KR101821698B1 - A method for preparing high-cis 1,4-polybutadiene having excellent workability - Google Patents

Abstract

In an embodiment of the present invention, at least one butadiene monomer is polymerized in the presence of a catalyst to prepare a reaction mixture, and then a different sulfur compound, specifically, a sulfur chloride compound and an alkoxysilyl sulfur compound are sequentially added to the reaction mixture Polybutadiene. ≪ / RTI >

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for producing 1,4-polybutadiene,

The present invention relates to a process for producing gossyp 1,4-polybutadiene, and more particularly to a process for producing gossyc 1,4-polybutadiene by reacting two sulfur compounds different from the molecular chain of gossyp 1,4- To a process for producing gossyp 1,4-polybutadiene which improves processability by controlling the viscosity of polybutadiene.

As the demand for rubber compositions increases in various manufacturing fields such as tires, shoe soles, golf balls, etc., the value of conjugated diene-based polymers, especially butadiene-based polymers, which are synthetic rubbers as substitutes for natural rubber, .

Generally, the structure of the conjugated diene polymer greatly affects the physical properties of the polymer. Specifically, the lower the linearity and the larger the branching, the higher the dissolution rate and viscosity characteristics of the polymer, and as a result, the processability of the polymer is improved. However, when the branching of the polymer is large, the molecular weight distribution is widened, so that the mechanical properties of the polymer, which affects the abrasion resistance, cracking resistance or rebound characteristics of the rubber composition, are rather deteriorated.

Further, the linearity or degree of branching of the conjugated diene-based polymer, particularly the butadiene-based polymer, largely depends on the content of the cis 1,4-bond contained in the polymer. The higher the content of the cis 1,4-bond in the conjugated diene polymer is, the more the linearity is increased. As a result, the polymer has excellent mechanical properties, so that the abrasion resistance, crack resistance and rebound characteristics of the rubber composition can be improved.

Accordingly, a variety of methods for producing conjugated diene-based polymers for increasing the linearity and imparting appropriate processability by increasing the content of cis-1,4 bond in the conjugated diene polymer have been researched and developed. For example, a method of producing a conjugated diene polymer having a high degree of linearity by using a polymerization system containing a lanthanide-based rare earth element-containing compound, in particular, a neodymium compound, or using a polymerization system containing a nickel- .

Typically, gossyp 1,4-polybutadiene having a high content of cis 1,4-bonds, for example, greater than 90% by weight, is a polybutadiene of linear structure, or a product of high sheath content, branched polybutadiene, and the like. The linear 1,4-polybutadiene is superior in terms of final properties but poor in processability. On the other hand, the branched polybutadiene has a very low cold flow and is excellent in storage stability, and has excellent filler dispersibility such as carbon black Is excellent in workability such as easy mixing workability and excellent extrudability, but has a disadvantage in that the final physical properties of the product are insufficient.

As such, since the physical properties and processability of gossyp 1,4-polybutadiene exist in trade-off due to its linearity or branching, -Butadiene and its preparation method is increasing.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems of the prior art, and an object of the present invention is to provide a process for producing gossyp 1,4-polybutadiene which is excellent in processability and storage stability while maintaining mechanical properties and dynamic properties.

One aspect of the present invention is a process for preparing a reaction mixture comprising: (a) polymerizing at least one butadiene monomer in the presence of a catalyst to prepare a reaction mixture; (b) adding a first sulfur compound represented by the following formula (1) to the reaction mixture to react,

[Chemical Formula 1]

S _a XY

Wherein S is sulfur, X and Y are the same or different from each other and are one or more oxygen or halogen atoms, and a is an integer of 1 to 10; (c) adding a second sulfur compound represented by the following formula (2) to the reaction mixture and reacting the mixture.

(2)

(R ¹ ) _p (R ² ) _q Si-R ³ -S _b -R ³ -Si (R ¹ ) _p (R ² ) _q

In the above formula (2), S is sulfur, Si is silicon, R ¹ and R ² are the same or different and each is an alkyl group or an alkoxy group of C 1 to C 5, R ³ is a C 1 to C 10 alkylene group, 3, p + q = 3, and b is an integer of 2 to 10.

In one embodiment, the catalyst may be a niodinium-based catalyst prepared from a monomolecular nioium salt compound.

