Modified conjugated diene polymer, briquette, method for producing modified conjugated diene polymer, rubber composition, and tire

Abstract

The present invention provides a modified conjugated diene polymer which satisfies the following lt; condition (i) gt; -lt; condition (vi) gt; . Lt; condition (i) gt; and the Mooney viscosity measured at 100 DEG C is from 100 to 180 (inclusive). Lt; condition (ii) gt; and the Mooney stress relaxation rate measured at 100 DEG C is in the range of 0.10-0.40. Lt; condition (iii) gt; and the glass transition temperature is-95 DEG C to-45 DEG C. Lt; condition (iv) gt; the content of silicon atoms is 100 ppm by mass or more with respect to the total amount of the modified conjugated diene polymer. Lt; condition (V) gt; the content of nitrogen atoms is 50 ppm by mass or more with respect to the total amount of the modified conjugated diene polymer. Lt; condition (VI) gt; the content of the antioxidant is 0.5 parts by mass or less with respect to 100 parts by mass of the modified conjugated diene polymer.

Description

Technical Field

[0001] This invention relates to modified conjugated diene polymers, briquettes, methods for manufacturing modified conjugated diene polymers, rubber compositions, and tires. Background Technology

[0002] In recent years, the demand for lower fuel consumption in automobiles has increased, requiring improvements to the rubber materials used in tires, especially those in contact with the road surface. Driven by stricter fuel consumption regulations, and with the aim of lightweighting automobiles, there is a growing need for resin-based automotive components and thinner-walled tires.

[0003] Materials that address the above requirements include rubber, as well as reinforcing fillers such as carbon black and silicon dioxide.

[0004] For example, by using materials containing silica, it is possible to achieve a balance between low hysteresis loss and improved anti-slip properties. Further attempts have been made to improve the dispersibility of silica in the material by introducing functional groups with affinity or reactivity to silica at the molecular ends of highly mobile rubber molecules, thereby reducing the mobility at the ends of rubber molecules and lowering hysteresis loss through binding with silica particles. In particular, attempts have been made to further reduce hysteresis by introducing modified groups at both ends of the polymer chain. Furthermore, efforts have been made to increase the molecular weight of modified conjugated diene polymers in order to improve breaking strength and abrasion resistance.

[0005] However, high molecular weight modified conjugated diene polymers have the following problems: polymer particles are easy to peel off from the surface of the briquettes themselves, causing the area around the molding machine or the conveyor around the briquettes after molding to be contaminated by polymer particles, and there is room for improvement in terms of the working environment.

[0006] In addition, by introducing modifying groups at both ends of the polymer chain, the nitrogen content in the modified conjugated diene polymer increases, which reduces thermal stability and requires the addition of a large amount of antioxidants. From the perspective of reducing product costs and environmental impact, there is room to reduce the amount used.

[0007] As a method to suppress the peeling of such high molecular weight modified conjugated diene polymers from the surface of the briquettes, the addition of processing oil can be cited.

[0008] For example, Patent Document 1 discloses a method for producing an oil-extended conjugated diene polymer by adding processing oil to a solution of a conjugated diene polymer, thereby suppressing the peeling of polymer particles from the surface of the briquettes.

[0009] In addition, patent documents 2 and 3 propose polymers that are functionalized by reacting cyclic azirmonicyclic compounds with the active ends of polymers.

[0010] Furthermore, patent documents 4 and 5 propose diene-based rubbers obtained by coupling polymer active ends with multifunctional silane compounds.

[0011] Existing technical documents

[0012] Patent documents

[0013] Patent Document 1: Japanese Patent Application Publication No. 2019-131810

[0014] Patent Document 2: Japanese Patent Application Publication No. 2005-290355

[0015] Patent Document 3: Japanese Patent Application Publication No. 11-189616

[0016] Patent Document 4: International Publication No. 07 / 114203

[0017] Patent Document 5: Japanese Patent Application 2018-534375 Summary of the Invention

[0018] The problem that the invention aims to solve

[0019] Previously, modified conjugated diene polymers were typically oil-extended modified conjugated diene polymers containing processing oils, aimed at improving briquetting properties and processability after mixing. However, in recent years, with the goal of increasing the degree of freedom in compounding rubber compositions, there is a desire to minimize the amount of processing oil added to conjugated diene polymers.

[0020] However, in the case of the conjugated diene polymer briquettes disclosed in Patent Document 1, there is a problem that if the amount of processing oil added is reduced, sufficient formability may not be obtained.

[0021] For example, when increasing the molecular weight of modified conjugated diene polymers to improve wear resistance, or setting the glass transition temperature of modified conjugated diene polymers to improve hysteresis loss, polymer particles are prone to detaching from the briquette surface if the amount of processing oil added is low or absent. Furthermore, increasing the nitrogen content tends to deteriorate thermal stability, requiring an increase in the amount of antioxidant added when manufacturing the briquette.

[0022] Methods for solving problems

[0023] In order to solve the above-mentioned problems, the inventors conducted in-depth research and found that modified conjugated diene polymers with specified Mooney viscosity and Mooney stress relaxation rate (MSR), glass transition temperature within a specified range, and specified silicon and nitrogen atom contents can be molded into compressed blocks while suppressing the content of antioxidants, thereby solving the above-mentioned problems and completing the present invention.

[0024] That is, the present invention is as follows.

[0025] [1] A modified conjugated diene polymer that satisfies the following conditions (i) to (vi).

[0026] <Condition (i)>

[0027] The Mooney viscosity, measured at 100°C, is between 100 and 180.

[0028] <Condition(ii)>

[0029] The Mooney stress relaxation rate, measured at 100°C, ranged from 0.10 to 0.40.

[0030] <Condition (iii)>

[0031] The glass transition temperature is -95℃ to -45℃.

[0032] <Condition(iV)>

[0033] The silicon atom content relative to the total amount of the modified conjugated diene polymer is above 100 ppm by mass.

[0034] <Condition(V)>

[0035] The nitrogen atom content relative to the total amount of the modified conjugated diene polymer is above 50 ppm by mass.

[0036] <Condition(Vi)>

[0037] The antioxidant content is less than 0.5 parts by mass relative to 100 parts by mass of the modified conjugated diene polymer.

[0038] [2] The modified conjugated diene polymer as described in [1], wherein the Mooney viscosity measured at 100°C under the above <condition (i)> is 105 or more and 180 or less.

[0039] [3] Modified conjugated diene polymers as described in [1] or [2], wherein the Mooney stress relaxation rate measured at 100°C under the above <condition (ii)> is 0.10 to 0.35.

[0040] [4] The modified conjugated diene polymer as described in any one of [1] to [3], wherein the glass transition temperature of the above <condition (iii)> is -95°C to -55°C.

[0041] [5] The modified conjugated diene polymer as described in any one of [1] to [4], wherein the content of nitrogen atoms in the above <condition (V)> is 80 ppm by mass or more relative to the total amount of the modified conjugated diene polymer.

[0042] [6] The modified conjugated diene polymer as described in any one of [1] to [5], wherein the molecular weight distribution (PDI; MWD) is 1.4 to 2.5.

[0043] [7] The modified conjugated diene polymer as described in any one of [1] to [6], wherein the 1,2-vinyl bond content is less than 45.0 mol% relative to the total mass of the modified conjugated diene polymer.

[0044] [8] The modified conjugated diene polymer as described in any one of [1] to [7], wherein the degree of branching (Bn) obtained by the GPC-light scattering method with a viscosity detector is 2 or more.

[0045] [9] The modified conjugated diene polymer as described in any one of [1] to [8], wherein, It has a nitrogen atom at at least one end. A branch with at least one star-shaped structure, The aforementioned star-shaped structure has branches derived from vinyl monomers containing alkoxysilyl or halosilyl groups. The aforementioned portions derived from vinyl monomers containing alkoxysilyl or halosilyl groups have a further main-chain branched structure and a coupling structure centered on a nitrogen-containing alkoxysilane substituent.

[0046]

[10] The modified conjugated diene polymer as described in any one of [1] to [9], wherein, In the above coupling structure centered on a nitrogen-containing alkoxysilane substituent, the nitrogen-containing alkoxysilane modifier residue has at least four silicon atoms, as well as alkoxy and / or hydroxyl groups. The modified conjugated diene polymer chain with a main chain branching structure is bonded to the silicon atoms, and the number of the alkoxy groups and / or hydroxyl groups in the modifier residues is on average greater than the number of silicon atoms.

[0047]

[11] A briquette containing 100 parts by weight of any one of the modified conjugated diene polymers described in [1] to

[10] and less than 2 parts by weight of a softener component.

[0048]

[12] A briquette containing 100 parts by weight of any one of the modified conjugated diene polymers described in [1] to

[10] and less than 1 part by weight of a softener component.

[0049]

[13] A method for manufacturing a modified conjugated diene polymer, which is a method for manufacturing a modified conjugated diene polymer as described in any one of [1] to

[10] , comprising the following steps: A process of polymerizing at least a conjugated diene compound in the presence of an organolithium compound having at least one nitrogen atom within the molecule; and The branching process of obtaining branched conjugated diene polymers with a main-chain branched structure using a branching agent. In the process of coupling the above-mentioned branched conjugated diene polymer with a coupling agent and / or modifying it with a modifier having a nitrogen-containing group, the above-mentioned coupling agent and / or the above-mentioned modifier are added in excess.

[0050]

[14] A rubber composition comprising: 100 parts by weight of rubber component; and Filler material of 5.0 to 150 parts by weight Of the above rubber components, relative to 100 parts by mass of the total amount of the above rubber components, there are 10 or more parts by mass of the modified conjugated diene polymer described in any one of [1] to

[10] or the briquettes described in

[11] or

[12] .

[0051]

[15] A tire comprising the rubber composition described in

[14] .

[0052] The effects of the invention

[0053] According to the present invention, a modified conjugated diene polymer can be provided, which is a modified conjugated diene polymer with excellent fuel-saving performance and processability, and has excellent briquetting properties even as a non-oil-extended product without added processing oil. Detailed Implementation

[0054] The specific embodiments of the present invention (hereinafter referred to as "this embodiment") will be described in detail below.

[0055] It should be noted that the following embodiments are illustrative of the present invention, and the present invention is not limited to the following embodiments. The present invention can be suitably modified within the scope of its essential points.

[0056] [Modified conjugated diene polymers]

[0057] The modified conjugated diene polymer of this embodiment satisfies the following conditions (i) to (vi).

[0058] <Condition (i)>

[0059] The Mooney viscosity, measured at 100°C, is between 100 and 180.

[0060] <Condition(ii)>

[0061] The Mooney stress relaxation rate, measured at 100°C, ranged from 0.10 to 0.40.

[0062] <Condition (iii)>

[0063] The glass transition temperature is -95℃ to -45℃.

[0064] <Condition(iV)>

[0065] The silicon atom content relative to the total amount of the modified conjugated diene polymer is above 100 ppm by mass.

[0066] <Condition(V)>

[0067] The nitrogen atom content relative to the total amount of the modified conjugated diene polymer is above 50 ppm by mass.

[0068] <Condition(Vi)>

[0069] The antioxidant content is less than 0.5 parts by mass relative to 100 parts by mass of the modified conjugated diene polymer.

[0070] The modified conjugated diene polymer of this embodiment has excellent fuel-saving performance and processability. Even when it is a non-oil-extended product without added processing oil, the reduction in thermal stability is suppressed, and the briquetting performance is excellent.

[0071] The modified conjugated diene polymer of this embodiment exhibits extremely excellent processability when forming sulfides, and tends to achieve a particularly excellent balance between low hysteresis loss and anti-slip properties after being formed into sulfides. Furthermore, the modified conjugated diene polymer of this embodiment tends to exhibit excellent wear resistance after being formed into sulfides, good strain dispersion at 50°C, excellent repeated strain strength, and practically sufficient destructive properties.

[0072] The modified conjugated diene polymer in this embodiment can be any of the following: a homopolymer of a single conjugated diene compound, a polymer of different types of modified conjugated diene compounds (i.e., a copolymer), or a copolymer of a conjugated diene compound and a vinyl aromatic compound.

[0073] Examples of conjugated diene compounds include, but are not limited to, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 3-methyl-1,3-pentadiene, 1,3-hexadiene, and 1,3-heptadiene. Among these, 1,3-butadiene and isoprene are preferred from the perspective of effectively and reliably achieving the effects of this embodiment. These conjugated diene compounds can be used individually or in combination of two or more.

[0074] Furthermore, 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 achieving the effects of this embodiment. These vinyl aromatic compounds may be used alone or in combination of two or more.

[0075] (Condition (i): Mooney viscosity of the modified conjugated diene polymer)

[0076] Mooney viscosity is an indicator that represents the comprehensive characteristics of modified conjugated diene polymers, including information such as molecular weight, molecular weight distribution, degree of branching, and softener content. Furthermore, the method for measuring Mooney viscosity is specified by ISO 289, and the measurement error based on mechanical error is very small, making it extremely effective in controlling the properties of modified conjugated diene polymers.

[0077] The modified conjugated diene polymer of this embodiment has a Mooney viscosity (hereinafter also referred to as "Mooney viscosity" or "ML") of 100 or more when measured at 100°C. From the perspective of handling stability, breaking strength and wear resistance when the crosslinking rubber composition is used in tires, it is preferably 105 or more, and more preferably 115 or more.

[0078] On the other hand, the upper limit is 180 or less. From the perspective of the moldability, productivity, and processability of the rubber composition of this embodiment, which is composed of various shapes such as sheet or block, the upper limit is preferably 170 or less, more preferably 160 or less, and even more preferably 150 or less.

[0079] Generally, the higher the Mooney viscosity, the better the handling stability, breaking strength, and abrasion resistance when using modified conjugated diene polymers and their rubber compositions in tires. On the other hand, the moldability of sheet or block molded articles containing modified conjugated diene polymers and rubber compositions tends to deteriorate. Usually, when the Mooney viscosity is 100 or higher, it is necessary to mix in processing oil in order to form briquettes. However, in the modified conjugated diene polymer of this embodiment, as described below, specific Mooney viscosity, Mooney stress relaxation rate, glass transition temperature, silicon content, and nitrogen content are defined. Therefore, the modified conjugated diene polymer of this embodiment has the following significant characteristics: even polymers with a Mooney viscosity of 100 or higher, which are usually difficult to briquette without the addition of processing oil, can be briquetteed. In addition, by limiting the Mooney viscosity to 180 or lower, the peeling of the modified conjugated diene polymer from the briquettes can be suppressed, exhibiting good briquette moldability.

[0080] The Mooney viscosity of the modified conjugated diene polymers was determined by the following method.

[0081] First, the modified conjugated diene polymer was pressurized into a plate shape. The resulting sample was placed in an apparatus and preheated at 100°C for 1 minute. Then, the rotor was rotated at 2 rpm, and the torque was measured after 4 minutes. The measured value was taken as the Mooney viscosity (ML). (1+4) More specifically, the determination can be performed using the methods described in the embodiments described later.

[0082] The Mooney viscosity of the modified conjugated diene polymer in this embodiment can be controlled within the above-mentioned range by adjusting the type, timing, and amount of branching agent and coupling modifier, as well as the molecular weight, molecular weight distribution, and degree of branching of the modified conjugated diene polymer.

[0083] (Condition (ii): Mooney stress relaxation rate of the modified conjugated diene polymer)

[0084] The modified conjugated diene polymer of this embodiment has a Mooney stress relaxation rate (hereinafter also referred to as "Mooney stress relaxation rate" or "MSR") of 0.40 or less when measured at 100°C. From the perspective of processability of the rubber composition mixed with filler materials, it is preferably 0.35 or less, and more preferably 0.30 or less. On the other hand, the Mooney stress relaxation rate is 0.10 or more. From the perspective of handling stability and breaking strength when the conjugated diene polymer of this embodiment is used in tire materials, it is preferably 0.15 or more, and more preferably 0.20 or more.

[0085] Mooney stress relaxation rate, like Mooney viscosity, is affected by the molecular weight, molecular weight distribution, branching degree, and softener content of the modified conjugated diene polymer, and thus becomes an indicator of the comprehensive characteristics of the modified conjugated diene polymer.

[0086] MSR can be measured using a Mooney viscometer as follows.

[0087] Under the condition that the Mooney stress relaxation rate is measured at a temperature of 100℃, the sample is first preheated for 1 minute, and then the rotor is rotated at 2 rpm. The Mooney viscosity (ML) is then determined based on the torque after 4 minutes. (1+4) The measurement was performed, and then the rotor rotation was stopped immediately. The torque was recorded in Mooney units every 0.1 seconds during the period from 1.6 seconds to 5 seconds after stopping. A double logarithmic plot of torque and time (seconds) was performed, and the slope of the straight line at this time was calculated. Its absolute value was taken as the Mooney stress relaxation rate (MSR).

[0088] More specifically, the determination can be performed using the methods described in the embodiments described later.

[0089] The Mooney stress relaxation rate of the modified conjugated diene polymer in this embodiment can be controlled within the above-mentioned value range by adjusting the type, timing, and amount of branching agent and coupling modifier, as well as the molecular weight, molecular weight distribution, and degree of branching of the modified conjugated diene polymer.

[0090] (Condition (iii) Glass transition temperature of modified conjugated diene polymers)

[0091] The modified conjugated diene polymer of this embodiment has a glass transition temperature (hereinafter also referred to as "Tg") of -95°C or higher, preferably -78°C or higher, and more preferably -65°C or higher. By setting the glass transition temperature to -95°C or higher, the processability during vulcanization is excellent. Furthermore, the modified conjugated diene polymer of this embodiment has a glass transition temperature of -45°C or lower, preferably -55°C or lower, more preferably -58°C or lower, and even more preferably -60°C or lower. By setting the glass transition temperature to -45°C or lower, the vulcanizate of the modified conjugated diene polymer exhibits excellent breaking strength, abrasion resistance, and low hysteresis loss.

[0092] The glass transition temperature can also be set within a range formed by any combination of the aforementioned upper and lower limits. The glass transition temperature of the modified conjugated diene polymer can be determined according to ISO 22768:2017. More specifically, a DSC curve is recorded by performing differential scanning calorimetry (DSC) measurements while heating within a specified temperature range, and the peak (inflection point) of the DSC differential curve is taken as the glass transition temperature. Specifically, it can be determined using the method described in the examples below.

[0093] (Condition (iv): Silicon atom content)

[0094] In this embodiment, the modified conjugated diene polymer exhibits excellent fuel-saving performance even as a non-oil-extended product without added processing oil. The silicon atom content, relative to the total amount of the modified conjugated diene polymer, is 100 ppm by mass or more. Regarding the silicon atom content, a 0.5g sample of the modified conjugated diene polymer was used as a sample and measured using a UV-Vis spectrophotometer (Shimadzu Corporation, trade name "UV-1800") according to JIS K0101 44.3.1. Quantification was performed using the molybdenum blue spectrophotometric method.

[0095] Typically, the silicon atom content serves as an indicator of the amount of coupling agent and modifier added to the modified conjugated diene polymer. For example, modified conjugated diene polymers with low molecular weight often have high silicon content. As the molecular weight increases, the amount of coupling agent and modifier added to the modified conjugated diene polymer decreases, thus the silicon content tends to decrease. By containing silicon atoms, the interaction with filler materials added during composition preparation, such as silicon oxide, tends to become stronger. In this embodiment, the silicon atom content in the modified conjugated diene polymer is 100 ppm by mass or more, preferably 130 ppm by mass or more, and more preferably 150 ppm by mass or more.

[0096] The silicon atom content in the modified conjugated diene polymer of this embodiment is preferably 500 ppm by mass or less, more preferably 400 ppm by mass or less, and even more preferably 350 ppm by mass or less.

[0097] The silicon atom content can be controlled within the above range by adjusting the amount of modifier and coupling agent added, as well as the reaction method.

[0098] (Condition (v): Nitrogen content)

[0099] In the modified conjugated diene polymer of this embodiment, the nitrogen atom content is 50 ppm by mass or more relative to the total amount of the modified conjugated diene polymer.

[0100] The nitrogen content (hereinafter also referred to as "nitrogen content") is the total amount of nitrogen atoms in nitrogen-containing functional groups of modified conjugated diene polymers, such as those at the start end, in the main chain, and at the end of the chain.

[0101] Regarding the nitrogen content of the modified conjugated diene polymer, considering the balance between processability, low hysteresis loss and anti-slip properties, wear resistance, and destructive characteristics, the nitrogen content relative to the total amount of the modified conjugated diene polymer is preferably 50 ppm by mass or more, more preferably 60 ppm by mass or more, more preferably 70 ppm by mass or more, and even more preferably 80 ppm by mass or more. Furthermore, considering processability, it is preferably 800 ppm by mass or less, more preferably 700 ppm by mass or less, even more preferably 600 ppm by mass or less, and even more preferably 500 ppm by mass or less.

[0102] The nitrogen content can be determined using the oxidative combustion-chemiluminescence method (JIS-2609: Crude oil and crude oil products - Test method for nitrogen composition).

[0103] The nitrogen atom content can be determined more specifically by the methods described in the examples below.

[0104] The nitrogen content mentioned above can be controlled by adjusting the amount of modifier added and the reaction method, thereby achieving a nitrogen content of 50 ppm or higher by mass. Examples include: a polymerization method using an organolithium compound having at least one nitrogen atom in its molecule (described later) as a polymerization initiator; and a method of obtaining a modified conjugated diene polymer with nitrogen atoms by copolymerizing monomers having at least one nitrogen atom in their molecule, followed by reacting the modified conjugated diene polymer with a modifier having at least one nitrogen atom in its molecule.

[0105] In addition, as a method for obtaining modified conjugated diene polymers with a nitrogen content of less than 500 ppm by mass, one example is a method that controls the molecular weight of the modified conjugated diene polymer chain in a way that prevents it from becoming too small.

[0106] <Condition (vi): Antioxidant content>

[0107] In the modified conjugated diene polymer of this embodiment, the content of antioxidant is 0.5 parts by mass or less per 100 parts by mass of the modified conjugated diene polymer.

[0108] The antioxidant content (hereinafter also referred to as "antioxidant content") is the total amount of antioxidants contained in the modified conjugated diene polymer, which is added to ensure thermal stability. For example, modified conjugated diene polymers with high molecular weight and high Mooney viscosity typically have a high amount of antioxidants added. As the molecular weight increases, the amount of antioxidants added in the modified conjugated diene polymer tends to increase.

[0109] Furthermore, introducing modifying groups at both ends of the polymer chain increases the nitrogen content in the modified conjugated diene polymer, which reduces thermal stability and sometimes requires the addition of large amounts of antioxidants. On the other hand, from the perspective of reducing product costs and environmental impact, it is preferable to reduce the amount of antioxidant used. The modified conjugated diene polymer of this embodiment can be compressed into blocks with reduced antioxidant content by meeting specified conditions. From the above perspective, the antioxidant content is 0.5 parts by mass or less, preferably 0.45 parts by mass or less, more preferably 0.40 parts by mass or less, and even more preferably 0.35 parts by mass or less, relative to 100 parts by mass of the modified conjugated diene polymer. In addition, from the perspective of thermal stability, it is preferably 0.1 parts by mass or more, more preferably 0.2 parts by mass or more, and even more preferably 0.3 parts by mass or more.

[0110] The content of antioxidants can be determined by HPLC analysis as described later.

[0111] (Average molecular weight and molecular weight distribution)

[0112] In the modified conjugated diene polymer of this embodiment, the weight-average molecular weight, as determined by GPC, is preferably 45 × 10⁻⁶. 4 The above, and more preferably 50×10 4 The above, and more preferably 60×10 4 The above, and even more preferably 65×10 4 Above, and further to 70×10 4 The above. If the weight-average molecular weight determined by GPC is 45 × 10⁴... 4 The above results in even better low hysteresis loss properties of its sulfide. Furthermore, the preferred weight-average molecular weight is 250 × 10⁻⁶. 4 The following, and more preferably, is 200×10 4 The following, and more preferably, is 150×10 4 The following, and even more preferably, is 120×10 4 The following applies if the weight-average molecular weight is 250 × 10⁻⁶. 4 The following tend to have better dispersibility of the filler material in its sulfide and can obtain practically sufficient destructive properties.

[0113] The weight-average molecular weight can be any combination of the above upper and lower limits.

[0114] The weight-average molecular weight of the modified conjugated diene polymers can be determined by the methods described in the examples below.

[0115] In the modified conjugated diene polymer of this embodiment, the number-average molecular weight, as determined by GPC, is preferably 20 × 10⁻⁶. 4 The above, and more preferably 25×10 4 The above, and more preferably 30×10 4 The above. The number-average molecular weight can also be 35 × 10⁻⁶. 4 The above. If the number-average molecular weight determined by GPC is 20 × 10⁻⁶. 4 The above-mentioned materials tend to exhibit superior processability during vulcanization and superior low hysteresis loss properties in their sulfides. Furthermore, the preferred number-average molecular weight is 100 × 10⁻⁶. 4 The following, or more preferably, is 90×10 4 The following, and more preferably, is 80×10 4 The following, and more preferably 70×10 4 The following applies if the number-average molecular weight is 20 × 10⁻⁶. 4 The above-mentioned materials tend to have better dispersibility of filler materials in their sulfides and can achieve practically sufficient destructive properties.

[0116] The number-average molecular weight can be any combination of the above upper and lower limits.

[0117] The number-average molecular weight of the modified conjugated diene polymers can be determined by the methods described in the examples below.

[0118] In the modified conjugated diene polymer of this embodiment, from the perspectives of processability during vulcanization, abrasion resistance of the sulfide, and breaking strength, the ratio (Mw / Mn) of the weight-average molecular weight (Mw) measured by GPC to the number-average molecular weight (Mn) measured by GPC (molecular weight distribution, PDI (Poly Dispersity Index); MWD (molecular weight distribution)) is preferably 1.4 or more, more preferably 1.5 or more, further preferably 1.6 or more, and even more preferably 1.7 or more. Furthermore, the upper limit of the molecular weight distribution is not particularly limited, but is generally preferably 2.5 or less, more preferably 2.2 or less, even more preferably 2.0 or less, and even more preferably 1.9 or less.

[0119] The molecular weight distribution of modified conjugated diene polymers can be controlled within the above-mentioned range by adjusting polymerization conditions such as monomers, polymerization initiators, types and amounts of polar compounds, polymerization time, polymerization temperature, amount and type of coupling modifiers, and combinations of two or more when used.

