl lithium amide, methylphenethyl lithium amide, hexamethylene imide, lithium pyrrolidine, lithium piperidine, lithium heptamethylene imide, lithium morpholine, 1-lithioazacyclooctane, 6-lithio-1,3,3-trimethyl-6-azabicyclo[3.2.1]octane, and 1-lithio-1,2,3,6-tetrahydropyridine.

[0350] These organic monolithium compounds having a substituted amino group can also be used as organic monolithium compounds that are soluble oligomers by reacting a small amount of a polymerizable monomer such as 1,3-butadiene, isoprene, or styrene.

[0351] When the polymerization initiator has a nitrogen atom constituting an amino group, a chain transfer reaction is likely to occur during anionic polymerization, and the reaction amount of the coupling modifier relative to the active terminal after the polymerization is completed tends to decrease. As a result, when a polymerization initiator having a nitrogen atom constituting an amino group is used, the weight average molecular weight tends to decrease.

[0352] Therefore, at a weight average molecular weight of 35×10 4 Above, 40×10 4 Above, 45×10 4 Above or 60×10 4In the case of the polymers with higher molecular weights, when it is desired to set a high modification rate, it is preferred to react the nitrogen atom at the polymerization termination terminal side rather than the polymerization start terminal side. That is, it tends to be difficult to produce polymers with higher molecular weights and containing nitrogen atoms at both ends. Although it depends on the weight-average molecular weight and the structure of the coupling modifier, when there is only a nitrogen atom at the termination terminal side, the nitrogen content of the polymer is usually 3 mass ppm to 500 mass ppm.

[0353] As the organic monolithium compound, an alkyl lithium compound can be used from the viewpoint of ease of industrial availability and ease of polymerization reaction control. When such an organic monolithium compound is used, a conjugated diene polymer having an alkyl group at the polymerization initiation terminal can be obtained.

[0354] Examples of the alkyl lithium compound include, but are not limited to, n-butyl lithium, sec-butyl lithium, tert-butyl lithium, n-hexyl lithium, benzyl lithium, phenyl lithium, and stilbene lithium.

[0355] As the alkyl lithium compound, n-butyl lithium and sec-butyl lithium are preferred from the viewpoint of ease of industrial availability and ease of polymerization reaction control.

[0356] These organic monolithium compounds may be used alone or in combination of two or more, or may be used in combination with other organic metal compounds.

[0357] Examples of other organic metal compounds include, but are not limited to, alkaline earth metal compounds, alkali metal compounds other than lithium, and other organic metal compounds.

[0358] Examples of the alkaline earth metal compound include, but are not limited to, organomagnesium compounds, organocalcium compounds, and organostrontium compounds. In addition, alkoxides, sulfonates, carbonates, and amide compounds of alkaline earth metals may also be polymerized.

[0359] Examples of the organomagnesium compound include, but are not limited to, dibutylmagnesium and ethylbutylmagnesium.

[0360] Examples of other organometallic compounds include, but are not limited to, organoaluminum compounds.

[0361] The amount of polymerization initiator added is preferably determined according to the molecular weight of the target conjugated diene polymer. The number average molecular weight and / or weight average molecular weight can be controlled by the ratio of the amount of monomer added relative to the amount of polymerization initiator added. Specifically, if the ratio of the amount of polymerization initiator added is reduced, the molecular weight tends to increase; if the ratio of the amount of polymerization initiator added is increased, the molecular weight tends to decrease.

[0362] From the aspect of obtaining the conjugated diene polymer of the present embodiment reliably and simply, the polymerization branching step is preferably carried out in an inert solvent. Such an inert solvent may include, but is not limited to, hydrocarbon solvents such as saturated hydrocarbons and aromatic hydrocarbons. Specific hydrocarbon solvents may include, but are not limited to, aliphatic hydrocarbons such as butane, pentane, hexane, and heptane; alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclopentane, and methylcyclohexane; aromatic hydrocarbons such as benzene, toluene, and xylene; and hydrocarbons consisting of mixtures thereof.

[0363] From the aspect of obtaining a conjugated diene polymer formed by random polymerization of a conjugated diene compound and a vinyl aromatic compound, the polymerization reaction in the polymerization branching step can be carried out by, for example, the following method described in Japanese Patent Application Laid-Open No. 59-140211. That is, the following method can be used: first, the total amount of the vinyl aromatic compound and a part of the conjugated diene compound are used to initiate the polymerization reaction, and then the remaining conjugated diene compound is intermittently added in the middle of the polymerization reaction.

[0364] The polymerization temperature in the polymerization reaction of the polymerization branching step is not particularly limited, and is preferably a temperature for performing living anionic polymerization. In addition, from the perspective of improving productivity, it is more preferably above 0°C, and further preferably above 0°C and below 120°C. By making the polymerization temperature in the polymerization reaction within the above range, there is a tendency to fully improve the reactivity with the coupling modifier in the coupling step described later. From the same perspective, the polymerization temperature in the polymerization reaction is further more preferably above 50°C and below 100°C.

[0365] Polar compounds can be added in the polymerization branching step. When polar compounds are added, there is a tendency to obtain a conjugated diene polymer in which a vinyl aromatic compound and a conjugated diene compound are further randomly copolymerized. In this way, polar compounds have an effective randomization effect in the copolymerization of conjugated diene compounds and vinyl aromatic compounds, and can therefore be used as a distribution regulator of vinyl aromatic compounds and a regulator of styrene block amount. In addition, polar compounds can promote polymerization reaction, and can also be used as a vinylating agent for controlling the microstructure of conjugated diene polymers.

[0366] In this way, since polar compounds are used as vinylating agents, randomizing agents and polymerization accelerators, for example, in order to adjust the vinylization rate and the randomization rate, the polymerization promotion effect also tends to decrease when the polar compounds are reduced. Therefore, in the method for adjusting the degree of branching of a polymer by reacting a coupling modifier with the polymerization termination end, when the addition amount of the polar compound is reduced, the polymerization time becomes longer and the ratio of the polymerization termination end that is inactivated increases. As a result, such a method has a tendency to be difficult to improve the modification rate. That is, when it is desired to adjust the degree of branching of the modified conjugated diene polymer by the adjustment of the addition amount of the polar compound and the reaction with the coupling modifier, it is difficult to control the tendency of the vinylization rate and the randomization rate. In this regard, in the manufacture method of the present embodiment, the degree of branching of the polymer can be improved by the branching agent described later, so the degree of branching can be controlled independently with the vinylization rate and the randomization rate, which is advantageous in the structural design of the conjugated diene polymer.

[0367] As polar compounds, there can be mentioned, but are not limited to, ethers such as tetrahydrofuran, diethyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, dimethoxybenzene, and 2,2-bis(2-tetrahydrofuranyl)propane; tertiary amine compounds such as tetramethylethylenediamine, dipiperidylethane, trimethylamine, triethylamine, pyridine, and quinuclidine; alkali metal alkoxide compounds such as potassium tert-amylate, potassium tert-butoxide, sodium tert-butoxide, and sodium amylate; and phosphine compounds such as triphenylphosphine, etc. These polar compounds can be used alone or in combination of two or more.

[0368] The amount of polar compound added is not particularly limited and can be adjusted according to the amount of polymerization active ends, that is, the amount of polymerization initiator added. As the amount of polar compound added, for example, relative to 1 mol of polymerization initiator, it is preferably 0.010 mol or more and 1.0 mol or less, more preferably 0.10 mol or more and 0.70 mol or less. The amount of polar compound added can be 0.60 mol or less or 0.50 mol or less relative to 1 mol of polymerization initiator within the above range. Alternatively, it can be 0.15 mol or more or 0.20 mol or more relative to 1 mol of polymerization initiator. When the amount of polar compound added is below the above upper limit, there is a tendency to obtain a conjugated diene polymer with low Tg. In addition, when the amount of polar compound added is above the above lower limit, the deactivation of the polymerization active end can be suppressed, and the coupling rate in the coupling process described later tends to increase. The amount of polar compound added can be within the range of any combination of the above upper limit and lower limit.

[0369] In the method for producing the conjugated diene polymer of the present embodiment, there may be a process for removing impurities before the polymerization branching process. In particular, when the above-mentioned monomer, polymerization initiator and / or inert solvent contain propadiene and acetylene as impurities, it is preferred to have a process for removing impurities before the polymerization branching process. By having a process for removing impurities, a conjugated diene polymer with a high concentration of active ends tends to be obtained, and a modified conjugated diene polymer with a high modification rate tends to be obtained in the coupling process described later. There is no particular limitation on such a process for removing impurities, and for example, a process for treating with an organic metal compound can be cited. There is no particular limitation on such an organic metal compound, and for example, an organic lithium compound can be cited. There is no particular limitation on such an organic lithium compound, and for example, n-butyl lithium can be cited.

[0370] In the polymerization branching process, by adding the branching agent described later, a branching reaction is initiated in the conjugated diene polymer. After adding the branching agent, the polymerization reaction of the growth of the conjugated diene polymer and the branching reaction of the conjugated diene polymer branch are competitively produced in the reaction system. Therefore, the weight average molecular weight, number average molecular weight, their ratio (Mw / Mn) and absolute molecular weight of the conjugated diene polymer obtained in the polymerization branching process can be controlled by adjusting the type and addition of the branching agent and the timing of adding the branching agent, and the degree of branching of the conjugated diene polymer, the number of branching points, and the number of branches at the branching points.

[0371] In addition, by adding branching agent in the polymerization of conjugated diene polymer, the total amount of the active end of the conjugated diene polymer in the reaction system can be reduced compared to the addition of polymerization initiator, even if the polar compound added is reduced, the reaction in the initial stage of polymerization can be promoted, and the activity of the polymerization active end can be maintained. As a result, for the conjugated diene polymer of the present embodiment that is in the above-mentioned specific range of bonding vinyl aromatic monomer unit amount and vinyl bonding amount, the coupling rate and / or the modification rate of the polymerization termination end can be easily improved. But the conjugated diene polymer of the present embodiment is not necessary to react with the coupling modifier.

[0372] As described above, in the manufacture method of the conjugated diene polymer of the present embodiment, in order to control the microstructure of the bonding vinyl aromatic monomer unit amount and the vinyl bonding amount, the addition amount of the polar compound can be adjusted. When the addition amount of the polar compound commonly used in order to make the bonding vinyl aromatic monomer unit amount and the vinyl bonding amount become the above-mentioned specific range, when the branching agent is not added, it is insufficient from the aspect of maintaining the active end of the conjugated diene polymer in the reaction system, and it is not easy to fully maintain the activity of the polymerization active end. In addition, when the addition amount of such a polar compound is used, the randomization ability for vinyl aromatic compounds and conjugated diene compounds is not high enough, and in the conjugated diene polymer of the present embodiment where the bonding vinyl aromatic monomer unit amount and the vinyl bonding amount are in the above-mentioned specific range, there is a tendency that the polymerization end becomes a vinyl aromatic monomer unit. In such a state, there is a tendency to be difficult to obtain a conjugated diene polymer with a high coupling rate or a modification rate.

[0373] That is, in the method for producing a conjugated diene polymer of the present embodiment, since a branching agent is used, even when a polar compound is added in an amount that generally does not sufficiently maintain the activity of the polymerization active terminal, the active terminal of the polymer can be sufficiently maintained, and a high coupling rate and modification rate can be achieved.

[0374] The timing of adding the branching agent in the branching step is not particularly limited and can be appropriately selected depending on the application of the conjugated diene polymer to be produced.

[0375] From the perspective of increasing the absolute molecular weight of the obtained conjugated diene polymer and increasing the modification rate in the coupling process, the timing of adding the branching agent is preferably when the raw material conversion rate is 20% or more after the addition of the polymerization initiator, and the conversion rate is more preferably 40% or more, further preferably 50% or more, further more preferably 65% ​​or more, and further preferably 75% or more. That is, the timing of adding the branching agent is preferably when the polymerization reaction is sufficiently stable. By making the timing of adding the branching agent within the above range, even if the amount of polar compound added is small or not added, a conjugated diene polymer with a higher modification rate can be obtained in the coupling process.

[0376] The branching agent is not particularly limited, and for example, a compound represented by the following formula (10) or formula (11) can be used.

[0377] [Chemistry 22]

[0378]

[0379] [Chemistry 23]

[0380]

[0381] (In formula (10), R 1 The group represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and a part of the group may have a branched structure.

[0382] R 2 ~R 3 Each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and a part of them may have a branched structure.

[0383] When there are multiple R 1 ~R 3 Each one is independent.

[0384] X 1 represents an independent halogen atom.

[0385] m represents an integer of 0 to 2, n represents an integer of 0 to 3, and l represents an integer of 0 to 3.

[0386] (m+n+1) means 3.)

[0387] (In formula (11), R 4 ~R 7 Each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and a part of them may have a branched structure.

[0388] When there are multiple R 4 ~R 7 Each one is independent.

[0389] X 2 ~X 3 represents an independent halogen atom.

[0390] m represents an integer of 0 to 2, n represents an integer of 0 to 3, and l represents an integer of 0 to 3.

[0391] (m+n+l) means 3.

[0392] a represents an integer from 0 to 3, b represents an integer from 0 to 2, and c represents an integer from 0 to 3. (a+b+c) represents 3.)

[0393] In this embodiment, from the perspective of polymerization sustainability and increasing the degree of branching, the branching agent used to construct the main chain branch structure of the conjugated diene polymer is preferably R of the above formula (10): 1 A compound in which m is a hydrogen atom and m=0.

[0394] In the present embodiment, the branching agent used to construct the main chain branch structure of the conjugated diene polymer is preferably a compound wherein m=0 and b=0 in the above formula (11) from the viewpoint of increasing the degree of branching.

[0395] In addition, in this embodiment, from the perspective of polymerization sustainability, improvement of the modification rate and the degree of branching, the branching agent used when constructing the main chain branch structure of the conjugated diene polymer is more preferably R of the above formula (10): 1 A compound in which m=0 and l=0 is a hydrogen atom.

[0396] In this embodiment, the branching agent used to construct the main chain branch structure of the conjugated diene polymer is more preferably a compound with m=0, l=0, a=0, b=0 in the above formula (11) from the viewpoint of increasing the modification rate and the branching degree.

[0397] In addition, in this embodiment, from the perspective of polymerization sustainability, improvement of the modification rate and the degree of branching, the branching agent used when constructing the main chain branch structure of the conjugated diene polymer is more preferably R in the above formula (10): 1 A compound wherein l is a hydrogen atom, l=0, and n=3.

[0398] Examples of the branching agent represented by the formula (10) include, but are not limited to, trimethoxy(4-vinylphenyl)silane, triethoxy(4-vinylphenyl)silane, tripropoxy(4-vinylphenyl)silane, tributoxy(4-vinylphenyl)silane, triisopropoxy(4-vinylphenyl)silane, trimethoxy(3-vinylphenyl)silane, triethoxy(3-vinylphenyl)silane, tripropoxy(3-vinylphenyl)silane, tributoxy(3-vinylphenyl)silane, triisopropoxy(3-vinylphenyl)silane, trimethoxy(2-vinylphenyl)silane, silane, triethoxy(2-vinylphenyl)silane, tripropoxy(2-vinylphenyl)silane, tributoxy(2-vinylphenyl)silane, triisopropoxy(2-vinylphenyl)silane, dimethoxymethyl(4-vinylphenyl)silane, diethoxymethyl(4-vinylphenyl)silane, dipropoxymethyl(4-vinylphenyl)silane, dibutoxymethyl(4-vinylphenyl)silane, diisopropoxymethyl(4-vinylphenyl)silane, dimethoxymethyl(3-vinylphenyl)silane, diethoxymethyl(3-vinylphenyl)silane, dipropoxymethyl(3-vinylphenyl)silane silane, dibutyloxymethyl (3-vinylphenyl) silane, diisopropyloxymethyl (3-vinylphenyl) silane, dimethoxymethyl (2-vinylphenyl) silane, diethoxymethyl (2-vinylphenyl) silane, dipropoxymethyl (2-vinylphenyl) silane, dibutyloxymethyl (2-vinylphenyl) silane, diisopropyloxymethyl (2-vinylphenyl) silane, dimethylmethoxy (4-vinylphenyl) silane, dimethylethoxy (4-vinylphenyl) silane, dimethylpropoxy (4-vinylphenyl) silane, dimethylbutyloxy (4-vinylphenyl) ) silane, dimethylisopropoxy(4-vinylphenyl)silane, dimethylmethoxy(3-vinylphenyl)silane, dimethylethoxy(3-vinylphenyl)silane, dimethylpropoxy(3-vinylphenyl)silane, dimethylbutoxy(3-vinylphenyl)silane, dimethylisopropoxy(3-vinylphenyl)silane, dimethylmethoxy(2-vinylphenyl)silane, dimethylethoxy(2-vinylphenyl)silane, dimethylpropoxy(2-vinylphenyl)silane, dimethylbutoxy(2-vinylphenyl)silane, dimethylisopropoxy(2-vinylphenyl)silane.

[0399] Examples of the branching agent represented by the formula (10) include trimethoxy(4-isopropenylphenyl)silane, triethoxy(4-isopropenylphenyl)silane, tripropoxy(4-isopropenylphenyl)silane, tributoxy(4-isopropenylphenyl)silane, triisopropoxy(4-isopropenylphenyl)silane, trimethoxy(3-isopropenylphenyl)silane, triethoxy(3-isopropenylphenyl)silane, tripropoxy(3-isopropenylphenyl)silane, tributoxy(3-isopropenylphenyl)silane, triisopropoxy(3-isopropenylphenyl)silane, trimethoxy(2-isopropenylphenyl)silane, triethoxy(2-isopropenylphenyl)silane, tripropoxy(2-isopropenylphenyl)silane, Tributoxy(2-isopropenylphenyl)silane, triisopropoxy(2-isopropenylphenyl)silane, dimethoxymethyl(4-isopropenylphenyl)silane, diethoxymethyl(4-isopropenylphenyl)silane, dipropoxymethyl(4-isopropenylphenyl)silane, dibutoxymethyl(4-isopropenylphenyl)silane, diisopropoxymethyl(4-isopropenylphenyl)silane, dimethoxymethyl(3-isopropenylphenyl)silane, diethoxymethyl(3-isopropenylphenyl)silane, dipropoxymethyl(3-isopropenylphenyl)silane, dibutoxymethyl(3-isopropenylphenyl)silane, diisopropoxymethyl(3-isopropenylphenyl)silane, dimethoxymethyl(2-isopropenylphenyl)silane, diethoxymethyl(4-isopropenylphenyl)silane, dipropoxymethyl(4-isopropenylphenyl)silane, Oxymethyl (2-isopropenylphenyl) silane, dipropoxymethyl (2-isopropenylphenyl) silane, dibutoxymethyl (2-isopropenylphenyl) silane, diisopropoxymethyl (2-isopropenylphenyl) silane, dimethylmethoxy (4-isopropenylphenyl) silane, dimethylethoxy (4-isopropenylphenyl) silane, dimethylpropoxy (4-isopropenylphenyl) silane, dimethylbutoxy (4-isopropenylphenyl) silane, dimethylisopropoxy (4-isopropenylphenyl) silane, dimethylmethoxy (3-isopropenylphenyl) silane, dimethylethoxy (3-isopropenylphenyl) silane, dimethylpropoxy (3-isopropenylphenyl) silane, dimethylbutoxy (3-isopropenylphenyl) silane, dimethylisopropoxy(3-isopropenylphenyl)silane, dimethylmethoxy(2-isopropenylphenyl)silane, dimethylethoxy(2-isopropenylphenyl)silane, dimethylpropoxy(2-isopropenylphenyl)silane, dimethylbutoxy(2-isopropenylphenyl)silane, dimethylisopropoxy(2-isopropenylphenyl)silane, trichloro(4-vinylphenyl)silane, trichloro(3-vinylphenyl)silane, trichloro(2-vinylphenyl)silane, tribromo(4-vinylphenyl)silane, tribromo(3-vinylphenyl)silane, tribromo(2-vinylphenyl)silane, dichloromethyl(4-vinylphenyl)silane, dichloromethyl(3-vinylphenyl)silane, dichloromethyl(2-vinylphenyl)silane,Dibromomethyl (4-vinylphenyl) silane, dibromomethyl (3-vinylphenyl) silane, dibromomethyl (2-vinylphenyl) silane, dimethylchloro (4-vinylphenyl) silane, dimethylchloro (3-vinylphenyl) silane, dimethylchloro (2-vinylphenyl) silane, dimethylbromo (4-vinylphenyl) silane, dimethylbromo (3-vinylphenyl) silane, dimethylbromo (2-vinylphenyl) silane.

