Conjugated diene polymer and rubber composition

Abstract

The present invention relates to a conjugated diene-based polymer in which physical properties other than processability of the conjugated diene-based polymer are maintained at the level of a highly linear conjugated diene-based polymer by introducing a branch chain into a linear conjugated diene-based polymer, the present invention relates to a conjugated diene-based polymer, and more particularly, to a conjugated diene-based polymer, whereby improved processability is exhibited while the mixing properties in a rubber composition are maintained at a high level, and to a rubber composition comprising the same.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Korean Patent Application No. 10-2023-0149216, filed on November 1, 2023, and Korean Patent Application No. 10-2024-0028978, filed on February 28, 2024, in the Korean Intellectual Property Office, the contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to a conjugated diene polymer and a rubber composition containing the same. Background Art

[0004] Recently, with the increasing concern for energy conservation and environmental issues, there is a need to improve the fuel efficiency of automobiles. As one of the methods to achieve this demand, a method has been proposed to increase the cis bond content and linearity of polybutadiene in a tire-forming rubber composition while narrowing the molecular weight distribution.

[0005] Polybutadiene may be prepared using a Ziegler-Natta catalyst, and the Ziegler-Natta catalyst is prepared by activating an organic acid metal compound with an alkylaluminum and a halogenated alkylaluminum compound, and reacting the prepared catalyst with a 1,3-butadiene monomer to prepare polybutadiene.

[0006] Here, the organic acid metal compound includes titanium, nickel, cobalt and lanthanum compounds, and lanthanide rare earth element compounds are mainly used from the viewpoint of increasing the cis bond content and linearity of polybutadiene while narrowing the molecular weight distribution.

[0007] Representative examples of lanthanide rare earth element compounds include neodymium compounds, with a specific example being NdV (neodymium neodecanoate). Lanthanide rare earth element compounds are activated by alkylation with an alkylaluminum compound and then halogenation with a haloalkylaluminum compound. To stabilize the catalyst, 1,3-butadiene monomer is added during the alkylation reaction for pre-preparation.

[0008] However, polybutadiene produced by a catalyst produced using a lanthanide rare earth element compound (particularly a neodymium-based compound) has high physical properties but high linearity, and thus poor processability.

[0009] [Prior art literature]

[0010] [Patent Document]

[0011] (Patent Document 1) US 9056303 B2 Summary of the Invention

[0012] Technical issues

[0013] The problem to be solved by the present invention is to improve processability while maintaining the physical properties of a conjugated diene-based polymer at the level of high linear polybutadiene.

[0014] That is, in order to solve the problems mentioned in the background of the present invention, the present invention aims to provide a conjugated diene-based polymer that maintains the physical properties of the conjugated diene-based polymer other than processability at the level of a high linear conjugated diene-based polymer, thereby improving the processability while maintaining the mixing property in the rubber composition at a high level.

[0015] Furthermore, the present invention aims to provide a rubber composition comprising a conjugated diene-based polymer.

[0016] Technical Solution

[0017] In order to solve the above-mentioned problems, the present invention provides a conjugated diene polymer and a rubber composition.

[0018] (1) The present invention provides a conjugated diene polymer comprising conjugated diene monomer units, wherein the conjugated diene monomer units have a cis bond content of 95.0 wt % or more, a molecular weight distribution (Mw / Mn) of 2.3 to 2.8, and a height retention (ΔH) calculated by the following equation 1: @20℃ ) is more than 30%.

[0019] [Equation 1]

[0020] ΔH @20℃ (%)=(H 8@20℃ / H 0@20℃ )×100

[0021] In Equation 1,

[0022] H 0@20℃ The initial height is measured by molding 2.5 g of a conjugated diene-based polymer into a cylindrical shape having a diameter of 15 mm and a height of 12 mm at 100° C. to prepare a sample, and then cooling the sample to a temperature of 20° C., and

[0023] H 8@20℃ It is the height of the sample measured after a load of 5 kg is applied to the upper surface of the sample for 8 minutes while maintaining a temperature of 20°C.

[0024] (2) The present invention provides a conjugated diene polymer according to (1), wherein the height retention (ΔH) calculated by Equation 1 @20℃ ) is more than 35%.

[0025] (3) The present invention provides a conjugated diene polymer according to (1) or (2), wherein the height retention (ΔH) calculated by the following equation 2 is: @40℃) is above 18%.

[0026] [Equation 2]

[0027] ΔH @40℃ (%)=(H 8@40℃ / H 0@40℃ )×100

[0028] In Equation 2,

[0029] H 0@40℃ The initial height is measured by molding 2.5 g of a conjugated diene-based polymer into a cylindrical shape having a diameter of 15 mm and a height of 12 mm at 100° C. to prepare a sample, and then cooling the sample to a temperature of 40° C., and

[0030] H 8@40℃ It is the height of the sample measured after a load of 5 kg is applied to the upper surface of the sample for 8 minutes while maintaining a temperature of 40°C.

[0031] (4) The present invention provides a conjugated diene polymer according to (3), wherein the height retention (ΔH) calculated by equation 2 is @40℃ ) is more than 24%.

[0032] (5) The present invention provides the conjugated diene-based polymer according to any one of (1) to (4), wherein the β value measured at 100° C. is 0.2 or less.

[0033] (6) The present invention provides the conjugated diene-based polymer according to any one of (1) to (5), wherein the molecular weight distribution (Mw / Mn) is 2.5 to 2.8.

[0034] (7) The present invention provides a conjugated diene-based polymer according to any one of (1) to (6), wherein the Mooney viscosity (ML1+4@100°C) measured at 100°C is 40 to 50.

[0035] (8) The present invention provides a conjugated diene polymer according to any one of (1) to (7), wherein the weight average molecular weight of the conjugated diene polymer is 500,000 g / mol to 800,000 g / mol.

[0036] (9) The present invention provides a rubber composition comprising the conjugated diene-based polymer according to any one of (1) to (8).

[0037] Beneficial effects

[0038] The conjugated diene polymer of the present invention exhibits improved processability while maintaining high incorporation properties in the rubber composition by introducing branches into the linear conjugated diene polymer so as to maintain the physical properties of the conjugated diene polymer other than processability at the level of the high linear conjugated diene polymer. DETAILED DESCRIPTION

[0039] Hereinafter, the present invention will be described in more detail to help understanding of the present invention.

[0040] It will be understood that the words or terms used in the present invention and claims should not be interpreted as having the meaning defined in commonly used dictionaries. Based on the principle that the inventor can appropriately define the meaning of the words or terms to best explain the present invention, the words or terms should be interpreted as having a meaning consistent with their meaning in the technical concept of the present invention.

[0041] Measurement method

[0042] In this specification, "1,4-cis bond content (wt%)" is the content of cis-1,4 bonds in the conjugated diene group measured by Fourier transform infrared spectroscopy (FT-IR). Using carbon disulfide in the same measuring cell as a blank control, the FT-IR transmission spectrum of a carbon disulfide solution of a conjugated diene polymer prepared at a concentration of 5 mg / mL was measured, and the 1130 cm-1 wavelength of the measured spectrum was used. -1 The largest peak near (a, baseline), 967 cm indicating trans-1,4 bond -1 The smallest peak near (b), 911 cm indicating vinyl bond -1 The minimum peak near (c) and 736 cm indicating cis-1,4 bond -1 The contents were obtained from the minimum peak (d) near the RI.

[0043] In this specification, after the polymer is allowed to stand at room temperature (23±3°C) for more than 30 minutes, 27±3 g is collected and filled into the mold cavity, and torque is applied by operating the pressure plate, using a Monsanto MV2000E large rotor at 100°C and a rotor speed of 2±0.02 rpm to "measure the Mooney viscosity (ML1+4, @100°C)".

[0044] In this specification, "β-value" represents the degree of branching of a polymer as a function of frequency. A smaller β-value indicates an increase in the degree of branching, while a larger value indicates a decrease in the degree of branching. By using Montech's D-RPA3000 (rubber processing analyzer), tan δ was measured in a frequency sweep range of 0 to 100 Hz, a static strain of 3%, a dynamic strain of 0.25% and a measurement temperature of 100°C, and the slope of d(log(tan δ)) / d(log(freq)) was expressed as the β-value. Here, tan δ is an indicator indicating the overall viscoelastic properties, and is a value expressed as the ratio of the viscous modulus (G") to the elastic modulus (G').

[0045] In this specification, "weight average molecular weight (Mw)", "number average molecular weight (Mn)" and "molecular weight distribution (MWD)" are measured by gel permeation chromatography (GPC) after dissolving the polymer in tetrahydrofuran (THF) at 40°C for 30 minutes. In this case, a combination of two PLgel Olexis columns and a PLgel mixed-C column from Polymer Laboratories was used. In addition, all newly replaced columns used mixed bed columns, and polystyrene was used as the gel permeation chromatography standard material (GPC standard material).

[0046] In this specification, the viscoelastic analysis according to frequency change was measured using a DHR-2 rheometer from TA Instruments and parallel plates with a diameter of 8 mm at 120° C., 0.1% strain, and an angular frequency of 0.01 to 100 rad / s.

[0047] Conjugated diene polymers

[0048] The present invention provides a conjugated diene-based polymer having improved processing characteristics while maintaining the excellent physical properties of highly linear conjugated diene-based polymers in terms of tensile properties, viscoelastic properties, and wear resistance.

[0049] According to one embodiment of the present invention, the conjugated diene polymer may be a linear conjugated diene polymer into which a branched chain is introduced. In this case, the branched chain is a branched chain formed without adding a monomer or modifier containing a branched chain, and in the present invention, the branched chain is defined based on the following β value and the height retention rate calculated by Equation 1.

[0050] According to one embodiment of the present invention, the conjugated diene polymer may include a conjugated diene monomer unit, have a 1,4-cis bond content of 95.0 wt % or more, a molecular weight distribution (Mw / Mn) of 2.3 to 2.8, and a height retention rate (ΔH) calculated by Equation 1. @20℃) is more than 30%.

[0051] [Equation 1]

[0052] ΔH @20℃ (%)=(H 8@20℃ / H 0@20℃ )×100

[0053] In Equation 1,

[0054] H 0@20℃ The initial height is measured by molding 2.5 g of a conjugated diene-based polymer into a cylindrical shape having a diameter of 15 mm and a height of 12 mm at 100° C. to prepare a sample, and then cooling the sample to a temperature of 20° C., and

[0055] H 8@20℃ It is the height of the sample measured after a load of 5 kg is applied to the upper surface of the sample for 8 minutes while maintaining the temperature at 20°C.

