Modifier, modified conjugated diene polymer containing the same, and method for producing the polymer

Abstract

The present invention relates to a modifying agent which is useful for modifying a conjugated diene polymer, has excellent affinity with a filler, and can improve the blend properties of the conjugated diene polymer, a modified conjugated diene polymer containing a functional group derived from the modifying agent, and a method for producing the modified conjugated diene polymer.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0178529, filed December 19, 2022, and all contents disclosed in the documents of this Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a modifier that is useful for modifying a conjugated diene polymer, has excellent affinity with a filler, and can improve the blending properties of the conjugated diene polymer; a modified conjugated diene polymer containing a functional group derived from the modifier; and a method for producing the modified conjugated diene polymer. [Background technology]

[0003] In recent years, with the demand for improved fuel economy in automobiles, there has been a demand for conjugated diene polymers as rubber materials for tires that have low rolling resistance, excellent abrasion resistance and tensile properties, as well as adjustment stability, as typified by wet skid resistance.

[0004] One method for reducing the rolling resistance of a tire is to reduce the hysteresis loss of vulcanized rubber, and the evaluation indexes for such vulcanized rubber include rebound resilience, tan δ, Goodrich heat generation, etc. at 50°C to 80°C. That is, a rubber material that has high rebound resilience or low tan δ and Goodrich heat generation at the above temperatures is preferred.

[0005] Known rubber materials with low hysteresis loss include natural rubber, polyisoprene rubber, and polybutadiene rubber. However, these materials suffer from poor wet skid resistance. Therefore, conjugated diene polymers or copolymers, such as styrene-butadiene rubber (SBR) or butadiene rubber (BR), have recently been produced by emulsion polymerization or solution polymerization and used as tire rubber. The greatest advantage of solution polymerization over emulsion polymerization is its ability to freely adjust the vinyl and styrene content, which determine the rubber's physical properties, and its ability to control molecular weight and physical properties through coupling and modification. Therefore, solution-polymerized SBR is widely used as a tire rubber material because the final SBR or BR can be easily modified, and chain end bonding or modification can reduce chain end movement and increase the bonding strength with fillers such as silica or carbon black.

[0006] When such solution-polymerized SBR is used as a rubber material for tires, increasing the vinyl content in the SBR raises the rubber's glass transition temperature, thereby enabling adjustment of tire properties such as rolling resistance and braking force, as well as reducing fuel consumption. The solution-polymerized SBR is produced using an anionic polymerization initiator, and the chain ends of the resulting polymer are bonded or modified using various modifiers. For example, U.S. Patent No. 4,397,994 proposes a technology in which active anions at the chain ends of a polymer obtained by polymerizing styrene-butadiene in a nonpolar solvent using a monofunctional alkyllithium initiator are bonded using a bonding agent such as a tin compound.

[0007] Carbon black and silica are commonly used as reinforcing fillers in tire treads. Silica offers the advantages of low hysteresis loss and improved wet skid resistance. However, silica, with its hydrophilic surface, has a lower affinity with rubber than carbon black, with its hydrophobic surface, resulting in poor dispersibility. Therefore, it is necessary to improve dispersibility or use a separate silane coupling agent to bond the silica and rubber. Therefore, attempts have been made to introduce functional groups with affinity and reactivity with silica into the terminals of rubber molecules, but these methods have not been effective enough. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] US4397994A Summary of the Invention [Problem to be solved by the invention]

[0009] An object of the present invention is to provide a modifier which is useful for modifying a conjugated diene polymer, has excellent affinity with a filler, and can improve the compounding properties of the conjugated diene polymer. [Means for solving the problem]

[0010] In order to solve the above problems, the present invention provides a denaturing agent having a novel structure.

[0011] (1) The present invention provides a denaturing agent represented by the following chemical formula 1:

[0012] [ka]

[0013] In the above Chemical Formula 1, A is an arylene group having 6 to 20 carbon atoms or a heteroarylene group having 5 to 20 carbon atoms; L1 and L2 each independently represent an alkylene group having 1 to 20 carbon atoms; L3 and L4 each independently represent an alkylene group having 1 to 20 carbon atoms; R1 to R6 are each independently an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 20 carbon atoms, wherein at least one of R1 to R3 is an alkoxy group having 1 to 20 carbon atoms, and at least one of R4 to R6 is an alkoxy group having 1 to 20 carbon atoms.

[0014] (2) The present invention provides the modifying agent according to (1) above, wherein in Chemical Formula 1, A is an arylene group having 6 to 10 carbon atoms or a heteroarylene group having 5 to 10 carbon atoms.

[0015] (3) The present invention provides the modifying agent according to (1) or (2), wherein, in Chemical Formula 1, L1 and L2 are each independently an alkylene group having 1 to 10 carbon atoms, and L1 and L2 are the same as each other; and L3 and L4 are each independently an alkylene group having 1 to 10 carbon atoms, and L3 and L4 are the same as each other.

[0016] (4) The present invention provides the modifying agent according to any one of (1) to (3) above, wherein in Chemical Formula 1, R1 to R6 are each independently an alkoxy group having 1 to 10 carbon atoms.

[0017] (5) The present invention provides the denaturing agent according to any one of (1) to (4) above, wherein the denaturing agent represented by Chemical Formula 1 is selected from compounds represented by the following Chemical Formula 1A and Chemical Formula 1B:

[0018] [ka]

[0019] [ka]

[0020] In the above Chemical Formula 1A and Chemical Formula 1B, The definitions of L1 to L4 and R1 to R6 are the same as those in Chemical Formula 1 above.