[0120] (Microstructure of modified conjugated diene polymers)

[0121] The microstructure of modified conjugated diene polymers (the amount of bonded vinyl aromatic compounds, the amount of bonded conjugated diene compounds, and the proportion of vinyl bonds in the bonded conjugated diene compounds) affects the glass transition temperature of the modified conjugated diene polymers. Therefore, from the perspective of controlling the glass transition temperature, there are preferred ranges for the amount of vinyl aromatic compounds and the amount of vinyl bonds. In the microstructure of the modified conjugated diene polymer, the amount of bonded vinyl aromatic compounds is not particularly limited, but relative to the total amount of the modified conjugated diene polymer, it is preferably 1% to 40% by mass, more preferably 1% to 36% by mass, further preferably 1% to 30% by mass, more preferably 2% to 29% by mass, even more preferably 3% to 28% by mass, and particularly preferably 5% to 27% by mass. If the amount of bonded vinyl aromatic compounds is within the above range, the modified conjugated diene polymer tends to have superior sulfide breaking strength, abrasion resistance, and low hysteresis loss. It should be noted that if the amount of bonded vinyl aromatic compounds increases, the Tg of the modified conjugated diene polymer tends to increase; if the amount of bonded vinyl aromatic compounds decreases, the Tg tends to decrease.

[0122] In this specification, "amount of bonded vinyl aromatic compounds" refers to the portion of aromatic vinyl compounds used as monomers.

[0123] It should be noted that in modified conjugated diene polymers containing vinyl aromatic compounds, setting the vinyl bond content and vinyl aromatic compound content in the conjugated diene unit to a lower level tends to decrease the Tg of the modified conjugated diene polymer and increase the wear resistance and low hysteresis of the sulfide. Therefore, it is necessary to design polymers with such a structure. On the other hand, setting the vinyl bond content and vinyl aromatic compound content to a lower level may negatively affect the moldability when producing block-shaped briquettes and the processability when producing sulfides. In particular, for non-oil-extended products that are difficult to briquette, reducing the vinyl bond content and vinyl aromatic compound content tends to limit practical applications.

[0124] To address these issues, the inventors discovered that by using the modified conjugated diene polymer of this embodiment, even after the modified conjugated diene polymer is de-oiled, briquetting is still effective. Therefore, in the microstructure design of the de-oiled product, the limitations of not being able to reduce the amount of vinyl bonds and the content of vinyl aromatic compounds are mitigated, and a lower glass transition temperature can be set.

[0125] In the microstructure of the modified conjugated diene polymer, the amount of bonded conjugated diene compound is not particularly limited, but is preferably 60% to 99% by mass, more preferably 64% to 99% by mass, further preferably 70% to 99% by mass, more preferably 71% to 98% by mass, even more preferably 72% to 97% by mass, and particularly preferably 73% to 95% by mass. If the amount of bonded conjugated diene compound is within the above range, the modified conjugated diene polymer tends to have superior sulfide breaking strength, abrasion resistance, and low hysteresis loss. It should be noted that in this specification, "amount of bonded conjugated diene compound" refers to the content of the portion of the conjugated diene compound as a monomer.

[0126] In the microstructure of the modified conjugated diene polymer, the 1,2-vinyl bond content (hereinafter also referred to as "vinyl bond amount") relative to the total mass of the modified conjugated diene polymer is not particularly limited, but is preferably 11.0 mol% to 60.0 mol% or less, more preferably 11.0 mol% to 45.0 mol% or less, further preferably 12.0 mol% to 35.0 mol% or less, further more preferably 13.0 mol% to 34.0 mol% or less, even more preferably 14.0 mol% to 33.0 mol% or less, and particularly preferably 15.0 mol% to 30.0 mol% or less. When the vinyl bond amount is within the above range, the linearity of the structure of the conjugated diene moiety is improved and the entanglement of the polymer chains is strengthened in the modified conjugated diene polymer, thus tending to have better breaking strength and wear resistance. Furthermore, when the vinyl bond amount is within the above range, the low hysteresis loss of its sulfide tends to be more pronounced.

[0127] It should be noted that if the amount of vinyl bonding increases, the temperature coefficient (Tg) increases; if the amount of vinyl bonding decreases, the Tg decreases. In this specification, "the amount of vinyl bonding in the bonded conjugated diene" refers to the proportion of the vinyl-bonded portion of the conjugated diene compound (hereinafter referred to as "bonded conjugated diene").

[0128] (Branching degree (Bn))

[0129] 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') has the following value.

[0130] Generally, branched polymers tend to have smaller molecular sizes compared to linear polymers with the same absolute molecular weight. Here, "molecular size" refers to the actual volume occupied by the molecule. The shrinkage factor (g') relatively represents the molecular size of the polymer in question and is an indicator of the ratio of the molecular size of the polymer in question to the molecular size of a linear polymer with the same absolute molecular weight. That is, if the degree of branching of the polymer is high, its size is relatively small, and therefore the shrinkage factor (g') tends to be small.

[0131] Here, it is known that there is a correlation between the molecular size of a polymer and its intrinsic viscosity ratio. Therefore, in this embodiment, the shrinkage factor (g') is defined in terms of the intrinsic viscosity ratio. That is, the shrinkage factor (g') is defined as the ratio of the intrinsic viscosity [η] of the polymer in question to the intrinsic viscosity [η0] of a linear polymer having the same absolute molecular weight as the polymer in question ([η] / [η0]).

[0132] It should be noted that the intrinsic viscosity [η0] of linear polymers is known to follow the rule [η0] = 10. -3.498 M 0.711 The relationship is given by the formula. In this formula, M represents the absolute molecular weight. Therefore, by measuring the absolute molecular weight and intrinsic viscosity of the polymer using GPC-light scattering with a viscosity detector, the shrinkage factor (g') and branching degree (Bn) can be determined. The calculated branching degree (Bn) accurately reflects the number of polymer chains directly or indirectly bonded to each other relative to the longest polymer backbone.

[0133] Here, "absolute molecular weight" refers to the molecular weight determined by light scattering. As mentioned above, generally, the molecular size of branched polymers tends to be smaller compared to linear polymers with the same absolute molecular weight. Therefore, in GPC determination (i.e., a method to determine molecular weight by sieving polymers by molecular size and comparing them relative to a standard polystyrene sample), the molecular weight of branched polymers tends to be evaluated as too small. On the other hand, in light scattering, the molecular weight is determined by direct observation of the molecules. Therefore, light scattering is not affected by the polymer structure or the interaction with the column packing material, and can accurately determine the molecular weight. It should be noted that the absolute molecular weight can be determined by the method described in the examples below.

[0134] In addition, "intrinsic viscosity" ideally refers to the viscosity [η] obtained by the following formula (I).

[0135] It should be noted that in equation (I), η1 represents the viscosity of the polymer to be dissolved in the solvent at a concentration c, and η2 represents the viscosity of the solvent.

[0136] In this specification, the intrinsic viscosity is the value obtained by the method described in the examples below.

[0137] [Number 1]

[0138] The aforementioned shrinkage factor exhibits a reduction rate in molecular size, but does not accurately represent the branching structure of the polymer.

[0139] Therefore, the degree of branching (Bn) of the modified conjugated diene polymer was calculated using the shrinkage factor (g') at each absolute molecular weight. The calculated degree of branching (Bn) accurately reflects the number of polymers directly or indirectly bonded to each other relative to the longest main chain structure.

[0140] The calculated degree of branching (Bn) is an indicator of the branched structure of the modified conjugated diene polymer. For example, in the case of a typical 4-branched star polymer (with 4 polymer chains connected in the central part), the degree of branching (Bn) is evaluated as 2 relative to the arm with 2 polymer chains bonded to the longest highly branched backbone structure.

[0141] In the case of a typical 8-branched star polymer, the degree of branching (Bn) is evaluated as 6 relative to the longest highly branched main chain structure with 6 polymer chain arms.

[0142] In the modified conjugated diene polymer of this embodiment, the degree of branching (Bn) is preferably 2 or more. In this case, it means that it is a modified conjugated diene polymer with the same branching as the star polymer structure that is branched into 4 as a star polymer structure.

[0143] Here, "branching" refers to the structure formed by direct or indirect bonding with other polymers relative to a single polymer. Furthermore, "degree of branching (Bn)" refers to the number of polymers directly or indirectly bonded to each other relative to the longest main chain structure.

[0144] By achieving a branching degree (Bn) of 2 or higher, the modified conjugated diene polymer of this embodiment exhibits excellent processability when producing sulfides, and the resulting sulfides possess excellent wear resistance and breaking strength.

[0145] Generally, as the absolute molecular weight increases, the processability tends to deteriorate. In the case of an increase in absolute molecular weight in a linear polymer structure, the viscosity increases significantly when making sulfides, and the processability deteriorates significantly.

[0146] Therefore, even with the introduction of numerous functional groups into the polymer to enhance its affinity and / or reactivity with silica as a filler, silica cannot be adequately dispersed in the polymer during the mixing process. Consequently, the introduced functional groups fail to function properly, and the expected improvements in low hysteresis loss and anti-slip properties resulting from their introduction are not achieved.

[0147] On the other hand, in the modified conjugated diene polymer of this embodiment, by making the degree of branching (Bn) 2 or higher, the increase in viscosity during the production of sulfides, which is associated with the increase in absolute molecular weight, can be significantly suppressed. Therefore, for example, by thoroughly mixing with silica or the like in the mixing process, silica can be dispersed around the modified conjugated diene polymer. As a result, for example, in the modified conjugated diene polymer, abrasion resistance and breaking strength can be improved by setting a larger molecular weight, and by thoroughly mixing, silica can be dispersed around the polymer, allowing functional groups to function and / or react. This enables it to have practically sufficient low hysteresis loss and anti-slip properties.

[0148] The absolute molecular weight of the modified conjugated diene polymer can be determined by the method described in the examples below.

[0149] The degree of branching (Bn) of the modified conjugated diene polymer in this embodiment is preferably 2 or more, more preferably 3 or more, further preferably 4 or more, even more preferably 5 or more, particularly preferably 6 or more, and even more preferably 8 or more.

[0150] Modified conjugated diene polymers with a branching degree (Bn) within this range tend to have excellent processability and briquetting properties when producing sulfides.

[0151] In addition, there is no particular limit to the upper limit of branching degree (Bn), which can be above the detection limit, preferably 84 or less, more preferably 80 or less, further preferably 60 or less, especially preferably 40 or less, and even more preferably 20 or less.

[0152] In the modified conjugated diene polymer of this embodiment, by making the degree of branching (Bn) 84 or less, it tends to have excellent wear resistance after being made into a sulfide.

[0153] The degree of branching of modified conjugated diene polymers can be controlled to be above 2 by combining the amount of branching agent and the amount of terminal coupling agent added. Specifically, the degree of branching can be controlled by the number of functional groups of the branching agent, the amount of branching agent added, the timing of the branching agent addition, and the number of functional groups and the amount of coupling agent or nitrogen-containing modifier added. More specifically, as described in the method for manufacturing modified conjugated diene polymers below.

[0154] Generally, the higher the absolute molecular weight of a polymer, the better its abrasion resistance and breaking strength tend to be. However, with the increase of the absolute molecular weight of polymers with low branching degree, polymer particles are prone to peeling off from the surface of the briquette, resulting in poor briquetting properties. Furthermore, there is a tendency for a significant increase in viscosity and a significant deterioration in processability during vulcanization. Therefore, even if a large number of functional groups are introduced into the polymer with low branching degree to improve its affinity and / or reactivity with silica, which is used as a filler material, silica cannot be sufficiently dispersed in the polymer during the mixing process. As a result, the freedom of molecular weight design is limited due to processability constraints.

[0155] (Modified groups)

[0156] The modified conjugated diene polymer of this embodiment preferably has modified groups.

[0157] "Modified groups" refer to functional groups that have affinity or bonding reactivity with the filler material; examples include functional groups containing nitrogen atoms.

[0158] The modified conjugated diene polymer of this embodiment, by having such a modifying group, further enhances its interaction with the filler material. Therefore, after preparing a composition comprising the modified conjugated diene polymer and the filler material, the breaking strength of the composition is further improved. Similarly, the modified conjugated diene polymer of this embodiment preferably has a modifying group containing a nitrogen atom, and more preferably has a modifying group containing both nitrogen and silicon atoms. Alternatively, it is not necessary for a single modifying group or coupling modifier to contain both nitrogen and silicon atoms; instead, modifying groups containing only one of these atoms or coupling modifiers containing modifying groups can be combined in such a way that the polymer contains both nitrogen and silicon.

[0159] (Modification rate)

[0160] In this specification, when a nitrogen-containing lithium compound is used as the initiator described later, and a mixture of modified and unmodified conjugated diene polymers is obtained by modifying the conjugated diene polymer with a coupling modifier, the "modification rate" is expressed as a percentage by mass (%), representing the content of the modified conjugated diene polymer component having a specific functional group that has affinity or bonding reactivity with the filler material relative to the total amount of the conjugated diene polymer mixture. Therefore, when the specific functional group contains nitrogen atoms, it represents the mass ratio of the modified conjugated diene polymer containing nitrogen atoms relative to the total amount of the conjugated diene polymer mixture.

[0161] In this specification, unless otherwise stated or clearly distinguished as "conjugated diene polymers or modified conjugated diene polymers" are listed side by side, "conjugated diene polymers" includes both unmodified conjugated diene polymers and modified conjugated diene polymers.

[0162] It should be noted that when listed in parallel terms such as "conjugated diene polymers or modified conjugated diene polymers", "conjugated diene polymers" refers to unmodified conjugated diene polymers.

[0163] For example, in a conjugated diene polymer comprising a modified conjugated diene polymer modified by reacting a nitrogen-containing modifier with a termination end, the mass ratio of the modified conjugated diene polymer having nitrogen-containing functional groups arising from the nitrogen-containing modifier to the total amount of the conjugated diene polymer is used as the modification rate.

[0164] The modified conjugated diene polymer of this embodiment preferably has at least a nitrogen atom at its terminal end, and more preferably, it is modified using functional groups containing nitrogen and silicon atoms, separate from the terminal nitrogen atom. Such modified conjugated diene polymers exhibit superior processability when used in the preparation of rubber compositions such as blended fillers, and also tend to have superior abrasion resistance, breaking strength, and low hysteresis loss after the rubber composition is vulcanized. It should be noted that, as described above, it is not necessary for a single modifying group or coupling modifier to contain both nitrogen and silicon atoms; instead, modifying groups or coupling modifiers containing only one of these atoms can be combined in such a way that the final modified conjugated diene polymer contains both nitrogen and silicon.

[0165] From the perspective of improving the low hysteresis loss property of sulfides, the modification rate of the modified conjugated diene polymer in this embodiment is preferably 85% by mass or more, more preferably 88% by mass or more, further preferably 89% by mass or more, further more preferably 90% by mass or more, and even more preferably 91% by mass or more, relative to the total amount of modified conjugated diene polymer. There is no particular limitation on the upper limit of the above modification rate; it can be 100% by mass, 98% by mass or less, 96% by mass or less, or 95% by mass or less. Furthermore, when comparing modified conjugated diene polymers with the same glass transition point, a higher modification rate tends to result in superior low hysteresis loss property.

[0166] In the modified conjugated diene polymer of this embodiment, the modification rate can be determined by a chromatographic method capable of separating the modified component containing functional groups from the unmodified component. As a method for using this chromatographic method, the following method can be cited: using a gel permeation chromatography column with a polar substance such as silica that adsorbs specific functional groups as the packing material, and using an internal standard of the unadsorbed component for comparison to quantify the composition (column adsorption GPC method).

[0167] More specifically, regarding the modification rate, the adsorption amount on the silica column can be calculated based on the difference between the chromatogram obtained by measuring the sample solution containing the sample and the low molecular weight internal standard polystyrene using a polystyrene-based gel column and the chromatogram obtained by measuring the sample solution using a silica-based column, thereby obtaining the modification rate. Specifically, the modification rate can be determined by the method described in the examples below.

[0168] In the modified conjugated diene polymer of this embodiment, the modification rate can be controlled within the above-mentioned numerical range by adjusting the amount of coupling modifier added and the reaction method between the modified conjugated diene compound and the modifier.

[0169] For example, a combination of two or more of the following methods may be used: polymerization using an organolithium compound having at least one nitrogen atom in the molecule as a polymerization initiator, copolymerization of a monomer having at least one nitrogen atom in the molecule, and modification using a modifier with the structure described later.

[0170] (Structure of modified conjugated diene polymers)

[0171] The modified conjugated diene polymer of this embodiment preferably has a nitrogen atom at at least one end, has at least one star-shaped branch, the star-shaped branch having a portion derived from a vinyl monomer containing alkoxysilyl or halosilyl, the portion derived from the vinyl monomer containing alkoxysilyl or halosilyl having a further main chain branch structure, and has a coupling structure centered on a nitrogen-containing alkoxysilane substituent.

[0172] It should be noted that in this specification, "modified conjugated diene polymer chains bonded to a modifier" refers to the state of a compound formed by polymer chains bonded to a so-called coupling agent (modifier) ​​during the polymer manufacturing process. Therefore, in the structure of the "modifier" (also denoted as "modifier residue") in the polymer, the leaving group disappears from the original modifier, and a polymer chain is bonded, which differs from the initial structure of the modifier. That is, the modifier (residue) contained in the modified conjugated diene polymer is a structural unit of the modified conjugated diene polymer bonded to the modified conjugated diene polymer chain, for example, a structural unit derived from the modifier generated by reacting the conjugated diene polymer described later with the modifier.

[0173] By incorporating both nitrogen and silicon atoms into the modified conjugated diene polymer in the modifier, the interaction with fillers such as silicon oxide added during composition tends to become stronger compared to having only one atom.

[0174] <Star-shaped branched structures with main chain branching in nitrogen-containing conjugated diene polymer chains>

[0175] The modified conjugated diene polymer chain described above preferably has a nitrogen atom at at least one end, has at least one star-shaped branch, the star-shaped branch having a portion derived from a vinyl monomer containing alkoxysilyl or halosilyl, the portion derived from the vinyl monomer containing alkoxysilyl or halosilyl having a further main chain branch structure, and has a coupling structure centered on a nitrogen-containing alkoxysilane substituent.

[0176] The structural unit derived from the modified conjugated diene polymer in this embodiment is a structural unit derived from the modified conjugated diene polymer. For example, for a modified conjugated diene polymer chain derived from an organolithium compound having at least one nitrogen atom in the molecule (described later) and having a nitrogen atom introduced at one end, it has a portion derived from a vinyl monomer containing alkoxysilyl or halosilyl groups. This portion derived from the vinyl monomer containing alkoxysilyl or halosilyl groups has a further main chain branching structure, which can be obtained by reacting the modified conjugated diene polymer with a modifier.

[0177] In the modified conjugated diene polymer of this embodiment, it is preferable that the modified conjugated diene polymer chain with nitrogen atoms at the ends has a portion from a vinyl monomer containing alkoxysilyl or halosilyl groups, and the portion from the vinyl monomer containing alkoxysilyl or halosilyl groups forms a further main chain branch structure, preferably further having a star-shaped branch structure bonded to the modifier, and more preferably the number of alkoxysilane residues of the modifier is greater than the number of conjugated diene polymer chains bonded to the modifier.

[0178] With the above structure, it tends to have excellent processability when producing sulfides and significantly improved fuel efficiency.

[0179] <Nitrogen-containing conjugated diene polymer chains>

[0180] The conjugated diene polymer chain preferably has a nitrogen atom in at least one of the conjugated diene polymer chains.

[0181] For example, a conjugated diene polymer chain having a functional group containing a nitrogen atom at any position, where the functional group can be at the end or in the middle of the main chain. A conjugated diene polymer chain having a nitrogen atom can be obtained, for example, by polymerization using an organolithium compound having at least one nitrogen atom in the molecule (described later) in a polymerization initiator, or by copolymerization of monomers having at least one nitrogen atom in the molecule.

[0182] The modified conjugated diene polymer of this embodiment, or the conjugated diene polymer described later, can have all or part of the double bonds converted into saturated hydrocarbons by further hydrogenation in an inert solvent. In this case, there is a tendency for improved heat resistance, weather resistance, prevention of product deterioration during high-temperature processing, and improved performance as a rubber. As a result, superior performance can be achieved in various applications such as automotive. More specifically, the hydrogenation rate of the unsaturated double bonds in the conjugated diene compound can be arbitrarily selected according to the purpose and is not particularly limited. When used as a sulfide, it is preferable that the double bonds of the conjugated diene portion are partially retained. From this point of view, the hydrogenation rate of the conjugated diene portion in the conjugated diene polymer is preferably 3.0% to 70% and less, more preferably 5.0% to 65% and less, and even more preferably 10% to 60% and less. In particular, by selectively hydrogenating the vinyl group, there is a tendency for improved heat resistance and performance. The hydrogenation rate can be determined using a nuclear magnetic resonance (NMR) apparatus.

[0183] <Main chain branching structure and branching agents>

[0184] The vinyl monomers containing alkoxysilyl or halosilyl groups used in constructing the "main chain branching structure" as described in this specification are referred to as "branching agents".

[0185] As a branching agent, a vinyl monomer containing alkoxysilyl or halosilyl groups, represented by formula (1) or formula (2) below, is preferred. That is, the "main chain branching structure" is preferably composed of atomic groups from a vinyl monomer containing alkoxysilyl or halosilyl groups, represented by formula (1) or formula (2) below.

[0186] [Chemistry 1]

[0187] [Chemistry 2]

[0188] In equation (1), R 1 It represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and a portion thereof may have a branched structure.

[0189] R2 ~R 3 Each can independently represent an alkyl group with 1 to 20 carbon atoms or an aryl group with 6 to 20 carbon atoms, and some of them may have a branched structure. The presence of multiple R groups... 1 ~R 3 Each is independent.

[0190] X 1 This represents an independent halogen atom.

[0191] m represents an integer from 0 to 2, n represents an integer from 0 to 3, and l represents an integer from 0 to 3. (m+n+l) represents 3.

[0192] In equation (2), R 4 ~R 7 Each can independently represent an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and some of them may have a branched structure.

[0193] R in the case of a complex number 4 ~R 7 Each is independent.

[0194] X 2 ~X 3 This represents an independent halogen atom.

[0195] m represents an integer from 0 to 2, n represents an integer from 0 to 3, and l represents an integer from 0 to 3.

[0196] (m+n+l) represents 3.

[0197] 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 an integer of 3.

[0198] The conjugated diene polymer of this embodiment preferably has an R based on the above formula (1). 1 The monomer unit of the compound represented by the above formula (1) with hydrogen atoms and m=0.

[0199] Therefore, the overall branching number of the conjugated diene copolymer is increased, resulting in improved wear resistance and processability.

[0200] Furthermore, the conjugated diene polymer of this embodiment is preferably a modified conjugated diene polymer having monomer units of the compound represented by the above formula (2) with m=0 and b=0 in the above formula (2).

[0201] This results in improved wear resistance and machinability.

[0202] Furthermore, the conjugated diene polymer of this embodiment preferably has R based on the above formula (1). 1The monomer unit of the compound represented by formula (1) with hydrogen atoms, m=0, l=0.

[0203] Therefore, the overall branching degree of the conjugated diene copolymer is increased, resulting in improved wear resistance and processability.

[0204] Furthermore, the conjugated diene polymer of this embodiment is preferably a conjugated diene polymer having monomer units of the compound represented by the above formula (2) with m=0, l=0, a=0, b=0 in the above formula (2).

[0205] This results in improved wear resistance and machinability.

[0206] Furthermore, the conjugated diene polymer of this embodiment is preferably having R based on the above formula (1). 1 The conjugated diene polymer of the monomer unit of the compound represented by the above formula (1) with hydrogen atoms, l=0, n=3.

[0207] The increased modification rate and branching degree result in improved fuel efficiency, wear resistance, and processability.

[0208] The modified conjugated diene polymer of this embodiment is preferably: in the coupling structure centered on a nitrogen-containing alkoxysilane substituent, the nitrogen-containing alkoxysilane modifier residue has at least 4 silicon atoms, as well as alkoxy groups and / or hydroxyl groups, and the modified conjugated diene polymer chain with a main chain branching structure is bonded to silicon atoms. In the modifier residues described later, the number of the above-mentioned alkoxy groups and / or the above-mentioned hydroxyl groups is on average greater than the number of the above-mentioned silicon atoms.

[0209] <Modifier residues containing silicon atoms>

[0210] The modified conjugated diene polymer of this embodiment preferably has silicon atoms in the modifier residues.

[0211] For example, a modified conjugated diene polymer that has silicon atoms in the modifier described later, thereby giving it structural units derived from the modifier.

[0212] Furthermore, the modified conjugated diene polymer of this embodiment preferably has silicon atoms at any position.

[0213] Silicon atoms are preferably bonded to the ends of the conjugated diene polymer chain or in the middle of the main chain in the form of functional groups containing silicon atoms, or contained in the modifier residues. More preferably, at least one silicon atom in the modified conjugated diene polymer constitutes an alkoxysilyl or silanol group having 1 to 20 carbon atoms. This tends to enhance the interaction with filler materials (e.g., silicon oxide) added during the manufacture of sulfides. In addition, from the perspective of the possibility of reacting with air to produce hydrogen halides, the modified conjugated diene polymer preferably does not contain halogens.

[0214] In the aforementioned conjugated diene polymer chains of 8 or more, it is preferable that at least one end is bonded to a silicon atom present in the modifier residue. This tends to make the effects of this embodiment more significant. In this case, the ends of two or more conjugated diene polymer chains can be bonded to one silicon atom. In addition, the ends of the conjugated diene polymer chains and alkoxy or hydroxyl groups having 1 to 20 carbon atoms can be bonded to a silicon atom, resulting in that silicon atom forming an alkoxysilyl or silanol group having 1 to 20 carbon atoms. From the viewpoint that it may react with air or moisture to produce hydrogen halides, the modifier residues preferably do not contain halogens.

[0215] Furthermore, a central branch point as referred to here is a group (atomic cluster) containing substituents that include atoms from the coupling modifier or nitrogen atoms from the modifier, and does not refer to a single atom. For example, a group containing alkoxysilyl groups separated from the amino group by 1 to 5 carbons, preferably 2 to 3 carbons, is a representative central branch point.

[0216] <Modified conjugated diene polymers with star-shaped polymeric structures>

[0217] Modified conjugated diene polymers with star-shaped polymeric structures are produced by increasing the molecular weight through polymerization after constructing branched structural sites from the main chain branched structure, followed by modification with coupling modifiers of three or more functions. These modified conjugated diene polymers have at least one star-shaped branch derived from a vinyl monomer containing an alkoxysilyl or halosilyl group.