[0400] Among these, trimethoxy(4-vinylphenyl)silane, triethoxy(4-vinylphenyl)silane, tripropoxy(4-vinylphenyl)silane, tributoxy(4-vinylphenyl)silane, triisopropoxy(4-vinylphenyl)silane, trimethoxy(3-vinylphenyl)silane, triethoxy(3-vinylphenyl)silane, tripropoxy(3-vinylphenyl)silane, tributoxy(3-vinylphenyl)silane, triisopropoxy(3-vinylphenyl)silane, and trichloro(4-vinylphenyl)silane are preferred, and trimethoxy(4-vinylphenyl)silane, triethoxy(4-vinylphenyl)silane, tripropoxy(4-vinylphenyl)silane, tributoxy(4-vinylphenyl)silane, and triisopropoxy(4-vinylphenyl)silane are more preferred.

[0401] Examples of the branching agent represented by the formula (11) include, but are not limited to, 1,1-bis(4-trimethoxysilylphenyl)ethylene, 1,1-bis(4-triethoxysilylphenyl)ethylene, 1,1-bis(4-tripropoxysilylphenyl)ethylene, 1,1-bis(4-tripentoxysilylphenyl)ethylene, 1,1-bis(4-triisopropoxysilylphenyl)ethylene, 1,1-bis(3-trimethoxysilylphenyl)ethylene, 1,1-bis(3-triethoxysilylphenyl)ethylene, 1,1-bis(3-tripropoxysilylphenyl)ethylene, 1,1-bis(3-tripentoxysilylphenyl)ethylene, 1,1-bis(3-triisopropoxysilylphenyl)ethylene, 1,1-bis(2- 1,1-bis(4-(dimethylmethoxysilyl)phenyl)ethylene, 1,1-bis(4-(diethylmethoxysilyl)phenyl)ethylene, 1,1-bis(4-(dipropylmethoxysilyl)phenyl)ethylene, 1,1-bis(4-(dimethylethoxysilyl)phenyl)ethylene, 1,1-bis(4-(diethylethoxysilyl)phenyl)ethylene, 1,1-bis(4-(dipropylethoxysilyl)phenyl)ethylene.

[0402] Among these, 1,1-bis(4-trimethoxysilylphenyl)ethylene, 1,1-bis(4-triethoxysilylphenyl)ethylene, 1,1-bis(4-tripropoxysilylphenyl)ethylene, 1,1-bis(4-tripentoxysilylphenyl)ethylene, and 1,1-bis(4-triisopropoxysilylphenyl)ethylene are preferred, and 1,1-bis(4-trimethoxysilylphenyl)ethylene is more preferred.

[0403] The amount of such a branching agent added is not particularly limited and can be appropriately selected according to the intended use of the conjugated diene polymer, and is preferably 0.020 mol to 0.50 mol, more preferably 0.025 mol to 0.40 mol, and further preferably 0.030 mol to 0.25 mol, relative to 1 mol of the polymerization initiator.

[0404] The amount of the branching agent added within the above range may be 0.040 mol or more or 0.045 mol or more per mol of the polymerization initiator, or may be 0.20 mol or less or 0.18 mol or less per mol of the polymerization initiator.

[0405] The amount of the branching agent added may be within the range of any combination of the upper and lower limits. The amount of the branching agent added affects the overall branching degree of the conjugated diene polymer. If the amount of the branching agent added increases, the overall branching degree and the branching degree at the extreme value increase.

[0406] In the polymerization branching step, the reaction temperature may or may not be changed after the addition of the branching agent.

[0407] In the polymerization branching step, after adding the branching agent, a monomer as a raw material of the conjugated diene polymer may be further added, and thereafter, a branching agent may be further added, or the additional addition of the branching agent and the monomer may be repeated.

[0408] The monomer to be added is not particularly limited, but it is preferred to add the same monomer as that initially added as a monomer in the polymerization branching step in order to increase the modification rate in the coupling step.

[0409] The amount of the additional monomer may be 1.0% or more, 5.0% or more, 10% or more, 15% or more, or 20% or more of the total amount of the monomers used as the conjugated diene polymer. In addition, the amount of the additional monomer may be 50% or less, 40% or less, or 35% or less.

[0410] When the amount of the additional monomer is within the above range, the molecular weight between the branch point generated by the addition of the branching agent and the branch point generated by the addition of the coupling modifier becomes longer, so there is a tendency to easily obtain a linear polymer structure. By making the obtained conjugated diene polymer have such a structure, the entanglement between the molecular chains of the conjugated diene polymer increases after the sulfide is prepared, and there is a tendency to easily obtain a sulfide excellent in wear resistance, handling stability and breaking strength.

[0411] (Coupling process)

[0412] In the manufacture method of the conjugated diene polymer of the present embodiment, it is preferred that the conjugated diene polymer with branched structure obtained by the above-mentioned polymerization branching process is reacted with a coupling modifier to form a modified conjugated diene polymer. Through such a coupling process, the conjugated diene polymer with branched structure obtained by the polymerization branching process can be modified by a functional group containing nitrogen atoms having affinity or bonding reactivity with a filler. In addition, a plurality of conjugated diene polymers can be coupled. Therefore, by utilizing the manufacture method with such a coupling process, the conjugated diene polymer of the present embodiment that exerts the above-mentioned effect can be obtained more surely and simply.

[0413] The coupling modifier is not particularly limited as long as it is a reactive compound having a nitrogen atom-containing functional group having affinity or bonding reactivity with the filler and having two or more functional groups that can react with the active terminal of the conjugated diene polymer.

[0414] Examples of such a coupling modifier include a coupling modifier containing a nitrogen atom and further having a group containing a nitrogen atom and a silicon atom.

[0415] Examples of coupling modifiers having a group containing a nitrogen atom include, but are not limited to, isocyanate compounds, isothiocyanate compounds, isocyanuric acid derivatives, carbonyl compounds containing a nitrogen atom, vinyl compounds containing a nitrogen atom, epoxy compounds containing a nitrogen atom, imine compounds, and alkoxysilane compounds containing a nitrogen atom.

[0416] Preferred coupling modifiers having a group containing a nitrogen atom include, for example, amine compounds having no active hydrogen, protected amine compounds in which active hydrogen is substituted with a protecting group, imine compounds having a structure of the general formula -N=C, and alkoxysilane compounds bonded to these nitrogen atom-containing compounds. Examples of amine compounds having no active hydrogen include tertiary amine compounds.

[0417] Examples of the isocyanate compound include, but are not limited to, 2,4-benzylene diisocyanate, 2,6-benzylene diisocyanate, diphenylmethane diisocyanate, polymeric diphenylmethane diisocyanate (C-MDI), phenyl isocyanate, isophorone diisocyanate, hexamethylene diisocyanate, butyl isocyanate, and 1,3,5-benzene triisocyanate.

[0418] Examples of the isothiocyanate compound include, but are not limited to, 2,4-benzylene diisothiocyanate, 2,6-benzylene diisothiocyanate, diphenylmethane diisothiocyanate, phenyl isothiocyanate, isophorone diisothiocyanate, hexamethylene diisothiocyanate, butyl isothiocyanate, and 1,3,5-benzene triisothiocyanate.

[0419] Examples of the isocyanuric acid derivatives include, but are not limited to, 1,3,5-tris(3-trimethoxysilylpropyl)isocyanurate, 1,3,5-tris(3-triethoxysilylpropyl)isocyanurate, 1,3,5-tris(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.

[0420] Examples of the carbonyl compound 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-pyrrolidone, N-methyl-2-piperidone, N-methyl-2-quinolone, 4,4'-bis(diethylamino)benzophenone, 4,4'-bis(dimethylamino)benzophenone, methyl -2-pyridyl ketone, methyl-4-pyridyl ketone, propyl-2-pyridyl ketone, di-4-pyridyl ketone, 2-benzoylpyridine, N,N,N',N'-tetramethylurea, N,N-dimethyl-N',N'-diphenylurea, methyl N,N-diethylcarbamate, N,N-diethylacetamide, N,N-dimethyl-N',N'-dimethylaminoacetamide, N,N-dimethylpicolinamide and N,N-dimethylisonicotinamide.

[0421] Examples of the vinyl compound containing a nitrogen atom include, but are not limited to, N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, N-methylmaleimide, N-methylphthalimide, N,N-bistrimethylsilylacrylamide, morpholinoacrylamide, 3-(2-dimethylaminoethyl)styrene, (dimethylamino)dimethyl-4-vinylphenylsilane, 4,4'-vinylidenebis(N,N-dimethylaniline), 4,4'-vinylidenebis(N,N-diethylaniline), 1,1-bis(4-morpholinophenyl)ethylene, and 1-phenyl-1-(4-N,N-dimethylaminophenyl)ethylene.

[0422] Examples of the epoxy compound containing a nitrogen atom include, but are not limited to, hydrocarbon compounds containing an epoxy group bonded to an amino group.

[0423] The hydrocarbon compound containing an epoxy group bonded to an amino group may further have an epoxy group bonded to an ether group. Examples of such nitrogen atom-containing epoxy compounds include, but are not limited to, compounds represented by the following formula (12).

[0424] [Chemistry 24]

[0425]

[0426] In the above formula (12), R is a hydrocarbon group having a valency of 2 or more, or a divalent organic group having at least one polar group selected from polar groups having oxygen such as ether, epoxy, ketone, polar groups having sulfur such as thioether, thioketone, and polar groups having nitrogen such as tertiary amino, imino, etc.

[0427] The hydrocarbon group with a valency of 2 or more is saturated or unsaturated and may be a straight chain, branched chain or cyclic hydrocarbon group, including alkylene, alkenylene, phenylene, etc. Preferably, it is a hydrocarbon group having 1 to 20 carbon atoms. For example, methylene, ethylene, butylene, cyclohexylene, 1,3-bis(methylene)-cyclohexane, 1,3-bis(ethylene)-cyclohexane, o-phenylene, m-phenylene, p-phenylene, m-xylene, p-xylene, bis(phenylene)-methane, etc. can be mentioned.

[0428] In the above formula (12), R 24 , R 27 is a hydrocarbon group having 1 to 10 carbon atoms, R 24 , R 27 They can be the same as or different from each other.

[0429] In the above formula (12), R 25 , R 28 is hydrogen or a hydrocarbon group having 1 to 10 carbon atoms, R 25 , R 28They can be the same as or different from each other.

[0430] In the above formula (12), R 26 It is a hydrocarbon group having 1 to 10 carbon atoms, or a structure of the following formula (13).

[0431] R 24 , R 25 , R 26 It may be a ring structure formed by mutual bonding.

[0432] In addition, in R 26 In the case of a hydrocarbon group, it may be a cyclic structure formed by bonding with R. In the case of the above cyclic structure, it may be a cyclic structure bonded to R 26 The N on the molecule is directly bonded to the R.

[0433] In the above formula (12), f is an integer greater than or equal to 1, and g is an integer greater than or equal to 0.

[0434] [Chemistry 25]

[0435]

[0436] In the above formula (13), R 29 , R 30 R of the above formula (12) 24 , R 25 Similarly, R 29 , R 30 They can be the same as or different from each other.

[0437] The nitrogen atom-containing epoxy compound is preferably a nitrogen atom-containing epoxy compound having one or more diglycidylamino groups and one or more glycidyloxy groups in the molecule.

[0438] Examples of the epoxy compound containing a nitrogen atom include, but are not limited to, N,N-diglycidyl-4-glycidyloxyaniline, 1-N,N-diglycidylaminomethyl-4-glycidyloxy-cyclohexane, 4-(4-glycidyloxyphenyl)-(N,N-diglycidyl)aniline, 4-(4-glycidyloxyphenoxy)-(N,N-diglycidyl)aniline, 4-(4-glycidyloxybenzyl)-(N,N-diglycidyl)aniline, 4-(N,N'-diglycidyl-2-piperazinyl)-glycidyloxybenzene, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-m-dimethyl Phenylenediamine, 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, N,N-diglycidyl-o-toluidine and N,N-diglycidylaminomethylcyclohexane.

[0439] Preferred examples of these include N,N-diglycidyl-4-glycidoxyaniline and 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane.

[0440] As for the imine compound as a coupling modifier having a group containing a nitrogen atom, for example, but not limited to, N-butylpropane-2-imine, N-butyl-4-methylpentane-2-imine, N,N'-(propane-1,3-diyl)bis(4-methylpentane-2-imine), N,N'-(hexane-1,6-diyl)bis(4-methylpentane-2-imine), tris[2-(propane-2-imine)] [2-(amino)ethyl]amine, tris[2-(propane-2-ylideneamino)propyl]amine, N,N'-(1,4-phenylene)bis(4-methylpentane-2-imine), 1,1'-(1,4-phenylene)bis(N-propylethane-1-imine), N,N'-(propane-1,3-diyl)bis(1-phenylmethanimine), N,N'-(hexane-1,6-diyl)bis(1-phenylmethanimine).

[0441] The alkoxysilane compound containing a nitrogen atom as a coupling modifier having a group containing a nitrogen atom may be, for example, but not limited to, 3-dimethylaminopropyltrimethoxysilane, 3-dimethylaminopropylmethyldimethoxysilane, 3-diethylaminopropyltriethoxysilane, 3-morpholinopropyltrimethoxysilane, 3-piperidinylpropyltriethoxysilane, 3-hexamethyleneiminopropylmethyldiethoxysilane, 3-(4-methyl-1-piperazinyl)propyltriethoxysilane, 3-(4-methyl-1-piperazinyl)propyltrimethoxysilane, 1-[3-(triethoxymethylsilane)]-1-yl ... alkyl)-propyl]-3-methylhexahydropyrimidine, 3-(4-trimethylsilyl-1-piperazinyl)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'-tetrakis(3-trimethoxysilylpropyl)ethylenediamine, 3-isocyanatopropyltrimethoxysilane, 3-cyanopropyltrimethoxysilane, 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-silacyclohexane , 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-silacyclooctane and 2,2-dimethoxy-8-(N,N-diethylamino)methyl-1,6-dioxa-2-silacyclooctane.

[0442] Preferred examples of the alkoxysilane compound containing a nitrogen atom include, but are not limited to, 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, tetrakis(3-trimethoxysilylpropyl)-1,3-propylenediamine (also referred to as "N,N,N',N'-tetrakis(3-trimethoxysilylpropyl)-1,3-propylenediamine"), tris(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]amine, 1,3-propanediamine, tris(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-methyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, bis(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-sila-2-cyclopentane)propyl]-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-bisaminomethylcyclohexane, tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-sila-2-cyclopentane)propyl]-1,3-bisaminomethyl Cyclohexane, tetrakis(3-trimethoxysilylpropyl)-1,6-hexanediamine, penta(3-trimethoxysilylpropyl)-diethylenetriamine, tris(3-trimethoxysilylpropyl)-methyl-1,3-propanediamine, tetrakis[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-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]silane, 3-tris[2-(2,2-dimethoxy-1-aza-2-silacyclopentane)ethoxy]silyl-1-trimethoxysilylpropane, 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-trimethoxysilylpropyl)-cyclohexane, 3,4,5-tris(3-trimethoxysilylpropyl)-cyclohexyl-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)ethoxy]silyl-1-trimethoxysilylpropane2-Dimethoxy-1-aza-2-silacyclopentane)propyl] ether, (3-trimethoxysilylpropyl) phosphate, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl] phosphate, 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-dimethylbutylene)-3-(triethoxysilyl)-1-propylamine, N-(1,3-dimethylbutylene) 1-propylamine, N-benzylidene-3-(triethoxysilyl)propane-1-amine, N-benzylidene-3-(trimethoxysilyl)propane-1-amine, 1,1-(1,4-phenylene)bis(N-(3(triethoxysilyl)propyl)methylamine), 1,1-(1,4-phenylene)bis(N-(3(trimethoxysilyl)propyl)methylamine), 2-methoxy-2-methyl-1-(benzylideneaminoethyl)-1-aza-2-silacyclopentane, and 2-methoxy-2-methyl-1-(4-methoxybenzylideneaminoethyl)-1-aza-2-silacyclopentane.

[0443] In the coupling modifier having a group containing a nitrogen atom, as a protected amine compound in which active hydrogen is replaced by a protecting group, a compound having an unsaturated bond and a protected amine in the molecule can be cited. Such a compound can be cited, but is not limited to, for example, 4,4'-vinylidenebis[N,N-bis(trimethylsilyl)aniline], 4,4'-vinylidenebis[N,N-bis(triethylsilyl)aniline], 4,4'-vinylidenebis[N,N-bis(tert-butyldimethylsilyl)aniline], 4,4'-vinylidenebis[N-methyl-N-(trimethylsilyl)aniline], 4,4'-vinylidenebis[N-ethyl-N-(trimethylsilyl)aniline], 4,4'-vinylidenebis[N-methyl-N-(triethylsilyl)aniline] amine], 4,4'-vinylidenebis[N-ethyl-N-(triethylsilyl)aniline], 4,4'-vinylidenebis[N-methyl-N-(tert-butyldimethylsilyl)aniline], 4,4'-vinylidenebis[N-ethyl-N-(tert-butyldimethylsilyl)aniline], 1-[4-N,N-bis(trimethylsilyl)aminophenyl]-1-[4-N-methyl-N-(trimethylsilyl)aminophenyl]ethylene, and 1-[4-N,N-bis(trimethylsilyl)aminophenyl]-1-[4-N,N-dimethylaminophenyl]ethylene.

[0444] Among the coupling modifiers having a nitrogen atom-containing group, examples of the protected amine compound in which active hydrogen is substituted with a protecting group include compounds having an alkoxysilane and a protected amine in the molecule.

[0445] 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(trimethylsilyl)aminopropyltriethoxysilane, N,N-bis(trimethylsilyl)aminopropylmethyldiethoxysilane, methyldiethoxysilane, 3-(4-trimethylsilyl-1-piperazinyl)propyltriethoxysilane, 3-(3-triethylsilyl-1-imidazolidinyl)propylmethyldiethoxysilane, 3-(3-trimethylsilyl-1-hexahydropyrimidinyl)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-trimethoxysilyl-1-piperazinyl)propyltriethoxysilane, 3-(3-triethylsilyl-1-imidazolidinyl)propylmethyldiethoxysilane, 3-(3-trimethylsilyl-1-hexahydropyrimidinyl)propyltrimethoxysilane, 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, N-(1,3-dimethylbutylene)-3-methyl(dimethoxysilyl)-1-propylamine, N-(1,3-dimethylbutylene)-3-methyl(dimethoxysilyl)-1-propylamine )-3-methyl(diethoxysilyl)-1-propylamine, N-(1-methylethylidene)-3-(triethoxysilyl)-1-propylamine, N-(1-methylethylidene)-3-(trimethoxysilyl)-1-propylamine, N-(1-methylethylidene)-3-methyl(dimethoxysilyl)-1-propylamine, N-(1-methylethylidene)-3-methyl(diethoxysilyl)-1-propylamine, N-ethylidene-3-(triethoxysilyl)-1-propylamine, N-ethylidene-3-(trimethoxysilyl)-1-propylamine.