[0021] (6) The present invention provides the denaturing agent according to any one of (1) to (5) above, wherein the denaturing agent represented by Chemical Formula 1 is selected from compounds represented by the following Chemical Formula 1-1 and Chemical Formula 1-2:

[0022] [ka]

[0023] [ka] [Effects of the Invention]

[0024] By using the modifying agent according to the present invention, a modified conjugated diene polymer can be produced at a high modification rate, and a modified conjugated diene polymer having excellent affinity with fillers and exhibiting excellent processability and compounding properties can be produced. DETAILED DESCRIPTION OF THE INVENTION

[0025] The present invention will now be described in more detail so that the present invention may be more easily understood.

[0026] The terms and words used in the description of the present invention and the claims should not be interpreted in a limited way to their ordinary or dictionary meanings, but should be interpreted in a way that is consistent with the technical idea of ​​the present invention, based on the principle that the inventors can appropriately define the concepts of terms in order to best describe their invention.

[0027] The present invention will be described in detail below.

[0028] Definition of Terms The term "substituted" used in the present invention means that hydrogen atoms of a functional group, atomic group, or compound are substituted with a specific substituent, and when hydrogen atoms of a functional group, atomic group, or compound are substituted with a specific substituent, one or more substituents may be present depending on the number of hydrogen atoms present in the functional group, atomic group, or compound. When multiple substituents are present, the respective substituents may be the same or different from each other.

[0029] As used herein, the term "alkyl group" means a monovalent aliphatic saturated hydrocarbon group and can include both straight-chain alkyl groups such as methyl, ethyl, propyl, and butyl, and branched alkyl groups such as isopropyl, sec-butyl, tert-butyl, and neo-pentyl.

[0030] As used herein, the term "alkylene group" may refer to a divalent aliphatic saturated hydrocarbon such as methylene, ethylene, propylene, and butylene.

[0031] The term "alkoxy group" used in the present invention may include any functional group, atomic group, or compound in which the terminal hydrogen of an alkyl group is replaced with an oxygen atom, such as methoxy, ethoxy, propoxy, and butoxy.

[0032] As used herein, the term "heteroalkyl group" may refer to an alkyl group in which any carbon atom in the alkyl group (excluding the terminal carbon atom) has been replaced with one or more heteroatoms.

[0033] As used herein, the term "cycloalkyl group" may refer to a cyclic saturated hydrocarbon.

[0034] The term "aryl group" as used herein means an aromatic hydrocarbon, and may include both monocyclic aromatic hydrocarbons in which one ring is formed, and polycyclic aromatic hydrocarbons in which two or more rings are linked together.

[0035] As used herein, the term "heteroaryl group" may be meant to include any aryl group in which one or more carbon atoms in the aryl group have been replaced with heteroatoms.

[0036] In the present invention, the terms "derived unit" and "derived functional group" can mean a component or structure derived from a certain substance, or the substance itself.

[0037] The present invention provides a denaturing agent represented by the following Chemical Formula 1:

[0038] [ka]

[0039] In the above Chemical Formula 1, A is an arylene group having 6 to 20 carbon atoms or a heteroarylene group having 5 to 20 carbon atoms; L1 and L2 each independently represent an alkylene group having 1 to 20 carbon atoms; L3 and L4 each independently represent an alkylene group having 1 to 20 carbon atoms; R1 to R6 are each independently an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 20 carbon atoms, wherein at least one of R1 to R3 is an alkoxy group having 1 to 20 carbon atoms, and at least one of R4 to R6 is an alkoxy group having 1 to 20 carbon atoms.

[0040] Specifically, in Chemical Formula 1, A is an arylene group having 6 to 20 carbon atoms or a heteroarylene group having 5 to 20 carbon atoms, and may be an arylene group having 6 to 10 carbon atoms or a heteroarylene group having 5 to 10 carbon atoms. Specifically, A is an arylene group such as a phenylene group, a naphthalene group, a biphenylene group, an anthracenylene group, a phenanthrenylene group, or a fluorenylene group, and may be a heteroarylene group containing one or more O, N, S, and P atoms as heteroelements, such as a pyridinylene group, a pyrimidinylene group, a triazinylene group, a thiophenylene group, a furanylene group, a dibenzothiophenylene group, a dibenzofuranylene group, or a carbazolylene group.

[0041] Specifically, in Chemical Formula 1, L1 to L4 are each independently an alkylene group having 1 to 20 carbon atoms, L1 and L2 are each independently an alkylene group having 1 to 10 carbon atoms, and L1 and L2 may be the same as each other, and L3 and L4 are each independently an alkylene group having 1 to 10 carbon atoms, and L3 and L4 may be the same as each other. For example, L1 and L2 may be the same as each other and an alkylene group having 1 to 10 carbon atoms, an alkylene group having 1 to 6 carbon atoms, a methylene group, an ethylene group, a propylene group, a butylene group, etc., and L3 and L4 may be the same as each other and an alkylene group having 1 to 10 carbon atoms, an alkylene group having 1 to 6 carbon atoms, a methylene group, an ethylene group, a propylene group, a butylene group, etc., and L1 to L4 may all be a propylene group.

[0042] Specifically, in Chemical Formula 1, R1 to R6 are alkyl groups having 1 to 10 carbon atoms or alkoxy groups having 1 to 20 carbon atoms, wherein at least one of R1 to R3 is an alkoxy group having 1 to 20 carbon atoms, and at least one of R4 to R6 is an alkoxy group having 1 to 20 carbon atoms. More specifically, R1 to R6 may all be alkoxy groups having 1 to 10 carbon atoms, such as an alkoxy group having 1 to 6 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a methoxy group, or an ethoxy group.

