JPH01254768A - Thermoplastic elastomer for modifying asphalt - Google Patents

Abstract

PURPOSE:To obtain the title elastomer improving physical properties such as toughness and tenacity by addition to asphalt, comprising blocks of vinyl aromatic compound polymer and a block of butadiene-vinyl aromatic compound copolymer. CONSTITUTION:An elastomer for modifying asphalt which comprises (A) two or more of blocks of vinyl aromatic compound polymer and (B) one or more blocks of butadiene-vinyl aromatic compound copolymer having -85--30 deg.C, preferably -80--40 deg.C glass transition temperature and 10-40wt.%, preferably 12-35wt.% content of vinyl aromatic compound unit and has 30-50wt.%, preferably 35-50wt.% content of the whole vinyl aromatic compound units and 0.1-50g/10minutes, preferably 1-40g/10minutes melt flow value. 100 pts.wt. asphalt is mixed with 1-25 pts.wt. of the elastomer.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a new thermoplastic elastomer for modifying asphalt. More specifically, the present invention can be incorporated into asphalt to improve the balance between its temperature-sensitive properties, toughness, tenacity, elongation, softening point, penetration, and other physical properties and processability. The present invention relates to a thermoplastic elastomer having a specific structure that is suitably used for modifying asphalt for use in applications such as parking, stoppers, silencer sheets, and steel pipe coatings.

BACKGROUND ART Conventionally, asphalt has been widely used in many fields for various purposes because it is easily available and inexpensive.

However, asphalt is inferior in toughness and tenacity, and its biggest drawback is that it has unfavorable temperature-sensitive characteristics, such as becoming soft or hard due to temperature changes.

Therefore, in order to improve such drawbacks, conventionally,
Attempts have been made to modify the material by adding resins such as polyethylene and ethylene-ethyl acrylate copolymer, synthetic rubbers such as styrene-butadiene random copolymer rubber, or natural rubber. However, although the toughness of asphalt is improved in the modification with the above-mentioned resins, the tenacity and low-temperature flexibility are not sufficiently improved, and the modification with the synthetic rubber and natural rubber is
/'', the low temperature flexibility is improved, but it cannot be said that the improvements in toughness, tenacity, flow deformation resistance at high temperatures, etc. are sufficient.

Furthermore, in recent years, attempts have been made to modify asphalt by adding thermoplastic elastomers made of block copolymers of conjugated diene compounds and vinyl aromatic compounds. For this purpose, an asphalt composition blended with a thermoplastic elastomer having a specific structure has been disclosed (Japanese Patent Publication No. 4
7-17319, Japanese Patent Publication No. 59-36949). However, although conventionally used thermoplastic elastomers are quite effective in improving the temperature-sensitive properties of asphalt, they are not necessarily sufficient in improving toughness, tenacity, and elongation. For this purpose, the physical properties of the thermoplastic elastomer are generally improved by increasing the molecular weight of the thermoplastic elastomer or by increasing the amount of the thermoplastic elastomer blended into asphalt. The melting time is unavoidably long, gelation often occurs, and the melt viscosity of the resulting modified asphalt becomes extremely high, impairing workability.

Thus, at present, no asphalt modifier has been found that can satisfactorily balance physical properties such as toughness, tenacity, and elongation of asphalt with workability.

Problems to be Solved by the Invention The present invention overcomes the drawbacks of conventional asphalt modifiers and improves physical properties such as temperature sensitivity, toughness, tenacity, elongation, softening point, and penetration, as well as processability. This was developed with the aim of providing an asphalt modifier for providing asphalt with excellent balance.

Means for Solving the Problems The present inventors have conducted extensive research to develop an asphalt modifier to provide asphalt with the above-mentioned favorable properties. It was discovered that a thermoplastic elastomer consisting of the following materials is suitable for the purpose, and based on this knowledge, the present invention was completed.

That is, the present invention provides (A) at least two vinyl aromatic compound polymer blocks, and (B) a glass transition temperature of 185°C to 130°C and a vinyl aromatic compound unit content of 10 to 40. % by weight of at least one butadiene-vinyl aromatic compound copolymer block,
The present invention also provides a thermoplastic elastomer for asphalt modification, characterized in that the content of all vinyl aromatic compound units is 30 to 50% by weight, and the melt flow value is 0.1 to 50 g/10 minutes. .

The present invention will be explained in detail below.