[0446] Other examples include N-ethylidene-3-methyl(dimethoxysilyl)-1-propylamine, N-ethylidene-3-methyl(diethoxysilyl)-1-propylamine, N-(1-methylpropylene)-3-(triethoxysilyl)-1-propylamine, N-(1-methylpropylene)-3-(trimethoxysilyl)-1-propylamine, N-(1-methylpropylene)-3-methyl(dimethoxysilyl)-1-propylamine, Propylamine, N-(1-methylpropylidene)-3-methyl(diethoxysilyl)-1-propylamine, N-benzylidene-3-methyl(dimethoxysilyl)propane-1-amine, N-benzylidene-3-methyl(diethoxysilyl)propane-1-amine, N-4-methylbenzylidene-3-(triethoxysilyl)propane-1-amine, N-4-methylbenzylidene-3-(trimethoxysilyl)propane-1-amine 、N-4-methylbenzylidene-3-methyl(dimethoxysilyl)propane-1-amine、N-4-methylbenzylidene-3-methyl(diethoxysilyl)propane-1-amine、N-naphthylene-3-(triethoxysilyl)propane-1-amine、N-naphthylene-3-(trimethoxysilyl)propane-1-amine、N-naphthylene-3-methyl(dimethoxysilyl)propane-1-amine、1,1-(1 ,4-phenylene)bis(N-(3-methyl(dimethoxysilyl)propyl)methylamine), 1,1-(1,4-phenylene)bis(N-(3-methyl(diethoxysilyl)propyl)methylamine), 2-ethoxy-2-methyl-1-(benzylideneaminoethyl)-1-aza-2-silacyclopentane, and 2-methoxy-2-methyl-1-(methylisobutylideneaminoethyl)-1-aza-2-silacyclopentane.

[0447] In the coupling step, it is more preferred to use two or more nitrogen-containing alkoxysilane compounds represented by any one of the following formulae (14) to (18) in combination as the coupling modifier.

[0448] As the coupling modifier, a coupling modifier having two or less alkoxysilyl groups and a coupling modifier having more than two alkoxysilyl groups may be used in combination.

[0449] [Chemistry 26]

[0450]

[0451] In formula (14), R 8 ~R 10 is a hydrocarbon group having 1 to 20 carbon atoms, may have an unsaturated bond, and may be the same or different. 11 , R 12 is an aliphatic hydrocarbon group having 1 to 6 carbon atoms, which may have an unsaturated bond and may be the same or different.13 It is a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with an organic group containing Si, O or N and having no active hydrogen, and may have an unsaturated bond. d is an integer of 1 to 3.

[0452] [Chemistry 27]

[0453]

[0454] In formula (15), R 14 ~R 16 It is a hydrocarbon group having 1 to 20 carbon atoms, may have an unsaturated bond, and may be the same or different.

[0455] R 17 , R 18 It is a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with an organic group containing Si, O or N and having no active hydrogen, and may have an unsaturated bond. e is an integer of 1 to 3.

[0456] [Chemistry 28]

[0457]

[0458] In formula (16), R 31 ~R 34 Each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and R 35 represents an alkylene group having 1 to 10 carbon atoms, R 36 It represents an alkylene group having 1 to 20 carbon atoms.

[0459] h represents an integer of 1 to 3, i represents an integer of 1 or 2, and (h+i) represents an integer of 4 or more. 31 ~R 34 Each one is independent.

[0460] [Chemistry 29]

[0461]

[0462] In formula (17), R 37 ~R 42 Each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and R 43 ~R 45 Each independently represents an alkylene group having 1 to 20 carbon atoms.

[0463] m, n and l each independently represent an integer of 1 to 3, and (m+n+l) represents an integer of 4 or greater. 37 ~R 42 Each one is independent.

[0464] [Chemistry 30]

[0465]

[0466] In formula (18), R 46 ~R 48 Each independently represents a single bond or an alkylene group having 1 to 20 carbon atoms, and R 49 ~R 52 Each independently represents an alkyl group having 1 to 20 carbon atoms, R 53 and R 56 Each independently represents an alkylene group having 1 to 20 carbon atoms, and R 54 represents an alkylene group or an alkoxy group having 1 to 20 carbon atoms, R 55 It represents an alkyl group having 1 to 20 carbon atoms or a trialkylsilyl group.

[0467] o represents an integer of 1 to 3, and p represents 1 or 2.

[0468] When there are multiple R 46 ~R 56 , o and p are independent of each other and can be the same or different.

[0469] q represents an integer of 0-6, r represents an integer of 0-6, s represents an integer of 0-6, and (q+r+s) is an integer of 4-10.

[0470] A represents a hydrocarbon group having 1 to 20 carbon atoms; or an organic group having at least one atom selected from the group consisting of an oxygen atom, a nitrogen atom, a silicon atom, a sulfur atom and a phosphorus atom and having no active hydrogen.

[0471] Examples of the coupling modifier represented by the formula (14) include, but are not limited to, 1-methyl-4-(3-(trimethoxysilyl)propyl)piperazine, 1-methyl-4-(3-(triethoxysilyl)propyl)piperazine, 1-ethyl-4-(3-(trimethoxysilyl)propyl)piperazine, 1-ethyl-4-(3-(triethoxysilyl)propyl)piperazine, 1-propyl-4-(3-(trimethoxysilyl)propyl)piperazine, 1-propyl-4-(3-(triethoxysilyl)propyl)piperazine, 1-butyl-4-(3-(trimethoxysilyl)propyl)piperazine, 1-butyl-4-(3-(triethoxysilyl)propyl)piperazine, 1-trimethylsilyl-4-(3-(trimethoxysilyl)propyl)piperazine, 1-butyl-4-(3-(triethoxysilyl)propyl)piperazine, 1-ethyl-4-(3-(trimethoxysilyl)propyl)piperazine, 1-propyl-4-(3-(trimethoxysilyl)propyl)piperazine, 1-propyl-4-(3-(triethoxysilyl)propyl)piperazine, 1-butyl-4-(3-(trimethoxysilyl)propyl)piperazine, 1-butyl ... -(3-(trimethoxysilyl)propyl)piperazine, 1-trimethylsilyl-4-(3-(triethoxysilyl)propyl)piperazine, 1-triethylsilyl-4-(3-(trimethoxysilyl)propyl)piperazine, 1-triethylsilyl-4-(3-(trimethoxysilyl)propyl)piperazine, 1-triethylsilyl-4-(3-(triethoxysilyl)propyl)piperazine, 1-(tert-butyldimethylsilyl)-4-(3-(trimethoxysilyl)propyl)piperazine, 1-(tert-butyldimethylsilyl)-4-(3-(triethoxysilyl)propyl)piperazine, 1-triisopropylsilyl-4-(3-(trimethoxysilyl)propyl)piperazine, 1-triisopropylsilyl-4-(3-(triethoxysilyl)propyl)piperazine, and the like.

[0472] Among these, from the perspective of improving the reactivity and interaction between the conjugated diene polymer and the inorganic filler such as silica, and improving the processability, in the above formula (14), d is preferably 3. Specifically, 1-methyl-4-(3-(trimethoxysilyl)propyl)piperazine and 1-methyl-4-(3-(triethoxysilyl)propyl)piperazine are preferred.

[0473] The reaction temperature and reaction time when reacting the coupling modifier having a nitrogen atom-containing group represented by the formula (14) with the polymerization active terminal are not particularly limited, but the reaction is preferably carried out at 0° C. to 120° C. for 30 seconds or more.

[0474] The amount of the coupling modifier represented by the above formula (14) to be added is preferably equal to the amount of the alkoxy group (OR 8) is in the range of 0.2 to 2.5 times the added molar number of the polymerization initiator, more preferably in the range of 0.5 to 2.0 times, and further preferably in the range of 1.0 to 2.0 times. From the aspect of making the modification rate and molecular weight of the obtained conjugated diene polymer in a more preferred range, it is preferably 0.2 times or more. In addition, from the aspect of suppressing the reduction of processability due to excessive increase of branching degree, it is preferably 2.5 times or less.

[0475] More specifically, the amounts of the polymerization initiator and the coupling modifier represented by the above formula (14) added may be adjusted so that the molar number of the polymerization initiator is preferably 1.5 times or more, more preferably 1.7 times or more, the molar number of the coupling modifier represented by the above formula (14).

[0476] Examples of the coupling modifier represented by the formula (15) include, but are not limited to, N-(1,3-dimethylbutylene)-3-(triethoxysilyl)-1-propylamine, N-(1,3-dimethylbutylene)-3-(trimethoxysilyl)-1-propylamine, N-(1,3-dimethylbutylene)-3-methyl(dimethoxysilyl)-1-propylamine, N-(1,3-dimethylbutylene)-3-methyl(diethoxysilyl)-1-propylamine, N-(1-methylethylidene)-3-(triethoxysilyl)-1-propylamine, N-(1-methylethylidene)-3-(trimethoxysilyl)-1-propylamine, N-(1-methylethylidene)-3-(trimethoxysilyl)-1-propylamine, 1-propylamine, N-(1-methylethylidene)-3-methyl(diethoxysilyl)-1-propylamine, N-ethylidene-3-(triethoxysilyl)-1-propylamine, N-ethylidene-3-(trimethoxysilyl)-1-propylamine, N-ethylidene-3-methyl(dimethoxysilyl)-1-propylamine, N-ethylidene-3-methyl(diethoxysilyl)-1-propylamine, N-(1-methylpropylene)-3-(triethoxysilyl)-1-propylamine, N-(1-methylpropylene)-3-(trimethoxysilyl)-1-propylamine, N-(1-methylpropylene)-3-methyl (Dimethoxysilyl)-1-propylamine, N-(1-methylpropylidene)-3-methyl(diethoxysilyl)-1-propylamine, N-benzylidene-3-(triethoxysilyl)propane-1-amine, N-benzylidene-3-(trimethoxysilyl)propane-1-amine, N-benzylidene-3-methyl(dimethoxysilyl)propane-1-amine, N-benzylidene-3-methyl(diethoxysilyl)propane-1-amine, N-4-methylbenzylidene-3-methyl(dimethoxysilyl)propane-1-amine, N-4-methylbenzylidene-3-methyl(triethoxysilyl)propane-1-amine, )propane-1-amine, N-4-methylbenzylidene-3-methyl(diethoxysilyl)propane-1-amine, N-naphthylene-3-(triethoxysilyl)propane-1-amine, N-naphthylene-3-(trimethoxysilyl)propane-1-amine, N-naphthylene-3-methyl(dimethoxysilyl)propane-1-amine, 1,1-(1,4-phenylene)bis(N-(3(triethoxysilyl)propyl)methylamine), 1,1-(1,4-phenylene)bis(N-(3(trimethoxysilyl)propyl)methylamine), 1,1-(1,4-phenylene)bis(N-(3(trimethoxysilyl)propyl)methylamine), 1,1-(1,4-phenylene)bis(N-(3(methyl(dimethoxysilyl)propyl)methylamine), 1,1-(1,4-phenylene)bis(N-(3(trimethoxysilyl)propyl)methylamine),4-phenylene)bis(N-(3-methyl(diethoxysilyl)propyl)methylamine), 2-methoxy-2-methyl-1-(benzylideneaminoethyl)-1-aza-2-silacyclopentane, 2-methoxy-2-methyl-1-(p-methoxybenzylideneaminoethyl)-1-aza-2-silacyclopentane, 2-ethoxy-2-methyl-1-(benzylideneaminoethyl)-1-aza-2-silacyclopentane and 2-methoxy-2-methyl-1-(methylisobutyleneaminoethyl)-1-aza-2-silacyclopentane, etc.

[0477] The reaction temperature and reaction time when the coupling modifier having a nitrogen atom-containing group represented by the formula (15) is reacted with the polymerization active terminal are not particularly limited, but the reaction is preferably carried out at 0°C to 120°C for 30 seconds or more.

[0478] The amount of the coupling modifier represented by the above formula (15) to be added is preferably equal to the amount of the alkoxy group (OR 14 ) is in the range of 0.2 to 2.5 times the added molar number of the polymerization initiator, more preferably in the range of 0.5 to 2.0 times, and further preferably in the range of 1.0 to 2.0 times. From the aspect of making the modification rate and molecular weight of the obtained conjugated diene polymer in a more preferred range, it is preferably 0.2 times or more. In addition, from the aspect of suppressing the reduction of processability due to excessive increase of branching degree, it is preferably 2.5 times or less.

[0479] More specifically, the amounts of the polymerization initiator and the coupling modifier represented by the above formula (15) may be adjusted so that the molar number of the polymerization initiator is preferably 1.5 times or more, more preferably 1.7 times or more, the molar number of the coupling modifier represented by the above formula (15).

[0480] Examples of the coupling modifier having a nitrogen atom-containing group represented by the formula (16) include, but are not limited to, 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-silacyclohexane, 2,2-dimethoxy-1-(5-trimethoxysilylpentyl)-1-aza-2-silacycloheptane, 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacycloheptane, and 2,2-dimethoxy-1-(3-trimethoxymethylsilylpropyl)-1-aza-2-silacycloheptane. -1-aza-2-silacyclopentane, 2,2-diethoxy-1-(3-diethoxyethylsilylpropyl)-1-aza-2-silacyclopentane, 2-methoxy, 2-methyl-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane, 2-ethoxy, 2-ethyl-1-(3-triethoxysilylpropyl)-1-aza-2-silacyclopentane, 2-methoxy, 2-methyl-1-(3-dimethoxymethylsilylpropyl)-1-aza-2-silacyclopentane and 2-ethoxy, 2-ethyl-1-(3-diethoxyethylsilylpropyl)-1-aza-2-silacyclopentane, etc.

[0481] Among these, from the aspects of reactivity and interaction between the functional group of the coupling modifier having a group containing a nitrogen atom and an inorganic filler such as silicon oxide, and from the aspect of processability, preferred are those in which i represents 2 and h represents 3 in the above formula (16). Specifically, preferred are 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane and 2,2-diethoxy-1-(3-triethoxysilylpropyl)-1-aza-2-silacyclopentane.

[0482] The reaction temperature and reaction time in the coupling step using the coupling modifier represented by the above formula (16) are not particularly limited, but are preferably 0° C. to 120° C. for 30 seconds or more.

[0483] The amount of the coupling modifier represented by the above formula (16) is preferably such that the total molar number of the alkoxy groups bonded to the silyl groups in the compound represented by the above formula (16) is in the range of 0.2 to 2.5 times the molar number of the polymerization initiator, more preferably in the range of 0.5 to 2.0 times, and further preferably in the range of 1.0 to 2.0 times. From the perspective of making the modification rate, molecular weight and branch structure of the obtained conjugated diene polymer in a more preferred range, it is preferably 0.2 times or more. In addition, from the perspective of suppressing the reduction of processability due to excessive increase in branching degree, it is preferably 2.5 times or less.

[0484] More specifically, the amounts of the polymerization initiator and the coupling modifier represented by the above formula (16) may be adjusted so that the molar number of the polymerization initiator is preferably 3.0 times or more, more preferably 4.0 times or more, the molar number of the coupling modifier represented by the above formula (16).

[0485] Examples of the modifier having a nitrogen atom-containing group represented by the above formula (17) 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.

[0486] Among these, from the aspects of reactivity and interaction between the functional group of the modifier and the inorganic filler such as silicon oxide, as well as the aspect of processability, the substance in which n, m and l in the above formula (17) all represent 3 is preferred. As preferred specific examples, tris(3-trimethoxysilylpropyl)amine and tris(3-triethoxysilylpropyl)amine can be mentioned.

[0487] The reaction temperature and reaction time when the modifying agent having a nitrogen atom-containing group represented by the formula (17) reacts with the polymerization active terminal are not particularly limited, but the reaction is preferably carried out at 0°C to 120°C for 30 seconds or more.

[0488] The total molar number of alkoxy groups bonded to the silyl group in the coupling modifier represented by the above formula (17) is preferably in the range of 0.2 to 2.0 times the molar number of lithium constituting the above polymerization initiator, more preferably in the range of 0.5 to 2.0 times, and further preferably in the range of 0.6 to 1.6 times. From the perspective of obtaining a sufficient modification rate, molecular weight, and branched structure in the conjugated diene polymer, it is preferably 0.2 times or more, and in addition to preferably coupling the polymer ends to each other to obtain a branched polymer component in order to improve processability, it is also preferably 2.0 times or less from the perspective of the cost of the coupling modifier.

[0489] More specifically, the molar number of the polymerization initiator is preferably 4.0 times or more, more preferably 5.0 times or more, based on the molar number of the modifier.

[0490] In the above formula (18), A is preferably represented by any one of the following general formulae (i) to (iv).

[0491] [Chemistry 31]

[0492]

[0493] In the above formula (i), B 1 represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, and t represents an integer of 1 to 10. When there are plural B 1 Each one is independent.

[0494] [Chemistry 32]

[0495]

[0496] In the above formula (ii), B 2 represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, B 3 represents an alkyl group having 1 to 20 carbon atoms, and t represents an integer of 1 to 10. When a plurality of B 2 and B 3 Each one is independent.

[0497] [Chemistry 33]

[0498]

[0499] In the above formula (iii), B 4 represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, and t represents an integer of 1 to 10. When there are plural B 4 Each one is independent.

[0500] [Chemistry 34]

[0501]

[0502] In the above formula (iv), B 5 represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, and t represents an integer of 1 to 10. When there are plural B 5 Each one is independent.

[0503] When A in the above formula (18) is represented by the above formula (i), the coupling modifier having a group containing a nitrogen atom may be, for example, but 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-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)amine. (2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)amine, tris[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]amine, tetrakis(3-trimethoxysilylpropyl)-1,3-propylenediamine, tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]amine 1,3-propylenediamine, bis(3-trimethoxysilylpropyl)-bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propylenediamine, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-1,3-propylenediamine.

[0504] Other examples include tetrakis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propylenediamine, tris(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propylenediamine, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propylenediamine, bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propylenediamine, 1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, tetrakis(3-triethoxysilylpropyl)-1,3-propanediamine, tris(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, bis(3-triethoxysilylpropyl)-bis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3- Propylene diamine, tris[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)-1,3-propanediamine, tetrakis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tris(3-triethoxysilylpropyl)-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-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 Diamine, bis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)-[3-(1-ethoxy-2-trimethylsilyl-1-silacyclopentane)propyl]-1,3-propanediamine, tris[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-ethoxy-2-trimethylsilyl-1-silacyclopentane)propyl]-1,3-propanediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-bisaminomethylcyclohexane, 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, tetrakis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propylenediamine, tris(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane.

[0505] Further examples include bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-methoxy-2-trimethylsilyl-1-silacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-silacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, tris[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]- )propyl]-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, tetrakis(3-triethoxysilylpropyl)-1,3-propylenediamine, tris(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, bis(3-triethoxysilylpropyl)-bis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, tris[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-bisaminomethylcyclohexane 1,3-bisaminomethylcyclohexane, bis(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-1,3-bisaminomethylcyclohexane , bis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, tris[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-bisaminomethylcyclohexane, tetrakis(3-trimethoxysilylpropyl)-1,6-hexanediamine and penta(3-trimethoxysilylpropyl)-diethylenetriamine.