[0043] Specifically, the modifying agent represented by Chemical Formula 1 may be selected from compounds represented by the following Chemical Formula 1A and Chemical Formula 1B.

[0044] [ka]

[0045] [ka]

[0046] In the above Chemical Formula 1A and Chemical Formula 1B, The definitions of L1 to L4 and R1 to R6 are the same as those in Chemical Formula 1 above.

[0047] The modifier represented by Chemical Formula 1 contains more alkoxysilane functional groups than conventional modifiers, making it possible to produce high molecular weight modified conjugated diene polymers, and the presence of silica affinity functional groups such as O and N allows it to exhibit excellent compounding properties through interaction with silica-based fillers. In addition, the modifier represented by Chemical Formula 1 itself is structurally planar, making it easy to undergo a bonding reaction with the polymer during the modification process.

[0048] The modifying agent represented by Chemical Formula 1 may be selected from compounds represented by the following Chemical Formula 1-1 and Chemical Formula 1-2.

[0049] [ka]

[0050] [ka]

[0051] The denaturant represented by Chemical Formula 1 according to the present invention can be prepared by reacting a compound represented by Chemical Formula 2 below with a compound represented by Chemical Formula 3 or Chemical Formula 4 below:

[0052] [ka]

[0053] [ka]

[0054] [ka]

[0055] In the above formula 2, A1 and A2 are each independently a halogen element, specifically Cl.

[0056] In the chemical formulas 2 to 4, the definitions of the respective substituents are as defined above.

[0057] In the above step, the compound represented by Chemical Formula 2 and the compound represented by Chemical Formula 3 or Chemical Formula 4 may be reacted in a molar ratio of 1:1.5 to 1:5.0, a molar ratio of 1:1.5 to 1:3.0, or a molar ratio of 1:1.5 to 1:2.5.

[0058] In the above step, the reaction of the compound represented by Chemical Formula 2 with the compound represented by Chemical Formula 3 or Chemical Formula 4 may be carried out at a temperature of 20 to 200°C, 30 to 180°C, or 40 to 150°C for 1 to 72 hours.

[0059] Using the modifying agent represented by Chemical Formula 1 of the present invention, a modified conjugated diene polymer containing a repeating unit derived from a conjugated diene monomer and containing a functional group derived from the modifying agent represented by Chemical Formula 1 at at least one terminal can be produced.

[0060] The repeating unit derived from the conjugated diene monomer refers to a repeating unit formed by the conjugated diene monomer during polymerization, and the conjugated diene monomer may be, for example, one or more selected from the group consisting of 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, piperylene, 3-butyl-1,3-octadiene, isoprene, 2-phenyl-1,3-butadiene, and 2-halo-1,3-butadiene (halo means a halogen atom).

[0061] Meanwhile, the modified conjugated diene copolymer may be, for example, a copolymer further including repeating units derived from an aromatic vinyl monomer in addition to repeating units derived from the conjugated diene monomer.

[0062] The repeating unit derived from the aromatic vinyl monomer refers to a repeating unit formed by polymerization of the aromatic vinyl monomer, and the aromatic vinyl monomer may be, for example, one or more selected from the group consisting of styrene, α-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-propylstyrene, 1-vinylnaphthalene, 4-cyclohexylstyrene, 4-(p-methylphenyl)styrene, and 1-vinyl-5-hexylnaphthalene.

[0063] When the modified conjugated diene polymer is a copolymer containing repeating units derived from an aromatic vinyl monomer, the modified conjugated diene polymer may contain at least 20 wt%, 30 wt%, 40 wt%, 50 wt%, 55 wt%, or 60 wt% of repeating units derived from the conjugated diene monomer and at most 95 wt%, 90 wt%, or 80 wt%, and at least 5 wt%, 10 wt%, or 20 wt% of repeating units derived from the aromatic vinyl monomer and at most 80 wt%, 70 wt%, 60 wt%, 55 wt%, 50 wt%, 45 wt%, or 40 wt%, respectively. When the content is within these ranges, excellent rolling resistance, wet skid resistance, and abrasion resistance are achieved.

[0064] According to an embodiment of the present invention, the copolymer may be a random copolymer, which has an excellent balance of physical properties. The random copolymer may mean a copolymer in which repeating units constituting the copolymer are randomly arranged.

[0065] The modified conjugated diene polymer according to one embodiment of the present invention may have a number-average molecular weight (Mn) of 10,000 g / mol to 2,000,000 g / mol, 50,000 g / mol to 1,800,000 g / mol, or 120,000 g / mol to 1,500,000 g / mol, and a weight-average molecular weight (Mw) of 10,000 g / mol to 5,000,000 g / mol, 100,000 g / mol to 3,500,000 g / mol, or 120,000 g / mol to 2,000,000 g / mol. When the molecular weights are within these ranges, the polymer exhibits excellent rolling resistance and wet skid resistance. As yet another example, the modified conjugated diene polymer may have a molecular weight distribution (Mw / Mn) of 1.0 to 8.0, 1.0 to 4.0, or 1.0 to 3.5, and when it is within this range, it has the effect of achieving an excellent balance between physical properties.

[0066] Here, the weight average molecular weight (Mw) and number average molecular weight (Mn) are polystyrene equivalent molecular weights analyzed by gel permeation chromatography (GPC), and the molecular weight distribution (Mw / Mn) is also called polydispersity and is calculated as the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn).

[0067] As yet another example, the modified conjugated diene polymer may have a Mooney viscosity of 20 to 150 at 100° C. and 20 to 150 at 140° C. When the viscosity is within this range, excellent processability and productivity can be achieved.