The thermoplastic elastomer of the present invention is composed of (A) a vinyl aromatic compound polymer block and (B) a butadiene-vinyl aromatic compound copolymer block, and even if the structure is linear, It may also be a branch school letter. (A) It is necessary that at least two blocks exist, but these blocks may be the same or different from each other. Also, (B) there must be at least one block;
In the case of more than one block, the blocks may be the same or different from each other.

Examples of such thermoplastic elastomers include A-B-A S A-B-A', (A-B), X
(In the formula, A and A' are the vinyl aromatic compound polymer blocks of the block (A), B is the butadiene-vinyl aromatic compound copolymer block of the block (B), and X is the residue of the coupling agent. , n is an integer of 2 to 6) Block copolymers represented by these are preferred, but are not limited thereto.

Examples of the monomer constituting the vinyl aromatic compound unit in the thermoplastic elastomer of the present invention include styrene,
Examples include p-methylstyrene, tertiary-butylstyrene, α-methylstyrene, and among these, styrene is preferred. Further, these monomers may be used alone or in combination of two or more.

The vinyl aromatic compound polymer constituting the block (A) may be a homopolymer of vinyl aromatic compounds, or may contain less than 10% by weight, preferably 3% by weight or less of butadiene (1, Although it may be a vinyl aromatic compound-butadiene copolymer containing 3 monolithic) units, it is preferably a vinyl aromatic compound homopolymer. If the vinyl aromatic compound polymer constituting this block contains 10% by weight or more of butadiene units, the effect of improving the flow deformation resistance of asphalt at high temperatures may not be sufficiently exhibited.

Further, the content of vinyl aromatic compound units in the butadiene-vinyl aromatic compound copolymer constituting the block (B) is 10 to 40% by weight, preferably 12 to 35% by weight, more preferably 14 to 33% by weight. Selected within the range of weight %. If this content is less than 10% by weight, the effect of improving the toughness and tenacity of asphalt may not be sufficiently exhibited, and the elongation may decrease, while if it exceeds 40% by weight, the effect of improving the low temperature flexibility of asphalt will be insufficient. A tendency to suffice arises.

In addition, the bonding mode between the butadiene units and the vinyl aromatic compound units in the butadiene-vinyl aromatic compound copolymer constituting the block (B) may be homogeneous or heterogeneous (tapered, etc.). However, it is preferably a uniform type.

Furthermore, the glass transition temperature of the butadiene-vinyl aromatic compound copolymer is 185 as measured by a differential scanning calorimeter.
℃ to -30℃, preferably -80℃ to -40℃
It is necessary to be within the range of .

If the glass transition temperature is lower than 185°C, the elongation of the asphalt may decrease, and if it exceeds -30°C, the effect of improving low-temperature flexibility tends to be insufficient. Regarding the microstructure of the butadiene units in this copolymer, the 1,2-vinyl content is 50% or less, preferably 35% or less, and more preferably 20% or less.

Ru.

The content of total vinyl aromatic compound units in the thermoplastic elastomer of the present invention is 30 to 50% by weight, preferably 3% by weight.
It needs to be in the range of 5 to 50% by weight, more preferably 35 to 45% by weight. If this content is less than 30% by weight, the effect of improving the flow deformation resistance of asphalt at high temperatures may not be sufficiently exhibited;
If it exceeds , the effect of improving the low-temperature flexibility of asphalt tends to be insufficient.

In addition, the melt flow value (AS) of the thermoplastic elastomer
TM D 1238, G) is 0.1-50g/10 minutes,
It is preferably within the range of 1 to 409/10 minutes. If the melt flow value is less than o, ig/io minutes, when kneading with asphalt, the melt kneading time will be significantly longer, and the melt viscosity of the obtained modified asphalt may also be significantly higher. If the temperature exceeds 100%, the asphalt's flow resistance at high temperatures tends to deteriorate significantly.

The thermoplastic elastomer of the present invention can be obtained by first polymerizing a vinyl aromatic compound in an inert hydrocarbon solvent using an organic lithium compound as a polymerization initiator, and then copolymerizing butadiene and the vinyl aromatic compound. A sequential polymerization method in which a vinyl aromatic compound is polymerized again, or a method in which a coupling agent is reacted with a diblock copolymer obtained by first polymerizing a vinyl aromatic compound and then copolymerizing butadiene and a vinyl aromatic compound. It can be manufactured by etc. The polymerization temperature in these reactions is not particularly limited, but it is usually selected in the range of 20 to 130°C in consideration of productivity, but preferably the polymerization initiation temperature is in the range of 30 to 90°C, and the maximum temperature It is desirable that the temperature is in the range of 80 to 120°C.

