WO2011059225A2 - Preparation method of vinyl aromatic hydrocarbon-conjugated diene block copolymer using coupling reaction with improved ion stability - Google Patents

Abstract

The present invention relates to a preparation method of a vinyl aromatic hydrocarbon-conjugated diene block copolymer using coupling polymerization with improved ion stability. According to the present invention, the preparation method of a vinyl aromatic hydrocarbon-conjugated diene block copolymer comprises the following steps of: (a) polymerizing a vinyl aromatic hydrocarbon monomer with an organolithium compound polymerization initiator in a hydrocarbon solvent to prepare a first mixture solution containing a vinyl aromatic hydrocarbon block; and (b) adding a conjugated diene monomer to the first mixture solution of the step (a) to form a conjugated diene block to the terminal of the vinyl aromatic hydrocarbon block, thereby preparing a second mixture solution containing a vinyl aromatic hydrocarbon block-conjugated diene block copolymer, wherein the preparation method comprises the step of (c) adding a Lewis acid to the first mixture solution before the initiation of polymerization of the vinyl aromatic hydrocarbon monomer of the step (a), during polymerization, or the termination of polymerization.

Description

Method for preparing vinyl aromatic hydrocarbon-conjugated diene block copolymer using coupling reaction with improved ion stability

The present invention relates to a method for producing a vinyl aromatic hydrocarbon-conjugated diene block copolymer, and more particularly, to a method for producing a vinyl aromatic hydrocarbon-conjugated diene block copolymer using a coupling reaction with improved ion stability.

Styrene-butadiene-styrene triple block copolymers composed of vinyl aromatic hydrocarbon blocks and conjugated diene blocks are prepared by solution polymerization using an anionic initiator, with the excessive exothermic reaction leading to a polymerization temperature of at least 100 ° C.

Originally anionic polymerization may be stabilized for a long time at room temperature for a long time even in the form of an anion at the end of the polymer chain until the end of the growth reaction and just before the termination reaction. This results in a side reaction where the anions at the end form unsaturated double bonds. Even if the time from the growth reaction to the end of the reaction is within a few minutes, this side reaction cannot be avoided.

Due to such side reactions, the activity of the polymer chain ends is reduced to reduce the coupling efficiency during the polymerization of the coupling, and the reaction proceeds between the anion terminal of the living living polymers and the polymer produced by the side reaction, thereby generating twice the molecular weight as a whole. Usually, 10 to 15% of the total polymerized polymer is produced. In addition, even in the same polymerization formulation, the content of such high molecular weight polymers is not constant and different, and in a product requiring fine molecular weight control, process control is not easy to increase the product defect rate.

In terms of physical properties, this side reaction product increases the physical properties of the produced product, but it may decrease the commerciality of the product because it has to be solution-polymerized at low temperature and low solids content due to deterioration in processability and limitation of control in the polymerization manufacturing process. have. Therefore, even if the polymerization is carried out at a high temperature in order to ensure commerciality, it is possible to stabilize the anion terminal, and there is a need for a technique for maximizing the coupling efficiency and precise molecular weight control by suppressing side reaction generation.

The present invention is to solve the problem of the manufacturing method of the conventional vinyl aromatic hydrocarbon-conjugated diene block copolymer, side reaction is generated by the polymerization of Lewis acid, which is a stabilizing material of the anion chain terminal into the polymerization system of the existing block copolymer It is an object of the present invention to provide a method for producing a vinyl aromatic hydrocarbon-conjugated diene block copolymer capable of precisely controlling the molecular weight of a block copolymer by carrying out a coupling reaction.

The present invention to achieve the above object

(A) polymerizing a vinyl aromatic hydrocarbon monomer with a polymerization initiator of an organolithium compound in a hydrocarbon solvent to form a first mixed solution comprising a vinyl aromatic hydrocarbon block; and

Adding a conjugated diene monomer to the first mixed solution of step (a) to form a conjugated diene block at the end of the vinyl aromatic hydrocarbon block to form a second mixed solution containing the vinylaromatic hydrocarbon block-conjugated diene block (b) ;

In the manufacturing method of a vinyl aromatic hydrocarbon-conjugated diene block copolymer containing,

(C) adding the Lewis acid to the first mixed solution before the start of polymerization of the vinyl aromatic hydrocarbon monomer of step (a), during the polymerization or upon completion of the polymerization; And

A silane compound or an epoxy compound, which is a coupling agent, is added to the second mixed solution of step (b) to cause a coupling reaction.

