阅读说明：本技术 嵌段共聚物组合物，其制备方法以及包含其的沥青组合物 (Block copolymer composition, method for preparing the same, and asphalt composition comprising the same ) 是由 李世卿 金泰中 金贤禹 李圣斗 李春和 于 2019-11-20 设计创作，主要内容包括：本发明提供了一种嵌段共聚物组合物,更具体而言,一种包括二嵌段共聚物和三嵌段共聚物的嵌段共聚物组合物,其中该二嵌段共聚物包括含有由基于第一共轭二烯的单体衍生的重复单元的第一嵌段和含有由第一乙烯基芳香族单体衍生的重复单元的第二嵌段,并且在二嵌段共聚物的一端包含由通过化学式1(参见本发明的说明书)表示的改性引发剂衍生的官能团,本发明还提供了其制备方法,以及包含其的沥青组合物。(The present invention provides a block copolymer composition, more specifically, a block copolymer composition comprising a diblock copolymer and a triblock copolymer, wherein the diblock copolymer comprises a first block comprising a repeating unit derived from a first conjugated diene-based monomer and a second block comprising a repeating unit derived from a first vinyl aromatic monomer, and comprises a functional group derived from a modification initiator represented by chemical formula 1 (see the description of the present invention) at one end of the diblock copolymer, a preparation method thereof, and a asphalt composition comprising the same.)

1. A block copolymer composition comprising a diblock copolymer and a triblock copolymer,

wherein the diblock copolymer comprises a first block comprising repeating units derived from a first conjugated diene-based monomer and a second block comprising repeating units derived from a first vinyl aromatic monomer, and

the diblock copolymer includes a functional group derived from a modification initiator represented by the following chemical formula 1 at one end thereof:

[ chemical formula 1]

Wherein R is₁Is a hydrocarbon group having 1 to 20 carbon atoms; r₂Is an alkylene group having 1 to 30 carbon atoms; and R₃And R₄Independently of one another, hydrogen or alkyl having 1 to 30 carbon atoms.

2. The block copolymer composition of claim 1, wherein the block copolymer composition comprises from 25 to 42 weight percent diblock copolymer and from 58 to 75 weight percent triblock copolymer.

3. The block copolymer composition of claim 1, wherein the block copolymer composition comprises from 30 to 35 weight percent diblock copolymer and from 65 to 70 weight percent triblock copolymer.

4. The block copolymer composition of claim 1, wherein R₁Is a hydrocarbyl group having 2 to 8 carbon atoms; r₂Is an alkylene group having 1 to 8 carbon atoms; and R₃And R₄Independently of one another, hydrogen or alkyl having 1 to 8 carbon atoms.

5. The block copolymer composition of claim 1, wherein the modification initiator represented by chemical formula 1 is a modification initiator represented by the following chemical formula 2 or chemical formula 3,

[ chemical formula 2]

[ chemical formula 3]

6. The block copolymer composition of claim 1, wherein the triblock copolymer comprises a third block comprising repeat units derived from a second vinyl aromatic monomer, a fourth block comprising repeat units derived from a second conjugated diene-based monomer, and a linking group derived from a coupling agent.

7. The block copolymer composition of claim 1, wherein the coupling efficiency of the block copolymer composition is 62 to 79%.

8. The block copolymer composition of claim 1, wherein the coupling efficiency of the block copolymer composition is 65% to 67%.

9. A method of preparing a block copolymer composition, the method comprising:

preparing a first block comprising a repeating unit derived from a first conjugated diene-based monomer in the presence of a modification initiator represented by the following chemical formula 1;

polymerizing a second block comprising repeating units derived from a first vinyl aromatic monomer in the presence of the previously prepared first block to prepare a diblock copolymer;

preparing a triblock copolymer; and

mixing diblock copolymer and triblock copolymer:

[ chemical formula 1]

Wherein R is₁Is a hydrocarbon group having 1 to 20 carbon atoms; r₂Is an alkylene group having 1 to 30 carbon atoms; and R₃And R₄Independently of one another, hydrogen or alkyl having 1 to 30 carbon atoms.

10. The method of making a block copolymer composition of claim 9, wherein the block copolymer composition comprises 25 to 42 weight percent diblock copolymer and 58 to 75 weight percent triblock copolymer.

11. A bituminous composition comprising a block copolymer composition according to any one of claims 1 to 8 and a bitumen.