[0218] Regarding the method for obtaining a conjugated diene polymer having a further main-chain branched structure in the portion derived from vinyl monomers containing alkoxysilyl or halosilyl groups, the aforementioned "star-shaped polymer structure" can be formed by adjusting the number of functional groups of the modifier and the amount of modifier added, and the "main-chain branched structure" can be controlled by adjusting the number of functional groups of the branching agent, the amount of branching agent added, and the timing of the branching agent addition.

[0219] The modified conjugated diene polymer of this embodiment preferably includes a structure with nitrogen-containing groups represented by any one of the following general formulas (5-1) to (5-4), (7-1) to (7-2), (8), (9-1) to (9-2) in its star-shaped branched structure.

[0220] [Chemistry 3]

[0221] [Chemistry 4]

[0222] [Chemistry 5]

[0223] [Chemistry 6]

[0224] In the above formulas (5-1) to (5-4), R is a hydrocarbon group with a valence of 2 or higher or an organic group with a valence of 2 or higher and a polar group. The polar group is selected from at least one of the following: ethers, epoxy groups, ketones and other polar groups with oxygen; thioethers, thioketones and other polar groups with sulfur; tertiary amino groups, imino groups and other polar groups with nitrogen.

[0225] The alkyl group with a valence of 2 or higher can be saturated or unsaturated, and can be straight-chain, branched, or cyclic, including alkylene, alkenylene, and phenylene. Alkyl groups with 1 to 20 carbon atoms are preferred. Examples include methylene, ethylene, butylene, cyclohexylene, 1,3-bis(methylene)-cyclohexane, 1,3-bis(ethylene)-cyclohexane, o-phenylene, m-phenylene, p-phenylene, m-xylene, p-xylene, and bis(phenylene)-methane.

[0226] In equations (5-1) to (5-4) above, R 24 R 27 R is a hydrocarbon group with 1 to 10 carbon atoms. 24 R 27 They can be the same or different.

[0227] In equations (5-1) to (5-4) above, R 25 R 28 R is a hydrogen or hydrocarbon group having 1 to 10 carbon atoms. 25 R 28 They can be the same or different.

[0228] In (5-1)~(5-4), P 3 P 4 It is a polymer chain and is a forked part with a main chain branching structure [A] or a straight polymer chain without a branching structure.

[0229] In equations (5-1) to (5-4) above, R 26 It is a hydrocarbon group with 1 to 10 carbon atoms, or a structure of the following formulas (6-1) to (6-3).

[0230] [Chemistry 7]

[0231] [Chemistry 8]

[0232] [Chemistry 9]

[0233] R 24 R 25 R 26 It can be a ring structure formed by mutual bonding.

[0234] Additionally, R 26 In the case of a hydrocarbon group, it can be a cyclic structure formed by bonding with R. In the case of the above-mentioned cyclic structure, it can be bonded to R. 26 The N and R on the surface are directly bonded.

[0235] In the above equations (5-1) to (5-4), f is an integer greater than or equal to 1, and g is an integer greater than or equal to 0 or 1.

[0236] In equations (6-1) to (6-3) above, R 29 R 30 R is respectively compared with the above equations (5-1) to (5-4). 24 R 25 Similarly, in equations (6-1) to (6-3) above, P 5 P in equations (5-1) to (5-4) above 3 P 4 The same definition applies.

[0237] R 29 R 30 They can be the same or different.

[0238] [Chemistry 10]

[0239] [Chemistry 11]

[0240] In equations (7-1) to (7-2), P 6 P 7 It is a polymer chain, which is a forked part [A] with a main chain branching structure or a straight polymer chain without a branching structure.

[0241] In P 6 P 7 When multiple bonds are attached (where h, i, or j are integers greater than 2), P 6 P 7 They can be the same as each other, or they can be different.

[0242] R 33 R 34 Each independently represents an alkyl or hydrocarbon group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, R 35 R represents an alkylene group having 1 to 10 carbon atoms. 36 Indicates alkylene groups having 1 to 20 carbon atoms.

[0243] h represents an integer from 1 to 3, i represents an integer from 1 to 3, j represents an integer of 1 or 2, and (h+i) and (h+j) represent integers greater than 3.

[0244] [Chemistry 12]

[0245] In equation (8), P 8 P 9 P 10 It is a polymer chain, which is a forked part [A] with a main chain branching structure or a straight polymer chain without a branching structure.

[0246] P 8 P 9 P 10 When multiple bonds are bonded separately (where m, n, or l are integers greater than 2), P 8 P 9 P 10 They can be the same as each other, or they can be different.

[0247] R 40 ~R 42 Each independently represents an alkyl or hydrocarbon group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, R 43 ~R 45 Each can be used independently to represent an alkylene group having 1 to 20 carbon atoms.

[0248] m, n, and l each independently represent integers from 1 to 3, and (m+n+l) represents integers greater than 3.

[0249] [Chemistry 13]

[0250] [Chemistry 14]

[0251] In equations (9-1) to (9-2), P 11 ~P 14 It is a polymer chain, which is a forked portion [A] with a main chain branching structure or a linear polymer chain without a branching structure. P 11 P 12 When multiple bonds are attached separately (where o or p is an integer greater than 2), P 11 P 12 They can be the same as each other, or they can be different.

[0252] R 46 ~R 48 Each independently represents a single bond or an alkylene group having 1 to 20 carbon atoms, R 49 and R 51 Each independently represents an alkyl or 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, R 55 It refers to an alkyl or trialkylsilyl group having 1 to 20 carbon atoms, which may replace an organic group containing S, O or N and without active hydrogen, and may have unsaturated bonds, which may be the same or different.

[0253] o represents an integer from 1 to 3, p represents 1 or 2, and t represents an integer from 1 to 3.

[0254] R in the case of multiple cases 46 ~R 56 o, p, and t are independent and can be the same or different.

[0255] q represents an integer from 0 to 6, r represents an integer from 0 to 6, s represents an integer from 0 to 6, and (q+r+s) is an integer from 4 to 10.

[0256] A represents a hydrocarbon group with 1 to 20 carbon atoms; or an organic group having at least one atom selected from the group consisting of oxygen, nitrogen, silicon, sulfur and phosphorus atoms and not having active hydrogen.

[0257] In the above formulas (9-1) to (9-2), A is preferably represented by any of the following general formulas (I) to (IV).

[0258] [Chemistry 15]

[0259] In formula (I), B 1 This represents a single bond or a hydrocarbon group with 1 to 20 carbon atoms, where u represents an integer from 1 to 10. The presence of a complex number of B groups... 1Each is independent.

[0260] [Chemistry 16]

[0261] In formula (II), B 2 B represents a single bond or a hydrocarbon group with 1 to 20 carbon atoms. 3 The alkyl group represents alkyl groups with 1 to 20 carbon atoms, and u represents an integer from 1 to 10. The B groups are represented in the case of multiple occurrences. 2 and B 3 Each is independent.

[0262] [Chemistry 17]

[0263] In equation (III), B 4 This represents a single bond or a hydrocarbon group with 1 to 20 carbon atoms, where u represents an integer from 1 to 10. The presence of a complex number of B groups... 4 Each is independent.

[0264] [Chemistry 18]

[0265] In equation (IV), B 5 This represents a single bond or a hydrocarbon group with 1 to 20 carbon atoms, where u represents an integer from 1 to 10. The presence of a complex number of B groups... 5 Each is independent.

[0266] [Molded body]

[0267] The molded article of this embodiment is a molded article containing the conjugated diene polymer of this embodiment described above. From a processability perspective, a sheet or block molded article is preferred.

[0268] There are no particular limitations on the size and thickness of the sheet-like or block-like molded body; for example, a sheet-like molded body with a thickness of about 1 cm and a 1,000 cm thick molded body can be mentioned. 3 A rectangular or cubic block-shaped object.

[0269] The molded body in this embodiment is more preferably a block-shaped molded body. As for the shape of the block, it is preferably a roughly rectangular parallelepiped, and more preferably 1,000 cm. 3 The above-mentioned block (compressed) molded body. In addition, a rectangular compressed block weighing 17.5 kg to 35 kg is even more preferred.

[0270] As a molding method, it is preferable to produce a product with a specific surface area of ​​0.7 m². 2 / g~3.2m 2A method for compressing and molding granules of / g. From the perspective of formability, it is preferable to further perform a sieving process on the granules before molding.

[0271] Because the granules adhere closely to each other during compression molding, the specific surface area of ​​the molded body is smaller than that of the granules. The compactness of the granules during compression molding can be adjusted by the molecular weight, composition, and structure of the conjugated diene polymer, the composition of the plasticizer, and the temperature and pressure during compression. For example, to improve the compactness of the granules and reduce the specific surface area of ​​the compressed body, it is preferable to reduce the molecular weight of the conjugated diene polymer, increase the amount of plasticizer, and increase the temperature and pressure during compression.

[0272] The specific surface area of ​​the molded body in this embodiment is preferably 0.005 to 0.05 m². 2 / g, and more preferably 0.01 to 0.04m from the perspective of film packaging performance. 2 / g. By making the specific surface area of ​​the molded body 0.005m². 2 A concentration of / g or higher can suppress the expansion of the compressed briquettes by achieving a specific surface area of ​​0.05m² for the molded body. 2 Below / g, the agglomerates can be reduced from peeling off the molded body, and are therefore preferred.

[0273] The specific surface area of ​​the molded body can be determined using the BET method.

[0274] Typically, the specific surface area of ​​a large molded body may vary depending on the location, so it is preferable to collect the sample from near the center of the molded body.

[0275] The pellets are preferably sieved according to particle size before being formed, and then mixed in an appropriate ratio.

[0276] If the specific surface area of ​​the molded body formed by directly using the desolventized granules exceeds the upper limit of the above range, it is preferable to increase the composition of large-diameter granules and decrease the composition of small-diameter granules in the granules obtained by sieving. If the specific surface area does not meet the lower limit, it is preferable to decrease the composition of large-diameter granules and increase the composition of small-diameter granules.

[0277] The molding compression pressure of the molded article is preferably 3MPa to 30MPa, more preferably 10MPa to 20MPa. When the compression pressure during molding is below 30MPa, the device can be designed compactly and the installation efficiency is good. When the compression pressure during molding is above 3MPa, the moldability is good. With good moldability, the surface of the molded article is smooth, and polymer peeling will not occur after the molding process, and it tends to suppress post-molding expansion.

[0278] 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 perspective of reducing residual solvent and suppressing thermal degradation.

[0279] When the molding temperature is above 30°C, the moldability is good. On the other hand, when the temperature is below 120°C, gel formation caused by thermal degradation of the rubber composition can be suppressed, which is preferred.

[0280] The higher the temperature and pressure during molding, the smaller the specific surface area of ​​the compressed block.

[0281] The holding time during molding is preferably 3 to 30 seconds, more preferably 5 to 20 seconds. When the holding time during compression is less than 30 seconds, the production efficiency is good; when it is more than 5 seconds, the formability is good.

[0282] To avoid the molded parts from sticking together, it is preferable to use resin film (packaging sheet) for packaging.

[0283] Regarding the type of resin used for the membrane, for example, polyethylene, ethylene copolymer resin, polystyrene, high-impact polystyrene, and PET (polyethylene terephthalate) can be used.

[0284] From the perspectives of ease of handling during transport of the molded body and minimizing condensation at the gap between the packaging sheet and the compact, the packaging sheet with good sealing properties is preferred.

[0285] The molded body of this embodiment is used, for example, for storage in transport containers. If the expansion rate of the molded body after one day is less than 5%, its storage in the container is good and preferred.

[0286] [Preparation method of modified conjugated diene polymers]

[0287] The following provides a detailed description of the method for manufacturing the modified conjugated diene polymer of this embodiment.

[0288] By using the manufacturing method of the modified conjugated diene polymer of this embodiment, the above-mentioned conjugated diene polymer can be obtained reliably and easily. However, the modified conjugated diene polymer of this embodiment is not limited to the polymer manufactured by the following manufacturing method.

[0289] The method for manufacturing the modified conjugated diene polymer of this embodiment includes the following steps: A process of polymerizing at least a conjugated diene compound in the presence of an organolithium compound having at least one nitrogen atom within the molecule; and The branching process (sometimes referred to as the polymerization branching process below) involves using a branching agent to obtain branched modified conjugated diene polymers with a main-chain branched structure. In the process of coupling the above-mentioned branched modified conjugated diene polymer with a coupling agent and / or modifying it with a modifier having a nitrogen-containing group, the above-mentioned coupling agent and / or the above-mentioned modifier are added in excess.

[0290] The process of coupling using a coupling agent and / or the process of modification using a modifier having nitrogen-containing atomic groups can also be a process of adding a coupling modifier.

[0291] The method for manufacturing the conjugated diene polymer in this embodiment preferably involves adding an excess of a modifier with a coupling number of 4 or more as a coupling modifier.

[0292] The polymerization reaction of the conjugated diene compound and the aromatic vinyl compound is preferably carried out via a growth reaction based on living anionic polymerization, thereby obtaining a conjugated diene polymer with active ends. As a result, when a branching agent is added, the conjugated diene polymer reacts efficiently with the branching agent. Furthermore, the manufacturing method of this embodiment tends to allow for highly efficient reaction even when the coupling step described later is included.

[0293] Examples of polymerization reaction forms include, but are not limited to, batch (hereinafter also referred to as "batch") and continuous polymerization reaction forms.

[0294] In a continuous reactor, one or more reactors connected together can be used. Examples of continuous reactors include tank-type and tubular reactors equipped with a stirrer. Preferably, the monomer, the inert solvent (described later), and the polymerization initiator (described later) are continuously loaded into the reactor, a polymer solution containing the polymer is obtained within the reactor, and the polymer solution is continuously discharged.

[0295] As a batch reactor, for example, a tank reactor with a stirrer is used. In the batch reactor, it is preferable to fill the reactor with monomer, an inert solvent (described later), and a polymerization initiator (described later). The monomer is added continuously or intermittently during polymerization as needed, and a polymer solution containing the polymer is obtained in the reactor. The polymer solution is discharged after polymerization is completed.

[0296] In the manufacturing method of this embodiment, from the perspective of obtaining conjugated diene polymers with active ends in a high proportion, it is preferable to carry out the polymerization reaction in a continuous polymerization reaction form that can continuously discharge the polymer and supply it to the next reaction in a short time.

[0297] (Aggregation branch process)

[0298] The polymerization branching step in the method for manufacturing conjugated diene polymers according to this embodiment involves using an organolithium compound having at least one nitrogen atom within its molecule (described later) as a polymerization initiator. A branching agent is added while at least a conjugated diene compound and, if necessary, a vinyl aromatic compound, to polymerize, thereby obtaining a conjugated diene polymer with a branched structure. Therefore, in the polymerization branching step, before the addition of the branching agent, the polymerization reaction of at least the conjugated diene compound and the aromatic vinyl compound is the main reaction; the branching reaction is initiated after the addition of the branching agent.

[0299] As monomers used in the polymerization branching process, namely conjugated diene compounds and vinyl aromatic compounds, it is sufficient to use at least one of the aforementioned conjugated diene compounds and at least one of the aforementioned vinyl aromatic compounds. Furthermore, from the perspective of being able to introduce nitrogen atoms into the conjugated diene polymer, derivatives obtained by substitution in a manner that allows the aforementioned conjugated diene compounds or the aforementioned vinyl aromatic compounds to have at least one nitrogen atom within the molecule can be used.

[0300] <Polymerization initiator>

[0301] Use the specified polymerization initiator in the polymerization process.

[0302] As mentioned above, organolithium compounds can be cited as polymerization initiators, with organolithium compounds having at least one nitrogen atom in the molecule being preferred.

[0303] As organolithium compounds, examples include organomonolithium compounds, which can also be used in combination with other polymerization initiators.

[0304] Examples of organic monolithium compounds include, but are not limited to, low-molecular-weight compounds and soluble oligomers. Furthermore, examples of organic monolithium compounds, in which their organic groups are bonded to lithium, include compounds with carbon-lithium bonds, compounds with nitrogen-lithium bonds, and compounds with tin-lithium bonds.

[0305] The amount of organic single-lithium compound used as a polymerization initiator is preferably determined based on the molecular weight of the target conjugated diene polymer or the modified conjugated diene polymer.

[0306] The amount of monomers such as conjugated dienes tends to be related to the degree of polymerization, i.e., to the number-average molecular weight and / or weight-average molecular weight, relative to the amount of polymerization initiator. Therefore, to increase the molecular weight, the amount of polymerization initiator can be reduced; to decrease the molecular weight, the amount of polymerization initiator can be increased.

[0307] From the perspective of its use in a method of introducing nitrogen atoms into a conjugated diene polymer, the organic monolithium compound is preferably an alkyl lithium compound having a substituted amino group, or a substituted amino lithium compound. In this case, a conjugated diene polymer having a nitrogen atom derived from an amino group at the polymerization initiation end can be obtained. A substituted amino group refers to an amino group that does not have an active hydrogen or whose active hydrogen is protected.

[0308] The organolithium compounds having at least one nitrogen atom in the molecule that serve as polymerization initiators include organolithium compounds represented by any one of the following general formulas (1) to (5).

[0309] [Chemistry 19]

[0310] (In equation (1), R) 10 and R 11 Each independently represents at least one selected from the group consisting of an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, and an aralkyl group having 6 to 20 carbon atoms, and a protecting group, R 10 and R 11 It can bond and form a ring structure with adjacent nitrogen atoms. In this case, R 10 and R 11 This refers to alkyl groups with 5 to 12 carbon atoms, some of which may have unsaturated bonds or branched structures. It should be noted that the protecting group is an alkyl-substituted silyl group.

[0311] [Chemistry 20]

[0312] (In equation (2), R) 12 and R 13 Each independently represents at least one selected from the group consisting of an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, and an aralkyl group having 6 to 20 carbon atoms, and a protecting group, R 12 and R 13 It can bond and form a ring structure with adjacent nitrogen atoms. In this case, R 12 and R 13 This refers to an alkyl group with 5 to 12 carbon atoms, some of which may have unsaturated bonds or branched structures. It should be noted that the protecting group is an alkyl-substituted silyl group. R 14 This refers to alkylene polymers with 1 to 30 carbon atoms that may have aliphatic or aromatic substituents, or conjugated diene polymers with 1 to 20 carbon atoms.

[0313] [Chemistry 21]

[0314] (In equation (3), R) 12 and R 13 Each independently represents at least one selected from the group consisting of alkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to 14 carbon atoms, aralkyl groups having 6 to 20 carbon atoms, and protecting groups, R 12 and R 13 It can bond and form a ring structure with adjacent nitrogen atoms. In this case, R 12 and R 13 This refers to an alkyl group with 5 to 12 carbon atoms, some of which may have unsaturated bonds or branched structures. It should be noted that the protecting group is an alkyl-substituted silyl group. R 19 R represents a hydrocarbon group with 1 to 30 carbon atoms that can have aliphatic or aromatic substituents. 20 (This indicates hydrocarbon groups with 1 to 12 carbon atoms that can have substituted amino groups, where n represents an integer from 1 to 10.)

[0315] [Chemistry 22]

[0316] (In equation (4), R) 15 and R 16 Each independently represents at least one selected from the group consisting of an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, and an aryl group having 6 to 20 carbon atoms, plus a protecting group; R 15 and R 16 It can bond and form a ring structure with adjacent nitrogen atoms. In this case, R 15 and R 16 This refers to alkyl groups with 5 to 12 carbon atoms, some of which may have branched structures. It should be noted that the protecting group is an alkyl-substituted silyl group.

[0317] [Chemistry 23]

[0318] (In equation (5), R) 17 R represents a hydrocarbon group with 2 to 10 carbon atoms, some of which may have unsaturated bonds or branched structures. 18 This refers to alkyl groups with 1 to 12 carbon atoms, and protecting groups, some of which may have branched structures. It should be noted that the protecting group is an alkyl-substituted silyl group.

[0319] In the above equation (1), R is... 10 and R 11Examples of the groups represented include methyl, ethyl, propyl, butyl, octyl, benzyl, cyclopropyl, cyclohexyl, 3-phenyl-1-propyl, isobutyl, decyl, heptyl, and phenyl.

[0320] R 10 and R 11 It is not limited to these groups; if the above conditions are met, it includes their analogues.

[0321] From the perspectives of solubility in solvents, reducing hysteresis loss in the modified conjugated diene polymer composition described later, and controlling the chain transfer reaction described later, butyl and hexyl are preferred, with butyl being more preferred.

[0322] Examples of organolithium compounds having at least one nitrogen atom in the molecule as represented by formula (1) include, but are not limited to, lithium ethylpropylamino, lithium ethylbutylamino, lithium ethylbenzylamino, lithium dibutylamino, lithium dihexylamino, etc. Among these, lithium dibutylamino and lithium dihexylamino are preferred, and lithium dibutylamino is more preferred.

[0323] In the above equation (1), in R 10 and R 11 When the bonds combine with the adjacent nitrogen atoms to form a cyclic structure, examples of organolithium compounds represented by the above formula (1) include, but are not limited to, lithium piperidinium, lithium hexamethyleneimino, lithium azirmonocyclooctane, lithium-1,3,3-trimethyl-6-azabicyclo[3.2.1]octane, 1,2,3,6-tetrahydropiperidinium, 3,5-dimethylpiperidinium, etc.

[0324] Organolithium compounds having at least one nitrogen atom in their molecule are not limited to these, but include their analogues if the above conditions are met. From the aspects of the solubility of the polymerization initiator in the solvent, the reduction of the unpleasant odor of the modified conjugated diene polymer described later, and the inhibition of chain transfer reactions, piperidinium lithium, hexamethyleneimino lithium, lithium azacyclooctane, and lithium-1,3,3-trimethyl-6-azabicyclo[3.2.1]octane are preferred, piperidinium lithium, hexamethyleneimino lithium, and 3,5-dimethylpiperidinium lithium are more preferred, and piperidinium lithium is even more preferred.

[0325] In equation (2) above, R 14The term refers to alkylene polymers having aliphatic or aromatic substituents, or conjugated diene polymers having 1 to 30 carbon atoms, or conjugated diene polymers having 1 to 20 carbon atoms. These conjugated diene polymers preferably refer to polymers in which a conjugated diene compound having 4 to 12 carbon atoms is used as the repeating unit. Examples of conjugated diene compounds include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 3-methyl-1,3-pentadiene, 1,3-hexadiene, and 1,3-heptadiene. Among these, 1,3-butadiene and isoprene are preferred from the perspective of ease of industrial acquisition. They can be used alone or in combination of two or more.

[0326] In equation (2) above, R 14 In the case of alkylene groups having 1 to 30 carbon atoms, R is considered from the perspective of reactivity and interaction with inorganic fillers such as carbon and silicon dioxide. 14 Preferably, it represents an alkylene group having 2 to 20 carbon atoms; more preferably, it represents an alkylene group having 3 to 16 carbon atoms. Additionally, R... 14 When representing an alkylene group having 1 to 30 carbon atoms, examples of organolithium compounds represented by formula (2) include, but are not limited to, (3-(dimethylamino)-propyl)lithium, (3-(diethylamino)-propyl)lithium, (3-(dipropylamino)-propyl)lithium, (3-(dibutylamino)-propyl)lithium, (3-(dipentylamino)-propyl)lithium, (3-(dihexylamino)-propyl)lithium, (3-(dioctylamino)-propyl)lithium, (3-(ethylhexylamino)-propyl)lithium, (3-(didecylamino)-propyl)lithium, (3-(ethylpropylamino)-propyl)lithium, (3-(ethylbutyl)-propyl)lithium, (3-(ethylbutyl)-propyl)lithium, (3-(diethylpropylamino)-propyl)lithium, (3-(ethylbutyl)-propyl)lithium, (3-(dimethylamino ... Lithium (amino-propyl), lithium (3-(ethylbenzylamino)-propyl), lithium (3-(methylphenylethylamino)-propyl), lithium (4-(dibutylamino)-butyl), lithium (5-(dibutylamino)-pentyl), lithium (6-(dibutylamino)-hexyl), lithium (10-(dibutylamino)-decyl), lithium (5-(dibutylamino)-1-phenylpentyl), lithium (5-(dibutylamino)-1,1-diphenylpentyl), lithium (3-N,N-bistrimethylsilylaminopropyl), lithium (4-N-trimethylsilyl-N-methylaminobutyl), lithium (6-N-trimethylsilyl-N-butylaminohexyl), etc.

[0327] Organolithium compounds having at least one nitrogen atom in their molecule are not limited to these, but include their analogues if the above conditions are met. From the perspective of reactivity and interaction with inorganic fillers such as carbon and silicon dioxide, (3-(dibutylamino)-propyl)lithium is more preferred.

[0328] In equation (2) above, R 14In the case of conjugated diene polymers, examples of organolithium compounds represented by formula (2) include, but are not limited to, (4-(dimethylamino)-2-butenyl)lithium, (4-(diethylamino)-2-butenyl)lithium, (4-(dibutylamino)-2-butenyl)lithium, (4-(dipropylamino)-2-butenyl)lithium, (4-(diheptylamino)-2-butenyl)lithium, (4-(dihexylamino)-2-butenyl)lithium, (4-(dioctylamino)-2-butenyl)lithium, and (4-(dioctylamino)-2-butenyl)lithium. (4-(di-2-ethylhexylamino)-2-butenyl)lithium, (4-(didecylamino)-2-butenyl)lithium, (4-(ethylpropylamino)-2-butenyl)lithium, (4-(ethylbutylamino)-2-butenyl)lithium, (4-(ethylbenzylamino)-2-butenyl)lithium, (4-(methylphenylethylamino)-2-butenyl)lithium, (4-(dimethylamino)-2-methyl-2-butenyl)lithium, (4- (diethylamino)-2-methyl-2-butenyl)lithium, (4-(dibutylamino)-2-methyl-2-butenyl)lithium, (4-(dipropylamino)-2-methyl-2-butenyl)lithium, (4-(diheptylamino)-2-methyl-2-butenyl)lithium, (4-(dihexylamino)-2-methyl-2-butenyl)lithium, (4-(dimethylamino)-3-methyl-2-butenyl)lithium, (4-(diethylamino)-3-methyl-2-butenyl)lithium Lithium, (4-(dibutylamino)-3-methyl-2-butenyl)lithium, (4-(dipropylamino)-3-methyl-2-butenyl)lithium, (4-(diheptylamino)-3-methyl-2-butenyl)lithium, (4-(dihexylamino)-3-methyl-2-butenyl)lithium, the reaction product of 1 mole of piperidinyllithium with 3 moles of 1,3-butadiene, the reaction product of 3-N,N-bistrimethylsilylaminopropyllithium with 3 moles of 1,3-butadiene, etc.

