KR20020013709A - Copolymer (Composition) for Modifying Asphalt and Asphalt Compositions - Google Patents

Abstract

PURPOSE: To provide an asphalt composition having excellent solubility in straight asphalt and high storage stability at a high temperature and exhibiting well-balanced elongation, toughness, tenacity and a softening point. CONSTITUTION: The copolymer (composition) for the modification of asphalt contains (a) a block copolymer expressed by general formula (I); A1-B-A2 and (b) a block copolymer expressed by general formula (II); (A1-B-A2)nX at an (a)/(b) weight ratio of (40-100)/(60-0) and has a weight-average molecular weight of 100,000-300,000. The asphalt composition is produced by dissolving the block copolymer composition to straight asphalt.

Description

Copolymer (Composition) for Modifying Asphalt and Asphalt Compositions}

According to the present invention, a block copolymer of an aromatic vinyl compound having a specific structure useful for asphalt modification and a conjugated diene or a composition thereof and the copolymer (composition) is incorporated into straight asphalt, so that the dissolution time is short, so that the processing and handling properties are excellent, and high temperature is achieved. The present invention relates to an asphalt composition having excellent storage stability at and having an excellent balance of elongation, toughness, tenacity and softening point.

Conventionally, straight asphalt is available at low cost and is widely used for road pavement, waterproof sheet, soundproof sheet, vibration control material and the like.

However, since the toughness, adhesive force, softening point, elongation, and the like of the straight asphalt are deteriorated, many studies have been attempted to improve the asphalt added with various copolymer compositions for the purpose of improving such characteristics. As specific examples of such various copolymer compositions, styrene-butadiene random copolymer latex (SBR latex), ethylene-vinyl acetate copolymer (EVA), and ethylene-ethyl acrylate copolymer have conventionally been used. However, although the toughness, adhesive strength, and elongation have been improved to some extent with the addition of such a copolymer, further improvement is desired.

In recent years, it has also been attempted to modify the asphalt by adding a block copolymer (SB block copolymer) of an aromatic vinyl compound and a conjugated diene. For example, for the purpose of improving all the physical properties of asphalt, an asphalt composition comprising a block copolymer having a specific structure using an organic lithium compound as a polymerization initiator using various ether compounds or tertiary amine compounds as a micro structure control agent is added. These various proposals are proposed. That is, Japanese Patent Application Laid-Open No. 47-17319 and Japanese Patent Publication No. 59-36949 include ABA type linear block copolymers and (AB) nX type radial block copolymers alone or in combination. Asphalt modification is disclosed. However, in these examples, it is difficult to say that the balance of elongation, toughness and adhesive force is achieved.

In this situation, as disclosed in Japanese Patent Laid-Open Publication No. Hei 1-254768 and Japanese Patent Laid-Open Publication Hei 5-420, the block air in which the content of the aromatic vinyl compound is limited within a certain range is disclosed. It is reported that coalescence forms an asphalt composition having excellent balance of properties such as elongation, toughness, and adhesion. However, even in these disclosed examples, the balance of properties such as asphalt solubility, storage stability, elongation, toughness, adhesion, softening point, and the like is not sufficient, and development of an asphalt composition having improved the balance of such physical properties is desired.

Currently, in general, a method of increasing the toughness and adhesive strength by ensuring high molecular weight of the block copolymer or increasing the amount of addition to the asphalt, and securing a balance with elongation is used. However, in this method, the dissolution time of the block copolymer to asphalt is considerably longer, and the resulting asphalt dissolution viscosity is significantly higher, resulting in a problem of poor workability.

Thus, attempts to modify the asphalt using the SB block copolymer as described above have not yet been satisfactory, and the modified copolymer having the balance of toughness, adhesion, softening point and elongation of the asphalt is What has not been discovered so far is the reality, and further improvement is desired.

The present invention has been made in the background of the prior art, and by controlling the molecular structure highly, it has excellent solubility in asphalt and excellent storage stability at high temperatures, and has excellent balance in toughness, adhesion, elongation, and softening. An object of the present invention is to provide an asphalt composition that can be used for a waterproof sheet or the like.