12. The asphalt composition of claim 11, wherein the asphalt composition comprises from 1 to 10 parts by weight of the block copolymer composition, based on 100 parts by weight total of the asphalt composition.

Technical Field

The present invention relates to a block copolymer composition, and more particularly, to a block copolymer composition useful as an asphalt modifier, a method for preparing the same, and an asphalt composition comprising the same.

Background

Bitumen is the residue remaining after evaporation of most volatile fractions from crude oil components, which remains a highly viscous liquid or semi-solid at elevated temperatures, but has hardened physical properties at or below room temperature. In addition, since asphalt is very plastic, highly waterproof, has high electrical insulation, adhesive properties, etc., and has chemical stability, it is widely used in building materials such as road pavement materials or waterproof materials. However, asphalt has the following problems: when asphalt is exposed to high temperature for a long time during its use, plastic deformation occurs, and cracks are generated due to external impact at low temperature.

In order to solve this problem, recently, studies have been made to improve the physical properties of asphalt by adding various polymers.

For example, there is a method of improving physical properties of asphalt compositions using a vinyl aromatic hydrocarbon-conjugated diene copolymer such as styrene-butadiene-styrene (SBS) copolymer as a modifier or impact enhancer.

In general, compatibility with asphalt is the most fundamental and essential requirement for the use of SBS copolymers in asphalt compositions.

However, due to recent increases in crude oil prices and energy conservation policies, refining facilities are constantly developing and the content of asphaltenes as by-products in the asphalt as a residue of oil refining is increasing. Since asphaltenes, which are aggregates of aromatic hydrocarbons, have many polar functional groups at the ends, they have very low compatibility with SBS copolymers having no polar functional groups. Therefore, the processing time of the asphalt composition is greatly increased, and also deterioration in the quality of asphalt, such as deterioration in the elasticity of the improved asphalt composition, is caused.

In order to solve such problems, there are a method of adjusting the molecular weight of the SBS copolymer, a method of changing the molecular fine structure of the SBS copolymer to increase the coupling effect, a method of adding an additive such as oil used as a processing aid; however, these methods are not the final solution since a separately defined method should be provided for each kind of asphalt having various quality deviations.

Therefore, there is an urgent need to develop SBS copolymers having excellent compatibility with asphalt as an asphalt modifier.

Disclosure of Invention

[ problem ] to provide a method for producing a semiconductor device

The technical problem to be solved by the present invention is to solve the above-mentioned problems in the background art by improving the softening point and solubility of an asphalt composition by including a terminally modified diblock copolymer in a block copolymer composition used as an asphalt modifier.

That is, an object of the present invention is to provide a block copolymer composition that can be used as an asphalt modifier, and to provide an asphalt composition having improved softening point and solubility when asphalt is modified using the block copolymer composition.

[ technical solution ] A

In one general aspect, a block copolymer composition includes a diblock copolymer and a triblock copolymer, wherein the diblock copolymer includes a first block including a repeating unit derived from a first conjugated diene-based monomer and a second block including a repeating unit derived from a first vinyl aromatic monomer, and includes a functional group derived from a modified initiator represented by the following chemical formula 1 at one end of the diblock copolymer:

[ chemical formula 1]

Wherein R is₁Is a hydrocarbon group having 1 to 20 carbon atoms; r₂Is an alkylene group having 1 to 30 carbon atoms; and R₃And R₄Independently of one another, hydrogen or alkyl having 1 to 30 carbon atoms.

In another general aspect, a method of making a block copolymer composition comprises: preparing a first block comprising a repeating unit derived from a first conjugated diene-based monomer in the presence of a modified initiator represented by the following chemical formula 1; and polymerizing a second block comprising a repeating unit derived from the first vinyl aromatic monomer in the presence of the first block prepared in the previous step to prepare a diblock copolymer; preparing a triblock copolymer; and mixing the diblock copolymer and the triblock copolymer.

[ chemical formula 1]

Wherein R is₁Is a hydrocarbon group having 1 to 20 carbon atoms; r₂Is an alkylene group having 1 to 30 carbon atoms; and R₃And R₄Independently of one another, hydrogen or alkyl having 1 to 30 carbon atoms.

In yet another general aspect, a bituminous composition includes a block copolymer composition and a bitumen.