[0329] Organolithium compounds having at least one nitrogen atom within their molecule are not limited to these; analogues thereof are included if the above conditions are met. From the perspective of reactivity as an initiator and control of the chain transfer reaction described later, 4-(dimethylamino)-2-butenyl)lithium, (4-(diethylamino)-2-butenyl)lithium, and (4-(dibutylamino)-2-butenyl)lithium are preferred, with (4-(dibutylamino)-2-butenyl)lithium being more preferred.

[0330] In equation (2), R 12 and R 13When the bonds combine with adjacent nitrogen atoms to form a cyclic structure, examples of organolithium compounds represented by formula (2) include (3-(piperidinyl)propyl)lithium, (3-(hexamethyleneimino)propyl)lithium, (3-(heptamethyleneimino)propyl)lithium, (3-(octamethyleneimino)propyl)lithium, (3-(1,3,3-trimethyl-6-azabicyclo[3.2.1]octyl)propyl)lithium, (3-(1,2,3,6-tetrahydropyridinyl)propyl)lithium, (2-(hexamethyleneimino)ethyl)lithium, (4-(hexamethyleneimino)butyl)lithium, (5-(hexamethyleneimino)pentyl)lithium, (6-(hexamethyleneimino)ethyl)lithium, and (3-(hexamethyleneimino)ethyl)lithium. (Imimyl)hexyl)lithium, (10-(hexamethyleneimino)decyl)lithium, (4-(piperidinyl)-2-butenyl)lithium, (4-(hexamethyleneimino)-2-butenyl)lithium, (4-(heptamethyleneimino)-2-butenyl)lithium, (4-(octamethyleneimino)-2-butenyl)lithium, (4-(1,3,3-trimethyl-6-azabicyclo[3.2.1]octyl)-2-butenyl)lithium, (4-(1,2,3,6-tetrahydropyridyl)-2-butenyl)lithium, (4-(hexamethyleneimino)-2-methyl-2-butenyl)lithium, (4-(hexamethyleneimino)-3-methyl-2-butenyl)lithium, etc.

[0331] Organolithium compounds having at least one nitrogen atom within their molecule are not limited to these, and analogues thereof are included if the above conditions are met. From the perspective of reactivity and interaction with inorganic fillers such as carbon and silicon oxide, and from the perspective of controlling the chain transfer reaction described later, (3-(piperidinyl)propyl)lithium, (3-(hexamethyleneimino)propyl)lithium, (3-(1,2,3,6-tetrahydropyridinyl)propyl)lithium, (4-(piperidinyl)-2-butenyl)lithium, and (4-(hexamethyleneimino)-2-butenyl)lithium are preferred, (3-(hexamethyleneimino)propyl)lithium, (4-(piperidinyl)-2-butenyl)lithium, and (4-(hexamethyleneimino)-2-butenyl)lithium are even more preferred, and (4-(piperidinyl)-2-butenyl)lithium is even more preferred.

[0332] In equation (3), R 12 and R 13 R in equation (2) 12 and R 13 Same. The organolithium compound represented by formula (3) having at least one nitrogen atom in the molecule can be a product of the reaction between an organic monolithium compound and an organic unsaturated compound having a substituted amino group.

[0333] In this case, R 20 R is an organic group derived from an organolithium compound. 19This refers to alkylene compounds derived from organic unsaturated compounds having substituted amino groups. In the case of organic monolithium compounds having substituted amino groups, R... 20 The substituted amino group is a hydrocarbon group. Known organic unsaturated compounds with substituted amino groups that undergo addition reactions via lithium-based initiators include vinyl aromatic compounds with substituted amino groups and conjugated diene compounds with substituted amino groups.

[0334] Organolithium compounds having at least one nitrogen atom in the molecule, represented by formula (3), can be exemplified but are not limited to, for example, 1-(4-N,N-dimethylaminophenyl)hexyllithium, 1-(4-N,N-dimethylaminophenyl)-1-phenylhexyllithium, 1-(4-N,N-dimethylaminomethylphenyl)hexyllithium, 1-(4-N,N-bis(trimethylsilylaminophenyl)hexyllithium, 1-(4-N-trimethylsilyl-N-ethylaminophenyl)hexyllithium, 1-(4-N,N-bis(trimethylsilylaminophenyl)-1-phenylhexyllithium, 1-(4- The reaction products of N,N-dimethylaminophenyl)-4-methylpentyllithium, 1 mole of butyllithium and 2 moles of 4-N,N-dimethylaminostyrene, 1 mole of sec-butyllithium and 4 moles of 4-N,N-bistrimethylsilylaminostyrene, 1 mole of butyllithium and 4 moles of 2-N,N-dimethylamino-1,3-butadiene, 1 mole of piperidinyllithium and 2 moles of 4-N,N-dimethylaminostyrene, and 3-N,N-bistrimethylsilylaminopropyllithium and 2 moles of 4-N,N-dimethylaminostyrene, etc.

[0335] Examples of organolithium compounds having at least one nitrogen atom in the molecule, as represented by formula (4) above, include the reaction products of N-substituted o-toluidine compounds with alkyl lithium.

[0336] As an organolithium compound having at least one nitrogen atom in the molecule as represented by formula (4), examples, but not limited to, include, for example, lithium N,N-dimethyl-o-toluamide, lithium N,N-dimethyl-m-toluamide, lithium N,N-dimethyl-p-toluamide, lithium N,N-diethyl-o-toluamide, lithium N,N-diethyl-m-toluamide, lithium N,N-diethyl-p-toluamide, lithium N,N-dipropyl-o-toluamide, lithium N,N-dipropyl-m-toluamide, lithium N,N-dipropyl-p-toluamide, lithium N,N-dibutyl-o-toluamide, lithium N,N-dibutyl-m-toluamide, lithium N,N-dibutyl-p-toluamide, lithium o-piperidinyltoluyl, lithium p-piperidinyl... Lithium methyltoluene, lithium o-pyrrolyltoluene, lithium p-pyrrolyltoluene, lithium N,N,N',N'-tetramethyltoluenediaminolithium, lithium N,N,N',N'-tetraethyltoluenediaminolithium, lithium N,N,N',N'-tetrapropyltoluenediaminolithium, lithium N,N-dimethylxyltoluenediaminolithium, lithium N,N-diethylxyltoluenediaminolithium, lithium N,N-dipropylxyltoluenediaminolithium, lithium N,N-dimethyltrimethyltoluenediaminolithium, lithium N,N-diethyltrimethyltoluenediaminolithium, lithium (N,N-dimethylamino)toluylphenylmethylaminolithium, lithium 1-(N,N-dimethylamino)-2-methylnaphthyllithium, lithium 1-(N,N-dimethylamino)-2-methylanthrayllithium, etc.

[0337] Organolithium compounds having at least one nitrogen atom within their molecule are not limited to these; analogues thereof are included if the above conditions are met. From the perspective of polymerization activity, lithium N,N-dimethyl-o-toluamide is more preferred.

[0338] Examples of organolithium compounds having at least one nitrogen atom in the molecule as represented by formula (4) include, but are not limited to, 2-(2-methylpiperidinyl)-1-ethyllithium (e.g., trade name “AI-250” manufactured by FMC).

[0339] Organolithium compounds are not limited to these; analogues thereof are included if the above conditions are met.

[0340] Before the polymerization process, an organolithium compound or other organolithium compound having at least one nitrogen atom in the molecule can be prepared in advance, and all known methods can be applied.

[0341] In the above polymerization process, when obtaining a nitrogen-containing conjugated diene polymer, a process of copolymerizing at least a conjugated diene compound and a copolymerizable monomer having at least one nitrogen atom in the molecule can be carried out in the presence of an organolithium compound.

[0342] As a copolymerizable monomer having at least one nitrogen atom in the molecule, a known organic unsaturated compound having substituted amino groups is used, which is copolymerized with a conjugated diene compound by a lithium-based initiator, including vinyl aromatic compounds having substituted amino groups and conjugated diene compounds having substituted amino groups.

[0343] Organolithium compounds are preferably organomonolithium compounds, which may or may not have substituted amino groups in the molecule. Alkyl lithium compounds are preferred from the perspectives of ease of industrial acquisition and ease of controlling the polymerization reaction. In this case, conjugated diene polymers with alkyl groups at the polymerization initiation terminal can be obtained.

[0344] Examples of alkyl lithium compounds include, but are not limited to, n-butyllithium, sec-butyllithium, tert-butyllithium, n-hexyllithium, benzyllithium, phenyllithium, and mesodephenylethylenelithium. From the perspectives of ease of industrial acquisition and ease of controlling the polymerization reaction, n-butyllithium and sec-butyllithium are preferred as alkyl lithium compounds.

[0345] As a substituted amino group, the amino group in which each hydrogen atom is independently replaced by at least one group selected from the group consisting of an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, and an aralkyl group having 6 to 20 carbon atoms, and a protecting group. The substituent can bond and form a cyclic structure with the adjacent nitrogen atom. In this case, the substituent represents an alkyl group having 5 to 12 carbon atoms, and a portion of it may have unsaturated bonds or a branched structure. It should be noted that, as a protecting group, alkyl-substituted silyl groups are preferred.

[0346] From the perspective of obtaining the conjugated diene polymer of this embodiment reliably and easily, the polymerization branching process is preferably carried out in an inert solvent. Examples of such inert solvents include, but are not limited to, hydrocarbon solvents such as saturated hydrocarbons and aromatic hydrocarbons. Specific examples of hydrocarbon solvents 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; hydrocarbons composed of mixtures thereof; and so on.

[0347] From the perspective of obtaining a conjugated diene polymer formed by the random polymerization of a conjugated diene compound and a vinyl aromatic compound, the polymerization reaction in the polymerization branching process can be carried out using, for example, the method described in Japanese Patent Application Publication No. 59-140211. That is, the following method can be used: first, the polymerization reaction is initiated using the total amount of the vinyl aromatic compound and a portion of the conjugated diene compound, and then the remaining conjugated diene compound is intermittently added during the polymerization reaction.

[0348] The polymerization temperature in the polymerization reaction of the polymerization branching process is not particularly limited, but the temperature for living anionic polymerization is preferred. Furthermore, from the perspective of improving productivity, 0°C or higher is more preferred, and 0°C or higher but 120°C or lower is even more preferred. By keeping the polymerization temperature in the polymerization reaction within the above range, there is a tendency to sufficiently improve the reactivity with the coupling modifier in the coupling process described later. From the same perspective, the polymerization temperature in the polymerization reaction is even more preferred to be 50°C or higher but 100°C or lower.

[0349] Polar compounds can be added during the polymerization branching process. With the addition of polar compounds, there is a tendency to obtain conjugated diene polymers that have undergone further random copolymerization of vinyl aromatic compounds and conjugated diene compounds. Thus, polar compounds have an effective randomizing effect in the copolymerization of conjugated diene compounds and vinyl aromatic compounds, and can therefore be used as distribution modifiers for vinyl aromatic compounds and as modifiers for the amount of styrene blocks. Furthermore, polar compounds can promote the polymerization reaction and can also be used as vinylizing agents to control the microstructure of conjugated diene polymers.

[0350] Thus, since polar compounds are used as vinylizing agents, atactic agents, and polymerization accelerators, the polymerization accelerating effect tends to decrease, for example, when the amount of polar compounds is reduced to adjust the vinylization rate and atacticity rate. Therefore, in methods that adjust the branching degree of a polymer by reacting a coupling modifier with the polymerization termination end, reducing the amount of polar compound increases the polymerization time and the proportion of deactivated polymerization termination ends. As a result, such methods tend to have difficulty improving the modification rate. That is, when it is desired to adjust the branching degree of modified conjugated diene polymers by adjusting the amount of polar compound added and by using a coupling modifier, it tends to have difficulty controlling the vinylization rate and atacticity rate. Regarding this, in the manufacturing method of this embodiment, since the branching degree of the polymer can be increased using the branching agent described later, the branching degree can be controlled independently of the vinylization rate and atacticity rate, which is advantageous in the structural design of conjugated diene polymers.

[0351] Examples of polar compounds include, 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, dipiperidinyl ethane, trimethylamine, triethylamine, pyridine, and quinine ring; alkali metal alkoxides such as potassium tert-pentoxide, potassium tert-butoxide, sodium tert-butoxide, and sodium pentanol; and phosphine compounds such as triphenylphosphine. These polar compounds can be used alone or in combination of two or more.

[0352] The amount of polar compound added is not particularly limited and can be adjusted according to the amount of the polymerization active end, i.e., the amount of polymerization initiator added. For example, the amount of polar compound added relative to 1 mole of polymerization initiator is preferably 0.010 mol to 1.0 mol, more preferably 0.10 mol to 0.70 mol. Within the above range, the amount of polar compound added relative to 1 mole of polymerization initiator can also be 0.60 mol or less or 0.50 mol or less. Alternatively, it can be 0.15 mol or more or 0.20 mol or more relative to 1 mole of polymerization initiator. When the amount of polar compound added is below the above upper limit, there is a tendency to obtain conjugated diene polymers with low Tg. Furthermore, 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 a range formed by any combination of the above upper and lower limits.

[0353] In the method for manufacturing the modified conjugated diene polymer of this embodiment, an impurity removal step may be included before the polymerization branching step. Particularly when the monomer, polymerization initiator, and / or inert solvent contain propylene or acetylene as impurities, an impurity removal step before the polymerization branching step is preferred. By including the impurity removal step, it is preferable to obtain a modified conjugated diene polymer with a high concentration of active terminals, and a modified conjugated diene polymer with a high modification rate is preferable in the coupling step described later. There are no particular limitations on such an impurity removal step; for example, a step using an organometallic compound can be used. There are no particular limitations on such organometallic compounds; for example, organolithium compounds can be used. There are no particular limitations on organolithium compounds; for example, n-butyllithium can be used.

[0354] In the polymerization branching process, a branching reaction is initiated in the modified conjugated diene polymer by adding a branching agent (described later). After the addition of the branching agent, both the polymerization reaction for the growth of the modified conjugated diene polymer and the branching reaction for the branching of the modified conjugated diene polymer competitively occur in the reaction system. Therefore, the weight-average molecular weight, number-average molecular weight, their ratio (Mw / Mn), and absolute molecular weight of the modified conjugated diene polymer obtained in the polymerization branching process, as well as the degree of branching, the number of branching points, and the number of branches at each branching point, can be controlled by the type and amount of branching agent added, as well as the timing of the addition of the branching agent.

[0355] Furthermore, by adding a branching agent to the polymerization of modified conjugated diene polymers, the total amount of active ends of the conjugated diene polymer in the reaction system can be reduced compared to the amount of polymerization initiator added. Even with a reduction in the amount of added polar compounds, the reaction can be promoted in the early stages of polymerization, and the activity of the polymeric active ends can be maintained. As a result, for the conjugated diene polymer of this embodiment, where the amount of bonded vinyl aromatic compounds and the amount of vinyl bonds are within the specific ranges described above, the coupling rate and / or modification rate of the polymerization termination ends can be easily improved. However, the conjugated diene polymer of this embodiment does not necessarily need to react with the coupling modifier.

[0356] As described above, in the method for manufacturing the modified conjugated diene polymer of this embodiment, the amount of polar compound added can be adjusted to control the microstructure, such as the amount of bonded vinyl aromatic compounds and the amount of vinyl bonds. When the amount of polar compound added is typically used to bring the amount of bonded vinyl aromatic compounds and the amount of vinyl bonds into the aforementioned specific range, it is insufficient to maintain the active ends of the conjugated diene polymer in the reaction system without the addition of a branching agent, and it is not easy to sufficiently maintain the activity of the polymerization active ends. Furthermore, with such an amount of polar compound added, the randomization ability of the vinyl aromatic compounds and the conjugated diene compounds is not high enough, and in the conjugated diene polymer of this embodiment where the amount of bonded vinyl aromatic compounds and the amount of vinyl bonds are within the aforementioned specific range, there is a tendency for the polymerization ends to become vinyl aromatic compounds. Under such conditions, it is difficult to obtain conjugated diene polymers with high coupling rates or modification rates.

[0357] In other words, in the method for manufacturing modified conjugated diene polymers according to this embodiment, since a branching agent is used, even if the amount of a polar compound that is not usually easy to maintain the activity of the polymer active ends is added, the active ends of the polymer can be maintained sufficiently, and a high coupling rate and modification rate can be achieved.

[0358] There is no particular limitation on the timing of adding the branching agent in the branching process; it can be appropriately selected according to the intended use of the conjugated diene polymer being manufactured.

[0359] From the perspective of increasing the absolute molecular weight of the obtained conjugated diene polymer and improving the modification rate in the coupling process, the branching agent is preferably added when the raw material conversion rate after the addition of the polymerization initiator is 20% or more, more preferably 40% or more, further preferably 50% or more, even more preferably 65% ​​or more, and even more preferably 75% or more. That is, the branching agent is preferably added when the polymerization reaction is sufficiently stable. By ensuring that the branching agent is added within the above range, even if the amount of polar compound added is small or not added at all, a conjugated diene polymer with a higher modification rate can be obtained in the coupling process.

[0360] There are no particular limitations on the branching agent; for example, compounds represented by formula (10) or formula (11) can be used.

[0361] [Chemistry 24]

[0362] [Chemistry 25]

[0363] (In equation (10), R) 1 It represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and a portion thereof may have a branched structure.

[0364] R 2 ~R 3 Each can independently represent an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and some of them may have a branched structure.

[0365] R in the case of a complex number 1 ~R 3 Each is independent.

[0366] X 1 This represents an independent halogen atom.

[0367] m represents an integer from 0 to 2, n represents an integer from 0 to 3, and l represents an integer from 0 to 3.

[0368] (m+n+l) represents 3.

[0369] (In equation (11), R) 4 ~R 7 Each can independently represent an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and some of them may have a branched structure.

[0370] R in the case of a complex number 4 ~R 7 Each is independent.

[0371] X 2 ~X 3 This represents an independent halogen atom.

[0372] m represents an integer from 0 to 2, n represents an integer from 0 to 3, and l represents an integer from 0 to 3.

[0373] (m+n+l) represents 3.

[0374] 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.

[0375] In this embodiment, from the perspective of polymerization sustainability and increasing branching degree, the branching agent used to construct the main chain branching structure of the conjugated diene polymer is preferably R of the above formula (10). 1 A compound consisting of hydrogen atoms with m=0.

[0376] In addition, in this embodiment, from the perspective of improving the degree of branching, the branching agent used when constructing the main chain branch structure of the conjugated diene polymer is preferably a compound in formula (11) above where m=0 and b=0.

[0377] Furthermore, in this embodiment, from the perspectives of polymerization sustainability, improved modification rate, and branching degree, the branching agent used to construct the main chain branching structure of the conjugated diene polymer is more preferably R of the above formula (10). 1 Compounds consisting of hydrogen atoms, m=0, l=0.

[0378] In addition, in this embodiment, from the perspective of improving the modification rate and branching degree, the branching agent used to construct the main chain branching structure of the conjugated diene polymer is further preferably a compound with m=0, l=0, a=0, and b=0 in the above formula (11).

[0379] Furthermore, in this embodiment, from the perspectives of polymerization sustainability, improved modification rate, and branching degree, the branching agent used to construct the main chain branching structure of the conjugated diene polymer is more preferably R in the above formula (10). 1 A compound consisting of hydrogen atoms, l=0, n=3.

[0380] Examples of branching agents represented by formula (10) above 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, and trimethoxy(2-vinylphenyl)silane. Alkane, 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 Dimethylphenyl silane, dibutoxymethyl (3-vinylphenyl)silane, diisopropoxymethyl (3-vinylphenyl)silane, dimethoxymethyl (2-vinylphenyl)silane, diethoxymethyl (2-vinylphenyl)silane, dipropoxymethyl (2-vinylphenyl)silane, dibutoxymethyl (2-vinylphenyl)silane, diisopropoxymethyl (2-vinylphenyl)silane, dimethylmethoxy (4-vinylphenyl)silane, dimethylethoxy (4-vinylphenyl)silane, dimethylpropoxy (4-vinylphenyl)silane, dimethylbutoxy (4-vinylphenyl)silane Silanes, including 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, and dimethylisopropoxy(2-vinylphenyl)silane.

[0381] In addition, examples of branching agents represented by the above 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, and 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, dipropoxymethyl(3-isopropenylphenyl)silane, dibutoxymethyl(3-isopropenylphenyl)silane, diisopropoxymethyl(3-isopropenylphenyl)silane, diisopropoxymethyl(3-isopropenylphenyl)silane, dimethoxymethyl(2-isopropenylphenyl)silane, diethyl... 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, etc.

[0382] 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 more preferably trimethoxy(4-vinylphenyl)silane, triethoxy(4-vinylphenyl)silane, tripropoxy(4-vinylphenyl)silane, tributoxy(4-vinylphenyl)silane, and triisopropoxy(4-vinylphenyl)silane.

[0383] Examples of branching agents represented by formula (11) above 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-tripropoxysilylphenyl)ethylene, 1,1-bis(3-tripentoxysilylphenyl)ethylene, 1,1-bis(3-triisopropoxysilylphenyl)ethylene, 1,1-bis(2-tri ... 1,1-bis(2-triethoxysilylphenyl)ethylene, 1,1-bis(3-tripropoxysilylphenyl)ethylene, 1,1-bis(2-tripentoxysilylphenyl)ethylene, 1,1-bis(2-triisopropoxysilylphenyl)ethylene, 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, etc.

[0384] 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.

[0385] The amount of such branching agent added is not particularly limited and can be appropriately selected according to the intended use of the target conjugated diene polymer. It is preferably 0.020 moles or more and 0.50 moles or less, more preferably 0.025 moles or more and 0.40 moles or less, and even more preferably 0.030 moles or more and 0.25 moles or less, relative to 1 mole of the polymerization initiator.

[0386] The amount of branching agent added can be 0.040 moles or more or 0.045 moles or more relative to 1 mole of the polymerization initiator within the above range. Alternatively, it can be 0.20 moles or less or 0.18 moles or less relative to 1 mole of the polymerization initiator.

[0387] The amount of branching agent added can be set within any combination of the above upper and lower limits. The amount of branching agent added affects the overall branching degree of the polymer; if the amount added increases, the overall branching degree and the branching degree at extreme values ​​will increase.

[0388] In the polymerization branching process, the reaction temperature can be changed or not after adding a branching agent.

[0389] In the polymerization branching process, after adding the branching agent, the monomer of the conjugated diene polymer can be added, or the branching agent can be added again afterward, or the branching agent and monomer can be added repeatedly.

[0390] There are no particular limitations on the added monomers. From the perspective of improving the modification rate in the coupling process, it is preferable to add the same monomers as those initially added as monomers in the polymerization branching process.

[0391] The amount of the added monomer can be 1.0% or more, 5.0% or more, 10.0% or more, 15.0% or more, or 20.0% or more of the total amount of monomer used as a conjugated diene polymer. Alternatively, the amount of the added monomer can be 50.0% or less, 40.0% or less, or 35.0% or less.

[0392] If the amount of added monomer is within the above range, the molecular weight between the branch points generated by adding the branching agent and the branch points generated by adding the coupling modifier increases, thus tending to easily obtain a molecular structure with high linearity. By making the obtained conjugated diene polymer have such a structure, the entanglement between the molecular chains of the conjugated diene polymer increases after it is made into a sulfide, tending to easily obtain a sulfide with excellent wear resistance, handling stability and breaking strength.

[0393] (Coupled process)

[0394] In the method for manufacturing the conjugated diene polymer of this embodiment, it is preferable to react the branched conjugated diene polymer obtained through the above-described polymerization branching step with a coupling modifier to produce a modified conjugated diene polymer. Through this coupling step, the branched conjugated diene polymer obtained through the polymerization branching step can be modified using nitrogen-containing functional groups that have affinity or bonding reactivity with filler materials. Furthermore, multiple conjugated diene polymers can be coupled together. Therefore, this manufacturing method with a coupling step can more reliably and easily obtain the conjugated diene polymer of this embodiment.

[0395] As a coupling modifier, there are no particular limitations on any reactive compound that has a nitrogen-containing functional group that has affinity or bonding reactivity with the filler material, or has two or more functional groups that can react with the active ends of conjugated diene polymers.

[0396] Examples of such coupling modifiers include coupling modifiers containing nitrogen atoms, and further, coupling modifiers containing nitrogen atoms and silicon atoms.

[0397] Examples of coupling modifiers having nitrogen-containing groups include, but are not limited to, isocyanate compounds, isothiocyanate compounds, isocyanuric acid derivatives, carbonyl compounds containing nitrogen atoms, vinyl compounds containing nitrogen atoms, epoxy compounds containing nitrogen atoms, imine compounds, and alkoxysilane compounds containing nitrogen atoms.

[0398] Preferred coupling modifiers having nitrogen-containing groups include amine compounds without active hydrogen, protected amine compounds where the active hydrogen is substituted by a protecting group, imine compounds represented by the general formula -N=C, and alkoxysilane compounds bonded to these nitrogen-containing compounds. Tertiary amine compounds are examples of amine compounds without active hydrogen.

[0399] Examples of isocyanate compounds 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, 1,3,5-phenyltriisocyanate, etc.

[0400] Examples of isothiocyanate compounds 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-phenyltriisothiocyanate.

[0401] Examples of 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(ethyleneoxy-2-yl)-1,3,5-triazinane-2,4,6-trione, 1,3,5-tris(isocyanate methyl)-1,3,5-triazinane-2,4,6-trione, and 1,3,5-trivinyl-1,3,5-triazinane-2,4,6-trione.

[0402] Examples of carbonyl compounds containing nitrogen atoms include, but are not limited to, 1,3-dimethyl-2-imidazolinone, 1-methyl-3-ethyl-2-imidazolinone, 1-methyl-3-(2-methoxyethyl)-2-imidazolinone, N-methyl-2-pyrrolidone, N-methyl-2-piperidinone, N-methyl-2-quinolone, 4,4'-bis(diethylamino)benzophenone, 4,4'-bis(dimethylamino)benzophenone, and 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, N,N-diethylcarbamate, N,N-diethylacetamide, N,N-dimethyl-N',N'-dimethylaminoacetamide, N,N-dimethylpyridinecarboxamide, N,N-dimethylisonicotinamide, etc.

