KR102724304B1 - Modified conjugated diene polymer, preparing method thereof and rubber composition comprising the same - Google Patents

Abstract

The present invention relates to a modified conjugated diene polymer having excellent processability as well as superior tensile strength and viscoelastic properties, and a rubber composition comprising the same, the modified conjugated diene polymer comprising: a polymer chain including a repeating unit derived from a conjugated diene monomer; a modified monomer-derived unit represented by Chemical Formula 1; and a functional group derived from a modifier, wherein the modified monomer-derived unit is bonded within the polymer chain and to at least one terminal, and the functional group derived from the modifier is bonded to the modified monomer-derived unit bonded to the terminal of the polymer chain.

Description

Modified conjugated diene polymer, preparation method thereof, and rubber composition comprising the same {MODIFIED CONJUGATED DIENE POLYMER, PREPARING METHOD THEREOF AND RUBBER COMPOSITION COMPRISING THE SAME}

The present invention relates to a modified conjugated diene polymer having excellent processability as well as excellent tensile strength and viscoelastic properties, a method for producing the same, and a rubber composition comprising the same.

Recently, in response to the demand for fuel efficiency in automobiles, conjugated diene polymers that have low rolling resistance, excellent wear resistance and tensile properties, and also have steering stability represented by wet road resistance are required as rubber materials for tires.

In order to reduce the rolling resistance of tires, there is a method of reducing the hysteresis loss of vulcanized rubber, and as evaluation indices of such vulcanized rubber, rebound elasticity, tan δ, Goodrich heat generation, etc. at 50℃ to 80℃ are used. In other words, a rubber material having a large rebound elasticity or a small tan δ and Goodrich heat generation at the above temperature is desirable.

Natural rubber, polyisoprene rubber, or polybutadiene rubber are known as rubber materials with small hysteresis loss, but they have the problem of low wet road resistance. Therefore, conjugated diene polymers or copolymers such as styrene-butadiene rubber (hereinafter referred to as SBR) or butadiene rubber (hereinafter referred to as BR) have been manufactured by emulsion polymerization or solution polymerization and used as rubber for tires. Among these, the greatest advantage of solution polymerization over emulsion polymerization is that the vinyl structure content and styrene content, which determine the rubber properties, can be arbitrarily controlled, and the molecular weight and properties can be controlled by coupling or modification. Therefore, the structure of the finally manufactured SBR or BR is easy to change, and the movement of the chain ends can be reduced by bonding or modification of the chain ends, and the bonding strength with fillers such as silica or carbon black can be increased, so SBR manufactured by solution polymerization is widely used as a rubber material for tires.

When such solution-polymerized SBR is used as a rubber material for tires, the glass transition temperature of the rubber can be raised by increasing the vinyl content in the SBR, thereby controlling the tire's required physical properties such as driving resistance and braking power, and fuel consumption can be reduced by appropriately controlling the glass transition temperature. The solution-polymerized SBR is manufactured using an anionic polymerization initiator, and a technology is being used to introduce a functional group to the chain terminal of the formed polymer by bonding it using various denaturing agents or modifying it. For example, U.S. Patent No. 4,397,994 proposes a technology to bond an active anion at the chain terminal of a polymer obtained by polymerizing styrene-butadiene in a nonpolar solvent using a monofunctional initiator, alkyl lithium, using a bonding agent such as a tin compound.

Meanwhile, as a modifier for introducing a functional group to the chain terminal of a polymer, a technology for applying an aminoalkoxysilane modifier containing both an alkoxysilane group and an amine group in the molecule to maximize the dispersibility and reactivity of the filler is widely known. However, there is a problem that when the number of amine groups in the modifier increases, the solubility in the hydrocarbon solvent used in polymer production decreases, making it difficult for the modification reaction to easily occur.

US 4397994 A

The present invention has been made to solve the problems of the above-mentioned prior art, and aims to provide a modified conjugated diene polymer having a better affinity for a filler, which comprises a modified monomer-derived unit including an amine group within the polymer chain and at least one terminal, and a modified agent-derived functional group bonded to the terminal of the polymer chain to which the modified monomer-derived unit is bonded.

In addition, the present invention aims to provide a method for producing the above-mentioned modified conjugated diene polymer, which comprises the steps of producing an active polymer chain including a modified monomer-derived unit at one end by polymerizing in the presence of a polymerization initiator and a modified monomer, and capping the other end of the active polymer chain with the modified monomer before reaction with the modified agent.

In addition, the present invention provides a rubber composition comprising the modified conjugated diene polymer.

According to one embodiment of the present invention for solving the above problem, the present invention provides a modified conjugated diene polymer, which comprises a polymer chain including a repeating unit derived from a conjugated diene monomer; a modified monomer-derived unit represented by the following chemical formula 1; and a functional group derived from a modifier, wherein the modified monomer-derived unit is bonded within the polymer chain and at least one terminal, and the functional group derived from the modifier is bonded to the modified monomer-derived unit bonded to the terminal of the polymer chain:

[Chemical Formula 1]

In the above chemical formula 1,

R ₁ is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms,

R ₂ is a single bond or an alkylene group having 1 to 20 carbon atoms, which is unsubstituted or substituted with a substituent,

R ₃ and R ₄ are independently an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, or an aryl group having 6 to 30 carbon atoms, which is unsubstituted or substituted with a substituent,

The above substituent is at least one selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, and an aryl group having 6 to 20 carbon atoms.

In addition, the present invention comprises a step (S1) of polymerizing a first modified monomer and a conjugated diene monomer or a conjugated diene monomer and an aromatic vinyl monomer in the presence of a polymerization initiator in a carbon solvent to produce an active polymer chain including a modified monomer-derived unit; a step (S2) of adding a second modified monomer to the active polymer chain and reacting it to cap a terminal with the second modified monomer-derived unit to produce a capped polymer chain; and a step (S3) of adding a modifier to the capped polymer chain and reacting it, wherein the steps (S1); (S2); Step (S3) is performed continuously, the second modified monomer is added at a time point when the polymerization conversion of step (S1) is 90% or higher, and the modifier is added at a time point when the polymerization conversion of step (S2) is 90% or higher, and a method for producing the modified conjugated diene polymer is provided, wherein the first modified monomer and the second modified monomer are compounds represented by the following chemical formula 1.

In addition, the present invention provides a rubber composition comprising the modified conjugated diene polymer and a filler.

The modified conjugated diene polymer according to the present invention includes a functional group derived from a modifier, and separately from the functional group derived from the modifier, includes a unit derived from a modified monomer within the polymer chain and at least at one terminal, thereby having excellent affinity with a filler.

The method for producing a modified conjugated diene polymer according to the present invention includes a step of using a modified monomer containing an amine group to carry out a polymerization reaction during the polymerization reaction, and capping a polymer chain with the modified monomer before reaction with a modifier, thereby enabling introduction of an amine group into the polymer separately from the modifier, thereby resolving the difficulty of a modification reaction due to an amine group in the modifier, and consequently producing a highly modified modified conjugated diene polymer.

In addition, the rubber composition according to the present invention has excellent tensile properties and viscoelastic properties by including the above-mentioned modified conjugated diene polymer.

Hereinafter, the present invention will be described in more detail to help understand the present invention.

The terms or words used in the description and claims of the present invention should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical idea of the present invention, based on the principle that the inventor can appropriately define the concept of the term in order to explain his or her own invention in the best manner.

In the present invention, the term 'polymer chain' may mean that one or more monomers undergo a polymerization reaction and monomer-derived units are repeatedly connected.

In the present invention, the term 'substitution' may mean that a hydrogen of a functional group, an atomic group, or a compound is substituted with a specific substituent, and when a hydrogen of a functional group, an atomic group, or a compound is substituted with a specific substituent, one or two or more substituents may be present depending on the number of hydrogens present in the functional group, an atomic group, or a compound, and when multiple substituents are present, each of the substituents may be the same as or different from each other.

In the present invention, the term 'alkyl group' may mean a monovalent aliphatic saturated hydrocarbon, and may mean all of linear alkyl groups such as methyl, ethyl, propyl, and butyl; branched alkyl groups such as isopropyl, sec-butyl, tert-butyl, and neopentyl; and cyclic saturated hydrocarbons, or cyclic unsaturated hydrocarbons including one or more unsaturated bonds.