In one embodiment, the monomolecular niobium salt compound is selected from the group consisting of nioium hexanoate, neodymium heptanoate, nioaldioctanoate, nioiodooctoate, niohumidnaphthenate, A stearate, and a niodum bathate.

In one embodiment, the catalyst may be a nickel based catalyst prepared from a monomolecular nickel salt compound.

In one embodiment, the monomolecular nickel salt compound is selected from the group consisting of nickel hexanoate, nickel heptanoate, nickel octanoate, nickel octoate, nickel naphthenate, nickel stearate and nickel bathate Or more.

In one embodiment, 0.01 to 0.1 part by weight of the first sulfur compound may be added to 100 parts by weight of the butadiene monomer in the step (b).

In one embodiment, 0.1 to 0.5 parts by weight of the second sulfur compound may be added to 100 parts by weight of the butadiene monomer in the step (c).

In one embodiment, steps (b) and (c) may be performed sequentially.

In one embodiment, the first sulfur compound may be selected from the group consisting of S ₂ Cl ₂ , SCl ₂ , SOCl ₂ , S ₂ Br ₂ , SOBr _2, and mixtures of two or more thereof.

In one embodiment, the second sulfur compound is selected from the group consisting of trimethoxysilylpropyltrisulfide, trimethoxysilylpropyltrisulfide, trimethoxysilylpropyldisulfide, triethoxysilylpropyltrisulfide, triethoxysilylpropyltrisulfide , Triethoxysilylpropyl disulfide, triisopropylsilylpropyltetrasulfide, triisopropylsilylpropyltrisulfide, triisopropylsilylpropyl disulfide, triisobutylsilylpropyltetrasulfide, triisobutylsilylpropyltrisulfide, triisobutyl Silyl propyl disulfide, and mixtures of two or more thereof.

According to one aspect of the present invention, two kinds of sulfur compounds different from the molecular chain of gossyhex 1,4-polybutadiene are sequentially reacted to control the viscosity and low-temperature flowability of gossyp 1,4-polybutadiene, The storage stability can be improved.

Further, according to another aspect of the present invention, the processability, mechanical properties, and dynamic properties of a product produced using the gossyp 1,4-polybutadiene can be improved.

It should be understood that the effects of the present invention are not limited to the effects described above, but include all effects that can be deduced from the description of the invention or the composition of the invention set forth in the claims.

1 shows the results of gas permeation chromatography (GPC) analysis of gossyp 1,4-polybutadiene according to Examples and Comparative Examples of the present invention.
Figure 2 shows an infrared spectroscopy (IR) spectrum of gossyp 1,4-polybutadiene according to one embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "indirectly connected" . Also, when an element is referred to as "comprising ", it means that it can include other elements, not excluding other elements unless specifically stated otherwise.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

One aspect of the present invention is a process for preparing a reaction mixture comprising: (a) polymerizing at least one butadiene monomer in the presence of a catalyst to prepare a reaction mixture; (b) adding a first sulfur compound represented by the following formula (1) to the reaction mixture to react,

[Chemical Formula 1]

S _a XY

Wherein S is sulfur, X and Y are the same or different from each other and are one or more oxygen or halogen atoms, and a is an integer of 1 to 10; (c) adding a second sulfur compound represented by the following formula (2) to the reaction mixture and reacting the mixture.

(2)

(R ¹ ) _p (R ² ) _q Si-R ³ -S _b -R ³ -Si (R ¹ ) _p (R ² ) _q

In the above formula (2), S is sulfur, Si is silicon, R ¹ and R ² are the same or different and each is an alkyl group or an alkoxy group of C 1 to C 5, R ³ is a C 1 to C 10 alkylene group, 3, p + q = 3, and b is an integer of 2 to 10.

In the step (a), one or more butadiene monomers may be polymerized in the presence of a catalyst to prepare a gossey 1,4-polybutadiene molecular chain.

The catalyst may be a niodinium-based catalyst prepared from a monomolecular niobium salt compound. As used herein, the term "monomeric" means a compound of the form prepared by coordinating a ligand with a central metal element. Wherein the monomolecular niobium salt compound is selected from the group consisting of nioium hexanoate, neodymium heptanoate, neodymium octanoate, neodymium octoate, neodymium naphthenate, neodymium stearate, And may be at least one member selected from the group consisting of naphthoic acid, naphthoic acid, and naphthoic acid, but is not limited thereto.