[0056] Polybutadiene is usually prepared by polymerizing 1,3-butadiene monomer using a Ziegler-Natta catalyst, and the Ziegler-Natta catalyst is prepared by activating an organic acid metal compound with an aluminum alkyl and a haloalkyl aluminum compound. Here, lanthanide rare earth element compounds (such as neodymium compounds) are widely used as one of the organic acid metal compounds, and after alkylation using an aluminum alkyl compound, the organic acid metal compound is activated by a halogenation reaction using a haloalkyl aluminum compound, and in order to stabilize the catalyst, 1,3-butadiene monomer is sometimes added during the alkylation reaction to be pre-prepared. However, the polybutadiene prepared by the catalyst using a lanthanide rare earth element compound (particularly a neodymium compound) has high mixing properties, such as tensile properties, viscoelastic properties and wear resistance, but has a poor mixing processability due to high linearity.

[0057] The conjugated diene polymer of the present invention is prepared using a lanthanide rare earth element compound as a main catalyst, and by controlling the catalyst components and polymerization conditions, side chains are introduced into the structure of the polymer chain formed by polymerization, thereby improving the mixing processability while maintaining the excellent mixing properties originally exhibited by the high linearity, such as tensile properties, viscoelastic properties and wear resistance.

[0058] According to one embodiment of the present invention, the conjugated diene polymer may include a conjugated diene monomer unit, and the 1,4-cis bond content may be 95.0 wt % or more, the molecular weight distribution (Mw / Mn) may be 2.3 to 2.8, and the height retention rate (ΔH) calculated by the above equation 1 may be @20℃ ) is more than 30%.

[0059] According to one embodiment of the present invention, the conjugated diene polymer may include a conjugated diene monomer unit, which refers to a repeating unit formed by polymerizing a conjugated diene monomer.

[0060] According to one embodiment of the present invention, the conjugated diene polymer may contain 80% by weight or more, 85% by weight or more, 90% by weight or more, 95% by weight or more, or 100% by weight of 1,3-butadiene monomer units, and optionally 20% by weight or less, 15% by weight or less, 10% by weight or less, or 5% by weight or less of other conjugated diene monomer units copolymerizable with the 1,3-butadiene monomer. Within this range, the reduction of the cis-1,4 bond content in the conjugated diene polymer can be prevented. The 1,3-butadiene monomer may be 1,3-butadiene or a derivative thereof, such as 1,3-butadiene, 2,3-dimethyl-1,3-butadiene or 2-ethyl-1,3-butadiene, and other conjugated diene monomer units copolymerizable with the 1,3-butadiene monomer may be 2-methyl-1,3-pentadiene, 1,3-pentadiene, 3-methyl-1,3-pentadiene, 4-methyl-1,3-pentadiene, 1,3-hexadiene or 2,4-hexadiene.

[0061] According to one embodiment of the present invention, the conjugated diene polymer may be a conjugated diene polymer catalyzed by a catalyst composition comprising a lanthanide rare earth element compound. That is, the conjugated diene polymer may be a conjugated diene polymer comprising an organometallic group activated by a catalyst composition comprising a neodymium compound.

[0062] In addition, the 1,4-cis bond content of the conjugated diene polymer is 95.0% by weight or more, 95.1% by weight or more, 95.2% by weight or more, 95.3% by weight or more, 95.4% by weight or more, 95.5% by weight or more, 95.6% by weight or more, 95.7% by weight or more, 95.8% by weight or more, 95.9% by weight or more, 96.0% by weight or more, 96.1% by weight or more, 96.2% by weight or more, 96.3% by weight or more % or more, 96.4 wt % or more, 96.5 wt % or more, 96.6 wt % or more, 96.7 wt % or more, 96.8 wt % or more, 96.9 wt % or more, 97.0 wt % or more, 97.1 wt % or more, 97.2 wt % or more, 97.3 wt % or more, 97.4 wt % or more, or 97.5 wt % or more, and may be 100.0 wt % or less, 99.5 wt % or less, or 99.0 wt % or less

[0063] In addition, the molecular weight distribution (Mw / Mn) of conjugated diene polymer can be 2.3 to 2.8, and specifically 2.4 to 2.8 or 2.5 to 2.8. Molecular weight distribution can be calculated by the ratio (Mw / Mn) of weight average molecular weight (Mw) and number average molecular weight (Mn). In this case, number average molecular weight (Mn) is the molecular weight by measuring n polymer chains, obtains the summation of molecular weight and the common mean value of the single polymer molecular weight calculated by summation divided by n, and weight average molecular weight (Mw) represents the molecular weight obtained by weighting the weight fraction of different molecular weight molecules in polymer to molecular weight. All molecular weight averages can be represented in grams per mole (g / mol). In addition, weight average molecular weight and number average molecular weight can each refer to the polystyrene conversion molecular weight analyzed by gel permeation chromatography (GPC). If above-mentioned molecular weight distribution is met, the tensile properties and viscoelastic properties of the rubber composition comprising conjugated diene polymer can have excellent balance.

[0064] According to one embodiment of the present invention, the number average molecular weight of the conjugated diene polymer can be 200000 g / mol or more and 400000 g / mol or less. Within this range, if applied to a rubber composition, the tensile properties are excellent and the processability is excellent, thereby improving the processability of the rubber composition and making it easy to knead, so that the mechanical properties and property balance of the rubber composition are excellent.

[0065] According to one embodiment of the present invention, the weight average molecular weight of the conjugated diene polymer can be 500000 g / mol or more and 800000 g / mol or less. Within this range, if applied to a rubber composition, the tensile properties are excellent and the processability is excellent, thereby improving the processability of the rubber composition, making it easy to knead, and the mechanical properties and property balance of the rubber composition are excellent.

[0066] According to one embodiment of the present invention, if the conjugated diene polymer satisfies the molecular weight distribution, weight average molecular weight (Mw) and number average molecular weight conditions at the same time, if applied to a rubber composition, the rubber composition has excellent tensile properties, viscoelasticity and processability, and the balance of properties therebetween is excellent.

[0067] In addition, the height retention (ΔH) of the conjugated diene polymer according to one embodiment of the present invention is calculated by Equation 1. @20℃ ) may be 30% or more, and specifically 35% or more, 38% or more, or 40% or more.

[0068] In addition, the height retention (ΔH) of the conjugated diene polymer was calculated by Equation 1. @20℃ ) may be 50% or less, and specifically 48% or less or 45% or less.

[0069] In addition, the height retention (ΔH) of the conjugated diene polymer according to one embodiment of the present invention is calculated by Equation 2. @40℃ ) can be 18% or more, and specifically 20% or more, 24% or more, 38% or more, or 30% or more.

[0070] In addition, the height retention (ΔH) of the conjugated diene polymer was calculated by Equation 2. @40℃ ) may be 40% or less, and specifically 38% or less or 35% or less.

[0071] [Equation 2]

[0072] ΔH @40℃ (%)=(H 8@40℃ / H 0@40℃ )×100

[0073] In Equation 2,

[0074] H 0@40℃ The initial height is measured by molding 2.5 g of a conjugated diene polymer into a cylindrical shape having a diameter of 15 mm and a height of 12 mm at 100° C. to prepare a sample, and then cooling the sample to a temperature of 40° C., and

[0075] H 8@40℃ It is the height of the sample measured after a load of 5 kg is applied to the upper surface of the sample for 8 minutes while maintaining the temperature of 40°C.

[0076] Typically, in conjugated diene polymers, branches are formed by introducing branch-containing monomers and / or modifiers into the polymer chain, or by bonding a modifier, which acts as a linker, to the polymer chain to form a structure similar to a branch. In this case, although the branched structure can improve cold flow properties and processability, the molecular weight distribution of the polymer may be significantly broadened. As a result, the excellent kneading properties of conjugated diene polymers with a linear structure, such as tensile properties and viscoelastic properties, may not be maintained, and these properties may deteriorate.

[0077] However, the conjugated diene polymer of one embodiment of the present invention contains branches, but the branches are branches (branched chains) formed only by controlling the polymerization of monomers without introducing branch-containing monomers or modifiers, so that an appropriate branched structure can be obtained without excessively expanding the molecular weight distribution.

[0078] The conjugated diene polymer according to one embodiment of the present invention can be predicted to have a molecular structure containing branches, as long as it satisfies both the above-mentioned molecular weight distribution and the height retention ratio calculated by Equation 1 and / or Equation 2. Here, the height retention ratio calculated by Equation 1 and Equation 2 can represent the low-temperature fluidity of the polymer.

[0079] Therefore, in one embodiment of the present invention, the copolymer satisfies both the above molecular weight distribution and the height retention (ΔH) calculated by Equation 1. @20℃ ), or the molecular weight distribution mentioned above, and the height retention rate (ΔH calculated by Equation 1) @20℃ ) and the height retention rate (ΔH) calculated by Eq. @40℃ ), and can have excellent physical properties in terms of tensile properties, viscoelastic properties and wear resistance of conjugated diene polymers with high linearity, while also having excellent processability properties.

[0080] In another embodiment, the β value of the conjugated diene polymer measured at 100° C. may be 0.2 or less, specifically 0.19 or less, 0.18 or less, or 0.05 or greater, 0.1 or greater, or 0.1 or greater. The β value can confirm that branches have been introduced into the conjugated diene polymer.

[0081] In another embodiment, if the conjugated diene polymer of one embodiment of the present invention is subjected to dynamic viscoelasticity analysis according to frequency change, the difference (Max-Min) between the maximum and minimum values ​​of the phase angle determined in the angular frequency range of 0.01 rad / s to 100 rad / s may be 2.3° or more, 2.35° or more, or 2.40° or more, and may be 3.5° or less, 3.30° or less, or 3.10° or less.

[0082] Furthermore, according to one embodiment of the present invention, when a dynamic viscoelasticity analysis based on frequency variation is performed on a conjugated diene polymer, the maximum value (Max) of the phase angle determined within an angular frequency range of 0.01 rad / s to 100 rad / s may be 44° or less. Specifically, the maximum value (Max) of the phase angle may be 44° or less or 43.5° or less, and may be 38° or more, 38.5° or more, or 39° or more.