In the present invention, the term 'alkylene group' may mean a divalent aliphatic saturated hydrocarbon such as methylene, ethylene, propylene, and butylene.

In the present invention, the term 'cycloalkyl group' may mean a cyclic saturated hydrocarbon.

In the present invention, the term 'aryl group' may mean a cyclic aromatic hydrocarbon, and may also mean a monocyclic aromatic hydrocarbon in which one ring is formed, or a polycyclic aromatic hydrocarbon in which two or more rings are combined.

In the present invention, the term 'aralkyl group', also called aralkyl, may mean a combination of an alkyl group and an aryl group formed by replacing a hydrogen atom bonded to a carbon constituting the alkyl group with an aryl group.

In the present invention, the term 'single bond' may mean a single covalent bond itself that does not include a separate atom or molecular group.

In the present invention, the terms 'derived unit', 'derived repeating unit' and 'derived functional group' may mean a component, structure or the substance itself derived from a certain substance.

The present invention provides a modified conjugated diene polymer capable of providing a rubber composition having excellent compatibility with a filler and, as a result, excellent processability, tensile properties, and viscoelastic properties.

A modified conjugated diene polymer according to one embodiment of the present invention comprises: a polymer chain including a conjugated diene monomer-derived repeating unit; a modified monomer-derived unit represented by the following chemical formula 1; and a modifier-derived functional group, wherein the modified monomer-derived unit is bonded within the polymer chain and at least one terminal, and the modifier-derived functional group is bonded to the modified monomer-derived unit bonded to the terminal of the polymer chain.

[Chemical Formula 1]

In the above chemical formula 1,

R ₁ is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms,

R ₂ is a single bond or an alkylene group having 1 to 20 carbon atoms, which is unsubstituted or substituted with a substituent,

R ₃ and R ₄ are independently an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, or an aryl group having 6 to 30 carbon atoms, which is unsubstituted or substituted with a substituent,

The above substituent is at least one selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, and an aryl group having 6 to 20 carbon atoms.

According to one embodiment of the present invention, the modified conjugated diene polymer may be manufactured by a manufacturing method described below, which includes a step of reacting a modified monomer containing an amine group during a polymerization reaction and before a modification reaction through a reaction with a denaturant, and through this, a modified monomer-derived unit is bonded within a polymer chain including a conjugated diene monomer-derived repeating unit and at least one terminal, and a modified agent-derived functional group is bonded to the modified monomer-derived unit bonded to the terminal of the polymer chain, thereby becoming a highly modified copolymer.

The above modified monomer is a compound represented by chemical formula 1, wherein in chemical formula 1, R ₁ is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, R ₂ is a single bond or an unsubstituted alkylene group having 1 to 10 carbon atoms, R ₃ and R ₄ may each independently be an unsubstituted alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and more specifically, in chemical formula 1, R ₁ is a hydrogen atom, R ₂ is a single bond, and R ₃ and R ₄ may each independently be an unsubstituted alkyl group having 1 to 10 carbon atoms.

According to one embodiment of the present invention, the modified conjugated diene polymer may include a polymer chain including a conjugated diene monomer-derived repeating unit, a modified monomer-derived unit bonded to the polymer chain, and a modifier-derived functional group bonded to the modified monomer-derived unit, wherein the modified monomer-derived unit is bonded within the polymer chain and to at least one terminal of the polymer chain, and the modifier-derived functional group is bonded to the modified monomer-derived unit bonded to the terminal of the polymer chain, wherein the conjugated diene monomer-derived repeating unit may refer to a repeating unit formed when the conjugated diene monomer is polymerized, and the modifier-derived functional group and the modified monomer-derived unit may refer to a functional group derived from a modifier and a unit derived from a modified monomer, respectively.

In addition, according to another embodiment of the present invention, the modified conjugated diene polymer may be a copolymer including a conjugated diene monomer-derived repeating unit, an aromatic vinyl monomer-derived repeating unit, a modifying agent-derived functional group, and a modified monomer-derived unit, in which case the modified monomer-derived unit may be bonded within and at least at one terminal of a polymer chain including the conjugated diene monomer-derived repeating unit and the aromatic vinyl monomer-derived repeating unit, and the modifying agent-derived functional group may be bonded to the modified monomer-derived unit bonded to the terminal of the polymer chain.

That is, the modified conjugated diene polymer according to one embodiment of the present invention may include a unit derived from a modified monomer within and at least at one end of the polymer chain, and may include a unit derived from a modified monomer and a functional group derived from a modifier at at least one end of the polymer chain. Accordingly, the modified conjugated diene polymer according to one embodiment of the present invention may further include an amine group derived from a modified monomer separately from the functional group derived from the modifier.

According to one embodiment of the present invention, the conjugated diene monomer may be at least one 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).

The above aromatic vinyl monomer may be at least one selected from the group consisting of, for example, styrene, α-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-propylstyrene, 1-vinylnaphthalene, 4-cyclohexylstyrene, 4-(p-methylphenyl)styrene, 1-vinyl-5-hexylnaphthalene, 3-(2-pyrrolidino ethyl)styrene, 4-(2-pyrrolidino ethyl)styrene, and 3-(2-pyrrolidino-1-methyl ethyl)-α-methylstyrene.

As another example, the modified conjugated diene polymer may be a copolymer further including a repeating unit derived from a diene monomer having 1 to 10 carbon atoms together with the repeating unit derived from the conjugated diene monomer. The repeating unit derived from the diene monomer may be a repeating unit derived from a diene monomer different from the conjugated diene monomer, and the diene monomer different from the conjugated diene monomer may be, for example, 1,2-butadiene. When the modified conjugated diene polymer is a copolymer further including a diene monomer, the modified conjugated diene polymer may include a repeating unit derived from the diene monomer in an amount of from more than 0 wt% to 1 wt%, from more than 0 wt% to 0.1 wt%, from more than 0 wt% to 0.01 wt%, or from more than 0 wt% to 0.001 wt%, and has an effect of preventing gel formation within this range.

According to one embodiment of the present invention, the polymer chain may be a random copolymer chain, in which case there is an excellent effect of balance between each physical property. The random copolymer may mean that the repeating units forming the copolymer are arranged randomly.

According to one embodiment of the present invention, the modified conjugated diene polymer may have a number average molecular weight (Mn) of 1,000 g/mol to 2,000,000 g/mol, 10,000 g/mol to 1,000,000 g/mol, or 100,000 g/mol to 800,000 g/mol, a weight average molecular weight (Mw) of 1,000 g/mol to 3,000,000 g/mol, 10,000 g/mol to 2,000,000 g/mol, or 100,000 g/mol to 2,000,000 g/mol, and a peak average molecular weight (Mp) of 1,000 g/mol to 3,000,000 g/mol, 10,000 g/mol to 2,000,000 g/mol. g/mol, or 100,000 g/mol to 2,000,000 g/mol. Within this range, excellent cloud resistance and wet road resistance are achieved.

As another example, the modified conjugated diene polymer may have a molecular weight distribution (PDI; MWD; Mw/Mn) of 1.0 or more and less than 1.7, or 1.1 or more and less than 1.7, or 1.2 or more and 1.6 or less, and within this range, the tensile properties and viscoelastic properties are excellent, and there is an excellent effect of a balance between each property.

As another example, the modified conjugated diene polymer may have a Mooney relaxation rate measured at 100°C of 0.7 or more, 0.7 or more and 3.0 or less, 0.7 or more and 2.5 or less, or 0.7 or more and 2.0 or less.

Here, the Mooney relaxation rate indicates the change in stress that appears in response to the same amount of strain, and may be measured using a Mooney viscometer. Specifically, the Mooney relaxation rate was obtained by using a Large Rotor of Monsanto MV2000E, leaving the polymer at room temperature (23±5℃) for more than 30 minutes under the conditions of 100℃ and a rotor speed of 2±0.02 rpm, then sampling 27±3 g and filling it into the die cavity, operating the platen to apply torque, measuring Mooney viscosity, and then measuring the slope value of the Mooney viscosity change that appears when the torque is released.

Meanwhile, the Mooney relaxation ratio can be used as an indicator of the branching structure of the polymer. For example, when comparing polymers with the same Mooney viscosity, the more branches there are, the smaller the Mooney relaxation ratio becomes, so it can be used as an indicator of the degree of branching.