Specifically, the niodinium-based catalyst is prepared by mixing the monomolecular nioium salt compound, the chlorinated organoaluminum compound and the at least one organoaluminum compound at a predetermined molar ratio, for example, at a molar ratio of 1: 1 to 5:20 to 30 And may have been aged under certain conditions.

The organoaluminum chloride compound may be diethylaluminum chloride, and the organoaluminum compound may be trimethylaluminum, triethylaluminum, tripropylaluminum, tributylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum and diisobutyl Aluminum hydride, and the like.

The catalyst may be a nickel-based catalyst prepared from a monomolecular nickel salt compound. The monomolecular nickel salt compound may be at least one selected from the group consisting of nickel hexanoate, nickel heptanoate, nickel octanoate, nickel octoate, nickel naphthenate, nickel stearate and nickel bathate, May be, but are not limited to, nickel octoate.

Specifically, the nickel-based catalyst is prepared by mixing the monomolecular nickel salt compound, boron fluoride complex compound and at least one organoaluminum compound at a predetermined molar ratio, for example, in a molar ratio of 1: 5 to 15: 5 to 10, ≪ / RTI >

The boron fluoride complex may be a compound in which one or more of an ether compound, a ketone compound and an ester compound, preferably an ether compound, is complexed with triethylboron (BF ₃ ). For example, the ether compound may be at least one selected from the group consisting of dimethyl ether, diethyl ether, dibutyl ether, tetrahydrofuran, dihexyl ether, dioctyl ether and methyl t-butyl ether.

When the one or more butadiene monomers are polymerized in the presence of a catalyst in the step (a), the amount of cis-1,4-butadiene is 90% by weight or more, preferably 95% Is generated. The gossyp 1,4-polybutadiene may have a linear structure composed of molecular chains. Linear gossyhex 1,4-polybutadiene is superior in mechanical properties to the products prepared therefrom, but has low productivity and storage stability because of its high viscosity and low temperature flowability.

Accordingly, in the step (b), the linear gossypial 1,4-polybutadiene molecular chain prepared in the step (a) is reacted with the first sulfur compound represented by the following general formula (1) The molecular chains can be converted to branched.

[Chemical Formula 1]

S _a XY

In the general formula (1), S is sulfur, X and Y are the same or different from each other and are one or more oxygen or halogen atoms, and a is an integer of 1 to 10. Preferably, a may be 1 or 2, wherein the first sulfur compound is selected from the group consisting of S ₂ Cl ₂ , SCl ₂ , SOCl ₂ , S ₂ Br ₂ , SOBr ₂ and mixtures of two or more thereof , Preferably, but not limited to, disulfur dichloride (S ₂ Cl ₂ ). For example, the first sulfur compound may have a halogen atom bonded to both ends of a chain composed of 3 to 10 sulfur atoms (S), and may be represented by the following formula (3).

(3)

XS _a -X '

In Formula 3, a is one of integers from 3 to 10, and X and X 'may be the same or different from each other.

The amount of the first sulfur compound added may be 0.01 to 0.1 parts by weight based on 100 parts by weight of the butadiene monomer as a reactant in the step (a). If the amount of the first sulfur compound added is less than 0.01 parts by weight, the viscosity of the 1,4-polybutadiene and the combination thereof may be high and the processability may be deteriorated. If the amount is more than 0.1 parts by weight, The physical properties may be deteriorated.

In step (c), the branched gossypse 1,4-polybutadiene produced in step (b) is reacted with a second sulfur compound represented by the following formula 2 to form the branched gossyce 1,4-polybutadiene Can be increased. In particular, the second sulfur compound may act as a coupling agent for the branched gossyp 1,4-polybutadiene produced in step (b) or the like. In general, the application of a "coupling agent" as a reactant to a (living) polymer usually involves one fraction of the linear or unconjugated polymer and one or more fractions containing two or more polymer arms at the coupling point A polymer blend can be formed.

(2)

(R ¹ ) _p (R ² ) _q Si-R ³ -S _b -R ³ -Si (R ¹ ) _p (R ² ) _q

In the above formula (2), S is sulfur, Si is silicon, R ¹ and R ² are the same or different and each is an alkyl group or an alkoxy group of C 1 to C 5, R ³ is a C 1 to C 10 alkylene group, 3, p + q = 3, and b is one of integers from 2 to 10.