The present invention (a) a block copolymer represented by the formula (1), A ₁ -BA ₂ , and

(B) a block copolymer represented by the formula (2), (A _l -BA ₂ ) nX

In Formulas 1 and 2, A ₁ and A ₂ are the same or different and are polymer blocks mainly composed of aromatic vinyl compounds having a weight average molecular weight of 5,000 to 20,000, B is composed of conjugated dienes and aromatic vinyl compounds, and is also aromatic It is a copolymer block composed of tapered blocks of increasing vinyl compounds, the total amount of the bonded aromatic vinyl compound in the components (A) and (B) is 25 to 40% by weight, and the vinyl bond content of the conjugated diene in the B block is 15 to 50 Wt%, the aromatic vinyl compound has 1 to 5 tapered blocks, the weight ratio of the conjugated diene / aromatic vinyl compound in the B block is 97/3 to 85/15, n is an integer of 2 to 4, X represents a coupling agent residue, and the chain amount of the aromatic vinyl compound in which 1 to 4 monomer units are continuous is in 5 to 50 of the total amount of the aromatic vinyl compound. Liability; a (A) / (B), and a ratio of a weight ratio of 40 to 100/60 to 0, the component will have about 100,000 to 300,000 Asphalt modified block copolymer (composition) for the weight-average molecular weight.

In addition, the present invention (A) block copolymer (composition) for asphalt modification, and

(B) It relates to an asphalt composition comprising straight asphalt at a ratio of (A) / (B) (weight ratio) = 2 to 15/98 to 85.

(A) used in the present invention and (b) component is a copolymer block B of an aromatic vinyl compound and a polymer block made mainly of A _1, A _2, and a conjugated diene and an aromatic vinyl compound A _l -BA ₂ or ( A ₁ -BA ₂ ) n is a block copolymer arranged as nX.

Here, the aromatic vinyl compounds used to obtain the components (A) and (B) include styrene, t-butylstyrene, α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylstyrene, N, N-dimethyl-p-aminoethyl styrene, N, N-diethyl-p-aminoethyl styrene, vinylpyridine, etc. are mentioned, Especially styrene and (alpha) -methylstyrene are preferable.

In addition, as the conjugated diene used to obtain the components (A) and (B), 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl- 1,3-pentadiene, 1,3-hexadiene, 4,5-diethyl-l, 3-octadiene, 3-butyl-1,3-octadiene, chloroprene and the like, and the like, 1,3- Butadiene, isoprene, and 1,3-pentadiene are preferable, and 1,3-butadiene is more preferable.

Blocks A ₁ and A ₂ are the same or different and are polymer blocks mainly composed of aromatic vinyl compounds, and may be copolymerized with less than 30% by weight of conjugated diene.

Also, blocks A ₁ and A ₂ may be equal or uneven.

The weight average molecular weights of the blocks A ₁ and A ₂ are 5,000 to 20,000, preferably 8,000 to 17,000. If the weight average molecular weight is less than 5,000, the dissolution time to asphalt is short, so it is easy to process and handle.However, the toughness and adhesive strength are reduced and insufficient. Stability is poor.

In addition, B block is a copolymer block of conjugated diene and an aromatic vinyl compound, and is a taper block in which an aromatic vinyl compound increases.

The total combined aromatic vinyl compound content in the components (A) and (B) is 25 to 40% by weight. When the total amount of the bonded aromatic vinyl compound is less than 25% by weight, the toughness and adhesive force are lowered, the softening point is insufficient, and the flow resistance at high temperature is also insufficient. On the other hand, when it exceeds 40 weight%, the dissolution time to asphalt becomes remarkably long, the penetration degree of asphalt composition is small, and it becomes hard, and low-temperature plasticity falls.

In addition, the vinyl bond content of the conjugated diene in the B block is 15 to 50% by weight, preferably 15 to 40% by weight. If the vinyl bond content is less than 15% by weight, the solubility is consequently insufficient, while if the vinyl bond content is more than 50% by weight, it is not preferable because the low-temperature characteristics when produced with the asphalt composition are degraded.

This vinyl bond content can be easily adjusted with the quantity of the micro structure control agent mentioned later.

The number of taper blocks in the B block is 1 to 5, preferably 1 to 3. When the taper block does not exist in the B block, the solubility to asphalt is deteriorated, and sufficient physical properties are not obtained even when the asphalt composition is manufactured. On the other hand, if the number of tapered blocks exceeds 5, the amount of aromatic vinyl compound added per one is small, so that a component having a long chain length essential for physical property expression cannot be obtained.

In addition, the weight ratio of the conjugated diene / aromatic vinyl compound in B block is 97/3-85/15. If the proportion of conjugated diene in the B block is less than 85% by weight, the molecular weights of both end blocks of A ₁ and A ₂ are reduced, and asphalt properties such as toughness are not sufficiently obtained. If it exceeds 97% by weight, the dissolution time into asphalt is This is significantly longer.

(B) n in General formula (2) which comprises a block copolymer is the number of functional groups of the coupling agent mentioned later, and is an integer of 2-4.