[0068] The Mooney viscosity is measured using a Mooney viscometer, for example, a MV2000E (ALPHA Technologies) large rotor, at 100°C and 140°C with a rotor speed of 2±0.02 rpm. Specifically, the polymer is left at room temperature (23±5°C) for 30 minutes or more, and then 27±3 g is taken and filled into the die cavity. The platen is operated to apply torque and the viscosity is measured.

[0069] The modified conjugated diene polymer may have a vinyl content of 5 wt% or more, 10 wt% or more, or 10 wt% to 60 wt%. Within this range, the glass transition temperature is controlled within an appropriate range, resulting in excellent rolling resistance, wet skid resistance, and fuel economy. Here, the vinyl content may refer to the content of 1,2-added, rather than 1,4-added, conjugated diene monomers relative to 100 wt% of a conjugated diene copolymer composed of a vinyl-containing monomer and an aromatic vinyl monomer.

[0070] On the other hand, the terms "derived repeating unit", "derived functional group", and "derived group" used in the present invention can mean a component or structure originating from a certain substance, or the substance itself.

[0071] Method for producing modified conjugated diene polymer The present invention also provides a method for producing the modified conjugated diene polymer.

[0072] The method for producing the modified conjugated diene polymer according to one embodiment of the present invention includes the steps of: (S1) polymerizing a conjugated diene monomer, or an aromatic vinyl monomer and a conjugated diene monomer, in a hydrocarbon solvent containing an organometallic compound to produce an activated polymer having an organometallic bond (Step 1); and (S2) reacting the activated polymer with a modifier represented by the following Chemical Formula 1 (Step 2).

[0073] [ka]

[0074] The definitions of each substituent in Chemical Formula 1 are as defined above.

[0075] Step 1 is a step for preparing an activated polymer bound to an organometallic compound, and can be performed by polymerizing a conjugated diene monomer, or an aromatic vinyl monomer and a conjugated diene monomer, in a hydrocarbon solvent containing an organometallic compound.

[0076] The hydrocarbon solvent is not particularly limited, and may be, for example, one or more selected from the group consisting of n-pentane, n-hexane, n-heptane, isooctane, cyclohexane, toluene, benzene, and xylene.

[0077] The conjugated diene monomer and aromatic vinyl monomer are as defined above.

[0078] According to one embodiment of the present invention, the organometallic compound may be used in an amount of 0.01 to 10 mmol, 0.05 to 5 mmol, 0.1 to 2 mmol, 0.1 to 1 mmol, or 0.15 to 0.8 mmol based on 100 g of the total monomers.

[0079] The organometallic compound may be, for example, one or more selected from the group consisting of methyllithium, ethyllithium, propyllithium, n-butyllithium, s-butyllithium, t-butyllithium, hexyllithium, n-decyllithium, t-octyllithium, phenyllithium, 1-naphthyllithium, n-eicosyllithium, 4-butylphenyllithium, 4-tolyllithium, cyclohexyllithium, 3,5-di-n-heptylcyclohexyllithium, 4-cyclopentyllithium, naphthyl sodium, naphthylpotassium, lithium alkoxide, sodium alkoxide, potassium alkoxide, lithium sulfonate, sodium sulfonate, potassium sulfonate, lithium amide, sodium amide, potassium amide, and lithium isopropylamide.

[0080] Meanwhile, the polymerization in step 1 may be carried out in the presence of a polar additive, and the polar additive may be added in an amount of 0.001 g to 50 g, 0.001 g to 10 g, 0.005 g to 0.2 g, or 0.01 g to 0.2 g based on a total of 100 g of the monomers.

[0081] The polar additive may be at least one selected from the group consisting of tetrahydrofuran, 2,2-di(tetrahydrofuryl)propane, diethyl ether, cyclopentyl ether, dipropyl ether, ethylene dimethyl ether, diethyl glycol, dimethyl ether, tert-butoxyethoxyethane, bis(3-dimethylaminoethyl)ether, (dimethylaminoethyl)ethyl ether, trimethylamine, triethylamine, tripropylamine, and tetramethylethylenediamine, and may be specifically triethylamine or tetramethylethylenediamine. The polar additive may be present in the copolymerization of a conjugated diene monomer, or a conjugated diene monomer and an aromatic vinyl monomer, to compensate for the difference in reaction rate, thereby facilitating the formation of a random copolymer.

[0082] The polymerization in step 1 may be, for example, anionic polymerization, specifically, living anionic polymerization with anionic active sites at the polymerization terminus through an anionic propagation polymerization reaction. The polymerization in step 1 may be temperature-rising polymerization, isothermal polymerization, or constant-temperature polymerization (adiabatic polymerization). The constant-temperature polymerization refers to a polymerization method that involves polymerizing an organometallic compound using its own reaction heat without adding heat after the compound is added. The temperature-rising polymerization refers to a polymerization method that involves adding heat after the compound is added to increase the temperature. The isothermal polymerization refers to a polymerization method that involves adding heat after the compound is added to increase the temperature, or removing heat to maintain a constant temperature of the polymer.

[0083] The polymerization in step 1 may be carried out at a temperature ranging from -20 to 80°C, 0 to 80°C, 10 to 80°C, or 10 to 70°C, for example.

[0084] The activated polymer prepared in step 1 may refer to a polymer in which a polymer anion and an organometallic cation are bonded.

[0085] Step 2 is a step of reacting the activated polymer with the modifier represented by Chemical Formula 1 to produce a modified conjugated diene-based polymer.