For example, when the second sulfur compound is selected from the group consisting of trimethoxysilylpropyltrisulfide, trimethoxysilylpropyltrisulfide, trimethoxysilylpropyldisulfide, triethoxysilylpropyltetrasulfide, triethoxysilylpropyltrisulfide, tri But are not limited to, ethoxysilylpropyl disulfide, triisopropylsilylpropyltrisulfide, triisopropylsilylpropyltrisulfide, triisopropylsilylpropyl disulfide, triisobutylsilylpropyltetrasulfide, triisobutylsilylpropyltrisulfide, triisobutylsilylpropyl Disulfide, and mixtures of two or more thereof.

The number of sulfur atoms connecting the alkoxysilane groups located at both ends of the molecule in the second sulfur compound may affect the branching of the resulting branched gossyp 1,4-polybutadiene and thus its viscosity and processability . That is, when the number of the sulfur atoms is small, the viscosity can not be lowered to a required level, and if the number of the sulfur atoms is excessively large, the mechanical properties of the product may be deteriorated. Accordingly, the second sulfur compound may be trimethoxysilylpropyltetrasulfide or triethoxysilylpropyltetrasulfide, in which the integer b in Formula 2 is 3 or more, and more preferably 4.

The amount of the second sulfur compound added may be 0.1 to 0.5 parts by weight based on 100 parts by weight of the butadiene monomer as the reactant in the step (a). If the amount of the first sulfur compound added is less than 0.1 parts by weight, the viscosity of 1,4-polybutadiene and the combination thereof may be high, and the processability may be deteriorated. If the amount is more than 0.5 parts by weight, The physical properties may be deteriorated.

The reaction time and the reaction temperature of the respective reactants and the first and second sulfur compounds in the steps (b) and (c) can be freely adjusted in the range of 20 ° C to 80 ° C for 20 minutes to 2 hours, respectively.

The steps (b) and (c) may be performed sequentially. That is, the linear Gossey 1,4-polybutadiene molecular chain and the first sulfur compound are first reacted to cross-link the linear Gossey 1,4-polybutadiene molecular chain, and then the second sulfur compound And the ends of the crosslinked linear gossyp 1,4-polybutadiene molecular chain are coupled to each other to balance both the mechanical properties and the processability of the gossyp 1,4-polybutadiene. In particular, the gossy < RTI ID = 0.0 > 1,4-polybutadiene < / RTI > prepared according to the above procedure may have improved processability due to reduced solution viscosity compared to linear polymers of similar number average molecular weight or weight average molecular weight.

Hereinafter, embodiments of the present invention will be described in detail.

Example  One

The Ziegler-Natta catalyst used in the reaction was a mixture of monomolecular sodium diiodide (1.0%, cyclohexane solution), diethyl aluminum chloride (1M, cyclohexane solution), diisobutyl aluminum hydride (15% (1M, heptane solution), and the molar ratio of each catalyst was 1: 2: 10: 15, and the content of nioium in the monodisperse sodium diiodobutate was 1.5 x 10 ^{- 4} moles. At this time, the weight ratio of the monomer to the polymerization solvent was adjusted to 1: 5.

After sufficiently blowing nitrogen into the 5 L pressure glass reactor, cyclohexane polymerization solvent, triisobutylaluminum, diisobutylaluminum hydride, diethylaluminum chloride and niobium dihydrotungate were added according to the above ratios, and then 400 g of butadiene And the mixture was reacted at 60 DEG C for 2 hours.

After the reaction, 0.08 g (0.02 phm, 'parts per hundred monomer') of disulfur dichloride was added slowly and the reaction was carried out for 40 minutes. Then, 0.4 g (0.1 phm ) Was added slowly and then reacted for an additional 40 minutes. Thereafter, the reaction terminator and the antioxidant were added to terminate the reaction.

Example  2

A series of reactions were performed in the same manner as in Example 1 except that the amounts of disulfur dichloride and triethoxysilylpropyltetrasulfide were changed to 0.16 g (0.04 phm) and 0.8 g (0.2 phm), respectively .

Example  3

The Ziegler-Natta catalyst used in the reaction was monomolecular nickel octoate (0.05%, toluene solution), triethylboron ethyl ether (1.5%, toluene solution) and triethyl aluminum (0.8%, toluene solution) The content of nickel in octoate is 7.0 x 10 ^{< -5} > mol per 100 g of monomers. Nickel octoate, triethylboron ethyl ether and triethyl aluminum were added sequentially to a 150 mL Schlenk flask in a nitrogen-filled state at a molar ratio of 1: 10: 6, followed by aging the catalyst at 20 ° C for 1 hour.