[0506] When A in the above formula (18) is represented by the above formula (ii), the coupling modifier having a group containing a nitrogen atom may be, for example, but not limited to, tris(3-trimethoxysilylpropyl)-methyl-1,3-propylenediamine, bis(2-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-methyl-1,3-propylenediamine, bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-methyl-1,3-propylenediamine, tris(3-triethoxysilylpropyl)-methyl-1,3-propylenediamine, bis(2-triethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-methyl-1,3-propylenediamine, 1,3-propanediamine, bis[3-(2,2-diethoxy-1-aza-2-silacyclopentane)propyl]-(3-triethoxysilylpropyl)-methyl-1,3-propanediamine, N1,N1'-(propane-1,3-diyl)bis(N1-methyl-N3,N3-bis(3-(trimethoxysilyl)propyl)-1,3-propanediamine), and N1-(3-(bis(3-(trimethoxysilyl)propyl)amino)propyl)-N1-methyl-N3-(3-(methyl(3-(trimethoxysilyl)propyl)amino)propyl)-N3-(3-(trimethoxysilyl)propyl)-1,3-propanediamine.

[0507] When A in the above formula (18) is represented by the above formula (iii), the coupling modifier having a group containing a nitrogen atom may be, for example, but not limited to, tetrakis[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-trimethoxysilylpropyl)silane, 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 -silanyl)propyl]silane, bis[3-(1-methoxy-2-trimethylsilyl-1-silanyl-2-azacyclopentane)-bis[3-(2,2-dimethoxy-1-aza-2-silanyl)propyl]silane, tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silanyl)propyl]silane, bis(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl)-bis[3-(2,2-dimethoxy-1-aza-2-silanyl)propyl]silane 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.

[0508] When A in the above formula (18) is represented by formula (iv), the modifier having a group containing a nitrogen atom may be, for example, but not 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-trimethoxysilylpropane.

[0509] In the above formula (18), A is preferably represented by formula (i) or formula (ii), and s represents 0.

[0510] Such coupling modifiers having groups containing nitrogen atoms tend to be easily available, and tend to have better wear resistance and low hysteresis loss performance after the conjugated diene polymer is made into a sulfide. As such coupling modifiers having groups containing nitrogen atoms, for example, but not limited to, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]amine, tris(3-trimethoxysilylpropyl)amine, tris(3-triethoxysilylpropyl)amine, tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propylenediamine, tetrakis[3-( 2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propylenediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-propylenediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-bisaminomethylcyclohexane, tris(3-trimethoxysilylpropyl)-methyl-1,3-propylenediamine and bis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-(3-trimethoxysilylpropyl)-methyl-1,3-propylenediamine, etc.

[0511] In the above formula (18), A is more preferably represented by formula (i) or formula (ii), s represents 0, and in formula (i) or formula (ii), t represents an integer of 2 to 10.

[0512] This tends to result in more excellent wear resistance and low hysteresis loss performance when vulcanized.

[0513] Examples of such coupling modifiers having a group containing a nitrogen atom include, but are not limited to, tetrakis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propylenediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-propylenediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-bisaminomethylcyclohexane, and N 1 -(3-(Bis(3-(trimethoxysilyl)propyl)amino)propyl)-N 1 -Methyl-N 3 -(3-(methyl(3-(trimethoxysilyl)propyl)amino)propyl)-N 3 -(3-(trimethoxysilyl)propyl)-1,3-propylenediamine, etc.

[0514] The amount of the compound represented by the above formula (18) as a coupling modifier having a group containing a nitrogen atom can be adjusted in such a way that the molar number of the polymerization initiator and the molar number of the coupling modifier react in a desired stoichiometric ratio, thereby tending to achieve the desired star-shaped high-branching structure.

[0515] Specifically, the molar number of the polymerization initiator is preferably 5.0 times or more, more preferably 6.0 times or more, based on the molar number of the coupling modifier.

[0516] In this case, in the above formula (18), the number of functional groups of the coupling modifier ((o-1)×q+p×r+s) is preferably an integer of 5 to 10, and more preferably an integer of 6 to 10.

[0517] The method for producing a conjugated diene polymer according to the present embodiment may include a condensation reaction step of adding a condensation accelerator to cause a condensation reaction after the step of adding a coupling modifier and / or before the step of adding a coupling modifier.

[0518] The method for producing a conjugated diene polymer according to the present embodiment may further include a modification step using a modifying agent other than the coupling modifying agent described above.

[0519] In the method for producing a conjugated diene polymer according to the present embodiment, two types of coupling modifiers may be added in the step of adding a coupling modifier, or three or more types may be added.

[0520] When two coupling modifiers are added, it is preferred to use a combination of coupling modifiers having different numbers of functional groups.

[0521] When three or more coupling modifiers are added, it is preferred to include a combination of coupling modifiers having different numbers of functional groups.

[0522] In the step of adding the coupling modifier, it is preferred to add two types of coupling modifiers having different numbers of functional groups.

[0523] Examples of the combination of two coupling modifiers having different numbers of functional groups include a combination of a coupling modifier having two or fewer functional groups and a coupling modifier having three or more functional groups.

[0524] Since a long-stemmed fork-shaped polymer is formed by bonding a fork-shaped part [A] and a linear polymer to one end of a bifunctional coupling modifier, and a star-shaped branched structure is formed by a trifunctional coupling modifier, it is preferred to use a combination of bifunctional and trifunctional or higher-functional coupling modifiers so that the long-stemmed fork-shaped part [A] and the star-shaped structure are in a desired ratio, respectively, in view of the number of active terminals after the branching agent reacts. It is preferred to add a plurality of coupling modifiers simultaneously, and they may or may not be mixed in advance.

[0525] As coupling modifiers with a functionality of less than two, specifically, coupling modifiers having structures of the above-mentioned formula (14) and formula (15) can be mentioned. As coupling modifiers with a functionality of more than three, specifically, coupling modifiers having structures of the above-mentioned formula (16), formula (17) and formula (18) can be mentioned, but there are no particular limitations.

[0526] Regarding the addition ratio of the coupling modifier with a functionality of less than 2 and the coupling modifier with a functionality of more than 3, from the viewpoint of improving the wear resistance and breaking strength of the conjugated diene copolymer, it is preferred that the mass ratio of the conjugated diene polymer having a long-shank fork-shaped portion [A] but not having a star-shaped polymer structure portion [B] is greater than the polymer having a star-shaped polymer structure portion [B] with more than 3 branches to which one or more fork-shaped portions [A] are bonded. In view of this, the molar ratio of each coupling modifier to the polymerization initiator × the number of functions is preferably coupling modifier with a functionality of less than 2: coupling modifier with a functionality of more than 3 = 9:1 to 5:5, more preferably 6:4, and even more preferably 8:2 or 7:3.

[0527] By controlling the addition ratio of the coupling modifier having two or fewer functions and the coupling modifier having three or more functions, the mass ratio of the polymer having the long-shank fork-shaped portion [A] and the polymer having the star-shaped polymer structure portion [B] can be controlled, thereby controlling the molecular weight and degree of branching of the entire conjugated diene copolymer.

[0528] As the addition ratio of the trifunctional or higher coupling modifier increases, the mass ratio of the polymer having the star-shaped polymer structure [B] increases, and the molecular weight and degree of branching of the conjugated diene copolymer as a whole increase.

[0529] The method for producing the conjugated diene polymer of the present embodiment may include a hydrogenation step of hydrogenating the conjugated diene portion. The method for hydrogenating the conjugated diene portion is not particularly limited, and a known method can be used.

[0530] As a preferred hydrogenation step, there is mentioned a method of hydrogenating the conjugated diene part by blowing gaseous hydrogen into the polymer solution in the presence of a catalyst.

[0531] The catalyst used is not particularly limited, and examples thereof include heterogeneous catalysts such as catalysts in which a noble metal is supported on a porous inorganic substance; catalysts in which a salt of nickel, cobalt, etc. is dissolved and reacted with an organic aluminum or the like; and homogeneous catalysts such as catalysts using metallocenes such as cyclopentadienyl titanium.

[0532] Among these, cyclopentadienyl titanium catalysts are preferred from the viewpoint of being able to select milder hydrogenation conditions. In addition, as a method for hydrogenating an aromatic group, a method using a noble metal supported catalyst can be cited.

[0533] In addition, as a hydrogenation process that does not use gaseous hydrogen, a method of contacting a hydrogenation catalyst with a polymer solution can be cited. Such hydrogenation catalysts are not particularly limited, and examples thereof include: (1) supported heterogeneous hydrogenation catalysts in which metals such as Ni, Pt, Pd or Ru are supported on carbon, silicon oxide, aluminum oxide or diatomaceous earth; (2) so-called Ziegler-type hydrogenation catalysts using organic acid salts of Ni, Co, Fe or Cr or transition metal salts such as acetylacetonate and reducing agents such as organic aluminum; (3) so-called organic metal complexes such as organic metal compounds of Ti, Ru, Rh or Zr; and the like. In addition, other hydrogenation catalysts are not particularly limited, and examples thereof include known hydrogenation catalysts described in Japanese Patent Publication No. 42-8704, Japanese Patent Publication No. 43-6636, Japanese Patent Publication No. 63-4841, Japanese Patent Publication No. 1-37970, Japanese Patent Publication No. 1-53851, Japanese Patent Publication No. 2-9041, and Japanese Patent Publication No. 8-109219. As a preferred hydrogenation catalyst, a reaction mixture of a cyclopentadienyl titanium compound and a reducing organometallic compound can be mentioned.

[0534] In the method for producing the conjugated diene polymer of the present embodiment, a deactivating agent and / or a neutralizing agent may be added to the polymer solution as necessary after the coupling step using a coupling modifier.

[0535] Examples of the deactivating agent include, but are not limited to, water, and alcohols such as methanol, ethanol, and isopropanol.

[0536] Examples of the neutralizing agent include, but are not limited to, carboxylic acids such as stearic acid, oleic acid, and neodecanoic acid (a mixture of multi-branched carboxylic acids having 9 to 11 carbon atoms and containing 10 carbon atoms as the main component), aqueous solutions of inorganic acids, and carbon dioxide.

[0537] The method for producing the conjugated diene polymer of the present embodiment may include a step of obtaining the obtained conjugated diene polymer from the polymer solution. As such a method, a known method may be used, and for example, the following method may be used.

[0538] That is, the following methods can be cited: a method of obtaining a polymer by filtering out the polymer after separating the solvent by steam stripping, etc., and further dehydrating and drying it; a method of obtaining a polymer by concentrating it using a flash tank and further devolatilizing it using a venting extruder, etc.; and a method of obtaining a polymer by directly devolatilizing it using a rotary dryer, etc., etc.

[0539] [Rubber composition]

[0540] The rubber composition of the present embodiment contains a rubber component including the conjugated diene polymer of the present embodiment described above.

[0541] When the conjugated diene polymer of this embodiment is mixed with a tire, the oil contained in the compact formed by the above-mentioned conjugated diene polymer is inevitably contained in the tire. When the oil filling amount is reduced in advance, the oil contained in the tire is also reduced, so there is an advantage that the freedom of composition in tire design is correspondingly improved.

[0542] The conjugated diene polymer of the present embodiment and its sheet-shaped or block-shaped molded product may be added with a rubber softener described later. From the perspective of increasing the degree of freedom in compounding design during the production of the rubber composition, the rubber softener is preferably 2 parts by mass or less, more preferably 1.5 parts by mass or less, further preferably 1 part by mass or less, and further more preferably no rubber softener is added, relative to 100 parts by mass of the conjugated diene polymer.

[0543] The rubber softener is not particularly limited, and examples thereof include extender oil, liquid rubber, and resin.

[0544] The conjugated diene polymer and its sheet-shaped or block-shaped molded product are preferably provided without adding a softener component from the viewpoint of increasing the degree of freedom in compounding design when producing a rubber composition using the molded product.

[0545] Generally, there is an upper limit to the total amount of the rubber softener relative to the entire rubber composition. However, when a softener component is added to a sheet-like or block-like molded body of a conjugated diene polymer, the rubber composition manufactured using the molded body also contains the above-mentioned softener component. Therefore, the total amount of the rubber softener relative to the entire rubber composition is suppressed, and the type and amount of the rubber softener to be mixed in the production of the rubber composition are limited. From the perspective of increasing the degree of freedom in selecting the type and amount of the rubber softener according to the performance required by the rubber composition, it is preferred to reduce the amount of the softener component added to the sheet-like or block-like molded body of the conjugated diene polymer.

[0546] Although not particularly limited, for example, by reducing the amount of extender oil added to the conjugated diene polymer of the present embodiment and its sheet-shaped or block-shaped molded product, more resin such as extender oil can be mixed when producing a rubber composition using them. This is preferred from the perspective of further improving the breaking strength of the rubber composition and its vulcanizate.

[0547] The rubber composition using the conjugated diene polymer of the present embodiment and its sheet-shaped or block-shaped molded product may further contain a rubber stabilizer from the viewpoint of suppressing gel formation and improving stability during processing.

[0548] As the rubber stabilizer, known substances may be used but are not limited thereto, and examples thereof include antioxidants such as 2,6-di-tert-butyl-4-hydroxytoluene (hereinafter also referred to as "BHT"), n-octadecyl 3-(4'-hydroxy-3',5'-di-tert-butylphenol) propionate, and 2-methyl-4,6-bis[(octylthio)methyl]phenol.

[0549] The rubber composition of the present embodiment contains 100 parts by mass of a rubber component and 5.0 parts by mass or more and 150 parts by mass or less of a filler.

[0550] The rubber component contains 10 parts by mass or more of the conjugated diene polymer of the present embodiment, based on 100 parts by mass of the total amount of the rubber component.

[0551] By dispersing the filler in the rubber component containing the conjugated diene polymer of the present embodiment, the processability during vulcanization is further improved, and a rubber composition having a vulcanized product with further excellent low hysteresis loss, fracture characteristics and wear resistance can be obtained. In addition, by containing the conjugated diene polymer of the present embodiment in a predetermined ratio in the rubber component, fuel efficiency, processability and wear resistance are further improved.

[0552] As fillers, for example, silicon oxide-based inorganic fillers, carbon black, metal oxides and metal hydroxides can be cited but are not limited thereto. Among these, silicon oxide-based inorganic fillers are preferred. In particular, when the rubber composition of the present embodiment is used for vulcanized rubber applications such as tires, anti-vibration rubbers and other automotive parts, shoes, etc., it is particularly preferred to include silicon oxide-based inorganic fillers. Such fillers can be used alone or in combination of two or more.

[0553] There is no particular limitation on the silicon oxide-based inorganic filler, and known materials can be used, preferably solid particles containing SiO2 or Si3Al as structural units, and more preferably solid particles containing SiO2 or Si3Al as the main component of the structural unit. Here, the main component refers to a component containing more than 50% by mass, preferably 70% by mass or more, and more preferably 80% by mass or more in the silicon oxide-based inorganic filler.

[0554] As specific silicon oxide-based inorganic fillers, inorganic fibrous materials such as silicon oxide, clay, talc, mica, diatomaceous earth, wollastonite, montmorillonite, zeolite and glass fiber can be cited but not limited to. In addition, a mixture of silicon oxide-based inorganic fillers and inorganic fillers other than silicon oxide-based inorganic fillers and silicon oxide-based inorganic fillers whose surfaces have been hydrophobized can also be used. Among these, from the aspect of further improving the strength and wear resistance of the rubber composition, silicon oxide or glass fiber are preferred, and silicon oxide is more preferred. As silicon oxide, it is not particularly limited, for example, dry silicon oxide, wet silicon oxide and synthetic silicate silicon oxide can be cited. Among these silicon oxides, from the aspect of further improving the breaking strength of the rubber composition, wet silicon oxide is preferred.

[0555] From the viewpoint of more reliably obtaining a rubber composition having practically good wear resistance and breaking strength, the nitrogen adsorption specific surface area of ​​the silica-based inorganic filler determined by the BET adsorption method is preferably 100 m 2 / g above 300m 2 / g or less, more preferably 170m 2 / g above 250m 2 / g or less. In addition, the specific surface area can be smaller (for example, the specific surface area is less than 200m 2 / g) of silicon oxide-based inorganic fillers and larger specific surface areas (e.g., 200 m 2 / g or more) of a silicon oxide-based inorganic filler. In this embodiment, in particular, by using a large specific surface area (e.g., 200 m 2 / g or more) of a silica-based inorganic filler, the dispersibility of silica tends to be further improved in the conjugated diene polymer. As a result, the obtained rubber composition tends to have more excellent wear resistance, breaking strength and low hysteresis loss.

[0556] Examples of carbon black include, but are not limited to, various grades of carbon black such as SRF, FEF, HAF, ISAF, and SAF. Among these, carbon black having a nitrogen adsorption specific surface area of ​​50 m2 as determined by the BET adsorption method is preferred. 2 / g or more and a dibutyl phthalate (DBP) oil absorption of 80mL / 100g or less.

[0557] As a metal oxide, as long as the chemical formula M x O y (M represents a metal atom, and x and y each independently represent an integer of 1 to 6) The solid particles as a main component of the structural unit are not particularly limited, and examples thereof include aluminum oxide, titanium oxide, magnesium oxide, and zinc oxide.

[0558] Examples of the metal hydroxide include, but are not limited to, aluminum hydroxide, magnesium hydroxide, and zirconium hydroxide.

[0559] The content of the filler in the rubber composition of the present embodiment is 5.0 to 150 parts by mass, preferably 20 to 100 parts by mass, more preferably 30 to 90 parts by mass, relative to 100 parts by mass of the rubber component. When the filler is within the above range, the rubber composition tends to have better processability during vulcanization, and its vulcanized product tends to have better low hysteresis loss, fracture characteristics, and wear resistance.

[0560] In the rubber composition of the present embodiment, from the perspective of surely imparting dry grip performance and electrical conductivity, which are required for tires and other applications, the rubber composition preferably contains 0.5 to 100 parts by mass of carbon black relative to 100 parts by mass of the rubber component containing the conjugated diene polymer. From the same perspective, the rubber composition more preferably contains 3.0 to 100 parts by mass of carbon black, and further preferably contains 5.0 to 50 parts by mass of carbon black relative to 100 parts by mass of the rubber component containing the conjugated diene polymer.

[0561] The rubber composition of the present embodiment may further contain a silane coupling agent. The rubber composition containing the silane coupling agent can further enhance the interaction between the rubber component and the filler.

[0562] As the silane coupling agent, for example, a compound having a sulfur bonding portion and an alkoxysilyl group or a silanol group portion in one molecule is preferred but not limited thereto. Such a compound may include, but is not limited to, bis-[3-(triethoxysilyl)-propyl]-tetrasulfide, bis-[3-(triethoxysilyl)-propyl]-disulfide, and bis-[2-(triethoxysilyl)-ethyl]-tetrasulfide.

[0563] In the rubber composition of the present embodiment, the content of the silane coupling agent is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 20 parts by mass, and even more preferably 1.0 to 15 parts by mass, relative to 100 parts by mass of the filler. If the content of the silane coupling agent is within the above range, there is a tendency to further enhance the interaction between the rubber component and the filler.

[0564] The rubber composition of the present embodiment may contain a rubbery polymer other than the conjugated diene polymer of the present embodiment (hereinafter referred to as "rubbery polymer") as a rubber component. The conjugated diene polymer of the present embodiment and the rubbery polymer are collectively described as "rubber component".