In addition, (b) X in General formula (2) which comprises a block copolymer is a residue of the coupling agent mentioned later.

Further, the chain distribution of the aromatic vinyl compound of the block copolymer is 5 to 50% by weight, preferably 10 to 40% by weight of the chain amount of the aromatic vinyl compound having 1 to 4 consecutive monomer units.

Here, the case where the monomer unit is 0 in the said chain distribution is a case where an aromatic vinyl compound is not contained in B block. On the other hand, more than four components are also essential in order to obtain the physical properties of the asphalt composition, but if contained in more than the above range, the dissolution time into asphalt is significantly longer, which is not preferable.

When the amount of the chain is less than 5% by weight, the dissolution time into the asphalt becomes long, while when the amount of the chain exceeds 50% by weight, the molecular weight of the A ₁ and A ₂ blocks decreases, so that sufficient strength is not obtained when the asphalt composition is made, which is not preferable. .

In addition, the chain amount of the aromatic vinyl compound in which one or two monomer units are continuous is preferably 10 to 35% by weight, more preferably 15 to 30% by weight.

The said chain distribution can be easily adjusted with the quantity of the micro structure control agent mentioned later.

As described above, the B block is a copolymer block of a conjugated diene and an aromatic vinyl compound, and is a tapered block in which the aromatic vinyl compound increases. The B block is a tapered block, and the B block is 5 to 50% by weight of the chain of the aromatic vinyl compound in which 1 to 4 monomer units are contiguous (wherein the amount of chains of 3 to 4 monomer units is continuous. The equivalent 5 to 15% by weight mainly contributes to the following), and the oligomer component (the monomer unit is up to about 10 chains) having less influence on solubility is reduced, so that the adhesion is large and the solubility and physical properties are balanced by high numerical values. Achieve.

In addition, the amount of the chain of the aromatic vinyl compound in which one or two monomer units are continuous is preferably 10 to 35% by weight, thereby improving solubility with straight asphalt.

The tapered block is, for example, by slowly adding the conjugated diene and the aromatic vinyl compound equally and slowly in the hydrocarbon solvent as an initiator, respectively, so that the conjugated diene is preferentially polymerized to start due to the difference in polymerization activity. As a result, the aromatic vinyl compound is polymerized to form a tapered block in which the aromatic vinyl compound gradually increases in the B block. For example, when the B block is polymerized, m taper blocks can be present in the B block by adding a mixture of a conjugated diene and an aromatic vinyl compound in m to the polymerization system.

The use ratio of the (a) and (b) components is (a) / (b) (weight ratio) of 40 to 100/60 to 0, preferably 60 to 100/40 to 0. When the component (A) is less than 40% by weight (the component is greater than 60% by weight), the dissolution time into the asphalt is significantly longer, so that the storage stability at a high temperature is significantly degraded, and the melt viscosity of the composition is significantly increased. Processing and handling become difficult.

The weight average molecular weights of the whole (A) and (B) component are 100,000-300,000. If the weight average molecular weight is less than 100,000, the toughness and adhesive force of the asphalt composition obtained are insufficient, and the fall of fluid resistance will also increase. On the other hand, when it exceeds 300,000, toughness and adhesive force will become large enough, but the dissolution time to asphalt will become remarkably long, storage stability will deteriorate, and the melt viscosity of an asphalt composition will also rise remarkably, and processing and handling will become difficult.

The components (a) and (b) used in the present invention include, for example, an organolithium compound or the like as an polymerization initiator in an inert hydrocarbon solvent, first polymerizing an aromatic vinyl compound, and then simultaneously adding a conjugated diene and an aromatic vinyl compound simultaneously. It can be manufactured by adding and superposing | polymerizing over 5 times, polymerizing an aromatic vinyl compound again, and making a coupling agent react as needed.

As the inert hydrocarbon solvent, hydrocarbon solvents such as pentane, n-hexane, heptane, octane, methylcyclopentane, cyclohexane, benzene and xylene are used, of which cyclohexane is preferable.

As an organoalkali metal compound which is a polymerization initiator, an organolithium compound is preferable. As such an organic lithium compound, an organic monolithium compound, an organic dilithium compound, or an organic polylithium compound is used. Specific examples thereof include ethyllithium, n-propyllithium, isopropyllithium, n-butyllithium, sec-butyllithium, t-butyllithium, hexamethylenedilithium, butadienyllithium, isoprenyldilithium and the like. And n-butyllithium, sec-butyllithium. Such polymerization initiators are used in amounts of 0.02 to 0.2 parts by weight per 100 parts by weight of monomer.