A 5 L pressure glass reactor was sufficiently blown with nitrogen, and then a heptane polymerization solvent and aged Ziegler-Natta catalyst were added according to the above ratios. Then, 400 g of butadiene as a monomer was added and reacted at 60 ° C for 2 hours.

After the reaction, 0.16 g (0.04 phm) of disulfide dichloride was added slowly, and the reaction was carried out for 40 minutes. Then, 0.8 g (0.2 phm) of triethoxysilylpropyltetrasulfide was slowly added thereto, followed by further reaction for 40 minutes. Thereafter, the reaction terminator and the antioxidant were added to terminate the reaction.

Comparative Example  One

A series of reactions were carried out in the same manner as in Example 1 except that 0.4 g (0.1 phm) of triethoxysilylpropyltetrasulfide was added and the reaction was omitted.

Comparative Example  2

A series of reactions were carried out in the same manner as in Example 1, except that 0.08 g (0.02 phm) of disulfur dichloride was added and the reaction was omitted.

Comparative Example  3

A series of reactions were carried out in the same manner as in Example 1 except that 0.08 g (0.02 phm) of disulfur dichloride and 0.4 g (0.1 phm) of triethoxysilylpropyltetrasulfide were added and the reaction was omitted. Respectively.

Comparative Example  4

A series of reactions were carried out in the same manner as in Example 2 except that the order of introduction of disulfur dichloride and triethoxysilylpropyltetrasulfide was changed.

Comparative Example  5

A series of reactions were carried out in the same manner as in Example 3, except that 0.16 g (0.04 phm) of disulfur dichloride and 0.8 g (0.2 phm) of triethoxysilylpropyltetrasulfide were added and the reaction was omitted. Respectively.

The types of catalysts and the amounts of sulfur compounds used in the examples and comparative examples are shown in Table 1 below.

division catalyst Disulfur
Dichloride
(phm) Triethoxysilylpropyl
Tetrasulfide
(phm) Example 1 Nd series 0.02 0.1 Example 2 Nd series 0.04 0.2 Example 3 Ni system 0.04 0.2 Comparative Example 1 Nd series 0.02 - Comparative Example 2 Nd series - 0.1 Comparative Example 3 Nd series - - Comparative Example 4 Nd series 0.04 0.2 Comparative Example 5 Ni system - -

The molecular weight of the branched 1,4-polybutadiene produced according to the Examples and Comparative Examples was measured by gas permeation chromatography (GPC), and the Mooney viscosity and low-temperature flowability were measured. The results are shown in Table 2 below Respectively.

division Mn Mw Mw / Mn Solution viscosity
(SV, cps) Mooney viscosity
(MV, ML _{1 + 4} , 100 ° C) Linearity
(MV / SV) Low temperature flowability
(mg / min) Example 1 283 645 2.3 195 42.9 2.2 0.6 Example 2 266 695 2.6 190 46.5 2.4 0.6 Example 3 164 705 4.3 125 42.1 3.4 0.3 Comparative Example 1 266 629 2.4 194 41.6 2.2 0.8 Comparative Example 2 280 717 2.6 228 43.9 1.9 1.1 Comparative Example 3 317 802 2.5 230 42 1.8 1.9 Comparative Example 4 239 594 2.5 200 40.7 2.0 1.2 Comparative Example 5 159 668 4.2 136 41.9 3.1 0.5

Referring to Table 2, it was found that the low temperature flowability of Example 1 was significantly improved as compared with Comparative Examples 1 and 2 in which disulfur dichloride or triethoxysilylpropyl tetrasulfide was alternatively used. In Comparative Example 1, the solution viscosity was similar to that in Example 1, so that a favorable effect was obtained from the viewpoint of processability. However, the low-temperature flowability was high and Example 1 exhibited more balanced physical properties.

When the physical properties of Example 1 and Comparative Example 3 using the niodiesel-based catalyst and those of Example 3 and Comparative Example 5 using the nickel-based catalyst were compared, the solution viscosity and low-temperature flowability of Examples 1 and 3 were significantly And the processability and storage stability were improved.

On the other hand, in Comparative Example 4 in which triethoxysilylpropyltetrasulfite was first reacted among the two sulfur compounds, unlike Example 2, the solution viscosity and low-temperature flowability were high, and the processability and storage stability were lowered.