[ PROBLEMS ] the present invention

When the block copolymer composition according to the present invention is used as an asphalt modifier, both the softening point and the solubility of the asphalt composition are improved to excellent levels.

Detailed Description

The terms and words used in the specification and claims of the present invention should not be construed restrictively to have general or dictionary meanings, but should be construed to have meanings and concepts conforming to the technical idea of the present invention on the basis of the principle that the inventors can appropriately define the concepts of the terms to describe their own invention in the best way.

In the present invention, the terms "… … -derived repeating unit", "… … -derived functional group" and "… … -derived linking group" may denote a component or structure derived from one material, or a material itself. As a specific example, "a recurring unit derived from … …" may refer to a recurring unit formed in a polymer by a monomer participating in a polymerization reaction introduced during polymerization, "a functional group derived from … …" may refer to a functional group connected to one end of a recurring unit formed in a polymer by an initiator participating in a polymerization reaction introduced during polymerization, and "a linking group derived from … …" may refer to a linking group connected to each of polymers coupled by a coupling agent participating in a coupling reaction introduced during a coupling reaction of a polymer.

In the present invention, the term "block" may refer to a repeating unit group composed of only repeating units derived from the same monomer, the repeating unit group being formed only from the same monomer participating in polymerization reaction in the copolymer; and as a specific example, the block containing a repeating unit derived from a vinyl aromatic monomer may refer to a block formed only by a repeating unit derived from a vinyl aromatic monomer, and the block containing a repeating unit derived from a conjugated diene-based monomer may refer to a block formed only by a repeating unit derived from a conjugated diene-based monomer.

In the present invention, the terms "diblock copolymer" and "triblock copolymer" may refer to a copolymer containing two or more blocks derived from different monomers.

In the present invention, the term "living polymer" may refer to a polymer formed by anionic polymerization in which one end of the polymer is maintained in an anionic state to allow additional polymerization or reaction, and may refer to a living anionic polymer, as a specific example.

In the present invention, the term "solution" may mean that it comprises, in a hydrocarbon-based solvent, in dispersed or dissolved form therein: polymers, diblock copolymers and block copolymers produced by polymerization or coupling reactions in each step of the process for preparing the block copolymer composition.

< Block copolymer composition >

The block copolymer composition according to the present invention may comprise diblock copolymers and triblock copolymers.

In general, in vinyl aromatic conjugated diene block copolymers, particularly styrene-butadiene-styrene (SBS) triblock copolymers, which are mainly used as asphalt modifiers, factors related to the fine structure of molecules, such as the contents of styrene blocks and butadiene blocks and the content of vinyl groups present in the conjugated diene blocks, are correlated with each other, and therefore, when physical properties at high temperatures are improved, physical properties at low temperatures are reduced, and when the dissolution rate is increased, mechanical physical properties are reduced, and problems such as gel formation in asphalt compositions during sulfur crosslinking occur. However, the block copolymer composition according to the present invention includes a diblock copolymer including a functional group derived from a modified initiator at one end, and a triblock copolymer, thereby having the effect of improving a softening point and solubility, adjusting a molecular weight of the triblock copolymer or changing a fine structure of a molecule without introducing an additive.

The diblock copolymer included in the block copolymer according to the present invention may include a first block including a repeating unit derived from the first conjugated diene-based monomer and a second block including a repeating unit derived from the first vinyl aromatic monomer, wherein a functional group derived from the modified initiator represented by the following chemical formula 1 is included at one end of the diblock copolymer. Meanwhile, the one end may be one end of the first block of the diblock copolymer.

[ chemical formula 1]

Wherein R is₁Is a hydrocarbyl group having 1 to 20 carbon atoms, 1 to 15 carbon atoms, or 2 to 8 carbon atoms; r₂Is an alkylene group having 1 to 30 carbon atoms, 1 to 20 carbon atoms, or 1 to 8 carbon atoms; and R₃And R₄Independently of one another, hydrogen or an alkyl group having 1 to 30 carbon atoms, 1 to 20 carbon atoms, or 1 to 8 carbon atoms.