[0086] According to one embodiment of the present invention, the modifying agent represented by Formula 1 may be used in an amount of 0.1 to 100 g, 0.1 to 50 g, specifically 0.1 to 25 g, based on 100 g of the total monomers.

[0087] According to one embodiment of the present invention, the modifier represented by Chemical Formula 1 and the organometallic compound may be used in a molar ratio of 1:0.1 to 1:10, a molar ratio of 1:0.1 to 1:5, or a molar ratio of 1:0.2 to 1:4. When the ratio is within this range, a modification reaction with optimal performance can be performed.

[0088] The reaction in step 2 is a modification reaction for introducing functional groups derived from the modifying agent into the activated polymer, and may be carried out at 0° C. to 90° C. for 1 minute to 5 hours.

[0089] According to one embodiment of the present invention, the method for producing the modified conjugated diene polymer may be carried out by a batch polymerization method or a continuous polymerization method including one or more reactors.

[0090] For example, the method for producing the modified conjugated diene-based polymer may further include, following step 2 of the present invention, one or more steps of recovering and drying the solvent and unreacted monomers, if necessary.

[0091] rubber composition Furthermore, the present invention provides a rubber composition containing the modified conjugated diene polymer.

[0092] The rubber composition according to one embodiment of the present invention may contain the modified conjugated diene polymer in an amount of 10% by weight or more, 10% to 100% by weight, or 20% to 90% by weight. When the amount is within this range, the rubber composition has excellent mechanical properties such as tensile strength and abrasion resistance, and an excellent balance between the various physical properties.

[0093] In addition to the modified conjugated diene polymer, the rubber composition may further contain other rubber components as needed, and in this case, the rubber components may be contained in an amount of 90% by weight or less based on the total weight of the rubber composition. As a specific example, the other rubber components may be contained in an amount of 1 part by weight to 900 parts by weight based on 100 parts by weight of the modified conjugated diene polymer.

[0094] The rubber component may be, for example, natural rubber or synthetic rubber, and specific examples thereof include natural rubber (NR) containing cis-1,4-polyisoprene; modified natural rubbers obtained by modifying or refining the general natural rubbers, such as epoxidized natural rubber (ENR), deproteinized natural rubber (DPNR), and hydrogenated natural rubber; styrene-butadiene copolymer (SBR), polybutadiene (BR), polyisoprene (IR), butyl rubber (IIR), ethylene-propylene copolymer, polyisobutylene-co-isoprene, The rubber may be a synthetic rubber such as neoprene, 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, acrylic rubber, urethane rubber, silicone rubber, epichlorohydrin rubber, or halogenated butyl rubber, and any one or a mixture of two or more of these may be used.

[0095] The rubber composition may contain, for example, 0.1 to 200 parts by weight, or 10 to 120 parts by weight, of a filler relative to 100 parts by weight of the modified conjugated diene polymer of the present invention. The filler may be, for example, a silica-based filler, and specific examples thereof include wet silica (hydrated silicic acid), dry silica (anhydrous silicic acid), calcium silicate, aluminum silicate, and colloidal silica. Wet silica is preferred, as it provides the best balance between improved fracture properties and wet grip. The rubber composition may further contain a carbon black-based filler, if necessary.

[0096] As another example, when silica is used as the filler, a silane coupling agent may be used together to improve reinforcing properties and low heat buildup. Specific examples of the silane coupling agent include 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-dimethylthiocarbamoyltetrasulfide, and the like. The polysilyl group may be, for example, 2-triethoxysilylethyl-N,N-dimethylthiocarbamoyl tetrasulfide, 3-trimethoxysilylpropyl benzothiazolyl tetrasulfide, 3-triethoxysilylpropyl benzolyl tetrasulfide, 3-triethoxysilylpropyl methacrylate monosulfide, 3-trimethoxysilylpropyl methacrylate monosulfide, bis(3-diethoxymethylsilylpropyl)tetrasulfide, 3-mercaptopropyldimethoxymethylsilane, dimethoxymethylsilylpropyl-N,N-dimethylthiocarbamoyl tetrasulfide, or dimethoxymethylsilylpropyl benzothiazolyl tetrasulfide, and any one or a mixture of two or more of these may be used. In consideration of the effect of improving reinforcement, bis(3-triethoxysilylpropyl)polysulfide or 3-trimethoxysilylpropylbenzothiazyl tetrasulfide may be preferably used.

[0097] Furthermore, the rubber composition according to one embodiment of the present invention uses, as the rubber component, a modified conjugated diene polymer having a functional group with high affinity for silica introduced into the active site, so the amount of silane coupling agent can be reduced compared to conventional cases. Therefore, the silane coupling agent may be used in an amount of 1 to 20 parts by weight, or 5 to 15 parts by weight, per 100 parts by weight of silica. Within these ranges, the silane coupling agent can be used to its full potential while preventing gelation of the rubber component.

[0098] The rubber composition according to one embodiment of the present invention may be sulfur crosslinkable and may further contain a vulcanizing agent. Specifically, the vulcanizing agent may be sulfur powder, and may be contained in an amount of 0.1 to 10 parts by weight per 100 parts by weight of the rubber component. When the amount is within this range, the vulcanized rubber composition can ensure the required elastic modulus and strength, and also has excellent fuel economy.

[0099] In addition to the above components, the rubber composition according to an embodiment of the present invention may further include various additives commonly used in the rubber industry, specifically, a vulcanization accelerator, process oil, plasticizer, antioxidant, scorch inhibitor, zinc white, stearic acid, a thermosetting resin, or a thermoplastic resin.