[0565] As the rubbery polymer, for example, conjugated diene polymers and hydrogenated products thereof, random copolymers of conjugated diene compounds and vinyl aromatic compounds and hydrogenated products thereof, block copolymers of conjugated diene compounds and vinyl aromatic compounds and hydrogenated products thereof, non-diene polymers, and natural rubber, etc. can be cited but are not limited thereto. It should be noted that the rubbery polymers other than the conjugated diene polymers of the present embodiment do not satisfy all of the conditions in the above <condition (i)> to <condition (iii)>, and in this respect can be distinguished from the conjugated diene polymers of the present embodiment.

[0566] Examples of the rubber-like polymer include, but are not limited to, styrene-based elastomers such as butadiene rubber and its hydrogenates, isoprene rubber and its hydrogenates, styrene-butadiene rubber and its hydrogenates, styrene-butadiene block copolymers and their hydrogenates, styrene-isoprene block copolymers and their hydrogenates, and nitrile rubber and its hydrogenates.

[0567] Examples of non-diene polymers include, but are not limited to, olefin elastomers such as ethylene-propylene rubber, ethylene-propylene-diene rubber, ethylene-butene-diene rubber, ethylene-butene rubber, ethylene-hexene rubber, and ethylene-octene rubber, butyl rubber, brominated butyl rubber, acrylic rubber, fluororubber, silicone rubber, chlorinated polyethylene rubber, epichlorohydrin rubber, α,β-unsaturated nitrile-acrylate-conjugated diene copolymer rubber, urethane rubber, and polysulfide rubber.

[0568] Examples of the natural rubber include, but are not limited to, RSS No. 3 to No. 5 smoked sheet rubber, SMR, and epoxidized natural rubber.

[0569] The rubbery polymer may be a modified rubber to which a polar functional group such as a hydroxyl group or an amino group is added. When the rubber composition of the present embodiment is used as a material for a tire, the rubbery polymer is preferably one or more selected from the group consisting of butadiene rubber, isoprene rubber, styrene-butadiene rubber, natural rubber, and butyl rubber.

[0570] From the aspect of the balance between the wear resistance, breaking strength, low hysteresis loss and processability of the rubber composition, the weight average molecular weight of the rubber-like polymer is preferably 2000 to 2000000, more preferably 5000 to 1500000. In addition, as the rubber-like polymer, a low molecular weight rubber-like polymer or so-called liquid rubber may also be used. These rubber-like polymers may be used alone or in combination of two or more.

[0571] When the rubber composition of the present embodiment contains the conjugated diene polymer of the present embodiment and a rubbery polymer, the content ratio (mass ratio) of the conjugated diene polymer of the present embodiment relative to the rubbery polymer, i.e., (conjugated diene polymer / rubbery polymer) is preferably 10 / 90 to 100 / 0, more preferably 20 / 80 to 90 / 10, and further preferably 30 / 70 to 80 / 20.

[0572] That is, in the rubber component, the conjugated diene polymer of the present embodiment preferably contains 10 to 100 parts by mass, more preferably 20 to 90 parts by mass, and further preferably 30 to 80 parts by mass, relative to 100 parts by mass of the total amount of the rubber component. If the ratio of the conjugated diene polymer contained in the rubber component is within the above range, the wear resistance and low hysteresis loss of the vulcanized rubber composition tend to be more excellent.

[0573] To the rubber composition of the present embodiment, a rubber softener may be added in addition to the rubber component in order to further improve the processability thereof.

[0574] The rubber softener is not particularly limited, and examples thereof include liquid rubber, resin, and extender oil.

[0575] The liquid rubber is not particularly limited, and examples thereof include liquid polybutadiene and liquid styrene-butadiene rubber.

[0576] When a liquid rubber is used as the rubber softener, in addition to the above-mentioned effects, the glass transition temperature of the rubber composition can be further lowered, so that the wear resistance, low hysteresis loss and low-temperature characteristics of the vulcanizate thereof tend to be further improved.

[0577] Examples of the resin include, but are not limited to, aromatic petroleum resins, coumarone-indene resins, terpene resins, rosin derivatives (including tung oil resins), tall oil, tall oil derivatives, rosin ester resins, natural and synthetic terpene resins, aliphatic hydrocarbon resins, aromatic hydrocarbon resins, hydrocarbon resins such as mixed aliphatic-aromatic hydrocarbon resins, coumarin-indene resins, phenol resins, p-tert-butylphenol-acetylene resins, phenol-formaldehyde resins, xylene-formaldehyde resins, oligomers of monoolefins, oligomers of dienes, hydrogenated hydrocarbon resins such as hydrogenated aromatic hydrocarbon resins, cyclic aliphatic hydrocarbon resins, hydrogenated tung oil resins, hydrogenated oil resins, and esters of hydrogenated oil resins with monofunctional or polyfunctional alcohols.

[0578] These resins may be used alone or in combination of two or more. In addition, when these resins are hydrogenated, all of the unsaturated groups may be hydrogenated or a part of them may remain.

[0579] When a resin is used as the rubber softener, in addition to the above-mentioned effects, there is a tendency that the breaking strength of the vulcanized product of the rubber composition is further improved.

[0580] In the rubber composition of the present embodiment, in order to further improve the fracture strength of the vulcanized product, it is suitable to add a resin as a rubber softener in addition to the rubber component.

[0581] To further improve the processability of the rubber composition of the present embodiment, a rubber softener may be added in addition to the rubber component, and mineral oil or a liquid or low-molecular weight synthetic softener is suitable.

[0582] Examples of the filler oil include aromatic oils, cycloparaffin oils, and paraffin oils. Among these, from the perspective of environmental safety, preventing oil seepage, and improving wet grip, alternative aromatic oils having a polycyclic aromatic (PCA) content of 3% by mass or less based on the IP346 method are preferred. Alternative aromatic oils are not particularly limited, and examples thereof include TDAE (Treated Distillate Aromatic Extracts), MES (Mild Extraction Solvate), and RAE (Residual Aromatic Extracts) shown in Kautschuk Gummi Kunststoffe 52 (12) 799 (1999).

[0583] The mineral oil-based rubber softener called process oil or extender oil used to soften, increase volume and improve processability of rubber is a mixture of aromatic rings, cycloalkane rings and paraffin chains. Among them, substances whose carbon atoms belonging to the paraffin chain account for more than 50% of the total carbon atoms are called paraffin series, substances whose carbon atoms belonging to the cycloalkane ring account for more than 30% and less than 45% of the total carbon atoms are called cycloalkane series, and substances whose carbon atoms belonging to the aromatic group account for more than 30% of the total carbon atoms are called aromatic series. In the rubber composition of this embodiment, as a rubber softener, it is preferred to include a rubber softener with a moderate aromatic content. By including such a rubber softener, the affinity with the conjugated diene polymer is further improved.

[0584] The content of the rubber softener in the rubber composition of the present embodiment is represented by the amount of the rubber softener previously added to the conjugated diene polymer of the present embodiment and the rubbery polymer, and the total amount of the rubber softener added when preparing the rubber composition.

[0585] In the rubber composition of the present embodiment, the content of the rubber softener is preferably 0 to 100 parts by mass, more preferably 10 to 90 parts by mass, and further preferably 30 to 90 parts by mass, relative to 100 parts by mass of the rubber component. By setting the content of the rubber softener to 100 parts by mass or less relative to 100 parts by mass of the rubber component, it is possible to suppress bleeding and further suppress stickiness on the surface of the rubber composition.

[0586] The rubber composition of the present embodiment can be produced by mixing the conjugated diene polymer of the present embodiment, a rubbery polymer other than the conjugated diene polymer of the present embodiment, a filler, and, if necessary, a silane coupling agent, a rubber softener, and other additives.

[0587] The mixing method is not particularly limited, and examples thereof include a melt-kneading method using a common mixer such as an open roll mill, Banbury mixer, kneader, single-screw extruder, twin-screw extruder or multi-screw extruder; and a method of melt-kneading the components and then heating to remove the solvent.

[0588] Among these, the melt kneading method using a roll, a Banbury mixer, a kneader or an extruder is preferred from the perspective of productivity and good kneadability. In addition, the rubber component, the filler, the silane coupling agent, the rubber softener and the additive may be kneaded at one time or may be mixed in multiple times.

[0589] The rubber composition of the present embodiment may be a sulfide subjected to a vulcanization treatment using a vulcanizing agent. Examples of the vulcanizing agent include, but are not limited to, free radical initiators such as organic peroxides and azo compounds, oxime compounds, nitroso compounds, polyamine compounds, sulfur, and sulfur-containing compounds. Sulfur-containing compounds include sulfur monochloride, sulfur dichloride, disulfide compounds, and high molecular weight polysulfide compounds.

[0590] In the rubber composition of the present embodiment, the content of the vulcanizing agent is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, relative to 100 parts by mass of the rubber component. As a vulcanization method, a conventionally known method can be used. In addition, as a vulcanization temperature, it is preferably 120°C to 200°C, more preferably 140°C to 180°C.

[0591] When the rubber composition is vulcanized, a vulcanization accelerator and / or a vulcanization aid may be used as needed. As the vulcanization accelerator, a conventionally known material may be used, and examples thereof include, but are not limited to, sulfenamide-based, guanidine-based, thiuram-based, aldehyde-amine-based, aldehyde-ammonia-based, thiazole-based, thiourea-based, and dithiocarbamate-based vulcanization accelerators.

[0592] Examples of the vulcanization aid include, but are not limited to, zinc white and stearic acid.

[0593] The content of the vulcanization accelerator and the vulcanization aid is preferably 0.01 to 20 parts by mass, and more preferably 0.1 to 15 parts by mass, respectively, relative to 100 parts by mass of the rubber component.

[0594] In the rubber composition of the present embodiment, various additives such as softeners and fillers other than the above, heat stabilizers, antistatic agents, weather stabilizers, anti-aging agents, colorants, and slip agents can be used within the range that does not hinder the effect of the present embodiment. As a softener, a known softener can be used. As a filler, there is no particular limitation, and specifically, for example, calcium carbonate, magnesium carbonate, aluminum sulfate, and barium sulfate can be cited. As heat stabilizers, antistatic agents, weather stabilizers, anti-aging agents, colorants, and lubricants, known materials can be used respectively.

[0595] [tire]

[0596] The tire of the present embodiment contains the rubber composition of the present embodiment described above.

[0597] As tires of this embodiment, various tires such as fuel-saving tires, all-season tires, high-performance tires and studless tires can be cited but are not limited to them. The rubber composition of this embodiment can be appropriately used in various parts of the tire such as the tread, tire carcass, bead and bead portion.

[0598] In addition, the numerical range described above as a preferred range or the like can be replaced by a numerical range consisting of any combination of each value described as an upper limit and each value described as a lower limit, unless otherwise specified.

[0599] Example

[0600] The present embodiment will be described in further detail below with reference to specific examples and comparative examples, but the present invention is not limited to the following examples and comparative examples.

[0601] Various physical properties in Examples and Comparative Examples were measured by the methods shown below.

[0602] Hereinafter, the polymer before modification with the coupling modifier is referred to as “unmodified conjugated diene polymer”, and the polymer after modification with the coupling modifier is referred to as “modified conjugated diene polymer”.

[0603] In addition, "conjugated diene polymer" may be described as a general term for polymers before and after modification with a coupling modifier.

[0604] (Physical Property 1) Average Molecular Weight Measured by GPC Measurement

[0605] GPC measurement was performed using an unmodified conjugated diene polymer and a modified conjugated diene polymer as samples, using a GPC measuring apparatus (trade name "HLC-8320GPC" manufactured by Tosoh Corporation) connected to three columns using polystyrene gel as a filler, and a refractive index (RI) detector (trade name "HLC8020" manufactured by Tosoh Corporation). Based on a calibration curve obtained using standard polystyrene, the weight average molecular weight (Mw), number average molecular weight (Mn) and molecular weight distribution (Mw / Mn) were determined.

[0606] A 5 mmol / L triethylamine-THF (tetrahydrofuran) solution was used as the eluent. Three columns of "TSKgel SuperMultiporeHZ-H" manufactured by Tosoh Corporation were connected, and a "TSKguardcolumn SuperMP(HZ)-H" manufactured by Tosoh Corporation was connected to the front of the column as a guard column.

[0607] 10 mg of a measurement sample was dissolved in 10 mL of THF to prepare a measurement solution, 10 μL of the measurement solution was injected into a GPC measurement device, and measurement was performed under the conditions of an oven temperature of 40° C. and a THF flow rate of 0.35 mL / min.

[0608] The measurement results were defined as the average molecular weights of the samples.

[0609] (Physical Property 2) Polymer Mooney Viscosity

[0610] The Mooney viscosity of the unmodified conjugated diene polymer and the modified conjugated diene polymer as samples was measured using a Mooney viscometer (trade name "VR1132" manufactured by Ueshima Seisakusho Co., Ltd.) in accordance with ISO 289 with an L-shaped rotor.

[0611] The measurement temperature was 110° C. when an unmodified conjugated diene polymer was used as a sample, and 100° C. when a modified conjugated diene polymer was used as a sample.

[0612] After the sample was preheated at the test temperature for 1 minute, the rotor was rotated at 2 rpm and the torque was measured after 4 minutes to determine the Mooney viscosity (ML (1+4) ).

[0613] (Physical Property 3) Mooney Stress Relaxation Rate

[0614] Using an unmodified conjugated diene polymer and a modified conjugated diene polymer as samples, the Mooney viscosity was measured using a Mooney viscometer (trade name "VR1132" manufactured by Ueshima Seisakusho Co., Ltd.) using an L-shaped rotor in accordance with ISO 289. The rotation of the rotor was immediately stopped, and the torque was recorded in Mooney units every 0.1 seconds from 1.6 seconds to 5 seconds after the stop. The torque and time (seconds) were plotted in double logarithmic form, and the slope of the straight line at this time was calculated, and its absolute value was taken as the Mooney stress relaxation rate (MSR).

[0615] The measurement temperature was 110° C. when an unmodified conjugated diene polymer was used as a sample, and 100° C. when a modified conjugated diene polymer was used as a sample.

[0616] (Physical Properties 4, 8) Branching Distribution Curve and Absolute Molecular Weight

[0617] The modified conjugated diene polymer was used as a sample, and a GPC measuring apparatus (trade name "GPCmax VE-2001" manufactured by Malvern Co.) to which three columns using polystyrene gel as a filler were connected was used for measurement, and three detectors were connected in order: a light scattering detector, an RI detector, and a viscosity detector (trade name "TDA305" manufactured by Malvern Co.). Based on standard polystyrene, the absolute molecular weight was calculated from the results of the light scattering detector and the RI detector, and the intrinsic viscosity was calculated from the results of the RI detector and the viscosity detector.

[0618] Assume that the linear polymer follows the intrinsic viscosity [η0] = 10 -3.498 M 0.711 , the shrinkage factor (g') was calculated as the ratio of the intrinsic viscosity corresponding to each molecular weight. In the above formula, M is the absolute molecular weight.

[0619] As the eluent, THF to which 5 mmol / L triethylamine was added was used.

[0620] As columns, trade names "TSKgel G4000HXL", "TSKgel G5000HXL" and "TSKgel G6000HXL" manufactured by Tosoh Corporation were connected and used.

[0621] 20 mg of a sample for measurement was dissolved in 10 mL of THF to prepare a measurement solution. 100 μL of the measurement solution was injected into a GPC measurement device and measurement was performed under the conditions of an oven temperature of 40° C. and a THF flow rate of 1 mL / min.

[0622] The absolute molecular weight distribution curve and branching distribution curve of the modified conjugated diene polymer were obtained by the above measurement, and the branching degree (Bn) defined as g'=6Bn / {(Bn+1)(Bn+2)} was calculated using the contraction factor (g').

[0623] Taking the height Hi of the peak in the absolute molecular weight distribution curve as a reference, the degree of branching Bn(high) of the conjugated diene copolymer at the highest absolute molecular weight Mw(high) of at least two absolute molecular weights when the height in the absolute molecular weight distribution curve is 1 / 2 of the height Hi (1 / 2Hi), the degree of branching Bn(low) of the conjugated diene copolymer at the lowest absolute molecular weight Mw(low), and the degree of branching Bn(top) of the conjugated diene copolymer at the peak of the absolute molecular weight distribution curve are calculated. Further, (Bn(high))-(Bn(top)), (Bn(low))-(Bn(top)), (Bn(high)) / (Bn(low)) are calculated.

[0624] (Physical Property 5) Modification Rate

[0625] The modification ratios of the polymer before modification with the coupling modifier (conjugated diene polymer) and the polymer after modification with the coupling modifier (modified conjugated diene polymer) were measured by column adsorption GPC method as follows.

[0626] The column adsorption GPC method is a method for determining the modification rate of the modified polymer by utilizing the property that the modified basic polymer component in the modified conjugated diene polymer is easily adsorbed on a GPC column using a silica gel as a filler.

[0627] Each polymer was used as a sample, and a sample solution containing the sample and low molecular weight internal standard polystyrene was measured using a polystyrene column.

[0628] Furthermore, the same sample solution was measured using a silica column.

[0629] The difference between the chromatogram obtained by measurement using a polystyrene column and the chromatogram obtained by measurement using a silica column was determined to measure the amount of adsorption on the silica column and to determine the modification rate.

[0630] <Preparation of sample solution>:

[0631] 10 mg of a sample and 5 mg of standard polystyrene were dissolved in 10 mL of THF to prepare a sample solution. The modification ratios of the conjugated diene polymer and the modified conjugated diene polymer were measured under the following measurement conditions.

[0632] <GPC Measurement Conditions Using Polystyrene Column>

[0633] The GPC measurement was performed using a trade name "HLC-8320GPC" manufactured by Tosoh Corporation and an RI detector (trade name "HLC8020" manufactured by Tosoh Corporation).

[0634] Using 5 mmol / L triethylamine-THF solution as an eluent, 10 μL of the sample solution was injected into the GPC device, and a chromatogram was obtained under the conditions of a column temperature of 40° C. and a THF flow rate of 0.35 mL / min.

[0635] As the column, three columns of "TSKgel Super Multipore HZ-H" manufactured by Tosoh Corporation were connected, and a "TSKguardcolumn Super MP(HZ)-H" manufactured by Tosoh Corporation was connected to the front stage as a guard column for use.

[0636] <GPC Measurement Conditions Using Silica Column>

[0637] The GPC measurement was performed using a trade name "HLC-8320GPC" manufactured by Tosoh Corporation and an RI detector (trade name "HLC8020" manufactured by Tosoh Corporation).

[0638] Using THF as an eluent, 50 μL of the sample solution was injected into the device, and a chromatogram was obtained under the conditions of a column oven temperature of 40° C. and a THF flow rate of 0.5 ml / min.

[0639] As columns, trade names "Zorbax PSM-1000S", "PSM-300S" and "PSM-60S" manufactured by Agilent were connected in order, and trade name "DIOL 4.6×12.5 mm 5 micron" was connected in front of them as a guard column for use.

[0640] Calculation method of modification rate:

[0641] For the chromatogram obtained by measurement using a polystyrene column, the peak area P1 of the sample and the peak area P2 of the standard polystyrene were calculated by setting the overall peak area to 100. In addition, for the chromatogram obtained by measurement using a silica column, the peak area P3 of the sample and the peak area P4 of the standard polystyrene were calculated by setting the overall peak area to 100. The modification rate (mass %) was calculated by the following formula.