Forming a vinyl aromatic hydrocarbon-conjugated diene block copolymer having a number average molecular weight of 5,000 to 500,000 and a content of the vinyl aromatic hydrocarbon block of 5 to 50% by weight based on 100% by weight of the vinyl aromatic hydrocarbon-conjugated diene block copolymer ( d);

Provided is a method for preparing a vinyl aromatic hydrocarbon-conjugated diene block copolymer using a coupling polymerization reaction having improved ion stability.

In the present invention, the silane compound and the epoxy compound which are coupling agents may be compounds represented by the following Chemical Formulas 1, 2 or 3, respectively.

[Formula 1]

In Formula 1, R ¹ and R ² are each independently an alkyl group having 1 to 6 carbon atoms, or an aryl group having 5 to 18 carbon atoms, X may be a halogen group,

m, n, and p are each independently an integer of 0 to 4, and m + n + p = 4.

[Formula 2]

In Formula 2, R ³ may be an alkyl group having 1 to 20 carbon atoms, an aryl group having 5 to 24 carbon atoms, or an alkylaryl group having 6 to 30 carbon atoms,

q and r are each independently an integer of 0 to 4, and 2 ≦ q + r ≦ 4.

[Formula 3]

In Formula 3, R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , and R ¹² may be an alkyl group having 1 to 20 carbon atoms, an aryl group having 5 to 24 carbon atoms, or 6 to 6 carbon atoms. It may be an alkylaryl group of 30, s is 1, t and u are each independently an integer of 0 to 1, 1≤s + t + u≤3. In addition, v, w, x is an integer of 1-6 each independently, and 2 <= v + w + x <6.

In the present invention, the Lewis acid may be a compound represented by Formula 4 below.

[Formula 4]

In Formula 3, M is Mg, B, Al, or Zn in the periodic table,

R ¹³ and R ¹⁴ may each independently be an alkyl group having 1 to 6 carbon atoms, an aryl group having 5 to 18 carbon atoms, or an alkylaryl group having 6 to 30 carbon atoms,

k and l are each independently an integer of 0 to 3, and 2 ≦ k + l ≦ 3.

Here the Lewis acid is preferably diethylmagnesium, di-n-propylmagnesium, di-isopropylmagnesium, dibutylmagnesium, triethylaluminum, tri-isobutylaluminum, tri-n-propylaluminum, tri-n-hexyl Aluminum, diethyl aluminum monohydride, diisobutyl aluminum monohydride, diethylzinc, di-n-propyl zinc, di-isoamyl zinc, di-isobutyl zinc, triethylborane, tri-sec-butylborane It may be at least one selected from the group consisting of, tributyl borane, trimethyl borane, and triphenyl borane.

In the present invention, the molar ratio of the Lewis acid / organic lithium compound is 0.05 to 0.2, preferably 0.05 to 0.15, and more preferably 0.05 to 0.1. In this case, a silane compound can be used as the coupling agent.

The silane compound may be at least one selected from the group consisting of silane tetrachloride, methyl trichloride, and dimethyl dichloride.

In the present invention, the molar ratio of the Lewis acid / organic lithium compound is 0.05 to 4, preferably 0.1 to 0.75, in which case an epoxy compound can be used as the coupling agent.

Wherein the epoxy compound is 1,2,7,8-diepoxyoctane, diglycidyl-1,4-butanediol, bisphenol A diglycidyl ether and bisphenol F diglycidyl ether, epoxidized soybean oil oil and It may be at least one selected from the group consisting of epoxidized rinse oil.

In the present invention, the vinyl aromatic hydrocarbons include styrene, alpha methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-propylstyrene, 1-vinylnaphthalene, 4-cyclohexylstyrene, 4- (p-methylphenyl) styrene, and It may be at least one selected from the group consisting of 1-vinyl-5 hexyl naphthalene.

In addition, conjugated dienes include 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, piperiene, 3-butyl-1,3-octadiene, isoprene, and 2-phenyl-1,3-butadiene It may be at least one selected from the group consisting of.

According to the present invention is to solve the problem of the conventional method for producing a vinyl aromatic hydrocarbon-conjugated diene block copolymer, the polymerization reaction of Lewis acid, which is a stabilizing material of the anionic chain terminal and the coupling agent in the polymerization system of the conventional block copolymer Method of producing vinyl aromatic hydrocarbon-conjugated diene block copolymer which can control the molecular weight, molecular weight distribution, viscosity, and processability of the block copolymer precisely by preventing the side reaction from being generated and improving the coupling efficiency during the coupling reaction. The purpose is to provide.

1 is a diagram showing the gel permeation chromatography profile of the polymerization product of Comparative Examples 1 to 3 and Examples 1 to 2.