In addition, the modified conjugated diene polymer may have a Mooney viscosity of 30 or more, 40 to 150, or 40 to 140 at 100°C, and has excellent processability and productivity within this range.

Here, the Mooney viscosity may be measured using a Mooney viscometer. Specifically, it was measured using a Large Rotor of Monsanto MV2000E, under the conditions of 100℃ and a Rotor Speed of 2±0.02 rpm, after leaving the polymer at room temperature (23±5℃) for more than 30 minutes, 27±3 g was collected and filled into the die cavity, and the platen was operated to apply torque.

As another example, the modified conjugated diene polymer may have an N content of 200 ppm or more, 200 ppm to 10,000 ppm, or 100 ppm to 5,000 ppm based on the total weight, and within this range, the rubber composition including the modified conjugated diene polymer has excellent mechanical properties such as tensile properties and viscoelastic properties. The N content may refer to the content of N atoms present in the modified conjugated diene polymer, and in this case, the N atoms may be derived from a modified monomer and a modifier.

The above N content may be measured, for example, by the NSX analysis method, and the NSX analysis method may be measured using a trace nitrogen quantitative analyzer (NSX-2100H).

For example, in case of using the above trace nitrogen quantitative analyzer, the trace nitrogen quantitative analyzer (Auto sampler, Horizontal furnace, PMT & Nitrogen detector) was turned on and the carrier gas flow rates were set to 250 ml/min for Ar, 350 ml/min for _O2 , and 300 ml/min for ozonizer, and the heater was set to 800℃, and then the analyzer was stabilized for about 3 hours. After the analyzer was stabilized, a calibration curve was created with a Nitrogen standard (AccuStandard S-22750-01-5 ml) for a calibration curve range of 5 ppm, 10 ppm, 50 ppm, 100 ppm, and 500 ppm, and the Area corresponding to each concentration was obtained, and then a straight line was created using the ratio of the Area to the concentration. Thereafter, a ceramic boat containing 20 mg of the sample was placed on the Auto sampler of the analyzer and measured to obtain the area. The N content was calculated using the area of the obtained sample and the above calibration curve.

At this time, the sample used in the above NSX analysis method may be a modified conjugated diene polymer sample that has been stirred in hot water heated with steam to remove the solvent, and may be a sample from which residual monomer and residual denaturant have been removed. In addition, if oil is added to the above sample, it may be a sample after the oil has been extracted (removed).

In addition, the modified conjugated diene polymer may have a vinyl content of 5 wt% or more, 10 wt% or more, or from 10 wt% to 60 wt%. Here, the vinyl content may mean the content of a 1,2-added, but not a 1,4-added, conjugated diene monomer with respect to 100 wt% of the conjugated diene copolymer composed of a monomer having a vinyl group and an aromatic vinyl monomer.

In addition, the modifier according to the present invention may be a modifier for modifying at least one terminal of a polymer chain including a repeating unit derived from a conjugated diene monomer, and a specific example thereof may be a silica affinity modifier. The silica affinity modifier may refer to a modifier containing a silica affinity functional group in a compound used as a modifier, and the silica affinity functional group may refer to a functional group having excellent affinity with a filler, particularly a silica-based filler, such that interaction between the silica-based filler and the functional group derived from the modifier is possible.

Specifically, according to one embodiment of the present invention, the modifier may be at least one selected from compounds represented by the following chemical formula 2 or chemical formula 3.

[Chemical formula 2]

In the above chemical formula 2,

R _a1 and R _a4 are each independently a single bond or an alkylene group having 1 to 10 carbon atoms, R _a2 and R _a3 are each independently an alkyl group having 1 to 10 carbon atoms, R _a5 is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a divalent, trivalent or tetravalent alkylsilyl group substituted with an alkyl group having 1 to 10 carbon atoms, n ₁ is an integer from 1 to 3, n ₂ is an integer from 0 to 2,

[Chemical Formula 3]

In the above chemical formula 3, A ₁ and A ₂ are each independently an alkylene group having 1 to 20 carbon atoms, R _b1 to R _b4 are each independently an alkyl group having 1 to 20 carbon atoms, and L ₁ to L ₄ are each independently a divalent, trivalent or tetravalent alkylsilyl group substituted with an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms or an alkyl group having 1 to 10 carbon atoms.

Specifically, the modifier according to one embodiment of the present invention may be a compound represented by Chemical Formula 2, wherein R _a1 and R _a4 in Chemical Formula 2 are each independently a single bond or an alkylene group having 1 to 5 carbon atoms, R _a2 and R _a3 are each independently an alkyl group having 1 to 5 carbon atoms, Ra ₅ may be a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a tetravalent alkylsilyl group substituted with an alkyl group having 1 to 5 carbon atoms, n ₁ may be an integer of 2 or 3, and n ₂ may be an integer of 0 to 2.

More specifically, the compound represented by the chemical formula 2 is N,N-bis(3-(dimethoxy(methyl)silyl)propyl)-methyl-1-amine, N,N-bis(3-(diethoxy(methyl)silyl)propyl)-methyl-1-amine, N,N-bis(3-(diethoxy(methyl)silyl)propyl)-methyl-1-amine, N,N-bis(3-(trimethoxysilyl)propyl)-methyl-1-amine, N,N-bis(3-(triethoxysilyl)propyl)-methyl-1-amine, It may be at least one selected from the group consisting of N,N-diethyl-3-(trimethoxysilyl)propan-1-amine, N,N-diethyl-3-(triethoxysilyl)propan-1-amine, tri(trimethoxysilyl)amine, tri-(3-(trimethoxysilyl)propyl)amine, and N,N-bis(3-(diethoxy(methyl)silyl)propyl)-1,1,1-trimethlysilanamine.

In addition, the modifier according to another embodiment of the present invention may be a compound represented by the chemical formula 3, wherein in the chemical formula 3, A ₁ and A ₂ are each independently an alkylene group having 1 to 10 carbon atoms, R _b1 to R _b4 are each independently an alkyl group having 1 to 10 carbon atoms, and L ₁ to L ₄ may each independently be a tetravalent alkylsilyl group substituted with an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an alkyl group having 1 to 5 carbon atoms.