Examples of the inert hydrocarbon solvent used include cyclohexane, n-hexane, benzene, toluene, octane, and mixtures thereof, and among these, cyclohexane is preferred. These inert hydrocarbon solvents also contain small amounts of polar compounds such as ethers and tertiary amines, such as ethylene glycol dimethyl ether lahydrofuran, in order to adjust the microchannels of the block copolymer. , α-nodoxytetrahydrofuran, N,N
,N',N'-tetramethylethylenediamine, preferably tetrahydrofuran or N,N,N',N
'-Tetramethylethylenediamine may also be present.

Furthermore, a small amount of alkali metal tertiary alkoxylate may be coexisting in the inert hydrocarbon solvent as a randomizer for the block (B) in the block copolymer. Examples of the alkali metal tertiary alkoxylate include potassium-tert-butoxide, sodium-1
Examples include crt-butoxide, cesium-tert-butoquinide, potassium isopentyl oxide, etc.
Among these, potassium tert-butoxide is preferred.

Further, examples of the organic lithium compound include n-butyllithium, sec-butyllithium, tert-butyllithium, etc. Among these, n-butyllithium is preferred.

Furthermore, examples of the coupling agent include polyhalides such as dibromoethane, dichloromethylsilane, silicon tetrachloride, and hexachlorodisilane, polyalkoxides such as tetramethoxysilane, esters such as ethyl acetate and diethyl adipate, propionic acid chloride, Examples include acid chlorides such as adipic acid dichloride, and polyepoxides such as epoxidized soybean oil and epoxidized linseed oil, among which polyhalides and esters are preferred.

A softener, antioxidant, light stabilizer, antiblocking agent, etc. can be added to the thermoplastic elastomer thus obtained, if necessary. Examples of the softening agent include heptene-based, paraffin-based, aromatic process oils, and mixtures thereof, among which naphthenic, paraffin-based, and mixtures thereof are preferred. Examples of the antioxidant include 2,6-tert-butyl-4-methylphenol, n-octadenyl-3-(4'-hydroxy-3
',5'-di-terL-butylphenyl)propionate, 2,2'-methylenebis(4-methyl-6-
terlbutylphenol), 2,2'-methylenebis(4-ethyl-6-LeN-butylphenol),
Hindered phenolic antioxidants such as 2-tert-butyl-6-(3-rert-butyl-2-hydroquine-5-methylbenzyl)-4-methylphenyl acrylate, dilaurylthiodibropiocarbonate, Laurylstearylthiodipropionate, pentaerythritol-tetrakis (β-laurylthiopropionate)
Sulfur-based antioxidants such as tris(nonylphenyl)
Examples include phosphorus-based antioxidants such as phosphite and tris(2,4-di[e"-butylphenyl)phosphite.

In addition, examples of light stabilizers include 2-(2'-hydroquine-5'-methylphenyl)benzotriazole, 2-
Benzotriazole ultraviolet light such as (2'-hydroxy-3',5'-1er4-butylphenyl)benzotriazole, 2-(2'-hydroxy-3',S'-di-tcrt-butylphenyl)-5-chlorobenzotriazole, etc. Examples include absorbers, benzophenone ultraviolet absorbers such as 2-hydroxy-4-methoxybenzophenone, and hindered amine light stabilizers. Further, examples of the antiblocking agent include higher fatty acids, metal salts of higher fatty acids, waxes, fatty acid amides, fatty acid esters, inorganic metal salts, and hydroxides.

The thermoplastic elastomer of the present invention is asphalt 100
Usually 1 to 25 parts by weight, preferably 2 to 25 parts by weight
It is used in a proportion of 15 parts by weight.

If the amount is less than 1 part by weight, the effect of improving the physical properties of the asphalt may not be sufficiently exhibited, and if it exceeds 25 parts by weight, no further effect of improving the physical properties can be expected, and the melt viscosity of the asphalt may increase significantly. As a result, workability tends to decrease significantly.

There is no particular restriction on the elastomer, and conventionally used straight asphalt, prone asphalt, etc. can be used, but the elastomer has a penetration of 40 to 120.
Straight asphalt with a penetration degree of 1o to 3o and blown asphalt with a penetration degree of 1o to 3o are suitable.