2 is a view showing a gel permeation chromatography profile of the polymerization product of Examples 3 to 5.

Hereinafter, the present invention will be described in detail including examples.

The present invention aims to minimize side reactions by heat even after the growth reaction is completed by adding the initiator used in the polymerization of the existing vinyl aromatic hydrocarbon-conjugated diene block copolymer and the Lewis acid which stabilizes the anion at the end of the chain during the initiation and growth reaction.

The side reactions are not easy to control in the conventional anionic polymerization method, and can only be controlled in a relatively low solids process with a very low solids content or a reaction maximum temperature of 100 ° C. or less, thereby improving the polymerization productivity.

In order to increase productivity, the hydrogen desorption reaction proceeds in several side reactions, thereby lowering the activity of the polymer chain terminal, thereby decreasing the coupling efficiency in the polymerization of the coupling. In the case of the polymer produced by this thermal termination reaction, By combining to generate a much higher molecular weight than the target molecular weight, it becomes impossible to produce the designed block copolymer, overcoming this can easily produce the copolymer as designed.

Method for producing a vinyl aromatic hydrocarbon-conjugated diene block copolymer by using a coupling polymerization with improved ion stability according to the present invention

(A) polymerizing a vinyl aromatic hydrocarbon monomer with a polymerization initiator of an organolithium compound in a hydrocarbon solvent to form a first mixed solution comprising a vinyl aromatic hydrocarbon block; and

Adding a conjugated diene monomer to the first mixed solution of step (a) to form a conjugated diene block at the end of the vinyl aromatic hydrocarbon block to form a second mixed solution containing the vinylaromatic hydrocarbon block-conjugated diene block (b) ;

In the manufacturing method of a vinyl aromatic hydrocarbon-conjugated diene block copolymer containing,

(C) adding the Lewis acid to the first mixed solution before the start of the polymerization of the vinyl aromatic hydrocarbon monomer of step (a), during the polymerization or upon completion of the polymerization; And

A silane compound or an epoxy compound, which is a coupling agent, is added to the second mixed solution of step (b) to cause a coupling reaction.

Forming a vinyl aromatic hydrocarbon-conjugated diene block copolymer having a number average molecular weight of 5,000 to 500,000 and a content of the vinyl aromatic hydrocarbon block of 5 to 50% by weight based on 100% by weight of the vinyl aromatic hydrocarbon-conjugated diene block copolymer ( d);

The Lewis acid may be added between the completion of the polymerization of the vinyl aromatic hydrocarbon monomer of step (a) and the termination of the polymerization of the conjugated diene monomer of step (b), more preferably the step (a) It is added within the range between the completion of the polymerization of the vinyl aromatic hydrocarbon monomer of c) to the addition of the conjugated diene monomer of the step (b), in this case there is no reduction in the polymerization rate has an excellent productivity and economic efficiency.

 Step (a)

First, a method of preparing a vinyl aromatic hydrocarbon-conjugated diene block copolymer according to the present invention comprises polymerizing a vinyl aromatic hydrocarbon monomer with a polymerization initiator of an organolithium compound in a hydrocarbon solvent to include a first vinyl aromatic hydrocarbon block (vinyl aromatic hydrocarbon polymer). Forming a mixed solution (a).

Here, the hydrocarbon solvent may be selected and used among solvents commonly known for anionic polymerization. Specifically, alkyl substitutions such as cyclic aliphatic hydrocarbons such as cyclopentane, cyclohexane or cycloheptane, benzene, naphthalene, toluene, and xylene Linear or branched aliphatic hydrocarbon solvents such as aromatic hydrocarbon-based, pentane, hexane, heptane, and octane, and the like, and preferably, cyclohexane, n-hexane and n-heptane may be used alone or in combination. .

In addition, the temperature of each step of the polymerization reaction is possible under the same or different temperature conditions, both constant temperature conditions or adiabatic conditions. The range of possible reaction temperature is -10-150 degreeC, Preferably it is 10-100 degreeC.

Further, as the vinyl aromatic hydrocarbon monomer, styrene, alpha methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-propylstyrene, 1-vinylnaphthalene, 4-cyclohexylstyrene, 4- (p-methylphenyl) styrene, or 1 -Vinyl-5 hexyl naphthalene can be used individually or in combination of 2 or more types.

