KR20160064820A - Method for preparing diene based polymer and diene based polymer prepared using the same - Google Patents

Abstract

The present invention provides a method of preparing a diene-based polymer including polymerizing a diene monomer in a non-polar solvent in the presence of a polymerization catalyst, represented by chemical formula 1, including a neodymium compound, a halogen compound, and an alkylating agent, wherein the diene monomer is added thereto over two or more steps, and to a diene-based polymer prepared thereby and exhibiting excellent processability. In chemical formula 1, R1 to R3 are as defined in the specification of the present invention.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a method for producing a diene-based polymer, and a diene-based polymer prepared by using the same. BACKGROUND ART [0002]

The present invention relates to a process for producing a diene polymer exhibiting excellent processability and a diene polymer produced by using the same.

As the demand for rubber increases in various manufacturing fields such as tires, impact polystyrene, shoe soles, and golf balls, the value of polybutadiene rubber, an intermediary of petrochemical products, is increasing as a substitute for natural rubber, which lacks production.

Butadiene polymers such as polybutadiene rubber are known as thermally and mechanically excellent rubbers and are widely used in various fields. Particularly, since the more the cis-1,4-bond content in the butadiene monomer unit is, the more excellent mechanical properties can be exhibited, a great deal of research has been conducted on a method for producing a butadiene polymer having a high cis- ought.

Specifically, a method for producing a butadiene-based polymer by using a rare earth metal compound such as neodymium and a polymerization catalyst of a complex metal consisting of an alkylating agent of Group I to Group III, specifically methylaluminoxane has been developed. However, the polymer obtained by the above method has a problem that the cis-1,4 bond content is not sufficiently high and the vinyl content is not sufficiently low, so that the physical properties are still insufficient.

Alternatively, a polymerization catalyst comprising a rare earth metal compound, an alkylating agent of Group I to Group III, and an ionic compound consisting of a non-coordinating anion and a cation is used to prepare a butadiene-based polymer having a high cis- Was developed. However, the above method uses Nd (OCOCCl ₃ ) ₃ as a rare earth metal compound, but since the polymerization activity of the compound is low and the vinyl bond content of the butadiene polymer is large, the content of the butadiene- The rubber composition has insufficient improvement in physical properties as compared with the rubber composition containing the conventional butadiene polymer. In the case of the butadiene polymer produced by the above method, the lower the vinyl bond content, the wider the molecular weight distribution is, and it is difficult to obtain the butadiene polymer having a sufficiently low vinyl bond content and a molecular weight distribution within a specific range.

As another method, there has been developed a method for producing a butadiene polymer having a high cis-1,4 bond content by using a polymerization catalyst composed of a rare earth metal salt composed of a halogen atom-containing component and aluminoxane. However, this method also has a problem that since the specific catalyst such as neodymium salt of bis (trichloroacetic acid) (bersatanic acid) is used, the polymerization activity of the neodymium salt is low and the industrial property is low.

On the other hand, neodymium-catalyzed polybutadiene (Nd-BR) has superior characteristics in terms of running resistance, abrasion resistance and rebound resilience, compared with a high proportion of cis-polybutadiene. In addition, the linear Nd-BR exhibits improved dynamic properties and a low energy absorption rate, which reduces running resistance in the tire field and improves rebound resilience in golf ball applications. However, since the linear rubber has a high solution viscosity, the processability is lowered, and the dissolution rate is slow, and the practicality is low from the viewpoint of economy.

Branching is particularly important for the processability of the polymer. Specifically, the branching affects the dissolution rate and viscosity characteristics of the polymer, which affects the processability of the polymer. As a result, there is a possibility that the physical properties of the molded article are deteriorated by using a polymer having deteriorated processability.

Japanese Patent Laid-Open No. 2001-048940

The first object of the present invention is to provide a process for producing a diene polymer exhibiting excellent processability due to a high degree of branching in the polymer chain together with a molecular weight distribution of bimodal.

A second technical object of the present invention is to provide a diene polymer produced by the above production process.

However, the technical problem to be solved by the present invention is not limited to the above-mentioned problems, and other matters not mentioned can be clearly understood by those skilled in the art from the following description.

According to an embodiment of the present invention, there is provided a process for polymerizing a diene monomer in a nonpolar solvent in the presence of a polymerization catalyst, wherein the catalyst for polymerization is a neodymium compound represented by the following formula And an alkylating agent, wherein the diene-based monomer is added in two or more divided doses:

[Chemical Formula 1]

In Formula 1,

R ₁ is a linear or branched alkyl group having 6 to 12 carbon atoms,

R ₂ and R ₃ are each independently a hydrogen atom or a linear or branched alkyl group having from 2 to 8 carbon atoms, provided that R ₂ and R ₃ are not hydrogen atoms at the same time.

According to another embodiment of the present invention, there is provided a diene polymer produced by the above production method.

Other details of the embodiments of the present invention are included in the following detailed description.

According to the present invention, it is possible to produce a diene polymer exhibiting excellent processability owing to the high molecular weight distribution in the polymer chain together with the molecular weight distribution of bimodal.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments of the invention and, together with the description of the invention, It should not be construed as limited.
1 is a graph showing molecular weight distributions of the butadiene polymers prepared in Examples 1 and 2 and Comparative Examples 1 and 2. FIG.

Hereinafter, the present invention will be described in detail in order to facilitate understanding of the present invention.

The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms and the inventor may appropriately define the concept of the term in order to best describe its invention It should be construed as meaning and concept consistent with the technical idea of the present invention.