More specifically, the compound represented by the chemical formula 3 is 3,3'-(1,1,3,3-tetramethoxydisiloxane-1,3-diyl)bis(N,N-dimethylpropan-1-amine), 3,3'-(1,1,3,3-tetraethoxydisiloxane-1,3-diyl)bis(N,N-dimethylpropan-1-amine), 3,3'-(1,1,3,3-tetrapropoxydisiloxane-1,3-diyl)bis(N,N-dimethylpropan-1-amine)(3,3'-(1,1,3,3-tetrapropoxydisiloxane-1,3-diyl)bis(N,N-dimethylpropan-1-amine), 3,3'-(1,1,3,3-tetramethoxydisiloxane-1,3-diyl)bis(N,N-diethylpropan-1-amine)(3,3'-(1,1,3,3-tetramethoxydisiloxane-1,3-diyl)bis(N,N-diethylpropan-1-amine), 3,3'-(1,1,3,3-tetramethoxydisiloxane-1,3-diyl)bis(N,N-dipropylpropan-1-amine)(3,3'-(1,1,3,3-tetramethoxydisiloxane-1,3-diyl)bis(N,Ndimpropylpropan-1-amine), 3,3'-(1,1,3,3-tetraethoxydisiloxane-1,3-diyl)bis(N,N-diethylpropan-1-amine)(3,3'-(1,1,3,3-tetraethoxydisiloxane-1,3-diyl)bis(N,N-diethylpropan-1-amine), 3,3'-(1,1,3,3-tetrapropoxydisiloxane-1,3-diyl)bis(N,N-diethylpropan-1-amine)(3,3'-(1,1,3,3-tetrapropoxydisiloxane-1,3-diyl)bis(N,N-diethylpropan-1-amine), 3,3'-(1,1,3,3-tetraethoxydisiloxane-1,3-diyl)bis(N,N-dipropylpropan-1-amine), 3,3'-(1,1,3,3-tetrapropoxydisiloxane-1,3-diyl)bis(N,N-dipropylpropan-1-amine)(3,3'-(1,1,3,3-tetrapropoxydisiloxane-1,3-diyl)bis(N,N-dipropylpropan-1-amine), 3,3'-(1,1,3,3-tetramethoxydisiloxane-1,3-diyl)bis(N,N-diethylmethan-1-amine), 3,3'-(1,1,3,3-tetraethoxydisiloxane-1,3-diyl)bis(N,N-diethylmethan-1-amine)(3,3'-(1,1,3,3-tetraethoxydisiloxane-1,3-diyl)bis(N,N-diethylmethan-1-amine), 3,3'-(1,1,3,3-tetrapropoxydisiloxane-1,3-diyl)bis(N,N-diethylmethan-1-amine), 3,3'-(1,1,3,3-tetramethoxydisiloxane-1,3-diyl)bis(N,N-dimethylmethan-1-amine)(3,3'-(1,1,3,3-tetramethoxydisiloxane-1,3-diyl)bis(N,N-dimethylmethan-1-amine), 3,3'-(1,1,3,3-tetramethoxydisiloxane-1,3-diyl)bis(N,N-dipropylmethan-1-amine)(3,3'-(1,1,3,3-tetramethoxydisiloxane-1,3-diyl)bis(N,N-dipropylmethan-1-amine),3,3'-(1,1,3,3-tetrapropoxydisiloxane-1,3-diyl)bis(N,N-dimethylmethan-1-amine), 3,3'-(1,1,3,3-tetrapropoxydisiloxane-1,3-diyl)bis(N,N-dipropylmethan-1-amine)(3,3'-(1,1,3,3-tetrapropoxydisiloxane-1,3-diyl)bis(N,N-dipropylmethan-1-amine), 3,3'-(1,1,3,3-tetraethoxydisiloxane-1,3-diyl)bis(N,N-dimethylmethan-1-amine), 3,3'-(1,1,3,3-tetraethoxydisiloxane-1,3-diyl)bis(N,N-dipropylmethan-1-amine)(3,3'-(1,1,3,3-tetraethoxydisiloxane-1,3-diyl)bis(N,N-dipropylmethan-1-amine), N,N'-((1,1,3,3-tetramethoxydisiloxane-1,3-diyl)bis(propan-3,1-diyl))bis(1,1,1-trimethyl-N-(trimethylsilyl)silanamine), N,N'-((1,1,3,3-tetraethoxydisiloxane-1,3-diyl)bis(propan-3,1-diyl))bis(1,1,1-trimethyl-N-(trimethylsilyl)silanamine), N,N'-((1,1,3,3-tetrapropoxydisiloxane-1,3-diyl)bis(propan-3,1-diyl))bis(1,1,1-trimethyl-N-(trimethylsilyl)silanamine), N,N'-((1,1,3,3-tetramethoxydisiloxane-1,3-diyl)bis(propan-3,1-diyl))bis(1,1,1-trimethyl-N-phenylsilanamine), N,N'-((1,1,3,3-tetraethoxydisiloxane-1,3-diyl)bis(propan-3,1-diyl))bis(1,1,1-trimethyl-N-phenylsilanamine), and N,N'-((1,1,3,3-tetrapropoxydisiloxane-1,3-diyl)bis(propan-3,1-diyl))bis(1,1,1-trimethyl-N-phenylsilanamine). It may be at least one selected from the group consisting of tetrapropoxydisiloxane-1,3-diyl)bis(propan-3,1-diyl))bis(1,1,1-trimethyl-N-phenylsilanamine).

A modified conjugated diene polymer according to one embodiment of the present invention contains a large number of amine groups having excellent affinity for a filler within the polymer molecule, so that the affinity for the filler can be further improved, and thus the processability, tensile properties, and viscoelastic properties of a rubber composition including the same can be well-balanced and excellent.

In addition, the present invention provides a method for producing the modified conjugated diene polymer.

According to one embodiment of the present invention, a method for producing a modified conjugated diene polymer comprises the steps of (S1) polymerizing a first modified monomer and a conjugated diene monomer or a conjugated diene monomer and an aromatic vinyl monomer in a carbon solvent in the presence of a polymerization initiator to produce an active polymer chain including a modified monomer-derived unit; (S2) adding a second modified monomer to the active polymer chain and reacting it to cap a terminal with the second modified monomer-derived unit to produce a capped polymer chain; and (S3) adding a modifier to the capped polymer chain and reacting it, wherein the steps (S1); (S2); Step (S3) is performed continuously, the second modified monomer is added at a time point when the polymerization conversion of step (S1) is 90% or higher, and the denaturant is added at a time point when the polymerization conversion of step (S2) is 90% or higher, and the first modified monomer and the second modified monomer are characterized in that they are compounds represented by the following chemical formula 1.

[Chemical Formula 1]

In the above chemical formula 1, R ₁ to R ₄ are as defined above, and the modifier is as described above.

In the above first modified monomer and second modified monomer, ‘first’ and ‘second’ are used to distinguish the time points of input of the modified monomers in the manufacturing method, and the first modified monomer and the second modified monomer refer to the same modified monomer.

The above first modified monomer and second modified monomer may each be used in an amount of 0.1 to 50 mol per 1 mol of the polymerization initiator.

The hydrocarbon solvent is not particularly limited, but may be at least one selected from the group consisting of n-pentane, n-hexane, n-heptane, isooctane, cyclohexane, toluene, benzene, and xylene.

The polymerization initiator is not particularly limited, but may be at least one selected from the group consisting of methyllithium, ethyllithium, propyllithium, isopropyllithium, 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, naphthylsodium, naphthylpotassium, lithium alkoxide, sodium alkoxide, potassium alkoxide, lithium sulfonate, sodium sulfonate, potassium sulfonate, lithium amide, sodium amide, potassium amide, and lithium isopropylamide.

According to one embodiment of the present invention, the polymerization initiator may be used in an amount of 0.01 mmol to 10 mmol, 0.05 mmol to 5 mmol, 0.1 mmol to 2 mmol, 0.1 mmol to 1 mmol, or 0.15 to 0.8 mmol based on 100 g of the total monomer. Here, the total 100 g of the monomer may represent the total amount of the conjugated diene monomer or the conjugated diene monomer and the aromatic vinyl monomer.

The polymerization of the step (S1) may be, for example, anionic polymerization, and as a specific example, may be a living anionic polymerization having an anion active site at the polymerization terminal by a growth polymerization reaction by anion. In addition, the polymerization of the step (S1) may be temperature-elevated polymerization, isothermal polymerization, or isothermal polymerization (adiabatic polymerization), and the isothermal polymerization may mean a polymerization method including a step of polymerizing by the heat of reaction itself without arbitrarily applying heat after introducing a polymerization initiator, the temperature-elevated polymerization may mean a polymerization method of increasing the temperature by arbitrarily applying heat after introducing the polymerization initiator, and the isothermal polymerization may mean a polymerization method of maintaining the temperature of the polymerization product constant by applying heat to increase the heat or removing heat after introducing the polymerization initiator.

In addition, according to one embodiment of the present invention, the polymerization in step (S1) may be carried out by further including a diene compound having 1 to 10 carbon atoms in addition to the conjugated diene monomer, and in this case, there is an effect of preventing a gel from being formed on the wall of the reactor during long-term operation. An example of the diene compound may be 1,2-butadiene.

The polymerization in the above step (S1) can be carried out at a temperature range of, for example, 80°C or less, -20°C to 80°C, 0°C to 80°C, 0°C to 70°C, or 10°C to 70°C, and within this range, the molecular weight distribution of the polymer is narrowly controlled, thereby having an excellent effect of improving physical properties.

The active polymer chain manufactured by the above step (S1) may include the modified monomer-derived unit, and as another example, the active polymer chain may be a polymer including the modified monomer-derived unit at one terminal and a polymer anion and an organic metal cation bonded at the other terminal.

Meanwhile, the polymerization of the step (S1) may be carried out including a polar additive, and the polar additive may be added in a proportion of 0.001 g to 50 g, 0.001 g to 10 g, or 0.005 g to 0.1 g based on 100 g of the total monomer. In another example, the polar additive may be added in a proportion of 0.001 g to 10 g, 0.005 g to 5 g, or 0.005 g to 4 g based on 1 mmol of the total polymerization initiator.