[0083] In addition, if a dynamic viscoelastic analysis of a conjugated diene polymer is performed according to frequency variation, the difference between the phase angle at an angular frequency of 1 rad / s and the phase angle at 0.1 rad / s (PA@1rad / s-PA@0.1rad / s) may be +1.7° or more. Here, PA@1rad / s and PA@0.1rad / s refer to PA at 1 rad / s and PA at 0.1 rad / s, respectively. Specifically, the phase angle difference (PA@1rad / s-PA@0.1rad / s) may be +1.71° or more or +1.73° or more, and may be +3.50° or less, +3.00° or less, or +2.90° or less.

[0084] According to one embodiment of the present invention, when a frequency-dependent dynamic viscoelasticity analysis is performed on a conjugated diene polymer, the complex viscosity at an angular frequency of 0.01 rad / s may be 180,000 Pa.s or greater. Specifically, the complex viscosity may be 180,000 Pa.s to 500,000 Pa.s or 180,000 Pa.s to 300,000 Pa.s.

[0085] The difference between the maximum and minimum phase angles (Max-Min), the phase angle difference (PA@1 rad / s - PA@0.1 rad / s), and the complex viscosity vary depending on the branching and branch length in the conjugated diene polymer. As the branching and branch length increase, the difference between the maximum and minimum phase angles (Max-Min) and the phase angle difference (PA@1 rad / s - PA@0.1 rad / s) increase. Furthermore, the complex viscosity tends to increase at low angular frequencies (0.01 rad / s) and decrease at high angular frequencies (1.0 rad / s). In one embodiment of the present invention, the copolymer can improve cold fluidity and processability by satisfying the difference between the maximum and minimum values ​​of the phase angle (Max-Min), the difference between the phase angles (PA@1rad / s-PA@0.1rad / s) and the complex viscosity, and the conjugated diene polymer that satisfies the difference between the maximum and minimum values ​​of the phase angle (Max-Min), the difference between the phase angles (PA@1rad / s-PA@0.1rad / s) and the complex viscosity of one embodiment of the present invention can mean that the conjugated diene polymer contains branches with appropriate lengths in the polymer at a suitable ratio.

[0086] According to one embodiment of the present invention, the Mooney viscosity (ML1+4, @100°C) of the conjugated diene-based polymer may be 40 to 50. Here, @100°C means at 100°C.

[0087] Preparation method of conjugated diene polymer

[0088] The present invention provides a method for preparing a conjugated diene polymer. The method for preparing a conjugated diene polymer can be a method for preparing the above-mentioned conjugated diene polymer.

[0089] According to one embodiment of the present invention, the method for preparing a conjugated diene polymer may include step (100) of polymerizing a conjugated diene monomer in a hydrocarbon solvent in the presence of a catalyst composition to prepare a living polymer.

[0090] According to one embodiment of the present invention, the catalyst composition may include a lanthanide rare earth element compound, an alkylating agent, a halide, and an organic solvent. In addition, the catalyst composition may include a reaction product of a lanthanide rare earth element compound, an alkylating agent, and a halide.

[0091] According to one embodiment of the present invention, the lanthanide rare earth element compound may be a neodymium compound, and specific examples thereof include: neodymium carboxylates (e.g., neodymium acetate, neodymium acrylate, neodymium methacrylate, neodymium gluconate, neodymium citrate, neodymium fumarate, neodymium lactate, neodymium maleate, neodymium oxalate, neodymium 2-ethylhexanoate, neodymium neodecanoate, etc.); organic phosphates (e.g., neodymium dibutyl phosphate, neodymium dipentyl phosphate, neodymium diphosphate); hexyl phosphate neodymium salt, diheptyl phosphate neodymium salt, dioctyl phosphate neodymium salt, bis(1-methylheptyl) phosphate neodymium salt, di(2-ethylhexyl) phosphate neodymium salt, didecyl phosphate neodymium salt, etc.); organic phosphonate salts (for example, neodymium butylphosphonate, neodymium pentylphosphonate, neodymium hexylphosphonate, neodymium heptylphosphonate, neodymium octylphosphonate, neodymium (1-methylheptyl) phosphonate, neodymium (2-ethylhexyl) phosphonate, neodymium bis(trimethylsilyl) methylphosphonate ( ), neodymium dodecylphosphonate, neodymium octadecylphosphonate, etc.); organic phosphinate salts (such as neodymium butylphosphinate, neodymium pentylphosphinate, neodymium hexylphosphinate, neodymium heptylphosphinate, neodymium octylphosphinate, (1-methylheptyl) phosphinate, neodymium (2-ethylhexyl) phosphinate, etc.); amino acids (such as neodymium dimethylcarbamate, neodymium diethylcarbamate, neodymium diisopropylcarbamate, neodymium dibutylcarbamate, diphenylcarbamate, neodymium benzoate ... dithiocarbamates (e.g., neodymium dimethyldithioaminoacid, neodymium diethyldithioaminoacetic acid, neodymium diisopropyldithioaminobutyrate, neodymium dibutyldithioaminocarboxylate, etc.); xanthate salts (e.g., neodymium methylxanthate, neodymium ethylxanthate, neodymium isopropylxanthate, neodymium butylxanthate, neodymium benzylxanthate, etc.); β-diketonates (e.g., neodymium acetylacetonate, neodymium trifluoroacetate, neodymium trifluoroacetate, etc.); Neodymium acetonate, neodymium hexafluoroacetylacetonate and neodymium benzoylacetonate, etc.); alkoxides or allyloxides (for example, neodymium methoxide, neodymium ethoxide, neodymium isopropoxide, neodymium phenoxide, neodymium nonylphenoxide, etc.); halides or quasi-halides (neodymium fluoride, neodymium chloride, neodymium bromide, neodymium iodide, neodymium cyanide, neodymium cyanate, neodymium thiocyanate, neodymium azide, etc.); oxyhalides (such as neodymium oxyfluoride, neodymium oxychloride, neodymium oxybromide, etc.); or containing a The above rare earth element-carbon bond organic neodymium compounds (for example, Cp3Ln, Cp2LnR, Cp2LnCl, CpLnCl2, CpLn(cyclooctatetraene), (C5Me5)2LnR, LnR3, Ln(allyl)3, Ln(allyl)2Cl, wherein Ln is a rare earth metal element and R is a hydrocarbon group), and may include any one of them or a mixture of two or more thereof.

[0092] According to one embodiment of the present invention, the lanthanide rare earth element compound may be a neodymium compound represented by the following Formula 1.

[0093] [Formula 1]

[0094]

[0095] In formula 1, R 1 to R 3 are each independently hydrogen or an alkyl group having 1 to 12 carbon atoms, but R 1 to R 3 In a specific embodiment, in Formula 1, R 1 It may be an alkyl group having 4 to 12 carbon atoms, R 2 and R 3 may each independently be hydrogen or an alkyl group having 2 to 8 carbon atoms, but R 2 and R 3 In a more specific embodiment, in Formula 1, R 1 may be an alkyl group having 6 to 8 carbon atoms, and R2 and R 3 may each independently be hydrogen or an alkyl group having 2 to 6 carbon atoms, but R 2 and R 3 It may not be entirely hydrogen.

[0096] According to one embodiment of the present invention, the lanthanide rare earth element compound may be one or more selected from the group consisting of: Nd(2-ethylhexanoic acid)3 (or neodymium neodecanoate), Nd(2,2-dimethyldecanoic acid)3, Nd(2,2-diethyldecanoic acid)3, Nd(2,2-dipropyldecanoic acid)3, Nd(2,2-dibutyldecanoic acid)3, Nd(2,2-dihexyldecanoic acid)3, Nd(2,2-dioctyldecanoic acid)3, Nd(2-ethyl-2-propyldecanoic acid)3, Nd(2-ethyl-2-butyldecanoic acid)3, Nd(2-ethyl-2-hexyldecanoic acid)3, Nd(2-propyl-2-butyldecanoic acid)3, Nd(2-propyl-2-hexyl ... d(2-propyl-2-isopropyldecanoic acid)3, Nd(2-butyl-2-hexyldecanoic acid)3, Nd(2-hexyl-2-octyldecanoic acid)3, Nd(2,2-diethyloctanoic acid)3, Nd(2,2-dipropyloctanoic acid)3, Nd(2,2-dibutyloctanoic acid)3, Nd(2,2-dihexyloctanoic acid)3, Nd(2-ethyl-2-propyloctanoic acid)3, Nd(2-ethyl-2-hexyloctanoic acid)3, Nd(2,2-diethylnonanoic acid)3, Nd(2,2-dipropylnonanoic acid)3, Nd(2,2-dibutylnonanoic acid)3, Nd(2,2-dihexylnonanoic acid)3, Nd(2-ethyl-2-propylnonanoic acid)3 and Nd(2-ethyl-2-hexylnonanoic acid)3.

[0097] According to one embodiment of the present invention, a neodymium compound may contain a carboxylic acid ligand having an alkyl group of various lengths having two or more carbon atoms at the α-position. This induces stereochemical changes around the central neodymium metal to prevent entanglement between the compounds. Consequently, when the catalyst composition is used to polymerize conjugated diene polymers, oligomerization is suppressed. Furthermore, such a neodymium compound has high solubility in solvents, and the proportion of centrally located neodymium, which is difficult to convert into a catalytically active species, is reduced, resulting in a high conversion rate to the catalytically active species.

[0098] According to one embodiment of the present invention, the solubility of the neodymium compound may be about 60 parts by weight or more relative to 100 parts by weight of the non-polar solvent at room temperature (25° C.). The solubility of the neodymium compound indicates the degree to which the neodymium compound dissolves clearly without turbidity, and by exhibiting high solubility, excellent catalytic activity may be exhibited.

[0099] According to one embodiment of the present invention, the alkylating agent is an organometallic compound capable of transferring a hydrocarbon group to another metal and can act as a cocatalyst. The alkylating agent can be an organometallic compound that is soluble in the polymerization solvent and contains a metal-carbon bond, such as an organoaluminum compound, an organomagnesium compound, or an organolithium compound.