The asphalt composition thus prepared may optionally contain various additives conventionally used in asphalt compositions, such as fillers and reinforcements such as silica, talc, calcium carbonate, mineral powder, and glass fiber. Agents, mineral aggregates, pigments, softening agents such as process oils, blowing agents such as azodicarbonamide, thermoplastic resins such as polyethylene and ethylene-ethyl acrylate copolymer, etc. can be added.

Furthermore, when used for road paving, the asphalt composition is usually mixed with aggregates such as mineral stones, sand, and slag.

The asphalt composition is prepared by melt-kneading the required amount of asphalt, the thermoplastic elastomer of the present invention, and various additives used as desired using, for example, a hot melt kettle, roll, kneader, Banbury mixer 1 extrusion i, etc. It can be prepared by:

Effects of the Invention The thermoplastic elastomer for asphalt modification of the present invention is composed of a block copolymer having a specific structure, and by blending it into asphalt, it can improve temperature-sensitive properties, toughness, tenacity, elongation, and softening point. , it is possible to provide modified asphalt with an excellent balance between physical properties such as penetration and workability.

Since the modified asphalt containing the thermoplastic elastomer of the present invention has the above-mentioned properties, it is suitable for use in, for example, waterproof sheets, stoppers, silencer sheets, steel pipe coatings, road paving, etc. used.

Examples Next, the present invention will be explained in more detail with reference to examples.
The present invention is not limited in any way by these examples.

The properties of the thermoplastic elastomer and asphalt composition were determined according to the following method.

Physical properties of thermoplastic elastomer (1) Total styrene unit content 26 using an ultraviolet spectrophotometer (Hitachi UV-200)
It was measured from the absorption intensity at 2 nm.

(2) (A) Styrene polymer block amount “Oxidative decomposition method using osmium tetroxide and terL-butyl hydroperoxide [described in [Journal of Polymer Science] Volume 1, Page 429 (1946)]
I asked for it according to. The weight of the styrene polymer block was measured from the absorption intensity at 262 nm using an ultraviolet spectrophotometer (Hitachi UV-200).

(3) (B) Styrene unit content in copolymer block Calculated from the difference between the total styrene unit content and the styrene polymer block amount.

(4) (B) Glass transition temperature of copolymer block Differential scanning calorimeter (manufactured by Seiko Electronics Co., Ltd., 5SC1575
) according to 357M D34111-82,
The temperature change in specific heat was measured, and the extrapolated temperature T was determined to be the glass transition temperature. Note that the temperature increase rate was 10° C./min.

(5) Melt flow value Measured according to G conditions according to ASTM D-1238.

(6) Tensile properties and hardness The tensile properties were measured using J
Determined in accordance with IS K-6301, hardness determined by ASTIJ
It was determined in accordance with D-2240.

Characteristics of Asphalt Composition (7) Toughness: Measured according to Test Methods for Tenacity Paving Works (edited by Japan Road Construction Industry Association).

(8) Elongation, penetration, softening point Measured in accordance with JIS K-2207.

(9) Temperature-sensitive properties The temperature-sensitive properties on the high temperature side (flow resistance at high temperatures) were evaluated based on the softening point in three ranks: ○, Δ, and X (○ indicates the best flow resistance).

The temperature-sensitive characteristics on the low-temperature side (flexibility at low temperatures) are
A composition sheet with a width of 20 mm and a length of 100 mm was placed in a dry ice/methanol refrigerant maintained at -10°C.
After being immersed for 5 minutes, they were quickly bent by hand and evaluated on a 3-rank scale, with 0 being no cracks, 1 being completely cracked, and 1 being △ being in between.

(10) Melt viscosity Measured using a Type B viscometer at 180'C.

Examples 1 to 4, Comparative Examples 1 to 4 After a 1Oa stainless steel reactor equipped with a jacket and a stirrer was sufficiently purged with nitrogen, cyclohexane, tetrahydrofuran, and styrene (referred to as primary styrene) were charged in the amounts shown in Table 1. Then, hot water was passed through the jacket to set the contents at 90° C., and then a predetermined amount of a cyclohexane solution of n-butyllithium was added to start polymerization of styrene.

10 minutes after styrene has almost completely polymerized, styrene (referred to as intermediate styrene) and butadiene are added at the same time in a predetermined amount to continue polymerization, and after 2 minutes, a metering pump is used for 10 to 60 minutes until the remaining amount remains. of butadiene (referred to as continuous butadiene) was continuously supplied into the polymerization system to continue the polymerization.