The gas permeation chromatography analysis results of the 1,4-polybutadiene of Example 1 and Comparative Examples 1 and 3 are shown in FIG. Referring to FIG. 1, in the case of Example 1 and Comparative Example 1 in which a sulfur compound was used, a polymer having a molecular chain bonded at a retention time of 11 to 12 minutes after the application of a sulfur compound to that of Comparative Example 3 Is eluted. The infrared spectroscopic (IR) spectrum of the 1,4-polybutadiene of Example 1 is shown in FIG. 2 and Table 3 below.

division Wave number (cm ^-1 ) Before the administration of the sulfur compound (Abs) After administration of the sulfur compound (Abs) S-Cl About 400 0.1 0.088 Si-O-Si Approximately 1,000 0.111 0.331

When reference to Fig. 2 and Table 3, di-di-sulfur chloride and then the reaction was an S-Cl bonding peak decreased from 400cm ^-1, and then a silyl ethoxy propyl tetrasulfide the reaction in the tree at 1,000cm ^-1 Si-O -Si stretching peak is increased, and the 1,4-polybutadiene molecular chain is bridged by the electrophilic bond by disulfide dichloride and the silane condensation reaction by triethoxysilylpropyltetrasulfide to have a branched structure Respectively.

Manufacturing example  And Comparative Manufacturing Example

50 parts by weight of natural rubber, zinc oxide, stearic acid, carbon black, and process oil were blended in a 500 cc brabender at 120 캜 with respect to 50 parts by weight of the branched 1,4-polybutadiene of the examples and comparative examples, , And a vulcanization accelerator were mixed and stirred to prepare a blend.

The blend was kneaded at 80 DEG C on a roll mill, processed into a flat sheet form on a 2 mm thick roll, and left for 24 hours. Then, vulcanization was carried out at the crosslinking time measured by RPA (Rubber Process Analyzer) using a press at 160 캜 to prepare a 2 mm-thick sheet specimen.

Sheet specimens including the branched 1,4-polybutadiene of Examples 1 to 3 and Comparative Examples 1 to 5 were referred to as Production Examples 1 to 3 and Comparative Production Examples 1 to 5, respectively, and the composition of each sheet specimen Are shown in Table 4 below.

Furtherance Manufacturing example
One Manufacturing example
2 Manufacturing example
3 compare
Manufacturing example
One compare
Manufacturing example
2 compare
Manufacturing example
3 compare
Manufacturing example
4 compare
Manufacturing example
5 Natural rubber 50 50 50 50 50 50 50 50 Example 1 50 Example 2 50 Example 3 50 Comparative Example 1 50 Comparative Example 2 50 Comparative Example 3 50 Comparative Example 4 50 Comparative Example 5 50 Zinc oxide 3 3 3 3 3 3 3 3 Stearic acid 2 2 2 2 2 2 2 2 Carbon black 60 60 60 60 60 60 60 60 Process oil 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 sulfur 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Vulcanization accelerator 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5

(Unit: parts by weight)

Experimental Example

The mechanical and dynamic properties of the sheet specimens prepared according to Production Examples 1 to 3 and Comparative Production Examples 1 to 5 were measured and compared, and the results are shown in Table 5 below. The method of measuring the physical properties is as follows.

- Hardness: measured by ASTM shore-A method

100%, 300% modulus: measured the stress acting in the specimen to the specimen 25 ℃ when 100%, 300% elongation (unit: kgf / ² m)

- Tensile strength: Measured according to ASTM D 790 (unit: kgf / m ² )

- Elongation: strain is measured in% until the specimen is broken using a tensile tester.

-Tanδ: Using a Dynamic Mechanical Thermal Analyzer (DMTA), a temperature sweep is performed to measure the value at 60 ° C

Properties Manufacturing example
One Manufacturing example
2 Manufacturing example
3 compare
Manufacturing example
One compare
Manufacturing example
2 compare
Manufacturing example
3 compare
Manufacturing example
4 compare
Manufacturing example
5 Mooney viscosity
(ML _{1 + 4} , 100 ° C) 89.0 89.3 86.5 91.6 92.5 93.2 90.7 88.4 Hardness 72 72 71 72 72 72 71 71 100%
Modulus 40.6 41.6 39.6 40.7 42.8 38.1 40.1 36.2 300%
Modulus 175.1 177.5 173.8 175.5 173.8 167.3 173.5 170.5 The tensile strength 246.3 248.3 245.6 247.6 239.5 238.2 245.1 240.1 Elongation 406.9. 406.8 410.5 411.5 410.7 420.2 411 419.2 Tanδ 0.095 0.095 0.097 0.095 0.097 0.101 0.099 0.105