[0100] According to one embodiment of the present invention, the alkylating agent may be an organoaluminum compound, and specific examples thereof may include: alkylaluminum, such as tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-tert-butylaluminum, tripentylaluminum, trihexylaluminum, tricyclohexylaluminum, and trioctylaluminum; dihydrocarbylaluminum hydrides, such as diethylaluminum hydride, di-n-propylaluminum hydride, diisopropylaluminum hydride, di-n-butylaluminum hydride, diisobutylaluminum hydride (DIBAH), di-n-octylaluminum hydride, diphenylaluminum hydride, di-p-tolylaluminum hydride, dibenzylaluminum hydride, phenylethylaluminum hydride, phenyl-n-propylaluminum hydride, phenylisopropylaluminum hydride , phenyl-n-butylaluminum hydride, phenylisobutylaluminum hydride, phenyl-n-octylaluminum hydride, p-tolylethylaluminum hydride, p-tolyl-n-propylaluminum hydride, p-tolylisopropylaluminum hydride, p-tolyl-n-butylaluminum hydride, p-tolylisobutylaluminum hydride, p-tolyl-n-octylaluminum hydride, benzylethylaluminum hydride, benzyl-n-propylaluminum hydride, benzylisopropylaluminum hydride, benzyl-n-butylaluminum hydride, benzylisobutylaluminum hydride and benzyl-n-octylaluminum hydride; and hydrocarbylaluminum dihydrides, such as ethylaluminum dihydride, n-propylaluminum dihydride, isopropylaluminum dihydride, n-butylaluminum dihydride, isobutylaluminum dihydride and n-octylaluminum dihydride

[0101] According to one embodiment of the present invention, the alkylating agent may be an alkyl aluminum compound represented by the following Formula 2.

[0102] [Formula 2]

[0103] AYR 4 R 5 R 6

[0104] In formula 2, R 4 to R 6 are each independently hydrogen or an alkyl group having 1 to 12 carbon atoms, but R 4 to R 6 is not entirely hydrogen, and may not include tri-n-hexyl aluminum and tri-n-octyl aluminum. In a specific embodiment, in Formula 2, R 4 to R 6 may each independently be hydrogen or an alkyl group having 3 to 8 carbon atoms, but R 4 to R 6 It may not be entirely hydrogen, and may not include tri-n-hexyl aluminum and tri-n-octyl aluminum. In a more specific embodiment, in Formula 2, R 4to R 6 may each independently be hydrogen or an alkyl group having 3 to 5 carbon atoms, but R 4 to R 6 It may not be entirely hydrogen.

[0105] According to one embodiment of the present invention, the alkylating agent may comprise two or more alkylaluminum compounds. In a specific embodiment, the alkylating agent may comprise two or more selected from the group consisting of dialkylaluminum hydrides and trialkylaluminums. In a more specific embodiment, the alkylating agent may comprise one or more dialkylaluminum hydrides and one or more trialkylaluminums, and in an even more specific embodiment, the alkylating agent may comprise diisobutylaluminum hydride and triisobutylaluminum, or diisobutylaluminum hydride and triethylaluminum.

[0106] According to one embodiment of the present invention, the catalyst composition can be obtained by introducing an alkylating agent in a molar ratio of 1 mol or more, 2 mol or more, 3 mol or more, 4 mol or more, 5 mol or more, 6 mol or more, 7 mol or more, 8 mol or more, 9 mol or more, 10 mol or more, 11 mol or more, 12 mol or more, 13 mol or more, 14 mol or more or 15 mol or more relative to 1 mol of the lanthanide rare earth element compound, and can also contain the alkylating agent in a molar ratio of 200 mol or less, 150 mol or less, 80 mol or less, 60 mol or less, 50 mol or less, 40 mol or less, 30 mol or less or 25 mol or less.

[0107] According to one embodiment of the present invention, the halide may be a halogen element, an interhalide, a hydrogen halide, an organic halide, a non-metallic halide, a metal halide or an organic metal halide.

[0108] According to one embodiment of the present invention, the halogen element may be fluorine, chlorine, bromine or iodine.

[0109] According to one embodiment of the present invention, the mutual halogen compound may be iodine monochloride, iodine monobromide, iodine trichloride, iodine pentafluoride, iodine monofluoride or iodine trifluoride.

[0110] According to one embodiment of the present invention, the hydrogen halide may be hydrogen fluoride, hydrogen chloride, hydrogen bromide or hydrogen iodide.

[0111] According to one embodiment of the present invention, the organic halide can be tert-butyl chloride (t-BuCl), tert-butyl bromide, allyl chloride, allyl bromide, benzyl chloride, benzyl bromide, chlorodiphenylmethane, bromodiphenylmethane, triphenylmethyl chloride, triphenylmethyl bromide, dichlorobenzyl, dibromobenzyl, methyltrichlorosilane, phenyltrichlorosilane, dimethyldichlorosilane, diphenyldichlorosilane, trimethylchlorosilane (TMSCl), benzoyl chloride, benzoyl bromide, propionyl chloride, propionyl bromide, methyl chloroformate, methyl bromoformate, iodomethane, diiodomethane, triiodomethane (also known as methyl iodide),

[0014] The present invention also includes iodine, iodine, methyl iodide ...

[0112] According to one embodiment of the present invention, the non-metal halide can be phosphorus trichloride, phosphorus tribromide, phosphorus pentachloride, phosphorus oxychloride, phosphorus oxybromide, boron trifluoride, boron trichloride, boron tribromide, silicon tetrafluoride, silicon tetrachloride (SiCl4), silicon tetrabromide, arsenic trichloride, arsenic tribromide, selenium tetrachloride, selenium tetrabromide, tellurium tetrachloride, tellurium tetrabromide, silicon tetraiodide, arsenic triiodide, tellurium tetraiodide, boron triiodide, phosphorus triiodide, phosphorus oxyiodide or selenium tetraiodide.

[0113] According to one embodiment of the present invention, the metal halide can be tin tetrachloride, tin tetrabromide, aluminum trichloride, aluminum tribromide, antimony trichloride, antimony pentachloride, antimony tribromide, aluminum trifluoride, gallium trichloride, gallium tribromide, gallium trifluoride, indium trichloride, indium tribromide, indium trifluoride, titanium tetrachloride, titanium tetrabromide, zinc dichloride, zinc difluoride, aluminum triiodide, gallium triiodide, indium triiodide, titanium tetrachloride, zinc diiodide, gallium tetraiodide, tin diiodide, antimony triiodide or magnesium diiodide.

[0114] According to one embodiment of the present invention, the organometallic halide can be an alkylaluminum halide or an alkylaluminum sesquihalide. In a specific embodiment, the organometallic halide can be dimethylaluminum chloride, diethylaluminum chloride, dimethylaluminum bromide, diethylaluminum bromide, dimethylaluminum fluoride, diethylaluminum fluoride, methylaluminum dichloride, ethylaluminum dichloride, methylaluminum dibromide, ethylaluminum dibromide, methylaluminum difluoride, ethylaluminum difluoride, methylaluminum sesquichloride, ethylaluminum sesquichloride (EASC), isobutylaluminum sesquichloride, methylmagnesium chloride, methylmagnesium bromide, ethylmagnesium chloride, ethylmagnesium bromide, n-butylmagnesium chloride, n-butylmagnesium bromide, phenylmagnesium chloride, phenylmagnesium bromide, benzylmagnesium chloride, trimethyltin chloride, trimethyltin bromide, triethyltin chloride, triethyltin bromide, di-tert-butylmagnesium sesquichloride, Butyltin dichloride, di-tert-butyltin dibromide, di-n-butyltin dichloride, di-n-butyltin dibromide, tri-n-butyltin chloride, tri-n-butyltin bromide, methylmagnesium iodide, dimethylaluminum iodide, diethylaluminum iodide, di-n-butylaluminum iodide, diisobutylaluminum iodide, di-n-octylaluminum iodide, methylaluminum diiodide, ethylaluminum diiodide, n-butylaluminum diiodide, isobutylaluminum diiodide, methylaluminum sesquiiodide, ethylaluminum sesquiiodide, isobutylaluminum sesquiiodide, ethylmagnesium iodide, n-butylmagnesium iodide, isobutylmagnesium iodide, phenylmagnesium iodide, benzylmagnesium iodide, trimethyltin iodide, triethyltin iodide, tri-n-butyltin iodide, di-n-butyltin diiodide or di-tert-butyltin diiodide.

[0115] According to one embodiment of the present invention, from the perspective of improving catalytic activity and thus reactivity, the halide may be one or more selected from the group consisting of alkylaluminum halides represented by Formula 3 and alkylaluminum sesquihalides represented by Formula 4.

[0116] [Formula 3]

[0117] AYR 7 R 8 R 9

[0118] In formula 3, R 7 to R 9 are each independently a halogen group or an alkyl group having 1 to 12 carbon atoms, but R 7 to R 9 Not all of them may be halogen groups. In a specific embodiment, in Formula 3, R 7 to R 9 may each independently be a halogen group or an alkyl group having 1 to 6 carbon atoms, but R 7 to R 9 In a more specific embodiment, in Formula 3, R 7 and R 8may each independently be a halogen group or an alkyl group having 1 to 4 carbon atoms, and R 9 It may be a halogen group.

[0119] [Formula 4]

[0120]

[0121] In formula 4, R 10 to R 12 Each of X1 to X3 may be independently an alkyl group having 1 to 12 carbon atoms, and each of X1 to X3 may be independently a halogen group. In a specific embodiment, in Formula 4, R 10 to R 12 can each independently be an alkyl group having 1 to 6 carbon atoms. In a more specific embodiment, in Formula 4, R 10 to R 12 Each may independently be a halogen group or an alkyl group having 1 to 4 carbon atoms.

[0122] According to one embodiment of the present invention, the halide may be one or more selected from the group consisting of a dialkylaluminum halide and an alkylaluminum sesquihalide, and the types of the dialkylaluminum halide and the alkylaluminum sesquihalide are as described above. In a specific embodiment, the dialkylaluminum halide may be diethylaluminum chloride, and the alkylaluminum sesquihalide may be ethylaluminum sesquichloride.

[0123] According to one embodiment of the present invention, the catalyst composition may contain a halide at a molar ratio of 0.1 mol or more, 0.5 mol or more, 1.0 mol or more, 1.5 mol or more, 2.0 mol or more, 2.5 mol or more, or 3.0 mol or more relative to 1 mol of the lanthanide rare earth element compound. Furthermore, the halide may be contained at a molar ratio of 20 mol or less, 15 mol or less, 10 mol or less, 8 mol or less, 6 mol or less, or 5 mol or less relative to 1 mol of the lanthanide rare earth element compound.