In addition, as an anionic polymerization initiator used for this invention as an organolithium compound which is a polymerization initiator, if it is an organic alkali metal compound, all can be used, Preferably an organolithium compound is used. The organolithium compound is an organolithium compound having a polymerization initiation capability that can be represented by the general formula RLi, and R is one of those commonly used for conventional anion polymerization, such as alkyl, cycloalkyl, aryl, having 1 to 20 carbon atoms. You can choose to use it. As a more preferred organic lithium initiator, n-butyllithium, sec-butyllithium, methyllithium, ethyllithium, isopropyllithium, cyclohexyllithium, allyllithium, vinyllithium, phenyllithium or benzyllithium alone or in combination Can be used.

Step (b)

In the method for preparing a vinyl aromatic hydrocarbon-conjugated diene block copolymer according to the present invention, after the step (a), the conjugated diene monomer is added to the first mixed solution of step (a) to form a conjugated diene block at the end of the vinyl aromatic hydrocarbon block. To form a second mixed solution containing the vinylaromatic hydrocarbon block-conjugated diene block.

Here, as conjugated diene, 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, piperiene, 3-butyl-1,3-octadiene, isoprene, or 2-phenyl-1,3-butadiene May be used alone or in combination of two or more thereof.

Step (c)

The method for preparing a vinyl aromatic hydrocarbon-conjugated diene block copolymer according to the present invention comprises adding Lewis acid to the first mixed solution before the start of polymerization of the vinyl aromatic hydrocarbon monomer of step (a), during the polymerization or upon completion of the polymerization ( c).

The Lewis acid is preferably added between the completion of the polymerization of the vinyl aromatic hydrocarbon monomer of step (a) and the end of the polymerization of the conjugated diene monomer of step (b), more preferably of step (a) It is added within the range between when the polymerization of the vinyl aromatic hydrocarbon monomers is completed and when the conjugated diene monomer is added. In this case, there is no decrease in the polymerization rate, and thus the productivity and economic efficiency are excellent.

Here, as the Lewis acid, a compound represented by the following formula (4) may be used.

[Formula 4]

In Formula 3, M is Mg, B, Al, or Zn in the periodic table,

R ¹³ and R ¹⁴ may each independently be an alkyl group having 1 to 6 carbon atoms, an aryl group having 5 to 18 carbon atoms, or an alkylaryl group having 6 to 30 carbon atoms,

k and l are each independently an integer of 0 to 3, and 2 ≦ k + l ≦ 3.

Here, as the Lewis acid, diethylmagnesium, di-n-propylmagnesium, di-isopropylmagnesium, dibutylmagnesium, triethylaluminum, tri-isobutylaluminum, tri-n-propylaluminum, tri-n- Hexyl aluminum, diethyl aluminum monohydride, diisobutyl aluminum monohydride, diethylzinc, di-n-propyl zinc, di-isoamyl zinc, di-isobutyl zinc, triethylborane, tri-sec-butyl Borane, tributyl borane, trimethyl borane, or triphenyl borane can be used individually or in combination of 2 or more types.

Step (d)

In the method for producing a vinyl aromatic hydrocarbon-conjugated diene block copolymer according to the present invention, a silane compound or an epoxy compound, which is a coupling agent, is added to the second mixed solution of step (b) for coupling reaction, whereby the number average molecular weight is 5,000 to 500,000. And forming a vinyl aromatic hydrocarbon-conjugated diene block copolymer having a content of a vinyl aromatic hydrocarbon block in an amount of 5 to 50 wt% based on 100 wt% of the vinyl aromatic hydrocarbon-conjugated diene block copolymer. .

Here, the silane compound and the epoxy compound which are coupling agents may be compounds represented by the following Chemical Formulas 1, 2 or 3, respectively.

[Formula 1]

In Formula 1, R ¹ and R ² are each independently an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 18 carbon atoms, X may be a halogen group,

m, n, and p are each independently an integer of 0 to 4, and m + n + p = 4.

[Formula 2]

In Formula 2, R ³ may be an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 24 carbon atoms, or an alkylaryl group having 7 to 30 carbon atoms,

q and r are each independently an integer of 0 to 4, and 2 ≦ q + r ≦ 4.

[Formula 3]

In Formula 3, R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , and R ¹² represent an alkylene group (bivalent) or an alkyl group (monovalent) having 1 to 20 carbon atoms , An arylene group or an aryl group having 6 to 24 carbon atoms, or an alkylarylene group, an arylalkylene group or an alkylaryl group having 7 to 30 carbon atoms, s is 1, t and u are each independently an integer of 0 to 1, 1 ≦ s + t + u ≦ 3. In addition, v, w, and x are each independently an integer of 1-6, and 2 <= v + w + x <6.

Here, it is preferable to use a silane compound as a coupling agent, and the molar ratio of a Lewis acid / organic lithium compound is 0.05-0.2, and to use silane tetrachloride, methyl trichloride, or dimethyl silane alone or in combination of 2 or more types. More preferred.