The polar additive may be, for example, at least one selected from the group consisting of tetrahydrofuran, 2,2-di(2-tetrahydrofuryl)propane, diethyl ether, cyclopentyl ether, dipropyl ether, ethylene methyl ether, ethylene dimethyl ether, diethyl glycol, dimethyl ether, tert-butoxyethoxyethane, bis(3-dimethylaminoethyl)ether, (dimethylaminoethyl)ethyl ether, trimethylamine, triethylamine, tripropylamine, N,N,N',N'-tetramethylethylenediamine, sodium mentholate, and 2-ethyl tetrahydrofurfuryl ether, and preferably 2,2-di(2-tetrahydrofuryl)propane, triethylamine, tetramethylethylenediamine, sodium mentholate, or 2-ethyl tetrahydrofurfuryl. It may be ether (2-ethyl tetrahydrofurfuryl ether), and when the polar additive is included, it has the effect of inducing easy formation of a random copolymer by compensating for the difference in reaction speed between a conjugated diene monomer and an aromatic vinyl monomer when copolymerizing them.

In addition, the step (S2) is a step for producing a capped active polymer chain by reacting an active polymer chain including a first modified monomer-derived unit with a second modified monomer to cap the end of the polymer chain with a second modified monomer-derived unit, and adding and reacting a second modified monomer to the active polymer chain to produce an active polymer chain in which the other end of the active polymer chain is capped with a second modified monomer-derived unit.

The above step (S3) is a step for producing a modified conjugated diene polymer by reacting the capped active polymer chain with a modifier, wherein the reaction may be a modification or coupling reaction, and at this time, the modifier may be used in an amount of 0.01 mmol to 10 mmol based on 100 g of the total monomer. As another example, the modifier may be used in a molar ratio of 1:0.1 to 10, 1:0.1 to 5, or 1:0.1 to 1:3 based on 1 mol of the polymerization initiator of the above step (S1).

In addition, according to one embodiment of the present invention, the method for producing the modified conjugated diene polymer may be performed by a continuous polymerization method in a plurality of reactors including two or more polymerization reactors and modification reactors. As a specific example, the steps (S1), (S2) a, and (S3) may be performed continuously, the modified monomer may be added at a time when the polymerization conversion of the step (S1) is 90% or higher, and the modification agent may be added at a time when the polymerization conversion of the step (S2) is 90% or higher.

Meanwhile, the number of the polymerization reactors can be flexibly determined according to the reaction conditions and environment. The continuous polymerization method may mean a reaction process in which reactants are continuously supplied to the reactor and the generated reaction products are continuously discharged. In the case of the continuous polymerization method, productivity and processability are excellent, and the uniformity of the polymer produced is excellent.

At this time, the polymerization conversion rate can be controlled according to the reaction temperature, reactor residence time, etc.

The above polymerization conversion rate can be determined, for example, by measuring the solid concentration of a polymer solution phase containing a polymer during polymerization of the polymer, and as a specific example, in order to secure the polymer solution, a cylindrical container is mounted at the outlet of each polymerization reactor, a certain amount of the polymer solution is filled into the cylindrical container, the cylindrical container is separated from the reactor, the weight (A) of the cylinder filled with the polymer solution is measured, the polymer solution filled in the cylindrical container is transferred to an aluminum container, for example, an aluminum dish, the weight (B) of the cylindrical container from which the polymer solution has been removed is measured, the aluminum container containing the polymer solution is dried in an oven at 140°C for 30 minutes, the weight (C) of the dried polymer is measured, and the result may be calculated according to the following mathematical formula 1.

[Mathematical formula 1]

In addition, the present invention provides a rubber composition comprising the above-mentioned modified conjugated diene polymer.

The above rubber composition may contain the modified conjugated diene polymer in an amount of 10 wt% or more, 10 wt% to 100 wt%, or 20 wt% to 90 wt%, and within this range, the composition has excellent mechanical properties such as tensile strength and wear resistance, and excellent balance between each property.

In addition, the rubber composition may further include other rubber components as needed in addition to the modified conjugated diene polymer, and at this time, the rubber component may be included in an amount of 90 wt% or less based on the total weight of the rubber composition. As a specific example, the other rubber component may be included in an amount of 1 to 900 wt% based on 100 wt% of the modified conjugated diene polymer.

The above rubber component may be, for example, natural rubber or synthetic rubber, and specific examples thereof include natural rubber (NR) including cis-1,4-polyisoprene; modified natural rubber such as epoxidized natural rubber (ENR), deproteinized natural rubber (DPNR), and hydrogenated natural rubber, which are modified or refined from the above general natural rubber; It can be a synthetic rubber such as styrene-butadiene copolymer (SBR), polybutadiene (BR), polyisoprene (IR), butyl rubber (IIR), ethylene-propylene copolymer, polyisobutylene-co-isoprene, 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, halogenated butyl rubber, and any one of these or a mixture of two or more thereof can be used.

The above rubber composition may contain, for example, 0.1 to 200 parts by weight, or 10 to 120 parts by weight, of a filler based on 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, or colloidal silica, and preferably wet silica, which has the most excellent effect of improving fracture characteristics and achieving wet grip properties. In addition, the rubber composition may further contain a carbon black-based filler, if necessary.

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 generation, and 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, 2-Triethoxysilylethyl-N,N-dimethylthiocarbamoyltetrasulfide, 3-Trimethoxysilylpropylbenzothiazolyltetrasulfide, 3-Triethoxysilylpropylbenzolyltetrasulfide, 3-Triethoxysilylpropylmethacrylate monosulfide, 3-Trimethoxysilylpropylmethacrylate monosulfide, bis(3-diethoxymethylsilylpropyl)tetrasulfide, 3-mercaptopropyldimethoxymethylsilane, dimethoxymethylsilylpropyl-N,N-dimethylthiocarbamoyltetrasulfide, or dimethoxymethylsilylpropylbenzothiazolyltetrasulfide, and the like, and any one or a mixture of two or more of these may be used. Preferably, considering the effect of improving reinforcing properties, it may be bis(3-triethoxysilylpropyl)polysulfide or 3-trimethoxysilylpropylbenzothiazyl tetrasulfide.

In addition, since the rubber composition according to one embodiment of the present invention uses a modified conjugated diene polymer having a functional group having high affinity for silica introduced into an active site as a rubber component, the amount of the silane coupling agent can be reduced compared to the usual case, and accordingly, the silane coupling agent can be used in an amount of 1 to 20 parts by weight, or 5 to 15 parts by weight, based on 100 parts by weight of silica, and within this range, the effect as a coupling agent is sufficiently exhibited while also having the effect of preventing gelation of the rubber component.

The rubber composition according to one embodiment of the present invention may be sulfur crosslinkable and may further include a vulcanizing agent. The vulcanizing agent may be specifically sulfur powder and may be included in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the rubber component, and within this range, the vulcanized rubber composition has the effect of securing the necessary elastic modulus and strength while exhibiting excellent fuel efficiency.

The rubber composition according to one embodiment of the present invention may further include, in addition to the above-described components, various additives commonly used in the rubber industry, specifically, a vulcanization accelerator, a process oil, an antioxidant, a plasticizer, an anti-aging agent, a scorch inhibitor, zinc white, stearic acid, a thermosetting resin, or a thermoplastic resin.

The above-mentioned vulcanization accelerator may be, for example, a thiazole-based compound such as M(2-mercaptobenzothiazole), DM(dibenzothiazyl disulfide), CZ(N-cyclohexyl-2-benzothiazyl sulfenamide), or a guanidine-based compound such as DPG (diphenyl guanidine), and may be included in an amount of 0.1 to 5 parts by weight per 100 parts by weight of the rubber component.

The above process oil acts as a softener in the rubber composition, and may be, for example, a paraffinic, naphthenic, or aromatic compound. When considering tensile strength and wear resistance, an aromatic process oil may be used, and when considering hysteresis loss and low-temperature characteristics, a naphthenic or paraffinic process oil may be used. The above process oil may be included in an amount of, for example, 100 parts by weight or less with respect to 100 parts by weight of the rubber component, and within this range, there is an effect of preventing a decrease in the tensile strength and low heat generation (low fuel consumption) of the vulcanized rubber.

The antioxidant may be, for example, 2,6-di-t-butylparacresol, dibutylhydroxytoluenyl, 2,6-bis((dodecylthio)methyl)-4-nonylphenol or 2-methyl-4,6-bis((octylthio)methyl)phenol, and may be used in an amount of 0.1 to 6 parts by weight per 100 parts by weight of the rubber component.