Dien series  Method of producing polymer

A method for producing a diene-based polymer according to an embodiment of the present invention is a method for producing a diene-based polymer by reacting a diene-based monomer in two or more times in the presence of a neodymium compound represented by the following formula (1), a halogen compound and an alkylating agent in a nonpolar solvent And subjecting the mixture to polymerization reaction:

[Chemical Formula 1]

In Formula 1,

R ₁ is a linear or branched alkyl group having 6 to 12 carbon atoms,

R ₂ and R ₃ are each independently a hydrogen atom or a linear or branched alkyl group having from 2 to 8 carbon atoms, provided that R ₂ and R ₃ are not hydrogen atoms at the same time.

More specifically, in Formula 1, R ₁ is a linear or branched alkyl group having 6 to 8 carbon atoms, R ₂ and R ₃ are independently hydrogen or a linear or branched alkyl group having 2 to 6 carbon atoms, R ₂ and R ₃ are not simultaneously hydrogen.

In the method for producing a diene-based polymer according to an embodiment of the present invention, a mixture prepared by mixing the neodymium compound, the alkylating agent, and the halogen compound of Formula 1 is used as the catalyst for polymerization.

In the above catalyst for polymerization, the neodymium compound of Formula 1 has a pseudo-living character and enables pseudo-living polymerization. As a result, it is possible to produce a diene-based polymer capable of exhibiting excellent processability due to bimodal molecular weight distribution.

As a neodymium compound used as a catalyst in the conventional diene polymerization process, Nd (neodecanoate) ₃ compound containing a carboxylate ligand in which two methyl groups are substituted at the? -Position was used. However, in the case of the Nd (neodecanoate) ₃ compound, the Nd (neodecanoate) ₃ compound is present in a large amount in the form of an oligomer such as the following formula (2) at the time of polymerization and causes a decrease in efficiency of conversion to a catalytically active species, There is a disadvantage.

(2)

On the contrary, the neodymium compound of Formula 1 used in the present invention contains a carboxylate ligand containing a variety of alkyl groups as substituents in the α-position instead of the conventional neodecanoate group as a ligand, The change is prevented by the entanglement between the compounds and there is no fear of oligomerization. In addition, the neodymium compound of Formula 1 has a high solubility in a polymerization solvent and has a low neodymium ratio in a central portion, which is difficult to convert to a catalytically active species, and thus has a high conversion ratio to a catalytically active species.

Specifically, the neodymium compound of Formula 1 may be at least one selected from the group consisting of Nd (2,2-diethyldecanoate) ₃ , Nd (2,2-dipropyldecanoate) ₃ , Nd (2,2-dibutyldecanoate) _3, Nd (2,2- di-hexyl decanoate) _3, Nd (2,2- dioctyl decanoate) _3, Nd (2- ethyl-2-propyl decanoate) _3, Nd (2- ethyl 2-butyl decanoate) _3, Nd (2- ethyl-2-hexyl decanoate) _3, Nd (2- butyl-2-propyl decanoate) _3, Nd (2- propyl-2-hexyl de decanoate) _3, Nd (2- propyl-2-isopropyl decanoate) _3, Nd (2- butyl-2-hexyl decanoate) _3, Nd (2- cyclohexyl-2-octyl decanoate) ₃ , Nd (2-t- butyl decanoate) _3, Nd (2,2- diethyl octanoate) _3, Nd (2,2- dipropyl octanoate) _3, Nd (2,2- dibutyl octanoate) _3, Nd (2,2- dihexyl octanoate) _3, Nd (2- ethyl-2-propyl-octanoate) _3, Nd (2- ethyl-hexyl-2-octanoate) _3, Nd (2,2-diethyl nonanoate) ₃ , Nd (2,2- Dipropyl no nano-benzoate) _3, Nd (2,2- dibutyl no nano-benzoate) _3, Nd (2,2- dihexyl no nano-benzoate) _3, Nd (2- ethyl-2-propyl-no nano-benzoate) ₃ Or Nd (2-ethyl-2-hexylnonanoate) ₃ , and any one or a mixture of two or more thereof may be used. More particularly the neodymium compounds are Nd (2,2- diethyl decanoate) _3, Nd (2,2- dipropyl decanoate) _3, Nd (2,2- di-butyl decanoate) _3, Nd (2,2-dihexyldecanoate) ₃ , and Nd (2,2-dioctyldecanoate) ₃ .

The neodymium compound of Formula 1 may have a weight average molecular weight (Mw) of 800 to 1400 g / mol. When the weight average molecular weight is within the above-mentioned range, more excellent catalytic activity can be exhibited.

The solubility of the neodymium compound of Formula 1 may be about 4 g or more per 6 g of non-polar solvent at room temperature (25 ° C). In the present invention, the solubility of the neodymium compound means a degree of dissolution without cloudiness. By exhibiting such high solubility, excellent catalytic activity can be exhibited.

In addition, the neodymium compound of Formula 1 may exhibit catalyst activity of 600 kg [polymer] / mol [Nd] · h or more over a polymerization time of 30 minutes. In the present invention, the catalytic activity is a value obtained from the molar ratio of the neodymium compound introduced in the formula (1) to the total amount of the produced diene polymer.

The neodymium compound of Formula 1 may be used in an amount of 0.1 to 0.5 mmol, more specifically 0.1 to 0.2 mmol, per 100 g of the diene monomer. If the amount of the neodymium compound of Formula 1 is less than 0.1 mmol, the catalyst activity for polymerization is low. If the amount of neodymium compound exceeds 0.5 mmol, the catalyst concentration becomes too high, and a demineralization process is required.

In the above catalyst for polymerization, the alkylating agent is an organometallic compound capable of transferring a hydrocarbyl group to another metal, and serves as a cocatalyst. The alkylating agent is not particularly limited as long as it is used as an alkylating agent in the production of a diene-based polymer. Specifically, the alkylating agent may be an organometallic compound soluble in a non-polar solvent such as an organoaluminum compound, an organomagnesium compound, or an organolithium compound and containing a metal-carbon bond.