The first block of the diblock copolymer comprising repeat units derived from the first conjugated diene-based monomer may be a block formed by polymerization of the first conjugated diene-based monomer. The first conjugated diene-based monomer for forming the first block may be one or more selected from the group consisting of 1, 3-butadiene, 2, 3-dimethyl-1, 3-butadiene, piperylene, 3-butyl-1, 3-octadiene, isoprene, 2-phenyl-1, 3-butadiene and 2-halo-1, 3-butadiene (where halo means a halogen atom). The content of the repeating unit derived from the first conjugated diene-based monomer may be 60 to 80 parts by weight, 65 to 75 parts by weight, or 67 to 73 parts by weight, based on 100 parts by weight of the total diblock copolymer. Within this range, when the block copolymer composition comprising a diblock copolymer is used as the asphalt modifier, there is an effect of improving the softening point and solubility of the asphalt composition.

In addition, the second block of the diblock copolymer, which includes a repeating unit derived from the first vinyl aromatic monomer, may be a block formed by polymerization of the first vinyl aromatic monomer. The first vinyl aromatic monomer for forming the second block may be one or more selected from the group consisting of styrene, α -methylstyrene, 3-methylstyrene, 4-propylstyrene, 1-vinylnaphthalene, 4-cyclohexylstyrene, 4- (p-methylphenyl) styrene, and 1-vinyl-5-hexylnaphthalene. The content of the repeating unit derived from the first vinyl aromatic monomer may be 20 to 40 parts by weight, 25 to 35 parts by weight, or 27 to 33 parts by weight, based on 100 parts by weight of the diblock copolymer in total. Within this range, when the block copolymer composition comprising a diblock copolymer is used as the asphalt modifier, there is an effect of improving the softening point and solubility of the asphalt composition.

Meanwhile, in order to further improve the softening point and solubility of the asphalt composition comprising the diblock copolymer composition, a functional group derived from a modification initiator represented by the following chemical formula 1 may be included at one end of the diblock copolymer, as a specific example, at one end of the first block:

[ chemical formula 1]

Wherein R is₁Is a hydrocarbyl group having 1 to 20 carbon atoms, 1 to 15 carbon atoms, or 2 to 8 carbon atoms; r₂Is an alkylene group having 1 to 30 carbon atoms, 1 to 20 carbon atoms, or 1 to 8 carbon atoms; and R₃And R₄Independently of one another, hydrogen or an alkyl group having 1 to 30 carbon atoms, 1 to 20 carbon atoms, or 1 to 8 carbon atoms.

As a specific example, the modification initiator represented by chemical formula 1 may be represented by the following chemical formulae 2 and 3:

[ chemical formula 2]

[ chemical formula 3]

The modification initiator of the functional group derived from the modification initiator may be a modification initiator prepared by modifying to a benzylamine-based compound to improve the softening point and solubility of the asphalt composition. When the functional group derived from the benzylamine-based compound is located at one end of the diblock copolymer, there is an effect of increasing the affinity between the polar group present in the asphalt and the functional group derived from the modification initiator, thereby improving the solubility of the diblock copolymer containing the functional group in the asphalt. The improvement in the solubility of the diblock copolymer contributes to chain relaxation of the triblock copolymer included together in the block copolymer composition, thereby having the effect of improving the overall solubility of the block copolymer composition. In addition, after the diblock copolymer is dissolved in asphalt, a reaction between functional groups derived from the benzylamine-based compound in the diblock copolymer may occur due to high temperature (180 ℃ or more) in the asphalt, and the diblock copolymer that has undergone the reaction is modified into a triblock copolymer form or a form in which a plurality of diblock copolymers are bonded, thereby increasing the high molecular content and contributing to improvement of physical properties. Therefore, when a block copolymer including a diblock copolymer including a functional group derived from a modification initiator at one end is used as the asphalt modifier, there is an effect of improving the softening point and solubility of the asphalt composition.

In addition, in the benzylamine-based compound, the modification initiator may be those substituted with a vinyl group, and thus, the modification initiator may be used to initiate polymerization during the preparation of the diblock copolymer, and, in the final step of the reaction, to perform gelation interactions, such as between functional groups derived from the modification initiator, including hydrogen bonds and covalent bonds.

That is, the modification initiator according to the present invention is used as an initiator, and the end of the diblock copolymer prepared using the modification initiator can be effectively modified. Therefore, since the modification to the triblock copolymer form or the form in which a plurality of diblock copolymers are bonded by the interaction between functional groups derived from the modification initiator occurs without introducing a coupling agent during the preparation of the modified asphalt, there is an effect of increasing the high molecular content and contributing to the improvement of physical properties. Therefore, it has the effect of excellent compatibility with the components contained in the asphalt composition and excellent softening point of the asphalt composition.