After these have almost completely polymerized and reached the maximum temperature, 1
After 5 minutes, a predetermined amount of styrene (referred to as secondary styrene) was added again to continue polymerization. After adding the second styrene, the temperature was maintained at the same temperature for 15 minutes to complete polymerization, and then 10 g of methanol was added to stop the polymerization. Immediately after charging the first styrene, the inside of the system was continuously stirred using a stirrer.

After the reaction is completed, the polymer solution is extracted and added with 2.6-
The solvent was removed by adding 8 g of tert-butyl-4-methylphenol, 4 g of tris(nonylphenyl) phosphite, and 4 g of dilaurylthiodipropionate, followed by dehydration with a hot roll. A thermoplastic elastomer was obtained.

Thermoplastic obtained in this way? - Table 2 shows the physical properties of the elastomer.

Next, 500 g of straight asphalt (Storas 60/8G, manufactured by Nippon Oil Co., Ltd.) and 25 g of the above thermoplastic elastomer were melt-kneaded by heating at 180° C. for 1 hour to prepare an asphalt composition. Its characteristics are shown in Table 3.

Example 5 After a 10a stainless steel reactor equipped with a jacket and a stirrer was sufficiently purged with nitrogen, cyclohexane, tetrahydrofuran, and styrene (referred to as primary styrene) were charged in the amounts shown in Table 1, and hot water was poured through the jacket to drain the contents. After setting the temperature to 77°C, a predetermined amount of a cyclohexane solution of n-butyllithium was added to start polymerization of styrene. Eight minutes after styrene was completely polymerized, styrene (referred to as intermediate styrene) and butadiene were simultaneously added in predetermined amounts to continue polymerization. After 15 minutes, the temperature reached 98° C. when polymerization was almost completely completed.

Next, a predetermined amount of styrene (referred to as secondary styrene) was added again to continue the polymerization, and the polymerization was completed by holding at the same temperature for 15 minutes, after which 10 g of methanol was added to stop the polymerization and the I-0 Immediately after charging the first styrene, the system was stirred using a stirrer while methanol was added to stop polymerization.

Thereafter, a thermoplastic elastomer was obtained by processing in the same manner as in Examples 1 to 4, and an asphalt composition was further prepared. Table 2 shows the physical properties of the thermoplastic elastomer, and Table 3 shows the properties of the Askuald composition.

Example 6.7 After a Loll stainless steel reactor equipped with a jacket and a stirrer was sufficiently purged with nitrogen, cyclohexane, tetrahydro-7rane, and styrene (referred to as primary styrene) were charged in the amounts shown in Table 1, and the reactor was placed in the jacket. After the contents were set at about 70 to 80° C. by passing hot water, a predetermined amount of a cyclohexane solution of n-butyllithium was added to start polymerization of styrene. One minute after styrene has almost completely polymerized, styrene (referred to as intermediate styrene) and butadiene are simultaneously added in predetermined amounts to continue polymerization, and after 2 minutes, a metering pump is used to remove the remaining butadiene (
(referred to as continuous addition butadiene) is continuously supplied into the polymerization system,
Polymerization was allowed to continue. 15 minutes after this was almost completely polymerized and the maximum temperature was reached, a coupling agent in the amount shown in Table 1 was added, reacted, and maintained at the same temperature for 10 minutes.

Immediately after charging the first styrene, the inside of the system was continuously stirred using a stirrer.

Next, a thermoplastic elastomer was obtained by processing in the same manner as in Examples 1 to 4, and an asphalt composition was further prepared. Table 2 shows the physical properties of the thermoplastic elastomer, and Table 3 shows the properties of the asphalt composition.

Comparative Example 5 After a 10a stainless steel reactor equipped with a jacket and a stirrer was sufficiently purged with nitrogen, cyclohexane, tetrahydro7rane, and styrene (referred to as primary styrene) were charged in the amounts shown in Table 1, and hot water was passed through the jacket to change the contents. After setting the temperature at 68° C., a predetermined amount of a cyclohexane solution of n-butyllithium was added to initiate styrene polymerization.

10 minutes after styrene has almost completely polymerized, a predetermined amount of butadiene is added to continue the polymerization, and 15 minutes after butadiene has almost completely polymerized and the maximum temperature has been reached,
A predetermined amount of silicon tetrachloride is added and reacted, and the reaction temperature is 10 degrees.
Hold for minutes. Immediately after charging the first styrene, the inside of the system was continuously stirred using a stirrer.