Referring to Table 5, the sheet specimen of Production Example 1 has a lower Mooney viscosity than Comparative Production Examples 1 and 2, and thus has excellent processability. Particularly, Tan δ is lower than Comparative Production Example 2,

Further, when the physical properties of Production Example 1 and Comparative Production Example 3 using the niodiesel-based catalyst and Production Example 3 and Comparative Production Example 5 using the nickel-based catalyst were compared, respectively, the Mooney viscosity and Tanδ of Production Examples 1 and 3 were low Not only has excellent processability and dynamic properties, but also has excellent mechanical properties such as hardness, modulus and tensile strength.

On the other hand, in contrast to Production Example 2, the sheet specimen of Comparative Production Example 4 prepared using 1,4-polybutadiene in which triethoxysilylpropyltetrasulfite was first reacted in the two sulfur compounds, Processability, dynamic properties, and mechanical properties were all lowered.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

Claims (10)

(a) polymerizing at least one butadiene monomer in the presence of a catalyst to produce linear 1,4-polybutadiene;
(b) reacting the linear 1,4-polybutadiene with a first sulfur compound represented by the following general formula (1) to produce a branched 1,4-polybutadiene,
[Chemical Formula 1]
S _a XY
Wherein S is sulfur, X and Y are the same or different from each other and are one or more oxygen or halogen atoms, and a is an integer of 1 to 10;
(c) reacting the branched 1,4-polybutadiene with a second sulfur compound represented by the following formula (2) to increase the branching degree of the branched 1,4-polybutadiene. - Preparation of polybutadiene:
(2)
(R ¹ ) _p (R ² ) _q Si-R ³ -S _b -R ³ -Si (R ¹ ) _p (R ² ) _q
In the above formula (2), S is sulfur, Si is silicon, R ¹ and R ² are the same or different and each is an alkyl group or an alkoxy group of C 1 to C 5, R ³ is a C 1 to C 10 alkylene group, 3, p + q = 3, and b is an integer of 3 to 10. The method according to claim 1,
Wherein the catalyst is a niodinium-based catalyst prepared from a monomolecular nioium salt compound. 3. The method of claim 2,
Wherein the monomolecular niobium salt compound is selected from the group consisting of nioium hexanoate, neodymium heptanoate, niodooctanoate, nioiodooctoate, niohumidnaphthenate, nioodium stearate and nioium And at least one selected from the group consisting of propylene glycol, propylene glycol, and propylene glycol. The method according to claim 1,
Wherein the catalyst is a nickel-based catalyst prepared from a monomolecular nickel salt compound. 5. The method of claim 4,
Wherein the monomolecular nickel salt compound is at least one selected from the group consisting of nickel hexanoate, nickel heptanoate, nickel octanoate, nickel octoate, nickel naphthenate, nickel stearate and nickel bathate, A process for producing polybutadiene. The method according to claim 1,
Wherein 0.01 to 0.1 parts by weight of the first sulfur compound is added to 100 parts by weight of the butadiene monomer in the step (b). The method according to claim 1,
Wherein 0.1 to 0.5 parts by weight of the second sulfur compound is added to 100 parts by weight of the butadiene monomer in the step (c). The method according to claim 1,
Wherein the steps (b) and (c) are carried out sequentially. The method according to claim 1,
Wherein the first sulfur compound is one selected from the group consisting of S ₂ Cl ₂ , SCl ₂ , SOCl ₂ , S ₂ Br ₂ , SOBr ₂ and a mixture of two or more thereof. The method according to claim 1,
Wherein the second sulfur compound is selected from the group consisting of trimethoxysilylpropyltrisulfide, trimethoxysilylpropyltrisulfide, triethoxysilylpropyltetrasulfide, triethoxysilylpropyltrisulfide, triisopropylsilylpropyltetrasulfide, triisopropylsilyl Propyl trisulfide, triisobutylsilylpropyl tetrasulfide, triisobutylsilylpropyl trisulfide, and mixtures of two or more thereof.

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