[0124] According to one embodiment of the present invention, the catalyst composition may contain an organic solvent. The organic solvent may be a non-polar solvent that does not react with the constituent components of the catalyst composition. In a specific embodiment, the organic solvent may be a straight-chain, branched or cyclic aliphatic hydrocarbon having 5 to 20 carbon atoms, such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, isopentane, isohexane, isoheptane, isooctane, 2,2-dimethylbutane, cyclopentane, cyclohexane, methylcyclopentane and methylcyclohexane; a mixed solvent of aliphatic hydrocarbons having 5 to 20 carbon atoms, such as petroleum ether, petroleum spirit and kerosene; or an aromatic hydrocarbon solvent, such as benzene, toluene, ethylbenzene and xylene. In a more specific embodiment, the organic solvent may be a straight-chain, branched or cyclic aliphatic hydrocarbon or a mixed solvent of aliphatic hydrocarbons having 5 to 20 carbon atoms, preferably n-hexane, cyclohexane or a mixture thereof.

[0125] Meanwhile, according to one embodiment of the present invention, the catalyst composition can be prepared by stirring a lanthanide rare earth element compound and a first alkylating agent in an organic solvent for pre-activation, adding a second alkylating agent thereto and stirring for alkylation, and then adding a halide for halogenation. Here, the first alkylating agent can be one or more selected from the above-mentioned trialkylaluminums, and the second alkylating agent can be one or more selected from the above-mentioned dialkylaluminum hydrides. Pre-activation can be carried out by stirring at a temperature of 0°C to 40°C, alkylation can be carried out by stirring at a temperature of -10°C to 30°C, and halogenation can be carried out by stirring at a temperature of -20°C to 20°C.

[0126] When the catalyst composition is prepared under such conditions, the catalytic activity can be maximized, and in the case of polymerizing conjugated diene monomers, the polymerization of the monomers can proceed faster, thereby increasing the reaction between polymer chains, which can be beneficial to the ultimate preparation of a conjugated diene polymer having appropriately introduced branches.

[0127] According to one embodiment of the present invention, the conjugated diene monomer introduced in step (S100) may be one or more selected from the group consisting of 1,3-butadiene, isoprene, 1,3-pentadiene, 1,3-hexadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, 3-methyl-1,3-pentadiene, 4-methyl-1,3-pentadiene and 2,4-hexadiene.

[0128] According to one embodiment of the present invention, the hydrocarbon solvent in step (S100) can be one or more selected from the group consisting of n-pentane, n-hexane, n-heptane, isooctane, cyclohexane, toluene, benzene and xylene.

[0129] According to one embodiment of the present invention, the amount of the catalyst composition used can be such that the neodymium compound is greater than 0.03 mmol, greater than 0.04 mmol, greater than 0.05 mmol or greater than 0.06 mmol relative to a total of 100 g of conjugated diene monomers, and the amount used can also be such that the neodymium compound is less than 0.15 mmol, less than 0.14 mmol, less than 0.13 mmol, less than 0.12 mmol, less than 0.11 mmol, less than 0.10 mmol, less than 0.09 mmol or less than 0.08 mmol.

[0130] According to one embodiment of the present invention, the polymerization in step (S100) can be carried out as continuous polymerization in a polymerization reactor comprising at least two reactors, or can be carried out in a batch reactor. In addition, the polymerization can be a temperature-raising polymerization, an isothermal polymerization or a constant temperature polymerization (adiabatic polymerization).

[0131] According to one embodiment of the present invention, isothermal polymerization refers to polymerization by the heat of the reaction itself without arbitrarily applying heat after the introduction of the catalyst composition, temperature-increasing polymerization refers to increasing the temperature by arbitrarily applying heat after the introduction of the catalyst composition, and isothermal polymerization refers to increasing heat or removing heat by applying heat after the introduction of the catalyst composition to keep the temperature of the reactants constant.

[0132] According to one embodiment of the present invention, the polymerization in step (S100) can be performed using coordinated anionic polymerization, and the polymerization environment can be bulk polymerization, solution polymerization, suspension polymerization or emulsion polymerization, and a specific embodiment can be solution polymerization.

[0133] According to one embodiment of the present invention, the polymerization in step (S100) can be carried out at a temperature of above -20°C, above -10°C, above 0°C, above 10°C, above 20°C, above 30°C, above 40°C, above 50°C or above 60°C, and can be carried out at a temperature below 200°C, below 150°C, below 120°C or below 90°C, and within this range, the polymerization reaction can be smoothly controlled while ensuring the cis-1,4 bond content of the produced conjugated diene polymer.

[0134] According to one embodiment of the present invention, the polymerization in step (S100) can be carried out for more than 15 minutes, more than 20 minutes, more than 30 minutes, more than 40 minutes, more than 50 minutes or more than 1 hour, and can be carried out for less than 3 hours, less than 2 hours and 30 minutes or less than 2 hours.

[0135] As another embodiment, according to one embodiment of the present invention, the polymerization in step (S100) can be carried out as a continuous polymerization using a continuous reactor having 2 or more, 2 to 10 or 2 to 5 or 2 to 4 reactors connected in series, and in this case, it can be more advantageous to produce a conjugated diene polymer having the above-mentioned characteristics and having introduced side chains.

[0136] In addition, according to one embodiment of the present invention, the polymerization in step (S100) can be carried out for more than 60 minutes, more than 70 minutes, more than 80 minutes, more than 90 minutes, or less than 180 minutes, less than 150 minutes or less than 120 minutes, and in this case, it can be more conducive to the production of a conjugated diene polymer having the above-mentioned characteristics and having introduced side chains.

[0137] In addition, according to one embodiment of the present invention, the polymerization in step (S100) can be carried out by dividing the conjugated diene monomer into two or more parts, and when the conjugated diene monomer is divided into two or more parts, the amount of the conjugated diene monomer added after the second part can be 20 to 40 parts by weight or 25 to 35 parts by weight relative to 100 parts by weight of the total conjugated diene monomer added during the polymerization. In addition, when the conjugated diene monomer is divided into three or more parts, the amount of the conjugated diene monomer added in the second, third, ... and nth parts can be added by appropriately allocating the amount of the conjugated diene monomer added after the second part.

[0138] Furthermore, if the conjugated diene monomer is introduced separately, the conjugated diene monomer introduced after the initial stage can be introduced at a time point when the polymerization conversion rate of the initially introduced conjugated diene monomer is 50% or more, 60% or more, or 70% or more and 90% or less, 85% or less, or 80% or less.

[0139] According to one embodiment of the present invention, the conjugated diene-based polymer formed by the polymerization in step ( S100 ) may be a living polymer including sites activated by the catalyst composition.

[0140] According to one embodiment of the present invention, a step of reacting the living polymer with a modifier ( S200 ) may be included. The modifier may be a known modifier that can be used when producing a conjugated diene polymer using a catalyst composition containing a lanthanide rare earth element compound.

[0141] According to one embodiment of the present invention, the method for producing a conjugated diene polymer may include a step of further using an additive to terminate the polymerization reaction after producing the active polymer. The additive may include, for example, a reaction terminator for completing the polymerization reaction, such as polyoxyethylene glycol phosphate; or an antioxidant, such as 2,6-di-tert-butyl-p-cresol. In addition to the reaction terminator, an additive that promotes solution polymerization, such as a chelating agent, a dispersant, a pH adjuster, an antioxidant, or an oxygen scavenger, may optionally be further used.

[0142] The method for producing a conjugated diene polymer according to one embodiment of the present invention can be carried out by appropriately selecting and combining conditions in the above method, so that a conjugated diene polymer meeting the above parameters can be produced. Specifically, the method can be carried out by appropriately selecting and controlling catalyst composition production conditions, such as the preactivation step, polymerization time, monomer distribution, reactor temperature, and catalyst addition amount, so that a conjugated diene polymer meeting the above parameters can be produced.

[0143] Rubber composition

[0144] The present invention provides a rubber composition.

[0145] According to one embodiment of the present invention, the rubber composition may include a conjugated diene polymer. In specific embodiments, the content of the conjugated diene polymer in the rubber composition may be 0.1% by weight or more, 10% by weight or more, or 20% by weight or more, and the content of the conjugated diene polymer may also be 100% by weight or less, 95% by weight or less, or 90% by weight or less. Within this range, the wear resistance and crack resistance of a molded product (e.g., a tire) manufactured using the rubber composition can be fully ensured.

[0146] According to one embodiment of the present invention, in addition to the conjugated diene polymer, the rubber composition may further include other rubber components as needed. In this case, the content of the rubber component may be 90% by weight or less relative to the total weight of the rubber composition. Specifically, the content of the rubber component may be 1 to 900% by weight relative to 100% by weight of the conjugated diene polymer.

[0147] According to one embodiment of the present invention, the rubber component may be a natural rubber or a synthetic rubber, and for example, the rubber component may be a natural rubber (NR) containing cis-1,4-polyisoprene; a modified natural rubber modified or purified from conventional natural rubber, such as epoxidized natural rubber (ENR), deproteinized natural rubber (DPNR) and hydrogenated natural rubber; or a synthetic rubber, such as styrene-butadiene copolymer (SBR), polybutadiene (BR), polyisoprene (IR), butyl rubber (IIR), ethylene-propylene copolymer, polyisobutylene-co-isoprene, chloroprene rubber, poly(ethylene-co-propylene), poly(styrene-co-butadiene), poly(styrene-co-isoprene), poly(styrene-co-isoprene-co-butadiene), poly(isoprene-co-butadiene), poly(ethylene-co-propylene-co-diene), polysulfide rubber, acrylate rubber, polyurethane rubber, silicone rubber, epichlorohydrin rubber, halogenated butyl rubber, and any one of them or a mixture of two or more of them may be used.

[0148] According to one embodiment of the present invention, for the rubber composition, the difference between the Mooney viscosity (ML1+4@100°C) of the conjugated diene polymer and the Mooney viscosity (ML1+4@100°C) of the rubber composition may be 30 or less. In a specific embodiment, for the rubber composition, the difference between the Mooney viscosity (ML1+4@100°C) of the conjugated diene polymer and the Mooney viscosity (ML1+4@100°C) of the rubber composition may be 30 or less, 29 or less, 28 or less, 27 or less, 26 or less, 25 or less, 24 or less, 23 or less, 22 or less, 21 or less, or 20 or less. In addition, the lower limit is not particularly limited, but may be 1 or more, 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 11 or more, 12 or more, 13 or more, 14 or more, or 15 or more. Therefore, if the difference between the Mooney viscosity (ML1+4@100° C.) of the conjugated diene-based polymer and the Mooney viscosity (ML1+4@100° C.) of the rubber composition is adjusted within the above range, processability can be particularly improved.