[0642] Modification rate (mass %) = [1 - (P2 × P3) / (P1 × P4)] × 100

[0643] (where P1+P2=P3+P4=100)

[0644] (Physical Property 6) Amount of Bonded Vinyl Aromatic Monomer Units (Amount of Bonded Styrene)

[0645] A modified conjugated diene polymer was used as a sample, and 100 mg of the sample was dissolved in 100 mL of chloroform to prepare a measurement sample.

[0646] Each sample was measured using a spectrophotometer (trade name "UV-2450" manufactured by Shimadzu Corporation) to obtain an absorption spectrum. The amount of bonded styrene (mass %) relative to 100 mass % of the modified conjugated diene polymer was calculated from the amount of ultraviolet light (near 254 nm) absorbed by the phenyl group derived from styrene.

[0647] (Physical Property 7) Amount of Vinyl Bonds in Bonded Conjugated Diene (Amount of 1,2-Vinyl Bonds in Bonded Butadiene)

[0648] Using the modified conjugated diene polymer as a sample, 50 mg of the sample was dissolved in 10 mL of carbon disulfide to prepare a measurement sample.

[0649] Fourier transform infrared spectrophotometer (trade name "FT-IR230" manufactured by JASCO Corporation) was used to measure the -1 The infrared spectrum of each sample was measured within the range of .

[0650] The amount (mol %) of 1,2-vinyl bonds in the bonded butadiene was determined from the absorbance at a specific wave number according to the Hampton method (described by RR Hampton, Analytical Chemistry 21, 923 (1949)).

[0651] (Physical Property 9) Glass Transition Temperature (Glass Transition Point)

[0652] The modified conjugated diene polymer was used as a sample and DSC measurement was performed using a differential scanning calorimeter (trade name "DSC3200S" manufactured by MAC Science) in accordance with ISO 22768:2006. The DSC curve was recorded while the temperature was raised from -100°C at 20°C / min under a helium flow of 50 mL / min, and the peak top (inflection point) of the DSC differential curve was taken as the glass transition temperature (glass transition point).

[0653] (Example 1) Modified conjugated diene polymer (A1)

[0654] Two tank-type pressure vessels equipped with a stirrer and a jacket for temperature control were connected as polymerization branch reactors. The tank-type pressure vessel had an internal volume of 10 L, a ratio (L / D) of internal height (L) to diameter (D) of 4.0, an inlet at the bottom, and an outlet at the top.

[0655] 1,3-butadiene, styrene and n-hexane from which water had been removed in advance were mixed at 18.5 g / min, 6.2 g / min and 117.4 g / min, respectively, and continuously supplied to the bottom of the first reactor. It should be noted that, during the above supply, n-butyl lithium for inertizing residual impurities was mixed at 0.096 mmol / min using a static mixer and continuously added just before the mixed solution was added to the first reactor. In addition, while supplying 1,3-butadiene, styrene, n-hexane and n-butyl lithium, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound and n-butyl lithium as a polymerization initiator (indicated as "d-1" in Table 1) were supplied to the bottom of the first reactor at 0.049 mmol / min and 0.202 mmol / min, respectively, while the reaction solution was vigorously stirred with a stirrer. It should be noted that the temperature in the first reactor was maintained at 82°C.

[0656] The conjugated diene polymer solution produced by the polymerization reaction in the first reactor was continuously extracted from the top of the first reactor and continuously supplied to the bottom of the second reactor. When the polymerization was sufficiently stable, trimethoxy(4-vinylphenyl)silane (indicated as "c-1" in Table 1) as a branching agent was supplied from the bottom of the second reactor at a rate of 0.006 mmol / min while copolymerizing 1,3-butadiene and styrene, and additional 1,3-butadiene was further added at a rate of 6.2 g / min to perform a polymerization branching step.

[0657] It should be noted that the temperature in the second reactor was maintained at 86° C. The conjugated diene polymer solution was withdrawn in small amounts from the outlet of the second reactor, an antioxidant (BHT) was added in an amount of 0.2 g per 100 g of the conjugated diene polymer, and then the solvent was removed. For the obtained conjugated diene polymer, various molecular weights measured by GPC, as well as the Mooney viscosity and Mooney stress relaxation rate at 110° C. were measured.

[0658] The physical properties are shown in Table 1 (physical properties 1-1, 1-2, 1-3, physical properties 2, physical properties 3).

[0659] Next, the conjugated diene polymer solution flowing out from the top of the second reactor is supplied to the static mixer. Further, 1-methyl-4-(3-(trimethoxysilyl)propyl)piperazine (indicated as "a-1" in Table 1) is continuously added to the conjugated diene polymer solution continuously flowing into the static mixer at a condition of 0.104 mmol / min, and tetrakis(3-trimethoxysilylpropyl)-1,3-propylenediamine (indicated as "b-1" in Table 1) is continuously added at a condition of 0.003 mmol / min as a coupling modifier, thereby coupling the conjugated diene polymer. At this time, the time until the coupling modifier is added to the polymer solution flowing out from the outlet of the second reactor is 4.8 minutes, and the temperature of the polymer solution when the coupling modifier is added is 68°C. In addition, the difference between the temperature of the polymer solution at the outlet of the second reactor and the temperature of the polymer solution when the coupling modifier is added is 2°C.

[0660] Next, a n-hexane solution of an antioxidant (BHT) was continuously added to the polymer solution flowing out of the static mixer at a condition of 0.055 g / min in a manner that the antioxidant (BHT) in every 100 g of polymer was 0.2 g, so that the coupling reaction was terminated. The solvent was removed by steam stripping, and the mixture was formed into a compact, thereby obtaining a modified conjugated diene polymer (A1). Various physical properties of the obtained modified conjugated diene polymer (A1) were measured.

[0661] Table 1 shows the measurement results.

[0662] (Example 2) Modified conjugated diene polymer (A2)

[0663] A modified conjugated diene polymer (A2) was obtained in the same manner as in Example 1 except that c-1 as a branching agent was supplied at 0.011 mmol / min, and a-1 and b-1 as coupling modifiers were supplied at 0.093 mmol / min and 0.006 mmol / min, respectively.

[0664] Table 1 shows the physical properties of the modified conjugated diene polymer (A2).

[0665] (Example 3) Modified conjugated diene polymer (A3)

[0666] A modified conjugated diene polymer (A3) was obtained in the same manner as in Example 1 except that d-1 as a polymerization initiator was supplied at 0.193 mmol / min, c-1 as a branching agent was supplied at 0.011 mmol / min, and a-1 and b-1 as coupling modifiers were supplied at 0.077 mmol / min and 0.008 mmol / min, respectively.

[0667] Table 1 shows the physical properties of the modified conjugated diene polymer (A3).

[0668] (Example 4) Modified conjugated diene polymer (A4)

[0669] A modified conjugated diene polymer (A4) was obtained in the same manner as in Example 1 except that d-1 as a polymerization initiator was supplied at 0.193 mmol / min, c-1 as a branching agent was supplied at 0.011 mmol / min, and a-1 and b-1 as coupling modifiers were supplied at 0.066 mmol / min and 0.011 mmol / min, respectively.

[0670] Table 1 shows the physical properties of the modified conjugated diene polymer (A4).

[0671] (Example 5) Modified conjugated diene polymer (A5)

[0672] A modified conjugated diene polymer (A5) was obtained in the same manner as in Example 1 except that d-1 as a polymerization initiator was supplied at 0.193 mmol / min, c-1 as a branching agent was supplied at 0.011 mmol / min, and a-1 and b-1 as coupling modifiers were supplied at 0.056 mmol / min and 0.014 mmol / min, respectively.

[0673] Table 1 shows the physical properties of the modified conjugated diene polymer (A5).

[0674] (Example 6) Modified conjugated diene polymer (A6)

[0675] A modified conjugated diene polymer (A6) was obtained in the same manner as in Example 1 except that d-1 as a polymerization initiator was supplied at 0.193 mmol / min, c-1 as a branching agent was supplied at 0.011 mmol / min, and a-1 and b-1 as coupling modifiers were supplied at 0.033 mmol / min and 0.019 mmol / min, respectively.

[0676] Table 1 shows the physical properties of the modified conjugated diene polymer (A6).

[0677] (Example 7) Modified conjugated diene polymer (A7)

[0678] A modified conjugated diene polymer (A7) was obtained in the same manner as in Example 1 except that d-1 as a polymerization initiator was supplied at 0.173 mmol / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.045 mmol / min, c-1 as a branching agent was supplied at 0.010 mmol / min, and a-1 and b-1 as coupling modifiers were supplied at 0.071 mmol / min and 0.007 mmol / min, respectively.

[0679] Table 2 shows the physical properties of the modified conjugated diene polymer (A7).

[0680] (Example 8) Modified conjugated diene polymer (A8)

[0681] A modified conjugated diene polymer (A8) was obtained in the same manner as in Example 1 except that d-1 as a polymerization initiator was supplied at 0.221 mmol / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.054 mmol / min, c-1 as a branching agent was supplied at 0.012 mmol / min, and a-1 and b-1 as coupling modifiers were supplied at 0.088 mmol / min and 0.009 mmol / min, respectively.

[0682] Table 2 shows the physical properties of the modified conjugated diene polymer (A8).

[0683] (Example 9) Modified conjugated diene polymer (A9)

[0684] A modified conjugated diene polymer (A8) was obtained in the same manner as in Example 1 except that d-1 as a polymerization initiator was supplied at 0.193 mmol / min, c-1 as a branching agent was supplied at 0.022 mmol / min, and a-1 and b-1 as coupling modifiers were supplied at 0.077 mmol / min and 0.008 mmol / min, respectively.

[0685] Table 2 shows the physical properties of the modified conjugated diene polymer (A9).

[0686] (Example 10) Modified conjugated diene polymer (A10)

[0687] A modified conjugated diene polymer (A10) was obtained in the same manner as in Example 1 except that d-1 as a polymerization initiator was supplied at 0.193 mmol / min, c-1 as a branching agent was supplied at 0.022 mmol / min, and a-1 and b-1 as coupling modifiers were supplied at 0.033 mmol / min and 0.019 mmol / min, respectively.

[0688] Table 2 shows the physical properties of the modified conjugated diene polymer (A10).

[0689] (Example 11) Modified conjugated diene polymer (A11)

[0690] A modified conjugated diene polymer (A11) was obtained in the same manner as in Example 1 except that d-1 as a polymerization initiator was supplied at 0.193 mmol / min, c-1 as a branching agent was supplied at 0.011 mmol / min, and a-1 and b-1 as coupling modifiers were supplied at 0.054 mmol / min and 0.006 mmol / min, respectively.

[0691] Table 2 shows the physical properties of the modified conjugated diene polymer (A11).

[0692] (Example 12) Modified conjugated diene polymer (A12)

[0693] The two connected tank-type pressure vessels were changed to a vessel with an internal volume of 15 L and an internal height (L) to diameter (D) ratio (L / D) of 6.0, and 1,3-butadiene was supplied at 10.4 g / min, styrene was supplied at 4.0 g / min, n-hexane was supplied at 66.9 g / min, n-butyl lithium for impurity treatment was supplied at 0.062 mmol / min, d-1 as a polymerization initiator was supplied at 0.125 mmol / min, and 2,2-bis(2-tetrakis) as a polar compound was supplied. The modified conjugated diene polymer (A12) was obtained in the same manner as in Example 1 except that 0.031 mmol / min of 1,3-butadiene was added, 5.6 g / min of 1,3-butadiene was added, 0.007 mmol / min of c-1 as a branching agent, 0.057 mmol / min of a-1 and 0.004 mmol / min of b-1 as coupling modifiers, respectively, and the temperature of the first reactor was 68° C. and the temperature of the second reactor was 86° C. The physical properties of the modified conjugated diene polymer (A12) are shown in Table 2.

[0694] (Example 13) Modified conjugated diene polymer (A13)

[0695] A modified conjugated diene polymer (A13) was obtained in the same manner as in Example 1 except that d-1 as a polymerization initiator was supplied at 0.193 mmol / min, c-1 as a branching agent was supplied at 0.011 mmol / min, and a-1 and 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane (represented as "b-2" in the table) as coupling modifiers were supplied at 0.077 mmol / min and 0.016 mmol / min, respectively.

[0696] Table 3 shows the physical properties of the modified conjugated diene polymer (A13).

[0697] (Example 14) Modified conjugated diene polymer (A14)

[0698] A modified conjugated diene polymer (A14) was obtained in the same manner as in Example 1 except that 1,3-butadiene was supplied at 19.7 g / min, styrene was supplied at 4.6 g / min, d-1 as a polymerization initiator was supplied at 0.193 mmol / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.080 mmol / min, additional 1,3-butadiene was supplied at 6.6 g / min, c-1 as a branching agent was supplied at 0.011 mmol / min, a-1 and b-1 as coupling modifiers were supplied at 0.100 mmol / min and 0.003 mmol / min, respectively, and the temperature of the first reactor was 75° C. and the temperature of the second reactor was 80° C. The physical properties of the modified conjugated diene polymer (A14) are shown in Table 3.

[0699] (Example 15) Modified conjugated diene polymer (A15)

[0700] A modified conjugated diene polymer (A15) was obtained in the same manner as in Example 1 except that 1,3-butadiene was supplied at 19.7 g / min, styrene was supplied at 4.6 g / min, d-1 as a polymerization initiator was supplied at 0.193 mmol / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.080 mmol / min, additional 1,3-butadiene was supplied at 6.6 g / min, c-1 as a branching agent was supplied at 0.011 mmol / min, a-1 and b-1 as coupling modifiers were supplied at 0.089 mmol / min and 0.005 mmol / min, respectively, and the temperature of the first reactor was 75° C. and the temperature of the second reactor was 80° C. The physical properties of the modified conjugated diene polymer (A15) are shown in Table 3.

[0701] (Example 16) Modified conjugated diene polymer (A16)

[0702] 1,3-butadiene was supplied at 19.7 g / min, styrene was supplied at 4.6 g / min, d-1 as a polymerization initiator was supplied at 0.193 mmol / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.080 mmol / min, additional 1,3-butadiene was supplied at 6.6 g / min, c-1 as a branching agent was supplied at 0.011 mmol / min, a-1 and b-1 as coupling modifiers were supplied at 0.077 mmol / min and 0.008 mmol / min, respectively, and the temperature of the first reactor was 75° C. and the temperature of the second reactor was 80° C., and a modified conjugated diene polymer (A16) was obtained in the same manner as in Example 1. The physical properties of the modified conjugated diene polymer (A16) are shown in Table 3.

[0703] (Example 17) Modified conjugated diene polymer (A17)

[0704] A modified conjugated diene polymer (A17) was obtained in the same manner as in Example 1 except that 1,3-butadiene was supplied at 19.7 g / min, styrene was supplied at 4.6 g / min, d-1 as a polymerization initiator was supplied at 0.193 mmol / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.080 mmol / min, additional 1,3-butadiene was supplied at 6.6 g / min, c-1 as a branching agent was supplied at 0.011 mmol / min, a-1 and b-1 as coupling modifiers were supplied at 0.066 mmol / min and 0.011 mmol / min, respectively, and the temperature of the first reactor was 75° C. and the temperature of the second reactor was 80° C. The physical properties of the modified conjugated diene polymer (A17) are shown in Table 3.

[0705] (Example 18) Modified conjugated diene polymer (A18)

[0706] A modified conjugated diene polymer (A18) was obtained in the same manner as in Example 1 except that 1,3-butadiene was supplied at 19.7 g / min, styrene was supplied at 4.6 g / min, d-1 as a polymerization initiator was supplied at 0.193 mmol / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.080 mmol / min, additional 1,3-butadiene was supplied at 6.6 g / min, c-1 as a branching agent was supplied at 0.011 mmol / min, a-1 and b-1 as coupling modifiers were supplied at 0.056 mmol / min and 0.014 mmol / min, respectively, and the temperature of the first reactor was 75° C. and the temperature of the second reactor was 80° C. The physical properties of the modified conjugated diene polymer (A18) are shown in Table 3.

[0707] (Example 19) Modified conjugated diene polymer (A19)

[0708] A modified conjugated diene polymer (A19) was obtained in the same manner as in Example 1 except that 20.8 g / min of 1,3-butadiene was supplied, 3.1 g / min of styrene was supplied, 0.193 mmol / min of d-1 as a polymerization initiator, 0.104 mmol / min of 2,2-bis(2-tetrahydrofuryl)propane as a polar compound, 6.9 g / min of additional 1,3-butadiene was supplied, 0.011 mmol / min of c-1 as a branching agent, and 0.100 mmol / min and 0.003 mmol / min of a-1 and b-1 as coupling modifiers, respectively, and the temperature of the first reactor was 68° C. and the temperature of the second reactor was 74° C. The physical properties of the modified conjugated diene polymer (A19) are shown in Table 4.

[0709] (Example 20) Modified conjugated diene polymer (A20)

[0710] A modified conjugated diene polymer (A20) was obtained in the same manner as in Example 1 except that 20.8 g / min of 1,3-butadiene was supplied, 3.1 g / min of styrene was supplied, 0.193 mmol / min of d-1 as a polymerization initiator, 0.104 mmol / min of 2,2-bis(2-tetrahydrofuryl)propane as a polar compound, 6.9 g / min of additional 1,3-butadiene was supplied, 0.011 mmol / min of c-1 as a branching agent, 0.089 mmol / min of a-1 and 0.005 mmol / min of b-1 as coupling modifiers, respectively, and the temperature of the first reactor was 68° C. and the temperature of the second reactor was 74° C. The physical properties of the modified conjugated diene polymer (A20) are shown in Table 4.

[0711] (Example 21) Modified conjugated diene polymer (A21)

[0712] A modified conjugated diene polymer (A21) was obtained in the same manner as in Example 1 except that 20.8 g / min of 1,3-butadiene was supplied, 3.1 g / min of styrene was supplied, 0.193 mmol / min of d-1 as a polymerization initiator, 0.104 mmol / min of 2,2-bis(2-tetrahydrofuryl)propane as a polar compound, 6.9 g / min of additional 1,3-butadiene was supplied, 0.011 mmol / min of c-1 as a branching agent, and 0.077 mmol / min and 0.008 mmol / min of a-1 and b-1 as coupling modifiers, respectively, and the temperature of the first reactor was 68° C. and the temperature of the second reactor was 74° C. The physical properties of the modified conjugated diene polymer (A21) are shown in Table 4.

[0713] (Example 22) Modified conjugated diene polymer (A22)

[0714] A modified conjugated diene polymer (A22) was obtained in the same manner as in Example 1 except that 20.8 g / min of 1,3-butadiene was supplied, 3.1 g / min of styrene was supplied, 0.193 mmol / min of d-1 as a polymerization initiator, 0.104 mmol / min of 2,2-bis(2-tetrahydrofuryl)propane as a polar compound, 6.9 g / min of additional 1,3-butadiene was supplied, 0.011 mmol / min of c-1 as a branching agent, and 0.066 mmol / min and 0.011 mmol / min of a-1 and b-1 as coupling modifiers, respectively, and the temperature of the first reactor was 68° C. and the temperature of the second reactor was 74° C. The physical properties of the modified conjugated diene polymer (A22) are shown in Table 4.

[0715] (Example 23) Modified conjugated diene polymer (A23)

[0716] A modified conjugated diene polymer (A23) was obtained in the same manner as in Example 1 except that 20.8 g / min of 1,3-butadiene was supplied, 3.1 g / min of styrene was supplied, 0.193 mmol / min of d-1 as a polymerization initiator, 0.104 mmol / min of 2,2-bis(2-tetrahydrofuryl)propane as a polar compound, 6.9 g / min of additional 1,3-butadiene was supplied, 0.011 mmol / min of c-1 as a branching agent, and 0.056 mmol / min and 0.014 mmol / min of a-1 and b-1 as coupling modifiers, respectively, and the temperature of the first reactor was 68° C. and the temperature of the second reactor was 74° C. The physical properties of the modified conjugated diene polymer (A23) are shown in Table 4.