[0403] Examples of vinyl compounds containing nitrogen atoms include, but are not limited to, N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, N-methylmaleimide, N-methylphthalimide, N,N-bis(trimethylsilyl)acrylamide, morpholinoacrylamide, 3-(2-dimethylaminoethyl)styrene, (dimethylamino)dimethyl-4-vinylphenylsilane, 4,4'-vinylbis(N,N-dimethylaniline), 4,4'-vinylbis(N,N-diethylaniline), 1,1-bis(4-morpholinophenyl)ethylene, 1-phenyl-1-(4-N,N-dimethylaminophenyl)ethylene, etc.

[0404] Examples of epoxide compounds containing nitrogen atoms include, but are not limited to, hydrocarbon compounds containing an epoxide group bonded to an amino group.

[0405] Furthermore, the aforementioned hydrocarbon compounds may further have an epoxy group bonded to an ether group. Examples of such nitrogen-containing epoxy compounds include, but are not limited to, compounds represented by, for example, formula (12).

[0406] [Chemistry 26]

[0407] In the above formula (12), R is a hydrocarbon group with a valence of 2 or more or an organic group with a polar group with a valence of 2 or more. The polar group is selected from at least one of the following: ether, epoxy, ketone and other polar groups with oxygen; thioether, thioketone and other polar groups with sulfur; tertiary amino, imino and other polar groups with nitrogen.

[0408] The alkyl group with a valence of 2 or higher can be saturated or unsaturated, and can be straight-chain, branched, or cyclic, including alkylene, alkenylene, and phenylene. Alkyl groups with 1 to 20 carbon atoms are preferred. Examples include methylene, ethylene, butylene, cyclohexylene, 1,3-bis(methylene)-cyclohexane, 1,3-bis(ethylene)-cyclohexane, o-phenylene, m-phenylene, p-phenylene, m-xylene, p-xylene, and bis(phenylene)-methane.

[0409] In the above formula (12), R 24 R 27 R is a hydrocarbon group with 1 to 10 carbon atoms. 24 R 27 They can be the same or different.

[0410] In the above formula (12), R 25 R 28 R is a hydrogen or hydrocarbon group having 1 to 10 carbon atoms. 25 R 28 They can be the same or different.

[0411] In the above formula (12), R 26 It is a hydrocarbon group with 1 to 10 carbon atoms, or the structure of the following formula (13).

[0412] R 24 R 25 R 26 It can be a ring structure formed by mutual bonding.

[0413] Additionally, R 26 In the case of a hydrocarbon group, it can be a cyclic structure formed by bonding with R. In the case of the above-mentioned cyclic structure, it can be bonded to R. 26 The N and R are directly bonded.

[0414] 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 or 1.

[0415] [Chemistry 27]

[0416] In the above formula (13), R 29 R 30 R in equation (12) above 24 R 25 Similarly defined, R 29 R 30 They can be the same or different.

[0417] As a nitrogen-containing epoxy compound, it is preferred to be a nitrogen-containing epoxy compound having one or more diglycidylamino groups and one or more epoxypropoxy groups in the molecule.

[0418] Examples of nitrogen-containing epoxy compounds include, but are not limited to, N,N-diglycidyl-4-epoxypropoxyaniline, 1-N,N-diglycidylaminomethyl-4-epoxypropoxy-cyclohexane, 4-(4-epoxypropoxyphenyl)-(N,N-diglycidyl)aniline, 4-(4-epoxypropoxyphenoxy)-(N,N-diglycidyl)aniline, 4-(4-epoxypropoxybenzyl)-(N,N-diglycidyl)aniline, 4-(N,N'-diglycidyl-2-piperazinyl)-epoxypropoxybenzene, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, and 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-diglycidylo-toluidine, N,N-diglycidylaminomethylcyclohexane, etc.

[0419] Among these preferred options are N,N-diglycidyl-4-epoxypropoxyaniline and 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane.

[0420] Examples of imine compounds include, but are 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-imylamino)ethyl]amine, tris[2-(propane-2-imylamino)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-phenylmethaneimine), and N,N'-(hexane-1,6-diyl)bis(1-phenylmethaneimine).

[0421] Examples of alkoxysilane compounds containing nitrogen atoms include, but are 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, and 1-[3-(triethoxysilyl)propyl]-3-methylhexahydrosilane. Pyrimidine, 3-(4-trimethylsilyl-1-piperazinyl)propyltriethoxysilane, 3-(3-triethylsilyl-1-imidazolyl)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, tri(trimethoxysilyl)amine Tris(3-trimethoxysilylpropyl)amine, N,N,N',N'-tetra(3-trimethoxysilylpropyl)ethylenediamine, 3-isocyanopropyltrimethoxysilane, 3-cyanopropyltrimethoxysilane, 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silazopentane, 2,2-diethoxy-1-(3-triethoxysilylpropyl)-1-aza-2-silazopentane, 2,2-dimethoxy-1-(4-trimethoxysilylbutyl)-1-aza-2-silazopentane, 2,2-di- Methoxy-1-(3-dimethoxymethylsilylpropyl)-1-aza-2-silazopentane, 2,2-dimethoxy-1-phenyl-1-aza-2-silazopentane, 2,2-diethoxy-1-butyl-1-aza-2-silazopentane, 2,2-dimethoxy-1-methyl-1-aza-2-silazopentane, 2,2-dimethoxy-8-(4-methylpiperazinyl)methyl-1,6-dioxa-2-silazopentane, 2,2-dimethoxy-8-(N,N-diethylamino)methyl-1,6-dioxa-2-silazopentane, etc.

[0422] Preferred alkoxysilane compounds containing nitrogen atoms 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-silazopentanyl)propyl]amine, tetra(3-trimethoxysilylpropyl)-1,3-propanediamine (also known as "N,N,N',N'-tetra(3-trimethoxysilylpropyl)-1,3-propanediamine"), and tris(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-aza-2-azacyclopentane]]. [3-Propyl]-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-silacyclopentane)propyl]-[3-(1-ethoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, tetra(3-trimethoxysilylpropyl)-1,3-diaminomethylcyclohexane, tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-diaminomethylcyclohexane 3-Trimethoxysilylpropyl)-1,6-hexanediamine, penta(3-trimethoxysilylpropyl)-diethylenetriamine, tri(3-trimethoxysilylpropyl)-methyl-1,3-propanediamine, tetra[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl]silane, bis(3-trimethoxysilylpropyl)-bis[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl]silane, tri[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl]-(3-trimethoxysilylpropyl)silane, tri[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl]-[3 -(1-methoxy-2-trimethylsilyl-1-silaza-2-azacyclopentane)propyl]silane, 3-tris[2-(2,2-dimethoxy-1-aza-2-silazacyclopentane)ethoxy]silyl-1-trimethoxysilylpropane, 1-[3-(1-methoxy-2-trimethylsilyl-1-silaza-2-azacyclopentane)propyl]-3,4,5-tris(3-trimethoxysilylpropyl)cyclohexane, 1-[3-(2,2-dimethoxy-1-aza-2-silazacyclopentane)propyl]-3,4,5-tris(3-trimethoxysilylpropyl)cyclohexane, 3,4,5-tris(3-trimethoxysilylpropyl)cyclohexyl-[3-(2,2-dimethoxy-1-aza-2-silazacyclopentane)propyl]-3,4,5-tris(3-trimethoxysilylpropyl)cyclohexane, 3,4,5-tris(3-trimethoxysilylpropyl)cyclohexyl-[3-(2,2-Dimethoxy-1-aza-2-silazopentanyl)propyl ether, (3-trimethoxysilylpropyl) phosphate, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl] phosphate, bis[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl]-(3-trimethoxysilylpropyl) phosphate, tris[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl] phosphate, N-(1,3-dimethylbutylene)-3-(triethoxysilyl)-1-propylamine ... Examples of methylbenzyl-3-(trimethoxysilyl)-1-propane, N-benzyl-3-(triethoxysilyl)propane-1-amine, N-benzyl-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-(benzylaminoethyl)-1-aza-2-silazopentane, 2-methoxy-2-methyl-1-(4-methoxybenzylaminoethyl)-1-aza-2-silazopentane, etc.

[0423] Among coupling modifiers containing nitrogen atoms, protected amine compounds in which the active hydrogen is replaced by a protecting group can be exemplified by compounds having unsaturated bonds and a protected amine in the molecule. Examples of such compounds include, but are not limited to, 4,4'-vinylenebis[N,N-bis(trimethylsilyl)aniline], 4,4'-vinylenebis[N,N-bis(triethylsilyl)aniline], 4,4'-vinylenebis[N,N-bis(tert-butyldimethylsilyl)aniline], 4,4'-vinylenebis[N-methyl-N-(trimethylsilyl)aniline], 4,4'-vinylenebis[N-ethyl-N-(trimethylsilyl)aniline], and 4,4'-vinylenebis[N-methyl-N-(triethylsilyl)benzene]. [Amines], 4,4'-vinylbis[N-ethyl-N-(triethylsilyl)aniline], 4,4'-vinylbis[N-methyl-N-(tert-butyldimethylsilyl)aniline], 4,4'-vinylbis[N-ethyl-N-(tert-butyldimethylsilyl)aniline], 1-[4-N,N-bis(trimethylsilyl)aminophenyl]-1-[4-N-methyl-N-(trimethylsilyl)aminophenyl]ethylene, 1-[4-N,N-bis(trimethylsilyl)aminophenyl]-1-[4-N,N-dimethylaminophenyl]ethylene, etc.

[0424] Among coupling modifiers containing nitrogen atoms, protected amine compounds in which the active hydrogen is replaced by a protecting group can be exemplified by compounds containing alkoxysilane and a protected amine in the molecule.

[0425] 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, and N,N-bis(triethylsilyl)aminopropyltrimethoxysilane. 3-(4-trimethylsilyl-1-piperazinyl)propyltriethoxysilane, 3-(3-triethylsilyl-1-imidazolyl)propylmethyldiethoxysilane, 3-(3-trimethylsilyl-1-hexahydropyrimidinyl)propyltrimethoxysilane, 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silazolyl pentane, 2,2-diethoxy-1-(3-triethoxysilylpropyl)-1-aza-2-silazolyl pentane, 2,2-dimethoxy-1-(4-trimethylsilyl-1-piperazinyl)propyltriethoxysilane, 2,2-dimeth ...3-trimethylsilyl-1-piperazinyl)propyltriethoxysilane, 2,2-dimethoxy-1-(3-trimethylsilyl-1-piperazinyl)propyltriethoxysilane, 2,2-dimethoxy-1-(3-trimethylsilyl-1-piperazinyl)propyltriethoxysilane, 2,2-dimethoxy-1-(3-trimethylsilyl-1-piperazinyl)propyltriethoxysilane, 2,2-dimethoxy-1-(3 (1,3-Dimethylsilylbutyl)-1-aza-2-silazanehexane, 2,2-dimethoxy-1-(3-dimethoxymethylsilylpropyl)-1-aza-2-silazanepentane, 2,2-dimethoxy-1-phenyl-1-aza-2-silazanepentane, 2,2-diethoxy-1-butyl-1-aza-2-silazanepentane, 2,2-dimethoxy-1-methyl-1-aza-2-silazanepentane, N-(1,3-dimethylbutylene)-3-methyl(dimethoxysilyl)-1-propylamine, N-(1,3-dimethylbutylene) 3-Methyl(diethoxysilyl)-1-propane, N-(1-methylethylidene)-3-(triethoxysilyl)-1-propane, N-(1-methylethylidene)-3-(trimethoxysilyl)-1-propane, N-(1-methylethylidene)-3-methyl(diethoxysilyl)-1-propane, N-(1-methylethylidene)-3-methyl(diethoxysilyl)-1-propane, N-ethylidene-3-(triethoxysilyl)-1-propane, N-ethylidene-3-(trimethoxysilyl)-1-propane, etc.

[0426] Examples of other examples include N-ethylidene-3-methyl(dimethoxysilyl)-1-propane, N-ethylidene-3-methyl(diethoxysilyl)-1-propane, N-(1-methylpropylene)-3-(triethoxysilyl)-1-propane, N-(1-methylpropylene)-3-(trimethoxysilyl)-1-propane, and N-(1-methylpropylene)-3-methyl(dimethoxysilyl)-1-propane. Propylamine, N-(1-methylpropylidene)-3-methyl(diethoxysilyl)-1-propane, N-benzyl-3-methyl(diethoxysilyl)propane-1-amine, N-benzyl-3-methyl(diethoxysilyl)propane-1-amine, N-4-methylbenzyl-3-(triethoxysilyl)propane-1-amine, N-4-methylbenzyl-3-(trimethoxysilyl)propane-1-amine N-4-methylbenzyl-3-methyl(dimethoxysilyl)propane-1-amine, N-4-methylbenzyl-3-methyl(diethoxysilyl)propane-1-amine, N-naphthyl-3-(triethoxysilyl)propane-1-amine, N-naphthyl-3-(trimethoxysilyl)propane-1-amine, N-naphthyl-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-(benzylaminoethyl)-1-aza-2-silazopentane, 2-methoxy-2-methyl-1-(methylisobutylaminoethyl)-1-aza-2-silazopentane, etc.

[0427] In the coupling process, it is more preferable to use two or more alkoxysilane compounds containing nitrogen atoms represented by any one of the following formulas (14) to (18) as coupling modifiers.

[0428] As this coupling modifier, a coupling modifier having two or fewer alkoxysilyl groups can be used in combination with a coupling modifier having more than two alkoxysilyl groups.

[0429] [Chemistry 28]

[0430] In equation (14), R 8 ~R 10 It consists of hydrocarbon groups with 1 to 20 carbon atoms, which may have unsaturated bonds, and these bonds may be the same or different. 11 R 12 It consists of aliphatic hydrocarbon groups with 1 to 6 carbon atoms, which may have unsaturated bonds, and these bonds may be the same or different. 13It is a hydrocarbon group with 1 to 20 carbon atoms that can replace an organic group containing Si, O, or N and without active hydrogen, and can have unsaturated bonds. d is an integer from 1 to 3.

[0431] [Chemistry 29]

[0432] In equation (15), R 14 ~R 16 It consists of hydrocarbon groups with 1 to 20 carbon atoms, which can have unsaturated bonds, and these bonds can be the same or different.

[0433] R 17 R 18 It can be a hydrocarbon group with 1 to 20 carbon atoms that can replace an organic group containing Si, O, or N and without active hydrogen, and can have unsaturated bonds. e is an integer from 1 to 3.

[0434] [Chemistry 30]

[0435] In equation (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, R 35 R represents an alkylene group having 1 to 10 carbon atoms. 36 Indicates alkylene groups having 1 to 20 carbon atoms.

[0436] h represents an integer from 1 to 3, i represents an integer of 1 or 2, and (h+i) represents an integer of 4 or higher. R has a complex number of cases. 31 ~R 34 Each is independent.

[0437] [Chemistry 31]

[0438] In equation (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, R 43 ~R 45 Each can be used independently to represent an alkylene group having 1 to 20 carbon atoms.

[0439] m, n, and l each independently represent integers from 1 to 3, and (m+n+l) represents integers greater than 4. R exists in the case of a complex number of cases. 37 ~R 42 Each is independent.

[0440] [Chemistry 32]

[0441] In equation (18), R 46 ~R 48 Each independently represents a single bond or an alkylene group having 1 to 20 carbon atoms, 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, R 54 R represents an alkylene or alkoxy group having 1 to 20 carbon atoms. 55 Alkyl or trialkylsilyl groups having 1 to 20 carbon atoms.

[0442] o represents an integer from 1 to 3, and p represents 1 or 2.

[0443] R in the case of multiple cases 46 ~R 56 o and p are independent of each other and can be the same or different.

[0444] q represents an integer from 0 to 6, r represents an integer from 0 to 6, s represents an integer from 0 to 6, and (q+r+s) is an integer from 4 to 10.

[0445] A represents a hydrocarbon group with 1 to 20 carbon atoms, or an organic group having at least one atom selected from the group consisting of oxygen, nitrogen, silicon, sulfur, and phosphorus atoms but without active hydrogen.

[0446] Examples of coupling modifiers represented by formula (14) above 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-trimethylsilyl-4-(3-(trimethoxysilyl)propyl)piperazine, 1-methylsilyl-4-(3-(trieth ... Piperazine, 1-trimethylsilyl-4-(3-(triethoxysilyl)propyl)piperazine, 1-triethylsilyl-4-(3-(trimethoxysilyl)propyl)piperazine, 1-triethylsilyl-4-(3-(triethoxysilyl)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, etc.

[0447] Among these, from the perspective of improving the reactivity and interaction between conjugated diene polymers and inorganic fillers such as silica, and from the perspective of improving processability, in formula (16), d is preferably 3. Specifically, 1-methyl-4-(3-(trimethoxysilyl)propyl)piperazine and 1-methyl-4-(3-(triethoxysilyl)propyl)piperazine are preferred.

[0448] There are no particular limitations on the reaction temperature and reaction time when the coupling modifier containing nitrogen atoms represented by the above formula (14) reacts with the polymer active end, but it is preferred to react at 0°C or above and 120°C for more than 30 seconds.

[0449] The preferred amount of the coupling modifier represented by formula (14) is the amount of alkoxy groups (OR groups) bonded to the silyl group in the compound represented by formula (14). 8The total molar number of the polymer initiator should be in the range of 0.2 to 2.5 times the molar number of the polymerization initiator, more preferably 0.5 to 2.0 times, and even more preferably 1.0 to 2.0 times. From the viewpoint of making the modification rate and molecular weight of the obtained conjugated diene polymer more preferably within a more desirable range, it is preferably 0.2 times or more. Furthermore, from the viewpoint of suppressing the decrease in processability due to excessive branching, it is preferably 2.5 times or less.

[0450] More specifically, the amount of polymerization initiator and coupling modifier represented by formula (14) can be adjusted such that the molar number of polymerization initiator is preferably 1.5 times or more, more preferably 1.7 times or more, relative to the molar number of coupling modifier represented by formula (14).

[0451] Examples of coupling modifiers represented by formula (15) above include, but are not limited to, N-(1,3-dimethylbutylene)-3-(triethoxysilyl)-1-propane, N-(1,3-dimethylbutylene)-3-(trimethoxysilyl)-1-propane, N-(1,3-dimethylbutylene)-3-methyl(dimethoxysilyl)-1-propane, N-(1,3-dimethylbutylene)-3-methyl(diethoxysilyl)-1-propane, N-(1-methylethylene)-3-(triethoxysilyl)-1-propane, N-(1-methylethylene)-3-(trimethoxysilyl)-1-propane, N-(1-methylethylene)-3-(trimethoxysilyl)-1-propane, N-(1-methyl N-(1-methylethylidene)-3-methyl(dimethoxysilyl)-1-propane, N-ethylidene-3-(triethoxysilyl)-1-propane, N-ethylidene-3-(trimethoxysilyl)-1-propane, N-ethylidene-3-(trimethoxysilyl)-1-propane, N-ethylidene-3-methyl(dimethoxysilyl)-1-propane, N-ethylidene-3-methyl(diethoxysilyl)-1-propane, N-(1-methylpropylidene)-3-(triethoxysilyl)-1-propane, N-(1-methylpropylidene)-3-(trimethoxysilyl)-1-propane, N-(1-methylpropylidene)-3-methyl (Dimethoxysilyl)-1-propane, N-(1-methylpropylidene)-3-methyl(diethoxysilyl)-1-propane, N-benzyl-3-(triethoxysilyl)propane-1-amine, N-benzyl-3-(triethoxysilyl)propane-1-amine, N-benzyl-3-methyl(dimethoxysilyl)propane-1-amine, N-benzyl-3-methyl(diethoxysilyl)propane-1-amine, N-4-methylbenzyl-3-(triethoxysilyl)propane-1-amine, N-4-methylbenzyl-3-(trimethoxysilyl)propane-1-amine, N-4-methylbenzyl-3-(trimethoxysilyl)propane-1-amine, N-4-methylbenzyl-3-methyl(dimethoxysilyl) Propane-1-amine, N-4-methylbenzyl-3-methyl(diethoxysilyl)propane-1-amine, N-naphthyl-3-(triethoxysilyl)propane-1-amine, N-naphthyl-3-(trimethoxysilyl)propane-1-amine, N-naphthyl-3-methyl(diethoxysilyl)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-methyl(diethoxysilyl)propyl)methylamine), 1,1-(1,4-Phenylidene)bis(N-(3-methyl(diethoxysilyl)propyl)methylamine, 2-methoxy-2-methyl-1-(benzylaminoethyl)-1-aza-2-silazane, 2-methoxy-2-methyl-1-(p-methoxybenzylaminoethyl)-1-aza-2-silazane, 2-ethoxy-2-methyl-1-(benzylaminoethyl)-1-aza-2-silazane, 2-methoxy-2-methyl-1-(methylisobutylaminoethyl)-1-aza-2-silazane, etc.

[0452] There are no particular limitations on the reaction temperature and reaction time when the coupling modifier containing nitrogen atoms represented by the above formula (15) reacts with the polymer active end, but it is preferred to react at 0°C or above and 120°C for more than 30 seconds.

[0453] The preferred amount of the coupling modifier represented by formula (15) is the amount of alkoxy group (OR) bonded to the silyl group in the compound represented by formula (15). 14 The total molar number of the polymer initiator should be in the range of 0.2 to 2.5 times the molar number of the polymerization initiator, more preferably 0.5 to 2.0 times, and even more preferably 1.0 to 2.0 times. From the viewpoint of making the modification rate and molecular weight of the obtained conjugated diene polymer more preferably within a more desirable range, it is preferably 0.2 times or more. Furthermore, from the viewpoint of suppressing the decrease in processability due to excessive branching, it is preferably 2.5 times or less.

[0454] More specifically, the amount of polymerization initiator and the amount of coupling modifier represented by the above formula (15) can be adjusted such that the molar number of polymerization initiator is preferably 1.5 times or more, more preferably 1.7 times or more, relative to the molar number of coupling modifier represented by the above formula (15).

[0455] Examples of coupling modifiers having nitrogen-containing groups as represented by formula (16) above include, but are not limited to, 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silazane, 2,2-diethoxy-1-(3-triethoxysilylpropyl)-1-aza-2-silazane, 2,2-dimethoxy-1-(4-trimethoxysilylbutyl)-1-aza-2-silazane, 2,2-dimethoxy-1-(5-trimethoxysilylpentyl)-1-aza-2-silazane, and 2,2-dimethoxy-1-(3-dimethoxymethylsilylpropyl). 1-aza-2-silazopentane, 2,2-diethoxy-1-(3-diethoxyethylsilylpropyl)-1-aza-2-silazopentane, 2-methoxy,2-methyl-1-(3-trimethoxysilylpropyl)-1-aza-2-silazopentane, 2-ethoxy,2-ethyl-1-(3-triethoxysilylpropyl)-1-aza-2-silazopentane, 2-methoxy,2-methyl-1-(3-dimethoxymethylsilylpropyl)-1-aza-2-silazopentane, 2-ethoxy,2-ethyl-1-(3-diethoxyethylsilylpropyl)-1-aza-2-silazopentane, etc.

[0456] Among these, from the perspective of the reactivity and interaction between the functional groups of coupling modifiers containing nitrogen atoms and inorganic fillers such as silicon dioxide, as well as the processability, substances where i represents 2 and h represents 3 are preferred. Specifically, 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silazopentanane and 2,2-diethoxy-1-(3-triethoxysilylpropyl)-1-aza-2-silazopentanane are preferred.

[0457] There are no particular limitations on the reaction temperature and reaction time in the coupling process using the coupling modifier represented by the above formula (16), but it is preferred to react at 0°C or above and 120°C or below for at least 30 seconds.

[0458] The amount of coupling modifier represented by formula (16) above is preferably in the range of 0.2 to 2.5 times the total number of moles of alkoxy groups bonded to the silyl group in the compound represented by formula (16) being more than 0.5 to 2.0 times the number of moles of polymerization initiator added, and even more preferably in the range of 1.0 to 2.0 times. From the viewpoint of making the modification rate, molecular weight and branching structure of the obtained conjugated diene polymer more preferably within a more desirable range, it is preferably 0.2 times or more. In addition, from the viewpoint of suppressing the decrease in processability due to excessive branching, it is preferably 2.5 times or less.

[0459] More specifically, the amount of polymerization initiator and coupling modifier represented by formula (16) can be adjusted such that the molar number of polymerization initiator is preferably 3.0 times or more, more preferably 4.0 times or more, relative to the molar number of coupling modifier represented by formula (16) above.

[0460] Examples of modifiers having nitrogen-containing groups as represented by formula (17) above 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.

[0461] Among these, substances in which n, m, and l all represent 3 are preferred, considering both the reactivity and interaction of the functional groups of the modifier with inorganic fillers such as silicon dioxide, and their processability. Specific examples of preferred materials include tris(3-trimethoxysilylpropyl)amine and tris(3-triethoxysilylpropyl)amine.

[0462] There are no particular limitations on the reaction temperature and reaction time when the modifier containing nitrogen atoms represented by the above formula (17) reacts with the polymer active end, but it is preferred to react at a temperature of 30°C or higher and 120°C or lower for more than 30 seconds.

[0463] Preferably, the total molar number of alkoxy groups bonded to the silyl groups in the coupling modifier represented by formula (17) is in the range of 0.2 to 2.0 times the molar number of lithium constituting the polymerization initiator, more preferably in the range of 0.5 to 2.0 times, and even more preferably in the range of 0.6 to 1.6 times. From the perspective of obtaining sufficient modification rate, molecular weight, and branching structure in the conjugated diene polymer, it is preferably 0.2 times or more. In addition to the preference for obtaining a branched polymer composition by coupling the polymer ends together to improve processability, it is also preferably 2.0 times or less from the perspective of the cost of the coupling modifier.

[0464] More specifically, the molar number of the polymerization initiator relative to the molar number of the modifier is preferably 4.0 times or more, more preferably 5.0 times or more.

[0465] In the above formula (18), A is preferably represented by any of the following general formulas (i) to (iv).

[0466] [Chemistry 33]

[0467] In equation (i), B1 This represents a single bond or a hydrocarbon group with 1 to 20 carbon atoms, where t represents an integer from 1 to 10. The presence of a complex number of B groups... 1 Each is independent.

[0468] [Chemistry 34]

[0469] In equation (ii), B 2 B represents a single bond or a hydrocarbon group with 1 to 20 carbon atoms. 3 The denoting alkyl group has 1 to 20 carbon atoms, and t represents an integer from 1 to 10. The presence of multiple B atoms is also considered. 2 and B 3 Each is independent.