Herein, when the molar ratio of the Lewis acid / organic lithium compound is less than 0.05, the stability of the polymer terminal ions is similar to that when no Lewis acid is added, which is not preferable when the molar ratio is less than 0.05. When used, the content of the triblock copolymer is less than 10%, which is not preferable for the preparation of the triblock copolymer.

On the other hand, it is preferable that the molar ratio of a Lewis acid / organic lithium compound is 0.05-4, and an epoxy compound is used as a coupling agent, More preferably, molar ratio is 0.1-0.75. 1,2,7,8-diepoxyoctane, diglycidyl-1,4-butanediol, bisphenol A diglycidyl ether, or bisphenol F diglycidyl ether, epoxidized soybean oil and epoxy as epoxy compounds It is more preferable to use the rinsed oil, alone or in combination of two or more. Herein, when the molar ratio of the Lewis acid / organic lithium compound is less than 0.05, the stability of the polymer terminal ions is similar to that when no Lewis acid is added. If it exceeds 4, the polymerization reaction does not proceed and is not preferable.

Hereinafter, preferred examples are provided to aid the understanding of the present invention, but the following examples are merely for exemplifying the present invention, and it will be apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention. It is natural that such variations and modifications fall within the scope of the appended claims.

EXAMPLE

The polymerization method of the vinylaromatic hydrocarbon-conjugated diene block copolymer is briefly described as follows.

In a reactor containing an organic lithium and a hydrocarbon solvent, vinyl aromatic hydrocarbon is added and waited until at least 99% of the vinyl aromatic hydrocarbon monomer is consumed, and then conjugated diene monomer is introduced into the reactor and polymerization is performed until the consumption of conjugated diene monomer is at least 99%. After proceeding to the coupling agent was added to prepare a linear or radial block copolymer through a coupling reaction.

At this time, when the Lewis acid for stabilizing the ions at the end of the chain is introduced during the initiation or growth reaction, before the polymerization is initiated with organolithium or during the polymerization of the vinyl aromatic hydrocarbon monomer or when the polymerization of the vinyl aromatic hydrocarbon monomer is terminated, The conjugated diene monomer is added until the end of the polymerization. Thereafter, a reaction terminator such as water or alcohol was added to the reactor to prepare a polymer in which the activity of the active polymer was removed.

Example 1

Example 1 of the present invention is a polymerization process using a coupling polymerization method and adding Lewis acid to improve the ion stability of the vinyl aromatic hydrocarbon-conjugated diene block copolymer.

Using a styrene and butadiene as a monomer, a triblock copolymer having a weight ratio of 31/69 was prepared as follows.

4256 g of cyclohexane as a solvent and 330 g of styrene were added to a 10 L reactor filled with nitrogen, and 1.4 g of n-butyllithium was added at a temperature of 65 ° C. to polymerize styrene. After styrene polymerization, 0.37 g of triisobutylaluminum was added and completely dispersed, followed by administration of 734 g of butadiene monomer to produce butadiene block at the end of the polymerized styrene block.

After completion of the butadiene polymerization, dimethyl dichloride was administered in the amount shown in Table 2 to proceed the coupling reaction, and then 0.33 g of water was administered to terminate the polymerization reaction. 0.4 parts by weight of antioxidant Irganox 1076 (Ciba) and 0.9 parts by weight of trisnonyl phenyl phosphite (intrinsic chemical, TNPP) were added as additives to the polymerization solution.

Example 2

In Example 1, the amount of triisobutyl aluminum was increased to 1.81 g, and the coupling agent was used in the same manner as in Example 1, except that 1,2,7,8-diepoxyoctane was used.

Comparative Example 1

A triblock copolymer was prepared in the same manner as in Example 1, except that triisobutyl aluminum, which is an ion stability improving agent, was not added in Example 1.

Comparative Example 2

A copolymer was prepared in the same manner as in Example 1, except that the amount of triisobutyl aluminum was increased to 1.81 g in Example 1.

Comparative Example 3

In Comparative Example 2, tri-butyl aluminum, which is an ion stability improving agent, was added before styrene reaction, and triple block air was prepared in the same manner as in Comparative Example 2, except that methyl trichloride was used as a coupling agent instead of dimethyl dichloride. The coalescence was prepared.

The polymerization parameters in the polymerization of Comparative Examples 1, 2 and 3 and the final styrene-butadiene-styrene block copolymers prepared in Examples 1 and 2 are described in Table 1, and the respective polymers were analyzed by gel permeation chromatography. 1 is a gel permeation chromatography profile of the Table 2 examples.