[0717] (Example 24) Modified conjugated diene polymer (A24)

[0718] A modified conjugated diene polymer (A24) was obtained in the same manner as in Example 1 except that 1,3-butadiene was supplied at 16.2 g / min, styrene was supplied at 9.2 g / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.045 mmol / min, additional 1,3-butadiene was supplied at 5.4 g / min, c-1 as a branching agent was supplied at 0.011 mmol / min, the temperature of the first reactor was 83° C., and the temperature of the second reactor was 88° C. The physical properties of the modified conjugated diene polymer (A24) are shown in Table 4.

[0719] (Example 25) Modified conjugated diene polymer (A25)

[0720] A modified conjugated diene polymer (A25) was obtained in the same manner as in Example 1 except that 1,3-butadiene was supplied at 16.2 g / min, styrene was supplied at 9.2 g / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.045 mmol / min, additional 1,3-butadiene was supplied at 5.4 g / min, c-1 as a branching agent was supplied at 0.011 mmol / min, a-1 and b-1 as coupling modifiers were supplied at 0.093 mmol / min and 0.006 mmol / min, respectively, and the temperature of the first reactor was 83° C. and the temperature of the second reactor was 88° C. The physical properties of the modified conjugated diene polymer (A25) are shown in Table 5.

[0721] (Example 26) Modified conjugated diene polymer (A26)

[0722] A modified conjugated diene polymer (A26) was obtained in the same manner as in Example 1 except that 1,3-butadiene was supplied at 16.2 g / min, styrene was supplied at 9.2 g / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.045 mmol / min, additional 1,3-butadiene was supplied at 5.4 g / min, c-1 as a branching agent was supplied at 0.011 mmol / min, a-1 and b-1 as coupling modifiers were supplied at 0.081 mmol / min and 0.008 mmol / min, respectively, and the temperature of the first reactor was 83° C. and the temperature of the second reactor was 88° C. The physical properties of the modified conjugated diene polymer (A26) are shown in Table 5.

[0723] (Example 27) Modified conjugated diene polymer (A27)

[0724] A modified conjugated diene polymer (A27) was obtained in the same manner as in Example 1 except that 1,3-butadiene was supplied at 16.2 g / min, styrene was supplied at 9.2 g / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.045 mmol / min, additional 1,3-butadiene was supplied at 5.4 g / min, c-1 as a branching agent was supplied at 0.011 mmol / min, a-1 and b-1 as coupling modifiers were supplied at 0.070 mmol / min and 0.011 mmol / min, respectively, and the temperature of the first reactor was 83° C. and the temperature of the second reactor was 88° C. The physical properties of the modified conjugated diene polymer (A27) are shown in Table 5.

[0725] (Example 28) Modified conjugated diene polymer (A28)

[0726] A modified conjugated diene polymer (A28) was obtained in the same manner as in Example 1 except that 1,3-butadiene was supplied at 16.2 g / min, styrene was supplied at 9.2 g / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.045 mmol / min, additional 1,3-butadiene was supplied at 5.4 g / min, c-1 as a branching agent was supplied at 0.011 mmol / min, a-1 and b-1 as coupling modifiers were supplied at 0.058 mmol / min and 0.014 mmol / min, respectively, and the temperature of the first reactor was 83° C. and the temperature of the second reactor was 88° C. The physical properties of the modified conjugated diene polymer (A28) are shown in Table 5.

[0727] (Example 29) Modified conjugated diene polymer (A29)

[0728] A modified conjugated diene polymer (A29) was obtained in the same manner as in Example 1 except that 1,3-butadiene was supplied at 17.2 g / min, styrene was supplied at 7.9 g / min, d-1 as a polymerization initiator was supplied at 0.197 mmol / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.060 mmol / min, additional 1,3-butadiene was supplied at 5.7 g / min, c-1 as a branching agent was supplied at 0.024 mmol / min, a-1 and b-1 as coupling modifiers were supplied at 0.091 mmol / min and 0.003 mmol / min, respectively, and the temperature of the first reactor was 78° C. and the temperature of the second reactor was 78° C. The physical properties of the modified conjugated diene polymer (A29) are shown in Table 5.

[0729] (Example 30) Modified conjugated diene polymer (A30)

[0730] A modified conjugated diene polymer (A30) was obtained in the same manner as in Example 1 except that 1,3-butadiene was supplied at 17.2 g / min, styrene was supplied at 7.9 g / min, d-1 as a polymerization initiator was supplied at 0.197 mmol / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.060 mmol / min, additional 1,3-butadiene was supplied at 5.7 g / min, c-1 as a branching agent was supplied at 0.024 mmol / min, a-1 and b-1 as coupling modifiers were supplied at 0.082 mmol / min and 0.005 mmol / min, respectively, and the temperature of the first reactor was 78° C. and the temperature of the second reactor was 78° C. The physical properties of the modified conjugated diene polymer (A30) are shown in Table 5.

[0731] (Example 31) Modified conjugated diene polymer (A31)

[0732] A modified conjugated diene polymer (A31) was obtained in the same manner as in Example 1 except that 1,3-butadiene was supplied at 17.2 g / min, styrene was supplied at 7.9 g / min, d-1 as a polymerization initiator was supplied at 0.197 mmol / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.060 mmol / min, additional 1,3-butadiene was supplied at 5.7 g / min, c-1 as a branching agent was supplied at 0.024 mmol / min, a-1 and b-1 as coupling modifiers were supplied at 0.073 mmol / min and 0.008 mmol / min, respectively, and the temperature of the first reactor was 78° C. and the temperature of the second reactor was 78° C. The physical properties of the modified conjugated diene polymer (A31) are shown in Table 6.

[0733] (Example 32) Modified conjugated diene polymer (A32)

[0734] A modified conjugated diene polymer (A32) was obtained in the same manner as in Example 1 except that 1,3-butadiene was supplied at 17.2 g / min, styrene was supplied at 7.9 g / min, d-1 as a polymerization initiator was supplied at 0.197 mmol / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.060 mmol / min, additional 1,3-butadiene was supplied at 5.7 g / min, c-1 as a branching agent was supplied at 0.024 mmol / min, a-1 and b-1 as coupling modifiers were supplied at 0.062 mmol / min and 0.010 mmol / min, respectively, and the temperature of the first reactor was 78° C. and the temperature of the second reactor was 78° C. The physical properties of the modified conjugated diene polymer (A32) are shown in Table 6.

[0735] (Example 33) Modified conjugated diene polymer (A33)

[0736] A modified conjugated diene polymer (A33) was obtained in the same manner as in Example 1 except that 1,3-butadiene was supplied at 17.2 g / min, styrene was supplied at 7.9 g / min, d-1 as a polymerization initiator was supplied at 0.197 mmol / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.060 mmol / min, additional 1,3-butadiene was supplied at 5.7 g / min, c-1 as a branching agent was supplied at 0.024 mmol / min, a-1 and b-1 as coupling modifiers were supplied at 0.051 mmol / min and 0.013 mmol / min, respectively, and the temperature of the first reactor was 78° C. and the temperature of the second reactor was 78° C. The physical properties of the modified conjugated diene polymer (A33) are shown in Table 6.

[0737] (Example 34) Modified conjugated diene polymer (A34)

[0738] A modified conjugated diene polymer (A34) was obtained in the same manner as in Example 1 except that 20.8 g / min of 1,3-butadiene was supplied, 3.1 g / min of styrene was supplied, 0.207 mmol / min of d-1 as a polymerization initiator, 0.032 mmol / min of 2,2-bis(2-tetrahydrofuryl)propane as a polar compound, 6.9 g / min of additional 1,3-butadiene was supplied, 0.011 mmol / min of c-1 as a branching agent, and 0.105 mmol / min and 0.003 mmol / min of a-1 and b-1 as coupling modifiers, respectively, and the temperature of the first reactor was 82° C. and the temperature of the second reactor was 86° C. The physical properties of the modified conjugated diene polymer (A34) are shown in Table 6.

[0739] (Example 35) Modified conjugated diene polymer (A35)

[0740] A modified conjugated diene polymer (A35) was obtained in the same manner as in Example 1 except that 20.8 g / min of 1,3-butadiene was supplied, 3.1 g / min of styrene was supplied, 0.207 mmol / min of d-1 as a polymerization initiator, 0.032 mmol / min of 2,2-bis(2-tetrahydrofuryl)propane as a polar compound, 6.9 g / min of additional 1,3-butadiene was supplied, 0.011 mmol / min of c-1 as a branching agent, and 0.094 mmol / min and 0.006 mmol / min of a-1 and b-1 as coupling modifiers, respectively, and the temperature of the first reactor was 82° C. and the temperature of the second reactor was 86° C. The physical properties of the modified conjugated diene polymer (A35) are shown in Table 6.

[0741] (Example 36) Modified conjugated diene polymer (A36)

[0742] A modified conjugated diene polymer (A36) was obtained in the same manner as in Example 1 except that 20.8 g / min of 1,3-butadiene was supplied, 3.1 g / min of styrene was supplied, 0.207 mmol / min of d-1 as a polymerization initiator, 0.032 mmol / min of 2,2-bis(2-tetrahydrofuryl)propane as a polar compound, 6.9 g / min of additional 1,3-butadiene was supplied, 0.011 mmol / min of c-1 as a branching agent, and 0.083 mmol / min and 0.009 mmol / min of a-1 and b-1 as coupling modifiers, respectively, and the temperature of the first reactor was 82° C. and the temperature of the second reactor was 86° C. The physical properties of the modified conjugated diene polymer (A36) are shown in Table 6.

[0743] (Example 37) Modified conjugated diene polymer (A37)

[0744] A modified conjugated diene polymer (A37) was obtained in the same manner as in Example 1 except that 20.8 g / min of 1,3-butadiene was supplied, 3.1 g / min of styrene was supplied, 0.207 mmol / min of d-1 as a polymerization initiator, 0.032 mmol / min of 2,2-bis(2-tetrahydrofuryl)propane as a polar compound, 6.9 g / min of additional 1,3-butadiene was supplied, 0.011 mmol / min of c-1 as a branching agent, and 0.070 mmol / min and 0.012 mmol / min of a-1 and b-1 as coupling modifiers, respectively, and the temperature of the first reactor was 82° C. and the temperature of the second reactor was 86° C. The physical properties of the modified conjugated diene polymer (A37) are shown in Table 7.

[0745] (Example 38) Modified conjugated diene polymer (A38)

[0746] A modified conjugated diene polymer (A38) was obtained in the same manner as in Example 1 except that 20.8 g / min of 1,3-butadiene was supplied, 3.1 g / min of styrene was supplied, 0.207 mmol / min of d-1 as a polymerization initiator, 0.032 mmol / min of 2,2-bis(2-tetrahydrofuryl)propane as a polar compound, 6.9 g / min of additional 1,3-butadiene was supplied, 0.011 mmol / min of c-1 as a branching agent, and 0.058 mmol / min and 0.014 mmol / min of a-1 and b-1 as coupling modifiers, respectively, and the temperature of the first reactor was 82° C. and the temperature of the second reactor was 86° C. The physical properties of the modified conjugated diene polymer (A38) are shown in Table 7.

[0747] (Example 39) Modified conjugated diene polymer (A39)

[0748] A modified conjugated diene polymer (A39) was obtained in the same manner as in Example 1 except that d-1 as a polymerization initiator was supplied at 0.207 mmol / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.028 mmol / min, c-1 as a branching agent was supplied at 0.011 mmol / min, a-1 and b-1 as coupling modifiers were supplied at 0.105 mmol / min and 0.003 mmol / min, respectively, and the temperature of the first reactor was 83° C. and the temperature of the second reactor was 88° C. The physical properties of the modified conjugated diene polymer (A39) are shown in Table 7.

[0749] (Example 40) Modified conjugated diene polymer (A40)

[0750] A modified conjugated diene polymer (A40) was obtained in the same manner as in Example 1 except that d-1 as a polymerization initiator was supplied at 0.207 mmol / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.028 mmol / min, c-1 as a branching agent was supplied at 0.011 mmol / min, a-1 and b-1 as coupling modifiers were supplied at 0.093 mmol / min and 0.006 mmol / min, respectively, and the temperature of the first reactor was 83° C. and the temperature of the second reactor was 88° C. The physical properties of the modified conjugated diene polymer (A40) are shown in Table 7.

[0751] (Example 41) Modified conjugated diene polymer (A41)

[0752] A modified conjugated diene polymer (A41) was obtained in the same manner as in Example 1 except that d-1 as a polymerization initiator was supplied at 0.207 mmol / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.028 mmol / min, c-1 as a branching agent was supplied at 0.011 mmol / min, a-1 and b-1 as coupling modifiers were supplied at 0.081 mmol / min and 0.009 mmol / min, respectively, and the temperature of the first reactor was 83° C. and the temperature of the second reactor was 88° C. The physical properties of the modified conjugated diene polymer (A41) are shown in Table 7.

[0753] (Example 42) Modified conjugated diene polymer (A42)

[0754] A modified conjugated diene polymer (A42) was obtained in the same manner as in Example 1 except that d-1 as a polymerization initiator was supplied at 0.207 mmol / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.028 mmol / min, c-1 as a branching agent was supplied at 0.011 mmol / min, a-1 and b-1 as coupling modifiers were supplied at 0.070 mmol / min and 0.012 mmol / min, respectively, and the temperature of the first reactor was 83° C. and the temperature of the second reactor was 88° C. The physical properties of the modified conjugated diene polymer (A42) are shown in Table 7.

[0755] (Example 43) Modified conjugated diene polymer (A43)

[0756] A modified conjugated diene polymer (A43) was obtained in the same manner as in Example 1 except that d-1 as a polymerization initiator was supplied at 0.207 mmol / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.028 mmol / min, c-1 as a branching agent was supplied at 0.011 mmol / min, a-1 and b-1 as coupling modifiers were supplied at 0.060 mmol / min and 0.014 mmol / min, respectively, and the temperature of the first reactor was 83° C. and the temperature of the second reactor was 88° C. The physical properties of the modified conjugated diene polymer (A43) are shown in Table 8.

[0757] (Example 44) Modified conjugated diene polymer (A44)

[0758] A modified conjugated diene polymer (A44) was obtained in the same manner as in Example 1 except that 15.0 g / min of 1,3-butadiene was supplied, 10.8 g / min of styrene was supplied, 0.193 mmol / min of d-1 as a polymerization initiator, 0.092 mmol / min of 2,2-bis(2-tetrahydrofuryl)propane as a polar compound, 5.0 g / min of additional 1,3-butadiene was supplied, 0.011 mmol / min of c-1 as a branching agent, and 0.077 mmol / min and 0.008 mmol / min of a-1 and b-1 as coupling modifiers, respectively, and the temperature of the first reactor was 68° C. and the temperature of the second reactor was 74° C. The physical properties of the modified conjugated diene polymer (A44) are shown in Table 8.

[0759] (Example 45) Modified conjugated diene polymer (A45)

[0760] A modified conjugated diene polymer (A45) was obtained in the same manner as in Example 1 except that 14.3 g / min of 1,3-butadiene was supplied, 11.7 g / min of styrene was supplied, 0.193 mmol / min of d-1 as a polymerization initiator, 0.100 mmol / min of 2,2-bis(2-tetrahydrofuryl)propane as a polar compound, 4.8 g / min of additional 1,3-butadiene was supplied, 0.011 mmol / min of c-1 as a branching agent, and 0.077 mmol / min and 0.008 mmol / min of a-1 and b-1 as coupling modifiers, respectively, and the temperature of the first reactor was 82° C. and the temperature of the second reactor was 82° C. The physical properties of the modified conjugated diene polymer (A45) are shown in Table 8.

[0761] (Example 46) Modified conjugated diene polymer (A46)

[0762] A modified conjugated diene polymer (A46) was obtained in the same manner as in Example 1 except that 13.9 g / min of 1,3-butadiene was supplied, 12.3 g / min of styrene was supplied, 0.193 mmol / min of d-1 as a polymerization initiator, 0.092 mmol / min of 2,2-bis(2-tetrahydrofuryl)propane as a polar compound, 4.6 g / min of additional 1,3-butadiene was supplied, 0.011 mmol / min of c-1 as a branching agent, 0.077 mmol / min of a-1 and 0.008 mmol / min of b-1 as coupling modifiers, respectively, and the temperature of the first reactor was 68° C. and the temperature of the second reactor was 74° C. The physical properties of the modified conjugated diene polymer (A46) are shown in Table 8.

[0763] (Example 47) Modified conjugated diene polymer (A47)

[0764] A modified conjugated diene polymer (A47) was obtained in the same manner as in Example 1 except that 24.1 g / min of 1,3-butadiene was supplied, 0 g / min of styrene, 134.7 g / min of n-hexane, 0.076 mmol / min of n-butyllithium for impurity treatment, 0.245 mmol / min of d-1 as a polymerization initiator, 0.009 mmol / min of 2,2-bis(2-tetrahydrofuryl)propane as a polar compound, 0 g / min of additional 1,3-butadiene, 0.014 mmol / min of c-1 as a branching agent, and 0.094 mmol / min and 0.010 mmol / min of a-1 and b-1 as coupling modifiers, respectively, were supplied, and the temperature of the first reactor was 76° C. and the temperature of the second reactor was 76° C. Table 8 shows the physical properties of the modified conjugated diene polymer (A47).

[0765] (Example 48) Modified conjugated diene polymer (A48)

[0766] A modified conjugated diene polymer (A48) was obtained in the same manner as in Example 1 except that d-1 as a polymerization initiator was supplied at 0.193 mmol / min, c-1 as a branching agent was supplied at 0.011 mmol / min, trimethoxy(propyl)silane (referred to as "a-2" in Table 1) was supplied at 0.077 mmol / min as a coupling modifier, and 1,6-bis(trimethoxysilyl)hexane (referred to as "b-3" in Table 1) was supplied at 0.016 mmol / min. The physical properties of the modified conjugated diene polymer (A48) are shown in Table 8.

[0767] (Example 49) Modified conjugated diene polymer (A49)

[0768] A modified conjugated diene polymer (A49) was obtained in the same manner as in Example 1 except that d-1 as a polymerization initiator was supplied at 0.193 mmol / min, c-1 as a branching agent was supplied at 0.011 mmol / min, N-benzylidene-3-(trimethoxysilyl)propane-1-amine (referred to as "a-3" in Table 1) was supplied at 0.052 mmol / min as a coupling modifier, and b-1 was supplied at 0.008 mmol / min. The physical properties of the modified conjugated diene polymer (A49) are shown in Table 9.

[0769] (Example 50) Modified conjugated diene polymer (A50)

[0770] The two connected tank-type pressure vessels were changed to containers with an internal volume of 15 L and a ratio (L / D) of the internal height (L) to the diameter (D) of 6.0, d-1 as a polymerization initiator was supplied at 0.193 mmol / min, n-hexane was supplied at 91.0 mmol / min, a-1 and b-1 as coupling modifiers were supplied at 0.089 mmol / min and 0.005 mmol / min, respectively, and the temperature of the first reactor was 68° C. and the temperature of the second reactor was 86° C., and a modified conjugated diene polymer (A50) was obtained in the same manner as in Example 1. The physical properties of the modified conjugated diene polymer (A50) are shown in Table 9.