In this case, as a regulator of the microstructure, that is, the vinyl bond content of the conjugated diene moiety, it is a Lewis base such as ether, amine, and the like, specifically diethyl ether, tetrahydrofuran, propyl ether, butyl ether, higher ether, Glycol ether derivatives such as ethylene glycol diethyl ether, ethylene glycol butyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, triethylene glycol butyl ether, ethylene glycol dibutyl ether, and propylene glycol diethyl ether; And amines include tertiary amines such as tetramethylethylenediamine, pyridine and tributylamine. The amount of this micro structure modifier is used in an amount of 0.01 to 0.1 parts by weight per 100 parts by weight of the monomer. In addition, these microstructuring agents are used with inert hydrocarbon solvents.

The polymerization reaction is usually carried out at 20 to 120 ° C, preferably at 30 to 100 ° C. In addition, polymerization can be performed by adjusting to constant temperature or under elevated temperature, without removing heat.

By adding a coupling agent again to the block copolymer living anion obtained in this way, the (b) block copolymer by which the polymer molecular weight chain was extended is obtained.

The component (A) and component (B) can be obtained in a composition in which the component (A) and component (B) are present at the same time by adding a coupling agent of less than equivalents in the preparation of the block copolymer (A). B) Components may be separately prepared and mixed.

In this case, as the coupling agent, alkyl tin halogen compounds such as dibutyl dichloro tin, methyl trichloro tin, butyl trichloro tin, dibutyl dibromo tin, methyl tribromo tin, and butyl tribromo tin, tetra Halogenated tin, such as chloro tin and tetrabromo tin, is used, and a tin type terminal treatment agent includes a triphenyl tin, a trioctyl chloro tin, etc., Preferably dibutyl dichloro tin, tetrachloro tin, trioctyl chloro tin Can be mentioned.

Examples of the ester compound coupling agent include ethyl formate, ethyl acetate, butyl acetate, methyl propionate, phenyl acetate, ethyl benzoate and phenyl benzoate, and preferably ethyl acetate and ethyl benzoate. .

Examples of coupling agents other than tin and ester are dihalogenated alkanes such as dibromomethane, dibromoethane, dibromopropane, methylene chloride, dichloroethane, dichloropropane, dichlorobutane, dichlorosilane, Trichlorosilane, tetrachlorosilane, methyldichlorosilane, dimethyldichlorosilane, monoethyldichlorosilane, diethyldichlorosilane, monobutyldichlorosilane, dibutyldichlorosilane, monohexyldichlorosilane, dihexyldichlorosilane, dibromosilane, Silicon halide compounds such as monomethyldibromosilane and dimethyldibromosilane, divinyl aromatic vinyl compounds such as divinylbenzene and divinyl naphthalene, bisphenol-A, bisphenol-AD, bisphenol-F, other epoxy compounds, propionic acid chloride , Acid chlorides such as adipic dichloride, 1,4-chloromethylbenzene, tolylene diisocyanate, γ -Glycidoxy propyl tri- (alpha)-methoxysilane etc. are mentioned.

(B) The amount of coupling agent used in the preparation of the block copolymer is used in an amount of 0 to about 0.3 molar ratio with respect to the organoalkali metal compound (preferably organolithium compound).

In addition, the binding content of the aromatic vinyl compound in the components (A) and (B) is controlled by the amount of monomer supplied during the polymerization in each step, and the vinyl bond content of the conjugated diene or the chain distribution of the aromatic vinyl compound is determined by the microstructure control agent. It is adjusted by changing the amount of the component of.

In addition, the weight average molecular weight of (a) and (b) component is controlled by the addition amount of a polymerization initiator, for example sec-butyllithium, and / or the addition amount of a coupling agent (for example, dimethyldichlorosilane).

Moreover, in this invention, the double bond of the conjugated diene part of the block copolymer [(A) and (B) component of conjugated diene and an aromatic vinyl compound can be saturated by hydrogenation.

Subsequently, (B) straight asphalt used in the present invention is obtained as a residue after atmospheric distillation and steam or vacuum distillation of asphalt base crude oil. Straight asphalt is easy to dissolve (a) and (b) components which are the block copolymers of this invention, and it is easy to process and handle.

Asphalt used in the present invention is preferably straight asphalt, but instead of straight asphalt, blown asphalt (asphalt obtained by using semi-asphalt-based crude oil as described above) may be used.

Moreover, it is preferable that (B) straight asphalt is 40-200 penetration. If the penetration is less than 40, the dissolution time of the block copolymer to asphalt is long, and the elongation also tends to be small. On the other hand, if it exceeds 200, the toughness and adhesiveness tend to be lowered.