The content of the functional group derived from the modification initiator may be 0.248 to 0.322 parts by weight, 0.248 to 0.32 parts by weight, or 0.25 to 0.3 parts by weight, based on 100 parts by weight of the diblock copolymer in total. Within this range, when the block copolymer composition comprising a diblock copolymer is used as the asphalt modifier, there is an effect of improving the softening point and solubility of the asphalt composition.

The triblock copolymer included in the block copolymer composition according to the present invention may include a third block including a repeating unit derived from a second vinyl aromatic monomer, a fourth block including a repeating unit derived from a second conjugated diene-based monomer, and a linking group derived from a coupling agent.

The third block of the triblock copolymer comprising repeating units derived from a second vinyl aromatic monomer may be a block formed by polymerization of a second vinyl aromatic monomer. The second vinyl aromatic monomer for forming the third block may be one or more selected from the group consisting of styrene, α -methylstyrene, 3-methylstyrene, 4-propylstyrene, 1-vinylnaphthalene, 4-cyclohexylstyrene, 4- (p-methylphenyl) styrene, and 1-vinyl-5-hexylnaphthalene, and may be the same as or different from the first vinyl aromatic monomer described above. The content of the repeating unit derived from the second vinyl aromatic monomer may be 20 to 40 parts by weight, 25 to 35 parts by weight, or 27 to 33 parts by weight, based on 100 parts by weight of the triblock copolymer in total. Within this range, when the block copolymer composition comprising a triblock copolymer is used as an asphalt modifier, there is an effect of improving the softening point and solubility of the asphalt composition.

Further, the fourth block of the triblock copolymer including a repeating unit derived from the second conjugated diene-based monomer may be a block formed by polymerization of the second conjugated diene-based monomer. The second conjugated diene-based monomer for forming the fourth block may be one or more selected from the group consisting of 1, 3-butadiene, 2, 3-dimethyl-1, 3-butadiene, piperylene, 3-butyl-1, 3-octadiene, isoprene, 2-phenyl-1, 3-butadiene and 2-halo-1, 3-butadiene (wherein halo means a halogen atom), and may be the same as or different from the first conjugated diene-based monomer described above. The content of the repeating unit derived from the second conjugated diene-based monomer may be 60 to 80 parts by weight, 65 to 75 parts by weight, or 67 to 73 parts by weight, based on 100 parts by weight of the triblock copolymer. Within this range, when the block copolymer composition comprising a triblock copolymer is used as an asphalt modifier, there is an effect of improving the softening point and solubility of the asphalt composition.

The linking group derived from the coupling agent may be a linking group linking blocks comprising a plurality of repeating units derived from the second conjugated diene-based monomer. The coupling agent for forming the linking group derived from the coupling agent may be one or more selected from the group consisting of vinyl group-containing hydrocarbon-based compounds, ester-based compounds, silane-based compounds, polysiloxane-based compounds and polyketones. As specific examples, the coupling agent is a polyfunctional coupling agent, and may be selected from vinyl group-containing hydrocarbon-based compounds such as divinylbenzene; ester-based compounds such as diethyl adipate and glycidyl methacrylate; silane-based compounds such as dimethyldichlorosilane, methyldichlorosilane, methoxysilane, glycidoxypropyltrimethoxysilane and oxydipropylbis (trimethoxysilane); polysiloxane-based compounds, such as α, ω -bis (2-trichlorosilylethyl) polydimethylsiloxane; and polyketone. The content of the linking group derived from the coupling agent may be 0.278 to 0.516, 0.28 to 0.51, or 0.285 to 0.45 parts by weight, based on 100 parts by weight of the triblock copolymer in total. Within this range, the coupling efficiency is increased, and when the block copolymer composition comprising a triblock copolymer is used as an asphalt modifier, there is an effect of improving the softening point of the asphalt composition.

Meanwhile, the diblock copolymer may be present in an amount of 25 to 42 wt%, 30 to 40 wt%, or 30 to 35 wt%, and the triblock copolymer may be present in an amount of 58 to 75 wt%, 60 to 70 wt%, or 65 to 70 wt%, based on the total content of the block copolymer composition. Within this range, when the block copolymer composition is used as an asphalt modifier, it has the effect of improving the softening point and solubility of the asphalt composition.