[0470] [Chemistry 35]

[0471] In equation (iii), B 4 This represents a single bond or a hydrocarbon group with 1 to 20 carbon atoms, where t represents an integer from 1 to 10. The presence of a complex number of B groups... 4 Each is independent.

[0472] [Chemistry 36]

[0473] In equation (iv), B 5 This represents a single bond or a hydrocarbon group with 1 to 20 carbon atoms, where t represents an integer from 1 to 10. The presence of a complex number of B groups... 5 Each is independent.

[0474] As a coupling modifier having a nitrogen-containing group when A in formula (18) is represented by formula (i) above, examples include, but are not limited to, tris(3-trimethoxysilylpropyl)amine, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl]amine, bis[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl]-(3-trimethoxysilylpropyl)amine, tri[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl]amine, tri(3-ethoxysilylpropyl)amine, bis(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silazopentanyl)propyl]amine, bis[3 [-(2,2-diethoxy-1-aza-2-silazopentane)propyl]-(3-triethoxysilylpropyl)amine, tris[3-(2,2-diethoxy-1-aza-2-silazopentane)propyl]amine, tetra(3-trimethoxysilylpropyl)-1,3-propanediamine, tris(3-trimethoxysilylpropyl)-[3-(2,2-dimeth ...aza-2-silazopentane)propyl]amine, tris[3-(2,2-diethoxy-1-aza-2-silazopentane)propyl]amine, tetra(3-trimethoxysilylpropyl)-1,3-propanediamine, tris(3-trimethoxy [3-(2,2-dimethoxy-1-aza-2-silazacyclopentane)propyl]-1,3-propanediamine, bis(3-trimethoxysilylpropyl)-bis[3-(2,2-dimethoxy-1-aza-2-silazacyclopentane)propyl]-1,3-propanediamine, tris[3-(2,2-dimethoxy-1-aza-2-silazacyclopentane)propyl]-(3-trimethoxysilylpropyl)-1,3-propanediamine, etc.

[0475] Examples of other examples include tetra[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl]-1,3-propanediamine, tris(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-silazopentanyl)propyl]-1,3-propanediamine, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl]-[3-(1-methoxy-2-trimethylsilyl-1-silazopentanyl)propyl]-1,3-propanediamine, and bis[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl]-(3-trimethoxysilylpropyl)-[3-( 1-Methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, tris[3-(2,2-dimethoxy-1-aza-2-silane)propyl]-[3-(1-methoxy-2-trimethylsilyl-1-sila-2-azacyclopentane)propyl]-1,3-propanediamine, tetra(3-triethoxysilylpropyl)-1,3-propanediamine, tris(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silane)propyl]-1,3-propanediamine, bis(3-triethoxysilylpropyl)-bis[3-(2,2-diethoxy-1-aza-2-silane)propyl]-1,3- Propylenediamine, tris[3-(2,2-diethoxy-1-aza-2-silazopentanyl)propyl]-(3-triethoxysilylpropyl)-1,3-propanediamine, tetra[3-(2,2-diethoxy-1-aza-2-silazopentanyl)propyl]-1,3-propanediamine, tris(3-triethoxysilylpropyl)-[3-(1-ethoxy-2-trimethylsilyl-1-silaz-2-azacyclopentane)propyl]-1,3-propanediamine, bis(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-silazopentanyl)propyl]-[3-(1-ethoxy-2-trimethylsilyl-1-silaz-2-azacyclopentane)propyl]-1,3-propanediamine Diamine, bis[3-(2,2-diethoxy-1-aza-2-silazopentanyl)propyl]-(3-triethoxysilylpropyl)-[3-(1-ethoxy-2-trimethylsilyl-1-silaz-2-azacyclopentane)propyl]-1,3-propanediamine, tris[3-(2,2-diethoxy-1-aza-2-silazopentanyl)propyl]-[3-(1-ethoxy-2-trimethylsilyl-1-silaz-2-azacyclopentane)propyl]-1,3-propanediamine, tetra(3-trimethoxysilylpropyl)-1,3-diaminomethylcyclohexane, tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl]-1,3-propanediamine, tetra(3-trimethoxysilylpropyl)-1,3-diaminomethylcyclohexane, tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl]-1,3-propanediamine,3-Diaminomethylcyclohexane, bis(3-trimethoxysilylpropyl)-bis[3-(2,2-dimethoxy-1-aza-2-silazopentan)propyl]-1,3-diaminomethylcyclohexane, tris[3-(2,2-dimethoxy-1-aza-2-silazopentan)propyl]-(3-trimethoxysilylpropyl)-1,3-diaminomethylcyclohexane, tetra[3-(2,2-dimethoxy-1-aza-2-silazopentan)propyl]-1,3-propanediamine, tris(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-silaz-2-azaazopentan)propyl]-1,3-diaminomethylcyclohexane, etc.

[0476] Further examples include bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl]-[3-(1-methoxy-2-trimethylsilyl-1-silazopentanyl)propyl]-1,3-diaminomethylcyclohexane, bis[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl]-(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethylsilyl-1-silazopentanyl)propyl]-1,3-diaminomethylcyclohexane, and tri[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl]-1,3-diaminomethylcyclohexane. [3-(1-methoxy-2-trimethylsilyl-1-silaz-2-azicyclopentane)propyl]-1,3-diaminomethylcyclohexane, tetra(3-triethoxysilylpropyl)-1,3-propanediamine, tri(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aziaz-2-silazpentane)propyl]-1,3-diaminomethylcyclohexane, bis(3-triethoxysilylpropyl)-bis[3-(2,2-diethoxy-1-aziaz-2-silazpentane)propyl]-1,3-diaminomethylcyclohexane, tri ... [3-Triethoxysilylpropyl]-1,3-propanediamine, tetra[3-(2,2-diethoxy-1-aza-2-azacyclopentane)propyl]-1,3-propanediamine, tri(3-triethoxysilylpropyl)-[3-(1-ethoxy-2-trimethylsilyl-1-aza-2-azacyclopentane)propyl]-1,3-diaminomethylcyclohexane, bis(3-triethoxysilylpropyl)-[3-(2,2-diethoxy-1-aza-2-azacyclopentane)propyl]-[3-(1-ethoxy-2-trimethylsilyl-1-aza-2-azacyclopentane)propyl]-1,3-diaminomethylcyclohexane Examples of such products include bis[3-(2,2-diethoxy-1-aza-2-silazopentanyl)propyl]-(3-triethoxysilylpropyl)-[3-(1-ethoxy-2-trimethylsilyl-1-silaz-2-azacyclopentane)propyl]-1,3-diaminomethylcyclohexane, tris[3-(2,2-diethoxy-1-aza-2-silazopentanyl)propyl]-[3-(1-ethoxy-2-trimethylsilyl-1-silaz-2-azacyclopentane)propyl]-1,3-diaminomethylcyclohexane, tetra(3-trimethoxysilylpropyl)-1,6-hexanediamine, and penta(3-trimethoxysilylpropyl)-diethylenetriamine.

[0477] As a coupling modifier having a nitrogen-containing group when A in formula (18) is represented by formula (ii) above, examples include, but are not limited to, tris(3-trimethoxysilylpropyl)-methyl-1,3-propanediamine, bis(2-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl]-methyl-1,3-propanediamine, bis[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl]-(3-trimethoxysilylpropyl)-methyl-1,3-propanediamine, tris(3-triethoxysilylpropyl)-methyl-1,3-propanediamine, bis(2-triethoxysilylpropyl)-[3-(2,2-dimeth ... [3-(2,2-diethoxy-1-aza-2-silazopentanyl)propyl]-methyl-1,3-propanediamine, bis[3-(2,2-diethoxy-1-aza-2-silazopentanyl)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), 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, etc.

[0478] As a coupling modifier having a nitrogen-containing group when A in formula (18) is represented by formula (iii) above, examples include, but are not limited to, tetrakis[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl]silane, tris[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl]-(3-trimethoxysilylpropyl)silane, tris[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl]-(3-trimethoxysilylpropyl)silane, and tris[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl]-(3-trimethoxysilylpropyl)silane. [3-(1-methoxy-2-trimethylsilyl-1-silaz-2-azacyclopentane)propyl]silane, bis(3-trimethoxysilylpropyl)-bis[3-(2,2-dimethoxy-1-aza-2-azacyclopentane)propyl]silane, (3-trimethoxysilyl)-[3-(1-methoxy-2-trimethylsilyl-1-silaz-2-azacyclopentane)-bis[3-(2,2-dimethoxy-1-aza-2 ... [2-Syrazolane)propyl]silane, bis[3-(1-methoxy-2-trimethylsilyl-1-sily-2-azacyclopentane)-bis[3-(2,2-dimethoxy-1-aza-2-syrazolane)propyl]silane, tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-syrazolane)propyl]silane, bis(3-trimethoxysilylpropyl)-[3-(1-methoxy-2-trimethyl] [3-(2,2-dimethoxy-1-aza-2-azacyclopentane)propyl]-[3-(2,2-dimethoxy-1-aza-2-azacyclopentane)propyl]silane, bis[3-(1-methoxy-2-trimethylmethoxy-1-aza-2-azacyclopentane)propyl]-bis(3-trimethoxymethoxypropyl)silane, bis(3-trimethoxymethoxypropyl)-bis[3-(1-methoxy-2-methyl-1-aza-2-azacyclopentane)propyl]silane, etc.

[0479] As a modifier having a nitrogen-containing group as A in formula (18) represented by formula (iv) above, examples include, but are not limited to, 3-tris[2-(2,2-dimethoxy-1-aza-2-silazopentane)ethoxy]silyl-1-(2,2-dimethoxy-1-aza-2-silazopentane)propane, 3-tris[2-(2,2-dimethoxy-1-aza-2-silazopentane)ethoxy]silyl-1-trimethoxysilylpropane, etc.

[0480] In the above formula (18), A is preferably represented by formula (i) or formula (ii), and s represents 0.

[0481] Coupling modifiers containing nitrogen-containing groups are readily available and tend to exhibit superior wear resistance and low hysteresis loss performance when conjugated diene polymers are converted into sulfides. Examples of such coupling modifiers containing nitrogen-containing groups include, but are not limited to, bis(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl]amine, tris(3-trimethoxysilylpropyl)amine, tris(3-triethoxysilylpropyl)amine, tris(3-trimethoxysilylpropyl)-[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl]-1,3-propanediamine, tetra[3- [2,2-Dimethoxy-1-aza-2-silazopentanyl)propyl]-1,3-propanediamine, tetra(3-trimethoxysilylpropyl)-1,3-propanediamine, tetra(3-trimethoxysilylpropyl)-1,3-diaminomethylcyclohexane, tris(3-trimethoxysilylpropyl)-methyl-1,3-propanediamine, bis[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl]-(3-trimethoxysilylpropyl)-methyl-1,3-propanediamine, etc.

[0482] 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 from 2 to 10.

[0483] This results in a tendency for the vulcanized material to exhibit superior wear resistance and low hysteresis loss performance.

[0484] Examples of coupling modifiers having nitrogen-containing groups include, but are not limited to, tetrakis[3-(2,2-dimethoxy-1-aza-2-silazopentanyl)propyl]-1,3-propanediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-diaminomethylcyclohexane, 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-propanediamine, etc.

[0485] The amount of compound represented by the above formula (18), which is a coupling modifier having a group containing nitrogen atoms, can be adjusted in such a way that the reaction is carried out in a desired stoichiometric ratio of the number of moles of the conjugated diene polymer to the number of moles of the coupling modifier, thereby tending to achieve the desired star-shaped highly branched structure.

[0486] The specific molar number of the polymerization initiator is preferably 5.0 times or more, and more preferably 6.0 times or more, relative to the molar number of the coupling modifier.

[0487] 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, more preferably an integer of 6 to 10.

[0488] The method for manufacturing conjugated diene polymers according to this embodiment may include a condensation reaction step, which generates a condensation reaction by adding a condensation accelerator, after the step of adding a coupling modifier and / or before the step of adding a coupling modifier.

[0489] The method for manufacturing conjugated diene polymers according to this embodiment may include a modification step using a modifier other than the coupling modifier described above.

[0490] In the method for manufacturing conjugated diene polymers according to this embodiment, two or more coupling modifiers may be added in the step of adding coupling modifiers.

[0491] When adding two coupling modifiers, it is preferable to use coupling modifiers with different numbers of functional groups in combination.

[0492] Furthermore, when adding three or more coupling modifiers, it is preferable to include a combination of coupling modifiers with different numbers of functional groups.

[0493] In the process of adding coupling modifiers, it is preferable to add two coupling modifiers with different numbers of functional groups.

[0494] Combinations of two coupling modifiers with different numbers of functional groups can be used, for example, combinations of coupling modifiers with fewer than two functional groups and coupling modifiers with more than three functional groups. It is preferable to add two or more coupling modifiers simultaneously, but they can also be mixed beforehand or not.

[0495] The method for manufacturing conjugated diene polymers according to this embodiment may include a hydrogenation step for hydrogenating the conjugated diene portion. There is no particular limitation on the method for hydrogenating the conjugated diene portion; known methods may be used.

[0496] As a preferred hydrogenation process, one method is to hydrogenate the conjugated diene by blowing gaseous hydrogen into a polymer solution in the presence of a catalyst.

[0497] There are no particular limitations on the catalysts used. Examples include heterogeneous catalysts such as catalysts in which noble metals are supported on porous inorganic materials; catalysts in which salts of nickel, cobalt, etc. are soluble and react with organoaluminum compounds; and homogeneous catalysts such as catalysts using metallocenes such as cyclopentadiene titanium.

[0498] Among these, cyclopentadiene titanium catalysts are preferred from the perspective of being able to select milder hydrogenation conditions. Additionally, methods using supported catalysts of noble metals can be cited as methods for hydrogenating aromatic groups.

[0499] In addition, as a hydrogenation process that does not use gaseous hydrogen, a method of contacting the hydrogenation catalyst with a polymer solution can be cited. There are no particular limitations on such hydrogenation catalysts, and examples include: (1) supported heterogeneous hydrogenation catalysts made by supporting metals such as Ni, Pt, Pd or Ru on carbon, silicon oxide, aluminum oxide or diatomaceous earth; (2) so-called Ziegler-type hydrogenation catalysts using transition metal salts such as organic acid salts or acetylacetonates of Ni, Co, Fe or Cr and reducing agents such as organoaluminum; (3) so-called organometallic complexes such as organometallic compounds of Ti, Ru, Rh or Zr; and so on. Furthermore, there are no particular limitations on other hydrogenation catalysts, and examples include those known in Japanese Patent Publication Nos. 42-8704, 43-6636, 63-4841, 1-37970, 1-53851, 2-9041, and 8-109219. As a preferred hydrogenation catalyst, a reaction mixture of a cyclopentadiene titanium compound and a reducing organometallic compound can be cited.

[0500] In the method for manufacturing conjugated diene polymers according to this embodiment, after the coupling step based on the coupling modifier, deactivating agents and / or neutralizing agents may be added to the polymer solution as needed.

[0501] Examples of deactivating agents include, but are not limited to, water, and alcohols such as methanol, ethanol, and isopropanol.

[0502] Examples of neutralizing agents include, but are not limited to, aqueous solutions of carboxylic acids, inorganic acids, such as stearic acid, oleic acid, and neodecanoic acid (a mixture of multi-branched carboxylic acids with 9 to 11 carbon atoms and 10 carbon atoms as the main component), as well as carbon dioxide.

[0503] The method for manufacturing the conjugated diene polymer of this embodiment may include a step of obtaining the obtained conjugated diene polymer from a polymer solution. As such a method, a known method may be used, for example, the following method.

[0504] That is, the following methods can be cited: separating the solvent by stripping or the like, filtering out the polymer, and then further dehydrating and drying it to obtain the polymer; concentrating it in a flash tank and then further devolatilizing it using an exhaust extruder or the like to obtain the polymer; and directly devolatilizing it using a rotary dryer or the like to obtain the polymer; and so on.

[0505] [Rubber Composition]

[0506] The rubber composition of this embodiment contains a rubber component comprising the conjugated diene polymer of this embodiment described above.

[0507] When the conjugated diene polymer of this embodiment is compounded in a tire, the oil contained in the briquette molded body is inevitably contained in the tire as well. With the oil filling amount reduced in advance, the oil contained in the tire is also reduced, thus having the advantage of correspondingly increasing the compositional freedom in tire design.

[0508] The conjugated diene polymer of this embodiment and its sheet or block molded articles (also called briquettes) may contain a softener component described later. In the above-mentioned molded articles (briquettes), from the perspective of increasing the degree of freedom in the mixing design when producing rubber compositions, the amount of 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, further more preferably less than 1 part by mass, and most preferably no softener is added, relative to 100 parts by mass of the conjugated diene polymer.

[0509] There are no particular limitations on rubber softeners; examples include filler oils, liquid rubbers, and resins.

[0510] From the perspective of increasing the degree of freedom in the compounding design when producing rubber compositions using the above-mentioned molded articles, conjugated diene polymers and their sheet or block molded articles are preferably provided in a state without the addition of rubber softeners.

[0511] Typically, there is an upper limit to the total amount of rubber softener relative to the overall rubber composition. However, when rubber softeners are added to sheet or block molded bodies of conjugated diene polymers, the rubber composition manufactured by blending these molded bodies will also contain the aforementioned rubber material softener. Therefore, the total amount of rubber softener relative to the overall rubber composition is limited, restricting the freedom to choose the types and amounts of rubber softeners that need to be blended during the production of the rubber composition. From the perspective of increasing the freedom to choose the types and blending amounts of rubber softeners according to the required performance of the rubber composition, it is preferable to reduce the amount of softener added to sheet or block molded bodies of conjugated diene polymers.

[0512] Although not particularly limited, for example, by reducing the amount of filler oil added to the conjugated diene polymers and their sheet or block molded articles in this embodiment, it is possible to blend more resins such as filler oil during the production of rubber compositions using them. This is preferred from the perspective of further improving the breaking strength of the rubber compositions and their vulcanides.

[0513] In rubber compositions using the conjugated diene polymers of this embodiment and in sheet or block form, rubber stabilizers may be further included to suppress gel formation and improve stability during processing.

[0514] As a stabilizer for rubber, substances that can be used, but are not limited to those known, include antioxidants such as 2,6-di-tert-butyl-4-hydroxytoluene (hereinafter also referred to as "BHT"), octadecyl 3-(4'-hydroxy-3',5'-di-tert-butylphenol)propionate, and 2-methyl-4,6-bis[(octylthio)methyl]phenol.

[0515] The briquette of this embodiment contains 100 parts by weight of the modified conjugated diene polymer of this embodiment and less than 2 parts by weight of a plasticizer component. Alternatively, the briquette of this embodiment may contain 100 parts by weight of the modified conjugated diene polymer of this embodiment and less than 1 part by weight of a plasticizer component.

[0516] The rubber composition of this embodiment includes 100 parts by weight of rubber component and 5.0 to 150 parts by weight of filler material. Among the rubber component, relative to the total amount of 100 parts by weight of the rubber component, it includes 10 parts by weight or more of the modified conjugated diene polymer of this embodiment or the briquettes of this embodiment.

[0517] The rubber composition of this embodiment comprises 100 parts by weight of rubber component and 5.0 to 150 parts by weight of filler material.

[0518] Of the rubber components described above, 10 or more parts by mass of the conjugated diene polymer of this embodiment are preferably included relative to the total amount of rubber components (100 parts by mass).

[0519] By dispersing the filler material in a rubber component containing the conjugated diene polymer of this embodiment, the processability during vulcanization is improved, resulting in a rubber composition with superior low hysteresis loss, destructive properties, and abrasion resistance of its vulcanizate. Furthermore, by including the conjugated diene polymer of this embodiment in a predetermined proportion within the rubber component, fuel efficiency, processability, and abrasion resistance are further enhanced.

[0520] Examples of filler materials include, but are not limited to, silica-based inorganic fillers, carbon black, metal oxides, and metal hydroxides. Among these, silica-based inorganic fillers are preferred. In particular, when the rubber composition of this embodiment is used in automotive parts such as tires and anti-vibration rubber, and in vulcanized rubber applications such as shoes, it is especially preferable to include silica-based inorganic fillers. Such fillers can be used alone or in combination of two or more.

[0521] There are no particular limitations on the silica-based inorganic filler material; any known substance can be used. Solid particles containing SiO2 or Si3Al as structural units are preferred, and solid particles containing SiO2 or Si3Al as the main structural unit are more preferred. Here, "main component" refers to a component that contains more than 50% by mass, preferably 70% by mass or more, and more preferably 80% by mass or more in the silica-based inorganic filler material.

[0522] Specific examples of silica-based inorganic fillers include, but are not limited to, inorganic fibrous materials such as silica, clay, talc, mica, diatomaceous earth, wollastonite, montmorillonite, zeolite, and glass fiber. Silica-based inorganic fillers with hydrophobicated surfaces, as well as mixtures of silica-based inorganic fillers and inorganic fillers other than silica-based fillers, can also be used. Among these, silica or glass fiber is preferred, and silica is more preferred, from the perspective of further improving the strength and abrasion resistance of the rubber composition. The silica is not particularly limited; examples include dry silica, wet silica, and synthetic silicate silica. Among these silicas, wet silica is preferred from the perspective of further improving the breaking strength of the rubber composition.

[0523] From the perspective of obtaining a rubber composition with practically good wear resistance and breaking strength, the nitrogen adsorption specific surface area of ​​the silica-based inorganic filler material, determined by the BET adsorption method, is preferably 100 m². 2 / g or more 300m 2 / g or less, more preferably 170m 2 / g or more 250m 2 / g or less. Additionally, products with smaller specific surface areas (e.g., specific surface area less than 200m²) can be supplied as needed. 2 / g) of silica-based inorganic filler materials with a large specific surface area (e.g., 200m²) 2 A combination of silica-based inorganic fillers (at least 1 g) is used. In this embodiment, a particularly large specific surface area (e.g., 200 m²) is employed. 2In the case of silica-based inorganic fillers (at least / g), conjugated diene polymers further improve the dispersibility of silica. As a result, the obtained rubber compositions tend to have superior abrasion resistance, breaking strength, and low hysteresis loss.

[0524] Examples of carbon black include, but are not limited to, various grades such as SRF, FEF, HAF, ISAF, and SAF. Among these, carbon black with a nitrogen adsorption specific surface area of ​​50 m² determined by the BET adsorption method is preferred. 2 Carbon black with an oil absorption of 80 mL / 100 g or more and a dibutyl phthalate (DBP) oil absorption of 80 mL / 100 g or less.

[0525] As a metal oxide, as long as it has the chemical formula M x O y (M represents a metal atom, and x and y each independently represent integers from 1 to 6) There are no particular limitations on the solid particles that are the main components of the structural unit, such as aluminum oxide, titanium oxide, magnesium oxide and zinc oxide.

[0526] Examples of metal hydroxides include, but are not limited to, aluminum hydroxide, magnesium hydroxide, and zirconium hydroxide.

[0527] Regarding the content of filler material in the rubber composition of this embodiment, it is 5.0 parts by mass or more and 150 parts by mass or less relative to 100 parts by mass of rubber component, preferably 20 parts by mass or more and 100 parts by mass or less, and more preferably 30 parts by mass or more and 90 parts by mass or less. By keeping the filler material within the above range, the rubber composition tends to have better processability during vulcanization, lower hysteresis loss of its vulcanizate, better destructive properties, and better abrasion resistance.

[0528] In the rubber composition of this embodiment, from the viewpoint of reliably imparting the properties required for applications such as dry grip and conductivity in tires, it is preferable to contain 0.5 to 100 parts by weight of carbon black relative to 100 parts by weight of the rubber component containing the conjugated diene polymer. Similarly, from the same viewpoint, it is more preferable for the rubber composition to contain 3.0 to 100 parts by weight of carbon black relative to 100 parts by weight of the rubber component containing the conjugated diene polymer, and even more preferable to contain 5.0 to 50 parts by weight of carbon black.

[0529] The rubber composition of this embodiment may further include a silane coupling agent. By including a silane coupling agent, the rubber composition can further enhance the interaction between the rubber component and the filler material.

[0530] As a silane coupling agent, compounds having, for example, a sulfur-bonded moiety and an alkoxysilyl or silanol moiety in one molecule are preferred, but not limited to. Examples of such compounds include, but are not limited to, bis-[3-(triethoxysilyl)-propyl]-tetrasulfide, bis-[3-(triethoxysilyl)-propyl]-disulfide, bis-[2-(triethoxysilyl)-ethyl]-tetrasulfide, etc.

[0531] In the rubber composition of this embodiment, the content of the silane coupling agent relative to 100 parts by mass of the filler material is preferably 0.1 parts by mass to 30 parts by mass, more preferably 0.5 parts by mass to 20 parts by mass, and even more preferably 1.0 parts by mass to 15 parts by mass. If the content of the silane coupling agent is within the above range, it tends to further improve the interaction between the rubber component and the filler material.

[0532] In the rubber composition of this embodiment, the rubber component may include a rubber-like polymer other than the conjugated diene polymer of this embodiment (hereinafter referred to as "rubber-like polymer"). The conjugated diene polymer of this embodiment and the above-mentioned rubber-like polymer are collectively referred to as "rubber component".

[0533] Examples of rubber-like polymers include, but are not limited to, conjugated diene polymers and their hydrides, random copolymers of conjugated diene compounds and vinyl aromatic compounds and their hydrides, block copolymers of conjugated diene compounds and vinyl aromatic compounds and their hydrides, non-diene polymers, and natural rubber.

[0534] Examples of rubber-like polymers include, but are not limited to, butadiene rubber and its hydrogenated derivatives, isoprene rubber and its hydrogenated derivatives, styrene-butadiene rubber and its hydrogenated derivatives, styrene-butadiene block copolymers and their hydrogenated derivatives, styrene-isoprene block copolymers and their hydrogenated derivatives, nitrile rubber and its hydrogenated derivatives, etc.

[0535] 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.

[0536] Examples of natural rubber include, but are not limited to, RSS3-5, SMR, and epoxidized natural rubber, which are smoked sheet rubbers.

[0537] The rubber-like polymer can be a modified rubber endowed with polar functional groups such as hydroxyl and amino groups. When the rubber composition of this embodiment is used for tire applications, the rubber-like polymer is preferably one or more selected from the group consisting of butadiene rubber, isoprene rubber, styrene-butadiene rubber, natural rubber, and butyl rubber.