[0100] As the vulcanization accelerator, for example, thiazole compounds such as M (2-mercaptobenzothiazole), DM (dibenzothiazyl disulfide), and CZ (N-cyclohexyl-2-benzothiazyl sulfenamide), or guanidine compounds such as DPG (diphenyl guanidine) can be used, and they may be contained in an amount of 0.1 to 5 parts by weight per 100 parts by weight of the rubber component.

[0101] The process oil acts as a softener in the rubber composition and may be, for example, a paraffinic, naphthenic, or aromatic compound. Aromatic process oils are used in consideration of tensile strength and abrasion resistance, while naphthenic or paraffinic process oils are used in consideration of hysteresis loss and low-temperature properties. The process oil may be contained in an amount of, for example, 100 parts by weight or less per 100 parts by weight of the rubber component. When the amount is within this range, it is effective in preventing a decrease in the tensile strength and low heat buildup (fuel economy) of the vulcanized rubber.

[0102] Examples of the antioxidant include 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, and may be used in an amount of 0.1 to 6 parts by weight per 100 parts by weight of the rubber component.

[0103] The rubber composition according to one embodiment of the present invention is obtained by kneading the rubber composition according to the compounding recipe using a kneading machine such as a Banbury mixer, a roll, or an internal mixer. After molding and processing, a vulcanization step is carried out to obtain a rubber composition having low heat buildup and excellent abrasion resistance.

[0104] As a result, the rubber composition is useful in the production of tire components such as tire treads, undertreads, sidewalls, carcass coating rubbers, belt coating rubbers, bead fillers, chafers, and bead coating rubbers, as well as various industrial rubber products such as dustproof rubbers, belt conveyors, and hoses.

[0105] The present invention also provides a tire manufactured using the rubber composition.

[0106] The tire may include a tire or a tire tread.

[0107] Example The present invention will be described in more detail below with reference to examples. However, the following examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

[0108] Manufacturing Example 1 (1) Synthesis of 1,4-bis(3-chloropropoxy)benzene A 250 mL flask was charged with hydroquinone (5.0 g, 45.4 mmol), 1-bromo-3-chloropropane (11.2 g), potassium phosphate (38.56 g), and methanol (45.4 mL) and refluxed overnight. The reaction was quenched with water and dichloromethane. The product was finally dried to give the product. 1 H NMR(CDCl3, 500 MHz): 6.84 ppm(s, 4H), 4.07 ppm(m, 4H), 3.74 ppm(m, 4H), 2.21 ppm(m, 4H)

[0109] (2) Synthesis of 3,3'-(1,4-phenylenebis(oxy)bis(N,N-bis(3-(trimethoxysilyl)propyl)propan-1-amine) 1,4-bis(3-chloropropoxy)benzene (5.7 g, 21.8 mmol), trimethylamine (4.6 mL), and bis(3-(trimethoxysilyl)propyl)amine (15.7 mL) were placed in a 100 mL flask and stirred overnight at 150° C. After the reaction was completed, the product was filtered and dried in vacuo. The H nuclear magnetic resonance spectroscopy spectrum was observed and it was confirmed that the compound was represented by the following chemical formula: 1 H NMR(CDCl3, 500 MHz): 6.80 ppm(s, 4H), 3.93 ppm(m, 4H), 3.55 ppm(s, 36H), 2.57 ppm(m, 4H), 2.41 ppm(m, 8H), 1.86 ppm(m, 4H), 1.53 ppm(m, 8H), 0.60 ppm(m, 8H)

[0110] [ka]

[0111] Manufacturing Example 2 (1) Synthesis of 1,5-bis(3-chloropropoxy)naphthalene A 250 mL flask was charged with naphthalene-1,5-diol (5.0 g, 31.2 mmol), 1-bromo-3-chloropropane (7.72 g), potassium phosphate (26.5 g), and methanol (31.2 mL) and refluxed overnight. After the reaction, the mixture was quenched with water and dichloromethane. The product was finally dried to give the product. 1 H NMR(CDCl3, 500 MHz): 7.81 ppm(m, 2H), 7.38 ppm(m, 2H), 6.86 ppm(m, 2H), 4.28 ppm(m, 4H), 3.70 ppm(m, 4H), 2.46 ppm(m, 4H)

[0112] (2) Synthesis of 3,3'-(naphthalene-1,5-diylbis(oxy))bis(N,N-bis(3-(trimethoxysilyl)propyl)propan-1-amine) 1,5-bis(3-chloropropoxy)naphthalene (5.1 g, 16.3 mmol), trimethylamine (6.8 mL), and bis(3-(trimethoxysilyl)propyl)amine (11.8 mL) were placed in a 100 mL flask and stirred overnight at 150° C. After the reaction was completed, the product was filtered and dried in vacuo. The H nuclear magnetic resonance spectroscopy spectrum was observed and it was confirmed that the compound was represented by the following chemical formula:

[0113] 1 H NMR(CDCl3, 500 MHz): 7.79 ppm(s, 2H), 7.33 ppm(s, 2H), 4.18 ppm(m, 4H), 3.55 ppm(s, 36H), 2.95 ppm(m, 4H), 2.62 ppm(m, 4H), 1.67 ppm(m, 8H), 1.31 ppm(m, 8H), 0.62 ppm(m, 8H)

[0114] [ka]

[0115] Example 1 A 20 L autoclave reactor was charged with 4.733 g of n-hexane, 375.0 g of styrene, 593.8 g of 1,3-butadiene, and 1.4 g of N,N,N',N'-tetramethylethylenediamine (TMEDA) as a polar additive, followed by 5.0 g of n-butyllithium (10 wt% in n-hexane). The internal temperature of the reactor was adjusted to 40°C to allow an adiabatic heating reaction to proceed. After approximately 30 minutes, 31.3 g of 1,3-butadiene was charged to cap the polymer ends with butadiene.