Gel permeation chromatography was used to compare the molecular weight, molecular weight distribution, and profile of the copolymer, THF was used as the solvent, and the temperature was measured at 40 ° C. at a rate of 1 ml / min.

* Number average molecular weight measurement method-was measured using a gel permeation chromatography instrument.

* Side reaction generation rate (%)-The ratio of the area where the macromolecular weight generated by the side reaction and the area where the coupled molecular weight was generated in the gel permeation chromatography profile was determined by the% method (× 100).

Coupling efficiency (%) — The area ratio of the uncoupled molecular weight to the uncoupled molecular weight area was determined by the% method.

Table 1

Item	[Al] / [Li] molar ratio	Coupling agent	Reaction temperature and pressure (℃) / (bar)	Reaction time	Temperature change (℃)	Input change (bar)
Comparative Example 1	0	Dimethyl silane dichloride	137.10 / 5.5	10'07 "	71.85	4.0
Example 1	0.10	Dimethyl silane dichloride	135.50 / 5.5	11'25 "	70.65	4.3
Comparative Example 2	0.5	Dimethyl silane dichloride	134.47 / 4.9	10'50 "	69.52	3.7
Comparative Example 3	0.5	Methylsilane Trichloride	135.68 / 5.5	16'18 "	70.77	4.3
Example 2	0.5	1,2,7,8-diepoxyoctane	135.50 / 5.4	10'25 "	70.32	4.2

As can be seen in Table 1, the change in the reaction temperature of the embodiment was obtained about the effect of about 1.6 ~ 2.6 ℃ lowered. The overall reaction time of the Example is delayed by about 0.5 to 1 minute compared to the comparative example, but it is seen that the difference in the reaction rate is not large. On the other hand, when Lewis acid was added before the styrene reaction as in Comparative Example 3, the reaction time was delayed by about 5 to 6 minutes, and only about 60% of the reaction time was increased. Therefore, the addition of Lewis acid after the styrene reaction can be regarded as the right time to add the polymer without lowering the polymerization rate.

TABLE 2

	[Al] / [Li] molar ratio	Coupling agent	[Coupling Agent] / [Li] Molar Ratio	Side reaction rate (%)	Molecular Weight of Coupled SBS (kg / mol)	Coupling Efficiency (%)
Comparative Example 1	0	Dimethyl silane dichloride	1.04	11.5	115.1k	55.4
Example 1	0.10	Dimethyl silane dichloride	1.04	-	110.8k	56.1
Comparative Example 2	0.5	Dimethyl silane dichloride	1.20	-	115.4.k	8.3
Comparative Example 3	0.5	Methylsilane Trichloride	0.79	-	109.1k	35.09
Example 2	0.5	1,2,7,8-diepoxyoctane	1.06	-	111.8k	57.5

In Table 2, it can be seen that the coupling efficiency at the molar ratio of aluminum / lithium of 0 to 0.1 is almost the same level. Referring to FIG. 1, Comparative Example 1 produced a polymer of 11.5% and added aluminum. It can be seen that in 1, 2 and Comparative Examples 2 and 3, almost no generation was made.

In Comparative Example 2, when the ratio of aluminum / lithium is increased from 0.1 to about 0.5, the coupling efficiency is drastically reduced from about 56% to 8.3%, which is due to an increase in stability through an aluminum compound in which the anion at the end of the polymer chain is Lewis acid. It means that the reactivity with methyl dichloride silane is lowered, which means that it is not suitable as a coupling agent in this case.

On the other hand, in Comparative Example 3, the aluminum / lithium ratio is similar to that of Comparative Example 2, but when methyl trichloride is used, the coupling efficiency is increased by about 28% from 8.3% to 36.5%, compared to methyl dichloride. In comparison, the use of halogen silane as a coupling agent is still not suitable as a coupling agent in a system having an aluminum / lithium ratio of 0.1 equivalent or more, because the coupling efficiency is still about 20%.

In Example 2, the coupling agent was changed to 1,2,7,8-diepoxy octane, which was epoxy, and the coupling efficiency was 57.5% despite the molar ratio of aluminum / lithium similar to those of Comparative Examples 2 and 3. It can be found that the coupling agent is epoxy based when the content of the ion stability improver is increased.

Examples 3 to 5

A copolymer was prepared in the same manner as in Example 2, but diglycidyl-1,4-butanediol, bisphenol A diglycidyl ether, and bisphenol F diglycidyl ether were used as coupling agents.

Table 3 and Figure 2 show the gel permeation chromatography analysis results and profiles of Examples 3 to 5, respectively.