The weight ratio of the above-mentioned (A) block copolymer (composition) and (B) straight asphalt is 2-15 / 98-85, Preferably it is 3-13 / 97-87. If the weight ratio of component (A) is less than 2, the asphalt modification effect is not exhibited, so that the toughness and adhesiveness are insufficient, and the softening point and elongation are low, while if it exceeds 15, the toughness and adhesiveness are sufficient, but the dissolution time into asphalt is significantly longer. In addition, the melt viscosity of the composition increases significantly, making processing and handling difficult.

The block copolymer (composition) of the present invention can be usually used in the form of pellets, crumbs, powders or the like.

In addition, the asphalt composition of the present invention is usually prepared by adding and mixing the above-mentioned (A) block copolymer (composition) into (B) straight asphalt melted at 140-190 degreeC.

In addition, additives such as fillers such as silica, talc and calcium carbonate, pigments, anti-aging agents, crosslinking agents and flame retardants can be blended into the asphalt composition of the present invention. In addition, when using for road pavement, it is also possible to add gravel etc.

In addition, the asphalt composition of the present invention includes other thermoplastic elastomers or thermoplastic resins such as styrene-butadiene rubber latex, ethylene-vinylacetate copolymer, ethylene-ethylacrylate copolymer, atactic polypropylene, 1,2-polybutadiene Or it is possible to use together other polymers, such as ethylene-propylene rubber. In this case, the (A) block copolymer (composition) of the present invention and the other polymer may be kneaded in any ratio in advance, and then pelletized.

Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to these Examples.

In the examples, parts and percentages are by weight unless otherwise indicated.

In addition, various evaluation in an Example is calculated | required as follows.

Characteristics of Block Copolymers

① Weight average molecular weight (Mw)

The column is a weight average molecular weight in terms of standard polystyrene measured using a GPC device (manufactured by Tosoh Corporation, HLC-8020, and using three ZORBAX 1000S and one 300S manufactured by DuPont).

② vinyl bond content

The infrared absorption spectrometer (Perkin Elmer 1600 type) was used for the absorption intensity of 911 cm <^-1> using the Morero method.

③ bound styrene content

It was calculated | required by the infrared spectroscopy apparatus (Perkin Elmer 1600 type) at the absorption intensity of 690 cm <^-1> using the Morero method.

④ Measurement of chain amount of aromatic vinyl compound in the block

The measurement of the chain amount of the aromatic vinyl compound by the oxidative decomposition method using ozone was based on the method developed by Nihon Kogyo University and Professor Tanaka (Japanese Polymer Society Preview, Vol. 29, No. 7, page 2055).

Properties of Asphalt Composition

① dissolution time; A law

A method collects a small amount of the contents during mixing of the asphalt composition during coating, apply it onto the heated slide glass, observe it under an optical microscope (400 times), until no separation occurs on the asphalt and the block copolymer. It was time of.

② dissolution time; B law

In the method B, a small amount of the contents were collected during mixing during the preparation of the asphalt composition, coated on a polyethylene terephthalate (tetron) sheet, observed, and the time taken until the solid particles of the block copolymer disappeared.

③ toughness, adhesion

Measurements were made in accordance with the "Packaging Test Manual" (Japanese Digestion, published in November, 63).

④ penetration, elongation, softening point

It measured according to JIS K2207.

⑤ Storage stability at high temperature

The asphalt composition prepared in the aluminum container was made to flow, and the molecular weight distribution of the block copolymer in the asphalt composition before and after storing the sample after standing still in a oven for 2 weeks in nitrogen atmosphere at 180 degreeC in GPC was measured.

The molecular weight retention rate was calculated from the molecular weight distribution of the block copolymer in the asphalt composition before and after storage.

<Example 1>

Preparation of Block Copolymers

Subsequently, a 100-liter stainless steel polymerization vessel equipped with a jacket and a stirrer was sufficiently replaced with nitrogen gas, and then 50 kg of cyclohexane, 1.9 g of ethylene glycol diethyl ether, and 15 kg of styrene were added. Warmed to 40 ° C.

Subsequently, 9.0 g of sec-butyllithium was added to initiate the polymerization. After completion of the polymerization of styrene, 8.5 kg of 1,3-butadiene and 1 kg of styrene were added in three equal portions and slowly and slowly while passing cold water through the jacket so that the content temperature was 80 ° C. After the completion of the polymerization of the B block, 1.5 kg of additional styrene was added and the polymerization was continued to almost completely polymerize, and then 4 g of dibromoethane was added as a coupling agent and allowed to react for 30 minutes.