Here, the coupling efficiency of the block copolymer composition may be 62% to 79%, 62% to 73%, or 65% to 67%, and within this range, it has an effect of improving the softening point and solubility of the asphalt composition, which includes the block copolymer composition according to the present invention as an asphalt modifier.

< method for producing Block copolymer composition >

According to the present invention, a method for preparing a block copolymer composition can be provided. The method of preparing a block copolymer composition according to the present invention may include preparing a diblock copolymer; preparing a triblock copolymer; and mixing the diblock copolymer and the triblock copolymer.

The step of preparing the diblock copolymer may include preparing a first block including a repeating unit derived from a first conjugated diene-based monomer in the presence of a modification initiator represented by the following chemical formula 1; and polymerizing a second block comprising a repeating unit derived from the first vinyl aromatic monomer in the presence of the first block prepared in the previous step to prepare a diblock copolymer.

[ chemical formula 1]

Wherein R is₁Is a hydrocarbyl group having 1 to 20 carbon atoms, 1 to 15 carbon atoms, or 2 to 8 carbon atoms; r₂To be provided withAlkylene of 1 to 30 carbon atoms, 1 to 20 carbon atoms, or 1 to 8 carbon atoms; and R₃And R₄Independently of one another, hydrogen or an alkyl group having 1 to 30 carbon atoms, 1 to 20 carbon atoms, or 1 to 8 carbon atoms.

The modified initiator may be used by reacting a polymerization initiator and a benzylamine-based compound substituted with a vinyl group to prepare the modified initiator represented by chemical formula 1.

As a specific example, the modification initiator of chemical formula 1 is represented by the following chemical formula 2, wherein R₁Derived from butyl, R₂Is methylene, and R₃And R₄Each is methyl. When N, N-dimethylvinylbenzylamine is used as a starting material, N-butyllithium as a polymerization initiator is reacted therewith, and the N-butyllithium is substituted to one end to form a benzylamine-based compound as a living polymer.

[ chemical formula 2]

As another specific example, the modification initiator of chemical formula 1 is represented by the following chemical formula 3, wherein R₁Derived from butyl, R₂Is methylene, and R₃And R₄Each is hydrogen. When vinylbenzylamine is used as a starting material, n-butyllithium as a polymerization initiator is reacted therewith, and the n-butyllithium is substituted to one end to form a benzylamine-based compound as a living polymer.

[ chemical formula 3]

As the polymerization initiator, methyl lithium, ethyl lithium, propyl lithium, sec-butyl lithium, tert-butyl lithium, hexyl lithium, n-decyl lithium, tert-octyl lithium, phenyl lithium, 1-naphthyl lithium, n-eicosyl lithium, 4-butylphenyl lithium, 4-methylphenyl lithium, cyclohexyl lithium, 3, 5-di-n-heptylcyclohexyl lithium, 4-cyclopentyl lithium, naphthyl sodium, naphthyl potassium, alkoxy lithium, alkoxy sodium, alkoxy potassium, lithium sulfonate, sodium sulfonate, potassium sulfonate, lithium amide (lithium amide), sodium amide (sodium amide), potassium amide (potassium amide), lithium isopropylamide (lithium isopropamide), and the like can be used in addition to n-butyl lithium.

The preparation of the modified initiator according to the present invention may be performed at a temperature of 50 ℃ to 70 ℃, 53 ℃ to 68 ℃, or 58 ℃ to 62 ℃ for 5 minutes to 20 minutes, 5 minutes to 15 minutes, or 7 minutes to 12 minutes. Within this range, the reaction rate of the polymerization initiator with the benzylamine-based compound substituted with a vinyl group is high, thereby having the effect of easily preparing the modified initiator.

The molar ratio of the raw material to the polymerization initiator may be 1:0.7 to 1.1, 1:0.75 to 1.1, or 1:0.8 to 1.1 during the preparation reaction of the modification initiator. Within this range, the reaction rate of the polymerization initiator with the benzylamine-based compound substituted with a vinyl group is high, thereby having the effect of easily preparing the modified initiator.

The step of preparing the first block may be a step of preparing a first mono-block polymer solution including a repeating unit derived from the first conjugated diene-based monomer by adding the first conjugated diene-based monomer in the presence of a modification initiator in a hydrocarbon-based solvent, and performing polymerization. The first mono-block polymer solution prepared in the step of preparing the first block includes a polymer for forming a block including a repeating unit derived from a first conjugated diene-based monomer.