The above-mentioned anti-aging agent may be, for example, 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.

The rubber composition according to one embodiment of the present invention can be obtained by mixing using a mixer such as a Banbury mixer, a roll mixer, or an internal mixer according to the above compounding prescription, and a rubber composition having low heat generation and excellent wear resistance can be obtained by a vulcanization process after molding processing.

Accordingly, the rubber composition can be useful in the manufacture of various components of a tire, such as a tire tread, undertread, sidewall, carcass coating rubber, belt coating rubber, bead filler, squeegee, or bead coating rubber, or various industrial rubber products, such as an anti-vibration rubber, belt conveyor, and hose.

In addition, the present invention provides a tire manufactured using the rubber composition.

The above tire may include a tire or tire tread.

Hereinafter, the present invention will be described in detail by way of examples in order to specifically explain the present invention. However, the examples according to the present invention may be modified in various different forms, and the scope of the present invention should not be construed as being limited to the examples described below. The examples of the present invention are provided in order to more completely explain the present invention to a person having average knowledge in the art.

Manufacturing example 1

A 2 L round-bottom flask was charged with 0.51 mol of 4-methyl benzaldehyde and dimethylformamide, and after dissolving the 4-methyl benzaldehyde, 240 g (1.73 mol) of potassium carbonate was added and stirred at 80°C for 1 hour. Then, 0.62 mol of N-chloro-N,N-methylmethanamine hydrochloride was slowly added dropwise, and the mixture was reacted at the same temperature for 15 hours. After completion of the reaction, the solid was removed using a filter, and ethyl acetate was added, followed by washing several times with a saturated NaCl aqueous solution. Thereafter, the organic layer was dried over anhydrous magnesium sulfate, the solid was removed using a filter, and the organic solvent was removed under reduced pressure to prepare 4-(dimethylamino)benzaldehyde.

After that, 300 g (0.84 mol) of methyl triphenylphosphonium bromide and tetrahydrofuran (THF) were added, and 190 g (1.69 mol) of porassium t-butoxide was added dropwise in an ice bath. The mixture was stirred at room temperature for 30 minutes, and 0.67 mol of the 4-(dimethylamino)benzaldehyde prepared above was dissolved in THF and slowly added dropwise, followed by reaction at room temperature for 3 hours. After completion of the reaction, the THF was distilled off under reduced pressure, water was added, and extraction was performed with methylene chloride, and the organic layer was dried over anhydrous magnesium sulfate and the solid was removed using a filter. The organic solvent was removed under reduced pressure, and 4-(dimethylamino)styrene (N,N-dimethyl-4-vinylaniline) was prepared.

Manufacturing example 2

(3-Chloropropyl)dimethoxymethylsilane (CAS No. 18171-19-2@Sigma-Aldrich, 1.83 g, 10 mmol) and diethylamine (0.8 g, 11 mmol) were completely dissolved in 100 ml of toluene at room temperature (23°C±3°C) by stirring, and then refluxed at 110°C for 2 hours to prepare 3-(dimethoxy(methyl)silyl)-N,N-diethylpropane-1-amine (yield: 2.5 g, >98%).

Manufacturing example 3

33.9 g (0.2 mol) of diallyl trimethylsilylamine and 0.26 g of a toluene solution of a platinum-1,3-divinyl-1,1,3,3-tetramethyl disiloxane complex (platinum content 3 mass%) were added, and heated to 70°C. After the temperature inside the reactor became stable, 53.7 g (0.4 mol) of methyldiethoxysilane was added dropwise over 4 hours, and the mixture was reacted at the above temperature for 1 hour, thereby producing 58.1 g of N,N-bis(3-(diethoxy(methyl)silyl)propyl)-1,1,1-trimethylsilamine.

Manufacturing example 4

3,3'-(1,1,3,3-tetramethoxydisiloxane-1,3-diyl)bis(propan-1-amine)(CAS No. 76712-65-7@LookChem, 3.13 g, 10 mmol) was completely dissolved in 100 ml of toluene at room temperature (23℃±3℃) by stirring, and then reacted with trimethylsilyl chloride (1.14 g, 10.5 mmol) in the presence of triethylamine (1.11 g, 11 mmol) as a base at 40℃ for 2 hours to obtain N,N'-(1,1,3,3-tetramethoxydisiloxane-1,3-diyl)bis(propan-3,1-diyl))bis(1,1,1-trimethylsilyl)silanamine (N,N’-(1,1,3,3-tetramethoxydisiloxane-1,3-diyl)bis(propane-3,1-diyl))bis(1,1,1-trimethyl-N-(trimethylsilyl)silanamine)) was prepared (yield: 5.6 g, >98%).

Example 1

In the first reactor of the continuous reactor having three reactors connected in series, a styrene solution having 60 wt% of styrene dissolved in n-hexane was supplied at 0.375 kg/h, a 1,3-butadiene solution having 60 wt% of 1,3-butadiene dissolved in n-hexane was supplied at 1.4 kg/h, a modified monomer solution having 4 wt% of 4-(dimethylamino)styrene prepared in Preparation 1 as a modified monomer was supplied at 31.8 g/h, n-hexane was supplied at 5.1 kg/h, a solution having 1.2 wt% of 2,2-(di-2(tetrahydrofuryl)propane as a polar additive was supplied at 100.0 g/h, and a n-butyllithium solution having 1.1 wt% of n-butyllithium was supplied at 39.8 g/h. At this time, the temperature of the first reactor was maintained at 50℃, and when the polymerization conversion rate reached 100%, the polymer was transferred from the first reactor to the second reactor through the transfer pipe.

Next, a modified monomer solution in which the modified monomer was dissolved in n-hexane at 4 wt% was injected into the second reactor at a rate of 31.8 g/h. At this time, the temperature of the second reactor was maintained at 50°C, and when the polymerization conversion rate reached 100%, the polymer was transferred from the second reactor to the third reactor through a transfer pipe.

The polymer was transferred from the second reactor to the third reactor, and a solution containing 2 wt% of 3-(dimethoxy(methyl)silyl)-N,N-diethylpropane-1-amine, prepared in Manufacturing Example 2 as a modifier, was introduced into the third reactor at a rate of 100.0 g/h. The temperature of the third reactor was maintained at 65°C.

After this, a solution of IR1520 (BASF) dissolved at 30 wt% as an antioxidant was injected at a rate of 17 g/h into the polymerization solution discharged from the third reactor and stirred. The resulting polymer was placed in hot water heated by steam and stirred to remove the solvent, thereby producing a modified conjugated diene polymer.

Example 2

In Example 1, a solution containing 20 wt% of N,N-bis(3-(diethoxy(methyl)silyl)propyl)-1,1,1-trimethylsilamine, prepared in Preparation Example 3 as a modifier, was introduced into the third reactor at a rate of 64.0 g/h, except that the same procedure as in Example 1 was repeated to prepare a modified styrene-butadiene copolymer.

Example 3

In Example 1, a solution containing 20 wt% of N,N’-(1,1,3,3-tetramethoxydisiloxane-1,3-diyl)bis(propane-3,1-diyl))bis(1,1,1-trimethylsilyl)silanamine (N,N’-(1,1,3,3-tetramethoxydisiloxane-1,3-diyl)bis(propane-3,1-diyl))bis(1,1,1-trimethyl-N-(trimethylsilyl)silanamine)) prepared in Preparation Example 4 as a modifier was introduced into the third reactor at a rate of 64.0 g/h, except that the same procedure as in Example 1 was repeated to prepare a modified styrene-butadiene copolymer.

Comparative Example 1

In Example 1, a modified conjugated diene polymer was manufactured in the same manner as in Example 1, except that no modified monomer was used.

Comparative Example 2

In Example 1, a modified conjugated diene polymer was manufactured in the same manner as in Example 1, except that a 1,3-butadiene solution in which 60 wt% of 1,3-butadiene was dissolved in n-hexane was injected at a rate of 2.96 kg/h instead of the modified monomer solution into the second reactor.

Comparative Example 3

In Example 1, a modified conjugated diene polymer was manufactured in the same manner as in Example 1, except that the modified monomer solution was not added to the first reactor.

For reference

In Example 1, a modified conjugated diene polymer was manufactured in the same manner as in Example 1, except that 0.410 kg/h of a 1,3-butadiene solution in which 60 wt% of 1,3-butadiene was dissolved in n-hexane together with a modified monomer solution was injected into the second reactor.