After the reaction, 10 ml of methanol was added, the mixture was stirred for 10 minutes, and then the contents were taken out of the polymerization vessel and 50 g of 2,6-di-t-butyl-4-methylphenol (BHT), which is an antioxidant, was added. The polymer containing water obtained by steam scraping this polymerization solution was pulverized in a crumb state by a pulverizer, and then hot-air dried at 80 ° C to obtain a styrene-butadiene block copolymer.

Preparation of Asphalt Composition

570 g of straight asphalt [Kyoto Seki Oil Co., Ltd., 60/80] and 30 g of the styrene-butadiene block copolymer are heated at l80 ° C. while stirring at 70 ° C. [Tokushu Kikyo Co., Ltd., TK Homomixer, 10,000 rpm] to prepare an asphalt composition. The evaluation result of each characteristic is shown to the following Tables 1-2.

<Examples 2 to 5, Comparative Examples 1 to 10>

Example 2, the comparative example 2, and the comparative example 8 are the examples which do not use a coupling agent, and except having changed the addition amount of styrene, 1, 3- butadiene, sec-butyllithium, and ethylene glycol diethyl ether, In the same manner as in Example 1, a block copolymer (composition) was obtained, an asphalt composition was prepared, and the performance thereof was evaluated.

In Example 5, except that the amount of ethylene glycol diethyl ether was changed, a block copolymer (composition) was obtained in the same manner as in Example 1, and an asphalt composition was prepared in the same manner as in Example 1 to evaluate its performance. It was.

Examples and Comparative Examples other than the above were prepared in the same manner as in Example 1 according to the polymerization formulations shown in Tables 1, 3, and 4 below to obtain a block copolymer (composition), and the asphalt composition was prepared in the same manner as in Example 1. The performance was evaluated.

The results are shown in Tables 1 to 6 below.

It can be seen from Table 2 that the asphalt compositions defined in the present invention (Examples 1 to 5) have a short dissolution time into asphalt, which improves storage stability, and also exhibits good toughness, adhesion, elongation and softening point.

On the contrary, as can be seen in Tables 5 and 6, Comparative Example 1 is a case where the conjugated diene / styrene weight ratio and the bound styrene content in the B block are outside the scope of the present invention, and the toughness, adhesive force and softening point are degraded.

In Comparative Example 2, the conjugated diene / styrene weight ratio and the bound styrene content in the Mw and B blocks of the polystyrene block are outside the scope of the present invention, and the dissolution time is long, resulting in poor toughness, elongation and softening point, and poor storage stability.

In Comparative Example 3, the vinyl bond content in the conjugated diene, the conjugated diene / styrene weight ratio in the B block, and the chain ratio of the aromatic vinyl compound having 1 to 4 consecutive monomer units are outside the scope of the present invention. Be degraded.

In Comparative Example 4, the vinyl bond content in the conjugated diene and the conjugated diene / styrene weight ratio in the B block were outside the scope of the present invention, and the dissolution time was long, resulting in poor toughness, adhesion, elongation and softening point, and poor storage stability.

Comparative Example 5 is a case where the vinyl bond content in the conjugated diene is outside the scope of the present invention, the toughness and adhesive strength is degraded, the softening point is also degraded.

Comparative Example 6 is a case where the vinyl bond content in the conjugated diene and the (a) / (b) weight ratio are outside the range of the present invention. The solubility is remarkably poor, and the storage stability is also degraded.

Comparative Example 7 is a case where the bound styrene content is outside the scope of the present invention, the toughness, adhesion and softening point is degraded.

Comparative Example 8 is a case where the bound styrene content is outside the range of the present invention, and the solubility is remarkably decreased, resulting in poor adhesion, elongation and storage stability.

Comparative Example 9 is a case where the conjugated diene is not included in the B block, solubility is remarkably poor, and storage stability is inferior.

Comparative Example 10 is a case where the number of tapered blocks in the B block exceeds the range of the present invention, and the toughness, adhesive force and softening point deteriorate.