[0116] Then, 2.0 g of the compound represented by Chemical Formula 1-1 prepared in Preparation Example 1 was added as a modifier ([TMEDA]:[act.Li] = 3.1:1 molar ratio, [modifier]:[act.Li] = 0.3:1 molar ratio). The reaction was then stopped using ethanol, and 17 g of a 30 wt % solution of the antioxidant Wingstay K in hexane was added. The resulting polymer was placed in steam-heated hot water and stirred to remove the solvent, followed by roll drying to remove the remaining solvent and water, producing a modified styrene-butadiene copolymer.

[0117] Example 2 A modified conjugated diene polymer was produced in the same manner as in Example 1, except that 2.2 g of the compound represented by Chemical Formula 1-2 produced in Production Example 2 was added as the modifying agent.

[0118] Comparative Example 1 A modified styrene-butadiene copolymer was produced in the same manner as in Example 1, except that 0.64 g of SiCl4 was used as a modifier and the molar ratio of [modifier]:[act.Li] was 0.48:1.

[0119] Comparative Example 2 A modified styrene-butadiene copolymer was produced in the same manner as in Example 1, except that 0.97 g of N-methyl-3-(trimethoxysilyl)-N-(3-(trimethoxysilyl)propyl)propan-1-amine was used as the modifier and the molar ratio of [modifier]:[act.Li] was 0.35:1.

[0120] Comparative Example 3 A modified styrene-butadiene copolymer was produced in the same manner as in Example 1, except that 1.4 g of tris(3-(trimethoxysilyl)propyl)amine was used as the modifier and the molar ratio of [modifier]:[act.Li] was 0.36:1.

[0121] Experimental Example 1 The modified conjugated diene polymers prepared in the examples and comparative examples were analyzed for the styrene unit content, vinyl content, weight average molecular weight (Mw, × 10 3 g / mol), number average molecular weight (Mn, ×10 3 g / mol), molecular weight distribution (MWD), and Mooney viscosity (MV) were measured, respectively.

[0122] 1) Styrene bond content and 1,2-vinyl bond content The styrene bond content (SM) and 1,2-vinyl bond content (Vi) in each polymer were measured and analyzed using a Varian VNMRS 500 MHz NMR. 1,1,2,2-tetrachloroethane was used as the solvent during NMR measurement, and the solvent peak was calculated at 6.00 ppm. The styrene unit bond content and 1,2-vinyl bond content were calculated using the peaks from 7.2 to 6.9 ppm for random styrene, 6.9 to 6.2 ppm for block styrene, 5.8 to 5.1 ppm for 1,4-vinyl and 1,2-vinyl, and 5.1 to 4.5 ppm for 1,2-vinyl.

[0123] 2) Weight average molecular weight, number average molecular weight, molecular weight distribution The weight average molecular weight (Mw) and number average molecular weight (Mn) were measured by GPC (gel permeation chromatograph) analysis, and the molecular weight distribution (MWD, Mw / Mn) was calculated from the measured molecular weights.

[0124] Specifically, the GPC was performed using two PLgel Olexis (Polymer Laboratories) columns and one PLgel mixed-C (Polymer Laboratories) column, and both of the newly replaced columns were mixed-bed columns. Furthermore, when calculating molecular weight, PS (polystyrene) was used as the GPC standard material.

[0125] 3) Mooney viscosity The Mooney viscosity (MV, (ML1+4, @100°C MU)) was measured at 100°C using an MV-2000 (ALPHA Technologies) at a rotor speed of 2±0.02 rpm and a large rotor. The sample used was left to stand at room temperature (23±5°C) for 30 minutes or more, and then 27±3 g of the sample was taken and filled into the die cavity. The platen was operated and the measurement was performed for 4 minutes.

[0126] [Table 1]

[0127] As shown in the above results, the modified conjugated diene-based polymers of the Examples using the modifier represented by Chemical Formula 1 according to the present invention exhibited significantly higher molecular weights than the Comparative Examples, but the increase in Mooney viscosity was not as large. This indicates that the modified conjugated diene-based polymers prepared in the Examples have a star polymer structure. Furthermore, it can be seen that the modified conjugated diene-based polymers of the Examples having such a structure should have improved processability and excellent wear performance due to their high molecular weight characteristics.

[0128] Experimental Example 2 To compare and analyze the physical properties of the rubber compositions containing the modified conjugated diene-based polymers prepared in the examples and comparative examples, and the molded articles prepared therefrom, the tensile properties, abrasion resistance, and wet skid resistance were measured.

[0129] 1) Preparation of rubber test specimens The modified conjugated diene polymers of the examples and comparative examples were used as raw rubber and compounded under the compounding conditions shown in Table 2. The raw materials in Table 2 are in parts by weight based on 100 parts by weight of rubber.