More specifically, the organoaluminum compounds include diethylaluminum hydride, di-n-propylaluminum hydride, diisopropylaluminum hydride, di-n-butylaluminum hydride, diisobutylaluminum hydride (DIBAH) Di-n-octylaluminum hydride, diphenylaluminum hydride, di-p-tolylaluminum hydride, dibenzylaluminum hydride, phenylethylaluminum hydride, phenyl-n-propylaluminum hydride, phenylisopropylaluminum N-butyl aluminum hydride, phenyl isobutyl aluminum hydride, phenyl-n-octyl aluminum hydride, p-tolylethyl aluminum hydride, p-tolyl-n-propyl aluminum hydride, p- Isopropyl aluminum hydride, p-tolyl-n-butyl aluminum hydride, p-tolyl iso N-butyl aluminum hydride, benzyl isobutyl aluminum hydride, benzyl isobutyl aluminum hydride, benzyl isobutyl aluminum hydride, benzyl isobutyl aluminum hydride, benzyl isobutyl aluminum hydride, benzyl isobutyl aluminum hydride, Dihydrocarbylaluminum hydride such as aluminum hydride or benzyl-n-octylaluminum hydrogen; Hydrocarbylaluminum such as ethylaluminum dihydride, n-propylaluminum dihydride, isopropylaluminum dihydride, n-butylaluminum dihydride, isobutylaluminum dihydride or n-octylaluminum dihydride, Dihydride and the like.

More specifically, examples of the organomagnesium compound include alkylmagnesium compounds such as diethylmagnesium, di-n-propylmagnesium, diisopropylmagnesium, dibutylmagnesium, dihexylmagnesium, diphenylmagnesium and dibenzylmagnesium. And examples of the organic lithium compound include alkyl lithium compounds such as n-butyl lithium and the like.

Any one or a mixture of two or more of the organoaluminum compounds, organomagnesium compounds, and organolithium compounds described above may be used. More specifically, the alkylating agent may be DIBAH, wherein the DIBAH may serve as a molecular weight regulator during polymerization.

The alkylating agent may be used in a molar ratio of 5 to 200 molar equivalents relative to 1 mol of the neodymium compound of the general formula (1), more specifically 5 to 20 molar equivalents, and still more preferably 10 molar equivalents.

In the above-mentioned catalyst for polymerization, the kind of the halogen compound is not particularly limited, but can be used without particular limitation, as long as it is generally used as a halogenating agent in the production of a diene-based polymer. Specifically, the halogen compound may be an aluminum halogen compound or an inorganic halogen compound in which aluminum is substituted with boron, silicon, tin or titanium in the aluminum halogen compound, or an organic halogen compound such as a t-alkylhalogen compound (alkyl having 4 to 20 carbon atoms) Halogen compounds.

More specifically, examples of the inorganic halogen compound include dimethylaluminum chloride, diethylaluminum chloride (DEAC), dimethylaluminum bromide, diethylaluminum bromide, dimethylaluminum fluoride, diethylaluminum fluoride, methylaluminum dichloride, ethylaluminum dichloride , Methylaluminum dibromide, ethylaluminum dibromide, methylaluminum difluoride, ethylaluminum difluoride, methylaluminum sesquichloride, ethylaluminum sesquichloride, isobutylaluminum sesquichloride, methylmagnesium chloride, methylmagnesium bromide, Methylmagnesium iodide, ethylmagnesium chloride, ethylmagnesium bromide, butylmagnesium chloride, butylmagnesium bromide, phenylmagnesium chloride, phenylmagnesium bromide, Di-t-butyl tin dichloride, di-t-butyl tin dibromide, dibutyl tin dichloride, dibutyl tin dichloride, dibutyl tin dichloride, dibutyl tin dichloride, dibutyl tin dichloride, dibutyl tin dichloride, dibutyl tin dichloride, dibutyl tin dichloride, Tin dibromide, tributyltin chloride, tributyltin bromide, and the like.

Examples of the organic halogen compound include t-butyl chloride, t-butyl bromide, allyl chloride, allyl bromide, benzyl chloride, benzyl bromide, chloro- di- phenyl methane, There may be mentioned triphenylmethylbromide, benzylidene chloride, benzylidene bromide, methyltrichlorosilane, phenyltrichlorosilane, dimethyldichlorosilane, diphenyldichlorosilane, trimethylchlorosilane, benzoyl chloride, benzoyl bromide, propionyl chloride, propionyl bromide, Methyl chloroformate, methyl bromoformate, and the like.

Any one or a mixture of two or more of the above-mentioned inorganic halogen compounds and organic halogen compounds may be used.

The halogen compound may be used in a molar ratio of 1 to 20 molar equivalents, more preferably 1 to 5 molar equivalents, and more preferably 2.4 molar equivalents relative to 1 mol of the neodymium compound of the formula (1).

The catalyst for polymerization may further include a diene-based monomer.

As described above, a part of the diene-based monomer used in the present polymerization reaction is preliminarily mixed with the polymerization catalyst and used in the form of a preforming catalyst, whereby the activity of the catalyst can be improved, .

Specific examples of the diene monomer include 1,3-butadiene, isoprene, 1,3-pentadiene, 1,3-hexadiene, 2,3-dimethyl-1,3-butadiene, Butadiene, 2-methyl-1,3-pentadiene, 3-methyl-1,3-pentadiene, 4-methyl-1,3-pentadiene or 2,4-hexadiene. Any one or a mixture of two or more may be used.

The diene monomer which can be used in the production of the polymerization catalyst may be used in an amount within a range of the total amount of the diene monomer used in the polymerization reaction. Specifically, 1 equivalent of the neodymium compound of the formula To 50 equivalents, more specifically 20 to 35 equivalents, and even more specifically 33 equivalents.

In addition, the catalyst for polymerization may further include an organoaluminum oxy compound (or aluminoxane) to improve catalytic activity.