Example number One 2 3 4 5 Polymerization prescription (parts / 100 monomers) sec-butyllithium 0.08 0.07 0.1 0.08 n-butyllithium 0.06 Diethyl ether 0.015 Propyl ether 0.025 Ethylene Glycol Ethyl Ether 0.015 0.01 0.01 Monomer addition weight ratio Step 1: styrene 13 12 11.5 14 13 Step 2: styrene 6 8 4 10 6 Step 2: Butadiene 68 68 73 62 68 Step 3: styrene 13 12 11.5 14 13 Coupling agent type Dibromoethane - Dibromoethane Dimethyldichlorosilane Dibromoethane Coupling agent addition amount (part / 100 monomers) 0.03 0 0.03 0.03 0.03

Example One 2 3 4 5 Characteristics of Block Copolymers Polystyrene block Mw (only) (part A ₁ and A ₂ ) 1.05 1.07 1.32 0.92 1.08 M _{1 of} A ₁ -BA ₂ part (only) 14.2 14.5 16.5 12.2 14.4 Conjugated diene vinyl bond content in B (%) 28 28 38 19 28 Conjugated diene / styrene weight ratio in B 91.9 / 8.1 89.5 / 10.5 94.8 / 5.2 86.1 / 13.9 91.9 / 8.1 Number of taper blocks 3 2 3 5 3 The ratio of ST chains 1-4 in B occupies 27 37 21 41 26 The ratio of ST chains 1-2 in B 19 31 13 34 7 A ₁ -BA ₂ / (A ₁ -BA ₂ ) nX weight ratio 72/28 100/0 85/15 65/35 71/29 Combined Styrene Content (%) 32 32 27 38 32 Properties of Asphalt Composition Addition amount of block copolymer; [(A) / (B)] (weight ratio) 3.5 / 96.5 3.5 / 96.5 3.5 / 96.5 3.5 / 96.5 3.5 / 96.5 Dissolution time (minutes) (A method) 25 20 35 20 40 Addition amount of block copolymer; [(A) / (B)] (weight ratio) 5/95 5/95 5/95 5/95 5/95 Dissolution time (minutes) (B method) 18 14 16 16 20 Toughness (mPa · S) 32 35 29 28 31 Adhesion (mPa · S) 24 28 19 21 22 Elongation (15 ℃, cm) 110 110 87 92 82 Elongation (4 ℃, cm) 21 23 20 27 20 Breakthrough (1/10 mm) 41 41 40 42 41 Softening Point (℃) 81 76 82 82 82 Storage stability (%) 83 75 83 81 60

Comparative example number One 2 3 4 5 Polymerization prescription (parts / 100 monomers) sec-butyllithium 0.08 0.04 0.09 0.05 0.1 n-butyllithium Tetrahydrofuran 0.1 Diethyl ether Propyl ether Ethylene Glycol Diethyl Ether 0.015 0.015 0.01 0.04 0.035 Monomer addition weight ratio Step 1: styrene 9 15.5 15 8.5 12 Step 2: styrene 2 12 2 15 8 Step 2: Butadiene 80 57 68 68 68 Step 3: styrene 9 15.5 15 8.5 12 Coupling agent type Dibromoethane - Dibromoethane Dibromoethane Dibromoethane Coupling agent addition amount (part / 100 monomers) 0.04 0 0.04 0.02 0.06

Comparative example number 6 7 8 9 10 Polymerization prescription (parts / 100 monomers) sec-butyllithium 0.07 0.04 0.07 0.08 n-butyllithium 0.07 Tetrahydrofuran Diethyl ether Propyl ether Ethylene Glycol Diethyl Ether 0.01 0.015 0.01 0.04 0.015 Monomer addition weight ratio Step 1: styrene 12 8 18 16 13 Step 2: styrene 8 4 7 0 6 Step 2: Butadiene 68 80 57 68 68 Step 3: styrene 12 8 18 16 13 Coupling agent type Dimethyldichlorosilane Dibromoethane - Dibromoethane Dibromoethane Coupling agent addition amount (part / 100 monomers) 0.04 0.03 0 0.03 0.03

Comparative example One 2 3 4 5 Characteristics of Block Copolymers Polystyrene block Mw (only) (part A ₁ and A ₂ ) 0.68 2.25 1.02 1.18 0.55 M _{1 of} A ₁ -BA ₂ part (only) 8.8 22.1 11.3 22.6 7.5 Conjugated diene vinyl bond content in B (%) 28 28 13 64 58 Conjugated diene / styrene weight ratio in B 97.6 / 2.4 82.6 / 17.4 97.1 / 2.9 81.9 / 18.1 89.5 / 10.5 Number of taper blocks 3 3 3 3 3 The ratio of ST chains 1-4 in B occupies 12 - 54 - - The ratio of ST chains 1-2 in B 8 - 48 - - A ₁ -BA ₂ / (A ₁ -BA ₂ ) nX weight ratio 65/35 100/0 70/30 70/30 52/48 Combined Styrene Content (%) 20 43 32 32 32 Properties of Asphalt Composition Addition amount of block copolymer; [(A) / (B)] (weight ratio) 3.5 / 96.5 3.5 / 96.5 3.5 / 96.5 3.5 / 96.5 3.5 / 96.5 Dissolution time (minutes) (A method) 18 180 50 150 50 Addition amount of block copolymer; [(A) / (B)] (weight ratio) 5/95 5/95 5/95 5/95 5/95 Dissolution time (minutes) (B method) 14 62 38 44 48 Toughness (mPa · S) 19 29 27 21 18 Adhesion (mPa · S) 12 21 14 12 11 Elongation (15 ℃, cm) 72 78 75 70 93 Elongation (4 ℃, cm) 13 20 17 10 14 Breakthrough (1/10 mm) 44 38 42 40 42 Softening Point (℃) 64 75 76 68 62 Storage stability (%) 82 15 35 28 85 -: Not measured.