[0771] (Example 51) Modified conjugated diene polymer (A51)

[0772] A modified conjugated diene polymer (A51) was obtained in the same manner as in Example 1 except that 1,3-butadiene was supplied at 22.0 g / min, styrene was supplied at 1.5 g / min, d-1 as a polymerization initiator was supplied at 0.212 mmol / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.054 mmol / min, additional 1,3-butadiene was supplied at 7.3 g / min, c-1 as a branching agent was supplied at 0.012 mmol / min, and a-1 and b-1 as coupling modifiers were supplied at 0.084 mmol / min and 0.009 mmol / min, respectively. The physical properties of the modified conjugated diene polymer (A51) are shown in Table 9.

[0773] (Example 52) Modified conjugated diene polymer (A52)

[0774] A modified conjugated diene polymer (A52) was obtained in the same manner as in Example 1 except that 1,3-butadiene was supplied at 22.0 g / min, styrene was supplied at 1.5 g / min, d-1 as a polymerization initiator was supplied at 0.212 mmol / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.043 mmol / min, additional 1,3-butadiene was supplied at 7.3 g / min, c-1 as a branching agent was supplied at 0.012 mmol / min, and a-1 and b-1 as coupling modifiers were supplied at 0.084 mmol / min and 0.009 mmol / min, respectively. The physical properties of the modified conjugated diene polymer (A52) are shown in Table 9.

[0775] (Example 53) Modified conjugated diene polymer (A53)

[0776] 1,3-butadiene was supplied at 20.8 g / min, styrene was supplied at 3.1 g / min, a mixed solution of piperidyl lithium (also called "1-lithiopiperidine") and n-butyl lithium prepared as a polymerization initiator (the molar ratio of piperidyl lithium to n-butyl lithium was 0.75:0.25, abbreviated as "d-2" in the table) was supplied at 0.193 mmol / min, and 2,2-bis(2-tetrahydrofuranyl)propane as a polar compound was supplied at 0.054 mmol / min. / min, additional 1,3-butadiene was supplied at 6.9 g / min, c-1 as a branching agent was supplied at 0.011 mmol / min, a-1 and b-1 as coupling modifiers were supplied at 0.077 mmol / min and 0.008 mmol / min, respectively, and the temperature of the first reactor was 56° C. and the temperature of the second reactor was 66° C., and a modified conjugated diene polymer (A53) was obtained in the same manner as in Example 1. The physical properties of the modified conjugated diene polymer (A53) are shown in Table 9.

[0777] (Comparative Example 1) Modified conjugated diene polymer (B1)

[0778] Two tank-type pressure vessels equipped with a stirrer and a jacket for temperature control were connected as polymerization branch reactors. The tank-type pressure vessel had an internal volume of 10 L, a ratio (L / D) of internal height (L) to diameter (D) of 4.0, an inlet at the bottom, and an outlet at the top.

[0779] 1,3-butadiene, styrene and n-hexane from which water had been removed in advance were mixed at 18.5 g / min, 6.2 g / min and 138.9 g / min, respectively, and continuously supplied to the bottom of the first reactor. It should be noted that, during the above supply, n-butyl lithium for inertizing residual impurities was mixed at 0.096 mmol / min using a static mixer and continuously added just before the mixed solution was added to the first reactor. In addition, while supplying 1,3-butadiene, styrene, n-hexane and n-butyl lithium, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound and n-butyl lithium as a polymerization initiator were supplied to the bottom of the first reactor at 0.049 mmol / min and 0.193 mmol / min, respectively, while the reaction solution was vigorously stirred with a stirrer. It should be noted that the temperature in the first reactor was maintained at 82°C.

[0780] The conjugated diene polymer solution produced by the polymerization reaction in the first reactor was continuously extracted from the top of the first reactor and continuously supplied to the bottom of the second reactor. When the polymerization was sufficiently stable, trimethoxy(4-vinylphenyl)silane (indicated as "c-1" in Table 10) as a branching agent was supplied from the bottom of the second reactor at a rate of 0.011 mmol / min while copolymerizing 1,3-butadiene and styrene, and additional 1,3-butadiene was further added at a rate of 6.2 g / min to perform a polymerization branching step.

[0781] It should be noted that the temperature in the second reactor was maintained at 86° C. The conjugated diene polymer solution was withdrawn in small amounts from the outlet of the second reactor, an antioxidant (BHT) was added in an amount of 0.2 g per 100 g of the conjugated diene polymer, and then the solvent was removed. For the obtained conjugated diene polymer, various molecular weights measured by GPC, as well as the Mooney viscosity and Mooney stress relaxation rate at 110° C. were measured.

[0782] The physical properties are shown in Table 10 (physical properties 1-1, 1-2, 1-3, physical properties 2, physical properties 3).

[0783] Next, the conjugated diene polymer solution flowing out from the top of the second reactor is supplied to the static mixer. Further, b-1 as a coupling modifier is continuously added to the conjugated diene polymer solution continuously flowing into the static mixer at a condition of 0.028 mmol / min, thereby coupling the conjugated diene polymer. At this time, the time until the coupling modifier is added to the polymer solution flowing out from the outlet of the second reactor is 4.8 minutes, and the temperature of the polymer solution when the coupling modifier is added is 68°C. In addition, the difference between the temperature of the polymer solution at the outlet of the second reactor and the temperature of the polymer solution when the coupling modifier is added is 2°C.

[0784] Then, the n-hexane solution of antioxidant (BHT) was continuously added to the polymer solution flowing out from the static mixer under the condition of 0.055g / min in the mode of 0.2g of antioxidant (BHT) per 100g of polymer to terminate the coupling reaction. The solvent was removed by steam stripping and formed into a compact, thereby obtaining a modified conjugated diene polymer (B1). Various physical properties of the obtained modified conjugated diene polymer (B1) were measured. The measurement results are shown in Table 10.

[0785] (Comparative Example 2) Modified conjugated diene polymer (B2)

[0786] A modified conjugated diene polymer (B2) was obtained in the same manner as in Comparative Example 1 except that n-hexane was supplied at 117.4 mmol / min, c-1 as a branching agent was not added, and a-1 and b-1 as coupling modifiers were supplied at 0.077 mmol / min and 0.008 mmol / min, respectively. The physical properties of the modified conjugated diene polymer (B2) are shown in Table 10.

[0787] (Comparative Example 3) Modified conjugated diene polymer (B3)

[0788] A modified conjugated diene polymer (B3) was obtained in the same manner as in Comparative Example 1 except that n-butyl lithium as a polymerization initiator was supplied at 0.144 mmol / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.038 mmol / min, c-1 as a branching agent was supplied at 0.009 mmol / min, and a-1 and b-1 as coupling modifiers were supplied at 0.061 mmol / min and 0.006 mmol / min, respectively. The physical properties of the modified conjugated diene polymer (B3) are shown in Table 10.

[0789] (Comparative Example 4) Modified conjugated diene polymer (B4)

[0790] A modified conjugated diene polymer (B4) was obtained in the same manner as in Comparative Example 1 except that n-butyl lithium as a polymerization initiator was supplied at 0.221 mmol / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.054 mmol / min, c-1 as a branching agent was supplied at 0.025 mmol / min, and a-1 and b-1 as coupling modifiers were supplied at 0.032 mmol / min and 0.019 mmol / min, respectively. The physical properties of the modified conjugated diene polymer (B4) are shown in Table 10.

[0791] (Comparative Example 5) Modified conjugated diene polymer (B5)

[0792] A modified conjugated diene polymer (B5) was obtained in the same manner as in Comparative Example 1 except that 1,3-butadiene was supplied at 16.2 g / min, styrene was supplied at 9.2 g / min, n-butyl lithium as a polymerization initiator was supplied at 0.202 mmol / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.045 mmol / min, additional 1,3-butadiene was supplied at 5.4 g / min, a-1 as a coupling modifier was not added, and b-1 was supplied at 0.028 mmol / min. The physical properties of the modified conjugated diene polymer (B5) are shown in Table 10.

[0793] (Comparative Example 6) Modified conjugated diene polymer (B6)

[0794] A modified conjugated diene polymer (B6) was obtained in the same manner as in Comparative Example 1 except that 1,3-butadiene was supplied at 15.0 g / min, styrene was supplied at 10.8 g / min, 2,2-bis(2-tetrahydrofuryl)propane as a polar compound was supplied at 0.092 mmol / min, additional 1,3-butadiene was supplied at 5.0 g / min, a-1 as a coupling modifier was not added, and b-1 was supplied at 0.028 mmol / min. The physical properties of the modified conjugated diene polymer (B6) are shown in Table 10.

[0795]

[0796]

[0797]

[0798]

[0799]

[0800]

[0801]

[0802]

[0803]

[0804]

[0805] [Evaluation of compacts of modified conjugated diene polymers]

[0806] (Evaluation 1) Appearance of the briquette (whether there is crack or damage)

[0807] The compacts of the modified conjugated diene polymers produced by the methods shown in the Examples and Comparative Examples were visually observed for the presence or absence of external cracks, breakage, etc., and evaluated by each evaluator based on the following criteria, with 4 points as the full score. The appearance of the compact is an indicator of the compact moldability of the modified conjugated diene polymer.

[0808] IV: The particles failed to aggregate and could not be formed into compacts.

[0809] III: Although capable of being molded into a compact, breakage was observed over time.

[0810] II: Cracks, breakages, etc. were observed in 5% or less of the compact surface.

[0811] I: No cracks, damage, etc. were observed on the surface of the compact.

[0812] [Preparation and Evaluation of Rubber Compositions]

[0813] (Evaluation of Rubber Composition)

[0814] Using the modified conjugated diene polymers A1 to A53 and B1 to B6 shown in Tables 1 to 10 as raw materials, rubber compositions were obtained in the following blending ratios.

[0815] Modified conjugated diene polymer (any one of A1 to A53, B1 to B6): 70 parts by mass (oil-free)

[0816] Butadiene rubber (trade name "BR150" manufactured by Ube Industries, Ltd.): 30 parts by mass

[0817] Silicon oxide (trade name "Ultrasil 7000GR" manufactured by Evonik Degussa, nitrogen adsorption specific surface area 170m 2 / g): 75.0 parts by mass

[0818] Carbon black (trade name "SEAST KH (N339)" manufactured by Tokai Tanso Co., Ltd.): 5.0 parts by mass

[0819] Silane coupling agent (trade name "Si75" manufactured by Evonik Degussa, bis(triethoxysilylpropyl) disulfide): 6.0 parts by mass

[0820] S-RAE oil (trade name "Process NC140" manufactured by JX Nippon Mining and Petrochemical Corporation): 32.0 parts by mass

[0821] Zinc white: 2.5 parts by mass

[0822] Stearic acid: 2.0 parts by mass

[0823] Anti-aging agent (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine): 2.0 parts by mass

[0824] Sulfur: 1.7 parts by mass

[0825] Vulcanization accelerator 1 (N-cyclohexyl-2-benzothiazolylsulfenamide): 1.7 parts by mass

[0826] Vulcanization accelerator 2 (diphenylguanidine): 2.0 parts by mass

[0827] Specifically, the above materials are kneaded by the following method to obtain a rubber composition. A closed mixer (content 0.5L) equipped with a temperature control device is used as the first stage of kneading to knead a modified conjugated diene polymer (any one of A1 to A53 or B1 to B6), butadiene rubber, filler (silicon oxide, carbon black), silane coupling agent, S-RAE oil, zinc white and stearic acid at a filling rate of 65% and a rotor speed of 30 to 50 rpm. At this time, the temperature of the closed mixer is controlled to obtain each rubber composition (mixed product) in a manner such that the discharge temperature is 155 to 160°C.

[0828] Next, as the second stage of mixing, the above-obtained mixture was cooled to room temperature, an anti-aging agent was added, and in order to improve the dispersion of silicon oxide, mixing was performed again under the same conditions as the first stage of mixing. In this case, the discharge temperature of the mixture was also adjusted to 155-160°C by temperature control of the mixer. After cooling, as the third stage of mixing, sulfur and vulcanization accelerators 1 and 2 were added to an open mill set at 70°C for mixing. Thereafter, molding was performed and vulcanization was performed at 160°C for 20 minutes using a vulcanization press. The rubber composition before vulcanization and the rubber composition after vulcanization were evaluated.

[0829] Specifically, the evaluation was performed by the following method. The evaluation results are shown in Tables 11 to 20.

[0830] (Evaluation 2) Emission aggregation

[0831] The unvulcanized modified conjugated diene polymers produced by the methods shown in the Examples and Comparative Examples were visually observed for aggregation (shape) immediately after being discharged from the pressure kneader (immediately after the kneading by the pressure kneader in the first stage of kneading was completed and discharged), and evaluated based on the following criteria for each evaluator, with 4 points as the full score. Aggregation is an indicator of the processability of the sulfide.

[0832] IV: Less than 60% of the end portion of the sheet is smooth, and the processability is very poor.

[0833] III: More than 60% and 80% or less of the end portion of the sheet is smooth, and the processability is poor.

[0834] II: More than 80% and 90% or less of the end portion of the sheet is smooth, and the processability is excellent.

[0835] I: More than 90% of the end portion of the sheet is smooth, and the processability is very excellent.

[0836] (Evaluation 3, 4) Viscoelastic parameters (fuel efficiency and wet grip)

[0837] Viscoelastic parameters were measured in a torsional vibration mode using a viscoelasticity tester "ARES" manufactured by Rheometric Scientific Co., Ltd. The result for the rubber composition of Comparative Example 1 was set to 100, and each measured value was indexed.

[0838] Here, tanδ measured under the conditions of 50°C, frequency 10 Hz, and strain 3% was used as an index of low hysteresis loss, that is, fuel efficiency, and the result of Comparative Example 1 was normalized as 100. A larger index indicates better fuel efficiency, and a value exceeding 65 is evaluated as excellent fuel efficiency.

[0839] Tan δ measured at 0°C, 10 Hz frequency, and 1% strain was used as an index of wet grip performance, and the result of Comparative Example 1 was normalized to 100. A larger index indicates better wet grip performance, and a value exceeding 65 is evaluated as excellent wet grip performance.

[0840] (Evaluation 5, 6) Tensile strength and elongation at break

[0841] The tensile strength and elongation at break were measured according to the tensile test method of JIS K6251. The result of Comparative Example 1 was set to 100, and each measured value was standardized. The larger the value, the better the tensile strength and elongation at break, and the better the destructive characteristics.

[0842] (Evaluation 7) Wear resistance

[0843] The Akron wear tester (manufactured by Yasuda Seiki Co., Ltd.) was used to measure the wear amount after 1000 revolutions at a load of 44.4 N according to JIS K6264-2. The result of Comparative Example 1 was set to 100, and each measured value was standardized. The larger the value, the better the wear resistance, and the case where the value exceeded 80 was evaluated as excellent wear resistance.

[0844]

[0845]

[0846]

[0847]

[0848]

[0849] It is found that the conjugated diene polymer of the present invention is excellent in block moldability, and its sulfide is excellent in performance balance among wear resistance, fracture characteristics and low hysteresis loss.

[0850] This application is based on the Japanese patent application (Japanese Patent Application No. 2022-128615) filed with the Japan Patent Office on August 12, 2022, and its contents are incorporated into this specification as a reference.

[0851] Industrial Applicability

[0852] The conjugated diene polymer and rubber composition of the present invention have excellent moldability and processability, and their vulcanizates have an excellent balance of performance in terms of wear resistance, fracture characteristics, fuel efficiency and low hysteresis loss. Therefore, they have industrial applicability in applications such as tires, resin modification, automotive interior and exterior accessories, anti-vibration rubber and footwear.

Claims

1. A conjugated diene polymer, which satisfies the following <condition (i)> to <condition (iii)>, <Condition(i)> The Mooney viscosity measured at 100°C is 80 or more and 170 or less. <Condition (ii)> The Mooney stress relaxation ratio (MSR) measured at 100°C is 0.30 or more and 0.80 or less, <Condition (iii)> According to the GPC-light scattering method with a viscosity detector, the branching degree distribution curve showing the relationship between the absolute molecular weight and the branching degree (Bn) has an extreme value that is convex downward.

2. The conjugated diene polymer according to claim 1, wherein The glass transition temperature is -90℃~-40℃, Taking the height Hi of the peak top in the absolute molecular weight distribution curve measured by GPC-light scattering method with a viscosity detector as a reference, wherein when there are a plurality of peak tops in the absolute molecular weight distribution curve, the height Hi of the peak top with the largest absolute molecular weight is taken as a reference, the degree of branching of the conjugated diene polymer at the highest absolute molecular weight Mw(high) among at least two absolute molecular weights when the height in the absolute molecular weight distribution curve is 1 / 2 of Hi (1 / 2Hi) is set as Bn(high), the degree of branching of the conjugated diene polymer at the lowest absolute molecular weight Mw(low) is set as Bn(low), and the degree of branching of the conjugated diene polymer at the peak top of the absolute molecular weight distribution curve is set as Bn(top), the following conditions (I) to (III) are satisfied, <Condition(I)> (Bn(high))-(Bn(top))≧1.0 <Condition (II)> (Bn(low))-(Bn(top))≧0.5 <Condition (III)> (Bn(high)) / (Bn(low))=1.1~2.

0.

3. The conjugated diene polymer according to claim 2, wherein The extreme value of the branching degree distribution curve is located at an absolute molecular weight between the Mw(low) and the Mw(high).

4. The conjugated diene polymer according to claim 1, wherein The molecular weight distribution (PDI; MWD) is 1.4 to 3.

5.

5. The conjugated diene polymer according to claim 1, wherein In the branching degree distribution curve, the branching degree at the extreme value is 3.0 or more and 8.0 or less.

6. The conjugated diene polymer according to claim 1, wherein The modification rate is 60% by mass or more.

7. The conjugated diene polymer according to claim 1, comprising: A fork-shaped portion [A] having a plurality of conjugated diene polymer chains bonded to one end of a main chain branch structure portion and a single chain of another conjugated diene polymer bonded to the other end of the main chain branch structure portion; and A conjugated diene polymer having a three-branched or more star-shaped polymer structure [B] to which one or more fork-shaped parts [A] are bonded.

8. The conjugated diene polymer according to claim 1, comprising: A conjugated diene polymer having a fork-shaped portion [A] in which a plurality of conjugated diene polymer chains are bonded to one end of a main chain branch structure portion and a single chain of another conjugated diene polymer is bonded to the other end of the main chain branch structure portion; and A conjugated diene polymer having a three-branched or more star-shaped polymer structure [B] to which one or more fork-shaped parts [A] are bonded.

9. A shaped body comprising: 100 parts by mass of the conjugated diene polymer according to any one of claims 1 to 8; and Less than 1 part by mass of softener component.

10. A method for producing a conjugated diene polymer, which is the method for producing a conjugated diene polymer according to any one of claims 1 to 8, wherein: The manufacturing method has the following steps: A step of polymerizing at least a conjugated diene compound using an organic lithium compound as a polymerization initiator; A step of adding a branching agent; and A step of adding two or more coupling modifiers having different coupling numbers.

11. The method for producing a conjugated diene polymer according to claim 10, wherein: The two or more coupling modifiers include: A coupling modifier having 2 or less alkoxysilyl groups, and A coupling modifier comprising greater than 2 alkoxysilyl groups.

12. A rubber composition comprising: 100 parts by mass of a rubber component; and 5.0 parts by mass or more and 150 parts by mass or less of a filler, The rubber component contains 10 parts by mass or more of the conjugated diene polymer according to any one of claims 1 to 8, based on 100 parts by mass of the total amount of the rubber component.

13. A tire comprising the rubber composition according to claim 12.

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