[0149] According to one embodiment of the present invention, the Mooney viscosity (ML1+4@100°C) of the rubber composition may be 50 or more, and may be 100 or less. In a specific embodiment, the Mooney viscosity (ML1+4@100°C) of the rubber composition may be 50 or more, 51 or more, 52 or more, 53 or more, 54 or more, 55 or more, 56 or more, 57 or more, 58 or more, 59 or more, 60 or more, or 61 or more, and may be 100 or less, 99 or less, 98 or less, 97 or less, 96 or less, 95 or less, 94 or less, 93 or less, 92 or less, 91 or less, 90 or less, 89 or less, 88 or less, 87 or less, 86 or less, 85 or less, or 84 or less. The Mooney viscosity of the rubber composition may vary depending on other components further contained in the rubber composition in addition to the conjugated diene polymer, but if it is controlled within the above range, processability can be particularly improved.

[0150] According to one embodiment of the present invention, the rubber composition may include 20 parts by weight or more and 90 parts by weight or less of a filler relative to 100 parts by weight of the conjugated diene polymer. The filler may be a silica filler, a carbon black filler, or a combination thereof. In a specific embodiment, the filler may be a carbon black filler.

[0151] According to one embodiment of the present invention, the nitrogen adsorption specific surface area (N2SA, measured in accordance with JIS K6217-2:2001) of the carbon black filler can be 20 m 2 / g to 250m 2 / g, and within this range, the rubber composition can have excellent processability while fully ensuring the reinforcing performance of the filler. In addition, the dibutyl phthalate absorption (DBP) of the carbon black filler can be 80cc / 100g to 200cc / 100g, and within this range, the rubber composition can have excellent processability while fully ensuring the reinforcing performance of the filler.

[0152] According to one embodiment of the present invention, the silica filler can be wet-process silica (hydrated silicic acid), dry-process silica (anhydrous silicic acid), calcium silicate, aluminum silicate or colloidal silica. In a specific embodiment, the silica filler can be wet-process silica, which has the best effect of improving fracture characteristics and achieving wet grip properties. In addition, the nitrogen adsorption specific surface area (N2SA) of the silica filler can be 120m 2 / g to 180m 2 / g, and the adsorption surface area of ​​cetyltrimethylammonium bromide (CTAB) can be 100m 2 / g to 200m 2 / g, and within this range, the rubber composition can have excellent processability while sufficiently ensuring reinforcing performance by the filler.

[0153] According to one embodiment of the present invention, if a silica-based filler is used as a filler, a silane coupling agent can be used together to improve the reinforcing properties and low heat generation properties. The silane coupling agent can be bis(3-triethoxysilylpropyl)tetrasulfide, bis(3-triethoxysilylpropyl)trisulfide, bis(3-triethoxysilylpropyl)disulfide, bis(2-triethoxysilylethyl)tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(2-trimethoxysilylethyl)tetrasulfide, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, 3-trimethoxysilylpropyl-N,N-dimethylthiocarbamoyltetrasulfide, 3-triethoxysilylpropyl- N,N-dimethylthiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-N,N-dimethylthiocarbamoyl tetrasulfide, 3-trimethoxysilylpropylbenzothiazolyl tetrasulfide, 3-triethoxysilylpropylbenzoyl tetrasulfide, 3-triethoxysilylpropyl methacrylate monosulfide, 3-trimethoxysilylpropyl methacrylate monosulfide, bis(3-diethoxymethylsilylpropyl)tetrasulfide, 3-mercaptopropyldimethoxymethylsilane, dimethoxymethylsilylpropyl-N,N-dimethylthiocarbamoyl tetrasulfide or dimethoxymethylsilylpropylbenzothiazolyl tetrasulfide. In a specific embodiment, considering the reinforcing property improvement effect, the silane coupling agent may be bis(3-triethoxysilylpropyl)polysulfide or 3-trimethoxysilylpropylbenzothiazolyl tetrasulfide.

[0154] According to one embodiment of the present invention, the rubber composition may be sulfur-crosslinkable and may further include a vulcanizing agent. The vulcanizing agent may specifically be sulfur powder, and its content may be 0.1 to 10 parts by weight relative to 100 parts by weight of the rubber component. Within this range, the desired elastic modulus and strength of the vulcanized rubber composition can be ensured, while low fuel consumption can be ensured.

[0155] According to one embodiment of the present invention, in addition to the above components, the rubber composition may further comprise various additives commonly used in the rubber industry, specifically vulcanization accelerators, processing oils, plasticizers, anti-aging agents, scorch inhibitors, zinc white, stearic acid, thermosetting resins or thermoplastic resins.

[0156] According to one embodiment of the present invention, the vulcanization accelerator is not particularly limited, and specifically, a thiazole compound such as M (2-mercaptobenzothiazole), DM (dibenzothiazolyl disulfide), CZ (N-cyclohexyl-2-benzothiazolesulfonamide), or a guanidine compound such as DPG (diphenylguanidine) can be used. The content of the vulcanization accelerator can be 0.1 to 5 parts by weight relative to 100 parts by weight of the rubber component.

[0157] According to one embodiment of the present invention, the process oil acts as a softener in the rubber composition, and specific examples thereof include paraffinic, cycloparaffinic, or aromatic compounds. More specifically, if tensile strength and wear resistance are considered, aromatic process oils can be used, while if hysteresis loss and low-temperature properties are considered, cycloparaffinic or paraffinic process oils can be used. The content of the process oil may be 100 parts by weight or less relative to 100 parts by weight of the rubber component, and within this range, deterioration of the tensile strength of the vulcanized rubber and low heat generation (low fuel consumption) can be prevented.

[0158] According to one embodiment of the present invention, the anti-aging agent may be N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline, or a high-temperature condensate of diphenylamine and acetone. The amount of the anti-aging agent used may be 0.1 to 6 parts by weight relative to 100 parts by weight of the rubber component.

[0159] According to one embodiment of the present invention, the rubber composition can be obtained by mixing according to the above mixing formula using a mixer such as a Banbury mixer, a roll mixer or an internal mixer, and a rubber composition with low heat generation and excellent wear resistance can be obtained by a vulcanization process after the molding process.

[0160] According to one embodiment of the present invention, the rubber composition can be used to manufacture various components of a tire, such as a tire tread, a tire bottom, a sidewall, a carcass coating rubber, a belt coating rubber, a bead filler, a bead chafer or a bead coating rubber, or various industrial rubber products, such as shock-absorbing rubber, a conveyor belt or a hose. In a specific embodiment, the molded product manufactured using the rubber composition can include a tire or a tire tread.

[0161] Hereinafter, the embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, the present invention can be implemented in various forms and is not limited to the embodiments described herein.

[0162] Preparation Example 1

[0163] In a hexane solvent, NdV (neodymium neodecanoate, Nd(2-ethylhexanoate)3) and tri-n-octylaluminum (TNOA) were added and stirred at 0°C for 30 minutes for activation, diisobutylaluminum hydride (DIBAH) was added and stirred at 10°C for 30 minutes for alkylation, and then diethylaluminum chloride (DEAC) was added and stirred at -5°C for 30 minutes to prepare a catalyst composition (molar ratio of NdV:TNOA:DIBAH:DEAC = 1:10:15:3).

[0164] Preparation Example 2

[0165] In a hexane solvent, NdV (neodymium neodecanoate, Nd(2-ethylhexanoate)3) and tri-n-octylaluminum (TNOA) were added and stirred at 0°C for 30 minutes for activation, triisobutylaluminum (TIBA) was added and stirred at 10°C for 30 minutes for alkylation, and then diethylaluminum chloride (DEAC) was added and stirred at -5°C for 30 minutes to prepare a catalyst composition (molar ratio of NdV:TNOA:TIBA:DEAC = 1:20:30:3).

[0166] Preparation Example 3

[0167] In a hexane solvent, NdV (neodymium neodecanoate, Nd(2-ethylhexanoate)3) and triethylaluminum (TEAL) were added and stirred at 0°C for 30 minutes for activation, diisobutylaluminum hydride (DIBAH) was added and stirred at 10°C for 30 minutes for alkylation, and then diethylaluminum chloride (DEAC) was added and stirred at -5°C for 30 minutes to prepare a catalyst composition (molar ratio of NdV:TEAL:DIBAH:DEAC=1:4:15:3).

[0168] Preparation Example 4

[0169] In a hexane solvent, NdV (neodymium neodecanoate, Nd(2-ethylhexanoate)3) and triethylaluminum (TEAL) were added and stirred at 0°C for 30 minutes for activation, diisobutylaluminum hydride (DIBAH) was added and stirred at 10°C for 30 minutes for alkylation, and then diethylaluminum chloride (DEAC) was added and stirred at -5°C for 30 minutes to prepare a catalyst composition (molar ratio of NdV:TEAL:DIBAH:DEAC=1:2:15:3).

[0170] Preparation Example 5

[0171] In a hexane solvent, NdV (neodymium neodecanoate, Nd(2-ethylhexanoate)3) and triethylaluminum (TEAL) were added and stirred at 0°C for 30 minutes for activation, diisobutylaluminum hydride (DIBAH) was added and stirred at 10°C for 30 minutes for alkylation, and then ethylaluminum sesquichloride (EASC) was added and stirred at -5°C for 30 minutes to prepare a catalyst composition (molar ratio of NdV:TEAL:DIBAH:EASC=1:2:15:1).

[0172] Comparative Preparation Example 1

[0173] In a hexane solvent, NdV (neodymium neodecanoate, Nd(2-ethylhexanoate)3) and diisobutylaluminum hydride (DIBAH) were added and stirred at 10°C for 30 minutes for alkylation, and then diethylaluminum chloride (DEAC) was added and stirred at -5°C for 30 minutes to prepare a catalyst composition (molar ratio of NdV:DIBAH:DEAC = 1:15:3).

[0174] Comparative Preparation Example 2

[0175] In a hexane solvent, NdV (neodymium neodecanoate, Nd(2-ethylhexanoate)3) and triisobutylaluminum (TIBA) were added and stirred at 10°C for 30 minutes to carry out alkylation, and then diethylaluminum chloride (DEAC) was added and stirred at -5°C for 30 minutes to prepare a catalyst composition (NdV:TIBA:DEAC=1:30:3 molar ratio).

[0176] Examples and Comparative Examples

[0177] Example 1

[0178] The conjugated diene polymer was prepared using a polymerization reactor consisting of two 80 L stainless steel reactors equipped with stirrers and jackets connected in series.