TABLE 3

	[Al] / [Li] molar ratio	Coupling agent	[Coupling Agent] / [Li] Molar Ratio	Side reaction rate (%)	Molecular Weight of Coupled SBS (kg / mol)	Coupling Efficiency (%)
Example 3	0.5	Diglycidyl-1,4-butanediol	1.24	-	116.5k	71.4
Example 4	0.5	Bisphenol A diglycidyl ether	0.99	-	97.9k	74.3
Example 5	0.5	Bisphenol F diglycidyl ether	1.04	-	102.6k	63.5

According to the gel permeation chromatography results of Table 3 and Figure 2, it can be seen that the coupling efficiency is improved by about 8 to 19% in all of Examples 3 to 5 compared to the epoxy coupling agent used in Example 2. It is possible to use the coupling polymerization method for the polymerization of block copolymers by using Lewis acid which can improve ion stability by using an appropriate coupling agent. It means that the coupling efficiency can be increased by suppressing other side reactions. Therefore, according to the manufacturing method of the block copolymer of the present invention, it is possible to polymerize by raising the solid content in the solution during the polymerization and precisely control the molecular weight and molecular weight distribution of the block copolymer.

In addition, when the Lewis acid is not used as in Comparative Example 1, the coupling efficiency is poor and the side reactions are increased, so that the physical properties are improved by including about 10 to 15% of the molecular weight, which is about 2 times the desired molecular weight, but the solution viscosity of the product is improved. Will rise. Therefore, since the high molecular weight produced by this side reaction during the polymerization must be reflected, the factor to be controlled is increased, so that it is not easy to produce the designed target viscosity and molecular weight during the polymerization.

On the other hand, in the embodiment according to the present invention, since the high molecular weight due to the side reaction is hardly generated, only the target molecular weight needs to be adjusted during polymerization, so that a block copolymer having a designed target viscosity and molecular weight can be prepared.

Claims (17)

1. (A) polymerizing a vinyl aromatic hydrocarbon monomer with a polymerization initiator of an organolithium compound in a hydrocarbon solvent to form a first mixed solution comprising a vinyl aromatic hydrocarbon block; and

   Adding a conjugated diene monomer to the first mixed solution of step (a) to form a conjugated diene block at the end of the vinyl aromatic hydrocarbon block to form a second mixed solution containing a vinylaromatic hydrocarbon block-conjugated diene block (b) In the manufacturing method of the vinyl aromatic hydrocarbon-conjugated diene block copolymer containing,

   And (c) adding the Lewis acid to the first mixed solution before the start of the polymerization of the vinyl aromatic hydrocarbon monomer of step (a), during the polymerization, or upon completion of the polymerization. Method of Preparation of Copolymer.
2. The method of claim 1,

   The molar ratio (mole number of Lewis acid / mole number of organic lithium compound) of the said Lewis acid and an organolithium compound is 0.05-4, The manufacturing method of the vinyl aromatic hydrocarbon-conjugated diene block copolymer.
3. The method of claim 1,

   A coupling agent was added to the second mixed solution of step (b) to cause a coupling reaction, wherein the vinyl aromatic hydrocarbon block content was 5 to 50 wt% based on 100 wt% of the vinyl aromatic hydrocarbon-conjugated diene block copolymer. Forming a hydrocarbon-conjugated diene block copolymer (d); Method of producing a vinyl aromatic hydrocarbon-conjugated diene block copolymer comprising a.
4. The method of claim 3,

   The coupling agent is a method for producing a vinyl aromatic hydrocarbon-conjugated diene block copolymer, characterized in that the silane compound or an epoxy compound.
5. The method of claim 4, wherein

   When the coupling agent is a silane compound, the molar ratio (mole number of Lewis acid / mole number of organic lithium compound) of the Lewis acid and the organolithium compound is 0.05 to 0.2, characterized in that the manufacturing method of the vinyl aromatic hydrocarbon-conjugated diene block copolymer.
6. The method of claim 4, wherein

   When the coupling agent is an epoxy compound, the molar ratio (mole number of Lewis acid / mole number of organic lithium compound) of the Lewis acid and the organolithium compound is 0.05 to 4, characterized in that the manufacturing method of the vinyl aromatic hydrocarbon-conjugated diene block copolymer.
7. The method of claim 1,

   The vinyl aromatic hydrocarbon-conjugated diene block copolymer has a number average molecular weight of 5,000 to 500,000.
8. The method according to claim 4 or 5,

   The silane compound is a method for producing a vinyl aromatic hydrocarbon-conjugated diene block copolymer, characterized in that the compound represented by the formula (1).