Specific examples of the aluminoxane include methyl aluminoxane, ethyl aluminoxane, propyl aluminoxane, butyl aluminoxane, and chloraluminoxane. Any one or a mixture of two or more of them may be used.

The aluminoxane may be used in a molar ratio of 1 to 50, more specifically 1 to 20, based on 1 mole of the neodymium compound of Formula 1.

The catalyst for polymerization may be prepared by sequentially charging a neodymium compound of Formula 1, an alkylating agent, a halogen compound, and optionally a diene monomer into the nonpolar solvent.

The nonpolar solvent is a nonpolar solvent that is not reactive with the above-mentioned catalyst components, specifically, an aliphatic hydrocarbon solvent such as pentane, hexane, isopentane, heptane, octane, isooctane and the like; Cyclic aliphatic hydrocarbon solvents such as cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, ethylcyclohexane and the like; Or an aromatic hydrocarbon solvent such as benzene, toluene, ethylbenzene, xylene, etc., and any one or a mixture of two or more of them may be used. More specifically, the nonpolar solvent may be hexane.

Further, in order to improve the polymerization activity and to shorten the induction period of the polymerization initiation, it is also possible to selectively carry out a step of mixing and reacting the above components in advance, followed by aging. At this time, the aging temperature may be 0 to 100 캜, more specifically 20 to 80 캜. If the aging temperature is only 0 占 폚, aging is not sufficient, and if it exceeds 100 占 폚, the catalytic activity may decrease.

When the diene polymer is polymerized using such a catalyst system, the catalytic activity can be remarkably improved to about 1.37 x 10 ³ kg [polymer] / mol [Nd] · h or more, and as a result, the cis content, A diene polymer having a 1,4-cis content of 95% or more can be produced.

In the method for producing a diene-based polymer according to an embodiment of the present invention, the polymerization reaction may be carried out by radical polymerization, and specifically may be bulk polymerization, solution polymerization, suspension polymerization or emulsion polymerization, May be solution polymerization.

More specifically, the polymerization reaction may be carried out by charging the diene monomer into the polymerization catalyst in a non-polar solvent and reacting.

In this case, the diene-based monomer is not completely dissolved in a non-polar solvent and used in the production of the diene-based polymer, but a part of the total amount of the diene-based monomer is dissolved in a non-polar solvent and polymerized. Specifically, it may be added two or more times, more specifically two to four times.

The amount of the diene-based monomer, the number of times of introduction, and the time of introduction may vary, and may be determined depending on polymerization conversion of the diene-based monomer.

Specifically, the polymerization reaction is initiated in the presence of 50 to 90% by weight, more specifically 50 to 80% by weight, of the total amount of the diene-based monomer, and when the polymerization conversion is 50 to 80%, the remaining amount of the diene- As shown in FIG.

More specifically, when the diene monomer is dividedly added in two portions, the amount of the diene monomer is 50 to 80% by weight based on the total amount of the diene monomer used at the initial polymerization stage (when the polymerization conversion is 0%) and the polymerization conversion is 50 to 80% The amount of the remainder can be input. When the diene monomer is dividedly added in three portions, an amount of 50 to 60% by weight based on the total amount of the diene-based monomer in the initial stage of polymerization (when the polymerization conversion is 0%) is 20 To 30% by weight, and the polymerization conversion ratio is 80 to 90%. When the diene monomer is dividedly added in four portions, an amount of 50 to 60% by weight based on the total amount of the diene monomer used at the initial stage of polymerization (at a polymerization conversion of 0%) is 15% To 25% by weight is an amount of 10 to 15% by weight based on the amount of use when the polymerization conversion ratio is 70%, and the remaining amount when the polymerization conversion rate is 80%.

Specific examples of the diene monomer include 1,3-butadiene, isoprene, 1,3-pentadiene, 1,3-hexadiene, 2,3-dimethyl-1,3-butadiene, Methyl-1,3-pentadiene, 4-methyl-1,3-pentadiene, or 2,4-hexadiene, and any one of them or Two or more mixtures may be used. More specifically, the diene-based monomer may be 1,3-butadiene.

In addition, other monomers copolymerizable with the diene monomer may be further used in consideration of the physical properties of the diene polymer finally produced during the polymerization reaction.

Specific examples of the other monomers include styrene, p-methylstyrene,? -Methylstyrene, 1-vinylnaphthalene, 3-vinyltoluene, ethylvinylbenzene, divinylbenzene, 4-cyclohexylstyrene, 2,4,6- Styrene, etc., and any one or a mixture of two or more thereof may be used. The other monomers may be used in an amount of 20% by weight or less based on the total weight of the monomers used in the polymerization reaction.

In addition, the polymerization reaction can be carried out in a non-polar solvent such as a diluent.

The nonpolar solvent may be added in addition to the amount of the nonpolar solvent that can be used to prepare the catalyst for polymerization, wherein the nonpolar solvent may be the same as described above.

When the non-polar solvent is used, the concentration of the monomer is not particularly limited, but may be 3 to 80% by weight, more specifically 10 to 30% by weight.

In addition, a reaction terminator for completing the polymerization reaction such as polyoxyethylene glycol phosphate or the like during the polymerization reaction; Or antioxidants such as 2,6-di-t-butyl paracresol and the like may further be used. In addition, additives such as a solvent, a chelating agent, a dispersing agent, a pH adjusting agent, an oxygen scavenger, and an oxygen scavenger may be further optionally added to the solution.

The polymerization reaction may be carried out at a temperature of from 20 to 200 ° C, more specifically from 20 to 70 ° C, for from 15 minutes to 3 hours, more specifically from 2 hours to 3 hours. If the temperature during the polymerization reaction exceeds 200 ° C, it is difficult to sufficiently control the polymerization reaction, and the content of cis-1,4 bond in the resultant diene polymer may be lowered. If the temperature is lower than 20 캜, the polymerization reaction rate and efficiency may be lowered.