[0179] While maintaining the first reactor at 80°C, 35 kg / hour of hexane, 7 kg / hour of 1,3-butadiene, and the catalyst composition prepared in Preparation Example 1 (calculated as NdV in the catalyst composition, 0.05 mmol NdV / 100 g of 1,3-butadiene) were introduced through the upper portion of the first reactor, and polymerization was carried out for 90 minutes. At a point where the polymerization conversion rate was 80% or higher, the product was transferred to a second reactor maintained at 80°C, and then polymerization was carried out for an additional 15 minutes. Thereafter, the reaction was terminated by adding a hexane solution containing 1.0 g of a polymerization terminator and a hexane solution containing 2.0 g of an antioxidant, the solvent was removed by steam stripping, and the polymerized product was dried using a hot roller to produce a conjugated diene polymer.

[0180] Example 2

[0181] The conjugated diene polymer was prepared using a polymerization reactor consisting of two 80 L stainless steel reactors equipped with stirrers and jackets connected in series.

[0182] While maintaining the first reactor at 85 ° C, 35 kg / hour of hexane, 7 kg / hour of 1,3-butadiene and the catalyst composition prepared in Preparation Example 2 (0.08 mmol / 100 g of 1,3-butadiene, based on NdV in the catalyst composition) were introduced through the upper part of the first reactor, and polymerization was carried out for 110 minutes. At a point where the polymerization conversion rate was 80% or more, the product was transferred to a second reactor maintained at 85 ° C and polymerization was carried out for an additional 15 minutes. Thereafter, the reaction was terminated by adding a hexane solution containing 1.0 g of a polymerization terminator and a hexane solution containing 2.0 g of an antioxidant, the solvent was removed by steam stripping, and the polymerized product was dried using a hot roller to prepare a conjugated diene polymer.

[0183] Example 3

[0184] A conjugated diene-based polymer was prepared in the same manner as in Example 1, except that the catalyst composition prepared in Preparation Example 3 (0.04 mmol / 100 g of 1,3-butadiene based on NdV in the catalyst composition) was used instead of the catalyst composition in Example 1.

[0185] Example 4

[0186] The conjugated diene polymer was prepared using a polymerization reactor consisting of two 80 L stainless steel reactors equipped with stirrers and jackets connected in series.

[0187] While maintaining the temperature of the first reactor at 85°C, 35 kg / hour of hexane, 7 kg / hour of 1,3-butadiene, and the catalyst composition prepared in Preparation Example 3 (0.11 mmol / 100 g of 1,3-butadiene based on the NdV in the catalyst composition) were introduced through the upper portion of the first reactor, and polymerization was carried out for 110 minutes. At a point where the polymerization conversion rate was 80% or higher, the product was transferred to a second reactor maintained at 85°C. In this case, an additional 7 kg / hour of 1,3-butadiene was introduced into the second reactor, and polymerization was carried out for an additional 15 minutes. At the same time, 70% of the total amount of 1,3-butadiene used in the polymer was introduced into the first reactor, and the remaining 30% was introduced into the second reactor, and the catalyst composition was based on the total amount of 1,3-butadiene used in the polymer. Thereafter, the reaction was terminated by adding a hexane solution containing 1.0 g of a polymerization terminator and a hexane solution containing 2.0 g of an antioxidant, the solvent was removed by steam stripping, and the polymerized product was dried using a hot roll to prepare a conjugated diene-based polymer.

[0188] Example 5

[0189] The conjugated diene polymer was prepared using a polymerization reactor consisting of two 80 L stainless steel reactors equipped with stirrers and jackets connected in series.

[0190] While maintaining the first reactor at 80°C, 35 kg / hour of hexane, 7 kg / hour of 1,3-butadiene, and the catalyst composition prepared in Preparation Example 4 (0.05 mmol / 100 g of 1,3-butadiene, based on NdV in the catalyst composition) were introduced through the upper portion of the first reactor, and polymerization was carried out for 60 minutes. At a point where the polymerization conversion rate was 80% or higher, the product was transferred to a second reactor maintained at 90°C, and polymerization was carried out for an additional 15 minutes. Thereafter, the reaction was terminated by adding a hexane solution containing 1.0 g of a polymerization terminator and a hexane solution containing 2.0 g of an antioxidant, the solvent was removed by steam stripping, and the polymerized product was dried using a hot roller to prepare a conjugated diene polymer.

[0191] Example 6

[0192] The conjugated diene polymer was prepared using a polymerization reactor consisting of two 80 L stainless steel reactors equipped with stirrers and jackets connected in series.

[0193] While maintaining the temperature of the first reactor at 75°C, 35 kg / hour of hexane, 7 kg / hour of 1,3-butadiene, and the catalyst composition prepared in Preparation Example 5 (0.12 mmol / 100 g of 1,3-butadiene based on the NdV in the catalyst composition) were introduced through the upper portion of the first reactor, and polymerization was carried out for 110 minutes. At a point where the polymerization conversion rate was 80% or higher, the product was transferred to a second reactor maintained at 80°C. In this case, an additional 7 kg / hour of 1,3-butadiene was introduced into the second reactor, and polymerization was carried out for an additional 15 minutes. At the same time, 70% of the total amount of 1,3-butadiene used in the polymer was introduced into the first reactor, and the remaining 30% was introduced into the second reactor, and the catalyst composition was based on the total amount of 1,3-butadiene used in the polymer. Thereafter, the reaction was terminated by adding a hexane solution containing 1.0 g of a polymerization terminator and a hexane solution containing 2.0 g of an antioxidant, the solvent was removed by steam stripping, and the polymerized product was dried using a hot roll to prepare a conjugated diene-based polymer.

[0194] Comparative Example 1

[0195] The conjugated diene polymer was prepared using a polymerization reactor consisting of two 80 L stainless steel reactors equipped with stirrers and jackets connected in series.

[0196] While maintaining the first reactor at 80°C, 35 kg / hour of hexane, 7 kg / hour of 1,3-butadiene, and the catalyst composition prepared in Comparative Preparation Example 1 (0.05 mmol / 100 g of 1,3-butadiene, based on NdV in the catalyst composition) were introduced through the upper portion of the first reactor, and polymerization was carried out for 60 minutes. At a point where the polymerization conversion rate was 80% or higher, the product was transferred to a second reactor maintained at 80°C, and polymerization was carried out for an additional 15 minutes. Thereafter, the reaction was terminated by adding a hexane solution containing 1.0 g of a polymerization terminator and a hexane solution containing 2.0 g of an antioxidant, the solvent was removed by steam stripping, and the polymerized product was dried using a hot roller to prepare a conjugated diene polymer.

[0197] Comparative Example 2

[0198] The conjugated diene polymer was prepared using a polymerization reactor consisting of two 80 L stainless steel reactors equipped with stirrers and jackets connected in series.

[0199] While maintaining the first reactor at 80°C, 35 kg / hour of hexane, 7 kg / hour of 1,3-butadiene, and the catalyst composition prepared in Comparative Preparation Example 2 (0.07 mmol / 100 g of 1,3-butadiene, based on NdV in the catalyst composition) were introduced through the upper portion of the first reactor, and polymerization was carried out for 60 minutes. At a point where the polymerization conversion was 80% or higher, the product was transferred to a second reactor maintained at 80°C, and polymerization was carried out for an additional 15 minutes. Thereafter, the reaction was terminated by adding a hexane solution containing 1.0 g of a polymerization terminator and a hexane solution containing 2.0 g of an antioxidant, the solvent was removed by steam stripping, and the polymerized product was dried using a hot roller to prepare a conjugated diene polymer.

[0200] Comparative Example 3

[0201] The conjugated diene polymer was prepared using a polymerization reactor consisting of two 80 L stainless steel reactors equipped with stirrers and jackets connected in series.

[0202] While maintaining the first reactor at 85°C, 35 kg / hour of hexane, 7 kg / hour of 1,3-butadiene, and the catalyst composition prepared in Comparative Preparation Example 1 (0.064 mmol / 100 g of 1,3-butadiene, based on NdV in the catalyst composition) were introduced through the upper portion of the first reactor, and polymerization was carried out for 110 minutes. At a point where the polymerization conversion was 80% or higher, the product was transferred to a second reactor maintained at 90°C and polymerization was carried out for an additional 15 minutes. Thereafter, the reaction was terminated by adding a hexane solution containing 1.0 g of a polymerization terminator and a hexane solution containing 2.0 g of an antioxidant, the solvent was removed by steam stripping, and the polymerized product was dried using a hot roller to prepare a conjugated diene polymer.

[0203] Comparative Example 4

[0204] The conjugated diene polymer was prepared using a polymerization reactor consisting of two 80 L stainless steel reactors equipped with stirrers and jackets connected in series.

[0205] While maintaining the first reactor at 70 ° C, 35 kg / hour of hexane, 7 kg / hour of 1,3-butadiene and the catalyst composition prepared in Preparation Example 4 (0.044 mmol / 100 g of 1,3-butadiene, based on NdV in the catalyst composition) were introduced through the upper part of the first reactor, and polymerization was carried out for 60 minutes. At a point where the polymerization conversion rate was 80% or more, the product was transferred to a second reactor maintained at 75 ° C and polymerization was carried out for an additional 15 minutes. Thereafter, the reaction was terminated by adding a hexane solution containing 1.0 g of a polymerization terminator and a hexane solution containing 2.0 g of an antioxidant, the solvent was removed by steam stripping, and the polymerized product was dried using a hot roller to prepare a conjugated diene polymer.

[0206] Comparative Example 5

[0207] The conjugated diene polymer was prepared using a polymerization reactor consisting of two 80 L stainless steel reactors equipped with stirrers and jackets connected in series.

[0208] While maintaining the first reactor at 75°C, 35 kg / hour of hexane, 7 kg / hour of 1,3-butadiene, and the catalyst composition prepared in Preparation Example 5 (0.06 mmol / 100 g of 1,3-butadiene, based on NdV in the catalyst composition) were introduced through the upper portion of the first reactor, and polymerization was carried out for 60 minutes. At a point where the polymerization conversion was 80% or higher, the product was transferred to a second reactor maintained at 80°C and polymerization was carried out for an additional 15 minutes. Thereafter, the reaction was terminated by adding a hexane solution containing 1.0 g of a polymerization terminator and a hexane solution containing 2.0 g of an antioxidant, the solvent was removed by steam stripping, and the polymerized product was dried using a hot roller to prepare a conjugated diene polymer.