Comparative example 6 7 8 9 10 Characteristics of Block Copolymers Polystyrene block Mw (only) (part A ₁ and A ₂ ) 1.03 0.7 1.96 1.45 0.99 M _{1 of} A ₁ -BA ₂ part (only) 13.8 15.1 16.8 14.2 12.4 Conjugated diene vinyl bond content in B (%) 13 28 28 28 28 Conjugated diene / styrene weight ratio in B 89.5 / 10.5 95.2 / 4.6 89.1 / 10.9 100/0 91.9 / 8.1 Number of taper blocks 3 3 3 0 10 The ratio of ST chains 1-4 in B occupies - - - - - The ratio of ST chains 1-2 in B - - - - - A ₁ -BA ₂ / (A ₁ -BA ₂ ) nX weight ratio 35/65 965/35 100/0 72/28 72/28 Combined Styrene Content (%) 32 20 43 32 32 Properties of Asphalt Composition Addition amount of block copolymer; [(A) / (B)] (weight ratio) 3.5 / 96.5 3.5 / 96.5 3.5 / 96.5 3.5 / 96.5 3.5 / 96.5 Dissolution time (minutes) (A method) 170 30 160 120 20 Addition amount of block copolymer; [(A) / (B)] (weight ratio) 5/95 5/95 5/95 5/95 5/95 Dissolution time (minutes) (B method) 52 26 58 54 16 Toughness (mPa · S) 27 17 25 26 17 Adhesion (mPa · S) 18 12 15 20 12 Elongation (15 ℃, cm) 82 80 67 78 105 Elongation (4 ℃, cm) 20 24 18 20 31 Breakthrough (1/10 mm) 41 46 38 42 44 Softening Point (℃) 77 64 76 75 64 Storage stability (%) 25 80 27 44 78 -: No measurement

The block copolymer (composition) for modifying the asphalt of the present invention has excellent solubility in various straight asphalts, and has good solubility even on a micro scale as compared to conventional products.

Furthermore, the asphalt composition obtained is excellent in storage stability at high temperature, and especially polymer retention in modified asphalt.

In addition, the block copolymer (composition) for modifying the asphalt of the present invention has low molecular weight of the terminal aromatic vinyl compound polymer block, and there is no deterioration in the physical properties of the asphalt composition obtained. The balance is good.

Therefore, the asphalt composition of the present invention can be suitably used for road pavement, waterproof sheet, and the like.

Claims (2)

(A) a block copolymer represented by Formula 1, A ₁ -BA ₂ , and (B) a block copolymer represented by the formula (2), (A _l -BA ₂ ) nX [Formula 1 and 2, A ₁ and A ₂ are the same or different, a polymer block mainly composed of an aromatic vinyl compound having a weight average molecular weight of 5,000 to 20,000, B is composed of a conjugated diene and an aromatic vinyl compound, and also aromatic It is a copolymer block composed of tapered blocks of increasing vinyl compounds, the total amount of the bonded aromatic vinyl compound in (A) and (B) is 25 to 40% by weight, and the vinyl bond content of the conjugated diene in the B block is 15 to 50% by weight. %, The aromatic vinyl compound has 1 to 5 tapered blocks, the weight ratio of the conjugated diene / aromatic vinyl compound in the B block is 97/3 to 85/15, n is an integer of 2 to 4, X represents a coupling agent residue, and the chain amount of the aromatic vinyl compound in which 1 to 4 monomer units are continuous is 5 to 50% by weight of the total amount of the aromatic vinyl compound.] (A) / (b) component is a block copolymer for modification (composition) containing a weight ratio of 40 to l00 / 60 to 0, the weight average molecular weight of 100,000 to 300,000. (A) Block copolymer for modifying asphalt (composition) according to claim 1, and (B) straight asphalt Asphalt composition characterized in that it comprises (A) / (B) (weight ratio) = 2 to 15/98 to 85 ratio.