As a result of the polymerization reaction, a neodymium-catalyzed diene polymer containing an active organometallic moiety derived from a catalyst comprising the neodymium compound of Formula 1, more specifically, a neodymium-catalyzed diene polymer containing 1,3-butadiene monomer units Butadiene-based polymer is produced.

The prepared neodymium-catalyzed diene-based polymer may have pseudo-living properties. Accordingly, prior to the execution of the subsequent step 2 process, a step of functionalizing the produced neodymium-catalyzed diene-based polymer may optionally be further carried out.

Specifically, the neodymium-catalyzed diene polymer is reacted with the active organometallic moiety in a diene polymer containing an active organometallic moiety to treat a terminal modifier that modifies the terminal of the diene polymer, Can be modified with a functional group having an interaction with an inorganic filler such as carbon black or silica. The terminal modifier may increase the molecular weight by adding the functional group to the polymer or by coupling when reacting with the diene polymer.

Specifically, the terminal modifier may be at least one selected from the group consisting of azacyclopropane, ketone, carboxyl, thiocarboxyl, carbonate, carboxylic anhydride, carboxylate, At least one functional group selected from the group consisting of an isocyanate group, a halogenated isocyanate group, an epoxy group, a thioepoxy group, an imine group and an MZ bond (wherein M is selected from the group consisting of Sn, Si, Ge and P and Z is a halogen atom) And does not contain active proton and onium salts which inactivate the active organometallic moiety.

More specifically, the termination modifier is selected from the group consisting of alkoxysilanes, imine-containing compounds, esters, ester-carboxylate metal complexes, alkyl ester carboxylate metal complexes, aldehydes or ketones, amides, isocyanates, isothiocyanates, Or a mixture of two or more thereof.

The terminal modifier may be used in an amount of 0.01 to 200 equivalents, more specifically 0.1 to 150 equivalents, based on 1 equivalent of the neodymium compound of the formula (1).

The diene polymer may have a modifying ratio of 15% or more, specifically, 80% or more. In the present invention, the modification ratio is the number of moles of the functional group derived from the denaturant introduced into the diene polymer, relative to the total number of moles of the diene polymer.

After completion of the reaction, the produced diene polymer may be obtained by precipitating a lower alcohol such as methyl alcohol, ethyl alcohol, or steam. Accordingly, the method for preparing a diene-based polymer according to an embodiment of the present invention may further include a step of precipitating and separating the diene-based polymer produced after the polymerization reaction.

The filtration, separation and drying of the precipitated diene polymer may be carried out according to a conventional method.

As described above, the method for producing a diene-based polymer according to one embodiment of the present invention is capable of pseudocoloring a diene monomer using a neodymium compound of the formula (1) having pseudo-living properties, and as a result, it is possible to produce a diene polymer having a molecular weight distribution and a high degree of branching of bimodal and exhibiting improved processability, more specifically a neodymium-catalyzed butadiene-based polymer.

Dien series  polymer

According to another embodiment of the present invention, there is provided a diene polymer produced by the above production method.

Specifically, the diene polymer is a neodymium-catalyzed diene polymer comprising an active organometal moiety derived from a catalyst comprising the neodymium compound of Formula 1, more specifically a neodymium catalyst comprising a 1,3-butadiene monomer unit Butadiene-based polymer.

Also, the diene polymer may contain 80 to 100% by weight of 1,3-butadiene monomer units and optionally 20% by weight or less of other monomer units copolymerizable with 1,3-butadiene. If the 1,3-butadiene monomer unit content in the diene polymer is less than 80% by weight, the 1,4-cis content of the polymer may be lowered. Specific examples of the other monomers copolymerizable with 1,3-butadiene include 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, , 3-hexadiene, and the like; Or an aromatic vinyl monomer such as styrene, p-methylstyrene,? -Methylstyrene, or vinylnaphthalene, and any one or two or more of these compounds may be used.

In addition, the diene polymer may be polybutadiene comprising only 1,3-butadiene monomer.

In addition, the diene polymer may have a polydispersity index (PDI, Mw / Mn) of 2.95 to 3, more specifically 2.95 to 2.97 according to a specific production method thereof, and may have a bimodal molecular weight distribution have. If the molecular weight distribution of the diene polymer is less than 2.95, the workability of the rubber composition containing the diene polymer tends to be deteriorated and the kneading of the rubber composition is difficult, so that it is difficult to sufficiently improve the physical properties of the rubber composition. When the molecular weight distribution of the diene polymer exceeds 3, There is a possibility that the physical properties of the rubber such as hysteresis loss of the composition may be deteriorated.

The diene polymer preferably has a cis content of the diene polymer measured by Fourier transform infrared spectroscopy, specifically, a cis-1,4-bond content of 95% or more, more specifically 95 to 98% . Since the cis-1,4 bond content in the 1,3-butadiene monomer unit is larger than that of the conventional butadiene polymer and the vinyl bond content is low, the extensibility of the rubber composition is remarkably high and the abrasion resistance , Crack resistance and ozone resistance can be improved.

The weight average molecular weight (Mw) of the diene polymer may be from 6 × 10 ⁵ g / mol to 9 × 10 ⁵ g / mol, more specifically from 6.4 × 10 ⁵ g / mol to 8.1 × 10 ⁵ g / mol. The number average molecular weight (Mn) of the diene polymer may be from 2 × ^{10 5} g / mol to 3 × 10 ⁵ g / mol, more specifically from 2.1 × 10 ⁵ g / mol to 2.8 × 10 ⁵ g / mol. In the present invention, the weight-average molecular weight and the number-average molecular weight are the polystyrene-reduced molecular weights analyzed by gel permeation chromatography (GPC), respectively. When the diene polymer has a weight average molecular weight of less than 600,000 g / mol or a number average molecular weight of less than 100,000 g / mol, the elastic modulus of the vulcanized article is lowered, hysteresis loss is increased, and furthermore abrasion resistance is deteriorated. When the weight average molecular weight is 900,000 g / mol or more than 500,000 g / mol, the workability of the rubber composition containing the diene polymer is deteriorated and the kneading of the rubber composition becomes difficult, and the physical properties of the rubber composition can not be sufficiently improved.