[0130] [Table 2]

[0131] Specifically, the rubber test pieces are kneaded through a first-stage kneading and a second-stage kneading. In the first stage kneading, raw rubber, silica (filler), an organic silane coupling agent (X50S, Evonik), process oil (TDAE oil), zinc oxide (ZnO), stearic acid, an antioxidant (TMQ(RD) (2,2,4-trimethyl-1,2-dihydroquinoline polymer), an antioxidant (6PPD (dimethylbutyl)-N-phenyl-phenylenediamine), and a wax (microcrystalline cellulose)) are mixed using a Banbury mixer equipped with a temperature control device. Wax) was mixed into the mixer. During this process, the mixer temperature was controlled, and a primary compound was obtained at a discharge temperature of 150°C. In the second mixing stage, the primary compound was cooled to room temperature, and then the primary compound, sulfur powder, rubber accelerator (DPG (diphenyl guanidine)), and vulcanization accelerator (CZ (N-cyclohexyl-2-benzothiazyl sulfenamide)) were added to the mixer and mixed at a temperature of 100°C or less to obtain a secondary compound. This was followed by a curing process at 160°C for 20 minutes, after which rubber test specimens were prepared.

[0132] 2) Tensile properties For the tensile properties, test pieces were prepared according to the tensile test method of ASTM 412, and the tensile stress at 300% elongation (300% modulus), breaking strength (tensile strength), and tensile modulus of the test pieces were measured.

[0133] Specifically, the tensile properties were measured at room temperature at a speed of 50 cm / min using a Universal Test Machine 4204 (Instron Corp.) tensile tester. The results in Table 3 are expressed as an index (%) based on the results of Comparative Example 1, with a higher value indicating better properties.

[0134] 3) Viscoelastic properties Viscoelastic properties were measured using a dynamic mechanical analyzer (manufactured by TA) in strain mode, with tan δ measured at a frequency of 10 Hz and varying deformation at various temperatures (-60°C to 60°C). The Payne effect was expressed as the difference between the minimum and maximum values ​​at deformations of 0.28% to 40%. A higher tan δ at a low temperature of 0°C indicates better wet skid resistance, while a lower tan δ at a high temperature of 60°C indicates less hysteresis loss and better rolling resistance (fuel economy). However, the results in Table 3 are indexed using the measured value of Comparative Example 1 as the reference value, and therefore the higher the value, the better the performance.

[0135] 4) Processability characteristics The Mooney viscosity (MV, (ML1+4, at 100°C MU) of the secondary blend obtained during the preparation of the rubber test specimens (1) above was measured, and the processability of each polymer was compared and analyzed. In this case, a lower Mooney viscosity measurement value indicates better processability characteristics. The results in Table 3 are indexed using the measurement value of Comparative Example 1 as the reference value, and therefore a higher value indicates better performance.

[0136] Specifically, using a large rotor in an MV-2000 (ALPHA Technologies), the temperature was set at 100°C with a rotor speed of 2±0.02 rpm. Each secondary compound was left at room temperature (23±5°C) for 30 minutes or more, and then 27±3 g was sampled and filled into the die cavity. The platen was then operated and the measurement was carried out for 4 minutes.

[0137] 5) Abrasion resistance (DIN abrasion test) Each rubber specimen was subjected to a DIN abrasion test in accordance with ASTM D5963, and the results were expressed as a DIN loss index (loss volume index: ARIA (Abration resistance index, Method A)). A higher value indicates better performance.

[0138] [Table 3]

[0139] As shown in Table 3, it was confirmed that the modified conjugated diene polymers of the examples have the effect of improving the tensile properties, viscoelastic properties, abrasion resistance, and processability in a well-balanced manner.

[0140] From the above results, it was confirmed that the modified conjugated diene polymer of the present invention can form a high molecular weight polymer by containing a functional group derived from the modifier represented by Chemical Formula 1, and that rubber compositions containing it have improved abrasion resistance properties. It also means that it has excellent affinity with fillers, and that the processability and tensile properties of rubber compositions containing it are all improved. This shows that the modified conjugated diene polymer of the present invention, when modified with the modifier represented by Chemical Formula 1, has significant effects that cannot be achieved with polymers modified with other modifiers of similar structure.

Claims

1. A modifier for a conjugated diene copolymer represented by the following chemical formula 1. 【Chemistry 1】 (In the above chemical formula 1, A is an arylene group having 6 to 20 carbon atoms; L １ and L ２ are each independently an alkylene group having 1 to 20 carbon atoms, L ３ and L ４ are each independently an alkylene group having 1 to 20 carbon atoms, R １ ~R ６ are each independently an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 20 carbon atoms, where R １ ~R ３ At least one of R is an alkoxy group having 1 to 20 carbon atoms; ４ ~R ６ At least one of the groups is an alkoxy group having 1 to 20 carbon atoms.

2. In the above Chemical Formula 1, 2. The modifier for a conjugated diene copolymer according to claim 1, wherein A is an arylene group having 6 to 10 carbon atoms.

3. In the above Chemical Formula 1, L １ and L ２ are each independently an alkylene group having 1 to 10 carbon atoms, and L １ and L ２ are identical to each other, L ３ and L ４ are each independently an alkylene group having 1 to 10 carbon atoms, and L ３ and L ４ The modifier for a conjugated diene copolymer according to claim 1, wherein:

4. In the above Chemical Formula 1, R １ ~R ６ The modifier for a conjugated diene copolymer according to claim 1, wherein each of the groups independently represents an alkoxy group having 1 to 10 carbon atoms.

5. The modifier for a conjugated diene copolymer according to claim 1, wherein the modifier represented by Chemical Formula 1 is selected from compounds represented by the following Chemical Formula 1A and Chemical Formula 1B: 【Chemistry 2】 (In the above Chemical Formula 1A and Chemical Formula 1B, L １ ~L ４ , R １ ~R ６ is defined as in Chemical Formula 1 above.)

6. The modifier for a conjugated diene copolymer according to claim 1, wherein the modifier represented by Chemical Formula 1 is selected from compounds represented by the following Chemical Formula 1-1 and Chemical Formula 1-2: 【Transformation 3】

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