Next, a thermoplastic elastomer was obtained by processing in the same manner as in Examples 1 to 4, and an asphalt composition was further prepared.

Table 1 shows the physical properties of the thermoplastic elastomer, and Table 3 shows the properties of the asphalt composition.

Comparative Example 6 After a Loll stainless steel reactor equipped with a jacket and a stirrer was sufficiently purged with nitrogen, cyclohexane, tetrahydrofuran, and styrene (referred to as primary styrene) were charged in the amounts shown in Table 1, and hot water was passed through the jacket. After setting the contents at 76° C., a predetermined amount of a cyclohexane solution of n-butyllithium was added to start polymerization of styrene.

10 minutes after styrene has almost completely polymerized, a predetermined amount of butadiene is added to continue the polymerization, and 15 minutes after butadiene has almost completely polymerized and reached the maximum temperature, styrene (secondary styrene) is added again. ) was added in a predetermined amount to continue polymerization, and after completing the polymerization by holding at the same temperature for 15 minutes, methanol 109 was added to stop the polymerization. Immediately after charging the first styrene, the inside of the system was continuously stirred using a stirrer.

Next, a thermoplastic elastomer was obtained by processing in the same manner as in Examples 1 to 4, and an asphalt composition was further prepared.

Table 2 shows the physical properties of the thermoplastic elastomer, and Table 3 shows the properties of the asphalt composition.

Example 8 Blown asphalt (manufactured by Nippon Oil Co., Ltd., A-Blowas 20/30) 500 y and the thermoplastic elastomer 509 obtained in Example 3 were melt-kneaded at 18,000 for 90 minutes to prepare an asphalt composition. The third characteristic is
Shown in the table.

Comparative Example 7 The same blown asphalt 5009 as in Example 8 and 50 g of the thermoplastic elastomer obtained in Comparative Example 5 were melt-kneaded at 180° C. for 90 minutes to prepare an asphalt composition. Its characteristics are shown in Table 3.

From Table 3, the asphalt compositions of Examples 1-7 were compared with the asphalt compositions of Comparative Examples 1-6, and the asphalt composition of Example 8 was compared with the asphalt composition of Comparative Example 7. It can be seen that the balance between asphalt's physical properties such as temperature-sensitive properties, toughness, tenacity, elongation, and penetration, and workability are significantly improved.

/ / / // /″ / Procedural amendment June 21, 1988 Director General of the Patent Office Yoshi 1) Moon Takeshi 1, Indication of the case 1988 Patent Application No. 82857 2, Name of the invention Heat for asphalt reforming Plastic Elastomer 3, Relationship with the amended person case Patent applicant: 1-1-2 Yurakucho, Chiyoda-ku, Tokyo Japan Elastomer Co., Ltd. Representative: Takao Yokoyama 4, Agent: 2-2-2 Shinbashi, Minato-ku, Tokyo Gogawa Shimitsu Kuninobu Building 8th floor 5
, Date of amendment order Vol. 6, Number of inventions increased by amendment O 8, Contents of amendment (1) "For coating" in the third line of page 2 of the specification is corrected to "for coating, road paving." .

(2) "Preferably...necessary" on the 3rd to 4th lines of page 9 was changed to "preferably more than 35% by weight and less than 50% by weight, more preferably more than 35% by weight and less than 45% by weight."
% by weight or less. ” will be corrected.

(3) In the 7th line from the bottom of page 1 I, replace “butoxide” with “
amyl oxide”.

(4) “Asphalt” in 5 lines from the bottom of page 14
will be corrected to "of the said asphalt."

(5) In the bottom two lines of page 14, "the above-mentioned elastomer" has been corrected to "the above-mentioned asphalt."

(6) “90°C” in the 8th line from the bottom of page 19 is changed to “about 9°C”.
Corrected to 0℃.

(7) "Table 1" on page 24, line 7 of the same page has been changed to "Table 2."
I will correct it.

Claims (1)

[Claims] 1 (A) at least two vinyl aromatic compound polymer blocks; and (B) a glass transition temperature of -85°C to -3
At 0°C, the content of vinyl aromatic compound units is 10-40
% by weight of butadiene-at least one vinyl aromatic compound copolymer block, and the content of total vinyl aromatic compound units is 30 to 50 weight %, and the melt flow value is 0.1 to 50 g/10 A thermoplastic elastomer for asphalt modification characterized by a