In addition, the diene polymer exhibits a high degree of branching due to the batch addition of butadiene during its production. Specifically, the degree of branching (SV / MV) may be 5 to 8. The higher the degree of branching, the lower the solution viscosity. In the present invention, the solution viscosity (SV) is divided by the Mooney viscosity (MV) for the purpose of relative comparison.

Specifically, the diene polymer may have a Mooney viscosity (MV) at 100 ° C of 40 to 100 cP, more specifically 40 to 90 cP. The solution viscosity (SV) of the diene polymer may be 200 to 700 cP, more specifically 650 cP.

In the present invention, the Mooney viscosity can be measured using, for example, Monsanto MV2000E at 100 ° C using a Rotor Speed 2 ± 0.02 rpm, Large Rotor. The sample used is allowed to stand at room temperature (23 ± 3 ° C) for more than 30 minutes, and 27 ± 3 g can be collected, filled in the die cavity, and the platen can be measured. Also, the solution viscosity (SV) was carried out in the same manner, and the viscosity of the polymer in 5% toluene was measured at 20 ° C.

The diene polymer may be one in which the terminal of the polymer is modified by a terminal modifier to a functional group having an interaction with an inorganic filler such as carbon black or silica.

Specifically, the functional group may be selected from the group consisting of an azacyclopropane group, a ketone group, a carboxyl group, a thiocarboxyl group, a carbonate, a carboxylic anhydride, a metal carboxylate, an acid halide, a urea, a thiourea, an amide group, a thioamide group, A halogenated isocyanato group, an epoxy group, a thioepoxy group, an imine group and an MZ bond (provided that M is selected from the group consisting of Sn, Si, Ge and P, and Z is a halogen atom).

The diene polymer may have a modifying ratio of 15% or more, specifically, 80% or more. In the present invention, the modification ratio is the number of moles of the functional group derived from the denaturant introduced into the diene polymer, relative to the total number of moles of the diene polymer.

Rubber composition

According to another embodiment of the present invention, there is provided a rubber composition comprising the diene polymer.

Specifically, the rubber composition may include 10 wt% to 100 wt% of the diene polymer and 90 wt% or less of the rubber component. If the content of the diene polymer is less than 10% by weight, the abrasion resistance, crack resistance and ozone resistance improving effect of the rubber composition may be insignificant.

The rubber component is specifically a natural rubber (NR); (Ethylene-co-butadiene copolymer), polybutadiene (BR), polyisoprene (IR), butyl rubber (IIR), ethylene-propylene copolymer, polyisobutylene- (Styrene-co-butadiene), poly (styrene-co-butadiene), poly (styrene-co-butadiene) Propylene-co-diene), polysulfide rubber, acrylic rubber, urethane rubber, silicone rubber, epichlorohydrin rubber and the like, and any one or a mixture of two or more thereof may be used.

The rubber composition may further include at least 10 parts by weight of a filler based on 100 parts by weight of the rubber component. The filler may be carbon black or silica, and any one or a mixture of two or more thereof may be used.

In addition to the above rubber components and fillers, a compounding agent commonly used in the rubber industry such as a vulcanizing agent, a vulcanization accelerator, an antioxidant, an anti-scorch agent, a softener, zinc oxide, stearic acid or a silane coupling agent, It can be appropriately selected and compounded within a range that does not inhibit.

Such rubber compositions are useful in the manufacture of various rubber molded articles such as O-rings, profiles, gaskets, membranes, tires, tire treads, side walls, braking members or hoses.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

( Example  One) Dien series  Preparation of polymer

A neodymium compound represented by the following formula (1a), diisobutylaluminum hydride, diethylaluminum chloride and butadiene were added in a molar ratio of 1:10: 2.4: 33, and then mixed to prepare a polymerization catalyst.

Vacuum and nitrogen were added alternately to the completely dried organic reactor, 150 g of 1,3-butane diene / hexane mixed solution was added to a glass reactor in a vacuum state, the polymerization catalyst prepared above was added, For 60 minutes. When the polymerization conversion was 90%, 250 g of butadiene was further added, and the polymerization reaction was further carried out at the same temperature for 60 minutes. After completion of the reaction, a part of the reaction solution was taken and the conversion was measured. The weight average molecular weight (Mw), number average molecular weight (Mn), polydispersion index (PDI), Mooney viscosity (MV) and cis content of the diene polymer obtained as a result of the polymerization reaction were respectively measured , And the results are shown in Table 1 below.

(1a)

(1a)

( Example  2) Dien series  Preparation of polymer

Polymerization was carried out in the same manner as in Example 1 except that the amount of reactants to be added for producing diene-based polymer was changed as shown in Table 1 below.

After completion of the reaction, a portion of the reaction solution was taken to measure the conversion. Mw, Mn, PDI, MV and Cis content of the diene polymer prepared in the same manner as in Example 1 were measured and shown in Table 1 .

 ( Example  3) Dien series  Preparation of polymer

A diene polymer was prepared in the same manner as in Example 1 except that the compound of the formula (1b) was used as the neodymium compound.

(1b)

(1b)

( Example  4) Dien series  Preparation of polymer

A diene polymer was prepared in the same manner as in Example 1, except that the following compound (1c) was used as the neodymium compound.

(1c)

(1c)

( Example  5) Dien series  Preparation of polymer

A diene polymer was prepared in the same manner as in Example 1, except that the following compound (1d) was used as the neodymium compound.