[0538] From the perspective of balancing the abrasion resistance, breaking strength, low hysteresis loss, and processability of the rubber composition, the weight-average molecular weight of the rubber-like polymer is preferably 2,000 to 2,000,000, more preferably 5,000 to 1,500,000. Furthermore, low molecular weight rubber-like polymers, also known as liquid rubbers, can also be used as rubber-like polymers. These rubber-like polymers can be used alone or in combination of two or more.

[0539] In the case where the rubber composition of this embodiment contains a conjugated diene polymer and a rubber-like polymer, the content ratio (mass ratio) of the conjugated diene polymer to the rubber-like polymer, i.e., (conjugated diene polymer / rubber-like polymer), is preferably 10 / 90 or more and 100 / less, more preferably 20 / 80 or more and 90 / 10 or less, and even more preferably 30 / 70 or more and 80 / 20 or less.

[0540] That is, in the rubber component, relative to the total amount of the aforementioned rubber component (100 parts by mass), the conjugated diene polymer of this embodiment preferably contains 10 to 100 parts by mass, more preferably 20 to 90 parts by mass, and even more preferably 30 to 80 parts by mass. If the proportion of the conjugated diene polymer contained in the rubber component is within the above range, the rubber composition tends to have better abrasion resistance and lower hysteresis loss properties.

[0541] In this embodiment of the rubber composition, from the perspective of further improving its processability, in addition to the rubber component, a softener component (e.g., a rubber softener) is also included.

[0542] There are no particular limitations on the components that can be used as plasticizers; examples include liquid rubber, resin, and filler oil.

[0543] There are no particular limitations on liquid rubber; examples include liquid polybutadiene and liquid styrene-butadiene rubber.

[0544] When liquid rubber is used as a softener component, in addition to the effects mentioned above, the glass transition temperature of the conjugated diene polymer composition can be further reduced, thus tending to further improve the wear resistance, low hysteresis loss and low temperature characteristics of its sulfides.

[0545] Examples of resins include, but are not limited to, aromatic petroleum resins, benzofuran-indene resins, terpene resins, rosin derivatives (including tung oil resins), tall oil, tall oil derivatives, rosin ester resins, natural and synthetic terpene resins, aliphatic hydrocarbon resins, aromatic hydrocarbon resins, mixed aliphatic-aromatic hydrocarbon resins, coumarin-indene resins, phenol resins, p-tert-butylphenol-acetylene resins, phenol-formaldehyde resins, xylene-formaldehyde resins, oligomers of monoolefins, oligomers of dienes, hydrogenated aromatic hydrocarbon resins, cyclic aliphatic hydrocarbon resins, hydrogenated hydrocarbon resins, hydrocarbon resins, hydrogenated tung oil resins, hydrogenated oil resins, and esters of hydrogenated oil resins with monofunctional or polyfunctional alcohols. These resins can be used alone or in combination of two or more. Furthermore, when hydrogenating these resins, all unsaturated groups may be hydrogenated, or some may remain.

[0546] When resin is used as a softening agent component, in addition to the effects mentioned above, there is a further tendency to increase the breaking strength of the sulfide of the conjugated diene polymer composition.

[0547] In the rubber composition of this embodiment, in order to further improve the breaking strength of its vulcanizate, in addition to the rubber component, it is suitable to add a resin as a softener component.

[0548] In the rubber composition of this embodiment, from the perspective of further improving its processability, in addition to the rubber component, a softener component may be added, and mineral oil or liquid or low molecular weight synthetic softener is suitable.

[0549] Examples of filler oils include aromatic oils, cycloalkanes, and alkanes. Among these, alternative aromatic oils with a polycyclic aromatic (PCA) content of 3% by mass or less based on the IP346 method are preferred from the perspectives of environmental safety, preventing oil seepage, and improving wetland grip. There are no particular limitations on alternative aromatic oils, and examples include TDAE (Treated Distillate Aromatic Extracts), MES (Mild Extraction Solvate), and RAE (Residual Aromatic Extracts) shown in Kautschuk Gummi Kunststoffe 52(12)799(1999).

[0550] Mineral oil-based rubber softeners, also known as processing oils or expander oils, used to soften, compatibilize, and improve the processability of rubber, are mixtures of aromatic rings, cycloalkane rings, and alkane chains. Specifically, substances in which the number of carbon atoms belonging to alkane chains is 50% or more of the total carbon atoms are called alkane-based substances; substances in which the number of carbon atoms belonging to cycloalkane rings is 30% to 45% of the total carbon atoms are called cycloalkane-based substances; and substances in which the number of carbon atoms belonging to aromatic rings is greater than 30% of the total carbon atoms are called aromatic-based substances. In the rubber composition of this embodiment, a rubber softener having a suitable aromatic content is preferably included. By including such a rubber softener, the affinity with conjugated diene polymers is further improved.

[0551] The content of the softener component in the rubber composition of this embodiment is expressed as the amount of softener component pre-added to the conjugated diene polymer and the rubber-like polymer of this embodiment, and the total amount of softener component added when making the rubber composition.

[0552] In the rubber composition of this embodiment, the content of the softener component relative to 100 parts by mass of the rubber component is preferably 0 parts by mass or more than 100 parts by mass, more preferably 10 parts by mass or more than 90 parts by mass, and even more preferably 30 parts by mass or more than 90 parts by mass. By making the content of the rubber softener 100 parts by mass or less relative to 100 parts by mass of the rubber component, exudation can be suppressed, and the stickiness of the surface of the rubber composition can be further suppressed.

[0553] Regarding the method for manufacturing the rubber composition of this embodiment, there are no particular limitations on the method of mixing the conjugated diene polymer of this embodiment, rubber-like polymers other than the conjugated diene polymer of this embodiment, fillers, silane coupling agents if necessary, and rubber softeners. Examples include melt mixing using conventional mixers such as open mills, Banbury mixers, kneaders, single-screw extruders, twin-screw extruders, and multi-screw extruders; and methods such as dissolving and mixing the components and then heating to remove the solvent. Among these, melt mixing using rollers, Banbury mixers, kneaders, or extruders is preferred from the perspective of productivity and good mixability. Furthermore, the rubber components can be mixed with fillers, silane coupling agents, and additives in one step, or they can be mixed in multiple steps.

[0554] The rubber composition of this embodiment can be a sulfide obtained by vulcanization treatment using a vulcanizing agent. Examples of vulcanizing agents include, but are not limited to, free radical initiators such as organic peroxides and azo compounds, oxime compounds, nitroso compounds, polyamine compounds, sulfur, and sulfur-containing compounds. Sulfur-containing compounds include sulfur monochloride, sulfur dichloride, disulfide compounds, and high-molecular-weight polysulfide compounds.

[0555] In the rubber composition of this embodiment, the content of vulcanizing agent is preferably 0.01 parts by mass or more and 20 parts by mass or less, more preferably 0.1 parts by mass or more and 15 parts by mass or less, relative to 100 parts by mass of rubber component. As the vulcanization method, conventionally known methods can be used. Furthermore, as the vulcanization temperature, it is preferably 120°C or more and 200°C or less, more preferably 140°C or more and 180°C or less.

[0556] When vulcanizing the rubber composition, vulcanization accelerators and / or vulcanization aids may be used as needed. As vulcanization accelerators, existing known materials may be used, including, but not limited to, sulfenamide-based, guanidine-based, thiuram-based, aldehyde-amine-based, aldehyde-amine-based, thiazole-based, thiourea-based, and dithiocarbamate-based vulcanization accelerators.

[0557] In addition, examples of vulcanizing aids include, but are not limited to, zinc oxide and stearic acid.

[0558] Relative to 100 parts by weight of rubber component, the content of vulcanization accelerator and vulcanization aid is preferably 0.01 parts by weight or more and 20 parts by weight or less, more preferably 0.1 parts by weight or more and 15 parts by weight or less.

[0559] In the rubber composition of this embodiment, various additives such as softeners and fillers other than those described above, heat stabilizers, antistatic agents, weather stabilizers, anti-aging agents, colorants, and slip agents can be used within a range that does not impair the effects of this embodiment. Known softeners can be used as softeners. There are no particular limitations on fillers; specifically, examples include calcium carbonate, magnesium carbonate, aluminum sulfate, and barium sulfate. Known materials can be used as heat stabilizers, antistatic agents, weather stabilizers, anti-aging agents, colorants, and lubricants.

[0560] [tire]

[0561] The tire of this embodiment contains the rubber composition described above.

[0562] As the tire of this embodiment, various types of tires can be cited, but are not limited to, such as fuel-efficient tires, all-season tires, high-performance tires, and studless tires. The rubber composition of this embodiment can be appropriately used in various parts of the tire, such as the tread, tire body, tire sidewall, and tire bead.

[0563] It should be noted that, unless otherwise specified, the numerical ranges recorded above as preferred ranges can be replaced with any combination of the values ​​recorded as upper limits and the values ​​recorded as lower limits.

[0564] Example

[0565] The following specific embodiments and comparative examples further illustrate this implementation in detail, but the present invention is not limited to the following embodiments and comparative examples.

[0566] The various physical properties in the examples and comparative examples were determined by the methods shown below.

[0567] (Physical Property 1) Average molecular weight determined by GPC method

[0568] Unmodified conjugated diene polymers and modified conjugated diene polymers were used as samples. GPC measurements were performed using a GPC measuring apparatus (Tosoh Corporation, trade name "HLC-8320GPC") with three columns connected to a polystyrene-based gel as the filling material, and a refractive index (RI) detector (Tosoh Corporation, trade name "HLC8020"). Based on the calibration curves obtained using standard polystyrene, the weight-average molecular weight (Mw), number-average molecular weight (Mn), and molecular weight distribution (Mw / Mn) were determined.

[0569] The eluent used was a 5 mmol / L triethylamine-THF (tetrahydrofuran) solution. For the column, three Tosoh "TSKgel SuperMultiporeHZ-H" columns were connected together, with a Tosoh "TSKguardcolumn SuperMP(HZ)-H" column connected in front of them as a guard column.

[0570] The test sample (10 mg) was dissolved in 10 mL of THF to prepare the test solution. 10 μL of the test solution was injected into the GPC test apparatus and the test was performed at an oven temperature of 40 °C and a THF flow rate of 0.35 mL / min.

[0571] The measured results are used as the average molecular weights of the sample.

[0572] (Physical Property 2) Polymer Mooney Viscosity

[0573] Unmodified conjugated diene polymers and modified conjugated diene polymers were used as samples, and the Mooney viscosity was determined using a Mooney viscometer (trade name "VR1132" manufactured by Uejima Corporation) according to ISO 289 using an L-shaped rotor.

[0574] Regarding the measurement temperature, when using unmodified conjugated diene polymers as samples, the temperature is set to 110℃. When using modified conjugated diene polymers as samples, the temperature is set to 100℃.

[0575] After preheating the sample at the test temperature for 1 minute, the rotor was rotated at 2 rpm, and the torque was measured after 4 minutes. The Mooney viscosity (ML) was then determined accordingly. (1+4) ).

[0576] (Property 3) Mooney stress relaxation rate

[0577] Unmodified conjugated diene polymers and modified conjugated diene polymers were used as samples. The Mooney viscosity was measured using a Mooney viscometer (trade name "VR1132" manufactured by Uejima Corporation) according to ISO 289, using an L-shaped rotor. The rotor was stopped immediately afterward, and the torque was recorded every 0.1 seconds for 1.6 to 5 seconds after stopping, in Mooney units. A double logarithmic plot of torque and time (seconds) was performed, and the slope of the straight line was calculated. Its absolute value was taken as the Mooney stress relaxation rate (MSR).

[0578] Regarding the measurement temperature, when using unmodified conjugated diene polymers as samples, the temperature is set to 110℃. When using modified conjugated diene polymers as samples, the temperature is set to 100℃.

[0579] (Physical Properties 4, 8) Branching Degree (Bn) and Absolute Molecular Weight

[0580] The modified conjugated diene polymer was used as the sample, and a GPC measuring device (trade name "GPCmax VE-2001" manufactured by Malvern) was used, which was connected to three columns with polystyrene gel as the filling material. The measurements were performed using three detectors connected in the order of light scattering detector, RI detector, and viscosity detector (trade name "TDA305" manufactured by Malvern). Based on standard polystyrene, the absolute molecular weight was determined from the results of the light scattering detector and RI detector, and the intrinsic viscosity was determined from the results of the RI detector and viscosity detector.

[0581] Assume that the linear polymer follows an intrinsic viscosity [η0] = 10. -3.498 M 0.711 The shrinkage factor (g') is calculated as the ratio of intrinsic viscosity to the molecular weight. In the above formula, M is the absolute molecular weight.

[0582] The eluent was THF containing 5 mmol / L triethylamine.

[0583] Regarding the column, the product names "TSKgel G4000HXL", "TSKgel G5000HXL" and "TSKgel G6000HXL" manufactured by Tosoh Corporation are used together.

[0584] Dissolve 20 mg of the sample to be measured in 10 mL of THF to prepare the test solution. Inject 100 μL of the test solution into the GPC measuring device and perform the measurement at an oven temperature of 40 °C and a THF flow rate of 1 mL / min.

[0585] The absolute molecular weight distribution curve and branching degree distribution curve of the modified conjugated diene polymer were obtained by the above determination. The branching degree (Bn), defined as g'=6Bn / {(Bn+1)(Bn+2)}, was calculated using the shrinkage factor (g').

[0586] (Physical Property 5) Modification Rate

[0587] The modification rate in the modified conjugated diene polymer was determined by column adsorption GPC as follows.

[0588] Column adsorption GPC is a method for determining the modification rate of modified polymers by utilizing the characteristic that the modified basic polymer components in modified conjugated diene polymers are easily adsorbed onto GPC columns filled with silica-based gel.

[0589] A modified conjugated diene polymer was used as the sample, and a sample solution containing the sample and a low molecular weight internal standard polystyrene was analyzed using a polystyrene-based column. The same sample solution was also analyzed using a silica-based column. The difference between the chromatogram obtained using the polystyrene-based column and the chromatogram obtained using the silica-based column was calculated, thereby determining the adsorption amount of the modified conjugated diene polymer on the silica-based column and calculating the modification rate.

[0590] <Preparation of Sample Solution>: Dissolve 10 mg of the sample and 5 mg of standard polystyrene in 10 mL of THF, and use the resulting solution as the sample solution. The modification rate in the modified conjugated diene polymer was determined under the following conditions.

[0591] <GPC Determination Conditions Using Polystyrene Columns>

[0592] GPC measurements were performed using a Tosoh-manufactured product, brand name "HLC-8320GPC", and an RI detector (Tosoh-manufactured product, brand name "HLC8020").

[0593] Using a 5 mmol / L triethylamine-THF solution as the eluent, 10 μL of the sample solution was injected into the GPC device, and the chromatogram was obtained under the conditions of column oven temperature of 40 °C and THF flow rate of 0.35 mL / min.

[0594] Regarding the column, connect three Tosoh-manufactured "TSKgel SuperMultiporeHZ-H" tubes, and connect a Tosoh-manufactured "TSKguardcolumn SuperMP(HZ)-H" tube as a protective column at the front end for use.

[0595] <GPC Determination Conditions Using Silica-Based Columns>

[0596] GPC measurements were performed using a Tosoh-manufactured product, brand name "HLC-8320GPC", and an RI detector (Tosoh-manufactured product, brand name "HLC8020").

[0597] Using THF as the eluent, 50 μL of the sample solution was injected into the device, and the chromatogram was obtained under the conditions of column oven temperature of 40 °C and THF flow rate of 0.5 ml / min.

[0598] Regarding the posts, connect the Agilent products "Zorbax PSM-1000S", "PSM-300S" and "PSM-60S" in sequence, and connect the "DIOL 4.6×12.5mm5micron" as a protective post to the front of them.

[0599] Method for calculating modification rate: For chromatograms obtained using a polystyrene-based column, with the peak area set to 100, calculate the peak area P1 of the sample and the peak area P2 of the standard polystyrene. Similarly, for chromatograms obtained using a silica-based column, with the peak area set to 100, calculate the peak area P3 of the sample and the peak area P4 of the standard polystyrene. The modification rate (mass %) is then calculated using the following formula.

[0600] Modification rate (mass%) = [1 - (P2 × P3) / (P1 × P4)] × 100

[0601] (Where, P1 + P2 = P3 + P4 = 100)

[0602] (Property 6) Amount of bonded vinyl aromatic monomer units (amount of bonded styrene)

[0603] The modified conjugated diene polymer was used as the sample. 100 mg of the sample was dissolved in 100 mL of chloroform and used as the test sample.

[0604] Absorption spectra of each sample were obtained by measuring the absorbance using a spectrophotometer (Shimadzu Corporation, trade name "UV-2450"). The amount of bonded styrene (mass%) relative to 100% mass of the modified conjugated diene polymer was calculated based on the absorbance of the phenyl group derived from styrene in the ultraviolet light (around 254 nm).

[0605] (Property 7) Vinyl bond content in bonded conjugated dienes (1,2-vinyl bond content in bonded butadiene)

[0606] The modified conjugated diene polymer was used as the sample. 50 mg of the sample was dissolved in 10 mL of carbon disulfide and used as the test sample.

[0607] Using a Fourier transform infrared spectrophotometer (trade name "FT-IR230" manufactured by Nippon Spectrophotometer Co., Ltd.), the range was 600–1000 cm⁻¹. -1 The infrared spectra of each sample were measured within the specified range.

[0608] The amount of 1,2-vinyl bonds in bonded butadiene was determined (mol%) according to the Hampton method (RR Hampton, Analytical Chemistry 21, 923 (1949)) based on the absorbance at a specific wavenumber.

[0609] (Property 9) Glass transition temperature

[0610] Modified conjugated diene polymers were used as samples, and DSC measurements were performed using a differential scanning calorimeter (MAC Science, trade name "DSC3200S") according to ISO 22768:2006. DSC curves were recorded while heating from -100°C at a rate of 20°C / min under a helium flow of 50 mL / min. The peak (inflection point) of the differential DSC curve was taken as the glass transition temperature.

[0611] (Physical Property 10) Antioxidant (Stabilizer) Content (Stabilizer Content)

[0612] The content of antioxidants in modified conjugated diene polymers was determined by HPLC as follows.

[0613] The HPLC analysis method is as follows: Using an Agilent Technologies LC1260 Infinity or equivalent, and an Agilent Eclipse Plus C18 column (1.8 μm, 4.6 × 100 mm), 5.0 μL of a sample solution adjusted to a concentration of 100 mg / 10 mL (using a THF:MeOH = 1:1 solvent) was added. The column was operated at 35 °C and a flow rate of 2.5 mL / min. The composition of the developing solvent was changed using THF (tetrahydrofuran) and methanol according to a timetable described later, and separation was performed. Analysis was based on UV-based detection intensity to determine the amount of modified antioxidant added to the modified conjugated diene polymer.

[0614] (Physical Property 11) Nitrogen Atom Content (mass ppm)

[0615] The modified conjugated diene polymer was used as the sample, and the nitrogen content was determined according to JIS-2609: Crude oil and petroleum products - Nitrogen content test method, chemiluminescence method.

[0616] As the measuring device, a trace total nitrogen analyzer (manufactured by Mitsubishi Chemical Analysis Technology Co., Ltd., "TN-2100H") was used.

[0617] As a determination method, the sample is thermally decomposed under argon gas flow and then oxidized by combustion with oxygen. The generated nitrogen monoxide reacts with ozone gas under dehydration conditions. The luminescence intensity at the detected range of 590–2500 nm is measured, and the nitrogen content is determined based on the area value of this luminescence intensity.

[0618] (Physical Property 12) Silicon atom content (ppm by mass)

[0619] 0.5 g of the modified conjugated diene polymer was used as a sample and measured using a UV-Vis spectrophotometer (trade name "UV-1800" manufactured by Shimadzu Corporation) according to JIS K 0101 44.3.1. Quantification was performed by molybdenum blue absorbance spectrophotometry.

[0620] Therefore, if silicon atoms are detected (detection limit 10 ppm by mass), it is determined that silicon atoms are present.

[0621] This confirms that the modified conjugated diene polymers of the examples and comparative examples have silicon atoms.

[0622] (Example 1) Modified conjugated diene polymer (A1)

[0623] Two trough-shaped pressure vessels with agitators and temperature control jackets are connected as polymerization branching reactors. The internal volume of the trough-shaped pressure vessel is 10L, the ratio of its internal height (L) to its diameter (D) (L / D) is 4.0, and it has an inlet at the bottom and an outlet at the top.

[0624] Pre-dehydrated 1,3-butadiene, styrene, and n-hexane were mixed at rates of 18.5 g / min, 6.2 g / min, and 117.4 g / min, respectively, and continuously fed to the bottom of the first reactor. It should be noted that during the above feeding, just before the mixed solution was added to the first reactor, n-butyllithium, used to inertize residual impurities, was continuously added using a static mixer at a rate of 0.096 mmol / min. In addition, while supplying 1,3-butadiene, styrene, n-hexane, and n-butyllithium, the reaction solution was vigorously stirred using a stirrer. Simultaneously, a mixed solution of 2,2-bis(2-tetrahydrofuranyl)propane (a polar compound) and pre-prepared piperidinyllithium (also known as "1-lithium piperidinium," abbreviated as "a-1" in the table) as a polymerization initiator, and n-butyllithium (molar ratio of piperidinyllithium to n-butyllithium was 0.75:0.25) was supplied to the bottom of the first reactor at rates of 0.049 mmol / min and 0.221 mmol / min, respectively. It should be noted that the temperature inside the first reactor was maintained at 82°C.

[0625] The conjugated diene polymer solution generated by polymerization in reactor 1 is continuously drawn from the top of reactor 1 and continuously supplied to the bottom of reactor 2. At the point of complete polymerization stabilization, while copolymerizing 1,3-butadiene with styrene, trimethoxy(4-vinylphenyl)silane (also known as "c-1") as a branching agent is supplied from the bottom of reactor 2 at a rate of 0.011 mmol / min, and further 1,3-butadiene is added at a rate of 6.2 g / min to carry out the polymerization branching process.

[0626] It should be noted that the temperature inside the second reactor was maintained at 86°C. A small amount of the conjugated diene polymer solution was drawn from the outlet of the second reactor, and antioxidant (BHT) was added at a rate of 0.2 g per 100 g of conjugated diene polymer, followed by solvent removal. The resulting conjugated diene polymer was subjected to GPC-based determination of various molecular weights, Mooney viscosity at 110°C, and Mooney stress relaxation rate.

[0627] The physical properties are shown in Tables 1 to 3 (Physical Property 1-1, 1-2, 1-3, Physical Property 2, Physical Property 3).

[0628] Next, the conjugated diene polymer solution flowing from the top of reactor 2 is supplied to a static mixer. Tetra(3-trimethoxysilylpropyl)-1,3-propanediamine (also known as "b-1"), acting as a coupling modifier, is continuously added to the conjugated diene polymer solution flowing continuously in the static mixer at a rate of 0.031 mmol / min, thereby coupling the conjugated diene polymer. At this point, the time up to adding the coupling modifier to the polymer solution flowing out of reactor 2 is 4.8 minutes, and the temperature of the polymer solution at the time of adding the coupling modifier is 68°C. Furthermore, the temperature difference between the polymer solution at the outlet of reactor 2 and the temperature of the polymer solution at the time of adding the coupling modifier is 2°C.

[0629] Next, a hexane solution containing the antioxidant (BHT) was continuously added to the polymer solution flowing out of the static mixer at a concentration of 0.5 parts by mass relative to 100 parts by mass of the conjugated diene polymer, thereby ending the coupling reaction. The solvent was removed by stripping, and the mixture was formed into a briquette, thus obtaining the modified conjugated diene polymer (A1). Various properties of the obtained modified conjugated diene polymer (A1) were measured.

[0630] The measurement results are shown in Table 1.

[0631] (Example 2) Modified conjugated diene polymer (A2)

[0632] b-1, used as a coupling modifier, was supplied at 0.044 mmol / min, otherwise the modified conjugated diene polymer (A2) was obtained in the same manner as in Example 1.

[0633] The properties of the modified conjugated diene polymer (A2) are shown in Table 1.

[0634] (Example 3) Modified conjugated diene polymer (A3)

[0635] b-1, used as a coupling modifier, was supplied at 0.054 mmol / min, otherwise the modified conjugated diene polymer (A3) was obtained in the same manner as in Example 1.

[0636] The properties of the modified conjugated diene polymer (A3) are shown in Table 1.

[0637] (Example 4) Modified conjugated diene polymer (A4)

[0638] b-1, used as a coupling modifier, was supplied at 0.062 mmol / min, otherwise the modified conjugated diene polymer (A4) was obtained in the same manner as in Example 1.

[0639] The properties of the modified conjugated diene polymer (A4) are shown in Table 1.

[0640] (Example 5) Modified conjugated diene polymer (A5)

[0641] b-1, used as a coupling modifier, was supplied at 0.070 mmol / min, otherwise the modified conjugated diene polymer (A5) was obtained in the same manner as in Example 1.

[0642] The properties of the modified conjugated diene polymer (A5) are shown in Table 1.

[0643] (Example 6) Modified conjugated diene polymer (A6)

[0644] A mixed solution of aminolithium / n-butyllithium as a polymerization initiator was supplied at 0.173 mmol / min, 2,2-bis(2-tetrahydrofuranyl)propane as a polar compound was supplied at 0.037 mmol / min, c-1 as a branching agent was supplied at 0.009 mmol / min, and b-1 as a coupling modifier was supplied at 0.054 mmol / min. Otherwise, the modified conjugated diene polymer (A6) was obtained in the same manner as in Example 1.

[0645] The properties of the modified conjugated diene polymer (A6) are shown in Table 1.

[0646] (Example 7) Modified conjugated diene polymer (A7)

[0647] A mixed solution of aminolithium / n-butyllithium as a polymerization initiator was supplied at 0.154 mmol / min, 2,2-bis(2-tetrahydrofuranyl)propane as a polar compound was supplied at 0.037 mmol / min, c-1 as a branching agent was supplied at 0.009 mmol / min, and b-1 as a coupling modifier was supplied at 0.054 mmol / min. Otherwise, the modified conjugated diene polymer (A7) was obtained in the same manner as in Example 1.

[0648] The properties of the modified conjugated diene polymer (A7) are shown in Table 1.

[0649] (Example 8) Modified conjugated diene polymer (A8)

[0650] The modified conjugated diene polymer (A8) was obtained in the same manner as in Example 1, except that 1,3-butadiene was supplied at 16.0 g / min, additional 1,3-butadiene was supplied at 8.6 g / min, and b-1 as a coupling modifier was supplied at 0.054 mmol / min.