Experimental Example 1

For each modified or unmodified conjugated diene polymer manufactured in the above examples and comparative examples, the styrene unit content and vinyl content in the polymer, as well as the weight average molecular weight (Mw, X10 ³ g/mol), number average molecular weight (Mn, X10 ³ g/mol), molecular weight distribution (PDI, MWD), and Mooney viscosity (MV) were measured. The results are shown in Table 1 below.

1) Styrene units and vinyl content (weight %)

The styrene unit (SM) and vinyl content in each of the above polymers were measured and analyzed using a Varian VNMRS 500 MHz NMR.

In the NMR measurement, 1,1,2,2-tetrachloroethane was used as the solvent, and the solvent peak was calculated as 5.97 ppm. 7.2–6.9 ppm was the peak of random styrene, 6.9–6.2 ppm was the peak of block styrene, 5.8–5.1 ppm was the peak of 1,4-vinyl, and 5.1–4.5 ppm was the peak of 1,2-vinyl, and thus the styrene unit and vinyl content were calculated.

2) Weight average molecular weight (Mw, X10 ³ g/mol), number average molecular weight (Mn, X10 ³ g/mol), molecular weight distribution (PDI, MWD)

The weight average molecular weight (Mw) and number average molecular weight (Mn) were measured through GPC (Gel permeation chromatography) analysis, and a molecular weight distribution curve was obtained. In addition, the molecular weight distribution (PDI, MWD, Mw/Mn) was obtained by calculation from each measured molecular weight. Specifically, the GPC was performed by combining two PLgel Olexis (Polymer Laboratories) columns and one PLgel mixed-C (Polymer Laboratories) column, and PS (polystyrene) was used as the GPC standard material when calculating the molecular weight. The GPC measurement solvent was prepared by mixing 2 wt% of an amine compound into tetrahydrofuran.

3) Muni viscosity and Muni relaxation rate

The above Mooney viscosity (MV, (ML1+4, @100℃) MU) was measured using MV-2000 (ALPHA Technologies) at 100℃, Rotor Speed 2±0.02 rpm, Large Rotor. The sample used was left at room temperature (23±3℃) for more than 30 minutes, and 27±3 g was collected and filled into the die cavity, and the Platen was operated for 4 minutes to measure.

After measuring the Mooney viscosity, the slope of the change in Mooney viscosity that appears when the torque is released was measured, and the absolute value of this was used to obtain the Mooney relaxation rate.

4) N content

N content was measured using a trace nitrogen quantitative analyzer (NSX-2100H) by the NSX analysis method. Specifically, the trace nitrogen quantitative analyzer (Auto sampler, Horizontal furnace, PMT & Nitrogen detector) was turned on and the carrier gas flow rates were set to 250 ml/min for Ar, 350 ml/min for O ₂ , and 300 ml/min for ozonizer, and the heater was set to 800℃. The analyzer was then allowed to stabilize for about 3 hours. After the analyzer stabilized, a calibration curve was created using a nitrogen standard (AccuStandard S-22750-01-5 ml) with calibration curve ranges of 5 ppm, 10 ppm, 50 ppm, 100 ppm, and 500 ppm, and the Area corresponding to each concentration was obtained, and a straight line was created using the ratio of the Area to the concentration. After that, a ceramic boat containing 20 mg of the sample was placed on the Auto sampler of the analyzer and measured to obtain the area. The N content was calculated using the area of the obtained sample and the calibration curve.

division Example For reference Comparative example 1 2 3 1 2 3 NMR
(weight%) SM 21 21 21 21 21 21 21 Vinyl 50 50 50 50 50 50 50 GPC Mw(X10 ³ g/mol) 466 460 455 453 461 460 466 Mn(X10 ³ g/mol) 310 305 301 310 309 310 302 Mp(X10 ³ g/mol) 430 424 425 450 431 425 423 PDI 1.50 1.51 1.51 1.46 1.49 1.48 1.54 Mooney Point (MV) 64 68 67 57 53 60 58 Muni easing rate 1.0024 1.0057 1.0088 1.0653 1.0022 1.1502 1.0091 N content (ppm) 264 288 287 268 126 149 151

As confirmed through the above Table 1, Examples 1 to 3 showed a significant increase in the intramolecular N content compared to Comparative Examples 1 to 3, and further, although Example 1 applied the same modifier as Comparative Examples 1 to 3, it showed a significant increase of 2.1 times compared to Comparative Example 1, 1.8 times compared to Comparative Example, and 1.7 times compared to Comparative Example 3. Through this, it can be confirmed that the modified conjugated diene polymer according to the present invention includes a modified monomer-derived unit within the polymer chain and at least at one terminal separately from the modifier-derived functional group, and is thus highly modified.

Experimental example 2

In order to compare and analyze the properties of the rubber compositions containing each modified conjugated diene copolymer manufactured in the above examples and comparative examples and the molded articles manufactured therefrom, the tensile properties and viscoelastic properties were measured respectively, and the results are shown in Table 3 below.

1) Manufacturing of rubber specimens

Each of the modified or unmodified conjugated diene polymers of the examples, comparative examples, and reference examples was mixed as raw rubber under the mixing conditions shown in Table 2 below. The contents of the raw materials in Table 2 are each part by weight based on 100 parts by weight of the raw rubber.

division raw material Content (weight parts) Stage 1 Mixing rubber 100 Silica 70 Coupling agent (X50S) 11.2 Fair trade 37.5 Zinc oxide 3 Stearic acid 2 Antioxidant 2 Anti-aging agent 2 Wax 1 2nd stage mixing sulfur 1.5 Rubber accelerator 1.75 Vulcanization accelerator 2

Specifically, the above rubber specimen is mixed through first-stage mixing and second-stage mixing. In the first-stage mixing, a semi-automatic mixer equipped with a temperature control device was used to mix raw rubber, silica (filler), an organosilane coupling agent (X50S, Evonik), a process oil (TDAE oil), a zincating agent (ZnO), stearic acid, an antioxidant (TMQ (RD) (2,2,4-trimethyl-1,2-dihydroquinoline polymer), an anti-aging agent (6PPD ((dimethylbutyl)-N-phenyl-phenylenediamine)), and wax (Microcrystaline Wax). At this time, the initial temperature of the mixer was controlled to 70°C, and after mixing was completed, the first mixture was obtained at a discharge temperature of 145°C to 155°C. In the second-stage mixing, the first mixture was cooled to room temperature, and then the first mixture, sulfur, a rubber accelerator (DPD (diphenylguanine)), and A vulcanization accelerator (CZ (N-cytohexyl-2-benzothiazylsulfenamide)) was added and mixed at a temperature of 100°C or lower to obtain a secondary compound. Afterwards, a rubber specimen was manufactured through a curing process at 160°C for 20 minutes.

2) Tensile properties

Tensile properties were measured by manufacturing each test piece according to the tensile test method of ASTM 412, and measuring the tensile strength at break and the tensile stress at 300% elongation (300% modulus) of the test piece. Specifically, the tensile properties were measured at room temperature at a speed of 50 cm/min using a Universal Test Machin 4204 (Instron) tensile tester.

3) Viscoelastic properties

Viscoelastic properties were measured for viscoelastic behavior for dynamic deformation at a frequency of 10 Hz and each measurement temperature (-60℃ to 60℃) using a dynamic mechanical analyzer (GABO Corporation) in Film Tension mode, and the tan δ value was confirmed. In the measurement results, a higher tan δ value at low temperature 0℃ indicates better wet road resistance, and a lower tan δ value at high temperature 60℃ indicates less hysteresis loss and better rolling resistance characteristics (fuel efficiency). However, since the result values in Table 3 are expressed as an index based on the result values of Comparative Example 1, a higher value indicates better.

4) Processability characteristics

The Mooney viscosity (MV, (ML1+4, @100℃) MU) of the secondary compound obtained during the manufacture of the above 1) rubber specimen was measured to compare and analyze the processability characteristics of each polymer. A lower Mooney viscosity measurement value indicates better processability characteristics.