(1d)

(1d)

( Example  6) Dien series  Preparation of polymer

A diene polymer was prepared in the same manner as in Example 1, except that the following compound (1e) was used as a neodymium compound.

(1e)

(1e)

( Example  7) Dien series  Preparation of polymer

Butadiene was added in an amount of 58.9% of the total amount of butadiene at the beginning of the polymerization at a polymerization conversion of 0%, and the polymerization reaction was carried out for 60 minutes. The polymerization reaction was carried out for 30 minutes at a polymerization conversion of 50% , And the remainder was added at a polymerization conversion of 80% to carry out a polymerization reaction for 30 minutes, to prepare a diene polymer.

( Example  8) Dien series  Preparation of polymer

Butadiene was used in an amount of 54.5% by weight based on the total amount of butadiene used at the initial stage of polymerization at a polymerization conversion rate of 0%, and at an amount of 17.8% by weight based on the total amount used at a polymerization conversion rate of 50% By weight, and the amount of the remainder when the polymerization conversion was 80%, were charged in the same manner as in Example 1 to prepare a diene polymer.

( Comparative Example  One) Dien series  Preparation of polymer

Polymerization was carried out in the same manner as in Example 1, except that the diene monomer was temporarily added during the first polymerization as shown in Table 1 below.

After completion of the reaction, a portion of the reaction solution was taken to measure the conversion. Mw, Mn, PDI, MV and Cis content of the diene polymer prepared in the same manner as in Example 1 were measured and shown in Table 1 .

( Comparative Example  2) Dien series  Preparation of polymer

Polymerization was carried out in the same manner as in Example 1, except that the diene monomer was temporarily added during the first polymerization and the polymerization reaction was carried out for 120 minutes as shown in Table 1 below.

After the completion of the reaction, a portion of the reaction solution was taken and the conversion was measured. The weight average molecular weight (Mw), the number average molecular weight (Mn), the polydispersion index (PDI) of the diene polymer prepared in the same manner as in Example 1, ), Mooney viscosity (MV, (ML1 + 4, @ 100 ° C), solution viscosity (SV), content of cis 1,4 bond and branching degree (SV / MV) were measured.

Weight average molecular weight (Mw), number average molecular weight (Mn), polydispersity index (PDI): Polymers prepared in the above Examples and Comparative Examples were measured using gel permeation chromatography.

Moisture Viscosity (MV, (ML1 + 4, @ 100 ° C) (MU): Measured using Monsanto MV2000E at 100 ° C using Rotor Speed 2 ± 0.02 rpm, Large Rotor at room temperature (23 ± 3 ° C) for more than 30 minutes and then 27 ± 3g was collected, filled in the die cavity, and platen was operated.

Solution Viscosity (SV) The viscosity of the polymer in 5% toluene was measured at 20 ° C.

Branching degree (SV / MV): After measuring the solution viscosity and the Mooney viscosity, respectively, the solution viscosity was divided by the Mooney viscosity and corrected for relative comparison. The lower the SV / MV value, the higher the degree of branching of the polymer.

The content of cis 1,4 bond in the polymer was measured by Fourier transform infrared spectroscopy.

Nd ^{1 )}
(mmol / BD 100g) Polymerization temperature (캜) Primary BD input
(g) First polymerization time (min) Secondary BD input
(g) Second polymerization time (min) Conversion Rate (%) Mn
(X10 ⁵ g / mol) Mw
(X10 ⁵ g / mol) PDI MV SV (cP) Content of cis 1,4 bond (%) Branching degree
(SV / MV) Example 1 0.20 70 250 60 250 60 100 2.18 6.43 2.95 43.2 220 95.8 5.1 Example 2 0.14 70 250 40 103 80 95 2.76. 8.16 2.96 87.6 630 97.8 7.2 Comparative Example 1 0.20 70 500 60 - - 100 2.39 6.95 2.91 47.2 340 97.2 7.2 Comparative Example 2 0.20 70 500 120 - - 100 2.43 6.91 2.85 56.0 360 97.2 6.4

In Table 1, 1) Nd denotes the content of the neodymium compound of Formula 1a as the main catalyst, BD denotes butadiene, MV denotes the Mooney viscosity, and SV denotes the solution viscosity.

The molecular weight distributions of the polymers prepared in Examples 1 and 2 and Comparative Examples 1 and 2 were analyzed, and the results are shown in Fig.

As shown in Table 1 and FIG. 1, the polymers of Comparative Examples 1 and 2 exhibited monomodal molecular weight distribution curves with symmetrical molecular weight distributions, whereas in Examples 1 and 2, the molecular weight distribution curves of vicmald were adjacent Overlapping showed an asymmetric molecular weight distribution curve and broader molecular weight distribution range.

In the case of Example 1 in which 250 g of butadiene was added and the first polymerization was carried out for 60 minutes and then the same amount of butadiene was added again for the same time, the first polymerization was carried out for 40 minutes by adding 250 g of butadiene, followed by addition of 103 g of butadiene The weight average, number average molecular weight, Mooney viscosity and solution viscosity were significantly decreased by the increase of the low molecular weight as compared with Example 2 in which polymerization was carried out for 80 minutes. From this, it can be seen that the physical properties such as the molecular weight distribution and the viscosity characteristics of the diene polymer to be prepared can be controlled by controlling the ratio of the main catalyst and the monomer, the amount of the divided feed, and the time of injection.

In the case of Comparative Example 2 in which butadiene was added at a time but the polymerization reaction time was 2 hours as in Examples 1 and 2, there was no difference in the molecular weight distribution of the polymer produced. From this, it can be confirmed that the increase in the polymerization time does not affect the molecular weight distribution.