   [Formula 1]

   

   In Formula 1, R ¹ and R ² are each independently an alkyl group having 1 to 6 carbon atoms, or an aryl group having 5 to 18 carbon atoms, X may be a halogen group, m, n, and p are each independently 0 to It is an integer of 4, and m + n + p = 4.
9. The method of claim 4, wherein

   The epoxy compound is a method for producing a vinyl aromatic hydrocarbon-conjugated diene block copolymer, characterized in that the compound represented by the formula (2) or (3), respectively.

   [Formula 2]

   

   In Formula 2, R ³ may be an alkyl group having 1 to 20 carbon atoms, an aryl group having 5 to 24 carbon atoms, or an alkylaryl group having 6 to 30 carbon atoms,

   q and r are each independently an integer of 0 to 4, and 2 ≦ q + r ≦ 4.

   [Formula 3]

   

   In Formula 3, R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , and R ¹² represent an alkylene group or alkyl group having 1 to 20 carbon atoms, an arylene group having 5 to 24 carbon atoms, or aryl Or an alkylarylene group or an alkylaryl group having 6 to 30 carbon atoms, and s is 1, t and u are each independently an integer of 0 to 1, and 1 ≦ s + t + u ≦ 3. In addition, v, w, and x are each independently an integer of 1-6, and 2 <= v + w + x <6.
10. The method according to claim 1 or 2,

    The Lewis acid is a method for producing a vinyl aromatic hydrocarbon-conjugated diene block copolymer, characterized in that the compound represented by the following formula (4).

    [Formula 4]

    

    In Formula 3, M is Mg, B, Al, or Zn in the periodic table,

    R ¹³ and R ¹⁴ may each independently be an alkyl group having 1 to 6 carbon atoms, an aryl group having 5 to 18 carbon atoms, or an alkylaryl group having 6 to 30 carbon atoms, and k and l are each independently an integer of 0 to 3, 2≤k + l≤3.
11. The method of claim 10,

    The Lewis acid is diethylmagnesium, di-n-propylmagnesium, di-isopropylmagnesium, dibutylmagnesium, triethylaluminum, tri-isobutylaluminum, tri-n-propylaluminum, tri-n-hexylaluminum, diethyl Aluminum monohydride, diisobutyl aluminum monohydride, diethylzinc, di-n-propyl zinc, di-isoamyl zinc, di-isobutyl zinc, triethylborane, tri-sec-butylborane, tributylborane The method for producing a vinyl aromatic hydrocarbon-conjugated diene block copolymer, characterized in that at least one member selected from the group consisting of trimethylborane, and triphenylborane.
12. The method of claim 4, wherein

    When the coupling agent is a silane compound, the molar ratio (mole number of Lewis acid / mole number of organic lithium compound) of the Lewis acid and the organolithium compound is 0.05 to 0.1, characterized in that the manufacturing method of the vinyl aromatic hydrocarbon-conjugated diene block copolymer.
13. The method of claim 4, wherein

    The silane compound is a method for producing a vinyl aromatic hydrocarbon-conjugated diene block copolymer, characterized in that at least one selected from the group consisting of silane tetrachloride, methyl trichloride, and dimethyl dichloride.
14. The method of claim 4, wherein

    The molar ratio (mole number of Lewis acid / mole number of organic lithium compound) of said Lewis acid and an organolithium compound when the said coupling agent is an epoxy compound is 0.1-0.75, The manufacturing method of the vinyl aromatic hydrocarbon conjugated diene block copolymer.
15. The method of claim 4, wherein

    The epoxy compounds include 1,2,7,8-diepoxyoctane, diglycidyl-1,4-butanediol, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, epoxidized soybean oil oil and epoxy Method for producing a vinyl aromatic hydrocarbon-conjugated diene block copolymer, characterized in that at least one member selected from the group consisting of rinsed rinsing oil.
16. The method of claim 1,

    The vinyl aromatic hydrocarbon monomers include styrene, alpha methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-propylstyrene, 1-vinylnaphthalene, 4-cyclohexylstyrene, 4- (p-methylphenyl) styrene, and 1- A vinyl aromatic hydrocarbon-conjugated diene block copolymer, characterized in that at least one member selected from the group consisting of vinyl-5hexyl naphthalene.
17. The method of claim 1,

    The conjugated diene is 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, piperiene, 3-butyl-1,3-octadiene, isoprene, and 2-phenyl-1,3-butadiene Method for producing a vinyl aromatic hydrocarbon-conjugated diene block copolymer, characterized in that at least one member selected from the group consisting of.

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