The step of polymerizing the second block to prepare a diblock copolymer may be a step of preparing a first diblock copolymer solution including a first block including a repeating unit derived from the first conjugated diene-based monomer and a second block including a repeating unit derived from the first vinyl aromatic monomer by adding the first vinyl aromatic monomer to the first monoblock polymer solution including a repeating unit derived from the first conjugated diene-based monomer prepared in the step of preparing the first block, and performing polymerization. Since the polymer for forming the block is a living anionic polymer in which the end of the polymer is in an anionic living state by polymerization, the step of polymerizing the second block to prepare the diblock copolymer may be performed without introducing a separate polymerization initiator. That is, this step may be a step of preparing a first diblock copolymer solution including a first diblock copolymer, in which a second block according to a first vinyl aromatic monomer introduced during polymerization is formed after a block of a repeating unit derived from a first conjugated diene-based monomer by polymerizing the first vinyl aromatic monomer further introduced from the living anionic polymer.

The step of preparing the triblock copolymer may comprise preparing a triblock copolymer comprising a third block comprising repeat units derived from a second vinyl aromatic monomer, a fourth block comprising repeat units derived from a second conjugated diene-based monomer, and a linking group derived from a coupling agent in a hydrocarbon solvent.

The step of preparing the triblock copolymer may be performed separately from the step of preparing the diblock copolymer, or may be performed simultaneously with or after preparing the diblock copolymer.

The preparation of the triblock copolymer may be performed by, as a specific example, adding a second vinyl aromatic monomer in a hydrocarbon-based solvent in the presence of a polymerization initiator conventionally used in the art and performing polymerization to prepare a second monoblock polymer including a polymer for forming a third block comprising repeating units derived from the second vinyl aromatic monomer; adding a second conjugated diene-based monomer to the polymer solution for forming a third block including repeating units derived from a second vinyl aromatic monomer, prepared in the step of preparing the second mono-block polymer solution, and performing polymerization to prepare a second di-block copolymer solution including a second di-block copolymer including a third block including repeating units derived from a second vinyl aromatic monomer, and a fourth block including repeating units derived from a second conjugated diene-based monomer; and adding a coupling agent to the second diblock copolymer solution prepared in the step of preparing the second diblock copolymer solution and performing a coupling reaction to prepare a triblock copolymer including a third block including a repeating unit derived from a second vinyl aromatic monomer, a fourth block including a repeating unit derived from a second conjugated diene-based monomer, a linking group derived from the coupling agent.

The step of preparing the second mono-block polymer solution may be a step for preparing a second mono-block polymer solution including a polymer for forming a third block including a repeating unit derived from a second vinyl aromatic monomer by initiating a polymerization reaction during polymerization of the tri-block copolymer. The second mono-block polymer solution prepared in the step of preparing the second mono-block polymer solution may include a polymer for forming a block including a repeating unit derived from a second vinyl aromatic monomer.

In addition, the step of preparing the second diblock copolymer solution may be a step of preparing a second diblock copolymer solution including a second diblock copolymer including a third block including a repeating unit derived from the second vinyl aromatic monomer, and a fourth block including a repeating unit derived from the second conjugated diene monomer, by adding a second conjugated diene-based monomer in the presence of a polymer for forming a third block including a repeating unit derived from the second vinyl aromatic monomer contained in the second monoblock polymer solution prepared in the step of preparing the second monoblock polymer and performing polymerization. The second mono-block polymer solution prepared in the step of preparing the second mono-block polymer solution includes a polymer for forming a repeating unit block derived from the second vinyl aromatic monomer, and since the polymer is a living anionic polymer in which the end of the polymer is in an anionic living state in the previous step of preparing the second mono-block polymer solution, the step of preparing the second di-block copolymer can be performed without introducing a separate polymerization initiator. That is, the step of preparing the second diblock copolymer may be a step for preparing the second diblock copolymer by performing a polymerization reaction of a second conjugated diene-based monomer further introduced from the living anionic polymer, wherein after the third block including the repeating unit derived from the second vinyl aromatic monomer, a block according to the second conjugated diene-based monomer introduced in the step of preparing the second diblock copolymer is formed.