Also, the lower the SV / MV value, the higher the degree of branching of the polymer. Comparing the comparative examples 1 and 2, the comparative example 2 in which the polymerization time was 120 minutes as compared with the comparative example 1 in which the polymerization time was 60 minutes showed a lower SV / MV value. Comparing Example 1 and Comparative Example 2 in which the number of times of addition of butadiene was different from that of Comparative Example 2, the polymer of Example 1 in which butadiene was added in two portions was higher than Comparative Example 2 . From this, it can be seen that as the polymerization time becomes longer and as the number of times of splitting is increased, the SV / MV value decreases and the polymer has a higher degree of branching.

In addition, in Example 2, despite the low catalyst and butadiene usage, the degree of branching was comparable to that of Comparative Example 1 due to the increased polymerization time and the double addition of butadiene.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, And falls within the scope of the invention.

Claims (20)

Polymerizing the diene-based monomer in the presence of a polymerization catalyst in a non-polar solvent,
Wherein the polymerization catalyst comprises a neodymium compound represented by the following formula (1), an alkylating agent and a halogen compound,
Wherein the diene monomer is divided into two or more times,
[Chemical Formula 1]

In Formula 1,
R ₁ is a linear or branched alkyl group having 6 to 12 carbon atoms,
R ₂ and R ₃ are each independently a hydrogen atom or a linear or branched alkyl group having from 2 to 8 carbon atoms, provided that R ₂ and R ₃ are not hydrogen atoms at the same time.
The method according to claim 1,
Wherein the polymerization reaction is initiated in the presence of 50 to 90% by weight of the total amount of the diene-based monomer, and when the polymerization conversion to the diene-based polymer is 60 to 90%, the amount of the diene- ≪ / RTI >
The method according to claim 1,
Is the Neodymium compound Nd (2,2- diethyl decanoate) _3, Nd (2,2- dipropyl decanoate) _3, Nd (2,2- di-butyl decanoate) _3, Nd (2, 2-di-hexyl decanoate) _3, Nd (2,2- dioctyl decanoate) _3, Nd (2-ethyl-2-propyl decanoate) _3, Nd (2-ethyl-2-butyl to Kano Eight) _3, Nd (2- ethyl-2-hexyl decanoate) _3, Nd (2- butyl-2-propyl decanoate) _3, Nd (2- propyl-2-hexyl decanoate) _3, Nd (2-propyl-2-isopropyl decanoate) _3, Nd (2-butyl-2-hexyl decanoate) _3, Nd (2-hexyl-2-octyl decanoate) _3, Nd (2-t -butyl decanoate) _3, Nd (2,2- diethyl octanoate) _3, Nd (2,2- dipropyl octanoate) _3, Nd (2,2- dibutyltin octanoate) _3, Nd (2,2- dihexyl octanoate) _3, Nd (2- ethyl-2-propyl-octanoate) _3, Nd (2- ethyl-hexyl-2-octanoate) _3, Nd (2,2- Diethylnonanoate) ₃ , Nd (2,2-dipropylnonanoate) _3, Nd (2,2- dibutyl no nano-benzoate) _3, Nd (2,2- dihexyl no nano-benzoate) _3, Nd (2- ethyl-2-propyl-no nano-benzoate) ₃ and Nd (2- ethyl 2-hexylnonanoate). _{3. The} process for producing a diene-based polymer according to claim 1,
The method according to claim 1,
Wherein the neodymium compound is used in an amount of 0.1 to 0.5 mmol per 100 g of the diene monomer.
The method according to claim 1,
Wherein the alkylating agent comprises any one or a mixture of two or more selected from the group consisting of an alkylaluminum compound, an alkylmagnesium compound, and an alkyllithium compound.
The method according to claim 1,
Wherein the alkylating agent is diisobutyl aluminum hydride.
The method according to claim 1,
Wherein the alkylating agent is used in a molar ratio of 5 to 200 with respect to 1 mole of the neodymium compound.
The method according to claim 1,
Wherein the halogen compound comprises any one or a mixture of two or more selected from the group consisting of an inorganic halogen compound containing at least one element selected from the group consisting of aluminum, boron, silicon, tin and titanium, and an organic halogen compound A method for producing a diene-based polymer.
The method according to claim 1,
Wherein the halogen compound is diethylaluminum chloride.
The method according to claim 1,
Wherein the halogen compound is used in an amount of 1 to 20 moles relative to 1 mole of the neodymium compound.
The method according to claim 1,
Wherein the polymerization catalyst further comprises a diene monomer.
12. The method of claim 11,
Wherein the diene monomer is contained in a molar ratio of 1 to 50 with respect to 1 mole of the neodymium compound.
12. The method of claim 11,
Wherein the diene-based monomer is at least one selected from the group consisting of 1,3-butadiene, isoprene, 1,3-pentadiene, 1,3-hexadiene, 2,3-dimethyl-1,3-butadiene, -Methyl-1,3-pentadiene, 3-methyl-1,3-pentadiene, 4-methyl-1,3-pentadiene and 2,4-hexadiene. ≪ / RTI >
A diene-based polymer produced by the process according to claim 1.
A diene polymer having a polydispersity index (Mw / Mn) of 2.95 to 3 and a bimodal molecular weight distribution.
16. The method of claim 15,
Wherein the weight average molecular weight (Mw) is 6 × 10 ⁵ g / mol to 9 × 10 ⁵ g / mol and the number average molecular weight (Mn) is 2 × ^{10 5} g / mol to 3 × 10 ⁵ g / mol.
16. The method of claim 15,
And a Mooney viscosity at 100 占 폚 of 40 to 100.
16. The method of claim 15,
Wherein the content of the cis 1,4 bond in the diene polymer measured by Fourier transform infrared spectroscopy is 95% or more.
16. The method of claim 15,
Butadiene monomer unit. The diene-based polymer is a butadiene-based polymer containing 1,3-butadiene monomer units.
A rubber composition comprising the diene polymer according to claim 15.

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