[0209] Experimental example

[0210] Experimental Example 1

[0211] For the conjugated diene-based polymers prepared in Examples 1 to 6 and Comparative Examples 1 to 5, Mooney viscosity, molecular weight distribution, cis-1,4 bond content, β value, and height retention according to Formula 1 and Formula 2 were analyzed in the following manner, and the results are shown in Table 1 below.

[0212] *Mooney viscosity (ML1+4, @100°C): For each polymer, Mooney viscosity was measured using a large rotor of a Monsanto MV2000E at 100°C and a rotor speed of 2±0.02 rpm. The sample used in this case was allowed to stand at room temperature (23±3°C) for 30 minutes or more, 27±3 g was collected and filled into a mold cavity, and the Mooney viscosity was measured while operating the platen and applying torque.

[0213] *Molecular weight distribution (MWD): The weight average molecular weight and number average molecular weight of each polymer were measured, and the molecular weight distribution was calculated from them. The molecular weight of each polymer was measured by dissolving each polymer in tetrahydrofuran (THF) at 40°C for 30 minutes, injecting it into a gel permeation chromatograph (GPC) and allowing it to flow. In this case, two PLgel Olexis columns and a PLgel mixed-C column from Polymer Laboratories were used in combination. In addition, all newly replaced columns were mixed bed columns, and polystyrene was used as a gel permeation chromatography standard material (GPC standard material).

[0214] *1,4-cis bond content (wt%): The cis-1,4 bond content of the conjugated diene portion was measured by Fourier transform infrared spectroscopy (FT-IR). Specifically, a carbon disulfide solution of a conjugated diene polymer prepared at a concentration of 5 mg / mL was measured using carbon disulfide in the same measurement cell as a blank control, and the FT-IR transmission spectrum was then measured using the 1130 cm-1 wavelength of the measured spectrum. -1 The largest peak near (a, baseline), 967 cm indicating trans-1,4 bond -1 The smallest peak near (b), 911 cm indicating vinyl bond -1 The minimum peak near (c) and 736 cm indicating cis-1,4 bond -1 The content is obtained near the minimum peak (d).

[0215] *β value (Beta-value): Tan δ was measured using Montech's D-RPA 3000 (Rubber Processing Analyzer) in a frequency sweep range of 0 to 100 Hz, a static strain of 3%, a dynamic strain of 0.25%, and a measurement temperature of 100° C., and the slope of d(log(tan δ)) / d(log(freq)) was expressed as the β value.

[0216] *Height retention rate (ΔH @20℃ , %): 2.5 g of each conjugated diene-based polymer was molded into a cylindrical shape with a diameter of 15 mm and a height of 12 mm at 100° C. to prepare a sample, and then the sample was cooled to a temperature of 20° C. to measure the initial height (H 0@20℃ While maintaining the temperature at 20°C, a load of 5 kg was applied to the upper surface of the sample, and the sample height (H 8@20℃ ), and the height retention rate was calculated using the following equation 1.

[0217] [Equation 1]

[0218] ΔH @20℃ (%)=(H 8@20℃ / H 0@20℃ )×100

[0219] *Height retention rate (ΔH @40℃ , %): 2.5 g of each conjugated diene polymer was molded into a cylindrical shape with a diameter of 15 mm and a height of 12 mm at 100° C. to prepare a sample, and then the sample was cooled to a temperature of 40° C. to measure the initial height (H 0@40℃ While maintaining the temperature at 40°C, a load of 5 kg was applied to the upper surface of the sample, and the sample height (H 8@40℃ ), and calculated using the following equation 2.

[0220] [Equation 2]

[0221] ΔH @40℃ (%)=(H 8@40℃ / H 0@40℃ )×100

[0222] [Table 1]

[0223]

[0224] According to Table 1 above, it was confirmed that the molecular weight distribution of the conjugated diene polymers of Examples 1 to 6 was 2.3 to 2.8, and the height retention (ΔH @20℃ ) is 30% or more, and the height retention rate (ΔH @40℃ ) is 18% or more, and the β value is 0.2 or less, satisfying the properties required by the present invention.

[0225] Experimental Example 2

[0226] Rubber compositions and rubber specimens were prepared using the conjugated diene polymers prepared in Examples 1 to 6 and Comparative Examples 1 to 5, and the Mooney viscosity, tensile properties, viscoelastic properties, and wear resistance of the rubber compositions were measured using the following methods. The results are shown in Table 2 below.

[0227] <Preparation of Rubber Composition and Rubber Sample>

[0228] Each rubber composition was prepared by mixing 100 parts by weight of each conjugated diene-based polymer of Examples 1 to 6 and Comparative Examples 1 to 5 with 60 parts by weight of carbon black, 15 parts by weight of processing oil (TDAE oil), 3 parts by weight of zinc oxide (ZnO), and 2 parts by weight of stearic acid.

[0229] Thereafter, 1.5 parts by weight of sulfur and 0.9 parts by weight of a vulcanization accelerator (TBBS) were added to each rubber composition, gently mixed at 50° C. at 50 rpm for 2 minutes, and then a sheet-shaped vulcanized mixture was obtained using a roller at 50° C. The obtained vulcanized mixture was vulcanized at 160° C. for 20 minutes to prepare a rubber specimen.

[0230] *Mooney viscosity (ML1+4, @100°C): For each rubber composition, Mooney viscosity was measured at 100°C using a Monsanto MV2000E large rotor at a rotor speed of 2±0.02 rpm. The sample used in this case was allowed to stand at room temperature (23±3°C) for 30 minutes or longer, 27±3 g of which was collected and filled into a mold cavity. The Mooney viscosity was measured while applying torque to the press plate. In addition, the difference (ΔMV) between the measured Mooney viscosity of the rubber composition and the Mooney viscosity of the conjugated diene polymer measured in Experimental Example 1 was calculated.

[0231] Furthermore, using the measured value of Comparative Example 1 as a reference value, the difference in Mooney viscosity between each Example and Comparative Example was indexed using the following equation 3, and the processability was confirmed by the value, with a larger value indicating better.

[0232] [Equation 3]

[0233] Processability = {[(reference value - measured value) / reference value] × 100} + 100

[0234] *Tensile properties: After vulcanizing each of the rubber compositions prepared above at 150° C. for 90 minutes, the modulus of the vulcanized product at 300% elongation (M-300%, kg·f / cm 2 ). Using the measured value of Comparative Example 1 as a reference value, the 300% modulus of each Example and Comparative Example was indexed using the following equation 4. The higher the value, the better.

[0235] [Equation 4]

[0236] M-300% index = (measured value / reference value) × 100

[0237] *Viscoelastic properties: Viscoelastic coefficient (Tan δ) was measured using a DMTS 500N from Gabo, Germany, at -60°C to 60°C, at a frequency of 10 Hz, a 3% pre-strain, and a 3% dynamic strain. In this case, the Tan δ value at 60°C represents rolling resistance characteristics (fuel efficiency). The measured value of Comparative Example 1 was used as a reference, and the viscoelastic properties of each Example and Comparative Example were indexed using the following Equation 5.

[0238] [Equation 5]

[0239] Tanδ@60℃ index={[(reference value-measured value) / reference value]×100}+100

[0240] *Abrasion resistance: For each rubber specimen prepared above, a DIN abrasion resistance test was performed according to ASTM D5963, and the results were expressed as a DIN weight loss index (loss volume index: ARIA (Abrasion Resistance Index, Method A)). The measured value of Comparative Example 1 was used as a reference value, and the abrasion resistance of each Example and Comparative Example was indexed using the following Equation 6.

[0241] [Equation 5]

[0242] Wear resistance index = {[(reference value - measured value) / reference value] × 100} + 100

[0243] [Table 2]

[0244]

[0245] As shown in Table 2 above, Examples 1 to 6 exhibited improved wear resistance and significantly enhanced processability while maintaining tensile and viscoelastic properties at the same levels as Comparative Examples 1 to 5.

[0246] From these results, it was confirmed that the conjugated diene polymer of the present invention exhibits improved processability by introducing branches into the linear conjugated diene polymer, while maintaining the properties of the conjugated diene polymer other than processability at the level of the high linear conjugated diene polymer, and maintaining the incorporation property into the rubber composition at a high level.

Claims

1. A conjugated diene polymer, wherein: Containing conjugated diene monomer units, Having a cis bond content of 95.0% by weight or more, having a molecular weight distribution (Mw / Mn) of 2.3 to 2.8, and The height retention rate (ΔH) calculated by the following equation 1 is 30% or more. @20℃ ): [Equation 1] ΔH @20℃ (%)=(H 8@20℃ / H 0@20℃ )×100 In Equation 1, H 0@20℃ The initial height is measured by molding 2.5 g of a conjugated diene-based polymer into a cylindrical shape having a diameter of 15 mm and a height of 12 mm at 100° C. to prepare a sample, and then cooling the sample to a temperature of 20° C., and H 8@20℃ It is the height of the sample measured after a load of 5 kg is applied to the upper surface of the sample for 8 minutes while maintaining a temperature of 20°C.

2. The conjugated diene polymer according to claim 1, wherein The height retention rate (ΔH) calculated by Equation 1 @20℃ ) is more than 35%.

3. The conjugated diene polymer according to claim 1, wherein The height retention rate (ΔH) was calculated by the following equation 2. @40℃ ) is 18% or more: [Equation 2] ΔH @40℃ (%)=(H 8@40℃ / H 0@40℃ )×100 In Equation 2, H 0@40℃ The initial height is measured by molding 2.5 g of a conjugated diene-based polymer into a cylindrical shape having a diameter of 15 mm and a height of 12 mm at 100° C. to prepare a sample, and then cooling the sample to a temperature of 40° C., and H 8@40℃ It is the height of the sample measured after a load of 5 kg is applied to the upper surface of the sample for 8 minutes while maintaining a temperature of 40°C.

4. The conjugated diene polymer according to claim 3, wherein The height retention rate (ΔH) calculated by Equation 2 @40℃ ) is more than 24%.

5. The conjugated diene polymer according to claim 1, wherein The β value measured at 100°C is 0.2 or less.

6. The conjugated diene polymer according to claim 1, wherein The molecular weight distribution (Mw / Mn) is 2.5 to 2.

8.

7. The conjugated diene polymer according to claim 1, wherein The Mooney viscosity (ML1+4@100°C) measured at 100°C is 40 to 50.

8. The conjugated diene polymer according to claim 1, wherein The weight average molecular weight of the conjugated diene polymer is 500,000 g / mol to 800,000 g / mol. 9 . A rubber composition comprising the conjugated diene polymer according to claim 1 .

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