In addition, the step of preparing the triblock copolymer may be a step for preparing a solution containing the triblock copolymer to which the diblock copolymer is coupled (i.e., a triblock copolymer) by subjecting the second diblock copolymer contained in the second diblock copolymer solution prepared in the step of preparing the second diblock copolymer to a coupling reaction using a coupling agent. The second diblock copolymer solution prepared in the step of preparing the second diblock copolymer includes the second diblock copolymer, and since the copolymer is a living anionic copolymer in which the terminal of the copolymer, particularly the terminal of the block comprising the repeating unit derived from the second conjugated diene-based monomer, is in an anionic living state by polymerization in the previous step of preparing the second diblock copolymer, depending on the number of functional groups contained in the coupling agent, which may be substituted or added, the functional group of the second coupling agent is substituted by the living anionic copolymer, or a coupling reaction of adding a living anionic polymer to the functional group of the second coupling agent may be performed. That is, the triblock copolymer may be a copolymer in which the second diblock copolymers are linked by a coupling agent depending on the number of functional groups contained in the coupling agent, which may be substituted or added, and as a specific example, two or more second diblock copolymers may be coupled by a linking group derived from the coupling agent, and as a more specific example, two to four second diblock copolymers may be coupled by a linking group derived from the coupling agent.

In addition, the step of preparing the triblock copolymer may optionally further comprise adding water or alcohol to the reactor after the coupling reaction to remove the activity of the polymer in an active state.

According to the present invention, the hydrocarbon-based solvent does not react with the polymerization initiator, and any hydrocarbon-based solvent may be used as long as it is generally used in the anionic polymerization. As specific examples, the hydrocarbon-based solvent may be a linear or branched aliphatic hydrocarbon compound such as butane, n-pentane, n-hexane, n-heptane, or isooctane; cyclic aliphatic hydrocarbon compounds unsubstituted or substituted with an alkyl group, such as cyclopentane, cyclohexane, cycloheptane, methylcyclohexane, or methylcycloheptane; or an aromatic hydrocarbon compound which is unsubstituted or substituted with an alkyl group, such as benzene, toluene, xylene, or naphthalene, and any one or a mixture of two or more thereof may be used.

In addition, the polymerization initiator used in the step of preparing the block copolymer may be one or more selected from the above-mentioned polymerization initiators.

The step of mixing the diblock copolymer and the triblock copolymer may be a step for preparing a block copolymer composition existing in a state in which the diblock copolymer and the triblock copolymer are mixed with each other. The mixing may be performed by mixing each copolymer in a powder form, and in order to uniformly disperse and distribute the diblock copolymer and the triblock copolymer in the block copolymer composition, the mixing may be performed by mixing a solution including the diblock copolymer prepared in the previous step and a solution including the triblock copolymer prepared in the previous step, in which case the dispersibility of the diblock copolymer and the triblock copolymer is excellent and the distribution is uniform, thereby having an effect of excellent balance between physical properties of the asphalt composition including the block copolymer composition.

< asphalt composition >

According to the present invention, there is provided an asphalt composition comprising the block copolymer composition as an asphalt modifier. The asphalt composition may include a block copolymer composition and an asphalt. Here, the block copolymer composition may be included in an amount of 1 to 10 parts by weight, 3 to 8 parts by weight, or 4 to 6 parts by weight, based on 100 parts by weight of the total asphalt composition, and within this range, there is an effect that the solubility of the block copolymer composition in asphalt is excellent and the physical properties of the asphalt composition are excellent.

The asphalt composition may further comprise a crosslinking agent for crosslinking the asphalt composition. The crosslinking agent may be a sulfur compound containing sulfur or iron sulfate, and as a specific example, elemental sulfur (powder), and may be contained in an amount of 0.05 to 3 parts by weight based on a total of 100 parts by weight of the asphalt composition, and within this range, has the effect of maintaining an appropriate crosslinking reaction to improve physical properties at high temperature, as well as elasticity and prevention of gelation.

Additionally, the bitumen may comprise from 1 wt% to 40 wt%, or from 5 wt% to 30 wt% asphaltenes, based on the total weight of the bitumen.

In addition, the asphalt composition may be a construction material such as a pavement material or a waterproof material.

Hereinafter, the present invention will be described in more detail by examples. However, the following examples are provided to illustrate the present invention. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope and spirit of the invention, and the scope of the invention is not limited thereto.