Specifically, using MV-2000 (ALPHA Technologies), a Large Rotor with a Rotor Speed of 2±0.02 rpm at 100℃, each secondary compound was left at room temperature (23±3℃) for more than 30 minutes, and then 27±3 g was collected and filled into the die cavity, and the Platen was operated for measurement for 4 minutes.

division Example For reference Comparative example 1 2 3 1 2 3 Tensile properties Tensile strength (kgf/cm ² ) 187 187 186 179 175 170 179 300% modulus (kgf/cm ² ) 121 123 121 110 105 100 105 Viscoelastic properties tan δ(at 0℃) 105 104 104 105 101 100 102 tan δ(at 60℃) 135 131 132 89 83 100 90 Processability characteristics 98 99 98 88 105 100 101

As shown in Table 3 above, Examples 1 to 3 exhibited comparable processability characteristics compared to Comparative Examples 1 to 3 and Reference Example, while simultaneously exhibiting significantly superior tensile properties and viscoelastic properties.

Specifically, Examples 1 to 3 showed significantly improved tensile properties and viscoelastic properties, especially cloud resistance properties, compared to Comparative Examples 1 to 3, and at the same time, showed equally excellent processability properties. In this case, Comparative Example 1 is a modified conjugated diene polymer manufactured without using a modified monomer, and Comparative Examples 2 and 3 are modified conjugated diene polymers manufactured using a modified monomer only at the initial stage (or initiation point) or later stage of polymerization, respectively.

Through the results in Table 1 and Table 3 above, it can be seen that the modified conjugated diene polymer according to the present invention contains a modified monomer-derived unit within the polymer chain and at least at one terminal, separately from the functional group derived from the modifier, and thus has better affinity with the filler, making it more effective in improving tensile properties and viscoelastic properties.

Claims (14)

A polymer chain comprising a repeating unit derived from a conjugated diene monomer; a unit derived from a modified monomer represented by the following chemical formula 1; and a functional group derived from a modifier,
The above modified monomer derived unit is bonded within the polymer chain and caps at least one end,
The above-mentioned denaturant-derived functional group is bonded to a denaturing monomer-derived unit capping the polymer chain end,
A modified conjugated diene polymer, wherein the above-mentioned modifier is a compound represented by the following chemical formula 2 or chemical formula 3:
[Chemical Formula 1]

In the above chemical formula 1,
R ₁ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms,
R ₂ is a single bond or an alkylene group having 1 to 20 carbon atoms, which is unsubstituted or substituted with a substituent,
R ₃ and R ₄ are independently an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, or an aryl group having 6 to 30 carbon atoms, which is unsubstituted or substituted with a substituent,
The above substituent is at least one selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, and an aryl group having 6 to 20 carbon atoms.
[Chemical formula 2]

In the above chemical formula 2,
R _a1 and R _a4 are independently a single bond or an alkylene group having 1 to 10 carbon atoms,
R _a2 and R _a3 are independently an alkyl group having 1 to 10 carbon atoms,
R _a5 is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a divalent, trivalent or tetravalent alkylsilyl group substituted with an alkyl group having 1 to 10 carbon atoms,
n ₁ is an integer from 1 to 3,
n ₂ is an integer from 0 to 2,
[Chemical Formula 3]

In the above chemical formula 3,
A ₁ and A ₂ are independently an alkylene group having 1 to 20 carbon atoms,
R _b1 to R _b4 are independently an alkyl group having 1 to 20 carbon atoms,
L ₁ to L ₄ are each independently a divalent, trivalent or tetravalent alkylsilyl group substituted with an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms or an alkyl group having 1 to 10 carbon atoms.
In claim 1,
In the above chemical formula 1, R ₁ is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms,
R ₂ is a single bond or an unsubstituted alkylene group having 1 to 10 carbon atoms,
A modified conjugated diene polymer, wherein R ₃ and R ₄ are each independently an unsubstituted alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, or an aryl group having 6 to 12 carbon atoms.
In claim 1,
A modified conjugated diene polymer wherein the polymer chain further comprises a repeating unit derived from an aromatic vinyl monomer.
In claim 1,
The above polymer chain comprises a repeating unit derived from a conjugated diene monomer and a unit derived from a modified monomer,
A modified conjugated diene polymer, wherein at least one terminal of the polymer chain is bonded with a unit derived from a modified monomer and a functional group derived from a modifier.
In claim 1,
A modified conjugated diene polymer having a number average molecular weight (Mn) of 1,000 to 2,000,000 g/mol, a weight average molecular weight (Mw) of 1,000 to 3,000,000 g/mol, and a peak average molecular weight (Mp) of 1,000 to 3,000,000 g/mol.
In claim 1,
A modified conjugated diene polymer having a molecular weight distribution of 1.0 or more and less than 1.7.
In claim 1,
A modified conjugated diene polymer having an N content of 200 ppm or more by weight.
delete In claim 1,
In the above chemical formula 2, R _a1 and R _a4 are each independently a single bond or an alkylene group having 1 to 5 carbon atoms, R _a2 and R _a3 are each independently an alkyl group having 1 to 5 carbon atoms, R _a5 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a tetravalent alkylsilyl group substituted with an alkyl group having 1 to 5 carbon atoms,
A modified conjugated diene polymer, wherein in the chemical formula 3, A ₁ and A ₂ are each independently an alkylene group having 1 to 10 carbon atoms, R _b1 to R _b4 are each independently an alkyl group having 1 to 10 carbon atoms, and L ₁ to L ₄ are each independently a tetravalent alkylsilyl group substituted with an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an alkyl group having 1 to 5 carbon atoms.
A step (S1) of producing an active polymer chain including a modified monomer-derived unit by polymerizing a first modified monomer and a conjugated diene monomer or a conjugated diene monomer and an aromatic vinyl monomer in the presence of a polymerization initiator in a carbon solvent;
Step (S2) of adding a second modified monomer to the above active polymer chain and reacting it to cap the terminal with a second modified monomer-derived unit to produce a capped polymer chain; and
A step (S3) of adding a denaturant to the capped polymer chain and reacting the same,
The above steps (S1); (S2); and (S3) are performed sequentially, and the second modified monomer is added at a time point when the polymerization conversion rate of step (S1) is 90% or higher, and the denaturant is added at a time point when the polymerization conversion rate of step (S2) is 90% or higher.
The above first modified monomer and second modified monomer are compounds represented by the following chemical formula 1,
A method for producing a modified conjugated diene polymer according to claim 1, wherein the above-mentioned modifying agent is a compound represented by the following chemical formula 2 or chemical formula 3:
[Chemical Formula 1]

In the above chemical formula 1,
R ₁ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms,
R ₂ is a single bond or an alkylene group having 1 to 20 carbon atoms, which is unsubstituted or substituted with a substituent,
R ₃ and R ₄ are independently an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, or an aryl group having 6 to 30 carbon atoms, which is unsubstituted or substituted with a substituent,
The above substituent is at least one selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, and an aryl group having 6 to 20 carbon atoms.
[Chemical formula 2]

In the above chemical formula 2,
R _a1 and R _a4 are independently a single bond or an alkylene group having 1 to 10 carbon atoms,
R _a2 and R _a3 are independently an alkyl group having 1 to 10 carbon atoms,
R _a5 is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a divalent, trivalent or tetravalent alkylsilyl group substituted with an alkyl group having 1 to 10 carbon atoms,
n ₁ is an integer from 1 to 3,
n ₂ is an integer from 0 to 2,
[Chemical Formula 3]

In the above chemical formula 3,
A ₁ and A ₂ are independently an alkylene group having 1 to 20 carbon atoms,
R _b1 to R _b4 are independently an alkyl group having 1 to 20 carbon atoms,
L ₁ to L ₄ are each independently a divalent, trivalent or tetravalent alkylsilyl group substituted with an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms or an alkyl group having 1 to 10 carbon atoms.
In claim 10,
A method for producing a modified conjugated diene polymer, wherein the above-mentioned modifier is used in an amount of 0.1 to 10 mol per 1 mol of the polymerization initiator.
In claim 10,
A method for producing a modified conjugated diene polymer, wherein the first modified monomer and the second modified monomer are each used in an amount of 0.1 to 50 mol per 1 mol of the polymerization initiator.
A rubber composition comprising a modified conjugated diene polymer and a filler as described in claim 1.
In claim 13,
A rubber composition comprising 0.1 to 200 parts by weight of a filler based on 100 parts by weight of the modified conjugated diene polymer.