[0651] The properties of the modified conjugated diene polymer (A8) are shown in Table 1.

[0652] (Example 9) Modified conjugated diene polymer (A9)

[0653] The modified conjugated diene polymer (A9) was obtained in the same manner as in Example 1, except that 1,3-butadiene was supplied at 13.6 g / min, additional 1,3-butadiene was supplied at 11.1 g / min, and b-1 as a coupling modifier was supplied at 0.054 mmol / min.

[0654] The properties of the modified conjugated diene polymer (A9) are shown in Table 1.

[0655] (Example 10) Modified conjugated diene polymer (A10)

[0656] The modified conjugated diene polymer (A10) was obtained in the same manner as in Example 1, with 1,3-butadiene supplied at 19.7 g / min, styrene supplied at 4.6 g / min, and 2,2-bis(2-tetrahydrofuranyl)propane supplied as a polar compound at 0.080 mmol / min.

[0657] The properties of the modified conjugated diene polymer (A10) are shown in Table 1.

[0658] (Example 11) Modified conjugated diene polymer (A11)

[0659] The modified conjugated diene polymer (A11) was obtained in the same manner as in Example 1, by supplying 1,3-butadiene at 19.7 g / min, styrene at 4.6 g / min, 2,2-bis(2-tetrahydrofuranyl)propane as a polar compound at 0.080 mmol / min, and b-1 as a coupling modifier at 0.044 mmol / min.

[0660] The properties of the modified conjugated diene polymer (A11) are shown in Table 1.

[0661] (Example 12) Modified conjugated diene polymer (A12)

[0662] The modified conjugated diene polymer (A12) was obtained in the same manner as in Example 1, by supplying 1,3-butadiene at 19.7 g / min, styrene at 4.6 g / min, 2,2-bis(2-tetrahydrofuranyl)propane as a polar compound at 0.080 mmol / min, and b-1 as a coupling modifier at 0.054 mmol / min.

[0663] The properties of the modified conjugated diene polymer (A12) are shown in Table 1.

[0664] (Example 13) Modified conjugated diene polymer (A13)

[0665] The modified conjugated diene polymer (A13) was obtained in the same manner as in Example 1, by supplying 1,3-butadiene at 19.7 g / min, styrene at 4.6 g / min, 2,2-bis(2-tetrahydrofuranyl)propane as a polar compound at 0.080 mmol / min, and b-1 as a coupling modifier at 0.062 mmol / min.

[0666] The properties of the modified conjugated diene polymer (A13) are shown in Table 1.

[0667] (Example 14) Modified conjugated diene polymer (A14)

[0668] The modified conjugated diene polymer (A14) was obtained by feeding 1,3-butadiene at 19.7 g / min, styrene at 4.6 g / min, 2,2-bis(2-tetrahydrofuranyl)propane as a polar compound at 0.080 mmol / min, and b-1 as a coupling modifier at 0.070 mmol / min, otherwise the same as in Example 1. The properties of the modified conjugated diene polymer (A14) are shown in Table 1.

[0669] (Example 15) Modified conjugated diene polymer (A15)

[0670] 1,3-Butadiene was supplied at 20.8 g / min, styrene at 6.9 g / min, 2,2-bis(2-tetrahydrofuranyl)propane (as a polar compound) at 0.104 mmol / min, additional 1,3-butadiene at 6.9 g / min, c-1 (as a branching agent) at 0.011 mmol / min, and b-1 (as a coupling modifier) ​​at 0.031 mmol / min. The temperature of the first reactor was 68°C, and the temperature of the second reactor was 70°C. Otherwise, the modified conjugated diene polymer (A15) was obtained in the same manner as in Example 1. The properties of the modified conjugated diene polymer (A15) are shown in Table 1.

[0671] (Example 16) Modified conjugated diene polymer (A16)

[0672] 1,3-Butadiene was supplied at 20.8 g / min, styrene at 6.9 g / min, 2,2-bis(2-tetrahydrofuranyl)propane (as a polar compound) at 0.104 mmol / min, additional 1,3-butadiene at 6.9 g / min, c-1 (as a branching agent) at 0.011 mmol / min, and b-1 (as a coupling modifier) ​​at 0.044 mmol / min. The temperature of the first reactor was 68°C, and the temperature of the second reactor was 70°C. Otherwise, the modified conjugated diene polymer (A16) was obtained in the same manner as in Example 1. The properties of the modified conjugated diene polymer (A16) are shown in Table 2.

[0673] (Example 17) Modified conjugated diene polymer (A17)

[0674] 1,3-Butadiene was supplied at 20.8 g / min, styrene at 6.9 g / min, 2,2-bis(2-tetrahydrofuranyl)propane (as a polar compound) at 0.104 mmol / min, additional 1,3-butadiene at 6.9 g / min, c-1 (as a branching agent) at 0.011 mmol / min, and b-1 (as a coupling modifier) ​​at 0.054 mmol / min. The temperature of the first reactor was 68°C, and the temperature of the second reactor was 70°C. Otherwise, the modified conjugated diene polymer (A17) was obtained in the same manner as in Example 1. The properties of the modified conjugated diene polymer (A17) are shown in Table 2.

[0675] (Example 18) Modified conjugated diene polymer (A18)

[0676] 1,3-Butadiene was supplied at 20.8 g / min, styrene at 6.9 g / min, 2,2-bis(2-tetrahydrofuranyl)propane (as a polar compound) at 0.104 mmol / min, additional 1,3-butadiene at 6.9 g / min, c-1 (as a branching agent) at 0.011 mmol / min, and b-1 (as a coupling modifier) ​​at 0.062 mmol / min. The temperature of the first reactor was 68°C, and the temperature of the second reactor was 70°C. Otherwise, the modified conjugated diene polymer (A18) was obtained in the same manner as in Example 1. The properties of the modified conjugated diene polymer (A18) are shown in Table 2.

[0677] (Example 19) Modified conjugated diene polymer (A19)

[0678] 1,3-Butadiene was supplied at 20.8 g / min, styrene at 6.9 g / min, 2,2-bis(2-tetrahydrofuranyl)propane (as a polar compound) at 0.104 mmol / min, additional 1,3-butadiene at 6.9 g / min, c-1 (as a branching agent) at 0.011 mmol / min, and b-1 (as a coupling modifier) ​​at 0.070 mmol / min. The temperature of the first reactor was 68°C, and the temperature of the second reactor was 70°C. Otherwise, the modified conjugated diene polymer (A19) was obtained in the same manner as in Example 1. The properties of the modified conjugated diene polymer (A19) are shown in Table 2.

[0679] (Example 20) Modified conjugated diene polymer (A20)

[0680] 1,3-Butadiene was supplied at 16.2 g / min, styrene at 9.2 g / min, 2,2-bis(2-tetrahydrofuranyl)propane (as a polar compound) at 0.045 mmol / min, additional 1,3-butadiene at 5.4 g / min, c-1 (as a branching agent) at 0.011 mmol / min, and b-1 (as a coupling modifier) ​​at 0.031 mmol / min. The temperature of the first reactor was 68°C, and the temperature of the second reactor was 74°C. Otherwise, the modified conjugated diene polymer (A20) was obtained in the same manner as in Example 1. The properties of the modified conjugated diene polymer (A20) are shown in Table 2.

[0681] (Example 21) Modified conjugated diene polymer (A21)

[0682] 1,3-Butadiene was supplied at 16.2 g / min, styrene at 9.2 g / min, 2,2-bis(2-tetrahydrofuranyl)propane (as a polar compound) at 0.045 mmol / min, additional 1,3-butadiene at 5.4 g / min, c-1 (as a branching agent) at 0.011 mmol / min, and b-1 (as a coupling modifier) ​​at 0.044 mmol / min. The temperature of the first reactor was 68°C, and the temperature of the second reactor was 74°C. Otherwise, the modified conjugated diene polymer (A21) was obtained in the same manner as in Example 1. The properties of the modified conjugated diene polymer (A21) are shown in Table 2.

[0683] (Example 22) Modified conjugated diene polymer (A22)

[0684] 1,3-Butadiene was supplied at 16.2 g / min, styrene at 9.2 g / min, 2,2-bis(2-tetrahydrofuranyl)propane (as a polar compound) at 0.045 mmol / min, additional 1,3-butadiene at 5.4 g / min, c-1 (as a branching agent) at 0.011 mmol / min, and b-1 (as a coupling modifier) ​​at 0.054 mmol / min. The temperature of the first reactor was 68 °C, and the temperature of the second reactor was 74 °C. Otherwise, the modified conjugated diene polymer (A22) was obtained in the same manner as in Example 1. The properties of the modified conjugated diene polymer (A22) are shown in Table 2.

[0685] (Example 23) Modified conjugated diene polymer (A23)

[0686] 1,3-Butadiene was supplied at 16.2 g / min, styrene at 9.2 g / min, 2,2-bis(2-tetrahydrofuranyl)propane (as a polar compound) at 0.045 mmol / min, additional 1,3-butadiene at 5.4 g / min, c-1 (as a branching agent) at 0.011 mmol / min, and b-1 (as a coupling modifier) ​​at 0.062 mmol / min. The temperature of the first reactor was 68°C, and the temperature of the second reactor was 74°C. Otherwise, the modified conjugated diene polymer (A23) was obtained in the same manner as in Example 1. The properties of the modified conjugated diene polymer (A23) are shown in Table 2.

[0687] (Example 24) Modified conjugated diene polymer (A24)

[0688] 1,3-Butadiene was supplied at 16.2 g / min, styrene at 9.2 g / min, 2,2-bis(2-tetrahydrofuranyl)propane (as a polar compound) at 0.045 mmol / min, additional 1,3-butadiene at 5.4 g / min, c-1 (as a branching agent) at 0.011 mmol / min, and b-1 (as a coupling modifier) ​​at 0.070 mmol / min. The temperature of the first reactor was 68°C, and the temperature of the second reactor was 74°C. Otherwise, the modified conjugated diene polymer (A24) was obtained in the same manner as in Example 1. The properties of the modified conjugated diene polymer (A24) are shown in Table 2.

[0689] (Example 25) Modified conjugated diene polymer (A25)

[0690] 1,3-Butadiene was supplied at 17.2 g / min, styrene at 5.7 g / min, 2,2-bis(2-tetrahydrofuranyl)propane (as a polar compound) at 0.060 mmol / min, additional 1,3-butadiene at 7.9 g / min, c-1 (as a branching agent) at 0.011 mmol / min, and b-1 (as a coupling modifier) ​​at 0.031 mmol / min. The temperature of the first reactor was set to 83°C, and the temperature of the second reactor was set to 88°C. Otherwise, the modified conjugated diene polymer (A25) was obtained in the same manner as in Example 1. The properties of the modified conjugated diene polymer (A25) are shown in Table 2.

[0691] (Example 26) Modified conjugated diene polymer (A26)

[0692] 1,3-Butadiene was supplied at 17.2 g / min, styrene at 5.7 g / min, 2,2-bis(2-tetrahydrofuranyl)propane (as a polar compound) at 0.060 mmol / min, additional 1,3-butadiene at 7.9 g / min, c-1 (as a branching agent) at 0.011 mmol / min, and b-1 (as a coupling modifier) ​​at 0.044 mmol / min. The temperature of the first reactor was set to 83°C, and the temperature of the second reactor was set to 88°C. Otherwise, the modified conjugated diene polymer (A26) was obtained in the same manner as in Example 1. The properties of the modified conjugated diene polymer (A26) are shown in Table 2.

[0693] (Example 27) Modified conjugated diene polymer (A27)

[0694] 1,3-Butadiene was supplied at 17.2 g / min, styrene at 5.7 g / min, 2,2-bis(2-tetrahydrofuranyl)propane (as a polar compound) at 0.060 mmol / min, additional 1,3-butadiene at 7.9 g / min, c-1 (as a branching agent) at 0.011 mmol / min, and b-1 (as a coupling modifier) ​​at 0.054 mmol / min. The temperature of the first reactor was set to 83°C, and the temperature of the second reactor was set to 88°C. Otherwise, the modified conjugated diene polymer (A27) was obtained in the same manner as in Example 1. The properties of the modified conjugated diene polymer (A27) are shown in Table 2.

[0695] (Example 28) Modified conjugated diene polymer (A28)

[0696] 1,3-Butadiene was supplied at 17.2 g / min, styrene at 5.7 g / min, 2,2-bis(2-tetrahydrofuranyl)propane (as a polar compound) at 0.060 mmol / min, additional 1,3-butadiene at 7.9 g / min, c-1 (as a branching agent) at 0.011 mmol / min, and b-1 (as a coupling modifier) ​​at 0.062 mmol / min. The temperature of the first reactor was set to 83°C, and the temperature of the second reactor was set to 88°C. Otherwise, the modified conjugated diene polymer (A28) was obtained in the same manner as in Example 1. The properties of the modified conjugated diene polymer (A28) are shown in Table 2.

[0697] (Example 29) Modified conjugated diene polymer (A29)

[0698] 1,3-Butadiene was supplied at 17.2 g / min, styrene at 5.7 g / min, 2,2-bis(2-tetrahydrofuranyl)propane (as a polar compound) at 0.060 mmol / min, additional 1,3-butadiene at 7.9 g / min, c-1 (as a branching agent) at 0.011 mmol / min, and b-1 (as a coupling modifier) ​​at 0.070 mmol / min. The temperature of the first reactor was set to 83°C, and the temperature of the second reactor was set to 88°C. Otherwise, the modified conjugated diene polymer (A29) was obtained in the same manner as in Example 1. The properties of the modified conjugated diene polymer (A29) are shown in Table 2.

[0699] (Comparative Example 1) Modified conjugated diene polymer (B1)

[0700] Except for the use of n-butyllithium as a polymerization initiator, the modified conjugated diene polymer (B1) was obtained in the same manner as in Example 1. The properties of the modified conjugated diene polymer (B1) are shown in Table 3.

[0701] (Comparative Example 2) Modified conjugated diene polymer (B2)

[0702] The modified conjugated diene polymer (B2) was obtained by supplying n-butyllithium as a polymerization initiator at 0.071 mmol / min, b-1 as a coupling modifier at 0.054 mmol / min, 2,2-bis(2-tetrahydrofuranyl)propane as a polar compound at 0.055 mmol / min, c-1 as a branching agent at 0.0016 mmol / min, and b-1 as a coupling modifier at 0.071 mmol / min, otherwise the same as in Example 1. The properties of the modified conjugated diene polymer (B2) are shown in Table 3.

[0703] (Comparative Example 3) Modified conjugated diene polymer (B3)

[0704] Using n-butyllithium as a polymerization initiator, the temperature in the first reactor was maintained at 92°C and the temperature in the second reactor was maintained at 95°C. Otherwise, the modified conjugated diene polymer (B3) was obtained in the same manner as in Example 1. The properties of the modified conjugated diene polymer (B3) are shown in Table 3.

[0705] (Comparative Example 4) Modified conjugated diene polymer (B4)

[0706] Using n-butyllithium as a polymerization initiator, 1,3-butadiene was supplied at 16.2 g / min, styrene at 9.24 g / min, 2,2-bis(2-tetrahydrofuranyl)propane (a polar compound) at 0.104 mmol / min, additional 1,3-butadiene at 5.4 g / min, c-1 (a branching agent) at 0.011 mmol / min, and b-1 (a coupling modifier) ​​at 0.054 mmol / min. The temperature of the first reactor was 68°C, and the temperature of the second reactor was 70°C. Otherwise, the modified conjugated diene polymer (B4) was obtained in the same manner as in Example 1. The properties of the modified conjugated diene polymer (B4) are shown in Table 3.

[0707] [Table 1]

[0708] [Table 2]

[0709] [Table 3]

[0710] [Evaluation of briquetted modified conjugated diene polymers]

[0711] (Evaluation 1) Appearance of the compact (whether there are cracks / damage)

[0712] Regarding the briquettes of modified conjugated diene polymers manufactured by the methods shown in the examples and comparative examples, the appearance of external cracks, damage, etc., was visually observed. Based on the following criteria, each evaluator was rated out of 4 points. The appearance of the briquettes is an indicator of the briquette formability of the modified conjugated diene polymers.

[0713] IV: The particles failed to aggregate and could not be formed into briquettes.

[0714] III: Although it can be formed into a block, breakage has been observed over time.

[0715] II: Less than 5% of cracks and damage were observed on the surface of the compact.

[0716] I: No cracks or damage were observed on the surface of the compact.

[0717] [Preparation and Evaluation of Rubber Compositions]

[0718] (Evaluation of rubber compositions)

[0719] Using the modified conjugated diene polymers A1-A29 and B1-B4 shown in Tables 1-7 as raw materials, various rubber compositions were obtained according to the following proportions.

[0720] • Modified conjugated diene polymers (any one of A1–A29 and B1–B4): 70 parts by weight (de-oiled)

[0721] Butadiene rubber (trade name "BR150" manufactured by Ube Industries): 30 parts by weight

[0722] • Silica (manufactured by Evonik Degussa under the trade name "Ultrasil 7000GR"), with a nitrogen adsorption specific surface area of ​​170 m². 2 / g): 75.0 parts by weight

[0723] • Carbon black (trade name "SEAST KH(N339)" manufactured by Tokai Carbon Co., Ltd.): 5.0 parts by weight

[0724] • Silane coupling agent (trade name "Si75", bis(triethoxysilylpropyl) disulfide, manufactured by Evonik Degussa): 6.0 parts by weight

[0725] • S-RAE oil (trade name "Process NC140" manufactured by JX Nippon Oil & Gas Co., Ltd.): 32.0 parts by weight

[0726] Zinc white: 2.5 parts by weight

[0727] Stearic acid: 2.0 parts by weight

[0728] • Anti-aging agent (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine): 2.0 parts by weight

[0729] • Sulfur: 1.7 parts by weight

[0730] • Vulcanization accelerator 1 (N-cyclohexyl-2-benzothiazolyl sulfinamide): 1.7 parts by weight

[0731] • Vulcanization accelerator 2 (diphenylguanidine): 2.0 parts by weight

[0732] Specifically, the above materials are mixed using the following method to obtain a rubber composition. Using a closed mixer (0.5L capacity) equipped with a temperature control device, as the first stage of mixing, modified conjugated diene polymers (any of A1-A29 or B1-B4), butadiene rubber, fillers (silica, carbon black), silane coupling agent, S-RAE oil, zinc oxide, and stearic acid are mixed at a filler ratio of 65% and a rotor speed of 30-50 rpm. During this process, the temperature of the closed mixer is controlled to obtain each rubber composition (mixture) with a discharge temperature of 155-160°C.

[0733] Next, as the second stage of mixing, the obtained compound was cooled to room temperature, and an anti-aging agent was added. To improve the dispersion of silica, mixing was performed again under the same conditions as in the first stage. In this case, the discharge temperature of the compound was also adjusted to 155–160°C by controlling the temperature of the mixer. After cooling, as the third stage of mixing, sulfur, vulcanization accelerator 1, and vulcanization accelerator 2 were added and mixed in an open mill set to 70°C. Subsequently, molding was performed, and vulcanization was carried out at 160°C using a vulcanizing press for 20 minutes. The rubber composition before vulcanization and the rubber composition after vulcanization were evaluated.

[0734] Specifically, the evaluation was conducted using the methods described below. The evaluation results are shown in Tables 4 to 7.

[0735] (Evaluation 2) Emission aggregation

[0736] Regarding the unvulcanized modified conjugated diene polymers manufactured by the methods shown in the examples and comparative examples, the aggregates (shapes) were visually observed immediately after discharge from the pressure kneader (right after discharge from the pressure kneader during the first mixing stage). Based on the following criteria, each evaluator was evaluated with a maximum score of 4 points. Aggregability is an indicator of the processability of the vulcanizate.

[0737] IV: Less than 60% of the end portion of the sheet is smooth, making it very difficult to process.

[0738] III: More than 60% but less than 80% of the end portion of the sheet is smooth, resulting in poor processability.

[0739] II: More than 80% and less than 90% of the end portion of the sheet is smooth, resulting in excellent processability.

[0740] I: More than 90% of the end portion of the sheet is smooth, resulting in excellent processability.

[0741] (Evaluation 3, 4) Viscoelastic parameters (fuel efficiency and wet grip)

[0742] Viscoelastic parameters were measured using an ARES viscoelastic testing machine manufactured by Rheometric Scientific in torsional vibration mode. The results for the rubber composition of Comparative Example 1 were set to 100, and each measured value was indexed. Here, tanδ, measured at 50°C, 10Hz, and 3% strain, was used as an indicator of low hysteresis loss, i.e., fuel efficiency, and the results for Comparative Example 1 were standardized to 100. A higher index indicates better fuel efficiency, and a value exceeding 65 was evaluated as excellent fuel efficiency. Additionally, tanδ, measured at 0°C, 10Hz, and 1% strain, was used as an indicator of wet grip, and the results for Comparative Example 1 were standardized to 100. A higher index indicates better wet grip, and a value exceeding 65 was evaluated as excellent wet grip.

[0743] (Evaluation 5, 6) Tensile strength and elongation at break

[0744] Tensile strength and elongation at break were determined according to the tensile test method of JIS K6251. The result of Comparative Example 1 was set as 100, and all measured values ​​were standardized. The larger the value, the better the tensile strength and elongation at break, and the superior destructive characteristics.

[0745] (Evaluation 7) Abrasion resistance

[0746] The abrasion resistance was measured using an Akron abrasion tester (manufactured by Yasuda Seiki Co., Ltd.) according to JIS K6264-2 after a load of 44.4 N and 1000 revolutions. The result of Comparative Example 1 was set as 100, and all measured values ​​were standardized. The higher the value, the better the abrasion resistance. Values ​​exceeding 80 were evaluated as excellent abrasion resistance.

[0747] [Table 4]

[0748] [Table 5]

[0749] [Table 6]

[0750] [Table 7]

[0751] The modified conjugated diene polymer of this invention exhibits excellent briquetting properties, processability, and fuel efficiency. Furthermore, it is known that its sulfides demonstrate an excellent balance of wear resistance, destructive characteristics, and low hysteresis loss.

[0752] The entire disclosure of Japanese Patent Application No. 2023-126215, filed on August 2, 2023, is incorporated herein by reference. All documents, patent applications, and technical standards described in this specification are incorporated herein by reference to the same extent as those documents, patent applications, and technical standards specifically and separately described and incorporated herein by reference.

[0753] Industrial applicability

[0754] The modified conjugated diene polymers and their manufacturing methods, as well as the modified conjugated diene polymer compositions and rubber compositions of the present invention, have industrial applicability in applications such as tires, resin modification, automotive interior and exterior trims, vibration damping rubber, and footwear, due to the excellent molding retention, excellent balance of abrasion resistance, destructive properties, and low hysteresis loss of the modified conjugated diene polymers.

Claims

1. A modified conjugated diene polymer that satisfies the following conditions (i) to (vi): <Condition (i)> The Mooney viscosity, measured at 100°C, is between 100 and 180. <Condition(ii)> The Mooney stress relaxation rate, measured at 100℃, ranged from 0.10 to 0.

40. <Condition (iii)> The glass transition temperature is -95℃ to -45℃; <Condition(iV)> The content of silicon atoms relative to the total amount of the modified conjugated diene polymer is more than 100 ppm by mass; <Condition(V)> The nitrogen atom content relative to the total amount of the modified conjugated diene polymer is above 50 ppm by mass; <Condition(Vi)> The antioxidant content is less than 0.5 parts by mass relative to 100 parts by mass of the modified conjugated diene polymer.

2. The modified conjugated diene polymer as described in claim 1, wherein, The Mooney viscosity of the condition (i) is 105 or higher and 180 or lower when measured at 100°C.

3. The modified conjugated diene polymer as described in claim 1, wherein, The Mooney stress relaxation rate measured at 100°C under condition (ii) is 0.10 to 0.

35.

4. The modified conjugated diene polymer as described in claim 1, wherein, The glass transition temperature of condition (iii) is -95℃ to -55℃.

5. The modified conjugated diene polymer according to claim 1, wherein, The nitrogen atom content of the <condition (V)> is above 80 ppm by mass relative to the total amount of the modified conjugated diene polymer.

6. The modified conjugated diene polymer according to claim 1, wherein, The molecular weight distribution (PDI; MWD) is 1.4–2.

5.

7. The modified conjugated diene polymer according to claim 1, wherein, The 1,2-vinyl bond content is less than 45.0 mol% relative to the total mass of the modified conjugated diene polymer.

8. The modified conjugated diene polymer according to claim 1, wherein, The degree of branching (Bn) obtained by the GPC-light scattering method with a viscosity detector is greater than 2.

9. The modified conjugated diene polymer according to claim 1, wherein, It has a nitrogen atom at at least one end. A branch with at least one star-shaped structure, The star-shaped structure has branches derived from vinyl monomers containing alkoxysilyl or halosilyl groups. The portion derived from the vinyl monomer containing alkoxysilyl or halosilyl groups has a further main-chain branched structure and a coupling structure centered on a nitrogen-containing alkoxysilane substituent.

10. The modified conjugated diene polymer according to claim 1, wherein, In the coupling structure centered on the nitrogen-containing alkoxysilane substituent, the nitrogen-containing alkoxysilane modifier residue has at least four silicon atoms, as well as alkoxy and / or hydroxyl groups. The modified conjugated diene polymer chain with a main-chain branched structure is bonded to the silicon atom, and the number of alkoxy groups and / or hydroxyl groups in the modifier residues is on average greater than the number of silicon atoms.

11. A briquette containing 100 parts by weight of the modified conjugated diene polymer of claim 1 and less than 2 parts by weight of a softener component.

12. A briquette containing 100 parts by weight of the modified conjugated diene polymer of claim 1, and less than 1 part by weight of a softener component.

13. A method for manufacturing a modified conjugated diene polymer, which is the method for manufacturing the modified conjugated diene polymer according to claim 1, comprising the following steps: A process of polymerizing at least a conjugated diene compound in the presence of an organolithium compound having at least one nitrogen atom within the molecule; and The branching process of obtaining branched conjugated diene polymers with a main-chain branched structure using a branching agent. In the process of coupling the branched conjugated diene polymer with a coupling agent and / or modifying it with a modifier having nitrogen-containing atomic groups, the coupling agent and / or the modifier are added in excess.

14. A rubber composition comprising: 100 parts by weight of rubber component; and Filler material of 5.0 to 150 parts by weight The rubber component comprises, relative to 100 parts by mass of the total rubber component, at least 10 parts by mass of the modified conjugated diene polymer of claim 1 or the briquettes of claim 11.

15. A tire comprising the rubber composition of claim 14.

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